Verify that the MAC address that Fully Kiosk reported is usable (#94887)

homeassistant/components/fully_kiosk/entity.py

@@ -9,6 +9,18 @@ from .const import DOMAIN
 from .coordinator import FullyKioskDataUpdateCoordinator
 
 
+def valid_global_mac_address(mac: str | None) -> bool:
+    """Check if a MAC address is valid, non-locally administered address."""
+    if not isinstance(mac, str):
+        return False
+    try:
+        first_octet = int(mac.split(":")[0], 16)
+        # If the second least-significant bit is set, it's a locally administered address, should not be used as an ID
+        return not bool(first_octet & 0x2)
+    except ValueError:
+        return False
+
+
 class FullyKioskEntity(CoordinatorEntity[FullyKioskDataUpdateCoordinator], Entity):
     """Defines a Fully Kiosk Browser entity."""
 
@@ -25,7 +37,9 @@ class FullyKioskEntity(CoordinatorEntity[FullyKioskDataUpdateCoordinator], Entit
             sw_version=coordinator.data["appVersionName"],
             configuration_url=f"http://{coordinator.data['ip4']}:2323",
         )
-        if "Mac" in coordinator.data and coordinator.data["Mac"]:
+        if "Mac" in coordinator.data and valid_global_mac_address(
+            coordinator.data["Mac"]
+        ):
             device_info["connections"] = {
                 (CONNECTION_NETWORK_MAC, coordinator.data["Mac"])
             }

tests/components/fully_kiosk/test_init.py

@@ -7,6 +7,7 @@ from fullykiosk import FullyKioskError
 import pytest
 
 from homeassistant.components.fully_kiosk.const import DOMAIN
+from homeassistant.components.fully_kiosk.entity import valid_global_mac_address
 from homeassistant.config_entries import ConfigEntryState
 from homeassistant.const import CONF_HOST, CONF_MAC, CONF_PASSWORD
 from homeassistant.core import HomeAssistant
@@ -134,3 +135,11 @@ async def test_multiple_kiosk_with_empty_mac(
     assert device2
 
     assert device1 != device2
+
+
+async def test_valid_global_mac_address() -> None:
+    """Test valid_global_mac_address function."""
+    assert valid_global_mac_address("a1:bb:cc:dd:ee:ff")
+    assert not valid_global_mac_address("02:00:00:00:00:00")
+    assert not valid_global_mac_address(None)
+    assert not valid_global_mac_address("foobar")