content: /*
   * The Alluxio Open Foundation licenses this work under the Apache License, version 2.0
   * (the "License"). You may not use this work except in compliance with the License, which is
   * available at www.apache.org/licenses/LICENSE-2.0
   *
   * This software is distributed on an "AS IS" basis, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied, as more fully set forth in the License.
   *
   * See the NOTICE file distributed with this work for information regarding copyright ownership.
   */
  
  package alluxio.security.user;
  
  import alluxio.annotation.SuppressFBWarnings;
  import alluxio.conf.AlluxioConfiguration;
  import alluxio.conf.PropertyKey;
  import alluxio.exception.status.UnauthenticatedException;
  import alluxio.security.User;
  import alluxio.security.authentication.AuthType;
  import alluxio.util.CommonUtils;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.ArrayList;
  import java.util.Arrays;
  import java.util.stream.Collectors;
  import javax.security.auth.Subject;
  
  /**
   * UserState handles logging in any client, and maintains the state. The UserState provides access
   * to the {@link Subject} and the {@link User} for the client.
   */
  public interface UserState {
    /**
     * An ordered list of factories for creating UserState instances. The UserState factories are
     * tried in order, from first to last.
     */
    @SuppressFBWarnings(value = "MS_OOI_PKGPROTECT")
    ArrayList<UserStateFactory> FACTORIES = new ArrayList<>(Arrays.asList(
        new SimpleUserState.Factory(),
        new NoopUserState.Factory()
    ));
  
    /**
     * Returns the Subject for this user. Attempts to log in if not already logged in.
     *
     * @return the {@link Subject} for this user state
     */
    Subject getSubject();
  
    /**
     * Returns the User object for this user. Attempts to log in if not already logged in.
     *
     * @return the {@link User} for this user state
     * @throws UnauthenticatedException if the attempted login failed
     */
    User getUser() throws UnauthenticatedException;
  
    /**
     * Attempts to log in again, and returns the new User.
     *
     * @return the {@link User} for this user state, after the relogin
     * @throws UnauthenticatedException if the re-login failed
     */
    User relogin() throws UnauthenticatedException;
  
    /**
     * A factory for creating a UserState.
     */
    class Factory {
      private static final Logger LOG = LoggerFactory.getLogger(Factory.class);
  
      /**
       * @param conf the configuration to use
       * @return a new UserState instance
       */
      public static UserState create(AlluxioConfiguration conf) {
        return create(conf, new Subject());
      }
  
      /**
       * @param conf the configuration to use
       * @param subject the subject to use for the UserState
       * @return a new UserState instance
       */
      public static UserState create(AlluxioConfiguration conf, Subject subject) {
        return create(conf, subject, CommonUtils.PROCESS_TYPE.get());
      }
  
      /**
       * @param conf the configuration to use
       * @param subject the subject to use for the UserState
       * @param processType the process type to create the UserState for
       * @return a new UserState instance
       */
      public static UserState create(AlluxioConfiguration conf, Subject subject,
          CommonUtils.ProcessType processType) {
        AuthType authType = conf.getEnum(PropertyKey.SECURITY_AUTHENTICATION_TYPE, AuthType.class);
        // TODO(gpang): should this be more specific than a boolean, like PROCESS_TYPE?
        boolean isServer = !processType.equals(CommonUtils.ProcessType.CLIENT);
  
        for (UserStateFactory factory : FACTORIES) {
          UserState subjectState = factory.create(subject, conf, isServer);
          if (subjectState != null) {
            return subjectState;
          }
        }
        throw new UnsupportedOperationException(
            "No factory could create a UserState with authType: " + authType
                + ". factories: " + String.join(", ",
                FACTORIES.stream().map((factory) -> factory.getClass().getName())
                    .collect(Collectors.toList())));
      }
    }
  }
  