Re: [sidr] Stephen Farrell's Discuss on draft-ietf-sidr-rpsl-sig-11: (with DISCUSS and COMMENT)

[Brian Haberman <[e-mail]>]

One further point... Dropping step 1 in section 3.2 is one part of this
change. I think that the fourth bullet in section 5 can be dropped as
well.  Thoughts?

Regards,
Brian

On 5/19/16 8:11 AM, Brian Haberman wrote:
> Hiya Stephen,
> 
> On 5/18/16 5:23 PM, Stephen Farrell wrote:
>>
>> Hi Sandy,
>>
>> On 18/05/16 22:12, Sandra Murphy wrote:
>>> comments inline.  speaking as a regular ol’ wg member
>>>
>>> On May 18, 2016, at 12:20 PM, Brian Haberman
>>> <[e-mail]> wrote:
>>>
>>>> Hiya Stephen,
>>>>
>>>> On 5/18/16 12:09 PM, Stephen Farrell wrote:
>>>>>
>>>>> Hiya,
>>>>>
>>>>> On 18/05/16 17:06, Brian Haberman wrote:
>>>>>> Hiya Stephen,
>>>>>>
>>>>>> On 5/18/16 11:51 AM, Stephen Farrell wrote:
>>>>>>> Stephen Farrell has entered the following ballot position
>>>>>>> for draft-ietf-sidr-rpsl-sig-11: Discuss
>>>>>>>
>>>>>>> When responding, please keep the subject line intact and
>>>>>>> reply to all email addresses included in the To and CC lines.
>>>>>>> (Feel free to cut this introductory paragraph, however.)
>>>>>>>
>>>>>>>
>>>>>>> Please refer to
>>>>>>> https://www.ietf.org/iesg/statement/discuss-criteria.html for
>>>>>>> more information about IESG DISCUSS and COMMENT positions.
>>>>>>>
>>>>>>>
>>>>>>> The document, along with other ballot positions, can be found
>>>>>>> here: 
>>>>>>> https://datatracker.ietf.org/doc/draft-ietf-sidr-rpsl-sig/
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>> ----------------------------------------------------------------------
>>>>>>>
>>>>>>>
>> DISCUSS:
>>>>>>> ----------------------------------------------------------------------
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>> I'd like to check one thing - this may be needed for strict
>>>>>>> compliance with RPKI thing but it seems kinda weird to also 
>>>>>>> impose that here, but anyway...
>>>>>>>
>>>>>>> Is 3.2 step 1 needed?  That seems like useless complexity 
>>>>>>> here.  If it is needed, how does the verifier check that it's
>>>>>>> really a single-use? I don't see the point TBH.
>>>>>>>
>>>>>>
>>>>>> This text was driven by the statement in RFC 6487 (Section 3)
>>>>>> that says:
>>>>>>
>>>>>> The private key associated with an EE certificate is used to
>>>>>> sign a single RPKI signed object, i.e., the EE certificate is
>>>>>> used to validate only one object.
>>>>>>
>>>>>> Step 1 in 3.2 is there so that this approach follows the above
>>>>>> directive on the use of the RPKI infrastructure/certificates.
>>>>>
>>>>> Well... sure. But what is the benefit here? IIRC that was
>>>>
>>>> I *think* the benefit is supposed to be compliance with the RPKI
>>>> approach...
>>>>
>>>>> something related to making more fine-grained revocation possible
>>>>> or something which doesn't seem that useful here since a verifier
>>>>> will likely already have processed stuff already or am I mixed
>>>>> up?
>>>>
>>>> I don't think you are mixed up, but I will let others in SIDR chime
>>>> in…
>>>
>>> There was at one point in the history of resource certificates the
>>> idea that EE certs could be used multiple times.  (EE certs even had
>>> their own manifests!)
>>>
>>> The signed object definition encapsulated the EE cert used to verify
>>> the signature.  That revocation of the signed object could be
>>> accomplished by revoking the EE cert.  Which meant that the EE cert
>>> should be used just to sign that one object, as Stephen says.
>>> (otherwise chaos ensues)
>>>
>>> As the only defined use of EE certs at the time of the publication of
>>> 6487 was the use to verify signed objects, the text about EE certs
>>> was reduced to just that necessary to support the single-use.
>>>
>>> This is different.  The validity of the rpsl object is not tied to
>>> the validity of the EE cert.  The comments from the wg were that this
>>> draft should talk about the syntax of the new attribute, not the
>>> authorization/semantics.  So revocation of the EE cert in this case
>>> would/might not have the effect of revoking the rpsl object.  I
>>> personally don’t think it likely that it ever will, but that’s IMHO
>>> only.
>>>
>>> So it is a moot question as to whether the single-use is a part of
>>> “the RPKI approach” for this rpsl-sig use.
>>
>> But that means that there is no reason to include the requirement
>> here then or am I missing something? Deleting that "step" in the
>> signing process would seem like a good idea so. (Assuming that
>> current implementers, if any, are fine with that.)
> 
> As one implementer, I have no problem dropping this step. There is
> nothing in my RPSL code that enforces this (it is a function of the RPKI
> EE cert usage).
> 
>>
>>>
>>>>
>>>>>
>>>>> If there's no benefit, it seems like that adds a bunch of CA code
>>>>> just for fun (or "compliance" maybe;-)
>>>
>>> curious: how would this single-use requirement add anything to the CA
>>> code?  If the requirement is in 6487, the CA code would already have
>>> the checks.  I ask only because I might be missing something.
>>
>> What I was trying to say was that requiring signers of this to
>> include all the CA code is the problem/oddity, esp if there's no
>> real benefit.
>>
>> So the single-use thing doesn't add to the CA code, it adds a
>> need for the CA code in the wrong place.
>>
>> And I guess if the spec says "once only" then I can well imagine
>> some poor verifier implementer keeping some kind of cache and
>> checking it'd not seen a signature before or something like that.
>> And that'd also be kinda pointless code too I think.
> 
> I certainly don't do any type of checking at the verification step.
> 
> Regards,
> Brian
>