Subject: Sending a CMP message as a broadcast

From: "Luciano da Silva Coelho" <[email-masked]>
Date: Mon, 2 Dec 2002 18:07:12 -0300

Hi Guys,

    When a CA need to send a message for all your users, for example a
CMPCAKeyUpdateMessage, How must it specify the recipient field in the CMP
Header? The CA must create a message for each one user, or can it do
something like a Broadcast?
    My specific doubt is: Can the recipient field in the CMP Header be set
as a NULL-DN? And in this case, Can the receivers handle this message as a
broadcast information?

    Thanks a lot.

    Luciano Coelho
    [email-masked]
    e-Sec Data Security Technology
    http://www.esec.com.br

---

From: [email-masked] (Peter Gutmann)
Date: Tue, 3 Dec 2002 17:21:22 +1300 (NZDT)

"Luciano da Silva Coelho" <[email-masked]> writes:

>My specific doubt is: Can the recipient field in the CMP Header be set as a
>NULL-DN? And in this case, Can the receivers handle this message as a
>broadcast information?

During interop testing I found several CAs which couldn't handle NULL DNs.  I
worked around it by adding semi-arbitrary DNs on a case-by-case basis until I
got something which worked (some CAs require a certain DN, some seem to accept
any old DN but modify it in the response, so you just copy what's in there
into your next request, and some don't care about DNs).

FWIW in my implementation I ignore DNs, so you can put in anything you like.

Peter.