Add klap protocol (#509)

* Add support for the new encryption protocol

This adds support for the new TP-Link discovery and encryption
protocols. It is currently incomplete - only devices without
username and password are current supported, and single device
discovery is not implemented.

Discovery should find both old and new devices. When accessing
a device by IP the --klap option can be specified on the command
line to active the new connection protocol.

sdb9696 - This commit also contains 16 later commits from Simon Wilkinson
squashed into the original

* Update klap changes 2023 to fix encryption, deal with kasa credential switching and work with new discovery changes

* Move from aiohttp to httpx

* Changes following review comments

---------

Co-authored-by: Simon Wilkinson <simon@sxw.org.uk>

kasa/protocol.py

@@ -14,6 +14,7 @@ import contextlib
 import errno
 import logging
 import struct
+from abc import ABC, abstractmethod
 from pprint import pformat as pf
 from typing import Dict, Generator, Optional, Union
 
@@ -21,6 +22,7 @@ from typing import Dict, Generator, Optional, Union
 # async_timeout can be replaced with asyncio.timeout
 from async_timeout import timeout as asyncio_timeout
 
+from .credentials import Credentials
 from .exceptions import SmartDeviceException
 from .json import dumps as json_dumps
 from .json import loads as json_loads
@@ -29,7 +31,31 @@ _LOGGER = logging.getLogger(__name__)
 _NO_RETRY_ERRORS = {errno.EHOSTDOWN, errno.EHOSTUNREACH, errno.ECONNREFUSED}
 
 
-class TPLinkSmartHomeProtocol:
+class TPLinkProtocol(ABC):
+    """Base class for all TP-Link Smart Home communication."""
+
+    def __init__(
+        self,
+        host: str,
+        *,
+        port: Optional[int] = None,
+        credentials: Optional[Credentials] = None,
+    ) -> None:
+        """Create a protocol object."""
+        self.host = host
+        self.port = port
+        self.credentials = credentials
+
+    @abstractmethod
+    async def query(self, request: Union[str, Dict], retry_count: int = 3) -> Dict:
+        """Query the device for the protocol.  Abstract method to be overriden."""
+
+    @abstractmethod
+    async def close(self) -> None:
+        """Close the protocol.  Abstract method to be overriden."""
+
+
+class TPLinkSmartHomeProtocol(TPLinkProtocol):
     """Implementation of the TP-Link Smart Home protocol."""
 
     INITIALIZATION_VECTOR = 171
@@ -38,11 +64,18 @@ class TPLinkSmartHomeProtocol:
     BLOCK_SIZE = 4
 
     def __init__(
-        self, host: str, *, port: Optional[int] = None, timeout: Optional[int] = None
+        self,
+        host: str,
+        *,
+        port: Optional[int] = None,
+        timeout: Optional[int] = None,
+        credentials: Optional[Credentials] = None,
     ) -> None:
         """Create a protocol object."""
-        self.host = host
-        self.port = port or TPLinkSmartHomeProtocol.DEFAULT_PORT
+        super().__init__(
+            host=host, port=port or self.DEFAULT_PORT, credentials=credentials
+        )
+
         self.reader: Optional[asyncio.StreamReader] = None
         self.writer: Optional[asyncio.StreamWriter] = None
         self.query_lock = asyncio.Lock()