本文小编为大家详细介绍“C#如何过滤sql特殊字符串”，内容详细，步骤清晰，细节处理妥当，希望这篇“C#如何过滤sql特殊字符串”文章能帮助大家解决疑惑，下面跟着小编的思路慢慢深入，一起来学习新知识吧。
1.过滤不安全的字符串
/// <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;
}2.过滤 Sql 语句字符串中的注入脚本
#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;
}
#endregion3.过滤SQL字符
/// 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;
}4.过滤标记
/// <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;
}
}5.过滤 Sql 字符
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字符串过滤函数：
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;
}读到这里，这篇“C#如何过滤sql特殊字符串”文章已经介绍完毕，想要掌握这篇文章的知识点还需要大家自己动手实践使用过才能领会，如果想了解更多相关内容的文章，欢迎关注亿速云行业资讯频道。
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