pyxtrlock

pyxtrlock is a rewrite of Ian Jackson's great xtrlock program using modern libraries, most importantly the obsolete direct passwd/shadow authentication has been replaced by today's PAM authentication mechanism, hence it also works on Fedora. Also, it's mostly written using XCB instead of Xlib, although some Xlib/XCB interaction is still necessary. As soon as XCB can provide the required services of Xlib, the remaining code will be ported to XCB.

Since pyxtrlock uses PAM authentication, it can be run as the normal user and doesn't need special privileges.

Description

pyxtrlock, like its predecessor, is a very minimal X display lock program. While pyxtrlock is running, it doesn't obscure the screen, only the mouse and keyboard are grabbed and the mouse cursor becomes a padlock. Output displayed by X programs, and windows put up by new X clients, continue to be visible, and any new output is displayed normally.

In good Unix tradition, pyxtrlock provides no visual feedback during password entry. You simply type your password at it, followed by Enter or Newline. Pressing Backspace or Delete erases one character of a password partially typed; pressing Escape or Clear clears anything that has been entered.

Like xtrlock, pyxtrlock will ignore further keystrokes until a timeout has expired after too many attempts have been made in too short time.

Installation and Usage

Install python3-simplepam for dependencies:

$ git clone git://github.com/leonnnn/python3-simplepam.git
$ cd python3-simplepam
$ sudo python3 setup.py install

Clone and install pyxtrlock:

$ git clone git://github.com/leonnnn/pyxtrlock.git
$ cd pyxtrlock
$ sudo python3 setup.py install

Once this is done, you should be able to simply lock your display by running

$ pyxtrlock

If you would like to automatically lock your screen after some idle time, we recommend the xautolock tool. Just add something like

xautolock -locker pyxtrlock -time 5

to your X autostart file to lock the screen with pyxtrlock after 5 minutes idle time. xautolock has many other useful features, see its documentation. Most distributions provide an xautolock package with a man page.

Bugs

Additional input devices other than the keyboard and mouse are not disabled.

Although this is not a bug, please note that pyxtrlock does not prevent a user from switching to a virtual terminal, so be advised to always leave your terminals locked.

Please report any new bugs you may find to our Github issue tracker.

Configuration

The padlock icon can be changed. It is stored as a pickle of a dictionary, and the tools directory contains a tool for generating cursors from image files.

The default cursor file is placed at PREFIX/share/pyxtrlock/lock.pickle while the cursor file at ~/.config/pyxtrlock/lock.pickle takes precedence if present.

PLEASE NOTE: The pickle file format is not designed to be resistant against maliciously crafted files. Therfore do not open pickle files from untrusted sources as they may compromise your system. The default padlock file is created on install (by make_default_lock.py).

Requirements

python3-simplepam
Python ≥ 3.0
libxcb
libxcb-image
libX11 ≥ 1.4, or libX11 ≥ 1.2 compiled with XCB backend

These requirements are met at least on

Debian wheezy and sid, and probably on Debian squeeze (untested; please report your experience)
Ubuntu ≥ 11.10, and probably 10.04 (untested; please report your experience)
Fedora ≥ 16

Authors

Leon Weber leon@leonweber.de
Sebastian Riese s.riese@zombofant.net

pyxtrlock has been inspired by Ian Jacksons's brilliant xtrlock program and uses many ideas and techniques from the xtrlock source code. Also, the lock icon has been copied from xtrlock.

License

This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

zombofant / pyxtrlock