# TrustedClientPlugin.java

    /*
    ** Module   : TrustedClientPlugin.java
    ** Abstract : Custom authentication plugin that allows a user to be
    **            automatically logged in (without password!) by specifying the
    **            target user id when starting P2J client.
    **
    ** Copyright (c) 2010-2017, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- -------------------------------- Description --------------------------------
    ** 001 SVL 20100916 Created the initial version. Allows a user to be
    **                  automatically logged in.
    ** 002 SVL 20100923 Changed to conform the new Authenticator API.
    ** 003 OM  20131018 Updated to conform the new Authenticator API.
    */
    /*
    ** This program is free software: you can redistribute it and/or modify
    ** it under the terms of the GNU Affero General Public License as
    ** published by the Free Software Foundation, either version 3 of the
    ** License, or (at your option) any later version.
    **
    ** This program is distributed in the hope that it will be useful,
    ** but WITHOUT ANY WARRANTY; without even the implied warranty of
    ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    ** GNU Affero General Public License for more details.
    **
    ** You may find a copy of the GNU Affero GPL version 3 at the following
    ** location: https://www.gnu.org/licenses/agpl-3.0.en.html
    **
    ** Additional terms under GNU Affero GPL version 3 section 7:
    **
    **   Under Section 7 of the GNU Affero GPL version 3, the following additional
    **   terms apply to the works covered under the License.  These additional terms
    **   are non-permissive additional terms allowed under Section 7 of the GNU
    **   Affero GPL version 3 and may not be removed by you.
    **
    **   0. Attribution Requirement.
    **
    **     You must preserve all legal notices or author attributions in the covered
    **     work or Appropriate Legal Notices displayed by works containing the covered
    **     work.  You may not remove from the covered work any author or developer
    **     credit already included within the covered work.
    **
    **   1. No License To Use Trademarks.
    **
    **     This license does not grant any license or rights to use the trademarks
    **     Golden Code, FWD, any Golden Code or FWD logo, or any other trademarks
    **     of Golden Code Development Corporation. You are not authorized to use the
    **     name Golden Code, FWD, or the names of any author or contributor, for
    **     publicity purposes without written authorization.
    **
    **   2. No Misrepresentation of Affiliation.
    **
    **     You may not represent yourself as Golden Code Development Corporation or FWD.
    **
    **     You may not represent yourself for publicity purposes as associated with
    **     Golden Code Development Corporation, FWD, or any author or contributor to
    **     the covered work, without written authorization.
    **
    **   3. No Misrepresentation of Source or Origin.
    **
    **     You may not represent the covered work as solely your work.  All modified
    **     versions of the covered work must be marked in a reasonable way to make it
    **     clear that the modified work is not originating from Golden Code Development
    **     Corporation or FWD.  All modified versions must contain the notices of
    **     attribution required in this license.
    */
    package com.goldencode.p2j.security;

    import com.goldencode.p2j.net.SessionListener;
    import java.io.*;
    import java.util.*;

    /**
     * Custom authentication plugin that allows a user to be automatically logged
     * in (without password!) by specifiying the target user id when starting P2J
     * client. An example: <code>./client.sh -u userid</code>
     * <p>
     * In order to be able to log in without password, this plugin should be
     * specified as the auth plugin for the target users.
     * <p>
     * This plugin is **THE FORM OF DISABLING P2J SERVER'S SECURITY** for the
     * given set of users.
      *
     */
    public class TrustedClientPlugin
    implements Authenticator
    {
       /** The value of "option" node from AuthPlugin for this Authenticator */
       private String authOption = null;

       /**
        * Implements client side custom authentication logic.
        *
        * @param    parameters
        *           Additional configuration parameters. This plugin uses
        *           "subjectId" parameter which corresponds the name of the user
        *           account to be used.
        * @param    code
        *           Not used.
        *
        * @return   Array of bytes to be transmitted to the server as the
        *           authorization input. Contains target user name.
        */
       @Override
       public byte[] clientAuthHook(Map<String, Object> parameters, int code)
       {
          String subjectId = "";
          if (parameters != null)
             subjectId = (String) parameters.get("subjectId");
          if (subjectId == null)
             subjectId = "";

          ByteArrayOutputStream bos = new ByteArrayOutputStream();
          DataOutputStream      dos = new DataOutputStream(bos);

          try
          {
             dos.writeUTF(subjectId);
          }
          catch (IOException ioe)
          {
             return new byte[0];
          }

          return bos.toByteArray();
       }

       /**
        * Finalizes any resources allocated during authentication by the client.
        */
       @Override
       public void clientFinalize()
       {
       }

       /**
        * Implements server side custom authentication logic.
        * <p>
        * Accepts the byte array produced by the client side authentication hook
        * as authentication input and custom parameters.
        *
        * @param    auth
        *           The authorization input from the client.
        * @param    entity
        *           The entity to be authenticated. Not used.
        *
        * @return   The result of the authentication processing.
        */
       @Override
       public AuthenticationResponse serverAuthHook(byte[] auth, String entity)
       {
          // parse the byte array input
          ByteArrayInputStream bis = new ByteArrayInputStream(auth);
          DataInputStream dis = new DataInputStream(bis);

          String userId;

          try
          {
             userId = dis.readUTF();
          }
          catch (IOException ioe)
          {
             return new AuthenticationResponse(null, AUTH_RESULT_UNSPECIFIED_FAILURE);
          }

          // validation of account type and auth method (common for all plugins)
          // will be performed into SecurityManager.runCustomServerHook
          return new AuthenticationResponse(userId, AUTH_RESULT_SUCCESS);
       }

       /**
        * Always returns <code>null</code>.
        *
        * @return  Always <code>null</code>.
        */
       @Override
       public SessionListener getSessionListener()
       {
          return null;
       }

       /**
        * Returns a set of entities that this class handles. The list of entities / parameters will
        * be configured using other ways.
        *
        * @return  A set with the value of option that was configured or an empty set if option was
        *          not configured.
        */
       @Override
       public Set<String> getAuthenticationEntities()
       {
          Set<String> ret = new HashSet<>();
          if (authOption != null)
          {
             ret.add(authOption);
          }
          return ret;
       }

       /**
        * Configures the Authenticator by setting the "option" parameter from directory.xml.
        *
        * @param   option
        *          The value of "option" entry for the auth plugin.
        */
       @Override
       public void configure(String option)
       {
          this.authOption = option;
       }
    }