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 1.96 2001/02/17 23:28:58 deraadt 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"
71 #ifdef HAVE___PROGNAME
72 extern char *__progname;
77 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
78 Default value is AF_UNSPEC means both IPv4 and IPv6. */
80 int IPv4or6 = AF_INET;
82 int IPv4or6 = AF_UNSPEC;
85 /* Flag indicating whether debug mode is on. This can be set on the command line. */
88 /* Flag indicating whether a tty should be allocated */
91 int force_tty_flag = 0;
93 /* don't exec a shell */
94 int no_shell_flag = 0;
97 * Flag indicating that nothing should be read from stdin. This can be set
98 * on the command line.
100 int stdin_null_flag = 0;
103 * Flag indicating that ssh should fork after authentication. This is useful
104 * so that the pasphrase can be entered manually, and then ssh goes to the
107 int fork_after_authentication_flag = 0;
110 * General data structure for command line options and options configurable
111 * in configuration files. See readconf.h.
116 * Name of the host we are connecting to. This is the name given on the
117 * command line, or the HostName specified for the user-supplied name in a
118 * configuration file.
122 /* socket address the host resolves to */
123 struct sockaddr_storage hostaddr;
126 * Flag to indicate that we have received a window change signal which has
127 * not yet been processed. This will cause a message indicating the new
128 * window size to be sent to the server a little later. This is volatile
129 * because this is updated in a signal handler.
131 volatile int received_window_change_signal = 0;
133 /* Flag indicating whether we have a valid host private key loaded. */
134 int host_private_key_loaded = 0;
136 /* Host private key. */
137 RSA *host_private_key = NULL;
139 /* Original real UID. */
140 uid_t original_real_uid;
142 /* command to be executed */
145 /* Should we execute a command or invoke a subsystem? */
146 int subsystem_flag = 0;
148 /* Prints a help message to the user. This function never returns. */
153 fprintf(stderr, "Usage: %s [options] host [command]\n", __progname);
154 fprintf(stderr, "Options:\n");
155 fprintf(stderr, " -l user Log in using this user name.\n");
156 fprintf(stderr, " -n Redirect input from " _PATH_DEVNULL ".\n");
157 fprintf(stderr, " -A Enable authentication agent forwarding.\n");
158 fprintf(stderr, " -a Disable authentication agent forwarding.\n");
160 fprintf(stderr, " -k Disable Kerberos ticket and AFS token forwarding.\n");
162 fprintf(stderr, " -X Enable X11 connection forwarding.\n");
163 fprintf(stderr, " -x Disable X11 connection forwarding.\n");
164 fprintf(stderr, " -i file Identity for RSA authentication (default: ~/.ssh/identity).\n");
165 fprintf(stderr, " -t Tty; allocate a tty even if command is given.\n");
166 fprintf(stderr, " -T Do not allocate a tty.\n");
167 fprintf(stderr, " -v Verbose; display verbose debugging messages.\n");
168 fprintf(stderr, " Multiple -v increases verbosity.\n");
169 fprintf(stderr, " -V Display version number only.\n");
170 fprintf(stderr, " -P Don't allocate a privileged port.\n");
171 fprintf(stderr, " -q Quiet; don't display any warning messages.\n");
172 fprintf(stderr, " -f Fork into background after authentication.\n");
173 fprintf(stderr, " -e char Set escape character; ``none'' = disable (default: ~).\n");
175 fprintf(stderr, " -c cipher Select encryption algorithm: "
178 fprintf(stderr, " -p port Connect to this port. Server must be on the same port.\n");
179 fprintf(stderr, " -L listen-port:host:port Forward local port to remote address\n");
180 fprintf(stderr, " -R listen-port:host:port Forward remote port to local address\n");
181 fprintf(stderr, " These cause %s to listen for connections on a port, and\n", __progname);
182 fprintf(stderr, " forward them to the other side by connecting to host:port.\n");
183 fprintf(stderr, " -C Enable compression.\n");
184 fprintf(stderr, " -N Do not execute a shell or command.\n");
185 fprintf(stderr, " -g Allow remote hosts to connect to forwarded ports.\n");
186 fprintf(stderr, " -1 Force protocol version 1.\n");
187 fprintf(stderr, " -2 Force protocol version 2.\n");
188 fprintf(stderr, " -4 Use IPv4 only.\n");
189 fprintf(stderr, " -6 Use IPv6 only.\n");
190 fprintf(stderr, " -o 'option' Process the option as if it was read from a configuration file.\n");
191 fprintf(stderr, " -s Invoke command (mandatory) as SSH2 subsystem.\n");
196 * Connects to the given host using rsh (or prints an error message and exits
197 * if rsh is not available). This function never returns.
200 rsh_connect(char *host, char *user, Buffer * command)
205 log("Using rsh. WARNING: Connection will not be encrypted.");
206 /* Build argument list for rsh. */
208 args[i++] = _PATH_RSH;
209 /* host may have to come after user on some systems */
215 if (buffer_len(command) > 0) {
216 buffer_append(command, "\0", 1);
217 args[i++] = buffer_ptr(command);
221 for (i = 0; args[i]; i++) {
223 fprintf(stderr, " ");
224 fprintf(stderr, "%s", args[i]);
226 fprintf(stderr, "\n");
228 execv(_PATH_RSH, args);
233 int ssh_session(void);
234 int ssh_session2(void);
235 int guess_identity_file_type(const char *filename);
238 * Main program for the ssh client.
241 main(int ac, char **av)
243 int i, opt, optind, exit_status, ok;
244 u_short fwd_port, fwd_host_port;
245 char *optarg, *cp, buf[256];
247 struct passwd *pw, pwcopy;
249 uid_t original_effective_uid;
251 __progname = get_progname(av[0]);
255 * Save the original real uid. It will be needed later (uid-swapping
256 * may clobber the real uid).
258 original_real_uid = getuid();
259 original_effective_uid = geteuid();
261 #ifdef HAVE_SETRLIMIT
262 /* If we are installed setuid root be careful to not drop core. */
263 if (original_real_uid != original_effective_uid) {
265 rlim.rlim_cur = rlim.rlim_max = 0;
266 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
267 fatal("setrlimit failed: %.100s", strerror(errno));
271 * Use uid-swapping to give up root privileges for the duration of
272 * option processing. We will re-instantiate the rights when we are
273 * ready to create the privileged port, and will permanently drop
274 * them when the port has been created (actually, when the connection
275 * has been made, as we may need to create the port several times).
277 temporarily_use_uid(original_real_uid);
280 * Set our umask to something reasonable, as some files are created
281 * with the default umask. This will make them world-readable but
282 * writable only by the owner, which is ok for all files for which we
283 * don't set the modes explicitly.
287 /* Initialize option structure to indicate that no values have been set. */
288 initialize_options(&options);
290 /* Parse command-line arguments. */
293 for (optind = 1; optind < ac; optind++) {
294 if (av[optind][0] != '-') {
297 if ((cp = strchr(av[optind], '@'))) {
300 options.user = av[optind];
310 if (strchr("eilcmpLRo", opt)) { /* options with arguments */
311 optarg = av[optind] + 2;
312 if (strcmp(optarg, "") == 0) {
313 if (optind >= ac - 1)
315 optarg = av[++optind];
324 options.protocol = SSH_PROTO_1;
327 options.protocol = SSH_PROTO_2;
339 fork_after_authentication_flag = 1;
343 options.forward_x11 = 0;
346 options.forward_x11 = 1;
349 options.gateway_ports = 1;
352 options.use_privileged_port = 0;
355 options.forward_agent = 0;
358 options.forward_agent = 1;
362 options.kerberos_tgt_passing = 0;
363 options.afs_token_passing = 0;
367 if (stat(optarg, &st) < 0) {
368 fprintf(stderr, "Warning: Identity file %s does not exist.\n",
372 if (options.num_identity_files >= SSH_MAX_IDENTITY_FILES)
373 fatal("Too many identity files specified (max %d)",
374 SSH_MAX_IDENTITY_FILES);
375 options.identity_files[options.num_identity_files++] = xstrdup(optarg);
383 if (0 == debug_flag) {
385 options.log_level = SYSLOG_LEVEL_DEBUG1;
386 } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
390 fatal("Too high debugging level.\n");
395 "%s, SSH protocols %d.%d/%d.%d, OpenSSL 0x%8.8lx\n",
397 PROTOCOL_MAJOR_1, PROTOCOL_MINOR_1,
398 PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2,
404 options.log_level = SYSLOG_LEVEL_QUIET;
407 if (optarg[0] == '^' && optarg[2] == 0 &&
408 (u_char) optarg[1] >= 64 && (u_char) optarg[1] < 128)
409 options.escape_char = (u_char) optarg[1] & 31;
410 else if (strlen(optarg) == 1)
411 options.escape_char = (u_char) optarg[0];
412 else if (strcmp(optarg, "none") == 0)
413 options.escape_char = -2;
415 fprintf(stderr, "Bad escape character '%s'.\n", optarg);
420 if (ciphers_valid(optarg)) {
422 options.ciphers = xstrdup(optarg);
423 options.cipher = SSH_CIPHER_ILLEGAL;
426 options.cipher = cipher_number(optarg);
427 if (options.cipher == -1) {
428 fprintf(stderr, "Unknown cipher type '%s'\n", optarg);
431 if (options.cipher == SSH_CIPHER_3DES) {
432 options.ciphers = "3des-cbc";
433 } else if (options.cipher == SSH_CIPHER_BLOWFISH) {
434 options.ciphers = "blowfish-cbc";
436 options.ciphers = (char *)-1;
441 if (mac_valid(optarg))
442 options.macs = xstrdup(optarg);
444 fprintf(stderr, "Unknown mac type '%s'\n", optarg);
449 options.port = atoi(optarg);
452 options.user = optarg;
455 if (sscanf(optarg, "%hu/%255[^/]/%hu", &fwd_port, buf,
456 &fwd_host_port) != 3 &&
457 sscanf(optarg, "%hu:%255[^:]:%hu", &fwd_port, buf,
458 &fwd_host_port) != 3) {
459 fprintf(stderr, "Bad forwarding specification '%s'.\n", optarg);
463 add_remote_forward(&options, fwd_port, buf, fwd_host_port);
466 if (sscanf(optarg, "%hu/%255[^/]/%hu", &fwd_port, buf,
467 &fwd_host_port) != 3 &&
468 sscanf(optarg, "%hu:%255[^:]:%hu", &fwd_port, buf,
469 &fwd_host_port) != 3) {
470 fprintf(stderr, "Bad forwarding specification '%s'.\n", optarg);
474 add_local_forward(&options, fwd_port, buf, fwd_host_port);
477 options.compression = 1;
488 if (process_config_line(&options, host ? host : "", optarg,
489 "command-line", 0, &dummy) != 0)
500 /* Check that we got a host name. */
504 SSLeay_add_all_algorithms();
505 ERR_load_crypto_strings();
507 /* Initialize the command to execute on remote host. */
508 buffer_init(&command);
511 * Save the command to execute on the remote host in a buffer. There
512 * is no limit on the length of the command, except by the maximum
513 * packet size. Also sets the tty flag if there is no command.
516 /* No command specified - execute shell on a tty. */
518 if (subsystem_flag) {
519 fprintf(stderr, "You must specify a subsystem to invoke.");
523 /* A command has been specified. Store it into the
525 for (i = optind; i < ac; i++) {
527 buffer_append(&command, " ", 1);
528 buffer_append(&command, av[i], strlen(av[i]));
532 /* Cannot fork to background if no command. */
533 if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag)
534 fatal("Cannot fork into background without a command to execute.");
536 /* Allocate a tty by default if no command specified. */
537 if (buffer_len(&command) == 0)
543 /* Do not allocate a tty if stdin is not a tty. */
544 if (!isatty(fileno(stdin)) && !force_tty_flag) {
546 log("Pseudo-terminal will not be allocated because stdin is not a terminal.\n");
551 pw = getpwuid(original_real_uid);
553 log("You don't exist, go away!\n");
556 /* Take a copy of the returned structure. */
557 memset(&pwcopy, 0, sizeof(pwcopy));
558 pwcopy.pw_name = xstrdup(pw->pw_name);
559 pwcopy.pw_passwd = xstrdup(pw->pw_passwd);
560 pwcopy.pw_uid = pw->pw_uid;
561 pwcopy.pw_gid = pw->pw_gid;
562 #ifdef HAVE_PW_CLASS_IN_PASSWD
563 pwcopy.pw_class = xstrdup(pw->pw_class);
565 pwcopy.pw_dir = xstrdup(pw->pw_dir);
566 pwcopy.pw_shell = xstrdup(pw->pw_shell);
569 /* Initialize "log" output. Since we are the client all output
570 actually goes to the terminal. */
571 log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 0);
573 /* Read per-user configuration file. */
574 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, _PATH_SSH_USER_CONFFILE);
575 read_config_file(buf, host, &options);
577 /* Read systemwide configuration file. */
578 read_config_file(_PATH_HOST_CONFIG_FILE, host, &options);
580 /* Fill configuration defaults. */
581 fill_default_options(&options);
584 log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 0);
586 if (options.user == NULL)
587 options.user = xstrdup(pw->pw_name);
589 if (options.hostname != NULL)
590 host = options.hostname;
592 /* Disable rhosts authentication if not running as root. */
594 /* Ignore uid if running under Windows */
595 if (!options.use_privileged_port) {
597 if (original_effective_uid != 0 || !options.use_privileged_port) {
599 debug("Rhosts Authentication disabled, "
600 "originating port will not be trusted.");
601 options.rhosts_authentication = 0;
604 * If using rsh has been selected, exec it now (without trying
605 * anything else). Note that we must release privileges first.
607 if (options.use_rsh) {
609 * Restore our superuser privileges. This must be done
610 * before permanently setting the uid.
614 /* Switch to the original uid permanently. */
615 permanently_set_uid(original_real_uid);
618 rsh_connect(host, options.user, &command);
619 fatal("rsh_connect returned");
621 /* Restore our superuser privileges. */
624 /* Open a connection to the remote host. */
626 ok = ssh_connect(host, &hostaddr, options.port,
627 options.connection_attempts,
628 original_effective_uid != 0 || !options.use_privileged_port,
630 options.proxy_command);
633 * If we successfully made the connection, load the host private key
634 * in case we will need it later for combined rsa-rhosts
635 * authentication. This must be done before releasing extra
636 * privileges, because the file is only readable by root.
638 if (ok && (options.protocol & SSH_PROTO_1)) {
640 host_private_key = RSA_new();
642 k.rsa = host_private_key;
643 if (load_private_key(_PATH_HOST_KEY_FILE, "", &k, NULL))
644 host_private_key_loaded = 1;
647 * Get rid of any extra privileges that we may have. We will no
648 * longer need them. Also, extra privileges could make it very hard
649 * to read identity files and other non-world-readable files from the
650 * user's home directory if it happens to be on a NFS volume where
651 * root is mapped to nobody.
655 * Note that some legacy systems need to postpone the following call
656 * to permanently_set_uid() until the private hostkey is destroyed
657 * with RSA_free(). Otherwise the calling user could ptrace() the
658 * process, read the private hostkey and impersonate the host.
659 * OpenBSD does not allow ptracing of setuid processes.
661 permanently_set_uid(original_real_uid);
664 * Now that we are back to our own permissions, create ~/.ssh
665 * directory if it doesn\'t already exist.
667 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, _PATH_SSH_USER_DIR);
668 if (stat(buf, &st) < 0)
669 if (mkdir(buf, 0700) < 0)
670 error("Could not create directory '%.200s'.", buf);
672 /* Check if the connection failed, and try "rsh" if appropriate. */
674 if (options.port != 0)
675 log("Secure connection to %.100s on port %hu refused%.100s.",
677 options.fallback_to_rsh ? "; reverting to insecure method" : "");
679 log("Secure connection to %.100s refused%.100s.", host,
680 options.fallback_to_rsh ? "; reverting to insecure method" : "");
682 if (options.fallback_to_rsh) {
683 rsh_connect(host, options.user, &command);
684 fatal("rsh_connect returned");
688 /* Expand ~ in options.identity_files, known host file names. */
690 for (i = 0; i < options.num_identity_files; i++) {
691 options.identity_files[i] =
692 tilde_expand_filename(options.identity_files[i], original_real_uid);
693 options.identity_files_type[i] = guess_identity_file_type(options.identity_files[i]);
694 debug("identity file %s type %d", options.identity_files[i],
695 options.identity_files_type[i]);
697 options.system_hostfile =
698 tilde_expand_filename(options.system_hostfile, original_real_uid);
699 options.user_hostfile =
700 tilde_expand_filename(options.user_hostfile, original_real_uid);
701 options.system_hostfile2 =
702 tilde_expand_filename(options.system_hostfile2, original_real_uid);
703 options.user_hostfile2 =
704 tilde_expand_filename(options.user_hostfile2, original_real_uid);
706 /* Log into the remote system. This never returns if the login fails. */
707 ssh_login(host_private_key_loaded, host_private_key,
708 host, (struct sockaddr *)&hostaddr, original_real_uid);
710 /* We no longer need the host private key. Clear it now. */
711 if (host_private_key_loaded)
712 RSA_free(host_private_key); /* Destroys contents safely */
714 exit_status = compat20 ? ssh_session2() : ssh_session();
720 x11_get_proto(char *proto, int proto_len, char *data, int data_len)
726 if (options.xauth_location) {
727 /* Try to get Xauthority information for the display. */
728 snprintf(line, sizeof line, "%.100s list %.200s 2>" _PATH_DEVNULL,
729 options.xauth_location, getenv("DISPLAY"));
730 f = popen(line, "r");
731 if (f && fgets(line, sizeof(line), f) &&
732 sscanf(line, "%*s %s %s", proto, data) == 2)
738 * If we didn't get authentication data, just make up some
739 * data. The forwarding code will check the validity of the
740 * response anyway, and substitute this data. The X11
741 * server, however, will ignore this fake data and use
742 * whatever authentication mechanisms it was using otherwise
743 * for the local connection.
748 strlcpy(proto, "MIT-MAGIC-COOKIE-1", proto_len);
749 for (i = 0; i < 16; i++) {
752 snprintf(data + 2 * i, data_len - 2 * i, "%02x", rand & 0xff);
759 ssh_init_forwarding(void)
764 /* Initiate local TCP/IP port forwardings. */
765 for (i = 0; i < options.num_local_forwards; i++) {
766 debug("Connections to local port %d forwarded to remote address %.200s:%d",
767 options.local_forwards[i].port,
768 options.local_forwards[i].host,
769 options.local_forwards[i].host_port);
770 success += channel_request_local_forwarding(
771 options.local_forwards[i].port,
772 options.local_forwards[i].host,
773 options.local_forwards[i].host_port,
774 options.gateway_ports);
776 if (i > 0 && success == 0)
777 error("Could not request local forwarding.");
779 /* Initiate remote TCP/IP port forwardings. */
780 for (i = 0; i < options.num_remote_forwards; i++) {
781 debug("Connections to remote port %d forwarded to local address %.200s:%d",
782 options.remote_forwards[i].port,
783 options.remote_forwards[i].host,
784 options.remote_forwards[i].host_port);
785 channel_request_remote_forwarding(
786 options.remote_forwards[i].port,
787 options.remote_forwards[i].host,
788 options.remote_forwards[i].host_port);
793 check_agent_present(void)
795 if (options.forward_agent) {
796 /* Clear agent forwarding if we don\'t have an agent. */
797 int authfd = ssh_get_authentication_socket();
799 options.forward_agent = 0;
801 ssh_close_authentication_socket(authfd);
815 /* Enable compression if requested. */
816 if (options.compression) {
817 debug("Requesting compression at level %d.", options.compression_level);
819 if (options.compression_level < 1 || options.compression_level > 9)
820 fatal("Compression level must be from 1 (fast) to 9 (slow, best).");
822 /* Send the request. */
823 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
824 packet_put_int(options.compression_level);
827 type = packet_read(&plen);
828 if (type == SSH_SMSG_SUCCESS)
829 packet_start_compression(options.compression_level);
830 else if (type == SSH_SMSG_FAILURE)
831 log("Warning: Remote host refused compression.");
833 packet_disconnect("Protocol error waiting for compression response.");
835 /* Allocate a pseudo tty if appropriate. */
837 debug("Requesting pty.");
839 /* Start the packet. */
840 packet_start(SSH_CMSG_REQUEST_PTY);
842 /* Store TERM in the packet. There is no limit on the
843 length of the string. */
847 packet_put_string(cp, strlen(cp));
849 /* Store window size in the packet. */
850 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
851 memset(&ws, 0, sizeof(ws));
852 packet_put_int(ws.ws_row);
853 packet_put_int(ws.ws_col);
854 packet_put_int(ws.ws_xpixel);
855 packet_put_int(ws.ws_ypixel);
857 /* Store tty modes in the packet. */
858 tty_make_modes(fileno(stdin));
860 /* Send the packet, and wait for it to leave. */
864 /* Read response from the server. */
865 type = packet_read(&plen);
866 if (type == SSH_SMSG_SUCCESS) {
869 } else if (type == SSH_SMSG_FAILURE)
870 log("Warning: Remote host failed or refused to allocate a pseudo tty.");
872 packet_disconnect("Protocol error waiting for pty request response.");
874 /* Request X11 forwarding if enabled and DISPLAY is set. */
875 if (options.forward_x11 && getenv("DISPLAY") != NULL) {
876 char proto[512], data[512];
877 /* Get reasonable local authentication information. */
878 x11_get_proto(proto, sizeof proto, data, sizeof data);
879 /* Request forwarding with authentication spoofing. */
880 debug("Requesting X11 forwarding with authentication spoofing.");
881 x11_request_forwarding_with_spoofing(0, proto, data);
883 /* Read response from the server. */
884 type = packet_read(&plen);
885 if (type == SSH_SMSG_SUCCESS) {
887 } else if (type == SSH_SMSG_FAILURE) {
888 log("Warning: Remote host denied X11 forwarding.");
890 packet_disconnect("Protocol error waiting for X11 forwarding");
893 /* Tell the packet module whether this is an interactive session. */
894 packet_set_interactive(interactive);
896 /* Request authentication agent forwarding if appropriate. */
897 check_agent_present();
899 if (options.forward_agent) {
900 debug("Requesting authentication agent forwarding.");
901 auth_request_forwarding();
903 /* Read response from the server. */
904 type = packet_read(&plen);
905 packet_integrity_check(plen, 0, type);
906 if (type != SSH_SMSG_SUCCESS)
907 log("Warning: Remote host denied authentication agent forwarding.");
910 /* Initiate port forwardings. */
911 ssh_init_forwarding();
913 /* If requested, let ssh continue in the background. */
914 if (fork_after_authentication_flag)
915 if (daemon(1, 1) < 0)
916 fatal("daemon() failed: %.200s", strerror(errno));
919 * If a command was specified on the command line, execute the
920 * command now. Otherwise request the server to start a shell.
922 if (buffer_len(&command) > 0) {
923 int len = buffer_len(&command);
926 debug("Sending command: %.*s", len, buffer_ptr(&command));
927 packet_start(SSH_CMSG_EXEC_CMD);
928 packet_put_string(buffer_ptr(&command), buffer_len(&command));
932 debug("Requesting shell.");
933 packet_start(SSH_CMSG_EXEC_SHELL);
938 /* Enter the interactive session. */
939 return client_loop(have_tty, tty_flag ? options.escape_char : -1, 0);
943 client_subsystem_reply(int type, int plen, void *ctxt)
947 id = packet_get_int();
948 len = buffer_len(&command);
951 if (type == SSH2_MSG_CHANNEL_FAILURE)
952 fatal("Request for subsystem '%.*s' failed on channel %d",
953 len, buffer_ptr(&command), id);
957 ssh_session2_callback(int id, void *arg)
962 debug("client_init id %d arg %ld", id, (long)arg);
973 /* Store window size in the packet. */
974 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
975 memset(&ws, 0, sizeof(ws));
977 channel_request_start(id, "pty-req", 0);
978 packet_put_cstring(cp);
979 packet_put_int(ws.ws_col);
980 packet_put_int(ws.ws_row);
981 packet_put_int(ws.ws_xpixel);
982 packet_put_int(ws.ws_ypixel);
983 packet_put_cstring(""); /* XXX: encode terminal modes */
986 /* XXX wait for reply */
988 if (options.forward_x11 &&
989 getenv("DISPLAY") != NULL) {
990 char proto[512], data[512];
991 /* Get reasonable local authentication information. */
992 x11_get_proto(proto, sizeof proto, data, sizeof data);
993 /* Request forwarding with authentication spoofing. */
994 debug("Requesting X11 forwarding with authentication spoofing.");
995 x11_request_forwarding_with_spoofing(id, proto, data);
997 /* XXX wait for reply */
1000 check_agent_present();
1001 if (options.forward_agent) {
1002 debug("Requesting authentication agent forwarding.");
1003 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1007 len = buffer_len(&command);
1011 if (subsystem_flag) {
1012 debug("Sending subsystem: %.*s", len, buffer_ptr(&command));
1013 channel_request_start(id, "subsystem", /*want reply*/ 1);
1014 /* register callback for reply */
1015 /* XXX we asume that client_loop has already been called */
1016 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &client_subsystem_reply);
1017 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &client_subsystem_reply);
1019 debug("Sending command: %.*s", len, buffer_ptr(&command));
1020 channel_request_start(id, "exec", 0);
1022 packet_put_string(buffer_ptr(&command), len);
1025 channel_request(id, "shell", 0);
1027 /* channel_callback(id, SSH2_MSG_OPEN_CONFIGMATION, client_init, 0); */
1030 /* register different callback, etc. XXX */
1031 packet_set_interactive(interactive);
1037 int window, packetmax, id;
1040 if (stdin_null_flag) {
1041 in = open(_PATH_DEVNULL, O_RDONLY);
1043 in = dup(STDIN_FILENO);
1045 out = dup(STDOUT_FILENO);
1046 err = dup(STDERR_FILENO);
1048 if (in < 0 || out < 0 || err < 0)
1049 fatal("dup() in/out/err failed");
1051 /* enable nonblocking unless tty */
1059 /* XXX should be pre-session */
1060 ssh_init_forwarding();
1062 /* If requested, let ssh continue in the background. */
1063 if (fork_after_authentication_flag)
1064 if (daemon(1, 1) < 0)
1065 fatal("daemon() failed: %.200s", strerror(errno));
1067 window = CHAN_SES_WINDOW_DEFAULT;
1068 packetmax = CHAN_SES_PACKET_DEFAULT;
1074 "session", SSH_CHANNEL_OPENING, in, out, err,
1075 window, packetmax, CHAN_EXTENDED_WRITE,
1076 xstrdup("client-session"), /*nonblock*/0);
1079 channel_register_callback(id, SSH2_MSG_CHANNEL_OPEN_CONFIRMATION,
1080 ssh_session2_callback, (void *)0);
1082 return client_loop(tty_flag, tty_flag ? options.escape_char : -1, id);
1086 guess_identity_file_type(const char *filename)
1090 int type = KEY_RSA1; /* default */
1092 if (stat(filename, &st) < 0) {
1093 /* ignore this key */
1096 public = key_new(type);
1097 if (!load_public_key(filename, public, NULL)) {
1098 /* ok, so we will assume this is 'some' key */