gnu.javax.crypto.jce

Class DiffieHellmanImpl


public final class DiffieHellmanImpl
extends KeyAgreementSpi

The JCE implementation of a 2-party Diffie-Hellman key agreement.

Constructor Summary

DiffieHellmanImpl()
Trivial default constructor.

Method Summary

protected Key
engineDoPhase(Key incoming, boolean lastPhase)
Do a phase in the key agreement.
protected byte[]
engineGenerateSecret()
Generate the shared secret in a new byte array.
protected int
engineGenerateSecret(byte[] secret, int offset)
Generate the shared secret, storing it into the specified array.
protected SecretKey
engineGenerateSecret(String algorithm)
Generate the shared secret and return it as a SecretKey.
protected void
engineInit(Key key, SecureRandom random)
Initialize this key agreement with a key and source of randomness.
protected void
engineInit(Key key, AlgorithmParameterSpec params, SecureRandom random)
Initialize this key agreement with a key, parameters, and source of randomness.

Methods inherited from class javax.crypto.KeyAgreementSpi

engineDoPhase, engineGenerateSecret, engineGenerateSecret, engineGenerateSecret, engineInit, engineInit

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

DiffieHellmanImpl

public DiffieHellmanImpl()
Trivial default constructor.

Method Details

engineDoPhase

protected Key engineDoPhase(Key incoming,
                            boolean lastPhase)
            throws InvalidKeyException
Do a phase in the key agreement.
Overrides:
engineDoPhase in interface KeyAgreementSpi
Parameters:
lastPhase - true if this call should be the last phase.
Returns:
The intermediate result, or null if there is no intermediate result.
Throws:
IllegalStateException - If this instance has not been initialized.
InvalidKeyException - If the supplied key is not appropriate.

engineGenerateSecret

protected byte[] engineGenerateSecret()
Generate the shared secret in a new byte array.
Overrides:
engineGenerateSecret in interface KeyAgreementSpi
Returns:
The shared secret in a new byte array.
Throws:
IllegalStateException - If this key agreement is not ready to generate the secret.

engineGenerateSecret

protected int engineGenerateSecret(byte[] secret,
                                   int offset)
            throws ShortBufferException
Generate the shared secret, storing it into the specified array.
Overrides:
engineGenerateSecret in interface KeyAgreementSpi
Parameters:
offset - The offset into the byte array to start.
Returns:
The size of the shared secret.
Throws:
IllegalStateException - If this key agreement is not ready to generate the secret.
ShortBufferException - If there is not enough space in the supplied array for the shared secret.

engineGenerateSecret

protected SecretKey engineGenerateSecret(String algorithm)
            throws InvalidKeyException
Generate the shared secret and return it as a SecretKey.
Overrides:
engineGenerateSecret in interface KeyAgreementSpi
Parameters:
algorithm - The algorithm with which to generate the secret key.
Returns:
The shared secret as a secret key.
Throws:
IllegalStateException - If this key agreement is not ready to generate the secret.
InvalidKeyException - If the shared secret cannot be made into a SecretKey.

engineInit

protected void engineInit(Key key,
                          SecureRandom random)
            throws InvalidKeyException
Initialize this key agreement with a key and source of randomness.
Overrides:
engineInit in interface KeyAgreementSpi
Parameters:
key - The key to initialize with, usually a private key.
random - The source of randomness to use.
Throws:
InvalidKeyException - If the supplied key is inappropriate.

engineInit

protected void engineInit(Key key,
                          AlgorithmParameterSpec params,
                          SecureRandom random)
            throws InvalidKeyException
Initialize this key agreement with a key, parameters, and source of randomness.
Overrides:
engineInit in interface KeyAgreementSpi
Parameters:
key - The key to initialize with, usually a private key.
params - The parameters to initialize with.
random - The source of randomness to use.
Throws:
InvalidKeyException - If the supplied key is inappropriate.

DiffieHellmanImpl.java -- implementation of the Diffie-Hellman key agreement. Copyright (C) 2005, 2006 Free Software Foundation, Inc. This file is part of GNU Classpath. GNU Classpath is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. GNU Classpath is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with GNU Classpath; see the file COPYING. If not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. Linking this library statically or dynamically with other modules is making a combined work based on this library. Thus, the terms and conditions of the GNU General Public License cover the whole combination. As a special exception, the copyright holders of this library give you permission to link this library with independent modules to produce an executable, regardless of the license terms of these independent modules, and to copy and distribute the resulting executable under terms of your choice, provided that you also meet, for each linked independent module, the terms and conditions of the license of that module. An independent module is a module which is not derived from or based on this library. If you modify this library, you may extend this exception to your version of the library, but you are not obligated to do so. If you do not wish to do so, delete this exception statement from your version.