明文暴露___JS前台加密,java后台解密实现

1.前台JS

 1 <script type="text/javascript">  
 2     $(function() {  
 3         $("#btn").click(function() {  
 4             var username = encode64($("#username").val());  //对数据加密  
 5             var password = encode64($("#password").val());  
 6             $("#username").val(username);  
 7             $("#password").val(password);  
 8             document.fm.submit();  //fm为form表单name  
 9         })  
10     })  
11       
12     // base64加密开始  
13     var keyStr = "ABCDEFGHIJKLMNOP" + "QRSTUVWXYZabcdef" + "ghijklmnopqrstuv"  
14             + "wxyz0123456789+/" + "=";  
15       
16     function encode64(input) {  
17   
18         var output = "";  
19         var chr1, chr2, chr3 = "";  
20         var enc1, enc2, enc3, enc4 = "";  
21         var i = 0;  
22         do {  
23             chr1 = input.charCodeAt(i++);  
24             chr2 = input.charCodeAt(i++);  
25             chr3 = input.charCodeAt(i++);  
26             enc1 = chr1 >> 2;  
27             enc2 = ((chr1 & 3) << 4) | (chr2 >> 4);  
28             enc3 = ((chr2 & 15) << 2) | (chr3 >> 6);  
29             enc4 = chr3 & 63;  
30             if (isNaN(chr2)) {  
31                 enc3 = enc4 = 64;  
32             } else if (isNaN(chr3)) {  
33                 enc4 = 64;  
34             }  
35             output = output + keyStr.charAt(enc1) + keyStr.charAt(enc2)  
36                     + keyStr.charAt(enc3) + keyStr.charAt(enc4);  
37             chr1 = chr2 = chr3 = "";  
38             enc1 = enc2 = enc3 = enc4 = "";  
39         } while (i < input.length);  
40   
41         return output;  
42     }  
43     // base64加密结束  
44 </script> 

2、后台java代码

 1 private static char[] base64EncodeChars = new char[] { 'A', 'B', 'C', 'D',  
 2         'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P', 'Q',  
 3         'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z', 'a', 'b', 'c', 'd',  
 4         'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n', 'o', 'p', 'q',  
 5         'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z', '0', '1', '2', '3',  
 6         '4', '5', '6', '7', '8', '9', '+', '/', };  
 7   
 8 private static byte[] base64DecodeChars = new byte[] { -1, -1, -1, -1, -1,  
 9         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  
10         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  
11         -1, -1, -1, -1, 62, -1, -1, -1, 63, 52, 53, 54, 55, 56, 57, 58, 59,  
12         60, 61, -1, -1, -1, -1, -1, -1, -1, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,  
13         10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1,  
14         -1, -1, -1, -1, -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37,  
15         38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1,  
16         -1, -1 };  
17   
18 /** 
19  * 解密 
20  * @param str 
21  * @return 
22  */  
23 public static byte[] decode(String str) {  
24     byte[] data = str.getBytes();  
25     int len = data.length;  
26     ByteArrayOutputStream buf = new ByteArrayOutputStream(len);  
27     int i = 0;  
28     int b1, b2, b3, b4;  
29   
30     while (i < len) {  
31         do {  
32             b1 = base64DecodeChars[data[i++]];  
33         } while (i < len && b1 == -1);  
34         if (b1 == -1) {  
35             break;  
36         }  
37   
38         do {  
39             b2 = base64DecodeChars[data[i++]];  
40         } while (i < len && b2 == -1);  
41         if (b2 == -1) {  
42             break;  
43         }  
44         buf.write((int) ((b1 << 2) | ((b2 & 0x30) >>> 4)));  
45   
46         do {  
47             b3 = data[i++];  
48             if (b3 == 61) {  
49                 return buf.toByteArray();  
50             }  
51             b3 = base64DecodeChars[b3];  
52         } while (i < len && b3 == -1);  
53         if (b3 == -1) {  
54             break;  
55         }  
56         buf.write((int) (((b2 & 0x0f) << 4) | ((b3 & 0x3c) >>> 2)));  
57   
58         do {  
59             b4 = data[i++];  
60             if (b4 == 61) {  
61                 return buf.toByteArray();  
62             }  
63             b4 = base64DecodeChars[b4];  
64         } while (i < len && b4 == -1);  
65         if (b4 == -1) {  
66             break;  
67         }  
68         buf.write((int) (((b3 & 0x03) << 6) | b4));  
69     }  
70     return buf.toByteArray();  
71 }  
72 
73 
74 System.out.println(new String(decode(username)));  // 使用decode()方法进行解密