1 files changed, 24 insertions, 1 deletions
diff --git a/synapse/api/errors.py b/synapse/api/errors.py
index 2e7f98404d..4124469442 100644
--- a/synapse/api/errors.py
+++ b/synapse/api/errors.py
@@ -59,6 +59,7 @@ class Codes(object):
     RESOURCE_LIMIT_EXCEEDED = "M_RESOURCE_LIMIT_EXCEEDED"
     UNSUPPORTED_ROOM_VERSION = "M_UNSUPPORTED_ROOM_VERSION"
     INCOMPATIBLE_ROOM_VERSION = "M_INCOMPATIBLE_ROOM_VERSION"
+    WRONG_ROOM_KEYS_VERSION = "M_WRONG_ROOM_KEYS_VERSION"
 
 
 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):
     """A server is trying to join a room whose version it does not support."""
 
@@ -329,10 +344,18 @@ class IncompatibleRoomVersionError(SynapseError):
         return cs_error(
             self.msg,
             self.errcode,
-            room_version=self._room_version,
+            room_version=self.current_version,
         )
 
 
+def cs_exception(exception):
+    if isinstance(exception, CodeMessageException):
+        return exception.error_dict()
+    else:
+        logger.error("Unknown exception type: %s", type(exception))
+        return {}
+
+
 def cs_error(msg, code=Codes.UNKNOWN, **kwargs):
     """ Utility method for constructing an error response for client-server
     interactions.