Custom Membership Provider with Windows authetication

Question

I've created my own Membership Provider where I have below method:

public override bool ValidateUser(string username, string password)
{
    if (username == "John")
        return true;
    else
        return false;
}

I've also added below lines to web.config file:

<authentication mode="Windows" />
    <authorization>
      <deny users="?" />
    </authorization>
    <membership defaultProvider="MembershipProviter">
      <providers>
        <clear />
        <add name="cls_MembershipProvider" type="App.cls_MembershipProvider" 
             enablePasswordRetrieval="false" 
             enablePasswordReset="false" 
             requiresQuestionAndAnswer="false" 
             requiresUniqueEmail="false" 
             maxInvalidPasswordAttempts="5" 
             minRequiredPasswordLength="5" 
             minRequiredNonalphanumericCharacters="0" 
             passwordAttemptWindow="10" 
             applicationName="App"
             />
      </providers>
    </membership>

As you may notice I am using Windows authentication and I don't have Log In page. By default all users from Active Directory has access to the page. My goal is to check if user exist in my database. Everywhere I searched, there is Log In page, where ValidateUser is launched. My question is where should I implement ValidateUser method as I don't have Log In page. I just want to have control on each Controler method so I could add [Authorize] so only users from my database can actually access the page.

Answer 1

You can define your own CustomAuthorizeAttribute deriving from AuthorizeAttribute. Override OnAuthorization method to perform validation using details in context. Apply your custom filter on top of each controller or define a BaseController and derive your controllers from BaseController. For example you can define a class like:

[AttributeUsage(AttributeTargets.Class | AttributeTargets.Method, Inherited = true, AllowMultiple = false)]
public sealed class RdbiAuthorizationAttribute : AuthorizeAttribute
{
    /// <summary>
    /// Verifies that the logged in user is a valid organization user.
    /// </summary>
    /// <param name="filterContext"></param>
    public override void OnAuthorization(AuthorizationContext filterContext)
    {
        Guard.ArgumentNotNull(filterContext, "filterContext");
        Guard.ArgumentNotNull(filterContext.Controller, "filterContext.Controller");

        bool skipAuthorization = filterContext.ActionDescriptor.IsDefined(
            typeof(AllowAnonymousAttribute), inherit: true)
                                 || filterContext.ActionDescriptor.ControllerDescriptor.IsDefined(
                                     typeof(AllowAnonymousAttribute), inherit: true);

        if (skipAuthorization)
        {
            return;
        }

        if (string.IsNullOrEmpty(filterContext.HttpContext.User.Identity.Name))
            throw new AuthenticationException("User must be logged in to access this page.");

        var controller = filterContext.Controller as BaseController;
        if (controller != null)
        {
            var user = controller.GetUser();

            if (user == null)
            {
                throw new InvalidOperationException(string.Format("Logged in user {0} is not a valid user", filterContext.HttpContext.User.Identity.Name));
            }
        }

        base.OnAuthorization(filterContext);
    }
}

Then you can define controller like:

[RdbiAuthorization]
public class BaseController : Controller
{
}

public class MyTestController : BaseController
{
}