Implementing IPermission

Question

Hi there,

I'm considering writing a custom IPermission implementation but am not clear as to how it should work. I've already implemented IPrincipal and IIdentity. What I would like to accomplish is to be able to check permissions vis a vis the current IPrincipal's authorizations rather than its roles. Generally, authorizations are read/add-delete/update/none for a given type. So I would like to write something like this:

[CustomPermission(SecurityAction.Demand, Type = typeof(Foo), MinimumAuthorization = AuthorizationFlags.Read)]
public void SomeMethod(){}

Is this possible? I've looked over the code at http://msdn.microsoft.com/en-us/library/system.security.ipermission.aspx. This shows how to implement the interface, but I don't understand how the above pseudo-code would be able to check against the IPrincipal's authorizations for the type.

Answer 1

Your CustomPermission implementation if IPermission.Demand should be able to look at the Thread.Current.CurrentPrincipal, cast that to your custom principal and from there investigate your authourization data.