org.bouncycastle.crypto.macs

Class KMAC

java.lang.Object

org.bouncycastle.crypto.macs.KMAC

All Implemented Interfaces:

Digest, EncodableDigest, EncodableService, ExtendedDigest, Mac, Xof, Memoable

public class KMAC
extends java.lang.Object
implements Mac, Xof, Memoable, EncodableDigest

KMAC - MAC with optional XOF mode.

From NIST Special Publication 800-185 - SHA-3 Derived Functions:cSHAKE, KMAC, TupleHash and ParallelHash

Constructor Summary

Constructors

Constructor and Description
KMAC(byte[] state)
KMAC(int bitLength, byte[] S) Base constructor.
KMAC(KMAC original)

Method Summary

Modifier and Type	Method and Description
Memoable	copy() Produce a copy of this object with its configuration and in its current state.
int	doFinal(byte[] out, int outOff) Compute the final stage of the MAC writing the output to the out parameter.
int	doFinal(byte[] out, int outOff, int outLen) Output the results of the final calculation for this digest to outLen number of bytes.
int	doOutput(byte[] out, int outOff, int outLen) Start outputting the results of the final calculation for this digest.
java.lang.String	getAlgorithmName() Return the name of the algorithm the MAC implements.
int	getByteLength() Return the size in bytes of the internal buffer the digest applies it's compression function to.
int	getDigestSize() return the size, in bytes, of the digest produced by this message digest.
byte[]	getEncodedState() Return an encoded byte array for the digest's internal state
int	getMacSize() Return the block size for this MAC (in bytes).
void	init(CipherParameters params) Initialise the MAC.
void	reset() Reset the MAC.
void	reset(Memoable other) Restore a copied object state into this object.
void	update(byte in) add a single byte to the mac for processing.
void	update(byte[] in, int inOff, int len) update the message digest with a block of bytes.

Methods inherited from class java.lang.Object

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

Constructor Detail

KMAC

public KMAC(int bitLength,
            byte[] S)

Base constructor.

Parameters:

bitLength - bit length of the underlying SHAKE function, 128 or 256.

S - the customization string - available for local use.

KMAC

public KMAC(KMAC original)

KMAC

public KMAC(byte[] state)

Method Detail

init

public void init(CipherParameters params)
          throws java.lang.IllegalArgumentException

Description copied from interface: Mac

Initialise the MAC.

Specified by:

init in interface Mac

Parameters:

params - the key and other data required by the MAC.

Throws:

java.lang.IllegalArgumentException - if the params argument is inappropriate.

getAlgorithmName

public java.lang.String getAlgorithmName()

Description copied from interface: Mac

Return the name of the algorithm the MAC implements.

Specified by:

getAlgorithmName in interface Digest

Specified by:

getAlgorithmName in interface Mac

Returns:

the name of the algorithm the MAC implements.

getByteLength

public int getByteLength()

Description copied from interface: ExtendedDigest

Return the size in bytes of the internal buffer the digest applies it's compression function to.

Specified by:

getByteLength in interface ExtendedDigest

Returns:

byte length of the digests internal buffer.

getMacSize

public int getMacSize()

Description copied from interface: Mac

Return the block size for this MAC (in bytes).

Specified by:

getMacSize in interface Mac

Returns:

the block size for this MAC in bytes.

getDigestSize

public int getDigestSize()

Description copied from interface: Digest

return the size, in bytes, of the digest produced by this message digest.

Specified by:

getDigestSize in interface Digest

Returns:

the size, in bytes, of the digest produced by this message digest.

update

public void update(byte in)
            throws java.lang.IllegalStateException

Description copied from interface: Mac

add a single byte to the mac for processing.

Specified by:

update in interface Digest

Specified by:

update in interface Mac

Parameters:

in - the byte to be processed.

Throws:

java.lang.IllegalStateException - if the MAC is not initialised.

update

public void update(byte[] in,
                   int inOff,
                   int len)
            throws DataLengthException,
                   java.lang.IllegalStateException

Description copied from interface: Digest

update the message digest with a block of bytes.

Specified by:

update in interface Digest

Specified by:

update in interface Mac

Parameters:

in - the array containing the input.

inOff - the index in the array the data begins at.

len - the length of the input starting at inOff.

Throws:

DataLengthException - if there isn't enough data in in.

java.lang.IllegalStateException - if the MAC is not initialised.

doFinal

public int doFinal(byte[] out,
                   int outOff)
            throws DataLengthException,
                   java.lang.IllegalStateException

Description copied from interface: Mac

Compute the final stage of the MAC writing the output to the out parameter.

doFinal leaves the MAC in the same state it was after the last init.

Specified by:

doFinal in interface Digest

Specified by:

doFinal in interface Mac

Parameters:

out - the array the MAC is to be output to.

outOff - the offset into the out buffer the output is to start at.

Throws:

DataLengthException - if there isn't enough space in out.

java.lang.IllegalStateException - if the MAC is not initialised.

doFinal

public int doFinal(byte[] out,
                   int outOff,
                   int outLen)

Description copied from interface: Xof

Output the results of the final calculation for this digest to outLen number of bytes.

Specified by:

doFinal in interface Xof

Parameters:

out - output array to write the output bytes to.

outOff - offset to start writing the bytes at.

outLen - the number of output bytes requested.

Returns:

the number of bytes written

doOutput

public int doOutput(byte[] out,
                    int outOff,
                    int outLen)

Description copied from interface: Xof

Start outputting the results of the final calculation for this digest. Unlike doFinal, this method will continue producing output until the Xof is explicitly reset, or signals otherwise.

Specified by:

doOutput in interface Xof

Parameters:

out - output array to write the output bytes to.

outOff - offset to start writing the bytes at.

outLen - the number of output bytes requested.

Returns:

the number of bytes written

reset

public void reset()

Description copied from interface: Mac

Reset the MAC. At the end of resetting the MAC should be in the in the same state it was after the last init (if there was one).

Specified by:

reset in interface Digest

Specified by:

reset in interface Mac

getEncodedState

public byte[] getEncodedState()

Description copied from interface: EncodableDigest

Return an encoded byte array for the digest's internal state

Specified by:

getEncodedState in interface EncodableDigest

Specified by:

getEncodedState in interface EncodableService

Returns:

an encoding of the digests internal state.

copy

public Memoable copy()

Description copied from interface: Memoable

Produce a copy of this object with its configuration and in its current state.

The returned object may be used simply to store the state, or may be used as a similar object starting from the copied state.

Specified by:

copy in interface Memoable

reset

public void reset(Memoable other)

Description copied from interface: Memoable

Restore a copied object state into this object.

Implementations of this method should try to avoid or minimise memory allocation to perform the reset.

Specified by:

reset in interface Memoable

Parameters:

other - an object originally copied from an object of the same type as this instance.