def _tx_string(self, s):
"""This is only safe if it's guaranteed the card won't send any data
during the time of tx of the string !!!"""
self._sl.write(s)
r = self._sl.read(len(s))
if r != s: # TX and RX are tied, so we must clear the echo
raise ProtocolError("Bad echo value (Expected: %s, got %s)" % (b2h(s), b2h(r)))
def connect(self):
try:
# Explicitly select T=0 communication protocol
self._con.connect(CardConnection.T0_protocol)
except CardConnectionException:
raise ProtocolError()
except NoCardException:
raise NoCardError()
def send_apdu_raw(self, pdu):
"""see LinkBase.send_apdu_raw"""
pdu = h2b(pdu)
data_len = ord(pdu[4]) # P3
# Send first CLASS,INS,P1,P2,P3
self._tx_string(pdu[0:5])
# Wait ack which can be
# - INS: Command acked -> go ahead
# - 0x60: NULL, just wait some more
# - SW1: The card can apparently proceed ...
while True:
b = self._rx_byte()
if b == pdu[1]:
break
elif b != '\x60':
# Ok, it 'could' be SW1
sw1 = b
sw2 = self._rx_byte()
nil = self._rx_byte()
if (sw2 and not nil):
return '', b2h(sw1 + sw2)
raise ProtocolError()
# Send data (if any)
if len(pdu) > 5:
self._tx_string(pdu[5:])
# Receive data (including SW !)
# length = [P3 - tx_data (=len(pdu)-len(hdr)) + 2 (SW1/2) ]
to_recv = data_len - len(pdu) + 5 + 2
data = ''
while (len(data) < to_recv):
b = self._rx_byte()
if (to_recv == 2) and (
b == '\x60'): # Ignore NIL if we have no RX data (hack ?)
continue
if not b:
break
data += b
# Split datafield from SW
if len(data) < 2:
return None, None
sw = data[-2:]
data = data[0:-2]
# Return value
return b2h(data), b2h(sw)
def connect(self):
try:
# To avoid leakage of resources, make sure the reader
# is disconnected
self.disconnect()
# Explicitly select T=0 communication protocol
self._con.connect(CardConnection.T0_protocol)
except CardConnectionException:
raise ProtocolError()
except NoCardException:
raise NoCardError()
def _tx_byte(self, b):
self._sl.write(b)
r = self._sl.read()
if r != b: # TX and RX are tied, so we must clear the echo
raise ProtocolError("Bad echo value. Expected %02x, got %s)" %
(ord(b), '%02x' % ord(r) if r else '(nil)'))
def reset_card(self):
rv = self._reset_card()
if rv == 0:
raise NoCardError()
elif rv < 0:
raise ProtocolError()
