Subject: [pcp] draft-ietf-pcp-base: security considerations and transaction ID

From: Sam Hartman <[email-masked]>
Date: Mon, 26 Mar 2012 05:23:34 -0400

Hi.
I contributed significantly to the security considerations section that
is in the current PCP base document.
Last night I was talking to eno of the authors about the PCP discuss
positions and particularly the discussion of a transaction ID.
He pointed out that PCP is not a request/response protocol.
In particular, clients are expected to act on unsolicited PCP responses
including new or updated mappings even if there is not a recent request
for them.

The security analysis we performed assumed that PCP is a
request/response protocol. The current text is inaccurate. The obvious
thing is that there is a greater attack window than is implied by the
current text.

It's going to take me a day or two to think through the implications of
this.
It may be that this does not impact the results of the analysis and just
impacts security considerations text.

I doubt I will have fully thought this through by the meeting today. I'm happy
to attend that meeting if requested, although it was not currently in my
plan.  I will not be able to make the meeting tomorrow as I'll be
co-chairing a session, but the other authors of
draft-wasserman-pcp-authentication will be there.