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

   1 /* -*-c-*-
   2  *
   3  * An evil proxy for TrIPE
   4  *
   5  * (c) 2001 Straylight/Edgeware
   6  */
   7
   8 /*----- Licensing notice --------------------------------------------------*
   9  *
  10  * This file is part of Trivial IP Encryption (TrIPE).
  11  *
  12  * TrIPE 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  * TrIPE 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 TrIPE; if not, write to the Free Software Foundation,
  24  * Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
  25  */
  26
  27 /*----- Header files ------------------------------------------------------*/
  28
  29 #include "config.h"
  30
  31 #include <assert.h>
  32 #include <errno.h>
  33 #include <stdio.h>
  34 #include <stdlib.h>
  35 #include <string.h>
  36 #include <time.h>
  37
  38 #include <sys/types.h>
  39 #include <sys/time.h>
  40 #include <unistd.h>
  41 #include <fcntl.h>
  42
  43 #include <sys/socket.h>
  44 #include <netinet/in.h>
  45 #include <arpa/inet.h>
  46 #include <netdb.h>
  47
  48 #include <mLib/alloc.h>
  49 #include <mLib/dstr.h>
  50 #include <mLib/fdflags.h>
  51 #include <mLib/mdwopt.h>
  52 #include <mLib/quis.h>
  53 #include <mLib/report.h>
  54 #include <mLib/sel.h>
  55 #include <mLib/sub.h>
  56 #include <mLib/tv.h>
  57
  58 #include <catacomb/buf.h>
  59
  60 #include <catacomb/key.h>
  61
  62 #include <catacomb/mp.h>
  63 #include <catacomb/mprand.h>
  64 #include <catacomb/dh.h>
  65
  66 #include <catacomb/noise.h>
  67 #include <catacomb/rand.h>
  68 #include <catacomb/rc4.h>
  69
  70 /*----- Data structures ---------------------------------------------------*/
  71
  72 typedef struct peer {
  73   sel_file sf;
  74   dh_pub kpub;
  75   const char *name;
  76   struct filter *f;
  77 } peer;
  78
  79 typedef struct filter {
  80   struct filter *next;
  81   peer *p_from, *p_to;
  82   void (*func)(struct filter */*f*/, const octet */*buf*/, size_t /*sz*/);
  83   void *state;
  84 } filter;
  85
  86 typedef struct qnode {
  87   octet *buf;
  88   size_t sz;
  89 } qnode;
  90
  91 /*----- Static variables --------------------------------------------------*/
  92
  93 #define PKBUFSZ 65536
  94
  95 static sel_state sel;
  96 static peer peers[2];
  97 static unsigned npeer = 0;
  98 static key_file keys;
  99 static grand *rng;
 100
 101 #define PASS(f, buf, sz) ((f) ? (f)->func((f), (buf), (sz)) : (void)0)
 102 #define RND(i) (rng->ops->range(rng, (i)))
 103
 104 /*----- Peer management ---------------------------------------------------*/
 105
 106 static void dopacket(int fd, unsigned mode, void *vv)
 107 {
 108   octet buf[PKBUFSZ];
 109   peer *p = vv;
 110   int r = read(fd, buf, sizeof(buf));
 111   if (r >= 0) {
 112     printf("recv from `%s'\n", p->name);
 113     PASS(p->f, buf, r);
 114   }
 115 }
 116
 117 static void addpeer(unsigned ac, char **av)
 118 {
 119   key_packstruct kps[DH_PUBFETCHSZ];
 120   key_packdef *kp;
 121   struct hostent *h;
 122   struct sockaddr_in sin;
 123   int len = PKBUFSZ;
 124   peer *p;
 125   int fd;
 126   int e;
 127
 128   if (ac != 4)
 129     die(1, "syntax: peer:NAME:PORT:ADDR:PORT");
 130   if (npeer >= 2)
 131     die(1, "enough peers already");
 132   p = &peers[npeer++];
 133   p->name = xstrdup(av[0]);
 134   kp = key_fetchinit(dh_pubfetch, kps, &p->kpub);
 135   e = key_fetchbyname(kp, &keys, av[0]);
 136   key_fetchdone(kp);
 137   if (e)
 138     die(1, "key_fetch `%s': %s", av[0], key_strerror(e));
 139   if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
 140     die(1, "socket: %s", strerror(errno));
 141   fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
 142   memset(&sin, 0, sizeof(sin));
 143   sin.sin_family = AF_INET;
 144   sin.sin_addr.s_addr = INADDR_ANY;
 145   sin.sin_port = htons(atoi(av[1]));
 146   if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)))
 147     die(1, "bind: %s", strerror(errno));
 148   memset(&sin, 0, sizeof(sin));
 149   sin.sin_family = AF_INET;
 150   if ((h = gethostbyname(av[2])) == 0)
 151     die(1, "gethostbyname `%s'", av[2]);
 152   if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
 153       setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len)))
 154     die(1, "setsockopt: %s", strerror(errno));
 155   memcpy(&sin.sin_addr, h->h_addr, sizeof(sin.sin_addr));
 156   sin.sin_port = htons(atoi(av[3]));
 157   if (connect(fd, (struct sockaddr *)&sin, sizeof(sin)))
 158     die(1, "connect: %s", strerror(errno));
 159   sel_initfile(&sel, &p->sf, fd, SEL_READ, dopacket, p);
 160   sel_addfile(&p->sf);
 161 }
 162
 163 /*----- Fork filter -------------------------------------------------------*/
 164
 165 typedef struct forknode {
 166   struct forknode *next;
 167   filter *f;
 168 } forknode;
 169
 170 typedef struct forkfilt {
 171   const char *name;
 172   forknode *fn;
 173 } forkfilt;
 174
 175 static void dofork(filter *f, const octet *buf, size_t sz)
 176 {
 177   forkfilt *ff = f->state;
 178   forknode *fn;
 179   unsigned i = 0;
 180
 181   ff = f->state;
 182   for (fn = ff->fn; fn; fn = fn->next) {
 183     printf("fork branch %u of fork `%s'\n", i++, ff->name);
 184     PASS(fn->f, buf, sz);
 185   }
 186   printf("fork branch %u of fork `%s'\n", i++, ff->name);
 187   PASS(f->next, buf, sz);
 188 }
 189
 190 static void addfork(filter *f, unsigned ac, char **av)
 191 {
 192   forkfilt *ff;
 193   if (ac != 1)
 194     die(1, "syntax: filt:fork:NAME");
 195   ff = CREATE(forkfilt);
 196   ff->name = xstrdup(av[0]);
 197   ff->fn = 0;
 198   f->func = dofork;
 199   f->state = ff;
 200 }
 201
 202 static void nextfork(unsigned ac, char **av)
 203 {
 204   unsigned i, j;
 205   filter *f;
 206   forkfilt *ff;
 207   forknode *fn, **ffn;
 208   peer *p;
 209
 210   if (ac < 1)
 211     die(1, "syntax: next:NAME:...");
 212   for (i = 0; i < 2; i++) {
 213     p = &peers[i];
 214     for (f = p->f; f; f = f->next) {
 215       if (f->func != dofork)
 216         continue;
 217       ff = f->state;
 218       for (j = 0; j < ac; j++) {
 219         if (strcmp(av[j], ff->name) == 0)
 220           goto match;
 221       }
 222       continue;
 223     match:
 224       fn = CREATE(forknode);
 225       for (ffn = &ff->fn; *ffn; ffn = &(*ffn)->next)
 226         ;
 227       fn->f = f->next;
 228       f->next = 0;
 229       fn->next = 0;
 230       *ffn = fn;
 231     }
 232   }
 233 }
 234
 235 /*----- Corrupt filter ----------------------------------------------------*/
 236
 237 typedef struct corrupt {
 238   unsigned p_corrupt;
 239 } corrupt;
 240
 241 static void docorrupt(filter *f, const octet *buf, size_t sz)
 242 {
 243   corrupt *c = f->state;
 244   octet b[PKBUFSZ];
 245   memcpy(b, buf, sz);
 246
 247   while (!RND(c->p_corrupt)) {
 248     puts("corrupt packet");
 249     b[RND(sz)] ^= RND(256);
 250   }
 251   PASS(f->next, b, sz);
 252 }
 253
 254 static void addcorrupt(filter *f, unsigned ac, char **av)
 255 {
 256   corrupt *c;
 257   if (ac > 1)
 258     die(1, "syntax: filt:corrupt[:PCORRUPT]");
 259   c = CREATE(corrupt);
 260   if (ac > 0)
 261     c->p_corrupt = atoi(av[0]);
 262   else
 263     c->p_corrupt = 5;
 264   f->state = c;
 265   f->func = docorrupt;
 266 }
 267
 268 /*----- Delay filter ------------------------------------------------------*/
 269
 270 typedef struct delaynode {
 271   unsigned flag;
 272   sel_timer tm;
 273   unsigned i;
 274   struct delay *d;
 275   octet *buf;
 276   size_t sz;
 277   unsigned seq;
 278 } delaynode;
 279
 280 typedef struct delay {
 281   unsigned max, n;
 282   unsigned long t;
 283   unsigned p_replay;
 284   filter *f;
 285   delaynode *q;
 286 } delay;
 287
 288 static void dtimer(struct timeval *tv, void *vv);
 289
 290 static void dinsert(delaynode *dn)
 291 {
 292   struct timeval tv;
 293   sel_timer *ta, *tb;
 294   unsigned long tdelta = RND(dn->d->t);
 295   gettimeofday(&tv, 0);
 296   TV_ADDL(&tv, &tv, 0, tdelta);
 297   assert(!dn->flag);
 298   sel_addtimer(&sel, &dn->tm, &tv, dtimer, dn);
 299   dn->flag = 1;
 300   for (ta = tb = sel.timers; ta; ta = ta->next) {
 301     ta = ta->next; if (!ta) break; assert(ta != tb);
 302     ta = ta->next; if (!ta) break; assert(ta != tb);
 303     tb = tb->next;
 304   }
 305   printf(" delay %lu usecs", tdelta);
 306 }
 307
 308 static void dsend(delaynode *dn, unsigned force)
 309 {
 310   delay *d = dn->d;
 311   delaynode *ddn;
 312   fputs(" send...\n", stdout);
 313   assert(dn->buf);
 314   PASS(d->f->next, dn->buf, dn->sz);
 315   fputs("delay ...", stdout);
 316   if (!force)
 317     dinsert(dn);
 318   else {
 319     xfree(dn->buf);
 320     dn->buf = 0;
 321     d->n--;
 322     if (dn->i < d->n) {
 323       ddn = &d->q[d->n];
 324       sel_rmtimer(&ddn->tm);
 325       sel_addtimer(&sel, &dn->tm, &ddn->tm.tv, dtimer, dn);
 326       dn->flag = 1;
 327       dn->buf = ddn->buf;
 328       dn->sz = ddn->sz;
 329       dn->seq = ddn->seq;
 330       ddn->buf = 0;
 331       ddn->flag = 0;
 332       printf(" move id %u from slot %u to slot %u", ddn->seq, ddn->i, dn->i);
 333     }
 334     { unsigned i; for (i = 0; i < d->n; i++) assert(d->q[i].buf); }
 335     fputs(" remove", stdout);
 336   }
 337 }
 338
 339 static void dtimer(struct timeval *tv, void *vv)
 340 {
 341   delaynode *dn = vv;
 342   printf("delay timer peer `%s' id %u slot %u",
 343          dn->d->f->p_from->name, dn->seq, dn->i);
 344   dn->flag = 0;
 345   dsend(dn, RND(dn->d->p_replay));
 346   fputc('\n', stdout);
 347 }
 348
 349 static void dodelay(filter *f, const octet *buf, size_t sz)
 350 {
 351   delay *d = f->state;
 352   delaynode *dn;
 353   static unsigned seq = 0;
 354
 355   fputs("delay", stdout);
 356   if (d->n == d->max) {
 357     dn = &d->q[RND(d->n)];
 358     printf(" force uid %u", dn->seq);
 359     sel_rmtimer(&dn->tm);
 360     dn->flag = 0;
 361     dsend(dn, 1);
 362     fputc(';', stdout);
 363   }
 364   dn = &d->q[d->n++];
 365   dn->seq = seq++;
 366   printf(" new id %u in slot %u", dn->seq, dn->i);
 367   dn->buf = xmalloc(sz);
 368   dn->sz = sz;
 369   memcpy(dn->buf, buf, sz);
 370   dinsert(dn);
 371   fputc('\n', stdout);
 372 }
 373
 374 static void adddelay(filter *f, unsigned ac, char **av)
 375 {
 376   delay *d;
 377   unsigned i;
 378
 379   if (ac < 1 || ac > 3)
 380     die(1, "syntax: filt:delay:QLEN[:MILLIS:PREPLAY]");
 381   d = CREATE(delay);
 382   d->max = atoi(av[0]);
 383   if (ac > 1)
 384     d->t = strtoul(av[1], 0, 10);
 385   else
 386     d->t = 100;
 387   d->t *= 1000;
 388   if (ac > 2)
 389     d->p_replay = atoi(av[2]);
 390   else
 391     d->p_replay = 20;
 392   d->n = 0;
 393   d->q = xmalloc(d->max * sizeof(delaynode));
 394   d->f = f;
 395   f->state = d;
 396   f->func = dodelay;
 397   for (i = 0; i < d->max; i++) {
 398     d->q[i].d = d;
 399     d->q[i].i = i;
 400     d->q[i].buf = 0;
 401     d->q[i].flag = 0;
 402   }
 403 }
 404
 405 /*----- Filters -----------------------------------------------------------*/
 406
 407 static void dosend(filter *f, const octet *buf, size_t sz)
 408 {
 409   int hunoz;
 410
 411   printf("send to `%s'\n", f->p_to->name);
 412   hunoz = write(f->p_to->sf.fd, buf, sz);
 413 }
 414
 415 static void addsend(filter *f, unsigned ac, char **av)
 416 {
 417   if (ac)
 418     die(1, "syntax: filt:send");
 419   f->func = dosend;
 420 }
 421
 422 const struct filtab {
 423   const char *name;
 424   void (*func)(filter */*f*/, unsigned /*ac*/, char **/*av*/);
 425 } filtab[] = {
 426   { "send",     addsend },
 427   { "fork",     addfork },
 428   { "delay",    adddelay },
 429   { "corrupt",  addcorrupt },
 430   { 0,          0 }
 431 };
 432
 433 static void dofilter(peer *from, peer *to, unsigned ac, char **av)
 434 {
 435   filter **ff, *f = CREATE(filter);
 436   const struct filtab *ft;
 437   if (ac < 1)
 438     die(1, "syntax: {l,r,}filt:NAME:...");
 439   f->next = 0;
 440   f->p_from = from;
 441   f->p_to = to;
 442   f->state = 0;
 443   for (ff = &from->f; *ff; ff = &(*ff)->next)
 444     ;
 445   *ff = f;
 446   for (ft = filtab; ft->name; ft++) {
 447     if (strcmp(av[0], ft->name) == 0) {
 448       ft->func(f, ac - 1, av + 1);
 449       return;
 450     }
 451   }
 452   die(1, "unknown filter `%s'", av[0]);
 453 }
 454
 455 /*----- Flooding ----------------------------------------------------------*/
 456
 457 typedef struct flood {
 458   peer *p;
 459   unsigned type;
 460   size_t sz;
 461   unsigned long t;
 462   sel_timer tm;
 463 } flood;
 464
 465 static void setflood(flood *f);
 466
 467 static void floodtimer(struct timeval *tv, void *vv)
 468 {
 469   flood *f = vv;
 470   octet buf[PKBUFSZ];
 471   size_t sz;
 472
 473   sz = RND(f->sz);
 474   sz += RND(f->sz);
 475   sz += RND(f->sz);
 476   sz += RND(f->sz);
 477   sz /= 2;
 478
 479   rng->ops->fill(rng, buf, sz);
 480   if (f->type < 0x100)
 481     buf[0] = f->type;
 482   puts("flood packet");
 483   PASS(f->p->f, buf, sz);
 484   setflood(f);
 485 }
 486
 487 static void setflood(flood *f)
 488 {
 489   struct timeval tv;
 490   gettimeofday(&tv, 0);
 491   TV_ADDL(&tv, &tv, 0, RND(f->t));
 492   sel_addtimer(&sel, &f->tm, &tv, floodtimer, f);
 493 }
 494
 495 static void doflood(peer *p, unsigned ac, char **av)
 496 {
 497   flood *f;
 498   if (ac > 3)
 499     die(1, "syntax: flood[:TYPE:MILLIS:SIZE]");
 500   f = CREATE(flood);
 501   f->p = p;
 502   if (ac > 0)
 503     f->type = strtoul(av[0], 0, 16);
 504   else
 505     f->type = 0x100;
 506   if (ac > 1)
 507     f->t = atoi(av[1]);
 508   else
 509     f->t = 10;
 510   if (ac > 2)
 511     f->sz = atoi(av[2]);
 512   else
 513     f->sz = 128;
 514   f->t *= 1000;
 515   setflood(f);
 516 }
 517
 518 /*----- Configuration commands --------------------------------------------*/
 519
 520 static void parse(char *p);
 521
 522 static void addflood(unsigned ac, char **av) {
 523   doflood(&peers[0], ac, av);
 524   doflood(&peers[1], ac, av);
 525 }
 526 static void addlflood(unsigned ac, char **av) {
 527   doflood(&peers[0], ac, av);
 528 }
 529 static void addrflood(unsigned ac, char **av) {
 530   doflood(&peers[1], ac, av);
 531 }
 532
 533 static void addfilter(unsigned ac, char **av) {
 534   dofilter(&peers[0], &peers[1], ac, av);
 535   dofilter(&peers[1], &peers[0], ac, av);
 536 }
 537 static void addlfilter(unsigned ac, char **av) {
 538   dofilter(&peers[0], &peers[1], ac, av);
 539 }
 540 static void addrfilter(unsigned ac, char **av) {
 541   dofilter(&peers[1], &peers[0], ac, av);
 542 }
 543
 544 static void include(unsigned ac, char **av)
 545 {
 546   FILE *fp;
 547   dstr d = DSTR_INIT;
 548   if (!ac)
 549     die(1, "syntax: include:FILE:...");
 550   while (*av) {
 551     if ((fp = fopen(*av, "r")) == 0)
 552       die(1, "fopen `%s': %s", *av, strerror(errno));
 553     while (dstr_putline(&d, fp) != EOF) {
 554       parse(d.buf);
 555       DRESET(&d);
 556     }
 557     fclose(fp);
 558     av++;
 559   }
 560 }
 561
 562 const struct cmdtab {
 563   const char *name;
 564   void (*func)(unsigned /*ac*/, char **/*av*/);
 565 } cmdtab[] = {
 566   { "peer",     addpeer },
 567   { "include",  include },
 568   { "filt",     addfilter },
 569   { "lfilt",    addlfilter },
 570   { "rfilt",    addrfilter },
 571   { "next",     nextfork },
 572   { "flood",    addflood },
 573   { "lflood",   addlflood },
 574   { "rflood",   addrflood },
 575   { 0,          0 }
 576 };
 577
 578 #define AVMAX 16
 579
 580 static void parse(char *p)
 581 {
 582   char *v[AVMAX];
 583   unsigned c = 0;
 584   const struct cmdtab *ct;
 585
 586   p = strtok(p, ":");
 587   if (!p || *p == '#')
 588     return;
 589   do {
 590     v[c++] = p;
 591     p = strtok(0, ":");
 592   } while (p && c < AVMAX - 1);
 593   v[c] = 0;
 594   for (ct = cmdtab; ct->name; ct++) {
 595     if (strcmp(ct->name, v[0]) == 0) {
 596       ct->func(c - 1, v + 1);
 597       return;
 598     }
 599   }
 600   die(1, "unknown command `%s'", v[0]);
 601 }
 602
 603 /*----- Main driver -------------------------------------------------------*/
 604
 605 static void version(FILE *fp)
 606   { pquis(fp, "$, TrIPE version " VERSION "\n"); }
 607
 608 static void usage(FILE *fp)
 609   { pquis(fp, "Usage: $ [-k KEYRING] DIRECTIVE...\n"); }
 610
 611 static void help(FILE *fp)
 612 {
 613   version(fp);
 614   putc('\n', fp);
 615   usage(fp);
 616   fputs("\n\
 617 Options:\n\
 618 \n\
 619 -h, --help              Show this help text.\n\
 620 -v, --version           Show the version number.\n\
 621 -u, --usage             Show terse usage summary.\n\
 622 \n\
 623 -k, --keyring=FILE      Fetch keys from FILE.\n\
 624 \n\
 625 Directives:\n\
 626   peer:NAME:LOCAL-PORT:REMOTE-ADDR:REMOTE-PORT\n\
 627   include:FILE\n\
 628   {,l,r}filt:FILTER:ARGS:...\n\
 629   next:TAG\n\
 630   {,l,r}flood:TYPE:MILLIS:SIZE\n\
 631 \n\
 632 Filters:\n\
 633   send\n\
 634   fork:TAG\n\
 635   delay:QLEN[:MILLIS:P-REPLAY]\n\
 636   corrupt[:P-CORRUPT]\n",
 637         fp);
 638 }
 639
 640 int main(int argc, char *argv[])
 641 {
 642   const char *kfname = "keyring.pub";
 643   int i;
 644   unsigned f = 0;
 645   char buf[16];
 646
 647 #define f_bogus 1u
 648
 649   ego(argv[0]);
 650   for (;;) {
 651     static const struct option opt[] = {
 652       { "help",         0,              0,      'h' },
 653       { "version",      0,              0,      'v' },
 654       { "usage",        0,              0,      'u' },
 655       { "keyring",      OPTF_ARGREQ,    0,      'k' },
 656       { 0,              0,              0,      0 }
 657     };
 658     if ((i = mdwopt(argc, argv, "hvuk:", opt, 0, 0, 0)) < 0)
 659       break;
 660     switch (i) {
 661       case 'h':
 662         help(stdout);
 663         exit(0);
 664       case 'v':
 665         version(stdout);
 666         exit(0);
 667       case 'u':
 668         usage(stdout);
 669         exit(0);
 670       case 'k':
 671         kfname = optarg;
 672         break;
 673       default:
 674         f |= f_bogus;
 675         break;
 676     }
 677   }
 678   if (f & f_bogus) {
 679     usage(stderr);
 680     exit(1);
 681   }
 682   rand_noisesrc(RAND_GLOBAL, &noise_source);
 683   rand_seed(RAND_GLOBAL, 160);
 684   rand_get(RAND_GLOBAL, buf, sizeof(buf));
 685   rng = rc4_rand(buf, sizeof(buf));
 686   sel_init(&sel);
 687   if (key_open(&keys, kfname, KOPEN_READ, key_moan, 0))
 688     die(1, "couldn't open `%s': %s", kfname, strerror(errno));
 689   for (i = optind; i < argc; i++)
 690     parse(argv[i]);
 691   if (npeer != 2)
 692     die(1, "need two peers");
 693   for (;;)
 694     sel_select(&sel);
 695
 696 #undef f_bogus
 697 }
 698
 699 /*----- That's all, folks -------------------------------------------------*/