# DefaultLoginPanel.java

    /*
    ** Module   : DefaultLoginPanel.java
    ** Abstract : implements a login panel to get the userid/pw when there is no
    **            custom panel provided
    **
    ** Copyright (c) 2013-2023, Golden Code Development Corporation.
    **
    ** -#- -I- --Date-- -------------------------------- Description -------------------------------
    ** 001 GES 20111019 First version.
    ** 002 OM  20131018 Updated to conform the new Authenticator API.
    ** 003 GES 20140626 Renamed color attributes to match naming standards.
    ** 004 CA  20140805 ThinClient is explicitly imported, to isolate ChUI class usage outside of ChUI
    **                  packages.
    ** 005 EVL 20140829 All widgets in login screen must have predefined ID.  Including space and skip
    **                  never leaving -1 as ID when passing widget config to ScreenDefinition class.
    **                  We can not use the new widget ID allocation here because there is no
    **                  LogicalTerminal at this time.
    ** 006 CA  20140926 Added shared widget configuration support, to allow GUI/ChUI concrete
    **                  implementation for the same widget ID.  Refactored the widget configuration
    **                  classes: all fields were made public; these classes need to be as dumb as
    **                  possible, all logic related to setting/getting a certain field should be at
    **                  the widget or at the caller. Refs #2254
    ** 007 VIG 20140911 Fixed status method calls with corresponding arguments for changed signature.
    ** 008 CA  20141119 Refactored drawing code to enable multiple OS windows, for GUI support.  Misc
    **                  changes/fixes related to drawing on multiple windows.
    ** 009 HC  20150405 Refactoring of config coordinate fields.
    ** 010 HC  20151013 Changes to extend GUI multi-window focus management and ACTIVE-WINDOW system
    **                  handle processing to modal windows.
    ** 011 EVL 20160726 Now we use screen buffer array in waitFor() result instead of single buffer.
    ** 012 SBI 20161101 Added tab item list as a parameter to the enable, view, display,
    **                  displayAndDown and promptFor methods provided by ClientExports.
    ** 013 CA  20180620 Ensure both on/off calls for an invalidation bracket are always called.
    ** 014 GBB 20230825 checkCallerAbort moved to SecurityUtil & calls updated.
    */
    /*
    ** 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 com.goldencode.p2j.ui.*;
    import com.goldencode.p2j.ui.chui.ThinClient;
    import com.goldencode.p2j.ui.client.*;
    import com.goldencode.p2j.util.*;
    import java.util.*;

    /**
     * Hard coded user interface which displays a prompt to obtain the login
     * credentials (userid and password). This is coded to work as a client-side
     * authentication plugin called from the security manager. While in operation,
     * the client environment and session are not fully initialized. This means
     * that processing must be limited.
     */
    public class DefaultLoginPanel
    implements Authenticator
    {
       /** Client interface. */
       private ThinClient client = null;

       /** Edit frame definition. */
       private ScreenDefinition editsd = null;

       /** Edit frame ID. */
       private static final int EDIT_FID = 100;

       /** User ID field ID. */
       private static final int USER_ID = EDIT_FID + 1;

       /** Password field ID. */
       private static final int PASSWORD_ID = USER_ID + 2; // 1 + skip

       /** Standard login status message. */
       private static final String STD_MSG = "Enter login credentials.";

       /** Invalid password status message. */
       private static final String INVALID_PASSWORD = "Invalid password!";

       /** Invalid user status message. */
       private static final String INVALID_USER = "Unknown user name!";

       /** The screen buffer for the editing frame. */
       private ScreenBuffer editsb = new ScreenBuffer(EDIT_FID, 3);

       /** The userid typed last time this was used. */
       private String lastid = null;

       /** The password typed last time this was used. */
       private String lastpw = null;

       /**
        * Default constructor.
        */
       public DefaultLoginPanel()
       {
          client = ThinClient.getInstance();
       }

       /**
        * Implements client side custom authentication logic.
        *
        * @param    parameters
        *           Additional configuration parameters. This plugin uses
        *           "option" parameter which is taken from the directory.
        * @param    code
        *           The result of the most recent attempt to authenticate or
        *           <code>AUTH_RESULT_NONE</code> if this is the first attempt.
        *
        * @return   Array of bytes to be transmitted to the server as the
        *           authorization input.
        */
       @Override
       public byte[] clientAuthHook(Map<String, Object> parameters, int code)
       {
          OutputManager<?> tk = OutputManager.instance();

          // there are two tab items
          int[] tabItemList = new int[] {USER_ID, PASSWORD_ID};

          // push the frame definition the first time in
          if (code == AUTH_RESULT_NONE)
          {
             // create the frame definition on the fly
             editsd = new ScreenDefinition(EDIT_FID);

             // edit frame configuration
             FrameConfig editfc = new FrameConfig();
             editfc.row = 10;
             editfc.box = true;
             editfc.centered = true;
             editfc.overlay = true;
             editfc.dcolor = Color.NORMAL;
             editfc.sideLabels = true;
             editsd.addConfig(editfc, EDIT_FID);

             FillInConfig fic;

             // user ID entry field
             fic = new FillInConfig();
             fic.dataType = "character";
             fic.format = "x(25)";
             fic.label = " User ID";
             editsd.addConfig(fic, USER_ID);

             // set next widget position
             addSkip(editsd, 0, USER_ID + 1);

             // password entry field
             fic = new FillInConfig();
             fic.dataType = "character";
             fic.format = "x(25)";
             fic.label = "Password";
             fic.blank = true;
             editsd.addConfig(fic, PASSWORD_ID);

             // instantiate screen data
             client.pushScreenDefinition(new ScreenDefinition[] {editsd});

             // set status line for input operation
             client.statusInput(STD_MSG, WindowConfig.RESOLVE_WINDOW);
          }
          else
          {
             String msgtxt = INVALID_PASSWORD;

             if (code == AUTH_RESULT_INVALID_USERID)
             {
                msgtxt = INVALID_USER;
             }

             // display error
             client.message(msgtxt);
          }

          // process the edit frame screen buffer
          if (lastid != null)
          {
             // on errors, we have to display the previously typed userid
             editsb.putWidgetValue(USER_ID, new character(lastid));
          }

          String id = null;
          String pw = null;

          EventList el = new EventList(true);
          ScreenBuffer[] sbf = null;

          Window<?> window = WindowManager.getDefaultWindow();

          while (true)
          {
             // drive the logon frame I/O
             tk.setInvalidate(true);
             try
             {
                client.enable(EDIT_FID, null, new ScreenBuffer[] {editsb}, true,
                              WindowConfig.RESOLVE_WINDOW, tabItemList);
                client.clear(EDIT_FID, true);
                client.view(EDIT_FID, new ScreenBuffer[] {editsb}, null, true,
                            WindowConfig.RESOLVE_WINDOW, tabItemList);
                editsb.resetChanged();
             }
             finally
             {
                tk.setInvalidate(window, false);
             }

             try
             {
                client.setAuthMode(true);
                sbf = client.waitFor(el, USER_ID, -1, new ScreenBuffer[] {editsb});
             }

             catch (ConditionException cx)
             {
                continue;
             }

             finally
             {
                client.setAuthMode(false);
             }

             tk.setInvalidate(true);
             try
             {
                client.enable(EDIT_FID, null, new ScreenBuffer[] {editsb}, false,
                              WindowConfig.RESOLVE_WINDOW, tabItemList);
             }
             finally
             {
                tk.setInvalidate(window, false);
             }

             // inspect the input
             int keyCode = sbf[0].getKeyCode();

             // exit out if requested
             if (Keyboard.keyFunction(keyCode).equals("END-ERROR"))
                return new byte[] {};

             character idc = (character) sbf[0].getWidgetValue(USER_ID);

             if (idc == null && lastid == null)
                continue;

             id = (idc != null) ? idc.getValue().trim() : lastid;
             lastid = id;

             character pwc = (character) sbf[0].getWidgetValue(PASSWORD_ID);

             if (pwc == null && lastpw == null)
             {
                pw = "";
             }
             else
             {
                pw = (pwc != null) ? pwc.getValue() : lastpw;
                lastpw = pw;
             }

             break;
          }

          // return a byte array
          return SecurityUtil.packageIdPassword(id, pw);
       }

       /**
        * Finalizes any resources allocated during authentication by the client.
        */
       @Override
       public void clientFinalize()
       {
          client.statusInputRevert(WindowConfig.RESOLVE_WINDOW);
          client.hideAll(true, WindowConfig.RESOLVE_WINDOW);
          client.destroyFrame(EDIT_FID);
       }

       /**
        * Not used for the client side.
        *
        * @param    auth
        *           The authorization input from the client.
        * @param    entity
        *           The entity to be authenticated.
        *
        * @return   Always <code>null</code>.
        */
       @Override
       public AuthenticationResponse serverAuthHook(byte[] auth, String entity)
       {
          return null;
       }

       /**
        * Not used for the client side, 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. Not used for the client side.
        *
        * @return  Always <code>null</code>.
        */
       @Override
       public Set<String> getAuthenticationEntities()
       {
          return null;
       }

       /**
        * Configures the Authenticator by setting the "option" parameter from directory.xml.
        * Not used for the client side.
        *
        * @param   option
        *          The value of "option" entry for the auth plugin.
        */
       @Override
       public void configure(String option)
       {
          // nop
       }

       /**
        * Add specified number of empty lines
        *
        * @param   sd
        *          The frame to which to add a skip.
        * @param   lines
        *          Lines to skip.
        * @param   id
        *          Widget ID to be used for this skip widget.
        */
       private void addSkip(ScreenDefinition sd, int lines, int id)
       {
          SkipConfig sc = new SkipConfig();
          sc.vertical = true;   // skip not space
          sc.length = lines;
          sd.addConfig(sc, id);
       }
    }