How to block pages within a website (eg. Facebook.com) using Regular Expressions (Regex)

How to block pages within a website (eg. Facebook.com) using Regular Expressions (Regex)

Let us say you have to block a user's page within Facebook. The page mustn't be available either by entering facebook.com/user.name nor from the search facility within Facebook and not only the main landing page of the user, but even Photos, About, Timeline etc. should not be available for viewing. To achieve this, we use the SonicWall Regular Expression (Regex) library in App Rules with Match Object type URL.

In this article, we use the following examples to block specific pages within websites:

To block all access to a user's page in Facebook, use
 

This regex will block access to the following pages
 

You could modify the regex according to your requirements.

Note:

If a website is accessed over HTTPS - in the case of facebook.com it is always over HTTPS by default - DPI-SSL Client Inspection needs to be enabled and the checkbox under Application Firewall must be checked.

Procedure:
 

9.   Click on Add after each entry.
10. Click on OK to save.



Create App Rules policy

1. Navigate to the Firewall | App Rules  page.
2. Enable the check-box Enable App Rules.
3. Click on the Add New Policy button to open the Edit App Control Policy window.
4. Set the App Rules policy with the following values:

• Policy Name: Block Facebook Users (or any name)
• Policy Type:  HTTP Client
• Source: Any
  
• Destination: Any
  
• Address: Any (These are IP addresses to be included)
• Service:  Source Any
• Service: Destination HTTP
• Exclusion Address: None
  
• Match Object:Included: Set the HTTP URL Match Object with regex content created earlier - Facebook Users
• Match Object:Excluded: None (This is for setting excluded URLs)
• Action Object: Reset/Drop
• Users/Groups: Included: All
• Users/Groups:  Excluded: None
• Schedule: Alway on
• Enable flow reporting: check or uncheck
• Enable Logging: Enabled by default
• Log individual object content: Enable check box (recommended)
• Log Redundancy Filter (seconds): Use Global Settings 
  
• Connection Side: Client Side
• Direction: Both

5. Click on OK to create this policy.



Testing:

From a host behind the SonicWall, try to access a user's page in facebook.com. When the request is blocked the webpage will fail to load and the following log messages will be generated in the SonicWall logs.