Top Description Constructors Methods
java.security

public abstract Class KeyFactorySpi

extends Object
Class Inheritance
Known Direct Subclasses
com.sun.crypto.provider.DHKeyFactory, sun.security.provider.DSAKeyFactory, sun.security.provider.HSS.KeyFactoryImpl, sun.security.rsa.RSAKeyFactory, sun.security.ec.ECKeyFactory, sun.security.ec.XDHKeyFactory, sun.security.ec.ed.EdDSAKeyFactory
Imports
java.security.spec.KeySpec, .InvalidKeySpecException
This class defines the Service Provider Interface (SPI) for the KeyFactory class. All the abstract methods in this class must be implemented by each cryptographic service provider who wishes to supply the implementation of a key factory for a particular algorithm.

Key factories are used to convert keys (opaque cryptographic keys of type Key) into key specifications (transparent representations of the underlying key material), and vice versa.

Key factories are bidirectional. That is, they allow you to build an opaque key object from a given key specification (key material), or to retrieve the underlying key material of a key object in a suitable format.

Multiple compatible key specifications may exist for the same key. For example, a DSA public key may be specified using DSAPublicKeySpec or X509EncodedKeySpec. A key factory can be used to translate between compatible key specifications.

A provider should document all the key specifications supported by its key factory.

Author
Jan Luehe
Since
1.2
See Also
KeyFactory, Key, PublicKey, PrivateKey, java.security.spec.KeySpec, java.security.spec.DSAPublicKeySpec, java.security.spec.X509EncodedKeySpec

Constructor Summary

AccessConstructor and Description
public
KeyFactorySpi()

Constructor for subclasses to call.

Method Summary

Modifier and TypeMethod and Description
protected abstract PrivateKey

Returns:

the private key.
engineGeneratePrivate(KeySpec
the specification (key material) of the private key.
keySpec)

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

protected abstract PublicKey

Returns:

the public key.
engineGeneratePublic(KeySpec
the specification (key material) of the public key.
keySpec)

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

protected abstract <
the type of the key specification to be returned
T extends KeySpec> T

Returns:

the underlying key specification (key material) in an instance of the requested specification class.
engineGetKeySpec(Key
the key.
key, Class<T>
the specification class in which the key material should be returned.
keySpec)

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

protected abstract Key

Returns:

the translated key.
engineTranslateKey(Key
the key whose provider is unknown or untrusted.
key)

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

Inherited from java.lang.Object:
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Constructor Detail

KeyFactorySpiback to summary
public KeyFactorySpi()

Constructor for subclasses to call.

Method Detail

engineGeneratePrivateback to summary
protected abstract PrivateKey engineGeneratePrivate(KeySpec keySpec) throws InvalidKeySpecException

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

Parameters
keySpec:KeySpec

the specification (key material) of the private key.

Returns:PrivateKey

the private key.

Exceptions
InvalidKeySpecException:
if the given key specification is inappropriate for this key factory to produce a private key.
engineGeneratePublicback to summary
protected abstract PublicKey engineGeneratePublic(KeySpec keySpec) throws InvalidKeySpecException

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

Parameters
keySpec:KeySpec

the specification (key material) of the public key.

Returns:PublicKey

the public key.

Exceptions
InvalidKeySpecException:
if the given key specification is inappropriate for this key factory to produce a public key.
engineGetKeySpecback to summary
protected abstract <T extends KeySpec> T engineGetKeySpec(Key key, Class<T> keySpec) throws InvalidKeySpecException

Returns a specification (key material) of the given key object. keySpec identifies the specification class in which the key material should be returned. It could, for example, be DSAPublicKeySpec.class, to indicate that the key material should be returned in an instance of the DSAPublicKeySpec class.

Parameters
<T>
the type of the key specification to be returned
key:Key

the key.

keySpec:Class<T>

the specification class in which the key material should be returned.

Returns:T

the underlying key specification (key material) in an instance of the requested specification class.

Exceptions
InvalidKeySpecException:
if the requested key specification is inappropriate for the given key, or the given key cannot be dealt with (e.g., the given key has an unrecognized format).
engineTranslateKeyback to summary
protected abstract Key engineTranslateKey(Key key) throws InvalidKeyException

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

Parameters
key:Key

the key whose provider is unknown or untrusted.

Returns:Key

the translated key.

Exceptions
InvalidKeyException:
if the given key cannot be processed by this key factory.