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Cryptographic Algorithms for the TCP Authentication Option (TCP-AO)
RFC 5926

Revision differences

Document history

Date Rev. By Action
2021-01-29
03 (System) Received changes through RFC Editor sync (added Errata tag)
2020-07-29
03 (System) Received changes through RFC Editor sync (removed Errata tag (all errata rejected))
2018-02-28
03 (System) Received changes through RFC Editor sync (added Errata tag)
2015-10-14
03 (System) Notify list changed from tcpm-chairs@ietf.org, draft-ietf-tcpm-tcp-ao-crypto@ietf.org to (None)
2012-08-22
03 (System) post-migration administrative database adjustment to the No Objection position for Pasi Eronen
2010-06-21
03 Cindy Morgan [Note]: 'RFC 5926' added by Cindy Morgan
2010-06-21
03 Cindy Morgan State Changes to RFC Published from RFC Ed Queue by Cindy Morgan
2010-06-21
03 (System) RFC published
2010-04-16
03 (System) IANA Action state changed to RFC-Ed-Ack from Waiting on RFC Editor
2010-04-16
03 (System) IANA Action state changed to Waiting on RFC Editor from In Progress
2010-04-16
03 (System) IANA Action state changed to In Progress from Waiting on Authors
2010-03-30
03 (System) IANA Action state changed to Waiting on Authors from In Progress
2010-03-25
03 Cindy Morgan State Changes to RFC Ed Queue from Approved-announcement sent by Cindy Morgan
2010-03-25
03 (System) IANA Action state changed to In Progress
2010-03-24
03 Cindy Morgan IESG state changed to Approved-announcement sent
2010-03-24
03 Cindy Morgan IESG has approved the document
2010-03-24
03 Cindy Morgan Closed "Approve" ballot
2010-03-24
03 Pasi Eronen [Ballot Position Update] Position for Pasi Eronen has been changed to No Objection from Discuss by Pasi Eronen
2010-03-24
03 Pasi Eronen [Ballot comment]
2010-03-24
03 Pasi Eronen
[Ballot discuss]
I have reviewed draft-ietf-tcpm-tcp-ao-crypto-02, and have couple of
small concerns that I'd like to discuss before recommending approval
of the document:

- …
[Ballot discuss]
I have reviewed draft-ietf-tcpm-tcp-ao-crypto-02, and have couple of
small concerns that I'd like to discuss before recommending approval
of the document:

- In other contexts where manually configured pre-shared keys are
used, it has been found useful to specify some minimum requirements
for management interfaces -- i.e. how the human-readable/entered input
is converted to the octet string. For example, here's what
draft-ietf-bfd-base said about this:

  For interoperability, the management interface by which the
  password is configured MUST accept ASCII strings, and SHOULD also
  allow for the configuration of any arbitrary binary string in
  hexadecimal form.  Other configuration methods MAY be supported.

Something similar would be needed here, IMHO (and BTW, I don't think
mandating support for UTF-8 or SASLprep is needed in this context).

- It looks like many of the informative references need to be normative.
At the very least, RFC 4493 (or NIST-SP800-38B, depending on which you
prefer) and RFC 2104; and normative references to AES (FIPS 197) and
SHA-1 (FIPS 180-3) are needed, too.

- Section 3.1.1, "based on PRF-HMAC-SHA1 [RFC2404]": the pointer to
RFC2404 here doesn't sound quite right (2404 doesn't define any PRFs;
it's just one protocol that happens to use HMAC-SHA1). Perhaps just
"based on HMAC-SHA1 [RFC2104][180-3]" would be sufficient? (also
applies to pointers in 2.2, 3.1.1.1, and 3.2)

- Section 3.1.1, "based on AES-CMAC-PRF-128 [RFC4615]": This is also
confusing, since the PRF in RFC 4615 uses a very different
construction. Perhaps just "based on AES-CMAC [800-38B][FIPS197]"?
(also applies to pointer in 3.1.1.2 )

- Section 3.1.1: "not an even multiple of the output size" initially
confused me (why an odd multiple is not allowed?). "exact multiple",
perhaps?
2010-03-24
03 (System) Sub state has been changed to AD Follow up from New Id Needed
2010-03-24
03 (System) New version available: draft-ietf-tcpm-tcp-ao-crypto-03.txt
2010-03-15
03 Samuel Weiler Request for Last Call review by SECDIR Completed. Reviewer: Magnus Nystrom.
2010-03-12
03 (System) Removed from agenda for telechat - 2010-03-11
2010-03-11
03 Cindy Morgan State Changes to IESG Evaluation::Revised ID Needed from IESG Evaluation by Cindy Morgan
2010-03-11
03 Lisa Dusseault [Ballot Position Update] New position, No Objection, has been recorded by Lisa Dusseault
2010-03-11
03 Jari Arkko [Ballot comment]
Its not traditional for the authors to thank themselves in the
acknowledgments section.
2010-03-11
03 Jari Arkko [Ballot Position Update] New position, No Objection, has been recorded by Jari Arkko
2010-03-11
03 Dan Romascanu [Ballot Position Update] New position, No Objection, has been recorded by Dan Romascanu
2010-03-11
03 Adrian Farrel [Ballot Position Update] New position, No Objection, has been recorded by Adrian Farrel
2010-03-11
03 Alexey Melnikov
[Ballot comment]
Agreeing with Pasi's DISCUSS on management interface for keys.


3.1.1.  Concrete KDFs

      - "||":      For any X || …
[Ballot comment]
Agreeing with Pasi's DISCUSS on management interface for keys.


3.1.1.  Concrete KDFs

      - "||":      For any X || Y, "||" represents a concatonation

"concatenation"?

                  operation of the binary strings X and Y.

      - Output_Length:  The length in bits of the key that the KDF will
                  produce.  The Output_length is represented within two
                  octets.  This length must be the size required for
                  the MAC algorithm that will use the PRF result as a
                  seed.

I assume this is in network byte order? It would be better to state this explicitly.
2010-03-11
03 Tim Polk [Ballot Position Update] New position, No Objection, has been recorded by Tim Polk
2010-03-10
03 Ross Callon [Ballot Position Update] New position, No Objection, has been recorded by Ross Callon
2010-03-10
03 Cullen Jennings [Ballot Position Update] New position, No Objection, has been recorded by Cullen Jennings
2010-03-10
03 Pasi Eronen [Ballot comment]
Idnits finds some missing/erronous references (which really ought to
have been fixed before sending this to IETF last call...)
2010-03-10
03 Pasi Eronen
[Ballot discuss]
I have reviewed draft-ietf-tcpm-tcp-ao-crypto-02, and have couple of
small concerns that I'd like to discuss before recommending approval
of the document:

- …
[Ballot discuss]
I have reviewed draft-ietf-tcpm-tcp-ao-crypto-02, and have couple of
small concerns that I'd like to discuss before recommending approval
of the document:

- In other contexts where manually configured pre-shared keys are
used, it has been found useful to specify some minimum requirements
for management interfaces -- i.e. how the human-readable/entered input
is converted to the octet string. For example, here's what
draft-ietf-bfd-base said about this:

  For interoperability, the management interface by which the
  password is configured MUST accept ASCII strings, and SHOULD also
  allow for the configuration of any arbitrary binary string in
  hexadecimal form.  Other configuration methods MAY be supported.

Something similar would be needed here, IMHO (and BTW, I don't think
mandating support for UTF-8 or SASLprep is needed in this context).

- It looks like many of the informative references need to be normative.
At the very least, RFC 4493 (or NIST-SP800-38B, depending on which you
prefer) and RFC 2104; and normative references to AES (FIPS 197) and
SHA-1 (FIPS 180-3) are needed, too.

- Section 3.1.1, "based on PRF-HMAC-SHA1 [RFC2404]": the pointer to
RFC2404 here doesn't sound quite right (2404 doesn't define any PRFs;
it's just one protocol that happens to use HMAC-SHA1). Perhaps just
"based on HMAC-SHA1 [RFC2104][180-3]" would be sufficient? (also
applies to pointers in 2.2, 3.1.1.1, and 3.2)

- Section 3.1.1, "based on AES-CMAC-PRF-128 [RFC4615]": This is also
confusing, since the PRF in RFC 4615 uses a very different
construction. Perhaps just "based on AES-CMAC [800-38B][FIPS197]"?
(also applies to pointer in 3.1.1.2 )

- Section 3.1.1: "not an even multiple of the output size" initially
confused me (why an odd multiple is not allowed?). "exact multiple",
perhaps?
2010-03-10
03 Pasi Eronen [Ballot Position Update] New position, Discuss, has been recorded by Pasi Eronen
2010-03-10
03 Russ Housley
[Ballot comment]
The Gen-ART Review by Avshalom Houri on 2010-03-09 includes some
  editorial comments.  Please consider them if an update to this
  document …
[Ballot comment]
The Gen-ART Review by Avshalom Houri on 2010-03-09 includes some
  editorial comments.  Please consider them if an update to this
  document is needed for any reason.
2010-03-10
03 Russ Housley [Ballot Position Update] New position, No Objection, has been recorded by Russ Housley
2010-03-10
03 Robert Sparks [Ballot Position Update] New position, No Objection, has been recorded by Robert Sparks
2010-03-10
03 Ralph Droms [Ballot Position Update] New position, No Objection, has been recorded by Ralph Droms
2010-03-10
03 Magnus Westerlund [Ballot Position Update] New position, No Objection, has been recorded by Magnus Westerlund
2010-03-10
03 Lars Eggert State Changes to IESG Evaluation from Waiting for AD Go-Ahead by Lars Eggert
2010-03-10
03 (System) State has been changed to Waiting for AD Go-Ahead from In Last Call by system
2010-03-09
03 Amanda Baber
IANA comments:

QUESTION: The registration procedures for this registry are being
described as "RFC Publication after Expert Review." When should the
expert review take place? …
IANA comments:

QUESTION: The registration procedures for this registry are being
described as "RFC Publication after Expert Review." When should the
expert review take place? During Evaluation? After approval but before
publication? Can this be stated more clearly in this document?

As a side note, we are working on a document that more clearly defines
the procedures for an Expert Review taking place during Last Call and
other stages leading to RFC Publication.

Upon approval of this document, IANA will create the following
registry at http://www.iana.org/assignments/TBD

Registry Name: Cryptographic Algorithms for TCP-AO
Registration Procedure: RFC Publication after Expert Review
Initial contents of this registry will be:

Algorithm | Reference
-----------------|----------
SHA1 | [RFC-tcpm-tcp-ao-crypto-02]
AES | [RFC-tcpm-tcp-ao-crypto-02]

We understand the above to be the only IANA Actions for this document.
2010-03-06
03 Alexey Melnikov
[Ballot comment]
3.1.1.  Concrete KDFs

      - "||":      For any X || Y, "||" represents a concatonation

"concatenation"?

      …
[Ballot comment]
3.1.1.  Concrete KDFs

      - "||":      For any X || Y, "||" represents a concatonation

"concatenation"?

                  operation of the binary strings X and Y.

      - Output_Length:  The length in bits of the key that the KDF will
                  produce.  The Output_length is represented within two
                  octets.  This length must be the size required for
                  the MAC algorithm that will use the PRF result as a
                  seed.

I assume this is in network byte order? It would be better to state this explicitly.
2010-03-06
03 Alexey Melnikov [Ballot Position Update] New position, No Objection, has been recorded by Alexey Melnikov
2010-03-02
03 Ron Bonica [Ballot Position Update] New position, Recuse, has been recorded by Ron Bonica
2010-02-25
03 Samuel Weiler Request for Last Call review by SECDIR is assigned to Magnus Nystrom
2010-02-25
03 Samuel Weiler Request for Last Call review by SECDIR is assigned to Magnus Nystrom
2010-02-24
03 Cindy Morgan Last call sent
2010-02-24
03 Cindy Morgan State Changes to In Last Call from Last Call Requested by Cindy Morgan
2010-02-24
03 Lars Eggert Placed on agenda for telechat - 2010-03-11 by Lars Eggert
2010-02-24
03 Lars Eggert [Ballot Position Update] New position, Yes, has been recorded for Lars Eggert
2010-02-24
03 Lars Eggert Ballot has been issued by Lars Eggert
2010-02-24
03 Lars Eggert Created "Approve" ballot
2010-02-24
03 Lars Eggert State Changes to Last Call Requested from AD Evaluation by Lars Eggert
2010-02-24
03 Lars Eggert Last Call was requested by Lars Eggert
2010-02-24
03 (System) Ballot writeup text was added
2010-02-24
03 (System) Last call text was added
2010-02-24
03 (System) Ballot approval text was added
2010-02-24
03 Lars Eggert State Changes to AD Evaluation from Publication Requested by Lars Eggert
2010-02-24
03 Lars Eggert [Note]: 'Wesley Eddy (Wesley.M.Eddy@nasa.gov) is the document shepherd.' added by Lars Eggert
2010-02-22
03 Amy Vezza
draft-ietf-tcpm-tcp-ao-crypto-02
 


  (1.a) Who is the Document Shepherd for this document? Has the
        Document Shepherd personally reviewed this version of …
draft-ietf-tcpm-tcp-ao-crypto-02
 


  (1.a) Who is the Document Shepherd for this document? Has the
        Document Shepherd personally reviewed this version of the
        document and, in particular, does he or she believe this
        version is ready for forwarding to the IESG for publication?


Wesley Eddy (Wesley.M.Eddy@nasa.gov) is the document shepherd.  He
has personally reviewed this version and believes it is ready for
forwarding to the IESG for publication.



  (1.b) Has the document had adequate review both from key WG members
        and from key non-WG members? Does the Document Shepherd have
        any concerns about the depth or breadth of the reviews that
        have been performed? 


The document has had review in the TCPM working group, as well as
explicit participlation from the IETF Security Area.  The document
has been split out of the base TCP AO specification in order to
allow the recommended crypto algorithms to evolve over time
decoupled from the protocol specification.  TCPM reviews have
focused more on the protocol itself, whereas the security area
has been looked to for particulars in this portion of the work.



  (1.c) Does the Document Shepherd have concerns that the document
        needs more review from a particular or broader perspective,
        e.g., security, operational complexity, someone familiar with
        AAA, internationalization or XML?


There are no concerns in this regard that the document shepherd has;
the security experts have been involved from the outset, and the
operational requirements have been considered and brought up from
that time too, given that the primary forseen users of this technology
are BGP and LDP deployments.



  (1.d) Does the Document Shepherd have any specific concerns or
        issues with this document that the Responsible Area Director
        and/or the IESG should be aware of? For example, perhaps he
        or she is uncomfortable with certain parts of the document, or
        has concerns whether there really is a need for it. In any
        event, if the WG has discussed those issues and has indicated
        that it still wishes to advance the document, detail those
        concerns here. Has an IPR disclosure related to this document
        been filed? If so, please include a reference to the
        disclosure and summarize the WG discussion and conclusion on
        this issue.


The shepherd has no concerns, however the companion document on the
AO base spec had experienced some deal of controversy.


  (1.e) How solid is the WG consensus behind this document? Does it
        represent the strong concurrence of a few individuals, with
        others being silent, or does the WG as a whole understand and
        agree with it? 


There has been no opposition to this document or its contents expressed
in the WG.



  (1.f) Has anyone threatened an appeal or otherwise indicated extreme
        discontent? If so, please summarise the areas of conflict in
        separate email messages to the Responsible Area Director. (It
        should be in a separate email because this questionnaire is
        entered into the ID Tracker.)


No.



  (1.g) Has the Document Shepherd personally verified that the
        document satisfies all ID nits? (See the Internet-Drafts Checklist
        and http://tools.ietf.org/tools/idnits/). Boilerplate checks are
        not enough; this check needs to be thorough. Has the document
        met all formal review criteria it needs to, such as the MIB
        Doctor, media type and URI type reviews?



idnits finds some spurious non-RFC3330-compliant IPv4 addresses (these
are mistaken section headings) and several cases of unused, missing, outdated,
or obsolete references.  These can be easily worked out between the authors
and the RFC Editor.



  (1.h) Has the document split its references into normative and
        informative? Are there normative references to documents that
        are not ready for advancement or are otherwise in an unclear
        state? If such normative references exist, what is the
        strategy for their completion? Are there normative references
        that are downward references, as described in [RFC3967]? If
        so, list these downward references to support the Area
        Director in the Last Call procedure for them [RFC3967].


The references are properly split.



  (1.i) Has the Document Shepherd verified that the document IANA
        consideration section exists and is consistent with the body
        of the document? If the document specifies protocol
        extensions, are reservations requested in appropriate IANA
        registries? Are the IANA registries clearly identified? If
        the document creates a new registry, does it define the
        proposed initial contents of the registry and an allocation
        procedure for future registrations? Does it suggest a
        reasonable name for the new registry? See [RFC5226]. If the
        document describes an Expert Review process has Shepherd
        conferred with the Responsible Area Director so that the IESG
        can appoint the needed Expert during the IESG Evaluation?



The IANA Considerations are present.  An IANA registry is described
and its initial contents are laid out.



  (1.j) Has the Document Shepherd verified that sections of the
        document that are written in a formal language, such as XML
        code, BNF rules, MIB definitions, etc., validate correctly in
        an automated checker?


Not Applicable.



  (1.k) The IESG approval announcement includes a Document
        Announcement Write-Up. Please provide such a Document
        Announcement Write-Up? Recent examples can be found in the
        "Action" announcements for approved documents. The approval
        announcement contains the following sections:

    Technical Summary
        Relevant content can frequently be found in the abstract
        and/or introduction of the document. If not, this may be
        an indication that there are deficiencies in the abstract
        or introduction.


From abstract:

  The TCP Authentication Option, TCP-AO, relies on security algorithms
  to provide authentication between two end-points.  There are many
  such algorithms available, and two TCP-AO systems cannot interoperate
  unless they are using the same algorithms.  This document specifies
  the algorithms and attributes that can be used in TCP-AO's current
  manual keying mechanism.



    Working Group Summary
        Was there anything in WG process that is worth noting? For
        example, was there controversy about particular points or
        were there decisions where the consensus was particularly
        rough?

N/A


    Document Quality
        Are there existing implementations of the protocol? Have a
        significant number of vendors indicated their plan to
        implement the specification? Are there any reviewers that
        merit special mention as having done a thorough review,
        e.g., one that resulted in important changes or a
        conclusion that the document had no substantive issues? If
        there was a MIB Doctor, Media Type or other expert review,
        what was its course (briefly)? In the case of a Media Type
        review, on what date was the request posted?

Vendors have expressed support for this work and begun implementing
it and sharing feedback with TCPM.
2010-02-22
03 Amy Vezza Draft Added by Amy Vezza in state Publication Requested
2010-02-22
03 Amy Vezza [Note]: 'Wesley Eddy (Wesley.M.Eddy@nasa.gov) is the document shepherd.' added by Amy Vezza
2010-02-10
02 (System) New version available: draft-ietf-tcpm-tcp-ao-crypto-02.txt
2009-10-28
01 (System) New version available: draft-ietf-tcpm-tcp-ao-crypto-01.txt
2009-09-06
00 (System) New version available: draft-ietf-tcpm-tcp-ao-crypto-00.txt