transport: Pass status word interpreter to exception handler

Prior to this patch, any SwMatchError raised within the 'transport'
would not be interpreted.

EXCEPTION of type 'SwMatchError' occurred with message: 'SW match failed! Expected 9000 and got 6982.'

vs (now)

EXCEPTION of type 'SwMatchError' occurred with message: 'SW match failed! Expected 9000 and got 6982: Command not allowed - Security status not satisfied'

Change-Id: I08b7f2b6bd422f7f2f36094bc8a29b187ff882a6
diff --git a/pySim-shell.py b/pySim-shell.py
index ae8a5a2..e73ec35 100755
--- a/pySim-shell.py
+++ b/pySim-shell.py
@@ -433,6 +433,8 @@
 	profile.add_application(CardApplicationISIM)
 
 	rs = RuntimeState(card, profile)
+	# inform the transport that we can do context-specific SW interpretation
+	sl.set_sw_interpreter(rs)
 
 	# FIXME: do this dynamically
 	rs.mf.add_file(DF_TELECOM())
diff --git a/pySim/transport/__init__.py b/pySim/transport/__init__.py
index 24d7521..fb8f31d 100644
--- a/pySim/transport/__init__.py
+++ b/pySim/transport/__init__.py
@@ -28,6 +28,12 @@
 class LinkBase(object):
 	"""Base class for link/transport to card."""
 
+	sw_interpreter = None
+
+	def set_sw_interpreter(self, interp):
+		"""Set an (optional) status word interpreter."""
+		self.sw_interpreter = interp
+
 	def wait_for_card(self, timeout:int=None, newcardonly:bool=False):
 		"""Wait for a card and connect to it
 
@@ -103,7 +109,7 @@
 		rv = self.send_apdu(pdu)
 
 		if not sw_match(rv[1], sw):
-			raise SwMatchError(rv[1], sw.lower())
+			raise SwMatchError(rv[1], sw.lower(), self.sw_interpreter)
 		return rv
 
 def init_reader(opts) -> Optional[LinkBase]: