Re: Hacking the Nintendo Alarmo

The Running Man <running_man@writeable.com> wrote:

<https://garyodernichts.blogspot.com/2024/10/looking-into-nintendo-alarmo.html>
 
I was somewhat surprised how easily they decrypted the encrypted
firmware.
 
"The CRYP interface is configured for AES-128-CTR, which makes things
easier.  Since, in CTR mode, a keystream is created, which is then
combined with the plaintext to encrypt and decrypt files, we can
simply create a large amount of this keystream using the CRYP
interface, and then combine it with the encrypted files to decrypt
them"
 
This shouldn't be possible since they keystream should never be
reused.

Yes, but this is also why the usual comment re. broken crypto goes
something like:

  "The cryptographic primitives are secure, it is the
   use/implementation of those into a larger system that is broken".

AES-128 is secure.

AES-128-CTR is also secure, **if used correctly**.

This is yet one more in a long line of examples of "not used correctly".