springboot中使用过滤器,jsoup过滤XSS脚本详解
springboot使用过滤器,jsoup过滤XSS脚本
- 背景:略
- 目标:完成request请求中的脚本过滤
- 技术:filter,jsoup,requestWapper
1.把可能包含脚本的参数位置分析一下
post
/put
/delete
: 请求的参数中,有可能是表单提交、也有可能是使用了@requestBody注解,那么参数就是json格式,位于request的流中。get
/options
等:可能存在于url参数中,也有可能是表单提交的预请求中,所以一般在能想到的位置都有可能存在,包括header中。
2.分析实现过程
2.1首先要从request请求中将各个需要过滤位置的参数取出来
2.2然后将参数取出来进行过滤
2.3将过滤后的参数重新包装成request传递下去
2.4在这期间,
- 需要准备好jsoup过滤脚本的工具类;
- 需要自定义一个过滤器,并且在过滤器中添加匹配条件,如:那些url不需要过滤,那些请求方式必须进行过滤;
- 对过滤器进行配置,是否开启,设置在整个过滤器链中的位置,设置过滤的白名单或者黑名单
- 所以就很清晰了我们过滤需要哪些类,哪些配置了
一个filter
一个requestWapper
一个jsoup工具类
一个filter的配置类
2.5进行数据测试
3.代码实现过程
3.1.jsoup依赖:
<!--screen xss -->
<dependency>
<groupId>org.jsoup</groupId>
<artifactId>jsoup</artifactId>
<version>1.9.2</version>
</dependency>
3.2jsoup工具类:JsoupUtil
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.safety.Whitelist;
import java.io.FileNotFoundException;
import java.io.IOException;
/**
* @Auther: qianshanmuxue
* @Date: 2019/2/27 19:32
* @Description: xss Illegal label filtering
*/
public class JsoupUtil {
private static final Whitelist whitelist = Whitelist.simpleText();//jsoup白名单种类,有四种,每一种针对的标签类型不一样,具体的可以ctrl+左键点击simpleText,在jsoup源码中有响应的注释和标签名单
//add myself white list label
private static final Document.OutputSettings outputSettings = new Document.OutputSettings().prettyPrint(false);
static {
whitelist.addAttributes(":all", "style").addTags("p").addTags("span");//将自定义标签添加进白名单,除开白名单之外的标签都会被过滤
whitelist.preserveRelativeLinks(true);//这个配置的意思的过滤如果找不到成对的标签,就只过滤单个标签,而不用把后面所有的文本都进行过滤。
//(之前在这个问题上折腾了很久,当<script>标签只有一个时,会<script>标签后面的数据全部过滤)
}
public static String clean(String content) { //过滤方法
return Jsoup.clean(content, "", whitelist, outputSettings);
}
//test main
public static void main(String[] args) throws FileNotFoundException, IOException {
String text = "<a href=\"http://www.baidu.com/a\" onclick=\"alert(1);\"><span><p>sss</p></span></a><script>alert(0);</script>sss";
System.out.println(clean(text));
}
}
3.3request包装类XssHttpServletRequestWrapper
import java.io.*;
import java.util.*;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import com.xxx.utils.JsoupUtil;
import org.jsoup.nodes.Document;
import org.springframework.util.StringUtils;
/**
* @Auther: qianshanmuxue
* @Date: 2019/2/27 16:24
* @Description:request wapper use to get request parameter and request bdoy data and wapper another request
*/
public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper { //因为我们需要获取request中的数据,所以需要继承java底层中HttpServletRequestWrapper这个类,重写父类中的某些方法,获取相应位置的参数
private HttpServletRequest orgRequest = null;
private static final Document.OutputSettings outputSettings = new Document.OutputSettings().prettyPrint(false);
public XssHttpServletRequestWrapper(HttpServletRequest request) {
super(request);
orgRequest = request;
}
@Override
public ServletInputStream getInputStream() throws IOException {//get
BufferedReader br = new BufferedReader(new InputStreamReader(orgRequest.getInputStream()));
String line = br.readLine();
String result = "";
if (line != null) {
result += clean(line);
}
return new WrappedServletInputStream(new ByteArrayInputStream(result.getBytes()));
}
@Override
public String getParameter(String name) {
if (("content".equals(name) || name.endsWith("WithHtml"))) {
return super.getParameter(name);
}
name = clean(name);
String value = super.getParameter(name);
if (!StringUtils.isEmpty(value)) {
value = clean(value);
}
return value;
}
@Override
public Map getParameterMap() {
Map map = super.getParameterMap();
// 返回值Map
Map<String, String> returnMap = new HashMap<String, String>();
Iterator entries = map.entrySet().iterator();
Map.Entry entry;
String name = "";
String value = "";
while (entries.hasNext()) {
entry = (Map.Entry) entries.next();
name = (String) entry.getKey();
Object valueObj = entry.getValue();
if (null == valueObj) {
value = "";
} else if (valueObj instanceof String[]) {
String[] values = (String[]) valueObj;
for (int i = 0; i < values.length; i++) {
value = values[i] + ",";
}
value = value.substring(0, value.length() - 1);
} else {
value = valueObj.toString();
}
returnMap.put(name, clean(value).trim());
}
return returnMap;
}
@Override
public String[] getParameterValues(String name) {
String[] arr = super.getParameterValues(name);
if (arr != null) {
for (int i = 0; i < arr.length; i++) {
arr[i] = clean(arr[i]);
}
}
return arr;
}
/**
* get org request
*
* @return
*/
public HttpServletRequest getOrgRequest() {
return orgRequest;
}
/**
* wapper request
*/
public static HttpServletRequest getOrgRequest(HttpServletRequest req) {
if (req instanceof XssHttpServletRequestWrapper) {
return ((XssHttpServletRequestWrapper) req).getOrgRequest();
}
return req;
}
public String clean(String content) {
String result = JsoupUtil.clean(content);
return result;
}
private class WrappedServletInputStream extends ServletInputStream {
public void setStream(InputStream stream) {
this.stream = stream;
}
private InputStream stream;
public WrappedServletInputStream(InputStream stream) {
this.stream = stream;
}
@Override
public int read() throws IOException {
return stream.read();
}
@Override
public boolean isFinished() {
return true;
}
@Override
public boolean isReady() {
return true;
}
@Override
public void setReadListener(ReadListener readListener) {
}
}
}
3.4filter-XssFilter
import org.apache.commons.lang.BooleanUtils;
import org.apache.commons.lang.StringUtils;
import java.io.IOException;
import java.util.ArrayList;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;
import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
/**
* @Auther: qianshanmuxue
* @Date: 2019/2/27 16:25
* @Description:
*/
//@WebFilter
//@Component 在这里可以不用这个注解,以为后面我们会在config中去配置这个filter,在这里只需要实现 Filter 接口实现相应的方法就ok
public class XssFilter implements Filter {
private static boolean IS_INCLUDE_RICH_TEXT = false;//用于接收配置中的参数,决定这个过滤器是否开启
public List<String> excludes = new ArrayList<String>();//用于接收配置中的参数,决定哪些是不需要过滤的url(在这里,也可以修改handleExcludeURL()方法中相应的代码,使其变更为只需要过滤的url)
@Override
public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain)
throws IOException, ServletException {
HttpServletRequest req = (HttpServletRequest) request;
HttpServletResponse resp = (HttpServletResponse) response;
if (handleExcludeURL(req, resp)) {
chain.doFilter(request, response);
return;
}
XssHttpServletRequestWrapper xssRequest = new XssHttpServletRequestWrapper((HttpServletRequest) request);
chain.doFilter(xssRequest, response);
}
/**
*此方法是决定对当前url是否执行过滤,
*在这里没有使用请求方法(post/put)来匹配,因为在本项目中使用url匹配更适合(因为get和其他请求方式也需要进行过滤),如果你有兴趣可以把这个方法更改为匹配请求方法进行过滤
**/
private boolean handleExcludeURL(HttpServletRequest request, HttpServletResponse response) {
if ((excludes == null || excludes.isEmpty())&&IS_INCLUDE_RICH_TEXT) {
return false;
}
String url = request.getServletPath();
for (String pattern : excludes) {
Pattern p = Pattern.compile("^" + pattern);
Matcher m = p.matcher(url);
if (m.find()) {
return true;
}
}
return false;
}
/**
*过滤器初始化,从配置类中获取参数,用于初始化两个参数(是否开启,排除指定的url list)
*
*/
@Override
public void init(FilterConfig arg0) throws ServletException {
String isIncludeRichText = arg0.getInitParameter("isIncludeRichText");
if (StringUtils.isNotBlank(isIncludeRichText)) {
IS_INCLUDE_RICH_TEXT = BooleanUtils.toBoolean(isIncludeRichText);
}
String temp = arg0.getInitParameter("excludes");
if (temp != null) {
String[] url = temp.split(",");
for (int i = 0; url != null && i < url.length; i++) {
excludes.add(url[i]);
}
}
}
@Override
public void destroy() {
}
}
3.5filter的配置类:XssConfig
import com.xxx.filter.XssFilter;
import com.google.common.collect.Maps;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;
import java.util.Map;
/**
* @Auther: qianshanmuxue
* @Date: 2019/2/27 16:49
* @Description: xss filter config
*/
@Configuration
public class XssConfig {
@Bean
public FilterRegistrationBean xssFilterRegistrationBean() {
FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
filterRegistrationBean.setFilter(new XssFilter());
filterRegistrationBean.setOrder(1);//filter order ,set it first
filterRegistrationBean.setEnabled(true);
filterRegistrationBean.addUrlPatterns("/*"); //set filter all url mapping
Map<String, String> initParameters = Maps.newHashMap();
initParameters.put("excludes", "/oauth/token");///white list url
initParameters.put("isIncludeRichText", "true");//enable or disable
filterRegistrationBean.setInitParameters(initParameters);
return filterRegistrationBean;
}
}
调试截图:
请求:
程序截图:
运行结果:
可以看到body中 的脚本已经被过滤了,
然后其他的截图我就不发了,还有一种思路就是在过滤器中把字符转义。
感谢luckpet大佬的提示
1 BufferedReader 使用完需要关闭 ;
2 对于一些拿postman等工具的朋友,拼接json的话会有换行 这里result += clean(line); 需要改成: while((line = br.readLine()) != null){ if (line != null) { result += line; } }
使用jsoup防止XSS攻击
前阵子项目国测后,打开一个项目页面,莫名其妙弹出xss,搜了全局也没找到alert("xss"),问了一下项目经理,原来是国测做防注入的时候,在添加数据的时候做的,一脸懵逼。
查了一下资料,以前做项目的时候都没想到这个问题,如果保存一段script脚本,查数据的时候,这段脚本就会被执行,这东西后果挺严重啊,如果是在桌面外弹框,执行个挖矿脚本,这玩意不得了啊,厉害,长知识了。。。
<dependency>
<groupId>org.jsoup</groupId>
<artifactId>jsoup</artifactId>
<version>1.11.3</version>
</dependency>
以上为个人经验,希望能给大家一个参考,也希望大家多多支持。
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