File size: 2,307 Bytes
5fae594 |
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 |
/**
* Implements fast shallow verification of hostnames. This does not perform a
* struct check on the content of labels (classes of Unicode characters, etc.)
* but instead check that the structure is valid (number of labels, length of
* labels, etc.).
*
* If you need stricter validation, consider using an external library.
*/
function isValidAscii(code: number): boolean {
return (
(code >= 97 && code <= 122) || (code >= 48 && code <= 57) || code > 127
);
}
/**
* Check if a hostname string is valid. It's usually a preliminary check before
* trying to use getDomain or anything else.
*
* Beware: it does not check if the TLD exists.
*/
export default function (hostname: string): boolean {
if (hostname.length > 255) {
return false;
}
if (hostname.length === 0) {
return false;
}
if (
/*@__INLINE__*/ !isValidAscii(hostname.charCodeAt(0)) &&
hostname.charCodeAt(0) !== 46 && // '.' (dot)
hostname.charCodeAt(0) !== 95 // '_' (underscore)
) {
return false;
}
// Validate hostname according to RFC
let lastDotIndex = -1;
let lastCharCode = -1;
const len = hostname.length;
for (let i = 0; i < len; i += 1) {
const code = hostname.charCodeAt(i);
if (code === 46 /* '.' */) {
if (
// Check that previous label is < 63 bytes long (64 = 63 + '.')
i - lastDotIndex > 64 ||
// Check that previous character was not already a '.'
lastCharCode === 46 ||
// Check that the previous label does not end with a '-' (dash)
lastCharCode === 45 ||
// Check that the previous label does not end with a '_' (underscore)
lastCharCode === 95
) {
return false;
}
lastDotIndex = i;
} else if (
!(/*@__INLINE__*/ (isValidAscii(code) || code === 45 || code === 95))
) {
// Check if there is a forbidden character in the label
return false;
}
lastCharCode = code;
}
return (
// Check that last label is shorter than 63 chars
len - lastDotIndex - 1 <= 63 &&
// Check that the last character is an allowed trailing label character.
// Since we already checked that the char is a valid hostname character,
// we only need to check that it's different from '-'.
lastCharCode !== 45
);
}
|