ASP.Net Core 2.0 SignOutAsync删除错误的Cookie？

Question

i have a ASP.net Core 2.0 MVC Application and experiencing a weird problem. When using HttpContext.SignInAsync(...) to SignIn a User in my AccountsControler.cs this creates a Cookie named ".AspNetCore.Identity.Application". When later using HttpContext.SignOutAsync () to sign out the user, ASP.net Core decides to delete the cookie name "Identity.External" by setting this Cookie in the Response-Header to expire at the unix epoch.

Looks like i got something wrong with my CookieAuthentication. Anybody got an idea, where to look?

FunFact: Neither of both names is what i expected to see, since i configured a completely diffrent name for CookieAuthentication:

services.AddAuthentication (CookieAuthenticationDefaults.AuthenticationScheme)
.AddCookie (
    options => {
        options.Cookie.Name = "MyMagic.User";
    }
);

Answer 1

Actually the problem seemed to be, that i used

service.AddAuthentication(...)

in this App. Looks like a ASP.net Core 1.0 migration artefact in my code.

After removing the explicit Cookie-Authentication, SignInAsync() and SignOutAsync() used the same cookie name.

Additionally, with

services.ConfigureApplicationCookie(opts => {
   opts.Cookie.Name = "My.Cookie.User";
});

i was able to rename the cookie. :)