Allow update_binary function to write more than 255 bytes
The T0 protocol (selected in transport/pcsc.py) does not support extended APDU, so 255 bytes is the maximum number of bytes that can be transmitted at a time. We can divide large data into 255 byte chunks. The read_binary function already has code to read more than 255 bytes, so we can just adapt it to the update_binary function.
Change-Id: Icc240d5c8c04198640eb118565ea99f10ba27466
diff --git a/pySim/commands.py b/pySim/commands.py
index 76b7cd5..9657162 100644
--- a/pySim/commands.py
+++ b/pySim/commands.py
@@ -170,11 +170,23 @@
return None, sw
self.select_path(ef)
- pdu = self.cla_byte + 'd6%04x%02x' % (offset, data_length) + data
- res = self._tp.send_apdu_checksw(pdu)
+ total_data = ''
+ total_sw = "9000"
+ chunk_offset = offset
+ while chunk_offset < data_length:
+ chunk_len = min(255, data_length - chunk_offset)
+ # chunk_offset is bytes, but data slicing is hex chars, so we need to multiply by 2
+ pdu = self.cla_byte + 'd6%04x%02x' % (chunk_offset, chunk_len) + data[chunk_offset*2 : (chunk_offset+chunk_len)*2]
+ chunk_data, chunk_sw = self._tp.send_apdu(pdu)
+ if chunk_sw == total_sw:
+ total_data += chunk_data
+ chunk_offset += chunk_len
+ else:
+ total_sw = chunk_sw
+ raise ValueError('Failed to write chunk (chunk_offset %d, chunk_len %d)' % (chunk_offset, chunk_len))
if verify:
self.verify_binary(ef, data, offset)
- return res
+ return total_data, total_sw
def verify_binary(self, ef, data:str, offset:int=0):
"""Verify contents of transparent EF.