From: JF Mezei

> I was just curious if it was normal for an X-server to give a different
> list of extensions depending on who was asking.
>
> Does the X server really know or care that a connection is via SSH ?


From time to time (for some of us, anyway), it can actually help to
read the documentation:

Apple3:~ sms$ man ssh

[...]
-X Enables X11 forwarding. This can also be specified on a per-host
basis in a configuration file.

X11 forwarding should be enabled with caution. Users with the
ability to bypass file permissions on the remote host (for the
user's X authorization database) can access the local X11 display
through the forwarded connection. An attacker may then be able
to perform activities such as keystroke monitoring.

For this reason, X11 forwarding is subjected to X11 SECURITY
extension restrictions by default. Please refer to the ssh -Y
option and the ForwardX11Trusted directive in ssh_config(5) for
more information.

-x Disables X11 forwarding.

-Y Enables trusted X11 forwarding. Trusted X11 forwardings are not
subjected to the X11 SECURITY extension controls.
[...]

------------------------------------------------------------------------

Steven M. Schweda sms@antinode-org
382 South Warwick Street (+1) 651-699-9818
Saint Paul MN 55105-2547