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.kafka.common.security.oauthbearer.internals.secured;
  
  import org.apache.kafka.common.security.oauthbearer.JwtRetrieverException;
  import org.apache.kafka.common.utils.Utils;
  
  import com.fasterxml.jackson.databind.JsonNode;
  import com.fasterxml.jackson.databind.ObjectMapper;
  
  import java.io.IOException;
  
  public class JwtResponseParser {
  
      private static final String[] JSON_PATHS = new String[] {"/access_token", "/id_token"};
      private static final int MAX_RESPONSE_BODY_LENGTH = 1000;
  
      public String parseJwt(String responseBody) throws JwtRetrieverException {
          ObjectMapper mapper = new ObjectMapper();
          JsonNode rootNode;
  
          try {
              rootNode = mapper.readTree(responseBody);
          } catch (IOException e) {
              throw new JwtRetrieverException(e);
          }
  
          for (String jsonPath : JSON_PATHS) {
              JsonNode node = rootNode.at(jsonPath);
  
              if (node != null && !node.isMissingNode()) {
                  String value = node.textValue();
  
                  if (!Utils.isBlank(value)) {
                      return value.trim();
                  }
              }
          }
  
          // Only grab the first N characters so that if the response body is huge, we don't blow up.
          String snippet = responseBody;
  
          if (snippet.length() > MAX_RESPONSE_BODY_LENGTH) {
              int actualLength = responseBody.length();
              String s = responseBody.substring(0, MAX_RESPONSE_BODY_LENGTH);
              snippet = String.format("%s (trimmed to first %d characters out of %d total)", s, MAX_RESPONSE_BODY_LENGTH, actualLength);
          }
  
          throw new JwtRetrieverException(String.format("The token endpoint response did not contain a valid JWT. Response: (%s)", snippet));
      }
  }
  