To set xCALLY in the https secure connection go to the Settings -> General -> Secure Connection and select Yes.
After this change you have to reset the xcally-realtime service, using the command service xcally-realtime restart.
When you access to the xCALLY URL for the first time, you have also to accept the website certificate.
Open the linux console on your xcally server and edit the file: /etc/asterisk/res_xcalld.conf
and insert the xCally local ip address and set the webservice_secure parameter to yes
Reload the Asterisk configuration, type: asterisk –rx “reload”
After enabling the secure connection, you will need to request and install a VALID SSL certificate for the web server.
You can follow the standard CentOS apache https instructions to do it: