/*
    * DavMail POP/IMAP/SMTP/CalDav/LDAP Exchange Gateway
    * Copyright (C) 2010  Mickael Guessant
    *
    * 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 2
    * 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, write to the Free Software
   * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.
   */
  
  package davmail.http;
  
  import jcifs.ntlmssp.NtlmFlags;
  import jcifs.ntlmssp.Type1Message;
  import jcifs.ntlmssp.Type2Message;
  import jcifs.ntlmssp.Type3Message;
  import jcifs.util.Base64;
  import org.apache.http.impl.auth.NTLMEngine;
  import org.apache.http.impl.auth.NTLMEngineException;
  import org.apache.log4j.Logger;
  
  import java.io.IOException;
  
  /**
   * JCIFS based NTLM authentication.
   */
  public final class JCIFSEngine implements NTLMEngine {
      static final Logger LOGGER = Logger.getLogger("davmail.http.JCIFSEngine");
  
      private static final int TYPE_1_FLAGS =
              NtlmFlags.NTLMSSP_NEGOTIATE_NTLM2 | NtlmFlags.NTLMSSP_NEGOTIATE_ALWAYS_SIGN |
                      NtlmFlags.NTLMSSP_NEGOTIATE_OEM_WORKSTATION_SUPPLIED | NtlmFlags.NTLMSSP_NEGOTIATE_OEM_DOMAIN_SUPPLIED |
                      NtlmFlags.NTLMSSP_NEGOTIATE_NTLM | NtlmFlags.NTLMSSP_REQUEST_TARGET |
                      NtlmFlags.NTLMSSP_NEGOTIATE_OEM | NtlmFlags.NTLMSSP_NEGOTIATE_UNICODE |
                      NtlmFlags.NTLMSSP_NEGOTIATE_56 | NtlmFlags.NTLMSSP_NEGOTIATE_128;
  
      public String generateType1Msg(final String domain, final String workstation) {
          final Type1Message type1Message = new Type1Message(TYPE_1_FLAGS, domain, workstation);
          LOGGER.debug("Generate Type1Msg "+type1Message);
          String encodedType1Message = Base64.encode(type1Message.toByteArray());
          if (LOGGER.isDebugEnabled()) {
              LOGGER.debug(NTLMMessageDecoder.decode(encodedType1Message));
          }
          return encodedType1Message;
      }
  
      public String generateType3Msg(final String username, final String password,
                                     final String domain, final String workstation, final String challenge)
              throws NTLMEngineException {
          if (LOGGER.isDebugEnabled()) {
              LOGGER.debug(NTLMMessageDecoder.decode(challenge));
          }
  
          Type2Message type2Message;
          try {
              type2Message = new Type2Message(Base64.decode(challenge));
          } catch (final IOException exception) {
              throw new NTLMEngineException("Invalid NTLM type 2 message", exception);
          }
          LOGGER.debug("Received Type2Msg " + type2Message);
  
          // from HttpClient 4 doc
          // final int type3Flags = type2Message.getFlags()
          //        & (0xffffffff ^ (NtlmFlags.NTLMSSP_TARGET_TYPE_DOMAIN | NtlmFlags.NTLMSSP_TARGET_TYPE_SERVER));
          int type3Flags = NtlmFlags.NTLMSSP_NEGOTIATE_NTLM2 | NtlmFlags.NTLMSSP_NEGOTIATE_ALWAYS_SIGN |
                  NtlmFlags.NTLMSSP_NEGOTIATE_NTLM | NtlmFlags.NTLMSSP_NEGOTIATE_UNICODE;
          Type3Message type3Message = new Type3Message(type2Message, password,
                  domain, username, workstation, type3Flags);
          LOGGER.debug("Generate Type3Msg "+type3Message);
          String encodedType3Message = Base64.encode(type3Message.toByteArray());
          if (LOGGER.isDebugEnabled()) {
              LOGGER.debug(NTLMMessageDecoder.decode(encodedType3Message));
          }
          return encodedType3Message;
      }
  
  }