Displaying the Blocking Message When Connecting to a Secure Site

Tuesday, August 6th, 2013

Using CyBlock Software or CyBlock Appliance, a secure Web site (https://domain) can be blocked by blocking the corresponding category, explicit URL, or custom category in which the URL has been added. If the secure site contains a path (https://domain/path), the URL match is made on only the domain portion by default. SSL Inspection has to be turned on with the associated blocked category set to be inspected in order to match on the domain and path portions combined.

However, the following issue may be encountered with the browser for a secure site (https://domain). When a user attempts to connect to a blocked secure site through CyBlock Software or CyBlock Appliance, the browser is only capable of receiving a Connection Established header response. Any other response, including a blocking message, is treated as a failed connection, and contents embedded in the response are not rendered due to security constraints.

Therefore, in order to display the blocking message when a user is connecting to a blocked secure site, the proxy must first send a Connection Established header which will require an SSL certificate to be accepted by the browser. This certificate is generated using the Wavecrest root certificate. If the Wavecrest root certificate is not already installed in the browser, a certificate warning message will be issued that must be accepted in order to display the blocking message. Please see the Wavecrest Certificate Installation Guide for instructions on how to install and distribute the Wavecrest root certificate and prevent the certificate warning message for your users.

If you do not accept the certificate when you receive the warning message, just a blank page will be rendered in the browser with a generic browser error message.

For additional assistance, please contact Technical Support at (321) 953-5351, Ext. 4 or support@wavecrest.net.