jdk/src/share/classes/java/security/AlgorithmParameters.java
changeset 2 90ce3da70b43
child 5506 202f599c92aa
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/java/security/AlgorithmParameters.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,382 @@
+/*
+ * Copyright 1997-2006 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package java.security;
+
+import java.io.*;
+import java.security.spec.AlgorithmParameterSpec;
+import java.security.spec.InvalidParameterSpecException;
+
+/**
+ * This class is used as an opaque representation of cryptographic parameters.
+ *
+ * <p>An <code>AlgorithmParameters</code> object for managing the parameters
+ * for a particular algorithm can be obtained by
+ * calling one of the <code>getInstance</code> factory methods
+ * (static methods that return instances of a given class).
+ *
+ * <p>Once an <code>AlgorithmParameters</code> object is obtained, it must be
+ * initialized via a call to <code>init</code>, using an appropriate parameter
+ * specification or parameter encoding.
+ *
+ * <p>A transparent parameter specification is obtained from an
+ * <code>AlgorithmParameters</code> object via a call to
+ * <code>getParameterSpec</code>, and a byte encoding of the parameters is
+ * obtained via a call to <code>getEncoded</code>.
+ *
+ * @author Jan Luehe
+ *
+ *
+ * @see java.security.spec.AlgorithmParameterSpec
+ * @see java.security.spec.DSAParameterSpec
+ * @see KeyPairGenerator
+ *
+ * @since 1.2
+ */
+
+public class AlgorithmParameters {
+
+    // The provider
+    private Provider provider;
+
+    // The provider implementation (delegate)
+    private AlgorithmParametersSpi paramSpi;
+
+    // The algorithm
+    private String algorithm;
+
+    // Has this object been initialized?
+    private boolean initialized = false;
+
+    /**
+     * Creates an AlgorithmParameters object.
+     *
+     * @param paramSpi the delegate
+     * @param provider the provider
+     * @param algorithm the algorithm
+     */
+    protected AlgorithmParameters(AlgorithmParametersSpi paramSpi,
+                                  Provider provider, String algorithm)
+    {
+        this.paramSpi = paramSpi;
+        this.provider = provider;
+        this.algorithm = algorithm;
+    }
+
+    /**
+     * Returns the name of the algorithm associated with this parameter object.
+     *
+     * @return the algorithm name.
+     */
+    public final String getAlgorithm() {
+        return this.algorithm;
+    }
+
+    /**
+     * Returns a parameter object for the specified algorithm.
+     *
+     * <p> This method traverses the list of registered security Providers,
+     * starting with the most preferred Provider.
+     * A new AlgorithmParameters object encapsulating the
+     * AlgorithmParametersSpi 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.
+     *
+     * <p> The returned parameter object must be initialized via a call to
+     * <code>init</code>, using an appropriate parameter specification or
+     * parameter encoding.
+     *
+     * @param algorithm the name of the algorithm requested.
+     * See Appendix A in the <a href=
+     * "../../../technotes/guides/security/crypto/CryptoSpec.html#AppA">
+     * Java Cryptography Architecture API Specification &amp; Reference </a>
+     * for information about standard algorithm names.
+     *
+     * @return the new parameter object.
+     *
+     * @exception NoSuchAlgorithmException if no Provider supports an
+     *          AlgorithmParametersSpi implementation for the
+     *          specified algorithm.
+     *
+     * @see Provider
+     */
+    public static AlgorithmParameters getInstance(String algorithm)
+    throws NoSuchAlgorithmException {
+        try {
+            Object[] objs = Security.getImpl(algorithm, "AlgorithmParameters",
+                                             (String)null);
+            return new AlgorithmParameters((AlgorithmParametersSpi)objs[0],
+                                           (Provider)objs[1],
+                                           algorithm);
+        } catch(NoSuchProviderException e) {
+            throw new NoSuchAlgorithmException(algorithm + " not found");
+        }
+    }
+
+    /**
+     * Returns a parameter object for the specified algorithm.
+     *
+     * <p> A new AlgorithmParameters object encapsulating the
+     * AlgorithmParametersSpi 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.
+     *
+     * <p>The returned parameter object must be initialized via a call to
+     * <code>init</code>, using an appropriate parameter specification or
+     * parameter encoding.
+     *
+     * @param algorithm the name of the algorithm requested.
+     * See Appendix A in the <a href=
+     * "../../../technotes/guides/security/crypto/CryptoSpec.html#AppA">
+     * Java Cryptography Architecture API Specification &amp; Reference </a>
+     * for information about standard algorithm names.
+     *
+     * @param provider the name of the provider.
+     *
+     * @return the new parameter object.
+     *
+     * @exception NoSuchAlgorithmException if an AlgorithmParametersSpi
+     *          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 name is null
+     *          or empty.
+     *
+     * @see Provider
+     */
+    public static AlgorithmParameters getInstance(String algorithm,
+                                                  String provider)
+        throws NoSuchAlgorithmException, NoSuchProviderException
+    {
+        if (provider == null || provider.length() == 0)
+            throw new IllegalArgumentException("missing provider");
+        Object[] objs = Security.getImpl(algorithm, "AlgorithmParameters",
+                                         provider);
+        return new AlgorithmParameters((AlgorithmParametersSpi)objs[0],
+                                       (Provider)objs[1],
+                                       algorithm);
+    }
+
+    /**
+     * Returns a parameter object for the specified algorithm.
+     *
+     * <p> A new AlgorithmParameters object encapsulating the
+     * AlgorithmParametersSpi implementation from the specified Provider
+     * object is returned.  Note that the specified Provider object
+     * does not have to be registered in the provider list.
+     *
+     * <p>The returned parameter object must be initialized via a call to
+     * <code>init</code>, using an appropriate parameter specification or
+     * parameter encoding.
+     *
+     * @param algorithm the name of the algorithm requested.
+     * See Appendix A in the <a href=
+     * "../../../technotes/guides/security/crypto/CryptoSpec.html#AppA">
+     * Java Cryptography Architecture API Specification &amp; Reference </a>
+     * for information about standard algorithm names.
+     *
+     * @param provider the name of the provider.
+     *
+     * @return the new parameter object.
+     *
+     * @exception NoSuchAlgorithmException if an AlgorithmParameterGeneratorSpi
+     *          implementation for the specified algorithm is not available
+     *          from the specified Provider object.
+     *
+     * @exception IllegalArgumentException if the provider is null.
+     *
+     * @see Provider
+     *
+     * @since 1.4
+     */
+    public static AlgorithmParameters getInstance(String algorithm,
+                                                  Provider provider)
+        throws NoSuchAlgorithmException
+    {
+        if (provider == null)
+            throw new IllegalArgumentException("missing provider");
+        Object[] objs = Security.getImpl(algorithm, "AlgorithmParameters",
+                                         provider);
+        return new AlgorithmParameters((AlgorithmParametersSpi)objs[0],
+                                       (Provider)objs[1],
+                                       algorithm);
+    }
+
+    /**
+     * Returns the provider of this parameter object.
+     *
+     * @return the provider of this parameter object
+     */
+    public final Provider getProvider() {
+        return this.provider;
+    }
+
+    /**
+     * Initializes this parameter object using the parameters
+     * specified in <code>paramSpec</code>.
+     *
+     * @param paramSpec the parameter specification.
+     *
+     * @exception InvalidParameterSpecException if the given parameter
+     * specification is inappropriate for the initialization of this parameter
+     * object, or if this parameter object has already been initialized.
+     */
+    public final void init(AlgorithmParameterSpec paramSpec)
+        throws InvalidParameterSpecException
+    {
+        if (this.initialized)
+            throw new InvalidParameterSpecException("already initialized");
+        paramSpi.engineInit(paramSpec);
+        this.initialized = true;
+    }
+
+    /**
+     * Imports the specified parameters and decodes them according to the
+     * primary decoding format for parameters. The primary decoding
+     * format for parameters is ASN.1, if an ASN.1 specification for this type
+     * of parameters exists.
+     *
+     * @param params the encoded parameters.
+     *
+     * @exception IOException on decoding errors, or if this parameter object
+     * has already been initialized.
+     */
+    public final void init(byte[] params) throws IOException {
+        if (this.initialized)
+            throw new IOException("already initialized");
+        paramSpi.engineInit(params);
+        this.initialized = true;
+    }
+
+    /**
+     * Imports the parameters from <code>params</code> and decodes them
+     * according to the specified decoding scheme.
+     * If <code>format</code> is null, the
+     * primary decoding format for parameters is used. The primary decoding
+     * format is ASN.1, if an ASN.1 specification for these parameters
+     * exists.
+     *
+     * @param params the encoded parameters.
+     *
+     * @param format the name of the decoding scheme.
+     *
+     * @exception IOException on decoding errors, or if this parameter object
+     * has already been initialized.
+     */
+    public final void init(byte[] params, String format) throws IOException {
+        if (this.initialized)
+            throw new IOException("already initialized");
+        paramSpi.engineInit(params, format);
+        this.initialized = true;
+    }
+
+    /**
+     * Returns a (transparent) specification of this parameter object.
+     * <code>paramSpec</code> identifies the specification class in which
+     * the parameters should be returned. It could, for example, be
+     * <code>DSAParameterSpec.class</code>, to indicate that the
+     * parameters should be returned in an instance of the
+     * <code>DSAParameterSpec</code> class.
+     *
+     * @param paramSpec the specification class in which
+     * the parameters should be returned.
+     *
+     * @return the parameter specification.
+     *
+     * @exception InvalidParameterSpecException if the requested parameter
+     * specification is inappropriate for this parameter object, or if this
+     * parameter object has not been initialized.
+     */
+    public final <T extends AlgorithmParameterSpec>
+        T getParameterSpec(Class<T> paramSpec)
+        throws InvalidParameterSpecException
+    {
+        if (this.initialized == false) {
+            throw new InvalidParameterSpecException("not initialized");
+        }
+        return paramSpi.engineGetParameterSpec(paramSpec);
+    }
+
+    /**
+     * Returns the parameters in their primary encoding format.
+     * The primary encoding format for parameters is ASN.1, if an ASN.1
+     * specification for this type of parameters exists.
+     *
+     * @return the parameters encoded using their primary encoding format.
+     *
+     * @exception IOException on encoding errors, or if this parameter object
+     * has not been initialized.
+     */
+    public final byte[] getEncoded() throws IOException
+    {
+        if (this.initialized == false) {
+            throw new IOException("not initialized");
+        }
+        return paramSpi.engineGetEncoded();
+    }
+
+    /**
+     * Returns the parameters encoded in the specified scheme.
+     * If <code>format</code> is null, the
+     * primary encoding format for parameters is used. The primary encoding
+     * format is ASN.1, if an ASN.1 specification for these parameters
+     * exists.
+     *
+     * @param format the name of the encoding format.
+     *
+     * @return the parameters encoded using the specified encoding scheme.
+     *
+     * @exception IOException on encoding errors, or if this parameter object
+     * has not been initialized.
+     */
+    public final byte[] getEncoded(String format) throws IOException
+    {
+        if (this.initialized == false) {
+            throw new IOException("not initialized");
+        }
+        return paramSpi.engineGetEncoded(format);
+    }
+
+    /**
+     * Returns a formatted string describing the parameters.
+     *
+     * @return a formatted string describing the parameters, or null if this
+     * parameter object has not been initialized.
+     */
+    public final String toString() {
+        if (this.initialized == false) {
+            return null;
+        }
+        return paramSpi.engineToString();
+    }
+}