udpated hmac code signing - stil not working I guess

tnc/data_handler.py

@@ -919,16 +919,17 @@ class DATA:
 
             # check if hmac signing enabled
             if TNC.enable_hmac:
-                hmac_digest = hmac.new(TNC.hmac_salt, data_frame, hashlib.sha256).digest()[:4]
                 # now check if we have valid hmac signature
-                if hmac_digest == data_frame_crc_received:
+                salt_found = helpers.search_hmac_salt(self.dxcallsign, self.mycallsign, data_frame_crc, token_iters=100)
+                if salt_found:
                     # hmac digest received
                     self.arq_process_received_data_frame(data_frame, snr, signed=True)
 
                 else:
                     # hmac signature wrong
                     self.arq_process_received_data_frame(data_frame, snr, signed=False)
-
+            elif data_frame_crc == data_frame_crc_received:
+                self.arq_process_received_data_frame(data_frame, snr, signed=False)
             else:
                 self.send_data_to_socket_queue(
                     freedata="tnc-message",
@@ -1289,7 +1290,7 @@ class DATA:
                 tempbuffer = []
                 self.rpt_request_buffer = []
                 # Append data frames with n_frames_per_burst to tempbuffer
-                for n_frame in range(0, n_frames_per_burst):
+                for n_frame in range(n_frames_per_burst):
                     arqheader = bytearray()
                     arqheader[:1] = bytes([FR_TYPE.BURST_01.value + n_frame])
                     #####arqheader[:1] = bytes([FR_TYPE.BURST_01.value])
@@ -1663,7 +1664,7 @@ class DATA:
         print(self.rpt_request_buffer)
 
         tempbuffer_rptframes = []
-        for i in range(0, len(missing_area)):
+        for i in range(len(missing_area)):
             print(missing_area[i])
             missing_frames_buffer_position = missing_area[i] - 1
             tempbuffer_rptframes.append(self.rpt_request_buffer[missing_frames_buffer_position])
@@ -2134,7 +2135,7 @@ class DATA:
             return True
 
         return False
-arq_transmit
+
     def arq_open_data_channel(
             self, mycallsign
     ) -> bool:

tnc/helpers.py

@@ -13,6 +13,8 @@ import structlog
 import numpy as np
 import threading
 import mesh
+import hashlib
+import hmac
 
 log = structlog.get_logger("helpers")
 
@@ -494,7 +496,7 @@ def bool_to_string(state):
 
 
 def get_hmac_salt(dxcallsign: bytes, mycallsign: bytes):
-    filename = f"freedata_hmac_tokens_{int(time.time())}_{dxcallsign}_{mycallsign}.txt"
+    filename = f"freedata_hmac_tokens_{dxcallsign}_{mycallsign}.txt"
     try:
         with open(filename, "w") as file:
             line = file.readlines()
@@ -503,6 +505,25 @@ def get_hmac_salt(dxcallsign: bytes, mycallsign: bytes):
     except Exception:
         return False
 
+def search_hmac_salt(dxcallsign: bytes, mycallsign: bytes, search_token, data_frame, token_iters):
+    try:
+        filename = f"freedata_hmac_tokens_{dxcallsign}_{mycallsign}.txt"
+        with open(filename, "w") as file:
+            token_list = file.readlines()
+
+            token_iters = min(token_iters, len(token_list))
+            for _ in range(1, token_iters + 1):
+                key = token_list[len(token_list) - _][:-1]
+                search_digest = hmac.new(key, data_frame, hashlib.sha256).digest()[:4]
+                if search_token == search_digest:
+                    return True
+
+        return False
+
+    except Exception:
+        return False
+
+
 def delete_last_line_from_hmac_list(filename):
     try:
         linearray = []

tools/create_hmac_tokes.py

@@ -17,9 +17,9 @@ def create_hmac_salts(dxcallsign: str, mycallsign: str, num_tokens: int = 10000)
     """
     try:
         # Create and write random strings to a file
-        with open(f"freedata_hmac_tokens_{int(time.time())}_{dxcallsign}_{mycallsign}.txt", "w") as file:
+        with open(f"freedata_hmac_tokens_{dxcallsign}_{mycallsign}.txt", "w") as file:
             for _ in range(num_tokens):
-                random_str = np.random.bytes(16).hex()
+                random_str = np.random.bytes(4).hex()
                 file.write(random_str + '\n')
     except Exception:
         print("error creating hmac file")