# Document Shepherd Write-Up for Group Documents
*This version is dated 4 July 2022.*
Thank you for your service as a document shepherd. Among the responsibilities is
answering the questions in this write-up to give helpful context to Last Call
and Internet Engineering Steering Group ([IESG][1]) reviewers, and your
diligence in completing it is appreciated. The full role of the shepherd is
further described in [RFC 4858][2]. You will need the cooperation of the authors
and editors to complete these checks.
Note that some numbered items contain multiple related questions; please be sure
to answer all of them.
## Document History
1. Does the working group (WG) consensus represent the strong concurrence of a
few individuals, with others being silent, or did it reach broad agreement?
The consensus for this document is broad and solid. Multiple active WG
participants voiced support during WGLC. No objections were raised during
WGLC. There was clear consensus, existing deployments and no objections.
2. Was there controversy about particular points, or were there decisions where
the consensus was particularly rough?
The WG discussed applicability and use-cases for chunked OHTTP early on,
given that chunking changes the security and privacy properties of OHTTP
while not providing the guarantees of a proxied TLS connection.
Specifically, there were concerns about the lack of forward secrecy and
replay protection as well as how interactivity introduced by chunking
potentially enables timing attacks. The authors addressed these concerns by
adding an [Applicability
section](https://datatracker.ietf.org/doc/html/draft-ietf-ohai-chunked-ohttp-06#name-applicability)
and adding text on
[interactivity](https://datatracker.ietf.org/doc/html/draft-ietf-ohai-chunked-ohttp-06#name-interactivity-and-privacy),
[forward
secrecy](https://datatracker.ietf.org/doc/html/draft-ietf-ohai-chunked-ohttp-06#section-7)
and [replay attack
risk](https://datatracker.ietf.org/doc/html/draft-ietf-ohai-chunked-ohttp-06#name-message-truncation).
There was also discussion of the [incremental nature of
HTTP](https://github.com/ietf-wg-ohai/draft-ohai-chunked-ohttp/issues/19),
motivating use of an HTTP "Incremental" header to get incremental
forwarding. The draft now references the ["Incremental" HTTP header
field](https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-incremental-00)
draft which has been adopted by the HTTP WG.
3. Has anyone threatened an appeal or otherwise indicated extreme discontent? If
so, please summarize the areas of conflict in separate email messages to the
responsible Area Director. (It should be in a separate email because this
questionnaire is publicly available.)
None indicated on the list; no threats of appeal recorded. As mentioned
above, there were initial concerns about the privacy impact and use-cases
for chunked OHTTP but they were resolved through discussion during meetings
and [issue
discussion](https://github.com/ietf-wg-ohai/draft-ohai-chunked-ohttp/issues?q=is%3Aissue%20state%3Aclosed).
WGLC feedback was supportive.
4. For protocol documents, are there existing implementations of the contents of
the document? Have a significant number of potential implementers indicated
plans to implement? Are any existing implementations reported somewhere,
either in the document itself (as [RFC 7942][3] recommends) or elsewhere
(where)?
There are several existing deployments and implementations of Chunked OHTTP.
[Cloudflare
reported](https://mailarchive.ietf.org/arch/msg/ohai/xygArMZVfrSDtYvINHhYZHSGK1Q/)
deployed implementations of both gateway and relay. [Apple
also](https://datatracker.ietf.org/doc/minutes-120-ohai-202407260130/) has
deployments of Chunked OHTTP for Private Cloud Compute and related AI
features. There is an implementation by Microsoft for their [attested OHTTP
server](https://github.com/microsoft/attested-ohttp-server). Google's QUICHE
has support for [chunked
OHTTP](https://quiche.googlesource.com/quiche.git/%2B/d71d77ba2b251b5b3fa049e8475c62ba1d473157).
## Additional Reviews
5. Do the contents of this document closely interact with technologies in other
IETF working groups or external organizations, and would it therefore benefit
from their review? Have those reviews occurred? If yes, describe which
reviews took place.
The document interacts with HTTP and has new Media Types. Authors requested
a [media-types
review](https://mailarchive.ietf.org/arch/msg/media-types/voY6mqv9c5LQGM2odHIoqFlUbuU/)
for two new media types. The "Incremental HTTP Messages" work is being done
in HTTP WG and is cited as a normative reference. The chairs also sent a
pointer to the Chunked OHTTP draft's last call to the HTTP WG mailing list;
there's a large overlap in the people involved between the two groups.
6. Describe how the document meets any required formal expert review criteria,
such as the MIB Doctor, YANG Doctor, media type, and URI type reviews.
Media-type review requested for message/ohttp-chunked-req and
message/ohttp-chunked-res. No other formal expert reviews (MIB/YANG/URI) are
applicable.
7. If the document contains a YANG module, has the final version of the module
been checked with any of the [recommended validation tools][4] for syntax and
formatting validation? If there are any resulting errors or warnings, what is
the justification for not fixing them at this time? Does the YANG module
comply with the Network Management Datastore Architecture (NMDA) as specified
in [RFC 8342][5]?
N/A
8. Describe reviews and automated checks performed to validate sections of the
final version of the document written in a formal language, such as XML code,
BNF rules, MIB definitions, CBOR's CDDL, etc.
N/A
## Document Shepherd Checks
9. Based on the shepherd's review of the document, is it their opinion that this
document is needed, clearly written, complete, correctly designed, and ready
to be handed off to the responsible Area Director?
Yes. The draft is clearly needed and is deployed and already being used by
millions of users. The text is clear and complete.
10. Several IETF Areas have assembled [lists of common issues that their
reviewers encounter][6]. For which areas have such issues been identified
and addressed? For which does this still need to happen in subsequent
reviews?
Chunked OHTTP interacts with the Security and HTTP areas. There have been
extensive discussions about both, as mentioned above, primarily because
there is large overlap between the participants. Formal SECDIR and HTTPDIR
review should still occur.
11. What type of RFC publication is being requested on the IETF stream ([Best
Current Practice][12], [Proposed Standard, Internet Standard][13],
[Informational, Experimental or Historic][14])? Why is this the proper type
of RFC? Do all Datatracker state attributes correctly reflect this intent?
Proposed Standard, because it involves multiple parties (client, relay,
gateway) implementing a commonly-understood protocol. Yes, the datatracker
reflects that intent.
12. Have reasonable efforts been made to remind all authors of the intellectual
property rights (IPR) disclosure obligations described in [BCP 79][7]? To
the best of your knowledge, have all required disclosures been filed? If
not, explain why. If yes, summarize any relevant discussion, including links
to publicly-available messages when applicable.
The authors have confirmed that no IPR exists to their knowledge.
13. Has each author, editor, and contributor shown their willingness to be
listed as such? If the total number of authors and editors on the front page
is greater than five, please provide a justification.
Yes.
14. Document any remaining I-D nits in this document. Simply running the [idnits
tool][8] is not enough; please review the ["Content Guidelines" on
authors.ietf.org][15]. (Also note that the current idnits tool generates
some incorrect warnings; a rewrite is underway.)
There is a normative reference to an in-progress CFRG draft,
[draft-irtf-cfrg-aead-limits-10](https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-aead-limits-10).
This document is in Research Group Last Call, and is expected to proceed
soon.
There is also a downref to a CFRG document, RFC 9180 (HPKE), but this RFC
is listed in the [DOWNREF
registry](https://datatracker.ietf.org/doc/downref/).
There is 1 warning for "non-ascii characters in the document", and line 584
appears to be too long. These are minor formatting issues which are pending
a draft update.
15. Should any informative references be normative or vice-versa? See the [IESG
Statement on Normative and Informative References][16].
No.
16. List any normative references that are not freely available to anyone. Did
the community have sufficient access to review any such normative
references?
None.
17. Are there any normative downward references (see [RFC 3967][9] and [BCP
97][10]) that are not already listed in the [DOWNREF registry][17]? If so,
list them.
There is a normative reference to an in-progress CFRG draft,
[draft-irtf-cfrg-aead-limits-10](https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-aead-limits-10).
This document is in Research Group Last Call, and is expected to progress
soon.
RFC 9180 is listed in the DOWNREF registry.
18. Are there normative references to documents that are not ready to be
submitted to the IESG for publication or are otherwise in an unclear state?
If so, what is the plan for their completion?
The draft references the [Incremental HTTP header
field](https://datatracker.ietf.org/doc/html/draft-ietf-httpbis-incremental-00).
There are no pending issues for this draft and it is expected to progress
soon. There is also a normative reference to an in-progress CFRG draft,
[draft-irtf-cfrg-aead-limits-10](https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-aead-limits-10).
This document is in Research Group Last Call, and is expected to progress
soon.
19. Will publication of this document change the status of any existing RFCs? If
so, does the Datatracker metadata correctly reflect this and are those RFCs
listed on the title page, in the abstract, and discussed in the
introduction? If not, explain why and point to the part of the document
where the relationship of this document to these other RFCs is discussed.
None. The draft does not obsolete, update, or down-grade any RFCs.
20. Describe the document shepherd's review of the IANA considerations section,
especially with regard to its consistency with the body of the document.
Confirm that all aspects of the document requiring IANA assignments are
associated with the appropriate reservations in IANA registries. Confirm
that any referenced IANA registries have been clearly identified. Confirm
that each newly created IANA registry specifies its initial contents,
allocations procedures, and a reasonable name (see [RFC 8126][11]).
The IANA considerations section looks accurate.
21. List any new IANA registries that require Designated Expert Review for
future allocations. Are the instructions to the Designated Expert clear?
Please include suggestions of designated experts, if appropriate.
N/A
[1]: https://www.ietf.org/about/groups/iesg/
[2]: https://www.rfc-editor.org/rfc/rfc4858.html
[3]: https://www.rfc-editor.org/rfc/rfc7942.html
[4]: https://wiki.ietf.org/group/ops/yang-review-tools
[5]: https://www.rfc-editor.org/rfc/rfc8342.html
[6]: https://wiki.ietf.org/group/iesg/ExpertTopics
[7]: https://www.rfc-editor.org/info/bcp79
[8]: https://www.ietf.org/tools/idnits/
[9]: https://www.rfc-editor.org/rfc/rfc3967.html
[10]: https://www.rfc-editor.org/info/bcp97
[11]: https://www.rfc-editor.org/rfc/rfc8126.html
[12]: https://www.rfc-editor.org/rfc/rfc2026.html#section-5
[13]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.1
[14]: https://www.rfc-editor.org/rfc/rfc2026.html#section-4.2
[15]: https://authors.ietf.org/en/content-guidelines-overview
[16]:
https://www.ietf.org/about/groups/iesg/statements/normative-informative-references/
[17]: https://datatracker.ietf.org/doc/downref/