EC_GROUP_set_generator
if (!EC_GROUP_set_generator(ret, point, a, b)) {
if (!EC_GROUP_set_generator(group, P, order, x)) {
int EC_GROUP_set_generator(EC_GROUP *group, const EC_POINT *generator, const BIGNUM *order, const BIGNUM *cofactor);
if (!EC_GROUP_set_generator(group, point, order, NULL))