Some Context…
Github has deprecated using account passwords for authenticating Git operations on Github.com as written in this article. Now, if you’re like me and use the CLI often, you’d realise that using a PAT (personal access token) gets cumbersome real quick. So here’s a guide on how to use SSH keys for authenticating your Git operations to Github on the CLI.
This guide only covers the basic syntaxes and steps you need to do. Assuming that you could setup Git on your machine on your own or that you already have Git installed.
Configuring .gitconfig
If you don’t already have your .gitconfig file configured, here are a few things that is marginal to be inside your .gitconfig and some other nice-to-haves.
user.name and user.email
Your username and email should be inside your .gitconfig file. For context, the username can be different from your Github username, but the email should be the same. Since the email is going to be used to create the ssh-key later on.
$ git config --global user.name "your username"
$ git config --global user.email "your.mail@mail.com"
init.defaultBranch
After that, since Github changed the default branch name from master to main, you could also do that on your local machine with this command
$ git config --global init.defaultBranch main
Other Configurations
The rest of the configuration you can look at the man page for git-config or check the online version here. Here’s the rest of my config in my machine
$ git config --global core.editor nvim # main text editor
$ git config --global color.ui auto # colorful git
Configuring Local SSH Key
After setting up the .gitconfig now We can continue to creating a local SSH-Key. Github uses the SSH key to authenticate any Git operations to your repository.
Before anything, start by checking your local machine for an existing Ed25519 algorithm SSH key. Type this command to the terminal and check the output
$ cat ~/.ssh/id_ed25519.pub
If an error message saying “No such file or directory”, that means there’s no existing Ed25519 SSH key on your machine. If no such message appears, then you can continue to the next step.
Creating SSH Key
To create an SSH key with the Ed25519 algorithm, run the following command
$ ssh-keygen -t ed25519 -C "your.mail@mail.com"
💡 The
-Cflag is to write a comment, otherwise the key will be generated with your computer’s username. The convention is to use your email as a comment to indicate who generated the public key.
When a prompt appears asking you where to save the generated key, just press Enter.
Next, it will ask you for a password; enter one if you wish, if not just press Enter
Linking Local SSH Key with Github
Now, We need to register our new SSH key with Github to enable passwordless authentication when accessing from the CLI.
First, sign in into Github, and then click on your profile picture on the top right corner. Navigate to the Settings in the drop down menu.
Next, on the left hand side, click SSH and GPG Keys. Then, click the green button on the top right corner that says New SSH Key. Give a distinct name to your key so that it is easy to remember. Leave this window open as you proceed to the next steps.
Now, copy the existing SSH key on your local machine by running the following command
$ cat ~/.ssh/id_ed25519.pub
Highlight the output–which starts with ssh-ed25519 and ends with your email–and copy it to your clipboard.
Now, go back to GitHub in your browser window and paste the key you copied into the key field. Keep the key type as Authentication Key and then, click Add SSH key. You’re done! You’ve successfully added your SSH key!
Testing Your Key
To verify your SSH connection, you can follow this article from Github