Why my OAuth provider works incorrectly when I add Identity to a project? - asp.net-core

Question

I have code that authenticates an user using OAuth. Here is this code: Github link
I use this code in the ConfigureServices() method of the Startup class:
public void ConfigureServices(IServiceCollection services)
{
services.AddAuthentication(CookieAuthenticationDefaults.AuthenticationScheme)
.AddCookie(options=>
{
options.LoginPath = new PathString("/Account/Login");
options.LogoutPath = new PathString("/Account/Logout");
options.AccessDeniedPath = new PathString("/Account/Forbidden");
})
.AddVkontakte(options => // here
{
options.ApiVersion = "5.95";
options.ClientId = Configuration["VKontakte:ClientId"];
options.ClientSecret = Configuration["VKontakte:ClientSecret"];
});
services.AddDefaultIdentity<User>(options =>
{
options.Password.RequireNonAlphanumeric = false;
options.Password.RequireUppercase = false;
})
.AddEntityFrameworkStores<ApplicationContext>()
.AddDefaultTokenProviders();
services.AddMvc();
}
But when I try to authenticate using it, nothing happens. It works the way I want, only when I remove this strokes
...
services.AddDefaultIdentity<User>(options =>
{
options.Password.RequireNonAlphanumeric = false;
options.Password.RequireUppercase = false;
})
.AddEntityFrameworkStores<ApplicationContext>()
.AddDefaultTokenProviders();
In both cases, the code behind .AddVkontakte(...) works correctly, I checked it in the network inspector of the browser. My code makes requests to the OAuth provider(vk.com) and successfully gets responses. But I don't understand why AddDefaultIdentity<User>(...) doesn't allow .AddVkontakte(...) to authenticate an user.
What do you think about this?

Answer 1

Okay, I looked at this question (Asp Core 2.1 Jwt + Identity. userManager store does not implement IUserRoleStore), and tried to change a little bit options passed to AddAuthentication, and it worked!
Here is the final code:
public void ConfigureServices(IServiceCollection services)
{
services.AddAuthentication(options=> // defined some options
{
options.DefaultAuthenticateScheme = IdentityConstants.ApplicationScheme;
options.DefaultChallengeScheme = IdentityConstants.ApplicationScheme;
options.DefaultSignInScheme = IdentityConstants.ApplicationScheme;
})
.AddCookie(options=>
{
options.LoginPath = new PathString("/Account/Login");
options.LogoutPath = new PathString("/Account/Logout");
options.AccessDeniedPath = new PathString("/Account/Forbidden");
})
.AddVkontakte(options =>
{
options.ApiVersion = "5.95";
options.ClientId = Configuration["VKontakte:ClientId"];
options.ClientSecret = Configuration["VKontakte:ClientSecret"];
});
services.AddDefaultIdentity<User>(options =>
{
options.Password.RequireNonAlphanumeric = false;
options.Password.RequireUppercase = false;
})
.AddEntityFrameworkStores<ApplicationContext>()
.AddDefaultTokenProviders();
services.AddMvc();
}
I don't know what does it mean, but it works! Wait and see.