1 /* $OpenBSD: ssh.c,v 1.569 2021/09/20 04:02:13 dtucker Exp $ */
2 /*
3 * Author: Tatu Ylonen <[email protected]>
4 * Copyright (c) 1995 Tatu Ylonen <[email protected]>, 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 SSLeay by Niels Provos <[email protected]>
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 __RCSID("$FreeBSD$");
45
46 #include <sys/types.h>
47 #ifdef HAVE_SYS_STAT_H
48 # include <sys/stat.h>
49 #endif
50 #include <sys/resource.h>
51 #include <sys/ioctl.h>
52 #include <sys/socket.h>
53 #include <sys/wait.h>
54
55 #include <ctype.h>
56 #include <errno.h>
57 #include <fcntl.h>
58 #include <netdb.h>
59 #ifdef HAVE_PATHS_H
60 #include <paths.h>
61 #endif
62 #include <pwd.h>
63 #include <signal.h>
64 #include <stdarg.h>
65 #include <stddef.h>
66 #include <stdio.h>
67 #include <stdlib.h>
68 #include <string.h>
69 #include <stdarg.h>
70 #include <unistd.h>
71 #include <limits.h>
72 #include <locale.h>
73
74 #include <netinet/in.h>
75 #include <arpa/inet.h>
76
77 #ifdef WITH_OPENSSL
78 #include <openssl/evp.h>
79 #include <openssl/err.h>
80 #endif
81 #include "openbsd-compat/openssl-compat.h"
82 #include "openbsd-compat/sys-queue.h"
83
84 #include "xmalloc.h"
85 #include "ssh.h"
86 #include "ssh2.h"
87 #include "canohost.h"
88 #include "compat.h"
89 #include "cipher.h"
90 #include "packet.h"
91 #include "sshbuf.h"
92 #include "channels.h"
93 #include "sshkey.h"
94 #include "authfd.h"
95 #include "authfile.h"
96 #include "pathnames.h"
97 #include "dispatch.h"
98 #include "clientloop.h"
99 #include "log.h"
100 #include "misc.h"
101 #include "readconf.h"
102 #include "sshconnect.h"
103 #include "kex.h"
104 #include "mac.h"
105 #include "sshpty.h"
106 #include "match.h"
107 #include "msg.h"
108 #include "version.h"
109 #include "ssherr.h"
110 #include "myproposal.h"
111 #include "utf8.h"
112
113 #ifdef ENABLE_PKCS11
114 #include "ssh-pkcs11.h"
115 #endif
116
117 extern char *__progname;
118
119 /* Saves a copy of argv for setproctitle emulation */
120 #ifndef HAVE_SETPROCTITLE
121 static char **saved_av;
122 #endif
123
124 /* Flag indicating whether debug mode is on. May be set on the command line. */
125 int debug_flag = 0;
126
127 /* Flag indicating whether a tty should be requested */
128 int tty_flag = 0;
129
130 /*
131 * Flag indicating that the current process should be backgrounded and
132 * a new mux-client launched in the foreground for ControlPersist.
133 */
134 int need_controlpersist_detach = 0;
135
136 /* Copies of flags for ControlPersist foreground mux-client */
137 int ostdin_null_flag, osession_type, otty_flag, orequest_tty;
138
139 /*
140 * General data structure for command line options and options configurable
141 * in configuration files. See readconf.h.
142 */
143 Options options;
144
145 /* optional user configfile */
146 char *config = NULL;
147
148 /*
149 * Name of the host we are connecting to. This is the name given on the
150 * command line, or the Hostname specified for the user-supplied name in a
151 * configuration file.
152 */
153 char *host;
154
155 /*
156 * A config can specify a path to forward, overriding SSH_AUTH_SOCK. If this is
157 * not NULL, forward the socket at this path instead.
158 */
159 char *forward_agent_sock_path = NULL;
160
161 /* socket address the host resolves to */
162 struct sockaddr_storage hostaddr;
163
164 /* Private host keys. */
165 Sensitive sensitive_data;
166
167 /* command to be executed */
168 struct sshbuf *command;
169
170 /* # of replies received for global requests */
171 static int forward_confirms_pending = -1;
172
173 /* mux.c */
174 extern int muxserver_sock;
175 extern u_int muxclient_command;
176
177 /* Prints a help message to the user. This function never returns. */
178
179 static void
usage(void)180 usage(void)
181 {
182 fprintf(stderr,
183 "usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]\n"
184 " [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]\n"
185 " [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]\n"
186 " [-i identity_file] [-J [user@]host[:port]] [-L address]\n"
187 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
188 " [-Q query_option] [-R address] [-S ctl_path] [-W host:port]\n"
189 " [-w local_tun[:remote_tun]] destination [command [argument ...]]\n"
190 );
191 exit(255);
192 }
193
194 static int ssh_session2(struct ssh *, const struct ssh_conn_info *);
195 static void load_public_identity_files(const struct ssh_conn_info *);
196 static void main_sigchld_handler(int);
197
198 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */
199 static void
tilde_expand_paths(char ** paths,u_int num_paths)200 tilde_expand_paths(char **paths, u_int num_paths)
201 {
202 u_int i;
203 char *cp;
204
205 for (i = 0; i < num_paths; i++) {
206 cp = tilde_expand_filename(paths[i], getuid());
207 free(paths[i]);
208 paths[i] = cp;
209 }
210 }
211
212 /*
213 * Expands the set of percent_expand options used by the majority of keywords
214 * in the client that support percent expansion.
215 * Caller must free returned string.
216 */
217 static char *
default_client_percent_expand(const char * str,const struct ssh_conn_info * cinfo)218 default_client_percent_expand(const char *str,
219 const struct ssh_conn_info *cinfo)
220 {
221 return percent_expand(str,
222 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo),
223 (char *)NULL);
224 }
225
226 /*
227 * Expands the set of percent_expand options used by the majority of keywords
228 * AND perform environment variable substitution.
229 * Caller must free returned string.
230 */
231 static char *
default_client_percent_dollar_expand(const char * str,const struct ssh_conn_info * cinfo)232 default_client_percent_dollar_expand(const char *str,
233 const struct ssh_conn_info *cinfo)
234 {
235 char *ret;
236
237 ret = percent_dollar_expand(str,
238 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo),
239 (char *)NULL);
240 if (ret == NULL)
241 fatal("invalid environment variable expansion");
242 return ret;
243 }
244
245 /*
246 * Attempt to resolve a host name / port to a set of addresses and
247 * optionally return any CNAMEs encountered along the way.
248 * Returns NULL on failure.
249 * NB. this function must operate with a options having undefined members.
250 */
251 static struct addrinfo *
resolve_host(const char * name,int port,int logerr,char * cname,size_t clen)252 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen)
253 {
254 char strport[NI_MAXSERV];
255 struct addrinfo hints, *res;
256 int gaierr;
257 LogLevel loglevel = SYSLOG_LEVEL_DEBUG1;
258
259 if (port <= 0)
260 port = default_ssh_port();
261 if (cname != NULL)
262 *cname = '\0';
263 debug3_f("lookup %s:%d", name, port);
264
265 snprintf(strport, sizeof strport, "%d", port);
266 memset(&hints, 0, sizeof(hints));
267 hints.ai_family = options.address_family == -1 ?
268 AF_UNSPEC : options.address_family;
269 hints.ai_socktype = SOCK_STREAM;
270 if (cname != NULL)
271 hints.ai_flags = AI_CANONNAME;
272 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
273 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA))
274 loglevel = SYSLOG_LEVEL_ERROR;
275 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s",
276 __progname, name, ssh_gai_strerror(gaierr));
277 return NULL;
278 }
279 if (cname != NULL && res->ai_canonname != NULL) {
280 if (strlcpy(cname, res->ai_canonname, clen) >= clen) {
281 error_f("host \"%s\" cname \"%s\" too long (max %lu)",
282 name, res->ai_canonname, (u_long)clen);
283 if (clen > 0)
284 *cname = '\0';
285 }
286 }
287 return res;
288 }
289
290 /* Returns non-zero if name can only be an address and not a hostname */
291 static int
is_addr_fast(const char * name)292 is_addr_fast(const char *name)
293 {
294 return (strchr(name, '%') != NULL || strchr(name, ':') != NULL ||
295 strspn(name, "0123456789.") == strlen(name));
296 }
297
298 /* Returns non-zero if name represents a valid, single address */
299 static int
is_addr(const char * name)300 is_addr(const char *name)
301 {
302 char strport[NI_MAXSERV];
303 struct addrinfo hints, *res;
304
305 if (is_addr_fast(name))
306 return 1;
307
308 snprintf(strport, sizeof strport, "%u", default_ssh_port());
309 memset(&hints, 0, sizeof(hints));
310 hints.ai_family = options.address_family == -1 ?
311 AF_UNSPEC : options.address_family;
312 hints.ai_socktype = SOCK_STREAM;
313 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV;
314 if (getaddrinfo(name, strport, &hints, &res) != 0)
315 return 0;
316 if (res == NULL || res->ai_next != NULL) {
317 freeaddrinfo(res);
318 return 0;
319 }
320 freeaddrinfo(res);
321 return 1;
322 }
323
324 /*
325 * Attempt to resolve a numeric host address / port to a single address.
326 * Returns a canonical address string.
327 * Returns NULL on failure.
328 * NB. this function must operate with a options having undefined members.
329 */
330 static struct addrinfo *
resolve_addr(const char * name,int port,char * caddr,size_t clen)331 resolve_addr(const char *name, int port, char *caddr, size_t clen)
332 {
333 char addr[NI_MAXHOST], strport[NI_MAXSERV];
334 struct addrinfo hints, *res;
335 int gaierr;
336
337 if (port <= 0)
338 port = default_ssh_port();
339 snprintf(strport, sizeof strport, "%u", port);
340 memset(&hints, 0, sizeof(hints));
341 hints.ai_family = options.address_family == -1 ?
342 AF_UNSPEC : options.address_family;
343 hints.ai_socktype = SOCK_STREAM;
344 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV;
345 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
346 debug2_f("could not resolve name %.100s as address: %s",
347 name, ssh_gai_strerror(gaierr));
348 return NULL;
349 }
350 if (res == NULL) {
351 debug_f("getaddrinfo %.100s returned no addresses", name);
352 return NULL;
353 }
354 if (res->ai_next != NULL) {
355 debug_f("getaddrinfo %.100s returned multiple addresses", name);
356 goto fail;
357 }
358 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen,
359 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) {
360 debug_f("Could not format address for name %.100s: %s",
361 name, ssh_gai_strerror(gaierr));
362 goto fail;
363 }
364 if (strlcpy(caddr, addr, clen) >= clen) {
365 error_f("host \"%s\" addr \"%s\" too long (max %lu)",
366 name, addr, (u_long)clen);
367 if (clen > 0)
368 *caddr = '\0';
369 fail:
370 freeaddrinfo(res);
371 return NULL;
372 }
373 return res;
374 }
375
376 /*
377 * Check whether the cname is a permitted replacement for the hostname
378 * and perform the replacement if it is.
379 * NB. this function must operate with a options having undefined members.
380 */
381 static int
check_follow_cname(int direct,char ** namep,const char * cname)382 check_follow_cname(int direct, char **namep, const char *cname)
383 {
384 int i;
385 struct allowed_cname *rule;
386
387 if (*cname == '\0' || !config_has_permitted_cnames(&options) ||
388 strcmp(*namep, cname) == 0)
389 return 0;
390 if (options.canonicalize_hostname == SSH_CANONICALISE_NO)
391 return 0;
392 /*
393 * Don't attempt to canonicalize names that will be interpreted by
394 * a proxy or jump host unless the user specifically requests so.
395 */
396 if (!direct &&
397 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
398 return 0;
399 debug3_f("check \"%s\" CNAME \"%s\"", *namep, cname);
400 for (i = 0; i < options.num_permitted_cnames; i++) {
401 rule = options.permitted_cnames + i;
402 if (match_pattern_list(*namep, rule->source_list, 1) != 1 ||
403 match_pattern_list(cname, rule->target_list, 1) != 1)
404 continue;
405 verbose("Canonicalized DNS aliased hostname "
406 "\"%s\" => \"%s\"", *namep, cname);
407 free(*namep);
408 *namep = xstrdup(cname);
409 return 1;
410 }
411 return 0;
412 }
413
414 /*
415 * Attempt to resolve the supplied hostname after applying the user's
416 * canonicalization rules. Returns the address list for the host or NULL
417 * if no name was found after canonicalization.
418 * NB. this function must operate with a options having undefined members.
419 */
420 static struct addrinfo *
resolve_canonicalize(char ** hostp,int port)421 resolve_canonicalize(char **hostp, int port)
422 {
423 int i, direct, ndots;
424 char *cp, *fullhost, newname[NI_MAXHOST];
425 struct addrinfo *addrs;
426
427 /*
428 * Attempt to canonicalise addresses, regardless of
429 * whether hostname canonicalisation was requested
430 */
431 if ((addrs = resolve_addr(*hostp, port,
432 newname, sizeof(newname))) != NULL) {
433 debug2_f("hostname %.100s is address", *hostp);
434 if (strcasecmp(*hostp, newname) != 0) {
435 debug2_f("canonicalised address \"%s\" => \"%s\"",
436 *hostp, newname);
437 free(*hostp);
438 *hostp = xstrdup(newname);
439 }
440 return addrs;
441 }
442
443 /*
444 * If this looks like an address but didn't parse as one, it might
445 * be an address with an invalid interface scope. Skip further
446 * attempts at canonicalisation.
447 */
448 if (is_addr_fast(*hostp)) {
449 debug_f("hostname %.100s is an unrecognised address", *hostp);
450 return NULL;
451 }
452
453 if (options.canonicalize_hostname == SSH_CANONICALISE_NO)
454 return NULL;
455
456 /*
457 * Don't attempt to canonicalize names that will be interpreted by
458 * a proxy unless the user specifically requests so.
459 */
460 direct = option_clear_or_none(options.proxy_command) &&
461 options.jump_host == NULL;
462 if (!direct &&
463 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
464 return NULL;
465
466 /* If domain name is anchored, then resolve it now */
467 if ((*hostp)[strlen(*hostp) - 1] == '.') {
468 debug3_f("name is fully qualified");
469 fullhost = xstrdup(*hostp);
470 if ((addrs = resolve_host(fullhost, port, 0,
471 newname, sizeof(newname))) != NULL)
472 goto found;
473 free(fullhost);
474 goto notfound;
475 }
476
477 /* Don't apply canonicalization to sufficiently-qualified hostnames */
478 ndots = 0;
479 for (cp = *hostp; *cp != '\0'; cp++) {
480 if (*cp == '.')
481 ndots++;
482 }
483 if (ndots > options.canonicalize_max_dots) {
484 debug3_f("not canonicalizing hostname \"%s\" (max dots %d)",
485 *hostp, options.canonicalize_max_dots);
486 return NULL;
487 }
488 /* Attempt each supplied suffix */
489 for (i = 0; i < options.num_canonical_domains; i++) {
490 if (strcasecmp(options.canonical_domains[i], "none") == 0)
491 break;
492 xasprintf(&fullhost, "%s.%s.", *hostp,
493 options.canonical_domains[i]);
494 debug3_f("attempting \"%s\" => \"%s\"", *hostp, fullhost);
495 if ((addrs = resolve_host(fullhost, port, 0,
496 newname, sizeof(newname))) == NULL) {
497 free(fullhost);
498 continue;
499 }
500 found:
501 /* Remove trailing '.' */
502 fullhost[strlen(fullhost) - 1] = '\0';
503 /* Follow CNAME if requested */
504 if (!check_follow_cname(direct, &fullhost, newname)) {
505 debug("Canonicalized hostname \"%s\" => \"%s\"",
506 *hostp, fullhost);
507 }
508 free(*hostp);
509 *hostp = fullhost;
510 return addrs;
511 }
512 notfound:
513 if (!options.canonicalize_fallback_local)
514 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp);
515 debug2_f("host %s not found in any suffix", *hostp);
516 return NULL;
517 }
518
519 /*
520 * Check the result of hostkey loading, ignoring some errors and
521 * fatal()ing for others.
522 */
523 static void
check_load(int r,const char * path,const char * message)524 check_load(int r, const char *path, const char *message)
525 {
526 switch (r) {
527 case 0:
528 break;
529 case SSH_ERR_INTERNAL_ERROR:
530 case SSH_ERR_ALLOC_FAIL:
531 fatal_r(r, "load %s \"%s\"", message, path);
532 case SSH_ERR_SYSTEM_ERROR:
533 /* Ignore missing files */
534 if (errno == ENOENT)
535 break;
536 /* FALLTHROUGH */
537 default:
538 error_r(r, "load %s \"%s\"", message, path);
539 break;
540 }
541 }
542
543 /*
544 * Read per-user configuration file. Ignore the system wide config
545 * file if the user specifies a config file on the command line.
546 */
547 static void
process_config_files(const char * host_name,struct passwd * pw,int final_pass,int * want_final_pass)548 process_config_files(const char *host_name, struct passwd *pw, int final_pass,
549 int *want_final_pass)
550 {
551 char buf[PATH_MAX];
552 int r;
553
554 if (config != NULL) {
555 if (strcasecmp(config, "none") != 0 &&
556 !read_config_file(config, pw, host, host_name, &options,
557 SSHCONF_USERCONF | (final_pass ? SSHCONF_FINAL : 0),
558 want_final_pass))
559 fatal("Can't open user config file %.100s: "
560 "%.100s", config, strerror(errno));
561 } else {
562 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
563 _PATH_SSH_USER_CONFFILE);
564 if (r > 0 && (size_t)r < sizeof(buf))
565 (void)read_config_file(buf, pw, host, host_name,
566 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF |
567 (final_pass ? SSHCONF_FINAL : 0), want_final_pass);
568
569 /* Read systemwide configuration file after user config. */
570 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw,
571 host, host_name, &options,
572 final_pass ? SSHCONF_FINAL : 0, want_final_pass);
573 }
574 }
575
576 /* Rewrite the port number in an addrinfo list of addresses */
577 static void
set_addrinfo_port(struct addrinfo * addrs,int port)578 set_addrinfo_port(struct addrinfo *addrs, int port)
579 {
580 struct addrinfo *addr;
581
582 for (addr = addrs; addr != NULL; addr = addr->ai_next) {
583 switch (addr->ai_family) {
584 case AF_INET:
585 ((struct sockaddr_in *)addr->ai_addr)->
586 sin_port = htons(port);
587 break;
588 case AF_INET6:
589 ((struct sockaddr_in6 *)addr->ai_addr)->
590 sin6_port = htons(port);
591 break;
592 }
593 }
594 }
595
596 static void
ssh_conn_info_free(struct ssh_conn_info * cinfo)597 ssh_conn_info_free(struct ssh_conn_info *cinfo)
598 {
599 if (cinfo == NULL)
600 return;
601 free(cinfo->conn_hash_hex);
602 free(cinfo->shorthost);
603 free(cinfo->uidstr);
604 free(cinfo->keyalias);
605 free(cinfo->thishost);
606 free(cinfo->host_arg);
607 free(cinfo->portstr);
608 free(cinfo->remhost);
609 free(cinfo->remuser);
610 free(cinfo->homedir);
611 free(cinfo->locuser);
612 free(cinfo);
613 }
614
615 /*
616 * Main program for the ssh client.
617 */
618 int
main(int ac,char ** av)619 main(int ac, char **av)
620 {
621 struct ssh *ssh = NULL;
622 int i, r, opt, exit_status, use_syslog, direct, timeout_ms;
623 int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0;
624 char *p, *cp, *line, *argv0, *logfile, *host_arg;
625 char cname[NI_MAXHOST], thishost[NI_MAXHOST];
626 struct stat st;
627 struct passwd *pw;
628 extern int optind, optreset;
629 extern char *optarg;
630 struct Forward fwd;
631 struct addrinfo *addrs = NULL;
632 size_t n, len;
633 u_int j;
634 struct ssh_conn_info *cinfo = NULL;
635
636 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
637 sanitise_stdfd();
638
639 /*
640 * Discard other fds that are hanging around. These can cause problem
641 * with backgrounded ssh processes started by ControlPersist.
642 */
643 closefrom(STDERR_FILENO + 1);
644
645 __progname = ssh_get_progname(av[0]);
646
647 #ifndef HAVE_SETPROCTITLE
648 /* Prepare for later setproctitle emulation */
649 /* Save argv so it isn't clobbered by setproctitle() emulation */
650 saved_av = xcalloc(ac + 1, sizeof(*saved_av));
651 for (i = 0; i < ac; i++)
652 saved_av[i] = xstrdup(av[i]);
653 saved_av[i] = NULL;
654 compat_init_setproctitle(ac, av);
655 av = saved_av;
656 #endif
657
658 seed_rng();
659
660 /* Get user data. */
661 pw = getpwuid(getuid());
662 if (!pw) {
663 logit("No user exists for uid %lu", (u_long)getuid());
664 exit(255);
665 }
666 /* Take a copy of the returned structure. */
667 pw = pwcopy(pw);
668
669 /*
670 * Set our umask to something reasonable, as some files are created
671 * with the default umask. This will make them world-readable but
672 * writable only by the owner, which is ok for all files for which we
673 * don't set the modes explicitly.
674 */
675 umask(022);
676
677 msetlocale();
678
679 /*
680 * Initialize option structure to indicate that no values have been
681 * set.
682 */
683 initialize_options(&options);
684
685 /*
686 * Prepare main ssh transport/connection structures
687 */
688 if ((ssh = ssh_alloc_session_state()) == NULL)
689 fatal("Couldn't allocate session state");
690 channel_init_channels(ssh);
691
692 /* Parse command-line arguments. */
693 host = NULL;
694 use_syslog = 0;
695 logfile = NULL;
696 argv0 = av[0];
697
698 again:
699 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
700 "AB:CD:E:F:GI:J:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) {
701 switch (opt) {
702 case '1':
703 fatal("SSH protocol v.1 is no longer supported");
704 break;
705 case '2':
706 /* Ignored */
707 break;
708 case '4':
709 options.address_family = AF_INET;
710 break;
711 case '6':
712 options.address_family = AF_INET6;
713 break;
714 case 'n':
715 options.stdin_null = 1;
716 break;
717 case 'f':
718 options.fork_after_authentication = 1;
719 options.stdin_null = 1;
720 break;
721 case 'x':
722 options.forward_x11 = 0;
723 break;
724 case 'X':
725 options.forward_x11 = 1;
726 break;
727 case 'y':
728 use_syslog = 1;
729 break;
730 case 'E':
731 logfile = optarg;
732 break;
733 case 'G':
734 config_test = 1;
735 break;
736 case 'Y':
737 options.forward_x11 = 1;
738 options.forward_x11_trusted = 1;
739 break;
740 case 'g':
741 options.fwd_opts.gateway_ports = 1;
742 break;
743 case 'O':
744 if (options.stdio_forward_host != NULL)
745 fatal("Cannot specify multiplexing "
746 "command with -W");
747 else if (muxclient_command != 0)
748 fatal("Multiplexing command already specified");
749 if (strcmp(optarg, "check") == 0)
750 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
751 else if (strcmp(optarg, "forward") == 0)
752 muxclient_command = SSHMUX_COMMAND_FORWARD;
753 else if (strcmp(optarg, "exit") == 0)
754 muxclient_command = SSHMUX_COMMAND_TERMINATE;
755 else if (strcmp(optarg, "stop") == 0)
756 muxclient_command = SSHMUX_COMMAND_STOP;
757 else if (strcmp(optarg, "cancel") == 0)
758 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD;
759 else if (strcmp(optarg, "proxy") == 0)
760 muxclient_command = SSHMUX_COMMAND_PROXY;
761 else
762 fatal("Invalid multiplex command.");
763 break;
764 case 'P': /* deprecated */
765 break;
766 case 'Q':
767 cp = NULL;
768 if (strcmp(optarg, "cipher") == 0 ||
769 strcasecmp(optarg, "Ciphers") == 0)
770 cp = cipher_alg_list('\n', 0);
771 else if (strcmp(optarg, "cipher-auth") == 0)
772 cp = cipher_alg_list('\n', 1);
773 else if (strcmp(optarg, "mac") == 0 ||
774 strcasecmp(optarg, "MACs") == 0)
775 cp = mac_alg_list('\n');
776 else if (strcmp(optarg, "kex") == 0 ||
777 strcasecmp(optarg, "KexAlgorithms") == 0)
778 cp = kex_alg_list('\n');
779 else if (strcmp(optarg, "key") == 0)
780 cp = sshkey_alg_list(0, 0, 0, '\n');
781 else if (strcmp(optarg, "key-cert") == 0)
782 cp = sshkey_alg_list(1, 0, 0, '\n');
783 else if (strcmp(optarg, "key-plain") == 0)
784 cp = sshkey_alg_list(0, 1, 0, '\n');
785 else if (strcmp(optarg, "key-sig") == 0 ||
786 strcasecmp(optarg, "PubkeyAcceptedKeyTypes") == 0 || /* deprecated name */
787 strcasecmp(optarg, "PubkeyAcceptedAlgorithms") == 0 ||
788 strcasecmp(optarg, "HostKeyAlgorithms") == 0 ||
789 strcasecmp(optarg, "HostbasedKeyTypes") == 0 || /* deprecated name */
790 strcasecmp(optarg, "HostbasedAcceptedKeyTypes") == 0 || /* deprecated name */
791 strcasecmp(optarg, "HostbasedAcceptedAlgorithms") == 0)
792 cp = sshkey_alg_list(0, 0, 1, '\n');
793 else if (strcmp(optarg, "sig") == 0)
794 cp = sshkey_alg_list(0, 1, 1, '\n');
795 else if (strcmp(optarg, "protocol-version") == 0)
796 cp = xstrdup("2");
797 else if (strcmp(optarg, "compression") == 0) {
798 cp = xstrdup(compression_alg_list(0));
799 len = strlen(cp);
800 for (n = 0; n < len; n++)
801 if (cp[n] == ',')
802 cp[n] = '\n';
803 } else if (strcmp(optarg, "help") == 0) {
804 cp = xstrdup(
805 "cipher\ncipher-auth\ncompression\nkex\n"
806 "key\nkey-cert\nkey-plain\nkey-sig\nmac\n"
807 "protocol-version\nsig");
808 }
809 if (cp == NULL)
810 fatal("Unsupported query \"%s\"", optarg);
811 printf("%s\n", cp);
812 free(cp);
813 exit(0);
814 break;
815 case 'a':
816 options.forward_agent = 0;
817 break;
818 case 'A':
819 options.forward_agent = 1;
820 break;
821 case 'k':
822 options.gss_deleg_creds = 0;
823 break;
824 case 'K':
825 options.gss_authentication = 1;
826 options.gss_deleg_creds = 1;
827 break;
828 case 'i':
829 p = tilde_expand_filename(optarg, getuid());
830 if (stat(p, &st) == -1)
831 fprintf(stderr, "Warning: Identity file %s "
832 "not accessible: %s.\n", p,
833 strerror(errno));
834 else
835 add_identity_file(&options, NULL, p, 1);
836 free(p);
837 break;
838 case 'I':
839 #ifdef ENABLE_PKCS11
840 free(options.pkcs11_provider);
841 options.pkcs11_provider = xstrdup(optarg);
842 #else
843 fprintf(stderr, "no support for PKCS#11.\n");
844 #endif
845 break;
846 case 'J':
847 if (options.jump_host != NULL) {
848 fatal("Only a single -J option is permitted "
849 "(use commas to separate multiple "
850 "jump hops)");
851 }
852 if (options.proxy_command != NULL)
853 fatal("Cannot specify -J with ProxyCommand");
854 if (parse_jump(optarg, &options, 1) == -1)
855 fatal("Invalid -J argument");
856 options.proxy_command = xstrdup("none");
857 break;
858 case 't':
859 if (options.request_tty == REQUEST_TTY_YES)
860 options.request_tty = REQUEST_TTY_FORCE;
861 else
862 options.request_tty = REQUEST_TTY_YES;
863 break;
864 case 'v':
865 if (debug_flag == 0) {
866 debug_flag = 1;
867 options.log_level = SYSLOG_LEVEL_DEBUG1;
868 } else {
869 if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
870 debug_flag++;
871 options.log_level++;
872 }
873 }
874 break;
875 case 'V':
876 if (options.version_addendum &&
877 *options.version_addendum != '\0')
878 fprintf(stderr, "%s %s, %s\n", SSH_RELEASE,
879 options.version_addendum,
880 OPENSSL_VERSION_STRING);
881 else
882 fprintf(stderr, "%s, %s\n", SSH_RELEASE,
883 OPENSSL_VERSION_STRING);
884 if (opt == 'V')
885 exit(0);
886 break;
887 case 'w':
888 if (options.tun_open == -1)
889 options.tun_open = SSH_TUNMODE_DEFAULT;
890 options.tun_local = a2tun(optarg, &options.tun_remote);
891 if (options.tun_local == SSH_TUNID_ERR) {
892 fprintf(stderr,
893 "Bad tun device '%s'\n", optarg);
894 exit(255);
895 }
896 break;
897 case 'W':
898 if (options.stdio_forward_host != NULL)
899 fatal("stdio forward already specified");
900 if (muxclient_command != 0)
901 fatal("Cannot specify stdio forward with -O");
902 if (parse_forward(&fwd, optarg, 1, 0)) {
903 options.stdio_forward_host = fwd.listen_host;
904 options.stdio_forward_port = fwd.listen_port;
905 free(fwd.connect_host);
906 } else {
907 fprintf(stderr,
908 "Bad stdio forwarding specification '%s'\n",
909 optarg);
910 exit(255);
911 }
912 options.request_tty = REQUEST_TTY_NO;
913 options.session_type = SESSION_TYPE_NONE;
914 break;
915 case 'q':
916 options.log_level = SYSLOG_LEVEL_QUIET;
917 break;
918 case 'e':
919 if (optarg[0] == '^' && optarg[2] == 0 &&
920 (u_char) optarg[1] >= 64 &&
921 (u_char) optarg[1] < 128)
922 options.escape_char = (u_char) optarg[1] & 31;
923 else if (strlen(optarg) == 1)
924 options.escape_char = (u_char) optarg[0];
925 else if (strcmp(optarg, "none") == 0)
926 options.escape_char = SSH_ESCAPECHAR_NONE;
927 else {
928 fprintf(stderr, "Bad escape character '%s'.\n",
929 optarg);
930 exit(255);
931 }
932 break;
933 case 'c':
934 if (!ciphers_valid(*optarg == '+' || *optarg == '^' ?
935 optarg + 1 : optarg)) {
936 fprintf(stderr, "Unknown cipher type '%s'\n",
937 optarg);
938 exit(255);
939 }
940 free(options.ciphers);
941 options.ciphers = xstrdup(optarg);
942 break;
943 case 'm':
944 if (mac_valid(optarg)) {
945 free(options.macs);
946 options.macs = xstrdup(optarg);
947 } else {
948 fprintf(stderr, "Unknown mac type '%s'\n",
949 optarg);
950 exit(255);
951 }
952 break;
953 case 'M':
954 if (options.control_master == SSHCTL_MASTER_YES)
955 options.control_master = SSHCTL_MASTER_ASK;
956 else
957 options.control_master = SSHCTL_MASTER_YES;
958 break;
959 case 'p':
960 if (options.port == -1) {
961 options.port = a2port(optarg);
962 if (options.port <= 0) {
963 fprintf(stderr, "Bad port '%s'\n",
964 optarg);
965 exit(255);
966 }
967 }
968 break;
969 case 'l':
970 if (options.user == NULL)
971 options.user = optarg;
972 break;
973
974 case 'L':
975 if (parse_forward(&fwd, optarg, 0, 0))
976 add_local_forward(&options, &fwd);
977 else {
978 fprintf(stderr,
979 "Bad local forwarding specification '%s'\n",
980 optarg);
981 exit(255);
982 }
983 break;
984
985 case 'R':
986 if (parse_forward(&fwd, optarg, 0, 1) ||
987 parse_forward(&fwd, optarg, 1, 1)) {
988 add_remote_forward(&options, &fwd);
989 } else {
990 fprintf(stderr,
991 "Bad remote forwarding specification "
992 "'%s'\n", optarg);
993 exit(255);
994 }
995 break;
996
997 case 'D':
998 if (parse_forward(&fwd, optarg, 1, 0)) {
999 add_local_forward(&options, &fwd);
1000 } else {
1001 fprintf(stderr,
1002 "Bad dynamic forwarding specification "
1003 "'%s'\n", optarg);
1004 exit(255);
1005 }
1006 break;
1007
1008 case 'C':
1009 #ifdef WITH_ZLIB
1010 options.compression = 1;
1011 #else
1012 error("Compression not supported, disabling.");
1013 #endif
1014 break;
1015 case 'N':
1016 if (options.session_type != -1 &&
1017 options.session_type != SESSION_TYPE_NONE)
1018 fatal("Cannot specify -N with -s/SessionType");
1019 options.session_type = SESSION_TYPE_NONE;
1020 options.request_tty = REQUEST_TTY_NO;
1021 break;
1022 case 'T':
1023 options.request_tty = REQUEST_TTY_NO;
1024 break;
1025 case 'o':
1026 line = xstrdup(optarg);
1027 if (process_config_line(&options, pw,
1028 host ? host : "", host ? host : "", line,
1029 "command-line", 0, NULL, SSHCONF_USERCONF) != 0)
1030 exit(255);
1031 free(line);
1032 break;
1033 case 's':
1034 if (options.session_type != -1 &&
1035 options.session_type != SESSION_TYPE_SUBSYSTEM)
1036 fatal("Cannot specify -s with -N/SessionType");
1037 options.session_type = SESSION_TYPE_SUBSYSTEM;
1038 break;
1039 case 'S':
1040 free(options.control_path);
1041 options.control_path = xstrdup(optarg);
1042 break;
1043 case 'b':
1044 options.bind_address = optarg;
1045 break;
1046 case 'B':
1047 options.bind_interface = optarg;
1048 break;
1049 case 'F':
1050 config = optarg;
1051 break;
1052 default:
1053 usage();
1054 }
1055 }
1056
1057 if (optind > 1 && strcmp(av[optind - 1], "--") == 0)
1058 opt_terminated = 1;
1059
1060 ac -= optind;
1061 av += optind;
1062
1063 if (ac > 0 && !host) {
1064 int tport;
1065 char *tuser;
1066 switch (parse_ssh_uri(*av, &tuser, &host, &tport)) {
1067 case -1:
1068 usage();
1069 break;
1070 case 0:
1071 if (options.user == NULL) {
1072 options.user = tuser;
1073 tuser = NULL;
1074 }
1075 free(tuser);
1076 if (options.port == -1 && tport != -1)
1077 options.port = tport;
1078 break;
1079 default:
1080 p = xstrdup(*av);
1081 cp = strrchr(p, '@');
1082 if (cp != NULL) {
1083 if (cp == p)
1084 usage();
1085 if (options.user == NULL) {
1086 options.user = p;
1087 p = NULL;
1088 }
1089 *cp++ = '\0';
1090 host = xstrdup(cp);
1091 free(p);
1092 } else
1093 host = p;
1094 break;
1095 }
1096 if (ac > 1 && !opt_terminated) {
1097 optind = optreset = 1;
1098 goto again;
1099 }
1100 ac--, av++;
1101 }
1102
1103 /* Check that we got a host name. */
1104 if (!host)
1105 usage();
1106
1107 host_arg = xstrdup(host);
1108
1109 /* Initialize the command to execute on remote host. */
1110 if ((command = sshbuf_new()) == NULL)
1111 fatal("sshbuf_new failed");
1112
1113 /*
1114 * Save the command to execute on the remote host in a buffer. There
1115 * is no limit on the length of the command, except by the maximum
1116 * packet size. Also sets the tty flag if there is no command.
1117 */
1118 if (!ac) {
1119 /* No command specified - execute shell on a tty. */
1120 if (options.session_type == SESSION_TYPE_SUBSYSTEM) {
1121 fprintf(stderr,
1122 "You must specify a subsystem to invoke.\n");
1123 usage();
1124 }
1125 } else {
1126 /* A command has been specified. Store it into the buffer. */
1127 for (i = 0; i < ac; i++) {
1128 if ((r = sshbuf_putf(command, "%s%s",
1129 i ? " " : "", av[i])) != 0)
1130 fatal_fr(r, "buffer error");
1131 }
1132 }
1133
1134 /*
1135 * Initialize "log" output. Since we are the client all output
1136 * goes to stderr unless otherwise specified by -y or -E.
1137 */
1138 if (use_syslog && logfile != NULL)
1139 fatal("Can't specify both -y and -E");
1140 if (logfile != NULL)
1141 log_redirect_stderr_to(logfile);
1142 log_init(argv0,
1143 options.log_level == SYSLOG_LEVEL_NOT_SET ?
1144 SYSLOG_LEVEL_INFO : options.log_level,
1145 options.log_facility == SYSLOG_FACILITY_NOT_SET ?
1146 SYSLOG_FACILITY_USER : options.log_facility,
1147 !use_syslog);
1148
1149 if (debug_flag)
1150 /* version_addendum is always NULL at this point */
1151 logit("%s, %s", SSH_RELEASE, OPENSSL_VERSION_STRING);
1152
1153 /* Parse the configuration files */
1154 process_config_files(host_arg, pw, 0, &want_final_pass);
1155 if (want_final_pass)
1156 debug("configuration requests final Match pass");
1157
1158 /* Hostname canonicalisation needs a few options filled. */
1159 fill_default_options_for_canonicalization(&options);
1160
1161 /* If the user has replaced the hostname then take it into use now */
1162 if (options.hostname != NULL) {
1163 /* NB. Please keep in sync with readconf.c:match_cfg_line() */
1164 cp = percent_expand(options.hostname,
1165 "h", host, (char *)NULL);
1166 free(host);
1167 host = cp;
1168 free(options.hostname);
1169 options.hostname = xstrdup(host);
1170 }
1171
1172 /* Don't lowercase addresses, they will be explicitly canonicalised */
1173 if ((was_addr = is_addr(host)) == 0)
1174 lowercase(host);
1175
1176 /*
1177 * Try to canonicalize if requested by configuration or the
1178 * hostname is an address.
1179 */
1180 if (options.canonicalize_hostname != SSH_CANONICALISE_NO || was_addr)
1181 addrs = resolve_canonicalize(&host, options.port);
1182
1183 /*
1184 * If CanonicalizePermittedCNAMEs have been specified but
1185 * other canonicalization did not happen (by not being requested
1186 * or by failing with fallback) then the hostname may still be changed
1187 * as a result of CNAME following.
1188 *
1189 * Try to resolve the bare hostname name using the system resolver's
1190 * usual search rules and then apply the CNAME follow rules.
1191 *
1192 * Skip the lookup if a ProxyCommand is being used unless the user
1193 * has specifically requested canonicalisation for this case via
1194 * CanonicalizeHostname=always
1195 */
1196 direct = option_clear_or_none(options.proxy_command) &&
1197 options.jump_host == NULL;
1198 if (addrs == NULL && config_has_permitted_cnames(&options) && (direct ||
1199 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) {
1200 if ((addrs = resolve_host(host, options.port,
1201 direct, cname, sizeof(cname))) == NULL) {
1202 /* Don't fatal proxied host names not in the DNS */
1203 if (direct)
1204 cleanup_exit(255); /* logged in resolve_host */
1205 } else
1206 check_follow_cname(direct, &host, cname);
1207 }
1208
1209 /*
1210 * If canonicalisation is enabled then re-parse the configuration
1211 * files as new stanzas may match.
1212 */
1213 if (options.canonicalize_hostname != 0 && !want_final_pass) {
1214 debug("hostname canonicalisation enabled, "
1215 "will re-parse configuration");
1216 want_final_pass = 1;
1217 }
1218
1219 if (want_final_pass) {
1220 debug("re-parsing configuration");
1221 free(options.hostname);
1222 options.hostname = xstrdup(host);
1223 process_config_files(host_arg, pw, 1, NULL);
1224 /*
1225 * Address resolution happens early with canonicalisation
1226 * enabled and the port number may have changed since, so
1227 * reset it in address list
1228 */
1229 if (addrs != NULL && options.port > 0)
1230 set_addrinfo_port(addrs, options.port);
1231 }
1232
1233 /* Fill configuration defaults. */
1234 if (fill_default_options(&options) != 0)
1235 cleanup_exit(255);
1236
1237 if (options.user == NULL)
1238 options.user = xstrdup(pw->pw_name);
1239
1240 /*
1241 * If ProxyJump option specified, then construct a ProxyCommand now.
1242 */
1243 if (options.jump_host != NULL) {
1244 char port_s[8];
1245 const char *jumpuser = options.jump_user, *sshbin = argv0;
1246 int port = options.port, jumpport = options.jump_port;
1247
1248 if (port <= 0)
1249 port = default_ssh_port();
1250 if (jumpport <= 0)
1251 jumpport = default_ssh_port();
1252 if (jumpuser == NULL)
1253 jumpuser = options.user;
1254 if (strcmp(options.jump_host, host) == 0 && port == jumpport &&
1255 strcmp(options.user, jumpuser) == 0)
1256 fatal("jumphost loop via %s", options.jump_host);
1257
1258 /*
1259 * Try to use SSH indicated by argv[0], but fall back to
1260 * "ssh" if it appears unavailable.
1261 */
1262 if (strchr(argv0, '/') != NULL && access(argv0, X_OK) != 0)
1263 sshbin = "ssh";
1264
1265 /* Consistency check */
1266 if (options.proxy_command != NULL)
1267 fatal("inconsistent options: ProxyCommand+ProxyJump");
1268 /* Never use FD passing for ProxyJump */
1269 options.proxy_use_fdpass = 0;
1270 snprintf(port_s, sizeof(port_s), "%d", options.jump_port);
1271 xasprintf(&options.proxy_command,
1272 "%s%s%s%s%s%s%s%s%s%s%.*s -W '[%%h]:%%p' %s",
1273 sshbin,
1274 /* Optional "-l user" argument if jump_user set */
1275 options.jump_user == NULL ? "" : " -l ",
1276 options.jump_user == NULL ? "" : options.jump_user,
1277 /* Optional "-p port" argument if jump_port set */
1278 options.jump_port <= 0 ? "" : " -p ",
1279 options.jump_port <= 0 ? "" : port_s,
1280 /* Optional additional jump hosts ",..." */
1281 options.jump_extra == NULL ? "" : " -J ",
1282 options.jump_extra == NULL ? "" : options.jump_extra,
1283 /* Optional "-F" argumment if -F specified */
1284 config == NULL ? "" : " -F ",
1285 config == NULL ? "" : config,
1286 /* Optional "-v" arguments if -v set */
1287 debug_flag ? " -" : "",
1288 debug_flag, "vvv",
1289 /* Mandatory hostname */
1290 options.jump_host);
1291 debug("Setting implicit ProxyCommand from ProxyJump: %s",
1292 options.proxy_command);
1293 }
1294
1295 if (options.port == 0)
1296 options.port = default_ssh_port();
1297 channel_set_af(ssh, options.address_family);
1298
1299 /* Tidy and check options */
1300 if (options.host_key_alias != NULL)
1301 lowercase(options.host_key_alias);
1302 if (options.proxy_command != NULL &&
1303 strcmp(options.proxy_command, "-") == 0 &&
1304 options.proxy_use_fdpass)
1305 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible");
1306 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) {
1307 if (options.control_persist && options.control_path != NULL) {
1308 debug("UpdateHostKeys=ask is incompatible with "
1309 "ControlPersist; disabling");
1310 options.update_hostkeys = 0;
1311 } else if (sshbuf_len(command) != 0 ||
1312 options.remote_command != NULL ||
1313 options.request_tty == REQUEST_TTY_NO) {
1314 debug("UpdateHostKeys=ask is incompatible with "
1315 "remote command execution; disabling");
1316 options.update_hostkeys = 0;
1317 } else if (options.log_level < SYSLOG_LEVEL_INFO) {
1318 /* no point logging anything; user won't see it */
1319 options.update_hostkeys = 0;
1320 }
1321 }
1322 if (options.connection_attempts <= 0)
1323 fatal("Invalid number of ConnectionAttempts");
1324
1325 if (sshbuf_len(command) != 0 && options.remote_command != NULL)
1326 fatal("Cannot execute command-line and remote command.");
1327
1328 /* Cannot fork to background if no command. */
1329 if (options.fork_after_authentication && sshbuf_len(command) == 0 &&
1330 options.remote_command == NULL &&
1331 options.session_type != SESSION_TYPE_NONE)
1332 fatal("Cannot fork into background without a command "
1333 "to execute.");
1334
1335 /* reinit */
1336 log_init(argv0, options.log_level, options.log_facility, !use_syslog);
1337 for (j = 0; j < options.num_log_verbose; j++) {
1338 if (strcasecmp(options.log_verbose[j], "none") == 0)
1339 break;
1340 log_verbose_add(options.log_verbose[j]);
1341 }
1342
1343 if (options.request_tty == REQUEST_TTY_YES ||
1344 options.request_tty == REQUEST_TTY_FORCE)
1345 tty_flag = 1;
1346
1347 /* Allocate a tty by default if no command specified. */
1348 if (sshbuf_len(command) == 0 && options.remote_command == NULL)
1349 tty_flag = options.request_tty != REQUEST_TTY_NO;
1350
1351 /* Force no tty */
1352 if (options.request_tty == REQUEST_TTY_NO ||
1353 (muxclient_command && muxclient_command != SSHMUX_COMMAND_PROXY))
1354 tty_flag = 0;
1355 /* Do not allocate a tty if stdin is not a tty. */
1356 if ((!isatty(fileno(stdin)) || options.stdin_null) &&
1357 options.request_tty != REQUEST_TTY_FORCE) {
1358 if (tty_flag)
1359 logit("Pseudo-terminal will not be allocated because "
1360 "stdin is not a terminal.");
1361 tty_flag = 0;
1362 }
1363
1364 /* Set up strings used to percent_expand() arguments */
1365 cinfo = xcalloc(1, sizeof(*cinfo));
1366 if (gethostname(thishost, sizeof(thishost)) == -1)
1367 fatal("gethostname: %s", strerror(errno));
1368 cinfo->thishost = xstrdup(thishost);
1369 thishost[strcspn(thishost, ".")] = '\0';
1370 cinfo->shorthost = xstrdup(thishost);
1371 xasprintf(&cinfo->portstr, "%d", options.port);
1372 xasprintf(&cinfo->uidstr, "%llu",
1373 (unsigned long long)pw->pw_uid);
1374 cinfo->keyalias = xstrdup(options.host_key_alias ?
1375 options.host_key_alias : host_arg);
1376 cinfo->conn_hash_hex = ssh_connection_hash(cinfo->thishost, host,
1377 cinfo->portstr, options.user);
1378 cinfo->host_arg = xstrdup(host_arg);
1379 cinfo->remhost = xstrdup(host);
1380 cinfo->remuser = xstrdup(options.user);
1381 cinfo->homedir = xstrdup(pw->pw_dir);
1382 cinfo->locuser = xstrdup(pw->pw_name);
1383
1384 /* Find canonic host name. */
1385 if (strchr(host, '.') == 0) {
1386 struct addrinfo hints;
1387 struct addrinfo *ai = NULL;
1388 int errgai;
1389 memset(&hints, 0, sizeof(hints));
1390 hints.ai_family = options.address_family;
1391 hints.ai_flags = AI_CANONNAME;
1392 hints.ai_socktype = SOCK_STREAM;
1393 errgai = getaddrinfo(host, NULL, &hints, &ai);
1394 if (errgai == 0) {
1395 if (ai->ai_canonname != NULL)
1396 host = xstrdup(ai->ai_canonname);
1397 freeaddrinfo(ai);
1398 }
1399 }
1400
1401 /*
1402 * Expand tokens in arguments. NB. LocalCommand is expanded later,
1403 * after port-forwarding is set up, so it may pick up any local
1404 * tunnel interface name allocated.
1405 */
1406 if (options.remote_command != NULL) {
1407 debug3("expanding RemoteCommand: %s", options.remote_command);
1408 cp = options.remote_command;
1409 options.remote_command = default_client_percent_expand(cp,
1410 cinfo);
1411 debug3("expanded RemoteCommand: %s", options.remote_command);
1412 free(cp);
1413 if ((r = sshbuf_put(command, options.remote_command,
1414 strlen(options.remote_command))) != 0)
1415 fatal_fr(r, "buffer error");
1416 }
1417
1418 if (options.control_path != NULL) {
1419 cp = tilde_expand_filename(options.control_path, getuid());
1420 free(options.control_path);
1421 options.control_path = default_client_percent_dollar_expand(cp,
1422 cinfo);
1423 free(cp);
1424 }
1425
1426 if (options.identity_agent != NULL) {
1427 p = tilde_expand_filename(options.identity_agent, getuid());
1428 cp = default_client_percent_dollar_expand(p, cinfo);
1429 free(p);
1430 free(options.identity_agent);
1431 options.identity_agent = cp;
1432 }
1433
1434 if (options.forward_agent_sock_path != NULL) {
1435 p = tilde_expand_filename(options.forward_agent_sock_path,
1436 getuid());
1437 cp = default_client_percent_dollar_expand(p, cinfo);
1438 free(p);
1439 free(options.forward_agent_sock_path);
1440 options.forward_agent_sock_path = cp;
1441 if (stat(options.forward_agent_sock_path, &st) != 0) {
1442 error("Cannot forward agent socket path \"%s\": %s",
1443 options.forward_agent_sock_path, strerror(errno));
1444 if (options.exit_on_forward_failure)
1445 cleanup_exit(255);
1446 }
1447 }
1448
1449 if (options.num_system_hostfiles > 0 &&
1450 strcasecmp(options.system_hostfiles[0], "none") == 0) {
1451 if (options.num_system_hostfiles > 1)
1452 fatal("Invalid GlobalKnownHostsFiles: \"none\" "
1453 "appears with other entries");
1454 free(options.system_hostfiles[0]);
1455 options.system_hostfiles[0] = NULL;
1456 options.num_system_hostfiles = 0;
1457 }
1458
1459 if (options.num_user_hostfiles > 0 &&
1460 strcasecmp(options.user_hostfiles[0], "none") == 0) {
1461 if (options.num_user_hostfiles > 1)
1462 fatal("Invalid UserKnownHostsFiles: \"none\" "
1463 "appears with other entries");
1464 free(options.user_hostfiles[0]);
1465 options.user_hostfiles[0] = NULL;
1466 options.num_user_hostfiles = 0;
1467 }
1468 for (j = 0; j < options.num_user_hostfiles; j++) {
1469 if (options.user_hostfiles[j] == NULL)
1470 continue;
1471 cp = tilde_expand_filename(options.user_hostfiles[j], getuid());
1472 p = default_client_percent_dollar_expand(cp, cinfo);
1473 if (strcmp(options.user_hostfiles[j], p) != 0)
1474 debug3("expanded UserKnownHostsFile '%s' -> "
1475 "'%s'", options.user_hostfiles[j], p);
1476 free(options.user_hostfiles[j]);
1477 free(cp);
1478 options.user_hostfiles[j] = p;
1479 }
1480
1481 for (i = 0; i < options.num_local_forwards; i++) {
1482 if (options.local_forwards[i].listen_path != NULL) {
1483 cp = options.local_forwards[i].listen_path;
1484 p = options.local_forwards[i].listen_path =
1485 default_client_percent_expand(cp, cinfo);
1486 if (strcmp(cp, p) != 0)
1487 debug3("expanded LocalForward listen path "
1488 "'%s' -> '%s'", cp, p);
1489 free(cp);
1490 }
1491 if (options.local_forwards[i].connect_path != NULL) {
1492 cp = options.local_forwards[i].connect_path;
1493 p = options.local_forwards[i].connect_path =
1494 default_client_percent_expand(cp, cinfo);
1495 if (strcmp(cp, p) != 0)
1496 debug3("expanded LocalForward connect path "
1497 "'%s' -> '%s'", cp, p);
1498 free(cp);
1499 }
1500 }
1501
1502 for (i = 0; i < options.num_remote_forwards; i++) {
1503 if (options.remote_forwards[i].listen_path != NULL) {
1504 cp = options.remote_forwards[i].listen_path;
1505 p = options.remote_forwards[i].listen_path =
1506 default_client_percent_expand(cp, cinfo);
1507 if (strcmp(cp, p) != 0)
1508 debug3("expanded RemoteForward listen path "
1509 "'%s' -> '%s'", cp, p);
1510 free(cp);
1511 }
1512 if (options.remote_forwards[i].connect_path != NULL) {
1513 cp = options.remote_forwards[i].connect_path;
1514 p = options.remote_forwards[i].connect_path =
1515 default_client_percent_expand(cp, cinfo);
1516 if (strcmp(cp, p) != 0)
1517 debug3("expanded RemoteForward connect path "
1518 "'%s' -> '%s'", cp, p);
1519 free(cp);
1520 }
1521 }
1522
1523 if (config_test) {
1524 dump_client_config(&options, host);
1525 exit(0);
1526 }
1527
1528 /* Expand SecurityKeyProvider if it refers to an environment variable */
1529 if (options.sk_provider != NULL && *options.sk_provider == '$' &&
1530 strlen(options.sk_provider) > 1) {
1531 if ((cp = getenv(options.sk_provider + 1)) == NULL) {
1532 debug("Authenticator provider %s did not resolve; "
1533 "disabling", options.sk_provider);
1534 free(options.sk_provider);
1535 options.sk_provider = NULL;
1536 } else {
1537 debug2("resolved SecurityKeyProvider %s => %s",
1538 options.sk_provider, cp);
1539 free(options.sk_provider);
1540 options.sk_provider = xstrdup(cp);
1541 }
1542 }
1543
1544 if (muxclient_command != 0 && options.control_path == NULL)
1545 fatal("No ControlPath specified for \"-O\" command");
1546 if (options.control_path != NULL) {
1547 int sock;
1548 if ((sock = muxclient(options.control_path)) >= 0) {
1549 ssh_packet_set_connection(ssh, sock, sock);
1550 ssh_packet_set_mux(ssh);
1551 goto skip_connect;
1552 }
1553 }
1554
1555 /*
1556 * If hostname canonicalisation was not enabled, then we may not
1557 * have yet resolved the hostname. Do so now.
1558 */
1559 if (addrs == NULL && options.proxy_command == NULL) {
1560 debug2("resolving \"%s\" port %d", host, options.port);
1561 if ((addrs = resolve_host(host, options.port, 1,
1562 cname, sizeof(cname))) == NULL)
1563 cleanup_exit(255); /* resolve_host logs the error */
1564 }
1565
1566 if (options.connection_timeout >= INT_MAX/1000)
1567 timeout_ms = INT_MAX;
1568 else
1569 timeout_ms = options.connection_timeout * 1000;
1570
1571 /* Open a connection to the remote host. */
1572 if (ssh_connect(ssh, host, host_arg, addrs, &hostaddr, options.port,
1573 options.connection_attempts,
1574 &timeout_ms, options.tcp_keep_alive) != 0)
1575 exit(255);
1576
1577 if (addrs != NULL)
1578 freeaddrinfo(addrs);
1579
1580 ssh_packet_set_timeout(ssh, options.server_alive_interval,
1581 options.server_alive_count_max);
1582
1583 if (timeout_ms > 0)
1584 debug3("timeout: %d ms remain after connect", timeout_ms);
1585
1586 /*
1587 * If we successfully made the connection and we have hostbased auth
1588 * enabled, load the public keys so we can later use the ssh-keysign
1589 * helper to sign challenges.
1590 */
1591 sensitive_data.nkeys = 0;
1592 sensitive_data.keys = NULL;
1593 if (options.hostbased_authentication) {
1594 sensitive_data.nkeys = 10;
1595 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
1596 sizeof(struct sshkey));
1597
1598 /* XXX check errors? */
1599 #define L_PUBKEY(p,o) do { \
1600 if ((o) >= sensitive_data.nkeys) \
1601 fatal_f("pubkey out of array bounds"); \
1602 check_load(sshkey_load_public(p, &(sensitive_data.keys[o]), NULL), \
1603 p, "pubkey"); \
1604 } while (0)
1605 #define L_CERT(p,o) do { \
1606 if ((o) >= sensitive_data.nkeys) \
1607 fatal_f("cert out of array bounds"); \
1608 check_load(sshkey_load_cert(p, &(sensitive_data.keys[o])), p, "cert"); \
1609 } while (0)
1610
1611 if (options.hostbased_authentication == 1) {
1612 L_CERT(_PATH_HOST_ECDSA_KEY_FILE, 0);
1613 L_CERT(_PATH_HOST_ED25519_KEY_FILE, 1);
1614 L_CERT(_PATH_HOST_RSA_KEY_FILE, 2);
1615 L_CERT(_PATH_HOST_DSA_KEY_FILE, 3);
1616 L_PUBKEY(_PATH_HOST_ECDSA_KEY_FILE, 4);
1617 L_PUBKEY(_PATH_HOST_ED25519_KEY_FILE, 5);
1618 L_PUBKEY(_PATH_HOST_RSA_KEY_FILE, 6);
1619 L_PUBKEY(_PATH_HOST_DSA_KEY_FILE, 7);
1620 L_CERT(_PATH_HOST_XMSS_KEY_FILE, 8);
1621 L_PUBKEY(_PATH_HOST_XMSS_KEY_FILE, 9);
1622 }
1623 }
1624
1625 /* load options.identity_files */
1626 load_public_identity_files(cinfo);
1627
1628 /* optionally set the SSH_AUTHSOCKET_ENV_NAME variable */
1629 if (options.identity_agent &&
1630 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) {
1631 if (strcmp(options.identity_agent, "none") == 0) {
1632 unsetenv(SSH_AUTHSOCKET_ENV_NAME);
1633 } else {
1634 cp = options.identity_agent;
1635 /* legacy (limited) format */
1636 if (cp[0] == '$' && cp[1] != '{') {
1637 if (!valid_env_name(cp + 1)) {
1638 fatal("Invalid IdentityAgent "
1639 "environment variable name %s", cp);
1640 }
1641 if ((p = getenv(cp + 1)) == NULL)
1642 unsetenv(SSH_AUTHSOCKET_ENV_NAME);
1643 else
1644 setenv(SSH_AUTHSOCKET_ENV_NAME, p, 1);
1645 } else {
1646 /* identity_agent specifies a path directly */
1647 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1);
1648 }
1649 }
1650 }
1651
1652 if (options.forward_agent && options.forward_agent_sock_path != NULL) {
1653 cp = options.forward_agent_sock_path;
1654 if (cp[0] == '$') {
1655 if (!valid_env_name(cp + 1)) {
1656 fatal("Invalid ForwardAgent environment variable name %s", cp);
1657 }
1658 if ((p = getenv(cp + 1)) != NULL)
1659 forward_agent_sock_path = xstrdup(p);
1660 else
1661 options.forward_agent = 0;
1662 free(cp);
1663 } else {
1664 forward_agent_sock_path = cp;
1665 }
1666 }
1667
1668 /* Expand ~ in known host file names. */
1669 tilde_expand_paths(options.system_hostfiles,
1670 options.num_system_hostfiles);
1671 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles);
1672
1673 ssh_signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
1674 ssh_signal(SIGCHLD, main_sigchld_handler);
1675
1676 /* Log into the remote system. Never returns if the login fails. */
1677 ssh_login(ssh, &sensitive_data, host, (struct sockaddr *)&hostaddr,
1678 options.port, pw, timeout_ms, cinfo);
1679
1680 /* We no longer need the private host keys. Clear them now. */
1681 if (sensitive_data.nkeys != 0) {
1682 for (i = 0; i < sensitive_data.nkeys; i++) {
1683 if (sensitive_data.keys[i] != NULL) {
1684 /* Destroys contents safely */
1685 debug3("clear hostkey %d", i);
1686 sshkey_free(sensitive_data.keys[i]);
1687 sensitive_data.keys[i] = NULL;
1688 }
1689 }
1690 free(sensitive_data.keys);
1691 }
1692 for (i = 0; i < options.num_identity_files; i++) {
1693 free(options.identity_files[i]);
1694 options.identity_files[i] = NULL;
1695 if (options.identity_keys[i]) {
1696 sshkey_free(options.identity_keys[i]);
1697 options.identity_keys[i] = NULL;
1698 }
1699 }
1700 for (i = 0; i < options.num_certificate_files; i++) {
1701 free(options.certificate_files[i]);
1702 options.certificate_files[i] = NULL;
1703 }
1704
1705 #ifdef ENABLE_PKCS11
1706 (void)pkcs11_del_provider(options.pkcs11_provider);
1707 #endif
1708
1709 skip_connect:
1710 exit_status = ssh_session2(ssh, cinfo);
1711 ssh_conn_info_free(cinfo);
1712 ssh_packet_close(ssh);
1713
1714 if (options.control_path != NULL && muxserver_sock != -1)
1715 unlink(options.control_path);
1716
1717 /* Kill ProxyCommand if it is running. */
1718 ssh_kill_proxy_command();
1719
1720 return exit_status;
1721 }
1722
1723 static void
control_persist_detach(void)1724 control_persist_detach(void)
1725 {
1726 pid_t pid;
1727
1728 debug_f("backgrounding master process");
1729
1730 /*
1731 * master (current process) into the background, and make the
1732 * foreground process a client of the backgrounded master.
1733 */
1734 switch ((pid = fork())) {
1735 case -1:
1736 fatal_f("fork: %s", strerror(errno));
1737 case 0:
1738 /* Child: master process continues mainloop */
1739 break;
1740 default:
1741 /* Parent: set up mux client to connect to backgrounded master */
1742 debug2_f("background process is %ld", (long)pid);
1743 options.stdin_null = ostdin_null_flag;
1744 options.request_tty = orequest_tty;
1745 tty_flag = otty_flag;
1746 options.session_type = osession_type;
1747 close(muxserver_sock);
1748 muxserver_sock = -1;
1749 options.control_master = SSHCTL_MASTER_NO;
1750 muxclient(options.control_path);
1751 /* muxclient() doesn't return on success. */
1752 fatal("Failed to connect to new control master");
1753 }
1754 if (stdfd_devnull(1, 1, !(log_is_on_stderr() && debug_flag)) == -1)
1755 error_f("stdfd_devnull failed");
1756 daemon(1, 1);
1757 setproctitle("%s [mux]", options.control_path);
1758 }
1759
1760 /* Do fork() after authentication. Used by "ssh -f" */
1761 static void
fork_postauth(void)1762 fork_postauth(void)
1763 {
1764 if (need_controlpersist_detach)
1765 control_persist_detach();
1766 debug("forking to background");
1767 options.fork_after_authentication = 0;
1768 if (daemon(1, 1) == -1)
1769 fatal("daemon() failed: %.200s", strerror(errno));
1770 if (stdfd_devnull(1, 1, !(log_is_on_stderr() && debug_flag)) == -1)
1771 error_f("stdfd_devnull failed");
1772 }
1773
1774 static void
forwarding_success(void)1775 forwarding_success(void)
1776 {
1777 if (forward_confirms_pending == -1)
1778 return;
1779 if (--forward_confirms_pending == 0) {
1780 debug_f("all expected forwarding replies received");
1781 if (options.fork_after_authentication)
1782 fork_postauth();
1783 } else {
1784 debug2_f("%d expected forwarding replies remaining",
1785 forward_confirms_pending);
1786 }
1787 }
1788
1789 /* Callback for remote forward global requests */
1790 static void
ssh_confirm_remote_forward(struct ssh * ssh,int type,u_int32_t seq,void * ctxt)1791 ssh_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt)
1792 {
1793 struct Forward *rfwd = (struct Forward *)ctxt;
1794 u_int port;
1795 int r;
1796
1797 /* XXX verbose() on failure? */
1798 debug("remote forward %s for: listen %s%s%d, connect %s:%d",
1799 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1800 rfwd->listen_path ? rfwd->listen_path :
1801 rfwd->listen_host ? rfwd->listen_host : "",
1802 (rfwd->listen_path || rfwd->listen_host) ? ":" : "",
1803 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path :
1804 rfwd->connect_host, rfwd->connect_port);
1805 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) {
1806 if (type == SSH2_MSG_REQUEST_SUCCESS) {
1807 if ((r = sshpkt_get_u32(ssh, &port)) != 0)
1808 fatal_fr(r, "parse packet");
1809 if (port > 65535) {
1810 error("Invalid allocated port %u for remote "
1811 "forward to %s:%d", port,
1812 rfwd->connect_host, rfwd->connect_port);
1813 /* Ensure failure processing runs below */
1814 type = SSH2_MSG_REQUEST_FAILURE;
1815 channel_update_permission(ssh,
1816 rfwd->handle, -1);
1817 } else {
1818 rfwd->allocated_port = (int)port;
1819 logit("Allocated port %u for remote "
1820 "forward to %s:%d",
1821 rfwd->allocated_port, rfwd->connect_path ?
1822 rfwd->connect_path : rfwd->connect_host,
1823 rfwd->connect_port);
1824 channel_update_permission(ssh,
1825 rfwd->handle, rfwd->allocated_port);
1826 }
1827 } else {
1828 channel_update_permission(ssh, rfwd->handle, -1);
1829 }
1830 }
1831
1832 if (type == SSH2_MSG_REQUEST_FAILURE) {
1833 if (options.exit_on_forward_failure) {
1834 if (rfwd->listen_path != NULL)
1835 fatal("Error: remote port forwarding failed "
1836 "for listen path %s", rfwd->listen_path);
1837 else
1838 fatal("Error: remote port forwarding failed "
1839 "for listen port %d", rfwd->listen_port);
1840 } else {
1841 if (rfwd->listen_path != NULL)
1842 logit("Warning: remote port forwarding failed "
1843 "for listen path %s", rfwd->listen_path);
1844 else
1845 logit("Warning: remote port forwarding failed "
1846 "for listen port %d", rfwd->listen_port);
1847 }
1848 }
1849 forwarding_success();
1850 }
1851
1852 static void
client_cleanup_stdio_fwd(struct ssh * ssh,int id,void * arg)1853 client_cleanup_stdio_fwd(struct ssh *ssh, int id, void *arg)
1854 {
1855 debug("stdio forwarding: done");
1856 cleanup_exit(0);
1857 }
1858
1859 static void
ssh_stdio_confirm(struct ssh * ssh,int id,int success,void * arg)1860 ssh_stdio_confirm(struct ssh *ssh, int id, int success, void *arg)
1861 {
1862 if (!success)
1863 fatal("stdio forwarding failed");
1864 }
1865
1866 static void
ssh_tun_confirm(struct ssh * ssh,int id,int success,void * arg)1867 ssh_tun_confirm(struct ssh *ssh, int id, int success, void *arg)
1868 {
1869 if (!success) {
1870 error("Tunnel forwarding failed");
1871 if (options.exit_on_forward_failure)
1872 cleanup_exit(255);
1873 }
1874
1875 debug_f("tunnel forward established, id=%d", id);
1876 forwarding_success();
1877 }
1878
1879 static void
ssh_init_stdio_forwarding(struct ssh * ssh)1880 ssh_init_stdio_forwarding(struct ssh *ssh)
1881 {
1882 Channel *c;
1883 int in, out;
1884
1885 if (options.stdio_forward_host == NULL)
1886 return;
1887
1888 debug3_f("%s:%d", options.stdio_forward_host,
1889 options.stdio_forward_port);
1890
1891 if ((in = dup(STDIN_FILENO)) == -1 ||
1892 (out = dup(STDOUT_FILENO)) == -1)
1893 fatal_f("dup() in/out failed");
1894 if ((c = channel_connect_stdio_fwd(ssh, options.stdio_forward_host,
1895 options.stdio_forward_port, in, out,
1896 CHANNEL_NONBLOCK_STDIO)) == NULL)
1897 fatal_f("channel_connect_stdio_fwd failed");
1898 channel_register_cleanup(ssh, c->self, client_cleanup_stdio_fwd, 0);
1899 channel_register_open_confirm(ssh, c->self, ssh_stdio_confirm, NULL);
1900 }
1901
1902 static void
ssh_init_forward_permissions(struct ssh * ssh,const char * what,char ** opens,u_int num_opens)1903 ssh_init_forward_permissions(struct ssh *ssh, const char *what, char **opens,
1904 u_int num_opens)
1905 {
1906 u_int i;
1907 int port;
1908 char *addr, *arg, *oarg, ch;
1909 int where = FORWARD_LOCAL;
1910
1911 channel_clear_permission(ssh, FORWARD_ADM, where);
1912 if (num_opens == 0)
1913 return; /* permit any */
1914
1915 /* handle keywords: "any" / "none" */
1916 if (num_opens == 1 && strcmp(opens[0], "any") == 0)
1917 return;
1918 if (num_opens == 1 && strcmp(opens[0], "none") == 0) {
1919 channel_disable_admin(ssh, where);
1920 return;
1921 }
1922 /* Otherwise treat it as a list of permitted host:port */
1923 for (i = 0; i < num_opens; i++) {
1924 oarg = arg = xstrdup(opens[i]);
1925 ch = '\0';
1926 addr = hpdelim2(&arg, &ch);
1927 if (addr == NULL || ch == '/')
1928 fatal_f("missing host in %s", what);
1929 addr = cleanhostname(addr);
1930 if (arg == NULL || ((port = permitopen_port(arg)) < 0))
1931 fatal_f("bad port number in %s", what);
1932 /* Send it to channels layer */
1933 channel_add_permission(ssh, FORWARD_ADM,
1934 where, addr, port);
1935 free(oarg);
1936 }
1937 }
1938
1939 static void
ssh_init_forwarding(struct ssh * ssh,char ** ifname)1940 ssh_init_forwarding(struct ssh *ssh, char **ifname)
1941 {
1942 int success = 0;
1943 int i;
1944
1945 ssh_init_forward_permissions(ssh, "permitremoteopen",
1946 options.permitted_remote_opens,
1947 options.num_permitted_remote_opens);
1948
1949 if (options.exit_on_forward_failure)
1950 forward_confirms_pending = 0; /* track pending requests */
1951 /* Initiate local TCP/IP port forwardings. */
1952 for (i = 0; i < options.num_local_forwards; i++) {
1953 debug("Local connections to %.200s:%d forwarded to remote "
1954 "address %.200s:%d",
1955 (options.local_forwards[i].listen_path != NULL) ?
1956 options.local_forwards[i].listen_path :
1957 (options.local_forwards[i].listen_host == NULL) ?
1958 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1959 options.local_forwards[i].listen_host,
1960 options.local_forwards[i].listen_port,
1961 (options.local_forwards[i].connect_path != NULL) ?
1962 options.local_forwards[i].connect_path :
1963 options.local_forwards[i].connect_host,
1964 options.local_forwards[i].connect_port);
1965 success += channel_setup_local_fwd_listener(ssh,
1966 &options.local_forwards[i], &options.fwd_opts);
1967 }
1968 if (i > 0 && success != i && options.exit_on_forward_failure)
1969 fatal("Could not request local forwarding.");
1970 if (i > 0 && success == 0)
1971 error("Could not request local forwarding.");
1972
1973 /* Initiate remote TCP/IP port forwardings. */
1974 for (i = 0; i < options.num_remote_forwards; i++) {
1975 debug("Remote connections from %.200s:%d forwarded to "
1976 "local address %.200s:%d",
1977 (options.remote_forwards[i].listen_path != NULL) ?
1978 options.remote_forwards[i].listen_path :
1979 (options.remote_forwards[i].listen_host == NULL) ?
1980 "LOCALHOST" : options.remote_forwards[i].listen_host,
1981 options.remote_forwards[i].listen_port,
1982 (options.remote_forwards[i].connect_path != NULL) ?
1983 options.remote_forwards[i].connect_path :
1984 options.remote_forwards[i].connect_host,
1985 options.remote_forwards[i].connect_port);
1986 if ((options.remote_forwards[i].handle =
1987 channel_request_remote_forwarding(ssh,
1988 &options.remote_forwards[i])) >= 0) {
1989 client_register_global_confirm(
1990 ssh_confirm_remote_forward,
1991 &options.remote_forwards[i]);
1992 forward_confirms_pending++;
1993 } else if (options.exit_on_forward_failure)
1994 fatal("Could not request remote forwarding.");
1995 else
1996 logit("Warning: Could not request remote forwarding.");
1997 }
1998
1999 /* Initiate tunnel forwarding. */
2000 if (options.tun_open != SSH_TUNMODE_NO) {
2001 if ((*ifname = client_request_tun_fwd(ssh,
2002 options.tun_open, options.tun_local,
2003 options.tun_remote, ssh_tun_confirm, NULL)) != NULL)
2004 forward_confirms_pending++;
2005 else if (options.exit_on_forward_failure)
2006 fatal("Could not request tunnel forwarding.");
2007 else
2008 error("Could not request tunnel forwarding.");
2009 }
2010 if (forward_confirms_pending > 0) {
2011 debug_f("expecting replies for %d forwards",
2012 forward_confirms_pending);
2013 }
2014 }
2015
2016 static void
check_agent_present(void)2017 check_agent_present(void)
2018 {
2019 int r;
2020
2021 if (options.forward_agent) {
2022 /* Clear agent forwarding if we don't have an agent. */
2023 if ((r = ssh_get_authentication_socket(NULL)) != 0) {
2024 options.forward_agent = 0;
2025 if (r != SSH_ERR_AGENT_NOT_PRESENT)
2026 debug_r(r, "ssh_get_authentication_socket");
2027 }
2028 }
2029 }
2030
2031 static void
ssh_session2_setup(struct ssh * ssh,int id,int success,void * arg)2032 ssh_session2_setup(struct ssh *ssh, int id, int success, void *arg)
2033 {
2034 extern char **environ;
2035 const char *display, *term;
2036 int r, interactive = tty_flag;
2037 char *proto = NULL, *data = NULL;
2038
2039 if (!success)
2040 return; /* No need for error message, channels code sens one */
2041
2042 display = getenv("DISPLAY");
2043 if (display == NULL && options.forward_x11)
2044 debug("X11 forwarding requested but DISPLAY not set");
2045 if (options.forward_x11 && client_x11_get_proto(ssh, display,
2046 options.xauth_location, options.forward_x11_trusted,
2047 options.forward_x11_timeout, &proto, &data) == 0) {
2048 /* Request forwarding with authentication spoofing. */
2049 debug("Requesting X11 forwarding with authentication "
2050 "spoofing.");
2051 x11_request_forwarding_with_spoofing(ssh, id, display, proto,
2052 data, 1);
2053 client_expect_confirm(ssh, id, "X11 forwarding", CONFIRM_WARN);
2054 /* XXX exit_on_forward_failure */
2055 interactive = 1;
2056 }
2057
2058 check_agent_present();
2059 if (options.forward_agent) {
2060 debug("Requesting authentication agent forwarding.");
2061 channel_request_start(ssh, id, "[email protected]", 0);
2062 if ((r = sshpkt_send(ssh)) != 0)
2063 fatal_fr(r, "send packet");
2064 }
2065
2066 /* Tell the packet module whether this is an interactive session. */
2067 ssh_packet_set_interactive(ssh, interactive,
2068 options.ip_qos_interactive, options.ip_qos_bulk);
2069
2070 if ((term = lookup_env_in_list("TERM", options.setenv,
2071 options.num_setenv)) == NULL || *term == '\0')
2072 term = getenv("TERM");
2073 client_session2_setup(ssh, id, tty_flag,
2074 options.session_type == SESSION_TYPE_SUBSYSTEM, term,
2075 NULL, fileno(stdin), command, environ);
2076 }
2077
2078 /* open new channel for a session */
2079 static int
ssh_session2_open(struct ssh * ssh)2080 ssh_session2_open(struct ssh *ssh)
2081 {
2082 Channel *c;
2083 int window, packetmax, in, out, err;
2084
2085 if (options.stdin_null) {
2086 in = open(_PATH_DEVNULL, O_RDONLY);
2087 } else {
2088 in = dup(STDIN_FILENO);
2089 }
2090 out = dup(STDOUT_FILENO);
2091 err = dup(STDERR_FILENO);
2092
2093 if (in == -1 || out == -1 || err == -1)
2094 fatal("dup() in/out/err failed");
2095
2096 window = CHAN_SES_WINDOW_DEFAULT;
2097 packetmax = CHAN_SES_PACKET_DEFAULT;
2098 if (tty_flag) {
2099 window >>= 1;
2100 packetmax >>= 1;
2101 }
2102 c = channel_new(ssh,
2103 "session", SSH_CHANNEL_OPENING, in, out, err,
2104 window, packetmax, CHAN_EXTENDED_WRITE,
2105 "client-session", CHANNEL_NONBLOCK_STDIO);
2106
2107 debug3_f("channel_new: %d", c->self);
2108
2109 channel_send_open(ssh, c->self);
2110 if (options.session_type != SESSION_TYPE_NONE)
2111 channel_register_open_confirm(ssh, c->self,
2112 ssh_session2_setup, NULL);
2113
2114 return c->self;
2115 }
2116
2117 static int
ssh_session2(struct ssh * ssh,const struct ssh_conn_info * cinfo)2118 ssh_session2(struct ssh *ssh, const struct ssh_conn_info *cinfo)
2119 {
2120 int r, id = -1;
2121 char *cp, *tun_fwd_ifname = NULL;
2122
2123 /* XXX should be pre-session */
2124 if (!options.control_persist)
2125 ssh_init_stdio_forwarding(ssh);
2126
2127 ssh_init_forwarding(ssh, &tun_fwd_ifname);
2128
2129 if (options.local_command != NULL) {
2130 debug3("expanding LocalCommand: %s", options.local_command);
2131 cp = options.local_command;
2132 options.local_command = percent_expand(cp,
2133 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo),
2134 "T", tun_fwd_ifname == NULL ? "NONE" : tun_fwd_ifname,
2135 (char *)NULL);
2136 debug3("expanded LocalCommand: %s", options.local_command);
2137 free(cp);
2138 }
2139
2140 /* Start listening for multiplex clients */
2141 if (!ssh_packet_get_mux(ssh))
2142 muxserver_listen(ssh);
2143
2144 /*
2145 * If we are in control persist mode and have a working mux listen
2146 * socket, then prepare to background ourselves and have a foreground
2147 * client attach as a control client.
2148 * NB. we must save copies of the flags that we override for
2149 * the backgrounding, since we defer attachment of the client until
2150 * after the connection is fully established (in particular,
2151 * async rfwd replies have been received for ExitOnForwardFailure).
2152 */
2153 if (options.control_persist && muxserver_sock != -1) {
2154 ostdin_null_flag = options.stdin_null;
2155 osession_type = options.session_type;
2156 orequest_tty = options.request_tty;
2157 otty_flag = tty_flag;
2158 options.stdin_null = 1;
2159 options.session_type = SESSION_TYPE_NONE;
2160 tty_flag = 0;
2161 if (!options.fork_after_authentication &&
2162 (osession_type != SESSION_TYPE_NONE ||
2163 options.stdio_forward_host != NULL))
2164 need_controlpersist_detach = 1;
2165 options.fork_after_authentication = 1;
2166 }
2167 /*
2168 * ControlPersist mux listen socket setup failed, attempt the
2169 * stdio forward setup that we skipped earlier.
2170 */
2171 if (options.control_persist && muxserver_sock == -1)
2172 ssh_init_stdio_forwarding(ssh);
2173
2174 if (options.session_type != SESSION_TYPE_NONE)
2175 id = ssh_session2_open(ssh);
2176 else {
2177 ssh_packet_set_interactive(ssh,
2178 options.control_master == SSHCTL_MASTER_NO,
2179 options.ip_qos_interactive, options.ip_qos_bulk);
2180 }
2181
2182 /* If we don't expect to open a new session, then disallow it */
2183 if (options.control_master == SSHCTL_MASTER_NO &&
2184 (ssh->compat & SSH_NEW_OPENSSH)) {
2185 debug("Requesting [email protected]");
2186 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
2187 (r = sshpkt_put_cstring(ssh,
2188 "[email protected]")) != 0 ||
2189 (r = sshpkt_put_u8(ssh, 0)) != 0 ||
2190 (r = sshpkt_send(ssh)) != 0)
2191 fatal_fr(r, "send packet");
2192 }
2193
2194 /* Execute a local command */
2195 if (options.local_command != NULL &&
2196 options.permit_local_command)
2197 ssh_local_cmd(options.local_command);
2198
2199 /*
2200 * stdout is now owned by the session channel; clobber it here
2201 * so future channel closes are propagated to the local fd.
2202 * NB. this can only happen after LocalCommand has completed,
2203 * as it may want to write to stdout.
2204 */
2205 if (!need_controlpersist_detach && stdfd_devnull(0, 1, 0) == -1)
2206 error_f("stdfd_devnull failed");
2207
2208 /*
2209 * If requested and we are not interested in replies to remote
2210 * forwarding requests, then let ssh continue in the background.
2211 */
2212 if (options.fork_after_authentication) {
2213 if (options.exit_on_forward_failure &&
2214 options.num_remote_forwards > 0) {
2215 debug("deferring postauth fork until remote forward "
2216 "confirmation received");
2217 } else
2218 fork_postauth();
2219 }
2220
2221 return client_loop(ssh, tty_flag, tty_flag ?
2222 options.escape_char : SSH_ESCAPECHAR_NONE, id);
2223 }
2224
2225 /* Loads all IdentityFile and CertificateFile keys */
2226 static void
load_public_identity_files(const struct ssh_conn_info * cinfo)2227 load_public_identity_files(const struct ssh_conn_info *cinfo)
2228 {
2229 char *filename, *cp;
2230 struct sshkey *public;
2231 int i;
2232 u_int n_ids, n_certs;
2233 char *identity_files[SSH_MAX_IDENTITY_FILES];
2234 struct sshkey *identity_keys[SSH_MAX_IDENTITY_FILES];
2235 int identity_file_userprovided[SSH_MAX_IDENTITY_FILES];
2236 char *certificate_files[SSH_MAX_CERTIFICATE_FILES];
2237 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES];
2238 int certificate_file_userprovided[SSH_MAX_CERTIFICATE_FILES];
2239 #ifdef ENABLE_PKCS11
2240 struct sshkey **keys = NULL;
2241 char **comments = NULL;
2242 int nkeys;
2243 #endif /* PKCS11 */
2244
2245 n_ids = n_certs = 0;
2246 memset(identity_files, 0, sizeof(identity_files));
2247 memset(identity_keys, 0, sizeof(identity_keys));
2248 memset(identity_file_userprovided, 0,
2249 sizeof(identity_file_userprovided));
2250 memset(certificate_files, 0, sizeof(certificate_files));
2251 memset(certificates, 0, sizeof(certificates));
2252 memset(certificate_file_userprovided, 0,
2253 sizeof(certificate_file_userprovided));
2254
2255 #ifdef ENABLE_PKCS11
2256 if (options.pkcs11_provider != NULL &&
2257 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
2258 (pkcs11_init(!options.batch_mode) == 0) &&
2259 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL,
2260 &keys, &comments)) > 0) {
2261 for (i = 0; i < nkeys; i++) {
2262 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
2263 sshkey_free(keys[i]);
2264 free(comments[i]);
2265 continue;
2266 }
2267 identity_keys[n_ids] = keys[i];
2268 identity_files[n_ids] = comments[i]; /* transferred */
2269 n_ids++;
2270 }
2271 free(keys);
2272 free(comments);
2273 }
2274 #endif /* ENABLE_PKCS11 */
2275 for (i = 0; i < options.num_identity_files; i++) {
2276 if (n_ids >= SSH_MAX_IDENTITY_FILES ||
2277 strcasecmp(options.identity_files[i], "none") == 0) {
2278 free(options.identity_files[i]);
2279 options.identity_files[i] = NULL;
2280 continue;
2281 }
2282 cp = tilde_expand_filename(options.identity_files[i], getuid());
2283 filename = default_client_percent_dollar_expand(cp, cinfo);
2284 free(cp);
2285 check_load(sshkey_load_public(filename, &public, NULL),
2286 filename, "pubkey");
2287 debug("identity file %s type %d", filename,
2288 public ? public->type : -1);
2289 free(options.identity_files[i]);
2290 identity_files[n_ids] = filename;
2291 identity_keys[n_ids] = public;
2292 identity_file_userprovided[n_ids] =
2293 options.identity_file_userprovided[i];
2294 if (++n_ids >= SSH_MAX_IDENTITY_FILES)
2295 continue;
2296
2297 /*
2298 * If no certificates have been explicitly listed then try
2299 * to add the default certificate variant too.
2300 */
2301 if (options.num_certificate_files != 0)
2302 continue;
2303 xasprintf(&cp, "%s-cert", filename);
2304 check_load(sshkey_load_public(cp, &public, NULL),
2305 filename, "pubkey");
2306 debug("identity file %s type %d", cp,
2307 public ? public->type : -1);
2308 if (public == NULL) {
2309 free(cp);
2310 continue;
2311 }
2312 if (!sshkey_is_cert(public)) {
2313 debug_f("key %s type %s is not a certificate",
2314 cp, sshkey_type(public));
2315 sshkey_free(public);
2316 free(cp);
2317 continue;
2318 }
2319 /* NB. leave filename pointing to private key */
2320 identity_files[n_ids] = xstrdup(filename);
2321 identity_keys[n_ids] = public;
2322 identity_file_userprovided[n_ids] =
2323 options.identity_file_userprovided[i];
2324 n_ids++;
2325 }
2326
2327 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES)
2328 fatal_f("too many certificates");
2329 for (i = 0; i < options.num_certificate_files; i++) {
2330 cp = tilde_expand_filename(options.certificate_files[i],
2331 getuid());
2332 filename = default_client_percent_dollar_expand(cp, cinfo);
2333 free(cp);
2334
2335 check_load(sshkey_load_public(filename, &public, NULL),
2336 filename, "certificate");
2337 debug("certificate file %s type %d", filename,
2338 public ? public->type : -1);
2339 free(options.certificate_files[i]);
2340 options.certificate_files[i] = NULL;
2341 if (public == NULL) {
2342 free(filename);
2343 continue;
2344 }
2345 if (!sshkey_is_cert(public)) {
2346 debug_f("key %s type %s is not a certificate",
2347 filename, sshkey_type(public));
2348 sshkey_free(public);
2349 free(filename);
2350 continue;
2351 }
2352 certificate_files[n_certs] = filename;
2353 certificates[n_certs] = public;
2354 certificate_file_userprovided[n_certs] =
2355 options.certificate_file_userprovided[i];
2356 ++n_certs;
2357 }
2358
2359 options.num_identity_files = n_ids;
2360 memcpy(options.identity_files, identity_files, sizeof(identity_files));
2361 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys));
2362 memcpy(options.identity_file_userprovided,
2363 identity_file_userprovided, sizeof(identity_file_userprovided));
2364
2365 options.num_certificate_files = n_certs;
2366 memcpy(options.certificate_files,
2367 certificate_files, sizeof(certificate_files));
2368 memcpy(options.certificates, certificates, sizeof(certificates));
2369 memcpy(options.certificate_file_userprovided,
2370 certificate_file_userprovided,
2371 sizeof(certificate_file_userprovided));
2372 }
2373
2374 static void
main_sigchld_handler(int sig)2375 main_sigchld_handler(int sig)
2376 {
2377 int save_errno = errno;
2378 pid_t pid;
2379 int status;
2380
2381 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
2382 (pid == -1 && errno == EINTR))
2383 ;
2384 errno = save_errno;
2385 }
2386