В общем, раскопал я в сети реализацию MD5 на JavaScript. Вещь показалась мне интересной, поэтому и решил поделиться с общественностью:
// md5.js source code
//------------------------------------------------------------------
/*
* A JavaScript implementation of the RSA Data Security, Inc. MD5 Message
* Digest Algorithm, as defined in RFC 1321.
* Version 2.0 Copyright (C) Paul Johnston 1999 - 2002.
* Other contributors: Greg Holt, Ydnar
* Distributed under the Lesser GNU Public License (LGPL)
* See http://pajhome.org.uk/crypt/md5 for more info.
*/
/*
* Configurable variables. You may need to tweak these to be compatible with
* the server-side, but the defaults work in most cases.
*/
var hexcase = 0 /* hex output format. 0 - lowercase; 1 - uppercase */
var b64pad = "" /* base-64 pad character. "=" for strict RFC compliance */
var chrsz = 8 /* bits per input character. 8 - ASCII; 16 - Unicode */
/*
* These are the functions you'll usually want to call
* They take string arguments and return either hex or base-64 encoded strings
*/
function hex_md5(s){ return binl2hex(core_md5(str2binl(s), s.length * chrsz)) }
function b64_md5(s){ return binl2b64(core_md5(str2binl(s), s.length * chrsz)) }
function hex_hmac_md5(key, data) { return binl2hex(core_hmac_md5(key, data)) }
function b64_hmac_md5(key, data) { return binl2b64(core_hmac_md5(key, data)) }
/* Backwards compatibility - same as hex_md5() */
function calcMD5(s){ return binl2hex(core_md5(str2binl(s), s.length * chrsz)) }
/*
* Perform a simple self-test to see if the VM is working
*/
function md5_vm_test()
{
return hex_md5("abc") == "900150983cd24fb0d6963f7d28e17f72"
}
/*
* Calculate the MD5 of an array of little-endian words, and a bit length
*/
function core_md5(x, len)
{
/* append padding */
x[len >> 5] |= 0x80 << ((len) % 32)
x[(((len + 64) >>> 9) << 4) + 14] = len
var a = 1732584193
var b = -271733879
var c = -1732584194
var d = 271733878
for(i = 0; i < x.length; i += 16)
{
var olda = a
var oldb = b
var oldc = c
var oldd = d
a = ff(a, b, c, d, x[i+ 0], 7 , -680876936)
d = ff(d, a, b, c, x[i+ 1], 12, -389564586)
c = ff(c, d, a, b, x[i+ 2], 17, 606105819)
b = ff(b, c, d, a, x[i+ 3], 22, -1044525330)
a = ff(a, b, c, d, x[i+ 4], 7 , -176418897)
d = ff(d, a, b, c, x[i+ 5], 12, 1200080426)
c = ff(c, d, a, b, x[i+ 6], 17, -1473231341)
b = ff(b, c, d, a, x[i+ 7], 22, -45705983)
a = ff(a, b, c, d, x[i+ 8], 7 , 1770035416)
d = ff(d, a, b, c, x[i+ 9], 12, -1958414417)
c = ff(c, d, a, b, x[i+10], 17, -42063)
b = ff(b, c, d, a, x[i+11], 22, -1990404162)
a = ff(a, b, c, d, x[i+12], 7 , 1804603682)
d = ff(d, a, b, c, x[i+13], 12, -40341101)
c = ff(c, d, a, b, x[i+14], 17, -1502002290)
b = ff(b, c, d, a, x[i+15], 22, 1236535329)
a = gg(a, b, c, d, x[i+ 1], 5 , -165796510)
d = gg(d, a, b, c, x[i+ 6], 9 , -1069501632)
c = gg(c, d, a, b, x[i+11], 14, 643717713)
b = gg(b, c, d, a, x[i+ 0], 20, -373897302)
a = gg(a, b, c, d, x[i+ 5], 5 , -701558691)
d = gg(d, a, b, c, x[i+10], 9 , 38016083)
c = gg(c, d, a, b, x[i+15], 14, -660478335)
b = gg(b, c, d, a, x[i+ 4], 20, -405537848)
a = gg(a, b, c, d, x[i+ 9], 5 , 568446438)
d = gg(d, a, b, c, x[i+14], 9 , -1019803690)
c = gg(c, d, a, b, x[i+ 3], 14, -187363961)
b = gg(b, c, d, a, x[i+ 8], 20, 1163531501)
a = gg(a, b, c, d, x[i+13], 5 , -1444681467)
d = gg(d, a, b, c, x[i+ 2], 9 , -51403784)
c = gg(c, d, a, b, x[i+ 7], 14, 1735328473)
b = gg(b, c, d, a, x[i+12], 20, -1926607734)
a = hh(a, b, c, d, x[i+ 5], 4 , -378558)
d = hh(d, a, b, c, x[i+ 8], 11, -2022574463)
c = hh(c, d, a, b, x[i+11], 16, 1839030562)
b = hh(b, c, d, a, x[i+14], 23, -35309556)
a = hh(a, b, c, d, x[i+ 1], 4 , -1530992060)
d = hh(d, a, b, c, x[i+ 4], 11, 1272893353)
c = hh(c, d, a, b, x[i+ 7], 16, -155497632)
b = hh(b, c, d, a, x[i+10], 23, -1094730640)
a = hh(a, b, c, d, x[i+13], 4 , 681279174)
d = hh(d, a, b, c, x[i+ 0], 11, -358537222)
c = hh(c, d, a, b, x[i+ 3], 16, -722521979)
b = hh(b, c, d, a, x[i+ 6], 23, 76029189)
a = hh(a, b, c, d, x[i+ 9], 4 , -640364487)
d = hh(d, a, b, c, x[i+12], 11, -421815835)
c = hh(c, d, a, b, x[i+15], 16, 530742520)
b = hh(b, c, d, a, x[i+ 2], 23, -995338651)
a = ii(a, b, c, d, x[i+ 0], 6 , -198630844)
d = ii(d, a, b, c, x[i+ 7], 10, 1126891415)
c = ii(c, d, a, b, x[i+14], 15, -1416354905)
b = ii(b, c, d, a, x[i+ 5], 21, -57434055)
a = ii(a, b, c, d, x[i+12], 6 , 1700485571)
d = ii(d, a, b, c, x[i+ 3], 10, -1894986606)
c = ii(c, d, a, b, x[i+10], 15, -1051523)
b = ii(b, c, d, a, x[i+ 1], 21, -2054922799)
a = ii(a, b, c, d, x[i+ 8], 6 , 1873313359)
d = ii(d, a, b, c, x[i+15], 10, -30611744)
c = ii(c, d, a, b, x[i+ 6], 15, -1560198380)
b = ii(b, c, d, a, x[i+13], 21, 1309151649)
a = ii(a, b, c, d, x[i+ 4], 6 , -145523070)
d = ii(d, a, b, c, x[i+11], 10, -1120210379)
c = ii(c, d, a, b, x[i+ 2], 15, 718787259)
b = ii(b, c, d, a, x[i+ 9], 21, -343485551)
a = safe_add(a, olda)
b = safe_add(b, oldb)
c = safe_add(c, oldc)
d = safe_add(d, oldd)
}
return Array(a, b, c, d)
/*
* These functions implement the four basic operations the algorithm uses.
*/
function cmn(q, a, b, x, s, t)
{
return safe_add(rol(safe_add(safe_add(a, q), safe_add(x, t)), s), b)
}
function ff(a, b, c, d, x, s, t)
{
return cmn((b & c) | ((~b) & d), a, b, x, s, t)
}
function gg(a, b, c, d, x, s, t)
{
return cmn((b & d) | (c & (~d)), a, b, x, s, t)
}
function hh(a, b, c, d, x, s, t)
{
return cmn(b ^ c ^ d, a, b, x, s, t)
}
function ii(a, b, c, d, x, s, t)
{
return cmn(c ^ (b | (~d)), a, b, x, s, t)
}
}
/*
* Calculate the HMAC-MD5, of a key and some data
*/
function core_hmac_md5(key, data)
{
var bkey = str2binl(key)
if(bkey.length > 16) bkey = core_md5(bkey, key.length * chrsz)
var ipad = Array(16), opad = Array(16)
for(var i = 0; i < 16; i++)
{
ipad[i] = bkey[i] ^ 0x36363636
opad[i] = bkey[i] ^ 0x5C5C5C5C
}
var hash = core_md5(ipad.concat(str2binl(data)), 512 + data.length * chrsz)
return core_md5(opad.concat(hash), 512 + 128)
}
/*
* Add integers, wrapping at 2^32. This uses 16-bit operations internally
* to work around bugs in some JS interpreters.
*/
function safe_add(x, y)
{
var lsw = (x & 0xFFFF) + (y & 0xFFFF)
var msw = (x >> 16) + (y >> 16) + (lsw >> 16)
return (msw << 16) | (lsw & 0xFFFF)
}
/*
* Bitwise rotate a 32-bit number to the left.
*/
function rol(num, cnt)
{
return (num << cnt) | (num >>> (32 - cnt))
}
/*
* Convert a string to an array of little-endian words
* If chrsz is ASCII, characters >255 have their hi-byte silently ignored.
*/
function str2binl(str)
{
var bin = Array()
var mask = (1 << chrsz) - 1
for(var i = 0; i < str.length * chrsz; i += chrsz)
bin[i>>5] |= (str.charCodeAt(i / chrsz) & mask) << (i%32)
return bin
}
/*
* Convert an array of little-endian words to a hex string.
*/
function binl2hex(binarray)
{
var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef"
var str = ""
for(var i = 0; i < binarray.length * 4; i++)
{
str += hex_tab.charAt((binarray[i>>2] >> ((i%4)*8+4)) & 0xF) +
hex_tab.charAt((binarray[i>>2] >> ((i%4)*8 )) & 0xF)
}
return str
}
/*
* Convert an array of little-endian words to a base-64 string
*/
function binl2b64(binarray)
{
var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/"
var str = ""
for(var i = 0; i < binarray.length * 4; i += 3)
{
var triplet = (((binarray[i >> 2] >> 8 * ( i %4)) & 0xFF) << 16)
| (((binarray[i+1 >> 2] >> 8 * ((i+1)%4)) & 0xFF) << 8 )
| ((binarray[i+2 >> 2] >> 8 * ((i+2)%4)) & 0xFF)
for(var j = 0; j < 4; j++)
{
if(i * 8 + j * 6 > binarray.length * 32) str += b64pad
else str += tab.charAt((triplet >> 6*(3-j)) & 0x3F)
}
}
return str;
}
