Merge pull request #4019 from matrix-org/dbkr/e2e_backups

E2E backups
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David Baker 2018-10-15 10:19:43 +01:00 committed by GitHub
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changelog.d/4019.feature Normal file
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@ -0,0 +1 @@
Add support for end-to-end key backup (MSC1687)

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@ -59,6 +59,7 @@ class Codes(object):
RESOURCE_LIMIT_EXCEEDED = "M_RESOURCE_LIMIT_EXCEEDED" RESOURCE_LIMIT_EXCEEDED = "M_RESOURCE_LIMIT_EXCEEDED"
UNSUPPORTED_ROOM_VERSION = "M_UNSUPPORTED_ROOM_VERSION" UNSUPPORTED_ROOM_VERSION = "M_UNSUPPORTED_ROOM_VERSION"
INCOMPATIBLE_ROOM_VERSION = "M_INCOMPATIBLE_ROOM_VERSION" INCOMPATIBLE_ROOM_VERSION = "M_INCOMPATIBLE_ROOM_VERSION"
WRONG_ROOM_KEYS_VERSION = "M_WRONG_ROOM_KEYS_VERSION"
class CodeMessageException(RuntimeError): class CodeMessageException(RuntimeError):
@ -312,6 +313,20 @@ class LimitExceededError(SynapseError):
) )
class RoomKeysVersionError(SynapseError):
"""A client has tried to upload to a non-current version of the room_keys store
"""
def __init__(self, current_version):
"""
Args:
current_version (str): the current version of the store they should have used
"""
super(RoomKeysVersionError, self).__init__(
403, "Wrong room_keys version", Codes.WRONG_ROOM_KEYS_VERSION
)
self.current_version = current_version
class IncompatibleRoomVersionError(SynapseError): class IncompatibleRoomVersionError(SynapseError):
"""A server is trying to join a room whose version it does not support.""" """A server is trying to join a room whose version it does not support."""

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@ -0,0 +1,289 @@
# -*- coding: utf-8 -*-
# Copyright 2017, 2018 New Vector 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.
import logging
from six import iteritems
from twisted.internet import defer
from synapse.api.errors import RoomKeysVersionError, StoreError, SynapseError
from synapse.util.async_helpers import Linearizer
logger = logging.getLogger(__name__)
class E2eRoomKeysHandler(object):
"""
Implements an optional realtime backup mechanism for encrypted E2E megolm room keys.
This gives a way for users to store and recover their megolm keys if they lose all
their clients. It should also extend easily to future room key mechanisms.
The actual payload of the encrypted keys is completely opaque to the handler.
"""
def __init__(self, hs):
self.store = hs.get_datastore()
# Used to lock whenever a client is uploading key data. This prevents collisions
# between clients trying to upload the details of a new session, given all
# clients belonging to a user will receive and try to upload a new session at
# roughly the same time. Also used to lock out uploads when the key is being
# changed.
self._upload_linearizer = Linearizer("upload_room_keys_lock")
@defer.inlineCallbacks
def get_room_keys(self, user_id, version, room_id=None, session_id=None):
"""Bulk get the E2E room keys for a given backup, optionally filtered to a given
room, or a given session.
See EndToEndRoomKeyStore.get_e2e_room_keys for full details.
Args:
user_id(str): the user whose keys we're getting
version(str): the version ID of the backup we're getting keys from
room_id(string): room ID to get keys for, for None to get keys for all rooms
session_id(string): session ID to get keys for, for None to get keys for all
sessions
Returns:
A deferred list of dicts giving the session_data and message metadata for
these room keys.
"""
# we deliberately take the lock to get keys so that changing the version
# works atomically
with (yield self._upload_linearizer.queue(user_id)):
results = yield self.store.get_e2e_room_keys(
user_id, version, room_id, session_id
)
if results['rooms'] == {}:
raise SynapseError(404, "No room_keys found")
defer.returnValue(results)
@defer.inlineCallbacks
def delete_room_keys(self, user_id, version, room_id=None, session_id=None):
"""Bulk delete the E2E room keys for a given backup, optionally filtered to a given
room or a given session.
See EndToEndRoomKeyStore.delete_e2e_room_keys for full details.
Args:
user_id(str): the user whose backup we're deleting
version(str): the version ID of the backup we're deleting
room_id(string): room ID to delete keys for, for None to delete keys for all
rooms
session_id(string): session ID to delete keys for, for None to delete keys
for all sessions
Returns:
A deferred of the deletion transaction
"""
# lock for consistency with uploading
with (yield self._upload_linearizer.queue(user_id)):
yield self.store.delete_e2e_room_keys(user_id, version, room_id, session_id)
@defer.inlineCallbacks
def upload_room_keys(self, user_id, version, room_keys):
"""Bulk upload a list of room keys into a given backup version, asserting
that the given version is the current backup version. room_keys are merged
into the current backup as described in RoomKeysServlet.on_PUT().
Args:
user_id(str): the user whose backup we're setting
version(str): the version ID of the backup we're updating
room_keys(dict): a nested dict describing the room_keys we're setting:
{
"rooms": {
"!abc:matrix.org": {
"sessions": {
"c0ff33": {
"first_message_index": 1,
"forwarded_count": 1,
"is_verified": false,
"session_data": "SSBBTSBBIEZJU0gK"
}
}
}
}
}
Raises:
SynapseError: with code 404 if there are no versions defined
RoomKeysVersionError: if the uploaded version is not the current version
"""
# TODO: Validate the JSON to make sure it has the right keys.
# XXX: perhaps we should use a finer grained lock here?
with (yield self._upload_linearizer.queue(user_id)):
# Check that the version we're trying to upload is the current version
try:
version_info = yield self.store.get_e2e_room_keys_version_info(user_id)
except StoreError as e:
if e.code == 404:
raise SynapseError(404, "Version '%s' not found" % (version,))
else:
raise
if version_info['version'] != version:
# Check that the version we're trying to upload actually exists
try:
version_info = yield self.store.get_e2e_room_keys_version_info(
user_id, version,
)
# if we get this far, the version must exist
raise RoomKeysVersionError(current_version=version_info['version'])
except StoreError as e:
if e.code == 404:
raise SynapseError(404, "Version '%s' not found" % (version,))
else:
raise
# go through the room_keys.
# XXX: this should/could be done concurrently, given we're in a lock.
for room_id, room in iteritems(room_keys['rooms']):
for session_id, session in iteritems(room['sessions']):
yield self._upload_room_key(
user_id, version, room_id, session_id, session
)
@defer.inlineCallbacks
def _upload_room_key(self, user_id, version, room_id, session_id, room_key):
"""Upload a given room_key for a given room and session into a given
version of the backup. Merges the key with any which might already exist.
Args:
user_id(str): the user whose backup we're setting
version(str): the version ID of the backup we're updating
room_id(str): the ID of the room whose keys we're setting
session_id(str): the session whose room_key we're setting
room_key(dict): the room_key being set
"""
# get the room_key for this particular row
current_room_key = None
try:
current_room_key = yield self.store.get_e2e_room_key(
user_id, version, room_id, session_id
)
except StoreError as e:
if e.code == 404:
pass
else:
raise
if self._should_replace_room_key(current_room_key, room_key):
yield self.store.set_e2e_room_key(
user_id, version, room_id, session_id, room_key
)
@staticmethod
def _should_replace_room_key(current_room_key, room_key):
"""
Determine whether to replace a given current_room_key (if any)
with a newly uploaded room_key backup
Args:
current_room_key (dict): Optional, the current room_key dict if any
room_key (dict): The new room_key dict which may or may not be fit to
replace the current_room_key
Returns:
True if current_room_key should be replaced by room_key in the backup
"""
if current_room_key:
# spelt out with if/elifs rather than nested boolean expressions
# purely for legibility.
if room_key['is_verified'] and not current_room_key['is_verified']:
return True
elif (
room_key['first_message_index'] <
current_room_key['first_message_index']
):
return True
elif room_key['forwarded_count'] < current_room_key['forwarded_count']:
return True
else:
return False
return True
@defer.inlineCallbacks
def create_version(self, user_id, version_info):
"""Create a new backup version. This automatically becomes the new
backup version for the user's keys; previous backups will no longer be
writeable to.
Args:
user_id(str): the user whose backup version we're creating
version_info(dict): metadata about the new version being created
{
"algorithm": "m.megolm_backup.v1",
"auth_data": "dGhpcyBzaG91bGQgYWN0dWFsbHkgYmUgZW5jcnlwdGVkIGpzb24K"
}
Returns:
A deferred of a string that gives the new version number.
"""
# TODO: Validate the JSON to make sure it has the right keys.
# lock everyone out until we've switched version
with (yield self._upload_linearizer.queue(user_id)):
new_version = yield self.store.create_e2e_room_keys_version(
user_id, version_info
)
defer.returnValue(new_version)
@defer.inlineCallbacks
def get_version_info(self, user_id, version=None):
"""Get the info about a given version of the user's backup
Args:
user_id(str): the user whose current backup version we're querying
version(str): Optional; if None gives the most recent version
otherwise a historical one.
Raises:
StoreError: code 404 if the requested backup version doesn't exist
Returns:
A deferred of a info dict that gives the info about the new version.
{
"version": "1234",
"algorithm": "m.megolm_backup.v1",
"auth_data": "dGhpcyBzaG91bGQgYWN0dWFsbHkgYmUgZW5jcnlwdGVkIGpzb24K"
}
"""
with (yield self._upload_linearizer.queue(user_id)):
res = yield self.store.get_e2e_room_keys_version_info(user_id, version)
defer.returnValue(res)
@defer.inlineCallbacks
def delete_version(self, user_id, version=None):
"""Deletes a given version of the user's e2e_room_keys backup
Args:
user_id(str): the user whose current backup version we're deleting
version(str): the version id of the backup being deleted
Raises:
StoreError: code 404 if this backup version doesn't exist
"""
with (yield self._upload_linearizer.queue(user_id)):
yield self.store.delete_e2e_room_keys_version(user_id, version)

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@ -46,6 +46,7 @@ from synapse.rest.client.v2_alpha import (
receipts, receipts,
register, register,
report_event, report_event,
room_keys,
sendtodevice, sendtodevice,
sync, sync,
tags, tags,
@ -102,6 +103,7 @@ class ClientRestResource(JsonResource):
auth.register_servlets(hs, client_resource) auth.register_servlets(hs, client_resource)
receipts.register_servlets(hs, client_resource) receipts.register_servlets(hs, client_resource)
read_marker.register_servlets(hs, client_resource) read_marker.register_servlets(hs, client_resource)
room_keys.register_servlets(hs, client_resource)
keys.register_servlets(hs, client_resource) keys.register_servlets(hs, client_resource)
tokenrefresh.register_servlets(hs, client_resource) tokenrefresh.register_servlets(hs, client_resource)
tags.register_servlets(hs, client_resource) tags.register_servlets(hs, client_resource)

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@ -0,0 +1,372 @@
# -*- coding: utf-8 -*-
# Copyright 2017, 2018 New Vector 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.
import logging
from twisted.internet import defer
from synapse.api.errors import Codes, SynapseError
from synapse.http.servlet import (
RestServlet,
parse_json_object_from_request,
parse_string,
)
from ._base import client_v2_patterns
logger = logging.getLogger(__name__)
class RoomKeysServlet(RestServlet):
PATTERNS = client_v2_patterns(
"/room_keys/keys(/(?P<room_id>[^/]+))?(/(?P<session_id>[^/]+))?$"
)
def __init__(self, hs):
"""
Args:
hs (synapse.server.HomeServer): server
"""
super(RoomKeysServlet, self).__init__()
self.auth = hs.get_auth()
self.e2e_room_keys_handler = hs.get_e2e_room_keys_handler()
@defer.inlineCallbacks
def on_PUT(self, request, room_id, session_id):
"""
Uploads one or more encrypted E2E room keys for backup purposes.
room_id: the ID of the room the keys are for (optional)
session_id: the ID for the E2E room keys for the room (optional)
version: the version of the user's backup which this data is for.
the version must already have been created via the /room_keys/version API.
Each session has:
* first_message_index: a numeric index indicating the oldest message
encrypted by this session.
* forwarded_count: how many times the uploading client claims this key
has been shared (forwarded)
* is_verified: whether the client that uploaded the keys claims they
were sent by a device which they've verified
* session_data: base64-encrypted data describing the session.
Returns 200 OK on success with body {}
Returns 403 Forbidden if the version in question is not the most recently
created version (i.e. if this is an old client trying to write to a stale backup)
Returns 404 Not Found if the version in question doesn't exist
The API is designed to be otherwise agnostic to the room_key encryption
algorithm being used. Sessions are merged with existing ones in the
backup using the heuristics:
* is_verified sessions always win over unverified sessions
* older first_message_index always win over newer sessions
* lower forwarded_count always wins over higher forwarded_count
We trust the clients not to lie and corrupt their own backups.
It also means that if your access_token is stolen, the attacker could
delete your backup.
POST /room_keys/keys/!abc:matrix.org/c0ff33?version=1 HTTP/1.1
Content-Type: application/json
{
"first_message_index": 1,
"forwarded_count": 1,
"is_verified": false,
"session_data": "SSBBTSBBIEZJU0gK"
}
Or...
POST /room_keys/keys/!abc:matrix.org?version=1 HTTP/1.1
Content-Type: application/json
{
"sessions": {
"c0ff33": {
"first_message_index": 1,
"forwarded_count": 1,
"is_verified": false,
"session_data": "SSBBTSBBIEZJU0gK"
}
}
}
Or...
POST /room_keys/keys?version=1 HTTP/1.1
Content-Type: application/json
{
"rooms": {
"!abc:matrix.org": {
"sessions": {
"c0ff33": {
"first_message_index": 1,
"forwarded_count": 1,
"is_verified": false,
"session_data": "SSBBTSBBIEZJU0gK"
}
}
}
}
}
"""
requester = yield self.auth.get_user_by_req(request, allow_guest=False)
user_id = requester.user.to_string()
body = parse_json_object_from_request(request)
version = parse_string(request, "version")
if session_id:
body = {
"sessions": {
session_id: body
}
}
if room_id:
body = {
"rooms": {
room_id: body
}
}
yield self.e2e_room_keys_handler.upload_room_keys(
user_id, version, body
)
defer.returnValue((200, {}))
@defer.inlineCallbacks
def on_GET(self, request, room_id, session_id):
"""
Retrieves one or more encrypted E2E room keys for backup purposes.
Symmetric with the PUT version of the API.
room_id: the ID of the room to retrieve the keys for (optional)
session_id: the ID for the E2E room keys to retrieve the keys for (optional)
version: the version of the user's backup which this data is for.
the version must already have been created via the /change_secret API.
Returns as follows:
GET /room_keys/keys/!abc:matrix.org/c0ff33?version=1 HTTP/1.1
{
"first_message_index": 1,
"forwarded_count": 1,
"is_verified": false,
"session_data": "SSBBTSBBIEZJU0gK"
}
Or...
GET /room_keys/keys/!abc:matrix.org?version=1 HTTP/1.1
{
"sessions": {
"c0ff33": {
"first_message_index": 1,
"forwarded_count": 1,
"is_verified": false,
"session_data": "SSBBTSBBIEZJU0gK"
}
}
}
Or...
GET /room_keys/keys?version=1 HTTP/1.1
{
"rooms": {
"!abc:matrix.org": {
"sessions": {
"c0ff33": {
"first_message_index": 1,
"forwarded_count": 1,
"is_verified": false,
"session_data": "SSBBTSBBIEZJU0gK"
}
}
}
}
}
"""
requester = yield self.auth.get_user_by_req(request, allow_guest=False)
user_id = requester.user.to_string()
version = parse_string(request, "version")
room_keys = yield self.e2e_room_keys_handler.get_room_keys(
user_id, version, room_id, session_id
)
if session_id:
room_keys = room_keys['rooms'][room_id]['sessions'][session_id]
elif room_id:
room_keys = room_keys['rooms'][room_id]
defer.returnValue((200, room_keys))
@defer.inlineCallbacks
def on_DELETE(self, request, room_id, session_id):
"""
Deletes one or more encrypted E2E room keys for a user for backup purposes.
DELETE /room_keys/keys/!abc:matrix.org/c0ff33?version=1
HTTP/1.1 200 OK
{}
room_id: the ID of the room whose keys to delete (optional)
session_id: the ID for the E2E session to delete (optional)
version: the version of the user's backup which this data is for.
the version must already have been created via the /change_secret API.
"""
requester = yield self.auth.get_user_by_req(request, allow_guest=False)
user_id = requester.user.to_string()
version = parse_string(request, "version")
yield self.e2e_room_keys_handler.delete_room_keys(
user_id, version, room_id, session_id
)
defer.returnValue((200, {}))
class RoomKeysNewVersionServlet(RestServlet):
PATTERNS = client_v2_patterns(
"/room_keys/version$"
)
def __init__(self, hs):
"""
Args:
hs (synapse.server.HomeServer): server
"""
super(RoomKeysNewVersionServlet, self).__init__()
self.auth = hs.get_auth()
self.e2e_room_keys_handler = hs.get_e2e_room_keys_handler()
@defer.inlineCallbacks
def on_POST(self, request):
"""
Create a new backup version for this user's room_keys with the given
info. The version is allocated by the server and returned to the user
in the response. This API is intended to be used whenever the user
changes the encryption key for their backups, ensuring that backups
encrypted with different keys don't collide.
It takes out an exclusive lock on this user's room_key backups, to ensure
clients only upload to the current backup.
The algorithm passed in the version info is a reverse-DNS namespaced
identifier to describe the format of the encrypted backupped keys.
The auth_data is { user_id: "user_id", nonce: <random string> }
encrypted using the algorithm and current encryption key described above.
POST /room_keys/version
Content-Type: application/json
{
"algorithm": "m.megolm_backup.v1",
"auth_data": "dGhpcyBzaG91bGQgYWN0dWFsbHkgYmUgZW5jcnlwdGVkIGpzb24K"
}
HTTP/1.1 200 OK
Content-Type: application/json
{
"version": 12345
}
"""
requester = yield self.auth.get_user_by_req(request, allow_guest=False)
user_id = requester.user.to_string()
info = parse_json_object_from_request(request)
new_version = yield self.e2e_room_keys_handler.create_version(
user_id, info
)
defer.returnValue((200, {"version": new_version}))
# we deliberately don't have a PUT /version, as these things really should
# be immutable to avoid people footgunning
class RoomKeysVersionServlet(RestServlet):
PATTERNS = client_v2_patterns(
"/room_keys/version(/(?P<version>[^/]+))?$"
)
def __init__(self, hs):
"""
Args:
hs (synapse.server.HomeServer): server
"""
super(RoomKeysVersionServlet, self).__init__()
self.auth = hs.get_auth()
self.e2e_room_keys_handler = hs.get_e2e_room_keys_handler()
@defer.inlineCallbacks
def on_GET(self, request, version):
"""
Retrieve the version information about a given version of the user's
room_keys backup. If the version part is missing, returns info about the
most current backup version (if any)
It takes out an exclusive lock on this user's room_key backups, to ensure
clients only upload to the current backup.
Returns 404 if the given version does not exist.
GET /room_keys/version/12345 HTTP/1.1
{
"version": "12345",
"algorithm": "m.megolm_backup.v1",
"auth_data": "dGhpcyBzaG91bGQgYWN0dWFsbHkgYmUgZW5jcnlwdGVkIGpzb24K"
}
"""
requester = yield self.auth.get_user_by_req(request, allow_guest=False)
user_id = requester.user.to_string()
try:
info = yield self.e2e_room_keys_handler.get_version_info(
user_id, version
)
except SynapseError as e:
if e.code == 404:
raise SynapseError(404, "No backup found", Codes.NOT_FOUND)
defer.returnValue((200, info))
@defer.inlineCallbacks
def on_DELETE(self, request, version):
"""
Delete the information about a given version of the user's
room_keys backup. If the version part is missing, deletes the most
current backup version (if any). Doesn't delete the actual room data.
DELETE /room_keys/version/12345 HTTP/1.1
HTTP/1.1 200 OK
{}
"""
if version is None:
raise SynapseError(400, "No version specified to delete", Codes.NOT_FOUND)
requester = yield self.auth.get_user_by_req(request, allow_guest=False)
user_id = requester.user.to_string()
yield self.e2e_room_keys_handler.delete_version(
user_id, version
)
defer.returnValue((200, {}))
def register_servlets(hs, http_server):
RoomKeysServlet(hs).register(http_server)
RoomKeysVersionServlet(hs).register(http_server)
RoomKeysNewVersionServlet(hs).register(http_server)

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@ -51,6 +51,7 @@ from synapse.handlers.deactivate_account import DeactivateAccountHandler
from synapse.handlers.device import DeviceHandler from synapse.handlers.device import DeviceHandler
from synapse.handlers.devicemessage import DeviceMessageHandler from synapse.handlers.devicemessage import DeviceMessageHandler
from synapse.handlers.e2e_keys import E2eKeysHandler from synapse.handlers.e2e_keys import E2eKeysHandler
from synapse.handlers.e2e_room_keys import E2eRoomKeysHandler
from synapse.handlers.events import EventHandler, EventStreamHandler from synapse.handlers.events import EventHandler, EventStreamHandler
from synapse.handlers.groups_local import GroupsLocalHandler from synapse.handlers.groups_local import GroupsLocalHandler
from synapse.handlers.initial_sync import InitialSyncHandler from synapse.handlers.initial_sync import InitialSyncHandler
@ -130,6 +131,7 @@ class HomeServer(object):
'auth_handler', 'auth_handler',
'device_handler', 'device_handler',
'e2e_keys_handler', 'e2e_keys_handler',
'e2e_room_keys_handler',
'event_handler', 'event_handler',
'event_stream_handler', 'event_stream_handler',
'initial_sync_handler', 'initial_sync_handler',
@ -299,6 +301,9 @@ class HomeServer(object):
def build_e2e_keys_handler(self): def build_e2e_keys_handler(self):
return E2eKeysHandler(self) return E2eKeysHandler(self)
def build_e2e_room_keys_handler(self):
return E2eRoomKeysHandler(self)
def build_application_service_api(self): def build_application_service_api(self):
return ApplicationServiceApi(self) return ApplicationServiceApi(self)

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@ -30,6 +30,7 @@ from .appservice import ApplicationServiceStore, ApplicationServiceTransactionSt
from .client_ips import ClientIpStore from .client_ips import ClientIpStore
from .deviceinbox import DeviceInboxStore from .deviceinbox import DeviceInboxStore
from .directory import DirectoryStore from .directory import DirectoryStore
from .e2e_room_keys import EndToEndRoomKeyStore
from .end_to_end_keys import EndToEndKeyStore from .end_to_end_keys import EndToEndKeyStore
from .engines import PostgresEngine from .engines import PostgresEngine
from .event_federation import EventFederationStore from .event_federation import EventFederationStore
@ -77,6 +78,7 @@ class DataStore(RoomMemberStore, RoomStore,
ApplicationServiceTransactionStore, ApplicationServiceTransactionStore,
ReceiptsStore, ReceiptsStore,
EndToEndKeyStore, EndToEndKeyStore,
EndToEndRoomKeyStore,
SearchStore, SearchStore,
TagsStore, TagsStore,
AccountDataStore, AccountDataStore,

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# -*- coding: utf-8 -*-
# Copyright 2017 New Vector 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.
import json
from twisted.internet import defer
from synapse.api.errors import StoreError
from ._base import SQLBaseStore
class EndToEndRoomKeyStore(SQLBaseStore):
@defer.inlineCallbacks
def get_e2e_room_key(self, user_id, version, room_id, session_id):
"""Get the encrypted E2E room key for a given session from a given
backup version of room_keys. We only store the 'best' room key for a given
session at a given time, as determined by the handler.
Args:
user_id(str): the user whose backup we're querying
version(str): the version ID of the backup for the set of keys we're querying
room_id(str): the ID of the room whose keys we're querying.
This is a bit redundant as it's implied by the session_id, but
we include for consistency with the rest of the API.
session_id(str): the session whose room_key we're querying.
Returns:
A deferred dict giving the session_data and message metadata for
this room key.
"""
row = yield self._simple_select_one(
table="e2e_room_keys",
keyvalues={
"user_id": user_id,
"version": version,
"room_id": room_id,
"session_id": session_id,
},
retcols=(
"first_message_index",
"forwarded_count",
"is_verified",
"session_data",
),
desc="get_e2e_room_key",
)
row["session_data"] = json.loads(row["session_data"])
defer.returnValue(row)
@defer.inlineCallbacks
def set_e2e_room_key(self, user_id, version, room_id, session_id, room_key):
"""Replaces or inserts the encrypted E2E room key for a given session in
a given backup
Args:
user_id(str): the user whose backup we're setting
version(str): the version ID of the backup we're updating
room_id(str): the ID of the room whose keys we're setting
session_id(str): the session whose room_key we're setting
room_key(dict): the room_key being set
Raises:
StoreError
"""
yield self._simple_upsert(
table="e2e_room_keys",
keyvalues={
"user_id": user_id,
"room_id": room_id,
"session_id": session_id,
},
values={
"version": version,
"first_message_index": room_key['first_message_index'],
"forwarded_count": room_key['forwarded_count'],
"is_verified": room_key['is_verified'],
"session_data": json.dumps(room_key['session_data']),
},
lock=False,
)
@defer.inlineCallbacks
def get_e2e_room_keys(
self, user_id, version, room_id=None, session_id=None
):
"""Bulk get the E2E room keys for a given backup, optionally filtered to a given
room, or a given session.
Args:
user_id(str): the user whose backup we're querying
version(str): the version ID of the backup for the set of keys we're querying
room_id(str): Optional. the ID of the room whose keys we're querying, if any.
If not specified, we return the keys for all the rooms in the backup.
session_id(str): Optional. the session whose room_key we're querying, if any.
If specified, we also require the room_id to be specified.
If not specified, we return all the keys in this version of
the backup (or for the specified room)
Returns:
A deferred list of dicts giving the session_data and message metadata for
these room keys.
"""
keyvalues = {
"user_id": user_id,
"version": version,
}
if room_id:
keyvalues['room_id'] = room_id
if session_id:
keyvalues['session_id'] = session_id
rows = yield self._simple_select_list(
table="e2e_room_keys",
keyvalues=keyvalues,
retcols=(
"user_id",
"room_id",
"session_id",
"first_message_index",
"forwarded_count",
"is_verified",
"session_data",
),
desc="get_e2e_room_keys",
)
sessions = {'rooms': {}}
for row in rows:
room_entry = sessions['rooms'].setdefault(row['room_id'], {"sessions": {}})
room_entry['sessions'][row['session_id']] = {
"first_message_index": row["first_message_index"],
"forwarded_count": row["forwarded_count"],
"is_verified": row["is_verified"],
"session_data": json.loads(row["session_data"]),
}
defer.returnValue(sessions)
@defer.inlineCallbacks
def delete_e2e_room_keys(
self, user_id, version, room_id=None, session_id=None
):
"""Bulk delete the E2E room keys for a given backup, optionally filtered to a given
room or a given session.
Args:
user_id(str): the user whose backup we're deleting from
version(str): the version ID of the backup for the set of keys we're deleting
room_id(str): Optional. the ID of the room whose keys we're deleting, if any.
If not specified, we delete the keys for all the rooms in the backup.
session_id(str): Optional. the session whose room_key we're querying, if any.
If specified, we also require the room_id to be specified.
If not specified, we delete all the keys in this version of
the backup (or for the specified room)
Returns:
A deferred of the deletion transaction
"""
keyvalues = {
"user_id": user_id,
"version": version,
}
if room_id:
keyvalues['room_id'] = room_id
if session_id:
keyvalues['session_id'] = session_id
yield self._simple_delete(
table="e2e_room_keys",
keyvalues=keyvalues,
desc="delete_e2e_room_keys",
)
@staticmethod
def _get_current_version(txn, user_id):
txn.execute(
"SELECT MAX(version) FROM e2e_room_keys_versions "
"WHERE user_id=? AND deleted=0",
(user_id,)
)
row = txn.fetchone()
if not row:
raise StoreError(404, 'No current backup version')
return row[0]
def get_e2e_room_keys_version_info(self, user_id, version=None):
"""Get info metadata about a version of our room_keys backup.
Args:
user_id(str): the user whose backup we're querying
version(str): Optional. the version ID of the backup we're querying about
If missing, we return the information about the current version.
Raises:
StoreError: with code 404 if there are no e2e_room_keys_versions present
Returns:
A deferred dict giving the info metadata for this backup version
"""
def _get_e2e_room_keys_version_info_txn(txn):
if version is None:
this_version = self._get_current_version(txn, user_id)
else:
this_version = version
result = self._simple_select_one_txn(
txn,
table="e2e_room_keys_versions",
keyvalues={
"user_id": user_id,
"version": this_version,
"deleted": 0,
},
retcols=(
"version",
"algorithm",
"auth_data",
),
)
result["auth_data"] = json.loads(result["auth_data"])
return result
return self.runInteraction(
"get_e2e_room_keys_version_info",
_get_e2e_room_keys_version_info_txn
)
def create_e2e_room_keys_version(self, user_id, info):
"""Atomically creates a new version of this user's e2e_room_keys store
with the given version info.
Args:
user_id(str): the user whose backup we're creating a version
info(dict): the info about the backup version to be created
Returns:
A deferred string for the newly created version ID
"""
def _create_e2e_room_keys_version_txn(txn):
txn.execute(
"SELECT MAX(version) FROM e2e_room_keys_versions WHERE user_id=?",
(user_id,)
)
current_version = txn.fetchone()[0]
if current_version is None:
current_version = '0'
new_version = str(int(current_version) + 1)
self._simple_insert_txn(
txn,
table="e2e_room_keys_versions",
values={
"user_id": user_id,
"version": new_version,
"algorithm": info["algorithm"],
"auth_data": json.dumps(info["auth_data"]),
},
)
return new_version
return self.runInteraction(
"create_e2e_room_keys_version_txn", _create_e2e_room_keys_version_txn
)
def delete_e2e_room_keys_version(self, user_id, version=None):
"""Delete a given backup version of the user's room keys.
Doesn't delete their actual key data.
Args:
user_id(str): the user whose backup version we're deleting
version(str): Optional. the version ID of the backup version we're deleting
If missing, we delete the current backup version info.
Raises:
StoreError: with code 404 if there are no e2e_room_keys_versions present,
or if the version requested doesn't exist.
"""
def _delete_e2e_room_keys_version_txn(txn):
if version is None:
this_version = self._get_current_version(txn, user_id)
else:
this_version = version
return self._simple_update_one_txn(
txn,
table="e2e_room_keys_versions",
keyvalues={
"user_id": user_id,
"version": this_version,
},
updatevalues={
"deleted": 1,
}
)
return self.runInteraction(
"delete_e2e_room_keys_version",
_delete_e2e_room_keys_version_txn
)

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/* Copyright 2017 New Vector 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.
*/
-- users' optionally backed up encrypted e2e sessions
CREATE TABLE e2e_room_keys (
user_id TEXT NOT NULL,
room_id TEXT NOT NULL,
session_id TEXT NOT NULL,
version TEXT NOT NULL,
first_message_index INT,
forwarded_count INT,
is_verified BOOLEAN,
session_data TEXT NOT NULL
);
CREATE UNIQUE INDEX e2e_room_keys_idx ON e2e_room_keys(user_id, room_id, session_id);
-- the metadata for each generation of encrypted e2e session backups
CREATE TABLE e2e_room_keys_versions (
user_id TEXT NOT NULL,
version TEXT NOT NULL,
algorithm TEXT NOT NULL,
auth_data TEXT NOT NULL,
deleted SMALLINT DEFAULT 0 NOT NULL
);
CREATE UNIQUE INDEX e2e_room_keys_versions_idx ON e2e_room_keys_versions(user_id, version);

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# -*- coding: utf-8 -*-
# Copyright 2016 OpenMarket Ltd
# Copyright 2017 New Vector 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.
import copy
import mock
from twisted.internet import defer
import synapse.api.errors
import synapse.handlers.e2e_room_keys
import synapse.storage
from synapse.api import errors
from tests import unittest, utils
# sample room_key data for use in the tests
room_keys = {
"rooms": {
"!abc:matrix.org": {
"sessions": {
"c0ff33": {
"first_message_index": 1,
"forwarded_count": 1,
"is_verified": False,
"session_data": "SSBBTSBBIEZJU0gK"
}
}
}
}
}
class E2eRoomKeysHandlerTestCase(unittest.TestCase):
def __init__(self, *args, **kwargs):
super(E2eRoomKeysHandlerTestCase, self).__init__(*args, **kwargs)
self.hs = None # type: synapse.server.HomeServer
self.handler = None # type: synapse.handlers.e2e_keys.E2eRoomKeysHandler
@defer.inlineCallbacks
def setUp(self):
self.hs = yield utils.setup_test_homeserver(
self.addCleanup,
handlers=None,
replication_layer=mock.Mock(),
)
self.handler = synapse.handlers.e2e_room_keys.E2eRoomKeysHandler(self.hs)
self.local_user = "@boris:" + self.hs.hostname
@defer.inlineCallbacks
def test_get_missing_current_version_info(self):
"""Check that we get a 404 if we ask for info about the current version
if there is no version.
"""
res = None
try:
yield self.handler.get_version_info(self.local_user)
except errors.SynapseError as e:
res = e.code
self.assertEqual(res, 404)
@defer.inlineCallbacks
def test_get_missing_version_info(self):
"""Check that we get a 404 if we ask for info about a specific version
if it doesn't exist.
"""
res = None
try:
yield self.handler.get_version_info(self.local_user, "bogus_version")
except errors.SynapseError as e:
res = e.code
self.assertEqual(res, 404)
@defer.inlineCallbacks
def test_create_version(self):
"""Check that we can create and then retrieve versions.
"""
res = yield self.handler.create_version(self.local_user, {
"algorithm": "m.megolm_backup.v1",
"auth_data": "first_version_auth_data",
})
self.assertEqual(res, "1")
# check we can retrieve it as the current version
res = yield self.handler.get_version_info(self.local_user)
self.assertDictEqual(res, {
"version": "1",
"algorithm": "m.megolm_backup.v1",
"auth_data": "first_version_auth_data",
})
# check we can retrieve it as a specific version
res = yield self.handler.get_version_info(self.local_user, "1")
self.assertDictEqual(res, {
"version": "1",
"algorithm": "m.megolm_backup.v1",
"auth_data": "first_version_auth_data",
})
# upload a new one...
res = yield self.handler.create_version(self.local_user, {
"algorithm": "m.megolm_backup.v1",
"auth_data": "second_version_auth_data",
})
self.assertEqual(res, "2")
# check we can retrieve it as the current version
res = yield self.handler.get_version_info(self.local_user)
self.assertDictEqual(res, {
"version": "2",
"algorithm": "m.megolm_backup.v1",
"auth_data": "second_version_auth_data",
})
@defer.inlineCallbacks
def test_delete_missing_version(self):
"""Check that we get a 404 on deleting nonexistent versions
"""
res = None
try:
yield self.handler.delete_version(self.local_user, "1")
except errors.SynapseError as e:
res = e.code
self.assertEqual(res, 404)
@defer.inlineCallbacks
def test_delete_missing_current_version(self):
"""Check that we get a 404 on deleting nonexistent current version
"""
res = None
try:
yield self.handler.delete_version(self.local_user)
except errors.SynapseError as e:
res = e.code
self.assertEqual(res, 404)
@defer.inlineCallbacks
def test_delete_version(self):
"""Check that we can create and then delete versions.
"""
res = yield self.handler.create_version(self.local_user, {
"algorithm": "m.megolm_backup.v1",
"auth_data": "first_version_auth_data",
})
self.assertEqual(res, "1")
# check we can delete it
yield self.handler.delete_version(self.local_user, "1")
# check that it's gone
res = None
try:
yield self.handler.get_version_info(self.local_user, "1")
except errors.SynapseError as e:
res = e.code
self.assertEqual(res, 404)
@defer.inlineCallbacks
def test_get_missing_room_keys(self):
"""Check that we get a 404 on querying missing room_keys
"""
res = None
try:
yield self.handler.get_room_keys(self.local_user, "bogus_version")
except errors.SynapseError as e:
res = e.code
self.assertEqual(res, 404)
# check we also get a 404 even if the version is valid
version = yield self.handler.create_version(self.local_user, {
"algorithm": "m.megolm_backup.v1",
"auth_data": "first_version_auth_data",
})
self.assertEqual(version, "1")
res = None
try:
yield self.handler.get_room_keys(self.local_user, version)
except errors.SynapseError as e:
res = e.code
self.assertEqual(res, 404)
# TODO: test the locking semantics when uploading room_keys,
# although this is probably best done in sytest
@defer.inlineCallbacks
def test_upload_room_keys_no_versions(self):
"""Check that we get a 404 on uploading keys when no versions are defined
"""
res = None
try:
yield self.handler.upload_room_keys(self.local_user, "no_version", room_keys)
except errors.SynapseError as e:
res = e.code
self.assertEqual(res, 404)
@defer.inlineCallbacks
def test_upload_room_keys_bogus_version(self):
"""Check that we get a 404 on uploading keys when an nonexistent version
is specified
"""
version = yield self.handler.create_version(self.local_user, {
"algorithm": "m.megolm_backup.v1",
"auth_data": "first_version_auth_data",
})
self.assertEqual(version, "1")
res = None
try:
yield self.handler.upload_room_keys(
self.local_user, "bogus_version", room_keys
)
except errors.SynapseError as e:
res = e.code
self.assertEqual(res, 404)
@defer.inlineCallbacks
def test_upload_room_keys_wrong_version(self):
"""Check that we get a 403 on uploading keys for an old version
"""
version = yield self.handler.create_version(self.local_user, {
"algorithm": "m.megolm_backup.v1",
"auth_data": "first_version_auth_data",
})
self.assertEqual(version, "1")
version = yield self.handler.create_version(self.local_user, {
"algorithm": "m.megolm_backup.v1",
"auth_data": "second_version_auth_data",
})
self.assertEqual(version, "2")
res = None
try:
yield self.handler.upload_room_keys(self.local_user, "1", room_keys)
except errors.SynapseError as e:
res = e.code
self.assertEqual(res, 403)
@defer.inlineCallbacks
def test_upload_room_keys_insert(self):
"""Check that we can insert and retrieve keys for a session
"""
version = yield self.handler.create_version(self.local_user, {
"algorithm": "m.megolm_backup.v1",
"auth_data": "first_version_auth_data",
})
self.assertEqual(version, "1")
yield self.handler.upload_room_keys(self.local_user, version, room_keys)
res = yield self.handler.get_room_keys(self.local_user, version)
self.assertDictEqual(res, room_keys)
# check getting room_keys for a given room
res = yield self.handler.get_room_keys(
self.local_user,
version,
room_id="!abc:matrix.org"
)
self.assertDictEqual(res, room_keys)
# check getting room_keys for a given session_id
res = yield self.handler.get_room_keys(
self.local_user,
version,
room_id="!abc:matrix.org",
session_id="c0ff33",
)
self.assertDictEqual(res, room_keys)
@defer.inlineCallbacks
def test_upload_room_keys_merge(self):
"""Check that we can upload a new room_key for an existing session and
have it correctly merged"""
version = yield self.handler.create_version(self.local_user, {
"algorithm": "m.megolm_backup.v1",
"auth_data": "first_version_auth_data",
})
self.assertEqual(version, "1")
yield self.handler.upload_room_keys(self.local_user, version, room_keys)
new_room_keys = copy.deepcopy(room_keys)
new_room_key = new_room_keys['rooms']['!abc:matrix.org']['sessions']['c0ff33']
# test that increasing the message_index doesn't replace the existing session
new_room_key['first_message_index'] = 2
new_room_key['session_data'] = 'new'
yield self.handler.upload_room_keys(self.local_user, version, new_room_keys)
res = yield self.handler.get_room_keys(self.local_user, version)
self.assertEqual(
res['rooms']['!abc:matrix.org']['sessions']['c0ff33']['session_data'],
"SSBBTSBBIEZJU0gK"
)
# test that marking the session as verified however /does/ replace it
new_room_key['is_verified'] = True
yield self.handler.upload_room_keys(self.local_user, version, new_room_keys)
res = yield self.handler.get_room_keys(self.local_user, version)
self.assertEqual(
res['rooms']['!abc:matrix.org']['sessions']['c0ff33']['session_data'],
"new"
)
# test that a session with a higher forwarded_count doesn't replace one
# with a lower forwarding count
new_room_key['forwarded_count'] = 2
new_room_key['session_data'] = 'other'
yield self.handler.upload_room_keys(self.local_user, version, new_room_keys)
res = yield self.handler.get_room_keys(self.local_user, version)
self.assertEqual(
res['rooms']['!abc:matrix.org']['sessions']['c0ff33']['session_data'],
"new"
)
# TODO: check edge cases as well as the common variations here
@defer.inlineCallbacks
def test_delete_room_keys(self):
"""Check that we can insert and delete keys for a session
"""
version = yield self.handler.create_version(self.local_user, {
"algorithm": "m.megolm_backup.v1",
"auth_data": "first_version_auth_data",
})
self.assertEqual(version, "1")
# check for bulk-delete
yield self.handler.upload_room_keys(self.local_user, version, room_keys)
yield self.handler.delete_room_keys(self.local_user, version)
res = None
try:
yield self.handler.get_room_keys(
self.local_user,
version,
room_id="!abc:matrix.org",
session_id="c0ff33",
)
except errors.SynapseError as e:
res = e.code
self.assertEqual(res, 404)
# check for bulk-delete per room
yield self.handler.upload_room_keys(self.local_user, version, room_keys)
yield self.handler.delete_room_keys(
self.local_user,
version,
room_id="!abc:matrix.org",
)
res = None
try:
yield self.handler.get_room_keys(
self.local_user,
version,
room_id="!abc:matrix.org",
session_id="c0ff33",
)
except errors.SynapseError as e:
res = e.code
self.assertEqual(res, 404)
# check for bulk-delete per session
yield self.handler.upload_room_keys(self.local_user, version, room_keys)
yield self.handler.delete_room_keys(
self.local_user,
version,
room_id="!abc:matrix.org",
session_id="c0ff33",
)
res = None
try:
yield self.handler.get_room_keys(
self.local_user,
version,
room_id="!abc:matrix.org",
session_id="c0ff33",
)
except errors.SynapseError as e:
res = e.code
self.assertEqual(res, 404)