114 lines
3.4 KiB
Python
114 lines
3.4 KiB
Python
|
import nacl
|
||
|
|
|
||
|
|
from msg import RelayNetMsg
|
||
|
|
|
||
|
|
class RelayCell(RelayNetMsg):
|
||
|
|
"""All cells (which are sent inside a CircuitCellMsg, and so do not
|
||
|
|
need their own circuitid) should be a subclass of this class."""
|
||
|
|
|
||
|
|
|
||
|
|
class StringCell(RelayCell):
|
||
|
|
"""Send an arbitrary string as a cell."""
|
||
|
|
def __init__(self, str):
|
||
|
|
self.data = str
|
||
|
|
|
||
|
|
def __str__(self):
|
||
|
|
return self.data.__str__()
|
||
|
|
|
||
|
|
|
||
|
|
class CloseCell(RelayCell):
|
||
|
|
"""Close the circuit this cell was sent on. It should be sent
|
||
|
|
_unencrypted_ (not within an EncryptedCell), and relays that receive
|
||
|
|
one should forward it along the adjacent circuit, then close both
|
||
|
|
the circuit it was received on and the adjacent one."""
|
||
|
|
|
||
|
|
|
||
|
|
class VanillaCreatedCircuitCell(RelayCell):
|
||
|
|
"""The message for responding to circuit creation in Vanilla Onion
|
||
|
|
Routing."""
|
||
|
|
|
||
|
|
def __init__(self, ntor_reply):
|
||
|
|
self.ntor_reply = ntor_reply
|
||
|
|
|
||
|
|
|
||
|
|
class VanillaExtendCircuitCell(RelayCell):
|
||
|
|
"""The message for requesting circuit extension in Vanilla Onion
|
||
|
|
Routing."""
|
||
|
|
|
||
|
|
def __init__(self, hopaddr, ntor_request):
|
||
|
|
self.hopaddr = hopaddr
|
||
|
|
self.ntor_request = ntor_request
|
||
|
|
|
||
|
|
|
||
|
|
class VanillaExtendedCircuitCell(RelayCell):
|
||
|
|
"""The message for responding to circuit extension in Vanilla Onion
|
||
|
|
Routing."""
|
||
|
|
|
||
|
|
def __init__(self, ntor_reply):
|
||
|
|
self.ntor_reply = ntor_reply
|
||
|
|
|
||
|
|
|
||
|
|
class TelescopingCreatedCircuitCell(RelayCell):
|
||
|
|
"""The message for responding to circuit creation in Telescoping Walking
|
||
|
|
Onions."""
|
||
|
|
|
||
|
|
def __init__(self, ntor_reply):
|
||
|
|
self.ntor_reply = ntor_reply
|
||
|
|
|
||
|
|
|
||
|
|
class TelescopingExtendCircuitCell(RelayCell):
|
||
|
|
"""The message for requesting circuit extension in Telescoping Walking
|
||
|
|
Onions."""
|
||
|
|
|
||
|
|
def __init__(self, idx, ntor_request):
|
||
|
|
self.idx = idx
|
||
|
|
self.ntor_request = ntor_request
|
||
|
|
|
||
|
|
|
||
|
|
class TelescopingExtendedCircuitCell(RelayCell):
|
||
|
|
"""The message for responding to circuit extension in Telescoping Walking
|
||
|
|
Onions."""
|
||
|
|
|
||
|
|
def __init__(self, ntor_reply, snip):
|
||
|
|
self.ntor_reply = ntor_reply
|
||
|
|
self.snip = snip
|
||
|
|
|
||
|
|
class SinglePassCreatedCircuitCell(RelayCell):
|
||
|
|
"""The message for responding to circuit creation in Single-Pass Walking
|
||
|
|
Onions."""
|
||
|
|
|
||
|
|
def __init__(self, ntor_reply, encrypted_cell):
|
||
|
|
self.ntor_reply = ntor_reply
|
||
|
|
# The above field is sent in plaintext; the below is an
|
||
|
|
# SinglePassCreatedEnc, or None if this is the last layer
|
||
|
|
self.enc = encrypted_cell
|
||
|
|
|
||
|
|
|
||
|
|
class EncryptedCell(RelayCell):
|
||
|
|
"""Send a message encrypted with a symmetric key. In this
|
||
|
|
implementation, the encryption is not really done. A hash of the
|
||
|
|
key is stored with the message so that it can be checked at
|
||
|
|
decryption time."""
|
||
|
|
|
||
|
|
def __init__(self, key, msg):
|
||
|
|
self.keyhash = nacl.hash.sha256(key)
|
||
|
|
self.plaintext = msg
|
||
|
|
|
||
|
|
def decrypt(self, key):
|
||
|
|
keyhash = nacl.hash.sha256(key)
|
||
|
|
if keyhash != self.keyhash:
|
||
|
|
raise ValueError("EncryptedCell key mismatch")
|
||
|
|
return self.plaintext
|
||
|
|
|
||
|
|
def size(self):
|
||
|
|
# Current Tor actually has no overhead for encryption
|
||
|
|
return self.plaintext.size()
|
||
|
|
|
||
|
|
|
||
|
|
class SinglePassCreatedEnc(EncryptedCell):
|
||
|
|
"""The nested encrypted informaion inside a
|
||
|
|
SinglePassCreatedCircuitCell. nextlayer is itself a
|
||
|
|
SinglePassCreatedCircuitCell."""
|
||
|
|
def __init__(self, key, snip, vrf_output, nextlayer):
|
||
|
|
super().__init__(key, (snip, vrf_output, nextlayer))
|