From 14b3da63a339333292a83410c0ba3148bcb644ba Mon Sep 17 00:00:00 2001 From: Matthew Hodgson Date: Wed, 27 Dec 2017 23:37:44 +0000 Subject: [PATCH] add a tonne of docstring; make upload_room_keys properly assert version --- synapse/handlers/e2e_room_keys.py | 111 ++++++++++++++++++++-- synapse/rest/client/v2_alpha/room_keys.py | 11 ++- 2 files changed, 113 insertions(+), 9 deletions(-) diff --git a/synapse/handlers/e2e_room_keys.py b/synapse/handlers/e2e_room_keys.py index 7a940d1c21..2fa025bfc7 100644 --- a/synapse/handlers/e2e_room_keys.py +++ b/synapse/handlers/e2e_room_keys.py @@ -42,7 +42,16 @@ class E2eRoomKeysHandler(object): self._upload_linearizer = Linearizer("upload_room_keys_lock") @defer.inlineCallbacks - def get_room_keys(self, user_id, version, room_id, session_id): + 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. + + 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)): @@ -52,20 +61,56 @@ class E2eRoomKeysHandler(object): defer.returnValue(results) @defer.inlineCallbacks - def delete_room_keys(self, user_id, version, room_id, session_id): + 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. + + 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.get_version_info(user_id, version) + version_info = yield self.get_current_version_info(user_id) except StoreError as e: if e.code == 404: raise SynapseError(404, "Version '%s' not found" % (version,)) @@ -87,6 +132,17 @@ class E2eRoomKeysHandler(object): @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: @@ -138,6 +194,23 @@ class E2eRoomKeysHandler(object): @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 @@ -148,14 +221,36 @@ class E2eRoomKeysHandler(object): defer.returnValue(new_version) @defer.inlineCallbacks - def get_version_info(self, user_id, version): + def get_current_version_info(self, user_id): + """Get the user's current backup version. + + Args: + user_id(str): the user whose current backup version we're querying + Raises: + StoreError: code 404 if there is no current backup version + Returns: + A deferred of a info dict that gives the info about the new version. + + { + "algorithm": "m.megolm_backup.v1", + "auth_data": "dGhpcyBzaG91bGQgYWN0dWFsbHkgYmUgZW5jcnlwdGVkIGpzb24K" + } + """ + with (yield self._upload_linearizer.queue(user_id)): - results = yield self.store.get_e2e_room_keys_version_info( - user_id, version - ) + results = yield self.store.get_e2e_room_keys_version_info(user_id) defer.returnValue(results) @defer.inlineCallbacks def delete_version(self, user_id, version): + """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) diff --git a/synapse/rest/client/v2_alpha/room_keys.py b/synapse/rest/client/v2_alpha/room_keys.py index 04547c7d43..d3f857aba2 100644 --- a/synapse/rest/client/v2_alpha/room_keys.py +++ b/synapse/rest/client/v2_alpha/room_keys.py @@ -47,7 +47,7 @@ class RoomKeysServlet(RestServlet): 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 /change_secret API. + 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 @@ -59,6 +59,9 @@ class RoomKeysServlet(RestServlet): * 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 @@ -251,6 +254,9 @@ class RoomKeysVersionServlet(RestServlet): 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. @@ -292,6 +298,9 @@ class RoomKeysVersionServlet(RestServlet): Retrieve the version information about a given version of the user's room_keys backup. + It takes out an exclusive lock on this user's room_key backups, to ensure + clients only upload to the current backup. + GET /room_keys/version/12345 HTTP/1.1 { "algorithm": "m.megolm_backup.v1",