之前有人问过hibernate密码问题，大家都没有给出一个具体的解决方案，所以我就看了一下代码，把我的想法和实现拿出来和大家讨论一下。我现在的环境是spring+hibernate，但是这并不影响这个加密解密的问题，其他环境应该是略有不同，但是思路肯定是一样的。
1
public class DESUtil ...{
2
3
public static void main(String[] args)...{
4 try ...{
5 if(args[0].equals("-genKey"))...{
6 generateKey(args[1]);
7 }else...{
8
9 //if (args[0].equals("-encrypt"))encrypt();
10
11 //else decrypt();
12
}
13 }catch (Exception e) ...{
14 // TODO: handle exception
15 }
16 }
17
18 public static String encrypt(String plainText, String encryptString, File keyFile)throws IOException, ClassNotFoundException,GeneralSecurityException...{
19 ObjectInputStream keyIn = new ObjectInputStream(new FileInputStream(keyFile));
20 int mode = Cipher.ENCRYPT_MODE;
21 Key key = (Key)keyIn.readObject();
22 keyIn.close();
23
24 InputStream in = new FileInputStream(plainText);
25 OutputStream out = new FileOutputStream(encryptString);
26
27 Cipher cipher = Cipher.getInstance("DES");
28 cipher.init(mode, key);
29
30 doEncryptAndDecrypt(in, out, cipher);
31
32 String result = out.toString();
33 System.out.print(result);
34 in.close();
35 out.close();
36 return result;
37 }
38
39 public static String decrypt(String encryptString, String plainText, File keyFile)throws IOException, ClassNotFoundException,GeneralSecurityException...{
40 ObjectInputStream keyIn = new ObjectInputStream(new FileInputStream(keyFile));
41 int mode = Cipher.DECRYPT_MODE;
42 Key key = (Key)keyIn.readObject();
43 keyIn.close();
44
45 InputStream in = new FileInputStream(encryptString);
46 OutputStream out = new FileOutputStream(plainText);
47
48 Cipher cipher = Cipher.getInstance("DES");
49 cipher.init(mode, key);
50
51 doEncryptAndDecrypt(in, out, cipher);
52
53 String result = out.toString();
54 System.out.print(result);
55 in.close();
56 out.close();
57 return result;
58 }
59
60 public static void doEncryptAndDecrypt(InputStream in, OutputStream out, Cipher cipher)throws IOException, GeneralSecurityException...{
61 int blockSize = cipher.getBlockSize();
62 int outputSize = cipher.getOutputSize(blockSize);
63
64 byte[] inBytes = new byte[blockSize];
65 byte[] outBytes = new byte[outputSize];
66
67 int inLength = 0;
68 boolean more = true;
69
70 while(more)...{
71 inLength = in.read(inBytes);
72 if(inLength == blockSize)...{
73 int outLength = cipher.update(inBytes, 0, blockSize, outBytes);
74 out.write(outBytes,0,outLength);
75 }
76 else more = false;
77 }
78
79 if(inLength>0) outBytes = cipher.doFinal(inBytes, 0, inLength);
80 else outBytes = cipher.doFinal();
81
82 out.write(outBytes);
83
84 }
85
86 public static void generateKey(String path) throws Exception...{
87 KeyGenerator keygen = KeyGenerator.getInstance("DES");
88 SecureRandom random = new SecureRandom();
89
90 keygen.init(random);
91 SecretKey key = keygen.generateKey();
92
93 ObjectOutputStream out = new ObjectOutputStream( new FileOutputStream(path));
94 out.writeObject(key);
95 out.close();
96 }
97
98
}
99
