Authentication and Authorization

There are some special things you need to be aware of before you start working with the authentication.

DotVVM doesn't implement any specific authentication features, however it can use advantage of the common ASP.NET authentication system. The fact, whether the user is authenticated and in which role he is, is determined by the OwinContext.User property. It's the same as in other ASP.NET technologies.

Restricting Access to ViewModels and ViewModel Methods

In DotVVM, you can use the [Authorize] attribute from the DotVVM.Framework.Runtime.Filters namespace. You can use it to decorate the viewmodel class, or a specific viewmodel method referenced by a command binding.

Only the method called from a command binding and the page viewmodel class are checked for the Authorize attribute. If you call the method from C# code, the attribute is not checked automatically.

using System;
using System.Threading.Tasks;
using DotvvmWeb.BL.Facades;
using DotVVM.Framework.Runtime.Filters;

namespace DotvvmDemo.ViewModels
{
    [Authorize]
    public class AdminViewModelBase : DotvvmViewModelBase
    {
        // The page with this viewmodel will return 403 Forbidden
        // if the user is not authenticated.

        // No commands will be accepted.
    }
}

Also, you can limit the access to a specific user roles.

using System;
using System.Threading.Tasks;
using DotVVM.Framework.ViewModel;
using DotVVM.Framework.Runtime.Filters;

namespace DotvvmDemo.ViewModels
{
    public class AdminViewModelBase : DotvvmViewModelBase
    {
        [Authorize(Roles = new[] { "Admin" })]
        public void DeleteUser(int id)
        {
            // Only the users with the Admin role will be able
            // to call this method from the command binding.
        }

        // Please note that if you call the DeleteUser from your own code, the Authorize attribute will not be checked.
    }
}

You can use the Microsoft.Owin.Security NuGet package for the authentication. You can find more details in the Using OWIN Security for Authentication chapter.