Decrypt Base64 Encryption using Java

Decrypt Base64 Encryption

import java.security.GeneralSecurityException;
import javax.crypto.Cipher;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import javax.xml.bind.DatatypeConverter;
import java.util.Base64;

public class Base64Decryptor {
    private static byte[] des_cbc_decrypt(
            byte[] encrypted_password,
            byte[] decryption_key,
            byte[] iv)
            throws GeneralSecurityException {

        Cipher cipher = Cipher.getInstance("DES/CBC/PKCS5Padding");
        cipher.init(Cipher.DECRYPT_MODE, new SecretKeySpec(decryption_key, "DES"), new IvParameterSpec(iv));
        return cipher.doFinal(encrypted_password);
    }

    private static byte[] decrypt_v4(
            byte[] encrypted,
            byte[] db_system_id)
            throws GeneralSecurityException {
        byte[] encrypted_password = Base64.getDecoder().decode(encrypted);
        byte[] salt = DatatypeConverter.parseHexBinary("051399429372e8ad");

// key = db_system_id + salt
        byte[] key = new byte[db_system_id.length + salt.length];
        System.arraycopy(db_system_id, 0, key, 0, db_system_id.length);
        System.arraycopy(salt, 0, key, db_system_id.length, salt.length);

        java.security.MessageDigest md = java.security.MessageDigest.getInstance("MD5");
        for (int i = 0; i < 42; i++) {
            key = md.digest(key);
        }

// secret_key = key [0..7]
        byte[] secret_key = new byte[8];
        System.arraycopy(key, 0, secret_key, 0, 8);

// iv = key [8..]
        byte[] iv = new byte[key.length - 8];
        System.arraycopy(key, 8, iv, 0, key.length - 8);

        return des_cbc_decrypt(encrypted_password, secret_key, iv);
    }

    public static void main(String[] argv) {
        try {

            byte[] encrypted = argv[0].getBytes();
            byte[] db_system_id = argv[1].getBytes();

            byte[] x = decrypt_v4(encrypted, db_system_id);

            String password = new String(x);

            System.out.println(password);
        } catch (Exception e) {
            System.out.println(e.toString());
        }
    }
}