content: /*
   * Copyright 1999-2018 Alibaba Group Holding Ltd.
   *
   * Licensed 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 com.alibaba.nacos.client.config.filter.impl;
  
  import com.alibaba.nacos.api.config.filter.AbstractConfigFilter;
  import com.alibaba.nacos.api.config.filter.IConfigFilterChain;
  import com.alibaba.nacos.api.config.filter.IConfigRequest;
  import com.alibaba.nacos.api.config.filter.IConfigResponse;
  import com.alibaba.nacos.api.exception.NacosException;
  import com.alibaba.nacos.common.utils.Pair;
  import com.alibaba.nacos.common.utils.StringUtils;
  import com.alibaba.nacos.plugin.encryption.handler.EncryptionHandler;
  
  import java.util.Objects;
  import java.util.Properties;
  
  /**
   * Configure encryption filter.
   *
   * @author lixiaoshuang
   */
  public class ConfigEncryptionFilter extends AbstractConfigFilter {
      
      private static final String DEFAULT_NAME = ConfigEncryptionFilter.class.getName();
      
      @Override
      public void init(Properties properties) {
      
      }
      
      @Override
      public void doFilter(IConfigRequest request, IConfigResponse response, IConfigFilterChain filterChain)
              throws NacosException {
          if (Objects.nonNull(request) && request instanceof ConfigRequest && Objects.isNull(response)) {
              
              // Publish configuration, encrypt
              ConfigRequest configRequest = (ConfigRequest) request;
              String dataId = configRequest.getDataId();
              String content = configRequest.getContent();
              
              Pair<String, String> pair = EncryptionHandler.encryptHandler(dataId, content);
              String secretKey = pair.getFirst();
              String encryptContent = pair.getSecond();
              if (!StringUtils.isBlank(encryptContent) && !encryptContent.equals(content)) {
                  ((ConfigRequest) request).setContent(encryptContent);
              }
              if (!StringUtils.isBlank(secretKey) && !secretKey.equals(((ConfigRequest) request).getEncryptedDataKey())) {
                  ((ConfigRequest) request).setEncryptedDataKey(secretKey);
              } else if (StringUtils.isBlank(((ConfigRequest) request).getEncryptedDataKey()) && StringUtils.isBlank(secretKey)) {
                  ((ConfigRequest) request).setEncryptedDataKey("");
              }
          }
          if (Objects.nonNull(response) && response instanceof ConfigResponse && Objects.isNull(request)) {
              
              // Get configuration, decrypt
              ConfigResponse configResponse = (ConfigResponse) response;
              
              String dataId = configResponse.getDataId();
              String encryptedDataKey = configResponse.getEncryptedDataKey();
              String content = configResponse.getContent();
              
              Pair<String, String> pair = EncryptionHandler.decryptHandler(dataId, encryptedDataKey, content);
              String secretKey = pair.getFirst();
              String decryptContent = pair.getSecond();
              if (!StringUtils.isBlank(decryptContent) && !decryptContent.equals(content)) {
                  ((ConfigResponse) response).setContent(decryptContent);
              }
              if (!StringUtils.isBlank(secretKey) && !secretKey.equals(((ConfigResponse) response).getEncryptedDataKey())) {
                  ((ConfigResponse) response).setEncryptedDataKey(secretKey);
              } else if (StringUtils.isBlank(((ConfigResponse) response).getEncryptedDataKey()) && StringUtils.isBlank(secretKey)) {
                  ((ConfigResponse) response).setEncryptedDataKey("");
              }
          }
          filterChain.doFilter(request, response);
      }
      
      @Override
      public int getOrder() {
          return 0;
      }
      
      @Override
      public String getFilterName() {
          return DEFAULT_NAME;
      }
      
  }
  