Sets the curve parameters. generator must be an
instance of EC::Point that is on the curve. order and cofactor are integers.
See the OpenSSL documentation for
EC_GROUP_set_generator()
static VALUE ossl_ec_group_set_generator(VALUE self, VALUE generator, VALUE order, VALUE cofactor)
{
EC_GROUP *group = NULL;
const EC_POINT *point;
const BIGNUM *o, *co;
GetECGroup(self, group);
GetECPoint(generator, point);
o = GetBNPtr(order);
co = GetBNPtr(cofactor);
if (EC_GROUP_set_generator(group, point, o, co) != 1)
ossl_raise(eEC_GROUP, "EC_GROUP_set_generator");
return self;
}