ASP.NET Core Identity: Multiple providers for the same account

Question

I've been trying to wrap my head around the new ASP.NET Core Identity framework.

I want to be able to allow customers to sign-in using external providers so I do not have to worry about password storage. That works if I use the default provider: .AddDefaultIdentity<EntityUser>() , along with .AddAuthentication (with AddFacebook , AddGoogle , AddMicrosoftAccount ).

Some people have a Google account and a Facebook account. I would like to allow users to login to their account, and then add additional providers to the same user (so long as the e-mails match).

The Identity Framework portion of AspNetCore seems to tightly control everything. I know how to override the views, but not how to override control-flow. How can I dip my own logic into its processes to coerce login, registration? I would also like to forward a user to the external providers when the user is already logged in .

All I need is a direction, they've separated concerns so much with the new AspNetCore that it's akin to an onion. This makes it difficult to know where what you want is. I don't even know what I don't know to get started.

Answer 1

It already works the way you want, users can add any providers you've configured from the page at ~/Identity/Account/Manage/ExternalLogins

You can see the source code of the ExternalLogins razor page has logic which will show options for the user to add social auth to their existing account.