Allow to configure if pushkey should be converted to hex before sendi…

…ng to APNs (#344)

Some APNs libraries give the pushkey in hex directly, but sygnal assumes
that the pushkey is given in base64 (and attempts to convert it to hex).

This adds a configuration option to avoid this processing / assumption.

changelog.d/344.feature

@@ -0,0 +1 @@
+Add a new `convert_device_token_to_hex` configuration option for APNs apps, to allow disabling the conversion of device tokens from base64 to hex.

sygnal.yaml.sample

@@ -197,6 +197,11 @@ apps:
  # #
  # # The default is 'production'. Uncomment to use the sandbox instance.
  # #platform: sandbox
+ # #
+ # # Specifies whether to convert the device push token from base 64 to hex.
+ # # Defaults to True, set this to False if your client library provides a
+ # # push token in hex format.
+ # #convert_device_token_to_hex: false
 
  # This is an example GCM/FCM push configuration.
  #

sygnal/apnspushkin.py

@@ -238,7 +238,12 @@ async def _dispatch_request(
  """
  span.set_tag("apns_id", notif_id)
 
- device_token = base64.b64decode(device.pushkey).hex()
+ # Some client libraries will provide the push token in hex format already. Avoid
+ # attempting to convert from base 64 to hex.
+ if self.get_config("convert_device_token_to_hex", bool, True):
+ device_token = base64.b64decode(device.pushkey).hex()
+ else:
+ device_token = device.pushkey
 
  request = NotificationRequest(
  device_token=device_token,