CC310 library ECC public_key_calculate is absent

[jacksong]

Hi, all

I'm going to develop a crypto application, and tested on nRF52840 with nRF5_SDK_17.0 CC310 run-time library. 

there are a need is compute public key from a known ECC private key, and can't implement  through current SDK library.

you can see #define nrf_crypto_backend_secp256r1_public_key_calculate NULL defined in SDK_Root\components\libraries\crypto\backend\cc310\cc310_backend_ecc.h

that hint public_key_calculate is not support!

so, I want to verify that this library really does not support this feature？if not yet, is it possible to use CC310 API directly to compute public key or ECC-Key-pair? 

PS: I see oberon library implemented the compute public key API, but it consume more CPU process time than CC310 that  apply hardware accelerate, therefor, CC310 is the only choice

[Einar Thorsrud]

Hi,

The CC310 runtime library does not have any API for computing a public key from a private key, so this is unfortunately not possible. You will need to do this in software.