Internet DRAFT - draft-ralston-mimi-matrix-transport
draft-ralston-mimi-matrix-transport
More Instant Messaging Interoperability T. Ralston
Internet-Draft M. Hodgson
Intended status: Informational The Matrix.org Foundation C.I.C.
Expires: 10 November 2023 9 May 2023
Matrix Message Transport
draft-ralston-mimi-matrix-transport-01
Abstract
This document describes Linearized Matrix's transport considerations.
About This Document
This note is to be removed before publishing as an RFC.
The latest revision of this draft can be found at
https://turt2live.github.io/ietf-mimi-matrix-transport/draft-ralston-
mimi-matrix-transport.html. Status information for this document may
be found at https://datatracker.ietf.org/doc/draft-ralston-mimi-
matrix-transport/.
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This Internet-Draft will expire on 10 November 2023.
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Copyright Notice
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Table of Contents
1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 2
2. Transport Requirements . . . . . . . . . . . . . . . . . . . 2
3. Interoperability . . . . . . . . . . . . . . . . . . . . . . 3
4. Encryption . . . . . . . . . . . . . . . . . . . . . . . . . 3
5. Security Considerations . . . . . . . . . . . . . . . . . . . 3
6. Informative References . . . . . . . . . . . . . . . . . . . 3
Acknowledgments . . . . . . . . . . . . . . . . . . . . . . . . . 4
Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 4
1. Introduction
Linearized Matrix [I-D.ralston-mimi-linearized-matrix] describes an
API surface for accessing Matrix rooms in a simple, easy to
implement, fashion. Normally a Matrix room would be a Directed
Acyclic Graph, requiring servers to implement transport functions to
fill gaps, however with Linearized Matrix's API surface the transport
considerations are reduced to simply passing events (messages)
between servers.
2. Transport Requirements
*TODO*: This section needs a lot more words.
* HTTPS+JSON for ease of use (or similar)
* Should be reliable (not require constant connection, resilient to
network faults where possible)
* Should be simple to understand (RESTful, for example)
* Exact details TBD.
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3. Interoperability
Matrix's split of Federation and Client-Server APIs allow homeservers
to implement the API surface which is most relevant for its
application. For interoperability, only the Federation API is
relevant. The APIs have been designed to intrinsically support load
balancing and active/active horizontal scaling - for instance, it's
valid for different parts of a server to race together when sending a
message in a room, avoiding the need for global locks within the
server.
*TODO*: Is this still true with Linearized Matrix? Can we really
avoid locks, or are we going to need both active servers to behave
the same?
The steps needed for an existing system to be interoperable with
another over Matrix would mean implementing portions of the
Federation API.
*TODO*: Define that minimized API surface (much of the Federation API
is actually for DAGs, which we don't care about here).
4. Encryption
End-to-end Encryption is deliberately layered on top of the Matrix
transport (Client-Server or Federation APIs). Currently a
combination of Double Ratchet (Olm) encryption and group ratchet
encryption (Megolm) is specified in the End-to-End Encryption section
of the Client-Server API [CSEncryptionApi], but Matrix over MLS
[I-D.ietf-mls-protocol] (with minor bookkeeping to compensate for the
lack of a centralised sequencing function in Matrix) is being
specified as DMLS. [DMLS]
5. Security Considerations
TODO Security. Matrix has its own threat model that needs to be
described here to protect against malicious actors (at the transport
level).
6. Informative References
[CSEncryptionApi]
The Matrix.org Foundation C.I.C., "End-to-End Encryption |
Client-Server API", 2022, <https://spec.matrix.org/v1.4/
client-server-api/#end-to-end-encryption>.
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[DMLS] Chathi, H., "Decentralised MLS", Web
https://gitlab.matrix.org/matrix-org/mls-ts/-
/blob/dd57bc25f6145ddedfb6d193f6baebf5133db7ed/
decentralised.org, 2021, <https://gitlab.matrix.org/
matrix-org/mls-ts/-
/blob/dd57bc25f6145ddedfb6d193f6baebf5133db7ed/
decentralised.org>.
[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.ralston-mimi-linearized-matrix]
Ralston, T. and M. Hodgson, "Linearized Matrix API", Work
in Progress, Internet-Draft, draft-ralston-mimi-
linearized-matrix-00, 25 March 2023,
<https://datatracker.ietf.org/doc/html/draft-ralston-mimi-
linearized-matrix-00>.
Acknowledgments
TODO acknowledge.
Authors' Addresses
Travis Ralston
The Matrix.org Foundation C.I.C.
Email: travisr@matrix.org
Matthew Hodgson
The Matrix.org Foundation C.I.C.
Email: matthew@matrix.org
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