hostapd/wps-ap-nfc.py

   1 #!/usr/bin/python
   2 #
   3 # Example nfcpy to hostapd wrapper for WPS NFC operations
   4 # Copyright (c) 2012-2013, 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 logging
  19 logging.basicConfig()
  20
  21 import wpactrl
  22
  23 wpas_ctrl = '/var/run/hostapd'
  24
  25 def wpas_connect():
  26     ifaces = []
  27     if os.path.isdir(wpas_ctrl):
  28         try:
  29             ifaces = [os.path.join(wpas_ctrl, i) for i in os.listdir(wpas_ctrl)]
  30         except OSError, error:
  31             print "Could not find hostapd: ", error
  32             return None
  33
  34     if len(ifaces) < 1:
  35         print "No hostapd control interface found"
  36         return None
  37
  38     for ctrl in ifaces:
  39         try:
  40             wpas = wpactrl.WPACtrl(ctrl)
  41             return wpas
  42         except wpactrl.error, error:
  43             print "Error: ", error
  44             pass
  45     return None
  46
  47
  48 def wpas_tag_read(message):
  49     wpas = wpas_connect()
  50     if (wpas == None):
  51         return
  52     print wpas.request("WPS_NFC_TAG_READ " + message.encode("hex"))
  53
  54
  55 def wpas_get_config_token():
  56     wpas = wpas_connect()
  57     if (wpas == None):
  58         return None
  59     return wpas.request("WPS_NFC_CONFIG_TOKEN NDEF").rstrip().decode("hex")
  60
  61
  62 def wpas_get_password_token():
  63     wpas = wpas_connect()
  64     if (wpas == None):
  65         return None
  66     return wpas.request("WPS_NFC_TOKEN NDEF").rstrip().decode("hex")
  67
  68
  69 def wpas_get_handover_req():
  70     wpas = wpas_connect()
  71     if (wpas == None):
  72         return None
  73     return wpas.request("NFC_GET_HANDOVER_REQ NDEF WPS").rstrip().decode("hex")
  74
  75
  76 def wpas_put_handover_sel(message):
  77     wpas = wpas_connect()
  78     if (wpas == None):
  79         return
  80     print wpas.request("NFC_RX_HANDOVER_SEL " + str(message).encode("hex"))
  81
  82
  83 def wps_handover_init(peer):
  84     print "Trying to initiate WPS handover"
  85
  86     data = wpas_get_handover_req()
  87     if (data == None):
  88         print "Could not get handover request message from hostapd"
  89         return
  90     print "Handover request from hostapd: " + data.encode("hex")
  91     message = nfc.ndef.Message(data)
  92     print "Parsed handover request: " + message.pretty()
  93
  94     nfc.llcp.activate(peer);
  95     time.sleep(0.5)
  96
  97     client = nfc.handover.HandoverClient()
  98     try:
  99         print "Trying handover";
 100         client.connect()
 101         print "Connected for handover"
 102     except nfc.llcp.ConnectRefused:
 103         print "Handover connection refused"
 104         nfc.llcp.shutdown()
 105         client.close()
 106         return
 107
 108     print "Sending handover request"
 109
 110     if not client.send(message):
 111         print "Failed to send handover request"
 112
 113     print "Receiving handover response"
 114     message = client._recv()
 115     print "Handover select received"
 116     print message.pretty()
 117     wpas_put_handover_sel(message)
 118
 119     print "Remove peer"
 120     nfc.llcp.shutdown()
 121     client.close()
 122     print "Done with handover"
 123
 124
 125 def wps_tag_read(tag):
 126     if len(tag.ndef.message):
 127         message = nfc.ndef.Message(tag.ndef.message)
 128         print "message type " + message.type
 129
 130         for record in message:
 131             print "record type " + record.type
 132             if record.type == "application/vnd.wfa.wsc":
 133                 print "WPS tag - send to hostapd"
 134                 wpas_tag_read(tag.ndef.message)
 135                 break
 136     else:
 137         print "Empty tag"
 138
 139     print "Remove tag"
 140     while tag.is_present:
 141         time.sleep(0.1)
 142
 143
 144 def wps_write_config_tag(clf):
 145     print "Write WPS config token"
 146     data = wpas_get_config_token()
 147     if (data == None):
 148         print "Could not get WPS config token from hostapd"
 149         return
 150
 151     print "Touch an NFC tag"
 152     while True:
 153         tag = clf.poll()
 154         if tag == None:
 155             time.sleep(0.1)
 156             continue
 157         break
 158
 159     print "Tag found - writing"
 160     tag.ndef.message = data
 161     print "Done - remove tag"
 162     while tag.is_present:
 163         time.sleep(0.1)
 164
 165
 166 def wps_write_password_tag(clf):
 167     print "Write WPS password token"
 168     data = wpas_get_password_token()
 169     if (data == None):
 170         print "Could not get WPS password token from hostapd"
 171         return
 172
 173     print "Touch an NFC tag"
 174     while True:
 175         tag = clf.poll()
 176         if tag == None:
 177             time.sleep(0.1)
 178             continue
 179         break
 180
 181     print "Tag found - writing"
 182     tag.ndef.message = data
 183     print "Done - remove tag"
 184     while tag.is_present:
 185         time.sleep(0.1)
 186
 187
 188 def main():
 189     clf = nfc.ContactlessFrontend()
 190
 191     try:
 192         if len(sys.argv) > 1 and sys.argv[1] == "write-config":
 193             wps_write_config_tag(clf)
 194             raise SystemExit
 195
 196         if len(sys.argv) > 1 and sys.argv[1] == "write-password":
 197             wps_write_password_tag(clf)
 198             raise SystemExit
 199
 200         while True:
 201             print "Waiting for a tag or peer to be touched"
 202
 203             while True:
 204                 general_bytes = nfc.llcp.startup({})
 205                 tag = clf.poll(general_bytes)
 206                 if tag == None:
 207                     continue
 208
 209                 if isinstance(tag, nfc.DEP):
 210                     wps_handover_init(tag)
 211                     break
 212
 213                 if tag.ndef:
 214                     wps_tag_read(tag)
 215                     break
 216
 217                 if tag:
 218                     print "Not an NDEF tag - remove tag"
 219                     while tag.is_present:
 220                         time.sleep(0.1)
 221                     break
 222
 223     except KeyboardInterrupt:
 224         raise SystemExit
 225     finally:
 226         clf.close()
 227
 228     raise SystemExit
 229
 230 if __name__ == '__main__':
 231     main()