atChat/CryptoRSA.java at master · ATryder/atChat · GitHub

1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
package atChat;

import java.security.KeyFactory;
import java.security.KeyPair;
import java.security.KeyPairGenerator;
import java.security.PublicKey;
import java.security.spec.RSAPrivateKeySpec;
import java.security.spec.RSAPublicKeySpec;
import java.security.spec.X509EncodedKeySpec;

import javax.crypto.Cipher;

public class CryptoRSA extends Crypt {
	private final Cipher encryptor;
	private final Cipher decryptor;

	protected final byte[] pubKey;

	protected CryptoRSA() throws Exception {
		KeyPairGenerator kpg = KeyPairGenerator.getInstance("RSA");
		kpg.initialize(2048);
		KeyPair pair = kpg.genKeyPair();

		KeyFactory kFact = KeyFactory.getInstance("RSA");
		RSAPublicKeySpec pubKeySpec = kFact.getKeySpec(pair.getPublic(), RSAPublicKeySpec.class);
		PublicKey pKey = kFact.generatePublic(pubKeySpec);
		pubKey = pair.getPublic().getEncoded();

		encryptor = Cipher.getInstance("RSA");
		encryptor.init(Cipher.ENCRYPT_MODE, pKey);

		decryptor = Cipher.getInstance("RSA");
		decryptor.init(Cipher.DECRYPT_MODE, kFact.generatePrivate(kFact.getKeySpec(pair.getPrivate(), RSAPrivateKeySpec.class)));
	}

	protected CryptoRSA(byte[] pubKey) throws Exception {
		this.pubKey = pubKey;

		KeyFactory kFact = KeyFactory.getInstance("RSA");
		PublicKey pKey = kFact.generatePublic(new X509EncodedKeySpec(pubKey));

		encryptor = Cipher.getInstance("RSA");
		encryptor.init(Cipher.ENCRYPT_MODE, pKey);

		decryptor = null;
	}

	@Override
	protected byte[] encrypt(final String text) {
		try {
			return encryptor.doFinal(text.getBytes());
		} catch (Exception e) {
			return null;
		}
	}

	@Override
	protected byte[] encrypt(final byte[] bytes) {
		try {
			return encryptor.doFinal(bytes);
		} catch (Exception e) {
			return null;
		}
	}

	@Override
	protected String decrypt(final byte[] bytes) {
		if (decryptor != null) {
			try {
				return new String(decryptor.doFinal(bytes));
			} catch (Exception e) {
				return null;
			}
		}
		return null;
	}

	@Override
	protected byte[] decryptBytes(final byte[] bytes) {
		if (decryptor != null) {
			try {
				return decryptor.doFinal(bytes);
			} catch (Exception e) {
				return null;
			}
		}
		return null;
	}
}