Month: December 2013

Set up SSH keys – avoid typing password every time

On the local machine, type the BOLD part. The non-bold part is what you might see as output or prompt.

  • Step 1:
    % ssh-keygen -t dsa
    Generating public/private dsa key pair.
    Enter file in which to save the key (~/.ssh/id_dsa):     (just type return)
    Enter passphrase (empty for no passphrase):     (just type return)
    Enter same passphrase again:     (just type return)
    Your identification has been saved in ~/.ssh/id_dsa
    Your public key has been saved in ~/.ssh/id_dsa.pub
    The key fingerprint is:
    Some really long string
    %
  • Step 2:
    Then, paste the content of the local ~/.ssh/id_dsa.pub file into the file ~/.ssh/authorized_keys on the remote host.
  • RSA instead of DSA
    • If you want something strong, you could try
      % ssh-keygen -t rsa -b 4096
    • Instead of the names id_dsa and id_dsa.pub, it will be id_rsa and id_rsa.pub , etc.
    • The rest of the steps are identical.

That’s it!

FAQ:

  • Q: I follow the exact steps, but ssh still ask me for my password!
  • A: Check your remote .ssh directory. It should have only your own read/write/access permission (octal 700)
    % chmod 700 ~/.ssh

Source: http://www.ece.uci.edu/~chou/ssh-key.html