Generating SSH Key for Authentication

Overview

1. Generate a new SSH Key
2. Start SSH Agent
3. Create Config file
4. Modify Config file
5. Add SSH key to SSH Agent
6. Add SSH key to Github Account

Generating a new SSH key

• To create a new ssh key, using the provided email as a label, execute one of the commands below substituting your Github email address

  • For modern unix operating systems

      ssh-keygen -t ed25519 -C "your_email@example.com"
    

  • For legacy unix operating using without Ed25519 support:

      ssh-keygen -t rsa -b 4096 -C "your_email@example.com"
    

• An output comparable to the below text display

    Generating public/private ed25519 key pair.
  

• Press enter upon being prompted to Enter a file in which to save the key. This accepts the default file location.

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

• Press enter upon being prompted to Enter passphrase (empty for no passphrase): [Type a passphrase].

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

Start SSH Agent

• Execute the command below to Start the ssh-agent in the background.

    eval "$(ssh-agent -s)"
  

Create SSH Config File

• Execute the command below to create a new config file.

    touch ~/.ssh/config
  

• Execute the command below to begin editing the newly created config file in nano

    nano ~/.ssh/config
  

• Paste the code below into the config file. Modify the value of the IdentityFile respectively.

  • If you chose to add a passphrase to your key, UseKeychain should be set to yes.

    Host *
      AddKeysToAgent yes
      UseKeychain no
      IdentityFile ~/.ssh/id_rsa
  

Add SSH Key to SSH Agent

• Execute the command below to add your SSH private key to the ssh-agent and store your passphrase in the keychain. Ensure id_ed25519 in the command is substituted with the name of your private key file.

   $ ssh-add -K ~/.ssh/id_rsa
  

Adding SSH Key to Github

1. Execute the command below to copy the SSH public key to your clipboard.

    $ pbcopy < ~/.ssh/id_rsa.pub
   

2. In the upper-right corner of any page, click your profile photo, then click Settings.
   

3. In the user settings sidebar, click SSH and GPG keys.
   

4. Click New SSH key or Add SSH key.

5. In the “Title” field, add a descriptive label for the new key. For example, if you’re using a personal Mac, you might call this key “Personal MacBook Air”.

6. Paste your key into the “Key” field.
   

7. Click Add SSH key.
   

8. If prompted, confirm your GitHub password.
   

Use Keychain Helper

• Execute the command below to ensure that once you are authenticated successfully, your credentials are stored in the macOS keychain and will be used each time you push or pull from an HTTPS URL.
  • git config --global credential.helper osxkeychain