On 24/07/10 19.30, Harald Welte wrote:
> Please focus your scarce resources where it is really needed...
>   

Harald, i think that you are absolutely right however let me say that
doing r&d in telephony it's really a pain and it's a kind of knowledge
not very widespread into the hacking community.
Usually that's more considered like a techie stuff for TLC experts,
radio frequency, difficult protocol to deal with, closed hardware, legal
issues and so the environment it's still not knowledgeable enough.
Few hackers i know, know what TCH or GPRS Reliability class mean.

The entrance barrier (due to telco technology lobbying) to play with
those stuff was very high and you and all you guys have the very great
and fantastic merit to have opened this environment by providing the
building-blocks of software and hardware interaction to play with it.

I would like to try to summarize what i understood of the situation and
status of the projects and propose some ideas.

If i got the point, now we are in a stage where the various technologies
require final improvement (from networking side) and different pieces of
various projects could be reused for such improvements, particularly for
airprobe.

>From outside, trying to deal with the various projects, the feeling is
that is still a quite disperse set of projects.
At 1st attempt it's still quite difficult to understand which are the
pieces of the puzzle and how to make what you want to do.
That's not easy like playing with the WiFi hacking stuff .

People will get crazy when GSM hacking will become something similar to
WiFi hacking, in practical term, and more people involved and more
people acquiring knowledge on that stuff but at higher level. :-)
But security people that want to play with a51 stuff just for security
(not being tlc protocol experts) before investing money to buy the
hardware typically want to be sure to be able to use it.

Still some not major but very important works (compared to previous
activity) need to be done to reach that stage (i mean respect to people
using it only for security playground without having to know the wide
GSM protocol stacks in details).

>From what i understood of the various pieces (pls correct me if i am wrong):
@ OpenBTS is a BTS software hooked directly (no BSC support )with
Asterisk for telephony service, that works with USRP1
@ Airprobe is GSM network sniffer whose oline documentation refer to USRP1
@ OsmocomBB provide:
  - Baseband processor firmware including all gsm layers protocol stack
implementation (cool!)
  - Radio driver that's compatible with certain Motorola, Sony Ericsson
and and OpenMoko
@ OpenBSC is a Base Station Controller (BSC) to be used with BTS Siemens
BS11 microBTS and ip.access nanoBTS and require an E1 telephony card for
interconnection
@ A5/1 Security project make the software for cracking by generating and
using rainbow tables (recently improved by Frank Stevenson). It has been
reported that it worked (with airprobe?) with two USRP2 units (but no
public technical setup instruction).
@ A5/1 Rainbow tables in size of 2TB are ready and already available to
several people in the community

Do i got the point or i am missing / misunderstood something?

So to summarize, from what i understood, to make the gsm cracking
working in real-world environment we still miss:

@ Improvement of Airprobe monitoring software (proper demodoulation) to
stay up with recording long call and properly following channels (Part
of it getting improved by Sascha, part by Piotr?)
@ A first full howto on detailed setup hw/sw instruction for a working
setup to let ppl start with higher level hacking (should come from
Karsten at BH next week?)
@ A community / system for Rainbowtable distribution that can scale-up
to hundreds of users

Do i understood properly or there's something else?

Below some ideas about that.

@ About missing code of airprobe / other tools?
Regarding what's still missing, would it reasonable also to provide
something bounties like "Google summer of code" for specific features /
module?
I mean, it's true that voluntary based development it's the best things
but providing some economic incentive for opensource development always
help, also getting smart young ppl on-board (you do something fun and
challenging and earn some money for holidays).
We can arrange some fund raising to support also a bounty based
development program on the projects.
In past i organized oss development funding with osxcrypt.org project
and in 2 days collected 1500USD among the security community. Probably
we can get much more.
Does this could be an approach that help?

@ About documentation
I am available to come for a weekend with the proper hardware (within
Europe), together with who have the deep project knowledge prepare a
setup from scratch, by writing in the meantime the documentation for the
hw/sw setup for who don't know anything about the internals/details of
the projects but want to start playing with it.
It's summer and a weekend of hacking it's always a pleasure :-)
That's still a critical point today imho, to let people (like me that
know about protocols and security but are not hardcore low-level code
hacker) start playing with it at higher level.

@ About rainbow table distribution
I just wrote to the guys of freerainbowtables.com for availability of
hosting the tables (they are already hosting 1700GB of tables) and
providing hard disk distribution like they are already doing. Let's see
if they're available.

Eventually we also can try to organize a "hard disk distribution process
distributed".
We can make a "call for hard disk distributors" to get people providing
the availability to manage hard disk distribution process , at least one
for each continent / country (that way we can avoid custom duties and
let ppl just handle the shipping burocracy).
The cost depend on the person distributing the hardisk and can be in
it's own currency.
Money get collected on single paypal account and then are forwarded to
the distribution point chosen or payment are done directly to the
distribution person paypal account, that's near to the requester to
distribute the table.
People buying the hard disk with tables could be invited to join the
distribution network.
Additionally we can make an online lists of who have the tables / where
lives (city) in order also to easily provide face-to-face distribution
(i am in Milan, if someone from Venice need it, probably can just get a
car, come to me bringing an hard drive and start cloning it).
Bittorrent is fine, but 2TB are still a lot of data to be downloaded.
An hard-disk-distribution-protocol that's high-latency but an
high-bandwidth along with a web tool to handle the protocol could help.

I am trying to find out what can be done to provide support not being an
hardcore low-level coder, also to get a big picture of the overall
opensource gsm coding and hacking projects as the community is still
very small and it need to grow with supporters.

-naif
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