From 0c40a2245b79f53d1de94d2807e2763b28adbb27 Mon Sep 17 00:00:00 2001
From: Harald Welte <laforge@osmocom.org>
Date: Sat, 13 Jul 2024 22:58:44 +0200
Subject: [PATCH] pySim.ota: Raise exception if encoded length would exceed 140
 bytes

SMS cannot exceed 140 bytes, and TS 31.115 explicitly states that larger
messages must use multi-part SMS, which we don't yet implement here.

Change-Id: I8a1543838be2add1c3cfdf7155676cf2b9827e6e
---
 pySim/ota.py | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/pySim/ota.py b/pySim/ota.py
index 00a4b6bc..751461a0 100644
--- a/pySim/ota.py
+++ b/pySim/ota.py
@@ -386,6 +386,9 @@ class OtaDialectSms(OtaDialect):
 
         #print("envelope_data: %s" % b2h(envelope_data))
 
+        if len(envelope_data) > 140:
+            raise ValueError('Cannot encode command in a single SMS; Fragmentation not implemented')
+
         return envelope_data
 
     def decode_cmd(self, otak: OtaKeyset, encoded: bytes) -> Tuple[bytes, dict, bytes]: