unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
const unsigned char *d, size_t n, unsigned char *md,
unsigned int *md_len);
__owur int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx);
unsigned char *HMAC(const EVP_MD *evp_md, const void *key, int key_len,
const unsigned char *d, size_t n, unsigned char *md,
unsigned int *md_len);
__owur int HMAC_CTX_copy(HMAC_CTX *dctx, HMAC_CTX *sctx);