SSH by Example

Mort Yao

1 Setting up an SSH server (the right way)

In /etc/ssh/sshd_config, enable public key authentication and disable password authentication: (perhaps change the default port also)

RSAAuthentication yes
PubkeyAuthentication yes

PasswordAuthentication no

Copy the client’s public key (e.g., id_rsa.pub) to the server’s authorized_keys:

$ ssh-copy-id [email protected]_host

Or:

$ cat ~/.ssh/id_rsa.pub |\
  ssh [email protected]_host "mkdir -p ~/.ssh && cat >> ~/.ssh/authorized_keys"

Make sure about permissions:

$ chmod 700 ~/.ssh
$ chmod 600 ~/.ssh/*
$ chown -R $USER ~/.ssh

Start (or restart) the SSH daemon: (using systemd)

# systemctl start sshd