}
        engineReset();
    }

    private HMACT64(final HMACT64 hmac) throws CloneNotSupportedException {
        super("HMACT64");
        this.ipad = hmac.ipad;
        this.opad = hmac.opad;
        this.md5 = (MessageDigest) hmac.md5.clone();
    }

    @Override
    public Object clone() {
        try {
            return new HMACT64(this);
        } catch (final CloneNotSupportedException ex) {

        engineReset();
    }

    private HMACT64(final HMACT64 hmac) throws CloneNotSupportedException {
        super("HMACT64");
        this.ipad = hmac.ipad;
        this.opad = hmac.opad;
        this.md5 = (MessageDigest) hmac.md5.clone();
    }

    @Override
    public Object clone() {
        try {
            return new HMACT64(this);
        } catch (final CloneNotSupportedException ex) {

        // Test constructor with a normal length key
        HMACT64 hmac = new HMACT64(TEST_KEY);
        assertNotNull(hmac);
    }

    @Test
    void testConstructorWithLongKey() {
        // Test constructor with a key longer than BLOCK_LENGTH (64 bytes)
        // HMACT64 truncates keys at 64 bytes
        HMACT64 hmac = new HMACT64(LONG_TEST_KEY);
        assertNotNull(hmac);
    }

    @Test

            mockedCrypto.when(Crypto::getMD5).thenReturn(mockMd5);
            HMACT64 originalHmac = new HMACT64(TEST_KEY);

            // Mock the clone behavior of the internal MessageDigest
            MessageDigest clonedMd5 = mock(MessageDigest.class);
            when(mockMd5.clone()).thenReturn(clonedMd5);

            HMACT64 clonedHmac = (HMACT64) originalHmac.clone();

            assertNotNull(clonedHmac);

            throw new CIFSUnsupportedCryptoException(e);
        }
    }

    /**
     * Get an HMACT64 message authentication code instance.
     * @param key the key for the HMACT64 MAC
     * @return HMACT64 MAC instance
     */
    public static MessageDigest getHMACT64(final byte[] key) {
        return new HMACT64(key);
    }

    /**
     * Get an RC4 cipher instance initialized with the specified key.

            md4.update(password.getBytes(SmbConstants.UNI_ENCODING));
            HMACT64 hmac = new HMACT64(md4.digest());
            hmac.update(user.toUpperCase().getBytes(SmbConstants.UNI_ENCODING));
            hmac.update(domain.toUpperCase().getBytes(SmbConstants.UNI_ENCODING));
            hmac = new HMACT64(hmac.digest());
            hmac.update(challenge);
            hmac.update(clientChallenge);

                    final MD4 md4 = new MD4();
                    md4.update(responseKeyNT);
                    final byte[] userSessionKey = md4.digest();

                    final HMACT64 hmac = new HMACT64(userSessionKey);
                    hmac.update(sessionNonce);
                    final byte[] ntlm2SessionKey = hmac.digest();

                    if ((getFlags() & NTLMSSP_NEGOTIATE_KEY_EXCH) != 0) {