SCM-Manager/scm-plugins/scm-hg-plugin/src/main/java/sonia/scm/web/HgHookCallbackServlet.java

/**
 * Copyright (c) 2010, Sebastian Sdorra
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. Neither the name of SCM-Manager; nor the names of its
 *    contributors may be used to endorse or promote products derived from this
 *    software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * http://bitbucket.org/sdorra/scm-manager
 *
 */



package sonia.scm.web;

//~--- non-JDK imports --------------------------------------------------------

import com.google.inject.Inject;
import com.google.inject.Provider;
import com.google.inject.Singleton;

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import sonia.scm.repository.HgContext;
import sonia.scm.repository.HgHookManager;
import sonia.scm.repository.HgRepositoryHandler;
import sonia.scm.repository.HgRepositoryHookEvent;
import sonia.scm.repository.RepositoryHookType;
import sonia.scm.repository.RepositoryManager;
import sonia.scm.repository.RepositoryNotFoundException;
import sonia.scm.security.CipherUtil;
import sonia.scm.util.HttpUtil;
import sonia.scm.util.IOUtil;
import sonia.scm.util.Util;
import sonia.scm.web.security.WebSecurityContext;

//~--- JDK imports ------------------------------------------------------------

import java.io.IOException;

import java.util.regex.Matcher;
import java.util.regex.Pattern;

import javax.servlet.ServletException;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;

/**
 *
 * @author Sebastian Sdorra
 */
@Singleton
public class HgHookCallbackServlet extends HttpServlet
{

  /** Field description */
  public static final String HGHOOK_POST_RECEIVE = "changegroup";

  /** Field description */
  public static final String HGHOOK_PRE_RECEIVE = "pretxnchangegroup";

  /** Field description */
  public static final String PARAM_REPOSITORYPATH = "repositoryPath";

  /** Field description */
  private static final String PARAM_CHALLENGE = "challenge";

  /** Field description */
  private static final String PARAM_CREDENTIALS = "credentials";

  /** Field description */
  private static final String PARAM_NODE = "node";

  /** Field description */
  private static final Pattern REGEX_URL =
    Pattern.compile("^/hook/hg/([^/]+)$");

  /** the logger for HgHookCallbackServlet */
  private static final Logger logger =
    LoggerFactory.getLogger(HgHookCallbackServlet.class);

  //~--- constructors ---------------------------------------------------------

  /**
   * Constructs ...
   *
   *
   * @param repositoryManager
   * @param handler
   * @param hookManager
   * @param contextProvider
   * @param securityContextProvider
   */
  @Inject
  public HgHookCallbackServlet(
          RepositoryManager repositoryManager, HgRepositoryHandler handler,
          HgHookManager hookManager, Provider<HgContext> contextProvider,
          Provider<WebSecurityContext> securityContextProvider)
  {
    this.repositoryManager = repositoryManager;
    this.handler = handler;
    this.hookManager = hookManager;
    this.contextProvider = contextProvider;
    this.securityContextProvider = securityContextProvider;
  }

  //~--- methods --------------------------------------------------------------

  /**
   * Method description
   *
   *
   * @param request
   * @param response
   *
   * @throws IOException
   * @throws ServletException
   */
  @Override
  protected void doPost(HttpServletRequest request,
                        HttpServletResponse response)
          throws ServletException, IOException
  {
    String strippedURI = HttpUtil.getStrippedURI(request);
    Matcher m = REGEX_URL.matcher(strippedURI);

    if (m.matches())
    {
      String repositoryId = getRepositoryName(request);
      String type = m.group(1);
      String challenge = request.getParameter(PARAM_CHALLENGE);

      if (Util.isNotEmpty(challenge))
      {
        String node = request.getParameter(PARAM_NODE);

        if (Util.isNotEmpty(node))
        {
          String credentials = request.getParameter(PARAM_CREDENTIALS);

          if (Util.isNotEmpty(credentials))
          {
            authenticate(request, response, credentials);
          }

          hookCallback(response, repositoryId, type, challenge, node);
        }
        else if (logger.isDebugEnabled())
        {
          logger.debug("node parameter not found");
        }
      }
      else if (logger.isDebugEnabled())
      {
        logger.debug("challenge parameter not found");
      }
    }
    else
    {
      if (logger.isDebugEnabled())
      {
        logger.debug("url does not match");
      }

      response.sendError(HttpServletResponse.SC_BAD_REQUEST);
    }
  }

  /**
   * Method description
   *
   *
   * @param request
   * @param response
   * @param credentials
   */
  private void authenticate(HttpServletRequest request,
                            HttpServletResponse response, String credentials)
  {
    try
    {
      credentials = CipherUtil.getInstance().decode(credentials);

      if (Util.isNotEmpty(credentials))
      {
        String[] credentialsArray = credentials.split(":");

        if (credentialsArray.length >= 2)
        {
          WebSecurityContext context = securityContextProvider.get();

          context.authenticate(request, response, credentialsArray[0],
                               credentialsArray[1]);
        }
      }
    }
    catch (Exception ex)
    {
      logger.error("could not authenticate user", ex);
    }
  }

  /**
   * Method description
   *
   *
   * @param response
   * @param repositoryName
   * @param node
   * @param type
   *
   * @throws IOException
   */
  private void fireHook(HttpServletResponse response, String repositoryName,
                        String node, RepositoryHookType type)
          throws IOException
  {
    try
    {
      if (type == RepositoryHookType.PRE_RECEIVE)
      {
        contextProvider.get().setPending(true);
      }

      repositoryManager.fireHookEvent(HgRepositoryHandler.TYPE_NAME,
                                      repositoryName,
                                      new HgRepositoryHookEvent(handler,
                                        repositoryName, node, type));
    }
    catch (RepositoryNotFoundException ex)
    {
      if (logger.isErrorEnabled())
      {
        logger.error("could not find repository {}", repositoryName);

        if (logger.isTraceEnabled())
        {
          logger.trace("repository not found", ex);
        }
      }

      response.sendError(HttpServletResponse.SC_NOT_FOUND);
    }
  }

  /**
   * Method description
   *
   *
   * @param response
   * @param repositoryName
   * @param typeName
   * @param challenge
   * @param node
   *
   * @throws IOException
   */
  private void hookCallback(HttpServletResponse response,
                            String repositoryName, String typeName,
                            String challenge, String node)
          throws IOException
  {
    if (hookManager.isAcceptAble(challenge))
    {
      RepositoryHookType type = null;

      if (HGHOOK_PRE_RECEIVE.equals(typeName))
      {
        type = RepositoryHookType.PRE_RECEIVE;
      }
      else if (HGHOOK_POST_RECEIVE.equals(typeName))
      {
        type = RepositoryHookType.POST_RECEIVE;
      }

      if (type != null)
      {
        fireHook(response, repositoryName, node, type);
      }
      else
      {
        if (logger.isWarnEnabled())
        {
          logger.warn("unknown hook type {}", typeName);
        }

        response.sendError(HttpServletResponse.SC_BAD_REQUEST);
      }
    }
    else
    {
      if (logger.isWarnEnabled())
      {
        logger.warn("hg hook challenge is not accept able");
      }

      response.sendError(HttpServletResponse.SC_BAD_REQUEST);
    }
  }

  //~--- get methods ----------------------------------------------------------

  /**
   * Method description
   *
   *
   * @param request
   *
   * @return
   */
  private String getRepositoryName(HttpServletRequest request)
  {
    String name = null;
    String path = request.getParameter(PARAM_REPOSITORYPATH);

    if (Util.isNotEmpty(path))
    {
      int directoryLength =
        handler.getConfig().getRepositoryDirectory().getAbsolutePath().length();

      if (directoryLength < path.length())
      {
        name = IOUtil.trimSeperatorChars(path.substring(directoryLength));
      }
      else if (logger.isWarnEnabled())
      {
        logger.warn("path is shorter as the main hg repository path");
      }
    }
    else if (logger.isWarnEnabled())
    {
      logger.warn("no repository path parameter found");
    }

    return name;
  }

  //~--- fields ---------------------------------------------------------------

  /** Field description */
  private Provider<HgContext> contextProvider;

  /** Field description */
  private HgRepositoryHandler handler;

  /** Field description */
  private HgHookManager hookManager;

  /** Field description */
  private RepositoryManager repositoryManager;

  /** Field description */
  private Provider<WebSecurityContext> securityContextProvider;
}