| /** |
| * Message Digest Algorithm 5 with 128-bit digest (MD5) implementation. |
| * |
| * @author Dave Longley |
| * |
| * Copyright (c) 2010-2014 Digital Bazaar, Inc. |
| */ |
| var forge = require('./forge'); |
| require('./md'); |
| require('./util'); |
| |
| var md5 = module.exports = forge.md5 = forge.md5 || {}; |
| forge.md.md5 = forge.md.algorithms.md5 = md5; |
| |
| /** |
| * Creates an MD5 message digest object. |
| * |
| * @return a message digest object. |
| */ |
| md5.create = function() { |
| // do initialization as necessary |
| if(!_initialized) { |
| _init(); |
| } |
| |
| // MD5 state contains four 32-bit integers |
| var _state = null; |
| |
| // input buffer |
| var _input = forge.util.createBuffer(); |
| |
| // used for word storage |
| var _w = new Array(16); |
| |
| // message digest object |
| var md = { |
| algorithm: 'md5', |
| blockLength: 64, |
| digestLength: 16, |
| // 56-bit length of message so far (does not including padding) |
| messageLength: 0, |
| // true message length |
| fullMessageLength: null, |
| // size of message length in bytes |
| messageLengthSize: 8 |
| }; |
| |
| /** |
| * Starts the digest. |
| * |
| * @return this digest object. |
| */ |
| md.start = function() { |
| // up to 56-bit message length for convenience |
| md.messageLength = 0; |
| |
| // full message length (set md.messageLength64 for backwards-compatibility) |
| md.fullMessageLength = md.messageLength64 = []; |
| var int32s = md.messageLengthSize / 4; |
| for(var i = 0; i < int32s; ++i) { |
| md.fullMessageLength.push(0); |
| } |
| _input = forge.util.createBuffer(); |
| _state = { |
| h0: 0x67452301, |
| h1: 0xEFCDAB89, |
| h2: 0x98BADCFE, |
| h3: 0x10325476 |
| }; |
| 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 |
| var len = msg.length; |
| md.messageLength += len; |
| len = [(len / 0x100000000) >>> 0, len >>> 0]; |
| for(var i = md.fullMessageLength.length - 1; i >= 0; --i) { |
| md.fullMessageLength[i] += len[1]; |
| len[1] = len[0] + ((md.fullMessageLength[i] / 0x100000000) >>> 0); |
| md.fullMessageLength[i] = md.fullMessageLength[i] >>> 0; |
| len[0] = (len[1] / 0x100000000) >>> 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 MD5 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. */ |
| |
| var finalBlock = forge.util.createBuffer(); |
| finalBlock.putBytes(_input.bytes()); |
| |
| // compute remaining size to be digested (include message length size) |
| var remaining = ( |
| md.fullMessageLength[md.fullMessageLength.length - 1] + |
| md.messageLengthSize); |
| |
| // add padding for overflow blockSize - overflow |
| // _padding starts with 1 byte with first bit is set (byte value 128), then |
| // there may be up to (blockSize - 1) other pad bytes |
| var overflow = remaining & (md.blockLength - 1); |
| finalBlock.putBytes(_padding.substr(0, md.blockLength - overflow)); |
| |
| // serialize message length in bits in little-endian order; since length |
| // is stored in bytes we multiply by 8 and add carry |
| var bits, carry = 0; |
| for(var i = md.fullMessageLength.length - 1; i >= 0; --i) { |
| bits = md.fullMessageLength[i] * 8 + carry; |
| carry = (bits / 0x100000000) >>> 0; |
| finalBlock.putInt32Le(bits >>> 0); |
| } |
| |
| var s2 = { |
| h0: _state.h0, |
| h1: _state.h1, |
| h2: _state.h2, |
| h3: _state.h3 |
| }; |
| _update(s2, _w, finalBlock); |
| var rval = forge.util.createBuffer(); |
| rval.putInt32Le(s2.h0); |
| rval.putInt32Le(s2.h1); |
| rval.putInt32Le(s2.h2); |
| rval.putInt32Le(s2.h3); |
| return rval; |
| }; |
| |
| return md; |
| }; |
| |
| // padding, constant tables for calculating md5 |
| var _padding = null; |
| var _g = null; |
| var _r = null; |
| var _k = null; |
| var _initialized = false; |
| |
| /** |
| * Initializes the constant tables. |
| */ |
| function _init() { |
| // create padding |
| _padding = String.fromCharCode(128); |
| _padding += forge.util.fillString(String.fromCharCode(0x00), 64); |
| |
| // g values |
| _g = [ |
| 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, |
| 1, 6, 11, 0, 5, 10, 15, 4, 9, 14, 3, 8, 13, 2, 7, 12, |
| 5, 8, 11, 14, 1, 4, 7, 10, 13, 0, 3, 6, 9, 12, 15, 2, |
| 0, 7, 14, 5, 12, 3, 10, 1, 8, 15, 6, 13, 4, 11, 2, 9]; |
| |
| // rounds table |
| _r = [ |
| 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]; |
| |
| // get the result of abs(sin(i + 1)) as a 32-bit integer |
| _k = new Array(64); |
| for(var i = 0; i < 64; ++i) { |
| _k[i] = Math.floor(Math.abs(Math.sin(i + 1)) * 0x100000000); |
| } |
| |
| // now initialized |
| _initialized = true; |
| } |
| |
| /** |
| * Updates an MD5 state with the given byte buffer. |
| * |
| * @param s the MD5 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 t, a, b, c, d, f, r, i; |
| var len = bytes.length(); |
| while(len >= 64) { |
| // initialize hash value for this chunk |
| a = s.h0; |
| b = s.h1; |
| c = s.h2; |
| d = s.h3; |
| |
| // round 1 |
| for(i = 0; i < 16; ++i) { |
| w[i] = bytes.getInt32Le(); |
| f = d ^ (b & (c ^ d)); |
| t = (a + f + _k[i] + w[i]); |
| r = _r[i]; |
| a = d; |
| d = c; |
| c = b; |
| b += (t << r) | (t >>> (32 - r)); |
| } |
| // round 2 |
| for(; i < 32; ++i) { |
| f = c ^ (d & (b ^ c)); |
| t = (a + f + _k[i] + w[_g[i]]); |
| r = _r[i]; |
| a = d; |
| d = c; |
| c = b; |
| b += (t << r) | (t >>> (32 - r)); |
| } |
| // round 3 |
| for(; i < 48; ++i) { |
| f = b ^ c ^ d; |
| t = (a + f + _k[i] + w[_g[i]]); |
| r = _r[i]; |
| a = d; |
| d = c; |
| c = b; |
| b += (t << r) | (t >>> (32 - r)); |
| } |
| // round 4 |
| for(; i < 64; ++i) { |
| f = c ^ (b | ~d); |
| t = (a + f + _k[i] + w[_g[i]]); |
| r = _r[i]; |
| a = d; |
| d = c; |
| c = b; |
| b += (t << r) | (t >>> (32 - r)); |
| } |
| |
| // 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; |
| |
| len -= 64; |
| } |
| } |