Merge pull request #36 from kevincar/35-characteristic-protection-level

Characteristic protection level
kevincar · May 8, 2021 · 5116de9 · 5116de9
2 parents cdf8b28 + ca743b6
commit 5116de9
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Showing 2 changed files with 44 additions and 11 deletions.
diff --git a/bless/backends/dotnet/characteristic.py b/bless/backends/dotnet/characteristic.py
@@ -1,15 +1,12 @@
-from enum import Flag
-
 from bleak.backends.dotnet.characteristic import (  # type: ignore
     BleakGATTCharacteristicDotNet,
 )
 
+from Windows.Devices.Bluetooth.GenericAttributeProfile import (  # type: ignore
+    GattProtectionLevel
+)
 
-class CBAttributePermissions(Flag):
-    readable = 0x1
-    writeable = 0x2
-    read_encryption_required = 0x4
-    write_encryption_required = 0x8
+from bless.backends.characteristic import GATTAttributePermissions
 
 
 class BlessGATTCharacteristicDotNet(BleakGATTCharacteristicDotNet):
@@ -21,6 +18,33 @@ def __init__(self, obj):
         super().__init__(obj)
         self._value: bytearray = bytearray(b"")
 
+    @staticmethod
+    def permissions_to_protection_level(
+        permissions: GATTAttributePermissions, read: bool
+    ) -> GattProtectionLevel:
+        """
+        Convert the GATTAttributePermissions into a GattProtectionLevel
+        GATTAttributePermissions currently only consider Encryption or Plain
+
+        Parameters
+        ----------
+        permissions : GATTAttributePermissions
+            The permission flags for the characteristic
+        read : bool
+            If True, processes the permissions for Reading, else process for Writing
+
+        Returns
+        -------
+        GattProtectionLevel
+            The protection level equivalent
+        """
+        result: GattProtectionLevel = GattProtectionLevel.Plain
+        shift_value: int = 3 if read else 4
+        permission_value: int = permissions.value >> shift_value
+        if permission_value & 1:
+            result |= GattProtectionLevel.EncryptionRequired
+        return result
+
     @property
     def value(self) -> bytearray:
         """Get the value of the characteristic"""

diff --git a/bless/backends/dotnet/server.py b/bless/backends/dotnet/server.py
@@ -12,9 +12,9 @@
 from bless.exceptions import BlessError
 from bless.backends.server import BaseBlessServer  # type: ignore
 from bless.backends.characteristic import (  # type: ignore
-        GATTCharacteristicProperties,
-        GATTAttributePermissions
-        )
+    GATTCharacteristicProperties,
+    GATTAttributePermissions,
+)
 from bless.backends.dotnet.service import BlessGATTServiceDotNet
 from bless.backends.dotnet.characteristic import (  # type: ignore
     BlessGATTCharacteristicDotNet,
@@ -220,7 +220,16 @@ async def add_new_characteristic(
             GattLocalCharacteristicParameters()
         )
         ReadParameters.CharacteristicProperties = properties.value
-        ReadParameters.ReadProtectionLevel = permissions.value
+        ReadParameters.ReadProtectionLevel = (
+            BlessGATTCharacteristicDotNet.permissions_to_protection_level(
+                permissions, True
+            )
+        )
+        ReadParameters.WriteProtectionLevel = (
+            BlessGATTCharacteristicDotNet.permissions_to_protection_level(
+                permissions, False
+            )
+        )
 
         service: GattLocalService = self.services[str(serverguid)]
         characteristic_result: GattLocalCharacteristicResult = (