Add private key export support

- Add PRIVATE_KEY and DISABLED event types
- Add packet parsing for private key export responses
- Add export_private_key() method to DeviceCommands
- Add comprehensive unit tests
- Add BLE private key export example
- Update documentation with security notes

src/meshcore/commands/device.py

@@ -202,3 +202,7 @@ class DeviceCommands(CommandHandlerBase):
 
         data = b"\x20" + channel_idx.to_bytes(1, "little") + name_bytes + channel_secret
         return await self.send(data, [EventType.OK, EventType.ERROR])
+
+    async def export_private_key(self) -> Event:
+        logger.debug("Requesting private key export")
+        return await self.send(b"\x17", [EventType.PRIVATE_KEY, EventType.DISABLED, EventType.ERROR])

src/meshcore/events.py

@@ -41,6 +41,8 @@ class EventType(Enum):
     CUSTOM_VARS = "custom_vars"
     CHANNEL_INFO = "channel_info"
     PATH_RESPONSE = "path_response"
+    PRIVATE_KEY = "private_key"
+    DISABLED = "disabled"
 
     # Command response types
     OK = "command_ok"

src/meshcore/reader.py

@@ -569,6 +569,20 @@ class MessageReader:
                 Event(EventType.PATH_RESPONSE, res, attributes)
             )
 
+        elif packet_type_value == PacketType.PRIVATE_KEY.value:
+            logger.debug(f"Received private key response: {data.hex()}")
+            if len(data) >= 65:  # 1 byte response code + 64 bytes private key
+                private_key = data[1:65]  # Extract 64-byte private key
+                res = {"private_key": private_key}
+                await self.dispatcher.dispatch(Event(EventType.PRIVATE_KEY, res))
+            else:
+                logger.error(f"Invalid private key response length: {len(data)}")
+
+        elif packet_type_value == PacketType.DISABLED.value:
+            logger.debug("Received disabled response")
+            res = {"reason": "private_key_export_disabled"}
+            await self.dispatcher.dispatch(Event(EventType.DISABLED, res))
+
         else:
             logger.debug(f"Unhandled data received {data}")
             logger.debug(f"Unhandled packet type: {packet_type_value}")