Debug NRF_ERROR_CRYPTO_INTERNAL

[yes]

Hi,

Our device is based on nRF52840  SDK 15.0.0

The device verifies signature of incoming messages (which were sent over BLE from PC application) using ECDSA with spec256r1 curve.

Verification code is based on ECDSA example (Bob's verify function)

We got error code NRF_ERROR_CRYPTO_INTERNAL (34070) from executing backend implementation (line 459 in nrf_crypto_ecdsa.c file)

     result = backend_implementation(p_context, p_public_key, p_hash, hash_size, p_signature);

How can we debug this internal error?

Any ideas what can be the root cause for this issue?

Thanks in advance 

[Edvin]

Hello,

Can you please try to use a different backend (uecc or oberon), to see if the problem persists. If it does, then the issue is located in the user data. At least it is possible to debug in this case. The cc310 is a closed source library, so it is a bit harder to debug.

If it doesn't fail when you use e.g. uecc, we have to try to reproduce the issue here, and see if some of our crypto engineers can figure out what's wrong.

[yes]

Can wrong input (e.g. endianness of key) be the root cause for this type of failure i.e. NRF_ERROR_CRYPTO_INTERNAL?

[Edvin]

That is at least something that I would check out. I assume it can.