| /* BaseKeyWrappingAlgorithm.java -- FIXME: briefly describe file purpose |
| Copyright (C) 2006 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 gnu.javax.crypto.kwa; |
| |
| import gnu.java.security.util.PRNG; |
| |
| import java.security.InvalidKeyException; |
| import java.util.Collections; |
| import java.util.Map; |
| |
| import javax.crypto.ShortBufferException; |
| |
| /** |
| * A base class to facilitate implementation of concrete Key Wrapping |
| * Algorithms. |
| */ |
| public abstract class BaseKeyWrappingAlgorithm |
| implements IKeyWrappingAlgorithm |
| { |
| /** The canonical name of the key wrapping algorithm. */ |
| protected String name; |
| /** A source of randomness if/when needed by concrete implementations. */ |
| private PRNG prng; |
| |
| /** |
| * Protected constructor. |
| * |
| * @param name the key wrapping algorithm canonical name. |
| */ |
| protected BaseKeyWrappingAlgorithm(String name) |
| { |
| super(); |
| } |
| |
| public String name() |
| { |
| return this.name; |
| } |
| |
| public void init(Map attributes) throws InvalidKeyException |
| { |
| if (attributes == null) |
| attributes = Collections.EMPTY_MAP; |
| |
| engineInit(attributes); |
| } |
| |
| public int wrap(byte[] in, int inOffset, int length, byte[] out, int outOffset) |
| throws ShortBufferException |
| { |
| if (outOffset < 0) |
| throw new IllegalArgumentException("Output offset MUST NOT be negative"); |
| byte[] result = wrap(in, inOffset, length); |
| if (outOffset + result.length > out.length) |
| throw new ShortBufferException(); |
| System.arraycopy(result, 0, out, outOffset, result.length); |
| return result.length; |
| } |
| |
| public byte[] wrap(byte[] in, int inOffset, int length) |
| { |
| if (inOffset < 0) |
| throw new IllegalArgumentException("Input offset MUST NOT be negative"); |
| if (length < 0) |
| throw new IllegalArgumentException("Input length MUST NOT be negative"); |
| |
| return engineWrap(in, inOffset, length); |
| } |
| |
| public int unwrap(byte[] in, int inOffset, int length, |
| byte[] out, int outOffset) |
| throws ShortBufferException, KeyUnwrappingException |
| { |
| if (outOffset < 0) |
| throw new IllegalArgumentException("Output offset MUST NOT be negative"); |
| byte[] result = engineUnwrap(in, inOffset, length); |
| if (outOffset + result.length > out.length) |
| throw new ShortBufferException(); |
| System.arraycopy(result, 0, out, outOffset, result.length); |
| return result.length; |
| } |
| |
| public byte[] unwrap(byte[] in, int inOffset, int length) |
| throws KeyUnwrappingException |
| { |
| if (inOffset < 0) |
| throw new IllegalArgumentException("Input offset MUST NOT be negative"); |
| if (length < 0) |
| throw new IllegalArgumentException("Input length MUST NOT be negative"); |
| |
| return engineUnwrap(in, inOffset, length); |
| } |
| |
| protected abstract void engineInit(Map attributes) throws InvalidKeyException; |
| |
| protected abstract byte[] engineWrap(byte[] in, int inOffset, int length); |
| |
| protected abstract byte[] engineUnwrap(byte[] in, int inOffset, int length) |
| throws KeyUnwrappingException; |
| |
| /** @return a strong pseudo-random number generator if/when needed. */ |
| protected PRNG getDefaultPRNG() |
| { |
| if (prng == null) |
| prng = PRNG.getInstance(); |
| |
| return prng; |
| } |
| } |