| // Copyright 2014 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| // SHA256 in javascript. |
| // |
| // SHA256 { |
| // SHA256(); |
| // void reset(); |
| // void update(byte[] data, opt_length); |
| // byte[32] digest(); |
| // } |
| |
| /** @constructor */ |
| function SHA256() { |
| this._buf = new Array(64); |
| this._W = new Array(64); |
| this._pad = new Array(64); |
| this._k = [ |
| 0x428a2f98, 0x71374491, 0xb5c0fbcf, 0xe9b5dba5, |
| 0x3956c25b, 0x59f111f1, 0x923f82a4, 0xab1c5ed5, |
| 0xd807aa98, 0x12835b01, 0x243185be, 0x550c7dc3, |
| 0x72be5d74, 0x80deb1fe, 0x9bdc06a7, 0xc19bf174, |
| 0xe49b69c1, 0xefbe4786, 0x0fc19dc6, 0x240ca1cc, |
| 0x2de92c6f, 0x4a7484aa, 0x5cb0a9dc, 0x76f988da, |
| 0x983e5152, 0xa831c66d, 0xb00327c8, 0xbf597fc7, |
| 0xc6e00bf3, 0xd5a79147, 0x06ca6351, 0x14292967, |
| 0x27b70a85, 0x2e1b2138, 0x4d2c6dfc, 0x53380d13, |
| 0x650a7354, 0x766a0abb, 0x81c2c92e, 0x92722c85, |
| 0xa2bfe8a1, 0xa81a664b, 0xc24b8b70, 0xc76c51a3, |
| 0xd192e819, 0xd6990624, 0xf40e3585, 0x106aa070, |
| 0x19a4c116, 0x1e376c08, 0x2748774c, 0x34b0bcb5, |
| 0x391c0cb3, 0x4ed8aa4a, 0x5b9cca4f, 0x682e6ff3, |
| 0x748f82ee, 0x78a5636f, 0x84c87814, 0x8cc70208, |
| 0x90befffa, 0xa4506ceb, 0xbef9a3f7, 0xc67178f2]; |
| |
| this._pad[0] = 0x80; |
| for (var i = 1; i < 64; ++i) this._pad[i] = 0; |
| |
| this.reset(); |
| } |
| |
| /** Reset the hasher */ |
| SHA256.prototype.reset = function() { |
| this._chain = [ |
| 0x6a09e667, 0xbb67ae85, 0x3c6ef372, 0xa54ff53a, |
| 0x510e527f, 0x9b05688c, 0x1f83d9ab, 0x5be0cd19]; |
| |
| this._inbuf = 0; |
| this._total = 0; |
| }; |
| |
| /** Hash the next block of 64 bytes |
| * @param {Array.<number>} buf A 64 byte buffer |
| */ |
| SHA256.prototype._compress = function(buf) { |
| var W = this._W; |
| var k = this._k; |
| |
| function _rotr(w, r) { return ((w << (32 - r)) | (w >>> r)); }; |
| |
| // get 16 big endian words |
| for (var i = 0; i < 64; i += 4) { |
| var w = (buf[i] << 24) | |
| (buf[i + 1] << 16) | |
| (buf[i + 2] << 8) | |
| (buf[i + 3]); |
| W[i / 4] = w; |
| } |
| |
| // expand to 64 words |
| for (var i = 16; i < 64; ++i) { |
| var s0 = _rotr(W[i - 15], 7) ^ _rotr(W[i - 15], 18) ^ (W[i - 15] >>> 3); |
| var s1 = _rotr(W[i - 2], 17) ^ _rotr(W[i - 2], 19) ^ (W[i - 2] >>> 10); |
| W[i] = (W[i - 16] + s0 + W[i - 7] + s1) & 0xffffffff; |
| } |
| |
| var A = this._chain[0]; |
| var B = this._chain[1]; |
| var C = this._chain[2]; |
| var D = this._chain[3]; |
| var E = this._chain[4]; |
| var F = this._chain[5]; |
| var G = this._chain[6]; |
| var H = this._chain[7]; |
| |
| for (var i = 0; i < 64; ++i) { |
| var S0 = _rotr(A, 2) ^ _rotr(A, 13) ^ _rotr(A, 22); |
| var maj = (A & B) ^ (A & C) ^ (B & C); |
| var t2 = (S0 + maj) & 0xffffffff; |
| var S1 = _rotr(E, 6) ^ _rotr(E, 11) ^ _rotr(E, 25); |
| var ch = (E & F) ^ ((~E) & G); |
| var t1 = (H + S1 + ch + k[i] + W[i]) & 0xffffffff; |
| |
| H = G; |
| G = F; |
| F = E; |
| E = (D + t1) & 0xffffffff; |
| D = C; |
| C = B; |
| B = A; |
| A = (t1 + t2) & 0xffffffff; |
| } |
| |
| this._chain[0] += A; |
| this._chain[1] += B; |
| this._chain[2] += C; |
| this._chain[3] += D; |
| this._chain[4] += E; |
| this._chain[5] += F; |
| this._chain[6] += G; |
| this._chain[7] += H; |
| }; |
| |
| /** Update the hash with additional data |
| * @param {Array.<number>|Uint8Array} bytes The data |
| * @param {number=} opt_length How many bytes to hash, if not all */ |
| SHA256.prototype.update = function(bytes, opt_length) { |
| if (!opt_length) opt_length = bytes.length; |
| |
| this._total += opt_length; |
| for (var n = 0; n < opt_length; ++n) { |
| this._buf[this._inbuf++] = bytes[n]; |
| if (this._inbuf == 64) { |
| this._compress(this._buf); |
| this._inbuf = 0; |
| } |
| } |
| }; |
| |
| /** Update the hash with a specified range from a data buffer |
| * @param {Array.<number>} bytes The data buffer |
| * @param {number} start Starting index of the range in bytes |
| * @param {number} end End index, will not be included in range |
| */ |
| SHA256.prototype.updateRange = function(bytes, start, end) { |
| this._total += (end - start); |
| for (var n = start; n < end; ++n) { |
| this._buf[this._inbuf++] = bytes[n]; |
| if (this._inbuf == 64) { |
| this._compress(this._buf); |
| this._inbuf = 0; |
| } |
| } |
| }; |
| |
| /** |
| * Optionally update the hash with additional arguments, and return the |
| * resulting hash value. |
| * @param {...*} var_args Data buffers to hash |
| * @return {Array.<number>} the SHA256 hash value. |
| */ |
| SHA256.prototype.digest = function(var_args) { |
| for (var i = 0; i < arguments.length; ++i) |
| this.update(arguments[i]); |
| |
| var digest = new Array(32); |
| var totalBits = this._total * 8; |
| |
| // add pad 0x80 0x00* |
| if (this._inbuf < 56) |
| this.update(this._pad, 56 - this._inbuf); |
| else |
| this.update(this._pad, 64 - (this._inbuf - 56)); |
| |
| // add # bits, big endian |
| for (var i = 63; i >= 56; --i) { |
| this._buf[i] = totalBits & 255; |
| totalBits >>>= 8; |
| } |
| |
| this._compress(this._buf); |
| |
| var n = 0; |
| for (var i = 0; i < 8; ++i) |
| for (var j = 24; j >= 0; j -= 8) |
| digest[n++] = (this._chain[i] >> j) & 255; |
| |
| return digest; |
| }; |