MacSpi.java revision 0
0N/A/*
0N/A * Copyright 1998-2007 Sun Microsystems, Inc. All Rights Reserved.
0N/A * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
0N/A *
0N/A * This code is free software; you can redistribute it and/or modify it
0N/A * under the terms of the GNU General Public License version 2 only, as
0N/A * published by the Free Software Foundation. Sun designates this
0N/A * particular file as subject to the "Classpath" exception as provided
0N/A * by Sun in the LICENSE file that accompanied this code.
0N/A *
0N/A * This code is distributed in the hope that it will be useful, but WITHOUT
0N/A * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
0N/A * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
0N/A * version 2 for more details (a copy is included in the LICENSE file that
0N/A * accompanied this code).
0N/A *
0N/A * You should have received a copy of the GNU General Public License version
0N/A * 2 along with this work; if not, write to the Free Software Foundation,
0N/A * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
0N/A *
0N/A * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
0N/A * CA 95054 USA or visit www.sun.com if you need additional information or
0N/A * have any questions.
0N/A */
0N/A
0N/Apackage javax.crypto;
0N/A
0N/Aimport java.security.*;
0N/Aimport java.security.spec.*;
0N/A
0N/Aimport java.nio.ByteBuffer;
0N/A
0N/A/**
0N/A * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>)
0N/A * for the <code>Mac</code> class.
0N/A * All the abstract methods in this class must be implemented by each
0N/A * cryptographic service provider who wishes to supply the implementation
0N/A * of a particular MAC algorithm.
0N/A *
0N/A * <p> Implementations are free to implement the Cloneable interface.
0N/A *
0N/A * @author Jan Luehe
0N/A *
0N/A * @since 1.4
0N/A */
0N/A
0N/Apublic abstract class MacSpi {
0N/A
0N/A /**
0N/A * Returns the length of the MAC in bytes.
0N/A *
0N/A * @return the MAC length in bytes.
0N/A */
0N/A protected abstract int engineGetMacLength();
0N/A
0N/A /**
0N/A * Initializes the MAC with the given (secret) key and algorithm
0N/A * parameters.
0N/A *
0N/A * @param key the (secret) key.
0N/A * @param params the algorithm parameters.
0N/A *
0N/A * @exception InvalidKeyException if the given key is inappropriate for
0N/A * initializing this MAC.
0N/A * @exception InvalidAlgorithmParameterException if the given algorithm
0N/A * parameters are inappropriate for this MAC.
0N/A */
0N/A protected abstract void engineInit(Key key,
0N/A AlgorithmParameterSpec params)
0N/A throws InvalidKeyException, InvalidAlgorithmParameterException ;
0N/A
0N/A /**
0N/A * Processes the given byte.
0N/A *
0N/A * @param input the input byte to be processed.
0N/A */
0N/A protected abstract void engineUpdate(byte input);
0N/A
0N/A /**
0N/A * Processes the first <code>len</code> bytes in <code>input</code>,
0N/A * starting at <code>offset</code> inclusive.
0N/A *
0N/A * @param input the input buffer.
0N/A * @param offset the offset in <code>input</code> where the input starts.
0N/A * @param len the number of bytes to process.
0N/A */
0N/A protected abstract void engineUpdate(byte[] input, int offset, int len);
0N/A
0N/A /**
0N/A * Processes <code>input.remaining()</code> bytes in the ByteBuffer
0N/A * <code>input</code>, starting at <code>input.position()</code>.
0N/A * Upon return, the buffer's position will be equal to its limit;
0N/A * its limit will not have changed.
0N/A *
0N/A * <p>Subclasses should consider overriding this method if they can
0N/A * process ByteBuffers more efficiently than byte arrays.
0N/A *
0N/A * @param input the ByteBuffer
0N/A * @since 1.5
0N/A */
0N/A protected void engineUpdate(ByteBuffer input) {
0N/A if (input.hasRemaining() == false) {
0N/A return;
0N/A }
0N/A if (input.hasArray()) {
0N/A byte[] b = input.array();
0N/A int ofs = input.arrayOffset();
0N/A int pos = input.position();
0N/A int lim = input.limit();
0N/A engineUpdate(b, ofs + pos, lim - pos);
0N/A input.position(lim);
0N/A } else {
0N/A int len = input.remaining();
0N/A byte[] b = new byte[CipherSpi.getTempArraySize(len)];
0N/A while (len > 0) {
0N/A int chunk = Math.min(len, b.length);
0N/A input.get(b, 0, chunk);
0N/A engineUpdate(b, 0, chunk);
0N/A len -= chunk;
0N/A }
0N/A }
0N/A }
0N/A
0N/A /**
0N/A * Completes the MAC computation and resets the MAC for further use,
0N/A * maintaining the secret key that the MAC was initialized with.
0N/A *
0N/A * @return the MAC result.
0N/A */
0N/A protected abstract byte[] engineDoFinal();
0N/A
0N/A /**
0N/A * Resets the MAC for further use, maintaining the secret key that the
0N/A * MAC was initialized with.
0N/A */
0N/A protected abstract void engineReset();
0N/A
0N/A /**
0N/A * Returns a clone if the implementation is cloneable.
0N/A *
0N/A * @return a clone if the implementation is cloneable.
0N/A *
0N/A * @exception CloneNotSupportedException if this is called
0N/A * on an implementation that does not support <code>Cloneable</code>.
0N/A */
0N/A public Object clone() throws CloneNotSupportedException {
0N/A if (this instanceof Cloneable) {
0N/A return super.clone();
0N/A } else {
0N/A throw new CloneNotSupportedException();
0N/A }
0N/A }
0N/A}