wip: further CPy compatibility

blink.py

@@ -5,20 +5,21 @@
 """Simple LED on and off as a light."""
 
 import os
-import cm_fake_random
 
 import board
 import digitalio
 
 import circuitmatter as cm
+import cm_fake_random
 from circuitmatter.device_types.lighting import on_off
 
 try:
     print("removing matter-device-state.json if present")
     os.remove("matter-device-state.json")
-except FileNotFoundError:
+except OSError:
     pass
 
+
 class LED(on_off.OnOffLight):
     def __init__(self, name, led):
         super().__init__(name)

circuitmatter/clusters/device_management/basic_information.py

@@ -2,8 +2,7 @@
 #
 # SPDX-License-Identifier: MIT
 
-import enum
-
+import cm_enum as enum
 from circuitmatter import tlv
 from circuitmatter.data_model import (
     BoolAttribute,

circuitmatter/clusters/device_management/network_commissioning.py

@@ -2,8 +2,7 @@
 #
 # SPDX-License-Identifier: MIT
 
-import enum
-
+import cm_enum as enum
 from circuitmatter import tlv
 from circuitmatter.data_model import (
     BitmapAttribute,

circuitmatter/clusters/general/level_control.py

@@ -2,8 +2,7 @@
 #
 # SPDX-License-Identifier: MIT
 
-import enum
-
+import cm_enum as enum
 from circuitmatter import data_model, tlv
 
 

circuitmatter/clusters/general/on_off.py

@@ -2,8 +2,7 @@
 #
 # SPDX-License-Identifier: MIT
 
-import enum
-
+import cm_enum as enum
 from circuitmatter import data_model, tlv
 
 

circuitmatter/clusters/lighting/color_control.py

@@ -2,8 +2,7 @@
 #
 # SPDX-License-Identifier: MIT
 
-import enum
-
+import cm_enum as enum
 from circuitmatter import data_model, tlv
 
 

circuitmatter/crypto.py

@@ -2,19 +2,13 @@
 #
 # SPDX-License-Identifier: MIT
 
-try:
-    import enum
-except ImportError:
-    class enum:
-        class IntEnum:
-            pass
-
 import hashlib
 import struct
 
-from cm_sha import sha256
 import cm_ecdsa as ecdsa
+import cm_enum as enum
 import cm_hmac as hmac
+from cm_sha import sha256
 
 from . import tlv
 

circuitmatter/data_model.py

@@ -3,14 +3,17 @@
 # SPDX-License-Identifier: MIT
 
 import binascii
-import enum
-import inspect
 import random
 import struct
 import traceback
-import typing
-from collections.abc import Iterable
-from typing import Union
+
+try:
+    from collections.abc import Iterable
+    from typing import Union
+except ImportError:
+    pass
+
+import cm_enum as enum
 
 from . import interaction_model, tlv
 
@@ -232,7 +235,7 @@ def __str__(self):
 
 class ListAttribute(Attribute):
     def __init__(self, _id, element_type, **kwargs):
-        if inspect.isclass(element_type) and issubclass(element_type, enum.Enum):
+        if isinstance(element_type, type) and issubclass(element_type, enum.Enum):
             element_type = tlv.EnumMember(None, element_type)
         self.tlv_type = tlv.ArrayMember(None, element_type)
         self._element_type = element_type

circuitmatter/device_types/lighting/dimmable.py

@@ -2,8 +2,6 @@
 #
 # SPDX-License-Identifier: MIT
 
-import abc
-
 from circuitmatter.clusters.general import level_control
 
 from .on_off import OnOffLight
@@ -42,6 +40,5 @@ def brightness(self):
         return self._level_control.CurrentLevel / self._level_control.max_level
 
     @brightness.setter
-    @abc.abstractmethod
     def brightness(self, value):
         raise NotImplementedError()

circuitmatter/device_types/lighting/on_off.py

@@ -2,8 +2,6 @@
 #
 # SPDX-License-Identifier: MIT
 
-import abc
-
 from circuitmatter.clusters.general import on_off
 from circuitmatter.clusters.general.identify import Identify
 
@@ -44,12 +42,10 @@ def _off(self, session):
             return
         self._on_off.OnOff = False
 
-    @abc.abstractmethod
     def on(self):
         """Called when the light is turned on"""
         pass
 
-    @abc.abstractmethod
     def off(self):
         """Called when the light is turned off"""
         pass

circuitmatter/device_types/simple_device.py

@@ -2,12 +2,11 @@
 #
 # SPDX-License-Identifier: MIT
 
-from abc import ABC
-
 from circuitmatter.clusters.system_model import binding, descriptor, user_label
 
 
-class SimpleDevice(ABC):
+# abstract
+class SimpleDevice:
     def __init__(self, name):
         self.name = name
         self.servers = []

circuitmatter/interaction_model.py

@@ -2,7 +2,7 @@
 #
 # SPDX-License-Identifier: MIT
 
-import enum
+import cm_enum as enum
 
 from . import protocol, tlv
 

circuitmatter/message.py

@@ -2,9 +2,14 @@
 #
 # SPDX-License-Identifier: MIT
 
-import enum
 import struct
-from typing import Optional
+
+try:
+    from typing import Optional
+except ImportError:
+    pass
+
+import cm_enum as enum
 
 from . import tlv
 from .protocol import ProtocolId

circuitmatter/pase.py

@@ -5,8 +5,7 @@
 import hashlib
 import struct
 
-from cryptography.hazmat.primitives.ciphers.aead import AESCCM
-
+from cm_aesccm import AESCCM
 from cm_ecdsa.curves import NIST256p
 from cm_ecdsa.ellipticcurve import AbstractPoint, Point, PointJacobi
 

circuitmatter/protocol.py

@@ -2,12 +2,7 @@
 #
 # SPDX-License-Identifier: MIT
 
-try:
-    import enum
-except ImportError:
-    class enum:
-        class IntEnum:
-            pass
+import cm_enum as enum
 
 
 class SecureProtocolOpcode(enum.IntEnum):

circuitmatter/session.py

@@ -5,16 +5,8 @@
 import struct
 import time
 
-try:
-    import enum
-except ImportError:
-    class enum:
-        class IntEnum:
-            pass
-
-import cryptography
-from cryptography.hazmat.primitives.ciphers.aead import AESCCM
-
+import cm_enum as enum
+from cm_aesccm import AESCCM, InvalidTag
 from cm_sha import sha256
 
 from . import case, crypto, protocol, tlv
@@ -285,7 +277,7 @@ def decrypt_and_verify(self, message):
             decrypted_payload = cipher.decrypt(
                 self._nonce, bytes(message.payload), bytes(message.header)
             )
-        except cryptography.exceptions.InvalidTag:
+        except InvalidTag:
             return False
 
         message.decrypted = True
@@ -684,7 +676,7 @@ def reply_to_sigma3(self, exchange, sigma3) -> SecureChannelProtocolCode:
         )
         try:
             decrypted = s3k_cipher.decrypt(b"NCASE_Sigma3N", sigma3.encrypted3, b"")
-        except cryptography.exceptions.InvalidTag:
+        except InvalidTag:
             return SecureChannelProtocolCode.INVALID_PARAMETER
         sigma3_tbe = case.Sigma3TbeData.decode(decrypted)
 

circuitmatter/tlv.py

@@ -4,29 +4,23 @@
 
 from __future__ import annotations
 
-try:
-    import enum
-except ImportError:
-    class enum:
-        class IntEnum:
-            pass
-        pass
-
 import math
 import struct
 
 try:
+    from collections.abc import Iterable
     from typing import (
         AnyStr,
         Generic,
-        Iterable,
         Literal,
         TypeVar,
         overload,
     )
 except ImportError:
     pass
 
+import cm_enum as enum
+
 # As a byte string to save space.
 TAG_LENGTH = b"\x00\x01\x02\x04\x02\x04\x06\x08"
 INT_SIZE = "BHIQ"
@@ -39,15 +33,16 @@ def _mro(cls):
         return [object]
     return [cls] + _mro_merge([_mro(base) for base in cls.__bases__])
 
+
 def _mro_merge(mros):
-    if not any(mros): # all lists are empty
+    if not any(mros):  # all lists are empty
         return []  # base case
     for candidate, *_ in mros:
         if all(candidate not in tail for _, *tail in mros):
-            return [candidate] + _mro_merge([tail if head is candidate else [head, *tail]
-                                        for head, *tail in mros])
-    else:
-        raise TypeError("No legal mro")
+            return [candidate] + _mro_merge([
+                tail if head is candidate else [head] + tail for head, *tail in mros
+            ])
+    raise TypeError("No legal mro")
 
 
 class ElementType(enum.IntEnum):

circuitmatter/hm_aesccm.py → cm_aesccm.py

@@ -3,12 +3,15 @@
 # SPDX-License-Identifier: MIT
 
 try:
-    from cryptography.hazmat.primitives.ciphers.aead import AESCCM
     from cryptography.exceptions import InvalidTag
+    from cryptography.hazmat.primitives.ciphers.aead import AESCCM
 except ImportError:
     # Provide an exception raised by cryptography.
     class InvalidTag(Exception):
         pass
 
     # Use a CircuitPython implementation.
-    from hm_aesccm_aesio import *
+    from cm_aesccm_aesio import new
+
+    def AESCCM(key, *, tag_length=16):
+        return new(key, mac_len=tag_length)