I'd like to configure sshd_config to allow remote root logins without prompting for a password, but I do not want to configure passwordless ssh by copying the remote public key. In other words, I'd like to allow ssh root@host from anywhere without a password prompt. Is this possible to accomplish?
Some more info:
# passwd --delete root
# service ssh restart
sh@sh-desktop:~$ su - root
su: Authentication failure
sh@sh-desktop:~$ ssh -vvv root@localhost
OpenSSH_6.6.1, OpenSSL 1.0.1f 6 Jan 2014
debug1: Authentications that can continue: publickey,password
Permission denied, please try again.
I also tried to set UsePAM no, but than I cannot login at all. Perhaps something needs to be done in PAM config.