| /* |
| * Copyright (c) 1998, 2007, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code 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 |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package javax.crypto; |
| |
| import java.security.*; |
| import java.security.spec.*; |
| |
| import java.nio.ByteBuffer; |
| |
| /** |
| * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>) |
| * for the <code>Mac</code> class. |
| * All the abstract methods in this class must be implemented by each |
| * cryptographic service provider who wishes to supply the implementation |
| * of a particular MAC algorithm. |
| * |
| * <p> Implementations are free to implement the Cloneable interface. |
| * |
| * @author Jan Luehe |
| * |
| * @since 1.4 |
| */ |
| |
| public abstract class MacSpi { |
| |
| /** |
| * Returns the length of the MAC in bytes. |
| * |
| * @return the MAC length in bytes. |
| */ |
| protected abstract int engineGetMacLength(); |
| |
| /** |
| * Initializes the MAC with the given (secret) key and algorithm |
| * parameters. |
| * |
| * @param key the (secret) key. |
| * @param params the algorithm parameters. |
| * |
| * @exception InvalidKeyException if the given key is inappropriate for |
| * initializing this MAC. |
| * @exception InvalidAlgorithmParameterException if the given algorithm |
| * parameters are inappropriate for this MAC. |
| */ |
| protected abstract void engineInit(Key key, |
| AlgorithmParameterSpec params) |
| throws InvalidKeyException, InvalidAlgorithmParameterException ; |
| |
| /** |
| * Processes the given byte. |
| * |
| * @param input the input byte to be processed. |
| */ |
| protected abstract void engineUpdate(byte input); |
| |
| /** |
| * Processes the first <code>len</code> bytes in <code>input</code>, |
| * starting at <code>offset</code> inclusive. |
| * |
| * @param input the input buffer. |
| * @param offset the offset in <code>input</code> where the input starts. |
| * @param len the number of bytes to process. |
| */ |
| protected abstract void engineUpdate(byte[] input, int offset, int len); |
| |
| /** |
| * Processes <code>input.remaining()</code> bytes in the ByteBuffer |
| * <code>input</code>, starting at <code>input.position()</code>. |
| * Upon return, the buffer's position will be equal to its limit; |
| * its limit will not have changed. |
| * |
| * <p>Subclasses should consider overriding this method if they can |
| * process ByteBuffers more efficiently than byte arrays. |
| * |
| * @param input the ByteBuffer |
| * @since 1.5 |
| */ |
| protected void engineUpdate(ByteBuffer input) { |
| if (input.hasRemaining() == false) { |
| return; |
| } |
| if (input.hasArray()) { |
| byte[] b = input.array(); |
| int ofs = input.arrayOffset(); |
| int pos = input.position(); |
| int lim = input.limit(); |
| engineUpdate(b, ofs + pos, lim - pos); |
| input.position(lim); |
| } else { |
| int len = input.remaining(); |
| byte[] b = new byte[CipherSpi.getTempArraySize(len)]; |
| while (len > 0) { |
| int chunk = Math.min(len, b.length); |
| input.get(b, 0, chunk); |
| engineUpdate(b, 0, chunk); |
| len -= chunk; |
| } |
| } |
| } |
| |
| /** |
| * Completes the MAC computation and resets the MAC for further use, |
| * maintaining the secret key that the MAC was initialized with. |
| * |
| * @return the MAC result. |
| */ |
| protected abstract byte[] engineDoFinal(); |
| |
| /** |
| * Resets the MAC for further use, maintaining the secret key that the |
| * MAC was initialized with. |
| */ |
| protected abstract void engineReset(); |
| |
| /** |
| * Returns a clone if the implementation is cloneable. |
| * |
| * @return a clone if the implementation is cloneable. |
| * |
| * @exception CloneNotSupportedException if this is called |
| * on an implementation that does not support <code>Cloneable</code>. |
| */ |
| public Object clone() throws CloneNotSupportedException { |
| if (this instanceof Cloneable) { |
| return super.clone(); |
| } else { |
| throw new CloneNotSupportedException(); |
| } |
| } |
| } |