From 9853e247a234e4365414ed20ea9d462819d12f42 Mon Sep 17 00:00:00 2001
From: Harald Welte <laforge@osmocom.org>
Date: Sat, 10 Apr 2021 19:08:25 +0200
Subject: [PATCH] ts_31_102.py: switch EF.Keys from imperative to declarative
 codec

Change-Id: I215a61c1e44ee2c5df70a8ca96344b4dd4d93c00
---
 pySim/ts_31_102.py | 9 +++------
 1 file changed, 3 insertions(+), 6 deletions(-)

diff --git a/pySim/ts_31_102.py b/pySim/ts_31_102.py
index cdb66124..320a2cdf 100644
--- a/pySim/ts_31_102.py
+++ b/pySim/ts_31_102.py
@@ -269,6 +269,8 @@ EF_USIM_ADF_map = {
 ######################################################################
 
 from struct import unpack, pack
+from construct import *
+from pySim.construct import HexAdapter
 from pySim.filesystem import *
 from pySim.ts_51_011 import EF_IMSI, EF_xPLMNwAcT, EF_SPN, EF_CBMI, EF_ACC, EF_PLMNsel, EF_AD
 from pySim.ts_51_011 import EF_CBMID, EF_CBMIR
@@ -416,12 +418,7 @@ class EF_Keys(TransparentEF):
     def __init__(self, fid='6f08', sfid=0x08, name='EF.Keys', size={33,33},
                  desc='Ciphering and Integrity Keys'):
         super().__init__(fid, sfid=sfid, name=name, desc=desc, size=size)
-    def _decode_bin(self, in_bin):
-        return {'ksi': in_bin[0],
-                'ck': b2h(in_bin[1:17]),
-                'ik': b2h(in_bin[17:33])}
-    def _encode_bin(self, in_json):
-        return h2b(in_json['ksi']) + h2b(in_json['ck']) + h2b(in_json['ik'])
+        self._construct = Struct('ksi'/Int8ub, 'ck'/HexAdapter(Bytes(16)), 'ik'/HexAdapter(Bytes(16)))
 
 # TS 31.103 Section 4.2.7
 class EF_UST(TransparentEF):