C#過濾sql特殊字串的方法

2022-07-05 14:03:27

1.過濾不安全的字串

    /// <summary>
    /// 過濾不安全的字串
    /// </summary>
    /// <param name="Str"></param>
    /// <returns></returns>
    public static string FilteSQLStr(string Str)
    {

        Str = Str.Replace("'", "");
        Str = Str.Replace(""", "");
        Str = Str.Replace("&", "&amp");
        Str = Str.Replace("<", "&lt");
        Str = Str.Replace(">", "&gt");

        Str = Str.Replace("delete", "");
        Str = Str.Replace("update", "");
        Str = Str.Replace("insert", "");

        return Str; 
    }

2.過濾 Sql 語句字串中的注入指令碼

        #region 過濾 Sql 語句字串中的注入指令碼
        /// <summary>
        /// 過濾 Sql 語句字串中的注入指令碼
        /// </summary>
        /// <param name="source">傳入的字串</param>
        /// <returns>過濾後的字串</returns>
        public static string SqlFilter(string source)
        {
            //單引號替換成兩個單引號
            source = source.Replace("'", "''");

            //半形封號替換為全形封號，防止多語句執行
            source = source.Replace(";", "；");

            //半形括號替換為全形括號
            source = source.Replace("(", "（");
            source = source.Replace(")", "）");

            ///////////////要用正規表示式替換，防止字母大小寫得情況////////////////////

            //去除執行儲存過程的命令關鍵字
            source = source.Replace("Exec", "");
            source = source.Replace("Execute", "");

            //去除系統儲存過程或擴充套件儲存過程關鍵字
            source = source.Replace("xp_", "x p_");
            source = source.Replace("sp_", "s p_");

            //防止16進位制注入
            source = source.Replace("0x", "0 x");

            return source;
        }
        #endregion

3.過濾SQL字元

        /// 過濾SQL字元。
        /// </summary>
        /// <param name="str">要過濾SQL字元的字串。</param>
        /// <returns>已過濾掉SQL字元的字串。</returns>
        public static string ReplaceSQLChar(string str)
        {
            if (str == String.Empty)
                return String.Empty; str = str.Replace("'", "‘");
            str = str.Replace(";", "；");
            str = str.Replace(",", ",");
            str = str.Replace("?", "?");
            str = str.Replace("<", "＜");
            str = str.Replace(">", "＞");
            str = str.Replace("(", "(");
            str = str.Replace(")", ")");
            str = str.Replace("@", "＠");
            str = str.Replace("=", "＝");
            str = str.Replace("+", "＋");
            str = str.Replace("*", "＊");
            str = str.Replace("&", "＆");
            str = str.Replace("#", "＃");
            str = str.Replace("%", "％");
            str = str.Replace("$", "￥");

            return str;
        }

4.過濾標記

/// <summary>
/// 過濾標記
/// </summary>
/// <param name="NoHTML">包括HTML，指令碼，資料庫關鍵字，特殊字元的原始碼 </param>
/// <returns>已經去除標記後的文字</returns>
public string NoHtml(string Htmlstring)
{
    if (Htmlstring == null)
    {
        return "";
    }
    else
    {
        //刪除指令碼
         Htmlstring = Regex.Replace(Htmlstring, @"<script[^>]*?>.*?</script>", "", RegexOptions.IgnoreCase);
        //刪除HTML
        Htmlstring = Regex.Replace(Htmlstring, @"<(.[^>]*)>", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, @"([rn])[s]+", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, @"-->", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, @"<!--.*", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, @"&(quot|#34);", """, RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, @"&(amp|#38);", "&", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, @"&(lt|#60);", "<", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, @"&(gt|#62);", ">", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, @"&(nbsp|#160);", " ", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, @"&(iexcl|#161);", "xa1", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, @"&(cent|#162);", "xa2", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, @"&(pound|#163);", "xa3", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, @"&(copy|#169);", "xa9", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, @"&#(d+);", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "xp_cmdshell", "", RegexOptions.IgnoreCase);

        //刪除與資料庫相關的詞
         Htmlstring = Regex.Replace(Htmlstring, "select", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "insert", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "delete from", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "count''", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "drop table", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "truncate", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "asc", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "mid", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "char", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "xp_cmdshell", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "exec master", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "net localgroup administrators", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "and", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "net user", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "or", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "net", "", RegexOptions.IgnoreCase);
        //Htmlstring = Regex.Replace(Htmlstring, "*", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "-", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "delete", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "drop", "", RegexOptions.IgnoreCase);
        Htmlstring = Regex.Replace(Htmlstring, "script", "", RegexOptions.IgnoreCase);

        //特殊的字元
         Htmlstring = Htmlstring.Replace("<", "");
        Htmlstring = Htmlstring.Replace(">", "");
        Htmlstring = Htmlstring.Replace("*", "");
        Htmlstring = Htmlstring.Replace("-", "");
        Htmlstring = Htmlstring.Replace("?", "");
        Htmlstring = Htmlstring.Replace("'", "''");
        Htmlstring = Htmlstring.Replace(",", "");
        Htmlstring = Htmlstring.Replace("/", "");
        Htmlstring = Htmlstring.Replace(";", "");
        Htmlstring = Htmlstring.Replace("*/", "");
        Htmlstring = Htmlstring.Replace("rn", "");
        Htmlstring = HttpContext.Current.Server.HtmlEncode(Htmlstring).Trim();

        return Htmlstring;
   }
}

5.過濾 Sql 字元

public static bool CheckBadWord(string str)
{
    string pattern = @"select|insert|delete|from|count(|drop table|update|truncate|asc(|mid(|char(|xp_cmdshell|exec   master|netlocalgroup administrators|net user|or|and";
    if (Regex.IsMatch(str, pattern, RegexOptions.IgnoreCase))
    {
        return true;
    {
    else
    {
        return false;
    }
}
public static string Filter(string str)
{
    string[] pattern ={ "select", "insert", "delete", "from", "count\(", "drop table", "update","truncate", "asc\(", "mid\(", "char\(", "xp_cmdshell", "exec   master", "netlocalgroup administrators", "net user", "or", "and" };
    for (int i = 0; i < pattern.Length; i++)
    {
        str = str.Replace(pattern[i].ToString(), "");
    }
    return str;
}

6.SQL字串過濾函數：

public static bool ProcessSqlStr(string Str)
{
    bool ReturnValue = true;
    try
    {
        if (Str.Trim() != "")
        {
            string SqlStr = "exec|insert+|select+|delete|update|count|chr|mid|master+|truncate|char|declare|drop+|drop+table|creat+|create|*|iframe|script|";
            SqlStr += "exec+|insert|delete+|update+|count(|count+|chr+|+mid(|+mid+|+master+|truncate+|char+|+char(|declare+|drop+table|creat+table";
            string[] anySqlStr = SqlStr.Split('|');
            foreach (string ss in anySqlStr)
            {
                if (Str.ToLower().IndexOf(ss) >= 0)
                {
                ReturnValue = false;
                break;
                }
            }
        }
    }
    catch
    {
        ReturnValue = false;
    }
    return ReturnValue;
}

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C#過濾sql特殊字串的方法

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