git-ssh-generate

Generating an SSH key pair

The first step in using SSH authorization with GitHub is to generate your own key pair.

You might already have an SSH key pair on your machine. You can check to see if one exists by moving to your .ssh directory and listing the contents.

$ cd ~/.ssh
$ ls

If you see id_rsa.pub, you already have a key pair and don't need to create a new one.

If you don't see id_rsa.pub, use the following command to generate a new key pair. Make sure to replace your@email.com with your own email address.

$ ssh-keygen -o -t rsa -C "your@email.com"

(The -o option was added in 2014; if this command fails for you, just remove the -o and try again)

When asked where to save the new key, hit enter to accept the default location.

Generating public/private rsa key pair.
Enter file in which to save the key (/Users/username/.ssh/id_rsa):

You will then be asked to provide an optional passphrase. This can be used to make your key even more secure, but for this lesson you can skip it by hitting enter twice.

Enter passphrase (empty for no passphrase):

Enter same passphrase again:

When the key generation is complete, you should see the following confirmation:

Your identification has been saved in /Users/username/.ssh/id_rsa.
Your public key has been saved in /Users/username/.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.com
The key's randomart image is:
+--[ RSA 2048]----+
|                 |
|                 |
|        . E +    |
|       . o = .   |
|      . S =   o  |
|       o.O . o   |
|       o .+ .    |
|      . o+..     |
|       .+=o      |
+-----------------+

The random art image is an alternate way to match keys but we won't be needing this.
Add your public key to GitHub

We now need to tell GitHub about your public key. Display the contents of your new public key file with cat:

$ cat ~/.ssh/id_rsa.pub

The output should look something like this:

ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEA879BJGYlPTLIuc9/R5MYiN4yc/YiCLcdBpSdzgK9Dt0Bkfe3rSz5cPm4wmehdE7GkVFXrBJ2YHqPLuM1yx1AUxIebpwlIl9f/aUHOts9eVnVh4NztPy0iSU/Sv0b2ODQQvcy2vYcujlorscl8JjAgfWsO3W4iGEe6QwBpVomcME8IU35v5VbylM9ORQa6wvZMVrPECBvwItTY8cPWH3MGZiK/74eHbSLKA4PY3gM4GHI450Nie16yggEg2aTQfWA1rry9JYWEoHS9pJ1dnLqZU3k/8OWgqJrilwSoC5rGjgp93iu0H8T6+mEHGRQe84Nk1y5lESSWIbn6P636Bl3uQ== your@email.com

Copy the contents of the output to your clipboard and add it on you git/github settings/ssh keys