/*
 * A JavaScript implementation of the RSA Data Security, Inc. MD5 Message
 * Digest Algorithm, as defined in RFC 1321.
 * Copyright (C) Paul Johnston 1999 - 2000.
 * Updated by Greg Holt 2000 - 2001.
 * See http://pajhome.org.uk/site/legal.html for details.
 */

/*
 * Convert a 32-bit number to a hex string with ls-byte first
 */
var hex_chr = "0123456789abcdef";

// 
// somehow the expression (bitAND(b, c) | bitAND((~b), d)) didn't return coorect results on Mac
// for: 
// b&c = a8a20450, ((~b)&d) = 0101c88b, (bitAND(b, c) | bitAND((~b), d)) = a8a20450 <-- !!!
// looks like the OR is not executed at all.
//
// let's try to trick the P-code compiler into working with us... Prayer beads are GO!
// 
function bitOR(a, b)
{   
  var lsb = (a & 0x1) | (b & 0x1);
  var msb31 = (a >>> 1) | (b >>> 1);
  // trace("MD5 OR #1: a,b = "+rhex(a)+", "+rhex(b)+", (a|b) = "+rhex((a | b))+", return = "+rhex((msb31 << 1) | lsb));
  return (msb31 << 1) | lsb;
  // return (a | b);
}


//  
// will bitXOR be the only one working...?
// Nope. XOR fails too if values with bit31 set are XORed. 
//
// Note however that OR (and AND and XOR?!) works alright for the statement
//   (msb31 << 1) | lsb
// even if the result of the left-shift operation has bit 31 set.
// So there might be an extra condition here (Guessmode turned on):
// Mac Flash fails (OR, AND and XOR) if either one of the input operands has bit31 set
// *and* both operands have one or more bits both set to 1. In other words: when both
// input bit-patterns 'overlap'.
// Stuff to munch on for the MM guys, I guess...
//
function bitXOR(a, b)
{   
  var lsb = (a & 0x1) ^ (b & 0x1);
  var msb31 = (a >>> 1) ^ (b >>> 1);
  // trace("MD5 XOR #1: a,b = "+rhex(a)+", "+rhex(b)+", (a^b) = "+rhex((a ^ b))+", return = "+rhex((msb31 << 1) ^ lsb));
  return (msb31 << 1) | lsb;
  // return (a ^ b);
}
  

  
// 
// bitwise AND for 32-bit integers. This uses 31 + 1-bit operations internally
// to work around bug in some AS interpreters. (Mac Flash!)
// 
function bitAND(a, b)
{   
  var lsb = (a & 0x1) & (b & 0x1);
  var msb31 = (a >>> 1) & (b >>> 1);
  return (msb31 << 1) | lsb;
  // return (a & b);
}

// 
// Add integers, wrapping at 2^32. This uses 16-bit operations internally
// to work around bugs in some AS interpreters. (Mac Flash!)
// 
function addme(x, y) 
{
  var lsw = (x & 0xFFFF)+(y & 0xFFFF);
  var msw = (x >> 16)+(y >> 16)+(lsw >> 16);
  // trace("MD5 ADDME #1: x,y = "+rhex(x)+", "+rhex(y)+", msw, lsw = "+rhex(msw)+", "+rhex(lsw));
  return (msw << 16) | (lsw & 0xFFFF);
  // return (a + b);
}

function rhex(num)
{
  str = "";
  for(j = 0; j <= 3; j++)
  {
    str += hex_chr.charAt((num >> (j * 8 + 4)) & 0x0F) +
           hex_chr.charAt((num >> (j * 8)) & 0x0F);
  }
  return str;
}

/*
 * Convert a string to a sequence of 16-word blocks, stored as an array.
 * Append padding bits and the length, as described in the MD5 standard.
 */
function str2blks_MD5(str)
{
  nblk = ((str.length + 8) >> 6) + 1;  // 1 + (len + 8)/64
  blks = new Array(nblk * 16);
  for(i = 0; i < nblk * 16; i++) blks[i] = 0;

                                                                
/*
Input: 

'willi' without the quotes.

trace() Output on Intel (and MAC now?):

see TXT files: *.Output.txt

*/

  for(i = 0; i < str.length; i++)
  {
    blks[i >> 2] |= str.charCodeAt(i) << (((str.length * 8 + i) % 4) * 8);
    // trace("str2blks_MD5: chr["+i+"] = "+str.charCodeAt(i)+",shift:"+(((str.length * 8 + i) % 4)*8)+",shifted:"+rhex(blks[i >> 2]));
  }
  blks[i >> 2] |= 0x80 << (((str.length * 8 + i) % 4) * 8);
  // trace("str2blks_MD5: END - idx:"+i+" = "+0x80+",shift:"+(((str.length * 8 + i) % 4)*8)+",shifted:"+rhex(blks[i >> 2]));
  // blks[nblk * 16 - 2] = str.length * 8;
  var l = str.length * 8;
  blks[nblk * 16 - 2] = (l & 0xFF);
  blks[nblk * 16 - 2] |= ((l >>> 8) & 0xFF) << 8;
  blks[nblk * 16 - 2] |= ((l >>> 16) & 0xFF) << 16;
  blks[nblk * 16 - 2] |= ((l >>> 24) & 0xFF) << 24;

  // trace("str2blks_MD5: LEN - idx*4:"+(nblk * 16 - 2)+" = "+rhex(blks[nblk * 16 - 2]));
  return blks;
}

/*
 * Bitwise rotate a 32-bit number to the left
 */
function rol(num, cnt)
{
  return (num << cnt) | (num >>> (32 - cnt));
}

/*
 * These functions implement the basic operation for each round of the
 * algorithm.
 */
function cmn(q, a, b, x, s, t)
{
  // trace("MD5 CMN #1: q = "+rhex(q)+", (a + q + x + t) = "+rhex(a + q + x + t)+", rol() = "+rhex(rol((a + q + x + t), s))+", return = "+rhex(rol((a + q + x + t), s) + b)+", returnALT = "+rhex(addme(rol((addme(addme(a, q), addme(x, t))), s), b)));
  return addme(rol((addme(addme(a, q), addme(x, t))), s), b);
}
function ff(a, b, c, d, x, s, t)
{
  // trace("MD5 FF #1: a,b,c,d,x,s,t = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+","+rhex(x)+","+rhex(s)+","+rhex(t));
  // trace("MD5 FF #2: b&c = "+rhex(bitAND(b, c))+", ((~b)&d) = "+rhex(bitAND((~b), d))+", cmn("+rhex(bitOR(bitAND(b, c), bitAND((~b), d)))+",...)");
  return cmn(bitOR(bitAND(b, c), bitAND((~b), d)), a, b, x, s, t);
}
function gg(a, b, c, d, x, s, t)
{
  // trace("MD5 GG #1: a,b,c,d,x,s,t = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+","+rhex(x)+","+rhex(s)+","+rhex(t));
  // trace("MD5 GG #2: b&d = "+rhex(bitAND(b, d))+", (c&(~d)) = "+rhex(bitAND(c, (~d)))+", cmn("+rhex(bitOR(bitAND(b, d), bitAND(c, (~d))))+",...)");
  return cmn(bitOR(bitAND(b, d), bitAND(c, (~d))), a, b, x, s, t);
}
function hh(a, b, c, d, x, s, t)
{
  // trace("MD5 HH #1: a,b,c,d,x,s,t = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+","+rhex(x)+","+rhex(s)+","+rhex(t));
  // trace("MD5 HH #2: (b^c) = "+rhex(b ^ c)+", (b^c^d) = "+rhex(b ^ c ^d)+", cmn("+rhex(bitXOR(bitXOR(b, c), d))+",...)");
  return cmn(bitXOR(bitXOR(b, c), d), a, b, x, s, t);
}
function ii(a, b, c, d, x, s, t)
{
  // trace("MD5 II #1: a,b,c,d,x,s,t = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+","+rhex(x)+","+rhex(s)+","+rhex(t));
  // trace("MD5 II #2: (b|(~d)) = "+rhex(bitOR(b, (~d)))+", (c^(b|(~d)) = "+rhex(c ^ bitOR(b, (~d)))+", cmn("+rhex(bitXOR(c, bitOR(b, (~d))))+",...)");
  return cmn(bitXOR(c, bitOR(b, (~d))), a, b, x, s, t);
}

/*
 * Take a string and return the hex representation of its MD5.
 */
function calcMD5(str)
{
  x = str2blks_MD5(str);
  a =  1732584193;
  b = -271733879;
  c = -1732584194;
  d =  271733878;
  // trace("MD5INIT: a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d));
  var step;

  for(i = 0; i < x.length; i += 16)
  {
    olda = a;
    oldb = b;
    oldc = c;
    oldd = d;
    
    step = 0;
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d));
    a = ff(a, b, c, d, x[i+ 0], 7 , -680876936);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 0] = "+rhex(x[i+ 0]));
    d = ff(d, a, b, c, x[i+ 1], 12, -389564586);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 1] = "+rhex(x[i+ 1]));
    c = ff(c, d, a, b, x[i+ 2], 17,  606105819);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 2] = "+rhex(x[i+ 2]));
    b = ff(b, c, d, a, x[i+ 3], 22, -1044525330);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 3] = "+rhex(x[i+ 3]));
    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);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 4],x[i+ 5],x[i+ 6],x[i+ 7] = "+rhex(x[i+ 4])+","+rhex(x[i+ 5])+","+rhex(x[i+ 6])+","+rhex(x[i+ 7]));
    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);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 8],x[i+ 9],x[i+10],x[i+11] = "+rhex(x[i+ 8])+","+rhex(x[i+ 9])+","+rhex(x[i+10])+","+rhex(x[i+11]));
    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);    
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+12],x[i+13],x[i+14],x[i+15] = "+rhex(x[i+12])+","+rhex(x[i+13])+","+rhex(x[i+14])+","+rhex(x[i+15]));
    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);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 1],x[i+ 6],x[i+11],x[i+ 0] = "+rhex(x[i+ 1])+","+rhex(x[i+ 6])+","+rhex(x[i+11])+","+rhex(x[i+ 0]));
    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);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 5],x[i+10],x[i+15],x[i+ 4] = "+rhex(x[i+ 5])+","+rhex(x[i+10])+","+rhex(x[i+15])+","+rhex(x[i+ 4]));
    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);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 9],x[i+14],x[i+ 3],x[i+ 8] = "+rhex(x[i+ 9])+","+rhex(x[i+14])+","+rhex(x[i+ 3])+","+rhex(x[i+ 8]));
    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);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+13],x[i+ 2],x[i+ 7],x[i+12] = "+rhex(x[i+13])+","+rhex(x[i+ 2])+","+rhex(x[i+ 7])+","+rhex(x[i+12]));
    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);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 5],x[i+ 8],x[i+11],x[i+14] = "+rhex(x[i+ 5])+","+rhex(x[i+ 8])+","+rhex(x[i+11])+","+rhex(x[i+14]));
    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);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 1],x[i+ 4],x[i+ 7],x[i+10] = "+rhex(x[i+ 1])+","+rhex(x[i+ 4])+","+rhex(x[i+ 7])+","+rhex(x[i+10]));
    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);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+13],x[i+ 0],x[i+ 3],x[i+ 6] = "+rhex(x[i+13])+","+rhex(x[i+ 0])+","+rhex(x[i+ 3])+","+rhex(x[i+ 6]));
    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);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 9],x[i+12],x[i+15],x[i+ 2] = "+rhex(x[i+ 9])+","+rhex(x[i+12])+","+rhex(x[i+15])+","+rhex(x[i+ 2]));
    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);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 0],x[i+ 7],x[i+14],x[i+ 5] = "+rhex(x[i+ 0])+","+rhex(x[i+ 7])+","+rhex(x[i+14])+","+rhex(x[i+ 5]));
    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);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+12],x[i+ 3],x[i+10],x[i+ 1] = "+rhex(x[i+12])+","+rhex(x[i+ 3])+","+rhex(x[i+10])+","+rhex(x[i+ 1]));
    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);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 8],x[i+15],x[i+ 6],x[i+13] = "+rhex(x[i+ 8])+","+rhex(x[i+15])+","+rhex(x[i+ 6])+","+rhex(x[i+13]));
    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);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d)+",x[i+ 4],x[i+11],x[i+ 2],x[i+ 9] = "+rhex(x[i+ 4])+","+rhex(x[i+11])+","+rhex(x[i+ 2])+","+rhex(x[i+ 9]));

    a = addme(a, olda);
    b = addme(b, oldb);
    c = addme(c, oldc);
    d = addme(d, oldd);
    // trace("MD5LOOP: i = "+i+", step = "+(++step)+", a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d));
  }
  // trace("MD5FINISH: a,b,c,d = "+rhex(a)+","+rhex(b)+","+rhex(c)+","+rhex(d));
  return rhex(a) + rhex(b) + rhex(c) + rhex(d);
}