code: function str2blks_MD5(str)
  {
    nblk = ((str.length + 8) >> 6) + 1;
    blks = new Array(nblk * 16);
    for(i = 0; i < nblk * 16; i++) blks[i] = 0;
    for(i = 0; i < str.length; i++)
      blks[i >> 2] |= str.charCodeAt(i) << ((i % 4) * 8);
    blks[i >> 2] |= 0x80 << ((i % 4) * 8);
    blks[nblk * 16 - 2] = str.length * 8;
    return blks;
  }
docs: /*
  Convert a string to a sequence of 16-word blocks, stored as an array.
  Append padding bits and the length, as described in the MD5 standard.