package gnu.crypto.assembly;
// ----------------------------------------------------------------------------
// $Id: CascadeTransformer.java,v 1.2 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 java.security.InvalidKeyException;
import java.util.Map;
/**
* An Adapter to use any {@link Cascade} as a {@link Transformer} in an
* {@link Assembly}.
*
* @version $Revision: 1.2 $
*/
class CascadeTransformer extends Transformer {
// Constants and variables
// -------------------------------------------------------------------------
private Cascade delegate;
private int blockSize;
// Constructor(s)
// -------------------------------------------------------------------------
CascadeTransformer(Cascade delegate) {
super();
this.delegate = delegate;
}
// Class methods
// -------------------------------------------------------------------------
// Instant methods
// -------------------------------------------------------------------------
void initDelegate(Map attributes) throws TransformerException {
attributes.put(Cascade.DIRECTION, wired);
try {
delegate.init(attributes);
} catch (InvalidKeyException x) {
throw new TransformerException("initDelegate()", x);
}
blockSize = delegate.currentBlockSize();
}
int delegateBlockSize() {
return blockSize;
}
void resetDelegate() {
delegate.reset();
blockSize = 0;
}
byte[] updateDelegate(byte[] in, int offset, int length) throws TransformerException {
byte[] result = updateInternal(in, offset, length);
return result;
}
byte[] lastUpdateDelegate() throws TransformerException {
if (inBuffer.size() != 0) {
throw new TransformerException("lastUpdateDelegate()",
new IllegalStateException("Cascade transformer, after last "
+"update, must be empty but isn't"));
}
return new byte[0];
}
private byte[] updateInternal(byte[] in, int offset, int length) {
byte[] result;
for (int i = 0; i < length; i++) {
inBuffer.write(in[offset++] & 0xFF);
if (inBuffer.size() >= blockSize) {
result = inBuffer.toByteArray();
inBuffer.reset();
delegate.update(result, 0, result, 0);
outBuffer.write(result, 0, blockSize);
}
}
result = outBuffer.toByteArray();
outBuffer.reset();
return result;
}
}