Added allow list (default off)

* Added an option for an allow list (`/storage/allowed`), if the file is present the users source address is checked against the list, if its not present they will be messaged to say they aren't authorised. 

Please note this feature is not default and only activates in the allowed file is present.

messageboard.py

@@ -33,6 +33,17 @@ def lxmf_delivery(message):
     time_string = time.strftime("%Y-%m-%d %H:%M:%S", time.localtime(message.timestamp))
     new_message = '{} {}: {}\n'.format(time_string, username, message_content)
 
+    # If an allowed file is present then check to see if a user is authorised
+    if os.path.isfile(allowedpath):
+        f = open(allowedpath, "rb")
+        allowed_list = msgpack.unpack(f)
+        f.close()
+        if source_hash_text not in allowed_list:
+            # Send reply
+            message_reply = '{}_{}_You aren\'t authorised to post to this message board '.format(source_hash_text, time.time())
+            q.put(message_reply)
+            return
+
     # Push message to board
     # First read message board (if it exists
     if os.path.isfile(boardpath):
@@ -139,6 +150,7 @@ if not os.path.isdir(storagepath):
 identitypath = configdir+"/storage/identity"
 announcepath = configdir+"/storage/announce"
 boardpath = configdir+"/storage/board"
+allowedpath = configdir+"/storage/allowed"
 
 # Message Queue
 q = Queue(maxsize = 5)