zaWXNWa5

1package mkri;
2
3import java.security.InvalidAlgorithmParameterException;
4import java.security.InvalidKeyException;
5import java.security.NoSuchAlgorithmException;
6import java.security.SecureRandom;
7import java.security.spec.AlgorithmParameterSpec;
8
9import javax.crypto.BadPaddingException;
10import javax.crypto.Cipher;
11import javax.crypto.IllegalBlockSizeException;
12import javax.crypto.KeyGenerator;
13import javax.crypto.NoSuchPaddingException;
14import javax.crypto.SecretKey;
15import javax.crypto.spec.IvParameterSpec;
16import javax.crypto.spec.SecretKeySpec;
17
18public class Encryption {
19	
20	private byte[] IV;
21	public byte[] encrypt(byte[] data, byte[] bKey) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException {
22		
23		//--------------------- vytvoreni random IV --------------------------------------- (6)
24
25
26		int ivSize = 16;
27        IV = new byte[ivSize];
28        SecureRandom random = new SecureRandom();
29        random.nextBytes(IV);
30        IvParameterSpec ivParameterSpec = new IvParameterSpec(IV);
31		
32		
33		
34		//--------------------- vytvoreni random IV --------------------------------------- 
35		byte[] bEnc = null;
36		
37		// --------------------- vytvorit instanci třídy Cipher, inicializovat a použít --- (4)
38		
39
40		SecretKey originalKey = new SecretKeySpec(bKey, 0, bKey.length, "AES");
41		
42		Cipher c = 	Cipher.getInstance("AES/CBC/PKCS5Padding");
43		
44		c.init(Cipher.ENCRYPT_MODE, originalKey, ivParameterSpec);
45
46		bEnc = c.doFinal(data);
47		// --------------------- vytvorit instanci třídy Cipher, inicializovat a použít --- 
48		return bEnc;
49		
50	}
51	
52	public byte[] decrypt(byte[] data, byte[] bKey) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, InvalidAlgorithmParameterException, IllegalBlockSizeException, BadPaddingException {
53		
54		byte[] bDec = null;
55		// --------------------- vytvorit instanci třídy Cipher, inicializovat a použít --- (5)
56
57		int ivSize = 16;
58        IV = new byte[ivSize];
59		
60		System.arraycopy(data, 0, IV, 0, IV.length);
61		IvParameterSpec ivParameterSpec = new IvParameterSpec(IV);
62		
63		SecretKey originalKey = new SecretKeySpec(bKey, 0, bKey.length, "AES");
64		
65		Cipher c = 	Cipher.getInstance("AES/CBC/PKCS5Padding");
66		//c.init(Cipher.ENCRYPT_MODE, key);
67		c.init(Cipher.DECRYPT_MODE, originalKey, ivParameterSpec);
68		
69		bDec = c.doFinal(data);
70		
71		
72		// --------------------- vytvorit instanci třídy Cipher, inicializovat a použít --- 
73		return bDec;
74		
75	}
76
77}