These instructions are the minimal steps necessary to set up your linux lab environment so that, once you are logged in to one lab machine, you can log into any other lab machine without entering a password. There are more detailed instructions for using ssh keys available; these ones are the least you need to know. They assume that you haven’t already set up any ssh keys or done any other ssh configuration that you don’t want changed.

  1. Log into any linux lab machine using your UW NetID and password.
  2. If you are using a graphical session, launch a Terminal from Applications → System Tools.
  3. Run the following commands (copy and paste if possible):
$ mkdir -p ~/.ssh
$ chmod 0700 ~/.ssh
$ ssh-keygen -t rsa -b 4096 -f ~/.ssh/id_rsa -N ""
$ cp ~/.ssh/id_rsa.pub ~/.ssh/authorized_keys
$ chmod 0600 ~/.ssh/authorized_keys
# You will need to answer "Yes" when you connect to different machines

# Below command no longer works
# cp /net/metis/usr/apps/known_hosts ~/.ssh/

You can now ssh between any of the Linux lab machines without having to enter a password.

 

Do not use the ssh key you just created for anything else. Since this key has no associated password, anyone who manages to get a copy of the private key will be able to log in as you to any system that accepts the key. If you accidentally change your file permissions so that someone else on the system can read your private key, you will be protected internally because of the misconfiguration—ssh won’t allow you to log in using the key if the permissions are wrong—but any remote systems you configured to use that key will be wide open.