View source for Creating And Using SSH Public Keys

[[Category:Linux]]

SSH Public Keys can allow you to make a secure connection over sshd to a remote host, without pausing to give a password.  To do this, a public key must be created, placed on the remote server, and finally, the key must be imported into the ~/.ssh/authorized_keys2 file.

Create your public/pricate key pair/
 [jhorne@local ~]$ ssh-keygen -t rsa
This will take a moment to generate the pair, and it will ask you to enter a pass phrase.  Do not enter a pass phrase, but instead, just hit enter to create a blank passphrase.  The files will be created in your ~/.ssh directory.  They should look like this:
 [jhorne@local ~]$ ls .ssh/
 id_rsa          id_rsa.pub

IF YOURE USING RedHat or Fedora or CentOS, then just do this next step and skip the rest:
 ssh-copy-id remote
this command will place your key on the remote server with the proper folder and file permissions. 9 out of 10 times, ssh-key issues are permissions issues :)  (they should be 700 and 600, respectively).

If you're using some other Unix, then read on.  :)

Next, move the id_rsa.pub to your target remote server.  Use scp, sftp, or whatever method you need to move the file to the remote.  I usually just put it right in the homedir on the remote server.  Once its, there, import it into the authorized_keys file like this:
 [jhorne@remote ~]$ cat id_rsa.pub >> .ssh/authorized_keys
Once this is done, then from the local server, you can ssh to the remote server without a password.
 [jhorne@local ~]$ ssh remote
 Last login: Sun Jun  4 10:21:15 2006 from local.
 [jhorne@remote ~]$
The id_rsa.pub file that you moved to your homedir on the other server, should now be deleted.