javax.crypto
Class KeyGeneratorSpi

java.lang.Object
  |
  +--javax.crypto.KeyGeneratorSpi

Direct Known Subclasses:

iaik.pkcs.pkcs12.KeyMaterialGenerator, PBKDF2, iaik.security.cipher.VarLengthKeyGenerator

public abstract class KeyGeneratorSpi

extends Object

Service Provider Interface (SPI) for the KeyGenerator class.

Attention: This is not a SUN implementation!

This class has been developed by IAIK according to the documentation publicly available.
For SUNīs documentation of this class see http://java.sun.com/security/JCE1.2/spec/apidoc/index.html

This SPI class gives a set of abstract methods that have to be implemented by a particular provider for every symmetric algorithm that will need some key generation mechanism for creating secret keys.

The corresponding API class actually used by an application for secret key generation is the javax.crypto.KeyGenerator class. For creating a KeyGenerator object, an application shall use one of the KeyGenerator.getInstance method, supplied with the particular symmetric algorithm in mind and (optionally) a particular provider.

For instance:

 KeyGenerator key_gen = KeyGenerator.getInstance("DES");
 

For actually generating the requested secret key from the KeyGenerator object just created (and initialized with one of the init methods), use the generateKey method:

for instance: SecretKey des_key = key_gen.generateKey();

Initializing the key generator maybe done either algorithm-independently with some random seed, or algorithm-specific with some particular algorithm parameter specification. If no explicit initialization is done at all, it is left to the actual provider implementation to take default settings.

Version:

File Revision 15

See Also:

KeyGenerator, SecretKey

Constructor Summary

KeyGeneratorSpi()
Default Constructor for creating a KeyGeneratorSpi object.

Method Summary

protected abstract SecretKey	engineGenerateKey() Actually generates a secret key from this KeyGenerator object.
protected abstract void	engineInit(AlgorithmParameterSpec params, SecureRandom random) Initializes this key generator with given algorithm parameters and random seed.
protected abstract void	engineInit(int strength, SecureRandom random) Initializes this key generator for the given strength with the given random seed
protected abstract void	engineInit(SecureRandom random) Initializes the key generator with the given random seed.

Methods inherited from class java.lang.Object

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

Constructor Detail

KeyGeneratorSpi

public KeyGeneratorSpi()

Default Constructor for creating a KeyGeneratorSpi object.

Method Detail

engineInit

protected abstract void engineInit(SecureRandom random)

Initializes the key generator with the given random seed.

Parameters:

random - the random seed

See Also:

KeyGenerator.init(java.security.SecureRandom)

engineInit

protected abstract void engineInit(int strength,
                                   SecureRandom random)

Initializes this key generator for the given strength with the given random seed

Parameters:

strength - the strength of the key to be created

random - the random seed

engineInit

protected abstract void engineInit(AlgorithmParameterSpec params,
                                   SecureRandom random)
                            throws InvalidAlgorithmParameterException

Initializes this key generator with given algorithm parameters and random seed.

Parameters:

params - the algorithm parameters

random - the random seed

Throws:

InvalidAlgorithmParameterException - if the given algorithm parameters do not match to this KeyGenerator

See Also:

KeyGenerator.init(java.security.SecureRandom)

engineGenerateKey

protected abstract SecretKey engineGenerateKey()

Actually generates a secret key from this KeyGenerator object.

Returns:

the generated secret key

See Also:

KeyGenerator.generateKey()