GitHub SSH Key Setup Guide

This guide provides a clear, step-by-step workflow to generate, register, and use SSH keys with GitHub for secure passwordless authentication.

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🔐 1. Check Existing SSH Keys

Before creating a new key, check whether your system already has one:

ls ~/.ssh

If you see files like:

• id_rsa / id_rsa.pub

• id_ed25519 / id_ed25519.pub

You already have SSH keys.

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🗝 2. Generate a New SSH Key

GitHub recommends the modern ed25519 algorithm:

ssh-keygen -t ed25519 -C "[e-mail]"

Press Enter to accept defaults.

Your keys will be saved to:

• ~/.ssh/id_ed25519

• ~/.ssh/id_ed25519.pub

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🔧 3. Start the SSH Agent

Make sure the agent is running:

eval "$(ssh-agent -s)"

Add your private key:

ssh-add ~/.ssh/id_ed25519

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📋 4. Add Public Key to GitHub

Copy the contents of your public key:

cat ~/.ssh/id_ed25519.pub

Go to: GitHub → Settings → SSH and GPG Keys → New SSH Key

Paste the key content.

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🛰 5. Verify SSH Authentication

Test connection:

ssh -T [e-mail]

Success message:

Hi username! You've successfully authenticated...

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🔄 6. Convert Repository Remote URL to SSH

If your repo is using HTTPS, change it:

git remote set-url origin [e-mail]:USERNAME/REPOSITORY.git

Check result:

git remote -v

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🚀 7. Push Using SSH

Now pushing won't require a username or password:

git push

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🧰 Optional: SSH Config for Multiple Keys

Create or edit config file:

nano ~/.ssh/config

Example setup:

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

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✅ Summary

With SSH keys set up, you can:

• Push & pull without typing username/password

• Securely authenticate to GitHub

• Use multiple repos and accounts smoothly

Your Git workflow becomes faster and more secure.

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If you'd like, I can also add:

• Windows + WSL2 SSH setup

• Multi-account GitHub SSH setup

• Auto script to convert all local repos to SSH URLs.