package gnu.crypto.assembly;
// ----------------------------------------------------------------------------
// $Id: ModeStage.java,v 1.3 2005/10/06 04:24:13 rsdio Exp $
//
// Copyright (C) 2003, Free Software Foundation, Inc.
//
// This file is part of GNU Crypto.
//
// GNU Crypto 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 Crypto 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 this program; 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.
// ----------------------------------------------------------------------------
import gnu.crypto.mode.IMode;
import java.security.InvalidKeyException;
import java.util.Collections;
import java.util.HashSet;
import java.util.Iterator;
import java.util.Map;
import java.util.Set;
/**
* <p>An {@link IMode} {@link Stage} in a {@link Cascade} Cipher chain.</p>
*
* <p>Such a stage wraps an implementation of a Block Cipher Mode of Operation
* ({@link IMode}) to allow inclusion of such an instance in a cascade of block
* ciphers.</p>
*
* @version $Revision: 1.3 $
*/
class ModeStage extends Stage {
// Constants and variables
// -------------------------------------------------------------------------
private IMode delegate;
private transient Set cachedBlockSizes;
// Constructor(s)
// -------------------------------------------------------------------------
ModeStage(IMode mode, Direction forwardDirection) {
super(forwardDirection);
delegate = mode;
cachedBlockSizes = null;
}
// Class methods
// -------------------------------------------------------------------------
// Instance methods
// -------------------------------------------------------------------------
public Set blockSizes() {
if (cachedBlockSizes == null) {
HashSet result = new HashSet();
for (Iterator it = delegate.blockSizes(); it.hasNext(); ) {
result.add(it.next());
}
cachedBlockSizes = Collections.unmodifiableSet(result);
}
return cachedBlockSizes;
}
void initDelegate(Map attributes) throws InvalidKeyException {
Direction flow = (Direction) attributes.get(DIRECTION);
attributes.put(IMode.STATE, new Integer(
flow.equals(forward) ? IMode.ENCRYPTION : IMode.DECRYPTION));
delegate.init(attributes);
}
public int currentBlockSize() throws IllegalStateException {
return delegate.currentBlockSize();
}
void resetDelegate() {
delegate.reset();
}
void updateDelegate(byte[] in, int inOffset, byte[] out, int outOffset) {
delegate.update(in, inOffset, out, outOffset);
}
public boolean selfTest() {
return delegate.selfTest();
}
}