contrib/wpa/wpa_supplicant/examples/wps-nfc.py

   1 #!/usr/bin/python
   2 #
   3 # Example nfcpy to wpa_supplicant wrapper for WPS NFC operations
   4 # Copyright (c) 2012, Jouni Malinen <j@w1.fi>
   5 #
   6 # This software may be distributed under the terms of the BSD license.
   7 # See README for more details.
   8
   9 import os
  10 import sys
  11 import time
  12
  13 import nfc
  14 import nfc.ndef
  15 import nfc.llcp
  16 import nfc.handover
  17
  18 import wpactrl
  19
  20 wpas_ctrl = '/var/run/wpa_supplicant'
  21
  22 def wpas_connect():
  23     ifaces = []
  24     if os.path.isdir(wpas_ctrl):
  25         try:
  26             ifaces = [os.path.join(wpas_ctrl, i) for i in os.listdir(wpas_ctrl)]
  27         except OSError, error:
  28             print "Could not find wpa_supplicant: ", error
  29             return None
  30
  31     if len(ifaces) < 1:
  32         print "No wpa_supplicant control interface found"
  33         return None
  34
  35     for ctrl in ifaces:
  36         try:
  37             wpas = wpactrl.WPACtrl(ctrl)
  38             return wpas
  39         except wpactrl.error, error:
  40             print "Error: ", error
  41             pass
  42     return None
  43
  44
  45 def wpas_tag_read(message):
  46     wpas = wpas_connect()
  47     if (wpas == None):
  48         return
  49     print wpas.request("WPS_NFC_TAG_READ " + message.encode("hex"))
  50
  51
  52 def wpas_get_handover_req():
  53     wpas = wpas_connect()
  54     if (wpas == None):
  55         return None
  56     return wpas.request("NFC_GET_HANDOVER_REQ NDEF WPS").rstrip().decode("hex")
  57
  58
  59 def wpas_put_handover_sel(message):
  60     wpas = wpas_connect()
  61     if (wpas == None):
  62         return
  63     print wpas.request("NFC_RX_HANDOVER_SEL " + str(message).encode("hex"))
  64
  65
  66 def wps_handover_init(peer):
  67     print "Trying to initiate WPS handover"
  68
  69     data = wpas_get_handover_req()
  70     if (data == None):
  71         print "Could not get handover request message from wpa_supplicant"
  72         return
  73     print "Handover request from wpa_supplicant: " + data.encode("hex")
  74     message = nfc.ndef.Message(data)
  75     print "Parsed handover request: " + message.pretty()
  76
  77     nfc.llcp.activate(peer);
  78     time.sleep(0.5)
  79
  80     client = nfc.handover.HandoverClient()
  81     try:
  82         print "Trying handover";
  83         client.connect()
  84         print "Connected for handover"
  85     except nfc.llcp.ConnectRefused:
  86         print "Handover connection refused"
  87         nfc.llcp.shutdown()
  88         client.close()
  89         return
  90
  91     print "Sending handover request"
  92
  93     if not client.send(message):
  94         print "Failed to send handover request"
  95
  96     print "Receiving handover response"
  97     message = client._recv()
  98     print "Handover select received"
  99     print message.pretty()
 100     wpas_put_handover_sel(message)
 101
 102     print "Remove peer"
 103     nfc.llcp.shutdown()
 104     client.close()
 105     print "Done with handover"
 106
 107
 108 def wps_tag_read(tag):
 109     if len(tag.ndef.message):
 110         message = nfc.ndef.Message(tag.ndef.message)
 111         print "message type " + message.type
 112
 113         for record in message:
 114             print "record type " + record.type
 115             if record.type == "application/vnd.wfa.wsc":
 116                 print "WPS tag - send to wpa_supplicant"
 117                 wpas_tag_read(tag.ndef.message)
 118                 break
 119     else:
 120         print "Empty tag"
 121
 122     print "Remove tag"
 123     while tag.is_present:
 124         time.sleep(0.1)
 125
 126
 127 def main():
 128     clf = nfc.ContactlessFrontend()
 129
 130     try:
 131         while True:
 132             print "Waiting for a tag or peer to be touched"
 133
 134             while True:
 135                 general_bytes = nfc.llcp.startup({})
 136                 tag = clf.poll(general_bytes)
 137                 if tag == None:
 138                     continue
 139
 140                 if isinstance(tag, nfc.DEP):
 141                     wps_handover_init(tag)
 142                     break
 143
 144                 if tag.ndef:
 145                     wps_tag_read(tag)
 146                     break
 147
 148                 if tag:
 149                     print "Not an NDEF tag - remove tag"
 150                     while tag.is_present:
 151                         time.sleep(0.1)
 152                     break
 153
 154     except KeyboardInterrupt:
 155         raise SystemExit
 156     finally:
 157         clf.close()
 158
 159     raise SystemExit
 160
 161 if __name__ == '__main__':
 162     main()