/*
 * $Header: /home/cvs/jakarta-tomcat-catalina/catalina/src/share/org/apache/catalina/Realm.java,v 1.6 2003/12/11 05:50:39 billbarker Exp $
 * $Revision: 1.6 $
 * $Date: 2003/12/11 05:50:39 $
 *
 * ====================================================================
 *
 * The Apache Software License, Version 1.1
 *
 * Copyright (c) 1999 The Apache Software Foundation.  All rights
 * reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution, if
 *    any, must include the following acknowlegement:
 *       "This product includes software developed by the
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
 *
 * 4. The names "The Jakarta Project", "Tomcat", and "Apache Software
 *    Foundation" must not be used to endorse or promote products derived
 *    from this software without prior written permission. For written
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache"
 *    nor may "Apache" appear in their names without prior written
 *    permission of the Apache Group.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
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 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
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 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the Apache Software Foundation.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 *
 * [Additional notices, if required by prior licensing conditions]
 *
 */


package org.apache.catalina;

import java.beans.PropertyChangeListener;
import java.io.IOException;
import java.security.Principal;
import java.security.cert.X509Certificate;

import org.apache.catalina.deploy.SecurityConstraint;
/**
 * A <b>Realm</b> is a read-only facade for an underlying security realm
 * used to authenticate individual users, and identify the security roles
 * associated with those users.  Realms can be attached at any Container
 * level, but will typically only be attached to a Context, or higher level,
 * Container.
 *
 * @author Craig R. McClanahan
 * @version $Revision: 1.6 $ $Date: 2003/12/11 05:50:39 $
 */

public interface Realm {


    // ------------------------------------------------------------- Properties


    /**
     * Return the Container with which this Realm has been associated.
     */
    public Container getContainer();


    /**
     * Set the Container with which this Realm has been associated.
     *
     * @param container The associated Container
     */
    public void setContainer(Container container);


    /**
     * Return descriptive information about this Realm implementation and
     * the corresponding version number, in the format
     * <code>&lt;description&gt;/&lt;version&gt;</code>.
     */
    public String getInfo();


    // --------------------------------------------------------- Public Methods

    
    /**
     * Add a property change listener to this component.
     *
     * @param listener The listener to add
     */
    public void addPropertyChangeListener(PropertyChangeListener listener);


    /**
     * Return the Principal associated with the specified username and
     * credentials, if there is one; otherwise return <code>null</code>.
     *
     * @param username Username of the Principal to look up
     * @param credentials Password or other credentials to use in
     *  authenticating this username
     */
    public Principal authenticate(String username, String credentials);


    /**
     * Return the Principal associated with the specified username and
     * credentials, if there is one; otherwise return <code>null</code>.
     *
     * @param username Username of the Principal to look up
     * @param credentials Password or other credentials to use in
     *  authenticating this username
     */
    public Principal authenticate(String username, byte[] credentials);


    /**
     * Return the Principal associated with the specified username, which
     * matches the digest calculated using the given parameters using the
     * method described in RFC 2069; otherwise return <code>null</code>.
     *
     * @param username Username of the Principal to look up
     * @param digest Digest which has been submitted by the client
     * @param nonce Unique (or supposedly unique) token which has been used
     * for this request
     * @param realm Realm name
     * @param md5a2 Second MD5 digest used to calculate the digest :
     * MD5(Method + ":" + uri)
     */
    public Principal authenticate(String username, String digest,
                                  String nonce, String nc, String cnonce,
                                  String qop, String realm,
                                  String md5a2);


    /**
     * Return the Principal associated with the specified chain of X509
     * client certificates.  If there is none, return <code>null</code>.
     *
     * @param certs Array of client certificates, with the first one in
     *  the array being the certificate of the client itself.
     */
    public Principal authenticate(X509Certificate certs[]);
    
    /**
     * Return the SecurityConstraints configured to guard the request URI for
     * this request, or <code>null</code> if there is no such constraint.
     *
     * @param request Request we are processing
     */
    public SecurityConstraint [] findSecurityConstraints(HttpRequest request,
                                                     Context context);
    /**
     * Perform access control based on the specified authorization constraint.
     * Return <code>true</code> if this constraint is satisfied and processing
     * should continue, or <code>false</code> otherwise.
     *
     * @param request Request we are processing
     * @param response Response we are creating
     * @param constraint Security constraint we are enforcing
     * @param The Context to which client of this class is attached.
     *
     * @exception IOException if an input/output error occurs
     */
    public boolean hasResourcePermission(HttpRequest request,
                                         HttpResponse response,
                                         SecurityConstraint [] constraint,
                                         Context context)
        throws IOException;
    
    
    /**
     * Return <code>true</code> if the specified Principal has the specified
     * security role, within the context of this Realm; otherwise return
     * <code>false</code>.
     *
     * @param principal Principal for whom the role is to be checked
     * @param role Security role to be checked
     */
    public boolean hasRole(Principal principal, String role);

        /**
     * Enforce any user data constraint required by the security constraint
     * guarding this request URI.  Return <code>true</code> if this constraint
     * was not violated and processing should continue, or <code>false</code>
     * if we have created a response already.
     *
     * @param request Request we are processing
     * @param response Response we are creating
     * @param constraint Security constraint being checked
     *
     * @exception IOException if an input/output error occurs
     */
    public boolean hasUserDataPermission(HttpRequest request,
                                         HttpResponse response,
                                         SecurityConstraint []constraint)
        throws IOException;
    
    /**
     * Remove a property change listener from this component.
     *
     * @param listener The listener to remove
     */
    public void removePropertyChangeListener(PropertyChangeListener listener);


}
