Re: [NSE] DB2 library and scripts

[Patrik Karlsson <patrik () cqure net>]

On 14 maj 2010, at 09.23, Patrick Donnelly wrote:

> Hi Fyodor,
>
> On Wed, May 12, 2010 at 2:01 PM, Fyodor <fyodor () insecure org> wrote:
> > On Wed, May 12, 2010 at 05:33:30PM +0200, Patrik Karlsson wrote:
> > > I think this is a great idea. Perhaps this could be considered,
> > > when/if implementing a more generic brute force framework as proposed
> > > by Martin Swende [1] ?
> >
> > I agree that a brute force library/framework or is the way to go,
> > especially as the scripts get more complex due to parallelisms and
> > algorithm optimizations.
> >
> > That being said, it sometimes is easiest to start with one script and
> > experiment/benchmark to figure out what works best.  Then that can be
> > ported to a new generalized library.  In other cases (or for other
> > people), starting with the generalized library is easier.
>
> It seems to me this is something best handled in the NSock Lua
> binding. That is, if a server is "misbehaving" by slowing down replies
> or dropping connections then we should lower the parallelism against
> the server? This is probably too low level though.
>
> That said, I'm curious why the parallel implementation performed so
> poorly. Patrik, do you know how the server was reacting? Was it
> dropping connections? Slowing down replies? How does your db2.lua
> library handle dropped connection attempts? Does it retry?
First off, like I mentioned before, this is a server running in VirtualBox on my laptop.
Secondly, this is a default installed DB2 server without any tweaking made on the OS or the DB.
So it probably doesn't server well as a testing reference.

While running the script against the server the CPU goes up to 70% and stays there for the complete duration of the 
scan.
Even though it's not 100% I'm guessing this is what's limiting it from going faster.

I've added some missing checks for socket errors in the library, but no retry attempts are made.
I would appreciate it a lot if someone with a "real" db2 server could test it out and report some performance 
statistics.

> -- 
> - Patrick Donnelly
> _______________________________________________
> Sent through the nmap-dev mailing list
> http://cgi.insecure.org/mailman/listinfo/nmap-dev
> Archived at http://seclists.org/nmap-dev/


//Patrik

--
Patrik Karlsson
http://www.cqure.net
http://www.twitter.com/nevdull77





_______________________________________________
Sent through the nmap-dev mailing list
http://cgi.insecure.org/mailman/listinfo/nmap-dev
Archived at http://seclists.org/nmap-dev/