crypto/openssh/ssh-keyscan.c

   1 /* $OpenBSD: ssh-keyscan.c,v 1.92 2014/04/29 18:01:49 markus 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 #define KT_ED25519      16
  60
  61 int get_keytypes = KT_RSA|KT_ECDSA|KT_ED25519;
  62
  63 int hash_hosts = 0;             /* Hash hostname on output */
  64
  65 #define MAXMAXFD 256
  66
  67 /* The number of seconds after which to give up on a TCP connection */
  68 int timeout = 5;
  69
  70 int maxfd;
  71 #define MAXCON (maxfd - 10)
  72
  73 extern char *__progname;
  74 fd_set *read_wait;
  75 size_t read_wait_nfdset;
  76 int ncon;
  77 int nonfatal_fatal = 0;
  78 jmp_buf kexjmp;
  79 Key *kexjmp_key;
  80
  81 /*
  82  * Keep a connection structure for each file descriptor.  The state
  83  * associated with file descriptor n is held in fdcon[n].
  84  */
  85 typedef struct Connection {
  86         u_char c_status;        /* State of connection on this file desc. */
  87 #define CS_UNUSED 0             /* File descriptor unused */
  88 #define CS_CON 1                /* Waiting to connect/read greeting */
  89 #define CS_SIZE 2               /* Waiting to read initial packet size */
  90 #define CS_KEYS 3               /* Waiting to read public key packet */
  91         int c_fd;               /* Quick lookup: c->c_fd == c - fdcon */
  92         int c_plen;             /* Packet length field for ssh packet */
  93         int c_len;              /* Total bytes which must be read. */
  94         int c_off;              /* Length of data read so far. */
  95         int c_keytype;          /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
  96         char *c_namebase;       /* Address to free for c_name and c_namelist */
  97         char *c_name;           /* Hostname of connection for errors */
  98         char *c_namelist;       /* Pointer to other possible addresses */
  99         char *c_output_name;    /* Hostname of connection for output */
 100         char *c_data;           /* Data read from this fd */
 101         Kex *c_kex;             /* The key-exchange struct for ssh2 */
 102         struct timeval c_tv;    /* Time at which connection gets aborted */
 103         TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
 104 } con;
 105
 106 TAILQ_HEAD(conlist, Connection) tq;     /* Timeout Queue */
 107 con *fdcon;
 108
 109 static int
 110 fdlim_get(int hard)
 111 {
 112 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
 113         struct rlimit rlfd;
 114
 115         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 116                 return (-1);
 117         if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
 118                 return SSH_SYSFDMAX;
 119         else
 120                 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
 121 #else
 122         return SSH_SYSFDMAX;
 123 #endif
 124 }
 125
 126 static int
 127 fdlim_set(int lim)
 128 {
 129 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 130         struct rlimit rlfd;
 131 #endif
 132
 133         if (lim <= 0)
 134                 return (-1);
 135 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 136         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 137                 return (-1);
 138         rlfd.rlim_cur = lim;
 139         if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 140                 return (-1);
 141 #elif defined (HAVE_SETDTABLESIZE)
 142         setdtablesize(lim);
 143 #endif
 144         return (0);
 145 }
 146
 147 /*
 148  * This is an strsep function that returns a null field for adjacent
 149  * separators.  This is the same as the 4.4BSD strsep, but different from the
 150  * one in the GNU libc.
 151  */
 152 static char *
 153 xstrsep(char **str, const char *delim)
 154 {
 155         char *s, *e;
 156
 157         if (!**str)
 158                 return (NULL);
 159
 160         s = *str;
 161         e = s + strcspn(s, delim);
 162
 163         if (*e != '\0')
 164                 *e++ = '\0';
 165         *str = e;
 166
 167         return (s);
 168 }
 169
 170 /*
 171  * Get the next non-null token (like GNU strsep).  Strsep() will return a
 172  * null token for two adjacent separators, so we may have to loop.
 173  */
 174 static char *
 175 strnnsep(char **stringp, char *delim)
 176 {
 177         char *tok;
 178
 179         do {
 180                 tok = xstrsep(stringp, delim);
 181         } while (tok && *tok == '\0');
 182         return (tok);
 183 }
 184
 185 #ifdef WITH_SSH1
 186 static Key *
 187 keygrab_ssh1(con *c)
 188 {
 189         static Key *rsa;
 190         static Buffer msg;
 191
 192         if (rsa == NULL) {
 193                 buffer_init(&msg);
 194                 rsa = key_new(KEY_RSA1);
 195         }
 196         buffer_append(&msg, c->c_data, c->c_plen);
 197         buffer_consume(&msg, 8 - (c->c_plen & 7));      /* padding */
 198         if (buffer_get_char(&msg) != (int) SSH_SMSG_PUBLIC_KEY) {
 199                 error("%s: invalid packet type", c->c_name);
 200                 buffer_clear(&msg);
 201                 return NULL;
 202         }
 203         buffer_consume(&msg, 8);                /* cookie */
 204
 205         /* server key */
 206         (void) buffer_get_int(&msg);
 207         buffer_get_bignum(&msg, rsa->rsa->e);
 208         buffer_get_bignum(&msg, rsa->rsa->n);
 209
 210         /* host key */
 211         (void) buffer_get_int(&msg);
 212         buffer_get_bignum(&msg, rsa->rsa->e);
 213         buffer_get_bignum(&msg, rsa->rsa->n);
 214
 215         buffer_clear(&msg);
 216
 217         return (rsa);
 218 }
 219 #endif
 220
 221 static int
 222 hostjump(Key *hostkey)
 223 {
 224         kexjmp_key = hostkey;
 225         longjmp(kexjmp, 1);
 226 }
 227
 228 static int
 229 ssh2_capable(int remote_major, int remote_minor)
 230 {
 231         switch (remote_major) {
 232         case 1:
 233                 if (remote_minor == 99)
 234                         return 1;
 235                 break;
 236         case 2:
 237                 return 1;
 238         default:
 239                 break;
 240         }
 241         return 0;
 242 }
 243
 244 static Key *
 245 keygrab_ssh2(con *c)
 246 {
 247         char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
 248         int j;
 249
 250         packet_set_connection(c->c_fd, c->c_fd);
 251         enable_compat20();
 252         myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] =
 253             c->c_keytype == KT_DSA ?  "ssh-dss" :
 254             (c->c_keytype == KT_RSA ? "ssh-rsa" :
 255             (c->c_keytype == KT_ED25519 ? "ssh-ed25519" :
 256             "ecdsa-sha2-nistp256,ecdsa-sha2-nistp384,ecdsa-sha2-nistp521"));
 257         c->c_kex = kex_setup(myproposal);
 258 #ifdef WITH_OPENSSL
 259         c->c_kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
 260         c->c_kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
 261         c->c_kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
 262         c->c_kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
 263         c->c_kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
 264 #endif
 265         c->c_kex->kex[KEX_C25519_SHA256] = kexc25519_client;
 266         c->c_kex->verify_host_key = hostjump;
 267
 268         if (!(j = setjmp(kexjmp))) {
 269                 nonfatal_fatal = 1;
 270                 dispatch_run(DISPATCH_BLOCK, &c->c_kex->done, c->c_kex);
 271                 fprintf(stderr, "Impossible! dispatch_run() returned!\n");
 272                 exit(1);
 273         }
 274         nonfatal_fatal = 0;
 275         free(c->c_kex);
 276         c->c_kex = NULL;
 277         packet_close();
 278
 279         return j < 0? NULL : kexjmp_key;
 280 }
 281
 282 static void
 283 keyprint(con *c, Key *key)
 284 {
 285         char *host = c->c_output_name ? c->c_output_name : c->c_name;
 286
 287         if (!key)
 288                 return;
 289         if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
 290                 fatal("host_hash failed");
 291
 292         fprintf(stdout, "%s ", host);
 293         key_write(key, stdout);
 294         fputs("\n", stdout);
 295 }
 296
 297 static int
 298 tcpconnect(char *host)
 299 {
 300         struct addrinfo hints, *ai, *aitop;
 301         char strport[NI_MAXSERV];
 302         int gaierr, s = -1;
 303
 304         snprintf(strport, sizeof strport, "%d", ssh_port);
 305         memset(&hints, 0, sizeof(hints));
 306         hints.ai_family = IPv4or6;
 307         hints.ai_socktype = SOCK_STREAM;
 308         if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0)
 309                 fatal("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
 310         for (ai = aitop; ai; ai = ai->ai_next) {
 311                 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 312                 if (s < 0) {
 313                         error("socket: %s", strerror(errno));
 314                         continue;
 315                 }
 316                 if (set_nonblock(s) == -1)
 317                         fatal("%s: set_nonblock(%d)", __func__, s);
 318                 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
 319                     errno != EINPROGRESS)
 320                         error("connect (`%s'): %s", host, strerror(errno));
 321                 else
 322                         break;
 323                 close(s);
 324                 s = -1;
 325         }
 326         freeaddrinfo(aitop);
 327         return s;
 328 }
 329
 330 static int
 331 conalloc(char *iname, char *oname, int keytype)
 332 {
 333         char *namebase, *name, *namelist;
 334         int s;
 335
 336         namebase = namelist = xstrdup(iname);
 337
 338         do {
 339                 name = xstrsep(&namelist, ",");
 340                 if (!name) {
 341                         free(namebase);
 342                         return (-1);
 343                 }
 344         } while ((s = tcpconnect(name)) < 0);
 345
 346         if (s >= maxfd)
 347                 fatal("conalloc: fdno %d too high", s);
 348         if (fdcon[s].c_status)
 349                 fatal("conalloc: attempt to reuse fdno %d", s);
 350
 351         fdcon[s].c_fd = s;
 352         fdcon[s].c_status = CS_CON;
 353         fdcon[s].c_namebase = namebase;
 354         fdcon[s].c_name = name;
 355         fdcon[s].c_namelist = namelist;
 356         fdcon[s].c_output_name = xstrdup(oname);
 357         fdcon[s].c_data = (char *) &fdcon[s].c_plen;
 358         fdcon[s].c_len = 4;
 359         fdcon[s].c_off = 0;
 360         fdcon[s].c_keytype = keytype;
 361         gettimeofday(&fdcon[s].c_tv, NULL);
 362         fdcon[s].c_tv.tv_sec += timeout;
 363         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 364         FD_SET(s, read_wait);
 365         ncon++;
 366         return (s);
 367 }
 368
 369 static void
 370 confree(int s)
 371 {
 372         if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
 373                 fatal("confree: attempt to free bad fdno %d", s);
 374         close(s);
 375         free(fdcon[s].c_namebase);
 376         free(fdcon[s].c_output_name);
 377         if (fdcon[s].c_status == CS_KEYS)
 378                 free(fdcon[s].c_data);
 379         fdcon[s].c_status = CS_UNUSED;
 380         fdcon[s].c_keytype = 0;
 381         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 382         FD_CLR(s, read_wait);
 383         ncon--;
 384 }
 385
 386 static void
 387 contouch(int s)
 388 {
 389         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 390         gettimeofday(&fdcon[s].c_tv, NULL);
 391         fdcon[s].c_tv.tv_sec += timeout;
 392         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 393 }
 394
 395 static int
 396 conrecycle(int s)
 397 {
 398         con *c = &fdcon[s];
 399         int ret;
 400
 401         ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
 402         confree(s);
 403         return (ret);
 404 }
 405
 406 static void
 407 congreet(int s)
 408 {
 409         int n = 0, remote_major = 0, remote_minor = 0;
 410         char buf[256], *cp;
 411         char remote_version[sizeof buf];
 412         size_t bufsiz;
 413         con *c = &fdcon[s];
 414
 415         for (;;) {
 416                 memset(buf, '\0', sizeof(buf));
 417                 bufsiz = sizeof(buf);
 418                 cp = buf;
 419                 while (bufsiz-- &&
 420                     (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
 421                         if (*cp == '\r')
 422                                 *cp = '\n';
 423                         cp++;
 424                 }
 425                 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
 426                         break;
 427         }
 428         if (n == 0) {
 429                 switch (errno) {
 430                 case EPIPE:
 431                         error("%s: Connection closed by remote host", c->c_name);
 432                         break;
 433                 case ECONNREFUSED:
 434                         break;
 435                 default:
 436                         error("read (%s): %s", c->c_name, strerror(errno));
 437                         break;
 438                 }
 439                 conrecycle(s);
 440                 return;
 441         }
 442         if (*cp != '\n' && *cp != '\r') {
 443                 error("%s: bad greeting", c->c_name);
 444                 confree(s);
 445                 return;
 446         }
 447         *cp = '\0';
 448         if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
 449             &remote_major, &remote_minor, remote_version) == 3)
 450                 compat_datafellows(remote_version);
 451         else
 452                 datafellows = 0;
 453         if (c->c_keytype != KT_RSA1) {
 454                 if (!ssh2_capable(remote_major, remote_minor)) {
 455                         debug("%s doesn't support ssh2", c->c_name);
 456                         confree(s);
 457                         return;
 458                 }
 459         } else if (remote_major != 1) {
 460                 debug("%s doesn't support ssh1", c->c_name);
 461                 confree(s);
 462                 return;
 463         }
 464         fprintf(stderr, "# %s %s\n", c->c_name, chop(buf));
 465         n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
 466             c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
 467             c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
 468         if (n < 0 || (size_t)n >= sizeof(buf)) {
 469                 error("snprintf: buffer too small");
 470                 confree(s);
 471                 return;
 472         }
 473         if (atomicio(vwrite, s, buf, n) != (size_t)n) {
 474                 error("write (%s): %s", c->c_name, strerror(errno));
 475                 confree(s);
 476                 return;
 477         }
 478         if (c->c_keytype != KT_RSA1) {
 479                 keyprint(c, keygrab_ssh2(c));
 480                 confree(s);
 481                 return;
 482         }
 483         c->c_status = CS_SIZE;
 484         contouch(s);
 485 }
 486
 487 static void
 488 conread(int s)
 489 {
 490         con *c = &fdcon[s];
 491         size_t n;
 492
 493         if (c->c_status == CS_CON) {
 494                 congreet(s);
 495                 return;
 496         }
 497         n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
 498         if (n == 0) {
 499                 error("read (%s): %s", c->c_name, strerror(errno));
 500                 confree(s);
 501                 return;
 502         }
 503         c->c_off += n;
 504
 505         if (c->c_off == c->c_len)
 506                 switch (c->c_status) {
 507                 case CS_SIZE:
 508                         c->c_plen = htonl(c->c_plen);
 509                         c->c_len = c->c_plen + 8 - (c->c_plen & 7);
 510                         c->c_off = 0;
 511                         c->c_data = xmalloc(c->c_len);
 512                         c->c_status = CS_KEYS;
 513                         break;
 514 #ifdef WITH_SSH1
 515                 case CS_KEYS:
 516                         keyprint(c, keygrab_ssh1(c));
 517                         confree(s);
 518                         return;
 519 #endif
 520                 default:
 521                         fatal("conread: invalid status %d", c->c_status);
 522                         break;
 523                 }
 524
 525         contouch(s);
 526 }
 527
 528 static void
 529 conloop(void)
 530 {
 531         struct timeval seltime, now;
 532         fd_set *r, *e;
 533         con *c;
 534         int i;
 535
 536         gettimeofday(&now, NULL);
 537         c = TAILQ_FIRST(&tq);
 538
 539         if (c && (c->c_tv.tv_sec > now.tv_sec ||
 540             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
 541                 seltime = c->c_tv;
 542                 seltime.tv_sec -= now.tv_sec;
 543                 seltime.tv_usec -= now.tv_usec;
 544                 if (seltime.tv_usec < 0) {
 545                         seltime.tv_usec += 1000000;
 546                         seltime.tv_sec--;
 547                 }
 548         } else
 549                 timerclear(&seltime);
 550
 551         r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 552         e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 553         memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
 554         memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
 555
 556         while (select(maxfd, r, NULL, e, &seltime) == -1 &&
 557             (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
 558                 ;
 559
 560         for (i = 0; i < maxfd; i++) {
 561                 if (FD_ISSET(i, e)) {
 562                         error("%s: exception!", fdcon[i].c_name);
 563                         confree(i);
 564                 } else if (FD_ISSET(i, r))
 565                         conread(i);
 566         }
 567         free(r);
 568         free(e);
 569
 570         c = TAILQ_FIRST(&tq);
 571         while (c && (c->c_tv.tv_sec < now.tv_sec ||
 572             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
 573                 int s = c->c_fd;
 574
 575                 c = TAILQ_NEXT(c, c_link);
 576                 conrecycle(s);
 577         }
 578 }
 579
 580 static void
 581 do_host(char *host)
 582 {
 583         char *name = strnnsep(&host, " \t\n");
 584         int j;
 585
 586         if (name == NULL)
 587                 return;
 588         for (j = KT_RSA1; j <= KT_ED25519; j *= 2) {
 589                 if (get_keytypes & j) {
 590                         while (ncon >= MAXCON)
 591                                 conloop();
 592                         conalloc(name, *host ? host : name, j);
 593                 }
 594         }
 595 }
 596
 597 void
 598 fatal(const char *fmt,...)
 599 {
 600         va_list args;
 601
 602         va_start(args, fmt);
 603         do_log(SYSLOG_LEVEL_FATAL, fmt, args);
 604         va_end(args);
 605         if (nonfatal_fatal)
 606                 longjmp(kexjmp, -1);
 607         else
 608                 exit(255);
 609 }
 610
 611 static void
 612 usage(void)
 613 {
 614         fprintf(stderr,
 615             "usage: %s [-46Hv] [-f file] [-p port] [-T timeout] [-t type]\n"
 616             "\t\t   [host | addrlist namelist] ...\n",
 617             __progname);
 618         exit(1);
 619 }
 620
 621 int
 622 main(int argc, char **argv)
 623 {
 624         int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
 625         int opt, fopt_count = 0, j;
 626         char *tname, *cp, line[NI_MAXHOST];
 627         FILE *fp;
 628         u_long linenum;
 629
 630         extern int optind;
 631         extern char *optarg;
 632
 633         __progname = ssh_get_progname(argv[0]);
 634         seed_rng();
 635         TAILQ_INIT(&tq);
 636
 637         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 638         sanitise_stdfd();
 639
 640         if (argc <= 1)
 641                 usage();
 642
 643         while ((opt = getopt(argc, argv, "Hv46p:T:t:f:")) != -1) {
 644                 switch (opt) {
 645                 case 'H':
 646                         hash_hosts = 1;
 647                         break;
 648                 case 'p':
 649                         ssh_port = a2port(optarg);
 650                         if (ssh_port <= 0) {
 651                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 652                                 exit(1);
 653                         }
 654                         break;
 655                 case 'T':
 656                         timeout = convtime(optarg);
 657                         if (timeout == -1 || timeout == 0) {
 658                                 fprintf(stderr, "Bad timeout '%s'\n", optarg);
 659                                 usage();
 660                         }
 661                         break;
 662                 case 'v':
 663                         if (!debug_flag) {
 664                                 debug_flag = 1;
 665                                 log_level = SYSLOG_LEVEL_DEBUG1;
 666                         }
 667                         else if (log_level < SYSLOG_LEVEL_DEBUG3)
 668                                 log_level++;
 669                         else
 670                                 fatal("Too high debugging level.");
 671                         break;
 672                 case 'f':
 673                         if (strcmp(optarg, "-") == 0)
 674                                 optarg = NULL;
 675                         argv[fopt_count++] = optarg;
 676                         break;
 677                 case 't':
 678                         get_keytypes = 0;
 679                         tname = strtok(optarg, ",");
 680                         while (tname) {
 681                                 int type = key_type_from_name(tname);
 682                                 switch (type) {
 683                                 case KEY_RSA1:
 684                                         get_keytypes |= KT_RSA1;
 685                                         break;
 686                                 case KEY_DSA:
 687                                         get_keytypes |= KT_DSA;
 688                                         break;
 689                                 case KEY_ECDSA:
 690                                         get_keytypes |= KT_ECDSA;
 691                                         break;
 692                                 case KEY_RSA:
 693                                         get_keytypes |= KT_RSA;
 694                                         break;
 695                                 case KEY_ED25519:
 696                                         get_keytypes |= KT_ED25519;
 697                                         break;
 698                                 case KEY_UNSPEC:
 699                                         fatal("unknown key type %s", tname);
 700                                 }
 701                                 tname = strtok(NULL, ",");
 702                         }
 703                         break;
 704                 case '4':
 705                         IPv4or6 = AF_INET;
 706                         break;
 707                 case '6':
 708                         IPv4or6 = AF_INET6;
 709                         break;
 710                 case '?':
 711                 default:
 712                         usage();
 713                 }
 714         }
 715         if (optind == argc && !fopt_count)
 716                 usage();
 717
 718         log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
 719
 720         maxfd = fdlim_get(1);
 721         if (maxfd < 0)
 722                 fatal("%s: fdlim_get: bad value", __progname);
 723         if (maxfd > MAXMAXFD)
 724                 maxfd = MAXMAXFD;
 725         if (MAXCON <= 0)
 726                 fatal("%s: not enough file descriptors", __progname);
 727         if (maxfd > fdlim_get(0))
 728                 fdlim_set(maxfd);
 729         fdcon = xcalloc(maxfd, sizeof(con));
 730
 731         read_wait_nfdset = howmany(maxfd, NFDBITS);
 732         read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 733
 734         for (j = 0; j < fopt_count; j++) {
 735                 if (argv[j] == NULL)
 736                         fp = stdin;
 737                 else if ((fp = fopen(argv[j], "r")) == NULL)
 738                         fatal("%s: %s: %s", __progname, argv[j],
 739                             strerror(errno));
 740                 linenum = 0;
 741
 742                 while (read_keyfile_line(fp,
 743                     argv[j] == NULL ? "(stdin)" : argv[j], line, sizeof(line),
 744                     &linenum) != -1) {
 745                         /* Chomp off trailing whitespace and comments */
 746                         if ((cp = strchr(line, '#')) == NULL)
 747                                 cp = line + strlen(line) - 1;
 748                         while (cp >= line) {
 749                                 if (*cp == ' ' || *cp == '\t' ||
 750                                     *cp == '\n' || *cp == '#')
 751                                         *cp-- = '\0';
 752                                 else
 753                                         break;
 754                         }
 755
 756                         /* Skip empty lines */
 757                         if (*line == '\0')
 758                                 continue;
 759
 760                         do_host(line);
 761                 }
 762
 763                 if (ferror(fp))
 764                         fatal("%s: %s: %s", __progname, argv[j],
 765                             strerror(errno));
 766
 767                 fclose(fp);
 768         }
 769
 770         while (optind < argc)
 771                 do_host(argv[optind++]);
 772
 773         while (ncon > 0)
 774                 conloop();
 775
 776         return (0);
 777 }