Skip to content

Latest commit

 

History

History
121 lines (92 loc) · 4.06 KB

draft-mahy-mls-room-policy-ext.md

File metadata and controls

121 lines (92 loc) · 4.06 KB
Raw

title: A Messaging Layer Security (MLS) extension for More Instant Messaging Interoperability (MIMI) room policies abbrev: MLS Extension for MIMI Room Policy docname: draft-mahy-mls-room-policy-ext-latest ipr: trust200902 submissiontype: IETF # also: "independent", "IAB", or "IRTF"area: art workgroup: MLS area: sec category: info keyword:

  • room policy
  • MIMI
  • room_policy
  • group chat

stand_alone: yes pi: [toc, sortrefs, symrefs]

venue: group: MLS type: Working Group mail: [email protected] arch: https://mailarchive.ietf.org/arch/browse/mls/ github: rohan-wire/mls-room-policy-ext/

latest: https://github.com/rohan-wire/mls-room-policy-ext/latest

author:

normative:

informative:

--- 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.

--- middle

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.

Conventions and Definitions

{::boilerplate bcp14-tagged}

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].

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.

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).

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

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

--- back