I'm having a great deal of trouble understanding the problem you're
trying to describe. As someone who has implemented both RFC 1421 and
PEM/MIME I had no trouble with what I understand to be your problem
(which could be wrong, of course). Let me try to describe what I
perceive to be your problem so I can test my understanding.
The problem is simple. The issuer name and serial number (in the old
RFCs) are integral to the public key trust mechanism, the certificate.
There is a one-to-one correspondance. I can always derive the issuer
name and serial number from a certificate whether I got your
certificate from you, from a friend, from my system administrator, a
mail message to a distribution list, an X.500 server or anywhere else.
The same is true for the public key (or even a hash of the public key
for those who are concerned with bandwidth). There is considerable
simplicity and elegance in the idea that the "selector" field for my
database simply CAN NOT get out of sync with the actual keys in the
database. That goes for the keys of my communicants (for outgoing
mail) as well as my own keys (for incoming mail). End of story.
It is not at all compelling to me to hear how easy it was for you to
add this to your reference implementation. Of course it's easy !!! Of
course it's interoperable !!! You wrote it !! Now explain to me what
my application is supposed to do when someone encrypts a message with
my public key with a key selector I've never seen before. This is
just one example of an out-of sync comdition. For n different
identifiers there are about n squared of these conditions to deal
with. None of this is addressed in the current spec and to do so may
take more pages then the existing text !!
My proposal is to settle on one identifier. Let's make it work.
Let's make it interoperate. Now !! Nothing will stop us from making
it better later. I tend to agree with Dave Crocker's repeated pleas,
we're very late. Anything, ANYTHING we can do to speed implementation
must be given consideration at this point.
Dare to be simple. It goes a long way !!!
Holiday cheers,
Steve Dusse
RSA
p.s. Please forgive the frustrated tone. I;m actually very pleased
that there is discussion after so long a silence,.,,,,,,