Ubuntu – Login using fingerprint reader

I had the same issue and this worked for me:

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

This works for many fingerprint readers including 138a:0011 and 138a:0018 as well.

from “Fingerprint readers integration” team on launchpad

Ubuntu 18.04 minimum dist comes with gdm3 pre-configured when you perform a clean install. While the docs here FingerpringGui Docs Do say its 18.04 compatible i have been having issues trying to get it to login in using a fingerprint hiding the user login and using the finger to find user and password. (This is risky to do so don't do it unless you can be sure it works)

After trying many different options i finally came to the solution on just removing gdm3 and installing lightdm.

sudo apt install lightdm

when asked which should be the default display manager select lightdm

There is no need to reinstall fingerprint-gui just open click on the settings tab and verify that

a) lightdm, gnome-screensaver, sudo and su are not greyed out. b) Check all the tests pass.

You should now be able to use the fingerprint scanner for all of the above.
If you test lightdm or gnome-screensaver and you get ok, but the test button is grayed out. Don't panic hit enter.

Restart your computer and voila.

With 18.04 for now I would wait before removing the login inputs and using the fingerprint-gui, 1 to many function that helps to find a user and password.