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Record Size Limit Extension for TLS
RFC 8449

Revision differences

Document history

Date Rev. By Action
2018-12-19
03 (System)
Received changes through RFC Editor sync (changed abstract to 'An extension to Transport Layer Security (TLS) is defined that allows endpoints to negotiate the maximum …
Received changes through RFC Editor sync (changed abstract to 'An extension to Transport Layer Security (TLS) is defined that allows endpoints to negotiate the maximum size of protected records that each will send the other.

This replaces the maximum fragment length extension defined in RFC 6066.')
2018-08-10
03 (System)
Received changes through RFC Editor sync (created alias RFC 8449, changed title to 'Record Size Limit Extension for TLS', changed abstract to 'An extension …
Received changes through RFC Editor sync (created alias RFC 8449, changed title to 'Record Size Limit Extension for TLS', changed abstract to 'An extension to Transport Layer Security (TLS) is defined that allows endpoints to negotiate the maximum size of protected records that each will send the other.', changed standardization level to Proposed Standard, changed state to RFC, added RFC published event at 2018-08-10, changed IESG state to RFC Published, created updates relation between draft-ietf-tls-record-limit and RFC 6066)
2018-08-10
03 (System) RFC published
2018-08-07
03 (System) RFC Editor state changed to AUTH48-DONE from AUTH48
2018-08-06
03 (System) RFC Editor state changed to AUTH48 from RFC-EDITOR
2018-08-06
03 (System) RFC Editor state changed to RFC-EDITOR from EDIT
2018-07-03
03 (System) IANA Action state changed to RFC-Ed-Ack from Waiting on RFC Editor
2018-07-02
03 (System) IANA Action state changed to Waiting on RFC Editor from Waiting on Authors
2018-07-02
03 (System) IANA Action state changed to Waiting on Authors from In Progress
2018-07-02
03 (System) IANA Action state changed to In Progress from On Hold
2018-05-31
03 (System) IANA Action state changed to On Hold from Waiting on Authors
2018-05-31
03 (System) IANA Action state changed to Waiting on Authors from On Hold
2018-05-31
03 (System) IANA Action state changed to On Hold from In Progress
2018-05-29
03 (System) RFC Editor state changed to EDIT
2018-05-29
03 (System) IESG state changed to RFC Ed Queue from Approved-announcement sent
2018-05-29
03 (System) Announcement was received by RFC Editor
2018-05-29
03 (System) IANA Action state changed to In Progress
2018-05-29
03 Cindy Morgan IESG state changed to Approved-announcement sent from Approved-announcement to be sent
2018-05-29
03 Cindy Morgan IESG has approved the document
2018-05-29
03 Cindy Morgan Closed "Approve" ballot
2018-05-29
03 Cindy Morgan Ballot approval text was generated
2018-05-29
03 Benjamin Kaduk IESG state changed to Approved-announcement to be sent from Approved-announcement to be sent::AD Followup
2018-05-29
03 Benjamin Kaduk RFC Editor Note was changed
2018-05-29
03 Benjamin Kaduk RFC Editor Note for ballot was generated
2018-05-29
03 Benjamin Kaduk RFC Editor Note for ballot was generated
2018-05-17
03 (System) Sub state has been changed to AD Followup from Revised ID Needed
2018-05-17
03 Martin Thomson New version available: draft-ietf-tls-record-limit-03.txt
2018-05-17
03 (System) New version approved
2018-05-17
03 (System) Request for posting confirmation emailed to previous authors: Martin Thomson
2018-05-17
03 Martin Thomson Uploaded new revision
2018-05-17
03 Martin Thomson Uploaded new revision
2018-04-05
02 Cindy Morgan IESG state changed to Approved-announcement to be sent::Revised I-D Needed from IESG Evaluation
2018-04-05
02 Martin Vigoureux
[Ballot comment]
Hello, I'm not a TLS expert so please disregard if this is irrelevant.
Document says:
  Clients that depend on having a small …
[Ballot comment]
Hello, I'm not a TLS expert so please disregard if this is irrelevant.
Document says:
  Clients that depend on having a small record size MAY continue to
  advertise the "max_fragment_length".

Do you mean:
  Clients that depend on having a small record size MAY continue to
  advertise the "max_fragment_length" *only*.

If so, what would be the behaviour of a server that supports both "max_fragment_length" and "record_size_limit" in that situation?
2018-04-05
02 Martin Vigoureux [Ballot Position Update] New position, No Objection, has been recorded for Martin Vigoureux
2018-04-04
02 Benjamin Kaduk Ballot approval text was generated
2018-04-04
02 Terry Manderson [Ballot Position Update] New position, Yes, has been recorded for Terry Manderson
2018-04-04
02 Ignas Bagdonas [Ballot Position Update] New position, No Objection, has been recorded for Ignas Bagdonas
2018-04-03
02 Adam Roach
[Ballot comment]
Thanks to everyone who contributed work towards this document.

---------------------------------------------------------------------------

§4:

>  MUST NOT send a value higher than the protocol-defined maximum record …
[Ballot comment]
Thanks to everyone who contributed work towards this document.

---------------------------------------------------------------------------

§4:

>  MUST NOT send a value higher than the protocol-defined maximum record
>  size unless explicitly allowed by such a future version or extension.

Presumably, recipients MUST gracefully accept values higher than the maximum
record size?  That is implied by this text (and the text that follows), but
given how TLS frequently aborts connections at the first sign of any
irregularity, it's probably worth saying explicitly.

---------------------------------------------------------------------------

§4:

>  a DTLS endpoint that
>  receives a record larger than its advertised limit MAY either
>  generate a fatal "record_overflow" alert or discard the record.

I'm concerned about the interaction between the option to discard the record and
protocols that perform retransmission of lost packets over DTLS (e.g., proposals
such as draft-rescorla-quic-over-dtls). In the case that an oversized packet is
simply discarded, retransmissions of that (presumably still oversized) packet
will take a while to time out (I'm not particularly well-versed in QUIC, but
assume it has characteristics similar to TCP's ~nine-minute timeout), which
would result in really bad user experiences.  Is there rationale for this optionality?
It would seem to be cleaner if the response were simply to always send a fatal
error.

If this optionality is retained, please at least consider adding text describing
the impact of discarding oversized packets when used with a reliable protocol.

---------------------------------------------------------------------------

§4.1:

>  In TLS 1.2, block ciphers allow between 1 and 256 octets of padding.

nit: The formulation "between X and Y" is ambiguous as to whether X and Y are
included in the range. Consider rephrasing as "...from 1 to 256...".
2018-04-03
02 Adam Roach [Ballot Position Update] New position, Yes, has been recorded for Adam Roach
2018-04-03
02 Suresh Krishnan [Ballot Position Update] New position, No Objection, has been recorded for Suresh Krishnan
2018-04-03
02 Ben Campbell [Ballot Position Update] New position, Yes, has been recorded for Ben Campbell
2018-04-03
02 Deborah Brungard [Ballot Position Update] New position, No Objection, has been recorded for Deborah Brungard
2018-04-03
02 Alissa Cooper [Ballot Position Update] New position, No Objection, has been recorded for Alissa Cooper
2018-04-03
02 Benjamin Kaduk IESG state changed to IESG Evaluation from Waiting for Writeup
2018-04-02
02 Spencer Dawkins
[Ballot comment]
This is a nit, but just to make sure …

  The "record_size_limit" extension replaces the "max_fragment_length"
  extension [RFC6066].  A …
[Ballot comment]
This is a nit, but just to make sure …

  The "record_size_limit" extension replaces the "max_fragment_length"
  extension [RFC6066].  A server that supports the "record_size_limit"
  extension MUST ignore and "max_fragment_length" that appears in a
                        ^^^
the "and" should be "any", shouldn't it?

  ClientHello if both extensions appear.  A client MUST treat receipt
  of both "max_fragment_length" and "record_size_limit" as a fatal
  error, and SHOULD generate an "illegal_parameter" alert.
2018-04-02
02 Spencer Dawkins [Ballot Position Update] New position, No Objection, has been recorded for Spencer Dawkins
2018-04-02
02 Warren Kumari [Ballot comment]
Thanks to Éric Vyncke for his OpsDir review of this document.
2018-04-02
02 Warren Kumari [Ballot Position Update] New position, No Objection, has been recorded for Warren Kumari
2018-04-01
02 Alexey Melnikov [Ballot Position Update] New position, Yes, has been recorded for Alexey Melnikov
2018-03-31
02 Eric Rescorla
[Ballot comment]
I apologize for not catching the point about "negotiated" earlier.


  An Authentication Encryption with Additional Data (AEAD) ciphers (see
  [RFC5116 …
[Ballot comment]
I apologize for not catching the point about "negotiated" earlier.


  An Authentication Encryption with Additional Data (AEAD) ciphers (see
  [RFC5116]) API requires that an entire record be present to decrypt
Nit: "An" .. "ciphers" do not agree.



  incremental processing of records minimally exposes endpoints to the
  risk of forged data.
This seems a bit weak. It's just not an acceptable practices to incrementally process.



  Unprotected messages - handshake messages in particular - are not
  subject to this limit.
This text is a bit confusing. Consider a case where a server recognizes the extension and has no limit, but the client offers one.

In that case, the server can either:

Return an extension with a max-size limit
Not return the extension
I think we want the server to conform to the client's limit in any case, but "negotiated" is unclear.


  they have no need to limit the size of records.  This allows servers
  to apply a limit at their discretion.  If this extension is not
  negotiated, endpoints can send records of any size permitted by the
I think by "apply" you mean "request" or "advertise"
2018-03-31
02 Eric Rescorla [Ballot Position Update] New position, Yes, has been recorded for Eric Rescorla
2018-03-29
02 Mirja Kühlewind
[Ballot comment]
Thanks for the well written doc!

One minor comment the title of sec 5: not sure if "deprecating" is the best word as …
[Ballot comment]
Thanks for the well written doc!

One minor comment the title of sec 5: not sure if "deprecating" is the best word as that maybe be read as "moved to historic" in IETF world...

Tiny typo in sec 5:
s/and "max_fragment_length"/an "max_fragment_length"/
2018-03-29
02 Mirja Kühlewind [Ballot Position Update] New position, No Objection, has been recorded for Mirja Kühlewind
2018-03-28
02 Benjamin Kaduk Ballot has been issued
2018-03-28
02 Benjamin Kaduk [Ballot Position Update] New position, Yes, has been recorded for Benjamin Kaduk
2018-03-28
02 Benjamin Kaduk Created "Approve" ballot
2018-03-28
02 Benjamin Kaduk Ballot writeup was changed
2018-03-21
02 Cindy Morgan Shepherding AD changed to Benjamin Kaduk
2018-03-20
02 (System) IESG state changed to Waiting for Writeup from In Last Call
2018-03-16
02 Francis Dupont Request for Telechat review by GENART Completed: Ready. Reviewer: Francis Dupont.
2018-03-01
02 Tero Kivinen Request for Telechat review by SECDIR Completed: Has Nits. Reviewer: Alan DeKok.
2018-02-23
02 Amy Vezza
The following Last Call announcement was sent out (ends 2018-03-20):

From: The IESG
To: IETF-Announce
CC: draft-ietf-tls-record-limit@ietf.org, Sean Turner , Kathleen.Moriarty.ietf@gmail.com, tls@ietf.org, …
The following Last Call announcement was sent out (ends 2018-03-20):

From: The IESG
To: IETF-Announce
CC: draft-ietf-tls-record-limit@ietf.org, Sean Turner , Kathleen.Moriarty.ietf@gmail.com, tls@ietf.org, sean@sn3rd.com, tls-chairs@ietf.org
Reply-To: ietf@ietf.org
Sender:
Subject: EXTENDED Last Call:  (Record Size Limit Extension for Transport Layer Security (TLS)) to Proposed Standard


The IESG has received a request from the Transport Layer Security WG (tls) to
consider the following document: - 'Record Size Limit Extension for Transport
Layer Security (TLS)'
  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
ietf@ietf.org mailing lists by 2018-03-20. 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


  An extension to Transport Layer Security (TLS) is defined that allows
  endpoints to negotiate the maximum size of protected records that
  each will send the other.

  This replaces the maximum fragment length extension defined in RFC
  6066
.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-tls-record-limit/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-tls-record-limit/ballot/


No IPR declarations have been submitted directly on this I-D.




2018-02-23
02 Amy Vezza Last call announcement was changed
2018-02-23
02 Amy Vezza Last call announcement was generated
2018-02-23
02 (System) IANA Review state changed to IANA OK - Actions Needed from IANA - Review Needed
2018-02-23
02 Amanda Baber
(Via drafts-lastcall@iana.org): IESG/Authors/WG Chairs:

The IANA Services Operator has completed its review of draft-ietf-tls-record-limit-02. If any part of this review is inaccurate, please let …
(Via drafts-lastcall@iana.org): IESG/Authors/WG Chairs:

The IANA Services Operator has completed its review of draft-ietf-tls-record-limit-02. If any part of this review is inaccurate, please let us know.

We understand that upon approval of this document, two registry actions must be performed. However, the second action and part of the first depend on the approval of another document.

First, the following entry will be added to the ExtensionType Values registry at

https://www.iana.org/assignments/tls-extensiontype-values

Value: TBD
Extension Name: record_size_limit
Reference: [this document]

After the new columns are added by draft-ietf-tls-iana-registry-updates, which has not yet been approved, the entry for the "Recommended" column will be "Yes," and the "TLS 1.3" column will be marked "Encrypted."

Second, after draft-ietf-tls-iana-registry-updates is approved and creates the "Recommended" column in that registry, the "Recommended" column for "max_fragment_length" will be marked "No."

Note:  The actions requested in this document will not be completed until the document has been approved for publication as an RFC. This message is meant only to confirm the list of actions that will be performed.

Thank you,

Amanda Baber
Lead IANA Services Specialist
2018-02-23
02 Kathleen Moriarty Telechat date has been changed to 2018-04-05 from 2018-03-08
2018-02-22
02 Jean Mahoney Request for Telechat review by GENART is assigned to Francis Dupont
2018-02-22
02 Jean Mahoney Request for Telechat review by GENART is assigned to Francis Dupont
2018-02-22
02 Tero Kivinen Request for Telechat review by SECDIR is assigned to Alan DeKok
2018-02-22
02 Tero Kivinen Request for Telechat review by SECDIR is assigned to Alan DeKok
2018-02-21
02 Éric Vyncke Request for Telechat review by OPSDIR Completed: Has Nits. Reviewer: Éric Vyncke. Sent review to list.
2018-02-21
02 Gunter Van de Velde Request for Telechat review by OPSDIR is assigned to Éric Vyncke
2018-02-21
02 Gunter Van de Velde Request for Telechat review by OPSDIR is assigned to Éric Vyncke
2018-02-20
02 Amy Vezza IANA Review state changed to IANA - Review Needed
2018-02-20
02 Amy Vezza
The following Last Call announcement was sent out (ends 2018-03-06):

From: The IESG
To: IETF-Announce
CC: draft-ietf-tls-record-limit@ietf.org, Sean Turner , Kathleen.Moriarty.ietf@gmail.com, tls@ietf.org, …
The following Last Call announcement was sent out (ends 2018-03-06):

From: The IESG
To: IETF-Announce
CC: draft-ietf-tls-record-limit@ietf.org, Sean Turner , Kathleen.Moriarty.ietf@gmail.com, tls@ietf.org, sean@sn3rd.com, tls-chairs@ietf.org
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (Record Size Limit Extension for Transport Layer Security (TLS)) to Proposed Standard


The IESG has received a request from the Transport Layer Security WG (tls) to
consider the following document: - 'Record Size Limit Extension for Transport
Layer Security (TLS)'
  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
ietf@ietf.org mailing lists by 2018-03-06. 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


  An extension to Transport Layer Security (TLS) is defined that allows
  endpoints to negotiate the maximum size of protected records that
  each will send the other.

  This replaces the maximum fragment length extension defined in RFC
  6066
.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-tls-record-limit/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-tls-record-limit/ballot/


No IPR declarations have been submitted directly on this I-D.




2018-02-20
02 Amy Vezza IESG state changed to In Last Call from Last Call Requested
2018-02-20
02 Amy Vezza Last call announcement was changed
2018-02-19
02 Gunter Van de Velde Request for Telechat review by OPSDIR is assigned to (None)
2018-02-19
02 Gunter Van de Velde Request for Telechat review by OPSDIR is assigned to (None)
2018-02-19
02 Gunter Van de Velde Request for Telechat review by OPSDIR is assigned to Éric Vyncke
2018-02-19
02 Gunter Van de Velde Request for Telechat review by OPSDIR is assigned to Éric Vyncke
2018-02-16
02 Kathleen Moriarty Last call was requested
2018-02-16
02 Kathleen Moriarty Ballot approval text was generated
2018-02-16
02 Kathleen Moriarty Ballot writeup was generated
2018-02-16
02 Kathleen Moriarty IESG state changed to Last Call Requested from Publication Requested
2018-02-16
02 Kathleen Moriarty Last call announcement was generated
2018-02-16
02 Kathleen Moriarty Placed on agenda for telechat - 2018-03-08
2018-02-16
02 Cindy Morgan Last call announcement was generated
2018-02-15
02 Sean Turner
1. Summary

Sean Turner is the document shepherd.
Kathleen Moriarty is the responsible Area Director.

This draft defines a TLS extension to negotiate the maximum …
1. Summary

Sean Turner is the document shepherd.
Kathleen Moriarty is the responsible Area Director.

This draft defines a TLS extension to negotiate the maximum size of protected records that each peers sends.  This mechanism replaces the maximum fragment length extension defined in RFC 6066.  It’s standards track because it updates RFC 6066, which is a PS.

2. Review and Consensus

The draft was very well received by the WG, resulting in minimal, minor comments.  There were two threads that contain all of the WG mailing list traffic related to this draft:
https://mailarchive.ietf.org/arch/msg/tls/l700Sq2m5nJDRfaS1VPk8w9sHKg
https://mailarchive.ietf.org/arch/msg/tls/tRwQqjH0-nqZec_9BTa97AfDsd8
Unlike other TLS-related topics, this WG settled on a solution quickly and consensus was very easily found.


3. Intellectual Property

Martin confirmed his direct, personal knowledge of any IPR related to this document has already been disclosed, in conformance with BCPs 78 and 79.

4. Other Points

N/A
2018-02-15
02 Sean Turner Responsible AD changed to Kathleen Moriarty
2018-02-15
02 Sean Turner IETF WG state changed to Submitted to IESG for Publication from WG Consensus: Waiting for Write-Up
2018-02-15
02 Sean Turner IESG state changed to Publication Requested
2018-02-15
02 Sean Turner IESG process started in state Publication Requested
2018-02-15
02 Sean Turner Tag Revised I-D Needed - Issue raised by WG cleared.
2018-02-15
02 Sean Turner IETF WG state changed to WG Consensus: Waiting for Write-Up from Waiting for WG Chair Go-Ahead
2018-02-15
02 Martin Thomson New version available: draft-ietf-tls-record-limit-02.txt
2018-02-15
02 (System) New version approved
2018-02-15
02 (System) Request for posting confirmation emailed to previous authors: Martin Thomson
2018-02-15
02 Martin Thomson Uploaded new revision
2018-02-15
02 Martin Thomson Uploaded new revision
2018-02-15
01 Sean Turner Tag Revised I-D Needed - Issue raised by WG set.
2018-02-15
01 Sean Turner IETF WG state changed to Waiting for WG Chair Go-Ahead from In WG Last Call
2018-02-01
01 Sean Turner Changed document writeup
2018-02-01
01 Sean Turner Changed document writeup
2018-01-21
01 Sean Turner IETF WG state changed to In WG Last Call from WG Document
2017-11-21
01 Sean Turner Notification list changed to Sean Turner <sean@sn3rd.com>
2017-11-21
01 Sean Turner Document shepherd changed to Sean Turner
2017-10-31
01 Sean Turner Changed consensus to Yes from Unknown
2017-10-31
01 Sean Turner Intended Status changed to Proposed Standard from None
2017-09-07
01 Martin Thomson New version available: draft-ietf-tls-record-limit-01.txt
2017-09-07
01 (System) New version approved
2017-09-07
01 (System) Request for posting confirmation emailed to previous authors: Martin Thomson
2017-09-07
01 Martin Thomson Uploaded new revision
2017-09-05
00 Sean Turner This document now replaces draft-thomson-tls-record-limit instead of None
2017-08-28
00 Martin Thomson New version available: draft-ietf-tls-record-limit-00.txt
2017-08-28
00 (System) New version approved
2017-08-28
00 Martin Thomson Request for posting confirmation emailed  to submitter and authors: Martin Thomson
2017-08-28
00 Martin Thomson Uploaded new revision