gnu.javax.crypto.key.dh

Class GnuDHPublicKey

Implemented Interfaces:
DHKey, DHPublicKey, Key, PublicKey, Serializable

public class GnuDHPublicKey
extends GnuDHKey
implements DHPublicKey

An implementation of the Diffie-Hellman public key.

Reference:

  1. Diffie-Hellman Key Agreement Method
    Eric Rescorla.

Field Summary

Fields inherited from class gnu.javax.crypto.key.dh.GnuDHKey

defaultFormat, g, p, q

Fields inherited from interface javax.crypto.interfaces.DHPublicKey

serialVersionUID

Fields inherited from interface java.security.Key

serialVersionUID

Fields inherited from interface java.security.PublicKey

serialVersionUID

Constructor Summary

GnuDHPublicKey(int preferredFormat, BigInteger q, BigInteger p, BigInteger g, BigInteger y)
Constructs a new instance of GnuDHPublicKey given the designated parameters.
GnuDHPublicKey(BigInteger q, BigInteger p, BigInteger g, BigInteger y)
Convenience constructor.

Method Summary

boolean
equals(Object obj)
Returns true if the designated object is an instance of DHPublicKey and has the same parameter values as this one.
byte[]
getEncoded(int format)
Returns the encoded form of this public key according to the designated format.
BigInteger
getY()
String
toString()
Convert this Object to a human-readable String.
static GnuDHPublicKey
valueOf(byte[] k)
A class method that takes the output of the encodePublicKey() method of a DH keypair codec object (an instance implementing IKeyPairCodec for DSS keys, and re-constructs an instance of this object.

Methods inherited from class gnu.javax.crypto.key.dh.GnuDHKey

equals, getAlgorithm, getEncoded, getEncoded, getFormat, getParams, getQ, toString

Methods inherited from class java.lang.Object

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

Constructor Details

GnuDHPublicKey

public GnuDHPublicKey(int preferredFormat,
                      BigInteger q,
                      BigInteger p,
                      BigInteger g,
                      BigInteger y)
Constructs a new instance of GnuDHPublicKey given the designated parameters.
Parameters:
preferredFormat - the identifier of the encoding format to use by default when externalizing the key.
q - a prime divisor of p-1.
p - the public prime.
g - the generator of the group.
y - the public value y.

GnuDHPublicKey

public GnuDHPublicKey(BigInteger q,
                      BigInteger p,
                      BigInteger g,
                      BigInteger y)
Convenience constructor. Calls the constructor with five arguments passing Registry.RAW_ENCODING_ID as the value of its first argument.
Parameters:
q - a prime divisor of p-1.
p - the public prime.
g - the generator of the group.
y - the public value y.

Method Details

equals

public boolean equals(Object obj)
Returns true if the designated object is an instance of DHPublicKey and has the same parameter values as this one.
Overrides:
equals in interface GnuDHKey
Parameters:
obj - the other non-null DH key to compare to.
Returns:
true if the designated object is of the same type and value as this one.

getEncoded

public byte[] getEncoded(int format)
Returns the encoded form of this public key according to the designated format.
Overrides:
getEncoded in interface GnuDHKey
Parameters:
format - the desired format identifier of the resulting encoding.
Returns:
the byte sequence encoding this key according to the designated format.
Throws:
IllegalArgumentException - if the format is not supported.

getY

public BigInteger getY()
Specified by:
getY in interface DHPublicKey

toString

public String toString()
Convert this Object to a human-readable String. There are no limits placed on how long this String should be or what it should contain. We suggest you make it as intuitive as possible to be able to place it into System.out.println() and such.

It is typical, but not required, to ensure that this method never completes abruptly with a RuntimeException.

This method will be called when performing string concatenation with this object. If the result is null, string concatenation will instead use "null".

The default implementation returns getClass().getName() + "@" + Integer.toHexString(hashCode()).

Overrides:
toString in interface GnuDHKey
Returns:
the String representing this Object, which may be null

valueOf

public static GnuDHPublicKey valueOf(byte[] k)
A class method that takes the output of the encodePublicKey() method of a DH keypair codec object (an instance implementing IKeyPairCodec for DSS keys, and re-constructs an instance of this object.
Parameters:
k - the contents of a previously encoded instance of this object.
Throws:
ArrayIndexOutOfBoundsException - if there is not enough bytes, in k, to represent a valid encoding of an instance of this object.
IllegalArgumentException - if the byte sequence does not represent a valid encoding of an instance of this object.

GnuDHPublicKey.java -- Copyright (C) 2003, 2006 Free Software Foundation, Inc. This file is a 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 of the License, 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; if not, write to the Free Software Foundation, Inc., 51 Franklin St, 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.