How to set up a password less ssh login

sudo -s
ssh-keygen
cat /var/root/.ssh/id_rsa.pub | ssh <admin>@<remote server> 'cat >> ~/.ssh/authorized_keys'
exit

Then try it, should be able to login under sudo -s.

Great resource: http://osxdaily.com/2012/05/25/how-to-set-up-a-password-less-ssh-login/