chrome/browser/resources/cryptotoken/sha256.js

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 /** @fileoverview SHA256 in javascript */
   6 // SHA256 {
   7 //  SHA256();
   8 //  void reset();
   9 //  void update(byte[] data, opt_length);
  10 //  byte[32] digest();
  11 // }
  12
  13 /** @constructor */
  14 function SHA256() {
  15   this._buf = new Array(64);
  16   this._W = new Array(64);
  17   this._pad = new Array(64);
  18   this._k = [
  19    0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5,
  20    0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5,
  21    0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3,
  22    0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174,
  23    0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc,
  24    0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da,
  25    0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7,
  26    0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967,
  27    0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13,
  28    0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85,
  29    0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3,
  30    0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070,
  31    0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5,
  32    0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3,
  33    0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208,
  34    0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2];
  35
  36   this._pad[0] = 0x80;
  37   for (var i = 1; i < 64; ++i) this._pad[i] = 0;
  38
  39   this.reset();
  40 }
  41
  42 /** Reset the hasher */
  43 SHA256.prototype.reset = function() {
  44   this._chain = [
  45     0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a,
  46     0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19];
  47
  48   this._inbuf = 0;
  49   this._total = 0;
  50 };
  51
  52 /** Hash the next block of 64 bytes
  53  * @param {Array.<number>} buf A 64 byte buffer
  54  */
  55 SHA256.prototype._compress = function(buf) {
  56   var W = this._W;
  57   var k = this._k;
  58
  59   function _rotr(w, r) { return ((w << (32 - r)) | (w >>> r)); };
  60
  61   // get 16 big endian words
  62   for (var i = 0; i < 64; i += 4) {
  63     var w = (buf[i] << 24) |
  64             (buf[i + 1] << 16) |
  65             (buf[i + 2] << 8) |
  66             (buf[i + 3]);
  67     W[i / 4] = w;
  68   }
  69
  70   // expand to 64 words
  71   for (var i = 16; i < 64; ++i) {
  72     var s0 = _rotr(W[i - 15], 7) ^ _rotr(W[i - 15], 18) ^ (W[i - 15] >>> 3);
  73     var s1 = _rotr(W[i - 2], 17) ^ _rotr(W[i - 2], 19) ^ (W[i - 2] >>> 10);
  74     W[i] = (W[i - 16] + s0 + W[i - 7] + s1) & 0xffffffff;
  75   }
  76
  77   var A = this._chain[0];
  78   var B = this._chain[1];
  79   var C = this._chain[2];
  80   var D = this._chain[3];
  81   var E = this._chain[4];
  82   var F = this._chain[5];
  83   var G = this._chain[6];
  84   var H = this._chain[7];
  85
  86   for (var i = 0; i < 64; ++i) {
  87     var S0 = _rotr(A, 2) ^ _rotr(A, 13) ^ _rotr(A, 22);
  88     var maj = (A & B) ^ (A & C) ^ (B & C);
  89     var t2 = (S0 + maj) & 0xffffffff;
  90     var S1 = _rotr(E, 6) ^ _rotr(E, 11) ^ _rotr(E, 25);
  91     var ch = (E & F) ^ ((~E) & G);
  92     var t1 = (H + S1 + ch + k[i] + W[i]) & 0xffffffff;
  93
  94     H = G;
  95     G = F;
  96     F = E;
  97     E = (D + t1) & 0xffffffff;
  98     D = C;
  99     C = B;
 100     B = A;
 101     A = (t1 + t2) & 0xffffffff;
 102   }
 103
 104   this._chain[0] += A;
 105   this._chain[1] += B;
 106   this._chain[2] += C;
 107   this._chain[3] += D;
 108   this._chain[4] += E;
 109   this._chain[5] += F;
 110   this._chain[6] += G;
 111   this._chain[7] += H;
 112 };
 113
 114 /** Update the hash with additional data
 115  * @param {Array.<number>|Uint8Array} bytes The data
 116  * @param {number=} opt_length How many bytes to hash, if not all */
 117 SHA256.prototype.update = function(bytes, opt_length) {
 118   if (!opt_length) opt_length = bytes.length;
 119
 120   this._total += opt_length;
 121   for (var n = 0; n < opt_length; ++n) {
 122     this._buf[this._inbuf++] = bytes[n];
 123     if (this._inbuf == 64) {
 124       this._compress(this._buf);
 125       this._inbuf = 0;
 126     }
 127   }
 128 };
 129
 130 /** Update the hash with a specified range from a data buffer
 131  * @param {Array.<number>} bytes The data buffer
 132  * @param {number} start Starting index of the range in bytes
 133  * @param {number} end End index, will not be included in range
 134  */
 135 SHA256.prototype.updateRange = function(bytes, start, end) {
 136   this._total += (end - start);
 137   for (var n = start; n < end; ++n) {
 138     this._buf[this._inbuf++] = bytes[n];
 139     if (this._inbuf == 64) {
 140       this._compress(this._buf);
 141       this._inbuf = 0;
 142     }
 143   }
 144 };
 145
 146 /**
 147  * Optionally update the hash with additional arguments, and return the
 148  * resulting hash value.
 149  * @param {...*} var_args Data buffers to hash
 150  * @return {Array.<number>} the SHA256 hash value.
 151  */
 152 SHA256.prototype.digest = function(var_args) {
 153   for (var i = 0; i < arguments.length; ++i)
 154     this.update(arguments[i]);
 155
 156   var digest = new Array(32);
 157   var totalBits = this._total * 8;
 158
 159   // add pad 0x80 0x00*
 160   if (this._inbuf < 56)
 161     this.update(this._pad, 56 - this._inbuf);
 162   else
 163     this.update(this._pad, 64 - (this._inbuf - 56));
 164
 165   // add # bits, big endian
 166   for (var i = 63; i >= 56; --i) {
 167     this._buf[i] = totalBits & 255;
 168     totalBits >>>= 8;
 169   }
 170
 171   this._compress(this._buf);
 172
 173   var n = 0;
 174   for (var i = 0; i < 8; ++i)
 175     for (var j = 24; j >= 0; j -= 8)
 176       digest[n++] = (this._chain[i] >> j) & 255;
 177
 178   return digest;
 179 };