We are currently working on a new website and we have the requirement that visitors should be able to log in. Now we got an instance of IdentityServer4 running and we can sign users in with ASP.NET Identity using OWIN middleware. However, implementing this caused the good old Episerver CMS login to also use the one from OWIN. Understandable since we set the authentication mode in the Web.config to None.

But what we really like is to keep the CMS login page as is for the editors and admins and use the ASP.NET Identity for the visitors. How can we achieve this? We have tried to do something similar as described in the article about mixed mode OWIN authentication but to no avail.