APDU



javacard.framework
Class APDU

java.lang.Object
  extended by javacard.framework.APDU

public final class APDU
extends Object

Application Protocol Data Unit (APDU) is the communication format between the card and the off-card applications. The format of the APDU is defined in ISO specification 7816-4.

This class only supports messages which conform to the structure of command and response defined in ISO 7816-4. The behavior of messages which use proprietary structure of messages ( for example with header CLA byte in range 0xD0-0xFE ) is undefined. This class does not support extended length fields.

The APDU object is owned by the Java Card runtime environment. The APDU class maintains a byte array buffer which is used to transfer incoming APDU header and data bytes as well as outgoing data. The buffer length must be at least 133 bytes ( 5 bytes of header and 128 bytes of data ). The Java Card runtime environment must zero out the APDU buffer before each new message received from the CAD.

The Java Card runtime environment designates the APDU object as a temporary Java Card runtime environment Entry Point Object (See Runtime Specification for the Java Card Platform, section 6.2.1 for details). A temporary Java Card runtime environment Entry Point Object can be accessed from any applet context. References to these temporary objects cannot be stored in class variables or instance variables or array components.

The Java Card runtime environment similarly marks the APDU buffer as a global array (See Runtime Specification for the Java Card Platform, section 6.2.2 for details). A global array can be accessed from any applet context. References to global arrays cannot be stored in class variables or instance variables or array components.

The applet receives the APDU instance to process from the Java Card runtime environment in the Applet.process(APDU) method, and the first five bytes [ CLA, INS, P1, P2, P3 ] are available in the APDU buffer.

The APDU class API is designed to be transport protocol independent. In other words, applets can use the same APDU methods regardless of whether the underlying protocol in use is T=0 or T=1 (as defined in ISO 7816-3).

The incoming APDU data size may be bigger than the APDU buffer size and may therefore need to be read in portions by the applet. Similarly, the outgoing response APDU data size may be bigger than the APDU buffer size and may need to be written in portions by the applet. The APDU class has methods to facilitate this.

For sending large byte arrays as response data, the APDU class provides a special method sendBytesLong() which manages the APDU buffer.

 // The purpose of this example is to show most of the methods
 // in use and not to depict any particular APDU processing

 public void process(APDU apdu){
  // ...
  byte[] buffer = apdu.getBuffer();
  byte cla = buffer[ISO7816.OFFSET_CLA];
  byte ins = buffer[ISO7816.OFFSET_INS];
  ...
  // assume this command has incoming data
  // Lc tells us the incoming apdu command length
  short bytesLeft = (short) (buffer[ISO7816.OFFSET_LC] & 0x00FF);
  if (bytesLeft < (short)55) ISOException.throwIt( ISO7816.SW_WRONG_LENGTH );

  short readCount = apdu.setIncomingAndReceive();
  while ( bytesLeft > 0){
      // process bytes in buffer[5] to buffer[readCount+4];
      bytesLeft -= readCount;
      readCount = apdu.receiveBytes ( ISO7816.OFFSET_CDATA );
      }
  //
  //...
  //
  // Note that for a short response as in the case illustrated here
  // the three APDU method calls shown : setOutgoing(),setOutgoingLength() & sendBytes()
  // could be replaced by one APDU method call : setOutgoingAndSend().

  // construct the reply APDU
  short le = apdu.setOutgoing();
  if (le < (short)2) ISOException.throwIt( ISO7816.SW_WRONG_LENGTH );
  apdu.setOutgoingLength( (short)3 );

  // build response data in apdu.buffer[ 0.. outCount-1 ];
  buffer[0] = (byte)1; buffer[1] = (byte)2; buffer[3] = (byte)3;
  apdu.sendBytes ( (short)0 , (short)3 );
  // return good complete status 90 00
  }
 
The APDU class also defines a set of STATE_.. constants which represent the various processing states of the APDUobject based on the methods invoked and the state of the data transfers. The getCurrentState() method returns the current state.

Note that the state number assignments are ordered as follows: STATE_INITIAL < STATE_PARTIAL_INCOMING < STATE_FULL_INCOMING < STATE_OUTGOING < STATE_OUTGOING_LENGTH_KNOWN < STATE_PARTIAL_OUTGOING < STATE_FULL_OUTGOING.

The following are processing error states and have negative state number assignments : STATE_ERROR_NO_T0_GETRESPONSE, STATE_ERROR_T1_IFD_ABORT, STATE_ERROR_IO and STATE_ERROR_NO_T0_REISSUE.

See Also:
APDUException, ISOException

Field Summary
static byte PROTOCOL_MEDIA_CONTACTLESS_TYPE_A
          Transport protocol Media - Contactless Type A
static byte PROTOCOL_MEDIA_CONTACTLESS_TYPE_B
          Transport protocol Media - Contactless Type B
static byte PROTOCOL_MEDIA_DEFAULT
          Transport protocol Media - Contacted Asynchronous Half Duplex
static byte PROTOCOL_MEDIA_MASK
          Media nibble mask in protocol byte
static byte PROTOCOL_MEDIA_USB
          Transport protocol Media - USB
static byte PROTOCOL_T0
          ISO 7816 transport protocol type T=0.
static byte PROTOCOL_T1
          This constant is used to denote both the ISO 7816 transport protocol type T=1 and the variant for contactless cards defined in ISO 14443-4.
static byte PROTOCOL_TYPE_MASK
          Type nibble mask in protocol byte
static byte STATE_ERROR_IO
          This error state of a APDU object occurs when an APDUException with reason code APDUException.IO_ERROR has been thrown
static byte STATE_ERROR_NO_T0_GETRESPONSE
          This error state of a APDU object occurs when an APDUException with reason code APDUException.NO_T0_GETRESPONSE has been thrown.
static byte STATE_ERROR_NO_T0_REISSUE
          This error state of a APDU object occurs when an APDUException with reason code APDUException.NO_T0_REISSUE has been thrown.
static byte STATE_ERROR_T1_IFD_ABORT
          This error state of a APDU object occurs when an APDUException with reason code APDUException.T1_IFD_ABORT has been thrown.
static byte STATE_FULL_INCOMING
          This is the state of a APDU object when all the incoming data been received.
static byte STATE_FULL_OUTGOING
          This is the state of a APDU object when all outbound data has been transferred.
static byte STATE_INITIAL
          This is the state of a new APDU object when only the command header is valid.
static byte STATE_OUTGOING
          This is the state of a new APDU object when data transfer mode is outbound but length is not yet known.
static byte STATE_OUTGOING_LENGTH_KNOWN
          This is the state of a APDU object when data transfer mode is outbound and outbound length is known.
static byte STATE_PARTIAL_INCOMING
          This is the state of a APDU object when incoming data has partially been received.
static byte STATE_PARTIAL_OUTGOING
          This is the state of a APDU object when some outbound data has been transferred but not all.
 
Method Summary
 byte[] getBuffer()
          Returns the APDU buffer byte array.
static byte getCLAChannel()
          Returns the logical channel number associated with the current APDU command based on the CLA byte.
static APDU getCurrentAPDU()
          This method is called to obtain a reference to the current APDU object.
static byte[] getCurrentAPDUBuffer()
          This method is called to obtain a reference to the current APDU buffer.
 byte getCurrentState()
          This method returns the current processing state of the APDU object.
static short getInBlockSize()
          Returns the configured incoming block size.
 byte getNAD()
          Returns the Node Address byte (NAD) in T=1 protocol, and 0 in T=0 protocol.
static short getOutBlockSize()
          Returns the configured outgoing block size.
static byte getProtocol()
          Returns the ISO 7816 transport protocol type, T=1 or T=0 in the low nibble and the transport media in the upper nibble in use.
 short receiveBytes(short bOff)
           
 void reset()
          clear internal state of the APDU
 void sendBytes(short bOff, short len)
           
 void sendBytesLong(byte[] outData, short bOff, short len)
          Sends len more bytes from outData byte array starting at specified offset bOff.
 short setIncomingAndReceive()
          This is the primary receive method.
 short setOutgoing()
          This method is used to set the data transfer direction to outbound and to obtain the expected length of response (Le).
 void setOutgoingAndSend(short bOff, short len)
          This is the "convenience" send method.
 void setOutgoingLength(short len)
          Sets the actual length of response data.
 short setOutgoingNoChaining()
          This method is used to set the data transfer direction to outbound without using BLOCK CHAINING (See ISO 7816-3/4) and to obtain the expected length of response (Le).
static void waitExtension()
          Requests additional processing time from CAD.
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Field Detail

STATE_INITIAL

public static final byte STATE_INITIAL
This is the state of a new APDU object when only the command header is valid.

See Also:
Constant Field Values

STATE_PARTIAL_INCOMING

public static final byte STATE_PARTIAL_INCOMING
This is the state of a APDU object when incoming data has partially been received.

See Also:
Constant Field Values

STATE_FULL_INCOMING

public static final byte STATE_FULL_INCOMING
This is the state of a APDU object when all the incoming data been received.

See Also:
Constant Field Values

STATE_OUTGOING

public static final byte STATE_OUTGOING
This is the state of a new APDU object when data transfer mode is outbound but length is not yet known.

See Also:
Constant Field Values

STATE_OUTGOING_LENGTH_KNOWN

public static final byte STATE_OUTGOING_LENGTH_KNOWN
This is the state of a APDU object when data transfer mode is outbound and outbound length is known.

See Also:
Constant Field Values

STATE_PARTIAL_OUTGOING

public static final byte STATE_PARTIAL_OUTGOING
This is the state of a APDU object when some outbound data has been transferred but not all.

See Also:
Constant Field Values

STATE_FULL_OUTGOING

public static final byte STATE_FULL_OUTGOING
This is the state of a APDU object when all outbound data has been transferred.

See Also:
Constant Field Values

STATE_ERROR_NO_T0_GETRESPONSE

public static final byte STATE_ERROR_NO_T0_GETRESPONSE
This error state of a APDU object occurs when an APDUException with reason code APDUException.NO_T0_GETRESPONSE has been thrown.

See Also:
Constant Field Values

STATE_ERROR_T1_IFD_ABORT

public static final byte STATE_ERROR_T1_IFD_ABORT
This error state of a APDU object occurs when an APDUException with reason code APDUException.T1_IFD_ABORT has been thrown.

See Also:
Constant Field Values

STATE_ERROR_IO

public static final byte STATE_ERROR_IO
This error state of a APDU object occurs when an APDUException with reason code APDUException.IO_ERROR has been thrown

See Also:
Constant Field Values

STATE_ERROR_NO_T0_REISSUE

public static final byte STATE_ERROR_NO_T0_REISSUE
This error state of a APDU object occurs when an APDUException with reason code APDUException.NO_T0_REISSUE has been thrown.

See Also:
Constant Field Values

PROTOCOL_MEDIA_MASK

public static final byte PROTOCOL_MEDIA_MASK
Media nibble mask in protocol byte

See Also:
Constant Field Values

PROTOCOL_TYPE_MASK

public static final byte PROTOCOL_TYPE_MASK
Type nibble mask in protocol byte

See Also:
Constant Field Values

PROTOCOL_T0

public static final byte PROTOCOL_T0
ISO 7816 transport protocol type T=0.

See Also:
Constant Field Values

PROTOCOL_T1

public static final byte PROTOCOL_T1
This constant is used to denote both the ISO 7816 transport protocol type T=1 and the variant for contactless cards defined in ISO 14443-4.

See Also:
Constant Field Values

PROTOCOL_MEDIA_DEFAULT

public static final byte PROTOCOL_MEDIA_DEFAULT
Transport protocol Media - Contacted Asynchronous Half Duplex

See Also:
Constant Field Values

PROTOCOL_MEDIA_CONTACTLESS_TYPE_A

public static final byte PROTOCOL_MEDIA_CONTACTLESS_TYPE_A
Transport protocol Media - Contactless Type A

See Also:
Constant Field Values

PROTOCOL_MEDIA_CONTACTLESS_TYPE_B

public static final byte PROTOCOL_MEDIA_CONTACTLESS_TYPE_B
Transport protocol Media - Contactless Type B

See Also:
Constant Field Values

PROTOCOL_MEDIA_USB

public static final byte PROTOCOL_MEDIA_USB
Transport protocol Media - USB

See Also:
Constant Field Values
Method Detail

getBuffer

public byte[] getBuffer()
Returns the APDU buffer byte array.

Note:

  • References to the APDU buffer byte array cannot be stored in class variables or instance variables or array components. See Runtime Specification for the Java Card Platform, section 6.2.2 for details.

Returns:
byte array containing the APDU buffer

getInBlockSize

public static short getInBlockSize()
Returns the configured incoming block size. In T=1 protocol, this corresponds to IFSC (information field size for ICC), the maximum size of incoming data blocks into the card. In T=0 protocol, this method returns 1. IFSC is defined in ISO 7816-3.

This information may be used to ensure that there is enough space remaining in the APDU buffer when receiveBytes() is invoked.

Note:

  • On receiveBytes() the bOff param should account for this potential blocksize.

Returns:
incoming block size setting
See Also:
APDU.receiveBytes(short)

getOutBlockSize

public static short getOutBlockSize()
Returns the configured outgoing block size. In T=1 protocol, this corresponds to IFSD (information field size for interface device), the maximum size of outgoing data blocks to the CAD. In T=0 protocol, this method returns 258 (accounts for 2 status bytes). IFSD is defined in ISO 7816-3.

This information may be used prior to invoking the setOutgoingLength() method, to limit the length of outgoing messages when BLOCK CHAINING is not allowed.

Note:

  • On setOutgoingLength() the len param should account for this potential blocksize.

Returns:
outgoing block size setting
See Also:
APDU.setOutgoingLength(short)

getProtocol

public static byte getProtocol()
Returns the ISO 7816 transport protocol type, T=1 or T=0 in the low nibble and the transport media in the upper nibble in use.

Returns:
he protocol media and type in progress Valid nibble codes are listed in PROTOCOL_ .. constants above.
See Also:
PROTOCOL_T0

getNAD

public byte getNAD()
Returns the Node Address byte (NAD) in T=1 protocol, and 0 in T=0 protocol. This may be used as additional information to maintain multiple contexts.

Returns:
NAD transport byte as defined in ISO 7816-3

setOutgoing

public short setOutgoing()
                  throws APDUException
This method is used to set the data transfer direction to outbound and to obtain the expected length of response (Le).

Notes.

  • Any remaining incoming data will be discarded.
  • In T=0 (Case 4) protocol, this method will return 256.
  • This method sets the state of the APDU object to STATE_OUTGOING.

Returns:
Le, the expected length of response
Throws:
APDUException - with the following reason codes:
  • APDUException.ILLEGAL_USE if this method, or setOutgoingNoChaining() method already invoked.
  • APDUException.IO_ERROR on I/O error.

setOutgoingNoChaining

public short setOutgoingNoChaining()
                            throws APDUException
This method is used to set the data transfer direction to outbound without using BLOCK CHAINING (See ISO 7816-3/4) and to obtain the expected length of response (Le). This method should be used in place of the setOutgoing() method by applets which need to be compatible with legacy CAD/terminals which do not support ISO 7816-3/4 defined block chaining. See Runtime Specification for the Java Card Platform, section 9.4 for details.

Notes.

  • Any remaining incoming data will be discarded.
  • In T=0 (Case 4) protocol, this method will return 256.
  • When this method is used, the waitExtension() method cannot be used.
  • In T=1 protocol, retransmission on error may be restricted.
  • In T=0 protocol, the outbound transfer must be performed without using (ISO7816.SW_BYTES_REMAINING_00+count) response status chaining.
  • In T=1 protocol, the outbound transfer must not set the More(M) Bit in the PCB of the I block. See ISO 7816-3.
  • This method sets the state of the APDU object to STATE_OUTGOING.

Returns:
Le, the expected length of response data
Throws:
APDUException - with the following reason codes:
  • APDUException.ILLEGAL_USE if this method, or setOutgoing() method already invoked.
  • APDUException.IO_ERROR on I/O error

setOutgoingLength

public void setOutgoingLength(short len)
                       throws APDUException
Sets the actual length of response data. If a length of 0 is specified, no data will be output.

Note:

  • In T=0 (Case 2&4) protocol, the length is used by the Java Card runtime environment to prompt the CAD for GET RESPONSE commands.
  • This method sets the state of the APDU object to STATE_OUTGOING_LENGTH_KNOWN.

Parameters:
len - the length of response data
Throws:
APDUException - with the following reason codes:
  • APDUException.ILLEGAL_USE if setOutgoing() not called or this method already invoked.
  • APDUException.BAD_LENGTH if len is greater than 256 or if non BLOCK CHAINED data transfer is requested and len is greater than (IFSD-2), where IFSD is the Outgoing Block Size. The -2 accounts for the status bytes in T=1. *
  • APDUException.NO_GETRESPONSE if T=0 protocol is in use and the CAD does not respond to (ISO7816.SW_BYTES_REMAINING_00+count) response status with GET RESPONSE command on the same origin logical channel number as that of the current APDU command.
  • APDUException.NO_T0_REISSUE if T=0 protocol is in use and the CAD does not respond to (ISO7816.SW_CORRECT_LENGTH_00+count) response status by re-issuing same APDU command on the same origin logical channel number as that of the current APDU command with the corrected length.
  • APDUException.IO_ERROR on I/O error.
See Also:
APDU.getOutBlockSize()

receiveBytes

public short receiveBytes(short bOff)
                   throws APDUException
Throws:
APDUException

setIncomingAndReceive

public short setIncomingAndReceive()
                            throws APDUException
This is the primary receive method. Calling this method indicates that this APDU has incoming data. This method gets as many bytes as will fit without buffer overflow in the APDU buffer following the header. It gets all the incoming bytes if they fit.

Notes:

  • In T=0 ( Case 3&4 ) protocol, the P3 param is assumed to be Lc.
  • Data is read into the buffer at offset 5.
  • In T=1 protocol, if all the incoming bytes do not fit in the buffer, this method may return less bytes than the maximum incoming block size (IFSC).
  • In T=0 protocol, if all the incoming bytes do not fit in the buffer, this method may return less than a full buffer of bytes to optimize and reduce protocol overhead.
  • This method sets the transfer direction to be inbound and calls receiveBytes(5).
  • This method may only be called once in a Applet.process() method.
  • This method sets the state of the APDU object to STATE_PARTIAL_INCOMING if all incoming bytes are not received.
  • This method sets the state of the APDU object to STATE_FULL_INCOMING if all incoming bytes are received.

Returns:
number of data bytes read. The Le byte, if any, is not included in the count. Returns 0 if no bytes are available.
Throws:
APDUException - with the following reason codes:
  • APDUException.ILLEGAL_USE if setIncomingAndReceive() already invoked or if setOutgoing() or setOutgoingNoChaining() previously invoked.
  • APDUException.IO_ERROR on I/O error.
  • APDUException.T1_IFD_ABORT if T=1 protocol is in use and the CAD sends in an ABORT S-Block command to abort the data transfer.

sendBytes

public void sendBytes(short bOff,
                      short len)
               throws APDUException
Throws:
APDUException

sendBytesLong

public void sendBytesLong(byte[] outData,
                          short bOff,
                          short len)
                   throws APDUException,
                          SecurityException
Sends len more bytes from outData byte array starting at specified offset bOff.

If the last of the response is being sent by the invocation of this method, the APDU buffer must not be altered. If the data is altered, incorrect output may be sent to the CAD. Requiring that the buffer not be altered allows the implementation to reduce protocol overhead by transmitting the last part of the response along with the status bytes.

The Java Card runtime environment may use the APDU buffer to send data to the CAD.

Notes:

  • If setOutgoingNoChaining() was invoked, output block chaining must not be used.
  • In T=0 protocol, if setOutgoingNoChaining() was invoked, Le bytes must be transmitted before (ISO7816.SW_BYTES_REMAINING_00+remaining bytes) response status is returned.
  • In T=0 protocol, if this method throws an APDUException with NO_T0_GETRESPONSE or NO_T0_REISSUE reason code, the Java Card runtime environment will restart APDU command processing using the newly received command. No more output data can be transmitted. No error status response can be returned.
  • In T=1 protocol, if this method throws an APDUException with T1_IFD_ABORT reason code, the Java Card runtime environment will restart APDU command processing using the newly received command. No more output data can be transmitted. No error status response can be returned.
  • This method sets the state of the APDU object to STATE_PARTIAL_OUTGOING if all outgoing bytes have not been sent.
  • This method sets the state of the APDU object to STATE_FULL_OUTGOING if all outgoing bytes have been sent.

Parameters:
outData - the source data byte array
bOff - the offset into OutData array
len - the byte length of the data to send
Throws:
APDUException - with the following reason codes:
  • APDUException.ILLEGAL_USE if setOutgoingLength() not called or setOutgoingAndSend() previously invoked or response byte count exceeded or if APDUException.NO_T0_GETRESPONSE or APDUException.NO_T0_REISSUE or APDUException.NO_T0_REISSUE previously thrown.
  • APDUException.IO_ERROR on I/O error.
  • APDUException.NO_T0_GETRESPONSE if T=0 protocol is in use and CAD does not respond to (ISO7816.SW_BYTES_REMAINING_00+count) response status with GET RESPONSE command on the same origin logical channel number as that of the current APDU command.
  • APDUException.T1_IFD_ABORT if T=1 protocol is in use and the CAD sends in an ABORT S-Block command to abort the data transfer.
SecurityException - if the outData array is not accessible in the caller's context
See Also:
setOutgoing(), setOutgoingNoChaining()

setOutgoingAndSend

public void setOutgoingAndSend(short bOff,
                               short len)
                        throws APDUException
This is the "convenience" send method. It provides for the most efficient way to send a short response which fits in the buffer and needs the least protocol overhead. This method is a combination of setOutgoing(), setOutgoingLength( len ) followed by sendBytes ( bOff, len ). In addition, once this method is invoked, sendBytes() and sendBytesLong() methods cannot be invoked and the APDU buffer must not be altered.

Sends len byte response from the APDU buffer starting at the specified offset bOff.

Notes:

  • No other APDU send methods can be invoked.
  • The APDU buffer must not be altered. If the data is altered, incorrect output may be sent to the CAD.
  • The actual data transmission may only take place on return from Applet.process()
  • This method sets the state of the APDU object to STATE_FULL_OUTGOING.

Parameters:
bOff - the offset into APDU buffer
len - the bytelength of the data to send
Throws:
APDUException - ith the following reason codes:
  • APDUException.ILLEGAL_USE if setOutgoing() or setOutgoingAndSend() previously invoked or response byte count exceeded.
  • APDUException.IO_ERROR on I/O error.

getCurrentState

public byte getCurrentState()
This method returns the current processing state of the APDU object. It is used by the BasicService class to help services collaborate in the processing of an incoming APDU command. Valid codes are listed in STATE_ .. constants above.

Returns:
the current processing state of the APDU
See Also:
STATE_INITIAL

getCurrentAPDU

public static APDU getCurrentAPDU()
                           throws SecurityException
This method is called to obtain a reference to the current APDU object. This method can only be called in the context of the currently selected applet.

Note:

  • Do not call this method directly or indirectly from within a method invoked remotely via Java Card RMI method invocation from the client. The APDU object and APDU buffer are reserved for use by RMIService. Remote method parameter data may become corrupted.

Returns:
the current APDU object being processed
Throws:
SecurityException - if
  • the current context is not the context of the currently selected applet instance or
  • this method was not called, directly or indirectly, from the applet's process method (called directly by the Java Card runtime environment), or
  • the method is called during applet installation or deletion.

getCurrentAPDUBuffer

public static byte[] getCurrentAPDUBuffer()
                                   throws SecurityException
This method is called to obtain a reference to the current APDU buffer. This method can only be called in the context of the currently selected applet.

Note:

  • Do not call this method directly or indirectly from within a method invoked remotely via Java Card RMI method invocation from the client. The APDU object and APDU buffer are reserved for use by RMIService. Remote method parameter data may become corrupted.

Returns:
the APDU buffer of the APDU object being processed
Throws:
SecurityException - if
  • the current context is not the context of the currently selected applet or
  • this method was not called, directly or indirectly, from the applet's process method (called directly by the Java Card runtime environment), or
  • the method is called during applet installation or deletion.

getCLAChannel

public static byte getCLAChannel()
Returns the logical channel number associated with the current APDU command based on the CLA byte. A number in the range 0-3 based on the least significant two bits of the CLA byte is returned if the command contains logical channel encoding. If the command does not contain logical channel information, 0 is returned. See Runtime Specification for the Java Card Platform, section 4.3 for encoding details.

Returns:
logical channel number, if present, within the CLA byte, 0 otherwise

waitExtension

public static void waitExtension()
                          throws APDUException
Requests additional processing time from CAD. The implementation should ensure that this method needs to be invoked only under unusual conditions requiring excessive processing times.

Notes:

  • In T=0 protocol, a NULL procedure byte is sent to reset the work waiting time (see ISO 7816-3).
  • In T=1 protocol, the implementation needs to request the same T=0 protocol work waiting time quantum by sending a T=1 protocol request for wait time extension(see ISO 7816-3).
  • If the implementation uses an automatic timer mechanism instead, this method may do nothing.

Throws:
APDUException - with the following reason codes:
  • APDUException.ILLEGAL_USE if setOutgoingNoChaining() previously invoked.
  • APDUException.IO_ERROR on I/O error.

reset

public void reset()
clear internal state of the APDU