ECDSA + nRF52832 + uECC + secure bootloader?

RE: ECDSA + nRF52832 + uECC + secure bootloader?

RVM — Wed, 03 Feb 2021 17:18:39 GMT

THank you. I will try to get back to this in a couple of weeks and let you know -- want to deliver something with whatever works now i.e. Oberon backend.

Cheers

RMV

RE: ECDSA + nRF52832 + uECC + secure bootloader?

Vidar Berg — Wed, 03 Feb 2021 09:56:48 GMT

The library should have been built correctly as long as you used the Makefile. Maybe you could try the one I have compiled below and see if it gives the same result.

uECC nrf52hf_armgcc lib

devzone.nordicsemi.com/.../micro_5F00_ecc_5F00_lib_5F00_nrf52.a

RE: ECDSA + nRF52832 + uECC + secure bootloader?

RVM — Mon, 01 Feb 2021 16:40:12 GMT

I am building with Eclipse and GCC so I only built the GCC version of micro-ecc under "external\micro-ecc\nrf52hf_armgcc\armgcc'

RE: ECDSA + nRF52832 + uECC + secure bootloader?

RVM — Mon, 01 Feb 2021 15:34:28 GMT

Hi Vidar

I was able to get ECDSA to work with Oberon. The nrf_sw_backend version kept giving me a signature failure with error number 0x8542 (?).
I could not figure out why (digging further, all I could figure out was that the 'expected' and the 'observered' signatures did not match) so I decided to switch to Oberon and see if that worked, which it did.
I understand that the uECC version has a smaller memory footprint and I would really love to get that working but for now I have at least one variant working and that gives me a baseline for future experimentation.

Thanks for your support here, and elsewhere, with this issue.

Cheers
RMV

RE: ECDSA + nRF52832 + uECC + secure bootloader?

Vidar Berg — Mon, 01 Feb 2021 12:37:24 GMT

Hi,

Did you manage to build the uECC libraries with the 'build_all.bat' helper script in \nRF5_SDK_16.0.0_98a08e2\external\micro-ecc? The bootloader project is by default configured to use the uECC library for ECDSA and the nrf_sw_backend_hash.c (--> sha256.c) implementation for hashing.

The "ECDSA_P256_SHA256" boot validation mode should also be supported out of the box.