fix BLE HID not working with consumer keys

This commit is contained in:
Christian Tu 2021-10-01 15:37:43 +02:00 committed by Josh Klar
parent f7c0bd962b
commit 11ff03523b

View File

@ -244,8 +244,6 @@ class BLEHID(AbstractHID):
super().__init__()
def post_init(self):
self.conn_id = -1
self.ble = BLERadio()
self.ble.name = self.ble_name
self.hid = HIDService()
@ -259,72 +257,59 @@ class BLEHID(AbstractHID):
if not self.ble.connected or not self.hid.devices:
self.start_advertising()
self.conn_id = 0
@property
def devices(self):
'''Search through the provided list of devices to find the ones with the
send_report attribute.'''
if not self.ble.connected:
return []
return {}
result = {}
result = []
# Security issue:
# This introduces a race condition. Let's say you have 2 active
# connections: Alice and Bob - Alice is connection 1 and Bob 2.
# Now Chuck who has already paired with the device in the past
# (this assumption is needed only in the case of LESC)
# wants to gather the keystrokes you send to Alice. You have
# selected right now to talk to Alice (1) and you're typing a secret.
# If Chuck kicks Alice off and is quick enough to connect to you,
# which means quicker than the running interval of this function,
# he'll be earlier in the `self.hid.devices` so will take over the
# selected 1 position in the resulted array.
# If no LESC is in place, Chuck can sniff the keystrokes anyway
for device in self.hid.devices:
if hasattr(device, 'send_report'):
result.append(device)
if not hasattr(device, 'send_report'):
continue
us = device.usage
up = device.usage_page
if up == HIDUsagePage.CONSUMER and us == HIDUsage.CONSUMER:
result[HIDReportTypes.CONSUMER] = device
continue
if up == HIDUsagePage.KEYBOARD and us == HIDUsage.KEYBOARD:
result[HIDReportTypes.KEYBOARD] = device
continue
if up == HIDUsagePage.MOUSE and us == HIDUsage.MOUSE:
result[HIDReportTypes.MOUSE] = device
continue
if up == HIDUsagePage.SYSCONTROL and us == HIDUsage.SYSCONTROL:
result[HIDReportTypes.SYSCONTROL] = device
continue
return result
def _check_connection(self):
devices = self.devices
if not devices:
return False
if self.conn_id >= len(devices):
self.conn_id = len(devices) - 1
if self.conn_id < 0:
return False
if not devices[self.conn_id]:
return False
return True
def hid_send(self, evt):
if not self._check_connection():
if not self.ble.connected:
return
device = self.devices[self.conn_id]
# int, can be looked up in HIDReportTypes
reporting_device_const = self.report_device[0]
while len(evt) < len(device._characteristic.value) + 1:
device = self.devices[reporting_device_const]
report_size = len(device._characteristic.value)
while len(evt) < report_size + 1:
evt.append(0)
return device.send_report(evt[1:])
return device.send_report(evt[1 : report_size + 1])
def clear_bonds(self):
import _bleio
_bleio.adapter.erase_bonding()
def next_connection(self):
self.conn_id = (self.conn_id + 1) % len(self.devices)
def previous_connection(self):
self.conn_id = (self.conn_id - 1) % len(self.devices)
def start_advertising(self):
advertisement = ProvideServicesAdvertisement(self.hid)
advertisement.appearance = self.BLE_APPEARANCE_HID_KEYBOARD