I recently received a warning email from Google:
“Starting October 2017, Chrome (version 62) will show a ‘NOT SECURE’ warning when users enter text in a form on an HTTP page, and for all HTTP pages in Incognito mode.
The recommended solution was to migrate the affected website(s) to HTTPS. This requires an SSL certificate. There are many companies selling those for hundreds of dollars. I didn’t really want to spend that money.
It turns out there is a free alternative: The Let’s Encrypt project (https://letsencrypt.org/) provides free SSL certificates with just enough functionality to run SSL with current browsers. It also provides automated tools that greatly assist you in obtaining and installing those certificates.
I had a default SSL host configured on my Apache 2.4 installation (inherited from a different server running Ubuntu) that I had to manually remove.
Then, when all virtual hosts only had port 80 (HTTP) enabled, I could run the certbot tool as root:
# certbot --apache
It enumerates all host names supported by your Apache installation. I ran it repeatedly, for each domain and the corresponding www. host name (e.g. joewein.net, www.joewein.net) in my installation and verified the results, one at a time. It will create a new virtual host file in /etc/httpd/hosts-enabled for those hosts for port 443 (HTTPS). I appended the content of that file to my existing port 80 (HTTP) virtual host file in /etc/httpd/hosts-available for that host name and deleted the new file created by certbot. That way I can track all configuration details for each website for both HTTP and HTTPS in a single file, but this purely a personal choice.
All it takes is an Apache restart to enable the new configuration.
You can test if SSL is working as expected by accessing the website with a browser using https:// instead of http:// at the start of the URI.
If you have iptables rules for port 80, you may want to replicate those for port 443 or the certificate generation / renewal may fail. Also, you want to make sure that SSLv3 is turned off on your Apache installation, to protect against the POODLE vulnerability. This required the following setting in ssl.conf:
/etc/httpd/conf.d/ssl.conf:SSLProtocol all -SSLv2 -SSLv3
The free certificates will expire in 90 days, but it’s recommended to add a daily cron job that requests renewals so that an updated key will be downloaded after 60 days, long before the old key expires. Once that is in place, maintenance of SSL keys will be totally automatic.