如何在Spring中拦截RequestRejectedException？

Question

我在Tomcat日志中看到大量RequestRejectedException条目（示例粘贴在下面）。在几个月前的一次小版本升级（Spring Security 4.2.4，IIRC)后，这些功能开始出现在我的日志文件中，因此这显然是Spring中默认启用的一个新的安全特性。这里报告了一个类似的问题，但我的问题具体涉及如何在控制器中拦截这些异常。这个问题有一个Spring Securitybug（提供一种处理RequestRejectedException的方法）。然而，他们直到Spring5.1才会针对这个问题进行修复。

我理解引发这些异常的原因，并且我不想禁用此安全功能。

null

Aug 10, 2018 2:01:36 PM org.apache.catalina.core.StandardWrapperValve invoke
SEVERE: Servlet.service() for servlet [dispatcher] in context with path [] threw exception
org.springframework.security.web.firewall.RequestRejectedException: The request was rejected because the URL contained a potentially malicious String ";"
        at org.springframework.security.web.firewall.StrictHttpFirewall.rejectedBlacklistedUrls(StrictHttpFirewall.java:265)
        at org.springframework.security.web.firewall.StrictHttpFirewall.getFirewalledRequest(StrictHttpFirewall.java:245)
        at org.springframework.security.web.FilterChainProxy.doFilterInternal(FilterChainProxy.java:193)
        at org.springframework.security.web.FilterChainProxy.doFilter(FilterChainProxy.java:177)
        at org.springframework.web.filter.DelegatingFilterProxy.invokeDelegate(DelegatingFilterProxy.java:347)
        at org.springframework.web.filter.DelegatingFilterProxy.doFilter(DelegatingFilterProxy.java:263)
        at org.apache.catalina.core.ApplicationFilterChain.internalDoFilter(ApplicationFilterChain.java:193)
        at org.apache.catalina.core.ApplicationFilterChain.doFilter(ApplicationFilterChain.java:166)
        at org.apache.catalina.core.StandardWrapperValve.invoke(StandardWrapperValve.java:198)
        at org.apache.catalina.core.StandardContextValve.invoke(StandardContextValve.java:96)
        at org.apache.catalina.authenticator.AuthenticatorBase.invoke(AuthenticatorBase.java:496)
        at org.apache.catalina.core.StandardHostValve.invoke(StandardHostValve.java:140)
        at org.apache.catalina.valves.ErrorReportValve.invoke(ErrorReportValve.java:81)
        at org.apache.catalina.core.StandardEngineValve.invoke(StandardEngineValve.java:87)
        at org.apache.catalina.connector.CoyoteAdapter.service(CoyoteAdapter.java:342)
        at org.apache.coyote.ajp.AjpProcessor.service(AjpProcessor.java:486)
        at org.apache.coyote.AbstractProcessorLight.process(AbstractProcessorLight.java:66)
        at org.apache.coyote.AbstractProtocol$ConnectionHandler.process(AbstractProtocol.java:790)
        at org.apache.tomcat.util.net.NioEndpoint$SocketProcessor.doRun(NioEndpoint.java:1459)
        at org.apache.tomcat.util.net.SocketProcessorBase.run(SocketProcessorBase.java:49)
        at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
        at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
        at org.apache.tomcat.util.threads.TaskThread$WrappingRunnable.run(TaskThread.java:61)
        at java.lang.Thread.run(Thread.java:748)

在两天的时间里，我看到了超过3,200个这样的问题，它很快成为我的catalina.out日志文件的最大贡献者，以至于它阻止了我看到其他合法的问题。从本质上讲，这个新的Spring Security特性是一种内置拒绝服务的形式，自4月份以来，它已经浪费了我几个小时的时间。我并不是说它不是一个重要的特性，只是说默认实现完全搞砸了，我想找到一种方法来控制它，无论是作为开发人员还是系统管理员。

在Spring中，我使用一个自定义错误控制器来拦截许多其他异常类型（包括IOException)。但是，RequestRejectedException似乎由于某种原因而失败。

这是我的errorcontroller.java的相关部分，以提供我试图完成的任务：

@ControllerAdvice
public final class ErrorController
{
    /**
     * Logger.
     */
    private static final Logger LOGGER = Logger.getLogger(ErrorController.class.getName());

    /**
     * Generates an Error page by intercepting exceptions generated from HttpFirewall.
     *
     * @param ex A RequestRejectedException exception.
     * @return The tile definition name for the page.
     */
    @ExceptionHandler(RequestRejectedException.class)
    @ResponseStatus(HttpStatus.BAD_REQUEST)
    public String handleRequestRejectedException(final HttpServletRequest request, final RequestRejectedException ex)
    {
        if (LOGGER.isLoggable(Level.INFO))
        {
            LOGGER.log(Level.INFO, "Request Rejected", ex);
        }

        LOGGER.log(Level.WARNING, "Rejected request for [" + request.getRequestURL().toString() + "]. Reason: " + ex.getMessage());
        return "errorPage";
    }

    /**
     * Generates a Server Error page.
     *
     * @param ex An exception.
     * @return The tile definition name for the page.
     */
    @ExceptionHandler(Exception.class)
    @ResponseStatus(HttpStatus.INTERNAL_SERVER_ERROR)
    public String handleException(final Exception ex)
    {
        if (LOGGER.isLoggable(Level.SEVERE))
        {
            LOGGER.log(Level.SEVERE, "Server Error", ex);
        }

        return "errorPage";
    }
}

Aug 05, 2018 7:50:30 AM com.mycompany.spring.controller.ErrorController handleException
SEVERE: Server Error
java.lang.IllegalStateException: Cannot create a session after the response has been committed
        at org.apache.catalina.connector.Request.doGetSession(Request.java:2999)
...

如何在错误控制器中拦截RequestRejectedException？

Answer 1

也可以通过一个简单的过滤器来处理，这将导致404错误响应

@Component
@Slf4j
@Order(Ordered.HIGHEST_PRECEDENCE)
public class LogAndSuppressRequestRejectedExceptionFilter extends GenericFilterBean {

    @Override
    public void doFilter(ServletRequest req, ServletResponse res, FilterChain chain) throws IOException, ServletException {
        try {
            chain.doFilter(req, res);
        } catch (RequestRejectedException e) {
            HttpServletRequest request = (HttpServletRequest) req;
            HttpServletResponse response = (HttpServletResponse) res;

            log
                .warn(
                        "request_rejected: remote={}, user_agent={}, request_url={}",
                        request.getRemoteHost(),  
                        request.getHeader(HttpHeaders.USER_AGENT),
                        request.getRequestURL(), 
                        e
                );

            response.sendError(HttpServletResponse.SC_NOT_FOUND);
        }
    }
}