| /* AlgorithmParameters.java --- Algorithm Parameters Implementation Class |
| Copyright (C) 1999, 2003, 2004 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package java.security; |
| |
| import gnu.java.security.Engine; |
| |
| import java.io.IOException; |
| import java.security.spec.AlgorithmParameterSpec; |
| import java.security.spec.InvalidParameterSpecException; |
| |
| /** |
| * <p>This class is used as an opaque representation of cryptographic |
| * parameters.</p> |
| * |
| * <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> |
| * |
| * <p>There are two ways to request such an implementation: by specifying |
| * either just an algorithm name, or both an algorithm name and a package |
| * provider.</p> |
| * |
| * <ul> |
| * <li>If just an algorithm name is specified, the system will determine if |
| * there is an AlgorithmParameters implementation for the algorithm requested |
| * available in the environment, and if there is more than one, if there is |
| * a preferred one.</li> |
| * <li>If both an algorithm name and a package provider are specified, the |
| * system will determine if there is an implementation in the package |
| * requested, and throw an exception if there is not.</li> |
| * </ul> |
| * |
| * <p>Once an <code>AlgorithmParameters</code> object is returned, it must be |
| * initialized via a call to <code>init()</code>, using an appropriate |
| * parameter specification or parameter encoding.</p> |
| * |
| * <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>.</p> |
| * |
| * @author Mark Benvenuto |
| * @since 1.2 |
| * @see AlgorithmParameterSpec |
| * @see java.security.spec.DSAParameterSpec |
| * @see KeyPairGenerator |
| */ |
| public class AlgorithmParameters |
| { |
| /** Service name for algorithm parameters. */ |
| private static final String ALGORITHM_PARAMETERS = "AlgorithmParameters"; |
| |
| private AlgorithmParametersSpi paramSpi; |
| private Provider provider; |
| private String algorithm; |
| |
| /** |
| * Creates an <code>AlgorithmParameters</code> 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 algorithm; |
| } |
| |
| /** |
| * <p>Generates a parameter object for the specified algorithm.</p> |
| * |
| * <p>If the default provider package provides an implementation of the |
| * requested algorithm, an instance of <code>AlgorithmParameters</code> |
| * containing that implementation is returned. If the algorithm is not |
| * available in the default package, other packages are searched.</p> |
| * |
| * <p>The returned parameter object must be initialized via a call to |
| * <code>init()</code>, using an appropriate parameter specification or |
| * parameter encoding.</p> |
| * |
| * @param algorithm the name of the algorithm requested. |
| * @return the new parameter object. |
| * @throws NoSuchAlgorithmException if the algorithm is not available in the |
| * environment. |
| */ |
| public static AlgorithmParameters getInstance(String algorithm) |
| throws NoSuchAlgorithmException |
| { |
| Provider[] p = Security.getProviders(); |
| |
| for (int i = 0; i < p.length; i++) |
| try |
| { |
| return getInstance(algorithm, p[i]); |
| } |
| catch (NoSuchAlgorithmException e) |
| { |
| // Ignore this. |
| } |
| |
| throw new NoSuchAlgorithmException(algorithm); |
| } |
| |
| /** |
| * <p>Generates a parameter object for the specified algorithm, as supplied |
| * by the specified provider, if such an algorithm is available from the |
| * provider.</p> |
| * |
| * <p>The returned parameter object must be initialized via a call to |
| * <code>init()</code>, using an appropriate parameter specification or |
| * parameter encoding.</p> |
| * |
| * @param algorithm the name of the algorithm requested. |
| * @param provider the name of the provider. |
| * @return the new parameter object. |
| * @throws NoSuchAlgorithmException if the algorithm is not available in the |
| * package supplied by the requested provider. |
| * @throws NoSuchProviderException if the provider is not available in the |
| * environment. |
| * @throws 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("Illegal provider"); |
| |
| Provider p = Security.getProvider(provider); |
| if (p == null) |
| throw new NoSuchProviderException(provider); |
| |
| return getInstance(algorithm, p); |
| } |
| |
| /** |
| * Generates an <code>AlgorithmParameterGenerator</code> object for the |
| * requested algorithm, as supplied from the specified provider, if such a |
| * parameter generator is available from the provider. Note: the |
| * <code>provider</code> doesn't have to be registered. |
| * |
| * @param algorithm the string name of the algorithm. |
| * @param provider the provider. |
| * @return the new <code>AlgorithmParameterGenerator</code> object. |
| * @throws NoSuchAlgorithmException if the <code>algorithm</code> is not |
| * available from the <code>provider</code>. |
| * @throws IllegalArgumentException if the <code>provider</code> is |
| * <code>null</code>. |
| * @since 1.4 |
| */ |
| public static AlgorithmParameters getInstance(String algorithm, |
| Provider provider) |
| throws NoSuchAlgorithmException |
| { |
| if (provider == null) |
| throw new IllegalArgumentException("Illegal provider"); |
| |
| try |
| { |
| return new AlgorithmParameters((AlgorithmParametersSpi) |
| Engine.getInstance(ALGORITHM_PARAMETERS, algorithm, provider), |
| provider, algorithm); |
| } |
| catch (java.lang.reflect.InvocationTargetException ite) |
| { |
| throw new NoSuchAlgorithmException(algorithm); |
| } |
| catch (ClassCastException cce) |
| { |
| throw new NoSuchAlgorithmException(algorithm); |
| } |
| } |
| |
| /** |
| * Returns the provider of this parameter object. |
| * |
| * @return the provider of this parameter object. |
| */ |
| public final Provider getProvider() |
| { |
| return provider; |
| } |
| |
| /** |
| * Initializes this parameter object using the parameters specified in |
| * <code>paramSpec</code>. |
| * |
| * @param paramSpec the parameter specification. |
| * @throws 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 |
| { |
| paramSpi.engineInit(paramSpec); |
| } |
| |
| /** |
| * 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. |
| * @throws IOException on decoding errors, or if this parameter object has |
| * already been initialized. |
| */ |
| public final void init(byte[]params) throws IOException |
| { |
| paramSpi.engineInit(params); |
| } |
| |
| /** |
| * Imports the parameters from params and decodes them according to the |
| * specified decoding scheme. If <code>format</code> is <code>null</code>, |
| * 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. |
| * @throws IOException on decoding errors, or if this parameter object has |
| * already been initialized. |
| */ |
| public final void init(byte[]params, String format) throws IOException |
| { |
| paramSpi.engineInit(params, format); |
| } |
| |
| /** |
| * 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 {@link java.security.spec.DSAParameterSpec} |
| * class. |
| * |
| * @param paramSpec the specification class in which the parameters should be |
| * returned. |
| * @return the parameter specification. |
| * @throws InvalidParameterSpecException if the requested parameter |
| * specification is inappropriate for this parameter object, or if this |
| * parameter object has not been initialized. |
| */ |
| public final AlgorithmParameterSpec getParameterSpec(Class paramSpec) |
| throws InvalidParameterSpecException |
| { |
| 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. |
| * @throws IOException on encoding errors, or if this parameter object has not |
| * been initialized. |
| */ |
| public final byte[] getEncoded() throws IOException |
| { |
| return paramSpi.engineGetEncoded(); |
| } |
| |
| /** |
| * Returns the parameters encoded in the specified scheme. If format is |
| * <code>null</code>, 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. |
| * @throws IOException on encoding errors, or if this parameter object has |
| * not been initialized. |
| */ |
| public final byte[] getEncoded(String format) throws IOException |
| { |
| return paramSpi.engineGetEncoded(format); |
| } |
| |
| /** |
| * Returns a formatted string describing the parameters. |
| * |
| * @return a formatted string describing the parameters, or <code>null</code> |
| * if this parameter object has not been initialized. |
| */ |
| public final String toString() |
| { |
| return paramSpi.engineToString(); |
| } |
| } |