urltomarkdown/node_modules/ws/lib/validation.js

105 lines
2.4 KiB
JavaScript
Executable File

'use strict';
/**
* Checks if a status code is allowed in a close frame.
*
* @param {Number} code The status code
* @return {Boolean} `true` if the status code is valid, else `false`
* @public
*/
function isValidStatusCode(code) {
return (
(code >= 1000 &&
code <= 1014 &&
code !== 1004 &&
code !== 1005 &&
code !== 1006) ||
(code >= 3000 && code <= 4999)
);
}
/**
* Checks if a given buffer contains only correct UTF-8.
* Ported from https://www.cl.cam.ac.uk/%7Emgk25/ucs/utf8_check.c by
* Markus Kuhn.
*
* @param {Buffer} buf The buffer to check
* @return {Boolean} `true` if `buf` contains only correct UTF-8, else `false`
* @public
*/
function _isValidUTF8(buf) {
const len = buf.length;
let i = 0;
while (i < len) {
if ((buf[i] & 0x80) === 0) {
// 0xxxxxxx
i++;
} else if ((buf[i] & 0xe0) === 0xc0) {
// 110xxxxx 10xxxxxx
if (
i + 1 === len ||
(buf[i + 1] & 0xc0) !== 0x80 ||
(buf[i] & 0xfe) === 0xc0 // Overlong
) {
return false;
}
i += 2;
} else if ((buf[i] & 0xf0) === 0xe0) {
// 1110xxxx 10xxxxxx 10xxxxxx
if (
i + 2 >= len ||
(buf[i + 1] & 0xc0) !== 0x80 ||
(buf[i + 2] & 0xc0) !== 0x80 ||
(buf[i] === 0xe0 && (buf[i + 1] & 0xe0) === 0x80) || // Overlong
(buf[i] === 0xed && (buf[i + 1] & 0xe0) === 0xa0) // Surrogate (U+D800 - U+DFFF)
) {
return false;
}
i += 3;
} else if ((buf[i] & 0xf8) === 0xf0) {
// 11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
if (
i + 3 >= len ||
(buf[i + 1] & 0xc0) !== 0x80 ||
(buf[i + 2] & 0xc0) !== 0x80 ||
(buf[i + 3] & 0xc0) !== 0x80 ||
(buf[i] === 0xf0 && (buf[i + 1] & 0xf0) === 0x80) || // Overlong
(buf[i] === 0xf4 && buf[i + 1] > 0x8f) ||
buf[i] > 0xf4 // > U+10FFFF
) {
return false;
}
i += 4;
} else {
return false;
}
}
return true;
}
try {
let isValidUTF8 = require('utf-8-validate');
/* istanbul ignore if */
if (typeof isValidUTF8 === 'object') {
isValidUTF8 = isValidUTF8.Validation.isValidUTF8; // utf-8-validate@<3.0.0
}
module.exports = {
isValidStatusCode,
isValidUTF8(buf) {
return buf.length < 150 ? _isValidUTF8(buf) : isValidUTF8(buf);
}
};
} catch (e) /* istanbul ignore next */ {
module.exports = {
isValidStatusCode,
isValidUTF8: _isValidUTF8
};
}