group

static VALUE ossl_ec_key_get_group(VALUE self)
{
    VALUE group_v;
    EC_KEY *ec;
    ossl_ec_group *ec_group;
    EC_GROUP *group;

    Require_EC_KEY(self, ec);

    group_v = rb_iv_get(self, "@group");
    if (!NIL_P(group_v))
        return group_v;

    if ((group = (EC_GROUP *)EC_KEY_get0_group(ec)) != NULL) {
        group_v = rb_obj_alloc(cEC_GROUP);
        SafeGet_ec_group(group_v, ec_group);
        ec_group->group = group;
        ec_group->dont_free = 1;
        rb_iv_set(group_v, "@key", self);
        rb_iv_set(self, "@group", group_v);
        return group_v;
    }

    return Qnil;
}