如何在springboot項目中進行XSS過濾

簡單介紹

XSS : 跨站腳本攻擊(Cross Site Scripting)，為不和層疊樣式表(Cascading Style Sheets, CSS)的縮寫混淆，故將跨站腳本攻擊縮寫為XSS。惡意攻擊者往Web頁面里插入惡意html代碼，當用戶瀏覽該頁之時，嵌入其中Web里面的html代碼會被執行，從而達到惡意攻擊用戶的特殊目的。
過濾方式:主要通過對html標簽進行轉義的方式達到過濾的目的

話不多說,直接上代碼

實現方式,共分為三步:

第一步:在springboot啟動類上添加@ServletComponentScan注解,該注解會自動掃描到我們自定義的filter(還有其他方式,這里就不贅述了,大家有興趣的可以自行百度)

第二步:定義request的包裝類,重寫其中的關鍵方法

import com.alibaba.fastjson.JSON;
import org.apache.commons.text.StringEscapeUtils;
import javax.servlet.ReadListener;
import javax.servlet.ServletInputStream;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
import java.io.*;
import java.nio.charset.Charset;
import java.util.HashMap;
import java.util.Map;
/**
 * ServletRequest包裝類,對request做XSS過濾處理
 * @author Jozz
 */
public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {

    public XssHttpServletRequestWrapper(HttpServletRequest request) {
        super(request);
    }

    @Override
    public String getHeader(String name) {
        return StringEscapeUtils.escapeHtml4(super.getHeader(name));
    }

    @Override
    public String getQueryString() {
        return StringEscapeUtils.escapeHtml4(super.getQueryString());
    }

    @Override
    public String getParameter(String name) {
        return StringEscapeUtils.escapeHtml4(super.getParameter(name));
    }

    @Override
    public String[] getParameterValues(String name) {
        String[] values = super.getParameterValues(name);
        if(values != null) {
            int length = values.length;
            String[] escapseValues = new String[length];
            for(int i = 0; i < length; i++){
                escapseValues[i] = StringEscapeUtils.escapeHtml4(values[i]);
            }
            return escapseValues;
        }
        return values;
    }

    @Override
    public ServletInputStream getInputStream() throws IOException {
        String str=getRequestBody(super.getInputStream());
        Map<String,Object> map= JSON.parseObject(str,Map.class);
        Map<String,Object> resultMap=new HashMap<>(map.size());
        for(String key:map.keySet()){
            Object val=map.get(key);
            if(map.get(key) instanceof String){
                resultMap.put(key,StringEscapeUtils.escapeHtml4(val.toString()));
            }else{
                resultMap.put(key,val);
            }
        }
        str=JSON.toJSONString(resultMap);
        final ByteArrayInputStream bais = new ByteArrayInputStream(str.getBytes());
        return new ServletInputStream() {
            @Override
            public int read() throws IOException {
                return bais.read();
            }
            @Override
            public boolean isFinished() {
                return false;
            }
            @Override
            public boolean isReady() {
                return false;
            }
            @Override
            public void setReadListener(ReadListener listener) {
            }
        };
    }

    private String getRequestBody(InputStream stream) {
        String line = "";
        StringBuilder body = new StringBuilder();
        int counter = 0;

        // 讀取POST提交的數據內容
        BufferedReader reader = new BufferedReader(new InputStreamReader(stream, Charset.forName("UTF-8")));
        try {
            while ((line = reader.readLine()) != null) {
                body.append(line);
                counter++;
            }
        } catch (IOException e) {
            e.printStackTrace();
        }
        return body.toString();
    }
}

其中的StringEscapeUtils來自:

    compile("org.apache.commons:commons-text:1.6")

第三步:自定義過濾器

import javax.servlet.*;
import javax.servlet.annotation.WebFilter;
import javax.servlet.http.HttpServletRequest;
import java.io.IOException;
/**
 * XSS過濾器
 * @author Jozz
 */
@WebFilter(filterName="xssFilter",urlPatterns="/*")
public class XssFilter implements Filter {

    @Override
    public void init(javax.servlet.FilterConfig filterConfig) throws ServletException {

    }

    @Override
    public void doFilter(ServletRequest servletRequest, ServletResponse servletResponse, FilterChain filterChain) throws IOException, ServletException {
        HttpServletRequest request = (HttpServletRequest)servletRequest;
        String path = request.getServletPath();
        //由於我的@WebFilter注解配置的是urlPatterns="/*"(過濾所有請求),所以這里對不需要過濾的靜態資源url,作忽略處理(大家可以依照具體需求配置)
        String[] exclusionsUrls = {".js",".gif",".jpg",".png",".css",".ico"};
        for (String str : exclusionsUrls) {
            if (path.contains(str)) {
                filterChain.doFilter(servletRequest,servletResponse);
                return;
            }
        }
        filterChain.doFilter(new XssHttpServletRequestWrapper(request),servletResponse);
    }

    @Override
    public void destroy() {

    }
}

到這里就大功告成了~若您覺得文章有用，歡迎點贊分享！