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.camel.component.http;
  
  import java.io.IOException;
  
  import org.apache.hc.client5.http.auth.AuthCache;
  import org.apache.hc.client5.http.auth.AuthScheme;
  import org.apache.hc.client5.http.auth.AuthScope;
  import org.apache.hc.client5.http.auth.Credentials;
  import org.apache.hc.client5.http.auth.CredentialsProvider;
  import org.apache.hc.client5.http.classic.ExecChain;
  import org.apache.hc.client5.http.classic.ExecChainHandler;
  import org.apache.hc.client5.http.impl.auth.BasicAuthCache;
  import org.apache.hc.client5.http.impl.auth.BasicScheme;
  import org.apache.hc.client5.http.impl.auth.BearerScheme;
  import org.apache.hc.client5.http.impl.auth.NTLMScheme;
  import org.apache.hc.client5.http.protocol.HttpClientContext;
  import org.apache.hc.core5.http.ClassicHttpRequest;
  import org.apache.hc.core5.http.ClassicHttpResponse;
  import org.apache.hc.core5.http.HttpException;
  import org.apache.hc.core5.http.HttpHost;
  
  public class PreemptiveAuthExecChainHandler implements ExecChainHandler {
  
      private final HttpEndpoint endpoint;
  
      public PreemptiveAuthExecChainHandler(HttpEndpoint endpoint) {
          this.endpoint = endpoint;
      }
  
      @Override
      public ClassicHttpResponse execute(
              ClassicHttpRequest request,
              ExecChain.Scope scope,
              ExecChain chain)
              throws IOException, HttpException {
  
          HttpClientContext context = scope.clientContext;
          AuthCache authCache = context.getAuthCache();
          // If no auth scheme available yet, try to initialize it preemptively
          if (authCache == null) {
              CredentialsProvider credentialsProvider = context.getCredentialsProvider();
              HttpHost httpHost = scope.route.getTargetHost();
              Credentials credentials = credentialsProvider.getCredentials(new AuthScope(httpHost), context);
              if (credentials == null) {
                  credentials = HttpCredentialsHelper.getCredentials(endpoint.getAuthMethod(), endpoint.getAuthUsername(),
                          endpoint.getAuthPassword(), endpoint.getAuthHost(), endpoint.getAuthHost(),
                          endpoint.getAuthBearerToken());
              }
              if (credentials == null) {
                  throw new HttpException("No credentials for preemptive authentication");
              }
              AuthScheme authScheme;
              if ("NTLM".equalsIgnoreCase(endpoint.getAuthMethod())) {
                  authScheme = new NTLMScheme();
              } else if ("BEARER".equalsIgnoreCase(endpoint.getAuthMethod())) {
                  authScheme = new BearerScheme();
              } else {
                  BasicScheme bs = new BasicScheme();
                  bs.initPreemptive(credentials);
                  authScheme = bs;
              }
              authCache = new BasicAuthCache();
              authCache.put(httpHost, authScheme);
              context.setAuthCache(authCache);
          }
          return chain.proceed(request, scope);
      }
  }
  