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 [-1246AaCfgkMNnqrsTtVvXxY] [-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"
166 " [-r Receive Buffer Size in K]\n"
171 static int ssh_session(void);
172 static int ssh_session2(void);
173 static void load_public_identity_files(void);
174 static void control_client(const char *path);
177 * Main program for the ssh client.
180 main(int ac, char **av)
182 int i, opt, exit_status;
183 char *p, *cp, *line, buf[256];
187 extern int optind, optreset;
192 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
195 __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. */
245 /* need to set options.tcp_rcv_buf to 0 */
246 options.tcp_rcv_buf = 0;
249 while ((opt = getopt(ac, av,
250 "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNO:PR:S:TVw:XYz")) != -1) {
253 options.protocol = SSH_PROTO_1;
256 options.protocol = SSH_PROTO_2;
259 options.address_family = AF_INET;
262 options.address_family = AF_INET6;
268 fork_after_authentication_flag = 1;
272 options.forward_x11 = 0;
275 options.forward_x11 = 1;
278 options.forward_x11 = 1;
279 options.forward_x11_trusted = 1;
282 options.gateway_ports = 1;
285 if (strcmp(optarg, "check") == 0)
286 mux_command = SSHMUX_COMMAND_ALIVE_CHECK;
287 else if (strcmp(optarg, "exit") == 0)
288 mux_command = SSHMUX_COMMAND_TERMINATE;
290 fatal("Invalid multiplex command.");
292 case 'P': /* deprecated */
293 options.use_privileged_port = 0;
296 options.forward_agent = 0;
299 options.forward_agent = 1;
302 options.gss_deleg_creds = 0;
305 if (stat(optarg, &st) < 0) {
306 fprintf(stderr, "Warning: Identity file %s "
307 "not accessible: %s.\n", optarg,
311 if (options.num_identity_files >=
312 SSH_MAX_IDENTITY_FILES)
313 fatal("Too many identity files specified "
314 "(max %d)", SSH_MAX_IDENTITY_FILES);
315 options.identity_files[options.num_identity_files++] =
320 options.smartcard_device = xstrdup(optarg);
322 fprintf(stderr, "no support for smartcards.\n");
331 if (debug_flag == 0) {
333 options.log_level = SYSLOG_LEVEL_DEBUG1;
335 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
341 fprintf(stderr, "%s, %s\n",
342 SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
347 if (options.tun_open == -1)
348 options.tun_open = SSH_TUNMODE_DEFAULT;
349 options.tun_local = a2tun(optarg, &options.tun_remote);
350 if (options.tun_local == SSH_TUNID_ERR) {
351 fprintf(stderr, "Bad tun device '%s'\n", optarg);
356 options.log_level = SYSLOG_LEVEL_QUIET;
359 if (optarg[0] == '^' && optarg[2] == 0 &&
360 (u_char) optarg[1] >= 64 &&
361 (u_char) optarg[1] < 128)
362 options.escape_char = (u_char) optarg[1] & 31;
363 else if (strlen(optarg) == 1)
364 options.escape_char = (u_char) optarg[0];
365 else if (strcmp(optarg, "none") == 0)
366 options.escape_char = SSH_ESCAPECHAR_NONE;
368 fprintf(stderr, "Bad escape character '%s'.\n",
374 if (ciphers_valid(optarg)) {
376 options.ciphers = xstrdup(optarg);
377 options.cipher = SSH_CIPHER_INVALID;
380 options.cipher = cipher_number(optarg);
381 if (options.cipher == -1) {
383 "Unknown cipher type '%s'\n",
387 if (options.cipher == SSH_CIPHER_3DES)
388 options.ciphers = "3des-cbc";
389 else if (options.cipher == SSH_CIPHER_BLOWFISH)
390 options.ciphers = "blowfish-cbc";
392 options.ciphers = (char *)-1;
396 if (mac_valid(optarg))
397 options.macs = xstrdup(optarg);
399 fprintf(stderr, "Unknown mac type '%s'\n",
405 if (options.control_master == SSHCTL_MASTER_YES)
406 options.control_master = SSHCTL_MASTER_ASK;
408 options.control_master = SSHCTL_MASTER_YES;
411 options.port = a2port(optarg);
412 if (options.port == 0) {
413 fprintf(stderr, "Bad port '%s'\n", optarg);
418 options.user = optarg;
422 if (parse_forward(&fwd, optarg))
423 add_local_forward(&options, &fwd);
426 "Bad local forwarding specification '%s'\n",
433 if (parse_forward(&fwd, optarg)) {
434 add_remote_forward(&options, &fwd);
437 "Bad remote forwarding specification "
444 cp = p = xstrdup(optarg);
445 memset(&fwd, '\0', sizeof(fwd));
446 fwd.connect_host = "socks";
447 if ((fwd.listen_host = hpdelim(&cp)) == NULL) {
448 fprintf(stderr, "Bad dynamic forwarding "
449 "specification '%.100s'\n", optarg);
453 fwd.listen_port = a2port(cp);
454 fwd.listen_host = cleanhostname(fwd.listen_host);
456 fwd.listen_port = a2port(fwd.listen_host);
457 fwd.listen_host = NULL;
460 if (fwd.listen_port == 0) {
461 fprintf(stderr, "Bad dynamic port '%s'\n",
465 add_local_forward(&options, &fwd);
470 options.compression = 1;
475 options.none_switch = 0;
479 options.none_switch = 0;
483 line = xstrdup(optarg);
484 if (process_config_line(&options, host ? host : "",
485 line, "command-line", 0, &dummy) != 0)
493 if (options.control_path != NULL)
494 free(options.control_path);
495 options.control_path = xstrdup(optarg);
498 options.bind_address = optarg;
503 options.tcp_rcv_buf = atoi(optarg) * 1024;
506 /* make sure we can't turn on the none_switch */
507 /* if they try to force a no tty flag on a tty session */
509 options.none_switch = 1;
521 if (ac > 0 && !host && **av != '-') {
522 if (strrchr(*av, '@')) {
524 cp = strrchr(p, '@');
525 if (cp == NULL || cp == p)
533 optind = optreset = 1;
539 /* Check that we got a host name. */
543 SSLeay_add_all_algorithms();
544 ERR_load_crypto_strings();
546 /* Initialize the command to execute on remote host. */
547 buffer_init(&command);
550 * Save the command to execute on the remote host in a buffer. There
551 * is no limit on the length of the command, except by the maximum
552 * packet size. Also sets the tty flag if there is no command.
555 /* No command specified - execute shell on a tty. */
557 if (subsystem_flag) {
559 "You must specify a subsystem to invoke.\n");
563 /* A command has been specified. Store it into the buffer. */
564 for (i = 0; i < ac; i++) {
566 buffer_append(&command, " ", 1);
567 buffer_append(&command, av[i], strlen(av[i]));
571 /* Cannot fork to background if no command. */
572 if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag)
573 fatal("Cannot fork into background without a command to execute.");
575 /* Allocate a tty by default if no command specified. */
576 if (buffer_len(&command) == 0)
582 /* Do not allocate a tty if stdin is not a tty. */
583 if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
585 logit("Pseudo-terminal will not be allocated because stdin is not a terminal.");
590 * Initialize "log" output. Since we are the client all output
591 * actually goes to stderr.
593 log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
594 SYSLOG_FACILITY_USER, 1);
597 * Read per-user configuration file. Ignore the system wide config
598 * file if the user specifies a config file on the command line.
600 if (config != NULL) {
601 if (!read_config_file(config, host, &options, 0))
602 fatal("Can't open user config file %.100s: "
603 "%.100s", config, strerror(errno));
606 * Since the config file parsing code aborts if it sees
607 * options it doesn't recognize, allow users to put
608 * options specific to compile-time add-ons in alternate
609 * config files so their primary config file will
610 * interoperate SSH versions that don't support those
614 snprintf(buf, sizeof buf, "%.100s/%.100s.gssapi", pw->pw_dir,
615 _PATH_SSH_USER_CONFFILE);
616 (void)read_config_file(buf, host, &options, 1);
618 snprintf(buf, sizeof buf, "%.100s/%.100s.gsi", pw->pw_dir,
619 _PATH_SSH_USER_CONFFILE);
620 (void)read_config_file(buf, host, &options, 1);
623 snprintf(buf, sizeof buf, "%.100s/%.100s.krb", pw->pw_dir,
624 _PATH_SSH_USER_CONFFILE);
625 (void)read_config_file(buf, host, &options, 1);
628 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
629 _PATH_SSH_USER_CONFFILE);
630 (void)read_config_file(buf, host, &options, 1);
632 /* Read systemwide configuration file after use config. */
633 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
637 /* Fill configuration defaults. */
638 fill_default_options(&options);
640 channel_set_af(options.address_family);
643 log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1);
647 if (options.user == NULL) {
648 options.user = xstrdup(pw->pw_name);
649 options.implicit = 1;
651 else options.implicit = 0;
653 if (options.hostname != NULL)
654 host = options.hostname;
656 /* force lowercase for hostkey matching */
657 if (options.host_key_alias != NULL) {
658 for (p = options.host_key_alias; *p; p++)
663 /* Get default port if port has not been set. */
664 if (options.port == 0) {
665 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
666 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
669 if (options.proxy_command != NULL &&
670 strcmp(options.proxy_command, "none") == 0)
671 options.proxy_command = NULL;
672 if (options.control_path != NULL &&
673 strcmp(options.control_path, "none") == 0)
674 options.control_path = NULL;
676 if (options.control_path != NULL) {
677 snprintf(buf, sizeof(buf), "%d", options.port);
678 cp = tilde_expand_filename(options.control_path,
680 options.control_path = percent_expand(cp, "p", buf, "h", host,
681 "r", options.user, (char *)NULL);
684 if (mux_command != 0 && options.control_path == NULL)
685 fatal("No ControlPath specified for \"-O\" command");
686 if (options.control_path != NULL)
687 control_client(options.control_path);
689 /* Open a connection to the remote host. */
690 if (ssh_connect(host, &hostaddr, options.port,
691 options.address_family, options.connection_attempts,
693 options.use_privileged_port,
695 original_effective_uid == 0 && options.use_privileged_port,
697 options.proxy_command) != 0)
701 * If we successfully made the connection, load the host private key
702 * in case we will need it later for combined rsa-rhosts
703 * authentication. This must be done before releasing extra
704 * privileges, because the file is only readable by root.
705 * If we cannot access the private keys, load the public keys
706 * instead and try to execute the ssh-keysign helper instead.
708 sensitive_data.nkeys = 0;
709 sensitive_data.keys = NULL;
710 sensitive_data.external_keysign = 0;
711 if (options.rhosts_rsa_authentication ||
712 options.hostbased_authentication) {
713 sensitive_data.nkeys = 3;
714 sensitive_data.keys = xmalloc(sensitive_data.nkeys *
718 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
719 _PATH_HOST_KEY_FILE, "", NULL);
720 sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
721 _PATH_HOST_DSA_KEY_FILE, "", NULL);
722 sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
723 _PATH_HOST_RSA_KEY_FILE, "", NULL);
726 if (options.hostbased_authentication == 1 &&
727 sensitive_data.keys[0] == NULL &&
728 sensitive_data.keys[1] == NULL &&
729 sensitive_data.keys[2] == NULL) {
730 sensitive_data.keys[1] = key_load_public(
731 _PATH_HOST_DSA_KEY_FILE, NULL);
732 sensitive_data.keys[2] = key_load_public(
733 _PATH_HOST_RSA_KEY_FILE, NULL);
734 sensitive_data.external_keysign = 1;
738 * Get rid of any extra privileges that we may have. We will no
739 * longer need them. Also, extra privileges could make it very hard
740 * to read identity files and other non-world-readable files from the
741 * user's home directory if it happens to be on a NFS volume where
742 * root is mapped to nobody.
744 if (original_effective_uid == 0) {
746 permanently_set_uid(pw);
750 * Now that we are back to our own permissions, create ~/.ssh
751 * directory if it doesn't already exist.
753 snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
754 if (stat(buf, &st) < 0)
755 if (mkdir(buf, 0700) < 0)
756 error("Could not create directory '%.200s'.", buf);
758 /* load options.identity_files */
759 load_public_identity_files();
761 /* Expand ~ in known host file names. */
763 options.system_hostfile =
764 tilde_expand_filename(options.system_hostfile, original_real_uid);
765 options.user_hostfile =
766 tilde_expand_filename(options.user_hostfile, original_real_uid);
767 options.system_hostfile2 =
768 tilde_expand_filename(options.system_hostfile2, original_real_uid);
769 options.user_hostfile2 =
770 tilde_expand_filename(options.user_hostfile2, original_real_uid);
772 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
774 /* Log into the remote system. This never returns if the login fails. */
775 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw);
777 /* We no longer need the private host keys. Clear them now. */
778 if (sensitive_data.nkeys != 0) {
779 for (i = 0; i < sensitive_data.nkeys; i++) {
780 if (sensitive_data.keys[i] != NULL) {
781 /* Destroys contents safely */
782 debug3("clear hostkey %d", i);
783 key_free(sensitive_data.keys[i]);
784 sensitive_data.keys[i] = NULL;
787 xfree(sensitive_data.keys);
789 for (i = 0; i < options.num_identity_files; i++) {
790 if (options.identity_files[i]) {
791 xfree(options.identity_files[i]);
792 options.identity_files[i] = NULL;
794 if (options.identity_keys[i]) {
795 key_free(options.identity_keys[i]);
796 options.identity_keys[i] = NULL;
800 exit_status = compat20 ? ssh_session2() : ssh_session();
803 if (options.control_path != NULL && control_fd != -1)
804 unlink(options.control_path);
807 * Send SIGHUP to proxy command if used. We don't wait() in
808 * case it hangs and instead rely on init to reap the child
810 if (proxy_command_pid > 1)
811 kill(proxy_command_pid, SIGHUP);
817 ssh_init_forwarding(void)
822 /* Initiate local TCP/IP port forwardings. */
823 for (i = 0; i < options.num_local_forwards; i++) {
824 debug("Local connections to %.200s:%d forwarded to remote "
826 (options.local_forwards[i].listen_host == NULL) ?
827 (options.gateway_ports ? "*" : "LOCALHOST") :
828 options.local_forwards[i].listen_host,
829 options.local_forwards[i].listen_port,
830 options.local_forwards[i].connect_host,
831 options.local_forwards[i].connect_port);
832 success += channel_setup_local_fwd_listener(
833 options.local_forwards[i].listen_host,
834 options.local_forwards[i].listen_port,
835 options.local_forwards[i].connect_host,
836 options.local_forwards[i].connect_port,
837 options.gateway_ports);
839 if (i > 0 && success == 0)
840 error("Could not request local forwarding.");
842 /* Initiate remote TCP/IP port forwardings. */
843 for (i = 0; i < options.num_remote_forwards; i++) {
844 debug("Remote connections from %.200s:%d forwarded to "
845 "local address %.200s:%d",
846 (options.remote_forwards[i].listen_host == NULL) ?
847 "LOCALHOST" : options.remote_forwards[i].listen_host,
848 options.remote_forwards[i].listen_port,
849 options.remote_forwards[i].connect_host,
850 options.remote_forwards[i].connect_port);
851 channel_request_remote_forwarding(
852 options.remote_forwards[i].listen_host,
853 options.remote_forwards[i].listen_port,
854 options.remote_forwards[i].connect_host,
855 options.remote_forwards[i].connect_port);
860 check_agent_present(void)
862 if (options.forward_agent) {
863 /* Clear agent forwarding if we don't have an agent. */
864 if (!ssh_agent_present())
865 options.forward_agent = 0;
879 /* Enable compression if requested. */
880 if (options.compression) {
881 debug("Requesting compression at level %d.", options.compression_level);
883 if (options.compression_level < 1 || options.compression_level > 9)
884 fatal("Compression level must be from 1 (fast) to 9 (slow, best).");
886 /* Send the request. */
887 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
888 packet_put_int(options.compression_level);
891 type = packet_read();
892 if (type == SSH_SMSG_SUCCESS)
893 packet_start_compression(options.compression_level);
894 else if (type == SSH_SMSG_FAILURE)
895 logit("Warning: Remote host refused compression.");
897 packet_disconnect("Protocol error waiting for compression response.");
899 /* Allocate a pseudo tty if appropriate. */
901 debug("Requesting pty.");
903 /* Start the packet. */
904 packet_start(SSH_CMSG_REQUEST_PTY);
906 /* Store TERM in the packet. There is no limit on the
907 length of the string. */
911 packet_put_cstring(cp);
913 /* Store window size in the packet. */
914 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
915 memset(&ws, 0, sizeof(ws));
916 packet_put_int(ws.ws_row);
917 packet_put_int(ws.ws_col);
918 packet_put_int(ws.ws_xpixel);
919 packet_put_int(ws.ws_ypixel);
921 /* Store tty modes in the packet. */
922 tty_make_modes(fileno(stdin), NULL);
924 /* Send the packet, and wait for it to leave. */
928 /* Read response from the server. */
929 type = packet_read();
930 if (type == SSH_SMSG_SUCCESS) {
933 } else if (type == SSH_SMSG_FAILURE)
934 logit("Warning: Remote host failed or refused to allocate a pseudo tty.");
936 packet_disconnect("Protocol error waiting for pty request response.");
938 /* Request X11 forwarding if enabled and DISPLAY is set. */
939 display = getenv("DISPLAY");
940 if (options.forward_x11 && display != NULL) {
942 /* Get reasonable local authentication information. */
943 client_x11_get_proto(display, options.xauth_location,
944 options.forward_x11_trusted, &proto, &data);
945 /* Request forwarding with authentication spoofing. */
946 debug("Requesting X11 forwarding with authentication spoofing.");
947 x11_request_forwarding_with_spoofing(0, display, proto, data);
949 /* Read response from the server. */
950 type = packet_read();
951 if (type == SSH_SMSG_SUCCESS) {
953 } else if (type == SSH_SMSG_FAILURE) {
954 logit("Warning: Remote host denied X11 forwarding.");
956 packet_disconnect("Protocol error waiting for X11 forwarding");
959 /* Tell the packet module whether this is an interactive session. */
960 packet_set_interactive(interactive);
962 /* Request authentication agent forwarding if appropriate. */
963 check_agent_present();
965 if (options.forward_agent) {
966 debug("Requesting authentication agent forwarding.");
967 auth_request_forwarding();
969 /* Read response from the server. */
970 type = packet_read();
972 if (type != SSH_SMSG_SUCCESS)
973 logit("Warning: Remote host denied authentication agent forwarding.");
976 /* Initiate port forwardings. */
977 ssh_init_forwarding();
979 /* If requested, let ssh continue in the background. */
980 if (fork_after_authentication_flag)
981 if (daemon(1, 1) < 0)
982 fatal("daemon() failed: %.200s", strerror(errno));
985 * If a command was specified on the command line, execute the
986 * command now. Otherwise request the server to start a shell.
988 if (buffer_len(&command) > 0) {
989 int len = buffer_len(&command);
992 debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command));
993 packet_start(SSH_CMSG_EXEC_CMD);
994 packet_put_string(buffer_ptr(&command), buffer_len(&command));
998 debug("Requesting shell.");
999 packet_start(SSH_CMSG_EXEC_SHELL);
1001 packet_write_wait();
1004 /* Enter the interactive session. */
1005 return client_loop(have_tty, tty_flag ?
1006 options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1010 ssh_subsystem_reply(int type, u_int32_t seq, void *ctxt)
1014 id = packet_get_int();
1015 len = buffer_len(&command);
1019 if (type == SSH2_MSG_CHANNEL_FAILURE)
1020 fatal("Request for subsystem '%.*s' failed on channel %d",
1021 len, (u_char *)buffer_ptr(&command), id);
1025 client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt)
1029 i = client_global_request_id++;
1030 if (i >= options.num_remote_forwards)
1032 debug("remote forward %s for: listen %d, connect %s:%d",
1033 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1034 options.remote_forwards[i].listen_port,
1035 options.remote_forwards[i].connect_host,
1036 options.remote_forwards[i].connect_port);
1037 if (type == SSH2_MSG_REQUEST_FAILURE)
1038 logit("Warning: remote port forwarding failed for listen "
1039 "port %d", options.remote_forwards[i].listen_port);
1043 ssh_control_listener(void)
1045 struct sockaddr_un addr;
1049 if (options.control_path == NULL ||
1050 options.control_master == SSHCTL_MASTER_NO)
1053 debug("setting up multiplex master socket");
1055 memset(&addr, '\0', sizeof(addr));
1056 addr.sun_family = AF_UNIX;
1057 addr_len = offsetof(struct sockaddr_un, sun_path) +
1058 strlen(options.control_path) + 1;
1060 if (strlcpy(addr.sun_path, options.control_path,
1061 sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1062 fatal("ControlPath too long");
1064 if ((control_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1065 fatal("%s socket(): %s", __func__, strerror(errno));
1067 old_umask = umask(0177);
1068 if (bind(control_fd, (struct sockaddr*)&addr, addr_len) == -1) {
1070 if (errno == EINVAL || errno == EADDRINUSE)
1071 fatal("ControlSocket %s already exists",
1072 options.control_path);
1074 fatal("%s bind(): %s", __func__, strerror(errno));
1078 if (listen(control_fd, 64) == -1)
1079 fatal("%s listen(): %s", __func__, strerror(errno));
1081 set_nonblock(control_fd);
1084 /* request pty/x11/agent/tcpfwd/shell for channel */
1086 ssh_session2_setup(int id, void *arg)
1088 extern char **environ;
1089 const char *display;
1090 int interactive = tty_flag;
1092 display = getenv("DISPLAY");
1093 if (options.forward_x11 && display != NULL) {
1095 /* Get reasonable local authentication information. */
1096 client_x11_get_proto(display, options.xauth_location,
1097 options.forward_x11_trusted, &proto, &data);
1098 /* Request forwarding with authentication spoofing. */
1099 debug("Requesting X11 forwarding with authentication spoofing.");
1100 x11_request_forwarding_with_spoofing(id, display, proto, data);
1102 /* XXX wait for reply */
1105 check_agent_present();
1106 if (options.forward_agent) {
1107 debug("Requesting authentication agent forwarding.");
1108 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1112 if (options.tun_open != SSH_TUNMODE_NO) {
1116 debug("Requesting tun.");
1117 if ((fd = tun_open(options.tun_local,
1118 options.tun_open)) >= 0) {
1119 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
1120 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
1123 #if defined(SSH_TUN_FILTER)
1124 if (options.tun_open == SSH_TUNMODE_POINTOPOINT)
1125 channel_register_filter(c->self, sys_tun_infilter,
1128 packet_start(SSH2_MSG_CHANNEL_OPEN);
1129 packet_put_cstring("tun@openssh.com");
1130 packet_put_int(c->self);
1131 packet_put_int(c->local_window_max);
1132 packet_put_int(c->local_maxpacket);
1133 packet_put_int(options.tun_open);
1134 packet_put_int(options.tun_remote);
1139 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1140 NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply);
1142 packet_set_interactive(interactive);
1145 /* open new channel for a session */
1147 ssh_session2_open(void)
1150 int window, packetmax, in, out, err;
1152 if (stdin_null_flag) {
1153 in = open(_PATH_DEVNULL, O_RDONLY);
1155 in = dup(STDIN_FILENO);
1157 out = dup(STDOUT_FILENO);
1158 err = dup(STDERR_FILENO);
1160 if (in < 0 || out < 0 || err < 0)
1161 fatal("dup() in/out/err failed");
1163 /* enable nonblocking unless tty */
1171 window = CHAN_SES_WINDOW_DEFAULT;
1172 packetmax = CHAN_SES_PACKET_DEFAULT;
1174 window = 4*CHAN_SES_PACKET_DEFAULT;
1179 "session", SSH_CHANNEL_OPENING, in, out, err,
1180 window, packetmax, CHAN_EXTENDED_WRITE,
1181 "client-session", /*nonblock*/0);
1182 if (!tty_flag && (!(datafellows & SSH_BUG_LARGEWINDOW))) {
1183 c->dynamic_window = 1;
1185 debug3("ssh_session2_open: channel_new: %d", c->self);
1187 channel_send_open(c->self);
1189 channel_register_confirm(c->self, ssh_session2_setup, NULL);
1199 /* XXX should be pre-session */
1200 ssh_init_forwarding();
1201 ssh_control_listener();
1203 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1204 id = ssh_session2_open();
1206 /* Execute a local command */
1207 if (options.local_command != NULL &&
1208 options.permit_local_command)
1209 ssh_local_cmd(options.local_command);
1211 /* If requested, let ssh continue in the background. */
1212 if (fork_after_authentication_flag)
1213 if (daemon(1, 1) < 0)
1214 fatal("daemon() failed: %.200s", strerror(errno));
1216 return client_loop(tty_flag, tty_flag ?
1217 options.escape_char : SSH_ESCAPECHAR_NONE, id);
1221 load_public_identity_files(void)
1229 if (options.smartcard_device != NULL &&
1230 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1231 (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL ) {
1233 for (i = 0; keys[i] != NULL; i++) {
1235 memmove(&options.identity_files[1], &options.identity_files[0],
1236 sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1));
1237 memmove(&options.identity_keys[1], &options.identity_keys[0],
1238 sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1));
1239 options.num_identity_files++;
1240 options.identity_keys[0] = keys[i];
1241 options.identity_files[0] = sc_get_key_label(keys[i]);
1243 if (options.num_identity_files > SSH_MAX_IDENTITY_FILES)
1244 options.num_identity_files = SSH_MAX_IDENTITY_FILES;
1248 #endif /* SMARTCARD */
1249 for (; i < options.num_identity_files; i++) {
1250 filename = tilde_expand_filename(options.identity_files[i],
1252 public = key_load_public(filename, NULL);
1253 debug("identity file %s type %d", filename,
1254 public ? public->type : -1);
1255 xfree(options.identity_files[i]);
1256 options.identity_files[i] = filename;
1257 options.identity_keys[i] = public;
1262 control_client_sighandler(int signo)
1264 control_client_terminate = signo;
1268 control_client_sigrelay(int signo)
1270 if (control_server_pid > 1)
1271 kill(control_server_pid, signo);
1275 env_permitted(char *env)
1278 char name[1024], *cp;
1280 strlcpy(name, env, sizeof(name));
1281 if ((cp = strchr(name, '=')) == NULL)
1286 for (i = 0; i < options.num_send_env; i++)
1287 if (match_pattern(name, options.send_env[i]))
1294 control_client(const char *path)
1296 struct sockaddr_un addr;
1297 int i, r, fd, sock, exitval, num_env, addr_len;
1300 extern char **environ;
1303 if (mux_command == 0)
1304 mux_command = SSHMUX_COMMAND_OPEN;
1306 switch (options.control_master) {
1307 case SSHCTL_MASTER_AUTO:
1308 case SSHCTL_MASTER_AUTO_ASK:
1309 debug("auto-mux: Trying existing master");
1311 case SSHCTL_MASTER_NO:
1317 memset(&addr, '\0', sizeof(addr));
1318 addr.sun_family = AF_UNIX;
1319 addr_len = offsetof(struct sockaddr_un, sun_path) +
1322 if (strlcpy(addr.sun_path, path,
1323 sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1324 fatal("ControlPath too long");
1326 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1327 fatal("%s socket(): %s", __func__, strerror(errno));
1329 if (connect(sock, (struct sockaddr*)&addr, addr_len) == -1) {
1330 if (mux_command != SSHMUX_COMMAND_OPEN) {
1331 fatal("Control socket connect(%.100s): %s", path,
1334 if (errno == ENOENT)
1335 debug("Control socket \"%.100s\" does not exist", path);
1337 error("Control socket connect(%.100s): %s", path,
1344 if (stdin_null_flag) {
1345 if ((fd = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1346 fatal("open(/dev/null): %s", strerror(errno));
1347 if (dup2(fd, STDIN_FILENO) == -1)
1348 fatal("dup2: %s", strerror(errno));
1349 if (fd > STDERR_FILENO)
1353 term = getenv("TERM");
1357 flags |= SSHMUX_FLAG_TTY;
1359 flags |= SSHMUX_FLAG_SUBSYS;
1360 if (options.forward_x11)
1361 flags |= SSHMUX_FLAG_X11_FWD;
1362 if (options.forward_agent)
1363 flags |= SSHMUX_FLAG_AGENT_FWD;
1367 /* Send our command to server */
1368 buffer_put_int(&m, mux_command);
1369 buffer_put_int(&m, flags);
1370 if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
1371 fatal("%s: msg_send", __func__);
1374 /* Get authorisation status and PID of controlee */
1375 if (ssh_msg_recv(sock, &m) == -1)
1376 fatal("%s: msg_recv", __func__);
1377 if (buffer_get_char(&m) != SSHMUX_VER)
1378 fatal("%s: wrong version", __func__);
1379 if (buffer_get_int(&m) != 1)
1380 fatal("Connection to master denied");
1381 control_server_pid = buffer_get_int(&m);
1385 switch (mux_command) {
1386 case SSHMUX_COMMAND_ALIVE_CHECK:
1387 fprintf(stderr, "Master running (pid=%d)\r\n",
1388 control_server_pid);
1390 case SSHMUX_COMMAND_TERMINATE:
1391 fprintf(stderr, "Exit request sent.\r\n");
1393 case SSHMUX_COMMAND_OPEN:
1394 /* continue below */
1397 fatal("silly mux_command %d", mux_command);
1400 /* SSHMUX_COMMAND_OPEN */
1401 buffer_put_cstring(&m, term ? term : "");
1402 buffer_append(&command, "\0", 1);
1403 buffer_put_cstring(&m, buffer_ptr(&command));
1405 if (options.num_send_env == 0 || environ == NULL) {
1406 buffer_put_int(&m, 0);
1408 /* Pass environment */
1410 for (i = 0; environ[i] != NULL; i++)
1411 if (env_permitted(environ[i]))
1412 num_env++; /* Count */
1414 buffer_put_int(&m, num_env);
1416 for (i = 0; environ[i] != NULL && num_env >= 0; i++)
1417 if (env_permitted(environ[i])) {
1419 buffer_put_cstring(&m, environ[i]);
1423 if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
1424 fatal("%s: msg_send", __func__);
1426 mm_send_fd(sock, STDIN_FILENO);
1427 mm_send_fd(sock, STDOUT_FILENO);
1428 mm_send_fd(sock, STDERR_FILENO);
1430 /* Wait for reply, so master has a chance to gather ttymodes */
1432 if (ssh_msg_recv(sock, &m) == -1)
1433 fatal("%s: msg_recv", __func__);
1434 if (buffer_get_char(&m) != SSHMUX_VER)
1435 fatal("%s: wrong version", __func__);
1438 signal(SIGHUP, control_client_sighandler);
1439 signal(SIGINT, control_client_sighandler);
1440 signal(SIGTERM, control_client_sighandler);
1441 signal(SIGWINCH, control_client_sigrelay);
1446 /* Stick around until the controlee closes the client_fd */
1448 for (;!control_client_terminate;) {
1449 r = read(sock, &exitval, sizeof(exitval));
1451 debug2("Received EOF from master");
1455 debug2("Received exit status from master %d", exitval);
1456 if (r == -1 && errno != EINTR)
1457 fatal("%s: read %s", __func__, strerror(errno));
1460 if (control_client_terminate)
1461 debug2("Exiting on signal %d", control_client_terminate);
1467 if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1468 fprintf(stderr, "Connection to master closed.\r\n");