If you have decided not to use the recommended HTTPS method, we can use SSH keys to establish a secure connection between your computer and GitHub. The steps below will walk you through generating an SSH key and then adding the public key to your GitHub account.

Step 1: Check for SSH keys

Have an existing keypair you'd like to use? You can skip to Step 4.

First, we need to check for existing ssh keys on your computer. Open up Terminal and run:

cd ~/.ssh# Checks to see if there is a directory named ".ssh" in your user directory

If it says "No such file or directory" skip to step 3. Otherwise continue to step 2.

Step 2: Backup and remove existing SSH keys

Since there is already an SSH directory you'll want to back the old one up and remove it:

ls# Lists all the subdirectories in the current directory
# config  id_rsa  id_rsa.pub  known_hosts

mkdir key_backup# Makes a subdirectory called "key_backup" in the current directory

cp id_rsa* key_backup# Copies the id_rsa keypair into key_backup

rm id_rsa*# Deletes the id_rsa keypair

Step 3: Generate a new SSH key

To generate a new SSH key, enter the code below. We want the default settings so when asked to enter a file in which to save the key, just press enter.

ssh-keygen -t rsa -C "[email protected]"# Creates a new ssh key using the provided email
# Generating public/private rsa key pair.
# Enter file in which to save the key (/Users/you/.ssh/id_rsa): [Press enter]

Now you need to enter a passphrase.

Why do passphrases matter?

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

Which should give you something like this:

# Your identification has been saved in /Users/you/.ssh/id_rsa.
# Your public key has been saved in /Users/you/.ssh/id_rsa.pub.
# The key fingerprint is:
# 01:0f:f4:3b:ca:85:d6:17:a1:7d:f0:68:9d:f0:a2:db [email protected]

Step 4: Add your SSH key to GitHub

Run the following code to copy the key to your clipboard.

pbcopy < ~/.ssh/id_rsa.pub# Copies the contents of the id_rsa.pub file to your clipboard

Be warned: it is important to copy the key exactly without adding newlines or whitespace. Thankfully the pbcopy command makes it easy to perform this setup perfectly.

  1. Go to your Account Settings
  2. Click "SSH Keys" in the left sidebar
  3. Click "Add SSH key"
  4. Paste your key into the "Key" field
  5. Click "Add key"
  6. Confirm the action by entering your GitHub password

Step 5: Test everything out

To make sure everything is working you'll now SSH to GitHub. When you do this, you will be asked to authenticate this action using your password, which for this purpose is the passphrase you created earlier. Don't change the [email protected] part. That's supposed to be there.

ssh -T [email protected]# Attempts to ssh to github

You may see this warning:

# The authenticity of host 'github.com (207.97.227.239)' can't be established.
# RSA key fingerprint is 16:27:ac:a5:76:28:2d:36:63:1b:56:4d:eb:df:a6:48.
# Are you sure you want to continue connecting (yes/no)?

Don't worry, this is supposed to happen. Verify that the fingerprint matches the one here and type "yes".

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

If that username is correct, you've successfully set up your SSH key. Don't worry about the shell access thing, you don't want that anyway.

If you see "access denied" please consider using HTTPS instead of SSH. If you need SSH start atthese instructions for diagnosing the issue.