jquery的MD5

/**
 * jQuery MD5 hash algorithm function
 * 
 *  <code>
 *  Calculate the md5 hash of a String 
 *  String $.md5 ( String str )
 *  </code>
 * 
 * Calculates the MD5 hash of str using the » RSA Data Security, Inc. MD5 Message-Digest Algorithm, and returns that hash. 
 * MD5 (Message-Digest algorithm 5) is a widely-used cryptographic hash function with a 128-bit hash value. MD5 has been employed in a wide variety of security applications, and is also commonly used to check the integrity of data. The generated hash is also non-reversable. Data cannot be retrieved from the message digest, the digest uniquely identifies the data.
 * MD5 was developed by Professor Ronald L. Rivest in 1994. Its 128 bit (16 byte) message digest makes it a faster implementation than SHA-1.
 * This script is used to process a variable length message into a fixed-length output of 128 bits using the MD5 algorithm. It is fully compatible with UTF-8 encoding. It is very useful when u want to transfer encrypted passwords over the internet. If you plan using UTF-8 encoding in your project don't forget to set the page encoding to UTF-8 (Content-Type meta tag). 
 * This function orginally get from the WebToolkit and rewrite for using as the jQuery plugin.
 * 
 * Example
 *  Code
 *  <code>
 *  $.md5("I'm Persian."); 
 *  </code>
 *  Result
 *  <code>
 *  "b8c901d0f02223f9761016cfff9d68df"
 *  </code>
 * 
 * @alias Muhammad Hussein Fattahizadeh < muhammad [AT] semnanweb [DOT] com >
 * @link http://www.semnanweb.com/jquery-plugin/md5.html
 * @see http://www.webtoolkit.info/
 * @license http://www.gnu.org/licenses/gpl.html [GNU General Public License]
 * @param {jQuery} {md5:function(string))

 * @return string
 */

(function($){

var rotateLeft = function(lValue, iShiftBits) {
return (lValue << iShiftBits) | (lValue >>> (32 - iShiftBits));
}

var addUnsigned = function(lX, lY) {
var lX4, lY4, lX8, lY8, lResult;
lX8 = (lX & 0x80000000);
lY8 = (lY & 0x80000000);
lX4 = (lX & 0x40000000);
lY4 = (lY & 0x40000000);
lResult = (lX & 0x3FFFFFFF) + (lY & 0x3FFFFFFF);
if (lX4 & lY4) return (lResult ^ 0x80000000 ^ lX8 ^ lY8);
if (lX4 | lY4) {
if (lResult & 0x40000000) return (lResult ^ 0xC0000000 ^ lX8 ^ lY8);
else return (lResult ^ 0x40000000 ^ lX8 ^ lY8);
} else {
return (lResult ^ lX8 ^ lY8);
}
}

var F = function(x, y, z) {
return (x & y) | ((~ x) & z);
}

var G = function(x, y, z) {