Creating an SSH key

When applying for an account you need to supply an SSH public key. This key will allow you to log in securely to the community server.

SSH logins can be done with just a password, but using keys is more secure and so we only permit logins to the community server using ssh keys. It is also more convenient because it allows you to log in without being interrupted to type a password. This is important for when using darcs to push patches to a repository on the server.

UNIX-like OSes (e.g. Linux, Mac OS X, *BSD)

You may already have an SSH key. If so, it will live in the file ~/.ssh/ or ~/.ssh/

If don't already have an SSH key now is the time to make one! It is quite simple. You will run a command that will create both a public and a private key. These will be saved in the files ~/.ssh/ and ~/.ssh/id_dsa respectively. You will then supply us with the public key and keep the private key secret.

So all you have to do is to run the command

ssh-keygen -t dsa
and press enter a few times to accept all the default options. In particular you should accept the default locations for the key files and it is perfectly ok to make a key that needs no password. Let's see an example (for a hypothetical user 'foo' on a machine 'bar'):

        foo@bar ~ $ ssh-keygen -t dsa
        Generating public/private dsa key pair.
        Enter file in which to save the key (/home/foo/.ssh/id_dsa):
        Enter passphrase (empty for no passphrase): 
        Enter same passphrase again: 
        Your identification has been saved in /home/foo/.ssh/id_dsa.
        Your public key has been saved in /home/foo/.ssh/
        The key fingerprint is:
        53:a8:02:54:f3:76:e9:9a:ed:5a:91:43:1c:7e:5e:69 foo@bar

So now all you have to do is look at the contents of your newly generated ~/.ssh/ and paste it into the "SSH public key" box on the account request page.


The puttygen.exe program generates SSH keys. The test in the "Public key for pasting into OpenSSH authorized_keys file" box is what you need to paste into the "SSH public key" box on the account request page.