sha1.js

/*

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

 * in FIPS PUB 180-1

 * Version 2.1a Copyright Paul Johnston 2000 - 2002.

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

 * Modifications by Matthew Wild to export functions for CommonJS

 * 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   */

var chrsz   = 8;  /* bits per input character. 8 - ASCII; 16 - Unicode      */

/*

 * These are the functions you'll usually want to call

 * They take string arguments and return either hex or base-64 encoded strings

 */

exports.hex = function (s){return binb2hex(core_sha1(str2binb(s),s.length * chrsz));}

exports.b64 = function (s){return binb2b64(core_sha1(str2binb(s),s.length * chrsz));}

exports.str = function (s){return binb2str(core_sha1(str2binb(s),s.length * chrsz));}

exports.hex_hmac = function (key, data){ return binb2hex(core_hmac_sha1(key, data));}

exports.b64_hmac = function (key, data){ return binb2b64(core_hmac_sha1(key, data));}

exports.str_hmac = function (key, data){ return binb2str(core_hmac_sha1(key, data));}

/*

 * Perform a simple self-test to see if the VM is working

 */

function sha1_vm_test()

{

  return hex_sha1("abc") == "a9993e364706816aba3e25717850c26c9cd0d89d";

}

/*

 * Calculate the SHA-1 of an array of big-endian words, and a bit length

 */

function core_sha1(x, len)

{

  /* append padding */

  x[len >> 5] |= 0x80 << (24 - len % 32);

  x[((len + 64 >> 9) << 4) + 15] = len;

  var w = new Array(80);

  var a =  1732584193;

  var b = -271733879;

  var c = -1732584194;

  var d =  271733878;

  var e = -1009589776;

  var i, j, t, olda, oldb, oldc, oldd, olde;

  for (i = 0; i < x.length; i += 16)

  {

    olda = a;

    oldb = b;

    oldc = c;

    oldd = d;

    olde = e;

    for (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 = safe_add(safe_add(rol(a, 5), sha1_ft(j, b, c, d)),

                       safe_add(safe_add(e, w[j]), sha1_kt(j)));

      e = d;

      d = c;

      c = 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 [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;

}

/*

 * Calculate the HMAC-SHA1 of a key and some data

 */

function core_hmac_sha1(key, data)

{

  var bkey = str2binb(key);

  if (bkey.length > 16) { bkey = core_sha1(bkey, key.length * chrsz); }

  var ipad = new Array(16), opad = new Array(16);

  for (var i = 0; i < 16; i++)

  {

    ipad[i] = bkey[i] ^ 0x36363636;

    opad[i] = bkey[i] ^ 0x5C5C5C5C;

  }

  var hash = core_sha1(ipad.concat(str2binb(data)), 512 + data.length * chrsz);

  return core_sha1(opad.concat(hash), 512 + 160);

}

/*

 * 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));

}

/*

 * Convert an 8-bit or 16-bit string to an array of big-endian words

 * In 8-bit function, characters >255 have their hi-byte silently ignored.

 */

function str2binb(str)

{

  var bin = [];

  var mask = (1 << chrsz) - 1;

  for (var i = 0; i < str.length * chrsz; i += chrsz)

  {

    bin[i>>5] |= (str.charCodeAt(i / chrsz) & mask) << (32 - chrsz - i%32);

  }

  return bin;

}

/*

 * Convert an array of big-endian words to a string

 */

function binb2str(bin)

{

  var str = "";

  var mask = (1 << chrsz) - 1;

  for (var i = 0; i < bin.length * 32; i += chrsz)

  {

    str += String.fromCharCode((bin[i>>5] >>> (32 - chrsz - i%32)) & mask);

  }

  return str;

}

/*

 * Convert an array of big-endian words to a hex string.

 */

function binb2hex(binarray)

{

  var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";

  var str = "";

  for (var i = 0; i < binarray.length * 4; i++)

  {

    str += hex_tab.charAt((binarray[i>>2] >> ((3 - i%4)*8+4)) & 0xF) +

           hex_tab.charAt((binarray[i>>2] >> ((3 - i%4)*8  )) & 0xF);

  }

  return str;

}

/*

 * Convert an array of big-endian words to a base-64 string

 */

function binb2b64(binarray)

{

  var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

  var str = "";

  var triplet, j;

  for (var i = 0; i < binarray.length * 4; i += 3)

  {

    triplet = (((binarray[i   >> 2] >> 8 * (3 -  i   %4)) & 0xFF) << 16) |

              (((binarray[i+1 >> 2] >> 8 * (3 - (i+1)%4)) & 0xFF) << 8 ) |

               ((binarray[i+2 >> 2] >> 8 * (3 - (i+2)%4)) & 0xFF);

    for (j = 0; j < 4; j++)

    {

      if (i * 8 + j * 6 > binarray.length * 32) { str += b64pad; }

      else { str += tab.charAt((triplet >> 6*(3-j)) & 0x3F); }

    }

  }

  return str;

}