def processMessages( self, circuit, data ):
"""
Acts on extracted protocol messages based on header flags.
After the incoming `data' is decrypted and authenticated, this method
processes the received data based on the header flags. Payload is
written to the local application using `circuit', new tickets are
stored or keys are added to the replay table.
"""
assert circuit
if (data is None) or (len(data) == 0):
return
# Try to extract protocol messages from the encrypted blurb.
msgs = self.extractMessages(data, self.recvCrypter)
if (msgs is None) or (len(msgs) == 0):
return
for msg in msgs:
# Forward data to the application.
if msg.flags & const.FLAG_PAYLOAD:
circuit.upstream.write(msg.payload)
# Store newly received ticket and send ACK to the server.
elif self.weAreClient and msg.flags == const.FLAG_NEW_TICKET:
assert len(msg) == (const.HDR_LENGTH + const.TICKET_LENGTH +
const.MASTER_KEY_LENGTH)
peer = circuit.downstream.transport.getPeer()
ticket.storeNewTicket(msg.payload[0:const.MASTER_KEY_LENGTH],
msg.payload[const.MASTER_KEY_LENGTH:
const.MASTER_KEY_LENGTH +
const.TICKET_LENGTH], peer)
# Use the PRNG seed to generate the same probability distributions
# as the server. That's where the polymorphism comes from.
elif self.weAreClient and msg.flags == const.FLAG_PRNG_SEED:
assert len(msg.payload) == const.PRNG_SEED_LENGTH
log.debug("Obtained PRNG seed.")
prng = random.Random(msg.payload)
pktDist = probdist.new(lambda: prng.randint(const.HDR_LENGTH,
const.MTU),
seed=msg.payload)
self.pktMorpher = packetmorpher.new(pktDist)
self.iatMorpher = probdist.new(lambda: prng.random() %
const.MAX_PACKET_DELAY,
seed=msg.payload)
else:
log.warning("Invalid message flags: %d." % msg.flags)
def processMessages(self, data):
"""
Acts on extracted protocol messages based on header flags.
After the incoming `data' is decrypted and authenticated, this method
processes the received data based on the header flags. Payload is
written to the local application, new tickets are stored, or keys are
added to the replay table.
"""
if (data is None) or (len(data) == 0):
return
# Try to extract protocol messages from the encrypted blurb.
msgs = self.protoMsg.extract(data, self.recvCrypter, self.recvHMAC)
if (msgs is None) or (len(msgs) == 0):
return
for msg in msgs:
# Forward data to the application.
if msg.flags == const.FLAG_PAYLOAD:
self.circuit.upstream.write(msg.payload)
# Store newly received ticket.
elif self.weAreClient and (msg.flags == const.FLAG_NEW_TICKET):
assert len(msg.payload) == (const.TICKET_LENGTH +
const.MASTER_KEY_LENGTH)
peer = self.circuit.downstream.transport.getPeer()
ticket.storeNewTicket(
msg.payload[0:const.MASTER_KEY_LENGTH], msg.
payload[const.MASTER_KEY_LENGTH:const.MASTER_KEY_LENGTH +
const.TICKET_LENGTH], peer)
# Use the PRNG seed to generate the same probability distributions
# as the server. That's where the polymorphism comes from.
elif self.weAreClient and (msg.flags == const.FLAG_PRNG_SEED):
assert len(msg.payload) == const.PRNG_SEED_LENGTH
#log.debug("Obtained PRNG seed.")
prng = random.Random(msg.payload)
pktDist = probdist.new(
lambda: prng.randint(const.HDR_LENGTH, const.MTU),
seed=msg.payload)
self.pktMorpher = packetmorpher.new(pktDist)
self.iatMorpher = probdist.new(
lambda: prng.random() % const.MAX_PACKET_DELAY,
seed=msg.payload)
else:
#log.warning("Invalid message flags: %d." % msg.flags)
pass