fix(matrix): align SAS verification message flow

nanobot/channels/matrix.py

@@ -28,7 +28,6 @@ try:
         KeyVerificationKey,
         KeyVerificationMac,
         KeyVerificationStart,
-        LocalProtocolError,
         LoginResponse,
         MatrixRoom,
         RoomEncryptedMedia,
@@ -626,26 +625,14 @@ class MatrixChannel(BaseChannel):
             response = await self.client.accept_key_verification(transaction_id)
             if isinstance(response, ToDeviceError):
                 self.logger.warning("Matrix SAS accept failed for {}: {}", sender, response)
-                return
-
-            sas = getattr(self.client, "key_verifications", {}).get(transaction_id)
-            if sas is None:
-                self.logger.warning(
-                    "Matrix SAS state missing after accept for transaction {}",
-                    transaction_id,
-                )
-                return
-
-            response = await self.client.to_device(sas.share_key())
-            if isinstance(response, ToDeviceError):
-                self.logger.warning(
-                    "Matrix SAS key share failed for {}: {}",
-                    sender,
-                    response,
-                )
             return
 
         if isinstance(event, KeyVerificationKey):
+            responses = await self.client.send_to_device_messages()
+            if any(isinstance(response, ToDeviceError) for response in responses):
+                self.logger.warning("Matrix SAS key share failed for {}", sender)
+                return
+
             response = await self.client.confirm_short_auth_string(transaction_id)
             if isinstance(response, ToDeviceError):
                 self.logger.warning("Matrix SAS confirm failed for {}: {}", sender, response)
@@ -653,20 +640,7 @@ class MatrixChannel(BaseChannel):
 
         if isinstance(event, KeyVerificationMac):
             sas = getattr(self.client, "key_verifications", {}).get(transaction_id)
-            if sas is None:
+            if sas is not None and getattr(sas, "verified", False):
-                self.logger.warning(
-                    "Matrix SAS state missing for MAC transaction {}",
-                    transaction_id,
-                )
-                return
-            try:
-                response = await self.client.to_device(sas.get_mac())
-            except LocalProtocolError as e:
-                self.logger.warning("Matrix SAS MAC failed for {}: {}", sender, e)
-                return
-            if isinstance(response, ToDeviceError):
-                self.logger.warning("Matrix SAS MAC send failed for {}: {}", sender, response)
-            else:
                 self.logger.info("Matrix SAS verification completed for {}", sender)
             return
 

tests/channels/test_matrix_channel.py

@@ -53,11 +53,14 @@ class _FakeAsyncClient:
         self.to_device_callbacks: list[tuple[object, object]] = []
         self.response_callbacks: list[tuple[object, object]] = []
         self.key_verifications: dict[str, object] = {}
+        self.operation_calls: list[str] = []
         self.accept_key_verification_calls: list[str] = []
         self.confirm_short_auth_string_calls: list[str] = []
+        self.send_to_device_messages_calls = 0
         self.to_device_calls: list[object] = []
         self.accept_key_verification_response: object | None = None
         self.confirm_short_auth_string_response: object | None = None
+        self.send_to_device_messages_response: list[object] = []
         self.to_device_response: object | None = None
         self.rooms: dict[str, object] = {}
         self.room_send_calls: list[dict[str, object]] = []
@@ -94,14 +97,22 @@ class _FakeAsyncClient:
         self.join_calls.append(room_id)
 
     async def accept_key_verification(self, transaction_id: str):
+        self.operation_calls.append(f"accept:{transaction_id}")
         self.accept_key_verification_calls.append(transaction_id)
         return self.accept_key_verification_response
 
     async def confirm_short_auth_string(self, transaction_id: str):
+        self.operation_calls.append(f"confirm:{transaction_id}")
         self.confirm_short_auth_string_calls.append(transaction_id)
         return self.confirm_short_auth_string_response
 
+    async def send_to_device_messages(self):
+        self.operation_calls.append("send_pending")
+        self.send_to_device_messages_calls += 1
+        return self.send_to_device_messages_response
+
     async def to_device(self, message):
+        self.operation_calls.append("to_device")
         self.to_device_calls.append(message)
         return self.to_device_response
 
@@ -190,9 +201,10 @@ class _FakeAsyncClient:
 
 
 class _FakeSas:
-    def __init__(self) -> None:
+    def __init__(self, *, verified: bool = False) -> None:
         self.share_key_called = False
         self.get_mac_called = False
+        self.verified = verified
 
     def share_key(self):
         self.share_key_called = True
@@ -346,8 +358,8 @@ async def test_sas_verification_start_accepts_allowed_sender(monkeypatch) -> Non
     await channel._handle_key_verification_event(_FakeKeyVerificationStart())
 
     assert client.accept_key_verification_calls == ["tx1"]
-    assert sas.share_key_called is True
+    assert sas.share_key_called is False
-    assert client.to_device_calls == [{"type": "share_key"}]
+    assert client.to_device_calls == []
 
 
 @pytest.mark.asyncio
@@ -398,25 +410,27 @@ async def test_sas_verification_key_confirms_allowed_sender(monkeypatch) -> None
 
     await channel._handle_key_verification_event(_FakeKeyVerificationKey())
 
+    assert client.send_to_device_messages_calls == 1
     assert client.confirm_short_auth_string_calls == ["tx1"]
+    assert client.operation_calls == ["send_pending", "confirm:tx1"]
 
 
 @pytest.mark.asyncio
-async def test_sas_verification_mac_sends_mac_for_allowed_sender(monkeypatch) -> None:
+async def test_sas_verification_mac_does_not_resend_mac(monkeypatch) -> None:
     _patch_key_verification_events(monkeypatch)
     channel = MatrixChannel(
         _make_config(allow_from=["@alice:matrix.org"], sas_verification=True),
         MessageBus(),
     )
     client = _FakeAsyncClient("", "", "", None)
-    sas = _FakeSas()
+    sas = _FakeSas(verified=True)
     client.key_verifications["tx1"] = sas
     channel.client = client
 
     await channel._handle_key_verification_event(_FakeKeyVerificationMac())
 
-    assert sas.get_mac_called is True
+    assert sas.get_mac_called is False
-    assert client.to_device_calls == [{"type": "mac"}]
+    assert client.to_device_calls == []
 
 
 def test_media_event_filter_does_not_match_text_events() -> None: