who cares about the 2nd factor? just the hardware key needed!
1pacman -S pam-u2f
replace ~/.config
with $XDG_CONFIG_HOME
origin and id is set to enforce a stable name
1# first key
2pamu2fcfg -i pam://hostname -o pam://hostname > ~/.config/Yubico/u2f_keys
3# other keys
4pamu2fcfg -n -i pam://hostname -o pam://hostname > ~/.config/Yubico/u2f_keys
~/.config/Yubico/u2f_keys
1username:xxxxxx..key1..xxxxxx:xxxxxx..key2..xxxxxx
/etc/pam.d/sudo
1auth sufficient pam_u2f.so cue origin=pam://hostname appid=pam://hostname
2...