YubiKey

Chekc YubiKey by Yubico on online website.

Login with GDM

• EditInstall filelibraries

  apt install libpam-u2f
  

Create a global directory to save registered keys

mkdir /etc/Yubico

Register username's YubiKey in /etc/Yubico/u2f_keys_username

# On your YubiKey, touch the key when the light is flashing to verify the user presence.
pamu2fcfg -u "$SUDO_USER" > /etc/Yubico/u2f_keys_username

# For multiple YubiKey for same user.
pamu2fcfg -u "$SUDO_USER" -n >> /etc/Yubico/u2f_keys_username

# Content of /etc/Yubico/u2f_keys_username
username:BASE64CODE:BASE64CODE,es256,+presence

Edit file /etc/pam.d/gdm-password

@include common-auth
auth    [success=1 default=ignore]    pam_u2f.so    authfile=/etc/Yubico/u2f_keys_username    cue
auth    optional        pam_gnome_keyring.so
@include common-account

Test and Verify (Optional)

sudo apt install pamtester

pamtester gdm-password $USER authenticate