Is Azure AD Multi tenant application for SharePoint possible?

Question

I'm trying to convert Provider Hosted SharePoint Online application to Azure AD multi-tenant app, but I'm having issues registering existing application on SharePoint.

I created new app on Azure AD where I get application ID and Secret. I try to use that ID and Secret in my SharePoint deployment process but I am unable to register SharePoint application with that ID.

Issue is similar with one shown in question: Can you create a multitenant provider hosted app without using the office store? , however they reuse existing SharePoint ID & Secret but I cannot do that as Azure ID can only create new ID&Secret (meaning i cannot reuse existing one).

I need Azure AD app for OAuth flow because SharePoint app is used as office/outlook add-in, and only way to get user to log (and retrieve its info) in by using graph api.

Basically I'm grasping for straws here, any help is greatly appreciated.

Answer 1

You have to either choose to use the appid/secret generated in SharePoint (appregnew.aspx) OR have the app being created in Azure AD. You can't combine this into the same app. SharePoint apps are still using the old Azure ACS (Access Control Services).

If you're using the Graph API, just use an Azure AD app, you can pass that auth token to the SharePoint endpoint as well, if you have the correct permissions set.