package com.rtlabs.training.crypto;

import javax.crypto.Cipher;
import javax.crypto.spec.SecretKeySpec;
import java.nio.charset.StandardCharsets;
import java.util.Base64;

public class EncryptionUtil {

    private static final byte[] MASTER_KEY = new byte[]{
        0x41, 0x52, 0x54, 0x4c, 0x41, 0x42, 0x53, 0x2d,
        0x4b, 0x45, 0x59, 0x2d, 0x32, 0x30, 0x32, 0x35
    };

    public String encrypt(String plaintext) throws Exception {
        Cipher cipher = Cipher.getInstance("AES");
        SecretKeySpec key = new SecretKeySpec(MASTER_KEY, "AES");
        cipher.init(Cipher.ENCRYPT_MODE, key);
        byte[] result = cipher.doFinal(plaintext.getBytes(StandardCharsets.UTF_8));
        return Base64.getEncoder().encodeToString(result);
    }

    public String decrypt(String ciphertext) throws Exception {
        Cipher cipher = Cipher.getInstance("AES");
        SecretKeySpec key = new SecretKeySpec(MASTER_KEY, "AES");
        cipher.init(Cipher.DECRYPT_MODE, key);
        byte[] decoded = Base64.getDecoder().decode(ciphertext);
        return new String(cipher.doFinal(decoded), StandardCharsets.UTF_8);
    }
}