Enable MBEDTLS debugging Nordic provided security backend (for CoAP Secure via OpenThread on nRF5340)

RE: Enable MBEDTLS debugging Nordic provided security backend (for CoAP Secure via OpenThread on nRF5340)

Jørgen Holmefjord — Fri, 29 Apr 2022 10:31:21 GMT

Hi,

It looks like MBEDTLS_BUILTIN is disabled by MBEDTLS_LIBRARY_NRF_SECURITY when building for nRF5340. I see this warning in the build log when building your project with the suggested build command (I also enabled the symbol in the overlay):

warning: The choice symbol MBEDTLS_BUILTIN (defined at
C:/ncs/v1.9.1/zephyr/modules/mbedtls/Kconfig:27, C:/ncs/v1.9.1/zephyr/modules/mbedtls/Kconfig:27,
modules\mbedtls\Kconfig:27) was selected (set =y), but MBEDTLS_LIBRARY_NRF_SECURITY (defined at
C:/ncs/v1.9.1/nrf/Kconfig.nrf:19) ended up as the choice selection. See
http://docs.zephyrproject.org/latest/reference/kconfig/CONFIG_MBEDTLS_BUILTIN.html and/or look up
MBEDTLS_BUILTIN in the menuconfig/guiconfig interface. The Application Development Primer, Setting
Configuration Values, and Kconfig - Tips and Best Practices sections of the manual might be helpful
too.

This default security library option is selected by the OpenThread Kconfig in nRF Connect SDK, and is set to OPENTHREAD_NRF_SECURITY_CHOICE. If you want to use the Zephyr built-in MBEDTLS library, you can try to set "CONFIG_OPENTHREAD_MBEDTLS_CHOICE=y".

Best regards,
Jørgen

RE: Enable MBEDTLS debugging Nordic provided security backend (for CoAP Secure via OpenThread on nRF5340)

Janfried — Mon, 11 Apr 2022 20:44:29 GMT

Hi Jørgen

Thank you for your answer! Of course. I pushed the code to a public repo:

https://gitlab.com/dev2409/nRF5430

best regards

Jan

RE: Enable MBEDTLS debugging Nordic provided security backend (for CoAP Secure via OpenThread on nRF5340)

Jørgen Holmefjord — Mon, 11 Apr 2022 12:18:49 GMT

Hi Jan,

I tried to reproduce the issue on my end, but I was not able to do so. I added the configs and changes you described above, but I may have missed something.

Can you upload the project, or a patch with the required changes to reproduce the issue?

Best regards,
Jørgen

RE: Enable MBEDTLS debugging Nordic provided security backend (for CoAP Secure via OpenThread on nRF5340)

Janfried — Tue, 05 Apr 2022 04:41:47 GMT

Hi Jørgen

Thank you very much for your answer!

I tried to delete the build folder according to the post and built the project again and also in a new workspace. Unfortunately, with the same result as before.

My CMakeLists.txt is the same as the one in the echo_client sample.

Best regards

Jan

RE: Enable MBEDTLS debugging Nordic provided security backend (for CoAP Secure via OpenThread on nRF5340)

Jørgen Holmefjord — Mon, 04 Apr 2022 15:09:17 GMT

Hi,

Can you try to delete the build directory before building, as suggested in this post?

Best regards,
Jørgen