Subject: Re: [Gen-art] Genart last call review of draft-ietf-core-object-security-08
From: Göran Selander <[email-masked]>
To: Joel Halpern <[email-masked]>, "[email-masked]" <[email-masked]>
Cc: "[email-masked]" <[email-masked]>, "[email-masked]" <[email-masked]>, "[email-masked]" <[email-masked]>
Date: Fri, 23 Feb 2018 10:26:09 +0000
List-Id: "GEN-ART: General Area Review Team" <gen-art.ietf.org>

Hi Joel,

Thanks for your review. Comments inline.

On 2018-02-22 04:51, "Joel Halpern" <[email-masked]> wrote:

>Reviewer: Joel Halpern
>Review result: Ready with Nits
>
>I am the assigned Gen-ART reviewer for this draft. The General Area
>Review Team (Gen-ART) reviews all IETF documents being processed
>by the IESG for the IETF Chair.  Please treat these comments just
>like any other last call comments.
>
>For more information, please see the FAQ at
>
><https://trac.ietf.org/trac/gen/wiki/GenArtfaq>.
>
>Document: draft-ietf-core-object-security-08
>Reviewer: Joel Halpern
>Review Date: 2018-02-21
>IETF LC End Date: 2018-03-02
>IESG Telechat date: 2018-03-08
>
>Summary: This document is ready for publication as a Proposed Standard RFC
>
>Major issues: N/A
>
>Minor issues:
>    In section 8.2 on verifying the request, step 5 says to "compose" the
>    Additional Authentication Data.  I would have expected it to be
>"verify"
>    the Additional Authentication Data.  I could imagine that the
>verification
>    consists of composing what it should be, and then comparing with what
>is
>    received.  But I do not see the comparison step.  is it implicit in
>some
>    other step?  This occurs again in 8.4, so I presume I am simply
>missing
>    something.  This may suggest some clarification could be useful.

The AAD is indeed “composed" both on encrypting and decrypting side from
data which needs to be known to the endpoint at the time when the AEAD
operation is performed. The authenticated decryption process is described
in:

https://tools.ietf.org/html/rfc5116#section-2.2

So the verification consists of feeding the input, including the AAD, to
the authenticated decryption which calculates the plain text or FAIL, and
a failure may be - but is not necessarily - caused by wrong AAD.

The AD review also indicated that we should move the reference to RFC 5116
to an early section in the draft and that change is already included in
the latest version on the CoRE WG Github.

Best regards
Göran