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C#过滤sql特殊字符串的方法

2022-08-23 05:01:28

C#过滤sql特殊字符串的方法

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("&", "&amp"); Str = Str.Replace("<", "&lt"); Str = Str.Replace(">", "&gt"); 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; } #endregion

3.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; }

到此这篇关于C#过滤sql特殊字符串的文章就介绍到这了。希望对大家的学习有所帮助，也希望大家多多支持易知道(ezd.cc)。

字符串过滤方法不安全字符

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