Add default value (None) to channel.waiting_for_ack_timeout, create pairing state if branch

core/src/trezor/wire/thp/channel.py

@@ -49,7 +49,7 @@ class Channel(Context):
         super().__init__(iface, channel_cache.channel_id)
         self.channel_cache = channel_cache
         self.buffer: utils.BufferType
-        self.waiting_for_ack_timeout: loop.spawn | None
+        self.waiting_for_ack_timeout: loop.spawn | None = None
         self.is_cont_packet_expected: bool = False
         self.expected_payload_length: int = 0
         self.bytes_read = 0
@@ -211,6 +211,10 @@ class Channel(Context):
         if state is ChannelState.TH2:
             await self._handle_state_TH2(message_length, sync_bit)
             return
+        if is_channel_state_pairing(state):
+            await self._handle_pairing(message_length)
+            return
+        raise ThpError("Unimplemented channel state")
 
     async def _handle_state_TH1(
         self, payload_length: int, message_length: int, sync_bit: int
@@ -279,6 +283,9 @@ class Channel(Context):
             )
         )
 
+    async def _handle_pairing(self, message_length: int) -> None:
+        pass
+
     def _handle_channel_message(self, message_length: int, message_type: int) -> None:
         buf = self.buffer[INIT_DATA_OFFSET + 3 : message_length - CHECKSUM_LENGTH]
 
@@ -581,6 +588,18 @@ def _is_ctrl_byte_ack(ctrl_byte: int) -> bool:
     return ctrl_byte & 0xEF == ACK_MESSAGE
 
 
+def is_channel_state_pairing(state: int) -> bool:
+    if state in (
+        ChannelState.TP1,
+        ChannelState.TP2,
+        ChannelState.TP3,
+        ChannelState.TP4,
+        ChannelState.TP5,
+    ):
+        return True
+    return False
+
+
 def _state_to_str(state: int) -> str:
     if state == ChannelState.ENCRYPTED_TRANSPORT:
         return "state: encrypted transport"