crypto/src/java/org/apache/fulcrum/crypto/impl/UnixCrypt.java

package org.apache.fulcrum.crypto.impl;

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

import java.util.Random;

/**
 * Unix crypt (3) algorithm implementation. The java
 * implementation was taken from the JetSpeed Portal project
 * (see org.apache.jetspeed.services.security.ldap.UnixCrypt).
 *
 * @author Siegfried Goeschl
 */
public class UnixCrypt
{
    private static final char saltChars[] = "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789./".toCharArray();
    private static final int ITERATIONS = 16;
    private static final int con_salt[] = {
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
        0, 0, 0, 0, 0, 0, 0, 1, 2, 3,
        4, 5, 6, 7, 8, 9, 10, 11, 5, 6,
        7, 8, 9, 10, 11, 12, 13, 14, 15, 16,
        17, 18, 19, 20, 21, 22, 23, 24, 25, 26,
        27, 28, 29, 30, 31, 32, 33, 34, 35, 36,
        37, 32, 33, 34, 35, 36, 37, 38, 39, 40,
        41, 42, 43, 44, 45, 46, 47, 48, 49, 50,
        51, 52, 53, 54, 55, 56, 57, 58, 59, 60,
        61, 62, 63, 0, 0, 0, 0, 0
    };
    private static final boolean shifts2[] = {
        false, false, true, true, true, true, true, true, false, true,
        true, true, true, true, true, false
    };
    private static final int skb[][] = {
        {
            0, 16, 0x20000000, 0x20000010, 0x10000, 0x10010, 0x20010000, 0x20010010, 2048, 2064,
            0x20000800, 0x20000810, 0x10800, 0x10810, 0x20010800, 0x20010810, 32, 48, 0x20000020, 0x20000030,
            0x10020, 0x10030, 0x20010020, 0x20010030, 2080, 2096, 0x20000820, 0x20000830, 0x10820, 0x10830,
            0x20010820, 0x20010830, 0x80000, 0x80010, 0x20080000, 0x20080010, 0x90000, 0x90010, 0x20090000, 0x20090010,
            0x80800, 0x80810, 0x20080800, 0x20080810, 0x90800, 0x90810, 0x20090800, 0x20090810, 0x80020, 0x80030,
            0x20080020, 0x20080030, 0x90020, 0x90030, 0x20090020, 0x20090030, 0x80820, 0x80830, 0x20080820, 0x20080830,
            0x90820, 0x90830, 0x20090820, 0x20090830
        }, {
            0, 0x2000000, 8192, 0x2002000, 0x200000, 0x2200000, 0x202000, 0x2202000, 4, 0x2000004,
            8196, 0x2002004, 0x200004, 0x2200004, 0x202004, 0x2202004, 1024, 0x2000400, 9216, 0x2002400,
            0x200400, 0x2200400, 0x202400, 0x2202400, 1028, 0x2000404, 9220, 0x2002404, 0x200404, 0x2200404,
            0x202404, 0x2202404, 0x10000000, 0x12000000, 0x10002000, 0x12002000, 0x10200000, 0x12200000, 0x10202000, 0x12202000,
            0x10000004, 0x12000004, 0x10002004, 0x12002004, 0x10200004, 0x12200004, 0x10202004, 0x12202004, 0x10000400, 0x12000400,
            0x10002400, 0x12002400, 0x10200400, 0x12200400, 0x10202400, 0x12202400, 0x10000404, 0x12000404, 0x10002404, 0x12002404,
            0x10200404, 0x12200404, 0x10202404, 0x12202404
        }, {
            0, 1, 0x40000, 0x40001, 0x1000000, 0x1000001, 0x1040000, 0x1040001, 2, 3,
            0x40002, 0x40003, 0x1000002, 0x1000003, 0x1040002, 0x1040003, 512, 513, 0x40200, 0x40201,
            0x1000200, 0x1000201, 0x1040200, 0x1040201, 514, 515, 0x40202, 0x40203, 0x1000202, 0x1000203,
            0x1040202, 0x1040203, 0x8000000, 0x8000001, 0x8040000, 0x8040001, 0x9000000, 0x9000001, 0x9040000, 0x9040001,
            0x8000002, 0x8000003, 0x8040002, 0x8040003, 0x9000002, 0x9000003, 0x9040002, 0x9040003, 0x8000200, 0x8000201,
            0x8040200, 0x8040201, 0x9000200, 0x9000201, 0x9040200, 0x9040201, 0x8000202, 0x8000203, 0x8040202, 0x8040203,
            0x9000202, 0x9000203, 0x9040202, 0x9040203
        }, {
            0, 0x100000, 256, 0x100100, 8, 0x100008, 264, 0x100108, 4096, 0x101000,
            4352, 0x101100, 4104, 0x101008, 4360, 0x101108, 0x4000000, 0x4100000, 0x4000100, 0x4100100,
            0x4000008, 0x4100008, 0x4000108, 0x4100108, 0x4001000, 0x4101000, 0x4001100, 0x4101100, 0x4001008, 0x4101008,
            0x4001108, 0x4101108, 0x20000, 0x120000, 0x20100, 0x120100, 0x20008, 0x120008, 0x20108, 0x120108,
            0x21000, 0x121000, 0x21100, 0x121100, 0x21008, 0x121008, 0x21108, 0x121108, 0x4020000, 0x4120000,
            0x4020100, 0x4120100, 0x4020008, 0x4120008, 0x4020108, 0x4120108, 0x4021000, 0x4121000, 0x4021100, 0x4121100,
            0x4021008, 0x4121008, 0x4021108, 0x4121108
        }, {
            0, 0x10000000, 0x10000, 0x10010000, 4, 0x10000004, 0x10004, 0x10010004, 0x20000000, 0x30000000,
            0x20010000, 0x30010000, 0x20000004, 0x30000004, 0x20010004, 0x30010004, 0x100000, 0x10100000, 0x110000, 0x10110000,
            0x100004, 0x10100004, 0x110004, 0x10110004, 0x20100000, 0x30100000, 0x20110000, 0x30110000, 0x20100004, 0x30100004,
            0x20110004, 0x30110004, 4096, 0x10001000, 0x11000, 0x10011000, 4100, 0x10001004, 0x11004, 0x10011004,
            0x20001000, 0x30001000, 0x20011000, 0x30011000, 0x20001004, 0x30001004, 0x20011004, 0x30011004, 0x101000, 0x10101000,
            0x111000, 0x10111000, 0x101004, 0x10101004, 0x111004, 0x10111004, 0x20101000, 0x30101000, 0x20111000, 0x30111000,
            0x20101004, 0x30101004, 0x20111004, 0x30111004
        }, {
            0, 0x8000000, 8, 0x8000008, 1024, 0x8000400, 1032, 0x8000408, 0x20000, 0x8020000,
            0x20008, 0x8020008, 0x20400, 0x8020400, 0x20408, 0x8020408, 1, 0x8000001, 9, 0x8000009,
            1025, 0x8000401, 1033, 0x8000409, 0x20001, 0x8020001, 0x20009, 0x8020009, 0x20401, 0x8020401,
            0x20409, 0x8020409, 0x2000000, 0xa000000, 0x2000008, 0xa000008, 0x2000400, 0xa000400, 0x2000408, 0xa000408,
            0x2020000, 0xa020000, 0x2020008, 0xa020008, 0x2020400, 0xa020400, 0x2020408, 0xa020408, 0x2000001, 0xa000001,
            0x2000009, 0xa000009, 0x2000401, 0xa000401, 0x2000409, 0xa000409, 0x2020001, 0xa020001, 0x2020009, 0xa020009,
            0x2020401, 0xa020401, 0x2020409, 0xa020409
        }, {
            0, 256, 0x80000, 0x80100, 0x1000000, 0x1000100, 0x1080000, 0x1080100, 16, 272,
            0x80010, 0x80110, 0x1000010, 0x1000110, 0x1080010, 0x1080110, 0x200000, 0x200100, 0x280000, 0x280100,
            0x1200000, 0x1200100, 0x1280000, 0x1280100, 0x200010, 0x200110, 0x280010, 0x280110, 0x1200010, 0x1200110,
            0x1280010, 0x1280110, 512, 768, 0x80200, 0x80300, 0x1000200, 0x1000300, 0x1080200, 0x1080300,
            528, 784, 0x80210, 0x80310, 0x1000210, 0x1000310, 0x1080210, 0x1080310, 0x200200, 0x200300,
            0x280200, 0x280300, 0x1200200, 0x1200300, 0x1280200, 0x1280300, 0x200210, 0x200310, 0x280210, 0x280310,
            0x1200210, 0x1200310, 0x1280210, 0x1280310
        }, {
            0, 0x4000000, 0x40000, 0x4040000, 2, 0x4000002, 0x40002, 0x4040002, 8192, 0x4002000,
            0x42000, 0x4042000, 8194, 0x4002002, 0x42002, 0x4042002, 32, 0x4000020, 0x40020, 0x4040020,
            34, 0x4000022, 0x40022, 0x4040022, 8224, 0x4002020, 0x42020, 0x4042020, 8226, 0x4002022,
            0x42022, 0x4042022, 2048, 0x4000800, 0x40800, 0x4040800, 2050, 0x4000802, 0x40802, 0x4040802,
            10240, 0x4002800, 0x42800, 0x4042800, 10242, 0x4002802, 0x42802, 0x4042802, 2080, 0x4000820,
            0x40820, 0x4040820, 2082, 0x4000822, 0x40822, 0x4040822, 10272, 0x4002820, 0x42820, 0x4042820,
            10274, 0x4002822, 0x42822, 0x4042822
        }
    };
    private static final int SPtrans[][] = {
        {
            0x820200, 0x20000, 0x80800000, 0x80820200, 0x800000, 0x80020200, 0x80020000, 0x80800000, 0x80020200, 0x820200,
            0x820000, 0x80000200, 0x80800200, 0x800000, 0, 0x80020000, 0x20000, 0x80000000, 0x800200, 0x20200,
            0x80820200, 0x820000, 0x80000200, 0x800200, 0x80000000, 512, 0x20200, 0x80820000, 512, 0x80800200,
            0x80820000, 0, 0, 0x80820200, 0x800200, 0x80020000, 0x820200, 0x20000, 0x80000200, 0x800200,
            0x80820000, 512, 0x20200, 0x80800000, 0x80020200, 0x80000000, 0x80800000, 0x820000, 0x80820200, 0x20200,
            0x820000, 0x80800200, 0x800000, 0x80000200, 0x80020000, 0, 0x20000, 0x800000, 0x80800200, 0x820200,
            0x80000000, 0x80820000, 512, 0x80020200
        }, {
            0x10042004, 0, 0x42000, 0x10040000, 0x10000004, 8196, 0x10002000, 0x42000, 8192, 0x10040004,
            4, 0x10002000, 0x40004, 0x10042000, 0x10040000, 4, 0x40000, 0x10002004, 0x10040004, 8192,
            0x42004, 0x10000000, 0, 0x40004, 0x10002004, 0x42004, 0x10042000, 0x10000004, 0x10000000, 0x40000,
            8196, 0x10042004, 0x40004, 0x10042000, 0x10002000, 0x42004, 0x10042004, 0x40004, 0x10000004, 0,
            0x10000000, 8196, 0x40000, 0x10040004, 8192, 0x10000000, 0x42004, 0x10002004, 0x10042000, 8192,
            0, 0x10000004, 4, 0x10042004, 0x42000, 0x10040000, 0x10040004, 0x40000, 8196, 0x10002000,
            0x10002004, 4, 0x10040000, 0x42000
        }, {
            0x41000000, 0x1010040, 64, 0x41000040, 0x40010000, 0x1000000, 0x41000040, 0x10040, 0x1000040, 0x10000,
            0x1010000, 0x40000000, 0x41010040, 0x40000040, 0x40000000, 0x41010000, 0, 0x40010000, 0x1010040, 64,
            0x40000040, 0x41010040, 0x10000, 0x41000000, 0x41010000, 0x1000040, 0x40010040, 0x1010000, 0x10040, 0,
            0x1000000, 0x40010040, 0x1010040, 64, 0x40000000, 0x10000, 0x40000040, 0x40010000, 0x1010000, 0x41000040,
            0, 0x1010040, 0x10040, 0x41010000, 0x40010000, 0x1000000, 0x41010040, 0x40000000, 0x40010040, 0x41000000,
            0x1000000, 0x41010040, 0x10000, 0x1000040, 0x41000040, 0x10040, 0x1000040, 0, 0x41010000, 0x40000040,
            0x41000000, 0x40010040, 64, 0x1010000
        }, {
            0x100402, 0x4000400, 2, 0x4100402, 0, 0x4100000, 0x4000402, 0x100002, 0x4100400, 0x4000002,
            0x4000000, 1026, 0x4000002, 0x100402, 0x100000, 0x4000000, 0x4100002, 0x100400, 1024, 2,
            0x100400, 0x4000402, 0x4100000, 1024, 1026, 0, 0x100002, 0x4100400, 0x4000400, 0x4100002,
            0x4100402, 0x100000, 0x4100002, 1026, 0x100000, 0x4000002, 0x100400, 0x4000400, 2, 0x4100000,
            0x4000402, 0, 1024, 0x100002, 0, 0x4100002, 0x4100400, 1024, 0x4000000, 0x4100402,
            0x100402, 0x100000, 0x4100402, 2, 0x4000400, 0x100402, 0x100002, 0x100400, 0x4100000, 0x4000402,
            1026, 0x4000000, 0x4000002, 0x4100400
        }, {
            0x2000000, 16384, 256, 0x2004108, 0x2004008, 0x2000100, 16648, 0x2004000, 16384, 8,
            0x2000008, 16640, 0x2000108, 0x2004008, 0x2004100, 0, 16640, 0x2000000, 16392, 264,
            0x2000100, 16648, 0, 0x2000008, 8, 0x2000108, 0x2004108, 16392, 0x2004000, 256,
            264, 0x2004100, 0x2004100, 0x2000108, 16392, 0x2004000, 16384, 8, 0x2000008, 0x2000100,
            0x2000000, 16640, 0x2004108, 0, 16648, 0x2000000, 256, 16392, 0x2000108, 256,
            0, 0x2004108, 0x2004008, 0x2004100, 264, 16384, 16640, 0x2004008, 0x2000100, 264,
            8, 16648, 0x2004000, 0x2000008
        }, {
            0x20000010, 0x80010, 0, 0x20080800, 0x80010, 2048, 0x20000810, 0x80000, 2064, 0x20080810,
            0x80800, 0x20000000, 0x20000800, 0x20000010, 0x20080000, 0x80810, 0x80000, 0x20000810, 0x20080010, 0,
            2048, 16, 0x20080800, 0x20080010, 0x20080810, 0x20080000, 0x20000000, 2064, 16, 0x80800,
            0x80810, 0x20000800, 2064, 0x20000000, 0x20000800, 0x80810, 0x20080800, 0x80010, 0, 0x20000800,
            0x20000000, 2048, 0x20080010, 0x80000, 0x80010, 0x20080810, 0x80800, 16, 0x20080810, 0x80800,
            0x80000, 0x20000810, 0x20000010, 0x20080000, 0x80810, 0, 2048, 0x20000010, 0x20000810, 0x20080800,
            0x20080000, 2064, 16, 0x20080010
        }, {
            4096, 128, 0x400080, 0x400001, 0x401081, 4097, 4224, 0, 0x400000, 0x400081,
            129, 0x401000, 1, 0x401080, 0x401000, 129, 0x400081, 4096, 4097, 0x401081,
            0, 0x400080, 0x400001, 4224, 0x401001, 4225, 0x401080, 1, 4225, 0x401001,
            128, 0x400000, 4225, 0x401000, 0x401001, 129, 4096, 128, 0x400000, 0x401001,
            0x400081, 4225, 4224, 0, 128, 0x400001, 1, 0x400080, 0, 0x400081,
            0x400080, 4224, 129, 4096, 0x401081, 0x400000, 0x401080, 1, 4097, 0x401081,
            0x400001, 0x401080, 0x401000, 4097
        }, {
            0x8200020, 0x8208000, 32800, 0, 0x8008000, 0x200020, 0x8200000, 0x8208020, 32, 0x8000000,
            0x208000, 32800, 0x208020, 0x8008020, 0x8000020, 0x8200000, 32768, 0x208020, 0x200020, 0x8008000,
            0x8208020, 0x8000020, 0, 0x208000, 0x8000000, 0x200000, 0x8008020, 0x8200020, 0x200000, 32768,
            0x8208000, 32, 0x200000, 32768, 0x8000020, 0x8208020, 32800, 0x8000000, 0, 0x208000,
            0x8200020, 0x8008020, 0x8008000, 0x200020, 0x8208000, 32, 0x200020, 0x8008000, 0x8208020, 0x200000,
            0x8200000, 0x8000020, 0x208000, 32800, 0x8008020, 0x8200000, 32, 0x8208000, 0x208020, 0,
            0x8000000, 0x8200020, 32768, 0x208020
        }
    };
    private static final int cov_2char[] = {
        46, 47, 48, 49, 50, 51, 52, 53, 54, 55,
        56, 57, 65, 66, 67, 68, 69, 70, 71, 72,
        73, 74, 75, 76, 77, 78, 79, 80, 81, 82,
        83, 84, 85, 86, 87, 88, 89, 90, 97, 98,
        99, 100, 101, 102, 103, 104, 105, 106, 107, 108,
        109, 110, 111, 112, 113, 114, 115, 116, 117, 118,
        119, 120, 121, 122
    };

    private UnixCrypt() {}
    
    private static final int D_ENCRYPT(int L, int R, int S, int E0, int E1, int s[])
    {
        int v = R ^ R >>> 16;
        int u = v & E0;
        v &= E1;
        u = u ^ u << 16 ^ R ^ s[S];
        int t = v ^ v << 16 ^ R ^ s[S + 1];
        t = t >>> 4 | t << 28;
        L ^= SPtrans[1][t & 0x3f] | SPtrans[3][t >>> 8 & 0x3f] | SPtrans[5][t >>> 16 & 0x3f] | SPtrans[7][t >>> 24 & 0x3f] | SPtrans[0][u & 0x3f] | SPtrans[2][u >>> 8 & 0x3f] | SPtrans[4][u >>> 16 & 0x3f] | SPtrans[6][u >>> 24 & 0x3f];
        return L;
    }

    private static final int HPERM_OP(int a, int n, int m)
    {
        int t = (a << 16 - n ^ a) & m;
        a = a ^ t ^ t >>> 16 - n;
        return a;
    }

    private static final void PERM_OP(int a, int b, int n, int m, int results[])
    {
        int t = (a >>> n ^ b) & m;
        a ^= t << n;
        b ^= t;
        results[0] = a;
        results[1] = b;
    }

    private static final int[] body(int schedule[], int Eswap0, int Eswap1)
    {
        int left = 0;
        int right = 0;
        int t = 0;
        for(int j = 0; j < 25; j++)
        {
            for(int i = 0; i < 32; i += 4)
            {
                left = D_ENCRYPT(left, right, i, Eswap0, Eswap1, schedule);
                right = D_ENCRYPT(right, left, i + 2, Eswap0, Eswap1, schedule);
            }

            t = left;
            left = right;
            right = t;
        }

        t = right;
        right = left >>> 1 | left << 31;
        left = t >>> 1 | t << 31;
        left &= 0xffffffff;
        right &= 0xffffffff;
        int results[] = new int[2];
        PERM_OP(right, left, 1, 0x55555555, results);
        right = results[0];
        left = results[1];
        PERM_OP(left, right, 8, 0xff00ff, results);
        left = results[0];
        right = results[1];
        PERM_OP(right, left, 2, 0x33333333, results);
        right = results[0];
        left = results[1];
        PERM_OP(left, right, 16, 65535, results);
        left = results[0];
        right = results[1];
        PERM_OP(right, left, 4, 0xf0f0f0f, results);
        right = results[0];
        left = results[1];
        int out[] = new int[2];
        out[0] = left;
        out[1] = right;
        return out;
    }

    private static final int byteToUnsigned(byte b)
    {
        int value = b;
        return value < 0 ? value + 256 : value;
    }

    public static final String crypt(String original)
    {
        Random randomGenerator = new Random();
        int numSaltChars = saltChars.length;
        String salt = "" + saltChars[Math.abs(randomGenerator.nextInt()) % numSaltChars] + saltChars[Math.abs(randomGenerator.nextInt()) % numSaltChars];
        return crypt(salt, original);
    }

    public static final String crypt(String salt, String original)
    {
        for(; salt.length() < 2; salt = salt + "A");
        StringBuffer buffer = new StringBuffer("             ");
        char charZero = salt.charAt(0);
        char charOne = salt.charAt(1);
        buffer.setCharAt(0, charZero);
        buffer.setCharAt(1, charOne);
        int Eswap0 = con_salt[charZero];
        int Eswap1 = con_salt[charOne] << 4;
        byte key[] = new byte[8];
        for(int i = 0; i < key.length; i++)
            key[i] = 0;

        for(int i = 0; i < key.length && i < original.length(); i++)
        {
            int iChar = original.charAt(i);
            key[i] = (byte)(iChar << 1);
        }

        int schedule[] = des_set_key(key);
        int out[] = body(schedule, Eswap0, Eswap1);
        byte b[] = new byte[9];
        intToFourBytes(out[0], b, 0);
        intToFourBytes(out[1], b, 4);
        b[8] = 0;
        int i = 2;
        int y = 0;
        int u = 128;
        for(; i < 13; i++)
        {
            int j = 0;
            int c = 0;
            for(; j < 6; j++)
            {
                c <<= 1;
                if((b[y] & u) != 0)
                    c |= 0x1;
                u >>>= 1;
                if(u == 0)
                {
                    y++;
                    u = 128;
                }
                buffer.setCharAt(i, (char) cov_2char[c]);
            }

        }

        return buffer.toString();
    }

    private static int[] des_set_key(byte key[])
    {
        int schedule[] = new int[32];
        int c = fourBytesToInt(key, 0);
        int d = fourBytesToInt(key, 4);
        int results[] = new int[2];
        PERM_OP(d, c, 4, 0xf0f0f0f, results);
        d = results[0];
        c = results[1];
        c = HPERM_OP(c, -2, 0xcccc0000);
        d = HPERM_OP(d, -2, 0xcccc0000);
        PERM_OP(d, c, 1, 0x55555555, results);
        d = results[0];
        c = results[1];
        PERM_OP(c, d, 8, 0xff00ff, results);
        c = results[0];
        d = results[1];
        PERM_OP(d, c, 1, 0x55555555, results);
        d = results[0];
        c = results[1];
        d = (d & 0xff) << 16 | d & 0xff00 | (d & 0xff0000) >>> 16 | (c & 0xf0000000) >>> 4;
        c &= 0xfffffff;
        int j = 0;
        for(int i = 0; i < 16; i++)
        {
            if(shifts2[i])
            {
                c = c >>> 2 | c << 26;
                d = d >>> 2 | d << 26;
            } else
            {
                c = c >>> 1 | c << 27;
                d = d >>> 1 | d << 27;
            }
            c &= 0xfffffff;
            d &= 0xfffffff;
            int s = skb[0][c & 0x3f] | skb[1][c >>> 6 & 0x3 | c >>> 7 & 0x3c] | skb[2][c >>> 13 & 0xf | c >>> 14 & 0x30] | skb[3][c >>> 20 & 0x1 | c >>> 21 & 0x6 | c >>> 22 & 0x38];
            int t = skb[4][d & 0x3f] | skb[5][d >>> 7 & 0x3 | d >>> 8 & 0x3c] | skb[6][d >>> 15 & 0x3f] | skb[7][d >>> 21 & 0xf | d >>> 22 & 0x30];
            schedule[j++] = (t << 16 | s & 0xffff) & 0xffffffff;
            s = s >>> 16 | t & 0xffff0000;
            s = s << 4 | s >>> 28;
            schedule[j++] = s & 0xffffffff;
        }

        return schedule;
    }

    private static int fourBytesToInt(byte b[], int offset)
    {
        int value = byteToUnsigned(b[offset++]);
        value |= byteToUnsigned(b[offset++]) << 8;
        value |= byteToUnsigned(b[offset++]) << 16;
        value |= byteToUnsigned(b[offset++]) << 24;
        return value;
    }

    private static final void intToFourBytes(int iValue, byte b[], int offset)
    {
        b[offset++] = (byte)(iValue & 0xff);
        b[offset++] = (byte)(iValue >>> 8 & 0xff);
        b[offset++] = (byte)(iValue >>> 16 & 0xff);
        b[offset++] = (byte)(iValue >>> 24 & 0xff);
    }

    public static final boolean matches(String encryptedPassword, String enteredPassword)
    {
        String salt = encryptedPassword.substring(0, 3);
        String newCrypt = crypt(salt, enteredPassword);
        return newCrypt.equals(encryptedPassword);
    }

}