class PreauthHashAndEncryption {
        @Test
        @DisplayName("calculatePreauthHash rejects non-SMB2 or missing negotiation")
        void preauthHash_rejectsWhenUnsupported() {
            // Not SMB2
            assertThrows(SmbUnsupportedOperationException.class, () -> transport.calculatePreauthHash(new byte[] { 1 }, 0, 1, null));

            // SMB2 flag set but no negotiation

        setPrivateField(transport, "smb2", true);
        setPrivateField(transport, "negotiated", negotiateResponse);

        // Calculate hash
        Method calcMethod = findMethod(transport.getClass(), "calculatePreauthHash", byte[].class, int.class, int.class, byte[].class);
        calcMethod.setAccessible(true);

        byte[] input = "test data".getBytes();
        byte[] oldHash = new byte[64];

                    this.preauthIntegrityHash = trans.calculatePreauthHash(reqBytes, 0, reqBytes.length, this.preauthIntegrityHash);

                    if (response.getStatus() == NtStatus.NT_STATUS_MORE_PROCESSING_REQUIRED) {
                        byte[] respBytes = response.getRawPayload();
                        this.preauthIntegrityHash = trans.calculatePreauthHash(respBytes, 0, respBytes.length, this.preauthIntegrityHash);

        }
    }

    private void updatePreauthHash(final byte[] input) throws CIFSException {
        synchronized (this.preauthHashLock) {
            try {
                this.preauthIntegrityHash = calculatePreauthHash(input, 0, input.length, this.preauthIntegrityHash);
            } catch (Exception e) {
                log.error("Failed to update pre-auth integrity hash", e);