1: <script language="JavaScript">
2: // The LearningOnline Network with CAPA
3: // Encryption Routines according to Data Encryption Standard DES
4: // Federal Information Processing Standards Publication 46-2 (1993 Dec 30)
5: //
6: // $Id: londes.js,v 1.2 2001/11/29 19:12:44 www Exp $
7: //
8: // Copyright Michigan State University Board of Trustees
9: //
10: // This file is part of the LearningOnline Network with CAPA (LON-CAPA).
11: //
12: // LON-CAPA is free software; you can redistribute it and/or modify
13: // it under the terms of the GNU General Public License as published by
14: // the Free Software Foundation; either version 2 of the License, or
15: // (at your option) any later version.
16: //
17: // LON-CAPA is distributed in the hope that it will be useful,
18: // but WITHOUT ANY WARRANTY; without even the implied warranty of
19: // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
20: // GNU General Public License for more details.
21: //
22: // You should have received a copy of the GNU General Public License
23: // along with LON-CAPA; if not, write to the Free Software
24: // Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
25: //
26: // /home/httpd/html/adm/gpl.txt
27: //
28: // http://www.lon-capa.org/
29: //
30: // JavaScript Implementation by Gerd Kortemeyer
31: // 1997,06/27/00,06/28 Gerd Kortemeyer
32:
33: // Global variables
34:
35: // Array of integers with i-th bit set
36: var bit=new Array(31);
37: // Initial permutation IP for right part
38: var riparr=new Array(31);
39: // Inverse permutation IP-1
40: var liiparr=new Array(31);
41: var uiiparr=new Array(31);
42: // Key vectors
43: var uk=new Array(16);
44: var lk=new Array(16);
45: // Upper- and lower 32-bit of external key
46: var uextkey=0;
47: var lextkey=0;
48: // Upper- and lower 32-bit of block
49: var ublock=0;
50: var lblock=0;
51: // Upper and lower 24 bit of expanded right vector
52: var lexpand=0;
53: var uexpand=0;
54: // S-box array
55: var sbarr=new Array(511);
56: // E expansion
57: var etarr=new Array(47);
58: // P permutation
59: var pparr=new Array(31);
60: // r- and l-vector
61: var rv=0;
62: var lv=0;
63: // Blocks of data for text
64: var b0=0;
65: var b1=0;
66: var b2=0;
67: var b3=0;
68: // Text variable
69: var text="";
70:
71: // Initialize table arrays and perform self test
72:
73: function init() {
74: window.status="Initializing ...";
75: var rip="58504234261810 260524436282012 462544638302214 664564840322416 8";
76: var iip=" 8162432 7152331 6142230 5132129 4122028 3111927 2101826 1 91725";
77: var sb
78: sb ="14 413 1 21511 8 310 612 5 9 0 7";
79: sb+=" 015 7 414 213 110 61211 9 5 3 8";
80: sb+=" 4 114 813 6 2111512 9 7 310 5 0";
81: sb+="1512 8 2 4 9 1 7 511 31410 0 613";
82: sb+="15 1 814 611 3 4 9 7 21312 0 510";
83: sb+=" 313 4 715 2 81412 0 110 6 911 5";
84: sb+=" 014 71110 413 1 5 812 6 9 3 215";
85: sb+="13 810 1 315 4 211 6 712 0 514 9";
86: sb+="10 0 914 6 315 5 11312 711 4 2 8";
87: sb+="13 7 0 9 3 4 610 2 8 514121115 1";
88: sb+="13 6 4 9 815 3 011 1 212 51014 7";
89: sb+=" 11013 0 6 9 8 7 41514 311 5 212";
90: sb+=" 71314 3 0 6 910 1 2 8 51112 415";
91: sb+="13 811 5 615 0 3 4 7 212 11014 9";
92: sb+="10 6 9 01211 71315 1 314 5 2 8 4";
93: sb+=" 315 0 610 113 8 9 4 51112 7 214";
94: sb+=" 212 4 1 71011 6 8 5 31513 014 9";
95: sb+="1411 212 4 713 1 5 01510 3 9 8 6";
96: sb+=" 4 2 1111013 7 815 912 5 6 3 014";
97: sb+="11 812 7 114 213 615 0 910 4 5 3";
98: sb+="12 11015 9 2 6 8 013 3 414 7 511";
99: sb+="1015 4 2 712 9 5 6 11314 011 3 8";
100: sb+=" 91415 5 2 812 3 7 0 410 11311 6";
101: sb+=" 4 3 212 9 515101114 1 7 6 0 813";
102: sb+=" 411 21415 0 813 312 9 7 510 6 1";
103: sb+="13 011 7 4 9 11014 3 512 215 8 6";
104: sb+=" 1 4111312 3 7141015 6 8 0 5 9 2";
105: sb+=" 61113 8 1 410 7 9 5 01514 2 312";
106: sb+="13 2 8 4 61511 110 9 314 5 012 7";
107: sb+=" 11513 810 3 7 412 5 611 014 9 2";
108: sb+=" 711 4 1 91214 2 0 6101315 3 5 8";
109: sb+=" 2 114 7 410 8131512 9 0 3 5 611";
110: var et
111: et ="32 1 2 3 4 5 4 5 6 7 8 9 8 910111213121314151617";
112: et+="1617181920212021222324252425262728292829303132 1";
113: var pp="16 7202129122817 1152326 5183110 2 824143227 3 9191330 62211 425";
114: bit[0]=1;
115: for (var i=1; i<=31;i++) { bit[i]=bit[i-1]<<1; }
116: for (i=0; i<=31;i++) {
117: riparr[i]=parseInt(rip.substring(i*2,i*2+2));
118: pparr[i]=parseInt(pp.substring(i*2,i*2+2));
119: }
120: for (i=0;i<=15;i++) {
121: liiparr[i]=parseInt(iip.substring(i*2,i*2+2));
122: uiiparr[i]=parseInt(iip.substring(32+i*2,32+i*2+2));
123: }
124: for (i=0;i<=511;i++) {
125: sbarr[i]=parseInt(sb.substring(i*2,i*2+2));
126: }
127: for (i=0;i<=47;i++) {
128: etarr[i]=parseInt(et.substring(i*2,i*2+2));
129: }
130:
131: window.status="Ready.";
132: }
133:
134: // Return a string with hex-representation of integer
135:
136: function hexstring(i) {
137: var hstr="";
138: var hchr="0123456789abcdef";
139: for (var k=28; k>=0; k=k-4) {
140: j=0;
141: for (var m=0; m<=3; m++) { if ((i&bit[k+m])!=0) { j=j|bit[m]; } }
142: hstr+=hchr.substring(j,j+1);
143: }
144: return(hstr);
145: }
146:
147: // Shift a 28-bit register one time
148:
149: function shift(sreg) {
150: var bit27=(sreg&bit[0])<<27;
151: return (sreg>>1)|bit27;
152: }
153:
154: // Initialize key-arrays according to uextkey and lextkey
155:
156: function initkeys() {
157: // Constants
158: var celements="574941332517 9 158504234261810 259514335271911 360524436";
159: var delements="63554739312315 762544638302214 661534537292113 5282012 4";
160: var lkelements="14171124 1 5 32815 62110231912 426 816 7272013 2";
161: var ukelements="415231374755304051453348444939563453464250362932";
162: var shifttimes="1122222212222221";
163: // PC-2 order
164: var ukarr=new Array(23);
165: var lkarr=new Array(23);
166: for (i=0;i<=23;i++) {
167: ukarr[i]=parseInt(ukelements.substring(i*2,i*2+2));
168: lkarr[i]=parseInt(lkelements.substring(i*2,i*2+2));
169: }
170: // Initialize c and d
171: var bt;
172: var c=0;
173: var d=0;
174: for (var i=0; i<=27;i++) {
175: bt=parseInt(celements.substring(i*2,i*2+2));
176: if (bt<=32) {
177: if ((uextkey & bit[31-(bt-1)]) != 0) { c=c|bit[i]; }
178: } else {
179: if ((lextkey & bit[31-(bt-33)]) != 0) { c=c|bit[i]; }
180: }
181: bt=parseInt(delements.substring(i*2,i*2+2));
182: if (bt<=32) {
183: if ((uextkey & bit[31-(bt-1)]) != 0) { d=d|bit[i]; }
184: } else {
185: if ((lextkey & bit[31-(bt-33)]) != 0) { d=d|bit[i]; }
186: }
187: }
188: // Initialize the k vectors
189: for (i=1;i<=16;i++) {
190: // Shift c and d
191: if (shifttimes.substring(i-1,i)=='1') {
192: c=shift(c);
193: d=shift(d);
194: } else {
195: c=shift(shift(c));
196: d=shift(shift(d));
197: }
198: uk[i]=0;
199: lk[i]=0;
200: for (j=0; j<=23;j++) {
201: if ((d&bit[ukarr[j]-29])!=0) { lk[i]=lk[i]|bit[23-j]; }
202: if ((c&bit[lkarr[j]-1])!=0) { uk[i]=uk[i]|bit[23-j]; }
203: }
204: }
205: }
206:
207: // Initial permutation of ublock and lblock into rv and lv
208:
209: function ip() {
210: var bt;
211: rv=0;
212: lv=0;
213: for (var i=0; i<=31;i++) {
214: bt=riparr[i];
215: if (bt<=32) {
216: if ((lblock & bit[bt-1]) != 0) { rv=rv|bit[i]; }
217: } else {
218: if ((ublock & bit[bt-33]) != 0) { rv=rv|bit[i]; }
219: }
220: if (bt<=33) {
221: if ((lblock & bit[bt-2]) != 0) { lv=lv|bit[i]; }
222: } else {
223: if ((ublock & bit[bt-34]) != 0) { lv=lv|bit[i]; }
224: }
225: }
226: }
227:
228: // Inverse Initial Permutation IP-1, input rv,lv, output lblock,ublock
229:
230: function invip() {
231: var bt;
232: ublock=0;
233: lblock=0;
234: for (var i=0; i<=15;i++) {
235: bt=liiparr[i];
236: if ((rv & bit[bt-1]) != 0) { lblock=lblock|bit[i*2]; }
237: if ((lv & bit[bt-1]) != 0) { lblock=lblock|bit[i*2+1]; }
238: bt=uiiparr[i];
239: if ((rv & bit[bt-1]) != 0) { ublock=ublock|bit[i*2]; }
240: if ((lv & bit[bt-1]) != 0) { ublock=ublock|bit[i*2+1]; }
241: }
242: }
243:
244: // Expansion of right vector according to E, input rv
245:
246: function expand() {
247: var bt;
248: uexpand=0;
249: lexpand=0;
250: for (var i=0; i<=23; i++) {
251: bt=etarr[i];
252: if (rv & bit[bt-1]) { lexpand=lexpand|bit[i]; }
253: }
254: for (i=24; i<=47; i++) {
255: bt=etarr[i];
256: if (rv & bit[bt-1]) { uexpand=uexpand|bit[i-24]; }
257: }
258: }
259:
260: // Permutes rv according to P, input/output rv
261:
262: function permute() {
263: var prv=rv;
264: rv=0;
265: for (var i=0; i<=31; i++) {
266: if ((prv&bit[31-(pparr[i]-1)])!=0) { rv=rv|bit[31-i]; }
267: }
268: }
269:
270: // Performs stage si of the encryption, input/output rv
271:
272: function stage(si) {
273: expand();
274: var uadd=uexpand^uk[si];
275: var ladd=lexpand^lk[si];
276: rv=0;
277: var ks=0;
278: for (var ki=42;ki>=24;ki=ki-6) {
279: rv=rv<<4;
280: var i=0;
281: if ((uadd&bit[ki-24])!=0) { i=i|bit[0]; }
282: if ((uadd&bit[ki-19])!=0) { i=i|bit[1]; }
283: var j=0;
284: for (var kj=0; kj<=3; kj++) {
285: if ((uadd&bit[ki-23+kj])!=0) { j=j|bit[kj]; }
286: }
287: rv=rv|sbarr[ks*64+i*16+j];
288: ks++;
289: }
290: for (var ki=18;ki>=0;ki=ki-6) {
291: rv=rv<<4;
292: var i=0;
293: if ((ladd&bit[ki] )!=0) { i=i|bit[0]; }
294: if ((ladd&bit[ki+5])!=0) { i=i|bit[1]; }
295: var j=0;
296: for (var kj=0; kj<=3; kj++) {
297: if ((ladd&bit[ki+1+kj])!=0) { j=j|bit[kj]; }
298: }
299: rv=rv|sbarr[ks*64+i*16+j];
300: ks++;
301: }
302: permute();
303: }
304:
305: // Encryption
306:
307: function encrypt() {
308: ip();
309: for (var i=1; i<=16; i++) {
310: var prv=rv;
311: stage(i);
312: rv=rv^lv;
313: lv=prv;
314: }
315: invip();
316: }
317:
318: // Decryption
319:
320: function decrypt() {
321: ip();
322: for (var i=16; i>=1; i--) {
323: var prv=rv;
324: stage(i);
325: rv=rv^lv;
326: lv=prv;
327: }
328: invip();
329: }
330:
331: // Put text into b0,b1,b2,b3
332:
333: function block(text) {;
334: var equiv= "*+ -./0123456789......@";
335: equiv+="ABCDEFGHIJKLMNOPQRSTUVWXYZ _ ";
336: equiv+="abcdefghijklmnopqrstuvwxyz";
337: var tl=text.length;
338: if (tl>=16) { tl=15; }
339: text+=" ";
340: text=escape(text);
341: var i;
342: var c;
343: var conv='';
344: var j=0;
345: for (i=0;i<15;i++) {
346: if (text.charAt(j)=='%') {
347: conv+=text.charAt(j+1)+text.charAt(j+2);
348: j=j+3;
349: } else {
350: c=hexstring(42+equiv.indexOf(text.charAt(j)));
351: conv+=c.substr(6,2);
352: j++;
353: }
354: }
355: b3=tl*bit[24]+parseInt("0x"+conv.substr(0,6));
356: b2=parseInt("0x"+conv.substr(6,8));
357: b1=parseInt("0x"+conv.substr(14,8));
358: b0=parseInt("0x"+conv.substr(22,8));
359:
360: }
361:
362: function crypted(text) {
363: block(text);
364: lblock=b0;
365: ublock=b1;
366: encrypt();
367: b0=lblock;
368: b1=ublock;
369: lblock=b2;
370: ublock=b3;
371: encrypt();
372: b2=lblock;
373: b3=ublock;
374: return(hexstring(b3)+hexstring(b2)+hexstring(b1)+hexstring(b0));
375: }
376:
377: </script>
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