var hex_chr = "0123456789abcdef";

function hex(num)
{
  var str = "";
  for(var j = 7; j >= 0; j--)
    str += hex_chr.charAt((num >> (j * 4)) & 0x0F);
  return str;
}

function str2blks_SHA1(str)
{
  var nblk = ((str.length + 8) >> 6) + 1;
  var blks = new Array(nblk * 16);
  for(var i = 0; i < nblk * 16; i++) blks[i] = 0;
  for(i = 0; i < str.length; i++)
    blks[i >> 2] |= str.charCodeAt(i) << (24 - (i % 4) * 8);
  blks[i >> 2] |= 0x80 << (24 - (i % 4) * 8);
  blks[nblk * 16 - 1] = str.length * 8;
  return blks;
}

function add(x, y)
{
  var lsw = (x & 0xFFFF) + (y & 0xFFFF);
  var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
  return (msw << 16) | (lsw & 0xFFFF);
}

function rol(num, cnt)
{
  return (num << cnt) | (num >>> (32 - cnt));
}

function ft(t, b, c, d)
{
  if(t < 20) return (b & c) | ((~b) & d);
  if(t < 40) return b ^ c ^ d;
  if(t < 60) return (b & c) | (b & d) | (c & d);
  return b ^ c ^ d;
}

function kt(t)
{
  return (t < 20) ?  1518500249 : (t < 40) ?  1859775393 :
         (t < 60) ? -1894007588 : -899497514;
}

function calcSHA1(str)
{
  var x = str2blks_SHA1(str);
  var w = new Array(80);

  var a =  1732584193;
  var b = -271733879;
  var c = -1732584194;
  var d =  271733878;
  var e = -1009589776;

  for(var i = 0; i < x.length; i += 16)
  {
    var olda = a;
    var oldb = b;
    var oldc = c;
    var oldd = d;
    var olde = e;

    for(var j = 0; j < 80; j++)
    {
      if(j < 16) w[j] = x[i + j];
      else w[j] = rol(w[j-3] ^ w[j-8] ^ w[j-14] ^ w[j-16], 1);
      t = add(add(rol(a, 5), ft(j, b, c, d)), add(add(e, w[j]), kt(j)));
      e = d;
      d = c;
      c = rol(b, 30);
      b = a;
      a = t;
    }

    a = add(a, olda);
    b = add(b, oldb);
    c = add(c, oldc);
    d = add(d, oldd);
    e = add(e, olde);
  }
  return hex(a) + hex(b) + hex(c) + hex(d) + hex(e);
}

function CalcXor(First, Second) // Takes in 2 hex strings and XOR's them
{
    var Result = "";
    var TempResult = '';
    for(var i=0; i<First.length; i++)
    {
        Result += (parseInt(First.charAt(i), 16) ^ parseInt(Second.charAt(i), 16)).toString(16);
    }
    return Result;
}