contrib/opie/opieauto.c

   1 /* opieauto.c: The opieauto program.
   2
   3 %%% copyright-cmetz-96
   4 This software is Copyright 1996-2001 by Craig Metz, All Rights Reserved.
   5 The Inner Net License Version 3 applies to this software.
   6 You should have received a copy of the license with this software. If
   7 you didn't get a copy, you may request one from <license@inner.net>.
   8
   9         History:
  10
  11         Created by cmetz for OPIE 2.4 based on previously released
  12                 test code. Use opiestrncpy().
  13 */
  14
  15 #include "opie_cfg.h"
  16 #include <sys/types.h>
  17 #include <sys/socket.h>
  18 #include <sys/un.h>
  19 #if HAVE_SYS_TIME_H
  20 #include <sys/time.h>
  21 #endif /* HAVE_SYS_TIME_H */
  22 #include <stdio.h>
  23 #include <errno.h>
  24 #if HAVE_STRING_H
  25 #include <string.h>
  26 #endif /* HAVE_STRING_H */
  27 #include <getopt.h>
  28 #if HAVE_STDLIB_H
  29 #include <stdlib.h>
  30 #endif /* HAVE_STDLIB_H */
  31 #if HAVE_UNISTD_H
  32 #include <unistd.h>
  33 #endif /* HAVE_UNISTD_H */
  34 #include <sys/stat.h>
  35
  36 #include "opie.h"
  37
  38 #ifndef max
  39 #define max(x, y) (((x) > (y)) ? (x) : (y))
  40 #endif /* max */
  41
  42 int window = 10;
  43 char *myname = NULL;
  44
  45 uid_t myuid = 0;
  46
  47 #define MAXCLIENTS 2
  48 int parents, s[MAXCLIENTS + 1];
  49
  50 char cmd[1+1+1+1+4+1+OPIE_SEED_MAX+1+4+1+4+1+4+1+4+1];
  51
  52 struct cachedotp {
  53   struct cachedotp *next;
  54   int algorithm, base, current;
  55   struct opie_otpkey basekey;
  56   char seed[OPIE_SEED_MAX+1];
  57 };
  58
  59 struct cachedotp *head = NULL;
  60
  61 char *algids[] = { NULL, NULL, NULL, "sha1", "md4", "md5" };
  62
  63 void baile(x) {
  64   fprintf(stderr, "%s: %s: %s(%d)\n", myname, x, strerror(errno), errno);
  65   exit(1);
  66 }
  67
  68 void bail(x) {
  69   fprintf(stderr, "%s: %s\n", myname, x);
  70   exit(1);
  71 }
  72
  73 void zerocache(void)
  74 {
  75   struct cachedotp *c = head, *c2;
  76
  77   while(c) {
  78     c2 = c->next;
  79     memset(c, 0, sizeof(struct cachedotp));
  80     c = c2;
  81   };
  82 };
  83
  84 int doreq(int fd)
  85 {
  86   int algorithm, sequence, i;
  87   char *seed = NULL, *response = NULL;
  88
  89   if (((cmd[0] != 'S') && (cmd[0] != 's')) || (cmd[1] != '=') || (cmd[2] != ' ')) {
  90 #if DEBUG
  91     fprintf(stderr, "%s: got bogus command: %s\n", myname, cmd);
  92 #endif /* DEBUG */
  93     goto error;
  94   };
  95
  96   {
  97   char *c;
  98
  99   if (((algorithm = strtoul(&cmd[3], &c, 10)) < 3) || (algorithm > 5) || (*c != ' ')) {
 100 #if DEBUG
 101     fprintf(stderr, "%s: got bogus algorithm: %s\n", myname, cmd);
 102 #endif /* DEBUG */
 103     goto error;
 104   };
 105
 106   if (((sequence = strtoul(c + 1, &c, 10)) <= OPIE_SEQUENCE_RESTRICT) || (sequence > OPIE_SEQUENCE_MAX)) {
 107 #if DEBUG
 108     fprintf(stderr, "%s: got bogus sequence: %s\n", myname, cmd);
 109 #endif /* DEBUG */
 110     goto error;
 111   };
 112
 113   if (cmd[0] == 'S') {
 114     if (!(c = strchr(seed = c + 1, ' '))) {
 115 #if DEBUG
 116       fprintf(stderr, "%s: got bogus seed: %s\n", myname, cmd);
 117 #endif /* DEBUG */
 118       goto error;
 119     };
 120
 121     *c = 0;
 122
 123     if (!(c = strchr(response = c + 1, '\n'))) {
 124 #if DEBUG
 125       fprintf(stderr, "%s: got bogus response: %s\n", myname, cmd);
 126 #endif /* DEBUG */
 127       goto error;
 128     };
 129
 130     *c = 0;
 131   } else {
 132     if (!(c = strchr(seed = c + 1, '\n'))) {
 133 #if DEBUG
 134       fprintf(stderr, "%s: got bogus seed: %s\n", myname, cmd);
 135 #endif /* DEBUG */
 136       goto error;
 137     };
 138
 139     *c = 0;
 140   };
 141   };
 142
 143 #if DEBUG
 144   fprintf(stderr, "got cmd=%c, algorithm=%d sequence=%d seed=+%s+ response=+%s+ on fd %d\n", cmd[0], algorithm, sequence, seed, response, fd);
 145 #endif /* DEBUG */
 146
 147   seed = strdup(seed);
 148
 149   if (sequence < 10) {
 150 #if DEBUG
 151     fprintf(stderr, "sequence < 10; can't do it\n");
 152 #endif /* DEBUG */
 153     sprintf(cmd, "%c- %d %d %s\n", cmd[0], algorithm, sequence, seed);
 154   };
 155
 156   {
 157   struct cachedotp **c;
 158
 159   for (c = &head; *c && (strcmp((*c)->seed, seed) || ((*c)->algorithm != algorithm)); c = &((*c)->next));
 160   if (!(*c)) {
 161     if (cmd[0] == 's') {
 162 #if DEBUG
 163       fprintf(stderr, "(seed, algorithm) not found for s command\n");
 164 #endif /* DEBUG */
 165       sprintf(cmd, "s- %d %d %s\n", algorithm, sequence, seed);
 166       goto out;
 167     }
 168
 169     if (!(*c = malloc(sizeof(struct cachedotp))))
 170       baile("malloc");
 171     memset(*c, 0, sizeof(struct cachedotp));
 172
 173     (*c)->algorithm = algorithm;
 174     opiestrncpy((*c)->seed, seed, OPIE_SEED_MAX);
 175   };
 176
 177   if (cmd[0] == 'S') {
 178     (*c)->base = max(sequence - window + 1, OPIE_SEQUENCE_RESTRICT);
 179     (*c)->current = sequence;
 180
 181     if (!opieatob8(&(*c)->basekey, response))
 182       goto error;
 183
 184     sprintf(cmd, "S+ %d %d %s\n", algorithm, sequence, (*c)->seed);
 185   } else {
 186     if (sequence != ((*c)->current - 1)) {
 187 #if DEBUG
 188       fprintf(stderr, "out of sequence: sequence=%d, base=%d, current=%d\n", sequence, (*c)->base, (*c)->current);
 189 #endif /* DEBUG */
 190       sprintf(cmd, "s- %d %d %s\n", algorithm, sequence, (*c)->seed);
 191       goto out;
 192     };
 193
 194     if (sequence < (*c)->base) {
 195 #if DEBUG
 196       fprintf(stderr, "attempt to generate below base: sequence=%d, base=%d, current=%d\n", sequence, (*c)->base, (*c)->current);
 197 #endif /* DEBUG */
 198       sprintf(cmd, "s- %d %d %s\n", algorithm, sequence, (*c)->seed);
 199       goto out;
 200     };
 201
 202     (*c)->current = sequence;
 203     i = sequence - (*c)->base;
 204     {
 205       struct opie_otpkey key;
 206       char buffer[16+1];
 207
 208       key = (*c)->basekey;
 209       while(i--)
 210         opiehash(&key, algorithm);
 211
 212       opiebtoa8(buffer, &key);
 213       sprintf(cmd, "s+ %d %d %s %s\n", algorithm, sequence, (*c)->seed, buffer);
 214     };
 215   };
 216
 217   printf("%c otp-%s %d %s (%d/%d)\n", cmd[0], algids[algorithm], sequence, (*c)->seed, sequence - (*c)->base, window);
 218   fflush(stdout);
 219
 220   if (sequence == (*c)->base) {
 221     struct cachedotp *c2 = *c;
 222     *c = (*c)->next;
 223     memset(c2, 0, sizeof(struct cachedotp));
 224     free(c2);
 225   };
 226   };
 227
 228 out:
 229   write(fd, cmd, i = strlen(cmd));
 230   free(seed);
 231   return 0;
 232
 233 error:
 234   fprintf(stderr, "Invalid command on fd %d\n", fd);
 235   if (seed)
 236     free(seed);
 237   return -1;
 238 }
 239
 240 static void usage()
 241 {
 242   fprintf(stderr, "usage: %s [-v] [-h] [-q] [-n <number of OTPs>]\n", myname);
 243   exit(1);
 244 }
 245
 246 int main(int argc, char **argv)
 247 {
 248   int i;
 249   struct stat st;
 250   char *sockpath;
 251
 252   if (myname = strrchr(argv[0], '/'))
 253     myname++;
 254   else
 255     myname = argv[0];
 256
 257   while((i = getopt(argc, argv, "w:hv")) != EOF) {
 258     switch(i) {
 259       case 'v':
 260         opieversion();
 261
 262       case 'w':
 263         if (!(window = atoi(optarg))) {
 264           fprintf(stderr, "%s: invalid number of OTPs: %s\n", myname, optarg);
 265           exit(1);
 266         };
 267         break;
 268
 269       default:
 270         usage();
 271     }
 272   };
 273
 274   {
 275     uid_t myeuid;
 276
 277     if (!(myuid = getuid()) || !(myeuid = geteuid()) || (myuid != myeuid))
 278       bail("this program must not be run with superuser priveleges or setuid.");
 279   };
 280
 281   if (atexit(zerocache) < 0)
 282     baile("atexit");
 283
 284   {
 285     struct sockaddr_un sun;
 286
 287     memset(&sun, 0, sizeof(struct sockaddr_un));
 288     sun.sun_family = AF_UNIX;
 289
 290     {
 291     char *c;
 292     char *c2 = "/.opieauto";
 293
 294     if (!(c = getenv("HOME")))
 295       bail("getenv(HOME) failed -- no HOME variable?");
 296
 297     if (strlen(c) > (sizeof(sun.sun_path) - strlen(c2) - 1))
 298       bail("your HOME is too long");
 299
 300     strcpy(sun.sun_path, c);
 301     strcat(sun.sun_path, c2);
 302     sockpath = strdup(sun.sun_path);
 303     };
 304
 305     if ((parents = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
 306       baile("socket");
 307
 308     if (unlink(sockpath) && (errno != ENOENT))
 309       baile("unlink");
 310
 311     if (umask(0177) < 0)
 312       baile("umask");
 313
 314     if (bind(parents, (struct sockaddr *)&sun, sizeof(struct sockaddr_un)))
 315       baile("bind");
 316
 317     if (stat(sockpath, &st) < 0)
 318       baile("stat");
 319
 320     if ((st.st_uid != myuid) || (!S_ISSOCK(st.st_mode)) || ((st.st_mode & 07777) != 0600))
 321       bail("socket permissions and/or ownership were not correctly created.");
 322
 323     if (listen(parents, 1) < 0)
 324       baile("listen");
 325   };
 326
 327   {
 328     fd_set fds, rfds, efds;
 329     int maxfd = parents;
 330     int i, j;
 331
 332     FD_ZERO(&fds);
 333     FD_SET(parents, &fds);
 334
 335     while(1) {
 336       memcpy(&rfds, &fds, sizeof(fd_set));
 337
 338       if (select(maxfd + 1, &rfds, NULL, NULL, NULL) < 0)
 339         baile("select");
 340
 341       for (i = 0; s[i]; i++) {
 342         if (!FD_ISSET(s[i], &rfds))
 343           continue;
 344
 345         if (((j = read(s[i], cmd, sizeof(cmd)-1)) <= 0) || ((cmd[j] = 0) || doreq(s[i]))) {
 346           close(s[i]);
 347           FD_CLR(s[i], &fds);
 348
 349           if (s[i] == maxfd)
 350             maxfd--;
 351
 352           for (j = i; s[j]; s[j] = s[j + 1], j++);
 353           FD_SET(parents, &fds);
 354           i--;
 355           continue;
 356         };
 357       };
 358
 359       if (FD_ISSET(parents, &rfds)) {
 360         for (i = 0; s[i]; i++)
 361           if (i > MAXCLIENTS)
 362             bail("this message never printed");
 363
 364         if (stat(sockpath, &st) < 0)
 365           baile("stat");
 366
 367         if ((st.st_uid != myuid) || (!S_ISSOCK(st.st_mode)) || ((st.st_mode & 07777) != 0600))
 368           bail("socket permissions and/or ownership has been messed with.");
 369
 370         if ((s[i] = accept(parents, NULL, 0)) < 0)
 371           baile("accept");
 372
 373         FD_SET(s[i], &fds);
 374         if (s[i] > maxfd)
 375           maxfd = s[i];
 376
 377         sprintf(cmd, "C+ %d\n", window);
 378         if (write(s[i], cmd, j = strlen(cmd)) != j)
 379           baile("write");
 380
 381         if (++i == MAXCLIENTS)
 382           FD_CLR(parents, &fds);
 383       }
 384     }
 385   }
 386 }