• 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 */

/*

• 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_sha1(s) { return rstr2hex(rstr_sha1(str2rstr_utf8(s))); }
  function b64_sha1(s) { return rstr2b64(rstr_sha1(str2rstr_utf8(s))); }
  function any_sha1(s,e) { return rstr2any(rstr_sha1(str2rstr_utf8(s)),e); }
  function hex_hmac_sha1(k,d)
  { return rstr2hex(rstr_hmac_sha1(str2rstr_utf8(k),str2rstr_utf8(d))); }
  function b64_hmac_sha1(k,d)
  { return rstr2b64(rstr_hmac_sha1(str2rstr_utf8(k),str2rstr_utf8(d))); }
  function any_hmac_sha1(k,d,e)
  { return rstr2any(rstr_hmac_sha1(str2rstr_utf8(k),str2rstr_utf8(d)),e); }

/*

• Perform a simple self-test to see if the VM is working
  */
  function sha1_vm_test()
  {
  return hex_sha1("abc").toLowerCase() == "a9993e364706816aba3e25717850c26c9cd0d89d";
  }

/*

• Calculate the SHA1 of a raw string
  /
  function rstr_sha1(s)
  {
  return binb2rstr(binb_sha1(rstr2binb(s),s.length 8));
  }

/*

• Calculate the HMAC-SHA1 of a key and some data (raw strings)
  /
  function rstr_hmac_sha1(key,data)
  {
  var bkey = rstr2binb(key);
  if(bkey.length > 16) bkey = binb_sha1(bkey,key.length 8);

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 = binb_sha1(ipad.concat(rstr2binb(data)),512 + data.length * 8);
return binb2rstr(binb_sha1(opad.concat(hash),512 + 160));
}

/*

• Convert a raw string to a hex string
  */
  function rstr2hex(input)
  {
  try { hexcase } catch(e) { hexcase=0; }
  var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
  var output = "";
  var x;
  for(var i = 0; i < input.length; i++)
  {
  x = input.charCodeAt(i);
  output += hex_tab.charAt((x >>> 4) & 0x0F)
  • hex_tab.charAt( x & 0x0F);
    }
    return output;
    }

/*

• Convert a raw string to a base-64 string
  /
  function rstr2b64(input)
  {
  try { b64pad } catch(e) { b64pad=''; }
  var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  var output = "";
  var len = input.length;
  for(var i = 0; i < len; i += 3)
  {
  var triplet = (input.charCodeAt(i) << 16)
  | (i + 1 < len ? input.charCodeAt(i+1) << 8 : 0)
  | (i + 2 < len ? input.charCodeAt(i+2) : 0);
  for(var j = 0; j < 4; j++)
  {
  if(i 8 + j 6 > input.length 8) output += b64pad;
  else output += tab.charAt((triplet >>> 6*(3-j)) & 0x3F);
  }
  }
  return output;
  }

/*

• Convert a raw string to an arbitrary string encoding
  */
  function rstr2any(input,encoding)
  {
  var divisor = encoding.length;
  var remainders = Array();
  var i,q,x,quotient;

/ Convert to an array of 16-bit big-endian values,forming the dividend /
var dividend = Array(Math.ceil(input.length / 2));
for(i = 0; i < dividend.length; i++)
{
dividend[i] = (input.charCodeAt(i 2) << 8) | input.charCodeAt(i 2 + 1);
}

/*

• Repeatedly perform a long division. The binary array forms the dividend,* the length of the encoding is the divisor. Once computed,the quotient
• forms the dividend for the next step. We stop when the dividend is zero.
• All remainders are stored for later use.
  /
  while(dividend.length > 0)
  {
  quotient = Array();
  x = 0;
  for(i = 0; i < dividend.length; i++)
  {
  x = (x << 16) + dividend[i];
  q = Math.floor(x / divisor);
  x -= q divisor;
  if(quotient.length > 0 || q > 0)
  quotient[quotient.length] = q;
  }
  remainders[remainders.length] = x;
  dividend = quotient;
  }

/ Convert the remainders to the output string /
var output = "";
for(i = remainders.length - 1; i >= 0; i--)
output += encoding.charAt(remainders[i]);

/ Append leading zero equivalents /
var full_length = Math.ceil(input.length * 8 /
(Math.log(encoding.length) / Math.log(2)))
for(i = output.length; i < full_length; i++)
output = encoding[0] + output;

return output;
}

/*

• Encode a string as utf-8.
• For efficiency,this assumes the input is valid utf-16.
  */
  function str2rstr_utf8(input)
  {
  var output = "";
  var i = -1;
  var x,y;

while(++i < input.length)
{
/ Decode utf-16 surrogate pairs /
x = input.charCodeAt(i);
y = i + 1 < input.length ? input.charCodeAt(i + 1) : 0;
if(0xD800 <= x && x <= 0xDBFF && 0xDC00 <= y && y <= 0xDFFF)
{
x = 0x10000 + ((x & 0x03FF) << 10) + (y & 0x03FF);
i++;
}

/ Encode output as utf-8 /
if(x <= 0x7F)
output += String.fromCharCode(x);
else if(x <= 0x7FF)
output += String.fromCharCode(0xC0 | ((x >>> 6 ) & 0x1F),0x80 | ( x & 0x3F));
else if(x <= 0xFFFF)
output += String.fromCharCode(0xE0 | ((x >>> 12) & 0x0F),0x80 | ((x >>> 6 ) & 0x3F),0x80 | ( x & 0x3F));
else if(x <= 0x1FFFFF)
output += String.fromCharCode(0xF0 | ((x >>> 18) & 0x07),0x80 | ((x >>> 12) & 0x3F),0x80 | ( x & 0x3F));
}
return output;
}

/*

• Encode a string as utf-16
  */
  function str2rstr_utf16le(input)
  {
  var output = "";
  for(var i = 0; i < input.length; i++)
  output += String.fromCharCode( input.charCodeAt(i) & 0xFF,(input.charCodeAt(i) >>> 8) & 0xFF);
  return output;
  }

function str2rstr_utf16be(input)
{
var output = "";
for(var i = 0; i < input.length; i++)
output += String.fromCharCode((input.charCodeAt(i) >>> 8) & 0xFF,input.charCodeAt(i) & 0xFF);
return output;
}

/*

• Convert a raw string to an array of big-endian words
• Characters >255 have their high-byte silently ignored.
  /
  function rstr2binb(input)
  {
  var output = Array(input.length >> 2);
  for(var i = 0; i < output.length; i++)
  output[i] = 0;
  for(var i = 0; i < input.length 8; i += 8)
  output[i>>5] |= (input.charCodeAt(i / 8) & 0xFF) << (24 - i % 32);
  return output;
  }

/*

• Convert an array of big-endian words to a string
  /
  function binb2rstr(input)
  {
  var output = "";
  for(var i = 0; i < input.length 32; i += 8)
  output += String.fromCharCode((input[i>>5] >>> (24 - i % 32)) & 0xFF);
  return output;
  }

/*

• Calculate the SHA-1 of an array of big-endian words,and a bit length
  /
  function binb_sha1(x,len)
  {
  / append padding */
  x[len >> 5] |= 0x80 << (24 - len % 32);
  x[((len + 64 >> 9) << 4) + 15] = len;

var w = 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] = bit_rol(w[j-3] ^ w[j-8] ^ w[j-14] ^ w[j-16],1);
var t = safe_add(safe_add(bit_rol(a,5),sha1_ft(j,b,c,d)),safe_add(safe_add(e,w[j]),sha1_kt(j)));
e = d;
d = c;
c = bit_rol(b,30);
b = a;
a = t;
}

a = safe_add(a,olda);
b = safe_add(b,oldb);
c = safe_add(c,oldc);
d = safe_add(d,oldd);
e = safe_add(e,olde);
}
return Array(a,e);

}

/*

• Perform the appropriate triplet combination function for the current
• iteration
  */
  function sha1_ft(t,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;
  }

/*

• Determine the appropriate additive constant for the current iteration
  */
  function sha1_kt(t)
  {
  return (t < 20) ? 1518500249 : (t < 40) ? 1859775393 :
  (t < 60) ? -1894007588 : -899497514;
  }

/*

• 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 bit_rol(num,cnt)
  {
  return (num << cnt) | (num >>> (32 - cnt));
  }