DH_get0_pub_key
const BIGNUM *DH_get0_pub_key(const DH *dh);
if ((dh_y_len = BN_num_bytes(DH_get0_pub_key(dh))) <= 0)
if (BN_bn2bin(DH_get0_pub_key(dh), data) != dh_y_len)
if (!DH_check_pub_key(dh, DH_get0_pub_key(dh), &check_flags))
if ((key_len = DH_compute_key(key, DH_get0_pub_key(dh_peer), dh)) <= 0)