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Commit 01b5ba60d06d3dbaea9366445ec6ab6022c5d6d5
Parents : 0c32bbc
Author : Mark Qvist <mark@unsigned.io>
Date : 2021-05-04T10:19:07+02:00
Added signature validation on incoming messages
Changes
Diff
diff --git a/LXMF/LXMF.py b/LXMF/LXMF.py
index 09d5196..8f92ef6 100644
--- a/LXMF/LXMF.py
+++ b/LXMF/LXMF.py
@@ -7,22 +7,26 @@ import RNS.vendor.umsgpack as msgpack
APP_NAME = "lxmf"
class LXMessage:
- DRAFT = 0x00
- OUTBOUND = 0x01
- SENDING = 0x02
- SENT = 0x04
- DELIVERED = 0x08
- states = [DRAFT, OUTBOUND, SENDING, SENT, DELIVERED]
-
- UNKNOWN = 0x00
- PACKET = 0x01
- RESOURCE = 0x02
- representations = [UNKNOWN, PACKET, RESOURCE]
-
- OPPORTUNISTIC = 0x01
- DIRECT = 0x02
- PROPAGATED = 0x03
- valid_methods = [OPPORTUNISTIC, DIRECT, PROPAGATED]
+ DRAFT = 0x00
+ OUTBOUND = 0x01
+ SENDING = 0x02
+ SENT = 0x04
+ DELIVERED = 0x08
+ states = [DRAFT, OUTBOUND, SENDING, SENT, DELIVERED]
+
+ UNKNOWN = 0x00
+ PACKET = 0x01
+ RESOURCE = 0x02
+ representations = [UNKNOWN, PACKET, RESOURCE]
+
+ OPPORTUNISTIC = 0x01
+ DIRECT = 0x02
+ PROPAGATED = 0x03
+ valid_methods = [OPPORTUNISTIC, DIRECT, PROPAGATED]
+
+ SOURCE_UNKNOWN = 0x01
+ SIGNATURE_INVALID = 0x02
+ unverified_reasons = [SOURCE_UNKNOWN, SIGNATURE_INVALID]
DESTINATION_LENGTH = RNS.Identity.TRUNCATED_HASHLENGTH//8
SIGNATURE_LENGTH = RNS.Identity.SIGLENGTH//8
@@ -100,6 +104,10 @@ class LXMessage:
self.state = LXMessage.DRAFT
self.method = LXMessage.UNKNOWN
+ self.incoming = False
+ self.signature_validated = False
+ self.unverified_reason = None
+
self.representation = LXMessage.UNKNOWN
self.desired_method = desired_method
self.delivery_attempts = 0
@@ -163,57 +171,62 @@ class LXMessage:
self.__delivery_destination = delivery_destination
def pack(self):
- self.timestamp = time.time()
- self.payload = [self.timestamp, self.title, self.content, self.fields]
-
- hashed_part = b""
- hashed_part += self.__destination.hash
- hashed_part += self.__source.hash
- hashed_part += msgpack.packb(self.payload)
- self.hash = RNS.Identity.fullHash(hashed_part)
- self.message_id = self.hash
-
- signed_part = b""
- signed_part += hashed_part
- signed_part += self.hash
- self.signature = self.__source.sign(signed_part)
-
- self.packed = b""
- self.packed += self.__destination.hash
- self.packed += self.__source.hash
- self.packed += self.signature
- packed_payload = msgpack.packb(self.payload)
- self.packed += packed_payload
- self.packed_size = len(self.packed)
- content_size = len(packed_payload)
-
- # If no desired delivery method has been defined,
- # one will be chosen according to these rules:
- if self.desired_method == None:
- self.desired_method == LXMessage.DIRECT
- # TODO: Expand rules to something more intelligent
-
- if self.desired_method == LXMessage.OPPORTUNISTIC:
- if self.__destination.type == RNS.Destination.SINGLE:
- single_packet_content_limit = LXMessage.RSA_PACKET_MAX_CONTENT
- elif self.__destination.type == RNS.Destination.PLAIN:
- single_packet_content_limit = LXMessage.PLAIN_PACKET_MAX_CONTENT
-
- if content_size > single_packet_content_limit:
- raise TypeError("LXMessage desired opportunistic delivery method, but content exceeds single-packet size.")
- else:
- self.method = LXMessage.OPPORTUNISTIC
- self.representation = LXMessage.PACKET
- self.__delivery_destination = self.__destination
-
- elif self.desired_method == LXMessage.DIRECT or self.desired_method == LXMessage.PROPAGATED:
- single_packet_content_limit = LXMessage.LINK_PACKET_MAX_CONTENT
- if content_size <= single_packet_content_limit:
- self.method = self.desired_method
- self.representation = LXMessage.PACKET
- else:
- self.method = self.desired_method
- self.representation = LXMessage.RESOURCE
+ if not self.packed:
+ self.timestamp = time.time()
+ self.payload = [self.timestamp, self.title, self.content, self.fields]
+
+ hashed_part = b""
+ hashed_part += self.__destination.hash
+ hashed_part += self.__source.hash
+ hashed_part += msgpack.packb(self.payload)
+ self.hash = RNS.Identity.fullHash(hashed_part)
+ self.message_id = self.hash
+
+ signed_part = b""
+ signed_part += hashed_part
+ signed_part += self.hash
+ self.signature = self.__source.sign(signed_part)
+ self.signature_validated = True
+
+ self.packed = b""
+ self.packed += self.__destination.hash
+ self.packed += self.__source.hash
+ self.packed += self.signature
+ packed_payload = msgpack.packb(self.payload)
+ self.packed += packed_payload
+ self.packed_size = len(self.packed)
+ content_size = len(packed_payload)
+
+ # If no desired delivery method has been defined,
+ # one will be chosen according to these rules:
+ if self.desired_method == None:
+ self.desired_method == LXMessage.DIRECT
+ # TODO: Expand rules to something more intelligent
+
+ if self.desired_method == LXMessage.OPPORTUNISTIC:
+ if self.__destination.type == RNS.Destination.SINGLE:
+ single_packet_content_limit = LXMessage.RSA_PACKET_MAX_CONTENT
+ elif self.__destination.type == RNS.Destination.PLAIN:
+ single_packet_content_limit = LXMessage.PLAIN_PACKET_MAX_CONTENT
+
+ if content_size > single_packet_content_limit:
+ raise TypeError("LXMessage desired opportunistic delivery method, but content exceeds single-packet size.")
+ else:
+ self.method = LXMessage.OPPORTUNISTIC
+ self.representation = LXMessage.PACKET
+ self.__delivery_destination = self.__destination
+
+ elif self.desired_method == LXMessage.DIRECT or self.desired_method == LXMessage.PROPAGATED:
+ single_packet_content_limit = LXMessage.LINK_PACKET_MAX_CONTENT
+ if content_size <= single_packet_content_limit:
+ self.method = self.desired_method
+ self.representation = LXMessage.PACKET
+ else:
+ self.method = self.desired_method
+ self.representation = LXMessage.RESOURCE
+ else:
+ raise ValueError("Attempt to re-pack LXMessage "+str(self)+" that was already packed")
+
def send(self):
if self.method == LXMessage.OPPORTUNISTIC:
@@ -274,9 +287,13 @@ class LXMessage:
source_hash = lxmf_bytes[LXMessage.DESTINATION_LENGTH:2*LXMessage.DESTINATION_LENGTH]
signature = lxmf_bytes[2*LXMessage.DESTINATION_LENGTH:2*LXMessage.DESTINATION_LENGTH+LXMessage.SIGNATURE_LENGTH]
packed_payload = lxmf_bytes[2*LXMessage.DESTINATION_LENGTH+LXMessage.SIGNATURE_LENGTH:]
+ hashed_part = b"" + destination_hash + source_hash + packed_payload
+ message_hash = RNS.Identity.fullHash(hashed_part)
+ signed_part = b"" + hashed_part + message_hash
unpacked_payload = msgpack.unpackb(packed_payload)
destination = RNS.Identity.recall(destination_hash)
- source = RNS.Identity.recall(source_hash)
+ source_identity = RNS.Identity.recall(source_hash)
+ source = RNS.Destination(source_identity, RNS.Destination.OUT, RNS.Destination.SINGLE, APP_NAME, "delivery")
timestamp = unpacked_payload[0]
title_bytes = unpacked_payload[1]
content_bytes = unpacked_payload[2]
@@ -291,15 +308,31 @@ class LXMessage:
destination_hash = destination_hash,
source_hash = source_hash)
+ message.hash = message_hash
+ message.signature = signature
+ message.incoming = True
+ message.timestamp = timestamp
+ message.packed = lxmf_bytes
message.set_title_from_bytes(title_bytes)
message.set_content_from_bytes(content_bytes)
- message.timestamp = timestamp
+
+ try:
+ if source:
+ if source.identity.validate(signature, signed_part):
+ message.signature_validated = True
+ else:
+ message.signature_validated = False
+ message.unverified_reason = LXMessage.SIGNATURE_INVALID
+ else:
+ signature_validated = False
+ message.unverified_reason = LXMessage.SOURCE_UNKNOWN
+ RNS.log("LXMF message signature could not be validated, since source identity is unknown")
+ except Exception as e:
+ message.signature_validated = False
+ RNS.log("Error while validating LXMF message signature. The contained exception was: "+str(e), RNS.LOG_ERROR)
return message
- @staticmethod
- def unpack_from_file(lxmf_file_handle):
- pass
class LXMRouter:
MAX_DELIVERY_ATTEMPTS = 3
@@ -352,26 +385,30 @@ class LXMRouter:
def lxmf_delivery(self, lxmf_data, destination_type = None):
try:
message = LXMessage.unpack_from_bytes(lxmf_data)
- except Exception as e:
- RNS.log("Could not assemble LXMF message from received data", RNS.LOG_NOTICE)
- RNS.log("The contained exception was: "+str(e), RNS.LOG_DEBUG)
- if RNS.Reticulum.should_allow_unencrypted():
- message.transport_encryption = "Consider unencrypted (Disabling encryption was allowed in Reticulum configuration)"
- else:
- if destination_type == RNS.Destination.SINGLE:
- message.transport_encryption = "RSA-"+str(RNS.Identity.KEYSIZE)
- elif destination_type == RNS.Destination.GROUP:
- message.transport_encryption = "AES-128"
- elif destination_type == RNS.Destination.LINK:
- message.transport_encryption = "EC-SECP256R1"
+ if RNS.Reticulum.should_allow_unencrypted():
+ message.transport_encryption = "Consider unencrypted (Disabling encryption was allowed in Reticulum configuration)"
else:
- message.transport_encryption = None
+ if destination_type == RNS.Destination.SINGLE:
+ message.transport_encryption = "RSA-"+str(RNS.Identity.KEYSIZE)
+ elif destination_type == RNS.Destination.GROUP:
+ message.transport_encryption = "AES-128"
+ elif destination_type == RNS.Destination.LINK:
+ message.transport_encryption = "EC-SECP256R1"
+ else:
+ message.transport_encryption = None
- if self.__delivery_callback != None:
- self.__delivery_callback(message)
+ if self.__delivery_callback != None:
+ self.__delivery_callback(message)
+
+ return True
+
+ except Exception as e:
+ RNS.log("Could not assemble LXMF message from received data", RNS.LOG_NOTICE)
+ RNS.log("The contained exception was: "+str(e), RNS.LOG_DEBUG)
+ raise e
+ return False
- return True
def delivery_packet(self, data, packet):
try:
@@ -404,7 +441,7 @@ class LXMRouter:
def resource_transfer_concluded(self, resource):
RNS.log("Transfer concluded for resource "+str(resource), RNS.LOG_DEBUG)
if resource.status == RNS.Resource.COMPLETE:
- self.lxmf_delivery(resource.data, resource.link.type)
+ self.lxmf_delivery(resource.data.read(), resource.link.type)
def jobloop(self):
while (True):
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