With all the changes in the security system of .NET 4, the question frequently arises “so, is CAS dead now?”. One of the reasons that this question comes up so frequently, is that the term CAS in the .NET 1 security model was overloaded to refer to many different aspects of the security system: ...

SecAnnotate (available in the final .NET 4 SDK, and in beta form here ) can be used to analyze your assemblies, especially APTCA assemblies in order to find transparency violations without needing code coverage from a test case. Instead, the static analysis provided by SecAnnotate is valuable in ensuring...

One of the design goals of the security transparency system in the CLR is that it should be as static as possible and not rely on dynamic state (such as the call stack) to function. A fallout of this is that we can write tools to analyze assemblies and find transparency violations in the assembly without...

In my last post I talked about the two different security rule sets supported by the v4 CLR .  At a high level, level 1 is the v2.0 security transparency model, and level 2 encompasses the updated v4 security transparency model.  Digging down a little deeper, it’s interesting to look at some...

Earlier this week, we looked at how the v4 CLR continued the evolution of the security transparency model that started in v2 and started evolving with Silverlight in order to make it the primary security enforcement mechanism of the .NET 4 runtime. The result is that the v4 transparency model, while...

Now that we know the basics of security transparency , let's look at how it evolved over time. In .NET v2.0, many of the transparency rules we previously looked at were in place , with the exception of some of the inheritance rules that were introduced for the first time in the Silverlight transparency...

Last time we looked at the set of operations that can only be performed by security critical code . One interesting observation is that just because you are doing one of these operations does not mean that your method in and of itself is security sensitive. For instance, you might implement a method...

One of the biggest changes in the .NET 4 security model is a move toward security transparency as a primary security enforcement mechanism of the platform. As you'll recall, we introduced security transparency in the v2 release of .NET as more of an audit mechanism in order to help make the surface area...

Over the last few weeks we’ve been looking at the changes to security policy in .NET 4, namely that security policy is now in the hands of the host and the operating system. While we’ve looked at how to update code that implicitly uses CAS policy , loads assemblies from remote sources , and explicitly...

Over the last few posts, I’ve been looking at how the update to the CLR v4 security policy interacts with how you write managed code against the v4 .NET Framework.  So far we’ve looked at the implicit uses of CAS policy, such as loading assemblies and creating AppDomains with Evidence and loading...

In my last post about changes to the CLR v4 security policy model, I looked at APIs which implicitly use CAS policy in their operation (such as Assembly.Load overloads that take an Evidence parameter), and how to migrate code that was using those APIs.   There are another set of assembly loads...

A while back I did an interview with Charles Torre   about the changes to security in CLR v4, and he posted it to the Channel 9 videos site yesterday. I start out talking about the security policy changes I've been covering here over the last week, and then transition into an overview of some of...

Kris Makey, who works on the Visual Studio team, has written up a good blog post about the changes you’ll see on the security tab in Visual Studio 10 when it comes to editing permission sets .  He covers what the changes are, and some of the reasons why we worked with the Visual Studio team to make...

Last week we looked at sandboxing and the v4 CLR – with the key change being that the CLR now defers exclusively to the host application when setting up sandboxed domains by moving away from the old CAS policy model, and moving instead to simple sandboxed AppDomains. This leads to an interesting situation...

Yesterday I talked about the changes in security policy for managed applications , namely that managed applications will run with full trust - the same as native applications - when you execute them directly. That change doesn’t mean that managed code can no longer be sandboxed however - far from...

One of the first changes that you might see to security in the v4 CLR is that we’ve overhauled the security policy system.  In previous releases of the .NET Framework, CAS policy applied to all assemblies loaded into an application (except for in simple sandbox domains ). That lead to a lot of interesting...

The first beta of the v4.0 .NET Framework is now available , and with it comes a lot of changes to the CLR's security system. We've updated both the policy and enforcement portions of the runtime in a lot of ways that I'm pretty excited to finally see available. Since there are a lot of security changes...