In a previous article published at www.isaserver.org I went through how to create a portal trunk in Forefront UAG to publish internal applications like Microsoft SharePoint. In this article I will show you how to extend the security for clients who want to access the Forefront UAG Server using Endpoint access policies. A Forefront UAG administrator can use a number of predefined endpoint access policies which checks clients that try to access the Forefront UAG Server. For instance, it can check if antivirus application is installed, if the Windows Firewall is enabled or the client is a corporate machine. If the predefined endpoint access policies are not sufficient it is possible to create your own endpoint access policies.
It is possible to create Forefront UAG endpoint access policies at the portal trunk level and at the application level in the portal.
Forefront UAG Endpoint access policies at portal level
To use endpoint access policies at the portal level navigate to the properties of the portal trunk and click the Endpoint Access Settings tab. There are a number of possible endpoint access settings:
- Session Access Policy
- Privileged Endpoint Policy
- Socket Forwarding Component Installation Policy
The Session Access Policy is used to control which clients are allowed to access the Forefront UAG portal before they can logon.
The Privileged Endpoint Policy is used for privileged clients who must provide a certificate in addition to the endpoint access policies. I will give you more information about privileged endpoints later on in this article.
The Socket Forwarding Component Installation Policy is used to control the requirements for clients which must use the UAG socket components for additional interaction with the Forefront UAG Server and the client.
If you don’t want to use endpoint access policies it is possible to configure Forefront UAG to use NAP (Network Access Protection).
Figure 1: Endpoint access settings at portal level
It is possible to edit the predefined endpoint access policies. Click Edit Endpoint Policies and you will see a list of predefined endpoint access policies. Forefront UAG endpoint policies can be platform specific. You can use policies for Windows clients, Mac OS and Linux.
Figure 2: Default endpoint access policies
The predefined endpoint policies come with a lot of possible settings as shown in the following screenshot and it is possible to combine different requirements with AND filters. You can also combine settings with OR and NOT filters.
Figure 3: Advanced Endpoint access policies
I will show you later in this article how to create your own endpoint policies.
Forefront UAG endpoint components
Before you can use endpoint policies with Forefront UAG the client who wants to access the portal must install some software components on the local machine. This software is called Forefront UAG endpoint components. There are two versions of this component: ActiveX and Java Applet.
This software is used for interaction between the client and the Forefront UAG Server and will be used to check if the client fulfils all requirements which administrators has defined in the endpoint policies on the Forefront UAG server. The following components are available:
The Forefront UAG endpoint components that are installed on client endpoints to enable Forefront UAG features and functionality include:
Forefront UAG Endpoint Component Manager
Downloads, installs, manages, and removes all the Forefront UAG endpoint components. There are two versions of this component: ActiveX and Java Applet.
Forefront UAG Endpoint Session Cleanup
There are two versions of this component: ActiveX and Java Applet. For more information, see About the Endpoint Session Cleanup component.
Forefront UAG Endpoint Detection
There are two versions of this component: ActiveX and Java Applet.
Several components are used to provide SSL tunneling capabilities.
The SSL tunneling components are:
Forefront UAG SSL Application Tunneling
There are two versions of this component: ActiveX and Java Applet
Forefront UAG Socket Forwarding
Forefront UAG SSL Network Tunneling
Socket Forwarding Helper
(More information can be found here)
Forefront UAG Endpoint component installation
The endpoint components will be installed when the user first opens the portal, but it is also possible to manually install the endpoint components via software distribution like Microsoft System Center Configuration Manager, Active Directory Group policies or third party software.
Figure 4: Endpoint acces components MSI files
It is also possible to configure the Forefront UAG Server portal to give clients the ability to install the endpoint components as an offline installer.
Component installation at client side
Due to the nature of modern web browsers there are some pitfalls when the endpoint components will be installed on the client. For example the Forefront UAG endpoint components requires that the portal website will be excluded from the pop-up blocker of Internet Explorer as shown in the following screenshot.
Figure 5: Installation warning message in Internet Explorer
After the endpoint components has been installed, the client will be checked for compliance against the Forefront UAG portal endpoint policies.
Figure 6: Portal access – Check for compliance
First time users will also get the following Security Alert. Users should always trust this site to avoid displaying the Security alert again.
Figure 7: IE popup message
It is possible to automatically add the UAG portal website to the trusted sites and to automatically disable the pop-up blocker for the UAG website with the help of some Registry modifications. I will give you more information later on in this article.
Forefront UAG Secure Endpoint Deployment
For more security, Forefront UAG administrators can deploy certified endpoints. Certified endpoints are more trusted for the Forefront UAG Server and you will have more control over clients which try to access the UAG portal. A certified endpoint is a client which has a certificate issued from an internal Certificate Authority.
To activate the Forefront UAG Server for certified endpoints you have to enable the checkbox in the Forefront UAG portal settings as shown in the following screenshot.
Figure 8: UAG certified endpoint
Before you can use Forefront UAG for certified endpoint access, a local certificate authority must be installed on the Forefront UAG Server. If an Active Directory integrated CA still exists you must install a subordinate CA on the Forefront UAG Server.
Certificate Authority installation
For the purposes of this article, I already deployed an Active Directory integrated Root CA so we will install a subordinate CA on the Forefront UAG Server.
Figure 9: Subordinate CA installation
Enable certified endpoint enrollment
After the CA has been installed on the Forefront UAG Server you must start the UAG Management console again and you are asked if you want to implement the certified endpoint enrollment on the Forefront UAG Server.
Figure 10: Enable certified endpoint
It takes some time until the certified endpoint enrollment is activated. You will get the following message: “Forefront UAG support for certified client endpoint enrollment has been enabled successfully”.
After the activation is completed, you can use the Forefront UAG management console to add the Certified Endpoint Enrollment application to the portal. If the client doesn’t have a certificate installed you must change the endpoint access settings in the portal trunk for the Certified Endpoint to Always, otherwise the client cannot connect to the portal to enrol for the Certified Endpoint.
Figure 11: Publish certified endpoint
If the client has already installed a certificate in the local certificate store, the user will get the following message and must select the appropriate certificate.
Figure 12: Client certificate question
After the user has been logged on successfully to the portal you can check if the client is now a certified and privileged device as shown in the following screenshot.
Figure 13: Certified endpoint
Forefront UAG endpoint component Registry patching
As I mentioned earlier, it is possible to automate the pop-up message for the pop-up blocker and the trusted site settings in Internet Explorer when the client tries to access the portal for the first time.
This Registry patch will only work if you have full control over the client so typically you can use this Registry patching only if the client is a corporate client.
Avoid popup in Internet Explorer
[HKEY_CURRENT_USER\Software\Microsoft\Internet Explorer\New Windows\Allow]
Forefront UAG Endpoint access policy customization
As I mentioned earlier on, it is possible to create your own endpoint access policies. For the example we will create a policy which checks if the client is a corporate PC joined to the Active Directory domain isaserver.org. Navigate to the UAG portal properties and click Edit Endpoint Policies and create a new policy. Click Manage Windows Policies.
Figure 14: Customize Endpoint access policies
We must use the Windows variables from the Advanced Policy Editor. Select Networks – Domains – DNS domain and enter the text as shown in the following screenshot to check if the clients NetBIOS and DNS domain name is ISASERVER OR ISASERVER.ORG.
Figure 15: Allow only domain joined clients to access the UAG portal
After the policy has been created, use the new policy in the platform specific policy for Windows. You can now use this new endpoint policy at Forefront UAG trunk level or for a specific application in the portal. In my opinion, it makes more sense to use this policy at application level. Every authenticated user can access the Forefront UAG portal after successful authentication and some basic endpoint policy settings have been checked but the important application with confidential content for example can only be accessed from corporate clients.
Figure 16: Apply policy
Forefront UAG Endpoint monitoring
Forefront UAG provides some monitoring capabilities regarding endpoint settings. A client is able to see detailed endpoint information in the portal as shown in the following screenshot.
Figure 17: client compliance information in the portal
The Forefront UAG Administrator can use the Forefront UAG Web Monitor which is part of the Forefront UAG installation to see details about the connection state of the client and the detected endpoint settings. Start the Forefront UAG Webmonitor, navigate to the Session Monitor – Active Sessions and hit the Session ID of the logged on user. The Endpoint Information tab provides the same information about Forefront UAG components and detected components like Windows Firewall, Windows version, Browser version and more.
Figure 18: Client information in the UAG Web Monitor
In this article I tried to give you an overview about Forefront UAG endpoint access policies. Forefront UAG Endpoint access policies are a really good solutions for the administrator to check clients for compliance before they are allowed to access a Forefront UAG portal.