SSH Key Authentication

These instructions assist existing users of Cheaha in getting access to new Cheaha.

Mac OS X

• On your Mac open Terminal application.
• Run the following command on your terminal:

ssh-keygen -t rsa

• You can put a passphrase for your SSH key ( Not mandatory but highly recommended)
• A id_rsa.pub file would have been created.
• Open the file by running less .ssh/id_rsa.pub and copy the content.
• Press q to exit out of the file.
• Now SSH to your cheaha.rc.uab.edu account , and paste the content in ~/.ssh/authorized_keys using your favorite editor.
• Now log out from cheaha.rc.uab.edu and login again. You shouldn't see a prompt for password and be directly logged in.

Note: You need to perform these steps just for the first time access, you should be able to directly run ssh blazerid@cheaha.rc.uab.edu from next time.

Linux

• On your linux machine open Terminal application.
• Run the following command on your terminal:

ssh-keygen -t rsa

• You can put a passphrase for your SSH key ( Not mandatory but highly recommended)
• A id_rsa.pub file would have been created.
• Open the file by running less .ssh/id_rsa.pub and copy the content.
• Press q to exit out of the file.
• Now SSH to your cheaha.rc.uab.edu account , and paste the content in ~/.ssh/authorized_keys using your favorite editor.
• Now log out from cheaha.rc.uab.edu and login again. You shouldn't see a prompt for password and be directly logged in.

Note: You need to perform these steps just for the first time access, you should be able to directly run ssh blazerid@cheaha.rc.uab.edu from next time.

Windows

Putty

You would require a tool called puttygen, to generate SSH keys for the pairing purpose. You can downlaod it here. Once you have downloaded and installed putty and puttygen, follow these instructions:

• Launch PuTTY Key Generator.

• Launch the program, click the Generate button. The program generates the keys for you.

• Enter a unique key passphrase in the Key passphrase and Confirm passphrase fields.

• Save the public and private keys by clicking the Save public key and Save private key buttons.

• Enter a unique key passphrase in the Key passphrase and Confirm passphrase fields. You will be prompted for that passphrase whenever you log in to a server with this key. (Not Mandatory, but highly recommended)

• Copy the content from the public file that you just generated by right clicking in the text field labeled Public key for pasting into OpenSSH authorized_keys file and choose Select All, right click again and select Copy

• Now open application Putty.

• Set up your session for cheaha.rc.uab.edu in PuTTy. (If you don't know how, follow these instructions).

• Login to your Cheaha account.

• Paste the content of the Public key that you generated using Puttygen in ~/.ssh/authorized_keys using your favorite editor.

• Now select your saved session for cheaha.rc.uab.edu.

• Click Connection > SSH > Auth in the left-hand navigation pane and configure the private key to use by clicking Browse under Private key file for authentication.

• Navigate to the location where you saved your private key earlier, select the file, and click Open.

• The private key path is now displayed in the Private key file for authentication field.

• Click Session in the left-hand navigation pane and click Save in the Load, save or delete a stored session section.

• Click Open to begin your session with the server. You shouldn't see a prompt for password and be directly logged in.

Note: You need to perform these steps just for the first time access, you should be able to directly run your cheaha.rc.uab.edu profile from next time.

SSH Secure Shell Client

• In SSH Secure Shell, from the Edit menu, select Settings...
• In the window that opens, select Global Settings, then User Authentication, and then Keys.
• Under "Key pair management", click Generate New.... In the window that appears, click Next.
• In the Key Generation window that appears:
  • From the drop-down list next to Key Type:, select from the following:
    • If you want to take less time to initially generate the key, select DSA.
    • If you want to take less time during each connection for the server to verify your key, select RSA.
  • From the the drop-down list next to Key Length:, select at least 1024. You may choose a greater key length, but the time it takes to generate the key, as well as the time it takes to authenticate using it, will go up.
• Click Next. The key generation process will start. When it's complete, click Next again.
• In the File Name: field, enter a name for the file where SSH Secure Shell will store your private key. Your public key will be stored in a file with the same name, plus a .pub extension.
  • Important: You can put a passphrase for your SSH key ( Not mandatory but highly recommended)
• To complete the key generation process, click Next, and then Finish.
• At the Settings screen, click OK.
• Copy the content of .pub file generated.
• Now SSH to your cheaha.rc.uab.edu account, following the instructions here , and paste the content in ~/.ssh/authorized_keys using your favorite editor.
• Now exit/logout from your account on cheaha.uabgrid.uab.edu and login again. You shouldn't see a prompt for password and be directly logged in.

Note: You need to perform these steps just for the first time access, you should be able to directly run your cheaha.rc.uab.edu profile from next time.