18.5 SSH Key-based Authentication from Linux and macOS Clients

The first step in setting up SSH key-based authentication is to generate the key pairs on the client system. If the client system is running Linux or macOS, this is achieved using the ssh-keygen utility:

# ssh-keygen

This will result in output similar to the following:

Generating public/private rsa key pair.

Enter file in which to save the key (/home/<username>/.ssh/id_rsa):

Press the Enter key to accept the default location for the key files. This will place two files in the .ssh sub-directory of the current user’s home directory. The private key will be stored in a file named id_rsa while the public key will reside in the file named id_rsa.pub.

Next, ssh-keygen will prompt for a passphrase with which to protect the private key. If a passphrase is provided, the private key will be encrypted on the local disk and the passphrase required in order to gain access to the remote system. For better...