Move all PC/SC specific stuff to a separate class structure for readers (thus preparing the way for non-PC/SC-readers)

This commit should be known as "Holy excessive layering, batman!"

cards/generic_card.py

@@ -130,12 +130,8 @@ class Card:
     }
     TLV_OBJECTS[TLV_utils.context_FCI] = TLV_OBJECTS[TLV_utils.context_FCP]
     
-    def __init__(self, card):
-        if not hasattr(card, "connection"):
-            self.card = card
-        else:
-            self.card = card.connection
-            self.cardservice = card
+    def __init__(self, reader):
+        self.reader = reader
         
         self._i = 0
         self.last_apdu = None
@@ -198,19 +194,13 @@ class Card:
         "show_applications": cmd_show_applications,
     }
     
-    PROTOMAP = {
-        0: smartcard.scard.SCARD_PCI_T0,
-        1: smartcard.scard.SCARD_PCI_T1,
-    }
     def _real_send(self, apdu):
         apdu_binary = apdu.render()
         
         if DEBUG:
             print ">> " + utils.hexdump(apdu_binary, indent = 3)
         
-        apdu_bytes = map(lambda x: ord(x), apdu_binary)
-        data, sw1, sw2 = self.card.transmit(apdu_bytes, protocol=self.PROTOMAP[self.get_protocol()])
-        result_binary = map(lambda x: chr(x), data + [sw1,sw2])
+        result_binary = self.reader.transceive(apdu_binary)
         result = R_APDU(result_binary)
         
         self.last_apdu = apdu
@@ -258,20 +248,16 @@ class Card:
         if purpose is None: purpose = Card.PURPOSE_SUCCESS
         return self.match_statusword(self.STATUS_MAP[purpose], sw)
     
-    def _get_atr(card):
-        if hasattr(card, "connection"):
-            ATR = smartcard.util.toASCIIString(card.connection.getATR())
-        else:
-            ATR = smartcard.util.toASCIIString(card.getATR())
-        return ATR
+    def _get_atr(reader):
+        return reader.get_ATR()
     _get_atr = staticmethod(_get_atr)
     
     def get_atr(self):
-        return self._get_atr(self.card)
+        return self._get_atr(self.reader)
     
-    def can_handle(cls, card):
+    def can_handle(cls, reader):
         """Determine whether this class can handle a given card/connection object."""
-        ATR = cls._get_atr(card)
+        ATR = cls._get_atr(reader)
         def match_list(atr, list):
             for (knownatr, mask) in list:
                 if mask is None:
@@ -330,9 +316,6 @@ class Card:
             else:
                 return "%s (SW %s)" % (retval, binascii.b2a_hex(self.last_sw))
     
-    def get_protocol(self):
-        hresult, reader, state, protocol, atr = smartcard.scard.SCardStatus( self.card.component.hcard )
-        return ((protocol == smartcard.scard.SCARD_PROTOCOL_T0) and (0,) or (1,))[0]
     
     def get_driver_name(self):
         if len(self.DRIVER_NAME) > 1:
@@ -343,8 +326,6 @@ class Card:
     
     def close_card(self):
         "Disconnect from a card"
-        self.card.disconnect()
-        if hasattr(self, "cardservice"):
-            del self.cardservice
-        del self.card
+        self.reader.disconnect()
+        del self.reader
 

cyberflex-shell.py

@@ -1,7 +1,7 @@
 #!/usr/bin/env python
 # -*- coding: iso-8859-1 -*-
 
-import crypto_utils, utils, cards, os, re, binascii, sys, exceptions, traceback, getopt, datetime
+import crypto_utils, utils, cards, readers, os, re, binascii, sys, exceptions, traceback, getopt, datetime
 from shell import Shell
 
 class Logger(object):
@@ -94,7 +94,8 @@ class Cyberflex_Shell(Shell):
     
     def cmd_listreaders(self):
         "List the available readers"
-        list_readers()
+        for i, (name, obj) in enumerate(readers.list_readers()):
+            print "%i: %s" % (i,name)
     
     def cmd_enc(self, *args):
         "Encrypt or decrypt with openssl-like interface"
@@ -156,7 +157,7 @@ class Cyberflex_Shell(Shell):
 
     def cmd_atr(self, *args):
         """Print the ATR of the currently inserted card."""
-        print "ATR: %s" % utils.hexdump(self.card.card.status()['ATR'], short=True)
+        print "ATR: %s" % utils.hexdump(self.card.reader.get_ATR(), short=True)
     
     def cmd_save_response(self, file_name, start = None, end = None):
         "Save the data in the last response to a file. start and end are optional"
@@ -268,7 +269,7 @@ class Cyberflex_Shell(Shell):
         sys.stdout = self.logger
         print "Logging to %s" % filename
         try:
-            self.logger.println( "# ATR of currently inserted card is: %s" % utils.hexdump(self.card.get_atr(), short=True) )
+            self.logger.println( "# ATR of currently inserted card is: %s" % utils.hexdump(self.card.reader.get_ATR(), short=True) )
         except (KeyboardInterrupt, SystemExit):
             raise
         except:
@@ -341,8 +342,8 @@ class Cyberflex_Shell(Shell):
         if reader is None:
             reader = self.reader
         
-        card_object = utils.CommandLineArgumentHelper.connect_to(reader)
-        self.card = cards.new_card_object(card_object)
+        reader_object = readers.connect_to(reader)
+        self.card = cards.new_card_object(reader_object)
         
         self.unregister_commands(self, self.NOCARD_COMMANDS)
         self.register_commands(self, self.CARD_COMMANDS)

readers.py

@@ -0,0 +1,130 @@
+try:
+    import smartcard, smartcard.CardRequest
+except ImportError:
+    print >>sys.stderr, """Could not import smartcard module. Please install pyscard 
+from http://pyscard.sourceforge.net/
+If you can't install pyscard and want to continue using 
+pycsc you'll need to downgrade to SVN revision 246.
+"""
+    raise
+class Smartcard_Reader(object):
+    def list_readers():
+        "Return a list of tuples: (reader name, implementing object)"
+        return []
+    
+    def connect(self):
+        "Create a connection to this reader"
+        raise NotImplementedError, "Please implement in a sub-class"
+    
+    def get_ATR(self):
+        "Get the ATR of the inserted card as a binary string"
+        raise NotImplementedError, "Please implement in a sub-class"
+
+    def transceive(self, data):
+        "Send a binary blob, receive a binary blob"
+        raise NotImplementedError, "Please implement in a sub-class"
+
+    def disconnect(self):
+        "Disconnect from the card and release all resources"
+        raise NotImplementedError, "Please implement in a sub-class"
+
+class PCSC_Reader(Smartcard_Reader):
+    def __init__(self, reader):
+        self._reader = reader
+        self._name = str(reader)
+        self._cardservice = None
+    
+    name = property(lambda self: self._name, None, None, "The human readable name of the reader")
+    
+    def list_readers(cls):
+        return [ (str(r), cls(r)) for r in smartcard.System.readers() ]
+    list_readers = classmethod(list_readers)
+    
+    def connect(self):
+        unpatched = False
+        printed = False
+        while True:
+            try:
+                if not unpatched:
+                    cardrequest = smartcard.CardRequest.CardRequest( readers=[self._reader], timeout=0.1 )
+                else:
+                    cardrequest = smartcard.CardRequest.CardRequest( readers=[self._reader], timeout=1 )
+                
+                self._cardservice = cardrequest.waitforcard()
+                self._cardservice.connection.connect()
+                break
+            except TypeError:
+                unpatched = True
+            except (KeyboardInterrupt, SystemExit):
+                raise
+            except smartcard.Exceptions.CardRequestException:
+                if sys.exc_info()[1].message.endswith("Command timeout."):
+                    if not printed:
+                        print "Please insert card ..."
+                        printed = True
+                else:
+                    raise
+            except smartcard.Exceptions.CardRequestTimeoutException:
+                if not printed:
+                    print "Please insert card ..."
+                    printed = True
+            except smartcard.Exceptions.NoCardException:
+                print "Card is mute or absent. Please retry."
+    
+    def get_ATR(self):
+        return smartcard.util.toASCIIString(self._cardservice.connection.getATR())
+    
+    def get_protocol(self):
+        hresult, reader, state, protocol, atr = smartcard.scard.SCardStatus( self._cardservice.connection.component.hcard )
+        return ((protocol == smartcard.scard.SCARD_PROTOCOL_T0) and (0,) or (1,))[0]
+
+    PROTOMAP = {
+        0: smartcard.scard.SCARD_PCI_T0,
+        1: smartcard.scard.SCARD_PCI_T1,
+    }
+    
+    def transceive(self, data):
+        data_bytes = map(lambda x: ord(x), data)
+        data, sw1, sw2 = self._cardservice.connection.transmit(data_bytes, protocol=self.PROTOMAP[self.get_protocol()])
+        result_binary = map(lambda x: chr(x), data + [sw1,sw2])
+        return result_binary
+    
+    def disconnect(self):
+        self._cardservice.connection.disconnect()
+        del self._cardservice
+        self._cardservice = None
+
+def list_readers():
+    "Collect readers from all known drivers"
+    readers = PCSC_Reader.list_readers()
+    return readers
+
+def connect_to(reader):
+    "Open the connection to a reader"
+    
+    readerObject = None
+    readers = list_readers()
+    
+    if isinstance(reader, int) or reader.isdigit():
+        reader = int(reader)
+        readerObject = readers[reader][1]
+    else:
+        for i, name, obj in readers:
+            if str(name).startswith(reader):
+                readerObject = obj
+    
+    if readerObject is None:
+        readerObject = readers[0][1]
+    
+    print "Using reader: %s" % readerObject.name
+    
+    readerObject.connect()
+    
+    from utils import hexdump
+
+    print "ATR:          %s" % hexdump(readerObject.get_ATR(), short = True)
+    return readerObject
+
+if __name__ == "__main__":
+    list_readers()
+    

utils.py

@@ -1,13 +1,4 @@
-import string, binascii, sys, re, getopt
-try:
-    import smartcard, smartcard.CardRequest
-except ImportError:
-    print >>sys.stderr, """Could not import smartcard module. Please install pyscard 
-from http://pyscard.sourceforge.net/
-If you can't install pyscard and want to continue using 
-pycsc you'll need to downgrade to SVN revision 246.
-"""
-    raise
+import string, binascii, sys, re, getopt, readers
 
 class CommandLineArgumentHelper:
     OPTIONS = "r:l"
@@ -15,65 +6,13 @@ class CommandLineArgumentHelper:
     exit_now = False
     reader = None
     
-    def list_readers():
-        for index, name in enumerate(smartcard.System.readers()):
-            print "%i: %s" % (index, name)
-    list_readers = staticmethod(list_readers)
-    
     def connect(self):
         "Open the connection to a card"
         
         if self.reader is None:
             self.reader = 0
         
-        return self.connect_to(self.reader)
-    
-    def connect_to(reader):
-        "Open the connection to a reader"
-        
-        readerObject = None
-        
-        if isinstance(reader, int) or reader.isdigit():
-            reader = int(reader)
-            readerObject = smartcard.System.readers()[reader]
-        else:
-            for r in smartcard.System.readers():
-                if str(r).startswith(reader):
-                    readerObject = r
-        
-        if readerObject is None:
-            readerObject = smartcard.System.readers()[0]
-        
-        print "Using reader: %s" % readerObject
-        unpatched = False
-        printed = False
-        while True:
-            try:
-                if not unpatched:
-                    cardrequest = smartcard.CardRequest.CardRequest( readers=[readerObject], timeout=0.1 )
-                else:
-                    cardrequest = smartcard.CardRequest.CardRequest( readers=[readerObject], timeout=1 )
-                
-                cardservice = cardrequest.waitforcard()
-                cardservice.connection.connect()
-                break
-            except TypeError:
-                unpatched = True
-            except (KeyboardInterrupt, SystemExit):
-                raise
-            except smartcard.Exceptions.CardRequestException:
-                if sys.exc_info()[1].message.endswith("Command timeout."):
-                    if not printed:
-                        print "Please insert card ..."
-                        printed = True
-                else:
-                    raise
-            except smartcard.Exceptions.NoCardException:
-                print "Card is mute or absent. Please retry."
-        
-        print "ATR:          %s" % hexdump(smartcard.util.toASCIIString(cardservice.connection.getATR()), short = True)
-        return cardservice
-    connect_to = staticmethod(connect_to)
+        return readers.connect_to(self.reader)
     
     def getopt(self, argv, opts="", long_opts=[]):
         "Wrapper around getopt.gnu_getopt. Handles common arguments, returns everything else."
@@ -85,7 +24,8 @@ class CommandLineArgumentHelper:
             if option in ("-r","--reader"):
                 self.reader = value
             elif option in ("-l","--list-readers"):
-                self.list_readers()
+                for i, (name, obj) in enumerate(readers.list_readers()):
+                    print "%i: %s" % (i,name)
                 self.exit_now = True
             else:
                 unrecognized.append( (option, value) )