[IPsec] Fwd: Last Call: draft-ietf-ipsecme-ikev2-resumption (IKEv2 Session Resumption) to Proposed Standard

Sorry, I should cc IPsec mail list. Comments are sent again.

Hi, floks:

I have two comments on the draft of IKEv2 Session Resumption:

1) Sorry, I have to talk about my concern on the new
IKE_SESSION_RESUME. In WG last call, actually I made this comment.
However, no feedback was given, maybe because my comment was a little
late for WG last call. So, I just copy it here again as a comment for
IESG last call.

Well,  we've discussed pros and cons of IKE_SA_INIT and
IKE_SESSION_RESUME for quite a long time. However, IMHO, the consensus
is still not fully achieved on this item. So far, I still prefer to
choosing extended IKE_SA_INIT for ticket presenting. This solution is
specified in http://tools.ietf.org/html/draft-xu-ike-sa-sync-01

As a summary, the virtues are as follows:
- RFC5077 (TLS session resumption) also uses the similar scheme, which
extends the message of clienthello with session ticket extension. The
extended IKE_SA_INIT solution has the similar way. It's easy to extend
the base IKEv2 protocol stack to support session resumption.
- Considering the case of failing session resumption, the extended
IKE_SA_INIT solution can save one round trip.
- As indicated in 4.3.3 IKE_AUTH exchange, IKE_AUTH must be initiated
after IKE_SESSION_RESUME. In this sense, the extended IKE_SA_INIT way
need less code to be supported compared with IKE_SESSION_RESUME.

The down side:
- some people thought the way of extended IKE_SA_INIT will make the
base IKEv2 protocol stack more complex. IMHO, it's an issue of
implementation.
Again, I still support to use extended IKE_SA_INIT for ticket
presenting instead of IKE_SESSION_RESUME.

2) Maybe I missed some discussions.
There is the case: responder may receives a ticket for an IKE SA that
is still active and if the responder accepts it. In one of previous
versions of this draft, there once was some description on this case.
I know that how a client detects the need for resumption is out of the
scope of this draft. But, there is the possibility that IPsec client
may be continuously deceived and believe the fail of IPsec gateway. It
may continuously present the ticket and update the ticket. In this
sense, IMHO, this draft should take care of this case.

BRG
Peny

On Mon, Aug 31, 2009 at 10:09 PM, The IESG<iesg-secretary@ietf.org> wrote:
> The IESG has received a request from the IP Security Maintenance and
> Extensions WG (ipsecme) to consider the following document:
>
> - 'IKEv2 Session Resumption '
>   <draft-ietf-ipsecme-ikev2-resumption-07.txt> as a Proposed Standard
>
> The IESG plans to make a decision in the next few weeks, and solicits
> final comments on this action.  Please send substantive comments to the
> ietf@ietf.org mailing lists by 2009-09-14. Exceptionally,
> comments may be sent to iesg@ietf.org instead. In either case, please
> retain the beginning of the Subject line to allow automated sorting.
>
> The file can be obtained via
> http://www.ietf.org/internet-drafts/draft-ietf-ipsecme-ikev2-resumption-07.txt
>
>
> IESG discussion can be tracked via
> https://datatracker.ietf.org/public/pidtracker.cgi?command=view_id&dTag=17990&rfc_flag=0
>
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