1 /* $OpenBSD: ssh.c,v 1.527 2020/04/10 00:52:07 dtucker Exp $ */
2 /*
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
6 * Ssh client program. This program can be used to log into a remote machine.
7 * The software supports strong authentication, encryption, and forwarding
8 * of X11, TCP/IP, and authentication connections.
9 *
10 * As far as I am concerned, the code I have written for this software
11 * can be used freely for any purpose. Any derived versions of this
12 * software must be clearly marked as such, and if the derived work is
13 * incompatible with the protocol description in the RFC file, it must be
14 * called by a name other than "ssh" or "Secure Shell".
15 *
16 * Copyright (c) 1999 Niels Provos. All rights reserved.
17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved.
18 *
19 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
20 * in Canada (German citizen).
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the above copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 *
31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
41 */
42
43 #include "includes.h"
44
45 #include <sys/types.h>
46 #ifdef HAVE_SYS_STAT_H
47 # include <sys/stat.h>
48 #endif
49 #include <sys/resource.h>
50 #include <sys/ioctl.h>
51 #include <sys/socket.h>
52 #include <sys/wait.h>
53
54 #include <ctype.h>
55 #include <errno.h>
56 #include <fcntl.h>
57 #include <netdb.h>
58 #ifdef HAVE_PATHS_H
59 #include <paths.h>
60 #endif
61 #include <pwd.h>
62 #include <signal.h>
63 #include <stdarg.h>
64 #include <stddef.h>
65 #include <stdio.h>
66 #include <stdlib.h>
67 #include <string.h>
68 #include <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 /* don't exec a shell */
130 int no_shell_flag = 0;
131
132 /*
133 * Flag indicating that nothing should be read from stdin. This can be set
134 * on the command line.
135 */
136 int stdin_null_flag = 0;
137
138 /*
139 * Flag indicating that the current process should be backgrounded and
140 * a new slave launched in the foreground for ControlPersist.
141 */
142 int need_controlpersist_detach = 0;
143
144 /* Copies of flags for ControlPersist foreground slave */
145 int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty;
146
147 /*
148 * Flag indicating that ssh should fork after authentication. This is useful
149 * so that the passphrase can be entered manually, and then ssh goes to the
150 * background.
151 */
152 int fork_after_authentication_flag = 0;
153
154 /*
155 * General data structure for command line options and options configurable
156 * in configuration files. See readconf.h.
157 */
158 Options options;
159
160 /* optional user configfile */
161 char *config = NULL;
162
163 /*
164 * Name of the host we are connecting to. This is the name given on the
165 * command line, or the Hostname specified for the user-supplied name in a
166 * configuration file.
167 */
168 char *host;
169
170 /*
171 * A config can specify a path to forward, overriding SSH_AUTH_SOCK. If this is
172 * not NULL, forward the socket at this path instead.
173 */
174 char *forward_agent_sock_path = NULL;
175
176 /* Various strings used to to percent_expand() arguments */
177 static char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
178 static char uidstr[32], *host_arg, *conn_hash_hex;
179
180 /* socket address the host resolves to */
181 struct sockaddr_storage hostaddr;
182
183 /* Private host keys. */
184 Sensitive sensitive_data;
185
186 /* command to be executed */
187 struct sshbuf *command;
188
189 /* Should we execute a command or invoke a subsystem? */
190 int subsystem_flag = 0;
191
192 /* # of replies received for global requests */
193 static int forward_confirms_pending = -1;
194
195 /* mux.c */
196 extern int muxserver_sock;
197 extern u_int muxclient_command;
198
199 /* Prints a help message to the user. This function never returns. */
200
201 static void
usage(void)202 usage(void)
203 {
204 fprintf(stderr,
205 "usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]\n"
206 " [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]\n"
207 " [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]\n"
208 " [-i identity_file] [-J [user@]host[:port]] [-L address]\n"
209 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
210 " [-Q query_option] [-R address] [-S ctl_path] [-W host:port]\n"
211 " [-w local_tun[:remote_tun]] destination [command]\n"
212 );
213 exit(255);
214 }
215
216 static int ssh_session2(struct ssh *, struct passwd *);
217 static void load_public_identity_files(struct passwd *);
218 static void main_sigchld_handler(int);
219
220 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */
221 static void
tilde_expand_paths(char ** paths,u_int num_paths)222 tilde_expand_paths(char **paths, u_int num_paths)
223 {
224 u_int i;
225 char *cp;
226
227 for (i = 0; i < num_paths; i++) {
228 cp = tilde_expand_filename(paths[i], getuid());
229 free(paths[i]);
230 paths[i] = cp;
231 }
232 }
233
234 #define DEFAULT_CLIENT_PERCENT_EXPAND_ARGS \
235 "C", conn_hash_hex, \
236 "L", shorthost, \
237 "i", uidstr, \
238 "l", thishost, \
239 "n", host_arg, \
240 "p", portstr
241
242 /*
243 * Expands the set of percent_expand options used by the majority of keywords
244 * in the client that support percent expansion.
245 * Caller must free returned string.
246 */
247 static char *
default_client_percent_expand(const char * str,const char * homedir,const char * remhost,const char * remuser,const char * locuser)248 default_client_percent_expand(const char *str, const char *homedir,
249 const char *remhost, const char *remuser, const char *locuser)
250 {
251 return percent_expand(str,
252 /* values from statics above */
253 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS,
254 /* values from arguments */
255 "d", homedir,
256 "h", remhost,
257 "r", remuser,
258 "u", locuser,
259 (char *)NULL);
260 }
261
262 /*
263 * Attempt to resolve a host name / port to a set of addresses and
264 * optionally return any CNAMEs encountered along the way.
265 * Returns NULL on failure.
266 * NB. this function must operate with a options having undefined members.
267 */
268 static struct addrinfo *
resolve_host(const char * name,int port,int logerr,char * cname,size_t clen)269 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen)
270 {
271 char strport[NI_MAXSERV];
272 struct addrinfo hints, *res;
273 int gaierr;
274 LogLevel loglevel = SYSLOG_LEVEL_DEBUG1;
275
276 if (port <= 0)
277 port = default_ssh_port();
278 if (cname != NULL)
279 *cname = '\0';
280
281 snprintf(strport, sizeof strport, "%d", port);
282 memset(&hints, 0, sizeof(hints));
283 hints.ai_family = options.address_family == -1 ?
284 AF_UNSPEC : options.address_family;
285 hints.ai_socktype = SOCK_STREAM;
286 if (cname != NULL)
287 hints.ai_flags = AI_CANONNAME;
288 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
289 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA))
290 loglevel = SYSLOG_LEVEL_ERROR;
291 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s",
292 __progname, name, ssh_gai_strerror(gaierr));
293 return NULL;
294 }
295 if (cname != NULL && res->ai_canonname != NULL) {
296 if (strlcpy(cname, res->ai_canonname, clen) >= clen) {
297 error("%s: host \"%s\" cname \"%s\" too long (max %lu)",
298 __func__, name, res->ai_canonname, (u_long)clen);
299 if (clen > 0)
300 *cname = '\0';
301 }
302 }
303 return res;
304 }
305
306 /* Returns non-zero if name can only be an address and not a hostname */
307 static int
is_addr_fast(const char * name)308 is_addr_fast(const char *name)
309 {
310 return (strchr(name, '%') != NULL || strchr(name, ':') != NULL ||
311 strspn(name, "0123456789.") == strlen(name));
312 }
313
314 /* Returns non-zero if name represents a valid, single address */
315 static int
is_addr(const char * name)316 is_addr(const char *name)
317 {
318 char strport[NI_MAXSERV];
319 struct addrinfo hints, *res;
320
321 if (is_addr_fast(name))
322 return 1;
323
324 snprintf(strport, sizeof strport, "%u", default_ssh_port());
325 memset(&hints, 0, sizeof(hints));
326 hints.ai_family = options.address_family == -1 ?
327 AF_UNSPEC : options.address_family;
328 hints.ai_socktype = SOCK_STREAM;
329 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV;
330 if (getaddrinfo(name, strport, &hints, &res) != 0)
331 return 0;
332 if (res == NULL || res->ai_next != NULL) {
333 freeaddrinfo(res);
334 return 0;
335 }
336 freeaddrinfo(res);
337 return 1;
338 }
339
340 /*
341 * Attempt to resolve a numeric host address / port to a single address.
342 * Returns a canonical address string.
343 * Returns NULL on failure.
344 * NB. this function must operate with a options having undefined members.
345 */
346 static struct addrinfo *
resolve_addr(const char * name,int port,char * caddr,size_t clen)347 resolve_addr(const char *name, int port, char *caddr, size_t clen)
348 {
349 char addr[NI_MAXHOST], strport[NI_MAXSERV];
350 struct addrinfo hints, *res;
351 int gaierr;
352
353 if (port <= 0)
354 port = default_ssh_port();
355 snprintf(strport, sizeof strport, "%u", port);
356 memset(&hints, 0, sizeof(hints));
357 hints.ai_family = options.address_family == -1 ?
358 AF_UNSPEC : options.address_family;
359 hints.ai_socktype = SOCK_STREAM;
360 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV;
361 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
362 debug2("%s: could not resolve name %.100s as address: %s",
363 __func__, name, ssh_gai_strerror(gaierr));
364 return NULL;
365 }
366 if (res == NULL) {
367 debug("%s: getaddrinfo %.100s returned no addresses",
368 __func__, name);
369 return NULL;
370 }
371 if (res->ai_next != NULL) {
372 debug("%s: getaddrinfo %.100s returned multiple addresses",
373 __func__, name);
374 goto fail;
375 }
376 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen,
377 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) {
378 debug("%s: Could not format address for name %.100s: %s",
379 __func__, name, ssh_gai_strerror(gaierr));
380 goto fail;
381 }
382 if (strlcpy(caddr, addr, clen) >= clen) {
383 error("%s: host \"%s\" addr \"%s\" too long (max %lu)",
384 __func__, name, addr, (u_long)clen);
385 if (clen > 0)
386 *caddr = '\0';
387 fail:
388 freeaddrinfo(res);
389 return NULL;
390 }
391 return res;
392 }
393
394 /*
395 * Check whether the cname is a permitted replacement for the hostname
396 * and perform the replacement if it is.
397 * NB. this function must operate with a options having undefined members.
398 */
399 static int
check_follow_cname(int direct,char ** namep,const char * cname)400 check_follow_cname(int direct, char **namep, const char *cname)
401 {
402 int i;
403 struct allowed_cname *rule;
404
405 if (*cname == '\0' || options.num_permitted_cnames == 0 ||
406 strcmp(*namep, cname) == 0)
407 return 0;
408 if (options.canonicalize_hostname == SSH_CANONICALISE_NO)
409 return 0;
410 /*
411 * Don't attempt to canonicalize names that will be interpreted by
412 * a proxy or jump host unless the user specifically requests so.
413 */
414 if (!direct &&
415 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
416 return 0;
417 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname);
418 for (i = 0; i < options.num_permitted_cnames; i++) {
419 rule = options.permitted_cnames + i;
420 if (match_pattern_list(*namep, rule->source_list, 1) != 1 ||
421 match_pattern_list(cname, rule->target_list, 1) != 1)
422 continue;
423 verbose("Canonicalized DNS aliased hostname "
424 "\"%s\" => \"%s\"", *namep, cname);
425 free(*namep);
426 *namep = xstrdup(cname);
427 return 1;
428 }
429 return 0;
430 }
431
432 /*
433 * Attempt to resolve the supplied hostname after applying the user's
434 * canonicalization rules. Returns the address list for the host or NULL
435 * if no name was found after canonicalization.
436 * NB. this function must operate with a options having undefined members.
437 */
438 static struct addrinfo *
resolve_canonicalize(char ** hostp,int port)439 resolve_canonicalize(char **hostp, int port)
440 {
441 int i, direct, ndots;
442 char *cp, *fullhost, newname[NI_MAXHOST];
443 struct addrinfo *addrs;
444
445 /*
446 * Attempt to canonicalise addresses, regardless of
447 * whether hostname canonicalisation was requested
448 */
449 if ((addrs = resolve_addr(*hostp, port,
450 newname, sizeof(newname))) != NULL) {
451 debug2("%s: hostname %.100s is address", __func__, *hostp);
452 if (strcasecmp(*hostp, newname) != 0) {
453 debug2("%s: canonicalised address \"%s\" => \"%s\"",
454 __func__, *hostp, newname);
455 free(*hostp);
456 *hostp = xstrdup(newname);
457 }
458 return addrs;
459 }
460
461 /*
462 * If this looks like an address but didn't parse as one, it might
463 * be an address with an invalid interface scope. Skip further
464 * attempts at canonicalisation.
465 */
466 if (is_addr_fast(*hostp)) {
467 debug("%s: hostname %.100s is an unrecognised address",
468 __func__, *hostp);
469 return NULL;
470 }
471
472 if (options.canonicalize_hostname == SSH_CANONICALISE_NO)
473 return NULL;
474
475 /*
476 * Don't attempt to canonicalize names that will be interpreted by
477 * a proxy unless the user specifically requests so.
478 */
479 direct = option_clear_or_none(options.proxy_command) &&
480 options.jump_host == NULL;
481 if (!direct &&
482 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
483 return NULL;
484
485 /* If domain name is anchored, then resolve it now */
486 if ((*hostp)[strlen(*hostp) - 1] == '.') {
487 debug3("%s: name is fully qualified", __func__);
488 fullhost = xstrdup(*hostp);
489 if ((addrs = resolve_host(fullhost, port, 0,
490 newname, sizeof(newname))) != NULL)
491 goto found;
492 free(fullhost);
493 goto notfound;
494 }
495
496 /* Don't apply canonicalization to sufficiently-qualified hostnames */
497 ndots = 0;
498 for (cp = *hostp; *cp != '\0'; cp++) {
499 if (*cp == '.')
500 ndots++;
501 }
502 if (ndots > options.canonicalize_max_dots) {
503 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)",
504 __func__, *hostp, options.canonicalize_max_dots);
505 return NULL;
506 }
507 /* Attempt each supplied suffix */
508 for (i = 0; i < options.num_canonical_domains; i++) {
509 xasprintf(&fullhost, "%s.%s.", *hostp,
510 options.canonical_domains[i]);
511 debug3("%s: attempting \"%s\" => \"%s\"", __func__,
512 *hostp, fullhost);
513 if ((addrs = resolve_host(fullhost, port, 0,
514 newname, sizeof(newname))) == NULL) {
515 free(fullhost);
516 continue;
517 }
518 found:
519 /* Remove trailing '.' */
520 fullhost[strlen(fullhost) - 1] = '\0';
521 /* Follow CNAME if requested */
522 if (!check_follow_cname(direct, &fullhost, newname)) {
523 debug("Canonicalized hostname \"%s\" => \"%s\"",
524 *hostp, fullhost);
525 }
526 free(*hostp);
527 *hostp = fullhost;
528 return addrs;
529 }
530 notfound:
531 if (!options.canonicalize_fallback_local)
532 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp);
533 debug2("%s: host %s not found in any suffix", __func__, *hostp);
534 return NULL;
535 }
536
537 /*
538 * Check the result of hostkey loading, ignoring some errors and
539 * fatal()ing for others.
540 */
541 static void
check_load(int r,const char * path,const char * message)542 check_load(int r, const char *path, const char *message)
543 {
544 switch (r) {
545 case 0:
546 break;
547 case SSH_ERR_INTERNAL_ERROR:
548 case SSH_ERR_ALLOC_FAIL:
549 fatal("load %s \"%s\": %s", message, path, ssh_err(r));
550 case SSH_ERR_SYSTEM_ERROR:
551 /* Ignore missing files */
552 if (errno == ENOENT)
553 break;
554 /* FALLTHROUGH */
555 default:
556 error("load %s \"%s\": %s", message, path, ssh_err(r));
557 break;
558 }
559 }
560
561 /*
562 * Read per-user configuration file. Ignore the system wide config
563 * file if the user specifies a config file on the command line.
564 */
565 static void
process_config_files(const char * host_name,struct passwd * pw,int final_pass,int * want_final_pass)566 process_config_files(const char *host_name, struct passwd *pw, int final_pass,
567 int *want_final_pass)
568 {
569 char buf[PATH_MAX];
570 int r;
571
572 if (config != NULL) {
573 if (strcasecmp(config, "none") != 0 &&
574 !read_config_file(config, pw, host, host_name, &options,
575 SSHCONF_USERCONF | (final_pass ? SSHCONF_FINAL : 0),
576 want_final_pass))
577 fatal("Can't open user config file %.100s: "
578 "%.100s", config, strerror(errno));
579 } else {
580 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
581 _PATH_SSH_USER_CONFFILE);
582 if (r > 0 && (size_t)r < sizeof(buf))
583 (void)read_config_file(buf, pw, host, host_name,
584 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF |
585 (final_pass ? SSHCONF_FINAL : 0), want_final_pass);
586
587 /* Read systemwide configuration file after user config. */
588 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw,
589 host, host_name, &options,
590 final_pass ? SSHCONF_FINAL : 0, want_final_pass);
591 }
592 }
593
594 /* Rewrite the port number in an addrinfo list of addresses */
595 static void
set_addrinfo_port(struct addrinfo * addrs,int port)596 set_addrinfo_port(struct addrinfo *addrs, int port)
597 {
598 struct addrinfo *addr;
599
600 for (addr = addrs; addr != NULL; addr = addr->ai_next) {
601 switch (addr->ai_family) {
602 case AF_INET:
603 ((struct sockaddr_in *)addr->ai_addr)->
604 sin_port = htons(port);
605 break;
606 case AF_INET6:
607 ((struct sockaddr_in6 *)addr->ai_addr)->
608 sin6_port = htons(port);
609 break;
610 }
611 }
612 }
613
614 /*
615 * Main program for the ssh client.
616 */
617 int
main(int ac,char ** av)618 main(int ac, char **av)
619 {
620 struct ssh *ssh = NULL;
621 int i, r, opt, exit_status, use_syslog, direct, timeout_ms;
622 int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0;
623 char *p, *cp, *line, *argv0, buf[PATH_MAX], *logfile;
624 char cname[NI_MAXHOST];
625 struct stat st;
626 struct passwd *pw;
627 extern int optind, optreset;
628 extern char *optarg;
629 struct Forward fwd;
630 struct addrinfo *addrs = NULL;
631 size_t n, len;
632
633 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
634 sanitise_stdfd();
635
636 __progname = ssh_get_progname(av[0]);
637
638 #ifndef HAVE_SETPROCTITLE
639 /* Prepare for later setproctitle emulation */
640 /* Save argv so it isn't clobbered by setproctitle() emulation */
641 saved_av = xcalloc(ac + 1, sizeof(*saved_av));
642 for (i = 0; i < ac; i++)
643 saved_av[i] = xstrdup(av[i]);
644 saved_av[i] = NULL;
645 compat_init_setproctitle(ac, av);
646 av = saved_av;
647 #endif
648
649 seed_rng();
650
651 /*
652 * Discard other fds that are hanging around. These can cause problem
653 * with backgrounded ssh processes started by ControlPersist.
654 */
655 closefrom(STDERR_FILENO + 1);
656
657 /* Get user data. */
658 pw = getpwuid(getuid());
659 if (!pw) {
660 logit("No user exists for uid %lu", (u_long)getuid());
661 exit(255);
662 }
663 /* Take a copy of the returned structure. */
664 pw = pwcopy(pw);
665
666 /*
667 * Set our umask to something reasonable, as some files are created
668 * with the default umask. This will make them world-readable but
669 * writable only by the owner, which is ok for all files for which we
670 * don't set the modes explicitly.
671 */
672 umask(022);
673
674 msetlocale();
675
676 /*
677 * Initialize option structure to indicate that no values have been
678 * set.
679 */
680 initialize_options(&options);
681
682 /*
683 * Prepare main ssh transport/connection structures
684 */
685 if ((ssh = ssh_alloc_session_state()) == NULL)
686 fatal("Couldn't allocate session state");
687 channel_init_channels(ssh);
688
689 /* Parse command-line arguments. */
690 host = NULL;
691 use_syslog = 0;
692 logfile = NULL;
693 argv0 = av[0];
694
695 again:
696 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
697 "AB:CD:E:F:GI:J:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) {
698 switch (opt) {
699 case '1':
700 fatal("SSH protocol v.1 is no longer supported");
701 break;
702 case '2':
703 /* Ignored */
704 break;
705 case '4':
706 options.address_family = AF_INET;
707 break;
708 case '6':
709 options.address_family = AF_INET6;
710 break;
711 case 'n':
712 stdin_null_flag = 1;
713 break;
714 case 'f':
715 fork_after_authentication_flag = 1;
716 stdin_null_flag = 1;
717 break;
718 case 'x':
719 options.forward_x11 = 0;
720 break;
721 case 'X':
722 options.forward_x11 = 1;
723 break;
724 case 'y':
725 use_syslog = 1;
726 break;
727 case 'E':
728 logfile = optarg;
729 break;
730 case 'G':
731 config_test = 1;
732 break;
733 case 'Y':
734 options.forward_x11 = 1;
735 options.forward_x11_trusted = 1;
736 break;
737 case 'g':
738 options.fwd_opts.gateway_ports = 1;
739 break;
740 case 'O':
741 if (options.stdio_forward_host != NULL)
742 fatal("Cannot specify multiplexing "
743 "command with -W");
744 else if (muxclient_command != 0)
745 fatal("Multiplexing command already specified");
746 if (strcmp(optarg, "check") == 0)
747 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
748 else if (strcmp(optarg, "forward") == 0)
749 muxclient_command = SSHMUX_COMMAND_FORWARD;
750 else if (strcmp(optarg, "exit") == 0)
751 muxclient_command = SSHMUX_COMMAND_TERMINATE;
752 else if (strcmp(optarg, "stop") == 0)
753 muxclient_command = SSHMUX_COMMAND_STOP;
754 else if (strcmp(optarg, "cancel") == 0)
755 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD;
756 else if (strcmp(optarg, "proxy") == 0)
757 muxclient_command = SSHMUX_COMMAND_PROXY;
758 else
759 fatal("Invalid multiplex command.");
760 break;
761 case 'P': /* deprecated */
762 break;
763 case 'Q':
764 cp = NULL;
765 if (strcmp(optarg, "cipher") == 0 ||
766 strcasecmp(optarg, "Ciphers") == 0)
767 cp = cipher_alg_list('\n', 0);
768 else if (strcmp(optarg, "cipher-auth") == 0)
769 cp = cipher_alg_list('\n', 1);
770 else if (strcmp(optarg, "mac") == 0 ||
771 strcasecmp(optarg, "MACs") == 0)
772 cp = mac_alg_list('\n');
773 else if (strcmp(optarg, "kex") == 0 ||
774 strcasecmp(optarg, "KexAlgorithms") == 0)
775 cp = kex_alg_list('\n');
776 else if (strcmp(optarg, "key") == 0)
777 cp = sshkey_alg_list(0, 0, 0, '\n');
778 else if (strcmp(optarg, "key-cert") == 0)
779 cp = sshkey_alg_list(1, 0, 0, '\n');
780 else if (strcmp(optarg, "key-plain") == 0)
781 cp = sshkey_alg_list(0, 1, 0, '\n');
782 else if (strcmp(optarg, "key-sig") == 0 ||
783 strcasecmp(optarg, "PubkeyAcceptedKeyTypes") == 0 ||
784 strcasecmp(optarg, "HostKeyAlgorithms") == 0 ||
785 strcasecmp(optarg, "HostbasedKeyTypes") == 0 ||
786 strcasecmp(optarg, "HostbasedAcceptedKeyTypes") == 0)
787 cp = sshkey_alg_list(0, 0, 1, '\n');
788 else if (strcmp(optarg, "sig") == 0)
789 cp = sshkey_alg_list(0, 1, 1, '\n');
790 else if (strcmp(optarg, "protocol-version") == 0)
791 cp = xstrdup("2");
792 else if (strcmp(optarg, "compression") == 0) {
793 cp = xstrdup(compression_alg_list(0));
794 len = strlen(cp);
795 for (n = 0; n < len; n++)
796 if (cp[n] == ',')
797 cp[n] = '\n';
798 } else if (strcmp(optarg, "help") == 0) {
799 cp = xstrdup(
800 "cipher\ncipher-auth\ncompression\nkex\n"
801 "key\nkey-cert\nkey-plain\nkey-sig\nmac\n"
802 "protocol-version\nsig");
803 }
804 if (cp == NULL)
805 fatal("Unsupported query \"%s\"", optarg);
806 printf("%s\n", cp);
807 free(cp);
808 exit(0);
809 break;
810 case 'a':
811 options.forward_agent = 0;
812 break;
813 case 'A':
814 options.forward_agent = 1;
815 break;
816 case 'k':
817 options.gss_deleg_creds = 0;
818 break;
819 case 'K':
820 options.gss_authentication = 1;
821 options.gss_deleg_creds = 1;
822 break;
823 case 'i':
824 p = tilde_expand_filename(optarg, getuid());
825 if (stat(p, &st) == -1)
826 fprintf(stderr, "Warning: Identity file %s "
827 "not accessible: %s.\n", p,
828 strerror(errno));
829 else
830 add_identity_file(&options, NULL, p, 1);
831 free(p);
832 break;
833 case 'I':
834 #ifdef ENABLE_PKCS11
835 free(options.pkcs11_provider);
836 options.pkcs11_provider = xstrdup(optarg);
837 #else
838 fprintf(stderr, "no support for PKCS#11.\n");
839 #endif
840 break;
841 case 'J':
842 if (options.jump_host != NULL) {
843 fatal("Only a single -J option is permitted "
844 "(use commas to separate multiple "
845 "jump hops)");
846 }
847 if (options.proxy_command != NULL)
848 fatal("Cannot specify -J with ProxyCommand");
849 if (parse_jump(optarg, &options, 1) == -1)
850 fatal("Invalid -J argument");
851 options.proxy_command = xstrdup("none");
852 break;
853 case 't':
854 if (options.request_tty == REQUEST_TTY_YES)
855 options.request_tty = REQUEST_TTY_FORCE;
856 else
857 options.request_tty = REQUEST_TTY_YES;
858 break;
859 case 'v':
860 if (debug_flag == 0) {
861 debug_flag = 1;
862 options.log_level = SYSLOG_LEVEL_DEBUG1;
863 } else {
864 if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
865 debug_flag++;
866 options.log_level++;
867 }
868 }
869 break;
870 case 'V':
871 fprintf(stderr, "%s, %s\n",
872 SSH_RELEASE,
873 #ifdef WITH_OPENSSL
874 OpenSSL_version(OPENSSL_VERSION)
875 #else
876 "without OpenSSL"
877 #endif
878 );
879 if (opt == 'V')
880 exit(0);
881 break;
882 case 'w':
883 if (options.tun_open == -1)
884 options.tun_open = SSH_TUNMODE_DEFAULT;
885 options.tun_local = a2tun(optarg, &options.tun_remote);
886 if (options.tun_local == SSH_TUNID_ERR) {
887 fprintf(stderr,
888 "Bad tun device '%s'\n", optarg);
889 exit(255);
890 }
891 break;
892 case 'W':
893 if (options.stdio_forward_host != NULL)
894 fatal("stdio forward already specified");
895 if (muxclient_command != 0)
896 fatal("Cannot specify stdio forward with -O");
897 if (parse_forward(&fwd, optarg, 1, 0)) {
898 options.stdio_forward_host = fwd.listen_host;
899 options.stdio_forward_port = fwd.listen_port;
900 free(fwd.connect_host);
901 } else {
902 fprintf(stderr,
903 "Bad stdio forwarding specification '%s'\n",
904 optarg);
905 exit(255);
906 }
907 options.request_tty = REQUEST_TTY_NO;
908 no_shell_flag = 1;
909 break;
910 case 'q':
911 options.log_level = SYSLOG_LEVEL_QUIET;
912 break;
913 case 'e':
914 if (optarg[0] == '^' && optarg[2] == 0 &&
915 (u_char) optarg[1] >= 64 &&
916 (u_char) optarg[1] < 128)
917 options.escape_char = (u_char) optarg[1] & 31;
918 else if (strlen(optarg) == 1)
919 options.escape_char = (u_char) optarg[0];
920 else if (strcmp(optarg, "none") == 0)
921 options.escape_char = SSH_ESCAPECHAR_NONE;
922 else {
923 fprintf(stderr, "Bad escape character '%s'.\n",
924 optarg);
925 exit(255);
926 }
927 break;
928 case 'c':
929 if (!ciphers_valid(*optarg == '+' || *optarg == '^' ?
930 optarg + 1 : optarg)) {
931 fprintf(stderr, "Unknown cipher type '%s'\n",
932 optarg);
933 exit(255);
934 }
935 free(options.ciphers);
936 options.ciphers = xstrdup(optarg);
937 break;
938 case 'm':
939 if (mac_valid(optarg)) {
940 free(options.macs);
941 options.macs = xstrdup(optarg);
942 } else {
943 fprintf(stderr, "Unknown mac type '%s'\n",
944 optarg);
945 exit(255);
946 }
947 break;
948 case 'M':
949 if (options.control_master == SSHCTL_MASTER_YES)
950 options.control_master = SSHCTL_MASTER_ASK;
951 else
952 options.control_master = SSHCTL_MASTER_YES;
953 break;
954 case 'p':
955 if (options.port == -1) {
956 options.port = a2port(optarg);
957 if (options.port <= 0) {
958 fprintf(stderr, "Bad port '%s'\n",
959 optarg);
960 exit(255);
961 }
962 }
963 break;
964 case 'l':
965 if (options.user == NULL)
966 options.user = optarg;
967 break;
968
969 case 'L':
970 if (parse_forward(&fwd, optarg, 0, 0))
971 add_local_forward(&options, &fwd);
972 else {
973 fprintf(stderr,
974 "Bad local forwarding specification '%s'\n",
975 optarg);
976 exit(255);
977 }
978 break;
979
980 case 'R':
981 if (parse_forward(&fwd, optarg, 0, 1) ||
982 parse_forward(&fwd, optarg, 1, 1)) {
983 add_remote_forward(&options, &fwd);
984 } else {
985 fprintf(stderr,
986 "Bad remote forwarding specification "
987 "'%s'\n", optarg);
988 exit(255);
989 }
990 break;
991
992 case 'D':
993 if (parse_forward(&fwd, optarg, 1, 0)) {
994 add_local_forward(&options, &fwd);
995 } else {
996 fprintf(stderr,
997 "Bad dynamic forwarding specification "
998 "'%s'\n", optarg);
999 exit(255);
1000 }
1001 break;
1002
1003 case 'C':
1004 #ifdef WITH_ZLIB
1005 options.compression = 1;
1006 #else
1007 error("Compression not supported, disabling.");
1008 #endif
1009 break;
1010 case 'N':
1011 no_shell_flag = 1;
1012 options.request_tty = REQUEST_TTY_NO;
1013 break;
1014 case 'T':
1015 options.request_tty = REQUEST_TTY_NO;
1016 break;
1017 case 'o':
1018 line = xstrdup(optarg);
1019 if (process_config_line(&options, pw,
1020 host ? host : "", host ? host : "", line,
1021 "command-line", 0, NULL, SSHCONF_USERCONF) != 0)
1022 exit(255);
1023 free(line);
1024 break;
1025 case 's':
1026 subsystem_flag = 1;
1027 break;
1028 case 'S':
1029 free(options.control_path);
1030 options.control_path = xstrdup(optarg);
1031 break;
1032 case 'b':
1033 options.bind_address = optarg;
1034 break;
1035 case 'B':
1036 options.bind_interface = optarg;
1037 break;
1038 case 'F':
1039 config = optarg;
1040 break;
1041 default:
1042 usage();
1043 }
1044 }
1045
1046 if (optind > 1 && strcmp(av[optind - 1], "--") == 0)
1047 opt_terminated = 1;
1048
1049 ac -= optind;
1050 av += optind;
1051
1052 if (ac > 0 && !host) {
1053 int tport;
1054 char *tuser;
1055 switch (parse_ssh_uri(*av, &tuser, &host, &tport)) {
1056 case -1:
1057 usage();
1058 break;
1059 case 0:
1060 if (options.user == NULL) {
1061 options.user = tuser;
1062 tuser = NULL;
1063 }
1064 free(tuser);
1065 if (options.port == -1 && tport != -1)
1066 options.port = tport;
1067 break;
1068 default:
1069 p = xstrdup(*av);
1070 cp = strrchr(p, '@');
1071 if (cp != NULL) {
1072 if (cp == p)
1073 usage();
1074 if (options.user == NULL) {
1075 options.user = p;
1076 p = NULL;
1077 }
1078 *cp++ = '\0';
1079 host = xstrdup(cp);
1080 free(p);
1081 } else
1082 host = p;
1083 break;
1084 }
1085 if (ac > 1 && !opt_terminated) {
1086 optind = optreset = 1;
1087 goto again;
1088 }
1089 ac--, av++;
1090 }
1091
1092 /* Check that we got a host name. */
1093 if (!host)
1094 usage();
1095
1096 host_arg = xstrdup(host);
1097
1098 /* Initialize the command to execute on remote host. */
1099 if ((command = sshbuf_new()) == NULL)
1100 fatal("sshbuf_new failed");
1101
1102 /*
1103 * Save the command to execute on the remote host in a buffer. There
1104 * is no limit on the length of the command, except by the maximum
1105 * packet size. Also sets the tty flag if there is no command.
1106 */
1107 if (!ac) {
1108 /* No command specified - execute shell on a tty. */
1109 if (subsystem_flag) {
1110 fprintf(stderr,
1111 "You must specify a subsystem to invoke.\n");
1112 usage();
1113 }
1114 } else {
1115 /* A command has been specified. Store it into the buffer. */
1116 for (i = 0; i < ac; i++) {
1117 if ((r = sshbuf_putf(command, "%s%s",
1118 i ? " " : "", av[i])) != 0)
1119 fatal("%s: buffer error: %s",
1120 __func__, ssh_err(r));
1121 }
1122 }
1123
1124 /*
1125 * Initialize "log" output. Since we are the client all output
1126 * goes to stderr unless otherwise specified by -y or -E.
1127 */
1128 if (use_syslog && logfile != NULL)
1129 fatal("Can't specify both -y and -E");
1130 if (logfile != NULL)
1131 log_redirect_stderr_to(logfile);
1132 log_init(argv0,
1133 options.log_level == SYSLOG_LEVEL_NOT_SET ?
1134 SYSLOG_LEVEL_INFO : options.log_level,
1135 options.log_facility == SYSLOG_FACILITY_NOT_SET ?
1136 SYSLOG_FACILITY_USER : options.log_facility,
1137 !use_syslog);
1138
1139 if (debug_flag)
1140 logit("%s, %s", SSH_RELEASE,
1141 #ifdef WITH_OPENSSL
1142 OpenSSL_version(OPENSSL_VERSION)
1143 #else
1144 "without OpenSSL"
1145 #endif
1146 );
1147
1148 /* Parse the configuration files */
1149 process_config_files(host_arg, pw, 0, &want_final_pass);
1150 if (want_final_pass)
1151 debug("configuration requests final Match pass");
1152
1153 /* Hostname canonicalisation needs a few options filled. */
1154 fill_default_options_for_canonicalization(&options);
1155
1156 /* If the user has replaced the hostname then take it into use now */
1157 if (options.hostname != NULL) {
1158 /* NB. Please keep in sync with readconf.c:match_cfg_line() */
1159 cp = percent_expand(options.hostname,
1160 "h", host, (char *)NULL);
1161 free(host);
1162 host = cp;
1163 free(options.hostname);
1164 options.hostname = xstrdup(host);
1165 }
1166
1167 /* Don't lowercase addresses, they will be explicitly canonicalised */
1168 if ((was_addr = is_addr(host)) == 0)
1169 lowercase(host);
1170
1171 /*
1172 * Try to canonicalize if requested by configuration or the
1173 * hostname is an address.
1174 */
1175 if (options.canonicalize_hostname != SSH_CANONICALISE_NO || was_addr)
1176 addrs = resolve_canonicalize(&host, options.port);
1177
1178 /*
1179 * If CanonicalizePermittedCNAMEs have been specified but
1180 * other canonicalization did not happen (by not being requested
1181 * or by failing with fallback) then the hostname may still be changed
1182 * as a result of CNAME following.
1183 *
1184 * Try to resolve the bare hostname name using the system resolver's
1185 * usual search rules and then apply the CNAME follow rules.
1186 *
1187 * Skip the lookup if a ProxyCommand is being used unless the user
1188 * has specifically requested canonicalisation for this case via
1189 * CanonicalizeHostname=always
1190 */
1191 direct = option_clear_or_none(options.proxy_command) &&
1192 options.jump_host == NULL;
1193 if (addrs == NULL && options.num_permitted_cnames != 0 && (direct ||
1194 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) {
1195 if ((addrs = resolve_host(host, options.port,
1196 direct, cname, sizeof(cname))) == NULL) {
1197 /* Don't fatal proxied host names not in the DNS */
1198 if (direct)
1199 cleanup_exit(255); /* logged in resolve_host */
1200 } else
1201 check_follow_cname(direct, &host, cname);
1202 }
1203
1204 /*
1205 * If canonicalisation is enabled then re-parse the configuration
1206 * files as new stanzas may match.
1207 */
1208 if (options.canonicalize_hostname != 0 && !want_final_pass) {
1209 debug("hostname canonicalisation enabled, "
1210 "will re-parse configuration");
1211 want_final_pass = 1;
1212 }
1213
1214 if (want_final_pass) {
1215 debug("re-parsing configuration");
1216 free(options.hostname);
1217 options.hostname = xstrdup(host);
1218 process_config_files(host_arg, pw, 1, NULL);
1219 /*
1220 * Address resolution happens early with canonicalisation
1221 * enabled and the port number may have changed since, so
1222 * reset it in address list
1223 */
1224 if (addrs != NULL && options.port > 0)
1225 set_addrinfo_port(addrs, options.port);
1226 }
1227
1228 /* Fill configuration defaults. */
1229 fill_default_options(&options);
1230
1231 /*
1232 * If ProxyJump option specified, then construct a ProxyCommand now.
1233 */
1234 if (options.jump_host != NULL) {
1235 char port_s[8];
1236 const char *sshbin = argv0;
1237 int port = options.port, jumpport = options.jump_port;
1238
1239 if (port <= 0)
1240 port = default_ssh_port();
1241 if (jumpport <= 0)
1242 jumpport = default_ssh_port();
1243 if (strcmp(options.jump_host, host) == 0 && port == jumpport)
1244 fatal("jumphost loop via %s", options.jump_host);
1245
1246 /*
1247 * Try to use SSH indicated by argv[0], but fall back to
1248 * "ssh" if it appears unavailable.
1249 */
1250 if (strchr(argv0, '/') != NULL && access(argv0, X_OK) != 0)
1251 sshbin = "ssh";
1252
1253 /* Consistency check */
1254 if (options.proxy_command != NULL)
1255 fatal("inconsistent options: ProxyCommand+ProxyJump");
1256 /* Never use FD passing for ProxyJump */
1257 options.proxy_use_fdpass = 0;
1258 snprintf(port_s, sizeof(port_s), "%d", options.jump_port);
1259 xasprintf(&options.proxy_command,
1260 "%s%s%s%s%s%s%s%s%s%s%.*s -W '[%%h]:%%p' %s",
1261 sshbin,
1262 /* Optional "-l user" argument if jump_user set */
1263 options.jump_user == NULL ? "" : " -l ",
1264 options.jump_user == NULL ? "" : options.jump_user,
1265 /* Optional "-p port" argument if jump_port set */
1266 options.jump_port <= 0 ? "" : " -p ",
1267 options.jump_port <= 0 ? "" : port_s,
1268 /* Optional additional jump hosts ",..." */
1269 options.jump_extra == NULL ? "" : " -J ",
1270 options.jump_extra == NULL ? "" : options.jump_extra,
1271 /* Optional "-F" argumment if -F specified */
1272 config == NULL ? "" : " -F ",
1273 config == NULL ? "" : config,
1274 /* Optional "-v" arguments if -v set */
1275 debug_flag ? " -" : "",
1276 debug_flag, "vvv",
1277 /* Mandatory hostname */
1278 options.jump_host);
1279 debug("Setting implicit ProxyCommand from ProxyJump: %s",
1280 options.proxy_command);
1281 }
1282
1283 if (options.port == 0)
1284 options.port = default_ssh_port();
1285 channel_set_af(ssh, options.address_family);
1286
1287 /* Tidy and check options */
1288 if (options.host_key_alias != NULL)
1289 lowercase(options.host_key_alias);
1290 if (options.proxy_command != NULL &&
1291 strcmp(options.proxy_command, "-") == 0 &&
1292 options.proxy_use_fdpass)
1293 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible");
1294 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) {
1295 if (options.control_persist && options.control_path != NULL) {
1296 debug("UpdateHostKeys=ask is incompatible with "
1297 "ControlPersist; disabling");
1298 options.update_hostkeys = 0;
1299 } else if (sshbuf_len(command) != 0 ||
1300 options.remote_command != NULL ||
1301 options.request_tty == REQUEST_TTY_NO) {
1302 debug("UpdateHostKeys=ask is incompatible with "
1303 "remote command execution; disabling");
1304 options.update_hostkeys = 0;
1305 } else if (options.log_level < SYSLOG_LEVEL_INFO) {
1306 /* no point logging anything; user won't see it */
1307 options.update_hostkeys = 0;
1308 }
1309 }
1310 if (options.connection_attempts <= 0)
1311 fatal("Invalid number of ConnectionAttempts");
1312
1313 if (sshbuf_len(command) != 0 && options.remote_command != NULL)
1314 fatal("Cannot execute command-line and remote command.");
1315
1316 /* Cannot fork to background if no command. */
1317 if (fork_after_authentication_flag && sshbuf_len(command) == 0 &&
1318 options.remote_command == NULL && !no_shell_flag)
1319 fatal("Cannot fork into background without a command "
1320 "to execute.");
1321
1322 /* reinit */
1323 log_init(argv0, options.log_level, options.log_facility, !use_syslog);
1324
1325 if (options.request_tty == REQUEST_TTY_YES ||
1326 options.request_tty == REQUEST_TTY_FORCE)
1327 tty_flag = 1;
1328
1329 /* Allocate a tty by default if no command specified. */
1330 if (sshbuf_len(command) == 0 && options.remote_command == NULL)
1331 tty_flag = options.request_tty != REQUEST_TTY_NO;
1332
1333 /* Force no tty */
1334 if (options.request_tty == REQUEST_TTY_NO ||
1335 (muxclient_command && muxclient_command != SSHMUX_COMMAND_PROXY))
1336 tty_flag = 0;
1337 /* Do not allocate a tty if stdin is not a tty. */
1338 if ((!isatty(fileno(stdin)) || stdin_null_flag) &&
1339 options.request_tty != REQUEST_TTY_FORCE) {
1340 if (tty_flag)
1341 logit("Pseudo-terminal will not be allocated because "
1342 "stdin is not a terminal.");
1343 tty_flag = 0;
1344 }
1345
1346 if (options.user == NULL)
1347 options.user = xstrdup(pw->pw_name);
1348
1349 /* Set up strings used to percent_expand() arguments */
1350 if (gethostname(thishost, sizeof(thishost)) == -1)
1351 fatal("gethostname: %s", strerror(errno));
1352 strlcpy(shorthost, thishost, sizeof(shorthost));
1353 shorthost[strcspn(thishost, ".")] = '\0';
1354 snprintf(portstr, sizeof(portstr), "%d", options.port);
1355 snprintf(uidstr, sizeof(uidstr), "%llu",
1356 (unsigned long long)pw->pw_uid);
1357
1358 conn_hash_hex = ssh_connection_hash(thishost, host, portstr,
1359 options.user);
1360
1361 /*
1362 * Expand tokens in arguments. NB. LocalCommand is expanded later,
1363 * after port-forwarding is set up, so it may pick up any local
1364 * tunnel interface name allocated.
1365 */
1366 if (options.remote_command != NULL) {
1367 debug3("expanding RemoteCommand: %s", options.remote_command);
1368 cp = options.remote_command;
1369 options.remote_command = default_client_percent_expand(cp,
1370 pw->pw_dir, host, options.user, pw->pw_name);
1371 debug3("expanded RemoteCommand: %s", options.remote_command);
1372 free(cp);
1373 if ((r = sshbuf_put(command, options.remote_command,
1374 strlen(options.remote_command))) != 0)
1375 fatal("%s: buffer error: %s", __func__, ssh_err(r));
1376 }
1377
1378 if (options.control_path != NULL) {
1379 cp = tilde_expand_filename(options.control_path, getuid());
1380 free(options.control_path);
1381 options.control_path = default_client_percent_expand(cp,
1382 pw->pw_dir, host, options.user, pw->pw_name);
1383 free(cp);
1384 }
1385
1386 if (options.identity_agent != NULL) {
1387 p = tilde_expand_filename(options.identity_agent, getuid());
1388 cp = default_client_percent_expand(p,
1389 pw->pw_dir, host, options.user, pw->pw_name);
1390 free(p);
1391 free(options.identity_agent);
1392 options.identity_agent = cp;
1393 }
1394
1395 if (options.forward_agent_sock_path != NULL) {
1396 p = tilde_expand_filename(options.forward_agent_sock_path,
1397 getuid());
1398 cp = default_client_percent_expand(p,
1399 pw->pw_dir, host, options.user, pw->pw_name);
1400 free(p);
1401 free(options.forward_agent_sock_path);
1402 options.forward_agent_sock_path = cp;
1403 }
1404
1405 for (i = 0; i < options.num_local_forwards; i++) {
1406 if (options.local_forwards[i].listen_path != NULL) {
1407 cp = options.local_forwards[i].listen_path;
1408 p = options.local_forwards[i].listen_path =
1409 default_client_percent_expand(cp,
1410 pw->pw_dir, host, options.user, pw->pw_name);
1411 if (strcmp(cp, p) != 0)
1412 debug3("expanded LocalForward listen path "
1413 "'%s' -> '%s'", cp, p);
1414 free(cp);
1415 }
1416 if (options.local_forwards[i].connect_path != NULL) {
1417 cp = options.local_forwards[i].connect_path;
1418 p = options.local_forwards[i].connect_path =
1419 default_client_percent_expand(cp,
1420 pw->pw_dir, host, options.user, pw->pw_name);
1421 if (strcmp(cp, p) != 0)
1422 debug3("expanded LocalForward connect path "
1423 "'%s' -> '%s'", cp, p);
1424 free(cp);
1425 }
1426 }
1427
1428 for (i = 0; i < options.num_remote_forwards; i++) {
1429 if (options.remote_forwards[i].listen_path != NULL) {
1430 cp = options.remote_forwards[i].listen_path;
1431 p = options.remote_forwards[i].listen_path =
1432 default_client_percent_expand(cp,
1433 pw->pw_dir, host, options.user, pw->pw_name);
1434 if (strcmp(cp, p) != 0)
1435 debug3("expanded RemoteForward listen path "
1436 "'%s' -> '%s'", cp, p);
1437 free(cp);
1438 }
1439 if (options.remote_forwards[i].connect_path != NULL) {
1440 cp = options.remote_forwards[i].connect_path;
1441 p = options.remote_forwards[i].connect_path =
1442 default_client_percent_expand(cp,
1443 pw->pw_dir, host, options.user, pw->pw_name);
1444 if (strcmp(cp, p) != 0)
1445 debug3("expanded RemoteForward connect path "
1446 "'%s' -> '%s'", cp, p);
1447 free(cp);
1448 }
1449 }
1450
1451 if (config_test) {
1452 dump_client_config(&options, host);
1453 exit(0);
1454 }
1455
1456 /* Expand SecurityKeyProvider if it refers to an environment variable */
1457 if (options.sk_provider != NULL && *options.sk_provider == '$' &&
1458 strlen(options.sk_provider) > 1) {
1459 if ((cp = getenv(options.sk_provider + 1)) == NULL) {
1460 debug("Authenticator provider %s did not resolve; "
1461 "disabling", options.sk_provider);
1462 free(options.sk_provider);
1463 options.sk_provider = NULL;
1464 } else {
1465 debug2("resolved SecurityKeyProvider %s => %s",
1466 options.sk_provider, cp);
1467 free(options.sk_provider);
1468 options.sk_provider = xstrdup(cp);
1469 }
1470 }
1471
1472 if (muxclient_command != 0 && options.control_path == NULL)
1473 fatal("No ControlPath specified for \"-O\" command");
1474 if (options.control_path != NULL) {
1475 int sock;
1476 if ((sock = muxclient(options.control_path)) >= 0) {
1477 ssh_packet_set_connection(ssh, sock, sock);
1478 ssh_packet_set_mux(ssh);
1479 goto skip_connect;
1480 }
1481 }
1482
1483 /*
1484 * If hostname canonicalisation was not enabled, then we may not
1485 * have yet resolved the hostname. Do so now.
1486 */
1487 if (addrs == NULL && options.proxy_command == NULL) {
1488 debug2("resolving \"%s\" port %d", host, options.port);
1489 if ((addrs = resolve_host(host, options.port, 1,
1490 cname, sizeof(cname))) == NULL)
1491 cleanup_exit(255); /* resolve_host logs the error */
1492 }
1493
1494 timeout_ms = options.connection_timeout * 1000;
1495
1496 /* Open a connection to the remote host. */
1497 if (ssh_connect(ssh, host, host_arg, addrs, &hostaddr, options.port,
1498 options.address_family, options.connection_attempts,
1499 &timeout_ms, options.tcp_keep_alive) != 0)
1500 exit(255);
1501
1502 if (addrs != NULL)
1503 freeaddrinfo(addrs);
1504
1505 ssh_packet_set_timeout(ssh, options.server_alive_interval,
1506 options.server_alive_count_max);
1507
1508 if (timeout_ms > 0)
1509 debug3("timeout: %d ms remain after connect", timeout_ms);
1510
1511 /*
1512 * If we successfully made the connection and we have hostbased auth
1513 * enabled, load the public keys so we can later use the ssh-keysign
1514 * helper to sign challenges.
1515 */
1516 sensitive_data.nkeys = 0;
1517 sensitive_data.keys = NULL;
1518 if (options.hostbased_authentication) {
1519 sensitive_data.nkeys = 10;
1520 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
1521 sizeof(struct sshkey));
1522
1523 /* XXX check errors? */
1524 #define L_PUBKEY(p,o) do { \
1525 if ((o) >= sensitive_data.nkeys) \
1526 fatal("%s pubkey out of array bounds", __func__); \
1527 check_load(sshkey_load_public(p, &(sensitive_data.keys[o]), NULL), \
1528 p, "pubkey"); \
1529 } while (0)
1530 #define L_CERT(p,o) do { \
1531 if ((o) >= sensitive_data.nkeys) \
1532 fatal("%s cert out of array bounds", __func__); \
1533 check_load(sshkey_load_cert(p, &(sensitive_data.keys[o])), p, "cert"); \
1534 } while (0)
1535
1536 if (options.hostbased_authentication == 1) {
1537 L_CERT(_PATH_HOST_ECDSA_KEY_FILE, 0);
1538 L_CERT(_PATH_HOST_ED25519_KEY_FILE, 1);
1539 L_CERT(_PATH_HOST_RSA_KEY_FILE, 2);
1540 L_CERT(_PATH_HOST_DSA_KEY_FILE, 3);
1541 L_PUBKEY(_PATH_HOST_ECDSA_KEY_FILE, 4);
1542 L_PUBKEY(_PATH_HOST_ED25519_KEY_FILE, 5);
1543 L_PUBKEY(_PATH_HOST_RSA_KEY_FILE, 6);
1544 L_PUBKEY(_PATH_HOST_DSA_KEY_FILE, 7);
1545 L_CERT(_PATH_HOST_XMSS_KEY_FILE, 8);
1546 L_PUBKEY(_PATH_HOST_XMSS_KEY_FILE, 9);
1547 }
1548 }
1549
1550 /* Create ~/.ssh * directory if it doesn't already exist. */
1551 if (config == NULL) {
1552 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir,
1553 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
1554 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) == -1) {
1555 #ifdef WITH_SELINUX
1556 ssh_selinux_setfscreatecon(buf);
1557 #endif
1558 if (mkdir(buf, 0700) < 0)
1559 error("Could not create directory '%.200s'.",
1560 buf);
1561 #ifdef WITH_SELINUX
1562 ssh_selinux_setfscreatecon(NULL);
1563 #endif
1564 }
1565 }
1566 /* load options.identity_files */
1567 load_public_identity_files(pw);
1568
1569 /* optionally set the SSH_AUTHSOCKET_ENV_NAME variable */
1570 if (options.identity_agent &&
1571 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) {
1572 if (strcmp(options.identity_agent, "none") == 0) {
1573 unsetenv(SSH_AUTHSOCKET_ENV_NAME);
1574 } else {
1575 cp = options.identity_agent;
1576 if (cp[0] == '$') {
1577 if (!valid_env_name(cp + 1)) {
1578 fatal("Invalid IdentityAgent "
1579 "environment variable name %s", cp);
1580 }
1581 if ((p = getenv(cp + 1)) == NULL)
1582 unsetenv(SSH_AUTHSOCKET_ENV_NAME);
1583 else
1584 setenv(SSH_AUTHSOCKET_ENV_NAME, p, 1);
1585 } else {
1586 /* identity_agent specifies a path directly */
1587 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1);
1588 }
1589 }
1590 }
1591
1592 if (options.forward_agent && options.forward_agent_sock_path != NULL) {
1593 cp = options.forward_agent_sock_path;
1594 if (cp[0] == '$') {
1595 if (!valid_env_name(cp + 1)) {
1596 fatal("Invalid ForwardAgent environment variable name %s", cp);
1597 }
1598 if ((p = getenv(cp + 1)) != NULL)
1599 forward_agent_sock_path = p;
1600 else
1601 options.forward_agent = 0;
1602 free(cp);
1603 } else {
1604 forward_agent_sock_path = cp;
1605 }
1606 }
1607
1608 /* Expand ~ in known host file names. */
1609 tilde_expand_paths(options.system_hostfiles,
1610 options.num_system_hostfiles);
1611 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles);
1612
1613 ssh_signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
1614 ssh_signal(SIGCHLD, main_sigchld_handler);
1615
1616 /* Log into the remote system. Never returns if the login fails. */
1617 ssh_login(ssh, &sensitive_data, host, (struct sockaddr *)&hostaddr,
1618 options.port, pw, timeout_ms);
1619
1620 if (ssh_packet_connection_is_on_socket(ssh)) {
1621 verbose("Authenticated to %s ([%s]:%d).", host,
1622 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1623 } else {
1624 verbose("Authenticated to %s (via proxy).", host);
1625 }
1626
1627 /* We no longer need the private host keys. Clear them now. */
1628 if (sensitive_data.nkeys != 0) {
1629 for (i = 0; i < sensitive_data.nkeys; i++) {
1630 if (sensitive_data.keys[i] != NULL) {
1631 /* Destroys contents safely */
1632 debug3("clear hostkey %d", i);
1633 sshkey_free(sensitive_data.keys[i]);
1634 sensitive_data.keys[i] = NULL;
1635 }
1636 }
1637 free(sensitive_data.keys);
1638 }
1639 for (i = 0; i < options.num_identity_files; i++) {
1640 free(options.identity_files[i]);
1641 options.identity_files[i] = NULL;
1642 if (options.identity_keys[i]) {
1643 sshkey_free(options.identity_keys[i]);
1644 options.identity_keys[i] = NULL;
1645 }
1646 }
1647 for (i = 0; i < options.num_certificate_files; i++) {
1648 free(options.certificate_files[i]);
1649 options.certificate_files[i] = NULL;
1650 }
1651
1652 skip_connect:
1653 exit_status = ssh_session2(ssh, pw);
1654 ssh_packet_close(ssh);
1655
1656 if (options.control_path != NULL && muxserver_sock != -1)
1657 unlink(options.control_path);
1658
1659 /* Kill ProxyCommand if it is running. */
1660 ssh_kill_proxy_command();
1661
1662 return exit_status;
1663 }
1664
1665 static void
control_persist_detach(void)1666 control_persist_detach(void)
1667 {
1668 pid_t pid;
1669 int devnull, keep_stderr;
1670
1671 debug("%s: backgrounding master process", __func__);
1672
1673 /*
1674 * master (current process) into the background, and make the
1675 * foreground process a client of the backgrounded master.
1676 */
1677 switch ((pid = fork())) {
1678 case -1:
1679 fatal("%s: fork: %s", __func__, strerror(errno));
1680 case 0:
1681 /* Child: master process continues mainloop */
1682 break;
1683 default:
1684 /* Parent: set up mux slave to connect to backgrounded master */
1685 debug2("%s: background process is %ld", __func__, (long)pid);
1686 stdin_null_flag = ostdin_null_flag;
1687 options.request_tty = orequest_tty;
1688 tty_flag = otty_flag;
1689 close(muxserver_sock);
1690 muxserver_sock = -1;
1691 options.control_master = SSHCTL_MASTER_NO;
1692 muxclient(options.control_path);
1693 /* muxclient() doesn't return on success. */
1694 fatal("Failed to connect to new control master");
1695 }
1696 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
1697 error("%s: open(\"/dev/null\"): %s", __func__,
1698 strerror(errno));
1699 } else {
1700 keep_stderr = log_is_on_stderr() && debug_flag;
1701 if (dup2(devnull, STDIN_FILENO) == -1 ||
1702 dup2(devnull, STDOUT_FILENO) == -1 ||
1703 (!keep_stderr && dup2(devnull, STDERR_FILENO) == -1))
1704 error("%s: dup2: %s", __func__, strerror(errno));
1705 if (devnull > STDERR_FILENO)
1706 close(devnull);
1707 }
1708 daemon(1, 1);
1709 setproctitle("%s [mux]", options.control_path);
1710 }
1711
1712 /* Do fork() after authentication. Used by "ssh -f" */
1713 static void
fork_postauth(void)1714 fork_postauth(void)
1715 {
1716 if (need_controlpersist_detach)
1717 control_persist_detach();
1718 debug("forking to background");
1719 fork_after_authentication_flag = 0;
1720 if (daemon(1, 1) == -1)
1721 fatal("daemon() failed: %.200s", strerror(errno));
1722 }
1723
1724 static void
forwarding_success(void)1725 forwarding_success(void)
1726 {
1727 if (forward_confirms_pending == -1)
1728 return;
1729 if (--forward_confirms_pending == 0) {
1730 debug("%s: all expected forwarding replies received", __func__);
1731 if (fork_after_authentication_flag)
1732 fork_postauth();
1733 } else {
1734 debug2("%s: %d expected forwarding replies remaining",
1735 __func__, forward_confirms_pending);
1736 }
1737 }
1738
1739 /* Callback for remote forward global requests */
1740 static void
ssh_confirm_remote_forward(struct ssh * ssh,int type,u_int32_t seq,void * ctxt)1741 ssh_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt)
1742 {
1743 struct Forward *rfwd = (struct Forward *)ctxt;
1744 u_int port;
1745 int r;
1746
1747 /* XXX verbose() on failure? */
1748 debug("remote forward %s for: listen %s%s%d, connect %s:%d",
1749 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1750 rfwd->listen_path ? rfwd->listen_path :
1751 rfwd->listen_host ? rfwd->listen_host : "",
1752 (rfwd->listen_path || rfwd->listen_host) ? ":" : "",
1753 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path :
1754 rfwd->connect_host, rfwd->connect_port);
1755 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) {
1756 if (type == SSH2_MSG_REQUEST_SUCCESS) {
1757 if ((r = sshpkt_get_u32(ssh, &port)) != 0)
1758 fatal("%s: %s", __func__, ssh_err(r));
1759 if (port > 65535) {
1760 error("Invalid allocated port %u for remote "
1761 "forward to %s:%d", port,
1762 rfwd->connect_host, rfwd->connect_port);
1763 /* Ensure failure processing runs below */
1764 type = SSH2_MSG_REQUEST_FAILURE;
1765 channel_update_permission(ssh,
1766 rfwd->handle, -1);
1767 } else {
1768 rfwd->allocated_port = (int)port;
1769 logit("Allocated port %u for remote "
1770 "forward to %s:%d",
1771 rfwd->allocated_port, rfwd->connect_host,
1772 rfwd->connect_port);
1773 channel_update_permission(ssh,
1774 rfwd->handle, rfwd->allocated_port);
1775 }
1776 } else {
1777 channel_update_permission(ssh, rfwd->handle, -1);
1778 }
1779 }
1780
1781 if (type == SSH2_MSG_REQUEST_FAILURE) {
1782 if (options.exit_on_forward_failure) {
1783 if (rfwd->listen_path != NULL)
1784 fatal("Error: remote port forwarding failed "
1785 "for listen path %s", rfwd->listen_path);
1786 else
1787 fatal("Error: remote port forwarding failed "
1788 "for listen port %d", rfwd->listen_port);
1789 } else {
1790 if (rfwd->listen_path != NULL)
1791 logit("Warning: remote port forwarding failed "
1792 "for listen path %s", rfwd->listen_path);
1793 else
1794 logit("Warning: remote port forwarding failed "
1795 "for listen port %d", rfwd->listen_port);
1796 }
1797 }
1798 forwarding_success();
1799 }
1800
1801 static void
client_cleanup_stdio_fwd(struct ssh * ssh,int id,void * arg)1802 client_cleanup_stdio_fwd(struct ssh *ssh, int id, void *arg)
1803 {
1804 debug("stdio forwarding: done");
1805 cleanup_exit(0);
1806 }
1807
1808 static void
ssh_stdio_confirm(struct ssh * ssh,int id,int success,void * arg)1809 ssh_stdio_confirm(struct ssh *ssh, int id, int success, void *arg)
1810 {
1811 if (!success)
1812 fatal("stdio forwarding failed");
1813 }
1814
1815 static void
ssh_tun_confirm(struct ssh * ssh,int id,int success,void * arg)1816 ssh_tun_confirm(struct ssh *ssh, int id, int success, void *arg)
1817 {
1818 if (!success) {
1819 error("Tunnel forwarding failed");
1820 if (options.exit_on_forward_failure)
1821 cleanup_exit(255);
1822 }
1823
1824 debug("%s: tunnel forward established, id=%d", __func__, id);
1825 forwarding_success();
1826 }
1827
1828 static void
ssh_init_stdio_forwarding(struct ssh * ssh)1829 ssh_init_stdio_forwarding(struct ssh *ssh)
1830 {
1831 Channel *c;
1832 int in, out;
1833
1834 if (options.stdio_forward_host == NULL)
1835 return;
1836
1837 debug3("%s: %s:%d", __func__, options.stdio_forward_host,
1838 options.stdio_forward_port);
1839
1840 if ((in = dup(STDIN_FILENO)) == -1 ||
1841 (out = dup(STDOUT_FILENO)) == -1)
1842 fatal("channel_connect_stdio_fwd: dup() in/out failed");
1843 if ((c = channel_connect_stdio_fwd(ssh, options.stdio_forward_host,
1844 options.stdio_forward_port, in, out)) == NULL)
1845 fatal("%s: channel_connect_stdio_fwd failed", __func__);
1846 channel_register_cleanup(ssh, c->self, client_cleanup_stdio_fwd, 0);
1847 channel_register_open_confirm(ssh, c->self, ssh_stdio_confirm, NULL);
1848 }
1849
1850 static void
ssh_init_forwarding(struct ssh * ssh,char ** ifname)1851 ssh_init_forwarding(struct ssh *ssh, char **ifname)
1852 {
1853 int success = 0;
1854 int i;
1855
1856 if (options.exit_on_forward_failure)
1857 forward_confirms_pending = 0; /* track pending requests */
1858 /* Initiate local TCP/IP port forwardings. */
1859 for (i = 0; i < options.num_local_forwards; i++) {
1860 debug("Local connections to %.200s:%d forwarded to remote "
1861 "address %.200s:%d",
1862 (options.local_forwards[i].listen_path != NULL) ?
1863 options.local_forwards[i].listen_path :
1864 (options.local_forwards[i].listen_host == NULL) ?
1865 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1866 options.local_forwards[i].listen_host,
1867 options.local_forwards[i].listen_port,
1868 (options.local_forwards[i].connect_path != NULL) ?
1869 options.local_forwards[i].connect_path :
1870 options.local_forwards[i].connect_host,
1871 options.local_forwards[i].connect_port);
1872 success += channel_setup_local_fwd_listener(ssh,
1873 &options.local_forwards[i], &options.fwd_opts);
1874 }
1875 if (i > 0 && success != i && options.exit_on_forward_failure)
1876 fatal("Could not request local forwarding.");
1877 if (i > 0 && success == 0)
1878 error("Could not request local forwarding.");
1879
1880 /* Initiate remote TCP/IP port forwardings. */
1881 for (i = 0; i < options.num_remote_forwards; i++) {
1882 debug("Remote connections from %.200s:%d forwarded to "
1883 "local address %.200s:%d",
1884 (options.remote_forwards[i].listen_path != NULL) ?
1885 options.remote_forwards[i].listen_path :
1886 (options.remote_forwards[i].listen_host == NULL) ?
1887 "LOCALHOST" : options.remote_forwards[i].listen_host,
1888 options.remote_forwards[i].listen_port,
1889 (options.remote_forwards[i].connect_path != NULL) ?
1890 options.remote_forwards[i].connect_path :
1891 options.remote_forwards[i].connect_host,
1892 options.remote_forwards[i].connect_port);
1893 if ((options.remote_forwards[i].handle =
1894 channel_request_remote_forwarding(ssh,
1895 &options.remote_forwards[i])) >= 0) {
1896 client_register_global_confirm(
1897 ssh_confirm_remote_forward,
1898 &options.remote_forwards[i]);
1899 forward_confirms_pending++;
1900 } else if (options.exit_on_forward_failure)
1901 fatal("Could not request remote forwarding.");
1902 else
1903 logit("Warning: Could not request remote forwarding.");
1904 }
1905
1906 /* Initiate tunnel forwarding. */
1907 if (options.tun_open != SSH_TUNMODE_NO) {
1908 if ((*ifname = client_request_tun_fwd(ssh,
1909 options.tun_open, options.tun_local,
1910 options.tun_remote, ssh_tun_confirm, NULL)) != NULL)
1911 forward_confirms_pending++;
1912 else if (options.exit_on_forward_failure)
1913 fatal("Could not request tunnel forwarding.");
1914 else
1915 error("Could not request tunnel forwarding.");
1916 }
1917 if (forward_confirms_pending > 0) {
1918 debug("%s: expecting replies for %d forwards", __func__,
1919 forward_confirms_pending);
1920 }
1921 }
1922
1923 static void
check_agent_present(void)1924 check_agent_present(void)
1925 {
1926 int r;
1927
1928 if (options.forward_agent) {
1929 /* Clear agent forwarding if we don't have an agent. */
1930 if ((r = ssh_get_authentication_socket(NULL)) != 0) {
1931 options.forward_agent = 0;
1932 if (r != SSH_ERR_AGENT_NOT_PRESENT)
1933 debug("ssh_get_authentication_socket: %s",
1934 ssh_err(r));
1935 }
1936 }
1937 }
1938
1939 static void
ssh_session2_setup(struct ssh * ssh,int id,int success,void * arg)1940 ssh_session2_setup(struct ssh *ssh, int id, int success, void *arg)
1941 {
1942 extern char **environ;
1943 const char *display;
1944 int r, interactive = tty_flag;
1945 char *proto = NULL, *data = NULL;
1946
1947 if (!success)
1948 return; /* No need for error message, channels code sens one */
1949
1950 display = getenv("DISPLAY");
1951 if (display == NULL && options.forward_x11)
1952 debug("X11 forwarding requested but DISPLAY not set");
1953 if (options.forward_x11 && client_x11_get_proto(ssh, display,
1954 options.xauth_location, options.forward_x11_trusted,
1955 options.forward_x11_timeout, &proto, &data) == 0) {
1956 /* Request forwarding with authentication spoofing. */
1957 debug("Requesting X11 forwarding with authentication "
1958 "spoofing.");
1959 x11_request_forwarding_with_spoofing(ssh, id, display, proto,
1960 data, 1);
1961 client_expect_confirm(ssh, id, "X11 forwarding", CONFIRM_WARN);
1962 /* XXX exit_on_forward_failure */
1963 interactive = 1;
1964 }
1965
1966 check_agent_present();
1967 if (options.forward_agent) {
1968 debug("Requesting authentication agent forwarding.");
1969 channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0);
1970 if ((r = sshpkt_send(ssh)) != 0)
1971 fatal("%s: %s", __func__, ssh_err(r));
1972 }
1973
1974 /* Tell the packet module whether this is an interactive session. */
1975 ssh_packet_set_interactive(ssh, interactive,
1976 options.ip_qos_interactive, options.ip_qos_bulk);
1977
1978 client_session2_setup(ssh, id, tty_flag, subsystem_flag, getenv("TERM"),
1979 NULL, fileno(stdin), command, environ);
1980 }
1981
1982 /* open new channel for a session */
1983 static int
ssh_session2_open(struct ssh * ssh)1984 ssh_session2_open(struct ssh *ssh)
1985 {
1986 Channel *c;
1987 int window, packetmax, in, out, err;
1988
1989 if (stdin_null_flag) {
1990 in = open(_PATH_DEVNULL, O_RDONLY);
1991 } else {
1992 in = dup(STDIN_FILENO);
1993 }
1994 out = dup(STDOUT_FILENO);
1995 err = dup(STDERR_FILENO);
1996
1997 if (in == -1 || out == -1 || err == -1)
1998 fatal("dup() in/out/err failed");
1999
2000 /* enable nonblocking unless tty */
2001 if (!isatty(in))
2002 set_nonblock(in);
2003 if (!isatty(out))
2004 set_nonblock(out);
2005 if (!isatty(err))
2006 set_nonblock(err);
2007
2008 window = CHAN_SES_WINDOW_DEFAULT;
2009 packetmax = CHAN_SES_PACKET_DEFAULT;
2010 if (tty_flag) {
2011 window >>= 1;
2012 packetmax >>= 1;
2013 }
2014 c = channel_new(ssh,
2015 "session", SSH_CHANNEL_OPENING, in, out, err,
2016 window, packetmax, CHAN_EXTENDED_WRITE,
2017 "client-session", /*nonblock*/0);
2018
2019 debug3("%s: channel_new: %d", __func__, c->self);
2020
2021 channel_send_open(ssh, c->self);
2022 if (!no_shell_flag)
2023 channel_register_open_confirm(ssh, c->self,
2024 ssh_session2_setup, NULL);
2025
2026 return c->self;
2027 }
2028
2029 static int
ssh_session2(struct ssh * ssh,struct passwd * pw)2030 ssh_session2(struct ssh *ssh, struct passwd *pw)
2031 {
2032 int r, devnull, id = -1;
2033 char *cp, *tun_fwd_ifname = NULL;
2034
2035 /* XXX should be pre-session */
2036 if (!options.control_persist)
2037 ssh_init_stdio_forwarding(ssh);
2038
2039 ssh_init_forwarding(ssh, &tun_fwd_ifname);
2040
2041 if (options.local_command != NULL) {
2042 debug3("expanding LocalCommand: %s", options.local_command);
2043 cp = options.local_command;
2044 options.local_command = percent_expand(cp,
2045 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS,
2046 "d", pw->pw_dir,
2047 "h", host,
2048 "r", options.user,
2049 "u", pw->pw_name,
2050 "T", tun_fwd_ifname == NULL ? "NONE" : tun_fwd_ifname,
2051 (char *)NULL);
2052 debug3("expanded LocalCommand: %s", options.local_command);
2053 free(cp);
2054 }
2055
2056 /* Start listening for multiplex clients */
2057 if (!ssh_packet_get_mux(ssh))
2058 muxserver_listen(ssh);
2059
2060 /*
2061 * If we are in control persist mode and have a working mux listen
2062 * socket, then prepare to background ourselves and have a foreground
2063 * client attach as a control slave.
2064 * NB. we must save copies of the flags that we override for
2065 * the backgrounding, since we defer attachment of the slave until
2066 * after the connection is fully established (in particular,
2067 * async rfwd replies have been received for ExitOnForwardFailure).
2068 */
2069 if (options.control_persist && muxserver_sock != -1) {
2070 ostdin_null_flag = stdin_null_flag;
2071 ono_shell_flag = no_shell_flag;
2072 orequest_tty = options.request_tty;
2073 otty_flag = tty_flag;
2074 stdin_null_flag = 1;
2075 no_shell_flag = 1;
2076 tty_flag = 0;
2077 if (!fork_after_authentication_flag)
2078 need_controlpersist_detach = 1;
2079 fork_after_authentication_flag = 1;
2080 }
2081 /*
2082 * ControlPersist mux listen socket setup failed, attempt the
2083 * stdio forward setup that we skipped earlier.
2084 */
2085 if (options.control_persist && muxserver_sock == -1)
2086 ssh_init_stdio_forwarding(ssh);
2087
2088 if (!no_shell_flag)
2089 id = ssh_session2_open(ssh);
2090 else {
2091 ssh_packet_set_interactive(ssh,
2092 options.control_master == SSHCTL_MASTER_NO,
2093 options.ip_qos_interactive, options.ip_qos_bulk);
2094 }
2095
2096 /* If we don't expect to open a new session, then disallow it */
2097 if (options.control_master == SSHCTL_MASTER_NO &&
2098 (datafellows & SSH_NEW_OPENSSH)) {
2099 debug("Requesting no-more-sessions@openssh.com");
2100 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
2101 (r = sshpkt_put_cstring(ssh,
2102 "no-more-sessions@openssh.com")) != 0 ||
2103 (r = sshpkt_put_u8(ssh, 0)) != 0 ||
2104 (r = sshpkt_send(ssh)) != 0)
2105 fatal("%s: %s", __func__, ssh_err(r));
2106 }
2107
2108 /* Execute a local command */
2109 if (options.local_command != NULL &&
2110 options.permit_local_command)
2111 ssh_local_cmd(options.local_command);
2112
2113 /*
2114 * stdout is now owned by the session channel; clobber it here
2115 * so future channel closes are propagated to the local fd.
2116 * NB. this can only happen after LocalCommand has completed,
2117 * as it may want to write to stdout.
2118 */
2119 if (!need_controlpersist_detach) {
2120 if ((devnull = open(_PATH_DEVNULL, O_WRONLY)) == -1)
2121 error("%s: open %s: %s", __func__,
2122 _PATH_DEVNULL, strerror(errno));
2123 if (dup2(devnull, STDOUT_FILENO) == -1)
2124 fatal("%s: dup2() stdout failed", __func__);
2125 if (devnull > STDERR_FILENO)
2126 close(devnull);
2127 }
2128
2129 /*
2130 * If requested and we are not interested in replies to remote
2131 * forwarding requests, then let ssh continue in the background.
2132 */
2133 if (fork_after_authentication_flag) {
2134 if (options.exit_on_forward_failure &&
2135 options.num_remote_forwards > 0) {
2136 debug("deferring postauth fork until remote forward "
2137 "confirmation received");
2138 } else
2139 fork_postauth();
2140 }
2141
2142 return client_loop(ssh, tty_flag, tty_flag ?
2143 options.escape_char : SSH_ESCAPECHAR_NONE, id);
2144 }
2145
2146 /* Loads all IdentityFile and CertificateFile keys */
2147 static void
load_public_identity_files(struct passwd * pw)2148 load_public_identity_files(struct passwd *pw)
2149 {
2150 char *filename, *cp;
2151 struct sshkey *public;
2152 int i;
2153 u_int n_ids, n_certs;
2154 char *identity_files[SSH_MAX_IDENTITY_FILES];
2155 struct sshkey *identity_keys[SSH_MAX_IDENTITY_FILES];
2156 int identity_file_userprovided[SSH_MAX_IDENTITY_FILES];
2157 char *certificate_files[SSH_MAX_CERTIFICATE_FILES];
2158 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES];
2159 int certificate_file_userprovided[SSH_MAX_CERTIFICATE_FILES];
2160 #ifdef ENABLE_PKCS11
2161 struct sshkey **keys = NULL;
2162 char **comments = NULL;
2163 int nkeys;
2164 #endif /* PKCS11 */
2165
2166 n_ids = n_certs = 0;
2167 memset(identity_files, 0, sizeof(identity_files));
2168 memset(identity_keys, 0, sizeof(identity_keys));
2169 memset(identity_file_userprovided, 0,
2170 sizeof(identity_file_userprovided));
2171 memset(certificate_files, 0, sizeof(certificate_files));
2172 memset(certificates, 0, sizeof(certificates));
2173 memset(certificate_file_userprovided, 0,
2174 sizeof(certificate_file_userprovided));
2175
2176 #ifdef ENABLE_PKCS11
2177 if (options.pkcs11_provider != NULL &&
2178 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
2179 (pkcs11_init(!options.batch_mode) == 0) &&
2180 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL,
2181 &keys, &comments)) > 0) {
2182 for (i = 0; i < nkeys; i++) {
2183 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
2184 sshkey_free(keys[i]);
2185 free(comments[i]);
2186 continue;
2187 }
2188 identity_keys[n_ids] = keys[i];
2189 identity_files[n_ids] = comments[i]; /* transferred */
2190 n_ids++;
2191 }
2192 free(keys);
2193 free(comments);
2194 }
2195 #endif /* ENABLE_PKCS11 */
2196 for (i = 0; i < options.num_identity_files; i++) {
2197 if (n_ids >= SSH_MAX_IDENTITY_FILES ||
2198 strcasecmp(options.identity_files[i], "none") == 0) {
2199 free(options.identity_files[i]);
2200 options.identity_files[i] = NULL;
2201 continue;
2202 }
2203 cp = tilde_expand_filename(options.identity_files[i], getuid());
2204 filename = default_client_percent_expand(cp,
2205 pw->pw_dir, host, options.user, pw->pw_name);
2206 free(cp);
2207 check_load(sshkey_load_public(filename, &public, NULL),
2208 filename, "pubkey");
2209 debug("identity file %s type %d", filename,
2210 public ? public->type : -1);
2211 free(options.identity_files[i]);
2212 identity_files[n_ids] = filename;
2213 identity_keys[n_ids] = public;
2214 identity_file_userprovided[n_ids] =
2215 options.identity_file_userprovided[i];
2216 if (++n_ids >= SSH_MAX_IDENTITY_FILES)
2217 continue;
2218
2219 /*
2220 * If no certificates have been explicitly listed then try
2221 * to add the default certificate variant too.
2222 */
2223 if (options.num_certificate_files != 0)
2224 continue;
2225 xasprintf(&cp, "%s-cert", filename);
2226 check_load(sshkey_load_public(cp, &public, NULL),
2227 filename, "pubkey");
2228 debug("identity file %s type %d", cp,
2229 public ? public->type : -1);
2230 if (public == NULL) {
2231 free(cp);
2232 continue;
2233 }
2234 if (!sshkey_is_cert(public)) {
2235 debug("%s: key %s type %s is not a certificate",
2236 __func__, cp, sshkey_type(public));
2237 sshkey_free(public);
2238 free(cp);
2239 continue;
2240 }
2241 /* NB. leave filename pointing to private key */
2242 identity_files[n_ids] = xstrdup(filename);
2243 identity_keys[n_ids] = public;
2244 identity_file_userprovided[n_ids] =
2245 options.identity_file_userprovided[i];
2246 n_ids++;
2247 }
2248
2249 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES)
2250 fatal("%s: too many certificates", __func__);
2251 for (i = 0; i < options.num_certificate_files; i++) {
2252 cp = tilde_expand_filename(options.certificate_files[i],
2253 getuid());
2254 filename = default_client_percent_expand(cp,
2255 pw->pw_dir, host, options.user, pw->pw_name);
2256 free(cp);
2257
2258 check_load(sshkey_load_public(filename, &public, NULL),
2259 filename, "certificate");
2260 debug("certificate file %s type %d", filename,
2261 public ? public->type : -1);
2262 free(options.certificate_files[i]);
2263 options.certificate_files[i] = NULL;
2264 if (public == NULL) {
2265 free(filename);
2266 continue;
2267 }
2268 if (!sshkey_is_cert(public)) {
2269 debug("%s: key %s type %s is not a certificate",
2270 __func__, filename, sshkey_type(public));
2271 sshkey_free(public);
2272 free(filename);
2273 continue;
2274 }
2275 certificate_files[n_certs] = filename;
2276 certificates[n_certs] = public;
2277 certificate_file_userprovided[n_certs] =
2278 options.certificate_file_userprovided[i];
2279 ++n_certs;
2280 }
2281
2282 options.num_identity_files = n_ids;
2283 memcpy(options.identity_files, identity_files, sizeof(identity_files));
2284 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys));
2285 memcpy(options.identity_file_userprovided,
2286 identity_file_userprovided, sizeof(identity_file_userprovided));
2287
2288 options.num_certificate_files = n_certs;
2289 memcpy(options.certificate_files,
2290 certificate_files, sizeof(certificate_files));
2291 memcpy(options.certificates, certificates, sizeof(certificates));
2292 memcpy(options.certificate_file_userprovided,
2293 certificate_file_userprovided,
2294 sizeof(certificate_file_userprovided));
2295 }
2296
2297 static void
main_sigchld_handler(int sig)2298 main_sigchld_handler(int sig)
2299 {
2300 int save_errno = errno;
2301 pid_t pid;
2302 int status;
2303
2304 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
2305 (pid == -1 && errno == EINTR))
2306 ;
2307 errno = save_errno;
2308 }
2309