pySim-shell: Add suspend_uicc command

This is an optional command, and it is not supported by e.g.  sysmoISIM-SJA2

Change-Id: Icc726ffd672744e56cc8dd3762891af507942c1e

docs/shell.rst

@@ -156,6 +156,20 @@ close_channel
    :func: Iso7816Commands.close_chan_parser
 
 
+suspend_uicc
+~~~~~~~~~~~~
+This command allows you to perform the SUSPEND UICC command on the card.  This is a relatively
+recent power-saving addition to the UICC specifications, allowing for suspend/resume while maintaining
+state, as opposed to a full power-off (deactivate) and power-on (activate) of the card.
+
+The pySim command just sends that SUSPEND UICC command and doesn't perform the full related sequence
+including the electrical power down.
+
+.. argparse::
+   :module: pySim-shell
+   :func: Iso7816Commands.suspend_uicc_parser
+
+
 pySim commands
 --------------
 

pySim-shell.py

@@ -718,6 +718,20 @@ class Iso7816Commands(CommandSet):
 		fcp_dec = self._cmd.rs.status()
 		self._cmd.poutput_json(fcp_dec)
 
+	suspend_uicc_parser = argparse.ArgumentParser()
+	suspend_uicc_parser.add_argument('--min-duration-secs', type=int, default=60,
+									 help='Proposed minimum duration of suspension')
+	suspend_uicc_parser.add_argument('--max-duration-secs', type=int, default=24*60*60,
+									 help='Proposed maximum duration of suspension')
+
+	# not ISO7816-4 but TS 102 221
+	@cmd2.with_argparser(suspend_uicc_parser)
+	def do_suspend_uicc(self, opts):
+		"""Perform the SUSPEND UICC command. Only supported on some UICC."""
+		(duration, token, sw) = self._cmd.card._scc.suspend_uicc(min_len_secs=opts.min_duration_secs,
+																 max_len_secs=opts.max_duration_secs)
+		self._cmd.poutput('Negotiated Duration: %u secs, Token: %s, SW: %s' % (duration, token, sw))
+
 
 option_parser = argparse.ArgumentParser(prog='pySim-shell', description='interactive SIM card shell',
                                         formatter_class=argparse.ArgumentDefaultsHelpFormatter)

pySim/commands.py

@@ -23,7 +23,7 @@
 
 from construct import *
 from pySim.construct import LV
-from pySim.utils import rpad, b2h, h2b, sw_match, bertlv_encode_len
+from pySim.utils import rpad, b2h, h2b, sw_match, bertlv_encode_len, Hexstr, h2i
 from pySim.exceptions import SwMatchError
 
 class SimCardCommands(object):
@@ -448,3 +448,39 @@ class SimCardCommands(object):
 		data_length = len(payload) // 2
 		data, sw = self._tp.send_apdu(('80100000%02x' % data_length) + payload)
 		return (data, sw)
+
+	# ETSI TS 102 221 11.1.22
+	def suspend_uicc(self, min_len_secs:int=60, max_len_secs:int=43200):
+		"""Send SUSPEND UICC to the card."""
+		def encode_duration(secs:int) -> Hexstr:
+			if secs >= 10*24*60*60:
+				return '04%02x' % (secs // (10*24*60*60))
+			elif secs >= 24*60*60:
+				return '03%02x' % (secs // (24*60*60))
+			elif secs >= 60*60:
+				return '02%02x' % (secs // (60*60))
+			elif secs >= 60:
+				return '01%02x' % (secs // 60)
+			else:
+				return '00%02x' % secs
+		def decode_duration(enc:Hexstr) -> int:
+			time_unit = enc[:2]
+			length = h2i(enc[2:4])
+			if time_unit == '04':
+				return length * 10*24*60*60
+			elif time_unit == '03':
+				return length * 24*60*60
+			elif time_unit == '02':
+				return length * 60*60
+			elif time_unit == '01':
+				return length * 60
+			elif time_unit == '00':
+				return length
+			else:
+				raise ValueError('Time unit must be 0x00..0x04')
+		min_dur_enc = encode_duration(min_len_secs)
+		max_dur_enc = encode_duration(max_len_secs)
+		data, sw = self._tp.send_apdu_checksw('8076000004' + min_dur_enc + max_dur_enc)
+		negotiated_duration_secs = decode_duration(data[:4])
+		resume_token = data[4:]
+		return (negotiated_duration_secs, resume_token, sw)