More Instant Messaging Interoperability (MIMI) using HTTPS and MLS

Rohan Mahy Wire Email: rohan.mahy@wire.com · events

GET /identifierDiscovery/{domain}

enum {
  reserved(0),
  handle(1),
  nick(2),
  email(3),
  phone(4),
  partialName(5),
  wholeProfile(6),
  oidcStdClaim(7),
  vcardField(8),
  (255)
} IdentifierType;

struct {
  IdentifierType type;
  string searchValue;
  select(type) {
     case oidcStdClaim:
       string claimName;
    case vcardField:
       string fieldName;
  };
} IdentifierRequest;

enum {
  success(0),
  notFound(1),
  ambiguous(2),
  forbidden(3),
  unsupportedField(4),
  (255)
} IdentifierDiscoveryCode;

struct {
  IdentifierDiscoverCode responseCode;
  IdentifierUri uri;
} IdentifierResponse;

enum {
   reserved(0),
   mimi10(1), // MIMI 1.0
   (65535)
} ProtocolVersion;

enum {
   reserverd(0),
   event(1),
   event_response(2),
} MIMIMessageType;

struct {
   // The protocol version this event is created for.
   ProtocolVersion version;

   // The room ID where the event is sent in context of.
   opaque roomId;

   // Who or what sent this event. For example, a user ID.
   opaque sender;

   MIMIMessageType message_type;
   select (MIMIMessage.message_type) {
      case event:
        Event event;
      case event_response:
        EventResponse response;
   }
} MIMIMessage

// See the "MIMI Event Types" IANA registry for values.
// Example: "m.room.info"
opaque EventType;

struct {
   // The event type.
   EventType type;

   // Additional fields may be present as dependent on event type.
   select (Event.type) {
      case "m.room.user":
         // MLSMessage containing a UserEvent proposal
         MLSMessage user_event_proposal;
      case "ds.proposal":
         DSRequest ds_proposal;
      case "ds.commit":
         DSRequest ds_commit;
      case "ds.fetch_key_packages":
         DSRequest fetch_key_packages;
      case "ds.fetch_group_info":
         DSRequest fetch_group_info;
      case "ds.send_message":
         DSRequest send_message;
      // more cases as required by registry
   }
} Event;

enum {
  reserved(0),
  ok(1),
  key_package(2),
  group_info(3),
  error(4),
} EventResponseType

enum {
  // TODO
} EventErrorType

struct {
  EventErrorType type;

   select (EventResponse.type) {
      // TODO
   }
} EventError

struct {
   EventResponseType type;

   // Additional fields may be present as dependent on event type.
   select (EventResponse.type) {
      case ok:
         struct {};
      case key_package:
         DSResponse key_package;
      case group_info:
         DSResponse group_info;
      case error:
         EventError error;
   }
} EventResponse

struct {
   opaque user_id;
   opaque role;
   ParticipationState state;
} ParticipantData

struct {
  opaque room_id;
  ParticipantData participants<V>;
  // TODO: Add any remaining room data
} RoomState;

struct {
  DSRequest proposal;
} DSProposal

struct {
  DSRequest commitBundle;
} DSCommit

struct {
  DSRequest fetch_key_packages;
} DSFetchKeyPackages

struct {
  DSRequest fetch_group_info;
} DSFetchGroupInfo

struct {
  DSRequest send_message;
} DSSendMessage

struct {
  RoomState room_state;
} InfoEvent;

enum {
   invite,  // "Invited" state.
   join,    // "Joined" state.
   ban,     // "Banned" state.
   knock,   // "Knocking" state.
} ParticipationState;

enum {
   invite,
   join,
   leave,
   ban,
   knock,
} ParticipationStateChange;

struct {
   // The user ID being affected by this participation state change.
   opaque targetUserId;

   // The new participation state for the target user. "Leave" removes
   // the user from the list.
   ParticipationStateChange state;

   // Optional human-readable reason for the change. Typically most
   // useful on bans and knocks.
   opaque [[reason]];
   optional<Certificate> follower_server_certificate;
} UserEvent;

GET https://example.org/.well-known/mimi/domain

Response
mimi.example.org

POST /send
Content-Type: application/octet-stream

Body
TLS-serialized Event

Response
TLS-serialized Event, or empty if no useful event.

struct {
   // The `m.room.user` invite event.
   Event invite;

   // The room creation information.
   InfoEvent roomInfo;
} CheckInviteRequest;

POST /check-invite
Content-Type: application/octet-stream

Body
TLS-serialized CheckInviteRequest

Response
Any meaningful information. The pass/fail is identified by the HTTP response
status code, not the response body.

Internet-Draft	MIMI+MLS Protocol	November 2023
Ralston, et al.	Expires 9 May 2024	[Page]