Integrating Azure AD and AWS – Part 4

Integrating Azure AD and AWS – Part 4

We’ve reached the end of the road for my series on integrating Azure Active Directory (Azure AD) and Amazon Web Services (AWS) for single sign-on and role management. In part 1 I walked through the many reasons the integration is worth looking at if your organization is consuming both clouds. In part 2 I described the lab I used to for this series, described the different way application identities (service accounts for those of you in the Microsoft space) are handled in Active Directory Domain Services versus Azure AD, and walked through what a typical application identity looks like in Azure AD. In part 3 I walked through a portion of the configuration steps, did a deep dive into the Azure AD and AWS federation metadata, examined a SAML assertion, and configured the AWS end of the federated trust through the AWS Management Console. This included creation of an identity provider representing the Azure AD tenant and creation of a new IAM role for users within the Azure AD tenant to assert.

In this final post I’ll cover the remainder of the configuration, describe the “provisioning” capabilities of Azure AD in this integration, and pointing out some of the issues with the recommended steps in the Microsoft tutorial.

Before I continue with the configuration, let me cover what I’ve done so far.

  • Part 2
    • Added the AWS application from the Azure AD Application Gallery through the Azure Portal.
  • Part 3
    • Assigned an Azure Active Directory user to the application through the Azure Portal.
    • Configured the Azure AD to pass the Role and RoleSessionName claims through the Azure Portal.
    • Created the SAML identity provider representing Azure AD in the AWS Management Console.
    • Created an AWS IAM Role and associated it with the identity provider representing Azure AD in the AWS Management Console.

At this point JoG users can assert their identity to their heart’s content but we don’t have a list of what AWS IAM roles stored in Azure AD for our users to assert.  So how do we assert a role from Azure AD if the listing of the roles exists in AWS?  The wonderful concept of application programmatic interfaces (APIs) swoops in and saves the day.  Don’t get me wrong, if you hate yourself you can certainly provision them manually by modifying the application manifest file every time a new role is created or deleted.  However, there is an easier route of having Azure AD pick up those roles directly from AWS on an automated schedule.  How does this work?  Well nothing works better than demonstrating how the roles can be queried from the AWS API.

The AWS SDK for .NET makes querying the API incredibly easy.  We’re not stuck worrying about assembling the request and signing it.  As you can see below the script is six lines of code in PowerShell.

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The result is a listing of the roles configured in AWS which includes the AzureADEC2Admins role I created earlier.  This example demonstrates the power a robust API brings to the table when integrating cloud services.

2

When Microsoft speaks of provisioning in regards to the AWS integration, they are talking about provisioning the roles defined in AWS to the the application manifest file in Azure AD.  This provides us with the ability to assign the roles from within the Azure Portal as we’ll see later.  This differs from many of the Azure AD integrations I’ve observed in the past where it will provision a record for the user into the software as a service (SaaS) offering.  Below is a simple diagram of the provisioning process.3

To do support provisioning we need to navigate to the AWS Management Console, open the Services Menu, and select IAM.  We then select Users and hit the Add User button.  I named the user AzureAD, gave it programmatic access type, and attached the IAMReadOnlyAccess policy.  AWS then presented me with the access key ID and secret access key I’ll need to provide to Azure AD.  Yes, we are going to follow security best practices and provide the account with the minimum rights and permissions it needs to provide the functionality.  The Microsoft tutorial instructs you to generate the credentials under the context of the AWS administrator effectively giving the application full rights to the AWS account.  No Microsoft, just no.

I next bounce back to the Azure portal and to the AWS application configuration.  From here I select the Provisioning option, switch the drop-down box to Automatic, and plug the access key ID into the clientsecret field and the secret access key into the secret token field.  A quick test connection shows success and I then save the configuration.  Note that you must first save the configuration before you can turn on the synchronization.

4

After the screen refreshes I move down to the Settings section and turn the Provisioning Status to On and set the Scope to Sync only assigned users and groups (kind of a moot point for this, but oh well).  I then Save the configuration once again and give it about 10 minutes to pull down the roles.

I then navigate back to the Users and Groups section and edit the Rick Sanchez assignment.  Hitting the role option now shows me the AzureADEC2Admins role I configured in AWS IAM.


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Let’s take another look at the service principle representing the AWS application in PowerShell.  Using the Azure AD PowerShell cmdlets I referenced in entry 2 we connect to Azure AD and run the cmdlet Get-AzureADServicePrincipal which when run shows the manifest has been updated to include the newly synchronized application role.

6

We’ve configured the SAML trust on both ends, defined the necessary attributes, setup synchronization, and assigned Rick Sanchez an IAM role. In a moment we’ll demonstrate all of the pieces coming together.

Before I wrap it up, I want to quickly mention a few issues I ran into with this integration that seemed to resolve themselves without any intervention.

  1. Up to a few nights ago I was unable to get the Provisioning piece working.  I’m not putting it past user error (this is me we’re talking about) but I tried numerous times and failed but was successful a few nights ago.  I also noticed from some recent comments in the Microsoft tutorial people complaining of similar errors.  Maybe something broke for a bit?
  2. The value of the audience attribute in the audienceRestriction section of the SAML assertion generated by Azure AD doesn’t match the identifier within the AWS federation metadata.  Azure AD inserts some garbage looking audience value by default which was causing the assertions to be rejected by AWS.  After setting the identifier to the value of urn:amazon:webservices as referenced in the AWS federation metadata the assertion was consumed without issue.  I saw similar complaints in the Microsoft tutorial so I’m fairly confident this wasn’t just my issue.The story gets a bit stranger.  I wanted to demonstrate the behavior for this series by removing the identifier I had previously added.  Oddly enough the assertion was consumed without issue by AWS.  I verified using Fiddler that the audience value was populated with that garbage entry.  Either way, I would err on the side of caution and would recommend populating the identifier with the entry referenced in the AWS metadata as seen below.7.png

The last thing I want to point out is the Microsoft tutorial states that you are required to create the users in AWS prior to asserting their identity.  This is inaccurate as AWS does not require a user record to be pre-created in AWS.  This is different from a majority (if not all) of the SaaS integrations I’ve done in the past so this surprised me as well.  Either way, it’s not required which is a nice benefit if you’ve ever had to deal with the challenging of managing the identify lifecycle across cloud offerings.

Let’s wrap up this series by having Rick Sanchez log into the AWS Management Console and shutdown an EC2 instance.  Here I have logged into the Windows 10 machine named CLIENT running in Azure.  We navigate to https://myapps.microsoft.com and log into Azure AD as Rick Sanchez.  We then hit the Amazon Web Services icon and are seamless logged into the AWS Management Console.

8.png

Examining the assertion in Fiddler shows  the Role and RoleSessionName claims in the assertion.

9.png

Navigating to the EC2 Dashboard displays the instance I prepared earlier using my primary account.  Rick has full rights over administration of the instance for activities such as starting and starting the instance.  After successfully terminating the instance I log into the AWS Management Console as my primary AWS account and go to CloudTrail and see the log entries recording the activities of Rick Sanchez.

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With that let’s cover some key pieces of information to draw from the series.

  1. The Azure AD and AWS integration differs from most SaaS integrations I’ve done when it comes to user provisioning.  Most of the time a user record must exist prior to the user authenticating.  There are a growing number of SaaS providers provisioning upon successful authentication as provisioning challenges grow to further consumption of cloud services, but they are still few and far between.  AWS does a solid job with eliminating the pain of pre-provisioning users.
  2. The concept of associating roles with specific identity providers is really neat on Amazon’s part.  It allows the customer to manage permissions and associate those permissions with roles in AWS, but delegate the right on a per identity provider basis to assert a specific set of roles.
  3. Microsoft’s definition of provisioning in this integration is pulling a listing of roles from AWS and making them configurable in the Azure Portal.
  4. The AWS API is solid and quite easy to leverage when using the AWS SDKs. I would like to see AWS switch from what seems to be proprietary method of application access to OAuth to become more aligned with the rest of the industry.
  5. Don’t trust vendors to make everything point and click. Take the time to understand what’s going on in the background. In a SAML integration such as this, a quick review of the metadata can save you a lot of headaches when troubleshooting issues.

I learned a ton about AWS over these past few weeks and also got some good deep dive time into Azure AD which I haven’t had time for in a while.  Hopefully you found this series valuable and learned a thing or two yourself.

In my next series I plan on writing a simple application to consume the Cognito service offered by AWS.  For those of you more familiar with the Microsoft side of the fence, it’s similar to Azure AD B2C but with some unique features Microsoft hasn’t put in place yet making a great option to solve those B2C identity woes.

Thanks and have a wonderful holiday!

Integrating Azure AD and AWS – Part 1

Hi everyone.  After being slammed with work from the real job over the past few months, I’m back with a new deep dive into the integration between Azure Active Directory (AAD) and Amazon Web Services (AWS).  I enjoyed the heck out of this one because I finally got some playtime in AWS and got to integrate two of the big cloud providers together to make some cool stuff happen.  There are a lot of blogs and articles out there (including Microsoft’s and Amazon’s *cough cough*) which provide the steps to accomplish this integration, but either the steps are incomplete, outdated, or wrong and none of them give a great explanation of the why or the how.  I can’t complain though, what else would I blog about?

Before we jump into the technologies that power the integration, let me first answer the question as to why we’d want to do the integration in the first place.

Let’s face it, managing digital identities is hard and it’s only getting harder with the introduction of cloud technology to the mix.  The tens of thousands of identities you’re managing for your users on-premises data center can quickly grow into the millions when SaaS comes into the mix. The operational overhead or supporting those millions of identities can eat up a large part of your IT budget and make your user experience miserable.  Beyond the cost issue, saddling your users with hundreds of credentials means users are going to re-use passwords and store them in whatever ways are convenient for them (under the keyboard anyone?) which introduces the risk of the credentials being compromised and sensitive data getting leaked.

Now more than ever you need to put a strong focus on centralized identity management and modern authentication and authorization.  Historically this was very challenging to do because of the lack of application programming interfaces (APIs) that allowed for create read update delete (CRUD) operations against the individual user records represented in an application database such as a SQL backend.  Beyond the lack of good APIs, you also were stuck using complicated and limiting legacy authentication and authorization protocols such as Kerberos, NTLM, LDAP, and the like.

Thankfully the industry has made a dramatic shift towards providing robust web-based APIs and support for modern authentication and authorization such as SAML, WS-Fed, Open ID Connect, and OAuth.  This presents a unique opportunity for organizations to shift towards a centralized identity management model where one authoritative store drives the lifecycle of an identity across all applications.  With the introduction of the modern protocols, users aren’t required to maintain thousands of credentials and can instead rely upon a singular trusted credential service provider (CSP) to act as the primary authentication point allowing users to then assert their identities to applications.  This frees the application from having to be saddled with storing and managing user credentials as well as improving the user experience, not to mention using these modern protocols is far simpler for your average developer.

Integrating AAD and AWS allow you to take advantage of centralized identity and modern authentication and authorization.  AAD specifically allows you to leverage all the cool features of a modern Identity-as-a-Service (IDaaS) offering such as behavioral analytics, multifactor authentication, adaptive authentication, and contextual-based authorization.  The short of it is you get a rock solid IDaaS to back the industry leading PaaS and IaaS offerings of AWS.  The best of both worlds right?

Now that you understand why you’d want to integrate the two solutions, let’s look at the technology powering the solution. In this integration the vendors are leveraging the concepts of modern APIs and modern authentication and authorization I touched upon above.  First up is authentication.

aws-signon

In this integration SAML, specifically the identity provider-initiated single sign-on POST binding, is being used to assert the user’s identity to the service provider (SP) after the user successfully authenticates with the identity provider (IdP).  Azure AD plays the role of IdP and AWS plays the role of SP.  The sequence of events plays out as follows:

  1. The user navigates to AAD and authenticates using either a credential or an asserted identity from a federated identity store.  The user then selects AWS from the listing of applications exposed through a method like the MyApps portal.  AAD generates an assertion containing a claim of the user’s identity and the AWS Identity and Access Management (IAM) role(s) the user is authorized to use and redirects the user to an endpoint at AWS.
  2. The user’s browser posts the assertion to the endpoint at AWS.
  3. The assertion is passed to the AWS security token service (STS) which checks the assertion to ensure it is from an identity provider that has been configured to be trusted for the AWS account, verifies the roles can be granted to a federated user, and completes the authentication process granting the user access to the AWS management console.(Don’t worry, we’ll dig into this process much more deeply using Fiddler in the next post.)

For provisioning, the AWS API is used.  AAD queries the AWS API using credentials for an AWS security principal that is associated with a role that has the IAMReadOnlyAccess permissions policy or greater.  It queries for the IAM roles configured for the account and synchronizes those roles back to AAD.  When the synchronization is complete, AAD users can then be added to the relevant roles from within AAD creating a one stop shop for doing your identity lifecycle management, authentication, and authorization.  Nice right?

At a high level that is the why and the what. In my upcoming posts in this series I’ll be digging deep into the how.  This will include how to do the integration, the pitfalls of the Microsoft tutorial, and of course Fiddler captures showing the conversations between the web browser, AAD, and AWS.

The journey continues in my second entry.