import java.security.Key;
import java.security.MessageDigest;
import java.util.Arrays;
import java.util.Map;

import javax.crypto.Cipher;
import javax.crypto.Mac;
import javax.crypto.spec.IvParameterSpec;
import javax.crypto.spec.SecretKeySpec;
import javax.security.auth.kerberos.KerberosKey;

/**
 * Utility class for calculating and verifying PAC (Privilege Attribute Certificate) message authentication codes.