(c) 2019 Jürgen Schmidt aka ju
All the details are in "Entspannt entsperrt, Linux-Authentifizierung mit mehr Komfort", c't 10/2019 Seite 132ff
This are PAM configuration files for demonstration purposes. They always allow authentication with your Linux system password as a last resort.
Attention: For Authentication with face recognition, U2F token and PIN you have to install and configure the respective PAM libraries first. The details are explained in the articles.
inc-pin+howdy-pw PIN+Face / Password
inc-pin+u2f-pw PIN+U2F-Token / Password
inc-u2f+howdy-pw U2F+Face / Password
inc-u2f-pw U2F-Token / Passwort
For installation copy the files to /etc/pam.d:
cd pam-demos/
sudo cp inc-* /etc/pam.d/
and replace for example in /etc/pam.d/sudo the line with "common-auth":
-@include common-auth
+@include inc-u2f-pw
+# @include common-auth