commands: add features to verify data written to files

When writing to files we often just write without making sure that the
actual file contents actually written. Lets add features to do a
read-after-write verification when writing to files.

Change-Id: I7be842004102f4998af376790c97647c107be3d5

pySim/commands.py

@@ -122,10 +122,18 @@ class SimCardCommands(object):
 		pdu = self.cla_byte + 'b0%04x%02x' % (offset, (min(256, length) & 0xff))
 		return self._tp.send_apdu(pdu)
 
-	def update_binary(self, ef, data, offset=0):
+	def update_binary(self, ef, data, offset=0, verify=False):
 		self.select_file(ef)
 		pdu = self.cla_byte + 'd6%04x%02x' % (offset, len(data) // 2) + data
-		return self._tp.send_apdu_checksw(pdu)
+		res = self._tp.send_apdu_checksw(pdu)
+		if verify:
+			self.verify_binary(ef, data, offset)
+		return res
+
+	def verify_binary(self, ef, data, offset=0):
+		res = self.read_binary(ef, len(data) // 2, offset)
+		if res[0].lower() != data.lower():
+			raise ValueError('Binary verification failed (expected %s, got %s)' % (data.lower(), res[0].lower()))
 
 	def read_record(self, ef, rec_no):
 		r = self.select_file(ef)
@@ -133,7 +141,7 @@ class SimCardCommands(object):
 		pdu = self.cla_byte + 'b2%02x04%02x' % (rec_no, rec_length)
 		return self._tp.send_apdu(pdu)
 
-	def update_record(self, ef, rec_no, data, force_len=False):
+	def update_record(self, ef, rec_no, data, force_len=False, verify=False):
 		r = self.select_file(ef)
 		if not force_len:
 			rec_length = self.__record_len(r)
@@ -142,7 +150,15 @@ class SimCardCommands(object):
 		else:
 			rec_length = len(data) // 2
 		pdu = (self.cla_byte + 'dc%02x04%02x' % (rec_no, rec_length)) + data
-		return self._tp.send_apdu_checksw(pdu)
+		res = self._tp.send_apdu_checksw(pdu)
+		if verify:
+			self.verify_record(ef, rec_no, data)
+		return res
+
+	def verify_record(self, ef, rec_no, data):
+		res = self.read_record(ef, rec_no)
+		if res[0].lower() != data.lower():
+			raise ValueError('Record verification failed (expected %s, got %s)' % (data.lower(), res[0].lower()))
 
 	def record_size(self, ef):
 		r = self.select_file(ef)