title: Adding subdomains to existing certificate
body: <p>This seems like something that should be quite simple, but I don't know for sure so better safe than sorry.</p>
  
  <p>I have created a certificate for <code>mywebsite.com</code> and <code>www.mywebsite.com</code> using <a href="https://gethttpsforfree.com/" rel="noreferrer">https://gethttpsforfree.com/</a></p>
  
  <p>I now want to add <code>static.mywebsite.com</code>, <code>media.mywebsite.com</code>, <code>cache.mywebsite.com</code>, and these point to S3 buckets on AWS.</p>
  
  <p>I have a few questions about this process:</p>
  
  <ul>
  <li><p>Is it simply a matter of using the same account and domain private keys I generated last time, and creating a new Certificate Signing Request?</p></li>
  <li><p>If so, should the CSR have all domains/subdomains I want, or just the new ones?</p></li>
  <li><p>Since these point to S3 buckets, do I have to temporarily direct them to a webserver for the verification, or is there a way to verify on S3?</p></li>
  <li><p>Assuming no other problems, should I replace the existing public certificate on my Load Balancer with the new one and the existing domains will continue to work?</p></li>
  <li><p>When it comes time to renew, is it 90 days from today for all domains/subdomains, or is it 90 days for only the new subdomains signed today?</p></li>
  </ul>