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Diffstat (limited to 'libjava/classpath/java/security/AlgorithmParameters.java')
| -rw-r--r-- | libjava/classpath/java/security/AlgorithmParameters.java | 340 |
1 files changed, 340 insertions, 0 deletions
diff --git a/libjava/classpath/java/security/AlgorithmParameters.java b/libjava/classpath/java/security/AlgorithmParameters.java new file mode 100644 index 00000000000..038fbb4bd64 --- /dev/null +++ b/libjava/classpath/java/security/AlgorithmParameters.java @@ -0,0 +1,340 @@ +/* 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., 51 Franklin Street, Fifth Floor, Boston, MA +02110-1301 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(); + } +} |
