Finding out how gnome-keyring gets started on Lubuntu 15.04

Tags: Linux, Ubuntu

This week I’ve updated my Lubuntu 13.10 to 14.04 to 14.10 and finally to 15.04.

Then I noticed something strange, that I had never seen before: a gnome-keyring dialog showing up whenever I was asked to provide the passphrase for my ssh key. I don’t really understand why I need gnome-keyring dialog in my face when previously I could just type the passphrase at the terminal. (Feel free to enlighten me, explaining why this is better.)

Then I spent the next couple of hours trying to disable it, and trying to track down how it gets run, so I can have a better understanding of how my system works.

Easiest solution: just remove it!

What if I just remove the gnome-keyring package?

# apt-get remove gnome-keyring
Reading package lists... Done
Building dependency tree
Reading state information... Done
The following packages will be REMOVED:
  gnome-keyring lubuntu-desktop
0 upgraded, 0 newly installed, 2 to remove and 0 not upgraded.
After this operation, 3,730 kB disk space will be freed.
Do you want to continue? [Y/n]

It will also remove the lubuntu-desktop metapackage. While at first it might seem harmless, it may cause me trouble in the future. Packages that were previously installed because were dependencies of lubuntu-desktop will get autoremoved. New packages that may be introduced as dependencies of that metapackage won’t be installed. This can become specially troublesome during a dist-upgrade.

I want to find a way to disable it without uninstalling the package.

Finding all the places where LXDE starts applications

Lubuntu uses LXDE as the desktop environment, so it makes sense to check all the places where it runs applications.

First location is at Start menu → Preferences → Default applications for LXSession, or by simply running lxsession-default-apps. At the Core applications tab, there is an item called Security (keyring), which can have either ssh-agent or gnome as value. It was ssh-agent for me, and clearing that value to blank did not prevent gnome-keyring.

Then, at the same configuration tool, at Autostart tab, I looked for anything suspicious. Nothing relevant in there.

A blog post from 2012 (Wayback Machine) mentions that there are several *.desktop files that get autostarted, but are hidden from the Unity Startup Applications manager. So I tried un-hiding them:

sudo sed -i 's/NoDisplay=true/NoDisplay=false/' /etc/xdg/autostart/gnome*.desktop

No luck, still nothing exceptional was shown in the configuration tool.

As a last resort, I configured LXDE to completely disable autostart. I did it by changing Disable autostarted applications? (also found at the Autostart tab) from config-only to all. This option gets saved to ~/.config/lxsession/Lubuntu/desktop.conf as disable_autostart=all. After logging out and logging back in, I have an empty desktop with the window manager (Openbox) and nothing more. I open a terminal window and try using ssh… Damn, gnome-keyring is still running.

Testing other sessions and window managers

So, why exacly does gnome-keyring show up when running ssh? A quick check at the environment variables shows the reason:

$ env | sort | fgrep -i $'gnome\nssh'
GNOME_KEYRING_CONTROL=
GNOME_KEYRING_PID=
SSH_AUTH_SOCK=/run/user/1000/keyring/ssh

Interesting… If I log out and log in using a different session (such as TWM, Fluxbox or Openbox), those vars are not set. So, I’m actually seeking whatever script or binary that sets those vars. Unfortunately, it wasn’t that easy, because searching for those names (using grep or ack) in /etc/ yielded no results that could help me.

Searching elsewhere

Someone must have gone through this trouble and documented the solution somewhere, right?

I searched through the lubuntu-users mailing list, nothing relevant there.

I found GNOME Keyring page at ArchWiki (Wayback Machine), and it suggests removing the gnome-keyring-ssh.desktop file from /etc/xdg/autostart/ (actually, it suggests symlinking it to /dev/null).

I searched Ubuntu Forums, and found an interesting post by gmoore777 (Wayback Machine), dated from 2010. Certainly outdated, but contained the most detailed info so far. The post suggested removing the +x permission from gnome-keyring binary. Yes, it works, but that’s not something I wanted to do. Then it had several other suggestions, which I also tried.

So, no one described how it works and how to disable it… yet! This is why I’m writing this post.

Investigating the installed files

I started investigating further. (Or maybe nearer, because now I’m looking at stuff in my local machine, instead of stuff over the web.) What are the files installed by gnome-keyring?

$ dpkg -L gnome-keyring
[… several non-relevant files omitted …]
/etc/xdg/autostart/gnome-keyring-ssh.desktop
/etc/xdg/autostart/gnome-keyring-secrets.desktop
/etc/xdg/autostart/gnome-keyring-gpg.desktop
/etc/xdg/autostart/gnome-keyring-pkcs11.desktop
/usr/share/dbus-1/services/org.freedesktop.secrets.service
/usr/share/dbus-1/services/org.gnome.keyring.service
/usr/share/upstart/sessions/gnome-keyring.conf
/usr/share/upstart/sessions/gnome-keyring-ssh.conf
/usr/share/upstart/sessions/gnome-keyring-gpg.conf

I’ve already checked /etc/xdg/autostart/gnome-*.desktop files, and they are not being used.

I’ve tried removing those files from /usr/share/dbus-1/services/, but still no luck. (And, of course, I moved them back into place.)

I’ve also checked /etc/pam.d/ and commented the following line on lightdm and lightdm-greeter:

session optional        pam_gnome_keyring.so auto_start

As all other tries, nothing happened.

Only one directory I have not checked yet: /usr/share/upstart/sessions/

Putting all the pieces together

What is the process that is listening to that socket?

$ env | fgrep SSH
SSH_AUTH_SOCK=/run/user/1000/keyring/ssh
$ lsof /run/user/1000/keyring/ssh
COMMAND     PID     USER   FD   TYPE             DEVICE SIZE/OFF   NODE NAME
menu-cach 16218 denilson    3u  unix 0x0000000000000000      0t0 243759 /tmp/.menu-cached-

Hmm… Whatever this process is, it is not relevant. Maybe I need to run lsof as root?

$ sudo  lsof /run/user/1000/keyring/ssh
lsof: WARNING: can't stat() fuse.gvfsd-fuse file system /run/user/1000/gvfs
      Output information may be incomplete.
COMMAND     PID     USER   FD   TYPE             DEVICE SIZE/OFF   NODE NAME
gnome-key 16050 denilson   13u  unix 0xffff8800bb6ae680      0t0 240512 /run/user/1000/keyring/ssh
menu-cach 16218 denilson    3u  unix 0xffff8800c1560a80      0t0 243759 /tmp/.menu-cached-

A-ha! There it is: gnome-keyring with PID 16050. Maybe I can find its parent process… Sure, I could spend a lot of time reading ps manpage to find what which parameters will give me the info I need; or I could just run htop, press T to enter the tree mode, find the gnome-keyring process there, then follow the line up to its parent. That’s what I did.

And I found that upstart --user is the parent of gnome-keyring. In fact, the tree looks like this:

├─ /usr/sbin/lightdm
│  ├─ lightdm --session-child 12 19
│  │  ├─ /sbin/upstart --user
│  │  │  ├─ …
│  │  │  ├─ /usr/bin/lxsession -s Lubuntu -e LXDE
│  │  │  │  └─ …
│  │  │  ├─ upstart-dbus-bridge --daemon --session --user --bus-name session
│  │  │  ├─ upstart-dbus-bridge --daemon --system --user --bus-name system
│  │  │  ├─ upstart-file-bridge --daemon --user
│  │  │  ├─ upstart-udev-bridge --daemon --user
│  │  │  ├─ gnome-keyring-daemon --start --components pkcs11,secrets
│  │  │  └─ dbus-daemon --fork --session --address=unix:abstract=/tmp/dbus-RaSShjXvPa

So the login UI lightdm calls upstart --user, which in turn runs both gnome-keyring and lxsession. But why it doesn’t run on TWM, Fluxbox and Openbox sessions? The answer lies in /etc/upstart-xsessions:

# xsessions listed below are run inside an Upstart user session.
gnome
gnome-classic
gnome-fallback
gnome-flashback-metacity
gnome-flashback-compiz
kde-plasma
Lubuntu
Lubuntu-Netbook
lubuntu-nexus7
lxgames
qlubuntu
ubuntu
ubuntustudio
xfce
xubuntu
unity8-x11
unity8-mir

Solutions

The first real solution to prevent gnome-keyring from starting is to use another X session. I could select LXDE instead of Lubuntu, and since that one is not listed in /etc/upstart-xsessions, it won’t run upstart --user.

The second solution is to override the job properties. Session jobs (Wayback Machine) are started by upstart --user, and the configuration is read from:

  • $XDG_CONFIG_HOME/upstart/ (or $HOME/.config/upstart/ if $XDG_CONFIG_HOME not set)
  • $HOME/.init/ (deprecated - supported for legacy User Jobs)
  • $XDG_CONFIG_DIRS
  • /usr/share/upstart/sessions/

So I can create some *.override files with the manual directive (Wayback Machine).

This stanza will tell Upstart to ignore the start on / stop on stanzas.

And that’s what I did:

$ mkdir -p ~/.config/upstart
$ echo manual > ~/.config/upstart/gnome-keyring.override  # See note below.
$ echo manual > ~/.config/upstart/gnome-keyring-ssh.override
$ echo manual > ~/.config/upstart/gnome-keyring-gpg.override

After logging out and logging back in… Success! Woohoo! No more gnome-keyring and no root access was required! And also now I have a better understanding of my system and of upstart!

However, it was not without side-effects. Completely disabling gnome-keyring breaks nm-applet from Network Manager. The solution is to disable both ssh and gpg components of gnome-keyring, but leave the main deamon enabled and running.

Here is the final solution:

$ mkdir -p ~/.config/upstart
$ rm ~/.config/upstart/gnome-keyring.override
$ echo manual > ~/.config/upstart/gnome-keyring-ssh.override
$ echo manual > ~/.config/upstart/gnome-keyring-gpg.override
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