/* * Copyright (c) 1998, 2009, 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 com.sun.crypto.provider; import java.nio.ByteBuffer; import javax.crypto.MacSpi;import javax.crypto.SecretKey;import java.security.*;import java.security.spec.*; /** * This is an implementation of the HMAC-SHA1 algorithm. * * @author Jan Luehe */public final class HmacSHA1 extends MacSpi implements Cloneable {     private HmacCore hmac = null;    private static final int SHA1_BLOCK_LENGTH = 64;     /**     * Standard constructor, creates a new HmacSHA1 instance.     */    public HmacSHA1() throws NoSuchAlgorithmException {        this.hmac = new HmacCore(MessageDigest.getInstance("SHA1"),                                 SHA1_BLOCK_LENGTH);    }     /**     * Returns the length of the HMAC in bytes.     *     * @return the HMAC length in bytes.     */    protected int engineGetMacLength() {        return hmac.getDigestLength();    }     /**     * Initializes the HMAC 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 void engineInit(Key key, AlgorithmParameterSpec params)        throws InvalidKeyException, InvalidAlgorithmParameterException {        hmac.init(key, params);    }     /**     * Processes the given byte.     *     * @param input the input byte to be processed.     */    protected void engineUpdate(byte input) {        hmac.update(input);    }     /**     * Processes the first <code>len</code> bytes in <code>input</code>,     * starting at <code>offset</code>.     *     * @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 void engineUpdate(byte input[], int offset, int len) {        hmac.update(input, offset, len);    }     protected void engineUpdate(ByteBuffer input) {        hmac.update(input);    }     /**     * Completes the HMAC computation and resets the HMAC for further use,     * maintaining the secret key that the HMAC was initialized with.     *     * @return the HMAC result.     */    protected byte[] engineDoFinal() {        return hmac.doFinal();    }     /**     * Resets the HMAC for further use, maintaining the secret key that the     * HMAC was initialized with.     */    protected void engineReset() {        hmac.reset();    }     /*     * Clones this object.     */    public Object clone() {        HmacSHA1 that = null;        try {            that = (HmacSHA1)super.clone();            that.hmac = (HmacCore)this.hmac.clone();        } catch (CloneNotSupportedException e) {        }        return that;    }}