Linux: SSH Key Setup

Overview

This article provides details and specifics for how to set up a SSH key to connect to ARCC HPC Clusters from a Linux OS PC. Each key is associated with your identity on that HPC resource, therefore you do not need to create a new key for every client you use to ssh into the HPC.

If you’d like to configure a specific SSH connection application in Linux OS specific directions may be found below:

Configuring SSH Key Authentication in CyberDuck for Mac

Creating and Managing your SSH Keys with the SSH Key Manager

To set up access:

First, log into the OnDemand resource for the HPC you want to set up SSH keys for.
1. For MedicineBow, log in at https://medicinebow.arcc.uwyo.edu/. Step-by-step directions for logging into MedicineBow OnDemand are available here.
2. For WildIris, log in at https://https://wiodm01.arcc.uwyo.edu/. Step-by-step directions for logging into WildIris OnDemand are available here.
Once you’re logged in, you should be presented with the HPC Dashboard. Click the following icon to set up SSH key authentication:
Each key is associated with your identity, therefore you do not need to create a new key for every client you use to ssh into the HPC.
If you haven’t set up an SSH key previously, you should see an empty screen/list with the option to generate a new a key. Click that button if you need to set up a key.
Doing this will create a new set of files associated with your login to the HPC.
If you’ve already created a key previously you don’t need another one. Skip this step and download a key you’ve already generated for your account as described in the next step.
Click the download button associated with the key ID for your ssh key to download them to your client/computer.

Please be careful with these files. Do not change their permissions, put them in an insecure digital location, or share them with others. They are your “virtual keys” to log in as yourself on the HPC. If provided to or shared with others, they will be able to log into that ARCC HPC resource as you

Configure keys on your Linux Box

a. Check to see if you have a .ssh directory already created on your system. If it shows up in the list, skip step b.
```
cd ~
ls -lah
```
b. If your .ssh directory does not exist in the list use ssh-keygen to create the folder and set permissions appropriately:
```
ssh-keygen -t rsa
```
Use the default location to store the key by hitting Enter. A key pair will be generated.
c. You will then be asked to create a passphrase. If you would like to create one, put that in now, and make note of it, since it will be required later. Otherwise, hit Enter to accept the default with no passphrase.
d. Unzip the files associated with your login to your .ssh folder:
```
unzip <username>.zip -d ~/.ssh/
```
e. Test configuration. Open up a new terminal/command line window and log into <cluster>. If configured properly, you will be logged in automatically, and will not be prompted for a password (first factor), nor second factor authentication for login.