What is Apdu in Java Card?

Application Protocol Data Unit (APDU) is the communication format between the card and the off-card applications. 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.

What is extended Apdu?

The ISO 7816-4:2005 specification defines an extended APDU as any APDU whose payload data, response data or expected data length exceeds the 256 byte limit.

What is CLA in Apdu?

The header specifies what function should be called: 00 – class byte (CLA, 00 means “inter-industry command sent to logical channel 0”) A4 – instruction byte (INS, A4 means “SELECT applet command”) 04 – parameter 1 (P1)

What does Apdu stand for?

In the context of smart cards, an application protocol data unit (APDU) is the communication unit between a smart card reader and a smart card. The structure of the APDU is defined by ISO/IEC 7816-4 Organization, security and commands for interchange.

What is a Java Card applet?

Java Card refers to a software technology that allows Java-based applications (applets) to be run securely on smart cards and similar small memory footprint devices. Java Card gives the user the ability to program the devices and make them application specific. It is widely used in ATM cards.

What are APDU commands?

APDU is a command response protocol for invoking functions executed on a smart card or similar device. In essence, the command consists of a 4 byte header followed by up to 255 bytes of data. The headers and data are specified in a suite of standards from ISO and others.

What is APDU English?

In the context of smart cards, an application protocol data unit (APDU) is the communication unit between a smart card reader and a smart card.

What is Visa and smart card?

A smart card is a physical card that has an embedded integrated chip that acts as a security token. Smart cards are typically the same size as a driver’s license or credit card and can be made out of metal or plastic. The chip on a smart card can be either a microcontroller or an embedded memory chip.

What is APDU timeout?

APDU Timeout Sets the time in milliseconds that the driver will wait for a response from a device after sending a request. As a BACnet server, this setting only applies to Confirmed COV Notifications.

Do SIM cards use Java?

Technical overview of SIM applets Applets are based on Java Card, a limited subset of Java language. The SIM cards operating system (OS) is similarly written in Java Card. The OS is the first and most important SIM Applet. After compiling the code, you will end up with a .

How do Java cards work?

Years ago Sun Microsystems realized the potential of smart cards and similar resource-constrained devices, and defined a set of specifications for a subset of Java technology to create applications for them, Java Card applets. A device that supports these specifications is referred to as a Java Card platform.

What is Apdu English?

Can a smart card accept APDUs in Java?

However, note that not all terminals and Smart Cards are capable of accepting APDUs that use the extended form. For the header bytes CLA, INS, P1, and P2 the Java type int is used to represent the 8 bit unsigned values. In the constructors, only the 8 lowest bits of the int value specified by the application are significant.

Where does the APDU data start in Java?

The APDU starts at the index apduOffset in the byte array and is apduLength bytes long. Note that the apdu bytes are copied to protect against subsequent modification. apduOffset – the offset in the byte array at which the apdu data begins

How big is the APDU buffer in Java?

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.

What’s the difference between JavaCard and APDU format?

To answer your question: JavaCard is just a language for writing smartcard applications called applets. It handles all the application logic, but it does not specify the APDU format. That is because JavaCard is not the only smartcard technology. APDU format is specifed in ISO7816 standard, which I really recommend you to read through.