NAME

Chipcard::PCSC - 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

AUTHORS / ACKNOWLEDGEMENT

 Lionel VICTOR <lionel.victor@unforgettable.com>
               <lionel.victor@free.fr>

 Ludovic ROUSSEAU <ludovic.rousseau@free.fr>