Re: [Hipsec] Need to close all draft-ietf-hip-dex-21 pending issues... before 2021-Jan-13...

[Robert Moskowitz <[e-mail]>]

On 1/18/21 9:12 AM, Eric Vyncke (evyncke) wrote:
> Standard
>
> TD ;LR : more work to be done, deadline this Thursday 21st
>
> Bob,
>
> Thank you for the -23 (and Adam W for the footwork)and I understand 
> that you are quite busy.
>
> Here is the link to the diff between -21 and -23: 
> https://www.ietf.org/rfcdiff?url2=draft-ietf-hip-dex-23&url1=draft-ietf-hip-dex-21 
> <https://www.ietf.org/rfcdiff?url2=draft-ietf-hip-dex-23&url1=draft-ietf-hip-dex-21> 
> (i.e., the one used by July 2020 IESG evaluation and the latest one)
>
> After the July 2020 IESG evaluation based on -21, there were a couple 
> of points to be addressed(with some comments of mine as EVY>):
>
>   * Roman: “Section 6.3.  Per the definition of IKM, when should these
>     two different derivations be used? "
>       o EVY> indeed, IKMm and IKMp are both defined but nothing is
>         said which one to use in which case.
>

        IKM       IKMm for Master Key SA Input keying material
                  or
                  IKMp for Pair-wise Key SA Input keying material

        IKMm      Kij | I_NONCE
        IKMp      Kij | I_NONCE | (concatenated random values of the
                      ENCRYPTED_KEY parameters in the same order as
                      the HITs with sort(HIT-I | HIT-R))

Seems clear that IKMm is for the Master Key SA and IKMp is for the 
Pair-wise Key SA.

>   * Roman "discuss-discuss" (read this as request for reply and
>     non-blocking) about "further implementation experience provides
>     better guidance" in sections 6 and 9.
>       o EVY> this really pleads for experimental status
>

The only place this text exists anymore is in Appendix C:  iESG 
Considerations

Perhaps I should delete it from there.

>      o
>
>
>   * Benjamin on FOLD collisions
>       o EVY> IMHO addressed in the new section 3.2.1
>

I believe I have this covered.  We have the Python scripts for tests, 
but this is a lot of code to put into the document.  Right now it is 
privately held by Adam and I.  If called on, we can find some permanent 
home for it.

>      o
>
>
>   * Benjamin on ACL to counter FOLD collisions in section 3.2.1
>       o EVY> still light on the ACL but the above should clear it
>

Sec 7.1 is referenced.

>      o
>
>
>   * Benjamin "how is it known that the peer should be using DEX vs. BEX"
>       o EVY> partially addressed in section 1.2 but should be repeated
>         in the security section
>

I can create a sec 9.1 (pushing down the current 9.1):

9.1 Caution on using HIP DEX rather than HIP BEX

    Due to the substantially reduced security guarantees of HIP DEX
    compared to HIP BEX, HIP DEX MUST only be used when at least one of
    the two endpoints is a class 0 or 1 constrained device defined in
    Section 3 of [RFC7228]).  HIP DEX MUST NOT be used when both
    endpoints are class 2 devices or unconstrained.


Will this work?

>      o
>
>
>   * Benjamin lack of discussion on the security consequences of
>     inadvertent counter reuse in AES-CTR
>

See sec 9.1

>  *
>
>
>   * Benjamin "presence of a CSPRNG in order to obtain secure session keys"
>

9.  Security Considerations

....

    *  The strength of the keys for both the Master and Pair-wise Key SAs
       is based on the quality of the random keying material generated by
       the Initiator and the Responder.  As either peer may be a sensor
       or an actuator device, there is a natural concern about the
       quality of its random number generator.  Thus at least a CSPRNG
       SHOULD be used.


>  *
>
>
>
>   * Benjamin "usage of CMAC instead of HMAC" about KEYMAT algorithm
>       o EVY> new reference to NIST papers seems to address this concern
>

Ben did agree in an email that the SP800-56C and 108 addressed the 
concern.  I did not need to go further.

>      o
>
>
>   * Ekr’s one about why forfeiting FS when some algorithm could do it
>     in a reasonable time. In an email to authors and ADs, Eric R.
>     wrote “it defines a set of parameters (the NIST curves) which are
>     slower w/o FS than other parameters (X25519) are w/ FS. This fact
>     calls into question the need to dispense with FS.”
>       o EVY> the additional section 1.2.1 and the reference to a
>         paywall EfficientECC reference do not offer a conclusive
>         motivation for an IETF standards w/o FS.
>

Paywall?  Hmm.  I got it free.  I will have to check into this.  It may 
be to some cookie I have on this system.  Or the DOI has the wrong URL.

Ah, that URL works for me because I am an IACR member.  For all else:

https://link.springer.com/article/10.1007/s10623-015-0087-1

So I will change the reference.  But please check this out.  I tried it 
on another machine that should not have my IACR cookies, but...



>      o
>
>
>
>
> ***Bottom line, the document is not yet ready to be approved.*** (even 
> if big progress has been made)
>
> As written in November (see below), the situation has lingered for too 
> long and is blocking the HIP-NAT and rfc4423-bis documents.
>
> *** Therefore, I request the authors for a revised I-D addressing the 
> above (and noting again that a change to ‘experimental’ – as there are 
> no deployed implementations – could probably fix all of them) before 
> Thursday 21st of January midnight UTC else I will ask the HIPSEC WG to 
> agree removing the HIP-DEX section from the architecture document. ***
>

Does the above address the open items?

> All in all, there have been a couple of significant changes (I_NONCE, 
> some deleted ciphers) since the IETF last call (see 
> https://www.ietf.org/rfcdiff?url2=draft-ietf-hip-dex-23&url1=draft-ietf-hip-dex-21 
> <https://www.ietf.org/rfcdiff?url2=draft-ietf-hip-dex-23&url1=draft-ietf-hip-dex-21> 
> ), so, another IETF Last Call is required but should not be a real 
> problem.
>
> -éric
>
> From: Robert Moskowitz <[e-mail]>
>
> Date: Thursday, 14 January 2021 at 16:08
>
> To: Eric Vyncke <[e-mail]>, "Eric Vyncke (evyncke)" 
> <evyncke=[e-mail]>, "[e-mail]" 
> <[e-mail]>, "[e-mail]" 
> <[e-mail]>, Miika Komu <[e-mail]>
>
> Cc: Roman Danyliw <[e-mail]>, Eric Rescorla <[e-mail]>, 
> Gonzalo Camarillo <[e-mail]>, 
> "[e-mail]" <[e-mail]>, Benjamin Kaduk 
> <[e-mail]>, Erik Kline <[e-mail]>
>
> Subject: Re: [Hipsec] Need to close all draft-ietf-hip-dex-21 pending 
> issues... before 2021-Jan-13...
>
> I had hoped to get -23 out end of last week, and missed my cutoff.  I 
> am now in IACR's Real World Crypto, where I have gotten a couple 
> pointers for DRIP work.
>
> I was waiting for two analyzes that I got Jan 4, and incorporating 
> them in.  I believe these SHOULD address much of EKR's questions.
>
> I will have a run of 1M DEX random HIs to HITs generated with no 
> duplicates that I add in an Appendix along with the Python code.
>
> I am adding a BEX/DEX crypto cost into 1.2, probably 1.2.1:
>
> For an Initiator, BEX is:
>
> 2 PK sig varifications.
>
> 1 PK sig generation.
>
> 1 DH keypair generation.
>
> 1 DH secret derivation.
>
> DEX is:
>
> 1 DH secret derivation.
>
> I have cycles for these and a paper to reference, except ECDH keypair 
> generation, on an 8 bit process and the numbers are big.  But I think 
> that part belongs in an Appendix.
>
> So unlikely Friday.  But early the following week.
>
> On 1/12/21 6:19 AM, Eric Vyncke (evyncke) wrote:
>
> Two months after the email below, I sending a kind reminder to authors 
> and WG.
>
> With the -22, a lot of (if not all ) SEC ADs’ DISCUSS points should 
> have been addressed.
>
> As far as I can tell, the other remaining issue was Ekr’s one about 
> why forfeiting FS when some algorithm could do it in a reasonable 
> time. In an email to authors and ADs, Eric R. wrote “it defines a set 
> of parameters (the NIST curves) which are slower w/o FS than other 
> parameters (X25519) are w/ FS. This fact calls into question the need 
> to dispense with FS.”
>
> While 2 months ago I put a deadline for tomorrow, I (as the 
> responsible AD) am flexible of course but we cannot linger anymore. I 
> know that a -23 is in the work for weeks => let’s publish it in the 
> coming days.
>
> Else, next week we will need to either change the intended status to 
> experimental or declare the document dead by lack of energy. The 
> latter does not have my preference obviously.
>
> Regards
>
> -éric
>
> From: Hipsec mailto:[e-mail] on behalf of "Eric Vyncke 
> (evyncke)" mailto:evyncke=[e-mail]
>
> Date: Friday, 13 November 2020 at 15:32
>
> To: mailto:[e-mail] mailto:[e-mail], 
> mailto:[e-mail] mailto:[e-mail], 
> Robert Moskowitz mailto:[e-mail], Miika Komu 
> mailto:[e-mail]
>
> Cc: Roman Danyliw mailto:[e-mail], Eric Rescorla 
> mailto:[e-mail], Gonzalo Camarillo 
> mailto:[e-mail], mailto:[e-mail] 
> mailto:[e-mail], Benjamin Kaduk mailto:[e-mail], 
> Erik Kline mailto:[e-mail]
>
> Subject: [Hipsec] Need to close all draft-ietf-hip-dex-21 pending 
> issues... before 2021-Jan-13...
>
> Dear HIP, dear authors,
>
> This document was requested for publication [1] in February 2018 (2.5 
> years ago), then its IESG evaluation has been deferred, then I took 
> over this document from Terry Manderson in March 2019, then it went 
> again through IESG evaluation in July 2020 and there are still DISCUSS 
> points to be addressed even after a couple of revised I-D...
>
> Difficult not to observe that this document does not progress very fast.
>
> Moreover, this document is a normative reference for rfc4423-bis 
> waiting in the RFC editor queue since March 2019... So, also blocking 
> the HIP-NAT document [2].
>
> After discussion with the HIP chair, Gonzalo in cc, we have taken the 
> following decision: if a revised I-D addressing remaining DISCUSS 
> points + Ekr’s ones is not uploaded within 2 months (13th of January 
> 2021), then I will request the HIP WG to accept the complete removal 
> of section A.3.3 of the rfc4423-bis document (1 page about HIP-DEX in 
> the appendix) + the reference to the HIP-DEX document [3]. This will 
> allow the immediate publication of the rfc4423-bis and HIP-NAT documents.
>
> The HIP DEX authors may also select to change the intended status of 
> the document to ‘experimental’ (if the HIP WG agrees) as this may 
> reduce the security requirements by the SEC AD and Ekr.
>
> Gonzalo and I are still hoping to get a revised HIP-DEX shortly,
>
> Regards
>
> -éric
>
> [1] https://datatracker.ietf.org/doc/draft-ietf-hip-dex/history/
>
> [2] https://www.rfc-editor.org/cluster_info.php?cid=C386
>
> [3] and possibly I will set the state of HIP-DEX as ‘dead’ on the 
> datatracker
>
> -- 
>
> Robert Moskowitz
>
> Owner
>
> HTT Consulting
>
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>
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>
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>
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