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Updated LXMF to Reticulum 0.2.1 elliptic curve cryptography

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This commit is contained in:
Mark Qvist 2021-05-20 22:17:55 +02:00
commit 75c7e80269
3 changed files with 25 additions and 26 deletions
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47
LXMF/LXMF.py
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@ -32,37 +32,37 @@ class LXMessage:
DESTINATION_LENGTH = RNS.Identity.TRUNCATED_HASHLENGTH//8
SIGNATURE_LENGTH = RNS.Identity.SIGLENGTH//8
# LXMF overhead is 163 bytes per message:
# LXMF overhead is 99 bytes per message:
# 10 bytes for destination hash
# 10 bytes for source hash
# 128 bytes for RSA signature
# 64 bytes for Ed25519 signature
# 8 bytes for timestamp
# 7 bytes for msgpack structure
LXMF_OVERHEAD = 2*DESTINATION_LENGTH + SIGNATURE_LENGTH + 8 + 7
# With an MTU of 500, the maximum RSA-encrypted
# amount of data we can send in a single packet
# is given by the below calculation; 258 bytes.
RSA_PACKET_MDU = RNS.Packet.RSA_MDU
# With an MTU of 500, the maximum amount of data
# we can send in a single encrypted packet is
# 383 bytes.
ENCRYPTED_PACKET_MDU = RNS.Packet.ENCRYPTED_MDU
# The max content length we can fit in LXMF message
# inside a single RNS packet is the RSA MDU, minus
# inside a single RNS packet is the encrypted MDU, minus
# the LXMF overhead. We can optimise a bit though, by
# inferring the destination hash from the destination
# field of the packet, therefore we also add the length
# of a destination hash to the calculation. With default
# RNS and LXMF parameters, the largest single-packet
# LXMF message we can send is 105 bytes. If a message
# LXMF message we can send is 294 bytes. If a message
# is larger than that, a Reticulum link will be used.
RSA_PACKET_MAX_CONTENT = RSA_PACKET_MDU - LXMF_OVERHEAD + DESTINATION_LENGTH
ENCRYPTED_PACKET_MAX_CONTENT = ENCRYPTED_PACKET_MDU - LXMF_OVERHEAD + DESTINATION_LENGTH
# Links can carry a significantly larger MDU, due to
# more efficient elliptic curve cryptography. The link
# MDU with default Reticulum parameters is 415 bytes.
# Links can carry a larger MDU, due to less overhead per
# packet. The link MDU with default Reticulum parameters
# is 415 bytes.
LINK_PACKET_MDU = RNS.Link.MDU
# Which means that we can deliver single-packet LXMF
# messages with content of up to 252 bytes over a link.
# messages with content of up to 316 bytes over a link.
# If a message is larger than that, LXMF will sequence
# and transfer it as a RNS resource over the link instead.
LINK_PACKET_MAX_CONTENT = LINK_PACKET_MDU - LXMF_OVERHEAD
@ -73,9 +73,8 @@ class LXMessage:
PLAIN_PACKET_MAX_CONTENT = PLAIN_PACKET_MDU - LXMF_OVERHEAD + DESTINATION_LENGTH
# Descriptive strings regarding transport encryption
ENCRYPTION_DESCRIPTION_RSA = "RSA-"+str(RNS.Identity.KEYSIZE)
ENCRYPTION_DESCRIPTION_AES = "AES-128"
ENCRYPTION_DESCRIPTION_EC = "Curve25519+Fernet"
ENCRYPTION_DESCRIPTION_EC = "Curve25519"
ENCRYPTION_DESCRIPTION_UNENCRYPTED = "Unencrypted"
def __str__(self):
@ -255,7 +254,7 @@ class LXMessage:
self.determine_transport_encryption()
if self.method == LXMessage.OPPORTUNISTIC:
self.__as_packet().send().delivery_callback(self.__mark_delivered)
self.__as_packet().send().set_delivery_callback(self.__mark_delivered)
self.state = LXMessage.SENT
elif self.method == LXMessage.DIRECT:
self.state = LXMessage.SENDING
@ -272,7 +271,7 @@ class LXMessage:
if self.method == LXMessage.OPPORTUNISTIC:
if self.destination.type == RNS.Destination.SINGLE:
self.transport_encrypted = True
self.transport_encryption = LXMessage.ENCRYPTION_DESCRIPTION_RSA
self.transport_encryption = LXMessage.ENCRYPTION_DESCRIPTION_EC
elif destination_type == RNS.Destination.GROUP:
self.transport_encrypted = True
self.transport_encryption = LXMessage.ENCRYPTION_DESCRIPTION_AES
@ -285,7 +284,7 @@ class LXMessage:
elif self.method == LXMessage.PROPAGATED:
if self.destination.type == RNS.Destination.SINGLE:
self.transport_encrypted = True
self.transport_encryption = LXMessage.ENCRYPTION_DESCRIPTION_RSA
self.transport_encryption = LXMessage.ENCRYPTION_DESCRIPTION_EC
elif destination_type == RNS.Destination.GROUP:
self.transport_encrypted = True
self.transport_encryption = LXMessage.ENCRYPTION_DESCRIPTION_AES
@ -479,8 +478,8 @@ class LXMRouter:
def register_delivery_identity(self, identity, display_name = None):
delivery_destination = RNS.Destination(identity, RNS.Destination.IN, RNS.Destination.SINGLE, "lxmf", "delivery")
delivery_destination.packet_callback(self.delivery_packet)
delivery_destination.link_established_callback(self.delivery_link_established)
delivery_destination.set_packet_callback(self.delivery_packet)
delivery_destination.set_link_established_callback(self.delivery_link_established)
delivery_destination.display_name = display_name
if display_name != None:
@ -559,10 +558,10 @@ class LXMRouter:
RNS.log("The contained exception was: "+str(e), RNS.LOG_ERROR)
def delivery_link_established(self, link):
link.packet_callback(self.delivery_packet)
link.set_packet_callback(self.delivery_packet)
link.set_resource_strategy(RNS.Link.ACCEPT_ALL)
link.resource_started_callback(self.resource_transfer_began)
link.resource_concluded_callback(self.resource_transfer_concluded)
link.set_resource_started_callback(self.resource_transfer_began)
link.set_resource_concluded_callback(self.resource_transfer_concluded)
def delivery_link_closed(self, link):
pass
@ -669,7 +668,7 @@ class LXMRouter:
if RNS.Transport.has_path(lxmessage.get_destination().hash):
RNS.log("Establishing link to "+RNS.prettyhexrep(lxmessage.get_destination().hash)+" for delivery attempt "+str(lxmessage.delivery_attempts)+" to "+RNS.prettyhexrep(lxmessage.get_destination().hash), RNS.LOG_DEBUG)
delivery_link = RNS.Link(lxmessage.get_destination())
delivery_link.link_established_callback(self.process_outbound)
delivery_link.set_link_established_callback(self.process_outbound)
self.direct_links[delivery_destination_hash] = delivery_link
else:
RNS.log("No path known for delivery attempt "+str(lxmessage.delivery_attempts)+" to "+RNS.prettyhexrep(lxmessage.get_destination().hash)+". Requesting path...", RNS.LOG_DEBUG)