Summary: Protected Ctors | Methods | Inherited Methods | [Expand All]

public class

Mac

extends Object
implements Cloneable

java.lang.Object
↳	javax.crypto.Mac

Class Overview

This class provides the public API for Message Authentication Code (MAC) algorithms.

Summary

Protected Constructors
	Mac(MacSpi macSpi, Provider provider, String algorithm) Creates a new `Mac` instance.

Public Methods
final Object	clone() Clones this `Mac` instance and the underlying implementation.
final void	doFinal(byte[] output, int outOffset) Computes the digest of this MAC based on the data previously specified in `update(byte)` calls and stores the digest in the specified `output` buffer at offset `outOffset`.
final byte[]	doFinal() Computes the digest of this MAC based on the data previously specified in `update(byte)` calls.
final byte[]	doFinal(byte[] input) Computes the digest of this MAC based on the data previously specified on `update(byte)` calls and on the final bytes specified by `input` (or based on those bytes only).
final String	getAlgorithm() Returns the name of the MAC algorithm.
final static Mac	getInstance(String algorithm, String provider) Creates a new `Mac` instance that provides the specified MAC algorithm from the specified provider.
final static Mac	getInstance(String algorithm) Creates a new `Mac` instance that provides the specified MAC algorithm.
final static Mac	getInstance(String algorithm, Provider provider) Creates a new `Mac` instance that provides the specified MAC algorithm from the specified provider.
final int	getMacLength() Returns the length of this MAC (in bytes).
final Provider	getProvider() Returns the provider of this `Mac` instance.
final void	init(Key key, AlgorithmParameterSpec params) Initializes this `Mac` instance with the specified key and algorithm parameters.
final void	init(Key key) Initializes this `Mac` instance with the specified key.
final void	reset() Resets this `Mac` instance to its initial state.
final void	update(byte[] input) Copies the buffer provided as input for further processing.
final void	update(byte input) Updates this `Mac` instance with the specified byte.
final void	update(byte[] input, int offset, int len) Updates this `Mac` instance with the data from the specified buffer `input` from the specified `offset` and length `len`.
final void	update(ByteBuffer input) Updates this `Mac` instance with the data from the specified buffer, starting at `position()`, including the next `remaining()` bytes.

[Expand]

Inherited Methods

From class java.lang.Object

Object	clone() Creates and returns a copy of this `Object`.
boolean	equals(Object o) Compares this instance with the specified object and indicates if they are equal.
void	finalize() Is called before the object's memory is being reclaimed by the VM.
final Class<? extends Object>	getClass() Returns the unique instance of `Class` which represents this object's class.
int	hashCode() Returns an integer hash code for this object.
final void	notify() Causes a thread which is waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
final void	notifyAll() Causes all threads which are waiting on this object's monitor (by means of calling one of the `wait()` methods) to be woken up.
String	toString() Returns a string containing a concise, human-readable description of this object.
final void	wait(long millis, int nanos) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait(long millis) Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object or until the specified timeout expires.
final void	wait() Causes the calling thread to wait until another thread calls the `notify()` or `notifyAll()` method of this object.

Protected Constructors

protected Mac (MacSpi macSpi, Provider provider, String algorithm)

Since: API Level 1

Creates a new Mac instance.

Parameters

macSpi	the implementation delegate.
provider	the implementation provider.
algorithm	the name of the MAC algorithm.

Public Methods

public final Object clone ()

Since: API Level 1

Clones this Mac instance and the underlying implementation.

Returns

the cloned instance.

Throws

CloneNotSupportedException	if the underlying implementation does not support cloning.

public final void doFinal (byte[] output, int outOffset)

Since: API Level 1

Computes the digest of this MAC based on the data previously specified in update(byte) calls and stores the digest in the specified output buffer at offset outOffset.

This Mac instance is reverted to its initial state and can be used to start the next MAC computation with the same parameters or initialized with different parameters.

Parameters

output	the output buffer
outOffset	the offset in the output buffer

Throws

ShortBufferException	if the specified output buffer is either too small for the digest to be stored, the specified output buffer is `null`, or the specified offset is negative or past the length of the output buffer.
IllegalStateException	if this MAC is not initialized.

public final byte[] doFinal ()

Since: API Level 1

Computes the digest of this MAC based on the data previously specified in update(byte) calls.

This Mac instance is reverted to its initial state and can be used to start the next MAC computation with the same parameters or initialized with different parameters.

Returns

the generated digest.

Throws

IllegalStateException	if this MAC is not initialized.

public final byte[] doFinal (byte[] input)

Since: API Level 1

Computes the digest of this MAC based on the data previously specified on update(byte) calls and on the final bytes specified by input (or based on those bytes only).

This Mac instance is reverted to its initial state and can be used to start the next MAC computation with the same parameters or initialized with different parameters.

Parameters

input	the final bytes.

Returns

the generated digest.

Throws

IllegalStateException	if this MAC is not initialized.

public final String getAlgorithm ()

Since: API Level 1

Returns the name of the MAC algorithm.

Returns

the name of the MAC algorithm.

public static final Mac getInstance (String algorithm, String provider)

Since: API Level 1

Creates a new Mac instance that provides the specified MAC algorithm from the specified provider.

Parameters

algorithm	the name of the requested MAC algorithm.
provider	the name of the provider that is providing the algorithm.

Returns

the new Mac instance.

Throws

NoSuchAlgorithmException	if the specified algorithm is not provided by the specified provider.
NoSuchProviderException	if the specified provider is not available.
IllegalArgumentException	if the specified provider name is `null` or empty.
NullPointerException	if `algorithm` is `null` (instead of NoSuchAlgorithmException as in 1.4 release).

public static final Mac getInstance (String algorithm)

Since: API Level 1

Creates a new Mac instance that provides the specified MAC algorithm.

Parameters

algorithm	the name of the requested MAC algorithm.

Returns

the new Mac instance.

Throws

NoSuchAlgorithmException	if the specified algorithm is not available by any provider.
NullPointerException	if `algorithm` is `null` (instead of NoSuchAlgorithmException as in 1.4 release).

public static final Mac getInstance (String algorithm, Provider provider)

Since: API Level 1

Creates a new Mac instance that provides the specified MAC algorithm from the specified provider.

Parameters

algorithm	the name of the requested MAC algorithm.
provider	the provider that is providing the algorithm.

Returns

the new Mac instance.

Throws

NoSuchAlgorithmException	if the specified algorithm is not provided by the specified provider.
IllegalArgumentException	if `provider` is `null`.
NullPointerException	if `algorithm` is `null` (instead of NoSuchAlgorithmException as in 1.4 release).

public final int getMacLength ()

Since: API Level 1

Returns the length of this MAC (in bytes).

Returns

the length of this MAC (in bytes).

public final Provider getProvider ()

Since: API Level 1

Returns the provider of this Mac instance.

Returns

the provider of this Mac instance.

public final void init (Key key, AlgorithmParameterSpec params)

Since: API Level 1

Initializes this Mac instance with the specified key and algorithm parameters.

Parameters

key	the key to initialize this algorithm.
params	the parameters for this algorithm.

Throws

InvalidKeyException	if the specified key cannot be used to initialize this algorithm, or it is null.
InvalidAlgorithmParameterException	if the specified parameters cannot be used to initialize this algorithm.

public final void init (Key key)

Since: API Level 1

Initializes this Mac instance with the specified key.

Parameters

key	the key to initialize this algorithm.

Throws

InvalidKeyException	if initialization fails because the provided key is `null`.
RuntimeException	if the specified key cannot be used to initialize this algorithm.

public final void reset ()

Since: API Level 1

Resets this Mac instance to its initial state.

This Mac instance is reverted to its initial state and can be used to start the next MAC computation with the same parameters or initialized with different parameters.

public final void update (byte[] input)

Since: API Level 1

Copies the buffer provided as input for further processing.

Parameters

input	the buffer.

Throws

IllegalStateException	if this MAC is not initialized.

public final void update (byte input)

Since: API Level 1

Updates this Mac instance with the specified byte.

Parameters

input	the byte

Throws

IllegalStateException	if this MAC is not initialized.

public final void update (byte[] input, int offset, int len)

Since: API Level 1

Updates this Mac instance with the data from the specified buffer input from the specified offset and length len.

Parameters

input	the buffer.
offset	the offset in the buffer.
len	the length of the data in the buffer.

Throws

IllegalStateException	if this MAC is not initialized.
IllegalArgumentException	if `offset` and `len` do not specified a valid chunk in `input` buffer.

public final void update (ByteBuffer input)

Since: API Level 1

Updates this Mac instance with the data from the specified buffer, starting at position(), including the next remaining() bytes.

Parameters

input	the buffer.

Throws

IllegalStateException	if this MAC is not initialized.

Interfaces

Classes

Exceptions

Mac

Class Overview

Summary

Protected Constructors

protected Mac (MacSpi macSpi, Provider provider, String algorithm)

Parameters

Public Methods

public final Object clone ()

Returns

Throws

public final void doFinal (byte[] output, int outOffset)

Parameters

Throws

public final byte[] doFinal ()

Returns

Throws

public final byte[] doFinal (byte[] input)

Parameters

Returns

Throws

public final String getAlgorithm ()

Returns

public static final Mac getInstance (String algorithm, String provider)

Parameters

Returns

Throws

public static final Mac getInstance (String algorithm)

Parameters

Returns

Throws

public static final Mac getInstance (String algorithm, Provider provider)

Parameters

Returns

Throws

public final int getMacLength ()

Returns

public final Provider getProvider ()

Returns

public final void init (Key key, AlgorithmParameterSpec params)

Parameters

Throws

public final void init (Key key)

Parameters

Throws

public final void reset ()

public final void update (byte[] input)

Parameters

Throws

public final void update (byte input)

Parameters

Throws

public final void update (byte[] input, int offset, int len)

Parameters

Throws

public final void update (ByteBuffer input)

Parameters

Throws