Y85RWhWx

1package lv.org.substance.crypt
2
3import java.security.spec.AlgorithmParameterSpec;
4import java.security.spec.KeySpec;
5
6import javax.crypto.Cipher;
7import javax.crypto.SecretKey;
8import javax.crypto.SecretKeyFactory;
9import javax.crypto.spec.PBEKeySpec;
10import javax.crypto.spec.PBEParameterSpec;
11
12import org.apache.commons.codec.binary.Base64;
13
14public class EncryptionUtil
15{
16  // some random salt
17  private static final byte[]	SALT			= { (byte) 0x21, (byte) 0x21, (byte) 0xF0, (byte) 0x55, (byte) 0xC3, (byte) 0x9F, (byte) 0x5A, (byte) 0x75						};
18
19	private final static int	ITERATION_COUNT	= 31;
20
21	private EncryptionUtil()
22	{
23	}
24
25	public static String encode(String input)
26	{
27		if (input == null)
28		{
29			throw new IllegalArgumentException();
30		}
31		try
32		{
33
34			KeySpec keySpec = new PBEKeySpec(null, SALT, ITERATION_COUNT);
35			AlgorithmParameterSpec paramSpec = new PBEParameterSpec(SALT, ITERATION_COUNT);
36
37			SecretKey key = SecretKeyFactory.getInstance("PBEWithMD5AndDES").generateSecret(keySpec);
38
39			Cipher ecipher = Cipher.getInstance(key.getAlgorithm());
40			ecipher.init(Cipher.ENCRYPT_MODE, key, paramSpec);
41
42			byte[] enc = ecipher.doFinal(input.getBytes());
43
44			String res = new String(Base64.encodeBase64(enc));
45			// escapes for url
46			res = res.replace('+', '-').replace('/', '_').replace("%", "%25").replace("\n", "%0A");
47
48			return res;
49
50		}
51		catch (Exception e)
52		{
53		}
54
55		return "";
56
57	}
58
59	public static String decode(String token)
60	{
61		if (token == null)
62		{
63			return null;
64		}
65		try
66		{
67
68			String input = token.replace("%0A", "\n").replace("%25", "%").replace('_', '/').replace('-', '+');
69
70			byte[] dec = Base64.decodeBase64(input.getBytes());
71
72			KeySpec keySpec = new PBEKeySpec(null, SALT, ITERATION_COUNT);
73			AlgorithmParameterSpec paramSpec = new PBEParameterSpec(SALT, ITERATION_COUNT);
74
75			SecretKey key = SecretKeyFactory.getInstance("PBEWithMD5AndDES").generateSecret(keySpec);
76
77			Cipher dcipher = Cipher.getInstance(key.getAlgorithm());
78			dcipher.init(Cipher.DECRYPT_MODE, key, paramSpec);
79
80			byte[] decoded = dcipher.doFinal(dec);
81
82			String result = new String(decoded);
83			return result;
84
85		}
86		catch (Exception e)
87		{
88      // use logger in production code
89			e.printStackTrace();
90		}
91
92		return null;
93	}
94
95}