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ts_102_221: Implement File Descriptor using construct

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This automatically adds encoding support, which is needed for upcoming
CREATE FILE support.

Change-Id: Ia40dba4aab6ceb9d81fd170f7efa8dad1f9b43d0
This commit is contained in:
Harald Welte
2022-02-13 17:52:28 +01:00
parent ee670bc1c6
commit 747a978478
5 changed files with 50 additions and 43 deletions
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47
pySim/ts_102_221.py
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@@ -18,6 +18,7 @@ along with this program. If not, see <http://www.gnu.org/licenses/>.
"""
from construct import *
from construct import Optional as COptional
from pySim.construct import *
from pySim.utils import *
from pySim.filesystem import *
@@ -87,34 +88,22 @@ class TotalFileSize(BER_TLV_IE, tag=0x81):
# ETSI TS 102 221 11.1.1.4.3
class FileDescriptor(BER_TLV_IE, tag=0x82):
def _from_bytes(self, in_bin: bytes):
out = {}
ft_dict = {
0: 'working_ef',
1: 'internal_ef',
7: 'df'
}
fs_dict = {
0: 'no_info_given',
1: 'transparent',
2: 'linear_fixed',
6: 'cyclic',
0x39: 'ber_tlv',
}
fdb = in_bin[0]
ftype = (fdb >> 3) & 7
if fdb & 0xbf == 0x39:
fstruct = 0x39
else:
fstruct = fdb & 7
out['shareable'] = True if fdb & 0x40 else False
out['file_type'] = ft_dict[ftype] if ftype in ft_dict else ftype
out['structure'] = fs_dict[fstruct] if fstruct in fs_dict else fstruct
if len(in_bin) >= 5:
out['record_len'] = int.from_bytes(in_bin[2:4], 'big')
out['num_of_rec'] = int.from_bytes(in_bin[4:5], 'big')
self.decoded = out
return self.decoded
class BerTlvAdapter(Adapter):
def _parse(self, obj, context, path):
if obj == 0x39:
return 'ber_tlv'
raise ValidationError
def _build(self, obj, context, path):
if obj == 'ber_tlv':
return 0x39
raise ValidationError
FDB = Select(BitStruct(Const(0, Bit), 'shareable'/Flag, 'structure'/BerTlvAdapter(Const(0x39, BitsInteger(6)))),
BitStruct(Const(0, Bit), 'shareable'/Flag, 'file_type'/Enum(BitsInteger(3), working_ef=0, internal_ef=1, df=7),
'structure'/Enum(BitsInteger(3), no_info_given=0, transparent=1, linear_fixed=2, cyclic=6))
)
_construct = Struct('file_descriptor_byte'/FDB, Const(b'\x21'),
'record_len'/COptional(Int16ub), 'num_of_rec'/COptional(Int16ub))
# ETSI TS 102 221 11.1.1.4.4
class FileIdentifier(BER_TLV_IE, tag=0x83):
@@ -668,7 +657,7 @@ class EF_ARR(LinFixedEF):
@cmd2.with_argparser(LinFixedEF.ShellCommands.read_recs_dec_parser)
def do_read_arr_records(self, opts):
"""Read + decode all EF.ARR records in flattened, human-friendly form."""
num_of_rec = self._cmd.rs.selected_file_fcp['file_descriptor']['num_of_rec']
num_of_rec = self._cmd.rs.selected_file_num_of_rec()
# collect all results in list so they are rendered as JSON list when printing
data_list = []
for recnr in range(1, 1 + num_of_rec):