def select_card(self):
"""Selects a card after a failed authentication attempt (aborted communications)
Returns the UID of the card selected
"""
nt = nfc.nfc_target()
_ = nfc.nfc_initiator_select_passive_target(self.__device, self.__modulations[0], None, 0, ctypes.byref(nt))
uid = "".join([chr(nt.nti.nai.abtUid[i]) for i in range(nt.nti.nai.szUidLen)])
return uid
def select_card(self):
"""Selects a card after a failed authentication attempt (aborted communications)
Returns the UID of the card selected
"""
nt = nfc.nfc_target()
_ = nfc.nfc_initiator_select_passive_target(self.__device, self.__modulations[0], None, 0, ctypes.byref(nt))
uid = "".join([chr(nt.nti.nai.abtUid[i]) for i in range(nt.nti.nai.szUidLen)])
return uid
def start_nfc_reader(self):
connection_loop = True
try:
self.log.debug('NFC init')
nfc.nfc_init(ctypes.byref(self.__context))
# Select HW reader
devices_found = nfc.nfc_list_devices(self.__context, ctypes.byref(self.__conn_strings), 1)
if devices_found != 1:
raise HWError('No suitable NFC device found. Check your libnfc config and hardware.')
# NFC abstraction: open
self.__device = nfc.nfc_open(self.__context, self.__conn_strings[0])
self.log.debug('NFC_open finished')
# Start reader as initiator with RF field, but without infinite polling to reduce CPU usage
result = nfc.nfc_initiator_init(self.__device)
if result < 0:
raise HWError('Could not start or configure reader as NFC initiator properly.')
self.log.debug('Started NFC initiator.')
while connection_loop:
self.log.info('Polling for NFC target...')
result += nfc.nfc_device_set_property_bool(self.__device, nfc.NP_INFINITE_SELECT, False)
found_card = nfc.nfc_initiator_select_passive_target(self.__device,
self.__modulation,
None,
0,
ctypes.byref(self.__target))
# Wait until target was found
if found_card > 0:
# Got target
self.log.debug('Connection established with ISO14443A modulation and baudrate type %d.',
self.__target.nm.nbr)
# Send UID to authenticate reader against Android device
# -> it will wait until Android's NFC service is ready
self.send_uid()
# Finish setup step
self.running = True
connection_loop = False
else:
# No target found
self.log.debug('No target found. Sleeping for 1 s.')
time.sleep(1.2)
except (KeyboardInterrupt, SystemExit):
connection_loop = False
except HWError as e:
self.log.error("Hardware exception: " + str(e))
connection_loop = False
except IOError as e:
self.log.error("IOError exception: " + str(e))
connection_loop = True
return connection_loop
