javacardx.framework.tlv

Class BERTag

java.lang.Object

javacardx.framework.tlv.BERTag

Direct Known Subclasses:

ConstructedBERTag, PrimitiveBERTag

public abstract class BERTag
extends Object

The abstract BERTag class encapsulates a BER TLV tag. The rules on the allowed encoding of the Tag field are based on the ASN.1 BER encoding rules of ISO/IEC 8825-1:2002.

The BERTag class and the subclasses ConstructedBERTag and PrimitiveBERTag, also provide static methods to parse or edit a BER Tag structure representation in a byte array.

Since:

2.2.2

Field Summary

Fields

Modifier and Type	Field and Description
static byte	BER_TAG_CLASS_MASK_APPLICATION Constant for BER Tag Class Application
static byte	BER_TAG_CLASS_MASK_CONTEXT_SPECIFIC Constant for BER Tag Class Context-Specific
static byte	BER_TAG_CLASS_MASK_PRIVATE Constant for BER Tag Class Private
static byte	BER_TAG_CLASS_MASK_UNIVERSAL Constant for BER Tag Class Universal
static boolean	BER_TAG_TYPE_CONSTRUCTED Constant for constructed BER Tag type
static boolean	BER_TAG_TYPE_PRIMITIVE Constant for primitive BER Tag type

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	BERTag() Constructor creates an empty BERTLV Tag object capable of encapsulating a BER TLV Tag.

Method Summary

Methods

Modifier and Type	Method and Description
boolean	equals(BERTag otherTag) Compares this BER Tag with another.
boolean	equals(Object otherTag) Compares two Objects for equality.
static BERTag	getInstance(byte[] bArray, short bOff) Create a BERTLV Tag object from the binary representation in the byte array.
abstract void	init(byte[] bArray, short bOff) Abstract init method.
boolean	isConstructed() Used to query if this BER tag structure is constructed
static boolean	isConstructed(byte[] berTagArray, short bOff) Returns the constructed flag part of the BER Tag from its representation in the specified byte array
byte	size() Returns the byte size required to represent this tag structure
static byte	size(byte[] berTagArray, short bOff) Returns the byte size required to represent the BER Tag from its representation in the specified byte array
byte	tagClass() Returns the tag class part of this BER Tag structure
static byte	tagClass(byte[] berTagArray, short bOff) Returns the tag class part of the BER Tag from its representation in the specified byte array
short	tagNumber() Returns the tag number part of this BER Tag structure
static short	tagNumber(byte[] berTagArray, short bOff) Returns the tag number part of the BER Tag from its representation in the specified byte array
short	toBytes(byte[] outBuf, short bOffset) Writes the representation of this BER tag structure to the byte array
static short	toBytes(short tagClass, boolean isConstructed, short tagNumber, byte[] outArray, short bOff) Writes the BER Tag bytes representing the specified tag class, constructed flag and the tag number as a BER Tag representation in the specified byte array
static boolean	verifyFormat(byte[] berTagArray, short bOff) Checks if the input data is a well-formed BER Tag representation

Field Detail

BER_TAG_CLASS_MASK_UNIVERSAL

public static final byte BER_TAG_CLASS_MASK_UNIVERSAL

Constant for BER Tag Class Universal

See Also:

Constant Field Values

BER_TAG_CLASS_MASK_APPLICATION

public static final byte BER_TAG_CLASS_MASK_APPLICATION

Constant for BER Tag Class Application

See Also:

Constant Field Values

BER_TAG_CLASS_MASK_CONTEXT_SPECIFIC

public static final byte BER_TAG_CLASS_MASK_CONTEXT_SPECIFIC

Constant for BER Tag Class Context-Specific

See Also:

Constant Field Values

BER_TAG_CLASS_MASK_PRIVATE

public static final byte BER_TAG_CLASS_MASK_PRIVATE

Constant for BER Tag Class Private

See Also:

Constant Field Values

BER_TAG_TYPE_CONSTRUCTED

public static final boolean BER_TAG_TYPE_CONSTRUCTED

Constant for constructed BER Tag type

See Also:

Constant Field Values

BER_TAG_TYPE_PRIMITIVE

public static final boolean BER_TAG_TYPE_PRIMITIVE

Constant for primitive BER Tag type

See Also:

Constant Field Values

Constructor Detail

BERTag

protected BERTag()

Constructor creates an empty BERTLV Tag object capable of encapsulating a BER TLV Tag. All implementations must support at least 3 byte Tags which can encode tag numbers up to 0x3FFF.

Method Detail

init

public abstract void init(byte[] bArray,
        short bOff)
                   throws TLVException

Abstract init method. (Re-)Initialize this BERTag object from the binary representation in the byte array. All implementations must support tag numbers up to 0x3FFF.

Parameters:

bArray - the byte array containing the binary representation

bOff - the offset within bArray where the tag binary begins

Throws:

ArrayIndexOutOfBoundsException - if accessing the input array would cause access of data outside array bounds, or if the array offset parameter is negative

NullPointerException - if bArray is null

TLVException - with the following reason codes:

• TLVException.ILLEGAL_SIZE if the tag number requested is larger than the supported maximum size
• TLVException.MALFORMED_TAG if tag representation in the byte array is malformed

getInstance

public static BERTag getInstance(byte[] bArray,
                 short bOff)
                          throws TLVException

Create a BERTLV Tag object from the binary representation in the byte array. All implementations must support tag numbers up to 0x3FFF. Note that the returned BERTag must be cast to the correct subclass: PrimitiveBERTag or ConstructedBERTag to access their specialized API.

Parameters:

bArray - the byte array containing the binary representation

bOff - the offset within bArray where the tag binary begins

Throws:

ArrayIndexOutOfBoundsException - if accessing the input array would cause access of data outside array bounds, or if the array offset parameter is negative

NullPointerException - if bArray is null

TLVException - with the following reason codes:

• TLVException.ILLEGAL_SIZE if the tag number requested is larger than the supported maximum size
• TLVException.MALFORMED_TAG if tag representation in the byte array is malformed.

size

public byte size()
          throws TLVException

Returns the byte size required to represent this tag structure

Returns:

size of BER Tag in bytes

Throws:

TLVException - with the following reason codes:

• TLVException.TAG_SIZE_GREATER_THAN_127 if the size of the BER Tag is > 127.
• TLVException.EMPTY_TAG if the BER Tag is empty.

toBytes

public short toBytes(byte[] outBuf,
            short bOffset)
              throws TLVException

Writes the representation of this BER tag structure to the byte array

Parameters:

outBuf - the byteArray where the BER tag is written

bOffset - offset within outBuf where BER tag value starts

Returns:

size of BER Tag in bytes

Throws:

ArrayIndexOutOfBoundsException - if accessing the output array would cause access of data outside array bounds, or if the array offset parameter is negative

NullPointerException - if outBuf is null

TLVException - with the following reason codes:

• TLVException.EMPTY_TAG if the BER Tag is empty.

tagNumber

public short tagNumber()
                throws TLVException

Returns the tag number part of this BER Tag structure

Returns:

the BER Tag tag number

Throws:

TLVException - with the following reason codes:

• TLVException.TAG_NUMBER_GREATER_THAN_32767 if the tag number is > 32767.
• TLVException.EMPTY_TAG if the BER Tag is empty.

isConstructed

public boolean isConstructed()

Used to query if this BER tag structure is constructed

Returns:

true if constructed, false if primitive

Throws:

TLVException - with the following reason codes:

• TLVException.EMPTY_TAG if the BER Tag is empty.

tagClass

public byte tagClass()

Returns the tag class part of this BER Tag structure

Returns:

the BER Tag class. One of the BER_TAG_CLASS_MASK_*.. constants defined above, for example BER_TAG_CLASS_MASK_APPLICATION.

Throws:

TLVException - with the following reason codes:

• TLVException.EMPTY_TAG if the BER Tag is empty.

equals

public boolean equals(BERTag otherTag)

Compares this BER Tag with another. Note that this method does not throw exceptions. If the parameter otherTag is null, the method returns false

Returns:

true if the tag data encapsulated are equal, false otherwise

equals

public boolean equals(Object otherTag)

Description copied from class: Object

Compares two Objects for equality.

The equals method implements an equivalence relation:

• It is reflexive: for any reference value x, x.equals(x) should return true.
• It is symmetric: for any reference values x and y, x.equals(y) should return true if and only if y.equals(x) returns true.
• It is transitive: for any reference values x, y, and z, if x.equals(y) returns true and y.equals(z) returns true, then x.equals(z) should return true.
• It is consistent: for any reference values x and y, multiple invocations of x.equals(y) consistently return true or consistently return false.
• For any reference value x, x.equals(null) should return false.

The equals method for class Object implements the most discriminating possible equivalence relation on objects; that is, for any reference values x and y, this method returns true if and only if x and y refer to the same object (x==y has the value true).

Overrides:

equals in class Object

Parameters:

otherTag - the reference object with which to compare.

Returns:

true if this object is the same as the obj argument; false otherwise.

toBytes

public static short toBytes(short tagClass,
            boolean isConstructed,
            short tagNumber,
            byte[] outArray,
            short bOff)

Writes the BER Tag bytes representing the specified tag class, constructed flag and the tag number as a BER Tag representation in the specified byte array

Parameters:

tagClass - encodes the tag class. Valid codes are the BER_TAG_CLASS_MASK_* constants defined above, for example BER_TAG_CLASS_MASK_APPLICATION.

isConstructed - true if the tag is constructed, false if primitive

tagNumber - is the tag number.

outArray - output byte array

bOff - offset within byte array containing first byte

Returns:

size of BER Tag output bytes

Throws:

ArrayIndexOutOfBoundsException - if accessing the output array would cause access of data outside array bounds, or if the array offset parameter is negative

NullPointerException - if outArray is null

TLVException - with the following reason codes:

• TLVException.ILLEGAL_SIZE if the tag size is larger than the supported maximum size or 32767
• TLVException.INVALID_PARAM if tagClass parameter is invalid or if the tagNumber parameter is negative

size

public static byte size(byte[] berTagArray,
        short bOff)
                 throws TLVException

Returns the byte size required to represent the BER Tag from its representation in the specified byte array

Parameters:

berTagArray - input byte array containing the BER Tag representation

bOff - offset within byte array containing first byte

Returns:

size of BER Tag in bytes

Throws:

ArrayIndexOutOfBoundsException - if accessing the input array would cause access of data outside array bounds, or if the array offset parameter is negative

NullPointerException - if berTagArray is null

TLVException - with the following reason codes:

• TLVException.ILLEGAL_SIZE if the size of the BER Tag is greater than the maximum Tag size supported
• TLVException.TAG_SIZE_GREATER_THAN_127 if the size of the BER Tag is > 127.
• TLVException.MALFORMED_TAG if tag representation in the byte array is malformed

tagNumber

public static short tagNumber(byte[] berTagArray,
              short bOff)
                       throws TLVException

Returns the tag number part of the BER Tag from its representation in the specified byte array

Parameters:

berTagArray - input byte array

bOff - offset within byte array containing first byte

Returns:

the BER Tag tag number

Throws:

ArrayIndexOutOfBoundsException - if accessing the input array would cause access of data outside array bounds, or if the array offset parameter is negative

NullPointerException - if berTagArray is null

TLVException - with the following reason codes:

• TLVException.ILLEGAL_SIZE if the size of the BER Tag is greater than the maximum Tag size supported
• TLVException.TAG_NUMBER_GREATER_THAN_32767 if the tag number is > 32767.
• TLVException.MALFORMED_TAG if tag representation in the byte array is malformed.

isConstructed

public static boolean isConstructed(byte[] berTagArray,
                    short bOff)

Returns the constructed flag part of the BER Tag from its representation in the specified byte array

Parameters:

berTagArray - input byte array

bOff - offset within byte array containing first byte

Returns:

true if constructed, false if primitive

Throws:

ArrayIndexOutOfBoundsException - if accessing the input array would cause access of data outside array bounds, or if the array offset parameter is negative

NullPointerException - if berTagArray is null

TLVException - with the following reason codes:

• TLVException.MALFORMED_TAG if tag representation in the byte array is malformed.

tagClass

public static byte tagClass(byte[] berTagArray,
            short bOff)

Returns the tag class part of the BER Tag from its representation in the specified byte array

Parameters:

berTagArray - input byte array

bOff - offset within byte array containing first byte

Returns:

the BER Tag class. One of the BER_TAG_CLASS_MASK_*.. constants defined above, for example BER_TAG_CLASS_MASK_APPLICATION.

Throws:

ArrayIndexOutOfBoundsException - if accessing the input array would cause access of data outside array bounds, or if the array offset parameter is negative

NullPointerException - if berTagArray is null

TLVException - with the following reason codes:

• TLVException.MALFORMED_TAG if tag representation in the byte array is malformed.

verifyFormat

public static boolean verifyFormat(byte[] berTagArray,
                   short bOff)

Checks if the input data is a well-formed BER Tag representation

Parameters:

berTagArray - input byte array

bOff - offset within byte array containing first byte

Returns:

true if input data is a well formed BER Tag structure of tag size equal to or less than the supported maximum size, false otherwise

Throws:

ArrayIndexOutOfBoundsException - if accessing the input array would cause access of data outside array bounds, or if the array offset parameter is negative

NullPointerException - if berTagArray is null