package gnu.crypto.key.dss;
// ----------------------------------------------------------------------------
// $Id: DSSKey.java,v 1.2 2005/10/06 04:24:16 rsdio Exp $
//
// Copyright (C) 2001, 2002, 2003 Free Software Foundation, Inc.
//
// This file is part of GNU Crypto.
//
// GNU Crypto 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 Crypto 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 this program; 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.
//
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// you permission to link this library with independent modules to
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// do so, delete this exception statement from your version.
// ----------------------------------------------------------------------------
import gnu.crypto.Registry;
import gnu.crypto.key.IKeyPairCodec;
import java.math.BigInteger;
import java.security.Key;
import java.security.interfaces.DSAKey;
import java.security.interfaces.DSAParams;
import java.security.spec.DSAParameterSpec;
/**
* <p>A base asbtract class for both public and private DSS (Digital Signature
* Standard) keys. It encapsulates the three DSS numbers: <code>p</code>,
* <code>q</code> and <code>g</code>.</p>
*
* <p>According to the JDK, cryptographic <i>Keys</i> all have a <i>format</i>.
* The format used in this implementation is called <i>Raw</i>, and basically
* consists of the raw byte sequences of algorithm parameters. The exact order
* of the byte sequences and the implementation details are given in each of
* the relevant <code>getEncoded()</code> methods of each of the private and
* public keys.</p>
*
* @version $Revision: 1.2 $
* @see DSSPrivateKey#getEncoded
* @see DSSPublicKey#getEncoded
*/
public abstract class DSSKey implements Key, DSAKey {
// Constants and variables
// -------------------------------------------------------------------------
/**
* A prime modulus, where <code>2<sup>L-1</sup> < p < 2<sup>L</sup></code>
* for <code>512 <= L <= 1024</code> and <code>L</code> a multiple of
* <code>64</code>.
*/
protected final BigInteger p;
/**
* A prime divisor of <code>p - 1</code>, where <code>2<sup>159</sup> < q
* < 2<sup>160</sup></code>.
*/
protected final BigInteger q;
/**
* <code>g = h<sup>(p-1)</sup>/q mod p</code>, where <code>h</code> is any
* integer with <code>1 < h < p - 1</code> such that <code>h<sup>
* (p-1)</sup>/q mod p > 1</code> (<code>g</code> has order <code>q mod p
* </code>).
*/
protected final BigInteger g;
// Constructor(s)
// -------------------------------------------------------------------------
/**
* <p>Trivial protected constructor.</p>
*
* @param p the DSS parameter <code>p</code>.
* @param q the DSS parameter <code>q</code>.
* @param g the DSS parameter <code>g</code>.
*/
protected DSSKey(BigInteger p, BigInteger q, BigInteger g) {
super();
this.p = p;
this.q = q;
this.g = g;
}
// Class methods
// -------------------------------------------------------------------------
// Instance methods
// -------------------------------------------------------------------------
// java.security.interfaces.DSAKey interface implementation ----------------
public DSAParams getParams() {
return new DSAParameterSpec(p, q, g);
}
// java.security.Key interface implementation ------------------------------
public String getAlgorithm() {
return Registry.DSS_KPG;
}
/** @deprecated see getEncoded(int). */
public byte[] getEncoded() {
return getEncoded(IKeyPairCodec.RAW_FORMAT);
}
public String getFormat() {
return null;
}
// Other instance methods --------------------------------------------------
/**
* <p>Returns <code>true</code> if the designated object is an instance of
* {@link DSAKey} and has the same DSS (Digital Signature Standard) parameter
* values as this one.</p>
*
* @param obj the other non-null DSS key to compare to.
* @return <code>true</code> if the designated object is of the same type and
* value as this one.
*/
public boolean equals(Object obj) {
if (obj == null) {
return false;
}
if (!(obj instanceof DSAKey)) {
return false;
}
DSAKey that = (DSAKey) obj;
return p.equals(that.getParams().getP())
&& q.equals(that.getParams().getQ())
&& g.equals(that.getParams().getG());
}
// abstract methods to be implemented by subclasses ------------------------
public abstract byte[] getEncoded(int format);
}