using Microsoft.AspNetCore.Http;
using System;
using System.Collections.Generic;
using System.Text;
using System.Text.RegularExpressions;

namespace CommonToolsCore
{
   public class SqlFilter
    {
        /// <summary>
        /// 过滤不安全的字符串
        /// </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;
        }

        #region 过滤 Sql 语句字符串中的注入脚本
        /// <summary>
        /// 过滤 Sql 语句字符串中的注入脚本
        /// </summary>
        /// <param name="source">传入的字符串</param>
        /// <returns>过滤后的字符串</returns>
        public static string SqlFilterFilter(string source)
        {
            //单引号替换成两个单引号
            source = source.Replace("'", "''");
            //半角封号替换为全角封号，防止多语句执行
           // source = source.Replace(";", "；");
            //半角括号替换为全角括号
            source = source.Replace("(", "（");
            source = source.Replace(")", "）");
            ///////////////要用正则表达式替换，防止字母大小写得情况////////////////////
            //去除执行存储过程的命令关键字
            source = source.Replace("Exec", "");
            source = source.Replace("Execute", "");
            //去除系统存储过程或扩展存储过程关键字
            source = source.Replace("xp_", "x p_");
            source = source.Replace("sp_", "s p_");
            //防止16进制注入
            source = source.Replace("0x", "0 x");
            return source;
        }
        #endregion

        /// 过滤SQL字符。
        /// </summary>
        /// <param name="str">要过滤SQL字符的字符串。</param>
        /// <returns>已过滤掉SQL字符的字符串。</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;
        }

     
    }
}