Class NullCipher

java.lang.Object

javax.crypto.Cipher

javax.crypto.NullCipher

public class NullCipher
extends Cipher

The NullCipher class is a class that provides an "identity cipher" -- one that does not transform the plain text. As a consequence, the ciphertext is identical to the plaintext. All initialization methods do nothing, while the blocksize is set to 1 byte. Unlike other ciphers, the NullCipher has no state, and will never throw an IllegalStateException when Cipher methods are called.

Since:

1.4

Field Summary

Fields declared in class Cipher

DECRYPT_MODE, ENCRYPT_MODE, PRIVATE_KEY, PUBLIC_KEY, SECRET_KEY, UNWRAP_MODE, WRAP_MODE

Modifier and Type	Field	Description
static final int	DECRYPT_MODE	Constant used to initialize cipher to decryption mode.
static final int	ENCRYPT_MODE	Constant used to initialize cipher to encryption mode.
static final int	PRIVATE_KEY	Constant used to indicate the to-be-unwrapped key is a "private key".
static final int	PUBLIC_KEY	Constant used to indicate the to-be-unwrapped key is a "public key".
static final int	SECRET_KEY	Constant used to indicate the to-be-unwrapped key is a "secret key".
static final int	UNWRAP_MODE	Constant used to initialize cipher to key-unwrapping mode.
static final int	WRAP_MODE	Constant used to initialize cipher to key-wrapping mode.

Constructor Summary

Constructors

Constructor	Description
NullCipher()	Creates a NullCipher object.

Method Summary

Methods declared in class Cipher

doFinal, doFinal, doFinal, doFinal, doFinal, doFinal, doFinal, getAlgorithm, getBlockSize, getExemptionMechanism, getInstance, getInstance, getInstance, getIV, getMaxAllowedKeyLength, getMaxAllowedParameterSpec, getOutputSize, getParameters, getProvider, init, init, init, init, init, init, init, init, toString, unwrap, update, update, update, update, update, updateAAD, updateAAD, updateAAD, wrap

Modifier and Type	Method	Description
final byte[]	doFinal()	Finishes a multiple-part encryption or decryption operation, depending on how this Cipher object was initialized.
final byte[]	doFinal(byte[] input)	Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation.
final int	doFinal(byte[] output, int outputOffset)	Finishes a multiple-part encryption or decryption operation, depending on how this Cipher object was initialized.
final byte[]	doFinal(byte[] input, int inputOffset, int inputLen)	Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation.
final int	doFinal(byte[] input, int inputOffset, int inputLen, byte[] output)	Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation.
final int	doFinal(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset)	Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation.
final int	doFinal(ByteBuffer input, ByteBuffer output)	Encrypts or decrypts data in a single-part operation, or finishes a multiple-part operation.
final String	getAlgorithm()	Returns the algorithm name of this Cipher object.
final int	getBlockSize()	Returns the block size (in bytes).
final ExemptionMechanism	getExemptionMechanism()	Returns the exemption mechanism object used with this Cipher object.
static final Cipher	getInstance(String transformation)	Returns a Cipher object that implements the specified transformation.
static final Cipher	getInstance(String transformation, String provider)	Returns a Cipher object that implements the specified transformation.
static final Cipher	getInstance(String transformation, Provider provider)	Returns a Cipher object that implements the specified transformation.
final byte[]	getIV()	Returns the initialization vector (IV) in a new buffer.
static final int	getMaxAllowedKeyLength(String transformation)	Returns the maximum key length for the specified transformation according to the installed JCE jurisdiction policy files.
static final AlgorithmParameterSpec	getMaxAllowedParameterSpec(String transformation)	Returns an {code AlgorithmParameterSpec} object which contains the maximum Cipher parameter value according to the jurisdiction policy file.
final int	getOutputSize(int inputLen)	Returns the length in bytes that an output buffer would need to be in order to hold the result of the next update or doFinal operation, given the input length inputLen (in bytes).
final AlgorithmParameters	getParameters()	Returns the parameters used with this Cipher object.
final Provider	getProvider()	Returns the provider of this Cipher object.
final void	init(int opmode, Certificate certificate)	Initializes this Cipher object with the public key from the given certificate.
final void	init(int opmode, Certificate certificate, SecureRandom random)	Initializes this Cipher object with the public key from the given certificate and a source of randomness.
final void	init(int opmode, Key key)	Initializes this Cipher object with a key.
final void	init(int opmode, Key key, AlgorithmParameters params)	Initializes this Cipher object with a key and a set of algorithm parameters.
final void	init(int opmode, Key key, AlgorithmParameters params, SecureRandom random)	Initializes this Cipher object with a key, a set of algorithm parameters, and a source of randomness.
final void	init(int opmode, Key key, SecureRandom random)	Initializes this Cipher object with a key and a source of randomness.
final void	init(int opmode, Key key, AlgorithmParameterSpec params)	Initializes this Cipher object with a key and a set of algorithm parameters.
final void	init(int opmode, Key key, AlgorithmParameterSpec params, SecureRandom random)	Initializes this Cipher object with a key, a set of algorithm parameters, and a source of randomness.
String	toString()	Returns a String representation of this Cipher object.
final Key	unwrap(byte[] wrappedKey, String wrappedKeyAlgorithm, int wrappedKeyType)	Unwrap a previously wrapped key.
final byte[]	update(byte[] input)	Continues a multiple-part encryption or decryption operation (depending on how this Cipher object was initialized), processing another data part.
final byte[]	update(byte[] input, int inputOffset, int inputLen)	Continues a multiple-part encryption or decryption operation (depending on how this Cipher object was initialized), processing another data part.
final int	update(byte[] input, int inputOffset, int inputLen, byte[] output)	Continues a multiple-part encryption or decryption operation (depending on how this Cipher object was initialized), processing another data part.
final int	update(byte[] input, int inputOffset, int inputLen, byte[] output, int outputOffset)	Continues a multiple-part encryption or decryption operation (depending on how this Cipher object was initialized), processing another data part.
final int	update(ByteBuffer input, ByteBuffer output)	Continues a multiple-part encryption or decryption operation (depending on how this Cipher object was initialized), processing another data part.
final void	updateAAD(byte[] src)	Continues a multi-part update of the Additional Authentication Data (AAD).
final void	updateAAD(byte[] src, int offset, int len)	Continues a multi-part update of the Additional Authentication Data (AAD), using a subset of the provided buffer.
final void	updateAAD(ByteBuffer src)	Continues a multi-part update of the Additional Authentication Data (AAD).
final byte[]	wrap(Key key)	Wrap a key.

Methods declared in class Object

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

Modifier and Type	Method	Description
protected Object	clone()	Creates and returns a copy of this object.
boolean	equals(Object obj)	Indicates whether some other object is "equal to" this one.
protected void	finalize()	Deprecated, for removal: This API element is subject to removal in a future version. Finalization is deprecated and subject to removal in a future release.
final Class<?>	getClass()	Returns the runtime class of this Object.
int	hashCode()	Returns a hash code value for this object.
final void	notify()	Wakes up a single thread that is waiting on this object's monitor.
final void	notifyAll()	Wakes up all threads that are waiting on this object's monitor.
final void	wait()	Causes the current thread to wait until it is awakened, typically by being notified or interrupted.
final void	wait(long timeoutMillis)	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.
final void	wait(long timeoutMillis, int nanos)	Causes the current thread to wait until it is awakened, typically by being notified or interrupted, or until a certain amount of real time has elapsed.

Constructor Details

NullCipher

public NullCipher()

Creates a NullCipher object.