dsa_verify
ret = dsa_verify(&pub, msg, sizeof(msg)-1, sig, sizeof(sig), HASH_SHA256);
ATTRIBUTE_WARN_UNUSED_RET int dsa_verify(const dsa_pub_key *pub, const u8 *msg, u32 msglen,
(void (*)(void))dsa_verify }, \
static OSSL_FUNC_signature_verify_fn dsa_verify;
{ OSSL_FUNC_SIGNATURE_VERIFY, (void (*)(void))dsa_verify },