From the COM+ explorer, bring up the property sheet for the COM+ server application you want to configure. The authentication and impersonation levels can be selected via two dropdown lists at the bottom of the Security page, as shown in Figure 54.1.

Figure 54.1 Server app authentication and impersonation levels.

If you're working with a library application, you've got much less control over your process-wide security settings.

Figure 54.2 shows the controls from the COM+ explorer — note how different they are from those in Figure 54.1.

Figure 54.2 You have less control with a library app.

For library applications, you can't control the default impersonation level, nor can you control the default authentication level. These are process-level settings and are thus controlled by whoever called CoInitializeSecurity (WhatIsCoInitializeSecurity), or, in the case of a COM+ process, by the server application in the process.

The one rather esoteric thing a library application can do is to create a "notch" in the host process's security policy to allow unauthenticated calls to the objects in the library application. You can do this by unchecking the box entitled Enable Authentication. In WhatIsTheComAuthenticationLevel I described how the COM channel rejects incoming calls that are below the process's authentication level. Well, if you uncheck this box, you're allowing requests to enter at any authentication level. Leave this box checked.

PortedBy AnonymousDonor