From e1f0d54ac803ee7fc0f81147c32f83e6f11d7467 Mon Sep 17 00:00:00 2001
From: Yohann D'ANELLO <ynerant@crans.org>
Date: Mon, 21 Dec 2020 16:04:16 +0100
Subject: [PATCH] Use a random squirrel id and an incremental nonce

Signed-off-by: Yohann D'ANELLO <ynerant@crans.org>
---
 squinnondation/hazel.py    | 11 +++++++++--
 squinnondation/messages.py | 10 +++++++---
 2 files changed, 16 insertions(+), 5 deletions(-)

diff --git a/squinnondation/hazel.py b/squinnondation/hazel.py
index b01428d..28bdb16 100644
--- a/squinnondation/hazel.py
+++ b/squinnondation/hazel.py
@@ -1,6 +1,7 @@
 # Copyright (C) 2020 by eichhornchen, ÿnérant
 # SPDX-License-Identifier: GPL-3.0-or-later
 from datetime import datetime
+from random import randint
 from typing import Any, Tuple
 from ipaddress import IPv6Address
 from threading import Thread
@@ -17,6 +18,7 @@ class Hazelnut:
     """
     def __init__(self, nickname: str = None, address: str = "localhost", port: int = 2500):
         self.nickname = nickname
+        self.id = -1
 
         try:
             # Resolve DNS as an IPv6
@@ -37,6 +39,11 @@ class Squirrel(Hazelnut):
     """
     def __init__(self, instance: Any, nickname: str):
         super().__init__(nickname, instance.bind_address, instance.bind_port)
+
+        # Random identifier on 64 bits
+        self.id = randint(0, 1 << 64 - 1)
+        self.incr_nonce = 0
+
         # Create UDP socket
         self.socket = socket.socket(socket.AF_INET6, socket.SOCK_DGRAM)
         # Bind the socket
@@ -175,7 +182,7 @@ class Squirrel(Hazelnut):
         elif key != "\n":
             # Insert the pressed key in the current message
             new_buffer = self.input_buffer[:self.input_index] + key + self.input_buffer[self.input_index:]
-            if len(DataTLV.construct(f"{self.nickname}: {new_buffer}")) > 255 - 8 - 4:
+            if len(DataTLV.construct(f"{self.nickname}: {new_buffer}", None)) > 255 - 8 - 4:
                 # The message is too long to be sent once. We don't allow the user to type any other character.
                 curses.beep()
                 return
@@ -194,7 +201,7 @@ class Squirrel(Hazelnut):
         msg = f"{self.nickname}: {msg}"
         self.add_message(msg)
 
-        pkt = Packet.construct(DataTLV.construct(msg))
+        pkt = Packet.construct(DataTLV.construct(msg, self))
         for hazelnut in list(self.hazelnuts.values()):
             self.send_packet(hazelnut, pkt)
 
diff --git a/squinnondation/messages.py b/squinnondation/messages.py
index 7080e74..f36577e 100644
--- a/squinnondation/messages.py
+++ b/squinnondation/messages.py
@@ -227,13 +227,17 @@ class DataTLV(TLV):
                 sender.nickname = nickname
 
     @staticmethod
-    def construct(message: str) -> "DataTLV":
+    def construct(message: str, squirrel: Any) -> "DataTLV":
         tlv = DataTLV()
         tlv.type = 4
-        tlv.sender_id = 42  # FIXME Use the good sender id
-        tlv.nonce = 42  # FIXME Use an incremental nonce
+        tlv.sender_id = squirrel.id if squirrel else 0
+        tlv.nonce = squirrel.incr_nonce if squirrel else 0
         tlv.data = message.encode("UTF-8")
         tlv.length = 12 + len(tlv.data)
+
+        if squirrel:
+            squirrel.incr_nonce += 1
+
         return tlv