Problem solve
Get help with specific problems with your technologies, process and projects.
Protect against SQL Injection by whitelisting
OK, admittedly the best practice for guarding against SQL Injection attacks is to white-ist acceptable characters. However, given that knowledge is power, is there a comprehensive list of special characters (such as the single-quote or double-hyphen) available for SQL Server? I have done a ton of searches and can't seem to find one (I did find the reserved words).
OK, admittedly the best practice for guarding against SQL Injection attacks is to white-list acceptable characters. However, given that knowledge is power, is there a comprehensive list of special characters (such as the single-quote or double-hyphen) available for SQL Server? I have done a ton of searches and can't seem to find one (I did find the reserved words).
SQL is such a powerful language (some would say too powerful) that there isn't a really good list to use for blacklisting. You're right on the money, that whitelisting is your first line of defense. I always like to use a RegEx function to filter all my user provided input. If the data passes the RegEx, then I pass it through a very simple blacklist function as a just-in-case. To date, I haven't seen anything in any application I've written that ever fired off the blacklist function because the whitelist is much more powerful. Whitelisting isn't as hard as you may think; a bunch of examples of RegEx in ASP and PHP abound and you can get really great examples of RegEx strings at
www.regexlib.com.
