laforge has submitted this change. ( https://gerrit.osmocom.org/c/pysim/+/36957?usp=email )
Change subject: esim.saip: Introduce ProfileElement derived classes ......................................................................
esim.saip: Introduce ProfileElement derived classes
It's rather useful to have derived classes implementing specific functions related to that SAIP profile type. Let's introruce that concept and a first example for securityDomain, where methods allow checking/adding/removing support for SCPs.
Change-Id: I0929cc704b2aabddbc2ddee79ab8b674b1ed4691 --- M pySim/esim/saip/__init__.py 1 file changed, 62 insertions(+), 8 deletions(-)
Approvals: osmith: Looks good to me, but someone else must approve laforge: Looks good to me, approved Jenkins Builder: Verified
diff --git a/pySim/esim/saip/__init__.py b/pySim/esim/saip/__init__.py index b8e41ce..fc86b63 100644 --- a/pySim/esim/saip/__init__.py +++ b/pySim/esim/saip/__init__.py @@ -26,6 +26,8 @@ from pySim.construct import build_construct from pySim.esim import compile_asn1_subdir from pySim.esim.saip import templates +from pySim.tlv import BER_TLV_IE +from pySim.global_platform.uicc import UiccSdInstallParams
asn1 = compile_asn1_subdir('saip')
@@ -134,6 +136,9 @@ """Class representing a Profile Element (PE) within a SAIP Profile.""" FILE_BEARING = ['mf', 'cd', 'telecom', 'usim', 'opt-usim', 'isim', 'opt-isim', 'phonebook', 'gsm-access', 'csim', 'opt-csim', 'eap', 'df-5gs', 'df-saip', 'df-snpn', 'df-5gprose', 'iot', 'opt-iot'] + def __init__(self, decoded = None): + self.decoded = decoded + def _fixup_sqnInit_dec(self) -> None: """asn1tools has a bug when working with SEQUENCE OF that have DEFAULT values. Let's work around this.""" @@ -161,12 +166,6 @@ # none of the fields were initialized with a non-default (non-zero) value, so we can skip it del self.decoded['sqnInit']
- def parse_der(self, der: bytes) -> None: - """Parse a sequence of PE and store the result in instance attributes.""" - self.type, self.decoded = asn1.decode('ProfileElement', der) - # work around asn1tools bug regarding DEFAULT for a SEQUENCE OF - self._fixup_sqnInit_dec() - @property def header_name(self) -> str: """Return the name of the header field within the profile element.""" @@ -195,12 +194,24 @@ @classmethod def from_der(cls, der: bytes) -> 'ProfileElement': """Construct an instance from given raw, DER encoded bytes.""" - inst = cls() - inst.parse_der(der) + pe_type, decoded = asn1.decode('ProfileElement', der) + if pe_type == 'securityDomain': + inst = ProfileElementSD(decoded) + else: + inst = ProfileElement(decoded) + inst.type = pe_type + # work around asn1tools bug regarding DEFAULT for a SEQUENCE OF + inst._fixup_sqnInit_dec() + # run any post-decoder a derived class may have + if hasattr(inst, '_post_decode'): + inst._post_decode() return inst
def to_der(self) -> bytes: """Build an encoded DER representation of the instance.""" + # run any pre-encoder a derived class may have + if hasattr(self, '_pre_encode'): + self._pre_encode() # work around asn1tools bug regarding DEFAULT for a SEQUENCE OF self._fixup_sqnInit_enc() return asn1.encode('ProfileElement', (self.type, self.decoded)) @@ -208,6 +219,35 @@ def __str__(self) -> str: return self.type
+class ProfileElementSD(ProfileElement): + """Class representing a securityDomain ProfileElement.""" + type = 'securityDomain' + + class C9(BER_TLV_IE, tag=0xC9, nested=UiccSdInstallParams): + pass + + def _post_decode(self): + self.usip = self.C9() + self.usip.from_bytes(self.decoded['instance']['applicationSpecificParametersC9']) + + def _pre_encode(self): + self.decoded['instance']['applicationSpecificParametersC9'] = self.usip.to_bytes() + + def has_scp(self, scp: int) -> bool: + """Determine if SD Installation parameters already specify given SCP.""" + return self.usip.nested_collection.has_scp(scp) + + def add_scp(self, scp: int, i: int): + """Add given SCP (and i parameter) to list of SCP of the Security Domain Install Params. + Example: add_scp(0x03, 0x70) for SCP03, or add_scp(0x02, 0x55) for SCP02.""" + self.usip.nested_collection.add_scp(scp, i) + self._pre_encode() + + def remove_scp(self, scp: int): + """Remove given SCP from list of SCP of the Security Domain Install Params.""" + self.usip.nested_collection.remove_scp(scp) + self._pre_encode() +
def bertlv_first_segment(binary: bytes) -> Tuple[bytes, bytes]: """obtain the first segment of a binary concatenation of BER-TLV objects.
-
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