Handshake working with new abstractions

hexnoise.py

@@ -2,6 +2,7 @@
 
 import time
 import string
+import enum
 
 from cobs import cobs
 
@@ -28,9 +29,22 @@ def hexdump(write, packet, width=16):
     _print_line(write, ts-startup, packet, width=width)
     write()
 
-def send_packet(ser, data, width=16):
-    print(f'\033[93mSending {len(data)} bytes\033[0m')
+class PacketType(enum.Enum):
+    _RESERVED = 0
+    INITIATE_HANDSHAKE = 1
+    HANDSHAKE = 2
+    DATA = 3
+
+class ReportType(enum.Enum):
+    _RESERVED = 0
+    KEYBOARD = 1
+    MOUSE = 2
+    PAIRING = 3 # keyboard in disguise
+
+def send_packet(ser, pkt_type, data, width=16):
+    print(f'\033[93mSending {len(data)} bytes, packet type {pkt_type.name} ({pkt_type.value})\033[0m')
     hexdump(print, data, width)
+    data = bytes([pkt_type.value]) + data
     encoded = cobs.encode(data) + b'\0'
     ser.write(encoded)
     ser.flushOutput()
@@ -40,7 +54,7 @@ def receive_packet(ser, width=16):
     data = cobs.decode(packet[:-1])
     print(f'\033[93mReceived {len(data)} bytes\033[0m')
     hexdump(print, data, width)
-    return data
+    return data[0], data[1:]
 
 if __name__ == '__main__':
     import argparse
@@ -85,16 +99,21 @@ if __name__ == '__main__':
     proto.set_as_initiator()
     proto.set_keypair_from_private_bytes(Keypair.STATIC, STATIC_LOCAL)
     proto.start_handshake()
+    send_packet(ser, PacketType.INITIATE_HANDSHAKE, b'', args.width)
     print('Handshake started')
 
     while True:
         if proto.handshake_finished:
             break
-        send_packet(ser, proto.write_message(), args.width)
+        send_packet(ser, PacketType.HANDSHAKE, proto.write_message(), args.width)
 
         if proto.handshake_finished:
                 break
-        proto.read_message(receive_packet(ser, args.width))
+        pkt_type, payload = receive_packet(ser, args.width)
+        if pkt_type == PacketType.HANDSHAKE.value:
+            proto.read_message(payload)
+        else:
+            print(f'Incorrect packet type {pkt_type}. Ignoring since this is only test code.')
     print('Handshake finished, handshake hash:')
     hexdump(print, proto.get_handshake_hash(), args.width)
 
@@ -126,7 +145,11 @@ if __name__ == '__main__':
     with uinput.Device(ALL_KEYS) as ui:
         while True:
             try:
-                received = receive_packet(ser, args.width)
+                pkt_type, received = receive_packet(ser, args.width)
+                if pkt_type != PacketType.DATA.value:
+                    print(f'Unexpected packet type {pkt_type}. Ignoring.')
+                    continue
+
                 try:
                     noise_rx(received, ui)
                 except NoiseInvalidMessage as e:
@@ -145,3 +168,4 @@ if __name__ == '__main__':
                         proto.noise_protocol.cipher_state_decrypt.n = orig_n
             except Exception as e:
                 print('Invalid framing:', e)
+