Applications & SmartCard : JavaCard - Identification - LIFL

JavaCard.Framework.APDU
• Encapsulates 7816-4 APDU elements in pre-created I/O
JavaCard.Framework.APDU
• APDU buffer is handled by the JCRE as a global array
buffer
• APDU = communication packet between on-card and
off-card applications
Incoming APDU
ISO standards
APDU Buffer
CLA INS P1 P2 P3
• Contains methods for sending and receiving data
• Hides the low level details of the protocol used
• APDU objects are owned by the JCRE
• To have a reference on the APDU buffer in the applet
getBuffer()
Return the APDU buffer byte array, filled with APDU
header
http://www.lifl.fr/~grimaud/Cours
JavaCard System & Framework 21
http://www.lifl.fr/~grimaud/Cours
JavaCard System & Framework 22
JavaCard.Framework.APDU
• process() method is called
• getBuffer()
• INS is examined
CLA INS P1 P2 L
Process( )
INS = V1
INS = Vx
INS =V2
Method1( )
Methodx( )
Method2( )
JavaCard.Framework.APDU
Buffer
• To retrieve incoming data (for ISO cases 2 and 4)
setIncomingAndReceive()
Sets the transfer direction to inbound
Receives the incoming data in the APDU buffer at offset = 4
byte bLength = (byte)_apdu.setIncomingAndReceive();
byte bData = baBuffer[ISO7816.OFFSET_CDATA];
OR
receiveBytes(short offset)
Sets the transfer direction to inbound
Receives the incoming data in the APDU buffer at user offset
http://www.lifl.fr/~grimaud/Cours
JavaCard System & Framework 23
http://www.lifl.fr/~grimaud/Cours
JavaCard System & Framework 24