Re: [IPsec] IKEv2 Diffie-Hellman Elliptic curve mess (RFC4753, RFC5114, RFC4869, and draft-solinas-rfc4753bis-01)

  Hi David,

  I don't believe there is an actual "running code" problem. It's
just a documentation problem and the errata corrects it.

  The thing is, _if_ a running code problem exists the proposal to
add new identifiers for the exact same ECP definitions would not fix
it.

  Dan.

On Mon, December 21, 2009 10:54 am, Black_David@emc.com wrote:
> Dan,
>
>>   If we allocate new numbers to do it right then we will, in fact, live
>> forever with an ambiguous interpretation of groups 19, 20, and 21. I
>> agree we should fix the problem and not live with ambiguity. The
>> proposal
>> to allocate new numbers doesn't seem to do that though.
>
> Fine, here's how to accomplish that goal - the RFC that allocates
> the new group numbers should:
>   1) explain why the group numbers 19, 20 and 21 are ambiguous;
>   2) state that group numbers 19, 20 and 21 "SHOULD NOT be used";
>   3) instruct IANA to remove the group number registrations for
> 	19, 20 and 21 in a fashion that prevents reallocation; and
>   4) obsolete RFC 4753.
> That should avoid long term problems.
>
> That said, I'd like to see more reason to believe that there is
> an actual "running code" problem before doing something this drastic.
> If most people working with elliptic curve "just know" that only
> one coordinate is used, we might not have a problem in practice.
>
> Thanks,
> --David
> ----------------------------------------------------
> David L. Black, Distinguished Engineer
> EMC Corporation, 176 South St., Hopkinton, MA  01748
> +1 (508) 293-7953             FAX: +1 (508) 293-7786
> black_david@emc.com        Mobile: +1 (978) 394-7754
> ----------------------------------------------------
>
>> -----Original Message-----
>> From: ipsec-bounces@ietf.org [mailto:ipsec-bounces@ietf.org] On Behalf
>> Of Dan Harkins
>> Sent: Monday, December 21, 2009 1:44 PM
>> To: Yaron Sheffer
>> Cc: ipsec@ietf.org; Yoav Nir; Tero Kivinen
>> Subject: Re: [IPsec] IKEv2 Diffie-Hellman Elliptic curve mess (RFC4753,
>> RFC5114, RFC4869, and draft-
>> solinas-rfc4753bis-01)
>>
>>
>>   Yaron,
>>
>>   If we allocate new numbers to do it right then we will, in fact, live
>> forever with an ambiguous interpretation of groups 19, 20, and 21. I
>> agree we should fix the problem and not live with ambiguity. The
>> proposal
>> to allocate new numbers doesn't seem to do that though.
>>
>>   Dan.
>>
>> On Mon, December 21, 2009 7:48 am, Yaron Sheffer wrote:
>> > Hi Tero,
>> >
>> > I support your position (and disagree with Yoav). We had better fix
>> this
>> > problem now by allocating a few more numbers, than live forever with
>> an
>> > ambiguous interpretation to the numbers that everybody's using.
>> >
>> > Thanks,
>> > 	Yaron
>> >
>> > -----Original Message-----
>> > From: ipsec-bounces@ietf.org [mailto:ipsec-bounces@ietf.org] On Behalf
>> Of
>> > Tero Kivinen
>> > Sent: Monday, December 21, 2009 13:21
>> > To: Yoav Nir
>> > Cc: ipsec@ietf.org
>> > Subject: Re: [IPsec] IKEv2 Diffie-Hellman Elliptic curve mess
>> (RFC4753,
>> > RFC5114, RFC4869, and draft-solinas-rfc4753bis-01)
>> >
>> > Yoav Nir writes:
>> >> If there is such an implementation, then it's not interoperating
>> >> with all the other implementations and should be fixed.
>> >
>> > It is following the published RFC, so why should it be fixed. I think
>> > everybody agreed that making major non-interoperable change in the
>> > errata was not proper way of fixing the thing (there were lots of
>> > developers who had missed that).
>> >
>> > This whole discussion about the errata started because one implementor
>> > was implementing the RFC and wanted to make sure that the y is really
>> > added, and he wanted to make sure that he understood it correctly as
>> > that would eman that those groups cannot be made complient to FIPS
>> > 140-2.
>> >
>> > He had not noticed the errata. There were also other people who had
>> > not noticed the errata (including me).
>> >
>> > I am sure there is also people who do not follow the IPsec list and
>> > still do implement things (following IPsec list is not really
>> > requirement for implementing IPsec).
>> >
>> > I am only person in our office who regularly follow IPsec list and all
>> > others just take RFCs and read them and write code based on them. I am
>> > not sure if any of those people actually even know how to find
>> > errata...
>> >
>> > Made quick poll around the office, and found out that noboby here had
>> > checked any of the errata for any of the RFCs they have worked on.
>> > They said they usually do check for rfc-index to see if the RFC was
>> > updated or obsoleted, but that is it.
>> >
>> >> If someone shipped something like that, then the only reason they
>> >> haven't noticed yet, is because they (1) didn't test it well enough,
>> >
>> > Doing testing against your implementation does not detect that kind of
>> > problem as everything works fine. Also for quite a lot of IPsec
>> > vendors the main goal is to make implementation which works with their
>> > own products and the secondary goal is that it works with other
>> > vendor's product too.
>> >
>> >> and (2) their customers are using some other option like 1024-bit
>> >> MODP group (and 3DES, but that's beside the point)
>> >
>> > That is most likely true for all current IPsec implementations.
>> > Elliptic curves are not really used that much yet. That is the reason
>> > I want to fix this problem now, not move it to future.
>> >
>> >> Anyway, making everyone add a new group "28" just so nobody needs to
>> >> patch their old implementation of group "20" seems like wasted
>> >> effort to me.  We can keep group 20, and fix the spec to prescribe
>> >> what everybody is doing anyway.
>> >
>> > I do not want to see the support request saying that our product does
>> > not interoperate vendor X's product when using group 19 and then later
>> > find out that is because the other vendor has implemented RFC4753
>> > and didn't notice the errata.
>> >
>> > Also it will most likely take our customer and our support quite a
>> > long time before they even realize why recipient of IKE_AUTH will
>> > simply drop the packet because of wrong MAC. After that wasted effort
>> > I know that it will come to me, and I need to explain to our customer
>> > that our code is correct and the other implementation was also correct
>> > when they wrote the code, but they are not correct anymore...
>> >
>> > I do not think the elliptic curves are used that much in the current
>> > IPsec installations, so I think we still have time to fix this problem
>> > properly.
>> > --
>> > kivinen@iki.fi
>> > _______________________________________________
>> > IPsec mailing list
>> > IPsec@ietf.org
>> > https://www.ietf.org/mailman/listinfo/ipsec
>> >
>> > Scanned by Check Point Total Security Gateway.
>> > _______________________________________________
>> > IPsec mailing list
>> > IPsec@ietf.org
>> > https://www.ietf.org/mailman/listinfo/ipsec
>> >
>>
>>
>> _______________________________________________
>> IPsec mailing list
>> IPsec@ietf.org
>> https://www.ietf.org/mailman/listinfo/ipsec
>
> _______________________________________________
> IPsec mailing list
> IPsec@ietf.org
> https://www.ietf.org/mailman/listinfo/ipsec
>