（转载）常用JS加密编码算法 五:SHA1算法

（转载）http://neil-yang.iteye.com/blog/703470

/*
 * 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
 * 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
 */
function hex_sha1s){return binb2hexcore_sha1str2binbs),s.length * chrsz));}
function b64_sha1s){return binb2b64core_sha1str2binbs),s.length * chrsz));}
function str_sha1s){return binb2strcore_sha1str2binbs),s.length * chrsz));}
function hex_hmac_sha1key, data){ return binb2hexcore_hmac_sha1key, data));}
function b64_hmac_sha1key, data){ return binb2b64core_hmac_sha1key, data));}
function str_hmac_sha1key, data){ return binb2strcore_hmac_sha1key, 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_sha1x, len)
{
  /* append padding */
  x[len >> 5] |= 0x80 << 24 - len % 32);
  x[len + 64 >> 9) << 4) + 15] = len;

  var w = Array80);
  var a =  1732584193;
  var b = -271733879;
  var c = -1732584194;
  var d =  271733878;
  var e = -1009589776;

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

    forvar j = 0; j < 80; j++)
    {
      ifj < 16) w[j] = x[i + j];
      else w[j] = rolw[j-3] ^ w[j-8] ^ w[j-14] ^ w[j-16], 1);
      var t = safe_addsafe_addrola, 5), sha1_ftj, b, c, d)),
                       safe_addsafe_adde, w[j]), sha1_ktj)));
      e = d;
      d = c;
      c = rolb, 30);
      b = a;
      a = t;
    }

    a = safe_adda, olda);
    b = safe_addb, oldb);
    c = safe_addc, oldc);
    d = safe_addd, oldd);
    e = safe_adde, olde);
  }
  return Arraya, b, c, d, e);

}

/*
 * Perform the appropriate triplet combination function for the current
 * iteration
 */
function sha1_ftt, b, c, d)
{
  ift < 20) return b & c) | ~b) & d);
  ift < 40) return b ^ c ^ d;
  ift < 60) return b & c) | b & d) | c & d);
  return b ^ c ^ d;
}

/*
 * Determine the appropriate additive constant for the current iteration
 */
function sha1_ktt)
{
  return t < 20) ?  1518500249 : t < 40) ?  1859775393 :
         t < 60) ? -1894007588 : -899497514;
}

/*
 * Calculate the HMAC-SHA1 of a key and some data
 */
function core_hmac_sha1key, data)
{
  var bkey = str2binbkey);
  ifbkey.length > 16) bkey = core_sha1bkey, key.length * chrsz);

  var ipad = Array16), opad = Array16);
  forvar i = 0; i < 16; i++)
  {
    ipad[i] = bkey[i] ^ 0x36363636;
    opad[i] = bkey[i] ^ 0x5C5C5C5C;
  }

  var hash = core_sha1ipad.concatstr2binbdata)), 512 + data.length * chrsz);
  return core_sha1opad.concathash), 512 + 160);
}

/*
 * Add integers, wrapping at 2^32. This uses 16-bit operations internally
 * to work around bugs in some JS interpreters.
 */
function safe_addx, 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 rolnum, 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 str2binbstr)
{
  var bin = Array);
  var mask = 1 << chrsz) - 1;
  forvar i = 0; i < str.length * chrsz; i += chrsz)
    bin[i>>5] |= str.charCodeAti / chrsz) & mask) << 32 - chrsz - i%32);
  return bin;
}

/*
 * Convert an array of big-endian words to a string
 */
function binb2strbin)
{
  var str = "";
  var mask = 1 << chrsz) - 1;
  forvar i = 0; i < bin.length * 32; i += chrsz)
    str += String.fromCharCodebin[i>>5] >>> 32 - chrsz - i%32)) & mask);
  return str;
}

/*
 * Convert an array of big-endian words to a hex string.
 */
function binb2hexbinarray)
{
  var hex_tab = hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
  var str = "";
  forvar i = 0; i < binarray.length * 4; i++)
  {
    str += hex_tab.charAtbinarray[i>>2] >> 3 - i%4)*8+4)) & 0xF) +
           hex_tab.charAtbinarray[i>>2] >> 3 - i%4)*8  )) & 0xF);
  }
  return str;
}

/*
 * Convert an array of big-endian words to a base-64 string
 */
function binb2b64binarray)
{
  var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  var str = "";
  forvar i = 0; i < binarray.length * 4; i += 3)
  {
    var 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);
    forvar j = 0; j < 4; j++)
    {
      ifi * 8 + j * 6 > binarray.length * 32) str += b64pad;
      else str += tab.charAttriplet >> 6*3-j)) & 0x3F);
    }
  }
  return str;
}