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:

  • Method Summary

    Modifier and Type
    Method
    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 encoded according to 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 Object

    equals
    Modifier and Type
    Method
    Description
    boolean
    equals(Object obj)
    Compares two Objects for equality.

  • Method Details

    • 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 encoded according to APDU. LC_ENCODING_TYPE_4_TYPE _16. 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:

    • 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:

    • 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:

    • 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:

    • 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: