Quick & Dirty test of the ciphering functions

historical

On Thu, Sep 24, 2009 at 02:13:45AM +0200, Sylvain Munaut wrote:
> This patch is not for merge since it's a gross hack just 'to see if it
> works', and it does ! ( See the log in attachment )

sure, but it's good to know the infrastructure in OpenBSC works...

> The included patch uses A5/2 but can be trivially modified for A5/1. I
> just wanted to see if the iPhone would accept A5/2 and it doesn't
> (works with A5/1 tough) ! My old Ericsson T610 takes A5/2 and A5/1.

The iPhone should then also indicate the lack of A5/2 support in the classmark
values...

> I'm not sure what's the best solution to get SRES and Kc. Most of the time
> getting the Ki is not an option, so either we have a fixed RAND, or a bunch
> RAND and corresponding SRES and Kc ... Or a side channel to run the algo on
> the phone itself ...

Well, I presume if you want OpenBSC with encryption support, then you will
probably either

1) connect to a real-world MSC (with holgers new MSC/BSC split) and HLR
   This is the case where you actually want to deploy a network that
   interoperates with a public network.  Don't be surprised, some companies
   are considering this, and work is being doe in this direction.

2) issue your own SIM cards, where you know the Ki.  This is likely the case
   when you operate a small private network.  In this case we would simply
   store the Ki in our SQL tables.

The latter case is what we can test relatively easy by using the '16in1' SIM
cards as Dieter has indicated some time ago.  I've bought a couple of those,
but am too busy right now. Anyone interested to complete our crpyto
implementation can also easily get them for very little money.

Regards,
-- 
- Harald Welte <laforge at gnumonks.org>           http://laforge.gnumonks.org/
============================================================================
"Privacy in residential applications is a desirable marketing option."
                                                  (ETSI EN 300 175-7 Ch. A6)