mdw@git.distorted.org.uk Git - tripe/blob - mallory.c

   1 /* -*-c-*-
   2  *
   3  * $Id: mallory.c,v 1.2 2003/10/15 09:31:06 mdw Exp $
   4  *
   5  * An evil proxy for TrIPE
   6  *
   7  * (c) 2001 Straylight/Edgeware
   8  */
   9
  10 /*----- Licensing notice --------------------------------------------------*
  11  *
  12  * This file is part of Trivial IP Encryption (TrIPE).
  13  *
  14  * TrIPE is free software; you can redistribute it and/or modify
  15  * it under the terms of the GNU General Public License as published by
  16  * the Free Software Foundation; either version 2 of the License, or
  17  * (at your option) any later version.
  18  *
  19  * TrIPE is distributed in the hope that it will be useful,
  20  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  21  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  * GNU General Public License for more details.
  23  *
  24  * You should have received a copy of the GNU General Public License
  25  * along with TrIPE; if not, write to the Free Software Foundation,
  26  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  27  */
  28
  29 /*----- Revision history --------------------------------------------------*
  30  *
  31  * $Log: mallory.c,v $
  32  * Revision 1.2  2003/10/15 09:31:06  mdw
  33  * Make forking work properly.
  34  *
  35  * Revision 1.1  2001/06/19 22:11:14  mdw
  36  * The beginnings of a malicious proxy for TrIPE.
  37  *
  38  */
  39
  40 /*----- Header files ------------------------------------------------------*/
  41
  42 #include "config.h"
  43
  44 #include <assert.h>
  45 #include <errno.h>
  46 #include <stdio.h>
  47 #include <stdlib.h>
  48 #include <string.h>
  49 #include <time.h>
  50
  51 #include <sys/types.h>
  52 #include <sys/time.h>
  53 #include <unistd.h>
  54 #include <fcntl.h>
  55
  56 #include <sys/socket.h>
  57 #include <netinet/in.h>
  58 #include <arpa/inet.h>
  59 #include <netdb.h>
  60
  61 #include <mLib/alloc.h>
  62 #include <mLib/dstr.h>
  63 #include <mLib/fdflags.h>
  64 #include <mLib/mdwopt.h>
  65 #include <mLib/quis.h>
  66 #include <mLib/report.h>
  67 #include <mLib/sel.h>
  68 #include <mLib/sub.h>
  69 #include <mLib/tv.h>
  70
  71 #include <catacomb/buf.h>
  72
  73 #include <catacomb/key.h>
  74
  75 #include <catacomb/mp.h>
  76 #include <catacomb/mpmont.h>
  77 #include <catacomb/mprand.h>
  78 #include <catacomb/dh.h>
  79
  80 #include <catacomb/noise.h>
  81 #include <catacomb/rand.h>
  82 #include <catacomb/rc4.h>
  83
  84
  85 /*----- Data structures ---------------------------------------------------*/
  86
  87 typedef struct peer {
  88   sel_file sf;
  89   dh_pub kpub;
  90   const char *name;
  91   struct filter *f;
  92 } peer;
  93
  94 typedef struct filter {
  95   struct filter *next;
  96   peer *p_from, *p_to;
  97   void (*func)(struct filter */*f*/, const octet */*buf*/, size_t /*sz*/);
  98   void *state;
  99 } filter;
 100
 101 typedef struct qnode {
 102   octet *buf;
 103   size_t sz;
 104 } qnode;
 105
 106 /*----- Static variables --------------------------------------------------*/
 107
 108 #define PKBUFSZ 65536
 109
 110 static sel_state sel;
 111 static peer peers[2];
 112 static unsigned npeer = 0;
 113 static key_file keys;
 114 static grand *rng;
 115
 116 #define PASS(f, buf, sz) ((f) ? (f)->func((f), (buf), (sz)) : (void)0)
 117 #define RND(i) (rng->ops->range(rng, (i)))
 118
 119 /*----- Peer management ---------------------------------------------------*/
 120
 121 static void dopacket(int fd, unsigned mode, void *vv)
 122 {
 123   octet buf[PKBUFSZ];
 124   peer *p = vv;
 125   int r = read(fd, buf, sizeof(buf));
 126   if (r >= 0) {
 127     printf("recv from `%s'\n", p->name);
 128     PASS(p->f, buf, r);
 129   }
 130 }
 131
 132 static void addpeer(unsigned ac, char **av)
 133 {
 134   key_packstruct kps[DH_PUBFETCHSZ];
 135   key_packdef *kp;
 136   struct hostent *h;
 137   struct sockaddr_in sin;
 138   int len = PKBUFSZ;
 139   peer *p;
 140   int fd;
 141   int e;
 142
 143   if (ac != 4)
 144     die(1, "syntax: peer:NAME:PORT:ADDR:PORT");
 145   if (npeer >= 2)
 146     die(1, "enough peers already");
 147   p = &peers[npeer++];
 148   p->name = xstrdup(av[0]);
 149   kp = key_fetchinit(dh_pubfetch, kps, &p->kpub);
 150   e = key_fetchbyname(kp, &keys, av[0]);
 151   key_fetchdone(kp);
 152   if (e)
 153     die(1, "key_fetch `%s': %s", av[0], key_strerror(e));
 154   if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
 155     die(1, "socket: %s", strerror(errno));
 156   fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
 157   memset(&sin, 0, sizeof(sin));
 158   sin.sin_family = AF_INET;
 159   sin.sin_addr.s_addr = INADDR_ANY;
 160   sin.sin_port = htons(atoi(av[1]));
 161   if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)))
 162     die(1, "bind: %s", strerror(errno));
 163   memset(&sin, 0, sizeof(sin));
 164   sin.sin_family = AF_INET;
 165   if ((h = gethostbyname(av[2])) == 0)
 166     die(1, "gethostbyname `%s'", av[2]);
 167   if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
 168       setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len)))
 169     die(1, "setsockopt: %s", strerror(errno));
 170   memcpy(&sin.sin_addr, h->h_addr, sizeof(sin.sin_addr));
 171   sin.sin_port = htons(atoi(av[3]));
 172   if (connect(fd, (struct sockaddr *)&sin, sizeof(sin)))
 173     die(1, "connect: %s", strerror(errno));
 174   sel_initfile(&sel, &p->sf, fd, SEL_READ, dopacket, p);
 175   sel_addfile(&p->sf);
 176 }
 177
 178 /*----- Fork filter -------------------------------------------------------*/
 179
 180 typedef struct forknode {
 181   struct forknode *next;
 182   filter *f;
 183 } forknode;
 184
 185 typedef struct forkfilt {
 186   const char *name;
 187   forknode *fn;
 188 } forkfilt;
 189
 190 static void dofork(filter *f, const octet *buf, size_t sz)
 191 {
 192   forkfilt *ff = f->state;
 193   forknode *fn;
 194   unsigned i = 0;
 195
 196   ff = f->state;
 197   for (fn = ff->fn; fn; fn = fn->next) {
 198     printf("fork branch %u of fork `%s'\n", i++, ff->name);
 199     PASS(fn->f, buf, sz);
 200   }
 201   printf("fork branch %u of fork `%s'\n", i++, ff->name);
 202   PASS(f->next, buf, sz);
 203 }
 204
 205 static void addfork(filter *f, unsigned ac, char **av)
 206 {
 207   forkfilt *ff;
 208   if (ac != 1)
 209     die(1, "syntax: filt:fork:NAME");
 210   ff = CREATE(forkfilt);
 211   ff->name = xstrdup(av[0]);
 212   ff->fn = 0;
 213   f->func = dofork;
 214   f->state = ff;
 215 }
 216
 217 static void nextfork(unsigned ac, char **av)
 218 {
 219   unsigned i, j;
 220   filter *f;
 221   forkfilt *ff;
 222   forknode *fn, **ffn;
 223   peer *p;
 224
 225   if (ac < 1)
 226     die(1, "syntax: next:NAME:...");
 227   for (i = 0; i < 2; i++) {
 228     p = &peers[i];
 229     for (f = p->f; f; f = f->next) {
 230       if (f->func != dofork)
 231         continue;
 232       ff = f->state;
 233       for (j = 0; j < ac; j++) {
 234         if (strcmp(av[j], ff->name) == 0)
 235           goto match;
 236       }
 237       continue;
 238     match:
 239       fn = CREATE(forknode);
 240       for (ffn = &ff->fn; *ffn; ffn = &(*ffn)->next)
 241         ;
 242       fn->f = f->next;
 243       f->next = 0;
 244       fn->next = 0;
 245       *ffn = fn;
 246     }
 247   }
 248 }
 249
 250 /*----- Corrupt filter ----------------------------------------------------*/
 251
 252 typedef struct corrupt {
 253   unsigned p_corrupt;
 254 } corrupt;
 255
 256 static void docorrupt(filter *f, const octet *buf, size_t sz)
 257 {
 258   corrupt *c = f->state;
 259   octet b[PKBUFSZ];
 260   memcpy(b, buf, sz);
 261
 262   while (!RND(c->p_corrupt)) {
 263     puts("corrupt packet");
 264     b[RND(sz)] ^= RND(256);
 265   }
 266   PASS(f->next, b, sz);
 267 }
 268
 269 static void addcorrupt(filter *f, unsigned ac, char **av)
 270 {
 271   corrupt *c;
 272   if (ac > 1)
 273     die(1, "syntax: filt:corrupt[:PCORRUPT]");
 274   c = CREATE(corrupt);
 275   if (ac > 0)
 276     c->p_corrupt = atoi(av[0]);
 277   else
 278     c->p_corrupt = 5;
 279   f->state = c;
 280   f->func = docorrupt;
 281 }
 282
 283 /*----- Delay filter ------------------------------------------------------*/
 284
 285 typedef struct delaynode {
 286   unsigned flag;
 287   sel_timer tm;
 288   unsigned i;
 289   struct delay *d;
 290   octet *buf;
 291   size_t sz;
 292   unsigned seq;
 293 } delaynode;
 294
 295 typedef struct delay {
 296   unsigned max, n;
 297   unsigned long t;
 298   unsigned p_replay;
 299   filter *f;
 300   delaynode *q;
 301 } delay;
 302
 303 static void dtimer(struct timeval *tv, void *vv);
 304
 305 static void dinsert(delaynode *dn)
 306 {
 307   struct timeval tv;
 308   sel_timer *ta, *tb;
 309   unsigned long tdelta = RND(dn->d->t);
 310   gettimeofday(&tv, 0);
 311   TV_ADDL(&tv, &tv, 0, tdelta);
 312   assert(!dn->flag);
 313   sel_addtimer(&sel, &dn->tm, &tv, dtimer, dn);
 314   dn->flag = 1;
 315   for (ta = tb = sel.timers; ta; ta = ta->next) {
 316     ta = ta->next; if (!ta) break; assert(ta != tb);
 317     ta = ta->next; if (!ta) break; assert(ta != tb);
 318     tb = tb->next;
 319   }
 320   printf(" delay %lu usecs", tdelta);
 321 }
 322
 323 static void dsend(delaynode *dn, unsigned force)
 324 {
 325   delay *d = dn->d;
 326   delaynode *ddn;
 327   fputs(" send...\n", stdout);
 328   assert(dn->buf);
 329   PASS(d->f->next, dn->buf, dn->sz);
 330   fputs("delay ...", stdout);
 331   if (!force)
 332     dinsert(dn);
 333   else {
 334     xfree(dn->buf);
 335     dn->buf = 0;
 336     d->n--;
 337     if (dn->i < d->n) {
 338       ddn = &d->q[d->n];
 339       sel_rmtimer(&ddn->tm);
 340       sel_addtimer(&sel, &dn->tm, &ddn->tm.tv, dtimer, dn);
 341       dn->flag = 1;
 342       dn->buf = ddn->buf;
 343       dn->sz = ddn->sz;
 344       dn->seq = ddn->seq;
 345       ddn->buf = 0;
 346       ddn->flag = 0;
 347       printf(" move id %u from slot %u to slot %u", ddn->seq, ddn->i, dn->i);
 348     }
 349     { unsigned i; for (i = 0; i < d->n; i++) assert(d->q[i].buf); }
 350     fputs(" remove", stdout);
 351   }
 352 }
 353
 354 static void dtimer(struct timeval *tv, void *vv)
 355 {
 356   delaynode *dn = vv;
 357   printf("delay timer peer `%s' id %u slot %u",
 358          dn->d->f->p_from->name, dn->seq, dn->i);
 359   dn->flag = 0;
 360   dsend(dn, RND(dn->d->p_replay));
 361   fputc('\n', stdout);
 362 }
 363
 364 static void dodelay(filter *f, const octet *buf, size_t sz)
 365 {
 366   delay *d = f->state;
 367   delaynode *dn;
 368   static unsigned seq = 0;
 369
 370   fputs("delay", stdout);
 371   if (d->n == d->max) {
 372     dn = &d->q[RND(d->n)];
 373     printf(" force uid %u", dn->seq);
 374     sel_rmtimer(&dn->tm);
 375     dn->flag = 0;
 376     dsend(dn, 1);
 377     fputc(';', stdout);
 378   }
 379   dn = &d->q[d->n++];
 380   dn->seq = seq++;
 381   printf(" new id %u in slot %u", dn->seq, dn->i);
 382   dn->buf = xmalloc(sz);
 383   dn->sz = sz;
 384   memcpy(dn->buf, buf, sz);
 385   dinsert(dn);
 386   fputc('\n', stdout);
 387 }
 388
 389 static void adddelay(filter *f, unsigned ac, char **av)
 390 {
 391   delay *d;
 392   unsigned i;
 393
 394   if (ac < 1 || ac > 3)
 395     die(1, "syntax: filt:delay:QLEN[:MILLIS:PREPLAY]");
 396   d = CREATE(delay);
 397   d->max = atoi(av[0]);
 398   if (ac > 1)
 399     d->t = strtoul(av[1], 0, 10);
 400   else
 401     d->t = 100;
 402   d->t *= 1000;
 403   if (ac > 2)
 404     d->p_replay = atoi(av[2]);
 405   else
 406     d->p_replay = 20;
 407   d->n = 0;
 408   d->q = xmalloc(d->max * sizeof(delaynode));
 409   d->f = f;
 410   f->state = d;
 411   f->func = dodelay;
 412   for (i = 0; i < d->max; i++) {
 413     d->q[i].d = d;
 414     d->q[i].i = i;
 415     d->q[i].buf = 0;
 416     d->q[i].flag = 0;
 417   }
 418 }
 419
 420 /*----- Filters -----------------------------------------------------------*/
 421
 422 static void dosend(filter *f, const octet *buf, size_t sz)
 423 {
 424   printf("send to `%s'\n", f->p_to->name);
 425   write(f->p_to->sf.fd, buf, sz);
 426 }
 427
 428 static void addsend(filter *f, unsigned ac, char **av)
 429 {
 430   if (ac)
 431     die(1, "syntax: filt:send");
 432   f->func = dosend;
 433 }
 434
 435 const struct filtab {
 436   const char *name;
 437   void (*func)(filter */*f*/, unsigned /*ac*/, char **/*av*/);
 438 } filtab[] = {
 439   { "send",     addsend },
 440   { "fork",     addfork },
 441   { "delay",    adddelay },
 442   { "corrupt",  addcorrupt },
 443   { 0,          0 }
 444 };
 445
 446 static void dofilter(peer *from, peer *to, unsigned ac, char **av)
 447 {
 448   filter **ff, *f = CREATE(filter);
 449   const struct filtab *ft;
 450   if (ac < 1)
 451     die(1, "syntax: {l,r,}filt:NAME:...");
 452   f->next = 0;
 453   f->p_from = from;
 454   f->p_to = to;
 455   f->state = 0;
 456   for (ff = &from->f; *ff; ff = &(*ff)->next)
 457     ;
 458   *ff = f;
 459   for (ft = filtab; ft->name; ft++) {
 460     if (strcmp(av[0], ft->name) == 0) {
 461       ft->func(f, ac - 1, av + 1);
 462       return;
 463     }
 464   }
 465   die(1, "unknown filter `%s'", av[0]);
 466 }
 467
 468 /*----- Flooding ----------------------------------------------------------*/
 469
 470 typedef struct flood {
 471   peer *p;
 472   unsigned type;
 473   size_t sz;
 474   unsigned long t;
 475   sel_timer tm;
 476 } flood;
 477
 478 static void setflood(flood *f);
 479
 480 static void floodtimer(struct timeval *tv, void *vv)
 481 {
 482   flood *f = vv;
 483   octet buf[PKBUFSZ];
 484   size_t sz;
 485
 486   sz = RND(f->sz);
 487   sz += RND(f->sz);
 488   sz += RND(f->sz);
 489   sz += RND(f->sz);
 490   sz /= 2;
 491
 492   rng->ops->fill(rng, buf, sz);
 493   if (f->type < 0x100)
 494     buf[0] = f->type;
 495   puts("flood packet");
 496   PASS(f->p->f, buf, sz);
 497   setflood(f);
 498 }
 499
 500 static void setflood(flood *f)
 501 {
 502   struct timeval tv;
 503   gettimeofday(&tv, 0);
 504   TV_ADDL(&tv, &tv, 0, RND(f->t));
 505   sel_addtimer(&sel, &f->tm, &tv, floodtimer, f);
 506 }
 507
 508 static void doflood(peer *p, unsigned ac, char **av)
 509 {
 510   flood *f;
 511   if (ac > 3)
 512     die(1, "syntax: flood[:TYPE:MILLIS:SIZE]");
 513   f = CREATE(flood);
 514   f->p = p;
 515   if (ac > 0)
 516     f->type = strtoul(av[0], 0, 16);
 517   else
 518     f->type = 0x100;
 519   if (ac > 1)
 520     f->t = atoi(av[1]);
 521   else
 522     f->t = 10;
 523   if (ac > 2)
 524     f->sz = atoi(av[2]);
 525   else
 526     f->sz = 128;
 527   f->t *= 1000;
 528   setflood(f);
 529 }
 530
 531 /*----- Configuration commands --------------------------------------------*/
 532
 533 static void parse(char *p);
 534
 535 static void addflood(unsigned ac, char **av) {
 536   doflood(&peers[0], ac, av);
 537   doflood(&peers[1], ac, av);
 538 }
 539 static void addlflood(unsigned ac, char **av) {
 540   doflood(&peers[0], ac, av);
 541 }
 542 static void addrflood(unsigned ac, char **av) {
 543   doflood(&peers[1], ac, av);
 544 }
 545
 546 static void addfilter(unsigned ac, char **av) {
 547   dofilter(&peers[0], &peers[1], ac, av);
 548   dofilter(&peers[1], &peers[0], ac, av);
 549 }
 550 static void addlfilter(unsigned ac, char **av) {
 551   dofilter(&peers[0], &peers[1], ac, av);
 552 }
 553 static void addrfilter(unsigned ac, char **av) {
 554   dofilter(&peers[1], &peers[0], ac, av);
 555 }
 556
 557 static void include(unsigned ac, char **av)
 558 {
 559   FILE *fp;
 560   dstr d = DSTR_INIT;
 561   if (!ac)
 562     die(1, "syntax: include:FILE:...");
 563   while (*av) {
 564     if ((fp = fopen(*av, "r")) == 0)
 565       die(1, "fopen `%s': %s", *av, strerror(errno));
 566     while (dstr_putline(&d, fp) != EOF) {
 567       parse(d.buf);
 568       DRESET(&d);
 569     }
 570     fclose(fp);
 571     av++;
 572   }
 573 }
 574
 575 const struct cmdtab {
 576   const char *name;
 577   void (*func)(unsigned /*ac*/, char **/*av*/);
 578 } cmdtab[] = {
 579   { "peer",     addpeer },
 580   { "include",  include },
 581   { "filt",     addfilter },
 582   { "lfilt",    addlfilter },
 583   { "rfilt",    addrfilter },
 584   { "next",     nextfork },
 585   { "flood",    addflood },
 586   { "lflood",   addlflood },
 587   { "rflood",   addrflood },
 588   { 0,          0 }
 589 };
 590
 591 #define AVMAX 16
 592
 593 static void parse(char *p)
 594 {
 595   char *v[AVMAX];
 596   unsigned c = 0;
 597   const struct cmdtab *ct;
 598
 599   p = strtok(p, ":");
 600   if (!p || *p == '#')
 601     return;
 602   do {
 603     v[c++] = p;
 604     p = strtok(0, ":");
 605   } while (p && c < AVMAX - 1);
 606   v[c] = 0;
 607   for (ct = cmdtab; ct->name; ct++) {
 608     if (strcmp(ct->name, v[0]) == 0) {
 609       ct->func(c - 1, v + 1);
 610       return;
 611     }
 612   }
 613   die(1, "unknown command `%s'", v[0]);
 614 }
 615
 616 /*----- Main driver -------------------------------------------------------*/
 617
 618 static void version(FILE *fp)
 619 {
 620   pquis(fp, "$, TrIPE version " VERSION "\n");
 621 }
 622
 623 static void usage(FILE *fp)
 624 {
 625   pquis(fp, "Usage: $ [-k keyring] directive...\n");
 626 }
 627
 628 static void help(FILE *fp)
 629 {
 630   version(fp);
 631   putc('\n', fp);
 632   usage(fp);
 633 }
 634
 635 int main(int argc, char *argv[])
 636 {
 637   const char *kfname = "keyring.pub";
 638   int i;
 639   unsigned f = 0;
 640   char buf[16];
 641
 642 #define f_bogus 1u
 643
 644   ego(argv[0]);
 645   for (;;) {
 646     static const struct option opt[] = {
 647       { "help",         0,              0,      'h' },
 648       { "version",      0,              0,      'v' },
 649       { "usage",        0,              0,      'u' },
 650       { "keyring",      OPTF_ARGREQ,    0,      'k' },
 651       { 0,              0,              0,      0 }
 652     };
 653     if ((i = mdwopt(argc, argv, "hvuk:", opt, 0, 0, 0)) < 0)
 654       break;
 655     switch (i) {
 656       case 'h':
 657         help(stdout);
 658         exit(0);
 659       case 'v':
 660         version(stdout);
 661         exit(0);
 662       case 'u':
 663         usage(stdout);
 664         exit(0);
 665       case 'k':
 666         kfname = optarg;
 667         break;
 668       default:
 669         f |= f_bogus;
 670         break;
 671     }
 672   }
 673   if (f & f_bogus) {
 674     usage(stderr);
 675     exit(1);
 676   }
 677   rand_noisesrc(RAND_GLOBAL, &noise_source);
 678   rand_seed(RAND_GLOBAL, 160);
 679   rand_get(RAND_GLOBAL, buf, sizeof(buf));
 680   rng = rc4_rand(buf, sizeof(buf));
 681   sel_init(&sel);
 682   if (key_open(&keys, kfname, KOPEN_READ, key_moan, 0))
 683     die(1, "couldn't open `%s': %s", kfname, strerror(errno));
 684   for (i = optind; i < argc; i++)
 685     parse(argv[i]);
 686   if (npeer != 2)
 687     die(1, "need two peers");
 688   for (;;)
 689     sel_select(&sel);
 690
 691 #undef f_bogus
 692 }
 693
 694 /*----- That's all, folks -------------------------------------------------*/