| /* AlgorithmParameterGenerator.java --- Algorithm Parameter Generator |
| Copyright (C) 1999 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 java.security.spec.AlgorithmParameterSpec; |
| |
| /** |
| AlgorithmParameterGenerator is used to generate |
| algorithm parameters for specified algorithms. |
| This class is used to generate the algorithm parameters |
| for a specific algorithm. |
| |
| @since JDK 1.2 |
| @author Mark Benvenuto |
| */ |
| public class AlgorithmParameterGenerator |
| { |
| private AlgorithmParameterGeneratorSpi paramGenSpi; |
| private Provider provider; |
| private String algorithm; |
| |
| /** |
| Creates an instance of AlgorithmParameters |
| |
| @param paramSpi A parameters engine to use |
| @param provider A provider to use |
| @param algorithm The algorithm |
| */ |
| protected AlgorithmParameterGenerator(AlgorithmParameterGeneratorSpi |
| paramGenSpi, Provider provider, |
| String algorithm) |
| { |
| this.paramGenSpi = paramGenSpi; |
| this.provider = provider; |
| this.algorithm = algorithm; |
| } |
| |
| /** |
| Returns the name of the algorithm used |
| |
| @return A string with the name of the algorithm |
| */ |
| public final String getAlgorithm() |
| { |
| return algorithm; |
| } |
| |
| /** |
| Gets an instance of the AlgorithmParameterGenerator class |
| which generates algorithm parameters for the specified algorithm. |
| If the algorithm is not found then, it throws NoSuchAlgorithmException. |
| |
| @param algorithm the name of algorithm to choose |
| @return a AlgorithmParameterGenerator repesenting the desired algorithm |
| |
| @throws NoSuchAlgorithmException if the algorithm is not implemented by providers |
| */ |
| public static AlgorithmParameterGenerator getInstance(String algorithm) |
| throws NoSuchAlgorithmException |
| { |
| Provider[] p = Security.getProviders(); |
| |
| for (int i = 0; i < p.length; i++) |
| { |
| String classname = |
| p[i].getProperty("AlgorithmParameterGenerator." + algorithm); |
| if (classname != null) |
| return getInstance(classname, algorithm, p[i]); |
| } |
| |
| throw new NoSuchAlgorithmException(algorithm); |
| } |
| |
| /** |
| Gets an instance of the AlgorithmParameterGenerator class |
| which generates algorithm parameters for the specified algorithm. |
| If the algorithm is not found then, it throws NoSuchAlgorithmException. |
| |
| @param algorithm the name of algorithm to choose |
| @param provider the name of the provider to find the algorithm in |
| @return a AlgorithmParameterGenerator repesenting the desired algorithm |
| |
| @throws NoSuchAlgorithmException if the algorithm is not implemented by the provider |
| @throws NoSuchProviderException if the provider is not found |
| */ |
| public static AlgorithmParameterGenerator getInstance(String algorithm, |
| String provider) |
| throws NoSuchAlgorithmException, NoSuchProviderException |
| { |
| Provider p = Security.getProvider(provider); |
| if (p == null) |
| throw new NoSuchProviderException(); |
| |
| return getInstance(p. |
| getProperty("AlgorithmParameterGenerator." + |
| algorithm), algorithm, p); |
| } |
| |
| private static AlgorithmParameterGenerator getInstance(String classname, |
| String algorithm, |
| Provider provider) |
| throws NoSuchAlgorithmException |
| { |
| |
| try |
| { |
| return new |
| AlgorithmParameterGenerator((AlgorithmParameterGeneratorSpi) Class. |
| forName(classname).newInstance(), |
| provider, algorithm); |
| } |
| catch (ClassNotFoundException cnfe) |
| { |
| throw new NoSuchAlgorithmException("Class not found"); |
| } |
| catch (InstantiationException ie) |
| { |
| throw new NoSuchAlgorithmException("Class instantiation failed"); |
| } |
| catch (IllegalAccessException iae) |
| { |
| throw new NoSuchAlgorithmException("Illegal Access"); |
| } |
| } |
| |
| /** |
| Gets the provider that the class is from. |
| |
| @return the provider of this class |
| */ |
| public final Provider getProvider() |
| { |
| return provider; |
| } |
| |
| /** |
| Initializes the Algorithm Parameter Generator with the specified |
| size. (Since no source of randomness is supplied, a default |
| one is supplied). |
| |
| @param size size (in bits) to use |
| */ |
| public final void init(int size) |
| { |
| init(size, new SecureRandom()); |
| } |
| |
| /** |
| Initializes the Algorithm Parameter Generator with the specified |
| size and source of randomness. |
| |
| @param size size (in bits) to use |
| @param random source of randomness to use |
| */ |
| public final void init(int size, SecureRandom random) |
| { |
| paramGenSpi.engineInit(size, random); |
| } |
| |
| /** |
| Initializes the Algorithm Parameter Generator with the specified |
| AlgorithmParameterSpec. (Since no source of randomness is supplied, |
| a default one is supplied). |
| |
| @param genParamSpec the AlgorithmParameterSpec class to use |
| */ |
| public final void init(AlgorithmParameterSpec genParamSpec) throws |
| InvalidAlgorithmParameterException |
| { |
| init(genParamSpec, new SecureRandom()); |
| } |
| |
| /** |
| Initializes the Algorithm Parameter Generator with the specified |
| AlgorithmParameterSpec and source of randomness. |
| |
| @param genParamSpec the AlgorithmParameterSpec class to use |
| @param random source of randomness to use |
| */ |
| public final void init(AlgorithmParameterSpec genParamSpec, |
| SecureRandom random) throws |
| InvalidAlgorithmParameterException |
| { |
| paramGenSpi.engineInit(genParamSpec, random); |
| } |
| |
| /** |
| Generate a new set of AlgorithmParameters. |
| |
| @returns a new set of algorithm parameters |
| */ |
| public final AlgorithmParameters generateParameters() |
| { |
| return paramGenSpi.engineGenerateParameters(); |
| } |
| } |