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
diff --git a/pySim/ts_102_221.py b/pySim/ts_102_221.py
index 7cc3025..71d5b82 100644
--- a/pySim/ts_102_221.py
+++ b/pySim/ts_102_221.py
@@ -470,8 +470,35 @@
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) -> list:
+ remainder = binary
+ self.decoded = []
+ while remainder:
+ rc, remainder = self.children.decode(remainder)
+ self.decoded.append(rc)
+ return self.decoded
+ def to_bytes(self) -> bytes:
+ encoded = [self.children.encode(d) for d in self.decoded]
+ return b''.join(encoded)
+
+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):