SSH Key Setup for Passwordless Login

SSH keys provide a more secure and convenient way to authenticate to remote servers compared to passwords. This guide walks through setting up SSH key-based authentication from a Mac to a new server.

Generate a New Keypair

From your Mac, generate a new ED25519 keypair:

ssh-keygen -t ed25519 -C "username@servername" -f ~/.ssh/id_ed25519_servername

Change username and servername to match your environment.

Copy Your Public Key to the Server

There are many ways to do this, but a simple way is to display your new public key in the terminal and copy the text:

cat ~/.ssh/id_ed25519_servername.pub

On the server, paste it into ~/.ssh/authorized_keys as a single line.

Set the correct permissions on the server:

chmod 700 ~/.ssh
chmod 600 ~/.ssh/authorized_keys

Edit ~/.ssh/config on your Mac and add:

Host servername
    HostName servername_or_IP
    User yourusername
    IdentityFile ~/.ssh/id_ed25519_servername

Replace servername_or_IP and yourusername as needed for your new server.

Connect

You can now connect to the server with:

ssh servername

Security and convenience - no password required.

Generate a New Keypair

Copy Your Public Key to the Server

Configure SSH for Easy Login

Connect