Re: [TLS] Extensions "supported_groups" and "key_share" in TLS 1.3

[Xuelei Fan <[e-mail]>]

>
> > > I think that specifying *both* in preference order, and recommending
> > > the servers to first inspect key shares and then supported_groups
> > > (if no intersect between what server supports and what key shares
> > > client provided) would end up with more predictable behaviour and
> > > cleaner code.
> > >
> > But if the orders are not consistent, the logic get annoyed.  It's a
> > good
> > practice to keep the order consistent, but it would be better if the
> > preference order is unique and specified in one place.
>
> that means that the code needs to keep references to two arrays at the
> same time and either create a hash table for lookups in key shares or
> iterate over key shares for every try - this makes code and logic more
> complex, not less
>
I did not get the idea, can the complex above be avoided if keeping both?
Does one preference order just get ignored?

If the orders are not consistent, if I can choose from two options:
continue or alter, I would choose the continue option.  Alert message is
expensive in practice.

Anyway, minor question, not a big concern to me.

Thanks & Regards,
Xuelei