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Diffstat (limited to 'libjava/java/security/Engine.java')
| -rw-r--r-- | libjava/java/security/Engine.java | 152 |
1 files changed, 0 insertions, 152 deletions
diff --git a/libjava/java/security/Engine.java b/libjava/java/security/Engine.java deleted file mode 100644 index 88ff536..0000000 --- a/libjava/java/security/Engine.java +++ /dev/null @@ -1,152 +0,0 @@ -/* Engine -- generic getInstance method. - Copyright (C) 2003 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; - -/** - * Generic implementation of the getInstance methods in the various - * engine classes in java.security. - * <p> - * These classes ({@link java.security.Signature} for example) can be - * thought of as the "chrome, upholstery, and steering wheel", and the SPI - * (service provider interface, e.g. {@link java.security.SignatureSpi}) - * classes can be thought of as the "engine" -- providing the actual - * functionality of whatever cryptographic algorithm the instance - * represents. - * - * @see Provider - * @author Casey Marshall - */ -final class Engine -{ - - // Constants. - // ------------------------------------------------------------------------ - - /** Prefix for aliases. */ - private static final String ALG_ALIAS = "Alg.Alias."; - - /** Maximum number of aliases to try. */ - private static final int MAX_ALIASES = 5; - - // Constructor. - // ------------------------------------------------------------------------ - - /** This class cannot be instantiated. */ - private Engine() { } - - // Class method. - // ------------------------------------------------------------------------ - - /** - * Get the implementation for <i>algorithm</i> for service - * <i>service</i> from <i>provider</i>. The service is e.g. - * "Signature", and the algorithm "DSA". - * - * @param service The service name. - * @param algorithm The name of the algorithm to get. - * @param provider The provider to get the implementation from. - * @return The engine class for the specified algorithm; the object - * returned is typically a subclass of the SPI class for that - * service, but callers should check that this is so. - * @throws NoSuchAlgorithmException If the implementation cannot be - * found or cannot be instantiated. - * @throws IllegalArgumentException If any of the three arguments are null. - */ - static Object - getInstance(String service, String algorithm, Provider provider) - throws NoSuchAlgorithmException - { - if (service == null || algorithm == null || provider == null) - throw new IllegalArgumentException(); - - // If there is no property "service.algorithm" - if (provider.getProperty(service + "." + algorithm) == null) - { - // Iterate through aliases, until we find the class name or resolve - // too many aliases. - String alias = null; - int count = 0; - while ((alias = provider.getProperty( - ALG_ALIAS + service + "." + algorithm)) != null) - { - if (algorithm.equals(alias)) // Refers to itself! - break; - algorithm = alias; - if (count++ > MAX_ALIASES) - throw new NoSuchAlgorithmException("too many aliases"); - } - if (provider.getProperty(service + "." + algorithm) == null) - throw new NoSuchAlgorithmException(algorithm); - } - - // Find and instantiate the implementation. - Class clazz = null; - ClassLoader loader = provider.getClass().getClassLoader(); - String error = algorithm; - try - { - if (loader != null) - clazz = loader.loadClass(provider.getProperty(service+"."+algorithm)); - else - clazz = Class.forName(provider.getProperty(service+"."+algorithm)); - return clazz.newInstance(); - } - catch (ClassNotFoundException cnfe) - { - error = "class not found: " + algorithm; - } - catch (IllegalAccessException iae) - { - error = "illegal access: " + iae.getMessage(); - } - catch (InstantiationException ie) - { - error = "instantiation exception: " + ie.getMessage(); - } - catch (ExceptionInInitializerError eiie) - { - error = "exception in initializer: " + eiie.getMessage(); - } - catch (SecurityException se) - { - error = "security exception: " + se.getMessage(); - } - - throw new NoSuchAlgorithmException(error); - } -} |