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 1.249 2005/07/30 01:26:16 djm 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 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 " [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 __progname = ssh_get_progname(av[0]);
195 * Save the original real uid. It will be needed later (uid-swapping
196 * may clobber the real uid).
198 original_real_uid = getuid();
199 original_effective_uid = geteuid();
202 * Use uid-swapping to give up root privileges for the duration of
203 * option processing. We will re-instantiate the rights when we are
204 * ready to create the privileged port, and will permanently drop
205 * them when the port has been created (actually, when the connection
206 * has been made, as we may need to create the port several times).
210 #ifdef HAVE_SETRLIMIT
211 /* If we are installed setuid root be careful to not drop core. */
212 if (original_real_uid != original_effective_uid) {
214 rlim.rlim_cur = rlim.rlim_max = 0;
215 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
216 fatal("setrlimit failed: %.100s", strerror(errno));
220 pw = getpwuid(original_real_uid);
222 logit("You don't exist, go away!");
225 /* Take a copy of the returned structure. */
229 * Set our umask to something reasonable, as some files are created
230 * with the default umask. This will make them world-readable but
231 * writable only by the owner, which is ok for all files for which we
232 * don't set the modes explicitly.
236 /* Initialize option structure to indicate that no values have been set. */
237 initialize_options(&options);
239 /* Parse command-line arguments. */
243 while ((opt = getopt(ac, av,
244 "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNO:PR:S:TVXY")) != -1) {
247 options.protocol = SSH_PROTO_1;
250 options.protocol = SSH_PROTO_2;
253 options.address_family = AF_INET;
256 options.address_family = AF_INET6;
262 fork_after_authentication_flag = 1;
266 options.forward_x11 = 0;
269 options.forward_x11 = 1;
272 options.forward_x11 = 1;
273 options.forward_x11_trusted = 1;
276 options.gateway_ports = 1;
279 if (strcmp(optarg, "check") == 0)
280 mux_command = SSHMUX_COMMAND_ALIVE_CHECK;
281 else if (strcmp(optarg, "exit") == 0)
282 mux_command = SSHMUX_COMMAND_TERMINATE;
284 fatal("Invalid multiplex command.");
286 case 'P': /* deprecated */
287 options.use_privileged_port = 0;
290 options.forward_agent = 0;
293 options.forward_agent = 1;
296 options.gss_deleg_creds = 0;
299 if (stat(optarg, &st) < 0) {
300 fprintf(stderr, "Warning: Identity file %s "
301 "not accessible: %s.\n", optarg,
305 if (options.num_identity_files >=
306 SSH_MAX_IDENTITY_FILES)
307 fatal("Too many identity files specified "
308 "(max %d)", SSH_MAX_IDENTITY_FILES);
309 options.identity_files[options.num_identity_files++] =
314 options.smartcard_device = xstrdup(optarg);
316 fprintf(stderr, "no support for smartcards.\n");
325 if (debug_flag == 0) {
327 options.log_level = SYSLOG_LEVEL_DEBUG1;
329 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
335 fprintf(stderr, "%s, %s\n",
336 SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
341 options.log_level = SYSLOG_LEVEL_QUIET;
344 if (optarg[0] == '^' && optarg[2] == 0 &&
345 (u_char) optarg[1] >= 64 &&
346 (u_char) optarg[1] < 128)
347 options.escape_char = (u_char) optarg[1] & 31;
348 else if (strlen(optarg) == 1)
349 options.escape_char = (u_char) optarg[0];
350 else if (strcmp(optarg, "none") == 0)
351 options.escape_char = SSH_ESCAPECHAR_NONE;
353 fprintf(stderr, "Bad escape character '%s'.\n",
359 if (ciphers_valid(optarg)) {
361 options.ciphers = xstrdup(optarg);
362 options.cipher = SSH_CIPHER_INVALID;
365 options.cipher = cipher_number(optarg);
366 if (options.cipher == -1) {
368 "Unknown cipher type '%s'\n",
372 if (options.cipher == SSH_CIPHER_3DES)
373 options.ciphers = "3des-cbc";
374 else if (options.cipher == SSH_CIPHER_BLOWFISH)
375 options.ciphers = "blowfish-cbc";
377 options.ciphers = (char *)-1;
381 if (mac_valid(optarg))
382 options.macs = xstrdup(optarg);
384 fprintf(stderr, "Unknown mac type '%s'\n",
390 if (options.control_master == SSHCTL_MASTER_YES)
391 options.control_master = SSHCTL_MASTER_ASK;
393 options.control_master = SSHCTL_MASTER_YES;
396 options.port = a2port(optarg);
397 if (options.port == 0) {
398 fprintf(stderr, "Bad port '%s'\n", optarg);
403 options.user = optarg;
407 if (parse_forward(&fwd, optarg))
408 add_local_forward(&options, &fwd);
411 "Bad local forwarding specification '%s'\n",
418 if (parse_forward(&fwd, optarg)) {
419 add_remote_forward(&options, &fwd);
422 "Bad remote forwarding specification "
429 cp = p = xstrdup(optarg);
430 memset(&fwd, '\0', sizeof(fwd));
431 fwd.connect_host = "socks";
432 if ((fwd.listen_host = hpdelim(&cp)) == NULL) {
433 fprintf(stderr, "Bad dynamic forwarding "
434 "specification '%.100s'\n", optarg);
438 fwd.listen_port = a2port(cp);
439 fwd.listen_host = cleanhostname(fwd.listen_host);
441 fwd.listen_port = a2port(fwd.listen_host);
442 fwd.listen_host = NULL;
445 if (fwd.listen_port == 0) {
446 fprintf(stderr, "Bad dynamic port '%s'\n",
450 add_local_forward(&options, &fwd);
455 options.compression = 1;
466 line = xstrdup(optarg);
467 if (process_config_line(&options, host ? host : "",
468 line, "command-line", 0, &dummy) != 0)
476 if (options.control_path != NULL)
477 free(options.control_path);
478 options.control_path = xstrdup(optarg);
481 options.bind_address = optarg;
494 if (ac > 0 && !host && **av != '-') {
495 if (strrchr(*av, '@')) {
497 cp = strrchr(p, '@');
498 if (cp == NULL || cp == p)
506 optind = optreset = 1;
512 /* Check that we got a host name. */
516 SSLeay_add_all_algorithms();
517 ERR_load_crypto_strings();
519 /* Initialize the command to execute on remote host. */
520 buffer_init(&command);
523 * Save the command to execute on the remote host in a buffer. There
524 * is no limit on the length of the command, except by the maximum
525 * packet size. Also sets the tty flag if there is no command.
528 /* No command specified - execute shell on a tty. */
530 if (subsystem_flag) {
532 "You must specify a subsystem to invoke.\n");
536 /* A command has been specified. Store it into the buffer. */
537 for (i = 0; i < ac; i++) {
539 buffer_append(&command, " ", 1);
540 buffer_append(&command, av[i], strlen(av[i]));
544 /* Cannot fork to background if no command. */
545 if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag)
546 fatal("Cannot fork into background without a command to execute.");
548 /* Allocate a tty by default if no command specified. */
549 if (buffer_len(&command) == 0)
555 /* Do not allocate a tty if stdin is not a tty. */
556 if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
558 logit("Pseudo-terminal will not be allocated because stdin is not a terminal.");
563 * Initialize "log" output. Since we are the client all output
564 * actually goes to stderr.
566 log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
567 SYSLOG_FACILITY_USER, 1);
570 * Read per-user configuration file. Ignore the system wide config
571 * file if the user specifies a config file on the command line.
573 if (config != NULL) {
574 if (!read_config_file(config, host, &options, 0))
575 fatal("Can't open user config file %.100s: "
576 "%.100s", config, strerror(errno));
578 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
579 _PATH_SSH_USER_CONFFILE);
580 (void)read_config_file(buf, host, &options, 1);
582 /* Read systemwide configuration file after use config. */
583 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
587 /* Fill configuration defaults. */
588 fill_default_options(&options);
590 channel_set_af(options.address_family);
593 log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1);
597 if (options.user == NULL)
598 options.user = xstrdup(pw->pw_name);
600 if (options.hostname != NULL)
601 host = options.hostname;
603 /* force lowercase for hostkey matching */
604 if (options.host_key_alias != NULL) {
605 for (p = options.host_key_alias; *p; p++)
610 /* Get default port if port has not been set. */
611 if (options.port == 0) {
612 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
613 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
616 if (options.proxy_command != NULL &&
617 strcmp(options.proxy_command, "none") == 0)
618 options.proxy_command = NULL;
619 if (options.control_path != NULL &&
620 strcmp(options.control_path, "none") == 0)
621 options.control_path = NULL;
623 if (options.control_path != NULL) {
624 snprintf(buf, sizeof(buf), "%d", options.port);
625 cp = tilde_expand_filename(options.control_path,
627 options.control_path = percent_expand(cp, "p", buf, "h", host,
628 "r", options.user, (char *)NULL);
631 if (mux_command != 0 && options.control_path == NULL)
632 fatal("No ControlPath specified for \"-O\" command");
633 if (options.control_path != NULL)
634 control_client(options.control_path);
636 /* Open a connection to the remote host. */
637 if (ssh_connect(host, &hostaddr, options.port,
638 options.address_family, options.connection_attempts,
640 options.use_privileged_port,
642 original_effective_uid == 0 && options.use_privileged_port,
644 options.proxy_command) != 0)
648 * If we successfully made the connection, load the host private key
649 * in case we will need it later for combined rsa-rhosts
650 * authentication. This must be done before releasing extra
651 * privileges, because the file is only readable by root.
652 * If we cannot access the private keys, load the public keys
653 * instead and try to execute the ssh-keysign helper instead.
655 sensitive_data.nkeys = 0;
656 sensitive_data.keys = NULL;
657 sensitive_data.external_keysign = 0;
658 if (options.rhosts_rsa_authentication ||
659 options.hostbased_authentication) {
660 sensitive_data.nkeys = 3;
661 sensitive_data.keys = xmalloc(sensitive_data.nkeys *
665 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
666 _PATH_HOST_KEY_FILE, "", NULL);
667 sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
668 _PATH_HOST_DSA_KEY_FILE, "", NULL);
669 sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
670 _PATH_HOST_RSA_KEY_FILE, "", NULL);
673 if (options.hostbased_authentication == 1 &&
674 sensitive_data.keys[0] == NULL &&
675 sensitive_data.keys[1] == NULL &&
676 sensitive_data.keys[2] == NULL) {
677 sensitive_data.keys[1] = key_load_public(
678 _PATH_HOST_DSA_KEY_FILE, NULL);
679 sensitive_data.keys[2] = key_load_public(
680 _PATH_HOST_RSA_KEY_FILE, NULL);
681 sensitive_data.external_keysign = 1;
685 * Get rid of any extra privileges that we may have. We will no
686 * longer need them. Also, extra privileges could make it very hard
687 * to read identity files and other non-world-readable files from the
688 * user's home directory if it happens to be on a NFS volume where
689 * root is mapped to nobody.
691 if (original_effective_uid == 0) {
693 permanently_set_uid(pw);
697 * Now that we are back to our own permissions, create ~/.ssh
698 * directory if it doesn\'t already exist.
700 snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
701 if (stat(buf, &st) < 0)
702 if (mkdir(buf, 0700) < 0)
703 error("Could not create directory '%.200s'.", buf);
705 /* load options.identity_files */
706 load_public_identity_files();
708 /* Expand ~ in known host file names. */
710 options.system_hostfile =
711 tilde_expand_filename(options.system_hostfile, original_real_uid);
712 options.user_hostfile =
713 tilde_expand_filename(options.user_hostfile, original_real_uid);
714 options.system_hostfile2 =
715 tilde_expand_filename(options.system_hostfile2, original_real_uid);
716 options.user_hostfile2 =
717 tilde_expand_filename(options.user_hostfile2, original_real_uid);
719 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
721 /* Log into the remote system. This never returns if the login fails. */
722 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw);
724 /* We no longer need the private host keys. Clear them now. */
725 if (sensitive_data.nkeys != 0) {
726 for (i = 0; i < sensitive_data.nkeys; i++) {
727 if (sensitive_data.keys[i] != NULL) {
728 /* Destroys contents safely */
729 debug3("clear hostkey %d", i);
730 key_free(sensitive_data.keys[i]);
731 sensitive_data.keys[i] = NULL;
734 xfree(sensitive_data.keys);
736 for (i = 0; i < options.num_identity_files; i++) {
737 if (options.identity_files[i]) {
738 xfree(options.identity_files[i]);
739 options.identity_files[i] = NULL;
741 if (options.identity_keys[i]) {
742 key_free(options.identity_keys[i]);
743 options.identity_keys[i] = NULL;
747 exit_status = compat20 ? ssh_session2() : ssh_session();
750 if (options.control_path != NULL && control_fd != -1)
751 unlink(options.control_path);
754 * Send SIGHUP to proxy command if used. We don't wait() in
755 * case it hangs and instead rely on init to reap the child
757 if (proxy_command_pid > 1)
758 kill(proxy_command_pid, SIGHUP);
764 ssh_init_forwarding(void)
769 /* Initiate local TCP/IP port forwardings. */
770 for (i = 0; i < options.num_local_forwards; i++) {
771 debug("Local connections to %.200s:%d forwarded to remote "
773 (options.local_forwards[i].listen_host == NULL) ?
774 (options.gateway_ports ? "*" : "LOCALHOST") :
775 options.local_forwards[i].listen_host,
776 options.local_forwards[i].listen_port,
777 options.local_forwards[i].connect_host,
778 options.local_forwards[i].connect_port);
779 success += channel_setup_local_fwd_listener(
780 options.local_forwards[i].listen_host,
781 options.local_forwards[i].listen_port,
782 options.local_forwards[i].connect_host,
783 options.local_forwards[i].connect_port,
784 options.gateway_ports);
786 if (i > 0 && success == 0)
787 error("Could not request local forwarding.");
789 /* Initiate remote TCP/IP port forwardings. */
790 for (i = 0; i < options.num_remote_forwards; i++) {
791 debug("Remote connections from %.200s:%d forwarded to "
792 "local address %.200s:%d",
793 (options.remote_forwards[i].listen_host == NULL) ?
794 (options.gateway_ports ? "*" : "LOCALHOST") :
795 options.remote_forwards[i].listen_host,
796 options.remote_forwards[i].listen_port,
797 options.remote_forwards[i].connect_host,
798 options.remote_forwards[i].connect_port);
799 channel_request_remote_forwarding(
800 options.remote_forwards[i].listen_host,
801 options.remote_forwards[i].listen_port,
802 options.remote_forwards[i].connect_host,
803 options.remote_forwards[i].connect_port);
808 check_agent_present(void)
810 if (options.forward_agent) {
811 /* Clear agent forwarding if we don\'t have an agent. */
812 if (!ssh_agent_present())
813 options.forward_agent = 0;
827 /* Enable compression if requested. */
828 if (options.compression) {
829 debug("Requesting compression at level %d.", options.compression_level);
831 if (options.compression_level < 1 || options.compression_level > 9)
832 fatal("Compression level must be from 1 (fast) to 9 (slow, best).");
834 /* Send the request. */
835 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
836 packet_put_int(options.compression_level);
839 type = packet_read();
840 if (type == SSH_SMSG_SUCCESS)
841 packet_start_compression(options.compression_level);
842 else if (type == SSH_SMSG_FAILURE)
843 logit("Warning: Remote host refused compression.");
845 packet_disconnect("Protocol error waiting for compression response.");
847 /* Allocate a pseudo tty if appropriate. */
849 debug("Requesting pty.");
851 /* Start the packet. */
852 packet_start(SSH_CMSG_REQUEST_PTY);
854 /* Store TERM in the packet. There is no limit on the
855 length of the string. */
859 packet_put_cstring(cp);
861 /* Store window size in the packet. */
862 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
863 memset(&ws, 0, sizeof(ws));
864 packet_put_int(ws.ws_row);
865 packet_put_int(ws.ws_col);
866 packet_put_int(ws.ws_xpixel);
867 packet_put_int(ws.ws_ypixel);
869 /* Store tty modes in the packet. */
870 tty_make_modes(fileno(stdin), NULL);
872 /* Send the packet, and wait for it to leave. */
876 /* Read response from the server. */
877 type = packet_read();
878 if (type == SSH_SMSG_SUCCESS) {
881 } else if (type == SSH_SMSG_FAILURE)
882 logit("Warning: Remote host failed or refused to allocate a pseudo tty.");
884 packet_disconnect("Protocol error waiting for pty request response.");
886 /* Request X11 forwarding if enabled and DISPLAY is set. */
887 display = getenv("DISPLAY");
888 if (options.forward_x11 && display != NULL) {
890 /* Get reasonable local authentication information. */
891 client_x11_get_proto(display, options.xauth_location,
892 options.forward_x11_trusted, &proto, &data);
893 /* Request forwarding with authentication spoofing. */
894 debug("Requesting X11 forwarding with authentication spoofing.");
895 x11_request_forwarding_with_spoofing(0, display, proto, data);
897 /* Read response from the server. */
898 type = packet_read();
899 if (type == SSH_SMSG_SUCCESS) {
901 } else if (type == SSH_SMSG_FAILURE) {
902 logit("Warning: Remote host denied X11 forwarding.");
904 packet_disconnect("Protocol error waiting for X11 forwarding");
907 /* Tell the packet module whether this is an interactive session. */
908 packet_set_interactive(interactive);
910 /* Request authentication agent forwarding if appropriate. */
911 check_agent_present();
913 if (options.forward_agent) {
914 debug("Requesting authentication agent forwarding.");
915 auth_request_forwarding();
917 /* Read response from the server. */
918 type = packet_read();
920 if (type != SSH_SMSG_SUCCESS)
921 logit("Warning: Remote host denied authentication agent forwarding.");
924 /* Initiate port forwardings. */
925 ssh_init_forwarding();
927 /* If requested, let ssh continue in the background. */
928 if (fork_after_authentication_flag)
929 if (daemon(1, 1) < 0)
930 fatal("daemon() failed: %.200s", strerror(errno));
933 * If a command was specified on the command line, execute the
934 * command now. Otherwise request the server to start a shell.
936 if (buffer_len(&command) > 0) {
937 int len = buffer_len(&command);
940 debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command));
941 packet_start(SSH_CMSG_EXEC_CMD);
942 packet_put_string(buffer_ptr(&command), buffer_len(&command));
946 debug("Requesting shell.");
947 packet_start(SSH_CMSG_EXEC_SHELL);
952 /* Enter the interactive session. */
953 return client_loop(have_tty, tty_flag ?
954 options.escape_char : SSH_ESCAPECHAR_NONE, 0);
958 ssh_subsystem_reply(int type, u_int32_t seq, void *ctxt)
962 id = packet_get_int();
963 len = buffer_len(&command);
967 if (type == SSH2_MSG_CHANNEL_FAILURE)
968 fatal("Request for subsystem '%.*s' failed on channel %d",
969 len, (u_char *)buffer_ptr(&command), id);
973 client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt)
977 i = client_global_request_id++;
978 if (i >= options.num_remote_forwards)
980 debug("remote forward %s for: listen %d, connect %s:%d",
981 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
982 options.remote_forwards[i].listen_port,
983 options.remote_forwards[i].connect_host,
984 options.remote_forwards[i].connect_port);
985 if (type == SSH2_MSG_REQUEST_FAILURE)
986 logit("Warning: remote port forwarding failed for listen "
987 "port %d", options.remote_forwards[i].listen_port);
991 ssh_control_listener(void)
993 struct sockaddr_un addr;
997 if (options.control_path == NULL ||
998 options.control_master == SSHCTL_MASTER_NO)
1001 debug("setting up multiplex master socket");
1003 memset(&addr, '\0', sizeof(addr));
1004 addr.sun_family = AF_UNIX;
1005 addr_len = offsetof(struct sockaddr_un, sun_path) +
1006 strlen(options.control_path) + 1;
1008 if (strlcpy(addr.sun_path, options.control_path,
1009 sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1010 fatal("ControlPath too long");
1012 if ((control_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1013 fatal("%s socket(): %s\n", __func__, strerror(errno));
1015 old_umask = umask(0177);
1016 if (bind(control_fd, (struct sockaddr*)&addr, addr_len) == -1) {
1018 if (errno == EINVAL || errno == EADDRINUSE)
1019 fatal("ControlSocket %s already exists",
1020 options.control_path);
1022 fatal("%s bind(): %s\n", __func__, strerror(errno));
1026 if (listen(control_fd, 64) == -1)
1027 fatal("%s listen(): %s\n", __func__, strerror(errno));
1029 set_nonblock(control_fd);
1032 /* request pty/x11/agent/tcpfwd/shell for channel */
1034 ssh_session2_setup(int id, void *arg)
1036 extern char **environ;
1037 const char *display;
1038 int interactive = tty_flag;
1040 display = getenv("DISPLAY");
1041 if (options.forward_x11 && display != NULL) {
1043 /* Get reasonable local authentication information. */
1044 client_x11_get_proto(display, options.xauth_location,
1045 options.forward_x11_trusted, &proto, &data);
1046 /* Request forwarding with authentication spoofing. */
1047 debug("Requesting X11 forwarding with authentication spoofing.");
1048 x11_request_forwarding_with_spoofing(id, display, proto, data);
1050 /* XXX wait for reply */
1053 check_agent_present();
1054 if (options.forward_agent) {
1055 debug("Requesting authentication agent forwarding.");
1056 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1060 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1061 NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply);
1063 packet_set_interactive(interactive);
1066 /* open new channel for a session */
1068 ssh_session2_open(void)
1071 int window, packetmax, in, out, err;
1073 if (stdin_null_flag) {
1074 in = open(_PATH_DEVNULL, O_RDONLY);
1076 in = dup(STDIN_FILENO);
1078 out = dup(STDOUT_FILENO);
1079 err = dup(STDERR_FILENO);
1081 if (in < 0 || out < 0 || err < 0)
1082 fatal("dup() in/out/err failed");
1084 /* enable nonblocking unless tty */
1092 window = CHAN_SES_WINDOW_DEFAULT;
1093 packetmax = CHAN_SES_PACKET_DEFAULT;
1099 "session", SSH_CHANNEL_OPENING, in, out, err,
1100 window, packetmax, CHAN_EXTENDED_WRITE,
1101 "client-session", /*nonblock*/0);
1103 debug3("ssh_session2_open: channel_new: %d", c->self);
1105 channel_send_open(c->self);
1107 channel_register_confirm(c->self, ssh_session2_setup, NULL);
1117 /* XXX should be pre-session */
1118 ssh_init_forwarding();
1119 ssh_control_listener();
1121 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1122 id = ssh_session2_open();
1124 /* If requested, let ssh continue in the background. */
1125 if (fork_after_authentication_flag)
1126 if (daemon(1, 1) < 0)
1127 fatal("daemon() failed: %.200s", strerror(errno));
1129 return client_loop(tty_flag, tty_flag ?
1130 options.escape_char : SSH_ESCAPECHAR_NONE, id);
1134 load_public_identity_files(void)
1142 if (options.smartcard_device != NULL &&
1143 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1144 (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL ) {
1146 for (i = 0; keys[i] != NULL; i++) {
1148 memmove(&options.identity_files[1], &options.identity_files[0],
1149 sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1));
1150 memmove(&options.identity_keys[1], &options.identity_keys[0],
1151 sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1));
1152 options.num_identity_files++;
1153 options.identity_keys[0] = keys[i];
1154 options.identity_files[0] = sc_get_key_label(keys[i]);
1156 if (options.num_identity_files > SSH_MAX_IDENTITY_FILES)
1157 options.num_identity_files = SSH_MAX_IDENTITY_FILES;
1161 #endif /* SMARTCARD */
1162 for (; i < options.num_identity_files; i++) {
1163 filename = tilde_expand_filename(options.identity_files[i],
1165 public = key_load_public(filename, NULL);
1166 debug("identity file %s type %d", filename,
1167 public ? public->type : -1);
1168 xfree(options.identity_files[i]);
1169 options.identity_files[i] = filename;
1170 options.identity_keys[i] = public;
1175 control_client_sighandler(int signo)
1177 control_client_terminate = signo;
1181 control_client_sigrelay(int signo)
1183 if (control_server_pid > 1)
1184 kill(control_server_pid, signo);
1188 env_permitted(char *env)
1191 char name[1024], *cp;
1193 strlcpy(name, env, sizeof(name));
1194 if ((cp = strchr(name, '=')) == NULL)
1199 for (i = 0; i < options.num_send_env; i++)
1200 if (match_pattern(name, options.send_env[i]))
1207 control_client(const char *path)
1209 struct sockaddr_un addr;
1210 int i, r, fd, sock, exitval, num_env, addr_len;
1213 extern char **environ;
1216 if (mux_command == 0)
1217 mux_command = SSHMUX_COMMAND_OPEN;
1219 switch (options.control_master) {
1220 case SSHCTL_MASTER_AUTO:
1221 case SSHCTL_MASTER_AUTO_ASK:
1222 debug("auto-mux: Trying existing master");
1224 case SSHCTL_MASTER_NO:
1230 memset(&addr, '\0', sizeof(addr));
1231 addr.sun_family = AF_UNIX;
1232 addr_len = offsetof(struct sockaddr_un, sun_path) +
1235 if (strlcpy(addr.sun_path, path,
1236 sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1237 fatal("ControlPath too long");
1239 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1240 fatal("%s socket(): %s", __func__, strerror(errno));
1242 if (connect(sock, (struct sockaddr*)&addr, addr_len) == -1) {
1243 if (mux_command != SSHMUX_COMMAND_OPEN) {
1244 fatal("Control socket connect(%.100s): %s", path,
1247 if (errno == ENOENT)
1248 debug("Control socket \"%.100s\" does not exist", path);
1250 error("Control socket connect(%.100s): %s", path,
1257 if (stdin_null_flag) {
1258 if ((fd = open(_PATH_DEVNULL, O_RDONLY)) == -1)
1259 fatal("open(/dev/null): %s", strerror(errno));
1260 if (dup2(fd, STDIN_FILENO) == -1)
1261 fatal("dup2: %s", strerror(errno));
1262 if (fd > STDERR_FILENO)
1266 term = getenv("TERM");
1270 flags |= SSHMUX_FLAG_TTY;
1272 flags |= SSHMUX_FLAG_SUBSYS;
1273 if (options.forward_x11)
1274 flags |= SSHMUX_FLAG_X11_FWD;
1275 if (options.forward_agent)
1276 flags |= SSHMUX_FLAG_AGENT_FWD;
1280 /* Send our command to server */
1281 buffer_put_int(&m, mux_command);
1282 buffer_put_int(&m, flags);
1283 if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
1284 fatal("%s: msg_send", __func__);
1287 /* Get authorisation status and PID of controlee */
1288 if (ssh_msg_recv(sock, &m) == -1)
1289 fatal("%s: msg_recv", __func__);
1290 if (buffer_get_char(&m) != SSHMUX_VER)
1291 fatal("%s: wrong version", __func__);
1292 if (buffer_get_int(&m) != 1)
1293 fatal("Connection to master denied");
1294 control_server_pid = buffer_get_int(&m);
1298 switch (mux_command) {
1299 case SSHMUX_COMMAND_ALIVE_CHECK:
1300 fprintf(stderr, "Master running (pid=%d)\r\n",
1301 control_server_pid);
1303 case SSHMUX_COMMAND_TERMINATE:
1304 fprintf(stderr, "Exit request sent.\r\n");
1306 case SSHMUX_COMMAND_OPEN:
1307 /* continue below */
1310 fatal("silly mux_command %d", mux_command);
1313 /* SSHMUX_COMMAND_OPEN */
1314 buffer_put_cstring(&m, term ? term : "");
1315 buffer_append(&command, "\0", 1);
1316 buffer_put_cstring(&m, buffer_ptr(&command));
1318 if (options.num_send_env == 0 || environ == NULL) {
1319 buffer_put_int(&m, 0);
1321 /* Pass environment */
1323 for (i = 0; environ[i] != NULL; i++)
1324 if (env_permitted(environ[i]))
1325 num_env++; /* Count */
1327 buffer_put_int(&m, num_env);
1329 for (i = 0; environ[i] != NULL && num_env >= 0; i++)
1330 if (env_permitted(environ[i])) {
1332 buffer_put_cstring(&m, environ[i]);
1336 if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
1337 fatal("%s: msg_send", __func__);
1339 mm_send_fd(sock, STDIN_FILENO);
1340 mm_send_fd(sock, STDOUT_FILENO);
1341 mm_send_fd(sock, STDERR_FILENO);
1343 /* Wait for reply, so master has a chance to gather ttymodes */
1345 if (ssh_msg_recv(sock, &m) == -1)
1346 fatal("%s: msg_recv", __func__);
1347 if (buffer_get_char(&m) != SSHMUX_VER)
1348 fatal("%s: wrong version", __func__);
1351 signal(SIGHUP, control_client_sighandler);
1352 signal(SIGINT, control_client_sighandler);
1353 signal(SIGTERM, control_client_sighandler);
1354 signal(SIGWINCH, control_client_sigrelay);
1359 /* Stick around until the controlee closes the client_fd */
1361 for (;!control_client_terminate;) {
1362 r = read(sock, &exitval, sizeof(exitval));
1364 debug2("Received EOF from master");
1368 debug2("Received exit status from master %d", exitval);
1369 if (r == -1 && errno != EINTR)
1370 fatal("%s: read %s", __func__, strerror(errno));
1373 if (control_client_terminate)
1374 debug2("Exiting on signal %d", control_client_terminate);
1380 if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1381 fprintf(stderr, "Connection to master closed.\r\n");