Encrypt in java and Decrypt in C# For AES 256 bit

Question

1.I have java function which encrypt xml file and return encrypted String.

/// Java Class 
import java.security.Key;
import javax.crypto.Cipher;
import javax         


        

Answer 1

I had a problem with this algorithm (in Java only) and I did a litle changes.

Diff Image

// Java code - Cipher mode CBC version.
// CBC version need Initialization vector IV.
// Reference from https://stackoverflow.com/questions/6669181/why-does-my-aes-encryption-throws-an-invalidkeyexception/6669812#6669812
public static String key = "FFClY170hLrhsDnKUEhJ4FhVOnrpNNFFClY170hLrhsDnKUE";
public static byte[] key_Array = Base64.decodeBase64(key);

public static String encrypt(String strToEncrypt) {
    try {
        //Cipher _Cipher = Cipher.getInstance("AES");
        //Cipher _Cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
        Cipher _Cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");

        // Initialization vector.   
        // It could be any value or generated using a random number generator.
        byte[] iv = {1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1, 7, 7, 7, 7};
        IvParameterSpec ivspec = new IvParameterSpec(iv);

        key_Array = Arrays.copyOf(key_Array, 32);

        Key SecretKey = new SecretKeySpec(key_Array, "AES");
        _Cipher.init(Cipher.ENCRYPT_MODE, SecretKey, ivspec);

        return Base64.encodeBase64String(_Cipher.doFinal(strToEncrypt.getBytes()));
    } catch (Exception e) {
        System.out.println("[Exception]:" + e.getMessage());
    }
    return null;
}

public static String decrypt(String EncryptedMessage) {
    try {
        //Cipher _Cipher = Cipher.getInstance("AES");
        //Cipher _Cipher = Cipher.getInstance("AES/ECB/PKCS5PADDING");
        Cipher _Cipher = Cipher.getInstance("AES/CBC/PKCS5PADDING");

        // Initialization vector.   
        // It could be any value or generated using a random number generator.
        byte[] iv = {1, 2, 3, 4, 5, 6, 6, 5, 4, 3, 2, 1, 7, 7, 7, 7};
        IvParameterSpec ivspec = new IvParameterSpec(iv);

        key_Array = Arrays.copyOf(key_Array, 32);

        Key SecretKey = new SecretKeySpec(key_Array, "AES");
        _Cipher.init(Cipher.DECRYPT_MODE, SecretKey, ivspec);

        byte DecodedMessage[] = Base64.decodeBase64(EncryptedMessage);
        return new String(_Cipher.doFinal(DecodedMessage));

    } catch (Exception e) {
        System.out.println("[Exception]:" + e.getMessage());

    }
    return null;
}