strip = sign at the end of b64 strings

helper_func.py

@@ -34,14 +34,16 @@ async def is_subscribed(filter, client, update):
 
 async def encode(string):
     string_bytes = string.encode("ascii")
-    base64_bytes = base64.b64encode(string_bytes)
-    return base64_bytes.decode("ascii")
-
+    base64_bytes = base64.urlsafe_b64encode(string_bytes)
+    base64_string = (base64_bytes.decode("ascii")).strip("=")
+    return base64_string
 
 async def decode(base64_string):
-    base64_bytes = base64_string.encode("ascii")
-    string_bytes = base64.b64decode(base64_bytes)
-    return string_bytes.decode("ascii")
+    base64_string = base64_string.strip("=") # links generated before this commit will be having = sign, hence striping them to handle padding errors.
+    base64_bytes = (base64_string + "=" * (-len(base64_string) % 4)).encode("ascii")
+    string_bytes = base64.urlsafe_b64decode(base64_bytes) 
+    string = string_bytes.decode("ascii")
+    return string
 
 
 async def get_messages(client, message_ids):