When I connect to SharePoint online using SharePointOnlineCredentials what type of authentication am I using? I don't think it is oauth.
Also the legacy authentication is being discontinued by MS. So will this way still work after that?
SharePoint Stack Exchange is a question and answer site for SharePoint enthusiasts. It only takes a minute to sign up.Sign up to join this community
For how this will work, you will register an Azure AD app with the appropriate Graph API permissions (there is also the v1 API which uses Client ID/Secret, registered in SharePoint itself).
See SharePoint authentication for how SharePoint Online auth is performed. Essentially, you're issued a FedAuth cookie.