GitHub SSH Setup Using OpenSSH (Linux / Raspberry Pi)

This walkthrough shows how to configure OpenSSH so you can access GitHub using SSH (git clone, git pull, git push) without passwords or tokens.

1. Install required packages

sudo apt update sudo apt install -y git openssh-client 

2. Create the SSH directory

mkdir -p ~/.ssh chmod 700 ~/.ssh 

3. Generate an SSH key for GitHub (ed25519)

ssh-keygen -t ed25519 -C "enkiel@rpi-github" -f ~/.ssh/id_ed25519 

• Press Enter to accept the default location
• Passphrase is optional but recommended

This creates:

• ~/.ssh/id_ed25519 (private key)
• ~/.ssh/id_ed25519.pub (public key)

4. Start ssh-agent and load the key

eval "$(ssh-agent -s)" ssh-add ~/.ssh/id_ed25519 

Verify:

ssh-add -l 

5. Add the public key to GitHub

cat ~/.ssh/id_ed25519.pub 

Copy the full output.

On GitHub:

1. Go to Settings → SSH and GPG keys
2. Click New SSH key
3. Title: rpi
4. Paste the key
5. Save

6. Configure SSH for GitHub

Create the SSH config file:

nano ~/.ssh/config 

Add:

Host github.com HostName github.com User git IdentityFile ~/.ssh/id_ed25519 IdentitiesOnly yes 

Set permissions:

chmod 600 ~/.ssh/config 

7. Test GitHub SSH access

ssh -T git@github.com 

Expected output:

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

8. Use GitHub via SSH

Clone a repository

git clone git@github.com:USER/REPO.git 

Convert an existing HTTPS repo to SSH

cd repo git remote set-url origin git@github.com:USER/REPO.git git pull 

9. Auto-load SSH key on login (optional)

Add to ~/.bashrc:

eval "$(ssh-agent -s)" >/dev/null ssh-add ~/.ssh/id_ed25519 2>/dev/null 

Reload:

source ~/.bashrc 

Troubleshooting

Permission denied (publickey)

• Ensure key is loaded: ssh-add -l
• Ensure key is added to GitHub
• Check SSH config: cat ~/.ssh/config

Fix permissions

chmod 700 ~/.ssh chmod 600 ~/.ssh/id_ed25519 chmod 644 ~/.ssh/id_ed25519.pub chmod 600 ~/.ssh/config 

Done. This system is now configured for GitHub SSH access using OpenSSH.