CrescendoDLL.PCSC.APDUEngine Class Reference

The CrescendoDLL.PCSC.APDUEngine class contains references to applet objects, their current properties and all the necessary internal methods to allow PCSC communication with the SmartCard. More...

Inheritance diagram for CrescendoDLL.PCSC.APDUEngine:

Public Member Functions
void	Dispose ()
	Releases all resources used by this instance.
void	EndTransaction ()
	Ends the current smart card transaction, releasing exclusive access while maintaining the token's state.
async Task	MaintainTransactionAsync (CancellationToken ct)
	Maintains an active smart card transaction by periodically checking the SCardStatus (in 2.5 second intervals).
void	StartTransaction ()
	Begins a smart card transaction, establishing exclusive access to the token.

Public Attributes
CommandApdu	LastCommand = default!
	Last APDU command send to the token.
string	LastError = default!
	String description of the last APDU error received from the token.
Response	LastResponse = default!
	Last APDU response received from the token.
byte[]	TokenATR
	ATR (Answer To Reset) message output of the token.
string	TokenName
	String name of the token.

Detailed Description

The CrescendoDLL.PCSC.APDUEngine class contains references to applet objects, their current properties and all the necessary internal methods to allow PCSC communication with the SmartCard.

Two construction modes determine which applets are wired:

• The Crescendo constructor (CrescendoDLL.PCSC.APDUEngine(string, CrescendoDLL.PCSC.PCSCImpl, string, byte[], bool)) and Token-based Crescendo factory register real lazy factories for every Crescendo applet — ACA, OATH, PIV, CardManager, FIDO Attestation, and FIDO Instance.
• The generic-FIDO constructor (CrescendoDLL.PCSC.APDUEngine(CrescendoDLL.Token, CrescendoDLL.PCSC.PCSCImpl)) is used for non-Crescendo authenticators. Only FIDO Instance is wired to a real applet; every other applet getter throws NotSupportedException

Member Function Documentation

Dispose()

void CrescendoDLL.PCSC.APDUEngine.Dispose ( )

inline

Releases all resources used by this instance.

This method:

• Ends any ongoing transaction
• Disconnects from the smart card reader, preserving the card's state
• Disposes of the PCSC implementation and reader objects
• Suppresses finalization

Successful disconnection is logged at DEBUG level. A non-Success SCardError from SCardReader.Disconnect is logged at WARN and swallowed — exceptions from System.IDisposable.Dispose are an antipattern and would mask any pending application exception that triggered the disposal.

References CrescendoDLL.PCSC.APDUEngine.EndTransaction().

Referenced by CrescendoDLL.SDKCore.Dispose().

EndTransaction()

void CrescendoDLL.PCSC.APDUEngine.EndTransaction ( )

inline

Ends the current smart card transaction, releasing exclusive access while maintaining the token's state.

Exceptions

Exception

Thrown if the transaction cannot be properly ended (SCardError != Success).

Uses SCardReaderDisposition.Leave to preserve the token's state after transaction completion. Successful execution is logged at DEBUG level.

Referenced by CrescendoDLL.PCSC.APDUEngine.Dispose().

MaintainTransactionAsync()

async Task CrescendoDLL.PCSC.APDUEngine.MaintainTransactionAsync ( CancellationToken  ct )

inline

Maintains an active smart card transaction by periodically checking the SCardStatus (in 2.5 second intervals).

Parameters

ct	CancellationToken used to terminate the keep-alive loop gracefully.

Exceptions

Exception

Thrown if the status check fails during the transaction maintenance.

Returns

A Task that represents the asynchronous operation.

This method prevents transaction timeouts by performing status checks every 2.5 seconds. It automatically terminates when cancellation is requested via the token.

StartTransaction()

void CrescendoDLL.PCSC.APDUEngine.StartTransaction ( )

inline

Begins a smart card transaction, establishing exclusive access to the token.

Exceptions

Exception

Thrown if the transaction cannot be started (SCardError != Success).

This method initiates a transaction that maintains exclusive access to the token until CrescendoDLL.PCSC.APDUEngine.EndTransaction is called. Successful execution is logged at DEBUG level.

Member Data Documentation

LastCommand

CommandApdu CrescendoDLL.PCSC.APDUEngine.LastCommand = default!

Last APDU command send to the token.

LastError

string CrescendoDLL.PCSC.APDUEngine.LastError = default!

String description of the last APDU error received from the token.

LastResponse

Response CrescendoDLL.PCSC.APDUEngine.LastResponse = default!

Last APDU response received from the token.

TokenATR

byte [] CrescendoDLL.PCSC.APDUEngine.TokenATR

ATR (Answer To Reset) message output of the token.

TokenName

string CrescendoDLL.PCSC.APDUEngine.TokenName

String name of the token.

Referenced by CrescendoDLL.SDKCore.ConfigureOATHSlot(), CrescendoDLL.SDKCore.ConfigureOCRASlot(), and CrescendoDLL.SDKCore.ConfigureStaticPassword().