final Smb2TransformHeader transformHeader = new Smb2TransformHeader(nonce, message.length, flags, sessionId);
            final byte[] associatedData = transformHeader.getAssociatedData();

            // Perform encryption based on cipher type
            EncryptionResult encResult =

        transformHeader.setOriginalMessageSize(1024);
        transformHeader.setFlags(0x0001);
        transformHeader.setSessionId(testSessionId);

        // When
        byte[] aad = transformHeader.getAssociatedData();

        // Then
        assertEquals(52, aad.length); // AAD should be same size as transform header

        // Verify protocol ID (first 4 bytes) - 0xFD534D42 in little-endian