Internet DRAFT - draft-mahy-mls-room-policy-ext
draft-mahy-mls-room-policy-ext
MLS R. Mahy
Internet-Draft Wire
Intended status: Informational 10 July 2023
Expires: 11 January 2024
A Messaging Layer Security (MLS) extension for More Instant Messaging
Interoperability (MIMI) room policies
draft-mahy-mls-room-policy-ext-00
Abstract
This document describes a Message Layer Security (MLS) GroupContext
extension to include More Instant Messaging Interoperability (MIMI)
group chat (room) policy inside an MLS group. This allows all users
in a group to agree on the current policy and make authorization
decisions accordingly.
About This Document
This note is to be removed before publishing as an RFC.
Status information for this document may be found at
https://datatracker.ietf.org/doc/draft-mahy-mls-room-policy-ext/.
Discussion of this document takes place on the MLS Working Group
mailing list (mailto:mls@ietf.org), which is archived at
https://mailarchive.ietf.org/arch/browse/mls/. Subscribe at
https://www.ietf.org/mailman/listinfo/mls/.
Source for this draft and an issue tracker can be found at
https://github.com/rohan-wire/mls-room-policy-ext/.
Status of This Memo
This Internet-Draft is submitted in full conformance with the
provisions of BCP 78 and BCP 79.
Internet-Drafts are working documents of the Internet Engineering
Task Force (IETF). Note that other groups may also distribute
working documents as Internet-Drafts. The list of current Internet-
Drafts is at https://datatracker.ietf.org/drafts/current/.
Internet-Drafts are draft documents valid for a maximum of six months
and may be updated, replaced, or obsoleted by other documents at any
time. It is inappropriate to use Internet-Drafts as reference
material or to cite them other than as "work in progress."
Mahy Expires 11 January 2024 [Page 1]
Internet-Draft MLS Extension for MIMI Room Policy July 2023
This Internet-Draft will expire on 11 January 2024.
Copyright Notice
Copyright (c) 2023 IETF Trust and the persons identified as the
document authors. All rights reserved.
This document is subject to BCP 78 and the IETF Trust's Legal
Provisions Relating to IETF Documents (https://trustee.ietf.org/
license-info) in effect on the date of publication of this document.
Please review these documents carefully, as they describe your rights
and restrictions with respect to this document. Code Components
extracted from this document must include Revised BSD License text as
described in Section 4.e of the Trust Legal Provisions and are
provided without warranty as described in the Revised BSD License.
Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Conventions and Definitions . . . . . . . . . . . . . . . . . 2
3. Extension Description . . . . . . . . . . . . . . . . . . . . 3
4. Security Considerations . . . . . . . . . . . . . . . . . . . 3
5. IANA Considerations . . . . . . . . . . . . . . . . . . . . . 3
5.1. room_policy MLS Extension Type . . . . . . . . . . . . . 4
6. Normative References . . . . . . . . . . . . . . . . . . . . 4
Author's Address . . . . . . . . . . . . . . . . . . . . . . . . 4
1. Introduction
The More Instant Messaging Interoperability (MIMI) group chat
framework [I-D.mahy-mimi-group-chat] defines a room policy format.
This document describes a Message Layer Security (MLS)
[I-D.ietf-mls-protocol] GroupContext extension that allows all users
in a group to agree on the current policy and make authorization
decisions accordingly.
2. Conventions and Definitions
The key words "MUST", "MUST NOT", "REQUIRED", "SHALL", "SHALL NOT",
"SHOULD", "SHOULD NOT", "RECOMMENDED", "NOT RECOMMENDED", "MAY", and
"OPTIONAL" in this document are to be interpreted as described in
BCP 14 [RFC2119] [RFC8174] when, and only when, they appear in all
capitals, as shown here.
The terms MLS client, MLS group, GroupContext, Commit, Proposal,
GroupContextExtensions Proposal, andrequired_capabilities have the
same meanings as in the MLS protocol [@!I-D.ietf-mls-protocol].
Mahy Expires 11 January 2024 [Page 2]
Internet-Draft MLS Extension for MIMI Room Policy July 2023
3. Extension Description
This document specifies a GroupContext MLS extension room_policy of
type RoomPolicy (defined in Section 8 of [I-D.mahy-mimi-group-chat]).
The syntax is described using the TLS Presentation Language
[@!RFC8446].
RoomPolicy room_policy;
An MLS client which implements this specification SHOULD include the
room_policy extension in the extensions field in the GroupContext of
groups it creates which have an associated room policy. It includes
a machine readable description of the room policy sufficient for all
clients in the group to authorize MLS primitives (like a Commit with
an Add Proposal). As new members of the group are added or removed,
the member which Commits these membership changes is expected to
maintain the room_policy up-to-date, and consistent with the
membership of the group by also including an appropriate
GroupContextExtensions Proposal any time the policy changes. It also
allows a client to inspect the room_policy before joining to
determine if the policies are consistent with its own.
4. Security Considerations
The Security Considerations of MLS apply. The authorization rules
for the RoomPolicy object are described in detail in
[I-D.mahy-mimi-group-chat].
Improper use of the extension in this document could allow the
creator of an MLS group or the sender of a GroupContextExtensions
Proposal to maliciously modify or subvert the policies of a group
chat which could result in viewing private information about the
participants of the room, loss of confidentiality of the contents of
the room (after subverting the policies and until the policies are
corrected), and injecting potentially unwanted messages into the room
(spam, abuse, phishing, and attempted impersonation).
5. IANA Considerations
This document proposes registration of a new MLS Extension Type.
RFC EDITOR: Please replace XXXX throughout with the RFC number
assigned to this document
Mahy Expires 11 January 2024 [Page 3]
Internet-Draft MLS Extension for MIMI Room Policy July 2023
5.1. room_policy MLS Extension Type
The room_policy MLS Extension Type is used inside GroupContext
objects. It contains a RoomPolicy object as defined in Section 8 of
[I-D.mahy-mimi-group-chat], representing the room policy for the MLS
group corresponding with the room.
Template:
Value: 0x000B
Name: room_policy
Message(s): This extension may appear in GroupContext objects
Recommended: Y
Reference: RFC XXXX
6. Normative References
[I-D.ietf-mls-protocol]
Barnes, R., Beurdouche, B., Robert, R., Millican, J.,
Omara, E., and K. Cohn-Gordon, "The Messaging Layer
Security (MLS) Protocol", Work in Progress, Internet-
Draft, draft-ietf-mls-protocol-20, 27 March 2023,
<https://datatracker.ietf.org/doc/html/draft-ietf-mls-
protocol-20>.
[I-D.mahy-mimi-group-chat]
Mahy, R., "Group Chat Framework for More Instant Messaging
Interoperability (MIMI)", Work in Progress, Internet-
Draft, draft-mahy-mimi-group-chat-00, 10 July 2023,
<https://datatracker.ietf.org/doc/html/draft-mahy-mimi-
group-chat-00>.
[RFC2119] Bradner, S., "Key words for use in RFCs to Indicate
Requirement Levels", BCP 14, RFC 2119,
DOI 10.17487/RFC2119, March 1997,
<https://www.rfc-editor.org/rfc/rfc2119>.
[RFC8174] Leiba, B., "Ambiguity of Uppercase vs Lowercase in RFC
2119 Key Words", BCP 14, RFC 8174, DOI 10.17487/RFC8174,
May 2017, <https://www.rfc-editor.org/rfc/rfc8174>.
Author's Address
Rohan Mahy
Wire
Email: rohan.mahy@wire.com
Mahy Expires 11 January 2024 [Page 4]
