Chipcard::PCSC(3) Smart card reader interface library

SYNOPSIS


my $hContext = new Chipcard::PCSC();
@ReadersList = $hContext->ListReaders ();
$hContext->GetStatusChange(\@readers_states, $timeout);
$apdu = Chipcard::PCSC::array_to_ascii(@apdu);
@apdu = Chipcard::PCSC::ascii_to_array($apdu);
$hContext = undef;

DESCRIPTION

The PCSC module implements the Chipcard::PCSC class. Objects of this class are used to communicate with the PCSC-lite daemon (see pcscd(1) for more information).

PC/SC represents an abstraction layer to smart card readers. It provides a communication layer with a wide variety of smart card readers through a standardized API.

A PCSC object can be used to communicate with more than one reader through Chipcard::PCSC::Card objects. Please read Chipcard::PCSC::Card for extended information on how to talk to a smart card reader.

A PCSC object uses the following property: "$pcsc_object->{hContext}" the context returned by the pcsc library

CONSTRUCTORS

The following methods can be used to construct a PCSC object:
  • $hContext = new Chipcard::PCSC($scope, $remote_host);
  • $scope is the scope of the connection to the PC/SC daemon. It can be any of the following:

     $Chipcard::PCSC::SCARD_SCOPE_USER     (not used by PCSClite);
     $Chipcard::PCSC::SCARD_SCOPE_TERMINAL (not used by PCSClite);
     $Chipcard::PCSC::SCARD_SCOPE_SYSTEM   Services on the local machine;
     $Chipcard::PCSC::SCARD_SCOPE_GLOBAL   Services on a remote host.
    
  • $remote_host is the host name of the remote machine to contact. It is only used when $scope is equal to $Chipcard::PCSC::SCARD_SCOPE_GLOBAL. A null value means localhost.
  • $hContext = new Chipcard::PCSC($scope);

    This method is equivalent to:

     $hContext = new Chipcard::PCSC($scope, 0);
    
  • $hContext = new Chipcard::PCSC();

    This method is equivalent to:

     $hContext = new Chipcard::PCSC($Chipcard::PCSC::SCARD_SCOPE_SYSTEM, 0);
    

CONSTRUCTION FAILURE

Chipcard::PCSC constructors return an "undef" value when the object can not be created. $Chipcard::PCSC::errno can be used to get more information about the error. (See section ``ERROR HANDLING'' below for more information)

Chipcard::PCSC METHODS

Here is a list of all the methods that can be used with a PCSC object.
  • hContext->ListReaders( $group );

    This method returns the available readers in the given $group. If omitted, $group defaults to a null value meaning ``all groups''. Please note that as of this writing, $group can safely be omitted as it is not used by PCSClite.

    The return value upon successful completion is an array of strings: one string by available reader. If an error occurred, the undef value is returned and $Chipcard::PCSC::errno should be used to get more information about the error. (See section ``ERROR HANDLING'' below for more information). The following example describes the use of ListReaders:

     $hContext = new Chipcard::PCSC();
     die ("Can't create the PCSC object: $Chipcard::PCSC::errno\n")
            unless (defined $hContext);
     @ReadersList = $hContext->ListReaders ();
     die ("Can't get readers' list: $Chipcard::PCSC::errno\n")
            unless (defined($ReadersList[0]));
     $, = "\n  ";
     print @ReadersList . "\n";
    
  • $hContext->GetStatusChange(\@readers_states, $timeout);

    The method "$hContext->GetStatusChange(\@readers_states, $timeout)" uses a reference to a list of hashes.

     # create the list or readers to watch
     map { push @readers_states, ({'reader_name'=>"$_"}) } @ReadersList;
     @StatusResult = $hContext->GetStatusChange(\@readers_states);
    

    The keys of the hash are: 'reader_name', 'current_state', 'event_state' and 'ATR'.

    To detect a status change you have to first get the status and then copy the 'event_state' in the 'current_state'. The method will return when both states are different or a timeout occurs.

     @StatusResult = $hContext->GetStatusChange(\@readers_states);
     foreach $reader (@readers_states)
     {
       $reader->{current_state} = $reader->{event_state};
     }
     @StatusResult = $hContext->GetStatusChange(\@readers_states);
    
  • $hContext->GetStatusChange(\@readers_states);

    This method is equivalent to:

     $hContext->GetStatusChange(\@readers_states, 0xFFFFFFFF);
    

    The timeout is set to infinite.

  • $apdu_ref = Chipcard::PCSC::ascii_to_array($apdu);

    The method "Chipcard::PCSC::Card::Transmit()" uses references to arrays as in and out parameters. The "Chipcard::PCSC::ascii_to_array()" is used to transform an APDU in ASCII format to a reference to an array in the good format.

    Example:

     $SendData = Chipcard::PCSC::ascii_to_array("00 A4 01 00 02 01 00");
    
  • $apdu = Chipcard::PCSC::array_to_ascii($apdu_ref);

    This method is used to convert the result of a "Chipcard::PCSC::Card::Transmit()" into ASCII format.

    Example:

     $RecvData = $hCard->Transmit($SendData);
     print Chipcard::PCSC::array_to_ascii($RecvData);
    

ERROR HANDLING

All functions from PCSC objects save the return value in a global variable called $Chipcard::PCSC::errno. This variable therefore holds the latest status of PCSC.

It is a double-typed magical variable that behaves just like $!. This means that it both holds a numerical value describing the error and the corresponding string. The numerical value may change from a system to another as it depends on the PCSC library...

Here is a small example of how to use it:

 $hContext = new Chipcard::PCSC();
 die ("Can't create the PCSC object: $Chipcard::PCSC::errno\n")
     unless (defined $hContext);

In case the last call was successful, $Chipcard::PCSC::errno contains the "SCARD_S_SUCCESS" status. Here is a list of all possible error codes. They are defined as read-only variables with in the PCSC module:

 $Chipcard::PCSC::SCARD_S_SUCCESS
 $Chipcard::PCSC::SCARD_E_CANCELLED
 $Chipcard::PCSC::SCARD_E_CANT_DISPOSE
 $Chipcard::PCSC::SCARD_E_CARD_UNSUPPORTED
 $Chipcard::PCSC::SCARD_E_DUPLICATE_READER
 $Chipcard::PCSC::SCARD_E_INSUFFICIENT_BUFFER
 $Chipcard::PCSC::SCARD_E_INVALID_ATR
 $Chipcard::PCSC::SCARD_E_INVALID_HANDLE
 $Chipcard::PCSC::SCARD_E_INVALID_PARAMETER
 $Chipcard::PCSC::SCARD_E_INVALID_TARGET
 $Chipcard::PCSC::SCARD_E_INVALID_VALUE
 $Chipcard::PCSC::SCARD_E_NO_MEMORY
 $Chipcard::PCSC::SCARD_E_NO_SERVICE
 $Chipcard::PCSC::SCARD_E_NO_SMARTCARD
 $Chipcard::PCSC::SCARD_E_NOT_READY
 $Chipcard::PCSC::SCARD_E_NOT_TRANSACTED
 $Chipcard::PCSC::SCARD_E_PCI_TOO_SMALL
 $Chipcard::PCSC::SCARD_E_PROTO_MISMATCH
 $Chipcard::PCSC::SCARD_E_READER_UNAVAILABLE
 $Chipcard::PCSC::SCARD_E_READER_UNSUPPORTED
 $Chipcard::PCSC::SCARD_E_SERVICE_STOPPED
 $Chipcard::PCSC::SCARD_E_SHARING_VIOLATION
 $Chipcard::PCSC::SCARD_E_SYSTEM_CANCELLED
 $Chipcard::PCSC::SCARD_E_TIMEOUT
 $Chipcard::PCSC::SCARD_E_UNKNOWN_CARD
 $Chipcard::PCSC::SCARD_E_UNKNOWN_READER
 $Chipcard::PCSC::SCARD_E_UNSUPPORTED_FEATURE
 $Chipcard::PCSC::SCARD_W_REMOVED_CARD
 $Chipcard::PCSC::SCARD_W_RESET_CARD
 $Chipcard::PCSC::SCARD_W_UNPOWERED_CARD
 $Chipcard::PCSC::SCARD_W_UNRESPONSIVE_CARD
 $Chipcard::PCSC::SCARD_W_UNSUPPORTED_CARD

PCSClite users will also be able to use the following (PCSClite specific) codes:

 $Chipcard::PCSC::SCARD_INSERTED
 $Chipcard::PCSC::SCARD_REMOVED
 $Chipcard::PCSC::SCARD_RESET
 $Chipcard::PCSC::SCARD_SCOPE_GLOBAL

In addition, the wrapper defines:

 $Chipcard::PCSC::SCARD_P_ALREADY_CONNECTED
 $Chipcard::PCSC::SCARD_P_NOT_CONNECTED

COPYRIGHT

(C) Lionel VICTOR & Ludovic ROUSSEAU, 2001-2004, GNU GPL (C) Ludovic ROUSSEAU, 2005-2008, GNU GPL

AUTHORS / ACKNOWLEDGEMENT

 Lionel VICTOR <[email protected]>
               <lionel.victor@free.fr>
 Ludovic ROUSSEAU <[email protected]>