I find myself always having to search for the steps to do key authentication for ssh. This post is to be a personal quick reminder of the required steps. See link here for a more detailed walk through.

  1. Generate private/public key pair on the local computer.

    ssh-keygen -t rsa -b 4096

    The 4096 is just for a longer key for security reasons. By default, this stores the keys at ~/.ssh in the files id_rsa and id_rsa.pub.

  2. Transfer the public key to the remote computer that you are attempting to ssh into.

    ssh-copy-id user@host

    You’ll need to enter in the user’s password at this step. If all goes according to plan, at this point, you should be able to do ssh user@host and not enter in a password.

  3. Give the hostname/IP address an alias so that it is easier to remember.

    You can alias the IP address for ssh using the ~/.ssh/config file. For example, to ssh into the server that hosts my psychrometric chart page, I have the following lines (not the actual IP address).

Host psy
    User root

With those lines added to the ~/.ssh/config file, I can now use the command

ssh psy

and I’m in.