package gnu.crypto.key;
// ----------------------------------------------------------------------------
// $Id: KeyPairCodecFactory.java,v 1.2 2005/10/06 04:24:16 rsdio Exp $
//
// Copyright (C) 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.
//
// 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.
// ----------------------------------------------------------------------------
import gnu.crypto.Registry;
import gnu.crypto.key.dh.DHKeyPairRawCodec;
import gnu.crypto.key.dh.GnuDHPrivateKey;
import gnu.crypto.key.dh.GnuDHPublicKey;
import gnu.crypto.key.dss.DSSKeyPairRawCodec;
import gnu.crypto.key.dss.DSSPrivateKey;
import gnu.crypto.key.dss.DSSPublicKey;
import gnu.crypto.key.rsa.GnuRSAPrivateKey;
import gnu.crypto.key.rsa.GnuRSAPublicKey;
import gnu.crypto.key.rsa.RSAKeyPairRawCodec;
import gnu.crypto.key.srp6.SRPKeyPairRawCodec;
import gnu.crypto.key.srp6.SRPPrivateKey;
import gnu.crypto.key.srp6.SRPPublicKey;
import java.util.Set;
import java.security.Key;
import java.security.PrivateKey;
import java.security.PublicKey;
/**
* <p>A <i>Factory</i> class to instantiate key encoder/decoder instances.</p>
*
* @version $Revision: 1.2 $
*/
public class KeyPairCodecFactory {
// Constants and variables
// -------------------------------------------------------------------------
// Constructor(s)
// -------------------------------------------------------------------------
/** Trivial constructor to enforce Singleton pattern. */
private KeyPairCodecFactory() {
super();
}
// Class methods
// -------------------------------------------------------------------------
/**
* <p>Returns an instance of a keypair codec given its name.</p>
*
* @param name the case-insensitive key codec name.
* @return an instance of the keypair codec, or <code>null</code> if none
* found.
*/
public static IKeyPairCodec getInstance(String name) {
if (name == null) {
return null;
}
name = name.trim();
IKeyPairCodec result = null;
if (name.equalsIgnoreCase(Registry.DSA_KPG) || name.equals(Registry.DSS_KPG)) {
result = new DSSKeyPairRawCodec();
} else if (name.equalsIgnoreCase(Registry.RSA_KPG)) {
result = new RSAKeyPairRawCodec();
} else if (name.equalsIgnoreCase(Registry.DH_KPG)) {
result = new DHKeyPairRawCodec();
} else if (name.equalsIgnoreCase(Registry.SRP_KPG)) {
result = new SRPKeyPairRawCodec();
}
return result;
}
/**
* <p>Returns an instance of a keypair codec given a byte array that is
* assumed to contain a previously encoded key (public or private).</p>
*
* @param buffer a byte array containing a previously encoded key.
* @return an instance of the keypair codec, or <code>null</code> if none
* found.
*/
public static IKeyPairCodec getInstance(byte[] buffer) {
if (buffer == null) {
return null;
}
// our codecs prefix the stream with a 4-byte magic
if (buffer.length < 5) {
return null;
}
// the first byte is always 0x47
if (buffer[0] != 0x47) {
return null;
}
// so far we only have RAW codecs
if (buffer[1] != Registry.RAW_ENCODING_ID) {
return null;
}
IKeyPairCodec result = null;
switch (buffer[2]) {
case 0x44: result = new DSSKeyPairRawCodec(); break;
case 0x52: result = new RSAKeyPairRawCodec(); break;
case 0x48: result = new DHKeyPairRawCodec(); break;
case 0x53: result = new SRPKeyPairRawCodec(); break;
}
return result;
}
/**
* <p>Returns an instance of a keypair codec given a key.</p>
*
* @param key the key to encode.
* @return an instance of the keypair codec, or <code>null</code> if none
* found.
*/
public static IKeyPairCodec getInstance(Key key) {
if (key == null) {
return null;
}
IKeyPairCodec result = null;
if (key instanceof PublicKey) {
if (key instanceof DSSPublicKey) {
result = new DSSKeyPairRawCodec();
} else if (key instanceof GnuRSAPublicKey) {
result = new RSAKeyPairRawCodec();
} else if (key instanceof GnuDHPublicKey) {
result = new DHKeyPairRawCodec();
} else if (key instanceof SRPPublicKey) {
result = new SRPKeyPairRawCodec();
}
} else if (key instanceof PrivateKey) {
if (key instanceof DSSPrivateKey) {
result = new DSSKeyPairRawCodec();
} else if (key instanceof GnuRSAPrivateKey) {
result = new RSAKeyPairRawCodec();
} else if (key instanceof GnuDHPrivateKey) {
result = new DHKeyPairRawCodec();
} else if (key instanceof SRPPrivateKey) {
result = new SRPKeyPairRawCodec();
}
}
return result;
}
/**
* <p>Returns a {@link Set} of keypair codec names supported by this
* <i>Factory</i>.</p>
*
* @return a {@link Set} of keypair codec names (Strings).
*/
public static final Set getNames() {
return KeyPairGeneratorFactory.getNames();
}
}