Re: [Rats] Fwd: New Version Notification for draft-birkholz-rats-reference-interaction-model-03.txt

[Anders Rundgren <[e-mail]>]

On 2020-07-08 14:24, Henk Birkholz wrote:
> Hi Anders,

Hi Henk,

> 
> thanks for your reach-out :) As far as I know, session-based creation of
> evidence is map-able to every kind of interaction model. I'll quickly
> illustrate how I think that typically works. Please step in, if I am
> erring here.
> 
> Session-based remote attestation "bundles" a certain amount of
> "evidence-generating primitive operations" of an Attesting Environment
> in a way that corresponding results are packaged in relative large set
> of Claims collected over time - in one piece of evidence.

It is possible that you can characterize session-based remote attestations
like that but at least in my case the goal is different because it is only
about creating a secure session with an entity that has an attested quality.
The protected API is subsequently used for executing arbitrary secure
operations that for some reasons must be performed in a specific sequence.

This is pretty much a carbon copy of smart card provisioning where a session
is created based on an embedded key which indirectly provides attestation
(the card must be known).  The difference is that session-based remote
attestation does not presume a explicit knowledge of each trusted container.
The rollback feature is another enhancement.

It's not a big deal w.r.t. to the I-D, but it might be worth knowing anyway :)

Regards,
Anders

> 
> Some solutions call these bundles audit sessions. If these bundles
> constitute evidence that can represent past states, some solutions call
> the resulting evidence secure audit logs.
> 
> Looking at the referenced write-up [1], the audit approach seems to be
> combined with a roll-back feature. That is an implementation feature for
> remediation that is typically not directly in-scope of RATS. But - RATS
> of course play a vital role in assessing the need for & and the result
> of remediation procedures, as well as selecting appropriate remediation
> procedures in the first place (see TEEP).
> 
> In summary, my early feedback is that the illustrated Protected API can
> be mapped to all three interaction model - it was probably designed with
> CHARRA in mind. Maybe it is useful to note here that a subscription
> session is not the same thing as an audit session.
> 
> 
> Viele Grüße,
> 
> Henk
> 
> On 08.07.20 13:17, Anders Rundgren wrote:
>> On 2020-07-08 08:52, Henk Birkholz wrote:
>>> Hi list,
>>
>> Hi Henk,
>>
>>>
>>> this version of the reference interaction models I-D now includes the
>>> three main models that are used across several related documents:
>>>
>>> * challenge/response remote attestation (charra)
>>> * uni-directional remote attestation, and
>>> * streaming remote attestation
>>
>> This is great but I don't see that the session-based attestation
>> concept[1] used in Saturn[2,3], is covered by this I-D.
>>
>> Best regards,
>> Anders
>>
>> 1]
>> https://cyberphone.github.io/doc/research/session-based-remote-attestation.pdf
>>
>>
>> 2] https://cyberphone.github.io/openbankingwallet
>> 3] https://cyberphone.github.io/doc/security/keygen2.html
>>
>>>
>>> New diagrams for all three interaction models can be found in section 8:
>>>
>>>> https://datatracker.ietf.org/doc/html/draft-birkholz-rats-reference-interaction-model#section-8
>>>>
>>>
>>> As an attester's identity is vital to all interaction models in RATS --
>>> but also has severe implications -- we welcome Liqun and Chris as
>>> co-authors. They are experts for direct anonymous attestation (DAA) and
>>> remote attestation in general.
>>>
>>> An overview about DAA can be found in section 5:
>>>
>>>> https://datatracker.ietf.org/doc/html/draft-birkholz-rats-reference-interaction-model#section-5
>>>>
>>>
>>>
>>> Viele Grüße,
>>>
>>> Henk
>>>
>>>
>>> -------- Forwarded Message --------
>>> Subject: New Version Notification for
>>> draft-birkholz-rats-reference-interaction-model-03.txt
>>> Date: Tue, 7 Jul 2020 23:41:20 -0700
>>> From: [e-mail]
>>> To: Liqun Chen <[e-mail]>, Michael Eckel
>>> <[e-mail]>, Christopher Newton
>>> <[e-mail]>, Henk Birkholz <[e-mail]>
>>>
>>>
>>> A new version of I-D,
>>> draft-birkholz-rats-reference-interaction-model-03.txt
>>> has been successfully submitted by Henk Birkholz and posted to the
>>> IETF repository.
>>>
>>> Name:        draft-birkholz-rats-reference-interaction-model
>>> Revision:    03
>>> Title:        Reference Interaction Models for Remote Attestation
>>> Procedures
>>> Document date:    2020-07-08
>>> Group:        Individual Submission
>>> Pages:        22
>>> URL:
>>> https://www.ietf.org/internet-drafts/draft-birkholz-rats-reference-interaction-model-03.txt
>>>
>>> Status:
>>> https://datatracker.ietf.org/doc/draft-birkholz-rats-reference-interaction-model/
>>>
>>> Htmlized:
>>> https://tools.ietf.org/html/draft-birkholz-rats-reference-interaction-model-03
>>>
>>> Htmlized:
>>> https://datatracker.ietf.org/doc/html/draft-birkholz-rats-reference-interaction-model
>>>
>>> Diff:
>>> https://www.ietf.org/rfcdiff?url2=draft-birkholz-rats-reference-interaction-model-03
>>>
>>>
>>> Abstract:
>>>       This document describes interaction models for remote attestation
>>>       procedures (RATS).  Three conveying mechanisms - Challenge/Response,
>>>       Uni-Directional, and Streaming Remote Attestation - are illustrated
>>>       and defined.  Analogously, a general overview about the information
>>>       elements typically used by corresponding conveyance protocols are
>>>       highlighted.  Privacy preserving conveyance of Evidence via Direct
>>>       Anonymous Attestation is elaborated on for each interaction model,
>>>       individually.
>>>
>>>
>>>
>>> Please note that it may take a couple of minutes from the time of
>>> submission
>>> until the htmlized version and diff are available at tools.ietf.org.
>>>
>>> The IETF Secretariat
>>>
>>>
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>>> https://www.ietf.org/mailman/listinfo/rats
>>>
>>