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.anonymous;
  
  import static org.apache.celeborn.common.network.sasl.SaslUtils.*;
  
  import java.util.Map;
  
  import javax.security.auth.callback.CallbackHandler;
  import javax.security.sasl.SaslException;
  import javax.security.sasl.SaslServer;
  import javax.security.sasl.SaslServerFactory;
  
  /**
   * This implements the {@code SaslServerFactory} interface for the ANONYMOUS SASL mechanism. It
   * allows the creation of SASL servers that can handle ANONYMOUS authentication requests from
   * clients.
   */
  public class AnonymousSaslServerFactory implements SaslServerFactory {
  
    /**
     * Creates a SASL server for the ANONYMOUS mechanism.
     *
     * @param mechanism The requested SASL mechanism (e.g., ANONYMOUS).
     * @param protocol The name of the protocol being used.
     * @param serverName The name of the server.
     * @param props A map of properties to configure the SASL server.
     * @param cbh A callback handler for handling authentication callbacks.
     * @return A {@code CelebornAnonymousSaslServer} instance if ANONYMOUS is requested, or null
     *     otherwise.
     * @throws SaslException
     */
    @Override
    public SaslServer createSaslServer(
        String mechanism,
        String protocol,
        String serverName,
        Map<String, ?> props,
        CallbackHandler cbh)
        throws SaslException {
      if (mechanism.equals(ANONYMOUS)) {
        return new CelebornAnonymousSaslServer();
      }
      return null;
    }
  
    @Override
    public String[] getMechanismNames(Map<String, ?> props) {
      return new String[] {ANONYMOUS};
    }
  
    static class CelebornAnonymousSaslServer implements SaslServer {
      private boolean isCompleted = false;
  
      @Override
      public String getMechanismName() {
        return ANONYMOUS;
      }
  
      @Override
      public byte[] evaluateResponse(byte[] response) throws SaslException {
        if (isCompleted) {
          throw new IllegalStateException("Authentication has already completed.");
        }
        // Typically, we would process the response here. For ANONYMOUS, we just accept it.
        isCompleted = true;
        return new byte[0]; // No challenge is expected for ANONYMOUS.
      }
  
      @Override
      public boolean isComplete() {
        return isCompleted;
      }
  
      @Override
      public String getAuthorizationID() {
        return ANONYMOUS;
      }
  
      @Override
      public byte[] unwrap(byte[] incoming, int offset, int len) {
        throw new IllegalStateException("ANONYMOUS mechanism does not support wrap/unwrap");
      }
  
      @Override
      public byte[] wrap(byte[] outgoing, int offset, int len) {
        throw new IllegalStateException("ANONYMOUS mechanism does not support wrap/unwrap");
      }
  
      @Override
      public Object getNegotiatedProperty(String propName) {
        return null;
      }
  
      @Override
      public void dispose() {
        // Cleanup resources if any.
      }
    }
  }
  