Improving Web Application Security: Threats and - CGISecurity

150 Part III: Building Secure Web ApplicationsPrivileged ResourcesThe types of resources for which your code requires code access security permissionsinclude the file system, databases, registry, event log, Web services, sockets, DNSdatabases, directory services, and environment variables.Privileged OperationsOther privileged operations for which your code requires code access securitypermissions include calling unmanaged code, using serialization, using reflection,creating and controlling application domains, creating Principal objects, andmanipulating security policy.For more information about the specific types of code access security permissionsrequired for accessing resources and performing privileged operations, see“Privileged Code” in Chapter 8, “Code Access Security in Practice.”Assembly Design ConsiderationsOne of the most significant issues to consider at design time is the trust level of yourassembly’s target environment, which affects the code access security permissionsgranted to your code and to the code that calls your code. This is determined by codeaccess security policy defined by the administrator, and it affects the types ofresources your code is allowed to access and other privileged operations it canperform.When designing your assembly, you should:● Identify privileged code● Identify the trust level of your target environment● Sandbox highly privileged code● Design your public interfaceIdentify Privileged CodeIdentify code that accesses secured resources or performs security sensitiveoperations. This type of code requires specific code access security permissions tofunction.