How to logout all users in ASP.NET Core cookie authentication?

Question

I'm using ASP.NET Core MVC with CookieAuthentication. Is there a way I can sign all users out at once? I tried resetting IIS - didn't work. I tried deleting all the users' sessions (I'm using a database for session storage) - didn't work.

Any ideas?

Answer 1

With CookieAuthentication, the cookie is simply an encrypted string containing the user's name, roles, and auxilliary data. In short, it identifies the user , not the session. Killing sessions does not invalidate the cookie.

That being said, you can stuff a session identifier or other token in the cookie's auxiliary data, and then validate that during the authentication process. An example of someone trying to this can be found here .

Another option is instead of invalidating sessions you can temporarily disable users in your user repository. Here is an example using ASPNET Identity 2.0.

A third (nuclear) option is to change the machine key on all web servers, which will render any old forms authentication cookies unreadable, forcing all users to sign on again.

Answer 2

You can use CookieAuthenticationOptions.SessionStore Property, to store identity information in server side so you can clear it all when you need.

public void ConfigureServices(IServiceCollection services)
{
    MemoryCacheTicketStore memoryCacheTicketStore = new MemoryCacheTicketStore();
    services.AddSingleton<MemoryCacheTicketStore>(memoryCacheTicketStore);

    services.AddAuthentication().AddCookie(cfg =>
    {
        cfg.SessionStore = memoryCacheTicketStore;
    });
}

public class SessionController : Controller
{
    private readonly MemoryCacheTicketStore memoryCacheTicketStore;

    public SessionController(MemoryCacheTicketStore memoryCacheTicketStore)
    {
        this.memoryCacheTicketStore = memoryCacheTicketStore;
    }

    public Task ClearAllSession()
    {
        return memoryCacheTicketStore.ClearAll();
    }
}

public class MemoryCacheTicketStore : ITicketStore
{
    private const string KeyPrefix = "AuthSessionStore-";
    private IMemoryCache _cache;

    public MemoryCacheTicketStore()
    {
        _cache = new MemoryCache(new MemoryCacheOptions());
    }

    public async Task ClearAll()
    {
        _cache.Dispose();
        _cache = new MemoryCache(new MemoryCacheOptions());
    }

    public async Task<string> StoreAsync(AuthenticationTicket ticket)
    {
        var guid = Guid.NewGuid();
        var key = KeyPrefix + guid.ToString();
        await RenewAsync(key, ticket);
        return key;
    }

    public Task RenewAsync(string key, AuthenticationTicket ticket)
    {
        var options = new MemoryCacheEntryOptions();
        var expiresUtc = ticket.Properties.ExpiresUtc;
        if (expiresUtc.HasValue)
        {
            options.SetAbsoluteExpiration(expiresUtc.Value);
        }
        options.SetSlidingExpiration(TimeSpan.FromHours(1)); // TODO: configurable.

        _cache.Set(key, ticket, options);

        return Task.FromResult(0);
    }

    public Task<AuthenticationTicket> RetrieveAsync(string key)
    {
        AuthenticationTicket ticket;
        _cache.TryGetValue(key, out ticket);
        return Task.FromResult(ticket);
    }

    public Task RemoveAsync(string key)
    {
        _cache.Remove(key);
        return Task.FromResult(0);
    }
}

Answer 3

it's very simple. change the login cookie name

in startup.cs, change the default name to anything.

 options.Cookie.Name = "NewName";

Complete Example:

  services.ConfigureApplicationCookie(options =>
            {
                options.Cookie.Name = "NewName"; //<-- Here
                options.Cookie.HttpOnly = true;
              ...
                options.Events = options.Events ?? new CookieAuthenticationEvents();
                var onForbidden = options.Events.OnRedirectToAccessDenied;
                var onUnauthorized = options.Events.OnRedirectToLogin;
                options.Events.OnRedirectToAccessDenied = (context) => OnRedirect(context, onForbidden, HttpStatusCode.Forbidden);
                options.Events.OnRedirectToLogin = (context) => OnRedirect(context, onUnauthorized, HttpStatusCode.Unauthorized);
            });