Hello,
It is not clear what you mean when you say "block in https". There are several possibilities:
terminate HTTPS connections so that browser warns the user "cannot establish connection" - yes it is possible allow HTTPS connection and show the 'this site is blocked' message to the user - you would need the SSL man in the middle allow HTTPS connections, decrypt it and block within site contents if something inappropriate found - you would need the SSL man in the middle and ICAP server like http://docs.diladele.com/tutorials/filtering_https_traffic_squid_pfsense/index.htmlBest regards,
Sich