title: ssl cacertfile generation
body: <p>What is the difference between ssl certfile and ssl cacertfile?</p>
  
  <p>I read that the first one is user's certificate, while the second is a trusted certificate used for verifying a peer certificate and can be omitted if I don't verify the peer.</p>
  
  <p>Given that i generate the first with </p>
  
  <pre><code>openssl x509 -req -days 30 -in request.pem -signkey key.pem -out certificate.pem
  </code></pre>
  
  <p>How can I generate the second?</p>