bug#23317: openssh: ssh client: xauth path is invalid - "/usr/X11R6/bin/xauth"

[ludo@gnu.org (Ludovic Courtès)]

Hi!

Danny Milosavljevic <dannym@scratchpost.org> skribis:

> But
>
>   $ ssh -Y -o XAuthLocation=$(which xauth) daya20
>
> works without the patch.
>
> And
>
>   $ ssh -Y daya20
>
> works with the patch.

I pushed the patch as commit 683a4a34cd4a565cbdb0b46a326e30795657814c.
This increases the closure size of OpenSSH from 89 to 118 MiB (+33%),
but I think it’s a useful addition.

> But
>
>   $ ssh -X daya20
>
> never works, with or without the patch. Huh.

I’ve straced “ssh -X”, and it shows that xauth fails like this:

--8<---------------cut here---------------start------------->8---
4742  write(2, "/gnu/store/86f0c3h99sl9z4x4w30hfy33i7nv2ik9-xauth-1.0.9/bin/xauth: (argv):1:  ", 78) = 78
4742  write(2, "couldn't query Security extension on display \":0.0\"\n", 52) = 52
4742  unlink("/tmp/ssh-FDByknME3mmd/xauthfile-c") = 0
4742  unlink("/tmp/ssh-FDByknME3mmd/xauthfile-l") = 0
4742  umask(022)                        = 077
4742  exit_group(1)                     = ?
--8<---------------cut here---------------end--------------->8---

This is because the SECURITY extension are disabled in our xorg-server
package.  We could configure it with --enable-xcsecurity, but upstream
disables it by default and it seems to be deprecated:

  https://www.x.org/wiki/Development/Documentation/Security/

Thoughts?

Ludo’.