I come from an ASP.NET background and find the entire roles based authorization scheme limiting to say the least. I've read about Microsoft's new Identity Model and the Geneva Framework with its Claims based architecture but it seems overly complex.
In general, I'd like to know more about possible authorization architectures to find out what fits my needs best.
For instance, application wide roles seem to be good enough if you want to create, well, application wide roles, like "Administrator". But what if I have ie. an project management application with project entities where every project has its own set of roles ("Editor" on project A and "Photographer" on project B for instance) and associated permissions.
Are there any books on this subject that you could recommend?
Since you're coming from an ASP.NET background, probably the most specifically focused book on the subject of security/authorization within the ASP.NET framework is:
Professional ASP.NET 3.5 Security, Membership, and Role Management with C# and VB
(or it's previous editions that target ASP.NET 2.0 etc.)
There is also the older:
Programming .NET Security
However, these books will simply detail the existing authentication and authorization mechanisms as they exist within ASP.NET membership model and, as you say, are heavily based upon a user/role setup.
If you're looking to stay specifically within the Microsoft/.NET world, one thing that could be worth looking into the the federated security model that can be employed by technologies such as WCF (Windows Communication Foundation). This mechanism allows a relatively lightweight approach to security management and makes it easier to accomplish the kind of thing you're after in your example (ProjectA: Editor / ProjectB: Photographer).
Some links on this are:
Federation (from MSDN)
Federation and Issued Tokens
patterns & practices: WCF Security Guidance Learning WCF Book - Federated Security Section
If you're after a more general or generic approach to security and authentication/authorization mechanisms that is fairly platform agnostic, some good resources / books would be:
Designing Security Architecture Solutions
(This book details different security concepts and architectures not only for authenticating/authorizing users but also for concepts such as code access security)
There is also:
Enterprise Security Architecture: A Business-Driven Approach
(As it's name suggests, it's a bit more "business" focused, and does primarily focus on the SABSA (Sherwood Applied Business Security Architecture) methodology)