001    /* ExemptionMechanismSpi.java -- Exemption mechanism service provider interface.
002       Copyright (C) 2004  Free Software Foundation, Inc.
003    
004    This file is part of GNU Classpath.
005    
006    GNU Classpath is free software; you can redistribute it and/or modify
007    it under the terms of the GNU General Public License as published by
008    the Free Software Foundation; either version 2, or (at your option)
009    any later version.
010    
011    GNU Classpath is distributed in the hope that it will be useful, but
012    WITHOUT ANY WARRANTY; without even the implied warranty of
013    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
014    General Public License for more details.
015    
016    You should have received a copy of the GNU General Public License
017    along with GNU Classpath; see the file COPYING.  If not, write to the
018    Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
019    02110-1301 USA.
020    
021    Linking this library statically or dynamically with other modules is
022    making a combined work based on this library.  Thus, the terms and
023    conditions of the GNU General Public License cover the whole
024    combination.
025    
026    As a special exception, the copyright holders of this library give you
027    permission to link this library with independent modules to produce an
028    executable, regardless of the license terms of these independent
029    modules, and to copy and distribute the resulting executable under
030    terms of your choice, provided that you also meet, for each linked
031    independent module, the terms and conditions of the license of that
032    module.  An independent module is a module which is not derived from
033    or based on this library.  If you modify this library, you may extend
034    this exception to your version of the library, but you are not
035    obligated to do so.  If you do not wish to do so, delete this
036    exception statement from your version. */
037    
038    
039    package javax.crypto;
040    
041    import java.security.AlgorithmParameters;
042    import java.security.InvalidAlgorithmParameterException;
043    import java.security.InvalidKeyException;
044    import java.security.Key;
045    import java.security.spec.AlgorithmParameterSpec;
046    
047    /**
048     * The <i>Service Provider Interface</i> (<b>SPI</b>) for the {@link
049     * ExemptionMechanism} class.
050     *
051     * @author Casey Marshall (csm@gnu.org)
052     * @since 1.4
053     */
054    public abstract class ExemptionMechanismSpi
055    {
056    
057      // Constructor.
058      // ------------------------------------------------------------------------
059    
060      /**
061       * Create a new exemption mechanism SPI.
062       */
063      public ExemptionMechanismSpi()
064      {
065      }
066    
067      // Abstract instance methods.
068      // ------------------------------------------------------------------------
069    
070      /**
071       * Return a key blob for the key that this mechanism was initialized
072       * with.
073       *
074       * @return The key blob.
075       * @throws javax.crypto.ExemptionMechanismException If generating the
076       *         blob fails.
077       */
078      protected abstract byte[] engineGenExemptionBlob()
079        throws ExemptionMechanismException;
080    
081      /**
082       * Generate a key blob for the key that this mechanism was initialized
083       * with, storing it into the given byte array.
084       *
085       * @param output       The destination for the key blob.
086       * @param outputOffset The index in the output array to start.
087       * @return The size of the key blob.
088       * @throws javax.crypto.ExemptionMechanismException If generating the
089       *         blob fails.
090       * @throws javax.crypto.ShortBufferException If the output array is
091       *         not large enough for the key blob.
092       */
093      protected abstract int engineGenExemptionBlob(byte[] output, int outputOffset)
094        throws ExemptionMechanismException, ShortBufferException;
095    
096      /**
097       * Get the size of the output blob given an input key size. The actual
098       * blob may be shorter than the value returned by this method. Both
099       * values are in bytes.
100       *
101       * @param inputLength The input size.
102       * @return The output size.
103       */
104      protected abstract int engineGetOutputSize(int inputLength);
105    
106      /**
107       * Initialize this mechanism with a key.
108       *
109       * @param key The key.
110       * @throws javax.crypto.ExemptionMechanismException If generating the
111       *         blob fails.
112       * @throws java.security.InvalidKeyException If the supplied key
113       *         cannot be used.
114       */
115      protected abstract void engineInit(Key key)
116        throws ExemptionMechanismException, InvalidKeyException;
117    
118      /**
119       * Initialize this mechanism with a key and parameters.
120       *
121       * @param key    The key.
122       * @param params The parameters.
123       * @throws javax.crypto.ExemptionMechanismException If generating the
124       *         blob fails.
125       * @throws java.security.InvalidAlgorithmParameterExceptin If the
126       *         supplied parameters are inappropriate.
127       * @throws java.security.InvalidKeyException If the supplied key
128       *         cannot be used.
129       */
130      protected abstract void engineInit(Key key, AlgorithmParameters params)
131        throws ExemptionMechanismException, InvalidAlgorithmParameterException,
132               InvalidKeyException;
133    
134      /**
135       * Initialize this mechanism with a key and parameters.
136       *
137       * @param key    The key.
138       * @param params The parameters.
139       * @throws javax.crypto.ExemptionMechanismException If generating the
140       *         blob fails.
141       * @throws java.security.InvalidAlgorithmParameterExceptin If the
142       *         supplied parameters are inappropriate.
143       * @throws java.security.InvalidKeyException If the supplied key
144       *         cannot be used.
145       */
146      protected abstract void engineInit(Key key, AlgorithmParameterSpec params)
147        throws ExemptionMechanismException, InvalidAlgorithmParameterException,
148               InvalidKeyException;
149    }