Re: [Taps] Paul Wouters' Yes on draft-ietf-taps-interface-24: (with COMMENT)

[Paul Wouters <[e-mail]>]

This all looks good. Thanks for the long write up.

Once you have published an updated draft, I will move my Ballot to Yes.

Paul


Sent using a virtual keyboard on a phone

> On Jan 2, 2024, at 07:44, Michael Welzl <[e-mail]> wrote:
> 
> Dear Paul,
> 
> I now see what happened here. I have made this harder to track by answering the DISCUSS items only in my email - when, in fact, we have addressed or at least discussed everything on github. I’m sorry!  There were so many emails, I also didn’t want to make the answers too long.
> 
> As a general comment, for everyone else who might see this: if you miss answers to your COMMENTS, we’re sorry!  - but you’re likely to find them fast by going to:
> https://github.com/ietf-tapswg/api-drafts/issues
> … removing “is:open” from the search field but instead writing your last name there.
> 
> 
> Paul, please see below:
> 
> 
>> ----------------------------------------------------------------------
>> COMMENT:
>> ----------------------------------------------------------------------
>> 
>> I updated my discuss items to non-blocking comments. I'm still a bit concerned
>> that some security items are not fully addressed by the API or its Security
>> Considerations. Resolving my comments would make the document a bit more clear
>> and useful I think.
>> 
>> I'm not sure that the model really expands from netflows to IP flows (or TOR)
>> in the future.
>> 
>> I'm not sure the Security Considerations warn enough about re-using the same
>> credentials with different protocols/auth mechanisms. (eg TLS and IKEv2, or TLS
>> 1.2 and QUIC, or using RSA as RSA-PKCS1.5 as well as RSA-PSS)
>> 
>> Unqualified Hostname vs FQDN seems a security risk punted mostly to the
>> application.
> 
> These are new comments as part of the COMMENT block. As with the others, we will file an issue on our github and resolve them there. Personally, I think we should use these comments to strengthen our security considerations section (e.g., to warn about the security risk when not using an FQDN. Indeed such a warning does now exist in the text, and using an FQDN is qualified  with a SHOULD, but the security considerations section could point at it once again).
> 
> 
> Here comes an answer for the other COMMENT items on the basis of what happened on github:
> 
> 
>> I don't understand this code:
>> 
>>       Connection := Preconnection.Initiate()
>>       Connection2 := Connection.Clone()
>> 
>>       Connection -> Ready<>
>>       Connection2 -> Ready<>
>> 
>>       //---- Ready event handler for any Connection C begin ----
>>       C.Send(messageDataRequest)
>> 
>> Where does "C" come from in "C.Send" ? The comment says "any Connection C"?
> 
> Issue: https://github.com/ietf-tapswg/api-drafts/issues/1368
> PR to resolve: https://github.com/ietf-tapswg/api-drafts/pull/1413
> 
> We hope that the text that we added makes this clear enough: this code block is an event handler for Connection C. Either it gets C as a parameter, or it’s in some other way associated to Connection C.
> 
> 
>> I have a question on this code:
>> 
>>       Preconnections are reusable after being used to initiate a
>>       Connection, whether this Connection was closed or not. Hence, it
>>       would be correct to continue as follows after the above example:
>> 
>>       //.. carry out adjustments to the Preconnection, if desired
>>       Connection := Preconnection.Initiate()
>> 
>> What would happen here? I can imagine a "compiler" turning this into
>> a noop.  I can also see it would kill the existing Connection state and
>> start a new one. This could be to a different IP address (eg if the DNS
>> name has A and AAAA). When starting a new one, what would happen to any
>> Message or Event queues for Connection ?
> 
> Issue: https://github.com/ietf-tapswg/api-drafts/issues/1369
> PR to resolve: https://github.com/ietf-tapswg/api-drafts/issues/1369
> 
> A Preconnection is just a data structure, used as a template to create a Connection - so, the call to Initiate() after adjustments wouldn’t affect the already ongoing Connection.
> We hope that the text that we added makes this clear enough now.
> 
> 
>>       Preconnection.AddRemote(RemoteCandidates)
>> 
>> Should this not technically be:
>> 
>>       Preconnection.AddRemote([]RemoteCandidates)
>> 
>> as the array contains at least a host and a stun server candidate?
>> 
>> Maybe this is just the difference between you using the variable you define
>> that has been assigned, versus a more C like prototype format, eg:
>> 
>>       Preconnection := NewPreconnection([]LocalEndpoint,
>> 
>> So I guess if your example here had set LocalEndpoint := [a,b] you would not
>> have used [] in the call ?
> 
> Issue: https://github.com/ietf-tapswg/api-drafts/issues/1371
> Commit: https://github.com/ietf-tapswg/api-drafts/commit/e1ca6015d25c8a2a3f78f99cfc552ed4fd63019e
> 
> … this should be resolved now.
> 
> 
>> Section 6.1.4
>> 
>> Perhaps it would be useful to add a Local Endpoint with ephemeral port before
>> the Local Endpoint with static port example, as the ephemeral port should be
>> the far more common case. Right now the examples might give the wrong impression
>> a local port MUST be specified.
> 
> Yes, good catch, thanks!   - addressed:
> 
> Issue: https://github.com/ietf-tapswg/api-drafts/issues/1374
> PR: https://github.com/ietf-tapswg/api-drafts/pull/1431
> 
> 
>> SecurityParameters.Set() seems to allow to set our identiy and our certificate,
>> but not the remote peer's identity or certificate? For example, one might want
>> to pin a remote certificate and not just rely on a WithHostname() identifier
>> being present as subjectAltname on a certificate.
> 
> Issue: https://github.com/ietf-tapswg/api-drafts/issues/1375
> PR: https://github.com/ietf-tapswg/api-drafts/pull/1430
> (this PR introduces client- and server- certificates)
> 
> 
>>      The Connection state, which can be one of the following:
>>       Establishing, Established, Closing, or Closed.
>> 
>> I think the text in Section 8 should more clearly show the property names if the
>> goal is to have different implementations use the identical name. Eg in this
>> case, why not write: The Connection state ("state"). The next two entries are
>> similarly lacking a clear keyword to use:
>> 
>>       Whether the Connection can be used to send data.
>> 
>>       Whether the Connection can be used to receive data.
>> 
>> eg. why not define words for these to implementations will use the same words,
>> in this case perhaps ReadySend and ReadyRcv ?
>> Writing that now, perhaps "state" should be "State" then ?
> 
> Issue: https://github.com/ietf-tapswg/api-drafts/issues/1377
> PR: https://github.com/ietf-tapswg/api-drafts/pull/1437
> 
> This PR incorporates your suggestion by introducing three read-only properties: connState (to query for “Establishing”, “Established”, “Closing”, “Closed"), canSend, canReceive.
> 
> 
>> Section 8.1.1:
>> 
>>       If this property is an Integer
>> 
>> It is best to define the actual type in this document and not let
>> implementations choose, if the goal is to try and harmonize implementations. I
>> also see no non-integer value being given here ?
> 
> We got a similar comment about this from Lars Eggert, so we discussed both in this issue:
> https://github.com/ietf-tapswg/api-drafts/issues/1346
> 
> This is a more general thing, affecting several properties. After trying and discussing (at an interim) a somewhat heavy-handed approach to solve this for all of them:
> https://github.com/ietf-tapswg/api-drafts/pull/1409
> … we ended up with what we agreed was a better way to do it, in this PR: https://github.com/ietf-tapswg/api-drafts/pull/1410
> 
> Now it’s a non-negative Integer, with a defined special value of 0, and how to specify "Full Coverage” is explained in the text.
> 
> 
> I hope this helps - my apologies for not immediately answering how we addressed the COMMENT items !
> 
> Cheers,
> Michael
>