1. A method for a directory service that contains a proxy entry corresponding to an external protected resource to provide authentication and authorization functions to a software application, the method comprising the steps of: (A) when the software application needs to access the external protected resource, performing the steps of: (A1) the software application maintaining a resource map to identify a proxy entry that corresponds to the external protected resource; (A2) the software application requesting from the directory service access to the proxy entry that corresponds to the external protected resource; and (A3) if the directory service grants access to the proxy entry that corresponds to the external protected resource, the application accesses the external protected resource.