return null;
            this.sbuf[ 35 ] = (byte) b;
        }

        /*
         * Unless key returned is null or invalid Transport.loop() always
         * calls doRecv() after and no one else but the transport thread
         * should call doRecv(). Therefore it is ok to expect that the data
         * in sbuf will be preserved for copying into BUF in doRecv().
         */

                // It is more critical than other attributes because append mode depends on it.
                // We do only really care if we open for writing and not shared for writing
                // otherwise there are no guarantees anyway, but this stuff is legacy anyways.
                SmbComSeek seekReq = new SmbComSeek(config, 0);
                seekReq.setMode(0x2); // from EOF

                    else if ( trans.getContext().getConfig().isSigningEnabled() ) {
                        throw new SmbException("Signing enabled but no session key available");
                    }
                }
                else if ( log.isDebugEnabled() ) {
                    log.debug("No digest setup " + anonymous + " B " + isSignatureSetupRequired());
                }
                setSessionSetup(response);