Linux – x11 forwarding not working

linuxmacx11forwarding

I'm having trouble getting x11 forwarding when I ssh into a linux machine from a MAC operating Mojave. When I do ssh -X username@serveraddress, I get the following error appearing after I successfully login:

/usr/bin/xauth: error in locking authority file /home/username/.Xauthority

I have tried to follow the fixes suggested to this problem on stackoverflow but they don't seem to work.

I have tried editing ~/.ssh/config so that it looks like this:

Host *
    XAuthLocation /opt/X11/bin/xauth

This does not fix the problem. Any ideas would be greatly appreciated.

Best Answer

Obviously you should remove the change you made to $HOME/.ssh/config. It doesn't work, and never will, because the path is wrong, and that takes place on the server side anyway.

After that, you should ssh to the server and delete the existing $HOME/.Xauthority file. Then log out, and ssh back in.

This error occurs because the file could not be locked, and that is usually also because it could not be written. So if the problem persists, check the permissions of your home directory on the server.

Try ssh -Y

Any reason you don't want to use the -Y flag instead of the -X flag?

Quite simply, the difference between -X and -Y is that -Y enables trusted X11 forwarding.

SSH X11 not working

The reason ssh X forwarding wasn't working was because I have a /etc/ssh/sshrc config file.

The end of the sshd(8) man page states:

If ~/.ssh/rc exists, runs it; else if /etc/ssh/sshrc exists, runs it; otherwise runs xauth

So I add the following commands to /etc/ssh/sshrc (also from the sshd man page) on the server side:

if read proto cookie && [ -n "$DISPLAY" ]; then
        if [ `echo $DISPLAY | cut -c1-10` = 'localhost:' ]; then
                # X11UseLocalhost=yes
                echo add unix:`echo $DISPLAY |
                    cut -c11-` $proto $cookie
        else
                # X11UseLocalhost=no
                echo add $DISPLAY $proto $cookie
        fi | xauth -q -
fi

And it works!

Best Answer

Related Solutions

SSH – Warning: Untrusted X11 Forwarding Setup Failed

Try ssh -Y

SSH X11 not working

Related Topic