core: ltc: move sm2_kdf() to common core/crypto/sm2-kdf.c

The key derivation function sm2_kdf() is a helper function used by SM2
KEP (Key Exchange Protocol) and PKE (Private Key Encryption). It is
c

core: ltc: move sm2_kdf() to common core/crypto/sm2-kdf.c

The key derivation function sm2_kdf() is a helper function used by SM2
KEP (Key Exchange Protocol) and PKE (Private Key Encryption). It is
currently implemented in core/lib/libtomcrypt/sm2_kdf.c, next to the SM2
source code based on LibTomCrypt.

In order to provide an MBed TLS implementation of SM2, the helper
function shall be outside the LibTomCrypt directory. Move it to
core/crypto/sm2-kdf.c.

Signed-off-by: Jerome Forissier <jerome@forissier.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Acked-by: Etienne Carriere <etienne.carriere@linaro.org>

show more ...