ssh-keyscan.c

   1 /* $OpenBSD: ssh-keyscan.c,v 1.79 2009/10/28 16:38:18 reyk 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 <netinet/in.h>
  19 #include <arpa/inet.h>
  20
  21 #include <openssl/bn.h>
  22
  23 #include <netdb.h>
  24 #include <errno.h>
  25 #include <setjmp.h>
  26 #include <stdarg.h>
  27 #include <stdio.h>
  28 #include <stdlib.h>
  29 #include <signal.h>
  30 #include <string.h>
  31 #include <unistd.h>
  32
  33 #include "xmalloc.h"
  34 #include "ssh.h"
  35 #include "ssh1.h"
  36 #include "buffer.h"
  37 #include "key.h"
  38 #include "cipher.h"
  39 #include "kex.h"
  40 #include "compat.h"
  41 #include "myproposal.h"
  42 #include "packet.h"
  43 #include "dispatch.h"
  44 #include "log.h"
  45 #include "atomicio.h"
  46 #include "misc.h"
  47 #include "hostfile.h"
  48
  49 /* Flag indicating whether IPv4 or IPv6.  This can be set on the command line.
  50    Default value is AF_UNSPEC means both IPv4 and IPv6. */
  51 int IPv4or6 = AF_UNSPEC;
  52
  53 int ssh_port = SSH_DEFAULT_PORT;
  54
  55 #define KT_RSA1 1
  56 #define KT_DSA  2
  57 #define KT_RSA  4
  58
  59 int get_keytypes = KT_RSA;      /* Get only RSA keys by default */
  60
  61 int hash_hosts = 0;             /* Hash hostname on output */
  62
  63 #define MAXMAXFD 256
  64
  65 /* The number of seconds after which to give up on a TCP connection */
  66 int timeout = 5;
  67
  68 int maxfd;
  69 #define MAXCON (maxfd - 10)
  70
  71 /* The default routing domain */
  72 int scan_rdomain = -1;
  73
  74 extern char *__progname;
  75 fd_set *read_wait;
  76 size_t read_wait_nfdset;
  77 int ncon;
  78 int nonfatal_fatal = 0;
  79 jmp_buf kexjmp;
  80 Key *kexjmp_key;
  81
  82 /*
  83  * Keep a connection structure for each file descriptor.  The state
  84  * associated with file descriptor n is held in fdcon[n].
  85  */
  86 typedef struct Connection {
  87         u_char c_status;        /* State of connection on this file desc. */
  88 #define CS_UNUSED 0             /* File descriptor unused */
  89 #define CS_CON 1                /* Waiting to connect/read greeting */
  90 #define CS_SIZE 2               /* Waiting to read initial packet size */
  91 #define CS_KEYS 3               /* Waiting to read public key packet */
  92         int c_fd;               /* Quick lookup: c->c_fd == c - fdcon */
  93         int c_plen;             /* Packet length field for ssh packet */
  94         int c_len;              /* Total bytes which must be read. */
  95         int c_off;              /* Length of data read so far. */
  96         int c_keytype;          /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
  97         char *c_namebase;       /* Address to free for c_name and c_namelist */
  98         char *c_name;           /* Hostname of connection for errors */
  99         char *c_namelist;       /* Pointer to other possible addresses */
 100         char *c_output_name;    /* Hostname of connection for output */
 101         char *c_data;           /* Data read from this fd */
 102         Kex *c_kex;             /* The key-exchange struct for ssh2 */
 103         struct timeval c_tv;    /* Time at which connection gets aborted */
 104         TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
 105 } con;
 106
 107 TAILQ_HEAD(conlist, Connection) tq;     /* Timeout Queue */
 108 con *fdcon;
 109
 110 /*
 111  *  This is just a wrapper around fgets() to make it usable.
 112  */
 113
 114 /* Stress-test.  Increase this later. */
 115 #define LINEBUF_SIZE 16
 116
 117 typedef struct {
 118         char *buf;
 119         u_int size;
 120         int lineno;
 121         const char *filename;
 122         FILE *stream;
 123         void (*errfun) (const char *,...);
 124 } Linebuf;
 125
 126 static Linebuf *
 127 Linebuf_alloc(const char *filename, void (*errfun) (const char *,...))
 128 {
 129         Linebuf *lb;
 130
 131         if (!(lb = malloc(sizeof(*lb)))) {
 132                 if (errfun)
 133                         (*errfun) ("linebuf (%s): malloc failed\n",
 134                             filename ? filename : "(stdin)");
 135                 return (NULL);
 136         }
 137         if (filename) {
 138                 lb->filename = filename;
 139                 if (!(lb->stream = fopen(filename, "r"))) {
 140                         xfree(lb);
 141                         if (errfun)
 142                                 (*errfun) ("%s: %s\n", filename, strerror(errno));
 143                         return (NULL);
 144                 }
 145         } else {
 146                 lb->filename = "(stdin)";
 147                 lb->stream = stdin;
 148         }
 149
 150         if (!(lb->buf = malloc((lb->size = LINEBUF_SIZE)))) {
 151                 if (errfun)
 152                         (*errfun) ("linebuf (%s): malloc failed\n", lb->filename);
 153                 xfree(lb);
 154                 return (NULL);
 155         }
 156         lb->errfun = errfun;
 157         lb->lineno = 0;
 158         return (lb);
 159 }
 160
 161 static void
 162 Linebuf_free(Linebuf * lb)
 163 {
 164         fclose(lb->stream);
 165         xfree(lb->buf);
 166         xfree(lb);
 167 }
 168
 169 #if 0
 170 static void
 171 Linebuf_restart(Linebuf * lb)
 172 {
 173         clearerr(lb->stream);
 174         rewind(lb->stream);
 175         lb->lineno = 0;
 176 }
 177
 178 static int
 179 Linebuf_lineno(Linebuf * lb)
 180 {
 181         return (lb->lineno);
 182 }
 183 #endif
 184
 185 static char *
 186 Linebuf_getline(Linebuf * lb)
 187 {
 188         size_t n = 0;
 189         void *p;
 190
 191         lb->lineno++;
 192         for (;;) {
 193                 /* Read a line */
 194                 if (!fgets(&lb->buf[n], lb->size - n, lb->stream)) {
 195                         if (ferror(lb->stream) && lb->errfun)
 196                                 (*lb->errfun)("%s: %s\n", lb->filename,
 197                                     strerror(errno));
 198                         return (NULL);
 199                 }
 200                 n = strlen(lb->buf);
 201
 202                 /* Return it or an error if it fits */
 203                 if (n > 0 && lb->buf[n - 1] == '\n') {
 204                         lb->buf[n - 1] = '\0';
 205                         return (lb->buf);
 206                 }
 207                 if (n != lb->size - 1) {
 208                         if (lb->errfun)
 209                                 (*lb->errfun)("%s: skipping incomplete last line\n",
 210                                     lb->filename);
 211                         return (NULL);
 212                 }
 213                 /* Double the buffer if we need more space */
 214                 lb->size *= 2;
 215                 if ((p = realloc(lb->buf, lb->size)) == NULL) {
 216                         lb->size /= 2;
 217                         if (lb->errfun)
 218                                 (*lb->errfun)("linebuf (%s): realloc failed\n",
 219                                     lb->filename);
 220                         return (NULL);
 221                 }
 222                 lb->buf = p;
 223         }
 224 }
 225
 226 static int
 227 fdlim_get(int hard)
 228 {
 229 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
 230         struct rlimit rlfd;
 231
 232         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 233                 return (-1);
 234         if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
 235                 return SSH_SYSFDMAX;
 236         else
 237                 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
 238 #else
 239         return SSH_SYSFDMAX;
 240 #endif
 241 }
 242
 243 static int
 244 fdlim_set(int lim)
 245 {
 246 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 247         struct rlimit rlfd;
 248 #endif
 249
 250         if (lim <= 0)
 251                 return (-1);
 252 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 253         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 254                 return (-1);
 255         rlfd.rlim_cur = lim;
 256         if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 257                 return (-1);
 258 #elif defined (HAVE_SETDTABLESIZE)
 259         setdtablesize(lim);
 260 #endif
 261         return (0);
 262 }
 263
 264 /*
 265  * This is an strsep function that returns a null field for adjacent
 266  * separators.  This is the same as the 4.4BSD strsep, but different from the
 267  * one in the GNU libc.
 268  */
 269 static char *
 270 xstrsep(char **str, const char *delim)
 271 {
 272         char *s, *e;
 273
 274         if (!**str)
 275                 return (NULL);
 276
 277         s = *str;
 278         e = s + strcspn(s, delim);
 279
 280         if (*e != '\0')
 281                 *e++ = '\0';
 282         *str = e;
 283
 284         return (s);
 285 }
 286
 287 /*
 288  * Get the next non-null token (like GNU strsep).  Strsep() will return a
 289  * null token for two adjacent separators, so we may have to loop.
 290  */
 291 static char *
 292 strnnsep(char **stringp, char *delim)
 293 {
 294         char *tok;
 295
 296         do {
 297                 tok = xstrsep(stringp, delim);
 298         } while (tok && *tok == '\0');
 299         return (tok);
 300 }
 301
 302 static Key *
 303 keygrab_ssh1(con *c)
 304 {
 305         static Key *rsa;
 306         static Buffer msg;
 307
 308         if (rsa == NULL) {
 309                 buffer_init(&msg);
 310                 rsa = key_new(KEY_RSA1);
 311         }
 312         buffer_append(&msg, c->c_data, c->c_plen);
 313         buffer_consume(&msg, 8 - (c->c_plen & 7));      /* padding */
 314         if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
 315                 error("%s: invalid packet type", c->c_name);
 316                 buffer_clear(&msg);
 317                 return NULL;
 318         }
 319         buffer_consume(&msg, 8);                /* cookie */
 320
 321         /* server key */
 322         (void) buffer_get_int(&msg);
 323         buffer_get_bignum(&msg, rsa->rsa->e);
 324         buffer_get_bignum(&msg, rsa->rsa->n);
 325
 326         /* host key */
 327         (void) buffer_get_int(&msg);
 328         buffer_get_bignum(&msg, rsa->rsa->e);
 329         buffer_get_bignum(&msg, rsa->rsa->n);
 330
 331         buffer_clear(&msg);
 332
 333         return (rsa);
 334 }
 335
 336 static int
 337 hostjump(Key *hostkey)
 338 {
 339         kexjmp_key = hostkey;
 340         longjmp(kexjmp, 1);
 341 }
 342
 343 static int
 344 ssh2_capable(int remote_major, int remote_minor)
 345 {
 346         switch (remote_major) {
 347         case 1:
 348                 if (remote_minor == 99)
 349                         return 1;
 350                 break;
 351         case 2:
 352                 return 1;
 353         default:
 354                 break;
 355         }
 356         return 0;
 357 }
 358
 359 static Key *
 360 keygrab_ssh2(con *c)
 361 {
 362         int j;
 363
 364         packet_set_connection(c->c_fd, c->c_fd);
 365         enable_compat20();
 366         myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
 367             "ssh-dss": "ssh-rsa";
 368         c->c_kex = kex_setup(myproposal);
 369         c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
 370         c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
 371         c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
 372         c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
 373         c->c_kex->verify_host_key = hostjump;
 374
 375         if (!(j = setjmp(kexjmp))) {
 376                 nonfatal_fatal = 1;
 377                 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
 378                 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
 379                 exit(1);
 380         }
 381         nonfatal_fatal = 0;
 382         xfree(c->c_kex);
 383         c->c_kex = NULL;
 384         packet_close();
 385
 386         return j < 0? NULL : kexjmp_key;
 387 }
 388
 389 static void
 390 keyprint(con *c, Key *key)
 391 {
 392         char *host = c->c_output_name ? c->c_output_name : c->c_name;
 393
 394         if (!key)
 395                 return;
 396         if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
 397                 fatal("host_hash failed");
 398
 399         fprintf(stdout, "%s ", host);
 400         key_write(key, stdout);
 401         fputs("\n", stdout);
 402 }
 403
 404 static int
 405 tcpconnect(char *host)
 406 {
 407         struct addrinfo hints, *ai, *aitop;
 408         char strport[NI_MAXSERV];
 409         int gaierr, s = -1;
 410
 411         snprintf(strport, sizeof strport, "%d", ssh_port);
 412         memset(&hints, 0, sizeof(hints));
 413         hints.ai_family = IPv4or6;
 414         hints.ai_socktype = SOCK_STREAM;
 415         if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
 416                 fatal("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
 417         for (ai = aitop; ai; ai = ai->ai_next) {
 418                 s = socket_rdomain(ai->ai_family, ai->ai_socktype,
 419                     ai->ai_protocol, scan_rdomain);
 420                 if (s < 0) {
 421                         error("socket: %s", strerror(errno));
 422                         continue;
 423                 }
 424                 if (set_nonblock(s) == -1)
 425                         fatal("%s: set_nonblock(%d)", __func__, s);
 426                 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
 427                     errno != EINPROGRESS)
 428                         error("connect (`%s'): %s", host, strerror(errno));
 429                 else
 430                         break;
 431                 close(s);
 432                 s = -1;
 433         }
 434         freeaddrinfo(aitop);
 435         return s;
 436 }
 437
 438 static int
 439 conalloc(char *iname, char *oname, int keytype)
 440 {
 441         char *namebase, *name, *namelist;
 442         int s;
 443
 444         namebase = namelist = xstrdup(iname);
 445
 446         do {
 447                 name = xstrsep(&namelist, ",");
 448                 if (!name) {
 449                         xfree(namebase);
 450                         return (-1);
 451                 }
 452         } while ((s = tcpconnect(name)) < 0);
 453
 454         if (s >= maxfd)
 455                 fatal("conalloc: fdno %d too high", s);
 456         if (fdcon[s].c_status)
 457                 fatal("conalloc: attempt to reuse fdno %d", s);
 458
 459         fdcon[s].c_fd = s;
 460         fdcon[s].c_status = CS_CON;
 461         fdcon[s].c_namebase = namebase;
 462         fdcon[s].c_name = name;
 463         fdcon[s].c_namelist = namelist;
 464         fdcon[s].c_output_name = xstrdup(oname);
 465         fdcon[s].c_data = (char *) &fdcon[s].c_plen;
 466         fdcon[s].c_len = 4;
 467         fdcon[s].c_off = 0;
 468         fdcon[s].c_keytype = keytype;
 469         gettimeofday(&fdcon[s].c_tv, NULL);
 470         fdcon[s].c_tv.tv_sec += timeout;
 471         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 472         FD_SET(s, read_wait);
 473         ncon++;
 474         return (s);
 475 }
 476
 477 static void
 478 confree(int s)
 479 {
 480         if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
 481                 fatal("confree: attempt to free bad fdno %d", s);
 482         close(s);
 483         xfree(fdcon[s].c_namebase);
 484         xfree(fdcon[s].c_output_name);
 485         if (fdcon[s].c_status == CS_KEYS)
 486                 xfree(fdcon[s].c_data);
 487         fdcon[s].c_status = CS_UNUSED;
 488         fdcon[s].c_keytype = 0;
 489         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 490         FD_CLR(s, read_wait);
 491         ncon--;
 492 }
 493
 494 static void
 495 contouch(int s)
 496 {
 497         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 498         gettimeofday(&fdcon[s].c_tv, NULL);
 499         fdcon[s].c_tv.tv_sec += timeout;
 500         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 501 }
 502
 503 static int
 504 conrecycle(int s)
 505 {
 506         con *c = &fdcon[s];
 507         int ret;
 508
 509         ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
 510         confree(s);
 511         return (ret);
 512 }
 513
 514 static void
 515 congreet(int s)
 516 {
 517         int n = 0, remote_major = 0, remote_minor = 0;
 518         char buf[256], *cp;
 519         char remote_version[sizeof buf];
 520         size_t bufsiz;
 521         con *c = &fdcon[s];
 522
 523         for (;;) {
 524                 memset(buf, '\0', sizeof(buf));
 525                 bufsiz = sizeof(buf);
 526                 cp = buf;
 527                 while (bufsiz-- &&
 528                     (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
 529                         if (*cp == '\r')
 530                                 *cp = '\n';
 531                         cp++;
 532                 }
 533                 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
 534                         break;
 535         }
 536         if (n == 0) {
 537                 switch (errno) {
 538                 case EPIPE:
 539                         error("%s: Connection closed by remote host", c->c_name);
 540                         break;
 541                 case ECONNREFUSED:
 542                         break;
 543                 default:
 544                         error("read (%s): %s", c->c_name, strerror(errno));
 545                         break;
 546                 }
 547                 conrecycle(s);
 548                 return;
 549         }
 550         if (*cp != '\n' && *cp != '\r') {
 551                 error("%s: bad greeting", c->c_name);
 552                 confree(s);
 553                 return;
 554         }
 555         *cp = '\0';
 556         if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
 557             &remote_major, &remote_minor, remote_version) == 3)
 558                 compat_datafellows(remote_version);
 559         else
 560                 datafellows = 0;
 561         if (c->c_keytype != KT_RSA1) {
 562                 if (!ssh2_capable(remote_major, remote_minor)) {
 563                         debug("%s doesn't support ssh2", c->c_name);
 564                         confree(s);
 565                         return;
 566                 }
 567         } else if (remote_major != 1) {
 568                 debug("%s doesn't support ssh1", c->c_name);
 569                 confree(s);
 570                 return;
 571         }
 572         fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
 573         n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
 574             c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
 575             c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
 576         if (n < 0 || (size_t)n >= sizeof(buf)) {
 577                 error("snprintf: buffer too small");
 578                 confree(s);
 579                 return;
 580         }
 581         if (atomicio(vwrite, s, buf, n) != (size_t)n) {
 582                 error("write (%s): %s", c->c_name, strerror(errno));
 583                 confree(s);
 584                 return;
 585         }
 586         if (c->c_keytype != KT_RSA1) {
 587                 keyprint(c, keygrab_ssh2(c));
 588                 confree(s);
 589                 return;
 590         }
 591         c->c_status = CS_SIZE;
 592         contouch(s);
 593 }
 594
 595 static void
 596 conread(int s)
 597 {
 598         con *c = &fdcon[s];
 599         size_t n;
 600
 601         if (c->c_status == CS_CON) {
 602                 congreet(s);
 603                 return;
 604         }
 605         n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
 606         if (n == 0) {
 607                 error("read (%s): %s", c->c_name, strerror(errno));
 608                 confree(s);
 609                 return;
 610         }
 611         c->c_off += n;
 612
 613         if (c->c_off == c->c_len)
 614                 switch (c->c_status) {
 615                 case CS_SIZE:
 616                         c->c_plen = htonl(c->c_plen);
 617                         c->c_len = c->c_plen + 8 - (c->c_plen & 7);
 618                         c->c_off = 0;
 619                         c->c_data = xmalloc(c->c_len);
 620                         c->c_status = CS_KEYS;
 621                         break;
 622                 case CS_KEYS:
 623                         keyprint(c, keygrab_ssh1(c));
 624                         confree(s);
 625                         return;
 626                 default:
 627                         fatal("conread: invalid status %d", c->c_status);
 628                         break;
 629                 }
 630
 631         contouch(s);
 632 }
 633
 634 static void
 635 conloop(void)
 636 {
 637         struct timeval seltime, now;
 638         fd_set *r, *e;
 639         con *c;
 640         int i;
 641
 642         gettimeofday(&now, NULL);
 643         c = TAILQ_FIRST(&tq);
 644
 645         if (c && (c->c_tv.tv_sec > now.tv_sec ||
 646             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
 647                 seltime = c->c_tv;
 648                 seltime.tv_sec -= now.tv_sec;
 649                 seltime.tv_usec -= now.tv_usec;
 650                 if (seltime.tv_usec < 0) {
 651                         seltime.tv_usec += 1000000;
 652                         seltime.tv_sec--;
 653                 }
 654         } else
 655                 seltime.tv_sec = seltime.tv_usec = 0;
 656
 657         r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 658         e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 659         memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
 660         memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
 661
 662         while (select(maxfd, r, NULL, e, &seltime) == -1 &&
 663             (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
 664                 ;
 665
 666         for (i = 0; i < maxfd; i++) {
 667                 if (FD_ISSET(i, e)) {
 668                         error("%s: exception!", fdcon[i].c_name);
 669                         confree(i);
 670                 } else if (FD_ISSET(i, r))
 671                         conread(i);
 672         }
 673         xfree(r);
 674         xfree(e);
 675
 676         c = TAILQ_FIRST(&tq);
 677         while (c && (c->c_tv.tv_sec < now.tv_sec ||
 678             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
 679                 int s = c->c_fd;
 680
 681                 c = TAILQ_NEXT(c, c_link);
 682                 conrecycle(s);
 683         }
 684 }
 685
 686 static void
 687 do_host(char *host)
 688 {
 689         char *name = strnnsep(&host, " \t\n");
 690         int j;
 691
 692         if (name == NULL)
 693                 return;
 694         for (j = KT_RSA1; j <= KT_RSA; j *= 2) {
 695                 if (get_keytypes & j) {
 696                         while (ncon >= MAXCON)
 697                                 conloop();
 698                         conalloc(name, *host ? host : name, j);
 699                 }
 700         }
 701 }
 702
 703 void
 704 fatal(const char *fmt,...)
 705 {
 706         va_list args;
 707
 708         va_start(args, fmt);
 709         do_log(SYSLOG_LEVEL_FATAL, fmt, args);
 710         va_end(args);
 711         if (nonfatal_fatal)
 712                 longjmp(kexjmp, -1);
 713         else
 714                 exit(255);
 715 }
 716
 717 static void
 718 usage(void)
 719 {
 720         fprintf(stderr,
 721             "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
 722             "\t\t   [-V rdomain] [host | addrlist namelist] ...\n",
 723             __progname);
 724         exit(1);
 725 }
 726
 727 int
 728 main(int argc, char **argv)
 729 {
 730         int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
 731         int opt, fopt_count = 0;
 732         char *tname;
 733
 734         extern int optind;
 735         extern char *optarg;
 736
 737         __progname = ssh_get_progname(argv[0]);
 738         init_rng();
 739         seed_rng();
 740         TAILQ_INIT(&tq);
 741
 742         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 743         sanitise_stdfd();
 744
 745         if (argc <= 1)
 746                 usage();
 747
 748         while ((opt = getopt(argc, argv, "Hv46p:T:t:f:V:")) != -1) {
 749                 switch (opt) {
 750                 case 'H':
 751                         hash_hosts = 1;
 752                         break;
 753                 case 'p':
 754                         ssh_port = a2port(optarg);
 755                         if (ssh_port <= 0) {
 756                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 757                                 exit(1);
 758                         }
 759                         break;
 760                 case 'T':
 761                         timeout = convtime(optarg);
 762                         if (timeout == -1 || timeout == 0) {
 763                                 fprintf(stderr, "Bad timeout '%s'\n", optarg);
 764                                 usage();
 765                         }
 766                         break;
 767                 case 'v':
 768                         if (!debug_flag) {
 769                                 debug_flag = 1;
 770                                 log_level = SYSLOG_LEVEL_DEBUG1;
 771                         }
 772                         else if (log_level < SYSLOG_LEVEL_DEBUG3)
 773                                 log_level++;
 774                         else
 775                                 fatal("Too high debugging level.");
 776                         break;
 777                 case 'f':
 778                         if (strcmp(optarg, "-") == 0)
 779                                 optarg = NULL;
 780                         argv[fopt_count++] = optarg;
 781                         break;
 782                 case 't':
 783                         get_keytypes = 0;
 784                         tname = strtok(optarg, ",");
 785                         while (tname) {
 786                                 int type = key_type_from_name(tname);
 787                                 switch (type) {
 788                                 case KEY_RSA1:
 789                                         get_keytypes |= KT_RSA1;
 790                                         break;
 791                                 case KEY_DSA:
 792                                         get_keytypes |= KT_DSA;
 793                                         break;
 794                                 case KEY_RSA:
 795                                         get_keytypes |= KT_RSA;
 796                                         break;
 797                                 case KEY_UNSPEC:
 798                                         fatal("unknown key type %s", tname);
 799                                 }
 800                                 tname = strtok(NULL, ",");
 801                         }
 802                         break;
 803                 case '4':
 804                         IPv4or6 = AF_INET;
 805                         break;
 806                 case '6':
 807                         IPv4or6 = AF_INET6;
 808                         break;
 809                 case 'V':
 810                         scan_rdomain = a2port(optarg);
 811                         if (scan_rdomain < 0)
 812                                 scan_rdomain = -1;
 813                         break;
 814                 case '?':
 815                 default:
 816                         usage();
 817                 }
 818         }
 819         if (optind == argc && !fopt_count)
 820                 usage();
 821
 822         log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
 823
 824         maxfd = fdlim_get(1);
 825         if (maxfd < 0)
 826                 fatal("%s: fdlim_get: bad value", __progname);
 827         if (maxfd > MAXMAXFD)
 828                 maxfd = MAXMAXFD;
 829         if (MAXCON <= 0)
 830                 fatal("%s: not enough file descriptors", __progname);
 831         if (maxfd > fdlim_get(0))
 832                 fdlim_set(maxfd);
 833         fdcon = xcalloc(maxfd, sizeof(con));
 834
 835         read_wait_nfdset = howmany(maxfd, NFDBITS);
 836         read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 837
 838         if (fopt_count) {
 839                 Linebuf *lb;
 840                 char *line;
 841                 int j;
 842
 843                 for (j = 0; j < fopt_count; j++) {
 844                         lb = Linebuf_alloc(argv[j], error);
 845                         if (!lb)
 846                                 continue;
 847                         while ((line = Linebuf_getline(lb)) != NULL)
 848                                 do_host(line);
 849                         Linebuf_free(lb);
 850                 }
 851         }
 852
 853         while (optind < argc)
 854                 do_host(argv[optind++]);
 855
 856         while (ncon > 0)
 857                 conloop();
 858
 859         return (0);
 860 }