1 /* $OpenBSD: ssh.c,v 1.500 2019/01/19 21:43:56 djm Exp $ */
2 /*
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
6 * Ssh client program. This program can be used to log into a remote machine.
7 * The software supports strong authentication, encryption, and forwarding
8 * of X11, TCP/IP, and authentication connections.
9 *
10 * As far as I am concerned, the code I have written for this software
11 * can be used freely for any purpose. Any derived versions of this
12 * software must be clearly marked as such, and if the derived work is
13 * incompatible with the protocol description in the RFC file, it must be
14 * called by a name other than "ssh" or "Secure Shell".
15 *
16 * Copyright (c) 1999 Niels Provos. All rights reserved.
17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved.
18 *
19 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
20 * in Canada (German citizen).
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the above copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 *
31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
41 */
42
43 #include "includes.h"
44
45 #include <sys/types.h>
46 #ifdef HAVE_SYS_STAT_H
47 # include <sys/stat.h>
48 #endif
49 #include <sys/resource.h>
50 #include <sys/ioctl.h>
51 #include <sys/socket.h>
52 #include <sys/wait.h>
53
54 #include <ctype.h>
55 #include <errno.h>
56 #include <fcntl.h>
57 #include <netdb.h>
58 #ifdef HAVE_PATHS_H
59 #include <paths.h>
60 #endif
61 #include <pwd.h>
62 #include <signal.h>
63 #include <stdarg.h>
64 #include <stddef.h>
65 #include <stdio.h>
66 #include <stdlib.h>
67 #include <string.h>
68 #include <unistd.h>
69 #include <limits.h>
70 #include <locale.h>
71
72 #include <netinet/in.h>
73 #include <arpa/inet.h>
74
75 #ifdef WITH_OPENSSL
76 #include <openssl/evp.h>
77 #include <openssl/err.h>
78 #endif
79 #include "openbsd-compat/openssl-compat.h"
80 #include "openbsd-compat/sys-queue.h"
81
82 #include "xmalloc.h"
83 #include "ssh.h"
84 #include "ssh2.h"
85 #include "canohost.h"
86 #include "compat.h"
87 #include "cipher.h"
88 #include "digest.h"
89 #include "packet.h"
90 #include "sshbuf.h"
91 #include "channels.h"
92 #include "sshkey.h"
93 #include "authfd.h"
94 #include "authfile.h"
95 #include "pathnames.h"
96 #include "dispatch.h"
97 #include "clientloop.h"
98 #include "log.h"
99 #include "misc.h"
100 #include "readconf.h"
101 #include "sshconnect.h"
102 #include "kex.h"
103 #include "mac.h"
104 #include "sshpty.h"
105 #include "match.h"
106 #include "msg.h"
107 #include "version.h"
108 #include "ssherr.h"
109 #include "myproposal.h"
110 #include "utf8.h"
111
112 #ifdef ENABLE_PKCS11
113 #include "ssh-pkcs11.h"
114 #endif
115
116 extern char *__progname;
117
118 /* Saves a copy of argv for setproctitle emulation */
119 #ifndef HAVE_SETPROCTITLE
120 static char **saved_av;
121 #endif
122
123 /* Flag indicating whether debug mode is on. May be set on the command line. */
124 int debug_flag = 0;
125
126 /* Flag indicating whether a tty should be requested */
127 int tty_flag = 0;
128
129 /* don't exec a shell */
130 int no_shell_flag = 0;
131
132 /*
133 * Flag indicating that nothing should be read from stdin. This can be set
134 * on the command line.
135 */
136 int stdin_null_flag = 0;
137
138 /*
139 * Flag indicating that the current process should be backgrounded and
140 * a new slave launched in the foreground for ControlPersist.
141 */
142 int need_controlpersist_detach = 0;
143
144 /* Copies of flags for ControlPersist foreground slave */
145 int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty;
146
147 /*
148 * Flag indicating that ssh should fork after authentication. This is useful
149 * so that the passphrase can be entered manually, and then ssh goes to the
150 * background.
151 */
152 int fork_after_authentication_flag = 0;
153
154 /*
155 * General data structure for command line options and options configurable
156 * in configuration files. See readconf.h.
157 */
158 Options options;
159
160 /* optional user configfile */
161 char *config = NULL;
162
163 /*
164 * Name of the host we are connecting to. This is the name given on the
165 * command line, or the HostName specified for the user-supplied name in a
166 * configuration file.
167 */
168 char *host;
169
170 /* Various strings used to to percent_expand() arguments */
171 static char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
172 static char uidstr[32], *host_arg, *conn_hash_hex;
173
174 /* socket address the host resolves to */
175 struct sockaddr_storage hostaddr;
176
177 /* Private host keys. */
178 Sensitive sensitive_data;
179
180 /* command to be executed */
181 struct sshbuf *command;
182
183 /* Should we execute a command or invoke a subsystem? */
184 int subsystem_flag = 0;
185
186 /* # of replies received for global requests */
187 static int remote_forward_confirms_received = 0;
188
189 /* mux.c */
190 extern int muxserver_sock;
191 extern u_int muxclient_command;
192
193 /* Prints a help message to the user. This function never returns. */
194
195 static void
usage(void)196 usage(void)
197 {
198 fprintf(stderr,
199 "usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]\n"
200 " [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]\n"
201 " [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]\n"
202 " [-i identity_file] [-J [user@]host[:port]] [-L address]\n"
203 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
204 " [-Q query_option] [-R address] [-S ctl_path] [-W host:port]\n"
205 " [-w local_tun[:remote_tun]] destination [command]\n"
206 );
207 exit(255);
208 }
209
210 static int ssh_session2(struct ssh *, struct passwd *);
211 static void load_public_identity_files(struct passwd *);
212 static void main_sigchld_handler(int);
213
214 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */
215 static void
tilde_expand_paths(char ** paths,u_int num_paths)216 tilde_expand_paths(char **paths, u_int num_paths)
217 {
218 u_int i;
219 char *cp;
220
221 for (i = 0; i < num_paths; i++) {
222 cp = tilde_expand_filename(paths[i], getuid());
223 free(paths[i]);
224 paths[i] = cp;
225 }
226 }
227
228 /*
229 * Attempt to resolve a host name / port to a set of addresses and
230 * optionally return any CNAMEs encountered along the way.
231 * Returns NULL on failure.
232 * NB. this function must operate with a options having undefined members.
233 */
234 static struct addrinfo *
resolve_host(const char * name,int port,int logerr,char * cname,size_t clen)235 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen)
236 {
237 char strport[NI_MAXSERV];
238 struct addrinfo hints, *res;
239 int gaierr, loglevel = SYSLOG_LEVEL_DEBUG1;
240
241 if (port <= 0)
242 port = default_ssh_port();
243
244 snprintf(strport, sizeof strport, "%d", port);
245 memset(&hints, 0, sizeof(hints));
246 hints.ai_family = options.address_family == -1 ?
247 AF_UNSPEC : options.address_family;
248 hints.ai_socktype = SOCK_STREAM;
249 if (cname != NULL)
250 hints.ai_flags = AI_CANONNAME;
251 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
252 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA))
253 loglevel = SYSLOG_LEVEL_ERROR;
254 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s",
255 __progname, name, ssh_gai_strerror(gaierr));
256 return NULL;
257 }
258 if (cname != NULL && res->ai_canonname != NULL) {
259 if (strlcpy(cname, res->ai_canonname, clen) >= clen) {
260 error("%s: host \"%s\" cname \"%s\" too long (max %lu)",
261 __func__, name, res->ai_canonname, (u_long)clen);
262 if (clen > 0)
263 *cname = '\0';
264 }
265 }
266 return res;
267 }
268
269 /* Returns non-zero if name can only be an address and not a hostname */
270 static int
is_addr_fast(const char * name)271 is_addr_fast(const char *name)
272 {
273 return (strchr(name, '%') != NULL || strchr(name, ':') != NULL ||
274 strspn(name, "0123456789.") == strlen(name));
275 }
276
277 /* Returns non-zero if name represents a valid, single address */
278 static int
is_addr(const char * name)279 is_addr(const char *name)
280 {
281 char strport[NI_MAXSERV];
282 struct addrinfo hints, *res;
283
284 if (is_addr_fast(name))
285 return 1;
286
287 snprintf(strport, sizeof strport, "%u", default_ssh_port());
288 memset(&hints, 0, sizeof(hints));
289 hints.ai_family = options.address_family == -1 ?
290 AF_UNSPEC : options.address_family;
291 hints.ai_socktype = SOCK_STREAM;
292 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV;
293 if (getaddrinfo(name, strport, &hints, &res) != 0)
294 return 0;
295 if (res == NULL || res->ai_next != NULL) {
296 freeaddrinfo(res);
297 return 0;
298 }
299 freeaddrinfo(res);
300 return 1;
301 }
302
303 /*
304 * Attempt to resolve a numeric host address / port to a single address.
305 * Returns a canonical address string.
306 * Returns NULL on failure.
307 * NB. this function must operate with a options having undefined members.
308 */
309 static struct addrinfo *
resolve_addr(const char * name,int port,char * caddr,size_t clen)310 resolve_addr(const char *name, int port, char *caddr, size_t clen)
311 {
312 char addr[NI_MAXHOST], strport[NI_MAXSERV];
313 struct addrinfo hints, *res;
314 int gaierr;
315
316 if (port <= 0)
317 port = default_ssh_port();
318 snprintf(strport, sizeof strport, "%u", port);
319 memset(&hints, 0, sizeof(hints));
320 hints.ai_family = options.address_family == -1 ?
321 AF_UNSPEC : options.address_family;
322 hints.ai_socktype = SOCK_STREAM;
323 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV;
324 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
325 debug2("%s: could not resolve name %.100s as address: %s",
326 __func__, name, ssh_gai_strerror(gaierr));
327 return NULL;
328 }
329 if (res == NULL) {
330 debug("%s: getaddrinfo %.100s returned no addresses",
331 __func__, name);
332 return NULL;
333 }
334 if (res->ai_next != NULL) {
335 debug("%s: getaddrinfo %.100s returned multiple addresses",
336 __func__, name);
337 goto fail;
338 }
339 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen,
340 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) {
341 debug("%s: Could not format address for name %.100s: %s",
342 __func__, name, ssh_gai_strerror(gaierr));
343 goto fail;
344 }
345 if (strlcpy(caddr, addr, clen) >= clen) {
346 error("%s: host \"%s\" addr \"%s\" too long (max %lu)",
347 __func__, name, addr, (u_long)clen);
348 if (clen > 0)
349 *caddr = '\0';
350 fail:
351 freeaddrinfo(res);
352 return NULL;
353 }
354 return res;
355 }
356
357 /*
358 * Check whether the cname is a permitted replacement for the hostname
359 * and perform the replacement if it is.
360 * NB. this function must operate with a options having undefined members.
361 */
362 static int
check_follow_cname(int direct,char ** namep,const char * cname)363 check_follow_cname(int direct, char **namep, const char *cname)
364 {
365 int i;
366 struct allowed_cname *rule;
367
368 if (*cname == '\0' || options.num_permitted_cnames == 0 ||
369 strcmp(*namep, cname) == 0)
370 return 0;
371 if (options.canonicalize_hostname == SSH_CANONICALISE_NO)
372 return 0;
373 /*
374 * Don't attempt to canonicalize names that will be interpreted by
375 * a proxy or jump host unless the user specifically requests so.
376 */
377 if (!direct &&
378 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
379 return 0;
380 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname);
381 for (i = 0; i < options.num_permitted_cnames; i++) {
382 rule = options.permitted_cnames + i;
383 if (match_pattern_list(*namep, rule->source_list, 1) != 1 ||
384 match_pattern_list(cname, rule->target_list, 1) != 1)
385 continue;
386 verbose("Canonicalized DNS aliased hostname "
387 "\"%s\" => \"%s\"", *namep, cname);
388 free(*namep);
389 *namep = xstrdup(cname);
390 return 1;
391 }
392 return 0;
393 }
394
395 /*
396 * Attempt to resolve the supplied hostname after applying the user's
397 * canonicalization rules. Returns the address list for the host or NULL
398 * if no name was found after canonicalization.
399 * NB. this function must operate with a options having undefined members.
400 */
401 static struct addrinfo *
resolve_canonicalize(char ** hostp,int port)402 resolve_canonicalize(char **hostp, int port)
403 {
404 int i, direct, ndots;
405 char *cp, *fullhost, newname[NI_MAXHOST];
406 struct addrinfo *addrs;
407
408 /*
409 * Attempt to canonicalise addresses, regardless of
410 * whether hostname canonicalisation was requested
411 */
412 if ((addrs = resolve_addr(*hostp, port,
413 newname, sizeof(newname))) != NULL) {
414 debug2("%s: hostname %.100s is address", __func__, *hostp);
415 if (strcasecmp(*hostp, newname) != 0) {
416 debug2("%s: canonicalised address \"%s\" => \"%s\"",
417 __func__, *hostp, newname);
418 free(*hostp);
419 *hostp = xstrdup(newname);
420 }
421 return addrs;
422 }
423
424 /*
425 * If this looks like an address but didn't parse as one, it might
426 * be an address with an invalid interface scope. Skip further
427 * attempts at canonicalisation.
428 */
429 if (is_addr_fast(*hostp)) {
430 debug("%s: hostname %.100s is an unrecognised address",
431 __func__, *hostp);
432 return NULL;
433 }
434
435 if (options.canonicalize_hostname == SSH_CANONICALISE_NO)
436 return NULL;
437
438 /*
439 * Don't attempt to canonicalize names that will be interpreted by
440 * a proxy unless the user specifically requests so.
441 */
442 direct = option_clear_or_none(options.proxy_command) &&
443 options.jump_host == NULL;
444 if (!direct &&
445 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
446 return NULL;
447
448 /* If domain name is anchored, then resolve it now */
449 if ((*hostp)[strlen(*hostp) - 1] == '.') {
450 debug3("%s: name is fully qualified", __func__);
451 fullhost = xstrdup(*hostp);
452 if ((addrs = resolve_host(fullhost, port, 0,
453 newname, sizeof(newname))) != NULL)
454 goto found;
455 free(fullhost);
456 goto notfound;
457 }
458
459 /* Don't apply canonicalization to sufficiently-qualified hostnames */
460 ndots = 0;
461 for (cp = *hostp; *cp != '\0'; cp++) {
462 if (*cp == '.')
463 ndots++;
464 }
465 if (ndots > options.canonicalize_max_dots) {
466 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)",
467 __func__, *hostp, options.canonicalize_max_dots);
468 return NULL;
469 }
470 /* Attempt each supplied suffix */
471 for (i = 0; i < options.num_canonical_domains; i++) {
472 *newname = '\0';
473 xasprintf(&fullhost, "%s.%s.", *hostp,
474 options.canonical_domains[i]);
475 debug3("%s: attempting \"%s\" => \"%s\"", __func__,
476 *hostp, fullhost);
477 if ((addrs = resolve_host(fullhost, port, 0,
478 newname, sizeof(newname))) == NULL) {
479 free(fullhost);
480 continue;
481 }
482 found:
483 /* Remove trailing '.' */
484 fullhost[strlen(fullhost) - 1] = '\0';
485 /* Follow CNAME if requested */
486 if (!check_follow_cname(direct, &fullhost, newname)) {
487 debug("Canonicalized hostname \"%s\" => \"%s\"",
488 *hostp, fullhost);
489 }
490 free(*hostp);
491 *hostp = fullhost;
492 return addrs;
493 }
494 notfound:
495 if (!options.canonicalize_fallback_local)
496 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp);
497 debug2("%s: host %s not found in any suffix", __func__, *hostp);
498 return NULL;
499 }
500
501 /*
502 * Check the result of hostkey loading, ignoring some errors and
503 * fatal()ing for others.
504 */
505 static void
check_load(int r,const char * path,const char * message)506 check_load(int r, const char *path, const char *message)
507 {
508 switch (r) {
509 case 0:
510 break;
511 case SSH_ERR_INTERNAL_ERROR:
512 case SSH_ERR_ALLOC_FAIL:
513 fatal("load %s \"%s\": %s", message, path, ssh_err(r));
514 case SSH_ERR_SYSTEM_ERROR:
515 /* Ignore missing files */
516 if (errno == ENOENT)
517 break;
518 /* FALLTHROUGH */
519 default:
520 error("load %s \"%s\": %s", message, path, ssh_err(r));
521 break;
522 }
523 }
524
525 /*
526 * Read per-user configuration file. Ignore the system wide config
527 * file if the user specifies a config file on the command line.
528 */
529 static void
process_config_files(const char * host_name,struct passwd * pw,int final_pass,int * want_final_pass)530 process_config_files(const char *host_name, struct passwd *pw, int final_pass,
531 int *want_final_pass)
532 {
533 char buf[PATH_MAX];
534 int r;
535
536 if (config != NULL) {
537 if (strcasecmp(config, "none") != 0 &&
538 !read_config_file(config, pw, host, host_name, &options,
539 SSHCONF_USERCONF | (final_pass ? SSHCONF_FINAL : 0),
540 want_final_pass))
541 fatal("Can't open user config file %.100s: "
542 "%.100s", config, strerror(errno));
543 } else {
544 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
545 _PATH_SSH_USER_CONFFILE);
546 if (r > 0 && (size_t)r < sizeof(buf))
547 (void)read_config_file(buf, pw, host, host_name,
548 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF |
549 (final_pass ? SSHCONF_FINAL : 0), want_final_pass);
550
551 /* Read systemwide configuration file after user config. */
552 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw,
553 host, host_name, &options,
554 final_pass ? SSHCONF_FINAL : 0, want_final_pass);
555 }
556 }
557
558 /* Rewrite the port number in an addrinfo list of addresses */
559 static void
set_addrinfo_port(struct addrinfo * addrs,int port)560 set_addrinfo_port(struct addrinfo *addrs, int port)
561 {
562 struct addrinfo *addr;
563
564 for (addr = addrs; addr != NULL; addr = addr->ai_next) {
565 switch (addr->ai_family) {
566 case AF_INET:
567 ((struct sockaddr_in *)addr->ai_addr)->
568 sin_port = htons(port);
569 break;
570 case AF_INET6:
571 ((struct sockaddr_in6 *)addr->ai_addr)->
572 sin6_port = htons(port);
573 break;
574 }
575 }
576 }
577
578 /*
579 * Main program for the ssh client.
580 */
581 int
main(int ac,char ** av)582 main(int ac, char **av)
583 {
584 struct ssh *ssh = NULL;
585 int i, r, opt, exit_status, use_syslog, direct, timeout_ms;
586 int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0;
587 char *p, *cp, *line, *argv0, buf[PATH_MAX], *logfile;
588 char cname[NI_MAXHOST];
589 struct stat st;
590 struct passwd *pw;
591 extern int optind, optreset;
592 extern char *optarg;
593 struct Forward fwd;
594 struct addrinfo *addrs = NULL;
595 struct ssh_digest_ctx *md;
596 u_char conn_hash[SSH_DIGEST_MAX_LENGTH];
597
598 ssh_malloc_init(); /* must be called before any mallocs */
599 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
600 sanitise_stdfd();
601
602 __progname = ssh_get_progname(av[0]);
603
604 #ifndef HAVE_SETPROCTITLE
605 /* Prepare for later setproctitle emulation */
606 /* Save argv so it isn't clobbered by setproctitle() emulation */
607 saved_av = xcalloc(ac + 1, sizeof(*saved_av));
608 for (i = 0; i < ac; i++)
609 saved_av[i] = xstrdup(av[i]);
610 saved_av[i] = NULL;
611 compat_init_setproctitle(ac, av);
612 av = saved_av;
613 #endif
614
615 seed_rng();
616
617 /*
618 * Discard other fds that are hanging around. These can cause problem
619 * with backgrounded ssh processes started by ControlPersist.
620 */
621 closefrom(STDERR_FILENO + 1);
622
623 /* Get user data. */
624 pw = getpwuid(getuid());
625 if (!pw) {
626 logit("No user exists for uid %lu", (u_long)getuid());
627 exit(255);
628 }
629 /* Take a copy of the returned structure. */
630 pw = pwcopy(pw);
631
632 /*
633 * Set our umask to something reasonable, as some files are created
634 * with the default umask. This will make them world-readable but
635 * writable only by the owner, which is ok for all files for which we
636 * don't set the modes explicitly.
637 */
638 umask(022);
639
640 msetlocale();
641
642 /*
643 * Initialize option structure to indicate that no values have been
644 * set.
645 */
646 initialize_options(&options);
647
648 /*
649 * Prepare main ssh transport/connection structures
650 */
651 if ((ssh = ssh_alloc_session_state()) == NULL)
652 fatal("Couldn't allocate session state");
653 channel_init_channels(ssh);
654
655 /* Parse command-line arguments. */
656 host = NULL;
657 use_syslog = 0;
658 logfile = NULL;
659 argv0 = av[0];
660
661 again:
662 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
663 "AB:CD:E:F:GI:J:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) {
664 switch (opt) {
665 case '1':
666 fatal("SSH protocol v.1 is no longer supported");
667 break;
668 case '2':
669 /* Ignored */
670 break;
671 case '4':
672 options.address_family = AF_INET;
673 break;
674 case '6':
675 options.address_family = AF_INET6;
676 break;
677 case 'n':
678 stdin_null_flag = 1;
679 break;
680 case 'f':
681 fork_after_authentication_flag = 1;
682 stdin_null_flag = 1;
683 break;
684 case 'x':
685 options.forward_x11 = 0;
686 break;
687 case 'X':
688 options.forward_x11 = 1;
689 break;
690 case 'y':
691 use_syslog = 1;
692 break;
693 case 'E':
694 logfile = optarg;
695 break;
696 case 'G':
697 config_test = 1;
698 break;
699 case 'Y':
700 options.forward_x11 = 1;
701 options.forward_x11_trusted = 1;
702 break;
703 case 'g':
704 options.fwd_opts.gateway_ports = 1;
705 break;
706 case 'O':
707 if (options.stdio_forward_host != NULL)
708 fatal("Cannot specify multiplexing "
709 "command with -W");
710 else if (muxclient_command != 0)
711 fatal("Multiplexing command already specified");
712 if (strcmp(optarg, "check") == 0)
713 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
714 else if (strcmp(optarg, "forward") == 0)
715 muxclient_command = SSHMUX_COMMAND_FORWARD;
716 else if (strcmp(optarg, "exit") == 0)
717 muxclient_command = SSHMUX_COMMAND_TERMINATE;
718 else if (strcmp(optarg, "stop") == 0)
719 muxclient_command = SSHMUX_COMMAND_STOP;
720 else if (strcmp(optarg, "cancel") == 0)
721 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD;
722 else if (strcmp(optarg, "proxy") == 0)
723 muxclient_command = SSHMUX_COMMAND_PROXY;
724 else
725 fatal("Invalid multiplex command.");
726 break;
727 case 'P': /* deprecated */
728 break;
729 case 'Q':
730 cp = NULL;
731 if (strcmp(optarg, "cipher") == 0)
732 cp = cipher_alg_list('\n', 0);
733 else if (strcmp(optarg, "cipher-auth") == 0)
734 cp = cipher_alg_list('\n', 1);
735 else if (strcmp(optarg, "mac") == 0)
736 cp = mac_alg_list('\n');
737 else if (strcmp(optarg, "kex") == 0)
738 cp = kex_alg_list('\n');
739 else if (strcmp(optarg, "key") == 0)
740 cp = sshkey_alg_list(0, 0, 0, '\n');
741 else if (strcmp(optarg, "key-cert") == 0)
742 cp = sshkey_alg_list(1, 0, 0, '\n');
743 else if (strcmp(optarg, "key-plain") == 0)
744 cp = sshkey_alg_list(0, 1, 0, '\n');
745 else if (strcmp(optarg, "sig") == 0)
746 cp = sshkey_alg_list(0, 1, 1, '\n');
747 else if (strcmp(optarg, "protocol-version") == 0)
748 cp = xstrdup("2");
749 else if (strcmp(optarg, "help") == 0) {
750 cp = xstrdup(
751 "cipher\ncipher-auth\nkex\nkey\n"
752 "key-cert\nkey-plain\nmac\n"
753 "protocol-version\nsig");
754 }
755 if (cp == NULL)
756 fatal("Unsupported query \"%s\"", optarg);
757 printf("%s\n", cp);
758 free(cp);
759 exit(0);
760 break;
761 case 'a':
762 options.forward_agent = 0;
763 break;
764 case 'A':
765 options.forward_agent = 1;
766 break;
767 case 'k':
768 options.gss_deleg_creds = 0;
769 break;
770 case 'K':
771 options.gss_authentication = 1;
772 options.gss_deleg_creds = 1;
773 break;
774 case 'i':
775 p = tilde_expand_filename(optarg, getuid());
776 if (stat(p, &st) < 0)
777 fprintf(stderr, "Warning: Identity file %s "
778 "not accessible: %s.\n", p,
779 strerror(errno));
780 else
781 add_identity_file(&options, NULL, p, 1);
782 free(p);
783 break;
784 case 'I':
785 #ifdef ENABLE_PKCS11
786 free(options.pkcs11_provider);
787 options.pkcs11_provider = xstrdup(optarg);
788 #else
789 fprintf(stderr, "no support for PKCS#11.\n");
790 #endif
791 break;
792 case 'J':
793 if (options.jump_host != NULL)
794 fatal("Only a single -J option permitted");
795 if (options.proxy_command != NULL)
796 fatal("Cannot specify -J with ProxyCommand");
797 if (parse_jump(optarg, &options, 1) == -1)
798 fatal("Invalid -J argument");
799 options.proxy_command = xstrdup("none");
800 break;
801 case 't':
802 if (options.request_tty == REQUEST_TTY_YES)
803 options.request_tty = REQUEST_TTY_FORCE;
804 else
805 options.request_tty = REQUEST_TTY_YES;
806 break;
807 case 'v':
808 if (debug_flag == 0) {
809 debug_flag = 1;
810 options.log_level = SYSLOG_LEVEL_DEBUG1;
811 } else {
812 if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
813 debug_flag++;
814 options.log_level++;
815 }
816 }
817 break;
818 case 'V':
819 fprintf(stderr, "%s, %s\n",
820 SSH_RELEASE,
821 #ifdef WITH_OPENSSL
822 OpenSSL_version(OPENSSL_VERSION)
823 #else
824 "without OpenSSL"
825 #endif
826 );
827 if (opt == 'V')
828 exit(0);
829 break;
830 case 'w':
831 if (options.tun_open == -1)
832 options.tun_open = SSH_TUNMODE_DEFAULT;
833 options.tun_local = a2tun(optarg, &options.tun_remote);
834 if (options.tun_local == SSH_TUNID_ERR) {
835 fprintf(stderr,
836 "Bad tun device '%s'\n", optarg);
837 exit(255);
838 }
839 break;
840 case 'W':
841 if (options.stdio_forward_host != NULL)
842 fatal("stdio forward already specified");
843 if (muxclient_command != 0)
844 fatal("Cannot specify stdio forward with -O");
845 if (parse_forward(&fwd, optarg, 1, 0)) {
846 options.stdio_forward_host = fwd.listen_host;
847 options.stdio_forward_port = fwd.listen_port;
848 free(fwd.connect_host);
849 } else {
850 fprintf(stderr,
851 "Bad stdio forwarding specification '%s'\n",
852 optarg);
853 exit(255);
854 }
855 options.request_tty = REQUEST_TTY_NO;
856 no_shell_flag = 1;
857 break;
858 case 'q':
859 options.log_level = SYSLOG_LEVEL_QUIET;
860 break;
861 case 'e':
862 if (optarg[0] == '^' && optarg[2] == 0 &&
863 (u_char) optarg[1] >= 64 &&
864 (u_char) optarg[1] < 128)
865 options.escape_char = (u_char) optarg[1] & 31;
866 else if (strlen(optarg) == 1)
867 options.escape_char = (u_char) optarg[0];
868 else if (strcmp(optarg, "none") == 0)
869 options.escape_char = SSH_ESCAPECHAR_NONE;
870 else {
871 fprintf(stderr, "Bad escape character '%s'.\n",
872 optarg);
873 exit(255);
874 }
875 break;
876 case 'c':
877 if (!ciphers_valid(*optarg == '+' ?
878 optarg + 1 : optarg)) {
879 fprintf(stderr, "Unknown cipher type '%s'\n",
880 optarg);
881 exit(255);
882 }
883 free(options.ciphers);
884 options.ciphers = xstrdup(optarg);
885 break;
886 case 'm':
887 if (mac_valid(optarg)) {
888 free(options.macs);
889 options.macs = xstrdup(optarg);
890 } else {
891 fprintf(stderr, "Unknown mac type '%s'\n",
892 optarg);
893 exit(255);
894 }
895 break;
896 case 'M':
897 if (options.control_master == SSHCTL_MASTER_YES)
898 options.control_master = SSHCTL_MASTER_ASK;
899 else
900 options.control_master = SSHCTL_MASTER_YES;
901 break;
902 case 'p':
903 if (options.port == -1) {
904 options.port = a2port(optarg);
905 if (options.port <= 0) {
906 fprintf(stderr, "Bad port '%s'\n",
907 optarg);
908 exit(255);
909 }
910 }
911 break;
912 case 'l':
913 if (options.user == NULL)
914 options.user = optarg;
915 break;
916
917 case 'L':
918 if (parse_forward(&fwd, optarg, 0, 0))
919 add_local_forward(&options, &fwd);
920 else {
921 fprintf(stderr,
922 "Bad local forwarding specification '%s'\n",
923 optarg);
924 exit(255);
925 }
926 break;
927
928 case 'R':
929 if (parse_forward(&fwd, optarg, 0, 1) ||
930 parse_forward(&fwd, optarg, 1, 1)) {
931 add_remote_forward(&options, &fwd);
932 } else {
933 fprintf(stderr,
934 "Bad remote forwarding specification "
935 "'%s'\n", optarg);
936 exit(255);
937 }
938 break;
939
940 case 'D':
941 if (parse_forward(&fwd, optarg, 1, 0)) {
942 add_local_forward(&options, &fwd);
943 } else {
944 fprintf(stderr,
945 "Bad dynamic forwarding specification "
946 "'%s'\n", optarg);
947 exit(255);
948 }
949 break;
950
951 case 'C':
952 options.compression = 1;
953 break;
954 case 'N':
955 no_shell_flag = 1;
956 options.request_tty = REQUEST_TTY_NO;
957 break;
958 case 'T':
959 options.request_tty = REQUEST_TTY_NO;
960 break;
961 case 'o':
962 line = xstrdup(optarg);
963 if (process_config_line(&options, pw,
964 host ? host : "", host ? host : "", line,
965 "command-line", 0, NULL, SSHCONF_USERCONF) != 0)
966 exit(255);
967 free(line);
968 break;
969 case 's':
970 subsystem_flag = 1;
971 break;
972 case 'S':
973 free(options.control_path);
974 options.control_path = xstrdup(optarg);
975 break;
976 case 'b':
977 options.bind_address = optarg;
978 break;
979 case 'B':
980 options.bind_interface = optarg;
981 break;
982 case 'F':
983 config = optarg;
984 break;
985 default:
986 usage();
987 }
988 }
989
990 if (optind > 1 && strcmp(av[optind - 1], "--") == 0)
991 opt_terminated = 1;
992
993 ac -= optind;
994 av += optind;
995
996 if (ac > 0 && !host) {
997 int tport;
998 char *tuser;
999 switch (parse_ssh_uri(*av, &tuser, &host, &tport)) {
1000 case -1:
1001 usage();
1002 break;
1003 case 0:
1004 if (options.user == NULL) {
1005 options.user = tuser;
1006 tuser = NULL;
1007 }
1008 free(tuser);
1009 if (options.port == -1 && tport != -1)
1010 options.port = tport;
1011 break;
1012 default:
1013 p = xstrdup(*av);
1014 cp = strrchr(p, '@');
1015 if (cp != NULL) {
1016 if (cp == p)
1017 usage();
1018 if (options.user == NULL) {
1019 options.user = p;
1020 p = NULL;
1021 }
1022 *cp++ = '\0';
1023 host = xstrdup(cp);
1024 free(p);
1025 } else
1026 host = p;
1027 break;
1028 }
1029 if (ac > 1 && !opt_terminated) {
1030 optind = optreset = 1;
1031 goto again;
1032 }
1033 ac--, av++;
1034 }
1035
1036 /* Check that we got a host name. */
1037 if (!host)
1038 usage();
1039
1040 host_arg = xstrdup(host);
1041
1042 /* Initialize the command to execute on remote host. */
1043 if ((command = sshbuf_new()) == NULL)
1044 fatal("sshbuf_new failed");
1045
1046 /*
1047 * Save the command to execute on the remote host in a buffer. There
1048 * is no limit on the length of the command, except by the maximum
1049 * packet size. Also sets the tty flag if there is no command.
1050 */
1051 if (!ac) {
1052 /* No command specified - execute shell on a tty. */
1053 if (subsystem_flag) {
1054 fprintf(stderr,
1055 "You must specify a subsystem to invoke.\n");
1056 usage();
1057 }
1058 } else {
1059 /* A command has been specified. Store it into the buffer. */
1060 for (i = 0; i < ac; i++) {
1061 if ((r = sshbuf_putf(command, "%s%s",
1062 i ? " " : "", av[i])) != 0)
1063 fatal("%s: buffer error: %s",
1064 __func__, ssh_err(r));
1065 }
1066 }
1067
1068 /*
1069 * Initialize "log" output. Since we are the client all output
1070 * goes to stderr unless otherwise specified by -y or -E.
1071 */
1072 if (use_syslog && logfile != NULL)
1073 fatal("Can't specify both -y and -E");
1074 if (logfile != NULL)
1075 log_redirect_stderr_to(logfile);
1076 log_init(argv0,
1077 options.log_level == SYSLOG_LEVEL_NOT_SET ?
1078 SYSLOG_LEVEL_INFO : options.log_level,
1079 options.log_facility == SYSLOG_FACILITY_NOT_SET ?
1080 SYSLOG_FACILITY_USER : options.log_facility,
1081 !use_syslog);
1082
1083 if (debug_flag)
1084 logit("%s, %s", SSH_RELEASE,
1085 #ifdef WITH_OPENSSL
1086 OpenSSL_version(OPENSSL_VERSION)
1087 #else
1088 "without OpenSSL"
1089 #endif
1090 );
1091
1092 /* Parse the configuration files */
1093 process_config_files(host_arg, pw, 0, &want_final_pass);
1094 if (want_final_pass)
1095 debug("configuration requests final Match pass");
1096
1097 /* Hostname canonicalisation needs a few options filled. */
1098 fill_default_options_for_canonicalization(&options);
1099
1100 /* If the user has replaced the hostname then take it into use now */
1101 if (options.hostname != NULL) {
1102 /* NB. Please keep in sync with readconf.c:match_cfg_line() */
1103 cp = percent_expand(options.hostname,
1104 "h", host, (char *)NULL);
1105 free(host);
1106 host = cp;
1107 free(options.hostname);
1108 options.hostname = xstrdup(host);
1109 }
1110
1111 /* Don't lowercase addresses, they will be explicitly canonicalised */
1112 if ((was_addr = is_addr(host)) == 0)
1113 lowercase(host);
1114
1115 /*
1116 * Try to canonicalize if requested by configuration or the
1117 * hostname is an address.
1118 */
1119 if (options.canonicalize_hostname != SSH_CANONICALISE_NO || was_addr)
1120 addrs = resolve_canonicalize(&host, options.port);
1121
1122 /*
1123 * If CanonicalizePermittedCNAMEs have been specified but
1124 * other canonicalization did not happen (by not being requested
1125 * or by failing with fallback) then the hostname may still be changed
1126 * as a result of CNAME following.
1127 *
1128 * Try to resolve the bare hostname name using the system resolver's
1129 * usual search rules and then apply the CNAME follow rules.
1130 *
1131 * Skip the lookup if a ProxyCommand is being used unless the user
1132 * has specifically requested canonicalisation for this case via
1133 * CanonicalizeHostname=always
1134 */
1135 direct = option_clear_or_none(options.proxy_command) &&
1136 options.jump_host == NULL;
1137 if (addrs == NULL && options.num_permitted_cnames != 0 && (direct ||
1138 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) {
1139 if ((addrs = resolve_host(host, options.port,
1140 direct, cname, sizeof(cname))) == NULL) {
1141 /* Don't fatal proxied host names not in the DNS */
1142 if (direct)
1143 cleanup_exit(255); /* logged in resolve_host */
1144 } else
1145 check_follow_cname(direct, &host, cname);
1146 }
1147
1148 /*
1149 * If canonicalisation is enabled then re-parse the configuration
1150 * files as new stanzas may match.
1151 */
1152 if (options.canonicalize_hostname != 0 && !want_final_pass) {
1153 debug("hostname canonicalisation enabled, "
1154 "will re-parse configuration");
1155 want_final_pass = 1;
1156 }
1157
1158 if (want_final_pass) {
1159 debug("re-parsing configuration");
1160 free(options.hostname);
1161 options.hostname = xstrdup(host);
1162 process_config_files(host_arg, pw, 1, NULL);
1163 /*
1164 * Address resolution happens early with canonicalisation
1165 * enabled and the port number may have changed since, so
1166 * reset it in address list
1167 */
1168 if (addrs != NULL && options.port > 0)
1169 set_addrinfo_port(addrs, options.port);
1170 }
1171
1172 /* Fill configuration defaults. */
1173 fill_default_options(&options);
1174
1175 /*
1176 * If ProxyJump option specified, then construct a ProxyCommand now.
1177 */
1178 if (options.jump_host != NULL) {
1179 char port_s[8];
1180 const char *sshbin = argv0;
1181
1182 /*
1183 * Try to use SSH indicated by argv[0], but fall back to
1184 * "ssh" if it appears unavailable.
1185 */
1186 if (strchr(argv0, '/') != NULL && access(argv0, X_OK) != 0)
1187 sshbin = "ssh";
1188
1189 /* Consistency check */
1190 if (options.proxy_command != NULL)
1191 fatal("inconsistent options: ProxyCommand+ProxyJump");
1192 /* Never use FD passing for ProxyJump */
1193 options.proxy_use_fdpass = 0;
1194 snprintf(port_s, sizeof(port_s), "%d", options.jump_port);
1195 xasprintf(&options.proxy_command,
1196 "%s%s%s%s%s%s%s%s%s%s%.*s -W '[%%h]:%%p' %s",
1197 sshbin,
1198 /* Optional "-l user" argument if jump_user set */
1199 options.jump_user == NULL ? "" : " -l ",
1200 options.jump_user == NULL ? "" : options.jump_user,
1201 /* Optional "-p port" argument if jump_port set */
1202 options.jump_port <= 0 ? "" : " -p ",
1203 options.jump_port <= 0 ? "" : port_s,
1204 /* Optional additional jump hosts ",..." */
1205 options.jump_extra == NULL ? "" : " -J ",
1206 options.jump_extra == NULL ? "" : options.jump_extra,
1207 /* Optional "-F" argumment if -F specified */
1208 config == NULL ? "" : " -F ",
1209 config == NULL ? "" : config,
1210 /* Optional "-v" arguments if -v set */
1211 debug_flag ? " -" : "",
1212 debug_flag, "vvv",
1213 /* Mandatory hostname */
1214 options.jump_host);
1215 debug("Setting implicit ProxyCommand from ProxyJump: %s",
1216 options.proxy_command);
1217 }
1218
1219 if (options.port == 0)
1220 options.port = default_ssh_port();
1221 channel_set_af(ssh, options.address_family);
1222
1223 /* Tidy and check options */
1224 if (options.host_key_alias != NULL)
1225 lowercase(options.host_key_alias);
1226 if (options.proxy_command != NULL &&
1227 strcmp(options.proxy_command, "-") == 0 &&
1228 options.proxy_use_fdpass)
1229 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible");
1230 if (options.control_persist &&
1231 options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) {
1232 debug("UpdateHostKeys=ask is incompatible with ControlPersist; "
1233 "disabling");
1234 options.update_hostkeys = 0;
1235 }
1236 if (options.connection_attempts <= 0)
1237 fatal("Invalid number of ConnectionAttempts");
1238
1239 if (sshbuf_len(command) != 0 && options.remote_command != NULL)
1240 fatal("Cannot execute command-line and remote command.");
1241
1242 /* Cannot fork to background if no command. */
1243 if (fork_after_authentication_flag && sshbuf_len(command) == 0 &&
1244 options.remote_command == NULL && !no_shell_flag)
1245 fatal("Cannot fork into background without a command "
1246 "to execute.");
1247
1248 /* reinit */
1249 log_init(argv0, options.log_level, options.log_facility, !use_syslog);
1250
1251 if (options.request_tty == REQUEST_TTY_YES ||
1252 options.request_tty == REQUEST_TTY_FORCE)
1253 tty_flag = 1;
1254
1255 /* Allocate a tty by default if no command specified. */
1256 if (sshbuf_len(command) == 0 && options.remote_command == NULL)
1257 tty_flag = options.request_tty != REQUEST_TTY_NO;
1258
1259 /* Force no tty */
1260 if (options.request_tty == REQUEST_TTY_NO ||
1261 (muxclient_command && muxclient_command != SSHMUX_COMMAND_PROXY))
1262 tty_flag = 0;
1263 /* Do not allocate a tty if stdin is not a tty. */
1264 if ((!isatty(fileno(stdin)) || stdin_null_flag) &&
1265 options.request_tty != REQUEST_TTY_FORCE) {
1266 if (tty_flag)
1267 logit("Pseudo-terminal will not be allocated because "
1268 "stdin is not a terminal.");
1269 tty_flag = 0;
1270 }
1271
1272 if (options.user == NULL)
1273 options.user = xstrdup(pw->pw_name);
1274
1275 /* Set up strings used to percent_expand() arguments */
1276 if (gethostname(thishost, sizeof(thishost)) == -1)
1277 fatal("gethostname: %s", strerror(errno));
1278 strlcpy(shorthost, thishost, sizeof(shorthost));
1279 shorthost[strcspn(thishost, ".")] = '\0';
1280 snprintf(portstr, sizeof(portstr), "%d", options.port);
1281 snprintf(uidstr, sizeof(uidstr), "%llu",
1282 (unsigned long long)pw->pw_uid);
1283
1284 if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL ||
1285 ssh_digest_update(md, thishost, strlen(thishost)) < 0 ||
1286 ssh_digest_update(md, host, strlen(host)) < 0 ||
1287 ssh_digest_update(md, portstr, strlen(portstr)) < 0 ||
1288 ssh_digest_update(md, options.user, strlen(options.user)) < 0 ||
1289 ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0)
1290 fatal("%s: mux digest failed", __func__);
1291 ssh_digest_free(md);
1292 conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1));
1293
1294 /*
1295 * Expand tokens in arguments. NB. LocalCommand is expanded later,
1296 * after port-forwarding is set up, so it may pick up any local
1297 * tunnel interface name allocated.
1298 */
1299 if (options.remote_command != NULL) {
1300 debug3("expanding RemoteCommand: %s", options.remote_command);
1301 cp = options.remote_command;
1302 options.remote_command = percent_expand(cp,
1303 "C", conn_hash_hex,
1304 "L", shorthost,
1305 "d", pw->pw_dir,
1306 "h", host,
1307 "i", uidstr,
1308 "l", thishost,
1309 "n", host_arg,
1310 "p", portstr,
1311 "r", options.user,
1312 "u", pw->pw_name,
1313 (char *)NULL);
1314 debug3("expanded RemoteCommand: %s", options.remote_command);
1315 free(cp);
1316 if ((r = sshbuf_put(command, options.remote_command,
1317 strlen(options.remote_command))) != 0)
1318 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1319 }
1320
1321 if (options.control_path != NULL) {
1322 cp = tilde_expand_filename(options.control_path, getuid());
1323 free(options.control_path);
1324 options.control_path = percent_expand(cp,
1325 "C", conn_hash_hex,
1326 "L", shorthost,
1327 "h", host,
1328 "i", uidstr,
1329 "l", thishost,
1330 "n", host_arg,
1331 "p", portstr,
1332 "r", options.user,
1333 "u", pw->pw_name,
1334 "i", uidstr,
1335 (char *)NULL);
1336 free(cp);
1337 }
1338
1339 if (config_test) {
1340 dump_client_config(&options, host);
1341 exit(0);
1342 }
1343
1344 if (muxclient_command != 0 && options.control_path == NULL)
1345 fatal("No ControlPath specified for \"-O\" command");
1346 if (options.control_path != NULL) {
1347 int sock;
1348 if ((sock = muxclient(options.control_path)) >= 0) {
1349 ssh_packet_set_connection(ssh, sock, sock);
1350 ssh_packet_set_mux(ssh);
1351 goto skip_connect;
1352 }
1353 }
1354
1355 /*
1356 * If hostname canonicalisation was not enabled, then we may not
1357 * have yet resolved the hostname. Do so now.
1358 */
1359 if (addrs == NULL && options.proxy_command == NULL) {
1360 debug2("resolving \"%s\" port %d", host, options.port);
1361 if ((addrs = resolve_host(host, options.port, 1,
1362 cname, sizeof(cname))) == NULL)
1363 cleanup_exit(255); /* resolve_host logs the error */
1364 }
1365
1366 timeout_ms = options.connection_timeout * 1000;
1367
1368 /* Open a connection to the remote host. */
1369 if (ssh_connect(ssh, host, addrs, &hostaddr, options.port,
1370 options.address_family, options.connection_attempts,
1371 &timeout_ms, options.tcp_keep_alive) != 0)
1372 exit(255);
1373
1374 if (addrs != NULL)
1375 freeaddrinfo(addrs);
1376
1377 ssh_packet_set_timeout(ssh, options.server_alive_interval,
1378 options.server_alive_count_max);
1379
1380 if (timeout_ms > 0)
1381 debug3("timeout: %d ms remain after connect", timeout_ms);
1382
1383 /*
1384 * If we successfully made the connection and we have hostbased auth
1385 * enabled, load the public keys so we can later use the ssh-keysign
1386 * helper to sign challenges.
1387 */
1388 sensitive_data.nkeys = 0;
1389 sensitive_data.keys = NULL;
1390 if (options.hostbased_authentication) {
1391 sensitive_data.nkeys = 10;
1392 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
1393 sizeof(struct sshkey));
1394
1395 /* XXX check errors? */
1396 #define L_PUBKEY(p,o) do { \
1397 if ((o) >= sensitive_data.nkeys) \
1398 fatal("%s pubkey out of array bounds", __func__); \
1399 check_load(sshkey_load_public(p, &(sensitive_data.keys[o]), NULL), \
1400 p, "pubkey"); \
1401 } while (0)
1402 #define L_CERT(p,o) do { \
1403 if ((o) >= sensitive_data.nkeys) \
1404 fatal("%s cert out of array bounds", __func__); \
1405 check_load(sshkey_load_cert(p, &(sensitive_data.keys[o])), p, "cert"); \
1406 } while (0)
1407
1408 if (options.hostbased_authentication == 1) {
1409 L_CERT(_PATH_HOST_ECDSA_KEY_FILE, 0);
1410 L_CERT(_PATH_HOST_ED25519_KEY_FILE, 1);
1411 L_CERT(_PATH_HOST_RSA_KEY_FILE, 2);
1412 L_CERT(_PATH_HOST_DSA_KEY_FILE, 3);
1413 L_PUBKEY(_PATH_HOST_ECDSA_KEY_FILE, 4);
1414 L_PUBKEY(_PATH_HOST_ED25519_KEY_FILE, 5);
1415 L_PUBKEY(_PATH_HOST_RSA_KEY_FILE, 6);
1416 L_PUBKEY(_PATH_HOST_DSA_KEY_FILE, 7);
1417 L_CERT(_PATH_HOST_XMSS_KEY_FILE, 8);
1418 L_PUBKEY(_PATH_HOST_XMSS_KEY_FILE, 9);
1419 }
1420 }
1421
1422 /* Create ~/.ssh * directory if it doesn't already exist. */
1423 if (config == NULL) {
1424 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir,
1425 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
1426 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) {
1427 #ifdef WITH_SELINUX
1428 ssh_selinux_setfscreatecon(buf);
1429 #endif
1430 if (mkdir(buf, 0700) < 0)
1431 error("Could not create directory '%.200s'.",
1432 buf);
1433 #ifdef WITH_SELINUX
1434 ssh_selinux_setfscreatecon(NULL);
1435 #endif
1436 }
1437 }
1438 /* load options.identity_files */
1439 load_public_identity_files(pw);
1440
1441 /* optionally set the SSH_AUTHSOCKET_ENV_NAME variable */
1442 if (options.identity_agent &&
1443 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) {
1444 if (strcmp(options.identity_agent, "none") == 0) {
1445 unsetenv(SSH_AUTHSOCKET_ENV_NAME);
1446 } else {
1447 p = tilde_expand_filename(options.identity_agent,
1448 getuid());
1449 cp = percent_expand(p,
1450 "d", pw->pw_dir,
1451 "h", host,
1452 "i", uidstr,
1453 "l", thishost,
1454 "r", options.user,
1455 "u", pw->pw_name,
1456 (char *)NULL);
1457 free(p);
1458 /*
1459 * If identity_agent represents an environment variable
1460 * then recheck that it is valid (since processing with
1461 * percent_expand() may have changed it) and substitute
1462 * its value.
1463 */
1464 if (cp[0] == '$') {
1465 if (!valid_env_name(cp + 1)) {
1466 fatal("Invalid IdentityAgent "
1467 "environment variable name %s", cp);
1468 }
1469 if ((p = getenv(cp + 1)) == NULL)
1470 unsetenv(SSH_AUTHSOCKET_ENV_NAME);
1471 else
1472 setenv(SSH_AUTHSOCKET_ENV_NAME, p, 1);
1473 } else {
1474 /* identity_agent specifies a path directly */
1475 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1);
1476 }
1477 free(cp);
1478 }
1479 }
1480
1481 /* Expand ~ in known host file names. */
1482 tilde_expand_paths(options.system_hostfiles,
1483 options.num_system_hostfiles);
1484 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles);
1485
1486 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
1487 signal(SIGCHLD, main_sigchld_handler);
1488
1489 /* Log into the remote system. Never returns if the login fails. */
1490 ssh_login(ssh, &sensitive_data, host, (struct sockaddr *)&hostaddr,
1491 options.port, pw, timeout_ms);
1492
1493 if (ssh_packet_connection_is_on_socket(ssh)) {
1494 verbose("Authenticated to %s ([%s]:%d).", host,
1495 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1496 } else {
1497 verbose("Authenticated to %s (via proxy).", host);
1498 }
1499
1500 /* We no longer need the private host keys. Clear them now. */
1501 if (sensitive_data.nkeys != 0) {
1502 for (i = 0; i < sensitive_data.nkeys; i++) {
1503 if (sensitive_data.keys[i] != NULL) {
1504 /* Destroys contents safely */
1505 debug3("clear hostkey %d", i);
1506 sshkey_free(sensitive_data.keys[i]);
1507 sensitive_data.keys[i] = NULL;
1508 }
1509 }
1510 free(sensitive_data.keys);
1511 }
1512 for (i = 0; i < options.num_identity_files; i++) {
1513 free(options.identity_files[i]);
1514 options.identity_files[i] = NULL;
1515 if (options.identity_keys[i]) {
1516 sshkey_free(options.identity_keys[i]);
1517 options.identity_keys[i] = NULL;
1518 }
1519 }
1520 for (i = 0; i < options.num_certificate_files; i++) {
1521 free(options.certificate_files[i]);
1522 options.certificate_files[i] = NULL;
1523 }
1524
1525 skip_connect:
1526 exit_status = ssh_session2(ssh, pw);
1527 ssh_packet_close(ssh);
1528
1529 if (options.control_path != NULL && muxserver_sock != -1)
1530 unlink(options.control_path);
1531
1532 /* Kill ProxyCommand if it is running. */
1533 ssh_kill_proxy_command();
1534
1535 return exit_status;
1536 }
1537
1538 static void
control_persist_detach(void)1539 control_persist_detach(void)
1540 {
1541 pid_t pid;
1542 int devnull, keep_stderr;
1543
1544 debug("%s: backgrounding master process", __func__);
1545
1546 /*
1547 * master (current process) into the background, and make the
1548 * foreground process a client of the backgrounded master.
1549 */
1550 switch ((pid = fork())) {
1551 case -1:
1552 fatal("%s: fork: %s", __func__, strerror(errno));
1553 case 0:
1554 /* Child: master process continues mainloop */
1555 break;
1556 default:
1557 /* Parent: set up mux slave to connect to backgrounded master */
1558 debug2("%s: background process is %ld", __func__, (long)pid);
1559 stdin_null_flag = ostdin_null_flag;
1560 options.request_tty = orequest_tty;
1561 tty_flag = otty_flag;
1562 close(muxserver_sock);
1563 muxserver_sock = -1;
1564 options.control_master = SSHCTL_MASTER_NO;
1565 muxclient(options.control_path);
1566 /* muxclient() doesn't return on success. */
1567 fatal("Failed to connect to new control master");
1568 }
1569 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
1570 error("%s: open(\"/dev/null\"): %s", __func__,
1571 strerror(errno));
1572 } else {
1573 keep_stderr = log_is_on_stderr() && debug_flag;
1574 if (dup2(devnull, STDIN_FILENO) == -1 ||
1575 dup2(devnull, STDOUT_FILENO) == -1 ||
1576 (!keep_stderr && dup2(devnull, STDERR_FILENO) == -1))
1577 error("%s: dup2: %s", __func__, strerror(errno));
1578 if (devnull > STDERR_FILENO)
1579 close(devnull);
1580 }
1581 daemon(1, 1);
1582 setproctitle("%s [mux]", options.control_path);
1583 }
1584
1585 /* Do fork() after authentication. Used by "ssh -f" */
1586 static void
fork_postauth(void)1587 fork_postauth(void)
1588 {
1589 if (need_controlpersist_detach)
1590 control_persist_detach();
1591 debug("forking to background");
1592 fork_after_authentication_flag = 0;
1593 if (daemon(1, 1) < 0)
1594 fatal("daemon() failed: %.200s", strerror(errno));
1595 }
1596
1597 /* Callback for remote forward global requests */
1598 static void
ssh_confirm_remote_forward(struct ssh * ssh,int type,u_int32_t seq,void * ctxt)1599 ssh_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt)
1600 {
1601 struct Forward *rfwd = (struct Forward *)ctxt;
1602 u_int port;
1603 int r;
1604
1605 /* XXX verbose() on failure? */
1606 debug("remote forward %s for: listen %s%s%d, connect %s:%d",
1607 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1608 rfwd->listen_path ? rfwd->listen_path :
1609 rfwd->listen_host ? rfwd->listen_host : "",
1610 (rfwd->listen_path || rfwd->listen_host) ? ":" : "",
1611 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path :
1612 rfwd->connect_host, rfwd->connect_port);
1613 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) {
1614 if (type == SSH2_MSG_REQUEST_SUCCESS) {
1615 if ((r = sshpkt_get_u32(ssh, &port)) != 0)
1616 fatal("%s: %s", __func__, ssh_err(r));
1617 if (port > 65535) {
1618 error("Invalid allocated port %u for remote "
1619 "forward to %s:%d", port,
1620 rfwd->connect_host, rfwd->connect_port);
1621 /* Ensure failure processing runs below */
1622 type = SSH2_MSG_REQUEST_FAILURE;
1623 channel_update_permission(ssh,
1624 rfwd->handle, -1);
1625 } else {
1626 rfwd->allocated_port = (int)port;
1627 logit("Allocated port %u for remote "
1628 "forward to %s:%d",
1629 rfwd->allocated_port, rfwd->connect_host,
1630 rfwd->connect_port);
1631 channel_update_permission(ssh,
1632 rfwd->handle, rfwd->allocated_port);
1633 }
1634 } else {
1635 channel_update_permission(ssh, rfwd->handle, -1);
1636 }
1637 }
1638
1639 if (type == SSH2_MSG_REQUEST_FAILURE) {
1640 if (options.exit_on_forward_failure) {
1641 if (rfwd->listen_path != NULL)
1642 fatal("Error: remote port forwarding failed "
1643 "for listen path %s", rfwd->listen_path);
1644 else
1645 fatal("Error: remote port forwarding failed "
1646 "for listen port %d", rfwd->listen_port);
1647 } else {
1648 if (rfwd->listen_path != NULL)
1649 logit("Warning: remote port forwarding failed "
1650 "for listen path %s", rfwd->listen_path);
1651 else
1652 logit("Warning: remote port forwarding failed "
1653 "for listen port %d", rfwd->listen_port);
1654 }
1655 }
1656 if (++remote_forward_confirms_received == options.num_remote_forwards) {
1657 debug("All remote forwarding requests processed");
1658 if (fork_after_authentication_flag)
1659 fork_postauth();
1660 }
1661 }
1662
1663 static void
client_cleanup_stdio_fwd(struct ssh * ssh,int id,void * arg)1664 client_cleanup_stdio_fwd(struct ssh *ssh, int id, void *arg)
1665 {
1666 debug("stdio forwarding: done");
1667 cleanup_exit(0);
1668 }
1669
1670 static void
ssh_stdio_confirm(struct ssh * ssh,int id,int success,void * arg)1671 ssh_stdio_confirm(struct ssh *ssh, int id, int success, void *arg)
1672 {
1673 if (!success)
1674 fatal("stdio forwarding failed");
1675 }
1676
1677 static void
ssh_init_stdio_forwarding(struct ssh * ssh)1678 ssh_init_stdio_forwarding(struct ssh *ssh)
1679 {
1680 Channel *c;
1681 int in, out;
1682
1683 if (options.stdio_forward_host == NULL)
1684 return;
1685
1686 debug3("%s: %s:%d", __func__, options.stdio_forward_host,
1687 options.stdio_forward_port);
1688
1689 if ((in = dup(STDIN_FILENO)) < 0 ||
1690 (out = dup(STDOUT_FILENO)) < 0)
1691 fatal("channel_connect_stdio_fwd: dup() in/out failed");
1692 if ((c = channel_connect_stdio_fwd(ssh, options.stdio_forward_host,
1693 options.stdio_forward_port, in, out)) == NULL)
1694 fatal("%s: channel_connect_stdio_fwd failed", __func__);
1695 channel_register_cleanup(ssh, c->self, client_cleanup_stdio_fwd, 0);
1696 channel_register_open_confirm(ssh, c->self, ssh_stdio_confirm, NULL);
1697 }
1698
1699 static void
ssh_init_forwarding(struct ssh * ssh,char ** ifname)1700 ssh_init_forwarding(struct ssh *ssh, char **ifname)
1701 {
1702 int success = 0;
1703 int i;
1704
1705 /* Initiate local TCP/IP port forwardings. */
1706 for (i = 0; i < options.num_local_forwards; i++) {
1707 debug("Local connections to %.200s:%d forwarded to remote "
1708 "address %.200s:%d",
1709 (options.local_forwards[i].listen_path != NULL) ?
1710 options.local_forwards[i].listen_path :
1711 (options.local_forwards[i].listen_host == NULL) ?
1712 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1713 options.local_forwards[i].listen_host,
1714 options.local_forwards[i].listen_port,
1715 (options.local_forwards[i].connect_path != NULL) ?
1716 options.local_forwards[i].connect_path :
1717 options.local_forwards[i].connect_host,
1718 options.local_forwards[i].connect_port);
1719 success += channel_setup_local_fwd_listener(ssh,
1720 &options.local_forwards[i], &options.fwd_opts);
1721 }
1722 if (i > 0 && success != i && options.exit_on_forward_failure)
1723 fatal("Could not request local forwarding.");
1724 if (i > 0 && success == 0)
1725 error("Could not request local forwarding.");
1726
1727 /* Initiate remote TCP/IP port forwardings. */
1728 for (i = 0; i < options.num_remote_forwards; i++) {
1729 debug("Remote connections from %.200s:%d forwarded to "
1730 "local address %.200s:%d",
1731 (options.remote_forwards[i].listen_path != NULL) ?
1732 options.remote_forwards[i].listen_path :
1733 (options.remote_forwards[i].listen_host == NULL) ?
1734 "LOCALHOST" : options.remote_forwards[i].listen_host,
1735 options.remote_forwards[i].listen_port,
1736 (options.remote_forwards[i].connect_path != NULL) ?
1737 options.remote_forwards[i].connect_path :
1738 options.remote_forwards[i].connect_host,
1739 options.remote_forwards[i].connect_port);
1740 options.remote_forwards[i].handle =
1741 channel_request_remote_forwarding(ssh,
1742 &options.remote_forwards[i]);
1743 if (options.remote_forwards[i].handle < 0) {
1744 if (options.exit_on_forward_failure)
1745 fatal("Could not request remote forwarding.");
1746 else
1747 logit("Warning: Could not request remote "
1748 "forwarding.");
1749 } else {
1750 client_register_global_confirm(
1751 ssh_confirm_remote_forward,
1752 &options.remote_forwards[i]);
1753 }
1754 }
1755
1756 /* Initiate tunnel forwarding. */
1757 if (options.tun_open != SSH_TUNMODE_NO) {
1758 if ((*ifname = client_request_tun_fwd(ssh,
1759 options.tun_open, options.tun_local,
1760 options.tun_remote)) == NULL) {
1761 if (options.exit_on_forward_failure)
1762 fatal("Could not request tunnel forwarding.");
1763 else
1764 error("Could not request tunnel forwarding.");
1765 }
1766 }
1767 }
1768
1769 static void
check_agent_present(void)1770 check_agent_present(void)
1771 {
1772 int r;
1773
1774 if (options.forward_agent) {
1775 /* Clear agent forwarding if we don't have an agent. */
1776 if ((r = ssh_get_authentication_socket(NULL)) != 0) {
1777 options.forward_agent = 0;
1778 if (r != SSH_ERR_AGENT_NOT_PRESENT)
1779 debug("ssh_get_authentication_socket: %s",
1780 ssh_err(r));
1781 }
1782 }
1783 }
1784
1785 static void
ssh_session2_setup(struct ssh * ssh,int id,int success,void * arg)1786 ssh_session2_setup(struct ssh *ssh, int id, int success, void *arg)
1787 {
1788 extern char **environ;
1789 const char *display;
1790 int r, interactive = tty_flag;
1791 char *proto = NULL, *data = NULL;
1792
1793 if (!success)
1794 return; /* No need for error message, channels code sens one */
1795
1796 display = getenv("DISPLAY");
1797 if (display == NULL && options.forward_x11)
1798 debug("X11 forwarding requested but DISPLAY not set");
1799 if (options.forward_x11 && client_x11_get_proto(ssh, display,
1800 options.xauth_location, options.forward_x11_trusted,
1801 options.forward_x11_timeout, &proto, &data) == 0) {
1802 /* Request forwarding with authentication spoofing. */
1803 debug("Requesting X11 forwarding with authentication "
1804 "spoofing.");
1805 x11_request_forwarding_with_spoofing(ssh, id, display, proto,
1806 data, 1);
1807 client_expect_confirm(ssh, id, "X11 forwarding", CONFIRM_WARN);
1808 /* XXX exit_on_forward_failure */
1809 interactive = 1;
1810 }
1811
1812 check_agent_present();
1813 if (options.forward_agent) {
1814 debug("Requesting authentication agent forwarding.");
1815 channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0);
1816 if ((r = sshpkt_send(ssh)) != 0)
1817 fatal("%s: %s", __func__, ssh_err(r));
1818 }
1819
1820 /* Tell the packet module whether this is an interactive session. */
1821 ssh_packet_set_interactive(ssh, interactive,
1822 options.ip_qos_interactive, options.ip_qos_bulk);
1823
1824 client_session2_setup(ssh, id, tty_flag, subsystem_flag, getenv("TERM"),
1825 NULL, fileno(stdin), command, environ);
1826 }
1827
1828 /* open new channel for a session */
1829 static int
ssh_session2_open(struct ssh * ssh)1830 ssh_session2_open(struct ssh *ssh)
1831 {
1832 Channel *c;
1833 int window, packetmax, in, out, err;
1834
1835 if (stdin_null_flag) {
1836 in = open(_PATH_DEVNULL, O_RDONLY);
1837 } else {
1838 in = dup(STDIN_FILENO);
1839 }
1840 out = dup(STDOUT_FILENO);
1841 err = dup(STDERR_FILENO);
1842
1843 if (in < 0 || out < 0 || err < 0)
1844 fatal("dup() in/out/err failed");
1845
1846 /* enable nonblocking unless tty */
1847 if (!isatty(in))
1848 set_nonblock(in);
1849 if (!isatty(out))
1850 set_nonblock(out);
1851 if (!isatty(err))
1852 set_nonblock(err);
1853
1854 window = CHAN_SES_WINDOW_DEFAULT;
1855 packetmax = CHAN_SES_PACKET_DEFAULT;
1856 if (tty_flag) {
1857 window >>= 1;
1858 packetmax >>= 1;
1859 }
1860 c = channel_new(ssh,
1861 "session", SSH_CHANNEL_OPENING, in, out, err,
1862 window, packetmax, CHAN_EXTENDED_WRITE,
1863 "client-session", /*nonblock*/0);
1864
1865 debug3("%s: channel_new: %d", __func__, c->self);
1866
1867 channel_send_open(ssh, c->self);
1868 if (!no_shell_flag)
1869 channel_register_open_confirm(ssh, c->self,
1870 ssh_session2_setup, NULL);
1871
1872 return c->self;
1873 }
1874
1875 static int
ssh_session2(struct ssh * ssh,struct passwd * pw)1876 ssh_session2(struct ssh *ssh, struct passwd *pw)
1877 {
1878 int r, devnull, id = -1;
1879 char *cp, *tun_fwd_ifname = NULL;
1880
1881 /* XXX should be pre-session */
1882 if (!options.control_persist)
1883 ssh_init_stdio_forwarding(ssh);
1884
1885 ssh_init_forwarding(ssh, &tun_fwd_ifname);
1886
1887 if (options.local_command != NULL) {
1888 debug3("expanding LocalCommand: %s", options.local_command);
1889 cp = options.local_command;
1890 options.local_command = percent_expand(cp,
1891 "C", conn_hash_hex,
1892 "L", shorthost,
1893 "d", pw->pw_dir,
1894 "h", host,
1895 "i", uidstr,
1896 "l", thishost,
1897 "n", host_arg,
1898 "p", portstr,
1899 "r", options.user,
1900 "u", pw->pw_name,
1901 "T", tun_fwd_ifname == NULL ? "NONE" : tun_fwd_ifname,
1902 (char *)NULL);
1903 debug3("expanded LocalCommand: %s", options.local_command);
1904 free(cp);
1905 }
1906
1907 /* Start listening for multiplex clients */
1908 if (!ssh_packet_get_mux(ssh))
1909 muxserver_listen(ssh);
1910
1911 /*
1912 * If we are in control persist mode and have a working mux listen
1913 * socket, then prepare to background ourselves and have a foreground
1914 * client attach as a control slave.
1915 * NB. we must save copies of the flags that we override for
1916 * the backgrounding, since we defer attachment of the slave until
1917 * after the connection is fully established (in particular,
1918 * async rfwd replies have been received for ExitOnForwardFailure).
1919 */
1920 if (options.control_persist && muxserver_sock != -1) {
1921 ostdin_null_flag = stdin_null_flag;
1922 ono_shell_flag = no_shell_flag;
1923 orequest_tty = options.request_tty;
1924 otty_flag = tty_flag;
1925 stdin_null_flag = 1;
1926 no_shell_flag = 1;
1927 tty_flag = 0;
1928 if (!fork_after_authentication_flag)
1929 need_controlpersist_detach = 1;
1930 fork_after_authentication_flag = 1;
1931 }
1932 /*
1933 * ControlPersist mux listen socket setup failed, attempt the
1934 * stdio forward setup that we skipped earlier.
1935 */
1936 if (options.control_persist && muxserver_sock == -1)
1937 ssh_init_stdio_forwarding(ssh);
1938
1939 if (!no_shell_flag)
1940 id = ssh_session2_open(ssh);
1941 else {
1942 ssh_packet_set_interactive(ssh,
1943 options.control_master == SSHCTL_MASTER_NO,
1944 options.ip_qos_interactive, options.ip_qos_bulk);
1945 }
1946
1947 /* If we don't expect to open a new session, then disallow it */
1948 if (options.control_master == SSHCTL_MASTER_NO &&
1949 (datafellows & SSH_NEW_OPENSSH)) {
1950 debug("Requesting no-more-sessions@openssh.com");
1951 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
1952 (r = sshpkt_put_cstring(ssh,
1953 "no-more-sessions@openssh.com")) != 0 ||
1954 (r = sshpkt_put_u8(ssh, 0)) != 0 ||
1955 (r = sshpkt_send(ssh)) != 0)
1956 fatal("%s: %s", __func__, ssh_err(r));
1957 }
1958
1959 /* Execute a local command */
1960 if (options.local_command != NULL &&
1961 options.permit_local_command)
1962 ssh_local_cmd(options.local_command);
1963
1964 /*
1965 * stdout is now owned by the session channel; clobber it here
1966 * so future channel closes are propagated to the local fd.
1967 * NB. this can only happen after LocalCommand has completed,
1968 * as it may want to write to stdout.
1969 */
1970 if (!need_controlpersist_detach) {
1971 if ((devnull = open(_PATH_DEVNULL, O_WRONLY)) == -1)
1972 error("%s: open %s: %s", __func__,
1973 _PATH_DEVNULL, strerror(errno));
1974 if (dup2(devnull, STDOUT_FILENO) < 0)
1975 fatal("%s: dup2() stdout failed", __func__);
1976 if (devnull > STDERR_FILENO)
1977 close(devnull);
1978 }
1979
1980 /*
1981 * If requested and we are not interested in replies to remote
1982 * forwarding requests, then let ssh continue in the background.
1983 */
1984 if (fork_after_authentication_flag) {
1985 if (options.exit_on_forward_failure &&
1986 options.num_remote_forwards > 0) {
1987 debug("deferring postauth fork until remote forward "
1988 "confirmation received");
1989 } else
1990 fork_postauth();
1991 }
1992
1993 return client_loop(ssh, tty_flag, tty_flag ?
1994 options.escape_char : SSH_ESCAPECHAR_NONE, id);
1995 }
1996
1997 /* Loads all IdentityFile and CertificateFile keys */
1998 static void
load_public_identity_files(struct passwd * pw)1999 load_public_identity_files(struct passwd *pw)
2000 {
2001 char *filename, *cp;
2002 struct sshkey *public;
2003 int i;
2004 u_int n_ids, n_certs;
2005 char *identity_files[SSH_MAX_IDENTITY_FILES];
2006 struct sshkey *identity_keys[SSH_MAX_IDENTITY_FILES];
2007 int identity_file_userprovided[SSH_MAX_IDENTITY_FILES];
2008 char *certificate_files[SSH_MAX_CERTIFICATE_FILES];
2009 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES];
2010 int certificate_file_userprovided[SSH_MAX_CERTIFICATE_FILES];
2011 #ifdef ENABLE_PKCS11
2012 struct sshkey **keys;
2013 int nkeys;
2014 #endif /* PKCS11 */
2015
2016 n_ids = n_certs = 0;
2017 memset(identity_files, 0, sizeof(identity_files));
2018 memset(identity_keys, 0, sizeof(identity_keys));
2019 memset(identity_file_userprovided, 0,
2020 sizeof(identity_file_userprovided));
2021 memset(certificate_files, 0, sizeof(certificate_files));
2022 memset(certificates, 0, sizeof(certificates));
2023 memset(certificate_file_userprovided, 0,
2024 sizeof(certificate_file_userprovided));
2025
2026 #ifdef ENABLE_PKCS11
2027 if (options.pkcs11_provider != NULL &&
2028 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
2029 (pkcs11_init(!options.batch_mode) == 0) &&
2030 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL,
2031 &keys)) > 0) {
2032 for (i = 0; i < nkeys; i++) {
2033 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
2034 sshkey_free(keys[i]);
2035 continue;
2036 }
2037 identity_keys[n_ids] = keys[i];
2038 identity_files[n_ids] =
2039 xstrdup(options.pkcs11_provider); /* XXX */
2040 n_ids++;
2041 }
2042 free(keys);
2043 }
2044 #endif /* ENABLE_PKCS11 */
2045 for (i = 0; i < options.num_identity_files; i++) {
2046 if (n_ids >= SSH_MAX_IDENTITY_FILES ||
2047 strcasecmp(options.identity_files[i], "none") == 0) {
2048 free(options.identity_files[i]);
2049 options.identity_files[i] = NULL;
2050 continue;
2051 }
2052 cp = tilde_expand_filename(options.identity_files[i], getuid());
2053 filename = percent_expand(cp, "d", pw->pw_dir,
2054 "u", pw->pw_name, "l", thishost, "h", host,
2055 "r", options.user, (char *)NULL);
2056 free(cp);
2057 check_load(sshkey_load_public(filename, &public, NULL),
2058 filename, "pubkey");
2059 debug("identity file %s type %d", filename,
2060 public ? public->type : -1);
2061 free(options.identity_files[i]);
2062 identity_files[n_ids] = filename;
2063 identity_keys[n_ids] = public;
2064 identity_file_userprovided[n_ids] =
2065 options.identity_file_userprovided[i];
2066 if (++n_ids >= SSH_MAX_IDENTITY_FILES)
2067 continue;
2068
2069 /*
2070 * If no certificates have been explicitly listed then try
2071 * to add the default certificate variant too.
2072 */
2073 if (options.num_certificate_files != 0)
2074 continue;
2075 xasprintf(&cp, "%s-cert", filename);
2076 check_load(sshkey_load_public(cp, &public, NULL),
2077 filename, "pubkey");
2078 debug("identity file %s type %d", cp,
2079 public ? public->type : -1);
2080 if (public == NULL) {
2081 free(cp);
2082 continue;
2083 }
2084 if (!sshkey_is_cert(public)) {
2085 debug("%s: key %s type %s is not a certificate",
2086 __func__, cp, sshkey_type(public));
2087 sshkey_free(public);
2088 free(cp);
2089 continue;
2090 }
2091 /* NB. leave filename pointing to private key */
2092 identity_files[n_ids] = xstrdup(filename);
2093 identity_keys[n_ids] = public;
2094 identity_file_userprovided[n_ids] =
2095 options.identity_file_userprovided[i];
2096 n_ids++;
2097 }
2098
2099 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES)
2100 fatal("%s: too many certificates", __func__);
2101 for (i = 0; i < options.num_certificate_files; i++) {
2102 cp = tilde_expand_filename(options.certificate_files[i],
2103 getuid());
2104 filename = percent_expand(cp,
2105 "d", pw->pw_dir,
2106 "h", host,
2107 "i", uidstr,
2108 "l", thishost,
2109 "r", options.user,
2110 "u", pw->pw_name,
2111 (char *)NULL);
2112 free(cp);
2113
2114 check_load(sshkey_load_public(filename, &public, NULL),
2115 filename, "certificate");
2116 debug("certificate file %s type %d", filename,
2117 public ? public->type : -1);
2118 free(options.certificate_files[i]);
2119 options.certificate_files[i] = NULL;
2120 if (public == NULL) {
2121 free(filename);
2122 continue;
2123 }
2124 if (!sshkey_is_cert(public)) {
2125 debug("%s: key %s type %s is not a certificate",
2126 __func__, filename, sshkey_type(public));
2127 sshkey_free(public);
2128 free(filename);
2129 continue;
2130 }
2131 certificate_files[n_certs] = filename;
2132 certificates[n_certs] = public;
2133 certificate_file_userprovided[n_certs] =
2134 options.certificate_file_userprovided[i];
2135 ++n_certs;
2136 }
2137
2138 options.num_identity_files = n_ids;
2139 memcpy(options.identity_files, identity_files, sizeof(identity_files));
2140 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys));
2141 memcpy(options.identity_file_userprovided,
2142 identity_file_userprovided, sizeof(identity_file_userprovided));
2143
2144 options.num_certificate_files = n_certs;
2145 memcpy(options.certificate_files,
2146 certificate_files, sizeof(certificate_files));
2147 memcpy(options.certificates, certificates, sizeof(certificates));
2148 memcpy(options.certificate_file_userprovided,
2149 certificate_file_userprovided,
2150 sizeof(certificate_file_userprovided));
2151 }
2152
2153 static void
main_sigchld_handler(int sig)2154 main_sigchld_handler(int sig)
2155 {
2156 int save_errno = errno;
2157 pid_t pid;
2158 int status;
2159
2160 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
2161 (pid < 0 && errno == EINTR))
2162 ;
2163 errno = save_errno;
2164 }
2165