>From my blog http://ludovicrousseau.blogspot.com/
PCSC sample in Python<http://ludovicrousseau.blogspot.com/2010/04/pcsc-sample-in-python.html> InstallationThe wrapper project is hosted by sourceforge at http://pyscard.sourceforge.net/. The files (source code and installer for many different systems: Linux, Mac OS X, Windows) are available at http://sourceforge.net/projects/pyscard/files/.<http://sourceforge.net/projects/pyscard/files/> But if you have a Debian system it is easier to use: apt-get install python-pyscard The licence is Lesser General Public License either version 2.1 of the License, or (at your option) any later version. Low level API Source code *#! /usr/bin/env python* *from* smartcard.scard *import* * *import* smartcard.util SELECT = [0x00, 0xA4, 0x04, 0x00, 0x0A, 0xA0, 0x00, 0x00, 0x00, 0x62, 0x03, 0x01, 0x0C, 0x06, 0x01] COMMAND = [0x00, 0x00, 0x00, 0x00] *try*: hresult, hcontext = *SCardEstablishContext*(SCARD_SCOPE_USER) *if* hresult != SCARD_S_SUCCESS: *raise* *Exception*('Failed to establish context : ' + *SCardGetErrorMessage*(hresult)) *print* 'Context established!' *try*: hresult, readers = *SCardListReaders*(hcontext, []) *if* hresult != SCARD_S_SUCCESS: *raise* *Exception*('Failed to list readers: ' + *SCardGetErrorMessage*(hresult)) *print* 'PCSC Readers:', readers *if* *len*(readers) < 1: *raise* *Exception*('No smart card readers') reader = readers[0] *print* "Using reader:", reader *try*: hresult, hcard, dwActiveProtocol = *SCardConnect*(hcontext, reader, SCARD_SHARE_SHARED, SCARD_PROTOCOL_T0 | SCARD_PROTOCOL_T1) *if* hresult != SCARD_S_SUCCESS: *raise* *Exception*('Unable to connect: ' + *SCardGetErrorMessage*(hresult)) *print* 'Connected with active protocol', dwActiveProtocol *try*: hresult, response = *SCardTransmit*(hcard, dwActiveProtocol, SELECT) *if* hresult != SCARD_S_SUCCESS: *raise* *Exception*('Failed to transmit: ' + *SCardGetErrorMessage*(hresult)) *print* 'Select: ' + smartcard.util.*toHexString*(response, smartcard.util.HEX) hresult, response = *SCardTransmit*(hcard, dwActiveProtocol, COMMAND) *if* hresult != SCARD_S_SUCCESS: *raise* *Exception*('Failed to transmit: ' + *SCardGetErrorMessage*(hresult)) *print* 'Command: ' + smartcard.util.*toHexString*(response, smartcard.util.HEX) *finally*: hresult = *SCardDisconnect*(hcard, SCARD_UNPOWER_CARD) *if* hresult != SCARD_S_SUCCESS: *raise* *Exception*('Failed to disconnect: ' + *SCardGetErrorMessage*(hresult)) *print* 'Disconnected' *except* Exception, message: *print* "Exception:", message *finally*: hresult = *SCardReleaseContext*(hcontext) *if* hresult != SCARD_S_SUCCESS: *raise* *Exception*('Failed to release context: ' + *SCardGetErrorMessage*(hresult)) *print* 'Released context.' *except* Exception, message: *print* "Exception:", message *import* sys *if* 'win32' == sys.platform: *print* 'press Enter to continue' sys.stdin.*read*(1) Output $ ./sample1.py Context established! PCSC Readers: ['Gemalto GemPC Pinpad 00 00'] Using reader: Gemalto GemPC Pinpad 00 00 Connected with active protocol 2 Select: 0x90 0x00 Command: 0x48 0x65 0x6C 0x6C 0x6F 0x20 0x77 0x6F 0x72 0x6C 0x64 0x21 0x90 0x00 Disconnected Released context. Comments Using the low level API is very verbose. You have access to each PCSC function from Python. For example I use this API to write some Unitary Tests for pcsc-lite ( http://svn.debian.org/wsvn/pcsclite/trunk/PCSC/UnitaryTests/#_trunk_PCSC_UnitaryTests_)<http://svn.debian.org/wsvn/pcsclite/trunk/PCSC/UnitaryTests/#_trunk_PCSC_UnitaryTests_> But why use a high level language if the code is as complex as in C? High level API Source code *#! /usr/bin/env python* *from* smartcard.System *import* readers *# define the APDUs used in this script* SELECT = [0x00, 0xA4, 0x04, 0x00, 0x0A, 0xA0, 0x00, 0x00, 0x00, 0x62, 0x03, 0x01, 0x0C, 0x06, 0x01] COMMAND = [0x00, 0x00, 0x00, 0x00] *# get all the available readers* r = *readers*() *print* "Available readers:", r reader = r[0] *print* "Using:", reader connection = reader.*createConnection*() connection.*connect*() data, sw1, sw2 = connection.*transmit*(SELECT) *print* data *print* "Select Applet: %02X %02X" % (sw1, sw2) data, sw1, sw2 = connection.*transmit*(COMMAND) *print* data *print* "Command: %02X %02X" % (sw1, sw2) Output $ ./sample2.py Available readers: ['Gemalto GemPC Pinpad 00 00'] Using: Gemalto GemPC Pinpad 00 00 [] Select Applet: 90 00 [72, 101, 108, 108, 111, 32, 119, 111, 114, 108, 100, 33] Command: 90 00 Comments The code is much more compact and easy to read. In particular you do not have to explicitly check for the results. In case of error at the PC/SC level the caller will receive a smartcard.Exceptions.* exception. For example if no card is present in the first reader you get: $ ./sample2.py Available readers: ['Gemalto GemPC Pinpad 00 00'] Using: Gemalto GemPC Pinpad 00 00 Traceback (most recent call last): File "./sample2.py", line 18, in connection.connect() File "/usr/lib/python2.5/site-packages/smartcard/CardConnectionDecorator.py", line 53, in connect self.component.connect( protocol, mode, disposition ) File "/usr/lib/python2.5/site-packages/smartcard/pcsc/PCSCCardConnection.py", line 111, in connect raise CardConnectionException( 'Unable to connect with protocol: ' + dictProtocol[pcscprotocol] + '. ' + SCardGetErrorMessage(hresult) ) smartcard.Exceptions.CardConnectionException: 'Smartcard Exception: Unable to connect with protocol: T0 or T1. No smart card inserted.!' It is easy to use a try: block to catch the exception and do whatever you need to do in such case. Conclusion Python is the language is use nowadays to write programs if I can choose the language. So of course pyscard is the PC/SC wrapper I use. -- Dr. Ludovic Rousseau
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