view/js/hashing.js

var Sha1 = {};

Sha1.hash = function(msg, utf8encode) {
  utf8encode =  (typeof utf8encode == 'undefined') ? true : utf8encode;

  if (utf8encode) msg = Utf8.encode(msg);

  var K = [0x5a827999, 0x6ed9eba1, 0x8f1bbcdc, 0xca62c1d6];

  msg += String.fromCharCode(0x80);

  var l = msg.length/4 + 2;
  var N = Math.ceil(l/16);
  var M = new Array(N);

  for (var i=0; i<N; i++) {
    M[i] = new Array(16);
    for (var j=0; j<16; j++) {
      M[i][j] = (msg.charCodeAt(i*64+j*4)<<24) | (msg.charCodeAt(i*64+j*4+1)<<16) |
        (msg.charCodeAt(i*64+j*4+2)<<8) | (msg.charCodeAt(i*64+j*4+3));
    }
  }
  
  M[N-1][14] = ((msg.length-1)*8) / Math.pow(2, 32); M[N-1][14] = Math.floor(M[N-1][14])
  M[N-1][15] = ((msg.length-1)*8) & 0xffffffff;

  var H0 = 0x67452301;
  var H1 = 0xefcdab89;
  var H2 = 0x98badcfe;
  var H3 = 0x10325476;
  var H4 = 0xc3d2e1f0;

  var W = new Array(80); var a, b, c, d, e;
  for (var i=0; i<N; i++) {

    for (var t=0;  t<16; t++) W[t] = M[i][t];
    for (var t=16; t<80; t++) W[t] = Sha1.ROTL(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16], 1);

    a = H0; b = H1; c = H2; d = H3; e = H4;

    for (var t=0; t<80; t++) {
      var s = Math.floor(t/20);
      var T = (Sha1.ROTL(a,5) + Sha1.f(s,b,c,d) + e + K[s] + W[t]) & 0xffffffff;
      e = d;
      d = c;
      c = Sha1.ROTL(b, 30);
      b = a;
      a = T;
    }

    H0 = (H0+a) & 0xffffffff;
    H1 = (H1+b) & 0xffffffff;
    H2 = (H2+c) & 0xffffffff;
    H3 = (H3+d) & 0xffffffff;
    H4 = (H4+e) & 0xffffffff;
  }

  return Sha1.toHexStr(H0) + Sha1.toHexStr(H1) +
    Sha1.toHexStr(H2) + Sha1.toHexStr(H3) + Sha1.toHexStr(H4);
}

Sha1.f = function(s, x, y, z)  {
  switch (s) {
  case 0: return (x & y) ^ (~x & z);           // Ch()
  case 1: return x ^ y ^ z;                    // Parity()
  case 2: return (x & y) ^ (x & z) ^ (y & z);  // Maj()
  case 3: return x ^ y ^ z;                    // Parity()
  }
}

Sha1.ROTL = function(x, n) {
  return (x<<n) | (x>>>(32-n));
}

Sha1.toHexStr = function(n) {
  var s="", v;
  for (var i=7; i>=0; i--) { v = (n>>>(i*4)) & 0xf; s += v.toString(16); }
  return s;
}


var Utf8 = {};

Utf8.encode = function(strUni) {
  
  var strUtf = strUni.replace(
      /[\u0080-\u07ff]/g,
      function(c) {
        var cc = c.charCodeAt(0);
        return String.fromCharCode(0xc0 | cc>>6, 0x80 | cc&0x3f); }
    );
  strUtf = strUtf.replace(
      /[\u0800-\uffff]/g,
      function(c) {
        var cc = c.charCodeAt(0);
        return String.fromCharCode(0xe0 | cc>>12, 0x80 | cc>>6&0x3F, 0x80 | cc&0x3f); }
    );
  return strUtf;
}

Utf8.decode = function(strUtf) {
 
  var strUni = strUtf.replace(
      /[\u00e0-\u00ef][\u0080-\u00bf][\u0080-\u00bf]/g,
      function(c) {
        var cc = ((c.charCodeAt(0)&0x0f)<<12) | ((c.charCodeAt(1)&0x3f)<<6) | ( c.charCodeAt(2)&0x3f);
        return String.fromCharCode(cc); }
    );
  strUni = strUni.replace(
      /[\u00c0-\u00df][\u0080-\u00bf]/g,
      function(c) {
        var cc = (c.charCodeAt(0)&0x1f)<<6 | c.charCodeAt(1)&0x3f;
        return String.fromCharCode(cc); }
    );
  return strUni;
}