On Thursday 13 January 2005 02:01 am, "Hal Finney" wrote:
At PGP Corporation we are planning on adding a notation packet to newly
generated keys. It is intended to let key holders indicate whether they
can receive PGP/MIME email, or an alternate format used by PGP, or both.
<... snip ...>
An example preferred-email-encoding notation packet will have the
following fields:
Flags: 0x80, 0x00, 0x00, 0x00
Name: preferred-email-encoding(_at_)pgp(_dot_)com
Value: pgpmime,partitioned
This would mean that the key holder can handle both PGP/MIME and
partitioned formats, but that he prefers to receive PGP/MIME.
I think that this is a great idea. This kind of preference support is a
critical feature for one of the most used applications of OpenPGP.
Hal,
You describe adding a notation packet to a *key*. Section 5.2.3.16. "Notation
Data" describes only notation packets on a *signature*
"This subpacket describes a "notation" on the signature that the
issuer wishes to make. The notation has a name and a value, each of
which are strings of octets. There may be more than one notation in
a signature. Notations can be used for any extension the issuer of
the signature cares to make."
Can you please clarify? Is your packet on the signature, or the key?
For context, I work on the OpenPGP implementation for Squirrelmail, an open
source mail client. Our implementation uses GnuPG 'underneath' to do the
encryption. I only see support in gpg for adding/examining notation packets
on *signature* data, not notations on *keys*.
We'll certainly implement the functionality that Hal describes, if gpg
supports setting and extracting the notation packet required. From what I
can tell, this will require setting/checking the notation packet on the
signature of the message.
I spoke up on the issues around PGP/MIME on this list several times in the
past. I wish that this kind of standardization would show up *in the RFC*,
as I've previously indicated.
Hal, thanks again for the detailed message and any clarifying response.
Regards,
- Brian