Comment 1 for bug 1922212

This gets worse. Adding the following to the tail of /etc/ssh/sshd_config does not configure the service properly.

   PasswordAuthentication no
   ChallengeResponseAuthentication no
   UsePAM no
   PubkeyAuthentication yes
   PermitRootLogin no

The login attempts are still allowed:

Apr 01 09:31:10 localhost sshd[239597]: pam_unix(sshd:auth): authentication failure; logname= uid=0 euid=0 tty=ssh ruser= rhost=49.88.112.77 user=root
Apr 01 09:31:13 localhost sshd[239597]: Failed password for root from 49.88.112.77 port 50368 ssh2
Apr 01 09:31:16 localhost sshd[239597]: Failed password for root from 49.88.112.77 port 50368 ssh2
Apr 01 09:31:19 localhost sshd[239597]: Failed password for root from 49.88.112.77 port 50368 ssh2
Apr 01 09:31:20 localhost sshd[239597]: Received disconnect from 49.88.112.77 port 50368:11: [preauth]
Apr 01 09:31:20 localhost sshd[239597]: Disconnected from authenticating user root 49.88.112.77 port 50368 [preauth]
Apr 01 09:31:20 localhost sshd[239597]: PAM 2 more authentication failures; logname= uid=0 euid=0 tty=ssh ruser= rhost=49.88.112.77 user=root