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.auth2;
  
  import static org.apache.arrow.flight.auth2.CallHeaderAuthenticator.AuthResult;
  
  import org.apache.arrow.flight.CallHeaders;
  import org.apache.arrow.flight.CallInfo;
  import org.apache.arrow.flight.CallStatus;
  import org.apache.arrow.flight.FlightServerMiddleware;
  import org.apache.arrow.flight.RequestContext;
  
  /**
   * Middleware that's used to validate credentials during the handshake and verify the bearer token
   * in subsequent requests.
   */
  public class ServerCallHeaderAuthMiddleware implements FlightServerMiddleware {
    /** Factory for accessing ServerAuthMiddleware. */
    public static class Factory
        implements FlightServerMiddleware.Factory<ServerCallHeaderAuthMiddleware> {
      private final CallHeaderAuthenticator authHandler;
  
      /**
       * Construct a factory with the given auth handler.
       *
       * @param authHandler The auth handler what will be used for authenticating requests.
       */
      public Factory(CallHeaderAuthenticator authHandler) {
        this.authHandler = authHandler;
      }
  
      @Override
      public ServerCallHeaderAuthMiddleware onCallStarted(
          CallInfo callInfo, CallHeaders incomingHeaders, RequestContext context) {
        final AuthResult result = authHandler.authenticate(incomingHeaders);
        context.put(Auth2Constants.PEER_IDENTITY_KEY, result.getPeerIdentity());
        return new ServerCallHeaderAuthMiddleware(result);
      }
    }
  
    private final AuthResult authResult;
  
    public ServerCallHeaderAuthMiddleware(AuthResult authResult) {
      this.authResult = authResult;
    }
  
    @Override
    public void onBeforeSendingHeaders(CallHeaders outgoingHeaders) {
      authResult.appendToOutgoingHeaders(outgoingHeaders);
    }
  
    @Override
    public void onCallCompleted(CallStatus status) {}
  
    @Override
    public void onCallErrored(Throwable err) {}
  }
  