To make the most of the security configurations COM+ has to offer, you need to be familiar with a few basic terms and concepts. The rest of this chapter makes frequent use of these terms.
A security identity is a valid account used to identify a user. The account can be local or an account on a domain server. Every COM+ entity, be it a client or an object, must have an identity associated with it so that COM+ can determine what that entity is capable of accessing. In Windows, all objects in the same process share the same identity, unless they make an explicit attempt to assume a different identity. You can configure a COM+ server application to always run under a particular identity or to run under the identity of the user who is currently logged on that Windows station. Objects from a COM+ library application run under the identity of the hosting process by default.
Authentication has two facets. The first is the process by which COM+ verifies that the callers are who they claim to be. The second is the process by which COM+ ensures the integrity of the data sent by the callers. COM+ authentication relies on the underlying security provider—in most cases Windows 2000 built-in security.
In the Windows default security provider, the challenge/response protocol is used to authenticate the caller’s identity. Given that all callers must have a security identity, if the callers are who they say they are, then they must know the ...