}
                    } 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");
                        }

        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;