Porting a security sandbox from .NET 2.0 to .NET 4.0

I have working .NET 2.0 addin that takes an AppDomain created by an external application and applies user-defined security policy (PolicyLevel) by using AppDomain.SetAppDomainPolicy() method. However, this method is obsolete in .NET 4.0 and fails at runtime. Here is a sample code:  

AppDomain domain = ExternalApplication.GetAppDomain(); //This call is from external program which I can’t change.

PolicyLevel pl = GetUserDefinedPolicyLevel()

domain. SetAppDomainPolicy(pl); //This fails in .NET 4.0

  I saw 4.0 example setting AppDomain security by using following call:

AppDomain.CreateDomain( string friendlyName, Evidence securityInfo, AppDomainSetup info, PermissionSet grantSet, params StrongName[] fullTrustAssemblies);

  However, this API is used when an AppDomain is already created. In my situation the addin has to use existing AppDomains.

Another solution I found was to use .config files and add <NetFx40_LegacySecurityPolicy enabled="true" /> element to enforce legacy AppDomain开发者_如何学Go security. This is also not an option in my case since I have an addin for applications and I can’t add .config files.

Is there a way to change AppDomain security at runtime after it has been created in .NET 4.0?

I hope that this should be possible, since otherwise it would look like 4.0 removed the ability to tighten security at run-time.

Thanks