ssh-keyscan.c

   1 /* $OpenBSD: ssh-keyscan.c,v 1.72 2006/08/01 23:22:47 stevesk Exp $ */
   2 /*
   3  * Copyright 1995, 1996 by David Mazieres <dm@lcs.mit.edu>.
   4  *
   5  * Modification and redistribution in source and binary forms is
   6  * permitted provided that due credit is given to the author and the
   7  * OpenBSD project by leaving this copyright notice intact.
   8  */
   9
  10 #include "includes.h"
  11
  12 #include "openbsd-compat/sys-queue.h"
  13 #include <sys/resource.h>
  14 #ifdef HAVE_SYS_TIME_H
  15 # include <sys/time.h>
  16 #endif
  17
  18 #include <openssl/bn.h>
  19
  20 #include <netdb.h>
  21 #include <errno.h>
  22 #include <setjmp.h>
  23 #include <stdarg.h>
  24 #include <stdio.h>
  25 #include <stdlib.h>
  26 #include <string.h>
  27 #include <unistd.h>
  28
  29 #include "xmalloc.h"
  30 #include "ssh.h"
  31 #include "ssh1.h"
  32 #include "key.h"
  33 #include "kex.h"
  34 #include "compat.h"
  35 #include "myproposal.h"
  36 #include "packet.h"
  37 #include "dispatch.h"
  38 #include "buffer.h"
  39 #include "bufaux.h"
  40 #include "log.h"
  41 #include "atomicio.h"
  42 #include "misc.h"
  43 #include "hostfile.h"
  44
  45 /* Flag indicating whether IPv4 or IPv6.  This can be set on the command line.
  46    Default value is AF_UNSPEC means both IPv4 and IPv6. */
  47 int IPv4or6 = AF_UNSPEC;
  48
  49 int ssh_port = SSH_DEFAULT_PORT;
  50
  51 #define KT_RSA1 1
  52 #define KT_DSA  2
  53 #define KT_RSA  4
  54
  55 int get_keytypes = KT_RSA1;     /* Get only RSA1 keys by default */
  56
  57 int hash_hosts = 0;             /* Hash hostname on output */
  58
  59 #define MAXMAXFD 256
  60
  61 /* The number of seconds after which to give up on a TCP connection */
  62 int timeout = 5;
  63
  64 int maxfd;
  65 #define MAXCON (maxfd - 10)
  66
  67 extern char *__progname;
  68 fd_set *read_wait;
  69 size_t read_wait_nfdset;
  70 int ncon;
  71 int nonfatal_fatal = 0;
  72 jmp_buf kexjmp;
  73 Key *kexjmp_key;
  74
  75 /*
  76  * Keep a connection structure for each file descriptor.  The state
  77  * associated with file descriptor n is held in fdcon[n].
  78  */
  79 typedef struct Connection {
  80         u_char c_status;        /* State of connection on this file desc. */
  81 #define CS_UNUSED 0             /* File descriptor unused */
  82 #define CS_CON 1                /* Waiting to connect/read greeting */
  83 #define CS_SIZE 2               /* Waiting to read initial packet size */
  84 #define CS_KEYS 3               /* Waiting to read public key packet */
  85         int c_fd;               /* Quick lookup: c->c_fd == c - fdcon */
  86         int c_plen;             /* Packet length field for ssh packet */
  87         int c_len;              /* Total bytes which must be read. */
  88         int c_off;              /* Length of data read so far. */
  89         int c_keytype;          /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
  90         char *c_namebase;       /* Address to free for c_name and c_namelist */
  91         char *c_name;           /* Hostname of connection for errors */
  92         char *c_namelist;       /* Pointer to other possible addresses */
  93         char *c_output_name;    /* Hostname of connection for output */
  94         char *c_data;           /* Data read from this fd */
  95         Kex *c_kex;             /* The key-exchange struct for ssh2 */
  96         struct timeval c_tv;    /* Time at which connection gets aborted */
  97         TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
  98 } con;
  99
 100 TAILQ_HEAD(conlist, Connection) tq;     /* Timeout Queue */
 101 con *fdcon;
 102
 103 /*
 104  *  This is just a wrapper around fgets() to make it usable.
 105  */
 106
 107 /* Stress-test.  Increase this later. */
 108 #define LINEBUF_SIZE 16
 109
 110 typedef struct {
 111         char *buf;
 112         u_int size;
 113         int lineno;
 114         const char *filename;
 115         FILE *stream;
 116         void (*errfun) (const char *,...);
 117 } Linebuf;
 118
 119 static Linebuf *
 120 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
 121 {
 122         Linebuf *lb;
 123
 124         if (!(lb = malloc(sizeof(*lb)))) {
 125                 if (errfun)
 126                         (*errfun) ("linebuf (%s): malloc failed\n",
 127                             filename ? filename : "(stdin)");
 128                 return (NULL);
 129         }
 130         if (filename) {
 131                 lb->filename = filename;
 132                 if (!(lb->stream = fopen(filename, "r"))) {
 133                         xfree(lb);
 134                         if (errfun)
 135                                 (*errfun) ("%s: %s\n", filename, strerror(errno));
 136                         return (NULL);
 137                 }
 138         } else {
 139                 lb->filename = "(stdin)";
 140                 lb->stream = stdin;
 141         }
 142
 143         if (!(lb->buf = malloc((lb->size = LINEBUF_SIZE)))) {
 144                 if (errfun)
 145                         (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
 146                 xfree(lb);
 147                 return (NULL);
 148         }
 149         lb->errfun = errfun;
 150         lb->lineno = 0;
 151         return (lb);
 152 }
 153
 154 static void
 155 Linebuf_free(Linebuf * lb)
 156 {
 157         fclose(lb->stream);
 158         xfree(lb->buf);
 159         xfree(lb);
 160 }
 161
 162 #if 0
 163 static void
 164 Linebuf_restart(Linebuf * lb)
 165 {
 166         clearerr(lb->stream);
 167         rewind(lb->stream);
 168         lb->lineno = 0;
 169 }
 170
 171 static int
 172 Linebuf_lineno(Linebuf * lb)
 173 {
 174         return (lb->lineno);
 175 }
 176 #endif
 177
 178 static char *
 179 Linebuf_getline(Linebuf * lb)
 180 {
 181         size_t n = 0;
 182         void *p;
 183
 184         lb->lineno++;
 185         for (;;) {
 186                 /* Read a line */
 187                 if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
 188                         if (ferror(lb->stream) && lb->errfun)
 189                                 (*lb->errfun)("%s: %s\n", lb->filename,
 190                                     strerror(errno));
 191                         return (NULL);
 192                 }
 193                 n = strlen(lb->buf);
 194
 195                 /* Return it or an error if it fits */
 196                 if (n > 0 && lb->buf[n - 1] == '\n') {
 197                         lb->buf[n - 1] = '\0';
 198                         return (lb->buf);
 199                 }
 200                 if (n != lb->size - 1) {
 201                         if (lb->errfun)
 202                                 (*lb->errfun)("%s: skipping incomplete last line\n",
 203                                     lb->filename);
 204                         return (NULL);
 205                 }
 206                 /* Double the buffer if we need more space */
 207                 lb->size *= 2;
 208                 if ((p = realloc(lb->buf, lb->size)) == NULL) {
 209                         lb->size /= 2;
 210                         if (lb->errfun)
 211                                 (*lb->errfun)("linebuf (%s): realloc failed\n",
 212                                     lb->filename);
 213                         return (NULL);
 214                 }
 215                 lb->buf = p;
 216         }
 217 }
 218
 219 static int
 220 fdlim_get(int hard)
 221 {
 222 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
 223         struct rlimit rlfd;
 224
 225         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 226                 return (-1);
 227         if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
 228                 return SSH_SYSFDMAX;
 229         else
 230                 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
 231 #else
 232         return SSH_SYSFDMAX;
 233 #endif
 234 }
 235
 236 static int
 237 fdlim_set(int lim)
 238 {
 239 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 240         struct rlimit rlfd;
 241 #endif
 242
 243         if (lim <= 0)
 244                 return (-1);
 245 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 246         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 247                 return (-1);
 248         rlfd.rlim_cur = lim;
 249         if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 250                 return (-1);
 251 #elif defined (HAVE_SETDTABLESIZE)
 252         setdtablesize(lim);
 253 #endif
 254         return (0);
 255 }
 256
 257 /*
 258  * This is an strsep function that returns a null field for adjacent
 259  * separators.  This is the same as the 4.4BSD strsep, but different from the
 260  * one in the GNU libc.
 261  */
 262 static char *
 263 xstrsep(char **str, const char *delim)
 264 {
 265         char *s, *e;
 266
 267         if (!**str)
 268                 return (NULL);
 269
 270         s = *str;
 271         e = s + strcspn(s, delim);
 272
 273         if (*e != '\0')
 274                 *e++ = '\0';
 275         *str = e;
 276
 277         return (s);
 278 }
 279
 280 /*
 281  * Get the next non-null token (like GNU strsep).  Strsep() will return a
 282  * null token for two adjacent separators, so we may have to loop.
 283  */
 284 static char *
 285 strnnsep(char **stringp, char *delim)
 286 {
 287         char *tok;
 288
 289         do {
 290                 tok = xstrsep(stringp, delim);
 291         } while (tok && *tok == '\0');
 292         return (tok);
 293 }
 294
 295 static Key *
 296 keygrab_ssh1(con *c)
 297 {
 298         static Key *rsa;
 299         static Buffer msg;
 300
 301         if (rsa == NULL) {
 302                 buffer_init(&msg);
 303                 rsa = key_new(KEY_RSA1);
 304         }
 305         buffer_append(&msg, c->c_data, c->c_plen);
 306         buffer_consume(&msg, 8 - (c->c_plen & 7));      /* padding */
 307         if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
 308                 error("%s: invalid packet type", c->c_name);
 309                 buffer_clear(&msg);
 310                 return NULL;
 311         }
 312         buffer_consume(&msg, 8);                /* cookie */
 313
 314         /* server key */
 315         (void) buffer_get_int(&msg);
 316         buffer_get_bignum(&msg, rsa->rsa->e);
 317         buffer_get_bignum(&msg, rsa->rsa->n);
 318
 319         /* host key */
 320         (void) buffer_get_int(&msg);
 321         buffer_get_bignum(&msg, rsa->rsa->e);
 322         buffer_get_bignum(&msg, rsa->rsa->n);
 323
 324         buffer_clear(&msg);
 325
 326         return (rsa);
 327 }
 328
 329 static int
 330 hostjump(Key *hostkey)
 331 {
 332         kexjmp_key = hostkey;
 333         longjmp(kexjmp, 1);
 334 }
 335
 336 static int
 337 ssh2_capable(int remote_major, int remote_minor)
 338 {
 339         switch (remote_major) {
 340         case 1:
 341                 if (remote_minor == 99)
 342                         return 1;
 343                 break;
 344         case 2:
 345                 return 1;
 346         default:
 347                 break;
 348         }
 349         return 0;
 350 }
 351
 352 static Key *
 353 keygrab_ssh2(con *c)
 354 {
 355         int j;
 356
 357         packet_set_connection(c->c_fd, c->c_fd);
 358         enable_compat20();
 359         myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
 360             "ssh-dss": "ssh-rsa";
 361         c->c_kex = kex_setup(myproposal);
 362         c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
 363         c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
 364         c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
 365         c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
 366         c->c_kex->verify_host_key = hostjump;
 367
 368         if (!(j = setjmp(kexjmp))) {
 369                 nonfatal_fatal = 1;
 370                 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
 371                 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
 372                 exit(1);
 373         }
 374         nonfatal_fatal = 0;
 375         xfree(c->c_kex);
 376         c->c_kex = NULL;
 377         packet_close();
 378
 379         return j < 0? NULL : kexjmp_key;
 380 }
 381
 382 static void
 383 keyprint(con *c, Key *key)
 384 {
 385         char *host = c->c_output_name ? c->c_output_name : c->c_name;
 386
 387         if (!key)
 388                 return;
 389         if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
 390                 fatal("host_hash failed");
 391
 392         fprintf(stdout, "%s ", host);
 393         key_write(key, stdout);
 394         fputs("\n", stdout);
 395 }
 396
 397 static int
 398 tcpconnect(char *host)
 399 {
 400         struct addrinfo hints, *ai, *aitop;
 401         char strport[NI_MAXSERV];
 402         int gaierr, s = -1;
 403
 404         snprintf(strport, sizeof strport, "%d", ssh_port);
 405         memset(&hints, 0, sizeof(hints));
 406         hints.ai_family = IPv4or6;
 407         hints.ai_socktype = SOCK_STREAM;
 408         if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
 409                 fatal("getaddrinfo %s: %s", host, gai_strerror(gaierr));
 410         for (ai = aitop; ai; ai = ai->ai_next) {
 411                 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 412                 if (s < 0) {
 413                         error("socket: %s", strerror(errno));
 414                         continue;
 415                 }
 416                 if (set_nonblock(s) == -1)
 417                         fatal("%s: set_nonblock(%d)", __func__, s);
 418                 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
 419                     errno != EINPROGRESS)
 420                         error("connect (`%s'): %s", host, strerror(errno));
 421                 else
 422                         break;
 423                 close(s);
 424                 s = -1;
 425         }
 426         freeaddrinfo(aitop);
 427         return s;
 428 }
 429
 430 static int
 431 conalloc(char *iname, char *oname, int keytype)
 432 {
 433         char *namebase, *name, *namelist;
 434         int s;
 435
 436         namebase = namelist = xstrdup(iname);
 437
 438         do {
 439                 name = xstrsep(&namelist, ",");
 440                 if (!name) {
 441                         xfree(namebase);
 442                         return (-1);
 443                 }
 444         } while ((s = tcpconnect(name)) < 0);
 445
 446         if (s >= maxfd)
 447                 fatal("conalloc: fdno %d too high", s);
 448         if (fdcon[s].c_status)
 449                 fatal("conalloc: attempt to reuse fdno %d", s);
 450
 451         fdcon[s].c_fd = s;
 452         fdcon[s].c_status = CS_CON;
 453         fdcon[s].c_namebase = namebase;
 454         fdcon[s].c_name = name;
 455         fdcon[s].c_namelist = namelist;
 456         fdcon[s].c_output_name = xstrdup(oname);
 457         fdcon[s].c_data = (char *) &fdcon[s].c_plen;
 458         fdcon[s].c_len = 4;
 459         fdcon[s].c_off = 0;
 460         fdcon[s].c_keytype = keytype;
 461         gettimeofday(&fdcon[s].c_tv, NULL);
 462         fdcon[s].c_tv.tv_sec += timeout;
 463         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 464         FD_SET(s, read_wait);
 465         ncon++;
 466         return (s);
 467 }
 468
 469 static void
 470 confree(int s)
 471 {
 472         if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
 473                 fatal("confree: attempt to free bad fdno %d", s);
 474         close(s);
 475         xfree(fdcon[s].c_namebase);
 476         xfree(fdcon[s].c_output_name);
 477         if (fdcon[s].c_status == CS_KEYS)
 478                 xfree(fdcon[s].c_data);
 479         fdcon[s].c_status = CS_UNUSED;
 480         fdcon[s].c_keytype = 0;
 481         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 482         FD_CLR(s, read_wait);
 483         ncon--;
 484 }
 485
 486 static void
 487 contouch(int s)
 488 {
 489         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 490         gettimeofday(&fdcon[s].c_tv, NULL);
 491         fdcon[s].c_tv.tv_sec += timeout;
 492         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 493 }
 494
 495 static int
 496 conrecycle(int s)
 497 {
 498         con *c = &fdcon[s];
 499         int ret;
 500
 501         ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
 502         confree(s);
 503         return (ret);
 504 }
 505
 506 static void
 507 congreet(int s)
 508 {
 509         int n = 0, remote_major = 0, remote_minor = 0;
 510         char buf[256], *cp;
 511         char remote_version[sizeof buf];
 512         size_t bufsiz;
 513         con *c = &fdcon[s];
 514
 515         for (;;) {
 516                 memset(buf, '\0', sizeof(buf));
 517                 bufsiz = sizeof(buf);
 518                 cp = buf;
 519                 while (bufsiz-- &&
 520                     (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
 521                         if (*cp == '\r')
 522                                 *cp = '\n';
 523                         cp++;
 524                 }
 525                 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
 526                         break;
 527         }
 528         if (n == 0) {
 529                 switch (errno) {
 530                 case EPIPE:
 531                         error("%s: Connection closed by remote host", c->c_name);
 532                         break;
 533                 case ECONNREFUSED:
 534                         break;
 535                 default:
 536                         error("read (%s): %s", c->c_name, strerror(errno));
 537                         break;
 538                 }
 539                 conrecycle(s);
 540                 return;
 541         }
 542         if (*cp != '\n' && *cp != '\r') {
 543                 error("%s: bad greeting", c->c_name);
 544                 confree(s);
 545                 return;
 546         }
 547         *cp = '\0';
 548         if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
 549             &remote_major, &remote_minor, remote_version) == 3)
 550                 compat_datafellows(remote_version);
 551         else
 552                 datafellows = 0;
 553         if (c->c_keytype != KT_RSA1) {
 554                 if (!ssh2_capable(remote_major, remote_minor)) {
 555                         debug("%s doesn't support ssh2", c->c_name);
 556                         confree(s);
 557                         return;
 558                 }
 559         } else if (remote_major != 1) {
 560                 debug("%s doesn't support ssh1", c->c_name);
 561                 confree(s);
 562                 return;
 563         }
 564         fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
 565         n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
 566             c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
 567             c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
 568         if (n < 0 || (size_t)n >= sizeof(buf)) {
 569                 error("snprintf: buffer too small");
 570                 confree(s);
 571                 return;
 572         }
 573         if (atomicio(vwrite, s, buf, n) != (size_t)n) {
 574                 error("write (%s): %s", c->c_name, strerror(errno));
 575                 confree(s);
 576                 return;
 577         }
 578         if (c->c_keytype != KT_RSA1) {
 579                 keyprint(c, keygrab_ssh2(c));
 580                 confree(s);
 581                 return;
 582         }
 583         c->c_status = CS_SIZE;
 584         contouch(s);
 585 }
 586
 587 static void
 588 conread(int s)
 589 {
 590         con *c = &fdcon[s];
 591         size_t n;
 592
 593         if (c->c_status == CS_CON) {
 594                 congreet(s);
 595                 return;
 596         }
 597         n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
 598         if (n == 0) {
 599                 error("read (%s): %s", c->c_name, strerror(errno));
 600                 confree(s);
 601                 return;
 602         }
 603         c->c_off += n;
 604
 605         if (c->c_off == c->c_len)
 606                 switch (c->c_status) {
 607                 case CS_SIZE:
 608                         c->c_plen = htonl(c->c_plen);
 609                         c->c_len = c->c_plen + 8 - (c->c_plen & 7);
 610                         c->c_off = 0;
 611                         c->c_data = xmalloc(c->c_len);
 612                         c->c_status = CS_KEYS;
 613                         break;
 614                 case CS_KEYS:
 615                         keyprint(c, keygrab_ssh1(c));
 616                         confree(s);
 617                         return;
 618                 default:
 619                         fatal("conread: invalid status %d", c->c_status);
 620                         break;
 621                 }
 622
 623         contouch(s);
 624 }
 625
 626 static void
 627 conloop(void)
 628 {
 629         struct timeval seltime, now;
 630         fd_set *r, *e;
 631         con *c;
 632         int i;
 633
 634         gettimeofday(&now, NULL);
 635         c = TAILQ_FIRST(&tq);
 636
 637         if (c && (c->c_tv.tv_sec > now.tv_sec ||
 638             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
 639                 seltime = c->c_tv;
 640                 seltime.tv_sec -= now.tv_sec;
 641                 seltime.tv_usec -= now.tv_usec;
 642                 if (seltime.tv_usec < 0) {
 643                         seltime.tv_usec += 1000000;
 644                         seltime.tv_sec--;
 645                 }
 646         } else
 647                 seltime.tv_sec = seltime.tv_usec = 0;
 648
 649         r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 650         e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 651         memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
 652         memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
 653
 654         while (select(maxfd, r, NULL, e, &seltime) == -1 &&
 655             (errno == EAGAIN || errno == EINTR))
 656                 ;
 657
 658         for (i = 0; i < maxfd; i++) {
 659                 if (FD_ISSET(i, e)) {
 660                         error("%s: exception!", fdcon[i].c_name);
 661                         confree(i);
 662                 } else if (FD_ISSET(i, r))
 663                         conread(i);
 664         }
 665         xfree(r);
 666         xfree(e);
 667
 668         c = TAILQ_FIRST(&tq);
 669         while (c && (c->c_tv.tv_sec < now.tv_sec ||
 670             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
 671                 int s = c->c_fd;
 672
 673                 c = TAILQ_NEXT(c, c_link);
 674                 conrecycle(s);
 675         }
 676 }
 677
 678 static void
 679 do_host(char *host)
 680 {
 681         char *name = strnnsep(&host, " \t\n");
 682         int j;
 683
 684         if (name == NULL)
 685                 return;
 686         for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
 687                 if (get_keytypes & j) {
 688                         while (ncon >= MAXCON)
 689                                 conloop();
 690                         conalloc(name, *host ? host : name, j);
 691                 }
 692         }
 693 }
 694
 695 void
 696 fatal(const char *fmt,...)
 697 {
 698         va_list args;
 699
 700         va_start(args, fmt);
 701         do_log(SYSLOG_LEVEL_FATAL, fmt, args);
 702         va_end(args);
 703         if (nonfatal_fatal)
 704                 longjmp(kexjmp, -1);
 705         else
 706                 exit(255);
 707 }
 708
 709 static void
 710 usage(void)
 711 {
 712         fprintf(stderr, "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
 713             "\t\t   [host | addrlist namelist] [...]\n",
 714             __progname);
 715         exit(1);
 716 }
 717
 718 int
 719 main(int argc, char **argv)
 720 {
 721         int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
 722         int opt, fopt_count = 0;
 723         char *tname;
 724
 725         extern int optind;
 726         extern char *optarg;
 727
 728         __progname = ssh_get_progname(argv[0]);
 729         init_rng();
 730         seed_rng();
 731         TAILQ_INIT(&tq);
 732
 733         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 734         sanitise_stdfd();
 735
 736         if (argc <= 1)
 737                 usage();
 738
 739         while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
 740                 switch (opt) {
 741                 case 'H':
 742                         hash_hosts = 1;
 743                         break;
 744                 case 'p':
 745                         ssh_port = a2port(optarg);
 746                         if (ssh_port == 0) {
 747                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 748                                 exit(1);
 749                         }
 750                         break;
 751                 case 'T':
 752                         timeout = convtime(optarg);
 753                         if (timeout == -1 || timeout == 0) {
 754                                 fprintf(stderr, "Bad timeout '%s'\n", optarg);
 755                                 usage();
 756                         }
 757                         break;
 758                 case 'v':
 759                         if (!debug_flag) {
 760                                 debug_flag = 1;
 761                                 log_level = SYSLOG_LEVEL_DEBUG1;
 762                         }
 763                         else if (log_level < SYSLOG_LEVEL_DEBUG3)
 764                                 log_level++;
 765                         else
 766                                 fatal("Too high debugging level.");
 767                         break;
 768                 case 'f':
 769                         if (strcmp(optarg, "-") == 0)
 770                                 optarg = NULL;
 771                         argv[fopt_count++] = optarg;
 772                         break;
 773                 case 't':
 774                         get_keytypes = 0;
 775                         tname = strtok(optarg, ",");
 776                         while (tname) {
 777                                 int type = key_type_from_name(tname);
 778                                 switch (type) {
 779                                 case KEY_RSA1:
 780                                         get_keytypes |= KT_RSA1;
 781                                         break;
 782                                 case KEY_DSA:
 783                                         get_keytypes |= KT_DSA;
 784                                         break;
 785                                 case KEY_RSA:
 786                                         get_keytypes |= KT_RSA;
 787                                         break;
 788                                 case KEY_UNSPEC:
 789                                         fatal("unknown key type %s", tname);
 790                                 }
 791                                 tname = strtok(NULL, ",");
 792                         }
 793                         break;
 794                 case '4':
 795                         IPv4or6 = AF_INET;
 796                         break;
 797                 case '6':
 798                         IPv4or6 = AF_INET6;
 799                         break;
 800                 case '?':
 801                 default:
 802                         usage();
 803                 }
 804         }
 805         if (optind == argc && !fopt_count)
 806                 usage();
 807
 808         log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
 809
 810         maxfd = fdlim_get(1);
 811         if (maxfd < 0)
 812                 fatal("%s: fdlim_get: bad value", __progname);
 813         if (maxfd > MAXMAXFD)
 814                 maxfd = MAXMAXFD;
 815         if (MAXCON <= 0)
 816                 fatal("%s: not enough file descriptors", __progname);
 817         if (maxfd > fdlim_get(0))
 818                 fdlim_set(maxfd);
 819         fdcon = xcalloc(maxfd, sizeof(con));
 820
 821         read_wait_nfdset = howmany(maxfd, NFDBITS);
 822         read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 823
 824         if (fopt_count) {
 825                 Linebuf *lb;
 826                 char *line;
 827                 int j;
 828
 829                 for (j = 0; j < fopt_count; j++) {
 830                         lb = Linebuf_alloc(argv[j], error);
 831                         if (!lb)
 832                                 continue;
 833                         while ((line = Linebuf_getline(lb)) != NULL)
 834                                 do_host(line);
 835                         Linebuf_free(lb);
 836                 }
 837         }
 838
 839         while (optind < argc)
 840                 do_host(argv[optind++]);
 841
 842         while (ncon > 0)
 843                 conloop();
 844
 845         return (0);
 846 }