xfce4.12 not working with xdm

env info

FreeBSD: 10.2 xfce: 4.12 xdm: 1.1.11

issue

cant log into xfce via xdm

solution

vim /usr/local/lib/X11/xdm/xdm-config add the following content to end;

DisplayManager*authName: MIT-MAGIC-COOKIE-1

Caution:system update may rewrite this config.

LINKS

xfce fails to start from xdm Re: ports/154502: x11/xdm authorization failure when used with E17 window manager

In FreeBSD PR 154502, you wrote: > Xdm authorization fails after user login. > The user is unable to start an E17 window manager session, and is > returned to the xdm login screen.

> Fix: Need to add the missing option: > DisplayManager*authName: MIT-MAGIC-COOKIE-1

I take it that the error message XDM authorization key matches an existing client! appears in .xsession-errors.

I recently encountered this issue when trying to log in using xdm and xfce4-session. Adding the quoted line to xdm-config fixed the problem for me.

The cause is that the implementation of XDM-AUTHORIZATION-1 is broken if applications execve or unload/reload libX11/libxcb between connections to the X server. More information can be found in http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=486606

Since it is unclear whether XDM-AUTHORIZATION-1 will be fixed and if so, where, I think it is best to disable it in xdm. It looks like adding –disable-xdm-auth to xdm’s configure flags will do this but I have not tested it. I think the security impact is minimal; gdm does not use XDM-AUTHORIZATION-1 either.

Okay, good luck.