XSS漏洞解决方案之一：过滤器

一：web.xml文件

 

<!-- 解决xss漏洞 -->
  < filter >
    < filter-name >xssFilter</ filter-name >
     < filter-class >com.baidu.rigel.sandbox.core.filter.XSSFilter</ filter-class >
  </ filter >

  <!-- 解决xss漏洞 -->
  < filter-mapping >
    < filter-name >xssFilter</ filter-name >
    < url-pattern >/*</ url-pattern >
  </ filter-mapping >

  <!-- 解决xss漏洞 -->
  < filter >
    < filter-name >xssFilter</ filter-name >
     < filter-class >com.baidu.rigel.sandbox.core.filter.XSSFilter</ filter-class >
  </ filter >

  <!-- 解决xss漏洞 -->
  < filter-mapping >
    < filter-name >xssFilter</ filter-name >
    < url-pattern >/*</ url-pattern >
  </ filter-mapping >

 

 

 

 

 

二：过滤器:XSSFilter.java

 

 

 

package com.rigel.sandbox.core.filter;

import java.io.IOException;

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 com.rigel.sandbox.core.util.XssHttpServletRequestWrapper;

public class XSSFilter implements Filter {

    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
    }

    @Override
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException {

        XssHttpServletRequestWrapper xssRequest = new XssHttpServletRequestWrapper(
                (HttpServletRequest) request);
        chain.doFilter(xssRequest, response);
    }

    @Override
    public void destroy() {
    }

}

package com.rigel.sandbox.core.filter;

import java.io.IOException;

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 com.rigel.sandbox.core.util.XssHttpServletRequestWrapper;

public class XSSFilter implements Filter {

@Override
public void init(FilterConfig filterConfig) throws ServletException {
}

@Override
public void doFilter(ServletRequest request, ServletResponse response,
FilterChain chain) throws IOException, ServletException {

XssHttpServletRequestWrapper xssRequest = new XssHttpServletRequestWrapper(
(HttpServletRequest) request);
chain.doFilter(xssRequest, response);
}

@Override
public void destroy() {
}

}

 

 

 

 

 

 

 

 

三：包装器：XssHttpServletRequestWrapper.java

 

package com.rigel.sandbox.core.util;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;

public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {
    HttpServletRequest orgRequest = null ;

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

    /**
     * 覆盖getParameter方法，将参数名和参数值都做xss过滤。<br/>
     * 如果需要获得原始的值，则通过super.getParameterValues(name)来获取<br/>
     * getParameterNames,getParameterValues和getParameterMap也可能需要覆盖
     */
    @Override
    public String getParameter(String name) {
        String value = super .getParameter(xssEncode(name));
        if (value != null ) {
            value = xssEncode(value);
        }
        return value;
    }

    /**
     * 覆盖getHeader方法，将参数名和参数值都做xss过滤。<br/>
     * 如果需要获得原始的值，则通过super.getHeaders(name)来获取<br/>
     * getHeaderNames 也可能需要覆盖
     */
    @Override
    public String getHeader(String name) {

        String value = super .getHeader(xssEncode(name));
        if (value != null ) {
            value = xssEncode(value);
        }
        return value;
    }

    /**
     * 将容易引起xss漏洞的半角字符直接替换成全角字符
     *
     * @param s
     * @return
     */
    private static String xssEncode(String s) {
        if (s == null || s.isEmpty()) {
            return s;
        }
        StringBuilder sb = new StringBuilder(s.length() + 16 );
        for ( int i = 0 ; i < s.length(); i++) {
            char c = s.charAt(i);
            switch (c) {
            case '>' :
                sb.append( ">" ); // 转义大于号
                break ;
            case '<' :
                sb.append( "<" ); // 转义小于号
                break ;
            case '\'' :
                sb.append( "'" ); // 转义单引号
                break ;
            case '\"' :
                sb.append( "" "); // 转义双引号
                break ;
            case '&' :
                sb.append( "&" ); // 转义&
                break ;
            default :
                sb.append(c);
                break ;
            }
        }
        return sb.toString();
    }

    /**
     * 获取最原始的request
     *
     * @return
     */
    public HttpServletRequest getOrgRequest() {
        return orgRequest;
    }

    /**
     * 获取最原始的request的静态方法
     *
     * @return
     */
    public static HttpServletRequest getOrgRequest(HttpServletRequest req) {
        if (req instanceof XssHttpServletRequestWrapper) {
            return ((XssHttpServletRequestWrapper) req).getOrgRequest();
        }

        return req;
    }
}

 原文地址：http://www.2cto.com/Article/201309/247100.html