util.java

SSD9 练习9

/*
 * MM JDBC Drivers for MySQL
 *
 * $Id: Util.java,v 1.1.1.1 1998/08/24 16:37:38 mmatthew Exp $
 *
 * Copyright (C) 1998 Mark Matthews <[e-mail]>
 * 
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Library General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Library General Public License for more details.
 * 
 * You should have received a copy of the GNU Library General Public
 * License along with this library; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA  02111-1307, USA.
 *
 * See the COPYING file located in the top-level-directory of
 * the archive of this library for complete text of license.
 */

package org.gjt.mm.mysql;

import java.io.ObjectInputStream;

public class Util {
    // Right from Monty's code

    static String newCrypt(String Passwd, String Seed) {
        byte b;
        double d;

        if (Passwd == null || Passwd.length() == 0)
            return Passwd;

        long[] pw = newHash(Seed);
        long[] msg = newHash(Passwd);

        long max = 0x3fffffffL;
        long seed1 = (pw[0] ^ msg[0]) % max;
        long seed2 = (pw[1] ^ msg[1]) % max;

        char[] chars = new char[Passwd.length()];

        for (int i = 0; i < Passwd.length(); i++) {
            seed1 = (seed1 * 3 + seed2) % max;
            seed2 = (seed1 + seed2 + 33) % max;
            d = (double)seed1 / (double)max;
            b = (byte)java.lang.Math.floor((d * 31) + 64);
            chars[i] = (char)b;
        }

        seed1 = (seed1 * 3 + seed2) % max;
        seed2 = (seed1 + seed2 + 33) % max;
        d = (double)seed1 / (double)max;
        b = (byte)java.lang.Math.floor(d * 31);

        for (int i = 0; i < Passwd.length(); i++)
            chars[i] ^= (char)b;

        return new String(chars);
    }

    static String oldCrypt(String Passwd, String Seed) {
        long hp, hm, s1, s2;
        long max = 0x01FFFFFF;
        double d;
        byte b;

        if (Passwd == null || Passwd.length() == 0 )
            return Passwd;

        hp = oldHash(Seed);
        hm = oldHash(Passwd);
        long nr = hp ^ hm;
        nr %= max;
        s1 = nr;
        s2 = nr/2;

        char[] chars = new char[Passwd.length()];

        for (int i = 0; i< Passwd.length(); i++) {
            s1 = (s1 * 3 + s2) % max;
            s2 = (s1 + s2 + 33) % max;
            d = (double)s1 / max;
            b = (byte)java.lang.Math.floor((d * 31) + 64);
            chars[i] = (char)b;
        }
        return new String(chars);
    }

    static long[] newHash(String P) {
        long nr=1345345333L;
        long add=7;
        long nr2=0x12345671L;
        long tmp;
        for (int i = 0; i < P.length(); ++i) {
            if (P.charAt(i) == ' ' || P.charAt(i) == '\t')
                continue;       // skip spaces
            tmp = (long)(0xff & P.charAt(i));
            nr ^= (((nr & 63) + add) * tmp) + (nr << 8);
            nr2 += (nr2 << 8) ^ nr;
            add += tmp;
        }
        long[] result = new long[2];
        result[0] = nr & 0x7fffffffL;
        result[1] = nr2 & 0x7fffffffL;
        return result;
    }

    static long oldHash(String P) {
        long  nr=1345345333;
        long  nr2=7;
        long tmp;

        for (int i = 0; i < P.length(); i++) {
            if ((P.charAt(i) == ' ') || (P.charAt(i) == '\t'))
                continue;
            tmp = (long)P.charAt(i);
            nr ^= (((nr & 63) + nr2) * tmp) + (nr << 8);
            nr2 += tmp;
        }
        return nr & (((long) 1L << 31) -1L);
    }

    /**
     * Given a ResultSet and an index into the columns of that ResultSet,
     * read binary data from the column which represents a serialized object,
     * and re-create the object.
     *
     * @param RS the ResultSet to use.
     * @param index an index into the ResultSet.
     * @return the object if it can be de-serialized
     * @throws Exception if an error occurs
     */

public static Object readObject(java.sql.ResultSet RS, int index)
        throws Exception
        {
            ObjectInputStream ObjIn = new
                                      ObjectInputStream(RS.getBinaryStream(index));
            Object O = ObjIn.readObject();
            ObjIn.close();

            return O;
        }
}