File size: 4,259 Bytes
8ead80b |
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 |
/*
* Copyright (c) 2009 Baptiste Coudurier <[email protected]>
*
* This file is part of FFmpeg.
*
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "config.h"
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#if HAVE_IO_H
#include <io.h>
#endif
#if HAVE_BCRYPT
#include <windows.h>
#include <bcrypt.h>
#endif
#if CONFIG_GCRYPT
#include <gcrypt.h>
#elif CONFIG_OPENSSL
#include <openssl/rand.h>
#endif
#include <fcntl.h>
#include <math.h>
#include <time.h>
#include <string.h>
#include "avassert.h"
#include "file_open.h"
#include "internal.h"
#include "intreadwrite.h"
#include "timer.h"
#include "random_seed.h"
#include "sha.h"
#ifndef TEST
#define TEST 0
#endif
static int read_random(uint8_t *dst, size_t len, const char *file)
{
#if HAVE_UNISTD_H
FILE *fp = avpriv_fopen_utf8(file, "r");
size_t err;
if (!fp)
return AVERROR_UNKNOWN;
setvbuf(fp, NULL, _IONBF, 0);
err = fread(dst, 1, len, fp);
fclose(fp);
if (err != len)
return AVERROR_UNKNOWN;
return 0;
#else
return AVERROR(ENOSYS);
#endif
}
static uint32_t get_generic_seed(void)
{
uint64_t tmp[120/8];
struct AVSHA *sha = (void*)tmp;
clock_t last_t = 0;
clock_t last_td = 0;
clock_t init_t = 0;
static uint64_t i = 0;
static uint32_t buffer[512] = { 0 };
unsigned char digest[20];
uint64_t last_i = i;
av_assert0(sizeof(tmp) >= av_sha_size);
if(TEST){
memset(buffer, 0, sizeof(buffer));
last_i = i = 0;
}else{
#ifdef AV_READ_TIME
buffer[13] ^= AV_READ_TIME();
buffer[41] ^= AV_READ_TIME()>>32;
#endif
}
for (;;) {
clock_t t = clock();
if (last_t + 2*last_td + (CLOCKS_PER_SEC > 1000) >= t) {
last_td = t - last_t;
buffer[i & 511] = 1664525*buffer[i & 511] + 1013904223 + (last_td % 3294638521U);
} else {
last_td = t - last_t;
buffer[++i & 511] += last_td % 3294638521U;
if ((t - init_t) >= CLOCKS_PER_SEC>>5)
if (last_i && i - last_i > 4 || i - last_i > 64 || TEST && i - last_i > 8)
break;
}
last_t = t;
if (!init_t)
init_t = t;
}
if(TEST) {
buffer[0] = buffer[1] = 0;
} else {
#ifdef AV_READ_TIME
buffer[111] += AV_READ_TIME();
#endif
}
av_sha_init(sha, 160);
av_sha_update(sha, (const uint8_t *)buffer, sizeof(buffer));
av_sha_final(sha, digest);
return AV_RB32(digest) + AV_RB32(digest + 16);
}
int av_random_bytes(uint8_t* buf, size_t len)
{
int err;
#if HAVE_BCRYPT
BCRYPT_ALG_HANDLE algo_handle;
NTSTATUS ret = BCryptOpenAlgorithmProvider(&algo_handle, BCRYPT_RNG_ALGORITHM,
MS_PRIMITIVE_PROVIDER, 0);
if (BCRYPT_SUCCESS(ret)) {
NTSTATUS ret = BCryptGenRandom(algo_handle, (PUCHAR)buf, len, 0);
BCryptCloseAlgorithmProvider(algo_handle, 0);
if (BCRYPT_SUCCESS(ret))
return 0;
}
#endif
#if HAVE_ARC4RANDOM_BUF
arc4random_buf(buf, len);
return 0;
#endif
err = read_random(buf, len, "/dev/urandom");
if (!err)
return err;
#if CONFIG_GCRYPT
gcry_randomize(buf, len, GCRY_VERY_STRONG_RANDOM);
return 0;
#elif CONFIG_OPENSSL
if (RAND_bytes(buf, len) == 1)
return 0;
err = AVERROR_EXTERNAL;
#endif
return err;
}
uint32_t av_get_random_seed(void)
{
uint32_t seed;
if (av_random_bytes((uint8_t *)&seed, sizeof(seed)) < 0)
return get_generic_seed();
return seed;
}
|