每一个开发者都会意识到,网站发布之前,需要进行安全检查。
那么如何拦截攻击者注入恶意代码?如何防御诸如跨站脚本攻击(XSS)、SQL注入攻击等恶意攻击行为?
针对目前常见的一些安全问题,结合目前一些常见的防护办法,通用权限管理系统底层增加了安全防护代码,
现将源码提供如下
namespace DotNet.Utilities {/// <summary>/// 网站安全通用防护/// /// 主要功能:/// 拦截攻击者注入恶意代码,可以防御诸如跨站脚本攻击(XSS)、SQL注入攻击等恶意攻击行为。/// /// 修改纪录/// /// 2013-12-27,更新正则表达式避免误报问题。/// 2013-01-08,更新了aspx防护脚本中referer变量冲突问题。/// 2013-01-09,加入了UTF7编码XSS的防护。/// 2013-01-28,增强了对XSS的防护。/// 2013-01-31,针对某些用户后台上传文件出错的问题。/// 2013-03-15,增强了对POST的防护。/// 2013-03-28,增强了对XSS的防护。/// 2013-04-25,对XSS防护加入了通用的防护方法。/// 2013-08-02,加入对XSS编码绕过的防护。/// 2013-08-14,增强利用样式的XSS防护。/// 2014-11-12,解决SQL盲注不拦截的问题。/// /// 2014-11-12 版本:1.0 SongBiao 创建文件。 /// /// <author>/// <name>SongBiao</name>/// <date>2014-11-12</date>/// </author>/// </summary>public partial class SecretUtil{//正则过滤字符private const string StrRegex = @"<[^>]+?style=[\w]+?:expression\(|\b(alert|confirm|prompt)\b|^\+/v(8|9)|<[^>]*?=[^>]*?&#[^>]*?>|\b(and|or)\b.{1,6}?(=|>|<|\bin\b|\blike\b)|/\*.+?\*/|<\s*script\b|<\s*img\b|\bEXEC\b|UNION.+?SELECT|UPDATE.+?SET|INSERT\s+INTO.+?VALUES|(SELECT|DELETE).+?FROM|(CREATE|ALTER|DROP|TRUNCATE)\s+(TABLE|DATABASE)";/// <summary>/// POST请求/// </summary>/// <param name="putData">输出非法字符串</param>/// <returns></returns>public static bool PostData(out string putData){bool result = false;putData = string.Empty;for (int i = 0; i < HttpContext.Current.Request.Form.Count; i++){result = CheckData(HttpContext.Current.Request.Form[i].ToString(), out putData);if (result){putData = HttpContext.Current.Request.Form[i].ToString();break;}}return result;}/// <summary>/// GET请求/// </summary>/// <param name="putData">输出非法字符串</param>/// <returns></returns>public static bool GetData(out string putData){bool result = false;putData = string.Empty;for (int i = 0; i < HttpContext.Current.Request.QueryString.Count; i++){result = CheckData(HttpContext.Current.Request.QueryString[i].ToString(), out putData);if (result){putData = HttpContext.Current.Request.QueryString[i].ToString();break;}}return result;}/// <summary>/// COOKIE/// </summary>/// <param name="putData">输出非法字符串</param>/// <returns></returns>public static bool CookieData(out string putData){bool result = false;putData = string.Empty;for (int i = 0; i < HttpContext.Current.Request.Cookies.Count; i++){result = CheckData(HttpContext.Current.Request.Cookies[i].Value.ToLower(), out putData);if (result){putData = HttpContext.Current.Request.Cookies[i].Value.ToLower();break;}}return result;}/// <summary>/// UrlReferrer请求来源/// </summary>/// <param name="putData">输出非法字符串</param>/// <returns></returns>public static bool Referer(out string putData){bool result = false;result = CheckData(HttpContext.Current.Request.UrlReferrer.ToString(), out putData);if (result){putData = HttpContext.Current.Request.UrlReferrer.ToString();}return result;}/// <summary>/// 正则检查/// </summary>/// <param name="inputData">字符串</param>/// <param name="putData">输出非法字符串</param>/// <returns></returns>public static bool CheckData(string inputData, out string putData){putData = string.Empty;//if (Regex.IsMatch(inputData.ToUpper(), StrRegex.ToUpper(),RegexOptions.IgnoreCase))if (Regex.IsMatch(inputData, StrRegex, RegexOptions.IgnoreCase)){putData = inputData;return true;}else{return false;}}}}
源码在通用权限底层中的位置:
调用方法:(ASP.NET MVC参考)在Global.asax文件中增加以下方法
/// <summary>/// 在此处进行安全检测和防范/// Application_BeginRequest/// </summary>/// <param name="sender"></param>/// <param name="e"></param>protected void Application_AcquireRequestState(object sender, EventArgs e){HttpContext context = HttpContext.Current;string putData = string.Empty;if (Request.Cookies != null){if (SecretUtil.CookieData(out putData)){ResponseWarnMessage(context, "Cookie数据有恶意字符!", putData);}}if (Request.UrlReferrer != null){if (SecretUtil.Referer(out putData)){ResponseWarnMessage(context, "Referrer数据有恶意字符!", putData);}}if (Request.RequestType.ToUpper() == "POST"){if (SecretUtil.PostData(out putData)){ResponseWarnMessage(context, "Post数据有恶意字符!", putData);}}if (Request.RequestType.ToUpper() == "GET"){if (SecretUtil.GetData(out putData)){ResponseWarnMessage(context, "Get数据有恶意字符!", putData);}}}/// <summary>/// 非安全行为 输出警告信息/// </summary>/// <param name="errorMessage"></param>/// <param name="putData"></param>private void ResponseWarnMessage(HttpContext context, string errorMessage, string putData){//记录一下恶意攻击行为string ipAddress = Utilities.GetIPAddress(true);BaseUserInfo userInfo = context.Session[DotNet.Business.Utilities.SessionName] as BaseUserInfo;//非安全行为同时记录到数据库和文本文件中LogHelper.OracleWarn(userInfo, "恶意访问行为", "来自IP:" + ipAddress + "的访问存在恶意行为:" + errorMessage + "字符内容:" + putData, " private void ResponseErrorMessage(string errorMessage, string putData)", typeof(MvcApplication), null);RouteData routeData = new RouteData();routeData.Values.Add("controller", "Error");routeData.Values.Add("action", "General");routeData.Values.Add("title", "非法访问与请求提醒");routeData.Values.Add("error", "你提交的" + errorMessage + "字符内容:" + putData);IController errorController = new ErrorController();errorController.Execute(new RequestContext(new HttpContextWrapper(Context), routeData));context.Response.End();}
上面的处理方法可根据需要自己调整,我是将攻击信息使用系统的日志功能记录到Oracle数据库中,并在页面显示攻击信息,
测试:在地址后加入"?action=delete from user"
以上安全代码也可单独放到你的程序中使用,建议尚未做安全防护的朋友尽快加上,避免受到一些常见的攻击行为骚扰。