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.conf.AlluxioConfiguration;
  import alluxio.conf.PropertyKey;
  import alluxio.exception.status.UnauthenticatedException;
  import alluxio.security.User;
  import alluxio.security.authentication.AuthType;
  import alluxio.security.login.AppLoginModule;
  import alluxio.security.login.LoginModuleConfiguration;
  import alluxio.util.SecurityUtils;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import java.util.Set;
  import javax.security.auth.Subject;
  import javax.security.auth.login.LoginContext;
  import javax.security.auth.login.LoginException;
  
  /**
   * UserState implementation for the simple authentication schemes.
   */
  public class SimpleUserState extends BaseUserState {
    private static final Logger LOG = LoggerFactory.getLogger(SimpleUserState.class);
  
    /**
     * Factory class to create the user state.
     */
    public static class Factory implements UserStateFactory {
      @Override
      public UserState create(Subject subject, AlluxioConfiguration conf, boolean isServer) {
        AuthType authType = conf.getEnum(PropertyKey.SECURITY_AUTHENTICATION_TYPE, AuthType.class);
        if (authType == AuthType.SIMPLE || authType == AuthType.CUSTOM) {
          return new SimpleUserState(subject, conf);
        }
        LOG.debug("N/A: auth type is not SIMPLE or CUSTOM. authType: {}", authType);
        return null;
      }
    }
  
    private SimpleUserState(Subject subject, AlluxioConfiguration conf) {
      super(subject, conf);
    }
  
    @Override
    public User login() throws UnauthenticatedException {
      String username = "";
      if (mConf.isSet(PropertyKey.SECURITY_LOGIN_USERNAME)) {
        username = mConf.getString(PropertyKey.SECURITY_LOGIN_USERNAME);
      }
      try {
        // Use the class loader of User.class to construct the LoginContext. LoginContext uses this
        // class loader to dynamically instantiate login modules. This enables
        // Subject#getPrincipals to use reflection to search for User.class instances.
        LoginContext loginContext =
            SecurityUtils.createLoginContext(AuthType.SIMPLE, mSubject, User.class.getClassLoader(),
                new LoginModuleConfiguration(), new AppLoginModule.AppCallbackHandler(username));
        loginContext.login();
      } catch (LoginException e) {
        throw new UnauthenticatedException("Failed to login: " + e.getMessage(), e);
      }
  
      LOG.debug("login subject: {}", mSubject);
      Set<User> userSet = mSubject.getPrincipals(User.class);
      if (userSet.isEmpty()) {
        throw new UnauthenticatedException("Failed to login: No Alluxio User is found.");
      }
      if (userSet.size() > 1) {
        StringBuilder msg = new StringBuilder(
            "Failed to login: More than one Alluxio Users are found:");
        for (User user : userSet) {
          msg.append(" ").append(user.toString());
        }
        throw new UnauthenticatedException(msg.toString());
      }
      return userSet.iterator().next();
    }
  }
  