devsite/node_modules/ws/lib/validation.js

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JavaScript
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2024-07-08 01:49:38 +00:00
'use strict';
const { isUtf8 } = require('buffer');
const { hasBlob } = require('./constants');
//
// Allowed token characters:
//
// '!', '#', '$', '%', '&', ''', '*', '+', '-',
// '.', 0-9, A-Z, '^', '_', '`', a-z, '|', '~'
//
// tokenChars[32] === 0 // ' '
// tokenChars[33] === 1 // '!'
// tokenChars[34] === 0 // '"'
// ...
//
// prettier-ignore
const tokenChars = [
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 0 - 15
0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, // 16 - 31
0, 1, 0, 1, 1, 1, 1, 1, 0, 0, 1, 1, 0, 1, 1, 0, // 32 - 47
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 0, 0, 0, // 48 - 63
0, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 64 - 79
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 0, 0, 1, 1, // 80 - 95
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, // 96 - 111
1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 0, 1, 0, 1, 0 // 112 - 127
];
/**
* 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;
}
/**
* Determines whether a value is a `Blob`.
*
* @param {*} value The value to be tested
* @return {Boolean} `true` if `value` is a `Blob`, else `false`
* @private
*/
function isBlob(value) {
return (
hasBlob &&
typeof value === 'object' &&
typeof value.arrayBuffer === 'function' &&
typeof value.type === 'string' &&
typeof value.stream === 'function' &&
(value[Symbol.toStringTag] === 'Blob' ||
value[Symbol.toStringTag] === 'File')
);
}
module.exports = {
isBlob,
isValidStatusCode,
isValidUTF8: _isValidUTF8,
tokenChars
};
if (isUtf8) {
module.exports.isValidUTF8 = function (buf) {
return buf.length < 24 ? _isValidUTF8(buf) : isUtf8(buf);
};
} /* istanbul ignore else */ else if (!process.env.WS_NO_UTF_8_VALIDATE) {
try {
const isValidUTF8 = require('utf-8-validate');
module.exports.isValidUTF8 = function (buf) {
return buf.length < 32 ? _isValidUTF8(buf) : isValidUTF8(buf);
};
} catch (e) {
// Continue regardless of the error.
}
}