assertNotNull(mac4);
        assertEquals(16, mac4.length);
    }

    /**
     * Test method for
     * {@link jcifs.pac.PacMac#calculateMacHMACAES(int, javax.security.auth.kerberos.KerberosKey, byte[])}.
     *
     * @throws GeneralSecurityException
     */
    @Test
    void testCalculateMacHMACAES() throws GeneralSecurityException {

     * @return the calculated MAC bytes (truncated to 12 bytes)
     * @throws GeneralSecurityException if cryptographic operations fail
     */
    public static byte[] calculateMacHMACAES(int usage, KerberosKey baseKey, byte[] input) throws GeneralSecurityException {
        byte[] cst = { (byte) (usage >> 24 & 0xFF), (byte) (usage >> 16 & 0xFF), (byte) (usage >> 8 & 0xFF), (byte) (usage & 0xFF),