[noise] Draft extension: Authentication of handshake data between messages

[Trevor Perrin]

On Sun, Jun 3, 2018 at 7:23 AM, str4d <str4d at i2pmail.org> wrote:
> On 05/29/2018 07:59 PM, str4d wrote:
>> On 05/29/2018 06:28 AM, Trevor Perrin wrote:
>>> I wonder whether the "psk?" modifier approach could be directly
>>> adapted, i.e. if we had an "h?" modifier where you could specify h0,
>>> h1, h2, etc just like psk0, psk1, etc, would that suffice?  Or maybe
>>> you'd want more flexible placement?
>>
>> I think this might suffice. I'll try implementing this in snow and see
>> if it can be made exactly compatible with my existing protocol
>> implementation.
>
> It works! Here is the updated draft extension. The only change I needed
> to make to my existing protocol implementation (after switching the my
> branch of snow with this updated draft implemented) was to add the
> modifiers h1 and h2 to the protocol name.

Nice, glad that works for you!

Looking at your draft text:  It might be more aligned with our
existing tokens and modifiers if we allowed the "h" token to appear
anywhere, and multiple times, even if the "h?" modifier was only able
to place it at the end of messages.

Our current tokens have a lot of flexibility in how they can be
arranged, even though we've named only a small set of these
arrangements via pattern names and modifiers.

(We should probably also think more about potential use cases, and see
if we want the modifier to be capable of more flexible token
placement).

Trevor