Linux Server Install: Part 4

If you done messed up and forgot to install SSH Server — I got you, bruh.

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Linux Server Install: Part 3

Install SSH

Now I know some distributions will ask you this during the installation but I’m going to cover it just in case you chose no.

To install and configure an SSH server on Ubuntu 20.04 and enable key-based authentication, follow these steps:

Install the OpenSSH server package:

sudo apt update && sudo apt install -y openssh-server

Now before we ssh in you have a couple of options:

1. You can use password-based authentication.
2. You can set up SSH keys and use key based authentication.

This is really going to be up to you, but I’ll show you how to set up key base authentication.

Generate an SSH Key Pair

Generate an SSH key pair on your client machine:

ssh-keygen

This will create a public and private key pair in the ~/.ssh directory on your client machine. The public key will be called id_rsa.pub and the private key will be called id_rsa.

Copy the public key to the server:

ssh-copy-id user@server

Replace user with your username on the server and server with the hostname or IP address of the server.

Note

Be sure to copy over the public key before making changes to the sshd_config file

Disable Password-Based Authentication

On the server, edit the /etc/ssh/sshd_config file to enable key-based authentication and disable password-based authentication:

sudo nano /etc/ssh/sshd_config

Find the line that says PasswordAuthentication yes and change it to PasswordAuthentication no. This will disable password-based authentication and allow only key-based authentication.

Another line that you should add is ChallengeResponseAuthentication no

Save and restart the SSH Server to apply the changes:

sudo systemctl restart ssh

Now, you should be able to log in to the server using your private key from your client machine:

ssh user@server

You will not be prompted for a password, and you will be logged in to the server using key-based authentication.

That’s it! You have successfully installed and configured an SSH server on an Ubuntu Server and enabled key-based authentication.

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Linux Server Install: Part 5