crypto/openssh/ssh-keyscan.c

   1 /* $OpenBSD: ssh-keyscan.c,v 1.85 2011/03/15 10:36:02 okan 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 #define KT_ECDSA        8
  59
  60 int get_keytypes = KT_RSA;      /* Get only RSA keys by default */
  61
  62 int hash_hosts = 0;             /* Hash hostname on output */
  63
  64 #define MAXMAXFD 256
  65
  66 /* The number of seconds after which to give up on a TCP connection */
  67 int timeout = 5;
  68
  69 int maxfd;
  70 #define MAXCON (maxfd - 10)
  71
  72 extern char *__progname;
  73 fd_set *read_wait;
  74 size_t read_wait_nfdset;
  75 int ncon;
  76 int nonfatal_fatal = 0;
  77 jmp_buf kexjmp;
  78 Key *kexjmp_key;
  79
  80 /*
  81  * Keep a connection structure for each file descriptor.  The state
  82  * associated with file descriptor n is held in fdcon[n].
  83  */
  84 typedef struct Connection {
  85         u_char c_status;        /* State of connection on this file desc. */
  86 #define CS_UNUSED 0             /* File descriptor unused */
  87 #define CS_CON 1                /* Waiting to connect/read greeting */
  88 #define CS_SIZE 2               /* Waiting to read initial packet size */
  89 #define CS_KEYS 3               /* Waiting to read public key packet */
  90         int c_fd;               /* Quick lookup: c->c_fd == c - fdcon */
  91         int c_plen;             /* Packet length field for ssh packet */
  92         int c_len;              /* Total bytes which must be read. */
  93         int c_off;              /* Length of data read so far. */
  94         int c_keytype;          /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
  95         char *c_namebase;       /* Address to free for c_name and c_namelist */
  96         char *c_name;           /* Hostname of connection for errors */
  97         char *c_namelist;       /* Pointer to other possible addresses */
  98         char *c_output_name;    /* Hostname of connection for output */
  99         char *c_data;           /* Data read from this fd */
 100         Kex *c_kex;             /* The key-exchange struct for ssh2 */
 101         struct timeval c_tv;    /* Time at which connection gets aborted */
 102         TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
 103 } con;
 104
 105 TAILQ_HEAD(conlist, Connection) tq;     /* Timeout Queue */
 106 con *fdcon;
 107
 108 static int
 109 fdlim_get(int hard)
 110 {
 111 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
 112         struct rlimit rlfd;
 113
 114         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 115                 return (-1);
 116         if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
 117                 return SSH_SYSFDMAX;
 118         else
 119                 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
 120 #else
 121         return SSH_SYSFDMAX;
 122 #endif
 123 }
 124
 125 static int
 126 fdlim_set(int lim)
 127 {
 128 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 129         struct rlimit rlfd;
 130 #endif
 131
 132         if (lim <= 0)
 133                 return (-1);
 134 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 135         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 136                 return (-1);
 137         rlfd.rlim_cur = lim;
 138         if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 139                 return (-1);
 140 #elif defined (HAVE_SETDTABLESIZE)
 141         setdtablesize(lim);
 142 #endif
 143         return (0);
 144 }
 145
 146 /*
 147  * This is an strsep function that returns a null field for adjacent
 148  * separators.  This is the same as the 4.4BSD strsep, but different from the
 149  * one in the GNU libc.
 150  */
 151 static char *
 152 xstrsep(char **str, const char *delim)
 153 {
 154         char *s, *e;
 155
 156         if (!**str)
 157                 return (NULL);
 158
 159         s = *str;
 160         e = s + strcspn(s, delim);
 161
 162         if (*e != '\0')
 163                 *e++ = '\0';
 164         *str = e;
 165
 166         return (s);
 167 }
 168
 169 /*
 170  * Get the next non-null token (like GNU strsep).  Strsep() will return a
 171  * null token for two adjacent separators, so we may have to loop.
 172  */
 173 static char *
 174 strnnsep(char **stringp, char *delim)
 175 {
 176         char *tok;
 177
 178         do {
 179                 tok = xstrsep(stringp, delim);
 180         } while (tok && *tok == '\0');
 181         return (tok);
 182 }
 183
 184 static Key *
 185 keygrab_ssh1(con *c)
 186 {
 187         static Key *rsa;
 188         static Buffer msg;
 189
 190         if (rsa == NULL) {
 191                 buffer_init(&msg);
 192                 rsa = key_new(KEY_RSA1);
 193         }
 194         buffer_append(&msg, c->c_data, c->c_plen);
 195         buffer_consume(&msg, 8 - (c->c_plen & 7));      /* padding */
 196         if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
 197                 error("%s: invalid packet type", c->c_name);
 198                 buffer_clear(&msg);
 199                 return NULL;
 200         }
 201         buffer_consume(&msg, 8);                /* cookie */
 202
 203         /* server key */
 204         (void) buffer_get_int(&msg);
 205         buffer_get_bignum(&msg, rsa->rsa->e);
 206         buffer_get_bignum(&msg, rsa->rsa->n);
 207
 208         /* host key */
 209         (void) buffer_get_int(&msg);
 210         buffer_get_bignum(&msg, rsa->rsa->e);
 211         buffer_get_bignum(&msg, rsa->rsa->n);
 212
 213         buffer_clear(&msg);
 214
 215         return (rsa);
 216 }
 217
 218 static int
 219 hostjump(Key *hostkey)
 220 {
 221         kexjmp_key = hostkey;
 222         longjmp(kexjmp, 1);
 223 }
 224
 225 static int
 226 ssh2_capable(int remote_major, int remote_minor)
 227 {
 228         switch (remote_major) {
 229         case 1:
 230                 if (remote_minor == 99)
 231                         return 1;
 232                 break;
 233         case 2:
 234                 return 1;
 235         default:
 236                 break;
 237         }
 238         return 0;
 239 }
 240
 241 static Key *
 242 keygrab_ssh2(con *c)
 243 {
 244         int j;
 245
 246         packet_set_connection(c->c_fd, c->c_fd);
 247         enable_compat20();
 248         myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = c->c_keytype == KT_DSA?
 249             "ssh-dss" : (c->c_keytype == KT_RSA ? "ssh-rsa" :
 250             "ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521");
 251         c->c_kex = kex_setup(myproposal);
 252         c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
 253         c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
 254         c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
 255         c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
 256         c->c_kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
 257         c->c_kex->verify_host_key = hostjump;
 258
 259         if (!(j = setjmp(kexjmp))) {
 260                 nonfatal_fatal = 1;
 261                 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
 262                 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
 263                 exit(1);
 264         }
 265         nonfatal_fatal = 0;
 266         xfree(c->c_kex);
 267         c->c_kex = NULL;
 268         packet_close();
 269
 270         return j < 0? NULL : kexjmp_key;
 271 }
 272
 273 static void
 274 keyprint(con *c, Key *key)
 275 {
 276         char *host = c->c_output_name ? c->c_output_name : c->c_name;
 277
 278         if (!key)
 279                 return;
 280         if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
 281                 fatal("host_hash failed");
 282
 283         fprintf(stdout, "%s ", host);
 284         key_write(key, stdout);
 285         fputs("\n", stdout);
 286 }
 287
 288 static int
 289 tcpconnect(char *host)
 290 {
 291         struct addrinfo hints, *ai, *aitop;
 292         char strport[NI_MAXSERV];
 293         int gaierr, s = -1;
 294
 295         snprintf(strport, sizeof strport, "%d", ssh_port);
 296         memset(&hints, 0, sizeof(hints));
 297         hints.ai_family = IPv4or6;
 298         hints.ai_socktype = SOCK_STREAM;
 299         if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
 300                 fatal("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
 301         for (ai = aitop; ai; ai = ai->ai_next) {
 302                 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 303                 if (s < 0) {
 304                         error("socket: %s", strerror(errno));
 305                         continue;
 306                 }
 307                 if (set_nonblock(s) == -1)
 308                         fatal("%s: set_nonblock(%d)", __func__, s);
 309                 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
 310                     errno != EINPROGRESS)
 311                         error("connect (`%s'): %s", host, strerror(errno));
 312                 else
 313                         break;
 314                 close(s);
 315                 s = -1;
 316         }
 317         freeaddrinfo(aitop);
 318         return s;
 319 }
 320
 321 static int
 322 conalloc(char *iname, char *oname, int keytype)
 323 {
 324         char *namebase, *name, *namelist;
 325         int s;
 326
 327         namebase = namelist = xstrdup(iname);
 328
 329         do {
 330                 name = xstrsep(&namelist, ",");
 331                 if (!name) {
 332                         xfree(namebase);
 333                         return (-1);
 334                 }
 335         } while ((s = tcpconnect(name)) < 0);
 336
 337         if (s >= maxfd)
 338                 fatal("conalloc: fdno %d too high", s);
 339         if (fdcon[s].c_status)
 340                 fatal("conalloc: attempt to reuse fdno %d", s);
 341
 342         fdcon[s].c_fd = s;
 343         fdcon[s].c_status = CS_CON;
 344         fdcon[s].c_namebase = namebase;
 345         fdcon[s].c_name = name;
 346         fdcon[s].c_namelist = namelist;
 347         fdcon[s].c_output_name = xstrdup(oname);
 348         fdcon[s].c_data = (char *) &fdcon[s].c_plen;
 349         fdcon[s].c_len = 4;
 350         fdcon[s].c_off = 0;
 351         fdcon[s].c_keytype = keytype;
 352         gettimeofday(&fdcon[s].c_tv, NULL);
 353         fdcon[s].c_tv.tv_sec += timeout;
 354         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 355         FD_SET(s, read_wait);
 356         ncon++;
 357         return (s);
 358 }
 359
 360 static void
 361 confree(int s)
 362 {
 363         if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
 364                 fatal("confree: attempt to free bad fdno %d", s);
 365         close(s);
 366         xfree(fdcon[s].c_namebase);
 367         xfree(fdcon[s].c_output_name);
 368         if (fdcon[s].c_status == CS_KEYS)
 369                 xfree(fdcon[s].c_data);
 370         fdcon[s].c_status = CS_UNUSED;
 371         fdcon[s].c_keytype = 0;
 372         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 373         FD_CLR(s, read_wait);
 374         ncon--;
 375 }
 376
 377 static void
 378 contouch(int s)
 379 {
 380         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 381         gettimeofday(&fdcon[s].c_tv, NULL);
 382         fdcon[s].c_tv.tv_sec += timeout;
 383         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 384 }
 385
 386 static int
 387 conrecycle(int s)
 388 {
 389         con *c = &fdcon[s];
 390         int ret;
 391
 392         ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
 393         confree(s);
 394         return (ret);
 395 }
 396
 397 static void
 398 congreet(int s)
 399 {
 400         int n = 0, remote_major = 0, remote_minor = 0;
 401         char buf[256], *cp;
 402         char remote_version[sizeof buf];
 403         size_t bufsiz;
 404         con *c = &fdcon[s];
 405
 406         for (;;) {
 407                 memset(buf, '\0', sizeof(buf));
 408                 bufsiz = sizeof(buf);
 409                 cp = buf;
 410                 while (bufsiz-- &&
 411                     (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
 412                         if (*cp == '\r')
 413                                 *cp = '\n';
 414                         cp++;
 415                 }
 416                 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
 417                         break;
 418         }
 419         if (n == 0) {
 420                 switch (errno) {
 421                 case EPIPE:
 422                         error("%s: Connection closed by remote host", c->c_name);
 423                         break;
 424                 case ECONNREFUSED:
 425                         break;
 426                 default:
 427                         error("read (%s): %s", c->c_name, strerror(errno));
 428                         break;
 429                 }
 430                 conrecycle(s);
 431                 return;
 432         }
 433         if (*cp != '\n' && *cp != '\r') {
 434                 error("%s: bad greeting", c->c_name);
 435                 confree(s);
 436                 return;
 437         }
 438         *cp = '\0';
 439         if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
 440             &remote_major, &remote_minor, remote_version) == 3)
 441                 compat_datafellows(remote_version);
 442         else
 443                 datafellows = 0;
 444         if (c->c_keytype != KT_RSA1) {
 445                 if (!ssh2_capable(remote_major, remote_minor)) {
 446                         debug("%s doesn't support ssh2", c->c_name);
 447                         confree(s);
 448                         return;
 449                 }
 450         } else if (remote_major != 1) {
 451                 debug("%s doesn't support ssh1", c->c_name);
 452                 confree(s);
 453                 return;
 454         }
 455         fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
 456         n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
 457             c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
 458             c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
 459         if (n < 0 || (size_t)n >= sizeof(buf)) {
 460                 error("snprintf: buffer too small");
 461                 confree(s);
 462                 return;
 463         }
 464         if (atomicio(vwrite, s, buf, n) != (size_t)n) {
 465                 error("write (%s): %s", c->c_name, strerror(errno));
 466                 confree(s);
 467                 return;
 468         }
 469         if (c->c_keytype != KT_RSA1) {
 470                 keyprint(c, keygrab_ssh2(c));
 471                 confree(s);
 472                 return;
 473         }
 474         c->c_status = CS_SIZE;
 475         contouch(s);
 476 }
 477
 478 static void
 479 conread(int s)
 480 {
 481         con *c = &fdcon[s];
 482         size_t n;
 483
 484         if (c->c_status == CS_CON) {
 485                 congreet(s);
 486                 return;
 487         }
 488         n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
 489         if (n == 0) {
 490                 error("read (%s): %s", c->c_name, strerror(errno));
 491                 confree(s);
 492                 return;
 493         }
 494         c->c_off += n;
 495
 496         if (c->c_off == c->c_len)
 497                 switch (c->c_status) {
 498                 case CS_SIZE:
 499                         c->c_plen = htonl(c->c_plen);
 500                         c->c_len = c->c_plen + 8 - (c->c_plen & 7);
 501                         c->c_off = 0;
 502                         c->c_data = xmalloc(c->c_len);
 503                         c->c_status = CS_KEYS;
 504                         break;
 505                 case CS_KEYS:
 506                         keyprint(c, keygrab_ssh1(c));
 507                         confree(s);
 508                         return;
 509                 default:
 510                         fatal("conread: invalid status %d", c->c_status);
 511                         break;
 512                 }
 513
 514         contouch(s);
 515 }
 516
 517 static void
 518 conloop(void)
 519 {
 520         struct timeval seltime, now;
 521         fd_set *r, *e;
 522         con *c;
 523         int i;
 524
 525         gettimeofday(&now, NULL);
 526         c = TAILQ_FIRST(&tq);
 527
 528         if (c && (c->c_tv.tv_sec > now.tv_sec ||
 529             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
 530                 seltime = c->c_tv;
 531                 seltime.tv_sec -= now.tv_sec;
 532                 seltime.tv_usec -= now.tv_usec;
 533                 if (seltime.tv_usec < 0) {
 534                         seltime.tv_usec += 1000000;
 535                         seltime.tv_sec--;
 536                 }
 537         } else
 538                 timerclear(&seltime);
 539
 540         r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 541         e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 542         memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
 543         memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
 544
 545         while (select(maxfd, r, NULL, e, &seltime) == -1 &&
 546             (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
 547                 ;
 548
 549         for (i = 0; i < maxfd; i++) {
 550                 if (FD_ISSET(i, e)) {
 551                         error("%s: exception!", fdcon[i].c_name);
 552                         confree(i);
 553                 } else if (FD_ISSET(i, r))
 554                         conread(i);
 555         }
 556         xfree(r);
 557         xfree(e);
 558
 559         c = TAILQ_FIRST(&tq);
 560         while (c && (c->c_tv.tv_sec < now.tv_sec ||
 561             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
 562                 int s = c->c_fd;
 563
 564                 c = TAILQ_NEXT(c, c_link);
 565                 conrecycle(s);
 566         }
 567 }
 568
 569 static void
 570 do_host(char *host)
 571 {
 572         char *name = strnnsep(&host, " \t\n");
 573         int j;
 574
 575         if (name == NULL)
 576                 return;
 577         for (j = KT_RSA1; j <= KT_ECDSA; j *= 2) {
 578                 if (get_keytypes & j) {
 579                         while (ncon >= MAXCON)
 580                                 conloop();
 581                         conalloc(name, *host ? host : name, j);
 582                 }
 583         }
 584 }
 585
 586 void
 587 fatal(const char *fmt,...)
 588 {
 589         va_list args;
 590
 591         va_start(args, fmt);
 592         do_log(SYSLOG_LEVEL_FATAL, fmt, args);
 593         va_end(args);
 594         if (nonfatal_fatal)
 595                 longjmp(kexjmp, -1);
 596         else
 597                 exit(255);
 598 }
 599
 600 static void
 601 usage(void)
 602 {
 603         fprintf(stderr,
 604             "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
 605             "\t\t   [host | addrlist namelist] ...\n",
 606             __progname);
 607         exit(1);
 608 }
 609
 610 int
 611 main(int argc, char **argv)
 612 {
 613         int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
 614         int opt, fopt_count = 0, j;
 615         char *tname, *cp, line[NI_MAXHOST];
 616         FILE *fp;
 617         u_long linenum;
 618
 619         extern int optind;
 620         extern char *optarg;
 621
 622         __progname = ssh_get_progname(argv[0]);
 623         seed_rng();
 624         TAILQ_INIT(&tq);
 625
 626         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 627         sanitise_stdfd();
 628
 629         if (argc <= 1)
 630                 usage();
 631
 632         while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
 633                 switch (opt) {
 634                 case 'H':
 635                         hash_hosts = 1;
 636                         break;
 637                 case 'p':
 638                         ssh_port = a2port(optarg);
 639                         if (ssh_port <= 0) {
 640                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 641                                 exit(1);
 642                         }
 643                         break;
 644                 case 'T':
 645                         timeout = convtime(optarg);
 646                         if (timeout == -1 || timeout == 0) {
 647                                 fprintf(stderr, "Bad timeout '%s'\n", optarg);
 648                                 usage();
 649                         }
 650                         break;
 651                 case 'v':
 652                         if (!debug_flag) {
 653                                 debug_flag = 1;
 654                                 log_level = SYSLOG_LEVEL_DEBUG1;
 655                         }
 656                         else if (log_level < SYSLOG_LEVEL_DEBUG3)
 657                                 log_level++;
 658                         else
 659                                 fatal("Too high debugging level.");
 660                         break;
 661                 case 'f':
 662                         if (strcmp(optarg, "-") == 0)
 663                                 optarg = NULL;
 664                         argv[fopt_count++] = optarg;
 665                         break;
 666                 case 't':
 667                         get_keytypes = 0;
 668                         tname = strtok(optarg, ",");
 669                         while (tname) {
 670                                 int type = key_type_from_name(tname);
 671                                 switch (type) {
 672                                 case KEY_RSA1:
 673                                         get_keytypes |= KT_RSA1;
 674                                         break;
 675                                 case KEY_DSA:
 676                                         get_keytypes |= KT_DSA;
 677                                         break;
 678                                 case KEY_ECDSA:
 679                                         get_keytypes |= KT_ECDSA;
 680                                         break;
 681                                 case KEY_RSA:
 682                                         get_keytypes |= KT_RSA;
 683                                         break;
 684                                 case KEY_UNSPEC:
 685                                         fatal("unknown key type %s", tname);
 686                                 }
 687                                 tname = strtok(NULL, ",");
 688                         }
 689                         break;
 690                 case '4':
 691                         IPv4or6 = AF_INET;
 692                         break;
 693                 case '6':
 694                         IPv4or6 = AF_INET6;
 695                         break;
 696                 case '?':
 697                 default:
 698                         usage();
 699                 }
 700         }
 701         if (optind == argc && !fopt_count)
 702                 usage();
 703
 704         log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
 705
 706         maxfd = fdlim_get(1);
 707         if (maxfd < 0)
 708                 fatal("%s: fdlim_get: bad value", __progname);
 709         if (maxfd > MAXMAXFD)
 710                 maxfd = MAXMAXFD;
 711         if (MAXCON <= 0)
 712                 fatal("%s: not enough file descriptors", __progname);
 713         if (maxfd > fdlim_get(0))
 714                 fdlim_set(maxfd);
 715         fdcon = xcalloc(maxfd, sizeof(con));
 716
 717         read_wait_nfdset = howmany(maxfd, NFDBITS);
 718         read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 719
 720         for (j = 0; j < fopt_count; j++) {
 721                 if (argv[j] == NULL)
 722                         fp = stdin;
 723                 else if ((fp = fopen(argv[j], "r")) == NULL)
 724                         fatal("%s: %s: %s", __progname, argv[j],
 725                             strerror(errno));
 726                 linenum = 0;
 727
 728                 while (read_keyfile_line(fp,
 729                     argv[j] == NULL ? "(stdin)" : argv[j], line, sizeof(line),
 730                     &linenum) != -1) {
 731                         /* Chomp off trailing whitespace and comments */
 732                         if ((cp = strchr(line, '#')) == NULL)
 733                                 cp = line + strlen(line) - 1;
 734                         while (cp >= line) {
 735                                 if (*cp == ' ' || *cp == '\t' ||
 736                                     *cp == '\n' || *cp == '#')
 737                                         *cp-- = '\0';
 738                                 else
 739                                         break;
 740                         }
 741
 742                         /* Skip empty lines */
 743                         if (*line == '\0')
 744                                 continue;
 745
 746                         do_host(line);
 747                 }
 748
 749                 if (ferror(fp))
 750                         fatal("%s: %s: %s", __progname, argv[j],
 751                             strerror(errno));
 752
 753                 fclose(fp);
 754         }
 755
 756         while (optind < argc)
 757                 do_host(argv[optind++]);
 758
 759         while (ncon > 0)
 760                 conloop();
 761
 762         return (0);
 763 }