assertEquals("abc", StringUtil.substringToLast("abc", "dddd"));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testToHex() throws Exception {
        assertEquals("010203", StringUtil.toHex(new byte[] { 1, 2, 3 }));
    }

    /**
     * @throws Exception
     */
    @Test
    public void testToHex2() throws Exception {
        assertEquals("0001", StringUtil.toHex(1));

    /**
     * Flag indicating that SIDs should be resolved to names.
     */
    public static final int SID_FLAG_RESOLVE_SIDS = 0x0001;

    /**
     * Well known SID: EVERYONE
     */
    public static SID EVERYONE = null;

    /**
     * Well known SID: CREATOR_OWNER
     */
    public static SID CREATOR_OWNER = null;

    /**

        Field commandField = ServerMessageBlock2.class.getDeclaredField("command");
        commandField.setAccessible(true);
        int command = (int) commandField.get(req);
        assertEquals(0x0001, command); // SMB2_SESSION_SETUP command value

        Field securityModeField = Smb2SessionSetupRequest.class.getDeclaredField("securityMode");
        securityModeField.setAccessible(true);

        // Bit 2: active (1)
        // Bit 1: permanent (1)

        // MAC address
        byte[] testMac = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
        System.arraycopy(testMac, 0, src, srcIndex + 19, 6);

        // Statistics
        byte[] stats = { 0x00, 0x00, 0x00, 0x00, 0x00, 0x00 };
        System.arraycopy(stats, 0, src, srcIndex + 25, 6);

        response.readRDataWireFormat(src, srcIndex);

        assertNotNull(signingKey, "Should handle large session key");
        assertEquals(16, signingKey.length, "Should still produce 16-byte key");
    }

    @ParameterizedTest
    @ValueSource(ints = { 0x0300, 0x0302, 0x0310 }) // Non-3.1.1 dialects
    @DisplayName("Should use SMB 3.0.x context for non-3.1.1 dialects")
    void testDeriveKeys_NonSMB311Dialects(int dialect) {
        // When

    @ParameterizedTest
    @CsvSource({ "4, 257", // FILE_BASIC_INFO -> 0x0101
            "5, 258", // FILE_STANDARD_INFO -> 0x0102
            "20, 260" // FILE_ENDOFFILE_INFO -> 0x0104
    })
    void testWithDifferentInformationLevels(byte infoLevel, int expectedMappedValue) {
        when(mockFileInfo.getFileInformationLevel()).thenReturn(infoLevel);

        assertEquals(expectedHigh, buffer[offset + 3]);
    }

    private static Stream<Arguments> provideFidTestCases() {
        return Stream.of(Arguments.of(0x0000, (byte) 0x00, (byte) 0x00), Arguments.of(0x00FF, (byte) 0xFF, (byte) 0x00),
                Arguments.of(0xFF00, (byte) 0x00, (byte) 0xFF), Arguments.of(0xFFFF, (byte) 0xFF, (byte) 0xFF),
                Arguments.of(0x1234, (byte) 0x34, (byte) 0x12));
    }

    @Test

        // recordType (2 bytes)
        src[srcIndex + 2] = 0x00;
        src[srcIndex + 3] = 0x20; // NB (0x0020)
        // recordClass (2 bytes)
        src[srcIndex + 4] = 0x00;
        src[srcIndex + 5] = 0x01; // IN (0x0001)
        // ttl (4 bytes)
        src[srcIndex + 6] = 0x00;
        src[srcIndex + 7] = 0x00;
        src[srcIndex + 8] = 0x00;
        src[srcIndex + 9] = 0x00;
        // rDataLength (2 bytes)

        byte[] data1 = { 0x00, 0x01, 0x02, 0x03 };
        assertEquals("00", Hexdump.toHexString(data1, 0, 2)); // 2 chars = 1 byte
        assertEquals("000", Hexdump.toHexString(data1, 0, 3)); // 3 chars = 1.5 bytes (rounds up to 2)
        assertEquals("0001", Hexdump.toHexString(data1, 0, 4)); // 4 chars = 2 bytes
        assertEquals("000102", Hexdump.toHexString(data1, 0, 6)); // 6 chars = 3 bytes

    /** SMB2 create/open file command */
    protected static final short SMB2_CREATE = 0x0005;
    /** SMB2 close file command */
    protected static final short SMB2_CLOSE = 0x0006;
    /** SMB2 flush file command */
    protected static final short SMB2_FLUSH = 0x0007;
    /** SMB2 read file command */
    protected static final short SMB2_READ = 0x0008;
    /** SMB2 write file command */