SHA1.js

/**
 * Created by andy on 14-12-25.
 */
/**
 *
 *  Secure Hash Algorithm (SHA1)
 *  http://www.webtoolkit.info/
 *
 **/

function SHA1(msg) {

  function rotate_left(n, s) {
    var t4 = (n << s) | (n >>> (32 - s));
    return t4;
  };

  function lsb_hex(val) {
    var str = "";
    var i;
    var vh;
    var vl;

    for (i = 0; i <= 6; i += 2) {
      vh = (val >>> (i * 4 + 4)) & 0x0f;
      vl = (val >>> (i * 4)) & 0x0f;
      str += vh.toString(16) + vl.toString(16);
    }
    return str;
  };

  function cvt_hex(val) {
    var str = "";
    var i;
    var v;

    for (i = 7; i >= 0; i--) {
      v = (val >>> (i * 4)) & 0x0f;
      str += v.toString(16);
    }
    return str;
  };


  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;
  };

  var blockstart;
  var i, j;
  var W = new Array(80);
  var H0 = 0x67452301;
  var H1 = 0xEFCDAB89;
  var H2 = 0x98BADCFE;
  var H3 = 0x10325476;
  var H4 = 0xC3D2E1F0;
  var A, B, C, D, E;
  var temp;

  msg = Utf8Encode(msg);

  var msg_len = msg.length;

  var word_array = new Array();
  for (i = 0; i < msg_len - 3; i += 4) {
    j = msg.charCodeAt(i) << 24 | msg.charCodeAt(i + 1) << 16 |
    msg.charCodeAt(i + 2) << 8 | msg.charCodeAt(i + 3);
    word_array.push(j);
  }

  switch (msg_len % 4) {
    case 0:
      i = 0x080000000;
      break;
    case 1:
      i = msg.charCodeAt(msg_len - 1) << 24 | 0x0800000;
      break;

    case 2:
      i = msg.charCodeAt(msg_len - 2) << 24 | msg.charCodeAt(msg_len - 1) << 16 | 0x08000;
      break;

    case 3:
      i = msg.charCodeAt(msg_len - 3) << 24 | msg.charCodeAt(msg_len - 2) << 16 | msg.charCodeAt(msg_len - 1) << 8 | 0x80;
      break;
  }

  word_array.push(i);

  while ((word_array.length % 16) != 14) word_array.push(0);

  word_array.push(msg_len >>> 29);
  word_array.push((msg_len << 3) & 0x0ffffffff);


  for (blockstart = 0; blockstart < word_array.length; blockstart += 16) {

    for (i = 0; i < 16; i++) W[i] = word_array[blockstart + i];
    for (i = 16; i <= 79; i++) W[i] = rotate_left(W[i - 3] ^ W[i - 8] ^ W[i - 14] ^ W[i - 16], 1);

    A = H0;
    B = H1;
    C = H2;
    D = H3;
    E = H4;

    for (i = 0; i <= 19; i++) {
      temp = (rotate_left(A, 5) + ((B & C) | (~B & D)) + E + W[i] + 0x5A827999) & 0x0ffffffff;
      E = D;
      D = C;
      C = rotate_left(B, 30);
      B = A;
      A = temp;
    }

    for (i = 20; i <= 39; i++) {
      temp = (rotate_left(A, 5) + (B ^ C ^ D) + E + W[i] + 0x6ED9EBA1) & 0x0ffffffff;
      E = D;
      D = C;
      C = rotate_left(B, 30);
      B = A;
      A = temp;
    }

    for (i = 40; i <= 59; i++) {
      temp = (rotate_left(A, 5) + ((B & C) | (B & D) | (C & D)) + E + W[i] + 0x8F1BBCDC) & 0x0ffffffff;
      E = D;
      D = C;
      C = rotate_left(B, 30);
      B = A;
      A = temp;
    }

    for (i = 60; i <= 79; i++) {
      temp = (rotate_left(A, 5) + (B ^ C ^ D) + E + W[i] + 0xCA62C1D6) & 0x0ffffffff;
      E = D;
      D = C;
      C = rotate_left(B, 30);
      B = A;
      A = temp;
    }

    H0 = (H0 + A) & 0x0ffffffff;
    H1 = (H1 + B) & 0x0ffffffff;
    H2 = (H2 + C) & 0x0ffffffff;
    H3 = (H3 + D) & 0x0ffffffff;
    H4 = (H4 + E) & 0x0ffffffff;

  }

  var temp = cvt_hex(H0) + cvt_hex(H1) + cvt_hex(H2) + cvt_hex(H3) + cvt_hex(H4);

  return temp.toLowerCase();

}