/**
* A JavaScript implementation of the RSA Data Security, Inc. MD5 Message
* Digest Algorithm, as defined in RFC 1321.
*
* Extends string prototype with the following method:
* md5
* 
* This extensions doesn't depend on any other code or overwrite existing methods.
*
*
* The Initial Developer of the Original Code is
* Paul Johnston
* Version 2.1 Copyright (C) Paul Johnston 1999 - 2002.
* Other contributors: Greg Holt, Andrew Kepert, Ydnar, Lostinet
* 
* Distributed under the BSD License
* See http://pajhome.org.uk/crypt/md5 for more info.
*
*
* Contributor(s):
* Harald Hanek <harald.hanek@gmail.com>
*
* Copyright (c) 2007 Harald Hanek (http://js-methods.googlecode.com)
*
* Dual licensed under the MIT (http://www.opensource.org/licenses/mit-license.php)
* and GPL (http://www.gnu.org/licenses/gpl.html) licenses.
* 
* @author Harald Hanek
* @version 0.9
* @lastchangeddate 10. October 2007 18:01:32
* @revision 876
*/

(function(){

	var md5 = 
	{
		hexcase : 0,  		/* hex output format. 0 - lowercase; 1 - uppercase        */
		b64pad  : "", 		/* base-64 pad character. "=" for strict RFC compliance   */
		chrsz   : 8, 		/* bits per input character. 8 - ASCII; 16 - Unicode      */

		/**
		* These are the functions you'll usually want to call
		* They take string arguments and return either hex or base-64 encoded strings
		*/
		'hex_md5' : function(s)
		{
			return this.binl2hex(this.core_md5(this.str2binl(s), s.length * this.chrsz));
		},
		
		'b64_md5' : function(s)
		{
			return this.binl2b64(this.core_md5(this.str2binl(s), s.length * this.chrsz));
		},
		
		'str_md5' : function(s)
		{
			return this.binl2str(this.core_md5(this.str2binl(s), s.length * this.chrsz));
		},
		
		'hex_hmac_md5' : function(key, data)
		{
			return this.binl2hex(this.core_hmac_md5(key, data));
		},
		
		'b64_hmac_md5' : function(key, data)
		{
			return this.binl2b64(this.core_hmac_md5(key, data));
		},
		
		'str_hmac_md5' : function(key, data)
		{
			return this.binl2str(this.core_hmac_md5(key, data));
		},
		
		/**
		* Calculate the MD5 of an array of little-endian words, and a bit length.
		*
		*/
		'core_md5' : function(x, len)
		{
			x[len >> 5] |= 0x80 << ((len) % 32);
			x[(((len + 64) >>> 9) << 4) + 14] = len;
			
			var a =  1732584193;
			var b = -271733879;
			var c = -1732584194;
			var d =  271733878;
			
			for(var i = 0; i < x.length; i += 16)
			{
				var olda = a;
				var oldb = b;
				var oldc = c;
				var oldd = d;
				
				a = this.md5_ff(a, b, c, d, x[i+ 0], 7 , -680876936);
				d = this.md5_ff(d, a, b, c, x[i+ 1], 12, -389564586);
				c = this.md5_ff(c, d, a, b, x[i+ 2], 17,  606105819);
				b = this.md5_ff(b, c, d, a, x[i+ 3], 22, -1044525330);
				a = this.md5_ff(a, b, c, d, x[i+ 4], 7 , -176418897);
				d = this.md5_ff(d, a, b, c, x[i+ 5], 12,  1200080426);
				c = this.md5_ff(c, d, a, b, x[i+ 6], 17, -1473231341);
				b = this.md5_ff(b, c, d, a, x[i+ 7], 22, -45705983);
				a = this.md5_ff(a, b, c, d, x[i+ 8], 7 ,  1770035416);
				d = this.md5_ff(d, a, b, c, x[i+ 9], 12, -1958414417);
				c = this.md5_ff(c, d, a, b, x[i+10], 17, -42063);
				b = this.md5_ff(b, c, d, a, x[i+11], 22, -1990404162);
				a = this.md5_ff(a, b, c, d, x[i+12], 7 ,  1804603682);
				d = this.md5_ff(d, a, b, c, x[i+13], 12, -40341101);
				c = this.md5_ff(c, d, a, b, x[i+14], 17, -1502002290);
				b = this.md5_ff(b, c, d, a, x[i+15], 22,  1236535329);
				
				a = this.md5_gg(a, b, c, d, x[i+ 1], 5 , -165796510);
				d = this.md5_gg(d, a, b, c, x[i+ 6], 9 , -1069501632);
				c = this.md5_gg(c, d, a, b, x[i+11], 14,  643717713);
				b = this.md5_gg(b, c, d, a, x[i+ 0], 20, -373897302);
				a = this.md5_gg(a, b, c, d, x[i+ 5], 5 , -701558691);
				d = this.md5_gg(d, a, b, c, x[i+10], 9 ,  38016083);
				c = this.md5_gg(c, d, a, b, x[i+15], 14, -660478335);
				b = this.md5_gg(b, c, d, a, x[i+ 4], 20, -405537848);
				a = this.md5_gg(a, b, c, d, x[i+ 9], 5 ,  568446438);
				d = this.md5_gg(d, a, b, c, x[i+14], 9 , -1019803690);
				c = this.md5_gg(c, d, a, b, x[i+ 3], 14, -187363961);
				b = this.md5_gg(b, c, d, a, x[i+ 8], 20,  1163531501);
				a = this.md5_gg(a, b, c, d, x[i+13], 5 , -1444681467);
				d = this.md5_gg(d, a, b, c, x[i+ 2], 9 , -51403784);
				c = this.md5_gg(c, d, a, b, x[i+ 7], 14,  1735328473);
				b = this.md5_gg(b, c, d, a, x[i+12], 20, -1926607734);
				
				a = this.md5_hh(a, b, c, d, x[i+ 5], 4 , -378558);
				d = this.md5_hh(d, a, b, c, x[i+ 8], 11, -2022574463);
				c = this.md5_hh(c, d, a, b, x[i+11], 16,  1839030562);
				b = this.md5_hh(b, c, d, a, x[i+14], 23, -35309556);
				a = this.md5_hh(a, b, c, d, x[i+ 1], 4 , -1530992060);
				d = this.md5_hh(d, a, b, c, x[i+ 4], 11,  1272893353);
				c = this.md5_hh(c, d, a, b, x[i+ 7], 16, -155497632);
				b = this.md5_hh(b, c, d, a, x[i+10], 23, -1094730640);
				a = this.md5_hh(a, b, c, d, x[i+13], 4 ,  681279174);
				d = this.md5_hh(d, a, b, c, x[i+ 0], 11, -358537222);
				c = this.md5_hh(c, d, a, b, x[i+ 3], 16, -722521979);
				b = this.md5_hh(b, c, d, a, x[i+ 6], 23,  76029189);
				a = this.md5_hh(a, b, c, d, x[i+ 9], 4 , -640364487);
				d = this.md5_hh(d, a, b, c, x[i+12], 11, -421815835);
				c = this.md5_hh(c, d, a, b, x[i+15], 16,  530742520);
				b = this.md5_hh(b, c, d, a, x[i+ 2], 23, -995338651);
				
				a = this.md5_ii(a, b, c, d, x[i+ 0], 6 , -198630844);
				d = this.md5_ii(d, a, b, c, x[i+ 7], 10,  1126891415);
				c = this.md5_ii(c, d, a, b, x[i+14], 15, -1416354905);
				b = this.md5_ii(b, c, d, a, x[i+ 5], 21, -57434055);
				a = this.md5_ii(a, b, c, d, x[i+12], 6 ,  1700485571);
				d = this.md5_ii(d, a, b, c, x[i+ 3], 10, -1894986606);
				c = this.md5_ii(c, d, a, b, x[i+10], 15, -1051523);
				b = this.md5_ii(b, c, d, a, x[i+ 1], 21, -2054922799);
				a = this.md5_ii(a, b, c, d, x[i+ 8], 6 ,  1873313359);
				d = this.md5_ii(d, a, b, c, x[i+15], 10, -30611744);
				c = this.md5_ii(c, d, a, b, x[i+ 6], 15, -1560198380);
				b = this.md5_ii(b, c, d, a, x[i+13], 21,  1309151649);
				a = this.md5_ii(a, b, c, d, x[i+ 4], 6 , -145523070);
				d = this.md5_ii(d, a, b, c, x[i+11], 10, -1120210379);
				c = this.md5_ii(c, d, a, b, x[i+ 2], 15,  718787259);
				b = this.md5_ii(b, c, d, a, x[i+ 9], 21, -343485551);
				
				a = this.safe_add(a, olda);
				b = this.safe_add(b, oldb);
				c = this.safe_add(c, oldc);
				d = this.safe_add(d, oldd);
			}
			return Array(a, b, c, d);
		},

		/**
		* These functions implement the four basic operations the algorithm uses.
		* 
		*/
		'md5_cmn' : function(q, a, b, x, s, t)
		{
			return this.safe_add(this.bit_rol(this.safe_add(this.safe_add(a, q), this.safe_add(x, t)), s),b);
		},
		
		'md5_ff' : function(a, b, c, d, x, s, t)
		{
			return this.md5_cmn((b & c) | ((~b) & d), a, b, x, s, t);
		},
		
		'md5_gg' : function(a, b, c, d, x, s, t)
		{
			return this.md5_cmn((b & d) | (c & (~d)), a, b, x, s, t);
		},
		
		'md5_hh' : function(a, b, c, d, x, s, t)
		{
			return this.md5_cmn(b ^ c ^ d, a, b, x, s, t);
		},
		
		'md5_ii' : function(a, b, c, d, x, s, t)
		{
			return this.md5_cmn(c ^ (b | (~d)), a, b, x, s, t);
		},

		/**
		* Calculate the HMAC-MD5, of a key and some data.
		*
		*/
		'core_hmac_md5' : function(key, data)
		{
			var bkey = this.str2binl(key);
			if(bkey.length > 16)
				bkey = this.core_md5(bkey, key.length * this.chrsz);
			
			var ipad = Array(16), opad = Array(16);
			for(var i = 0; i < 16; i++) 
			{
				ipad[i] = bkey[i] ^ 0x36363636;
				opad[i] = bkey[i] ^ 0x5C5C5C5C;
			}
			
			var hash = this.core_md5(ipad.concat(this.str2binl(data)), 512 + data.length * this.chrsz);
			return this.core_md5(opad.concat(hash), 512 + 128);
		},


		/**
		* Add integers, wrapping at 2^32. This uses 16-bit operations internally
		* to work around bugs in some JS interpreters.
		*
		*/
		'safe_add' : function(x, y)
		{
			var lsw = (x & 0xFFFF) + (y & 0xFFFF);
			var msw = (x >> 16) + (y >> 16) + (lsw >> 16);
			return (msw << 16) | (lsw & 0xFFFF);
		},
		
		/**
		* Bitwise rotate a 32-bit number to the left.
		*
		*/
		'bit_rol' : function(num, cnt)
		{
			return (num << cnt) | (num >>> (32 - cnt));
		},
		
		/**
		* Convert a string to an array of little-endian words.
		* If this.chrsz is ASCII, characters >255 have their hi-byte silently ignored.
		*
		*/
		'str2binl' : function(str)
		{
			var bin = Array();
			var mask = (1 << this.chrsz) - 1;
			for(var i = 0; i < str.length * this.chrsz; i += this.chrsz)
				bin[i>>5] |= (str.charCodeAt(i / this.chrsz) & mask) << (i%32);
			return bin;
		},
		
		/**
		* Convert an array of little-endian words to a string
		*
		*/
		'binl2str' : function(bin)
		{
			var str = "";
			var mask = (1 << this.chrsz) - 1;
			for(var i = 0; i < bin.length * 32; i += this.chrsz)
				str += String.fromCharCode((bin[i>>5] >>> (i % 32)) & mask);
			return str;
		},
		
		/**
		* Convert an array of little-endian words to a hex string.
		*
		*/
		'binl2hex' : function(binarray)
		{
			var hex_tab = this.hexcase ? "0123456789ABCDEF" : "0123456789abcdef";
			var str = "";
			for(var i = 0; i < binarray.length * 4; i++)
			{
				str += hex_tab.charAt((binarray[i>>2] >> ((i%4)*8+4)) & 0xF) +
				hex_tab.charAt((binarray[i>>2] >> ((i%4)*8  )) & 0xF);
			}
			return str;
		},
		
		/**
		* Convert an array of little-endian words to a base-64 string
		*
		*/
		'binl2b64' : function(binarray)
		{
			var tab = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
			var str = "";
			for(var i = 0; i < binarray.length * 4; i += 3)
			{
				var triplet = (((binarray[i   >> 2] >> 8 * ( i   %4)) & 0xFF) << 16)
				| (((binarray[i+1 >> 2] >> 8 * ((i+1)%4)) & 0xFF) << 8 )
				|  ((binarray[i+2 >> 2] >> 8 * ((i+2)%4)) & 0xFF);
				for(var j = 0; j < 4; j++)
				{
					if(i * 8 + j * 6 > binarray.length * 32)
						str += this.b64pad;
					else
						str += tab.charAt((triplet >> 6*(3-j)) & 0x3F);
				}
			}
			return str;
		}
	};

	/**
	* Returns the md5 hash of the given string.
	*
	* @example "JavaScript".md5();
	* @result "686155af75a60a0f6e9d80c1f7edd3e9"
	*
	* @name md5
	* @return String
	*/
	if(!String.prototype.md5)
		String.prototype.md5 = function()
		{
			return md5.hex_md5(this);
		}
})();