curve_name

static VALUE ossl_ec_group_get_curve_name(VALUE self)
{
    EC_GROUP *group = NULL;
    int nid;

    GetECGroup(self, group);
    if (group == NULL)
        return Qnil;

    nid = EC_GROUP_get_curve_name(group);

/* BUG: an nid or asn1 object should be returned, maybe. */
    return rb_str_new2(OBJ_nid2sn(nid));
}