How to setup SSH?

If you want to setup SSH to remotely connect to machines then this guide is for you:

Execute the below command to generate the SSH key pair:

ssh-keygen -t rsa -f <path_to_your_key>/<name_of_your_SSH_key> -C <your_username>

You can add a passphrase for an added layer of security but this is optional.

You need two keys to establish the SSH connection:

Private Key: Used by the user to securely authenticate to the remote server

Public Key: Placed in the remote server

Copy the contents of the public key (public key is the key file with the .pub extension).

Execute the below commands in order to create the necessary directories and assign the permissions.

mkdir -p ~/.ssh
echo "PASTE_YOUR_PUBLIC_KEY_HERE" >> ~/.ssh/authorized_keys
chmod 700 ~/.ssh
chmod 600 ~/.ssh/authorized_keys

Now you can SSH to the remote server and verify using the below command:

ssh username@remote_host_ip

For added security you can

Disable password based login

Disable root login

If you wanna go ahead, then edit the sshd_config file:

sudo vim /etc/ssh/sshd_config

Make sure that these three lines are present

PasswordAuthentication no

PubkeyAuthentication yes

PermitRootLogin no

Restart the service

sudo systemctl restart ssh

Now you can securely connect to your system!