How To Install AD FS 2016 For Office 365 – Part 2


This is the second in a series of three posts which will walk you through installing, configuring and connecting AD FS 2016 to Office 365.  In part one we installed the AD FS server on our corporate network, and tested that it was working.

In this second post we need to make the AD FS infrastructure available to the Internet in a secure fashion, so that Office 365 will be able to contact AD FS to authenticate user requests.  Previously this meant downloading and installing the AD FS 2.0 Proxy onto servers in the DMZ.  In AD FS 2012 R2 onwards, the AD FS proxy functionality is present in the Web Application Publishing (WAP) component of the Remote Access role.  There is no separate download required in modern versions of Windows.

In part three of this series, we will integrate the AD FS infrastructure with the Office 365 configuration.

The outcome achieved at the end of this post is the below solution.  Note that the AD FS servers are domain joined an located on the corporate network.  Windows 2012 R2 and newer contain the AD FS Proxy as part of the OS, specifically within the Remote Access role.  For the purposes of using AD FS for Office 365 we do not need to domain join the WAP servers.  They are able to provide AD FS proxy functionality as workgroup machines.

AD FS Topology

Planning And Prerequisites

Install And Configure AD FS Proxy OS

In this installation, the AD FS proxy server will be placed into the DMZ, and installed as a workgroup machine since the Wingtiptoys organisation does not possess a separate management forest in the DMZ.  Ensure the machine is built as per your standard build process, is secured and all Microsoft updates are installed.  Since AD FS and WAP are now a core part of the OS, they are serviced and maintained using Windows Updates.

Install  And Verify Certificate

As discussed in part one, you will need a certificate from a trusted third party.  Ensure that you check with the CA to ensure that you are able to install the certificate onto multiple servers as this is blocked in some license agreements.  This is something that you must check directly with the CA.

If you are allowed to install the certificate from the AD FS server, then this simplifies matters else you will require an additional certificate.  The name must match the AD FS namespace that you selected through the AD FS design process.  By using the exact same certificate this allows the following features to be enabled:

  • ExtendedProtectionTokenCheck to be enabled on AD FS.  It is enabled by default.
  • WAP can proxy AD FS requests that use Windows Integrated Authentication

Name Resolution

Since the AD FS proxy server[s] will be in  a network which may not have access to the internal DNS zone information, ensure that WAP is able to resolve the AD FS namespace to the internal AD FS infrastructure.  Typically this will point to the VIP of the internal AD FS load balanced endpoint.  A swift update to the local hosts file may suffice, just remember to add this to your build documentation.  In some cases you way need to set a DNS suffix in the system properties or in the IP configuration.

External DNS Record

Create external DNS record for the AD FS proxy server.  This A record will exist in the external DNS zone.  In the Wingtiptoys enterprise (cough, cough this lab) the internal DNS zone is held on AD integrated DNS zones.  The external zone is at a commercial ISP, so the external DNS record was created at the commercial ISP so it resolves to the external IP of the AD FS proxy infrastructure when I am at Starbucks.

As with the internal AD FS farm, there should be multiple WAP servers in the DMZ.  They should be load balanced, and the DNS record should resolve to the VIP.

Open Firewalls

Having the external DNS record point to the AD FS server’s external IP address will not allow traffic to flow unless the firewalls are configured to do so.  In enterprises the AD FS proxy server will be installed into a DMZ so there will be an internal and external firewall.  Both must be opened to allow inbound SSL traffic over TCP port 443.  In addition to this, the servers will also need access to the CA’s CRL distribution points on the Internet to verify certificate validity.

Exchange administrators should be used to this now as they have see Exchange updates take a long time to install on Exchange servers do not have access to crl.microsoft.com.  In the case of AD FS, the server should be able to hit the CRL of external CAs.  Each vendor has their own endpoints.

The AD FS server will require access to the Internet in order to complete the configuration of the solution (in the 3rd post of this series).  This may be an issue if your servers are behind a proxy solution.

Installing Web Application Proxy

First we will go through the graphical install process, then review the PowerShell commands to install the necessary role services and then to configure WAP.  There are two discrete tasks which are to be performed.  The Remote Access role with with the Web Application Proxy service must first be installed, and then it can be configured.

Let’s fire up the Add Roles Wizard from Server Manager!

Windows Server 2016 Add Roles and Features Wizard

As noted in the previous post, there is no longer a separate AD FS proxy role in Windows 2016.  The Remote Access feature provides VPN, Direct Access and Web Application Proxy (WAP) functionality.  It is the latter that we need to install.

Select Remote Access and let’s go find the droids we are looking for…

Windows Server 2016 Add Roles and Features Wizard - Select Remote Access Role

Unless you want to add any features, like telnet * for troubleshooting purposes later, click next.

Optional - If Additional Features Are to be Enabled

The Remote Access role selection process starts.  Unlike in days of old when installing a feature would install all of the bits, and by extension potential vulnerabilities, Windows now wants to only install the bare minimum.  This is a paradigm shift compared to the early days of IIS where it would install everything and then you have to spend time stripping stuff back out.  Index extension attack anyone?

Add Roles and Features Wizard - Remote Access

In our case we just want to install the Web Application Proxy role service, so select that and click next

Chose Which Role Service To Install

Web Application Proxy Role Installed - Additional Required Features Automatically Added

Confirm the choice, and then install.

Add Roles and Features Wizard - Confirm Selection

Once the necessary WAP role services are installed, we are then able to launch the Web Application Proxy Wizard to configure WAP.

Windows Server 2016 Web Application Proxy Installation In Progress

The installation process will complete, click to close the wizard.

Windows Server 2016 Web Application Proxy Installation Completed

Configure Web Application Proxy

We need to configure the WAP proxy with the necessary information so that it knows it will be publishing our internal AD FS server and how to access AD FS.  Under administrative tools, open the Remote Access Management console.

Select the Web Application Proxy role which is listed on the left hand pane, and then the option to run the Web Application proxy configuration wizard will be displayed.

Remote Access Management Console - Start WAP Configuration Wizard

The wizard will then initiate the process to configure the Web Application Publishing service.

Starting WAP Configuration Wizard

The screen below is where most configuration issues arise with this process.  What a lot of folks do is interpret the Federation service name as the display name of the AD FS server.  That will not get you very far unfortunately…

WAP Configuration Wizard - Select Federation Server

The federation service name field does NOT want you to enter the display name of the AD FS server farm.   The display name in the previous example was “Wingtiptoys STS”. and this can been checked by looking in the AD FS console on the AD FS server itself.

Checking AD FS Federation Service Name

If you look closely at the AD FS properties, the federation service name is actually the FQDN of the service.  In our case this is sts.wingtipyoys.ca so let’s enter that along with administrator credentials on the AD FS server so we are able to access AD FS.

WAP Configuration Wizard - Entered Correct Federation Server (Not The Display Name)

In the same way that we require a SSL certificate on the AD FS server, the same is true on the WAP as clients will establish SSL sessions to this machine.  WAP will then us a SSL session to the internal AD FS server on TCP 443.

Since the certificate was previously installed and verified as part of the preparatory work, we select it and move on.

WAP Configuration Wizard - Select AD FS Certificate

Verify the details, and click configure.

WAP Configuration Wizard - Confirm Selection

The wizard starts to configure the AD FS proxy

WAP Configuration Wizard - Starting Configuration

And shortly thereafter completes!

WAP Configuration Wizard - Configuration Complete

Installing Web Application Proxy Using PowerShell

In the vein as the graphical installation, there are two discrete tasks which are to be performed.  The Remote Access role with with the Web Application Proxy service must first be installed, and then it can be configured.

Install Remote Access – Web Application Proxy

The below command will install the necessary OS components for the Remote Access role.

Install-WindowsFeature Web-Application-Proxy –IncludeManagementTools

Configure Web Application Proxy Using PowerShell

Once the OS components have been installed, they must be configured.  Note that you require the correct certificate thumbprint, and the command will prompt for an account which has administrative permissions on the AD FS server.

Install-WebApplicationProxy  –CertificateThumbprint 'D2B9FFAC14FB8AE4E5BD1F06DD87CD41568E025A' -FederationServiceName 'sts.wingtiptoys.ca'

 

Verifying AD FS Proxy Installation

At this time we should have a functional AD FS proxy server that is able to provide internet based users with access to our AD FS server’s authentication services.  But as always, we need to test!

To open up the Remote Access management console, use the Remote Access Management shortcut in administrative tools.

If you have immediately launched this after installing the AD FS proxy it may take a few seconds or a refresh to show up.  The other top tip is not to look for a published web app.  Remember that WAP can be used to publish various applications to the internet, but in this case we are just wanting to use the base AD FS proxy components.  No further configuration is required.

To check that the AD FS proxy is running, click onto the Operational Status in the left hand tree

Selecting the operational status, will then show how the AD FS proxy is currently running.  You can also jump to Perfmon or Event Viewer from this node.

Checking WAP Operation Status

Should the AD FS proxy have an issue the console will light up like a Christmas tree.  In this case I deliberately stopped the “Active Directory Federation Services” service on the AD FS proxy, please click to enlarge the image:

Checking WAP Operation Status - Required Service Not Running

Even though the Windows service is name the same on both the AD FS server and the AD FS proxy, note that the executable path is different:

WAP

AD FS Proxy Service Executable

AD FS

AD FS Service Executable

Verify AD FS Proxy Configuration

In event viewer on the AD FS proxy, open up the application and services logs and check that the proxy is able to retrieve it’s configuration from the AD FS server.  This can be seen here, click to enlarge:

With the full EventID 245 details shown here:

EventID 245 - AD FS Proxy Able To Retrieve Configuration From AD FS

Verify Federation Service Metadata

Using the same URL as before, open Internet Explorer and navigate to your AD FS server’s federation metadata URL.

This will be something like the below, just change the FQDN to match your environment.

https://adfs.tailspintoys.ca/federationmetadata/2007-06/federationmetadata.xml

https://sts.wingtiptoys.ca/federationmetadata/2007-06/federationmetadata.xml

The intent here is to ensure that we are able to get to the site externally.  If you are not able to see the AD FS text rendered in the browser, start with ensuring that the firewalls are not dropping traffic.

Verify Federation Service Metadata

Verify AD FS Sign-In Page

Browse to the AD FS sign-in page and test that you are able to authenticate.

The URL will be similar to the below, again change the FQDN to match your organisation’s.

https://adfs.tailspintoys.ca/adfs/ls/idpinitiatedsignon.htm

https://sts.wingtiptoys.ca/adfs/ls/idpinitiatedsignon.htm

You should see the below, and be prompted to sign in:

(Note that I did not full screen the window before grabbing capture else it would be too small)

Verify AD FS IdpInitiatedSignon Page

Clicking the Sign In button will prompt for credentials:

Verify AD FS IdpInitiatedSignon Page - Enter Credentials

If you successfully authenticate then you will be rewarded with this stellar screen:

Verify AD FS IdpInitiatedSignon Page - Enter Credentials

And if are unable to type a password (like me doing demos) then you will get this less than stellar result:

Verify AD FS IdpInitiatedSignon Page - Invalid Password Entered

In part three we will complete the configuration, and instruct Office 365 to leverage the shiny AD FS infrastructure to authenticate users.

Cheers,

Rhoderick

* – Not having telnet client by default always grates.  In the same way that explorer file options are always set to hide the good stuff like file extensions, system files and the ilk.

Comments (4)

  1. Turbomcp says:

    Thanks

  2. Turbomcp says:

    forgot to add that there are 2 more services for wap that also need to be up and running(on verification steps) these sometimes don’t start automatically…

  3. Thanks for sharing. Referenced this post in my AD FS workshop class 🙂

    1. Hi Thomas,

      Thanks for taking the time to comment – much appreciated!

      Please do let me know what the feedback is from your students – if they find it useful and what else they need.

      Cheers,
      Rhoderick

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