Multiple ways to handle DTLS keys?

[Bjorn191023]

Hi,

1) The LwM2M sample app uses the function nrf_inbuilt_key_write() in nrf_inbuilt_key.h to store keys for DTLS

2) The Zephyr LwM2M implementation uses function tls_credential_add() in net/tls_credentials.h to store keys for DTLS (see function load_tls_credential() in lwm2m_engine.c). This  way of handling keys is disabled/overrided in the lwm2m sample app.

I tried to use method #2 in the LwM2M sample app but did not get it to work.

Please clarify how the two different key management methods are related to eachother! Does only method #1 work with nRF9160?

BR / Björn

[Didrik Rokhaug]

Hi.

The Zephyr API (tls_credentials) was based on the nRF API, but there is no relation between the implementations.

On the nRF91, the credentials are stored inside the modem, so only the nRF API will work.

There is a pull request open that will rework the nRF key management API. It will become modem_key__mgmt_* and will be open-sourced to some extent:

https://github.com/NordicPlayground/fw-nrfconnect-nrf/pull/1463

Note that using the new library will be equivalent to using AT commands to manage the credentials.

Best regards,

Didrik