How to Setup SSH key for Git Operations in GitHub

Table of Contents

• Introduction
• Summary of Steps
• Create SSH Keys
• Copy Public key to GitHub Settings
• Clone Repo using SSH URL
• Issue and Resolution
• Bibliography and Reference

Introduction

• In this blog, we will see how to setup password-less Git operation for our GitHub repos
• Starting from Aug-13-2021 GitHub stopped supporting password authentication for repository related Git Operations.
• Instead, token-based authentication methods like personal access, OAuth, SSH Key, or GitHub App installation token will be required for all authenticated Git operations.
• In this blog, we will see how to setup SSH key based authentication in GitHub for doing Git operations

Summary of Steps

• Step 1: Create SSH keys for your workstation using ssh-keygen command
• Step 2: Copy the SSH Public Key into GitHub Settings
• Step 3: Use SSH URL for the repository to clone

Create SSH Keys

I'm using Ubuntu OS workstation and performed the steps in it.

• Open terminal and Run ssh-keygen command The command creates following two files in $USER_HOME/.ssh directory,
• id_rsa private key file, and
• id_rsa.pub public key file

$ ssh-keygen
Generating public/private rsa key pair.
Enter file in which to save the key ($USER_HOME/.ssh/id_rsa):

Then press enter, to move further,

• It is important to Enter passphrase for your SSH key, to use the key for cloning private repo from GitHub

Enter passphrase (empty for no passphrase): 
Enter same passphrase again: 

Finally, we can see the below output, which shows the path where the public and private key files are stored

Your identification has been saved in $USER_HOME/.ssh/id_rsa.
Your public key has been saved in $USER_HOME/.ssh/id_rsa.pub.
The key fingerprint is:
SHA256:VRqScsqwertyuioXGpazvfrw username@workstation_name
The key's randomart image is:
+---[RSA 2048]--+
| .+. o=o .     |
|.. o.oo.+      |
|o .   oo+ o    |
|.+   o -= +    |
|o   . o S      |
| .o+   o .     |
|.o..+ o O.     |
|o.o .-- =O.*.  |
|.+..E ooO.     |
+----[SHA256]---+

Copy Public key to GitHub Settings

• Goto GitHub Settings

• Select SSH and GPG key from left pane

• Select New SSH key

• Copy your workstation's (id_rsa.pub) public key content here

• Save and the key will be listed in the SSH key section

Clone Repo using SSH URL

• Now you can use the SSH URL to clone the repository

• While cloning, you would be prompted to enter the SSH key password

$ git clone git@github.com:github_userid/repo_name.git
Cloning into 'repo_name'...
Enter passphrase for key '$USER_HOME/.ssh/id_rsa': 
Checking connectivity... done.

• Once you enter your SSH key password, the repo will be cloned in your workstation

Issue and Resolution

• Sometime we will get below error while updating the old repo, which was previously cloned using http and username/password,

`fatal: could not read Username for 'https://github.com': terminal prompts disabled`

• Use the command to get rid of the issue.

# To avoid the error 
# we need to change gt config to use ssh/git method
git config --global --add url."git@github.com:".insteadOf "https://github.com/"

• Windows WSL and Ubuntu Permission denied (publickey) error.
• When you setup Github login in windows using WSL and Ubuntu make sure to create the SSH key file using the name id_rsa only. If we try to use other names as key file name, then we will get Error: Permission denied (publickey) error.
• Refer the docs here

Bibliography and Reference

GitHub Docs for Working with SSH key

GitHub Docs for cloning repo using SSH URL

Creating SSH key for Windows 10