javax.crypto

Class SecretKeyFactory

java.lang.Object

javax.crypto.SecretKeyFactory

public class SecretKeyFactory
extends Object

The public API for SecretKeyFactory implementations.

Secret key factories provide the following functionality:

• convert SecretKey objects to and from KeySpec objects
• translate SecretKey objects from one provider implementation to another

Which key specifications are supported by the generateSecret(java.security.spec.KeySpec) and getKeySpec(javax.crypto.SecretKey, java.lang.Class) is provider dependent.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	SecretKeyFactory(SecretKeyFactorySpi keyFacSpi, Provider provider, String algorithm) Creates a new SecretKeyFactory

Method Summary

Modifier and Type	Method and Description
SecretKey	generateSecret(KeySpec keySpec) Generate a secret key from the specified key specification.
String	getAlgorithm() Returns the name of the secret key algorithm.
static SecretKeyFactory	getInstance(String algorithm) Creates a new SecretKeyFactory instance for the specified key algorithm.
static SecretKeyFactory	getInstance(String algorithm, Provider provider) Creates a new SecretKeyFactory instance for the specified key algorithm from the specified provider.
static SecretKeyFactory	getInstance(String algorithm, String provider) Creates a new SecretKeyFactory instance for the specified key algorithm from the specified provider.
KeySpec	getKeySpec(SecretKey key, Class keySpec) Returns the key specification of the specified secret key.
Provider	getProvider() Returns the provider for this SecretKeyFactory instance.
SecretKey	translateKey(SecretKey key) Translates the specified secret key into an instance of the corresponding key from the provider of this key factory.

Methods inherited from class java.lang.Object

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

Constructor Detail

SecretKeyFactory

protected SecretKeyFactory(SecretKeyFactorySpi keyFacSpi,
                           Provider provider,
                           String algorithm)

Creates a new SecretKeyFactory

Parameters:

keyFacSpi - the SPI delegate.

provider - the provider providing this key factory.

algorithm - the algorithm name for the secret key.

Method Detail

getAlgorithm

public final String getAlgorithm()

Returns the name of the secret key algorithm.

Returns:

the name of the secret key algorithm.

getProvider

public final Provider getProvider()

Returns the provider for this SecretKeyFactory instance.

Returns:

the provider for this SecretKeyFactory instance.

getInstance

public static final SecretKeyFactory getInstance(String algorithm)
                                          throws NoSuchAlgorithmException

Creates a new SecretKeyFactory instance for the specified key algorithm.

Parameters:

algorithm - the name of the key algorithm.

Returns:

a secret key factory for the specified key algorithm.

Throws:

NoSuchAlgorithmException - if no installed provider can provide the requested algorithm.

NullPointerException - if the specified algorithm is null.

getInstance

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

Creates a new SecretKeyFactory instance for the specified key algorithm from the specified provider.

Parameters:

algorithm - the name of the key algorithm.

provider - the name of the provider that provides the requested algorithm.

Returns:

a secret key factory for the specified key algorithm from the specified provider.

Throws:

NoSuchAlgorithmException - if the specified provider cannot provide the requested algorithm.

NoSuchProviderException - if the specified provider does not exist.

IllegalArgumentException - if the specified provider name is null or empty.

getInstance

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

Creates a new SecretKeyFactory instance for the specified key algorithm from the specified provider. The provider supplied does not have to be registered.

Parameters:

algorithm - the name of the key algorithm.

provider - the provider that provides the requested algorithm.

Returns:

a secret key factory for the specified key algorithm from the specified provider.

Throws:

NoSuchAlgorithmException - if the specified provider cannot provider the requested algorithm.

IllegalArgumentException - if the specified provider is null.

NullPointerException - is the specified algorithm name is null.

generateSecret

public final SecretKey generateSecret(KeySpec keySpec)
                               throws InvalidKeySpecException

Generate a secret key from the specified key specification.

Parameters:

keySpec - the key specification.

Returns:

a secret key.

Throws:

InvalidKeySpecException - if the specified key specification cannot be used to generate a secret key.

getKeySpec

public final KeySpec getKeySpec(SecretKey key,
                                Class keySpec)
                         throws InvalidKeySpecException

Returns the key specification of the specified secret key.

Parameters:

key - the secret key to get the specification from.

keySpec - the target key specification class.

Returns:

an instance of the specified key specification class.

Throws:

InvalidKeySpecException - if the specified secret key cannot be transformed into the requested key specification.

translateKey

public final SecretKey translateKey(SecretKey key)
                             throws InvalidKeyException

Translates the specified secret key into an instance of the corresponding key from the provider of this key factory.

Parameters:

key - the secret key to translate.

Returns:

the corresponding translated key.

Throws:

InvalidKeyException - if the specified key cannot be translated using this key factory.