its message processing either by returning an AuthStatus value or by throwing an
 AuthException.</div>
<dl>
<dt><span class="paramLabel">Parameters:</span></dt>
<dd><code>messageInfo</code> - A contextual object that encapsulates the client request and server response objects, and that may
 be used to save state across a sequence of calls made to the methods of this interface for the purpose of completing
 a secure message exchange.</dd>
<dd><code>serviceSubject</code> - A Subject that represents the source