/* * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved. * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. * * This code is free software; you can redistribute it and/or modify it * under the terms of the GNU General Public License version 2 only, as * published by the Free Software Foundation. Oracle designates this * particular file as subject to the "Classpath" exception as provided * by Oracle in the LICENSE file that accompanied this code. * * This code 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 * version 2 for more details (a copy is included in the LICENSE file that * accompanied this code). * * You should have received a copy of the GNU General Public License version * 2 along with this work; if not, write to the Free Software Foundation, * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. * * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA * or visit www.oracle.com if you need additional information or have any * questions. */ package javax.crypto; import java.util.*; import java.security.*; import java.security.Provider.Service; import java.security.spec.*; import sun.security.jca.*; import sun.security.jca.GetInstance.Instance; /* Android-removed: this debugging mechanism is not used in Android. import sun.security.util.Debug; */ /** * This class provides the functionality of a secret (symmetric) key generator. * *

Key generators are constructed using one of the getInstance * class methods of this class. * *

KeyGenerator objects are reusable, i.e., after a key has been * generated, the same KeyGenerator object can be re-used to generate further * keys. * *

There are two ways to generate a key: in an algorithm-independent * manner, and in an algorithm-specific manner. * The only difference between the two is the initialization of the object: * *

* *

In case the client does not explicitly initialize the KeyGenerator * (via a call to an init method), each provider must * supply (and document) a default initialization. * *

Android provides the following KeyGenerator algorithms: * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
AlgorithmSupported API Levels
AES1+
AESWRAP1-8
ARC414+
BLOWFISH10+
DES1+
DESede1+
DESedeWRAP1-8
HmacMD51+
HmacSHA111+
HmacSHA2241-8,22+
HmacSHA2561+
HmacSHA3841+
HmacSHA5121+
RC410-13
* * These algorithms are described in the * KeyGenerator section of the * Java Cryptography Architecture Standard Algorithm Name Documentation. * * @author Jan Luehe * * @see SecretKey * @since 1.4 */ public class KeyGenerator { /* Android-removed: this debugging mechanism is not used in Android. private static final Debug pdebug = Debug.getInstance("provider", "Provider"); private static final boolean skipDebug = Debug.isOn("engine=") && !Debug.isOn("keygenerator"); */ // see java.security.KeyPairGenerator for failover notes private final static int I_NONE = 1; private final static int I_RANDOM = 2; private final static int I_PARAMS = 3; private final static int I_SIZE = 4; // The provider private Provider provider; // The provider implementation (delegate) private volatile KeyGeneratorSpi spi; // The algorithm private final String algorithm; private final Object lock = new Object(); private Iterator serviceIterator; private int initType; private int initKeySize; private AlgorithmParameterSpec initParams; private SecureRandom initRandom; /** * Creates a KeyGenerator object. * * @param keyGenSpi the delegate * @param provider the provider * @param algorithm the algorithm */ protected KeyGenerator(KeyGeneratorSpi keyGenSpi, Provider provider, String algorithm) { this.spi = keyGenSpi; this.provider = provider; this.algorithm = algorithm; /* Android-removed: this debugging mechanism is not used in Android. if (!skipDebug && pdebug != null) { pdebug.println("KeyGenerator." + algorithm + " algorithm from: " + this.provider.getName()); } */ } private KeyGenerator(String algorithm) throws NoSuchAlgorithmException { this.algorithm = algorithm; List list = GetInstance.getServices("KeyGenerator", algorithm); serviceIterator = list.iterator(); initType = I_NONE; // fetch and instantiate initial spi if (nextSpi(null, false) == null) { throw new NoSuchAlgorithmException (algorithm + " KeyGenerator not available"); } /* Android-removed: this debugging mechanism is not used in Android. if (!skipDebug && pdebug != null) { pdebug.println("KeyGenerator." + algorithm + " algorithm from: " + this.provider.getName()); } */ } /** * Returns the algorithm name of this KeyGenerator object. * *

This is the same name that was specified in one of the * getInstance calls that created this * KeyGenerator object. * * @return the algorithm name of this KeyGenerator object. */ public final String getAlgorithm() { return this.algorithm; } /** * Returns a KeyGenerator object that generates secret keys * for the specified algorithm. * *

This method traverses the list of registered security Providers, * starting with the most preferred Provider. * A new KeyGenerator object encapsulating the * KeyGeneratorSpi implementation from the first * Provider that supports the specified algorithm is returned. * *

Note that the list of registered providers may be retrieved via * the {@link Security#getProviders() Security.getProviders()} method. * * @param algorithm the standard name of the requested key algorithm. * See the KeyGenerator section in the * Java Cryptography Architecture Standard Algorithm Name Documentation * for information about standard algorithm names. * * @return the new KeyGenerator object. * * @exception NullPointerException if the specified algorithm is null. * * @exception NoSuchAlgorithmException if no Provider supports a * KeyGeneratorSpi implementation for the * specified algorithm. * * @see java.security.Provider */ public static final KeyGenerator getInstance(String algorithm) throws NoSuchAlgorithmException { return new KeyGenerator(algorithm); } /** * Returns a KeyGenerator object that generates secret keys * for the specified algorithm. * *

A new KeyGenerator object encapsulating the * KeyGeneratorSpi implementation from the specified provider * is returned. The specified provider must be registered * in the security provider list. * *

Note that the list of registered providers may be retrieved via * the {@link Security#getProviders() Security.getProviders()} method. * * @param algorithm the standard name of the requested key algorithm. * See the KeyGenerator section in the * Java Cryptography Architecture Standard Algorithm Name Documentation * for information about standard algorithm names. * * @param provider the name of the provider. * * @return the new KeyGenerator object. * * @exception NullPointerException if the specified algorithm is null. * * @exception NoSuchAlgorithmException if a KeyGeneratorSpi * implementation for the specified algorithm is not * available from the specified provider. * * @exception NoSuchProviderException if the specified provider is not * registered in the security provider list. * * @exception IllegalArgumentException if the provider * is null or empty. * * @see java.security.Provider */ public static final KeyGenerator getInstance(String algorithm, String provider) throws NoSuchAlgorithmException, NoSuchProviderException { Instance instance = JceSecurity.getInstance("KeyGenerator", KeyGeneratorSpi.class, algorithm, provider); return new KeyGenerator((KeyGeneratorSpi)instance.impl, instance.provider, algorithm); } /** * Returns a KeyGenerator object that generates secret keys * for the specified algorithm. * *

A new KeyGenerator object encapsulating the * KeyGeneratorSpi implementation from the specified Provider * object is returned. Note that the specified Provider object * does not have to be registered in the provider list. * * @param algorithm the standard name of the requested key algorithm. * See the KeyGenerator section in the * Java Cryptography Architecture Standard Algorithm Name Documentation * for information about standard algorithm names. * * @param provider the provider. * * @return the new KeyGenerator object. * * @exception NullPointerException if the specified algorithm is null. * * @exception NoSuchAlgorithmException if a KeyGeneratorSpi * implementation for the specified algorithm is not available * from the specified Provider object. * * @exception IllegalArgumentException if the provider * is null. * * @see java.security.Provider */ public static final KeyGenerator getInstance(String algorithm, Provider provider) throws NoSuchAlgorithmException { Instance instance = JceSecurity.getInstance("KeyGenerator", KeyGeneratorSpi.class, algorithm, provider); return new KeyGenerator((KeyGeneratorSpi)instance.impl, instance.provider, algorithm); } /** * Returns the provider of this KeyGenerator object. * * @return the provider of this KeyGenerator object */ public final Provider getProvider() { synchronized (lock) { disableFailover(); return provider; } } /** * Update the active spi of this class and return the next * implementation for failover. If no more implemenations are * available, this method returns null. However, the active spi of * this class is never set to null. */ private KeyGeneratorSpi nextSpi(KeyGeneratorSpi oldSpi, boolean reinit) { synchronized (lock) { // somebody else did a failover concurrently // try that spi now if ((oldSpi != null) && (oldSpi != spi)) { return spi; } if (serviceIterator == null) { return null; } while (serviceIterator.hasNext()) { Service s = serviceIterator.next(); if (JceSecurity.canUseProvider(s.getProvider()) == false) { continue; } try { Object inst = s.newInstance(null); // ignore non-spis if (inst instanceof KeyGeneratorSpi == false) { continue; } KeyGeneratorSpi spi = (KeyGeneratorSpi)inst; if (reinit) { if (initType == I_SIZE) { spi.engineInit(initKeySize, initRandom); } else if (initType == I_PARAMS) { spi.engineInit(initParams, initRandom); } else if (initType == I_RANDOM) { spi.engineInit(initRandom); } else if (initType != I_NONE) { throw new AssertionError ("KeyGenerator initType: " + initType); } } provider = s.getProvider(); this.spi = spi; return spi; } catch (Exception e) { // ignore } } disableFailover(); return null; } } void disableFailover() { serviceIterator = null; initType = 0; initParams = null; initRandom = null; } /** * Initializes this key generator. * * @param random the source of randomness for this generator */ public final void init(SecureRandom random) { if (serviceIterator == null) { spi.engineInit(random); return; } RuntimeException failure = null; KeyGeneratorSpi mySpi = spi; do { try { mySpi.engineInit(random); initType = I_RANDOM; initKeySize = 0; initParams = null; initRandom = random; return; } catch (RuntimeException e) { if (failure == null) { failure = e; } mySpi = nextSpi(mySpi, false); } } while (mySpi != null); throw failure; } /** * Initializes this key generator with the specified parameter set. * *

If this key generator requires any random bytes, it will get them * using the * {@link java.security.SecureRandom} * implementation of the highest-priority installed * provider as the source of randomness. * (If none of the installed providers supply an implementation of * SecureRandom, a system-provided source of randomness will be used.) * * @param params the key generation parameters * * @exception InvalidAlgorithmParameterException if the given parameters * are inappropriate for this key generator */ public final void init(AlgorithmParameterSpec params) throws InvalidAlgorithmParameterException { init(params, JceSecurity.RANDOM); } /** * Initializes this key generator with the specified parameter * set and a user-provided source of randomness. * * @param params the key generation parameters * @param random the source of randomness for this key generator * * @exception InvalidAlgorithmParameterException if params is * inappropriate for this key generator */ public final void init(AlgorithmParameterSpec params, SecureRandom random) throws InvalidAlgorithmParameterException { if (serviceIterator == null) { spi.engineInit(params, random); return; } Exception failure = null; KeyGeneratorSpi mySpi = spi; do { try { mySpi.engineInit(params, random); initType = I_PARAMS; initKeySize = 0; initParams = params; initRandom = random; return; } catch (Exception e) { if (failure == null) { failure = e; } mySpi = nextSpi(mySpi, false); } } while (mySpi != null); if (failure instanceof InvalidAlgorithmParameterException) { throw (InvalidAlgorithmParameterException)failure; } if (failure instanceof RuntimeException) { throw (RuntimeException)failure; } throw new InvalidAlgorithmParameterException("init() failed", failure); } /** * Initializes this key generator for a certain keysize. * *

If this key generator requires any random bytes, it will get them * using the * {@link java.security.SecureRandom} * implementation of the highest-priority installed * provider as the source of randomness. * (If none of the installed providers supply an implementation of * SecureRandom, a system-provided source of randomness will be used.) * * @param keysize the keysize. This is an algorithm-specific metric, * specified in number of bits. * * @exception InvalidParameterException if the keysize is wrong or not * supported. */ public final void init(int keysize) { init(keysize, JceSecurity.RANDOM); } /** * Initializes this key generator for a certain keysize, using a * user-provided source of randomness. * * @param keysize the keysize. This is an algorithm-specific metric, * specified in number of bits. * @param random the source of randomness for this key generator * * @exception InvalidParameterException if the keysize is wrong or not * supported. */ public final void init(int keysize, SecureRandom random) { if (serviceIterator == null) { spi.engineInit(keysize, random); return; } RuntimeException failure = null; KeyGeneratorSpi mySpi = spi; do { try { mySpi.engineInit(keysize, random); initType = I_SIZE; initKeySize = keysize; initParams = null; initRandom = random; return; } catch (RuntimeException e) { if (failure == null) { failure = e; } mySpi = nextSpi(mySpi, false); } } while (mySpi != null); throw failure; } /** * Generates a secret key. * * @return the new key */ public final SecretKey generateKey() { if (serviceIterator == null) { return spi.engineGenerateKey(); } RuntimeException failure = null; KeyGeneratorSpi mySpi = spi; do { try { return mySpi.engineGenerateKey(); } catch (RuntimeException e) { if (failure == null) { failure = e; } mySpi = nextSpi(mySpi, true); } } while (mySpi != null); throw failure; } }