Open your terminal

Generate new SSH key

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

terminal will prompt:

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

Most ssh key are stored under /Users/you/.ssh directory, unless you understand what you are doing.

id_rsa is the default private key used in SSH connection.

note:

If you find this file already exists, then you can choose another name or type y to overwrite the file (BE CAREFUL: you may affect softwares rely on this file).

If you change the file name, type in something like /Users/you/.ssh/your_choosen_name_rsa.

type a secure passphrase (add an extra layer of security)

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

Add to your service account keys list

In your terminal

cd /Users/you/.ssh/

copy content from /Users/you/.ssh/your_choosen_name_rsa.pub and paste to ssh key list in your service accout setting (like https://github.com/settings/ssh/new).

Add to SSH Agent

Start the ssh-agent in the background.

eval "$(ssh-agent -s)"

macOS: ssh-add -K ~/.ssh/your_choosen_name_rsa (add key to keychain)

Linux: ssh-add ~/.ssh/your_choosen_name_rsa

Test your ssh key setting

ssh -T git@github.com

If everything goes well, your will see:

Hi YOUR_GITHUB_NAME! You’ve successfully authenticated, but GitHub does not provide shell access.

Reset passphase

ssh-keygen -p

Reference:

• https://help.github.com/en/github/authenticating-to-github/about-ssh
• https://help.github.com/en/github/authenticating-to-github/generating-a-new-ssh-key-and-adding-it-to-the-ssh-agent
• https://help.github.com/en/github/authenticating-to-github/working-with-ssh-key-passphrases
• https://kb.iu.edu/d/aeww
• https://linuxize.com/post/using-the-ssh-config-file/