Account Setup¶
Warning
The use of SSH keys will be mandatory after February 15, 2026, and password access will no longer be available for our clusters.
Setting up your account¶
It is a fact that password-based access is the most vulnerable method to impersonation attacks, so we have decided to disable password access to our clusters.
Because of this, user accounts will not have access to any systems except account-setup.sw.ehu.es until a public key has been set up for the user.
SSH keys can be set up using the traditional method (by copying your public key into ~/.ssh/authorized_keys, as described here ) but this means that if you lose access or want to connect from a new device, you would need to contact the HPC team so we can add a new key to your account.
To avoid this inconvenience, we have implemented a system that allows you to add as many public keys as you wish directly to our authentication server. This way, you will no longer need to contact the HPC team to add new public keys.
You can check more information about how SSH public key authentication works on the following link: https://www.ssh.com/academy/ssh-keys#public-key-authentication
Warning
Adding at least one key to our authentication server is mandatory and accounts will not have access to any system until this is done.
Generating the SSH Keys in your local PC or laptop¶
To do so, you must first generate a SSH key pair in your local PC or laptop.
The easiest way to generate SSH keys is just running ssh-keygen command on a terminal (cmd or PowerShell for Windows users) as shown on the screenshot below. It will generate the keys in ~/.ssh directory by default.
1- Generate the SSH keys using the ssh-keygen command and copy the generated public key, typically on ~/.ssh/id_<key_type>.pub.
Warning
If you use a local MobaXterm session to create the SSH keys, please be sure that a persistent HOME directory has been configured in "Settings -> Configuration -> Persistent home directory" to avoid losing the created keys.
Uploading the SSH Public Key to the Authentication Server¶
1- Connect to account-setup.sw.ehu.es via SSH using your password (this is the only machine that can still be accessed using passwords), where a setup script will run automatically.
2- Add/paste your public key.
3- Add a passphrase to increase the security of your account (optional)
Once this process is complete, you will be able to connect to the same machine again, on where you will be able to manage your keys and configure additional login options, such as selecting your shell or modifying your secret passphrase.
Here is a GIF showing the full process from a Linux terminal.
If you connect to the cluster using a SSH client software/application¶
Typically, Windows users will use SSH client applications such as MobaXterm instead of the built in cmd or PowerShell to connect to our clusters.
If using a SSH client on Windows, we highly recommend using MobaXterm
As MobaXterm does not require any particular SSH key format, it is recommended to create SSH keys with cmd or PowerShellby running the ssh-keygen command as explained above.
Once they keys have been created, you must configure your MobaXterm session to use the private key in the session's settings by activating the "Use private key" option and browsing the created private key (the one without the .pub extension)
