Re: Gmail and China's GFW

[Cal Leeming <cal () foxwhisper co uk>]

Agreed ;p

On Mon, Mar 21, 2011 at 10:19 PM, bk <chort0 () gmail com> wrote:

> On Mar 21, 2011, at 1:43 PM, Cal Leeming wrote:
>
>
>
> On Mon, Mar 21, 2011 at 8:39 PM, bk <chort0 () gmail com> wrote:
>
> > On Mar 21, 2011, at 10:52 AM, Alien Chatter wrote:
> >
> > > $ sudo iptables -I INPUT -m string --algo bm --hex-string
> > '|476f6f676c6520496e63311830160603550403140f6d61696c2e676f6f676c652e636f6d30819f30|'
> > > -j DROP
> > >
> > > Try it, you will get a connection timeout:
> > >
> > > $ curl --connect-timeout 60 https://mail.google.com/
> > > curl: (28) SSL connection timeout
> > >
> > > The same applies for Twitter, Facebook... Much more efficient than
> > > DNS/IP blocking!
> >
> > Because searching for a bytestring in payload generates so much less load
> > than just overriding a DNS result at the recursive server (that users are
> > forced to issue queries to) or a simply drop SYNs based on IP header value
> > that routers/firewalls are optimized for...
> >
> > I think you forgot your coffee this morning.  It's not just for aliens you
> > know.
> >
> > --
> > chort
> >
> > _______________________________________________
> > Full-Disclosure - We believe in it.
> > Charter: http://lists.grok.org.uk/full-disclosure-charter.html
> > Hosted and sponsored by Secunia - http://secunia.com/
>
> I think what he meant by efficient, was that if their sites ever get
> re-numbered or more end nodes are added (which may or may not be that
> often), then this would still catch the connections.
>
> Imho, I think it'd be better to just have a script checking for it, but
> nether the less, it's a cute approach (albeit, probably not usable in a
> production environment).
>
>
> It's "efficient" in that humans get to be lazy.  It's not efficient as far
> as hardware resource utilization.
>
> --
> chort
_______________________________________________
Full-Disclosure - We believe in it.
Charter: http://lists.grok.org.uk/full-disclosure-charter.html
Hosted and sponsored by Secunia - http://secunia.com/