为什么 ASP.NET Core Identity Cookie 不能跨域工作？

Question

I set some cookie options in my ASP.NET Core Identity, to include a couple of subdomains:

        services.ConfigureApplicationCookie(identityOptionsCookies =>
        {
            identityOptionsCookies.Cookie.Domain = ".example.com";
            identityOptionsCookies.Cookie.Name = "ExampleToken";
        });

Based on this configuration, I login via this subdomain:

api.accounts.example.com

And I check that I am authenticated, using this API call:

api.accounts.example.com/identity/isAuthenticated => returns true

Now I go to another subdomain, using the same configuration for Startup.cs, and I'm not authenticated anymore:

api.user.example.com/teacher/list => redirects me to /Accounts/Login

Why is it so?

Answer 1

identityOptionsCookies.Cookie.Domain = "*.example.com";