Identifying the presence of illegal characters

[mike55]

Good morning all,

 

We have a procedure that requires us to validate all input for text fields; if the input contains certain characters or key words, we must force the user to re-enter alternative data. Some of the characters that we look for at the start of sentances are:

' ;

/ >

-- <

admin @

declare =

 

Some of the characters that we look for at the end of sentances are:

one

>

 

The keywords that we look for are:

@@ xss

__ (double underscore) NULL

varchar ‘’ (double single quote)

ascii ';

cursor exec (followed by space)

-- char(

src

 

I have added the regular expression validator to my web page and have entered the following custom validator:

^'|^;|^/|^>|^--|^<|^admin|^@|^declare|^=|one$|>$|@@|xss|__|null|varchar|''|ascii|';|cursor|exec |--|char|src

 

The validator does not fire for any of my illegal characters, how can I set the above custom validator to "not equals"? I know that I can use the Regex.IsMatch function within the code, but thought that by using the regular expression control may be safer.

 

Mike55.

Edited November 2, 2009 by mike55