Using SSH Keys

To access the various FutureSystem resources, you need to provide a public ssh key to FutureSystem. We explain how to generate a ssh key, upload it to the FutureSystem portal and log onto the resources. This manual covers UNIX, Mac OS X, and Windows Users.

Using SSH from Windows


info-image For Linux users, please skip to the section Generate a SSH key


info-image For Mac users, please skip to the section Using SSH on Mac OS X

Windows users need to have some special software to be able to use the SSH commands. If you have one that you are comfortable with and know how to setup key pairs and access the contents of your public key, please feel free to use it. The most popular software making ssh clients available to Windows users include

For a real quick start we recommend you use Cygwin (Linux-like environment for Windows) because it will ease your experience with FutureSystem and provide you with a command shell that is Linux like. If you have cygwin already installed, please use it, but make sure you have ssh installed. If not, we have made it even easier for you as we prepared a special Cygwin version that is ready to use. Once you have installed it, you can follow the same instructions as given in the rest of the sections presented to access FutureSystem from ssh. You can install cygwin it with the following simple steps.

Step Description Supporting Screenshot
Step 1 Download Cygwin from our Portal :portal:`sites/default/files/`.  
Step 2 Uncompress the file. image21
Step 3 Execute the file the ‘Windows Batch File’ called Cygwin.bat  
Step 4 You may get a warning. Click on the Run button image22
Step 5 You get a Linux-like terminal that will allow you to continue with this manual. Hint: When showing examples of commands, the $ symbol precedes the actual command. So, the other lines are the output obtained after executing the command. image23

Using SSH on Mac OS X

Mac OS X comes with an ssh client. In order to use it you need to open the application. Go to Finder, then click Go in the menu bar at the top of the screen. Now click Utilities and then open the Terminal application.

Generate a SSH key

First we must generate a ssh key with the tool ssh-keygen. This program is commonly available on most UNIX systems (this includes Cygwin if you installed the ssh module or use our pre-generated cygwin executable). It will ask you for the location and name of the new key. It will also ask you for a passphrase, which you MUST provide. Some teachers and teaching assistants advice you to not use passphrases. This is WRONG as it allows someone that gains access to your computer to also gain access to all resources that have the public key. Also, please use a strong passphrase to protect it appropriately.

In case you already have a ssh key in your machine, you can reuse it and skip this whole section.

To generate the key, please type:


ssh-keygen -b 2048 -t rsa -C

This command requires the interaction of the user. The first question is:

Enter file in which to save the key (/home/localname/.ssh/id_rsa):

We recommend using the default location ~/.ssh/ and the default name id_rsa. To do so, just press the enter key.

The second and third question is to protect your ssh key with a passphrase. This passphrase will protect your key because you need to type it when you want to use it. Thus, you can either type a passphrase or press enter to leave it without passphrase. To avoid security problems, you MUST chose a passphrase. Make sure to not just type return for an empty passphrase:

Enter passphrase (empty for no passphrase):


Enter same passphrase again:

If executed correctly, you will see some output similar to:

Generating public/private rsa key pair.
Enter file in which to save the key (/home/localname/.ssh/id_rsa):
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved in /home/localname/.ssh/id_rsa.
Your public key has been saved in /home/localname/.ssh/
The key fingerprint is:
The key's random art image is::

+--[ RSA 2048]----+
|.+...Eo= .       |
| ..=.o + o +o    |
|O.  o o +.o      |
| = .   . .       |

Once, you have generated your key, you should have them in the .ssh directory. You can check it by

$ cat ~/.ssh/

If everything is normal, you will see something like:

ssh-rsa AAAAB3NzaC1yc2EAAAADAQABAAABAQCXJH2iG2FMHqC6T/U7uB8kt6KlRh4kUOjgw9sc4Uu+Uwe/EwD0wk6CBQMB+HKb9upvCRW/851UyRUagtlhgythkoamyi0VvhTVZhj61pTdhyl1t8hlkoL19JVnVBPP5kIN3wVyNAJjYBrAUNW4dXKXtmfkXp98T3OW4mxAtTH434MaT+QcPTcxims/hwsUeDAVKZY7UgZhEbiExxkejtnRBHTipi0W03W05TOUGRW7EuKf/4ftNVPilCO4DpfY44NFG1xPwHeimUk+t9h48pBQj16FrUCp0rS02Pj+4/9dNeS1kmNJu5ZYS8HVRhvuoTXuAY/UVcynEPUegkp+qYnR

Add or Replace Passphrase for an Already Generated Key

In case you need to change your change passphrase, you can simply run “ssh-keygen -p” command. Then specify the location of your current key, and input (old and) new passphrases. There is no need to re-generate keys:

ssh-keygen -p

You will see the following output once you have completed that step:

Enter file in which the key is (/home/localname/.ssh/id_rsa):
Enter old passphrase:
Key has comment '/home/localname/.ssh/id_rsa'
Enter new passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification has been saved with the new passphrase.

Upload the key to the FutureSystem Portal

Next you need to upload the key to the portal. You must be logged into the portal to do so.

Step Description Supporting Screensho
Step 1 Log into the portal image25
Step 2 Click in the “ssh key” button. or go directly to image26
Step 3 Click in the “add a public key” link. image27
Step 4 Paste your ssh key into the box marked Key. Use a text editor to open the “”. Copy the entire contents of this file into the ssh key field as part of your profile information. Many errors are introduced by users in this step as they do not paste and copy correctly. image28
Step 5 Click the submit button. IMPORTANT: Leave the Title field blank. Make sure that when you paste your key, it does not contain newlines or carriage returns that may have been introduced by incorrect pasting and copying. If so, please remove them.  

At this point you have uploaded your key. However you will still need to wait till all accounts have been set up to use the key, or if you did not have an account till it has been created by an administrator. Please, check your email for further updates. You can also refresh this page and see if the boxes in your account status information are all green. Than you can continue.

Testing your ssh key

If you have had no FutureSystem account before, you need to wait for up to two business days so we can verify your identity and create the account. So please wait. Otherwise, testing your new key is almost instantaneous on india. For other clusters like it can take around 30 minutes to update the ssh keys.

To log into india simply type the usual ssh command such as:

$ ssh

The first time you ssh into a machine you will see a message like this:

The authenticity of host ' (' can't be established.
RSA key fingerprint is 11:96:de:b7:21:eb:64:92:ab:de:e0:79:f3:fb:86:dd.
Are you sure you want to continue connecting (yes/no)? yes

You have to type yes and press enter. Then you will be logging into india. Other FutureSystem machines can be reached in the same fashion. Just replace the name india, with the appropriate FutureSystems resource name.