Android AES加密算法及其实现

Myth丶恋晨 2022-07-28 04:14 136阅读 0赞

昨天老大叫我看看android加密算法。于是网上找了找，找到了AES加密算法。（当然还有MD5,BASE64什么的[http://snowolf.iteye.com/blog/379860][http_snowolf.iteye.com_blog_379860]这篇文章列举了很多，但是基本都是j2se平台的，android平台不一定支持，但是AES算法Android是自带了包的，从官方的http://developer.android.com/reference/javax/crypto/Cipher.html可以看到。  
）

AES加密算法是什么？大家可以自己去google，专家级程序员写好包，工程人员会用就行了。

这个例子其实是来自[http://www.tutorials-android.com/learn/How\_to\_encrypt\_and\_decrypt\_strings.rhtml][http_www.tutorials-android.com_learn_How_to_encrypt_and_decrypt_strings.rhtml]。

src目录主文件：

**\[java\]**  [view plain][]  [copy][view plain]

1.  **package** com.qq;  
2.  **import** java.security.SecureRandom;  
3.    
4.  **import** javax.crypto.Cipher;  
5.  **import** javax.crypto.KeyGenerator;  
6.  **import** javax.crypto.SecretKey;  
7.  **import** javax.crypto.spec.SecretKeySpec;  
8.    
9.  **import** android.app.Activity;  
10. **import** android.os.Bundle;  
11. **import** android.util.Log;  
12.   
13. **public** **class** SimpleCrypto **extends** Activity \{  
14.      **public** **static** String encrypt(String seed, String cleartext) **throws** Exception \{      
15.             **byte**\[\] rawKey = getRawKey(seed.getBytes());      
16.             **byte**\[\] result = encrypt(rawKey, cleartext.getBytes());      
17.             **return** toHex(result);      
18.         \}      
19.               
20.         **public** **static** String decrypt(String seed, String encrypted) **throws** Exception \{      
21.             **byte**\[\] rawKey = getRawKey(seed.getBytes());      
22.             **byte**\[\] enc = toByte(encrypted);      
23.             **byte**\[\] result = decrypt(rawKey, enc);      
24.             **return** **new** String(result);      
25.         \}      
26.          
27.         **private** **static** **byte**\[\] getRawKey(**byte**\[\] seed) **throws** Exception \{      
28.             KeyGenerator kgen = KeyGenerator.getInstance("AES");      
29.             SecureRandom sr = SecureRandom.getInstance("SHA1PRNG");      
30.             sr.setSeed(seed);      
31.             kgen.init(128, sr); // 192 and 256 bits may not be available      
32.             SecretKey skey = kgen.generateKey();      
33.             **byte**\[\] raw = skey.getEncoded();      
34.             **return** raw;      
35.         \}      
36.          
37.               
38.         **private** **static** **byte**\[\] encrypt(**byte**\[\] raw, **byte**\[\] clear) **throws** Exception \{      
39.             SecretKeySpec skeySpec = **new** SecretKeySpec(raw, "AES");      
40.             Cipher cipher = Cipher.getInstance("AES");      
41.             cipher.init(Cipher.ENCRYPT\_MODE, skeySpec);      
42.             **byte**\[\] encrypted = cipher.doFinal(clear);      
43.             **return** encrypted;      
44.         \}      
45.          
46.         **private** **static** **byte**\[\] decrypt(**byte**\[\] raw, **byte**\[\] encrypted) **throws** Exception \{      
47.             SecretKeySpec skeySpec = **new** SecretKeySpec(raw, "AES");      
48.             Cipher cipher = Cipher.getInstance("AES");      
49.             cipher.init(Cipher.DECRYPT\_MODE, skeySpec);      
50.             **byte**\[\] decrypted = cipher.doFinal(encrypted);      
51.             **return** decrypted;      
52.         \}      
53.          
54.         **public** **static** String toHex(String txt) \{      
55.             **return** toHex(txt.getBytes());      
56.         \}      
57.         **public** **static** String fromHex(String hex) \{      
58.             **return** **new** String(toByte(hex));      
59.         \}      
60.               
61.         **public** **static** **byte**\[\] toByte(String hexString) \{      
62.             **int** len = hexString.length()/2;      
63.             **byte**\[\] result = **new** **byte**\[len\];      
64.             **for** (**int** i = 0; i < len; i++)      
65.                 result\[i\] = Integer.valueOf(hexString.substring(2\*i, 2\*i+2), 16).byteValue();      
66.             **return** result;      
67.         \}      
68.          
69.         **public** **static** String toHex(**byte**\[\] buf) \{      
70.             **if** (buf == **null**)      
71.                 **return** "";      
72.             StringBuffer result = **new** StringBuffer(2\*buf.length);      
73.             **for** (**int** i = 0; i < buf.length; i++) \{      
74.                 appendHex(result, buf\[i\]);      
75.             \}      
76.             **return** result.toString();      
77.         \}      
78.         **private** **final** **static** String HEX = "0123456789ABCDEF";      
79.         **private** **static** **void** appendHex(StringBuffer sb, **byte** b) \{      
80.             sb.append(HEX.charAt((b>>4)&0x0f)).append(HEX.charAt(b&0x0f));      
81.         \}   
82.     /\*\* Called when the activity is first created. \*/  
83.     @Override  
84.     **public** **void** onCreate(Bundle savedInstanceState) \{  
85.         **super**.onCreate(savedInstanceState);  
86.         setContentView(R.layout.main);  
87.         String masterPassword = "a";  
88.         String originalText = "0123456789";  
89.         **byte**\[\] text = **new** **byte**\[\]\{ '0','1','2','3','4','5','6','7','8','9'\};  
90.         **byte**\[\] password = **new** **byte**\[\]\{ 'a'\};  
91.         **try** \{  
92.             String encryptingCode = SimpleCrypto.encrypt(masterPassword,originalText);  
93. //          System.out.println("加密结果为 " + encryptingCode);  
94.             Log.i("加密结果为 ",encryptingCode);  
95.             String decryptingCode = SimpleCrypto.decrypt(masterPassword, encryptingCode);  
96.             System.out.println("解密结果为 " + decryptingCode);  
97.             Log.i("解密结果",decryptingCode);  
98.            \} **catch** (Exception e) \{  
99.             // TODO Auto-generated catch block  
100.             e.printStackTrace();  
101.     \}  
102.     \}  
103. \}

布局文件main.xml和配置文件AndroidManifest.xml默认就好了。最后结果在Log里面看，利用adb logcat > d:\\1.txt定位到D盘的1.txt文件，然后用记事本打开就，查找”加密结果为“就可以看到了：

运行结果（从log日志中看到的）：

I/加密结果为 (  190): BFB77D8F1E1EE9D5E252926A12659DE8

I/解密结果(  190): 0123456789

转载地址：[http://blog.csdn.net/randyjiawenjie/article/details/6587986][http_blog.csdn.net_randyjiawenjie_article_details_6587986]

[http_snowolf.iteye.com_blog_379860]: http://snowolf.iteye.com/blog/379860
[http_www.tutorials-android.com_learn_How_to_encrypt_and_decrypt_strings.rhtml]: http://www.tutorials-android.com/learn/How_to_encrypt_and_decrypt_strings.rhtml
[view plain]: http://blog.csdn.net/randyjiawenjie/article/details/6587986#
[http_blog.csdn.net_randyjiawenjie_article_details_6587986]: http://blog.csdn.net/randyjiawenjie/article/details/6587986