Remove backing code for groups/communities (#12558)

Including handlers, configuration code, appservice support, and
the GroupID construct.

1 files changed, 0 insertions, 218 deletions

diff --git a/synapse/groups/attestations.py b/synapse/groups/attestations.py
deleted file mode 100644
index ed26d6a6ce..0000000000
--- a/synapse/groups/attestations.py
+++ /dev/null
@@ -1,218 +0,0 @@
-# Copyright 2017 Vector Creations Ltd
-#
-# Licensed under the Apache License, Version 2.0 (the "License");
-# you may not use this file except in compliance with the License.
-# You may obtain a copy of the License at
-#
-#     http://www.apache.org/licenses/LICENSE-2.0
-#
-# Unless required by applicable law or agreed to in writing, software
-# distributed under the License is distributed on an "AS IS" BASIS,
-# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-# See the License for the specific language governing permissions and
-# limitations under the License.
-
-"""Attestations ensure that users and groups can't lie about their memberships.
-
-When a user joins a group the HS and GS swap attestations, which allow them
-both to independently prove to third parties their membership.These
-attestations have a validity period so need to be periodically renewed.
-
-If a user leaves (or gets kicked out of) a group, either side can still use
-their attestation to "prove" their membership, until the attestation expires.
-Therefore attestations shouldn't be relied on to prove membership in important
-cases, but can for less important situations, e.g. showing a users membership
-of groups on their profile, showing flairs, etc.
-
-An attestation is a signed blob of json that looks like:
-
-    {
-        "user_id": "@foo:a.example.com",
-        "group_id": "+bar:b.example.com",
-        "valid_until_ms": 1507994728530,
-        "signatures":{"matrix.org":{"ed25519:auto":"..."}}
-    }
-"""
-
-import logging
-import random
-from typing import TYPE_CHECKING, Optional, Tuple
-
-from signedjson.sign import sign_json
-
-from twisted.internet.defer import Deferred
-
-from synapse.api.errors import HttpResponseException, RequestSendFailed, SynapseError
-from synapse.metrics.background_process_metrics import run_as_background_process
-from synapse.types import JsonDict, get_domain_from_id
-
-if TYPE_CHECKING:
-    from synapse.server import HomeServer
-
-logger = logging.getLogger(__name__)
-
-
-# Default validity duration for new attestations we create
-DEFAULT_ATTESTATION_LENGTH_MS = 3 * 24 * 60 * 60 * 1000
-
-# We add some jitter to the validity duration of attestations so that if we
-# add lots of users at once we don't need to renew them all at once.
-# The jitter is a multiplier picked randomly between the first and second number
-DEFAULT_ATTESTATION_JITTER = (0.9, 1.3)
-
-# Start trying to update our attestations when they come this close to expiring
-UPDATE_ATTESTATION_TIME_MS = 1 * 24 * 60 * 60 * 1000
-
-
-class GroupAttestationSigning:
-    """Creates and verifies group attestations."""
-
-    def __init__(self, hs: "HomeServer"):
-        self.keyring = hs.get_keyring()
-        self.clock = hs.get_clock()
-        self.server_name = hs.hostname
-        self.signing_key = hs.signing_key
-
-    async def verify_attestation(
-        self,
-        attestation: JsonDict,
-        group_id: str,
-        user_id: str,
-        server_name: Optional[str] = None,
-    ) -> None:
-        """Verifies that the given attestation matches the given parameters.
-
-        An optional server_name can be supplied to explicitly set which server's
-        signature is expected. Otherwise assumes that either the group_id or user_id
-        is local and uses the other's server as the one to check.
-        """
-
-        if not server_name:
-            if get_domain_from_id(group_id) == self.server_name:
-                server_name = get_domain_from_id(user_id)
-            elif get_domain_from_id(user_id) == self.server_name:
-                server_name = get_domain_from_id(group_id)
-            else:
-                raise Exception("Expected either group_id or user_id to be local")
-
-        if user_id != attestation["user_id"]:
-            raise SynapseError(400, "Attestation has incorrect user_id")
-
-        if group_id != attestation["group_id"]:
-            raise SynapseError(400, "Attestation has incorrect group_id")
-        valid_until_ms = attestation["valid_until_ms"]
-
-        # TODO: We also want to check that *new* attestations that people give
-        # us to store are valid for at least a little while.
-        now = self.clock.time_msec()
-        if valid_until_ms < now:
-            raise SynapseError(400, "Attestation expired")
-
-        assert server_name is not None
-        await self.keyring.verify_json_for_server(
-            server_name,
-            attestation,
-            now,
-        )
-
-    def create_attestation(self, group_id: str, user_id: str) -> JsonDict:
-        """Create an attestation for the group_id and user_id with default
-        validity length.
-        """
-        validity_period = DEFAULT_ATTESTATION_LENGTH_MS * random.uniform(
-            *DEFAULT_ATTESTATION_JITTER
-        )
-        valid_until_ms = int(self.clock.time_msec() + validity_period)
-
-        return sign_json(
-            {
-                "group_id": group_id,
-                "user_id": user_id,
-                "valid_until_ms": valid_until_ms,
-            },
-            self.server_name,
-            self.signing_key,
-        )
-
-
-class GroupAttestionRenewer:
-    """Responsible for sending and receiving attestation updates."""
-
-    def __init__(self, hs: "HomeServer"):
-        self.clock = hs.get_clock()
-        self.store = hs.get_datastores().main
-        self.assestations = hs.get_groups_attestation_signing()
-        self.transport_client = hs.get_federation_transport_client()
-        self.is_mine_id = hs.is_mine_id
-        self.attestations = hs.get_groups_attestation_signing()
-
-        if not hs.config.worker.worker_app:
-            self._renew_attestations_loop = self.clock.looping_call(
-                self._start_renew_attestations, 30 * 60 * 1000
-            )
-
-    async def on_renew_attestation(
-        self, group_id: str, user_id: str, content: JsonDict
-    ) -> JsonDict:
-        """When a remote updates an attestation"""
-        attestation = content["attestation"]
-
-        if not self.is_mine_id(group_id) and not self.is_mine_id(user_id):
-            raise SynapseError(400, "Neither user not group are on this server")
-
-        await self.attestations.verify_attestation(
-            attestation, user_id=user_id, group_id=group_id
-        )
-
-        await self.store.update_remote_attestion(group_id, user_id, attestation)
-
-        return {}
-
-    def _start_renew_attestations(self) -> "Deferred[None]":
-        return run_as_background_process("renew_attestations", self._renew_attestations)
-
-    async def _renew_attestations(self) -> None:
-        """Called periodically to check if we need to update any of our attestations"""
-
-        now = self.clock.time_msec()
-
-        rows = await self.store.get_attestations_need_renewals(
-            now + UPDATE_ATTESTATION_TIME_MS
-        )
-
-        async def _renew_attestation(group_user: Tuple[str, str]) -> None:
-            group_id, user_id = group_user
-            try:
-                if not self.is_mine_id(group_id):
-                    destination = get_domain_from_id(group_id)
-                elif not self.is_mine_id(user_id):
-                    destination = get_domain_from_id(user_id)
-                else:
-                    logger.warning(
-                        "Incorrectly trying to do attestations for user: %r in %r",
-                        user_id,
-                        group_id,
-                    )
-                    await self.store.remove_attestation_renewal(group_id, user_id)
-                    return
-
-                attestation = self.attestations.create_attestation(group_id, user_id)
-
-                await self.transport_client.renew_group_attestation(
-                    destination, group_id, user_id, content={"attestation": attestation}
-                )
-
-                await self.store.update_attestation_renewal(
-                    group_id, user_id, attestation
-                )
-            except (RequestSendFailed, HttpResponseException) as e:
-                logger.warning(
-                    "Failed to renew attestation of %r in %r: %s", user_id, group_id, e
-                )
-            except Exception:
-                logger.exception(
-                    "Error renewing attestation of %r in %r", user_id, group_id
-                )
-
-        for row in rows:
-            await _renew_attestation((row["group_id"], row["user_id"]))