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;
549 line = xstrdup(optarg);
550 if (process_config_line(&options, host ? host : "",
551 line, "command-line", 0, &dummy) != 0)
557 /* ensure that the user doesn't try to backdoor a */
558 /* null cipher switch on an interactive session */
559 /* so explicitly disable it no matter what */
560 options.none_switch=0;
566 if (options.control_path != NULL)
567 free(options.control_path);
568 options.control_path = xstrdup(optarg);
571 options.bind_address = optarg;
584 if (ac > 0 && !host) {
585 if (strrchr(*av, '@')) {
587 cp = strrchr(p, '@');
588 if (cp == NULL || cp == p)
596 optind = optreset = 1;
602 /* Check that we got a host name. */
606 SSLeay_add_all_algorithms();
607 ERR_load_crypto_strings();
609 /* Initialize the command to execute on remote host. */
610 buffer_init(&command);
613 * Save the command to execute on the remote host in a buffer. There
614 * is no limit on the length of the command, except by the maximum
615 * packet size. Also sets the tty flag if there is no command.
618 /* No command specified - execute shell on a tty. */
620 if (subsystem_flag) {
622 "You must specify a subsystem to invoke.\n");
626 /* A command has been specified. Store it into the buffer. */
627 for (i = 0; i < ac; i++) {
629 buffer_append(&command, " ", 1);
630 buffer_append(&command, av[i], strlen(av[i]));
634 /* Cannot fork to background if no command. */
635 if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
637 fatal("Cannot fork into background without a command "
640 /* Allocate a tty by default if no command specified. */
641 if (buffer_len(&command) == 0)
645 if (no_tty_flag || muxclient_command != 0)
647 /* Do not allocate a tty if stdin is not a tty. */
648 if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
650 logit("Pseudo-terminal will not be allocated because "
651 "stdin is not a terminal.");
656 * Initialize "log" output. Since we are the client all output
657 * actually goes to stderr.
660 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
661 SYSLOG_FACILITY_USER, !use_syslog);
664 * Read per-user configuration file. Ignore the system wide config
665 * file if the user specifies a config file on the command line.
667 if (config != NULL) {
668 if (!read_config_file(config, host, &options, 0))
669 fatal("Can't open user config file %.100s: "
670 "%.100s", config, strerror(errno));
672 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
673 _PATH_SSH_USER_CONFFILE);
674 if (r > 0 && (size_t)r < sizeof(buf))
675 (void)read_config_file(buf, host, &options, 1);
677 /* Read systemwide configuration file after use config. */
678 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
682 /* Fill configuration defaults. */
683 fill_default_options(&options);
685 channel_set_af(options.address_family);
688 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
692 if (options.user == NULL)
693 options.user = xstrdup(pw->pw_name);
695 /* Get default port if port has not been set. */
696 if (options.port == 0) {
697 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
698 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
701 if (options.hostname != NULL) {
702 host = percent_expand(options.hostname,
703 "h", host, (char *)NULL);
706 if (options.local_command != NULL) {
707 char thishost[NI_MAXHOST];
709 if (gethostname(thishost, sizeof(thishost)) == -1)
710 fatal("gethostname: %s", strerror(errno));
711 snprintf(buf, sizeof(buf), "%d", options.port);
712 debug3("expanding LocalCommand: %s", options.local_command);
713 cp = options.local_command;
714 options.local_command = percent_expand(cp, "d", pw->pw_dir,
715 "h", host, "l", thishost, "n", host, "r", options.user,
716 "p", buf, "u", pw->pw_name, (char *)NULL);
717 debug3("expanded LocalCommand: %s", options.local_command);
721 /* force lowercase for hostkey matching */
722 if (options.host_key_alias != NULL) {
723 for (p = options.host_key_alias; *p; p++)
725 *p = (char)tolower(*p);
728 if (options.proxy_command != NULL &&
729 strcmp(options.proxy_command, "none") == 0) {
730 xfree(options.proxy_command);
731 options.proxy_command = NULL;
733 if (options.control_path != NULL &&
734 strcmp(options.control_path, "none") == 0) {
735 xfree(options.control_path);
736 options.control_path = NULL;
739 if (options.control_path != NULL) {
740 char thishost[NI_MAXHOST];
742 if (gethostname(thishost, sizeof(thishost)) == -1)
743 fatal("gethostname: %s", strerror(errno));
744 snprintf(buf, sizeof(buf), "%d", options.port);
745 cp = tilde_expand_filename(options.control_path,
747 xfree(options.control_path);
748 options.control_path = percent_expand(cp, "p", buf, "h", host,
749 "r", options.user, "l", thishost, (char *)NULL);
752 if (muxclient_command != 0 && options.control_path == NULL)
753 fatal("No ControlPath specified for \"-O\" command");
754 if (options.control_path != NULL)
755 muxclient(options.control_path);
757 timeout_ms = options.connection_timeout * 1000;
759 /* Open a connection to the remote host. */
760 if (ssh_connect(host, &hostaddr, options.port,
761 options.address_family, options.connection_attempts, &timeout_ms,
762 options.tcp_keep_alive,
764 options.use_privileged_port,
766 original_effective_uid == 0 && options.use_privileged_port,
768 options.proxy_command) != 0)
772 debug3("timeout: %d ms remain after connect", timeout_ms);
775 * If we successfully made the connection, load the host private key
776 * in case we will need it later for combined rsa-rhosts
777 * authentication. This must be done before releasing extra
778 * privileges, because the file is only readable by root.
779 * If we cannot access the private keys, load the public keys
780 * instead and try to execute the ssh-keysign helper instead.
782 sensitive_data.nkeys = 0;
783 sensitive_data.keys = NULL;
784 sensitive_data.external_keysign = 0;
785 if (options.rhosts_rsa_authentication ||
786 options.hostbased_authentication) {
787 sensitive_data.nkeys = 5;
788 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
792 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
793 _PATH_HOST_KEY_FILE, "", NULL, NULL);
794 sensitive_data.keys[1] = key_load_private_cert(KEY_DSA,
795 _PATH_HOST_DSA_KEY_FILE, "", NULL);
796 sensitive_data.keys[2] = key_load_private_cert(KEY_RSA,
797 _PATH_HOST_RSA_KEY_FILE, "", NULL);
798 sensitive_data.keys[3] = key_load_private_type(KEY_DSA,
799 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
800 sensitive_data.keys[4] = key_load_private_type(KEY_RSA,
801 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
804 if (options.hostbased_authentication == 1 &&
805 sensitive_data.keys[0] == NULL &&
806 sensitive_data.keys[3] == NULL &&
807 sensitive_data.keys[4] == NULL) {
808 sensitive_data.keys[1] = key_load_cert(
809 _PATH_HOST_DSA_KEY_FILE);
810 sensitive_data.keys[2] = key_load_cert(
811 _PATH_HOST_RSA_KEY_FILE);
812 sensitive_data.keys[3] = key_load_public(
813 _PATH_HOST_DSA_KEY_FILE, NULL);
814 sensitive_data.keys[4] = key_load_public(
815 _PATH_HOST_RSA_KEY_FILE, NULL);
816 sensitive_data.external_keysign = 1;
820 * Get rid of any extra privileges that we may have. We will no
821 * longer need them. Also, extra privileges could make it very hard
822 * to read identity files and other non-world-readable files from the
823 * user's home directory if it happens to be on a NFS volume where
824 * root is mapped to nobody.
826 if (original_effective_uid == 0) {
828 permanently_set_uid(pw);
832 * Now that we are back to our own permissions, create ~/.ssh
833 * directory if it doesn't already exist.
835 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir,
836 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
837 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0)
838 if (mkdir(buf, 0700) < 0)
839 error("Could not create directory '%.200s'.", buf);
841 /* load options.identity_files */
842 load_public_identity_files();
844 /* Expand ~ in known host file names. */
846 options.system_hostfile =
847 tilde_expand_filename(options.system_hostfile, original_real_uid);
848 options.user_hostfile =
849 tilde_expand_filename(options.user_hostfile, original_real_uid);
850 options.system_hostfile2 =
851 tilde_expand_filename(options.system_hostfile2, original_real_uid);
852 options.user_hostfile2 =
853 tilde_expand_filename(options.user_hostfile2, original_real_uid);
855 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
857 /* Log into the remote system. Never returns if the login fails. */
858 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
861 if (packet_connection_is_on_socket()) {
862 verbose("Authenticated to %s ([%s]:%d).", host,
863 get_remote_ipaddr(), get_remote_port());
865 verbose("Authenticated to %s (via proxy).", host);
868 /* We no longer need the private host keys. Clear them now. */
869 if (sensitive_data.nkeys != 0) {
870 for (i = 0; i < sensitive_data.nkeys; i++) {
871 if (sensitive_data.keys[i] != NULL) {
872 /* Destroys contents safely */
873 debug3("clear hostkey %d", i);
874 key_free(sensitive_data.keys[i]);
875 sensitive_data.keys[i] = NULL;
878 xfree(sensitive_data.keys);
880 for (i = 0; i < options.num_identity_files; i++) {
881 if (options.identity_files[i]) {
882 xfree(options.identity_files[i]);
883 options.identity_files[i] = NULL;
885 if (options.identity_keys[i]) {
886 key_free(options.identity_keys[i]);
887 options.identity_keys[i] = NULL;
891 exit_status = compat20 ? ssh_session2() : ssh_session();
894 if (options.control_path != NULL && muxserver_sock != -1)
895 unlink(options.control_path);
898 * Send SIGHUP to proxy command if used. We don't wait() in
899 * case it hangs and instead rely on init to reap the child
901 if (proxy_command_pid > 1)
902 kill(proxy_command_pid, SIGHUP);
908 control_persist_detach(void)
913 debug("%s: backgrounding master process", __func__);
916 * master (current process) into the background, and make the
917 * foreground process a client of the backgrounded master.
919 switch ((pid = fork())) {
921 fatal("%s: fork: %s", __func__, strerror(errno));
923 /* Child: master process continues mainloop */
926 /* Parent: set up mux slave to connect to backgrounded master */
927 debug2("%s: background process is %ld", __func__, (long)pid);
928 stdin_null_flag = ostdin_null_flag;
929 no_shell_flag = ono_shell_flag;
930 no_tty_flag = ono_tty_flag;
931 tty_flag = otty_flag;
932 close(muxserver_sock);
934 muxclient(options.control_path);
935 /* muxclient() doesn't return on success. */
936 fatal("Failed to connect to new control master");
938 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
939 error("%s: open(\"/dev/null\"): %s", __func__,
942 if (dup2(devnull, STDIN_FILENO) == -1 ||
943 dup2(devnull, STDOUT_FILENO) == -1)
944 error("%s: dup2: %s", __func__, strerror(errno));
945 if (devnull > STDERR_FILENO)
950 /* Do fork() after authentication. Used by "ssh -f" */
954 if (need_controlpersist_detach)
955 control_persist_detach();
956 debug("forking to background");
957 fork_after_authentication_flag = 0;
958 if (daemon(1, 1) < 0)
959 fatal("daemon() failed: %.200s", strerror(errno));
962 /* Callback for remote forward global requests */
964 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
966 Forward *rfwd = (Forward *)ctxt;
968 /* XXX verbose() on failure? */
969 debug("remote forward %s for: listen %d, connect %s:%d",
970 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
971 rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
972 if (type == SSH2_MSG_REQUEST_SUCCESS && rfwd->listen_port == 0) {
973 rfwd->allocated_port = packet_get_int();
974 logit("Allocated port %u for remote forward to %s:%d",
975 rfwd->allocated_port,
976 rfwd->connect_host, rfwd->connect_port);
979 if (type == SSH2_MSG_REQUEST_FAILURE) {
980 if (options.exit_on_forward_failure)
981 fatal("Error: remote port forwarding failed for "
982 "listen port %d", rfwd->listen_port);
984 logit("Warning: remote port forwarding failed for "
985 "listen port %d", rfwd->listen_port);
987 if (++remote_forward_confirms_received == options.num_remote_forwards) {
988 debug("All remote forwarding requests processed");
989 if (fork_after_authentication_flag)
995 client_cleanup_stdio_fwd(int id, void *arg)
997 debug("stdio forwarding: done");
1002 client_setup_stdio_fwd(const char *host_to_connect, u_short port_to_connect)
1007 debug3("client_setup_stdio_fwd %s:%d", host_to_connect,
1010 in = dup(STDIN_FILENO);
1011 out = dup(STDOUT_FILENO);
1012 if (in < 0 || out < 0)
1013 fatal("channel_connect_stdio_fwd: dup() in/out failed");
1015 if ((c = channel_connect_stdio_fwd(host_to_connect, port_to_connect,
1018 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0);
1023 ssh_init_forwarding(void)
1028 if (stdio_forward_host != NULL) {
1030 fatal("stdio forwarding require Protocol 2");
1032 if (!client_setup_stdio_fwd(stdio_forward_host,
1033 stdio_forward_port))
1034 fatal("Failed to connect in stdio forward mode.");
1037 /* Initiate local TCP/IP port forwardings. */
1038 for (i = 0; i < options.num_local_forwards; i++) {
1039 debug("Local connections to %.200s:%d forwarded to remote "
1040 "address %.200s:%d",
1041 (options.local_forwards[i].listen_host == NULL) ?
1042 (options.gateway_ports ? "*" : "LOCALHOST") :
1043 options.local_forwards[i].listen_host,
1044 options.local_forwards[i].listen_port,
1045 options.local_forwards[i].connect_host,
1046 options.local_forwards[i].connect_port);
1047 success += channel_setup_local_fwd_listener(
1048 options.local_forwards[i].listen_host,
1049 options.local_forwards[i].listen_port,
1050 options.local_forwards[i].connect_host,
1051 options.local_forwards[i].connect_port,
1052 options.gateway_ports);
1054 if (i > 0 && success != i && options.exit_on_forward_failure)
1055 fatal("Could not request local forwarding.");
1056 if (i > 0 && success == 0)
1057 error("Could not request local forwarding.");
1059 /* Initiate remote TCP/IP port forwardings. */
1060 for (i = 0; i < options.num_remote_forwards; i++) {
1061 debug("Remote connections from %.200s:%d forwarded to "
1062 "local address %.200s:%d",
1063 (options.remote_forwards[i].listen_host == NULL) ?
1064 "LOCALHOST" : options.remote_forwards[i].listen_host,
1065 options.remote_forwards[i].listen_port,
1066 options.remote_forwards[i].connect_host,
1067 options.remote_forwards[i].connect_port);
1068 if (channel_request_remote_forwarding(
1069 options.remote_forwards[i].listen_host,
1070 options.remote_forwards[i].listen_port,
1071 options.remote_forwards[i].connect_host,
1072 options.remote_forwards[i].connect_port) < 0) {
1073 if (options.exit_on_forward_failure)
1074 fatal("Could not request remote forwarding.");
1076 logit("Warning: Could not request remote "
1079 client_register_global_confirm(ssh_confirm_remote_forward,
1080 &options.remote_forwards[i]);
1083 /* Initiate tunnel forwarding. */
1084 if (options.tun_open != SSH_TUNMODE_NO) {
1085 if (client_request_tun_fwd(options.tun_open,
1086 options.tun_local, options.tun_remote) == -1) {
1087 if (options.exit_on_forward_failure)
1088 fatal("Could not request tunnel forwarding.");
1090 error("Could not request tunnel forwarding.");
1096 check_agent_present(void)
1098 if (options.forward_agent) {
1099 /* Clear agent forwarding if we don't have an agent. */
1100 if (!ssh_agent_present())
1101 options.forward_agent = 0;
1109 int interactive = 0;
1113 const char *display;
1115 /* Enable compression if requested. */
1116 if (options.compression) {
1117 debug("Requesting compression at level %d.",
1118 options.compression_level);
1120 if (options.compression_level < 1 ||
1121 options.compression_level > 9)
1122 fatal("Compression level must be from 1 (fast) to "
1125 /* Send the request. */
1126 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
1127 packet_put_int(options.compression_level);
1129 packet_write_wait();
1130 type = packet_read();
1131 if (type == SSH_SMSG_SUCCESS)
1132 packet_start_compression(options.compression_level);
1133 else if (type == SSH_SMSG_FAILURE)
1134 logit("Warning: Remote host refused compression.");
1136 packet_disconnect("Protocol error waiting for "
1137 "compression response.");
1139 /* Allocate a pseudo tty if appropriate. */
1141 debug("Requesting pty.");
1143 /* Start the packet. */
1144 packet_start(SSH_CMSG_REQUEST_PTY);
1146 /* Store TERM in the packet. There is no limit on the
1147 length of the string. */
1148 cp = getenv("TERM");
1151 packet_put_cstring(cp);
1153 /* Store window size in the packet. */
1154 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
1155 memset(&ws, 0, sizeof(ws));
1156 packet_put_int((u_int)ws.ws_row);
1157 packet_put_int((u_int)ws.ws_col);
1158 packet_put_int((u_int)ws.ws_xpixel);
1159 packet_put_int((u_int)ws.ws_ypixel);
1161 /* Store tty modes in the packet. */
1162 tty_make_modes(fileno(stdin), NULL);
1164 /* Send the packet, and wait for it to leave. */
1166 packet_write_wait();
1168 /* Read response from the server. */
1169 type = packet_read();
1170 if (type == SSH_SMSG_SUCCESS) {
1173 } else if (type == SSH_SMSG_FAILURE)
1174 logit("Warning: Remote host failed or refused to "
1175 "allocate a pseudo tty.");
1177 packet_disconnect("Protocol error waiting for pty "
1178 "request response.");
1180 /* Request X11 forwarding if enabled and DISPLAY is set. */
1181 display = getenv("DISPLAY");
1182 if (options.forward_x11 && display != NULL) {
1184 /* Get reasonable local authentication information. */
1185 client_x11_get_proto(display, options.xauth_location,
1186 options.forward_x11_trusted,
1187 options.forward_x11_timeout,
1189 /* Request forwarding with authentication spoofing. */
1190 debug("Requesting X11 forwarding with authentication "
1192 x11_request_forwarding_with_spoofing(0, display, proto, data);
1194 /* Read response from the server. */
1195 type = packet_read();
1196 if (type == SSH_SMSG_SUCCESS) {
1198 } else if (type == SSH_SMSG_FAILURE) {
1199 logit("Warning: Remote host denied X11 forwarding.");
1201 packet_disconnect("Protocol error waiting for X11 "
1205 /* Tell the packet module whether this is an interactive session. */
1206 packet_set_interactive(interactive);
1208 /* Request authentication agent forwarding if appropriate. */
1209 check_agent_present();
1211 if (options.forward_agent) {
1212 debug("Requesting authentication agent forwarding.");
1213 auth_request_forwarding();
1215 /* Read response from the server. */
1216 type = packet_read();
1218 if (type != SSH_SMSG_SUCCESS)
1219 logit("Warning: Remote host denied authentication agent forwarding.");
1222 /* Initiate port forwardings. */
1223 ssh_init_forwarding();
1225 /* Execute a local command */
1226 if (options.local_command != NULL &&
1227 options.permit_local_command)
1228 ssh_local_cmd(options.local_command);
1231 * If requested and we are not interested in replies to remote
1232 * forwarding requests, then let ssh continue in the background.
1234 if (fork_after_authentication_flag) {
1235 if (options.exit_on_forward_failure &&
1236 options.num_remote_forwards > 0) {
1237 debug("deferring postauth fork until remote forward "
1238 "confirmation received");
1244 * If a command was specified on the command line, execute the
1245 * command now. Otherwise request the server to start a shell.
1247 if (buffer_len(&command) > 0) {
1248 int len = buffer_len(&command);
1251 debug("Sending command: %.*s", len,
1252 (u_char *)buffer_ptr(&command));
1253 packet_start(SSH_CMSG_EXEC_CMD);
1254 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1256 packet_write_wait();
1258 debug("Requesting shell.");
1259 packet_start(SSH_CMSG_EXEC_SHELL);
1261 packet_write_wait();
1264 /* Enter the interactive session. */
1265 return client_loop(have_tty, tty_flag ?
1266 options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1269 /* request pty/x11/agent/tcpfwd/shell for channel */
1271 ssh_session2_setup(int id, int success, void *arg)
1273 extern char **environ;
1274 const char *display;
1275 int interactive = tty_flag;
1278 return; /* No need for error message, channels code sens one */
1280 display = getenv("DISPLAY");
1281 if (options.forward_x11 && display != NULL) {
1283 /* Get reasonable local authentication information. */
1284 client_x11_get_proto(display, options.xauth_location,
1285 options.forward_x11_trusted,
1286 options.forward_x11_timeout, &proto, &data);
1287 /* Request forwarding with authentication spoofing. */
1288 debug("Requesting X11 forwarding with authentication "
1290 x11_request_forwarding_with_spoofing(id, display, proto, data);
1292 /* XXX wait for reply */
1295 check_agent_present();
1296 if (options.forward_agent) {
1297 debug("Requesting authentication agent forwarding.");
1298 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1302 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1303 NULL, fileno(stdin), &command, environ);
1305 packet_set_interactive(interactive);
1308 /* open new channel for a session */
1310 ssh_session2_open(void)
1313 int window, packetmax, in, out, err;
1316 int socksizelen = sizeof(int);
1318 if (stdin_null_flag) {
1319 in = open(_PATH_DEVNULL, O_RDONLY);
1321 in = dup(STDIN_FILENO);
1323 out = dup(STDOUT_FILENO);
1324 err = dup(STDERR_FILENO);
1326 if (in < 0 || out < 0 || err < 0)
1327 fatal("dup() in/out/err failed");
1329 /* enable nonblocking unless tty */
1337 /* we need to check to see if what they want to do about buffer */
1338 /* sizes here. In a hpn to nonhpn connection we want to limit */
1339 /* the window size to something reasonable in case the far side */
1340 /* has the large window bug. In hpn to hpn connection we want to */
1341 /* use the max window size but allow the user to override it */
1342 /* lastly if they disabled hpn then use the ssh std window size */
1344 /* so why don't we just do a getsockopt() here and set the */
1345 /* ssh window to that? In the case of a autotuning receive */
1346 /* window the window would get stuck at the initial buffer */
1347 /* size generally less than 96k. Therefore we need to set the */
1348 /* maximum ssh window size to the maximum hpn buffer size */
1349 /* unless the user has specifically set the tcprcvbufpoll */
1350 /* to no. In which case we *can* just set the window to the */
1351 /* minimum of the hpn buffer size and tcp receive buffer size */
1354 options.hpn_buffer_size = CHAN_SES_WINDOW_DEFAULT;
1356 options.hpn_buffer_size = 2*1024*1024;
1358 if (datafellows & SSH_BUG_LARGEWINDOW)
1360 debug("HPN to Non-HPN Connection");
1364 if (options.tcp_rcv_buf_poll <= 0)
1366 sock = socket(AF_INET, SOCK_STREAM, 0);
1367 getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1368 &socksize, &socksizelen);
1370 debug("socksize %d", socksize);
1371 options.hpn_buffer_size = socksize;
1372 debug ("HPNBufferSize set to TCP RWIN: %d", options.hpn_buffer_size);
1376 if (options.tcp_rcv_buf > 0)
1378 /*create a socket but don't connect it */
1379 /* we use that the get the rcv socket size */
1380 sock = socket(AF_INET, SOCK_STREAM, 0);
1381 /* if they are using the tcp_rcv_buf option */
1382 /* attempt to set the buffer size to that */
1383 if (options.tcp_rcv_buf)
1384 setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void *)&options.tcp_rcv_buf,
1385 sizeof(options.tcp_rcv_buf));
1386 getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1387 &socksize, &socksizelen);
1389 debug("socksize %d", socksize);
1390 options.hpn_buffer_size = socksize;
1391 debug ("HPNBufferSize set to user TCPRcvBuf: %d", options.hpn_buffer_size);
1397 debug("Final hpn_buffer_size = %d", options.hpn_buffer_size);
1399 window = options.hpn_buffer_size;
1401 channel_set_hpn(options.hpn_disabled, options.hpn_buffer_size);
1403 packetmax = CHAN_SES_PACKET_DEFAULT;
1405 window = 4*CHAN_SES_PACKET_DEFAULT;
1410 "session", SSH_CHANNEL_OPENING, in, out, err,
1411 window, packetmax, CHAN_EXTENDED_WRITE,
1412 "client-session", /*nonblock*/0);
1413 if ((options.tcp_rcv_buf_poll > 0) && (!options.hpn_disabled)) {
1414 c->dynamic_window = 1;
1415 debug ("Enabled Dynamic Window Scaling\n");
1417 debug3("ssh_session2_open: channel_new: %d", c->self);
1419 channel_send_open(c->self);
1421 channel_register_open_confirm(c->self,
1422 ssh_session2_setup, NULL);
1432 /* XXX should be pre-session */
1433 ssh_init_forwarding();
1435 /* Start listening for multiplex clients */
1439 * If we are in control persist mode, then prepare to background
1440 * ourselves and have a foreground client attach as a control
1441 * slave. NB. we must save copies of the flags that we override for
1442 * the backgrounding, since we defer attachment of the slave until
1443 * after the connection is fully established (in particular,
1444 * async rfwd replies have been received for ExitOnForwardFailure).
1446 if (options.control_persist && muxserver_sock != -1) {
1447 ostdin_null_flag = stdin_null_flag;
1448 ono_shell_flag = no_shell_flag;
1449 ono_tty_flag = no_tty_flag;
1450 otty_flag = tty_flag;
1451 stdin_null_flag = 1;
1455 if (!fork_after_authentication_flag)
1456 need_controlpersist_detach = 1;
1457 fork_after_authentication_flag = 1;
1460 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1461 id = ssh_session2_open();
1463 /* If we don't expect to open a new session, then disallow it */
1464 if (options.control_master == SSHCTL_MASTER_NO &&
1465 (datafellows & SSH_NEW_OPENSSH)) {
1466 debug("Requesting no-more-sessions@openssh.com");
1467 packet_start(SSH2_MSG_GLOBAL_REQUEST);
1468 packet_put_cstring("no-more-sessions@openssh.com");
1473 /* Execute a local command */
1474 if (options.local_command != NULL &&
1475 options.permit_local_command)
1476 ssh_local_cmd(options.local_command);
1479 * If requested and we are not interested in replies to remote
1480 * forwarding requests, then let ssh continue in the background.
1482 if (fork_after_authentication_flag) {
1483 if (options.exit_on_forward_failure &&
1484 options.num_remote_forwards > 0) {
1485 debug("deferring postauth fork until remote forward "
1486 "confirmation received");
1491 if (options.use_roaming)
1494 return client_loop(tty_flag, tty_flag ?
1495 options.escape_char : SSH_ESCAPECHAR_NONE, id);
1499 load_public_identity_files(void)
1501 char *filename, *cp, thishost[NI_MAXHOST];
1502 char *pwdir = NULL, *pwname = NULL;
1507 char *identity_files[SSH_MAX_IDENTITY_FILES];
1508 Key *identity_keys[SSH_MAX_IDENTITY_FILES];
1509 #ifdef ENABLE_PKCS11
1515 bzero(identity_files, sizeof(identity_files));
1516 bzero(identity_keys, sizeof(identity_keys));
1518 #ifdef ENABLE_PKCS11
1519 if (options.pkcs11_provider != NULL &&
1520 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1521 (pkcs11_init(!options.batch_mode) == 0) &&
1522 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL,
1524 for (i = 0; i < nkeys; i++) {
1525 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
1529 identity_keys[n_ids] = keys[i];
1530 identity_files[n_ids] =
1531 xstrdup(options.pkcs11_provider); /* XXX */
1536 #endif /* ENABLE_PKCS11 */
1537 if ((pw = getpwuid(original_real_uid)) == NULL)
1538 fatal("load_public_identity_files: getpwuid failed");
1539 pwname = xstrdup(pw->pw_name);
1540 pwdir = xstrdup(pw->pw_dir);
1541 if (gethostname(thishost, sizeof(thishost)) == -1)
1542 fatal("load_public_identity_files: gethostname: %s",
1544 for (i = 0; i < options.num_identity_files; i++) {
1545 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
1546 xfree(options.identity_files[i]);
1549 cp = tilde_expand_filename(options.identity_files[i],
1551 filename = percent_expand(cp, "d", pwdir,
1552 "u", pwname, "l", thishost, "h", host,
1553 "r", options.user, (char *)NULL);
1555 public = key_load_public(filename, NULL);
1556 debug("identity file %s type %d", filename,
1557 public ? public->type : -1);
1558 xfree(options.identity_files[i]);
1559 identity_files[n_ids] = filename;
1560 identity_keys[n_ids] = public;
1562 if (++n_ids >= SSH_MAX_IDENTITY_FILES)
1565 /* Try to add the certificate variant too */
1566 xasprintf(&cp, "%s-cert", filename);
1567 public = key_load_public(cp, NULL);
1568 debug("identity file %s type %d", cp,
1569 public ? public->type : -1);
1570 if (public == NULL) {
1574 if (!key_is_cert(public)) {
1575 debug("%s: key %s type %s is not a certificate",
1576 __func__, cp, key_type(public));
1581 identity_keys[n_ids] = public;
1582 /* point to the original path, most likely the private key */
1583 identity_files[n_ids] = xstrdup(filename);
1586 options.num_identity_files = n_ids;
1587 memcpy(options.identity_files, identity_files, sizeof(identity_files));
1588 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys));
1590 bzero(pwname, strlen(pwname));
1592 bzero(pwdir, strlen(pwdir));