Java in a Nutshell, 5th Edition [Electronic resources] نسخه متنی

This class defines an API for
translating a secret key between its opaque
SecretKey representation and its transparent
javax.crypto.SecretKeySpec representation. It is
much like java.security.KeyFactory, except that it
works with secret (or symmetric) keys rather than with public and
private (asymmetric) keys. SecretKeyFactory is
algorithm-independent and provider-based, so you must obtain a
SecretKeyFactory object by calling one of the
static getInstance( ) factory methods and
specifying the name of the desired secret-key algorithm and,
optionally, the name of the provider whose implementation is desired.
In Java
5.0, the "SunJCE" provider provides
SecretKeyFactory implementations for algorithms
with the following names:

Once you have obtained a
SecretKeyFactory, use generateSecret(
) to create a SecretKey from a
java.security.spec.KeySpec (or its subclass,
javax.crypto.spec.SecretKeySpec). Or call
getKeySpec( ) to obtain a
KeySpec for a Key object.
Because there can be more than one suitable type of
KeySpec, getKeySpec( ) requires
a Class object to specify the type of the
KeySpec to be created. See also
DESKeySpec, DESedeKeySpec, and
PBEKeySpec in the
javax.crypto.spec package.

public class

SecretKeyFactory {
// Protected Constructors
protected

SecretKeyFactory (SecretKeyFactorySpi

keyFacSpi ,
java.security.Provider

provider , String

algorithm );
// Public Class Methods
public static final SecretKeyFactory

getInstance (String

algorithm )
throws java.security.NoSuchAlgorithmException;
public static final SecretKeyFactory

getInstance (String

algorithm ,
java.security.Provider

provider )
throws java.security.NoSuchAlgorithmException;
public static final SecretKeyFactory

getInstance (String

algorithm ,
String

provider ) throws java.security.NoSuchAlgorithmException,
java.security.NoSuchProviderException;
// Public Instance Methods
public final SecretKey

generateSecret (java.security.spec.KeySpec

keySpec )
throws java.security.spec.InvalidKeySpecException;
public final String

getAlgorithm ( );
public final java.security.spec.KeySpec

getKeySpec (SecretKey

key , Class

keySpec )
throws java.security.spec.InvalidKeySpecException;
public final java.security.Provider

getProvider ( );
public final SecretKey

translateKey (SecretKey

key )
throws java.security.InvalidKeyException;
}