"use strict";

function myMain () {
  var dfp; 
  var MAX=100000; // # hashes to do and time
  var st = (new Date()).getTime();
  for (var i=1; i<=MAX; i++) {
    dfp = SHA256("this is just a test text message");
  }
  var et = (new Date()).getTime(); 
  alert(et-st + " msec");

  var doneStr = "done and done";
  alert(doneStr + ": " + SHA256(doneStr)); 
}

myMain();


function SHA256(s){
  /*
  **************************************************************
  **  Secure Hash Algorithm (SHA256)
  **  http://www.webtoolkit.info/
  **
  **  Original code by Angel Marin, Paul Johnston.
  **************************************************************
  */

  var chrsz   = 8;
  var hexcase = 0;
  s = Utf8Encode(s);
  return binb2hex(core_sha256(str2binb(s), s.length * chrsz));

  function safe_add (x, y) {
    var lsw = (x & 0xFFFF) + (y & 0xFFFF);
    var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
    return (msw << 16) | (lsw & 0xFFFF);
  }

  function S (X, n) { return ( X >>> n ) | (X << (32 - n)); }
  function R (X, n) { return ( X >>> n ); }
  function Ch(x, y, z) { return ((x & y) ^ ((~x) & z)); }
  function Maj(x, y, z) { return ((x & y) ^ (x & z) ^ (y & z)); }
  function Sigma0256(x) { return (S(x, 2) ^ S(x, 13) ^ S(x, 22)); }
  function Sigma1256(x) { return (S(x, 6) ^ S(x, 11) ^ S(x, 25)); }
  function Gamma0256(x) { return (S(x, 7) ^ S(x, 18) ^ R(x, 3)); }
  function Gamma1256(x) { return (S(x, 17) ^ S(x, 19) ^ R(x, 10)); }

  function core_sha256 (m, l) {
    var K = new Array( 
      0x428A2F98, 0x71374491, 0xB5C0FBCF, 0xE9B5DBA5, 
      0x3956C25B, 0x59F111F1, 0x923F82A4, 0xAB1C5ED5, 
      0xD807AA98, 0x12835B01, 0x243185BE, 0x550C7DC3, 
      0x72BE5D74, 0x80DEB1FE, 0x9BDC06A7, 0xC19BF174, 
      0xE49B69C1, 0xEFBE4786, 0xFC19DC6,  0x240CA1CC, 
      0x2DE92C6F, 0x4A7484AA, 0x5CB0A9DC, 0x76F988DA, 
      0x983E5152, 0xA831C66D, 0xB00327C8, 0xBF597FC7, 
      0xC6E00BF3, 0xD5A79147, 0x6CA6351,  0x14292967, 
      0x27B70A85, 0x2E1B2138, 0x4D2C6DFC, 0x53380D13, 
      0x650A7354, 0x766A0ABB, 0x81C2C92E, 0x92722C85, 
      0xA2BFE8A1, 0xA81A664B, 0xC24B8B70, 0xC76C51A3, 
      0xD192E819, 0xD6990624, 0xF40E3585, 0x106AA070, 
      0x19A4C116, 0x1E376C08, 0x2748774C, 0x34B0BCB5, 
      0x391C0CB3, 0x4ED8AA4A, 0x5B9CCA4F, 0x682E6FF3, 
      0x748F82EE, 0x78A5636F, 0x84C87814, 0x8CC70208, 
      0x90BEFFFA, 0xA4506CEB, 0xBEF9A3F7, 0xC67178F2
    );

    var HASH = new Array( 
      0x6A09E667, 0xBB67AE85, 0x3C6EF372, 0xA54FF53A, 
      0x510E527F, 0x9B05688C, 0x1F83D9AB, 0x5BE0CD19
    );
    var W = new Array(64);
    var a, b, c, d, e, f, g, h, i, j;
    var T1, T2;
    m[l >> 5] |= 0x80 << (24 - l % 32);
    m[((l + 64 >> 9) << 4) + 15] = l;

    for ( var i = 0; i<m.length; i+=16 ) {
      a = HASH[0]; b = HASH[1]; c = HASH[2]; d = HASH[3]; 
      e = HASH[4]; f = HASH[5]; g = HASH[6]; h = HASH[7];

      for ( var j = 0; j<64; j++) {
        if (j < 16) { W[j] = m[j + i]; }
        else { 
          W[j] = safe_add( safe_add( safe_add(Gamma1256(W[j - 2]), W[j - 7]), Gamma0256(W[j - 15])), W[j - 16]);
        };

        T1 = safe_add(safe_add(safe_add(safe_add(h, Sigma1256(e)), Ch(e, f, g)), K[j]), W[j]);
        T2 = safe_add(Sigma0256(a), Maj(a, b, c));

        h = g; g = f; f = e;  e = safe_add(d, T1);
        d = c; c = b; b = a;  a = safe_add(T1, T2);
      }

      HASH[0] = safe_add(a, HASH[0]);
      HASH[1] = safe_add(b, HASH[1]);
      HASH[2] = safe_add(c, HASH[2]);
      HASH[3] = safe_add(d, HASH[3]);
      HASH[4] = safe_add(e, HASH[4]);
      HASH[5] = safe_add(f, HASH[5]);
      HASH[6] = safe_add(g, HASH[6]);
      HASH[7] = safe_add(h, HASH[7]);
    }
    return HASH;
  }

  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;
  }

  function Utf8Encode(string) {
    string = string.replace(/\r\n/g,"\n");
    var utftext = "";
    for (var n = 0; n < string.length; n++) {
      var c = string.charCodeAt(n);
      if (c < 128) { utftext += String.fromCharCode(c); }
      else if((c > 127) && (c < 2048)) {
        utftext += String.fromCharCode((c >> 6) | 192);
        utftext += String.fromCharCode((c & 63) | 128);
      }
      else {
        utftext += String.fromCharCode((c >> 12) | 224);
        utftext += String.fromCharCode(((c >> 6) & 63) | 128);
        utftext += String.fromCharCode((c & 63) | 128);
      }
    }
    return utftext;
  }

  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;
  }
}

//alert(SHA256("now is the time"));