EVP_DigestInit
if (!EVP_DigestInit(md_ctx, md))
if (!EVP_DigestInit(&md_ctx, md))
#define EVP_SignInit(a,b) EVP_DigestInit(a,b)
#define EVP_VerifyInit(a,b) EVP_DigestInit(a,b)
int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type);
if (!EVP_DigestInit(ukm_hash, EVP_get_digestbynid(nid)))