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SJA2: Implement DF.SYSTEM/EF.0348_KEY using construct

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This implicitly adds support for JSON->binary encoding, not just
decoding (previous code predating construct support).

Change-Id: I0994d9f66a504dd3c60b43ed5cf6645515dcbc6a
This commit is contained in:
Harald Welte
2023-05-27 20:08:09 +02:00
committed by laforge
parent ba6d6ab64f
commit 954ce95a16
2 changed files with 29 additions and 13 deletions
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22
pySim/sysmocom_sja2.py
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@@ -86,19 +86,15 @@ class EF_MILENAGE_CFG(TransparentEF):
class EF_0348_KEY(LinFixedEF):
def __init__(self, fid='6f22', name='EF.0348_KEY', desc='TS 03.48 OTA Keys'):
super().__init__(fid, name=name, desc=desc, rec_len=(27, 35))
def _decode_record_bin(self, raw_bin_data, **kwargs):
u = unpack('!BBB', raw_bin_data[0:3])
key_algo = (u[2] >> 6) & 1
key_length = ((u[2] >> 3) & 3) * 8
return {'sec_domain': u[0],
'key_set_version': u[1],
'key_type': key_type2str[u[2] & 3],
'key_length': key_length,
'algorithm': key_algo2str[key_algo],
'mac_length': mac_length[(u[2] >> 7)],
'key': raw_bin_data[3:key_length].hex()
}
KeyLenAndType = BitStruct('mac_length'/Mapping(Bit, {8:0, 4:1}),
'algorithm'/Enum(Bit, des=0, aes=1),
'key_length'/MultiplyAdapter(BitsInteger(3), 8),
'_rfu'/BitsRFU(1),
'key_type'/Enum(BitsInteger(2), kic=0, kid=1, kik=2, any=3))
self._construct = Struct('security_domain'/Int8ub,
'key_set_version'/Int8ub,
'key_len_and_type'/KeyLenAndType,
'key'/HexAdapter(Bytes(this.key_len_and_type.key_length)))
class EF_0348_COUNT(LinFixedEF):