1 /* $OpenBSD: ssh.c,v 1.451 2017/03/10 04:07:20 djm Exp $ */
2 /*
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
6 * Ssh client program. This program can be used to log into a remote machine.
7 * The software supports strong authentication, encryption, and forwarding
8 * of X11, TCP/IP, and authentication connections.
9 *
10 * As far as I am concerned, the code I have written for this software
11 * can be used freely for any purpose. Any derived versions of this
12 * software must be clearly marked as such, and if the derived work is
13 * incompatible with the protocol description in the RFC file, it must be
14 * called by a name other than "ssh" or "Secure Shell".
15 *
16 * Copyright (c) 1999 Niels Provos. All rights reserved.
17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved.
18 *
19 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
20 * in Canada (German citizen).
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
25 * 1. Redistributions of source code must retain the above copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
30 *
31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
41 */
42
43 #include "includes.h"
44
45 #include <sys/types.h>
46 #ifdef HAVE_SYS_STAT_H
47 # include <sys/stat.h>
48 #endif
49 #include <sys/resource.h>
50 #include <sys/ioctl.h>
51 #include <sys/socket.h>
52 #include <sys/wait.h>
53
54 #include <ctype.h>
55 #include <errno.h>
56 #include <fcntl.h>
57 #include <netdb.h>
58 #ifdef HAVE_PATHS_H
59 #include <paths.h>
60 #endif
61 #include <pwd.h>
62 #include <signal.h>
63 #include <stdarg.h>
64 #include <stddef.h>
65 #include <stdio.h>
66 #include <stdlib.h>
67 #include <string.h>
68 #include <unistd.h>
69 #include <limits.h>
70 #include <locale.h>
71
72 #include <netinet/in.h>
73 #include <arpa/inet.h>
74
75 #ifdef WITH_OPENSSL
76 #include <openssl/evp.h>
77 #include <openssl/err.h>
78 #endif
79 #include "openbsd-compat/openssl-compat.h"
80 #include "openbsd-compat/sys-queue.h"
81
82 #include "xmalloc.h"
83 #include "ssh.h"
84 #include "ssh1.h"
85 #include "ssh2.h"
86 #include "canohost.h"
87 #include "compat.h"
88 #include "cipher.h"
89 #include "digest.h"
90 #include "packet.h"
91 #include "buffer.h"
92 #include "channels.h"
93 #include "key.h"
94 #include "authfd.h"
95 #include "authfile.h"
96 #include "pathnames.h"
97 #include "dispatch.h"
98 #include "clientloop.h"
99 #include "log.h"
100 #include "misc.h"
101 #include "readconf.h"
102 #include "sshconnect.h"
103 #include "kex.h"
104 #include "mac.h"
105 #include "sshpty.h"
106 #include "match.h"
107 #include "msg.h"
108 #include "uidswap.h"
109 #include "version.h"
110 #include "ssherr.h"
111 #include "myproposal.h"
112 #include "utf8.h"
113
114 #ifdef ENABLE_PKCS11
115 #include "ssh-pkcs11.h"
116 #endif
117
118 extern char *__progname;
119
120 /* Saves a copy of argv for setproctitle emulation */
121 #ifndef HAVE_SETPROCTITLE
122 static char **saved_av;
123 #endif
124
125 /* Flag indicating whether debug mode is on. May be set on the command line. */
126 int debug_flag = 0;
127
128 /* Flag indicating whether a tty should be requested */
129 int tty_flag = 0;
130
131 /* don't exec a shell */
132 int no_shell_flag = 0;
133
134 /*
135 * Flag indicating that nothing should be read from stdin. This can be set
136 * on the command line.
137 */
138 int stdin_null_flag = 0;
139
140 /*
141 * Flag indicating that the current process should be backgrounded and
142 * a new slave launched in the foreground for ControlPersist.
143 */
144 int need_controlpersist_detach = 0;
145
146 /* Copies of flags for ControlPersist foreground slave */
147 int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty;
148
149 /*
150 * Flag indicating that ssh should fork after authentication. This is useful
151 * so that the passphrase can be entered manually, and then ssh goes to the
152 * background.
153 */
154 int fork_after_authentication_flag = 0;
155
156 /*
157 * General data structure for command line options and options configurable
158 * in configuration files. See readconf.h.
159 */
160 Options options;
161
162 /* optional user configfile */
163 char *config = NULL;
164
165 /*
166 * Name of the host we are connecting to. This is the name given on the
167 * command line, or the HostName specified for the user-supplied name in a
168 * configuration file.
169 */
170 char *host;
171
172 /* socket address the host resolves to */
173 struct sockaddr_storage hostaddr;
174
175 /* Private host keys. */
176 Sensitive sensitive_data;
177
178 /* Original real UID. */
179 uid_t original_real_uid;
180 uid_t original_effective_uid;
181
182 /* command to be executed */
183 Buffer command;
184
185 /* Should we execute a command or invoke a subsystem? */
186 int subsystem_flag = 0;
187
188 /* # of replies received for global requests */
189 static int remote_forward_confirms_received = 0;
190
191 /* mux.c */
192 extern int muxserver_sock;
193 extern u_int muxclient_command;
194
195 /* Prints a help message to the user. This function never returns. */
196
197 static void
usage(void)198 usage(void)
199 {
200 fprintf(stderr,
201 "usage: ssh [-1246AaCfGgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n"
202 " [-D [bind_address:]port] [-E log_file] [-e escape_char]\n"
203 " [-F configfile] [-I pkcs11] [-i identity_file]\n"
204 " [-J [user@]host[:port]] [-L address] [-l login_name] [-m mac_spec]\n"
205 " [-O ctl_cmd] [-o option] [-p port] [-Q query_option] [-R address]\n"
206 " [-S ctl_path] [-W host:port] [-w local_tun[:remote_tun]]\n"
207 " [user@]hostname [command]\n"
208 );
209 exit(255);
210 }
211
212 static int ssh_session(void);
213 static int ssh_session2(void);
214 static void load_public_identity_files(void);
215 static void main_sigchld_handler(int);
216
217 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */
218 static void
tilde_expand_paths(char ** paths,u_int num_paths)219 tilde_expand_paths(char **paths, u_int num_paths)
220 {
221 u_int i;
222 char *cp;
223
224 for (i = 0; i < num_paths; i++) {
225 cp = tilde_expand_filename(paths[i], original_real_uid);
226 free(paths[i]);
227 paths[i] = cp;
228 }
229 }
230
231 /*
232 * Attempt to resolve a host name / port to a set of addresses and
233 * optionally return any CNAMEs encountered along the way.
234 * Returns NULL on failure.
235 * NB. this function must operate with a options having undefined members.
236 */
237 static struct addrinfo *
resolve_host(const char * name,int port,int logerr,char * cname,size_t clen)238 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen)
239 {
240 char strport[NI_MAXSERV];
241 struct addrinfo hints, *res;
242 int gaierr, loglevel = SYSLOG_LEVEL_DEBUG1;
243
244 if (port <= 0)
245 port = default_ssh_port();
246
247 snprintf(strport, sizeof strport, "%d", port);
248 memset(&hints, 0, sizeof(hints));
249 hints.ai_family = options.address_family == -1 ?
250 AF_UNSPEC : options.address_family;
251 hints.ai_socktype = SOCK_STREAM;
252 if (cname != NULL)
253 hints.ai_flags = AI_CANONNAME;
254 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
255 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA))
256 loglevel = SYSLOG_LEVEL_ERROR;
257 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s",
258 __progname, name, ssh_gai_strerror(gaierr));
259 return NULL;
260 }
261 if (cname != NULL && res->ai_canonname != NULL) {
262 if (strlcpy(cname, res->ai_canonname, clen) >= clen) {
263 error("%s: host \"%s\" cname \"%s\" too long (max %lu)",
264 __func__, name, res->ai_canonname, (u_long)clen);
265 if (clen > 0)
266 *cname = '\0';
267 }
268 }
269 return res;
270 }
271
272 /*
273 * Attempt to resolve a numeric host address / port to a single address.
274 * Returns a canonical address string.
275 * Returns NULL on failure.
276 * NB. this function must operate with a options having undefined members.
277 */
278 static struct addrinfo *
resolve_addr(const char * name,int port,char * caddr,size_t clen)279 resolve_addr(const char *name, int port, char *caddr, size_t clen)
280 {
281 char addr[NI_MAXHOST], strport[NI_MAXSERV];
282 struct addrinfo hints, *res;
283 int gaierr;
284
285 if (port <= 0)
286 port = default_ssh_port();
287 snprintf(strport, sizeof strport, "%u", port);
288 memset(&hints, 0, sizeof(hints));
289 hints.ai_family = options.address_family == -1 ?
290 AF_UNSPEC : options.address_family;
291 hints.ai_socktype = SOCK_STREAM;
292 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV;
293 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
294 debug2("%s: could not resolve name %.100s as address: %s",
295 __func__, name, ssh_gai_strerror(gaierr));
296 return NULL;
297 }
298 if (res == NULL) {
299 debug("%s: getaddrinfo %.100s returned no addresses",
300 __func__, name);
301 return NULL;
302 }
303 if (res->ai_next != NULL) {
304 debug("%s: getaddrinfo %.100s returned multiple addresses",
305 __func__, name);
306 goto fail;
307 }
308 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen,
309 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) {
310 debug("%s: Could not format address for name %.100s: %s",
311 __func__, name, ssh_gai_strerror(gaierr));
312 goto fail;
313 }
314 if (strlcpy(caddr, addr, clen) >= clen) {
315 error("%s: host \"%s\" addr \"%s\" too long (max %lu)",
316 __func__, name, addr, (u_long)clen);
317 if (clen > 0)
318 *caddr = '\0';
319 fail:
320 freeaddrinfo(res);
321 return NULL;
322 }
323 return res;
324 }
325
326 /*
327 * Check whether the cname is a permitted replacement for the hostname
328 * and perform the replacement if it is.
329 * NB. this function must operate with a options having undefined members.
330 */
331 static int
check_follow_cname(int direct,char ** namep,const char * cname)332 check_follow_cname(int direct, char **namep, const char *cname)
333 {
334 int i;
335 struct allowed_cname *rule;
336
337 if (*cname == '\0' || options.num_permitted_cnames == 0 ||
338 strcmp(*namep, cname) == 0)
339 return 0;
340 if (options.canonicalize_hostname == SSH_CANONICALISE_NO)
341 return 0;
342 /*
343 * Don't attempt to canonicalize names that will be interpreted by
344 * a proxy or jump host unless the user specifically requests so.
345 */
346 if (!direct &&
347 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
348 return 0;
349 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname);
350 for (i = 0; i < options.num_permitted_cnames; i++) {
351 rule = options.permitted_cnames + i;
352 if (match_pattern_list(*namep, rule->source_list, 1) != 1 ||
353 match_pattern_list(cname, rule->target_list, 1) != 1)
354 continue;
355 verbose("Canonicalized DNS aliased hostname "
356 "\"%s\" => \"%s\"", *namep, cname);
357 free(*namep);
358 *namep = xstrdup(cname);
359 return 1;
360 }
361 return 0;
362 }
363
364 /*
365 * Attempt to resolve the supplied hostname after applying the user's
366 * canonicalization rules. Returns the address list for the host or NULL
367 * if no name was found after canonicalization.
368 * NB. this function must operate with a options having undefined members.
369 */
370 static struct addrinfo *
resolve_canonicalize(char ** hostp,int port)371 resolve_canonicalize(char **hostp, int port)
372 {
373 int i, direct, ndots;
374 char *cp, *fullhost, newname[NI_MAXHOST];
375 struct addrinfo *addrs;
376
377 if (options.canonicalize_hostname == SSH_CANONICALISE_NO)
378 return NULL;
379
380 /*
381 * Don't attempt to canonicalize names that will be interpreted by
382 * a proxy unless the user specifically requests so.
383 */
384 direct = option_clear_or_none(options.proxy_command) &&
385 options.jump_host == NULL;
386 if (!direct &&
387 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
388 return NULL;
389
390 /* Try numeric hostnames first */
391 if ((addrs = resolve_addr(*hostp, port,
392 newname, sizeof(newname))) != NULL) {
393 debug2("%s: hostname %.100s is address", __func__, *hostp);
394 if (strcasecmp(*hostp, newname) != 0) {
395 debug2("%s: canonicalised address \"%s\" => \"%s\"",
396 __func__, *hostp, newname);
397 free(*hostp);
398 *hostp = xstrdup(newname);
399 }
400 return addrs;
401 }
402
403 /* If domain name is anchored, then resolve it now */
404 if ((*hostp)[strlen(*hostp) - 1] == '.') {
405 debug3("%s: name is fully qualified", __func__);
406 fullhost = xstrdup(*hostp);
407 if ((addrs = resolve_host(fullhost, port, 0,
408 newname, sizeof(newname))) != NULL)
409 goto found;
410 free(fullhost);
411 goto notfound;
412 }
413
414 /* Don't apply canonicalization to sufficiently-qualified hostnames */
415 ndots = 0;
416 for (cp = *hostp; *cp != '\0'; cp++) {
417 if (*cp == '.')
418 ndots++;
419 }
420 if (ndots > options.canonicalize_max_dots) {
421 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)",
422 __func__, *hostp, options.canonicalize_max_dots);
423 return NULL;
424 }
425 /* Attempt each supplied suffix */
426 for (i = 0; i < options.num_canonical_domains; i++) {
427 *newname = '\0';
428 xasprintf(&fullhost, "%s.%s.", *hostp,
429 options.canonical_domains[i]);
430 debug3("%s: attempting \"%s\" => \"%s\"", __func__,
431 *hostp, fullhost);
432 if ((addrs = resolve_host(fullhost, port, 0,
433 newname, sizeof(newname))) == NULL) {
434 free(fullhost);
435 continue;
436 }
437 found:
438 /* Remove trailing '.' */
439 fullhost[strlen(fullhost) - 1] = '\0';
440 /* Follow CNAME if requested */
441 if (!check_follow_cname(direct, &fullhost, newname)) {
442 debug("Canonicalized hostname \"%s\" => \"%s\"",
443 *hostp, fullhost);
444 }
445 free(*hostp);
446 *hostp = fullhost;
447 return addrs;
448 }
449 notfound:
450 if (!options.canonicalize_fallback_local)
451 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp);
452 debug2("%s: host %s not found in any suffix", __func__, *hostp);
453 return NULL;
454 }
455
456 /*
457 * Read per-user configuration file. Ignore the system wide config
458 * file if the user specifies a config file on the command line.
459 */
460 static void
process_config_files(const char * host_arg,struct passwd * pw,int post_canon)461 process_config_files(const char *host_arg, struct passwd *pw, int post_canon)
462 {
463 char buf[PATH_MAX];
464 int r;
465
466 if (config != NULL) {
467 if (strcasecmp(config, "none") != 0 &&
468 !read_config_file(config, pw, host, host_arg, &options,
469 SSHCONF_USERCONF | (post_canon ? SSHCONF_POSTCANON : 0)))
470 fatal("Can't open user config file %.100s: "
471 "%.100s", config, strerror(errno));
472 } else {
473 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
474 _PATH_SSH_USER_CONFFILE);
475 if (r > 0 && (size_t)r < sizeof(buf))
476 (void)read_config_file(buf, pw, host, host_arg,
477 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF |
478 (post_canon ? SSHCONF_POSTCANON : 0));
479
480 /* Read systemwide configuration file after user config. */
481 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw,
482 host, host_arg, &options,
483 post_canon ? SSHCONF_POSTCANON : 0);
484 }
485 }
486
487 /* Rewrite the port number in an addrinfo list of addresses */
488 static void
set_addrinfo_port(struct addrinfo * addrs,int port)489 set_addrinfo_port(struct addrinfo *addrs, int port)
490 {
491 struct addrinfo *addr;
492
493 for (addr = addrs; addr != NULL; addr = addr->ai_next) {
494 switch (addr->ai_family) {
495 case AF_INET:
496 ((struct sockaddr_in *)addr->ai_addr)->
497 sin_port = htons(port);
498 break;
499 case AF_INET6:
500 ((struct sockaddr_in6 *)addr->ai_addr)->
501 sin6_port = htons(port);
502 break;
503 }
504 }
505 }
506
507 /*
508 * Main program for the ssh client.
509 */
510 int
main(int ac,char ** av)511 main(int ac, char **av)
512 {
513 struct ssh *ssh = NULL;
514 int i, r, opt, exit_status, use_syslog, direct, config_test = 0;
515 char *p, *cp, *line, *argv0, buf[PATH_MAX], *host_arg, *logfile;
516 char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
517 char cname[NI_MAXHOST], uidstr[32], *conn_hash_hex;
518 struct stat st;
519 struct passwd *pw;
520 int timeout_ms;
521 extern int optind, optreset;
522 extern char *optarg;
523 struct Forward fwd;
524 struct addrinfo *addrs = NULL;
525 struct ssh_digest_ctx *md;
526 u_char conn_hash[SSH_DIGEST_MAX_LENGTH];
527
528 ssh_malloc_init(); /* must be called before any mallocs */
529 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
530 sanitise_stdfd();
531
532 __progname = ssh_get_progname(av[0]);
533
534 #ifndef HAVE_SETPROCTITLE
535 /* Prepare for later setproctitle emulation */
536 /* Save argv so it isn't clobbered by setproctitle() emulation */
537 saved_av = xcalloc(ac + 1, sizeof(*saved_av));
538 for (i = 0; i < ac; i++)
539 saved_av[i] = xstrdup(av[i]);
540 saved_av[i] = NULL;
541 compat_init_setproctitle(ac, av);
542 av = saved_av;
543 #endif
544
545 /*
546 * Discard other fds that are hanging around. These can cause problem
547 * with backgrounded ssh processes started by ControlPersist.
548 */
549 closefrom(STDERR_FILENO + 1);
550
551 /*
552 * Save the original real uid. It will be needed later (uid-swapping
553 * may clobber the real uid).
554 */
555 original_real_uid = getuid();
556 original_effective_uid = geteuid();
557
558 /*
559 * Use uid-swapping to give up root privileges for the duration of
560 * option processing. We will re-instantiate the rights when we are
561 * ready to create the privileged port, and will permanently drop
562 * them when the port has been created (actually, when the connection
563 * has been made, as we may need to create the port several times).
564 */
565 PRIV_END;
566
567 #ifdef HAVE_SETRLIMIT
568 /* If we are installed setuid root be careful to not drop core. */
569 if (original_real_uid != original_effective_uid) {
570 struct rlimit rlim;
571 rlim.rlim_cur = rlim.rlim_max = 0;
572 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
573 fatal("setrlimit failed: %.100s", strerror(errno));
574 }
575 #endif
576 /* Get user data. */
577 pw = getpwuid(original_real_uid);
578 if (!pw) {
579 logit("No user exists for uid %lu", (u_long)original_real_uid);
580 exit(255);
581 }
582 /* Take a copy of the returned structure. */
583 pw = pwcopy(pw);
584
585 /*
586 * Set our umask to something reasonable, as some files are created
587 * with the default umask. This will make them world-readable but
588 * writable only by the owner, which is ok for all files for which we
589 * don't set the modes explicitly.
590 */
591 umask(022);
592
593 msetlocale();
594
595 /*
596 * Initialize option structure to indicate that no values have been
597 * set.
598 */
599 initialize_options(&options);
600
601 /* Parse command-line arguments. */
602 host = NULL;
603 use_syslog = 0;
604 logfile = NULL;
605 argv0 = av[0];
606
607 again:
608 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
609 "ACD:E:F:GI:J:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) {
610 switch (opt) {
611 case '1':
612 options.protocol = SSH_PROTO_1;
613 break;
614 case '2':
615 options.protocol = SSH_PROTO_2;
616 break;
617 case '4':
618 options.address_family = AF_INET;
619 break;
620 case '6':
621 options.address_family = AF_INET6;
622 break;
623 case 'n':
624 stdin_null_flag = 1;
625 break;
626 case 'f':
627 fork_after_authentication_flag = 1;
628 stdin_null_flag = 1;
629 break;
630 case 'x':
631 options.forward_x11 = 0;
632 break;
633 case 'X':
634 options.forward_x11 = 1;
635 break;
636 case 'y':
637 use_syslog = 1;
638 break;
639 case 'E':
640 logfile = optarg;
641 break;
642 case 'G':
643 config_test = 1;
644 break;
645 case 'Y':
646 options.forward_x11 = 1;
647 options.forward_x11_trusted = 1;
648 break;
649 case 'g':
650 options.fwd_opts.gateway_ports = 1;
651 break;
652 case 'O':
653 if (options.stdio_forward_host != NULL)
654 fatal("Cannot specify multiplexing "
655 "command with -W");
656 else if (muxclient_command != 0)
657 fatal("Multiplexing command already specified");
658 if (strcmp(optarg, "check") == 0)
659 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
660 else if (strcmp(optarg, "forward") == 0)
661 muxclient_command = SSHMUX_COMMAND_FORWARD;
662 else if (strcmp(optarg, "exit") == 0)
663 muxclient_command = SSHMUX_COMMAND_TERMINATE;
664 else if (strcmp(optarg, "stop") == 0)
665 muxclient_command = SSHMUX_COMMAND_STOP;
666 else if (strcmp(optarg, "cancel") == 0)
667 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD;
668 else if (strcmp(optarg, "proxy") == 0)
669 muxclient_command = SSHMUX_COMMAND_PROXY;
670 else
671 fatal("Invalid multiplex command.");
672 break;
673 case 'P': /* deprecated */
674 options.use_privileged_port = 0;
675 break;
676 case 'Q':
677 cp = NULL;
678 if (strcmp(optarg, "cipher") == 0)
679 cp = cipher_alg_list('\n', 0);
680 else if (strcmp(optarg, "cipher-auth") == 0)
681 cp = cipher_alg_list('\n', 1);
682 else if (strcmp(optarg, "mac") == 0)
683 cp = mac_alg_list('\n');
684 else if (strcmp(optarg, "kex") == 0)
685 cp = kex_alg_list('\n');
686 else if (strcmp(optarg, "key") == 0)
687 cp = sshkey_alg_list(0, 0, 0, '\n');
688 else if (strcmp(optarg, "key-cert") == 0)
689 cp = sshkey_alg_list(1, 0, 0, '\n');
690 else if (strcmp(optarg, "key-plain") == 0)
691 cp = sshkey_alg_list(0, 1, 0, '\n');
692 else if (strcmp(optarg, "protocol-version") == 0) {
693 #ifdef WITH_SSH1
694 cp = xstrdup("1\n2");
695 #else
696 cp = xstrdup("2");
697 #endif
698 }
699 if (cp == NULL)
700 fatal("Unsupported query \"%s\"", optarg);
701 printf("%s\n", cp);
702 free(cp);
703 exit(0);
704 break;
705 case 'a':
706 options.forward_agent = 0;
707 break;
708 case 'A':
709 options.forward_agent = 1;
710 break;
711 case 'k':
712 options.gss_deleg_creds = 0;
713 break;
714 case 'K':
715 options.gss_authentication = 1;
716 options.gss_deleg_creds = 1;
717 break;
718 case 'i':
719 p = tilde_expand_filename(optarg, original_real_uid);
720 if (stat(p, &st) < 0)
721 fprintf(stderr, "Warning: Identity file %s "
722 "not accessible: %s.\n", p,
723 strerror(errno));
724 else
725 add_identity_file(&options, NULL, p, 1);
726 free(p);
727 break;
728 case 'I':
729 #ifdef ENABLE_PKCS11
730 free(options.pkcs11_provider);
731 options.pkcs11_provider = xstrdup(optarg);
732 #else
733 fprintf(stderr, "no support for PKCS#11.\n");
734 #endif
735 break;
736 case 'J':
737 if (options.jump_host != NULL)
738 fatal("Only a single -J option permitted");
739 if (options.proxy_command != NULL)
740 fatal("Cannot specify -J with ProxyCommand");
741 if (parse_jump(optarg, &options, 1) == -1)
742 fatal("Invalid -J argument");
743 options.proxy_command = xstrdup("none");
744 break;
745 case 't':
746 if (options.request_tty == REQUEST_TTY_YES)
747 options.request_tty = REQUEST_TTY_FORCE;
748 else
749 options.request_tty = REQUEST_TTY_YES;
750 break;
751 case 'v':
752 if (debug_flag == 0) {
753 debug_flag = 1;
754 options.log_level = SYSLOG_LEVEL_DEBUG1;
755 } else {
756 if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
757 debug_flag++;
758 options.log_level++;
759 }
760 }
761 break;
762 case 'V':
763 fprintf(stderr, "%s, %s\n",
764 SSH_RELEASE,
765 #ifdef WITH_OPENSSL
766 SSLeay_version(SSLEAY_VERSION)
767 #else
768 "without OpenSSL"
769 #endif
770 );
771 if (opt == 'V')
772 exit(0);
773 break;
774 case 'w':
775 if (options.tun_open == -1)
776 options.tun_open = SSH_TUNMODE_DEFAULT;
777 options.tun_local = a2tun(optarg, &options.tun_remote);
778 if (options.tun_local == SSH_TUNID_ERR) {
779 fprintf(stderr,
780 "Bad tun device '%s'\n", optarg);
781 exit(255);
782 }
783 break;
784 case 'W':
785 if (options.stdio_forward_host != NULL)
786 fatal("stdio forward already specified");
787 if (muxclient_command != 0)
788 fatal("Cannot specify stdio forward with -O");
789 if (parse_forward(&fwd, optarg, 1, 0)) {
790 options.stdio_forward_host = fwd.listen_host;
791 options.stdio_forward_port = fwd.listen_port;
792 free(fwd.connect_host);
793 } else {
794 fprintf(stderr,
795 "Bad stdio forwarding specification '%s'\n",
796 optarg);
797 exit(255);
798 }
799 options.request_tty = REQUEST_TTY_NO;
800 no_shell_flag = 1;
801 break;
802 case 'q':
803 options.log_level = SYSLOG_LEVEL_QUIET;
804 break;
805 case 'e':
806 if (optarg[0] == '^' && optarg[2] == 0 &&
807 (u_char) optarg[1] >= 64 &&
808 (u_char) optarg[1] < 128)
809 options.escape_char = (u_char) optarg[1] & 31;
810 else if (strlen(optarg) == 1)
811 options.escape_char = (u_char) optarg[0];
812 else if (strcmp(optarg, "none") == 0)
813 options.escape_char = SSH_ESCAPECHAR_NONE;
814 else {
815 fprintf(stderr, "Bad escape character '%s'.\n",
816 optarg);
817 exit(255);
818 }
819 break;
820 case 'c':
821 if (ciphers_valid(*optarg == '+' ?
822 optarg + 1 : optarg)) {
823 /* SSH2 only */
824 free(options.ciphers);
825 options.ciphers = xstrdup(optarg);
826 options.cipher = SSH_CIPHER_INVALID;
827 break;
828 }
829 /* SSH1 only */
830 options.cipher = cipher_number(optarg);
831 if (options.cipher == -1) {
832 fprintf(stderr, "Unknown cipher type '%s'\n",
833 optarg);
834 exit(255);
835 }
836 if (options.cipher == SSH_CIPHER_3DES)
837 options.ciphers = xstrdup("3des-cbc");
838 else if (options.cipher == SSH_CIPHER_BLOWFISH)
839 options.ciphers = xstrdup("blowfish-cbc");
840 else
841 options.ciphers = xstrdup(KEX_CLIENT_ENCRYPT);
842 break;
843 case 'm':
844 if (mac_valid(optarg)) {
845 free(options.macs);
846 options.macs = xstrdup(optarg);
847 } else {
848 fprintf(stderr, "Unknown mac type '%s'\n",
849 optarg);
850 exit(255);
851 }
852 break;
853 case 'M':
854 if (options.control_master == SSHCTL_MASTER_YES)
855 options.control_master = SSHCTL_MASTER_ASK;
856 else
857 options.control_master = SSHCTL_MASTER_YES;
858 break;
859 case 'p':
860 options.port = a2port(optarg);
861 if (options.port <= 0) {
862 fprintf(stderr, "Bad port '%s'\n", optarg);
863 exit(255);
864 }
865 break;
866 case 'l':
867 options.user = optarg;
868 break;
869
870 case 'L':
871 if (parse_forward(&fwd, optarg, 0, 0))
872 add_local_forward(&options, &fwd);
873 else {
874 fprintf(stderr,
875 "Bad local forwarding specification '%s'\n",
876 optarg);
877 exit(255);
878 }
879 break;
880
881 case 'R':
882 if (parse_forward(&fwd, optarg, 0, 1)) {
883 add_remote_forward(&options, &fwd);
884 } else {
885 fprintf(stderr,
886 "Bad remote forwarding specification "
887 "'%s'\n", optarg);
888 exit(255);
889 }
890 break;
891
892 case 'D':
893 if (parse_forward(&fwd, optarg, 1, 0)) {
894 add_local_forward(&options, &fwd);
895 } else {
896 fprintf(stderr,
897 "Bad dynamic forwarding specification "
898 "'%s'\n", optarg);
899 exit(255);
900 }
901 break;
902
903 case 'C':
904 options.compression = 1;
905 break;
906 case 'N':
907 no_shell_flag = 1;
908 options.request_tty = REQUEST_TTY_NO;
909 break;
910 case 'T':
911 options.request_tty = REQUEST_TTY_NO;
912 break;
913 case 'o':
914 line = xstrdup(optarg);
915 if (process_config_line(&options, pw,
916 host ? host : "", host ? host : "", line,
917 "command-line", 0, NULL, SSHCONF_USERCONF) != 0)
918 exit(255);
919 free(line);
920 break;
921 case 's':
922 subsystem_flag = 1;
923 break;
924 case 'S':
925 free(options.control_path);
926 options.control_path = xstrdup(optarg);
927 break;
928 case 'b':
929 options.bind_address = optarg;
930 break;
931 case 'F':
932 config = optarg;
933 break;
934 default:
935 usage();
936 }
937 }
938
939 ac -= optind;
940 av += optind;
941
942 if (ac > 0 && !host) {
943 if (strrchr(*av, '@')) {
944 p = xstrdup(*av);
945 cp = strrchr(p, '@');
946 if (cp == NULL || cp == p)
947 usage();
948 options.user = p;
949 *cp = '\0';
950 host = xstrdup(++cp);
951 } else
952 host = xstrdup(*av);
953 if (ac > 1) {
954 optind = optreset = 1;
955 goto again;
956 }
957 ac--, av++;
958 }
959
960 /* Check that we got a host name. */
961 if (!host)
962 usage();
963
964 host_arg = xstrdup(host);
965
966 #ifdef WITH_OPENSSL
967 OpenSSL_add_all_algorithms();
968 ERR_load_crypto_strings();
969 #endif
970
971 /* Initialize the command to execute on remote host. */
972 buffer_init(&command);
973
974 /*
975 * Save the command to execute on the remote host in a buffer. There
976 * is no limit on the length of the command, except by the maximum
977 * packet size. Also sets the tty flag if there is no command.
978 */
979 if (!ac) {
980 /* No command specified - execute shell on a tty. */
981 if (subsystem_flag) {
982 fprintf(stderr,
983 "You must specify a subsystem to invoke.\n");
984 usage();
985 }
986 } else {
987 /* A command has been specified. Store it into the buffer. */
988 for (i = 0; i < ac; i++) {
989 if (i)
990 buffer_append(&command, " ", 1);
991 buffer_append(&command, av[i], strlen(av[i]));
992 }
993 }
994
995 /* Cannot fork to background if no command. */
996 if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
997 !no_shell_flag)
998 fatal("Cannot fork into background without a command "
999 "to execute.");
1000
1001 /*
1002 * Initialize "log" output. Since we are the client all output
1003 * goes to stderr unless otherwise specified by -y or -E.
1004 */
1005 if (use_syslog && logfile != NULL)
1006 fatal("Can't specify both -y and -E");
1007 if (logfile != NULL)
1008 log_redirect_stderr_to(logfile);
1009 log_init(argv0,
1010 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
1011 SYSLOG_FACILITY_USER, !use_syslog);
1012
1013 if (debug_flag)
1014 logit("%s, %s", SSH_RELEASE,
1015 #ifdef WITH_OPENSSL
1016 SSLeay_version(SSLEAY_VERSION)
1017 #else
1018 "without OpenSSL"
1019 #endif
1020 );
1021
1022 /* Parse the configuration files */
1023 process_config_files(host_arg, pw, 0);
1024
1025 /* Hostname canonicalisation needs a few options filled. */
1026 fill_default_options_for_canonicalization(&options);
1027
1028 /* If the user has replaced the hostname then take it into use now */
1029 if (options.hostname != NULL) {
1030 /* NB. Please keep in sync with readconf.c:match_cfg_line() */
1031 cp = percent_expand(options.hostname,
1032 "h", host, (char *)NULL);
1033 free(host);
1034 host = cp;
1035 free(options.hostname);
1036 options.hostname = xstrdup(host);
1037 }
1038
1039 /* If canonicalization requested then try to apply it */
1040 lowercase(host);
1041 if (options.canonicalize_hostname != SSH_CANONICALISE_NO)
1042 addrs = resolve_canonicalize(&host, options.port);
1043
1044 /*
1045 * If CanonicalizePermittedCNAMEs have been specified but
1046 * other canonicalization did not happen (by not being requested
1047 * or by failing with fallback) then the hostname may still be changed
1048 * as a result of CNAME following.
1049 *
1050 * Try to resolve the bare hostname name using the system resolver's
1051 * usual search rules and then apply the CNAME follow rules.
1052 *
1053 * Skip the lookup if a ProxyCommand is being used unless the user
1054 * has specifically requested canonicalisation for this case via
1055 * CanonicalizeHostname=always
1056 */
1057 direct = option_clear_or_none(options.proxy_command) &&
1058 options.jump_host == NULL;
1059 if (addrs == NULL && options.num_permitted_cnames != 0 && (direct ||
1060 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) {
1061 if ((addrs = resolve_host(host, options.port,
1062 option_clear_or_none(options.proxy_command),
1063 cname, sizeof(cname))) == NULL) {
1064 /* Don't fatal proxied host names not in the DNS */
1065 if (option_clear_or_none(options.proxy_command))
1066 cleanup_exit(255); /* logged in resolve_host */
1067 } else
1068 check_follow_cname(direct, &host, cname);
1069 }
1070
1071 /*
1072 * If canonicalisation is enabled then re-parse the configuration
1073 * files as new stanzas may match.
1074 */
1075 if (options.canonicalize_hostname != 0) {
1076 debug("Re-reading configuration after hostname "
1077 "canonicalisation");
1078 free(options.hostname);
1079 options.hostname = xstrdup(host);
1080 process_config_files(host_arg, pw, 1);
1081 /*
1082 * Address resolution happens early with canonicalisation
1083 * enabled and the port number may have changed since, so
1084 * reset it in address list
1085 */
1086 if (addrs != NULL && options.port > 0)
1087 set_addrinfo_port(addrs, options.port);
1088 }
1089
1090 /* Fill configuration defaults. */
1091 fill_default_options(&options);
1092
1093 /*
1094 * If ProxyJump option specified, then construct a ProxyCommand now.
1095 */
1096 if (options.jump_host != NULL) {
1097 char port_s[8];
1098
1099 /* Consistency check */
1100 if (options.proxy_command != NULL)
1101 fatal("inconsistent options: ProxyCommand+ProxyJump");
1102 /* Never use FD passing for ProxyJump */
1103 options.proxy_use_fdpass = 0;
1104 snprintf(port_s, sizeof(port_s), "%d", options.jump_port);
1105 xasprintf(&options.proxy_command,
1106 "ssh%s%s%s%s%s%s%s%s%s%.*s -W '[%%h]:%%p' %s",
1107 /* Optional "-l user" argument if jump_user set */
1108 options.jump_user == NULL ? "" : " -l ",
1109 options.jump_user == NULL ? "" : options.jump_user,
1110 /* Optional "-p port" argument if jump_port set */
1111 options.jump_port <= 0 ? "" : " -p ",
1112 options.jump_port <= 0 ? "" : port_s,
1113 /* Optional additional jump hosts ",..." */
1114 options.jump_extra == NULL ? "" : " -J ",
1115 options.jump_extra == NULL ? "" : options.jump_extra,
1116 /* Optional "-F" argumment if -F specified */
1117 config == NULL ? "" : " -F ",
1118 config == NULL ? "" : config,
1119 /* Optional "-v" arguments if -v set */
1120 debug_flag ? " -" : "",
1121 debug_flag, "vvv",
1122 /* Mandatory hostname */
1123 options.jump_host);
1124 debug("Setting implicit ProxyCommand from ProxyJump: %s",
1125 options.proxy_command);
1126 }
1127
1128 if (options.port == 0)
1129 options.port = default_ssh_port();
1130 channel_set_af(options.address_family);
1131
1132 /* Tidy and check options */
1133 if (options.host_key_alias != NULL)
1134 lowercase(options.host_key_alias);
1135 if (options.proxy_command != NULL &&
1136 strcmp(options.proxy_command, "-") == 0 &&
1137 options.proxy_use_fdpass)
1138 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible");
1139 if (options.control_persist &&
1140 options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) {
1141 debug("UpdateHostKeys=ask is incompatible with ControlPersist; "
1142 "disabling");
1143 options.update_hostkeys = 0;
1144 }
1145 if (options.connection_attempts <= 0)
1146 fatal("Invalid number of ConnectionAttempts");
1147 #ifndef HAVE_CYGWIN
1148 if (original_effective_uid != 0)
1149 options.use_privileged_port = 0;
1150 #endif
1151
1152 /* reinit */
1153 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
1154
1155 if (options.request_tty == REQUEST_TTY_YES ||
1156 options.request_tty == REQUEST_TTY_FORCE)
1157 tty_flag = 1;
1158
1159 /* Allocate a tty by default if no command specified. */
1160 if (buffer_len(&command) == 0)
1161 tty_flag = options.request_tty != REQUEST_TTY_NO;
1162
1163 /* Force no tty */
1164 if (options.request_tty == REQUEST_TTY_NO ||
1165 (muxclient_command && muxclient_command != SSHMUX_COMMAND_PROXY))
1166 tty_flag = 0;
1167 /* Do not allocate a tty if stdin is not a tty. */
1168 if ((!isatty(fileno(stdin)) || stdin_null_flag) &&
1169 options.request_tty != REQUEST_TTY_FORCE) {
1170 if (tty_flag)
1171 logit("Pseudo-terminal will not be allocated because "
1172 "stdin is not a terminal.");
1173 tty_flag = 0;
1174 }
1175
1176 seed_rng();
1177
1178 if (options.user == NULL)
1179 options.user = xstrdup(pw->pw_name);
1180
1181 if (gethostname(thishost, sizeof(thishost)) == -1)
1182 fatal("gethostname: %s", strerror(errno));
1183 strlcpy(shorthost, thishost, sizeof(shorthost));
1184 shorthost[strcspn(thishost, ".")] = '\0';
1185 snprintf(portstr, sizeof(portstr), "%d", options.port);
1186 snprintf(uidstr, sizeof(uidstr), "%d", pw->pw_uid);
1187
1188 if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL ||
1189 ssh_digest_update(md, thishost, strlen(thishost)) < 0 ||
1190 ssh_digest_update(md, host, strlen(host)) < 0 ||
1191 ssh_digest_update(md, portstr, strlen(portstr)) < 0 ||
1192 ssh_digest_update(md, options.user, strlen(options.user)) < 0 ||
1193 ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0)
1194 fatal("%s: mux digest failed", __func__);
1195 ssh_digest_free(md);
1196 conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1));
1197
1198 if (options.local_command != NULL) {
1199 debug3("expanding LocalCommand: %s", options.local_command);
1200 cp = options.local_command;
1201 options.local_command = percent_expand(cp,
1202 "C", conn_hash_hex,
1203 "L", shorthost,
1204 "d", pw->pw_dir,
1205 "h", host,
1206 "l", thishost,
1207 "n", host_arg,
1208 "p", portstr,
1209 "r", options.user,
1210 "u", pw->pw_name,
1211 (char *)NULL);
1212 debug3("expanded LocalCommand: %s", options.local_command);
1213 free(cp);
1214 }
1215
1216 if (options.control_path != NULL) {
1217 cp = tilde_expand_filename(options.control_path,
1218 original_real_uid);
1219 free(options.control_path);
1220 options.control_path = percent_expand(cp,
1221 "C", conn_hash_hex,
1222 "L", shorthost,
1223 "h", host,
1224 "l", thishost,
1225 "n", host_arg,
1226 "p", portstr,
1227 "r", options.user,
1228 "u", pw->pw_name,
1229 "i", uidstr,
1230 (char *)NULL);
1231 free(cp);
1232 }
1233 free(conn_hash_hex);
1234
1235 if (config_test) {
1236 dump_client_config(&options, host);
1237 exit(0);
1238 }
1239
1240 if (muxclient_command != 0 && options.control_path == NULL)
1241 fatal("No ControlPath specified for \"-O\" command");
1242 if (options.control_path != NULL) {
1243 int sock;
1244 if ((sock = muxclient(options.control_path)) >= 0) {
1245 packet_set_connection(sock, sock);
1246 ssh = active_state; /* XXX */
1247 enable_compat20(); /* XXX */
1248 packet_set_mux();
1249 goto skip_connect;
1250 }
1251 }
1252
1253 /*
1254 * If hostname canonicalisation was not enabled, then we may not
1255 * have yet resolved the hostname. Do so now.
1256 */
1257 if (addrs == NULL && options.proxy_command == NULL) {
1258 debug2("resolving \"%s\" port %d", host, options.port);
1259 if ((addrs = resolve_host(host, options.port, 1,
1260 cname, sizeof(cname))) == NULL)
1261 cleanup_exit(255); /* resolve_host logs the error */
1262 }
1263
1264 timeout_ms = options.connection_timeout * 1000;
1265
1266 /* Open a connection to the remote host. */
1267 if (ssh_connect(host, addrs, &hostaddr, options.port,
1268 options.address_family, options.connection_attempts,
1269 &timeout_ms, options.tcp_keep_alive,
1270 options.use_privileged_port) != 0)
1271 exit(255);
1272
1273 if (addrs != NULL)
1274 freeaddrinfo(addrs);
1275
1276 packet_set_timeout(options.server_alive_interval,
1277 options.server_alive_count_max);
1278
1279 ssh = active_state; /* XXX */
1280
1281 if (timeout_ms > 0)
1282 debug3("timeout: %d ms remain after connect", timeout_ms);
1283
1284 /*
1285 * If we successfully made the connection, load the host private key
1286 * in case we will need it later for combined rsa-rhosts
1287 * authentication. This must be done before releasing extra
1288 * privileges, because the file is only readable by root.
1289 * If we cannot access the private keys, load the public keys
1290 * instead and try to execute the ssh-keysign helper instead.
1291 */
1292 sensitive_data.nkeys = 0;
1293 sensitive_data.keys = NULL;
1294 sensitive_data.external_keysign = 0;
1295 if (options.rhosts_rsa_authentication ||
1296 options.hostbased_authentication) {
1297 sensitive_data.nkeys = 9;
1298 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
1299 sizeof(Key));
1300 for (i = 0; i < sensitive_data.nkeys; i++)
1301 sensitive_data.keys[i] = NULL;
1302
1303 PRIV_START;
1304 #if WITH_SSH1
1305 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
1306 _PATH_HOST_KEY_FILE, "", NULL, NULL);
1307 #endif
1308 #ifdef OPENSSL_HAS_ECC
1309 sensitive_data.keys[1] = key_load_private_cert(KEY_ECDSA,
1310 _PATH_HOST_ECDSA_KEY_FILE, "", NULL);
1311 #endif
1312 sensitive_data.keys[2] = key_load_private_cert(KEY_ED25519,
1313 _PATH_HOST_ED25519_KEY_FILE, "", NULL);
1314 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA,
1315 _PATH_HOST_RSA_KEY_FILE, "", NULL);
1316 sensitive_data.keys[4] = key_load_private_cert(KEY_DSA,
1317 _PATH_HOST_DSA_KEY_FILE, "", NULL);
1318 #ifdef OPENSSL_HAS_ECC
1319 sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA,
1320 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL);
1321 #endif
1322 sensitive_data.keys[6] = key_load_private_type(KEY_ED25519,
1323 _PATH_HOST_ED25519_KEY_FILE, "", NULL, NULL);
1324 sensitive_data.keys[7] = key_load_private_type(KEY_RSA,
1325 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
1326 sensitive_data.keys[8] = key_load_private_type(KEY_DSA,
1327 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
1328 PRIV_END;
1329
1330 if (options.hostbased_authentication == 1 &&
1331 sensitive_data.keys[0] == NULL &&
1332 sensitive_data.keys[5] == NULL &&
1333 sensitive_data.keys[6] == NULL &&
1334 sensitive_data.keys[7] == NULL &&
1335 sensitive_data.keys[8] == NULL) {
1336 #ifdef OPENSSL_HAS_ECC
1337 sensitive_data.keys[1] = key_load_cert(
1338 _PATH_HOST_ECDSA_KEY_FILE);
1339 #endif
1340 sensitive_data.keys[2] = key_load_cert(
1341 _PATH_HOST_ED25519_KEY_FILE);
1342 sensitive_data.keys[3] = key_load_cert(
1343 _PATH_HOST_RSA_KEY_FILE);
1344 sensitive_data.keys[4] = key_load_cert(
1345 _PATH_HOST_DSA_KEY_FILE);
1346 #ifdef OPENSSL_HAS_ECC
1347 sensitive_data.keys[5] = key_load_public(
1348 _PATH_HOST_ECDSA_KEY_FILE, NULL);
1349 #endif
1350 sensitive_data.keys[6] = key_load_public(
1351 _PATH_HOST_ED25519_KEY_FILE, NULL);
1352 sensitive_data.keys[7] = key_load_public(
1353 _PATH_HOST_RSA_KEY_FILE, NULL);
1354 sensitive_data.keys[8] = key_load_public(
1355 _PATH_HOST_DSA_KEY_FILE, NULL);
1356 sensitive_data.external_keysign = 1;
1357 }
1358 }
1359 /*
1360 * Get rid of any extra privileges that we may have. We will no
1361 * longer need them. Also, extra privileges could make it very hard
1362 * to read identity files and other non-world-readable files from the
1363 * user's home directory if it happens to be on a NFS volume where
1364 * root is mapped to nobody.
1365 */
1366 if (original_effective_uid == 0) {
1367 PRIV_START;
1368 permanently_set_uid(pw);
1369 }
1370
1371 /*
1372 * Now that we are back to our own permissions, create ~/.ssh
1373 * directory if it doesn't already exist.
1374 */
1375 if (config == NULL) {
1376 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir,
1377 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
1378 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) {
1379 #ifdef WITH_SELINUX
1380 ssh_selinux_setfscreatecon(buf);
1381 #endif
1382 if (mkdir(buf, 0700) < 0)
1383 error("Could not create directory '%.200s'.",
1384 buf);
1385 #ifdef WITH_SELINUX
1386 ssh_selinux_setfscreatecon(NULL);
1387 #endif
1388 }
1389 }
1390 /* load options.identity_files */
1391 load_public_identity_files();
1392
1393 /* optionally set the SSH_AUTHSOCKET_ENV_NAME varibale */
1394 if (options.identity_agent &&
1395 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) {
1396 if (strcmp(options.identity_agent, "none") == 0) {
1397 unsetenv(SSH_AUTHSOCKET_ENV_NAME);
1398 } else {
1399 p = tilde_expand_filename(options.identity_agent,
1400 original_real_uid);
1401 cp = percent_expand(p, "d", pw->pw_dir,
1402 "u", pw->pw_name, "l", thishost, "h", host,
1403 "r", options.user, (char *)NULL);
1404 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1);
1405 free(cp);
1406 free(p);
1407 }
1408 }
1409
1410 /* Expand ~ in known host file names. */
1411 tilde_expand_paths(options.system_hostfiles,
1412 options.num_system_hostfiles);
1413 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles);
1414
1415 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
1416 signal(SIGCHLD, main_sigchld_handler);
1417
1418 /* Log into the remote system. Never returns if the login fails. */
1419 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
1420 options.port, pw, timeout_ms);
1421
1422 if (packet_connection_is_on_socket()) {
1423 verbose("Authenticated to %s ([%s]:%d).", host,
1424 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1425 } else {
1426 verbose("Authenticated to %s (via proxy).", host);
1427 }
1428
1429 /* We no longer need the private host keys. Clear them now. */
1430 if (sensitive_data.nkeys != 0) {
1431 for (i = 0; i < sensitive_data.nkeys; i++) {
1432 if (sensitive_data.keys[i] != NULL) {
1433 /* Destroys contents safely */
1434 debug3("clear hostkey %d", i);
1435 key_free(sensitive_data.keys[i]);
1436 sensitive_data.keys[i] = NULL;
1437 }
1438 }
1439 free(sensitive_data.keys);
1440 }
1441 for (i = 0; i < options.num_identity_files; i++) {
1442 free(options.identity_files[i]);
1443 options.identity_files[i] = NULL;
1444 if (options.identity_keys[i]) {
1445 key_free(options.identity_keys[i]);
1446 options.identity_keys[i] = NULL;
1447 }
1448 }
1449 for (i = 0; i < options.num_certificate_files; i++) {
1450 free(options.certificate_files[i]);
1451 options.certificate_files[i] = NULL;
1452 }
1453
1454 skip_connect:
1455 exit_status = compat20 ? ssh_session2() : ssh_session();
1456 packet_close();
1457
1458 if (options.control_path != NULL && muxserver_sock != -1)
1459 unlink(options.control_path);
1460
1461 /* Kill ProxyCommand if it is running. */
1462 ssh_kill_proxy_command();
1463
1464 return exit_status;
1465 }
1466
1467 static void
control_persist_detach(void)1468 control_persist_detach(void)
1469 {
1470 pid_t pid;
1471 int devnull, keep_stderr;
1472
1473 debug("%s: backgrounding master process", __func__);
1474
1475 /*
1476 * master (current process) into the background, and make the
1477 * foreground process a client of the backgrounded master.
1478 */
1479 switch ((pid = fork())) {
1480 case -1:
1481 fatal("%s: fork: %s", __func__, strerror(errno));
1482 case 0:
1483 /* Child: master process continues mainloop */
1484 break;
1485 default:
1486 /* Parent: set up mux slave to connect to backgrounded master */
1487 debug2("%s: background process is %ld", __func__, (long)pid);
1488 stdin_null_flag = ostdin_null_flag;
1489 options.request_tty = orequest_tty;
1490 tty_flag = otty_flag;
1491 close(muxserver_sock);
1492 muxserver_sock = -1;
1493 options.control_master = SSHCTL_MASTER_NO;
1494 muxclient(options.control_path);
1495 /* muxclient() doesn't return on success. */
1496 fatal("Failed to connect to new control master");
1497 }
1498 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
1499 error("%s: open(\"/dev/null\"): %s", __func__,
1500 strerror(errno));
1501 } else {
1502 keep_stderr = log_is_on_stderr() && debug_flag;
1503 if (dup2(devnull, STDIN_FILENO) == -1 ||
1504 dup2(devnull, STDOUT_FILENO) == -1 ||
1505 (!keep_stderr && dup2(devnull, STDERR_FILENO) == -1))
1506 error("%s: dup2: %s", __func__, strerror(errno));
1507 if (devnull > STDERR_FILENO)
1508 close(devnull);
1509 }
1510 daemon(1, 1);
1511 setproctitle("%s [mux]", options.control_path);
1512 }
1513
1514 /* Do fork() after authentication. Used by "ssh -f" */
1515 static void
fork_postauth(void)1516 fork_postauth(void)
1517 {
1518 if (need_controlpersist_detach)
1519 control_persist_detach();
1520 debug("forking to background");
1521 fork_after_authentication_flag = 0;
1522 if (daemon(1, 1) < 0)
1523 fatal("daemon() failed: %.200s", strerror(errno));
1524 }
1525
1526 /* Callback for remote forward global requests */
1527 static void
ssh_confirm_remote_forward(int type,u_int32_t seq,void * ctxt)1528 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
1529 {
1530 struct Forward *rfwd = (struct Forward *)ctxt;
1531
1532 /* XXX verbose() on failure? */
1533 debug("remote forward %s for: listen %s%s%d, connect %s:%d",
1534 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1535 rfwd->listen_path ? rfwd->listen_path :
1536 rfwd->listen_host ? rfwd->listen_host : "",
1537 (rfwd->listen_path || rfwd->listen_host) ? ":" : "",
1538 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path :
1539 rfwd->connect_host, rfwd->connect_port);
1540 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) {
1541 if (type == SSH2_MSG_REQUEST_SUCCESS) {
1542 rfwd->allocated_port = packet_get_int();
1543 logit("Allocated port %u for remote forward to %s:%d",
1544 rfwd->allocated_port,
1545 rfwd->connect_host, rfwd->connect_port);
1546 channel_update_permitted_opens(rfwd->handle,
1547 rfwd->allocated_port);
1548 } else {
1549 channel_update_permitted_opens(rfwd->handle, -1);
1550 }
1551 }
1552
1553 if (type == SSH2_MSG_REQUEST_FAILURE) {
1554 if (options.exit_on_forward_failure) {
1555 if (rfwd->listen_path != NULL)
1556 fatal("Error: remote port forwarding failed "
1557 "for listen path %s", rfwd->listen_path);
1558 else
1559 fatal("Error: remote port forwarding failed "
1560 "for listen port %d", rfwd->listen_port);
1561 } else {
1562 if (rfwd->listen_path != NULL)
1563 logit("Warning: remote port forwarding failed "
1564 "for listen path %s", rfwd->listen_path);
1565 else
1566 logit("Warning: remote port forwarding failed "
1567 "for listen port %d", rfwd->listen_port);
1568 }
1569 }
1570 if (++remote_forward_confirms_received == options.num_remote_forwards) {
1571 debug("All remote forwarding requests processed");
1572 if (fork_after_authentication_flag)
1573 fork_postauth();
1574 }
1575 }
1576
1577 static void
client_cleanup_stdio_fwd(int id,void * arg)1578 client_cleanup_stdio_fwd(int id, void *arg)
1579 {
1580 debug("stdio forwarding: done");
1581 cleanup_exit(0);
1582 }
1583
1584 static void
ssh_stdio_confirm(int id,int success,void * arg)1585 ssh_stdio_confirm(int id, int success, void *arg)
1586 {
1587 if (!success)
1588 fatal("stdio forwarding failed");
1589 }
1590
1591 static void
ssh_init_stdio_forwarding(void)1592 ssh_init_stdio_forwarding(void)
1593 {
1594 Channel *c;
1595 int in, out;
1596
1597 if (options.stdio_forward_host == NULL)
1598 return;
1599 if (!compat20)
1600 fatal("stdio forwarding require Protocol 2");
1601
1602 debug3("%s: %s:%d", __func__, options.stdio_forward_host,
1603 options.stdio_forward_port);
1604
1605 if ((in = dup(STDIN_FILENO)) < 0 ||
1606 (out = dup(STDOUT_FILENO)) < 0)
1607 fatal("channel_connect_stdio_fwd: dup() in/out failed");
1608 if ((c = channel_connect_stdio_fwd(options.stdio_forward_host,
1609 options.stdio_forward_port, in, out)) == NULL)
1610 fatal("%s: channel_connect_stdio_fwd failed", __func__);
1611 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0);
1612 channel_register_open_confirm(c->self, ssh_stdio_confirm, NULL);
1613 }
1614
1615 static void
ssh_init_forwarding(void)1616 ssh_init_forwarding(void)
1617 {
1618 int success = 0;
1619 int i;
1620
1621 /* Initiate local TCP/IP port forwardings. */
1622 for (i = 0; i < options.num_local_forwards; i++) {
1623 debug("Local connections to %.200s:%d forwarded to remote "
1624 "address %.200s:%d",
1625 (options.local_forwards[i].listen_path != NULL) ?
1626 options.local_forwards[i].listen_path :
1627 (options.local_forwards[i].listen_host == NULL) ?
1628 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1629 options.local_forwards[i].listen_host,
1630 options.local_forwards[i].listen_port,
1631 (options.local_forwards[i].connect_path != NULL) ?
1632 options.local_forwards[i].connect_path :
1633 options.local_forwards[i].connect_host,
1634 options.local_forwards[i].connect_port);
1635 success += channel_setup_local_fwd_listener(
1636 &options.local_forwards[i], &options.fwd_opts);
1637 }
1638 if (i > 0 && success != i && options.exit_on_forward_failure)
1639 fatal("Could not request local forwarding.");
1640 if (i > 0 && success == 0)
1641 error("Could not request local forwarding.");
1642
1643 /* Initiate remote TCP/IP port forwardings. */
1644 for (i = 0; i < options.num_remote_forwards; i++) {
1645 debug("Remote connections from %.200s:%d forwarded to "
1646 "local address %.200s:%d",
1647 (options.remote_forwards[i].listen_path != NULL) ?
1648 options.remote_forwards[i].listen_path :
1649 (options.remote_forwards[i].listen_host == NULL) ?
1650 "LOCALHOST" : options.remote_forwards[i].listen_host,
1651 options.remote_forwards[i].listen_port,
1652 (options.remote_forwards[i].connect_path != NULL) ?
1653 options.remote_forwards[i].connect_path :
1654 options.remote_forwards[i].connect_host,
1655 options.remote_forwards[i].connect_port);
1656 options.remote_forwards[i].handle =
1657 channel_request_remote_forwarding(
1658 &options.remote_forwards[i]);
1659 if (options.remote_forwards[i].handle < 0) {
1660 if (options.exit_on_forward_failure)
1661 fatal("Could not request remote forwarding.");
1662 else
1663 logit("Warning: Could not request remote "
1664 "forwarding.");
1665 } else {
1666 client_register_global_confirm(ssh_confirm_remote_forward,
1667 &options.remote_forwards[i]);
1668 }
1669 }
1670
1671 /* Initiate tunnel forwarding. */
1672 if (options.tun_open != SSH_TUNMODE_NO) {
1673 if (client_request_tun_fwd(options.tun_open,
1674 options.tun_local, options.tun_remote) == -1) {
1675 if (options.exit_on_forward_failure)
1676 fatal("Could not request tunnel forwarding.");
1677 else
1678 error("Could not request tunnel forwarding.");
1679 }
1680 }
1681 }
1682
1683 static void
check_agent_present(void)1684 check_agent_present(void)
1685 {
1686 int r;
1687
1688 if (options.forward_agent) {
1689 /* Clear agent forwarding if we don't have an agent. */
1690 if ((r = ssh_get_authentication_socket(NULL)) != 0) {
1691 options.forward_agent = 0;
1692 if (r != SSH_ERR_AGENT_NOT_PRESENT)
1693 debug("ssh_get_authentication_socket: %s",
1694 ssh_err(r));
1695 }
1696 }
1697 }
1698
1699 static int
ssh_session(void)1700 ssh_session(void)
1701 {
1702 int type;
1703 int interactive = 0;
1704 int have_tty = 0;
1705 struct winsize ws;
1706 char *cp;
1707 const char *display;
1708 char *proto = NULL, *data = NULL;
1709
1710 /* Enable compression if requested. */
1711 if (options.compression) {
1712 debug("Requesting compression at level %d.",
1713 options.compression_level);
1714
1715 if (options.compression_level < 1 ||
1716 options.compression_level > 9)
1717 fatal("Compression level must be from 1 (fast) to "
1718 "9 (slow, best).");
1719
1720 /* Send the request. */
1721 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
1722 packet_put_int(options.compression_level);
1723 packet_send();
1724 packet_write_wait();
1725 type = packet_read();
1726 if (type == SSH_SMSG_SUCCESS)
1727 packet_start_compression(options.compression_level);
1728 else if (type == SSH_SMSG_FAILURE)
1729 logit("Warning: Remote host refused compression.");
1730 else
1731 packet_disconnect("Protocol error waiting for "
1732 "compression response.");
1733 }
1734 /* Allocate a pseudo tty if appropriate. */
1735 if (tty_flag) {
1736 debug("Requesting pty.");
1737
1738 /* Start the packet. */
1739 packet_start(SSH_CMSG_REQUEST_PTY);
1740
1741 /* Store TERM in the packet. There is no limit on the
1742 length of the string. */
1743 cp = getenv("TERM");
1744 if (!cp)
1745 cp = "";
1746 packet_put_cstring(cp);
1747
1748 /* Store window size in the packet. */
1749 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
1750 memset(&ws, 0, sizeof(ws));
1751 packet_put_int((u_int)ws.ws_row);
1752 packet_put_int((u_int)ws.ws_col);
1753 packet_put_int((u_int)ws.ws_xpixel);
1754 packet_put_int((u_int)ws.ws_ypixel);
1755
1756 /* Store tty modes in the packet. */
1757 tty_make_modes(fileno(stdin), NULL);
1758
1759 /* Send the packet, and wait for it to leave. */
1760 packet_send();
1761 packet_write_wait();
1762
1763 /* Read response from the server. */
1764 type = packet_read();
1765 if (type == SSH_SMSG_SUCCESS) {
1766 interactive = 1;
1767 have_tty = 1;
1768 } else if (type == SSH_SMSG_FAILURE)
1769 logit("Warning: Remote host failed or refused to "
1770 "allocate a pseudo tty.");
1771 else
1772 packet_disconnect("Protocol error waiting for pty "
1773 "request response.");
1774 }
1775 /* Request X11 forwarding if enabled and DISPLAY is set. */
1776 display = getenv("DISPLAY");
1777 if (display == NULL && options.forward_x11)
1778 debug("X11 forwarding requested but DISPLAY not set");
1779 if (options.forward_x11 && client_x11_get_proto(display,
1780 options.xauth_location, options.forward_x11_trusted,
1781 options.forward_x11_timeout, &proto, &data) == 0) {
1782 /* Request forwarding with authentication spoofing. */
1783 debug("Requesting X11 forwarding with authentication "
1784 "spoofing.");
1785 x11_request_forwarding_with_spoofing(0, display, proto,
1786 data, 0);
1787 /* Read response from the server. */
1788 type = packet_read();
1789 if (type == SSH_SMSG_SUCCESS) {
1790 interactive = 1;
1791 } else if (type == SSH_SMSG_FAILURE) {
1792 logit("Warning: Remote host denied X11 forwarding.");
1793 } else {
1794 packet_disconnect("Protocol error waiting for X11 "
1795 "forwarding");
1796 }
1797 }
1798 /* Tell the packet module whether this is an interactive session. */
1799 packet_set_interactive(interactive,
1800 options.ip_qos_interactive, options.ip_qos_bulk);
1801
1802 /* Request authentication agent forwarding if appropriate. */
1803 check_agent_present();
1804
1805 if (options.forward_agent) {
1806 debug("Requesting authentication agent forwarding.");
1807 auth_request_forwarding();
1808
1809 /* Read response from the server. */
1810 type = packet_read();
1811 packet_check_eom();
1812 if (type != SSH_SMSG_SUCCESS)
1813 logit("Warning: Remote host denied authentication agent forwarding.");
1814 }
1815
1816 /* Initiate port forwardings. */
1817 ssh_init_stdio_forwarding();
1818 ssh_init_forwarding();
1819
1820 /* Execute a local command */
1821 if (options.local_command != NULL &&
1822 options.permit_local_command)
1823 ssh_local_cmd(options.local_command);
1824
1825 /*
1826 * If requested and we are not interested in replies to remote
1827 * forwarding requests, then let ssh continue in the background.
1828 */
1829 if (fork_after_authentication_flag) {
1830 if (options.exit_on_forward_failure &&
1831 options.num_remote_forwards > 0) {
1832 debug("deferring postauth fork until remote forward "
1833 "confirmation received");
1834 } else
1835 fork_postauth();
1836 }
1837
1838 /*
1839 * If a command was specified on the command line, execute the
1840 * command now. Otherwise request the server to start a shell.
1841 */
1842 if (buffer_len(&command) > 0) {
1843 int len = buffer_len(&command);
1844 if (len > 900)
1845 len = 900;
1846 debug("Sending command: %.*s", len,
1847 (u_char *)buffer_ptr(&command));
1848 packet_start(SSH_CMSG_EXEC_CMD);
1849 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1850 packet_send();
1851 packet_write_wait();
1852 } else {
1853 debug("Requesting shell.");
1854 packet_start(SSH_CMSG_EXEC_SHELL);
1855 packet_send();
1856 packet_write_wait();
1857 }
1858
1859 /* Enter the interactive session. */
1860 return client_loop(have_tty, tty_flag ?
1861 options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1862 }
1863
1864 /* request pty/x11/agent/tcpfwd/shell for channel */
1865 static void
ssh_session2_setup(int id,int success,void * arg)1866 ssh_session2_setup(int id, int success, void *arg)
1867 {
1868 extern char **environ;
1869 const char *display;
1870 int interactive = tty_flag;
1871 char *proto = NULL, *data = NULL;
1872
1873 if (!success)
1874 return; /* No need for error message, channels code sens one */
1875
1876 display = getenv("DISPLAY");
1877 if (display == NULL && options.forward_x11)
1878 debug("X11 forwarding requested but DISPLAY not set");
1879 if (options.forward_x11 && client_x11_get_proto(display,
1880 options.xauth_location, options.forward_x11_trusted,
1881 options.forward_x11_timeout, &proto, &data) == 0) {
1882 /* Request forwarding with authentication spoofing. */
1883 debug("Requesting X11 forwarding with authentication "
1884 "spoofing.");
1885 x11_request_forwarding_with_spoofing(id, display, proto,
1886 data, 1);
1887 client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
1888 /* XXX exit_on_forward_failure */
1889 interactive = 1;
1890 }
1891
1892 check_agent_present();
1893 if (options.forward_agent) {
1894 debug("Requesting authentication agent forwarding.");
1895 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1896 packet_send();
1897 }
1898
1899 /* Tell the packet module whether this is an interactive session. */
1900 packet_set_interactive(interactive,
1901 options.ip_qos_interactive, options.ip_qos_bulk);
1902
1903 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1904 NULL, fileno(stdin), &command, environ);
1905 }
1906
1907 /* open new channel for a session */
1908 static int
ssh_session2_open(void)1909 ssh_session2_open(void)
1910 {
1911 Channel *c;
1912 int window, packetmax, in, out, err;
1913
1914 if (stdin_null_flag) {
1915 in = open(_PATH_DEVNULL, O_RDONLY);
1916 } else {
1917 in = dup(STDIN_FILENO);
1918 }
1919 out = dup(STDOUT_FILENO);
1920 err = dup(STDERR_FILENO);
1921
1922 if (in < 0 || out < 0 || err < 0)
1923 fatal("dup() in/out/err failed");
1924
1925 /* enable nonblocking unless tty */
1926 if (!isatty(in))
1927 set_nonblock(in);
1928 if (!isatty(out))
1929 set_nonblock(out);
1930 if (!isatty(err))
1931 set_nonblock(err);
1932
1933 window = CHAN_SES_WINDOW_DEFAULT;
1934 packetmax = CHAN_SES_PACKET_DEFAULT;
1935 if (tty_flag) {
1936 window >>= 1;
1937 packetmax >>= 1;
1938 }
1939 c = channel_new(
1940 "session", SSH_CHANNEL_OPENING, in, out, err,
1941 window, packetmax, CHAN_EXTENDED_WRITE,
1942 "client-session", /*nonblock*/0);
1943
1944 debug3("ssh_session2_open: channel_new: %d", c->self);
1945
1946 channel_send_open(c->self);
1947 if (!no_shell_flag)
1948 channel_register_open_confirm(c->self,
1949 ssh_session2_setup, NULL);
1950
1951 return c->self;
1952 }
1953
1954 static int
ssh_session2(void)1955 ssh_session2(void)
1956 {
1957 int id = -1;
1958
1959 /* XXX should be pre-session */
1960 if (!options.control_persist)
1961 ssh_init_stdio_forwarding();
1962 ssh_init_forwarding();
1963
1964 /* Start listening for multiplex clients */
1965 if (!packet_get_mux())
1966 muxserver_listen();
1967
1968 /*
1969 * If we are in control persist mode and have a working mux listen
1970 * socket, then prepare to background ourselves and have a foreground
1971 * client attach as a control slave.
1972 * NB. we must save copies of the flags that we override for
1973 * the backgrounding, since we defer attachment of the slave until
1974 * after the connection is fully established (in particular,
1975 * async rfwd replies have been received for ExitOnForwardFailure).
1976 */
1977 if (options.control_persist && muxserver_sock != -1) {
1978 ostdin_null_flag = stdin_null_flag;
1979 ono_shell_flag = no_shell_flag;
1980 orequest_tty = options.request_tty;
1981 otty_flag = tty_flag;
1982 stdin_null_flag = 1;
1983 no_shell_flag = 1;
1984 tty_flag = 0;
1985 if (!fork_after_authentication_flag)
1986 need_controlpersist_detach = 1;
1987 fork_after_authentication_flag = 1;
1988 }
1989 /*
1990 * ControlPersist mux listen socket setup failed, attempt the
1991 * stdio forward setup that we skipped earlier.
1992 */
1993 if (options.control_persist && muxserver_sock == -1)
1994 ssh_init_stdio_forwarding();
1995
1996 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1997 id = ssh_session2_open();
1998 else {
1999 packet_set_interactive(
2000 options.control_master == SSHCTL_MASTER_NO,
2001 options.ip_qos_interactive, options.ip_qos_bulk);
2002 }
2003
2004 /* If we don't expect to open a new session, then disallow it */
2005 if (options.control_master == SSHCTL_MASTER_NO &&
2006 (datafellows & SSH_NEW_OPENSSH)) {
2007 debug("Requesting no-more-sessions@openssh.com");
2008 packet_start(SSH2_MSG_GLOBAL_REQUEST);
2009 packet_put_cstring("no-more-sessions@openssh.com");
2010 packet_put_char(0);
2011 packet_send();
2012 }
2013
2014 /* Execute a local command */
2015 if (options.local_command != NULL &&
2016 options.permit_local_command)
2017 ssh_local_cmd(options.local_command);
2018
2019 /*
2020 * If requested and we are not interested in replies to remote
2021 * forwarding requests, then let ssh continue in the background.
2022 */
2023 if (fork_after_authentication_flag) {
2024 if (options.exit_on_forward_failure &&
2025 options.num_remote_forwards > 0) {
2026 debug("deferring postauth fork until remote forward "
2027 "confirmation received");
2028 } else
2029 fork_postauth();
2030 }
2031
2032 return client_loop(tty_flag, tty_flag ?
2033 options.escape_char : SSH_ESCAPECHAR_NONE, id);
2034 }
2035
2036 /* Loads all IdentityFile and CertificateFile keys */
2037 static void
load_public_identity_files(void)2038 load_public_identity_files(void)
2039 {
2040 char *filename, *cp, thishost[NI_MAXHOST];
2041 char *pwdir = NULL, *pwname = NULL;
2042 Key *public;
2043 struct passwd *pw;
2044 int i;
2045 u_int n_ids, n_certs;
2046 char *identity_files[SSH_MAX_IDENTITY_FILES];
2047 Key *identity_keys[SSH_MAX_IDENTITY_FILES];
2048 char *certificate_files[SSH_MAX_CERTIFICATE_FILES];
2049 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES];
2050 #ifdef ENABLE_PKCS11
2051 Key **keys;
2052 int nkeys;
2053 #endif /* PKCS11 */
2054
2055 n_ids = n_certs = 0;
2056 memset(identity_files, 0, sizeof(identity_files));
2057 memset(identity_keys, 0, sizeof(identity_keys));
2058 memset(certificate_files, 0, sizeof(certificate_files));
2059 memset(certificates, 0, sizeof(certificates));
2060
2061 #ifdef ENABLE_PKCS11
2062 if (options.pkcs11_provider != NULL &&
2063 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
2064 (pkcs11_init(!options.batch_mode) == 0) &&
2065 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL,
2066 &keys)) > 0) {
2067 for (i = 0; i < nkeys; i++) {
2068 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
2069 key_free(keys[i]);
2070 continue;
2071 }
2072 identity_keys[n_ids] = keys[i];
2073 identity_files[n_ids] =
2074 xstrdup(options.pkcs11_provider); /* XXX */
2075 n_ids++;
2076 }
2077 free(keys);
2078 }
2079 #endif /* ENABLE_PKCS11 */
2080 if ((pw = getpwuid(original_real_uid)) == NULL)
2081 fatal("load_public_identity_files: getpwuid failed");
2082 pwname = xstrdup(pw->pw_name);
2083 pwdir = xstrdup(pw->pw_dir);
2084 if (gethostname(thishost, sizeof(thishost)) == -1)
2085 fatal("load_public_identity_files: gethostname: %s",
2086 strerror(errno));
2087 for (i = 0; i < options.num_identity_files; i++) {
2088 if (n_ids >= SSH_MAX_IDENTITY_FILES ||
2089 strcasecmp(options.identity_files[i], "none") == 0) {
2090 free(options.identity_files[i]);
2091 options.identity_files[i] = NULL;
2092 continue;
2093 }
2094 cp = tilde_expand_filename(options.identity_files[i],
2095 original_real_uid);
2096 filename = percent_expand(cp, "d", pwdir,
2097 "u", pwname, "l", thishost, "h", host,
2098 "r", options.user, (char *)NULL);
2099 free(cp);
2100 public = key_load_public(filename, NULL);
2101 debug("identity file %s type %d", filename,
2102 public ? public->type : -1);
2103 free(options.identity_files[i]);
2104 identity_files[n_ids] = filename;
2105 identity_keys[n_ids] = public;
2106
2107 if (++n_ids >= SSH_MAX_IDENTITY_FILES)
2108 continue;
2109
2110 /*
2111 * If no certificates have been explicitly listed then try
2112 * to add the default certificate variant too.
2113 */
2114 if (options.num_certificate_files != 0)
2115 continue;
2116 xasprintf(&cp, "%s-cert", filename);
2117 public = key_load_public(cp, NULL);
2118 debug("identity file %s type %d", cp,
2119 public ? public->type : -1);
2120 if (public == NULL) {
2121 free(cp);
2122 continue;
2123 }
2124 if (!key_is_cert(public)) {
2125 debug("%s: key %s type %s is not a certificate",
2126 __func__, cp, key_type(public));
2127 key_free(public);
2128 free(cp);
2129 continue;
2130 }
2131 /* NB. leave filename pointing to private key */
2132 identity_files[n_ids] = xstrdup(filename);
2133 identity_keys[n_ids] = public;
2134 n_ids++;
2135 }
2136
2137 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES)
2138 fatal("%s: too many certificates", __func__);
2139 for (i = 0; i < options.num_certificate_files; i++) {
2140 cp = tilde_expand_filename(options.certificate_files[i],
2141 original_real_uid);
2142 filename = percent_expand(cp, "d", pwdir,
2143 "u", pwname, "l", thishost, "h", host,
2144 "r", options.user, (char *)NULL);
2145 free(cp);
2146
2147 public = key_load_public(filename, NULL);
2148 debug("certificate file %s type %d", filename,
2149 public ? public->type : -1);
2150 free(options.certificate_files[i]);
2151 options.certificate_files[i] = NULL;
2152 if (public == NULL) {
2153 free(filename);
2154 continue;
2155 }
2156 if (!key_is_cert(public)) {
2157 debug("%s: key %s type %s is not a certificate",
2158 __func__, filename, key_type(public));
2159 key_free(public);
2160 free(filename);
2161 continue;
2162 }
2163 certificate_files[n_certs] = filename;
2164 certificates[n_certs] = public;
2165 ++n_certs;
2166 }
2167
2168 options.num_identity_files = n_ids;
2169 memcpy(options.identity_files, identity_files, sizeof(identity_files));
2170 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys));
2171
2172 options.num_certificate_files = n_certs;
2173 memcpy(options.certificate_files,
2174 certificate_files, sizeof(certificate_files));
2175 memcpy(options.certificates, certificates, sizeof(certificates));
2176
2177 explicit_bzero(pwname, strlen(pwname));
2178 free(pwname);
2179 explicit_bzero(pwdir, strlen(pwdir));
2180 free(pwdir);
2181 }
2182
2183 static void
main_sigchld_handler(int sig)2184 main_sigchld_handler(int sig)
2185 {
2186 int save_errno = errno;
2187 pid_t pid;
2188 int status;
2189
2190 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
2191 (pid < 0 && errno == EINTR))
2192 ;
2193
2194 signal(sig, main_sigchld_handler);
2195 errno = save_errno;
2196 }
2197