/*
 * 
 * Copyright 2004 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * The contents of this file are subject to the Sun Community Source
 * License v3.0/Jini Technology Specific Attachment v 1.0 (the
 * "License"). You may not use this file except in compliance with the
 * License. You may obtain a copy of the License at
 * http://wwws.sun.com/software/jini/licensing/SCSL3_JiniTSA1.html.
 * Software distributed under the License is distributed on an "AS IS"
 * basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
 * the License for the specific language governing rights and limitations
 * under the License.
 * 
 * The Reference Code is Jini Technology Core Platform code, v2.0. The
 * Developer of the Reference Code is Sun Microsystems, Inc.
 * 
 * Contributor(s): Sun Microsystems, Inc.
 * 
 * The contents of this file comply with the Jini Technology Core
 * Platform Compatibility Kit, v2.0A.
 * 
 * Tester(s): Sun Microsystems, Inc.
 * 
 * Test Platform(s):
 * Java 2 SDK, Standard Edition, Version 1.4.2_03 for Solaris(TM)SPARC/x86
 * Java 2 SDK, Standard Edition, Version 1.4.2_03 for Linux (Intel x86)
 * Java 2 SDK, Standard Edition, Version 1.4.2_03 for Windows (Intel Platform)
 * 
 */

package com.sun.jini.discovery;

import javax.security.auth.Subject;

/**
 * Interface for approving or rejecting client subjects during unicast
 * discovery and decoding of multicast requests.  Instances of this interface
 * are passed to the {@link Discovery#decodeMulticastRequest
 * decodeMulticastRequest} and {@link Discovery#handleUnicastDiscovery
 * handleUnicastDiscovery} methods of the {@link Discovery} class as a means of
 * controlling whether or not data can be accepted from or exchanged with a
 * client authenticated as the given subject.
 *
 * @author Sun Microsystems, Inc.
 * @since 2.0
 */
public interface ClientSubjectChecker {

    /**
     * Checks whether or not to permit exchanging or accepting data with/from a
     * client authenticated as the given subject.  The passed subject is
     * <code>null</code> if the client is unauthenticated; if
     * non-<code>null</code>, it must be read-only.  Returns normally if the
     * subject is acceptable; throws a <code>SecurityException</code> if not.
     *
     * @param subject the client subject to check
     * @throws SecurityException if the client subject check fails
     * @throws IllegalArgumentException if the given subject is not read-only
     */
    void checkClientSubject(Subject subject);
}
