DFU Signature error

RE: DFU Signature error

Vidar Berg — Mon, 01 Feb 2021 12:41:43 GMT

Hi RMV,

I think we can continue this in the other tread thread here: https://devzone.nordicsemi.com/f/nordic-q-a/71120/ecdsa-nrf52832-uecc-secure-bootloader. We generally recommend building the uECC library externally using the existing Makefiles.

RE: DFU Signature error

RVM — Sat, 30 Jan 2021 18:17:28 GMT

Hi Vidar

Thanks for the explanations so far.

I have a few quick follow up questions:

1. Are these extra defines for building the external uECC or do they also have to be included when building the bootloader.

2. We are developing with the nRF52832 which I believe contains the hardware FP unit.
Can/Should I use FLOAT_ABI_HARD or is the use of the FLOAT_ABI_SOFT mandatory for the uECC build?

3. What role does this definition "uECC_SUPPORT_COMPRESSED_POINT=0" play in the build?
Is it mandatory? If so, and it is not defined, will the validation fail?

Cheers

RMV

RE: DFU Signature error

navman — Mon, 05 Oct 2020 10:52:19 GMT

Resolved using IAR Toolchain:

I got it working also using the IAR Toolchain. I missed some of the defines, when I ported it from gcc make file. So I put in these defines in the IAR project:

FLOAT_ABI_SOFT
uECC_ENABLE_VLI_API=0
uECC_OPTIMIZATION_LEVEL=3
uECC_SQUARE_FUNC=0
uECC_SUPPORT_COMPRESSED_POINT=0
uECC_VLI_NATIVE_LITTLE_ENDIAN=1

and it works as expected.

Thanks for your support Vidar Berg.

RE: DFU Signature error

Vidar Berg — Mon, 05 Oct 2020 08:56:37 GMT

Thanks for the update! We have not tested or verified uECC with the IAR toolchain. But did you remember to build with uECC_VLI_NATIVE_LITTLE_ENDIAN=1? The bootloader expects it to be little endian.

RE: DFU Signature error

navman — Fri, 02 Oct 2020 16:16:21 GMT

Resolved:

I rebuild the micro ecc library using the gcc compiler instead of IAR, but needed to add -gdwarf-3 compile flag in the makefile in order to debug the application with c-spy in IAR ARM Workbench. Now it works :-). I will investigate what is missing in my micro ECC library project in IAR and update this thread in case other needs this information.

RE: DFU Signature error

navman — Fri, 02 Oct 2020 12:42:40 GMT

Hello

Yes I have rebuild the secure_bootload after replaced the public key with my own generated one.

I have just tested the example uisng the precompiled hex file and that works also with the other secure_dfu_test_images avaialble in the SDK, so something is seems to be wrong with my secure_bootloader when building it uisng IAR Workbench.

Can it be related to the micro-ecc library which I have to rebuild in IAR ARM workbench to make it work (IAR compalins about som debug.info when build the libarry using the build_all.bat)?

RE: DFU Signature error

Vidar Berg — Fri, 02 Oct 2020 12:09:19 GMT

Hello,

It sounds like you have done everything correctly, so not sure why it's failing. Just to make sure, earlier when you used your own key-pair, did you remember to re-build the bootloader with the new public key?

Also, I tested DFU with the pre-compiled bootloader from SDK 15.0.0 just now, but did not get a signature verification error. Here's how I tested it:

1. Program bootloader hex in "C:\vidar\workspace\nRF5_SDK_15.0.0_a53641a\examples\dfu\secure_bootloader\pca10040_ble_debug\hex\ with nrfjprog: nrfjprog --program devzone.nordicsemi.com/.../4426.secure_5F00_bootloader_5F00_ble_5F00_s132_5F00_pca10040_5F00_debug.hex --chiperase -r

2. Performed dfu with the " devzone.nordicsemi.com/.../6153.ble_5F00_app_5F00_buttonless_5F00_dfu_5F00_without_5F00_bonds_5F00_s132.zip" package in \examples\dfu\secure_dfu_test_images\ble\nrf52832

RE: DFU Signature error

navman — Fri, 02 Oct 2020 10:43:45 GMT

Update:

I have tested the example "secure_bootloader_ble_s132_pca10040_debug - nrf52832_xxaa_s132 from the SDK15, with same results. I think I am missing something basic here, since I assume the examples works "out of the box". Here is the log from the SDK 15 example when performing a DFU with file "bootloader_secure_ble_debug_without_bonds_s132.zip".

devzone.nordicsemi.com/.../0245.log.txt