Generating SSH keys

To identify a trusted computer, without involving passwords, ssh keys are used. The steps below will walk you through generating an ssh key to allow you to authenticate with the Nemo project.

Step 1: Check for existing ssh keys

First, check for existing ssh keys on your computer. Provided you're using Unix or Gnu/Linux, open the CLI and enter:

ls -al ~/.ssh

This will lists the files in your .ssh directory, if they exist.

Check the directory listing to see if you already have a public ssh key. By default, the filenames of the public keys are one of the following:

  • id_dsa.pub
  • id_ecdsa.pub
  • id_ed25519.pub
  • id_rsa.pub

If you see an existing public and private key pair listed (for example id_rsa.pub and id_rsa) that you would like to use to authenticate with the Nemo project, you can skip step 2 and go straight to step 3.

Step 2: Generate a new ssh key

If you don't have a public key, you can generate one with this command:

ssh-keygen -t rsa -b 4096

It is recommended that you use a passphrase. That means that somebody with physical access to computer cannot login without knowing the passphrase.

Step 3: Install you public key on bar

ssh-copy-id username@bar.nemo-project.org

Login on bar.nemo-project.org using ssh to verify that works. Check .ssh/authorized_keys to make sure no rogue keys are present.

Read more

Ubuntu documentation: Public and Private Keys.