| /* |
| * Copyright (c) 1997, 2011, 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; |
| |
| /** |
| * This class provides the functionality of a secret (symmetric) key generator. |
| * |
| * <p>Key generators are constructed using one of the <code>getInstance</code> |
| * class methods of this class. |
| * |
| * <p>KeyGenerator objects are reusable, i.e., after a key has been |
| * generated, the same KeyGenerator object can be re-used to generate further |
| * keys. |
| * |
| * <p>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: |
| * |
| * <ul> |
| * <li><b>Algorithm-Independent Initialization</b> |
| * <p>All key generators share the concepts of a <i>keysize</i> and a |
| * <i>source of randomness</i>. |
| * There is an |
| * {@link #init(int, java.security.SecureRandom) init} |
| * method in this KeyGenerator class that takes these two universally |
| * shared types of arguments. There is also one that takes just a |
| * <code>keysize</code> argument, and uses the SecureRandom implementation |
| * of the highest-priority installed provider as the source of randomness |
| * (or a system-provided source of randomness if none of the installed |
| * providers supply a SecureRandom implementation), and one that takes just a |
| * source of randomness. |
| * |
| * <p>Since no other parameters are specified when you call the above |
| * algorithm-independent <code>init</code> methods, it is up to the |
| * provider what to do about the algorithm-specific parameters (if any) to be |
| * associated with each of the keys. |
| * <p> |
| * |
| * <li><b>Algorithm-Specific Initialization</b> |
| * <p>For situations where a set of algorithm-specific parameters already |
| * exists, there are two |
| * {@link #init(java.security.spec.AlgorithmParameterSpec) init} |
| * methods that have an <code>AlgorithmParameterSpec</code> |
| * argument. One also has a <code>SecureRandom</code> argument, while the |
| * other uses the SecureRandom implementation |
| * of the highest-priority installed provider as the source of randomness |
| * (or a system-provided source of randomness if none of the installed |
| * providers supply a SecureRandom implementation). |
| * </ul> |
| * |
| * <p>In case the client does not explicitly initialize the KeyGenerator |
| * (via a call to an <code>init</code> method), each provider must |
| * supply (and document) a default initialization. |
| * |
| * <p> Every implementation of the Java platform is required to support the |
| * following standard <code>KeyGenerator</code> algorithms with the keysizes in |
| * parentheses: |
| * <ul> |
| * <li><tt>AES</tt> (128)</li> |
| * <li><tt>DES</tt> (56)</li> |
| * <li><tt>DESede</tt> (168)</li> |
| * <li><tt>HmacSHA1</tt></li> |
| * <li><tt>HmacSHA256</tt></li> |
| * </ul> |
| * These algorithms are described in the <a href= |
| * "{@docRoot}/../technotes/guides/security/StandardNames.html#KeyGenerator"> |
| * KeyGenerator section</a> of the |
| * Java Cryptography Architecture Standard Algorithm Name Documentation. |
| * Consult the release documentation for your implementation to see if any |
| * other algorithms are supported. |
| * |
| * @author Jan Luehe |
| * |
| * @see SecretKey |
| * @since 1.4 |
| */ |
| |
| public class 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; |
| } |
| |
| 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"); |
| } |
| } |
| |
| /** |
| * Returns the algorithm name of this <code>KeyGenerator</code> object. |
| * |
| * <p>This is the same name that was specified in one of the |
| * <code>getInstance</code> calls that created this |
| * <code>KeyGenerator</code> object. |
| * |
| * @return the algorithm name of this <code>KeyGenerator</code> object. |
| */ |
| public final String getAlgorithm() { |
| return this.algorithm; |
| } |
| |
| /** |
| * Returns a <code>KeyGenerator</code> object that generates secret keys |
| * for the specified algorithm. |
| * |
| * <p> 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. |
| * |
| * <p> 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 <a href= |
| * "{@docRoot}/../technotes/guides/security/StandardNames.html#KeyGenerator"> |
| * Java Cryptography Architecture Standard Algorithm Name Documentation</a> |
| * for information about standard algorithm names. |
| * |
| * @return the new <code>KeyGenerator</code> 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 <code>KeyGenerator</code> object that generates secret keys |
| * for the specified algorithm. |
| * |
| * <p> 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. |
| * |
| * <p> 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 <a href= |
| * "{@docRoot}/../technotes/guides/security/StandardNames.html#KeyGenerator"> |
| * Java Cryptography Architecture Standard Algorithm Name Documentation</a> |
| * for information about standard algorithm names. |
| * |
| * @param provider the name of the provider. |
| * |
| * @return the new <code>KeyGenerator</code> 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 <code>provider</code> |
| * 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 <code>KeyGenerator</code> object that generates secret keys |
| * for the specified algorithm. |
| * |
| * <p> 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 <a href= |
| * "{@docRoot}/../technotes/guides/security/StandardNames.html#KeyGenerator"> |
| * Java Cryptography Architecture Standard Algorithm Name Documentation</a> |
| * for information about standard algorithm names. |
| * |
| * @param provider the provider. |
| * |
| * @return the new <code>KeyGenerator</code> 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 <code>provider</code> |
| * 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 <code>KeyGenerator</code> object. |
| * |
| * @return the provider of this <code>KeyGenerator</code> 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 = (Service)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. |
| * |
| * <p> If this key generator requires any random bytes, it will get them |
| * using the |
| * {@link SecureRandom <code>SecureRandom</code>} |
| * 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 <code>params</code> 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. |
| * |
| * <p> If this key generator requires any random bytes, it will get them |
| * using the |
| * {@link SecureRandom <code>SecureRandom</code>} |
| * 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; |
| } |
| } |