/*
 *  Nutzerverwaltung - User and role management in your browser
 *  Copyright (C) 2011-2016 Ulrich Hilger, http://uhilger.de
 *
 *  This program is free software: you can redistribute it and/or modify
 *  it under the terms of the GNU 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program.  If not, see http://www.gnu.org/licenses/
 */

package de.uhilger.um;

import java.security.NoSuchAlgorithmException;
import java.util.logging.Level;
import java.util.logging.Logger;
import org.apache.catalina.realm.MessageDigestCredentialHandler;

/**
 * Ein Digester für die Nutzerverwaltung, der die Klasse 
 * RealmBase von Tomcat zum Verschlüsseln nutzt
 *
 * @author Copyright (c) Ulrich Hilger, http://uhilger.de
 * @author Published under the terms and conditions of the
 * <a href="http://www.gnu.org/licenses/agpl-3.0" target="_blank">GNU Affero
 * General Public License</a>
 *
 * @version 2, December 27, 2016
 */
public class TomcatDigester implements Digester {

  @Override
  public String digest(String text, String algorithm, String encoding) {
    /*
    Die Methode RealmBase.Digest ist mit dem Hinweis 'unused' ab 
    Tomcat 9 entfernt worden. Das, obwohl die Tomcat-eigene Dokumentation
    diese Methode ausdruecklich nennt, vgl. "Digested Passwords"
    auf http://tomcat.apache.org/tomcat-10.0-doc/realm-howto.html
    
    Als Ersatz wird der MessageDigestCredentialHandler verwendet
    */
    //return RealmBase.Digest(text, algorithm, encoding);
    //return text;
    MessageDigestCredentialHandler mh = new MessageDigestCredentialHandler();
    try {
      mh.setAlgorithm(algorithm);
    } catch (NoSuchAlgorithmException ex) {
      Logger.getLogger(TomcatDigester.class.getName()).log(Level.SEVERE, null, ex);
    }
    mh.setEncoding(encoding);
    return mh.mutate(text);
  }

  @Override
  public boolean matches(String inputCredentials, String storedCredentials, String algorithm, String encoding) {
    MessageDigestCredentialHandler mh = new MessageDigestCredentialHandler();
    try {
      mh.setAlgorithm(algorithm);
    } catch (NoSuchAlgorithmException ex) {
      Logger.getLogger(TomcatDigester.class.getName()).log(Level.SEVERE, null, ex);
    }
    mh.setEncoding(encoding);
    return mh.matches(inputCredentials, storedCredentials);
  }
  
}