/*
   * 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/
   */
  
  "use strict";
  /*jslint white: false, bitwise: false, plusplus: false */
  
  function DES(passwd) {
  
  // Tables, permutations, S-boxes, etc.
  var 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, a,b,c,d,e,f, SP1,SP2,SP3,SP4,SP5,SP6,SP7,SP8,
      keys = [];
  
  a=1<<16; b=1<<24; c=a|b; d=1<<2; e=1<<10; f=d|e;
  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;
  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;
  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;
  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;
  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;
  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;
  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;
  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) {
      var i, j, l, m, n, o, pc1m = [], pcr = [], kn = [],
          raw0, raw1, rawi, KnLi;
  
      for (j = 0, l = 56; j < 56; ++j, l-=8) {
          l += l<-5 ? 65 : l<-3 ? 31 : l<-1 ? 63 : l===27 ? 35 : 0; // PC1
          m = l & 0x7;
          pc1m[j] = ((keyBlock[l >>> 3] & (1<<m)) !== 0) ? 1: 0;
      }
  
      for (i = 0; i < 16; ++i) {
          m = i << 1;
          n = m + 1;
          kn[m] = kn[n] = 0;
          for (o=28; o<59; o+=28) {
              for (j = o-28; j < o; ++j) {
                  l = j + totrot[i];
                  if (l < o) {
                      pcr[j] = pc1m[l];
                  } else {
                      pcr[j] = pc1m[l - 28];
                  }
              }
          }
          for (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 (i = 0, rawi = 0, KnLi = 0; i < 16; ++i) {
          raw0 = kn[rawi++];
          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) {
      var i = 0, b = text.slice(), fval, keysi = 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 (i = 0; i < 8; ++i) {
          x = (r << 28) | (r >>> 4);
          x ^= keys[keysi++];
          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
  
  } // function DES