We have an existing MVC app using the ASP.Net Identity Framework to store user logins/passwords/roles/etc... in a local SQL database. We would like to move the authentication portion of the identity to use a SAML IdP but still build out the IdentityUser object within the Identity Framework with the details from the local database. Essentially the flow would be:
User browses to site -> User is forwarded to IdP for authentication -> User is directed back to site after successful authentication -> Details from local SQL database are retrieved using information passed back from IdP (likely email address) -> Site leverages IdentityUser object with information from local database
I cannot find really any information on this approach, which makes me think it is not possible and/or advisable. Any direction or suggestions would be appreciated.