ripemd160.java

jpeg2000编解码

// $Id: RIPEMD160.java,v 1.1.1.1 2002/08/27 12:32:12 grosbois Exp $
//
// $Log: RIPEMD160.java,v $
// Revision 1.1.1.1  2002/08/27 12:32:12  grosbois
// Add cryptix 3.2
//
// Revision 1.4  1997/12/07 07:25:29  hopwood
// + Committed changes below.
//
// Revision 1.3.1  1997/12/07  hopwood
// + Removed '-' from RIPEMD-160 in comments and debug output, since RIPEMD160 is
//   the standard name.
//
// Revision 1.3  1997/12/05 19:09:02  raif
// + removed '-' from string in Debug.getLevel() invocation.
// + cosmetics.
//
// Revision 1.2  1997/11/20 19:36:30  hopwood
// + cryptix.util.* name changes.
//
// Revision 1.1.1.1  1997/11/03 22:36:56  hopwood
// + Imported to CVS (tagged as 'start').
//
// Revision 0.1.0.3  1997/08/14  David Hopwood
// + Added CONTEXT_LENGTH constant.
// + Implemented engineGetDigestLength method.
// + Required native code version is 2.3.
//
// Revision 0.1.0.2  1997/07/21  David Hopwood
// + Changed name of first parameter to native_hash from ctx to context,
//   to be consistent with native code.
// + Check validity of arguments before calling native_hash.
//
// Revision 0.1.0.1  1997/07/15  David Hopwood
// + Changed 'Object native_lock' to 'boolean native_ok'.
// + Removed 'synchronized (native_lock) { ... }' around native_hash call.
//   It isn't necessary to synchronize calls to native methods in this case,
//   because unlike the cipher classes, the native code for hash functions
//   is stateless.
//
// Revision 0.1.0.0  1997/07/14  R. Naffah
// + Original version
//
// $Endlog$
/*
 * Copyright (c) 1997 Systemics Ltd
 * on behalf of the Cryptix Development Team.  All rights reserved.
 */

package cryptix.provider.md;

import cryptix.util.core.Debug;

import java.io.PrintWriter;
import java.security.MessageDigest;

/**
 * Implements the RIPEMD160 message digest algorithm in Java as per the
 * reference below.
 * <p>
 * <b>References:</b>
 * <ol>
 *   <li> Hans Dobbertin, Antoon Bosselaers and Bart Preneel,
 *        "RIPEMD160: A Strengthened Version of RIPEMD," 18 April 1996.
 *        A joint publication by the German Information Security Agency
 *        (POB 20 03 63, D-53133 Bonn, Germany)
 *        and the Katholieke Universiteit Leuven, ESAT-COSIC
 *        (K. Mercierlaan 94, B-3001 Heverlee, Belgium).
 * </ol>
 * <p>
 * <b>Copyright</b> &copy; 1997
 * <a href="http://www.systemics.com/">Systemics Ltd</a> on behalf of the
 * <a href="http://www.systemics.com/docs/cryptix/">Cryptix Development Team</a>.
 * <br>All rights reserved.
 * <p>
 * <b>$Revision: 1.1.1.1 $</b>
 * @author  Raif S. Naffah
 * @author  David Hopwood
 * @since   Cryptix 2.2.2
 */
public class RIPEMD160
extends MessageDigest
implements Cloneable
{
// Debugging methods and vars.
//...........................................................................

    private static final boolean DEBUG = Debug.GLOBAL_DEBUG;
    private static final boolean DEBUG_SLOW = Debug.GLOBAL_DEBUG_SLOW;
    private static int debuglevel = DEBUG ? Debug.getLevel("RIPEMD160") : 0;
    private static final PrintWriter err = DEBUG ? Debug.getOutput() : null;
    private static void debug(String s) { err.println("RIPEMD160: " + s); }


// Native library linking methods and vars.
//...........................................................................

    private static NativeLink linkStatus = new NativeLink("RIPEMD", 2, 3);
    public static cryptix.util.core.LinkStatus getLinkStatus() { return linkStatus; }

    /**
     * This flag is false if the native code is not being used (e.g. the
     * library did not load successfully, or the user disabled its use in
     * the properties file).
     */
    private boolean native_ok; // defaults to false

    private void link() {
        synchronized(linkStatus) {
            try {
                if (linkStatus.attemptLoad())
                    linkStatus.checkVersion(getLibMajorVersion(), getLibMinorVersion());
                if (linkStatus.useNative())
                    native_ok = true;
            } catch (UnsatisfiedLinkError e) {
                linkStatus.fail(e);
if (DEBUG && debuglevel > 2) debug(e.getMessage());
            }
if (DEBUG && debuglevel > 2) debug("Using native library? " + native_ok);
        }
    }


// Native implementation of RIPEMD-128/160 hash
//...........................................................................

    /** The functions that get the library version. */
    private native static int getLibMajorVersion();
    private native static int getLibMinorVersion();

    /**
     * Transforms context based on 512 bits from input block starting from
     * the offset'th byte.
     *
     * @param context   the current context of this instance.
     * @param block     input array containing data to hash.
     * @param offset    index of where we should start reading from input.
     * @return an error string if one occurs, or null otherwise.
     */
    private native static String
    native_hash (int[] context, byte[] block, int offset);


// RIPEMD160 specific object variables
//...........................................................................

    private static final int BLOCK_LENGTH = 64;
    private static final int CONTEXT_LENGTH = 5;
    
    /** 160-bit h0, h1, h2, h3, h4 (interim result) */
    private int[] context = new int[CONTEXT_LENGTH];

    /** number of bytes processed so far. */
    private long count;
    
    /** 512 bits input buffer = 16 x 32-bit words = 8 x 64 bytes */
    private byte[] buffer = new byte[BLOCK_LENGTH];
    
    /** 512 bits work buffer = 16 x 32-bit words */
    private int[] X = new int[16];

    /**
     * Constants for the transform method. They're defined as static because
     * they're common to all RIPEMD160 instantiated objects; and final since
     * they're non-modifiable.
     */
    private static final int[]
        // selection of message word
        R  = {  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, 15,
                7,  4, 13,  1, 10,  6, 15,  3, 12,  0,  9,  5,  2, 14, 11,  8,
                3, 10, 14,  4,  9, 15,  8,  1,  2,  7,  0,  6, 13, 11,  5, 12,
                1,  9, 11, 10,  0,  8, 12,  4, 13,  3,  7, 15, 14,  5,  6,  2,
                4,  0,  5,  9,  7, 12,  2, 10, 14,  1,  3,  8, 11,  6, 15, 13},
        Rp = {  5, 14,  7,  0,  9,  2, 11,  4, 13,  6, 15,  8,  1, 10,  3, 12,
                6, 11,  3,  7,  0, 13,  5, 10, 14, 15,  8, 12,  4,  9,  1,  2,
               15,  5,  1,  3,  7, 14,  6,  9, 11,  8, 12,  2, 10,  0,  4, 13,
                8,  6,  4,  1,  3, 11, 15,  0,  5, 12,  2, 13,  9,  7, 10, 14,
               12, 15, 10,  4,  1,  5,  8,  7,  6,  2, 13, 14,  0,  3,  9, 11},
    
        // amount for rotate left (rol)    
        S  = { 11, 14, 15, 12,  5,  8,  7,  9, 11, 13, 14, 15,  6,  7,  9,  8,
                7,  6,  8, 13, 11,  9,  7, 15,  7, 12, 15,  9, 11,  7, 13, 12,
               11, 13,  6,  7, 14,  9, 13, 15, 14,  8, 13,  6,  5, 12,  7,  5,
               11, 12, 14, 15, 14, 15,  9,  8,  9, 14,  5,  6,  8,  6,  5, 12,
                9, 15,  5, 11,  6,  8, 13, 12,  5, 12, 13, 14, 11,  8,  5,  6},
        Sp = {  8,  9,  9, 11, 13, 15, 15,  5,  7,  7,  8, 11, 14, 14, 12,  6,
                9, 13, 15,  7, 12,  8,  9, 11,  7,  7, 12,  7,  6, 15, 13, 11,
                9,  7, 15, 11,  8,  6,  6, 14, 12, 13,  5, 14, 13, 13,  7,  5,
               15,  5,  8, 11, 14, 14,  6, 14,  6,  9, 12,  9, 12,  5, 15,  8,
                8,  5, 12,  9, 12,  5, 14,  6,  8, 13,  6,  5, 15, 13, 11, 11};


// Constructors
//...........................................................................
    
    public RIPEMD160 () {
        super("RIPEMD160");
        engineReset();
        link();
    }

    /** This constructor is here to implement cloneability of this class. */
    private RIPEMD160 (RIPEMD160 md) {
        this();
        context = (int[])md.context.clone();
        buffer = (byte[])md.buffer.clone();
        count = md.count;
    }


// Cloneable method implementation