1 /* $OpenBSD: ssh.c,v 1.346 2010/08/12 21:49:44 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>
70 #include <netinet/in.h>
71 #include <arpa/inet.h>
73 #include <openssl/evp.h>
74 #include <openssl/err.h>
75 #include "openbsd-compat/openssl-compat.h"
76 #include "openbsd-compat/sys-queue.h"
91 #include "pathnames.h"
93 #include "clientloop.h"
96 #include "sshconnect.h"
108 #include "ssh-pkcs11.h"
111 extern char *__progname;
113 /* Flag indicating whether debug mode is on. May be set on the command line. */
116 /* Flag indicating whether a tty should be allocated */
119 int force_tty_flag = 0;
121 /* don't exec a shell */
122 int no_shell_flag = 0;
125 * Flag indicating that nothing should be read from stdin. This can be set
126 * on the command line.
128 int stdin_null_flag = 0;
131 * Flag indicating that the current process should be backgrounded and
132 * a new slave launched in the foreground for ControlPersist.
134 int need_controlpersist_detach = 0;
136 /* Copies of flags for ControlPersist foreground slave */
137 int ostdin_null_flag, ono_shell_flag, ono_tty_flag, otty_flag;
140 * Flag indicating that ssh should fork after authentication. This is useful
141 * so that the passphrase can be entered manually, and then ssh goes to the
144 int fork_after_authentication_flag = 0;
146 /* forward stdio to remote host and port */
147 char *stdio_forward_host = NULL;
148 int stdio_forward_port = 0;
151 * General data structure for command line options and options configurable
152 * in configuration files. See readconf.h.
156 /* optional user configfile */
160 * Name of the host we are connecting to. This is the name given on the
161 * command line, or the HostName specified for the user-supplied name in a
162 * configuration file.
166 /* socket address the host resolves to */
167 struct sockaddr_storage hostaddr;
169 /* Private host keys. */
170 Sensitive sensitive_data;
172 /* Original real UID. */
173 uid_t original_real_uid;
174 uid_t original_effective_uid;
176 /* command to be executed */
179 /* Should we execute a command or invoke a subsystem? */
180 int subsystem_flag = 0;
182 /* # of replies received for global requests */
183 static int remote_forward_confirms_received = 0;
185 /* pid of proxycommand child process */
186 pid_t proxy_command_pid = 0;
189 extern int muxserver_sock;
190 extern u_int muxclient_command;
192 /* Prints a help message to the user. This function never returns. */
198 "usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n"
199 " [-D [bind_address:]port] [-e escape_char] [-F configfile]\n"
200 " [-I pkcs11] [-i identity_file]\n"
201 " [-L [bind_address:]port:host:hostport]\n"
202 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
203 " [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
204 " [-W host:port] [-w local_tun[:remote_tun]]\n"
205 " [user@]hostname [command]\n"
210 static int ssh_session(void);
211 static int ssh_session2(void);
212 static void load_public_identity_files(void);
214 /* from muxclient.c */
215 void muxclient(const char *);
216 void muxserver_listen(void);
219 * Main program for the ssh client.
222 main(int ac, char **av)
224 int i, r, opt, exit_status, use_syslog;
225 char *p, *cp, *line, *argv0, buf[MAXPATHLEN];
228 int dummy, timeout_ms;
229 extern int optind, optreset;
234 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
237 __progname = ssh_get_progname(av[0]);
241 * Discard other fds that are hanging around. These can cause problem
242 * with backgrounded ssh processes started by ControlPersist.
244 closefrom(STDERR_FILENO + 1);
247 * Save the original real uid. It will be needed later (uid-swapping
248 * may clobber the real uid).
250 original_real_uid = getuid();
251 original_effective_uid = geteuid();
254 * Use uid-swapping to give up root privileges for the duration of
255 * option processing. We will re-instantiate the rights when we are
256 * ready to create the privileged port, and will permanently drop
257 * them when the port has been created (actually, when the connection
258 * has been made, as we may need to create the port several times).
262 #ifdef HAVE_SETRLIMIT
263 /* If we are installed setuid root be careful to not drop core. */
264 if (original_real_uid != original_effective_uid) {
266 rlim.rlim_cur = rlim.rlim_max = 0;
267 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
268 fatal("setrlimit failed: %.100s", strerror(errno));
272 pw = getpwuid(original_real_uid);
274 logit("You don't exist, go away!");
277 /* Take a copy of the returned structure. */
281 * Set our umask to something reasonable, as some files are created
282 * with the default umask. This will make them world-readable but
283 * writable only by the owner, which is ok for all files for which we
284 * don't set the modes explicitly.
289 * Initialize option structure to indicate that no values have been
292 initialize_options(&options);
294 /* Parse command-line arguments. */
300 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
301 "ACD:F:I:KL:MNO:PR:S:TVw:W:XYy")) != -1) {
304 options.protocol = SSH_PROTO_1;
307 options.protocol = SSH_PROTO_2;
310 options.address_family = AF_INET;
313 options.address_family = AF_INET6;
319 fork_after_authentication_flag = 1;
323 options.forward_x11 = 0;
326 options.forward_x11 = 1;
332 options.forward_x11 = 1;
333 options.forward_x11_trusted = 1;
336 options.gateway_ports = 1;
339 if (stdio_forward_host != NULL)
340 fatal("Cannot specify multiplexing "
342 else if (muxclient_command != 0)
343 fatal("Multiplexing command already specified");
344 if (strcmp(optarg, "check") == 0)
345 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
346 else if (strcmp(optarg, "forward") == 0)
347 muxclient_command = SSHMUX_COMMAND_FORWARD;
348 else if (strcmp(optarg, "exit") == 0)
349 muxclient_command = SSHMUX_COMMAND_TERMINATE;
351 fatal("Invalid multiplex command.");
353 case 'P': /* deprecated */
354 options.use_privileged_port = 0;
357 options.forward_agent = 0;
360 options.forward_agent = 1;
363 options.gss_deleg_creds = 0;
366 options.gss_authentication = 1;
367 options.gss_deleg_creds = 1;
370 if (stat(optarg, &st) < 0) {
371 fprintf(stderr, "Warning: Identity file %s "
372 "not accessible: %s.\n", optarg,
376 if (options.num_identity_files >=
377 SSH_MAX_IDENTITY_FILES)
378 fatal("Too many identity files specified "
379 "(max %d)", SSH_MAX_IDENTITY_FILES);
380 options.identity_files[options.num_identity_files++] =
385 options.pkcs11_provider = xstrdup(optarg);
387 fprintf(stderr, "no support for PKCS#11.\n");
396 if (debug_flag == 0) {
398 options.log_level = SYSLOG_LEVEL_DEBUG1;
400 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
406 fprintf(stderr, "%s, %s\n",
407 SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
412 if (options.tun_open == -1)
413 options.tun_open = SSH_TUNMODE_DEFAULT;
414 options.tun_local = a2tun(optarg, &options.tun_remote);
415 if (options.tun_local == SSH_TUNID_ERR) {
417 "Bad tun device '%s'\n", optarg);
422 if (stdio_forward_host != NULL)
423 fatal("stdio forward already specified");
424 if (muxclient_command != 0)
425 fatal("Cannot specify stdio forward with -O");
426 if (parse_forward(&fwd, optarg, 1, 0)) {
427 stdio_forward_host = fwd.listen_host;
428 stdio_forward_port = fwd.listen_port;
429 xfree(fwd.connect_host);
432 "Bad stdio forwarding specification '%s'\n",
438 options.clear_forwardings = 1;
439 options.exit_on_forward_failure = 1;
442 options.log_level = SYSLOG_LEVEL_QUIET;
445 if (optarg[0] == '^' && optarg[2] == 0 &&
446 (u_char) optarg[1] >= 64 &&
447 (u_char) optarg[1] < 128)
448 options.escape_char = (u_char) optarg[1] & 31;
449 else if (strlen(optarg) == 1)
450 options.escape_char = (u_char) optarg[0];
451 else if (strcmp(optarg, "none") == 0)
452 options.escape_char = SSH_ESCAPECHAR_NONE;
454 fprintf(stderr, "Bad escape character '%s'.\n",
460 if (ciphers_valid(optarg)) {
462 options.ciphers = xstrdup(optarg);
463 options.cipher = SSH_CIPHER_INVALID;
466 options.cipher = cipher_number(optarg);
467 if (options.cipher == -1) {
469 "Unknown cipher type '%s'\n",
473 if (options.cipher == SSH_CIPHER_3DES)
474 options.ciphers = "3des-cbc";
475 else if (options.cipher == SSH_CIPHER_BLOWFISH)
476 options.ciphers = "blowfish-cbc";
478 options.ciphers = (char *)-1;
482 if (mac_valid(optarg))
483 options.macs = xstrdup(optarg);
485 fprintf(stderr, "Unknown mac type '%s'\n",
491 if (options.control_master == SSHCTL_MASTER_YES)
492 options.control_master = SSHCTL_MASTER_ASK;
494 options.control_master = SSHCTL_MASTER_YES;
497 options.port = a2port(optarg);
498 if (options.port <= 0) {
499 fprintf(stderr, "Bad port '%s'\n", optarg);
504 options.user = optarg;
508 if (parse_forward(&fwd, optarg, 0, 0))
509 add_local_forward(&options, &fwd);
512 "Bad local forwarding specification '%s'\n",
519 if (parse_forward(&fwd, optarg, 0, 1)) {
520 add_remote_forward(&options, &fwd);
523 "Bad remote forwarding specification "
530 if (parse_forward(&fwd, optarg, 1, 0)) {
531 add_local_forward(&options, &fwd);
534 "Bad dynamic forwarding specification "
541 options.compression = 1;
552 line = xstrdup(optarg);
553 if (process_config_line(&options, host ? host : "",
554 line, "command-line", 0, &dummy) != 0)
562 if (options.control_path != NULL)
563 free(options.control_path);
564 options.control_path = xstrdup(optarg);
567 options.bind_address = optarg;
580 if (ac > 0 && !host) {
581 if (strrchr(*av, '@')) {
583 cp = strrchr(p, '@');
584 if (cp == NULL || cp == p)
592 optind = optreset = 1;
598 /* Check that we got a host name. */
602 SSLeay_add_all_algorithms();
603 ERR_load_crypto_strings();
605 /* Initialize the command to execute on remote host. */
606 buffer_init(&command);
609 * Save the command to execute on the remote host in a buffer. There
610 * is no limit on the length of the command, except by the maximum
611 * packet size. Also sets the tty flag if there is no command.
614 /* No command specified - execute shell on a tty. */
616 if (subsystem_flag) {
618 "You must specify a subsystem to invoke.\n");
622 /* A command has been specified. Store it into the buffer. */
623 for (i = 0; i < ac; i++) {
625 buffer_append(&command, " ", 1);
626 buffer_append(&command, av[i], strlen(av[i]));
630 /* Cannot fork to background if no command. */
631 if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
633 fatal("Cannot fork into background without a command "
636 /* Allocate a tty by default if no command specified. */
637 if (buffer_len(&command) == 0)
641 if (no_tty_flag || muxclient_command != 0)
643 /* Do not allocate a tty if stdin is not a tty. */
644 if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
646 logit("Pseudo-terminal will not be allocated because "
647 "stdin is not a terminal.");
652 * Initialize "log" output. Since we are the client all output
653 * actually goes to stderr.
656 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
657 SYSLOG_FACILITY_USER, !use_syslog);
660 * Read per-user configuration file. Ignore the system wide config
661 * file if the user specifies a config file on the command line.
663 if (config != NULL) {
664 if (!read_config_file(config, host, &options, 0))
665 fatal("Can't open user config file %.100s: "
666 "%.100s", config, strerror(errno));
668 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
669 _PATH_SSH_USER_CONFFILE);
670 if (r > 0 && (size_t)r < sizeof(buf))
671 (void)read_config_file(buf, host, &options, 1);
673 /* Read systemwide configuration file after use config. */
674 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
678 /* Fill configuration defaults. */
679 fill_default_options(&options);
681 channel_set_af(options.address_family);
684 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
688 if (options.user == NULL)
689 options.user = xstrdup(pw->pw_name);
691 /* Get default port if port has not been set. */
692 if (options.port == 0) {
693 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
694 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
697 if (options.hostname != NULL) {
698 host = percent_expand(options.hostname,
699 "h", host, (char *)NULL);
702 if (options.local_command != NULL) {
703 char thishost[NI_MAXHOST];
705 if (gethostname(thishost, sizeof(thishost)) == -1)
706 fatal("gethostname: %s", strerror(errno));
707 snprintf(buf, sizeof(buf), "%d", options.port);
708 debug3("expanding LocalCommand: %s", options.local_command);
709 cp = options.local_command;
710 options.local_command = percent_expand(cp, "d", pw->pw_dir,
711 "h", host, "l", thishost, "n", host, "r", options.user,
712 "p", buf, "u", pw->pw_name, (char *)NULL);
713 debug3("expanded LocalCommand: %s", options.local_command);
717 /* force lowercase for hostkey matching */
718 if (options.host_key_alias != NULL) {
719 for (p = options.host_key_alias; *p; p++)
721 *p = (char)tolower(*p);
724 if (options.proxy_command != NULL &&
725 strcmp(options.proxy_command, "none") == 0) {
726 xfree(options.proxy_command);
727 options.proxy_command = NULL;
729 if (options.control_path != NULL &&
730 strcmp(options.control_path, "none") == 0) {
731 xfree(options.control_path);
732 options.control_path = NULL;
735 if (options.control_path != NULL) {
736 char thishost[NI_MAXHOST];
738 if (gethostname(thishost, sizeof(thishost)) == -1)
739 fatal("gethostname: %s", strerror(errno));
740 snprintf(buf, sizeof(buf), "%d", options.port);
741 cp = tilde_expand_filename(options.control_path,
743 xfree(options.control_path);
744 options.control_path = percent_expand(cp, "p", buf, "h", host,
745 "r", options.user, "l", thishost, (char *)NULL);
748 if (muxclient_command != 0 && options.control_path == NULL)
749 fatal("No ControlPath specified for \"-O\" command");
750 if (options.control_path != NULL)
751 muxclient(options.control_path);
753 timeout_ms = options.connection_timeout * 1000;
755 /* Open a connection to the remote host. */
756 if (ssh_connect(host, &hostaddr, options.port,
757 options.address_family, options.connection_attempts, &timeout_ms,
758 options.tcp_keep_alive,
760 options.use_privileged_port,
762 original_effective_uid == 0 && options.use_privileged_port,
764 options.proxy_command) != 0)
768 debug3("timeout: %d ms remain after connect", timeout_ms);
771 * If we successfully made the connection, load the host private key
772 * in case we will need it later for combined rsa-rhosts
773 * authentication. This must be done before releasing extra
774 * privileges, because the file is only readable by root.
775 * If we cannot access the private keys, load the public keys
776 * instead and try to execute the ssh-keysign helper instead.
778 sensitive_data.nkeys = 0;
779 sensitive_data.keys = NULL;
780 sensitive_data.external_keysign = 0;
781 if (options.rhosts_rsa_authentication ||
782 options.hostbased_authentication) {
783 sensitive_data.nkeys = 5;
784 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
788 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
789 _PATH_HOST_KEY_FILE, "", NULL, NULL);
790 sensitive_data.keys[1] = key_load_private_cert(KEY_DSA,
791 _PATH_HOST_DSA_KEY_FILE, "", NULL);
792 sensitive_data.keys[2] = key_load_private_cert(KEY_RSA,
793 _PATH_HOST_RSA_KEY_FILE, "", NULL);
794 sensitive_data.keys[3] = key_load_private_type(KEY_DSA,
795 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
796 sensitive_data.keys[4] = key_load_private_type(KEY_RSA,
797 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
800 if (options.hostbased_authentication == 1 &&
801 sensitive_data.keys[0] == NULL &&
802 sensitive_data.keys[3] == NULL &&
803 sensitive_data.keys[4] == NULL) {
804 sensitive_data.keys[1] = key_load_cert(
805 _PATH_HOST_DSA_KEY_FILE);
806 sensitive_data.keys[2] = key_load_cert(
807 _PATH_HOST_RSA_KEY_FILE);
808 sensitive_data.keys[3] = key_load_public(
809 _PATH_HOST_DSA_KEY_FILE, NULL);
810 sensitive_data.keys[4] = key_load_public(
811 _PATH_HOST_RSA_KEY_FILE, NULL);
812 sensitive_data.external_keysign = 1;
816 * Get rid of any extra privileges that we may have. We will no
817 * longer need them. Also, extra privileges could make it very hard
818 * to read identity files and other non-world-readable files from the
819 * user's home directory if it happens to be on a NFS volume where
820 * root is mapped to nobody.
822 if (original_effective_uid == 0) {
824 permanently_set_uid(pw);
828 * Now that we are back to our own permissions, create ~/.ssh
829 * directory if it doesn't already exist.
831 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir,
832 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
833 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0)
834 if (mkdir(buf, 0700) < 0)
835 error("Could not create directory '%.200s'.", buf);
837 /* load options.identity_files */
838 load_public_identity_files();
840 /* Expand ~ in known host file names. */
842 options.system_hostfile =
843 tilde_expand_filename(options.system_hostfile, original_real_uid);
844 options.user_hostfile =
845 tilde_expand_filename(options.user_hostfile, original_real_uid);
846 options.system_hostfile2 =
847 tilde_expand_filename(options.system_hostfile2, original_real_uid);
848 options.user_hostfile2 =
849 tilde_expand_filename(options.user_hostfile2, original_real_uid);
851 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
853 /* Log into the remote system. Never returns if the login fails. */
854 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
857 if (packet_connection_is_on_socket()) {
858 verbose("Authenticated to %s ([%s]:%d).", host,
859 get_remote_ipaddr(), get_remote_port());
861 verbose("Authenticated to %s (via proxy).", host);
864 /* We no longer need the private host keys. Clear them now. */
865 if (sensitive_data.nkeys != 0) {
866 for (i = 0; i < sensitive_data.nkeys; i++) {
867 if (sensitive_data.keys[i] != NULL) {
868 /* Destroys contents safely */
869 debug3("clear hostkey %d", i);
870 key_free(sensitive_data.keys[i]);
871 sensitive_data.keys[i] = NULL;
874 xfree(sensitive_data.keys);
876 for (i = 0; i < options.num_identity_files; i++) {
877 if (options.identity_files[i]) {
878 xfree(options.identity_files[i]);
879 options.identity_files[i] = NULL;
881 if (options.identity_keys[i]) {
882 key_free(options.identity_keys[i]);
883 options.identity_keys[i] = NULL;
887 exit_status = compat20 ? ssh_session2() : ssh_session();
890 if (options.control_path != NULL && muxserver_sock != -1)
891 unlink(options.control_path);
894 * Send SIGHUP to proxy command if used. We don't wait() in
895 * case it hangs and instead rely on init to reap the child
897 if (proxy_command_pid > 1)
898 kill(proxy_command_pid, SIGHUP);
904 control_persist_detach(void)
909 debug("%s: backgrounding master process", __func__);
912 * master (current process) into the background, and make the
913 * foreground process a client of the backgrounded master.
915 switch ((pid = fork())) {
917 fatal("%s: fork: %s", __func__, strerror(errno));
919 /* Child: master process continues mainloop */
922 /* Parent: set up mux slave to connect to backgrounded master */
923 debug2("%s: background process is %ld", __func__, (long)pid);
924 stdin_null_flag = ostdin_null_flag;
925 no_shell_flag = ono_shell_flag;
926 no_tty_flag = ono_tty_flag;
927 tty_flag = otty_flag;
928 close(muxserver_sock);
930 muxclient(options.control_path);
931 /* muxclient() doesn't return on success. */
932 fatal("Failed to connect to new control master");
934 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
935 error("%s: open(\"/dev/null\"): %s", __func__,
938 if (dup2(devnull, STDIN_FILENO) == -1 ||
939 dup2(devnull, STDOUT_FILENO) == -1)
940 error("%s: dup2: %s", __func__, strerror(errno));
941 if (devnull > STDERR_FILENO)
946 /* Do fork() after authentication. Used by "ssh -f" */
950 if (need_controlpersist_detach)
951 control_persist_detach();
952 debug("forking to background");
953 fork_after_authentication_flag = 0;
954 if (daemon(1, 1) < 0)
955 fatal("daemon() failed: %.200s", strerror(errno));
958 /* Callback for remote forward global requests */
960 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
962 Forward *rfwd = (Forward *)ctxt;
964 /* XXX verbose() on failure? */
965 debug("remote forward %s for: listen %d, connect %s:%d",
966 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
967 rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
968 if (type == SSH2_MSG_REQUEST_SUCCESS && rfwd->listen_port == 0) {
969 rfwd->allocated_port = packet_get_int();
970 logit("Allocated port %u for remote forward to %s:%d",
971 rfwd->allocated_port,
972 rfwd->connect_host, rfwd->connect_port);
975 if (type == SSH2_MSG_REQUEST_FAILURE) {
976 if (options.exit_on_forward_failure)
977 fatal("Error: remote port forwarding failed for "
978 "listen port %d", rfwd->listen_port);
980 logit("Warning: remote port forwarding failed for "
981 "listen port %d", rfwd->listen_port);
983 if (++remote_forward_confirms_received == options.num_remote_forwards) {
984 debug("All remote forwarding requests processed");
985 if (fork_after_authentication_flag)
991 client_cleanup_stdio_fwd(int id, void *arg)
993 debug("stdio forwarding: done");
998 client_setup_stdio_fwd(const char *host_to_connect, u_short port_to_connect)
1003 debug3("client_setup_stdio_fwd %s:%d", host_to_connect,
1006 in = dup(STDIN_FILENO);
1007 out = dup(STDOUT_FILENO);
1008 if (in < 0 || out < 0)
1009 fatal("channel_connect_stdio_fwd: dup() in/out failed");
1011 if ((c = channel_connect_stdio_fwd(host_to_connect, port_to_connect,
1014 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0);
1019 ssh_init_forwarding(void)
1024 if (stdio_forward_host != NULL) {
1026 fatal("stdio forwarding require Protocol 2");
1028 if (!client_setup_stdio_fwd(stdio_forward_host,
1029 stdio_forward_port))
1030 fatal("Failed to connect in stdio forward mode.");
1033 /* Initiate local TCP/IP port forwardings. */
1034 for (i = 0; i < options.num_local_forwards; i++) {
1035 debug("Local connections to %.200s:%d forwarded to remote "
1036 "address %.200s:%d",
1037 (options.local_forwards[i].listen_host == NULL) ?
1038 (options.gateway_ports ? "*" : "LOCALHOST") :
1039 options.local_forwards[i].listen_host,
1040 options.local_forwards[i].listen_port,
1041 options.local_forwards[i].connect_host,
1042 options.local_forwards[i].connect_port);
1043 success += channel_setup_local_fwd_listener(
1044 options.local_forwards[i].listen_host,
1045 options.local_forwards[i].listen_port,
1046 options.local_forwards[i].connect_host,
1047 options.local_forwards[i].connect_port,
1048 options.gateway_ports);
1050 if (i > 0 && success != i && options.exit_on_forward_failure)
1051 fatal("Could not request local forwarding.");
1052 if (i > 0 && success == 0)
1053 error("Could not request local forwarding.");
1055 /* Initiate remote TCP/IP port forwardings. */
1056 for (i = 0; i < options.num_remote_forwards; i++) {
1057 debug("Remote connections from %.200s:%d forwarded to "
1058 "local address %.200s:%d",
1059 (options.remote_forwards[i].listen_host == NULL) ?
1060 "LOCALHOST" : options.remote_forwards[i].listen_host,
1061 options.remote_forwards[i].listen_port,
1062 options.remote_forwards[i].connect_host,
1063 options.remote_forwards[i].connect_port);
1064 if (channel_request_remote_forwarding(
1065 options.remote_forwards[i].listen_host,
1066 options.remote_forwards[i].listen_port,
1067 options.remote_forwards[i].connect_host,
1068 options.remote_forwards[i].connect_port) < 0) {
1069 if (options.exit_on_forward_failure)
1070 fatal("Could not request remote forwarding.");
1072 logit("Warning: Could not request remote "
1075 client_register_global_confirm(ssh_confirm_remote_forward,
1076 &options.remote_forwards[i]);
1079 /* Initiate tunnel forwarding. */
1080 if (options.tun_open != SSH_TUNMODE_NO) {
1081 if (client_request_tun_fwd(options.tun_open,
1082 options.tun_local, options.tun_remote) == -1) {
1083 if (options.exit_on_forward_failure)
1084 fatal("Could not request tunnel forwarding.");
1086 error("Could not request tunnel forwarding.");
1092 check_agent_present(void)
1094 if (options.forward_agent) {
1095 /* Clear agent forwarding if we don't have an agent. */
1096 if (!ssh_agent_present())
1097 options.forward_agent = 0;
1105 int interactive = 0;
1109 const char *display;
1111 /* Enable compression if requested. */
1112 if (options.compression) {
1113 debug("Requesting compression at level %d.",
1114 options.compression_level);
1116 if (options.compression_level < 1 ||
1117 options.compression_level > 9)
1118 fatal("Compression level must be from 1 (fast) to "
1121 /* Send the request. */
1122 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
1123 packet_put_int(options.compression_level);
1125 packet_write_wait();
1126 type = packet_read();
1127 if (type == SSH_SMSG_SUCCESS)
1128 packet_start_compression(options.compression_level);
1129 else if (type == SSH_SMSG_FAILURE)
1130 logit("Warning: Remote host refused compression.");
1132 packet_disconnect("Protocol error waiting for "
1133 "compression response.");
1135 /* Allocate a pseudo tty if appropriate. */
1137 debug("Requesting pty.");
1139 /* Start the packet. */
1140 packet_start(SSH_CMSG_REQUEST_PTY);
1142 /* Store TERM in the packet. There is no limit on the
1143 length of the string. */
1144 cp = getenv("TERM");
1147 packet_put_cstring(cp);
1149 /* Store window size in the packet. */
1150 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
1151 memset(&ws, 0, sizeof(ws));
1152 packet_put_int((u_int)ws.ws_row);
1153 packet_put_int((u_int)ws.ws_col);
1154 packet_put_int((u_int)ws.ws_xpixel);
1155 packet_put_int((u_int)ws.ws_ypixel);
1157 /* Store tty modes in the packet. */
1158 tty_make_modes(fileno(stdin), NULL);
1160 /* Send the packet, and wait for it to leave. */
1162 packet_write_wait();
1164 /* Read response from the server. */
1165 type = packet_read();
1166 if (type == SSH_SMSG_SUCCESS) {
1169 } else if (type == SSH_SMSG_FAILURE)
1170 logit("Warning: Remote host failed or refused to "
1171 "allocate a pseudo tty.");
1173 packet_disconnect("Protocol error waiting for pty "
1174 "request response.");
1176 /* Request X11 forwarding if enabled and DISPLAY is set. */
1177 display = getenv("DISPLAY");
1178 if (options.forward_x11 && display != NULL) {
1180 /* Get reasonable local authentication information. */
1181 client_x11_get_proto(display, options.xauth_location,
1182 options.forward_x11_trusted,
1183 options.forward_x11_timeout,
1185 /* Request forwarding with authentication spoofing. */
1186 debug("Requesting X11 forwarding with authentication "
1188 x11_request_forwarding_with_spoofing(0, display, proto, data);
1190 /* Read response from the server. */
1191 type = packet_read();
1192 if (type == SSH_SMSG_SUCCESS) {
1194 } else if (type == SSH_SMSG_FAILURE) {
1195 logit("Warning: Remote host denied X11 forwarding.");
1197 packet_disconnect("Protocol error waiting for X11 "
1201 /* Tell the packet module whether this is an interactive session. */
1202 packet_set_interactive(interactive);
1204 /* Request authentication agent forwarding if appropriate. */
1205 check_agent_present();
1207 if (options.forward_agent) {
1208 debug("Requesting authentication agent forwarding.");
1209 auth_request_forwarding();
1211 /* Read response from the server. */
1212 type = packet_read();
1214 if (type != SSH_SMSG_SUCCESS)
1215 logit("Warning: Remote host denied authentication agent forwarding.");
1218 /* Initiate port forwardings. */
1219 ssh_init_forwarding();
1221 /* Execute a local command */
1222 if (options.local_command != NULL &&
1223 options.permit_local_command)
1224 ssh_local_cmd(options.local_command);
1227 * If requested and we are not interested in replies to remote
1228 * forwarding requests, then let ssh continue in the background.
1230 if (fork_after_authentication_flag) {
1231 if (options.exit_on_forward_failure &&
1232 options.num_remote_forwards > 0) {
1233 debug("deferring postauth fork until remote forward "
1234 "confirmation received");
1240 * If a command was specified on the command line, execute the
1241 * command now. Otherwise request the server to start a shell.
1243 if (buffer_len(&command) > 0) {
1244 int len = buffer_len(&command);
1247 debug("Sending command: %.*s", len,
1248 (u_char *)buffer_ptr(&command));
1249 packet_start(SSH_CMSG_EXEC_CMD);
1250 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1252 packet_write_wait();
1254 debug("Requesting shell.");
1255 packet_start(SSH_CMSG_EXEC_SHELL);
1257 packet_write_wait();
1260 /* Enter the interactive session. */
1261 return client_loop(have_tty, tty_flag ?
1262 options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1265 /* request pty/x11/agent/tcpfwd/shell for channel */
1267 ssh_session2_setup(int id, int success, void *arg)
1269 extern char **environ;
1270 const char *display;
1271 int interactive = tty_flag;
1274 return; /* No need for error message, channels code sens one */
1276 display = getenv("DISPLAY");
1277 if (options.forward_x11 && display != NULL) {
1279 /* Get reasonable local authentication information. */
1280 client_x11_get_proto(display, options.xauth_location,
1281 options.forward_x11_trusted,
1282 options.forward_x11_timeout, &proto, &data);
1283 /* Request forwarding with authentication spoofing. */
1284 debug("Requesting X11 forwarding with authentication "
1286 x11_request_forwarding_with_spoofing(id, display, proto, data);
1288 /* XXX wait for reply */
1291 check_agent_present();
1292 if (options.forward_agent) {
1293 debug("Requesting authentication agent forwarding.");
1294 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1298 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1299 NULL, fileno(stdin), &command, environ);
1301 packet_set_interactive(interactive);
1304 /* open new channel for a session */
1306 ssh_session2_open(void)
1309 int window, packetmax, in, out, err;
1311 if (stdin_null_flag) {
1312 in = open(_PATH_DEVNULL, O_RDONLY);
1314 in = dup(STDIN_FILENO);
1316 out = dup(STDOUT_FILENO);
1317 err = dup(STDERR_FILENO);
1319 if (in < 0 || out < 0 || err < 0)
1320 fatal("dup() in/out/err failed");
1322 /* enable nonblocking unless tty */
1330 window = CHAN_SES_WINDOW_DEFAULT;
1331 packetmax = CHAN_SES_PACKET_DEFAULT;
1337 "session", SSH_CHANNEL_OPENING, in, out, err,
1338 window, packetmax, CHAN_EXTENDED_WRITE,
1339 "client-session", /*nonblock*/0);
1341 debug3("ssh_session2_open: channel_new: %d", c->self);
1343 channel_send_open(c->self);
1345 channel_register_open_confirm(c->self,
1346 ssh_session2_setup, NULL);
1356 /* XXX should be pre-session */
1357 ssh_init_forwarding();
1359 /* Start listening for multiplex clients */
1363 * If we are in control persist mode, then prepare to background
1364 * ourselves and have a foreground client attach as a control
1365 * slave. NB. we must save copies of the flags that we override for
1366 * the backgrounding, since we defer attachment of the slave until
1367 * after the connection is fully established (in particular,
1368 * async rfwd replies have been received for ExitOnForwardFailure).
1370 if (options.control_persist && muxserver_sock != -1) {
1371 ostdin_null_flag = stdin_null_flag;
1372 ono_shell_flag = no_shell_flag;
1373 ono_tty_flag = no_tty_flag;
1374 otty_flag = tty_flag;
1375 stdin_null_flag = 1;
1379 if (!fork_after_authentication_flag)
1380 need_controlpersist_detach = 1;
1381 fork_after_authentication_flag = 1;
1384 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1385 id = ssh_session2_open();
1387 /* If we don't expect to open a new session, then disallow it */
1388 if (options.control_master == SSHCTL_MASTER_NO &&
1389 (datafellows & SSH_NEW_OPENSSH)) {
1390 debug("Requesting no-more-sessions@openssh.com");
1391 packet_start(SSH2_MSG_GLOBAL_REQUEST);
1392 packet_put_cstring("no-more-sessions@openssh.com");
1397 /* Execute a local command */
1398 if (options.local_command != NULL &&
1399 options.permit_local_command)
1400 ssh_local_cmd(options.local_command);
1403 * If requested and we are not interested in replies to remote
1404 * forwarding requests, then let ssh continue in the background.
1406 if (fork_after_authentication_flag) {
1407 if (options.exit_on_forward_failure &&
1408 options.num_remote_forwards > 0) {
1409 debug("deferring postauth fork until remote forward "
1410 "confirmation received");
1415 if (options.use_roaming)
1418 return client_loop(tty_flag, tty_flag ?
1419 options.escape_char : SSH_ESCAPECHAR_NONE, id);
1423 load_public_identity_files(void)
1425 char *filename, *cp, thishost[NI_MAXHOST];
1426 char *pwdir = NULL, *pwname = NULL;
1431 char *identity_files[SSH_MAX_IDENTITY_FILES];
1432 Key *identity_keys[SSH_MAX_IDENTITY_FILES];
1433 #ifdef ENABLE_PKCS11
1439 bzero(identity_files, sizeof(identity_files));
1440 bzero(identity_keys, sizeof(identity_keys));
1442 #ifdef ENABLE_PKCS11
1443 if (options.pkcs11_provider != NULL &&
1444 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1445 (pkcs11_init(!options.batch_mode) == 0) &&
1446 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL,
1448 for (i = 0; i < nkeys; i++) {
1449 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
1453 identity_keys[n_ids] = keys[i];
1454 identity_files[n_ids] =
1455 xstrdup(options.pkcs11_provider); /* XXX */
1460 #endif /* ENABLE_PKCS11 */
1461 if ((pw = getpwuid(original_real_uid)) == NULL)
1462 fatal("load_public_identity_files: getpwuid failed");
1463 pwname = xstrdup(pw->pw_name);
1464 pwdir = xstrdup(pw->pw_dir);
1465 if (gethostname(thishost, sizeof(thishost)) == -1)
1466 fatal("load_public_identity_files: gethostname: %s",
1468 for (i = 0; i < options.num_identity_files; i++) {
1469 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
1470 xfree(options.identity_files[i]);
1473 cp = tilde_expand_filename(options.identity_files[i],
1475 filename = percent_expand(cp, "d", pwdir,
1476 "u", pwname, "l", thishost, "h", host,
1477 "r", options.user, (char *)NULL);
1479 public = key_load_public(filename, NULL);
1480 debug("identity file %s type %d", filename,
1481 public ? public->type : -1);
1482 xfree(options.identity_files[i]);
1483 identity_files[n_ids] = filename;
1484 identity_keys[n_ids] = public;
1486 if (++n_ids >= SSH_MAX_IDENTITY_FILES)
1489 /* Try to add the certificate variant too */
1490 xasprintf(&cp, "%s-cert", filename);
1491 public = key_load_public(cp, NULL);
1492 debug("identity file %s type %d", cp,
1493 public ? public->type : -1);
1494 if (public == NULL) {
1498 if (!key_is_cert(public)) {
1499 debug("%s: key %s type %s is not a certificate",
1500 __func__, cp, key_type(public));
1505 identity_keys[n_ids] = public;
1506 /* point to the original path, most likely the private key */
1507 identity_files[n_ids] = xstrdup(filename);
1510 options.num_identity_files = n_ids;
1511 memcpy(options.identity_files, identity_files, sizeof(identity_files));
1512 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys));
1514 bzero(pwname, strlen(pwname));
1516 bzero(pwdir, strlen(pwdir));