Java : My system for decrypt text doesn't work

El Donaldo :

I've a system for encrypt texts, but i've tried to create a system for decrypt texts, and it doesn't work. The system is :

• initialize encrypted text to byte[]

• initialize decrypted text with the encrypted text

He just return the encrypted text, but not the decrypted text. Have you an idea for debug this?

Thanks in advance.

byte[] getEncrypt(String text) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException
{
    String key = "Bép12345Taruy'(";

    Key aesKey = new SecretKeySpec(key.getBytes(), "AES");
    Cipher cipher = Cipher.getInstance("AES");

    cipher.init(Cipher.ENCRYPT_MODE, aesKey);
    byte[] encrypted = cipher.doFinal(text.getBytes());

    return encrypted;
}

String getDecrypt(String text) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException
{
    String key = "Bép12345Taruy'(";

    Key aesKey = new SecretKeySpec(key.getBytes(), "AES");
    Cipher cipher = Cipher.getInstance("AES");

    cipher.init(Cipher.ENCRYPT_MODE, aesKey);
    byte[] encrypted = cipher.doFinal(text.getBytes());

    cipher.init(Cipher.DECRYPT_MODE, aesKey);
    String decrypted = new String(cipher.doFinal(encrypted));

    return decrypted;
}

heiwil :

You encrypt the encrypted text in your getDecrypt(...) method. Or do you want to encrypt and decript it again in one method?

One solution would be following code:

package test;

import java.security.InvalidKeyException;
import java.security.Key;
import java.security.NoSuchAlgorithmException;

import javax.crypto.BadPaddingException;
import javax.crypto.Cipher;
import javax.crypto.IllegalBlockSizeException;
import javax.crypto.NoSuchPaddingException;
import javax.crypto.spec.SecretKeySpec;

public class Test2{        

    public static void main(String[] args) throws InvalidKeyException, NoSuchPaddingException, NoSuchAlgorithmException, BadPaddingException, IllegalBlockSizeException {
        System.out.println(new String(getEncrypt("test")));
        System.out.println(new String(getDecrypt(getEncrypt("test"))));

    }

    public static byte[] getEncrypt(String text) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
        String key = "Bép12345Taruy'(";

        Key aesKey = new SecretKeySpec(key.getBytes(), "AES");
        Cipher cipher = Cipher.getInstance("AES");

        cipher.init(Cipher.ENCRYPT_MODE, aesKey);
        byte[] encrypted = cipher.doFinal(text.getBytes());

        return encrypted;
    }

    public static byte [] getDecrypt(byte[] encrypted) throws NoSuchPaddingException, NoSuchAlgorithmException, InvalidKeyException, BadPaddingException, IllegalBlockSizeException {
        String key = "Bép12345Taruy'(";

        Key aesKey = new SecretKeySpec(key.getBytes(), "AES");
        Cipher cipher = Cipher.getInstance("AES");

        cipher.init(Cipher.DECRYPT_MODE, aesKey);
        return cipher.doFinal(encrypted);
    }

}

Output:

�'���+~�@��@w

test