Yeah, it is 12. Here is a basic usage guide: # groupadd yubikey # usermod -G yubikey USERNAME # echo "yubikeyid" >> /home/USERNAME/.ssh/trusted_yubikeys

Yeah, it is 12. Here is a basic usage guide: # groupadd yubikey # usermod -G yubikey USERNAME # echo "yubikeyid" >> /home/USERNAME/.ssh/trusted_yubikeys # (yubikeyid is first 12 characters of the OTP) # chmod 755 /usr/local/bin/yubikey.sh # (this file is /usr/local/bin/yubikey.sh) # echo "Match group yubikey" >> /etc/ssh/sshd_config # echo " ForceCommand /usr/local/bin/yubikey.sh" >> /etc/ssh/sshd_config # (that's a tab before ForceCommand) # /etc/init.d/ssh restart