}
                    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");
                        }

            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;
        }