def transceive_message(self, tx_buf, tx_len, timeout=0):
assert self.__device != None
# Prepare message for sending
assert tx_len > 0
self.__tx_msg[:tx_len] = tx_buf
self.log.debug('Send [%d bytes]: %s', tx_len, hex_dump(tx_buf[:]))
# NFC hardware IO
rx_len = nfc.nfc_initiator_transceive_bytes(self.__device,
ctypes.byref(self.__tx_msg),
tx_len,
ctypes.byref(self.__rx_msg),
self.ISO7816_SHORT_APDU_MAX_LEN,
0)
# Receiving message
if rx_len > 0:
rx_buf = bytes((ctypes.c_char * rx_len).from_buffer(self.__rx_msg))
self.log.debug('Receive [%d bytes]: %s', rx_len, hex_dump(rx_buf[:rx_len]))
elif nfc.NFC_ERFTRANS == rx_len:
raise TargetLost('Lost link to target.')
elif nfc.NFC_EINVARG == rx_len:
# Invalid argument seems to be a keyboard interrupt
raise KeyboardInterrupt()
else:
# No valid response: link is probably broken
raise IOError("Invalid or no reply from target. libnfc type: " + str(rx_len))
return rx_buf, rx_len
def _authenticate(self, block, uid, key = "\xff\xff\xff\xff\xff\xff", use_b_key = False):
"""Authenticates to a particular block using a specified key"""
if nfc.nfc_device_set_property_bool(self.__device, nfc.NP_EASY_FRAMING, True) < 0:
raise Exception("Error setting Easy Framing property")
abttx = (ctypes.c_uint8 * 12)()
abttx[0] = self.MC_AUTH_A if not use_b_key else self.MC_AUTH_B
abttx[1] = block
for i in range(6):
abttx[i + 2] = ord(key[i])
for i in range(4):
abttx[i + 8] = ord(uid[i])
abtrx = (ctypes.c_uint8 * 250)()
return nfc.nfc_initiator_transceive_bytes(self.__device, ctypes.pointer(abttx), len(abttx),
ctypes.pointer(abtrx), len(abtrx), 0)
def _authenticate(self, block, uid, key = "\xff\xff\xff\xff\xff\xff", use_b_key = False):
"""Authenticates to a particular block using a specified key"""
if nfc.nfc_device_set_property_bool(self.__device, nfc.NP_EASY_FRAMING, True) < 0:
raise Exception("Error setting Easy Framing property")
abttx = (ctypes.c_uint8 * 12)()
abttx[0] = self.MC_AUTH_A if not use_b_key else self.MC_AUTH_B
abttx[1] = block
for i in range(6):
abttx[i + 2] = ord(key[i])
for i in range(4):
abttx[i + 8] = ord(uid[i])
abtrx = (ctypes.c_uint8 * 250)()
return nfc.nfc_initiator_transceive_bytes(self.__device, ctypes.pointer(abttx), len(abttx),
ctypes.pointer(abtrx), len(abtrx), 0)
def _read_block(self, block):
"""Reads a block from a Mifare Card after authentication
Returns the data read or raises an exception
"""
if nfc.nfc_device_set_property_bool(self.__device, nfc.NP_EASY_FRAMING, True) < 0:
raise Exception("Error setting Easy Framing property")
abttx = (ctypes.c_uint8 * 2)()
abttx[0] = self.MC_READ
abttx[1] = block
abtrx = (ctypes.c_uint8 * 250)()
res = nfc.nfc_initiator_transceive_bytes(self.__device, ctypes.pointer(abttx), len(abttx),
ctypes.pointer(abtrx), len(abtrx), 0)
if res < 0:
raise IOError("Error reading data")
return "".join([chr(abtrx[i]) for i in range(res)])
def _read_block(self, block):
"""Reads a block from a Mifare Card after authentication
Returns the data read or raises an exception
"""
if nfc.nfc_device_set_property_bool(self.__device, nfc.NP_EASY_FRAMING, True) < 0:
raise Exception("Error setting Easy Framing property")
abttx = (ctypes.c_uint8 * 2)()
abttx[0] = self.MC_READ
abttx[1] = block
abtrx = (ctypes.c_uint8 * 250)()
res = nfc.nfc_initiator_transceive_bytes(self.__device, ctypes.pointer(abttx), len(abttx),
ctypes.pointer(abtrx), len(abtrx), 0)
if res < 0:
raise IOError("Error reading data")
return "".join([chr(abtrx[i]) for i in range(res)])
def __write_block(self, block, data):
"""Writes a block of data to a Mifare Card after authentication
Raises an exception on error
"""
if nfc.nfc_device_set_property_bool(self.__device, nfc.NP_EASY_FRAMING, True) < 0:
raise Exception("Error setting Easy Framing property")
if len(data) > 16:
raise ValueError("Data value to be written cannot be more than 16 characters.")
abttx = (ctypes.c_uint8 * 18)()
abttx[0] = self.MC_WRITE
abttx[1] = block
abtrx = (ctypes.c_uint8 * 250)()
for i in range(16):
abttx[i + 2] = ord((data + "\x00" * (16 - len(data)))[i])
return nfc.nfc_initiator_transceive_bytes(self.__device, ctypes.pointer(abttx), len(abttx),
ctypes.pointer(abtrx), len(abtrx), 0)
def __write_block(self, block, data):
"""Writes a block of data to a Mifare Card after authentication
Raises an exception on error
"""
if nfc.nfc_device_set_property_bool(self.__device, nfc.NP_EASY_FRAMING, True) < 0:
raise Exception("Error setting Easy Framing property")
if len(data) > 16:
raise ValueError("Data value to be written cannot be more than 16 characters.")
abttx = (ctypes.c_uint8 * 18)()
abttx[0] = self.MC_WRITE
abttx[1] = block
abtrx = (ctypes.c_uint8 * 250)()
for i in range(16):
abttx[i + 2] = ord((data + "\x00" * (16 - len(data)))[i])
return nfc.nfc_initiator_transceive_bytes(self.__device, ctypes.pointer(abttx), len(abttx),
ctypes.pointer(abtrx), len(abtrx), 0)
