def circuitConnected(self):
"""
Do the obfs2 handshake:
SEED | E_PAD_KEY( UINT32(MAGIC_VALUE) | UINT32(PADLEN) | WR(PADLEN) )
"""
# Generate keys for outgoing padding.
self.send_padding_crypto = \
self._derive_padding_crypto(self.initiator_seed if self.we_are_initiator else self.responder_seed,
self.send_pad_keytype)
padding_length = random.randint(0, MAX_PADDING)
seed = self.initiator_seed if self.we_are_initiator else self.responder_seed
handshake_message = seed + self.send_padding_crypto.crypt(srlz.htonl(MAGIC_VALUE) +
srlz.htonl(padding_length) +
rand.random_bytes(padding_length))
log.debug("obfs2 handshake: %s queued %d bytes (padding_length: %d).",
"initiator" if self.we_are_initiator else "responder",
len(handshake_message), padding_length)
self.circuit.downstream.write(handshake_message)
def circuitConnected(self):
"""
Do the obfs2 handshake:
SEED | E_PAD_KEY( UINT32(MAGIC_VALUE) | UINT32(PADLEN) | WR(PADLEN) )
"""
# Generate keys for outgoing padding.
self.send_padding_crypto = \
self._derive_padding_crypto(self.initiator_seed if self.we_are_initiator else self.responder_seed,
self.send_pad_keytype)
padding_length = random.randint(0, MAX_PADDING)
seed = self.initiator_seed if self.we_are_initiator else self.responder_seed
handshake_message = seed + self.send_padding_crypto.crypt(srlz.htonl(MAGIC_VALUE) +
srlz.htonl(padding_length) +
rand.random_bytes(padding_length))
log.debug("obfs2 handshake: %s queued %d bytes (padding_length: %d).",
"initiator" if self.we_are_initiator else "responder",
len(handshake_message), padding_length)
self.circuit.downstream.write(handshake_message)