/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package javax.crypto;
import java.security.InvalidKeyException;
import java.security.NoSuchAlgorithmException;
import java.security.NoSuchProviderException;
import java.security.Provider;
import java.security.Security;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;
import org.apache.harmony.crypto.internal.nls.Messages;
import org.apache.harmony.security.fortress.Engine;
/**
* The public API for {@code SecretKeyFactory} implementations.
* <p>
* Secret key factories provide the following functionality:
* <ul>
* <li>convert {@link SecretKey} objects to and from {@link KeySpec} objects</li>
* <li>translate {@link SecretKey} objects from one provider implementation to
* another</li>
* </ul>
* Which key specifications are supported by the {@link #generateSecret} and
* {@link #getKeySpec} is provider dependent.
* </p>
*
* @since Android 1.0
*/
public class SecretKeyFactory {
// Used to access common engine functionality
private static final Engine engine = new Engine("SecretKeyFactory"); //$NON-NLS-1$
// Store used provider
private final Provider provider;
// Store used spi implementation
private final SecretKeyFactorySpi spiImpl;
// Store used algorithm name
private final String algorithm;
/**
* Creates a new {@code SecretKeyFactory}
*
* @param keyFacSpi
* the SPI delegate.
* @param provider
* the provider providing this key factory.
* @param algorithm
* the algorithm name for the secret key.
* @since Android 1.0
*/
protected SecretKeyFactory(SecretKeyFactorySpi keyFacSpi,
Provider provider, String algorithm) {
this.provider = provider;
this.algorithm = algorithm;
this.spiImpl = keyFacSpi;
}
/**
* Returns the name of the secret key algorithm.
*
* @return the name of the secret key algorithm.
* @since Android 1.0
*/
public final String getAlgorithm() {
return algorithm;
}
/**
* Returns the provider for this {@code SecretKeyFactory} instance.
*
* @return the provider for this {@code SecretKeyFactory} instance.
* @since Android 1.0
*/
public final Provider getProvider() {
return provider;
}
/**
* Creates a new {@code SecretKeyFactory} instance for the specified key
* algorithm.
*
* @param algorithm
* the name of the key algorithm.
* @return a secret key factory for the specified key algorithm.
* @throws NoSuchAlgorithmException
* if no installed provider can provide the requested algorithm.
* @throws NullPointerException
* if the specified algorithm is {@code null}.
* @since Android 1.0
*/
public static final SecretKeyFactory getInstance(String algorithm)
throws NoSuchAlgorithmException {
if (algorithm == null) {
throw new NullPointerException(Messages.getString("crypto.02")); //$NON-NLS-1$
}
synchronized (engine) {
engine.getInstance(algorithm, null);
return new SecretKeyFactory((SecretKeyFactorySpi) engine.spi,
engine.provider, algorithm);
}
}
/**
* Creates a new {@code SecretKeyFactory} instance for the specified key
* algorithm from the specified {@code provider}.
*
* @param algorithm
* the name of the key algorithm.
* @param provider
* the name of the provider that provides the requested
* algorithm.
* @return a secret key factory for the specified key algorithm from the
* specified provider.
* @throws NoSuchAlgorithmException
* if the specified provider cannot provide the requested
* algorithm.
* @throws NoSuchProviderException
* if the specified provider does not exist.
* @throws IllegalArgumentException
* if the specified provider name is {@code null} or empty.
* @since Android 1.0
*/
public static final SecretKeyFactory getInstance(String algorithm,
String provider) throws NoSuchAlgorithmException,
NoSuchProviderException {
if ((provider == null) || (provider.length() == 0)) {
throw new IllegalArgumentException(Messages.getString("crypto.03")); //$NON-NLS-1$
}
Provider impProvider = Security.getProvider(provider);
if (impProvider == null) {
throw new NoSuchProviderException(provider);
}
return getInstance(algorithm, impProvider);
}
/**
* Creates a new {@code SecretKeyFactory} instance for the specified key
* algorithm from the specified provider.
*
* @param algorithm
* the name of the key algorithm.
* @param provider
* the provider that provides the requested algorithm.
* @return a secret key factory for the specified key algorithm from the
* specified provider.
* @throws NoSuchAlgorithmException
* if the specified provider cannot provider the requested
* algorithm.
* @throws IllegalArgumentException
* if the specified provider is {@code null}.
* @throws NullPointerException
* is the specified algorithm name is {@code null}.
* @since Android 1.0
*/
public static final SecretKeyFactory getInstance(String algorithm,
Provider provider) throws NoSuchAlgorithmException {
if (provider == null) {
throw new IllegalArgumentException(Messages.getString("crypto.04")); //$NON-NLS-1$
}
if (algorithm == null) {
throw new NullPointerException(Messages.getString("crypto.02")); //$NON-NLS-1$
}
synchronized (engine) {
engine.getInstance(algorithm, provider, null);
return new SecretKeyFactory((SecretKeyFactorySpi) engine.spi, provider,
algorithm);
}
}
/**
* Generate a secret key from the specified key specification.
*
* @param keySpec
* the key specification.
* @return a secret key.
* @throws InvalidKeySpecException
* if the specified key specification cannot be used to generate
* a secret key.
* @since Android 1.0
*/
public final SecretKey generateSecret(KeySpec keySpec)
throws InvalidKeySpecException {
return spiImpl.engineGenerateSecret(keySpec);
}
/**
* Returns the key specification of the specified secret key.
*
* @param key
* the secret key to get the specification from.
* @param keySpec
* the target key specification class.
* @return an instance of the specified key specification class.
* @throws InvalidKeySpecException
* if the specified secret key cannot be transformed into the
* requested key specification.
* @since Android 1.0
*/
@SuppressWarnings("unchecked")
public final KeySpec getKeySpec(SecretKey key, Class keySpec)
throws InvalidKeySpecException {
return spiImpl.engineGetKeySpec(key, keySpec);
}
/**
* Translates the specified secret key into an instance of the corresponding
* key from the provider of this key factory.
*
* @param key
* the secret key to translate.
* @return the corresponding translated key.
* @throws InvalidKeyException
* if the specified key cannot be translated using this key
* factory.
* @since Android 1.0
*/
public final SecretKey translateKey(SecretKey key)
throws InvalidKeyException {
return spiImpl.engineTranslateKey(key);
}
} |
