How to authenticate a windows service with Azure AD to upload events to Office 365 Calendar?

Question

We use a third party website to manage our client appointments. I have written a web client to login and retrieve those appointments. Now I need to upload those to our Office 365 Calendar so these appointments are available there for mobile access. I need to implement this solution as a windows service that can run in AWS, separate from a web site.

I have found lots of examples on how to authenticate an app or a web application, but nothing on how to authenticate a windows service (without impersonation).

How do I register my windows service with Azure AD to grant my service access to the Office 365 API?

How do I use the Azure AD OAuth process to access the Office 365 API to read / write Calendar appointments?

Thanks in advance.

Answer 1

It depends on how you want it to work. If you want individual users to grant access to their mailboxes individually, you can use the same kind of flow, but you need some UI to allow the users to sign in and consent. If you don't want that, you need to have an organizational admin login and grant consent once for their entire org. This blog should get you started.