What Does Code Access Security (CAS) Mean?
Code access security (CAS) is a security mechanism by which the common language runtime (CLR) of the .NET framework can restrict the managed code to execute operations with a limited set of permissions.
CAS enforces security policies in the .NET framework by preventing unauthorized access to protected resources and operations. Unlike traditional security methods, where user credentials are obtained from the user, CAS is designed to address the issues faced when obtaining code from external sources, which contain bugs and vulnerabilities. These bugs and vulnerabilities may make a user’s system vulnerable to malicious code, which may be performing tasks without the user knowing it. CAS actually knows and allows only those operations a given user’s code can and cannot perform. This feature is applicable to all managed code targeting the CLR.
CAS provides evidence-based security built on a layer above the security provided by the Windows operating system. While Windows is based on the permissions of the user, CAS is based on the evidence for the assembly. The assembly contains the permissions defined in the security policy and forms the basis for allowing code to execute necessary actions.
Techopedia Explains Code Access Security (CAS)
CAS is built on the following elements, among others:
