Programming .NET Components, 2nd Edition

The .NET Security Architecture

.NET component-oriented security is based on an elegant concept: using an administration tool, the system administrator grants assemblies certain permissions to perform operations with external entities such as the filesystem, the Registry, the user interface, and so on. .NET provides the system administrator with multiple ways to identify which assembly gets granted what permission and what evidence the assembly needs to provide in order to establish its identity. At runtime, whenever an assembly tries to perform a privileged operation or access a resource, .NET verifies that the assembly and its calling assemblies have permission to perform that operation. Although the idea is intuitive enough, there are a substantial number of new terms and concepts to understand before configuring .NET security for your own applications. The rest of this section describes the elements of the .NET security architecture. The next sections describe how to administratively configure security and take programmatic control over security.

Permissions

A permission is a grant to perform a specific operation. Permissions have both a type and a scope. A file I/O permission is different from a user-interface permission in type because they control access to different types of resources. Similarly, a reflection permission is different from an unmanaged code access permission because they control the execution of different types of operations. In scope, a permission can be very ...