#!/usr/bin/python
#
# Example nfcpy to wpa_supplicant wrapper for P2P NFC operations
# Copyright (c) 2012-2013, Jouni Malinen <j@w1.fi>
#
# This software may be distributed under the terms of the BSD license.
# See README for more details.
import os
import sys
import time
import random
import threading
import argparse
import nfc
import nfc.ndef
import nfc.llcp
import nfc.handover
import logging
import wpaspy
wpas_ctrl = '/var/run/wpa_supplicant'
ifname = None
init_on_touch = False
in_raw_mode = False
prev_tcgetattr = 0
include_wps_req = True
include_p2p_req = True
no_input = False
srv = None
continue_loop = True
terminate_now = False
summary_file = None
success_file = None
def summary(txt):
print txt
if summary_file:
with open(summary_file, 'a') as f:
f.write(txt + "\n")
def success_report(txt):
summary(txt)
if success_file:
with open(success_file, 'a') as f:
f.write(txt + "\n")
def wpas_connect():
ifaces = []
if os.path.isdir(wpas_ctrl):
try:
ifaces = [os.path.join(wpas_ctrl, i) for i in os.listdir(wpas_ctrl)]
except OSError, error:
print "Could not find wpa_supplicant: ", error
return None
if len(ifaces) < 1:
print "No wpa_supplicant control interface found"
return None
for ctrl in ifaces:
if ifname:
if ifname not in ctrl:
continue
try:
print "Trying to use control interface " + ctrl
wpas = wpaspy.Ctrl(ctrl)
return wpas
except Exception, e:
pass
return None
def wpas_tag_read(message):
wpas = wpas_connect()
if (wpas == None):
return False
cmd = "WPS_NFC_TAG_READ " + str(message).encode("hex")
global force_freq
if force_freq:
cmd = cmd + " freq=" + force_freq
if "FAIL" in wpas.request(cmd):
return False
return True
def wpas_get_handover_req():
wpas = wpas_connect()
if (wpas == None):
return None
res = wpas.request("NFC_GET_HANDOVER_REQ NDEF P2P-CR").rstrip()
if "FAIL" in res:
return None
return res.decode("hex")
def wpas_get_handover_req_wps():
wpas = wpas_connect()
if (wpas == None):
return None
res = wpas.request("NFC_GET_HANDOVER_REQ NDEF WPS-CR").rstrip()
if "FAIL" in res:
return None
return res.decode("hex")
def wpas_get_handover_sel(tag=False):
wpas = wpas_connect()
if (wpas == None):
return None
if tag:
res = wpas.request("NFC_GET_HANDOVER_SEL NDEF P2P-CR-TAG").rstrip()
else:
res = wpas.request("NFC_GET_HANDOVER_SEL NDEF P2P-CR").rstrip()
if "FAIL" in res:
return None
return res.decode("hex")
def wpas_get_handover_sel_wps():
wpas = wpas_connect()
if (wpas == None):
return None
res = wpas.request("NFC_GET_HANDOVER_SEL NDEF WPS-CR");
if "FAIL" in res:
return None
return res.rstrip().decode("hex")
def wpas_report_handover(req, sel, type):
wpas = wpas_connect()
if (wpas == None):
return None
cmd = "NFC_REPORT_HANDOVER " + type + " P2P " + str(req).encode("hex") + " " + str(sel).encode("hex")
global force_freq
if force_freq:
cmd = cmd + " freq=" + force_freq
return wpas.request(cmd)
def wpas_report_handover_wsc(req, sel, type):
wpas = wpas_connect()
if (wpas == None):
return None
cmd = "NFC_REPORT_HANDOVER " + type + " WPS " + str(req).encode("hex") + " " + str(sel).encode("hex")
if force_freq:
cmd = cmd + " freq=" + force_freq
return wpas.request(cmd)
def p2p_handover_client(llc):
message = nfc.ndef.HandoverRequestMessage(version="1.2")
message.nonce = random.randint(0, 0xffff)
global include_p2p_req
if include_p2p_req:
data = wpas_get_handover_req()
if (data == None):
summary("Could not get handover request carrier record from wpa_supplicant")
return
print "Handover request carrier record from wpa_supplicant: " + data.encode("hex")
datamsg = nfc.ndef.Message(data)
message.add_carrier(datamsg[0], "active", datamsg[1:])
global include_wps_req
if include_wps_req:
print "Handover request (pre-WPS):"
try:
print message.pretty()
except Exception, e:
print e
data = wpas_get_handover_req_wps()
if data:
print "Add WPS request in addition to P2P"
datamsg = nfc.ndef.Message(data)
message.add_carrier(datamsg[0], "active", datamsg[1:])
print "Handover request:"
try:
print message.pretty()
except Exception, e:
print e
print str(message).encode("hex")
client = nfc.handover.HandoverClient(llc)
try:
summary("Trying to initiate NFC connection handover")
client.connect()
summary("Connected for handover")
except nfc.llcp.ConnectRefused:
summary("Handover connection refused")
client.close()
return
except Exception, e:
summary("Other exception: " + str(e))
client.close()
return
summary("Sending handover request")
if not client.send(message):
summary("Failed to send handover request")
client.close()
return
summary("Receiving handover response")
message = client._recv()
if message is None:
summary("No response received")
client.close()
return
if message.type != "urn:nfc:wkt:Hs":
summary("Response was not Hs - received: " + message.type)
client.close()
return
print "Received message"
try:
print message.pretty()
except Exception, e:
print e
print str(message).encode("hex")
message = nfc.ndef.HandoverSelectMessage(message)
summary("Handover select received")
try:
print message.pretty()
except Exception, e:
print e
for carrier in message.carriers:
print "Remote carrier type: " + carrier.type
if carrier.type == "application/vnd.wfa.p2p":
print "P2P carrier type match - send to wpa_supplicant"
if "OK" in wpas_report_handover(data, carrier.record, "INIT"):
success_report("P2P handover reported successfully (initiator)")
else:
summary("P2P handover report rejected")
break
print "Remove peer"
client.close()
print "Done with handover"
global only_one
if only_one:
print "only_one -> stop loop"
global continue_loop
continue_loop = False
global no_wait
if no_wait:
print "Trying to exit.."
global terminate_now
terminate_now = True
class HandoverServer(nfc.handover.HandoverServer):
def __init__(self, llc):
super(HandoverServer, self).__init__(llc)
self.sent_carrier = None
self.ho_server_processing = False
self.success = False
# override to avoid parser error in request/response.pretty() in nfcpy
# due to new WSC handover format
def _process_request(self, request):
summary("received handover request {}".format(request.type))
response = nfc.ndef.Message("\xd1\x02\x01Hs\x12")
if not request.type == 'urn:nfc:wkt:Hr':
summary("not a handover request")
else:
try:
request = nfc.ndef.HandoverRequestMessage(request)
except nfc.ndef.DecodeError as e:
summary("error decoding 'Hr' message: {}".format(e))
else:
response = self.process_request(request)
summary("send handover response {}".format(response.type))
return response
def process_request(self, request):
self.ho_server_processing = True
clear_raw_mode()
print "HandoverServer - request received"
try:
print "Parsed handover request: " + request.pretty()
except Exception, e:
print e
sel = nfc.ndef.HandoverSelectMessage(version="1.2")
found = False
for carrier in request.carriers:
print "Remote carrier type: " + carrier.type
if carrier.type == "application/vnd.wfa.p2p":
print "P2P carrier type match - add P2P carrier record"
found = True
self.received_carrier = carrier.record
print "Carrier record:"
try:
print carrier.record.pretty()
except Exception, e:
print e
data = wpas_get_handover_sel()
if data is None:
print "Could not get handover select carrier record from wpa_supplicant"
continue
print "Handover select carrier record from wpa_supplicant:"
print data.encode("hex")
self.sent_carrier = data
if "OK" in wpas_report_handover(self.received_carrier, self.sent_carrier, "RESP"):
success_report("P2P handover reported successfully (responder)")
else:
summary("P2P handover report rejected")
break
message = nfc.ndef.Message(data);
sel.add_carrier(message[0], "active", message[1:])
break
for carrier in request.carriers:
if found:
break
print "Remote carrier type: " + carrier.type
if carrier.type == "application/vnd.wfa.wsc":
print "WSC carrier type match - add WSC carrier record"
found = True
self.received_carrier = carrier.record
print "Carrier record:"
try:
print carrier.record.pretty()
except Exception, e:
print e
data = wpas_get_handover_sel_wps()
if data is None:
print "Could not get handover select carrier record from wpa_supplicant"
continue
print "Handover select carrier record from wpa_supplicant:"
print data.encode("hex")
self.sent_carrier = data
if "OK" in wpas_report_handover_wsc(self.received_carrier, self.sent_carrier, "RESP"):
success_report("WSC handover reported successfully")
else:
summary("WSC handover report rejected")
break
message = nfc.ndef.Message(data);
sel.add_carrier(message[0], "active", message[1:])
found = True
break
print "Handover select:"
try:
print sel.pretty()
except Exception, e:
print e
print str(sel).encode("hex")
summary("Sending handover select")
self.success = True
return sel
def clear_raw_mode():
import sys, tty, termios
global prev_tcgetattr, in_raw_mode
if not in_raw_mode:
return
fd = sys.stdin.fileno()
termios.tcsetattr(fd, termios.TCSADRAIN, prev_tcgetattr)
in_raw_mode = False
def getch():
import sys, tty, termios, select
global prev_tcgetattr, in_raw_mode
fd = sys.stdin.fileno()
prev_tcgetattr = termios.tcgetattr(fd)
ch = None
try:
tty.setraw(fd)
in_raw_mode = True
[i, o, e] = select.select([fd], [], [], 0.05)
if i:
ch = sys.stdin.read(1)
finally:
termios.tcsetattr(fd, termios.TCSADRAIN, prev_tcgetattr)
in_raw_mode = False
return ch
def p2p_tag_read(tag):
success = False
if len(tag.ndef.message):
for record in tag.ndef.message:
print "record type " + record.type
if record.type == "application/vnd.wfa.wsc":
summary("WPS tag - send to wpa_supplicant")
success = wpas_tag_read(tag.ndef.message)
break
if record.type == "application/vnd.wfa.p2p":
summary("P2P tag - send to wpa_supplicant")
success = wpas_tag_read(tag.ndef.message)
break
else:
summary("Empty tag")
if success:
success_report("Tag read succeeded")
return success
def rdwr_connected_p2p_write(tag):
summary("Tag found - writing - " + str(tag))
global p2p_sel_data
tag.ndef.message = str(p2p_sel_data)
success_report("Tag write succeeded")
print "Done - remove tag"
global only_one
if only_one:
global continue_loop
continue_loop = False
global p2p_sel_wait_remove
return p2p_sel_wait_remove
def wps_write_p2p_handover_sel(clf, wait_remove=True):
print "Write P2P handover select"
data = wpas_get_handover_sel(tag=True)
if (data == None):
summary("Could not get P2P handover select from wpa_supplicant")
return
global p2p_sel_wait_remove
p2p_sel_wait_remove = wait_remove
global p2p_sel_data
p2p_sel_data = nfc.ndef.HandoverSelectMessage(version="1.2")
message = nfc.ndef.Message(data);
p2p_sel_data.add_carrier(message[0], "active", message[1:])
print "Handover select:"
try:
print p2p_sel_data.pretty()
except Exception, e:
print e
print str(p2p_sel_data).encode("hex")
print "Touch an NFC tag"
clf.connect(rdwr={'on-connect': rdwr_connected_p2p_write})
def rdwr_connected(tag):
global only_one, no_wait
summary("Tag connected: " + str(tag))
if tag.ndef:
print "NDEF tag: " + tag.type
try:
print tag.ndef.message.pretty()
except Exception, e:
print e
success = p2p_tag_read(tag)
if only_one and success:
global continue_loop
continue_loop = False
else:
summary("Not an NDEF tag - remove tag")
return True
return not no_wait
def llcp_worker(llc):
global init_on_touch
if init_on_touch:
print "Starting handover client"
p2p_handover_client(llc)
return
global no_input
if no_input:
print "Wait for handover to complete"
else:
print "Wait for handover to complete - press 'i' to initiate ('w' for WPS only, 'p' for P2P only)"
global srv
global wait_connection
while not wait_connection and srv.sent_carrier is None:
if srv.ho_server_processing:
time.sleep(0.025)
elif no_input:
time.sleep(0.5)
else:
global include_wps_req, include_p2p_req
res = getch()
if res == 'i':
include_wps_req = True
include_p2p_req = True
elif res == 'p':
include_wps_req = False
include_p2p_req = True
elif res == 'w':
include_wps_req = True
include_p2p_req = False
else:
continue
clear_raw_mode()
print "Starting handover client"
p2p_handover_client(llc)
return
clear_raw_mode()
print "Exiting llcp_worker thread"
def llcp_startup(clf, llc):
print "Start LLCP server"
global srv
srv = HandoverServer(llc)
return llc
def llcp_connected(llc):
print "P2P LLCP connected"
global wait_connection
wait_connection = False
global init_on_touch
if not init_on_touch:
global srv
srv.start()
if init_on_touch or not no_input:
threading.Thread(target=llcp_worker, args=(llc,)).start()
return True
def terminate_loop():
global terminate_now
return terminate_now
def main():
clf = nfc.ContactlessFrontend()
parser = argparse.ArgumentParser(description='nfcpy to wpa_supplicant integration for P2P and WPS NFC operations')
parser.add_argument('-d', const=logging.DEBUG, default=logging.INFO,
action='store_const', dest='loglevel',
help='verbose debug output')
parser.add_argument('-q', const=logging.WARNING, action='store_const',
dest='loglevel', help='be quiet')
parser.add_argument('--only-one', '-1', action='store_true',
help='run only one operation and exit')
parser.add_argument('--init-on-touch', '-I', action='store_true',
help='initiate handover on touch')
parser.add_argument('--no-wait', action='store_true',
help='do not wait for tag to be removed before exiting')
parser.add_argument('--ifname', '-i',
help='network interface name')
parser.add_argument('--no-wps-req', '-N', action='store_true',
help='do not include WPS carrier record in request')
parser.add_argument('--no-input', '-a', action='store_true',
help='do not use stdout input to initiate handover')
parser.add_argument('--tag-read-only', '-t', action='store_true',
help='tag read only (do not allow connection handover)')
parser.add_argument('--handover-only', action='store_true',
help='connection handover only (do not allow tag read)')
parser.add_argument('--freq', '-f',
help='forced frequency of operating channel in MHz')
parser.add_argument('--summary',
help='summary file for writing status updates')
parser.add_argument('--success',
help='success file for writing success update')
parser.add_argument('command', choices=['write-p2p-sel'],
nargs='?')
args = parser.parse_args()
global only_one
only_one = args.only_one
global no_wait
no_wait = args.no_wait
global force_freq
force_freq = args.freq
logging.basicConfig(level=args.loglevel)
global init_on_touch
init_on_touch = args.init_on_touch
if args.ifname:
global ifname
ifname = args.ifname
print "Selected ifname " + ifname
if args.no_wps_req:
global include_wps_req
include_wps_req = False
if args.summary:
global summary_file
summary_file = args.summary
if args.success:
global success_file
success_file = args.success
if args.no_input:
global no_input
no_input = True
clf = nfc.ContactlessFrontend()
global wait_connection
try:
if not clf.open("usb"):
print "Could not open connection with an NFC device"
raise SystemExit
if args.command == "write-p2p-sel":
wps_write_p2p_handover_sel(clf, wait_remove=not args.no_wait)
raise SystemExit
global continue_loop
while continue_loop:
print "Waiting for a tag or peer to be touched"
wait_connection = True
try:
if args.tag_read_only:
if not clf.connect(rdwr={'on-connect': rdwr_connected}):
break
elif args.handover_only:
if not clf.connect(llcp={'on-startup': llcp_startup,
'on-connect': llcp_connected},
terminate=terminate_loop):
break
else:
if not clf.connect(rdwr={'on-connect': rdwr_connected},
llcp={'on-startup': llcp_startup,
'on-connect': llcp_connected},
terminate=terminate_loop):
break
except Exception, e:
print "clf.connect failed"
global srv
if only_one and srv and srv.success:
raise SystemExit
except KeyboardInterrupt:
raise SystemExit
finally:
clf.close()
raise SystemExit
if __name__ == '__main__':
main()