/*
 * Ported from Flashlight VNC ActionScript implementation:
 *     http://www.wizhelp.com/flashlight-vnc/
 *
 * Full attribution follows:
 *
 * -------------------------------------------------------------------------
 *
 * This DES class has been extracted from package Acme.Crypto for use in VNC.
 * The unnecessary odd parity code has been removed.
 *
 * These changes are:
 *  Copyright (C) 1999 AT&T Laboratories Cambridge.  All Rights Reserved.
 *
 * This software 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.
 *

 * DesCipher - the DES encryption method
 *
 * The meat of this code is by Dave Zimmerman <dzimm@widget.com>, and is:
 *
 * Copyright (c) 1996 Widget Workshop, Inc. All Rights Reserved.
 *
 * Permission to use, copy, modify, and distribute this software
 * and its documentation for NON-COMMERCIAL or COMMERCIAL purposes and
 * without fee is hereby granted, provided that this copyright notice is kept
 * intact.
 *
 * WIDGET WORKSHOP MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY
 * OF THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
 * TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE, OR NON-INFRINGEMENT. WIDGET WORKSHOP SHALL NOT BE LIABLE
 * FOR ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
 *
 * THIS SOFTWARE IS NOT DESIGNED OR INTENDED FOR USE OR RESALE AS ON-LINE
 * CONTROL EQUIPMENT IN HAZARDOUS ENVIRONMENTS REQUIRING FAIL-SAFE
 * PERFORMANCE, SUCH AS IN THE OPERATION OF NUCLEAR FACILITIES, AIRCRAFT
 * NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL, DIRECT LIFE
 * SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH THE FAILURE OF THE
 * SOFTWARE COULD LEAD DIRECTLY TO DEATH, PERSONAL INJURY, OR SEVERE
 * PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH RISK ACTIVITIES").  WIDGET WORKSHOP
 * SPECIFICALLY DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR
 * HIGH RISK ACTIVITIES.
 *
 *
 * The rest is:
 *
 * Copyright (C) 1996 by Jef Poskanzer <jef@acme.com>.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 * Visit the ACME Labs Java page for up-to-date versions of this and other
 * fine Java utilities: http://www.acme.com/java/
 */

export default function DES(passwd) {
    "use strict";

    // Tables, permutations, S-boxes, etc.
    const PC2 = [13,16,10,23, 0, 4, 2,27,14, 5,20, 9,22,18,11, 3,
                 25, 7,15, 6,26,19,12, 1,40,51,30,36,46,54,29,39,
                 50,44,32,47,43,48,38,55,33,52,45,41,49,35,28,31 ],
        totrot = [ 1, 2, 4, 6, 8,10,12,14,15,17,19,21,23,25,27,28],
        z = 0x0,
        keys = [];
    let a,b,c,d,e,f;

    a=1<<16; b=1<<24; c=a|b; d=1<<2; e=1<<10; f=d|e;
    const SP1 = [c|e,z|z,a|z,c|f,c|d,a|f,z|d,a|z,z|e,c|e,c|f,z|e,b|f,c|d,b|z,z|d,
                 z|f,b|e,b|e,a|e,a|e,c|z,c|z,b|f,a|d,b|d,b|d,a|d,z|z,z|f,a|f,b|z,
                 a|z,c|f,z|d,c|z,c|e,b|z,b|z,z|e,c|d,a|z,a|e,b|d,z|e,z|d,b|f,a|f,
                 c|f,a|d,c|z,b|f,b|d,z|f,a|f,c|e,z|f,b|e,b|e,z|z,a|d,a|e,z|z,c|d];
    a=1<<20; b=1<<31; c=a|b; d=1<<5; e=1<<15; f=d|e;
    const SP2 = [c|f,b|e,z|e,a|f,a|z,z|d,c|d,b|f,b|d,c|f,c|e,b|z,b|e,a|z,z|d,c|d,
                 a|e,a|d,b|f,z|z,b|z,z|e,a|f,c|z,a|d,b|d,z|z,a|e,z|f,c|e,c|z,z|f,
                 z|z,a|f,c|d,a|z,b|f,c|z,c|e,z|e,c|z,b|e,z|d,c|f,a|f,z|d,z|e,b|z,
                 z|f,c|e,a|z,b|d,a|d,b|f,b|d,a|d,a|e,z|z,b|e,z|f,b|z,c|d,c|f,a|e];
    a=1<<17; b=1<<27; c=a|b; d=1<<3; e=1<<9; f=d|e;
    const SP3 = [z|f,c|e,z|z,c|d,b|e,z|z,a|f,b|e,a|d,b|d,b|d,a|z,c|f,a|d,c|z,z|f,
                 b|z,z|d,c|e,z|e,a|e,c|z,c|d,a|f,b|f,a|e,a|z,b|f,z|d,c|f,z|e,b|z,
                 c|e,b|z,a|d,z|f,a|z,c|e,b|e,z|z,z|e,a|d,c|f,b|e,b|d,z|e,z|z,c|d,
                 b|f,a|z,b|z,c|f,z|d,a|f,a|e,b|d,c|z,b|f,z|f,c|z,a|f,z|d,c|d,a|e];
    a=1<<13; b=1<<23; c=a|b; d=1<<0; e=1<<7; f=d|e;
    const SP4 = [c|d,a|f,a|f,z|e,c|e,b|f,b|d,a|d,z|z,c|z,c|z,c|f,z|f,z|z,b|e,b|d,
                 z|d,a|z,b|z,c|d,z|e,b|z,a|d,a|e,b|f,z|d,a|e,b|e,a|z,c|e,c|f,z|f,
                 b|e,b|d,c|z,c|f,z|f,z|z,z|z,c|z,a|e,b|e,b|f,z|d,c|d,a|f,a|f,z|e,
                 c|f,z|f,z|d,a|z,b|d,a|d,c|e,b|f,a|d,a|e,b|z,c|d,z|e,b|z,a|z,c|e];
    a=1<<25; b=1<<30; c=a|b; d=1<<8; e=1<<19; f=d|e;
    const SP5 = [z|d,a|f,a|e,c|d,z|e,z|d,b|z,a|e,b|f,z|e,a|d,b|f,c|d,c|e,z|f,b|z,
                 a|z,b|e,b|e,z|z,b|d,c|f,c|f,a|d,c|e,b|d,z|z,c|z,a|f,a|z,c|z,z|f,
                 z|e,c|d,z|d,a|z,b|z,a|e,c|d,b|f,a|d,b|z,c|e,a|f,b|f,z|d,a|z,c|e,
                 c|f,z|f,c|z,c|f,a|e,z|z,b|e,c|z,z|f,a|d,b|d,z|e,z|z,b|e,a|f,b|d];
    a=1<<22; b=1<<29; c=a|b; d=1<<4; e=1<<14; f=d|e;
    const SP6 = [b|d,c|z,z|e,c|f,c|z,z|d,c|f,a|z,b|e,a|f,a|z,b|d,a|d,b|e,b|z,z|f,
                 z|z,a|d,b|f,z|e,a|e,b|f,z|d,c|d,c|d,z|z,a|f,c|e,z|f,a|e,c|e,b|z,
                 b|e,z|d,c|d,a|e,c|f,a|z,z|f,b|d,a|z,b|e,b|z,z|f,b|d,c|f,a|e,c|z,
                 a|f,c|e,z|z,c|d,z|d,z|e,c|z,a|f,z|e,a|d,b|f,z|z,c|e,b|z,a|d,b|f];
    a=1<<21; b=1<<26; c=a|b; d=1<<1; e=1<<11; f=d|e;
    const SP7 = [a|z,c|d,b|f,z|z,z|e,b|f,a|f,c|e,c|f,a|z,z|z,b|d,z|d,b|z,c|d,z|f,
                 b|e,a|f,a|d,b|e,b|d,c|z,c|e,a|d,c|z,z|e,z|f,c|f,a|e,z|d,b|z,a|e,
                 b|z,a|e,a|z,b|f,b|f,c|d,c|d,z|d,a|d,b|z,b|e,a|z,c|e,z|f,a|f,c|e,
                 z|f,b|d,c|f,c|z,a|e,z|z,z|d,c|f,z|z,a|f,c|z,z|e,b|d,b|e,z|e,a|d];
    a=1<<18; b=1<<28; c=a|b; d=1<<6; e=1<<12; f=d|e;
    const SP8 = [b|f,z|e,a|z,c|f,b|z,b|f,z|d,b|z,a|d,c|z,c|f,a|e,c|e,a|f,z|e,z|d,
                 c|z,b|d,b|e,z|f,a|e,a|d,c|d,c|e,z|f,z|z,z|z,c|d,b|d,b|e,a|f,a|z,
                 a|f,a|z,c|e,z|e,z|d,c|d,z|e,a|f,b|e,z|d,b|d,c|z,c|d,b|z,a|z,b|f,
                 z|z,c|f,a|d,b|d,c|z,b|e,b|f,z|z,c|f,a|e,a|e,z|f,z|f,a|d,b|z,c|e];

    // Set the key.
    function setKeys(keyBlock) {
        const pc1m = [], pcr = [], kn = [];

        for (let j = 0, l = 56; j < 56; ++j, l -= 8) {
            l += l < -5 ? 65 : l < -3 ? 31 : l < -1 ? 63 : l === 27 ? 35 : 0; // PC1
            const m = l & 0x7;
            pc1m[j] = ((keyBlock[l >>> 3] & (1<<m)) !== 0) ? 1: 0;
        }

        for (let i = 0; i < 16; ++i) {
            const m = i << 1;
            const n = m + 1;
            kn[m] = kn[n] = 0;
            for (let o = 28; o < 59; o += 28) {
                for (let j = o - 28; j < o; ++j) {
                    const l = j + totrot[i];
                    pcr[j] = l < o ? pc1m[l] : pc1m[l - 28];
                }
            }
            for (let j = 0; j < 24; ++j) {
                if (pcr[PC2[j]] !== 0) {
                    kn[m] |= 1 << (23 - j);
                }
                if (pcr[PC2[j + 24]] !== 0) {
                    kn[n] |= 1 << (23 - j);
                }
            }
        }

        // cookey
        for (let i = 0, rawi = 0, KnLi = 0; i < 16; ++i) {
            const raw0 = kn[rawi++];
            const raw1 = kn[rawi++];
            keys[KnLi] = (raw0 & 0x00fc0000) << 6;
            keys[KnLi] |= (raw0 & 0x00000fc0) << 10;
            keys[KnLi] |= (raw1 & 0x00fc0000) >>> 10;
            keys[KnLi] |= (raw1 & 0x00000fc0) >>> 6;
            ++KnLi;
            keys[KnLi] = (raw0 & 0x0003f000) << 12;
            keys[KnLi] |= (raw0 & 0x0000003f) << 16;
            keys[KnLi] |= (raw1 & 0x0003f000) >>> 4;
            keys[KnLi] |= (raw1 & 0x0000003f);
            ++KnLi;
        }
    }

    // Encrypt 8 bytes of text
    function enc8(text) {
        const b = text.slice();
        let i = 0, l, r, x; // left, right, accumulator

        // Squash 8 bytes to 2 ints
        l = b[i++]<<24 | b[i++]<<16 | b[i++]<<8 | b[i++];
        r = b[i++]<<24 | b[i++]<<16 | b[i++]<<8 | b[i++];

        x = ((l >>> 4) ^ r) & 0x0f0f0f0f;
        r ^= x;
        l ^= (x << 4);
        x = ((l >>> 16) ^ r) & 0x0000ffff;
        r ^= x;
        l ^= (x << 16);
        x = ((r >>> 2) ^ l) & 0x33333333;
        l ^= x;
        r ^= (x << 2);
        x = ((r >>> 8) ^ l) & 0x00ff00ff;
        l ^= x;
        r ^= (x << 8);
        r = (r << 1) | ((r >>> 31) & 1);
        x = (l ^ r) & 0xaaaaaaaa;
        l ^= x;
        r ^= x;
        l = (l << 1) | ((l >>> 31) & 1);

        for (let i = 0, keysi = 0; i < 8; ++i) {
            x = (r << 28) | (r >>> 4);
            x ^= keys[keysi++];
            let fval =  SP7[x & 0x3f];
            fval |= SP5[(x >>> 8) & 0x3f];
            fval |= SP3[(x >>> 16) & 0x3f];
            fval |= SP1[(x >>> 24) & 0x3f];
            x = r ^ keys[keysi++];
            fval |= SP8[x & 0x3f];
            fval |= SP6[(x >>> 8) & 0x3f];
            fval |= SP4[(x >>> 16) & 0x3f];
            fval |= SP2[(x >>> 24) & 0x3f];
            l ^= fval;
            x = (l << 28) | (l >>> 4);
            x ^= keys[keysi++];
            fval =  SP7[x & 0x3f];
            fval |= SP5[(x >>> 8) & 0x3f];
            fval |= SP3[(x >>> 16) & 0x3f];
            fval |= SP1[(x >>> 24) & 0x3f];
            x = l ^ keys[keysi++];
            fval |= SP8[x & 0x0000003f];
            fval |= SP6[(x >>> 8) & 0x3f];
            fval |= SP4[(x >>> 16) & 0x3f];
            fval |= SP2[(x >>> 24) & 0x3f];
            r ^= fval;
        }

        r = (r << 31) | (r >>> 1);
        x = (l ^ r) & 0xaaaaaaaa;
        l ^= x;
        r ^= x;
        l = (l << 31) | (l >>> 1);
        x = ((l >>> 8) ^ r) & 0x00ff00ff;
        r ^= x;
        l ^= (x << 8);
        x = ((l >>> 2) ^ r) & 0x33333333;
        r ^= x;
        l ^= (x << 2);
        x = ((r >>> 16) ^ l) & 0x0000ffff;
        l ^= x;
        r ^= (x << 16);
        x = ((r >>> 4) ^ l) & 0x0f0f0f0f;
        l ^= x;
        r ^= (x << 4);

        // Spread ints to bytes
        x = [r, l];
        for (i = 0; i < 8; i++) {
            b[i] = (x[i>>>2] >>> (8 * (3 - (i % 4)))) % 256;
            if (b[i] < 0) { b[i] += 256; } // unsigned
        }
        return b;
    }

    // Encrypt 16 bytes of text using passwd as key
    function encrypt(t) {
        return enc8(t.slice(0, 8)).concat(enc8(t.slice(8, 16)));
    }

    setKeys(passwd);             // Setup keys
    return {'encrypt': encrypt}; // Public interface

}
