Accept homekit_controller pairing codes both with and without dashes (#30273)

* Handle MalformedPinError from homekit_python
* Handle both formats of pin codes

homeassistant/components/homekit_controller/config_flow.py

@@ -2,6 +2,7 @@
 import json
 import logging
 import os
+import re
 
 import homekit
 from homekit.controller.ip_implementation import IpPairing
@@ -17,6 +18,8 @@ HOMEKIT_IGNORE = ["Home Assistant Bridge"]
 HOMEKIT_DIR = ".homekit"
 PAIRING_FILE = "pairing.json"
 
+PIN_FORMAT = re.compile(r"^(\d{3})-{0,1}(\d{2})-{0,1}(\d{3})$")
+
 _LOGGER = logging.getLogger(__name__)
 
 
@@ -59,6 +62,20 @@ def find_existing_host(hass, serial):
             return entry
 
 
+def ensure_pin_format(pin):
+    """
+    Ensure a pin code is correctly formatted.
+
+    Ensures a pin code is in the format 111-11-111. Handles codes with and without dashes.
+
+    If incorrect code is entered, an exception is raised.
+    """
+    match = PIN_FORMAT.search(pin)
+    if not match:
+        raise homekit.exceptions.MalformedPinError(f"Invalid PIN code f{pin}")
+    return "{}-{}-{}".format(*match.groups())
+
+
 @config_entries.HANDLERS.register(DOMAIN)
 class HomekitControllerFlowHandler(config_entries.ConfigFlow):
     """Handle a HomeKit config flow."""
@@ -277,6 +294,8 @@ class HomekitControllerFlowHandler(config_entries.ConfigFlow):
         if pair_info:
             code = pair_info["pairing_code"]
             try:
+                code = ensure_pin_format(code)
+
                 await self.hass.async_add_executor_job(self.finish_pairing, code)
 
                 pairing = self.controller.pairings.get(self.hkid)
@@ -284,6 +303,9 @@ class HomekitControllerFlowHandler(config_entries.ConfigFlow):
                     return await self._entry_from_accessory(pairing)
 
                 errors["pairing_code"] = "unable_to_pair"
+            except homekit.exceptions.MalformedPinError:
+                # Library claimed pin was invalid before even making an API call
+                errors["pairing_code"] = "authentication_error"
             except homekit.AuthenticationError:
                 # PairSetup M4 - SRP proof failed
                 # PairSetup M6 - Ed25519 signature verification failed