Hi Bénoni,
Getting the source of your JavaScript code is always possible - no
matter what tricks you apply. Denying right-click, hover over or
whatever else you can think of will not save your code from prying eyes.
After all , the code is transmitted in clear text between you and the
server . You can use many applications (apart from browsers) to get the
source - see Achilles for example. Hiding your JavaScript sources
however, should not be your concern.
JavaScript is a CLIENT-side scripting language. It is getting
interpreted on the CLIENT side. And client=attacker. The attacker has
full control on any code that is executed on his PC. So, the attacker
can easily just skip your JavaScript checks and here you are with
unverified input. You don't need to see/analyze the validation checks
when you can just skip them :)
You cannot provide security through JavaScript. It is only used to
provide convenience to your 'legal' visitors. Your server-side .ASP
scripts should NEVER rely on client-side input validation. Big No-No here.
Instead, you should verify the input inside your .ASP scripts, on the
server side. Validate them, as there is no client-side checking at all -
there is really none, from the attacker's point of view.
Regards,
tie
Bénoni MARTIN wrote:
Hi list !
I was wondering how to solve the 2 following problems: I have ASP (not ASP.NET)
formulaires people have to fill in. To avoid SQ injection attacks and other
tricks, I have set up some Jscript filtering on each field (i.e. for instance a
name can just be alphabet's characters and no figures :) ), and I am planning
to do the same on my Database (setting up constraints).
But I have 2 questions:
- How can I hide my Jscript filtering from the user ? When I want to see the
source, everything is diaplayed, quite normal :( ... Maybe it's not so good to tell
people what I have done to filter them :) I saw some sites where it is impossible to see
the source, impossible to "hoover the site", impossible even to print ... But I
have not been able to find on the net how to do this :(
- How can I deal with possible SQL errors within an ASP page ? I mean, if a field
has been filled in, bypass my Jscript filtering (no matter how), and gets to the database
but is then "stopped" by an SQL onstraint, how do I raise this error on an ASP
page without diplaying an explicit error (giving the user the name of my database for
instance) ?
Cheers for any clue, I am lost on this topic :(
