3.1.1.4.2 Impersonate Client

These extensions allow higher-layer protocols to use a security context to make runtime authorization decisions on the server. When a higher-layer protocol requests the RPC runtime to impersonate the client on the server, the RPC local server interface retrieves the security context (section 3.3.1.5.2.2) and makes it available to the higher-layer protocol in an implementation-specific manner for the higher-layer protocol's use in future authorization decisions. If a security context is not available for the connection, the attempt to impersonate the client fails. See section 3.3.3.4.3 for details on the higher-level trigger event associated with retrieving the client's identity.