/*
 * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message
 * Digest Algorithm, as defined in RFC 1321.
 * Version 1.1 Copyright (C) Paul Johnston 1999 - 2002.
 * Code also contributed by Greg Holt
 * See http://pajhome.org.uk/site/legal.html for details.
 */

/*
 * 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));
}

/*
 * 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);
}

/*
 * Take a string and return the hex representation of its MD5.
 */
function coreMD5(x)
{
  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 [a, b, c, d]; // FIX
}

/*
 * Convert an array of little-endian words to a hex string.
 TBD
 */
function binl2hex(num)
{
  var hex_chr = "0123456789abcdef";
  var str = "";
  for(var j = 0; j <= 3; j++)
    str += hex_chr.charAt((num >> (j * 8 + 4)) & 0x0F) +
           hex_chr.charAt((num >> (j * 8)) & 0x0F);
  return str;
}

/*
 * Convert an array of little-endian words to a base64 encoded string.
 TBD
 */
function binl2b64(binarray)
{
  var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  var res = new String();
  for(var i=0; i<binarray.length; i++)
  {
    var triple = ((i > 0) ? ((binarray[i-1] << ( ( 3-(i%4) )*8) ) & 0x00FFFFFF) : 0x00) |
          ((binarray[i] >> (((i%4)+1)*8)) & 0x00FFFFFF);
    for (var j = 0; j < 4; j++) res += tab.charAt((triple >> ((3-j) * 6)) & 0x0000003F);
  }
  return res;
}

/*
 * Convert an 8-bit character string to a sequence of 16-word blocks, stored
 * as an array, and append appropriate padding for MD4/5 calculation.
 */
function str2binl(str)
{
/* Need error if high bits set */
  var nblk = ((str.length + 8) >> 6) + 1; // number of 16-word blocks
  var blks = new Array(nblk * 16);
  for(var i = 0; i < nblk * 16; i++) blks[i] = 0;
  for(var i = 0; i < str.length; i++)
    blks[i >> 2] |= str.charCodeAt(i) << ((i % 4) * 8);
  blks[i >> 2] |= 0x80 << ((i % 4) * 8);
  blks[nblk * 16 - 2] = str.length * 8;
  return blks;
}

/*
 * Convert a wide-character string to a sequence of 16-word blocks, stored as
 * an array, and append appropriate padding for MD4/5 calculation.
 TBD!
 */
function strw2binl(str)
{
  var nblk = ((str.length + 8) >> 6) + 1; // number of 16-word blocks
  var blks = new Array(nblk * 16);
  for(var i = 0; i < nblk * 16; i++) blks[i] = 0;
  for(var i = 0; i < str.length; i++)
    blks[i >> 2] |= str.charCodeAt(i) << ((i % 4) * 8);
  blks[i >> 2] |= 0x80 << ((i % 4) * 8);
  blks[nblk * 16 - 2] = str.length * 8;
  return blks;
}

/*
 * External interface
 */
function hexMD5 (str) { return binl2hex(coreMD5( str2binl(str))); }
function hexMD5w(str) { return binl2hex(coreMD5(strw2binl(str))); }
function b64MD5 (str) { return binl2b64(coreMD5( str2binl(str))); }
function b64MD5w(str) { return binl2b64(coreMD5(strw2binl(str))); }
/* Backward compatibility */
function calcMD5(str) { return binlhex(coreMD5( str2binl(str))); }