org.apache.fulcrum.jce.crypto

Class CryptoStreamFactoryImpl

java.lang.Object

org.apache.fulcrum.jce.crypto.CryptoStreamFactoryTemplate

org.apache.fulcrum.jce.crypto.CryptoStreamFactoryImpl

All Implemented Interfaces:

CryptoStreamFactory

public class CryptoStreamFactoryImpl
extends CryptoStreamFactoryTemplate
implements CryptoStreamFactory

Concrete factory for creating encrypting/decrypting streams. The implementation uses the JCA (Java Crypto Extension) supplied by SUN (using SunJCE 1.42). The implementation uses as PBEWithMD5AndDES for encryption which should be sufficent for most applications. The implementation also supplies a default password in the case that the programmer don't want to have additional hassles. It is easy to reengineer the password being used but much better than a hard-coded password in the application. The code uses parts from Markus Hahn's Blowfish library found at http://blowfishj.sourceforge.net/

Author:

Siegfried Goeschl , Markus Hahn

Field Summary

Fields

Modifier and Type	Field and Description
protected String	algorithm the algorithm to use
protected int	count the count paramter for the PBE algorithm
protected String	providerName the name of the JCE provider
protected static String	PROVIDERNAME The JCE provider name known to work.
protected byte[]	salt the salt for the PBE algorithm

Constructor Summary

Constructors

Constructor and Description
CryptoStreamFactoryImpl() Constructor
CryptoStreamFactoryImpl(byte[] salt, int count) Constructor

Method Summary

Modifier and Type	Method and Description
protected Cipher	createCipher(int mode, char[] password) Create a Cipher.
protected Key	createKey(char[] password) Create a PBE key.
String	getAlgorithm() Info about used algorithm.
protected int	getCount()
static CryptoStreamFactory	getInstance() Factory method to get a default instance
static CryptoStreamFactory	getInstance(byte[] salt, int count) Factory method to get a default instance
protected String	getProviderName()
protected byte[]	getSalt()
InputStream	getSmartInputStream(InputStream is, char[] password) Creates a smart decrypting input stream using a given password.
static void	setInstance(CryptoStreamFactory instance) Set the default instance from an external application.

Methods inherited from class org.apache.fulcrum.jce.crypto.CryptoStreamFactoryTemplate

getInputStream, getInputStream, getInputStream, getInputStream, getOutputStream, getOutputStream, getSmartInputStream

Methods inherited from class java.lang.Object

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

Methods inherited from interface org.apache.fulcrum.jce.crypto.CryptoStreamFactory

getInputStream, getInputStream, getInputStream, getInputStream, getOutputStream, getOutputStream, getSmartInputStream

Field Detail

salt

protected final byte[] salt

the salt for the PBE algorithm

count

protected int count

the count paramter for the PBE algorithm

providerName

protected String providerName

the name of the JCE provider

algorithm

protected String algorithm

the algorithm to use

PROVIDERNAME

protected static final String PROVIDERNAME

The JCE provider name known to work. If the value is set to null an appropriate provider will be used.

Constructor Detail

CryptoStreamFactoryImpl

public CryptoStreamFactoryImpl()

Constructor

CryptoStreamFactoryImpl

public CryptoStreamFactoryImpl(byte[] salt,
                               int count)

Constructor

Parameters:

salt - the salt for the PBE algorithm

count - the iteration for PBEParameterSpec

Method Detail

getInstance

public static CryptoStreamFactory getInstance()

Factory method to get a default instance

Returns:

an instance of the CryptoStreamFactory

setInstance

public static void setInstance(CryptoStreamFactory instance)

Set the default instance from an external application.

Parameters:

instance - the new default instance

getInstance

public static CryptoStreamFactory getInstance(byte[] salt,
                                              int count)

Factory method to get a default instance

Parameters:

salt - the salt for the PBE algorithm

count - the iteration for PBEParameterSpec

Returns:

an instance of the CryptoStreamFactory

getSmartInputStream

public InputStream getSmartInputStream(InputStream is,
                                       char[] password)
                                throws GeneralSecurityException,
                                       IOException

Description copied from interface: CryptoStreamFactory

Creates a smart decrypting input stream using a given password. The implementation looks at the binary content to decide if it was encrypted or not thereby providing transparent access to encrypted/unencrypted files.

Specified by:

getSmartInputStream in interface CryptoStreamFactory

Specified by:

getSmartInputStream in class CryptoStreamFactoryTemplate

Parameters:

is - the input stream to be wrapped

password - the password to be used

Returns:

an decrypting input stream

Throws:

GeneralSecurityException - creating the input stream failed

IOException - creating the input stream failed

See Also:

CryptoStreamFactory.getSmartInputStream(java.io.InputStream,char[])

getAlgorithm

public String getAlgorithm()

Description copied from interface: CryptoStreamFactory

Info about used algorithm.

Specified by:

getAlgorithm in interface CryptoStreamFactory

Returns:

Returns the algorithm.

getCount

protected int getCount()

Returns:

Returns the count.

getProviderName

protected String getProviderName()

Returns:

Returns the providerName.

getSalt

protected byte[] getSalt()

Returns:

Returns the salt.

createKey

protected Key createKey(char[] password)
                 throws GeneralSecurityException

Create a PBE key.

Parameters:

password - the password to use.

Returns:

the key

Throws:

GeneralSecurityException - creating the key failed

createCipher

protected Cipher createCipher(int mode,
                              char[] password)
                       throws GeneralSecurityException,
                              IOException

Create a Cipher.

Specified by:

createCipher in class CryptoStreamFactoryTemplate

Parameters:

mode - the cipher mode

password - the password

Returns:

an instance of a cipher

Throws:

GeneralSecurityException - creating a cipher failed

IOException - creating a cipher failed