content: /*
   * 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.
   */
  package org.apache.arrow.flight.auth;
  
  import com.google.protobuf.InvalidProtocolBufferException;
  import java.util.Iterator;
  import java.util.Optional;
  import org.apache.arrow.flight.impl.Flight.BasicAuth;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /** A ServerAuthHandler for username/password authentication. */
  public class BasicServerAuthHandler implements ServerAuthHandler {
  
    private static final Logger logger = LoggerFactory.getLogger(BasicServerAuthHandler.class);
    private final BasicAuthValidator authValidator;
  
    public BasicServerAuthHandler(BasicAuthValidator authValidator) {
      super();
      this.authValidator = authValidator;
    }
  
    /** Interface that this handler delegates for determining if credentials are valid. */
    public interface BasicAuthValidator {
  
      byte[] getToken(String username, String password) throws Exception;
  
      Optional<String> isValid(byte[] token);
    }
  
    @Override
    public boolean authenticate(ServerAuthSender outgoing, Iterator<byte[]> incoming) {
      byte[] bytes = incoming.next();
      try {
        BasicAuth auth = BasicAuth.parseFrom(bytes);
        byte[] token = authValidator.getToken(auth.getUsername(), auth.getPassword());
        outgoing.send(token);
        return true;
      } catch (InvalidProtocolBufferException e) {
        logger.debug("Failure parsing auth message.", e);
      } catch (Exception e) {
        logger.debug("Unknown error during authorization.", e);
      }
  
      return false;
    }
  
    @Override
    public Optional<String> isValid(byte[] token) {
      return authValidator.isValid(token);
    }
  }
  