C#实现过滤sql特殊字符的方法集合

2019-10-29 21:36:43

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这篇文章主要介绍了C#实现过滤sql特殊字符的方法,以实例形式分析总结了C#针对SQL危险字符的几种常用的过滤技巧,非常具有实用价值,需要的朋友可以参考下

本文实例讲述了C#实现过滤sql特殊字符的方法集合。分享给大家供大家参考，具体如下：

/// <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("&", "&");

Str = Str.Replace("<", "<");

Str = Str.Replace(">", ">");

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 SqlFilter(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;

}

/// <summary>

/// 过滤标记

/// </summary>

/// <param name="NoHTML">包括HTML，脚本，数据库关键字，特殊字符的源码 </param>

/// <returns>已经去除标记后的文字</returns>

public string NoHtml(string Htmlstring)

{

if (Htmlstring == null)

{

return "";

}

else

{

//删除脚本

Htmlstring = Regex.Replace(Htmlstring, @"<script[^>]*?>.*?</script>", "", RegexOptions.IgnoreCase);

//删除HTML

Htmlstring = Regex.Replace(Htmlstring, @"<(.[^>]*)>", "", RegexOptions.IgnoreCase);

Htmlstring = Regex.Replace(Htmlstring, @"([/r/n])[/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);

//删除与数据库相关的词

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);

//特殊的字符

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("/r/n", "");

Htmlstring = HttpContext.Current.Server.HtmlEncode(Htmlstring).Trim();

return Htmlstring;

}

}

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;

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;

}