Re: [Sks-devel] primary uid flag

[David Shaw]

On Mon, Jan 26, 2004 at 09:31:05AM -0500, Yaron M. Minsky wrote:
> I've been looking into this a little further.  I think the problem is
> that I have the wrong algorithm for figuring out whether a key is
> primary.  Right now I do it by checking if any of the signatures
> indicate that the key is primary.  By this metric, the quickie.net key
> IS a primary uid, since it does have at least one signature that claims
> that it is primary.
> 
> So, if that algorithm is wrong, what's right?

The primary UID is the UID that has a set primary UID subpacket on its
self signature.  If there are more than one UID that fit this
description, pick the one with the most recent self signature.  Note
that the mere presence of the primary uid subpacket is not enough.
The value of the subpacket must be 1.  (It is possible to have a
primary UID subpacket set to zero which means "this UID isn't
primary").

> I don't have the RFC in front of me.  Anyone know how I figure out
> which packet is the self-sig?

When the "issuer" subpacket equals the key ID of the key.

David