數據加密：
1. 在表單提提交時使用js加密
2. 在提交到服務器，後臺實現對數據的解密
3. 解密後可以對數據進行一定的處理，添加到session，response。或添加到數據庫中
4. 提交的加密數據 ，解密後與數據庫中的數據比較（數據庫中的數據是未加密的）
5. 後臺數據返回頁面進行加密，在頁面時使用js解密
6. js加密實現對http傳輸之前的加密
7. 後臺和js加密使用同一種加密技術，
8. 爲了解密所以不使用md5加密，實例使用base64加密解密
參考http://www.cnblogs.com/mofish/archive/2012/02/25/2367858.html
Base64.js
/**
*
* Base64 encode / decode
*
* @author haitao.tu
* @date 2010-04-26
* @email [email protected]
*
*/
function Base64() {
// private property
_keyStr = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
// public method for encoding
this.encode = function (input) {
var output = "";
var chr1, chr2, chr3, enc1, enc2, enc3, enc4;
var i = 0;
input = _utf8_encode(input);
while (i < input.length) {
chr1 = input.charCodeAt(i++);
chr2 = input.charCodeAt(i++);
chr3 = input.charCodeAt(i++);
enc1 = chr1 >> 2;
enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);
enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);
enc4 = chr3 & 63;
if (isNaN(chr2)) {
enc3 = enc4 = 64;
} else if (isNaN(chr3)) {
enc4 = 64;
}
output = output +
_keyStr.charAt(enc1) + _keyStr.charAt(enc2) +
_keyStr.charAt(enc3) + _keyStr.charAt(enc4);
}
return output;
}
// public method for decoding
this.decode = function (input) {
var output = "";
var chr1, chr2, chr3;
var enc1, enc2, enc3, enc4;
var i = 0;
input = input.replace(/[^A-Za-z0-9\+\/\=]/g, "");
while (i < input.length) {
enc1 = _keyStr.indexOf(input.charAt(i++));
enc2 = _keyStr.indexOf(input.charAt(i++));
enc3 = _keyStr.indexOf(input.charAt(i++));
enc4 = _keyStr.indexOf(input.charAt(i++));
chr1 = (enc1 << 2) | (enc2 >> 4);
chr2 = ((enc2 & 15) << 4) | (enc3 >> 2);
chr3 = ((enc3 & 3) << 6) | enc4;
output = output + String.fromCharCode(chr1);
if (enc3 != 64) {
output = output + String.fromCharCode(chr2);
}
if (enc4 != 64) {
output = output + String.fromCharCode(chr3);
}
}
output = _utf8_decode(output);
return output;
}
// private method for UTF-8 encoding
_utf8_encode = function (string) {
string = string.replace(/\r\n/g,"\n");
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;
}
// private method for UTF-8 decoding
_utf8_decode = function (utftext) {
var string = "";
var i = 0;
var c = c1 = c2 = 0;
while ( i < utftext.length ) {
c = utftext.charCodeAt(i);
if (c < 128) {
string += String.fromCharCode(c);
i++;
} else if((c > 191) && (c < 224)) {
c2 = utftext.charCodeAt(i+1);
string += String.fromCharCode(((c & 31) << 6) | (c2 & 63));
i += 2;
} else {
c2 = utftext.charCodeAt(i+1);
c3 = utftext.charCodeAt(i+2);
string += String.fromCharCode(((c & 15) << 12) | ((c2 & 63) << 6) | (c3 & 63));
i += 3;
}
}
return string;
}
}
base64.html
<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<title>base64加密</title>
<script type="text/javascript" src="base64.js"></script>
<script type="text/javascript">
var b = new Base64();
var str = b.encode("msms");
var str1 = b.encode("ms");
var str2 = b.encode("m");
alert("base64 encode:" + str+" "+str1+" "+str2+" ");
//解密
str = b.decode(str);
alert("base64 decode:" + str);
</script>
</head>
<body>
</body>
</html>
asp.net後臺base64的加解密
// <summary>
// Base64加密
// </summary>
// <param name="Message"></param>
// <returns></returns>
public string Base64Encode(string Message)
{
if (Message == "") {
return "";
}else{
byte[] bytes = System.Text.Encoding.Default.GetBytes(Message);
return Convert.ToBase64String(bytes);
}
}
// <summary>
// Base64解密
// </summary>
// <param name="Message"></param>
// <returns></returns>
public string Base64Decode(string Message)
{
if (Message == ""){
return "";
}else{
byte[] bytes = Convert.FromBase64String(Message);
return System.Text.Encoding.Default.GetString(bytes);
}
}