Generating a new SSH key and adding it to the ssh-agent & to your github account

add_ssh_key.md

Checking for existing SSH keys

Before you generate an SSH key, you can check to see if you have any existing SSH keys.
1. Open Terminal
2. Enter ls -al ~/.ssh to see if existing SSH keys are present. This lists the files in your .ssh directory, if they exist. Check the directory listing to see if you already have a public SSH key.

If you don't have an existing public and private key pair, or don't wish to use any that are available to connect to GitHub, then generate a new SSH key.

If you receive an error that ~/.ssh doesnt exist, dont worry! We will create it when we generate a new SSH key.

Generating a new SSH key

After you've checked for existing SSH keys, you can generate a new SSH key to use for authentication
1. Open Terminal
2. Enter ssh-keygen -t rsa -b 4096 -C "your_email@example.com" substituting in your GitHub email address. This creates a new ssh key, using the provided email as a label.

> Generating public/private rsa key pair.

3. When you're prompted to "Enter a file in which to save the key," press Enter. This accepts the default file location.

> Enter a file in which to save the key (/home/you/.ssh/id_rsa): [Press enter]

4. At the prompt, type a secure passphrase.

> Enter passphrase (empty for no passphrase): [Type a passphrase]
> Enter same passphrase again: [Type passphrase again]

Adding your SSH key to the ssh-agent

1. Start the ssh-agent in the background.

$ eval "$(ssh-agent -s)"
> Agent pid 59361

2. Add your SSH private key to the ssh-agent. If you created your key at a different location, or if you are adding an existing key that has a different name, replace id_rsa in the command with the name of your private key file.

$ ssh-add ~/.ssh/id_rsa

Adding SSH key to your GitHub account

1. Copy the contents of the file ~/.ssh/id_rsa.pub
2. To add the SSH key to your account, Go to:
Settings -> SSH and GPG keys -> New SSH Key
3. To add the SSH key only to a specific repository, Go to:
Your Profile -> Repositories -> Your Repository -> Settings -> Deploy Keys -> Add deploy key
4. Provide a title, paste in your public key.
5. Select Allow write access if you want this key to have write access to the repository. A deploy key with write access lets a deployment push to the repository.
6. Click Add key.

Setting your git repository to use the SSH key

Now cd to your git clone folder and:

git remote set-url origin git@github.com:username/your-repository.git