}
                    }
                    else {
                        log.debug("Initialize signing");
                        byte[] signingKey = npa.getSigningKey(getContext(), negoResp.getServerData().encryptionKey);
                        if ( signingKey == null ) {
                            throw new SmbException("Need a signature key but the server did not provide one");
                        }

                        request = new SmbComTreeConnectAndX(
                            sess.getContext(),
                            ( (SmbComNegotiateResponse) nego ).getServerData(),
                            unc,
                            svc,
                            (ServerMessageBlock) andx);
                    }

                    response = sess.send(request, response);

        if ( this.negotiated == null ) {
            return null;
        }

        if ( this.negotiated instanceof SmbComNegotiateResponse ) {
            return ( (SmbComNegotiateResponse) this.negotiated ).getServerData().encryptionKey;
        }
        return null;
    }


    @Override
    public boolean isSigningOptional () throws SmbException {
        if ( this.signingEnforced ) {
            return false;