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;