From c2a5cf2fe32d2cd582711669b7c0ce74682e1c05 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <richard@matrix.org>
Date: Tue, 27 Mar 2018 17:07:31 +0100
Subject: [PATCH 1/2] factor out exception handling for keys/claim and
 keys/query

this stuff is badly c&p'ed
---
 synapse/handlers/e2e_keys.py | 53 +++++++++++++++++-------------------
 1 file changed, 25 insertions(+), 28 deletions(-)

diff --git a/synapse/handlers/e2e_keys.py b/synapse/handlers/e2e_keys.py
index 80b359b2e..41521e699 100644
--- a/synapse/handlers/e2e_keys.py
+++ b/synapse/handlers/e2e_keys.py
@@ -1,5 +1,6 @@
 # -*- coding: utf-8 -*-
 # Copyright 2016 OpenMarket Ltd
+# Copyright 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.
@@ -134,23 +135,8 @@ class E2eKeysHandler(object):
                     if user_id in destination_query:
                         results[user_id] = keys
 
-            except CodeMessageException as e:
-                failures[destination] = {
-                    "status": e.code, "message": e.message
-                }
-            except NotRetryingDestination as e:
-                failures[destination] = {
-                    "status": 503, "message": "Not ready for retry",
-                }
-            except FederationDeniedError as e:
-                failures[destination] = {
-                    "status": 403, "message": "Federation Denied",
-                }
             except Exception as e:
-                # include ConnectionRefused and other errors
-                failures[destination] = {
-                    "status": 503, "message": e.message
-                }
+                failures[destination] = _exception_to_failure(e)
 
         yield make_deferred_yieldable(defer.gatherResults([
             preserve_fn(do_remote_query)(destination)
@@ -252,19 +238,8 @@ class E2eKeysHandler(object):
                 for user_id, keys in remote_result["one_time_keys"].items():
                     if user_id in device_keys:
                         json_result[user_id] = keys
-            except CodeMessageException as e:
-                failures[destination] = {
-                    "status": e.code, "message": e.message
-                }
-            except NotRetryingDestination as e:
-                failures[destination] = {
-                    "status": 503, "message": "Not ready for retry",
-                }
             except Exception as e:
-                # include ConnectionRefused and other errors
-                failures[destination] = {
-                    "status": 503, "message": e.message
-                }
+                failures[destination] = _exception_to_failure(e)
 
         yield make_deferred_yieldable(defer.gatherResults([
             preserve_fn(claim_client_keys)(destination)
@@ -362,6 +337,28 @@ class E2eKeysHandler(object):
         )
 
 
+def _exception_to_failure(e):
+    if isinstance(e, CodeMessageException):
+        return {
+            "status": e.code, "message": e.message,
+        }
+
+    if isinstance(e, NotRetryingDestination):
+        return {
+            "status": 503, "message": "Not ready for retry",
+        }
+
+    if isinstance(e, FederationDeniedError):
+        return {
+            "status": 403, "message": "Federation Denied",
+        }
+
+    # include ConnectionRefused and other errors
+    return {
+        "status": 503, "message": e.message,
+    }
+
+
 def _one_time_keys_match(old_key_json, new_key):
     old_key = json.loads(old_key_json)
 

From a134c572a6697fa6443525493e3fc13f74452d34 Mon Sep 17 00:00:00 2001
From: Richard van der Hoff <richard@matrix.org>
Date: Tue, 27 Mar 2018 17:15:06 +0100
Subject: [PATCH 2/2] Stringify exceptions for keys/{query,claim}

Make sure we stringify any exceptions we return from keys/query and keys/claim,
to avoid a 'not JSON serializable' error later

Fixes #3010
---
 synapse/handlers/e2e_keys.py | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/synapse/handlers/e2e_keys.py b/synapse/handlers/e2e_keys.py
index 41521e699..325c0c4a9 100644
--- a/synapse/handlers/e2e_keys.py
+++ b/synapse/handlers/e2e_keys.py
@@ -354,8 +354,11 @@ def _exception_to_failure(e):
         }
 
     # include ConnectionRefused and other errors
+    #
+    # Note that some Exceptions (notably twisted's ResponseFailed etc) don't
+    # give a string for e.message, which simplejson then fails to serialize.
     return {
-        "status": 503, "message": e.message,
+        "status": 503, "message": str(e.message),
     }