builtin_curves

static VALUE ossl_s_builtin_curves(VALUE self)
{
    EC_builtin_curve *curves = NULL;
    int n;
    int crv_len = EC_get_builtin_curves(NULL, 0);
    VALUE ary, ret;

    curves = ALLOCA_N(EC_builtin_curve, crv_len);
    if (curves == NULL)
        return Qnil;
    if (!EC_get_builtin_curves(curves, crv_len))
        ossl_raise(rb_eRuntimeError, "EC_get_builtin_curves");

    ret = rb_ary_new2(crv_len);

    for (n = 0; n < crv_len; n++) {
        const char *sname = OBJ_nid2sn(curves[n].nid);
        const char *comment = curves[n].comment;

        ary = rb_ary_new2(2);
        rb_ary_push(ary, rb_str_new2(sname));
        rb_ary_push(ary, comment ? rb_str_new2(comment) : Qnil);
        rb_ary_push(ret, ary);
    }

    return ret;
}