From c951fbedcb81895c199c1f4cfe2251d6c3a7b5f4 Mon Sep 17 00:00:00 2001 From: Patrick Cloke Date: Wed, 8 Feb 2023 13:09:41 -0500 Subject: [PATCH] MSC3873: Escape keys when flattening dicts. (#15004) This disambiguates keys which attempt to match fields with a dot in them (e.g. m.relates_to). Disabled by default behind an experimental configuration flag. --- changelog.d/15004.feature | 1 + synapse/config/experimental.py | 5 ++++ synapse/push/bulk_push_rule_evaluator.py | 30 ++++++++++++++++++++---- tests/push/test_push_rule_evaluator.py | 8 +++++++ 4 files changed, 40 insertions(+), 4 deletions(-) create mode 100644 changelog.d/15004.feature diff --git a/changelog.d/15004.feature b/changelog.d/15004.feature new file mode 100644 index 000000000..d11d0aca9 --- /dev/null +++ b/changelog.d/15004.feature @@ -0,0 +1 @@ +Implement [MSC3873](https://github.com/matrix-org/matrix-spec-proposals/pull/3873) to unambiguate push rule keys with dots in them. diff --git a/synapse/config/experimental.py b/synapse/config/experimental.py index 53c0682df..5e3a88908 100644 --- a/synapse/config/experimental.py +++ b/synapse/config/experimental.py @@ -169,6 +169,11 @@ class ExperimentalConfig(Config): # MSC3925: do not replace events with their edits self.msc3925_inhibit_edit = experimental.get("msc3925_inhibit_edit", False) + # MSC3873: Disambiguate event_match keys. + self.msc3783_escape_event_match_key = experimental.get( + "msc3783_escape_event_match_key", False + ) + # MSC3952: Intentional mentions self.msc3952_intentional_mentions = experimental.get( "msc3952_intentional_mentions", False diff --git a/synapse/push/bulk_push_rule_evaluator.py b/synapse/push/bulk_push_rule_evaluator.py index d9c0a98f4..39d2f88f0 100644 --- a/synapse/push/bulk_push_rule_evaluator.py +++ b/synapse/push/bulk_push_rule_evaluator.py @@ -271,7 +271,10 @@ class BulkPushRuleEvaluator: related_event_id, allow_none=True ) if related_event is not None: - related_events[relation_type] = _flatten_dict(related_event) + related_events[relation_type] = _flatten_dict( + related_event, + msc3783_escape_event_match_key=self.hs.config.experimental.msc3783_escape_event_match_key, + ) reply_event_id = ( event.content.get("m.relates_to", {}) @@ -286,7 +289,10 @@ class BulkPushRuleEvaluator: ) if related_event is not None: - related_events["m.in_reply_to"] = _flatten_dict(related_event) + related_events["m.in_reply_to"] = _flatten_dict( + related_event, + msc3783_escape_event_match_key=self.hs.config.experimental.msc3783_escape_event_match_key, + ) # indicate that this is from a fallback relation. if relation_type == "m.thread" and event.content.get( @@ -405,7 +411,10 @@ class BulkPushRuleEvaluator: room_mention = mentions.get("room") is True evaluator = PushRuleEvaluator( - _flatten_dict(event), + _flatten_dict( + event, + msc3783_escape_event_match_key=self.hs.config.experimental.msc3783_escape_event_match_key, + ), has_mentions, user_mentions, room_mention, @@ -493,6 +502,8 @@ def _flatten_dict( d: Union[EventBase, Mapping[str, Any]], prefix: Optional[List[str]] = None, result: Optional[Dict[str, str]] = None, + *, + msc3783_escape_event_match_key: bool = False, ) -> Dict[str, str]: """ Given a JSON dictionary (or event) which might contain sub dictionaries, @@ -521,11 +532,22 @@ def _flatten_dict( if result is None: result = {} for key, value in d.items(): + if msc3783_escape_event_match_key: + # Escape periods in the key with a backslash (and backslashes with an + # extra backslash). This is since a period is used as a separator between + # nested fields. + key = key.replace("\\", "\\\\").replace(".", "\\.") + if isinstance(value, str): result[".".join(prefix + [key])] = value.lower() elif isinstance(value, Mapping): # do not set `room_version` due to recursion considerations below - _flatten_dict(value, prefix=(prefix + [key]), result=result) + _flatten_dict( + value, + prefix=(prefix + [key]), + result=result, + msc3783_escape_event_match_key=msc3783_escape_event_match_key, + ) # `room_version` should only ever be set when looking at the top level of an event if ( diff --git a/tests/push/test_push_rule_evaluator.py b/tests/push/test_push_rule_evaluator.py index da3342387..516b65cc3 100644 --- a/tests/push/test_push_rule_evaluator.py +++ b/tests/push/test_push_rule_evaluator.py @@ -48,6 +48,14 @@ class FlattenDictTestCase(unittest.TestCase): input = {"foo": {"bar": "abc"}} self.assertEqual({"foo.bar": "abc"}, _flatten_dict(input)) + # If a field has a dot in it, escape it. + input = {"m.foo": {"b\\ar": "abc"}} + self.assertEqual({"m.foo.b\\ar": "abc"}, _flatten_dict(input)) + self.assertEqual( + {"m\\.foo.b\\\\ar": "abc"}, + _flatten_dict(input, msc3783_escape_event_match_key=True), + ) + def test_non_string(self) -> None: """Non-string items are dropped.""" input: Dict[str, Any] = {