userDatabase
Class User

java.lang.Object
  userDatabase.User

public final class User
extends java.lang.Object

Data structure used to store user-specific data (for example identifiers, session keys or buffers).

Author:

Karl-Peter Fuchs

Constructor Summary

User(int identifier)
Creates a new User using the bypassed identifier.

Method Summary

int	availableDataInProxyReadBuffer() Returns the number of bytes currently available in proxyReadBuffer, which contains data received from proxy server for this User.
int	availableDataInProxyWriteBuffer() Returns the number of bytes currently available in proxyWriteBuffer, which contains data that shall be sent to the proxy server.
java.nio.ByteBuffer	getClientReadBuffer() Returns this User's ByteBuffer used for caching fragments of a message received from the corresponding Client.
java.nio.ByteBuffer	getClientWriteBuffer() Returns this User's ByteBuffer used for caching messages that shall be sent to the corresponding Client.
javax.crypto.Cipher	getDecryptCipher() Returns this User's decryptCipher, used to decrypt Requests.
javax.crypto.Cipher	getEncryptCipher() Returns this User's encryptCipher, used to encrypt Replyies.
byte[]	getFromProxyReadBuffer(int limit) Used to read data from proxyReadBuffer, which contains data received from proxy server for this User.
byte[]	getFromProxyWriteBuffer(int limit) Used to read data from proxyWriteBuffer, which contains data that shall be sent to the proxy server.
boolean	getHasMessageInCurrentBatch() Returns whether a Request of this User is already in batch or not (used to prevent flooding attacks).
boolean	getHasMessageInCurrentReplyBatch() Returns whether a Reply of this User is already in batch or not (used to prevent flooding attacks).
java.lang.Integer	getIdentifier() Returns this Users (local) identifier (used to distinguish between Users).
java.lang.Integer	getIdentifierForNextMix() Returns this User's identifier, used by the next mix of the cascade (used to distinguish between Users).
boolean	getIsChannelEstablished() Returns whether a channel (used to transmit ChannelMessages) has been establish for/by this User or not.
javax.crypto.SecretKey	getMacKey() Returns the SecretKey, used for validating message authentication codes by this User.
java.nio.channels.SocketChannel	getSocketChannel() Returns this User's SocketChannel.
long	getTimestampOfLastActivity() Returns a timestamp of this User's last activity.
void	initializeClientBuffers(java.nio.channels.SocketChannel socketChannel) Allocates space for the buffers used to communicate with this User's corresponding Client (needed for non-blocking I/O).
void	initializeProxyBuffers() Allocates space for the buffers used to communicate with this User's corresponding proxy server (needed for non-blocking I/O).
boolean	isStillValid(long timeout) Indicates whether this User's last activity took place during the last timeout ms or not (used to detect outdated Users).
void	putInProxyReadBuffer(byte[] data) Used to add data received from proxy server for this User.
void	putInProxyWriteBuffer(byte[] data) Used to add data, that shall be sent to proxy server.
void	setDecryptCipher(javax.crypto.Cipher decryptCipher) Makes this User use the bypassed Cipher for decrypting Requests
void	setEncryptCipher(javax.crypto.Cipher encryptCipher) Makes this User use the bypassed Cipher for encrypting Replyies.
void	setHasMessageInCurrentBatch(boolean newValue) Used to indicate, whether a Request of this User is already in batch or not (used to prevent flooding attacks).
void	setHasMessageInCurrentReplyBatch(boolean newValue) Used to indicate, whether a Reply for this User is already in batch or not (used to prevent flooding attacks).
void	setIsChannelEstablished(boolean newValue) Sets variable isChannelEstablished to the bypassed value (indicates whether a channel (used to transmit ChannelMessages) has been establish for/by this User or not).
void	setMacKey(javax.crypto.SecretKey newMacKey) Makes this User use the bypassed SecretKey for validating message authentication codes.
void	setTimestampOfLastActivity() Must be called when User sends a Message (Used to detect inactive Users).
java.lang.String	toString() Returns a simple String representation of this class.

Methods inherited from class java.lang.Object

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

Constructor Detail

User

public User(int identifier)

Creates a new User using the bypassed identifier.

Parameters:

identifier - A (local) identifier for this User used to distinguish between Users.

Method Detail

getIdentifier

public java.lang.Integer getIdentifier()

Returns this Users (local) identifier (used to distinguish between Users).

Returns:

This Users (local) identifier.

getIdentifierForNextMix

public java.lang.Integer getIdentifierForNextMix()

Returns this User's identifier, used by the next mix of the cascade (used to distinguish between Users). Note: Different identifiers must be used to prevent linkability.

Returns:

This Users identifier, used by the next mix of the cascade

getIsChannelEstablished

public boolean getIsChannelEstablished()

Returns whether a channel (used to transmit ChannelMessages) has been establish for/by this User or not.

Returns:

Whether a channel (used to transmit ChannelMessages) has been establish for/by this User or not.

setIsChannelEstablished

public void setIsChannelEstablished(boolean newValue)

Sets variable isChannelEstablished to the bypassed value (indicates whether a channel (used to transmit ChannelMessages) has been establish for/by this User or not).

Parameters:

newValue - Value isChannelEstablished variable shall be set to.

isStillValid

public boolean isStillValid(long timeout)

Indicates whether this User's last activity took place during the last timeout ms or not (used to detect outdated Users).

Parameters:

timeout - Period of time to be taken in account.

Returns:

Whether this User's last activity took place during the last timeout ms or not.

getTimestampOfLastActivity

public long getTimestampOfLastActivity()

Returns a timestamp of this User's last activity.

Returns:

Timestamp for this User's last activity.

setTimestampOfLastActivity

public void setTimestampOfLastActivity()

Must be called when User sends a Message (Used to detect inactive Users).

getEncryptCipher

public javax.crypto.Cipher getEncryptCipher()

Returns this User's encryptCipher, used to encrypt Replyies.

Returns:

This User's encryptCipher, used to encrypt Replyies.

setEncryptCipher

public void setEncryptCipher(javax.crypto.Cipher encryptCipher)

Makes this User use the bypassed Cipher for encrypting Replyies.

Parameters:

encryptCipher - Cipher, that shall be used for encrypting Replyies.

getDecryptCipher

public javax.crypto.Cipher getDecryptCipher()

Returns this User's decryptCipher, used to decrypt Requests.

Returns:

This User's decryptCipher, used to decrypt Requests.

setDecryptCipher

public void setDecryptCipher(javax.crypto.Cipher decryptCipher)

Makes this User use the bypassed Cipher for decrypting Requests

Parameters:

decryptCipher - Cipher, that shall be used for decrypting Requests

getMacKey

public javax.crypto.SecretKey getMacKey()

Returns the SecretKey, used for validating message authentication codes by this User.

Returns:

SecretKey, used for validating message authentication codes by this User.

setMacKey

public void setMacKey(javax.crypto.SecretKey newMacKey)

Makes this User use the bypassed SecretKey for validating message authentication codes.

Parameters:

newMacKey - SecretKey, that shall be used for validating message authentication codes.

getHasMessageInCurrentBatch

public boolean getHasMessageInCurrentBatch()

Returns whether a Request of this User is already in batch or not (used to prevent flooding attacks).

Returns:

Whether a Request of this User is already in batch or not (used to prevent flooding attacks).

setHasMessageInCurrentBatch

public void setHasMessageInCurrentBatch(boolean newValue)

Used to indicate, whether a Request of this User is already in batch or not (used to prevent flooding attacks).

Parameters:

newValue - Whether a Request of this User is already in batch or not.

getHasMessageInCurrentReplyBatch

public boolean getHasMessageInCurrentReplyBatch()

Returns whether a Reply of this User is already in batch or not (used to prevent flooding attacks).

Returns:

Whether a Reply of this User is already in batch or not (used to prevent flooding attacks).

setHasMessageInCurrentReplyBatch

public void setHasMessageInCurrentReplyBatch(boolean newValue)

Used to indicate, whether a Reply for this User is already in batch or not (used to prevent flooding attacks).

Parameters:

newValue - Whether a Reply for this User is already in batch or not.

getClientReadBuffer

public java.nio.ByteBuffer getClientReadBuffer()

Returns this User's ByteBuffer used for caching fragments of a message received from the corresponding Client. Needed for non-blocking I/O.

Returns:

This User's ByteBuffer used for caching fragments of a message received from the corresponding Client.

getClientWriteBuffer

public java.nio.ByteBuffer getClientWriteBuffer()

Returns this User's ByteBuffer used for caching messages that shall be sent to the corresponding Client. Needed for non-blocking I/O.

Returns:

This User's ByteBuffer used for caching messages that shall be sent to the corresponding Client.

getSocketChannel

public java.nio.channels.SocketChannel getSocketChannel()

Returns this User's SocketChannel. Needed for non-blocking I/O.

Returns:

This User's SocketChannel.

putInProxyReadBuffer

public void putInProxyReadBuffer(byte[] data)

Used to add data received from proxy server for this User. Puts the bypassed data in this User's proxyReadBuffer, from where it will be taken to generate Replyies.

Blocks until all data is written.

Parameters:

data - Data for this User, received from proxy server.

getFromProxyReadBuffer

public byte[] getFromProxyReadBuffer(int limit)

Used to read data from proxyReadBuffer, which contains data received from proxy server for this User.

Reads as much bytes as available (until limit).

Parameters:

limit - Maximum number of bytes to be returned.

Returns:

The requested data.

availableDataInProxyReadBuffer

public int availableDataInProxyReadBuffer()

Returns the number of bytes currently available in proxyReadBuffer, which contains data received from proxy server for this User.

Assures that AT LEAST @return bytes can be read from proxyReadBuffer until next call of getFromProxyReadBuffer(int).

Returns:

Number of bytes currently available in proxyReadBuffer

putInProxyWriteBuffer

public void putInProxyWriteBuffer(byte[] data)

Used to add data, that shall be sent to proxy server. Puts the bypassed data in this User's proxyWriteBuffer, from where it will be sent to the corresponding proxy server.

Blocks until all data is written.

Parameters:

data - Data, that shall be sent to proxy server.

getFromProxyWriteBuffer

public byte[] getFromProxyWriteBuffer(int limit)

Used to read data from proxyWriteBuffer, which contains data that shall be sent to the proxy server.

Reads as much bytes as available (until limit).

Parameters:

limit - Maximum number of bytes to be returned.

Returns:

The requested data.

availableDataInProxyWriteBuffer

public int availableDataInProxyWriteBuffer()

Returns the number of bytes currently available in proxyWriteBuffer, which contains data that shall be sent to the proxy server.

Assures that AT LEAST @return bytes can be read from proxyWriteBuffer until next call of getFromProxyWriteBuffer(int).

Returns:

Number of bytes currently available in proxyWriteBuffer

initializeClientBuffers

public void initializeClientBuffers(java.nio.channels.SocketChannel socketChannel)

Allocates space for the buffers used to communicate with this User's corresponding Client (needed for non-blocking I/O).

Used by first mix of cascade only.

Parameters:

socketChannel - SocketChannel to read/write data from/to.

initializeProxyBuffers

public void initializeProxyBuffers()

Allocates space for the buffers used to communicate with this User's corresponding proxy server (needed for non-blocking I/O).

Used by last mix of cascade only.

toString

public java.lang.String toString()

Returns a simple String representation of this class.

Overrides:

toString in class java.lang.Object

Returns:

A simple String representation of this class.