先说一下实现思路:
1. 使用正则表达式的方式实现脚本过滤,这个方法准确率较高,但是可能根据不能的要求会变动;
2. 为了保证配置灵活(包括正则表达式灵活),使用xml配置文件的方式记录配置信息,配置信息包含是否开启校验、是否记录日志、是否中断请求、是否替换脚本字符等;
3. 为保证xml与正则表达式的特殊字符不冲突,使用<![CDATA[]]>标签存放正则表达式,但是在类中需要特殊处理;
4. 通过继承HttpRequestWrapper的方式实现request中header和parameter信息过滤;
5. xml解析使用dom4j,稍后会对这个工具的使用写一篇文章,暂时辛苦大家去网站查找资料(这篇文章很不错http://www.ibm.com/developerworks/cn/xml/x-dom4j.html);
6. 使用XSSSecurityManager类实现配置信息加载和处理,XSSSecurityConfig记录匹配信息,XSSSecurityCon标识程序所需常量;
附件包含源码,如果能帮我改进更好
package com.sg.security; import java.io.IOException; import java.util.Enumeration; import java.util.Map; import java.util.Set; import javax.servlet.ServletException; import javax.servlet.http.HttpServletRequest; import javax.servlet.http.HttpServletRequestWrapper; import javax.servlet.http.HttpServletResponse; /** * @author winnie * @date * @describe request信息封装类,用于判断、处理request请求中特殊字符 */ public class XSSHttpRequestWrapper extends HttpServletRequestWrapper { /** * 封装http请求 * @param request */ public XSSHttpRequestWrapper(HttpServletRequest request) { super(request); } @Override public String getHeader(String name) { String value = super.getHeader(name); // 若开启特殊字符替换,对特殊字符进行替换 if(XSSSecurityConfig.REPLACE){ XSSSecurityManager.securityReplace(name); } return value; } @Override public String getParameter(String name) { String value = super.getParameter(name); // 若开启特殊字符替换,对特殊字符进行替换 if(XSSSecurityConfig.REPLACE){ XSSSecurityManager.securityReplace(name); } return value; } /** * 没有违规的数据,就返回false; * * @return */ @SuppressWarnings("unchecked") private boolean checkHeader(){ Enumeration<String> headerParams = this.getHeaderNames(); while(headerParams.hasMoreElements()){ String headerName = headerParams.nextElement(); String headerValue = this.getHeader(headerName); if(XSSSecurityManager.matches(headerValue)){ return true; } } return false; } /** * 没有违规的数据,就返回false; * * @return */ @SuppressWarnings("unchecked") private boolean checkParameter(){ Map<String,Object> submitParams = this.getParameterMap(); Set<String> submitNames = submitParams.keySet(); for(String submitName : submitNames){ Object submitValues = submitParams.get(submitName); if(submitValues instanceof String){ if(XSSSecurityManager.matches((String)submitValues)){ return true; } }else if(submitValues instanceof String[]){ for(String submitValue : (String[])submitValues){ if(XSSSecurityManager.matches((String)submitValue)){ return true; } } } } return false; } /** * 没有违规的数据,就返回false; * 若存在违规数据,根据配置信息判断是否跳转到错误页面 * @param response * @return * @throws IOException * @throws ServletException */ public boolean validateParameter(HttpServletResponse response) throws ServletException, IOException{ // 开始header校验,对header信息进行校验 if(XSSSecurityConfig.IS_CHECK_HEADER){ if(this.checkHeader()){ return true; } } // 开始parameter校验,对parameter信息进行校验 if(XSSSecurityConfig.IS_CHECK_PARAMETER){ if(this.checkParameter()){ return true; } } return false; } }
/** * */ package com.sg.security; 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; import javax.servlet.http.HttpServletResponse; import org.apache.log4j.Logger; /** * @author winnie * @date * @describe 安全信息审核类 */ public class XSSSecurityFilter implements Filter{ private static Logger logger = Logger.getLogger(XSSSecurityFilter.class); /** * 销毁操作 */ public void destroy() { logger.info("XSSSecurityFilter destroy() begin"); XSSSecurityManager.destroy(); logger.info("XSSSecurityFilter destroy() end"); } /** * 安全审核 * 读取配置信息 */ public void doFilter(ServletRequest request, ServletResponse response, FilterChain chain) throws IOException, ServletException { // 判断是否使用HTTP checkRequestResponse(request, response); // 转型 HttpServletRequest httpRequest = (HttpServletRequest) request; HttpServletResponse httpResponse = (HttpServletResponse) response; // http信息封装类 XSSHttpRequestWrapper xssRequest = new XSSHttpRequestWrapper(httpRequest); // 对request信息进行封装并进行校验工作,若校验失败(含非法字符),根据配置信息进行日志记录和请求中断处理 if(xssRequest.validateParameter(httpResponse)){ if(XSSSecurityConfig.IS_LOG){ // 记录攻击访问日志 // 可使用数据库、日志、文件等方式 } if(XSSSecurityConfig.IS_CHAIN){ httpRequest.getRequestDispatcher(XSSSecurityCon.FILTER_ERROR_PAGE).forward( httpRequest, httpResponse); return; } } chain.doFilter(xssRequest, response); } /** * 初始化操作 */ public void init(FilterConfig filterConfig) throws ServletException { XSSSecurityManager.init(filterConfig); } /** * 判断Request ,Response 类型 * @param request * ServletRequest * @param response * ServletResponse * @throws ServletException */ private void checkRequestResponse(ServletRequest request, ServletResponse response) throws ServletException { if (!(request instanceof HttpServletRequest)) { throw new ServletException("Can only process HttpServletRequest"); } if (!(response instanceof HttpServletResponse)) { throw new ServletException("Can only process HttpServletResponse"); } } }
/** * */ package com.sg.security; import java.util.Iterator; import java.util.regex.Pattern; import javax.servlet.FilterConfig; import org.apache.log4j.Logger; import org.dom4j.DocumentException; import org.dom4j.Element; import org.dom4j.io.SAXReader; /** * @author winnie * @date * @describe 安全过滤配置管理类,由XSSSecurityManger修改 */ public class XSSSecurityManager { private static Logger logger = Logger.getLogger(XSSSecurityManager.class); /** * REGEX:校验正则表达式 */ public static String REGEX; /** * 特殊字符匹配 */ private static Pattern XSS_PATTERN ; private XSSSecurityManager(){ //不可被实例化 } public static void init(FilterConfig config){ logger.info("XSSSecurityManager init(FilterConfig config) begin"); //初始化过滤配置文件 String xssPath = config.getServletContext().getRealPath("/") + config.getInitParameter("securityconfig"); // 初始化安全过滤配置 try { if(initConfig(xssPath)){ // 生成匹配器 XSS_PATTERN = Pattern.compile(REGEX); } } catch (DocumentException e) { logger.error("安全过滤配置文件xss_security_config.xml加载异常",e); } logger.info("XSSSecurityManager init(FilterConfig config) end"); } /** * 读取安全审核配置文件xss_security_config.xml * 设置XSSSecurityConfig配置信息 * @param path 配置文件地址 eg C:/apache-tomcat-6.0.33/webapps/security_filter/WebRoot/config/xss/xss_security_config.xml * @return * @throws DocumentException */ @SuppressWarnings("unchecked") public static boolean initConfig(String path) throws DocumentException { logger.info("XSSSecurityManager.initConfig(String path) begin"); Element superElement = new SAXReader().read(path).getRootElement(); XSSSecurityConfig.IS_CHECK_HEADER = new Boolean(getEleValue(superElement,XSSSecurityCon.IS_CHECK_HEADER)); XSSSecurityConfig.IS_CHECK_PARAMETER = new Boolean(getEleValue(superElement,XSSSecurityCon.IS_CHECK_PARAMETER)); XSSSecurityConfig.IS_LOG = new Boolean(getEleValue(superElement,XSSSecurityCon.IS_LOG)); XSSSecurityConfig.IS_CHAIN = new Boolean(getEleValue(superElement,XSSSecurityCon.IS_CHAIN)); XSSSecurityConfig.REPLACE = new Boolean(getEleValue(superElement,XSSSecurityCon.REPLACE)); Element regexEle = superElement.element(XSSSecurityCon.REGEX_LIST); if(regexEle != null){ Iterator<Element> regexIt = regexEle.elementIterator(); StringBuffer tempStr = new StringBuffer("^"); //xml的cdata标签传输数据时,会默认在\前加\,需要将\\替换为\ while(regexIt.hasNext()){ Element regex = (Element)regexIt.next(); String tmp = regex.getText(); tmp = tmp.replaceAll("\\\\\\\\", "\\\\"); tempStr.append(tmp); tempStr.append("|"); } if(tempStr.charAt(tempStr.length()-1)=='|'){ REGEX= tempStr.substring(0, tempStr.length()-1)+"$"; logger.info("安全匹配规则"+REGEX); }else{ logger.error("安全过滤配置文件加载失败:正则表达式异常 "+tempStr.toString()); return false; } }else{ logger.error("安全过滤配置文件中没有 "+XSSSecurityCon.REGEX_LIST+" 属性"); return false; } logger.info("XSSSecurityManager.initConfig(String path) end"); return true; } /** * 从目标element中获取指定标签信息,若找不到该标签,记录错误日志 * @param element 目标节点 * @param tagName 制定标签 * @return */ private static String getEleValue(Element element, String tagName){ if (isNullStr(element.elementText(tagName))){ logger.error("安全过滤配置文件中没有 "+XSSSecurityCon.REGEX_LIST+" 属性"); } return element.elementText(tagName); } /** * 对非法字符进行替换 * @param text * @return */ public static String securityReplace(String text){ if(isNullStr(text)){ return text; }else{ return text.replaceAll(REGEX, XSSSecurityCon.REPLACEMENT); } } /** * 匹配字符是否含特殊字符 * @param text * @return */ public static boolean matches(String text){ if(text==null){ return false; } return XSS_PATTERN.matcher(text).matches(); } /** * 释放关键信息 */ public static void destroy(){ logger.info("XSSSecurityManager.destroy() begin"); XSS_PATTERN = null; REGEX = null; logger.info("XSSSecurityManager.destroy() end"); } /** * 判断是否为空串,建议放到某个工具类中 * @param value * @return */ public static boolean isNullStr(String value){ return value == null || value.trim().equals(""); } }
/** * */ package com.sg.security; /** * @author winnie * 安全过滤配置信息类 */ public class XSSSecurityConfig { /** * CHECK_HEADER:是否开启header校验 */ public static boolean IS_CHECK_HEADER; /** * CHECK_PARAMETER:是否开启parameter校验 */ public static boolean IS_CHECK_PARAMETER; /** * IS_LOG:是否记录日志 */ public static boolean IS_LOG; /** * IS_LOG:是否中断操作 */ public static boolean IS_CHAIN; /** * REPLACE:是否开启替换 */ public static boolean REPLACE; }
/** * */ package com.sg.security; /** * @author winnie * @date * @describe */ public class XSSSecurityCon { /** * 配置文件标签 isCheckHeader */ public static String IS_CHECK_HEADER = "isCheckHeader"; /** * 配置文件标签 isCheckParameter */ public static String IS_CHECK_PARAMETER = "isCheckParameter"; /** * 配置文件标签 isLog */ public static String IS_LOG = "isLog"; /** * 配置文件标签 isChain */ public static String IS_CHAIN = "isChain"; /** * 配置文件标签 replace */ public static String REPLACE = "replace"; /** * 配置文件标签 regexList */ public static String REGEX_LIST = "regexList"; /** * 替换非法字符的字符串 */ public static String REPLACEMENT = ""; /** * FILTER_ERROR_PAGE:过滤后错误页面 */ public static String FILTER_ERROR_PAGE = "/common/filtererror.jsp"; }
xss_security_config.xml
<?xml version="1.0" encoding="UTF-8"?> <XSSConfig> <!-- 是否进行header校验 --> <isCheckHeader>false</isCheckHeader> <!-- 是否进行parameter校验 --> <isCheckParameter>true</isCheckParameter> <!-- 是否记录日志 --> <isLog>true</isLog> <!-- 是否中断请求 --> <isChain>false</isChain> <!-- 是否开启特殊字符替换 --> <replace>true</replace> <!-- 是否开启特殊url校验 --> <isCheckUrl>true</isCheckUrl> <regexList> <!-- 匹配含有字符: alert( ) --> <regex><![CDATA[.*[A|a][L|l][E|e][R|r][T|t]\\s*\\(.*\\).*]]></regex> <!-- 匹配含有字符: window.location = --> <regex><![CDATA[.*[W|w][I|i][N|n][D|d][O|o][W|w]\\.[L|l][O|o][C|c][A|a][T|t][I|i][O|o][N|n]\\s*=.*]]></regex> <!-- 匹配含有字符:style = x:ex pression ( ) --> <regex><![CDATA[.*[S|s][T|t][Y|y][L|l][E|e]\\s*=.*[X|x]:[E|e][X|x].*[P|p][R|r][E|e][S|s]{1,2}[I|i][O|o][N|n]\\s*\\(.*\\).*]]></regex> <!-- 匹配含有字符: document.cookie --> <regex><![CDATA[.*[D|d][O|o][C|c][U|u][M|m][E|e][N|n][T|t]\\.[C|c][O|o]{2}[K|k][I|i][E|e].*]]></regex> <!-- 匹配含有字符: eval( ) --> <regex><![CDATA[.*[E|e][V|v][A|a][L|l]\\s*\\(.*\\).*]]></regex> <!-- 匹配含有字符: unescape() --> <regex><![CDATA[.*[U|u][N|n][E|e][S|s][C|c][A|a][P|p][E|e]\\s*\\(.*\\).*]]></regex> <!-- 匹配含有字符: execscript( ) --> <regex><![CDATA[.*[E|e][X|x][E|e][C|c][S|s][C|c][R|r][I|i][P|p][T|t]\\s*\\(.*\\).*]]></regex> <!-- 匹配含有字符: msgbox( ) --> <regex><![CDATA[.*[M|m][S|s][G|g][B|b][O|o][X|x]\\s*\\(.*\\).*]]></regex> <!-- 匹配含有字符: confirm( ) --> <regex><![CDATA[.*[C|c][O|o][N|n][F|f][I|i][R|r][M|m]\\s*\\(.*\\).*]]></regex> <!-- 匹配含有字符: prompt( ) --> <regex><![CDATA[.*[P|p][R|r][O|o][M|m][P|p][T|t]\\s*\\(.*\\).*]]></regex> <!-- 匹配含有字符: <script> </script> --> <regex><![CDATA[.*<[S|s][C|c][R|r][I|i][P|p][T|t]>.*</[S|s][C|c][R|r][I|i][P|p][T|t]>.*]]></regex> <!-- 匹配含有字符: 含有一个符号: " --> <regex><![CDATA[[.&[^\"]]*\"[.&[^\"]]*]]></regex> <!-- 匹配含有字符: 含有一个符号: ' --> <regex><![CDATA[[.&[^']]*'[.&[^']]*]]></regex> <!-- 匹配含有字符: 含有回车换行 和 <script> </script> --> <regex><![CDATA[[[.&[^a]]|[|a|\n|\r\n|\r|\u0085|\u2028|\u2029]]*<[S|s][C|c][R|r][I|i][P|p][T|t]>.*</[S|s][C|c][R|r][I|i][P|p][T|t]>[[.&[^a]]|[|a|\n|\r\n|\r|\u0085|\u2028|\u2029]]*]]></regex> </regexList> </XSSConfig>
web.xml配置
<?xml version="1.0" encoding="UTF-8"?> <web-app version="2.5" xmlns="http://java.sun.com/xml/ns/javaee" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://java.sun.com/xml/ns/javaee http://java.sun.com/xml/ns/javaee/web-app_2_5.xsd"> <welcome-file-list> <welcome-file>index.jsp</welcome-file> </welcome-file-list> <!-- 信息安全审核 --> <filter> <filter-name>XSSFiler</filter-name> <filter-class> com.sg.security.XSSSecurityFilter </filter-class> <init-param> <param-name>securityconfig</param-name> <param-value> /WebRoot/config/xss/xss_security_config.xml </param-value> </init-param> </filter> <!-- 拦截请求类型 --> <filter-mapping> <filter-name>XSSFiler</filter-name> <url-pattern>*.jsp</url-pattern> </filter-mapping> <filter-mapping> <filter-name>XSSFiler</filter-name> <url-pattern>*.do</url-pattern> </filter-mapping> </web-app>