| /* PRNGFactory.java -- |
| Copyright (C) 2001, 2002, 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. */ |
| |
| |
| package gnu.javax.crypto.prng; |
| |
| import gnu.java.security.Registry; |
| import gnu.java.security.prng.IRandom; |
| import gnu.javax.crypto.mac.HMacFactory; |
| import gnu.javax.crypto.mac.IMac; |
| import gnu.javax.crypto.mac.MacFactory; |
| |
| import java.util.Collections; |
| import java.util.HashSet; |
| import java.util.Iterator; |
| import java.util.Set; |
| |
| /** |
| * A Factory to instantiate pseudo random number generators. |
| */ |
| public class PRNGFactory |
| implements Registry |
| { |
| /** Trivial constructor to enforce <i>Singleton</i> pattern. */ |
| private PRNGFactory() |
| { |
| } |
| |
| /** |
| * Returns an instance of a padding algorithm given its name. |
| * |
| * @param prng the case-insensitive name of the PRNG. |
| * @return an instance of the pseudo-random number generator. |
| * @exception InternalError if the implementation does not pass its self- |
| * test. |
| */ |
| public static IRandom getInstance(String prng) |
| { |
| if (prng == null) |
| return null; |
| prng = prng.trim(); |
| IRandom result = null; |
| if (prng.equalsIgnoreCase(ARCFOUR_PRNG) || prng.equalsIgnoreCase(RC4_PRNG)) |
| result = new ARCFour(); |
| else if (prng.equalsIgnoreCase(ICM_PRNG)) |
| result = new ICMGenerator(); |
| else if (prng.equalsIgnoreCase(UMAC_PRNG)) |
| result = new UMacGenerator(); |
| else if (prng.toLowerCase().startsWith(PBKDF2_PRNG_PREFIX)) |
| { |
| String macName = prng.substring(PBKDF2_PRNG_PREFIX.length()); |
| IMac mac = MacFactory.getInstance(macName); |
| if (mac == null) |
| return null; |
| result = new PBKDF2(mac); |
| } |
| |
| if (result != null) |
| return result; |
| |
| return gnu.java.security.prng.PRNGFactory.getInstance(prng); |
| } |
| |
| /** |
| * Returns a {@link Set} of names of padding algorithms supported by this |
| * <i>Factory</i>. |
| * |
| * @return a {@link Set} of pseudo-random number generator algorithm names |
| * (Strings). |
| */ |
| public static Set getNames() |
| { |
| HashSet hs = new HashSet(gnu.java.security.prng.PRNGFactory.getNames()); |
| hs.add(ICM_PRNG); |
| hs.add(UMAC_PRNG); |
| // add all hmac implementations as candidate PBKDF2 ones too |
| for (Iterator it = HMacFactory.getNames().iterator(); it.hasNext();) |
| hs.add(PBKDF2_PRNG_PREFIX + ((String) it.next())); |
| return Collections.unmodifiableSet(hs); |
| } |
| } |