def setChannel(self, channel):
freq = self.wifi_helper.translateChannelToFrequency(channel)
if freq !=0:
self.processingChangeKeysEvent.wait()
self.sendingUserCtrlMessageEvent.wait()
self.processingNeighborUpdateEvent.wait()
#while((int(time.time()) - self.globalNeighborList[self.hostname].timestampLastKCM) < config.CHANNEL_SWITCH_GUARD) or ((int(time.time()) - self.globalNeighborList[self.hostname].timestampLastKCM) > (config.KEYCHANGEINTERVAL-config.CHANNEL_SWITCH_GUARD)):
self.channel_switch_helper = ChannelSwitchGuardThread()
self.channel_switch_helper.run(self.globalNeighborList[self.hostname].timestampLastKCM, config.CHANNEL_SWITCH_GUARD, config.KEYCHANGEINTERVAL, freq, channel, self.connector.setChannel, self.setChannelFinished, self.channel, self.freq)
self.channel = channel
self.freq = freq
return True
else:
raise Exception("Unsupported Channel: " + str(channel))
def setChannel(self, channel):
freq = self.wifi_helper.translateChannelToFrequency(channel)
if freq !=0:
self.processingChangeKeysEvent.wait()
self.sendingUserCtrlMessageEvent.wait()
self.processingNeighborUpdateEvent.wait()
#while((int(time.time()) - self.globalNeighborList[self.hostname].timestampLastKCM) < config.CHANNEL_SWITCH_GUARD) or ((int(time.time()) - self.globalNeighborList[self.hostname].timestampLastKCM) > (config.KEYCHANGEINTERVAL-config.CHANNEL_SWITCH_GUARD)):
self.channel_switch_helper = ChannelSwitchGuardThread()
self.channel_switch_helper.run(self.globalNeighborList[self.hostname].timestampLastKCM, config.CHANNEL_SWITCH_GUARD, config.KEYCHANGEINTERVAL, freq, channel, self.connector.setChannel, self.setChannelFinished, self.channel, self.freq)
self.channel = channel
self.freq = freq
return True
else:
raise Exception("Unsupported Channel: " + str(channel))
class ResFiAgent(ResFiNorthBoundAPI):
def __init__(self, log):
self.log = log
self.debug = config.DEBUG
self.lostMessages = 0 # TODO: do we need this?
# use the proper connector module
if config.CONNECTOR == "mininet":
self.connector = MininetConnector(log)
elif config.CONNECTOR == "linux":
self.connector = LinuxConnector(log)
# Helper Objects
self.wifi_helper = WiFiHelper(log)
self.network_helper = NetworkHelper(log)
self.security_helper = SecurityHelper(log)
self.parsing_helper = ParsingHelper(log)
# Config
self.FWD_PORT = config.FWD_PORT
self.SND_PORT = config.SND_PORT
self.SLEEP_DUR = config.SLEEP_DUR
self.keyChangeInterval = config.KEYCHANGEINTERVAL
#Internal RX Callback
self.rx_cb = self.rxCbInternal
#Init thread handling objects
self.init_thread_handling()
self.init_local_credentials()
self.init_security_credentials()
self.connector.addIEtoProbeResponses(self.pubKeyHexStr, self.keyHexStr, self.ivHexStr, self.hostnameStrHex)
self.initSendMsg()
# ResFi forwarding thread
fwd_t = threading.Thread(name='initForwarding', target=self.initForwardingTTL)
fwd_t.setDaemon(True)
fwd_t.start()
time.sleep(1)
self.init_self_connection()
scanResults = self.connector.performActiveScan(True, "", 0, self.pubKeyHexStr, self.keyHexStr, self.ivHexStr, self.hostnameStrHex, self.freq)
self.onAPJoined(scanResults)
# thread responsible for handling probe requests received by hostapd, takes callback for probe request handling
probereq_t = threading.Thread(name='subscribeToProbeRequests', target=self.connector.subscribeToProbeRequests, args=(self.handle_incoming_probe_requests,))
probereq_t.setDaemon(True)
probereq_t.start()
# receive message thread
sub_t = threading.Thread(name='receiveMessage', target=self.receiveMessage, args=(self.rx_cb,))
sub_t.setDaemon(True)
sub_t.start()
# periodic key changing
keychanger_t = threading.Thread(name='changeKeys', target=self.changeKeys)
keychanger_t.setDaemon(True)
keychanger_t.start()
"""
Init local credentials, e.g. AP params, interfaces
"""
def init_local_credentials(self):
#Initialize neighborList dict
self.globalNeighborList = {}
#Initialize appList dict
self.globalAppList = {}
self.publicInterface = self.connector.getWiredInterface()
self.hostname = self.connector.getHostname()
self.hostnameStrHex = self.hostname.encode("hex")
self.ifs = self.connector.getInterfaceList()
self.ips = self.connector.getIPList()
self.log.info("ResFi: IPS: %s" % str(self.ips))
self.log.info("ResFi: IFS: %s" % str(self.ifs))
self.log.info("ResFi: Hostname: %s" % str(self.hostname))
self.apParams = self.connector.getAPparams()
self.channel = self.apParams['channel']
self.freq = self.apParams['freq']
self.bssid = self.apParams['bssid']
self.ssid = self.apParams['ssid']
self.log.info("ResFi: BSSID: %s SSID: %s Channel: %s Frequency: %s" % (str(self.bssid), str(self.ssid), str(self.channel), str(self.freq)))
"""
Init thread_handling, e.g. event variables ...
"""
def init_thread_handling(self):
#Thread Handling
self.processingProbeRequestEvent = threading.Event()
self.processingChangeKeysEvent = threading.Event()
self.sendingUserSpaceMessageEvent = threading.Event()
self.sendingUserCtrlMessageEvent = threading.Event()
self.processingNeighborUpdateEvent = threading.Event()
self.processingNeighborMessageEvent = threading.Event()
self.processingChannelSwitchEvent = threading.Event()
self.processingProbeRequestEvent.set()
self.processingChangeKeysEvent.set()
self.sendingUserSpaceMessageEvent.set()
self.sendingUserCtrlMessageEvent.set()
self.processingNeighborUpdateEvent.set()
self.processingNeighborMessageEvent.set()
self.processingChannelSwitchEvent.set()
"""
Init security credentials, e.g. security keys, self connection, ...
"""
def init_security_credentials(self):
self.init_public_security_credentials()
self.init_symmetric_security_credentials()
def init_public_security_credentials(self):
#RSA Keys
self.rsaKey = RSA.generate(1024, os.urandom)
self.pubKey = self.rsaKey.publickey()
self.pubKeyHexStr = self.pubKey.exportKey('DER').encode("hex")
def init_symmetric_security_credentials(self):
#AES Keys
keys = self.security_helper.generateSymmetricKeys()
self.key = keys['key']
self.keyHexStr = keys['keyHexStr']
self.iv = keys['iv']
self.ivHexStr = keys['ivHexStr']
"""
Init self connection
"""
def init_self_connection(self):
#Add myself to neighbors
ownNeighborEntry = Neighbor()
ownNeighborEntry.ipAddress = self.hostname
ownNeighborEntry.encryptionKey = self.key
ownNeighborEntry.encryptionIV = self.iv
#Connect to own socket
tempNeighborList = {}
tempNeighborList[self.hostname] = ownNeighborEntry
self.onAPJoined(tempNeighborList)
"""
Forwarding while considering TTL, packet ID, ...
"""
def initForwardingTTL(self):
self.log.debug('initForwarding_ttl')
try:
context = zmq.Context(1)
# Socket facing clients
self.frontend = context.socket(zmq.SUB)
self.frontend.setsockopt(zmq.SUBSCRIBE, "")
# Socket facing services
self.backend = context.socket(zmq.PUB)
self.backend.bind("tcp://*:%s" % self.FWD_PORT)
fwd_cache = {}
while True:
json_data = self.frontend.recv_json()
# update ttl
json_data['ttl'] = int(json_data['ttl']) - 1
if json_data['ttl'] <= 0:
time.sleep(self.SLEEP_DUR)
continue
if json_data['host'] in fwd_cache and fwd_cache[json_data['host']] >= json_data['id']:
time.sleep(self.SLEEP_DUR)
continue
if json_data['host'] != self.hostname and json_data['rec'] != "255.255.255.255" and json_data['rec'] != self.hostname:
time.sleep(self.SLEEP_DUR)
continue
self.log.debug("Forwarder received message...")
self.log.debug("Forwarder waiting for ProbeRequestevent..")
self.processingProbeRequestEvent.wait()
self.log.debug("Forwarder waiting for ProcessingChangeKeysEvent..")
self.processingChangeKeysEvent.wait()
self.log.debug("Forwarder waiting for ProcessingNeighborUpdateEvent..")
self.processingNeighborUpdateEvent.wait()
self.log.debug("Forwarder is running...")
if json_data['host'] != self.hostname:
isNeighborMessage = True
self.log.debug("Forwarder is handling Message from Neighbor: %s original sender: %s" % (str(json_data['lasthop']), str(json_data['host'])))
self.processingNeighborMessageEvent.clear()
else:
isNeighborMessage = False
self.log.debug("Forwarder is handling own outgoing Message: %s original sender: %s" % (str(json_data['lasthop']), str(json_data['host'])))
if (json_data['lasthop'] in self.globalNeighborList):
lasthop_key = self.globalNeighborList[json_data['lasthop']].encryptionKey
lasthop_iv = self.globalNeighborList[json_data['lasthop']].encryptionIV
if json_data['lasthop'] != self.hostname and json_data['lasthop'] != 'old_keys':
pubKey = self.globalNeighborList[json_data['lasthop']].pubKey
else:
pubKey = self.rsaKey
lasthop_aes = AES.new(lasthop_key, AES.MODE_CFB, lasthop_iv)
enc_message_byte = base64.decodestring(json_data['msg'])
plain_msg = lasthop_aes.decrypt(enc_message_byte)
self.log.debug("From: %s" % str(json_data['lasthop']))
sig = json_data['sig']
success = False
if not self.security_helper.verify_signature(sig, plain_msg, pubKey):
self.log.debug("Signature mismatch trying with old keys if possible...")
if isNeighborMessage == False:
self.log.debug("Decrypting own message failed....")
self.sendingUserSpaceMessageEvent.set()
self.sendingUserCtrlMessageEvent.set()
continue
if self.globalNeighborList[json_data['lasthop']].oldEncryptionKey != 0 and self.globalNeighborList[json_data['lasthop']].oldEncryptionIV != 0:
lasthop_aes = AES.new(self.globalNeighborList[json_data['lasthop']].oldEncryptionKey, AES.MODE_CFB, self.globalNeighborList[json_data['lasthop']].oldEncryptionIV)
enc_message_byte = base64.decodestring(json_data['msg'])
plain_msg = lasthop_aes.decrypt(enc_message_byte)
#print "Message old key try: "+str(plain_msg)+ " From: "+str(json_data['lasthop'])
sig = json_data['sig']
if not self.security_helper.verify_signature(sig, plain_msg, pubKey):
success = False
self.log.debug("Decrypting with old keys failed")
else:
success = True
self.log.debug("Old keys worked")
else:
success = False
self.log.debug("No old keys available")
if success == False:
self.log.debug("No Old keys available or signature mismatch with old keys...")
self.log.debug("Trying to pause neighbor message processing to allow finishing of KCM process...")
self.processingNeighborMessageEvent.set()
#self.sendingUserSpaceMessageEvent.wait()
#self.sendingUserCtrlMessageEvent.wait()
self.processingNeighborUpdateEvent.wait()
self.processingProbeRequestEvent.wait()
self.processingChangeKeysEvent.wait()
self.processingNeighborMessageEvent.clear()
self.log.debug("Now trying again with hopefully new keys....")
lasthop_aes = AES.new(lasthop_key, AES.MODE_CFB, lasthop_iv)
enc_message_byte = base64.decodestring(json_data['msg'])
plain_msg = lasthop_aes.decrypt(enc_message_byte)
sig = json_data['sig']
if not self.security_helper.verify_signature(sig, plain_msg, pubKey):
self.globalNeighborList[json_data['lasthop']].lostMessages = self.globalNeighborList[json_data['lasthop']].lostMessages + 1
self.globalNeighborList[json_data['lasthop']].rxStatsLost = self.globalNeighborList[json_data['lasthop']].rxStatsLost + 1
self.log.debug("Lost Messages Counter: %s" % str(self.globalNeighborList[json_data['lasthop']].lostMessages))
self.log.debug("Lost Messages Overall: %s" % str(self.globalNeighborList[json_data['lasthop']].rxStatsLost))
self.log.debug("Overall Messages Received from Neighbor: %s" % str(self.globalNeighborList[json_data['lasthop']].rxStatsSuccess))
if self.globalNeighborList[json_data['lasthop']].lostMessages >= 5:
self.log.debug("Decrypting of neighbor messages failed %s times, trying to rescan neighbor" % (str(self.globalNeighborList[json_data['lasthop']].lostMessages)))
self.globalNeighborList[json_data['lasthop']].lostMessages = 0
if self.globalNeighborList[json_data['lasthop']].freq != 0:
self.log.debug("Trying Rescanning Neighbor, waiting for other KCM processes...")
self.processingNeighborMessageEvent.set()
self.processingNeighborUpdateEvent.wait()
self.processingProbeRequestEvent.wait()
self.processingChangeKeysEvent.wait()
self.processingNeighborUpdateEvent.clear()
freq = self.globalNeighborList[json_data['lasthop']].freq
ssid = self.globalNeighborList[json_data["lasthop"]].ssid
self.rescan_neighbor(freq, ssid, json_data['lasthop'], 10)
self.processingNeighborUpdateEvent.set()
continue
#self.processingNeighborMessageEvent.set()
else:
self.log.debug("No frequency or SSID of neighbor available")
self.onAPLeft(json_data['lasthop'], "No frequency or SSID of neighbor available")
self.processingNeighborMessageEvent.set()
continue
else:
self.processingNeighborMessageEvent.set()
continue
if json_data['lasthop'] == 'old_keys':
sendKey=lasthop_key
sendIv=lasthop_iv
else:
sendKey=self.key
sendIv=self.iv
#append own signature
sig = self.security_helper.create_signature(plain_msg, self.rsaKey)
json_data['sig'] = sig
# encrypt with my own key
aes = AES.new(sendKey, AES.MODE_CFB, sendIv)
new_message = aes.encrypt(plain_msg)
new_message_b64 = base64.encodestring(new_message)
json_data['msg'] = new_message_b64
if isNeighborMessage == True:
self.log.debug("Resetting lost messages counter of neighbor")
self.globalNeighborList[json_data['lasthop']].lostMessages = 0
self.log.debug("Incrementing overall neighbor messsage cntr")
self.globalNeighborList[json_data['lasthop']].rxStatsSuccess = self.globalNeighborList[json_data['lasthop']].rxStatsSuccess + 1
# update last hop
json_data['lasthop'] = self.hostname
self.backend.send_json(json_data)
fwd_cache[json_data['host']] = json_data['id']
if json_data['host'] == self.hostname:#
self.log.debug("Forwarder: Own Message sent from: %s" % str(json_data['lasthop']))
self.sendingUserSpaceMessageEvent.set()
self.sendingUserCtrlMessageEvent.set()
else:
self.log.debug("Forwarder: Neighbor Message forwarded from: %s" % str(json_data['lasthop']))
time.sleep(self.SLEEP_DUR)
else:
self.log.debug("fwd::cannot decode from %s; drop message" % (json_data['host']))
except Exception as e:
traceback.print_exc()
self.log.error("bringing down zmq device %s" % str(sys.exc_info()[0]))
finally:
pass
self.frontend.close()
self.backend.close()
context.term()
"""
Example message source to be disseminated
"""
def initSendMsg(self):
self.log.debug('initSendMsg')
context = zmq.Context()
self.snd_socket = context.socket(zmq.PUB)
self.snd_socket.bind("tcp://*:%s" % self.SND_PORT)
self.local_id = 1
"""
Receive Probe Requests from hostapd and handle them
"""
def handle_incoming_probe_requests(self, payload, rssi):
self.log.debug("ResFi: handle_incoming_probe_requests")
self.log.debug("ResFi: payload: %s" % payload )
if 'B16B00B5' in payload:
resfiIe = payload.split('B16B00B5',2)[1]
resfiIe = resfiIe.replace('DD06', '')
resfiFreq = payload.split('B16B00B5',2)[2]
freq = int(resfiFreq)
self.log.info("ResFi: resfiFreq: %s" % str(freq) )
self.log.debug("ResFi: Incoming ResFi Probe Request")
self.log.debug(resfiIe)
self.processingChangeKeysEvent.wait()
self.processingNeighborUpdateEvent.wait()
self.sendingUserSpaceMessageEvent.wait()
self.sendingUserCtrlMessageEvent.wait()
self.processingProbeRequestEvent.clear()
newNeighbor = self.parsing_helper.parse_resfi_ie(resfiIe, len(self.keyHexStr), len(self.ivHexStr), len(self.pubKeyHexStr), int(rssi), 0, freq, 0)
neighborList = {}
neighborList[newNeighbor.ipAddress] = newNeighbor
self.onAPJoined(neighborList)
self.processingProbeRequestEvent.set()
# # self.keyLock.release()
#print"Receive Probe Requests Thread Released # # self.keyLock.release()"
else:
for ns in self.globalAppList:
self.globalAppList[ns].probeReqRec_cb(payload, rssi)
"""
Receive message
"""
def receiveMessage(self, myCallback):
self.log.debug('receiveMessage')
# Socket to talk to server
context = zmq.Context()
socket = context.socket(zmq.SUB)
socket.connect ("tcp://%s:%s" % (self.hostname, self.FWD_PORT))
socket.setsockopt(zmq.SUBSCRIBE, "")
while True:
json_data = socket.recv_json()
if json_data['host'] == self.hostname:
continue
#decode
encoded = base64.decodestring(json_data['msg'])
aes = AES.new(self.key, AES.MODE_CFB, self.iv)
plain = aes.decrypt(encoded)
sig = json_data['sig']
if not self.security_helper.verify_signature(sig, plain, self.rsaKey):
self.log.debug("Signature mismatch while checking own signature...")
continue
if json_data['rec'] != "255.255.255.255" and json_data['rec'] == self.hostname and json_data['msg_type'] == "ctrl":
assymEncrMessage = plain
plain = self.security_helper.decrypt_with_private_key(self.rsaKey, assymEncrMessage)
self.log.debug('Received unicast CTRL message from: %s with subtype %s' % (json_data['host'], json_data['sub_type']))
elif json_data['rec'] != "255.255.255.255" and json_data['rec'] == self.hostname and json_data['msg_type'] == "data":
if json_data['rec'] in self.globalNeighborList:
plain_encoded = base64.decodestring(plain)
if self.globalNeighborList[json_data['host']].unicastRecKey == str():
self.log.warn('Unicast Message from neighbor %s could not be decoded, no unicast key available' % (json_data['rec']))
continue
aes = AES.new(self.globalNeighborList[json_data['host']].unicastRecKey, AES.MODE_CFB, self.globalNeighborList[json_data['host']].unicastRecIv)
plain = aes.decrypt(plain_encoded)
self.log.debug('Unicast Message from neighbor %s decoded' % (json_data['rec']))
self.log.debug('rx plain |%s|' % (plain))
self.processingNeighborMessageEvent.set()
json_data['msg'] = unicode(plain, errors='ignore')
#If the message is a control message
if json_data['msg_type'] == 'ctrl':
self.log.debug("Received CTRL Message")
timestampKCM = int(time.time())
#if the message is a key change message
if json_data['sub_type'] == 'kcm':
self.log.debug("Received CTRL Message waiting for sendingUserSpaceMessageEvent")
self.sendingUserSpaceMessageEvent.wait()
self.log.debug("Received CTRL Message waiting for sendingUserCtrlMessageEvent")
self.sendingUserCtrlMessageEvent.wait()
self.log.debug("Received CTRL Message waiting for processingProbeRequestEvent")
self.processingProbeRequestEvent.wait()
self.log.debug("Received CTRL Message waiting for processingChangeKeysEvent")
self.processingChangeKeysEvent.wait()
self.log.debug("Received CTRL Message waiting for processingNeighborMessageEvent")
self.processingNeighborMessageEvent.wait()
self.log.debug("Received CTRL Message clearing processingNeighborUpdateEvent")
self.processingNeighborUpdateEvent.clear()
self.log.debug("Received CTRL Message running....")
plain_splitted = json_data['msg'].split('|')
freq = int(plain_splitted[0])
ssid = plain_splitted[1]
ipAddress = plain_splitted[2]
self.log.debug("Received key change message (KCM): ssid: %s, freq: %s " % (str(ssid), str(freq)))
if (json_data["host"] in self.globalNeighborList):
newNeighborEntry = Neighbor()
newNeighborEntry.ipAddress = ipAddress
newNeighborEntry.freq = freq
newNeighborEntry.ssid = ssid
newNeighborEntry.timestampLastKCM = timestampKCM
self.globalNeighborList = self.parsing_helper.parse_existing_neighbor(newNeighborEntry, self.globalNeighborList)
self.rescan_neighbor(freq, ssid, ipAddress, 10)
self.processingNeighborUpdateEvent.set()
#if the message is a request unicast key message
elif json_data['sub_type'] == 'ruk':
self.log.debug("Received request for unicast key (RUK) CTRL Message")
#generate unicast symmetric key and send them back.
if (json_data["host"] in self.globalNeighborList):
if len(self.globalNeighborList[json_data["host"]].unicastRecKey)>2:
retMsg = json.dumps({"key" : str(self.globalNeighborList[json_data["host"]].unicastRecKey.encode('hex')), "iv" : str(self.globalNeighborList[json_data["host"]].unicastRecIv.encode('hex'))})
self.sendCtrlToNeighbor(retMsg, "nuk", str(), str(), json_data["host"])
else:
keys = self.security_helper.generateSymmetricKeys()
retMsg = json.dumps({"key" : str(keys['keyHexStr']), "iv" : str(keys['ivHexStr'])})
self.sendCtrlToNeighbor(retMsg, "nuk", str(), str(), json_data["host"])
self.globalNeighborList[json_data["host"]].unicastRecKey = keys['key']
self.globalNeighborList[json_data["host"]].unicastRecIv = keys['iv']
else:
self.log.warn("Unkown neighbor requested symmetric unicast keys")
elif json_data['sub_type'] == 'nuk':
self.log.debug("Received new unicast key (NUK) CTRL Message")
if (json_data["host"] in self.globalNeighborList):
nukMsg = json.loads(json_data['msg'])
self.globalNeighborList[json_data["host"]].unicastSendKey = nukMsg["key"].decode('hex')
self.globalNeighborList[json_data["host"]].unicastSendIv = nukMsg["iv"].decode('hex')
self.globalNeighborList[json_data["host"]].waitingForUnicastKeys.set()
else:
myCallback(json_data)
def rescan_neighbor(self, freq, ssid, host, retries):
maxRetries = retries
found = False
for cc in range(0, maxRetries):
scanResults = self.connector.performActiveScan(False, ssid, freq, self.pubKeyHexStr, self.keyHexStr, self.ivHexStr, self.hostname, 0)
for key in scanResults:
if scanResults[key].ipAddress == host:
if str(scanResults[key].encryptionKey.encode("hex")) != str(self.globalNeighborList[host].encryptionKey.encode("hex")):
if self.debug:
self.log.debug("New key for %s successfully received" % str(host))
self.log.debug("Old Key: %s" % str(self.globalNeighborList[host].encryptionKey.encode("hex")))
self.log.debug("new Key: %s" % str(scanResults[key].encryptionKey.encode("hex")))
self.globalNeighborList[host].oldEncryptionKey = self.globalNeighborList[host].encryptionKey
self.globalNeighborList[host].oldEncryptionIV = self.globalNeighborList[host].encryptionIV
tempNeighborList = {}
tempNeighborList[scanResults[key].ipAddress] = scanResults[key]
self.onAPJoined(tempNeighborList)
found = True
else:
self.log.debug("ScanResults include old key, retry!")
if found == True:
break
else:
self.log.debug("Scan Retry triggered")
time.sleep(random.uniform(0,0.2))
if cc == (maxRetries-1):
self.log.debug("Max retries reached, neighbor removed.")
self.onAPLeft(host, "Max rescan retries reached, neighbor removed")
return False
return True
"""
Neighbor Handling
"""
def onAPJoined(self, scanResultList):
for key in scanResultList:
adjacentNode = scanResultList[key].ipAddress
# connect to peer
try:
if (adjacentNode in self.globalNeighborList):
self.globalNeighborList = self.parsing_helper.parse_existing_neighbor(scanResultList[key], self.globalNeighborList)
else:
if adjacentNode == self.hostname:
tmp_port = self.SND_PORT
else:
tmp_port = self.FWD_PORT
self.log.info("ResFi: Now connecting to: %s on port: %s" % (str(adjacentNode), str(tmp_port)))
self.frontend.connect("tcp://%s:%s" % (adjacentNode, tmp_port))
self.globalNeighborList[adjacentNode] = scanResultList[key]
for ns in self.globalAppList:
self.processingProbeRequestEvent.set()
self.log.debug("Notifying Application: %s" % str(ns))
self.globalAppList[ns].newLink_cb(adjacentNode)
except Exception as e:
self.log.error(e)
self.log.error("onAPJoined failed")
def onAPLeft(self, adjacentNode, reason):
tmp_port = self.FWD_PORT
self.log.info("ResFi: Removing neighbor %s and connection on port: %s REASON: %s" % (str(adjacentNode), str(tmp_port), str(reason)))
self.frontend.disconnect("tcp://%s:%s" % (adjacentNode, tmp_port))
del self.globalNeighborList[adjacentNode]
self.log.debug("ResFi: neighbor removed.")
for ns in self.globalAppList:
self.processingNeighborUpdateEvent.set()
self.log.debug("Notifying Application: %s" % str(ns))
self.globalAppList[ns].linkFailure_cb(adjacentNode)
"""
Key Change Thread
"""
def changeKeys(self):
#time.sleep(self.keyChangeInterval)
while True:
time.sleep(self.keyChangeInterval)
self.sendingUserSpaceMessageEvent.wait()
self.sendingUserCtrlMessageEvent.wait()
self.processingProbeRequestEvent.wait()
self.processingChangeKeysEvent.clear()
message = str(self.freq)+"|"+str(self.ssid)+"|"+str(self.hostname)
sub_type = "kcm"
key_old = self.key
iv_old = self.iv
#Generate and change Keys
self.init_symmetric_security_credentials()
self.init_self_connection()
self.connector.addIEtoProbeResponses(self.pubKeyHexStr, self.keyHexStr, self.ivHexStr, self.hostnameStrHex)
#Send KCM to all OneHopNeigbors
self.processingChangeKeysEvent.set()
self.sendCtrlToNeighbors(message, sub_type, key_old, iv_old)
self.globalNeighborList[self.hostname].timestampLastKCM = int(time.time())
self.validateCurrentNeighborList()
def validateCurrentNeighborList(self):
self.processingProbeRequestEvent.wait()
self.sendingUserSpaceMessageEvent.wait()
self.sendingUserCtrlMessageEvent.wait()
self.processingNeighborMessageEvent.wait()
self.processingNeighborUpdateEvent.clear()
timestampNow = int(time.time())
expiredNeighbors = []
self.log.debug("ResFi: Listing current neighbors stats: ")
for key in self.globalNeighborList:
if self.globalNeighborList[key].ipAddress != self.hostname:
self.log.info("ResFi: [ %s (%s/%s), Lost %s/%s]"
% (self.globalNeighborList[key].ipAddress, self.globalNeighborList[key].ssid,
str(self.globalNeighborList[key].freq), str(self.globalNeighborList[key].rxStatsLost),
str(self.globalNeighborList[key].rxStatsSuccess)))
if (timestampNow - self.globalNeighborList[key].timestampLastKCM) > (3*config.KEYCHANGEINTERVAL):
expiredNeighbors.append(self.globalNeighborList[key].ipAddress)
for i in range(0,len(expiredNeighbors)):
self.onAPLeft(expiredNeighbors[i], "neighbor did not send a KCM in the 3x KCM interval")
self.processingNeighborUpdateEvent.set()
# TODO: make me generic
def sendCtrlToNeighbors(self, message, sub_type, key, iv, nodeID= "255.255.255.255"):
self.processingProbeRequestEvent.wait()
self.processingChangeKeysEvent.wait()
self.sendingUserSpaceMessageEvent.wait()
self.sendingUserCtrlMessageEvent.clear()
max_ttl = 3
msg_type = "ctrl"
self.sendFloodingMessage(message, max_ttl, msg_type, sub_type, key, iv, nodeID)
def sendCtrlToNeighbor(self, message, sub_type, key, iv, nodeID):
self.sendCtrlToNeighbors(message, sub_type, key, iv, nodeID)
def sendFlooding(self, message, maxTTL):
self.log.debug("sendFlooding()")
self.sendFloodingMessage(message, maxTTL)
def sendFloodingMessage(self, message, max_ttl, msg_type='data', sub_type='std', key=str(), iv=str(), nodeID="255.255.255.255"):
self.log.debug("sendFloodingMessage()")
if len(key) != 16 or len(iv)!=16:
key = self.key
iv = self.iv
lasthop = self.hostname
else:
self.log.debug("sendFloodingMessage, last hop key = old keys")
lasthop = 'old_keys'
#self.key_material[lasthop] = (key, iv)
oldKeyNeighbor = Neighbor()
oldKeyNeighbor.encryptionKey = key
oldKeyNeighbor.encryptionIV = iv
oldKeyNeighbor.pubKey = self.pubKey
self.globalNeighborList[lasthop] = oldKeyNeighbor
self.log.debug("SendFlooding to: nodeID: %s, msg_type=%s" %(nodeID, msg_type))
#Apply asymmetric encryption for unicast messages
if nodeID != "255.255.255.255" and msg_type=="ctrl":
#Apply enrcyption with public key of receiver
if nodeID in self.globalNeighborList:
self.log.debug('Additional public key encryption for unicast CTRL message to %s applied.' % (nodeID))
oaep = PKCS1_OAEP.new(self.globalNeighborList[nodeID].pubKey)
asssymEncMessage = oaep.encrypt(message)
message = asssymEncMessage
else:
self.log.error('Unicast Message to neighbor %s cannot be sent, neighbor is not available in neighbor list' % (nodeID))
self.sendingUserSpaceMessageEvent.set()
return
elif nodeID != "255.255.255.255" and msg_type=="data":
if nodeID in self.globalNeighborList:
self.log.debug('Additional symmetric key encryption for unicast STD message to %s applied.' % (nodeID))
aes = AES.new(self.globalNeighborList[nodeID].unicastSendKey, AES.MODE_CFB, self.globalNeighborList[nodeID].unicastSendIv)
enc_message = aes.encrypt(message)
# to base64
enc_message_b64 = base64.encodestring(enc_message)
message = enc_message_b64
else:
self.log.error('Unicast Message to neighbor %s cannot be sent, neighbor is not available in neighbor list' % (nodeID))
self.sendingUserSpaceMessageEvent.set()
return
#create signature:
sig = self.security_helper.create_signature(message, self.rsaKey)
# encrypt message
aes = AES.new(key, AES.MODE_CFB, iv)
enc_message = aes.encrypt(message)
# to base64
enc_message_b64 = base64.encodestring(enc_message)
if msg_type != "ctrl":
self.log.debug('Source message: plain=%s, encrypted_B64=%s, rec:=%s' % (message, enc_message_b64, nodeID))
json_data = { 'host': self.hostname, 'lasthop': lasthop, 'id': self.local_id, 'rec': nodeID, 'ttl': max_ttl, 'msg_type' : msg_type, 'sub_type' : sub_type, 'msg': enc_message_b64, 'sig': sig }
self.snd_socket.send_json(json_data)
self.local_id = self.local_id + 1
def rxCbInternal(self, json_data):
json_msg = json_data['msg']
json_payload = json.loads(json_msg)
#append additional data to application json payload, e.g. sender
#json_payload['sender'] = json_msg['host']
self.log.debug("####################################################")
self.log.debug("Received message from %s Content: %s" % (str(json_data['host']), str(json_payload)))
if json_data['host'] in self.globalNeighborList:
self.log.debug("Lost Messages Overall: %s" % str(self.globalNeighborList[json_data['host']].rxStatsLost))
self.log.debug("Overall Messages Received from Neighbor: %s" % str(self.globalNeighborList[json_data['host']].rxStatsSuccess))
self.log.debug("####################################################")
if json_payload['NS'] in self.globalAppList:
self.log.debug("Notifying Application: %s" % str(json_payload['NS']))
self.globalAppList[json_payload['NS']].rx_cb(json_payload)
def sendToInternal(self, json_msg, ttl, nodeID):
message_str = json.dumps(json_msg)
self.processingProbeRequestEvent.wait()
self.processingChangeKeysEvent.wait()
self.sendingUserCtrlMessageEvent.wait()
self.sendingUserSpaceMessageEvent.clear()
self.sendFloodingMessage(message_str, ttl, 'data', 'std', str(), str(), nodeID)
"""
Implementation of Northbound API
"""
def getNeighbors(self):
currentNeighbors = []
for key in self.globalNeighborList:
if self.globalNeighborList[key].ipAddress != self.hostname and self.globalNeighborList[key].ipAddress != str():
currentNeighbors.append(self.globalNeighborList[key].ipAddress)
return currentNeighbors
def sendToNeighbors(self, json_msg, ttl):
ttl = ttl + 2 # TTL of 3 equals forwarding to next neighbor
self.sendToInternal(json_msg, ttl, "255.255.255.255")
def sendToNeighbor(self, json_msg, nodeID):
if nodeID in self.globalNeighborList:
if len(self.globalNeighborList[nodeID].unicastSendKey) > 0:
self.sendToInternal(json_msg, 3, nodeID)
return "Success"
else:
self.globalNeighborList[nodeID].waitingForUnicastKeys.clear()
max_retries = 5
retries = 0
while(self.globalNeighborList[nodeID].waitingForUnicastKeys.isSet() != True):
self.sendCtrlToNeighbor("", "ruk", str(), str(), nodeID)
time.sleep(0.5)
retries = retries + 1
if retries >= max_retries:
self.globalNeighborList[nodeID].waitingForUnicastKeys.set()
self.log.debug("Max retries reached, neighbor %s did not respond to request unicast key message (ruk)" % (nodeID))
return "Max retries reached, neighbor did not respond to request unicast key message (ruk)"
self.log.info("New unicast keys for node %s retrieved" % (nodeID))
self.sendToInternal(json_msg, 3, nodeID)
self.log.debug("Mutual unicast key exchange with node %s successful" % (nodeID))
return "Success"
else:
return "Unknown Neighbor"
def registerNewApplication(self, namespace, app):
self.globalAppList[namespace] = app
def getResFiCredentials(self, param):
if param == 1:
return self.hostname
elif param == 2:
return self.pubKey
def usePrivateRSAKey(self, data, mode):
if mode == 1:
return self.security_helper.create_signature(data, self.rsaKey)
elif mode == 2:
return self.security_helper.decrypt_with_private_key(self.rsaKey, data)
def getNodeID(self):
return self.hostname
def setChannel(self, channel):
freq = self.wifi_helper.translateChannelToFrequency(channel)
if freq !=0:
self.processingChangeKeysEvent.wait()
self.sendingUserCtrlMessageEvent.wait()
self.processingNeighborUpdateEvent.wait()
#while((int(time.time()) - self.globalNeighborList[self.hostname].timestampLastKCM) < config.CHANNEL_SWITCH_GUARD) or ((int(time.time()) - self.globalNeighborList[self.hostname].timestampLastKCM) > (config.KEYCHANGEINTERVAL-config.CHANNEL_SWITCH_GUARD)):
self.channel_switch_helper = ChannelSwitchGuardThread()
self.channel_switch_helper.run(self.globalNeighborList[self.hostname].timestampLastKCM, config.CHANNEL_SWITCH_GUARD, config.KEYCHANGEINTERVAL, freq, channel, self.connector.setChannel, self.setChannelFinished, self.channel, self.freq)
self.channel = channel
self.freq = freq
return True
else:
raise Exception("Unsupported Channel: " + str(channel))
def setChannelFinished(self, ret, channel, freq, channelOld, freqOld):
if ret == 'OK':
self.channel = channel
self.freq = freq
else:
self.log.warn("Channel Switch to %s not successful, returned error: %s" % (str(channel), str(ret)))
self.channel = channelOld
self.freq = freqOld
def getChannel(self):
return self.connector.getChannel()
def getAvailableChannels(self, restrict5Ghz=False):
return self.connector.getAvailableChannels(restrict5Ghz)
def getNetworkLoad(self):
return self.connector.getNetworkLoad()
def getTxBitrateStation(self, mac_addr):
return self.connector.getTxBitrateStation(mac_addr)
def getMacAddrAssociatedClients(self):
return self.connector.getMacAddrAssociatedClients()
def startVAP(self, ssid, neighbor_ip):
return self.connector.startVAP(ssid, neighbor_ip)
def getSSID(self):
return self.connector.getSSID()
def getMACTxBytesStation(self, mac_addr):
return self.connector.getMACTxBytesStation(mac_addr)
class ResFiAgent(ResFiNorthBoundAPI):
def __init__(self, log):
self.log = log
self.debug = config.DEBUG
self.lostMessages = 0 # TODO: do we need this?
# use the proper connector module
if config.CONNECTOR == "mininet":
self.connector = MininetConnector(log)
elif config.CONNECTOR == "linux":
self.connector = LinuxConnector(log)
# Helper Objects
self.wifi_helper = WiFiHelper(log)
self.network_helper = NetworkHelper(log)
self.security_helper = SecurityHelper(log)
self.parsing_helper = ParsingHelper(log)
# Config
self.FWD_PORT = config.FWD_PORT
self.SND_PORT = config.SND_PORT
self.SLEEP_DUR = config.SLEEP_DUR
self.keyChangeInterval = config.KEYCHANGEINTERVAL
#Internal RX Callback
self.rx_cb = self.rxCbInternal
#Init thread handling objects
self.init_thread_handling()
self.init_local_credentials()
self.init_security_credentials()
self.connector.addIEtoProbeResponses(self.pubKeyHexStr, self.keyHexStr, self.ivHexStr, self.hostnameStrHex)
self.initSendMsg()
# ResFi forwarding thread
fwd_t = threading.Thread(name='initForwarding', target=self.initForwardingTTL)
fwd_t.setDaemon(True)
fwd_t.start()
time.sleep(1)
self.init_self_connection()
scanResults = self.connector.performActiveScan(True, "", 0, self.pubKeyHexStr, self.keyHexStr, self.ivHexStr, self.hostnameStrHex, self.freq)
self.onAPJoined(scanResults)
# thread responsible for handling probe requests received by hostapd, takes callback for probe request handling
probereq_t = threading.Thread(name='subscribeToProbeRequests', target=self.connector.subscribeToProbeRequests, args=(self.handle_incoming_probe_requests,))
probereq_t.setDaemon(True)
probereq_t.start()
# receive message thread
sub_t = threading.Thread(name='receiveMessage', target=self.receiveMessage, args=(self.rx_cb,))
sub_t.setDaemon(True)
sub_t.start()
# periodic key changing
keychanger_t = threading.Thread(name='changeKeys', target=self.changeKeys)
keychanger_t.setDaemon(True)
keychanger_t.start()
"""
Init local credentials, e.g. AP params, interfaces
"""
def init_local_credentials(self):
#Initialize neighborList dict
self.globalNeighborList = {}
#Initialize appList dict
self.globalAppList = {}
self.publicInterface = self.connector.getWiredInterface()
self.hostname = self.connector.getHostname()
self.hostnameStrHex = self.hostname.encode("hex")
self.ifs = self.connector.getInterfaceList()
self.ips = self.connector.getIPList()
self.log.info("ResFi: IPS: %s" % str(self.ips))
self.log.info("ResFi: IFS: %s" % str(self.ifs))
self.log.info("ResFi: Hostname: %s" % str(self.hostname))
self.apParams = self.connector.getAPparams()
self.channel = self.apParams['channel']
self.freq = self.apParams['freq']
self.bssid = self.apParams['bssid']
self.ssid = self.apParams['ssid']
self.log.info("ResFi: BSSID: %s SSID: %s Channel: %s Frequency: %s" % (str(self.bssid), str(self.ssid), str(self.channel), str(self.freq)))
"""
Init thread_handling, e.g. event variables ...
"""
def init_thread_handling(self):
#Thread Handling
self.processingProbeRequestEvent = threading.Event()
self.processingChangeKeysEvent = threading.Event()
self.sendingUserSpaceMessageEvent = threading.Event()
self.sendingUserCtrlMessageEvent = threading.Event()
self.processingNeighborUpdateEvent = threading.Event()
self.processingNeighborMessageEvent = threading.Event()
self.processingChannelSwitchEvent = threading.Event()
self.processingProbeRequestEvent.set()
self.processingChangeKeysEvent.set()
self.sendingUserSpaceMessageEvent.set()
self.sendingUserCtrlMessageEvent.set()
self.processingNeighborUpdateEvent.set()
self.processingNeighborMessageEvent.set()
self.processingChannelSwitchEvent.set()
"""
Init security credentials, e.g. security keys, self connection, ...
"""
def init_security_credentials(self):
self.init_public_security_credentials()
self.init_symmetric_security_credentials()
def init_public_security_credentials(self):
#RSA Keys
self.rsaKey = RSA.generate(1024, os.urandom)
self.pubKey = self.rsaKey.publickey()
self.pubKeyHexStr = self.pubKey.exportKey('DER').encode("hex")
def init_symmetric_security_credentials(self):
#AES Keys
keys = self.security_helper.generateSymmetricKeys()
self.key = keys['key']
self.keyHexStr = keys['keyHexStr']
self.iv = keys['iv']
self.ivHexStr = keys['ivHexStr']
"""
Init self connection
"""
def init_self_connection(self):
#Add myself to neighbors
ownNeighborEntry = Neighbor()
ownNeighborEntry.ipAddress = self.hostname
ownNeighborEntry.encryptionKey = self.key
ownNeighborEntry.encryptionIV = self.iv
#Connect to own socket
tempNeighborList = {}
tempNeighborList[self.hostname] = ownNeighborEntry
self.onAPJoined(tempNeighborList)
"""
Forwarding while considering TTL, packet ID, ...
"""
def initForwardingTTL(self):
self.log.debug('initForwarding_ttl')
try:
context = zmq.Context(1)
# Socket facing clients
self.frontend = context.socket(zmq.SUB)
self.frontend.setsockopt(zmq.SUBSCRIBE, "")
# Socket facing services
self.backend = context.socket(zmq.PUB)
self.backend.bind("tcp://*:%s" % self.FWD_PORT)
fwd_cache = {}
while True:
json_data = self.frontend.recv_json()
# update ttl
json_data['ttl'] = int(json_data['ttl']) - 1
if json_data['ttl'] <= 0:
time.sleep(self.SLEEP_DUR)
continue
if json_data['host'] in fwd_cache and fwd_cache[json_data['host']] >= json_data['id']:
time.sleep(self.SLEEP_DUR)
continue
if json_data['host'] != self.hostname and json_data['rec'] != "255.255.255.255" and json_data['rec'] != self.hostname:
time.sleep(self.SLEEP_DUR)
continue
self.log.debug("Forwarder received message...")
self.log.debug("Forwarder waiting for ProbeRequestevent..")
self.processingProbeRequestEvent.wait()
self.log.debug("Forwarder waiting for ProcessingChangeKeysEvent..")
self.processingChangeKeysEvent.wait()
self.log.debug("Forwarder waiting for ProcessingNeighborUpdateEvent..")
self.processingNeighborUpdateEvent.wait()
self.log.debug("Forwarder is running...")
if json_data['host'] != self.hostname:
isNeighborMessage = True
self.log.debug("Forwarder is handling Message from Neighbor: %s original sender: %s" % (str(json_data['lasthop']), str(json_data['host'])))
self.processingNeighborMessageEvent.clear()
else:
isNeighborMessage = False
self.log.debug("Forwarder is handling own outgoing Message: %s original sender: %s" % (str(json_data['lasthop']), str(json_data['host'])))
if (json_data['lasthop'] in self.globalNeighborList):
lasthop_key = self.globalNeighborList[json_data['lasthop']].encryptionKey
lasthop_iv = self.globalNeighborList[json_data['lasthop']].encryptionIV
if json_data['lasthop'] != self.hostname and json_data['lasthop'] != 'old_keys':
pubKey = self.globalNeighborList[json_data['lasthop']].pubKey
else:
pubKey = self.rsaKey
lasthop_aes = AES.new(lasthop_key, AES.MODE_CFB, lasthop_iv)
enc_message_byte = base64.decodestring(json_data['msg'])
plain_msg = lasthop_aes.decrypt(enc_message_byte)
self.log.debug("From: %s" % str(json_data['lasthop']))
sig = json_data['sig']
success = False
if not self.security_helper.verify_signature(sig, plain_msg, pubKey):
self.log.debug("Signature mismatch trying with old keys if possible...")
if isNeighborMessage == False:
self.log.debug("Decrypting own message failed....")
self.sendingUserSpaceMessageEvent.set()
self.sendingUserCtrlMessageEvent.set()
continue
if self.globalNeighborList[json_data['lasthop']].oldEncryptionKey != 0 and self.globalNeighborList[json_data['lasthop']].oldEncryptionIV != 0:
lasthop_aes = AES.new(self.globalNeighborList[json_data['lasthop']].oldEncryptionKey, AES.MODE_CFB, self.globalNeighborList[json_data['lasthop']].oldEncryptionIV)
enc_message_byte = base64.decodestring(json_data['msg'])
plain_msg = lasthop_aes.decrypt(enc_message_byte)
#print "Message old key try: "+str(plain_msg)+ " From: "+str(json_data['lasthop'])
sig = json_data['sig']
if not self.security_helper.verify_signature(sig, plain_msg, pubKey):
success = False
self.log.debug("Decrypting with old keys failed")
else:
success = True
self.log.debug("Old keys worked")
else:
success = False
self.log.debug("No old keys available")
if success == False:
self.log.debug("No Old keys available or signature mismatch with old keys...")
self.log.debug("Trying to pause neighbor message processing to allow finishing of KCM process...")
self.processingNeighborMessageEvent.set()
#self.sendingUserSpaceMessageEvent.wait()
#self.sendingUserCtrlMessageEvent.wait()
self.processingNeighborUpdateEvent.wait()
self.processingProbeRequestEvent.wait()
self.processingChangeKeysEvent.wait()
self.processingNeighborMessageEvent.clear()
self.log.debug("Now trying again with hopefully new keys....")
lasthop_aes = AES.new(lasthop_key, AES.MODE_CFB, lasthop_iv)
enc_message_byte = base64.decodestring(json_data['msg'])
plain_msg = lasthop_aes.decrypt(enc_message_byte)
sig = json_data['sig']
if not self.security_helper.verify_signature(sig, plain_msg, pubKey):
self.globalNeighborList[json_data['lasthop']].lostMessages = self.globalNeighborList[json_data['lasthop']].lostMessages + 1
self.globalNeighborList[json_data['lasthop']].rxStatsLost = self.globalNeighborList[json_data['lasthop']].rxStatsLost + 1
self.log.debug("Lost Messages Counter: %s" % str(self.globalNeighborList[json_data['lasthop']].lostMessages))
self.log.debug("Lost Messages Overall: %s" % str(self.globalNeighborList[json_data['lasthop']].rxStatsLost))
self.log.debug("Overall Messages Received from Neighbor: %s" % str(self.globalNeighborList[json_data['lasthop']].rxStatsSuccess))
if self.globalNeighborList[json_data['lasthop']].lostMessages >= 5:
self.log.debug("Decrypting of neighbor messages failed %s times, trying to rescan neighbor" % (str(self.globalNeighborList[json_data['lasthop']].lostMessages)))
self.globalNeighborList[json_data['lasthop']].lostMessages = 0
if self.globalNeighborList[json_data['lasthop']].freq != 0:
self.log.debug("Trying Rescanning Neighbor, waiting for other KCM processes...")
self.processingNeighborMessageEvent.set()
self.processingNeighborUpdateEvent.wait()
self.processingProbeRequestEvent.wait()
self.processingChangeKeysEvent.wait()
self.processingNeighborUpdateEvent.clear()
freq = self.globalNeighborList[json_data['lasthop']].freq
ssid = self.globalNeighborList[json_data["lasthop"]].ssid
self.rescan_neighbor(freq, ssid, json_data['lasthop'], 10)
self.processingNeighborUpdateEvent.set()
continue
#self.processingNeighborMessageEvent.set()
else:
self.log.debug("No frequency or SSID of neighbor available")
self.onAPLeft(json_data['lasthop'], "No frequency or SSID of neighbor available")
self.processingNeighborMessageEvent.set()
continue
else:
self.processingNeighborMessageEvent.set()
continue
if json_data['lasthop'] == 'old_keys':
sendKey=lasthop_key
sendIv=lasthop_iv
else:
sendKey=self.key
sendIv=self.iv
#append own signature
sig = self.security_helper.create_signature(plain_msg, self.rsaKey)
json_data['sig'] = sig
# encrypt with my own key
aes = AES.new(sendKey, AES.MODE_CFB, sendIv)
new_message = aes.encrypt(plain_msg)
new_message_b64 = base64.encodestring(new_message)
json_data['msg'] = new_message_b64
if isNeighborMessage == True:
self.log.debug("Resetting lost messages counter of neighbor")
self.globalNeighborList[json_data['lasthop']].lostMessages = 0
self.log.debug("Incrementing overall neighbor messsage cntr")
self.globalNeighborList[json_data['lasthop']].rxStatsSuccess = self.globalNeighborList[json_data['lasthop']].rxStatsSuccess + 1
# update last hop
json_data['lasthop'] = self.hostname
self.backend.send_json(json_data)
fwd_cache[json_data['host']] = json_data['id']
if json_data['host'] == self.hostname:#
self.log.debug("Forwarder: Own Message sent from: %s" % str(json_data['lasthop']))
self.sendingUserSpaceMessageEvent.set()
self.sendingUserCtrlMessageEvent.set()
else:
self.log.debug("Forwarder: Neighbor Message forwarded from: %s" % str(json_data['lasthop']))
time.sleep(self.SLEEP_DUR)
else:
self.log.debug("fwd::cannot decode from %s; drop message" % (json_data['host']))
except Exception as e:
traceback.print_exc()
self.log.error("bringing down zmq device %s" % str(sys.exc_info()[0]))
finally:
pass
self.frontend.close()
self.backend.close()
context.term()
"""
Example message source to be disseminated
"""
def initSendMsg(self):
self.log.debug('initSendMsg')
context = zmq.Context()
self.snd_socket = context.socket(zmq.PUB)
self.snd_socket.bind("tcp://*:%s" % self.SND_PORT)
self.local_id = 1
"""
Receive Probe Requests from hostapd and handle them
"""
def handle_incoming_probe_requests(self, payload, rssi):
self.log.debug("ResFi: handle_incoming_probe_requests")
self.log.debug("ResFi: payload: %s" % payload )
if 'B16B00B5' in payload:
resfiIe = payload.split('B16B00B5',2)[1]
resfiIe = resfiIe.replace('DD06', '')
resfiFreq = payload.split('B16B00B5',2)[2]
freq = int(resfiFreq)
self.log.info("ResFi: resfiFreq: %s" % str(freq) )
self.log.debug("ResFi: Incoming ResFi Probe Request")
self.log.debug(resfiIe)
self.processingChangeKeysEvent.wait()
self.processingNeighborUpdateEvent.wait()
self.sendingUserSpaceMessageEvent.wait()
self.sendingUserCtrlMessageEvent.wait()
self.processingProbeRequestEvent.clear()
newNeighbor = self.parsing_helper.parse_resfi_ie(resfiIe, len(self.keyHexStr), len(self.ivHexStr), len(self.pubKeyHexStr), int(rssi), 0, freq, 0)
neighborList = {}
neighborList[newNeighbor.ipAddress] = newNeighbor
self.onAPJoined(neighborList)
self.processingProbeRequestEvent.set()
# # self.keyLock.release()
#print"Receive Probe Requests Thread Released # # self.keyLock.release()"
"""
Receive message
"""
def receiveMessage(self, myCallback):
self.log.debug('receiveMessage')
# Socket to talk to server
context = zmq.Context()
socket = context.socket(zmq.SUB)
socket.connect ("tcp://%s:%s" % (self.hostname, self.FWD_PORT))
socket.setsockopt(zmq.SUBSCRIBE, "")
while True:
json_data = socket.recv_json()
if json_data['host'] == self.hostname:
continue
#decode
encoded = base64.decodestring(json_data['msg'])
aes = AES.new(self.key, AES.MODE_CFB, self.iv)
plain = aes.decrypt(encoded)
sig = json_data['sig']
if not self.security_helper.verify_signature(sig, plain, self.rsaKey):
self.log.debug("Signature mismatch while checking own signature...")
continue
if json_data['rec'] != "255.255.255.255" and json_data['rec'] == self.hostname and json_data['msg_type'] == "ctrl":
assymEncrMessage = plain
plain = self.security_helper.decrypt_with_private_key(self.rsaKey, assymEncrMessage)
self.log.debug('Received unicast CTRL message from: %s with subtype %s' % (json_data['host'], json_data['sub_type']))
elif json_data['rec'] != "255.255.255.255" and json_data['rec'] == self.hostname and json_data['msg_type'] == "data":
if json_data['rec'] in self.globalNeighborList:
plain_encoded = base64.decodestring(plain)
if self.globalNeighborList[json_data['host']].unicastRecKey == str():
self.log.warn('Unicast Message from neighbor %s could not be decoded, no unicast key available' % (json_data['rec']))
continue
aes = AES.new(self.globalNeighborList[json_data['host']].unicastRecKey, AES.MODE_CFB, self.globalNeighborList[json_data['host']].unicastRecIv)
plain = aes.decrypt(plain_encoded)
self.log.debug('Unicast Message from neighbor %s decoded' % (json_data['rec']))
self.log.debug('rx plain |%s|' % (plain))
self.processingNeighborMessageEvent.set()
json_data['msg'] = unicode(plain, errors='ignore')
#If the message is a control message
if json_data['msg_type'] == 'ctrl':
self.log.debug("Received CTRL Message")
timestampKCM = int(time.time())
#if the message is a key change message
if json_data['sub_type'] == 'kcm':
self.log.debug("Received CTRL Message waiting for sendingUserSpaceMessageEvent")
self.sendingUserSpaceMessageEvent.wait()
self.log.debug("Received CTRL Message waiting for sendingUserCtrlMessageEvent")
self.sendingUserCtrlMessageEvent.wait()
self.log.debug("Received CTRL Message waiting for processingProbeRequestEvent")
self.processingProbeRequestEvent.wait()
self.log.debug("Received CTRL Message waiting for processingChangeKeysEvent")
self.processingChangeKeysEvent.wait()
self.log.debug("Received CTRL Message waiting for processingNeighborMessageEvent")
self.processingNeighborMessageEvent.wait()
self.log.debug("Received CTRL Message clearing processingNeighborUpdateEvent")
self.processingNeighborUpdateEvent.clear()
self.log.debug("Received CTRL Message running....")
plain_splitted = json_data['msg'].split('|')
freq = int(plain_splitted[0])
ssid = plain_splitted[1]
ipAddress = plain_splitted[2]
self.log.debug("Received key change message (KCM): ssid: %s, freq: %s " % (str(ssid), str(freq)))
if (json_data["host"] in self.globalNeighborList):
newNeighborEntry = Neighbor()
newNeighborEntry.ipAddress = ipAddress
newNeighborEntry.freq = freq
newNeighborEntry.ssid = ssid
newNeighborEntry.timestampLastKCM = timestampKCM
self.globalNeighborList = self.parsing_helper.parse_existing_neighbor(newNeighborEntry, self.globalNeighborList)
self.rescan_neighbor(freq, ssid, ipAddress, 10)
self.processingNeighborUpdateEvent.set()
#if the message is a request unicast key message
elif json_data['sub_type'] == 'ruk':
self.log.debug("Received request for unicast key (RUK) CTRL Message")
#generate unicast symmetric key and send them back.
if (json_data["host"] in self.globalNeighborList):
if len(self.globalNeighborList[json_data["host"]].unicastRecKey)>2:
retMsg = json.dumps({"key" : str(self.globalNeighborList[json_data["host"]].unicastRecKey.encode('hex')), "iv" : str(self.globalNeighborList[json_data["host"]].unicastRecIv.encode('hex'))})
self.sendCtrlToNeighbor(retMsg, "nuk", str(), str(), json_data["host"])
else:
keys = self.security_helper.generateSymmetricKeys()
retMsg = json.dumps({"key" : str(keys['keyHexStr']), "iv" : str(keys['ivHexStr'])})
self.sendCtrlToNeighbor(retMsg, "nuk", str(), str(), json_data["host"])
self.globalNeighborList[json_data["host"]].unicastRecKey = keys['key']
self.globalNeighborList[json_data["host"]].unicastRecIv = keys['iv']
else:
self.log.warn("Unkown neighbor requested symmetric unicast keys")
elif json_data['sub_type'] == 'nuk':
self.log.debug("Received new unicast key (NUK) CTRL Message")
if (json_data["host"] in self.globalNeighborList):
nukMsg = json.loads(json_data['msg'])
self.globalNeighborList[json_data["host"]].unicastSendKey = nukMsg["key"].decode('hex')
self.globalNeighborList[json_data["host"]].unicastSendIv = nukMsg["iv"].decode('hex')
self.globalNeighborList[json_data["host"]].waitingForUnicastKeys.set()
else:
myCallback(json_data)
def rescan_neighbor(self, freq, ssid, host, retries):
maxRetries = retries
found = False
for cc in range(0, maxRetries):
scanResults = self.connector.performActiveScan(False, ssid, freq, self.pubKeyHexStr, self.keyHexStr, self.ivHexStr, self.hostname, 0)
for key in scanResults:
if scanResults[key].ipAddress == host:
if str(scanResults[key].encryptionKey.encode("hex")) != str(self.globalNeighborList[host].encryptionKey.encode("hex")):
if self.debug:
self.log.debug("New key for %s successfully received" % str(host))
self.log.debug("Old Key: %s" % str(self.globalNeighborList[host].encryptionKey.encode("hex")))
self.log.debug("new Key: %s" % str(scanResults[key].encryptionKey.encode("hex")))
self.globalNeighborList[host].oldEncryptionKey = self.globalNeighborList[host].encryptionKey
self.globalNeighborList[host].oldEncryptionIV = self.globalNeighborList[host].encryptionIV
tempNeighborList = {}
tempNeighborList[scanResults[key].ipAddress] = scanResults[key]
self.onAPJoined(tempNeighborList)
found = True
else:
self.log.debug("ScanResults include old key, retry!")
if found == True:
break
else:
self.log.debug("Scan Retry triggered")
time.sleep(random.uniform(0,0.2))
if cc == (maxRetries-1):
self.log.debug("Max retries reached, neighbor removed.")
self.onAPLeft(host, "Max rescan retries reached, neighbor removed")
return False
return True
"""
Neighbor Handling
"""
def onAPJoined(self, scanResultList):
for key in scanResultList:
adjacentNode = scanResultList[key].ipAddress
# connect to peer
try:
if (adjacentNode in self.globalNeighborList):
self.globalNeighborList = self.parsing_helper.parse_existing_neighbor(scanResultList[key], self.globalNeighborList)
else:
if adjacentNode == self.hostname:
tmp_port = self.SND_PORT
else:
tmp_port = self.FWD_PORT
self.log.info("ResFi: Now connecting to: %s on port: %s" % (str(adjacentNode), str(tmp_port)))
self.frontend.connect("tcp://%s:%s" % (adjacentNode, tmp_port))
self.globalNeighborList[adjacentNode] = scanResultList[key]
for ns in self.globalAppList:
self.processingProbeRequestEvent.set()
self.log.debug("Notifying Application: %s" % str(ns))
self.globalAppList[ns].newLink_cb(adjacentNode)
except Exception as e:
self.log.error(e)
self.log.error("onAPJoined failed")
def onAPLeft(self, adjacentNode, reason):
tmp_port = self.FWD_PORT
self.log.info("ResFi: Removing neighbor %s and connection on port: %s REASON: %s" % (str(adjacentNode), str(tmp_port), str(reason)))
self.frontend.disconnect("tcp://%s:%s" % (adjacentNode, tmp_port))
del self.globalNeighborList[adjacentNode]
self.log.debug("ResFi: neighbor removed.")
for ns in self.globalAppList:
self.processingNeighborUpdateEvent.set()
self.log.debug("Notifying Application: %s" % str(ns))
self.globalAppList[ns].linkFailure_cb(adjacentNode)
"""
Key Change Thread
"""
def changeKeys(self):
#time.sleep(self.keyChangeInterval)
while True:
time.sleep(self.keyChangeInterval)
self.sendingUserSpaceMessageEvent.wait()
self.sendingUserCtrlMessageEvent.wait()
self.processingProbeRequestEvent.wait()
self.processingChangeKeysEvent.clear()
message = str(self.freq)+"|"+str(self.ssid)+"|"+str(self.hostname)
sub_type = "kcm"
key_old = self.key
iv_old = self.iv
#Generate and change Keys
self.init_symmetric_security_credentials()
self.init_self_connection()
self.connector.addIEtoProbeResponses(self.pubKeyHexStr, self.keyHexStr, self.ivHexStr, self.hostnameStrHex)
#Send KCM to all OneHopNeigbors
self.processingChangeKeysEvent.set()
self.sendCtrlToNeighbors(message, sub_type, key_old, iv_old)
self.globalNeighborList[self.hostname].timestampLastKCM = int(time.time())
self.validateCurrentNeighborList()
def validateCurrentNeighborList(self):
self.processingProbeRequestEvent.wait()
self.sendingUserSpaceMessageEvent.wait()
self.sendingUserCtrlMessageEvent.wait()
self.processingNeighborMessageEvent.wait()
self.processingNeighborUpdateEvent.clear()
timestampNow = int(time.time())
expiredNeighbors = []
self.log.debug("ResFi: Listing current neighbors stats: ")
for key in self.globalNeighborList:
if self.globalNeighborList[key].ipAddress != self.hostname:
self.log.info("ResFi: [ %s (%s/%s), Lost %s/%s]"
% (self.globalNeighborList[key].ipAddress, self.globalNeighborList[key].ssid,
str(self.globalNeighborList[key].freq), str(self.globalNeighborList[key].rxStatsLost),
str(self.globalNeighborList[key].rxStatsSuccess)))
if (timestampNow - self.globalNeighborList[key].timestampLastKCM) > (3*config.KEYCHANGEINTERVAL):
expiredNeighbors.append(self.globalNeighborList[key].ipAddress)
for i in range(0,len(expiredNeighbors)):
self.onAPLeft(expiredNeighbors[i], "neighbor did not send a KCM in the 3x KCM interval")
self.processingNeighborUpdateEvent.set()
# TODO: make me generic
def sendCtrlToNeighbors(self, message, sub_type, key, iv, nodeID= "255.255.255.255"):
self.processingProbeRequestEvent.wait()
self.processingChangeKeysEvent.wait()
self.sendingUserSpaceMessageEvent.wait()
self.sendingUserCtrlMessageEvent.clear()
max_ttl = 3
msg_type = "ctrl"
self.sendFloodingMessage(message, max_ttl, msg_type, sub_type, key, iv, nodeID)
def sendCtrlToNeighbor(self, message, sub_type, key, iv, nodeID):
self.sendCtrlToNeighbors(message, sub_type, key, iv, nodeID)
def sendFlooding(self, message, maxTTL):
self.log.debug("sendFlooding()")
self.sendFloodingMessage(message, maxTTL)
def sendFloodingMessage(self, message, max_ttl, msg_type='data', sub_type='std', key=str(), iv=str(), nodeID="255.255.255.255"):
self.log.debug("sendFloodingMessage()")
if len(key) != 16 or len(iv)!=16:
key = self.key
iv = self.iv
lasthop = self.hostname
else:
self.log.debug("sendFloodingMessage, last hop key = old keys")
lasthop = 'old_keys'
#self.key_material[lasthop] = (key, iv)
oldKeyNeighbor = Neighbor()
oldKeyNeighbor.encryptionKey = key
oldKeyNeighbor.encryptionIV = iv
oldKeyNeighbor.pubKey = self.pubKey
self.globalNeighborList[lasthop] = oldKeyNeighbor
self.log.debug("SendFlooding to: nodeID: %s, msg_type=%s" %(nodeID, msg_type))
#Apply asymmetric encryption for unicast messages
if nodeID != "255.255.255.255" and msg_type=="ctrl":
#Apply enrcyption with public key of receiver
if nodeID in self.globalNeighborList:
self.log.debug('Additional public key encryption for unicast CTRL message to %s applied.' % (nodeID))
oaep = PKCS1_OAEP.new(self.globalNeighborList[nodeID].pubKey)
asssymEncMessage = oaep.encrypt(message)
message = asssymEncMessage
else:
self.log.error('Unicast Message to neighbor %s cannot be sent, neighbor is not available in neighbor list' % (nodeID))
self.sendingUserSpaceMessageEvent.set()
return
elif nodeID != "255.255.255.255" and msg_type=="data":
if nodeID in self.globalNeighborList:
self.log.debug('Additional symmetric key encryption for unicast STD message to %s applied.' % (nodeID))
aes = AES.new(self.globalNeighborList[nodeID].unicastSendKey, AES.MODE_CFB, self.globalNeighborList[nodeID].unicastSendIv)
enc_message = aes.encrypt(message)
# to base64
enc_message_b64 = base64.encodestring(enc_message)
message = enc_message_b64
else:
self.log.error('Unicast Message to neighbor %s cannot be sent, neighbor is not available in neighbor list' % (nodeID))
self.sendingUserSpaceMessageEvent.set()
return
#create signature:
sig = self.security_helper.create_signature(message, self.rsaKey)
# encrypt message
aes = AES.new(key, AES.MODE_CFB, iv)
enc_message = aes.encrypt(message)
# to base64
enc_message_b64 = base64.encodestring(enc_message)
if msg_type != "ctrl":
self.log.debug('Source message: plain=%s, encrypted_B64=%s, rec:=%s' % (message, enc_message_b64, nodeID))
json_data = { 'host': self.hostname, 'lasthop': lasthop, 'id': self.local_id, 'rec': nodeID, 'ttl': max_ttl, 'msg_type' : msg_type, 'sub_type' : sub_type, 'msg': enc_message_b64, 'sig': sig }
self.snd_socket.send_json(json_data)
self.local_id = self.local_id + 1
def rxCbInternal(self, json_data):
json_msg = json_data['msg']
json_payload = json.loads(json_msg)
#append additional data to application json payload, e.g. sender
#json_payload['sender'] = json_msg['host']
self.log.debug("####################################################")
self.log.debug("Received message from %s Content: %s" % (str(json_data['host']), str(json_payload)))
if json_data['host'] in self.globalNeighborList:
self.log.debug("Lost Messages Overall: %s" % str(self.globalNeighborList[json_data['host']].rxStatsLost))
self.log.debug("Overall Messages Received from Neighbor: %s" % str(self.globalNeighborList[json_data['host']].rxStatsSuccess))
self.log.debug("####################################################")
if json_payload['NS'] in self.globalAppList:
self.log.debug("Notifying Application: %s" % str(json_payload['NS']))
self.globalAppList[json_payload['NS']].rx_cb(json_payload)
def sendToInternal(self, json_msg, ttl, nodeID):
message_str = json.dumps(json_msg)
self.processingProbeRequestEvent.wait()
self.processingChangeKeysEvent.wait()
self.sendingUserCtrlMessageEvent.wait()
self.sendingUserSpaceMessageEvent.clear()
self.sendFloodingMessage(message_str, ttl, 'data', 'std', str(), str(), nodeID)
"""
Implementation of Northbound API
"""
def getNeighbors(self):
currentNeighbors = []
for key in self.globalNeighborList:
if self.globalNeighborList[key].ipAddress != self.hostname and self.globalNeighborList[key].ipAddress != str():
currentNeighbors.append(self.globalNeighborList[key].ipAddress)
return currentNeighbors
def sendToNeighbors(self, json_msg, ttl):
ttl = ttl + 2 # TTL of 3 equals forwarding to next neighbor
self.sendToInternal(json_msg, ttl, "255.255.255.255")
def sendToNeighbor(self, json_msg, nodeID):
if nodeID in self.globalNeighborList:
if len(self.globalNeighborList[nodeID].unicastSendKey) > 0:
self.sendToInternal(json_msg, 3, nodeID)
return "Success"
else:
self.globalNeighborList[nodeID].waitingForUnicastKeys.clear()
max_retries = 5
retries = 0
while(self.globalNeighborList[nodeID].waitingForUnicastKeys.isSet() != True):
self.sendCtrlToNeighbor("", "ruk", str(), str(), nodeID)
time.sleep(0.5)
retries = retries + 1
if retries >= max_retries:
self.globalNeighborList[nodeID].waitingForUnicastKeys.set()
self.log.debug("Max retries reached, neighbor %s did not respond to request unicast key message (ruk)" % (nodeID))
return "Max retries reached, neighbor did not respond to request unicast key message (ruk)"
self.log.info("New unicast keys for node %s retrieved" % (nodeID))
self.sendToInternal(json_msg, 3, nodeID)
self.log.debug("Mutual unicast key exchange with node %s successful" % (nodeID))
return "Success"
else:
return "Unknown Neighbor"
def registerNewApplication(self, namespace, app):
self.globalAppList[namespace] = app
def getResFiCredentials(self, param):
if param == 1:
return self.hostname
elif param == 2:
return self.pubKey
def usePrivateRSAKey(self, data, mode):
if mode == 1:
return self.security_helper.create_signature(data, self.rsaKey)
elif mode == 2:
return self.security_helper.decrypt_with_private_key(self.rsaKey, data)
def getNodeID(self):
return self.hostname
def setChannel(self, channel):
freq = self.wifi_helper.translateChannelToFrequency(channel)
if freq !=0:
self.processingChangeKeysEvent.wait()
self.sendingUserCtrlMessageEvent.wait()
self.processingNeighborUpdateEvent.wait()
#while((int(time.time()) - self.globalNeighborList[self.hostname].timestampLastKCM) < config.CHANNEL_SWITCH_GUARD) or ((int(time.time()) - self.globalNeighborList[self.hostname].timestampLastKCM) > (config.KEYCHANGEINTERVAL-config.CHANNEL_SWITCH_GUARD)):
self.channel_switch_helper = ChannelSwitchGuardThread()
self.channel_switch_helper.run(self.globalNeighborList[self.hostname].timestampLastKCM, config.CHANNEL_SWITCH_GUARD, config.KEYCHANGEINTERVAL, freq, channel, self.connector.setChannel, self.setChannelFinished, self.channel, self.freq)
self.channel = channel
self.freq = freq
return True
else:
raise Exception("Unsupported Channel: " + str(channel))
def setChannelFinished(self, ret, channel, freq, channelOld, freqOld):
if ret == 'OK':
self.channel = channel
self.freq = freq
else:
self.log.warn("Channel Switch to %s not successful, returned error: %s" % (str(channel), str(ret)))
self.channel = channelOld
self.freq = freqOld
def getChannel(self):
return self.connector.getChannel()
def getAvailableChannels(self, restrict5Ghz=False):
return self.connector.getAvailableChannels(restrict5Ghz)
def getNetworkLoad(self):
return self.connector.getNetworkLoad()
