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package javax.crypto;

import java.security.*;
import java.security.spec.*;


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.

Author:Jan Luehe
See Also:
Since:1.4
/**
 * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>)
 * for the <code>SecretKeyFactory</code> 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.
 *
 * <P> 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 <code>DESKeySpec</code> as a transparent representation of DES
 * keys, and that provider's secret-key factory for Triple DES keys supports
 * <code>DESedeKeySpec</code> as a transparent representation of Triple DES
 * keys.
 *
 * @author Jan Luehe
 *
 * @see SecretKey
 * @see javax.crypto.spec.DESKeySpec
 * @see javax.crypto.spec.DESedeKeySpec
 * @since 1.4
 */

public abstract class SecretKeyFactorySpi {

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

Params:
  • keySpec – the specification (key material) of the secret key
Throws:
  • InvalidKeySpecException – if the given key specification
is inappropriate for this secret-key factory to produce a secret key.
Returns:the secret key
/**
     * Generates a <code>SecretKey</code> object from the
     * provided key specification (key material).
     *
     * @param keySpec the specification (key material) of the secret key
     *
     * @return the secret key
     *
     * @exception InvalidKeySpecException if the given key specification
     * is inappropriate for this secret-key factory to produce a secret key.
     */
    protected abstract SecretKey engineGenerateSecret(KeySpec keySpec)
        throws InvalidKeySpecException;

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

Params:
  • key – the key
  • keySpec – the requested format in which the key material shall be
returned
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).
Returns:the underlying key specification (key material) in the
requested format
/**
     * Returns a specification (key material) of the given key
     * object in the requested format.
     *
     * @param key the key
     *
     * @param keySpec the requested format in which the key material shall be
     * returned
     *
     * @return the underlying key specification (key material) in the
     * requested format
     *
     * @exception InvalidKeySpecException if the requested key specification is
     * inappropriate for the given key (e.g., the algorithms associated with
     * <code>key</code> and <code>keySpec</code> do not match, or
     * <code>key</code> references a key on a cryptographic hardware device
     * whereas <code>keySpec</code> 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).
     */
    protected abstract KeySpec engineGetKeySpec(SecretKey key, Class<?> keySpec)
        throws InvalidKeySpecException;

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

Params:
  • key – the key whose provider is unknown or untrusted
Throws:
Returns:the translated key
/**
     * Translates a key object, whose provider may be unknown or
     * potentially untrusted, into a corresponding key object of this
     * secret-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 secret-key factory.
     */
    protected abstract SecretKey engineTranslateKey(SecretKey key)
        throws InvalidKeyException;
}