Lets Talk About Azure AD Conditional Access and Automatic Device Registration

Let's talk about Azure AD Conditional Access for a second. 

Its deceiving, like rob you in the night after you thought you were friends deceiving. I say this for two reasons. 

1. In the rules for Conditional Access there is an option that is labeled 'domain joined'. This is misleading. What this is really checking against is if the device is registered within Azure AD and domain joined. If the device is domain joined but not registered then it won't honor the conditional access controls. Registration can happen automatically for domain joined devices once some configuration is done on prem (more on that later).

2. Conditional Access only supports applications that use modern auth. This wouldn't be so big a deal if when you enabled Conditional Access it disabled legacy authentication methods. It doesn't. What this means is all your fancy layered rules can be defeated by someone in China firing up Outlook 2010 and using a compromised account. Don't believe me? Take a look here. 

https://docs.microsoft.com/en-us/azure/active-directory/active-directory-conditional-access-supported-apps

Microsoft's suggested fix is to stand up ADFS and use claims rules to block legacy auth....not much of a fix in my opinion.

I want to circle back around to point number 1 and talk about how to do automatic registration of domain joined devices. 

Its not my style to just rehash all the steps in another article unless I had some sort of gotcha moment during it. The steps to enabling this feature can be found here 

https://docs.microsoft.com/en-us/azure/active-directory/active-directory-conditional-access-automatic-device-registration-setup

What I do want to touch on is some scenarios I had thought about when doing this. First some background info on how the registration works. Windows 10 devices have the logic to join Azure AD baked into the OS. You configure your SCP point and configure ADFS if you have it and you're off to the races. 

A little caveat that I found out is that my devices would not sync unless I was also syncing their Computer Account Object. I believe this is due to Windows 10 machines not being tied to a user account when they sync (more on that later). I did some testing and what I saw when I stopped syncing the Computer Objects was that it also removed my registered devices out of Azure AD. That is gotcha #1

Windows 7 devices are a little different. They require a small MSI package to be ran to force a registration since they do not have the baked in logic. What I found when testing these guys is that they are tied to a user, whatever user's login triggers the join gets the device put in their name. This means that only users that are being synced into Azure AD can register. Gotcha #2. If a non synced user tries it will fail silently. 

What is interesting though is that if a synced users stops syncing or gets removed from Azure AD the device will remain and not be associated to any user, like the Windows 10 devices.

So huge wall of text. Here's a picture of my devices and the output of dsregcmd /status on a successfully joined Windows 10 machine to make it all better.

See ya later!

Adding Additional OUs to AAD Connect Sync Filter

Hello again internet. Had a quick post I wanted to write up on changing or adding new OUs to your AAD Connect sync filter. 

First lets start off with a little background information. After you install AAD Connect by default it runs what is called a 'Delta' sync every 30 minutes. This sync only syncs changes made to objects since the last sync. 

The inverse of this is an 'Initial' sync and runs a full sync against all objects regardless if they have been changed or not. This feature is useful for 2 reason. 

1. Running an Initial sync is like giving AAD Connect the old turn it off and back on. Doing this can actually alleviate certain sync errors. I don't actually believe this is an intended use or feature of the Initial sync but what works in the field isn't always what works on paper.

2. Running an Initial sync will pick up any changes to your object filtering, such as adding or changing what OUs you are syncing. A regular Delta will not do this. 

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Now that we have that out of the way lets get into how to actually change what OUs you are syncing. The easiest and best way to do this is through the 'Synchronization Service' GUI. If you ever messed with AAD Connects predecessor, Dirsync, then this will look familiar. 

Once you are greeted with the console above you want to go to the Connector button across the top ribbon. When you arrive at this page you want to right click the connector with your local domain name and choose properties. 

Once inside of the properties you want to drop down to Configure Directory Partitions and then choose the Containers button.

You will then be greeted with a login prompt. Enter admin credentials with the proper permissions, which could vary depending on if you used express or custom setup. Once inside you will see a GUI with your AD layout. A simple check of the box, just like what you did during setup, can remove or add any OU. 

Once you have done this you will want to run an Initial sync. You can kick these off from the GUI but its messy. I reccomend using powershell. You can use the command

start-adsyncsynccycle -policytype Initial

Yes that is the word sync in there twice. You can also use this command to do a -policytype Delta switch for those times you want to manually kick off a sync. 

Once you run this Initial sync all the objects in your new OUs should start syncing!

If anyone stumbles upon this hope it helps you out some.