--- description: meta description tags: ubuntu, ssh --- Allow root ssh login with public key authentication = 1. As root, edit the sshd daemon configuration file (/etc/ssh/sshd_config). 2. Modify the PermitRootLogin and the PubkeyAuthentication parameters to have the following values. ```bash= PermitRootLogin without-password PubkeyAuthentication yes ``` 3. gen host key ```bash= $ ssh-keygen -t dsa -f /etc/ssh/ssh_host_dsa_key $ ssh-keygen -t rsa -f /etc/ssh/ssh_host_rsa_key $ chmod 600 /etc/ssh/ssh_host_dsa_key $ chmod 600 /etc/ssh/ssh_host_rsa_key ``` 4. Restart the sshd daemon. ```bash= $ systemctl restart sshd.service ``` 5. Copy public key into target ```bash= mkdir -p ~/.ssh/ cat << EOF > ~/.ssh/authorized_keys ssh-rsa ... EOF ```