sha1.js

/*
 * A JavaScript implementation of the Secure Hash Algorithm, SHA-1, as defined
 * in FIPS 180-1
 * Version 2.2 Copyright Paul Johnston 2000 - 2009.
 * Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
 * Distributed under the BSD License
 * See http://pajhome.org.uk/crypt/md5 for details.
 *
 * Modified slightly by Daniel Lucraft (2010)
 */

Sha1 = {
  /*
  * Configurable variables. You may need to tweak these to be compatible with
   * the server-side, but the defaults work in most cases.
   */
  hexcase: 0,  /* hex output format. 0 - lowercase; 1 - uppercase        */
  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
   */
  hex_sha1: function(s)    { return Sha1.rstr2hex(Sha1.rstr_sha1(Sha1.str2rstr_utf8(s))); },
  b64_sha1: function(s)    { return Sha1.rstr2b64(Sha1.rstr_sha1(Sha1.str2rstr_utf8(s))); },
  any_sha1: function(s, e) { return Sha1.rstr2any(Sha1.rstr_sha1(Sha1.str2rstr_utf8(s)), e); },
  hex_hmac_sha1: function(k, d)
    { return Sha1.rstr2hex(Sha1.rstr_hmac_sha1(Sha1.str2rstr_utf8(k), Sha1.str2rstr_utf8(d))); },
  b64_hmac_sha1: function(k, d)
    { return Sha1.rstr2b64(Sha1.rstr_hmac_sha1(Sha1.str2rstr_utf8(k), Sha1.str2rstr_utf8(d))); },
  any_hmac_sha1: function(k, d, e)
    { return Sha1.rstr2any(Sha1.rstr_hmac_sha1(Sha1.str2rstr_utf8(k), Sha1.str2rstr_utf8(d)), e); },
  
  /*
   * Perform a simple self-test to see if the VM is working
   */
  sha1_vm_test: function()
  {
    return Sha1.hex_sha1("abc").toLowerCase() == "a9993e364706816aba3e25717850c26c9cd0d89d";
  },
  
  /*
   * Calculate the SHA1 of a raw string
   */
  rstr_sha1: function(s)
  {
    return Sha1.binb2rstr(Sha1.binb_sha1(Sha1.rstr2binb(s), s.length * 8));
  },
  
  /*
   * Calculate the HMAC-SHA1 of a key and some data (raw strings)
   */
  rstr_hmac_sha1: function(key, data)
  {
    var bkey = Sha1.rstr2binb(key);
    if(bkey.length > 16) bkey = Sha1.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 = Sha1.binb_sha1(ipad.concat(Sha1.rstr2binb(data)), 512 + data.length * 8);
    return Sha1.binb2rstr(Sha1.binb_sha1(opad.concat(hash), 512 + 160));
  },
  
  /*
   * Convert a raw string to a hex string
   */
  rstr2hex: function(input)
  {
    try { Sha1.hexcase } catch(e) { Sha1.hexcase=0; }
    var hex_tab = Sha1.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
   */
  rstr2b64: function(input)
  {
    try { Sha1.b64pad } catch(e) { Sha1.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
   */
  rstr2any: function(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.
   */
  str2rstr_utf8: function(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
   */
  str2rstr_utf16le: function(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;
  },
  
  str2rstr_utf16be: function(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.
   */
  rstr2binb: function(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
   */
  binb2rstr: function(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
   */
  binb_sha1: function(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;
    
    var bit_rol = Sha1.bit_rol
    var safe_add = Sha1.safe_add
    var sha1_ft = Sha1.sha1_ft
    var sha1_kt = Sha1.sha1_kt
    
    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
   */
  sha1_ft: function(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
   */
  sha1_kt: function(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.
   */
  safe_add: function(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.
   */
  bit_rol: function(num, cnt)
  {
    return (num << cnt) | (num >>> (32 - cnt));
  }
}