dexter has uploaded this change for review.

View Change

commands: get rid of cla4lchan

The send_apdu* methods now support lchan patching, so there is no longer
a need for computing the class byte manually (which is prone get forgotten)
before calling a send_apdu*. It is now enough to supply an APDU that has
a class byte with the default channel selected. This also means we do not
need cla4lchan anymore, so let's restruture the code and get rid of it
completely.

Related: OS#6531
Change-Id: Ia795f3c16a8875484fce3b44e61497d5aa52b447
---
M pySim/commands.py
M pySim/euicc.py
2 files changed, 11 insertions(+), 24 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/pysim refs/changes/36/37936/1
diff --git a/pySim/commands.py b/pySim/commands.py
index 3a7fe47..9e231f1 100644
--- a/pySim/commands.py
+++ b/pySim/commands.py
@@ -81,8 +81,8 @@

@property
def cla_byte(self) -> Hexstr:
- """Return the (cached) patched default CLA byte for this card."""
- return self._cla4lchan
+ """Return the lchan patched default CLA value for this card."""
+ return cla_with_lchan(self._cla_byte, self.lchan_nr)

@property
def max_cmd_len(self) -> int:
@@ -96,19 +96,6 @@
def cla_byte(self, new_val: Hexstr):
"""Set the (raw, without lchan) default CLA value for this card."""
self._cla_byte = new_val
- # compute cached result
- self._cla4lchan = cla_with_lchan(self._cla_byte, self.lchan_nr)
-
- def cla4lchan(self, cla: Hexstr) -> Hexstr:
- """Compute the lchan-patched value of the given CLA value. If no CLA
- value is provided as argument, the lchan-patched version of the SimCardCommands._cla_byte
- value is used. Most commands will use the latter, while some wish to override it and
- can pass it as argument here."""
- if not cla:
- # return cached result to avoid re-computing this over and over again
- return self._cla4lchan
- else:
- return cla_with_lchan(cla, self.lchan_nr)

def send_apdu(self, pdu: Hexstr, apply_lchan:bool = True) -> ResTuple:
"""Sends an APDU and auto fetch response data
@@ -122,7 +109,7 @@
sw : string (in hex) of status word (ex. "9000")
"""
if apply_lchan:
- pdu = self.cla4lchan(pdu[0:2]) + pdu[2:]
+ pdu = cla_with_lchan(pdu[0:2], self.lchan_nr) + pdu[2:]
if self.scp:
return self.scp.send_apdu_wrapper(self._tp.send_apdu, pdu)
else:
@@ -142,7 +129,7 @@
sw : string (in hex) of status word (ex. "9000")
"""
if apply_lchan:
- pdu = self.cla4lchan(pdu[0:2]) + pdu[2:]
+ pdu = cla_with_lchan(pdu[0:2], self.lchan_nr) + pdu[2:]
if self.scp:
return self.scp.send_apdu_wrapper(self._tp.send_apdu_checksw, pdu, sw)
else:
@@ -517,9 +504,9 @@
# TS 102 221 Section 11.3.1 low-level helper
def _retrieve_data(self, tag: int, first: bool = True) -> ResTuple:
if first:
- pdu = self.cla4lchan('80') + 'cb008001%02x' % (tag)
+ pdu = '80cb008001%02x' % (tag)
else:
- pdu = self.cla4lchan('80') + 'cb000000'
+ pdu = '80cb000000'
return self.send_apdu_checksw(pdu)

def retrieve_data(self, ef: Path, tag: int) -> ResTuple:
@@ -549,7 +536,7 @@
p1 = 0x00
if isinstance(data, (bytes, bytearray)):
data = b2h(data)
- pdu = self.cla4lchan('80') + 'db00%02x%02x%s' % (p1, len(data)//2, data)
+ pdu = '80db00%02x%02x%s' % (p1, len(data)//2, data)
return self.send_apdu_checksw(pdu)

def set_data(self, ef, tag: int, value: str, verify: bool = False, conserve: bool = False) -> ResTuple:
@@ -592,7 +579,7 @@
if len(rand) != 32:
raise ValueError('Invalid rand')
self.select_path(['3f00', '7f20'])
- return self.send_apdu_checksw(self.cla4lchan('a0') + '88000010' + rand, sw='9000')
+ return self.send_apdu_checksw('a088000010' + rand, sw='9000')

def authenticate(self, rand: Hexstr, autn: Hexstr, context: str = '3g') -> ResTuple:
"""Execute AUTHENTICATE (USIM/ISIM).
@@ -625,7 +612,7 @@

def status(self) -> ResTuple:
"""Execute a STATUS command as per TS 102 221 Section 11.1.2."""
- return self.send_apdu_checksw(self.cla4lchan('80') + 'F2000000')
+ return self.send_apdu_checksw('80F2000000')

def deactivate_file(self) -> ResTuple:
"""Execute DECATIVATE FILE command as per TS 102 221 Section 11.1.14."""
@@ -645,7 +632,7 @@

def resize_file(self, payload: Hexstr) -> ResTuple:
"""Execute RESIZE FILE command as per TS 102 222 Section 6.10"""
- return self.send_apdu_checksw(self.cla4lchan('80') + 'd40000%02x%s' % (len(payload)//2, payload))
+ return self.send_apdu_checksw('80d40000%02x%s' % (len(payload)//2, payload))

def delete_file(self, fid: Hexstr) -> ResTuple:
"""Execute DELETE FILE command as per TS 102 222 Section 6.4"""
diff --git a/pySim/euicc.py b/pySim/euicc.py
index d0cb682..8bd1ae4 100644
--- a/pySim/euicc.py
+++ b/pySim/euicc.py
@@ -322,7 +322,7 @@
def store_data(scc: SimCardCommands, tx_do: Hexstr, exp_sw: SwMatchstr ="9000") -> Tuple[Hexstr, SwHexstr]:
"""Perform STORE DATA according to Table 47+48 in Section 5.7.2 of SGP.22.
Only single-block store supported for now."""
- capdu = '%sE29100%02x%s' % (scc.cla4lchan('80'), len(tx_do)//2, tx_do)
+ capdu = '80E29100%02x%s' % (len(tx_do)//2, tx_do)
return scc.send_apdu_checksw(capdu, exp_sw)

@staticmethod

To view, visit change 37936. To unsubscribe, or for help writing mail filters, visit settings.

Gerrit-MessageType: newchange
Gerrit-Project: pysim
Gerrit-Branch: master
Gerrit-Change-Id: Ia795f3c16a8875484fce3b44e61497d5aa52b447
Gerrit-Change-Number: 37936
Gerrit-PatchSet: 1
Gerrit-Owner: dexter <pmaier@sysmocom.de>