防止常见XSS 过滤 SQL注入 JAVA过滤器filter

XSS : 跨站脚本攻击(Cross Site Scripting)，为不和层叠样式表(Cascading Style Sheets, CSS)的缩写混淆，故将跨站脚本攻击缩写为XSS。恶意攻击者往Web页面里插入恶意html代码，当用户浏览该页之时，嵌入其中Web里面的html代码会被执行，从而达到恶意攻击用户的特殊目的。

sql注入
所谓SQL注入，就是通过把SQL命令插入到Web表单提交或输入域名或页面请求的查询字符串，最终达到欺骗服务器执行恶意的SQL命令。具体来说，它是利用现有应用程序，将（恶意）的SQL命令注入到后台数据库引擎执行的能力，它可以通过在Web表单中输入（恶意）SQL语句得到一个存在安全漏洞的网站上的数据库，而不是按照设计者意图去执行SQL语句。

1、首先配置web.xml，添加如下配置信息：

    <!-- 解决xss & sql漏洞 -->

    <filter>

        <filter-name>xssAndSqlFilter</filter-name>

        <filter-class>com.cup.cms.web.framework.filter.XssAndSqlFilter</filter-class>

    </filter>

    <!-- 解决xss & sql漏洞 -->

    <filter-mapping>

        <filter-name>xssAndSqlFilter</filter-name>

        <url-pattern>*</url-pattern>

    </filter-mapping>

2、编写过滤器

/**

 *

 */

package com.cup.cms.web.framework.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;  

/**

 * @Author hithedy

 * @Date 2016年2月2日

 * @Time 下午2:01:53

 */

public class XssAndSqlFilter implements Filter {  

    @Override

    public void destroy() {

        // TODO Auto-generated method stub  

    }  

    @Override

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

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

        chain.doFilter(xssRequest, response);

    }  

    @Override

    public void init(FilterConfig arg0) throws ServletException {

        // TODO Auto-generated method stub  

    }  

}

3、包装器

    /**

     *

     */

    package com.cup.cms.web.framework.filter;  

    import java.util.regex.Pattern;  

    import javax.servlet.http.HttpServletRequest;

    import javax.servlet.http.HttpServletRequestWrapper;  

    /**

     * @Author hithedy

     * @Date 2016年2月2日

     * @Time 下午2:03:19

     */

    public class XssAndSqlHttpServletRequestWrapper extends HttpServletRequestWrapper {  

        HttpServletRequest orgRequest = null;  

        public XssAndSqlHttpServletRequestWrapper(HttpServletRequest request) {

            super(request);

            orgRequest = request;

        }  

        /**

         * 覆盖getParameter方法，将参数名和参数值都做xss & sql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 & sql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 & 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();

        }  

        /**

         * 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 XssAndSqlHttpServletRequestWrapper) {

                return ((XssAndSqlHttpServletRequestWrapper) req).getOrgRequest();

            }  

            return req;

        }  

        /**

         *

         * 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| | ]*>(.*?)</[\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 </script> tag

                scriptPattern = Pattern.compile("</[\r\n| | ]*script[\r\n| | ]*>", Pattern.CASE_INSENSITIVE);

                value = scriptPattern.matcher(value).replaceAll("");

                // Remove any lonesome <script ...> tag

                scriptPattern = Pattern.compile("<[\r\n| | ]*script(.*?)>", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);

                value = scriptPattern.matcher(value).replaceAll("");

                // Avoid eval(...) expressions

                scriptPattern = Pattern.compile("eval\\((.*?)\\)", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);

                value = scriptPattern.matcher(value).replaceAll("");

                // Avoid e-xpression(...) expressions

                scriptPattern = Pattern.compile("e-xpression\\((.*?)\\)", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);

                value = scriptPattern.matcher(value).replaceAll("");

                // Avoid javascript:... expressions

                scriptPattern = Pattern.compile("javascript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);

                value = scriptPattern.matcher(value).replaceAll("");

                // Avoid vbscript:... expressions

                scriptPattern = Pattern.compile("vbscript[\r\n| | ]*:[\r\n| | ]*", Pattern.CASE_INSENSITIVE);

                value = scriptPattern.matcher(value).replaceAll("");

                // Avoid onload= expressions

                scriptPattern = Pattern.compile("onload(.*?)=", Pattern.CASE_INSENSITIVE | Pattern.MULTILINE | Pattern.DOTALL);

                value = scriptPattern.matcher(value).replaceAll("");

            }

            return value;

        }  

    }

当这样子配置之后，可以有效防止大部分的xss攻击。

转载自：http://blog.csdn.net/hithedy/article/details/50630109

巴特西

防止常见XSS 过滤 SQL注入 JAVA过滤器filter

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