@syncfusion/ej2-pdf
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Feature-rich JavaScript PDF library with built-in support for loading and manipulating PDF document.
115 lines (114 loc) • 4.46 kB
JavaScript
/**
* MD5 hash implementation used internally by PDF cryptography helpers.
*
* @private
*/
var _MD5 = /** @class */ (function () {
function _MD5() {
/**
* Rotation amounts per round.
*
* @private
*/
this._r = new Uint8Array([7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 7, 12, 17, 22, 5, 9, 14, 20, 5, 9,
14, 20, 5, 9, 14, 20, 5, 9, 14, 20, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 4, 11, 16, 23, 6, 10, 15, 21,
6, 10, 15, 21, 6, 10, 15, 21, 6, 10, 15, 21]);
/**
* K constants for MD5.
*
* @private
*/
this._k = new Int32Array([-680876936, -389564586, 606105819, -1044525330, -176418897, 1200080426, -1473231341, -45705983,
1770035416, -1958414417, -42063, -1990404162, 1804603682, -40341101, -1502002290, 1236535329, -165796510, -1069501632,
643717713, -373897302, -701558691, 38016083, -660478335, -405537848, 568446438, -1019803690, -187363961, 1163531501,
-1444681467, -51403784, 1735328473, -1926607734, -378558, -2022574463, 1839030562, -35309556, -1530992060, 1272893353,
-155497632, -1094730640, 681279174, -358537222, -722521979, 76029189, -640364487, -421815835, 530742520, -995338651,
-198630844, 1126891415, -1416354905, -57434055, 1700485571, -1894986606, -1051523, -2054922799, 1873313359, -30611744,
-1560198380, 1309151649, -145523070, -1120210379, 718787259, -343485551]);
}
/**
* Compute the MD5 hash for the provided data slice.
*
* @private
* @param {Uint8Array} data bytes.
* @param {number} offset offset in `data`.
* @param {number} length of bytes to hash.
* @returns {Uint8Array} The 16-byte MD5 digest as `Uint8Array`.
*/
_MD5.prototype.hash = function (data, offset, length) {
var h0 = 1732584193;
var h1 = -271733879;
var h2 = -1732584194;
var h3 = 271733878;
var paddedLength = (length + 72) & ~63;
var padded = new Uint8Array(paddedLength);
var i = 0;
var j = 0;
for (; i < length; ++i) {
padded[i] = data[offset++];
}
padded[i++] = 0x80;
var n = paddedLength - 8;
while (i < n) {
padded[i++] = 0;
}
padded[i++] = (length << 3) & 0xff;
padded[i++] = (length >> 5) & 0xff;
padded[i++] = (length >> 13) & 0xff;
padded[i++] = (length >> 21) & 0xff;
padded[i++] = (length >>> 29) & 0xff;
padded[i++] = 0;
padded[i++] = 0;
padded[i++] = 0;
var w = new Int32Array(16);
for (i = 0; i < paddedLength;) {
for (j = 0; j < 16; ++j, i += 4) {
w[j] = padded[i] |
(padded[i + 1] << 8) |
(padded[i + 2] << 16) |
(padded[i + 3] << 24);
}
var a = h0;
var b = h1;
var c = h2;
var d = h3;
var e = void 0;
var f = void 0;
for (j = 0; j < 64; ++j) {
if (j < 16) {
e = (b & c) | (~b & d);
f = j;
}
else if (j < 32) {
e = (d & b) | (~d & c);
f = (5 * j + 1) & 15;
}
else if (j < 48) {
e = b ^ c ^ d;
f = (3 * j + 5) & 15;
}
else {
e = c ^ (b | ~d);
f = (7 * j) & 15;
}
var previous = d;
var current = (a + e + this._k[j] + w[f]) | 0;
var rotate = this._r[j];
d = c;
c = b;
b = (b + ((current << rotate) | (current >>> (32 - rotate)))) | 0;
a = previous;
}
h0 = (h0 + a) | 0;
h1 = (h1 + b) | 0;
h2 = (h2 + c) | 0;
h3 = (h3 + d) | 0;
}
return new Uint8Array([h0 & 0xFF, (h0 >> 8) & 0xFF, (h0 >> 16) & 0xFF, (h0 >>> 24) & 0xFF, h1 & 0xFF,
(h1 >> 8) & 0xFF, (h1 >> 16) & 0xFF, (h1 >>> 24) & 0xFF, h2 & 0xFF, (h2 >> 8) & 0xFF, (h2 >> 16) & 0xFF,
(h2 >>> 24) & 0xFF, h3 & 0xFF, (h3 >> 8) & 0xFF, (h3 >> 16) & 0xFF, (h3 >>> 24) & 0xFF
]);
};
return _MD5;
}());
export { _MD5 };