4krxamet

1import java.io.*;
2import java.security.*;
3import java.util.Scanner;
4import javax.crypto.*;
5import javax.crypto.spec.IvParameterSpec;
6
7public class AES2 {
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-CTR.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/CTR/NoPadding");
24			aes.init(Cipher.ENCRYPT_MODE, secretKey, new IvParameterSpec(new byte[16]));
25
26			// cipher message
27			byte[] plainText;
28			System.out.println("Give me message which you want encrypt: ");
29			Scanner sc = new Scanner(System.in);
30			plainText = sc.nextLine().getBytes();
31
32			// byte[] plainText = "hello".getBytes();
33
34			out.println("Message : " + new String(plainText));
35
36			// Encrypt message
37			startTime = System.nanoTime();
38			byte[] textEncrypted = aes.doFinal(plainText);
39			endsTime1 = System.nanoTime() - startTime;
40			out.println("Message encryted: " + textEncrypted);
41
42			// Initialize the same cipher for decryption
43			aes.init(Cipher.DECRYPT_MODE, secretKey, new IvParameterSpec(new byte[16]));
44
45			// Decrypt message
46			startTime = System.nanoTime();
47			byte[] textDecrypted = aes.doFinal(textEncrypted);
48			endsTime2 = System.nanoTime() - startTime;
49			out.println("Message decryted: " + new String(textDecrypted));
50
51			out.println("Encryption: " + endsTime1 + " ns");
52			out.println("Decryption: " + endsTime2 + " ns");
53			out.println();
54			System.setOut(out);
55			out.close();
56
57		} catch (NoSuchAlgorithmException e) {
58			e.printStackTrace();
59		} catch (NoSuchPaddingException e) {
60			e.printStackTrace();
61		} catch (InvalidKeyException e) {
62			e.printStackTrace();
63		} catch (IllegalBlockSizeException e) {
64			e.printStackTrace();
65		} catch (BadPaddingException e) {
66			e.printStackTrace();
67		} catch (FileNotFoundException e) {
68			e.printStackTrace();
69		} catch (InvalidAlgorithmParameterException e) {
70			// TODO Auto-generated catch block
71			e.printStackTrace();
72		}
73	}
74
75}