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.
16 * Copyright (c) 2000, 2001, 2002 Markus Friedl. All rights reserved.
18 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
19 * in Canada (German citizen).
21 * Redistribution and use in source and binary forms, with or without
22 * modification, are permitted provided that the following conditions
24 * 1. Redistributions of source code must retain the above copyright
25 * notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 * notice, this list of conditions and the following disclaimer in the
28 * documentation and/or other materials provided with the distribution.
30 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
43 RCSID("$OpenBSD: ssh.c,v 1.174 2002/05/23 19:39:34 markus Exp $");
45 #include <openssl/evp.h>
46 #include <openssl/err.h>
61 #include "pathnames.h"
62 #include "clientloop.h"
65 #include "sshconnect.h"
66 #include "tildexpand.h"
77 #ifdef HAVE___PROGNAME
78 extern char *__progname;
83 /* Flag indicating whether IPv4 or IPv6. This can be set on the command line.
84 Default value is AF_UNSPEC means both IPv4 and IPv6. */
86 int IPv4or6 = AF_INET;
88 int IPv4or6 = AF_UNSPEC;
91 /* Flag indicating whether debug mode is on. This can be set on the command line. */
94 /* Flag indicating whether a tty should be allocated */
97 int force_tty_flag = 0;
99 /* don't exec a shell */
100 int no_shell_flag = 0;
103 * Flag indicating that nothing should be read from stdin. This can be set
104 * on the command line.
106 int stdin_null_flag = 0;
109 * Flag indicating that ssh should fork after authentication. This is useful
110 * so that the passphrase can be entered manually, and then ssh goes to the
113 int fork_after_authentication_flag = 0;
116 * General data structure for command line options and options configurable
117 * in configuration files. See readconf.h.
121 /* optional user configfile */
125 * Name of the host we are connecting to. This is the name given on the
126 * command line, or the HostName specified for the user-supplied name in a
127 * configuration file.
131 /* socket address the host resolves to */
132 struct sockaddr_storage hostaddr;
134 /* Private host keys. */
135 Sensitive sensitive_data;
137 /* Original real UID. */
138 uid_t original_real_uid;
140 /* command to be executed */
143 /* Should we execute a command or invoke a subsystem? */
144 int subsystem_flag = 0;
146 /* # of replies received for global requests */
147 static int client_global_request_id = 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, " -F config Config file (default: ~/%s).\n",
159 _PATH_SSH_USER_CONFFILE);
160 fprintf(stderr, " -A Enable authentication agent forwarding.\n");
161 fprintf(stderr, " -a Disable authentication agent forwarding (default).\n");
163 fprintf(stderr, " -k Disable Kerberos ticket and AFS token forwarding.\n");
165 fprintf(stderr, " -X Enable X11 connection forwarding.\n");
166 fprintf(stderr, " -x Disable X11 connection forwarding (default).\n");
167 fprintf(stderr, " -i file Identity for public key authentication "
168 "(default: ~/.ssh/identity)\n");
170 fprintf(stderr, " -I reader Set smartcard reader.\n");
172 fprintf(stderr, " -t Tty; allocate a tty even if command is given.\n");
173 fprintf(stderr, " -T Do not allocate a tty.\n");
174 fprintf(stderr, " -v Verbose; display verbose debugging messages.\n");
175 fprintf(stderr, " Multiple -v increases verbosity.\n");
176 fprintf(stderr, " -V Display version number only.\n");
177 fprintf(stderr, " -P Don't allocate a privileged port.\n");
178 fprintf(stderr, " -q Quiet; don't display any warning messages.\n");
179 fprintf(stderr, " -f Fork into background after authentication.\n");
180 fprintf(stderr, " -e char Set escape character; ``none'' = disable (default: ~).\n");
182 fprintf(stderr, " -c cipher Select encryption algorithm\n");
183 fprintf(stderr, " -m macs Specify MAC algorithms for protocol version 2.\n");
184 fprintf(stderr, " -p port Connect to this port. Server must be on the same port.\n");
185 fprintf(stderr, " -L listen-port:host:port Forward local port to remote address\n");
186 fprintf(stderr, " -R listen-port:host:port Forward remote port to local address\n");
187 fprintf(stderr, " These cause %s to listen for connections on a port, and\n", __progname);
188 fprintf(stderr, " forward them to the other side by connecting to host:port.\n");
189 fprintf(stderr, " -D port Enable dynamic application-level port forwarding.\n");
190 fprintf(stderr, " -C Enable compression.\n");
191 fprintf(stderr, " -N Do not execute a shell or command.\n");
192 fprintf(stderr, " -g Allow remote hosts to connect to forwarded ports.\n");
193 fprintf(stderr, " -1 Force protocol version 1.\n");
194 fprintf(stderr, " -2 Force protocol version 2.\n");
195 fprintf(stderr, " -4 Use IPv4 only.\n");
196 fprintf(stderr, " -6 Use IPv6 only.\n");
197 fprintf(stderr, " -o 'option' Process the option as if it was read from a configuration file.\n");
198 fprintf(stderr, " -s Invoke command (mandatory) as SSH2 subsystem.\n");
199 fprintf(stderr, " -b addr Local IP address.\n");
204 * Connects to the given host using rsh (or prints an error message and exits
205 * if rsh is not available). This function never returns.
208 rsh_connect(char *host, char *user, Buffer * command)
213 log("Using rsh. WARNING: Connection will not be encrypted.");
214 /* Build argument list for rsh. */
216 args[i++] = _PATH_RSH;
217 /* host may have to come after user on some systems */
223 if (buffer_len(command) > 0) {
224 buffer_append(command, "\0", 1);
225 args[i++] = buffer_ptr(command);
229 for (i = 0; args[i]; i++) {
231 fprintf(stderr, " ");
232 fprintf(stderr, "%s", args[i]);
234 fprintf(stderr, "\n");
236 execv(_PATH_RSH, args);
241 static int ssh_session(void);
242 static int ssh_session2(void);
243 static void load_public_identity_files(void);
246 * Main program for the ssh client.
249 main(int ac, char **av)
251 int i, opt, exit_status, cerr;
252 u_short fwd_port, fwd_host_port;
253 char sfwd_port[6], sfwd_host_port[6];
254 char *p, *cp, buf[256];
258 uid_t original_effective_uid;
259 extern int optind, optreset;
262 __progname = get_progname(av[0]);
266 * Save the original real uid. It will be needed later (uid-swapping
267 * may clobber the real uid).
269 original_real_uid = getuid();
270 original_effective_uid = geteuid();
272 #ifdef HAVE_SETRLIMIT
273 /* If we are installed setuid root be careful to not drop core. */
274 if (original_real_uid != original_effective_uid) {
276 rlim.rlim_cur = rlim.rlim_max = 0;
277 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
278 fatal("setrlimit failed: %.100s", strerror(errno));
282 pw = getpwuid(original_real_uid);
284 log("You don't exist, go away!");
287 /* Take a copy of the returned structure. */
291 * Use uid-swapping to give up root privileges for the duration of
292 * option processing. We will re-instantiate the rights when we are
293 * ready to create the privileged port, and will permanently drop
294 * them when the port has been created (actually, when the connection
295 * has been made, as we may need to create the port several times).
297 temporarily_use_uid(pw);
300 * Set our umask to something reasonable, as some files are created
301 * with the default umask. This will make them world-readable but
302 * writable only by the owner, which is ok for all files for which we
303 * don't set the modes explicitly.
307 /* Initialize option structure to indicate that no values have been set. */
308 initialize_options(&options);
310 /* Parse command-line arguments. */
314 while ((opt = getopt(ac, av,
315 "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:NPR:TVX")) != -1) {
318 options.protocol = SSH_PROTO_1;
321 options.protocol = SSH_PROTO_2;
333 fork_after_authentication_flag = 1;
337 options.forward_x11 = 0;
340 options.forward_x11 = 1;
343 options.gateway_ports = 1;
346 options.use_privileged_port = 0;
349 options.forward_agent = 0;
352 options.forward_agent = 1;
356 options.kerberos_tgt_passing = 0;
357 options.afs_token_passing = 0;
361 if (stat(optarg, &st) < 0) {
362 fprintf(stderr, "Warning: Identity file %s "
363 "does not exist.\n", optarg);
366 if (options.num_identity_files >=
367 SSH_MAX_IDENTITY_FILES)
368 fatal("Too many identity files specified "
369 "(max %d)", SSH_MAX_IDENTITY_FILES);
370 options.identity_files[options.num_identity_files++] =
375 options.smartcard_device = xstrdup(optarg);
377 fprintf(stderr, "no support for smartcards.\n");
386 if (0 == debug_flag) {
388 options.log_level = SYSLOG_LEVEL_DEBUG1;
389 } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
393 fatal("Too high debugging level.");
397 "%s, SSH protocols %d.%d/%d.%d, OpenSSL 0x%8.8lx\n",
399 PROTOCOL_MAJOR_1, PROTOCOL_MINOR_1,
400 PROTOCOL_MAJOR_2, PROTOCOL_MINOR_2,
406 options.log_level = SYSLOG_LEVEL_QUIET;
409 if (optarg[0] == '^' && optarg[2] == 0 &&
410 (u_char) optarg[1] >= 64 &&
411 (u_char) optarg[1] < 128)
412 options.escape_char = (u_char) optarg[1] & 31;
413 else if (strlen(optarg) == 1)
414 options.escape_char = (u_char) optarg[0];
415 else if (strcmp(optarg, "none") == 0)
416 options.escape_char = SSH_ESCAPECHAR_NONE;
418 fprintf(stderr, "Bad escape character '%s'.\n",
424 if (ciphers_valid(optarg)) {
426 options.ciphers = xstrdup(optarg);
427 options.cipher = SSH_CIPHER_ILLEGAL;
430 options.cipher = cipher_number(optarg);
431 if (options.cipher == -1) {
433 "Unknown cipher type '%s'\n",
437 if (options.cipher == SSH_CIPHER_3DES)
438 options.ciphers = "3des-cbc";
439 else if (options.cipher == SSH_CIPHER_BLOWFISH)
440 options.ciphers = "blowfish-cbc";
442 options.ciphers = (char *)-1;
446 if (mac_valid(optarg))
447 options.macs = xstrdup(optarg);
449 fprintf(stderr, "Unknown mac type '%s'\n",
455 options.port = a2port(optarg);
456 if (options.port == 0) {
457 fprintf(stderr, "Bad port '%s'\n", optarg);
462 options.user = optarg;
467 if (sscanf(optarg, "%5[0-9]:%255[^:]:%5[0-9]",
468 sfwd_port, buf, sfwd_host_port) != 3 &&
469 sscanf(optarg, "%5[0-9]/%255[^/]/%5[0-9]",
470 sfwd_port, buf, sfwd_host_port) != 3) {
472 "Bad forwarding specification '%s'\n",
477 if ((fwd_port = a2port(sfwd_port)) == 0 ||
478 (fwd_host_port = a2port(sfwd_host_port)) == 0) {
480 "Bad forwarding port(s) '%s'\n", optarg);
484 add_local_forward(&options, fwd_port, buf,
487 add_remote_forward(&options, fwd_port, buf,
492 fwd_port = a2port(optarg);
494 fprintf(stderr, "Bad dynamic port '%s'\n",
498 add_local_forward(&options, fwd_port, "socks4", 0);
502 options.compression = 1;
513 if (process_config_line(&options, host ? host : "",
514 optarg, "command-line", 0, &dummy) != 0)
521 options.bind_address = optarg;
534 if (ac > 0 && !host && **av != '-') {
535 if (strchr(*av, '@')) {
538 if (cp == NULL || cp == p)
553 /* Check that we got a host name. */
557 SSLeay_add_all_algorithms();
558 ERR_load_crypto_strings();
559 channel_set_af(IPv4or6);
561 /* Initialize the command to execute on remote host. */
562 buffer_init(&command);
565 * Save the command to execute on the remote host in a buffer. There
566 * is no limit on the length of the command, except by the maximum
567 * packet size. Also sets the tty flag if there is no command.
570 /* No command specified - execute shell on a tty. */
572 if (subsystem_flag) {
574 "You must specify a subsystem to invoke.\n");
578 /* A command has been specified. Store it into the buffer. */
579 for (i = 0; i < ac; i++) {
581 buffer_append(&command, " ", 1);
582 buffer_append(&command, av[i], strlen(av[i]));
586 /* Cannot fork to background if no command. */
587 if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag)
588 fatal("Cannot fork into background without a command to execute.");
590 /* Allocate a tty by default if no command specified. */
591 if (buffer_len(&command) == 0)
597 /* Do not allocate a tty if stdin is not a tty. */
598 if (!isatty(fileno(stdin)) && !force_tty_flag) {
600 log("Pseudo-terminal will not be allocated because stdin is not a terminal.");
605 * Initialize "log" output. Since we are the client all output
606 * actually goes to stderr.
608 log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
609 SYSLOG_FACILITY_USER, 1);
612 * Read per-user configuration file. Ignore the system wide config
613 * file if the user specifies a config file on the command line.
615 if (config != NULL) {
616 if (!read_config_file(config, host, &options))
617 fatal("Can't open user config file %.100s: "
618 "%.100s", config, strerror(errno));
620 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
621 _PATH_SSH_USER_CONFFILE);
622 (void)read_config_file(buf, host, &options);
624 /* Read systemwide configuration file after use config. */
625 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, &options);
628 /* Fill configuration defaults. */
629 fill_default_options(&options);
632 log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1);
636 if (options.user == NULL)
637 options.user = xstrdup(pw->pw_name);
639 if (options.hostname != NULL)
640 host = options.hostname;
642 /* Disable rhosts authentication if not running as root. */
644 /* Ignore uid if running under Windows */
645 if (!options.use_privileged_port) {
647 if (original_effective_uid != 0 || !options.use_privileged_port) {
649 debug("Rhosts Authentication disabled, "
650 "originating port will not be trusted.");
651 options.rhosts_authentication = 0;
654 * If using rsh has been selected, exec it now (without trying
655 * anything else). Note that we must release privileges first.
657 if (options.use_rsh) {
659 * Restore our superuser privileges. This must be done
660 * before permanently setting the uid.
664 /* Switch to the original uid permanently. */
665 permanently_set_uid(pw);
668 rsh_connect(host, options.user, &command);
669 fatal("rsh_connect returned");
671 /* Restore our superuser privileges. */
674 /* Open a connection to the remote host. */
676 cerr = ssh_connect(host, &hostaddr, options.port, IPv4or6,
677 options.connection_attempts,
678 original_effective_uid != 0 || !options.use_privileged_port,
679 pw, options.proxy_command);
682 * If we successfully made the connection, load the host private key
683 * in case we will need it later for combined rsa-rhosts
684 * authentication. This must be done before releasing extra
685 * privileges, because the file is only readable by root.
686 * If we cannot access the private keys, load the public keys
687 * instead and try to execute the ssh-keysign helper instead.
689 sensitive_data.nkeys = 0;
690 sensitive_data.keys = NULL;
691 sensitive_data.external_keysign = 0;
692 if (!cerr && (options.rhosts_rsa_authentication ||
693 options.hostbased_authentication)) {
694 sensitive_data.nkeys = 3;
695 sensitive_data.keys = xmalloc(sensitive_data.nkeys*sizeof(Key));
696 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
697 _PATH_HOST_KEY_FILE, "", NULL);
698 sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
699 _PATH_HOST_DSA_KEY_FILE, "", NULL);
700 sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
701 _PATH_HOST_RSA_KEY_FILE, "", NULL);
703 if (sensitive_data.keys[0] == NULL &&
704 sensitive_data.keys[1] == NULL &&
705 sensitive_data.keys[2] == NULL) {
706 sensitive_data.keys[1] = key_load_public(
707 _PATH_HOST_DSA_KEY_FILE, NULL);
708 sensitive_data.keys[2] = key_load_public(
709 _PATH_HOST_RSA_KEY_FILE, NULL);
710 sensitive_data.external_keysign = 1;
714 * Get rid of any extra privileges that we may have. We will no
715 * longer need them. Also, extra privileges could make it very hard
716 * to read identity files and other non-world-readable files from the
717 * user's home directory if it happens to be on a NFS volume where
718 * root is mapped to nobody.
722 * Note that some legacy systems need to postpone the following call
723 * to permanently_set_uid() until the private hostkey is destroyed
724 * with RSA_free(). Otherwise the calling user could ptrace() the
725 * process, read the private hostkey and impersonate the host.
726 * OpenBSD does not allow ptracing of setuid processes.
728 permanently_set_uid(pw);
731 * Now that we are back to our own permissions, create ~/.ssh
732 * directory if it doesn\'t already exist.
734 snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
735 if (stat(buf, &st) < 0)
736 if (mkdir(buf, 0700) < 0)
737 error("Could not create directory '%.200s'.", buf);
739 /* Check if the connection failed, and try "rsh" if appropriate. */
741 if (!options.fallback_to_rsh)
743 if (options.port != 0)
744 log("Secure connection to %.100s on port %hu refused; "
745 "reverting to insecure method",
748 log("Secure connection to %.100s refused; "
749 "reverting to insecure method.", host);
751 rsh_connect(host, options.user, &command);
752 fatal("rsh_connect returned");
754 /* load options.identity_files */
755 load_public_identity_files();
757 /* Expand ~ in known host file names. */
759 options.system_hostfile =
760 tilde_expand_filename(options.system_hostfile, original_real_uid);
761 options.user_hostfile =
762 tilde_expand_filename(options.user_hostfile, original_real_uid);
763 options.system_hostfile2 =
764 tilde_expand_filename(options.system_hostfile2, original_real_uid);
765 options.user_hostfile2 =
766 tilde_expand_filename(options.user_hostfile2, original_real_uid);
768 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
770 /* Log into the remote system. This never returns if the login fails. */
771 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw);
773 /* We no longer need the private host keys. Clear them now. */
774 if (sensitive_data.nkeys != 0) {
775 for (i = 0; i < sensitive_data.nkeys; i++) {
776 if (sensitive_data.keys[i] != NULL) {
777 /* Destroys contents safely */
778 debug3("clear hostkey %d", i);
779 key_free(sensitive_data.keys[i]);
780 sensitive_data.keys[i] = NULL;
783 xfree(sensitive_data.keys);
785 for (i = 0; i < options.num_identity_files; i++) {
786 if (options.identity_files[i]) {
787 xfree(options.identity_files[i]);
788 options.identity_files[i] = NULL;
790 if (options.identity_keys[i]) {
791 key_free(options.identity_keys[i]);
792 options.identity_keys[i] = NULL;
796 exit_status = compat20 ? ssh_session2() : ssh_session();
802 x11_get_proto(char **_proto, char **_data)
805 static char proto[512], data[512];
812 proto[0] = data[0] = '\0';
813 if (options.xauth_location && (display = getenv("DISPLAY"))) {
814 /* Try to get Xauthority information for the display. */
815 if (strncmp(display, "localhost:", 10) == 0)
817 * Handle FamilyLocal case where $DISPLAY does
818 * not match an authorization entry. For this we
819 * just try "xauth list unix:displaynum.screennum".
820 * XXX: "localhost" match to determine FamilyLocal
823 snprintf(line, sizeof line, "%s list unix:%s 2>"
824 _PATH_DEVNULL, options.xauth_location, display+10);
826 snprintf(line, sizeof line, "%s list %.200s 2>"
827 _PATH_DEVNULL, options.xauth_location, display);
828 debug2("x11_get_proto %s", line);
829 f = popen(line, "r");
830 if (f && fgets(line, sizeof(line), f) &&
831 sscanf(line, "%*s %511s %511s", proto, data) == 2)
837 * If we didn't get authentication data, just make up some
838 * data. The forwarding code will check the validity of the
839 * response anyway, and substitute this data. The X11
840 * server, however, will ignore this fake data and use
841 * whatever authentication mechanisms it was using otherwise
842 * for the local connection.
847 strlcpy(proto, "MIT-MAGIC-COOKIE-1", sizeof proto);
848 for (i = 0; i < 16; i++) {
851 snprintf(data + 2 * i, sizeof data - 2 * i, "%02x", rand & 0xff);
858 ssh_init_forwarding(void)
863 /* Initiate local TCP/IP port forwardings. */
864 for (i = 0; i < options.num_local_forwards; i++) {
865 debug("Connections to local port %d forwarded to remote address %.200s:%d",
866 options.local_forwards[i].port,
867 options.local_forwards[i].host,
868 options.local_forwards[i].host_port);
869 success += channel_setup_local_fwd_listener(
870 options.local_forwards[i].port,
871 options.local_forwards[i].host,
872 options.local_forwards[i].host_port,
873 options.gateway_ports);
875 if (i > 0 && success == 0)
876 error("Could not request local forwarding.");
878 /* Initiate remote TCP/IP port forwardings. */
879 for (i = 0; i < options.num_remote_forwards; i++) {
880 debug("Connections to remote port %d forwarded to local address %.200s:%d",
881 options.remote_forwards[i].port,
882 options.remote_forwards[i].host,
883 options.remote_forwards[i].host_port);
884 channel_request_remote_forwarding(
885 options.remote_forwards[i].port,
886 options.remote_forwards[i].host,
887 options.remote_forwards[i].host_port);
892 check_agent_present(void)
894 if (options.forward_agent) {
895 /* Clear agent forwarding if we don\'t have an agent. */
896 int authfd = ssh_get_authentication_socket();
898 options.forward_agent = 0;
900 ssh_close_authentication_socket(authfd);
913 /* Enable compression if requested. */
914 if (options.compression) {
915 debug("Requesting compression at level %d.", options.compression_level);
917 if (options.compression_level < 1 || options.compression_level > 9)
918 fatal("Compression level must be from 1 (fast) to 9 (slow, best).");
920 /* Send the request. */
921 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
922 packet_put_int(options.compression_level);
925 type = packet_read();
926 if (type == SSH_SMSG_SUCCESS)
927 packet_start_compression(options.compression_level);
928 else if (type == SSH_SMSG_FAILURE)
929 log("Warning: Remote host refused compression.");
931 packet_disconnect("Protocol error waiting for compression response.");
933 /* Allocate a pseudo tty if appropriate. */
935 debug("Requesting pty.");
937 /* Start the packet. */
938 packet_start(SSH_CMSG_REQUEST_PTY);
940 /* Store TERM in the packet. There is no limit on the
941 length of the string. */
945 packet_put_cstring(cp);
947 /* Store window size in the packet. */
948 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
949 memset(&ws, 0, sizeof(ws));
950 packet_put_int(ws.ws_row);
951 packet_put_int(ws.ws_col);
952 packet_put_int(ws.ws_xpixel);
953 packet_put_int(ws.ws_ypixel);
955 /* Store tty modes in the packet. */
956 tty_make_modes(fileno(stdin), NULL);
958 /* Send the packet, and wait for it to leave. */
962 /* Read response from the server. */
963 type = packet_read();
964 if (type == SSH_SMSG_SUCCESS) {
967 } else if (type == SSH_SMSG_FAILURE)
968 log("Warning: Remote host failed or refused to allocate a pseudo tty.");
970 packet_disconnect("Protocol error waiting for pty request response.");
972 /* Request X11 forwarding if enabled and DISPLAY is set. */
973 if (options.forward_x11 && getenv("DISPLAY") != NULL) {
975 /* Get reasonable local authentication information. */
976 x11_get_proto(&proto, &data);
977 /* Request forwarding with authentication spoofing. */
978 debug("Requesting X11 forwarding with authentication spoofing.");
979 x11_request_forwarding_with_spoofing(0, proto, data);
981 /* Read response from the server. */
982 type = packet_read();
983 if (type == SSH_SMSG_SUCCESS) {
985 } else if (type == SSH_SMSG_FAILURE) {
986 log("Warning: Remote host denied X11 forwarding.");
988 packet_disconnect("Protocol error waiting for X11 forwarding");
991 /* Tell the packet module whether this is an interactive session. */
992 packet_set_interactive(interactive);
994 /* Request authentication agent forwarding if appropriate. */
995 check_agent_present();
997 if (options.forward_agent) {
998 debug("Requesting authentication agent forwarding.");
999 auth_request_forwarding();
1001 /* Read response from the server. */
1002 type = packet_read();
1004 if (type != SSH_SMSG_SUCCESS)
1005 log("Warning: Remote host denied authentication agent forwarding.");
1008 /* Initiate port forwardings. */
1009 ssh_init_forwarding();
1011 /* If requested, let ssh continue in the background. */
1012 if (fork_after_authentication_flag)
1013 if (daemon(1, 1) < 0)
1014 fatal("daemon() failed: %.200s", strerror(errno));
1017 * If a command was specified on the command line, execute the
1018 * command now. Otherwise request the server to start a shell.
1020 if (buffer_len(&command) > 0) {
1021 int len = buffer_len(&command);
1024 debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command));
1025 packet_start(SSH_CMSG_EXEC_CMD);
1026 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1028 packet_write_wait();
1030 debug("Requesting shell.");
1031 packet_start(SSH_CMSG_EXEC_SHELL);
1033 packet_write_wait();
1036 /* Enter the interactive session. */
1037 return client_loop(have_tty, tty_flag ?
1038 options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1042 client_subsystem_reply(int type, u_int32_t seq, void *ctxt)
1046 id = packet_get_int();
1047 len = buffer_len(&command);
1051 if (type == SSH2_MSG_CHANNEL_FAILURE)
1052 fatal("Request for subsystem '%.*s' failed on channel %d",
1053 len, (u_char *)buffer_ptr(&command), id);
1057 client_global_request_reply(int type, u_int32_t seq, void *ctxt)
1061 i = client_global_request_id++;
1062 if (i >= options.num_remote_forwards) {
1063 debug("client_global_request_reply: too many replies %d > %d",
1064 i, options.num_remote_forwards);
1067 debug("remote forward %s for: listen %d, connect %s:%d",
1068 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1069 options.remote_forwards[i].port,
1070 options.remote_forwards[i].host,
1071 options.remote_forwards[i].host_port);
1072 if (type == SSH2_MSG_REQUEST_FAILURE)
1073 log("Warning: remote port forwarding failed for listen port %d",
1074 options.remote_forwards[i].port);
1077 /* request pty/x11/agent/tcpfwd/shell for channel */
1079 ssh_session2_setup(int id, void *arg)
1082 int interactive = 0;
1085 debug("ssh_session2_setup: id %d", id);
1090 cp = getenv("TERM");
1093 /* Store window size in the packet. */
1094 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
1095 memset(&ws, 0, sizeof(ws));
1097 channel_request_start(id, "pty-req", 0);
1098 packet_put_cstring(cp);
1099 packet_put_int(ws.ws_col);
1100 packet_put_int(ws.ws_row);
1101 packet_put_int(ws.ws_xpixel);
1102 packet_put_int(ws.ws_ypixel);
1103 tio = get_saved_tio();
1104 tty_make_modes(/*ignored*/ 0, &tio);
1107 /* XXX wait for reply */
1109 if (options.forward_x11 &&
1110 getenv("DISPLAY") != NULL) {
1112 /* Get reasonable local authentication information. */
1113 x11_get_proto(&proto, &data);
1114 /* Request forwarding with authentication spoofing. */
1115 debug("Requesting X11 forwarding with authentication spoofing.");
1116 x11_request_forwarding_with_spoofing(id, proto, data);
1118 /* XXX wait for reply */
1121 check_agent_present();
1122 if (options.forward_agent) {
1123 debug("Requesting authentication agent forwarding.");
1124 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1128 len = buffer_len(&command);
1132 if (subsystem_flag) {
1133 debug("Sending subsystem: %.*s", len, (u_char *)buffer_ptr(&command));
1134 channel_request_start(id, "subsystem", /*want reply*/ 1);
1135 /* register callback for reply */
1136 /* XXX we assume that client_loop has already been called */
1137 dispatch_set(SSH2_MSG_CHANNEL_FAILURE, &client_subsystem_reply);
1138 dispatch_set(SSH2_MSG_CHANNEL_SUCCESS, &client_subsystem_reply);
1140 debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command));
1141 channel_request_start(id, "exec", 0);
1143 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1146 channel_request_start(id, "shell", 0);
1150 packet_set_interactive(interactive);
1153 /* open new channel for a session */
1155 ssh_session2_open(void)
1158 int window, packetmax, in, out, err;
1160 if (stdin_null_flag) {
1161 in = open(_PATH_DEVNULL, O_RDONLY);
1163 in = dup(STDIN_FILENO);
1165 out = dup(STDOUT_FILENO);
1166 err = dup(STDERR_FILENO);
1168 if (in < 0 || out < 0 || err < 0)
1169 fatal("dup() in/out/err failed");
1171 /* enable nonblocking unless tty */
1179 window = CHAN_SES_WINDOW_DEFAULT;
1180 packetmax = CHAN_SES_PACKET_DEFAULT;
1186 "session", SSH_CHANNEL_OPENING, in, out, err,
1187 window, packetmax, CHAN_EXTENDED_WRITE,
1188 xstrdup("client-session"), /*nonblock*/0);
1190 debug3("ssh_session2_open: channel_new: %d", c->self);
1192 channel_send_open(c->self);
1194 channel_register_confirm(c->self, ssh_session2_setup);
1204 /* XXX should be pre-session */
1205 ssh_init_forwarding();
1207 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1208 id = ssh_session2_open();
1210 /* If requested, let ssh continue in the background. */
1211 if (fork_after_authentication_flag)
1212 if (daemon(1, 1) < 0)
1213 fatal("daemon() failed: %.200s", strerror(errno));
1215 return client_loop(tty_flag, tty_flag ?
1216 options.escape_char : SSH_ESCAPECHAR_NONE, id);
1220 load_public_identity_files(void)
1228 if (options.smartcard_device != NULL &&
1229 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1230 (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL ) {
1232 for (i = 0; keys[i] != NULL; i++) {
1234 memmove(&options.identity_files[1], &options.identity_files[0],
1235 sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1));
1236 memmove(&options.identity_keys[1], &options.identity_keys[0],
1237 sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1));
1238 options.num_identity_files++;
1239 options.identity_keys[0] = keys[i];
1240 options.identity_files[0] = xstrdup("smartcard key");;
1242 if (options.num_identity_files > SSH_MAX_IDENTITY_FILES)
1243 options.num_identity_files = SSH_MAX_IDENTITY_FILES;
1247 #endif /* SMARTCARD */
1248 for (; i < options.num_identity_files; i++) {
1249 filename = tilde_expand_filename(options.identity_files[i],
1251 public = key_load_public(filename, NULL);
1252 debug("identity file %s type %d", filename,
1253 public ? public->type : -1);
1254 xfree(options.identity_files[i]);
1255 options.identity_files[i] = filename;
1256 options.identity_keys[i] = public;