org.jitsi.bccontrib.digests

Class Skein

java.lang.Object

org.jitsi.bccontrib.digests.Skein

All Implemented Interfaces:

org.bouncycastle.crypto.Digest, org.bouncycastle.crypto.ExtendedDigest

public class Skein
extends Object
implements org.bouncycastle.crypto.ExtendedDigest

Field Summary

Fields

Modifier and Type	Field and Description
static int	CHAINED_CONFIG
static int	CHAINED_STATE
static int	NORMAL
org.jitsi.bccontrib.digests.Skein.UbiTweak	ubiParameters
static int	ZEROED_STATE

Constructor Summary

Constructors

Constructor and Description
Skein(int stateSize, int outputSize) Initializes the Skein hash instance.
Skein(int stateSize, int outputSize, long treeInfo, byte[] key) Initializes the Skein hash instance for use with a key (Skein MAC)

Method Summary

Modifier and Type	Method and Description
byte[]	doFinal()
int	doFinal(byte[] out, int outOff)
String	getAlgorithmName()
int	getByteLength()
int	getcipherStateBits() The state size of this Skein instance.
int	getDigestSize()
int	getHashSize() The output hash size in bits of this Skein instance
long[]	getState() Get the current internal state of this Skein instance.
int	getStateSize()
void	initialize(long[] externalState) Initialize with state variables provided by application.
void	reset()
void	update(byte in)
void	update(byte[] array, int start, int length)
void	updateBits(byte[] array, int start, int length) Update the hash with a message bit string.

Methods inherited from class java.lang.Object

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

Field Detail

NORMAL

public static final int NORMAL

See Also:

Constant Field Values

ZEROED_STATE

public static final int ZEROED_STATE

See Also:

Constant Field Values

CHAINED_STATE

public static final int CHAINED_STATE

See Also:

Constant Field Values

CHAINED_CONFIG

public static final int CHAINED_CONFIG

See Also:

Constant Field Values

ubiParameters

public org.jitsi.bccontrib.digests.Skein.UbiTweak ubiParameters

Constructor Detail

Skein

public Skein(int stateSize,
             int outputSize)
      throws IllegalArgumentException

Initializes the Skein hash instance.

Parameters:

stateSize - The internal state size of the hash in bits. Supported values are 256, 512, and 1024

outputSize - The output size of the hash in bits. Output size must greater than zero.

Throws:

IllegalArgumentException

Skein

public Skein(int stateSize,
             int outputSize,
             long treeInfo,
             byte[] key)
      throws IllegalArgumentException

Initializes the Skein hash instance for use with a key (Skein MAC)

Parameters:

stateSize - The internal state size of the hash in bits. Supported values are 256, 512, and 1024

outputSize - The output size of the hash in bits. Output size must greater than zero.

treeInfo - Not yet supported.

key - The key for a message authenication code (MAC)

Throws:

IllegalArgumentException

Method Detail

getStateSize

public int getStateSize()

updateBits

public void updateBits(byte[] array,
                       int start,
                       int length)
                throws IllegalStateException

Update the hash with a message bit string. Skein can handle data not only as bytes but also as bit strings of arbitrary length (up to its maximum design size).

Parameters:

array - The byte array that holds the bit string. The array must be big enough to hold all bits.

start - Offset into byte array where the data starts, must be a byte number (not a bit number).

length - Number of bits to hash.

Throws:

IllegalStateException

update

public void update(byte[] array,
                   int start,
                   int length)

Specified by:

update in interface org.bouncycastle.crypto.Digest

doFinal

public byte[] doFinal()

initialize

public final void initialize(long[] externalState)

Initialize with state variables provided by application. Applications may use this method if they provide thier own Skein state before starting the Skein processing. The number of long (words) of the external state must conform the to number of state variables this Skein instance requires (state size bits / 64). After copying the external state to Skein the functions enables hash processing, thus an application can call update. The Skein MAC implementation uses this function to restore the state for a given state size, key, and output size combination.

Parameters:

externalState - The state to use.

getcipherStateBits

public int getcipherStateBits()

The state size of this Skein instance.

Returns:

the cipherStateBits

getHashSize

public int getHashSize()

The output hash size in bits of this Skein instance

Returns:

the hashSize int bits

getAlgorithmName

public String getAlgorithmName()

Specified by:

getAlgorithmName in interface org.bouncycastle.crypto.Digest

getDigestSize

public int getDigestSize()

Specified by:

getDigestSize in interface org.bouncycastle.crypto.Digest

update

public void update(byte in)

Specified by:

update in interface org.bouncycastle.crypto.Digest

doFinal

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

Specified by:

doFinal in interface org.bouncycastle.crypto.Digest

reset

public void reset()

Specified by:

reset in interface org.bouncycastle.crypto.Digest

getByteLength

public int getByteLength()

Specified by:

getByteLength in interface org.bouncycastle.crypto.ExtendedDigest

getState

public long[] getState()

Get the current internal state of this Skein instance. An application can get the internal state, for example after some key or state-chaining processing, and reuse this state.

Returns:

The current internal state.

See Also:

initialize(long[] externalState)