Getting the fingerprint reader of a Thinkpad x240 to work under Ubuntu 14.04

README.md

lsusb lists the fingerprint reader in the x240 as follows:

Bus 002 Device 003: ID 138a:0017 Validity Sensors, Inc.

There exists experimental driver support for this in a fork of libfprint for vfs5011 sensors, however you'll need to compile the driver yourself. To get the fingerprint sensor to work for lightdm login, su etc, follow these steps.

1. Install fingerprint-gui:

   sudo add-apt-repository ppa:fingerprint/fingerprint-gui
   sudo apt-get update
   sudo apt-get install libbsapi policykit-1-fingerprint-gui fingerprint-gui
   

2. Get your compilation tools and library dependencies:

   sudo apt-get install build-essential automake checkinstall shtool libtool libxv-dev libmagick++-dev
   

3. Get the sources, compile and install them:

   git clone https://github.com/abbradar/fprint_vfs5011
   cd fprint_vfs5011
   ./autogen.sh
   make
   sudo make install
   

4. Make sure your user has permissions for accessing the fingerprint sensor device. Create a file /lib/udev/rules.d/40-libfprint0-custom.rules with the following contents:

   # Device Validity VFS5011
   ATTRS{idVendor}=="138a", ATTRS{idProduct}=="0017", MODE="0664", GROUP="plugdev"
   

5. Add your user to the plugdev group:

   sudo usermod -a -G plugdev <username>
   

6. Restart udev:

   sudo service udev restart
   

7. Log out of your session and log back in.

8. Enroll your fingerprints with fingerprint-gui, verify them, then see if a sudo -s now suddenly asks you for your fingerprint.

@ccoenen

I am using a ThinkPad X240 with Debian 8 (Jessie). I only have the main repository enabled, so no non-free repositories enabled.

Since Ubuntu 14.04 (Trusty Tahr) is the newest LTS available (next one will come 2016 – 16.04), which may (but mustn't necessarily) mean that the packages are slightly more stable, I think it's smart to set the Ubuntu version to trusty instead of utopic (14.10, not an LTS), like you did:

deb http://ppa.launchpad.net/fingerprint/fingerprint-gui/ubuntu trusty main
deb-src http://ppa.launchpad.net/fingerprint/fingerprint-gui/ubuntu trusty main

On another note: I prefer to store individual third-party repositories in individual files. To do this, simply
# touch /etc/apt/sources.list.d/fingerprint-gui.list
(or whatever name you'd like), then put the content above in it.

I can confirm that after this the fingerprint scanner works. In fingerprint-gui your finger will look weirdly squished and pinched, and at first I thought the driver was not working correctly. I tried "verifying" my finger, and it always failed. Turns out that you have to be careful to precisely repeat the motion you did when registering the finger. I remember the fingerprint scanner in my old HP notebook, it didn't seem to be as picky as the X240's one. I had to try again and again many times until I finally got it work, so if you're reading this and can't get yours to work, don't give up. :)

Just to add to the last part of @Lesik comment, make sure you swipe your finger fast so you get an actual fingerprint look in the capture, instead of just a stretched fingerprint.

i installed all packages and libraries, i didn't get the build to work after 'make' fprint, but i fingerprint-gui worked on ubuntu 17.10 and Thinkpad X240, i set up my fingerprint and now kdm login ask for fingerprint and it works!

I followed all the steps and when I do

sudo -s

I am asked for my fingerprint and if I swipe that, it authenticates. So that worked.

However, I cannot swipe my finger at login (Ubuntu 18.04.1). There is no option to enable fingerprint login in the 'Users' section of Ubuntu's preferences. Any idea how I can activate it? ^^