ChaCha20-Poly1305 Cipher Suites for Transport Layer Security (TLS)
draft-ietf-tls-chacha20-poly1305-04

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

IANA has completed its review of draft-ietf-tls-chacha20-poly1305-04.txt. If any part of this review is inaccurate, please let us know.

IANA has a question about one of the actions requested in the IANA Considerations section of this document.

IANA understands that, upon approval of this document, there is a single action which IANA must complete.

In the TLS Cipher Suite Subregistry of the Transport Layer Security (TLS) Parameters registry located at:

https://www.iana.org/assignments/tls-parameters/

seven new entries are to be added to the registry as follows:

Value: Description: DTLS-OK: Reference:
{0xCC, 0xA8} TLS_ECDHE_RSA_WITH_CHACHA20_POLY1305_SHA256 [ RFC-to-be ]
{0xCC, 0xA9} TLS_ECDHE_ECDSA_WITH_CHACHA20_POLY1305_SHA256 [ RFC-to-be ]
{0xCC, 0xAA} TLS_DHE_RSA_WITH_CHACHA20_POLY1305_SHA256 [ RFC-to-be ]
{0xCC, 0xAB} TLS_PSK_WITH_CHACHA20_POLY1305_SHA256 [ RFC-to-be ]
{0xCC, 0xAC} TLS_ECDHE_PSK_WITH_CHACHA20_POLY1305_SHA256 [ RFC-to-be ]
{0xCC, 0xAD} TLS_DHE_PSK_WITH_CHACHA20_POLY1305_SHA256 [ RFC-to-be ]
{0xCC, 0xAE} TLS_RSA_PSK_WITH_CHACHA20_POLY1305_SHA256 [ RFC-to-be ]

IANA understands that the cipher suite numbers provided in the draft are numbers used for cipher suite interoperability testing. If those values are available when the document is approved, IANA intends to use the suggested values.

The section of the registry where these values are assigned is maintained by Specification Required as defined by RFC 5266. As this document requests registrations in an Expert Review or Specification Required (see RFC 5226) registry, we will initiate the required Expert Review via a separate request. Expert review will need to be completed before your document can be approved for publication as an RFC.

IANA Question --> Please provide the value for DTLS-OK for each of these new registrations.

IANA understands that this is the only action required to be completed upon approval of this document.

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 only to confirm what actions will be performed. 


Thank you,

Sabrina Tanamal
IANA Specialist
ICANN

The following Last Call announcement was sent out:

From: The IESG
To: "IETF-Announce"
CC: "Sean Turner" , draft-ietf-tls-chacha20-poly1305@ietf.org, tls@ietf.org, stephen.farrell@cs.tcd.ie, sean@sn3rd.com, tls-chairs@ietf.org
Reply-To: ietf@ietf.org
Sender:
Subject: Last Call:  (ChaCha20-Poly1305 Cipher Suites 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:
- 'ChaCha20-Poly1305 Cipher Suites 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 2016-04-05. 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 describes the use of the ChaCha stream cipher and
  Poly1305 authenticator in the Transport Layer Security (TLS) and
  Datagram Transport Layer Security (DTLS) protocols.




The file can be obtained via
https://datatracker.ietf.org/doc/draft-ietf-tls-chacha20-poly1305/

IESG discussion can be tracked via
https://datatracker.ietf.org/doc/draft-ietf-tls-chacha20-poly1305/ballot/


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

I-D nits notes that the abstract doesn't mention the two RFCs being updated.
That is a useful practice (in case someone only sees the abstract) so we'll fix
it after IETF LC.

This draft normatively references RFCs 4492, 5489 and 7539 which
are algorithm definitions. If needed we will put those in the DownRef
registry after this last call concludes.

1. Summary

This draft specifies seven (7) chacha20-poly1305 ciphers that can be used with TLS and DTLS.  This is the “how to do chacha20-poly1305 with TLS” draft, where chacha20-poly1305 is defined in RFC 7539. These cipher suites are intended to be a back up to the AES-based suites in case of compromise.

As far as where you should point your fingers:
- Sean Turner is the document shepherd, and;
- Stephen Farrell is the responsible Area Director.

2. Review and Consensus

There’s probably on the order of 100 messages about this draft, and that shouldn’t come as a surprise because this draft is really just specifying IANA code points.  The real fireworks were on the CFRG list, and we thank them for taking that bullet(s).  The cipher suites proposed in the individual draft were modified based on WG input.  There were two WGLCs for this draft; the first didn’t generate the expected amount of review so a second WGLC was issued that did.  There was a debate as to whether the PRF digest should be changed to SHA-512 from SHA-256, but there was no consensus to make this change.

3. Intellectual Property

All disclosed as confirmed by the authors on 20160310.

4. Other Points:

IANA has already assigned the cipher suites and we thank them.

These algorithms are expected to be very widely implemented due their high performance in software implementations.  It’s currently in the deployed branches of BoringSSL GnuTLS, OpenSSL, and others.