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Diffstat (limited to 'libjava/classpath/javax/crypto/KeyGenerator.java')
-rw-r--r-- | libjava/classpath/javax/crypto/KeyGenerator.java | 283 |
1 files changed, 283 insertions, 0 deletions
diff --git a/libjava/classpath/javax/crypto/KeyGenerator.java b/libjava/classpath/javax/crypto/KeyGenerator.java new file mode 100644 index 0000000..c3f4cee --- /dev/null +++ b/libjava/classpath/javax/crypto/KeyGenerator.java @@ -0,0 +1,283 @@ +/* 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 + { + return new KeyGenerator((KeyGeneratorSpi) + Engine.getInstance(SERVICE, algorithm, provider), + provider, algorithm); + } + 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); + } +} |