delete keys when deleting backups

synapse/storage/data_stores/main/e2e_room_keys.py

@@ -321,9 +321,17 @@ class EndToEndRoomKeyStore(SQLBaseStore):
         def _delete_e2e_room_keys_version_txn(txn):
             if version is None:
                 this_version = self._get_current_version(txn, user_id)
+                if this_version is None:
+                    raise StoreError(404, "No current backup version")
             else:
                 this_version = version
 
+            self._simple_delete_txn(
+                txn,
+                table="e2e_room_keys",
+                keyvalues={"user_id": user_id, "version": this_version},
+            )
+
             return self._simple_update_one_txn(
                 txn,
                 table="e2e_room_keys_versions",

synapse/storage/data_stores/main/schema/delta/56/delete_keys_from_deleted_backups.sql

@@ -0,0 +1,25 @@
+/* Copyright 2019 The Matrix.org Foundation C.I.C
+ *
+ * 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.
+ */
+
+/* delete room keys that belong to deleted room key version, or to room key
+ * versions that don't exist (anymore)
+ */
+DELETE FROM e2e_room_keys
+WHERE version NOT IN (
+  SELECT version
+  FROM e2e_room_keys_versions
+  WHERE e2e_room_keys.user_id = e2e_room_keys_versions.user_id
+  AND e2e_room_keys_versions.deleted = 0
+);