kazulog@sv1:~$ sudo sshd -T | grep -i permitrootlogin
permitrootlogin prohibit-password
kazulog@sv1:~$ ssh root@localhost whoami
root
kazulog@sv1:~$ printf 'PasswordAuthentication no\nPermitRootLogin no\n' | sudo tee /etc/ssh/sshd_config.d/10-hardening.conf
PasswordAuthentication no
PermitRootLogin no
kazulog@sv1:~$ sudo sshd -t && sudo systemctl reload ssh
kazulog@sv1:~$ sudo sshd -T | grep -i permitrootlogin
permitrootlogin no
kazulog@sv1:~$ ssh root@localhost whoami
root@localhost: Permission denied (publickey).
kazulog@sv1:~$ sudo journalctl -u ssh --no-pager --since '1 min ago' | grep -i root | tail -2
Sep 10 14:53:01 sv1 sshd-session[6335]: ROOT LOGIN REFUSED FROM ::1 port 36434 [preauth]
Sep 10 14:53:01 sv1 sshd-session[6335]: Connection closed by authenticating user root ::1 port 36434 [preauth]