title: SSH: "Bad passphrase" after generation of public key
body: <p>When I execute these commands (setting a passphrase, after the first)...</p>
  
  <pre><code>$ ssh-keygen -t dsa
  $ chmod 600 my_key
  $ chmod 600 my_key.pub
  </code></pre>
  
  <p>...and then, to test the passphrase...</p>
  
  <pre><code>$ ssh-add my_key.pub
  </code></pre>
  
  <p>...I keep getting:</p>
  
  <pre><code>Bad passphrase, try again for my_key.pub:
  Bad passphrase, try again for my_key.pub:
  Bad passphrase, try again for my_key.pub:
  Bad passphrase, try again for my_key.pub:
  ...
  </code></pre>
  
  <p>What am I doing wrong?</p>
  
  <p>This is on Ubuntu.</p>