javacardx.apdu.util

Class APDUUtil

java.lang.Object

javacardx.apdu.util.APDUUtil

public class APDUUtil
extends Object

The APDUUtil class contains utility methods to parse CLA byte from a command APDU. All methods in APDUUtil, class are static methods.

Since:

3.0.5

See Also:

APDU

Method Summary

Methods

Modifier and Type	Method and Description
static byte	getCLAChannel(byte CLAbyte) Returns the logical channel number encoded in the CLAbyte parameter which represents a CLA byte from a command APDU.
static boolean	isCommandChainingCLA(byte CLAbyte) Based on encoding of the CLAByte parameter which represents a CLA byte from a command APDU, returns whether an APDU command is the first or part of a command chain.
static boolean	isISOInterindustryCLA(byte CLAbyte) Returns whether the CLAByte parameter which represents a CLA bye from a command APDU, corresponds to an interindustry command as defined in ISO 7816-4:2013 specification.
static boolean	isSecureMessagingCLA(byte CLAbyte) Returns true if encoding of the CLAbyte parameter, which represents a CLA byte from a command APDU, indicates secure messaging.
static boolean	isValidCLA(byte CLAbyte) Returns whether the current CLAByte parameter represents a valid CLA byte.

Methods inherited from class java.lang.Object

equals

Method Detail

getCLAChannel

public static byte getCLAChannel(byte CLAbyte)

Returns the logical channel number encoded in the CLAbyte parameter which represents a CLA byte from a command APDU. A number in the range 0-19 based on the CLA byte encoding is returned if the CLA contains logical channel encoding. If the CLA byte does not contain logical channel information, 0 is returned.

Note:

• This method returns 0 if the CLA bits (b8,b7,b6) is %b001 which is a CLA encoding reserved for future use(RFU), or if CLA is 0xFF which is an invalid value as defined in the ISO 7816-4:2013 specification.

See Runtime Environment Specification, Java Card Platform, Classic Edition, section 4.3 for encoding details.

Parameters:

CLAbyte - is CLA byte from a command APDU

Returns:

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

Since:

3.0.5

See Also:

javacard.framework.APDU.#getCLAChannel()

isSecureMessagingCLA

public static boolean isSecureMessagingCLA(byte CLAbyte)

Returns true if encoding of the CLAbyte parameter, which represents a CLA byte from a command APDU, indicates secure messaging. The secure messaging information is in bits (b4,b3) for commands with origin channel numbers 0-3, and in bit b6 for origin channel numbers 4-19.

Note:

• This method returns false if the CLA bits (b8,b7,b6) is %b001 which is a CLA encoding reserved for future use(RFU), or if CLA is 0xFF which is an invalid value as defined in the ISO 7816-4:2013 specification.

See Runtime Environment Specification, Java Card Platform, Classic Edition, section 4.3 for encoding details.

Parameters:

CLAbyte - is CLA byte from a command APDU

Returns:

true if the secure messaging bit(s) is(are) nonzero, false otherwise

Since:

3.0.5

See Also:

javacard.framework.APDU.#isSecureMessagingCLA()

isCommandChainingCLA

public static boolean isCommandChainingCLA(byte CLAbyte)

Based on encoding of the CLAByte parameter which represents a CLA byte from a command APDU, returns whether an APDU command is the first or part of a command chain. Bit b5 of the CLA byte if set, indicates that the APDU is the first or part of a chain of commands.

Note:

• This method returns false if the CLA bits (b8,b7,b6) is %b001 which is a CLA encoding reserved for future use(RFU), or if CLA is 0xFF which is an invalid value as defined in the ISO 7816-4:2013 specification.

See Runtime Environment Specification, Java Card Platform, Classic Edition, section 4.3 for encoding details.

Parameters:

CLAbyte - is CLA byte from a command APDU

Returns:

true if the CLA byte encoding indicates if an APDU is not the last APDU of a command chain, false otherwise.

Since:

3.0.5

See Also:

javacard.framework.APDU.#isCommandChainingCLA()

isISOInterindustryCLA

public static boolean isISOInterindustryCLA(byte CLAbyte)

Returns whether the CLAByte parameter which represents a CLA bye from a command APDU, corresponds to an interindustry command as defined in ISO 7816-4:2013 specification. Bit b8 of the CLA byte if 0, indicates that the APDU is an interindustry command.

Parameters:

CLAbyte - is CLA byte from a command APDU

Returns:

true if this APDU CLA byte corresponds to an ISO interindustry command, false otherwise.

Since:

3.0.5

See Also:

javacard.framework.APDU.#isISOInterindustryCLA()

isValidCLA

public static boolean isValidCLA(byte CLAbyte)

Returns whether the current CLAByte parameter represents a valid CLA byte. The CLA byte is invalid if the CLA bits (b8,b7,b6) is %b001, which is a CLA encoding reserved for future use(RFU), or if CLA is 0xFF which is an invalid value as defined in the ISO 7816-4:2013 specification.

See Runtime Environment Specification, Java Card Platform, Classic Edition, section 4.3 for encoding details.

Parameters:

CLAbyte - is CLA byte from a command APDU

Returns:

true if CLA byte is valid, false otherwise.

Since:

3.0.5

See Also:

javacard.framework.APDU.#isValidCLA()