package gnu.crypto.mac;
// ----------------------------------------------------------------------------
// $Id: MacFactory.java,v 1.8 2005/10/06 04:24:16 rsdio Exp $
//
// Copyright (C) 2001, 2002, 2003, 2004 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.cipher.CipherFactory;
import gnu.crypto.cipher.IBlockCipher;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Set;
/**
* <p>A <i>Factory</i> that instantiates instances of every supported Message
* Authentication Code algorithms, including all <i>HMAC</i> algorithms.</p>
*
* @version $Revision: 1.8 $
*/
public class MacFactory implements Registry {
// Constants and variables
// -------------------------------------------------------------------------
// Constructor(s)
// -------------------------------------------------------------------------
/** Trivial constructor to enforce <i>Singleton</i> pattern. */
private MacFactory() {
super();
}
// Class methods
// -------------------------------------------------------------------------
/**
* <p>Returns an instance of a <i>MAC</i> algorithm given its name.</p>
*
* @param name the name of the MAC algorithm.
* @return an instance of the <i>MAC</i> algorithm, or <code>null</code> if
* none can be constructed.
* @exception InternalError if the implementation does not pass its self-test.
*/
public static IMac getInstance(String name) {
if (name == null) {
return null;
}
name = name.trim();
name = name.toLowerCase();
if (name.startsWith(HMAC_NAME_PREFIX)) {
return HMacFactory.getInstance(name);
}
if (name.startsWith(OMAC_PREFIX)) {
name = name.substring(OMAC_PREFIX.length());
IBlockCipher cipher = CipherFactory.getInstance(name);
if (cipher == null) {
return null;
}
return new OMAC(cipher);
}
IMac result = null;
if (name.equalsIgnoreCase(UHASH32)) {
result = new UHash32();
} else if (name.equalsIgnoreCase(UMAC32)) {
result = new UMac32();
} else if (name.equalsIgnoreCase(TMMH16)) {
result = new TMMH16();
}
// else if (name.equalsIgnoreCase(TMMH32)) {
// result = new TMMH32();
// }
if (result != null && !result.selfTest()) {
throw new InternalError(result.name());
}
return result;
}
/**
* <p>Returns a {@link java.util.Set} of names of <i>MAC</i> algorithms
* supported by this <i>Factory</i>.</p>
*
* @return a {@link java.util.Set} of MAC names (Strings).
*/
public static final Set getNames() {
synchronized (MacFactory.class) {
if (names == null) {
HashSet hs = new HashSet();
hs.addAll(HMacFactory.getNames());
hs.add(UHASH32);
hs.add(UMAC32);
hs.add(TMMH16);
// hs.add(TMMH32);
for (Iterator it = CipherFactory.getNames().iterator(); it.hasNext(); ) {
hs.add(OMAC_PREFIX + it.next());
}
names = Collections.unmodifiableSet(hs);
}
}
return names;
}
private static Set names;
// Instance methods
// -------------------------------------------------------------------------
}