Subject: Wireless Networks and happy-happy encryption
To: Catastrophe, Joe


OK. So I'm sitting there looking at the file on my laptop detailing
the key for your home network, and finally curious enough to solve the
problem once and for all.


Say, hypothetically, I knew a four-letter key for a wireless
network, somewhere. And that I wanted to know what that was in it's
hex 104-bit format, so I could use it on my Airport card on my mac, or
my {whatever} card on my linux laptop. Purely hypothetical situation.

Would you believe, the correct answer is "there is NO way to do this".

It turns out that basically, every manufacturer has their own hashing
codes. a Linksys router could take "ChKs", and turn it into one
particular 104-bit key. And a Cicso router could take exactly the same
4 letters and turn it into a completely different 104-bit key.

Bastards.

It turns out that what we were missing all along was two pieces of
information, painfully obvious now I think about it:

Except for my linux box and James' mac, all your wireless networking
hardware is completely homogenous. Your router's a LinkSys. All your
network cards are made by LinkSys. Your AP's a LinkSys. They all have
drivers that understand LinkSys' hashing algorithm. Every item on
your network, independantly, takes your 4-letter code and turns it
into a 104-bit key using a secret algorithm, that linux doesn't know,
and that OSX doesn't know.

The other piece of information it seems, is that the f**king thing puts
the 104-bit hex key on it's admin page.
You type in the plaintext key in the webby interface, and it shows it
to you in a suitable fashion for putting into anything that's not a
linksys. I've not seen this because I never saw your WAP interface.
I never actually saw the page, on the access point, where you're shown
the key. Hence, it never caught my attention.

Bastards. All of them.

Just for future reference, there.

I've also discovered that your wireless router is admin-able via SNMP
[I believe]. In plain English, there's an app you can download for windows
[and linux and OSX, it seems] that DOESN'T use the web interface on the
router - but lets you administer it without plugging USB cables in the
back, by going over SNMP [simple network management protocol].


Well, children, that's the end of today's lesson, and I hope that you
all avoid using some of the colorful language I came up with when I
worked all this out, since it's not polite.

Gary (-;