七、在拦截器中进行XSS与SQL注入拦截

cn華少

发布于 2019-11-07 12:30:59

1.3K0

发布于 2019-11-07 12:30:59

文章被收录于专栏：IT综合技术分享IT综合技术分享

本次开发环境为：

系统：Windows 10 10.0

JDK：JRE: 1.8.0_152-release-1136-b43 amd64 JVM: OpenJDK 64-Bit Server VM by JetBrains s.r.o

开发工具：IntelliJ IDEA 2018.1.8

springboot框架：2.2.0

直接上干货，不多废话，相关问题欢迎在评论区指教。

1、首先准备本次会用到的相关jar包，在pom.xml中导入

        <!-- xss过滤组件 -->
        <dependency>
            <groupId>org.jsoup</groupId>
            <artifactId>jsoup</artifactId>
            <version>1.12.1</version>
        </dependency>
        <!-- StringUtil工具类-->
        <dependency>
            <groupId>org.apache.commons</groupId>
            <artifactId>commons-lang3</artifactId>
            <version>3.9</version>
        </dependency>

2、开始制作一个字符串过滤工具，使其所有字符串都能按照相同规则进行过滤

import org.apache.commons.lang3.StringUtils;
import org.jsoup.Jsoup;
import org.jsoup.nodes.Document;
import org.jsoup.safety.Whitelist;

/**
 * 类 {@code FilterCoreUtil} 用于Xss非法标签过滤工具类 <br> 过滤html中的xss字符.
 *
 * 本软件仅对本次教程负责，版权所有 <a href="http://www.cnhuashao.com">中国，華少</a><br>
 *
 * @author cnHuaShao
 * <a href="mailto:lz2392504@gmail.com
 * <p>
 * ">cnHuaShao</a>
 * 修改备注：
 * @version v1.0.1 2019/11/5 19:42
 */
public class FilterCoreUtil {

    /**
     * 使用自带的basicWithImages 白名单
     * 允许的便签有a,b,blockquote,br,cite,code,dd,dl,dt,em,i,li,ol,p,pre,q,small,span,
     * strike,strong,sub,sup,u,ul,img
     * 以及a标签的href,img标签的src,align,alt,height,width,title属性
     */
    private static final Whitelist WHITE_LIST = Whitelist.basicWithImages();
    /** 配置过滤化参数,不对代码进行格式化 */
    private static final Document.OutputSettings OUTPUT_SETTINGS = new Document.OutputSettings().prettyPrint(false);
    static {
        // 富文本编辑时一些样式是使用style来进行实现的
        // 比如红色字体 style="color:red;"
        // 所以需要给所有标签添加style属性
        WHITE_LIST.addAttributes(":all", "style");
    }

    /**
     * 过滤主方法入口
     * @param content 需要过滤的字符串
     * @return 过滤后的字符串
     */
    public static String clean(String content) {
        if(StringUtils.isNotBlank(content)){
            content = content.trim();
        }
        return Jsoup.clean(content, "", WHITE_LIST, OUTPUT_SETTINGS);
    }
}

3、工具准备完毕，开始进行搭建一个仓库，用于处理所有的请求相关字符串

import com.cnhuashao.rapiddevelopment.core.demo4.util.FilterCoreUtil;
import org.apache.commons.lang3.StringUtils;

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

/**
 * 类 {@code XssHttpServletRequestWrapper} Xss核心匹配类 <br> .
 *
 * 本软件仅对本次教程负责，版权所有 <a href="http://www.cnhuashao.com">中国，華少</a><br>
 *
 * @author cnHuaShao
 * <a href="mailto:lz2392504@gmail.com
 * <p>
 * ">cnHuaShao</a>
 * 修改备注：
 * @version v1.0.1 2019/11/5 19:30
 */
public class XssHttpServletRequestWrapper extends HttpServletRequestWrapper {
    /**
     * 需要进行过滤的请求
     */
    HttpServletRequest orgRequest = null;
    /**
     * 是否启用过滤
     */
    private boolean isIncludeRichText = false;

    /**
     * 深度过滤构造方法
     * @param request 需要过滤的请求
     * @param isIncludeRichText 是否进行过滤，默认false
     */
    public XssHttpServletRequestWrapper(HttpServletRequest request, boolean isIncludeRichText) {
        super(request);
        orgRequest = request;
        this.isIncludeRichText = isIncludeRichText;
    }

    /**
     * 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) {
        Boolean flag = ("content".equals(name) || name.endsWith("WithHtml"));
        if( flag && !isIncludeRichText){
            return super.getParameter(name);
        }
        name = FilterCoreUtil.clean(name);
        String value = super.getParameter(name);
        if (StringUtils.isNotBlank(value)) {
            value = FilterCoreUtil.clean(value);
        }
        return value;
    }

    @Override
    public String[] getParameterValues(String name) {
        String[] arr = super.getParameterValues(name);
        if(arr != null){
            for (int i=0;i<arr.length;i++) {
                arr[i] = FilterCoreUtil.clean(arr[i]);
            }
        }
        return arr;
    }


    /**
     * 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) {
        name = FilterCoreUtil.clean(name);
        String value = super.getHeader(name);
        if (StringUtils.isNotBlank(value)) {
            value = FilterCoreUtil.clean(value);
        }
        return value;
    }

    /**
     * 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;
    }
}

4、Xss处理仓库均准备妥当，下面就可以开始编写统一的拦截器了

import org.apache.commons.lang3.BooleanUtils;
import org.apache.commons.lang3.StringUtils;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.*;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * 类 {@code XssFilter} Xss防止注入拦截器 <br> 用于过滤web请求中关于xss相关攻击的特定字符.
 *
 * 本软件仅对本次教程负责，版权所有 <a href="http://www.cnhuashao.com">中国，華少</a><br>
 *
 * @author cnHuaShao
 * <a href="mailto:lz2392504@gmail.com
 * <p>
 * ">cnHuaShao</a>
 * 修改备注：
 * @version v1.0.1 2019/11/5 19:10
 */
public class XssFilter implements Filter {

    private Logger log = LoggerFactory.getLogger(XssFilter.class);

    /**
     * 是否过滤富文本内容
     */
    private static boolean IS_INCLUDE_RICH_TEXT = false;

    /**
     * 预设定白名单地址
     * 将根据该变量中设置的相关目录进行直接放行操作。
     */
    public List<String> excludes = new ArrayList<>();

    /**
     * 拦截器核心处理单元
     * 用于处理所有需要过滤的请求，在此进行确认其合法性
     * @param request
     * @param response
     * @param filterChain
     * @throws IOException
     * @throws ServletException
     */
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain filterChain) throws IOException,ServletException {
        if(log.isDebugEnabled()){
            log.debug("-------------------- get into xss filter --------------------");
        }
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse resp = (HttpServletResponse) response;
        //进行白名单过滤，如符合白名单，则直接放行
        if(handleExcludeUrl(req, resp)){
            filterChain.doFilter(request, response);
            return;
        }
        //开始进行深度过滤，判定其携带参数是否合法
        XssHttpServletRequestWrapper xssRequest = new XssHttpServletRequestWrapper((HttpServletRequest) request,IS_INCLUDE_RICH_TEXT);
        filterChain.doFilter(xssRequest, response);
    }

    /**
     *  白名单过滤器
     * @param request 拦截的请求
     * @param response 拦截的响应
     * @return  是否符合白名单
     */
    private boolean handleExcludeUrl(HttpServletRequest request, HttpServletResponse response) {
        //白名单为空时直接返回false，使其向下执行
        if (excludes == null || excludes.isEmpty()) {
            return false;
        }
        //提取访问的URL地址
        String url = request.getServletPath();
        log.info("开始进行过滤{} {}",new Date(),url);
        //开始根据白名单地址进行判定，如符合则直接放行
        for (String pattern : excludes) {
            Pattern p = Pattern.compile("^" + pattern);
            Matcher m = p.matcher(url);
            if (m.find()) {
                return true;
            }
        }

        return false;
    }

    /**
     * 初始化拦截器配置
     * @param filterConfig
     * @throws ServletException
     */
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {
        if(log.isDebugEnabled()){
            log.debug("----------------- xss filter init -----------------");
        }
        //获取其初始化时预设置的深度过滤开关，根据其预设的true、false进行确定其是否开启深度拦截
        String isIncludeRichText = filterConfig.getInitParameter("isIncludeRichText");
        if(StringUtils.isNotBlank(isIncludeRichText)){
            IS_INCLUDE_RICH_TEXT = BooleanUtils.toBoolean(isIncludeRichText);
        }
        //获取其初始化时预设置的白名单字符串，根据【，】符号进行截取存储。
        String temp = filterConfig.getInitParameter("excludes");
        if (temp != null) {
            String[] url = temp.split(",");
            for (int i = 0; url != null && i < url.length; i++) {
                excludes.add(url[i]);
            }
        }
    }
}

5、添加cookie拦截器

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

import javax.servlet.*;
import javax.servlet.http.Cookie;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.IOException;
import java.util.Date;

/**
 * 类 {@code CookieFilter} 会话Cookie拦截 <br> 用于对所有web会话的Cookie进行安全检查.
 *
 * 本软件仅对本次教程负责，版权所有 <a href="http://www.cnhuashao.com">中国，華少</a><br>
 *
 * @author cnHuaShao
 * <a href="mailto:lz2392504@gmail.com
 * <p>
 * ">cnHuaShao</a>
 * 修改备注：
 * @version v1.0.1 2019/11/5 20:10
 */
public class CookieFilter implements Filter{
    private static final Logger log = LoggerFactory.getLogger(CookieFilter.class);

    /**
     * 继承方法，拦截器初始化逻辑
     * @param filterConfig
     * @throws ServletException
     */
    @Override
    public void init(FilterConfig filterConfig) throws ServletException {

    }

    /**
     * 自定义拦截器，用于Cookie全局设置
     * @param request 请求
     * @param response 响应
     * @param chain  filterchain是servlet容器提供给开发人员的对象
     * @throws IOException
     * @throws ServletException
     */
    @Override
    public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException {
        HttpServletRequest req = (HttpServletRequest) request;
        HttpServletResponse resp = (HttpServletResponse) response;

        //日志打印
        if(log.isDebugEnabled()){
            String url = req.getServletPath();
            log.debug("-------- get into Cookie filter {} {}",new Date(),url);
        }
        //获取请求中的cookies
        Cookie[] cookies = req.getCookies();
        //如果不为空，则开始对其中的所有cookie进行设置
        if (cookies!=null){
            for (Cookie cookie : cookies){
                if (cookie!=null){
                    //设置cookie最大有效期，单位秒，当前设置一小时60*60
                    cookie.setMaxAge(3600);
                    //向浏览器指定，只允许https协议下才可以发送cookie
                    cookie.setSecure(true);
                    //设置cookie只能使用
                    cookie.setHttpOnly(true);
                    resp.addCookie(cookie);
                }
            }
        }
        //请求下发
        chain.doFilter(req,resp);
    }

    /**
     * 继承方法，在销毁filter时进行的操作
     */
    @Override
    public void destroy() {

    }
}

6、所有拦截器准备就绪，在其SpringBoot启动时进行加载

import com.cnhuashao.rapiddevelopment.core.demo4.filter.CookieFilter;
import com.cnhuashao.rapiddevelopment.core.demo4.filter.XssFilter;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.boot.web.servlet.FilterRegistrationBean;
import org.springframework.context.annotation.Bean;
import org.springframework.context.annotation.Configuration;

import java.util.HashMap;
import java.util.Map;

/**
 * 类 {@code XssConfig} Xss配置加载类 <br> 用于将Xss拦截器在系统初始时加载至web服务器中.
 * 本软件仅对本次教程负责，版权所有 <a href="http://www.cnhuashao.com">中国，華少</a><br>
 *
 * @author cnHuaShao
 * <a href="mailto:lz2392504@gmail.com
 * <p>
 * ">cnHuaShao</a>
 * 修改备注：
 * @version v1.0.1 2019/11/5 20:12
 */
@Configuration
public class XssConfig {

    private Logger log = LoggerFactory.getLogger(XssConfig.class);

    /**
     * cookie拦截器
     * 用于Cookie全局设置，主要设置有效期、https安全访问、httpOnly启用
     * @return
     */
    @Bean
    public FilterRegistrationBean cookieFilterRegistrationBean(){
        log.info("------------ Start Cookie Filter ------------");
        //1、启动拦截器
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
        //注册Cookie拦截器
        filterRegistrationBean.setFilter(new CookieFilter());
        //设置bean加载顺序
        filterRegistrationBean.setOrder(1);
        //启用注册
        filterRegistrationBean.setEnabled(true);
        //添加URL为全部，使其拦截器全局拦截
        filterRegistrationBean.addUrlPatterns("/*");
        return filterRegistrationBean;
    }

    /**
     * 配置初始全局拦截器Xss过滤器
     * @return FilterRegistrationBean
     */
    @Bean
    public FilterRegistrationBean xssFilterRegistrationBean() {
        log.info("------------ Start Xss Filter ------------");
        //1、启动拦截器
        FilterRegistrationBean filterRegistrationBean = new FilterRegistrationBean();
        //注册Xss拦截器
        filterRegistrationBean.setFilter(new XssFilter());
        //设置bean加载顺序
        filterRegistrationBean.setOrder(1);
        //启用注册
        filterRegistrationBean.setEnabled(true);
        //添加URL为全部，使其拦截器全局拦截
        filterRegistrationBean.addUrlPatterns("/*");
        //2、设置初始化方法
        Map<String, String> initParameters = new HashMap<String,String>(2);
        //设置白名单
        initParameters.put("excludes", "/static/*,/img/*,/js/*,/css/*");
        //是否启用深度过滤机制（文本过滤机制），默认fales
        initParameters.put("isIncludeRichText", "true");
        //为此注册设置init参数。调用此方法将替换任何*现有的init参数。
        filterRegistrationBean.setInitParameters(initParameters);
        return filterRegistrationBean;
    }

}