This post is a mini tutorial on how to enable the fingerprint reader of the Dell XPS 9500 laptop on Ubuntu 23.04.
Install fprintd:
sudo apt install fprintd libpam-fprintd
If you are another laptop and you are lucky your fingerprint reader might work out of the box. On Dell XPS 9500, you need to download the lastest driver from http://dell.archive.canonical.com/updates/pool/public/libf/libfprint-2-tod1-goodix/
wget http://dell.archive.canonical.com/updates/pool/public/libf/libfprint-2-tod1-goodix/libfprint-2-tod1-goodix_0.0.6-0ubuntu1~somerville1_amd64.deb
sudo dpkg -i libfprint-2-tod1-goodix_0.0.6-0ubuntu1~somerville1_amd64.deb
After this open the Users page in the System Settings. There should be a new button named “Configure Fingerprint Authentication…”. From here you should be able to enroll your fingerprint.
You can also use the fprintd tools to manage your fingerprint:
fprintd-listto list the registered fingerprintsfprintd-enrollto rengister new fingerprintsfprintd-verifyto check previously registered fingerprints
Finally, you must configure pam to use your fingerprint. You can select for which authentication process fingerprints will be used and if they are required, acting like a 2FA, or if they are sufficient, working in parallel of your password. I recommend to use them in sufficient mode, at least in a first time, so that you can still use your password if you encounter an issue.
As an example if you want to use fingerprints to sudo, you need to add auth sufficient pam_fprintd.so in /etc/pam.d/sudo, just before the line @include common-auth. Then the next time you use sudo, it will display Place your finger on the fingerprint reader instead of prompting for your password. If you want to use your password you can use Ctrl+C to cancel the fingerprint request.