1 /* $OpenBSD: ssh.c,v 1.416 2015/03/03 06:48:58 djm Exp $ */
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
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.
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".
16 * Copyright (c) 1999 Niels Provos. All rights reserved.
17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved.
19 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
20 * in Canada (German citizen).
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
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.
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.
45 #include <sys/types.h>
46 #ifdef HAVE_SYS_STAT_H
47 # include <sys/stat.h>
49 #include <sys/resource.h>
50 #include <sys/ioctl.h>
51 #include <sys/socket.h>
71 #include <netinet/in.h>
72 #include <arpa/inet.h>
75 #include <openssl/evp.h>
76 #include <openssl/err.h>
78 #include "openbsd-compat/openssl-compat.h"
79 #include "openbsd-compat/sys-queue.h"
95 #include "pathnames.h"
97 #include "clientloop.h"
100 #include "readconf.h"
101 #include "sshconnect.h"
113 #include "ssh-pkcs11.h"
116 extern char *__progname;
118 /* Saves a copy of argv for setproctitle emulation */
119 #ifndef HAVE_SETPROCTITLE
120 static char **saved_av;
123 /* Flag indicating whether debug mode is on. May be set on the command line. */
126 /* Flag indicating whether a tty should be requested */
129 /* don't exec a shell */
130 int no_shell_flag = 0;
133 * Flag indicating that nothing should be read from stdin. This can be set
134 * on the command line.
136 int stdin_null_flag = 0;
139 * Flag indicating that the current process should be backgrounded and
140 * a new slave launched in the foreground for ControlPersist.
142 int need_controlpersist_detach = 0;
144 /* Copies of flags for ControlPersist foreground slave */
145 int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty;
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
152 int fork_after_authentication_flag = 0;
154 /* forward stdio to remote host and port */
155 char *stdio_forward_host = NULL;
156 int stdio_forward_port = 0;
159 * General data structure for command line options and options configurable
160 * in configuration files. See readconf.h.
164 /* optional user configfile */
168 * Name of the host we are connecting to. This is the name given on the
169 * command line, or the HostName specified for the user-supplied name in a
170 * configuration file.
174 /* socket address the host resolves to */
175 struct sockaddr_storage hostaddr;
177 /* Private host keys. */
178 Sensitive sensitive_data;
180 /* Original real UID. */
181 uid_t original_real_uid;
182 uid_t original_effective_uid;
184 /* command to be executed */
187 /* Should we execute a command or invoke a subsystem? */
188 int subsystem_flag = 0;
190 /* # of replies received for global requests */
191 static int remote_forward_confirms_received = 0;
194 extern int muxserver_sock;
195 extern u_int muxclient_command;
197 /* Prints a help message to the user. This function never returns. */
203 "usage: ssh [-1246AaCfGgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n"
204 " [-D [bind_address:]port] [-E log_file] [-e escape_char]\n"
205 " [-F configfile] [-I pkcs11] [-i identity_file]\n"
206 " [-L [bind_address:]port:host:hostport] [-l login_name] [-m mac_spec]\n"
207 " [-O ctl_cmd] [-o option] [-p port]\n"
208 " [-Q cipher | cipher-auth | mac | kex | key]\n"
209 " [-R [bind_address:]port:host:hostport] [-S ctl_path] [-W host:port]\n"
210 " [-w local_tun[:remote_tun]] [user@]hostname [command]\n"
215 static int ssh_session(void);
216 static int ssh_session2(void);
217 static void load_public_identity_files(void);
218 static void main_sigchld_handler(int);
220 /* from muxclient.c */
221 void muxclient(const char *);
222 void muxserver_listen(void);
224 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */
226 tilde_expand_paths(char **paths, u_int num_paths)
231 for (i = 0; i < num_paths; i++) {
232 cp = tilde_expand_filename(paths[i], original_real_uid);
239 * Attempt to resolve a host name / port to a set of addresses and
240 * optionally return any CNAMEs encountered along the way.
241 * Returns NULL on failure.
242 * NB. this function must operate with a options having undefined members.
244 static struct addrinfo *
245 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen)
247 char strport[NI_MAXSERV];
248 struct addrinfo hints, *res;
249 int gaierr, loglevel = SYSLOG_LEVEL_DEBUG1;
252 port = default_ssh_port();
254 snprintf(strport, sizeof strport, "%u", port);
255 memset(&hints, 0, sizeof(hints));
256 hints.ai_family = options.address_family == -1 ?
257 AF_UNSPEC : options.address_family;
258 hints.ai_socktype = SOCK_STREAM;
260 hints.ai_flags = AI_CANONNAME;
261 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
262 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA))
263 loglevel = SYSLOG_LEVEL_ERROR;
264 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s",
265 __progname, name, ssh_gai_strerror(gaierr));
268 if (cname != NULL && res->ai_canonname != NULL) {
269 if (strlcpy(cname, res->ai_canonname, clen) >= clen) {
270 error("%s: host \"%s\" cname \"%s\" too long (max %lu)",
271 __func__, name, res->ai_canonname, (u_long)clen);
280 * Attempt to resolve a numeric host address / port to a single address.
281 * Returns a canonical address string.
282 * Returns NULL on failure.
283 * NB. this function must operate with a options having undefined members.
285 static struct addrinfo *
286 resolve_addr(const char *name, int port, char *caddr, size_t clen)
288 char addr[NI_MAXHOST], strport[NI_MAXSERV];
289 struct addrinfo hints, *res;
293 port = default_ssh_port();
294 snprintf(strport, sizeof strport, "%u", port);
295 memset(&hints, 0, sizeof(hints));
296 hints.ai_family = options.address_family == -1 ?
297 AF_UNSPEC : options.address_family;
298 hints.ai_socktype = SOCK_STREAM;
299 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV;
300 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) {
301 debug2("%s: could not resolve name %.100s as address: %s",
302 __func__, name, ssh_gai_strerror(gaierr));
306 debug("%s: getaddrinfo %.100s returned no addresses",
310 if (res->ai_next != NULL) {
311 debug("%s: getaddrinfo %.100s returned multiple addresses",
315 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen,
316 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) {
317 debug("%s: Could not format address for name %.100s: %s",
318 __func__, name, ssh_gai_strerror(gaierr));
321 if (strlcpy(caddr, addr, clen) >= clen) {
322 error("%s: host \"%s\" addr \"%s\" too long (max %lu)",
323 __func__, name, addr, (u_long)clen);
334 * Check whether the cname is a permitted replacement for the hostname
335 * and perform the replacement if it is.
336 * NB. this function must operate with a options having undefined members.
339 check_follow_cname(char **namep, const char *cname)
342 struct allowed_cname *rule;
344 if (*cname == '\0' || options.num_permitted_cnames == 0 ||
345 strcmp(*namep, cname) == 0)
347 if (options.canonicalize_hostname == SSH_CANONICALISE_NO)
350 * Don't attempt to canonicalize names that will be interpreted by
351 * a proxy unless the user specifically requests so.
353 if (!option_clear_or_none(options.proxy_command) &&
354 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
356 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname);
357 for (i = 0; i < options.num_permitted_cnames; i++) {
358 rule = options.permitted_cnames + i;
359 if (match_pattern_list(*namep, rule->source_list,
360 strlen(rule->source_list), 1) != 1 ||
361 match_pattern_list(cname, rule->target_list,
362 strlen(rule->target_list), 1) != 1)
364 verbose("Canonicalized DNS aliased hostname "
365 "\"%s\" => \"%s\"", *namep, cname);
367 *namep = xstrdup(cname);
374 * Attempt to resolve the supplied hostname after applying the user's
375 * canonicalization rules. Returns the address list for the host or NULL
376 * if no name was found after canonicalization.
377 * NB. this function must operate with a options having undefined members.
379 static struct addrinfo *
380 resolve_canonicalize(char **hostp, int port)
383 char *cp, *fullhost, newname[NI_MAXHOST];
384 struct addrinfo *addrs;
386 if (options.canonicalize_hostname == SSH_CANONICALISE_NO)
390 * Don't attempt to canonicalize names that will be interpreted by
391 * a proxy unless the user specifically requests so.
393 if (!option_clear_or_none(options.proxy_command) &&
394 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS)
397 /* Try numeric hostnames first */
398 if ((addrs = resolve_addr(*hostp, port,
399 newname, sizeof(newname))) != NULL) {
400 debug2("%s: hostname %.100s is address", __func__, *hostp);
401 if (strcasecmp(*hostp, newname) != 0) {
402 debug2("%s: canonicalised address \"%s\" => \"%s\"",
403 __func__, *hostp, newname);
405 *hostp = xstrdup(newname);
410 /* Don't apply canonicalization to sufficiently-qualified hostnames */
412 for (cp = *hostp; *cp != '\0'; cp++) {
416 if (ndots > options.canonicalize_max_dots) {
417 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)",
418 __func__, *hostp, options.canonicalize_max_dots);
421 /* Attempt each supplied suffix */
422 for (i = 0; i < options.num_canonical_domains; i++) {
424 xasprintf(&fullhost, "%s.%s.", *hostp,
425 options.canonical_domains[i]);
426 debug3("%s: attempting \"%s\" => \"%s\"", __func__,
428 if ((addrs = resolve_host(fullhost, port, 0,
429 newname, sizeof(newname))) == NULL) {
433 /* Remove trailing '.' */
434 fullhost[strlen(fullhost) - 1] = '\0';
435 /* Follow CNAME if requested */
436 if (!check_follow_cname(&fullhost, newname)) {
437 debug("Canonicalized hostname \"%s\" => \"%s\"",
444 if (!options.canonicalize_fallback_local)
445 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp);
446 debug2("%s: host %s not found in any suffix", __func__, *hostp);
451 * Read per-user configuration file. Ignore the system wide config
452 * file if the user specifies a config file on the command line.
455 process_config_files(const char *host_arg, struct passwd *pw, int post_canon)
460 if (config != NULL) {
461 if (strcasecmp(config, "none") != 0 &&
462 !read_config_file(config, pw, host, host_arg, &options,
463 SSHCONF_USERCONF | (post_canon ? SSHCONF_POSTCANON : 0)))
464 fatal("Can't open user config file %.100s: "
465 "%.100s", config, strerror(errno));
467 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
468 _PATH_SSH_USER_CONFFILE);
469 if (r > 0 && (size_t)r < sizeof(buf))
470 (void)read_config_file(buf, pw, host, host_arg,
471 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF |
472 (post_canon ? SSHCONF_POSTCANON : 0));
474 /* Read systemwide configuration file after user config. */
475 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw,
476 host, host_arg, &options,
477 post_canon ? SSHCONF_POSTCANON : 0);
481 /* Rewrite the port number in an addrinfo list of addresses */
483 set_addrinfo_port(struct addrinfo *addrs, int port)
485 struct addrinfo *addr;
487 for (addr = addrs; addr != NULL; addr = addr->ai_next) {
488 switch (addr->ai_family) {
490 ((struct sockaddr_in *)addr->ai_addr)->
491 sin_port = htons(port);
494 ((struct sockaddr_in6 *)addr->ai_addr)->
495 sin6_port = htons(port);
502 * Main program for the ssh client.
505 main(int ac, char **av)
507 int i, r, opt, exit_status, use_syslog, config_test = 0;
508 char *p, *cp, *line, *argv0, buf[PATH_MAX], *host_arg, *logfile;
509 char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
510 char cname[NI_MAXHOST];
514 extern int optind, optreset;
517 struct addrinfo *addrs = NULL;
518 struct ssh_digest_ctx *md;
519 u_char conn_hash[SSH_DIGEST_MAX_LENGTH];
522 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
525 __progname = ssh_get_progname(av[0]);
527 #ifndef HAVE_SETPROCTITLE
528 /* Prepare for later setproctitle emulation */
529 /* Save argv so it isn't clobbered by setproctitle() emulation */
530 saved_av = xcalloc(ac + 1, sizeof(*saved_av));
531 for (i = 0; i < ac; i++)
532 saved_av[i] = xstrdup(av[i]);
534 compat_init_setproctitle(ac, av);
539 * Discard other fds that are hanging around. These can cause problem
540 * with backgrounded ssh processes started by ControlPersist.
542 closefrom(STDERR_FILENO + 1);
545 * Save the original real uid. It will be needed later (uid-swapping
546 * may clobber the real uid).
548 original_real_uid = getuid();
549 original_effective_uid = geteuid();
552 * Use uid-swapping to give up root privileges for the duration of
553 * option processing. We will re-instantiate the rights when we are
554 * ready to create the privileged port, and will permanently drop
555 * them when the port has been created (actually, when the connection
556 * has been made, as we may need to create the port several times).
560 #ifdef HAVE_SETRLIMIT
561 /* If we are installed setuid root be careful to not drop core. */
562 if (original_real_uid != original_effective_uid) {
564 rlim.rlim_cur = rlim.rlim_max = 0;
565 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
566 fatal("setrlimit failed: %.100s", strerror(errno));
570 pw = getpwuid(original_real_uid);
572 logit("No user exists for uid %lu", (u_long)original_real_uid);
575 /* Take a copy of the returned structure. */
579 * Set our umask to something reasonable, as some files are created
580 * with the default umask. This will make them world-readable but
581 * writable only by the owner, which is ok for all files for which we
582 * don't set the modes explicitly.
587 * Initialize option structure to indicate that no values have been
590 initialize_options(&options);
592 /* Parse command-line arguments. */
599 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
600 "ACD:E:F:GI:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) {
603 options.protocol = SSH_PROTO_1;
606 options.protocol = SSH_PROTO_2;
609 options.address_family = AF_INET;
612 options.address_family = AF_INET6;
618 fork_after_authentication_flag = 1;
622 options.forward_x11 = 0;
625 options.forward_x11 = 1;
631 logfile = xstrdup(optarg);
637 options.forward_x11 = 1;
638 options.forward_x11_trusted = 1;
641 options.fwd_opts.gateway_ports = 1;
644 if (stdio_forward_host != NULL)
645 fatal("Cannot specify multiplexing "
647 else if (muxclient_command != 0)
648 fatal("Multiplexing command already specified");
649 if (strcmp(optarg, "check") == 0)
650 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
651 else if (strcmp(optarg, "forward") == 0)
652 muxclient_command = SSHMUX_COMMAND_FORWARD;
653 else if (strcmp(optarg, "exit") == 0)
654 muxclient_command = SSHMUX_COMMAND_TERMINATE;
655 else if (strcmp(optarg, "stop") == 0)
656 muxclient_command = SSHMUX_COMMAND_STOP;
657 else if (strcmp(optarg, "cancel") == 0)
658 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD;
660 fatal("Invalid multiplex command.");
662 case 'P': /* deprecated */
663 options.use_privileged_port = 0;
667 if (strcmp(optarg, "cipher") == 0)
668 cp = cipher_alg_list('\n', 0);
669 else if (strcmp(optarg, "cipher-auth") == 0)
670 cp = cipher_alg_list('\n', 1);
671 else if (strcmp(optarg, "mac") == 0)
672 cp = mac_alg_list('\n');
673 else if (strcmp(optarg, "kex") == 0)
674 cp = kex_alg_list('\n');
675 else if (strcmp(optarg, "key") == 0)
676 cp = key_alg_list(0, 0);
677 else if (strcmp(optarg, "key-cert") == 0)
678 cp = key_alg_list(1, 0);
679 else if (strcmp(optarg, "key-plain") == 0)
680 cp = key_alg_list(0, 1);
681 else if (strcmp(optarg, "protocol-version") == 0) {
683 cp = xstrdup("1\n2");
689 fatal("Unsupported query \"%s\"", optarg);
695 options.forward_agent = 0;
698 options.forward_agent = 1;
701 options.gss_deleg_creds = 0;
704 options.gss_authentication = 1;
705 options.gss_deleg_creds = 1;
708 if (stat(optarg, &st) < 0) {
709 fprintf(stderr, "Warning: Identity file %s "
710 "not accessible: %s.\n", optarg,
714 add_identity_file(&options, NULL, optarg, 1);
718 options.pkcs11_provider = xstrdup(optarg);
720 fprintf(stderr, "no support for PKCS#11.\n");
724 if (options.request_tty == REQUEST_TTY_YES)
725 options.request_tty = REQUEST_TTY_FORCE;
727 options.request_tty = REQUEST_TTY_YES;
730 if (debug_flag == 0) {
732 options.log_level = SYSLOG_LEVEL_DEBUG1;
734 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
739 fprintf(stderr, "%s, %s\n",
742 SSLeay_version(SSLEAY_VERSION)
751 if (options.tun_open == -1)
752 options.tun_open = SSH_TUNMODE_DEFAULT;
753 options.tun_local = a2tun(optarg, &options.tun_remote);
754 if (options.tun_local == SSH_TUNID_ERR) {
756 "Bad tun device '%s'\n", optarg);
761 if (stdio_forward_host != NULL)
762 fatal("stdio forward already specified");
763 if (muxclient_command != 0)
764 fatal("Cannot specify stdio forward with -O");
765 if (parse_forward(&fwd, optarg, 1, 0)) {
766 stdio_forward_host = fwd.listen_host;
767 stdio_forward_port = fwd.listen_port;
768 free(fwd.connect_host);
771 "Bad stdio forwarding specification '%s'\n",
775 options.request_tty = REQUEST_TTY_NO;
777 options.clear_forwardings = 1;
778 options.exit_on_forward_failure = 1;
781 options.log_level = SYSLOG_LEVEL_QUIET;
784 if (optarg[0] == '^' && optarg[2] == 0 &&
785 (u_char) optarg[1] >= 64 &&
786 (u_char) optarg[1] < 128)
787 options.escape_char = (u_char) optarg[1] & 31;
788 else if (strlen(optarg) == 1)
789 options.escape_char = (u_char) optarg[0];
790 else if (strcmp(optarg, "none") == 0)
791 options.escape_char = SSH_ESCAPECHAR_NONE;
793 fprintf(stderr, "Bad escape character '%s'.\n",
799 if (ciphers_valid(optarg)) {
801 options.ciphers = xstrdup(optarg);
802 options.cipher = SSH_CIPHER_INVALID;
805 options.cipher = cipher_number(optarg);
806 if (options.cipher == -1) {
808 "Unknown cipher type '%s'\n",
812 if (options.cipher == SSH_CIPHER_3DES)
813 options.ciphers = "3des-cbc";
814 else if (options.cipher == SSH_CIPHER_BLOWFISH)
815 options.ciphers = "blowfish-cbc";
817 options.ciphers = (char *)-1;
821 if (mac_valid(optarg))
822 options.macs = xstrdup(optarg);
824 fprintf(stderr, "Unknown mac type '%s'\n",
830 if (options.control_master == SSHCTL_MASTER_YES)
831 options.control_master = SSHCTL_MASTER_ASK;
833 options.control_master = SSHCTL_MASTER_YES;
836 options.port = a2port(optarg);
837 if (options.port <= 0) {
838 fprintf(stderr, "Bad port '%s'\n", optarg);
843 options.user = optarg;
847 if (parse_forward(&fwd, optarg, 0, 0))
848 add_local_forward(&options, &fwd);
851 "Bad local forwarding specification '%s'\n",
858 if (parse_forward(&fwd, optarg, 0, 1)) {
859 add_remote_forward(&options, &fwd);
862 "Bad remote forwarding specification "
869 if (parse_forward(&fwd, optarg, 1, 0)) {
870 add_local_forward(&options, &fwd);
873 "Bad dynamic forwarding specification "
880 options.compression = 1;
884 options.request_tty = REQUEST_TTY_NO;
887 options.request_tty = REQUEST_TTY_NO;
890 line = xstrdup(optarg);
891 if (process_config_line(&options, pw,
892 host ? host : "", host ? host : "", line,
893 "command-line", 0, NULL, SSHCONF_USERCONF) != 0)
901 if (options.control_path != NULL)
902 free(options.control_path);
903 options.control_path = xstrdup(optarg);
906 options.bind_address = optarg;
919 if (ac > 0 && !host) {
920 if (strrchr(*av, '@')) {
922 cp = strrchr(p, '@');
923 if (cp == NULL || cp == p)
927 host = xstrdup(++cp);
931 optind = optreset = 1;
937 /* Check that we got a host name. */
941 host_arg = xstrdup(host);
944 OpenSSL_add_all_algorithms();
945 ERR_load_crypto_strings();
948 /* Initialize the command to execute on remote host. */
949 buffer_init(&command);
952 * Save the command to execute on the remote host in a buffer. There
953 * is no limit on the length of the command, except by the maximum
954 * packet size. Also sets the tty flag if there is no command.
957 /* No command specified - execute shell on a tty. */
958 if (subsystem_flag) {
960 "You must specify a subsystem to invoke.\n");
964 /* A command has been specified. Store it into the buffer. */
965 for (i = 0; i < ac; i++) {
967 buffer_append(&command, " ", 1);
968 buffer_append(&command, av[i], strlen(av[i]));
972 /* Cannot fork to background if no command. */
973 if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
975 fatal("Cannot fork into background without a command "
979 * Initialize "log" output. Since we are the client all output
980 * goes to stderr unless otherwise specified by -y or -E.
982 if (use_syslog && logfile != NULL)
983 fatal("Can't specify both -y and -E");
984 if (logfile != NULL) {
985 log_redirect_stderr_to(logfile);
989 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
990 SYSLOG_FACILITY_USER, !use_syslog);
993 logit("%s, %s", SSH_RELEASE,
995 SSLeay_version(SSLEAY_VERSION)
1001 /* Parse the configuration files */
1002 process_config_files(host_arg, pw, 0);
1004 /* Hostname canonicalisation needs a few options filled. */
1005 fill_default_options_for_canonicalization(&options);
1007 /* If the user has replaced the hostname then take it into use now */
1008 if (options.hostname != NULL) {
1009 /* NB. Please keep in sync with readconf.c:match_cfg_line() */
1010 cp = percent_expand(options.hostname,
1011 "h", host, (char *)NULL);
1014 free(options.hostname);
1015 options.hostname = xstrdup(host);
1018 /* If canonicalization requested then try to apply it */
1020 if (options.canonicalize_hostname != SSH_CANONICALISE_NO)
1021 addrs = resolve_canonicalize(&host, options.port);
1024 * If CanonicalizePermittedCNAMEs have been specified but
1025 * other canonicalization did not happen (by not being requested
1026 * or by failing with fallback) then the hostname may still be changed
1027 * as a result of CNAME following.
1029 * Try to resolve the bare hostname name using the system resolver's
1030 * usual search rules and then apply the CNAME follow rules.
1032 * Skip the lookup if a ProxyCommand is being used unless the user
1033 * has specifically requested canonicalisation for this case via
1034 * CanonicalizeHostname=always
1036 if (addrs == NULL && options.num_permitted_cnames != 0 &&
1037 (option_clear_or_none(options.proxy_command) ||
1038 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) {
1039 if ((addrs = resolve_host(host, options.port,
1040 option_clear_or_none(options.proxy_command),
1041 cname, sizeof(cname))) == NULL) {
1042 /* Don't fatal proxied host names not in the DNS */
1043 if (option_clear_or_none(options.proxy_command))
1044 cleanup_exit(255); /* logged in resolve_host */
1046 check_follow_cname(&host, cname);
1050 * If canonicalisation is enabled then re-parse the configuration
1051 * files as new stanzas may match.
1053 if (options.canonicalize_hostname != 0) {
1054 debug("Re-reading configuration after hostname "
1055 "canonicalisation");
1056 free(options.hostname);
1057 options.hostname = xstrdup(host);
1058 process_config_files(host_arg, pw, 1);
1060 * Address resolution happens early with canonicalisation
1061 * enabled and the port number may have changed since, so
1062 * reset it in address list
1064 if (addrs != NULL && options.port > 0)
1065 set_addrinfo_port(addrs, options.port);
1068 /* Fill configuration defaults. */
1069 fill_default_options(&options);
1071 if (options.port == 0)
1072 options.port = default_ssh_port();
1073 channel_set_af(options.address_family);
1075 /* Tidy and check options */
1076 if (options.host_key_alias != NULL)
1077 lowercase(options.host_key_alias);
1078 if (options.proxy_command != NULL &&
1079 strcmp(options.proxy_command, "-") == 0 &&
1080 options.proxy_use_fdpass)
1081 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible");
1082 if (options.control_persist &&
1083 options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) {
1084 debug("UpdateHostKeys=ask is incompatible with ControlPersist; "
1086 options.update_hostkeys = 0;
1089 if (original_effective_uid != 0)
1090 options.use_privileged_port = 0;
1094 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
1096 if (options.request_tty == REQUEST_TTY_YES ||
1097 options.request_tty == REQUEST_TTY_FORCE)
1100 /* Allocate a tty by default if no command specified. */
1101 if (buffer_len(&command) == 0)
1102 tty_flag = options.request_tty != REQUEST_TTY_NO;
1105 if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0)
1107 /* Do not allocate a tty if stdin is not a tty. */
1108 if ((!isatty(fileno(stdin)) || stdin_null_flag) &&
1109 options.request_tty != REQUEST_TTY_FORCE) {
1111 logit("Pseudo-terminal will not be allocated because "
1112 "stdin is not a terminal.");
1118 if (options.user == NULL)
1119 options.user = xstrdup(pw->pw_name);
1121 if (gethostname(thishost, sizeof(thishost)) == -1)
1122 fatal("gethostname: %s", strerror(errno));
1123 strlcpy(shorthost, thishost, sizeof(shorthost));
1124 shorthost[strcspn(thishost, ".")] = '\0';
1125 snprintf(portstr, sizeof(portstr), "%d", options.port);
1127 if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL ||
1128 ssh_digest_update(md, thishost, strlen(thishost)) < 0 ||
1129 ssh_digest_update(md, host, strlen(host)) < 0 ||
1130 ssh_digest_update(md, portstr, strlen(portstr)) < 0 ||
1131 ssh_digest_update(md, options.user, strlen(options.user)) < 0 ||
1132 ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0)
1133 fatal("%s: mux digest failed", __func__);
1134 ssh_digest_free(md);
1135 conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1));
1137 if (options.local_command != NULL) {
1138 debug3("expanding LocalCommand: %s", options.local_command);
1139 cp = options.local_command;
1140 options.local_command = percent_expand(cp,
1151 debug3("expanded LocalCommand: %s", options.local_command);
1155 if (options.control_path != NULL) {
1156 cp = tilde_expand_filename(options.control_path,
1158 free(options.control_path);
1159 options.control_path = percent_expand(cp,
1171 free(conn_hash_hex);
1174 dump_client_config(&options, host);
1178 if (muxclient_command != 0 && options.control_path == NULL)
1179 fatal("No ControlPath specified for \"-O\" command");
1180 if (options.control_path != NULL)
1181 muxclient(options.control_path);
1184 * If hostname canonicalisation was not enabled, then we may not
1185 * have yet resolved the hostname. Do so now.
1187 if (addrs == NULL && options.proxy_command == NULL) {
1188 if ((addrs = resolve_host(host, options.port, 1,
1189 cname, sizeof(cname))) == NULL)
1190 cleanup_exit(255); /* resolve_host logs the error */
1193 timeout_ms = options.connection_timeout * 1000;
1195 /* Open a connection to the remote host. */
1196 if (ssh_connect(host, addrs, &hostaddr, options.port,
1197 options.address_family, options.connection_attempts,
1198 &timeout_ms, options.tcp_keep_alive,
1199 options.use_privileged_port) != 0)
1203 freeaddrinfo(addrs);
1205 packet_set_timeout(options.server_alive_interval,
1206 options.server_alive_count_max);
1209 debug3("timeout: %d ms remain after connect", timeout_ms);
1212 * If we successfully made the connection, load the host private key
1213 * in case we will need it later for combined rsa-rhosts
1214 * authentication. This must be done before releasing extra
1215 * privileges, because the file is only readable by root.
1216 * If we cannot access the private keys, load the public keys
1217 * instead and try to execute the ssh-keysign helper instead.
1219 sensitive_data.nkeys = 0;
1220 sensitive_data.keys = NULL;
1221 sensitive_data.external_keysign = 0;
1222 if (options.rhosts_rsa_authentication ||
1223 options.hostbased_authentication) {
1224 sensitive_data.nkeys = 9;
1225 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
1227 for (i = 0; i < sensitive_data.nkeys; i++)
1228 sensitive_data.keys[i] = NULL;
1231 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
1232 _PATH_HOST_KEY_FILE, "", NULL, NULL);
1233 #ifdef OPENSSL_HAS_ECC
1234 sensitive_data.keys[1] = key_load_private_cert(KEY_ECDSA,
1235 _PATH_HOST_ECDSA_KEY_FILE, "", NULL);
1237 sensitive_data.keys[2] = key_load_private_cert(KEY_ED25519,
1238 _PATH_HOST_ED25519_KEY_FILE, "", NULL);
1239 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA,
1240 _PATH_HOST_RSA_KEY_FILE, "", NULL);
1241 sensitive_data.keys[4] = key_load_private_cert(KEY_DSA,
1242 _PATH_HOST_DSA_KEY_FILE, "", NULL);
1243 #ifdef OPENSSL_HAS_ECC
1244 sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA,
1245 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL);
1247 sensitive_data.keys[6] = key_load_private_type(KEY_ED25519,
1248 _PATH_HOST_ED25519_KEY_FILE, "", NULL, NULL);
1249 sensitive_data.keys[7] = key_load_private_type(KEY_RSA,
1250 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
1251 sensitive_data.keys[8] = key_load_private_type(KEY_DSA,
1252 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
1255 if (options.hostbased_authentication == 1 &&
1256 sensitive_data.keys[0] == NULL &&
1257 sensitive_data.keys[5] == NULL &&
1258 sensitive_data.keys[6] == NULL &&
1259 sensitive_data.keys[7] == NULL &&
1260 sensitive_data.keys[8] == NULL) {
1261 #ifdef OPENSSL_HAS_ECC
1262 sensitive_data.keys[1] = key_load_cert(
1263 _PATH_HOST_ECDSA_KEY_FILE);
1265 sensitive_data.keys[2] = key_load_cert(
1266 _PATH_HOST_ED25519_KEY_FILE);
1267 sensitive_data.keys[3] = key_load_cert(
1268 _PATH_HOST_RSA_KEY_FILE);
1269 sensitive_data.keys[4] = key_load_cert(
1270 _PATH_HOST_DSA_KEY_FILE);
1271 #ifdef OPENSSL_HAS_ECC
1272 sensitive_data.keys[5] = key_load_public(
1273 _PATH_HOST_ECDSA_KEY_FILE, NULL);
1275 sensitive_data.keys[6] = key_load_public(
1276 _PATH_HOST_ED25519_KEY_FILE, NULL);
1277 sensitive_data.keys[7] = key_load_public(
1278 _PATH_HOST_RSA_KEY_FILE, NULL);
1279 sensitive_data.keys[8] = key_load_public(
1280 _PATH_HOST_DSA_KEY_FILE, NULL);
1281 sensitive_data.external_keysign = 1;
1285 * Get rid of any extra privileges that we may have. We will no
1286 * longer need them. Also, extra privileges could make it very hard
1287 * to read identity files and other non-world-readable files from the
1288 * user's home directory if it happens to be on a NFS volume where
1289 * root is mapped to nobody.
1291 if (original_effective_uid == 0) {
1293 permanently_set_uid(pw);
1297 * Now that we are back to our own permissions, create ~/.ssh
1298 * directory if it doesn't already exist.
1300 if (config == NULL) {
1301 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir,
1302 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
1303 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) {
1305 ssh_selinux_setfscreatecon(buf);
1307 if (mkdir(buf, 0700) < 0)
1308 error("Could not create directory '%.200s'.",
1311 ssh_selinux_setfscreatecon(NULL);
1315 /* load options.identity_files */
1316 load_public_identity_files();
1318 /* Expand ~ in known host file names. */
1319 tilde_expand_paths(options.system_hostfiles,
1320 options.num_system_hostfiles);
1321 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles);
1323 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
1324 signal(SIGCHLD, main_sigchld_handler);
1326 /* Log into the remote system. Never returns if the login fails. */
1327 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
1328 options.port, pw, timeout_ms);
1330 if (packet_connection_is_on_socket()) {
1331 verbose("Authenticated to %s ([%s]:%d).", host,
1332 get_remote_ipaddr(), get_remote_port());
1334 verbose("Authenticated to %s (via proxy).", host);
1337 /* We no longer need the private host keys. Clear them now. */
1338 if (sensitive_data.nkeys != 0) {
1339 for (i = 0; i < sensitive_data.nkeys; i++) {
1340 if (sensitive_data.keys[i] != NULL) {
1341 /* Destroys contents safely */
1342 debug3("clear hostkey %d", i);
1343 key_free(sensitive_data.keys[i]);
1344 sensitive_data.keys[i] = NULL;
1347 free(sensitive_data.keys);
1349 for (i = 0; i < options.num_identity_files; i++) {
1350 free(options.identity_files[i]);
1351 options.identity_files[i] = NULL;
1352 if (options.identity_keys[i]) {
1353 key_free(options.identity_keys[i]);
1354 options.identity_keys[i] = NULL;
1358 exit_status = compat20 ? ssh_session2() : ssh_session();
1361 if (options.control_path != NULL && muxserver_sock != -1)
1362 unlink(options.control_path);
1364 /* Kill ProxyCommand if it is running. */
1365 ssh_kill_proxy_command();
1371 control_persist_detach(void)
1376 debug("%s: backgrounding master process", __func__);
1379 * master (current process) into the background, and make the
1380 * foreground process a client of the backgrounded master.
1382 switch ((pid = fork())) {
1384 fatal("%s: fork: %s", __func__, strerror(errno));
1386 /* Child: master process continues mainloop */
1389 /* Parent: set up mux slave to connect to backgrounded master */
1390 debug2("%s: background process is %ld", __func__, (long)pid);
1391 stdin_null_flag = ostdin_null_flag;
1392 options.request_tty = orequest_tty;
1393 tty_flag = otty_flag;
1394 close(muxserver_sock);
1395 muxserver_sock = -1;
1396 options.control_master = SSHCTL_MASTER_NO;
1397 muxclient(options.control_path);
1398 /* muxclient() doesn't return on success. */
1399 fatal("Failed to connect to new control master");
1401 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
1402 error("%s: open(\"/dev/null\"): %s", __func__,
1405 if (dup2(devnull, STDIN_FILENO) == -1 ||
1406 dup2(devnull, STDOUT_FILENO) == -1)
1407 error("%s: dup2: %s", __func__, strerror(errno));
1408 if (devnull > STDERR_FILENO)
1412 setproctitle("%s [mux]", options.control_path);
1415 /* Do fork() after authentication. Used by "ssh -f" */
1419 if (need_controlpersist_detach)
1420 control_persist_detach();
1421 debug("forking to background");
1422 fork_after_authentication_flag = 0;
1423 if (daemon(1, 1) < 0)
1424 fatal("daemon() failed: %.200s", strerror(errno));
1427 /* Callback for remote forward global requests */
1429 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
1431 struct Forward *rfwd = (struct Forward *)ctxt;
1433 /* XXX verbose() on failure? */
1434 debug("remote forward %s for: listen %s%s%d, connect %s:%d",
1435 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1436 rfwd->listen_path ? rfwd->listen_path :
1437 rfwd->listen_host ? rfwd->listen_host : "",
1438 (rfwd->listen_path || rfwd->listen_host) ? ":" : "",
1439 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path :
1440 rfwd->connect_host, rfwd->connect_port);
1441 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) {
1442 if (type == SSH2_MSG_REQUEST_SUCCESS) {
1443 rfwd->allocated_port = packet_get_int();
1444 logit("Allocated port %u for remote forward to %s:%d",
1445 rfwd->allocated_port,
1446 rfwd->connect_host, rfwd->connect_port);
1447 channel_update_permitted_opens(rfwd->handle,
1448 rfwd->allocated_port);
1450 channel_update_permitted_opens(rfwd->handle, -1);
1454 if (type == SSH2_MSG_REQUEST_FAILURE) {
1455 if (options.exit_on_forward_failure) {
1456 if (rfwd->listen_path != NULL)
1457 fatal("Error: remote port forwarding failed "
1458 "for listen path %s", rfwd->listen_path);
1460 fatal("Error: remote port forwarding failed "
1461 "for listen port %d", rfwd->listen_port);
1463 if (rfwd->listen_path != NULL)
1464 logit("Warning: remote port forwarding failed "
1465 "for listen path %s", rfwd->listen_path);
1467 logit("Warning: remote port forwarding failed "
1468 "for listen port %d", rfwd->listen_port);
1471 if (++remote_forward_confirms_received == options.num_remote_forwards) {
1472 debug("All remote forwarding requests processed");
1473 if (fork_after_authentication_flag)
1479 client_cleanup_stdio_fwd(int id, void *arg)
1481 debug("stdio forwarding: done");
1486 ssh_stdio_confirm(int id, int success, void *arg)
1489 fatal("stdio forwarding failed");
1493 ssh_init_stdio_forwarding(void)
1498 if (stdio_forward_host == NULL)
1501 fatal("stdio forwarding require Protocol 2");
1503 debug3("%s: %s:%d", __func__, stdio_forward_host, stdio_forward_port);
1505 if ((in = dup(STDIN_FILENO)) < 0 ||
1506 (out = dup(STDOUT_FILENO)) < 0)
1507 fatal("channel_connect_stdio_fwd: dup() in/out failed");
1508 if ((c = channel_connect_stdio_fwd(stdio_forward_host,
1509 stdio_forward_port, in, out)) == NULL)
1510 fatal("%s: channel_connect_stdio_fwd failed", __func__);
1511 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0);
1512 channel_register_open_confirm(c->self, ssh_stdio_confirm, NULL);
1516 ssh_init_forwarding(void)
1521 /* Initiate local TCP/IP port forwardings. */
1522 for (i = 0; i < options.num_local_forwards; i++) {
1523 debug("Local connections to %.200s:%d forwarded to remote "
1524 "address %.200s:%d",
1525 (options.local_forwards[i].listen_path != NULL) ?
1526 options.local_forwards[i].listen_path :
1527 (options.local_forwards[i].listen_host == NULL) ?
1528 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") :
1529 options.local_forwards[i].listen_host,
1530 options.local_forwards[i].listen_port,
1531 (options.local_forwards[i].connect_path != NULL) ?
1532 options.local_forwards[i].connect_path :
1533 options.local_forwards[i].connect_host,
1534 options.local_forwards[i].connect_port);
1535 success += channel_setup_local_fwd_listener(
1536 &options.local_forwards[i], &options.fwd_opts);
1538 if (i > 0 && success != i && options.exit_on_forward_failure)
1539 fatal("Could not request local forwarding.");
1540 if (i > 0 && success == 0)
1541 error("Could not request local forwarding.");
1543 /* Initiate remote TCP/IP port forwardings. */
1544 for (i = 0; i < options.num_remote_forwards; i++) {
1545 debug("Remote connections from %.200s:%d forwarded to "
1546 "local address %.200s:%d",
1547 (options.remote_forwards[i].listen_path != NULL) ?
1548 options.remote_forwards[i].listen_path :
1549 (options.remote_forwards[i].listen_host == NULL) ?
1550 "LOCALHOST" : options.remote_forwards[i].listen_host,
1551 options.remote_forwards[i].listen_port,
1552 (options.remote_forwards[i].connect_path != NULL) ?
1553 options.remote_forwards[i].connect_path :
1554 options.remote_forwards[i].connect_host,
1555 options.remote_forwards[i].connect_port);
1556 options.remote_forwards[i].handle =
1557 channel_request_remote_forwarding(
1558 &options.remote_forwards[i]);
1559 if (options.remote_forwards[i].handle < 0) {
1560 if (options.exit_on_forward_failure)
1561 fatal("Could not request remote forwarding.");
1563 logit("Warning: Could not request remote "
1566 client_register_global_confirm(ssh_confirm_remote_forward,
1567 &options.remote_forwards[i]);
1571 /* Initiate tunnel forwarding. */
1572 if (options.tun_open != SSH_TUNMODE_NO) {
1573 if (client_request_tun_fwd(options.tun_open,
1574 options.tun_local, options.tun_remote) == -1) {
1575 if (options.exit_on_forward_failure)
1576 fatal("Could not request tunnel forwarding.");
1578 error("Could not request tunnel forwarding.");
1584 check_agent_present(void)
1588 if (options.forward_agent) {
1589 /* Clear agent forwarding if we don't have an agent. */
1590 if ((r = ssh_get_authentication_socket(NULL)) != 0) {
1591 options.forward_agent = 0;
1592 if (r != SSH_ERR_AGENT_NOT_PRESENT)
1593 debug("ssh_get_authentication_socket: %s",
1603 int interactive = 0;
1607 const char *display;
1609 /* Enable compression if requested. */
1610 if (options.compression) {
1611 debug("Requesting compression at level %d.",
1612 options.compression_level);
1614 if (options.compression_level < 1 ||
1615 options.compression_level > 9)
1616 fatal("Compression level must be from 1 (fast) to "
1619 /* Send the request. */
1620 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
1621 packet_put_int(options.compression_level);
1623 packet_write_wait();
1624 type = packet_read();
1625 if (type == SSH_SMSG_SUCCESS)
1626 packet_start_compression(options.compression_level);
1627 else if (type == SSH_SMSG_FAILURE)
1628 logit("Warning: Remote host refused compression.");
1630 packet_disconnect("Protocol error waiting for "
1631 "compression response.");
1633 /* Allocate a pseudo tty if appropriate. */
1635 debug("Requesting pty.");
1637 /* Start the packet. */
1638 packet_start(SSH_CMSG_REQUEST_PTY);
1640 /* Store TERM in the packet. There is no limit on the
1641 length of the string. */
1642 cp = getenv("TERM");
1645 packet_put_cstring(cp);
1647 /* Store window size in the packet. */
1648 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
1649 memset(&ws, 0, sizeof(ws));
1650 packet_put_int((u_int)ws.ws_row);
1651 packet_put_int((u_int)ws.ws_col);
1652 packet_put_int((u_int)ws.ws_xpixel);
1653 packet_put_int((u_int)ws.ws_ypixel);
1655 /* Store tty modes in the packet. */
1656 tty_make_modes(fileno(stdin), NULL);
1658 /* Send the packet, and wait for it to leave. */
1660 packet_write_wait();
1662 /* Read response from the server. */
1663 type = packet_read();
1664 if (type == SSH_SMSG_SUCCESS) {
1667 } else if (type == SSH_SMSG_FAILURE)
1668 logit("Warning: Remote host failed or refused to "
1669 "allocate a pseudo tty.");
1671 packet_disconnect("Protocol error waiting for pty "
1672 "request response.");
1674 /* Request X11 forwarding if enabled and DISPLAY is set. */
1675 display = getenv("DISPLAY");
1676 if (options.forward_x11 && display != NULL) {
1678 /* Get reasonable local authentication information. */
1679 client_x11_get_proto(display, options.xauth_location,
1680 options.forward_x11_trusted,
1681 options.forward_x11_timeout,
1683 /* Request forwarding with authentication spoofing. */
1684 debug("Requesting X11 forwarding with authentication "
1686 x11_request_forwarding_with_spoofing(0, display, proto,
1688 /* Read response from the server. */
1689 type = packet_read();
1690 if (type == SSH_SMSG_SUCCESS) {
1692 } else if (type == SSH_SMSG_FAILURE) {
1693 logit("Warning: Remote host denied X11 forwarding.");
1695 packet_disconnect("Protocol error waiting for X11 "
1699 /* Tell the packet module whether this is an interactive session. */
1700 packet_set_interactive(interactive,
1701 options.ip_qos_interactive, options.ip_qos_bulk);
1703 /* Request authentication agent forwarding if appropriate. */
1704 check_agent_present();
1706 if (options.forward_agent) {
1707 debug("Requesting authentication agent forwarding.");
1708 auth_request_forwarding();
1710 /* Read response from the server. */
1711 type = packet_read();
1713 if (type != SSH_SMSG_SUCCESS)
1714 logit("Warning: Remote host denied authentication agent forwarding.");
1717 /* Initiate port forwardings. */
1718 ssh_init_stdio_forwarding();
1719 ssh_init_forwarding();
1721 /* Execute a local command */
1722 if (options.local_command != NULL &&
1723 options.permit_local_command)
1724 ssh_local_cmd(options.local_command);
1727 * If requested and we are not interested in replies to remote
1728 * forwarding requests, then let ssh continue in the background.
1730 if (fork_after_authentication_flag) {
1731 if (options.exit_on_forward_failure &&
1732 options.num_remote_forwards > 0) {
1733 debug("deferring postauth fork until remote forward "
1734 "confirmation received");
1740 * If a command was specified on the command line, execute the
1741 * command now. Otherwise request the server to start a shell.
1743 if (buffer_len(&command) > 0) {
1744 int len = buffer_len(&command);
1747 debug("Sending command: %.*s", len,
1748 (u_char *)buffer_ptr(&command));
1749 packet_start(SSH_CMSG_EXEC_CMD);
1750 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1752 packet_write_wait();
1754 debug("Requesting shell.");
1755 packet_start(SSH_CMSG_EXEC_SHELL);
1757 packet_write_wait();
1760 /* Enter the interactive session. */
1761 return client_loop(have_tty, tty_flag ?
1762 options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1765 /* request pty/x11/agent/tcpfwd/shell for channel */
1767 ssh_session2_setup(int id, int success, void *arg)
1769 extern char **environ;
1770 const char *display;
1771 int interactive = tty_flag;
1774 return; /* No need for error message, channels code sens one */
1776 display = getenv("DISPLAY");
1777 if (options.forward_x11 && display != NULL) {
1779 /* Get reasonable local authentication information. */
1780 client_x11_get_proto(display, options.xauth_location,
1781 options.forward_x11_trusted,
1782 options.forward_x11_timeout, &proto, &data);
1783 /* Request forwarding with authentication spoofing. */
1784 debug("Requesting X11 forwarding with authentication "
1786 x11_request_forwarding_with_spoofing(id, display, proto,
1788 client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
1789 /* XXX exit_on_forward_failure */
1793 check_agent_present();
1794 if (options.forward_agent) {
1795 debug("Requesting authentication agent forwarding.");
1796 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1800 /* Tell the packet module whether this is an interactive session. */
1801 packet_set_interactive(interactive,
1802 options.ip_qos_interactive, options.ip_qos_bulk);
1804 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1805 NULL, fileno(stdin), &command, environ);
1808 /* open new channel for a session */
1810 ssh_session2_open(void)
1813 int window, packetmax, in, out, err;
1815 if (stdin_null_flag) {
1816 in = open(_PATH_DEVNULL, O_RDONLY);
1818 in = dup(STDIN_FILENO);
1820 out = dup(STDOUT_FILENO);
1821 err = dup(STDERR_FILENO);
1823 if (in < 0 || out < 0 || err < 0)
1824 fatal("dup() in/out/err failed");
1826 /* enable nonblocking unless tty */
1834 window = CHAN_SES_WINDOW_DEFAULT;
1835 packetmax = CHAN_SES_PACKET_DEFAULT;
1841 "session", SSH_CHANNEL_OPENING, in, out, err,
1842 window, packetmax, CHAN_EXTENDED_WRITE,
1843 "client-session", /*nonblock*/0);
1845 debug3("ssh_session2_open: channel_new: %d", c->self);
1847 channel_send_open(c->self);
1849 channel_register_open_confirm(c->self,
1850 ssh_session2_setup, NULL);
1860 /* XXX should be pre-session */
1861 if (!options.control_persist)
1862 ssh_init_stdio_forwarding();
1863 ssh_init_forwarding();
1865 /* Start listening for multiplex clients */
1869 * If we are in control persist mode and have a working mux listen
1870 * socket, then prepare to background ourselves and have a foreground
1871 * client attach as a control slave.
1872 * NB. we must save copies of the flags that we override for
1873 * the backgrounding, since we defer attachment of the slave until
1874 * after the connection is fully established (in particular,
1875 * async rfwd replies have been received for ExitOnForwardFailure).
1877 if (options.control_persist && muxserver_sock != -1) {
1878 ostdin_null_flag = stdin_null_flag;
1879 ono_shell_flag = no_shell_flag;
1880 orequest_tty = options.request_tty;
1881 otty_flag = tty_flag;
1882 stdin_null_flag = 1;
1885 if (!fork_after_authentication_flag)
1886 need_controlpersist_detach = 1;
1887 fork_after_authentication_flag = 1;
1890 * ControlPersist mux listen socket setup failed, attempt the
1891 * stdio forward setup that we skipped earlier.
1893 if (options.control_persist && muxserver_sock == -1)
1894 ssh_init_stdio_forwarding();
1896 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1897 id = ssh_session2_open();
1899 packet_set_interactive(
1900 options.control_master == SSHCTL_MASTER_NO,
1901 options.ip_qos_interactive, options.ip_qos_bulk);
1904 /* If we don't expect to open a new session, then disallow it */
1905 if (options.control_master == SSHCTL_MASTER_NO &&
1906 (datafellows & SSH_NEW_OPENSSH)) {
1907 debug("Requesting no-more-sessions@openssh.com");
1908 packet_start(SSH2_MSG_GLOBAL_REQUEST);
1909 packet_put_cstring("no-more-sessions@openssh.com");
1914 /* Execute a local command */
1915 if (options.local_command != NULL &&
1916 options.permit_local_command)
1917 ssh_local_cmd(options.local_command);
1920 * If requested and we are not interested in replies to remote
1921 * forwarding requests, then let ssh continue in the background.
1923 if (fork_after_authentication_flag) {
1924 if (options.exit_on_forward_failure &&
1925 options.num_remote_forwards > 0) {
1926 debug("deferring postauth fork until remote forward "
1927 "confirmation received");
1932 return client_loop(tty_flag, tty_flag ?
1933 options.escape_char : SSH_ESCAPECHAR_NONE, id);
1937 load_public_identity_files(void)
1939 char *filename, *cp, thishost[NI_MAXHOST];
1940 char *pwdir = NULL, *pwname = NULL;
1945 char *identity_files[SSH_MAX_IDENTITY_FILES];
1946 Key *identity_keys[SSH_MAX_IDENTITY_FILES];
1947 #ifdef ENABLE_PKCS11
1953 memset(identity_files, 0, sizeof(identity_files));
1954 memset(identity_keys, 0, sizeof(identity_keys));
1956 #ifdef ENABLE_PKCS11
1957 if (options.pkcs11_provider != NULL &&
1958 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1959 (pkcs11_init(!options.batch_mode) == 0) &&
1960 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL,
1962 for (i = 0; i < nkeys; i++) {
1963 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
1967 identity_keys[n_ids] = keys[i];
1968 identity_files[n_ids] =
1969 xstrdup(options.pkcs11_provider); /* XXX */
1974 #endif /* ENABLE_PKCS11 */
1975 if ((pw = getpwuid(original_real_uid)) == NULL)
1976 fatal("load_public_identity_files: getpwuid failed");
1977 pwname = xstrdup(pw->pw_name);
1978 pwdir = xstrdup(pw->pw_dir);
1979 if (gethostname(thishost, sizeof(thishost)) == -1)
1980 fatal("load_public_identity_files: gethostname: %s",
1982 for (i = 0; i < options.num_identity_files; i++) {
1983 if (n_ids >= SSH_MAX_IDENTITY_FILES ||
1984 strcasecmp(options.identity_files[i], "none") == 0) {
1985 free(options.identity_files[i]);
1988 cp = tilde_expand_filename(options.identity_files[i],
1990 filename = percent_expand(cp, "d", pwdir,
1991 "u", pwname, "l", thishost, "h", host,
1992 "r", options.user, (char *)NULL);
1994 public = key_load_public(filename, NULL);
1995 debug("identity file %s type %d", filename,
1996 public ? public->type : -1);
1997 free(options.identity_files[i]);
1998 identity_files[n_ids] = filename;
1999 identity_keys[n_ids] = public;
2001 if (++n_ids >= SSH_MAX_IDENTITY_FILES)
2004 /* Try to add the certificate variant too */
2005 xasprintf(&cp, "%s-cert", filename);
2006 public = key_load_public(cp, NULL);
2007 debug("identity file %s type %d", cp,
2008 public ? public->type : -1);
2009 if (public == NULL) {
2013 if (!key_is_cert(public)) {
2014 debug("%s: key %s type %s is not a certificate",
2015 __func__, cp, key_type(public));
2020 identity_keys[n_ids] = public;
2021 /* point to the original path, most likely the private key */
2022 identity_files[n_ids] = xstrdup(filename);
2025 options.num_identity_files = n_ids;
2026 memcpy(options.identity_files, identity_files, sizeof(identity_files));
2027 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys));
2029 explicit_bzero(pwname, strlen(pwname));
2031 explicit_bzero(pwdir, strlen(pwdir));
2036 main_sigchld_handler(int sig)
2038 int save_errno = errno;
2042 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
2043 (pid < 0 && errno == EINTR))
2046 signal(sig, main_sigchld_handler);