过滤SQL关键字，防止SQL注入
定义一个方法进行关键字的过滤，方法中使用正则表达式过滤：
///
/// 过滤字符串中注入SQL脚本的方法
///
///传入的字符串
///过滤后的字符串
private static string SqlFilters(string source)
{
//半角括号替换为全角括号
source = source.Replace("'", "'''");
//去除执行SQL语句的命令关键字
source = Regex.Replace(source, "select", "", RegexOptions.IgnoreCase);
source = Regex.Replace(source, "insert", "", RegexOptions.IgnoreCase);
source = Regex.Replace(source, "update", "", RegexOptions.IgnoreCase);
source = Regex.Replace(source, "delete", "", RegexOptions.IgnoreCase);
source = Regex.Replace(source, "drop", "", RegexOptions.IgnoreCase);
source = Regex.Replace(source, "truncate", "", RegexOptions.IgnoreCase);
source = Regex.Replace(source, "declare", "", RegexOptions.IgnoreCase);
source = Regex.Replace(source, "xp_cmdshell", "", RegexOptions.IgnoreCase);
source = Regex.Replace(source, "/add", "", RegexOptions.IgnoreCase);
source = Regex.Replace(source, "net user", "", RegexOptions.IgnoreCase);
//去除执行存储过程的命令关键字
source = Regex.Replace(source, "exec", "", RegexOptions.IgnoreCase);
source = Regex.Replace(source, "execute", "", RegexOptions.IgnoreCase);
//去除系统存储过程或扩展存储过程关键字
source = Regex.Replace(source, "xp_", "x p_", RegexOptions.IgnoreCase);
source = Regex.Replace(source, "sp_", "s p_", RegexOptions.IgnoreCase);
//防止16进制注入
source = Regex.Replace(source, "0x", "0 x", RegexOptions.IgnoreCase);
return source;
}当然也可以添加自己想要的过滤正则，下面加入一个方法调用并返回过滤后的字符串：
///
/// 防注入过滤函数
///
///需要过滤字符串
///过滤后的字符串
public static string Filter(string inputString)
{
if (inputString != ""&&inputString!=null)
{
string sql = SqlFilters(inputString);
if (sql == "")
{
sql = "敏感字符";
}
return sql;
}
else
{
return inputString;
}
}在我们做web开发的过程中，Web安全问题一直都是最大的隐患，互联网的繁荣离不开网络安全，这是我们的机遇也是我们的挑战。