@LaF0rge@chaos.social avatar

LaF0rge

@LaF0rge@chaos.social

#Osmocom founder. Mobile Communication expert. Former Linux kernel hacker, freedom fighter. Nerd. #retronetworking. Mensch mit Kommandozeilenhintergrund. searchable via tootfinder. Director of https://mastodon.social/@sysmocom

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tnt, to random
@tnt@chaos.social avatar

Does anyone have resources / guides / examples on how to build OSHW zigbee end devices on linux ? Like without needing a windows VM to install some vendor dev environment ...

LaF0rge,
@LaF0rge@chaos.social avatar

@tnl I never looked into ZigBee, as it was always mentioned as this proprietary protocol stack without FOSS implementation on top of 802.15.4. What kind of stack are you planning to use? At least the 802.15.4 transceivers (like the one used in atusb) seem documented.

osmocom, to random
@osmocom@fosstodon.org avatar

Happy to announce the next on January 17m featuring a presentation on "Exploring eUICC and eSIM using pySim, lpac and osmo-smdpp" https://osmocom.org/news/243 by @LaF0rge - anyone interested, come and join us!

LaF0rge,
@LaF0rge@chaos.social avatar

@kxynos it should be recorded, though we sometimes had some BBB issues with lost recordings in recent history, so there's some risk

LaF0rge, to random
@LaF0rge@chaos.social avatar

anyone among my followers familiar with GlobalPlatform 2.3 "Annex A" certificates? Trying to wrap my head around how to reconcile them with X.509 and operate in a system that uses both those and X.509 certificates. #smartcards #followerpower

LaF0rge, to retrocomputing
@LaF0rge@chaos.social avatar

Documentary about the road from Palm PDAs to Handspring and its Visor + springboard slot leading to the experience of smartphones long before iPhone and Android. Makes me remember my Palm III, Palm V and visor times https://www.youtube.com/watch?v=b9_Vh9h3Ohw

LaF0rge, to random
@LaF0rge@chaos.social avatar

I finally got my proof-of-concept (and world wide first open source) SM-DP+ for consumer eSIM to work. This is the component from which the eUICC (chip in phone) downloads encrypted eSIM profiles. Code at https://gerrit.osmocom.org/c/pysim/+/35461 - will be merged to pysim master soon.

LaF0rge,
@LaF0rge@chaos.social avatar

The eSIM system uses X.509 certificates (with specific extensions), ECDSA, ECKA, a KDF, AES128 encryption, AES-CMAC. It was definitely the most crypto-heavy project I worked on in my career so far. AND THE GSMA SPECS CONTAIN NO TEST VECTORS FOR ANY OF THE CRYPTO!

LaF0rge,
@LaF0rge@chaos.social avatar

The eSIM protocols are designed in a weird way, almost like the authors didn't really know how to use ASN.1 properly. Normally you use ASN.1 so you can work on the abstract, decoded data provided by the generated code of your ASN.1 compiler. In eSIM you occasionally need to not use that and manually deal with DER TLVs as you have to verify signatures on partial sequences including the tag and length values

LaF0rge,
@LaF0rge@chaos.social avatar

@mxmehl there are specs, and I'd say they are comprehensive, though not always clear. Getting any kind of crypto working without test vectors is always making it unnecessarily difficult - especially if you use non standard encoding (e.g. ECDSA signatures not in PEM format)

LaF0rge,
@LaF0rge@chaos.social avatar

@nobletrout not sure what you are asking, sorry. The eSIM download protocols work over any IP network, doesn't need to be a cellular network, and hence no dependency on any specific "packet core"

foone, (edited ) to random
@foone@digipres.club avatar

The 37C3 talk on TEA1 encryption (used by police and military units in europe) is hilarious.
The hackers announced they found a vulnerability in the encryption, and one of the ways the organization that standardized TEA1 downplayed the breach was by saying that it wasn't viable, because it required "high powered GPUs".

So they ported their algorithm to a Toshiba Satellite running Windows 95, and re-cracked the encryption there.

https://media.ccc.de/v/37c3-11761-all_cops_are_broadcasting

(or https://www.youtube.com/watch?v=8KhbJ4pqcOY )

LaF0rge,
@LaF0rge@chaos.social avatar

@foone yeah, it is hilarious - but has already been presented several times in summer 2023, including at the ccc camp.

LaF0rge, to random
@LaF0rge@chaos.social avatar

RetroNetCall, our monthly #retronetworking video conference is just starting: https://osmocom.org/RetroNetCall https://osmocom.org/projects/retronetworking/wiki/RetroNetCall - all creatures welcome!

carolin, to random German
@carolin@pnpde.social avatar

Hey, Nerds. Ich brauche mal eure Hilfe. 🙌 Ich habe meine allererste SIM-Karte aus den 90s gefunden und mein Nokia 5110 funktioniert (wenig überraschend) auch noch. Ich würde sie gerne die SMS lesen, kenne meine PIN aber nicht mehr. Die zwei wahrscheinlichsten Optionen waren es schon mal nicht.

Gibt es die Möglichkeit, den Inhalt auf den Rechner zu bekommen, um probieren zu können? Wäre tatsächlich gewillt, einfach alle Kombinationen nach und nach zu testen. 😅

Gerne boosten. 🐘

LaF0rge,
@LaF0rge@chaos.social avatar

@carolin nein, das geht nicht. Ohne PIN1 bzw. PUK1 kommst Du nicht an die Daten ran. Der Sinn der chipkarte ist ja gerade, dass niemand sensible Informationen nicht auslesen kannst (Dein "auf den Rechner kopieren"), solange Du Dich nicht mit PIN ausgewiesen hast.

LaF0rge,
@LaF0rge@chaos.social avatar

@tor @carolin SMS wurden ursprünglich immer auf der SIM gespeichert. Zugang dazu nur mit PIN. Speicher auf dem Telefon kam später, v.a. wegen begrenztem Platz auf der SIM.

LaF0rge,
@LaF0rge@chaos.social avatar

@carolin eine SIM-Karte ist kein Speichermedium, sondern ein kleiner computer mit eingebautem storage und Software. Der Sinn ist gerade alles in einem Chip zu haben, incl. der Zugangskontrolle. Ohne diese Sicherheit vor dem Klonen würde das Geschäftsmodell der Netzbetreiber zusammenbrechen.

LaF0rge, to random
@LaF0rge@chaos.social avatar

sigh. Trying to implement ECDSA signature verification to match what happens between SM-DP+ and eUICC (in GSMA consumer eSIM) but I'm horribly stuck. [was so frustrated that I wenta and implemented SCP02 crypto meanwhile]. It works for the serverSignature1 initiateAuthenticationRes but fails for the smdpSigned2 in authenticateClientRes :(

LaF0rge,
@LaF0rge@chaos.social avatar

@jejb yes, thanks. I did get the r+s integer conversion to DER including the "additional zero byte in case of MSB of unsigned integer set" right, otherwise not even the first signature validation would pass. I don't get why the second one fails using the same code. And even in the second case the r+s are of same length in DER, I.e. no difference in MSB and hence zero extension.

LaF0rge, to random
@LaF0rge@chaos.social avatar

Am I the only one wondering why (at least high-end business) laptops still don't have SFP+ or QSFP28 slots these days?

LaF0rge,
@LaF0rge@chaos.social avatar

@purpleidea I never understand why people bother with a minimal increment like 2.5Gbps. I bought my first Gigabit Ethernet NIC in 22/23 years ago. Guess no other part of personal computing has failed to scale. Think of CPU/RAM/Storage etc. ini the same period.

LaF0rge,
@LaF0rge@chaos.social avatar

@purpleidea for USB the choice of Ethernet controller IC is more difficult. There are few > 1G and the USB3 bandwidth is limiting anyway. For a laptop built-in port, you attach the NIC chip to PCIe and there's no reason whatsoever to constrain yourself to gigabit.

stiefkind, to random German
@stiefkind@mastodon.social avatar

ePA = elektronische Patientenakte.
ePA = elektronischer Personalausweis.
#uxfromhell 🧐🤯

LaF0rge,
@LaF0rge@chaos.social avatar

@stiefkind Falsch. der nPA ist der elektronische Personalausweis! siehe auch https://de.wikipedia.org/wiki/Personalausweis_(Deutschland)#Der_elektronische_Personalausweis_(nPA)#Der_elektronische_Personalausweis_(nPA))

LaF0rge, to random
@LaF0rge@chaos.social avatar

Teardown of PictureTel SS740/SS760 ISDN video codec with pan/tilt camera for room conferencing systems: https://osmocom.org/projects/retronetworking/wiki/PictureTel_SS740_SS760 #retronetworking #isdn

mainboard of PictureTel SS740/SS760 with pan/tilt camera
PictureTel SS740/SS760 with top cover, camera and shield cover removed
pan/tilt mechanics + electronics of PictureTel SS740/SS760

LaF0rge, to random
@LaF0rge@chaos.social avatar

Teardown of Tandbeg TTC6-01 ISDN Video codec for conference rooms: https://osmocom.org/projects/retronetworking/wiki/Tandberg_TTC6-01 #retronetworking (6xBRI + 2xPRI is serious #isdn

picture of VGA + ISDN extension board of Tandberg TTC6-01 ISDN video codec
picture of connector / rear side of Tandberg TTC6-01 ISDN video codec

LaF0rge,
@LaF0rge@chaos.social avatar

@funkylab yes, for the room conferencing systems it was normal to bundle many B-channels. The most basic ISDN video phones already bundled 2 B channels of one BRI line. But imagine much highest resolution camera for a room, plus large screen... you really want more than 128kBit/s.

LaF0rge, to random
@LaF0rge@chaos.social avatar

Finally getting around to taking + publishing pictures of the DeTeWe ALIAN family of V5 Access Multiplexers I added to my collection quite a long time ago. See the child pages of https://osmocom.org/projects/retronetworking/wiki/DeTeWe_ALIAN/6 for details. #retronetworking

DeTeWe ALIAN MPU-H processor card of V5 access multiplexer
DeTeWe ALIAN E1B21 E1 line card of V5 Access Multiplexer

LaF0rge, to random
@LaF0rge@chaos.social avatar

Latest #retronetworking acquisition: One of the first commercially available #ISDN video telephones (this unit built in 1992, but I think the model is available 2-3 years longer). Apparently the "Telekom Bildtel 001" was built around a LOEWE MultiTel TV10 BTX terminal, plus an AEG/OLYMPIA codec unit and a TV camera.

Reat view of Bildtel 001 connectors (TV/BTX, codec unit)
Combined Keyboard and Receiver unit of Bildtel 001, inherited from LOEWE Multitel TV10 BTX terminal
Side view of internals of Bildtel 001 codec unit, showing power supply, 4 stacked mainboard and many add-in cards

LaF0rge,
@LaF0rge@chaos.social avatar

took some better pictures of the open Bildtel 001 (1992 ISDN video phone) Codec Unit: https://osmocom.org/projects/retronetworking/wiki/BildTel_001#Codec-unit #retronetworking #isdn

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