Re: [IPsec] ikev2bis issue #185: What do to if you don't ignore INITIAL_CONTACT

Yaron Sheffer <yaronf.ietf@gmail.com> Wed, 31 March 2010 09:26 UTC

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Date: Wed, 31 Mar 2010 12:26:46 +0300
From: Yaron Sheffer <yaronf.ietf@gmail.com>
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To: Paul Hoffman <paul.hoffman@vpnc.org>
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Cc: IPsecme WG <ipsec@ietf.org>
Subject: Re: [IPsec] ikev2bis issue #185: What do to if you don't ignore INITIAL_CONTACT
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Presumably, such implementations would do the same as they normally do 
for INITIAL_CONTACT:

    The INITIAL_CONTACT notification asserts that this IKE SA is the only
    IKE SA currently active between the authenticated identities.  It MAY
    be sent when an IKE SA is established after a crash, and the
    recipient MAY use this information to delete any other IKE SAs it has
    to the same authenticated identity without waiting for a timeout.

The original RFC did not specify that it MUST be sent in a specific 
message, and therefore we'd better leave it somewhat vague instead of 
forcing the protocol to fail otherwise. In particular because the normal 
recipient behavior is a MAY.

Thanks,
	Yaron

On 31.3.2010 2:59, Paul Hoffman wrote:
> s2.4, para 2, says "The INITIAL_CONTACT notification, if sent, MUST be in the first IKE_AUTH request or response, not as a separate exchange afterwards; receiving parties MAY ignore it in other messages."
>
> What should receiving parties do if they *do* receive it and *don't* ignore it? Since it 'MUST be sent in the first IKE_AUTH' receiving at any other time is a protocol error and should cause some response (like dropping the IKE_SA perhaps).
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