springboot中使用過濾器,jsoup過濾XSS腳本詳解
springboot使用過濾器,jsoup過濾XSS腳本
- 背景:略
- 目標:完成request請求中的腳本過濾
- 技術:filter,jsoup,requestWapper
1.把可能包含腳本的參數位置分析一下
post
/put
/delete
: 請求的參數中,有可能是表單提交、也有可能是使用瞭@requestBody註解,那麼參數就是json格式,位於request的流中。get
/options
等:可能存在於url參數中,也有可能是表單提交的預請求中,所以一般在能想到的位置都有可能存在,包括header中。
2.分析實現過程
2.1首先要從request請求中將各個需要過濾位置的參數取出來
2.2然後將參數取出來進行過濾
2.3將過濾後的參數重新包裝成request傳遞下去
2.4在這期間,
- 需要準備好jsoup過濾腳本的工具類;
- 需要自定義一個過濾器,並且在過濾器中添加匹配條件,如:那些url不需要過濾,那些請求方式必須進行過濾;
- 對過濾器進行配置,是否開啟,設置在整個過濾器鏈中的位置,設置過濾的白名單或者黑名單
- 所以就很清晰瞭我們過濾需要哪些類,哪些配置瞭
一個filter
一個requestWapper
一個jsoup工具類
一個filter的配置類
2.5進行數據測試
3.代碼實現過程
3.1.jsoup依賴:
<!--screen xss --> <dependency> <groupId>org.jsoup</groupId> <artifactId>jsoup</artifactId> <version>1.9.2</version> </dependency>
3.2jsoup工具類: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白名單種類,有四種,每一種針對的標簽類型不一樣,具體的可以ctrl+左鍵點擊simpleText,在jsoup源碼中有響應的註釋和標簽名單 //add myself white list label private static final Document.OutputSettings outputSettings = new Document.OutputSettings().prettyPrint(false); static { whitelist.addAttributes(":all", "style").addTags("p").addTags("strong");//將自定義標簽添加進白名單,除開白名單之外的標簽都會被過濾 whitelist.preserveRelativeLinks(true);//這個配置的意思的過濾如果找不到成對的標簽,就隻過濾單個標簽,而不用把後面所有的文本都進行過濾。 //(之前在這個問題上折騰瞭很久,當<script>標簽隻有一個時,會<script>標簽後面的數據全部過濾) } public static String clean(String content) { //過濾方法 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);\"><strong><p>sss</p></strong></a><script>alert(0);</script>sss"; System.out.println(clean(text)); } }
3.3request包裝類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 { //因為我們需要獲取request中的數據,所以需要繼承java底層中HttpServletRequestWrapper這個類,重寫父類中的某些方法,獲取相應位置的參數 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 在這裡可以不用這個註解,以為後面我們會在config中去配置這個filter,在這裡隻需要實現 Filter 接口實現相應的方法就ok public class XssFilter implements Filter { private static boolean IS_INCLUDE_RICH_TEXT = false;//用於接收配置中的參數,決定這個過濾器是否開啟 public List<String> excludes = new ArrayList<String>();//用於接收配置中的參數,決定哪些是不需要過濾的url(在這裡,也可以修改handleExcludeURL()方法中相應的代碼,使其變更為隻需要過濾的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); } /** *此方法是決定對當前url是否執行過濾, *在這裡沒有使用請求方法(post/put)來匹配,因為在本項目中使用url匹配更適合(因為get和其他請求方式也需要進行過濾),如果你有興趣可以把這個方法更改為匹配請求方法進行過濾 **/ 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; } /** *過濾器初始化,從配置類中獲取參數,用於初始化兩個參數(是否開啟,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的配置類: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; } }
調試截圖:
請求:
程序截圖:
運行結果:
可以看到body中 的腳本已經被過濾瞭,
然後其他的截圖我就不發瞭,還有一種思路就是在過濾器中把字符轉義。
感謝luckpet大佬的提示
1 BufferedReader 使用完需要關閉 ;
2 對於一些拿postman等工具的朋友,拼接json的話會有換行 這裡result += clean(line); 需要改成: while((line = br.readLine()) != null){ if (line != null) { result += line; } }
使用jsoup防止XSS攻擊
前陣子項目國測後,打開一個項目頁面,莫名其妙彈出xss,搜瞭全局也沒找到alert(“xss”),問瞭一下項目經理,原來是國測做防註入的時候,在添加數據的時候做的,一臉懵逼。
查瞭一下資料,以前做項目的時候都沒想到這個問題,如果保存一段script腳本,查數據的時候,這段腳本就會被執行,這東西後果挺嚴重啊,如果是在桌面外彈框,執行個挖礦腳本,這玩意不得瞭啊,厲害,長知識瞭。。。
<dependency> <groupId>org.jsoup</groupId> <artifactId>jsoup</artifactId> <version>1.11.3</version> </dependency>
以上為個人經驗,希望能給大傢一個參考,也希望大傢多多支持WalkonNet。
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