| /* MacFactory.java -- |
| Copyright (C) 2001, 2002, 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. */ |
| |
| |
| package gnu.javax.crypto.mac; |
| |
| import gnu.java.security.Registry; |
| import gnu.javax.crypto.cipher.CipherFactory; |
| import gnu.javax.crypto.cipher.IBlockCipher; |
| |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.Set; |
| |
| /** |
| * A <i>Factory</i> that instantiates instances of every supported Message |
| * Authentication Code algorithms, including all <i>HMAC</i> algorithms. |
| */ |
| public class MacFactory |
| implements Registry |
| { |
| private static Set names; |
| |
| /** Trivial constructor to enforce <i>Singleton</i> pattern. */ |
| private MacFactory() |
| { |
| super(); |
| } |
| |
| /** |
| * Returns an instance of a <i>MAC</i> algorithm given its name. |
| * |
| * @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(); |
| |
| if (result != null && ! result.selfTest()) |
| throw new InternalError(result.name()); |
| |
| return result; |
| } |
| |
| /** |
| * Returns a {@link Set} of names of <i>MAC</i> algorithms supported by this |
| * <i>Factory</i>. |
| * |
| * @return a {@link 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); |
| for (Iterator it = CipherFactory.getNames().iterator(); it.hasNext();) |
| hs.add(OMAC_PREFIX + it.next()); |
| |
| names = Collections.unmodifiableSet(hs); |
| } |
| } |
| return names; |
| } |
| } |