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I’ve been using SSH certificates for years to connect to my servers no matter where they are, and they’ve always worked perfectly. I’ve used both client and server certificates, but since I automated the setup I sometimes forget the steps. This guide records the process for future reference.

What is SSH Certificates?

Just as HTTPS certificates verify our websites, SSH certificates confirm the identity of both server and user before any connection begins. When you first connect to a new SSH server, you’ve no doubt seen that warning about an unknown host key and clicked “yes” because you just created the machine and assume it’s safe. SSH certificates remove that guesswork. A trusted authority signs the server’s public key in advance, and your client automatically checks that signature on every connection. On the flip side, the server only accepts user keys that carry a valid signature from the same authority. Certificates can include expiration dates and be revoked if necessary, giving you precise control over who can connect and for how long. With SSH certificates in place, there’s no need to blindly trust that initial prompt.

Once your server is up and running, you can configure a peer. The process is nearly identical to setting up the server—allowing you to easily replicate these steps for adding multiple peers. As always, ensure that all commands are executed as the root user.

Generate keys

Each peer requires a unique public/private key pair to establish identity and secure connections, just like the server . Run the following commands to create the required files:

Refer to this article for a brief overview, prerequisites, and server details. Ensure you run all commands as the root user.

Generate keys

Each server requires a unique public/private key pair to establish identity and secure connections. Run the following commands to create the required files:

(umask 0077; wg genkey | sudo tee /etc/wireguard/privatekey | wg pubkey | sudo tee /etc/wireguard/publickey)
wg genpsk   # Generates a preshared key for Peer A (adds an extra layer of encryption)

Create configuration file

Create a configuration for the new interface. In Wireguard, the configuration file’s name determines the interface name. For example, if you create /etc/wireguard/wg0.conf, the interface will be named wg0.