Using SSH and X: X11 connection rejected because of wrong authentication.

[joehill]

Hi,

I've been using ssh to log in from my laptop (running Ubuntu Breezy) to my server (running Kubuntu Breezy) and run various programs remotely in X-windows, but suddenly I'm getting error messages when I try to do that. If I run a GTK/gnome application it give me this error:

X11 connection rejected because of wrong authentication.
X connection to localhost:10.0 broken (explicit kill or server shutdown).

or this one:

X11 connection rejected because of wrong authentication.
The application 'gedit' lost its connection to the display localhost:10.0;
most likely the X server was shut down or you killed/destroyed
the application.

If I run KDE/Qt applications I get this error:

X11 connection rejected because of wrong authentication.
: Fatal IO error: client killed

A while back I tried rebooting the server and everything worked fine again for about a day, and then the problem came back. I at first thought it was a problem with my home directory but it's the same whether I'm running as root or any other user.

I'd appreciate any help I can get on this.

Thanks, Joe

[joehill]

Well, I ended up rebooting again and it fixed the problem again for now. After reading a post on another forum by someone who had the same problem because of low disk space, I checked my "/" partition, which was somewhat low on space (down to 330 MB--which I would think is plenty but these days things take a lot of space) and I moved some stuff to another partition and it's been working since then. I'm crossing my fingers that this was the problem, but we'll see.

Joe

[noob_Lance]

how did you get the C to display? i still cant figure that out for the life of me..

[joehill]

What do you mean by "C"?

[noob_Lance]

sorry.... i ment to hit X

[joehill]

Do you mean how did I get the server to forward X information to the client? If so, you do "ssh -X me@myhost.mydomain.net." That's the option that specifies to forward the X connection and not just the terminal text. If that doesn't work you can use -Y instead of -X, which is for forwarding over a trusted connection (apparently less secure than -X, I'm not sure exactly what the implications of this are). Does this answer your question?

[kiwigander]

As an alternative, you can edit the /etc/ssh/ssh_config file on the client so it contains the line

Forward X11 yes

(I believe the stock Ubuntu Breezy installation starts off with that line as

# Forward X11 no

so I assume that the default setting is "no".)

[joehill]

Ok, that's simpler. Thanks for the pointer.

[noob_Lance]

it is set to yes and even when i tried the -X or -Y it still did not work for me..

[MJN]

It also needs enabling in your server...

X11Forwarding YES

..?

[noob_Lance]

yes it is enabled on my server..

[hil]

I got exactly the same problem here. I can't ssh to the ubuntu 6.06 server

my command: ssh -l h -Y 192.168.12.5

X11 connection rejected because of wrong authentication.
The application 'gedit' lost its connection to the display localhost:10.0;
most likely the X server was shut down or you killed/destroyed
the application.

[hil]

I posted a solution to another page (http://ubuntuforums.org/showthread.php?p=1361790#post1361790)

Please take a look and see if that helps:confused:

[mirak63]

I needed to put x11forward yes in /etc/ssh/ssh_config
This allow connecting clients to do ssh forwarding.
I though it would be in sshd_config but it was already on yes.

[mohnkern]

I saw this same problem, and have a different issue. I thought I'd put it here for documentation.

Somehow my .Xauthority file on my computer on my home box got its ownership changed.

doing:

sudo rm $home/.Xauthority*

and then logging out and back in resolved the issue.

[gulincho]

For me, the problem was:

No space left on device (28)

I cleaned up /usr/cache/apt/archives.

[bankg3]

I had a similar problem but my .Xauthority file wasn't the issue. When I first would ssh into my box I would get this message

sh: /usr/bin/xauth: Permission denied

so I checked my xauth file and the permissions were wrong.
-rwxr--r-- 1 root root 28K 2006-01-04 22:43 xauth

I changed the permissions "sudo chmod 755 /usr/bin/xauth" so I could execute the file and then everything worked ok. The next time I logged in a new .Xauthority file was created and everything worked.

[dgavenda]

doing:

sudo rm $home/.Xauthority*

and then logging out and back in resolved the issue.


Worked for me too!!

[alonsorm77]

Hello Guys!

I experimented the same problem, then i realized that i was working with big files, i erased some of them and the problem was corrected.

Is the HD space!

Thanks

[jis]

Worked for me too!!

It worked for me, too. I had three files: .Xauthority, .Xauthority-c and .Xauthority-l. I moved them to a subdirectory in case I need them later. When I logged back, a new .Xauthority file was created with different ownership.

[MJN]

This can often happen (i.e. .XAuthority ownership changes to root) if you start X using sudo.

Mathew