#!/usr/bin/python
#
# Example nfcpy to hostapd wrapper for WPS 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 argparse
import nfc
import nfc.ndef
import nfc.llcp
import nfc.handover
import logging
import wpaspy
wpas_ctrl = '/var/run/hostapd'
continue_loop = True
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 hostapd: ", error
return None
if len(ifaces) < 1:
print "No hostapd control interface found"
return None
for ctrl in ifaces:
try:
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
if "FAIL" in wpas.request("WPS_NFC_TAG_READ " + str(message).encode("hex")):
return False
return True
def wpas_get_config_token():
wpas = wpas_connect()
if (wpas == None):
return None
ret = wpas.request("WPS_NFC_CONFIG_TOKEN NDEF")
if "FAIL" in ret:
return None
return ret.rstrip().decode("hex")
def wpas_get_password_token():
wpas = wpas_connect()
if (wpas == None):
return None
ret = wpas.request("WPS_NFC_TOKEN NDEF")
if "FAIL" in ret:
return None
return ret.rstrip().decode("hex")
def wpas_get_handover_sel():
wpas = wpas_connect()
if (wpas == None):
return None
ret = wpas.request("NFC_GET_HANDOVER_SEL NDEF WPS-CR")
if "FAIL" in ret:
return None
return ret.rstrip().decode("hex")
def wpas_report_handover(req, sel):
wpas = wpas_connect()
if (wpas == None):
return None
return wpas.request("NFC_REPORT_HANDOVER RESP WPS " +
str(req).encode("hex") + " " +
str(sel).encode("hex"))
class HandoverServer(nfc.handover.HandoverServer):
def __init__(self, llc):
super(HandoverServer, self).__init__(llc)
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):
summary("HandoverServer - request received")
try:
print "Parsed handover request: " + request.pretty()
except Exception, e:
print e
print str(request).encode("hex")
sel = nfc.ndef.HandoverSelectMessage(version="1.2")
for carrier in request.carriers:
print "Remote carrier type: " + carrier.type
if carrier.type == "application/vnd.wfa.wsc":
summary("WPS carrier type match - add WPS carrier record")
data = wpas_get_handover_sel()
if data is None:
summary("Could not get handover select carrier record from hostapd")
continue
print "Handover select carrier record from hostapd:"
print data.encode("hex")
if "OK" in wpas_report_handover(carrier.record, data):
success_report("Handover reported successfully")
else:
summary("Handover report rejected")
message = nfc.ndef.Message(data);
sel.add_carrier(message[0], "active", message[1:])
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 wps_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 hostapd")
success = wpas_tag_read(tag.ndef.message)
break
else:
summary("Empty tag")
if success:
success_report("Tag read succeeded")
return success
def rdwr_connected_write(tag):
summary("Tag found - writing - " + str(tag))
global write_data
tag.ndef.message = str(write_data)
success_report("Tag write succeeded")
print "Done - remove tag"
global only_one
if only_one:
global continue_loop
continue_loop = False
global write_wait_remove
while write_wait_remove and tag.is_present:
time.sleep(0.1)
def wps_write_config_tag(clf, wait_remove=True):
summary("Write WPS config token")
global write_data, write_wait_remove
write_wait_remove = wait_remove
write_data = wpas_get_config_token()
if write_data == None:
summary("Could not get WPS config token from hostapd")
return
print "Touch an NFC tag"
clf.connect(rdwr={'on-connect': rdwr_connected_write})
def wps_write_password_tag(clf, wait_remove=True):
summary("Write WPS password token")
global write_data, write_wait_remove
write_wait_remove = wait_remove
write_data = wpas_get_password_token()
if write_data == None:
summary("Could not get WPS password token from hostapd")
return
print "Touch an NFC tag"
clf.connect(rdwr={'on-connect': rdwr_connected_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 = wps_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_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 srv
srv.start()
return True
def main():
clf = nfc.ContactlessFrontend()
parser = argparse.ArgumentParser(description='nfcpy to hostapd integration for 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('--no-wait', action='store_true',
help='do not wait for tag to be removed before exiting')
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-config',
'write-password'],
nargs='?')
args = parser.parse_args()
global only_one
only_one = args.only_one
global no_wait
no_wait = args.no_wait
if args.summary:
global summary_file
summary_file = args.summary
if args.success:
global success_file
success_file = args.success
logging.basicConfig(level=args.loglevel)
try:
if not clf.open("usb"):
print "Could not open connection with an NFC device"
raise SystemExit
if args.command == "write-config":
wps_write_config_tag(clf, wait_remove=not args.no_wait)
raise SystemExit
if args.command == "write-password":
wps_write_password_tag(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 not clf.connect(rdwr={'on-connect': rdwr_connected},
llcp={'on-startup': llcp_startup,
'on-connect': llcp_connected}):
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()