--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/security/AlgorithmParameterGenerator.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,369 @@
+/*
+ * 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 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.
+ * See the Keysize Restriction sections of the
+ * {@extLink security_guide_jdk_providers JDK Providers}
+ * document for information on the AlgorithmParameterGenerator defaults
+ * used by JDK providers.
+ * 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> Every implementation of the Java platform is required to support the
+ * following standard {@code AlgorithmParameterGenerator} algorithms and
+ * keysizes in parentheses:
+ * <ul>
+ * <li>{@code DiffieHellman} (1024, 2048)</li>
+ * <li>{@code DSA} (1024, 2048)</li>
+ * </ul>
+ * These algorithms are described in the <a href=
+ * "{@docRoot}/../specs/security/standard-names.html#algorithmparametergenerator-algorithms">
+ * AlgorithmParameterGenerator section</a> of the
+ * Java Security Standard Algorithm Names Specification.
+ * Consult the release documentation for your implementation to see if any
+ * other algorithms are supported.
+ *
+ * @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;
+ }
+
+ /**
+ * 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.
+ *
+ * @implNote
+ * The JDK Reference Implementation additionally uses the
+ * {@code jdk.security.provider.preferred}
+ * {@link Security#getProperty(String) Security} property to determine
+ * the preferred provider order for the specified algorithm. This
+ * may be different than the order of providers returned by
+ * {@link Security#getProviders() Security.getProviders()}.
+ *
+ * @param algorithm the name of the algorithm this
+ * parameter generator is associated with.
+ * See the AlgorithmParameterGenerator section in the <a href=
+ * "{@docRoot}/../specs/security/standard-names.html#algorithmparametergenerator-algorithms">
+ * Java Security Standard Algorithm Names Specification</a>
+ * for information about standard algorithm names.
+ *
+ * @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}
+ *
+ * @see Provider
+ */
+ public static AlgorithmParameterGenerator getInstance(String algorithm)
+ throws NoSuchAlgorithmException {
+ 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");
+ }
+ }
+
+ /**
+ * 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.
+ * See the AlgorithmParameterGenerator section in the <a href=
+ * "{@docRoot}/../specs/security/standard-names.html#algorithmparametergenerator-algorithms">
+ * Java Security Standard Algorithm Names Specification</a>
+ * for information about standard algorithm names.
+ *
+ * @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}
+ *
+ * @see Provider
+ */
+ public static AlgorithmParameterGenerator getInstance(String algorithm,
+ String provider)
+ throws NoSuchAlgorithmException, NoSuchProviderException
+ {
+ Objects.requireNonNull(algorithm, "null algorithm name");
+ if (provider == null || provider.length() == 0)
+ throw new IllegalArgumentException("missing provider");
+ Object[] objs = Security.getImpl(algorithm,
+ "AlgorithmParameterGenerator",
+ provider);
+ return new AlgorithmParameterGenerator
+ ((AlgorithmParameterGeneratorSpi)objs[0], (Provider)objs[1],
+ algorithm);
+ }
+
+ /**
+ * 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.
+ * See the AlgorithmParameterGenerator section in the <a href=
+ * "{@docRoot}/../specs/security/standard-names.html#algorithmparametergenerator-algorithms">
+ * Java Security Standard Algorithm Names Specification</a>
+ * for information about standard algorithm names.
+ *
+ * @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}
+ *
+ * @see Provider
+ *
+ * @since 1.4
+ */
+ public static AlgorithmParameterGenerator getInstance(String algorithm,
+ Provider provider)
+ throws NoSuchAlgorithmException
+ {
+ 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();
+ }
+}