Exploring Azure AD Privileged Identity Management (PIM) – Part 2 – Setup

Posted on May 29, 2018 by mattfeltonma

Welcome back to part 2 of my series on Azure Active Directory Privileged Identity Management (AAD PIM). In the first post I covered the basics of the service. If you haven’t read it yet, take a few minutes to read through it because I’ll be jumping right into using the service going forward. In this post I’m going to cover the setup process for AAD PIM.

Before you can begin using AAD PIM, you’ll need to purchase a license that includes the capability. As we saw in my last post, at this time that means a standalone Azure AD Premium P2 or Enterprise Mobility + Security E5 license. Once the license is registered as being purchased by your tenant, you’ll be able to setup AAD PIM.

Your first step is to log into the Azure Portal. After you’ve logged in you’ll want to click the Create a Resource button and search for Azure AD Privileged Identity Management.

Select the search result and AAD PIM application will be displayed with the Create button. Click the create button to spin the service up for your tenant.

It will only take a few seconds and you’ll be informed the service has successfully been spun up and you’ll be given the option to add a link to your dashboard.

The global admin who added AAD PIM to the tenant will become the first member of the Privileged Role Administrator role. This is a new role that was introduced with the service. Members of this role are your administrators of AAD PIM and has full read and write access to it. Beware that other global admins, security administrators, and security readers only have read access to it. As soon as you successfully spin up the service, you’ll want to add another Privileged Role Administrator as a backup.

Upon opening AAD PIM for the first time, you’ll receive a consent page as seen below. The consent process requires confirmation of the user’s identity using Azure MFA. If the user isn’t enabled for it, it will be configured at this point.

After successfully authenticating with Azure MFA. The screen will update to show the status check was completed as seen below. This is a great example of Microsoft exercising the concept of step-up authentication. The user may have authenticated to the Azure Portal with a password or perhaps a still-valid session cookie. By prompting for an Azure MFA challenge the assurance of the user being the real user is that much higher thus reducing the risk of the user accessing such sensitive configuration options.

After clicking the Consent button the service becomes fully usable. The primary menu options are displayed as seen in the picture below. For the purpose of this post we’re going to click on the Azure AD directory roles option under the Manage section.

The Manage section of the menu is refreshed and a number of new options are displayed. Before I jump into the Wizard, I’ll navigate through each option in the section to explain its purpose.

The Roles option gives us a view of all of the users who are members of privileged roles within Azure AD and Office 365. In the activation column it’s shown as to whether or not the user is a permanent or eligible admin. The expiration column shows any user that is eligible and has actively requested and been approved for temporary access to the privileged role. As you can see from my screenshot from my test tenant I have a number of users in the global admin roles which is a big no no. We’ll remediate that in a bit using the Wizard.

Selecting the Add user button brings up a new screen where new users can be configured for privileged roles. Microsoft has done a good job of giving AAD PIM the capability of managing a multitude of Azure AD and Office 365 roles. Adding users to roles through this tool will make automatically make the user an eligible for the role rather than a permanent member like through other means would.

The Filter button allows for robust filtering options including the permission state (all, eligible, permanent), activation state (all, active, or inactive), and by role. The Refresh button’s function is obvious and the group option allows you to group the data either by user or by role. The Review button allows you to kick off an access review which we’ll cover in a later post. Lastly we have the Export button which exports the data to a CSV.

The Users option under the Manage section presents the same options as the Roles option except it takes a user-centric view.

The Alerts option under the Manage section displays the alerts referenced here. You can see it is alerting me to the fact I have too many permanent global admins configured for my tenant. I also have the option to run a manual scan rather than waiting on the next automatic scan.

The Access Reviews option under the Manage section is used to create new access review. I’ll cover the capability in a future post.

Skipping over the Wizard option for a moment, we have the Settings option. Here we can configure a variety of settings for roles, alerts, and access reviews.

Let’s dig into the settings for roles first.

Here we can configure the default settings for all roles as well as settings specific to one role. When a user successfully activates a privileged role, the membership in that role is time bound with a default of one hour. If after doing some baselining we find one hour is insufficient, we could bump it up to something higher. We can also configure notifications to notify administrators of activation of a role. There is also the option to require an incident or request reference that may map back to an internal incident management or request management system. Azure MFA can be required when a user activates a role. You’ll want to be aware that the MFA setting is automatically enforced for roles Microsoft views as critical such as global administrator.

Finally we have the option to require an approval. If you’ve played around with AAD PIM since preview, you may remember the approval workflow. For some reason the product team removed it when AAD PIM original went general available. This effectively meant users could elevate their access whenever they wanted. Sure they weren’t permanent members but there were no checks and balances. For organizations with a high security posture it made AAD PIM of little value and forced the on-demand management of privileged roles to be done using complicated PowerShell scripts or third-party tools that were integrated with the Graph API. It’s wonderful to see the product team responded to customer feedback and has added the feature back.

Toggling to Enable for the require approval option adds a section where you can select approvers for requests for the role.

Moving on to the Alerts settings we have the ability to configure parameters for some of the alerting as can be seen from the examples below.

The default values for the configurable thresholds around the “There are too many global administrator” should be a good wake up call to organizations as to the risk Microsoft associates with global admin access. The thresholds for the “Roles are being activated too frequently” should be left as the default until the behavior of your user base is better understood. This will help you to identify deviations from standard behavior indicating a possible threat as well as to identify opportunities to improve the user experience by bumping up the activation time span for users holding privileged roles that the hour long default activation time is insufficient.

Lastly we have Access Review settings. Here we can enable or disable mail notifications to reviewers are the beginning and end of an access review. Reminders can also be sent to reviewers if they have no completed a review they are a part of. A very welcome feature of requiring reviewers to provide reasons for approvals of a review. This can be helpful to capture business requirements as to why a user needs continued access to a role. Finally, the default access review duration can be adjusted.

Now on to the Wizard. The Wizard is a great tool to use when you first configure AAD PIM in order to get it up and running and begin capturing behavioral patterns. The steps within the Wizard are outlined below.

The Discover privileged roles step displays a simple summary of the privileged roles in use and the amount of permanent and eligible users. We can see from the below my tenant has exceeded either the 3 global admins or greater than 10% of users default thresholds for the “There are too many global admins” alert. Selecting any of the roles displays a listing of the users holding permanent or eligible membership in the role.

Clicking the next button bring us to the “Convert users to eligible step” where we can begin converting permanent members to eligible members. From a best practices perspective, you should ensure you keep at least two permanent members in the Privileged Role Administrator role to avoid being locked out if one account becomes unavailable. You can see that I’m making Ash Williams and Jason Voorhies eligible members of the global admins group.

After clicking the Next button I’m moved to the “Review the changes to your users in the privileged roles” step. I commit the changes by hitting the OK button and my two users are now setup as eligible members of the roles.

As you’ve seen throughout the post AAD PIM is incredibly easy to configure. I firmly believe that the only successful security solutions moving forward will be solutions that are simple to use and transparent to the users. These two traits will allow security professionals to focus less of their time on convoluted solutions and more time working directly with the business to drive real value to the organization.

I’m going to start something new with a quick bulleted list of key learning points that I came across while performing the lab and doing the research for the post.

AAD PIM can be configured after the first Azure AD Premium P2 or EMS E5 license is associated with the tenant
Be aware that at this time Microsoft does not enforce a technical control to prevent all users from benefiting from PIM but the licensing requirements require an individual license for each user benefitting from the feature. Make sure you’re compliant with the licensing requirements and don’t build processes around what technical controls exist today. They will change.
Once AAD PIM is activated by the first global admin, immediately assign a second user permanent membership in the Privileged Role Administrators role.

That’s it folks. In the next post in my series I’ll take a look at what the user experience is like for a requestor and approver. I’ll also look at some Fiddler captures to see I capture any detail as to how/if the modified privileges are reflected in the logical security token.

Thanks!

Exploring Azure AD Privileged Identity Management (PIM) – Part 1

Posted on May 25, 2018 by mattfeltonma

We’re going to take a break from Azure Information Protection and shift our focus to Azure Active Directory Privileged Identity Management (AAD PIM).

If you’ve ever had to manage an application, you’re familiar with the challenge of trying to keep a balance between security and usability when it comes to privileged access. In many cases you’re stuck with users that have permanent membership in privileged roles because the impact to usability of the application is far too great to manage that access on an “as needed basis” or as we refer to it in the industry “just in time” (JIT). If you do manage to remove that permanent membership requirement (often referred to as standing privileged access) you’re typically stuck with a complicated automation solution or a convoluted engineering solution that gives you security but at the cost of usability and increasing operational complexity.

Not long ago the privileged roles within Azure Active Directory (AAD), Office 365 (O365), and Azure Role-Based Access Control had this same problem. Either a user was a permanent member of the privileged role or you had to string together some type of request workflow that interacted with the Graph API or triggered a PowerShell script. In my first entry into Azure AD, I had a convoluted manual process which involved requests, approvals, and a centralized password management system. It worked, but it definitely impacted productivity.

Thankfully Microsoft (MS) has addressed this challenge with the introduction of Azure AD Privileged Identity Management (AAD PIM). In simple terms AAD PIM introduces the concept of an “eligible” administrator which allows you to achieve that oh so wonderful JIT. AAD PIM is capable of managing a wide variety of roles which is another area Microsoft has made major improvements on. Just a few years ago close to everything required being in the Global Admin role which was a security nightmare.

In addition to JIT, AAD PIM also provides a solid level of logging and analytics, a centralized view into what users are members of privileged roles, alerting around the usage of privileged roles, approval workflow capabilities (love this feature), and even provides an access review capability to help with access certification campaigns. You can interact with AAD PIM through the Azure Portal, Graph API, or PowerShell.

To get JIT you’ll need an Azure Active Directory Premium P2 or Enteprise Mobility and Security E5 license. Microsoft states that every use that benefits from the feature requires a license. While this is a licensing requirement, it’s not technically enforced as we see in my upcoming posts.

You’re probably saying, “Well this is all well and good Matt, but there is nothing here I couldn’t glean from Microsoft documentation.” No worries my friends, we’ll be using this series to walk to demonstrate the capabilities so you can see them in action. I’ll also be breaking out my favorite tool Fiddler to take a look behind the scenes of how Microsoft manages to elevate access for the user after a privileged role has been activated.

The Evolution of AD RMS to Azure Information Protection – Part 7 – Deep Dive into cross Azure AD tenant consumption

Posted on May 9, 2018 by mattfeltonma

Each time I think I’ve covered what I want to for Azure Information Protection (AIP), I think of another fun topic to explore. In this post I’m going to look at how AIP can be used to share information with users that exist outside your tenant. We’ll be looking at the scenario where an organization has a requirement to share protected content with another organization that has an Office 365 tenant.

Due to my requirements to test access from a second tenant, I’m going to supplement the lab I’ve been using. I’m adding to the mix my second Azure AD tenant at journeyofthegeek.com. Specific configuration items to note are as follows:

The tenant’s custom domain of journeyofthegeek.com is an Azure AD (AAD)-managed domain.
I’ve created two users for testing. The first is named Homer Simpson (homer.simpson@journeyofthegeek.com) and the second is Bart Simpson (bart.simpson@journeyofthegeek.com).
Each user have been licensed with Office 365 E3 and Enterprise Mobility + Security E5 licenses.
Three mail-enabled security groups have been created. The groups are named The Simpsons (thesimpsons@journeyofthegeek.com), JOG Accounting (jogaccounting@journeyofthegeek.com), and JOG IT (jogit@journeyofthegeek.com).
Homer Simpson is a member of The Simpsons and JOG Accounting while Bart Simpson is a member of The Simpsons and JOG IT.
Two additional AIP policies have been created in addition to the Global policy. One policy is named JOG IT and one is named JOG Accounting.
The Global AIP policy has an additional label created named PII that enforces protection. The label is configured to detect at least one occurrence of a US social security number. The document is protection policy allows only members of the The Simpsons group to the role of viewer.
The JOG Accounting and JOG IT AIP policies have both been configured with an additional label of either JOG Accounting or JOG IT. A sublabel for each label has also been created which enforces protection and restricts members of the relevant departmental group to the role of viewer.
I’ve repurposed the GIWCLIENT2 machine and have created two local users named Bart Simpson and Homer Simpson.

Once I had my tenant configuration up and running, I initialized Homer Simpson on GIWCLIENT2. I already had the AIP Client installed on the machine, so upon first opening Microsoft Word, the same bootstrapping process I described in my previous post occurred for the MSIPC client and the AIP client. Notice that the document has had the Confidential \ All Employees label applied to the document automatically as was configured in the Global AIP policy. Notice also the Custom Permissions option which is presented to the user because I’ve enabled the appropriate setting in the relevant AIP policies.

I’ll be restricting access to the document by allowing users in the geekintheweeds.com organization to hold the Viewer role. The geekintheweeds.com domain is associated with my other Azure AD tenant that I have been using for the lab for this series of posts. First thing I do is change the classification label from Confidential \ All Employees to General. That label is a default label provided by Microsoft which has an RMS Template applied that restricts viewers to users within the tenant.

One interesting finding I discovered through my testing is that the user can go through the process of protecting with custom permissions using a label that has a pre-configured template and the AIP client won’t throw any errors, but the custom permissions won’t be applied. This makes perfect sense from a security perspective, but it would be nice to inform the user with an error or warning. I can see this creating unnecessary help desk calls with how it’s configured now.

When I attempt to change my classification label to General, I receive a prompt requiring me to justify the drop in classification. This is yet another setting I’ve configured in my Global AIP policy. This seems to be a standard feature in most data classification solutions from what I’ve observed in another major vendor.

After successfully classifying the document with the General label protection is removed from the document. At this point I can apply my custom permissions as seen below.

I repeated the process for another protected doc named jog_protected_for_Ash_Williams.docx with permissions restricted to ash.williams@geekintheweeds.com. I packaged both files into an email and sent them to Ash Williams who is a user in the Geek In The Weeds tenant. Keep in mind the users in the Geek In The Weeds tenant are synchronized from a Windows Active Directory domain and use federated authentication.

After opening Outlook the message email from Homer Simpson arrives in Ash William’s inbox. At this point I copied the files to my desktop, closed Outlook, opened Microsoft Word and used the “Reset Settings” options of the AIP client, and signed out of my Office profile.

At this point I started Fiddler and opened one of the Microsoft Word document. Microsoft Word pops-up a login prompt where I type in my username of ash.williams@geekintheweeds.com and I’m authenticated to Office 365 through the standard federated authentication flow. The document then pops open.

Examining the Fiddler capture we see a lot of chatter. Let’s take a look at this in chunks, first addressing the initial calls to the AIP endpoint.

If you have previous experience with the MSIPC client in the AD RMS world you’ll recall that it makes its calls in the following order:

Searches HKLM registry hive
Searches HKCU registry hive
Web request to the RMS licensing pipeline for the RMS endpoint listed in the metadata attached to the protected document

In my previous deep dives into AD RMS we observed this behavior in action. In the AIP world, it looks like the MSIPC client performs similarly. The endpoint we see it first contacting is the Journey of the Geek which starts with 196d8e.

The client first sends an unauthenticated HTTP GET to the Server endpoint in the licensing pipeline. The response the server gives is a list of available SOAP functions which include GetLicensorCertificate and GetServerInfo as seen below.

The client follows up the actions below:

Now that the client knows the endpoint supports the GetServerInfo SOAP function, it sends an unauthenticated HTTP POST which includes the SOAP action of GetServerInfo. The AIP endpoint returns a response which includes the capabilities of the AIP service and the relevant endpoints for certification and the like.
It uses that information received from the previous request to send an unauthenticated HTTP POST which includes the SOAP action of ServiceDiscoveryForUser. The service returns a 401.

At this point the client needs to obtain a bearer access token to proceed. This process is actually pretty interesting and warrants a closer look.

Let’s step through the conversation:

We first see a connection opened to odc.officeapps.live.com and an unauthenticated HTTP GET to the /odc/emailhrd/getfederationprovider URI with query strings of geekintheweeds.com. This is a home realm discovery process trying to the provider for the user’s email domain.
My guess is this is MSAL In action and is allowing support for multiple IdPs like Azure AD, Microsoft Live, Google, and the like. I’ll be testing this theory in a later post where I test consumption by a Google user.

The server responds with a number of headers containing information about the token endpoints for Azure AD (since this is domain associated with an Azure AD tenant.)
A connection is then opened to odc.officeapps.live.com and an unauthenticated HTTP GET to the /odc/emailhrd/getidp with the email address for my user ash.williams@geekintheweeds.com. The response is interesting in that I would have thought it would return the user’s tenant ID. Instead it returns a JSON response of OrgId.

Since I’m a nosey geek, I decided to unlock the session for editing. First I put in the email address associated with a Microsoft Live. Instead of OrgId it returned MSA which indicates it detects it as being a Microsoft Live account. I then plugged in a @gmail.com account to see if I would get back Google but instead I received back neither. OrgId seems to indicate that it’s an account associated with an Azure AD tenant. Maybe it would perform alternative steps depending on whether it’s MSA or Azure AD in future steps? No clue.
Next, a connection is made to oauth2 endpoint for the journeyofthegeek.com tenant. The machine makes an unathenticated requests an access token for the https://api.aadrm.com/ in order to impersonate Ash Williams. Now if you know your OAuth, you know the user needs to authenticate and approve the access before the access token can be issued. The response from the oauth2 endpoint is a redirect over to the AD FS server so the user can authenticate.
After the user successfully authenticates, he is returned a security token and redirected back to login.microsoftonline.com where the assertion is posted and the user is successfully authenticated and is returned an authorization code.
The machine then takes that authorization code and posts it to the oauth2 endpoint for my journeyofthegeek.com tenant. It receives back an Open ID Connect id token for ash.williams, a bearer access token, and a refresh token for the Azure RMS API.

Decoding the bearer access token we come across some interesting information. We can see the audience for the token is the Azure RMS API, the issuer of the token is the tenant id associated with journeyofthegeek.com (interesting right?), and the identity provider for the user is the tenant id for geekintheweeds.com.
After the access token is obtained the machine closes out the session with login.microsoftonline.com and of course dumps a bunch of telemetry (can you see the trend here?).
A connection is again made to odc.officeapps.live.com and the /odc/emailhrd/getfederationprovider URI with an unauthenticated request which includes a query string of geekintheweeds.com. The same process as before takes place.

Exhausted yet? Well it’s about to get even more interesting if you’re an RMS nerd like myself.

Let’s talk through the sessions above.

A connection is opened to the geekintheweeds.com /wmcs/certification/server.asmx AIP endpoint with an unauthenticated HTTP POST and a SOAP action of GetServerInfo. The endpoint responds as we’ve observed previously with information about the AIP instance including features and endpoints for the various pipelines.
A connection is opened to the geekintheweeds.com /wmcs/oauth2/servicediscovery/servicediscovery.asmx AIP endpoint with an unauthenticated HTTP POST and a SOAP action of ServiceDiscoveryForUser. We know from the bootstrapping process I covered in my last post, that this action requires authentication, so we see the service return a 401.
A connection is opened to the geekintheweeds.com /wmcs/oauth2/certification/server.asmx AIP endpoint with an unauthenticated HTTP POST and SOAP action of GetLicensorCertificate. The SLC and its chain is returned to the machine in the response.
A connection is opened to the geekintheweeds.com /wmcs/oauth2/certification/certification.asmx AIP endpoint with an unauthenticated HTTP POST and SOAP action of Certify. Again, we remember from my last post that this requires authentication, so the service again responds with a 401.

What we learned from the above is the bearer access token the client obtained earlier isn’t attended for the geekintheweeds.com AIP endpoint because we never see it used. So how will the machine complete its bootstrap process? Well let’s see.

A connection is opened to the journeyofthegeek.com /wmcs/oauth2/servicediscovery/servicediscovery.asmx AIP endpoint with an unauthenticated HTTP POST and SOAP action of ServiceDiscoveryForUser. The service returns a 401 after which the client makes the same connection and HTTP POST again, but this time including its bearer access token it retrieved earlier. The service provides a response with the relevant pipelines for the journeyofthegeek.com AIP instance.
A connection is opened to the journeyofthegeek.com /wmcs/oauth2/certification/server.asmx AIP endpoint with an authenticated (bearer access token) HTTP POST and SOAP action of GetLicensorCertificate. The service returns the SLC and its chain.
A connection is opened to the journeyofthegeek.com /wmcs/oauth2/certification/certification.asmx AIP endpoint with an authenticated (bearer access token) HTTP POST and SOAP action of Certify. The service returns a RAC for the ash.williams@geekintheweeds.com along with relevant SLC and chain. Wait what? A RAC from the journeyofthegeek.com AIP instance for a user in geekintheweeds.com? Well folks this is supported through RMS’s support for federation. Since all Azure AD’s in a given offering (commercial, gov, etc) come pre-federated, this use case is supported.
A connection is opened to the journeyofthegeek.com /wmcs/licensing/server.asmx AIP endpoint with an uauthenticated HTTP POST and SOAP action of GetServerInfo. We’ve covered this enough to know what’s returned.
A connection is opened to the journeyofthegeek.com /wmcs/licensing/publish.asmx AIP endpoint with an authenticated (bearer access token) HTTP POST and SOAP action of GetClientLicensorandUserCertificates. The server returns the CLC and EUL to the user.

After this our protected document opens in Microsoft Word.

Pretty neat right? Smart move by Microsoft to take advantage and build upon of the federated capabilities built into AD RMS. This is another example showing just how far ahead of their game the product team for AD RMS was. Heck, there are SaaS vendors that still don’t support SAML, let alone on-premises products from 10 years ago.

In the next few posts (can you tell I find RMS fascinating yet?) of this series I’ll explore how Microsoft has integrated AIP into OneDrive, SharePoint Online, and Exchange Online.

Have a great week!

The Evolution of AD RMS to Azure Information Protection – Part 6 – Deep Dive into Client Bootstrapping

Posted on May 1, 2018 by mattfeltonma

Today I’m back with more Azure Information Protection (AIP) goodness. Over the past five posts I’ve covered the use cases, concepts and migration paths. Today I’m going to get really nerdy and take a look behind the curtains at how the MSIPC client shipped with Office 2016 interacts with AIP . I’ll be examining the MSIPC client log and reviewing procmon and Fiddler captures. If the thought of examining log files and SOAP calls excites you, this is a post for you. Make sure to take a read through my previous posts to ensure you understand my lab infrastructure and configuration as well as key AIP concepts.

Baselining the Client

Like any good engineer, I wanted to baseline my machine to ensure the MSIPC client was functioning correctly. Recall that my clients are migrating from an on-premises AD RMS implementation to AIP. I haven’t completed my removal of AD RMS so the service connection point for on-premises AD RMS is still there and the migration scripts Microsoft provides are still in use. Let’s take a look at the registry entries that are set via the Migrate-Client and Migrate-User script. In my last post I covered the purpose of the two scripts. For the purposes of this post, I’m going to keep it brief and only cover registry entries applicable to the MSIPC client shipped with Office 2016.

Migrate-Client
- Condition: Runs each computer startup only if it detects it has not run before or the version variable in the script has been changed.
- Registry Entries Modified:
  - Deletes HKLM\Software\Microsoft\MSIPC\ServiceLocation keys
  - Deletes HKLM\Software\Wow6432Node\Microsoft\MSIPC\ServiceLocation key
  - Deletes HKLM\Software\Microsoft\MSIPC\ServiceLocation\LicensingRedirection key
  - Deletes HKLM\Software\Wow6432Node\Microsoft\MSIPC\ServiceLocation\LicensingRedirection key
  - Add Default value to HKLM\Software\Microsoft\MSIPC\ServiceLocation\EnterpriseCertification key with data value pointing to AIP endpoint for tenant
  - Add Default value to HKLM\Software\Wow6432Node\Microsoft\MSIPC\ServiceLocation\EnterpriseCertification key with data value pointing to AIP endpoint for tenant
  - Add a value for the FQDN and single label URLs to on-premises AD RMS licensing pipeline to HKLM\Software\Microsoft\MSIPC\ServiceLocation\LicensingRedirection key with data values pointing to AIP endpoints for tenant
  - Add a value for the FQDN and single label URLs to on-premises AD RMS licensing pipeline to HKLM\Software\Wow6432NodeMicrosoft\MSIPC\ServiceLocation\LicensingRedirection key with data values pointing to AIP endpoints for tenant
Migrate-User
- Condition: Runs each user logon only if it detects it has not run before or the version variable in the script has been changed.
- Registry Entries Modified:
  - Deletes HKCU\Software\Microsoft\Office\16.0\Common\DRM key
  - Deletes HKCU\Software\Classes\Local Settings\Software\Microsoft\MSIPC key
  - Deletes HKCU\Software\Classes\Microsoft.IPViewerChildMenu\shell key
  - Add DefaultServerUrl value to HKCU\Software\Microsoft\Office\16.0\Common\DRM key and set its data value to the AIP endpoint for the tenant
- Files Modified:
  - Deletes the contents of the %localappdata%\Microsoft\MSIPC folder

A quick review of my client settings validates that all the necessary registry entries are in place and I have no issues consuming and created protected content.

Resetting the Client

If you have administered AD RMS in the past, you will be very familiar with how to re-bootstrap an RMS client. Microsoft has made that entire process easier by incorporating a “reset” function into the AIP client. The function can be accessed in Microsoft Office by hitting the drop down arrow for the AIP icon on the toolbar and selecting the Help and Feedback option.

After clicking the Help and Feedback option, a new window pops up where you can select the Reset Settings option to which performs a series of changes to the registry, deletions of RMS licenses, and AIP metadata. Lastly, I log out of the machine.

Bootstrapping the Client with Azure Information Protection

After logging back in I start up Fiddler, open Microsoft Word, and attempt to open a file that was protected with my AD RMS cluster. The file opens successfully.

One thing to note is if you’re using Windows 10 and Microsoft Edge like I was, you’ll need to take the extra steps outlined here to successfully capture due to the AppContainer Isolation feature added back in Windows 8. If you do not take those extra steps, you’ll get really odd behavior. Microsoft Edge will fail any calls to intranet endpoints (such as AD FS in my case) by saying it can’t contact the proxy. Trying with Internet Explorer will simply cause Fiddler to fail to make the calls and to throw a DNS error. Suffice to say, I spent about 20 minutes troubleshooting the issue before I remembered Fiddler’s dialog box that pops up every new install about AppContainer and Microsoft Edge.

The first thing we’re going to look at is the MSIPC log files which keep track of the client activity. I have to give an applause to whichever engineer over at Microsoft thought it would be helpful to include such a detailed log. If you’ve administered on-premises AD RMS in the past on previous versions of Microsoft Office, you’ll know the joys (pain?) of client side tracing with DebugView.

When we pop open the log we get some great detail as to the client behavior. We can see the client read a number of registry entries. The first thing we see is the client discover that is not initialized so it calls an API to bootstrap the user. Notice in the below that it has identified my user and it’s mentioning OAuth as a method for authentication to the endpoint.

Following this we have a few more registry queries to discover the version of the operating system. We then have our first HTTP session opened by the client. I’m pretty sure this session is the initial user authentication to Azure AD in order to obtain a bearer access token for the user to call further APIs

Bouncing over to Fiddler we can check out the authentication process. We can see the machine reach out to Azure AD (login.windows.net), perform home realm discovery which Azure AD determines that geekintheweeds.com is configured for federated authentication. The client makes the connection to the AD FS server where the user is seamlessly authenticated via Kerberos. The windowstransport endpoint is called which supports the WS-Trust 1.3 active profile. In an WS-Trust active flow, the client initiates the request (hence it’s active) vs the passive flow where the service provider initiates the flow. This is how Office applications support modern (aka federated) authentication.

After the assertion is obtained, it’s posted to the /common/oauth2/token endpoint at login.windows.net. The assertion is posted within a request for an access token, refresh token, and id token request using the saml1_1-bearer token grant type for the Azure RMS endpoint.

The machine is returned an access token, refresh token, and id token. We can see the token returned is a bearer token allowing client to impersonate my user moving forward.

Dumping the access token into the Fiddler TextWizard and decoding the Base64 gives us the details of the token. Within the token we can see an arm (authenticated method reference) of wia indicating the user authenticated using Windows authentication. A variety of information about the user is included in the token including UPN, first name, and last name.

I’m fairly certain the tokens are cached to a flat file based upon some of the data I did via procmon while the bootstrap process initiated. You can see the calls to create the file and write to it below.

After the tokens are obtained and cached we see from the log file that the MSIPC client then discovers it doesn’t have machine certificates. It goes through the process of creating the machine certificates.

We now see the MISPC client attempts to query for the SRV record Microsoft introduced with Office 2016 to help with migrations from AD RMS. The client then attempts discovery of service by querying the RMS-specific registry keys in the HKLM hive and comes across the information we hardcoded into the machine via the migration scripts. It uses this information to make a request to the non-authenticated endpoint of https://<tenant_specific>/_wmcs/certification/server.asmx.

Bouncing back to Fiddler and continuing the conversation we can see a few different connections are created. We see one to api.informationprotection.azure.com, another to mobile.pipe.aria.microsoft.com, and yet another to the AIP endpoint for my tenant.

I expected the conversation between api.informationprotection.azure.com and the AIP endpoint for my tenant. The connection to mobile.pipe.aria.microsoft.com interested me. I’m not sure if it was randomly captured or if it was part of the consumption of protected content. I found a few Reddit posts where people were theorizing it has something to do with how Microsoft consumes telemetry from Microsoft Office. As you could probably guess, this piqued my interest to know what exactly Microsoft was collecting.

We can see from the Fiddler captures that an application on the client machine is posting data to https://mobile.pipe.aria.microsoft.com/Collector/3.0/. Examination of the request header shows the user agent as AriaSDK Client and the sdk-version of ACT-Windows Desktop. This looks to be the method in which the telemetry agent for Office collects its information.

If we decode the data within Fiddler and dump both sets of data to Notepad we get some insight into what’s being pulled. Most of the data is pretty generic in that there is information about the version of Word I’m using, the operating system version, information that my machine is a virtual machine, and some activity IDs which must relate to something MS holds on their end. The only data point I found interesting was that my tenant ID is included in it. Given tenant id isn’t exactly a secret, it’s still interesting it’s being collected. It must be fascinating to see this telemetry at scale. Interesting stuff either way.

Continuing the conversation, let’s examine the chatter with my tenant’s AIP endpoint since the discovery was requested by the MSIPC client. We see a SOAP request of GetServerInfo posted to https://<tenant_specific>/_wmcs/certification/server.asmx. The response we receive from the endpoint has all the information our RMS client will need to process the request. My deep dive into AD RMS was before I got my feet with Fiddler so I’ve never examined the conversations with the SOAP endpoints within AD RMS. Future blog post maybe? Either way, I’ve highlighted the interesting informational points below. We can see that the service is identifying itself as RMS Online, has a set of features that cater to modern authentication, runs in Cryptomode 2, and supports a variety of authentication methods. I’m unfamiliar with the authentication types beyond X509 and OAuth 2. Maybe carry overs from on-prem? Something to explore in the future. The data boxed in red are all the key endpoints the RMS client needs to know to interact with the service moving forward. Take note the request at this endpoint doesn’t require any authentication. That comes in later requests.

After the response is received the MSIPC writes a whole bunch of registry entries to the HKCU hive for the user to cache all the AIP endpoint information it discovered. It then performs a service discovery against the authenticated endpoint using its bearer token it cached to the tokencache file.

Once the information is written to the registry, the client initiates a method called GetCertAndLicURLsWithNewSD. It uses the information it discovered previously to query the protected endpoint https://<tenant_specific>/_wmcs/oauth2/servicediscovery/servicediscovery.asmx. Initially it receives a 401 unauthorized back with instructions to authenticate uses a bearer token.

The client tries again this time providing the bearer token it obtained earlier and placed in the tokencache file. The SOAP action of ServiceDiscoveryForUser is performed and the client requests the specific endpoints for certification, licensing, and the new tracking portal feature of AIP.

The SOAP response contains the relevant service endpoints and user for which the query applied to.

The MSIPC client then makes a call to /_wmcs/oauth2/certification/server.asmx with a SOAP request of GetLicensorCertificate. I won’t break that one down response but it returns the SLC certificate chain in XrML format. For my tenant this included both the new SLC I generated when I migrated to AIP as well as the SLC from my on-premises AD RMS cluster that I uploaded.

The MISPC log now shows a method called GetNewRACandCLC being called which is used to obtain a RAC and CLC. This is done by making a call to the certification pipeline.

The call to /_wmcs/oauth2/certification/certification.asmx does exactly as you would expect and calls the SOAP request of Certify. This included my user’s RAC, and both SLCs and certificates in that chain. The one interesting piece in the response was a Quota tag as seen below. I received back five certificates, so maybe there is a maximum that can be returned? If you have more than 4 on-premises AD RMS clusters you’re consolidating to AIP, you might be in trouble. 🙂

The MISPC log captures the successful certification and logs information about the RAC.

Next up the client attempts to obtain a CLC by calling continuing with the GetNewRACandCLC method. It first calls the /_wmcs/licensing/server.asmx pipeline and makes a GetServerInfo SOAP request which returns the same information we saw in the last request to server.asmx. This request isn’t authenticated and the information returned is written to the HKCU hive for the user.

The service successfully returns the users CLC. The last step in the process is the MSIPC service requests the RMS templates associated with the user. You can see the template that is associated custom AIP classification label I created.

Last but not least, the certificates are written to the %LOCALAPPDATA%\Microsoft\MSIPC directory.

Conclusion

Very cool stuff right? I find it interesting in that the MSIPC client performs pretty much the same way it performs with on-premises exempting some of the additional capabilities introduced such as the search for the SRV DNS records and the ability to leverage modern authentication via the bearer token. The improved log is a welcome addition and again, stellar job to whatever engineer at Microsoft thought it would be helpful to include all the detail that is included in that log.

If you’ve used AD RMS or plan to use AIP and haven’t peeked behind the curtains I highly recommend it. Seeing how all the pieces fit together and how a relatively simple web service and a creative use of certificates can provide such a robust and powerful security capability will make your appreciate the service AD RMS tried to be and how far ahead of its time it was.

I know I didn’t cover the calls to the AIP-classification specific web calls, but I’ll explore that in my next entry. Hopefully you enjoyed nerding out on this post as much as I did. Have a great week and see you next post!

Journey Of The Geek

The chronicles of a Bostonian tech geek navigating through life, technology, and general geekiness.

Monthly Archives: May 2018

Exploring Azure AD Privileged Identity Management (PIM) – Part 2 – Setup

Exploring Azure AD Privileged Identity Management (PIM) – Part 1