integrate 'construct' python library
'construct' is a declarative symmetric encoder/decoder for user
specified binary formats. It should come in extremely handy in
tools like pySim.
We start the integration by adding transport methods for transceiving
APDUs with built-in encoding of the command data and decoding of the
response data.
Change-Id: Ibf457aa8b9480a8db5979defcfafd67674303f6c
diff --git a/pySim/transport/__init__.py b/pySim/transport/__init__.py
index 96ad974..290bc7c 100644
--- a/pySim/transport/__init__.py
+++ b/pySim/transport/__init__.py
@@ -6,10 +6,12 @@
from typing import Optional
from pySim.exceptions import *
-from pySim.utils import sw_match
+from pySim.construct import filter_dict
+from pySim.utils import sw_match, b2h, h2b, i2h
#
# Copyright (C) 2009-2010 Sylvain Munaut <tnt@246tNt.com>
+# Copyright (C) 2021 Harald Welte <laforge@osmocom.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
@@ -127,6 +129,52 @@
raise SwMatchError(rv[1], sw.lower(), self.sw_interpreter)
return rv
+ def send_apdu_constr(self, cla, ins, p1, p2, cmd_constr, cmd_data, resp_constr):
+ """Build and sends an APDU using a 'construct' definition; parses response.
+
+ Args:
+ cla : string (in hex) ISO 7816 class byte
+ ins : string (in hex) ISO 7816 instruction byte
+ p1 : string (in hex) ISO 7116 Parameter 1 byte
+ p2 : string (in hex) ISO 7116 Parameter 2 byte
+ cmd_cosntr : defining how to generate binary APDU command data
+ cmd_data : command data passed to cmd_constr
+ resp_cosntr : defining how to decode binary APDU response data
+ Returns:
+ Tuple of (decoded_data, sw)
+ """
+ cmd = cmd_constr.build(cmd_data) if cmd_data else ''
+ p3 = i2h([len(cmd)])
+ pdu = ''.join([cla, ins, p1, p2, p3, b2h(cmd)])
+ (data, sw) = self.send_apdu(pdu)
+ if data:
+ # filter the resulting dict to avoid '_io' members inside
+ rsp = filter_dict(resp_constr.parse(h2b(data)))
+ else:
+ rsp = None
+ return (rsp, sw)
+
+ def send_apdu_constr_checksw(self, cla, ins, p1, p2, cmd_constr, cmd_data, resp_constr,
+ sw_exp="9000"):
+ """Build and sends an APDU using a 'construct' definition; parses response.
+
+ Args:
+ cla : string (in hex) ISO 7816 class byte
+ ins : string (in hex) ISO 7816 instruction byte
+ p1 : string (in hex) ISO 7116 Parameter 1 byte
+ p2 : string (in hex) ISO 7116 Parameter 2 byte
+ cmd_cosntr : defining how to generate binary APDU command data
+ cmd_data : command data passed to cmd_constr
+ resp_cosntr : defining how to decode binary APDU response data
+ exp_sw : string (in hex) of status word (ex. "9000")
+ Returns:
+ Tuple of (decoded_data, sw)
+ """
+ (rsp, sw) = self.send_apdu_constr(cla, ins, p1, p2, cmd_constr, cmd_data, resp_constr)
+ if not sw_match(sw, sw_exp):
+ raise SwMatchError(sw, sw_exp.lower(), self.sw_interpreter)
+ return (rsp, sw)
+
def init_reader(opts, **kwargs) -> Optional[LinkBase]:
"""
Init card reader driver