Implemented links

This commit is contained in:
Mark Qvist 2018-04-16 17:13:39 +02:00
parent 52968e8ba5
commit 75e0cb039d
9 changed files with 296 additions and 36 deletions

1
.gitignore vendored
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@ -1,4 +1,5 @@
.DS_Store
*.pyc
t.py
t2.py
TODO

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@ -1,8 +1,8 @@
header types
-----------------
type 1 00 One byte header, one 10 byte address field
type 2 01 One byte header, two 10 byte address fields
type 3 10 Reserved
type 1 00 Two byte header, one 10 byte address field
type 2 01 Two byte header, two 10 byte address fields
type 3 10 Two byte header, one 10 byte address field, used for link request proofs
type 4 11 Reserved for extended header format

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@ -9,6 +9,11 @@ from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.primitives.asymmetric import padding
class Callbacks:
def __init__(self):
self.link_established = None
self.packet = None
self.proof = None
class Destination:
KEYSIZE = RNS.Identity.KEYSIZE;
@ -59,11 +64,14 @@ class Destination:
if "." in app_name: raise ValueError("Dots can't be used in app names")
if not type in Destination.types: raise ValueError("Unknown destination type")
if not direction in Destination.directions: raise ValueError("Unknown destination direction")
self.callbacks = Callbacks()
self.type = type
self.direction = direction
self.proof_strategy = Destination.PROVE_NONE
self.mtu = 0
self.links = []
if identity != None and type == Destination.SINGLE:
aspects = aspects+(identity.hexhash,)
@ -87,11 +95,14 @@ class Destination:
return "<"+self.name+"/"+self.hexhash+">"
def setCallback(self, callback):
self.callback = callback
def link_established_callback(self, callback):
self.callbacks.link_established = callback
def setProofCallback(self, callback):
self.proofcallback = callback
def packet_callback(self, callback):
self.callbacks.packet = callback
def proof_callback(self, callback):
self.callbacks.proof = callback
def setProofStrategy(self, proof_strategy):
if not proof_strategy in Destination.proof_strategies:
@ -101,9 +112,19 @@ class Destination:
def receive(self, packet):
plaintext = self.decrypt(packet.data)
if plaintext != None and self.callback != None:
self.callback(plaintext, packet)
if plaintext != None:
if packet.packet_type == RNS.Packet.LINKREQUEST:
self.incomingLinkRequest(plaintext, packet)
if packet.packet_type == RNS.Packet.RESOURCE:
if self.callbacks.packet != None:
self.callbacks.packet(plaintext, packet)
def incomingLinkRequest(self, data, packet):
link = RNS.Link.validateRequest(self, data, packet)
if link != None:
RNS.log(str(self)+" accepted link request", RNS.LOG_DEBUG)
self.links.append(link)
def createKeys(self):
if self.type == Destination.PLAIN:

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@ -14,9 +14,9 @@ from cryptography.hazmat.primitives.asymmetric import rsa
from cryptography.hazmat.primitives.asymmetric import padding
class Identity:
# Configure key size
KEYSIZE = 1536
DERKEYSIZE = 1808
#KEYSIZE = 1536
KEYSIZE = 1024
DERKEYSIZE = KEYSIZE+272
# Padding size, not configurable
PADDINGSIZE= 336
@ -223,7 +223,7 @@ class Identity:
)
)
except:
RNS.log("Decryption by "+RNS.prettyhexrep(self.hash)+" failed")
RNS.log("Decryption by "+RNS.prettyhexrep(self.hash)+" failed", RNS.LOG_VERBOSE)
return plaintext;
else:

174
RNS/Link.py Normal file
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@ -0,0 +1,174 @@
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric import ec
from cryptography.hazmat.primitives.kdf.hkdf import HKDF
from cryptography.fernet import Fernet
import base64
import RNS
import traceback
class LinkCallbacks:
def __init__(self):
self.link_established = None
self.packet = None
self.resource_started = None
self.resource_completed = None
class Link:
CURVE = ec.SECP256R1()
ECPUBSIZE = 91
PENDING = 0x00
ACTIVE = 0x01
@staticmethod
def validateRequest(owner, data, packet):
if len(data) == (Link.ECPUBSIZE):
try:
link = Link(owner = owner, peer_pub_bytes = data[:Link.ECPUBSIZE])
link.setLinkID(packet)
RNS.log("Validating link request "+RNS.prettyhexrep(link.link_id), RNS.LOG_VERBOSE)
link.handshake()
link.attached_interface = packet.receiving_interface
link.prove()
RNS.Transport.registerLink(link)
if link.owner.callbacks.link_established != None:
link.owner.callbacks.link_established(link)
RNS.log("Incoming link request "+str(link)+" accepted", RNS.LOG_VERBOSE)
except Exception as e:
RNS.log("Validating link request failed", RNS.LOG_VERBOSE)
return None
else:
RNS.log("Invalid link request payload size, dropping request", RNS.LOG_VERBOSE)
return None
def __init__(self, destination=None, owner=None, peer_pub_bytes = None):
self.callbacks = LinkCallbacks()
self.status = Link.PENDING
self.type = RNS.Destination.LINK
self.owner = owner
self.destination = destination
self.attached_interface = None
if self.destination == None:
self.initiator = False
else:
self.initiator = True
self.prv = ec.generate_private_key(Link.CURVE, default_backend())
self.pub = self.prv.public_key()
self.pub_bytes = self.pub.public_bytes(
encoding=serialization.Encoding.DER,
format=serialization.PublicFormat.SubjectPublicKeyInfo
)
if peer_pub_bytes == None:
self.peer_pub = None
self.peer_pub_bytes = None
else:
self.loadPeer(peer_pub_bytes)
if (self.initiator):
self.request_data = self.pub_bytes
self.packet = RNS.Packet(destination, self.request_data, packet_type=RNS.Packet.LINKREQUEST)
self.packet.pack()
self.setLinkID(self.packet)
RNS.Transport.registerLink(self)
self.packet.send()
RNS.log("Link request "+RNS.prettyhexrep(self.link_id)+" sent to "+str(self.destination), RNS.LOG_VERBOSE)
def loadPeer(self, peer_pub_bytes):
self.peer_pub_bytes = peer_pub_bytes
self.peer_pub = serialization.load_der_public_key(peer_pub_bytes, backend=default_backend())
self.peer_pub.curce = Link.CURVE
def setLinkID(self, packet):
self.link_id = RNS.Identity.truncatedHash(packet.raw)
self.hash = self.link_id
def handshake(self):
self.shared_key = self.prv.exchange(ec.ECDH(), self.peer_pub)
self.derived_key = HKDF(
algorithm=hashes.SHA256(),
length=32,
salt=self.getSalt(),
info=self.getContext(),
backend=default_backend()
).derive(self.shared_key)
def prove(self):
signed_data = self.link_id+self.pub_bytes
signature = self.owner.identity.sign(signed_data)
proof_data = self.pub_bytes+signature
proof = RNS.Packet(self, proof_data, packet_type=RNS.Packet.PROOF, header_type=RNS.Packet.HEADER_3)
proof.send()
def validateProof(self, packet):
peer_pub_bytes = packet.data[:Link.ECPUBSIZE]
signed_data = self.link_id+peer_pub_bytes
signature = packet.data[Link.ECPUBSIZE:RNS.Identity.KEYSIZE/8+Link.ECPUBSIZE]
if self.destination.identity.validate(signature, signed_data):
self.loadPeer(peer_pub_bytes)
self.handshake()
self.attached_interface = packet.receiving_interface
RNS.Transport.activateLink(self)
if self.callbacks.link_established != None:
self.callbacks.link_established(self)
RNS.log("Link "+str(self)+" established with "+str(self.destination), RNS.LOG_VERBOSE)
else:
RNS.log("Invalid link proof signature received by "+str(self), RNS.LOG_VERBOSE)
def getSalt(self):
return self.link_id
def getContext(self):
return None
def receive(self, packet):
if packet.receiving_interface != self.attached_interface:
RNS.log("Link-associated packet received on unexpected interface! Someone might be trying to manipulate your communication!", RNS.LOG_ERROR)
else:
plaintext = self.decrypt(packet.data)
if (self.callbacks.packet != None):
self.callbacks.packet(plaintext, packet)
def encrypt(self, plaintext):
try:
fernet = Fernet(base64.urlsafe_b64encode(self.derived_key))
ciphertext = base64.urlsafe_b64decode(fernet.encrypt(plaintext))
return ciphertext
except Exception as e:
RNS.log("Encryption on link "+str(self)+" failed. The contained exception was: "+str(e), RNS.LOG_ERROR)
def decrypt(self, ciphertext):
try:
fernet = Fernet(base64.urlsafe_b64encode(self.derived_key))
plaintext = fernet.decrypt(base64.urlsafe_b64encode(ciphertext))
return plaintext
except Exception as e:
RNS.log("Decryption failed on link "+str(self)+". The contained exception was: "+str(e), RNS.LOG_ERROR)
def link_established_callback(self, callback):
self.callbacks.link_established = callback
def packet_callback(self, callback):
self.callbacks.packet = callback
def resource_started_callback(self, callback):
self.callbacks.resource_started = callback
def resource_completed_callback(self, callback):
self.callbacks.resource_completed = callback
def __str__(self):
return RNS.prettyhexrep(self.link_id)

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@ -12,7 +12,7 @@ class Packet:
HEADER_1 = 0x00; # Normal header format
HEADER_2 = 0x01; # Header format used for link packets in transport
HEADER_3 = 0x02; # Reserved
HEADER_3 = 0x02; # Normal header format, but used to indicate a link request proof
HEADER_4 = 0x03; # Reserved
header_types = [HEADER_1, HEADER_2, HEADER_3, HEADER_4]
@ -30,7 +30,7 @@ class Packet:
self.transport_id = transport_id
self.data = data
self.flags = self.getPackedFlags()
self.MTU = self.destination.MTU
self.MTU = RNS.Reticulum.MTU
self.raw = None
self.packed = False
@ -45,6 +45,9 @@ class Packet:
self.packet_hash = None
def getPackedFlags(self):
if self.header_type == Packet.HEADER_3:
packed_flags = (self.header_type << 6) | (self.transport_type << 4) | RNS.Destination.LINK | self.packet_type
else:
packed_flags = (self.header_type << 6) | (self.transport_type << 4) | (self.destination.type << 2) | self.packet_type
return packed_flags
@ -58,11 +61,15 @@ class Packet:
else:
raise IOError("Packet with header type 2 must have a transport ID")
if self.header_type == Packet.HEADER_1:
self.header += self.destination.hash
if self.packet_type != Packet.ANNOUNCE:
self.ciphertext = self.destination.encrypt(self.data)
else:
self.ciphertext = self.data
if self.header_type == Packet.HEADER_3:
self.header += self.destination.link_id
self.ciphertext = self.data
self.raw = self.header + self.ciphertext
@ -93,9 +100,10 @@ class Packet:
def send(self):
if not self.sent:
if not self.packed:
self.pack()
#RNS.log("Size: "+str(len(self.raw))+" header is "+str(len(self.header))+" payload is "+str(len(self.ciphertext)), RNS.LOG_DEBUG)
RNS.Transport.outbound(self.raw)
RNS.Transport.outbound(self)
self.packet_hash = RNS.Identity.fullHash(self.raw)
self.sent_at = time.time()
self.sent = True

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@ -8,7 +8,7 @@ import os.path
import os
import RNS
import traceback
#import traceback
class Reticulum:
MTU = 500

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@ -10,15 +10,23 @@ class Transport:
interfaces = []
destinations = []
pending_links = []
active_links = []
packet_hashlist = []
@staticmethod
def outbound(raw):
Transport.cacheRaw(raw)
def outbound(packet):
Transport.cacheRaw(packet.raw)
for interface in Transport.interfaces:
if interface.OUT:
RNS.log("Transmitting "+str(len(raw))+" bytes via: "+str(interface), RNS.LOG_DEBUG)
interface.processOutgoing(raw)
should_transmit = True
if packet.destination.type == RNS.Destination.LINK:
if interface != packet.destination.attached_interface:
should_transmit = False
if should_transmit:
RNS.log("Transmitting "+str(len(packet.raw))+" bytes via: "+str(interface), RNS.LOG_DEBUG)
interface.processOutgoing(packet.raw)
@staticmethod
def inbound(raw, interface=None):
@ -30,12 +38,26 @@ class Transport:
packet = RNS.Packet(None, raw)
packet.unpack()
packet.packet_hash = packet_hash
packet.receiving_interface = interface
if packet.packet_type == RNS.Packet.ANNOUNCE:
if RNS.Identity.validateAnnounce(packet):
Transport.cache(packet)
if packet.packet_type == RNS.Packet.LINKREQUEST:
for destination in Transport.destinations:
if destination.hash == packet.destination_hash and destination.type == packet.destination_type:
packet.destination = destination
destination.receive(packet)
Transport.cache(packet)
if packet.packet_type == RNS.Packet.RESOURCE:
if packet.destination_type == RNS.Destination.LINK:
for link in Transport.active_links:
if link.link_id == packet.destination_hash:
link.receive(packet)
Transport.cache(packet)
else:
for destination in Transport.destinations:
if destination.hash == packet.destination_hash and destination.type == packet.destination_type:
packet.destination = destination
@ -43,6 +65,13 @@ class Transport:
Transport.cache(packet)
if packet.packet_type == RNS.Packet.PROOF:
if packet.header_type == RNS.Packet.HEADER_3:
# This is a link request proof, forward
# to a waiting link request
for link in Transport.pending_links:
if link.link_id == packet.destination_hash:
link.validateProof(packet)
else:
for destination in Transport.destinations:
if destination.hash == packet.destination_hash:
if destination.proofcallback != None:
@ -55,8 +84,34 @@ class Transport:
if destination.direction == RNS.Destination.IN:
Transport.destinations.append(destination)
@staticmethod
def registerLink(link):
RNS.log("Registering link "+str(link))
if link.initiator:
Transport.pending_links.append(link)
else:
Transport.active_links.append(link)
@staticmethod
def activateLink(link):
RNS.log("Activating link "+str(link))
if link in Transport.pending_links:
Transport.pending_links.remove(link)
Transport.active_links.append(link)
link.status = RNS.Link.ACTIVE
else:
RNS.log("Attempted to activate a link that was not in the pending table", RNS.LOG_ERROR)
@staticmethod
def shouldCache(packet):
# TODO: Implement sensible rules for which
# packets to cache
return False
@staticmethod
def cache(packet):
if RNS.Transport.shouldCache(packet):
RNS.Transport.cacheRaw(packet.raw)
@staticmethod

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@ -4,6 +4,7 @@ import time
from .Reticulum import Reticulum
from .Identity import Identity
from .Link import Link
from .Transport import Transport
from .Destination import Destination
from .Packet import Packet