Weird behaviour of the PrincipalPermission attribute

11 Oct 2006 6:47 AM

Amid

Let's suppose we have the following class:

[PrincipalPermission(SecurityAction.Demand, Authenticated = true)]
public class TestClass
{
    [PrincipalPermission(SecurityAction.Demand, Role = "Administrator")]
    public void CallMe()
    {
      PrincipalPermission MyPermission = new PrincipalPermission("User",
"Administrator");
      MyPermission.Demand();
    }
}

And the following code snippet that uses it:

class Class1
{
    [STAThread]
    static void Main(string[] args)
    {
      SetPrincipal("bad user");
      TestClass tp = new TestClass();
      tp.CallMe();
    }

    private static void SetPrincipal(string role)
    {
      GenericIdentity myIdentity = new GenericIdentity("User");

      String[] myStringArray = { role };
      GenericPrincipal myPrincipal = new GenericPrincipal(myIdentity,
myStringArray);

      Thread.CurrentPrincipal = myPrincipal;
    }
}

The weird thing about this code that declarative permission check allows to
call method TestClass.CallMe() (though it is not supposed to) but imperative
check within this method throws an exception and behaves correctly.
Now if I remove declarative permission check from the class declaration and
leave one on the method everything works as expected.

Any thoughts will be appreciated. Thanks in advance.

14 Oct 2006 9:14 PM

Nicole Calinoiu

Declarative PrincipalPermission demands are unioned within a class. If you
mark a class with an authenticated demand, any authenticated user will be
able to use any class member. Imperative demands are independent of
declarative demands, which is why yours blocks access despite the
class-level demand.

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"Amid" <A***@discussions.microsoft.com> wrote in message
news:E4697750-BC34-458A-8970-DE65744F547E@microsoft.com...
> Let's suppose we have the following class:
>
> [PrincipalPermission(SecurityAction.Demand, Authenticated = true)]
> public class TestClass
> {
>    [PrincipalPermission(SecurityAction.Demand, Role = "Administrator")]
>    public void CallMe()
>    {
>      PrincipalPermission MyPermission = new PrincipalPermission("User",
> "Administrator");
>      MyPermission.Demand();
>    }
> }
>
> And the following code snippet that uses it:
>
> class Class1
> {
>    [STAThread]
>    static void Main(string[] args)
>    {
>      SetPrincipal("bad user");
>      TestClass tp = new TestClass();
>      tp.CallMe();
>    }
>
>    private static void SetPrincipal(string role)
>    {
>      GenericIdentity myIdentity = new GenericIdentity("User");
>
>      String[] myStringArray = { role };
>      GenericPrincipal myPrincipal = new GenericPrincipal(myIdentity,
> myStringArray);
>
>      Thread.CurrentPrincipal = myPrincipal;
>    }
> }
>
> The weird thing about this code that declarative permission check allows
> to
> call method TestClass.CallMe() (though it is not supposed to) but
> imperative
> check within this method throws an exception and behaves correctly.
> Now if I remove declarative permission check from the class declaration
> and
> leave one on the method everything works as expected.
>
> Any thoughts will be appreciated. Thanks in advance.