2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * Ssh client program. This program can be used to log into a remote machine.
6 * The software supports strong authentication, encryption, and forwarding
7 * of X11, TCP/IP, and authentication connections.
9 * As far as I am concerned, the code I have written for this software
10 * can be used freely for any purpose. Any derived versions of this
11 * software must be clearly marked as such, and if the derived work is
12 * incompatible with the protocol description in the RFC file, it must be
13 * called by a name other than "ssh" or "Secure Shell".
15 * Copyright (c) 1999 Niels Provos. All rights reserved.
17 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
18 * in Canada (German citizen).
20 * Redistribution and use in source and binary forms, with or without
21 * modification, are permitted provided that the following conditions
23 * 1. Redistributions of source code must retain the above copyright
24 * notice, this list of conditions and the following disclaimer.
25 * 2. Redistributions in binary form must reproduce the above copyright
26 * notice, this list of conditions and the following disclaimer in the
27 * documentation and/or other materials provided with the distribution.
29 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
30 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
31 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
32 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
33 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
34 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
38 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 RCSID("$OpenBSD: ssh.c,v 1.116 2001/04/17 12:55:04 markus Exp $");
44 #include <openssl/evp.h>
45 #include <openssl/err.h>
60 #include "pathnames.h"
61 #include "clientloop.h"
64 #include "sshconnect.h"
65 #include "tildexpand.h"
72 #ifdef HAVE___PROGNAME
73 extern char *__progname;
78 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
79 Default value is AF_UNSPEC means both IPv4 and IPv6. */
81 int IPv4or6 = AF_INET;
83 int IPv4or6 = AF_UNSPEC;
86 /* Flag indicating whether debug mode is on. This can be set on the command line. */
89 /* Flag indicating whether a tty should be allocated */
92 int force_tty_flag = 0;
94 /* don't exec a shell */
95 int no_shell_flag = 0;
98 * Flag indicating that nothing should be read from stdin. This can be set
99 * on the command line.
101 int stdin_null_flag = 0;
104 * Flag indicating that ssh should fork after authentication. This is useful
105 * so that the pasphrase can be entered manually, and then ssh goes to the
108 int fork_after_authentication_flag = 0;
111 * General data structure for command line options and options configurable
112 * in configuration files. See readconf.h.
117 * Name of the host we are connecting to. This is the name given on the
118 * command line, or the HostName specified for the user-supplied name in a
119 * configuration file.
123 /* socket address the host resolves to */
124 struct sockaddr_storage hostaddr;
127 * Flag to indicate that we have received a window change signal which has
128 * not yet been processed. This will cause a message indicating the new
129 * window size to be sent to the server a little later. This is volatile
130 * because this is updated in a signal handler.
132 volatile int received_window_change_signal = 0;
134 /* Private host keys. */
140 /* Original real UID. */
141 uid_t original_real_uid;
143 /* command to be executed */
146 /* Should we execute a command or invoke a subsystem? */
147 int subsystem_flag = 0;
149 /* Prints a help message to the user. This function never returns. */
154 fprintf(stderr, "Usage: %s [options] host [command]\n", __progname);
155 fprintf(stderr, "Options:\n");
156 fprintf(stderr, " -l user Log in using this user name.\n");
157 fprintf(stderr, " -n Redirect input from " _PATH_DEVNULL ".\n");
158 fprintf(stderr, " -A Enable authentication agent forwarding.\n");
159 fprintf(stderr, " -a Disable authentication agent forwarding.\n");
161 fprintf(stderr, " -k Disable Kerberos ticket and AFS token forwarding.\n");
163 fprintf(stderr, " -X Enable X11 connection forwarding.\n");
164 fprintf(stderr, " -x Disable X11 connection forwarding.\n");
165 fprintf(stderr, " -i file Identity for public key authentication "
166 "(default: ~/.ssh/identity)\n");
167 fprintf(stderr, " -t Tty; allocate a tty even if command is given.\n");
168 fprintf(stderr, " -T Do not allocate a tty.\n");
169 fprintf(stderr, " -v Verbose; display verbose debugging messages.\n");
170 fprintf(stderr, " Multiple -v increases verbosity.\n");
171 fprintf(stderr, " -V Display version number only.\n");
172 fprintf(stderr, " -P Don't allocate a privileged port.\n");
173 fprintf(stderr, " -q Quiet; don't display any warning messages.\n");
174 fprintf(stderr, " -f Fork into background after authentication.\n");
175 fprintf(stderr, " -e char Set escape character; ``none'' = disable (default: ~).\n");
177 fprintf(stderr, " -c cipher Select encryption algorithm: "
178 "``3des'', ``blowfish''\n");
179 fprintf(stderr, " -m macs Specify MAC algorithms for protocol version 2.\n");
180 fprintf(stderr, " -p port Connect to this port. Server must be on the same port.\n");
181 fprintf(stderr, " -L listen-port:host:port Forward local port to remote address\n");
182 fprintf(stderr, " -R listen-port:host:port Forward remote port to local address\n");
183 fprintf(stderr, " These cause %s to listen for connections on a port, and\n", __progname);
184 fprintf(stderr, " forward them to the other side by connecting to host:port.\n");
185 fprintf(stderr, " -C Enable compression.\n");
186 fprintf(stderr, " -N Do not execute a shell or command.\n");
187 fprintf(stderr, " -g Allow remote hosts to connect to forwarded ports.\n");
188 fprintf(stderr, " -1 Force protocol version 1.\n");
189 fprintf(stderr, " -2 Force protocol version 2.\n");
190 fprintf(stderr, " -4 Use IPv4 only.\n");
191 fprintf(stderr, " -6 Use IPv6 only.\n");
192 fprintf(stderr, " -o 'option' Process the option as if it was read from a configuration file.\n");
193 fprintf(stderr, " -s Invoke command (mandatory) as SSH2 subsystem.\n");
198 * Connects to the given host using rsh (or prints an error message and exits
199 * if rsh is not available). This function never returns.
202 rsh_connect(char *host, char *user, Buffer * command)
207 log("Using rsh. WARNING: Connection will not be encrypted.");
208 /* Build argument list for rsh. */
210 args[i++] = _PATH_RSH;
211 /* host may have to come after user on some systems */
217 if (buffer_len(command) > 0) {
218 buffer_append(command, "\0", 1);
219 args[i++] = buffer_ptr(command);
223 for (i = 0; args[i]; i++) {
225 fprintf(stderr, " ");
226 fprintf(stderr, "%s", args[i]);
228 fprintf(stderr, "\n");
230 execv(_PATH_RSH, args);
235 int ssh_session(void);
236 int ssh_session2(void);
237 void load_public_identity_files(void);
240 * Main program for the ssh client.
243 main(int ac, char **av)
245 int i, opt, optind, exit_status, ok;
246 u_short fwd_port, fwd_host_port;
247 char *optarg, *cp, buf[256];
251 uid_t original_effective_uid;
253 __progname = get_progname(av[0]);
257 * Save the original real uid. It will be needed later (uid-swapping
258 * may clobber the real uid).
260 original_real_uid = getuid();
261 original_effective_uid = geteuid();
263 #ifdef HAVE_SETRLIMIT
264 /* If we are installed setuid root be careful to not drop core. */
265 if (original_real_uid != original_effective_uid) {
267 rlim.rlim_cur = rlim.rlim_max = 0;
268 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
269 fatal("setrlimit failed: %.100s", strerror(errno));
273 pw = getpwuid(original_real_uid);
275 log("You don't exist, go away!");
278 /* Take a copy of the returned structure. */
282 * Use uid-swapping to give up root privileges for the duration of
283 * option processing. We will re-instantiate the rights when we are
284 * ready to create the privileged port, and will permanently drop
285 * them when the port has been created (actually, when the connection
286 * has been made, as we may need to create the port several times).
288 temporarily_use_uid(pw);
291 * Set our umask to something reasonable, as some files are created
292 * with the default umask. This will make them world-readable but
293 * writable only by the owner, which is ok for all files for which we
294 * don't set the modes explicitly.
298 /* Initialize option structure to indicate that no values have been set. */
299 initialize_options(&options);
301 /* Parse command-line arguments. */
304 for (optind = 1; optind < ac; optind++) {
305 if (av[optind][0] != '-') {
308 if ((cp = strchr(av[optind], '@'))) {
311 options.user = av[optind];
321 if (strchr("eilcmpLRDo", opt)) { /* options with arguments */
322 optarg = av[optind] + 2;
323 if (strcmp(optarg, "") == 0) {
324 if (optind >= ac - 1)
326 optarg = av[++optind];
335 options.protocol = SSH_PROTO_1;
338 options.protocol = SSH_PROTO_2;
350 fork_after_authentication_flag = 1;
354 options.forward_x11 = 0;
357 options.forward_x11 = 1;
360 options.gateway_ports = 1;
363 options.use_privileged_port = 0;
366 options.forward_agent = 0;
369 options.forward_agent = 1;
373 options.kerberos_tgt_passing = 0;
374 options.afs_token_passing = 0;
378 if (stat(optarg, &st) < 0) {
379 fprintf(stderr, "Warning: Identity file %s does not exist.\n",
383 if (options.num_identity_files >= SSH_MAX_IDENTITY_FILES)
384 fatal("Too many identity files specified (max %d)",
385 SSH_MAX_IDENTITY_FILES);
386 options.identity_files[options.num_identity_files++] = xstrdup(optarg);
394 if (0 == debug_flag) {
396 options.log_level = SYSLOG_LEVEL_DEBUG1;
397 } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
401 fatal("Too high debugging level.");
406 "%s, SSH protocols %d.%d/%d.%d, OpenSSL 0x%8.8lx\n",
408 PROTOCOL_MAJOR_1, PROTOCOL_MINOR_1,
409 PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2,
415 options.log_level = SYSLOG_LEVEL_QUIET;
418 if (optarg[0] == '^' && optarg[2] == 0 &&
419 (u_char) optarg[1] >= 64 && (u_char) optarg[1] < 128)
420 options.escape_char = (u_char) optarg[1] & 31;
421 else if (strlen(optarg) == 1)
422 options.escape_char = (u_char) optarg[0];
423 else if (strcmp(optarg, "none") == 0)
424 options.escape_char = -2;
426 fprintf(stderr, "Bad escape character '%s'.\n", optarg);
431 if (ciphers_valid(optarg)) {
433 options.ciphers = xstrdup(optarg);
434 options.cipher = SSH_CIPHER_ILLEGAL;
437 options.cipher = cipher_number(optarg);
438 if (options.cipher == -1) {
439 fprintf(stderr, "Unknown cipher type '%s'\n", optarg);
442 if (options.cipher == SSH_CIPHER_3DES) {
443 options.ciphers = "3des-cbc";
444 } else if (options.cipher == SSH_CIPHER_BLOWFISH) {
445 options.ciphers = "blowfish-cbc";
447 options.ciphers = (char *)-1;
452 if (mac_valid(optarg))
453 options.macs = xstrdup(optarg);
455 fprintf(stderr, "Unknown mac type '%s'\n", optarg);
460 options.port = a2port(optarg);
461 if (options.port == 0) {
462 fprintf(stderr, "Bad port '%s'\n", optarg);
467 options.user = optarg;
470 if (sscanf(optarg, "%hu/%255[^/]/%hu", &fwd_port, buf,
471 &fwd_host_port) != 3 &&
472 sscanf(optarg, "%hu:%255[^:]:%hu", &fwd_port, buf,
473 &fwd_host_port) != 3) {
474 fprintf(stderr, "Bad forwarding specification '%s'.\n", optarg);
478 add_remote_forward(&options, fwd_port, buf, fwd_host_port);
481 if (sscanf(optarg, "%hu/%255[^/]/%hu", &fwd_port, buf,
482 &fwd_host_port) != 3 &&
483 sscanf(optarg, "%hu:%255[^:]:%hu", &fwd_port, buf,
484 &fwd_host_port) != 3) {
485 fprintf(stderr, "Bad forwarding specification '%s'.\n", optarg);
489 add_local_forward(&options, fwd_port, buf, fwd_host_port);
493 fwd_port = a2port(optarg);
495 fprintf(stderr, "Bad dynamic port '%s'\n", optarg);
498 add_local_forward(&options, fwd_port, "socks4", 0);
502 options.compression = 1;
513 if (process_config_line(&options, host ? host : "", optarg,
514 "command-line", 0, &dummy) != 0)
525 /* Check that we got a host name. */
529 SSLeay_add_all_algorithms();
530 ERR_load_crypto_strings();
532 /* Initialize the command to execute on remote host. */
533 buffer_init(&command);
536 * Save the command to execute on the remote host in a buffer. There
537 * is no limit on the length of the command, except by the maximum
538 * packet size. Also sets the tty flag if there is no command.
541 /* No command specified - execute shell on a tty. */
543 if (subsystem_flag) {
544 fprintf(stderr, "You must specify a subsystem to invoke.\n");
548 /* A command has been specified. Store it into the
550 for (i = optind; i < ac; i++) {
552 buffer_append(&command, " ", 1);
553 buffer_append(&command, av[i], strlen(av[i]));
557 /* Cannot fork to background if no command. */
558 if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag)
559 fatal("Cannot fork into background without a command to execute.");
561 /* Allocate a tty by default if no command specified. */
562 if (buffer_len(&command) == 0)
568 /* Do not allocate a tty if stdin is not a tty. */
569 if (!isatty(fileno(stdin)) && !force_tty_flag) {
571 log("Pseudo-terminal will not be allocated because stdin is not a terminal.");
576 * Initialize "log" output. Since we are the client all output
577 * actually goes to stderr.
579 log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
580 SYSLOG_FACILITY_USER, 1);
582 /* Read per-user configuration file. */
583 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, _PATH_SSH_USER_CONFFILE);
584 read_config_file(buf, host, &options);
586 /* Read systemwide configuration file. */
587 read_config_file(_PATH_HOST_CONFIG_FILE, host, &options);
589 /* Fill configuration defaults. */
590 fill_default_options(&options);
593 log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1);
597 if (options.user == NULL)
598 options.user = xstrdup(pw->pw_name);
600 if (options.hostname != NULL)
601 host = options.hostname;
603 /* Disable rhosts authentication if not running as root. */
605 /* Ignore uid if running under Windows */
606 if (!options.use_privileged_port) {
608 if (original_effective_uid != 0 || !options.use_privileged_port) {
610 debug("Rhosts Authentication disabled, "
611 "originating port will not be trusted.");
612 options.rhosts_authentication = 0;
616 * If using rsh has been selected, exec it now (without trying
617 * anything else). Note that we must release privileges first.
619 if (options.use_rsh) {
621 * Restore our superuser privileges. This must be done
622 * before permanently setting the uid.
626 /* Switch to the original uid permanently. */
627 permanently_set_uid(pw);
630 rsh_connect(host, options.user, &command);
631 fatal("rsh_connect returned");
633 /* Restore our superuser privileges. */
636 /* Open a connection to the remote host. */
638 ok = ssh_connect(host, &hostaddr, options.port,
639 options.connection_attempts,
640 original_effective_uid != 0 || !options.use_privileged_port,
641 pw, options.proxy_command);
644 * If we successfully made the connection, load the host private key
645 * in case we will need it later for combined rsa-rhosts
646 * authentication. This must be done before releasing extra
647 * privileges, because the file is only readable by root.
649 sensitive_data.nkeys = 0;
650 sensitive_data.keys = NULL;
651 if (ok && (options.rhosts_rsa_authentication ||
652 options.hostbased_authentication)) {
653 sensitive_data.nkeys = 3;
654 sensitive_data.keys = xmalloc(sensitive_data.nkeys*sizeof(Key));
655 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
656 _PATH_HOST_KEY_FILE, "", NULL);
657 sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
658 _PATH_HOST_DSA_KEY_FILE, "", NULL);
659 sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
660 _PATH_HOST_RSA_KEY_FILE, "", NULL);
663 * Get rid of any extra privileges that we may have. We will no
664 * longer need them. Also, extra privileges could make it very hard
665 * to read identity files and other non-world-readable files from the
666 * user's home directory if it happens to be on a NFS volume where
667 * root is mapped to nobody.
671 * Note that some legacy systems need to postpone the following call
672 * to permanently_set_uid() until the private hostkey is destroyed
673 * with RSA_free(). Otherwise the calling user could ptrace() the
674 * process, read the private hostkey and impersonate the host.
675 * OpenBSD does not allow ptracing of setuid processes.
677 permanently_set_uid(pw);
680 * Now that we are back to our own permissions, create ~/.ssh
681 * directory if it doesn\'t already exist.
683 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, _PATH_SSH_USER_DIR);
684 if (stat(buf, &st) < 0)
685 if (mkdir(buf, 0700) < 0)
686 error("Could not create directory '%.200s'.", buf);
688 /* Check if the connection failed, and try "rsh" if appropriate. */
690 if (options.port != 0)
691 log("Secure connection to %.100s on port %hu refused%.100s.",
693 options.fallback_to_rsh ? "; reverting to insecure method" : "");
695 log("Secure connection to %.100s refused%.100s.", host,
696 options.fallback_to_rsh ? "; reverting to insecure method" : "");
698 if (options.fallback_to_rsh) {
699 rsh_connect(host, options.user, &command);
700 fatal("rsh_connect returned");
704 /* load options.identity_files */
705 load_public_identity_files();
707 /* Expand ~ in known host file names. */
709 options.system_hostfile =
710 tilde_expand_filename(options.system_hostfile, original_real_uid);
711 options.user_hostfile =
712 tilde_expand_filename(options.user_hostfile, original_real_uid);
713 options.system_hostfile2 =
714 tilde_expand_filename(options.system_hostfile2, original_real_uid);
715 options.user_hostfile2 =
716 tilde_expand_filename(options.user_hostfile2, original_real_uid);
718 /* Log into the remote system. This never returns if the login fails. */
719 ssh_login(sensitive_data.keys, sensitive_data.nkeys,
720 host, (struct sockaddr *)&hostaddr, pw);
722 /* We no longer need the private host keys. Clear them now. */
723 if (sensitive_data.nkeys != 0) {
724 for (i = 0; i < sensitive_data.nkeys; i++) {
725 if (sensitive_data.keys[i] != NULL) {
726 /* Destroys contents safely */
727 debug3("clear hostkey %d", i);
728 key_free(sensitive_data.keys[i]);
729 sensitive_data.keys[i] = NULL;
732 xfree(sensitive_data.keys);
735 exit_status = compat20 ? ssh_session2() : ssh_session();
741 x11_get_proto(char *proto, int proto_len, char *data, int data_len)
747 if (options.xauth_location) {
748 /* Try to get Xauthority information for the display. */
749 snprintf(line, sizeof line, "%.100s list %.200s 2>" _PATH_DEVNULL,
750 options.xauth_location, getenv("DISPLAY"));
751 f = popen(line, "r");
752 if (f && fgets(line, sizeof(line), f) &&
753 sscanf(line, "%*s %s %s", proto, data) == 2)
759 * If we didn't get authentication data, just make up some
760 * data. The forwarding code will check the validity of the
761 * response anyway, and substitute this data. The X11
762 * server, however, will ignore this fake data and use
763 * whatever authentication mechanisms it was using otherwise
764 * for the local connection.
769 strlcpy(proto, "MIT-MAGIC-COOKIE-1", proto_len);
770 for (i = 0; i < 16; i++) {
773 snprintf(data + 2 * i, data_len - 2 * i, "%02x", rand & 0xff);
780 ssh_init_forwarding(void)
785 /* Initiate local TCP/IP port forwardings. */
786 for (i = 0; i < options.num_local_forwards; i++) {
787 debug("Connections to local port %d forwarded to remote address %.200s:%d",
788 options.local_forwards[i].port,
789 options.local_forwards[i].host,
790 options.local_forwards[i].host_port);
791 success += channel_request_local_forwarding(
792 options.local_forwards[i].port,
793 options.local_forwards[i].host,
794 options.local_forwards[i].host_port,
795 options.gateway_ports);
797 if (i > 0 && success == 0)
798 error("Could not request local forwarding.");
800 /* Initiate remote TCP/IP port forwardings. */
801 for (i = 0; i < options.num_remote_forwards; i++) {
802 debug("Connections to remote port %d forwarded to local address %.200s:%d",
803 options.remote_forwards[i].port,
804 options.remote_forwards[i].host,
805 options.remote_forwards[i].host_port);
806 channel_request_remote_forwarding(
807 options.remote_forwards[i].port,
808 options.remote_forwards[i].host,
809 options.remote_forwards[i].host_port);
814 check_agent_present(void)
816 if (options.forward_agent) {
817 /* Clear agent forwarding if we don\'t have an agent. */
818 int authfd = ssh_get_authentication_socket();
820 options.forward_agent = 0;
822 ssh_close_authentication_socket(authfd);
836 /* Enable compression if requested. */
837 if (options.compression) {
838 debug("Requesting compression at level %d.", options.compression_level);
840 if (options.compression_level < 1 || options.compression_level > 9)
841 fatal("Compression level must be from 1 (fast) to 9 (slow, best).");
843 /* Send the request. */
844 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
845 packet_put_int(options.compression_level);
848 type = packet_read(&plen);
849 if (type == SSH_SMSG_SUCCESS)
850 packet_start_compression(options.compression_level);
851 else if (type == SSH_SMSG_FAILURE)
852 log("Warning: Remote host refused compression.");
854 packet_disconnect("Protocol error waiting for compression response.");
856 /* Allocate a pseudo tty if appropriate. */
858 debug("Requesting pty.");
860 /* Start the packet. */
861 packet_start(SSH_CMSG_REQUEST_PTY);
863 /* Store TERM in the packet. There is no limit on the
864 length of the string. */
868 packet_put_string(cp, strlen(cp));
870 /* Store window size in the packet. */
871 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
872 memset(&ws, 0, sizeof(ws));
873 packet_put_int(ws.ws_row);
874 packet_put_int(ws.ws_col);
875 packet_put_int(ws.ws_xpixel);
876 packet_put_int(ws.ws_ypixel);
878 /* Store tty modes in the packet. */
879 tty_make_modes(fileno(stdin), NULL);
881 /* Send the packet, and wait for it to leave. */
885 /* Read response from the server. */
886 type = packet_read(&plen);
887 if (type == SSH_SMSG_SUCCESS) {
890 } else if (type == SSH_SMSG_FAILURE)
891 log("Warning: Remote host failed or refused to allocate a pseudo tty.");
893 packet_disconnect("Protocol error waiting for pty request response.");
895 /* Request X11 forwarding if enabled and DISPLAY is set. */
896 if (options.forward_x11 && getenv("DISPLAY") != NULL) {
897 char proto[512], data[512];
898 /* Get reasonable local authentication information. */
899 x11_get_proto(proto, sizeof proto, data, sizeof data);
900 /* Request forwarding with authentication spoofing. */
901 debug("Requesting X11 forwarding with authentication spoofing.");
902 x11_request_forwarding_with_spoofing(0, proto, data);
904 /* Read response from the server. */
905 type = packet_read(&plen);
906 if (type == SSH_SMSG_SUCCESS) {
908 } else if (type == SSH_SMSG_FAILURE) {
909 log("Warning: Remote host denied X11 forwarding.");
911 packet_disconnect("Protocol error waiting for X11 forwarding");
914 /* Tell the packet module whether this is an interactive session. */
915 packet_set_interactive(interactive);
917 /* Request authentication agent forwarding if appropriate. */
918 check_agent_present();
920 if (options.forward_agent) {
921 debug("Requesting authentication agent forwarding.");
922 auth_request_forwarding();
924 /* Read response from the server. */
925 type = packet_read(&plen);
926 packet_integrity_check(plen, 0, type);
927 if (type != SSH_SMSG_SUCCESS)
928 log("Warning: Remote host denied authentication agent forwarding.");
931 /* Initiate port forwardings. */
932 ssh_init_forwarding();
934 /* If requested, let ssh continue in the background. */
935 if (fork_after_authentication_flag)
936 if (daemon(1, 1) < 0)
937 fatal("daemon() failed: %.200s", strerror(errno));
940 * If a command was specified on the command line, execute the
941 * command now. Otherwise request the server to start a shell.
943 if (buffer_len(&command) > 0) {
944 int len = buffer_len(&command);
947 debug("Sending command: %.*s", len, buffer_ptr(&command));
948 packet_start(SSH_CMSG_EXEC_CMD);
949 packet_put_string(buffer_ptr(&command), buffer_len(&command));
953 debug("Requesting shell.");
954 packet_start(SSH_CMSG_EXEC_SHELL);
959 /* Enter the interactive session. */
960 return client_loop(have_tty, tty_flag ? options.escape_char : -1, 0);
964 client_subsystem_reply(int type, int plen, void *ctxt)
968 id = packet_get_int();
969 len = buffer_len(&command);
973 if (type == SSH2_MSG_CHANNEL_FAILURE)
974 fatal("Request for subsystem '%.*s' failed on channel %d",
975 len, buffer_ptr(&command), id);
979 ssh_session2_callback(int id, void *arg)
985 debug("client_init id %d arg %ld", id, (long)arg);
993 /* Store window size in the packet. */
994 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
995 memset(&ws, 0, sizeof(ws));
997 channel_request_start(id, "pty-req", 0);
998 packet_put_cstring(cp);
999 packet_put_int(ws.ws_col);
1000 packet_put_int(ws.ws_row);
1001 packet_put_int(ws.ws_xpixel);
1002 packet_put_int(ws.ws_ypixel);
1003 tio = get_saved_tio();
1004 tty_make_modes(/*ignored*/ 0, &tio);
1007 /* XXX wait for reply */
1009 if (options.forward_x11 &&
1010 getenv("DISPLAY") != NULL) {
1011 char proto[512], data[512];
1012 /* Get reasonable local authentication information. */
1013 x11_get_proto(proto, sizeof proto, data, sizeof data);
1014 /* Request forwarding with authentication spoofing. */
1015 debug("Requesting X11 forwarding with authentication spoofing.");
1016 x11_request_forwarding_with_spoofing(id, proto, data);
1018 /* XXX wait for reply */
1021 check_agent_present();
1022 if (options.forward_agent) {
1023 debug("Requesting authentication agent forwarding.");
1024 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1028 len = buffer_len(&command);
1032 if (subsystem_flag) {
1033 debug("Sending subsystem: %.*s", len, buffer_ptr(&command));
1034 channel_request_start(id, "subsystem", /*want reply*/ 1);
1035 /* register callback for reply */
1036 /* XXX we asume that client_loop has already been called */
1037 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &client_subsystem_reply);
1038 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &client_subsystem_reply);
1040 debug("Sending command: %.*s", len, buffer_ptr(&command));
1041 channel_request_start(id, "exec", 0);
1043 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1046 channel_request(id, "shell", 0);
1048 /* channel_callback(id, SSH2_MSG_OPEN_CONFIGMATION, client_init, 0); */
1050 /* register different callback, etc. XXX */
1051 packet_set_interactive(interactive);
1055 ssh_session2_command(void)
1057 int id, window, packetmax;
1060 if (stdin_null_flag) {
1061 in = open(_PATH_DEVNULL, O_RDONLY);
1063 in = dup(STDIN_FILENO);
1065 out = dup(STDOUT_FILENO);
1066 err = dup(STDERR_FILENO);
1068 if (in < 0 || out < 0 || err < 0)
1069 fatal("dup() in/out/err failed");
1071 /* enable nonblocking unless tty */
1079 window = CHAN_SES_WINDOW_DEFAULT;
1080 packetmax = CHAN_SES_PACKET_DEFAULT;
1086 "session", SSH_CHANNEL_OPENING, in, out, err,
1087 window, packetmax, CHAN_EXTENDED_WRITE,
1088 xstrdup("client-session"), /*nonblock*/0);
1090 debug("channel_new: %d", id);
1093 channel_register_callback(id, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION,
1094 ssh_session2_callback, (void *)0);
1104 /* XXX should be pre-session */
1105 ssh_init_forwarding();
1107 id = no_shell_flag ? -1 : ssh_session2_command();
1109 /* If requested, let ssh continue in the background. */
1110 if (fork_after_authentication_flag)
1111 if (daemon(1, 1) < 0)
1112 fatal("daemon() failed: %.200s", strerror(errno));
1114 return client_loop(tty_flag, tty_flag ? options.escape_char : -1, id);
1118 load_public_identity_files(void)
1124 for (i = 0; i < options.num_identity_files; i++) {
1125 filename = tilde_expand_filename(options.identity_files[i],
1127 public = key_load_public(filename, NULL);
1128 debug("identity file %s type %d", filename,
1129 public ? public->type : -1);
1130 xfree(options.identity_files[i]);
1131 options.identity_files[i] = filename;
1132 options.identity_keys[i] = public;