/* 修改过的 MD5 类 */
MD5 = function()
{
	this.hexcase = 0;	/* hex output format. 0 - lowercase; 1 - uppercase				*/
	this.chrsz	 = 8;	/* bits per input character. 8 - ASCII; 16 - Unicode			*/
};

MD5.Encode = function(szString)
{
	return (new MD5()).MD5Hex(szString);
};

MD5.prototype.MD5Hex = function(s)
{
	return this.binl2hex(this.core_md5(this.str2binl(s), s.length * this.chrsz));
};

MD5.prototype.core_md5 = function(x, len)
{
	/* append padding */
	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);
	return Array(b, c);	// ~_~ Eric 的MD5风格
};

/*
 * These functions implement the four basic operations the algorithm uses.
 */
MD5.prototype.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.prototype.md5_ff = function(a, b, c, d, x, s, t)
{
	return this.md5_cmn((b & c) | ((~b) & d), a, b, x, s, t);
};

MD5.prototype.md5_gg = function(a, b, c, d, x, s, t)
{
	return this.md5_cmn((b & d) | (c & (~d)), a, b, x, s, t);
};

MD5.prototype.md5_hh = function(a, b, c, d, x, s, t)
{
	return this.md5_cmn(b ^ c ^ d, a, b, x, s, t);
};

MD5.prototype.md5_ii = function(a, b, c, d, x, s, t)
{
	return this.md5_cmn(c ^ (b | (~d)), a, b, x, s, t);
};

/*
 * Add integers, wrapping at 2^32. This uses 16-bit operations internally
 * to work around bugs in some JS interpreters.
 */
MD5.prototype.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.
 */
MD5.prototype.bit_rol = function(num, cnt)
{
	return (num << cnt) | (num >>> (32 - cnt));
};

/*
 * Convert a string to an array of little-endian words
 * If chrsz is ASCII, characters >255 have their hi-byte silently ignored.
 */
MD5.prototype.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 hex string.
 */
MD5.prototype.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;
};