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
   *
   *     https://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.avro.ipc;
  
  import java.io.IOException;
  import java.util.Map;
  import java.net.SocketAddress;
  import java.nio.channels.SocketChannel;
  import java.nio.charset.StandardCharsets;
  
  import javax.security.sasl.Sasl;
  import javax.security.sasl.SaslServer;
  import javax.security.sasl.SaslException;
  import javax.security.auth.callback.CallbackHandler;
  
  import org.slf4j.Logger;
  import org.slf4j.LoggerFactory;
  
  /**
   * A {@link Server} that uses {@link javax.security.sasl} for authentication and
   * encryption.
   */
  public class SaslSocketServer extends SocketServer {
    private static final Logger LOG = LoggerFactory.getLogger(SaslServer.class);
  
    private static abstract class SaslServerFactory {
      protected abstract SaslServer getServer() throws SaslException;
    }
  
    private SaslServerFactory factory;
  
    /**
     * Create using SASL's anonymous
     * (<a href="https://www.ietf.org/rfc/rfc2245.txt">RFC 2245) mechanism.
     */
    public SaslSocketServer(Responder responder, SocketAddress addr) throws IOException {
      this(responder, addr, new SaslServerFactory() {
        @Override
        public SaslServer getServer() {
          return new AnonymousServer();
        }
      });
    }
  
    /** Create using the specified {@link SaslServer} parameters. */
    public SaslSocketServer(Responder responder, SocketAddress addr, final String mechanism, final String protocol,
        final String serverName, final Map<String, ?> props, final CallbackHandler cbh) throws IOException {
      this(responder, addr, new SaslServerFactory() {
        @Override
        public SaslServer getServer() throws SaslException {
          return Sasl.createSaslServer(mechanism, protocol, serverName, props, cbh);
        }
      });
    }
  
    private SaslSocketServer(Responder responder, SocketAddress addr, SaslServerFactory factory) throws IOException {
      super(responder, addr);
      this.factory = factory;
    }
  
    @Override
    protected Transceiver getTransceiver(SocketChannel channel) throws IOException {
      return new SaslSocketTransceiver(channel, factory.getServer());
    }
  
    private static class AnonymousServer implements SaslServer {
      private String user;
  
      @Override
      public String getMechanismName() {
        return "ANONYMOUS";
      }
  
      @Override
      public byte[] evaluateResponse(byte[] response) throws SaslException {
        this.user = new String(response, StandardCharsets.UTF_8);
        return null;
      }
  
      @Override
      public boolean isComplete() {
        return user != null;
      }
  
      @Override
      public String getAuthorizationID() {
        return user;
      }
  
      @Override
      public byte[] unwrap(byte[] incoming, int offset, int len) {
        throw new UnsupportedOperationException();
      }
  
      @Override
      public byte[] wrap(byte[] outgoing, int offset, int len) {
        throw new UnsupportedOperationException();
      }
  
      @Override
      public Object getNegotiatedProperty(String propName) {
        return null;
      }
  
      @Override
      public void dispose() {
      }
    }
  
  }
  