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 java.util.Iterator;
  import org.apache.arrow.flight.FlightClient;
  
  /**
   * Implement authentication for Flight on the client side.
   *
   * @deprecated As of 14.0.0. This implements a stateful "login" flow that does not play well with
   *     distributed or stateless systems. It will not be removed, but should not be used. Instead see
   *     {@link FlightClient#authenticateBasicToken(String, String)}.
   */
  @Deprecated
  public interface ClientAuthHandler {
    /**
     * Handle the initial handshake with the server.
     *
     * @param outgoing A channel to send data to the server.
     * @param incoming An iterator of incoming data from the server.
     */
    void authenticate(ClientAuthSender outgoing, Iterator<byte[]> incoming);
  
    /** Get the per-call authentication token. */
    byte[] getCallToken();
  
    /** A communication channel to the server during initial connection. */
    interface ClientAuthSender {
  
      /** Send the server a message. */
      void send(byte[] payload);
  
      /** Signal an error to the server and abort the authentication attempt. */
      void onError(Throwable cause);
    }
  }
  