gnu.crypto.key
Class BaseKeyAgreementParty

java.lang.Object
  gnu.crypto.key.BaseKeyAgreementParty

All Implemented Interfaces:

IKeyAgreementParty

Direct Known Subclasses:

DiffieHellmanKeyAgreement, ElGamalKeyAgreement, SRP6KeyAgreement

public abstract class BaseKeyAgreementParty

extends java.lang.Object

implements IKeyAgreementParty

A base abstract class to facilitate implementations of concrete key agreement protocol handlers.

Version:

$Revision: 1.2 $

Field Summary

protected boolean	complete Whether the exchange has concluded or not.
protected boolean	initialised Whether the instance is initialised or not.
protected java.lang.String	name The canonical name of the protocol.
protected java.security.SecureRandom	rnd The optional SecureRandom instance to use.
protected int	step The current step index of the protocol exchange.
protected static java.math.BigInteger	TWO

Constructor Summary

protected

BaseKeyAgreementParty(java.lang.String name)

Method Summary

protected abstract void	engineInit(java.util.Map attributes)
protected abstract OutgoingMessage	engineProcessMessage(IncomingMessage in)
protected abstract void	engineReset()
protected abstract byte[]	engineSharedSecret()
byte[]	getSharedSecret() Returns the byte array containing the shared secret as generated by this party.
void	init(java.util.Map attributes) Sets up the instance to operate with specific attributes.
boolean	isComplete() Returns true if the party in the key agreement protocol exchange has completed its part of the exchange.
java.lang.String	name() Returns the canonical name of the key agreement protocol.
protected void	nextRandomBytes(byte[] buffer) Fills the designated byte array with random data.
OutgoingMessage	processMessage(IncomingMessage in) Processes an incoming message at one end, generating a message that will be processed by the other party(ies).
void	reset() Resets this instance for re-use with another set of attributes.

Methods inherited from class java.lang.Object

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

Field Detail

TWO

protected static final java.math.BigInteger TWO

name

protected java.lang.String name

The canonical name of the protocol.

initialised

protected boolean initialised

Whether the instance is initialised or not.

step

protected int step

The current step index of the protocol exchange.

complete

protected boolean complete

Whether the exchange has concluded or not.

rnd

protected java.security.SecureRandom rnd

The optional SecureRandom instance to use.

Constructor Detail

BaseKeyAgreementParty

protected BaseKeyAgreementParty(java.lang.String name)

Method Detail

name

public java.lang.String name()

Description copied from interface: IKeyAgreementParty

Returns the canonical name of the key agreement protocol.

Specified by:

name in interface IKeyAgreementParty

Returns:

the canonical name of the key agreement protocol.

init

public void init(java.util.Map attributes)
          throws KeyAgreementException

Description copied from interface: IKeyAgreementParty

Sets up the instance to operate with specific attributes.

Specified by:

init in interface IKeyAgreementParty

Parameters:

attributes - a map of name-values used by concrete implementations.

Throws:

KeyAgreementException - if an exception occurs during the setup.

processMessage

public OutgoingMessage processMessage(IncomingMessage in)
                               throws KeyAgreementException

Description copied from interface: IKeyAgreementParty

Processes an incoming message at one end, generating a message that will be processed by the other party(ies).

Specified by:

processMessage in interface IKeyAgreementParty

Parameters:

in - the incoming message.

Returns:

an outgoing message, or null if this is an intermediary step that does not cause any output.

Throws:

KeyAgreementException - if an exception occurs during the processing of the incoming message, or during the generation of the outgoing message.

isComplete

public boolean isComplete()

Description copied from interface: IKeyAgreementParty

Returns true if the party in the key agreement protocol exchange has completed its part of the exchange. If this is the case an IllegalStateException is thrown for any method invocation except init() or reset().

Specified by:

isComplete in interface IKeyAgreementParty

Returns:

true if this party has completed its part of the key agreement protocol exchange; false otherwise.

getSharedSecret

public byte[] getSharedSecret()
                       throws KeyAgreementException

Description copied from interface: IKeyAgreementParty

Returns the byte array containing the shared secret as generated by this party.

Specified by:

getSharedSecret in interface IKeyAgreementParty

Returns:

the generated shared secret.

Throws:

KeyAgreementException - if the key agreement is not yet initialised, or is initialised but the exchange is still in progress.

reset

public void reset()

Description copied from interface: IKeyAgreementParty

Resets this instance for re-use with another set of attributes.

Specified by:

reset in interface IKeyAgreementParty

engineInit

protected abstract void engineInit(java.util.Map attributes)
                            throws KeyAgreementException

Throws:

KeyAgreementException

engineProcessMessage

protected abstract OutgoingMessage engineProcessMessage(IncomingMessage in)
                                                 throws KeyAgreementException

Throws:

KeyAgreementException

engineSharedSecret

protected abstract byte[] engineSharedSecret()
                                      throws KeyAgreementException

Throws:

KeyAgreementException

engineReset

protected abstract void engineReset()

nextRandomBytes

protected void nextRandomBytes(byte[] buffer)

Fills the designated byte array with random data.

Parameters:

buffer - the byte array to fill with random data.