Annotation of loncom/auth/londes.js, revision 1.3
1.1 www 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)
1.2 www 5: //
1.3 ! www 6: // $Id: londes.js,v 1.2 2001/11/29 19:12:44 www Exp $
1.2 www 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: //
1.1 www 30: // JavaScript Implementation by Gerd Kortemeyer
1.3 ! www 31: // 1997,06/27/00,06/28,03/23/02 Gerd Kortemeyer
1.1 www 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:
1.3 ! www 71:
! 72: // Function to AND with bit i
! 73:
! 74: function andbit(value,i) {
! 75: return value&bit[i];
! 76: }
! 77:
! 78: // Function to OR with bit i
! 79:
! 80: function orbit(value,i) {
! 81: return value|bit[i];
! 82: }
! 83:
1.1 www 84: // Initialize table arrays and perform self test
85:
86: function init() {
87: window.status="Initializing ...";
88: var rip="58504234261810 260524436282012 462544638302214 664564840322416 8";
89: var iip=" 8162432 7152331 6142230 5132129 4122028 3111927 2101826 1 91725";
90: var sb
91: sb ="14 413 1 21511 8 310 612 5 9 0 7";
92: sb+=" 015 7 414 213 110 61211 9 5 3 8";
93: sb+=" 4 114 813 6 2111512 9 7 310 5 0";
94: sb+="1512 8 2 4 9 1 7 511 31410 0 613";
95: sb+="15 1 814 611 3 4 9 7 21312 0 510";
96: sb+=" 313 4 715 2 81412 0 110 6 911 5";
97: sb+=" 014 71110 413 1 5 812 6 9 3 215";
98: sb+="13 810 1 315 4 211 6 712 0 514 9";
99: sb+="10 0 914 6 315 5 11312 711 4 2 8";
100: sb+="13 7 0 9 3 4 610 2 8 514121115 1";
101: sb+="13 6 4 9 815 3 011 1 212 51014 7";
102: sb+=" 11013 0 6 9 8 7 41514 311 5 212";
103: sb+=" 71314 3 0 6 910 1 2 8 51112 415";
104: sb+="13 811 5 615 0 3 4 7 212 11014 9";
105: sb+="10 6 9 01211 71315 1 314 5 2 8 4";
106: sb+=" 315 0 610 113 8 9 4 51112 7 214";
107: sb+=" 212 4 1 71011 6 8 5 31513 014 9";
108: sb+="1411 212 4 713 1 5 01510 3 9 8 6";
109: sb+=" 4 2 1111013 7 815 912 5 6 3 014";
110: sb+="11 812 7 114 213 615 0 910 4 5 3";
111: sb+="12 11015 9 2 6 8 013 3 414 7 511";
112: sb+="1015 4 2 712 9 5 6 11314 011 3 8";
113: sb+=" 91415 5 2 812 3 7 0 410 11311 6";
114: sb+=" 4 3 212 9 515101114 1 7 6 0 813";
115: sb+=" 411 21415 0 813 312 9 7 510 6 1";
116: sb+="13 011 7 4 9 11014 3 512 215 8 6";
117: sb+=" 1 4111312 3 7141015 6 8 0 5 9 2";
118: sb+=" 61113 8 1 410 7 9 5 01514 2 312";
119: sb+="13 2 8 4 61511 110 9 314 5 012 7";
120: sb+=" 11513 810 3 7 412 5 611 014 9 2";
121: sb+=" 711 4 1 91214 2 0 6101315 3 5 8";
122: sb+=" 2 114 7 410 8131512 9 0 3 5 611";
123: var et
124: et ="32 1 2 3 4 5 4 5 6 7 8 9 8 910111213121314151617";
125: et+="1617181920212021222324252425262728292829303132 1";
126: var pp="16 7202129122817 1152326 5183110 2 824143227 3 9191330 62211 425";
127: bit[0]=1;
128: for (var i=1; i<=31;i++) { bit[i]=bit[i-1]<<1; }
129: for (i=0; i<=31;i++) {
130: riparr[i]=parseInt(rip.substring(i*2,i*2+2));
131: pparr[i]=parseInt(pp.substring(i*2,i*2+2));
132: }
133: for (i=0;i<=15;i++) {
134: liiparr[i]=parseInt(iip.substring(i*2,i*2+2));
135: uiiparr[i]=parseInt(iip.substring(32+i*2,32+i*2+2));
136: }
137: for (i=0;i<=511;i++) {
138: sbarr[i]=parseInt(sb.substring(i*2,i*2+2));
139: }
140: for (i=0;i<=47;i++) {
141: etarr[i]=parseInt(et.substring(i*2,i*2+2));
142: }
143:
144: window.status="Ready.";
145: }
146:
147: // Return a string with hex-representation of integer
148:
149: function hexstring(i) {
150: var hstr="";
151: var hchr="0123456789abcdef";
152: for (var k=28; k>=0; k=k-4) {
153: j=0;
1.3 ! www 154: for (var m=0; m<=3; m++) { if (andbit(i,k+m)!=0) { j=orbit(j,m); } }
1.1 www 155: hstr+=hchr.substring(j,j+1);
156: }
157: return(hstr);
158: }
159:
160: // Shift a 28-bit register one time
161:
162: function shift(sreg) {
1.3 ! www 163: var bit27=andbit(sreg,0)<<27;
1.1 www 164: return (sreg>>1)|bit27;
165: }
166:
167: // Initialize key-arrays according to uextkey and lextkey
168:
169: function initkeys() {
170: // Constants
171: var celements="574941332517 9 158504234261810 259514335271911 360524436";
172: var delements="63554739312315 762544638302214 661534537292113 5282012 4";
173: var lkelements="14171124 1 5 32815 62110231912 426 816 7272013 2";
174: var ukelements="415231374755304051453348444939563453464250362932";
175: var shifttimes="1122222212222221";
176: // PC-2 order
177: var ukarr=new Array(23);
178: var lkarr=new Array(23);
179: for (i=0;i<=23;i++) {
180: ukarr[i]=parseInt(ukelements.substring(i*2,i*2+2));
181: lkarr[i]=parseInt(lkelements.substring(i*2,i*2+2));
182: }
183: // Initialize c and d
184: var bt;
185: var c=0;
186: var d=0;
187: for (var i=0; i<=27;i++) {
188: bt=parseInt(celements.substring(i*2,i*2+2));
189: if (bt<=32) {
1.3 ! www 190: if (andbit(uextkey,31-(bt-1)) != 0) { c=orbit(c,i); }
1.1 www 191: } else {
1.3 ! www 192: if (andbit(lextkey,31-(bt-33)) != 0) { c=orbit(c,i); }
1.1 www 193: }
194: bt=parseInt(delements.substring(i*2,i*2+2));
195: if (bt<=32) {
1.3 ! www 196: if (andbit(uextkey,31-(bt-1)) != 0) { d=orbit(d,i); }
1.1 www 197: } else {
1.3 ! www 198: if (andbit(lextkey,31-(bt-33)) != 0) { d=orbit(d,i); }
1.1 www 199: }
200: }
201: // Initialize the k vectors
202: for (i=1;i<=16;i++) {
203: // Shift c and d
204: if (shifttimes.substring(i-1,i)=='1') {
205: c=shift(c);
206: d=shift(d);
207: } else {
208: c=shift(shift(c));
209: d=shift(shift(d));
210: }
211: uk[i]=0;
212: lk[i]=0;
213: for (j=0; j<=23;j++) {
1.3 ! www 214: if (andbit(d,ukarr[j]-29)!=0) { lk[i]=orbit(lk[i],23-j); }
! 215: if (andbit(c,lkarr[j]-1)!=0) { uk[i]=orbit(uk[i],23-j); }
1.1 www 216: }
217: }
218: }
219:
220: // Initial permutation of ublock and lblock into rv and lv
221:
222: function ip() {
223: var bt;
224: rv=0;
225: lv=0;
226: for (var i=0; i<=31;i++) {
227: bt=riparr[i];
228: if (bt<=32) {
1.3 ! www 229: if (andbit(lblock,bt-1) != 0) { rv=orbit(rv,i); }
1.1 www 230: } else {
1.3 ! www 231: if (andbit(ublock,bt-33) != 0) { rv=orbit(rv,i); }
1.1 www 232: }
233: if (bt<=33) {
1.3 ! www 234: if (andbit(lblock,bt-2) != 0) { lv=orbit(lv,i); }
1.1 www 235: } else {
1.3 ! www 236: if (andbit(ublock,bt-34) != 0) { lv=orbit(lv,i); }
1.1 www 237: }
238: }
239: }
240:
241: // Inverse Initial Permutation IP-1, input rv,lv, output lblock,ublock
242:
243: function invip() {
244: var bt;
245: ublock=0;
246: lblock=0;
247: for (var i=0; i<=15;i++) {
248: bt=liiparr[i];
1.3 ! www 249: if (andbit(rv,bt-1) != 0) { lblock=orbit(lblock,i*2); }
! 250: if (andbit(lv,bt-1) != 0) { lblock=orbit(lblock,i*2+1); }
1.1 www 251: bt=uiiparr[i];
1.3 ! www 252: if (andbit(rv,bt-1) != 0) { ublock=orbit(ublock,i*2); }
! 253: if (andbit(lv,bt-1) != 0) { ublock=orbit(ublock,i*2+1); }
1.1 www 254: }
255: }
256:
257: // Expansion of right vector according to E, input rv
258:
259: function expand() {
260: var bt;
261: uexpand=0;
262: lexpand=0;
263: for (var i=0; i<=23; i++) {
264: bt=etarr[i];
1.3 ! www 265: if (andbit(rv,bt-1)!=0) { lexpand=orbit(lexpand,i); }
1.1 www 266: }
267: for (i=24; i<=47; i++) {
268: bt=etarr[i];
1.3 ! www 269: if (andbit(rv,bt-1)!=0) { uexpand=orbit(uexpand,i-24); }
1.1 www 270: }
271: }
272:
273: // Permutes rv according to P, input/output rv
274:
275: function permute() {
276: var prv=rv;
277: rv=0;
278: for (var i=0; i<=31; i++) {
1.3 ! www 279: if (andbit(prv,31-(pparr[i]-1))!=0) { rv=orbit(rv,31-i); }
1.1 www 280: }
281: }
282:
283: // Performs stage si of the encryption, input/output rv
284:
285: function stage(si) {
286: expand();
287: var uadd=uexpand^uk[si];
288: var ladd=lexpand^lk[si];
289: rv=0;
290: var ks=0;
291: for (var ki=42;ki>=24;ki=ki-6) {
292: rv=rv<<4;
293: var i=0;
1.3 ! www 294: if (andbit(uadd,ki-24)!=0) { i=orbit(i,0); }
! 295: if (andbit(uadd,ki-19)!=0) { i=orbit(i,1); }
1.1 www 296: var j=0;
297: for (var kj=0; kj<=3; kj++) {
1.3 ! www 298: if (andbit(uadd,ki-23+kj)!=0) { j=orbit(j,kj); }
1.1 www 299: }
300: rv=rv|sbarr[ks*64+i*16+j];
301: ks++;
302: }
303: for (var ki=18;ki>=0;ki=ki-6) {
304: rv=rv<<4;
305: var i=0;
1.3 ! www 306: if (andbit(ladd,ki) !=0) { i=orbit(i,0); }
! 307: if (andbit(ladd,ki+5)!=0) { i=orbit(i,1); }
1.1 www 308: var j=0;
309: for (var kj=0; kj<=3; kj++) {
1.3 ! www 310: if (andbit(ladd,ki+1+kj)!=0) { j=orbit(j,kj); }
1.1 www 311: }
312: rv=rv|sbarr[ks*64+i*16+j];
313: ks++;
314: }
315: permute();
316: }
317:
318: // Encryption
319:
320: function encrypt() {
321: ip();
322: for (var i=1; i<=16; i++) {
323: var prv=rv;
324: stage(i);
325: rv=rv^lv;
326: lv=prv;
327: }
328: invip();
329: }
330:
331: // Decryption
332:
333: function decrypt() {
334: ip();
335: for (var i=16; i>=1; i--) {
336: var prv=rv;
337: stage(i);
338: rv=rv^lv;
339: lv=prv;
340: }
341: invip();
342: }
343:
344: // Put text into b0,b1,b2,b3
345:
346: function block(text) {;
347: var equiv= "*+ -./0123456789......@";
348: equiv+="ABCDEFGHIJKLMNOPQRSTUVWXYZ _ ";
349: equiv+="abcdefghijklmnopqrstuvwxyz";
350: var tl=text.length;
351: if (tl>=16) { tl=15; }
352: text+=" ";
353: text=escape(text);
354: var i;
355: var c;
356: var conv='';
357: var j=0;
358: for (i=0;i<15;i++) {
359: if (text.charAt(j)=='%') {
360: conv+=text.charAt(j+1)+text.charAt(j+2);
361: j=j+3;
362: } else {
363: c=hexstring(42+equiv.indexOf(text.charAt(j)));
364: conv+=c.substr(6,2);
365: j++;
366: }
367: }
368: b3=tl*bit[24]+parseInt("0x"+conv.substr(0,6));
369: b2=parseInt("0x"+conv.substr(6,8));
370: b1=parseInt("0x"+conv.substr(14,8));
371: b0=parseInt("0x"+conv.substr(22,8));
372:
373: }
374:
375: function crypted(text) {
376: block(text);
377: lblock=b0;
378: ublock=b1;
379: encrypt();
380: b0=lblock;
381: b1=ublock;
382: lblock=b2;
383: ublock=b3;
384: encrypt();
385: b2=lblock;
386: b3=ublock;
387: return(hexstring(b3)+hexstring(b2)+hexstring(b1)+hexstring(b0));
388: }
389:
390: </script>
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