asp.net下检测SQL注入式攻击代码

两个类：
（页面数据校验类）pagevalidate.cs 基本通用。
代码如下：

using system;
using system.text;
using system.web;
using system.web.ui.webcontrols;
using system.text.regularexpressions;

namespace common
{
    /// <summary>
    /// 页面数据校验类
    /// </summary>
    public class pagevalidate
    {
        private static regex regnumber = new regex("^[0-9]+$");
        private static regex regnumbersign = new regex("^[+-]?[0-9]+$");
        private static regex regdecimal = new regex("^[0-9]+[.]?[0-9]+$");
        private static regex regdecimalsign = new regex("^[+-]?[0-9]+[.]?[0-9]+$"); //等价于^[+-]?\d+[.]?\d+$
        private static regex regemail = new regex("^[\\w-]+@[\\w-]+\\.(com|net|org|edu|mil|tv|biz|info)$");//w 英文字母或数字的字符串，和 [a-za-z0-9] 语法一样
        private static regex regchzn = new regex("[\u4e00-\u9fa5]");

        public pagevalidate()
        {
        }


        #region 数字字符串检查        

        /// <summary>
        /// 检查request查询字符串的键值，是否是数字，最大长度限制
        /// </summary>
        /// <param name="req">request</param>
        /// <param name="inputkey">request的键值</param>
        /// <param name="maxlen">最大长度</param>
        /// <returns>返回request查询字符串</returns>
        public static string fetchinputdigit(httprequest req, string inputkey, int maxlen)
        {
            string retval = string.empty;
            if(inputkey != null && inputkey != string.empty)
            {
                retval = req.querystring[inputkey];
                if(null == retval)
                    retval = req.form[inputkey];
                if(null != retval)
                {
                    retval = sqltext(retval, maxlen);
                    if(!isnumber(retval))
                        retval = string.empty;
                }
            }
            if(retval == null)
                retval = string.empty;
            return retval;
        }        
        /// <summary>
        /// 是否数字字符串
        /// </summary>
        /// <param name="inputdata">输入字符串</param>
        /// <returns></returns>
        public static bool isnumber(string inputdata)
        {
            match m = regnumber.match(inputdata);
            return m.success;
        }        
        /// <summary>
        /// 是否数字字符串 可带正负号
        /// </summary>
        /// <param name="inputdata">输入字符串</param>
        /// <returns></returns>
        public static bool isnumbersign(string inputdata)
        {
            match m = regnumbersign.match(inputdata);
            return m.success;
        }        
        /// <summary>
        /// 是否是浮点数
        /// </summary>
        /// <param name="inputdata">输入字符串</param>
        /// <returns></returns>
        public static bool isdecimal(string inputdata)
        {
            match m = regdecimal.match(inputdata);
            return m.success;
        }        
        /// <summary>
        /// 是否是浮点数 可带正负号
        /// </summary>
        /// <param name="inputdata">输入字符串</param>
        /// <returns></returns>
        public static bool isdecimalsign(string inputdata)
        {
            match m = regdecimalsign.match(inputdata);
            return m.success;
        }        

        #endregion

        #region 中文检测

        /// <summary>
        /// 检测是否有中文字符
        /// </summary>
        /// <param name="inputdata"></param>
        /// <returns></returns>
        public static bool ishaschzn(string inputdata)
        {
            match m = regchzn.match(inputdata);
            return m.success;
        }    

        #endregion

        #region 邮件地址
        /// <summary>
        /// 是否是浮点数 可带正负号
        /// </summary>
        /// <param name="inputdata">输入字符串</param>
        /// <returns></returns>
        public static bool isemail(string inputdata)
        {
            match m = regemail.match(inputdata);
            return m.success;
        }        

        #endregion

        #region 其他

        /// <summary>
        /// 检查字符串最大长度，返回指定长度的串
        /// </summary>
        /// <param name="sqlinput">输入字符串</param>
        /// <param name="maxlength">最大长度</param>
        /// <returns></returns>            
        public static string sqltext(string sqlinput, int maxlength)
        {            
            if(sqlinput != null && sqlinput != string.empty)
            {
                sqlinput = sqlinput.trim();                            
                if(sqlinput.length > maxlength)//按最大长度截取字符串
                    sqlinput = sqlinput.substring(0, maxlength);
            }
            return sqlinput;
        }        
        /// <summary>
        /// 字符串编码
        /// </summary>
        /// <param name="inputdata"></param>
        /// <returns></returns>
        public static string htmlencode(string inputdata)
        {
            return httputility.htmlencode(inputdata);
        }
        /// <summary>
        /// 设置label显示encode的字符串
        /// </summary>
        /// <param name="lbl"></param>
        /// <param name="txtinput"></param>
        public static void setlabel(label lbl, string txtinput)
        {
            lbl.text = htmlencode(txtinput);
        }
        public static void setlabel(label lbl, object inputobj)
        {
            setlabel(lbl, inputobj.tostring());
        }        
        //字符串清理
        public static string inputtext(string inputstring, int maxlength)
        {            
            stringbuilder retval = new stringbuilder();

            // 检查是否为空
            if ((inputstring != null) && (inputstring != string.empty))
            {
                inputstring = inputstring.trim();

                //检查长度
                if (inputstring.length > maxlength)
                    inputstring = inputstring.substring(0, maxlength);

                //替换危险字符
                for (int i = 0; i < inputstring.length; i++)
                {
                    switch (inputstring[i])
                    {
                        case '"':
                            retval.append(""");
                            break;
                        case '<':
                            retval.append("<");
                            break;
                        case '>':
                            retval.append(">");
                            break;
                        default:
                            retval.append(inputstring[i]);
                            break;
                    }
                }                
                retval.replace("'", " ");// 替换单引号
            }
            return retval.tostring();

        }
        /// <summary>
        /// 转换成 html code
        /// </summary>
        /// <param name="str">string</param>
        /// <returns>string</returns>
        public static string encode(string str)
        {            
            str = str.replace("&","&");
            str = str.replace("'","''");
            str = str.replace("\"",""");
            str = str.replace(" "," ");
            str = str.replace("<","<");
            str = str.replace(">",">");
            str = str.replace("\n","<br>");
            return str;
        }
        /// <summary>
        ///解析html成 普通文本
        /// </summary>
        /// <param name="str">string</param>
        /// <returns>string</returns>
        public static string decode(string str)
        {            
            str = str.replace("<br>","\n");
            str = str.replace(">",">");
            str = str.replace("<","<");
            str = str.replace(" "," ");
            str = str.replace(""","\"");
            return str;
        }

        #endregion 

    }
}

通用文件（global.asax），保存为global.asax文件名 放到网站根木马下即可。（其他功能自行补上）

<script language="c#" runat="server"><!--
    protected void application_beginrequest(object sender, eventargs e)
        {
            startprocessrequest();
        }


/// <summary>
/// 处理用户提交的请求
/// </summary>
private void startprocessrequest()
{
try
{
string getkeys = "";

if (system.web.httpcontext.current.request.querystring != null)
{

for (int i = 0; i < system.web.httpcontext.current.request.querystring.count; i++)
{
getkeys = system.web.httpcontext.current.request.querystring.keys[i];
if (!processsqlstr(system.web.httpcontext.current.request.querystring[getkeys]))
{
system.web.httpcontext.current.response.write("get,出现错误,包含非法字符串");
system.web.httpcontext.current.response.end();
}
}
}
if (system.web.httpcontext.current.request.form != null)
{
for (int i = 0; i < system.web.httpcontext.current.request.form.count; i++)
{
getkeys = system.web.httpcontext.current.request.form.keys[i];
if (getkeys == "__viewstate") continue;
if (!processsqlstr(system.web.httpcontext.current.request.form[getkeys]))
{
system.web.httpcontext.current.response.write("post,出现错误,包含非法字符串");
system.web.httpcontext.current.response.end();
}
}
}
            if(system.web.httpcontext.current.request.cookies!=null)
            {
             for (int i = 0; i < system.web.httpcontext.current.request.cookies.count; i++)
{
getkeys = system.web.httpcontext.current.request.cookies.keys[i];
if (getkeys == "__viewstate") continue;
if (!processsqlstr(system.web.httpcontext.current.request.cookies[getkeys].value))
{
system.web.httpcontext.current.response.write("cookies,出现错误,包含非法字符串");
system.web.httpcontext.current.response.end();
}
}
            }

}
catch
{
// 错误处理: 处理用户提交信息!
}
}
/// <summary>
/// 分析用户请求是否正常
/// </summary>
/// <param name="str">传入用户提交数据 </param>
/// <returns>返回是否含有sql注入式攻击代码 </returns>
private bool processsqlstr(string str)
{
bool returnvalue = true;
try
{
if (str.trim() != "")
{
                string sqlstr = "select¦insert¦delete¦update¦declare¦sysobjects¦syscolumns¦cast¦truncate¦master¦mid¦exec";

                string[] anysqlstr = sqlstr.split('¦');
foreach (string ss in anysqlstr)
{
if (str.tolower().indexof(ss) >= 0)
{
returnvalue = false;
break;
}
}
}
}
catch
{
returnvalue = false;
}
return returnvalue;
}

// --></script>