Derive key for ECDH

FMaro.1 · ‎2024-07-29

Hi everyone,

I develop a asimmetric public/private key crypto scheme and then with simmetric derived ley establish a comms with HOST REMOTE <-> [LOCAL HOST/STSAFE].

I generate with ephimeral slot with:

ret_code = (int32_t)StSafeA_GenerateKeyPair(handle, STSAFEA_KEY_SLOT_EPHEMERAL, 0xFFFF, 1,
                                            (STSAFEA_PRVKEY_MODOPER_AUTHFLAG_CMD_RESP_SIGNEN |
                                             STSAFEA_PRVKEY_MODOPER_AUTHFLAG_MSG_DGST_SIGNEN |
                                             STSAFEA_PRVKEY_MODOPER_AUTHFLAG_KEY_ESTABLISHEN),
                                            STSAFEA_NIST_P_256, STSAFEA_XYRS_ECDSA_SHA256_LENGTH,
                                            &pointreprensentationid, &pub_cx, &pub_cy,
                                            STSAFEA_MAC_NONE);

And then generate a PEM wich will be sended to REMOT HOST, in the next step receive PEM from the other extreme and extract XY ECDAS pair.

How should i do if i want to set up a derived key and share it with the REMOTE HOST?. I cant find de Derive Key command in MW of STM CUBE MX pack, only find de EstablishKey command for SPL02 profile.