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Diffstat (limited to 'school/node_modules/node-forge/js/sha256.js')
| -rw-r--r-- | school/node_modules/node-forge/js/sha256.js | 352 |
1 files changed, 352 insertions, 0 deletions
diff --git a/school/node_modules/node-forge/js/sha256.js b/school/node_modules/node-forge/js/sha256.js new file mode 100644 index 0000000..fdbc4fc --- /dev/null +++ b/school/node_modules/node-forge/js/sha256.js @@ -0,0 +1,352 @@ +/** + * Secure Hash Algorithm with 256-bit digest (SHA-256) implementation. + * + * See FIPS 180-2 for details. + * + * @author Dave Longley + * + * Copyright (c) 2010-2014 Digital Bazaar, Inc. + */ +(function() { +/* ########## Begin module implementation ########## */ +function initModule(forge) { + +var sha256 = forge.sha256 = forge.sha256 || {}; +forge.md = forge.md || {}; +forge.md.algorithms = forge.md.algorithms || {}; +forge.md.sha256 = forge.md.algorithms.sha256 = sha256; + +/** + * Creates a SHA-256 message digest object. + * + * @return a message digest object. + */ +sha256.create = function() { + // do initialization as necessary + if(!_initialized) { + _init(); + } + + // SHA-256 state contains eight 32-bit integers + var _state = null; + + // input buffer + var _input = forge.util.createBuffer(); + + // used for word storage + var _w = new Array(64); + + // message digest object + var md = { + algorithm: 'sha256', + blockLength: 64, + digestLength: 32, + // 56-bit length of message so far (does not including padding) + messageLength: 0, + // true 64-bit message length as two 32-bit ints + messageLength64: [0, 0] + }; + + /** + * Starts the digest. + * + * @return this digest object. + */ + md.start = function() { + md.messageLength = 0; + md.messageLength64 = [0, 0]; + _input = forge.util.createBuffer(); + _state = { + h0: 0x6A09E667, + h1: 0xBB67AE85, + h2: 0x3C6EF372, + h3: 0xA54FF53A, + h4: 0x510E527F, + h5: 0x9B05688C, + h6: 0x1F83D9AB, + h7: 0x5BE0CD19 + }; + return md; + }; + // start digest automatically for first time + md.start(); + + /** + * Updates the digest with the given message input. The given input can + * treated as raw input (no encoding will be applied) or an encoding of + * 'utf8' maybe given to encode the input using UTF-8. + * + * @param msg the message input to update with. + * @param encoding the encoding to use (default: 'raw', other: 'utf8'). + * + * @return this digest object. + */ + md.update = function(msg, encoding) { + if(encoding === 'utf8') { + msg = forge.util.encodeUtf8(msg); + } + + // update message length + md.messageLength += msg.length; + md.messageLength64[0] += (msg.length / 0x100000000) >>> 0; + md.messageLength64[1] += msg.length >>> 0; + + // add bytes to input buffer + _input.putBytes(msg); + + // process bytes + _update(_state, _w, _input); + + // compact input buffer every 2K or if empty + if(_input.read > 2048 || _input.length() === 0) { + _input.compact(); + } + + return md; + }; + + /** + * Produces the digest. + * + * @return a byte buffer containing the digest value. + */ + md.digest = function() { + /* Note: Here we copy the remaining bytes in the input buffer and + add the appropriate SHA-256 padding. Then we do the final update + on a copy of the state so that if the user wants to get + intermediate digests they can do so. */ + + /* Determine the number of bytes that must be added to the message + to ensure its length is congruent to 448 mod 512. In other words, + the data to be digested must be a multiple of 512 bits (or 128 bytes). + This data includes the message, some padding, and the length of the + message. Since the length of the message will be encoded as 8 bytes (64 + bits), that means that the last segment of the data must have 56 bytes + (448 bits) of message and padding. Therefore, the length of the message + plus the padding must be congruent to 448 mod 512 because + 512 - 128 = 448. + + In order to fill up the message length it must be filled with + padding that begins with 1 bit followed by all 0 bits. Padding + must *always* be present, so if the message length is already + congruent to 448 mod 512, then 512 padding bits must be added. */ + + // 512 bits == 64 bytes, 448 bits == 56 bytes, 64 bits = 8 bytes + // _padding starts with 1 byte with first bit is set in it which + // is byte value 128, then there may be up to 63 other pad bytes + var padBytes = forge.util.createBuffer(); + padBytes.putBytes(_input.bytes()); + // 64 - (remaining msg + 8 bytes msg length) mod 64 + padBytes.putBytes( + _padding.substr(0, 64 - ((md.messageLength64[1] + 8) & 0x3F))); + + /* Now append length of the message. The length is appended in bits + as a 64-bit number in big-endian order. Since we store the length in + bytes, we must multiply the 64-bit length by 8 (or left shift by 3). */ + padBytes.putInt32( + (md.messageLength64[0] << 3) | (md.messageLength64[0] >>> 28)); + padBytes.putInt32(md.messageLength64[1] << 3); + var s2 = { + h0: _state.h0, + h1: _state.h1, + h2: _state.h2, + h3: _state.h3, + h4: _state.h4, + h5: _state.h5, + h6: _state.h6, + h7: _state.h7 + }; + _update(s2, _w, padBytes); + var rval = forge.util.createBuffer(); + rval.putInt32(s2.h0); + rval.putInt32(s2.h1); + rval.putInt32(s2.h2); + rval.putInt32(s2.h3); + rval.putInt32(s2.h4); + rval.putInt32(s2.h5); + rval.putInt32(s2.h6); + rval.putInt32(s2.h7); + return rval; + }; + + return md; +}; + +// sha-256 padding bytes not initialized yet +var _padding = null; +var _initialized = false; + +// table of constants +var _k = null; + +/** + * Initializes the constant tables. + */ +function _init() { + // create padding + _padding = String.fromCharCode(128); + _padding += forge.util.fillString(String.fromCharCode(0x00), 64); + + // create K table for SHA-256 + _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]; + + // now initialized + _initialized = true; +} + +/** + * Updates a SHA-256 state with the given byte buffer. + * + * @param s the SHA-256 state to update. + * @param w the array to use to store words. + * @param bytes the byte buffer to update with. + */ +function _update(s, w, bytes) { + // consume 512 bit (64 byte) chunks + var t1, t2, s0, s1, ch, maj, i, a, b, c, d, e, f, g, h; + var len = bytes.length(); + while(len >= 64) { + // the w array will be populated with sixteen 32-bit big-endian words + // and then extended into 64 32-bit words according to SHA-256 + for(i = 0; i < 16; ++i) { + w[i] = bytes.getInt32(); + } + for(; i < 64; ++i) { + // XOR word 2 words ago rot right 17, rot right 19, shft right 10 + t1 = w[i - 2]; + t1 = + ((t1 >>> 17) | (t1 << 15)) ^ + ((t1 >>> 19) | (t1 << 13)) ^ + (t1 >>> 10); + // XOR word 15 words ago rot right 7, rot right 18, shft right 3 + t2 = w[i - 15]; + t2 = + ((t2 >>> 7) | (t2 << 25)) ^ + ((t2 >>> 18) | (t2 << 14)) ^ + (t2 >>> 3); + // sum(t1, word 7 ago, t2, word 16 ago) modulo 2^32 + w[i] = (t1 + w[i - 7] + t2 + w[i - 16]) | 0; + } + + // initialize hash value for this chunk + a = s.h0; + b = s.h1; + c = s.h2; + d = s.h3; + e = s.h4; + f = s.h5; + g = s.h6; + h = s.h7; + + // round function + for(i = 0; i < 64; ++i) { + // Sum1(e) + s1 = + ((e >>> 6) | (e << 26)) ^ + ((e >>> 11) | (e << 21)) ^ + ((e >>> 25) | (e << 7)); + // Ch(e, f, g) (optimized the same way as SHA-1) + ch = g ^ (e & (f ^ g)); + // Sum0(a) + s0 = + ((a >>> 2) | (a << 30)) ^ + ((a >>> 13) | (a << 19)) ^ + ((a >>> 22) | (a << 10)); + // Maj(a, b, c) (optimized the same way as SHA-1) + maj = (a & b) | (c & (a ^ b)); + + // main algorithm + t1 = h + s1 + ch + _k[i] + w[i]; + t2 = s0 + maj; + h = g; + g = f; + f = e; + e = (d + t1) | 0; + d = c; + c = b; + b = a; + a = (t1 + t2) | 0; + } + + // update hash state + s.h0 = (s.h0 + a) | 0; + s.h1 = (s.h1 + b) | 0; + s.h2 = (s.h2 + c) | 0; + s.h3 = (s.h3 + d) | 0; + s.h4 = (s.h4 + e) | 0; + s.h5 = (s.h5 + f) | 0; + s.h6 = (s.h6 + g) | 0; + s.h7 = (s.h7 + h) | 0; + len -= 64; + } +} + +} // end module implementation + +/* ########## Begin module wrapper ########## */ +var name = 'sha256'; +if(typeof define !== 'function') { + // NodeJS -> AMD + if(typeof module === 'object' && module.exports) { + var nodeJS = true; + define = function(ids, factory) { + factory(require, module); + }; + } else { + // <script> + if(typeof forge === 'undefined') { + forge = {}; + } + return initModule(forge); + } +} +// AMD +var deps; +var defineFunc = function(require, module) { + module.exports = function(forge) { + var mods = deps.map(function(dep) { + return require(dep); + }).concat(initModule); + // handle circular dependencies + forge = forge || {}; + forge.defined = forge.defined || {}; + if(forge.defined[name]) { + return forge[name]; + } + forge.defined[name] = true; + for(var i = 0; i < mods.length; ++i) { + mods[i](forge); + } + return forge[name]; + }; +}; +var tmpDefine = define; +define = function(ids, factory) { + deps = (typeof ids === 'string') ? factory.slice(2) : ids.slice(2); + if(nodeJS) { + delete define; + return tmpDefine.apply(null, Array.prototype.slice.call(arguments, 0)); + } + define = tmpDefine; + return define.apply(null, Array.prototype.slice.call(arguments, 0)); +}; +define(['require', 'module', './util'], function() { + defineFunc.apply(null, Array.prototype.slice.call(arguments, 0)); +}); +})(); |