@Override
    public void releaseBuffer(final byte[] buf) {
        if (buf == null) {
            return;
        }
        // better safe than sorry: prevent leaks if there is some out of bound access
        Arrays.fill(buf, (byte) 0);
        synchronized (this.cache) {
            if (this.freeBuffers < this.cache.length) {
                for (int i = 0; i < this.cache.length; i++) {
                    if (this.cache[i] == null) {

        SMBUtil.writeInt4(432, buffer, bufferIndex + 4); // 512 - 80

        response = spy(response);
        when(response.getHeaderStart()).thenReturn(0);

        // Fill the entire data area with zero (no valid entries)
        for (int i = dataOffset; i < 512; i++) {
            buffer[i] = 0;
        }

        int result = response.readBytesWireFormat(buffer, bufferIndex);

     */
    public byte[] getBuffer() {
        return buf;
    }

    /**
     * Aligns the buffer index to the specified boundary with a fill value.
     *
     * @param boundary the alignment boundary
     * @param value the fill value for padding
     * @return the number of bytes added for alignment
     */
    public int align(final int boundary, final byte value) {

        if (this.password != null) {
            // Multi-pass secure wipe of password char array
            Arrays.fill(this.password, '\0');
            Arrays.fill(this.password, '\uFFFF');
            Arrays.fill(this.password, '\uAAAA');
            Arrays.fill(this.password, '\u5555');
            Arrays.fill(this.password, '\0');
            this.password = null;
        }

        buffer[bufferIndex] = 0x00;
        buffer[bufferIndex + 1] = 0x00;
        buffer[bufferIndex + 2] = 0x00;
        SMBUtil.writeInt4(1500, buffer, bufferIndex + 3);

        // Fill rest of required fields
        for (int i = 7; i < 37; i++) {
            buffer[bufferIndex + i] = 0x00;
        }

        response.readParameterWordsWireFormat(buffer, bufferIndex);

    void testDeriveKeys_TestVectors() {
        // Given - Use known test vector (simplified for demonstration)
        byte[] testSessionKey = new byte[16];
        Arrays.fill(testSessionKey, (byte) 0xAA);
        byte[] testPreauth = new byte[64];
        Arrays.fill(testPreauth, (byte) 0xBB);

        // When
        byte[] signingKey300 = Smb3KeyDerivation.deriveSigningKey(Smb2Constants.SMB2_DIALECT_0300, testSessionKey, testPreauth);

    void testWithLargeBuffers() {
        // Test with large byte arrays
        byte[] largeRequestBuffer = new byte[1024];
        byte[] largeResponseBuffer = new byte[2048];

        // Fill with some test data
        for (int i = 0; i < largeRequestBuffer.length; i++) {
            largeRequestBuffer[i] = (byte) (i % 256);
        }
        for (int i = 0; i < largeResponseBuffer.length; i++) {

    private static final byte[] TEST_DATA = "testdata".getBytes();
    private static final byte[] EMPTY_DATA = new byte[0];

    static {
        // Initialize long key with predictable data
        Arrays.fill(LONG_TEST_KEY, (byte) 0xAB);
    }

    @Test
    void testConstructorWithNormalKey() {
        // Test constructor with a normal length key
        HMACT64 hmac = new HMACT64(TEST_KEY);
        assertNotNull(hmac);

        @Test
        @DisplayName("Should not modify reserved field bytes")
        void testReservedFieldNotModified() {
            lock = new Smb2Lock(999L, 888L, 0xFF);

            // Fill buffer with non-zero values
            Arrays.fill(buffer, (byte) 0xFF);

            lock.encode(buffer, 0);

            // Reserved field bytes are not modified by the encode method

        byte[] buffer = new byte[100];
        int bufferIndex = 50;

        // Set test values
        int testCapabilities = 0xABCDEF00;
        byte[] testGuid = new byte[16];
        Arrays.fill(testGuid, (byte) 0xFF);
        int testSecurityMode = 0x0001;
        int testDialect = 0x0202;

        // Write to buffer
        SMBUtil.writeInt4(testCapabilities, buffer, bufferIndex);