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UID:pretalx-hack-lu-2025-3UEDY8@pretalx.com
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DESCRIPTION:# Digic8 Oracle\n### Decrypting camera updates without knowing 
 neither the key\, nor algorithms (at first)\n\nSince years\, Canon cameras
  firmware has been enhanced by hackers\, via the [CHDK] project for Powers
 hot models and [MagicLantern] for DSLR/mirrorless ones\, applied to DIY dr
 one photography for example [DRONES].\nStarting 2010\, the Magic Lantern t
 eam is able to execute code by enabling an hidden Canon payload loaded fro
 m the SD card : autoexec.bin. Enabling this feature requires forging valid
  signatures for camera updates\, and required the team to fully understand
  cryptography of these .FIR files. But since the EOS R camera launch in 20
 18\, FIR cryptography changed and no one publicly explored this new FIR ve
 rsion. \n\nWe will introduce the technical context as well as FIR file for
 mat version 4 (before 2018)\, then\, we will use :\n1 - the fact some rece
 nt Canon cameras (R\, RP\, R6) allow dumping their firmware via an embedde
 d basic interpreter and \n2 - Unicorn emulation to decrypt easily camera u
 pdate files of the same hardware (Digic) generation\, because a unique key
  is used.\n\nAs a first step\, emulation will allows access to FIR content
  (camera firmware updated code)\, without the need to understand neither t
 he underlying cryptographic algorithms\, nor keys : dumped code will be us
 ed "as oracle" by emulation. Then we will describe how is working decrypti
 on key generation for Digic 8\, and finally the scheme of asymnetric signa
 tures and how to verify them for both Digic 8 and Digic 10 cameras.\n\nTwo
  python tools will be released: **d8_oracle.py** to decrypt Digic 8 update
 s via emulation of dumped firmware\, and **d810_verif.py** to verify FIR d
 igital signatures\, based on secp256r1 curve.\nd8_oracle.py requires you f
 irst to dump yourself a firmware via CBasic or to obtain such camera dump 
 via Magic Lantern community for example.\n\nNo decryption key neither firm
 ware dump will be released with this talk. \n\nLaurent Clévy already reve
 rsed Canon picture authentication scheme (Original Data Decision in Canon 
 terms) years ago\, as well as a python tool to recompute signatures [ODD].
  He also rediscovered FIR cryptography before 2018 and described it at Bee
 Rump 2022 [BeeRump]. \n\nEOS\, Digic and Powershot are Canon trademarks.\n
 \nReferences:\n* [CHDK](https://chdk.fandom.com/wiki/CHDK)\n* [MagicLanter
 n](https://www.magiclantern.fm/)\n* [DRONES](https://ardupilot.org/plane/d
 ocs/common-chdk-camera-control-tutorial.html)\n* [ODD](https://connect.ed-
 diamond.com/MISC/mischs-006/mecanisme-de-controle-d-authenticite-des-photo
 graphies-numeriques-dans-les-reflexes-canon)\n* [BeeRump](https://www.rump
 .beer/2022/slides/camera_jailbreak_v2_green.pdf)
DTSTAMP:20260607T234820Z
LOCATION:Europe
SUMMARY:Digic8 Oracle - laurent clevy
URL:https://pretalx.com/hack-lu-2025/talk/3UEDY8/
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