commit cfa3015bcf1b55e44267c1086725501579aace46
author Harald Welte <laforge@osmocom.org> Fri Jul 22 17:12:27 2022 +0200
committer Harald Welte <laforge@osmocom.org> Sat Jul 23 12:17:21 2022 +0200
tree 71d20d0540117e4e9fc07d0119a6013ba89483f7
parent 1272129ea79ec3ba10b157b87a175b253cf65162

sysmocom_sja2: Prevent KeyError/None exception on encode

Fix a bug in the pySim.sysmocom_sja2 module, where we defined unnamed
bits in BitStruct without a default value causing exceptions like this:

	EXCEPTION of type 'KeyError' occurred with message: 'None'

Change-Id: Ib2da5adda4fae374ab14bb8100f338691aef719a
Closes: OS#5575

pySim/sysmocom_sja2.py

diff --git a/pySim/sysmocom_sja2.py b/pySim/sysmocom_sja2.py
index d00a2cb..53e6585 100644
--- a/pySim/sysmocom_sja2.py
+++ b/pySim/sysmocom_sja2.py
@@ -137,7 +137,7 @@
 class EF_SIM_AUTH_KEY(TransparentEF):
     def __init__(self, fid='6f20', name='EF.SIM_AUTH_KEY'):
         super().__init__(fid, name=name, desc='USIM authentication key')
-        CfgByte = BitStruct(Bit[2],
+        CfgByte = BitStruct(Padding(2),
                             'use_sres_deriv_func_2'/Bit,
                             'use_opc_instead_of_op'/Bit,
                             'algorithm'/Enum(Nibble, milenage=4, comp128v1=1, comp128v2=2, comp128v3=3))
@@ -192,7 +192,7 @@
 class EF_USIM_AUTH_KEY(TransparentEF):
     def __init__(self, fid='af20', name='EF.USIM_AUTH_KEY'):
         super().__init__(fid, name=name, desc='USIM authentication key')
-        CfgByte = BitStruct(Bit, 'only_4bytes_res_in_3g'/Bit,
+        CfgByte = BitStruct(Padding(1), 'only_4bytes_res_in_3g'/Bit,
                             'use_sres_deriv_func_2_in_3g'/Bit,
                             'use_opc_instead_of_op'/Bit,
                             'algorithm'/Enum(Nibble, milenage=4, sha1_aka=5, xor=15))
@@ -210,7 +210,7 @@
 class EF_USIM_AUTH_KEY_2G(TransparentEF):
     def __init__(self, fid='af22', name='EF.USIM_AUTH_KEY_2G'):
         super().__init__(fid, name=name, desc='USIM authentication key in 2G context')
-        CfgByte = BitStruct(Bit, 'only_4bytes_res_in_3g'/Bit,
+        CfgByte = BitStruct(Padding(1), 'only_4bytes_res_in_3g'/Bit,
                             'use_sres_deriv_func_2_in_3g'/Bit,
                             'use_opc_instead_of_op'/Bit,
                             'algorithm'/Enum(Nibble, milenage=4, comp128v1=1, comp128v2=2, comp128v3=3))