java.security.KeyFactory Maven / Gradle / Ivy
/*
* 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 java.security;
import java.security.spec.InvalidKeySpecException;
import java.security.spec.KeySpec;
import org.apache.harmony.security.fortress.Engine;
/**
* {@code KeyFactory} is an engine class that can be used to translate between
* public and private key objects and convert keys between their external
* representation, that can be easily transported and their internal
* representation.
*/
public class KeyFactory {
// The service name.
private static final String SERVICE = "KeyFactory";
// Used to access common engine functionality
private static final Engine ENGINE = new Engine(SERVICE);
// The provider
private final Provider provider;
// The SPI implementation.
private final KeyFactorySpi spiImpl;
// The algorithm.
private final String algorithm;
/**
* Constructs a new instance of {@code KeyFactory} with the specified
* arguments.
*
* @param keyFacSpi
* the concrete key factory service.
* @param provider
* the provider.
* @param algorithm
* the algorithm to use.
*/
protected KeyFactory(KeyFactorySpi keyFacSpi,
Provider provider,
String algorithm) {
this.provider = provider;
this.algorithm = algorithm;
this.spiImpl = keyFacSpi;
}
/**
* Returns a new instance of {@code KeyFactory} that utilizes the specified
* algorithm.
*
* @param algorithm
* the name of the algorithm.
* @return a new instance of {@code KeyFactory} that utilizes the specified
* algorithm.
* @throws NoSuchAlgorithmException
* if no provider provides the requested algorithm.
*/
public static KeyFactory getInstance(String algorithm)
throws NoSuchAlgorithmException {
if (algorithm == null) {
throw new NullPointerException("algorithm == null");
}
Engine.SpiAndProvider sap = ENGINE.getInstance(algorithm, null);
return new KeyFactory((KeyFactorySpi) sap.spi, sap.provider, algorithm);
}
/**
* Returns a new instance of {@code KeyFactory} that utilizes the specified
* algorithm from the specified provider.
*
* @param algorithm
* the name of the algorithm.
* @param provider
* the name of the provider.
* @return a new instance of {@code KeyFactory} that utilizes the specified
* algorithm from the specified provider.
* @throws NoSuchAlgorithmException
* if the provider does not provide the requested algorithm.
* @throws NoSuchProviderException
* if the requested provider is not available.
* @throws IllegalArgumentException if {@code provider == null || provider.isEmpty()}
*/
public static KeyFactory getInstance(String algorithm, String provider)
throws NoSuchAlgorithmException, NoSuchProviderException {
if (provider == null || provider.isEmpty()) {
throw new IllegalArgumentException();
}
Provider p = Security.getProvider(provider);
if (p == null) {
throw new NoSuchProviderException(provider);
}
return getInstance(algorithm, p);
}
/**
* Returns a new instance of {@code KeyFactory} that utilizes the specified
* algorithm from the specified provider.
*
* @param algorithm
* the name of the algorithm.
* @param provider
* the security provider.
* @return a new instance of {@code KeyFactory} that utilizes the specified
* algorithm from the specified provider.
* @throws NoSuchAlgorithmException
* if the provider does not provide the requested algorithm.
* @throws IllegalArgumentException if {@code provider == null}
*/
public static KeyFactory getInstance(String algorithm, Provider provider)
throws NoSuchAlgorithmException {
if (provider == null) {
throw new IllegalArgumentException("provider == null");
}
if (algorithm == null) {
throw new NullPointerException("algorithm == null");
}
Object spi = ENGINE.getInstance(algorithm, provider, null);
return new KeyFactory((KeyFactorySpi) spi, provider, algorithm);
}
/**
* Returns the provider associated with this {@code KeyFactory}.
*
* @return the provider associated with this {@code KeyFactory}.
*/
public final Provider getProvider() {
return provider;
}
/**
* Returns the name of the algorithm associated with this {@code
* KeyFactory}.
*
* @return the name of the algorithm associated with this {@code
* KeyFactory}.
*/
public final String getAlgorithm() {
return algorithm;
}
/**
* Generates a instance of {@code PublicKey} from the given key
* specification.
*
* @param keySpec
* the specification of the public key
* @return the public key
* @throws InvalidKeySpecException
* if the specified {@code keySpec} is invalid
*/
public final PublicKey generatePublic(KeySpec keySpec)
throws InvalidKeySpecException {
return spiImpl.engineGeneratePublic(keySpec);
}
/**
* Generates a instance of {@code PrivateKey} from the given key
* specification.
*
* @param keySpec
* the specification of the private key.
* @return the private key.
* @throws InvalidKeySpecException
* if the specified {@code keySpec} is invalid.
*/
public final PrivateKey generatePrivate(KeySpec keySpec)
throws InvalidKeySpecException {
return spiImpl.engineGeneratePrivate(keySpec);
}
/**
* Returns the key specification for the specified key.
*
* @param key
* the key from which the specification is requested.
* @param keySpec
* the type of the requested {@code KeySpec}.
* @return the key specification for the specified key.
* @throws InvalidKeySpecException
* if the key can not be processed, or the requested requested
* {@code KeySpec} is inappropriate for the given key.
*/
public final T getKeySpec(Key key,
Class keySpec)
throws InvalidKeySpecException {
return spiImpl.engineGetKeySpec(key, keySpec);
}
/**
* Translates the given key into a key from this key factory.
*
* @param key
* the key to translate.
* @return the translated key.
* @throws InvalidKeyException
* if the specified key can not be translated by this key
* factory.
*/
public final Key translateKey(Key key)
throws InvalidKeyException {
return spiImpl.engineTranslateKey(key);
}
}