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    1: <script type="text/javascript" language="JavaScript">
    2: // <![CDATA[
    3: // The LearningOnline Network with CAPA
    4: // Encryption Routines according to Data Encryption Standard DES
    5: // Federal Information Processing Standards Publication 46-2 (1993 Dec 30)
    6: //
    7: // $Id: londes.js,v 1.9 2009/05/22 17:01:28 bisitz Exp $
    8: //
    9: // Copyright Michigan State University Board of Trustees
   10: //
   11: // This file is part of the LearningOnline Network with CAPA (LON-CAPA).
   12: //
   13: // LON-CAPA is free software; you can redistribute it and/or modify
   14: // it under the terms of the GNU General Public License as published by
   15: // the Free Software Foundation; either version 2 of the License, or
   16: // (at your option) any later version.
   17: //
   18: // LON-CAPA is distributed in the hope that it will be useful,
   19: // but WITHOUT ANY WARRANTY; without even the implied warranty of
   20: // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   21: // GNU General Public License for more details.
   22: //
   23: // You should have received a copy of the GNU General Public License
   24: // along with LON-CAPA; if not, write to the Free Software
   25: // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
   26: //
   27: // /home/httpd/html/adm/gpl.txt
   28: //
   29: // http://www.lon-capa.org/
   30: //
   31: // JavaScript Implementation by Gerd Kortemeyer
   32: // 1997,06/27/00,06/28 Gerd Kortemeyer
   33: 
   34: // Global variables
   35: 
   36: // Array of integers with i-th bit set
   37: var bit=new Array(31);
   38: // Initial permutation IP for right part
   39: var riparr=new Array(31);
   40: // Inverse permutation IP-1
   41: var liiparr=new Array(31);
   42: var uiiparr=new Array(31);
   43: // Key vectors
   44: var uk=new Array(16);
   45: var lk=new Array(16);
   46: // Upper- and lower 32-bit of external key
   47: var uextkey=0;
   48: var lextkey=0;
   49: // Upper- and lower 32-bit of block
   50: var ublock=0;
   51: var lblock=0;
   52: // Upper and lower 24 bit of expanded right vector
   53: var lexpand=0;
   54: var uexpand=0;
   55: // S-box array
   56: var sbarr=new Array(511);
   57: // E expansion
   58: var etarr=new Array(47);
   59: // P permutation
   60: var pparr=new Array(31);
   61: // r- and l-vector
   62: var rv=0;
   63: var lv=0;
   64: // Blocks of data for text
   65: var b0=0;
   66: var b1=0;
   67: var b2=0;
   68: var b3=0;
   69: // Text variable
   70: var text="";
   71: 
   72: // Initialize table arrays and perform self test
   73: 
   74: function init() {
   75:      window.status="Initializing ...";
   76:     var rip="58504234261810 260524436282012 462544638302214 664564840322416 8";
   77:     var iip=" 8162432 7152331 6142230 5132129 4122028 3111927 2101826 1 91725";
   78:      var sb
   79:      sb ="14 413 1 21511 8 310 612 5 9 0 7";
   80:      sb+=" 015 7 414 213 110 61211 9 5 3 8";
   81:      sb+=" 4 114 813 6 2111512 9 7 310 5 0";
   82:      sb+="1512 8 2 4 9 1 7 511 31410 0 613";
   83:      sb+="15 1 814 611 3 4 9 7 21312 0 510";
   84:      sb+=" 313 4 715 2 81412 0 110 6 911 5";
   85:      sb+=" 014 71110 413 1 5 812 6 9 3 215";
   86:      sb+="13 810 1 315 4 211 6 712 0 514 9";
   87:      sb+="10 0 914 6 315 5 11312 711 4 2 8";
   88:      sb+="13 7 0 9 3 4 610 2 8 514121115 1";
   89:      sb+="13 6 4 9 815 3 011 1 212 51014 7";
   90:      sb+=" 11013 0 6 9 8 7 41514 311 5 212";
   91:      sb+=" 71314 3 0 6 910 1 2 8 51112 415";
   92:      sb+="13 811 5 615 0 3 4 7 212 11014 9";
   93:      sb+="10 6 9 01211 71315 1 314 5 2 8 4";
   94:      sb+=" 315 0 610 113 8 9 4 51112 7 214";
   95:      sb+=" 212 4 1 71011 6 8 5 31513 014 9";
   96:      sb+="1411 212 4 713 1 5 01510 3 9 8 6";
   97:      sb+=" 4 2 1111013 7 815 912 5 6 3 014";
   98:      sb+="11 812 7 114 213 615 0 910 4 5 3";
   99:      sb+="12 11015 9 2 6 8 013 3 414 7 511";
  100:      sb+="1015 4 2 712 9 5 6 11314 011 3 8";
  101:      sb+=" 91415 5 2 812 3 7 0 410 11311 6";
  102:      sb+=" 4 3 212 9 515101114 1 7 6 0 813";
  103:      sb+=" 411 21415 0 813 312 9 7 510 6 1";
  104:      sb+="13 011 7 4 9 11014 3 512 215 8 6";
  105:      sb+=" 1 4111312 3 7141015 6 8 0 5 9 2";
  106:      sb+=" 61113 8 1 410 7 9 5 01514 2 312";
  107:      sb+="13 2 8 4 61511 110 9 314 5 012 7";
  108:      sb+=" 11513 810 3 7 412 5 611 014 9 2";
  109:      sb+=" 711 4 1 91214 2 0 6101315 3 5 8";
  110:      sb+=" 2 114 7 410 8131512 9 0 3 5 611";
  111:      var et
  112:      et ="32 1 2 3 4 5 4 5 6 7 8 9 8 910111213121314151617";
  113:      et+="1617181920212021222324252425262728292829303132 1";
  114:      var pp="16 7202129122817 1152326 5183110 2 824143227 3 9191330 62211 425";
  115:      bit[0]=1;
  116:      for (var i=1; i<=31;i++) { bit[i]=bit[i-1]<<1; }
  117:      for (i=0; i<=31;i++) {
  118:         riparr[i]=parseInt(rip.substring(i*2,i*2+2));
  119:         pparr[i]=parseInt(pp.substring(i*2,i*2+2));
  120:      }
  121:      for (i=0;i<=15;i++) {
  122:         liiparr[i]=parseInt(iip.substring(i*2,i*2+2));
  123:         uiiparr[i]=parseInt(iip.substring(32+i*2,32+i*2+2));
  124:      }
  125:      for (i=0;i<=511;i++) {
  126:         sbarr[i]=parseInt(sb.substring(i*2,i*2+2));
  127:      }
  128:      for (i=0;i<=47;i++) {
  129:         etarr[i]=parseInt(et.substring(i*2,i*2+2));
  130:      }
  131: 
  132:      window.status="Ready.";
  133: }
  134: 
  135: // Return a string with hex-representation of integer
  136: 
  137: function hexstring(i) {
  138:      var hstr="";
  139:      var hchr="0123456789abcdef";
  140:      for (var k=28; k>=0; k=k-4) {
  141:          j=0;
  142:          for (var m=0; m<=3; m++) { if ((i&bit[k+m])!=0) { j=j|bit[m]; } }
  143:          hstr+=hchr.substring(j,j+1);
  144:      }   
  145:      return(hstr);
  146: }
  147: 
  148: // Shift a 28-bit register one time
  149: 
  150: function shift(sreg) {
  151:      var bit27=(sreg&bit[0])<<27;
  152:      return (sreg>>1)|bit27;
  153: }
  154:         
  155: // Initialize key-arrays according to uextkey and lextkey
  156: 
  157: function initkeys() {
  158:      init();
  159: // Constants  
  160:      var celements="574941332517 9 158504234261810 259514335271911 360524436";
  161:      var delements="63554739312315 762544638302214 661534537292113 5282012 4";
  162:      var lkelements="14171124 1 5 32815 62110231912 426 816 7272013 2";
  163:      var ukelements="415231374755304051453348444939563453464250362932";
  164:      var shifttimes="1122222212222221";
  165: // PC-2 order
  166:      var ukarr=new Array(23);
  167:      var lkarr=new Array(23);
  168:      for (i=0;i<=23;i++) {
  169:         ukarr[i]=parseInt(ukelements.substring(i*2,i*2+2));
  170:         lkarr[i]=parseInt(lkelements.substring(i*2,i*2+2));
  171:      }
  172: // Initialize c and d
  173:      var bt;
  174:      var c=0;
  175:      var d=0;
  176:      for (var i=0; i<=27;i++) {
  177:           bt=parseInt(celements.substring(i*2,i*2+2));
  178:           if (bt<=32) {
  179:               if ((uextkey & bit[31-(bt-1)]) != 0) { c=c|bit[i]; }
  180:           } else {
  181:               if ((lextkey & bit[31-(bt-33)]) != 0) { c=c|bit[i]; }
  182:           }
  183:           bt=parseInt(delements.substring(i*2,i*2+2));
  184:           if (bt<=32) {
  185:               if ((uextkey & bit[31-(bt-1)]) != 0) { d=d|bit[i]; }
  186:           } else {
  187:               if ((lextkey & bit[31-(bt-33)]) != 0) { d=d|bit[i]; }
  188:           }
  189:       }
  190: // Initialize the k vectors
  191:       for (i=1;i<=16;i++) {
  192: // Shift c and d
  193:           if (shifttimes.substring(i-1,i)=='1') {
  194:               c=shift(c);
  195:               d=shift(d);
  196:           } else {
  197:               c=shift(shift(c));
  198:               d=shift(shift(d));
  199:           }
  200:           uk[i]=0;
  201:           lk[i]=0;
  202:           for (j=0; j<=23;j++) {            
  203:             if ((d&bit[ukarr[j]-29])!=0) { lk[i]=lk[i]|bit[23-j]; }
  204:             if ((c&bit[lkarr[j]-1])!=0) { uk[i]=uk[i]|bit[23-j]; }
  205:           }
  206:       }
  207: }
  208: 
  209: // Initial permutation of ublock and lblock into rv and lv
  210: 
  211: function ip() {
  212:      var bt;
  213:      rv=0;
  214:      lv=0;
  215:      for (var i=0; i<=31;i++) {
  216:           bt=riparr[i];
  217:           if (bt<=32) {
  218:               if ((lblock & bit[bt-1]) != 0) { rv=rv|bit[i]; }
  219:           } else {
  220:               if ((ublock & bit[bt-33]) != 0) { rv=rv|bit[i]; }
  221:           }
  222:           if (bt<=33) {
  223:               if ((lblock & bit[bt-2]) != 0) { lv=lv|bit[i]; }
  224:           } else {
  225:               if ((ublock & bit[bt-34]) != 0) { lv=lv|bit[i]; }
  226:           }     
  227:      }
  228: }
  229: 
  230: // Inverse Initial Permutation IP-1, input rv,lv, output lblock,ublock
  231: 
  232: function invip() {
  233:      var bt;
  234:      ublock=0;
  235:      lblock=0;
  236:      for (var i=0; i<=15;i++) {
  237:           bt=liiparr[i];
  238:           if ((rv & bit[bt-1]) != 0) { lblock=lblock|bit[i*2]; }
  239:           if ((lv & bit[bt-1]) != 0) { lblock=lblock|bit[i*2+1]; }
  240:           bt=uiiparr[i];
  241:           if ((rv & bit[bt-1]) != 0) { ublock=ublock|bit[i*2]; }
  242:           if ((lv & bit[bt-1]) != 0) { ublock=ublock|bit[i*2+1]; }
  243:      }
  244: }
  245: 
  246: // Expansion of right vector according to E, input rv
  247: 
  248: function expand() {
  249:     var bt;
  250:     uexpand=0;
  251:     lexpand=0;
  252:     for (var i=0; i<=23; i++) {
  253:        bt=etarr[i];
  254:        if (rv & bit[bt-1]) { lexpand=lexpand|bit[i]; } 
  255:     }
  256:     for (i=24; i<=47; i++) {
  257:        bt=etarr[i];
  258:        if (rv & bit[bt-1]) { uexpand=uexpand|bit[i-24]; }
  259:     }
  260: }
  261: 
  262: // Permutes rv according to P, input/output rv
  263: 
  264: function permute() {
  265:     var prv=rv;
  266:     rv=0;
  267:     for (var i=0; i<=31; i++) {
  268:        if ((prv&bit[31-(pparr[i]-1)])!=0) { rv=rv|bit[31-i]; }
  269:     }
  270: }
  271: 
  272: // Performs stage si of the encryption, input/output rv
  273: 
  274: function stage(si) {
  275:     expand();
  276:     var uadd=uexpand^uk[si];
  277:     var ladd=lexpand^lk[si];
  278:     rv=0;
  279:     var ks=0;
  280:     for (var ki=42;ki>=24;ki=ki-6) {
  281:        rv=rv<<4;
  282:        var i=0;
  283:        if ((uadd&bit[ki-24])!=0) { i=i|bit[0]; }
  284:        if ((uadd&bit[ki-19])!=0) { i=i|bit[1]; }
  285:        var j=0;
  286:        for (var kj=0; kj<=3; kj++) {
  287:           if ((uadd&bit[ki-23+kj])!=0) { j=j|bit[kj]; }
  288:        }
  289:        rv=rv|sbarr[ks*64+i*16+j];
  290:        ks++;
  291:     } 
  292:     for (var ki=18;ki>=0;ki=ki-6) {
  293:        rv=rv<<4;
  294:        var i=0;
  295:        if ((ladd&bit[ki]  )!=0) { i=i|bit[0]; }
  296:        if ((ladd&bit[ki+5])!=0) { i=i|bit[1]; }
  297:        var j=0;
  298:        for (var kj=0; kj<=3; kj++) {
  299:           if ((ladd&bit[ki+1+kj])!=0) { j=j|bit[kj]; }
  300:        }
  301:        rv=rv|sbarr[ks*64+i*16+j];
  302:        ks++;
  303:     }
  304:     permute();
  305: }
  306: 
  307: // Encryption
  308: 
  309: function encrypt() {
  310:     ip();
  311:     for (var i=1; i<=16; i++) {
  312:         var prv=rv;
  313:         stage(i);
  314:         rv=rv^lv;
  315:         lv=prv;
  316:     }
  317:     invip();
  318: }
  319: 
  320: // Decryption
  321: 
  322: function decrypt() {
  323:     ip();
  324:     for (var i=16; i>=1; i--) {
  325:         var prv=rv;
  326:         stage(i);
  327:         rv=rv^lv;
  328:         lv=prv;
  329:     }
  330:     invip();
  331: }
  332: 
  333: // Put text into b0,b1,b2,b3
  334:     
  335: function block(text) {;
  336: var equiv= "*+ -./0123456789......@";
  337:     equiv+="ABCDEFGHIJKLMNOPQRSTUVWXYZ    _ ";
  338:     equiv+="abcdefghijklmnopqrstuvwxyz";
  339:     var tl=text.length;
  340:     if (tl>=16) { tl=15; }
  341:     text+="                ";
  342:     text=escape(text);
  343:     var i;
  344:     var c;
  345:     var conv='';
  346:     var j=0;
  347:     for (i=0;i<15;i++) {
  348:         if (text.charAt(j)=='%') {
  349:            conv+=text.charAt(j+1)+text.charAt(j+2);
  350:            j=j+3;
  351:         } else {
  352:            c=hexstring(42+equiv.indexOf(text.charAt(j)));
  353:            conv+=c.substr(6,2);
  354:            j++;
  355:         }
  356:     }
  357:     b3=tl*bit[24]+parseInt("0x"+conv.substr(0,6));
  358:     b2=parseInt("0x"+conv.substr(6,8));
  359:     b1=parseInt("0x"+conv.substr(14,8));
  360:     b0=parseInt("0x"+conv.substr(22,8));
  361: 
  362: }
  363: 
  364: function crypted(text) {
  365:     block(text);
  366:     lblock=b0;
  367:     ublock=b1;
  368:     encrypt();
  369:     b0=lblock;
  370:     b1=ublock;
  371:     lblock=b2;
  372:     ublock=b3;
  373:     encrypt();
  374:     b2=lblock;
  375:     b3=ublock;
  376:     return(hexstring(b3)+hexstring(b2)+hexstring(b1)+hexstring(b0));
  377: }
  378: 
  379: // ]]>
  380: </script>