8XtJW92g

1import java.io.*;
2import java.security.*;
3import java.util.Scanner;
4import javax.crypto.*;
5
6
7public class AES {
8	public static void main(String[] argv) throws FileNotFoundException {
9		long startTime = System.nanoTime();
10		long endsTime1 = System.nanoTime() - startTime;
11		long endsTime2 = System.nanoTime() - startTime;
12		SecureRandom rand = new SecureRandom();
13
14		try {
15			// PrintStream out = new PrintStream(new FileOutputStream("AES-ECB.txt", true));
16			PrintStream out = System.out;
17
18			KeyGenerator keyGen = KeyGenerator.getInstance("AES");
19			keyGen.init(128, rand);
20			SecretKey secretKey = keyGen.generateKey();
21
22			Cipher aes;
23			aes = Cipher.getInstance("AES/ECB/PKCS5Padding");
24			aes.init(Cipher.ENCRYPT_MODE, secretKey);
25
26			// cipher message
27			byte[] crypted = null;
28			System.out.println("Give me message which you want encrypt: ");
29			Scanner sc = new Scanner(System.in);
30			String input = sc.nextLine();
31//			byte[] plainText = "tomek".getBytes();
32
33			out.println("Message : " + new String(input.getBytes()));
34
35			// Encrypt message
36			startTime = System.nanoTime();
37			crypted = aes.doFinal(input.getBytes());
38			endsTime1 = System.nanoTime() - startTime;
39			
40			java.util.Base64.Encoder encoder = java.util.Base64.getEncoder();
41			out.println("Message encryted: " + new String(encoder.encodeToString(crypted)));
42			
43			// Initialize the same cipher for decryption
44			aes.init(Cipher.DECRYPT_MODE, secretKey);
45
46			// Decrypt message
47			startTime = System.nanoTime();
48			byte[] textDecrypted = aes.doFinal(crypted);
49			endsTime2 = System.nanoTime() - startTime;
50			out.println("Message decryted: " + new String(textDecrypted));
51
52			out.println("Encryption: " + endsTime1 + " ns");
53			out.println("Decryption: " + endsTime2 + " ns");
54			out.println();
55			System.setOut(out);
56			out.close();
57
58		} catch (NoSuchAlgorithmException e) {
59			e.printStackTrace();
60		} catch (NoSuchPaddingException e) {
61			e.printStackTrace();
62		} catch (InvalidKeyException e) {
63			e.printStackTrace();
64		} catch (IllegalBlockSizeException e) {
65			e.printStackTrace();
66		} catch (BadPaddingException e) {
67			e.printStackTrace();
68			// } catch (FileNotFoundException e) {
69			// e.printStackTrace();
70		}
71	}
72
73}