BTNS meeting notes
These are the minutes for the Better than nothing security (BTNS)
working group meeting, held at IETF-64 on Thursday, Nov 10, 2005, in
Vancouver. Thanks to Jeffrey Altman, Leif Johansson, Michael
Richardson and Pekka Nikander for the notes on which these minutes are
based. Note that these minutes do not follow the typical IETF minutes
format, transcribing the discussion, but are on a more condensed
Chairs: Love Hoernquist Aastrand and Pekka Nikander
* Working group background
Three different groups/interests:
* protection against off-path attackers
* working towards channel binding
* SSH-like leap-of-faith use of IPsec
The working group was chartered to:
* specify extensions to IPsec so that IPsec will support
creation of unauthenticated SAs.
* enable and encourage simpler and more rapid deployment of
* Goals for the meeting
* Complete discussion on Problem statement and applicability
* Confirm direction of the SPD/PAD/IKE extensions document.
* Other technical discussions.
* Update milestones
* Decisions made
1. Adopt Nico BTNS document (draft-williams-btns-00.txt) as a
working group item.
2. Update milestones as proposed by Love.
* Current outstanding issues
Some of these question where asked during the meeting (by
group and chairs):
- is leap-of-faith really in scope?
- leap-of-faith with changing addresses.
- when SA going away, and exsting streams
get sent in clear-text, how does this affect BTNS,
- what details for the SPD/PAD extensions?
- ANY/UKNOWN in PAD/SPD.
- how do you detect BTNS?
- should self-signed certificates or raw keys be used?
- Is it OK to allow clear text traffic and then later kick in
* Action items
* Publish next version of the Problem and Applicability
Statement hopefully in the beginning of December. Joe,
* Get more review of the Problem and Applicability Statement,
* Publish next version of Nico draft as a working-group item,
* Add text in Nico draft how to the use-cases in Problem and
Applicability Statement is used, Nico.
* Current work
* Problem statement and applicability statement
* An Unauthenticated Mode of IPsec
* Points to pay attention to
* Leap of faith is hard, maybe we shouldn't try to solve all
problems related to this.
* Describe the problems in Applicability and Problem statement
that we can check if we solve in subsequent document.
* Presentation: Discussion on Applicability and Problem statement
Joe Touch made a presentation on the Problem and Problem
statement draft. He had recived comments from about 5 people
on the draft.
Joe thought he would have a updated draft out by the end of
the month or early December. There are known open issues, the
editors would send mail to the people the made the comments
and see if they comments are addressed. And if it was not, ask
the person to clarify the issue.
* Presentation: An Unauthenticated Mode of IPsec
Nico Williams made a presentation about his individual
submission about how to implement the BTNS using IKE by
introducing new states to either PAD and/or PAD.
The issue if UNKNOWN in SPD was really the right solution came
up, and it was some discussion if UNKNOWN should live in the
PAD or the SPD,
Steve Kent voiced concerned that draft needs to prove why this
approach does not break existing access control.
Sam Hartman would like to see use-cases in the draft, show its
possible to solve the problems given in the problem statement.
There as a good discussion about how leap-of-faith mode could
work. The where consensus that having a leap-of-faith mode was
hard, but not impossible.
Michael Richardson points out that in the case where the peer
goes away and the SA is killed any data that still is in
progress will go out in clear-text on the wire. Nico Williams
confirms that this is an issue for standalone BTNS. Sam
Hartman thinks this need to examined, at the very least
mentioned in the Security Considerations section.
* Updating milestones
Updated milesstones a proposed by Love, no commentes received
during the meeting.
Old New Milestone
Sep 05 Sep 05 First version of SPD and/or PAD extensions draft
Oct 05 Jan 06 WG LC on problem and applicability statement (a+b)
Oct 05 Jan 06 First version of IKE extensions draft (if needed)
Nov 05 Feb 06 First version of IPsec interfaces draft (e)
Nov 05 Feb 06 Submit problem and applicability statement to IESG (a+b)
Jan 06 Mar 06 WG LC on IKE extensions (c)
Jan 06 Mar 06 WG LC on SPD and/or PAD extensions (d)
Feb 06 Apr 06 Submit IKE extensions to the IESG
Feb 06 Apr 06 Submit SPD and/or PAD extensions to the IESG
Mar 06 Jun 06 WG LC on IPsec interfaces draft
Mar 06 Jun 06 Submit IPsec interfaces draft to the IESG
Mar 06 Mar 06 Recharter or close the WG
* Other issues