javax.crypto
Class SecretKeyFactorySpi

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

public abstract class SecretKeyFactorySpi

extends Object

This class defines the Service Provider Interface (SPI) for the SecretKeyFactory class. All the abstract methods in this class must be implemented by each cryptographic service provider who wishes to supply the implementation of a secret-key factory for a particular algorithm.

A provider should document all the key specifications supported by its secret key factory. For example, the DES secret-key factory supplied by the "SunJCE" provider supports DESKeySpec as a transparent representation of DES keys, and that provider's secret-key factory for Triple DES keys supports DESedeKeySpec as a transparent representation of Triple DES keys.

Since:

1.4

See Also:

SecretKey, DESKeySpec, DESedeKeySpec

Constructor Summary

SecretKeyFactorySpi()

Method Summary

protected abstract SecretKey	engineGenerateSecret(KeySpec keySpec) Generates a SecretKey object from the provided key specification (key material).
protected abstract KeySpec	engineGetKeySpec(SecretKey key, Class keySpec) Returns a specification (key material) of the given key object in the requested format.
protected abstract SecretKey	engineTranslateKey(SecretKey key) Translates a key object, whose provider may be unknown or potentially untrusted, into a corresponding key object of this secret-key factory.

Methods inherited from class java.lang.Object

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

Constructor Detail

SecretKeyFactorySpi

public SecretKeyFactorySpi()

Method Detail

engineGenerateSecret

protected abstract SecretKey engineGenerateSecret(KeySpec keySpec)
                                           throws InvalidKeySpecException

Generates a SecretKey object from the provided key specification (key material).

Parameters:

keySpec - the specification (key material) of the secret key

Returns:

the secret key

Throws:

InvalidKeySpecException - if the given key specification is inappropriate for this secret-key factory to produce a secret key.

engineGetKeySpec

protected abstract KeySpec engineGetKeySpec(SecretKey key,
                                            Class keySpec)
                                     throws InvalidKeySpecException

Returns a specification (key material) of the given key object in the requested format.

Parameters:

key - the key

keySpec - the requested format in which the key material shall be returned

Returns:

the underlying key specification (key material) in the requested format

Throws:

InvalidKeySpecException - if the requested key specification is inappropriate for the given key (e.g., the algorithms associated with key and keySpec do not match, or key references a key on a cryptographic hardware device whereas keySpec is the specification of a software-based key), or the given key cannot be dealt with (e.g., the given key has an algorithm or format not supported by this secret-key factory).

engineTranslateKey

protected abstract SecretKey engineTranslateKey(SecretKey key)
                                         throws InvalidKeyException

Translates a key object, whose provider may be unknown or potentially untrusted, into a corresponding key object of this secret-key factory.

Parameters:

key - the key whose provider is unknown or untrusted

Returns:

the translated key

Throws:

InvalidKeyException - if the given key cannot be processed by this secret-key factory.