Previous to version 11.x.x of cPanel‘s WHM interface there was an option in the SSL/TLS section to either generate a self-signed SSL certificate for the server or to install a real SSL certificate.  However, in 11.x.x (not sure exactly when this changed) this option no longer exists.  Even if you install your SSL certificate through the normal process for installing SSL certificates for domains it won’t work as expected. 

If you have changed the Tweak Settings option “When visiting /cpanel or /whm or /webmail with SSL, you can choose to redirect to:” to Hostname or SSL Certificate and you navigate to a hosted domain at https://www.domain.com/cpanel it will redirect to https://servername.com:2083/, however, it will not be using the SSL certificate that you just installed.  “But why?”, you may ask.  The reason is because you installed the SSL certificate for Apache, but you did not install it for the WHM/cPanel interface.  The installation for the cPanel/WHM SSL certificate has been moved to a different section of WHM. This is because cpsrvd handles SSL requests for WHM/cPanel whereas Apache handles SSL requests for normal domain traffic.

Under the Service Configuration section of the standard WHM theme there is an option for “Manage Service SSL Certificates”.  Navigate to this page and you will see it lists certificates (self-signed) for Exim, Courier, FTP, and surprise… WHM/cPanel!  This is where you need to install your newly purchased SSL certificate. If you click on “Install New Certificate” you will be taken to the standard WHM SSL certificate installation form.  If you have already installed the certificate through the standard domain method then all you have to do is click on “Browse” next to Domain this CRT is for and select the servername from the list.  This will install your previously installed SSL certificate in the correct location. 

If you did not already install the SSL certificate you will have to do so by pasting the necessary information into the form and submitting it. If you haven’t already changed the Tweak Settings option to redirect make sure you don’t forget it. At this point you should be good to go!