[openpgp] Re: Primary Key Binding sigs on authentication subkeys

[Daniel Huigens <[e-mail]>]

Hi Stephan,

I am not proposing to change the specification in this thread.

In the PR that Andrew linked, I proposed to align our implementation
with text in the specification that predates my involvement and is
present in RFC4880, Section 11.1:

   For subkeys that can issue signatures, the subkey binding signature
   MUST contain an Embedded Signature subpacket with a primary key
   binding signature (0x19) issued by the subkey on the top-level key.

Similarly, the idea of authenticating using OpenPGP signatures was not
raised by me but by RFC4880, Section 2.2:

2.2.  Authentication via Digital Signature

   The digital signature uses a hash code or message digest algorithm,
   and a public-key signature algorithm.  The sequence is as follows:
   (...)

If you or anyone else is of the opinion that this text is wrong,
please propose to change it, but surely you'd agree that it's a
good thing for the specification and its implementations to match.


Finally, I'll note that the changes in RFC9580 were not solely
proposed by me but by a group of people, all of whom (in my view)
had the best interest of OpenPGP in mind, and not only for email.
It's a shame that not all implementations were on board and that
things turned out the way they did, but I won't rehash that further
here.

Best,
Daniel