Setup on macOS based client

Copy your public key to the server

• [your_public_key] is usually named id_rsa.pub or id_ed25519.pub
• If password authentication is disabled, this must be done by someone who already has a public key on the server

ssh-copy-id -i ~/.ssh/[your_public_key] [user]@[host_name] -p [port]

Connect to the server

ssh [user]@[host_name] -p [port]

Create a new host to connect easily

• Add the server to your ~/.ssh/config in order to connect just by ssh [alias]:

Host [alias]
  User [user]
  HostName [host_name]
  Port [port]
  IdentityFile ~/.ssh/[your_private_key]

Setup on macOS based server

Start/stop SSH

sudo systemsetup -setremotelogin on
sudo systemsetup -setremotelogin off

Disable password authentication

• To prevent authentication without publickey, in the /etc/ssh/sshd_config file, set:

PasswordAuthentication no
KbdInteractiveAuthentication no
UsePAM no

Restart SSH daemon

• Required to register changes in the config file

sudo launchctl stop com.openssh.sshd
sudo launchctl start com.openssh.sshd