2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * Ssh client program. This program can be used to log into a remote machine.
6 * The software supports strong authentication, encryption, and forwarding
7 * of X11, TCP/IP, and authentication connections.
9 * As far as I am concerned, the code I have written for this software
10 * can be used freely for any purpose. Any derived versions of this
11 * software must be clearly marked as such, and if the derived work is
12 * incompatible with the protocol description in the RFC file, it must be
13 * called by a name other than "ssh" or "Secure Shell".
15 * Copyright (c) 1999 Niels Provos. All rights reserved.
16 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved.
18 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
19 * in Canada (German citizen).
21 * Redistribution and use in source and binary forms, with or without
22 * modification, are permitted provided that the following conditions
24 * 1. Redistributions of source code must retain the above copyright
25 * notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 * notice, this list of conditions and the following disclaimer in the
28 * documentation and/or other materials provided with the distribution.
30 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
43 RCSID("$OpenBSD: ssh.c,v 1.257 2005/12/20 04:41:07 dtucker Exp $");
45 #include <openssl/evp.h>
46 #include <openssl/err.h>
61 #include "pathnames.h"
63 #include "clientloop.h"
66 #include "sshconnect.h"
73 #include "monitor_fdpass.h"
80 extern char *__progname;
82 /* Flag indicating whether debug mode is on. This can be set on the command line. */
85 /* Flag indicating whether a tty should be allocated */
88 int force_tty_flag = 0;
90 /* don't exec a shell */
91 int no_shell_flag = 0;
94 * Flag indicating that nothing should be read from stdin. This can be set
95 * on the command line.
97 int stdin_null_flag = 0;
100 * Flag indicating that ssh should fork after authentication. This is useful
101 * so that the passphrase can be entered manually, and then ssh goes to the
104 int fork_after_authentication_flag = 0;
107 * General data structure for command line options and options configurable
108 * in configuration files. See readconf.h.
112 /* optional user configfile */
116 * Name of the host we are connecting to. This is the name given on the
117 * command line, or the HostName specified for the user-supplied name in a
118 * configuration file.
122 /* socket address the host resolves to */
123 struct sockaddr_storage hostaddr;
125 /* Private host keys. */
126 Sensitive sensitive_data;
128 /* Original real UID. */
129 uid_t original_real_uid;
130 uid_t original_effective_uid;
132 /* command to be executed */
135 /* Should we execute a command or invoke a subsystem? */
136 int subsystem_flag = 0;
138 /* # of replies received for global requests */
139 static int client_global_request_id = 0;
141 /* pid of proxycommand child process */
142 pid_t proxy_command_pid = 0;
144 /* fd to control socket */
147 /* Multiplexing control command */
148 static u_int mux_command = 0;
150 /* Only used in control client mode */
151 volatile sig_atomic_t control_client_terminate = 0;
152 u_int control_server_pid = 0;
154 /* Prints a help message to the user. This function never returns. */
160 "usage: ssh [-1246AaCfgkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n"
161 " [-D [bind_address:]port] [-e escape_char] [-F configfile]\n"
162 " [-i identity_file] [-L [bind_address:]port:host:hostport]\n"
163 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
164 " [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
165 " [-w tunnel:tunnel] [user@]hostname [command]\n"
170 static int ssh_session(void);
171 static int ssh_session2(void);
172 static void load_public_identity_files(void);
173 static void control_client(const char *path);
176 * Main program for the ssh client.
179 main(int ac, char **av)
181 int i, opt, exit_status;
182 char *p, *cp, *line, buf[256];
186 extern int optind, optreset;
191 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
194 __progname = ssh_get_progname(av[0]);
199 * Save the original real uid. It will be needed later (uid-swapping
200 * may clobber the real uid).
202 original_real_uid = getuid();
203 original_effective_uid = geteuid();
206 * Use uid-swapping to give up root privileges for the duration of
207 * option processing. We will re-instantiate the rights when we are
208 * ready to create the privileged port, and will permanently drop
209 * them when the port has been created (actually, when the connection
210 * has been made, as we may need to create the port several times).
214 #ifdef HAVE_SETRLIMIT
215 /* If we are installed setuid root be careful to not drop core. */
216 if (original_real_uid != original_effective_uid) {
218 rlim.rlim_cur = rlim.rlim_max = 0;
219 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
220 fatal("setrlimit failed: %.100s", strerror(errno));
224 pw = getpwuid(original_real_uid);
226 logit("You don't exist, go away!");
229 /* Take a copy of the returned structure. */
233 * Set our umask to something reasonable, as some files are created
234 * with the default umask. This will make them world-readable but
235 * writable only by the owner, which is ok for all files for which we
236 * don't set the modes explicitly.
240 /* Initialize option structure to indicate that no values have been set. */
241 initialize_options(&options);
243 /* Parse command-line arguments. */
247 while ((opt = getopt(ac, av,
248 "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNO:PR:S:TVw:XY")) != -1) {
251 options.protocol = SSH_PROTO_1;
254 options.protocol = SSH_PROTO_2;
257 options.address_family = AF_INET;
260 options.address_family = AF_INET6;
266 fork_after_authentication_flag = 1;
270 options.forward_x11 = 0;
273 options.forward_x11 = 1;
276 options.forward_x11 = 1;
277 options.forward_x11_trusted = 1;
280 options.gateway_ports = 1;
283 if (strcmp(optarg, "check") == 0)
284 mux_command = SSHMUX_COMMAND_ALIVE_CHECK;
285 else if (strcmp(optarg, "exit") == 0)
286 mux_command = SSHMUX_COMMAND_TERMINATE;
288 fatal("Invalid multiplex command.");
290 case 'P': /* deprecated */
291 options.use_privileged_port = 0;
294 options.forward_agent = 0;
297 options.forward_agent = 1;
300 options.gss_deleg_creds = 0;
303 if (stat(optarg, &st) < 0) {
304 fprintf(stderr, "Warning: Identity file %s "
305 "not accessible: %s.\n", optarg,
309 if (options.num_identity_files >=
310 SSH_MAX_IDENTITY_FILES)
311 fatal("Too many identity files specified "
312 "(max %d)", SSH_MAX_IDENTITY_FILES);
313 options.identity_files[options.num_identity_files++] =
318 options.smartcard_device = xstrdup(optarg);
320 fprintf(stderr, "no support for smartcards.\n");
329 if (debug_flag == 0) {
331 options.log_level = SYSLOG_LEVEL_DEBUG1;
333 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
339 fprintf(stderr, "%s, %s\n",
340 SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
345 if (options.tun_open == -1)
346 options.tun_open = SSH_TUNMODE_DEFAULT;
347 options.tun_local = a2tun(optarg, &options.tun_remote);
348 if (options.tun_local == SSH_TUNID_ERR) {
349 fprintf(stderr, "Bad tun device '%s'\n", optarg);
354 options.log_level = SYSLOG_LEVEL_QUIET;
357 if (optarg[0] == '^' && optarg[2] == 0 &&
358 (u_char) optarg[1] >= 64 &&
359 (u_char) optarg[1] < 128)
360 options.escape_char = (u_char) optarg[1] & 31;
361 else if (strlen(optarg) == 1)
362 options.escape_char = (u_char) optarg[0];
363 else if (strcmp(optarg, "none") == 0)
364 options.escape_char = SSH_ESCAPECHAR_NONE;
366 fprintf(stderr, "Bad escape character '%s'.\n",
372 if (ciphers_valid(optarg)) {
374 options.ciphers = xstrdup(optarg);
375 options.cipher = SSH_CIPHER_INVALID;
378 options.cipher = cipher_number(optarg);
379 if (options.cipher == -1) {
381 "Unknown cipher type '%s'\n",
385 if (options.cipher == SSH_CIPHER_3DES)
386 options.ciphers = "3des-cbc";
387 else if (options.cipher == SSH_CIPHER_BLOWFISH)
388 options.ciphers = "blowfish-cbc";
390 options.ciphers = (char *)-1;
394 if (mac_valid(optarg))
395 options.macs = xstrdup(optarg);
397 fprintf(stderr, "Unknown mac type '%s'\n",
403 if (options.control_master == SSHCTL_MASTER_YES)
404 options.control_master = SSHCTL_MASTER_ASK;
406 options.control_master = SSHCTL_MASTER_YES;
409 options.port = a2port(optarg);
410 if (options.port == 0) {
411 fprintf(stderr, "Bad port '%s'\n", optarg);
416 options.user = optarg;
420 if (parse_forward(&fwd, optarg))
421 add_local_forward(&options, &fwd);
424 "Bad local forwarding specification '%s'\n",
431 if (parse_forward(&fwd, optarg)) {
432 add_remote_forward(&options, &fwd);
435 "Bad remote forwarding specification "
442 cp = p = xstrdup(optarg);
443 memset(&fwd, '\0', sizeof(fwd));
444 fwd.connect_host = "socks";
445 if ((fwd.listen_host = hpdelim(&cp)) == NULL) {
446 fprintf(stderr, "Bad dynamic forwarding "
447 "specification '%.100s'\n", optarg);
451 fwd.listen_port = a2port(cp);
452 fwd.listen_host = cleanhostname(fwd.listen_host);
454 fwd.listen_port = a2port(fwd.listen_host);
455 fwd.listen_host = NULL;
458 if (fwd.listen_port == 0) {
459 fprintf(stderr, "Bad dynamic port '%s'\n",
463 add_local_forward(&options, &fwd);
468 options.compression = 1;
473 options.none_switch = 0;
477 options.none_switch = 0;
481 line = xstrdup(optarg);
482 if (process_config_line(&options, host ? host : "",
483 line, "command-line", 0, &dummy) != 0)
491 if (options.control_path != NULL)
492 free(options.control_path);
493 options.control_path = xstrdup(optarg);
496 options.bind_address = optarg;
502 /* make sure we can't turn on the none_switch */
503 /* if they try to force a no tty flag on a tty session */
505 options.none_switch = 1;
517 if (ac > 0 && !host && **av != '-') {
518 if (strrchr(*av, '@')) {
520 cp = strrchr(p, '@');
521 if (cp == NULL || cp == p)
529 optind = optreset = 1;
535 /* Check that we got a host name. */
539 SSLeay_add_all_algorithms();
540 ERR_load_crypto_strings();
542 /* Initialize the command to execute on remote host. */
543 buffer_init(&command);
546 * Save the command to execute on the remote host in a buffer. There
547 * is no limit on the length of the command, except by the maximum
548 * packet size. Also sets the tty flag if there is no command.
551 /* No command specified - execute shell on a tty. */
553 if (subsystem_flag) {
555 "You must specify a subsystem to invoke.\n");
559 /* A command has been specified. Store it into the buffer. */
560 for (i = 0; i < ac; i++) {
562 buffer_append(&command, " ", 1);
563 buffer_append(&command, av[i], strlen(av[i]));
567 /* Cannot fork to background if no command. */
568 if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag)
569 fatal("Cannot fork into background without a command to execute.");
571 /* Allocate a tty by default if no command specified. */
572 if (buffer_len(&command) == 0)
578 /* Do not allocate a tty if stdin is not a tty. */
579 if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
581 logit("Pseudo-terminal will not be allocated because stdin is not a terminal.");
586 * Initialize "log" output. Since we are the client all output
587 * actually goes to stderr.
589 log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
590 SYSLOG_FACILITY_USER, 1);
593 * Read per-user configuration file. Ignore the system wide config
594 * file if the user specifies a config file on the command line.
596 if (config != NULL) {
597 if (!read_config_file(config, host, &options, 0))
598 fatal("Can't open user config file %.100s: "
599 "%.100s", config, strerror(errno));
602 * Since the config file parsing code aborts if it sees
603 * options it doesn't recognize, allow users to put
604 * options specific to compile-time add-ons in alternate
605 * config files so their primary config file will
606 * interoperate SSH versions that don't support those
610 snprintf(buf, sizeof buf, "%.100s/%.100s.gssapi", pw->pw_dir,
611 _PATH_SSH_USER_CONFFILE);
612 (void)read_config_file(buf, host, &options, 1);
614 snprintf(buf, sizeof buf, "%.100s/%.100s.gsi", pw->pw_dir,
615 _PATH_SSH_USER_CONFFILE);
616 (void)read_config_file(buf, host, &options, 1);
619 snprintf(buf, sizeof buf, "%.100s/%.100s.krb", pw->pw_dir,
620 _PATH_SSH_USER_CONFFILE);
621 (void)read_config_file(buf, host, &options, 1);
624 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
625 _PATH_SSH_USER_CONFFILE);
626 (void)read_config_file(buf, host, &options, 1);
628 /* Read systemwide configuration file after use config. */
629 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
633 /* Fill configuration defaults. */
634 fill_default_options(&options);
636 channel_set_af(options.address_family);
639 log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1);
643 if (options.user == NULL) {
644 options.user = xstrdup(pw->pw_name);
645 options.implicit = 1;
647 else options.implicit = 0;
649 if (options.hostname != NULL)
650 host = options.hostname;
652 /* force lowercase for hostkey matching */
653 if (options.host_key_alias != NULL) {
654 for (p = options.host_key_alias; *p; p++)
659 /* Get default port if port has not been set. */
660 if (options.port == 0) {
661 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
662 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
665 if (options.proxy_command != NULL &&
666 strcmp(options.proxy_command, "none") == 0)
667 options.proxy_command = NULL;
668 if (options.control_path != NULL &&
669 strcmp(options.control_path, "none") == 0)
670 options.control_path = NULL;
672 if (options.control_path != NULL) {
673 snprintf(buf, sizeof(buf), "%d", options.port);
674 cp = tilde_expand_filename(options.control_path,
676 options.control_path = percent_expand(cp, "p", buf, "h", host,
677 "r", options.user, (char *)NULL);
680 if (mux_command != 0 && options.control_path == NULL)
681 fatal("No ControlPath specified for \"-O\" command");
682 if (options.control_path != NULL)
683 control_client(options.control_path);
685 /* Open a connection to the remote host. */
686 if (ssh_connect(host, &hostaddr, options.port,
687 options.address_family, options.connection_attempts,
689 options.use_privileged_port,
691 original_effective_uid == 0 && options.use_privileged_port,
693 options.proxy_command) != 0)
697 * If we successfully made the connection, load the host private key
698 * in case we will need it later for combined rsa-rhosts
699 * authentication. This must be done before releasing extra
700 * privileges, because the file is only readable by root.
701 * If we cannot access the private keys, load the public keys
702 * instead and try to execute the ssh-keysign helper instead.
704 sensitive_data.nkeys = 0;
705 sensitive_data.keys = NULL;
706 sensitive_data.external_keysign = 0;
707 if (options.rhosts_rsa_authentication ||
708 options.hostbased_authentication) {
709 sensitive_data.nkeys = 3;
710 sensitive_data.keys = xmalloc(sensitive_data.nkeys *
714 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
715 _PATH_HOST_KEY_FILE, "", NULL);
716 sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
717 _PATH_HOST_DSA_KEY_FILE, "", NULL);
718 sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
719 _PATH_HOST_RSA_KEY_FILE, "", NULL);
722 if (options.hostbased_authentication == 1 &&
723 sensitive_data.keys[0] == NULL &&
724 sensitive_data.keys[1] == NULL &&
725 sensitive_data.keys[2] == NULL) {
726 sensitive_data.keys[1] = key_load_public(
727 _PATH_HOST_DSA_KEY_FILE, NULL);
728 sensitive_data.keys[2] = key_load_public(
729 _PATH_HOST_RSA_KEY_FILE, NULL);
730 sensitive_data.external_keysign = 1;
734 * Get rid of any extra privileges that we may have. We will no
735 * longer need them. Also, extra privileges could make it very hard
736 * to read identity files and other non-world-readable files from the
737 * user's home directory if it happens to be on a NFS volume where
738 * root is mapped to nobody.
740 if (original_effective_uid == 0) {
742 permanently_set_uid(pw);
746 * Now that we are back to our own permissions, create ~/.ssh
747 * directory if it doesn't already exist.
749 snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
750 if (stat(buf, &st) < 0)
751 if (mkdir(buf, 0700) < 0)
752 error("Could not create directory '%.200s'.", buf);
754 /* load options.identity_files */
755 load_public_identity_files();
757 /* Expand ~ in known host file names. */
759 options.system_hostfile =
760 tilde_expand_filename(options.system_hostfile, original_real_uid);
761 options.user_hostfile =
762 tilde_expand_filename(options.user_hostfile, original_real_uid);
763 options.system_hostfile2 =
764 tilde_expand_filename(options.system_hostfile2, original_real_uid);
765 options.user_hostfile2 =
766 tilde_expand_filename(options.user_hostfile2, original_real_uid);
768 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
770 /* Log into the remote system. This never returns if the login fails. */
771 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw);
773 /* We no longer need the private host keys. Clear them now. */
774 if (sensitive_data.nkeys != 0) {
775 for (i = 0; i < sensitive_data.nkeys; i++) {
776 if (sensitive_data.keys[i] != NULL) {
777 /* Destroys contents safely */
778 debug3("clear hostkey %d", i);
779 key_free(sensitive_data.keys[i]);
780 sensitive_data.keys[i] = NULL;
783 xfree(sensitive_data.keys);
785 for (i = 0; i < options.num_identity_files; i++) {
786 if (options.identity_files[i]) {
787 xfree(options.identity_files[i]);
788 options.identity_files[i] = NULL;
790 if (options.identity_keys[i]) {
791 key_free(options.identity_keys[i]);
792 options.identity_keys[i] = NULL;
796 exit_status = compat20 ? ssh_session2() : ssh_session();
799 if (options.control_path != NULL && control_fd != -1)
800 unlink(options.control_path);
803 * Send SIGHUP to proxy command if used. We don't wait() in
804 * case it hangs and instead rely on init to reap the child
806 if (proxy_command_pid > 1)
807 kill(proxy_command_pid, SIGHUP);
813 ssh_init_forwarding(void)
818 /* Initiate local TCP/IP port forwardings. */
819 for (i = 0; i < options.num_local_forwards; i++) {
820 debug("Local connections to %.200s:%d forwarded to remote "
822 (options.local_forwards[i].listen_host == NULL) ?
823 (options.gateway_ports ? "*" : "LOCALHOST") :
824 options.local_forwards[i].listen_host,
825 options.local_forwards[i].listen_port,
826 options.local_forwards[i].connect_host,
827 options.local_forwards[i].connect_port);
828 success += channel_setup_local_fwd_listener(
829 options.local_forwards[i].listen_host,
830 options.local_forwards[i].listen_port,
831 options.local_forwards[i].connect_host,
832 options.local_forwards[i].connect_port,
833 options.gateway_ports, options.hpn_disabled,
834 options.hpn_buffer_size);
836 if (i > 0 && success == 0)
837 error("Could not request local forwarding.");
839 /* Initiate remote TCP/IP port forwardings. */
840 for (i = 0; i < options.num_remote_forwards; i++) {
841 debug("Remote connections from %.200s:%d forwarded to "
842 "local address %.200s:%d",
843 (options.remote_forwards[i].listen_host == NULL) ?
844 "LOCALHOST" : options.remote_forwards[i].listen_host,
845 options.remote_forwards[i].listen_port,
846 options.remote_forwards[i].connect_host,
847 options.remote_forwards[i].connect_port);
848 channel_request_remote_forwarding(
849 options.remote_forwards[i].listen_host,
850 options.remote_forwards[i].listen_port,
851 options.remote_forwards[i].connect_host,
852 options.remote_forwards[i].connect_port);
857 check_agent_present(void)
859 if (options.forward_agent) {
860 /* Clear agent forwarding if we don't have an agent. */
861 if (!ssh_agent_present())
862 options.forward_agent = 0;
876 /* Enable compression if requested. */
877 if (options.compression) {
878 debug("Requesting compression at level %d.", options.compression_level);
880 if (options.compression_level < 1 || options.compression_level > 9)
881 fatal("Compression level must be from 1 (fast) to 9 (slow, best).");
883 /* Send the request. */
884 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
885 packet_put_int(options.compression_level);
888 type = packet_read();
889 if (type == SSH_SMSG_SUCCESS)
890 packet_start_compression(options.compression_level);
891 else if (type == SSH_SMSG_FAILURE)
892 logit("Warning: Remote host refused compression.");
894 packet_disconnect("Protocol error waiting for compression response.");
896 /* Allocate a pseudo tty if appropriate. */
898 debug("Requesting pty.");
900 /* Start the packet. */
901 packet_start(SSH_CMSG_REQUEST_PTY);
903 /* Store TERM in the packet. There is no limit on the
904 length of the string. */
908 packet_put_cstring(cp);
910 /* Store window size in the packet. */
911 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
912 memset(&ws, 0, sizeof(ws));
913 packet_put_int(ws.ws_row);
914 packet_put_int(ws.ws_col);
915 packet_put_int(ws.ws_xpixel);
916 packet_put_int(ws.ws_ypixel);
918 /* Store tty modes in the packet. */
919 tty_make_modes(fileno(stdin), NULL);
921 /* Send the packet, and wait for it to leave. */
925 /* Read response from the server. */
926 type = packet_read();
927 if (type == SSH_SMSG_SUCCESS) {
930 } else if (type == SSH_SMSG_FAILURE)
931 logit("Warning: Remote host failed or refused to allocate a pseudo tty.");
933 packet_disconnect("Protocol error waiting for pty request response.");
935 /* Request X11 forwarding if enabled and DISPLAY is set. */
936 display = getenv("DISPLAY");
937 if (options.forward_x11 && display != NULL) {
939 /* Get reasonable local authentication information. */
940 client_x11_get_proto(display, options.xauth_location,
941 options.forward_x11_trusted, &proto, &data);
942 /* Request forwarding with authentication spoofing. */
943 debug("Requesting X11 forwarding with authentication spoofing.");
944 x11_request_forwarding_with_spoofing(0, display, proto, data);
946 /* Read response from the server. */
947 type = packet_read();
948 if (type == SSH_SMSG_SUCCESS) {
950 } else if (type == SSH_SMSG_FAILURE) {
951 logit("Warning: Remote host denied X11 forwarding.");
953 packet_disconnect("Protocol error waiting for X11 forwarding");
956 /* Tell the packet module whether this is an interactive session. */
957 packet_set_interactive(interactive);
959 /* Request authentication agent forwarding if appropriate. */
960 check_agent_present();
962 if (options.forward_agent) {
963 debug("Requesting authentication agent forwarding.");
964 auth_request_forwarding();
966 /* Read response from the server. */
967 type = packet_read();
969 if (type != SSH_SMSG_SUCCESS)
970 logit("Warning: Remote host denied authentication agent forwarding.");
973 /* Initiate port forwardings. */
974 ssh_init_forwarding();
976 /* If requested, let ssh continue in the background. */
977 if (fork_after_authentication_flag)
978 if (daemon(1, 1) < 0)
979 fatal("daemon() failed: %.200s", strerror(errno));
982 * If a command was specified on the command line, execute the
983 * command now. Otherwise request the server to start a shell.
985 if (buffer_len(&command) > 0) {
986 int len = buffer_len(&command);
989 debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command));
990 packet_start(SSH_CMSG_EXEC_CMD);
991 packet_put_string(buffer_ptr(&command), buffer_len(&command));
995 debug("Requesting shell.");
996 packet_start(SSH_CMSG_EXEC_SHELL);
1001 /* Enter the interactive session. */
1002 return client_loop(have_tty, tty_flag ?
1003 options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1007 ssh_subsystem_reply(int type, u_int32_t seq, void *ctxt)
1011 id = packet_get_int();
1012 len = buffer_len(&command);
1016 if (type == SSH2_MSG_CHANNEL_FAILURE)
1017 fatal("Request for subsystem '%.*s' failed on channel %d",
1018 len, (u_char *)buffer_ptr(&command), id);
1022 client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt)
1026 i = client_global_request_id++;
1027 if (i >= options.num_remote_forwards)
1029 debug("remote forward %s for: listen %d, connect %s:%d",
1030 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1031 options.remote_forwards[i].listen_port,
1032 options.remote_forwards[i].connect_host,
1033 options.remote_forwards[i].connect_port);
1034 if (type == SSH2_MSG_REQUEST_FAILURE)
1035 logit("Warning: remote port forwarding failed for listen "
1036 "port %d", options.remote_forwards[i].listen_port);
1040 ssh_control_listener(void)
1042 struct sockaddr_un addr;
1046 if (options.control_path == NULL ||
1047 options.control_master == SSHCTL_MASTER_NO)
1050 debug("setting up multiplex master socket");
1052 memset(&addr, '\0', sizeof(addr));
1053 addr.sun_family = AF_UNIX;
1054 addr_len = offsetof(struct sockaddr_un, sun_path) +
1055 strlen(options.control_path) + 1;
1057 if (strlcpy(addr.sun_path, options.control_path,
1058 sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1059 fatal("ControlPath too long");
1061 if ((control_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1062 fatal("%s socket(): %s", __func__, strerror(errno));
1064 old_umask = umask(0177);
1065 if (bind(control_fd, (struct sockaddr*)&addr, addr_len) == -1) {
1067 if (errno == EINVAL || errno == EADDRINUSE)
1068 fatal("ControlSocket %s already exists",
1069 options.control_path);
1071 fatal("%s bind(): %s", __func__, strerror(errno));
1075 if (listen(control_fd, 64) == -1)
1076 fatal("%s listen(): %s", __func__, strerror(errno));
1078 set_nonblock(control_fd);
1081 /* request pty/x11/agent/tcpfwd/shell for channel */
1083 ssh_session2_setup(int id, void *arg)
1085 extern char **environ;
1086 const char *display;
1087 int interactive = tty_flag;
1089 display = getenv("DISPLAY");
1090 if (options.forward_x11 && display != NULL) {
1092 /* Get reasonable local authentication information. */
1093 client_x11_get_proto(display, options.xauth_location,
1094 options.forward_x11_trusted, &proto, &data);
1095 /* Request forwarding with authentication spoofing. */
1096 debug("Requesting X11 forwarding with authentication spoofing.");
1097 x11_request_forwarding_with_spoofing(id, display, proto, data);
1099 /* XXX wait for reply */
1102 check_agent_present();
1103 if (options.forward_agent) {
1104 debug("Requesting authentication agent forwarding.");
1105 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1109 if (options.tun_open != SSH_TUNMODE_NO) {
1113 debug("Requesting tun.");
1114 if ((fd = tun_open(options.tun_local,
1115 options.tun_open)) >= 0) {
1116 if(options.hpn_disabled)
1117 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1118 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1121 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1122 options.hpn_buffer_size, CHAN_TCP_PACKET_DEFAULT,
1125 #if defined(SSH_TUN_FILTER)
1126 if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1127 channel_register_filter(c->self, sys_tun_infilter,
1130 packet_start(SSH2_MSG_CHANNEL_OPEN);
1131 packet_put_cstring("tun@openssh.com");
1132 packet_put_int(c->self);
1133 packet_put_int(c->local_window_max);
1134 packet_put_int(c->local_maxpacket);
1135 packet_put_int(options.tun_open);
1136 packet_put_int(options.tun_remote);
1141 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1142 NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply);
1144 packet_set_interactive(interactive);
1147 /* open new channel for a session */
1149 ssh_session2_open(void)
1152 int window, packetmax, in, out, err;
1154 if (stdin_null_flag) {
1155 in = open(_PATH_DEVNULL, O_RDONLY);
1157 in = dup(STDIN_FILENO);
1159 out = dup(STDOUT_FILENO);
1160 err = dup(STDERR_FILENO);
1162 if (in < 0 || out < 0 || err < 0)
1163 fatal("dup() in/out/err failed");
1165 /* enable nonblocking unless tty */
1173 if(options.hpn_disabled)
1174 window = CHAN_SES_WINDOW_DEFAULT;
1176 window = options.hpn_buffer_size;
1177 packetmax = CHAN_SES_PACKET_DEFAULT;
1179 window = 4*CHAN_SES_PACKET_DEFAULT;
1184 "session", SSH_CHANNEL_OPENING, in, out, err,
1185 window, packetmax, CHAN_EXTENDED_WRITE,
1186 "client-session", /*nonblock*/0);
1187 if ((options.tcp_rcv_buf_poll > 0) && (!options.hpn_disabled)) {
1188 c->dynamic_window = 1;
1189 debug ("Enabled Dynamic Window Scaling\n");
1191 debug3("ssh_session2_open: channel_new: %d", c->self);
1193 channel_send_open(c->self);
1195 channel_register_confirm(c->self, ssh_session2_setup, NULL);
1205 /* XXX should be pre-session */
1206 ssh_init_forwarding();
1207 ssh_control_listener();
1209 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1210 id = ssh_session2_open();
1212 /* Execute a local command */
1213 if (options.local_command != NULL &&
1214 options.permit_local_command)
1215 ssh_local_cmd(options.local_command);
1217 /* If requested, let ssh continue in the background. */
1218 if (fork_after_authentication_flag)
1219 if (daemon(1, 1) < 0)
1220 fatal("daemon() failed: %.200s", strerror(errno));
1222 return client_loop(tty_flag, tty_flag ?
1223 options.escape_char : SSH_ESCAPECHAR_NONE, id);
1227 load_public_identity_files(void)
1235 if (options.smartcard_device != NULL &&
1236 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1237 (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL ) {
1239 for (i = 0; keys[i] != NULL; i++) {
1241 memmove(&options.identity_files[1], &options.identity_files[0],
1242 sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1));
1243 memmove(&options.identity_keys[1], &options.identity_keys[0],
1244 sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1));
1245 options.num_identity_files++;
1246 options.identity_keys[0] = keys[i];
1247 options.identity_files[0] = sc_get_key_label(keys[i]);
1249 if (options.num_identity_files > SSH_MAX_IDENTITY_FILES)
1250 options.num_identity_files = SSH_MAX_IDENTITY_FILES;
1254 #endif /* SMARTCARD */
1255 for (; i < options.num_identity_files; i++) {
1256 filename = tilde_expand_filename(options.identity_files[i],
1258 public = key_load_public(filename, NULL);
1259 debug("identity file %s type %d", filename,
1260 public ? public->type : -1);
1261 xfree(options.identity_files[i]);
1262 options.identity_files[i] = filename;
1263 options.identity_keys[i] = public;
1268 control_client_sighandler(int signo)
1270 control_client_terminate = signo;
1274 control_client_sigrelay(int signo)
1276 if (control_server_pid > 1)
1277 kill(control_server_pid, signo);
1281 env_permitted(char *env)
1284 char name[1024], *cp;
1286 strlcpy(name, env, sizeof(name));
1287 if ((cp = strchr(name, '=')) == NULL)
1292 for (i = 0; i < options.num_send_env; i++)
1293 if (match_pattern(name, options.send_env[i]))
1300 control_client(const char *path)
1302 struct sockaddr_un addr;
1303 int i, r, fd, sock, exitval, num_env, addr_len;
1306 extern char **environ;
1309 if (mux_command == 0)
1310 mux_command = SSHMUX_COMMAND_OPEN;
1312 switch (options.control_master) {
1313 case SSHCTL_MASTER_AUTO:
1314 case SSHCTL_MASTER_AUTO_ASK:
1315 debug("auto-mux: Trying existing master");
1317 case SSHCTL_MASTER_NO:
1323 memset(&addr, '\0', sizeof(addr));
1324 addr.sun_family = AF_UNIX;
1325 addr_len = offsetof(struct sockaddr_un, sun_path) +
1328 if (strlcpy(addr.sun_path, path,
1329 sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1330 fatal("ControlPath too long");
1332 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1333 fatal("%s socket(): %s", __func__, strerror(errno));
1335 if (connect(sock, (struct sockaddr*)&addr, addr_len) == -1) {
1336 if (mux_command != SSHMUX_COMMAND_OPEN) {
1337 fatal("Control socket connect(%.100s): %s", path,
1340 if (errno == ENOENT)
1341 debug("Control socket \"%.100s\" does not exist", path);
1343 error("Control socket connect(%.100s): %s", path,
1350 if (stdin_null_flag) {
1351 if ((fd = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1352 fatal("open(/dev/null): %s", strerror(errno));
1353 if (dup2(fd, STDIN_FILENO) == -1)
1354 fatal("dup2: %s", strerror(errno));
1355 if (fd > STDERR_FILENO)
1359 term = getenv("TERM");
1363 flags |= SSHMUX_FLAG_TTY;
1365 flags |= SSHMUX_FLAG_SUBSYS;
1366 if (options.forward_x11)
1367 flags |= SSHMUX_FLAG_X11_FWD;
1368 if (options.forward_agent)
1369 flags |= SSHMUX_FLAG_AGENT_FWD;
1370 if (options.num_local_forwards > 0)
1371 flags |= SSHMUX_FLAG_PORTFORWARD;
1374 /* Send our command to server */
1375 buffer_put_int(&m, mux_command);
1376 buffer_put_int(&m, flags);
1377 if (options.num_local_forwards > 0)
1379 if (options.local_forwards[0].listen_host == NULL)
1380 buffer_put_string(&m,"LOCALHOST",11);
1382 buffer_put_string(&m,options.local_forwards[0].listen_host,512);
1383 buffer_put_int(&m,options.local_forwards[0].listen_port);
1384 buffer_put_string(&m,options.local_forwards[0].connect_host,512);
1385 buffer_put_int(&m,options.local_forwards[0].connect_port);
1387 if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
1388 fatal("%s: msg_send", __func__);
1391 /* Get authorisation status and PID of controlee */
1392 if (ssh_msg_recv(sock, &m) == -1)
1393 fatal("%s: msg_recv", __func__);
1394 if (buffer_get_char(&m) != SSHMUX_VER)
1395 fatal("%s: wrong version", __func__);
1396 if (buffer_get_int(&m) != 1)
1397 fatal("Connection to master denied");
1398 control_server_pid = buffer_get_int(&m);
1402 switch (mux_command) {
1403 case SSHMUX_COMMAND_ALIVE_CHECK:
1404 fprintf(stderr, "Master running (pid=%d)\r\n",
1405 control_server_pid);
1407 case SSHMUX_COMMAND_TERMINATE:
1408 fprintf(stderr, "Exit request sent.\r\n");
1410 case SSHMUX_COMMAND_OPEN:
1411 /* continue below */
1414 fatal("silly mux_command %d", mux_command);
1417 /* SSHMUX_COMMAND_OPEN */
1418 buffer_put_cstring(&m, term ? term : "");
1419 buffer_append(&command, "\0", 1);
1420 buffer_put_cstring(&m, buffer_ptr(&command));
1422 if (options.num_send_env == 0 || environ == NULL) {
1423 buffer_put_int(&m, 0);
1425 /* Pass environment */
1427 for (i = 0; environ[i] != NULL; i++)
1428 if (env_permitted(environ[i]))
1429 num_env++; /* Count */
1431 buffer_put_int(&m, num_env);
1433 for (i = 0; environ[i] != NULL && num_env >= 0; i++)
1434 if (env_permitted(environ[i])) {
1436 buffer_put_cstring(&m, environ[i]);
1440 if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
1441 fatal("%s: msg_send", __func__);
1443 mm_send_fd(sock, STDIN_FILENO);
1444 mm_send_fd(sock, STDOUT_FILENO);
1445 mm_send_fd(sock, STDERR_FILENO);
1447 /* Wait for reply, so master has a chance to gather ttymodes */
1449 if (ssh_msg_recv(sock, &m) == -1)
1450 fatal("%s: msg_recv", __func__);
1451 if (buffer_get_char(&m) != SSHMUX_VER)
1452 fatal("%s: wrong version", __func__);
1455 signal(SIGHUP, control_client_sighandler);
1456 signal(SIGINT, control_client_sighandler);
1457 signal(SIGTERM, control_client_sighandler);
1458 signal(SIGWINCH, control_client_sigrelay);
1463 /* Stick around until the controlee closes the client_fd */
1465 for (;!control_client_terminate;) {
1466 r = read(sock, &exitval, sizeof(exitval));
1468 debug2("Received EOF from master");
1472 debug2("Received exit status from master %d", exitval);
1473 if (r == -1 && errno != EINTR)
1474 fatal("%s: read %s", __func__, strerror(errno));
1477 if (control_client_terminate)
1478 debug2("Exiting on signal %d", control_client_terminate);
1484 if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1485 fprintf(stderr, "Connection to master closed.\r\n");