5. Procedure – Enabling virus filtering in HTTP

Purpose: 

To configure virus filtering in the HTTP traffic with common parameter values, create an HttpProxy class which stacks CF to inspect the downloaded data. Complete the following steps.

These settings instruct the new HttpProxy to pass all responses (downloaded data) to the specified stacking provider — that is, to CF to scan everything downloaded via HTTP for viruses. Application-level Gateway will stack the stacking provider for every response (response_stack) that will scan the data part of the message for viruses.

Steps: 

1. Navigate to the Application-level Gateway MC component of the firewall host.

2. Select the Proxies tab, then click New.

   

   Figure 7. Creating a new proxy

3. Select the HttpProxy template from the left panel, and enter a name for the new class. Name this class HttpVirusProxy and click OK.

   

   Figure 8. Selecting a proxy template

4. Add the self.response_stack attribute to the Changed config attributes panel.

   

   Figure 9. Adding attributes to a proxy

5. Select this new attribute, then click Edit > New.

6. Enter the * (asterisk) character, then click OK.

7. Click on the text in the Type field, then select type_http_stk_data.

   

   Figure 10. Setting stacking type

8. Click Edit, then select the second row of the appearing panel (the one having vela_stack in its Type field). Click Edit.

   

   Figure 11. Selecting when to stack

9. Configure the proxy to send the incoming data to CF.

   

   Figure 12. Connecting the proxy to CF

   1. Select Stacking type > Stacking provider.

   2. In the Provider field, select the stacking provider policy (for example, CF) created in Procedure 4, Making CF available for Application-level Gateway services.

   3. In the Rulegroup field, select the rulegroup (for example, http) created in Procedure 4, Making CF available for Application-level Gateway services.

   4. Click OK.

   Python: Create an HttpProxy class which stacks CF to inspect the downloaded data.

   class HttpVirusProxy(HttpProxy):
       def config(self):
           HttpProxy.config(self)
           self.response_stack["*"]=(HTTP_STK_DATA, (V_STACK_PROVIDER, "CF", "http"))

10. Create a service that clients can use to access the Internet.

    1. Select Services > New, and enter a name for the service (for example, intra_HTTP_inter).

    2. Select Proxy class > HttpVirusProxy.

    3. Configure the other parameters of the service as needed for your environment, then click OK.

    4. Select Firewall Rules > New > Service, and select the service created in the previous step.

    5. Configure the other parameters of the rule as needed for your environment, then click OK.

    Python: Create an HttpProxy class which stacks CF to inspect the downloaded data.

    def demo_instance() :
        Service(name='demo_instance/intra_http_inter', router=TransparentRouter(), chainer=ConnectChainer(), proxy_class=HttpVirusProxy, max_instances=0, max_sessions=0, keepalive=V_KEEPALIVE_NONE)
    
        Rule(rule_id=1,
        src_zone=('*', ),
        dst_zone=('internet', ),
        proto=6,
        service='demo_instance/intra_http_inter'
        )

11. Commit and upload the changes, then restart Application-level Gateway.