laforge has uploaded this change for review. ( https://gerrit.osmocom.org/c/pysim/+/27129 )
Change subject: ts_102_221: Handle nested security condition data objects ......................................................................
ts_102_221: Handle nested security condition data objects
ISO 7816-4 Section 5.4.3.2 "Expanded Format" permits for nesting of security conditions using boolean operators OR, AND, NOT.
Let's implement decoding and encoding of these.
An example decoded looks like:
pySIM-shell (MF/EF.ARR)> read_record_decoded 1 [ [ { "access_mode": [ "activate_file_or_record", "deactivate_file_or_record", "update_erase" ] }, { "or": [ { "control_reference_template": "ADM1" }, { "control_reference_template": "ADM2" } ] } ], [ { "access_mode": [ "read_search_compare" ] }, { "always": null } ] ]
Prior to this patch, pySim would raise "ValueError: Unknown Tag 0xa0 in bytearray"
Change-Id: Icb09cf3a90303a86fc77406b8b0806b5c926f1be Closes: OS#5411 --- M pySim/ts_102_221.py 1 file changed, 30 insertions(+), 1 deletion(-)
git pull ssh://gerrit.osmocom.org:29418/pysim refs/changes/29/27129/1
diff --git a/pySim/ts_102_221.py b/pySim/ts_102_221.py index 7cc3025..88855bf 100644 --- a/pySim/ts_102_221.py +++ b/pySim/ts_102_221.py @@ -470,8 +470,37 @@
Always_DO = TL0_DataObject('always', 'Always', 0x90) Never_DO = TL0_DataObject('never', 'Never', 0x97) + +class Nested_DO(DataObject): + """A DO that nests another DO/Choice/Sequence""" + def __init__(self, name, tag, choice): + super().__init__(name, tag=tag) + self.children = choice + def from_bytes(self, binary:bytes): + remainder = binary + self.decoded = [] + while remainder: + rc, remainder = self.children.decode(remainder) + self.decoded.append(rc) + return self.decoded + def to_bytes(self): + ret = b'' + for e in self.decoded: + ret ++ self.children.encode(e) + return ret + +OR_Template = DataObjectChoice('or_template', 'OR-Template', + members=[Always_DO, Never_DO, SecCondByte_DO(), SecCondByte_DO(0x9e), CRT_DO()]) +OR_DO = Nested_DO('or', 0xa0, OR_Template) +AND_Template = DataObjectChoice('and_template', 'AND-Template', + members=[Always_DO, Never_DO, SecCondByte_DO(), SecCondByte_DO(0x9e), CRT_DO()]) +AND_DO = Nested_DO('and', 0xa7, AND_Template) +NOT_Template = DataObjectChoice('not_template', 'NOT-Template', + members=[Always_DO, Never_DO, SecCondByte_DO(), SecCondByte_DO(0x9e), CRT_DO()]) +NOT_DO = Nested_DO('not', 0xaf, NOT_Template) SC_DO = DataObjectChoice('security_condition', 'Security Condition', - members=[Always_DO, Never_DO, SecCondByte_DO(), SecCondByte_DO(0x9e), CRT_DO()]) + members=[Always_DO, Never_DO, SecCondByte_DO(), SecCondByte_DO(0x9e), CRT_DO(), + OR_DO, AND_DO, NOT_DO])
# TS 102 221 Section 13.1 class EF_DIR(LinFixedEF):
-
laforge