Using SSH keys to connect to a server

This is a simple one, but one I keep forgetting.

Generating keys

SSH keys can be generated with the ssh-keygen command. The key type can be specified of key using the -t argument followed by the name of the type [ ecdsa | ecdsa-sk | ed25519 | ed25519-sk | rsa ].

From inside the ~/.ssh/ folder, generate an ed25519 key:

ssh-keygen -t ed25519

Configuring ssh to use a key

Running ssh-keygen creates a private key and a public key (.pub). The ~/.ssh/config file can be edited in order to tell ssh which private key to use for each host:

Host <<ip/link to your server>>
    IdentityFile ~/.ssh/<<myprivatekey>>

In this example, ssh will use the private key at ~/.ssh/niliaranet file when connecting to niliara.net:

Host niliara.net
    IdentityFile ~/.ssh/niliaranet

Authorizing keys

The server should recognise the client after adding the contents of the public key (.pub) in a new line inside the server’s ~/.ssh/authorized_keys file.

Once that’s done, the server should allow access to the client without prompting for a password.