Re: [openpgp] Embedded TPK subpacket

[Vincent Breitmoser <[e-mail]>]

> Why would it be restricted to sign-only messages?  My proposal also
> works with OpenPGP's usual sign-then-encrypt messages.  Marcus'es point
> was about it not working with encrypt-only messages.

I didn't think it would be restricted to that, but I assumed this would be
a common purpose for the mechanism given you were talking about obsoleting key
management/discovery schemes.

> "get minimal own public key" according to
> https://autocrypt.org/level1.html#openpgp-based-key-data seems pretty
> involved to me.  I'd be surprised if one can even implement that using
> the various OpenPGP implementations out there.  Same for the filtering
> of keys to be gossiped.

Well, "export minimal public key" functionality should probably be part of
a general purpose OpenPGP implementation. You're right that it might be tricky
to get this particular flavor right, but it's not super important to have the
exact structure in practice (however, see below).

> (I just noticed that I cannot do Autocrypt with my key because my
> primary key is not signing-capable...)

Indeed, we should change that to a SHOULD. Looking at it now I'm surprised we're
so strict there, it's good to have a proper recommendation but any minimal key
format should be at least acceptable there. Thanks for the hint, I'll make
a PR :)

 - V

(I'll drop this line of questioning here since it's not really on topic)