I have a subsystem which is intended to be directly connected to the ssh server via pipes. Similar to stfp/scp However if the client side allocated a pty via "pty-req" just prior to invoking the subsystem this will cause the subsystem protocol to appear to be broken do to the allocated pseudo-terminal and resulting line discipline device. I did not find any evidence of the sftp service side code doing any validation of its stdin/stdout to confirm if they were connected to a tty device isatty(). Some of the options my subsystem could do: 1. exit the subsystem if a pty was allocated for its session. i.e SSH_TTY is set for example. 2. reconfigure the line discipline setting in order to still make the protocol still work. (ex: stty -opost). This would probably be unacceptable since the client is fully capable of doing this configuration and any re-configuration by the server may interfere which the clients configuration. 3. Are there any options in OpenSSH to "undo the pty" allocation and revert to a non-pty command ? I can use the PermitTTY=no setting, but this cannot be isolated to this subsystem. 4. do nothing and consider this a garbage in/garbage out use-case. Furthermore, in my use-case the same ssh listening port is used for both regular shell access as well as subsystem access. Therefore in the case of regular shell access a PTY is required. _______________________________________________ openssh-unix-dev mailing list openssh-unix-dev@xxxxxxxxxxx https://lists.mindrot.org/mailman/listinfo/openssh-unix-dev
