Package org.webpki.cbor

Class CBORDecoder

java.lang.Object

org.webpki.cbor.CBORDecoder

public class CBORDecoder
extends Object

CBOR decoder class.

Field Summary

Fields

Modifier and Type	Field	Description
static final int	LENIENT_MAP_DECODING
static final int	LENIENT_NUMBER_DECODING
static final int	REJECT_INVALID_FLOATS
static final int	SEQUENCE_MODE

Constructor Summary

Constructors

Constructor	Description
CBORDecoder(InputStream inputStream, int options, int maxInputLength)	Create a customized CBOR decoder.

Method Summary

Modifier and Type	Method	Description
static CBORObject	decode(byte[] cbor)	Decode CBOR data.
CBORObject	decodeWithOptions()	Decode CBOR data with options.
int	getByteCount()	Get CBOR decoder byte count.

Methods inherited from class java.lang.Object

clone, equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

SEQUENCE_MODE

public static final int SEQUENCE_MODE

See Also:

• Constant Field Values

LENIENT_MAP_DECODING

public static final int LENIENT_MAP_DECODING

See Also:

• Constant Field Values

LENIENT_NUMBER_DECODING

public static final int LENIENT_NUMBER_DECODING

See Also:

• Constant Field Values

REJECT_INVALID_FLOATS

public static final int REJECT_INVALID_FLOATS

See Also:

• Constant Field Values

Constructor Details

CBORDecoder

public CBORDecoder(InputStream inputStream,
 int options,
 int maxInputLength)

Create a customized CBOR decoder.

This constructor presumes that the actual decoding is performed by one or more (for sequences only) calls to decodeWithOptions().

Customization is provided through an options parameter. Multiple options can be combined using the binary OR-operator ("|"). A zero (0) sets the decoder default mode. The options are defined by the following constants:

SEQUENCE_MODE:

If the SEQUENCE_MODE option is defined, the following apply:

• The decoder returns after having decoded a single CBOR object, while preparing for the next object.
• If no data is found (EOF), null is returned (empty sequences are permitted).

Note that data that has not yet been decoded, is not verified for correctness.

LENIENT_MAP_DECODING:

By default, the decoder requires that CBOR maps conform to the Deterministic Encoding rules. The LENIENT_MAP_DECODING option forces the decoder to accept CBOR maps with arbitrary key ordering. Note that duplicate keys still cause a CBORException to be thrown.

LENIENT_NUMBER_DECODING:

By default, the decoder requires that CBOR numbers conform to the Deterministic Encoding rules. The LENIENT_NUMBER_DECODING option forces the decoder to accept different representations of CBOR int, bigint, and float items, only limited by RFC 8949.

REJECT_INVALID_FLOATS:

By default, the decoder supports NaN and Infinity values. In case these variants are not applicable for the application in question, the REJECT_INVALID_FLOATS option causes such numbers to throw a CBORException.

Exceeding maxInputLength throws a CBORException. It is recommendable setting this as low as possible, since malformed CBOR objects may request any amount of memory.

Parameters:

inputStream - Stream holding CBOR data.

options - The decoder options.

maxInputLength - Upper limit in bytes.

See Also:

• getByteCount()

Method Details

decodeWithOptions

public CBORObject decodeWithOptions()

Decode CBOR data with options.

Returns:

CBORObject or null (for EOF sequences only).

Throws:

CBORException - For decoding errors.

getByteCount

public int getByteCount()

Get CBOR decoder byte count.

This is equivalent to the position of the next item to be read.

Returns:

The number of bytes read so far.

decode

public static CBORObject decode(byte[] cbor)

Decode CBOR data.

This conveniance method is identical to:

  new CBORDecoder(new ByteArrayInputStream(cbor), 0, cbor.length)
      .decodeWithOptions();
 

Parameters:

cbor - CBOR binary data holding exactly one CBOR object.

Returns:

CBORObject

Throws:

CBORException - For decoding errors.