SpringBoot接口加密解密统一处理

我们与客户端的接口交互中，为了更高的安全性，我们可能需要对接口加密（请求参数加密，服务端解密）、返回信息加密（服务端加密，客户端解密），但是也不是所有的接口都这样，有些接口可能不需要，我们可以使用注解来轻松达到此要求。

将接口参数的加密解密和返回信息的加密解密分开，分别定义注解，利用Controller的ControllerAdvice来拦截所有的请求，在其中判断是否需要加密解密，即可达到要求。

使用方法：使用 DecryptRequest 和 EncryptResponse 注解即可,可以放在Controller的类和方法上,其中一个为false就不执行了。像这样：

@RestController
@RequestMapping("/test")
//@DecryptRequest
@EncryptResponse
public class TestController {
  @Autowired
  @Qualifier("rrCrypto")
  private Crypto crypto;
 
  @DecryptRequest(false)
  @EncryptResponse(false)
  @RequestMapping(value = "/enc" , method = RequestMethod.POST)
  public String enc(@RequestBody String body){
    return crypto.encrypt(body);
  }
}

定义参数解密的注解，DecryptRequest。

@Target({ElementType.METHOD , ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@documented
public @interface DecryptRequest {
  
  boolean value() default true;
}

定义返回信息加密的注解，EncryptResponse。

@Target({ElementType.METHOD , ElementType.TYPE})
@Retention(RetentionPolicy.RUNTIME)
@documented
public @interface EncryptResponse {
  
  boolean value() default true;
}

这两个注解可以放在类和方法上，遵循一样的逻辑，即：类上的注解 && 方法上的注解，一方没有即为true，都为false为false。逻辑主要在 NeedCrypto 中。

class NeedCrypto {
  private NeedCrypto(){}
  
  static boolean needEncrypt(MethodParameter returnType) {
    boolean encrypt = false;
    boolean classPresentAnno = returnType.getContainingClass().isAnnotationPresent(EncryptResponse.class);
    boolean methodPresentAnno = returnType.getMethod().isAnnotationPresent(EncryptResponse.class);
 
    if(classPresentAnno){
      //类上标注的是否需要加密
      encrypt = returnType.getContainingClass().getAnnotation(EncryptResponse.class).value();
      //类不加密，所有都不加密
      if(!encrypt){
 return false;
      }
    }
    if(methodPresentAnno){
      //方法上标注的是否需要加密
      encrypt = returnType.getMethod().getAnnotation(EncryptResponse.class).value();
    }
    return encrypt;
  }
  
  static boolean needDecrypt(MethodParameter parameter) {
    boolean encrypt = false;
    boolean classPresentAnno = parameter.getContainingClass().isAnnotationPresent(DecryptRequest.class);
    boolean methodPresentAnno = parameter.getMethod().isAnnotationPresent(DecryptRequest.class);
 
    if(classPresentAnno){
      //类上标注的是否需要解密
      encrypt = parameter.getContainingClass().getAnnotation(DecryptRequest.class).value();
      //类不加密，所有都不加密
      if(!encrypt){
 return false;
      }
    }
    if(methodPresentAnno){
      //方法上标注的是否需要解密
      encrypt = parameter.getMethod().getAnnotation(DecryptRequest.class).value();
    }
    return encrypt;
  }
}

然后定义ControllerAdvice，对于请求解密的，定义 DecryptRequestBodyAdvice ，实现 RequestBodyAdvice 。

@ControllerAdvice
@ConditionalOnProperty(prefix = "spring.crypto.request.decrypt", name = "enabled" , havingValue = "true", matchIfMissing = true)
public class DecryptRequestBodyAdvice implements RequestBodyAdvice {
 
  @Value("${spring.crypto.request.decrypt.charset:UTF-8}")
  private String charset = "UTF-8";
 
  @Autowired
  @Qualifier("rrCrypto")
  private Crypto crypto;
 
 @Override
 public boolean supports(MethodParameter methodParameter, Type targetType,
  Class> converterType) {
 return true;
 }
 
 @Override
 public Object handleEmptyBody(Object body, HttpInputMessage inputMessage, MethodParameter parameter,
  Type targetType, Class> converterType) {
 return body;
 }
 
 @Override
 public HttpInputMessage beforeBodyRead(HttpInputMessage inputMessage, MethodParameter parameter, Type targetType,
  Class> converterType) throws IOException {
 if( NeedCrypto.needDecrypt(parameter) ){
      return new DecryptHttpInputMessage(inputMessage , charset , crypto);
 }
 return inputMessage;
 }
 
 @Override
 public Object afterBodyRead(Object body, HttpInputMessage inputMessage, MethodParameter parameter, Type targetType,
  Class> converterType) {
 return body;
 }
}

标上注解 ConditionalOnProperty 表示只有条件为true的时候才开启解密功能，一个配置即可打开或者关闭解密功能。真正的解密逻辑留给 DecryptHttpInputMessage ， 它又委托给 Crypto。

public class DecryptHttpInputMessage implements HttpInputMessage {
  private HttpInputMessage inputMessage;
  private String charset;
  private Crypto crypto;
 
  public DecryptHttpInputMessage(HttpInputMessage inputMessage, String charset , Crypto crypto) {
    this.inputMessage = inputMessage;
    this.charset = charset;
    this.crypto = crypto;
  }
 
  @Override
  public InputStream getBody() throws IOException {
    String content = IoUtil.read(inputMessage.getBody() , charset);
 
    String decryptBody = crypto.decrypt(content, charset);
 
    return new ByteArrayInputStream(decryptBody.getBytes(charset));
  }
 
  @Override
  public HttpHeaders getHeaders() {
    return inputMessage.getHeaders();
  }
}

对于返回值加密，定义 EncryptResponseBodyAdvice，实现 ResponseBodyAdvice。

@ControllerAdvice
@ConditionalOnProperty(prefix = "spring.crypto.response.encrypt", name = "enabled" , havingValue = "true", matchIfMissing = true)
public class EncryptResponseBodyAdvice implements ResponseBodyAdvice