iaik.security.dh
Class DHKeyFactory

java.lang.Object
  |
  +--java.security.KeyFactorySpi
        |
        +--iaik.security.dh.DHKeyFactory

public final class DHKeyFactory

extends KeyFactorySpi

This class converts Diffie Hellman keys (opaque representation) in their KeySpecs (transparent representation) and vice versa.

• DHPublicKey <--> DHPublicKeySpec or X509EncodedKeySpec
• DHPrivateKey <--> DHPrivateKeySpec or PKCS8EncodedKeySpec

To convert, for instance, DER encoded PKCS#8 private key material (e.g. pkcs8_key_spec instantiated from PKCS8EncodedKeySpec) into DHPrivateKey representation, use this KeyFactory for DH keys:

 KeyFactory dh_key_fac = KeyFactory.getInstance("DH");
 DHPrivateKey dh_priv_key = (DHPrivateKey)dh_key_fac.generatePrivate(pkcs8_key_spec);
 

See Also:

DHPrivateKeySpec, DHPublicKeySpec, DHPrivateKey, DHPublicKey, DHKeyAgreement

Constructor Summary

DHKeyFactory()
Default constructor for creating a DHKeyFactory.

Method Summary

protected PrivateKey	engineGeneratePrivate(KeySpec keySpec) Converts the given key specification to a PrivateKey.
protected PublicKey	engineGeneratePublic(KeySpec keySpec) Converts the given key specification to a PublicKey.
protected KeySpec	engineGetKeySpec(Key key, java.lang.Class classSpec) Converts the given key into the requested key specification (key material).
protected Key	engineTranslateKey(Key key) Translates the given key object of some unknown or untrusted provider into a key object supported by this DH key factory.

Methods inherited from class java.lang.Object

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

Constructor Detail

DHKeyFactory

public DHKeyFactory()

Default constructor for creating a DHKeyFactory. Applications shall use KeyFactory.getInstance("DH"); for instantiating a DHKeyFactory.

Method Detail

engineGeneratePrivate

protected PrivateKey engineGeneratePrivate(KeySpec keySpec)
                                    throws InvalidKeySpecException

Converts the given key specification to a PrivateKey. The given key material may either be a DHPrivateKeySpec or a PKCS8EncodedKeySpec.

Overrides:

engineGeneratePrivate in class KeyFactorySpi

Parameters:

keySpec - the key specification as DHPrivateKeySpec or PKCS8EncodedKeySpec

Returns:

the resulting PrivateKey

Throws:

InvalidKeySpecException - if the given key material is not a DHPrivateKeySpec or PKCS8EncodedKeySpec

engineGeneratePublic

protected PublicKey engineGeneratePublic(KeySpec keySpec)
                                  throws InvalidKeySpecException

Converts the given key specification to a PublicKey. The given key material may either be a DHPublicKeySpec or a X509EncodedKeySpec.

Overrides:

engineGeneratePublic in class KeyFactorySpi

Parameters:

keySpec - the key specification as DHPublicKeySpec or X509EncodedKeySpec

Returns:

the resulting PublicKey

Throws:

InvalidKeySpecException - if the given key material is not a DHPublicKeySpec or X509EncodedKeySpec

engineGetKeySpec

protected KeySpec engineGetKeySpec(Key key,
                                   java.lang.Class classSpec)
                            throws InvalidKeySpecException

Converts the given key into the requested key specification (key material). The given key may either be a DHPublicKey or a DHPrivateKey. If the key is a DHPublicKey, this method only can create a DHPublicKeySpec or a X509EncodedKeySpec from it. If the given key is a DHPrivateKey, a DHPrivateKeySpec or a PKCS8EncodedKeySpec may be returned, depending on which of these two types of specifications is requested by classSpec. Each attempt to get key material of a type not matching to a given DH key will raise an exception.

Overrides:

engineGetKeySpec in class KeyFactorySpi

Parameters:

key - the key to be converted, which either may be a DHPublicKey or a DHPrivateKey.

keySpec - the key specification type into which the key shall be converted, which may be a DHPublicKeySpec or a X509EncodedKeySpec if the given key is a DHPublicKey, or a DHPrivateKeySpec or a PKCS8EncodedKeySpec if the given key is a DHPrivateKey

Returns:

the key specification (key material) derived from the given key

Throws:

InvalidKeySpecException - if the given key cannot be converted into the requested key specification object by this key factory

engineTranslateKey

protected Key engineTranslateKey(Key key)
                          throws InvalidKeyException

Translates the given key object of some unknown or untrusted provider into a key object supported by this DH key factory. This method only can translate keys of type DHPublicKey or DHPrivateKey.

Overrides:

engineTranslateKey in class KeyFactorySpi

Parameters:

key - the key of some unknown or untrusted provider

Returns:

the translated key

Throws:

InvalidKeyException - if the given key cannot be translated by this key factory