On Fri, Oct/23/2009 08:58:19AM, Alan Coopersmith wrote: > Ethan Mallove wrote: > > Hello, > > > > It seems I suddenly can not access my own DISPLAY. All X applications > > now error out with the following, e.g., > > > > $ xterm > > Xlib: connection to "sr1-ubur-20:34.0" refused by server > > Xlib: No protocol specified > > xterm Xt error: Can't open display: sr1-ubur-20:34.0 > > > > Is there an xauth command that can get X working for me again? > > Check your $XAUTHORITY & $HOME environment variables - those control > where libX11 looks for the cookies for authentication. > ($HOME/.xauthority is the default if $XAUTHORITY is not set) > > If those are set correctly and the cookie for your display is gone, > you would have to know the original magic cookie for the display in > order to re-add it with xauth, there is no "crack the display > security and recover my cookie" option. > > There's two copies made at session startup - one in your $XAUTHORITY > and one in a system directory that differs by display manager (gdm, > xdm, kdm, dtlogin, startx, etc.) that's passed to the X server started > (the -auth /path/to/file you can see in the arguments when running ps) > and is usually only readable by root. Authentication works by comparing > the one your client reads from the authority file and sends to the server > with the one the server read from it's copy of the file at startup. > > I suppose it might be possible to dig through the memory of currently > connected clients with a debugger to find the cookie they used, but > I've never tried that and don't know how easy it would be. > > If this is a recurring problem, things you could do when starting a > new session to protect against it in the future: > - keep a backup of your .xauthority so you can recover the cookie > if it gets overwritten > - run 'xhost +si:localuser:ethan' (or whatever username you use) > so that local connections from that uid are always accepted, > without needing a cookie.
The issue has been happening about once or twice a month, so I anticipate it will happen again. I have backed up my ~/.Xauthority file. When the problem reoccurs, I will do the following: $ cp ~/.Xauthority.backup ~/.Xauthority Many thanks! -Ethan > > -- > -Alan Coopersmith- [email protected] > Sun Microsystems, Inc. - X Window System Engineering > > _______________________________________________ > xorg mailing list > [email protected] > http://lists.freedesktop.org/mailman/listinfo/xorg _______________________________________________ xorg mailing list [email protected] http://lists.freedesktop.org/mailman/listinfo/xorg
