/* 
 * A JavaScript implementation of the Secure Hash Algorithm,  SHA-1,  as defined 
 * in FIPS PUB 180-1 
 * Version 2.1 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 hmacsha1(key,  data){ return binb2hex(core_hmac_sha1(key,  data));} 
function hex_sha1(s){return binb2hex(core_sha1(str2binb(s), s.length * chrsz));} 
function b64_sha1(s){return binb2b64(core_sha1(str2binb(s), s.length * chrsz));} 
function str_sha1(s){return binb2str(core_sha1(str2binb(s), s.length * chrsz));} 
function hex_hmac_sha1(key,  data){ return binb2hex(core_hmac_sha1(key,  data));} 
function b64_hmac_sha1(key,  data){ return binb2b64(core_hmac_sha1(key,  data));} 
function str_hmac_sha1(key,  data){ return binb2str(core_hmac_sha1(key,  data));} 

/* 
 * 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 = 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] = rol(w[j-3] ^ w[j-8] ^ w[j-14] ^ w[j-16],  1); 
      var 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 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; 
}   

/* 
 * 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 = Array(16),  opad = 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 = Array(); 
  var mask = (1 << chrsz) - 1; 
  for(var i = 0; i < str.length * chrsz; i += chrsz) 
    bin[i>>5] |= (str.charCodeAt(i / chrsz) & mask) << (24 - 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] >>> (24 - 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 = ""; 
  for(var 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); 
    for(var 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; 
}