About a year ago I've installed my first SSL certificate for this website. I got that certificate for free from the GitHub Student Developer Pack. So now a year later it's time to renew it. The renewal process is roughly the same as the registration process so in order to save myself some time next year I decided to write it up. This isn't a comprehensive guide, it focuses mainly on my specific setup. I'm running this site on a digital ocean Ubuntu droplet with Apache2. The SSL certificate is from Comodo RSA, offered through Namecheap.

  1. Buy or renew the certificate.
  2. Go to Domains/DomainList{:target="_blank"} and click activate.
  3. Connect to your server via SSH and use openssl req -new -newkey rsa:2048 -nodes -keyout server.key -out server.csr to generate a new CSR (Certificate Sigining Request). If you have multiple domains with SSL certificates it's recommended to replace "server" with your domain name.
  4. Make sure to fill in all the information requested by the CSR utility. If company name, organisation unit don't apply to you, use "NA". The most important information is the common name which should be your full domain name. E.g. "theowinter.ch" for me. For a subdomain it would be "sub.theowinter.ch". And for a wildcard domain "*.theowinter.ch".
  5. Open the generated server.csr with a text editor and copy the entire block including the header & footer.
  6. Paste the CSR into the Namecheap page and follow the instructions.
  7. At some point you will need to confirm that you own the domain. There's a choice between Email, HTTP-based and DNS-based. In my experience Email is easiest. In order to confirm the domain via email you need to have an email account like admin@domain.com. On a plain linux server you can simply use Postfix to redirect emails to your personal email address. I've written a post on how to do this.
  8. Once you have confirmed your domain you'll receive a mail with a zip file containing a yourDomain_com.crt and yourDomain_com.ca-bundle. Upload them to your server and place them in a folder where you can find them again. If you're renewing an existing certificate simply replace the old certificate files with the new ones and restart apache.
  9. If you're doing this for the first time you'll need to configure Apache2 to use the certificates you just uploaded. Navigate to /etc/apache2/sites-available and open the .conf file of your website in a text editor. Below you can see an example configuration that redirects all users to use HTTPS.
<VirtualHost *:80>
    #Redirect http://yourDomain.com to https://yourDomain.com
    ServerName yourDomain.com
    Redirect permanent / https://yourDomain.com/

<VirtualHost *:80>
    #Redirect http://www.yourDomain.com to https://yourDomain.com
    ServerName www.yourDomain.com
    Redirect permanent / https://yourDomain.com/

<VirtualHost *:443>
    ServerAdmin you@email.com
    DocumentRoot /var/www/yourDomain.com
    ServerName yourDomain.com
    ServerAlias www.yourDomain.com
    SSLEngine on
    SSLCertificateFile /home/root/yourDomain_com.crt
    SSLCertificateKeyFile /home/root/yourDomain.com.key

    #Rename yourDomain_com.ca-bundle to intermediate.crt
    SSLCACertificateFile /home/root/intermediate.crt

    ErrorLog ${APACHE_LOG_DIR}/error.log
    CustomLog ${APACHE_LOG_DIR}/access.log combined

Restart apache service apache2 restart and you're done. It's a good idea to
use SSL checker to confirm that everything is fine.