public class SecretKeyFactory extends Object
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. Secret key factories operate only on secret (symmetric) keys.
Key factories are bidirectional, i.e., they allow 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.
Application developers should refer to their provider's documentation to find out which key specifications are supported by the generateSecret
and getKeySpec
methods. For example, the DESede (Triple DES) secret-key factory supplied by the "SunJCE" provider supports DESedeKeySpec
as a transparent representation of Triple DES keys.
Every implementation of the Java platform is required to support the following standard SecretKeyFactory
algorithms:
DESede
Modifier | Constructor | Description |
---|---|---|
protected |
Creates a SecretKeyFactory object. |
Modifier and Type | Method | Description |
---|---|---|
final SecretKey |
generateSecret |
Generates a SecretKey object from the provided key specification (key material). |
final String |
getAlgorithm() |
Returns the algorithm name of this SecretKeyFactory object. |
static final SecretKeyFactory |
getInstance |
Returns a SecretKeyFactory object that converts secret keys of the specified algorithm. |
static final SecretKeyFactory |
getInstance |
Returns a SecretKeyFactory object that converts secret keys of the specified algorithm. |
static final SecretKeyFactory |
getInstance |
Returns a SecretKeyFactory object that converts secret keys of the specified algorithm. |
final KeySpec |
getKeySpec |
Returns a specification (key material) of the given key object in the requested format. |
final Provider |
getProvider() |
Returns the provider of this SecretKeyFactory object. |
final SecretKey |
translateKey |
Translates a key object, whose provider may be unknown or potentially untrusted, into a corresponding key object of this secret-key factory. |
protected SecretKeyFactory(SecretKeyFactorySpi keyFacSpi, Provider provider, String algorithm)
SecretKeyFactory
object.keyFacSpi
- the delegateprovider
- the provideralgorithm
- the secret-key algorithmpublic static final SecretKeyFactory getInstance(String algorithm) throws NoSuchAlgorithmException
SecretKeyFactory
object that converts secret keys of the specified algorithm. This method traverses the list of registered security providers, starting with the most preferred provider. A new SecretKeyFactory
object encapsulating the SecretKeyFactorySpi
implementation from the first provider that supports the specified algorithm is returned.
Note that the list of registered providers may be retrieved via the Security.getProviders()
method.
jdk.security.provider.preferred
Security
property to determine the preferred provider order for the specified algorithm. This may be different from the order of providers returned by Security.getProviders()
.algorithm
- the standard name of the requested secret-key algorithm. See the SecretKeyFactory section in the Java Security Standard Algorithm Names Specification for information about standard algorithm names.SecretKeyFactory
objectNoSuchAlgorithmException
- if no Provider
supports a SecretKeyFactorySpi
implementation for the specified algorithmNullPointerException
- if algorithm
is null
public static final SecretKeyFactory getInstance(String algorithm, String provider) throws NoSuchAlgorithmException, NoSuchProviderException
SecretKeyFactory
object that converts secret keys of the specified algorithm. A new SecretKeyFactory
object encapsulating the SecretKeyFactorySpi
implementation from the specified provider is returned. The specified provider must be registered in the security provider list.
Note that the list of registered providers may be retrieved via the Security.getProviders()
method.
algorithm
- the standard name of the requested secret-key algorithm. See the SecretKeyFactory section in the Java Security Standard Algorithm Names Specification for information about standard algorithm names.provider
- the name of the provider.SecretKeyFactory
objectIllegalArgumentException
- if the provider
is null
or emptyNoSuchAlgorithmException
- if a SecretKeyFactorySpi
implementation for the specified algorithm is not available from the specified providerNoSuchProviderException
- if the specified provider is not registered in the security provider listNullPointerException
- if algorithm
is null
public static final SecretKeyFactory getInstance(String algorithm, Provider provider) throws NoSuchAlgorithmException
SecretKeyFactory
object that converts secret keys of the specified algorithm. A new SecretKeyFactory
object encapsulating the SecretKeyFactorySpi
implementation from the specified provider object is returned. Note that the specified provider object does not have to be registered in the provider list.
algorithm
- the standard name of the requested secret-key algorithm. See the SecretKeyFactory section in the Java Security Standard Algorithm Names Specification for information about standard algorithm names.provider
- the provider.SecretKeyFactory
objectIllegalArgumentException
- if the provider
is null
NoSuchAlgorithmException
- if a SecretKeyFactorySpi
implementation for the specified algorithm is not available from the specified Provider
objectNullPointerException
- if algorithm
is null
public final Provider getProvider()
SecretKeyFactory
object.SecretKeyFactory
objectpublic final String getAlgorithm()
SecretKeyFactory
object. This is the same name that was specified in one of the getInstance
calls that created this SecretKeyFactory
object.
SecretKeyFactory
object.public final SecretKey generateSecret(KeySpec keySpec) throws InvalidKeySpecException
SecretKey
object from the provided key specification (key material).keySpec
- the specification (key material) of the secret keyInvalidKeySpecException
- if the given key specification is inappropriate for this secret-key factory to produce a secret key.public final KeySpec getKeySpec(SecretKey key, Class<?> keySpec) throws InvalidKeySpecException
key
- the keykeySpec
- the requested format in which the key material shall be returnedInvalidKeySpecException
- 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).public final SecretKey translateKey(SecretKey key) throws InvalidKeyException
key
- the key whose provider is unknown or untrustedInvalidKeyException
- if the given key cannot be processed by this secret-key factory.
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https://docs.oracle.com/en/java/javase/21/docs/api/java.base/javax/crypto/SecretKeyFactory.html