/*

 * A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined

 * in FIPS 180-1

 * Version 2.2-alpha Copyright Paul Johnston 2000 - 2002.

 * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet

 * Distributed under the BSD License

 * See http://pajhome.org.uk/crypt/md5 for details.

 */



/*

 * 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") == "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)

{

  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)

{

  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 >>> 6 ) & 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 little-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, b, c, d, e);



}



/*

 * Perform the appropriate triplet combination function for the current

 * iteration

 */

function sha1_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;

}



/*

 * 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));

}