package org.apache.maven.scm.provider.git.jgit.command;
   
   /*
    * Licensed to the Apache Software Foundation (ASF) under one
    * or more contributor license agreements.  See the NOTICE file
    * distributed with this work for additional information
    * regarding copyright ownership.  The ASF licenses this file
    * to you under the Apache License, Version 2.0 (the
    * "License"); you may not use this file except in compliance
   * with the License.  You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
   * KIND, either express or implied.  See the License for the
   * specific language governing permissions and limitations
   * under the License.
   */
  
  import com.jcraft.jsch.JSch;
  import com.jcraft.jsch.JSchException;
  import com.jcraft.jsch.Session;
  import org.apache.maven.scm.log.ScmLogger;
  import org.apache.maven.scm.provider.git.repository.GitScmProviderRepository;
  import org.eclipse.jgit.api.TransportConfigCallback;
  import org.eclipse.jgit.transport.JschConfigSessionFactory;
  import org.eclipse.jgit.transport.OpenSshConfig;
  import org.eclipse.jgit.transport.SshSessionFactory;
  import org.eclipse.jgit.transport.SshTransport;
  import org.eclipse.jgit.transport.Transport;
  import org.eclipse.jgit.util.FS;
  import org.eclipse.jgit.util.StringUtils;
  
  /**
   * Implementation of {@link TransportConfigCallback} which adds
   * a public/private key identity to ssh URLs if configured.
   */
  public class JGitTransportConfigCallback implements TransportConfigCallback
  {
      private SshSessionFactory sshSessionFactory = null;
  
      public JGitTransportConfigCallback( GitScmProviderRepository repo, ScmLogger logger )
      {
          if ( repo.getFetchInfo().getProtocol().equals( "ssh" ) )
          {
              if ( !StringUtils.isEmptyOrNull( repo.getPrivateKey() ) && repo.getPassphrase() == null )
              {
                  logger.debug( "using private key: " + repo.getPrivateKey() );
                  sshSessionFactory = new UnprotectedPrivateKeySessionFactory( repo );
              }
              else if ( !StringUtils.isEmptyOrNull( repo.getPrivateKey() ) && repo.getPassphrase() != null )
              {
                  logger.debug( "using private key with passphrase: " + repo.getPrivateKey() );
                  sshSessionFactory = new ProtectedPrivateKeyFileSessionFactory( repo );
              }
              else
              {
                  sshSessionFactory = new SimpleSessionFactory();
              }
          }
      }
  
      @Override
      public void configure( Transport transport )
      {
          if ( transport instanceof SshTransport )
          {
              SshTransport sshTransport = (SshTransport) transport;
              sshTransport.setSshSessionFactory( sshSessionFactory );
          }
      }
  
      private static class SimpleSessionFactory extends JschConfigSessionFactory
      {
          @Override
          protected void configure( OpenSshConfig.Host host, Session session )
          {
          }
      }
  
      private abstract static class PrivateKeySessionFactory extends SimpleSessionFactory
      {
          private final GitScmProviderRepository repo;
  
          GitScmProviderRepository getRepo()
          {
              return repo;
          }
  
          PrivateKeySessionFactory( GitScmProviderRepository repo )
          {
              this.repo = repo;
          }
      }
  
      private static class UnprotectedPrivateKeySessionFactory extends PrivateKeySessionFactory
      {
 
         UnprotectedPrivateKeySessionFactory( GitScmProviderRepository repo )
         {
             super( repo );
         }
 
         @Override
         protected JSch createDefaultJSch( FS fs ) throws JSchException
         {
             JSch defaultJSch = super.createDefaultJSch( fs );
             defaultJSch.addIdentity( getRepo().getPrivateKey() );
             return defaultJSch;
         }
     }
 
     private static class ProtectedPrivateKeyFileSessionFactory extends PrivateKeySessionFactory
     {
 
         ProtectedPrivateKeyFileSessionFactory( GitScmProviderRepository repo )
         {
             super( repo );
         }
 
         @Override
         protected JSch createDefaultJSch( FS fs ) throws JSchException
         {
             JSch defaultJSch = super.createDefaultJSch( fs );
             defaultJSch.addIdentity( getRepo().getPrivateKey(), getRepo().getPassphrase() );
             return defaultJSch;
         }
     }
 }