J85TQi6Z

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, IllegalBlockSizeException, BadPaddingException, InvalidAlgorithmParameterException {
22		
23		//--------------------- vytvoreni random IV --------------------------------------- (6)
24		this.IV = new byte[16];
25		SecureRandom sRND = new SecureRandom();
26		sRND.nextBytes(IV);
27		IvParameterSpec ivspec = new IvParameterSpec(IV);
28		//--------------------- vytvoreni random IV --------------------------------------- 
29		byte[] bEnc = null;
30		
31		// --------------------- vytvorit instanci třídy Cipher, inicializovat a použít --- (4)
32		SecretKey key = new SecretKeySpec(bKey, 0,bKey.length, "AES");
33		Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
34        cipher.init(Cipher.ENCRYPT_MODE, key, ivspec);
35        bEnc = cipher.doFinal(data);
36		
37		// --------------------- vytvorit instanci třídy Cipher, inicializovat a použít --- 
38		return bEnc;
39		
40	}
41	
42	public byte[] decrypt(byte[] data, byte[] bKey) throws NoSuchAlgorithmException, NoSuchPaddingException, InvalidKeyException, IllegalBlockSizeException, BadPaddingException, InvalidAlgorithmParameterException {
43		byte[] bDec = null;
44		//SecureRandom sRND = new SecureRandom();
45		
46		//this.IV = new byte[16];
47		//System.arraycopy(data, 0, IV, 0, IV.length);		
48		//sRND.nextBytes(IV);
49		IvParameterSpec ivspec = new IvParameterSpec(IV);
50		
51		// --------------------- vytvorit instanci třídy Cipher, inicializovat a použít --- (5)
52		SecretKey key = new SecretKeySpec(bKey, 0,bKey.length, "AES");
53		Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
54        cipher.init(Cipher.DECRYPT_MODE, key, ivspec);
55       
56        
57        
58        bDec = cipher.doFinal(data);
59		// --------------------- vytvorit instanci třídy Cipher, inicializovat a použít --- 
60		return bDec;
61		
62	}
63
64}