| /* |
| * Copyright (c) 1997, 2017, 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 java.security; |
| |
| import dalvik.annotation.compat.VersionCodes; |
| import dalvik.system.VMRuntime; |
| |
| import java.security.spec.AlgorithmParameterSpec; |
| import java.util.Objects; |
| |
| /** |
| * The {@code AlgorithmParameterGenerator} class is used to generate a |
| * set of |
| * parameters to be used with a certain algorithm. Parameter generators |
| * are constructed using the {@code getInstance} factory methods |
| * (static methods that return instances of a given class). |
| * |
| * <P>The object that will generate the parameters can be initialized |
| * in two different ways: in an algorithm-independent manner, or in an |
| * algorithm-specific manner: |
| * |
| * <ul> |
| * <li>The algorithm-independent approach uses the fact that all parameter |
| * generators share the concept of a "size" and a |
| * source of randomness. The measure of size is universally shared |
| * by all algorithm parameters, though it is interpreted differently |
| * for different algorithms. For example, in the case of parameters for |
| * the <i>DSA</i> algorithm, "size" corresponds to the size |
| * of the prime modulus (in bits). |
| * When using this approach, algorithm-specific parameter generation |
| * values - if any - default to some standard values, unless they can be |
| * derived from the specified size. |
| * |
| * <li>The other approach initializes a parameter generator object |
| * using algorithm-specific semantics, which are represented by a set of |
| * algorithm-specific parameter generation values. To generate |
| * Diffie-Hellman system parameters, for example, the parameter generation |
| * values usually |
| * consist of the size of the prime modulus and the size of the |
| * random exponent, both specified in number of bits. |
| * </ul> |
| * |
| * <P>In case the client does not explicitly initialize the |
| * AlgorithmParameterGenerator (via a call to an {@code init} method), |
| * each provider must supply (and document) a default initialization. |
| * However, note that defaults may vary across different providers. |
| * Additionally, the default value for a provider may change in a future |
| * version. Therefore, it is recommended to explicitly initialize the |
| * AlgorithmParameterGenerator instead of relying on provider-specific defaults. |
| * |
| * <p> Android provides the following <code>AlgorithmParameterGenerator</code> algorithms: |
| * <table> |
| * <thead> |
| * <tr> |
| * <th>Algorithm</th> |
| * <th>Supported API Levels</th> |
| * </tr> |
| * </thead> |
| * <tbody> |
| * <tr class="deprecated"> |
| * <td>AES</td> |
| * <td>1-8</td> |
| * </tr> |
| * <tr class="deprecated"> |
| * <td>DES</td> |
| * <td>1-8</td> |
| * </tr> |
| * <tr class="deprecated"> |
| * <td>DESede</td> |
| * <td>1-8</td> |
| * </tr> |
| * <tr> |
| * <td>DH</td> |
| * <td>1+</td> |
| * </tr> |
| * <tr> |
| * <td>DSA</td> |
| * <td>1+</td> |
| * </tr> |
| * </tbody> |
| * </table> |
| * |
| * @author Jan Luehe |
| * |
| * |
| * @see AlgorithmParameters |
| * @see java.security.spec.AlgorithmParameterSpec |
| * |
| * @since 1.2 |
| */ |
| |
| public class AlgorithmParameterGenerator { |
| |
| // The provider |
| private Provider provider; |
| |
| // The provider implementation (delegate) |
| private AlgorithmParameterGeneratorSpi paramGenSpi; |
| |
| // The algorithm |
| private String algorithm; |
| |
| /** |
| * Creates an AlgorithmParameterGenerator object. |
| * |
| * @param paramGenSpi the delegate |
| * @param provider the provider |
| * @param algorithm the algorithm |
| */ |
| protected AlgorithmParameterGenerator |
| (AlgorithmParameterGeneratorSpi paramGenSpi, Provider provider, |
| String algorithm) { |
| this.paramGenSpi = paramGenSpi; |
| this.provider = provider; |
| this.algorithm = algorithm; |
| } |
| |
| /** |
| * Returns the standard name of the algorithm this parameter |
| * generator is associated with. |
| * |
| * @return the string name of the algorithm. |
| */ |
| public final String getAlgorithm() { |
| return this.algorithm; |
| } |
| |
| // Android-changed: javadoc to throw on Android 14 or above. |
| /** |
| * Returns an AlgorithmParameterGenerator object for generating |
| * a set of parameters to be used with the specified algorithm. |
| * |
| * <p> This method traverses the list of registered security Providers, |
| * starting with the most preferred Provider. |
| * A new AlgorithmParameterGenerator object encapsulating the |
| * AlgorithmParameterGeneratorSpi 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 name of the algorithm this |
| * parameter generator is associated with.cc |
| * |
| * @return the new {@code AlgorithmParameterGenerator} object |
| * |
| * @throws NoSuchAlgorithmException if no {@code Provider} supports an |
| * {@code AlgorithmParameterGeneratorSpi} implementation for the |
| * specified algorithm |
| * |
| * @throws NullPointerException if {@code algorithm} is {@code null} on Android 14 or above |
| * |
| * @see Provider |
| */ |
| public static AlgorithmParameterGenerator getInstance(String algorithm) |
| throws NoSuchAlgorithmException { |
| // Android-changed: To be compat with the older Android, don't throw NPE on Android 13-. |
| // Objects.requireNonNull(algorithm, "null algorithm name"); |
| if (VMRuntime.getSdkVersion() >= VersionCodes.UPSIDE_DOWN_CAKE) { |
| Objects.requireNonNull(algorithm, "null algorithm name"); |
| } |
| try { |
| Object[] objs = Security.getImpl(algorithm, |
| "AlgorithmParameterGenerator", |
| (String)null); |
| return new AlgorithmParameterGenerator |
| ((AlgorithmParameterGeneratorSpi)objs[0], |
| (Provider)objs[1], |
| algorithm); |
| } catch(NoSuchProviderException e) { |
| throw new NoSuchAlgorithmException(algorithm + " not found"); |
| } |
| } |
| |
| // Android-changed: javadoc to throw on Android 14 or above. |
| /** |
| * Returns an AlgorithmParameterGenerator object for generating |
| * a set of parameters to be used with the specified algorithm. |
| * |
| * <p> A new AlgorithmParameterGenerator object encapsulating the |
| * AlgorithmParameterGeneratorSpi 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 name of the algorithm this |
| * parameter generator is associated with. |
| * |
| * @param provider the string name of the Provider. |
| * |
| * @return the new {@code AlgorithmParameterGenerator} object |
| * |
| * @throws IllegalArgumentException if the provider name is {@code null} |
| * or empty |
| * |
| * @throws NoSuchAlgorithmException if an |
| * {@code AlgorithmParameterGeneratorSpi} |
| * implementation for the specified algorithm is not |
| * available from the specified provider |
| * |
| * @throws NoSuchProviderException if the specified provider is not |
| * registered in the security provider list |
| * |
| * @throws NullPointerException if {@code algorithm} is {@code null} on Android 14 or above |
| * |
| * @see Provider |
| */ |
| public static AlgorithmParameterGenerator getInstance(String algorithm, |
| String provider) |
| throws NoSuchAlgorithmException, NoSuchProviderException |
| { |
| // Android-changed: To be compat with the older Android, don't throw NPE on Android 13-. |
| // Objects.requireNonNull(algorithm, "null algorithm name"); |
| if (VMRuntime.getSdkVersion() >= VersionCodes.UPSIDE_DOWN_CAKE) { |
| Objects.requireNonNull(algorithm, "null algorithm name"); |
| } |
| if (provider == null || provider.isEmpty()) |
| throw new IllegalArgumentException("missing provider"); |
| Object[] objs = Security.getImpl(algorithm, |
| "AlgorithmParameterGenerator", |
| provider); |
| return new AlgorithmParameterGenerator |
| ((AlgorithmParameterGeneratorSpi)objs[0], (Provider)objs[1], |
| algorithm); |
| } |
| |
| // Android-changed: javadoc to throw on Android 14 or above. |
| /** |
| * Returns an AlgorithmParameterGenerator object for generating |
| * a set of parameters to be used with the specified algorithm. |
| * |
| * <p> A new AlgorithmParameterGenerator object encapsulating the |
| * AlgorithmParameterGeneratorSpi 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 string name of the algorithm this |
| * parameter generator is associated with. |
| * |
| * @param provider the {@code Provider} object. |
| * |
| * @return the new {@code AlgorithmParameterGenerator} object |
| * |
| * @throws IllegalArgumentException if the specified provider is |
| * {@code null} |
| * |
| * @throws NoSuchAlgorithmException if an |
| * {@code AlgorithmParameterGeneratorSpi} |
| * implementation for the specified algorithm is not available |
| * from the specified {@code Provider} object |
| * |
| * @throws NullPointerException if {@code algorithm} is {@code null} on Android 14 or above |
| * |
| * @see Provider |
| * |
| * @since 1.4 |
| */ |
| public static AlgorithmParameterGenerator getInstance(String algorithm, |
| Provider provider) |
| throws NoSuchAlgorithmException |
| { |
| // Android-changed: To be compat with the older Android, don't throw NPE on Android 13-. |
| // Objects.requireNonNull(algorithm, "null algorithm name"); |
| if (VMRuntime.getSdkVersion() >= VersionCodes.UPSIDE_DOWN_CAKE) { |
| Objects.requireNonNull(algorithm, "null algorithm name"); |
| } |
| if (provider == null) |
| throw new IllegalArgumentException("missing provider"); |
| Object[] objs = Security.getImpl(algorithm, |
| "AlgorithmParameterGenerator", |
| provider); |
| return new AlgorithmParameterGenerator |
| ((AlgorithmParameterGeneratorSpi)objs[0], (Provider)objs[1], |
| algorithm); |
| } |
| |
| /** |
| * Returns the provider of this algorithm parameter generator object. |
| * |
| * @return the provider of this algorithm parameter generator object |
| */ |
| public final Provider getProvider() { |
| return this.provider; |
| } |
| |
| /** |
| * Initializes this parameter generator for a certain size. |
| * To create the parameters, the {@code SecureRandom} |
| * implementation of the highest-priority installed provider is used as |
| * the source of randomness. |
| * (If none of the installed providers supply an implementation of |
| * {@code SecureRandom}, a system-provided source of randomness is |
| * used.) |
| * |
| * @param size the size (number of bits). |
| */ |
| public final void init(int size) { |
| paramGenSpi.engineInit(size, new SecureRandom()); |
| } |
| |
| /** |
| * Initializes this parameter generator for a certain size and source |
| * of randomness. |
| * |
| * @param size the size (number of bits). |
| * @param random the source of randomness. |
| */ |
| public final void init(int size, SecureRandom random) { |
| paramGenSpi.engineInit(size, random); |
| } |
| |
| /** |
| * Initializes this parameter generator with a set of algorithm-specific |
| * parameter generation values. |
| * To generate the parameters, the {@code SecureRandom} |
| * implementation of the highest-priority installed provider is used as |
| * the source of randomness. |
| * (If none of the installed providers supply an implementation of |
| * {@code SecureRandom}, a system-provided source of randomness is |
| * used.) |
| * |
| * @param genParamSpec the set of algorithm-specific parameter generation values. |
| * |
| * @exception InvalidAlgorithmParameterException if the given parameter |
| * generation values are inappropriate for this parameter generator. |
| */ |
| public final void init(AlgorithmParameterSpec genParamSpec) |
| throws InvalidAlgorithmParameterException { |
| paramGenSpi.engineInit(genParamSpec, new SecureRandom()); |
| } |
| |
| /** |
| * Initializes this parameter generator with a set of algorithm-specific |
| * parameter generation values. |
| * |
| * @param genParamSpec the set of algorithm-specific parameter generation values. |
| * @param random the source of randomness. |
| * |
| * @exception InvalidAlgorithmParameterException if the given parameter |
| * generation values are inappropriate for this parameter generator. |
| */ |
| public final void init(AlgorithmParameterSpec genParamSpec, |
| SecureRandom random) |
| throws InvalidAlgorithmParameterException { |
| paramGenSpi.engineInit(genParamSpec, random); |
| } |
| |
| /** |
| * Generates the parameters. |
| * |
| * @return the new AlgorithmParameters object. |
| */ |
| public final AlgorithmParameters generateParameters() { |
| return paramGenSpi.engineGenerateParameters(); |
| } |
| } |
