| /* KeyGenerator.java -- Interface to a symmetric key generator. |
| Copyright (C) 2004 Free Software Foundation, Inc. |
| |
| This file is 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, 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; 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. */ |
| |
| |
| package javax.crypto; |
| |
| import gnu.java.security.Engine; |
| |
| import java.lang.reflect.InvocationTargetException; |
| import java.security.InvalidAlgorithmParameterException; |
| import java.security.NoSuchAlgorithmException; |
| import java.security.NoSuchProviderException; |
| import java.security.Provider; |
| import java.security.SecureRandom; |
| import java.security.Security; |
| import java.security.spec.AlgorithmParameterSpec; |
| |
| /** |
| * A generic producer of keys for symmetric cryptography. The keys |
| * returned may be simple wrappers around byte arrays, or, if the |
| * target cipher requires them, more complex objects. |
| * |
| * @author Casey Marshall (csm@gnu.org) |
| * @since 1.4 |
| * @see Cipher |
| * @see Mac |
| */ |
| public class KeyGenerator |
| { |
| |
| // Constants and fields. |
| // ------------------------------------------------------------------------ |
| |
| private static final String SERVICE = "KeyGenerator"; |
| |
| /** The underlying generator implementation. */ |
| private KeyGeneratorSpi kgSpi; |
| |
| /** The provider of the implementation. */ |
| private Provider provider; |
| |
| /** The name of the algorithm. */ |
| private String algorithm; |
| |
| // Constructor. |
| // ------------------------------------------------------------------------ |
| |
| /** |
| * Create a new key generator. |
| * |
| * @param kgSpi The underlying generator. |
| * @param provider The provider of this implementation. |
| * @param algorithm The algorithm's name. |
| */ |
| protected KeyGenerator(KeyGeneratorSpi kgSpi, Provider provider, |
| String algorithm) |
| { |
| this.kgSpi = kgSpi; |
| this.provider = provider; |
| this.algorithm = algorithm; |
| } |
| |
| // Class methods. |
| // ------------------------------------------------------------------------ |
| |
| /** |
| * Create a new key generator, returning the first available |
| * implementation. |
| * |
| * @param algorithm The generator algorithm name. |
| * @throws java.security.NoSuchAlgorithmException If the specified |
| * algorithm does not exist. |
| */ |
| public static final KeyGenerator getInstance(String algorithm) |
| throws NoSuchAlgorithmException |
| { |
| Provider[] provs = Security.getProviders(); |
| String msg = algorithm; |
| for (int i = 0; i < provs.length; i++) |
| { |
| try |
| { |
| return getInstance(algorithm, provs[i]); |
| } |
| catch (NoSuchAlgorithmException nsae) |
| { |
| msg = nsae.getMessage(); |
| } |
| } |
| throw new NoSuchAlgorithmException(msg); |
| } |
| |
| /** |
| * Create a new key generator from the named provider. |
| * |
| * @param algorithm The generator algorithm name. |
| * @param provider The name of the provider to use. |
| * @return An appropriate key generator, if found. |
| * @throws java.security.NoSuchAlgorithmException If the specified |
| * algorithm is not implemented by the named provider. |
| * @throws java.security.NoSuchProviderException If the named provider |
| * does not exist. |
| */ |
| public static final KeyGenerator getInstance(String algorithm, String provider) |
| throws NoSuchAlgorithmException, NoSuchProviderException |
| { |
| Provider p = Security.getProvider(provider); |
| if (p == null) |
| { |
| throw new NoSuchProviderException(provider); |
| } |
| return getInstance(algorithm, p); |
| } |
| |
| /** |
| * Create a new key generator from the supplied provider. |
| * |
| * @param algorithm The generator algorithm name. |
| * @param provider The provider to use. |
| * @return An appropriate key generator, if found. |
| * @throws java.security.NoSuchAlgorithmException If the specified |
| * algorithm is not implemented by the provider. |
| */ |
| public static final KeyGenerator getInstance(String algorithm, Provider provider) |
| throws NoSuchAlgorithmException |
| { |
| try |
| { |
| KeyGenerator instance = new KeyGenerator((KeyGeneratorSpi) |
| Engine.getInstance(SERVICE, algorithm, provider), |
| provider, algorithm); |
| instance.init(new SecureRandom()); |
| return instance; |
| } |
| catch (InvocationTargetException ite) |
| { |
| if (ite.getCause() == null) |
| throw new NoSuchAlgorithmException(algorithm); |
| if (ite.getCause() instanceof NoSuchAlgorithmException) |
| throw (NoSuchAlgorithmException) ite.getCause(); |
| throw new NoSuchAlgorithmException(algorithm); |
| } |
| catch (ClassCastException cce) |
| { |
| throw new NoSuchAlgorithmException(algorithm); |
| } |
| } |
| |
| // Instance methods. |
| // ------------------------------------------------------------------------ |
| |
| /** |
| * Generate a key. |
| * |
| * @return The new key. |
| */ |
| public final SecretKey generateKey() |
| { |
| return kgSpi.engineGenerateKey(); |
| } |
| |
| /** |
| * Return the name of this key generator. |
| * |
| * @return The algorithm name. |
| */ |
| public final String getAlgorithm() |
| { |
| return algorithm; |
| } |
| |
| /** |
| * Return the provider of the underlying implementation. |
| * |
| * @return The provider. |
| */ |
| public final Provider getProvider() |
| { |
| return provider; |
| } |
| |
| /** |
| * Initialize this key generator with a set of parameters; the |
| * highest-priority {@link java.security.SecureRandom} implementation |
| * will be used. |
| * |
| * @param params The algorithm parameters. |
| * @throws java.security.InvalidAlgorithmParameterException If the |
| * supplied parameters are inapproprate. |
| */ |
| public final void init(AlgorithmParameterSpec params) |
| throws InvalidAlgorithmParameterException |
| { |
| init(params, new SecureRandom()); |
| } |
| |
| /** |
| * Initialize this key generator with a set of parameters and a source |
| * of randomness. |
| * |
| * @param params The algorithm parameters. |
| * @param random The source of randomness. |
| * @throws java.security.InvalidAlgorithmParameterException If the |
| * supplied parameters are inapproprate. |
| */ |
| public final void init(AlgorithmParameterSpec params, SecureRandom random) |
| throws InvalidAlgorithmParameterException |
| { |
| kgSpi.engineInit(params, random); |
| } |
| |
| /** |
| * Initialize this key generator with a key size (in bits); the |
| * highest-priority {@link java.security.SecureRandom} implementation |
| * will be used. |
| * |
| * @param keySize The target key size, in bits. |
| * @throws java.security.InvalidParameterException If the |
| * key size is unsupported. |
| */ |
| public final void init(int keySize) |
| { |
| init(keySize, new SecureRandom()); |
| } |
| |
| /** |
| * Initialize this key generator with a key size (in bits) and a |
| * source of randomness. |
| * |
| * @param keySize The target key size, in bits. |
| * @param random The source of randomness. |
| * @throws java.security.InvalidAlgorithmParameterException If the |
| * key size is unsupported. |
| */ |
| public final void init(int keySize, SecureRandom random) |
| { |
| kgSpi.engineInit(keySize, random); |
| } |
| |
| /** |
| * Initialize this key generator with a source of randomness. The |
| * implementation-specific default parameters (such as key size) will |
| * be used. |
| * |
| * @param random The source of randomness. |
| */ |
| public final void init(SecureRandom random) |
| { |
| kgSpi.engineInit(random); |
| } |
| } |