Re: [openpgp] Transport public keys inside the message body

[Kai Engert <[e-mail]>]

Hi Simon,

On 15.02.24 09:02, Simon Josefsson wrote:
> I re-read RFC 3156 and one way to do this is "extend" it by allowing
> putting a public key block before or after the '-----BEGIN PGP
> MESSAGE-----' block, and say that MUAs can parse those blocks to find
> keys.  Yes, that is a bit ugly, but overall complexity is lower than
> having multipart MIME blobs with an extra application/pgp-keys
> component, and solves the problem of locating which public key was (by
> the sender) intended for use with the signature.

As I understand it, your proposed solution is limited to transport the 
key in signed and/or encrypted messages.

It might be useful to specify a mechanism to transport the key in 
messages that are neither signed nor encrypted, and which don't include 
a "BEGIN PGP MESSAGE".

A more general solution could allow users to include their public key in 
all messages they send.


> Maybe the old OpenPGP: e-mail header with fingerprint and URL should be
> revived...  https://josefsson.org/openpgp-header/ and
> https://datatracker.ietf.org/doc/html/draft-josefsson-openpgp-mailnews-header

I don't mind encouraging MUAs to include this header, if possible, but 
it seems the header couldn't solve the goal for a significant number of 
users, who may not know how to make their public key accessible at an URL.

Kai