Forward X11 over SSH after you su
February 3rd, 2010
Enabling SSH forwarding for X11 in general is easy: you simply put X11Forwarding yes in /etc/ssh/sshd_config, then SSH into the server with the -X or -Y (as appropriate for you).
However, if you want to be able to SSH in as a non-privileged user and su to become root, you’ll need to do a little more. Adding the following to the non-privileged user’s .bashrc works for me:
# Allows su to use X11
if [ ! -n "$XAUTHORITY" ]; then
export XAUTHORITY=~/.Xauthority
fi
su passes environment variables to the new shell, so this ensures that applications that use the X server know where to look for the SSH forwarding info.
This manual configuration isn’t an issue with all distributions, but was required for my Debian Lenny box.
