java.security.KeyFactorySpi Maven / Gradle / Ivy
/*
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This work corresponds to the API signatures of JSR 219: Foundation
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*/
package java.security;
import java.security.spec.KeySpec;
import java.security.spec.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 bi-directional. 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
*
* @version 1.8, 02/02/00
*
* @see KeyFactory
* @see Key
* @see PublicKey
* @see PrivateKey
* @see java.security.spec.KeySpec
* @see java.security.spec.DSAPublicKeySpec
* @see java.security.spec.X509EncodedKeySpec
*
* @since 1.2
*/
public abstract class KeyFactorySpi
{
public KeyFactorySpi() { }
/**
* Generates a public key object from the provided key
* specification (key material).
*
* @param keySpec the specification (key material) of the public key.
*
* @return the public key.
*
* @exception InvalidKeySpecException if the given key specification
* is inappropriate for this key factory to produce a public key.
*/
protected abstract PublicKey engineGeneratePublic(KeySpec keySpec)
throws InvalidKeySpecException;
/**
* Generates a private key object from the provided key
* specification (key material).
*
* @param keySpec the specification (key material) of the private key.
*
* @return the private key.
*
* @exception InvalidKeySpecException if the given key specification
* is inappropriate for this key factory to produce a private key.
*/
protected abstract PrivateKey engineGeneratePrivate(KeySpec 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.
*
* @param key the key.
*
* @param keySpec the specification class in which
* the key material should be returned.
*
* @return the underlying key specification (key material) in an instance
* of the requested specification class.
*
* @exception 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).
*/
protected abstract KeySpec engineGetKeySpec(Key key, Class keySpec)
throws InvalidKeySpecException;
/**
* Translates a key object, whose provider may be unknown or
* potentially untrusted, into a corresponding key object of this key
* factory.
*
* @param key the key whose provider is unknown or untrusted.
*
* @return the translated key.
*
* @exception InvalidKeyException if the given key cannot be processed
* by this key factory.
*/
protected abstract Key engineTranslateKey(Key key)
throws InvalidKeyException;
}