Using Temporary Public Key Authentication with OpenSSH

Notes:

• This only works with OpenSSH clients at the present time. There is an issue with key formats for other clients. (Can also be made to work with PuTTY if you use PuTTYgen to convert the keys into PuTTY’s format)
• OpenSSH is available for Linux, Mac OS X and Windows using Cygwin.
• There have also been issues with some browsers. Mozilla 1.2.1 under Linux seems to fail when downloading the keys (the file is 0 bytes).
• The examples are for Windows, but other OS types should behave in a similar manner
• The key pair is only valid for 8 hours. After this time you will have to generate a new set. This will not close existing connections.

Steps:

1. Go to https://research.rutgers.edu/mkrussh.html. You may see something like the following (these examples are from IE 6 and Netscape 4.8):

Just click “Yes” to continue in IE. Click “Next” in Netscape/Mozilla. In Netscape/Mozilla you will be prompted by a few more screens, just follow the directions.

2. After accepting the certificate. You should see the following:

Type your username and password in the appropriate fields and click “Generate Keys”.

3. If successful, your browser should present you with a box prompting you to download a zip file called “id_rsa.zip”. For example:

Click Save. You will then be prompted for where to save the file (Remember where you save the file!):

Navigate to where you want to store the file on your local machine (I recommend your home directory under cygwin). Click Save.

4. Open a command prompt on your local machine:

• Windows – click the Cygwin icon to start up a shell
• OS X – open a “Terminal” session
• Linux/Unix – open a terminal in your usual manner

5. At the prompt, type:

unzip <path-to-zip-file>

You should now have a directory called mkrussh in your current directory. In this directory are 2 files, id_rsa (private key) and id_rsa.pub (public key). These need to be put in the appropriate location. For OpenSSH (assuming the existence of the .ssh directory in your home directory):

• Copy id_rsa to ~/.ssh/ (this will overwrite any existing key, be careful!)
• Append id_rsa.pub to ~/.ssh/authorized_keys (in UNIX/Linux: cat id_rsa.pub >> ~/.ssh/authorized keys

6. ssh to research.rutgers.edu. There is no passphrase on the keys generated, so you should be logged in automatically.

Email help@research.rutgers.edu if you have any questions or problems.