1 /* $OpenBSD: ssh.c,v 1.324 2009/02/12 03:00:56 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/socket.h>
69 #include <netinet/in.h>
70 #include <arpa/inet.h>
72 #include <openssl/evp.h>
73 #include <openssl/err.h>
74 #include "openbsd-compat/openssl-compat.h"
75 #include "openbsd-compat/sys-queue.h"
89 #include "pathnames.h"
91 #include "clientloop.h"
94 #include "sshconnect.h"
108 extern char *__progname;
110 /* Flag indicating whether debug mode is on. May be set on the command line. */
113 /* Flag indicating whether a tty should be allocated */
116 int force_tty_flag = 0;
118 /* don't exec a shell */
119 int no_shell_flag = 0;
122 * Flag indicating that nothing should be read from stdin. This can be set
123 * on the command line.
125 int stdin_null_flag = 0;
128 * Flag indicating that ssh should fork after authentication. This is useful
129 * so that the passphrase can be entered manually, and then ssh goes to the
132 int fork_after_authentication_flag = 0;
135 * General data structure for command line options and options configurable
136 * in configuration files. See readconf.h.
140 /* optional user configfile */
144 * Name of the host we are connecting to. This is the name given on the
145 * command line, or the HostName specified for the user-supplied name in a
146 * configuration file.
150 /* socket address the host resolves to */
151 struct sockaddr_storage hostaddr;
153 /* Private host keys. */
154 Sensitive sensitive_data;
156 /* Original real UID. */
157 uid_t original_real_uid;
158 uid_t original_effective_uid;
160 /* command to be executed */
163 /* Should we execute a command or invoke a subsystem? */
164 int subsystem_flag = 0;
166 /* # of replies received for global requests */
167 static int remote_forward_confirms_received = 0;
169 /* pid of proxycommand child process */
170 pid_t proxy_command_pid = 0;
173 extern int muxserver_sock;
174 extern u_int muxclient_command;
176 /* Prints a help message to the user. This function never returns. */
182 "usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n"
183 " [-D [bind_address:]port] [-e escape_char] [-F configfile]\n"
184 " [-i identity_file] [-L [bind_address:]port:host:hostport]\n"
185 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
186 " [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
187 " [-w local_tun[:remote_tun]] [user@]hostname [command]\n"
192 static int ssh_session(void);
193 static int ssh_session2(void);
194 static void load_public_identity_files(void);
196 /* from muxclient.c */
197 void muxclient(const char *);
198 void muxserver_listen(void);
201 * Main program for the ssh client.
204 main(int ac, char **av)
206 int i, opt, exit_status, use_syslog;
207 char *p, *cp, *line, buf[256];
210 int dummy, timeout_ms;
211 extern int optind, optreset;
216 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
219 __progname = ssh_get_progname(av[0]);
223 * Save the original real uid. It will be needed later (uid-swapping
224 * may clobber the real uid).
226 original_real_uid = getuid();
227 original_effective_uid = geteuid();
230 * Use uid-swapping to give up root privileges for the duration of
231 * option processing. We will re-instantiate the rights when we are
232 * ready to create the privileged port, and will permanently drop
233 * them when the port has been created (actually, when the connection
234 * has been made, as we may need to create the port several times).
238 #ifdef HAVE_SETRLIMIT
239 /* If we are installed setuid root be careful to not drop core. */
240 if (original_real_uid != original_effective_uid) {
242 rlim.rlim_cur = rlim.rlim_max = 0;
243 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
244 fatal("setrlimit failed: %.100s", strerror(errno));
248 pw = getpwuid(original_real_uid);
250 logit("You don't exist, go away!");
253 /* Take a copy of the returned structure. */
257 * Set our umask to something reasonable, as some files are created
258 * with the default umask. This will make them world-readable but
259 * writable only by the owner, which is ok for all files for which we
260 * don't set the modes explicitly.
265 * Initialize option structure to indicate that no values have been
268 initialize_options(&options);
270 /* Parse command-line arguments. */
275 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
276 "ACD:F:I:KL:MNO:PR:S:TVw:XYy")) != -1) {
279 options.protocol = SSH_PROTO_1;
282 options.protocol = SSH_PROTO_2;
285 options.address_family = AF_INET;
288 options.address_family = AF_INET6;
294 fork_after_authentication_flag = 1;
298 options.forward_x11 = 0;
301 options.forward_x11 = 1;
307 options.forward_x11 = 1;
308 options.forward_x11_trusted = 1;
311 options.gateway_ports = 1;
314 if (strcmp(optarg, "check") == 0)
315 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
316 else if (strcmp(optarg, "exit") == 0)
317 muxclient_command = SSHMUX_COMMAND_TERMINATE;
319 fatal("Invalid multiplex command.");
321 case 'P': /* deprecated */
322 options.use_privileged_port = 0;
325 options.forward_agent = 0;
328 options.forward_agent = 1;
331 options.gss_deleg_creds = 0;
334 options.gss_authentication = 1;
335 options.gss_deleg_creds = 1;
338 if (stat(optarg, &st) < 0) {
339 fprintf(stderr, "Warning: Identity file %s "
340 "not accessible: %s.\n", optarg,
344 if (options.num_identity_files >=
345 SSH_MAX_IDENTITY_FILES)
346 fatal("Too many identity files specified "
347 "(max %d)", SSH_MAX_IDENTITY_FILES);
348 options.identity_files[options.num_identity_files++] =
353 options.smartcard_device = xstrdup(optarg);
355 fprintf(stderr, "no support for smartcards.\n");
364 if (debug_flag == 0) {
366 options.log_level = SYSLOG_LEVEL_DEBUG1;
368 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
374 fprintf(stderr, "%s, %s\n",
375 SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
380 if (options.tun_open == -1)
381 options.tun_open = SSH_TUNMODE_DEFAULT;
382 options.tun_local = a2tun(optarg, &options.tun_remote);
383 if (options.tun_local == SSH_TUNID_ERR) {
385 "Bad tun device '%s'\n", optarg);
390 options.log_level = SYSLOG_LEVEL_QUIET;
393 if (optarg[0] == '^' && optarg[2] == 0 &&
394 (u_char) optarg[1] >= 64 &&
395 (u_char) optarg[1] < 128)
396 options.escape_char = (u_char) optarg[1] & 31;
397 else if (strlen(optarg) == 1)
398 options.escape_char = (u_char) optarg[0];
399 else if (strcmp(optarg, "none") == 0)
400 options.escape_char = SSH_ESCAPECHAR_NONE;
402 fprintf(stderr, "Bad escape character '%s'.\n",
408 if (ciphers_valid(optarg)) {
410 options.ciphers = xstrdup(optarg);
411 options.cipher = SSH_CIPHER_INVALID;
414 options.cipher = cipher_number(optarg);
415 if (options.cipher == -1) {
417 "Unknown cipher type '%s'\n",
421 if (options.cipher == SSH_CIPHER_3DES)
422 options.ciphers = "3des-cbc";
423 else if (options.cipher == SSH_CIPHER_BLOWFISH)
424 options.ciphers = "blowfish-cbc";
426 options.ciphers = (char *)-1;
430 if (mac_valid(optarg))
431 options.macs = xstrdup(optarg);
433 fprintf(stderr, "Unknown mac type '%s'\n",
439 if (options.control_master == SSHCTL_MASTER_YES)
440 options.control_master = SSHCTL_MASTER_ASK;
442 options.control_master = SSHCTL_MASTER_YES;
445 options.port = a2port(optarg);
446 if (options.port <= 0) {
447 fprintf(stderr, "Bad port '%s'\n", optarg);
452 options.user = optarg;
456 if (parse_forward(&fwd, optarg, 0, 0))
457 add_local_forward(&options, &fwd);
460 "Bad local forwarding specification '%s'\n",
467 if (parse_forward(&fwd, optarg, 0, 1)) {
468 add_remote_forward(&options, &fwd);
471 "Bad remote forwarding specification "
478 if (parse_forward(&fwd, optarg, 1, 0)) {
479 add_local_forward(&options, &fwd);
482 "Bad dynamic forwarding specification "
489 options.compression = 1;
500 line = xstrdup(optarg);
501 if (process_config_line(&options, host ? host : "",
502 line, "command-line", 0, &dummy) != 0)
510 if (options.control_path != NULL)
511 free(options.control_path);
512 options.control_path = xstrdup(optarg);
515 options.bind_address = optarg;
528 if (ac > 0 && !host && **av != '-') {
529 if (strrchr(*av, '@')) {
531 cp = strrchr(p, '@');
532 if (cp == NULL || cp == p)
540 optind = optreset = 1;
546 /* Check that we got a host name. */
550 SSLeay_add_all_algorithms();
551 ERR_load_crypto_strings();
553 /* Initialize the command to execute on remote host. */
554 buffer_init(&command);
557 * Save the command to execute on the remote host in a buffer. There
558 * is no limit on the length of the command, except by the maximum
559 * packet size. Also sets the tty flag if there is no command.
562 /* No command specified - execute shell on a tty. */
564 if (subsystem_flag) {
566 "You must specify a subsystem to invoke.\n");
570 /* A command has been specified. Store it into the buffer. */
571 for (i = 0; i < ac; i++) {
573 buffer_append(&command, " ", 1);
574 buffer_append(&command, av[i], strlen(av[i]));
578 /* Cannot fork to background if no command. */
579 if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
581 fatal("Cannot fork into background without a command "
584 /* Allocate a tty by default if no command specified. */
585 if (buffer_len(&command) == 0)
591 /* Do not allocate a tty if stdin is not a tty. */
592 if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
594 logit("Pseudo-terminal will not be allocated because "
595 "stdin is not a terminal.");
600 * Initialize "log" output. Since we are the client all output
601 * actually goes to stderr.
604 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
605 SYSLOG_FACILITY_USER, !use_syslog);
608 * Read per-user configuration file. Ignore the system wide config
609 * file if the user specifies a config file on the command line.
611 if (config != NULL) {
612 if (!read_config_file(config, host, &options, 0))
613 fatal("Can't open user config file %.100s: "
614 "%.100s", config, strerror(errno));
616 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
617 _PATH_SSH_USER_CONFFILE);
618 (void)read_config_file(buf, host, &options, 1);
620 /* Read systemwide configuration file after use config. */
621 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
625 /* Fill configuration defaults. */
626 fill_default_options(&options);
628 channel_set_af(options.address_family);
631 log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
635 if (options.user == NULL)
636 options.user = xstrdup(pw->pw_name);
638 /* Get default port if port has not been set. */
639 if (options.port == 0) {
640 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
641 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
644 if (options.local_command != NULL) {
645 char thishost[NI_MAXHOST];
647 if (gethostname(thishost, sizeof(thishost)) == -1)
648 fatal("gethostname: %s", strerror(errno));
649 snprintf(buf, sizeof(buf), "%d", options.port);
650 debug3("expanding LocalCommand: %s", options.local_command);
651 cp = options.local_command;
652 options.local_command = percent_expand(cp, "d", pw->pw_dir,
653 "h", options.hostname? options.hostname : host,
654 "l", thishost, "n", host, "r", options.user, "p", buf,
655 "u", pw->pw_name, (char *)NULL);
656 debug3("expanded LocalCommand: %s", options.local_command);
660 if (options.hostname != NULL)
661 host = options.hostname;
663 /* force lowercase for hostkey matching */
664 if (options.host_key_alias != NULL) {
665 for (p = options.host_key_alias; *p; p++)
667 *p = (char)tolower(*p);
670 if (options.proxy_command != NULL &&
671 strcmp(options.proxy_command, "none") == 0) {
672 xfree(options.proxy_command);
673 options.proxy_command = NULL;
675 if (options.control_path != NULL &&
676 strcmp(options.control_path, "none") == 0) {
677 xfree(options.control_path);
678 options.control_path = NULL;
681 if (options.control_path != NULL) {
682 char thishost[NI_MAXHOST];
684 if (gethostname(thishost, sizeof(thishost)) == -1)
685 fatal("gethostname: %s", strerror(errno));
686 snprintf(buf, sizeof(buf), "%d", options.port);
687 cp = tilde_expand_filename(options.control_path,
689 xfree(options.control_path);
690 options.control_path = percent_expand(cp, "p", buf, "h", host,
691 "r", options.user, "l", thishost, (char *)NULL);
694 if (muxclient_command != 0 && options.control_path == NULL)
695 fatal("No ControlPath specified for \"-O\" command");
696 if (options.control_path != NULL)
697 muxclient(options.control_path);
699 timeout_ms = options.connection_timeout * 1000;
701 /* Open a connection to the remote host. */
702 if (ssh_connect(host, &hostaddr, options.port,
703 options.address_family, options.connection_attempts, &timeout_ms,
704 options.tcp_keep_alive,
706 options.use_privileged_port,
708 original_effective_uid == 0 && options.use_privileged_port,
710 options.proxy_command) != 0)
714 debug3("timeout: %d ms remain after connect", timeout_ms);
717 * If we successfully made the connection, load the host private key
718 * in case we will need it later for combined rsa-rhosts
719 * authentication. This must be done before releasing extra
720 * privileges, because the file is only readable by root.
721 * If we cannot access the private keys, load the public keys
722 * instead and try to execute the ssh-keysign helper instead.
724 sensitive_data.nkeys = 0;
725 sensitive_data.keys = NULL;
726 sensitive_data.external_keysign = 0;
727 if (options.rhosts_rsa_authentication ||
728 options.hostbased_authentication) {
729 sensitive_data.nkeys = 3;
730 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
734 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
735 _PATH_HOST_KEY_FILE, "", NULL, NULL);
736 sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
737 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
738 sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
739 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
742 if (options.hostbased_authentication == 1 &&
743 sensitive_data.keys[0] == NULL &&
744 sensitive_data.keys[1] == NULL &&
745 sensitive_data.keys[2] == NULL) {
746 sensitive_data.keys[1] = key_load_public(
747 _PATH_HOST_DSA_KEY_FILE, NULL);
748 sensitive_data.keys[2] = key_load_public(
749 _PATH_HOST_RSA_KEY_FILE, NULL);
750 sensitive_data.external_keysign = 1;
754 * Get rid of any extra privileges that we may have. We will no
755 * longer need them. Also, extra privileges could make it very hard
756 * to read identity files and other non-world-readable files from the
757 * user's home directory if it happens to be on a NFS volume where
758 * root is mapped to nobody.
760 if (original_effective_uid == 0) {
762 permanently_set_uid(pw);
766 * Now that we are back to our own permissions, create ~/.ssh
767 * directory if it doesn't already exist.
769 snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir,
770 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
771 if (stat(buf, &st) < 0)
772 if (mkdir(buf, 0700) < 0)
773 error("Could not create directory '%.200s'.", buf);
775 /* load options.identity_files */
776 load_public_identity_files();
778 /* Expand ~ in known host file names. */
780 options.system_hostfile =
781 tilde_expand_filename(options.system_hostfile, original_real_uid);
782 options.user_hostfile =
783 tilde_expand_filename(options.user_hostfile, original_real_uid);
784 options.system_hostfile2 =
785 tilde_expand_filename(options.system_hostfile2, original_real_uid);
786 options.user_hostfile2 =
787 tilde_expand_filename(options.user_hostfile2, original_real_uid);
789 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
791 /* Log into the remote system. Never returns if the login fails. */
792 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
795 /* We no longer need the private host keys. Clear them now. */
796 if (sensitive_data.nkeys != 0) {
797 for (i = 0; i < sensitive_data.nkeys; i++) {
798 if (sensitive_data.keys[i] != NULL) {
799 /* Destroys contents safely */
800 debug3("clear hostkey %d", i);
801 key_free(sensitive_data.keys[i]);
802 sensitive_data.keys[i] = NULL;
805 xfree(sensitive_data.keys);
807 for (i = 0; i < options.num_identity_files; i++) {
808 if (options.identity_files[i]) {
809 xfree(options.identity_files[i]);
810 options.identity_files[i] = NULL;
812 if (options.identity_keys[i]) {
813 key_free(options.identity_keys[i]);
814 options.identity_keys[i] = NULL;
818 exit_status = compat20 ? ssh_session2() : ssh_session();
821 if (options.control_path != NULL && muxserver_sock != -1)
822 unlink(options.control_path);
825 * Send SIGHUP to proxy command if used. We don't wait() in
826 * case it hangs and instead rely on init to reap the child
828 if (proxy_command_pid > 1)
829 kill(proxy_command_pid, SIGHUP);
834 /* Callback for remote forward global requests */
836 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
838 Forward *rfwd = (Forward *)ctxt;
840 /* XXX verbose() on failure? */
841 debug("remote forward %s for: listen %d, connect %s:%d",
842 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
843 rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
844 if (type == SSH2_MSG_REQUEST_SUCCESS && rfwd->listen_port == 0) {
845 logit("Allocated port %u for remote forward to %s:%d",
847 rfwd->connect_host, rfwd->connect_port);
850 if (type == SSH2_MSG_REQUEST_FAILURE) {
851 if (options.exit_on_forward_failure)
852 fatal("Error: remote port forwarding failed for "
853 "listen port %d", rfwd->listen_port);
855 logit("Warning: remote port forwarding failed for "
856 "listen port %d", rfwd->listen_port);
858 if (++remote_forward_confirms_received == options.num_remote_forwards) {
859 debug("All remote forwarding requests processed");
860 if (fork_after_authentication_flag) {
861 fork_after_authentication_flag = 0;
862 if (daemon(1, 1) < 0)
863 fatal("daemon() failed: %.200s",
870 ssh_init_forwarding(void)
875 /* Initiate local TCP/IP port forwardings. */
876 for (i = 0; i < options.num_local_forwards; i++) {
877 debug("Local connections to %.200s:%d forwarded to remote "
879 (options.local_forwards[i].listen_host == NULL) ?
880 (options.gateway_ports ? "*" : "LOCALHOST") :
881 options.local_forwards[i].listen_host,
882 options.local_forwards[i].listen_port,
883 options.local_forwards[i].connect_host,
884 options.local_forwards[i].connect_port);
885 success += channel_setup_local_fwd_listener(
886 options.local_forwards[i].listen_host,
887 options.local_forwards[i].listen_port,
888 options.local_forwards[i].connect_host,
889 options.local_forwards[i].connect_port,
890 options.gateway_ports);
892 if (i > 0 && success != i && options.exit_on_forward_failure)
893 fatal("Could not request local forwarding.");
894 if (i > 0 && success == 0)
895 error("Could not request local forwarding.");
897 /* Initiate remote TCP/IP port forwardings. */
898 for (i = 0; i < options.num_remote_forwards; i++) {
899 debug("Remote connections from %.200s:%d forwarded to "
900 "local address %.200s:%d",
901 (options.remote_forwards[i].listen_host == NULL) ?
902 "LOCALHOST" : options.remote_forwards[i].listen_host,
903 options.remote_forwards[i].listen_port,
904 options.remote_forwards[i].connect_host,
905 options.remote_forwards[i].connect_port);
906 if (channel_request_remote_forwarding(
907 options.remote_forwards[i].listen_host,
908 options.remote_forwards[i].listen_port,
909 options.remote_forwards[i].connect_host,
910 options.remote_forwards[i].connect_port) < 0) {
911 if (options.exit_on_forward_failure)
912 fatal("Could not request remote forwarding.");
914 logit("Warning: Could not request remote "
917 client_register_global_confirm(ssh_confirm_remote_forward,
918 &options.remote_forwards[i]);
921 /* Initiate tunnel forwarding. */
922 if (options.tun_open != SSH_TUNMODE_NO) {
923 if (client_request_tun_fwd(options.tun_open,
924 options.tun_local, options.tun_remote) == -1) {
925 if (options.exit_on_forward_failure)
926 fatal("Could not request tunnel forwarding.");
928 error("Could not request tunnel forwarding.");
934 check_agent_present(void)
936 if (options.forward_agent) {
937 /* Clear agent forwarding if we don't have an agent. */
938 if (!ssh_agent_present())
939 options.forward_agent = 0;
953 /* Enable compression if requested. */
954 if (options.compression) {
955 debug("Requesting compression at level %d.",
956 options.compression_level);
958 if (options.compression_level < 1 ||
959 options.compression_level > 9)
960 fatal("Compression level must be from 1 (fast) to "
963 /* Send the request. */
964 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
965 packet_put_int(options.compression_level);
968 type = packet_read();
969 if (type == SSH_SMSG_SUCCESS)
970 packet_start_compression(options.compression_level);
971 else if (type == SSH_SMSG_FAILURE)
972 logit("Warning: Remote host refused compression.");
974 packet_disconnect("Protocol error waiting for "
975 "compression response.");
977 /* Allocate a pseudo tty if appropriate. */
979 debug("Requesting pty.");
981 /* Start the packet. */
982 packet_start(SSH_CMSG_REQUEST_PTY);
984 /* Store TERM in the packet. There is no limit on the
985 length of the string. */
989 packet_put_cstring(cp);
991 /* Store window size in the packet. */
992 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
993 memset(&ws, 0, sizeof(ws));
994 packet_put_int((u_int)ws.ws_row);
995 packet_put_int((u_int)ws.ws_col);
996 packet_put_int((u_int)ws.ws_xpixel);
997 packet_put_int((u_int)ws.ws_ypixel);
999 /* Store tty modes in the packet. */
1000 tty_make_modes(fileno(stdin), NULL);
1002 /* Send the packet, and wait for it to leave. */
1004 packet_write_wait();
1006 /* Read response from the server. */
1007 type = packet_read();
1008 if (type == SSH_SMSG_SUCCESS) {
1011 } else if (type == SSH_SMSG_FAILURE)
1012 logit("Warning: Remote host failed or refused to "
1013 "allocate a pseudo tty.");
1015 packet_disconnect("Protocol error waiting for pty "
1016 "request response.");
1018 /* Request X11 forwarding if enabled and DISPLAY is set. */
1019 display = getenv("DISPLAY");
1020 if (options.forward_x11 && display != NULL) {
1022 /* Get reasonable local authentication information. */
1023 client_x11_get_proto(display, options.xauth_location,
1024 options.forward_x11_trusted, &proto, &data);
1025 /* Request forwarding with authentication spoofing. */
1026 debug("Requesting X11 forwarding with authentication "
1028 x11_request_forwarding_with_spoofing(0, display, proto, data);
1030 /* Read response from the server. */
1031 type = packet_read();
1032 if (type == SSH_SMSG_SUCCESS) {
1034 } else if (type == SSH_SMSG_FAILURE) {
1035 logit("Warning: Remote host denied X11 forwarding.");
1037 packet_disconnect("Protocol error waiting for X11 "
1041 /* Tell the packet module whether this is an interactive session. */
1042 packet_set_interactive(interactive);
1044 /* Request authentication agent forwarding if appropriate. */
1045 check_agent_present();
1047 if (options.forward_agent) {
1048 debug("Requesting authentication agent forwarding.");
1049 auth_request_forwarding();
1051 /* Read response from the server. */
1052 type = packet_read();
1054 if (type != SSH_SMSG_SUCCESS)
1055 logit("Warning: Remote host denied authentication agent forwarding.");
1058 /* Initiate port forwardings. */
1059 ssh_init_forwarding();
1061 /* Execute a local command */
1062 if (options.local_command != NULL &&
1063 options.permit_local_command)
1064 ssh_local_cmd(options.local_command);
1067 * If requested and we are not interested in replies to remote
1068 * forwarding requests, then let ssh continue in the background.
1070 if (fork_after_authentication_flag &&
1071 (!options.exit_on_forward_failure ||
1072 options.num_remote_forwards == 0)) {
1073 fork_after_authentication_flag = 0;
1074 if (daemon(1, 1) < 0)
1075 fatal("daemon() failed: %.200s", strerror(errno));
1079 * If a command was specified on the command line, execute the
1080 * command now. Otherwise request the server to start a shell.
1082 if (buffer_len(&command) > 0) {
1083 int len = buffer_len(&command);
1086 debug("Sending command: %.*s", len,
1087 (u_char *)buffer_ptr(&command));
1088 packet_start(SSH_CMSG_EXEC_CMD);
1089 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1091 packet_write_wait();
1093 debug("Requesting shell.");
1094 packet_start(SSH_CMSG_EXEC_SHELL);
1096 packet_write_wait();
1099 /* Enter the interactive session. */
1100 return client_loop(have_tty, tty_flag ?
1101 options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1104 /* request pty/x11/agent/tcpfwd/shell for channel */
1106 ssh_session2_setup(int id, void *arg)
1108 extern char **environ;
1109 const char *display;
1110 int interactive = tty_flag;
1112 display = getenv("DISPLAY");
1113 if (options.forward_x11 && display != NULL) {
1115 /* Get reasonable local authentication information. */
1116 client_x11_get_proto(display, options.xauth_location,
1117 options.forward_x11_trusted, &proto, &data);
1118 /* Request forwarding with authentication spoofing. */
1119 debug("Requesting X11 forwarding with authentication "
1121 x11_request_forwarding_with_spoofing(id, display, proto, data);
1123 /* XXX wait for reply */
1126 check_agent_present();
1127 if (options.forward_agent) {
1128 debug("Requesting authentication agent forwarding.");
1129 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1133 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1134 NULL, fileno(stdin), &command, environ);
1136 packet_set_interactive(interactive);
1139 /* open new channel for a session */
1141 ssh_session2_open(void)
1144 int window, packetmax, in, out, err;
1146 if (stdin_null_flag) {
1147 in = open(_PATH_DEVNULL, O_RDONLY);
1149 in = dup(STDIN_FILENO);
1151 out = dup(STDOUT_FILENO);
1152 err = dup(STDERR_FILENO);
1154 if (in < 0 || out < 0 || err < 0)
1155 fatal("dup() in/out/err failed");
1157 /* enable nonblocking unless tty */
1165 window = CHAN_SES_WINDOW_DEFAULT;
1166 packetmax = CHAN_SES_PACKET_DEFAULT;
1172 "session", SSH_CHANNEL_OPENING, in, out, err,
1173 window, packetmax, CHAN_EXTENDED_WRITE,
1174 "client-session", /*nonblock*/0);
1176 debug3("ssh_session2_open: channel_new: %d", c->self);
1178 channel_send_open(c->self);
1180 channel_register_open_confirm(c->self,
1181 ssh_session2_setup, NULL);
1191 /* XXX should be pre-session */
1192 ssh_init_forwarding();
1194 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1195 id = ssh_session2_open();
1197 /* If we don't expect to open a new session, then disallow it */
1198 if (options.control_master == SSHCTL_MASTER_NO &&
1199 (datafellows & SSH_NEW_OPENSSH)) {
1200 debug("Requesting no-more-sessions@openssh.com");
1201 packet_start(SSH2_MSG_GLOBAL_REQUEST);
1202 packet_put_cstring("no-more-sessions@openssh.com");
1207 /* Execute a local command */
1208 if (options.local_command != NULL &&
1209 options.permit_local_command)
1210 ssh_local_cmd(options.local_command);
1212 /* Start listening for multiplex clients */
1215 /* If requested, let ssh continue in the background. */
1216 if (fork_after_authentication_flag) {
1217 fork_after_authentication_flag = 0;
1218 if (daemon(1, 1) < 0)
1219 fatal("daemon() failed: %.200s", strerror(errno));
1222 return client_loop(tty_flag, tty_flag ?
1223 options.escape_char : SSH_ESCAPECHAR_NONE, id);
1227 load_public_identity_files(void)
1229 char *filename, *cp, thishost[NI_MAXHOST];
1230 char *pwdir = NULL, *pwname = NULL;
1237 if (options.smartcard_device != NULL &&
1238 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1239 (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL) {
1241 for (i = 0; keys[i] != NULL; i++) {
1243 memmove(&options.identity_files[1],
1244 &options.identity_files[0],
1245 sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1));
1246 memmove(&options.identity_keys[1],
1247 &options.identity_keys[0],
1248 sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1));
1249 options.num_identity_files++;
1250 options.identity_keys[0] = keys[i];
1251 options.identity_files[0] = sc_get_key_label(keys[i]);
1253 if (options.num_identity_files > SSH_MAX_IDENTITY_FILES)
1254 options.num_identity_files = SSH_MAX_IDENTITY_FILES;
1258 #endif /* SMARTCARD */
1259 if ((pw = getpwuid(original_real_uid)) == NULL)
1260 fatal("load_public_identity_files: getpwuid failed");
1261 pwname = xstrdup(pw->pw_name);
1262 pwdir = xstrdup(pw->pw_dir);
1263 if (gethostname(thishost, sizeof(thishost)) == -1)
1264 fatal("load_public_identity_files: gethostname: %s",
1266 for (; i < options.num_identity_files; i++) {
1267 cp = tilde_expand_filename(options.identity_files[i],
1269 filename = percent_expand(cp, "d", pwdir,
1270 "u", pwname, "l", thishost, "h", host,
1271 "r", options.user, (char *)NULL);
1273 public = key_load_public(filename, NULL);
1274 debug("identity file %s type %d", filename,
1275 public ? public->type : -1);
1276 xfree(options.identity_files[i]);
1277 options.identity_files[i] = filename;
1278 options.identity_keys[i] = public;
1280 bzero(pwname, strlen(pwname));
1282 bzero(pwdir, strlen(pwdir));