SCM-Manager/scm-webapp/src/main/java/sonia/scm/security/ScmRealm.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.security;

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

import com.google.common.collect.Lists;
import com.google.common.collect.Sets;
import com.google.inject.Inject;

import org.apache.shiro.authc.AccountException;
import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationInfo;
import org.apache.shiro.authc.AuthenticationToken;
import org.apache.shiro.authc.DisabledAccountException;
import org.apache.shiro.authc.SimpleAuthenticationInfo;
import org.apache.shiro.authc.UnknownAccountException;
import org.apache.shiro.authc.pam.UnsupportedTokenException;
import org.apache.shiro.authz.AuthorizationInfo;
import org.apache.shiro.authz.SimpleAuthorizationInfo;
import org.apache.shiro.realm.AuthorizingRealm;
import org.apache.shiro.subject.PrincipalCollection;
import org.apache.shiro.subject.SimplePrincipalCollection;

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

import sonia.scm.HandlerEvent;
import sonia.scm.cache.Cache;
import sonia.scm.cache.CacheManager;
import sonia.scm.config.ScmConfiguration;
import sonia.scm.group.Group;
import sonia.scm.group.GroupManager;
import sonia.scm.repository.Permission;
import sonia.scm.repository.Repository;
import sonia.scm.repository.RepositoryDAO;
import sonia.scm.repository.RepositoryListener;
import sonia.scm.repository.RepositoryManager;
import sonia.scm.user.User;
import sonia.scm.user.UserException;
import sonia.scm.user.UserListener;
import sonia.scm.user.UserManager;
import sonia.scm.util.Util;
import sonia.scm.web.security.AuthenticationManager;
import sonia.scm.web.security.AuthenticationResult;
import sonia.scm.web.security.AuthenticationState;

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

import java.io.IOException;

import java.util.Collection;
import java.util.Iterator;
import java.util.List;
import java.util.Set;

import javax.servlet.http.HttpServletRequest;

/**
 *
 * @author Sebastian Sdorra
 */
public class ScmRealm extends AuthorizingRealm
  implements RepositoryListener, UserListener
{

  /** Field description */
  private static final String CACHE_NAME = "sonia.cache.authorizing";

  /** Field description */
  private static final String NAME = "scm";

  /** Field description */
  private static final String ROLE_ADMIN = "admin";

  /** Field description */
  private static final String ROLE_USER = "user";

  /** Field description */
  private static final String SCM_CREDENTIALS = "SCM_CREDENTIALS";

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

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

  /**
   * Constructs ...
   *
   *
   *
   * @param configuration
   * @param cacheManager
   * @param userManager
   * @param groupManager
   * @param repositoryManager
   * @param repositoryDAO
   * @param authenticator
   */
  @Inject
  public ScmRealm(ScmConfiguration configuration, CacheManager cacheManager,
    UserManager userManager, GroupManager groupManager,
    RepositoryManager repositoryManager, RepositoryDAO repositoryDAO,
    AuthenticationManager authenticator)
  {
    this.configuration = configuration;
    this.userManager = userManager;
    this.groupManager = groupManager;
    this.repositoryDAO = repositoryDAO;
    this.authenticator = authenticator;
    this.cache = cacheManager.getCache(String.class, AuthorizationInfo.class,
      CACHE_NAME);
    setPermissionResolver(new RepositoryPermissionResolver());
    userManager.addListener(this);
    repositoryManager.addListener(this);
  }

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

  /**
   * Method description
   *
   *
   * @param repository
   * @param event
   */
  @Override
  public void onEvent(Repository repository, HandlerEvent event)
  {
    if (logger.isDebugEnabled())
    {
      logger.debug("clear cache, because repository {} has changed",
        repository.getName());
    }

    cache.clear();
  }

  /**
   * Method description
   *
   *
   * @param user
   * @param event
   */
  @Override
  public void onEvent(User user, HandlerEvent event)
  {
    if (logger.isDebugEnabled())
    {
      logger.debug(
        "clear cache of user {}, because user properties have changed",
        user.getName());
    }

    cache.remove(user.getId());
  }

  /**
   * Method description
   *
   *
   * @param token
   *
   * @return
   */
  @Override
  public boolean supports(AuthenticationToken token)
  {
    return token instanceof ScmAuthenticationToken;
  }

  /**
   * Method description
   *
   *
   * @param token
   *
   * @param authToken
   *
   * @return
   *
   * @throws AuthenticationException
   */
  @Override
  protected AuthenticationInfo doGetAuthenticationInfo(
    AuthenticationToken authToken)
    throws AuthenticationException
  {
    if (!(authToken instanceof ScmAuthenticationToken))
    {
      throw new UnsupportedTokenException("ScmAuthenticationToken is required");
    }

    ScmAuthenticationToken token = (ScmAuthenticationToken) authToken;

    AuthenticationInfo info = null;
    AuthenticationResult result =
      authenticator.authenticate(token.getRequest(), token.getResponse(),
        token.getUsername(), token.getPassword());

    if (result.getState() == AuthenticationState.SUCCESS)
    {
      info = createAuthenticationInfo(token, result);
    }
    else if (result.getState() == AuthenticationState.NOT_FOUND)
    {
      throw new UnknownAccountException(
        "unknown account ".concat(token.getUsername()));
    }
    else
    {
      throw new AccountException("authentication failed");
    }

    return info;
  }

  /**
   * Method description
   *
   *
   * @param principals
   *
   * @return
   */
  @Override
  protected AuthorizationInfo doGetAuthorizationInfo(
    PrincipalCollection principals)
  {
    User user = principals.oneByType(User.class);

    AuthorizationInfo info = cache.get(user.getName());

    if (info == null)
    {
      if (logger.isTraceEnabled())
      {
        logger.trace("coullect AuthorizationInfo for user {}", user.getName());
      }

      Groups groups = principals.oneByType(Groups.class);

      info = createAuthorizationInfo(user, groups);
    }
    else if (logger.isDebugEnabled())
    {
      logger.debug("retrieve AuthorizationInfo for user {} from cache",
        user.getName());
    }

    return info;
  }

  /**
   * Method description
   *
   *
   * @param request
   * @param password
   * @param ar
   *
   * @return
   */
  private Set<String> authenticate(HttpServletRequest request, String password,
    AuthenticationResult ar)
  {
    Set<String> groupSet = null;
    User user = ar.getUser();

    try
    {
      groupSet = createGroupSet(ar);

      // check for admin user
      checkForAuthenticatedAdmin(user, groupSet);

      // store user
      User dbUser = userManager.get(user.getName());

      if (dbUser != null)
      {
        checkDBForAdmin(user, dbUser);
        checkDBForActive(user, dbUser);
      }

      // create new user
      else
      {
        userManager.create(user);
      }

      if (user.isActive())
      {

        if (logger.isDebugEnabled())
        {
          logGroups(user, groupSet);
        }

        // store encrypted credentials in session
        String credentials = user.getName();

        if (Util.isNotEmpty(password))
        {
          credentials = credentials.concat(":").concat(password);
        }

        credentials = CipherUtil.getInstance().encode(credentials);
        request.getSession(true).setAttribute(SCM_CREDENTIALS, credentials);
      }
      else
      {

        String msg = "user ".concat(user.getName()).concat(" is deactivated");

        if (logger.isWarnEnabled())
        {
          logger.warn(msg);
        }

        throw new DisabledAccountException(msg);

      }
    }
    catch (Exception ex)
    {
      logger.error("authentication failed", ex);

      throw new AuthenticationException("authentication failed", ex);
    }

    return groupSet;
  }

  /**
   * Method description
   *
   *
   * @param user
   * @param dbUser
   */
  private void checkDBForActive(User user, User dbUser)
  {

    // user is deactivated by database
    if (!dbUser.isActive())
    {
      if (logger.isDebugEnabled())
      {
        logger.debug("user {} is marked as deactivated by local database",
          user.getName());
      }

      user.setActive(false);
    }
  }

  /**
   * Method description
   *
   *
   * @param user
   * @param dbUser
   *
   * @throws IOException
   * @throws UserException
   */
  private void checkDBForAdmin(User user, User dbUser)
    throws UserException, IOException
  {

    // if database user is an admin, set admin for the current user
    if (dbUser.isAdmin())
    {
      if (logger.isDebugEnabled())
      {
        logger.debug("user {} of type {} is marked as admin by local database",
          user.getName(), user.getType());
      }

      user.setAdmin(true);
    }

    // modify existing user, copy properties except password and admin
    if (user.copyProperties(dbUser, false))
    {
      userManager.modify(dbUser);
    }
  }

  /**
   * Method description
   *
   *
   * @param user
   * @param groupSet
   */
  private void checkForAuthenticatedAdmin(User user, Set<String> groupSet)
  {
    if (!user.isAdmin())
    {
      user.setAdmin(isAdmin(user, groupSet));

      if (logger.isDebugEnabled() && user.isAdmin())
      {
        logger.debug("user {} is marked as admin by configuration",
          user.getName());
      }
    }
    else if (logger.isDebugEnabled())
    {
      logger.debug("authenticator {} marked user {} as admin", user.getType(),
        user.getName());
    }
  }

  /**
   * Method description
   *
   *
   * @param user
   * @param groups
   *
   * @return
   */
  private List<org.apache.shiro.authz.Permission> collectRepositoryPermissions(
    User user, Collection<String> groups)
  {
    List<org.apache.shiro.authz.Permission> permissions = Lists.newArrayList();

    for (Repository repository : repositoryDAO.getAll())
    {
      List<Permission> repositoryPermissions = repository.getPermissions();

      for (Permission permission : repositoryPermissions)
      {
        if ((permission.isGroupPermission()
          && groups.contains(
            permission.getName())) || ((!permission.isGroupPermission())
              && user.getName().equals(permission.getName())))
        {
          RepositoryPermission rp =
            new RepositoryPermission(repository.getId(), permission.getType());

          if (logger.isTraceEnabled())
          {
            logger.trace("add repository permission {} for user {}", rp,
              user.getName());
          }

          permissions.add(rp);
        }
      }
    }

    return permissions;
  }

  /**
   * Method description
   *
   *
   * @param token
   * @param result
   *
   * @return
   */
  private AuthenticationInfo createAuthenticationInfo(
    ScmAuthenticationToken token, AuthenticationResult result)
  {
    User user = result.getUser();
    Collection<String> groups = authenticate(token.getRequest(),
                                  token.getPassword(), result);

    SimplePrincipalCollection collection = new SimplePrincipalCollection();

    collection.add(user, NAME);
    collection.add(groups, NAME);

    return new SimpleAuthenticationInfo(collection, token.getPassword());
  }

  /**
   * Method description
   *
   *
   * @param user
   * @param groups
   *
   * @return
   */
  private AuthorizationInfo createAuthorizationInfo(User user, Groups groups)
  {
    Set<String> roles = Sets.newHashSet();

    roles.add(ROLE_USER);

    if (user.isAdmin())
    {
      if (logger.isDebugEnabled())
      {
        logger.debug("grant admin role for user {}", user.getName());
      }

      roles.add(ROLE_ADMIN);
    }

    SimpleAuthorizationInfo info = new SimpleAuthorizationInfo(roles);

    info.addObjectPermissions(collectRepositoryPermissions(user,
      groups.getGroups()));

    return info;
  }

  /**
   * Method description
   *
   *
   * @param ar
   *
   * @return
   */
  private Set<String> createGroupSet(AuthenticationResult ar)
  {
    Set<String> groupSet = Sets.newHashSet();

    // load external groups
    Collection<String> extGroups = ar.getGroups();

    if (extGroups != null)
    {
      groupSet.addAll(extGroups);
    }

    // load internal groups
    loadGroups(ar.getUser(), groupSet);

    return groupSet;
  }

  /**
   * Method description
   *
   *
   *
   * @param user
   * @param groupSet
   */
  private void loadGroups(User user, Set<String> groupSet)
  {
    Collection<Group> groupCollection =
      groupManager.getGroupsForMember(user.getName());

    if (groupCollection != null)
    {
      for (Group group : groupCollection)
      {
        groupSet.add(group.getName());
      }
    }
  }

  /**
   * Method description
   *
   *
   * @param user
   * @param groups
   */
  private void logGroups(User user, Set<String> groups)
  {
    StringBuilder msg = new StringBuilder("user ");

    msg.append(user.getName());

    if (Util.isNotEmpty(groups))
    {
      msg.append(" is member of ");

      Iterator<String> groupIt = groups.iterator();

      while (groupIt.hasNext())
      {
        msg.append(groupIt.next());

        if (groupIt.hasNext())
        {
          msg.append(", ");
        }
      }
    }
    else
    {
      msg.append(" is not a member of a group");
    }

    logger.debug(msg.toString());
  }

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

  /**
   * Method description
   *
   *
   *
   *
   * @param user
   * @param groups
   * @return
   */
  private boolean isAdmin(User user, Collection<String> groups)
  {
    boolean result = false;
    Set<String> adminUsers = configuration.getAdminUsers();

    if (adminUsers != null)
    {
      result = adminUsers.contains(user.getName());
    }

    if (!result)
    {
      Set<String> adminGroups = configuration.getAdminGroups();

      if (adminGroups != null)
      {
        result = Util.containsOne(adminGroups, groups);
      }
    }

    return result;
  }

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

  /** Field description */
  private AuthenticationManager authenticator;

  /** Field description */
  private Cache<String, AuthorizationInfo> cache;

  /** Field description */
  private ScmConfiguration configuration;

  /** Field description */
  private GroupManager groupManager;

  /** Field description */
  private RepositoryDAO repositoryDAO;

  /** Field description */
  private UserManager userManager;
}