CloudFlare has several SSL options available but you'll want to use the full (strict) mode. Per CloudFlare's support page, setting the SSL Option to strict will create a secure connection between the visitor and CloudFlare, and secure and authenticated connection between CloudFlare and your web server. Using either flexible or full can easily confuse the protocol detection mechanisms and cause mixed content warnings, which may lead to behavior that may adversely affect any HTTPS connections to the server.
If you are using CloudFlare for your site and want to utilize HTTPS (either on specific pages or site-wide), you should have an active SSL certificate installed on the server here. (How do I get an SSL certificate installed?)
Once we've confirmed your SSL certificate has been installed on the server, you'll also want to use a HTTPS CDN URL. Please let us know so we can set that up for you.
It is strongly recommended to have the SSL settings configured on the site/server and a HTTPS CDN URL defined prior to enabling SSL on your CloudFlare settings.
You'll need to update your site's URLs to default to HTTPS (ex. https://www.example-site.com). We can assist you with updating the URLs in the database!
We do not recommend using the HTTP protocol as the default in your site's URLs then terminating the SSL at CloudFlare (stopping the HTTPS connection before it gets to the server here).
Do you support CloudFlare Origin Certificates?
Yes, with some caveats. CloudFlare origin certificates can only work when you have CloudFlare in play for a domain. If CloudFlare's service is deactivated or you move away from their service, the certificate will cease to work.