Utilizing OAuth2 for Office365, through Exchange ActiveSync (EAS)

Question

The blog post: Announcing Exchange ActiveSync v16.1 states that:

While not a part of EAS 16.1, we also want to note that both Office 365 and Outlook.com customers can now utilize the OAuth 2.0 protocol for authorization through EAS.

My question is: which scope should I use in the oauth request?

Is there an example, perhaps of the full request?

Note: there was a similar question about using OAuth for Office365 with IMAP, but here I'm specifically asking about ActiveSync. I referenced this question in a comment to one of the answers on that thread.

Secondary problem:

Thanks to Jason's answer and some additional tweaks, we managed to generate oauth token using https://login.windows.net/common/oauth2 but only for office365 users (Organization Accounts) and not to Microsoft users account (live, hotmail, outlook.com...)

The token allows access to both ActiveSync protocol (via https://eas.outlook.com/Microsoft-Server-ActiveSync) and for EWS API (via https://outlook.office365.com/EWS/Exchange.asmx).

Unfortunately we cannot find a way to generate same token for Microsoft online accounts (hotmail, live, outlook.com). We tried using this endpoint: https://login.live.com/oauth20_authorize.srf which allow only activesync and not EWS.

Is there a way to use the same token for both organization and online accounts on both protocols (ActiveSync and EWS)?

Answer 1

Sorry this took so long, but I wasn't aware of this question until today :). You need to register your app as a native application in Azure Active Directory:

Then add the Access mailboxes as the signed-in user via Exchange Web Services (under Office 365 Exchange Online) delegated permission.

NOTE: You cannot register this in the Application Registration Portal (https://apps.dev.microsoft.com), it needs to be registered in the Azure Portal (https://portal.azure.com/), and you need to use the v1 Azure auth endpoints for authorization and token requests.