Integrating Azure AD and G-Suite – Single Sign-On

Integrating Azure AD and G-Suite – Single Sign-On

Hi everyone,

After working through the Azure Active Directory (AD) and Amazon Web Services (AWS) integration I thought it’d be fun to do the same thing with Google Apps.  Google provides a generic tutorial for single sign-on that is severely lacking in details.  Microsoft again provides a reasonable tutorial for integrating Azure AD and Google Apps for single sign-on.  Neither gives much detail about what goes on behind the scenes or provides the geeky details us technology folk love.  Where there is a lack of detail there is a blogging opportunity for Journey Of The Geek.

In my previous post I covered the benefits of introducing Azure AD as an Identity-as-a-Service (IDaaS) component to Software-as-a-Service (SaaS) integrations.  Read the post for full details but the short of it is the integration gives you value-added features such as multifactor authentication with Azure Multifactor Authentication (MFA), adaptive authentication with Azure AD Identity Protection, contextual authorization with Azure AD Conditional Access, and cloud access security broker (CASB) functionality through Cloud App Security.  Supplementing Google Apps with these additional capabilities improves visibility, security, and user experience.  Wins across the board, right?

I’m going to break the integration into a series of posts with the first focusing on single sign-on (SSO).  I’ll follow up with a post exploring the provisioning capabilities Azure AD introduces as well as playing around with Google’s API.  In a future post I’ll demonstrate what Cloud App Security can bring to the picture.

Let’s move ahead with the post, shall we?

The first thing I did was to add the Google Apps application to Azure AD through the Azure AD blade in the Azure Portal. Once the application was added successfully I navigated to the Single sign-on section of the configuration. Navigate to the SAML Signing Certification section and click the link to download the certificate. This is the certificate Azure AD will be using to sign the SAML assertions it generates for the SAML trust. Save this file because we’ll need it for the next step.

I next signed up for trial subscription of Google’s G Suite Business. This plan comes with a identity store, email, cloud storage, the Google productivity suite, and a variety of other tools and features. Sign up is straightforward so I won’t be covering it. After logging into the Google Admin Console as my newly minted administrator the main menu is displayed. From here I select the Security option.googlesso1

Once the Security page loads, I select the Set up single sign-on (SSO) menu to expand the option.  Google will be playing the role of the service provider, so I’ll be configuring the second section.  Check the box to choose to Setup SSO with third party identity provider.  Next up you’ll need to identify what your specific SAML2 endpoint is for your tenant.  The Microsoft article still references the endpoint used with the old login experience that was recently replaced.  You’ll instead want to use the endpoint https://login.microsoftonline.com/<tenantID>/saml2You’ll populate that endpoint for both the Sign-In and Sign-Out URLs.  I opted to choose the domain specific issuer option which sets the identifier Google identifies itself as in the SAML authentication request to include the domain name associated with the Google Apps account.  You would typically use this if you had multiple subscriptions of Google Apps using the same identity provider.  The final step is upload the certificate you downloaded from Azure AD.  At this point Google configured to redirect users accessing Google Apps (exempting the Admin Console) to Azure AD to authenticate.

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Now that Google is configured, we need to finish the configuration on Azure AD’s end.  If you follow the Microsoft tutorial at this point you’re going to run into some issues.  In the previous step I opted to use a domain specific issuer, so I’ll need to set the identifier to google.com/a/geekintheweeds.com.  For the user identifier I’ll leave the default as the user’s user principal name since it will match the user’s identifier in Google.  I also remove the additional attributes Azure AD sends by default since Google will discard them anyway.  Once the settings are configured hit the Save button.

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Now that both the IdP and SP have been created, it’s time to create a user in Google App to represent my user that will be coming from Azure AD.  I refer to this as a “stub user” as it is a record that represents my user who lives authoritatively in Azure Active Directory.    For that I switch back to the Google Admin console, click the User’s button, and click the button to create a new user.

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Earlier I created a new user in Azure AD named Michael Walsh that has a login ID of michael.walsh@geekintheweeds.com. Since I’ll be passing the user’s user principal name (UPN) from Azure AD, I’ll need to set the user’s Google login name to match the user’s UPN.

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I then hit the Create button and my new user is created.  You’ll need that Google assigns the user a temporary password.  Like many SaaS solutions Google maintains a credential associated with the user even when the user is configured to use SSO via SAML.  Our SP and IdP are configured and the stub user is created in Google, so we’re good to test it out.

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I open up Edge and navigate to the Google Apps login page, type in my username, and click the Next button.

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I’m then redirect to the Microsoft login page where I authenticate using my Azure AD credentials and hit the sign in button.

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After successfully authenticating to Azure AD, I’m redirected back to Google and logged in to my newly created account.

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So what happened in the background to make the magic happen?  Let’s take a look at a diagram and break down the Fiddler conversation.

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The diagram above outlines the simple steps used to achieve the user experience.  First the user navigates to the Google login page (remember SP-initiated SSO), enters his or her username, and is sent back an authentication request seen below extracted from Fiddler with instructs to deliver it back to the Azure AD endpoint for our tenant.

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The user then authenticates to Azure AD and receives back a SAML response with instructions to deliver it back to Google. The user’s browser posts the SAML assertion to the Google endpoint and the user is successfully authenticated to Google.

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Simple right?  In comparison to the AWS integration from an SSO-perspective, this was much more straightforward.  Unlike the AWS integration, it is required to have a stub user for the user in Google Apps prior to using SSO.  This means there is some provisioning work to perform… or does it?  Azure AD’s integration again offers some degree of “provisioning”.  In my next post I’ll explore those capabilities and perform some simple actions inside Google’s API.

See you next post!

11 thoughts on “Integrating Azure AD and G-Suite – Single Sign-On

    • Hi Han. Are you talking about setting up an email alias for the account in Google apps? I haven’t done that yet, but I can give it a try this weekend.

      Microsoft has some type of “provisioning” functionality which may provide some degree of synchronization. I haven’t tested it yet but plan to in my next post. Keep an eye out for it.

      Thanks for your feedback and I’ll let you know what I find out about the alias component.

      Like

  1. Pingback: Integrating Azure AD and G-Suite – Google API Integration Part 1 | Journey Of The Geek

  2. Thank you so much for putting this tutorial. I am still a new explorer around azure and was tearing my hair out with sso and google. Went through your article and suddenly had that moment where things just worked its like finding a ray of sunshine after staying in darkness for so long. Really appreciate your efforts and please carry on with the good work.

    Thank you

    Liked by 1 person

  3. Hi,

    I need to allow my users access to Azure AD services using G Suite ID’s. Will the same setup work for this or I need to configure things a bit differently.

    Thanks in advance

    Like

    • Hi Ravi,

      If I’m understanding right, your primary requirement is your users use a single identity to access both G-Suite and Azure AD. If that’s correct, you could leverage the SSO pattern, but you probably wouldn’t need the provisioning pattern unless you want to make Azure AD your authoritative source for identity data. You may want to think about that due to the extensive integration Azure AD has with third party apps. Microsoft if ahead of google right now in that space.

      I’m assuming you use a unique domain for your users in G-Suite and that you can prove ownership of that domain. If that’s the case you could register your domain in Azure AD and provision matching identities in the Azure AD tenant. From that point forward the pattern of access would mimic the SSO flow documented in my blog and Azure AD would be your authoritative source for user credentials (passwords).

      I believe Google can act as an IdP so you could theoretically do the reverse where Google is the IdP and Azure AD is the SP. You would lose out on some features of Azure AD such as it’s self
      Service password reset portal, identity protection, and some of the controls and intelligence it has around enforcing good password hygiene.

      Hope that helps!

      Like

  4. Can this be enhanced to use AD device certificates (or some other device attribute) to ensure that approved users can only access G Suite from approved devices?

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    • Hi Njoy. You could incorporate the use of Azure AD Conditional Access to create a rule that allows only managed devices access to G-Suite. By using Azure AD as your IdP, you can take advantages of the other IDaaS features to enforce additional controls around the the context of the user’s authentication, such as the user’s device.

      Like

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