SpringCloud Gateway实现请求解密和响应加密

前言

本文环境使用比较新的 Java 17 和 SpringBoot 3.1.5，对应到Spring的版本是 6.0.13
使用到的三方插件有：

• lombok
• gson
• hutool

本文注重实现请求的解密和响应的加密，加解密使用的是 Hutool 中的工具类，加解密算法目前提供了AES的方式，其余方式也可兼容扩展。
完整代码仓库：https://gitee.com/fengsoshuai/springcloud-gateway-feng-demo

借用网关中的过滤器GlobalFilter来实现这一功能。
本文只粘贴一些重点文件内容。

正文

一、项目简介

在聚合项目中，有两个核心模块，feng-server提供了 rest 接口，供网关使用。
feng-gateway 是核心实现的网关项目，实现了自定义过滤器，以及增加了一些基本配置功能。本文重心是网关项目。

二、核心代码

2.1 自定义过滤器

package org.feng.fenggateway.filters;import jakarta.annotation.Resource;
import lombok.extern.slf4j.Slf4j;
import org.feng.fenggateway.config.SecureProperties;
import org.feng.fenggateway.dto.ResponseDto;
import org.feng.fenggateway.secure.SecureComponent;
import org.feng.fenggateway.secure.SecureComponentFactory;
import org.feng.fenggateway.util.GsonUtil;
import org.reactivestreams.Publisher;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferFactory;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.core.io.buffer.DefaultDataBufferFactory;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.MediaType;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpRequestDecorator;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.http.server.reactive.ServerHttpResponseDecorator;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;import java.nio.charset.StandardCharsets;
import java.util.Objects;
import java.util.Set;/*** 自定义密文过滤器** @author feng*/
@Slf4j
@Component
public class CustomCipherTextFilter implements GlobalFilter, Ordered {@Resourceprivate SecureProperties secureProperties;private SecureComponent secureComponent;@Overridepublic Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {// 获取请求体ServerHttpRequest request = exchange.getRequest();// 获取响应体ServerHttpResponse response = exchange.getResponse();// 请求头HttpHeaders headers = request.getHeaders();// 请求方法HttpMethod method = request.getMethod();// 满足条件，进行过滤if (isNeedFilterMethod(method) && isNeedFilterContentType(headers.getContentType())) {return DataBufferUtils.join(request.getBody()).flatMap(dataBuffer -> {try {// 获取请求参数String originalRequestBody = getOriginalRequestBody(dataBuffer);// 解密请求参数String decryptRequestBody = decryptRequest(originalRequestBody);// 装饰新的请求体ServerHttpRequestDecorator requestDecorator = serverHttpRequestDecorator(request, decryptRequestBody);// 装饰新的响应体ServerHttpResponseDecorator responseDecorator = serverHttpResponseDecorator(response);// 使用新的请求和响应转发ServerWebExchange serverWebExchange = exchange.mutate().request(requestDecorator).response(responseDecorator).build();// 放行拦截return chain.filter(serverWebExchange);} catch (Exception e) {log.error("密文过滤器加解密错误", e);return Mono.empty();} finally {DataBufferUtils.release(dataBuffer);}});}return chain.filter(exchange);}private String decryptRequest(String originalRequestBody) {if (!secureProperties.enableDecryptRequestParam()) {log.info("请求参数解密，跳过");return originalRequestBody;}log.info("请求参数解密，原文：{}", originalRequestBody);String decrypted = getSecureComponent().decrypt(originalRequestBody);log.info("请求参数解密，明文：{}", decrypted);return decrypted;}private String encryptResponse(String originalResponseBody) {if (!secureProperties.enableEncryptResponseParam()) {log.info("响应结果加密，跳过");return originalResponseBody;}ResponseDto responseDto = GsonUtil.fromJson(originalResponseBody, ResponseDto.class);// 只对data字段进行加密处理Object data = responseDto.getData();if (Objects.nonNull(data)) {responseDto.setData(getSecureComponent().encrypt(data.toString()));}log.info("响应结果加密，原文：{}", originalResponseBody);String result = GsonUtil.toJson(responseDto);log.info("响应结果加密，密文：{}", result);return result;}/*** 获取原始的请求参数** @param dataBuffer 数据缓冲* @return 原始的请求参数*/private String getOriginalRequestBody(DataBuffer dataBuffer) {byte[] bytes = new byte[dataBuffer.readableByteCount()];dataBuffer.read(bytes);return new String(bytes, StandardCharsets.UTF_8);}private boolean isNeedFilterMethod(HttpMethod method) {return NEED_FILTER_METHOD_SET.contains(method);}private boolean isNeedFilterContentType(MediaType mediaType) {return NEED_FILTER_MEDIA_TYPE_SET.contains(mediaType) || "json".equals(mediaType.getSubtype());}private ServerHttpRequestDecorator serverHttpRequestDecorator(ServerHttpRequest originalRequest, String decryptRequestBody) {return new ServerHttpRequestDecorator(originalRequest) {@Overridepublic HttpHeaders getHeaders() {HttpHeaders httpHeaders = new HttpHeaders();httpHeaders.putAll(super.getHeaders());httpHeaders.remove(HttpHeaders.CONTENT_LENGTH);httpHeaders.set(HttpHeaders.TRANSFER_ENCODING, "chunked");return httpHeaders;}@Overridepublic Flux<DataBuffer> getBody() {byte[] bytes = decryptRequestBody.getBytes(StandardCharsets.UTF_8);return Flux.just(new DefaultDataBufferFactory().wrap(bytes));}};}private ServerHttpResponseDecorator serverHttpResponseDecorator(ServerHttpResponse originalResponse) {DataBufferFactory dataBufferFactory = originalResponse.bufferFactory();return new ServerHttpResponseDecorator(originalResponse) {@Overridepublic Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {if (body instanceof Flux<? extends DataBuffer> fluxBody) {return super.writeWith(fluxBody.buffer().map(dataBuffers -> {DataBuffer join = dataBufferFactory.join(dataBuffers);byte[] byteArray = new byte[join.readableByteCount()];join.read(byteArray);DataBufferUtils.release(join);String originalResponseBody = new String(byteArray, StandardCharsets.UTF_8);//加密byte[] encryptedByteArray = encryptResponse(originalResponseBody).getBytes(StandardCharsets.UTF_8);originalResponse.getHeaders().setContentLength(encryptedByteArray.length);originalResponse.getHeaders().setContentType(MediaType.APPLICATION_JSON_UTF8);return dataBufferFactory.wrap(encryptedByteArray);}));}return super.writeWith(body);}@Overridepublic Mono<Void> writeAndFlushWith(Publisher<? extends Publisher<? extends DataBuffer>> body) {return writeWith(Flux.from(body).flatMapSequential(p -> p));}@Overridepublic HttpHeaders getHeaders() {HttpHeaders headers = new HttpHeaders();headers.putAll(originalResponse.getHeaders());return headers;}};}private static final Set<HttpMethod> NEED_FILTER_METHOD_SET = Set.of(HttpMethod.GET, HttpMethod.POST, HttpMethod.PUT);private static final Set<MediaType> NEED_FILTER_MEDIA_TYPE_SET = Set.of(MediaType.APPLICATION_JSON);@Overridepublic int getOrder() {return -1;}public SecureComponent getSecureComponent() {if (Objects.isNull(secureComponent)) {secureComponent = SecureComponentFactory.get(secureProperties.getAlgorithm());}return secureComponent;}
}

2.2 网关配置

server:port: 10010 # 网关端口
spring:application:name: gateway # 服务名称cloud:gateway:routes: # 网关路由配置- id: feng-server1 # 路由id，自定义，只要唯一即可uri: http://127.0.0.1:8081 # 路由的目标地址 http就是固定地址predicates: # 路由断言，也就是判断请求是否符合路由规则的条件- Path=/server/list/server1/** # 这个是按照路径匹配，只要以/user/开头就符合要求- id: feng-server2uri: http://127.0.0.1:8082predicates:- Path=/server/list/server2/**# 自定义配置
feng:gateway:secure:request-switch:enable: falseresponse-switch:enable: truealgorithm: aes

2.3 自定义配置类

package org.feng.fenggateway.config;import cn.hutool.crypto.symmetric.SymmetricAlgorithm;
import lombok.Data;
import lombok.extern.slf4j.Slf4j;
import org.feng.fenggateway.secure.SecureComponentFactory;
import org.springframework.boot.context.properties.ConfigurationProperties;import java.util.Objects;/*** 加解密属性配置** @author feng*/
@Slf4j
@Data
@ConfigurationProperties(prefix = SecureProperties.SECURE_PROPERTIES_PREFIX)
public class SecureProperties {public static final String SECURE_PROPERTIES_PREFIX = "feng.gateway.secure";/*** 算法*/private SymmetricAlgorithm algorithm;/*** 请求开关*/private SecureSwitch requestSwitch;/*** 响应开关*/private SecureSwitch responseSwitch;public void checkSupportedAlgorithm() {log.info("校验是否支持算法：{}", algorithm);if (Objects.isNull(algorithm)) {return;}boolean supportedAlgorithm = SecureComponentFactory.isSupportedAlgorithm(algorithm);if (!supportedAlgorithm) {throw new UnsupportedOperationException("不支持的算法");}log.info("校验是否支持算法：校验通过");}/*** 是否启用解密请求参数** @return 默认为否，其他情况看配置*/public boolean enableDecryptRequestParam() {if (Objects.isNull(requestSwitch)) {return false;}return requestSwitch.getEnable();}/*** 是否启用加密响应参数** @return 默认为否，其他情况看配置*/public boolean enableEncryptResponseParam() {if (Objects.isNull(responseSwitch)) {return false;}return responseSwitch.getEnable();}
}

2.4 加密组件接口

这个可以用来扩展支持其他加密算法，目前实现类只有AES。

package org.feng.fenggateway.secure;import cn.hutool.crypto.symmetric.SymmetricAlgorithm;
import jakarta.annotation.PostConstruct;/*** 加解密组件** @author feng*/
public interface SecureComponent {/*** 加密** @param originalText 原文* @return 密文*/String encrypt(String originalText);/*** 解密** @param encryptedText 密文* @return 解密后的明文*/String decrypt(String encryptedText);/*** 获取加解密算法类型** @return 加解密算法类型*/SymmetricAlgorithm getAlgorithmType();@PostConstructdefault void registerToFactory() {SecureComponentFactory.registerBean(this);}
}

2.5 加密组件实现，AES算法

package org.feng.fenggateway.secure;import cn.hutool.crypto.Mode;
import cn.hutool.crypto.Padding;
import cn.hutool.crypto.symmetric.AES;
import cn.hutool.crypto.symmetric.SymmetricAlgorithm;
import org.springframework.stereotype.Component;import java.nio.charset.StandardCharsets;/*** AES加解密组件** @author feng*/
@Component
public class SecureAESComponent implements SecureComponent {/*** 生成密钥，16、24、32位都行*/private final static byte[] SECURE_KEY = "r4oz0f3kfk5tgyui".getBytes(StandardCharsets.UTF_8);/*** 偏移量，必须16位*/private final static String IV = "r21g95kdsd423gy6";private final static AES AES_INSTANCE = new AES(Mode.CTS, Padding.PKCS5Padding, SECURE_KEY, IV.getBytes(StandardCharsets.UTF_8));@Overridepublic String encrypt(String originalText) {return AES_INSTANCE.encryptHex(originalText);}@Overridepublic String decrypt(String encryptedText) {return AES_INSTANCE.decryptStr(encryptedText);}@Overridepublic SymmetricAlgorithm getAlgorithmType() {return SymmetricAlgorithm.AES;}
}

2.6 启动类，校验支持的算法配置

package org.feng.fenggateway;import jakarta.annotation.Resource;
import org.feng.fenggateway.config.SecureProperties;
import org.springframework.boot.CommandLineRunner;
import org.springframework.boot.SpringApplication;
import org.springframework.boot.autoconfigure.SpringBootApplication;
import org.springframework.boot.context.properties.ConfigurationPropertiesScan;@ConfigurationPropertiesScan
@SpringBootApplication
public class FengGatewayApplication implements CommandLineRunner {@Resourceprivate SecureProperties secureProperties;public static void main(String[] args) {SpringApplication.run(FengGatewayApplication.class, args);}@Overridepublic void run(String... args) {secureProperties.checkSupportedAlgorithm();}
}

三、请求报文示例

POST http://localhost:10010/server/list/server2/user?authorization=feng
Content-Type: application/json;charset=UTF-8{"username": "fbb"
}

四、测试结果

4.1 网关项目启动时

校验结果正常：

4.2 发生请求时

可以看到data字段已经加密响应了。

请求和响应结果：