import java.util.Base64;
import java.security.MessageDigest;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import java.util.HexFormat;

class Main {
    public static byte[] f44153a = {104, 51, 94, 37, 52, 126, 115, 120, 106, 108, 115, 100, 57, 49};

    public static void main(String[] args) {
        System.out.println(encrypt("Try programiz.pro"));
        System.out.println(decrypt("UwwXMPrXT5JGty9VfrHiZ+0aR+nbNg71pnRhmKORxjQ="));
    }
    private static String decrypt(String str) {
        try {
            byte[] keyBytes = MessageDigest.getInstance("MD5").digest(f44153a);
            SecretKeySpec secretKeySpec = new SecretKeySpec(keyBytes, "AES");
            byte[] ivBytes = new byte[]{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
            IvParameterSpec ivParameterSpec = new IvParameterSpec(ivBytes);
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            cipher.init(Cipher.DECRYPT_MODE, secretKeySpec, ivParameterSpec);
            int paddingLength = (4 - (str.length() % 4)) % 4;
            str = str + "=".repeat(paddingLength);
            byte[] decode = Base64.getDecoder().decode(str);
            byte[] decryptedBytes = cipher.doFinal(decode);
            return new String(decryptedBytes);
        } catch (Exception e) {
            e.printStackTrace();
            return null;
        }
    }

    private static String encrypt(String str) {
        try {
            byte[] keyBytes = MessageDigest.getInstance("MD5").digest(f44153a);
            SecretKeySpec secretKeySpec = new SecretKeySpec(keyBytes, "AES");
            byte[] ivBytes = new byte[]{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15};
            IvParameterSpec ivParameterSpec = new IvParameterSpec(ivBytes);
            System.out.println("Key (Hex): " + bytesToHex(keyBytes));
            System.out.println("IV (Hex): " + bytesToHex(ivBytes));
            Cipher cipher = Cipher.getInstance("AES/CBC/PKCS5Padding");
            cipher.init(Cipher.ENCRYPT_MODE, secretKeySpec, ivParameterSpec);
            String base64Encoded = Base64.getEncoder().encodeToString(cipher.doFinal(str.getBytes(), 0, str.getBytes().length));
            int paddingLength = (4 - (base64Encoded.length() % 4)) % 4;
            base64Encoded = base64Encoded + "=".repeat(paddingLength);
            return base64Encoded;
        } catch (Exception e7) {
            e7.printStackTrace();
            return null;
        }
    }
    private static String bytesToHex(byte[] bytes) {
        HexFormat hexFormat = HexFormat.of();
        return hexFormat.formatHex(bytes);
    }
}