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- /* from http://www.movable-type.co.uk/scripts/sha1.html */
- /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
- /* SHA-1 implementation in JavaScript (c) Chris Veness 2002-2014 / MIT Licence */
- /* */
- /* - see http://csrc.nist.gov/groups/ST/toolkit/secure_hashing.html */
- /* http://csrc.nist.gov/groups/ST/toolkit/examples.html */
- /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
- (function (_window) {
- /* jshint node:true *//* global define, escape, unescape */
- 'use strict';
- /**
- * SHA-1 hash function reference implementation.
- *
- * @namespace
- */
- var Sha1 = {};
- _window.Sha1 = Sha1;
- /**
- * Generates SHA-1 hash of string.
- *
- * @param {string} msg - (Unicode) string to be hashed.
- * @returns {string} Hash of msg as hex character string.
- */
- Sha1.hash = function(msg) {
- // convert string to UTF-8, as SHA only deals with byte-streams
- msg = msg.utf8Encode();
- // constants [§4.2.1]
- var K = [ 0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6 ];
- // PREPROCESSING
- msg += String.fromCharCode(0x80); // add trailing '1' bit (+ 0's padding) to string [§5.1.1]
- // convert string msg into 512-bit/16-integer blocks arrays of ints [§5.2.1]
- var l = msg.length/4 + 2; // length (in 32-bit integers) of msg + ‘1’ + appended length
- var N = Math.ceil(l/16); // number of 16-integer-blocks required to hold 'l' ints
- var M = new Array(N);
- for (var i=0; i<N; i++) {
- M[i] = new Array(16);
- for (var j=0; j<16; j++) { // encode 4 chars per integer, big-endian encoding
- M[i][j] = (msg.charCodeAt(i*64+j*4)<<24) | (msg.charCodeAt(i*64+j*4+1)<<16) |
- (msg.charCodeAt(i*64+j*4+2)<<8) | (msg.charCodeAt(i*64+j*4+3));
- } // note running off the end of msg is ok 'cos bitwise ops on NaN return 0
- }
- // add length (in bits) into final pair of 32-bit integers (big-endian) [§5.1.1]
- // note: most significant word would be (len-1)*8 >>> 32, but since JS converts
- // bitwise-op args to 32 bits, we need to simulate this by arithmetic operators
- M[N-1][14] = ((msg.length-1)*8) / Math.pow(2, 32); M[N-1][14] = Math.floor(M[N-1][14]);
- M[N-1][15] = ((msg.length-1)*8) & 0xffffffff;
- // set initial hash value [§5.3.1]
- var H0 = 0x67452301;
- var H1 = 0xefcdab89;
- var H2 = 0x98badcfe;
- var H3 = 0x10325476;
- var H4 = 0xc3d2e1f0;
- // HASH COMPUTATION [§6.1.2]
- var W = new Array(80); var a, b, c, d, e;
- for (var i=0; i<N; i++) {
- // 1 - prepare message schedule 'W'
- for (var t=0; t<16; t++) W[t] = M[i][t];
- for (var t=16; t<80; t++) W[t] = Sha1.ROTL(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16], 1);
- // 2 - initialise five working variables a, b, c, d, e with previous hash value
- a = H0; b = H1; c = H2; d = H3; e = H4;
- // 3 - main loop
- for (var t=0; t<80; t++) {
- var s = Math.floor(t/20); // seq for blocks of 'f' functions and 'K' constants
- var T = (Sha1.ROTL(a,5) + Sha1.f(s,b,c,d) + e + K[s] + W[t]) & 0xffffffff;
- e = d;
- d = c;
- c = Sha1.ROTL(b, 30);
- b = a;
- a = T;
- }
- // 4 - compute the new intermediate hash value (note 'addition modulo 2^32')
- H0 = (H0+a) & 0xffffffff;
- H1 = (H1+b) & 0xffffffff;
- H2 = (H2+c) & 0xffffffff;
- H3 = (H3+d) & 0xffffffff;
- H4 = (H4+e) & 0xffffffff;
- }
- return Sha1.toHexStr(H0) + Sha1.toHexStr(H1) + Sha1.toHexStr(H2) +
- Sha1.toHexStr(H3) + Sha1.toHexStr(H4);
- };
- /**
- * Function 'f' [§4.1.1].
- * @private
- */
- Sha1.f = function(s, x, y, z) {
- switch (s) {
- case 0: return (x & y) ^ (~x & z); // Ch()
- case 1: return x ^ y ^ z; // Parity()
- case 2: return (x & y) ^ (x & z) ^ (y & z); // Maj()
- case 3: return x ^ y ^ z; // Parity()
- }
- };
- /**
- * Rotates left (circular left shift) value x by n positions [§3.2.5].
- * @private
- */
- Sha1.ROTL = function(x, n) {
- return (x<<n) | (x>>>(32-n));
- };
- /**
- * Hexadecimal representation of a number.
- * @private
- */
- Sha1.toHexStr = function(n) {
- // note can't use toString(16) as it is implementation-dependant,
- // and in IE returns signed numbers when used on full words
- var s="", v;
- for (var i=7; i>=0; i--) { v = (n>>>(i*4)) & 0xf; s += v.toString(16); }
- return s;
- };
- /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
- /** Extend String object with method to encode multi-byte string to utf8
- * - monsur.hossa.in/2012/07/20/utf-8-in-javascript.html */
- if (typeof String.prototype.utf8Encode == 'undefined') {
- String.prototype.utf8Encode = function() {
- return unescape( encodeURIComponent( this ) );
- };
- }
- /** Extend String object with method to decode utf8 string to multi-byte */
- if (typeof String.prototype.utf8Decode == 'undefined') {
- String.prototype.utf8Decode = function() {
- try {
- return decodeURIComponent( escape( this ) );
- } catch (e) {
- return this; // invalid UTF-8? return as-is
- }
- };
- }
- /* - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - */
- if (typeof module != 'undefined' && module.exports) module.exports = Sha1; // CommonJs export
- if (typeof define == 'function' && define.amd) define([], function() { return Sha1; }); // AMD
- })(window)
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