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

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" go to step
2. Otherwise, you already have an existing keypair, and you can skip to step
3.

Step 2: 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 "your_email@example.com"# Creates a new ssh key using the provided email
# Generating public/private rsa key pair.
# Enter file in which to save the key (/home/you/.ssh/id_rsa):

Now you need to enter a passphrase.

Why
do passphrases matter?

Passwords aren't very secure, you already know this. If you use one that's easy to remember, it's easier to guess or brute-force (try many options until one works). If you use one that's random it's hard to remember, and thus you're more inclined to write the
password down. Both of these are Very Bad Things™. This is why you're using ssh keys.

But using a key without a passphrase is basically the same as writing down that random password in a file on your computer. Anyone who gains access to your drive has gained access to every system you use that key with. This is also a Very Bad Thing™. The solution
is obvious: add a passphrase.

But I don't want to enter a long
passphrase every time I use the key!

Neither do we! Thankfully, there's a nifty little tool called ssh-agent that can save your passphrase securely so you don't have to re-enter it. Most
linux installations will automatically start ssh-agent for you when you log in.

For more information about SSH key passphrases, check out our help
guide.

# 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 /home/you/.ssh/id_rsa.
# Your public key has been saved in /home/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 your_email@example.com

Step 3: Add your SSH key to GitHub

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

sudo apt-get install xclip# Downloads and installs xclip. If you don't have `apt-get`, you might need to use another installer (like `yum`)

xclip -sel clip < ~/.ssh/id_rsa.pub# Copies the contents of the id_rsa.pub file to your clipboard

  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 4: 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 git@github.com part.
That's supposed to be there.

ssh -T git@github.com# 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.