Using U2F keys in Debian
U2F is an open standard for two-factor authentication that can provided by cheap USB dongles.
WARNING: you might lock yourself out of your system while changing PAM configurations
Client side setup
Check for the USB dongle:
lsusb | grep U2F
Install the required libraries:
sudo apt-get install pamu2fcfg libpam-u2f
WARNING: Xscreensaver will require both your password and your U2F key
Create the key:
mkdir -p ~/.config/Yubico pamu2fcfg >> ~/.config/Yubico/u2f_keys
Add the following line at the end of /etc/pam.d/xscreensaver
auth required pam_u2f.so
Not supported yet.