Connect to Github with a SSH key

Quick step-by-step guide:

Generate a new SSH key:

ssh-keygen -t ed25519 -C "[email protected]"

Note: you can use your github email address

Add the key to the ssh-agent:

eval "$(ssh-agent -s)"; ssh-add ~/.ssh/id_ed25519

option	desc.
-t	type Specifies the type of key to create.
-C	add a comment (usualy the email address)
-f	filename Specifies the filename of the key file.

Configure Git and Github

• Copy the public key:

cat ~/.ssh/id_ed25519.pub

• Set git key format

git config --global --unset gpg.format
git config --global gpg.format ssh

• Add the public key to your GitHub account (Settings > SSH and GPG keys > New SSH key)

• Configure Git to use the SSH key:

git config --global user.signingkey ~/.ssh/id_ed25519

(Note: this step is not necessary if you're using SSH keys, but rather GPG keys. For SSH keys, you can simply use git commit -S to sign your commits)

Test your newly created key on the github server

ssh -T [email protected]

You should receive this answer:

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

How to sign a commit?

git commit -S -m "Your commit message"

Optional

Start your SSH-agent automatically

Add this script to a ~/.ssh/ssh-agent-start.sh file.

~/.ssh/ssh-agent-start.sh

SSH_ENV="$HOME/.ssh/agent-environment"

function start_agent {
    echo "Initialising new SSH agent..."
    /usr/bin/ssh-agent | sed 's/^echo/#echo/' >"$SSH_ENV"
    echo succeeded
    chmod 600 "$SSH_ENV"
    . "$SSH_ENV" >/dev/null
    /usr/bin/ssh-add;
}

# Source SSH settings, if applicable

if [ -f "$SSH_ENV" ]; then
    . "$SSH_ENV" >/dev/null
    #ps $SSH_AGENT_PID doesn't work under Cygwin
    ps -ef | grep $SSH_AGENT_PID | grep ssh-agent$ >/dev/null || {
        start_agent
    }
else
    start_agent
fi

Execute:

chmod +x ~/.ssh/ssh-agent-start.sh

Add to your ~/.bashrc file

. ~/.ssh/ssh-agent-start.sh