package gnu.crypto.sasl.srp;

// ----------------------------------------------------------------------------
// $Id: SRPAuthInfoProvider.java,v 1.3 2005/10/06 04:24:18 rsdio Exp $
//
// Copyright (C) 2003 Free Software Foundation, Inc.
//
// This file is part of GNU Crypto.
//
// GNU Crypto 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 2, or (at your option)
// any later version.
//
// GNU Crypto 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; see the file COPYING.  If not, write to the
//
//    Free Software Foundation Inc.,
//    51 Franklin Street, Fifth Floor,
//    Boston, MA 02110-1301
//    USA
//
// Linking this library statically or dynamically with other modules is
// making a combined work based on this library.  Thus, the terms and
// conditions of the GNU General Public License cover the whole
// combination.
//
// As a special exception, the copyright holders of this library give
// you permission to link this library with independent modules to
// produce an executable, regardless of the license terms of these
// independent modules, and to copy and distribute the resulting
// executable under terms of your choice, provided that you also meet,
// for each linked independent module, the terms and conditions of the
// license of that module.  An independent module is a module which is
// not derived from or based on this library.  If you modify this
// library, you may extend this exception to your version of the
// library, but you are not obligated to do so.  If you do not wish to
// do so, delete this exception statement from your version.
// ----------------------------------------------------------------------------

import gnu.crypto.Registry;
import gnu.crypto.sasl.IAuthInfoProvider;
import gnu.crypto.sasl.NoSuchUserException;
import gnu.crypto.util.Util;

import java.io.IOException;
import java.util.HashMap;
import java.util.Map;

import javax.security.sasl.AuthenticationException;

/**
 * <p>The SRP mechanism authentication information provider implementation.</p>
 *
 * @version $Revision: 1.3 $
 */
public class SRPAuthInfoProvider implements IAuthInfoProvider {

   // Constants and variables
   // -------------------------------------------------------------------------

   private PasswordFile passwordFile = null;

   // Constructor(s)
   // -------------------------------------------------------------------------

   // implicit 0-args constrcutor

   // Class methods
   // -------------------------------------------------------------------------

   // Instance methods
   // -------------------------------------------------------------------------

   // IAuthInfoProvider interface implementation ------------------------------

   public void activate(Map context) throws AuthenticationException {
      try {
         if (context == null) {
            passwordFile = new PasswordFile();
         } else {
            passwordFile = (PasswordFile) context.get(SRPRegistry.PASSWORD_DB);
            if (passwordFile == null) {
               String pfn = (String) context.get(SRPRegistry.PASSWORD_FILE);
               if (pfn == null) {
                  passwordFile = new PasswordFile();
               } else {
                  passwordFile = new PasswordFile(pfn);
               }
            }
         }
      } catch (IOException x) {
         throw new AuthenticationException("activate()", x);
      }
   }

	public void passivate() throws AuthenticationException {
      passwordFile = null;
   }

	public boolean contains(String userName) throws AuthenticationException {
      if (passwordFile == null) {
         throw new AuthenticationException("contains()", new IllegalStateException());
      }
      boolean result = false;
      try {
         result = passwordFile.contains(userName);
      } catch (IOException x) {
         throw new AuthenticationException("contains()", x);
      }
      return result;
   }

	public Map lookup(Map userID) throws AuthenticationException {
      if (passwordFile == null) {
         throw new AuthenticationException("lookup()", new IllegalStateException());
      }
      Map result = new HashMap();
      try {
         String userName = (String) userID.get(Registry.SASL_USERNAME);
         if (userName == null) {
            throw new NoSuchUserException("");
         }
         String mdName = (String) userID.get(SRPRegistry.MD_NAME_FIELD);

         String[] data = passwordFile.lookup(userName, mdName);
         result.put(SRPRegistry.USER_VERIFIER_FIELD, data[0]);
         result.put(SRPRegistry.SALT_FIELD, data[1]);
         result.put(SRPRegistry.CONFIG_NDX_FIELD, data[2]);
      } catch (Exception x) {
         if (x instanceof AuthenticationException) {
            throw (AuthenticationException) x;
         }
         throw new AuthenticationException("lookup()", x);
      }
      return result;
   }

	public void update(Map userCredentials) throws AuthenticationException {
      if (passwordFile == null)
         throw new AuthenticationException("update()", new IllegalStateException());

      try {
         String userName = (String) userCredentials.get(Registry.SASL_USERNAME);
         String password = (String) userCredentials.get(Registry.SASL_PASSWORD);
         String salt =     (String) userCredentials.get(SRPRegistry.SALT_FIELD);
         String config =   (String) userCredentials.get(SRPRegistry.CONFIG_NDX_FIELD);
         if (salt == null || config == null) {
            passwordFile.changePasswd(userName, password);
         } else {
            passwordFile.add(userName, password, Util.fromBase64(salt), config);
         }
      } catch (Exception x) {
         if (x instanceof AuthenticationException) {
            throw (AuthenticationException) x;
         }
         throw new AuthenticationException("update()", x);
      }
   }

	public Map getConfiguration(String mode) throws AuthenticationException {
      if (passwordFile == null) {
         throw new AuthenticationException("getConfiguration()", new IllegalStateException());
      }
      Map result = new HashMap();
      try {
         String[] data = passwordFile.lookupConfig(mode);
         result.put(SRPRegistry.SHARED_MODULUS, data[0]);
         result.put(SRPRegistry.FIELD_GENERATOR, data[1]);
      } catch (Exception x) {
         if (x instanceof AuthenticationException) {
            throw (AuthenticationException) x;
         }
         throw new AuthenticationException("getConfiguration()", x);
      }
      return result;
   }
}
