Question: How to use EdDSA (Ed25519) in nRF Connect SDK?

[FARLY7]

Hi there,

We were using the Cryptographic library provided in the nRF5 SDK, with Oberon backend, to implement EdDSA/Ed25519 signing on our nRF5832 devices.

We are now in the process of migrating our application to nRF Connect SDK, however I am having a lot of trouble figuring out how I can get access to similar nrf_crypto_eddsa_sign() APIs to perform EdDSA signing.

There are lots of different combinations of crypto backends/frontends/libraries. It does not look like tinycrypt support Ed25519, and although the nrf_oberon library is included in NCS, I think frontend support for Ed25519 is missing in mbedtls.

There is an Ed25519 API shown in the nrf_oberon library in NCS documentation, however I cannot seem to use it in my application? Is this library meant for direct use by the developer? I have enabled NRF_OBERON in KConfig and the library is being correctly linked as shown in ncs/nrfxlib/crypto/CMakeLists.txt:24-25. However, when I attempt to #include "ocrypto_ed25519.h", the build system cannot find the header?

I just want to perform the same simple nrf_crypto_eddsa_sign() as used in the previous nRF5 SDK.

Any help or clarification is greatly appreciated!

[Marjeris Romero]

Hi Sean,

Sorry for the late reply.

I am having a lot of trouble figuring out how I can get access to similar nrf_crypto_eddsa_sign() APIs to perform EdDSA signing.

 You should be able to use the nrf_security API and then set nrf_oberon as a backend.

To enable nrf_oberon crypto library set the CONFIG_OBERON_BACKEND Kconfig variable to true.

See also the Ed2519 API: https://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrfxlib/crypto/doc/api.html#ed25519-apis

We provide some crypto test cases examples you can use as a starting point to setup your own test case: https://github.com/nrfconnect/sdk-nrf/tree/master/tests/crypto

Best regards

Marjeris