极湖

function md5(sText) {
  var MD5_T = [
    0x00000000, 0xd76aa478, 0xe8c7b756, 0x242070db,
    0xc1bdceee, 0xf57c0faf, 0x4787c62a, 0xa8304613,
    0xfd469501, 0x698098d8, 0x8b44f7af, 0xffff5bb1,
    0x895cd7be, 0x6b901122, 0xfd987193, 0xa679438e,
    0x49b40821, 0xf61e2562, 0xc040b340, 0x265e5a51,
    0xe9b6c7aa, 0xd62f105d, 0x02441453, 0xd8a1e681,
    0xe7d3fbc8, 0x21e1cde6, 0xc33707d6, 0xf4d50d87,
    0x455a14ed, 0xa9e3e905, 0xfcefa3f8, 0x676f02d9,
    0x8d2a4c8a, 0xfffa3942, 0x8771f681, 0x6d9d6122,
    0xfde5380c, 0xa4beea44, 0x4bdecfa9, 0xf6bb4b60,
    0xbebfbc70, 0x289b7ec6, 0xeaa127fa, 0xd4ef3085,
    0x04881d05, 0xd9d4d039, 0xe6db99e5, 0x1fa27cf8,
    0xc4ac5665, 0xf4292244, 0x432aff97, 0xab9423a7,
    0xfc93a039, 0x655b59c3, 0x8f0ccc92, 0xffeff47d,
    0x85845dd1, 0x6fa87e4f, 0xfe2ce6e0, 0xa3014314,
    0x4e0811a1, 0xf7537e82, 0xbd3af235, 0x2ad7d2bb,
    0xeb86d391
  ];

  var MD5_round1 = [
    [ 0, 7, 1], [ 1,12, 2],
    [ 2,17, 3], [ 3,22, 4],
    [ 4, 7, 5], [ 5,12, 6],
    [ 6,17, 7], [ 7,22, 8],
    [ 8, 7, 9], [ 9,12,10],
    [10,17,11], [11,22,12],
    [12, 7,13], [13,12,14],
    [14,17,15], [15,22,16]
  ];

  var MD5_round2 = [
    [ 1, 5,17], [ 6, 9,18],
    [11,14,19], [ 0,20,20],
    [ 5, 5,21], [10, 9,22],
    [15,14,23], [ 4,20,24],
    [ 9, 5,25], [14, 9,26],
    [ 3,14,27], [ 8,20,28],
    [13, 5,29], [ 2, 9,30],
    [ 7,14,31], [12,20,32]
  ];

  var MD5_round3 = [
    [ 5, 4,33], [ 8,11,34],
    [11,16,35], [14,23,36],
    [ 1, 4,37], [ 4,11,38],
    [ 7,16,39], [10,23,40],
    [13, 4,41], [ 0,11,42],
    [ 3,16,43], [ 6,23,44],
    [ 9, 4,45], [12,11,46],
    [15,16,47], [ 2,23,48]
  ];

  var MD5_round4 = [
    [ 0, 6,49], [ 7,10,50],
    [14,15,51], [ 5,21,52],
    [12, 6,53], [ 3,10,54],
    [10,15,55], [ 1,21,56],
    [ 8, 6,57], [15,10,58],
    [ 6,15,59], [13,21,60],
    [ 4, 6,61], [11,10,62],
    [ 2,15,63], [ 9,21,64]
  ];

  function MD5_F(x, y, z) { return (x & y) | (~x & z); }
  function MD5_G(x, y, z) { return (x & z) | (y & ~z); }
  function MD5_H(x, y, z) { return x ^ y ^ z; }
  function MD5_I(x, y, z) { return y ^ (x | ~z); }

  var MD5_round = [
    [MD5_F, MD5_round1],
    [MD5_G, MD5_round2],
    [MD5_H, MD5_round3],
    [MD5_I, MD5_round4]
  ];

  function MD5_pack(n32) {
    return String.fromCharCode(n32 & 0xff)
      + String.fromCharCode((n32 >>> 8) & 0xff)
      + String.fromCharCode((n32 >>> 16) & 0xff)
      + String.fromCharCode((n32 >>> 24) & 0xff);
  }

  function MD5_unpack(s4) {
    return  s4.charCodeAt(0)
      | (s4.charCodeAt(1) <<  8)
      | (s4.charCodeAt(2) << 16)
      | (s4.charCodeAt(3) << 24);
  }

  function MD5_number(n) {
    while (n < 0)
      n += 4294967296;
    while (n > 4294967295)
      n -= 4294967296;
    return n;
  }

  function MD5_apply_round(x, s, f, abcd, r) {
    var a, b, c, d;
    var kk, ss, ii;
    var t, u;

    a = abcd[0];
    b = abcd[1];
    c = abcd[2];
    d = abcd[3];
    kk = r[0];
    ss = r[1];
    ii = r[2];

    u = f(s[b], s[c], s[d]);
    t = s[a] + u + x[kk] + MD5_T[ii];
    t = MD5_number(t);
    t = ((t<<ss) | (t>>>(32-ss)));
    t += s[b];
    s[a] = MD5_number(t);
  }

  function MD5_hash(data) {
    var abcd, x, state, s;
    var len, index, padLen, f, r;
    var i, j, k;
    var tmp;

    state = [0x67452301, 0xefcdab89, 0x98badcfe, 0x10325476];
    len = data.length;
    index = len & 0x3f;
    padLen = (index < 56) ? (56 - index) : (120 - index);
    if(padLen > 0) {
      data += '\x80';
      for(i = 0; i < padLen - 1; i++)
        data += '\x00';
    }
    data += MD5_pack(len * 8);
    data += MD5_pack(0);
    len += padLen + 8;
    abcd = [0, 1, 2, 3];
    x = [16];
    s = [4];

    for(k = 0; k < len; k += 64) {
      for(i = 0, j = k; i < 16; i++, j += 4) {
        x[i] = data.charCodeAt(j)
          | (data.charCodeAt(j + 1) <<  8)
          | (data.charCodeAt(j + 2) << 16)
          | (data.charCodeAt(j + 3) << 24);
      }
      for(i = 0; i < 4; i++)
        s[i] = state[i];
      for(i = 0; i < 4; i++) {
        f = MD5_round[i][0];
        r = MD5_round[i][1];
        for(j = 0; j < 16; j++) {
          MD5_apply_round(x, s, f, abcd, r[j]);
          tmp = abcd[0];
          abcd[0] = abcd[3];
          abcd[3] = abcd[2];
          abcd[2] = abcd[1];
          abcd[1] = tmp;
        }
      }

      for(i = 0; i < 4; i++) {
        state[i] += s[i];
        state[i] = MD5_number(state[i]);
      }
    }

    return MD5_pack(state[0])
      + MD5_pack(state[1])
      + MD5_pack(state[2])
      + MD5_pack(state[3]);
  }

  var i, out, c;
  var bit128;

  bit128 = MD5_hash(sText);
  out = '';
  for(i = 0; i < 16; i++) {
    c = bit128.charCodeAt(i);
    out += '0123456789abcdef'.charAt((c>>4) & 0xf);
    out += '0123456789abcdef'.charAt(c & 0xf);
  }
  return out;
}