/*
 * The contents of this file are subject to the terms of the Common Development and
 * Distribution License (the License). You may not use this file except in compliance with the
 * License.
 *
 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
 * specific language governing permission and limitations under the License.
 *
 * When distributing Covered Software, include this CDDL Header Notice in each file and include
 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
 * Header, with the fields enclosed by brackets [] replaced by your own identifying
 * information: "Portions Copyright [year] [name of copyright owner]".
 *
 * Copyright 2006-2008 Sun Microsystems, Inc.
 * Portions Copyright 2014-2016 ForgeRock AS.
 */
package org.opends.server.api;
import org.forgerock.i18n.LocalizableMessage;



import java.security.cert.Certificate;
import java.util.List;

import org.forgerock.opendj.server.config.server.CertificateMapperCfg;
import org.forgerock.opendj.config.server.ConfigException;
import org.opends.server.types.DirectoryException;
import org.opends.server.types.Entry;
import org.opends.server.types.InitializationException;


/**
 * This class defines the set of methods and structures that must be
 * implemented by a Directory Server module that implements the
 * functionality required to uniquely map an SSL client certificate to
 * a Directory Server user entry.
 *
 * @param  <T>  The type of configuration handled by this certificate
 *              mapper.
 */
@org.opends.server.types.PublicAPI(
     stability=org.opends.server.types.StabilityLevel.VOLATILE,
     mayInstantiate=false,
     mayExtend=true,
     mayInvoke=false)
public abstract class CertificateMapper
       <T extends CertificateMapperCfg>
{
  /**
   * Initializes this certificate mapper based on the information in
   * the provided configuration entry.
   *
   * @param  configuration  The configuration that should be used to
   *                        intialize this certificate mapper.
   *
   * @throws  ConfigException  If the provided entry does not contain
   *                           a valid certificate mapper
   *                           configuration.
   *
   * @throws  InitializationException  If a problem occurs during
   *                                   initialization that is not
   *                                   related to the server
   *                                   configuration.
   */
  public abstract void initializeCertificateMapper(T configuration)
         throws ConfigException, InitializationException;



  /**
   * Indicates whether the provided configuration is acceptable for
   * this certificate mapper.  It should be possible to call this
   * method on an uninitialized certificate mapper instance in order
   * to determine whether the certificate mapper would be able to use
   * the provided configuration.
   * <BR><BR>
   * Note that implementations which use a subclass of the provided
   * configuration class will likely need to cast the configuration
   * to the appropriate subclass type.
   *
   * @param  configuration        The certificate mapper configuration
   *                              for which to make the determination.
   * @param  unacceptableReasons  A list that may be used to hold the
   *                              reasons that the provided
   *                              configuration is not acceptable.
   *
   * @return  {@code true} if the provided configuration is acceptable
   *          for this certificate mapper, or {@code false} if not.
   */
  public boolean isConfigurationAcceptable(
                      CertificateMapperCfg configuration,
                      List<LocalizableMessage> unacceptableReasons)
  {
    // This default implementation does not perform any special
    // validation.  It should be overridden by certificate mapper
    // implementations that wish to perform more detailed validation.
    return true;
  }



  /**
   * Performs any finalization that may be necessary for this
   * certificate mapper.  By default, no finalization is performed.
   */
  public void finalizeCertificateMapper()
  {
    // No implementation is required by default.
  }



  /**
   * Establishes a mapping between the information in the provided
   * certificate chain and a single user entry in the Directory
   * Server.
   *
   * @param  certificateChain  The certificate chain presented by the
   *                           client during SSL negotiation.  The
   *                           peer certificate will be listed first,
   *                           followed by the ordered issuer chain
   *                           as appropriate.
   *
   * @return  The entry for the user to whom the mapping was
   *          established, or {@code null} if no mapping was
   *          established and no special message is required to send
   *          back to the client.
   *
   * @throws  DirectoryException  If a problem occurred while
   *                              attempting to establish the mapping.
   *                              This may include internal failures,
   *                              a mapping which matches multiple
   *                              users, or any other case in which an
   *                              error message should be returned to
   *                              the client.
   */
  public abstract Entry mapCertificateToUser(Certificate[]
                                                  certificateChain)
         throws DirectoryException;
}