如何用js或jQuery实现md5加密方式

很多人会说，客户端的加密都形同虚设。互联网上最好的加密方式还是通过https来实现，但是它成本高、操作不便。

一般来讲，js加密，只要知道网站的js源代码，便容易存在被破解的可能性；md5具有不可逆、破解成本高的特点。用明文方式传输用户密码，可以说是不可取的行为。而使用js的md5来加密用户密码，传到服务器端再将md5值二次加密处理存到数据库中，可以从一定程度上让攻击者提高成本和难度。

以下是jQuery的md5加密插件，大家可以复制下载下来使用。

/**
* 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) {
return (x & z) | (y & (~ z));
}

var H = function(x, y, z) {
return (x ^ y ^ z);
}

var I = function(x, y, z) {
return (y ^ (x | (~ z)));
}

var FF = function(a, b, c, d, x, s, ac) {
a = addUnsigned(a, addUnsigned(addUnsigned(F(b, c, d), x), ac));
return addUnsigned(rotateLeft(a, s), b);
};

var GG = function(a, b, c, d, x, s, ac) {
a = addUnsigned(a, addUnsigned(addUnsigned(G(b, c, d), x), ac));
return addUnsigned(rotateLeft(a, s), b);
};

var HH = function(a, b, c, d, x, s, ac) {
a = addUnsigned(a, addUnsigned(addUnsigned(H(b, c, d), x), ac));
return addUnsigned(rotateLeft(a, s), b);
};

var II = function(a, b, c, d, x, s, ac) {
a = addUnsigned(a, addUnsigned(addUnsigned(I(b, c, d), x), ac));
return addUnsigned(rotateLeft(a, s), b);
};

var convertToWordArray = function(string) {
var lWordCount;
var lMessageLength = string.length;
var lNumberOfWordsTempOne = lMessageLength + 8;
var lNumberOfWordsTempTwo = (lNumberOfWordsTempOne - (lNumberOfWordsTempOne % 64)) / 64;
var lNumberOfWords = (lNumberOfWordsTempTwo + 1) * 16;
var lWordArray = Array(lNumberOfWords - 1);
var lBytePosition = 0;
var lByteCount = 0;
while (lByteCount < lMessageLength) {
lWordCount = (lByteCount - (lByteCount % 4)) / 4;
lBytePosition = (lByteCount % 4) * 8;
lWordArray[lWordCount] = (lWordArray[lWordCount] | (string.charCodeAt(lByteCount) << lBytePosition));
lByteCount++;
}
lWordCount = (lByteCount - (lByteCount % 4)) / 4;
lBytePosition = (lByteCount % 4) * 8;
lWordArray[lWordCount] = lWordArray[lWordCount] | (0x80 << lBytePosition);
lWordArray[lNumberOfWords - 2] = lMessageLength << 3;
lWordArray[lNumberOfWords - 1] = lMessageLength >>> 29;
return lWordArray;
};

var wordToHex = function(lValue) {
var WordToHexValue = "", WordToHexValueTemp = "", lByte, lCount;
for (lCount = 0; lCount <= 3; lCount++) {
lByte = (lValue >>> (lCount * 8)) & 255;
WordToHexValueTemp = "0" + lByte.toString(16);
WordToHexValue = WordToHexValue + WordToHexValueTemp.substr(WordToHexValueTemp.length - 2, 2);
}
return WordToHexValue;
};

var uTF8Encode = function(string) {
string = string.replace(/x0dx0a/g, "x0a");
var output = "";
for (var n = 0; n < string.length; n++) {
var c = string.charCodeAt(n);
if (c < 128) {
output += String.fromCharCode(c);
} else if ((c > 127) && (c < 2048)) {
output += String.fromCharCode((c >> 6) | 192);
output += String.fromCharCode((c & 63) | 128);
} else {
output += String.fromCharCode((c >> 12) | 224);
output += String.fromCharCode(((c >> 6) & 63) | 128);
output += String.fromCharCode((c & 63) | 128);
}
}
return output;
};

$.extend({
md5: function(string) {
var x = Array();
var k, AA, BB, CC, DD, a, b, c, d;
var S11=7, S12=12, S13=17, S14=22;
var S21=5, S22=9 , S23=14, S24=20;
var S31=4, S32=11, S33=16, S34=23;
var S41=6, S42=10, S43=15, S44=21;
string = uTF8Encode(string);
x = convertToWordArray(string);
a = 0x67452301; b = 0xEFCDAB89; c = 0x98BADCFE; d = 0x10325476;
for (k = 0; k < x.length; k += 16) {
AA = a; BB = b; CC = c; DD = d;
a = FF(a, b, c, d, x[k+0],  S11, 0xD76AA478);
d = FF(d, a, b, c, x[k+1],  S12, 0xE8C7B756);
c = FF(c, d, a, b, x[k+2],  S13, 0x242070DB);
b = FF(b, c, d, a, x[k+3],  S14, 0xC1BDCEEE);
a = FF(a, b, c, d, x[k+4],  S11, 0xF57C0FAF);
d = FF(d, a, b, c, x[k+5],  S12, 0x4787C62A);
c = FF(c, d, a, b, x[k+6],  S13, 0xA8304613);
b = FF(b, c, d, a, x[k+7],  S14, 0xFD469501);
a = FF(a, b, c, d, x[k+8],  S11, 0x698098D8);
d = FF(d, a, b, c, x[k+9],  S12, 0x8B44F7AF);
c = FF(c, d, a, b, x[k+10], S13, 0xFFFF5BB1);
b = FF(b, c, d, a, x[k+11], S14, 0x895CD7BE);
a = FF(a, b, c, d, x[k+12], S11, 0x6B901122);
d = FF(d, a, b, c, x[k+13], S12, 0xFD987193);
c = FF(c, d, a, b, x[k+14], S13, 0xA679438E);
b = FF(b, c, d, a, x[k+15], S14, 0x49B40821);
a = GG(a, b, c, d, x[k+1],  S21, 0xF61E2562);
d = GG(d, a, b, c, x[k+6],  S22, 0xC040B340);
c = GG(c, d, a, b, x[k+11], S23, 0x265E5A51);
b = GG(b, c, d, a, x[k+0],  S24, 0xE9B6C7AA);
a = GG(a, b, c, d, x[k+5],  S21, 0xD62F105D);
d = GG(d, a, b, c, x[k+10], S22, 0x2441453);
c = GG(c, d, a, b, x[k+15], S23, 0xD8A1E681);
b = GG(b, c, d, a, x[k+4],  S24, 0xE7D3FBC8);
a = GG(a, b, c, d, x[k+9],  S21, 0x21E1CDE6);
d = GG(d, a, b, c, x[k+14], S22, 0xC33707D6);
c = GG(c, d, a, b, x[k+3],  S23, 0xF4D50D87);
b = GG(b, c, d, a, x[k+8],  S24, 0x455A14ED);
a = GG(a, b, c, d, x[k+13], S21, 0xA9E3E905);
d = GG(d, a, b, c, x[k+2],  S22, 0xFCEFA3F8);
c = GG(c, d, a, b, x[k+7],  S23, 0x676F02D9);
b = GG(b, c, d, a, x[k+12], S24, 0x8D2A4C8A);
a = HH(a, b, c, d, x[k+5],  S31, 0xFFFA3942);
d = HH(d, a, b, c, x[k+8],  S32, 0x8771F681);
c = HH(c, d, a, b, x[k+11], S33, 0x6D9D6122);
b = HH(b, c, d, a, x[k+14], S34, 0xFDE5380C);
a = HH(a, b, c, d, x[k+1],  S31, 0xA4BEEA44);
d = HH(d, a, b, c, x[k+4],  S32, 0x4BDECFA9);
c = HH(c, d, a, b, x[k+7],  S33, 0xF6BB4B60);
b = HH(b, c, d, a, x[k+10], S34, 0xBEBFBC70);
a = HH(a, b, c, d, x[k+13], S31, 0x289B7EC6);
d = HH(d, a, b, c, x[k+0],  S32, 0xEAA127FA);
c = HH(c, d, a, b, x[k+3],  S33, 0xD4EF3085);
b = HH(b, c, d, a, x[k+6],  S34, 0x4881D05);
a = HH(a, b, c, d, x[k+9],  S31, 0xD9D4D039);
d = HH(d, a, b, c, x[k+12], S32, 0xE6DB99E5);
c = HH(c, d, a, b, x[k+15], S33, 0x1FA27CF8);
b = HH(b, c, d, a, x[k+2],  S34, 0xC4AC5665);
a = II(a, b, c, d, x[k+0],  S41, 0xF4292244);
d = II(d, a, b, c, x[k+7],  S42, 0x432AFF97);
c = II(c, d, a, b, x[k+14], S43, 0xAB9423A7);
b = II(b, c, d, a, x[k+5],  S44, 0xFC93A039);
a = II(a, b, c, d, x[k+12], S41, 0x655B59C3);
d = II(d, a, b, c, x[k+3],  S42, 0x8F0CCC92);
c = II(c, d, a, b, x[k+10], S43, 0xFFEFF47D);
b = II(b, c, d, a, x[k+1],  S44, 0x85845DD1);
a = II(a, b, c, d, x[k+8],  S41, 0x6FA87E4F);
d = II(d, a, b, c, x[k+15], S42, 0xFE2CE6E0);
c = II(c, d, a, b, x[k+6],  S43, 0xA3014314);
b = II(b, c, d, a, x[k+13], S44, 0x4E0811A1);
a = II(a, b, c, d, x[k+4],  S41, 0xF7537E82);
d = II(d, a, b, c, x[k+11], S42, 0xBD3AF235);
c = II(c, d, a, b, x[k+2],  S43, 0x2AD7D2BB);
b = II(b, c, d, a, x[k+9],  S44, 0xEB86D391);
a = addUnsigned(a, AA);
b = addUnsigned(b, BB);
c = addUnsigned(c, CC);
d = addUnsigned(d, DD);
}
var tempValue = wordToHex(a) + wordToHex(b) + wordToHex(c) + wordToHex(d);
return tempValue.toLowerCase();
}
});
})(jQuery);

var rss = $.md5("你想要加密的字符串");

function md5(string) {
function md5_RotateLeft(lValue, iShiftBits) {
return (lValue << iShiftBits) | (lValue >>> (32 - iShiftBits));
}
function md5_AddUnsigned(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);
}
}
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)));
}
function md5_FF(a, b, c, d, x, s, ac) {
a = md5_AddUnsigned(a, md5_AddUnsigned(md5_AddUnsigned(md5_F(b, c, d),
x), ac));
return md5_AddUnsigned(md5_RotateLeft(a, s), b);
}
function md5_GG(a, b, c, d, x, s, ac) {
a = md5_AddUnsigned(a, md5_AddUnsigned(md5_AddUnsigned(md5_G(b, c, d),
x), ac));
return md5_AddUnsigned(md5_RotateLeft(a, s), b);
}
function md5_HH(a, b, c, d, x, s, ac) {
a = md5_AddUnsigned(a, md5_AddUnsigned(md5_AddUnsigned(md5_H(b, c, d),
x), ac));
return md5_AddUnsigned(md5_RotateLeft(a, s), b);
}
function md5_II(a, b, c, d, x, s, ac) {
a = md5_AddUnsigned(a, md5_AddUnsigned(md5_AddUnsigned(md5_I(b, c, d),
x), ac));
return md5_AddUnsigned(md5_RotateLeft(a, s), b);
}
function md5_ConvertToWordArray(string) {
var lWordCount;
var lMessageLength = string.length;
var lNumberOfWords_temp1 = lMessageLength + 8;
var lNumberOfWords_temp2 = (lNumberOfWords_temp1 - (lNumberOfWords_temp1 % 64)) / 64;
var lNumberOfWords = (lNumberOfWords_temp2 + 1) * 16;
var lWordArray = Array(lNumberOfWords - 1);
var lBytePosition = 0;
var lByteCount = 0;
while (lByteCount < lMessageLength) {
lWordCount = (lByteCount - (lByteCount % 4)) / 4;
lBytePosition = (lByteCount % 4) * 8;
lWordArray[lWordCount] = (lWordArray[lWordCount] | (string
.charCodeAt(lByteCount) << lBytePosition));
lByteCount++;
}
lWordCount = (lByteCount - (lByteCount % 4)) / 4;
lBytePosition = (lByteCount % 4) * 8;
lWordArray[lWordCount] = lWordArray[lWordCount]
| (0x80 << lBytePosition);
lWordArray[lNumberOfWords - 2] = lMessageLength << 3;
lWordArray[lNumberOfWords - 1] = lMessageLength >>> 29;
return lWordArray;
}
function md5_WordToHex(lValue) {
var WordToHexValue = "", WordToHexValue_temp = "", lByte, lCount;
for(lCount = 0; lCount <= 3; lCount++) {
lByte = (lValue >>> (lCount * 8)) & 255;
WordToHexValue_temp = "0" + lByte.toString(16);
WordToHexValue = WordToHexValue
+ WordToHexValue_temp.substr(
WordToHexValue_temp.length - 2, 2);
}
return WordToHexValue;
}
function md5_Utf8Encode(string) {
string = string.replace(/
/g, "
");
var utftext = "";
for( var n = 0; n < string.length; n++) {
var c = string.charCodeAt(n);
if (c < 128) {
utftext += String.fromCharCode(c);
} else if ((c > 127) && (c < 2048)) {
utftext += String.fromCharCode((c >> 6) | 192);
utftext += String.fromCharCode((c & 63) | 128);
} else {
utftext += String.fromCharCode((c >> 12) | 224);
utftext += String.fromCharCode(((c >> 6) & 63) | 128);
utftext += String.fromCharCode((c & 63) | 128);
}
}
return utftext;
}
var x = Array();
var k, AA, BB, CC, DD, a, b, c, d;
var S11 = 7, S12 = 12, S13 = 17, S14 = 22;
var S21 = 5, S22 = 9, S23 = 14, S24 = 20;
var S31 = 4, S32 = 11, S33 = 16, S34 = 23;
var S41 = 6, S42 = 10, S43 = 15, S44 = 21;
string = md5_Utf8Encode(string);
x = md5_ConvertToWordArray(string);
a = 0x67452301;
b = 0xEFCDAB89;
c = 0x98BADCFE;
d = 0x10325476;
for(k = 0; k < x.length; k += 16) {
AA = a;
BB = b;
CC = c;
DD = d;
a = md5_FF(a, b, c, d, x[k + 0], S11, 0xD76AA478);
d = md5_FF(d, a, b, c, x[k + 1], S12, 0xE8C7B756);
c = md5_FF(c, d, a, b, x[k + 2], S13, 0x242070DB);
b = md5_FF(b, c, d, a, x[k + 3], S14, 0xC1BDCEEE);
a = md5_FF(a, b, c, d, x[k + 4], S11, 0xF57C0FAF);
d = md5_FF(d, a, b, c, x[k + 5], S12, 0x4787C62A);
c = md5_FF(c, d, a, b, x[k + 6], S13, 0xA8304613);
b = md5_FF(b, c, d, a, x[k + 7], S14, 0xFD469501);
a = md5_FF(a, b, c, d, x[k + 8], S11, 0x698098D8);
d = md5_FF(d, a, b, c, x[k + 9], S12, 0x8B44F7AF);
c = md5_FF(c, d, a, b, x[k + 10], S13, 0xFFFF5BB1);
b = md5_FF(b, c, d, a, x[k + 11], S14, 0x895CD7BE);
a = md5_FF(a, b, c, d, x[k + 12], S11, 0x6B901122);
d = md5_FF(d, a, b, c, x[k + 13], S12, 0xFD987193);
c = md5_FF(c, d, a, b, x[k + 14], S13, 0xA679438E);
b = md5_FF(b, c, d, a, x[k + 15], S14, 0x49B40821);
a = md5_GG(a, b, c, d, x[k + 1], S21, 0xF61E2562);
d = md5_GG(d, a, b, c, x[k + 6], S22, 0xC040B340);
c = md5_GG(c, d, a, b, x[k + 11], S23, 0x265E5A51);
b = md5_GG(b, c, d, a, x[k + 0], S24, 0xE9B6C7AA);
a = md5_GG(a, b, c, d, x[k + 5], S21, 0xD62F105D);
d = md5_GG(d, a, b, c, x[k + 10], S22, 0x2441453);
c = md5_GG(c, d, a, b, x[k + 15], S23, 0xD8A1E681);
b = md5_GG(b, c, d, a, x[k + 4], S24, 0xE7D3FBC8);
a = md5_GG(a, b, c, d, x[k + 9], S21, 0x21E1CDE6);
d = md5_GG(d, a, b, c, x[k + 14], S22, 0xC33707D6);
c = md5_GG(c, d, a, b, x[k + 3], S23, 0xF4D50D87);
b = md5_GG(b, c, d, a, x[k + 8], S24, 0x455A14ED);
a = md5_GG(a, b, c, d, x[k + 13], S21, 0xA9E3E905);
d = md5_GG(d, a, b, c, x[k + 2], S22, 0xFCEFA3F8);
c = md5_GG(c, d, a, b, x[k + 7], S23, 0x676F02D9);
b = md5_GG(b, c, d, a, x[k + 12], S24, 0x8D2A4C8A);
a = md5_HH(a, b, c, d, x[k + 5], S31, 0xFFFA3942);
d = md5_HH(d, a, b, c, x[k + 8], S32, 0x8771F681);
c = md5_HH(c, d, a, b, x[k + 11], S33, 0x6D9D6122);
b = md5_HH(b, c, d, a, x[k + 14], S34, 0xFDE5380C);
a = md5_HH(a, b, c, d, x[k + 1], S31, 0xA4BEEA44);
d = md5_HH(d, a, b, c, x[k + 4], S32, 0x4BDECFA9);
c = md5_HH(c, d, a, b, x[k + 7], S33, 0xF6BB4B60);
b = md5_HH(b, c, d, a, x[k + 10], S34, 0xBEBFBC70);
a = md5_HH(a, b, c, d, x[k + 13], S31, 0x289B7EC6);
d = md5_HH(d, a, b, c, x[k + 0], S32, 0xEAA127FA);
c = md5_HH(c, d, a, b, x[k + 3], S33, 0xD4EF3085);
b = md5_HH(b, c, d, a, x[k + 6], S34, 0x4881D05);
a = md5_HH(a, b, c, d, x[k + 9], S31, 0xD9D4D039);
d = md5_HH(d, a, b, c, x[k + 12], S32, 0xE6DB99E5);
c = md5_HH(c, d, a, b, x[k + 15], S33, 0x1FA27CF8);
b = md5_HH(b, c, d, a, x[k + 2], S34, 0xC4AC5665);
a = md5_II(a, b, c, d, x[k + 0], S41, 0xF4292244);
d = md5_II(d, a, b, c, x[k + 7], S42, 0x432AFF97);
c = md5_II(c, d, a, b, x[k + 14], S43, 0xAB9423A7);
b = md5_II(b, c, d, a, x[k + 5], S44, 0xFC93A039);
a = md5_II(a, b, c, d, x[k + 12], S41, 0x655B59C3);
d = md5_II(d, a, b, c, x[k + 3], S42, 0x8F0CCC92);
c = md5_II(c, d, a, b, x[k + 10], S43, 0xFFEFF47D);
b = md5_II(b, c, d, a, x[k + 1], S44, 0x85845DD1);
a = md5_II(a, b, c, d, x[k + 8], S41, 0x6FA87E4F);
d = md5_II(d, a, b, c, x[k + 15], S42, 0xFE2CE6E0);
c = md5_II(c, d, a, b, x[k + 6], S43, 0xA3014314);
b = md5_II(b, c, d, a, x[k + 13], S44, 0x4E0811A1);
a = md5_II(a, b, c, d, x[k + 4], S41, 0xF7537E82);
d = md5_II(d, a, b, c, x[k + 11], S42, 0xBD3AF235);
c = md5_II(c, d, a, b, x[k + 2], S43, 0x2AD7D2BB);
b = md5_II(b, c, d, a, x[k + 9], S44, 0xEB86D391);
a = md5_AddUnsigned(a, AA);
b = md5_AddUnsigned(b, BB);
c = md5_AddUnsigned(c, CC);
d = md5_AddUnsigned(d, DD);
}
return (md5_WordToHex(a) + md5_WordToHex(b) + md5_WordToHex(c) + md5_WordToHex(d)).toLowerCase();
}