iaik.security.rsa

Class RSAKeyFactory

java.lang.Object

java.security.KeyFactorySpi

iaik.security.rsa.RSAKeyFactory

public final class RSAKeyFactory
extends java.security.KeyFactorySpi

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

• RSAPublicKey <--> RSAPublicKeySpec or X509EncodedKeySpec
• RSAPrivateKey <--> RSAPrivateKeySpec or RSAPrivateKeyCrtSpec or PKCS8EncodedKeySpec

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

 KeyFactory rsa_key_fac = KeyFactory.getInstance("RSA");
 RSAPrivateKey rsa_priv_key = (RSAPrivateKey)rsa_key_fac.generatePrivate(pkcs8_key_spec);
 

See Also:

RSAPrivateKey, RSAPublicKey

Constructor Summary

Constructors

Constructor and Description
RSAKeyFactory() Default constructor for creating a RSAKeyFactory.

Method Summary

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

Methods inherited from class java.lang.Object

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

Constructor Detail

RSAKeyFactory

public RSAKeyFactory()

Default constructor for creating a RSAKeyFactory. Applications shall use

 KeyFactory.getInstance("RSA");
 

for instantiating a RSAKeyFactory.

Method Detail

engineGeneratePrivate

protected java.security.PrivateKey engineGeneratePrivate(java.security.spec.KeySpec keySpec)
                                                  throws java.security.spec.InvalidKeySpecException

Converts the given key specification to a PrivateKey.

The given key material may either be a RSAPrivateKeySpec or RSAPrivateKeyCrtSpec, or a PKCS8EncodedKeySpec.

Specified by:

engineGeneratePrivate in class java.security.KeyFactorySpi

Parameters:

keySpec - the key specification as RSAPrivateKeySpec, RSAPrivateKeyCrtSpec or PKCS8EncodedKeySpec

Returns:

the resulting PrivateKey

Throws:

java.security.spec.InvalidKeySpecException - if the given key material is not a RSAPrivateKeySpec, RSAPrivateKeyCrtSpec or PKCS8EncodedKeySpec

engineGeneratePublic

protected java.security.PublicKey engineGeneratePublic(java.security.spec.KeySpec keySpec)
                                                throws java.security.spec.InvalidKeySpecException

Converts the given key specification to a PublicKey.

The given key material may either be a RSAPublicKeySpec or a X509EncodedKeySpec.

Specified by:

engineGeneratePublic in class java.security.KeyFactorySpi

Parameters:

keySpec - the key specification as RSAPublicKeySpec or X509EncodedKeySpec

Returns:

the resulting PublicKey

Throws:

java.security.spec.InvalidKeySpecException - if the given key material is not a RSAPublicKeySpec or X509EncodedKeySpec

engineGetKeySpec

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

Converts the given key into the requested key specification (key material).

The given key may either be a RSAPublicKey or a RSAPrivateKey. If the key is a RSAPublicKey, this method only can create a RSAPublicKeySpec or a X509EncodedKeySpec from it. If the given key is a RSAPrivateKey, a RSAPrivateKeySpec, RSAPrivateCrtKeySpec, or a PKCS8EncodedKeySpec may be returned, depending on which of these types of specifications is requested by classSpec. Each attempt to get key material of a type not matching to a given RSA key will raise an exception.

Specified by:

engineGetKeySpec in class java.security.KeyFactorySpi

Parameters:

key - the key to be converted, which either may be a RSAPublicKey or a RSAPrivateKey.

classSpec - the key specification type into which the key shall be converted, which may be a RSAPublicKeySpec or a X509EncodedKeySpec if the given key is a RSAPublicKey, or a RSAPrivateKey(Crt)Spec or a PKCS8EncodedKeySpec if the given key is a RSAPrivateKey

Returns:

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

Throws:

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

engineTranslateKey

protected java.security.Key engineTranslateKey(java.security.Key key)
                                        throws java.security.InvalidKeyException

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

Specified by:

engineTranslateKey in class java.security.KeyFactorySpi

Parameters:

key - the key of some unknown or untrusted provider

Returns:

the translated key

Throws:

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