Security and Cryptography

Abstract

Prior to version 4.0, the .NET Framework incorporated two complementary security models that addressed user and code security: role-based security (RBS) and code access security (CAS). With version 4.0, CAS has been deprecated. The previous edition of this book included a number of CAS recipes (11-1 through to 11-7), and we have included them in this new version because of the number of developers still using .NET 3.5 or earlier, where CAS still has a significant function. The C# compiler will show deprecation warnings if you use CAS in a project. You can prevent these errors by targeting your project at an earlier version of the .NET Framework on the Application tab. You can enable CAS in your .NET 4.0 projects with the NetFx40_LegacySecurityPolicy configuration element in the app.config file—for example: