CMAC_Init
if (!CMAC_Init(cmctx, p2, p1, NULL, NULL))
if (!CMAC_Init(cmctx, NULL, 0, p2, ctx->engine))
if (!CMAC_Init(cmctx, NULL, 0, NULL, NULL))
if (!CMAC_Init(cmctx, priv, len, cipher, e)) {
int CMAC_Init(CMAC_CTX *ctx, const void *key, size_t keylen,