Cleanup credentials handling (#605)

* credentials: don't allow none to simplify checks

* Implement __bool__ for credentials

* Cleanup klaptransport cred usage

* Cleanup deviceconfig and tapodevice

* fix linting

* Pass dummy credentials for tests

* Remove __bool__ dunder and add docs to credentials

* Check for cred noneness in tapodevice.update()

kasa/credentials.py

@@ -1,12 +1,13 @@
 """Credentials class for username / passwords."""
 
 from dataclasses import dataclass, field
-from typing import Optional
 
 
 @dataclass
 class Credentials:
     """Credentials for authentication."""
 
-    username: Optional[str] = field(default="", repr=False)
+    #: Username (email address) of the cloud account
-    password: Optional[str] = field(default="", repr=False)
+    username: str = field(default="", repr=False)
+    #: Password of the cloud account
+    password: str = field(default="", repr=False)

kasa/deviceconfig.py

@@ -117,9 +117,7 @@ class DeviceConfig:
     host: str
     timeout: Optional[int] = DEFAULT_TIMEOUT
     port_override: Optional[int] = None
-    credentials: Credentials = field(
+    credentials: Credentials = field(default_factory=lambda: Credentials())
-        default_factory=lambda: Credentials(username="", password="")
-    )
     connection_type: ConnectionType = field(
         default_factory=lambda: ConnectionType(
             DeviceFamilyType.IotSmartPlugSwitch, EncryptType.Xor
@@ -132,7 +130,7 @@ class DeviceConfig:
 
     def __post_init__(self):
         if self.credentials is None:
-            self.credentials = Credentials(username="", password="")
+            self.credentials = Credentials()
         if self.connection_type is None:
             self.connection_type = ConnectionType(
                 DeviceFamilyType.IotSmartPlugSwitch, EncryptType.Xor

kasa/exceptions.py

@@ -26,6 +26,7 @@ class AuthenticationException(SmartDeviceException):
 class RetryableException(SmartDeviceException):
     """Retryable exception for device errors."""
 
+
 class TimeoutException(SmartDeviceException):
     """Timeout exception for device errors."""
 

kasa/klaptransport.py

@@ -221,7 +221,8 @@ class KlapTransport(BaseTransport):
             return local_seed, remote_seed, self._kasa_setup_auth_hash  # type: ignore
 
         # Finally check against blank credentials if not already blank
-        if self._credentials != (blank_creds := Credentials(username="", password="")):
+        blank_creds = Credentials()
+        if self._credentials != blank_creds:
             if not self._blank_auth_hash:
                 self._blank_auth_hash = self.generate_auth_hash(blank_creds)
 
@@ -369,8 +370,8 @@ class KlapTransport(BaseTransport):
     @staticmethod
     def generate_auth_hash(creds: Credentials):
         """Generate an md5 auth hash for the protocol on the supplied credentials."""
-        un = creds.username or ""
+        un = creds.username
-        pw = creds.password or ""
+        pw = creds.password
 
         return md5(md5(un.encode()) + md5(pw.encode()))
 
@@ -391,7 +392,7 @@ class KlapTransport(BaseTransport):
     @staticmethod
     def generate_owner_hash(creds: Credentials):
         """Return the MD5 hash of the username in this object."""
-        un = creds.username or ""
+        un = creds.username
         return md5(un.encode())
 
 
@@ -401,8 +402,8 @@ class KlapTransportV2(KlapTransport):
     @staticmethod
     def generate_auth_hash(creds: Credentials):
         """Generate an md5 auth hash for the protocol on the supplied credentials."""
-        un = creds.username or ""
+        un = creds.username
-        pw = creds.password or ""
+        pw = creds.password
 
         return _sha256(_sha1(un.encode()) + _sha1(pw.encode()))
 

kasa/tapo/tapodevice.py

@@ -38,8 +38,8 @@ class TapoDevice(SmartDevice):
 
     async def update(self, update_children: bool = True):
         """Update the device."""
-        if self.credentials is None or self.credentials.username is None:
+        if self.credentials is None:
-            raise AuthenticationException("Tapo plug requires authentication.")
+            raise AuthenticationException("Device requires authentication.")
 
         if self._components_raw is None:
             resp = await self.protocol.query("component_nego")

kasa/tests/newfakes.py

@@ -305,7 +305,13 @@ class FakeSmartProtocol(SmartProtocol):
 class FakeSmartTransport(BaseTransport):
     def __init__(self, info):
         super().__init__(
-            config=DeviceConfig("127.0.0.123", credentials=Credentials()),
+            config=DeviceConfig(
+                "127.0.0.123",
+                credentials=Credentials(
+                    username="dummy_user",
+                    password="dummy_password",  # noqa: S106
+                ),
+            ),
         )
         self.info = info
 

kasa/tests/test_device_factory.py

@@ -76,7 +76,12 @@ async def test_connect_custom_port(all_fixture_data: dict, mocker, custom_port):
     host = "127.0.0.1"
 
     ctype, _ = _get_connection_type_device_class(all_fixture_data)
-    config = DeviceConfig(host=host, port_override=custom_port, connection_type=ctype)
+    config = DeviceConfig(
+        host=host,
+        port_override=custom_port,
+        connection_type=ctype,
+        credentials=Credentials("dummy_user", "dummy_password"),
+    )
     default_port = 80 if "discovery_result" in all_fixture_data else 9999
 
     ctype, _ = _get_connection_type_device_class(all_fixture_data)