net.sf.mmm.crypto.crypt

Class CryptorImplCipher

java.lang.Object

net.sf.mmm.crypto.algorithm.AbstractSecurityAlgorithm

net.sf.mmm.crypto.algorithm.AbstractCryptoAlgorithmWithProvider

net.sf.mmm.crypto.algorithm.AbstractCryptoAlgorithmWithRandom

net.sf.mmm.crypto.crypt.CryptorImplCipher

All Implemented Interfaces:

CryptoAlgorithm, AbstractGetNonceSize, Cryptor, CryptoProcessor

Direct Known Subclasses:

DecryptorImplCipher, EncryptorImplCiper

public abstract class CryptorImplCipher
extends AbstractCryptoAlgorithmWithRandom
implements Cryptor

Abstract implementation of Cryptor based on Cipher.

Since:

1.0.0

Author:

Joerg Hohwiller (hohwille at users.sourceforge.net)

Field Summary

Fields

Modifier and Type	Field and Description
private Cipher	cipher
private CryptorConfig	config
private Key	key
private byte[]	nonce
private int	nonceIndex Index in nonce or -1 if nonce has completely been processed.
private int	nonceSize

Fields inherited from class net.sf.mmm.crypto.algorithm.AbstractCryptoAlgorithmWithProvider

provider

Constructor Summary

Constructors

Constructor and Description
CryptorImplCipher(RandomFactory randomFactory, CryptorConfig config, Key key) The constructor.

Method Summary

Modifier and Type	Method and Description
byte[]	crypt(byte[] input, int offset, int length, boolean complete)
String	getAlgorithm()
protected Cipher	getCipher()
CryptorConfig	getConfig()
protected String	getMode()
int	getNonceSize() Unlike Cipher this API is designed for ease of use.
protected abstract boolean	isEncryptor()
private int	readNonce(byte[] input, int off, int len)
void	reset() Will reset the internal state of this object.
protected RuntimeException	wrapSecurityException(Exception e)

Methods inherited from class net.sf.mmm.crypto.algorithm.AbstractCryptoAlgorithmWithRandom

createSecureRandom, getRandomFactory

Methods inherited from class net.sf.mmm.crypto.algorithm.AbstractCryptoAlgorithmWithProvider

getProvider

Methods inherited from class net.sf.mmm.crypto.algorithm.AbstractSecurityAlgorithm

creationFailedException, creationFailedException, creationFailedException, creationFailedException, getAlgorithm, toString

Methods inherited from class java.lang.Object

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

Methods inherited from interface net.sf.mmm.crypto.crypt.Cryptor

crypt, crypt, doFinal, process

Methods inherited from interface net.sf.mmm.crypto.CryptoProcessor

process, process, process

Field Detail

config

private final CryptorConfig config

key

private final Key key

nonceSize

private final int nonceSize

cipher

private Cipher cipher

nonce

private byte[] nonce

nonceIndex

private int nonceIndex

Index in nonce or -1 if nonce has completely been processed.

Constructor Detail

CryptorImplCipher

public CryptorImplCipher(RandomFactory randomFactory,
                         CryptorConfig config,
                         Key key)

The constructor.

Parameters:

randomFactory - the RandomFactory to use.

config - the CryptorConfig.

key - the Key to use.

Method Detail

getAlgorithm

public String getAlgorithm()

Specified by:

getAlgorithm in interface CryptoAlgorithm

Returns:

the name of the underlying algorithm (e.g. "RSA", "NONEwithECDSA", etc.).

See Also:

Key.getAlgorithm(), Signature.getAlgorithm(), MessageDigest.getAlgorithm(), SecureRandom.getAlgorithm(), Cipher.getAlgorithm()

getNonceSize

public int getNonceSize()

Description copied from interface: AbstractGetNonceSize

Unlike Cipher this API is designed for ease of use. Some cryptographic algorithms require an initialization vector (IV) and others do not. With this API you do not have to care and cannot do things wrong. The nonce will be prepended automatically to the encrypted payload and reconstructed from there on decryption. This works both for crypt and for streaming.

Specified by:

getNonceSize in interface AbstractGetNonceSize

Returns:

the size of the nonce in bytes or 0 for none.

See Also:

Cipher.getIV()

getCipher

protected Cipher getCipher()

Returns:

the underlying Cipher.

isEncryptor

protected abstract boolean isEncryptor()

Returns:

true if Encryptor, false if Decryptor.

getConfig

public final CryptorConfig getConfig()

Returns:

the CryptorConfig.

getMode

protected String getMode()

Returns:

"decryption" for Decryptor and "encryption" for Encryptor.

readNonce

private int readNonce(byte[] input,
                      int off,
                      int len)

crypt

public byte[] crypt(byte[] input,
                    int offset,
                    int length,
                    boolean complete)

Specified by:

crypt in interface Cryptor

Parameters:

input - the next chunk of data to encrypt or decrypt.

offset - the offset where to start in the input array.

length - the number of bytes to read from the input array.

complete - - true to complete the encryption or decryption in case this is the last chunk of data, false otherwise.

Returns:

the number of bytes that have been written into the output array.

See Also:

Cipher.update(byte[], int, int), Cipher.doFinal(byte[], int, int)

wrapSecurityException

protected RuntimeException wrapSecurityException(Exception e)

Parameters:

e - the Exception to wrap.

Returns:

the wrapped RuntimeException.

reset

public void reset()

Description copied from interface: CryptoProcessor

Will reset the internal state of this object. Please note that complex algorithms especially for Cryptor may not reusable. It is therefore preferable to always create a fresh instance for each cryptographic task.

Specified by:

reset in interface CryptoProcessor

See Also:

MessageDigest.reset()