| /* ExemptionMechanism.java -- Generic crypto-weakening mechanism. |
| Copyright (C) 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 javax.crypto; |
| |
| import gnu.java.security.Engine; |
| |
| import java.lang.reflect.InvocationTargetException; |
| import java.security.AlgorithmParameters; |
| import java.security.InvalidAlgorithmParameterException; |
| import java.security.InvalidKeyException; |
| import java.security.Key; |
| import java.security.NoSuchAlgorithmException; |
| import java.security.NoSuchProviderException; |
| import java.security.Provider; |
| import java.security.Security; |
| import java.security.spec.AlgorithmParameterSpec; |
| |
| /** |
| * An exemption mechanism, which will conditionally allow cryptography |
| * where it is not normally allowed, implements things such as <i>key |
| * recovery</i>, <i>key weakening</i>, or <i>key escrow</i>. |
| * |
| * <p><b>Implementation note</b>: this class is present for |
| * API-compatibility only; it is not actually used anywhere in this library |
| * and this library does not, in general, support crypto weakening. |
| * |
| * @author Casey Marshall (csm@gnu.org) |
| * @since 1.4 |
| */ |
| public class ExemptionMechanism |
| { |
| |
| // Constants and fields. |
| // ------------------------------------------------------------------------ |
| |
| private static final String SERVICE = "ExemptionMechanism"; |
| private ExemptionMechanismSpi emSpi; |
| private Provider provider; |
| private String mechanism; |
| private boolean virgin; |
| |
| // Constructor. |
| // ------------------------------------------------------------------------ |
| |
| protected ExemptionMechanism(ExemptionMechanismSpi emSpi, Provider provider, |
| String mechanism) |
| { |
| this.emSpi = emSpi; |
| this.provider = provider; |
| this.mechanism = mechanism; |
| virgin = true; |
| } |
| |
| // Class methods. |
| // ------------------------------------------------------------------------ |
| |
| public static final ExemptionMechanism getInstance(String mechanism) |
| throws NoSuchAlgorithmException |
| { |
| Provider[] provs = Security.getProviders(); |
| String msg = ""; |
| for (int i = 0; i < provs.length; i++) |
| { |
| try |
| { |
| return getInstance(mechanism, provs[i]); |
| } |
| catch (NoSuchAlgorithmException nsae) |
| { |
| msg = nsae.getMessage(); |
| } |
| } |
| throw new NoSuchAlgorithmException(msg); |
| } |
| |
| public static final ExemptionMechanism getInstance(String mechanism, |
| String provider) |
| throws NoSuchAlgorithmException, NoSuchProviderException |
| { |
| Provider p = Security.getProvider(provider); |
| if (p == null) |
| { |
| throw new NoSuchProviderException(provider); |
| } |
| return getInstance(mechanism, p); |
| } |
| |
| public static final ExemptionMechanism getInstance(String mechanism, |
| Provider provider) |
| throws NoSuchAlgorithmException |
| { |
| try |
| { |
| return new ExemptionMechanism((ExemptionMechanismSpi) |
| Engine.getInstance(SERVICE, mechanism, provider), |
| provider, mechanism); |
| } |
| catch (InvocationTargetException ite) |
| { |
| if (ite.getCause() instanceof NoSuchAlgorithmException) |
| throw (NoSuchAlgorithmException) ite.getCause(); |
| else |
| throw new NoSuchAlgorithmException(mechanism); |
| } |
| catch (ClassCastException cce) |
| { |
| throw new NoSuchAlgorithmException(mechanism); |
| } |
| } |
| |
| // Instance methods. |
| // ------------------------------------------------------------------------ |
| |
| public final byte[] genExemptionBlob() |
| throws IllegalStateException, ExemptionMechanismException |
| { |
| if (virgin) |
| { |
| throw new IllegalStateException("not initialized"); |
| } |
| return emSpi.engineGenExemptionBlob(); |
| } |
| |
| public final int genExemptionBlob(byte[] output) |
| throws IllegalStateException, ExemptionMechanismException, |
| ShortBufferException |
| { |
| return genExemptionBlob(output, 0); |
| } |
| |
| public final int genExemptionBlob(byte[] output, int outputOffset) |
| throws IllegalStateException, ExemptionMechanismException, |
| ShortBufferException |
| { |
| if (virgin) |
| { |
| throw new IllegalStateException("not initialized"); |
| } |
| return emSpi.engineGenExemptionBlob(output, outputOffset); |
| } |
| |
| public final String getName() |
| { |
| return mechanism; |
| } |
| |
| public final int getOutputSize(int inputLength) throws IllegalStateException |
| { |
| if (virgin) |
| { |
| throw new IllegalStateException("not initialized"); |
| } |
| return emSpi.engineGetOutputSize(inputLength); |
| } |
| |
| public final Provider getProvider() |
| { |
| return provider; |
| } |
| |
| public final void init(Key key) |
| throws ExemptionMechanismException, InvalidKeyException |
| { |
| emSpi.engineInit(key); |
| virgin = false; |
| } |
| |
| public final void init(Key key, AlgorithmParameters params) |
| throws ExemptionMechanismException, InvalidAlgorithmParameterException, |
| InvalidKeyException |
| { |
| emSpi.engineInit(key, params); |
| virgin = false; |
| } |
| |
| public final void init(Key key, AlgorithmParameterSpec params) |
| throws ExemptionMechanismException, InvalidAlgorithmParameterException, |
| InvalidKeyException |
| { |
| emSpi.engineInit(key, params); |
| virgin = false; |
| } |
| |
| public final boolean isCryptoAllowed(Key key) |
| throws ExemptionMechanismException |
| { |
| return true; |
| } |
| |
| protected void finalize() |
| { |
| } |
| } |