1 /* $OpenBSD: ssh.c,v 1.576 2022/09/17 10:33:18 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 SSLeay 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 <stdarg.h>
69 #include <unistd.h>
70 #include <limits.h>
71 #include <locale.h>
72
73 #include <netinet/in.h>
74 #include <arpa/inet.h>
75
76 #ifdef WITH_OPENSSL
77 #include <openssl/evp.h>
78 #include <openssl/err.h>
79 #endif
80 #include "openbsd-compat/openssl-compat.h"
81 #include "openbsd-compat/sys-queue.h"
82
83 #include "xmalloc.h"
84 #include "ssh.h"
85 #include "ssh2.h"
86 #include "canohost.h"
87 #include "compat.h"
88 #include "cipher.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 /*
130 * Flag indicating that the current process should be backgrounded and
131 * a new mux-client launched in the foreground for ControlPersist.
132 */
133 int need_controlpersist_detach = 0;
134
135 /* Copies of flags for ControlPersist foreground mux-client */
136 int ostdin_null_flag, osession_type, otty_flag, orequest_tty;
137
138 /*
139 * General data structure for command line options and options configurable
140 * in configuration files. See readconf.h.
141 */
142 Options options;
143
144 /* optional user configfile */
145 char *config = NULL;
146
147 /*
148 * Name of the host we are connecting to. This is the name given on the
149 * command line, or the Hostname specified for the user-supplied name in a
150 * configuration file.
151 */
152 char *host;
153
154 /*
155 * A config can specify a path to forward, overriding SSH_AUTH_SOCK. If this is
156 * not NULL, forward the socket at this path instead.
157 */
158 char *forward_agent_sock_path = NULL;
159
160 /* socket address the host resolves to */
161 struct sockaddr_storage hostaddr;
162
163 /* Private host keys. */
164 Sensitive sensitive_data;
165
166 /* command to be executed */
167 struct sshbuf *command;
168
169 /* # of replies received for global requests */
170 static int forward_confirms_pending = -1;
171
172 /* mux.c */
173 extern int muxserver_sock;
174 extern u_int muxclient_command;
175
176 /* Prints a help message to the user. This function never returns. */
177
178 static void
usage(void)179 usage(void)
180 {
181 fprintf(stderr,
182 "usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]\n"
183 " [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]\n"
184 " [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]\n"
185 " [-i identity_file] [-J [user@]host[:port]] [-L address]\n"
186 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
187 " [-Q query_option] [-R address] [-S ctl_path] [-W host:port]\n"
188 " [-w local_tun[:remote_tun]] destination [command [argument ...]]\n"
189 );
190 exit(255);
191 }
192
193 static int ssh_session2(struct ssh *, const struct ssh_conn_info *);
194 static void load_public_identity_files(const struct ssh_conn_info *);
195 static void main_sigchld_handler(int);
196
197 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */
198 static void
tilde_expand_paths(char ** paths,u_int num_paths)199 tilde_expand_paths(char **paths, u_int num_paths)
200 {
201 u_int i;
202 char *cp;
203
204 for (i = 0; i < num_paths; i++) {
205 cp = tilde_expand_filename(paths[i], getuid());
206 free(paths[i]);
207 paths[i] = cp;
208 }
209 }
210
211 /*
212 * Expands the set of percent_expand options used by the majority of keywords
213 * in the client that support percent expansion.
214 * Caller must free returned string.
215 */
216 static char *
default_client_percent_expand(const char * str,const struct ssh_conn_info * cinfo)217 default_client_percent_expand(const char *str,
218 const struct ssh_conn_info *cinfo)
219 {
220 return percent_expand(str,
221 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo),
222 (char *)NULL);
223 }
224
225 /*
226 * Expands the set of percent_expand options used by the majority of keywords
227 * AND perform environment variable substitution.
228 * Caller must free returned string.
229 */
230 static char *
default_client_percent_dollar_expand(const char * str,const struct ssh_conn_info * cinfo)231 default_client_percent_dollar_expand(const char *str,
232 const struct ssh_conn_info *cinfo)
233 {
234 char *ret;
235
236 ret = percent_dollar_expand(str,
237 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo),
238 (char *)NULL);
239 if (ret == NULL)
240 fatal("invalid environment variable expansion");
241 return ret;
242 }
243
244 /*
245 * Attempt to resolve a host name / port to a set of addresses and
246 * optionally return any CNAMEs encountered along the way.
247 * Returns NULL on failure.
248 * NB. this function must operate with a options having undefined members.
249 */
250 static struct addrinfo *
resolve_host(const char * name,int port,int logerr,char * cname,size_t clen)251 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen)
252 {
253 char strport[NI_MAXSERV];
254 struct addrinfo hints, *res;
255 int gaierr;
256 LogLevel loglevel = SYSLOG_LEVEL_DEBUG1;
257
258 if (port <= 0)
259 port = default_ssh_port();
260 if (cname != NULL)
261 *cname = '\0';
262 debug3_f("lookup %s:%d", name, port);
263
264 snprintf(strport, sizeof strport, "%d", port);
265 memset(&hints, 0, sizeof(hints));
266 hints.ai_family = options.address_family == -1 ?
267 AF_UNSPEC : options.address_family;
268 hints.ai_socktype = SOCK_STREAM;
269 if (cname != NULL)
270 hints.ai_flags = AI_CANONNAME;
271 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
272 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA))
273 loglevel = SYSLOG_LEVEL_ERROR;
274 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s",
275 __progname, name, ssh_gai_strerror(gaierr));
276 return NULL;
277 }
278 if (cname != NULL && res->ai_canonname != NULL) {
279 if (strlcpy(cname, res->ai_canonname, clen) >= clen) {
280 error_f("host \"%s\" cname \"%s\" too long (max %lu)",
281 name, res->ai_canonname, (u_long)clen);
282 if (clen > 0)
283 *cname = '\0';
284 }
285 }
286 return res;
287 }
288
289 /* Returns non-zero if name can only be an address and not a hostname */
290 static int
is_addr_fast(const char * name)291 is_addr_fast(const char *name)
292 {
293 return (strchr(name, '%') != NULL || strchr(name, ':') != NULL ||
294 strspn(name, "0123456789.") == strlen(name));
295 }
296
297 /* Returns non-zero if name represents a valid, single address */
298 static int
is_addr(const char * name)299 is_addr(const char *name)
300 {
301 char strport[NI_MAXSERV];
302 struct addrinfo hints, *res;
303
304 if (is_addr_fast(name))
305 return 1;
306
307 snprintf(strport, sizeof strport, "%u", default_ssh_port());
308 memset(&hints, 0, sizeof(hints));
309 hints.ai_family = options.address_family == -1 ?
310 AF_UNSPEC : options.address_family;
311 hints.ai_socktype = SOCK_STREAM;
312 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV;
313 if (getaddrinfo(name, strport, &hints, &res) != 0)
314 return 0;
315 if (res == NULL || res->ai_next != NULL) {
316 freeaddrinfo(res);
317 return 0;
318 }
319 freeaddrinfo(res);
320 return 1;
321 }
322
323 /*
324 * Attempt to resolve a numeric host address / port to a single address.
325 * Returns a canonical address string.
326 * Returns NULL on failure.
327 * NB. this function must operate with a options having undefined members.
328 */
329 static struct addrinfo *
resolve_addr(const char * name,int port,char * caddr,size_t clen)330 resolve_addr(const char *name, int port, char *caddr, size_t clen)
331 {
332 char addr[NI_MAXHOST], strport[NI_MAXSERV];
333 struct addrinfo hints, *res;
334 int gaierr;
335
336 if (port <= 0)
337 port = default_ssh_port();
338 snprintf(strport, sizeof strport, "%u", port);
339 memset(&hints, 0, sizeof(hints));
340 hints.ai_family = options.address_family == -1 ?
341 AF_UNSPEC : options.address_family;
342 hints.ai_socktype = SOCK_STREAM;
343 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV;
344 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
345 debug2_f("could not resolve name %.100s as address: %s",
346 name, ssh_gai_strerror(gaierr));
347 return NULL;
348 }
349 if (res == NULL) {
350 debug_f("getaddrinfo %.100s returned no addresses", name);
351 return NULL;
352 }
353 if (res->ai_next != NULL) {
354 debug_f("getaddrinfo %.100s returned multiple addresses", name);
355 goto fail;
356 }
357 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen,
358 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) {
359 debug_f("Could not format address for name %.100s: %s",
360 name, ssh_gai_strerror(gaierr));
361 goto fail;
362 }
363 if (strlcpy(caddr, addr, clen) >= clen) {
364 error_f("host \"%s\" addr \"%s\" too long (max %lu)",
365 name, addr, (u_long)clen);
366 if (clen > 0)
367 *caddr = '\0';
368 fail:
369 freeaddrinfo(res);
370 return NULL;
371 }
372 return res;
373 }
374
375 /*
376 * Check whether the cname is a permitted replacement for the hostname
377 * and perform the replacement if it is.
378 * NB. this function must operate with a options having undefined members.
379 */
380 static int
check_follow_cname(int direct,char ** namep,const char * cname)381 check_follow_cname(int direct, char **namep, const char *cname)
382 {
383 int i;
384 struct allowed_cname *rule;
385
386 if (*cname == '\0' || !config_has_permitted_cnames(&options) ||
387 strcmp(*namep, cname) == 0)
388 return 0;
389 if (options.canonicalize_hostname == SSH_CANONICALISE_NO)
390 return 0;
391 /*
392 * Don't attempt to canonicalize names that will be interpreted by
393 * a proxy or jump host unless the user specifically requests so.
394 */
395 if (!direct &&
396 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
397 return 0;
398 debug3_f("check \"%s\" CNAME \"%s\"", *namep, cname);
399 for (i = 0; i < options.num_permitted_cnames; i++) {
400 rule = options.permitted_cnames + i;
401 if (match_pattern_list(*namep, rule->source_list, 1) != 1 ||
402 match_pattern_list(cname, rule->target_list, 1) != 1)
403 continue;
404 verbose("Canonicalized DNS aliased hostname "
405 "\"%s\" => \"%s\"", *namep, cname);
406 free(*namep);
407 *namep = xstrdup(cname);
408 return 1;
409 }
410 return 0;
411 }
412
413 /*
414 * Attempt to resolve the supplied hostname after applying the user's
415 * canonicalization rules. Returns the address list for the host or NULL
416 * if no name was found after canonicalization.
417 * NB. this function must operate with a options having undefined members.
418 */
419 static struct addrinfo *
resolve_canonicalize(char ** hostp,int port)420 resolve_canonicalize(char **hostp, int port)
421 {
422 int i, direct, ndots;
423 char *cp, *fullhost, newname[NI_MAXHOST];
424 struct addrinfo *addrs;
425
426 /*
427 * Attempt to canonicalise addresses, regardless of
428 * whether hostname canonicalisation was requested
429 */
430 if ((addrs = resolve_addr(*hostp, port,
431 newname, sizeof(newname))) != NULL) {
432 debug2_f("hostname %.100s is address", *hostp);
433 if (strcasecmp(*hostp, newname) != 0) {
434 debug2_f("canonicalised address \"%s\" => \"%s\"",
435 *hostp, newname);
436 free(*hostp);
437 *hostp = xstrdup(newname);
438 }
439 return addrs;
440 }
441
442 /*
443 * If this looks like an address but didn't parse as one, it might
444 * be an address with an invalid interface scope. Skip further
445 * attempts at canonicalisation.
446 */
447 if (is_addr_fast(*hostp)) {
448 debug_f("hostname %.100s is an unrecognised address", *hostp);
449 return NULL;
450 }
451
452 if (options.canonicalize_hostname == SSH_CANONICALISE_NO)
453 return NULL;
454
455 /*
456 * Don't attempt to canonicalize names that will be interpreted by
457 * a proxy unless the user specifically requests so.
458 */
459 direct = option_clear_or_none(options.proxy_command) &&
460 options.jump_host == NULL;
461 if (!direct &&
462 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
463 return NULL;
464
465 /* If domain name is anchored, then resolve it now */
466 if ((*hostp)[strlen(*hostp) - 1] == '.') {
467 debug3_f("name is fully qualified");
468 fullhost = xstrdup(*hostp);
469 if ((addrs = resolve_host(fullhost, port, 0,
470 newname, sizeof(newname))) != NULL)
471 goto found;
472 free(fullhost);
473 goto notfound;
474 }
475
476 /* Don't apply canonicalization to sufficiently-qualified hostnames */
477 ndots = 0;
478 for (cp = *hostp; *cp != '\0'; cp++) {
479 if (*cp == '.')
480 ndots++;
481 }
482 if (ndots > options.canonicalize_max_dots) {
483 debug3_f("not canonicalizing hostname \"%s\" (max dots %d)",
484 *hostp, options.canonicalize_max_dots);
485 return NULL;
486 }
487 /* Attempt each supplied suffix */
488 for (i = 0; i < options.num_canonical_domains; i++) {
489 if (strcasecmp(options.canonical_domains[i], "none") == 0)
490 break;
491 xasprintf(&fullhost, "%s.%s.", *hostp,
492 options.canonical_domains[i]);
493 debug3_f("attempting \"%s\" => \"%s\"", *hostp, fullhost);
494 if ((addrs = resolve_host(fullhost, port, 0,
495 newname, sizeof(newname))) == NULL) {
496 free(fullhost);
497 continue;
498 }
499 found:
500 /* Remove trailing '.' */
501 fullhost[strlen(fullhost) - 1] = '\0';
502 /* Follow CNAME if requested */
503 if (!check_follow_cname(direct, &fullhost, newname)) {
504 debug("Canonicalized hostname \"%s\" => \"%s\"",
505 *hostp, fullhost);
506 }
507 free(*hostp);
508 *hostp = fullhost;
509 return addrs;
510 }
511 notfound:
512 if (!options.canonicalize_fallback_local)
513 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp);
514 debug2_f("host %s not found in any suffix", *hostp);
515 return NULL;
516 }
517
518 /*
519 * Check the result of hostkey loading, ignoring some errors and either
520 * discarding the key or fatal()ing for others.
521 */
522 static void
check_load(int r,struct sshkey ** k,const char * path,const char * message)523 check_load(int r, struct sshkey **k, const char *path, const char *message)
524 {
525 switch (r) {
526 case 0:
527 /* Check RSA keys size and discard if undersized */
528 if (k != NULL && *k != NULL &&
529 (r = sshkey_check_rsa_length(*k,
530 options.required_rsa_size)) != 0) {
531 error_r(r, "load %s \"%s\"", message, path);
532 free(*k);
533 *k = NULL;
534 }
535 break;
536 case SSH_ERR_INTERNAL_ERROR:
537 case SSH_ERR_ALLOC_FAIL:
538 fatal_r(r, "load %s \"%s\"", message, path);
539 case SSH_ERR_SYSTEM_ERROR:
540 /* Ignore missing files */
541 if (errno == ENOENT)
542 break;
543 /* FALLTHROUGH */
544 default:
545 error_r(r, "load %s \"%s\"", message, path);
546 break;
547 }
548 }
549
550 /*
551 * Read per-user configuration file. Ignore the system wide config
552 * file if the user specifies a config file on the command line.
553 */
554 static void
process_config_files(const char * host_name,struct passwd * pw,int final_pass,int * want_final_pass)555 process_config_files(const char *host_name, struct passwd *pw, int final_pass,
556 int *want_final_pass)
557 {
558 char buf[PATH_MAX];
559 int r;
560
561 if (config != NULL) {
562 if (strcasecmp(config, "none") != 0 &&
563 !read_config_file(config, pw, host, host_name, &options,
564 SSHCONF_USERCONF | (final_pass ? SSHCONF_FINAL : 0),
565 want_final_pass))
566 fatal("Can't open user config file %.100s: "
567 "%.100s", config, strerror(errno));
568 } else {
569 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
570 _PATH_SSH_USER_CONFFILE);
571 if (r > 0 && (size_t)r < sizeof(buf))
572 (void)read_config_file(buf, pw, host, host_name,
573 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF |
574 (final_pass ? SSHCONF_FINAL : 0), want_final_pass);
575
576 /* Read systemwide configuration file after user config. */
577 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw,
578 host, host_name, &options,
579 final_pass ? SSHCONF_FINAL : 0, want_final_pass);
580 }
581 }
582
583 /* Rewrite the port number in an addrinfo list of addresses */
584 static void
set_addrinfo_port(struct addrinfo * addrs,int port)585 set_addrinfo_port(struct addrinfo *addrs, int port)
586 {
587 struct addrinfo *addr;
588
589 for (addr = addrs; addr != NULL; addr = addr->ai_next) {
590 switch (addr->ai_family) {
591 case AF_INET:
592 ((struct sockaddr_in *)addr->ai_addr)->
593 sin_port = htons(port);
594 break;
595 case AF_INET6:
596 ((struct sockaddr_in6 *)addr->ai_addr)->
597 sin6_port = htons(port);
598 break;
599 }
600 }
601 }
602
603 static void
ssh_conn_info_free(struct ssh_conn_info * cinfo)604 ssh_conn_info_free(struct ssh_conn_info *cinfo)
605 {
606 if (cinfo == NULL)
607 return;
608 free(cinfo->conn_hash_hex);
609 free(cinfo->shorthost);
610 free(cinfo->uidstr);
611 free(cinfo->keyalias);
612 free(cinfo->thishost);
613 free(cinfo->host_arg);
614 free(cinfo->portstr);
615 free(cinfo->remhost);
616 free(cinfo->remuser);
617 free(cinfo->homedir);
618 free(cinfo->locuser);
619 free(cinfo);
620 }
621
622 /*
623 * Main program for the ssh client.
624 */
625 int
main(int ac,char ** av)626 main(int ac, char **av)
627 {
628 struct ssh *ssh = NULL;
629 int i, r, opt, exit_status, use_syslog, direct, timeout_ms;
630 int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0;
631 char *p, *cp, *line, *argv0, *logfile, *host_arg;
632 char cname[NI_MAXHOST], thishost[NI_MAXHOST];
633 struct stat st;
634 struct passwd *pw;
635 extern int optind, optreset;
636 extern char *optarg;
637 struct Forward fwd;
638 struct addrinfo *addrs = NULL;
639 size_t n, len;
640 u_int j;
641 struct ssh_conn_info *cinfo = NULL;
642
643 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
644 sanitise_stdfd();
645
646 /*
647 * Discard other fds that are hanging around. These can cause problem
648 * with backgrounded ssh processes started by ControlPersist.
649 */
650 closefrom(STDERR_FILENO + 1);
651
652 __progname = ssh_get_progname(av[0]);
653
654 #ifndef HAVE_SETPROCTITLE
655 /* Prepare for later setproctitle emulation */
656 /* Save argv so it isn't clobbered by setproctitle() emulation */
657 saved_av = xcalloc(ac + 1, sizeof(*saved_av));
658 for (i = 0; i < ac; i++)
659 saved_av[i] = xstrdup(av[i]);
660 saved_av[i] = NULL;
661 compat_init_setproctitle(ac, av);
662 av = saved_av;
663 #endif
664
665 seed_rng();
666
667 /* Get user data. */
668 pw = getpwuid(getuid());
669 if (!pw) {
670 logit("No user exists for uid %lu", (u_long)getuid());
671 exit(255);
672 }
673 /* Take a copy of the returned structure. */
674 pw = pwcopy(pw);
675
676 /*
677 * Set our umask to something reasonable, as some files are created
678 * with the default umask. This will make them world-readable but
679 * writable only by the owner, which is ok for all files for which we
680 * don't set the modes explicitly.
681 */
682 umask(022);
683
684 msetlocale();
685
686 /*
687 * Initialize option structure to indicate that no values have been
688 * set.
689 */
690 initialize_options(&options);
691
692 /*
693 * Prepare main ssh transport/connection structures
694 */
695 if ((ssh = ssh_alloc_session_state()) == NULL)
696 fatal("Couldn't allocate session state");
697 channel_init_channels(ssh);
698
699 /* Parse command-line arguments. */
700 host = NULL;
701 use_syslog = 0;
702 logfile = NULL;
703 argv0 = av[0];
704
705 again:
706 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
707 "AB:CD:E:F:GI:J:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { /* HUZdhjruz */
708 switch (opt) {
709 case '1':
710 fatal("SSH protocol v.1 is no longer supported");
711 break;
712 case '2':
713 /* Ignored */
714 break;
715 case '4':
716 options.address_family = AF_INET;
717 break;
718 case '6':
719 options.address_family = AF_INET6;
720 break;
721 case 'n':
722 options.stdin_null = 1;
723 break;
724 case 'f':
725 options.fork_after_authentication = 1;
726 options.stdin_null = 1;
727 break;
728 case 'x':
729 options.forward_x11 = 0;
730 break;
731 case 'X':
732 options.forward_x11 = 1;
733 break;
734 case 'y':
735 use_syslog = 1;
736 break;
737 case 'E':
738 logfile = optarg;
739 break;
740 case 'G':
741 config_test = 1;
742 break;
743 case 'Y':
744 options.forward_x11 = 1;
745 options.forward_x11_trusted = 1;
746 break;
747 case 'g':
748 options.fwd_opts.gateway_ports = 1;
749 break;
750 case 'O':
751 if (options.stdio_forward_host != NULL)
752 fatal("Cannot specify multiplexing "
753 "command with -W");
754 else if (muxclient_command != 0)
755 fatal("Multiplexing command already specified");
756 if (strcmp(optarg, "check") == 0)
757 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
758 else if (strcmp(optarg, "forward") == 0)
759 muxclient_command = SSHMUX_COMMAND_FORWARD;
760 else if (strcmp(optarg, "exit") == 0)
761 muxclient_command = SSHMUX_COMMAND_TERMINATE;
762 else if (strcmp(optarg, "stop") == 0)
763 muxclient_command = SSHMUX_COMMAND_STOP;
764 else if (strcmp(optarg, "cancel") == 0)
765 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD;
766 else if (strcmp(optarg, "proxy") == 0)
767 muxclient_command = SSHMUX_COMMAND_PROXY;
768 else
769 fatal("Invalid multiplex command.");
770 break;
771 case 'P': /* deprecated */
772 break;
773 case 'Q':
774 cp = NULL;
775 if (strcmp(optarg, "cipher") == 0 ||
776 strcasecmp(optarg, "Ciphers") == 0)
777 cp = cipher_alg_list('\n', 0);
778 else if (strcmp(optarg, "cipher-auth") == 0)
779 cp = cipher_alg_list('\n', 1);
780 else if (strcmp(optarg, "mac") == 0 ||
781 strcasecmp(optarg, "MACs") == 0)
782 cp = mac_alg_list('\n');
783 else if (strcmp(optarg, "kex") == 0 ||
784 strcasecmp(optarg, "KexAlgorithms") == 0)
785 cp = kex_alg_list('\n');
786 else if (strcmp(optarg, "key") == 0)
787 cp = sshkey_alg_list(0, 0, 0, '\n');
788 else if (strcmp(optarg, "key-cert") == 0)
789 cp = sshkey_alg_list(1, 0, 0, '\n');
790 else if (strcmp(optarg, "key-plain") == 0)
791 cp = sshkey_alg_list(0, 1, 0, '\n');
792 else if (strcmp(optarg, "key-sig") == 0 ||
793 strcasecmp(optarg, "PubkeyAcceptedKeyTypes") == 0 || /* deprecated name */
794 strcasecmp(optarg, "PubkeyAcceptedAlgorithms") == 0 ||
795 strcasecmp(optarg, "HostKeyAlgorithms") == 0 ||
796 strcasecmp(optarg, "HostbasedKeyTypes") == 0 || /* deprecated name */
797 strcasecmp(optarg, "HostbasedAcceptedKeyTypes") == 0 || /* deprecated name */
798 strcasecmp(optarg, "HostbasedAcceptedAlgorithms") == 0)
799 cp = sshkey_alg_list(0, 0, 1, '\n');
800 else if (strcmp(optarg, "sig") == 0)
801 cp = sshkey_alg_list(0, 1, 1, '\n');
802 else if (strcmp(optarg, "protocol-version") == 0)
803 cp = xstrdup("2");
804 else if (strcmp(optarg, "compression") == 0) {
805 cp = xstrdup(compression_alg_list(0));
806 len = strlen(cp);
807 for (n = 0; n < len; n++)
808 if (cp[n] == ',')
809 cp[n] = '\n';
810 } else if (strcmp(optarg, "help") == 0) {
811 cp = xstrdup(
812 "cipher\ncipher-auth\ncompression\nkex\n"
813 "key\nkey-cert\nkey-plain\nkey-sig\nmac\n"
814 "protocol-version\nsig");
815 }
816 if (cp == NULL)
817 fatal("Unsupported query \"%s\"", optarg);
818 printf("%s\n", cp);
819 free(cp);
820 exit(0);
821 break;
822 case 'a':
823 options.forward_agent = 0;
824 break;
825 case 'A':
826 options.forward_agent = 1;
827 break;
828 case 'k':
829 options.gss_deleg_creds = 0;
830 break;
831 case 'K':
832 options.gss_authentication = 1;
833 options.gss_deleg_creds = 1;
834 break;
835 case 'i':
836 p = tilde_expand_filename(optarg, getuid());
837 if (stat(p, &st) == -1)
838 fprintf(stderr, "Warning: Identity file %s "
839 "not accessible: %s.\n", p,
840 strerror(errno));
841 else
842 add_identity_file(&options, NULL, p, 1);
843 free(p);
844 break;
845 case 'I':
846 #ifdef ENABLE_PKCS11
847 free(options.pkcs11_provider);
848 options.pkcs11_provider = xstrdup(optarg);
849 #else
850 fprintf(stderr, "no support for PKCS#11.\n");
851 #endif
852 break;
853 case 'J':
854 if (options.jump_host != NULL) {
855 fatal("Only a single -J option is permitted "
856 "(use commas to separate multiple "
857 "jump hops)");
858 }
859 if (options.proxy_command != NULL)
860 fatal("Cannot specify -J with ProxyCommand");
861 if (parse_jump(optarg, &options, 1) == -1)
862 fatal("Invalid -J argument");
863 options.proxy_command = xstrdup("none");
864 break;
865 case 't':
866 if (options.request_tty == REQUEST_TTY_YES)
867 options.request_tty = REQUEST_TTY_FORCE;
868 else
869 options.request_tty = REQUEST_TTY_YES;
870 break;
871 case 'v':
872 if (debug_flag == 0) {
873 debug_flag = 1;
874 options.log_level = SYSLOG_LEVEL_DEBUG1;
875 } else {
876 if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
877 debug_flag++;
878 options.log_level++;
879 }
880 }
881 break;
882 case 'V':
883 fprintf(stderr, "%s, %s\n",
884 SSH_RELEASE, SSH_OPENSSL_VERSION);
885 if (opt == 'V')
886 exit(0);
887 break;
888 case 'w':
889 if (options.tun_open == -1)
890 options.tun_open = SSH_TUNMODE_DEFAULT;
891 options.tun_local = a2tun(optarg, &options.tun_remote);
892 if (options.tun_local == SSH_TUNID_ERR) {
893 fprintf(stderr,
894 "Bad tun device '%s'\n", optarg);
895 exit(255);
896 }
897 break;
898 case 'W':
899 if (options.stdio_forward_host != NULL)
900 fatal("stdio forward already specified");
901 if (muxclient_command != 0)
902 fatal("Cannot specify stdio forward with -O");
903 if (parse_forward(&fwd, optarg, 1, 0)) {
904 options.stdio_forward_host = fwd.listen_host;
905 options.stdio_forward_port = fwd.listen_port;
906 free(fwd.connect_host);
907 } else {
908 fprintf(stderr,
909 "Bad stdio forwarding specification '%s'\n",
910 optarg);
911 exit(255);
912 }
913 options.request_tty = REQUEST_TTY_NO;
914 options.session_type = SESSION_TYPE_NONE;
915 break;
916 case 'q':
917 options.log_level = SYSLOG_LEVEL_QUIET;
918 break;
919 case 'e':
920 if (optarg[0] == '^' && optarg[2] == 0 &&
921 (u_char) optarg[1] >= 64 &&
922 (u_char) optarg[1] < 128)
923 options.escape_char = (u_char) optarg[1] & 31;
924 else if (strlen(optarg) == 1)
925 options.escape_char = (u_char) optarg[0];
926 else if (strcmp(optarg, "none") == 0)
927 options.escape_char = SSH_ESCAPECHAR_NONE;
928 else {
929 fprintf(stderr, "Bad escape character '%s'.\n",
930 optarg);
931 exit(255);
932 }
933 break;
934 case 'c':
935 if (!ciphers_valid(*optarg == '+' || *optarg == '^' ?
936 optarg + 1 : optarg)) {
937 fprintf(stderr, "Unknown cipher type '%s'\n",
938 optarg);
939 exit(255);
940 }
941 free(options.ciphers);
942 options.ciphers = xstrdup(optarg);
943 break;
944 case 'm':
945 if (mac_valid(optarg)) {
946 free(options.macs);
947 options.macs = xstrdup(optarg);
948 } else {
949 fprintf(stderr, "Unknown mac type '%s'\n",
950 optarg);
951 exit(255);
952 }
953 break;
954 case 'M':
955 if (options.control_master == SSHCTL_MASTER_YES)
956 options.control_master = SSHCTL_MASTER_ASK;
957 else
958 options.control_master = SSHCTL_MASTER_YES;
959 break;
960 case 'p':
961 if (options.port == -1) {
962 options.port = a2port(optarg);
963 if (options.port <= 0) {
964 fprintf(stderr, "Bad port '%s'\n",
965 optarg);
966 exit(255);
967 }
968 }
969 break;
970 case 'l':
971 if (options.user == NULL)
972 options.user = optarg;
973 break;
974
975 case 'L':
976 if (parse_forward(&fwd, optarg, 0, 0))
977 add_local_forward(&options, &fwd);
978 else {
979 fprintf(stderr,
980 "Bad local forwarding specification '%s'\n",
981 optarg);
982 exit(255);
983 }
984 break;
985
986 case 'R':
987 if (parse_forward(&fwd, optarg, 0, 1) ||
988 parse_forward(&fwd, optarg, 1, 1)) {
989 add_remote_forward(&options, &fwd);
990 } else {
991 fprintf(stderr,
992 "Bad remote forwarding specification "
993 "'%s'\n", optarg);
994 exit(255);
995 }
996 break;
997
998 case 'D':
999 if (parse_forward(&fwd, optarg, 1, 0)) {
1000 add_local_forward(&options, &fwd);
1001 } else {
1002 fprintf(stderr,
1003 "Bad dynamic forwarding specification "
1004 "'%s'\n", optarg);
1005 exit(255);
1006 }
1007 break;
1008
1009 case 'C':
1010 #ifdef WITH_ZLIB
1011 options.compression = 1;
1012 #else
1013 error("Compression not supported, disabling.");
1014 #endif
1015 break;
1016 case 'N':
1017 if (options.session_type != -1 &&
1018 options.session_type != SESSION_TYPE_NONE)
1019 fatal("Cannot specify -N with -s/SessionType");
1020 options.session_type = SESSION_TYPE_NONE;
1021 options.request_tty = REQUEST_TTY_NO;
1022 break;
1023 case 'T':
1024 options.request_tty = REQUEST_TTY_NO;
1025 break;
1026 case 'o':
1027 line = xstrdup(optarg);
1028 if (process_config_line(&options, pw,
1029 host ? host : "", host ? host : "", line,
1030 "command-line", 0, NULL, SSHCONF_USERCONF) != 0)
1031 exit(255);
1032 free(line);
1033 break;
1034 case 's':
1035 if (options.session_type != -1 &&
1036 options.session_type != SESSION_TYPE_SUBSYSTEM)
1037 fatal("Cannot specify -s with -N/SessionType");
1038 options.session_type = SESSION_TYPE_SUBSYSTEM;
1039 break;
1040 case 'S':
1041 free(options.control_path);
1042 options.control_path = xstrdup(optarg);
1043 break;
1044 case 'b':
1045 options.bind_address = optarg;
1046 break;
1047 case 'B':
1048 options.bind_interface = optarg;
1049 break;
1050 case 'F':
1051 config = optarg;
1052 break;
1053 default:
1054 usage();
1055 }
1056 }
1057
1058 if (optind > 1 && strcmp(av[optind - 1], "--") == 0)
1059 opt_terminated = 1;
1060
1061 ac -= optind;
1062 av += optind;
1063
1064 if (ac > 0 && !host) {
1065 int tport;
1066 char *tuser;
1067 switch (parse_ssh_uri(*av, &tuser, &host, &tport)) {
1068 case -1:
1069 usage();
1070 break;
1071 case 0:
1072 if (options.user == NULL) {
1073 options.user = tuser;
1074 tuser = NULL;
1075 }
1076 free(tuser);
1077 if (options.port == -1 && tport != -1)
1078 options.port = tport;
1079 break;
1080 default:
1081 p = xstrdup(*av);
1082 cp = strrchr(p, '@');
1083 if (cp != NULL) {
1084 if (cp == p)
1085 usage();
1086 if (options.user == NULL) {
1087 options.user = p;
1088 p = NULL;
1089 }
1090 *cp++ = '\0';
1091 host = xstrdup(cp);
1092 free(p);
1093 } else
1094 host = p;
1095 break;
1096 }
1097 if (ac > 1 && !opt_terminated) {
1098 optind = optreset = 1;
1099 goto again;
1100 }
1101 ac--, av++;
1102 }
1103
1104 /* Check that we got a host name. */
1105 if (!host)
1106 usage();
1107
1108 host_arg = xstrdup(host);
1109
1110 /* Initialize the command to execute on remote host. */
1111 if ((command = sshbuf_new()) == NULL)
1112 fatal("sshbuf_new failed");
1113
1114 /*
1115 * Save the command to execute on the remote host in a buffer. There
1116 * is no limit on the length of the command, except by the maximum
1117 * packet size. Also sets the tty flag if there is no command.
1118 */
1119 if (!ac) {
1120 /* No command specified - execute shell on a tty. */
1121 if (options.session_type == SESSION_TYPE_SUBSYSTEM) {
1122 fprintf(stderr,
1123 "You must specify a subsystem to invoke.\n");
1124 usage();
1125 }
1126 } else {
1127 /* A command has been specified. Store it into the buffer. */
1128 for (i = 0; i < ac; i++) {
1129 if ((r = sshbuf_putf(command, "%s%s",
1130 i ? " " : "", av[i])) != 0)
1131 fatal_fr(r, "buffer error");
1132 }
1133 }
1134
1135 ssh_signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
1136
1137 /*
1138 * Initialize "log" output. Since we are the client all output
1139 * goes to stderr unless otherwise specified by -y or -E.
1140 */
1141 if (use_syslog && logfile != NULL)
1142 fatal("Can't specify both -y and -E");
1143 if (logfile != NULL)
1144 log_redirect_stderr_to(logfile);
1145 log_init(argv0,
1146 options.log_level == SYSLOG_LEVEL_NOT_SET ?
1147 SYSLOG_LEVEL_INFO : options.log_level,
1148 options.log_facility == SYSLOG_FACILITY_NOT_SET ?
1149 SYSLOG_FACILITY_USER : options.log_facility,
1150 !use_syslog);
1151
1152 if (debug_flag)
1153 logit("%s, %s", SSH_RELEASE, SSH_OPENSSL_VERSION);
1154
1155 /* Parse the configuration files */
1156 process_config_files(host_arg, pw, 0, &want_final_pass);
1157 if (want_final_pass)
1158 debug("configuration requests final Match pass");
1159
1160 /* Hostname canonicalisation needs a few options filled. */
1161 fill_default_options_for_canonicalization(&options);
1162
1163 /* If the user has replaced the hostname then take it into use now */
1164 if (options.hostname != NULL) {
1165 /* NB. Please keep in sync with readconf.c:match_cfg_line() */
1166 cp = percent_expand(options.hostname,
1167 "h", host, (char *)NULL);
1168 free(host);
1169 host = cp;
1170 free(options.hostname);
1171 options.hostname = xstrdup(host);
1172 }
1173
1174 /* Don't lowercase addresses, they will be explicitly canonicalised */
1175 if ((was_addr = is_addr(host)) == 0)
1176 lowercase(host);
1177
1178 /*
1179 * Try to canonicalize if requested by configuration or the
1180 * hostname is an address.
1181 */
1182 if (options.canonicalize_hostname != SSH_CANONICALISE_NO || was_addr)
1183 addrs = resolve_canonicalize(&host, options.port);
1184
1185 /*
1186 * If CanonicalizePermittedCNAMEs have been specified but
1187 * other canonicalization did not happen (by not being requested
1188 * or by failing with fallback) then the hostname may still be changed
1189 * as a result of CNAME following.
1190 *
1191 * Try to resolve the bare hostname name using the system resolver's
1192 * usual search rules and then apply the CNAME follow rules.
1193 *
1194 * Skip the lookup if a ProxyCommand is being used unless the user
1195 * has specifically requested canonicalisation for this case via
1196 * CanonicalizeHostname=always
1197 */
1198 direct = option_clear_or_none(options.proxy_command) &&
1199 options.jump_host == NULL;
1200 if (addrs == NULL && config_has_permitted_cnames(&options) && (direct ||
1201 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) {
1202 if ((addrs = resolve_host(host, options.port,
1203 direct, cname, sizeof(cname))) == NULL) {
1204 /* Don't fatal proxied host names not in the DNS */
1205 if (direct)
1206 cleanup_exit(255); /* logged in resolve_host */
1207 } else
1208 check_follow_cname(direct, &host, cname);
1209 }
1210
1211 /*
1212 * If canonicalisation is enabled then re-parse the configuration
1213 * files as new stanzas may match.
1214 */
1215 if (options.canonicalize_hostname != 0 && !want_final_pass) {
1216 debug("hostname canonicalisation enabled, "
1217 "will re-parse configuration");
1218 want_final_pass = 1;
1219 }
1220
1221 if (want_final_pass) {
1222 debug("re-parsing configuration");
1223 free(options.hostname);
1224 options.hostname = xstrdup(host);
1225 process_config_files(host_arg, pw, 1, NULL);
1226 /*
1227 * Address resolution happens early with canonicalisation
1228 * enabled and the port number may have changed since, so
1229 * reset it in address list
1230 */
1231 if (addrs != NULL && options.port > 0)
1232 set_addrinfo_port(addrs, options.port);
1233 }
1234
1235 /* Fill configuration defaults. */
1236 if (fill_default_options(&options) != 0)
1237 cleanup_exit(255);
1238
1239 if (options.user == NULL)
1240 options.user = xstrdup(pw->pw_name);
1241
1242 /*
1243 * If ProxyJump option specified, then construct a ProxyCommand now.
1244 */
1245 if (options.jump_host != NULL) {
1246 char port_s[8];
1247 const char *jumpuser = options.jump_user, *sshbin = argv0;
1248 int port = options.port, jumpport = options.jump_port;
1249
1250 if (port <= 0)
1251 port = default_ssh_port();
1252 if (jumpport <= 0)
1253 jumpport = default_ssh_port();
1254 if (jumpuser == NULL)
1255 jumpuser = options.user;
1256 if (strcmp(options.jump_host, host) == 0 && port == jumpport &&
1257 strcmp(options.user, jumpuser) == 0)
1258 fatal("jumphost loop via %s", options.jump_host);
1259
1260 /*
1261 * Try to use SSH indicated by argv[0], but fall back to
1262 * "ssh" if it appears unavailable.
1263 */
1264 if (strchr(argv0, '/') != NULL && access(argv0, X_OK) != 0)
1265 sshbin = "ssh";
1266
1267 /* Consistency check */
1268 if (options.proxy_command != NULL)
1269 fatal("inconsistent options: ProxyCommand+ProxyJump");
1270 /* Never use FD passing for ProxyJump */
1271 options.proxy_use_fdpass = 0;
1272 snprintf(port_s, sizeof(port_s), "%d", options.jump_port);
1273 xasprintf(&options.proxy_command,
1274 "%s%s%s%s%s%s%s%s%s%s%.*s -W '[%%h]:%%p' %s",
1275 sshbin,
1276 /* Optional "-l user" argument if jump_user set */
1277 options.jump_user == NULL ? "" : " -l ",
1278 options.jump_user == NULL ? "" : options.jump_user,
1279 /* Optional "-p port" argument if jump_port set */
1280 options.jump_port <= 0 ? "" : " -p ",
1281 options.jump_port <= 0 ? "" : port_s,
1282 /* Optional additional jump hosts ",..." */
1283 options.jump_extra == NULL ? "" : " -J ",
1284 options.jump_extra == NULL ? "" : options.jump_extra,
1285 /* Optional "-F" argument if -F specified */
1286 config == NULL ? "" : " -F ",
1287 config == NULL ? "" : config,
1288 /* Optional "-v" arguments if -v set */
1289 debug_flag ? " -" : "",
1290 debug_flag, "vvv",
1291 /* Mandatory hostname */
1292 options.jump_host);
1293 debug("Setting implicit ProxyCommand from ProxyJump: %s",
1294 options.proxy_command);
1295 }
1296
1297 if (options.port == 0)
1298 options.port = default_ssh_port();
1299 channel_set_af(ssh, options.address_family);
1300
1301 /* Tidy and check options */
1302 if (options.host_key_alias != NULL)
1303 lowercase(options.host_key_alias);
1304 if (options.proxy_command != NULL &&
1305 strcmp(options.proxy_command, "-") == 0 &&
1306 options.proxy_use_fdpass)
1307 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible");
1308 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) {
1309 if (options.control_persist && options.control_path != NULL) {
1310 debug("UpdateHostKeys=ask is incompatible with "
1311 "ControlPersist; disabling");
1312 options.update_hostkeys = 0;
1313 } else if (sshbuf_len(command) != 0 ||
1314 options.remote_command != NULL ||
1315 options.request_tty == REQUEST_TTY_NO) {
1316 debug("UpdateHostKeys=ask is incompatible with "
1317 "remote command execution; disabling");
1318 options.update_hostkeys = 0;
1319 } else if (options.log_level < SYSLOG_LEVEL_INFO) {
1320 /* no point logging anything; user won't see it */
1321 options.update_hostkeys = 0;
1322 }
1323 }
1324 if (options.connection_attempts <= 0)
1325 fatal("Invalid number of ConnectionAttempts");
1326
1327 if (sshbuf_len(command) != 0 && options.remote_command != NULL)
1328 fatal("Cannot execute command-line and remote command.");
1329
1330 /* Cannot fork to background if no command. */
1331 if (options.fork_after_authentication && sshbuf_len(command) == 0 &&
1332 options.remote_command == NULL &&
1333 options.session_type != SESSION_TYPE_NONE)
1334 fatal("Cannot fork into background without a command "
1335 "to execute.");
1336
1337 /* reinit */
1338 log_init(argv0, options.log_level, options.log_facility, !use_syslog);
1339 for (j = 0; j < options.num_log_verbose; j++) {
1340 if (strcasecmp(options.log_verbose[j], "none") == 0)
1341 break;
1342 log_verbose_add(options.log_verbose[j]);
1343 }
1344
1345 if (options.request_tty == REQUEST_TTY_YES ||
1346 options.request_tty == REQUEST_TTY_FORCE)
1347 tty_flag = 1;
1348
1349 /* Allocate a tty by default if no command specified. */
1350 if (sshbuf_len(command) == 0 && options.remote_command == NULL)
1351 tty_flag = options.request_tty != REQUEST_TTY_NO;
1352
1353 /* Force no tty */
1354 if (options.request_tty == REQUEST_TTY_NO ||
1355 (muxclient_command && muxclient_command != SSHMUX_COMMAND_PROXY) ||
1356 options.session_type == SESSION_TYPE_NONE)
1357 tty_flag = 0;
1358 /* Do not allocate a tty if stdin is not a tty. */
1359 if ((!isatty(fileno(stdin)) || options.stdin_null) &&
1360 options.request_tty != REQUEST_TTY_FORCE) {
1361 if (tty_flag)
1362 logit("Pseudo-terminal will not be allocated because "
1363 "stdin is not a terminal.");
1364 tty_flag = 0;
1365 }
1366
1367 /* Set up strings used to percent_expand() arguments */
1368 cinfo = xcalloc(1, sizeof(*cinfo));
1369 if (gethostname(thishost, sizeof(thishost)) == -1)
1370 fatal("gethostname: %s", strerror(errno));
1371 cinfo->thishost = xstrdup(thishost);
1372 thishost[strcspn(thishost, ".")] = '\0';
1373 cinfo->shorthost = xstrdup(thishost);
1374 xasprintf(&cinfo->portstr, "%d", options.port);
1375 xasprintf(&cinfo->uidstr, "%llu",
1376 (unsigned long long)pw->pw_uid);
1377 cinfo->keyalias = xstrdup(options.host_key_alias ?
1378 options.host_key_alias : host_arg);
1379 cinfo->conn_hash_hex = ssh_connection_hash(cinfo->thishost, host,
1380 cinfo->portstr, options.user);
1381 cinfo->host_arg = xstrdup(host_arg);
1382 cinfo->remhost = xstrdup(host);
1383 cinfo->remuser = xstrdup(options.user);
1384 cinfo->homedir = xstrdup(pw->pw_dir);
1385 cinfo->locuser = xstrdup(pw->pw_name);
1386
1387 /*
1388 * Expand tokens in arguments. NB. LocalCommand is expanded later,
1389 * after port-forwarding is set up, so it may pick up any local
1390 * tunnel interface name allocated.
1391 */
1392 if (options.remote_command != NULL) {
1393 debug3("expanding RemoteCommand: %s", options.remote_command);
1394 cp = options.remote_command;
1395 options.remote_command = default_client_percent_expand(cp,
1396 cinfo);
1397 debug3("expanded RemoteCommand: %s", options.remote_command);
1398 free(cp);
1399 if ((r = sshbuf_put(command, options.remote_command,
1400 strlen(options.remote_command))) != 0)
1401 fatal_fr(r, "buffer error");
1402 }
1403
1404 if (options.control_path != NULL) {
1405 cp = tilde_expand_filename(options.control_path, getuid());
1406 free(options.control_path);
1407 options.control_path = default_client_percent_dollar_expand(cp,
1408 cinfo);
1409 free(cp);
1410 }
1411
1412 if (options.identity_agent != NULL) {
1413 p = tilde_expand_filename(options.identity_agent, getuid());
1414 cp = default_client_percent_dollar_expand(p, cinfo);
1415 free(p);
1416 free(options.identity_agent);
1417 options.identity_agent = cp;
1418 }
1419
1420 if (options.forward_agent_sock_path != NULL) {
1421 p = tilde_expand_filename(options.forward_agent_sock_path,
1422 getuid());
1423 cp = default_client_percent_dollar_expand(p, cinfo);
1424 free(p);
1425 free(options.forward_agent_sock_path);
1426 options.forward_agent_sock_path = cp;
1427 if (stat(options.forward_agent_sock_path, &st) != 0) {
1428 error("Cannot forward agent socket path \"%s\": %s",
1429 options.forward_agent_sock_path, strerror(errno));
1430 if (options.exit_on_forward_failure)
1431 cleanup_exit(255);
1432 }
1433 }
1434
1435 if (options.num_system_hostfiles > 0 &&
1436 strcasecmp(options.system_hostfiles[0], "none") == 0) {
1437 if (options.num_system_hostfiles > 1)
1438 fatal("Invalid GlobalKnownHostsFiles: \"none\" "
1439 "appears with other entries");
1440 free(options.system_hostfiles[0]);
1441 options.system_hostfiles[0] = NULL;
1442 options.num_system_hostfiles = 0;
1443 }
1444
1445 if (options.num_user_hostfiles > 0 &&
1446 strcasecmp(options.user_hostfiles[0], "none") == 0) {
1447 if (options.num_user_hostfiles > 1)
1448 fatal("Invalid UserKnownHostsFiles: \"none\" "
1449 "appears with other entries");
1450 free(options.user_hostfiles[0]);
1451 options.user_hostfiles[0] = NULL;
1452 options.num_user_hostfiles = 0;
1453 }
1454 for (j = 0; j < options.num_user_hostfiles; j++) {
1455 if (options.user_hostfiles[j] == NULL)
1456 continue;
1457 cp = tilde_expand_filename(options.user_hostfiles[j], getuid());
1458 p = default_client_percent_dollar_expand(cp, cinfo);
1459 if (strcmp(options.user_hostfiles[j], p) != 0)
1460 debug3("expanded UserKnownHostsFile '%s' -> "
1461 "'%s'", options.user_hostfiles[j], p);
1462 free(options.user_hostfiles[j]);
1463 free(cp);
1464 options.user_hostfiles[j] = p;
1465 }
1466
1467 for (i = 0; i < options.num_local_forwards; i++) {
1468 if (options.local_forwards[i].listen_path != NULL) {
1469 cp = options.local_forwards[i].listen_path;
1470 p = options.local_forwards[i].listen_path =
1471 default_client_percent_expand(cp, cinfo);
1472 if (strcmp(cp, p) != 0)
1473 debug3("expanded LocalForward listen path "
1474 "'%s' -> '%s'", cp, p);
1475 free(cp);
1476 }
1477 if (options.local_forwards[i].connect_path != NULL) {
1478 cp = options.local_forwards[i].connect_path;
1479 p = options.local_forwards[i].connect_path =
1480 default_client_percent_expand(cp, cinfo);
1481 if (strcmp(cp, p) != 0)
1482 debug3("expanded LocalForward connect path "
1483 "'%s' -> '%s'", cp, p);
1484 free(cp);
1485 }
1486 }
1487
1488 for (i = 0; i < options.num_remote_forwards; i++) {
1489 if (options.remote_forwards[i].listen_path != NULL) {
1490 cp = options.remote_forwards[i].listen_path;
1491 p = options.remote_forwards[i].listen_path =
1492 default_client_percent_expand(cp, cinfo);
1493 if (strcmp(cp, p) != 0)
1494 debug3("expanded RemoteForward listen path "
1495 "'%s' -> '%s'", cp, p);
1496 free(cp);
1497 }
1498 if (options.remote_forwards[i].connect_path != NULL) {
1499 cp = options.remote_forwards[i].connect_path;
1500 p = options.remote_forwards[i].connect_path =
1501 default_client_percent_expand(cp, cinfo);
1502 if (strcmp(cp, p) != 0)
1503 debug3("expanded RemoteForward connect path "
1504 "'%s' -> '%s'", cp, p);
1505 free(cp);
1506 }
1507 }
1508
1509 if (config_test) {
1510 dump_client_config(&options, host);
1511 exit(0);
1512 }
1513
1514 /* Expand SecurityKeyProvider if it refers to an environment variable */
1515 if (options.sk_provider != NULL && *options.sk_provider == '$' &&
1516 strlen(options.sk_provider) > 1) {
1517 if ((cp = getenv(options.sk_provider + 1)) == NULL) {
1518 debug("Authenticator provider %s did not resolve; "
1519 "disabling", options.sk_provider);
1520 free(options.sk_provider);
1521 options.sk_provider = NULL;
1522 } else {
1523 debug2("resolved SecurityKeyProvider %s => %s",
1524 options.sk_provider, cp);
1525 free(options.sk_provider);
1526 options.sk_provider = xstrdup(cp);
1527 }
1528 }
1529
1530 if (muxclient_command != 0 && options.control_path == NULL)
1531 fatal("No ControlPath specified for \"-O\" command");
1532 if (options.control_path != NULL) {
1533 int sock;
1534 if ((sock = muxclient(options.control_path)) >= 0) {
1535 ssh_packet_set_connection(ssh, sock, sock);
1536 ssh_packet_set_mux(ssh);
1537 goto skip_connect;
1538 }
1539 }
1540
1541 /*
1542 * If hostname canonicalisation was not enabled, then we may not
1543 * have yet resolved the hostname. Do so now.
1544 */
1545 if (addrs == NULL && options.proxy_command == NULL) {
1546 debug2("resolving \"%s\" port %d", host, options.port);
1547 if ((addrs = resolve_host(host, options.port, 1,
1548 cname, sizeof(cname))) == NULL)
1549 cleanup_exit(255); /* resolve_host logs the error */
1550 }
1551
1552 if (options.connection_timeout >= INT_MAX/1000)
1553 timeout_ms = INT_MAX;
1554 else
1555 timeout_ms = options.connection_timeout * 1000;
1556
1557 /* Open a connection to the remote host. */
1558 if (ssh_connect(ssh, host, host_arg, addrs, &hostaddr, options.port,
1559 options.connection_attempts,
1560 &timeout_ms, options.tcp_keep_alive) != 0)
1561 exit(255);
1562
1563 if (addrs != NULL)
1564 freeaddrinfo(addrs);
1565
1566 ssh_packet_set_timeout(ssh, options.server_alive_interval,
1567 options.server_alive_count_max);
1568
1569 if (timeout_ms > 0)
1570 debug3("timeout: %d ms remain after connect", timeout_ms);
1571
1572 /*
1573 * If we successfully made the connection and we have hostbased auth
1574 * enabled, load the public keys so we can later use the ssh-keysign
1575 * helper to sign challenges.
1576 */
1577 sensitive_data.nkeys = 0;
1578 sensitive_data.keys = NULL;
1579 if (options.hostbased_authentication) {
1580 sensitive_data.nkeys = 10;
1581 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
1582 sizeof(struct sshkey));
1583
1584 /* XXX check errors? */
1585 #define L_PUBKEY(p,o) do { \
1586 if ((o) >= sensitive_data.nkeys) \
1587 fatal_f("pubkey out of array bounds"); \
1588 check_load(sshkey_load_public(p, &(sensitive_data.keys[o]), NULL), \
1589 &(sensitive_data.keys[o]), p, "pubkey"); \
1590 if (sensitive_data.keys[o] != NULL) \
1591 debug2("hostbased key %d: %s key from \"%s\"", o, \
1592 sshkey_ssh_name(sensitive_data.keys[o]), p); \
1593 } while (0)
1594 #define L_CERT(p,o) do { \
1595 if ((o) >= sensitive_data.nkeys) \
1596 fatal_f("cert out of array bounds"); \
1597 check_load(sshkey_load_cert(p, &(sensitive_data.keys[o])), \
1598 &(sensitive_data.keys[o]), p, "cert"); \
1599 if (sensitive_data.keys[o] != NULL) \
1600 debug2("hostbased key %d: %s cert from \"%s\"", o, \
1601 sshkey_ssh_name(sensitive_data.keys[o]), p); \
1602 } while (0)
1603
1604 if (options.hostbased_authentication == 1) {
1605 L_CERT(_PATH_HOST_ECDSA_KEY_FILE, 0);
1606 L_CERT(_PATH_HOST_ED25519_KEY_FILE, 1);
1607 L_CERT(_PATH_HOST_RSA_KEY_FILE, 2);
1608 L_CERT(_PATH_HOST_DSA_KEY_FILE, 3);
1609 L_PUBKEY(_PATH_HOST_ECDSA_KEY_FILE, 4);
1610 L_PUBKEY(_PATH_HOST_ED25519_KEY_FILE, 5);
1611 L_PUBKEY(_PATH_HOST_RSA_KEY_FILE, 6);
1612 L_PUBKEY(_PATH_HOST_DSA_KEY_FILE, 7);
1613 L_CERT(_PATH_HOST_XMSS_KEY_FILE, 8);
1614 L_PUBKEY(_PATH_HOST_XMSS_KEY_FILE, 9);
1615 }
1616 }
1617
1618 /* load options.identity_files */
1619 load_public_identity_files(cinfo);
1620
1621 /* optionally set the SSH_AUTHSOCKET_ENV_NAME variable */
1622 if (options.identity_agent &&
1623 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) {
1624 if (strcmp(options.identity_agent, "none") == 0) {
1625 unsetenv(SSH_AUTHSOCKET_ENV_NAME);
1626 } else {
1627 cp = options.identity_agent;
1628 /* legacy (limited) format */
1629 if (cp[0] == '$' && cp[1] != '{') {
1630 if (!valid_env_name(cp + 1)) {
1631 fatal("Invalid IdentityAgent "
1632 "environment variable name %s", cp);
1633 }
1634 if ((p = getenv(cp + 1)) == NULL)
1635 unsetenv(SSH_AUTHSOCKET_ENV_NAME);
1636 else
1637 setenv(SSH_AUTHSOCKET_ENV_NAME, p, 1);
1638 } else {
1639 /* identity_agent specifies a path directly */
1640 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1);
1641 }
1642 }
1643 }
1644
1645 if (options.forward_agent && options.forward_agent_sock_path != NULL) {
1646 cp = options.forward_agent_sock_path;
1647 if (cp[0] == '$') {
1648 if (!valid_env_name(cp + 1)) {
1649 fatal("Invalid ForwardAgent environment variable name %s", cp);
1650 }
1651 if ((p = getenv(cp + 1)) != NULL)
1652 forward_agent_sock_path = xstrdup(p);
1653 else
1654 options.forward_agent = 0;
1655 free(cp);
1656 } else {
1657 forward_agent_sock_path = cp;
1658 }
1659 }
1660
1661 /* Expand ~ in known host file names. */
1662 tilde_expand_paths(options.system_hostfiles,
1663 options.num_system_hostfiles);
1664 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles);
1665
1666 ssh_signal(SIGCHLD, main_sigchld_handler);
1667
1668 /* Log into the remote system. Never returns if the login fails. */
1669 ssh_login(ssh, &sensitive_data, host, (struct sockaddr *)&hostaddr,
1670 options.port, pw, timeout_ms, cinfo);
1671
1672 /* We no longer need the private host keys. Clear them now. */
1673 if (sensitive_data.nkeys != 0) {
1674 for (i = 0; i < sensitive_data.nkeys; i++) {
1675 if (sensitive_data.keys[i] != NULL) {
1676 /* Destroys contents safely */
1677 debug3("clear hostkey %d", i);
1678 sshkey_free(sensitive_data.keys[i]);
1679 sensitive_data.keys[i] = NULL;
1680 }
1681 }
1682 free(sensitive_data.keys);
1683 }
1684 for (i = 0; i < options.num_identity_files; i++) {
1685 free(options.identity_files[i]);
1686 options.identity_files[i] = NULL;
1687 if (options.identity_keys[i]) {
1688 sshkey_free(options.identity_keys[i]);
1689 options.identity_keys[i] = NULL;
1690 }
1691 }
1692 for (i = 0; i < options.num_certificate_files; i++) {
1693 free(options.certificate_files[i]);
1694 options.certificate_files[i] = NULL;
1695 }
1696
1697 #ifdef ENABLE_PKCS11
1698 (void)pkcs11_del_provider(options.pkcs11_provider);
1699 #endif
1700
1701 skip_connect:
1702 exit_status = ssh_session2(ssh, cinfo);
1703 ssh_conn_info_free(cinfo);
1704 ssh_packet_close(ssh);
1705
1706 if (options.control_path != NULL && muxserver_sock != -1)
1707 unlink(options.control_path);
1708
1709 /* Kill ProxyCommand if it is running. */
1710 ssh_kill_proxy_command();
1711
1712 return exit_status;
1713 }
1714
1715 static void
control_persist_detach(void)1716 control_persist_detach(void)
1717 {
1718 pid_t pid;
1719
1720 debug_f("backgrounding master process");
1721
1722 /*
1723 * master (current process) into the background, and make the
1724 * foreground process a client of the backgrounded master.
1725 */
1726 switch ((pid = fork())) {
1727 case -1:
1728 fatal_f("fork: %s", strerror(errno));
1729 case 0:
1730 /* Child: master process continues mainloop */
1731 break;
1732 default:
1733 /* Parent: set up mux client to connect to backgrounded master */
1734 debug2_f("background process is %ld", (long)pid);
1735 options.stdin_null = ostdin_null_flag;
1736 options.request_tty = orequest_tty;
1737 tty_flag = otty_flag;
1738 options.session_type = osession_type;
1739 close(muxserver_sock);
1740 muxserver_sock = -1;
1741 options.control_master = SSHCTL_MASTER_NO;
1742 muxclient(options.control_path);
1743 /* muxclient() doesn't return on success. */
1744 fatal("Failed to connect to new control master");
1745 }
1746 if (stdfd_devnull(1, 1, !(log_is_on_stderr() && debug_flag)) == -1)
1747 error_f("stdfd_devnull failed");
1748 daemon(1, 1);
1749 setproctitle("%s [mux]", options.control_path);
1750 }
1751
1752 /* Do fork() after authentication. Used by "ssh -f" */
1753 static void
fork_postauth(void)1754 fork_postauth(void)
1755 {
1756 if (need_controlpersist_detach)
1757 control_persist_detach();
1758 debug("forking to background");
1759 options.fork_after_authentication = 0;
1760 if (daemon(1, 1) == -1)
1761 fatal("daemon() failed: %.200s", strerror(errno));
1762 if (stdfd_devnull(1, 1, !(log_is_on_stderr() && debug_flag)) == -1)
1763 error_f("stdfd_devnull failed");
1764 }
1765
1766 static void
forwarding_success(void)1767 forwarding_success(void)
1768 {
1769 if (forward_confirms_pending == -1)
1770 return;
1771 if (--forward_confirms_pending == 0) {
1772 debug_f("all expected forwarding replies received");
1773 if (options.fork_after_authentication)
1774 fork_postauth();
1775 } else {
1776 debug2_f("%d expected forwarding replies remaining",
1777 forward_confirms_pending);
1778 }
1779 }
1780
1781 /* Callback for remote forward global requests */
1782 static void
ssh_confirm_remote_forward(struct ssh * ssh,int type,u_int32_t seq,void * ctxt)1783 ssh_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt)
1784 {
1785 struct Forward *rfwd = (struct Forward *)ctxt;
1786 u_int port;
1787 int r;
1788
1789 /* XXX verbose() on failure? */
1790 debug("remote forward %s for: listen %s%s%d, connect %s:%d",
1791 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1792 rfwd->listen_path ? rfwd->listen_path :
1793 rfwd->listen_host ? rfwd->listen_host : "",
1794 (rfwd->listen_path || rfwd->listen_host) ? ":" : "",
1795 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path :
1796 rfwd->connect_host, rfwd->connect_port);
1797 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) {
1798 if (type == SSH2_MSG_REQUEST_SUCCESS) {
1799 if ((r = sshpkt_get_u32(ssh, &port)) != 0)
1800 fatal_fr(r, "parse packet");
1801 if (port > 65535) {
1802 error("Invalid allocated port %u for remote "
1803 "forward to %s:%d", port,
1804 rfwd->connect_host, rfwd->connect_port);
1805 /* Ensure failure processing runs below */
1806 type = SSH2_MSG_REQUEST_FAILURE;
1807 channel_update_permission(ssh,
1808 rfwd->handle, -1);
1809 } else {
1810 rfwd->allocated_port = (int)port;
1811 logit("Allocated port %u for remote "
1812 "forward to %s:%d",
1813 rfwd->allocated_port, rfwd->connect_path ?
1814 rfwd->connect_path : rfwd->connect_host,
1815 rfwd->connect_port);
1816 channel_update_permission(ssh,
1817 rfwd->handle, rfwd->allocated_port);
1818 }
1819 } else {
1820 channel_update_permission(ssh, rfwd->handle, -1);
1821 }
1822 }
1823
1824 if (type == SSH2_MSG_REQUEST_FAILURE) {
1825 if (options.exit_on_forward_failure) {
1826 if (rfwd->listen_path != NULL)
1827 fatal("Error: remote port forwarding failed "
1828 "for listen path %s", rfwd->listen_path);
1829 else
1830 fatal("Error: remote port forwarding failed "
1831 "for listen port %d", rfwd->listen_port);
1832 } else {
1833 if (rfwd->listen_path != NULL)
1834 logit("Warning: remote port forwarding failed "
1835 "for listen path %s", rfwd->listen_path);
1836 else
1837 logit("Warning: remote port forwarding failed "
1838 "for listen port %d", rfwd->listen_port);
1839 }
1840 }
1841 forwarding_success();
1842 }
1843
1844 static void
client_cleanup_stdio_fwd(struct ssh * ssh,int id,void * arg)1845 client_cleanup_stdio_fwd(struct ssh *ssh, int id, void *arg)
1846 {
1847 debug("stdio forwarding: done");
1848 cleanup_exit(0);
1849 }
1850
1851 static void
ssh_stdio_confirm(struct ssh * ssh,int id,int success,void * arg)1852 ssh_stdio_confirm(struct ssh *ssh, int id, int success, void *arg)
1853 {
1854 if (!success)
1855 fatal("stdio forwarding failed");
1856 }
1857
1858 static void
ssh_tun_confirm(struct ssh * ssh,int id,int success,void * arg)1859 ssh_tun_confirm(struct ssh *ssh, int id, int success, void *arg)
1860 {
1861 if (!success) {
1862 error("Tunnel forwarding failed");
1863 if (options.exit_on_forward_failure)
1864 cleanup_exit(255);
1865 }
1866
1867 debug_f("tunnel forward established, id=%d", id);
1868 forwarding_success();
1869 }
1870
1871 static void
ssh_init_stdio_forwarding(struct ssh * ssh)1872 ssh_init_stdio_forwarding(struct ssh *ssh)
1873 {
1874 Channel *c;
1875 int in, out;
1876
1877 if (options.stdio_forward_host == NULL)
1878 return;
1879
1880 debug3_f("%s:%d", options.stdio_forward_host,
1881 options.stdio_forward_port);
1882
1883 if ((in = dup(STDIN_FILENO)) == -1 ||
1884 (out = dup(STDOUT_FILENO)) == -1)
1885 fatal_f("dup() in/out failed");
1886 if ((c = channel_connect_stdio_fwd(ssh, options.stdio_forward_host,
1887 options.stdio_forward_port, in, out,
1888 CHANNEL_NONBLOCK_STDIO)) == NULL)
1889 fatal_f("channel_connect_stdio_fwd failed");
1890 channel_register_cleanup(ssh, c->self, client_cleanup_stdio_fwd, 0);
1891 channel_register_open_confirm(ssh, c->self, ssh_stdio_confirm, NULL);
1892 }
1893
1894 static void
ssh_init_forward_permissions(struct ssh * ssh,const char * what,char ** opens,u_int num_opens)1895 ssh_init_forward_permissions(struct ssh *ssh, const char *what, char **opens,
1896 u_int num_opens)
1897 {
1898 u_int i;
1899 int port;
1900 char *addr, *arg, *oarg;
1901 int where = FORWARD_LOCAL;
1902
1903 channel_clear_permission(ssh, FORWARD_ADM, where);
1904 if (num_opens == 0)
1905 return; /* permit any */
1906
1907 /* handle keywords: "any" / "none" */
1908 if (num_opens == 1 && strcmp(opens[0], "any") == 0)
1909 return;
1910 if (num_opens == 1 && strcmp(opens[0], "none") == 0) {
1911 channel_disable_admin(ssh, where);
1912 return;
1913 }
1914 /* Otherwise treat it as a list of permitted host:port */
1915 for (i = 0; i < num_opens; i++) {
1916 oarg = arg = xstrdup(opens[i]);
1917 addr = hpdelim(&arg);
1918 if (addr == NULL)
1919 fatal_f("missing host in %s", what);
1920 addr = cleanhostname(addr);
1921 if (arg == NULL || ((port = permitopen_port(arg)) < 0))
1922 fatal_f("bad port number in %s", what);
1923 /* Send it to channels layer */
1924 channel_add_permission(ssh, FORWARD_ADM,
1925 where, addr, port);
1926 free(oarg);
1927 }
1928 }
1929
1930 static void
ssh_init_forwarding(struct ssh * ssh,char ** ifname)1931 ssh_init_forwarding(struct ssh *ssh, char **ifname)
1932 {
1933 int success = 0;
1934 int i;
1935
1936 ssh_init_forward_permissions(ssh, "permitremoteopen",
1937 options.permitted_remote_opens,
1938 options.num_permitted_remote_opens);
1939
1940 if (options.exit_on_forward_failure)
1941 forward_confirms_pending = 0; /* track pending requests */
1942 /* Initiate local TCP/IP port forwardings. */
1943 for (i = 0; i < options.num_local_forwards; i++) {
1944 debug("Local connections to %.200s:%d forwarded to remote "
1945 "address %.200s:%d",
1946 (options.local_forwards[i].listen_path != NULL) ?
1947 options.local_forwards[i].listen_path :
1948 (options.local_forwards[i].listen_host == NULL) ?
1949 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1950 options.local_forwards[i].listen_host,
1951 options.local_forwards[i].listen_port,
1952 (options.local_forwards[i].connect_path != NULL) ?
1953 options.local_forwards[i].connect_path :
1954 options.local_forwards[i].connect_host,
1955 options.local_forwards[i].connect_port);
1956 success += channel_setup_local_fwd_listener(ssh,
1957 &options.local_forwards[i], &options.fwd_opts);
1958 }
1959 if (i > 0 && success != i && options.exit_on_forward_failure)
1960 fatal("Could not request local forwarding.");
1961 if (i > 0 && success == 0)
1962 error("Could not request local forwarding.");
1963
1964 /* Initiate remote TCP/IP port forwardings. */
1965 for (i = 0; i < options.num_remote_forwards; i++) {
1966 debug("Remote connections from %.200s:%d forwarded to "
1967 "local address %.200s:%d",
1968 (options.remote_forwards[i].listen_path != NULL) ?
1969 options.remote_forwards[i].listen_path :
1970 (options.remote_forwards[i].listen_host == NULL) ?
1971 "LOCALHOST" : options.remote_forwards[i].listen_host,
1972 options.remote_forwards[i].listen_port,
1973 (options.remote_forwards[i].connect_path != NULL) ?
1974 options.remote_forwards[i].connect_path :
1975 options.remote_forwards[i].connect_host,
1976 options.remote_forwards[i].connect_port);
1977 if ((options.remote_forwards[i].handle =
1978 channel_request_remote_forwarding(ssh,
1979 &options.remote_forwards[i])) >= 0) {
1980 client_register_global_confirm(
1981 ssh_confirm_remote_forward,
1982 &options.remote_forwards[i]);
1983 forward_confirms_pending++;
1984 } else if (options.exit_on_forward_failure)
1985 fatal("Could not request remote forwarding.");
1986 else
1987 logit("Warning: Could not request remote forwarding.");
1988 }
1989
1990 /* Initiate tunnel forwarding. */
1991 if (options.tun_open != SSH_TUNMODE_NO) {
1992 if ((*ifname = client_request_tun_fwd(ssh,
1993 options.tun_open, options.tun_local,
1994 options.tun_remote, ssh_tun_confirm, NULL)) != NULL)
1995 forward_confirms_pending++;
1996 else if (options.exit_on_forward_failure)
1997 fatal("Could not request tunnel forwarding.");
1998 else
1999 error("Could not request tunnel forwarding.");
2000 }
2001 if (forward_confirms_pending > 0) {
2002 debug_f("expecting replies for %d forwards",
2003 forward_confirms_pending);
2004 }
2005 }
2006
2007 static void
check_agent_present(void)2008 check_agent_present(void)
2009 {
2010 int r;
2011
2012 if (options.forward_agent) {
2013 /* Clear agent forwarding if we don't have an agent. */
2014 if ((r = ssh_get_authentication_socket(NULL)) != 0) {
2015 options.forward_agent = 0;
2016 if (r != SSH_ERR_AGENT_NOT_PRESENT)
2017 debug_r(r, "ssh_get_authentication_socket");
2018 }
2019 }
2020 }
2021
2022 static void
ssh_session2_setup(struct ssh * ssh,int id,int success,void * arg)2023 ssh_session2_setup(struct ssh *ssh, int id, int success, void *arg)
2024 {
2025 extern char **environ;
2026 const char *display, *term;
2027 int r, interactive = tty_flag;
2028 char *proto = NULL, *data = NULL;
2029
2030 if (!success)
2031 return; /* No need for error message, channels code sens one */
2032
2033 display = getenv("DISPLAY");
2034 if (display == NULL && options.forward_x11)
2035 debug("X11 forwarding requested but DISPLAY not set");
2036 if (options.forward_x11 && client_x11_get_proto(ssh, display,
2037 options.xauth_location, options.forward_x11_trusted,
2038 options.forward_x11_timeout, &proto, &data) == 0) {
2039 /* Request forwarding with authentication spoofing. */
2040 debug("Requesting X11 forwarding with authentication "
2041 "spoofing.");
2042 x11_request_forwarding_with_spoofing(ssh, id, display, proto,
2043 data, 1);
2044 client_expect_confirm(ssh, id, "X11 forwarding", CONFIRM_WARN);
2045 /* XXX exit_on_forward_failure */
2046 interactive = 1;
2047 }
2048
2049 check_agent_present();
2050 if (options.forward_agent) {
2051 debug("Requesting authentication agent forwarding.");
2052 channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0);
2053 if ((r = sshpkt_send(ssh)) != 0)
2054 fatal_fr(r, "send packet");
2055 }
2056
2057 /* Tell the packet module whether this is an interactive session. */
2058 ssh_packet_set_interactive(ssh, interactive,
2059 options.ip_qos_interactive, options.ip_qos_bulk);
2060
2061 if ((term = lookup_env_in_list("TERM", options.setenv,
2062 options.num_setenv)) == NULL || *term == '\0')
2063 term = getenv("TERM");
2064 client_session2_setup(ssh, id, tty_flag,
2065 options.session_type == SESSION_TYPE_SUBSYSTEM, term,
2066 NULL, fileno(stdin), command, environ);
2067 }
2068
2069 /* open new channel for a session */
2070 static int
ssh_session2_open(struct ssh * ssh)2071 ssh_session2_open(struct ssh *ssh)
2072 {
2073 Channel *c;
2074 int window, packetmax, in, out, err;
2075
2076 if (options.stdin_null) {
2077 in = open(_PATH_DEVNULL, O_RDONLY);
2078 } else {
2079 in = dup(STDIN_FILENO);
2080 }
2081 out = dup(STDOUT_FILENO);
2082 err = dup(STDERR_FILENO);
2083
2084 if (in == -1 || out == -1 || err == -1)
2085 fatal("dup() in/out/err failed");
2086
2087 window = CHAN_SES_WINDOW_DEFAULT;
2088 packetmax = CHAN_SES_PACKET_DEFAULT;
2089 if (tty_flag) {
2090 window >>= 1;
2091 packetmax >>= 1;
2092 }
2093 c = channel_new(ssh,
2094 "session", SSH_CHANNEL_OPENING, in, out, err,
2095 window, packetmax, CHAN_EXTENDED_WRITE,
2096 "client-session", CHANNEL_NONBLOCK_STDIO);
2097
2098 debug3_f("channel_new: %d", c->self);
2099
2100 channel_send_open(ssh, c->self);
2101 if (options.session_type != SESSION_TYPE_NONE)
2102 channel_register_open_confirm(ssh, c->self,
2103 ssh_session2_setup, NULL);
2104
2105 return c->self;
2106 }
2107
2108 static int
ssh_session2(struct ssh * ssh,const struct ssh_conn_info * cinfo)2109 ssh_session2(struct ssh *ssh, const struct ssh_conn_info *cinfo)
2110 {
2111 int r, id = -1;
2112 char *cp, *tun_fwd_ifname = NULL;
2113
2114 /* XXX should be pre-session */
2115 if (!options.control_persist)
2116 ssh_init_stdio_forwarding(ssh);
2117
2118 ssh_init_forwarding(ssh, &tun_fwd_ifname);
2119
2120 if (options.local_command != NULL) {
2121 debug3("expanding LocalCommand: %s", options.local_command);
2122 cp = options.local_command;
2123 options.local_command = percent_expand(cp,
2124 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo),
2125 "T", tun_fwd_ifname == NULL ? "NONE" : tun_fwd_ifname,
2126 (char *)NULL);
2127 debug3("expanded LocalCommand: %s", options.local_command);
2128 free(cp);
2129 }
2130
2131 /* Start listening for multiplex clients */
2132 if (!ssh_packet_get_mux(ssh))
2133 muxserver_listen(ssh);
2134
2135 /*
2136 * If we are in control persist mode and have a working mux listen
2137 * socket, then prepare to background ourselves and have a foreground
2138 * client attach as a control client.
2139 * NB. we must save copies of the flags that we override for
2140 * the backgrounding, since we defer attachment of the client until
2141 * after the connection is fully established (in particular,
2142 * async rfwd replies have been received for ExitOnForwardFailure).
2143 */
2144 if (options.control_persist && muxserver_sock != -1) {
2145 ostdin_null_flag = options.stdin_null;
2146 osession_type = options.session_type;
2147 orequest_tty = options.request_tty;
2148 otty_flag = tty_flag;
2149 options.stdin_null = 1;
2150 options.session_type = SESSION_TYPE_NONE;
2151 tty_flag = 0;
2152 if (!options.fork_after_authentication &&
2153 (osession_type != SESSION_TYPE_NONE ||
2154 options.stdio_forward_host != NULL))
2155 need_controlpersist_detach = 1;
2156 options.fork_after_authentication = 1;
2157 }
2158 /*
2159 * ControlPersist mux listen socket setup failed, attempt the
2160 * stdio forward setup that we skipped earlier.
2161 */
2162 if (options.control_persist && muxserver_sock == -1)
2163 ssh_init_stdio_forwarding(ssh);
2164
2165 if (options.session_type != SESSION_TYPE_NONE)
2166 id = ssh_session2_open(ssh);
2167 else {
2168 ssh_packet_set_interactive(ssh,
2169 options.control_master == SSHCTL_MASTER_NO,
2170 options.ip_qos_interactive, options.ip_qos_bulk);
2171 }
2172
2173 /* If we don't expect to open a new session, then disallow it */
2174 if (options.control_master == SSHCTL_MASTER_NO &&
2175 (ssh->compat & SSH_NEW_OPENSSH)) {
2176 debug("Requesting no-more-sessions@openssh.com");
2177 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
2178 (r = sshpkt_put_cstring(ssh,
2179 "no-more-sessions@openssh.com")) != 0 ||
2180 (r = sshpkt_put_u8(ssh, 0)) != 0 ||
2181 (r = sshpkt_send(ssh)) != 0)
2182 fatal_fr(r, "send packet");
2183 }
2184
2185 /* Execute a local command */
2186 if (options.local_command != NULL &&
2187 options.permit_local_command)
2188 ssh_local_cmd(options.local_command);
2189
2190 /*
2191 * stdout is now owned by the session channel; clobber it here
2192 * so future channel closes are propagated to the local fd.
2193 * NB. this can only happen after LocalCommand has completed,
2194 * as it may want to write to stdout.
2195 */
2196 if (!need_controlpersist_detach && stdfd_devnull(0, 1, 0) == -1)
2197 error_f("stdfd_devnull failed");
2198
2199 /*
2200 * If requested and we are not interested in replies to remote
2201 * forwarding requests, then let ssh continue in the background.
2202 */
2203 if (options.fork_after_authentication) {
2204 if (options.exit_on_forward_failure &&
2205 options.num_remote_forwards > 0) {
2206 debug("deferring postauth fork until remote forward "
2207 "confirmation received");
2208 } else
2209 fork_postauth();
2210 }
2211
2212 return client_loop(ssh, tty_flag, tty_flag ?
2213 options.escape_char : SSH_ESCAPECHAR_NONE, id);
2214 }
2215
2216 /* Loads all IdentityFile and CertificateFile keys */
2217 static void
load_public_identity_files(const struct ssh_conn_info * cinfo)2218 load_public_identity_files(const struct ssh_conn_info *cinfo)
2219 {
2220 char *filename, *cp;
2221 struct sshkey *public;
2222 int i;
2223 u_int n_ids, n_certs;
2224 char *identity_files[SSH_MAX_IDENTITY_FILES];
2225 struct sshkey *identity_keys[SSH_MAX_IDENTITY_FILES];
2226 int identity_file_userprovided[SSH_MAX_IDENTITY_FILES];
2227 char *certificate_files[SSH_MAX_CERTIFICATE_FILES];
2228 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES];
2229 int certificate_file_userprovided[SSH_MAX_CERTIFICATE_FILES];
2230 #ifdef ENABLE_PKCS11
2231 struct sshkey **keys = NULL;
2232 char **comments = NULL;
2233 int nkeys;
2234 #endif /* PKCS11 */
2235
2236 n_ids = n_certs = 0;
2237 memset(identity_files, 0, sizeof(identity_files));
2238 memset(identity_keys, 0, sizeof(identity_keys));
2239 memset(identity_file_userprovided, 0,
2240 sizeof(identity_file_userprovided));
2241 memset(certificate_files, 0, sizeof(certificate_files));
2242 memset(certificates, 0, sizeof(certificates));
2243 memset(certificate_file_userprovided, 0,
2244 sizeof(certificate_file_userprovided));
2245
2246 #ifdef ENABLE_PKCS11
2247 if (options.pkcs11_provider != NULL &&
2248 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
2249 (pkcs11_init(!options.batch_mode) == 0) &&
2250 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL,
2251 &keys, &comments)) > 0) {
2252 for (i = 0; i < nkeys; i++) {
2253 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
2254 sshkey_free(keys[i]);
2255 free(comments[i]);
2256 continue;
2257 }
2258 identity_keys[n_ids] = keys[i];
2259 identity_files[n_ids] = comments[i]; /* transferred */
2260 n_ids++;
2261 }
2262 free(keys);
2263 free(comments);
2264 }
2265 #endif /* ENABLE_PKCS11 */
2266 for (i = 0; i < options.num_identity_files; i++) {
2267 if (n_ids >= SSH_MAX_IDENTITY_FILES ||
2268 strcasecmp(options.identity_files[i], "none") == 0) {
2269 free(options.identity_files[i]);
2270 options.identity_files[i] = NULL;
2271 continue;
2272 }
2273 cp = tilde_expand_filename(options.identity_files[i], getuid());
2274 filename = default_client_percent_dollar_expand(cp, cinfo);
2275 free(cp);
2276 check_load(sshkey_load_public(filename, &public, NULL),
2277 &public, filename, "pubkey");
2278 debug("identity file %s type %d", filename,
2279 public ? public->type : -1);
2280 free(options.identity_files[i]);
2281 identity_files[n_ids] = filename;
2282 identity_keys[n_ids] = public;
2283 identity_file_userprovided[n_ids] =
2284 options.identity_file_userprovided[i];
2285 if (++n_ids >= SSH_MAX_IDENTITY_FILES)
2286 continue;
2287
2288 /*
2289 * If no certificates have been explicitly listed then try
2290 * to add the default certificate variant too.
2291 */
2292 if (options.num_certificate_files != 0)
2293 continue;
2294 xasprintf(&cp, "%s-cert", filename);
2295 check_load(sshkey_load_public(cp, &public, NULL),
2296 &public, filename, "pubkey");
2297 debug("identity file %s type %d", cp,
2298 public ? public->type : -1);
2299 if (public == NULL) {
2300 free(cp);
2301 continue;
2302 }
2303 if (!sshkey_is_cert(public)) {
2304 debug_f("key %s type %s is not a certificate",
2305 cp, sshkey_type(public));
2306 sshkey_free(public);
2307 free(cp);
2308 continue;
2309 }
2310 /* NB. leave filename pointing to private key */
2311 identity_files[n_ids] = xstrdup(filename);
2312 identity_keys[n_ids] = public;
2313 identity_file_userprovided[n_ids] =
2314 options.identity_file_userprovided[i];
2315 n_ids++;
2316 }
2317
2318 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES)
2319 fatal_f("too many certificates");
2320 for (i = 0; i < options.num_certificate_files; i++) {
2321 cp = tilde_expand_filename(options.certificate_files[i],
2322 getuid());
2323 filename = default_client_percent_dollar_expand(cp, cinfo);
2324 free(cp);
2325
2326 check_load(sshkey_load_public(filename, &public, NULL),
2327 &public, filename, "certificate");
2328 debug("certificate file %s type %d", filename,
2329 public ? public->type : -1);
2330 free(options.certificate_files[i]);
2331 options.certificate_files[i] = NULL;
2332 if (public == NULL) {
2333 free(filename);
2334 continue;
2335 }
2336 if (!sshkey_is_cert(public)) {
2337 debug_f("key %s type %s is not a certificate",
2338 filename, sshkey_type(public));
2339 sshkey_free(public);
2340 free(filename);
2341 continue;
2342 }
2343 certificate_files[n_certs] = filename;
2344 certificates[n_certs] = public;
2345 certificate_file_userprovided[n_certs] =
2346 options.certificate_file_userprovided[i];
2347 ++n_certs;
2348 }
2349
2350 options.num_identity_files = n_ids;
2351 memcpy(options.identity_files, identity_files, sizeof(identity_files));
2352 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys));
2353 memcpy(options.identity_file_userprovided,
2354 identity_file_userprovided, sizeof(identity_file_userprovided));
2355
2356 options.num_certificate_files = n_certs;
2357 memcpy(options.certificate_files,
2358 certificate_files, sizeof(certificate_files));
2359 memcpy(options.certificates, certificates, sizeof(certificates));
2360 memcpy(options.certificate_file_userprovided,
2361 certificate_file_userprovided,
2362 sizeof(certificate_file_userprovided));
2363 }
2364
2365 static void
main_sigchld_handler(int sig)2366 main_sigchld_handler(int sig)
2367 {
2368 int save_errno = errno;
2369 pid_t pid;
2370 int status;
2371
2372 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
2373 (pid == -1 && errno == EINTR))
2374 ;
2375 errno = save_errno;
2376 }
2377