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1-3 Establishing an SSH Connection

In this tutorial, you will learn how to establish an SSH connection between your personal PC and a remote PC running Ubuntu.

Having a GitHub account created is optional to store your authentication keys.

System Requirements​

  • Local machine: A supported OpenSSH-compatible SSH client must be installed.
  • Remote host: OpenSSH server installed on Ubuntu 16.04 or later.

Step 1: Install OpenSSH​

On Your Client Machine:

Install a supported OpenSSH-compatible SSH client by entering the following command in your terminal:

sudo apt install openssh-client

Install Visual Studio Code and the Remote-SSH extension.

On the Server/Host:

Install the OpenSSH server by running the following command in the terminal:

sudo apt install openssh-server

Step 2: Generate SSH Keys​

To generate the SSH key, run the following command:

ssh-keygen -t rsa

This will generate keys using the RSA algorithm. To modify the number of bits, you can use the -b option. For example, to generate keys with 4096 bits, use:

ssh-keygen -t rsa -b 4096

During the process, you will be prompted for a password. Simply press Enter three times when prompted to create the key. By default, the public key is saved in the file ~/.ssh/id_rsa.pub, while the private key is stored in ~/.ssh/id_rsa.

Next, copy the id_rsa.pub file to the remote host and append it to ~/.ssh/authorized_keys by running:

ssh-copy-id username@remotehost_ip
  • username: The name of the user on the host machine.
  • remotehost_ip: The IP address of the host machine. You can find this in the Wi-Fi settings.

After this step, you will be able to establish an SSH connection to the host without being prompted for a password.

Step 3: Import Keys from GitHub (Optional)​

You may also register your SSH keys with services like GitHub. To export your keys, open the following file:

~/.ssh/id_rsa.pub

Using Notepad or any text editor, select all the contents and copy it.

Next, go to your GitHub settings, select "SSH and GPG keys", and click "New SSH key".

GitHub0

Paste your copied SSH key into the "Key" field and provide a title that is easily identifiable for you. Select "Authentication Key" as the key type.

GitHub1

On your host machine, enter the following command in your terminal:

ssh-import-id-gh username-on-github

The -gh flag tells the tool to fetch the key from GitHub.

References​