Multi-tenant ADAL JS SPA along with an Azure AD web application back-end

Question

I'm currently trying to implement a multi-tenant Azure AD application that will use Microsoft Graph API's to monitor and analyze Office 365 "metadata" for members of the tenant domain. For example, the application might monitor One Drive user space over time. The architecture of the application will include an AngularJS SPA client along with a web application back-end. The idea is that the web application allows for both local registration (eg traditional sign up using an email address and password) in addition to Azure AD authentication. In the case of local registration, the user might be able to associate an Azure AD tenancy with the local account in the future, for example.

I'm struggling to understand how various authentication mechanisms should work. For example, I think that there should be two levels of authentication in the case of Azure AD: one authentication for the users of the client SPA, and another authentication used by the back-end for making continuous calls to the Microsoft API's, requesting refresh tokens, etc.

• How might this architecture be implemented using the various Azure AD authentication scenarios Microsoft has already provided examples for?
• If my initial inclination that I will have two applications registered with Azure AD (for example, the SPA registered as a native application, say, and the web application registered by itself), how will users allow access to both of them, and what would this workflow look like? In addition, what would the flow of user requests look like? The SPA would make a request to the back-end using its Azure AD token, but what will the back-end do to receive its authentication token and make calls to the Microsoft API's?
• How might I best incorporate Azure AD authentication along with local registration into my application?

Answer 1

Generally speaking, you can associate your each user to his entity in Azure AD tenant in your backend server / database. As every user in Azure AD has several unique properties in the entity object. You can use the user's email or objectId as mentioned at Claims in Azure AD Security Tokens as the external column in your user table.

When your user authenticate your site via ADAL.JS , you can grab the access token in your backend server via the Authentication header. You can use the access token to request for the resources protected by Azure AD. And the access token is a JWT token, which you can decode directly to get the user basic claims as we mentioned before. You can retrieve the claim which you stored in your user table and match the special user registered in your server for requesting the resource protected by your self.