synapse/synapse/api/constants.py

#
# This file is licensed under the Affero General Public License (AGPL) version 3.
#
# Copyright 2019 The Matrix.org Foundation C.I.C.
# Copyright 2017 Vector Creations Ltd
# Copyright 2014-2016 OpenMarket Ltd
# Copyright (C) 2023 New Vector, Ltd
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as
# published by the Free Software Foundation, either version 3 of the
# License, or (at your option) any later version.
#
# See the GNU Affero General Public License for more details:
# <https://www.gnu.org/licenses/agpl-3.0.html>.
#
# Originally licensed under the Apache License, Version 2.0:
# <http://www.apache.org/licenses/LICENSE-2.0>.
#
# [This file includes modifications made by New Vector Limited]
#
#

"""Contains constants from the specification."""

import enum
from typing import Final, TypedDict

from synapse.util.duration import Duration

# the max size of a (canonical-json-encoded) event
MAX_PDU_SIZE = 65536
# This isn't spec'ed but is our own reasonable default to play nice with Synapse's
# `max_request_size`/`max_request_body_size`. We chose the same as `MAX_PDU_SIZE` as our
# `max_request_body_size` math is currently limited by 200 `MAX_PDU_SIZE` things. The
# spec for a `/federation/v1/send` request sets the limit at 100 EDU's and 50 PDU's
# which is below that 200 `MAX_PDU_SIZE` limit (`max_request_body_size`).
#
# Allowing oversized EDU's results in failed `/federation/v1/send` transactions (because
# the request overall can overrun the `max_request_body_size`) which are retried over
# and over and prevent other outbound federation traffic from happening.
#
# We may send EDU's that are larger than this, but we aim to avoid doing so.
SOFT_MAX_EDU_SIZE = 65536

# This is the maximum size of the content of a to-device message. This is not
# (yet) spec'ed but is our own reasonable default. We need to set a limit on the
# size of to-device message contents, as they get sent over federation and
# therefore need to fit inside transactions.
#
# https://github.com/matrix-org/matrix-spec/pull/2340 tracks adding this to the
# spec.
MAX_TO_DEVICE_CONTENT_SIZE = SOFT_MAX_EDU_SIZE

# This is defined in the Matrix spec and enforced by the receiver.
MAX_EDUS_PER_TRANSACTION = 100
# A transaction can contain up to 100 EDUs but synapse reserves 10 EDUs for other purposes
# like trickling out some device list updates.
NUMBER_OF_RESERVED_EDUS_PER_TRANSACTION = 10

# The maximum allowed size of an HTTP request.
# Other than media uploads, the biggest request we expect to see is a fully-loaded
# /federation/v1/send request.
#
# The main thing in such a request is up to 50 PDUs, and up to 100 EDUs. PDUs are
# limited to 65536 bytes (possibly slightly more if the sender didn't use canonical
# json encoding); there is no specced limit to EDUs (see
# https://github.com/matrix-org/matrix-doc/issues/3121).
#
# in short, we somewhat arbitrarily limit requests to 200 * 64K (about 12.5M)
#
MAX_REQUEST_SIZE = 200 * MAX_PDU_SIZE

# Max/min size of ints in canonical JSON
CANONICALJSON_MAX_INT = (2**53) - 1
CANONICALJSON_MIN_INT = -CANONICALJSON_MAX_INT

# the "depth" field on events is limited to the same as what
# canonicaljson accepts
MAX_DEPTH = CANONICALJSON_MAX_INT

# the maximum length for a room alias is 255 characters
MAX_ALIAS_LENGTH = 255

# the maximum length for a user id is 255 characters
MAX_USERID_LENGTH = 255

# Constant value used for the pseudo-thread which is the main timeline.
MAIN_TIMELINE: Final = "main"

# MAX_INT + 1, so it always trumps any PL in canonical JSON.
CREATOR_POWER_LEVEL = 2**53


class Membership:
    """Represents the membership states of a user in a room."""

    INVITE: Final = "invite"
    JOIN: Final = "join"
    KNOCK: Final = "knock"
    LEAVE: Final = "leave"
    BAN: Final = "ban"
    LIST: Final = frozenset((INVITE, JOIN, KNOCK, LEAVE, BAN))


class PresenceState:
    """Represents the presence state of a user."""

    OFFLINE: Final = "offline"
    UNAVAILABLE: Final = "unavailable"
    ONLINE: Final = "online"
    BUSY: Final = "org.matrix.msc3026.busy"


class JoinRules:
    PUBLIC: Final = "public"
    KNOCK: Final = "knock"
    INVITE: Final = "invite"
    PRIVATE: Final = "private"
    # As defined for MSC3083.
    RESTRICTED: Final = "restricted"
    # As defined for MSC3787.
    KNOCK_RESTRICTED: Final = "knock_restricted"


class RestrictedJoinRuleTypes:
    """Understood types for the allow rules in restricted join rules."""

    ROOM_MEMBERSHIP: Final = "m.room_membership"


class LoginType:
    PASSWORD: Final = "m.login.password"
    EMAIL_IDENTITY: Final = "m.login.email.identity"
    MSISDN: Final = "m.login.msisdn"
    RECAPTCHA: Final = "m.login.recaptcha"
    TERMS: Final = "m.login.terms"
    SSO: Final = "m.login.sso"
    DUMMY: Final = "m.login.dummy"
    REGISTRATION_TOKEN: Final = "m.login.registration_token"


# This is used in the `type` parameter for /register when called by
# an appservice to register a new user.
APP_SERVICE_REGISTRATION_TYPE: Final = "m.login.application_service"


class EventTypes:
    Member: Final = "m.room.member"
    Create: Final = "m.room.create"
    Tombstone: Final = "m.room.tombstone"
    JoinRules: Final = "m.room.join_rules"
    PowerLevels: Final = "m.room.power_levels"
    Aliases: Final = "m.room.aliases"
    Redaction: Final = "m.room.redaction"
    ThirdPartyInvite: Final = "m.room.third_party_invite"

    RoomHistoryVisibility: Final = "m.room.history_visibility"
    CanonicalAlias: Final = "m.room.canonical_alias"
    Encrypted: Final = "m.room.encrypted"
    RoomAvatar: Final = "m.room.avatar"
    RoomEncryption: Final = "m.room.encryption"
    GuestAccess: Final = "m.room.guest_access"

    # These are used for validation
    Message: Final = "m.room.message"
    Topic: Final = "m.room.topic"
    Name: Final = "m.room.name"

    ServerACL: Final = "m.room.server_acl"
    Pinned: Final = "m.room.pinned_events"

    Retention: Final = "m.room.retention"

    Dummy: Final = "org.matrix.dummy_event"

    SpaceChild: Final = "m.space.child"
    SpaceParent: Final = "m.space.parent"

    Reaction: Final = "m.reaction"
    Sticker: Final = "m.sticker"
    LiveLocationShareStart: Final = "m.beacon_info"

    CallInvite: Final = "m.call.invite"

    PollStart: Final = "m.poll.start"

    RoomPolicy: Final = "m.room.policy"


class ToDeviceEventTypes:
    RoomKeyRequest: Final = "m.room_key_request"


class DeviceKeyAlgorithms:
    """Spec'd algorithms for the generation of per-device keys"""

    ED25519: Final = "ed25519"
    CURVE25519: Final = "curve25519"
    SIGNED_CURVE25519: Final = "signed_curve25519"


class EduTypes:
    PRESENCE: Final = "m.presence"
    TYPING: Final = "m.typing"
    RECEIPT: Final = "m.receipt"
    DEVICE_LIST_UPDATE: Final = "m.device_list_update"
    SIGNING_KEY_UPDATE: Final = "m.signing_key_update"
    UNSTABLE_SIGNING_KEY_UPDATE: Final = "org.matrix.signing_key_update"
    DIRECT_TO_DEVICE: Final = "m.direct_to_device"


class RejectedReason:
    AUTH_ERROR: Final = "auth_error"
    OVERSIZED_EVENT: Final = "oversized_event"


class RoomCreationPreset:
    PRIVATE_CHAT: Final = "private_chat"
    PUBLIC_CHAT: Final = "public_chat"
    TRUSTED_PRIVATE_CHAT: Final = "trusted_private_chat"


class ThirdPartyEntityKind:
    USER: Final = "user"
    LOCATION: Final = "location"


ServerNoticeMsgType: Final = "m.server_notice"
ServerNoticeLimitReached: Final = "m.server_notice.usage_limit_reached"


class UserTypes:
    """Allows for user type specific behaviour. With the benefit of hindsight
    'admin' and 'guest' users should also be UserTypes. Extra user types can be
    added in the configuration. Normal users are type None or one of the extra
    user types (if configured).
    """

    SUPPORT: Final = "support"
    BOT: Final = "bot"
    ALL_BUILTIN_USER_TYPES: Final = (SUPPORT, BOT)
    """
    The user types that are built-in to Synapse. Extra user types can be
    added in the configuration.
    """


class RelationTypes:
    """The types of relations known to this server."""

    ANNOTATION: Final = "m.annotation"
    REPLACE: Final = "m.replace"
    REFERENCE: Final = "m.reference"
    THREAD: Final = "m.thread"


class LimitBlockingTypes:
    """Reasons that a server may be blocked"""

    MONTHLY_ACTIVE_USER: Final = "monthly_active_user"
    HS_DISABLED: Final = "hs_disabled"


class EventContentFields:
    """Fields found in events' content, regardless of type."""

    # Labels for the event, cf https://github.com/matrix-org/matrix-doc/pull/2326
    LABELS: Final = "org.matrix.labels"

    # Timestamp to delete the event after
    # cf https://github.com/matrix-org/matrix-doc/pull/2228
    SELF_DESTRUCT_AFTER: Final = "org.matrix.self_destruct_after"

    # cf https://github.com/matrix-org/matrix-doc/pull/1772
    ROOM_TYPE: Final = "type"

    # Whether a room can federate.
    FEDERATE: Final = "m.federate"

    # The creator of the room, as used in `m.room.create` events.
    #
    # This is deprecated in MSC2175.
    ROOM_CREATOR: Final = "creator"
    # MSC4289
    ADDITIONAL_CREATORS: Final = "additional_creators"

    # The version of the room for `m.room.create` events.
    ROOM_VERSION: Final = "room_version"

    ROOM_NAME: Final = "name"

    MEMBERSHIP: Final = "membership"
    MEMBERSHIP_DISPLAYNAME: Final = "displayname"
    MEMBERSHIP_AVATAR_URL: Final = "avatar_url"

    # Used in m.room.guest_access events.
    GUEST_ACCESS: Final = "guest_access"

    # The authorising user for joining a restricted room.
    AUTHORISING_USER: Final = "join_authorised_via_users_server"

    # Use for mentioning users.
    MENTIONS: Final = "m.mentions"

    # an unspecced field added to to-device messages to identify them uniquely-ish
    TO_DEVICE_MSGID: Final = "org.matrix.msgid"

    # `m.room.encryption`` algorithm field
    ENCRYPTION_ALGORITHM: Final = "algorithm"

    TOMBSTONE_SUCCESSOR_ROOM: Final = "replacement_room"

    # Used in m.room.topic events.
    TOPIC: Final = "topic"
    M_TOPIC: Final = "m.topic"
    M_TEXT: Final = "m.text"


class EventUnsignedContentFields:
    """Fields found inside the 'unsigned' data on events"""

    # Requesting user's membership, per MSC4115
    MEMBERSHIP: Final = "membership"

    STICKY_TTL: Final = "msc4354_sticky_duration_ttl_ms"


class MTextFields:
    """Fields found inside m.text content blocks."""

    BODY: Final = "body"
    MIMETYPE: Final = "mimetype"


class RoomTypes:
    """Understood values of the room_type field of m.room.create events."""

    SPACE: Final = "m.space"


class RoomEncryptionAlgorithms:
    MEGOLM_V1_AES_SHA2: Final = "m.megolm.v1.aes-sha2"
    DEFAULT: Final = MEGOLM_V1_AES_SHA2


class AccountDataTypes:
    DIRECT: Final = "m.direct"
    IGNORED_USER_LIST: Final = "m.ignored_user_list"
    TAG: Final = "m.tag"
    PUSH_RULES: Final = "m.push_rules"
    # MSC4155: Invite filtering
    MSC4155_INVITE_PERMISSION_CONFIG: Final = (
        "org.matrix.msc4155.invite_permission_config"
    )
    # MSC4380: Invite blocking
    INVITE_PERMISSION_CONFIG: Final = "m.invite_permission_config"
    # Synapse-specific behaviour. See "Client-Server API Extensions" documentation
    # in Admin API for more information.
    SYNAPSE_ADMIN_CLIENT_CONFIG: Final = "io.element.synapse.admin_client_config"


class HistoryVisibility:
    INVITED: Final = "invited"
    JOINED: Final = "joined"
    SHARED: Final = "shared"
    WORLD_READABLE: Final = "world_readable"


class GuestAccess:
    CAN_JOIN: Final = "can_join"
    # anything that is not "can_join" is considered "forbidden", but for completeness:
    FORBIDDEN: Final = "forbidden"


class ReceiptTypes:
    READ: Final = "m.read"
    READ_PRIVATE: Final = "m.read.private"
    FULLY_READ: Final = "m.fully_read"


class PublicRoomsFilterFields:
    """Fields in the search filter for `/publicRooms` that we understand.

    As defined in https://spec.matrix.org/v1.3/client-server-api/#post_matrixclientv3publicrooms
    """

    GENERIC_SEARCH_TERM: Final = "generic_search_term"
    ROOM_TYPES: Final = "room_types"


class ApprovalNoticeMedium:
    """Identifier for the medium this server will use to serve notice of approval for a
    specific user's registration.

    As defined in https://github.com/matrix-org/matrix-spec-proposals/blob/babolivier/m_not_approved/proposals/3866-user-not-approved-error.md
    """

    NONE = "org.matrix.msc3866.none"
    EMAIL = "org.matrix.msc3866.email"


class Direction(enum.Enum):
    BACKWARDS = "b"
    FORWARDS = "f"


class ProfileFields:
    DISPLAYNAME: Final = "displayname"
    AVATAR_URL: Final = "avatar_url"


class ProfileUpdateAction(str, enum.Enum):
    """
    Enum representing the action of a row in the profile updates stream tables.
    The action determines whether a profile field update has occurred, or whether
    something else has happened that the sync code should know about, for example
    a user joining or leaving a room.
    """

    JOINED_ROOM = "joined_room"
    """
    This profile update row action represents a user joining a room.

    When gathering an incremental sync non-lazy response for profile updates,
    we always include the full profile of users who have joined a room the syncing
    user is a member of, where full profile means all the current profile values the
    client asked for, regardless of whether they have changed recently. This ensures
    that clients have profiles re-populated for any users who have recently left
    shared rooms.

    A scenario example would be as follows:

        * Alice leaves a room with Bob
        * Bob's client clears all profile fields from Alice
        * Alice joins a room with Bob
        * Bob's client does an incremental non-lazy sync

    At the end of the flow Bob should receive all the profile fields the client
    is interested in, not just the potential diff, which non-lazy incremental sync
    normally includes. This update action currently has no meaning for sync responses
    that are not incremental and non-lazy.
    """

    LEFT_ROOM = "left_room"
    """
    This profile update row action represents a user leaving a room.

    Clients will want to know when they no longer share rooms with a user. This
    profile action row allows the sync code to deliver a `null` response for those
    profiles, so clients can clear their cache containing the users profile data
    they are no longer interested in.
    """

    UPDATE = "update"
    """
    This profile update row action represents a user updating a profile field.

    Depending on the type of sync (initial/incremental, lazy/non-lazy), either the
    diff of profile field updates or all the current profile fields are included
    in the sync response. In the latter case the profile update action row signifies
    a change, but the client may still get fields that have not changed.
    """

    # FIXME: add a test covering adding these to the streams tables
    DELETE = "delete"
    """
    This profile update row action represents a user deleting a profile field.

    In the sync response deleted fields are indicated separately from updated fields,
    as `None` is a valid value for a field.

    Note that even though deleting displaynames and avatar_url's is done by setting
    them to an empty string, for consistency the profile update stream gets a DELETE
    action written to it, as the profile updates sync MSC's don't special case
    displayname or avatar_url.
    """


class StickyEventField(TypedDict):
    """
    Dict content of the `sticky` part of an event.
    """

    duration_ms: int


class StickyEvent:
    QUERY_PARAM_NAME: Final = "org.matrix.msc4354.sticky_duration_ms"
    """
    Query parameter used by clients for setting the sticky duration of an event they are sending.

    Applies to:
        - /rooms/.../send/...
        - /rooms/.../state/...
    """

    EVENT_FIELD_NAME: Final = "msc4354_sticky"
    """
    Name of the field in the top-level event dict that contains the sticky event dict.
    """

    MAX_DURATION: Duration = Duration(hours=1)
    """
    Maximum stickiness duration as specified in MSC4354.
    Ensures that data in the /sync response can go down and not grow unbounded.
    """

    MAX_EVENTS_IN_SYNC: Final = 100
    """
    Maximum number of sticky events to include in /sync.

    This is the default specified in the MSC. Chosen arbitrarily.
    """