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