Merge pull request #2292 from matrix-org/erikj/quarantine_media

Add API to quarantine media

7 files changed, 121 insertions, 5 deletions

diff --git a/synapse/rest/client/v1/admin.py b/synapse/rest/client/v1/admin.py
index aaa3dffb1b..7d786e8de3 100644
--- a/synapse/rest/client/v1/admin.py
+++ b/synapse/rest/client/v1/admin.py
@@ -270,6 +270,30 @@ class ShutdownRoomRestServlet(ClientV1RestServlet):
         }))
 
 
+class QuarantineMediaInRoom(ClientV1RestServlet):
+    """Quarantines all media in a room so that no one can download it via
+    this server.
+    """
+    PATTERNS = client_path_patterns("/admin/quarantine_media/(?P<room_id>[^/]+)")
+
+    def __init__(self, hs):
+        super(QuarantineMediaInRoom, self).__init__(hs)
+        self.store = hs.get_datastore()
+
+    @defer.inlineCallbacks
+    def on_POST(self, request, room_id):
+        requester = yield self.auth.get_user_by_req(request)
+        is_admin = yield self.auth.is_server_admin(requester.user)
+        if not is_admin:
+            raise AuthError(403, "You are not a server admin")
+
+        num_quarantined = yield self.store.quarantine_media_ids_in_room(
+            room_id, requester.user.to_string(),
+        )
+
+        defer.returnValue((200, {"num_quarantined": num_quarantined}))
+
+
 class ResetPasswordRestServlet(ClientV1RestServlet):
     """Post request to allow an administrator reset password for a user.
     This need a user have a administrator access in Synapse.
@@ -467,3 +491,4 @@ def register_servlets(hs, http_server):
     GetUsersPaginatedRestServlet(hs).register(http_server)
     SearchUsersRestServlet(hs).register(http_server)
     ShutdownRoomRestServlet(hs).register(http_server)
+    QuarantineMediaInRoom(hs).register(http_server)
diff --git a/synapse/rest/media/v1/download_resource.py b/synapse/rest/media/v1/download_resource.py
index 6788375e85..39a286b83c 100644
--- a/synapse/rest/media/v1/download_resource.py
+++ b/synapse/rest/media/v1/download_resource.py
@@ -66,7 +66,7 @@ class DownloadResource(Resource):
     @defer.inlineCallbacks
     def _respond_local_file(self, request, media_id, name):
         media_info = yield self.store.get_local_media(media_id)
-        if not media_info:
+        if not media_info or media_info["quarantined_by"]:
             respond_404(request)
             return
 
diff --git a/synapse/rest/media/v1/media_repository.py b/synapse/rest/media/v1/media_repository.py
index bae2b4c757..0718f75241 100644
--- a/synapse/rest/media/v1/media_repository.py
+++ b/synapse/rest/media/v1/media_repository.py
@@ -135,6 +135,8 @@ class MediaRepository(object):
             media_info = yield self._download_remote_file(
                 server_name, media_id
             )
+        elif media_info["quarantined_by"]:
+            raise NotFoundError()
         else:
             self.recently_accessed_remotes.add((server_name, media_id))
             yield self.store.update_cached_last_access_time(
diff --git a/synapse/rest/media/v1/thumbnail_resource.py b/synapse/rest/media/v1/thumbnail_resource.py
index d8f54adc99..59b2c39b2f 100644
--- a/synapse/rest/media/v1/thumbnail_resource.py
+++ b/synapse/rest/media/v1/thumbnail_resource.py
@@ -81,7 +81,7 @@ class ThumbnailResource(Resource):
                                  method, m_type):
         media_info = yield self.store.get_local_media(media_id)
 
-        if not media_info:
+        if not media_info or media_info["quarantined_by"]:
             respond_404(request)
             return
 
@@ -117,7 +117,7 @@ class ThumbnailResource(Resource):
                                             desired_type):
         media_info = yield self.store.get_local_media(media_id)
 
-        if not media_info:
+        if not media_info or media_info["quarantined_by"]:
             respond_404(request)
             return
 
diff --git a/synapse/storage/media_repository.py b/synapse/storage/media_repository.py
index 4c0f82353d..5f0f18ee66 100644
--- a/synapse/storage/media_repository.py
+++ b/synapse/storage/media_repository.py
@@ -30,7 +30,7 @@ class MediaRepositoryStore(SQLBaseStore):
         return self._simple_select_one(
             "local_media_repository",
             {"media_id": media_id},
-            ("media_type", "media_length", "upload_name", "created_ts"),
+            ("media_type", "media_length", "upload_name", "created_ts", "quarantined_by"),
             allow_none=True,
             desc="get_local_media",
         )
@@ -138,7 +138,7 @@ class MediaRepositoryStore(SQLBaseStore):
             {"media_origin": origin, "media_id": media_id},
             (
                 "media_type", "media_length", "upload_name", "created_ts",
-                "filesystem_id",
+                "filesystem_id", "quarantined_by",
             ),
             allow_none=True,
             desc="get_cached_remote_media",
diff --git a/synapse/storage/room.py b/synapse/storage/room.py
index 07366f66b6..23688430b7 100644
--- a/synapse/storage/room.py
+++ b/synapse/storage/room.py
@@ -24,6 +24,7 @@ from .engines import PostgresEngine, Sqlite3Engine
 import collections
 import logging
 import ujson as json
+import re
 
 logger = logging.getLogger(__name__)
 
@@ -531,3 +532,74 @@ class RoomStore(SQLBaseStore):
             desc="block_room",
         )
         self.is_room_blocked.invalidate((room_id,))
+
+    def quarantine_media_ids_in_room(self, room_id, quarantined_by):
+        """For a room loops through all events with media and quarantines
+        the associated media
+        """
+        def _get_media_ids_in_room(txn):
+            mxc_re = re.compile("^mxc://([^/]+)/([^/#?]+)")
+
+            next_token = self.get_current_events_token() + 1
+
+            total_media_quarantined = 0
+
+            while next_token:
+                sql = """
+                    SELECT stream_ordering, content FROM events
+                    WHERE room_id = ?
+                        AND stream_ordering < ?
+                        AND contains_url = ? AND outlier = ?
+                    ORDER BY stream_ordering DESC
+                    LIMIT ?
+                """
+                txn.execute(sql, (room_id, next_token, True, False, 100))
+
+                next_token = None
+                local_media_mxcs = []
+                remote_media_mxcs = []
+                for stream_ordering, content_json in txn:
+                    next_token = stream_ordering
+                    content = json.loads(content_json)
+
+                    content_url = content.get("url")
+                    thumbnail_url = content.get("info", {}).get("thumbnail_url")
+
+                    for url in (content_url, thumbnail_url):
+                        if not url:
+                            continue
+                        matches = mxc_re.match(url)
+                        if matches:
+                            hostname = matches.group(1)
+                            media_id = matches.group(2)
+                            if hostname == self.hostname:
+                                local_media_mxcs.append(media_id)
+                            else:
+                                remote_media_mxcs.append((hostname, media_id))
+
+                # Now update all the tables to set the quarantined_by flag
+
+                txn.executemany("""
+                    UPDATE local_media_repository
+                    SET quarantined_by = ?
+                    WHERE media_id = ?
+                """, ((quarantined_by, media_id) for media_id in local_media_mxcs))
+
+                txn.executemany(
+                    """
+                        UPDATE remote_media_cache
+                        SET quarantined_by = ?
+                        WHERE media_origin AND media_id = ?
+                    """,
+                    (
+                        (quarantined_by, origin, media_id)
+                        for origin, media_id in remote_media_mxcs
+                    )
+                )
+
+                total_media_quarantined += len(local_media_mxcs)
+                total_media_quarantined += len(remote_media_mxcs)
+
+            return total_media_quarantined
+
+        return self.runInteraction("get_media_ids_in_room", _get_media_ids_in_room)
diff --git a/synapse/storage/schema/delta/43/quarantine_media.sql b/synapse/storage/schema/delta/43/quarantine_media.sql
new file mode 100644
index 0000000000..630907ec4f
--- /dev/null
+++ b/synapse/storage/schema/delta/43/quarantine_media.sql
@@ -0,0 +1,17 @@
+/* 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.
+ */
+
+ALTER TABLE local_media_repository ADD COLUMN quarantined_by TEXT;
+ALTER TABLE remote_media_cache ADD COLUMN quarantined_by TEXT;