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.celeborn.common.network.sasl;
  
  import static org.apache.celeborn.common.network.sasl.SaslUtils.*;
  
  import java.io.IOException;
  import java.nio.ByteBuffer;
  
  import io.netty.channel.Channel;
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import org.apache.celeborn.common.network.client.RpcResponseCallback;
  import org.apache.celeborn.common.network.client.TransportClient;
  import org.apache.celeborn.common.network.protocol.RequestMessage;
  import org.apache.celeborn.common.network.protocol.RpcRequest;
  import org.apache.celeborn.common.network.protocol.TransportMessage;
  import org.apache.celeborn.common.network.server.AbstractAuthRpcHandler;
  import org.apache.celeborn.common.network.server.BaseMessageHandler;
  import org.apache.celeborn.common.network.util.TransportConf;
  import org.apache.celeborn.common.protocol.PbSaslRequest;
  
  /**
   * RPC Handler which performs SASL authentication before delegating to a child RPC handler. The
   * delegate will only receive messages if the given connection has been successfully authenticated.
   * A connection may be authenticated at most once.
   *
   * <p>Note that the authentication process consists of multiple challenge-response pairs, each of
   * which are individual RPCs.
   */
  public class SaslRpcHandler extends AbstractAuthRpcHandler {
    private static final Logger logger = LoggerFactory.getLogger(SaslRpcHandler.class);
  
    /** Transport configuration. */
    private final TransportConf conf;
  
    /** The client channel. */
    private final Channel channel;
  
    /** Class which provides secret keys which are shared by server and client on a per-app basis. */
    private final SecretRegistry secretRegistry;
  
    private CelebornSaslServer saslServer;
  
    public SaslRpcHandler(
        TransportConf conf,
        Channel channel,
        BaseMessageHandler delegate,
        SecretRegistry secretRegistry) {
      super(delegate);
      this.conf = conf;
      this.channel = channel;
      this.secretRegistry = secretRegistry;
      this.saslServer = null;
    }
  
    @Override
    public boolean checkRegistered() {
      return delegate.checkRegistered();
    }
  
    @Override
    public boolean doAuthChallenge(
        TransportClient client, RequestMessage message, RpcResponseCallback callback) {
      if (saslServer == null || !saslServer.isComplete()) {
        RpcRequest rpcRequest = (RpcRequest) message;
        PbSaslRequest saslMessage;
        try {
          TransportMessage pbMsg = TransportMessage.fromByteBuffer(message.body().nioByteBuffer());
          saslMessage = pbMsg.getParsedPayload();
        } catch (IOException e) {
          logger.error("Error while parsing Sasl Message with RPC id {}", rpcRequest.requestId, e);
          callback.onFailure(e);
          return false;
        }
        if (saslServer == null) {
          saslServer =
              new CelebornSaslServer(
                  DIGEST_MD5,
                  DEFAULT_SASL_SERVER_PROPS,
                  new CelebornSaslServer.DigestCallbackHandler(client, secretRegistry));
        }
        byte[] response = saslServer.response(saslMessage.getPayload().toByteArray());
        callback.onSuccess(ByteBuffer.wrap(response));
      }
      if (saslServer.isComplete()) {
        logger.debug("SASL authentication successful for channel {}", client);
        complete();
        return true;
      }
      return false;
    }
  
    @Override
    public void channelInactive(TransportClient client) {
      super.channelInactive(client);
      cleanup();
    }
  
    private void complete() {
      cleanup();
    }
  
    public void cleanup() {
      if (null != saslServer) {
        try {
          saslServer.dispose();
        } catch (RuntimeException e) {
          logger.error("Error while disposing SASL server", e);
        } finally {
          saslServer = null;
        }
      }
    }
  }
  