Tweaking my search functionality

Question

I have tested search functionality i have implemented on a live website. I came across some small issues. I can't put special characters in the search box or my application will crash. I tried to solve this using some replaces on the characters it crashes on, but this won't cure the pain. When i entered this sign: * into the searchbox it gave me the following error:

Cannot parse '<%%> echo;': '' or '?' not allowed as first character in WildcardQuery. I have had this error before and then stripped the spaces between all words. The error was then gone. However when i now replace this: * with this: "" i will get the error described above. Is there any standard way i can solve the special character issue with? I'll write down some of my code here, so i can get better feedback.

Analyzer analyzer = new StandardAnalyzer();
QueryParser qpContent = new QueryParser(Index.ContentFieldName, analyzer);
keyword.Trim();

keyword = keyword.Replace("\"", "");
keyword = keyword.Replace("^", "");
keyword = keyword.Replace("*", "");

Query queryContent = qpContent.Parse(keyword + "*");              
QueryParser qpLanguage = new QueryParser("language", analyzer);
Query queryLanguage = qpLanguage.Parse(Sitecore.Context.Language.Name.ToString());

As you see i first replace * and then later on add it back in the queryparser. I'm not 100% familiar with this kind of functionality and therefore have no clue at all what i'm doing wrong. All help is much appreciated, thanks!

Answer 1

you may have the ValidateRequest option set in your config, this helps to protect against Injection Attacks in asp.net.

Some details can be found here...

http://msdn.microsoft.com/en-us/library/bb355989.aspx

http://msdn.microsoft.com/en-us/library/system.web.configuration.pagessection.validaterequest.aspx

and...

http://en.wikipedia.org/wiki/Code_injection

http://en.wikipedia.org/wiki/SQL_injection