edu.vt.middleware.crypt.asymmetric
Class AsymmetricAlgorithm

java.lang.Object
  edu.vt.middleware.crypt.AbstractAlgorithm
      edu.vt.middleware.crypt.AbstractEncryptionAlgorithm
          edu.vt.middleware.crypt.asymmetric.AsymmetricAlgorithm

All Implemented Interfaces:

Algorithm, EncryptionAlgorithm

Direct Known Subclasses:

RSA

public class AsymmetricAlgorithm
extends AbstractEncryptionAlgorithm

Provides asymmetric encryption and decryption operations using a public/private key pair.

Version:

$Revision: 84 $

Author:

Middleware Services

Field Summary

static String	MODE Mode used for encryption and decryption.
static String	PADDING Padding used for encryption and decryption.

Fields inherited from class edu.vt.middleware.crypt.AbstractEncryptionAlgorithm

cipher, cipherMode, key, mode, padding

Fields inherited from class edu.vt.middleware.crypt.AbstractAlgorithm

algorithm, logger, randomByteSize, randomProvider

Constructor Summary

protected

AsymmetricAlgorithm(String cipherAlgorithm) Creates a new instance that uses a cipher of the given algorithm and the default mode and padding.

Method Summary

KeyPair	generateKeys() Generates a public/private key pair of the default length suitable for the cipher used for encryption on this instance.
KeyPair	generateKeys(int bitLength) Generates a public/private key pair of the given length suitable for the cipher used for encryption on this instance.
static KeyPair	generateKeys(String algorithm, int bitLength, SecureRandom random) Generates a public/private key pair using the given cipher algorithm.
protected AlgorithmParameterSpec	getAlgorithmParameterSpec() Gets the algorithm parameter specification for this algorithm.
protected int	getChunkSize() Gets the chunk size for buffers using in stream-based encryption and decryption operations.
int	getDefaultKeyLength() Gets the default key length for this algorithm.
static AsymmetricAlgorithm	newInstance(String algorithm) Creates a new instance that uses a cipher of the given name.

Methods inherited from class edu.vt.middleware.crypt.AbstractEncryptionAlgorithm

crypt, crypt, decrypt, decrypt, decrypt, encrypt, encrypt, encrypt, getBlockSize, getCipherMode, getMode, getPadding, init, initCipher, initDecrypt, initEncrypt, setKey, toString

Methods inherited from class edu.vt.middleware.crypt.AbstractAlgorithm

getAlgorithm, getRandomData, setRandomProvider

Methods inherited from class java.lang.Object

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

Methods inherited from interface edu.vt.middleware.crypt.Algorithm

getAlgorithm, getRandomData, setRandomProvider

Field Detail

MODE

public static final String MODE

Mode used for encryption and decryption.

See Also:

Constant Field Values

PADDING

public static final String PADDING

Padding used for encryption and decryption.

See Also:

Constant Field Values

Constructor Detail

AsymmetricAlgorithm

protected AsymmetricAlgorithm(String cipherAlgorithm)

Creates a new instance that uses a cipher of the given algorithm and the default mode and padding.

Parameters:

cipherAlgorithm - Cipher algorithm name.

Method Detail

newInstance

public static AsymmetricAlgorithm newInstance(String algorithm)

Creates a new instance that uses a cipher of the given name.

Parameters:

algorithm - Cipher algorithm name.

Returns:

Asymmetric algorithm instance that implements the given cipher algorithm.

generateKeys

public static KeyPair generateKeys(String algorithm,
                                   int bitLength,
                                   SecureRandom random)
                            throws CryptException

Generates a public/private key pair using the given cipher algorithm.

Parameters:

algorithm - Name of a cipher algorithm for which a suitable key pair will be generated.

bitLength - Size of each key in pair in bits.

random - Source of randomness used for key generation.

Returns:

Key pair that may be used for encryption/decryption on a cipher of the given algorithm.

Throws:

CryptException - On key pair generation errors.

generateKeys

public KeyPair generateKeys()
                     throws CryptException

Generates a public/private key pair of the default length suitable for the cipher used for encryption on this instance.

Returns:

Key pair that may be used for encryption/decryption on the cipher used by this instance.

Throws:

CryptException - On key pair generation errors.

generateKeys

public KeyPair generateKeys(int bitLength)
                     throws CryptException

Generates a public/private key pair of the given length suitable for the cipher used for encryption on this instance.

Parameters:

bitLength - Size of each key in pair in bits.

Returns:

Key pair that may be used for encryption/decryption on the cipher used by this instance.

Throws:

CryptException - On key pair generation errors.

getDefaultKeyLength

public int getDefaultKeyLength()

Gets the default key length for this algorithm.

Returns:

Default key length in bits.

getAlgorithmParameterSpec

protected AlgorithmParameterSpec getAlgorithmParameterSpec()

Gets the algorithm parameter specification for this algorithm.

Specified by:

getAlgorithmParameterSpec in class AbstractEncryptionAlgorithm

Returns:

Algorithm parameter specification specific to this algorithm.

getChunkSize

protected int getChunkSize()

Gets the chunk size for buffers using in stream-based encryption and decryption operations.

Specified by:

getChunkSize in class AbstractEncryptionAlgorithm

Returns:

Stream chunk size.