1 /* $OpenBSD: ssh.c,v 1.356 2011/01/06 22:23:53 djm Exp $ */
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * Ssh client program. This program can be used to log into a remote machine.
7 * The software supports strong authentication, encryption, and forwarding
8 * of X11, TCP/IP, and authentication connections.
10 * As far as I am concerned, the code I have written for this software
11 * can be used freely for any purpose. Any derived versions of this
12 * software must be clearly marked as such, and if the derived work is
13 * incompatible with the protocol description in the RFC file, it must be
14 * called by a name other than "ssh" or "Secure Shell".
16 * Copyright (c) 1999 Niels Provos. All rights reserved.
17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved.
19 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
20 * in Canada (German citizen).
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
25 * 1. Redistributions of source code must retain the above copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
45 #include <sys/types.h>
46 #ifdef HAVE_SYS_STAT_H
47 # include <sys/stat.h>
49 #include <sys/resource.h>
50 #include <sys/ioctl.h>
51 #include <sys/param.h>
52 #include <sys/socket.h>
71 #include <netinet/in.h>
72 #include <arpa/inet.h>
74 #include <openssl/evp.h>
75 #include <openssl/err.h>
76 #include "openbsd-compat/openssl-compat.h"
77 #include "openbsd-compat/sys-queue.h"
92 #include "pathnames.h"
94 #include "clientloop.h"
97 #include "sshconnect.h"
109 #include "ssh-pkcs11.h"
112 extern char *__progname;
114 /* Flag indicating whether debug mode is on. May be set on the command line. */
117 /* Flag indicating whether a tty should be allocated */
120 int force_tty_flag = 0;
122 /* don't exec a shell */
123 int no_shell_flag = 0;
126 * Flag indicating that nothing should be read from stdin. This can be set
127 * on the command line.
129 int stdin_null_flag = 0;
132 * Flag indicating that the current process should be backgrounded and
133 * a new slave launched in the foreground for ControlPersist.
135 int need_controlpersist_detach = 0;
137 /* Copies of flags for ControlPersist foreground slave */
138 int ostdin_null_flag, ono_shell_flag, ono_tty_flag, otty_flag;
141 * Flag indicating that ssh should fork after authentication. This is useful
142 * so that the passphrase can be entered manually, and then ssh goes to the
145 int fork_after_authentication_flag = 0;
147 /* forward stdio to remote host and port */
148 char *stdio_forward_host = NULL;
149 int stdio_forward_port = 0;
152 * General data structure for command line options and options configurable
153 * in configuration files. See readconf.h.
157 /* optional user configfile */
161 * Name of the host we are connecting to. This is the name given on the
162 * command line, or the HostName specified for the user-supplied name in a
163 * configuration file.
167 /* socket address the host resolves to */
168 struct sockaddr_storage hostaddr;
170 /* Private host keys. */
171 Sensitive sensitive_data;
173 /* Original real UID. */
174 uid_t original_real_uid;
175 uid_t original_effective_uid;
177 /* command to be executed */
180 /* Should we execute a command or invoke a subsystem? */
181 int subsystem_flag = 0;
183 /* # of replies received for global requests */
184 static int remote_forward_confirms_received = 0;
187 extern int muxserver_sock;
188 extern u_int muxclient_command;
190 /* Prints a help message to the user. This function never returns. */
196 "usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n"
197 " [-D [bind_address:]port] [-e escape_char] [-F configfile]\n"
198 " [-I pkcs11] [-i identity_file]\n"
199 " [-L [bind_address:]port:host:hostport]\n"
200 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
201 " [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
202 " [-W host:port] [-w local_tun[:remote_tun]]\n"
203 " [user@]hostname [command]\n"
208 static int ssh_session(void);
209 static int ssh_session2(void);
210 static void load_public_identity_files(void);
211 static void main_sigchld_handler(int);
213 /* from muxclient.c */
214 void muxclient(const char *);
215 void muxserver_listen(void);
218 * Main program for the ssh client.
221 main(int ac, char **av)
223 int i, r, opt, exit_status, use_syslog;
224 char *p, *cp, *line, *argv0, buf[MAXPATHLEN], *host_arg;
227 int dummy, timeout_ms;
228 extern int optind, optreset;
233 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
236 __progname = ssh_get_progname(av[0]);
240 * Discard other fds that are hanging around. These can cause problem
241 * with backgrounded ssh processes started by ControlPersist.
243 closefrom(STDERR_FILENO + 1);
246 * Save the original real uid. It will be needed later (uid-swapping
247 * may clobber the real uid).
249 original_real_uid = getuid();
250 original_effective_uid = geteuid();
253 * Use uid-swapping to give up root privileges for the duration of
254 * option processing. We will re-instantiate the rights when we are
255 * ready to create the privileged port, and will permanently drop
256 * them when the port has been created (actually, when the connection
257 * has been made, as we may need to create the port several times).
261 #ifdef HAVE_SETRLIMIT
262 /* If we are installed setuid root be careful to not drop core. */
263 if (original_real_uid != original_effective_uid) {
265 rlim.rlim_cur = rlim.rlim_max = 0;
266 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
267 fatal("setrlimit failed: %.100s", strerror(errno));
271 pw = getpwuid(original_real_uid);
273 logit("You don't exist, go away!");
276 /* Take a copy of the returned structure. */
280 * Set our umask to something reasonable, as some files are created
281 * with the default umask. This will make them world-readable but
282 * writable only by the owner, which is ok for all files for which we
283 * don't set the modes explicitly.
288 * Initialize option structure to indicate that no values have been
291 initialize_options(&options);
293 /* Parse command-line arguments. */
299 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
300 "ACD:F:I:KL:MNO:PR:S:TVw:W:XYy")) != -1) {
303 options.protocol = SSH_PROTO_1;
306 options.protocol = SSH_PROTO_2;
309 options.address_family = AF_INET;
312 options.address_family = AF_INET6;
318 fork_after_authentication_flag = 1;
322 options.forward_x11 = 0;
325 options.forward_x11 = 1;
331 options.forward_x11 = 1;
332 options.forward_x11_trusted = 1;
335 options.gateway_ports = 1;
338 if (stdio_forward_host != NULL)
339 fatal("Cannot specify multiplexing "
341 else if (muxclient_command != 0)
342 fatal("Multiplexing command already specified");
343 if (strcmp(optarg, "check") == 0)
344 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
345 else if (strcmp(optarg, "forward") == 0)
346 muxclient_command = SSHMUX_COMMAND_FORWARD;
347 else if (strcmp(optarg, "exit") == 0)
348 muxclient_command = SSHMUX_COMMAND_TERMINATE;
350 fatal("Invalid multiplex command.");
352 case 'P': /* deprecated */
353 options.use_privileged_port = 0;
356 options.forward_agent = 0;
359 options.forward_agent = 1;
362 options.gss_deleg_creds = 0;
365 options.gss_authentication = 1;
366 options.gss_deleg_creds = 1;
369 if (stat(optarg, &st) < 0) {
370 fprintf(stderr, "Warning: Identity file %s "
371 "not accessible: %s.\n", optarg,
375 if (options.num_identity_files >=
376 SSH_MAX_IDENTITY_FILES)
377 fatal("Too many identity files specified "
378 "(max %d)", SSH_MAX_IDENTITY_FILES);
379 options.identity_files[options.num_identity_files++] =
384 options.pkcs11_provider = xstrdup(optarg);
386 fprintf(stderr, "no support for PKCS#11.\n");
395 if (debug_flag == 0) {
397 options.log_level = SYSLOG_LEVEL_DEBUG1;
399 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
405 fprintf(stderr, "%s, %s\n",
406 SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
411 if (options.tun_open == -1)
412 options.tun_open = SSH_TUNMODE_DEFAULT;
413 options.tun_local = a2tun(optarg, &options.tun_remote);
414 if (options.tun_local == SSH_TUNID_ERR) {
416 "Bad tun device '%s'\n", optarg);
421 if (stdio_forward_host != NULL)
422 fatal("stdio forward already specified");
423 if (muxclient_command != 0)
424 fatal("Cannot specify stdio forward with -O");
425 if (parse_forward(&fwd, optarg, 1, 0)) {
426 stdio_forward_host = fwd.listen_host;
427 stdio_forward_port = fwd.listen_port;
428 xfree(fwd.connect_host);
431 "Bad stdio forwarding specification '%s'\n",
437 options.clear_forwardings = 1;
438 options.exit_on_forward_failure = 1;
441 options.log_level = SYSLOG_LEVEL_QUIET;
444 if (optarg[0] == '^' && optarg[2] == 0 &&
445 (u_char) optarg[1] >= 64 &&
446 (u_char) optarg[1] < 128)
447 options.escape_char = (u_char) optarg[1] & 31;
448 else if (strlen(optarg) == 1)
449 options.escape_char = (u_char) optarg[0];
450 else if (strcmp(optarg, "none") == 0)
451 options.escape_char = SSH_ESCAPECHAR_NONE;
453 fprintf(stderr, "Bad escape character '%s'.\n",
459 if (ciphers_valid(optarg)) {
461 options.ciphers = xstrdup(optarg);
462 options.cipher = SSH_CIPHER_INVALID;
465 options.cipher = cipher_number(optarg);
466 if (options.cipher == -1) {
468 "Unknown cipher type '%s'\n",
472 if (options.cipher == SSH_CIPHER_3DES)
473 options.ciphers = "3des-cbc";
474 else if (options.cipher == SSH_CIPHER_BLOWFISH)
475 options.ciphers = "blowfish-cbc";
477 options.ciphers = (char *)-1;
481 if (mac_valid(optarg))
482 options.macs = xstrdup(optarg);
484 fprintf(stderr, "Unknown mac type '%s'\n",
490 if (options.control_master == SSHCTL_MASTER_YES)
491 options.control_master = SSHCTL_MASTER_ASK;
493 options.control_master = SSHCTL_MASTER_YES;
496 options.port = a2port(optarg);
497 if (options.port <= 0) {
498 fprintf(stderr, "Bad port '%s'\n", optarg);
503 options.user = optarg;
507 if (parse_forward(&fwd, optarg, 0, 0))
508 add_local_forward(&options, &fwd);
511 "Bad local forwarding specification '%s'\n",
518 if (parse_forward(&fwd, optarg, 0, 1)) {
519 add_remote_forward(&options, &fwd);
522 "Bad remote forwarding specification "
529 if (parse_forward(&fwd, optarg, 1, 0)) {
530 add_local_forward(&options, &fwd);
533 "Bad dynamic forwarding specification "
540 options.compression = 1;
548 line = xstrdup(optarg);
549 if (process_config_line(&options, host ? host : "",
550 line, "command-line", 0, &dummy) != 0)
556 /* ensure that the user doesn't try to backdoor a */
557 /* null cipher switch on an interactive session */
558 /* so explicitly disable it no matter what */
559 options.none_switch=0;
565 if (options.control_path != NULL)
566 free(options.control_path);
567 options.control_path = xstrdup(optarg);
570 options.bind_address = optarg;
583 if (ac > 0 && !host) {
584 if (strrchr(*av, '@')) {
586 cp = strrchr(p, '@');
587 if (cp == NULL || cp == p)
595 optind = optreset = 1;
601 /* Check that we got a host name. */
605 OpenSSL_add_all_algorithms();
606 ERR_load_crypto_strings();
608 /* Initialize the command to execute on remote host. */
609 buffer_init(&command);
612 * Save the command to execute on the remote host in a buffer. There
613 * is no limit on the length of the command, except by the maximum
614 * packet size. Also sets the tty flag if there is no command.
617 /* No command specified - execute shell on a tty. */
619 if (subsystem_flag) {
621 "You must specify a subsystem to invoke.\n");
625 /* A command has been specified. Store it into the buffer. */
626 for (i = 0; i < ac; i++) {
628 buffer_append(&command, " ", 1);
629 buffer_append(&command, av[i], strlen(av[i]));
633 /* Cannot fork to background if no command. */
634 if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
636 fatal("Cannot fork into background without a command "
639 /* Allocate a tty by default if no command specified. */
640 if (buffer_len(&command) == 0)
644 if (no_tty_flag || muxclient_command != 0)
646 /* Do not allocate a tty if stdin is not a tty. */
647 if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
649 logit("Pseudo-terminal will not be allocated because "
650 "stdin is not a terminal.");
655 * Initialize "log" output. Since we are the client all output
656 * actually goes to stderr.
659 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
660 SYSLOG_FACILITY_USER, !use_syslog);
663 * Read per-user configuration file. Ignore the system wide config
664 * file if the user specifies a config file on the command line.
666 if (config != NULL) {
667 if (!read_config_file(config, host, &options, 0))
668 fatal("Can't open user config file %.100s: "
669 "%.100s", config, strerror(errno));
671 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
672 _PATH_SSH_USER_CONFFILE);
673 if (r > 0 && (size_t)r < sizeof(buf))
674 (void)read_config_file(buf, host, &options, 1);
676 /* Read systemwide configuration file after use config. */
677 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
681 /* Fill configuration defaults. */
682 fill_default_options(&options);
684 channel_set_af(options.address_family);
687 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
691 if (options.user == NULL)
692 options.user = xstrdup(pw->pw_name);
694 /* Get default port if port has not been set. */
695 if (options.port == 0) {
696 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
697 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
700 /* preserve host name given on command line for %n expansion */
702 if (options.hostname != NULL) {
703 host = percent_expand(options.hostname,
704 "h", host, (char *)NULL);
707 if (options.local_command != NULL) {
708 char thishost[NI_MAXHOST];
710 if (gethostname(thishost, sizeof(thishost)) == -1)
711 fatal("gethostname: %s", strerror(errno));
712 snprintf(buf, sizeof(buf), "%d", options.port);
713 debug3("expanding LocalCommand: %s", options.local_command);
714 cp = options.local_command;
715 options.local_command = percent_expand(cp, "d", pw->pw_dir,
716 "h", host, "l", thishost, "n", host_arg, "r", options.user,
717 "p", buf, "u", pw->pw_name, (char *)NULL);
718 debug3("expanded LocalCommand: %s", options.local_command);
722 /* force lowercase for hostkey matching */
723 if (options.host_key_alias != NULL) {
724 for (p = options.host_key_alias; *p; p++)
726 *p = (char)tolower(*p);
729 if (options.proxy_command != NULL &&
730 strcmp(options.proxy_command, "none") == 0) {
731 xfree(options.proxy_command);
732 options.proxy_command = NULL;
734 if (options.control_path != NULL &&
735 strcmp(options.control_path, "none") == 0) {
736 xfree(options.control_path);
737 options.control_path = NULL;
740 if (options.control_path != NULL) {
741 char thishost[NI_MAXHOST];
743 if (gethostname(thishost, sizeof(thishost)) == -1)
744 fatal("gethostname: %s", strerror(errno));
745 snprintf(buf, sizeof(buf), "%d", options.port);
746 cp = tilde_expand_filename(options.control_path,
748 xfree(options.control_path);
749 options.control_path = percent_expand(cp, "p", buf, "h", host,
750 "r", options.user, "l", thishost, (char *)NULL);
753 if (muxclient_command != 0 && options.control_path == NULL)
754 fatal("No ControlPath specified for \"-O\" command");
755 if (options.control_path != NULL)
756 muxclient(options.control_path);
758 timeout_ms = options.connection_timeout * 1000;
760 /* Open a connection to the remote host. */
761 if (ssh_connect(host, &hostaddr, options.port,
762 options.address_family, options.connection_attempts, &timeout_ms,
763 options.tcp_keep_alive,
765 options.use_privileged_port,
767 original_effective_uid == 0 && options.use_privileged_port,
769 options.proxy_command) != 0)
773 debug3("timeout: %d ms remain after connect", timeout_ms);
776 * If we successfully made the connection, load the host private key
777 * in case we will need it later for combined rsa-rhosts
778 * authentication. This must be done before releasing extra
779 * privileges, because the file is only readable by root.
780 * If we cannot access the private keys, load the public keys
781 * instead and try to execute the ssh-keysign helper instead.
783 sensitive_data.nkeys = 0;
784 sensitive_data.keys = NULL;
785 sensitive_data.external_keysign = 0;
786 if (options.rhosts_rsa_authentication ||
787 options.hostbased_authentication) {
788 sensitive_data.nkeys = 7;
789 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
791 for (i = 0; i < sensitive_data.nkeys; i++)
792 sensitive_data.keys[i] = NULL;
795 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
796 _PATH_HOST_KEY_FILE, "", NULL, NULL);
797 sensitive_data.keys[1] = key_load_private_cert(KEY_DSA,
798 _PATH_HOST_DSA_KEY_FILE, "", NULL);
799 #ifdef OPENSSL_HAS_ECC
800 sensitive_data.keys[2] = key_load_private_cert(KEY_ECDSA,
801 _PATH_HOST_ECDSA_KEY_FILE, "", NULL);
803 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA,
804 _PATH_HOST_RSA_KEY_FILE, "", NULL);
805 sensitive_data.keys[4] = key_load_private_type(KEY_DSA,
806 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
807 #ifdef OPENSSL_HAS_ECC
808 sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA,
809 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL);
811 sensitive_data.keys[6] = key_load_private_type(KEY_RSA,
812 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
815 if (options.hostbased_authentication == 1 &&
816 sensitive_data.keys[0] == NULL &&
817 sensitive_data.keys[4] == NULL &&
818 sensitive_data.keys[5] == NULL &&
819 sensitive_data.keys[6] == NULL) {
820 sensitive_data.keys[1] = key_load_cert(
821 _PATH_HOST_DSA_KEY_FILE);
822 #ifdef OPENSSL_HAS_ECC
823 sensitive_data.keys[2] = key_load_cert(
824 _PATH_HOST_ECDSA_KEY_FILE);
826 sensitive_data.keys[3] = key_load_cert(
827 _PATH_HOST_RSA_KEY_FILE);
828 sensitive_data.keys[4] = key_load_public(
829 _PATH_HOST_DSA_KEY_FILE, NULL);
830 #ifdef OPENSSL_HAS_ECC
831 sensitive_data.keys[5] = key_load_public(
832 _PATH_HOST_ECDSA_KEY_FILE, NULL);
834 sensitive_data.keys[6] = key_load_public(
835 _PATH_HOST_RSA_KEY_FILE, NULL);
836 sensitive_data.external_keysign = 1;
840 * Get rid of any extra privileges that we may have. We will no
841 * longer need them. Also, extra privileges could make it very hard
842 * to read identity files and other non-world-readable files from the
843 * user's home directory if it happens to be on a NFS volume where
844 * root is mapped to nobody.
846 if (original_effective_uid == 0) {
848 permanently_set_uid(pw);
852 * Now that we are back to our own permissions, create ~/.ssh
853 * directory if it doesn't already exist.
855 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir,
856 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
857 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) {
859 ssh_selinux_setfscreatecon(buf);
861 if (mkdir(buf, 0700) < 0)
862 error("Could not create directory '%.200s'.", buf);
864 ssh_selinux_setfscreatecon(NULL);
867 /* load options.identity_files */
868 load_public_identity_files();
870 /* Expand ~ in known host file names. */
872 options.system_hostfile =
873 tilde_expand_filename(options.system_hostfile, original_real_uid);
874 options.user_hostfile =
875 tilde_expand_filename(options.user_hostfile, original_real_uid);
876 options.system_hostfile2 =
877 tilde_expand_filename(options.system_hostfile2, original_real_uid);
878 options.user_hostfile2 =
879 tilde_expand_filename(options.user_hostfile2, original_real_uid);
881 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
882 signal(SIGCHLD, main_sigchld_handler);
884 /* Log into the remote system. Never returns if the login fails. */
885 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
886 options.port, pw, timeout_ms);
888 if (packet_connection_is_on_socket()) {
889 verbose("Authenticated to %s ([%s]:%d).", host,
890 get_remote_ipaddr(), get_remote_port());
892 verbose("Authenticated to %s (via proxy).", host);
895 /* We no longer need the private host keys. Clear them now. */
896 if (sensitive_data.nkeys != 0) {
897 for (i = 0; i < sensitive_data.nkeys; i++) {
898 if (sensitive_data.keys[i] != NULL) {
899 /* Destroys contents safely */
900 debug3("clear hostkey %d", i);
901 key_free(sensitive_data.keys[i]);
902 sensitive_data.keys[i] = NULL;
905 xfree(sensitive_data.keys);
907 for (i = 0; i < options.num_identity_files; i++) {
908 if (options.identity_files[i]) {
909 xfree(options.identity_files[i]);
910 options.identity_files[i] = NULL;
912 if (options.identity_keys[i]) {
913 key_free(options.identity_keys[i]);
914 options.identity_keys[i] = NULL;
918 exit_status = compat20 ? ssh_session2() : ssh_session();
921 if (options.control_path != NULL && muxserver_sock != -1)
922 unlink(options.control_path);
924 /* Kill ProxyCommand if it is running. */
925 ssh_kill_proxy_command();
931 control_persist_detach(void)
936 debug("%s: backgrounding master process", __func__);
939 * master (current process) into the background, and make the
940 * foreground process a client of the backgrounded master.
942 switch ((pid = fork())) {
944 fatal("%s: fork: %s", __func__, strerror(errno));
946 /* Child: master process continues mainloop */
949 /* Parent: set up mux slave to connect to backgrounded master */
950 debug2("%s: background process is %ld", __func__, (long)pid);
951 stdin_null_flag = ostdin_null_flag;
952 no_shell_flag = ono_shell_flag;
953 no_tty_flag = ono_tty_flag;
954 tty_flag = otty_flag;
955 close(muxserver_sock);
957 options.control_master = SSHCTL_MASTER_NO;
958 muxclient(options.control_path);
959 /* muxclient() doesn't return on success. */
960 fatal("Failed to connect to new control master");
962 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
963 error("%s: open(\"/dev/null\"): %s", __func__,
966 if (dup2(devnull, STDIN_FILENO) == -1 ||
967 dup2(devnull, STDOUT_FILENO) == -1)
968 error("%s: dup2: %s", __func__, strerror(errno));
969 if (devnull > STDERR_FILENO)
974 /* Do fork() after authentication. Used by "ssh -f" */
978 if (need_controlpersist_detach)
979 control_persist_detach();
980 debug("forking to background");
981 fork_after_authentication_flag = 0;
982 if (daemon(1, 1) < 0)
983 fatal("daemon() failed: %.200s", strerror(errno));
986 /* Callback for remote forward global requests */
988 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
990 Forward *rfwd = (Forward *)ctxt;
992 /* XXX verbose() on failure? */
993 debug("remote forward %s for: listen %d, connect %s:%d",
994 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
995 rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
996 if (type == SSH2_MSG_REQUEST_SUCCESS && rfwd->listen_port == 0) {
997 rfwd->allocated_port = packet_get_int();
998 logit("Allocated port %u for remote forward to %s:%d",
999 rfwd->allocated_port,
1000 rfwd->connect_host, rfwd->connect_port);
1003 if (type == SSH2_MSG_REQUEST_FAILURE) {
1004 if (options.exit_on_forward_failure)
1005 fatal("Error: remote port forwarding failed for "
1006 "listen port %d", rfwd->listen_port);
1008 logit("Warning: remote port forwarding failed for "
1009 "listen port %d", rfwd->listen_port);
1011 if (++remote_forward_confirms_received == options.num_remote_forwards) {
1012 debug("All remote forwarding requests processed");
1013 if (fork_after_authentication_flag)
1019 client_cleanup_stdio_fwd(int id, void *arg)
1021 debug("stdio forwarding: done");
1026 client_setup_stdio_fwd(const char *host_to_connect, u_short port_to_connect)
1031 debug3("client_setup_stdio_fwd %s:%d", host_to_connect,
1034 in = dup(STDIN_FILENO);
1035 out = dup(STDOUT_FILENO);
1036 if (in < 0 || out < 0)
1037 fatal("channel_connect_stdio_fwd: dup() in/out failed");
1039 if ((c = channel_connect_stdio_fwd(host_to_connect, port_to_connect,
1042 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0);
1047 ssh_init_forwarding(void)
1052 if (stdio_forward_host != NULL) {
1054 fatal("stdio forwarding require Protocol 2");
1056 if (!client_setup_stdio_fwd(stdio_forward_host,
1057 stdio_forward_port))
1058 fatal("Failed to connect in stdio forward mode.");
1061 /* Initiate local TCP/IP port forwardings. */
1062 for (i = 0; i < options.num_local_forwards; i++) {
1063 debug("Local connections to %.200s:%d forwarded to remote "
1064 "address %.200s:%d",
1065 (options.local_forwards[i].listen_host == NULL) ?
1066 (options.gateway_ports ? "*" : "LOCALHOST") :
1067 options.local_forwards[i].listen_host,
1068 options.local_forwards[i].listen_port,
1069 options.local_forwards[i].connect_host,
1070 options.local_forwards[i].connect_port);
1071 success += channel_setup_local_fwd_listener(
1072 options.local_forwards[i].listen_host,
1073 options.local_forwards[i].listen_port,
1074 options.local_forwards[i].connect_host,
1075 options.local_forwards[i].connect_port,
1076 options.gateway_ports);
1078 if (i > 0 && success != i && options.exit_on_forward_failure)
1079 fatal("Could not request local forwarding.");
1080 if (i > 0 && success == 0)
1081 error("Could not request local forwarding.");
1083 /* Initiate remote TCP/IP port forwardings. */
1084 for (i = 0; i < options.num_remote_forwards; i++) {
1085 debug("Remote connections from %.200s:%d forwarded to "
1086 "local address %.200s:%d",
1087 (options.remote_forwards[i].listen_host == NULL) ?
1088 "LOCALHOST" : options.remote_forwards[i].listen_host,
1089 options.remote_forwards[i].listen_port,
1090 options.remote_forwards[i].connect_host,
1091 options.remote_forwards[i].connect_port);
1092 if (channel_request_remote_forwarding(
1093 options.remote_forwards[i].listen_host,
1094 options.remote_forwards[i].listen_port,
1095 options.remote_forwards[i].connect_host,
1096 options.remote_forwards[i].connect_port) < 0) {
1097 if (options.exit_on_forward_failure)
1098 fatal("Could not request remote forwarding.");
1100 logit("Warning: Could not request remote "
1103 client_register_global_confirm(ssh_confirm_remote_forward,
1104 &options.remote_forwards[i]);
1107 /* Initiate tunnel forwarding. */
1108 if (options.tun_open != SSH_TUNMODE_NO) {
1109 if (client_request_tun_fwd(options.tun_open,
1110 options.tun_local, options.tun_remote) == -1) {
1111 if (options.exit_on_forward_failure)
1112 fatal("Could not request tunnel forwarding.");
1114 error("Could not request tunnel forwarding.");
1120 check_agent_present(void)
1122 if (options.forward_agent) {
1123 /* Clear agent forwarding if we don't have an agent. */
1124 if (!ssh_agent_present())
1125 options.forward_agent = 0;
1133 int interactive = 0;
1137 const char *display;
1139 /* Enable compression if requested. */
1140 if (options.compression) {
1141 debug("Requesting compression at level %d.",
1142 options.compression_level);
1144 if (options.compression_level < 1 ||
1145 options.compression_level > 9)
1146 fatal("Compression level must be from 1 (fast) to "
1149 /* Send the request. */
1150 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
1151 packet_put_int(options.compression_level);
1153 packet_write_wait();
1154 type = packet_read();
1155 if (type == SSH_SMSG_SUCCESS)
1156 packet_start_compression(options.compression_level);
1157 else if (type == SSH_SMSG_FAILURE)
1158 logit("Warning: Remote host refused compression.");
1160 packet_disconnect("Protocol error waiting for "
1161 "compression response.");
1163 /* Allocate a pseudo tty if appropriate. */
1165 debug("Requesting pty.");
1167 /* Start the packet. */
1168 packet_start(SSH_CMSG_REQUEST_PTY);
1170 /* Store TERM in the packet. There is no limit on the
1171 length of the string. */
1172 cp = getenv("TERM");
1175 packet_put_cstring(cp);
1177 /* Store window size in the packet. */
1178 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
1179 memset(&ws, 0, sizeof(ws));
1180 packet_put_int((u_int)ws.ws_row);
1181 packet_put_int((u_int)ws.ws_col);
1182 packet_put_int((u_int)ws.ws_xpixel);
1183 packet_put_int((u_int)ws.ws_ypixel);
1185 /* Store tty modes in the packet. */
1186 tty_make_modes(fileno(stdin), NULL);
1188 /* Send the packet, and wait for it to leave. */
1190 packet_write_wait();
1192 /* Read response from the server. */
1193 type = packet_read();
1194 if (type == SSH_SMSG_SUCCESS) {
1197 } else if (type == SSH_SMSG_FAILURE)
1198 logit("Warning: Remote host failed or refused to "
1199 "allocate a pseudo tty.");
1201 packet_disconnect("Protocol error waiting for pty "
1202 "request response.");
1204 /* Request X11 forwarding if enabled and DISPLAY is set. */
1205 display = getenv("DISPLAY");
1206 if (options.forward_x11 && display != NULL) {
1208 /* Get reasonable local authentication information. */
1209 client_x11_get_proto(display, options.xauth_location,
1210 options.forward_x11_trusted,
1211 options.forward_x11_timeout,
1213 /* Request forwarding with authentication spoofing. */
1214 debug("Requesting X11 forwarding with authentication "
1216 x11_request_forwarding_with_spoofing(0, display, proto, data);
1218 /* Read response from the server. */
1219 type = packet_read();
1220 if (type == SSH_SMSG_SUCCESS) {
1222 } else if (type == SSH_SMSG_FAILURE) {
1223 logit("Warning: Remote host denied X11 forwarding.");
1225 packet_disconnect("Protocol error waiting for X11 "
1229 /* Tell the packet module whether this is an interactive session. */
1230 packet_set_interactive(interactive,
1231 options.ip_qos_interactive, options.ip_qos_bulk);
1233 /* Request authentication agent forwarding if appropriate. */
1234 check_agent_present();
1236 if (options.forward_agent) {
1237 debug("Requesting authentication agent forwarding.");
1238 auth_request_forwarding();
1240 /* Read response from the server. */
1241 type = packet_read();
1243 if (type != SSH_SMSG_SUCCESS)
1244 logit("Warning: Remote host denied authentication agent forwarding.");
1247 /* Initiate port forwardings. */
1248 ssh_init_forwarding();
1250 /* Execute a local command */
1251 if (options.local_command != NULL &&
1252 options.permit_local_command)
1253 ssh_local_cmd(options.local_command);
1256 * If requested and we are not interested in replies to remote
1257 * forwarding requests, then let ssh continue in the background.
1259 if (fork_after_authentication_flag) {
1260 if (options.exit_on_forward_failure &&
1261 options.num_remote_forwards > 0) {
1262 debug("deferring postauth fork until remote forward "
1263 "confirmation received");
1269 * If a command was specified on the command line, execute the
1270 * command now. Otherwise request the server to start a shell.
1272 if (buffer_len(&command) > 0) {
1273 int len = buffer_len(&command);
1276 debug("Sending command: %.*s", len,
1277 (u_char *)buffer_ptr(&command));
1278 packet_start(SSH_CMSG_EXEC_CMD);
1279 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1281 packet_write_wait();
1283 debug("Requesting shell.");
1284 packet_start(SSH_CMSG_EXEC_SHELL);
1286 packet_write_wait();
1289 /* Enter the interactive session. */
1290 return client_loop(have_tty, tty_flag ?
1291 options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1294 /* request pty/x11/agent/tcpfwd/shell for channel */
1296 ssh_session2_setup(int id, int success, void *arg)
1298 extern char **environ;
1299 const char *display;
1300 int interactive = tty_flag;
1303 return; /* No need for error message, channels code sens one */
1305 display = getenv("DISPLAY");
1306 if (options.forward_x11 && display != NULL) {
1308 /* Get reasonable local authentication information. */
1309 client_x11_get_proto(display, options.xauth_location,
1310 options.forward_x11_trusted,
1311 options.forward_x11_timeout, &proto, &data);
1312 /* Request forwarding with authentication spoofing. */
1313 debug("Requesting X11 forwarding with authentication "
1315 x11_request_forwarding_with_spoofing(id, display, proto, data);
1317 /* XXX wait for reply */
1320 check_agent_present();
1321 if (options.forward_agent) {
1322 debug("Requesting authentication agent forwarding.");
1323 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1327 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1328 NULL, fileno(stdin), &command, environ);
1331 /* open new channel for a session */
1333 ssh_session2_open(void)
1336 int window, packetmax, in, out, err;
1339 int socksizelen = sizeof(int);
1341 if (stdin_null_flag) {
1342 in = open(_PATH_DEVNULL, O_RDONLY);
1344 in = dup(STDIN_FILENO);
1346 out = dup(STDOUT_FILENO);
1347 err = dup(STDERR_FILENO);
1349 if (in < 0 || out < 0 || err < 0)
1350 fatal("dup() in/out/err failed");
1352 /* enable nonblocking unless tty */
1360 /* we need to check to see if what they want to do about buffer */
1361 /* sizes here. In a hpn to nonhpn connection we want to limit */
1362 /* the window size to something reasonable in case the far side */
1363 /* has the large window bug. In hpn to hpn connection we want to */
1364 /* use the max window size but allow the user to override it */
1365 /* lastly if they disabled hpn then use the ssh std window size */
1367 /* so why don't we just do a getsockopt() here and set the */
1368 /* ssh window to that? In the case of a autotuning receive */
1369 /* window the window would get stuck at the initial buffer */
1370 /* size generally less than 96k. Therefore we need to set the */
1371 /* maximum ssh window size to the maximum hpn buffer size */
1372 /* unless the user has specifically set the tcprcvbufpoll */
1373 /* to no. In which case we *can* just set the window to the */
1374 /* minimum of the hpn buffer size and tcp receive buffer size */
1377 options.hpn_buffer_size = CHAN_SES_WINDOW_DEFAULT;
1379 options.hpn_buffer_size = 2*1024*1024;
1381 if (datafellows & SSH_BUG_LARGEWINDOW)
1383 debug("HPN to Non-HPN Connection");
1387 if (options.tcp_rcv_buf_poll <= 0)
1389 sock = socket(AF_INET, SOCK_STREAM, 0);
1390 getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1391 &socksize, &socksizelen);
1393 debug("socksize %d", socksize);
1394 options.hpn_buffer_size = socksize;
1395 debug ("HPNBufferSize set to TCP RWIN: %d", options.hpn_buffer_size);
1399 if (options.tcp_rcv_buf > 0)
1401 /*create a socket but don't connect it */
1402 /* we use that the get the rcv socket size */
1403 sock = socket(AF_INET, SOCK_STREAM, 0);
1404 /* if they are using the tcp_rcv_buf option */
1405 /* attempt to set the buffer size to that */
1406 if (options.tcp_rcv_buf)
1407 setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void *)&options.tcp_rcv_buf,
1408 sizeof(options.tcp_rcv_buf));
1409 getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1410 &socksize, &socksizelen);
1412 debug("socksize %d", socksize);
1413 options.hpn_buffer_size = socksize;
1414 debug ("HPNBufferSize set to user TCPRcvBuf: %d", options.hpn_buffer_size);
1420 debug("Final hpn_buffer_size = %d", options.hpn_buffer_size);
1422 window = options.hpn_buffer_size;
1424 channel_set_hpn(options.hpn_disabled, options.hpn_buffer_size);
1426 packetmax = CHAN_SES_PACKET_DEFAULT;
1428 window = 4*CHAN_SES_PACKET_DEFAULT;
1433 "session", SSH_CHANNEL_OPENING, in, out, err,
1434 window, packetmax, CHAN_EXTENDED_WRITE,
1435 "client-session", /*nonblock*/0);
1436 if ((options.tcp_rcv_buf_poll > 0) && (!options.hpn_disabled)) {
1437 c->dynamic_window = 1;
1438 debug ("Enabled Dynamic Window Scaling\n");
1440 debug3("ssh_session2_open: channel_new: %d", c->self);
1442 channel_send_open(c->self);
1444 channel_register_open_confirm(c->self,
1445 ssh_session2_setup, NULL);
1455 /* XXX should be pre-session */
1456 ssh_init_forwarding();
1458 /* Start listening for multiplex clients */
1462 * If we are in control persist mode, then prepare to background
1463 * ourselves and have a foreground client attach as a control
1464 * slave. NB. we must save copies of the flags that we override for
1465 * the backgrounding, since we defer attachment of the slave until
1466 * after the connection is fully established (in particular,
1467 * async rfwd replies have been received for ExitOnForwardFailure).
1469 if (options.control_persist && muxserver_sock != -1) {
1470 ostdin_null_flag = stdin_null_flag;
1471 ono_shell_flag = no_shell_flag;
1472 ono_tty_flag = no_tty_flag;
1473 otty_flag = tty_flag;
1474 stdin_null_flag = 1;
1478 if (!fork_after_authentication_flag)
1479 need_controlpersist_detach = 1;
1480 fork_after_authentication_flag = 1;
1483 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1484 id = ssh_session2_open();
1486 /* If we don't expect to open a new session, then disallow it */
1487 if (options.control_master == SSHCTL_MASTER_NO &&
1488 (datafellows & SSH_NEW_OPENSSH)) {
1489 debug("Requesting no-more-sessions@openssh.com");
1490 packet_start(SSH2_MSG_GLOBAL_REQUEST);
1491 packet_put_cstring("no-more-sessions@openssh.com");
1496 /* Execute a local command */
1497 if (options.local_command != NULL &&
1498 options.permit_local_command)
1499 ssh_local_cmd(options.local_command);
1502 * If requested and we are not interested in replies to remote
1503 * forwarding requests, then let ssh continue in the background.
1505 if (fork_after_authentication_flag) {
1506 if (options.exit_on_forward_failure &&
1507 options.num_remote_forwards > 0) {
1508 debug("deferring postauth fork until remote forward "
1509 "confirmation received");
1514 if (options.use_roaming)
1517 return client_loop(tty_flag, tty_flag ?
1518 options.escape_char : SSH_ESCAPECHAR_NONE, id);
1522 load_public_identity_files(void)
1524 char *filename, *cp, thishost[NI_MAXHOST];
1525 char *pwdir = NULL, *pwname = NULL;
1530 char *identity_files[SSH_MAX_IDENTITY_FILES];
1531 Key *identity_keys[SSH_MAX_IDENTITY_FILES];
1532 #ifdef ENABLE_PKCS11
1538 bzero(identity_files, sizeof(identity_files));
1539 bzero(identity_keys, sizeof(identity_keys));
1541 #ifdef ENABLE_PKCS11
1542 if (options.pkcs11_provider != NULL &&
1543 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1544 (pkcs11_init(!options.batch_mode) == 0) &&
1545 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL,
1547 for (i = 0; i < nkeys; i++) {
1548 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
1552 identity_keys[n_ids] = keys[i];
1553 identity_files[n_ids] =
1554 xstrdup(options.pkcs11_provider); /* XXX */
1559 #endif /* ENABLE_PKCS11 */
1560 if ((pw = getpwuid(original_real_uid)) == NULL)
1561 fatal("load_public_identity_files: getpwuid failed");
1562 pwname = xstrdup(pw->pw_name);
1563 pwdir = xstrdup(pw->pw_dir);
1564 if (gethostname(thishost, sizeof(thishost)) == -1)
1565 fatal("load_public_identity_files: gethostname: %s",
1567 for (i = 0; i < options.num_identity_files; i++) {
1568 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
1569 xfree(options.identity_files[i]);
1572 cp = tilde_expand_filename(options.identity_files[i],
1574 filename = percent_expand(cp, "d", pwdir,
1575 "u", pwname, "l", thishost, "h", host,
1576 "r", options.user, (char *)NULL);
1578 public = key_load_public(filename, NULL);
1579 debug("identity file %s type %d", filename,
1580 public ? public->type : -1);
1581 xfree(options.identity_files[i]);
1582 identity_files[n_ids] = filename;
1583 identity_keys[n_ids] = public;
1585 if (++n_ids >= SSH_MAX_IDENTITY_FILES)
1588 /* Try to add the certificate variant too */
1589 xasprintf(&cp, "%s-cert", filename);
1590 public = key_load_public(cp, NULL);
1591 debug("identity file %s type %d", cp,
1592 public ? public->type : -1);
1593 if (public == NULL) {
1597 if (!key_is_cert(public)) {
1598 debug("%s: key %s type %s is not a certificate",
1599 __func__, cp, key_type(public));
1604 identity_keys[n_ids] = public;
1605 /* point to the original path, most likely the private key */
1606 identity_files[n_ids] = xstrdup(filename);
1609 options.num_identity_files = n_ids;
1610 memcpy(options.identity_files, identity_files, sizeof(identity_files));
1611 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys));
1613 bzero(pwname, strlen(pwname));
1615 bzero(pwdir, strlen(pwdir));
1620 main_sigchld_handler(int sig)
1622 int save_errno = errno;
1626 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
1627 (pid < 0 && errno == EINTR))
1630 signal(sig, main_sigchld_handler);