GM 5 byte seed/key tool

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GM 5 byte seed/key tool

Postby kur4o » Wed Mar 01, 2023 7:19 pm

Found a link with 5 byte seed/key generator. Seed needs to be valid and conforms to some unknown special rules, so you can`t just use random seed for testing.

https://universalpatcher.net/gm-5-byte-keys/

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Re: GM 5 byte seed/key tool

Postby ironduke » Thu Mar 02, 2023 12:39 am

Just a quick review for anyone wondering, it works quite well for E92,E82,E78 and E39a...

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Re: GM 5 byte seed/key tool

Postby In-Tech » Thu Mar 02, 2023 2:56 am

Wow, I missed this somehow. I will try it out. Thanks kur4o and ironduke :)

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Re: GM 5 byte seed/key tool

Postby Gatecrasher » Thu Mar 02, 2023 5:59 am

The only rule I've been able to guess at so far is that SPS seeds need to end with either 01 or 06, and DVT seeds need to end with 0C.

I think I also read that if you feed it a seed of 11 11 11 11 11, you should get 55 55 55 55 55 for the key. Or maybe I've got that reverse. But it's supposed to be used for testing your code implementation.

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Re: GM 5 byte seed/key tool

Postby gmtech825 » Fri Mar 03, 2023 12:19 am

has anyone figured out the DVT algo?

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Re: GM 5 byte seed/key tool

Postby Gatecrasher » Fri Mar 03, 2023 6:23 am

I suspect it's the same theory, but a different set of crypto values. This is a half wild guess, but I think the constant references to SA015BCR are "Security Access 01 5 Byte calc (crypto?) routine".

So there's probably a similar SA035BCR within GM for DVT functions.

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