Symbian is Open Soruce - Really?
In recent news, the Symbian Foundation announced that "All 108 packages
containing the source code of the Symbian platform can now be downloaded from
Symbian's developer web site". This is great news!
This morning I tried to look at the parts most interesting to me: phonesrv
(implementing call engine, cell broadcast and SIM toolkit APIs) and poc
(implementing push-to-talk). Their pages don't have the usual "source code"
tab at the bottom right which links to mercurial and tarball download pages!
Either I'm too stupid, or I am unable to find any source code for those two
components. I'm quite sure something essential like the API's for making phone
calls are considered part of the Symbian platform. So how does that match
with the statement that all packages containing the Symbian platform can now
be downloaded?
[ /gsm |
permanent link ]
Sorry for new blog updates
I've been busy day and night, hacking away on my latest pet project in the GSM
field. In fact, it's been a long time since I've been able to dedicate so
much time and energy into one particular project, without many distractions at
all. The project is now finally looking quite promising and making nice
progress throughout the last three weeks.
If progress continues, I hope in another week I'll be able to reveal what this
is all about. I haven't felt this level of excitement since the early days of
Openmoko :)
[ /gsm |
permanent link ]
Illusions about MagicJack at CES
Many people have pointed out the MagicJack Femtocell product that has been announced at CES. I cannot really understand the big hype and news about it. Why? read further...
On the technical side, there is hardly anything new. Using projects like
OpenBTS or OpenBSC, you can run your own GSM network and connect it to VoIP.
Sure, the retail price of the MagicJack is much lower, but that's the economics
of scale. As soon as OpenBSC support for one of the recent femtocells is done,
we also have a much lower cost solution to the same problem.
On the legal and business side, I can see many problems for MagicJack:
- To operate equipment in the GSM or 3G spectrum, you need a license. Since
a nationwide GSM operator license is very expensive in about any country of the
world, it is economically not an option. Selling the MagicJack devices without
a license and leaving the spectrum license to the user will not work, or at least
not long, since regulatory authorities and commercial operators are not going to
let anyone deploy systems that interfere with their networks.
-
If you keep the Operator's SIM in the phone, and use that SIM on your own
network you might at least violate the terms of services of the operator. The
SIM card normally belongs to the operator, and it is part of the users business
relationship with that operator. As such, you can not really use it with other
networks. Sure, if you do this at home with your OpenBTS/OpenBSC installation,
nobody will care. But if somebody is doing this commercially, and in a way
that affects the sale of talk time of the regular operators, again it will not
take long until the commercial operator will sue you.
-
Security. If you run your phone with a "foreign" SIM, you do not know the Ki
on the SIM and thus cannot do cryptographic authentication and/or encryption.
This is a big security issue. It is once again not an issue in your personal
testbed setup, but it is going to be one if you do this at large scale as a
mass market product.
So, as you can see: It's neither technically something exceptionally new,
nor is it something that has a very promising business or legal outlook. The
only way how a product like this would work is if it is authorized by the
respective operator. But why would the operator authorize something that will
take talk time away from his network and thus his revenue stream?
[ /gsm |
permanent link ]
Planning for a GSM development board
I've finally found enough spare time to work on detailed plans for a GSM
development board. The idea here is to have a 100% open hardware design
with 100% free software that provides an inexpensive platform for GSM
related R&D.
Initially the focus is on having a board that can behave like a GSM cellphone,
next steps would be to have a multi-channel frequency-hopping receiver, and
finally the option of using it as a BTS.
The idea is fairly simple: Take a commercial off-the-shelf analog baseband and
RF circuit for GSM and attach it to a general purpose DSP, add some glue logic
and go ahead. But the devil is in the details:
- You want something where you can still find the parts on the market, but
which still has sufficient leaked documentation that you can write an open
source driver for it.
- The requirements for a MS and a BTS are quite different. A phone never
needs to continuously receive and transmit in all timeslots, e.g.
- The requirement for a multi-channel frequency-hopping receiver is mainly a
high number of receiver circuits, so the solution needs to scale to a larger
number of receivers.
- The analog baseband circuits often have quite obscure control interfaces
which need to be driven. Custom peripherals in programmable logic (CPLD/FPGA)
are required.
- The TDMA nature has strict timing requirements. Normal processors and
software-based mechanisms are not sufficient to trigger the required events
and their sequencing at a high enough precision.
Anyway, there is sort of a first plan now, and the next weeks and months will
be spent with refining the plans and building a first proof-of-concept
prototype. Once that has proven to work, we want to go ahead with finishing
the design for a real board, to be manufactured in sufficient quantities for
interested parties.
Unless you have worked in GSM phone or base station hardware design or have a
similar level of EE and DSP skills, please refrain from contacting me right
now about how to join the project. We want to focus on getting things going
first, then make a public release at a point where there is something that
works sufficiently well that we can support a larger community of developers.
[ /gsm |
permanent link ]
2010-01-02 / 2pm CET: Radio Interview at Deutschlandradio
The German radio station Deutschlandradio Kultur has invited
Constanze Kurz (46halbe) and myself for interviews during today's Breitband
radio show. We'll be talking about the 26C3, the Chaos Computer Club and -
of course - GSM [in]security.
[ /gsm |
permanent link ]
OpenBSC now has handover support
So far, OpenBSC already implemented mobility management, i.e. keeping track of
which location area a mobile phone is locate in. However, this only works during
idle mode, i.e. while there is no actual phone call in progress.
Throughout the last week, I've been working on getting real handover support
into OpenBSC. This is now actually working very well! You can move from one cell
into another cell while your phone call continues just like it is supposed to do.
The signalling part is actually not all that hard to implement. However,
it has some dependencies on things like measurement reports, which in turn
require us to send proper neighbor lists, which in turn requires proper
generation of system information messages, etc.
The actual order of events in a successful handover case is as follows:
- OpenBSC send the neighbor cell information in the BCCH and SACCH
- OpenBSC regularly receives measurement reports from the phone, where it tells us how well neighbor
cells are being received. OpenBSC then averages those measurements and decides
if or not to make a hand-over. If it decides so, it
- allocates a channel on the new BTS
- waits until the BTS acknowledges this
- sends a HANDOVER COMMAND to the phone through the old BTS
- waits for HANDOVER ACCESS bursts and a HANDOVER COMPLETE on the new BTS
- closes the old channel on the old BTS
- takes care of re-routing the voice channels
As indicated, the signalling part was relatively easy, and once the measurement
processing and neighbor lists were in place, this worked really quick. What
turned out to be a much bigger PITA was the handling of the actual voice
streams.
Let's assume you have a call from A to B, where B is changing cells and now becomes B*.
In this case, after switching cells, the speech frames from A need to be re-routed to B*
instead of B. That's simple and works very easy. In the other direction, switching
off B is easy. However, a completely new channel B* suddenly sends speech
frames to A. In case of classic TRAU frames on E1 that is simple as they don't have
any context.
In the case of ip.access nanoBTS, the speech frames are transported using RTP.
Changing the source of your stream will change its CSRC (synchronization source
identifier), timestamps and sequence numbers. The receiver in BTS A is not
happy at all about this. So with handover, it is no longer possible to send RTP
streams directly between BTS's, but OpenBSC's RTP proxy needs to process the
RTP packets and hide the details of the changed source.
This is further complicated by the fact that during handover you are losing
speech frames, somewhere between 10 and 40 in the cases that I've seen. This means
that when sending the new RTP frames from B*, the sequence number and timestamp
needs to account for those lost frames, i.e. incremented by the respective loss
count. Otherwise the RTP receiver in BTS A will think it is only receiving old
frames and will discard all of them.
Luckily, all of this seems to have been sorted out now and I'm confident we will
have actual full handover at the GSM network at 26th annual Chaos Communication
Congress in a few days from now. We'll be running 3 BTS's with a total number
of 5 TRX's inside the conference building.
[ /gsm |
permanent link ]
German Constitutional Court hearing on data retention law
Today I've taken one day off work in order to attend the publich hearing
of Germany's constitutional
c ourt on several constitutional complaints against a German national law
on data retention of telecommunications data. As the topic is likely only
relevant to Germans, and due to the fact that I am not very confident with
my English legalese outside of copyright law, I'll switch to German for
this blog post - which I believe is unprecedented in this blog so far.
Tja, da war ich also heute einer der wenigen auserkorenen Besucher beim
BVerfG. Immerhin haben mehr als 34.000 Leute Verfassungsbeschwerde eingelegt,
auch wenn rein formal heute nur eine Hand voll exemplarische Beschwerden
verhandelt wurden. Diesen Trick hat sich das BVerfG wohl ausgedacht, um nicht
vor dem Problem zu stehen dass jeder Beschwerdefuehrer sicher ein Recht haette,
persoenlich vor Gericht anwesend zu sein.
Der Gerichtssaal des BVerfG ist sehr klein. So klein, dass bei besonders
bedeutungsvollen Verfahren kaum mehr Platz fuer Besucher ist. Der eigentliche
Gerichtssaal war schon durch die Beschwerdefuehrer, die zahlreichen Vertreter
des Gesetzgebers und der Behoerden und Amstraeger (BKA, Polizeipraesidenten,
Richter an diversen Gerichten, Bundes- und Landesdatenschutzbeauftragte,
Mitglieder des Bundestags und nicht zuletzt die zahlreichen wissenschaftlichen
Mitarbeiter des Bundesverfassungsgerichts selbst belegt. Hinten waren noch zwei
Reihen fuer Besucher frei.
Diese beiden Reihen wurden durch Studentengruppen belegt - oder vielleicht
koennte man fast sagen "verschwendet". Ein nicht unerheblicher Teil dieser
Studenten (u.a. der TU Darmstadt) hatte tatsaechlich geschlafen. Was fuer eine
Ungeheuerlichkeit, nicht nur ein Mangel an Respekt gegenueber dem hoechsten
Gericht des Landes und dem Thema gegenueber - sondern auch eine
unverschaemtheit gegenueber den vielen vmtl. hunderten von interessierten
Buergern die gerne der Verhandlung beigewohnt haetten, aber einfach keinen Platz mehr bekommen haben. Freunde von mir haben am 2. Tag nach der Terminankuendigung
versucht noch einen Platz zu bekommen - vergebens.
Da haben wir also die nahezu perverse Situation, dass das hoechste Gericht zwar
faktisch von jedem Buerger angerufen werden kann, dies auch eine fuenfstellige
Zahl an Buergern wahrnimmt - dann aber die eigentliche Verhandlung nur fuer
eine kleine Elite zugaenglich ist, und Aufzeichnungen oder Uebertragungen nicht
gestattet sind. Das erscheint mir doch irgendwie ungerecht.
Doch nun zur Sache:
Der 1. Senat unter dem Vorsitzenden Richter Papier hat die Anhoerung im
Allgemeinen sehr souveraen geleitet. Es gab ein paar amuesante Momente,
als z.B. die Vertreterin des Justizministeriums das Wort an den
Prozessbevollmaechtigten der Bundesregierung uebergeben hat, obwohl doch das
Gericht normalerweise das Wort erteilt, und nicht andersherum ;)
Wie auch schon bei der letzten Verhandlung: Die Beitraege der geladenen
Sachverstaendigen waren bisweilen der interessanteste Teil, vor allem eben
die diversen Fragen des Gerichts. Diese Fragen erlauben einerseits einen
Blick hinter die Ueberlegungen der Richter - andererseits aber auch in wie
weit die technischen Zusammenhaenge und deren Folgen vom Gericht bereits
verstanden werden. Das jetzt bitte nicht falsch verstehen: Ich habe tiefsten
Respekt vor dem Gericht, und es ist i.d.R. sehr erstaunlich wie weit sich die
Richter in das jeweilige Fachgebiet einarbeiten. Wie auch schon bei der
Verhandlung zu den Wahlcomputern lassen die Vertreter der Regierung bzw. der
untergeordneten Behoerden da oft deutlich weniger umfassende Kenntnisse
durchblicken.
Die ganze Debatte zur VDS (Vorratsdatenspeicherung) ist verzwickt. Wir haben
da historisch einen Bundestag, der keine VDS will, einen Rat der
EU-Innenminister der das dann einfach als EU-Richtlinie beschliesst, und einen
Bundestag, der in Folge die exzellente Ausrede hat, dass er die Richtline ja
umsetzen muesse, um von der EU kein Verfahren angehaengt bekommt.
Die EU-Richtline heisst nun eben auch, dass das BVerfG nun nicht nur in der
Sache zur VDS entscheiden kann, sondern sich eben noch mit der Frage
beschaeftigen muss, was denn passiert wenn eine EU-Richtline mit dem Deutschen
Grundgesetz in Konflikt steht.
Ein paar voellig ungeordnete aber fuer mich bemerkenswerte Punkte der
Verhandlung heute:
-
Es gibt keine empirisch/wissenschaftliche Grundlage die belegt, dass die VDS
zur bekaempfung von Terroristischen Anschlaegen geeignet ist (das war ja nach
Dem 11.9. sowie den Anschlaegen von Madrid und London die Begruendung).
-
Der Chef der Bundesnetzagentur hat mehrfach ganz unuebersehbar nicht auf eine
wiederholte Frage des BVerfG geantwortet: Gibt es Unternehmen, die gesetzlich
zur VDS verpflichtet sind, aber andererseits keinerlei Verpflichtung zur
erstellung oder Abgabe eines Sicherheitskonzepts zur Sicherheit dieser Daten
haben? (Meine Auffassung: Ja, die gibt es!)
-
Die Bundesnetzagentur macht, wie sie selbst sagt, im wesentlichen Pruefungen
der Sicherheitskonzepte am Schreibtisch. Das muss ja mit der Realitaet in den Unternehmen nicht viel zu tun haben.
-
Einer der Beschwerdefuehrer, Minister A.D. Dr. Burkhard Hirsch hat wohl
die lebhaftesten und unverbluemtesten Redebeitraege gehalten; sehr erfrischend.
-
Der Polizeipraesident von Muenchen wurde gebeten, konkret zu begruenden,
wie die VDS der polizeilichen Ermittlungsarbeit in Muenchen hilft. Fast alle
seiner Beispiele waren ungeeignet, da sie auch ohne VDS aber z.B. mittels
einer telefonischen Fangschaltung oder einer Verbindungsdatenspeicherung nach
expliziter Aufforderung durch die Polizei (und nicht auf Vorrat) moeglich
gewesen weaeren. Zwei seiner Beispiele haben sich zudem generell als falscher
Alarm herausgestellt (Journalist macht einn Testanruf; gelangweilter Schueler
kuendigt aus Spass Amoklauf an). Das klang alles eher nach
Stammtischgeschichten als nach fundierter Ermittlungsarbeit in wichtiger Sache.
-
Die Sicherheitsanforderungen an die Speicherung der VDS-Daten ist derzeit
offensichtlich nicht hoeher als an alle anderen Daten innerhalb des
Fernmeldegeheimnisses insgesamt. Also der gleiche Sicherheitslevel, der uns
zu den Datenschutzskandalen wie z.B. bei der Telekom gefuehrt hat. Das ist
ja mal echt vertrauenerweckend.
-
Der Chef der Bundesnetzagentur spricht gerne vom "bill shock", was laut ihm
eine ueberhoehte Telefonrechnung nach unabsichtlicher Nutzung der teuren
Auslandsroaming-Tarife im Mobilfunk ist.
-
Ein kleiner Schmunzler am Rande war dann noch Burkhard Hirsch's "Blueberry", als
er den Blackberry meinte ;) Ja, klar, jeder weiss was er meint und niemand
nimmt es ihm uebel - aber es zeigt einfach, wie unsicher die "alte Garde"
mit den Begrifflichkeiten der heutigen Alltagswelt umgeht.
-
Die qualitaet der Richterlichen Anordnungen laesst offensichtlich sehr zu
wuenschen uebrig. Es ist aufgabe des jeweiligen Richters, einzuschraenken
genau welche Daten denn vom TK-Dienstleister uebergeben werden sollen.
Laut dem Vertreter des Verbands der Internetwirtschaft (eco e.V.) kommen
hier anscheinend recht allgemeine Anordnungen im Stil von "geben Sie uns mal
alles was Sie haben" vor. Das geht so natuerlich nicht!
-
Es kam zur Sprache, dass deutlich mehr Leute jetzt ihre eigenen e-mail Server
betreiben wollen (privat und bei Firmen), weil man sich damit der e-mail VDS
entziehen kann. Ist ja schoen, dass es den Trend gibt, und gut dass das
auch mal auf dieser Ebene zur Sprache kommt. (Fuer mich kaeme etwas anderes
niemals in Frage. Meine Daten gehoeren mir. Ich wuerde weder die Speicherung
meiner Mails noch jeglicher anderer Daten jemals einer anderen Person
anvertrauen, weder einem Privatunternehmen noch einer staatlichen Stelle).
Das ist genau einer der vielen Tricks, mit denen die "digitale Elite" (und
garantiert auch die vermeintlich zu bekaempfende organisierte Kriminalitaet
oder der Terrorismus) arbeitet. Letztlich trifft man dann nur den
Otto-Normalverbraucher, und benutzt die Daten dann fuer harmlose
Beleidungsdelikte oder Urheberrechtsverletzungen im privaten Bereich.
[ /ccc |
permanent link ]
German National Education and Research Network reports on OpenBTS and OpenBSC
Issue
77 of the regular publication "DFN Mitteilungen" of the German National
Research Network (DFN) reports on Open Source
software for GSM networks, specifically OpenBTS and OpenBSC.
I'm happy to see that at least some parts in academia are now discovering this
software and use it for research purpose. That's great news!
[ /gsm |
permanent link ]
GSM and UMTS: The Creation of Global Mobile Communication
There is yet another really exciting book that I've been reading lately: GSM
and UMTS: The Creation of Global Mobile Communication. It's a book on the
history of GSM. From the early days at CEPT, through the creation of ETSI and
the GSM MoU Organization, the 3GPP, ...
It puts the development into historical context, indicates who were the key
participants at that time, political aspects of the European PTTs that
initiated the project, the role of the European Commission, etc.
I've always been looking for this kind of information online anywhere, but
there really is nothing that provides any level of detail. Wikipedia e.g.
has only two paragraphs (which I believe to be even partially incorrect) on
GSM's history. Contrast that with the many writings on the history of the
Internet.
The book is accompanied by a CD-ROM with many old meeting notes and other
documents from the various stages of the GSM development process.
[ /gsm |
permanent link ]
Palm sued over GPL violation in muPDF
As you can see in this techworld post.
Apparently they are using the GPL licensed muPDF library and link it against
their proprietary PDF viewing application. If that is true, then it would be a
very straight-forward, FAQ-type violation. muPDF is not LGPL but GPL licensed,
thus you cannot create derivative works without licensing them under GPL, too.
The whole license management and even software release management at Palm
seems to be very sloppy. For example, based on the object code and disassembly,
I can prove that the source code for libpurpleadapter on opensource.palm.com
does not (or no longer) correspond to the object code that they ship.
What's particularly surprising is that Palm actually is forcing Artifex to go
to court over this issue. You would expect such a straight-forward issue
to be resolved fairly quickly and settled out of court, before it ever escalates
or turns into a PR disaster.
You would expect a company that is regularly building and releasing firmware
images to have an automatic process that packages the source code as part of the
build process. In fact, Palm uses OpenEmbedded to build their images, and it
is a standard feature of OpenEmbedded to create the corresponding source tarballs
for everything it builds.
Furthermore, the Palm kernel contains several binary-only modules that indicate
MODULE_LICENSE("GPL") in it - which is clearly not true. If you inquire about
the sources, they will respond that they will not provide the sources.
[ /linux/gpl-violations |
permanent link ]
Palm's failure with the App Catalog / Preware to the rescue
Especially since the 1.3.1 WebOS release, you can easily see the lack of
success of the official Palm App Catalog: Only about 60 Applications are
available to me from there. Why is that? Because the default setting in the
app catalog for any developer uploading the application is "US Only", i.e.
people who bought their Pre in other countries like Germany will not see the
majority of applications. That's really weird considering how much effort
Palm is spending in trying to convince people to write applications for
WebOS to increase the attractivity of their product. Now they artificially
reduce that for everyone outside the US.
So that's even one more reason to use the alternative package installer called
Preware which is available from webos-internals.org. This
alternative installer supports any number of feeds. It removes the
single-point of failure that an official Palm App catalog creates,
and replaces it with a proper community-driven approach. Anyone can
write and publish applications, anyone can distribute them to the users,
just like anyone is able to distribute/install MacOS, Windows or Linux
applications on the PC!
[ /linux/mobile/palm_webos |
permanent link ]
Re-discovering the marvels of Nokia DCT-3: Blacksphere, MADos & Co.
About 4-5 years ago I first discovered Project Blacksphere, a group of hackers
who were working on reverse engineering debug interfaces, as well as the actual
phone firmware and hardware of Nokia DCT-3 phones like the 3310. Unfortunately,
those projects have meanwhile been discontinued and seem to have died off.
When I last looked at that project, the status was still very limited with
regard to the actual GSM side of things. You could run MADos on your phone
and run some games inside it. Sure, being able to use the battery charger,
keypad, LCM, etc. from your own software on an undocumented device is already
great achievement, but if I want a small device without GSM then I just simply
use any random PDA or build something myself.
The point about reverse engineering an actual phone is exactly to get what
you cannot get from any other piece of hardware: Get access to the lower layers
of the GSM protocol stack. Since MADos still looked quite far away from that,
I didn't find it particularly interesting at that time.
Today I found a mirror
of the project blacksphere, and discovered that apparently they had come
much further with reverse engineering the interface between the DSP and the
CPU, which is the interface between layer 1 and layer 2 in the GSM stack. If
you fully understand that interface, you can write your own GSM stack on the
phone and have a true open source phone. The code and information available
is not quite at that stage at yet, but very close!
So since I have some 3310 phones (I constantly use them for OpenBSC testing)
and the FBUS and MBUS cables, I am definitely going to play a bit with MADos
and nlib in its latest known state. It might be the easiest way to write a
MS-side layer2 + layer 3 GSM protocol implementation and put it onto an
existing Layer 1.
[ /gsm |
permanent link ]
FOSS.in/2009 has started
I've arrived in India to attend FOSS.in/2009
in Bangalore. It's always great to be here and get in touch with Indian Free
Software developers.
Unfortunately I'm suffering from lack of sleep during the flight and jetlag, so
I had to miss large parts of the first day of the event :(
My keynote on Ooening up
Closed Domains went fine and was apparently fairly well received. The main
points being:
- There are many areas in computing, beyond the desktop PC, where there's still no freedom and openness due to a lack of Free and Open Source Software
- There's no real reason preventing developers to bring FOSS into those areas
- As can be seen by existing projects like OpenPCD, OpenBTS, OpenBSC: Very small teams of developers can make a big difference
[ /linux/conferences |
permanent link ]
OpenBSC: System Information + Rest Octet generation
During the flight to Bangalore I kept working on the system_information
branch of OpenBSC. This branch has been lingering in git for quite some time,
but I haven't yet felt confident enough to merge it into the official master.
In OpenBSC so far, the SYSTEM INFORMATION messages (type 1 through 6) are
not really generated by actual code. Rather, we use some templates that are
patched here and there with actual operational parameters such as the ARFCN
of the current cell. This has been easy for the very early start of the
project, but it has started to become more of a problem lately.
One example are neighbor cell lists. If you operate a network with multiple
cells, then of course you want to provide proper neighbor cell lists. At
HAR2009, we solved the problem by manually hard-coding the respective bitmasks.
That's of course not a proper solution.
Another problem is the notoriously complex encoding of the rest octets,
which culminates in the SI13 REST OCTETS describing the GPRS parameters
of a cell.
After a couple of hours in-flight hacking at the code in the sytem_information
branch, I am now confident that it provides superior quality SI messages and
rest octets than the hard-coded templates we used to have before.
Neighbor Cell lists and even SI13 rest octets are looking great when checking
them in the wireshark dissectors. I think it's ready for prime time now, and
the code should get merged into the master branch ASAP.
Now I am only left with one question: Should I consider this the first part of
the FOSS.in GSM workout? ;)
[ /gsm |
permanent link ]
Leaving for FOSS.in
I'm just about to go to the airport and leave for FOSS.in/2009. Most of my time there will again
be spent working
out on GSM protocol analysis, i.e. the airprobe project.
The workout wiki doesn't really have any content yet, and I shall fix that as
soon as I get the password for the Workout Wiki (apparently passwords from las
year don't work anymore).
It's going to be fun to meet all my Indian friends again - and at the same time
I'm happy that a large international community will be present, including
Stefan Schmidt, Holger Freyther and Andy Green of Openmoko fame, as well as people like
Milosch and Brita Meriac from projects like
OpenPCD, OpenBeacon and txtr, James Morris of netfilter/iptables and SELinux, Lennart Poettering of avahi and pulseaudio.
[ /linux/conferences |
permanent link ]
The Emperor's Codes: The Breaking of Japan's Secret Ciphers
During the last weeks, I've read the book The Emperor's Codes: The Breaking
of Japan's Secret Ciphers. As you can guess from the title, the book
relates to the various UK, American and Australian code breaker teams working
on breaking the encrypted communication of Japan during the second world war.
There have been plenty of books about the history of breaking Germany's Enigma
ciphering machine, but information on how the Japanese codes were broken so far
didn't seem to be as widespread - despite the resepective archives being opened
up during the last decades.
It has been a most interesting reading. As you can imagine, at that time almost
nobody had a sufficient understanding of the Japanese language, not even thinking
about how to encode Japanese writing into morse code.
Nonetheless, all of the Japanese merchant, diplomatic, army and navy codes have
been broken during the war. And surprisingly, the Japanese never really
assumed something is wrong with their actual encryption method. All they did
is to replace the codebook or the additive codebook.
Also, just like in today's GSM (A5/1) crypto attacks, even back then the
importance of known plaintext could not be underestimated. The verbosity
of Japanese soldiers addressing a superior officer and the stereotypical nature
of reports on weather or troop movements gave the cryptographers plenty of
known plaintext for many of their intercepted message.
What was also new to me is the fact that the British even back then demanded
that Cable+Wireless provides copies of all telegraphs through their network.
And that's some 70-80 years before data retention on communications networks
becomes a big topic ;)
Overall, definitely a very interesting book. I can recommend it to anyone with
an interest in security, secret services, WW2 history and/or cryptography.
[ /misc |
permanent link ]
Performance Enhancements in a Frequency Hopping GSM Network
Dieter Spaar had pointed out this book some months ago when I first raised some
questions regarding frequency hopping and the orthogonal nature of hopping
sequences with the same HSN but different MAIO.
Last week while David Burgess was with me, he also indicated that this book was
great and he unfortunately didn't think of bringing it along with him.
Meanwhile, I have immediately ordered the book and am already at something like
30% completion. It is a most interesting book to read, approaching GSM from an
advanced network planning angle, with a specific focus on the effects of
frequency hopping, uplink/downlink power control and DTX on the overall system
performance of a GSM network.
The theoretical foundations are always put in a GSM network simulator with
detailed channel model, but also actually implemented in a real-world GSM
network in Denmark.
Next to all the GSM specifications with their plethora of options and operator
dependent settings, this book gives a detailed (but still very technical)
background on how and why an Operator would configure his network to maximize
the service quality offered to his subscribers.
From the results, you can for example very clearly see that
- frequency hopping over a cyclic sequence gives higher gain improvement than random hopping,
especially if the number of channels in the mobile allocation is low
- frequency hopping gain is very dependent on the speed at which the MS
moves. At 3kph, the gain when hopping over 8 channels can be 7dB, while at
50kph the same hopping will only provide 1.5dB
- MAIO management (using different MAIO but same HSN) for all sectors in a
cell gives significant FER improvements
- handover algorithms differ quite a bit between non-frequency-hopping and frequency-hopping
networks
In the end, it seems, network planning is never about allocating your channels in a way they
don't overlap. That would limit the network capacity way too much. Network
planning seems to only be about averaging out the interference that cells inevitably have with
each other and ensure that the quality of the system only degrades with increasing load.
[ /gsm |
permanent link ]
Reverse engineering 16-in-1 Super SIM cards
In order to support some real cryptographic authentication in OpenBSC, we have to use SIM cards
with a known Ki (secret key). For cards that are issued by a real GSM operator, the Ki is only
stored in the SIM and in the Authentication center of the network. Since we cannot obtain it
from either of those two sources, we have to program our own SIM cards.
Unfortunately, SIM cards with privileges and/or documentation how to set Ki, IMSI and other
data are not readily available on the open market. There are a couple of other solutions, though:
- Use one of the old/cheap 6-in-1 / 16-in-1 SIM cards from the SIM cloning scene
- Implement the GSM 11.11 SIM card spec on a programmable card such as a PIC microcontroller card or Java Card
- Use something like the Bladox products to implement a SIM card or a SIM card proxy
The cheapest option with little R&D overhead is to use the so-called 16-in-1
SIM cards. They allow the user to set some of the interesting bits (Ki,
PMLNsel, ICCID, IMSI, SMSP): Sufficient for authentication, but not sufficient for
doing arbitrary tricks with the SIM.
Today I spent the better part of the day reverse engineering how both the SIM
card as well as the included SIM card reader work. The result can be found in the OpenBSC wiki.
As I've already implemented+tested general authentication and encryption
support in OpenBSC, all that is left to be done is some integration,
configuration and testing. With some luck we can soon operate OpenBSC with
full authentication and encryption support. This in turn will of course help with
cryptanalysis and other experiments in a controlled environment :)
[ /gsm |
permanent link ]
David Burgess (OpenBTS) visiting me for a couple of days in Berlin
On Friday, David Burgess of the OpenBTS project has come to visit me
in Berlin. We're working on the final preparation of the two-day Deepsec 2009 GSM Security Workshop which will
happen in Vienna next week.
David has more than 10 years experience in implementing GSM Layer 1 as well as
the higher-layer protocols, so it's always great to talk with him and tap into
his experience. Unfortunately the preparations for the workshop kept us too
busy to work on some actual code.
The more than 200 slides for the workshop will be published after the workshop
is over.
[ /gsm |
permanent link ]
India setting up service stations to program IMEI into phones
This is not really current news, as it was released much earlier this year.
However, I'm not following Indian news that closely so it has slipped my
attention:
India's COAI is setting up hundreds of service centers where end users can have an IMEI programmed into their phone.
This apparently relates to the fact that there are plenty of phones of Chinese
origin with an all-zero IMEI in India.
Since there is a government law that requires every phone to have an unique
IMEI number, operators have been ordered to refuse phones with an all-zero IMEI
onto their network.
I personally find all of this very funny:
- Firstly, what law enforcement typically cares about is the subscriber identity (the SIM). Persons are identified by their phone number. The phone number in turn is associated with the SIM. The SIM is issued by the operator and has a world-wide unique number called IMSI. So why would you care about the phone serial number? People can switch their phones much more easily than they can switch their SIM card, since the latter would always mean using a different number.
- Secondly, for most common phones (and particularly the cheaper Chinese phones), tools to program/reset the IMEI are readily available on the Internet. So what's the point for a government initiative to even create more such software, distributed widely across the country. Chances are high that software leaks.
- Finally, if I get a COAI-issued IMEI programmed into my phone, I can at any
time erase it again and go back to the COAI to have a new IMEI programmed into it.
So from a real IT security point of view, this entire exercise is nothing but
an annoyance to keep people busy and create employment for the staff operating
those IMEI programmers.
Tho those involved: Work smarter, not harder ;)
[ /gsm |
permanent link ]
German news site Spiegel Online has video of my torched car
Some 9 months after some
idiots have put my car on fire, the german news site Spiegel Online
reports on a
court trial unrelated to my car, but showing a video of my car.
Quite funny how they always dig out that footage. The court case was about
an alleged failed attempt to torch a car, so showing two completely burnt cars
in that article is not really sensible anyway.
As you can see from the article, there' already more than 250 burnt vehicles
this year in Berlin.
[ /personal |
permanent link ]
Android Mythbusters (Matt Porter)
Some weeks ago I was attending Embedded Linux Conference Europe. My personal highlight at this event
was the excellent Android Mythbusters presentation given by Matt Porter.
As you may know, Matt Porter was heavily involved in the MIPS and PPC ports of
Android, so he and his team have seen the lowest levels of Android, more and
deeper than even cellphone manufacturers ever have to look into it.
The slides of his presentation are now available for download. I would personally recommend this as mandatory reading material for everyone who has some interest in Android.
The presentation explains in detail why Android is not what most people refer
to when they say Linux. What most people mean when they say Linux is the
GNU/Linux system with it's standard userspace tools, not only the kernel.
The presentation shows how Google has simply thrown 5-10 years of
Linux userspace evolution into the trashcan and re-implemented it partially for
no reason. Things like hard-coded device lists/permissions in object code
rather than config files, the lack of support for hot-plugging devices (udev),
the lack of kernel headers. A libc that throws away System V IPC that every
unix/Linux software developer takes for granted. The lack of complete POSIX
threads. I could continue this list, but hey, you should read those slides.
now!
Just one more practical example: You cannot even plug a USB drive to an android
system, since /dev/sd* is not an expected device name in their hardcoded
hotplug management.
Executive summary: Android is a screwed, hard-coded, non-portable abomination.
I can't wait until somebody rips it apart and replaces the system layer with
a standard GNU/Linux distribution with Dalvik and some Android API simulation
layer on top. To me, that seems the only way to thoroughly fix the problem...
[ /linux/mobile |
permanent link ]
Enabling jabber in WebOS on the Palm Pre using a binary patch
One of my main complaints about the palm Pre is that there is no support
for the major IM protocol's such as jabber, icq, aim, msn, ...
As I discovered, they're actually using a library (libpurple) that supports
all those protocols. It's just the UI and the intermediate LibpurpleAdapter
program which artificially restrict the features that this library offers.
So it sounds to me like palm is getting money or other favors from Google
to artificially restrict the capabilities of the Webos messenger.
As I have described in this mail to the webos-internals mailing list, you can actually use a very simple one-byte binary patch to LibpurpleAdapter to enable jabber support.
After that binary patch, you can add jabber contacts with the regular
user@jabber-server.doma.in address and use the regular messenger application
for keeping in touch with your jabber contacts. Just like how it is supposed
to be.
Legal notice: Making this binary patch is legal, since LibpurpleAdapter is
actually released under LGPL. If you have a working build environment for the
Pre with all the libpurple headers, you can of course modify the source code
and recompile it (as explained in the mail).
Side note: The libpurple-adapter source code that Palm has published on
opensource.palm.com does not correspond to the actual binary code. This is a
LGPL violation. However, since palm is the copyright holder, nobody can really
do anything about it. But it once again shows that the software build/release
process does not automatically generate the source code packages and that there
is an erroneous manual process involved :(
[ /gsm |
permanent link ]
India prohibits import of GSM handsets without IMEI
As has been reported at telecomtiger.com, the Commerce Ministry of India has banned the import of mobile phones with no IMEI.
This is somewhat funny, as the IMEI is stored in flash memory in all the phones
that I have seen in recent years. Tools to erase or change the IMEI can be
found for many popular phones, including (but not limited) to the many MTK based
inexpensive phones from China.
So sure, you can now no longer import a device legally with no IMEI, but well,
any self-respecting organized criminal will find a way to erase or alter the
IMEI anyway ;)
[ /gsm |
permanent link ]
Implementing the GPRS protocol stack for OpenBSC
During the last week or so, I've been spending way too much time implementing
the network-side GPRS protocol stack as part of an effort to not only provide
GSM voice + SMS but also GPRS+EDGE data services with OpenBSC
GPRS is fundamentally very different from the classic circuit-switched domain
of voice calls and CSD (circuit switched data). Not only conceptually and on
the protocol level, but also in the actual system architecture. They way it
was added on top of the existing GSM spec is by making no modification to the
BSC and MSC, and only the minimal necessary modifications to the BTS. They
then added a new Gb interface to the BTS, and the SGSN and GGSN core network
components, who in turn talk to HLR/VLR/AUC.
So in the most primitive GPRS network, you can have the GSM and GRPS domains
completely independent, only using the same databases for subscriber records
and authentication keys. This goes to the extreme end that your phone would
actually independently register with the GSM network (ISMI ATTACH / LOCATION
UPDATING) and to the GPRS network (GPRS ATTACH / ROUTING AREA UPDATE). While
both of the requests get sent to the same BTS, the BTS will send the GSM part
to the BSC (and successively MSC), and the GPRS part to the SGSN.
Also, the actual software architecture looks completely different. In the GSM
circuit-switched domain you always have a dedicated channel when you talk to a
phone. The number of dedicated channels is limited by the transceiver capacity
and the channel configuration. In OpenBSC I chose to simply attach a lot of state
to the data structure representing such a dedicated channel. In the
packet-switched domain this obviously no longer works. Many phones can and
will use the same on-air timeslot and there is no fixed limit on how many
phones can share a radio resource.
What's further important to note: The protocol stack is very deep. If you look
at the GPRS related output on an ip.access nanoBTS while your mobile phone makes
a HTTP request, the stack is something like
HTTP-TCP-IP-PPP-SNDCP-LLC-BSSGP-NS-UDP-IP-Ethernet, while the first
HTTP-TCP-IP-PPP is obvious, I would not have expected that many layers on the
underlying network. Especailly if you look at the almost zero functionality
that NS (GSM TS 08.16) seems to add to this stack. Also, the headers within
the protocol can actually be quite big. If we only count the number of bytes
between the two IP layers in this stack: 8 bytes UDP, 4 bytes NS, 20 bytes
BSSGP, 6 bytes LLC and 4 byte SNDCP. That's a total of 42 extra bytes. And
that for every small packet like TCP SYN, SYN/ACK or the like! No wonder
that mobile data plans have been prohibitively expensive all those years ;)
So with regard to the actual GPRS implementation in OpenBSC, the following
things had (or still have) to be done
- Add support for generating System Information 3 + 4 rest octets and System Information 13
This is a very time-consuming bit-fucking experience, encoded relative to the padding pattern of 0x2b. Without this, the phones would not realize that the cell actually supports GPRS. DONE.
- Add support for the ip.access extensions to the A-bis OML (TS 12.21) layer
This is needed to configure the GPRS parameters such as channel configuration, coding schemes or the IP and NS/BSSGP parameters for the link to the SGSN (OpenBSC). Without it, the BTS would not even start to speak NS/BSSGP, i.e. not connect to OpenBSC for GPRS services. DONE.
- Implement the NS protocol (GSM TS 08.16)
Turns out this was really simple, as NS doesn't really do much anyway. DONE.
- Implement the BSSGP protocol (GSM TS 08.18)
This protocol is - among other things - responsible for the flow control. Both globally for the
BTS as well as individually for each MS. I've implemented the basic functionality to be able to
send/receive signalling and user data, but no flow control yet.
- Implement the LLC protocol (GSM TS 04.64)
This is actually the protocol that is terminated between the MS and the SGSN, so we have moved
beyond the BTS level here. Actual data from/to the mobile phone. I've implemented a minimal subset
of it, including the CRC24 checksumming. I'm not taking care of packet loss,
retransmissions or fragmentation yet. Just simple S, UI or U frames.
- Implement the GPRS mobility management (GSM TS 04.08)
This is pretty much work in progress, but GPRS ATTACH and ROUTING AREA
UPDATE is already handled. More work needed here, especially with regard to
persistent storage of P-TMSI allocations as well as the last-seen position of every MS
in a database.
- Implement the GPRS session management (GSM TS 04.08)
This is the messages for activating and de-activating PDP contexts. Work has not started yet.
- Implement GGSN functionality (PPP tunnel endpoints
After all, we need to terminate the PPP sessions that the phones establish somewhere. Work has not started yet
Once all that full stack has reached a level where it works to a minimal
extent, issues like BSSGP flow-control as well as LLC re-transmission,
fragmentation and [selective] acknowledgement have to be dealt with.
Finally, if somebody is bored enough, he could also work on things like combined
GSM/GPRS attach, or SMS over GPRS.
As you can see, it's quite a large task. But we need to start somewhere, and a
lot of this will still be needed when moving into the 3G and 3.5G domain. Even
if not at the lower level protocols, but from the software architecture point.
If you're into communications protocol development and don't mind our ascetic
'plain old C language' approach and are interested to contribute, feel free to
introduce yourself on the OpenBSC mailing list.
[ /gsm |
permanent link ]
A common misconception: GPRS encryption differs from GSM encryption
In the last couple of months, I've met numerous people with varying background
all sharing one misconception about cellular networks. Even I was not very
clear on this until recently: GPRS encryption is very different from GSM
encryption. Most people know it uses different algorithms, sure. But it also
operates on a completely different layer in the protocol, and is between two
different entities.
Encryption in GSM networks happens on the Layer 1 of the Um interface between
the MS and the BTS. It is a simple point-to-point encryption of only one
particular network interface. There is no more encryption as soon as the
signalling, voice and SMS data leaves the BTS (on a microwave link or actual
land line) to the BSC, MSC, SMSC and other network elements.
In GPRS, the encryption is not on the Layer 1, but on the Layer 2 (LLC) of the
Um interface. As the LLC layer is not terminated at the BTS but at the SGSN,
the data is still encrypted when it leaves the BTS.
This means, among other things, that things like eavesdropping on unencrypted
microwave links does not work for GPRS anymore.
[ /gsm |
permanent link ]
German constitutional court hearing on data retention
On December 15, there will be a court hearing by the German Constitutional Court
(Bundesverfassungsgericht) on the law on data retention which was enacted
in 2007 and has been valid since January 1st, 2008.
This law requires any communications network operator to keep digital records
of every voice call and e-mail, including sender and all recipient addresses.
This law was required by the European Union Directive 2006/24/EG, one of those paranoid
reactions against the perceived threat of terrorism. Laws implementing this directive in
the EU members Romania and Bulgaria have already been invalidated by their respective
constitutional court.
In Germany, more than 34,000 (I'm not kidding) people have filed a constitutional
complaints against this law. This is the first time that such a significant number
of individual citizens has ever made constitutional complaint. Only the
documents about power of attorney have filled 12 large boxes, each with many
folders. As you could probably guess by now, I'm one of those plaintiffs.
As an interim solution, the constitutional court has already decided on March 19, 2008 that such data
can only be used under special circumstances, such as only certain criminal offenses,
and only if there is already a very strong initial suspicion, and if there is close
to no other way to prove or deny the allegations brought forward by the prosecutor.
I hope the court hearing on December 15 will bring the court closer to actually
ruling on this case. This has been dragging on for a long time now.
Just like when the constitutional court had a hearing
on voting computers, I am planning to be in the audience and want to see
live what the constitutional court does with regard to matters that I strongly
care about. I hope my registration will make it in time... given the number of
plaintiffs I suppose there will be many more people interested in attending
the hearing than they have space. Which raises another interesting issue: I suppose
if you are an actual plaintiff, it would be weird if a court refuses you to be
at the actual hearing. But which court would hold > 34.000 plaintiffs? ;)
[ /politics |
permanent link ]
Qualcomm launches Open Source subsidiary
As several news sites have been reporting (here a report from LinuxDevices.com), Qualcomm has announced the launch of an Open Source Subsidiary.
As usual, I very much welcome such a move. Qualcomm is one of those companies
who have a very bad reputation in the Open Source and particularly Linux
community. They have so far failed to provide user manuals or other reference
documentation for any of their parts. They haven't even managed to publish
reference documentation on the external interfaces such as the AT command
dialect or the binary shared memory protocols that are used to interface the
GSM/CDMA/WCDMA baseband in their product.
So when it comes to an Open Source project that wants to interoperate with
Qualcomms hardware, they have so far been doing everything to make that as
hard as possible. Neither the community as large has access to the information
that it needs, nor do the Qualcomm customers get the respective document under
a license that allows them to actually contribute to Open Source projects.
If that documentation was available, or if Qualcomm was actually working on
FOSS licensed drivers and contributing those mainline, the support for
Qualcomm's hardware in Linux would be much better - resulting in less time to
market for companies interested in using Qualcomms parts in their products.
The actual press release does not indicate that this newly-founded subsidiary
truly understands this. It speaks of hardware-optimizing the performance of
mobile operating systems. That sounds like "we'll take the existing code,
make a fork, do non-portable micro-optimizations and ship that to our
customers". It does not mention actually contributing to the community
or understanding the benefit that the Open Source development model.
I remain to be convinced. Let's hope Qualcomm has scored somebody with a lot
of actual hands-on Open Source community experience to advise them properly.
[ /linux/mobile |
permanent link ]
Palm Pre: Nice UI, severe lack of functionality
Using the Palm Pre: Everything but an exciting experience :(
During the last week I've started to use my new Palm Pre (for those of you
who're living under a rock: The Palm Pre is a smartphone powered by an
Operating System called WebOS, which is in turn powered by the Linux kernel and
lots of other "standard" Linux programs like glibc, alsa, udev, ...
This adherence to a more standard Linux userland makes the Pre much more
attractive than the Android based products out there. Android is reinventing the
wheel everywhere, and things that Linux users and developers have been taking
for granted during the last five to ten years simply don't exist on Android.
To be honest, the experience was everything but exciting. More about that later.
Lets' start with the positive side of things. Yes, I like the device
for the following facts:
- it's using a not-too-ancient Linux kernel
- it uses a fairly standard Linux userland, that
- the development tools are also running on Linux (albeit proprietary)
- there is an easy way to access the command line of the device via USB
- there is software for re-flashing the phone in case it is bricked
- the WebOS "distribution" is built using OE and uses the ipk packet format
- they did not try to lock the device down from their users. You can easily
be root on your phone, install additional ipks from third parties and
own your phone
Which is what got me excited and made me buy one of those expensive devices.
However, looking at it from a strict user point of view, I am not very happy
with it. It simply lacks so much in functionality that it is not even funny.
- No RSS reader
The Nokia web tablets had a working, built-in RSS reader even many years ago
when the n770 was released. Given the importance of RSS feeds and blogs in todays web,
I'm surprised that webOS does not ship with a RSS reader. To make it even worse,
I could not find any third-party RSS reader for it!
- No Jabber / ICQ / AIM support
The messenger supports only SMS and Google Talk. WTF?!? What about the
millions of Jabber, ICQ, YIM, MSN and other users? Don't you think they want to use
their default messenger application with those accounts? This is particularly funny,
since they're using libpurple for the
actual messenger protocols, which is a LGPL'd library of the pidgin chat client. So the library has all those
capabilities, but Palm decided to arbitrarily remove them in their
LibpurpleAdapter program. Luckily that one is LGPL'd too, so removing the restriction
is relatively easy. But not for a regular user!
- Some applications always want to use the cellular network, even when wifi is available
This is particularly stupid when using their e-mail client. While I'm at
home or in some other area with wifi coverage, I don't want to squeeze every bit through
a high-latency cellular network. Why not simply make that decision a
per-application property that the user can set?
- Cheap mechanical quality
The mechanical quality is really disappointing for a device that sells for EUR 481. It's
much lower than what one is used to from Nokia, Blackberry or HTC devices in a
similar price range. As one example, the entire plastic of the device squeaks every time
I carefully push one of the keys on the keyboard.
- E-Mail client does not support pre-downloaded messages in subscribed IMAP folders
A standard feature that every desktop e-mail program has: Pre-download and cache the
message headers for fast listing / browsing through a mailbox. Not on the Palm Pre,
where the interactivity of the mail program is close to zero, fetching every bit over
a high-latency link. The entire point of using IMAP is to have local
copies/caches and to not suffer the latency/interactivity penalty of e.g. webmail!
- Calendar offers no integration with standard calendar formats/servers
There is no way how you can simply feed data from ical or xcal calender data into
the Palm Pre calendar. You can synchronize with Google and Exchange. WTF? Why do
we have [more or less] standard file formats for calendar data? Exactly for enabling
interoperability.
- No support for standards-compliant address books
You can import your contacts from Facebook, but you cannot import contacts from vcard
files, or let's say from a LDAP based address book. Great. So I first need to disclose
all the personal contact details from all my contacts, put those into Facebook
(into the US jurisdiction and a company that I don't trust) to simply get my contacts
on the phone ?!?
- Too low battery life
I can barely make it through one day even without making phone calls, simply having
the e-mail client running. The battery is too small. I would not mind a bigger/heavier
device in exchange for more power!
That is simply the user point of view. I also have many more technical points from a developer
perspective, but that is probably better kept for another post. Meanwhile I'm not sure
if the Pre was all that much of a good idea. The N900 is coming up next, and will be
much closer to the standard Linux userland stack (including X11, GTK, Qt, ...) than
the Palm Pre is.
[ /linux/mobile |
permanent link ]
Symbian kernel Open Source release and Tanenbaum
As most people have noticed by now, The Symbian Foundation has
released the source code of their microcernel under an open source license.
While any open source release of formerly proprietary software is something I
warmly welcome, I doubt that it will take of as an actual open source project.
There's a difference between releasing software under a FOSS license and running
a successful FOSS project. The latter involves a sufficiently large community
of developers, ways how they can contribute, ...
Especially with special purpose code such as an operating system (kernel) for
mobile devices, very few people will show interest as long as there is no
actual hardware where they can run the software, without or with custom
modifications. Sure, there will be academic interest and people who will
look at the source code to find ways to exploit potentially existing security
weaknesses, but no community of people who work on it since they will
practically use it on their own device.
So what I'd do if I was the Symbian Foundation: I would release an actual
mobile phone which is open enough for people to run (modified or unmodified)
recompiled parts of the Symbian codebase which are now available as open
source. This way it will be much more appealing. However, even at that point,
many other parts of the system are (or even will forever be?) closed, limiting
the amount of impact. Furthermore, since modified versions cannot be installed
on any other regular non-developer phones, the impact of any contribution to the
codebase can not be to the benefit of many people. Just compare that with
contributing to the mainline Linux kernel, where a contribution will be used on
at least almost every server/workstation/laptop after the next distribution
(and thus kernel) update.
Another issue that I really was shocked is the following quote by Andrew S. Tanenbaum: 'I would like to congratulate Symbian for not only making the source code of its kernel open source, but also the compiler and simulation environment,' said Andrew S. Tanenbaum'
However, the compiler was not made open source. It is released as
proprietary binary code, and is only "free as in beer" for organizations up to
20 employees. So either Tanenbaum did not really look at the hard facts of
what was being released, or he was misquoted in a really bad way! That should
not have made it into the final release, as it's now a damaging statement for
both the Symbian Foundation and Mr. Tanenbaum.
By the way, according to a lwn.net
comment thread, they're working on making it able to compile under gcc, and
they're actually accepting patches, which is of course great.
Despite my negative comments: I wish them as much luck and success as possible
with their new open source Symbian kernel. I personally just am not seeing it
turning into a vibrant, community-maintained project - and I hope the founders
of the Symbian Foundation did not start the project based on that assumption
and will in the end perceive it as a negative experience when evaluating the
open source move some years down the road.
One final note: The fact that they chose the EPL as license is really
strange, as it prevents exchange of code with the major existing FOSS kernel
projects (Linux, *BSD). Not that I think there is much to be exchanged, given
the microkernel approach...
[ /linux/mobile |
permanent link ]
FOSS.in CfP running for quite some time
In case you have been sleeping throughout last week: On October 16, The FOSS.in Call for Participation had been released.
FOSS.in is one of my regular conferences, and probably the only event aside
from the Chaos Communication Congress that I managed to visit in five
consecutive years. I'm looking forward for this year's incarnation, and I'll
definitely do my part to make the event more interesting :)
I hope everyone will now hurry to submit their proposals for talks, workshops
and work-outs! It's a collaborative event, and it lives by your contribution.
[ /linux/conferences |
permanent link ]
Differential Power Analysis on mobile phone?
cnet.com reports
some researchers succeeding in performing a differential power analysis (DPA) on
a mobile phone in order to "steal cryptographic keys that are used to encrypt
communications and authenticate users on mobile devices".
This sounds fishy. At least on GSM phones, the keys for authentication
are stored inside the SIM card. And somebody claiming that within a mobile
phone with it's many analog RF and digital circuits (causing interference and
noise) he can still perform a DPA on the SIM card just simply sounds
unreasonable.
I would like to see those results being fully disclosed and independently
reproduced before giving them much credibility.
The current encryption session key is not used for authentication, it is very
short lived (typically 1 to 5 calls before a new key is negotiated), and it is
not considered very safe anyway. The phone writes it to the SIM card, and
malware programs installed on the phone are likely to get access to that key
anyway. So no need for a DPA here...
[ /gsm |
permanent link ]
Letter to the European Commission opposing Oracle's acquisition of MySQL
As can be found here, Knowledge
Ecology International, the Open Rights Group and Richard Stallman have issued
a joint letter to the European Commission asking it to disapprove the
acquisition of MySQL by Oracle.
I very much welcome this move. There clearly is a conflict of interest between
Oracle's own proprietary database software offerings and MySQL. Sure, the
community could always fork MySQL, but at what cost? Potential disputes about
the trademark, being forced to rename itself, and confusion among the millions
of users world wide (well, might just be hundreds of thousands).
[ /linux |
permanent link ]
Palm Pre GSM model source code available
Last night I got an e-mail by palm, that following-up to my request, the source code releases for the WebOS 1.1.2 and 1.1.3 releases have been uploaded to opensource.palm.com.
I think the response time was very quick, and I thank them for that. However,
still sad that one has to remind them of it. Let's hope with future releases
they have a fully automatic process for that.
Just to be very clear: The GPL does not state that you have to automatically
have the source code on a web site. But the way how Palm's written offer is
phrased, they say that you should visit the website to download the sources.
In that case, the web site of course needs to contain the sources...
Additionally they also offer the source code on a storage medium, if you write
them snail mail to a specific address - which is a good safeguard since the GPL
says it has to be made available on a storage medium commonly used for software
interchange.
[ /linux/gpl-violations |
permanent link ]
TI tries to stop alternative operating systems on its calculators by the DMCA
Apparently, TI has been trying to use the DMCA and U.S. copyright to stop
third-party developers from working on or distributing alternative operating
systems for some of their calculators.
The stock OS that TI is shipping uses a cryptographic signature process to
prevent the user from booting any non-TI operating system. However, the
signature verification was broken and people have managed to run their
own software, developed independent from TI's software.
TI is not claiming that the DMCA DRM restrictions are applicable to this case,
and that the signature process constitutes a DRM system. This is obviously
bogus to any technical person. The TI firmware is not encrypted, and you can
copy and run it on other hardware or an emulator if you please. The protection
mechanism is rather the other way around: The hardware authenticates the OS.
The Electronic Frontier Foundation has taken
up the case and is defending some of the affected people from the community
against TI.
As you can see from the EFF letter to TI, the EFF cites a number of precedent cases where the courts have ruled in very similar cases that such mechanism is not a DRM system on the software.
That precedent summarized in the EFF letter is actually very exciting to me.
It is directly applicable to all kinds of locked-down devices. Let's assume
we're talking about a Linux-powered device like the Tivo, Motorola MAGX phones,
the G1 phone (non ADP-Version). They all use GPL Licensed software that is
cryptographically signed to prevent the user from exercising his Freedom to run
modified versions of the GPL licensed program.
Precedent that indicates that such a system does not constitute DRM as
protected by the DMCA means there is a lot more freedom for people to break
such systems and freely talk about how it was performed, as well as distribute
alternate software images for the respective devices - as long as the code they
use is either their own or Free Software and does not contain proprietary bits
of the device vendor.
[ /linux/gpl-violations |
permanent link ]
ST-Ericsson Community Workshop 2009
Today, I had the honor to hold the opening keynote of the ST Ericsson Community Workshop 2009.
At this event, ST-Ericsson presented their Nomadik STn8815 SoC, as well as
their work on getting the u-boot and kernel ports submitted back into the upstream/mainline projects.
As anyone following the linux-arm-kernel list will have noticed: For the last
months, they have worked hard on cleaning up and submitting the code for this
SoC. Like many people in the community, I personally appreciate this very
much. Finally, ARM SoC vendors actively putting resources to become a "first
class" member of the community.
The STn8815 is a ARM926EJ-S core based SoC, including a ST DSP for video codec
acceleration as well as a number of standard peripherals such as I2C, SPI,
UART, SDIO, etc.
The STn8815 reference software that they released today, includes 100% open
source drivers for everything that runs within Linux, inside Linux or on top of
Linux on the application processor. The codec implementations inside the DSP
are closed source / proprietary. However, the infrastructure to communicate
with the DSP, as well as the gstreamer/ffmpeg integration on the Linux side is
fully open source.
The attendees of the workshop are receiving the NHK-15 reference boards, which
have the STn8815 SoC plus a total of 384MByte NAND flash and 128MByte of DDR
memory. There's also a number of peripherals that you expect in such a
product, including LCM, SD card slot, Bluetooth, Audio Codec, and Wifi.
Unfortunately, the Wifi driver is closed source. However, the Wifi is a
dedicated peripheral component. The use/choice of this Wifi chip on the
NHK-15 is probably a bad design choice from an open source point of view. But:
This proprietary Wifi does not affect the openness of the actual STn8815 SoC.
Included with the kit for the attendees also a full programming manual as well
as register-level specification for the STn8815, as well as the complete
schematics of the development board. No NDA required :)
As a summary: I welcome ST-Ericsson to join the Linux community and to provide
Open Source friendly solutions, provide the documentation and holding this
workshop. However, the STn8815 is already quite 'old' hardware, as it is still
ARM9 based - while much of the competition is shipping ARM11 or Cortex-A8
today. Let's hope at some point in the future we will have more competitive
hardware with just as much openness.
[ /linux/conferences |
permanent link ]
The txtr e-book reader hardware architecture released
Today, the Berlin-baased start-up txtr has released more technical details on their first e-book reader.
They have also released their developer website including a wiki and access to a svn server with sources as well as fedora11 based source and binary RPM's.
What's also interesting is that they have disclosed a hardware block diagram and a PCB footprint on their developer website before the product even starts shipping to the mass market.
As few of you will know, some my friends and colleagues are behind the
system-level software and hardware R&D. The electrical engineering is done by
Milosch and Brita of bitmanufaktur, with
whom I've had the pleasure to work on OpenOCD, OpenPICC, OpenBeacon as well as
for a dedicated assignment inside Openmoko. Andy Green of Openmoko kernel +
bootloader hacking fame has also been involved... last but not least for
porting Qi (originally developed for the never manufactured Openmoko GTA03
based on the Samsung S3C6410) to the Freescale i.MX31.
[ /linux/mobile |
permanent link ]
Palm Pre privacy invasion
One great example of why we need more open source based mobile phones is that
we can actually discover all the undocumented "features" of the devices that we
use every day.
If I use a device for personal things like my private communication, my
scheduling, contact information and similar, then I have to put a certain
amount of trust into that device. I trust that the vendor selling this
device will provide a device that is safe for me to use and where my information
is stored securely.
However, the amount of closedness and control that equipment vendors and GSM
operators traditionally have in the mobile world is a big conflict with my
personal interest for privacy and security.
You can see this reflected by SIM Toolkit specifications that allow the operator
to read and modify your phonebook, or with flash over the air where the operator
is able to modify the software on your device.
In fact, in such cases the operators treat the device like they own the device,
when in fact the customer has bought the device and owns it.
Since Palm's WebOS is [to a large extend] based on Free / Open Source software,
we can analyze in more detail what they are doing. As it was pointed out
in this blog post two months ago, they seem to regularly receive
information when you were using which application, as well as the GPS coordinates of the phone!
This is outrageous, especially without any way for the user to switch it off -
or even better: Have an opt-in, i.e. off by default but who wants it can enable
it.
Palm has
responded to it, but as that very same posting indicates: The Palm Privacy
Policy is not even completely listing the information for which it is
applicable.
I don't think Palm is particularly worse than other companies. But the
question is: How do we know? How does the user know what his phone wants to
communicate to the operator or the manufacturer without his knowledge or
authorization? The only two ways I can imagine are:
- by having more open source software on the phone, so users can study the code, determine what it is doing and then modify the software to remove such privacy invading surveillance features
- by having more people with their own GSM/GPRS networks with projects like
OpenBSC, where we can actually see from the network side what the phone is
trying to do. Unfortunately GPRS support is still not finished in OpenBSC, but work is ongoing.
Since the Palm Pre units so far (CDMA and GSM) are not locked down, i.e. you
can become root and modify the software, it will be much easier to have "custom
ROMs" (where the name ROM is stupid since it is flash, ...)
I can only hope that people will quickly come up with custom Linux based
firmware images for the Palm excluding the surveillance features.
In addition, everyone should write a letter to Palm, complaining about those
features and the fact there is no way to opt out of them.
[ /linux/mobile |
permanent link ]
Palm Pre GSM Version sells in Germany - No corresponding source code
Some 4 months ago, I wrote about Palm shipping the Palm Pre CDMA version in a GPL incompliant
way. You should assume that the company has learned about their mistakes
and created opensource.palm.com as a
site to host their source code, compliant with the GPL and other Free Software
licenses
Yesterday, the Palm Pre GSM model started to ship in Germany through O2
Telefonica. The WebOS version installed on the device is 1.1.2, and they are
doing an OTA upgrade to 1.1.3.
Both of those versions are not available on the Palm opensource website!
Again the same mistake!
I wonder how much this tells us about the development procedures and release
management inside Palm. We know they use OpenEmbedded to build their packages
and filesystem image. OpenEmbedded can automatically generate the source code
tarballs (+ patches), so the entire process of putting them up at the website
could and should be automatized. No manual intervention, no mistakes, no
license violations.
I have asked my lawyers to send a letter to Palm, demanding immediate release
of the complete corresponding source code. If they do not comply, I am prepared
to take legal action against O2 who is distributing the devices in Germany. I
desperately hope we do not have to escalate to this point. If we go there, I'd
better not imagine how upset O2 will be about Palm and how this will affect their
business relationship.
It is so easy for Palm to have that source code on their website. We
know that for technical reasons (see above). Why are they deliberately exposing
themselves to the legal risk? Why are they willing to accept all the negative
PR from them not respecting copyright and the GPL?
Please don't get me wrong. I am not set out to continuously complain about
Palm. I would like to see more Linux phones. But why do they have to do
everything wrong they can do wrong? Why do they not have somebody to advise
them on playing nicely with the legal requirements of the technology they use?
[ /linux/gpl-violations |
permanent link ]
[ /gsm |
permanent link ]
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