laforge has submitted this change. ( https://gerrit.osmocom.org/c/pysim/+/33078 ) Change subject: SJA5: Proper encode/decode of TUAK data in EF.USIM_AUTH_KEY ...................................................................... SJA5: Proper encode/decode of TUAK data in EF.USIM_AUTH_KEY Unfortunately, TUAK requires a number of additional (and differently-sized) parameters, so the format of EF.USIM_AUTH_KEY differs significantly depending on TUAK or non-TUAK case. Change-Id: I0dcfe05777510fb34973dc2259b137133d8e199d --- M pySim/sysmocom_sja2.py 1 file changed, 46 insertions(+), 3 deletions(-) Approvals: laforge: Looks good to me, approved fixeria: Looks good to me, but someone else must approve Jenkins Builder: Verified diff --git a/pySim/sysmocom_sja2.py b/pySim/sysmocom_sja2.py index d1f643e..8b1fc04 100644 --- a/pySim/sysmocom_sja2.py +++ b/pySim/sysmocom_sja2.py @@ -183,13 +183,43 @@ 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') + Algorithm = Enum(Nibble, milenage=4, sha1_aka=5, tuak=6, xor=15) 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, tuak=6, xor=15)) + 'sres_deriv_func_2_in_3g'/Mapping(Bit, {1:0, 2:1}), + 'use_opc_instead_of_op'/Mapping(Bit, {False:0, True:1}), + 'algorithm'/Algorithm) self._construct = Struct('cfg'/CfgByte, 'key'/HexAdapter(Bytes(16)), 'op_opc' /HexAdapter(Bytes(16))) + # TUAK has a rather different layout for the data, so we define a different + # construct below and use explicit _{decode,encode}_bin() methods for separating + # the TUAK and non-TUAK situation + CfgByteTuak = BitStruct(Padding(1), + 'key_length'/Mapping(Bit, {128:0, 256:1}), + 'sres_deriv_func_in_3g'/Mapping(Bit, {1:0, 2:1}), + 'use_opc_instead_of_op'/Mapping(Bit, {False:0, True:1}), + 'algorithm'/Algorithm) + TuakCfgByte = BitStruct(Padding(1), + 'ck_and_ik_size'/Mapping(Bit, {128:0, 256:1}), + 'mac_size'/Mapping(BitsInteger(3), {64:0, 128:1, 256:2}), + 'res_size'/Mapping(BitsInteger(3), {32:0, 64:1, 128:2, 256:3})) + self._constr_tuak = Struct('cfg'/CfgByteTuak, + 'tuak_cfg'/TuakCfgByte, + 'num_of_keccak_iterations'/Int8ub, + 'op_opc'/HexAdapter(Bytes(32)), + 'k'/HexAdapter(Bytes(32))) + + def _decode_bin(self, raw_bin_data: bytearray) -> dict: + if raw_bin_data[0] & 0x0F == 0x06: + return parse_construct(self._constr_tuak, raw_bin_data) + else: + return parse_construct(self._construct, raw_bin_data) + + def _encode_bin(self, abstract_data: dict) -> bytearray: + if abstract_data['cfg']['algorithm'] == 'tuak': + return self._constr_tuak.build(abstract_data) + else: + return self._construct.build(abstract_data) class EF_USIM_AUTH_KEY_2G(TransparentEF): -- To view, visit https://gerrit.osmocom.org/c/pysim/+/33078 To unsubscribe, or for help writing mail filters, visit https://gerrit.osmocom.org/settings Gerrit-Project: pysim Gerrit-Branch: master Gerrit-Change-Id: I0dcfe05777510fb34973dc2259b137133d8e199d Gerrit-Change-Number: 33078 Gerrit-PatchSet: 3 Gerrit-Owner: laforge <laforge@osmocom.org> Gerrit-Reviewer: Jenkins Builder Gerrit-Reviewer: dexter <pmaier@sysmocom.de> Gerrit-Reviewer: fixeria <vyanitskiy@sysmocom.de> Gerrit-Reviewer: laforge <laforge@osmocom.org> Gerrit-MessageType: merged