Class HMac

java.lang.Object

org.gudy.bouncycastle.crypto.macs.HMac

All Implemented Interfaces:

Mac

public class HMac
extends Object
implements Mac

HMAC implementation based on RFC2104 H(K XOR opad, H(K XOR ipad, text))

Field Summary

Fields

Modifier and Type	Field	Description
private static final int	BLOCK_LENGTH
private Digest	digest
private int	digestSize
private byte[]	inputPad
private static final byte	IPAD
private static final byte	OPAD
private byte[]	outputPad

Constructor Summary

Constructors

Constructor	Description
HMac(Digest digest)

Method Summary

Modifier and Type	Method	Description
int	doFinal(byte[] out, int outOff)	Compute the final statge of the MAC writing the output to the out parameter.
String	getAlgorithmName()	Return the name of the algorithm the MAC implements.
int	getMacSize()	Return the block size for this cipher (in bytes).
Digest	getUnderlyingDigest()
void	init(CipherParameters params)	Initialise the MAC.
void	reset()	Reset the mac generator.
void	update(byte in)	add a single byte to the mac for processing.
void	update(byte[] in, int inOff, int len)

Methods inherited from class Object

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

Field Details

BLOCK_LENGTH

private static final int BLOCK_LENGTH

See Also:

• Constant Field Values

IPAD

private static final byte IPAD

See Also:

• Constant Field Values

OPAD

private static final byte OPAD

See Also:

• Constant Field Values

digest

private Digest digest

digestSize

private int digestSize

inputPad

private byte[] inputPad

outputPad

private byte[] outputPad

Constructor Details

HMac

public HMac(Digest digest)

Method Details

getAlgorithmName

public String getAlgorithmName()

Description copied from interface: Mac

Return the name of the algorithm the MAC implements.

Specified by:

getAlgorithmName in interface Mac

Returns:

the name of the algorithm the MAC implements.

getUnderlyingDigest

public Digest getUnderlyingDigest()

init

public void init(CipherParameters params)

Description copied from interface: Mac

Initialise the MAC.

Specified by:

init in interface Mac

getMacSize

public int getMacSize()

Description copied from interface: Mac

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

Specified by:

getMacSize in interface Mac

Returns:

the block size for this cipher in bytes.

update

public void update(byte in)

Description copied from interface: Mac

add a single byte to the mac for processing.

Specified by:

update in interface Mac

Parameters:

in - the byte to be processed.

update

public void update(byte[] in,
 int inOff,
 int len)

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.

doFinal

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

Description copied from interface: Mac

Compute the final statge 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 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.

reset

public void reset()

Reset the mac generator.

Specified by:

reset in interface Mac