com.jcorporate.expresso.core.security.strongencryption
Class StringEncryption

java.lang.Object
  com.jcorporate.expresso.core.security.AbstractStringEncryption
      com.jcorporate.expresso.core.security.strongencryption.StringEncryption

public class StringEncryption

extends AbstractStringEncryption

StringEncryption.java

Copyright 2000, 2001 Jcorporate Ltd.

This class provides basic string encryption. It'll provide the services of password whitening and automatic selection of encryption.

Known Vulnerabilities. The actual whitened password remains in memory for performance sake. An attacker may find the actual password by looking at swap files looking for Base64 encoded strings. (Not too hard to grep out) but it requires an attacker to gain access to the swap partition of the server. Do not use this class for a personal encryption program.

Byte Array Format Information:

An encrypted string has the following format:

Byte 0: File Version Number(whole number only)

Bytes 1-6: 3 character desgination for the encryption mode used. UTF-16 BE

Bytes 7-14/22: The 8/16 byte random input vector to the encrypted system.

Bytes 15+/23++ : The Actual Encrypted Data

Author:

Michael Rimov

Field Summary

protected static ByteArrayCounter	ivCounter128
protected static ByteArrayCounter	ivCounter64

Constructor Summary

StringEncryption()
class for encapsulating encryption.

Method Summary

byte[]	decrypt(byte[] inputData) Same as decryptString, but only deals in byte arrays.
void	destroy() Unregisters the cryptographic handler
byte[]	encrypt(byte[] inputData) Same as encryptString, but only deals in byte arrays.
byte[]	encrypt(byte[] inputData, String theShortCipherString) Encrypts a byte array of data based upon the method desired.
void	init()

Methods inherited from class com.jcorporate.expresso.core.security.AbstractStringEncryption

decryptString, encryptString, getCryptoManager, getPreparedPassKey, preparePassKey, setCryptoManager

Methods inherited from class java.lang.Object

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

Field Detail

ivCounter64

protected static ByteArrayCounter ivCounter64

ivCounter128

protected static ByteArrayCounter ivCounter128

Constructor Detail

StringEncryption

public StringEncryption()

class for encapsulating encryption. constructor will throw if JCE jar is not found; see Ant target 'get-crypto' for easy means to download appropriate crypto library. it is under export restriction, so it cannot be added to the expresso library as publicly distributed

Method Detail

init

public void init()
          throws ChainedException

Overrides:

init in class AbstractStringEncryption

Throws:

ChainedException

destroy

public void destroy()

Unregisters the cryptographic handler

Overrides:

destroy in class AbstractStringEncryption

decrypt

public byte[] decrypt(byte[] inputData)
               throws ChainedException

Same as decryptString, but only deals in byte arrays. This method must be implemented by descendants of this class.

Specified by:

decrypt in class AbstractStringEncryption

Parameters:

inputData - The input data to decrypt

Returns:

the decrypted data byte

Throws:

ChainedException - Upn encryption error

encrypt

public byte[] encrypt(byte[] inputData,
                      String theShortCipherString)
               throws ChainedException

Encrypts a byte array of data based upon the method desired. See the main notes for this class for valid encryptMethod strings.

Note that a similar decrypt is not needed because the encryptMethod is included in the header of the encrypted byte array.

Parameters:

inputData - The data to encrypt

theShortCipherString - The 'short name' of the cipher to use

Returns:

The encrypted byte array

Throws:

ChainedException - Upon error encrypting

encrypt

public byte[] encrypt(byte[] inputData)
               throws ChainedException

Same as encryptString, but only deals in byte arrays. This must be implemented by the descendants of this class.

Specified by:

encrypt in class AbstractStringEncryption

Parameters:

inputData - The data to encrypt

Returns:

The encrypted byte array.

Throws:

ChainedException