gen5w standard (Ev6) update_info

[dibble9012]

I am attempting to patch firmware from the Korean EV6 to the NAM EV6 (to have wireless CarPlay in their latest update). I have been able to decrypt the tar list and edit, then encrypt again. But I believe inside system_package there is an update_info file that is causing issues. The moment I change the system images the headunit will not install. I have been updating the 2022_EV6_USA.ver file with the updated CRC and file size and still will not install, as well as updating the version.info file. Do I need to resign this version.info file after editing? And will the private key included in this utility pass the headunit checks? Any ideas?

[Helloyunho]

Sorry for the late reply, I missed this one 😅

First of all, the Korean firmware doesn't support the wireless phone projection yet(my dad's car is Korean version so I tested it but nada...)
Though I think they're gonna support it soon

Anyway, about the file update_info... Hyundai is using RSA signing to check the firmware's integrity
The way it works is like this:

1. Encrypt the file you want to make a checksum with private key(yes, I didn't even know this was possible lol)
2. When it comes to check the integrity, decrypt the checksum file with public key(again, it's possible)
3. If the file is the same, you know that it's valid!

Rather interesting, but surely not a bad way to achieve it
The sad point(and I'm sure Hyundai used this method because of this) is that you don't need to reveal the private key to check the integrity, and that's exactly what Hyundai did: only including the RSA public key to the firmware
And since we only have the public key and not the private key, we essentially cannot make our checksum file

Conclusion

• Wireless phone projection doesn't work even on the Korean models
• update_info is checksum-ed with RSA signing
  • You need a private key to sign a file
    • But since we only have the public key, we can't make the checksum file by ourselves
  • I'm trying to overcome this problem by making my own RSA private/public keys and force updating the firmware with my own keys included
    (making my own keys works and tested, but I still need a way to force update the firmware)

[7ikw]

Have any one figure out how to change the Korean sitting to middle east with the new update!?