JFinal如何进行XSS攻击过滤
为啥要做XSS过滤?
比如一个文本框, 正常来说应该是输入普通文本,但是如果有it基础尤其是前端js比较熟悉的童鞋,就可以在这里面写js代码和html代码如下:
这还只是普通的代码, 如果可以他能写一个死循环一直弹窗,让你不得不去数据库更改这个数据.
我现在用到的是JBoot框架, 于是就需要用JFinal来解决这个问题
JBoot的web.xml文件中,配置过滤器
<filter>
<filter-name>jfinalfilter-name>
<filter-class>com.jfinal.core.JFinalFilterfilter-class>
<init-param>
<param-name>configClassparam-name>
<init-param>
<param-name>configClassparam-name>
<param-value>com.hz.shop.api.gateway.config.XssConfigparam-value>
init-param>
init-param>
filter>这里我自己定义了一个XssConfig类, 继承了JbootAppConfig, JbootAppConfig又继承了JFinalConfig, 实现了5个方法
/**
* Config constant
*/
public abstract void configConstant(Constants me);
/**
* Config route
*/
public abstract void configRoute(Routes me);
/**
* Config plugin
*/
public abstract void configPlugin(Plugins me);
/**
* Config interceptor applied to all actions.
*/
public abstract void configInterceptor(Interceptors me);
/**
* Config handler
*/
public abstract void configHandler(Handlers me);JbootAppConfig已经帮我们实现了这5个方法,我们只专注于configHandler(Handlers me)这个方法
package com.hz.shop.api.gateway.config;
import com.hz.shop.api.gateway.handler.XssHandler;
import com.jfinal.config.Handlers;
import io.jboot.web.JbootAppConfig;
public class XssConfig extends JbootAppConfig {
/*
* 配置处理器
* 添加我们自己的handler
*/
@Override
public void configHandler(Handlers handlers) {
handlers.add(new XssHandler());
super.configHandler(handlers);
}
}
这里我们需要再写一个XssHandler, 它继承了Jfinal的Handler
package com.hz.shop.api.gateway.handler;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import com.jfinal.handler.Handler;
/**
* 自己定义的处理器
* @author Admin
*/
public class XssHandler extends Handler{
@Override
public void handle(String target, HttpServletRequest request, HttpServletResponse response, boolean[] isHandled) {
request = new XssRequestWrapper(request);
next.handle(target, request, response, isHandled);
}
}
这里我们需要再定义一个自己的RequestWrapper类,它继承了HttpServletRequestWrapper ,在这个类中, 我们对request中的获取参数方法进行重写, 获得我们需要的, 安全的参数
package com.hz.shop.api.gateway.handler;
import java.util.HashMap;
import java.util.Iterator;
import java.util.Map;
import java.util.logging.Logger;
import java.util.regex.Pattern;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletRequestWrapper;
public class XssRequestWrapper extends HttpServletRequestWrapper {
private HttpServletRequest request;
public XssRequestWrapper(HttpServletRequest request) {
super(request);
this.request = request;
}
/**
* 重写getParameter方法
*/
@Override
public String getParameter(String name) {
String value = super.getParameter(name);
if (value == null) {
return null;
}
value = format(value);
return value;
}
/**
* 重写getParameterMap
*/
@Override
@SuppressWarnings("unchecked")
public Map getParameterMap() {
HashMap paramMap = (HashMap) super.getParameterMap();
paramMap = (HashMap) paramMap.clone();
for (Iterator iterator = paramMap.entrySet().iterator(); iterator.hasNext(); ) {
Map.Entry entry = (Map.Entry) iterator.next();
String [] values = entry.getValue();
for (int i = 0; i < values.length; i++) {
if(values[i] instanceof String){
values[i] = format(values[i]);
}
}
entry.setValue(values);
}
return paramMap;
}
/**
* 重写getParameterValues
*/
@Override
public String[] getParameterValues(String name) {
String[] values = super.getParameterValues(name);
int count = values.length;
String[] encodedValues = new String[count];
for (int i = 0; i < count; i++) {
encodedValues[i] = format(values[i]);
}
return encodedValues;
}
/**
* 重写getHeader
*/
@Override
public String getHeader(String name) {
// TODO Auto-generated method stub
return format(super.getHeader(name));
}
public String filter(String message) {
if (message == null)
return (null);
message = format(message);
return message;
}
/**
* @desc 统一处理特殊字符的方法，替换掉sql和js的特殊字符
* @param name 要替换的字符
*/
private String format(String name) {
return xssEncode(name);
}
/**
* 将容易引起xss & sql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;
}else{
s = stripXSSAndSql(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;
case '#':
sb.append("＃");// 转义#
break;
default:
sb.append(c);
break;
}
}
return sb.toString();
}
/**
*
* 防止xss跨脚本攻击（替换，根据实际情况调整）
*/
public static String stripXSSAndSql(String value) {
if (value != null) {
// NOTE: It's highly recommended to use the ESAPI library and
// uncomment the following line to
// avoid encoded attacks.
// value = ESAPI.encoder().canonicalize(value);
// Avoid null characters
/** value = value.replaceAll("", "");***/
// Avoid anything between script tags
Pattern scriptPattern = Pattern.compile("<[\r\n| | ]*script[\r\n| | ]*>(.*?)", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Avoid anything in a src="http://www.yihaomen.com/article/java/..." type of e-xpression
scriptPattern = Pattern.compile("src[\r\n| | ]*=[\r\n| | ]*[\\\"|\\\'](.*?)[\\\"|\\\']", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);
value = scriptPattern.matcher(value).replaceAll("");
// Remove any lonesome tag
scriptPattern = Pattern.compile("", Pattern.CASE_INSENSITIVE);
value = scriptPattern.matcher(value).replaceAll("");
// Remove any lonesome