javax.crypto

Class KeyGenerator

java.lang.Object

javax.crypto.KeyGenerator

public class KeyGenerator
extends Object

This class provides the public API for generating symmetric cryptographic keys.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	KeyGenerator(KeyGeneratorSpi keyGenSpi, Provider provider, String algorithm) Creates a new KeyGenerator instance.

Method Summary

Modifier and Type	Method and Description
SecretKey	generateKey() Generates a secret key.
String	getAlgorithm() Returns the name of the key generation algorithm.
static KeyGenerator	getInstance(String algorithm) Creates a new KeyGenerator instance that provides the specified key algorithm,
static KeyGenerator	getInstance(String algorithm, Provider provider) Creates a new KeyGenerator instance that provides the specified key algorithm from the specified provider.
static KeyGenerator	getInstance(String algorithm, String provider) Creates a new KeyGenerator instance that provides the specified key algorithm from the specified provider.
Provider	getProvider() Returns the provider of this KeyGenerator instance.
void	init(AlgorithmParameterSpec params) Initializes this KeyGenerator instance with the specified algorithm parameters.
void	init(AlgorithmParameterSpec params, SecureRandom random) Initializes this KeyGenerator instance with the specified algorithm parameters and randomness source.
void	init(int keysize) Initializes this KeyGenerator instance for the specified key size (in bits).
void	init(int keysize, SecureRandom random) Initializes this KeyGenerator instance for the specified key size (in bits) using the specified randomness source.
void	init(SecureRandom random) Initializes this KeyGenerator with the specified randomness source.

Methods inherited from class java.lang.Object

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

Constructor Detail

KeyGenerator

protected KeyGenerator(KeyGeneratorSpi keyGenSpi,
                       Provider provider,
                       String algorithm)

Creates a new KeyGenerator instance.

Parameters:

keyGenSpi - the implementation delegate.

provider - the implementation provider.

algorithm - the name of the algorithm.

Method Detail

getAlgorithm

public final String getAlgorithm()

Returns the name of the key generation algorithm.

Returns:

the name of the key generation algorithm.

getProvider

public final Provider getProvider()

Returns the provider of this KeyGenerator instance.

Returns:

the provider of this KeyGenerator instance.

getInstance

public static final KeyGenerator getInstance(String algorithm)
                                      throws NoSuchAlgorithmException

Creates a new KeyGenerator instance that provides the specified key algorithm,

Parameters:

algorithm - the name of the requested key algorithm

Returns:

the new KeyGenerator instance.

Throws:

NoSuchAlgorithmException - if the specified algorithm is not available by any provider.

NullPointerException - if algorithm is null.

getInstance

public static final KeyGenerator getInstance(String algorithm,
                                             String provider)
                                      throws NoSuchAlgorithmException,
                                             NoSuchProviderException

Creates a new KeyGenerator instance that provides the specified key algorithm from the specified provider.

Parameters:

algorithm - the name of the requested key algorithm.

provider - the name of the provider that is providing the algorithm.

Returns:

the new KeyGenerator 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 is name is null or empty.

NullPointerException - if the specified algorithm name is null.

getInstance

public static final KeyGenerator getInstance(String algorithm,
                                             Provider provider)
                                      throws NoSuchAlgorithmException

Creates a new KeyGenerator instance that provides the specified key algorithm from the specified provider. The provider supplied does not have to be registered.

Parameters:

algorithm - the name of the requested key algorithm.

provider - the provider that is providing the algorithm

Returns:

the new KeyGenerator instance.

Throws:

NoSuchAlgorithmException - if the specified algorithm is not provided by the specified provider.

IllegalArgumentException - if the specified provider is null.

NullPointerException - if the specified algorithm name is null.

generateKey

public final SecretKey generateKey()

Generates a secret key.

Returns:

the generated secret key.

init

public final void init(AlgorithmParameterSpec params)
                throws InvalidAlgorithmParameterException

Initializes this KeyGenerator instance with the specified algorithm parameters.

Parameters:

params - the parameters for the key generation algorithm.

Throws:

InvalidAlgorithmParameterException - if the parameters cannot be used to initialize this key generator algorithm.

init

public final void init(AlgorithmParameterSpec params,
                       SecureRandom random)
                throws InvalidAlgorithmParameterException

Initializes this KeyGenerator instance with the specified algorithm parameters and randomness source.

Parameters:

params - the parameters for the key generation algorithm.

random - the randomness source for any random bytes.

Throws:

InvalidAlgorithmParameterException - if the parameters cannot be uses to initialize this key generator algorithm.

init

public final void init(int keysize)

Initializes this KeyGenerator instance for the specified key size (in bits).

Parameters:

keysize - the size of the key (in bits).

init

public final void init(int keysize,
                       SecureRandom random)

Initializes this KeyGenerator instance for the specified key size (in bits) using the specified randomness source.

Parameters:

keysize - the size of the key (in bits).

random - the randomness source for any random bytes.

init

public final void init(SecureRandom random)

Initializes this KeyGenerator with the specified randomness source.

Parameters:

random - the randomness source for any random bytes.