java.lang.Object
|
+--javacard.framework.Applet
- See Also:
SystemException,
JCSystem
protected Applet()
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
[1442]Javacard Applet for reading data with APDU
By Anonymous on 2005/05/26 12:50:01 Rate
package bank.purse;
import javacard.framework.*;
import javacardx.framework.*;
public class Wallet extends Applet
{
// code of CLA byte in the command APDU header
final static byte Wallet_CLA = ( byte ) 0xB0;
// codes of INS byte in the command APDU header
final static byte VERIFY = ( byte ) 0x20;
final static byte CREDIT = ( byte ) 0x30;
final static byte DEBIT = ( byte ) 0x40;
final static byte GET_BALANCE = ( byte ) 0x50;
// maximum balance
final static short MAX_BALANCE = 0x7FFF;
// maximum transaction amount
final static byte MAX_TRANSACTION_AMOUNT = 127;
// maximum number of incorrect tries before the
// PIN is blocked
final static byte PIN_TRY_LIMIT = ( byte ) 0x03;
// maximum size PIN
final static byte MAX_PIN_SIZE = ( byte ) 0x08;
// signal that the PIN verification failed
final static short SW_VERIFICATION_FAILED = 0x6300;
// signal the PIN validation is required
// for a credit or a debit transaction
final static short SW_PIN_VERIFICATION_REQUIRED =0x6301;
// signal invalid transaction amount
// amount > MAX_TRANSACTION_MAOUNT or amount < 0
final static short SW_INVALID_TRANSACTION_AMOUNT = 0x6A83;
// signal that the balance exceed the maximum
final static short SW_EXCEED_MAXIMUM_BALANCE = 0x6A84;
// signal the balance becomes negative
final static short SW_NEGATIVE_BALANCE = 0x6A85;
OwnerPIN pin;
short balance;
private Wallet ( byte [ ] bArray,
short bOffset, byte bLength )
{
// It is good programming practice to allocate
// all the memory that an applet needs during
// its lifetime inside the constructor
pin = new OwnerPIN ( PIN_TRY_LIMIT, MAX_PIN_SIZE ) ;
// The installation parameters contain the PIN
// initialization
value pin.update ( bArray, bOffset, bLength ) ;
register ( ) ;
}
// end of the constructor
public static void install ( byte [ ] bArray, short bOffset, byte bLength )
{
// create a Wallet applet instance
new Wallet ( bArray, bOffset, bLength ) ;
}
// end of install method
public boolean select ( )
{
// The applet declines to be selected
// if the pin is blocked.
if ( pin.getTriesRemaining ( ) == 0 )
return false;
return true;
}
// end of select method
public void deselect ( )
{
// reset the pin value
pin.reset ( ) ;
}
public void process ( APDU apdu )
{
// APDU object carries a byte array ( buffer ) to
// transfer incoming and outgoing APDU header
// and data bytes between card and CAD
// At this point, only the first header bytes
// [ CLA, INS, P1, P2, P3 ] are available in
// the APDU buffer.
// The interface javacard.framework.ISO7816
// declares constants to denote the offset of
// these bytes in the APDU buffer
byte [ ] buffer = apdu.getBuffer ( ) ;
// check SELECT APDU command
if ( ( buffer [ ISO7816.OFFSET_CLA ] == 0 ) &&
( buffer [ ISO7816.OFFSET_INS ] == ( byte ) ( 0xA4 ) ) )
return;
// verify the reset of commands have the
// correct CLA byte, which specifies the
// command structure
if ( buffer [ ISO7816.OFFSET_CLA ] != Wallet_CLA )
ISOException.throwIt ( ISO7816.SW_CLA_NOT_SUPPORTED ) ;
switch ( buffer [ ISO7816.OFFSET_INS ] )
{
case GET_BALANCE: getBalance ( apdu ) ;
return;
case DEBIT: debit ( apdu ) ;
return;
case CREDIT: credit ( apdu ) ;
return;
case VERIFY: verify ( apdu ) ;
return;
default: ISOException.throwIt
( ISO7816.SW_INS_NOT_SUPPORTED ) ;
}
}
// end of process method
private void credit ( APDU apdu )
{
// access authentication
if ( ! pin.isValidated ( ) )
ISOException.throwIt ( SW_PIN_VERIFICATION_REQUIRED ) ;
byte [ ] buffer = apdu.getBuffer ( ) ;
// Lc byte denotes the number of bytes in the
// data field of the command APDU
byte numBytes = buffer [ ISO7816.OFFSET_LC ] ;
// indicate that this APDU has incoming data
// and receive data starting at the offset
// ISO7816.OFFSET_CDATA following the 5 header
// bytes.
byte byteRead = ( byte ) ( apdu.setIncomingAndReceive ( ) ) ;
// it is an error if the number of data bytes
// read does not match the number in Lc byte
if ( byteRead != 1 ) ISOException.throwIt ( ISO7816.SW_WRONG_LENGTH ) ;
// get the credit amount
byte creditAmount = buffer [ ISO7816.OFFSET_CDATA ] ;
// check the credit amount
if ( ( creditAmount > MAX_TRANSACTION_AMOUNT ) || ( creditAmount < 0 ) )
ISOException.throwIt ( SW_INVALID_TRANSACTION_AMOUNT ) ;
// check the new balance
if ( ( balance + creditAmount ) > MAX_BALANCE )
ISOException.throwIt ( SW_EXCEED_MAXIMUM_BALANCE ) ;
// credit the amount balance = ( short ) ( balance + creditAmount ) ;
}
// end of deposit method
private void debit ( APDU apdu )
{
// access authentication
if ( ! pin.isValidated ( ) )
ISOException.throwIt ( SW_PIN_VERIFICATION_REQUIRED ) ;
byte [ ] buffer = apdu.getBuffer ( ) ;
byte numBytes = ( byte ) ( buffer [ ISO7816.OFFSET_LC ] ) ;
byte byteRead = ( byte ) ( apdu.setIncomingAndReceive ( ) ) ;
if ( byteRead != 1 ) ISOException.throwIt ( ISO7816.SW_WRONG_LENGTH ) ;
// get debit amount
byte debitAmount = buffer [ ISO7816.OFFSET_CDATA ] ;
// check debit amount
if ( ( debitAmount > MAX_TRANSACTION_AMOUNT ) || ( debitAmount < 0 ) )
ISOException.throwIt ( SW_INVALID_TRANSACTION_AMOUNT ) ;
// check the new balance
if ( ( balance-- debitAmount ) < 0 )
ISOException.throwIt ( SW_NEGATIVE_BALANCE ) ;
balance = ( short ) ( balance -- debitAmount ) ;
}
// end of debit method
private void getBalance ( APDU apdu )
{
byte [ ] buffer = apdu.getBuffer ( ) ;
// inform system that the applet has finished
// processing the command and the system should
// now prepare to construct a response APDU
// which contains data field
short le = apdu.setOutgoing ( ) ;
if ( le < 2 ) ISOException.throwItISO7816.SW_WRONG_LENGTH ) ;
//informs the CAD the actual number of bytes
//returned
apdu.setOutgoingLength ( ( byte ) 2 ) ;
// move the balance data into the APDU buffer
// starting at the offset 0
buffer [ 0 ] = ( byte ) ( balance > > 8 ) ;
buffer [ 1 ] = ( byte ) ( balance & 0xFF ) ;
// send the 2-balance byte at the offset
// 0 in the apdu buffer
apdu.sendBytes ( ( short ) 0, ( short ) 2 ) ;
}
// end of getBalance method
private void verify ( APDU apdu )
{
byte [ ] buffer = apdu.getBuffer ( ) ;
// retrieve the PIN data for validation.
byte byteRead = ( byte ) ( apdu.setIncomingAndReceive ( ) ) ;
// check pin
// the PIN data is read into the APDU buffer
// at the offset ISO7816.OFFSET_CDATA
// the PIN data length = byteRead
if ( pin.check ( buffer, ISO7816.OFFSET_CDATA,byteRead ) == false )
ISOException.throwIt ( SW_VERIFICATION_FAILED ) ;
}
// end of validate method }
// end of class Wallet
public void deselect()
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public Shareable getShareableInterfaceObject(AID clientAID,
byte parameter)- See Also:
JCSystem.getAppletShareableInterfaceObject(AID, byte)
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public static void install(byte[] bArray,
short bOffset,
byte bLength)
throws ISOException- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
public abstract void process(APDU apdu)
throws ISOException- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
protected final void register()
throws SystemException- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
protected final void register(byte[] bArray,
short bOffset,
byte bLength)
throws SystemException- See Also:
install(byte[],short,byte)
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- Description Add your codes or notes Search More Java Examples
public boolean select()
- Geek's Notes:
- Description Add your codes or notes Search More Java Examples
protected final boolean selectingApplet()
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Java API By Example, From Geeks To Geeks.