SSH Setup for GitHub

Prerequisites

• Git installed
• GitHub account
• Email: testuser@gmail.com
• Username: testuser

Step 1: Check for Existing SSH Keys

ls -la ~/.ssh

Look for files like id_rsa.pub, id_ed25519.pub, or id_ecdsa.pub. If you have one, you can skip to Step 4.

Step 2: Generate a New SSH Key

Generate an SSH key using Ed25519 algorithm:

ssh-keygen -t ed25519 -C "testuser@gmail.com"

Options:

• Press Enter to accept the default file location (~/.ssh/id_ed25519)
• Enter a passphrase (optional but recommended for extra security)
• Or use -N "" flag to skip passphrase

Alternative for older systems: If your system doesn't support Ed25519, use RSA:

ssh-keygen -t rsa -b 4096 -C "testuser@gmail.com" 

Step 3: Start SSH Agent and Add Your Key

Start the ssh-agent in the background:

eval "$(ssh-agent -s)"

Step 4: Display Your Public Key

View your public SSH key:

cat ~/.ssh/id_ed25519.pub

Copy the entire output (starts with ssh-ed25519 and ends with your email).

Step 5: Add SSH Key to GitHub

• Go to GitHub SSH settings: https://github.com/settings/keys
• Click "New SSH key" or "Add SSH key"
• In the "Title" field, add a descriptive label (e.g., "Austin-Lenovo", "Work Laptop")
• Paste your public key into the "Key" field
• Click "Add SSH key"
• Confirm with your GitHub password if prompted

Step 6: Add GitHub to Known Hosts

Add GitHub's host key to avoid verification prompts:

ssh-keyscan -t ed25519 github.com >> ~/.ssh/known_hosts

Step 7: Test the SSH Connection

Test your SSH connection to GitHub:

ssh -T git@github.com

You should see a message like:

Hi testuser! You've successfully authenticated, but GitHub does not provide shell access.