Subject: [mobile-ip] IPsec, IKE, MIPv6 and concensus

From: "Hesham Soliman (ERA)" <[email-masked]>
Date: Thu, 16 Aug 2001 23:20:19 +0200

Hi, 

During the meeting Phil had asked me to write something up to 
describe the problem with IPsec usage and some suggestions. 
Obviously as we all know (or some of us) Mike Thomas already wrote 
a draft for ESP, also Pekka sent a very long mail on the general 
topic, so I'm not sure if a draft would add more to what we discussed. 

Therefore I thought perhaps getting some concensus on IPsec
usage would be a good idea. 

First let me summarise briefly the two problems we're having:

1. Relying on IKE only as a key exchange mechanism is not 
   acceptable (This was discussed several times and I think we 
   all agree on this assumption)

2. There are some issues to be resolved if IPsec is to be used. 
    Mainly this is related to the recent discussions on IPsec selectors
    and their granularity. 

Before London, we agreed that (2) can be solved in 2 different ways:

   A. Use a new Ext Header value for MIPv6 BUs. This will not 
       involve any modifications to the IPsec implementations.
   
   B. Add some text to the draft to explain that all implementations 
       for MNs and CNs (receiving BUs only) MUST increase the 
       granularity of their IPsec implementations to search for the 
       BU option instead of relying on the nxt Header value only. 

Of course both A and B rely on eliminating piggybacking of the BUs. 

Problem (1) is addressed by several proposals. Needless to say that
1 and 2 are not dependant on each other (or need not be).

So the questions that should be answered IMO are:

1. Do we want to completely disallow the use of IKE ?

2. Do we want to completely disallow the use of IPsec ?

I guess based on the WG concensus this should be reflected
in the draft so we can get on with our implementations.

What do people think ?

My answer to both questions is No. I do believe that there will
be cases where strong authentication will be required. Since 
there are ways of allowing the use of both IKE (as an option)
and IPsec (whether its AH or ESP) then I don't see why we can't
reuse them. 

Regards,
Hesham

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From: Vijay Devarapalli <[email-masked]>
Date: Thu, 16 Aug 2001 15:34:35 -0700

> 1. Do we want to completely disallow the use of IKE ?

NO.

> 2. Do we want to completely disallow the use of IPsec ?

YES. use authentication data suboption for the BU.

vijay

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From: Erik Nordmark <[email-masked]>
Date: Fri, 17 Aug 2001 11:11:59 +0200 (CEST)

>    all agree on this assumption)

I think the placement of "only" above can be a source of confusion -
IKE is only ("nothing but") a key exchange mechanism as far as I know.

Did you really mean
	Relying on IKE as the only key exchange mechanism used to secure
	Mobile IPv6 is not acceptable ...

> So the questions that should be answered IMO are:

Presumably these questions are solely in the context of
securing MIPv6 or perhaps just securing the BUs, or perhaps just securing
the BUs with CNs?.

I can see folks wanting to use IKE and IPsec to build VPNs to mobile nodes.
Thus I think we need more context in order for folks to agree
what the questions mean.

> 2. Do we want to completely disallow the use of IPsec ?

  Erik

---

From: Francis Dupont <[email-masked]>
Date: Fri, 17 Aug 2001 17:45:16 +0200

=> there are two extra issues:
 - the authentication/authorization problem and the lack of a global PKI
   (not a real IPsec problem)
 - the cost/performance of using IPsec (this seems more a IKE problem
   than a general IPsec problem IMHO but do we agree about that?)

      
=> note this extension header must be final (and of course UDP with
a well known port does the job in 256 time cheaper way :-).

=> we should push this idea for ICMPv6 first and when the door will be
open come back...

=> Yeh!

   
   
=> no, if we have already a phase 1 it will be stupid to do
something different than a phase 2 to get SAs.

=> please don't!

   What do people think ?
   
=> see above.

=> I agree.

Regards

[email-masked]

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From: Alexis Olivereau <[email-masked]>
Date: Fri, 17 Aug 2001 12:33:17 +0200

> 1. Do we want to completely disallow the use of IKE ?
No. As long as other solutions of key exchange are retained, we do not
need to discard this one.

> 2. Do we want to completely disallow the use of IPsec ?
No. IMHO we should work to make MIPv6 & IPsec work together (solutions A
or B you mentioned). I think that a decision to disallow the use of
IPsec would eventually be regretted in a next future. If we envision a
world with fully deployed MIPv6 along with IPsec-based VPNs no doubt
that a single security standard will be more than desirable.

Regards,
Alexis.

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From: Michael Thomas <[email-masked]>
Date: Sun, 19 Aug 2001 14:27:12 -0700 (PDT)

> YES. use authentication data suboption for the BU.

   Since this requires a new DOI for IKE, your
   answers are mutually contradictory. 

	   Mike

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From: Vijay Devarapalli <[email-masked]>
Date: Mon, 20 Aug 2001 10:01:03 -0700

>    Since this requires a new DOI for IKE, your

i never said it did not.

vijay

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From: Jean-Michel COMBES <[email-masked]>
Date: Mon, 27 Aug 2001 18:55:00 +0200

Hi,

> 1. Do we want to completely disallow the use of IKE ?

JMC : No

> 2. Do we want to completely disallow the use of IPsec ?

JMC : No

Regards.
JMC.

--

France Telecom R&D - DTL/SSR
Jean-Michel COMBES, Internet/Intranet Security
E-Mail : [email-masked]
Phone +33 (0)1 45 29 45 94, Fax +33 (0)1 45 29 65 19
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