Claim based authorization design for conditional edit operation in ASP.NET MVC App

Question

Designing an ASP.Net MVC application authorization using claim based model. Lets say that we have an object called - Product. Typically, there are 4 different actions - Crea

Answer 1

For first part of your question, Claim based authorization, I have already answered it in this similar question. And I am not going to repeat here.

But for your another rules like products editable only by owner. You could write separate AuthorizeAttribute for each rule and apply them on your Actions consider this as an simple example:

using Microsoft.AspNet.Identity;
public class OwnerAuthorizeAttribute : AuthorizeAttribute
{
    private string _keyName;
    public bool IsPost { get; set; }

    public OwnerAuthorizeAttribute(string keyName)
    {
        _keyName = keyName;
    }

    protected override bool AuthorizeCore(HttpContextBase httpContext)
    {
        // imagine you have a service which could check owner of 
        // product based on userID and ProductID

        return httpContext.User.Identity.IsAuthenticated
            && this.ContainsKey
            && _productService.IsOwner(httpContext.User.Identity.GetUserId(),
                int.Parse(this.KeyValue.ToString()));
    }

    private bool ContainsKey
    {
        get
        {
            return IsPost
                ? HttpContext.Current.Request.Form.AllKeys.Contains(_keyName)
                // for simplicity I just check route data 
                // in real world you might need to check query string too 
                : ((MvcHandler)HttpContext.Current.Handler).RequestContext
                     .RouteData.Values.ContainsKey(_keyName);
        }
    }
    private object KeyValue
    {
        get
        {
            return IsPost
                ? HttpContext.Current.Request.Form[_keyName]
                // for simplicity I just check route data 
                // in real world you might need to check query string too 
                : ((MvcHandler)HttpContext.Current.Handler)
                    .RequestContext.RouteData.Values[_keyName];
        }
    }
}

You could repeat same pattern to your other rules too.

And you could simply apply your custom attributes to your actions:

[OwnerAuthorize("id")]
public ActionResult Edit(int id)
{
    // your code
}

[HttpPost]
// double checking in post back too 
[OwnerAuthorize("id", IsPost = true)]
public ActionResult Edit(Product product)
{
    // your code
}

It is obvious you could apply more then one AuthorizeAttribute to your actions. In this case all of them must return true.

[ClaimsAuthorize("Product", "EDIT")]
[OwnerAuthorize("id")]
[YetOtherAuthorize]
public ActionResult MyFancyAction(int id)
{
}