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?

Thanks!

Some more info:

/etc/ssh/sshd_config

PermitEmptyPasswords yes

PubkeyAuthentication yes

ChallengeResponseAuthentication no

UsePAM yes

# passwd --delete root

# service ssh restart

sh@sh-desktop:~$ su - root

Password: 

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.