client
Class Cryptography

java.lang.Object
  client.Cryptography

final class Cryptography
extends java.lang.Object

Provides methods for de- and encrypting messages.

Author:

Karl-Peter Fuchs

Field Summary

private javax.crypto.Cipher	asymmetricCipher Cipher for asymmetric cryptography.
private static InternalInformationPortController	internalInformationPort Reference on component InternalInformationPortController.
private javax.crypto.KeyGenerator	keyGenerator Key generator for symmetric cryptography and hash algorithm.
private static java.util.logging.Logger	LOGGER Logger used to log and display information.
private int	NUMBER_OF_MIXES_IN_CASCADE Number of mixes in the cascade.
private java.security.Key[]	PUBLIC_KEYS_OF_MIXES Public keys of the cascade's mixes.
private javax.crypto.spec.IvParameterSpec[]	sessionIVs Initialization vectors for the ciphers for each of the cascade's mixes.
private javax.crypto.SecretKey[]	sessionKeys Session keys for the cascade's mixes.
private javax.crypto.Cipher[]	symmetricDecryptCiphers Session (decrypt) ciphers for each of the cascade's mixes.
private javax.crypto.Cipher[]	symmetricEncryptCiphers Session (encrypt) ciphers for each of the cascade's mixes.

Constructor Summary

protected

Cryptography(java.security.Key[] publicKeysOfMixes) Generates a new Cryptography object that can be used to de- and encrypting messages (using the bypassed keys).

Method Summary

protected byte[]	decryptReply(byte[] reply) Decrypts the bypassed reply.
protected Message	encryptMessage(Message plaintextMessage, int positionOfMixInCascade) Encrypts the bypassed message (hybridly) for the specified mix.
private static java.lang.String	getProperty(java.lang.String key) Simply used to shorten method calls (calls internalInformationPort.getProperty(key)).
protected javax.crypto.spec.IvParameterSpec	getSessionIVOfMix(int positionOfMixInCascade) Returns the specified mix' initialization vector.
protected javax.crypto.SecretKey	getSessionKeyOfMix(int positionOfMixInCascade) Returns the specified mix' session key.

Methods inherited from class java.lang.Object

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

Field Detail

internalInformationPort

private static InternalInformationPortController internalInformationPort

Reference on component InternalInformationPortController. Used to display and/or log data and read general settings.

LOGGER

private static final java.util.logging.Logger LOGGER

Logger used to log and display information.

NUMBER_OF_MIXES_IN_CASCADE

private final int NUMBER_OF_MIXES_IN_CASCADE

Number of mixes in the cascade.

asymmetricCipher

private javax.crypto.Cipher asymmetricCipher

Cipher for asymmetric cryptography.

keyGenerator

private javax.crypto.KeyGenerator keyGenerator

Key generator for symmetric cryptography and hash algorithm.

PUBLIC_KEYS_OF_MIXES

private final java.security.Key[] PUBLIC_KEYS_OF_MIXES

Public keys of the cascade's mixes. The first mix' key is found at PUBLIC_KEYS_OF_MIXES[0].

sessionKeys

private javax.crypto.SecretKey[] sessionKeys

Session keys for the cascade's mixes. The key for the first mix is found at sessionKeys[0].

sessionIVs

private javax.crypto.spec.IvParameterSpec[] sessionIVs

Initialization vectors for the ciphers for each of the cascade's mixes. The initialization vector for the first mix is found at sessionIVs[0].

See Also:

symmetricEncryptCiphers, symmetricDecryptCiphers

symmetricEncryptCiphers

private javax.crypto.Cipher[] symmetricEncryptCiphers

Session (encrypt) ciphers for each of the cascade's mixes. The cipher for the first mix is found at symmetricEncryptCiphers[0].

symmetricDecryptCiphers

private javax.crypto.Cipher[] symmetricDecryptCiphers

Session (decrypt) ciphers for each of the cascade's mixes. The cipher for the first mix is found at symmetricEncryptCiphers[0].

Constructor Detail

Cryptography

protected Cryptography(java.security.Key[] publicKeysOfMixes)

Generates a new Cryptography object that can be used to de- and encrypting messages (using the bypassed keys).

Parameters:

publicKeysOfMixes - Public keys of the cascade's mixes. The first mix' key must be located at publicKeysOfMixes[0].

Method Detail

getSessionKeyOfMix

protected javax.crypto.SecretKey getSessionKeyOfMix(int positionOfMixInCascade)

Returns the specified mix' session key.

Parameters:

positionOfMixInCascade - The mix' position in the cascade, who's session key shall be returned.

Returns:

The specified mix' session key.

getSessionIVOfMix

protected javax.crypto.spec.IvParameterSpec getSessionIVOfMix(int positionOfMixInCascade)

Returns the specified mix' initialization vector.

Parameters:

positionOfMixInCascade - The mix' position in the cascade, who's initialization vector shall be returned.

Returns:

The specified mix' initialization vector.

encryptMessage

protected Message encryptMessage(Message plaintextMessage,
                                 int positionOfMixInCascade)

Encrypts the bypassed message (hybridly) for the specified mix.

Parameters:

positionOfMixInCascade - The mix' position in the cascade, the message shall be encrypted for.

plaintextMessage - The message to be encrypted.

Returns:

The (hybridly) encrypted message.

decryptReply

protected byte[] decryptReply(byte[] reply)

Decrypts the bypassed reply.

Parameters:

reply - The reply to be decrypted.

Returns:

The decrypted reply.

getProperty

private static java.lang.String getProperty(java.lang.String key)

Simply used to shorten method calls (calls internalInformationPort.getProperty(key)). Returns the property with the specified key from the property file.

Parameters:

key - The property key.

Returns:

The property with the specified key in the property file.