text: function sha1(str) {
    //  discuss at: http://phpjs.org/functions/sha1/
    // original by: Webtoolkit.info (http://www.webtoolkit.info/)
    // improved by: Michael White (http://getsprink.com)
    // improved by: Kevin van Zonneveld (http://kevin.vanzonneveld.net)
    //    input by: Brett Zamir (http://brett-zamir.me)
    //   example 1: sha1('Kevin van Zonneveld');
    //   returns 1: '54916d2e62f65b3afa6e192e6a601cdbe5cb5897'
  
    var rotate_left = function (n, s) {
      var t4 = (n << s) | (n >>> (32 - s));
      return t4;
    };
  
    /*var lsb_hex = function (val) {
     // Not in use; needed?
      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;
    };*/
  
    var cvt_hex = function (val) {
      var str = '';
      var i;
      var v;
  
      for (i = 7; i >= 0; i--) {
        v = (val >>> (i * 4)) & 0x0f;
        str += v.toString(16);
      }
      return str;
    };
  
    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;
  
    // utf8_encode
    str = unescape(encodeURIComponent(str));
    var str_len = str.length;
  
    var word_array = [];
    for (i = 0; i < str_len - 3; i += 4) {
      j = str.charCodeAt(i) << 24 | str.charCodeAt(i + 1) << 16 | str.charCodeAt(i + 2) << 8 | str.charCodeAt(i + 3);
      word_array.push(j);
    }
  
    switch (str_len % 4) {
    case 0:
      i = 0x080000000;
      break;
    case 1:
      i = str.charCodeAt(str_len - 1) << 24 | 0x0800000;
      break;
    case 2:
      i = str.charCodeAt(str_len - 2) << 24 | str.charCodeAt(str_len - 1) << 16 | 0x08000;
      break;
    case 3:
      i = str.charCodeAt(str_len - 3) << 24 | str.charCodeAt(str_len - 2) << 16 | str.charCodeAt(str_len - 1) <<
        8 | 0x80;
      break;
    }
  
    word_array.push(i);
  
    while ((word_array.length % 16) != 14) {
      word_array.push(0);
    }
  
    word_array.push(str_len >>> 29);
    word_array.push((str_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;
    }
  
    temp = cvt_hex(H0) + cvt_hex(H1) + cvt_hex(H2) + cvt_hex(H3) + cvt_hex(H4);
    return temp.toLowerCase();
  }
  