In .NET Core MVC you're encourages to use .NET Identity, but you don't have to. You can manage your own user identities and you use forms authentication which is now called Cookie Authentication (which is a better name really).

You need to install the Microsoft.AspNetCore.Authentication.Cookies nuget package.

There is some configuration that needs to go in startup.cs:

public void ConfigureServices(IServiceCollection services)

{

services

.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)

.AddCookie(options => {

options.AccessDeniedPath = "/ …