com.suiveg.utils.encryption.algorithms.Crypt.java Source code

Java tutorial

Introduction

Here is the source code for com.suiveg.utils.encryption.algorithms.Crypt.java

Source

package com.suiveg.utils.encryption.algorithms;

import org.apache.commons.lang.StringUtils;

import java.util.Random;

/**
 * *************************************************************************
 * Java-based implementation of the unix crypt(3) command
 * Based upon C source code written by Eric Young
 * Can be located at http://locutus.kingwoodcable.com/jfd/crypt.html
 * Eric's original code is licensed under the BSD license.  As this is derivative, the same license applies.
 * **************************************************************************
 *
 * - I've modified this code a bit to be 1.6 compatible, and made it a bit faster + fixed a number of quirks
 * - I did also create a generateSalt()
 *
 * @author unknown
 * @author <a href="mailto:eay@psych.uq.oz.au">Eric Young</a>
 * @author <a href="mailto:vegaasen@gmail.com">Vegard Aasen</a>
 * @author <a href="mailto:marius.kristensen@gmail.com">Marius Kristensen</a>
 * @since 0.2-SNAPSHOT
 */

public class Crypt {

    private Crypt() {
    }

    public static final String alphabet = "./0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz";

    private static final int ITERATIONS = 16;

    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[][] = { {
            /* for C bits (numbered as per FIPS 46) 1 2 3 4 5 6 */
            0x00000000, 0x00000010, 0x20000000, 0x20000010, 0x00010000, 0x00010010, 0x20010000, 0x20010010,
            0x00000800, 0x00000810, 0x20000800, 0x20000810, 0x00010800, 0x00010810, 0x20010800, 0x20010810,
            0x00000020, 0x00000030, 0x20000020, 0x20000030, 0x00010020, 0x00010030, 0x20010020, 0x20010030,
            0x00000820, 0x00000830, 0x20000820, 0x20000830, 0x00010820, 0x00010830, 0x20010820, 0x20010830,
            0x00080000, 0x00080010, 0x20080000, 0x20080010, 0x00090000, 0x00090010, 0x20090000, 0x20090010,
            0x00080800, 0x00080810, 0x20080800, 0x20080810, 0x00090800, 0x00090810, 0x20090800, 0x20090810,
            0x00080020, 0x00080030, 0x20080020, 0x20080030, 0x00090020, 0x00090030, 0x20090020, 0x20090030,
            0x00080820, 0x00080830, 0x20080820, 0x20080830, 0x00090820, 0x00090830, 0x20090820, 0x20090830, },
            {
                    /* for C bits (numbered as per FIPS 46) 7 8 10 11 12 13 */
                    0x00000000, 0x02000000, 0x00002000, 0x02002000, 0x00200000, 0x02200000, 0x00202000, 0x02202000,
                    0x00000004, 0x02000004, 0x00002004, 0x02002004, 0x00200004, 0x02200004, 0x00202004, 0x02202004,
                    0x00000400, 0x02000400, 0x00002400, 0x02002400, 0x00200400, 0x02200400, 0x00202400, 0x02202400,
                    0x00000404, 0x02000404, 0x00002404, 0x02002404, 0x00200404, 0x02200404, 0x00202404, 0x02202404,
                    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, },
            {
                    /* for C bits (numbered as per FIPS 46) 14 15 16 17 19 20 */
                    0x00000000, 0x00000001, 0x00040000, 0x00040001, 0x01000000, 0x01000001, 0x01040000, 0x01040001,
                    0x00000002, 0x00000003, 0x00040002, 0x00040003, 0x01000002, 0x01000003, 0x01040002, 0x01040003,
                    0x00000200, 0x00000201, 0x00040200, 0x00040201, 0x01000200, 0x01000201, 0x01040200, 0x01040201,
                    0x00000202, 0x00000203, 0x00040202, 0x00040203, 0x01000202, 0x01000203, 0x01040202, 0x01040203,
                    0x08000000, 0x08000001, 0x08040000, 0x08040001, 0x09000000, 0x09000001, 0x09040000, 0x09040001,
                    0x08000002, 0x08000003, 0x08040002, 0x08040003, 0x09000002, 0x09000003, 0x09040002, 0x09040003,
                    0x08000200, 0x08000201, 0x08040200, 0x08040201, 0x09000200, 0x09000201, 0x09040200, 0x09040201,
                    0x08000202, 0x08000203, 0x08040202, 0x08040203, 0x09000202, 0x09000203, 0x09040202,
                    0x09040203, },
            {
                    /* for C bits (numbered as per FIPS 46) 21 23 24 26 27 28 */
                    0x00000000, 0x00100000, 0x00000100, 0x00100100, 0x00000008, 0x00100008, 0x00000108, 0x00100108,
                    0x00001000, 0x00101000, 0x00001100, 0x00101100, 0x00001008, 0x00101008, 0x00001108, 0x00101108,
                    0x04000000, 0x04100000, 0x04000100, 0x04100100, 0x04000008, 0x04100008, 0x04000108, 0x04100108,
                    0x04001000, 0x04101000, 0x04001100, 0x04101100, 0x04001008, 0x04101008, 0x04001108, 0x04101108,
                    0x00020000, 0x00120000, 0x00020100, 0x00120100, 0x00020008, 0x00120008, 0x00020108, 0x00120108,
                    0x00021000, 0x00121000, 0x00021100, 0x00121100, 0x00021008, 0x00121008, 0x00021108, 0x00121108,
                    0x04020000, 0x04120000, 0x04020100, 0x04120100, 0x04020008, 0x04120008, 0x04020108, 0x04120108,
                    0x04021000, 0x04121000, 0x04021100, 0x04121100, 0x04021008, 0x04121008, 0x04021108,
                    0x04121108, },
            {
                    /* for D bits (numbered as per FIPS 46) 1 2 3 4 5 6 */
                    0x00000000, 0x10000000, 0x00010000, 0x10010000, 0x00000004, 0x10000004, 0x00010004, 0x10010004,
                    0x20000000, 0x30000000, 0x20010000, 0x30010000, 0x20000004, 0x30000004, 0x20010004, 0x30010004,
                    0x00100000, 0x10100000, 0x00110000, 0x10110000, 0x00100004, 0x10100004, 0x00110004, 0x10110004,
                    0x20100000, 0x30100000, 0x20110000, 0x30110000, 0x20100004, 0x30100004, 0x20110004, 0x30110004,
                    0x00001000, 0x10001000, 0x00011000, 0x10011000, 0x00001004, 0x10001004, 0x00011004, 0x10011004,
                    0x20001000, 0x30001000, 0x20011000, 0x30011000, 0x20001004, 0x30001004, 0x20011004, 0x30011004,
                    0x00101000, 0x10101000, 0x00111000, 0x10111000, 0x00101004, 0x10101004, 0x00111004, 0x10111004,
                    0x20101000, 0x30101000, 0x20111000, 0x30111000, 0x20101004, 0x30101004, 0x20111004,
                    0x30111004, },
            {
                    /* for D bits (numbered as per FIPS 46) 8 9 11 12 13 14 */
                    0x00000000, 0x08000000, 0x00000008, 0x08000008, 0x00000400, 0x08000400, 0x00000408, 0x08000408,
                    0x00020000, 0x08020000, 0x00020008, 0x08020008, 0x00020400, 0x08020400, 0x00020408, 0x08020408,
                    0x00000001, 0x08000001, 0x00000009, 0x08000009, 0x00000401, 0x08000401, 0x00000409, 0x08000409,
                    0x00020001, 0x08020001, 0x00020009, 0x08020009, 0x00020401, 0x08020401, 0x00020409, 0x08020409,
                    0x02000000, 0x0A000000, 0x02000008, 0x0A000008, 0x02000400, 0x0A000400, 0x02000408, 0x0A000408,
                    0x02020000, 0x0A020000, 0x02020008, 0x0A020008, 0x02020400, 0x0A020400, 0x02020408, 0x0A020408,
                    0x02000001, 0x0A000001, 0x02000009, 0x0A000009, 0x02000401, 0x0A000401, 0x02000409, 0x0A000409,
                    0x02020001, 0x0A020001, 0x02020009, 0x0A020009, 0x02020401, 0x0A020401, 0x02020409,
                    0x0A020409, },
            {
                    /* for D bits (numbered as per FIPS 46) 16 17 18 19 20 21 */
                    0x00000000, 0x00000100, 0x00080000, 0x00080100, 0x01000000, 0x01000100, 0x01080000, 0x01080100,
                    0x00000010, 0x00000110, 0x00080010, 0x00080110, 0x01000010, 0x01000110, 0x01080010, 0x01080110,
                    0x00200000, 0x00200100, 0x00280000, 0x00280100, 0x01200000, 0x01200100, 0x01280000, 0x01280100,
                    0x00200010, 0x00200110, 0x00280010, 0x00280110, 0x01200010, 0x01200110, 0x01280010, 0x01280110,
                    0x00000200, 0x00000300, 0x00080200, 0x00080300, 0x01000200, 0x01000300, 0x01080200, 0x01080300,
                    0x00000210, 0x00000310, 0x00080210, 0x00080310, 0x01000210, 0x01000310, 0x01080210, 0x01080310,
                    0x00200200, 0x00200300, 0x00280200, 0x00280300, 0x01200200, 0x01200300, 0x01280200, 0x01280300,
                    0x00200210, 0x00200310, 0x00280210, 0x00280310, 0x01200210, 0x01200310, 0x01280210,
                    0x01280310, },
            {
                    /* for D bits (numbered as per FIPS 46) 22 23 24 25 27 28 */
                    0x00000000, 0x04000000, 0x00040000, 0x04040000, 0x00000002, 0x04000002, 0x00040002, 0x04040002,
                    0x00002000, 0x04002000, 0x00042000, 0x04042000, 0x00002002, 0x04002002, 0x00042002, 0x04042002,
                    0x00000020, 0x04000020, 0x00040020, 0x04040020, 0x00000022, 0x04000022, 0x00040022, 0x04040022,
                    0x00002020, 0x04002020, 0x00042020, 0x04042020, 0x00002022, 0x04002022, 0x00042022, 0x04042022,
                    0x00000800, 0x04000800, 0x00040800, 0x04040800, 0x00000802, 0x04000802, 0x00040802, 0x04040802,
                    0x00002800, 0x04002800, 0x00042800, 0x04042800, 0x00002802, 0x04002802, 0x00042802, 0x04042802,
                    0x00000820, 0x04000820, 0x00040820, 0x04040820, 0x00000822, 0x04000822, 0x00040822, 0x04040822,
                    0x00002820, 0x04002820, 0x00042820, 0x04042820, 0x00002822, 0x04002822, 0x00042822,
                    0x04042822, } };

    private static final int SPtrans[][] = { {
            /* nibble 0 */
            0x00820200, 0x00020000, 0x80800000, 0x80820200, 0x00800000, 0x80020200, 0x80020000, 0x80800000,
            0x80020200, 0x00820200, 0x00820000, 0x80000200, 0x80800200, 0x00800000, 0x00000000, 0x80020000,
            0x00020000, 0x80000000, 0x00800200, 0x00020200, 0x80820200, 0x00820000, 0x80000200, 0x00800200,
            0x80000000, 0x00000200, 0x00020200, 0x80820000, 0x00000200, 0x80800200, 0x80820000, 0x00000000,
            0x00000000, 0x80820200, 0x00800200, 0x80020000, 0x00820200, 0x00020000, 0x80000200, 0x00800200,
            0x80820000, 0x00000200, 0x00020200, 0x80800000, 0x80020200, 0x80000000, 0x80800000, 0x00820000,
            0x80820200, 0x00020200, 0x00820000, 0x80800200, 0x00800000, 0x80000200, 0x80020000, 0x00000000,
            0x00020000, 0x00800000, 0x80800200, 0x00820200, 0x80000000, 0x80820000, 0x00000200, 0x80020200, },
            {
                    /* nibble 1 */
                    0x10042004, 0x00000000, 0x00042000, 0x10040000, 0x10000004, 0x00002004, 0x10002000, 0x00042000,
                    0x00002000, 0x10040004, 0x00000004, 0x10002000, 0x00040004, 0x10042000, 0x10040000, 0x00000004,
                    0x00040000, 0x10002004, 0x10040004, 0x00002000, 0x00042004, 0x10000000, 0x00000000, 0x00040004,
                    0x10002004, 0x00042004, 0x10042000, 0x10000004, 0x10000000, 0x00040000, 0x00002004, 0x10042004,
                    0x00040004, 0x10042000, 0x10002000, 0x00042004, 0x10042004, 0x00040004, 0x10000004, 0x00000000,
                    0x10000000, 0x00002004, 0x00040000, 0x10040004, 0x00002000, 0x10000000, 0x00042004, 0x10002004,
                    0x10042000, 0x00002000, 0x00000000, 0x10000004, 0x00000004, 0x10042004, 0x00042000, 0x10040000,
                    0x10040004, 0x00040000, 0x00002004, 0x10002000, 0x10002004, 0x00000004, 0x10040000,
                    0x00042000, },
            {
                    /* nibble 2 */
                    0x41000000, 0x01010040, 0x00000040, 0x41000040, 0x40010000, 0x01000000, 0x41000040, 0x00010040,
                    0x01000040, 0x00010000, 0x01010000, 0x40000000, 0x41010040, 0x40000040, 0x40000000, 0x41010000,
                    0x00000000, 0x40010000, 0x01010040, 0x00000040, 0x40000040, 0x41010040, 0x00010000, 0x41000000,
                    0x41010000, 0x01000040, 0x40010040, 0x01010000, 0x00010040, 0x00000000, 0x01000000, 0x40010040,
                    0x01010040, 0x00000040, 0x40000000, 0x00010000, 0x40000040, 0x40010000, 0x01010000, 0x41000040,
                    0x00000000, 0x01010040, 0x00010040, 0x41010000, 0x40010000, 0x01000000, 0x41010040, 0x40000000,
                    0x40010040, 0x41000000, 0x01000000, 0x41010040, 0x00010000, 0x01000040, 0x41000040, 0x00010040,
                    0x01000040, 0x00000000, 0x41010000, 0x40000040, 0x41000000, 0x40010040, 0x00000040,
                    0x01010000, },
            {
                    /* nibble 3 */
                    0x00100402, 0x04000400, 0x00000002, 0x04100402, 0x00000000, 0x04100000, 0x04000402, 0x00100002,
                    0x04100400, 0x04000002, 0x04000000, 0x00000402, 0x04000002, 0x00100402, 0x00100000, 0x04000000,
                    0x04100002, 0x00100400, 0x00000400, 0x00000002, 0x00100400, 0x04000402, 0x04100000, 0x00000400,
                    0x00000402, 0x00000000, 0x00100002, 0x04100400, 0x04000400, 0x04100002, 0x04100402, 0x00100000,
                    0x04100002, 0x00000402, 0x00100000, 0x04000002, 0x00100400, 0x04000400, 0x00000002, 0x04100000,
                    0x04000402, 0x00000000, 0x00000400, 0x00100002, 0x00000000, 0x04100002, 0x04100400, 0x00000400,
                    0x04000000, 0x04100402, 0x00100402, 0x00100000, 0x04100402, 0x00000002, 0x04000400, 0x00100402,
                    0x00100002, 0x00100400, 0x04100000, 0x04000402, 0x00000402, 0x04000000, 0x04000002,
                    0x04100400, },
            {
                    /* nibble 4 */
                    0x02000000, 0x00004000, 0x00000100, 0x02004108, 0x02004008, 0x02000100, 0x00004108, 0x02004000,
                    0x00004000, 0x00000008, 0x02000008, 0x00004100, 0x02000108, 0x02004008, 0x02004100, 0x00000000,
                    0x00004100, 0x02000000, 0x00004008, 0x00000108, 0x02000100, 0x00004108, 0x00000000, 0x02000008,
                    0x00000008, 0x02000108, 0x02004108, 0x00004008, 0x02004000, 0x00000100, 0x00000108, 0x02004100,
                    0x02004100, 0x02000108, 0x00004008, 0x02004000, 0x00004000, 0x00000008, 0x02000008, 0x02000100,
                    0x02000000, 0x00004100, 0x02004108, 0x00000000, 0x00004108, 0x02000000, 0x00000100, 0x00004008,
                    0x02000108, 0x00000100, 0x00000000, 0x02004108, 0x02004008, 0x02004100, 0x00000108, 0x00004000,
                    0x00004100, 0x02004008, 0x02000100, 0x00000108, 0x00000008, 0x00004108, 0x02004000,
                    0x02000008, },
            {
                    /* nibble 5 */
                    0x20000010, 0x00080010, 0x00000000, 0x20080800, 0x00080010, 0x00000800, 0x20000810, 0x00080000,
                    0x00000810, 0x20080810, 0x00080800, 0x20000000, 0x20000800, 0x20000010, 0x20080000, 0x00080810,
                    0x00080000, 0x20000810, 0x20080010, 0x00000000, 0x00000800, 0x00000010, 0x20080800, 0x20080010,
                    0x20080810, 0x20080000, 0x20000000, 0x00000810, 0x00000010, 0x00080800, 0x00080810, 0x20000800,
                    0x00000810, 0x20000000, 0x20000800, 0x00080810, 0x20080800, 0x00080010, 0x00000000, 0x20000800,
                    0x20000000, 0x00000800, 0x20080010, 0x00080000, 0x00080010, 0x20080810, 0x00080800, 0x00000010,
                    0x20080810, 0x00080800, 0x00080000, 0x20000810, 0x20000010, 0x20080000, 0x00080810, 0x00000000,
                    0x00000800, 0x20000010, 0x20000810, 0x20080800, 0x20080000, 0x00000810, 0x00000010,
                    0x20080010, },
            {
                    /* nibble 6 */
                    0x00001000, 0x00000080, 0x00400080, 0x00400001, 0x00401081, 0x00001001, 0x00001080, 0x00000000,
                    0x00400000, 0x00400081, 0x00000081, 0x00401000, 0x00000001, 0x00401080, 0x00401000, 0x00000081,
                    0x00400081, 0x00001000, 0x00001001, 0x00401081, 0x00000000, 0x00400080, 0x00400001, 0x00001080,
                    0x00401001, 0x00001081, 0x00401080, 0x00000001, 0x00001081, 0x00401001, 0x00000080, 0x00400000,
                    0x00001081, 0x00401000, 0x00401001, 0x00000081, 0x00001000, 0x00000080, 0x00400000, 0x00401001,
                    0x00400081, 0x00001081, 0x00001080, 0x00000000, 0x00000080, 0x00400001, 0x00000001, 0x00400080,
                    0x00000000, 0x00400081, 0x00400080, 0x00001080, 0x00000081, 0x00001000, 0x00401081, 0x00400000,
                    0x00401080, 0x00000001, 0x00001001, 0x00401081, 0x00400001, 0x00401080, 0x00401000,
                    0x00001001, },
            {
                    /* nibble 7 */
                    0x08200020, 0x08208000, 0x00008020, 0x00000000, 0x08008000, 0x00200020, 0x08200000, 0x08208020,
                    0x00000020, 0x08000000, 0x00208000, 0x00008020, 0x00208020, 0x08008020, 0x08000020, 0x08200000,
                    0x00008000, 0x00208020, 0x00200020, 0x08008000, 0x08208020, 0x08000020, 0x00000000, 0x00208000,
                    0x08000000, 0x00200000, 0x08008020, 0x08200020, 0x00200000, 0x00008000, 0x08208000, 0x00000020,
                    0x00200000, 0x00008000, 0x08000020, 0x08208020, 0x00008020, 0x08000000, 0x00000000, 0x00208000,
                    0x08200020, 0x08008020, 0x08008000, 0x00200020, 0x08208000, 0x00000020, 0x00200020, 0x08008000,
                    0x08208020, 0x00200000, 0x08200000, 0x08000020, 0x00208000, 0x00008020, 0x08008020, 0x08200000,
                    0x00000020, 0x08208000, 0x00208020, 0x00000000, 0x08000000, 0x08200020, 0x00008000,
                    0x00208020 } };

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

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

    private static 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);
    }

    private static void PERM_OP(int a, int b, int n, int m, int results[]) {
        int t;

        t = ((a >>> n) ^ b) & m;
        a ^= t << n;
        b ^= t;

        results[0] = a;
        results[1] = b;
    }

    private static int HPERM_OP(int a, int n, int m) {
        int t;

        t = ((a << (16 - n)) ^ a) & m;
        a = a ^ t ^ (t >>> (16 - n));

        return a;
    }

    private static int[] des_set_key(byte key[]) {
        int schedule[] = new int[ITERATIONS * 2];

        int c = fourBytesToInt(key, 0);
        int d = fourBytesToInt(key, 4);

        int results[] = new int[2];

        PERM_OP(d, c, 4, 0x0f0f0f0f, 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, 0x00ff00ff, results);
        c = results[0];
        d = results[1];

        PERM_OP(d, c, 1, 0x55555555, results);
        d = results[0];
        c = results[1];

        d = (((d & 0x000000ff) << 16) | (d & 0x0000ff00) | ((d & 0x00ff0000) >>> 16) | ((c & 0xf0000000) >>> 4));
        c &= 0x0fffffff;

        int s, t;
        int j = 0;

        for (int i = 0; i < ITERATIONS; 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 &= 0x0fffffff;
            d &= 0x0fffffff;

            s = skb[0][(c) & 0x3f] | skb[1][((c >>> 6) & 0x03) | ((c >>> 7) & 0x3c)]
                    | skb[2][((c >>> 13) & 0x0f) | ((c >>> 14) & 0x30)]
                    | skb[3][((c >>> 20) & 0x01) | ((c >>> 21) & 0x06) | ((c >>> 22) & 0x38)];

            t = skb[4][(d) & 0x3f] | skb[5][((d >>> 7) & 0x03) | ((d >>> 8) & 0x3c)] | skb[6][(d >>> 15) & 0x3f]
                    | skb[7][((d >>> 21) & 0x0f) | ((d >>> 22) & 0x30)];

            schedule[j++] = ((t << 16) | (s & 0x0000ffff));
            s = ((s >>> 16) | (t & 0xffff0000));

            s = (s << 4) | (s >>> 28);
            schedule[j++] = s;
        }
        return schedule;
    }

    private static int D_ENCRYPT(int L, int R, int S, int E0, int E1, int s[]) {
        int t, u, v;

        v = R ^ (R >>> 16);
        u = v & E0;
        v = v & E1;
        u = (u ^ (u << 16)) ^ R ^ s[S];
        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 int[] body(int schedule[], int Eswap0, int Eswap1) {
        int left = 0;
        int right = 0;
        int t;

        for (int j = 0; j < 25; j++) {
            for (int i = 0; i < ITERATIONS * 2; 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, 0x00ff00ff, 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, 0x0000ffff, results);
        left = results[0];
        right = results[1];

        PERM_OP(right, left, 4, 0x0f0f0f0f, results);
        right = results[0];
        left = results[1];

        int out[] = new int[2];

        out[0] = left;
        out[1] = right;

        return out;
    }

    /**
     * Generate a salt based on Alpha-chars
     *
     * @return generated salt
     */
    public static String generateSalt() {
        String salt = "";
        Random r = new Random();

        while (salt.length() < 2) {
            salt += alphabet.charAt(r.nextInt(alphabet.length()));
        }

        return salt;
    }

    /**
     * Using Crypt(3), generate a string based on a salt and the actual password that
     * should be hashed.
     *
     * @param salt (optional) - if the salt has not been supplied, a random salt will be generated.
     * @param original (required) the actual password as a string
     * @return the generated String as crypt-hashed
     */
    public static String cryptUsingStandardDES(String salt, final String original) {
        if (StringUtils.isEmpty(salt)) {
            salt = generateSalt();
        }

        char[] buffer = new char[13];

        char charZero = salt.charAt(0);
        char charOne = salt.charAt(1);

        buffer[0] = charZero;
        buffer[1] = charOne;

        int Eswap0 = alphabet.indexOf(charZero);
        int Eswap1 = alphabet.indexOf(charOne) << 4;
        byte key[] = new byte[8];

        for (int i = 0; i < key.length; i++)
            key[i] = (byte) 0;

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

        for (int i = 2, y = 0, u = 0x80; i < 13; i++) {
            for (int j = 0, c = 0; j < 6; j++) {
                c <<= 1;

                if (((int) b[y] & u) != 0)
                    c |= 1;

                u >>>= 1;

                if (u == 0) {
                    y++;
                    u = 0x80;
                }
                buffer[i] = alphabet.charAt(c);
            }
        }
        return new String(buffer);
    }
}