SpringCloud-Gateway实现RSA加解密
Gateway网关作为流量的入口，有的接口可能需要对请求内容加密，返回结果加密，保证数据安全性。
一、RSA介绍
RSA主要使用大整数分解这个数学难题进行设计，巧妙地利用了数论的概念。给了RSA公钥，首先想到的攻击就是分解模数，给了的因子攻击者可以计算得到，从而也可以计算得到解密指数，我们称这种分解模数的方法为针对RSA的暴力攻击。虽然分解算法已经稳步改进，但是在正确使用RSA情况下，当前的技术水平仍远未对RSA的安全性构成威胁。
相关讨论：RSA的公钥和私钥到底哪个才是用来加密和哪个用来解密？ - 知乎
项目相关依赖：SpringCloud-Gateway实现网关_W_Meng_H的博客-CSDN博客
二、相关工具类
RSA工具类：
import com.example.gateway.common.CommonConstant;
import javax.crypto.Cipher;
import java.io.ByteArrayOutputStream;
import java.security.*;
import java.security.interfaces.RSAPrivateKey;
import java.security.interfaces.RSAPublicKey;
import java.security.spec.PKCS8EncodedKeySpec;
import java.security.spec.X509EncodedKeySpec;
import java.util.*;/*** @Author: meng* @Description: RSA加密工具类* @Date: 2023/4/3 9:27* @Version: 1.0*/
public class RSAUtils {public static final String CHARSET = "UTF-8";// 加密算法private final static String ALGORITHM_RSA = "RSA";//公钥public static final String PUBLIC_KEY = "publicKey";//私钥public static final String PRIVATE_KEY = "privateKey";/*** @param modulus* @throws NoSuchAlgorithmException* @Description: 直接生成公钥、私钥对象*/public static List<Key> getRSAKeyObject(int modulus) throws NoSuchAlgorithmException {List<Key> keyList = new ArrayList<>(2);// 创建RSA密钥生成器KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(ALGORITHM_RSA);// 设置密钥的大小，此处是RSA算法的模长 = 最大加密数据的大小keyPairGen.initialize(modulus);KeyPair keyPair = keyPairGen.generateKeyPair();// keyPair.getPublic() 生成的是RSAPublic的是咧keyList.add(keyPair.getPublic());// keyPair.getPrivate() 生成的是RSAPrivateKey的实例keyList.add(keyPair.getPrivate());return keyList;}/*** @param modulus 模长* @return* @throws NoSuchAlgorithmException* @Description: 生成公钥、私钥的字符串*/public static Map<String, String> getRSAKeyString(int modulus) throws NoSuchAlgorithmException {// map装载公钥和私钥Map<String, String> keyPairMap = new HashMap<String, String>();KeyPairGenerator keyPairGen = KeyPairGenerator.getInstance(ALGORITHM_RSA);keyPairGen.initialize(modulus);KeyPair keyPair = keyPairGen.generateKeyPair();String publicKey = Base64.getEncoder().encodeToString(keyPair.getPublic().getEncoded());String privateKey = Base64.getEncoder().encodeToString(keyPair.getPrivate().getEncoded());keyPairMap.put(PUBLIC_KEY, publicKey);keyPairMap.put(PRIVATE_KEY, privateKey);return keyPairMap;}/*** @throws Exception* @Description: Java中RSAPublicKeySpec、X509EncodedKeySpec支持生成RSA公钥* 此处使用X509EncodedKeySpec生成* @Param: privateKey* @Author: wmh* @Date: 2023/4/3 10:15*/public static RSAPublicKey getPublicKey(String publicKey) throws Exception {KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);byte[] keyBytes = Base64.getDecoder().decode(publicKey);X509EncodedKeySpec spec = new X509EncodedKeySpec(keyBytes);return (RSAPublicKey) keyFactory.generatePublic(spec);}/*** @throws Exception* @Description: Java中只有RSAPrivateKeySpec、PKCS8EncodedKeySpec支持生成RSA私钥* 此处使用PKCS8EncodedKeySpec生成* @Param: privateKey* @Author: wmh* @Date: 2023/4/3 10:15*/public static RSAPrivateKey getPrivateKey(String privateKey) throws Exception {KeyFactory keyFactory = KeyFactory.getInstance(ALGORITHM_RSA);byte[] keyBytes = Base64.getDecoder().decode(privateKey);PKCS8EncodedKeySpec spec = new PKCS8EncodedKeySpec(keyBytes);return (RSAPrivateKey) keyFactory.generatePrivate(spec);}/*** @param data* @param publicKey* @throws Exception* @Description: 公钥加密*/public static String encryptByPublicKey(String data, RSAPublicKey publicKey)throws Exception {Cipher cipher = Cipher.getInstance(ALGORITHM_RSA);cipher.init(Cipher.ENCRYPT_MODE, publicKey);// 模长n转换成字节数int modulusSize = publicKey.getModulus().bitLength() / 8;// PKCS Padding长度为11字节，所以实际要加密的数据不能要 - 11byteint maxSingleSize = modulusSize - 11;// 切分字节数组，每段不大于maxSingleSizebyte[][] dataArray = splitArray(data.getBytes(CHARSET), maxSingleSize);ByteArrayOutputStream out = new ByteArrayOutputStream();// 分组加密，并将加密后的内容写入输出字节流for (byte[] s : dataArray) {out.write(cipher.doFinal(s));}// 使用Base64将字节数组转换String类型return Base64.getEncoder().encodeToString(out.toByteArray());}/*** @param data* @param privateKey* @throws Exception* @Description: 私钥解密*/public static String decryptByPrivateKey(String data, RSAPrivateKey privateKey)throws Exception {Cipher cipher = Cipher.getInstance(ALGORITHM_RSA);cipher.init(Cipher.DECRYPT_MODE, privateKey);// RSA加密算法的模长 nint modulusSize = privateKey.getModulus().bitLength() / 8;byte[] dataBytes = data.getBytes(CHARSET);// 之前加密的时候做了转码，此处需要使用Base64进行解码byte[] decodeData = Base64.getDecoder().decode(dataBytes);// 切分字节数组，每段不大于modulusSizebyte[][] splitArrays = splitArray(decodeData, modulusSize);ByteArrayOutputStream out = new ByteArrayOutputStream();for (byte[] arr : splitArrays) {out.write(cipher.doFinal(arr));}return new String(out.toByteArray());}/*** @param data* @param privateKey* @throws Exception* @Description: 公钥加密*/public static String encryptByPrivateKey(String data, RSAPrivateKey privateKey)throws Exception {Cipher cipher = Cipher.getInstance(ALGORITHM_RSA);cipher.init(Cipher.ENCRYPT_MODE, privateKey);// 模长n转换成字节数int modulusSize = privateKey.getModulus().bitLength() / 8;// PKCS Padding长度为11字节，所以实际要加密的数据不能要 - 11byteint maxSingleSize = modulusSize - 11;// 切分字节数组，每段不大于maxSingleSizebyte[][] dataArray = splitArray(data.getBytes(CHARSET), maxSingleSize);ByteArrayOutputStream out = new ByteArrayOutputStream();// 分组加密，并将加密后的内容写入输出字节流for (byte[] s : dataArray) {out.write(cipher.doFinal(s));}// 使用Base64将字节数组转换String类型return Base64.getEncoder().encodeToString(out.toByteArray());}/*** @param data* @param publicKey* @throws Exception* @Description: 公钥解密*/public static String decryptByPublicKey(String data, RSAPublicKey publicKey)throws Exception {Cipher cipher = Cipher.getInstance(ALGORITHM_RSA);cipher.init(Cipher.DECRYPT_MODE, publicKey);// RSA加密算法的模长 nint modulusSize = publicKey.getModulus().bitLength() / 8;byte[] dataBytes = data.getBytes(CHARSET);// 之前加密的时候做了转码，此处需要使用Base64进行解码byte[] decodeData = Base64.getDecoder().decode(dataBytes);// 切分字节数组，每段不大于modulusSizebyte[][] splitArrays = splitArray(decodeData, modulusSize);ByteArrayOutputStream out = new ByteArrayOutputStream();for (byte[] arr : splitArrays) {out.write(cipher.doFinal(arr));}return new String(out.toByteArray());}/*** @param data* @param len 单个字节数组长度* @Description: 按指定长度切分数组*/private static byte[][] splitArray(byte[] data, int len) {int dataLen = data.length;if (dataLen <= len) {return new byte[][]{data};}byte[][] result = new byte[(dataLen - 1) / len + 1][];int resultLen = result.length;for (int i = 0; i < resultLen; i++) {if (i == resultLen - 1) {int slen = dataLen - len * i;byte[] single = new byte[slen];System.arraycopy(data, len * i, single, 0, slen);result[i] = single;break;}byte[] single = new byte[len];System.arraycopy(data, len * i, single, 0, len);result[i] = single;}return result;}public static void main(String[] args) throws Exception {Map<String, String> keyStringList = RSAUtils.getRSAKeyString(1024);String pukString = CommonConstant.RSA_PUBLIC_KEY;String prkString = CommonConstant.RSA_PRIVATE_KEY;System.out.println("公钥:" + pukString);System.out.println("私钥:" + prkString);// 生成公钥、私钥RSAPublicKey puk = RSAUtils.getPublicKey(pukString);RSAPrivateKey prk = RSAUtils.getPrivateKey(prkString);String message = "{\\"message\\":\\"test\\",\\"name\\":\\"test\\"}";String encryptedMsg = RSAUtils.encryptByPublicKey(message, puk);String decryptedMsg = RSAUtils.decryptByPrivateKey(encryptedMsg, prk);System.out.println("未加密内容:" + message);System.out.println("公钥加密内容:" + encryptedMsg);System.out.println("私钥解密内容:" + decryptedMsg);System.out.println("-----------------------------------");}}
常用变量类：
import com.alibaba.fastjson.JSONObject;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpStatus;
import org.springframework.http.MediaType;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Mono;/*** @Author: meng* @Description: 常用变量* @Date: 2023/3/30 10:29* @Version: 1.0*/
@Component
public class CommonConstant {//JWT密钥public static final String JWT_TOKEN = "jwt-token";//请求头中的tokenpublic static final String X_TOKEN = "X-TOKEN";//请求头中的signpublic static final String X_SIGN = "X-SIGN";public static final String X_APPID = "X-APPID";public static final String CODE = "code";public static final String MESSAGE = "message";public static final String UTF8 = "UTF-8";public static final String RSA_PUBLIC_KEY = "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQDFJIl4il6nDBlF/3byWB/KXRqfEXkviz7ZvO7TU7JBfh7sFqfgLtJFDSA33+qTHOtYTCjCrwl6oWWX7Aff39HiFW1IBnhKjYdSK5/8ruQY+Y2xbpBMgslA0m2euOv3XPJUXWh0JGBqPllgzvtbtUA1iBELAHVYBACuQPYP2VcPeQIDAQAB";public static final String RSA_PRIVATE_KEY = "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";//公共返回方法public static Mono<Void> buildResponse(ServerWebExchange exchange, int code, String message) {ServerHttpResponse response = exchange.getResponse();response.setStatusCode(HttpStatus.OK);response.getHeaders().add(HttpHeaders.CONTENT_TYPE, MediaType.APPLICATION_JSON_UTF8_VALUE);JSONObject jsonObject = new JSONObject();jsonObject.put(CODE, code);jsonObject.put(MESSAGE, message);DataBuffer bodyDataBuffer = response.bufferFactory().wrap(jsonObject.toJSONString().getBytes());return response.writeWith(Mono.just(bodyDataBuffer));}
}
PS：我们想要实现对请求参数解密，需要解决获取body参数，只能获取一次的问题，网上有很多解决方案了，大家可以自行搜索。
推荐一个：SpringCloud-Gateway获取body参数，解决只能获取一次问题，终极解决方案_kamjin1996的博客-CSDN博客
不想看上边的博客，直接使用如下代码即可：
import com.example.gateway.common.GatewayContext;
import io.netty.buffer.ByteBufAllocator;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.GlobalFilter;
import org.springframework.core.Ordered;
import org.springframework.core.io.ByteArrayResource;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferUtils;
import org.springframework.core.io.buffer.NettyDataBufferFactory;
import org.springframework.http.HttpHeaders;
import org.springframework.http.MediaType;
import org.springframework.http.codec.HttpMessageReader;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpRequestDecorator;
import org.springframework.http.server.reactive.ServerHttpResponse;
import org.springframework.stereotype.Component;
import org.springframework.util.MultiValueMap;
import org.springframework.web.reactive.function.server.HandlerStrategies;
import org.springframework.web.reactive.function.server.ServerRequest;
import org.springframework.web.server.ServerWebExchange;
import reactor.core.publisher.Flux;
import reactor.core.publisher.Mono;import java.io.UnsupportedEncodingException;
import java.net.URLEncoder;
import java.nio.charset.Charset;
import java.nio.charset.StandardCharsets;
import java.util.List;
import java.util.Map;/*** @Author: https://blog.csdn.net/zx156955/article/details/115004910* @Description: 请求内容存储 处理请求内容 内容放在gatewayContext中* @Date: 2023/3/30 10:11* @Version: 1.0*/
@Component
@Slf4j
public class RequestCoverFilter implements GlobalFilter, Ordered {/*** default HttpMessageReader*/private static final List<HttpMessageReader<?>> messageReaders = HandlerStrategies.withDefaults().messageReaders();/*** ReadFormData** @param exchange* @param chain* @return*/private Mono<Void> readFormData(ServerWebExchange exchange, GatewayFilterChain chain,GatewayContext gatewayContext) {final ServerHttpRequest request = exchange.getRequest();HttpHeaders headers = request.getHeaders();return exchange.getFormData().doOnNext(multiValueMap -> {gatewayContext.setFormData(multiValueMap);log.debug("[GatewayContext]Read FormData:{}", multiValueMap);}).then(Mono.defer(() -> {Charset charset = headers.getContentType().getCharset();charset = charset == null ? StandardCharsets.UTF_8 : charset;String charsetName = charset.name();MultiValueMap<String, String> formData = gatewayContext.getFormData();/*** formData is empty just return*/if (null == formData || formData.isEmpty()) {return chain.filter(exchange);}StringBuilder formDataBodyBuilder = new StringBuilder();String entryKey;List<String> entryValue;try {/*** repackage form data*/for (Map.Entry<String, List<String>> entry : formData.entrySet()) {entryKey = entry.getKey();entryValue = entry.getValue();if (entryValue.size() > 1) {for (String value : entryValue) {formDataBodyBuilder.append(entryKey).append("=").append(URLEncoder.encode(value, charsetName)).append("&");}} else {formDataBodyBuilder.append(entryKey).append("=").append(URLEncoder.encode(entryValue.get(0), charsetName)).append("&");}}} catch (UnsupportedEncodingException e) {// ignore URLEncode Exception}/*** substring with the last char '&'*/String formDataBodyString = "";if (formDataBodyBuilder.length() > 0) {formDataBodyString = formDataBodyBuilder.substring(0, formDataBodyBuilder.length() - 1);}/*** get data bytes*/byte[] bodyBytes = formDataBodyString.getBytes(charset);int contentLength = bodyBytes.length;ServerHttpRequestDecorator decorator = new ServerHttpRequestDecorator(request) {/*** change content-length** @return*/@Overridepublic HttpHeaders getHeaders() {HttpHeaders httpHeaders = new HttpHeaders();httpHeaders.putAll(super.getHeaders());if (contentLength > 0) {httpHeaders.setContentLength(contentLength);} else {httpHeaders.set(HttpHeaders.TRANSFER_ENCODING, "chunked");}return httpHeaders;}/*** read bytes to Flux<Databuffer>** @return*/@Overridepublic Flux<DataBuffer> getBody() {return DataBufferUtils.read(new ByteArrayResource(bodyBytes),new NettyDataBufferFactory(ByteBufAllocator.DEFAULT), contentLength);}};ServerWebExchange mutateExchange = exchange.mutate().request(decorator).build();log.info("[GatewayContext]Rewrite Form Data :{}", formDataBodyString);return chain.filter(mutateExchange);}));}/*** ReadJsonBody** @param exchange* @param chain* @return*/private Mono<Void> readBody(ServerWebExchange exchange, GatewayFilterChain chain, GatewayContext gatewayContext) {/*** join the body*/return DataBufferUtils.join(exchange.getRequest().getBody()).flatMap(dataBuffer -> {/** read the body Flux<DataBuffer>, and release the buffer* see PR https://github.com/spring-cloud/spring-cloud-gateway/pull/1095*/byte[] bytes = new byte[dataBuffer.readableByteCount()];dataBuffer.read(bytes);DataBufferUtils.release(dataBuffer);Flux<DataBuffer> cachedFlux = Flux.defer(() -> {DataBuffer buffer = exchange.getResponse().bufferFactory().wrap(bytes);DataBufferUtils.retain(buffer);return Mono.just(buffer);});/*** repackage ServerHttpRequest*/ServerHttpRequest mutatedRequest = new ServerHttpRequestDecorator(exchange.getRequest()) {@Overridepublic Flux<DataBuffer> getBody() {return cachedFlux;}};/*** mutate exchage with new ServerHttpRequest*/ServerWebExchange mutatedExchange = exchange.mutate().request(mutatedRequest).build();/*** read body string with default messageReaders*/return ServerRequest.create(mutatedExchange, messageReaders).bodyToMono(String.class).doOnNext(objectValue -> {gatewayContext.setCacheBody(objectValue);log.debug("[GatewayContext]Read JsonBody:{}", objectValue);}).then(chain.filter(mutatedExchange));});}@Overridepublic int getOrder() {return HIGHEST_PRECEDENCE;}@Overridepublic Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {/*** save request path and serviceId into gateway context*/ServerHttpRequest request = exchange.getRequest();ServerHttpResponse response = exchange.getResponse();GatewayContext gatewayContext = new GatewayContext();String path = request.getPath().pathWithinApplication().value();gatewayContext.setPath(path);gatewayContext.getFormData().addAll(request.getQueryParams());gatewayContext.setIpAddress(String.valueOf(request.getRemoteAddress()));HttpHeaders headers = request.getHeaders();gatewayContext.setHeaders(headers);log.debug("HttpMethod:{},Url:{}", request.getMethod(), request.getURI().getRawPath());/// 注意，因为webflux的响应式编程 不能再采取原先的编码方式 即应该先将gatewayContext放入exchange中，否则其他地方可能取不到/*** save gateway context into exchange*/exchange.getAttributes().put(GatewayContext.CACHE_GATEWAY_CONTEXT, gatewayContext);// 处理参数MediaType contentType = headers.getContentType();long contentLength = headers.getContentLength();if (contentLength > 0) {if (MediaType.APPLICATION_JSON.equals(contentType) || MediaType.APPLICATION_JSON_UTF8.equals(contentType)) {return readBody(exchange, chain, gatewayContext);}if (MediaType.APPLICATION_FORM_URLENCODED.equals(contentType)) {return readFormData(exchange, chain, gatewayContext);}}log.debug("[GatewayContext]ContentType:{},Gateway context is set with {}", contentType, gatewayContext);return chain.filter(exchange);}
}三、 RSA实现对请求参数解密
1、修改yml文件，增加解密过滤器
2、RSA解密过滤器
import cn.hutool.core.util.StrUtil;
import com.example.gateway.common.CommonConstant;
import com.example.gateway.common.GatewayContext;
import com.example.gateway.utils.RSAUtils;
import lombok.extern.slf4j.Slf4j;
import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
import org.springframework.core.io.buffer.DataBuffer;
import org.springframework.core.io.buffer.DataBufferFactory;
import org.springframework.http.HttpHeaders;
import org.springframework.http.HttpMethod;
import org.springframework.http.HttpStatus;
import org.springframework.http.server.reactive.ServerHttpRequest;
import org.springframework.http.server.reactive.ServerHttpRequestDecorator;
import org.springframework.stereotype.Component;
import reactor.core.publisher.Flux;import java.security.interfaces.RSAPrivateKey;/*** @Author: meng* @Description: RSA实现对请求参数解密* @Date: 2023/4/6 15:20* @Version: 1.0*/
@Slf4j
@Component
public class RSADecryptResponseGatewayFilterFactory extends AbstractGatewayFilterFactory {@Overridepublic GatewayFilter apply(Object config) {return (exchange, chain) -> {ServerHttpRequest serverHttpRequest = exchange.getRequest();HttpHeaders header = serverHttpRequest.getHeaders();String decrypt = serverHttpRequest.getHeaders().getFirst("decrypt");if (!HttpMethod.POST.matches(serverHttpRequest.getMethodValue())) {return chain.filter(exchange);}byte[] decrypBytes;GatewayContext gatewayContext = exchange.getAttribute(GatewayContext.CACHE_GATEWAY_CONTEXT);if(StrUtil.isBlank(gatewayContext.getCacheBody())){return CommonConstant.buildResponse(exchange, HttpStatus.BAD_REQUEST.value(), "请求参数不能为空");}try {// 获取request bodyString requestBody = gatewayContext.getCacheBody();log.info("encryptMsg body :{}", requestBody);RSAPrivateKey privateKey = RSAUtils.getPrivateKey(CommonConstant.RSA_PRIVATE_KEY);String decryptMsg = RSAUtils.decryptByPrivateKey(requestBody, privateKey);log.info("decryptMsg body :{}", decryptMsg);gatewayContext.setCacheBody(decryptMsg);decrypBytes = decryptMsg.getBytes();} catch (Exception e) {log.error("RSA 解密失败:{}", e);return CommonConstant.buildResponse(exchange, HttpStatus.BAD_REQUEST.value(), "RSA解密失败");}// 根据解密后的参数重新构建请求DataBufferFactory dataBufferFactory = exchange.getResponse().bufferFactory();Flux<DataBuffer> bodyFlux = Flux.just(dataBufferFactory.wrap(decrypBytes));ServerHttpRequest newRequest = serverHttpRequest.mutate().uri(serverHttpRequest.getURI()).build();newRequest = new ServerHttpRequestDecorator(newRequest) {@Overridepublic Flux<DataBuffer> getBody() {return bodyFlux;}};// 构建新的请求头HttpHeaders headers = new HttpHeaders();headers.putAll(exchange.getRequest().getHeaders());// 由于修改了传递参数，需要重新设置CONTENT_LENGTH，长度是字节长度，不是字符串长度int length = decrypBytes.length;headers.remove(HttpHeaders.CONTENT_LENGTH);headers.setContentLength(length);newRequest = new ServerHttpRequestDecorator(newRequest) {@Overridepublic HttpHeaders getHeaders() {return headers;}};// 把解密后的数据重置到exchange自定义属性中,在之后的日志GlobalLogFilter从此处获取请求参数打印日志exchange.getAttributes().put(GatewayContext.CACHE_GATEWAY_CONTEXT, gatewayContext);return chain.filter(exchange.mutate().request(newRequest).build());};}}3、测试结果：
四、 RSA实现对返回结果加密
最简单的方法是使用gateway全局过滤器实现，但是我们有可能不需要对所有接口的结果进行加密，我们也可以使用局部过滤器实现。
实践过程中遇到一个问题，ServerHttpResponseDecorator不生效，是因为过滤器顺序问题。
全局过滤器：
自定义的GlobaFilter的order必须小于-1，否则标准 NettyWriteResponseFilter 将在过滤器有机会被调用之前发送响应。
相关讨论：https://github.com/spring-cloud/spring-cloud-gateway/issues/47
局部过滤器：
官方提供了一种方式，详细介绍：Spring Cloud Gateway
如果我们想使用yml+nacos实现动态路由的形式，我们可以借鉴原生类ModifyRequestBodyGatewayFilterFactory实现。
1、修改yml文件，增加加密过滤器
2、RSA加密过滤器
import cn.hutool.core.util.StrUtil;
import com.example.gateway.common.CommonConstant;
import com.example.gateway.utils.RSAUtils;
import lombok.extern.slf4j.Slf4j;
import org.reactivestreams.Publisher;
import org.springframework.cloud.gateway.filter.GatewayFilter;
import org.springframework.cloud.gateway.filter.GatewayFilterChain;
import org.springframework.cloud.gateway.filter.NettyWriteResponseFilter;
import org.springframework.cloud.gateway.filter.factory.AbstractGatewayFilterFactory;
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.http.HttpMethod;
import org.springframework.http.HttpStatus;
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.Charset;
import java.security.interfaces.RSAPrivateKey;/*** @Author: meng* @Description: RSA加密 - 借鉴原生类ModifyRequestBodyGatewayFilterFactory实现* https://docs.spring.io/spring-cloud-gateway/docs/current/reference/html/#the-modifyresponsebody-gatewayfilter-factory* @Date: 2023/4/3 11:37* @Version: 1.0*/
@Slf4j
@Component
public class RSAEncryptResponseGatewayFilterFactory extends AbstractGatewayFilterFactory {@Overridepublic GatewayFilter apply(Object config) {RewriteResponseGatewayFilter rewriteResponseGatewayFilter = new RewriteResponseGatewayFilter();return rewriteResponseGatewayFilter;}public class RewriteResponseGatewayFilter implements GatewayFilter, Ordered {@Overridepublic Mono<Void> filter(ServerWebExchange exchange, GatewayFilterChain chain) {if (!HttpMethod.POST.matches(exchange.getRequest().getMethodValue())) {return chain.filter(exchange);}ServerHttpResponse originalResponse = exchange.getResponse();DataBufferFactory bufferFactory = originalResponse.bufferFactory();ServerHttpResponseDecorator decoratedResponse = new ServerHttpResponseDecorator(originalResponse) {@Overridepublic Mono<Void> writeWith(Publisher<? extends DataBuffer> body) {if (body instanceof Flux) {Flux<? extends DataBuffer> fluxBody = (Flux<? extends DataBuffer>) body;return super.writeWith(fluxBody.map(dataBuffer -> {byte[] content = new byte[dataBuffer.readableByteCount()];dataBuffer.read(content);DataBufferUtils.release(dataBuffer);String responseStr = new String(content, Charset.forName(CommonConstant.UTF8));//RSA加密response值log.info("RSA response:{}", responseStr);byte[] newContent = new byte[0];try {RSAPrivateKey privateKey = RSAUtils.getPrivateKey(CommonConstant.RSA_PRIVATE_KEY);String encryptMsg = RSAUtils.encryptByPrivateKey(responseStr, privateKey);log.info("RSA encryptMsg:{}", encryptMsg);newContent = encryptMsg.getBytes(CommonConstant.UTF8);} catch (Exception e) {log.error("RSA fail:{}", e);throw new RuntimeException(e);}return bufferFactory.wrap(newContent);}));}return super.writeWith(body);}};return chain.filter(exchange.mutate().response(decoratedResponse).build());}@Overridepublic int getOrder() {return NettyWriteResponseFilter.WRITE_RESPONSE_FILTER_ORDER - 1;}}
}
3、测试结果
