crypto/openssh/ssh-keyscan.c

   1 /* $OpenBSD: ssh-keyscan.c,v 1.106 2016/05/02 10:26:04 djm 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 <sys/types.h>
  13 #include "openbsd-compat/sys-queue.h"
  14 #include <sys/resource.h>
  15 #ifdef HAVE_SYS_TIME_H
  16 # include <sys/time.h>
  17 #endif
  18
  19 #include <netinet/in.h>
  20 #include <arpa/inet.h>
  21
  22 #include <openssl/bn.h>
  23
  24 #include <netdb.h>
  25 #include <errno.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 "sshbuf.h"
  37 #include "sshkey.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 #include "ssherr.h"
  49 #include "ssh_api.h"
  50
  51 /* Flag indicating whether IPv4 or IPv6.  This can be set on the command line.
  52    Default value is AF_UNSPEC means both IPv4 and IPv6. */
  53 int IPv4or6 = AF_UNSPEC;
  54
  55 int ssh_port = SSH_DEFAULT_PORT;
  56
  57 #define KT_RSA1         1
  58 #define KT_DSA          2
  59 #define KT_RSA          4
  60 #define KT_ECDSA        8
  61 #define KT_ED25519      16
  62
  63 int get_cert = 0;
  64 int get_keytypes = KT_RSA|KT_ECDSA|KT_ED25519;
  65
  66 int hash_hosts = 0;             /* Hash hostname on output */
  67
  68 #define MAXMAXFD 256
  69
  70 /* The number of seconds after which to give up on a TCP connection */
  71 int timeout = 5;
  72
  73 int maxfd;
  74 #define MAXCON (maxfd - 10)
  75
  76 extern char *__progname;
  77 fd_set *read_wait;
  78 size_t read_wait_nfdset;
  79 int ncon;
  80
  81 struct ssh *active_state = NULL; /* XXX needed for linking */
  82
  83 /*
  84  * Keep a connection structure for each file descriptor.  The state
  85  * associated with file descriptor n is held in fdcon[n].
  86  */
  87 typedef struct Connection {
  88         u_char c_status;        /* State of connection on this file desc. */
  89 #define CS_UNUSED 0             /* File descriptor unused */
  90 #define CS_CON 1                /* Waiting to connect/read greeting */
  91 #define CS_SIZE 2               /* Waiting to read initial packet size */
  92 #define CS_KEYS 3               /* Waiting to read public key packet */
  93         int c_fd;               /* Quick lookup: c->c_fd == c - fdcon */
  94         int c_plen;             /* Packet length field for ssh packet */
  95         int c_len;              /* Total bytes which must be read. */
  96         int c_off;              /* Length of data read so far. */
  97         int c_keytype;          /* Only one of KT_RSA1, KT_DSA, or KT_RSA */
  98         sig_atomic_t c_done;    /* SSH2 done */
  99         char *c_namebase;       /* Address to free for c_name and c_namelist */
 100         char *c_name;           /* Hostname of connection for errors */
 101         char *c_namelist;       /* Pointer to other possible addresses */
 102         char *c_output_name;    /* Hostname of connection for output */
 103         char *c_data;           /* Data read from this fd */
 104         struct ssh *c_ssh;      /* SSH-connection */
 105         struct timeval c_tv;    /* Time at which connection gets aborted */
 106         TAILQ_ENTRY(Connection) c_link; /* List of connections in timeout order. */
 107 } con;
 108
 109 TAILQ_HEAD(conlist, Connection) tq;     /* Timeout Queue */
 110 con *fdcon;
 111
 112 static void keyprint(con *c, struct sshkey *key);
 113
 114 static int
 115 fdlim_get(int hard)
 116 {
 117 #if defined(HAVE_GETRLIMIT) && defined(RLIMIT_NOFILE)
 118         struct rlimit rlfd;
 119
 120         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 121                 return (-1);
 122         if ((hard ? rlfd.rlim_max : rlfd.rlim_cur) == RLIM_INFINITY)
 123                 return SSH_SYSFDMAX;
 124         else
 125                 return hard ? rlfd.rlim_max : rlfd.rlim_cur;
 126 #else
 127         return SSH_SYSFDMAX;
 128 #endif
 129 }
 130
 131 static int
 132 fdlim_set(int lim)
 133 {
 134 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 135         struct rlimit rlfd;
 136 #endif
 137
 138         if (lim <= 0)
 139                 return (-1);
 140 #if defined(HAVE_SETRLIMIT) && defined(RLIMIT_NOFILE)
 141         if (getrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 142                 return (-1);
 143         rlfd.rlim_cur = lim;
 144         if (setrlimit(RLIMIT_NOFILE, &rlfd) < 0)
 145                 return (-1);
 146 #elif defined (HAVE_SETDTABLESIZE)
 147         setdtablesize(lim);
 148 #endif
 149         return (0);
 150 }
 151
 152 /*
 153  * This is an strsep function that returns a null field for adjacent
 154  * separators.  This is the same as the 4.4BSD strsep, but different from the
 155  * one in the GNU libc.
 156  */
 157 static char *
 158 xstrsep(char **str, const char *delim)
 159 {
 160         char *s, *e;
 161
 162         if (!**str)
 163                 return (NULL);
 164
 165         s = *str;
 166         e = s + strcspn(s, delim);
 167
 168         if (*e != '\0')
 169                 *e++ = '\0';
 170         *str = e;
 171
 172         return (s);
 173 }
 174
 175 /*
 176  * Get the next non-null token (like GNU strsep).  Strsep() will return a
 177  * null token for two adjacent separators, so we may have to loop.
 178  */
 179 static char *
 180 strnnsep(char **stringp, char *delim)
 181 {
 182         char *tok;
 183
 184         do {
 185                 tok = xstrsep(stringp, delim);
 186         } while (tok && *tok == '\0');
 187         return (tok);
 188 }
 189
 190 #ifdef WITH_SSH1
 191 static struct sshkey *
 192 keygrab_ssh1(con *c)
 193 {
 194         static struct sshkey *rsa;
 195         static struct sshbuf *msg;
 196         int r;
 197         u_char type;
 198
 199         if (rsa == NULL) {
 200                 if ((rsa = sshkey_new(KEY_RSA1)) == NULL) {
 201                         error("%s: sshkey_new failed", __func__);
 202                         return NULL;
 203                 }
 204                 if ((msg = sshbuf_new()) == NULL)
 205                         fatal("%s: sshbuf_new failed", __func__);
 206         }
 207         if ((r = sshbuf_put(msg, c->c_data, c->c_plen)) != 0 ||
 208             (r = sshbuf_consume(msg, 8 - (c->c_plen & 7))) != 0 || /* padding */
 209             (r = sshbuf_get_u8(msg, &type)) != 0)
 210                 goto buf_err;
 211         if (type != (int) SSH_SMSG_PUBLIC_KEY) {
 212                 error("%s: invalid packet type", c->c_name);
 213                 sshbuf_reset(msg);
 214                 return NULL;
 215         }
 216         if ((r = sshbuf_consume(msg, 8)) != 0 || /* cookie */
 217             /* server key */
 218             (r = sshbuf_get_u32(msg, NULL)) != 0 ||
 219             (r = sshbuf_get_bignum1(msg, NULL)) != 0 ||
 220             (r = sshbuf_get_bignum1(msg, NULL)) != 0 ||
 221             /* host key */
 222             (r = sshbuf_get_u32(msg, NULL)) != 0 ||
 223             (r = sshbuf_get_bignum1(msg, rsa->rsa->e)) != 0 ||
 224             (r = sshbuf_get_bignum1(msg, rsa->rsa->n)) != 0) {
 225  buf_err:
 226                 error("%s: buffer error: %s", __func__, ssh_err(r));
 227                 sshbuf_reset(msg);
 228                 return NULL;
 229         }
 230
 231         sshbuf_reset(msg);
 232
 233         return (rsa);
 234 }
 235 #endif
 236
 237 static int
 238 key_print_wrapper(struct sshkey *hostkey, struct ssh *ssh)
 239 {
 240         con *c;
 241
 242         if ((c = ssh_get_app_data(ssh)) != NULL)
 243                 keyprint(c, hostkey);
 244         /* always abort key exchange */
 245         return -1;
 246 }
 247
 248 static int
 249 ssh2_capable(int remote_major, int remote_minor)
 250 {
 251         switch (remote_major) {
 252         case 1:
 253                 if (remote_minor == 99)
 254                         return 1;
 255                 break;
 256         case 2:
 257                 return 1;
 258         default:
 259                 break;
 260         }
 261         return 0;
 262 }
 263
 264 static void
 265 keygrab_ssh2(con *c)
 266 {
 267         char *myproposal[PROPOSAL_MAX] = { KEX_CLIENT };
 268         int r;
 269
 270         enable_compat20();
 271         switch (c->c_keytype) {
 272         case KT_DSA:
 273                 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
 274                     "ssh-dss-cert-v01@openssh.com" : "ssh-dss";
 275                 break;
 276         case KT_RSA:
 277                 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
 278                     "ssh-rsa-cert-v01@openssh.com" : "ssh-rsa";
 279                 break;
 280         case KT_ED25519:
 281                 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
 282                     "ssh-ed25519-cert-v01@openssh.com" : "ssh-ed25519";
 283                 break;
 284         case KT_ECDSA:
 285                 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = get_cert ?
 286                     "ecdsa-sha2-nistp256-cert-v01@openssh.com,"
 287                     "ecdsa-sha2-nistp384-cert-v01@openssh.com,"
 288                     "ecdsa-sha2-nistp521-cert-v01@openssh.com" :
 289                     "ecdsa-sha2-nistp256,"
 290                     "ecdsa-sha2-nistp384,"
 291                     "ecdsa-sha2-nistp521";
 292                 break;
 293         default:
 294                 fatal("unknown key type %d", c->c_keytype);
 295                 break;
 296         }
 297         if ((r = kex_setup(c->c_ssh, myproposal)) != 0) {
 298                 free(c->c_ssh);
 299                 fprintf(stderr, "kex_setup: %s\n", ssh_err(r));
 300                 exit(1);
 301         }
 302 #ifdef WITH_OPENSSL
 303         c->c_ssh->kex->kex[KEX_DH_GRP1_SHA1] = kexdh_client;
 304         c->c_ssh->kex->kex[KEX_DH_GRP14_SHA1] = kexdh_client;
 305         c->c_ssh->kex->kex[KEX_DH_GRP14_SHA256] = kexdh_client;
 306         c->c_ssh->kex->kex[KEX_DH_GRP16_SHA512] = kexdh_client;
 307         c->c_ssh->kex->kex[KEX_DH_GRP18_SHA512] = kexdh_client;
 308         c->c_ssh->kex->kex[KEX_DH_GEX_SHA1] = kexgex_client;
 309         c->c_ssh->kex->kex[KEX_DH_GEX_SHA256] = kexgex_client;
 310 # ifdef OPENSSL_HAS_ECC
 311         c->c_ssh->kex->kex[KEX_ECDH_SHA2] = kexecdh_client;
 312 # endif
 313 #endif
 314         c->c_ssh->kex->kex[KEX_C25519_SHA256] = kexc25519_client;
 315         ssh_set_verify_host_key_callback(c->c_ssh, key_print_wrapper);
 316         /*
 317          * do the key-exchange until an error occurs or until
 318          * the key_print_wrapper() callback sets c_done.
 319          */
 320         ssh_dispatch_run(c->c_ssh, DISPATCH_BLOCK, &c->c_done, c->c_ssh);
 321 }
 322
 323 static void
 324 keyprint_one(char *host, struct sshkey *key)
 325 {
 326         char *hostport;
 327
 328         if (hash_hosts && (host = host_hash(host, NULL, 0)) == NULL)
 329                 fatal("host_hash failed");
 330
 331         hostport = put_host_port(host, ssh_port);
 332         if (!get_cert)
 333                 fprintf(stdout, "%s ", hostport);
 334         sshkey_write(key, stdout);
 335         fputs("\n", stdout);
 336         free(hostport);
 337 }
 338
 339 static void
 340 keyprint(con *c, struct sshkey *key)
 341 {
 342         char *hosts = c->c_output_name ? c->c_output_name : c->c_name;
 343         char *host, *ohosts;
 344
 345         if (key == NULL)
 346                 return;
 347         if (get_cert || (!hash_hosts && ssh_port == SSH_DEFAULT_PORT)) {
 348                 keyprint_one(hosts, key);
 349                 return;
 350         }
 351         ohosts = hosts = xstrdup(hosts);
 352         while ((host = strsep(&hosts, ",")) != NULL)
 353                 keyprint_one(host, key);
 354         free(ohosts);
 355 }
 356
 357 static int
 358 tcpconnect(char *host)
 359 {
 360         struct addrinfo hints, *ai, *aitop;
 361         char strport[NI_MAXSERV];
 362         int gaierr, s = -1;
 363
 364         snprintf(strport, sizeof strport, "%d", ssh_port);
 365         memset(&hints, 0, sizeof(hints));
 366         hints.ai_family = IPv4or6;
 367         hints.ai_socktype = SOCK_STREAM;
 368         if ((gaierr = getaddrinfo(host, strport, &hints, &aitop)) != 0) {
 369                 error("getaddrinfo %s: %s", host, ssh_gai_strerror(gaierr));
 370                 return -1;
 371         }
 372         for (ai = aitop; ai; ai = ai->ai_next) {
 373                 s = socket(ai->ai_family, ai->ai_socktype, ai->ai_protocol);
 374                 if (s < 0) {
 375                         error("socket: %s", strerror(errno));
 376                         continue;
 377                 }
 378                 if (set_nonblock(s) == -1)
 379                         fatal("%s: set_nonblock(%d)", __func__, s);
 380                 if (connect(s, ai->ai_addr, ai->ai_addrlen) < 0 &&
 381                     errno != EINPROGRESS)
 382                         error("connect (`%s'): %s", host, strerror(errno));
 383                 else
 384                         break;
 385                 close(s);
 386                 s = -1;
 387         }
 388         freeaddrinfo(aitop);
 389         return s;
 390 }
 391
 392 static int
 393 conalloc(char *iname, char *oname, int keytype)
 394 {
 395         char *namebase, *name, *namelist;
 396         int s;
 397
 398         namebase = namelist = xstrdup(iname);
 399
 400         do {
 401                 name = xstrsep(&namelist, ",");
 402                 if (!name) {
 403                         free(namebase);
 404                         return (-1);
 405                 }
 406         } while ((s = tcpconnect(name)) < 0);
 407
 408         if (s >= maxfd)
 409                 fatal("conalloc: fdno %d too high", s);
 410         if (fdcon[s].c_status)
 411                 fatal("conalloc: attempt to reuse fdno %d", s);
 412
 413         debug3("%s: oname %s kt %d", __func__, oname, keytype);
 414         fdcon[s].c_fd = s;
 415         fdcon[s].c_status = CS_CON;
 416         fdcon[s].c_namebase = namebase;
 417         fdcon[s].c_name = name;
 418         fdcon[s].c_namelist = namelist;
 419         fdcon[s].c_output_name = xstrdup(oname);
 420         fdcon[s].c_data = (char *) &fdcon[s].c_plen;
 421         fdcon[s].c_len = 4;
 422         fdcon[s].c_off = 0;
 423         fdcon[s].c_keytype = keytype;
 424         gettimeofday(&fdcon[s].c_tv, NULL);
 425         fdcon[s].c_tv.tv_sec += timeout;
 426         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 427         FD_SET(s, read_wait);
 428         ncon++;
 429         return (s);
 430 }
 431
 432 static void
 433 confree(int s)
 434 {
 435         if (s >= maxfd || fdcon[s].c_status == CS_UNUSED)
 436                 fatal("confree: attempt to free bad fdno %d", s);
 437         close(s);
 438         free(fdcon[s].c_namebase);
 439         free(fdcon[s].c_output_name);
 440         if (fdcon[s].c_status == CS_KEYS)
 441                 free(fdcon[s].c_data);
 442         fdcon[s].c_status = CS_UNUSED;
 443         fdcon[s].c_keytype = 0;
 444         if (fdcon[s].c_ssh) {
 445                 ssh_packet_close(fdcon[s].c_ssh);
 446                 free(fdcon[s].c_ssh);
 447                 fdcon[s].c_ssh = NULL;
 448         }
 449         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 450         FD_CLR(s, read_wait);
 451         ncon--;
 452 }
 453
 454 static void
 455 contouch(int s)
 456 {
 457         TAILQ_REMOVE(&tq, &fdcon[s], c_link);
 458         gettimeofday(&fdcon[s].c_tv, NULL);
 459         fdcon[s].c_tv.tv_sec += timeout;
 460         TAILQ_INSERT_TAIL(&tq, &fdcon[s], c_link);
 461 }
 462
 463 static int
 464 conrecycle(int s)
 465 {
 466         con *c = &fdcon[s];
 467         int ret;
 468
 469         ret = conalloc(c->c_namelist, c->c_output_name, c->c_keytype);
 470         confree(s);
 471         return (ret);
 472 }
 473
 474 static void
 475 congreet(int s)
 476 {
 477         int n = 0, remote_major = 0, remote_minor = 0;
 478         char buf[256], *cp;
 479         char remote_version[sizeof buf];
 480         size_t bufsiz;
 481         con *c = &fdcon[s];
 482
 483         for (;;) {
 484                 memset(buf, '\0', sizeof(buf));
 485                 bufsiz = sizeof(buf);
 486                 cp = buf;
 487                 while (bufsiz-- &&
 488                     (n = atomicio(read, s, cp, 1)) == 1 && *cp != '\n') {
 489                         if (*cp == '\r')
 490                                 *cp = '\n';
 491                         cp++;
 492                 }
 493                 if (n != 1 || strncmp(buf, "SSH-", 4) == 0)
 494                         break;
 495         }
 496         if (n == 0) {
 497                 switch (errno) {
 498                 case EPIPE:
 499                         error("%s: Connection closed by remote host", c->c_name);
 500                         break;
 501                 case ECONNREFUSED:
 502                         break;
 503                 default:
 504                         error("read (%s): %s", c->c_name, strerror(errno));
 505                         break;
 506                 }
 507                 conrecycle(s);
 508                 return;
 509         }
 510         if (*cp != '\n' && *cp != '\r') {
 511                 error("%s: bad greeting", c->c_name);
 512                 confree(s);
 513                 return;
 514         }
 515         *cp = '\0';
 516         if ((c->c_ssh = ssh_packet_set_connection(NULL, s, s)) == NULL)
 517                 fatal("ssh_packet_set_connection failed");
 518         ssh_packet_set_timeout(c->c_ssh, timeout, 1);
 519         ssh_set_app_data(c->c_ssh, c);  /* back link */
 520         if (sscanf(buf, "SSH-%d.%d-%[^\n]\n",
 521             &remote_major, &remote_minor, remote_version) == 3)
 522                 c->c_ssh->compat = compat_datafellows(remote_version);
 523         else
 524                 c->c_ssh->compat = 0;
 525         if (c->c_keytype != KT_RSA1) {
 526                 if (!ssh2_capable(remote_major, remote_minor)) {
 527                         debug("%s doesn't support ssh2", c->c_name);
 528                         confree(s);
 529                         return;
 530                 }
 531         } else if (remote_major != 1) {
 532                 debug("%s doesn't support ssh1", c->c_name);
 533                 confree(s);
 534                 return;
 535         }
 536         fprintf(stderr, "# %s:%d %s\n", c->c_name, ssh_port, chop(buf));
 537         n = snprintf(buf, sizeof buf, "SSH-%d.%d-OpenSSH-keyscan\r\n",
 538             c->c_keytype == KT_RSA1? PROTOCOL_MAJOR_1 : PROTOCOL_MAJOR_2,
 539             c->c_keytype == KT_RSA1? PROTOCOL_MINOR_1 : PROTOCOL_MINOR_2);
 540         if (n < 0 || (size_t)n >= sizeof(buf)) {
 541                 error("snprintf: buffer too small");
 542                 confree(s);
 543                 return;
 544         }
 545         if (atomicio(vwrite, s, buf, n) != (size_t)n) {
 546                 error("write (%s): %s", c->c_name, strerror(errno));
 547                 confree(s);
 548                 return;
 549         }
 550         if (c->c_keytype != KT_RSA1) {
 551                 keygrab_ssh2(c);
 552                 confree(s);
 553                 return;
 554         }
 555         c->c_status = CS_SIZE;
 556         contouch(s);
 557 }
 558
 559 static void
 560 conread(int s)
 561 {
 562         con *c = &fdcon[s];
 563         size_t n;
 564
 565         if (c->c_status == CS_CON) {
 566                 congreet(s);
 567                 return;
 568         }
 569         n = atomicio(read, s, c->c_data + c->c_off, c->c_len - c->c_off);
 570         if (n == 0) {
 571                 error("read (%s): %s", c->c_name, strerror(errno));
 572                 confree(s);
 573                 return;
 574         }
 575         c->c_off += n;
 576
 577         if (c->c_off == c->c_len)
 578                 switch (c->c_status) {
 579                 case CS_SIZE:
 580                         c->c_plen = htonl(c->c_plen);
 581                         c->c_len = c->c_plen + 8 - (c->c_plen & 7);
 582                         c->c_off = 0;
 583                         c->c_data = xmalloc(c->c_len);
 584                         c->c_status = CS_KEYS;
 585                         break;
 586 #ifdef WITH_SSH1
 587                 case CS_KEYS:
 588                         keyprint(c, keygrab_ssh1(c));
 589                         confree(s);
 590                         return;
 591 #endif
 592                 default:
 593                         fatal("conread: invalid status %d", c->c_status);
 594                         break;
 595                 }
 596
 597         contouch(s);
 598 }
 599
 600 static void
 601 conloop(void)
 602 {
 603         struct timeval seltime, now;
 604         fd_set *r, *e;
 605         con *c;
 606         int i;
 607
 608         gettimeofday(&now, NULL);
 609         c = TAILQ_FIRST(&tq);
 610
 611         if (c && (c->c_tv.tv_sec > now.tv_sec ||
 612             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec > now.tv_usec))) {
 613                 seltime = c->c_tv;
 614                 seltime.tv_sec -= now.tv_sec;
 615                 seltime.tv_usec -= now.tv_usec;
 616                 if (seltime.tv_usec < 0) {
 617                         seltime.tv_usec += 1000000;
 618                         seltime.tv_sec--;
 619                 }
 620         } else
 621                 timerclear(&seltime);
 622
 623         r = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 624         e = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 625         memcpy(r, read_wait, read_wait_nfdset * sizeof(fd_mask));
 626         memcpy(e, read_wait, read_wait_nfdset * sizeof(fd_mask));
 627
 628         while (select(maxfd, r, NULL, e, &seltime) == -1 &&
 629             (errno == EAGAIN || errno == EINTR || errno == EWOULDBLOCK))
 630                 ;
 631
 632         for (i = 0; i < maxfd; i++) {
 633                 if (FD_ISSET(i, e)) {
 634                         error("%s: exception!", fdcon[i].c_name);
 635                         confree(i);
 636                 } else if (FD_ISSET(i, r))
 637                         conread(i);
 638         }
 639         free(r);
 640         free(e);
 641
 642         c = TAILQ_FIRST(&tq);
 643         while (c && (c->c_tv.tv_sec < now.tv_sec ||
 644             (c->c_tv.tv_sec == now.tv_sec && c->c_tv.tv_usec < now.tv_usec))) {
 645                 int s = c->c_fd;
 646
 647                 c = TAILQ_NEXT(c, c_link);
 648                 conrecycle(s);
 649         }
 650 }
 651
 652 static void
 653 do_host(char *host)
 654 {
 655         char *name = strnnsep(&host, " \t\n");
 656         int j;
 657
 658         if (name == NULL)
 659                 return;
 660         for (j = KT_RSA1; j <= KT_ED25519; j *= 2) {
 661                 if (get_keytypes & j) {
 662                         while (ncon >= MAXCON)
 663                                 conloop();
 664                         conalloc(name, *host ? host : name, j);
 665                 }
 666         }
 667 }
 668
 669 void
 670 fatal(const char *fmt,...)
 671 {
 672         va_list args;
 673
 674         va_start(args, fmt);
 675         do_log(SYSLOG_LEVEL_FATAL, fmt, args);
 676         va_end(args);
 677         exit(255);
 678 }
 679
 680 static void
 681 usage(void)
 682 {
 683         fprintf(stderr,
 684             "usage: %s [-46cHv] [-f file] [-p port] [-T timeout] [-t type]\n"
 685             "\t\t   [host | addrlist namelist] ...\n",
 686             __progname);
 687         exit(1);
 688 }
 689
 690 int
 691 main(int argc, char **argv)
 692 {
 693         int debug_flag = 0, log_level = SYSLOG_LEVEL_INFO;
 694         int opt, fopt_count = 0, j;
 695         char *tname, *cp, line[NI_MAXHOST];
 696         FILE *fp;
 697         u_long linenum;
 698
 699         extern int optind;
 700         extern char *optarg;
 701
 702         ssh_malloc_init();      /* must be called before any mallocs */
 703         __progname = ssh_get_progname(argv[0]);
 704         seed_rng();
 705         TAILQ_INIT(&tq);
 706
 707         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 708         sanitise_stdfd();
 709
 710         if (argc <= 1)
 711                 usage();
 712
 713         while ((opt = getopt(argc, argv, "cHv46p:T:t:f:")) != -1) {
 714                 switch (opt) {
 715                 case 'H':
 716                         hash_hosts = 1;
 717                         break;
 718                 case 'c':
 719                         get_cert = 1;
 720                         break;
 721                 case 'p':
 722                         ssh_port = a2port(optarg);
 723                         if (ssh_port <= 0) {
 724                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 725                                 exit(1);
 726                         }
 727                         break;
 728                 case 'T':
 729                         timeout = convtime(optarg);
 730                         if (timeout == -1 || timeout == 0) {
 731                                 fprintf(stderr, "Bad timeout '%s'\n", optarg);
 732                                 usage();
 733                         }
 734                         break;
 735                 case 'v':
 736                         if (!debug_flag) {
 737                                 debug_flag = 1;
 738                                 log_level = SYSLOG_LEVEL_DEBUG1;
 739                         }
 740                         else if (log_level < SYSLOG_LEVEL_DEBUG3)
 741                                 log_level++;
 742                         else
 743                                 fatal("Too high debugging level.");
 744                         break;
 745                 case 'f':
 746                         if (strcmp(optarg, "-") == 0)
 747                                 optarg = NULL;
 748                         argv[fopt_count++] = optarg;
 749                         break;
 750                 case 't':
 751                         get_keytypes = 0;
 752                         tname = strtok(optarg, ",");
 753                         while (tname) {
 754                                 int type = sshkey_type_from_name(tname);
 755                                 switch (type) {
 756                                 case KEY_RSA1:
 757                                         get_keytypes |= KT_RSA1;
 758                                         break;
 759                                 case KEY_DSA:
 760                                         get_keytypes |= KT_DSA;
 761                                         break;
 762                                 case KEY_ECDSA:
 763                                         get_keytypes |= KT_ECDSA;
 764                                         break;
 765                                 case KEY_RSA:
 766                                         get_keytypes |= KT_RSA;
 767                                         break;
 768                                 case KEY_ED25519:
 769                                         get_keytypes |= KT_ED25519;
 770                                         break;
 771                                 case KEY_UNSPEC:
 772                                         fatal("unknown key type %s", tname);
 773                                 }
 774                                 tname = strtok(NULL, ",");
 775                         }
 776                         break;
 777                 case '4':
 778                         IPv4or6 = AF_INET;
 779                         break;
 780                 case '6':
 781                         IPv4or6 = AF_INET6;
 782                         break;
 783                 case '?':
 784                 default:
 785                         usage();
 786                 }
 787         }
 788         if (optind == argc && !fopt_count)
 789                 usage();
 790
 791         log_init("ssh-keyscan", log_level, SYSLOG_FACILITY_USER, 1);
 792
 793         maxfd = fdlim_get(1);
 794         if (maxfd < 0)
 795                 fatal("%s: fdlim_get: bad value", __progname);
 796         if (maxfd > MAXMAXFD)
 797                 maxfd = MAXMAXFD;
 798         if (MAXCON <= 0)
 799                 fatal("%s: not enough file descriptors", __progname);
 800         if (maxfd > fdlim_get(0))
 801                 fdlim_set(maxfd);
 802         fdcon = xcalloc(maxfd, sizeof(con));
 803
 804         read_wait_nfdset = howmany(maxfd, NFDBITS);
 805         read_wait = xcalloc(read_wait_nfdset, sizeof(fd_mask));
 806
 807         for (j = 0; j < fopt_count; j++) {
 808                 if (argv[j] == NULL)
 809                         fp = stdin;
 810                 else if ((fp = fopen(argv[j], "r")) == NULL)
 811                         fatal("%s: %s: %s", __progname, argv[j],
 812                             strerror(errno));
 813                 linenum = 0;
 814
 815                 while (read_keyfile_line(fp,
 816                     argv[j] == NULL ? "(stdin)" : argv[j], line, sizeof(line),
 817                     &linenum) != -1) {
 818                         /* Chomp off trailing whitespace and comments */
 819                         if ((cp = strchr(line, '#')) == NULL)
 820                                 cp = line + strlen(line) - 1;
 821                         while (cp >= line) {
 822                                 if (*cp == ' ' || *cp == '\t' ||
 823                                     *cp == '\n' || *cp == '#')
 824                                         *cp-- = '\0';
 825                                 else
 826                                         break;
 827                         }
 828
 829                         /* Skip empty lines */
 830                         if (*line == '\0')
 831                                 continue;
 832
 833                         do_host(line);
 834                 }
 835
 836                 if (ferror(fp))
 837                         fatal("%s: %s: %s", __progname, argv[j],
 838                             strerror(errno));
 839
 840                 fclose(fp);
 841         }
 842
 843         while (optind < argc)
 844                 do_host(argv[optind++]);
 845
 846         while (ncon > 0)
 847                 conloop();
 848
 849         return (0);
 850 }