Retrieve Userid from a claims in a cookie in Core MVC

Question

I want to store a userId in a cookie, in ASP.NET Core MVC. Where can I access it?

Login:

var claims = new List<Claim> {
    new Claim(ClaimTypes.NameIdentifier, "testUserId")
};

var userIdentity = new ClaimsIdentity(claims, "webuser");
var userPrincipal = new ClaimsPrincipal(userIdentity);
HttpContext.Authentication.SignInAsync("Cookie", userPrincipal,
    new AuthenticationProperties
    {
        AllowRefresh = false
    });

Logout:

User.Identity.GetUserId(); // <-- 'GetUserId()' doesn't exists!?

ClaimsPrincipal user = User;
var userName = user.Identity.Name; // <-- Is null.

HttpContext.Authentication.SignOutAsync("Cookie");

It's possible in MVC 5 ------------------->

Login:

// Create User Cookie
var claims = new List<Claim>{
        new Claim(ClaimTypes.NameIdentifier, webUser.Sid)
    };

var ctx = Request.GetOwinContext();
var authenticationManager = ctx.Authentication;
authenticationManager.SignIn(
    new AuthenticationProperties
    {
        AllowRefresh = true // TODO 
    },
    new ClaimsIdentity(claims, DefaultAuthenticationTypes.ApplicationCookie)
);

Get UserId:

public ActionResult TestUserId()
{
    IPrincipal iPrincipalUser = User;
    var userId = User.Identity.GetUserId(); // <-- Working
}

Update - Added screenshot of the Claims which are null -------

userId is also null.

Solution 1

You should be able to get it via the HttpContext:

var userId = context.User.Claims.FirstOrDefault(x => x.Type == ClaimTypes.NameIdentifier)?.Value;

In the example context is the HttpContext.

The Startup.cs (just the basics as in the template website):

public void ConfigureServices(IServiceCollection services)
{
    services.AddIdentity<ApplicationUser, IdentityRole>()
        .AddEntityFrameworkStores<ApplicationDbContext>()
        .AddDefaultTokenProviders();
    services.AddMvc();
}

public void Configure(IApplicationBuilder app)
{
    app.UseIdentity();
    app.UseMvc();
}

Solution 2

Using FindFirst method from ClaimsPrincipal class:

var userId = context.User.FindFirst(ClaimTypes.NameIdentifier)?.Value;

Comments

[radbyx]

Will test later. But I'm pretty sure I tryed "User.Claims" which are "null". I don't know why though :)

[radbyx]

It's also null. I'm sure your line is correct, but I must need something else I guess. Like something in StartUp.cs I have not added yet. ASP.NET Core MVC is new to me, so I might not have added all nesessary dependencies, for Claims to work.

[radbyx]

See added Screenshot :)

[kloarubeek]

and logout is a controller action? Maybe the user is already logged out? Is the value available after you logged in?

[radbyx]

Yes it's another Action. I have to the logic in another Action, before I can poke into the cookie. At least that's the way it was in MVC 5 when I made it there, if I remembered correct.

[kloarubeek]

put a breakpoint in it, maybe the action is visited twice: the first time the user is still logged in, but the second time it's logged out and the cookie is cleared.

[radbyx]

It's not that. I have a breakpoint and just below in the logiutbaction i call SignOutAsync(). Could you add your StartUp.cs to your answer?

[Admin]

I have claims but don't know how to store in cookie