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.cassandra.net;
  
  import java.nio.channels.ClosedChannelException;
  import java.security.cert.Certificate;
  import javax.net.ssl.SSLPeerUnverifiedException;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  import io.netty.buffer.ByteBuf;
  import io.netty.channel.Channel;
  import io.netty.channel.ChannelHandlerContext;
  import io.netty.channel.ChannelInboundHandlerAdapter;
  import io.netty.handler.ssl.SslHandler;
  
  /**
   * Class that contains certificate utility methods.
   */
  public class InternodeConnectionUtils
  {
      public static String SSL_HANDLER_NAME = "ssl";
      public static String DISCARD_HANDLER_NAME = "discard";
      public static String SSL_FACTORY_CONTEXT_DESCRIPTION = "server_encryption_options";
      private static final Logger logger = LoggerFactory.getLogger(InternodeConnectionUtils.class);
  
      public static Certificate[] certificates(Channel channel)
      {
          final SslHandler sslHandler = (SslHandler) channel.pipeline().get(SSL_HANDLER_NAME);
          Certificate[] certificates = null;
          if (sslHandler != null)
          {
              try
              {
                  certificates = sslHandler.engine()
                                           .getSession()
                                           .getPeerCertificates();
              }
              catch (SSLPeerUnverifiedException e)
              {
                  logger.debug("Failed to get peer certificates for peer {}", channel.remoteAddress(), e);
              }
          }
          return certificates;
      }
  
      public static boolean isSSLError(final Throwable cause)
      {
          return (cause instanceof ClosedChannelException)
                 && cause.getCause() == null
                 && cause.getStackTrace()[0].getClassName().contains("SslHandler")
                 && cause.getStackTrace()[0].getMethodName().contains("channelInactive");
      }
  
      /**
       * Discard handler releases the received data silently. when internode authentication fails, the channel is closed,
       * but the pending buffered data may still be fired through the pipeline. To avoid that, authentication handler is
       * replaced with this DiscardHandler to release all the buffered data, to avoid handling unauthenticated data in the
       * following handlers.
       */
      public static class ByteBufDiscardHandler extends ChannelInboundHandlerAdapter
      {
          @Override
          public void channelRead(ChannelHandlerContext ctx, Object msg)
          {
              if (msg instanceof ByteBuf)
              {
                  ((ByteBuf) msg).release();
              }
              else
              {
                  ctx.fireChannelRead(msg);
              }
          }
      }
  }
  