Add additional Notification: AuthenticationComplete

[brentschmaltz]

This would be fired just before returning from AuthenticateAsync and would be symmetric to OnMessageReceived. It would take the AuthenticationTicket that was produced.

[Tratcher]

Something like this?
https://github.com/aspnet/Security/blob/dev/src/Microsoft.AspNet.Authentication.Twitter/TwitterAuthenticationHandler.cs#L172

[brentschmaltz]

@Tratcher It is not clear what you are suggesting.
Line 172 is: var model = await AuthenticateAsync();