How to create a Decryption Policy in SonicOSX 7.0?

04/08/2021 3 People found this article helpful 477,508 Views

Description

Decryption policies are used to create groups of rules defining which traffic should be decrypted. This decision is based on match criteria such as source IPs and destination IPs. Each decryption policy can have its own match criteria, along with an associated action. Once the match is done, we can decide whether we need to decrypt or bypass.

In SonicOSX 7.0, the HTTPS content filtering is no longer present. So, if we want to allow HTTPS websites, we need Client DPI SSL and a corresponding decryption policy to inspect them.

Resolution

Decryption policy rules define what type of traffic needs to be decrypted. There are three types of rules that can be added, each with its own parameters that can be used for the match.

DPI-SSL Client Rules
DPI-SSL Server Rules
DPI-SSH Rules

The match criteria for these rules can contain the following traffic parameters:

Client-side SSL Rules:

Source IP address
Destination IP address
Destination service (port/IP type)
User
Websites
Web category
Geo location
Schedule

Server-side SSL Rules:

Source IP address
Destination IP address
Destination service (port/IP type)
User
Geo location
Schedule

SSH Rules:

Source IP address
Destination IP address
Destination service (port/IP type)
User
Geo location
Schedule

Before we can create a decryption policy, these features should be enabled globally.

To Enable Client DPI-SSL:

Navigate to the Policy | Rules and Policies | Settings and Decryption (DPI-SSL) tab.
Under the General tab, use the toggle button to enable SSL Client Inspection, then click Accept at the bottom.
The DPI-SSL certificate should be installed on all end user machines for which this decryption policy is being created. You can either install the certificates manually or use a group policy to push the certificates to all machines that are part of the domain. You can download the DPI-SSL certificate by navigating to Policy | Rules and Policies | Settings | Decryption (DPI-SSL) and selecting the Certificate tab.

To enable Server DPI-SSL:

Navigate to the Policy | Rules and Policies | Settings and Decryption (DPI-SSL) tab.
Under the General tab, use the toggle button to turn on Enable SSL Server Inspection and then click Accept at the bottom.
The certificate and the server address object can be added by navigating to the Policy | Rules and Policies | Settings | Decryption (DPI-SSL) tab, then selecting the SSL Servers tab. Click Add.
The following options should be selected:

In the Address Object/Group pulldown menu, select the address object or group for the server or servers you want to apply DPI-SSL inspection to.
In the SSL Certificate pulldown menu, select the certificate that will be used to sign the traffic for the server.
The cleartext option indicates that the portion of the TCP connection between the UTM appliance and the local server will be in the clear without the SSL layer, thus allowing SSL processing to be offloaded from the server by the appliance. If you'd like to enable this, you will need to create a PAT rule to remap the encrypted service such as HTTPS to unencrypted service HTTP. Once selected, click Add.

To enable DPI-SSH

Navigate to Policy | Rules and Policies | Settings and Decryption (DPI-SSH) tab.
Use the toggle button to turn on Enable SSH Inspection, then click Accept at the bottom.

To create a Client SSL Decryption Policy

Navigate to the Policy | Rules and Policies | Decryption Policy tab. Make sure that the drop-down option at the top of the screen is set to Client SSL.
Click Top at the bottom of the screen. If you have multiple policies it is very important to properly prioritize them in order to make sure that the decryption policy is getting applied to the correct traffic.
Select the appropriate source/destination/service, or leave it set to Any to decrypt all traffic.
Under the URL tab, you can select the Web Category and Website lists as well. In the Action section choose whether you'd like to Decrypt or Bypass.
Click Save.

To Create a Server SSL/SSH Decryption Policy

Navigate to the Policy | Rules and Policies | Decryption Policy tab. Make sure that the drop-down option at the top of the screen is set to Server SSL or SSH.
From here, you'll follow the same steps outlined above to create rules .