org.gudy.bouncycastle.crypto
Interface Mac

All Known Implementing Classes:

HMac

public interface Mac

The base interface for implementations of message authentication codes (MACs).

Method Summary

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).
void	init(CipherParameters params) Initialise the MAC.
void	reset() Reset the MAC.
void	update(byte in) add a single byte to the mac for processing.
void	update(byte[] in, int inOff, int len)

Method Detail

init

void init(CipherParameters params)
          throws IllegalArgumentException

Initialise the MAC.

Parameters:

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

Throws:

IllegalArgumentException - if the params argument is inappropriate.

getAlgorithmName

String getAlgorithmName()

Return the name of the algorithm the MAC implements.

Returns:

the name of the algorithm the MAC implements.

getMacSize

int getMacSize()

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

Returns:

the block size for this cipher in bytes.

update

void update(byte in)
            throws IllegalStateException

add a single byte to the mac for processing.

Parameters:

in - the byte to be processed.

Throws:

IllegalStateException - if the MAC is not initialised.

update

void update(byte[] in,
            int inOff,
            int len)
            throws DataLengthException,
                   IllegalStateException

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:

IllegalStateException - if the MAC is not initialised.

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

doFinal

int doFinal(byte[] out,
            int outOff)
            throws DataLengthException,
                   IllegalStateException

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.

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.

IllegalStateException - if the MAC is not initialised.

reset

void reset()

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).