基于黑名单的xss过滤器

/**
 * 类名称：AntiXssFilter   
 * @version
 * 类描述：基于黑名单的xss过滤器
 * @version   
 * 创建人：xxx
 * @version
 * 创建时间：2015年11月3日 下午1:00:11 
 * @version  
 * 修改人：xxx 修改时间：2015年11月3日 下午1:00:11 
 * @version
 * 修改备注：   
 */
public class AntiXssFilter implements Filter {

    public void destroy() {
    }

    @SuppressWarnings("unchecked")
    public void doFilter(ServletRequest request, ServletResponse response,
            FilterChain chain) throws IOException, ServletException,UnsupportedEncodingException{
        HttpServletRequest req = (HttpServletRequest) request;
        
        HttpServletResponse res = (HttpServletResponse) response;
        res.setContentType("application/json;charset=UTF-8");
        // 校验head参数
        if(existsXssHeadElement(req)) {
            ResponseUtils.toJson(res, IResponseCode.FAIL, "错误的参数");
//            res.sendError(404);
            return;
        }
        // 校验body参数    
        Map<String, String[]> parameterMap = req.getParameterMap();
        for (Object key : parameterMap.keySet()) {
            String[] val = (String[]) parameterMap.get(key);
            for (String v : val) {
                if(null != v){
                    v = URLDecoder.decode(URLDecoder.decode(v, "utf-8"),"utf-8");
                }
                if(existsXssElement(v)){
                    ResponseUtils.toJson(res, IResponseCode.FAIL, "错误的参数");
//                    res.sendError(404);
                    return;
                }
            }
        }
        chain.doFilter(request, response);
    }
    
    /**
     * @Title: existsXssHeadElement
     * @Description: 校验header中的参数
     * @return: boolean
     * @throws UnsupportedEncodingException 
     */
    private boolean existsXssHeadElement(HttpServletRequest req) throws UnsupportedEncodingException {
        // 设备号
        String deviceNo = req.getHeader("deviceNo");
        if(null != deviceNo){
            deviceNo = URLDecoder.decode(URLDecoder.decode(deviceNo, "utf-8"),"utf-8");
            if(existsXssElement(deviceNo)) {
                return true;
            }
        }
        // 终端
        String client = req.getHeader("client");
        if(null != client){
            client = URLDecoder.decode(URLDecoder.decode(client, "utf-8"),"utf-8");
            if(existsXssElement(client)) {
                return true;
            }
        }
        // 渠道
        String channel = req.getHeader("channel");
        if(null != channel){
            channel = URLDecoder.decode(URLDecoder.decode(channel, "utf-8"),"utf-8");
            if(existsXssElement(channel)) {
                return true;
            }
        }
        // app版本号
        String version = req.getHeader("version");
        if(null != version){
            version = URLDecoder.decode(URLDecoder.decode(version, "utf-8"),"utf-8");
            if(existsXssElement(version)) {
                return true;
            }
        }
        // app版本号序号
        String build = req.getHeader("build");
        if(null != build){
            build = URLDecoder.decode(URLDecoder.decode(build, "utf-8"),"utf-8");
            if(existsXssElement(build)) {
                return true;
            }
        }
        // ip
        String ip = req.getHeader("ip");
        if(null != ip){
            ip = URLDecoder.decode(URLDecoder.decode(ip, "utf-8"),"utf-8");
            if(existsXssElement(ip)) {
                return true;
            }
        }
        return false;
    }

    public void init(FilterConfig arg0) throws ServletException {
    }
    
    /**
     * 黑名单
     * existsXssElement  
     * @param    
     * @return  
     * @throws 
     * @author zhuzheng
     * @date   2015年11月2日 下午1:12:16
     */
    private boolean existsXssElement(String s)
            throws UnsupportedEncodingException{
        boolean res = false;
        s = s.toLowerCase();
        res=getIncludeSqlSpecialCharsFlag(s);
        if(!res){
            res=getIncludeHtmlSpecialCharsFlag(s);
        }
        return res;
    }
    
    /**
     * 替换一些特殊字符
     * replaceSpecialChars  
     * @param    
     * @return  
     * @throws 
     * @author zhuzheng
     * @date   2015年11月2日 下午1:12:16
     */
    private String replaceSpecialChars(String s) throws UnsupportedEncodingException {
        String specialChar = "";
        s = s.replaceAll("(
|
|	|f|'|")", "");
        s = s.replaceAll("(
|
|	|f|'|")", "");
        int specialCharsLen = specailCharArray.length;
        for (int i = 0; i < specialCharsLen; i++) {
            specialChar = specailCharArray[i];
            specialChar = URLDecoder.decode(URLDecoder.decode(specialChar, "utf-8"), "utf-8");
            s = s.replaceAll(specialChar, "");
        }
        return s;
    }
    
    /**
     * 判断是否包含html特殊字符 
     * getIncludeHtmlSpecialCharsFlag  
     * @param    
     * @return  
     * @throws UnsupportedEncodingException 
     * @throws 
     * @author zhuzheng
     * @date   2015年11月2日 下午1:12:16
     */
    private boolean getIncludeHtmlSpecialCharsFlag(String s) throws UnsupportedEncodingException{
        boolean res = false;
//        s=replaceSpecialChars(s);
        if (    //XSS黑名单
                s.indexOf("javascript:") != -1 || s.indexOf("document.cookie") != -1
                || s.indexOf("<script") != -1 || s.indexOf("<iframe") != -1
                || s.indexOf(""><script>") != -1 || s.indexOf(""<script>") != -1
                || s.indexOf("<img") != -1 || s.indexOf("onclick=") != -1
                || s.indexOf("<style") != -1 || s.indexOf(")//") != -1
                || s.indexOf("">") != -1 || s.indexOf("<body") != -1
                || s.indexOf("/xss/") != -1 || s.indexOf("onfocus") != -1
                || s.indexOf("alert") != -1 //|| s.indexOf(";") != -1
                || s.indexOf("fromcharcode") != -1 || s.indexOf("eval") != -1
                || s.indexOf("<a") != -1 || s.indexOf("cookie") != -1
                || s.indexOf("document.write") != -1
            ) {
            ExceptionLogger.error("请求拦截可能存在SQL和脚本注入", "请求参数："+ s , null);
            res = true;
        }
        return res;
    }
    /**
     * 判断是否包含sql特殊字符 
     * getIncludeSqlSpecialCharsFlag  
     * @param    
     * @return  
     * @throws 
     * @author zhuzheng
     * @date   2015年11月2日 下午1:12:16
     */
    private boolean getIncludeSqlSpecialCharsFlag(String s) {
        // 过滤掉的sql关键字，可以手动添加
        String badStr = "'|and |exec |execute |insert |select |delete |update |count|drop |chr|mid|master|truncate |"
                + "char|declare |sitename|net user|xp_cmdshell|or |like'%|like '%|insert |create |"
                + "table|from|grant|use|group_concat|column_name|"
                + "information_schema.columns|table_schema|union |where |order by |group by ";
        String[] badStrs = badStr.split("\|");
        for (int i = 0; i < badStrs.length; i++) {
            if (s.indexOf(badStrs[i]) >= 0) {
                ExceptionLogger.error("请求拦截可能存在SQL和脚本注入", "请求参数："+ s , null);
                return true;
            }
        }
        return false;
    }
    
    private String[] specailCharArray = { "%00", "%2B", "%25E3%2580%2580" };

}