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

   1 /* -*-c-*-
   2  *
   3  * $Id$
   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 /*----- Header files ------------------------------------------------------*/
  30
  31 #include "config.h"
  32
  33 #include <assert.h>
  34 #include <errno.h>
  35 #include <stdio.h>
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include <time.h>
  39
  40 #include <sys/types.h>
  41 #include <sys/time.h>
  42 #include <unistd.h>
  43 #include <fcntl.h>
  44
  45 #include <sys/socket.h>
  46 #include <netinet/in.h>
  47 #include <arpa/inet.h>
  48 #include <netdb.h>
  49
  50 #include <mLib/alloc.h>
  51 #include <mLib/dstr.h>
  52 #include <mLib/fdflags.h>
  53 #include <mLib/mdwopt.h>
  54 #include <mLib/quis.h>
  55 #include <mLib/report.h>
  56 #include <mLib/sel.h>
  57 #include <mLib/sub.h>
  58 #include <mLib/tv.h>
  59
  60 #include <catacomb/buf.h>
  61
  62 #include <catacomb/key.h>
  63
  64 #include <catacomb/mp.h>
  65 #include <catacomb/mprand.h>
  66 #include <catacomb/dh.h>
  67
  68 #include <catacomb/noise.h>
  69 #include <catacomb/rand.h>
  70 #include <catacomb/rc4.h>
  71
  72 /*----- Data structures ---------------------------------------------------*/
  73
  74 typedef struct peer {
  75   sel_file sf;
  76   dh_pub kpub;
  77   const char *name;
  78   struct filter *f;
  79 } peer;
  80
  81 typedef struct filter {
  82   struct filter *next;
  83   peer *p_from, *p_to;
  84   void (*func)(struct filter */*f*/, const octet */*buf*/, size_t /*sz*/);
  85   void *state;
  86 } filter;
  87
  88 typedef struct qnode {
  89   octet *buf;
  90   size_t sz;
  91 } qnode;
  92
  93 /*----- Static variables --------------------------------------------------*/
  94
  95 #define PKBUFSZ 65536
  96
  97 static sel_state sel;
  98 static peer peers[2];
  99 static unsigned npeer = 0;
 100 static key_file keys;
 101 static grand *rng;
 102
 103 #define PASS(f, buf, sz) ((f) ? (f)->func((f), (buf), (sz)) : (void)0)
 104 #define RND(i) (rng->ops->range(rng, (i)))
 105
 106 /*----- Peer management ---------------------------------------------------*/
 107
 108 static void dopacket(int fd, unsigned mode, void *vv)
 109 {
 110   octet buf[PKBUFSZ];
 111   peer *p = vv;
 112   int r = read(fd, buf, sizeof(buf));
 113   if (r >= 0) {
 114     printf("recv from `%s'\n", p->name);
 115     PASS(p->f, buf, r);
 116   }
 117 }
 118
 119 static void addpeer(unsigned ac, char **av)
 120 {
 121   key_packstruct kps[DH_PUBFETCHSZ];
 122   key_packdef *kp;
 123   struct hostent *h;
 124   struct sockaddr_in sin;
 125   int len = PKBUFSZ;
 126   peer *p;
 127   int fd;
 128   int e;
 129
 130   if (ac != 4)
 131     die(1, "syntax: peer:NAME:PORT:ADDR:PORT");
 132   if (npeer >= 2)
 133     die(1, "enough peers already");
 134   p = &peers[npeer++];
 135   p->name = xstrdup(av[0]);
 136   kp = key_fetchinit(dh_pubfetch, kps, &p->kpub);
 137   e = key_fetchbyname(kp, &keys, av[0]);
 138   key_fetchdone(kp);
 139   if (e)
 140     die(1, "key_fetch `%s': %s", av[0], key_strerror(e));
 141   if ((fd = socket(PF_INET, SOCK_DGRAM, 0)) < 0)
 142     die(1, "socket: %s", strerror(errno));
 143   fdflags(fd, O_NONBLOCK, O_NONBLOCK, FD_CLOEXEC, FD_CLOEXEC);
 144   memset(&sin, 0, sizeof(sin));
 145   sin.sin_family = AF_INET;
 146   sin.sin_addr.s_addr = INADDR_ANY;
 147   sin.sin_port = htons(atoi(av[1]));
 148   if (bind(fd, (struct sockaddr *)&sin, sizeof(sin)))
 149     die(1, "bind: %s", strerror(errno));
 150   memset(&sin, 0, sizeof(sin));
 151   sin.sin_family = AF_INET;
 152   if ((h = gethostbyname(av[2])) == 0)
 153     die(1, "gethostbyname `%s'", av[2]);
 154   if (setsockopt(fd, SOL_SOCKET, SO_RCVBUF, &len, sizeof(len)) ||
 155       setsockopt(fd, SOL_SOCKET, SO_SNDBUF, &len, sizeof(len)))
 156     die(1, "setsockopt: %s", strerror(errno));
 157   memcpy(&sin.sin_addr, h->h_addr, sizeof(sin.sin_addr));
 158   sin.sin_port = htons(atoi(av[3]));
 159   if (connect(fd, (struct sockaddr *)&sin, sizeof(sin)))
 160     die(1, "connect: %s", strerror(errno));
 161   sel_initfile(&sel, &p->sf, fd, SEL_READ, dopacket, p);
 162   sel_addfile(&p->sf);
 163 }
 164
 165 /*----- Fork filter -------------------------------------------------------*/
 166
 167 typedef struct forknode {
 168   struct forknode *next;
 169   filter *f;
 170 } forknode;
 171
 172 typedef struct forkfilt {
 173   const char *name;
 174   forknode *fn;
 175 } forkfilt;
 176
 177 static void dofork(filter *f, const octet *buf, size_t sz)
 178 {
 179   forkfilt *ff = f->state;
 180   forknode *fn;
 181   unsigned i = 0;
 182
 183   ff = f->state;
 184   for (fn = ff->fn; fn; fn = fn->next) {
 185     printf("fork branch %u of fork `%s'\n", i++, ff->name);
 186     PASS(fn->f, buf, sz);
 187   }
 188   printf("fork branch %u of fork `%s'\n", i++, ff->name);
 189   PASS(f->next, buf, sz);
 190 }
 191
 192 static void addfork(filter *f, unsigned ac, char **av)
 193 {
 194   forkfilt *ff;
 195   if (ac != 1)
 196     die(1, "syntax: filt:fork:NAME");
 197   ff = CREATE(forkfilt);
 198   ff->name = xstrdup(av[0]);
 199   ff->fn = 0;
 200   f->func = dofork;
 201   f->state = ff;
 202 }
 203
 204 static void nextfork(unsigned ac, char **av)
 205 {
 206   unsigned i, j;
 207   filter *f;
 208   forkfilt *ff;
 209   forknode *fn, **ffn;
 210   peer *p;
 211
 212   if (ac < 1)
 213     die(1, "syntax: next:NAME:...");
 214   for (i = 0; i < 2; i++) {
 215     p = &peers[i];
 216     for (f = p->f; f; f = f->next) {
 217       if (f->func != dofork)
 218         continue;
 219       ff = f->state;
 220       for (j = 0; j < ac; j++) {
 221         if (strcmp(av[j], ff->name) == 0)
 222           goto match;
 223       }
 224       continue;
 225     match:
 226       fn = CREATE(forknode);
 227       for (ffn = &ff->fn; *ffn; ffn = &(*ffn)->next)
 228         ;
 229       fn->f = f->next;
 230       f->next = 0;
 231       fn->next = 0;
 232       *ffn = fn;
 233     }
 234   }
 235 }
 236
 237 /*----- Corrupt filter ----------------------------------------------------*/
 238
 239 typedef struct corrupt {
 240   unsigned p_corrupt;
 241 } corrupt;
 242
 243 static void docorrupt(filter *f, const octet *buf, size_t sz)
 244 {
 245   corrupt *c = f->state;
 246   octet b[PKBUFSZ];
 247   memcpy(b, buf, sz);
 248
 249   while (!RND(c->p_corrupt)) {
 250     puts("corrupt packet");
 251     b[RND(sz)] ^= RND(256);
 252   }
 253   PASS(f->next, b, sz);
 254 }
 255
 256 static void addcorrupt(filter *f, unsigned ac, char **av)
 257 {
 258   corrupt *c;
 259   if (ac > 1)
 260     die(1, "syntax: filt:corrupt[:PCORRUPT]");
 261   c = CREATE(corrupt);
 262   if (ac > 0)
 263     c->p_corrupt = atoi(av[0]);
 264   else
 265     c->p_corrupt = 5;
 266   f->state = c;
 267   f->func = docorrupt;
 268 }
 269
 270 /*----- Delay filter ------------------------------------------------------*/
 271
 272 typedef struct delaynode {
 273   unsigned flag;
 274   sel_timer tm;
 275   unsigned i;
 276   struct delay *d;
 277   octet *buf;
 278   size_t sz;
 279   unsigned seq;
 280 } delaynode;
 281
 282 typedef struct delay {
 283   unsigned max, n;
 284   unsigned long t;
 285   unsigned p_replay;
 286   filter *f;
 287   delaynode *q;
 288 } delay;
 289
 290 static void dtimer(struct timeval *tv, void *vv);
 291
 292 static void dinsert(delaynode *dn)
 293 {
 294   struct timeval tv;
 295   sel_timer *ta, *tb;
 296   unsigned long tdelta = RND(dn->d->t);
 297   gettimeofday(&tv, 0);
 298   TV_ADDL(&tv, &tv, 0, tdelta);
 299   assert(!dn->flag);
 300   sel_addtimer(&sel, &dn->tm, &tv, dtimer, dn);
 301   dn->flag = 1;
 302   for (ta = tb = sel.timers; ta; ta = ta->next) {
 303     ta = ta->next; if (!ta) break; assert(ta != tb);
 304     ta = ta->next; if (!ta) break; assert(ta != tb);
 305     tb = tb->next;
 306   }
 307   printf(" delay %lu usecs", tdelta);
 308 }
 309
 310 static void dsend(delaynode *dn, unsigned force)
 311 {
 312   delay *d = dn->d;
 313   delaynode *ddn;
 314   fputs(" send...\n", stdout);
 315   assert(dn->buf);
 316   PASS(d->f->next, dn->buf, dn->sz);
 317   fputs("delay ...", stdout);
 318   if (!force)
 319     dinsert(dn);
 320   else {
 321     xfree(dn->buf);
 322     dn->buf = 0;
 323     d->n--;
 324     if (dn->i < d->n) {
 325       ddn = &d->q[d->n];
 326       sel_rmtimer(&ddn->tm);
 327       sel_addtimer(&sel, &dn->tm, &ddn->tm.tv, dtimer, dn);
 328       dn->flag = 1;
 329       dn->buf = ddn->buf;
 330       dn->sz = ddn->sz;
 331       dn->seq = ddn->seq;
 332       ddn->buf = 0;
 333       ddn->flag = 0;
 334       printf(" move id %u from slot %u to slot %u", ddn->seq, ddn->i, dn->i);
 335     }
 336     { unsigned i; for (i = 0; i < d->n; i++) assert(d->q[i].buf); }
 337     fputs(" remove", stdout);
 338   }
 339 }
 340
 341 static void dtimer(struct timeval *tv, void *vv)
 342 {
 343   delaynode *dn = vv;
 344   printf("delay timer peer `%s' id %u slot %u",
 345          dn->d->f->p_from->name, dn->seq, dn->i);
 346   dn->flag = 0;
 347   dsend(dn, RND(dn->d->p_replay));
 348   fputc('\n', stdout);
 349 }
 350
 351 static void dodelay(filter *f, const octet *buf, size_t sz)
 352 {
 353   delay *d = f->state;
 354   delaynode *dn;
 355   static unsigned seq = 0;
 356
 357   fputs("delay", stdout);
 358   if (d->n == d->max) {
 359     dn = &d->q[RND(d->n)];
 360     printf(" force uid %u", dn->seq);
 361     sel_rmtimer(&dn->tm);
 362     dn->flag = 0;
 363     dsend(dn, 1);
 364     fputc(';', stdout);
 365   }
 366   dn = &d->q[d->n++];
 367   dn->seq = seq++;
 368   printf(" new id %u in slot %u", dn->seq, dn->i);
 369   dn->buf = xmalloc(sz);
 370   dn->sz = sz;
 371   memcpy(dn->buf, buf, sz);
 372   dinsert(dn);
 373   fputc('\n', stdout);
 374 }
 375
 376 static void adddelay(filter *f, unsigned ac, char **av)
 377 {
 378   delay *d;
 379   unsigned i;
 380
 381   if (ac < 1 || ac > 3)
 382     die(1, "syntax: filt:delay:QLEN[:MILLIS:PREPLAY]");
 383   d = CREATE(delay);
 384   d->max = atoi(av[0]);
 385   if (ac > 1)
 386     d->t = strtoul(av[1], 0, 10);
 387   else
 388     d->t = 100;
 389   d->t *= 1000;
 390   if (ac > 2)
 391     d->p_replay = atoi(av[2]);
 392   else
 393     d->p_replay = 20;
 394   d->n = 0;
 395   d->q = xmalloc(d->max * sizeof(delaynode));
 396   d->f = f;
 397   f->state = d;
 398   f->func = dodelay;
 399   for (i = 0; i < d->max; i++) {
 400     d->q[i].d = d;
 401     d->q[i].i = i;
 402     d->q[i].buf = 0;
 403     d->q[i].flag = 0;
 404   }
 405 }
 406
 407 /*----- Filters -----------------------------------------------------------*/
 408
 409 static void dosend(filter *f, const octet *buf, size_t sz)
 410 {
 411   printf("send to `%s'\n", f->p_to->name);
 412   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 -------------------------------------------------*/