java xssprotect_Java防止xss攻击

首先说一下思路，防止这种类似于注入攻击，就是使用拦截器(Filter)处理特殊字符或过滤特殊字符 今天介绍一个方法，利用覆盖Servlet的getParameter方法达到处理特殊字符的目的来解决(防止)Xss攻击 web.xml

XssEscape

cn.wuzhuti.filter.XssFilter

XssEscape

/*

REQUEST

Filter类(XssFilter.java)

package cn.wuzhuti.filter;

import java.io.IOException;

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;

public class XssFilter implements javax.servlet.Filter {

@Override

public void destroy() {

// TODO Auto-generated method stub

}

@Override

public void doFilter(ServletRequest request, ServletResponse response,

FilterChain filterChain) throws IOException, ServletException {

XssHttpServletRequestWrapper xssRequest = new XssHttpServletRequestWrapper((HttpServletRequest) request);

filterChain.doFilter(xssRequest, response);

}

@Override

public void init(FilterConfig arg0) throws ServletException {

// TODO Auto-generated method stub

}

}

最关键的类(XssHttpServletRequestWrapper.java) 继承servlet的HttpServletRequestWrapper，并重写相应的几个有可能带xss攻击的方法

package cn.wuzhuti.filter;

import java.io.StringReader;

import java.io.StringWriter;

import javax.servlet.http.HttpServletRequest;

import javax.servlet.http.HttpServletRequestWrapper;

import com.blogspot.radialmind.html.HTMLParser;

import com.blogspot.radialmind.xss.XSSFilter;

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。

* 如果需要获得原始的值，则通过super.getParameterValues(name)来获取

* 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。

* 如果需要获得原始的值，则通过super.getHeaders(name)来获取

* 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;

}

StringReader reader = new StringReader(s);

StringWriter writer = new StringWriter();

try {

HTMLParser.process(reader, writer, new XSSFilter(), true);

String result = writer.toString();

System.out.println("xssEncode-------------------------" + s + " = " + result);

return result;

} catch (NullPointerException e) {

return s;

} catch (Exception ex) {

ex.printStackTrace();

}

return null;

}

/**

* 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;

}

}

通过重写getParameter()等方法，实现简单的过滤，从而防止Xss攻击 依赖jar包

大家如果有更好的想法欢迎大家留言讨论。