Updates to X.509 Policy Validation
draft-ietf-lamps-x509-policy-graph-05

Received changes through RFC Editor sync (changed state to RFC, created became rfc relationship between draft-ietf-lamps-x509-policy-graph and RFC 9618, changed IESG state to RFC Published)

[Ballot comment]
Thanks for the clear document and action.

NIT: I would probably move Section 6.5 to 6.1, as that seems to be the most efficient and simple mitigation to apply.

[Ballot comment]
I am balloting NoObj in the "this is way outside my area of expertise, but I sure do like the font you selected" sense of the term.

[Ballot comment]
Thank you for the work on this document.

Many thanks to Martin Thomson for his ART ART review: https://mailarchive.ietf.org/arch/msg/art/bskZp76k4VtHqThOqLYapIGxAxc/ and to the authors for addressing it.

[Ballot comment]
Thanks for this well-written document. I can’t say that I spent enough time with the algorithm to be able to vouch for its correctness myself, but that’s what subject matter area reviewers are for.

I sincerely hope that lamps is considering, or will consider, a bis of RFC 5280. It seems to me that the material in this document deserves to be incorporated directly into the base specification, instead of sitting in an update document that a naïve reader could accidentally miss. The same is true of some of the other updates. But this is just me editorializing, I don’t expect any changes to the present document.

I have one question, and a couple nits.

In the example associated with 5.3 (d)(2), should there be some language telling me why bronze doesn’t appear in the figure, although gold and silver do?

Nits:

- in “If either (1) the value of explicit_policy variable is greater than zero”,  it looks as though a definite article is needed there, i.e. “If either (1) the value of the explicit_policy variable is greater than zero”. (Removing the word “variable” would also make it grammatical.)

- s/ertificate/certificate/

[Ballot comment]
Thanks for this well-written document. I can’t say that I spent enough time with the algorithm to be able to vouch for its correctness myself, but that’s what subject matter area reviewers are for.

I sincerely hope that lamps is considering, or will consider, a bis of RFC 5280. It seems to me that the material in this document deserves to be incorporated directly into the base specification, instead of sitting in an update document that a naïve reader could accidentally miss. The same is true of some of the other updates. But this is just me editorializing, I don’t expect any changes to the present document.

I have one question, and a couple nits.

In the example associated with 5.3 (d)(2), should there be some language telling me why bronze doesn’t appear in the figure, although gold and silver do?

Nits:
- “If either (1) the value of explicit_policy variable is greater than zero” — it looks as though a definite article is needed there, i.e. “If either (1) the value of the explicit_policy variable is greater than zero”. (Removing the word “variable” would also make it grammatical.)
- s/ertificate/certificate/

[Ballot comment]
Hi David,

Thanks for writing this document. I'm not an expert in this area but found the description of both the problem being addressed and the overview of the solution to mitigate it to be clear and easy to understand.

Regards,
Rob

(Via drafts-lastcall@iana.org): IESG/Authors/WG Chairs:

IANA has completed its review of draft-ietf-lamps-x509-policy-graph-03, which is currently in Last Call, and has the following comments:

We understand that this document doesn't require any registry actions.

While it's often helpful for a document's IANA Considerations section to remain in place upon publication even if there are no actions, if the authors strongly prefer to remove it, we do not object.

If this assessment is not accurate, please respond as soon as possible.

For definitions of IANA review states, please see:

https://datatracker.ietf.org/help/state/draft/iana-review

Thank you,

David Dong
IANA Services Sr. Specialist

The following Last Call announcement was sent out (ends 2024-01-22):

From: The IESG
To: IETF-Announce
CC: draft-ietf-lamps-x509-policy-graph@ietf.org, housley@vigilsec.com, lamps-chairs@ietf.org, rdd@cert.org, spasm@ietf.org
Reply-To: last-call@ietf.org
Sender:
Subject: Last Call:  (Updates to X.509 Policy Validation) to Proposed Standard


The IESG has received a request from the Limited Additional Mechanisms for
PKIX and SMIME WG (lamps) to consider the following document: - 'Updates to
X.509 Policy Validation'
  as Proposed Standard

The IESG plans to make a decision in the next few weeks, and solicits final
comments on this action. Please send substantive comments to the
last-call@ietf.org mailing lists by 2024-01-22. Exceptionally, comments may
be sent to iesg@ietf.org instead. In either case, please retain the beginning
of the Subject line to allow automated sorting.

Abstract


  This document updates RFC 5280 to replace the algorithm for X.509
  policy validation with an equivalent, more efficient algorithm.  The
  original algorithm built a structure which scaled exponentially in
  the worst case, leaving implementations vulnerable to denial-of-
  service attacks.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-lamps-x509-policy-graph/


The following IPR Declarations may be related to this I-D:

  https://datatracker.ietf.org/ipr/6053/

# Shepherd Write-up for draft-ietf-lamps-x509-policy-graph-02

## 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?

  There is support in the LAMPS WG for this document.  It eliminates the
  vulnerabilities like [CVE-2023-0464] and [CVE-2023-23524].

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

  There was little controversy, and suggested improvements were readily
  accepted by the authors.

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.)

  No one has threatened an appeal; however, one concern was raised during
  WG Last Call that should be highlighted.  As written, this document is not
  stand alone.  It makes changes to the certification path validation algorithm
  in RFC 5280.  There is a concern that future updates to RFC 5280 will conflict
  with these updates.  The person that raised these concerns would prefer an
  update to RFC 5280 that completely replaces Section 6 and is written as a set
  of editing instructions to be made against Section 6 of RFC 5280.  The person
  that raised this concern was able to convince one other LAMPS WG participant,
  but the LAMPS WG Chairs determined that they were in the rough.

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 has been some code written, including at least one implementation of
  the certification path validation algorithm in RFC 5280 that was updated to
  the algorithm in this document.

## 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.

  No concerns about interaction with other technologies.

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.

  No special reviews are needed.

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]?

  This document does not include a YANG module.

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.

  No formal language is used..

## 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.

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?

    No concerns were noticed.

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?

    As reflected in the Datatracker: Proposed Standard on the IETF Stream.

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 explicitly stated that he is unaware of any IPR
    that needs to be declared.

    A third part disclosure was made: https://datatracker.ietf.org/ipr/6053/.
    However, this seems to be related to getting time from GPS, which is not
    a topic discussed in the Internet-Draft.

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.)

    IDnits offers the following complaint:

~~~
    The document seems to lack a disclaimer for pre-RFC5378 work, but may
    have content which was first submitted before 10 November 2008.  If you
    have contacted all the original authors and they are all willing to grant
    the BCP78 rights to the IETF Trust, then this is fine, and you can ignore
    this comment.  If not, you may need to add the pre-RFC5378 disclaimer.
    (See the Legal Provisions document at
    https://trustee.ietf.org/license-info for more information.)
~~~

  As an author of RFC 5280, I do not see how this concern applies to this update.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

    No concerns.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

    All references are freely available.

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 are no downward references.

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?

    All normative references are published RFCs.

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.

    No, this document will not change the status of any other document.

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]).

    No updates to any IANA registries are needed.

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.

    No new IANA registries are needed.

# Shepherd Write-up for draft-ietf-lamps-x509-policy-graph-02

## 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?

  There is support in the LAMPS WG for this document.  It eliminates the
  vulnerabilities like [CVE-2023-0464] and [CVE-2023-23524].

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

  There was little controversy, and suggested improvements were readily
  accepted by the authors.

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.)

  No one has threatened an appeal; however, one concern was raised during
  WG Last Call that should be highlighted.  As written, this document is not
  stand alone.  It makes changes to the certification path validation algorithm
  in RFC 5280.  There is a concern that future updates to RFC 5280 will conflict
  with these updates.  The person that raised these concerns would prefer an
  update to RFC 5280 that completely replaces Section 6 and is written as a set
  of editing instructions to be made against Section 6 of RFC 5280.  The person
  that raised this concern was able to convince one other LAMPS WG participant,
  but the LAMPS WG Chairs determined that they were in the rough.

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 has been some code written, including at least one implementation of
  the certification path validation algorithm in RFC 5280 that was updated to
  the algorithm in this document.

## 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.

  No concerns about interaction with other technologies.

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.

  No special reviews are needed.

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]?

  This document does not include a YANG module.

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.

  No formal language is used..

## 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.

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?

    No concerns were noticed.

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?

    As reflected in the Datatracker: Proposed Standard on the IETF Stream.

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 explicitly stated that he is unaware of any IPR
    that needs to be declared.

    A third part disclosure was made: https://datatracker.ietf.org/ipr/6053/.
    However, this seems to be related to getting time from GPS, which is not
    a topic discussed in the Internet-Draft.

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.)

    IDnits offers the following complaint:

~~~
    The document seems to lack a disclaimer for pre-RFC5378 work, but may
    have content which was first submitted before 10 November 2008.  If you
    have contacted all the original authors and they are all willing to grant
    the BCP78 rights to the IETF Trust, then this is fine, and you can ignore
    this comment.  If not, you may need to add the pre-RFC5378 disclaimer.
    (See the Legal Provisions document at
    https://trustee.ietf.org/license-info for more information.)
~~~

  As an author of RFC 5280, I do not see how this concern applies to this update.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

    No concerns.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

    All references are freely available.

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 are no downward references.

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?

    All normative references are published RFCs.

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.

    No, this document will not change the status of any other document.

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]).

    No updates to any IANA registries are needed.

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.

    No new IANA registries are needed.

# Shepherd Write-up for draft-ietf-lamps-x509-policy-graph-02

## 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?

  There is support in the LAMPS WG for this document.  It eliminates the
  vulnerabilities like [CVE-2023-0464] and [CVE-2023-23524].

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

  There was little controversy, and suggested improvements were readily
  accepted by the authors.

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.)

  No one has threatened an appeal; however, one concern was raised during
  WG Last Call that should be highlighted.  As written, this document is not
  stand alone.  It makes changes to the certification path validation algorithm
  in RFC 5280.  There is a concern that future updates to RFC 5280 will conflict
  with these updates.  The peron raising these concerns would prefer an update
  to RFC 5280 that completely replaces Section 6.  The person that raised this
  concern was able to convince one other LAMPS WG participant, but the LAMPS WG
  Chairs determined that they were in the rough.

Would future changes to this document do a cut and paste to this document or to RFC5280?  Once you've accepted that cut and paste is a thing, why wouldn't you accept it downstream?  How many levels are acceptable?  How do you deal with dueling cut and pastes?

In any event, this isn't a technical argument, and it might be useful to have a discussion with the RSCE and the RPC on RFC style.

Please include my objections in the write up you send to the ADs and IESG.  Happy to write a paragraph if you need a summary.

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 has been some code written, including at least one implementation of
  the certification path validation algorithm in RFC 5280 that was updated to
  the algorithm in this document.

## 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.

  No concerns about interaction with other technologies.

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.

  No special reviews are needed.

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]?

  This document does not include a YANG module.

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.

  No formal language is used..

## 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.

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?

    No concerns were noticed.

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?

    As reflected in the Datatracker: Proposed Standard on the IETF Stream.

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 explicitly stated that he is unaware of any IPR
    that needs to be declared.

    A third part disclosure was made: https://datatracker.ietf.org/ipr/6053/.
    However, this seems to be related to getting time from GPS, which is not
    a topic discussed in the Internet-Draft.

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.)

    IDnits offers the following complaint:

~~~
    The document seems to lack a disclaimer for pre-RFC5378 work, but may
    have content which was first submitted before 10 November 2008.  If you
    have contacted all the original authors and they are all willing to grant
    the BCP78 rights to the IETF Trust, then this is fine, and you can ignore
    this comment.  If not, you may need to add the pre-RFC5378 disclaimer.
    (See the Legal Provisions document at
    https://trustee.ietf.org/license-info for more information.)
~~~

  As an author of RFC 5280, I do not see how this concern applies to this update.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

    No concerns.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

    All references are freely available.

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 are no downward references.

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?

    All normative references are published RFCs.

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.

    No, this document will not change the status of any other document.

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]).

    No updates to any IANA registries are needed.

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.

    No new IANA registries are needed.

# Shepherd Write-up for draft-ietf-lamps-x509-policy-graph-02

## 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?

  There is support in the LAMPS WG for this document.  It eliminates the
  vulnerabilities like [CVE-2023-0464] and [CVE-2023-23524].

2. Was there controversy about particular points, or were there decisions where
  the consensus was particularly rough?

  There was little controversy, and suggested improvements were readily
  accepted by the authors.

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.)

  No one has threatened an appeal.

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 has been some code written, including at least one implementation of
  the certification path validation algorithm in RFC 5280 that was updated to
  the algorithm in this document.

## 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.

  No concerns about interaction with other technologies.

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.

  No special reviews are needed.

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]?

  This document does not include a YANG module.

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.

  No formal language is used..

## 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.

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?

    No concerns were noticed.

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?

    As reflected in the Datatracker: Proposed Standard on the IETF Stream.

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 explicitly stated that he is unaware of any IPR
    that needs to be declared.

    A third part disclosure was made: https://datatracker.ietf.org/ipr/6053/.
    However, this seems to be related to getting time from GPS, which is not
    a topic discussed in the Internet-Draft.

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.)

    IDnits offers the following complaint:

~~~
    The document seems to lack a disclaimer for pre-RFC5378 work, but may
    have content which was first submitted before 10 November 2008.  If you
    have contacted all the original authors and they are all willing to grant
    the BCP78 rights to the IETF Trust, then this is fine, and you can ignore
    this comment.  If not, you may need to add the pre-RFC5378 disclaimer.
    (See the Legal Provisions document at
    https://trustee.ietf.org/license-info for more information.)
~~~

  As an author of RFC 5280, I do not see how this concern applies to this update.

15. Should any informative references be normative or vice-versa? See the [IESG
    Statement on Normative and Informative References][16].

    No concerns.

16. List any normative references that are not freely available to anyone. Did
    the community have sufficient access to review any such normative
    references?

    All references are freely available.

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 are no downward references.

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?

    All normative references are published RFCs.

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.

    No, this document will not change the status of any other document.

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]).

    No updates to any IANA registries are needed.

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.

    No new IANA registries are needed.