SSH Keys

SSH keys are required to access the UCHC HPC system. This page will walk you through the process of creating and using SSH keys to access the UCHC HPC system.

SSH keys are a secure authentication method that can be used for remote access to a server without using passwords. It is in fact a more secure authentication method than using a password. SSH keys consist of a pair of cryptographic keys — a private key kept secret on your computer and a public key placed on the remote server you want to access.

To be able to login using SSH keys, you will need to:

  1. Create an SSH key pair on your local computer.
  2. Copy the public key to the UCHC HPC system.

Only ed25519 keys are accepted.

1. Create SSH keys

You can create a public and private SSH key pair using your SSH client in Windows PowerShell or a MacOS / Linux Terminal.

  1. First check for an existing SSH key pair by running the following command:
ls ~/.ssh/
ls $env:USERPROFILE\.ssh\

If you see files named id_ed25519.pub and id_ed25519, you already have an SSH key pair and can skip ahead to step the Copy key to UCHC HPC system section. If you do not see these files or get an error message, you will need to create a new SSH key pair.

  1. To create a key pair run the following command:
ssh-keygen -t ed25519 -C <comment>

Replacing <comment> with something to help you identify which computer this key pair was created for. For example: laptop

  1. You will be prompted to specify the location to save the key. You can press enter to accept the default location.
  2. Next you will be prompted to create a passphrase which is optional. If you don’t wish to create a passphrase, simply press enter.
Warning

Do not share your private key with anyone! Your private key should be kept secret and secure on your computer. If someone else has access to your private key, they can access the UCHC HPC system as you. We will never ask you for your private key for any reason.

2. Copy Public SSH Key to the UCHC HPC system

Once you have created your SSH key pair, you will need to copy the public key to the UCHC HPC system. This can only be done through the Open OnDemand web portal. To copy your public key to the UCHC HPC system, follow the steps below:

1. Copy your public key.

Your public key will be located in the ~/.ssh/ directory located inside of your user home directory. Select your operating system below for instructions on how to copy your public key to your clipboard.

On MacOS or Linux operating systems, you can easily copy the public key to your clipboard by running the following command in the terminal application:

pbcopy < ~/.ssh/id_ed25519.pub

On Windows operating systems, you can easily copy the public key to your clipboard by running the following command in the PowerShell application:

Get-Content "$env:USERPROFILE\.ssh\id_ed25519.pub" | Set-Clipboard

2. Log in to Open OnDemand

See the Open OnDemand page for more information about logging in.

3. Click the “Files” dropdown menu and under “Utilities” select “SSH Key Manager”.

4. Paste your key into the “Add a key” text box.

5. Click the “Add Key” button.

Keys can be removed at any time by clicking the “Remove” button next to the key you wish to remove.