1 /* $OpenBSD: ssh.c,v 1.356 2011/01/06 22:23:53 djm Exp $ */
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * Ssh client program. This program can be used to log into a remote machine.
7 * The software supports strong authentication, encryption, and forwarding
8 * of X11, TCP/IP, and authentication connections.
10 * As far as I am concerned, the code I have written for this software
11 * can be used freely for any purpose. Any derived versions of this
12 * software must be clearly marked as such, and if the derived work is
13 * incompatible with the protocol description in the RFC file, it must be
14 * called by a name other than "ssh" or "Secure Shell".
16 * Copyright (c) 1999 Niels Provos. All rights reserved.
17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved.
19 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
20 * in Canada (German citizen).
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
25 * 1. Redistributions of source code must retain the above copyright
26 * notice, this list of conditions and the following disclaimer.
27 * 2. Redistributions in binary form must reproduce the above copyright
28 * notice, this list of conditions and the following disclaimer in the
29 * documentation and/or other materials provided with the distribution.
31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
45 #include <sys/types.h>
46 #ifdef HAVE_SYS_STAT_H
47 # include <sys/stat.h>
49 #include <sys/resource.h>
50 #include <sys/ioctl.h>
51 #include <sys/param.h>
52 #include <sys/socket.h>
71 #include <netinet/in.h>
72 #include <arpa/inet.h>
74 #include <openssl/evp.h>
75 #include <openssl/err.h>
76 #include "openbsd-compat/openssl-compat.h"
77 #include "openbsd-compat/sys-queue.h"
92 #include "pathnames.h"
94 #include "clientloop.h"
97 #include "sshconnect.h"
109 #include "ssh-pkcs11.h"
112 extern char *__progname
;
114 /* Flag indicating whether debug mode is on. May be set on the command line. */
117 /* Flag indicating whether a tty should be allocated */
120 int force_tty_flag
= 0;
122 /* don't exec a shell */
123 int no_shell_flag
= 0;
126 * Flag indicating that nothing should be read from stdin. This can be set
127 * on the command line.
129 int stdin_null_flag
= 0;
132 * Flag indicating that the current process should be backgrounded and
133 * a new slave launched in the foreground for ControlPersist.
135 int need_controlpersist_detach
= 0;
137 /* Copies of flags for ControlPersist foreground slave */
138 int ostdin_null_flag
, ono_shell_flag
, ono_tty_flag
, otty_flag
;
141 * Flag indicating that ssh should fork after authentication. This is useful
142 * so that the passphrase can be entered manually, and then ssh goes to the
145 int fork_after_authentication_flag
= 0;
147 /* forward stdio to remote host and port */
148 char *stdio_forward_host
= NULL
;
149 int stdio_forward_port
= 0;
152 * General data structure for command line options and options configurable
153 * in configuration files. See readconf.h.
157 /* optional user configfile */
161 * Name of the host we are connecting to. This is the name given on the
162 * command line, or the HostName specified for the user-supplied name in a
163 * configuration file.
167 /* socket address the host resolves to */
168 struct sockaddr_storage hostaddr
;
170 /* Private host keys. */
171 Sensitive sensitive_data
;
173 /* Original real UID. */
174 uid_t original_real_uid
;
175 uid_t original_effective_uid
;
177 /* command to be executed */
180 /* Should we execute a command or invoke a subsystem? */
181 int subsystem_flag
= 0;
183 /* # of replies received for global requests */
184 static int remote_forward_confirms_received
= 0;
187 extern int muxserver_sock
;
188 extern u_int muxclient_command
;
190 /* Prints a help message to the user. This function never returns. */
196 "usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n"
197 " [-D [bind_address:]port] [-e escape_char] [-F configfile]\n"
198 " [-I pkcs11] [-i identity_file]\n"
199 " [-L [bind_address:]port:host:hostport]\n"
200 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
201 " [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
202 " [-W host:port] [-w local_tun[:remote_tun]]\n"
203 " [user@]hostname [command]\n"
208 static int ssh_session(void);
209 static int ssh_session2(void);
210 static void load_public_identity_files(void);
211 static void main_sigchld_handler(int);
213 /* from muxclient.c */
214 void muxclient(const char *);
215 void muxserver_listen(void);
218 * Main program for the ssh client.
221 main(int ac
, char **av
)
223 int i
, r
, opt
, exit_status
, use_syslog
;
224 char *p
, *cp
, *line
, *argv0
, buf
[MAXPATHLEN
], *host_arg
;
227 int dummy
, timeout_ms
;
228 extern int optind
, optreset
;
233 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
236 __progname
= ssh_get_progname(av
[0]);
240 * Discard other fds that are hanging around. These can cause problem
241 * with backgrounded ssh processes started by ControlPersist.
243 closefrom(STDERR_FILENO
+ 1);
246 * Save the original real uid. It will be needed later (uid-swapping
247 * may clobber the real uid).
249 original_real_uid
= getuid();
250 original_effective_uid
= geteuid();
253 * Use uid-swapping to give up root privileges for the duration of
254 * option processing. We will re-instantiate the rights when we are
255 * ready to create the privileged port, and will permanently drop
256 * them when the port has been created (actually, when the connection
257 * has been made, as we may need to create the port several times).
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 pw
= getpwuid(original_real_uid
);
273 logit("You don't exist, go away!");
276 /* Take a copy of the returned structure. */
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.
288 * Initialize option structure to indicate that no values have been
291 initialize_options(&options
);
293 /* Parse command-line arguments. */
299 while ((opt
= getopt(ac
, av
, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
300 "ACD:F:I:KL:MNO:PR:S:TVw:W:XYy")) != -1) {
303 options
.protocol
= SSH_PROTO_1
;
306 options
.protocol
= SSH_PROTO_2
;
309 options
.address_family
= AF_INET
;
312 options
.address_family
= AF_INET6
;
318 fork_after_authentication_flag
= 1;
322 options
.forward_x11
= 0;
325 options
.forward_x11
= 1;
331 options
.forward_x11
= 1;
332 options
.forward_x11_trusted
= 1;
335 options
.gateway_ports
= 1;
338 if (stdio_forward_host
!= NULL
)
339 fatal("Cannot specify multiplexing "
341 else if (muxclient_command
!= 0)
342 fatal("Multiplexing command already specified");
343 if (strcmp(optarg
, "check") == 0)
344 muxclient_command
= SSHMUX_COMMAND_ALIVE_CHECK
;
345 else if (strcmp(optarg
, "forward") == 0)
346 muxclient_command
= SSHMUX_COMMAND_FORWARD
;
347 else if (strcmp(optarg
, "exit") == 0)
348 muxclient_command
= SSHMUX_COMMAND_TERMINATE
;
350 fatal("Invalid multiplex command.");
352 case 'P': /* deprecated */
353 options
.use_privileged_port
= 0;
356 options
.forward_agent
= 0;
359 options
.forward_agent
= 1;
362 options
.gss_deleg_creds
= 0;
365 options
.gss_authentication
= 1;
366 options
.gss_deleg_creds
= 1;
369 if (stat(optarg
, &st
) < 0) {
370 fprintf(stderr
, "Warning: Identity file %s "
371 "not accessible: %s.\n", optarg
,
375 if (options
.num_identity_files
>=
376 SSH_MAX_IDENTITY_FILES
)
377 fatal("Too many identity files specified "
378 "(max %d)", SSH_MAX_IDENTITY_FILES
);
379 options
.identity_files
[options
.num_identity_files
++] =
384 options
.pkcs11_provider
= xstrdup(optarg
);
386 fprintf(stderr
, "no support for PKCS#11.\n");
395 if (debug_flag
== 0) {
397 options
.log_level
= SYSLOG_LEVEL_DEBUG1
;
399 if (options
.log_level
< SYSLOG_LEVEL_DEBUG3
)
405 fprintf(stderr
, "%s, %s\n",
406 SSH_RELEASE
, SSLeay_version(SSLEAY_VERSION
));
411 if (options
.tun_open
== -1)
412 options
.tun_open
= SSH_TUNMODE_DEFAULT
;
413 options
.tun_local
= a2tun(optarg
, &options
.tun_remote
);
414 if (options
.tun_local
== SSH_TUNID_ERR
) {
416 "Bad tun device '%s'\n", optarg
);
421 if (stdio_forward_host
!= NULL
)
422 fatal("stdio forward already specified");
423 if (muxclient_command
!= 0)
424 fatal("Cannot specify stdio forward with -O");
425 if (parse_forward(&fwd
, optarg
, 1, 0)) {
426 stdio_forward_host
= fwd
.listen_host
;
427 stdio_forward_port
= fwd
.listen_port
;
428 xfree(fwd
.connect_host
);
431 "Bad stdio forwarding specification '%s'\n",
437 options
.clear_forwardings
= 1;
438 options
.exit_on_forward_failure
= 1;
441 options
.log_level
= SYSLOG_LEVEL_QUIET
;
444 if (optarg
[0] == '^' && optarg
[2] == 0 &&
445 (u_char
) optarg
[1] >= 64 &&
446 (u_char
) optarg
[1] < 128)
447 options
.escape_char
= (u_char
) optarg
[1] & 31;
448 else if (strlen(optarg
) == 1)
449 options
.escape_char
= (u_char
) optarg
[0];
450 else if (strcmp(optarg
, "none") == 0)
451 options
.escape_char
= SSH_ESCAPECHAR_NONE
;
453 fprintf(stderr
, "Bad escape character '%s'.\n",
459 if (ciphers_valid(optarg
)) {
461 options
.ciphers
= xstrdup(optarg
);
462 options
.cipher
= SSH_CIPHER_INVALID
;
465 options
.cipher
= cipher_number(optarg
);
466 if (options
.cipher
== -1) {
468 "Unknown cipher type '%s'\n",
472 if (options
.cipher
== SSH_CIPHER_3DES
)
473 options
.ciphers
= "3des-cbc";
474 else if (options
.cipher
== SSH_CIPHER_BLOWFISH
)
475 options
.ciphers
= "blowfish-cbc";
477 options
.ciphers
= (char *)-1;
481 if (mac_valid(optarg
))
482 options
.macs
= xstrdup(optarg
);
484 fprintf(stderr
, "Unknown mac type '%s'\n",
490 if (options
.control_master
== SSHCTL_MASTER_YES
)
491 options
.control_master
= SSHCTL_MASTER_ASK
;
493 options
.control_master
= SSHCTL_MASTER_YES
;
496 options
.port
= a2port(optarg
);
497 if (options
.port
<= 0) {
498 fprintf(stderr
, "Bad port '%s'\n", optarg
);
503 options
.user
= optarg
;
507 if (parse_forward(&fwd
, optarg
, 0, 0))
508 add_local_forward(&options
, &fwd
);
511 "Bad local forwarding specification '%s'\n",
518 if (parse_forward(&fwd
, optarg
, 0, 1)) {
519 add_remote_forward(&options
, &fwd
);
522 "Bad remote forwarding specification "
529 if (parse_forward(&fwd
, optarg
, 1, 0)) {
530 add_local_forward(&options
, &fwd
);
533 "Bad dynamic forwarding specification "
540 options
.compression
= 1;
551 line
= xstrdup(optarg
);
552 if (process_config_line(&options
, host
? host
: "",
553 line
, "command-line", 0, &dummy
) != 0)
561 if (options
.control_path
!= NULL
)
562 free(options
.control_path
);
563 options
.control_path
= xstrdup(optarg
);
566 options
.bind_address
= optarg
;
579 if (ac
> 0 && !host
) {
580 if (strrchr(*av
, '@')) {
582 cp
= strrchr(p
, '@');
583 if (cp
== NULL
|| cp
== p
)
591 optind
= optreset
= 1;
597 /* Check that we got a host name. */
601 OpenSSL_add_all_algorithms();
602 ERR_load_crypto_strings();
604 /* Initialize the command to execute on remote host. */
605 buffer_init(&command
);
608 * Save the command to execute on the remote host in a buffer. There
609 * is no limit on the length of the command, except by the maximum
610 * packet size. Also sets the tty flag if there is no command.
613 /* No command specified - execute shell on a tty. */
615 if (subsystem_flag
) {
617 "You must specify a subsystem to invoke.\n");
621 /* A command has been specified. Store it into the buffer. */
622 for (i
= 0; i
< ac
; i
++) {
624 buffer_append(&command
, " ", 1);
625 buffer_append(&command
, av
[i
], strlen(av
[i
]));
629 /* Cannot fork to background if no command. */
630 if (fork_after_authentication_flag
&& buffer_len(&command
) == 0 &&
632 fatal("Cannot fork into background without a command "
635 /* Allocate a tty by default if no command specified. */
636 if (buffer_len(&command
) == 0)
640 if (no_tty_flag
|| muxclient_command
!= 0)
642 /* Do not allocate a tty if stdin is not a tty. */
643 if ((!isatty(fileno(stdin
)) || stdin_null_flag
) && !force_tty_flag
) {
645 logit("Pseudo-terminal will not be allocated because "
646 "stdin is not a terminal.");
651 * Initialize "log" output. Since we are the client all output
652 * actually goes to stderr.
655 options
.log_level
== -1 ? SYSLOG_LEVEL_INFO
: options
.log_level
,
656 SYSLOG_FACILITY_USER
, !use_syslog
);
659 * Read per-user configuration file. Ignore the system wide config
660 * file if the user specifies a config file on the command line.
662 if (config
!= NULL
) {
663 if (!read_config_file(config
, host
, &options
, 0))
664 fatal("Can't open user config file %.100s: "
665 "%.100s", config
, strerror(errno
));
667 r
= snprintf(buf
, sizeof buf
, "%s/%s", pw
->pw_dir
,
668 _PATH_SSH_USER_CONFFILE
);
669 if (r
> 0 && (size_t)r
< sizeof(buf
))
670 (void)read_config_file(buf
, host
, &options
, 1);
672 /* Read systemwide configuration file after use config. */
673 (void)read_config_file(_PATH_HOST_CONFIG_FILE
, host
,
677 /* Fill configuration defaults. */
678 fill_default_options(&options
);
680 channel_set_af(options
.address_family
);
683 log_init(argv0
, options
.log_level
, SYSLOG_FACILITY_USER
, !use_syslog
);
687 if (options
.user
== NULL
)
688 options
.user
= xstrdup(pw
->pw_name
);
690 /* Get default port if port has not been set. */
691 if (options
.port
== 0) {
692 sp
= getservbyname(SSH_SERVICE_NAME
, "tcp");
693 options
.port
= sp
? ntohs(sp
->s_port
) : SSH_DEFAULT_PORT
;
696 /* preserve host name given on command line for %n expansion */
698 if (options
.hostname
!= NULL
) {
699 host
= percent_expand(options
.hostname
,
700 "h", host
, (char *)NULL
);
703 if (options
.local_command
!= NULL
) {
704 char thishost
[NI_MAXHOST
];
706 if (gethostname(thishost
, sizeof(thishost
)) == -1)
707 fatal("gethostname: %s", strerror(errno
));
708 snprintf(buf
, sizeof(buf
), "%d", options
.port
);
709 debug3("expanding LocalCommand: %s", options
.local_command
);
710 cp
= options
.local_command
;
711 options
.local_command
= percent_expand(cp
, "d", pw
->pw_dir
,
712 "h", host
, "l", thishost
, "n", host_arg
, "r", options
.user
,
713 "p", buf
, "u", pw
->pw_name
, (char *)NULL
);
714 debug3("expanded LocalCommand: %s", options
.local_command
);
718 /* force lowercase for hostkey matching */
719 if (options
.host_key_alias
!= NULL
) {
720 for (p
= options
.host_key_alias
; *p
; p
++)
722 *p
= (char)tolower(*p
);
725 if (options
.proxy_command
!= NULL
&&
726 strcmp(options
.proxy_command
, "none") == 0) {
727 xfree(options
.proxy_command
);
728 options
.proxy_command
= NULL
;
730 if (options
.control_path
!= NULL
&&
731 strcmp(options
.control_path
, "none") == 0) {
732 xfree(options
.control_path
);
733 options
.control_path
= NULL
;
736 if (options
.control_path
!= NULL
) {
737 char thishost
[NI_MAXHOST
];
739 if (gethostname(thishost
, sizeof(thishost
)) == -1)
740 fatal("gethostname: %s", strerror(errno
));
741 snprintf(buf
, sizeof(buf
), "%d", options
.port
);
742 cp
= tilde_expand_filename(options
.control_path
,
744 xfree(options
.control_path
);
745 options
.control_path
= percent_expand(cp
, "p", buf
, "h", host
,
746 "r", options
.user
, "l", thishost
, (char *)NULL
);
749 if (muxclient_command
!= 0 && options
.control_path
== NULL
)
750 fatal("No ControlPath specified for \"-O\" command");
751 if (options
.control_path
!= NULL
)
752 muxclient(options
.control_path
);
754 timeout_ms
= options
.connection_timeout
* 1000;
756 /* Open a connection to the remote host. */
757 if (ssh_connect(host
, &hostaddr
, options
.port
,
758 options
.address_family
, options
.connection_attempts
, &timeout_ms
,
759 options
.tcp_keep_alive
,
761 options
.use_privileged_port
,
763 original_effective_uid
== 0 && options
.use_privileged_port
,
765 options
.proxy_command
) != 0)
769 debug3("timeout: %d ms remain after connect", timeout_ms
);
772 * If we successfully made the connection, load the host private key
773 * in case we will need it later for combined rsa-rhosts
774 * authentication. This must be done before releasing extra
775 * privileges, because the file is only readable by root.
776 * If we cannot access the private keys, load the public keys
777 * instead and try to execute the ssh-keysign helper instead.
779 sensitive_data
.nkeys
= 0;
780 sensitive_data
.keys
= NULL
;
781 sensitive_data
.external_keysign
= 0;
782 if (options
.rhosts_rsa_authentication
||
783 options
.hostbased_authentication
) {
784 sensitive_data
.nkeys
= 7;
785 sensitive_data
.keys
= xcalloc(sensitive_data
.nkeys
,
787 for (i
= 0; i
< sensitive_data
.nkeys
; i
++)
788 sensitive_data
.keys
[i
] = NULL
;
791 sensitive_data
.keys
[0] = key_load_private_type(KEY_RSA1
,
792 _PATH_HOST_KEY_FILE
, "", NULL
, NULL
);
793 sensitive_data
.keys
[1] = key_load_private_cert(KEY_DSA
,
794 _PATH_HOST_DSA_KEY_FILE
, "", NULL
);
795 #ifdef OPENSSL_HAS_ECC
796 sensitive_data
.keys
[2] = key_load_private_cert(KEY_ECDSA
,
797 _PATH_HOST_ECDSA_KEY_FILE
, "", NULL
);
799 sensitive_data
.keys
[3] = key_load_private_cert(KEY_RSA
,
800 _PATH_HOST_RSA_KEY_FILE
, "", NULL
);
801 sensitive_data
.keys
[4] = key_load_private_type(KEY_DSA
,
802 _PATH_HOST_DSA_KEY_FILE
, "", NULL
, NULL
);
803 #ifdef OPENSSL_HAS_ECC
804 sensitive_data
.keys
[5] = key_load_private_type(KEY_ECDSA
,
805 _PATH_HOST_ECDSA_KEY_FILE
, "", NULL
, NULL
);
807 sensitive_data
.keys
[6] = key_load_private_type(KEY_RSA
,
808 _PATH_HOST_RSA_KEY_FILE
, "", NULL
, NULL
);
811 if (options
.hostbased_authentication
== 1 &&
812 sensitive_data
.keys
[0] == NULL
&&
813 sensitive_data
.keys
[4] == NULL
&&
814 sensitive_data
.keys
[5] == NULL
&&
815 sensitive_data
.keys
[6] == NULL
) {
816 sensitive_data
.keys
[1] = key_load_cert(
817 _PATH_HOST_DSA_KEY_FILE
);
818 #ifdef OPENSSL_HAS_ECC
819 sensitive_data
.keys
[2] = key_load_cert(
820 _PATH_HOST_ECDSA_KEY_FILE
);
822 sensitive_data
.keys
[3] = key_load_cert(
823 _PATH_HOST_RSA_KEY_FILE
);
824 sensitive_data
.keys
[4] = key_load_public(
825 _PATH_HOST_DSA_KEY_FILE
, NULL
);
826 #ifdef OPENSSL_HAS_ECC
827 sensitive_data
.keys
[5] = key_load_public(
828 _PATH_HOST_ECDSA_KEY_FILE
, NULL
);
830 sensitive_data
.keys
[6] = key_load_public(
831 _PATH_HOST_RSA_KEY_FILE
, NULL
);
832 sensitive_data
.external_keysign
= 1;
836 * Get rid of any extra privileges that we may have. We will no
837 * longer need them. Also, extra privileges could make it very hard
838 * to read identity files and other non-world-readable files from the
839 * user's home directory if it happens to be on a NFS volume where
840 * root is mapped to nobody.
842 if (original_effective_uid
== 0) {
844 permanently_set_uid(pw
);
848 * Now that we are back to our own permissions, create ~/.ssh
849 * directory if it doesn't already exist.
851 r
= snprintf(buf
, sizeof buf
, "%s%s%s", pw
->pw_dir
,
852 strcmp(pw
->pw_dir
, "/") ? "/" : "", _PATH_SSH_USER_DIR
);
853 if (r
> 0 && (size_t)r
< sizeof(buf
) && stat(buf
, &st
) < 0) {
855 ssh_selinux_setfscreatecon(buf
);
857 if (mkdir(buf
, 0700) < 0)
858 error("Could not create directory '%.200s'.", buf
);
860 ssh_selinux_setfscreatecon(NULL
);
863 /* load options.identity_files */
864 load_public_identity_files();
866 /* Expand ~ in known host file names. */
868 options
.system_hostfile
=
869 tilde_expand_filename(options
.system_hostfile
, original_real_uid
);
870 options
.user_hostfile
=
871 tilde_expand_filename(options
.user_hostfile
, original_real_uid
);
872 options
.system_hostfile2
=
873 tilde_expand_filename(options
.system_hostfile2
, original_real_uid
);
874 options
.user_hostfile2
=
875 tilde_expand_filename(options
.user_hostfile2
, original_real_uid
);
877 signal(SIGPIPE
, SIG_IGN
); /* ignore SIGPIPE early */
878 signal(SIGCHLD
, main_sigchld_handler
);
880 /* Log into the remote system. Never returns if the login fails. */
881 ssh_login(&sensitive_data
, host
, (struct sockaddr
*)&hostaddr
,
882 options
.port
, pw
, timeout_ms
);
884 if (packet_connection_is_on_socket()) {
885 verbose("Authenticated to %s ([%s]:%d).", host
,
886 get_remote_ipaddr(), get_remote_port());
888 verbose("Authenticated to %s (via proxy).", host
);
891 /* We no longer need the private host keys. Clear them now. */
892 if (sensitive_data
.nkeys
!= 0) {
893 for (i
= 0; i
< sensitive_data
.nkeys
; i
++) {
894 if (sensitive_data
.keys
[i
] != NULL
) {
895 /* Destroys contents safely */
896 debug3("clear hostkey %d", i
);
897 key_free(sensitive_data
.keys
[i
]);
898 sensitive_data
.keys
[i
] = NULL
;
901 xfree(sensitive_data
.keys
);
903 for (i
= 0; i
< options
.num_identity_files
; i
++) {
904 if (options
.identity_files
[i
]) {
905 xfree(options
.identity_files
[i
]);
906 options
.identity_files
[i
] = NULL
;
908 if (options
.identity_keys
[i
]) {
909 key_free(options
.identity_keys
[i
]);
910 options
.identity_keys
[i
] = NULL
;
914 exit_status
= compat20
? ssh_session2() : ssh_session();
917 if (options
.control_path
!= NULL
&& muxserver_sock
!= -1)
918 unlink(options
.control_path
);
920 /* Kill ProxyCommand if it is running. */
921 ssh_kill_proxy_command();
927 control_persist_detach(void)
932 debug("%s: backgrounding master process", __func__
);
935 * master (current process) into the background, and make the
936 * foreground process a client of the backgrounded master.
938 switch ((pid
= fork())) {
940 fatal("%s: fork: %s", __func__
, strerror(errno
));
942 /* Child: master process continues mainloop */
945 /* Parent: set up mux slave to connect to backgrounded master */
946 debug2("%s: background process is %ld", __func__
, (long)pid
);
947 stdin_null_flag
= ostdin_null_flag
;
948 no_shell_flag
= ono_shell_flag
;
949 no_tty_flag
= ono_tty_flag
;
950 tty_flag
= otty_flag
;
951 close(muxserver_sock
);
953 options
.control_master
= SSHCTL_MASTER_NO
;
954 muxclient(options
.control_path
);
955 /* muxclient() doesn't return on success. */
956 fatal("Failed to connect to new control master");
958 if ((devnull
= open(_PATH_DEVNULL
, O_RDWR
)) == -1) {
959 error("%s: open(\"/dev/null\"): %s", __func__
,
962 if (dup2(devnull
, STDIN_FILENO
) == -1 ||
963 dup2(devnull
, STDOUT_FILENO
) == -1)
964 error("%s: dup2: %s", __func__
, strerror(errno
));
965 if (devnull
> STDERR_FILENO
)
970 /* Do fork() after authentication. Used by "ssh -f" */
974 if (need_controlpersist_detach
)
975 control_persist_detach();
976 debug("forking to background");
977 fork_after_authentication_flag
= 0;
978 if (daemon(1, 1) < 0)
979 fatal("daemon() failed: %.200s", strerror(errno
));
982 /* Callback for remote forward global requests */
984 ssh_confirm_remote_forward(int type
, u_int32_t seq
, void *ctxt
)
986 Forward
*rfwd
= (Forward
*)ctxt
;
988 /* XXX verbose() on failure? */
989 debug("remote forward %s for: listen %d, connect %s:%d",
990 type
== SSH2_MSG_REQUEST_SUCCESS
? "success" : "failure",
991 rfwd
->listen_port
, rfwd
->connect_host
, rfwd
->connect_port
);
992 if (type
== SSH2_MSG_REQUEST_SUCCESS
&& rfwd
->listen_port
== 0) {
993 rfwd
->allocated_port
= packet_get_int();
994 logit("Allocated port %u for remote forward to %s:%d",
995 rfwd
->allocated_port
,
996 rfwd
->connect_host
, rfwd
->connect_port
);
999 if (type
== SSH2_MSG_REQUEST_FAILURE
) {
1000 if (options
.exit_on_forward_failure
)
1001 fatal("Error: remote port forwarding failed for "
1002 "listen port %d", rfwd
->listen_port
);
1004 logit("Warning: remote port forwarding failed for "
1005 "listen port %d", rfwd
->listen_port
);
1007 if (++remote_forward_confirms_received
== options
.num_remote_forwards
) {
1008 debug("All remote forwarding requests processed");
1009 if (fork_after_authentication_flag
)
1015 client_cleanup_stdio_fwd(int id
, void *arg
)
1017 debug("stdio forwarding: done");
1022 client_setup_stdio_fwd(const char *host_to_connect
, u_short port_to_connect
)
1027 debug3("client_setup_stdio_fwd %s:%d", host_to_connect
,
1030 in
= dup(STDIN_FILENO
);
1031 out
= dup(STDOUT_FILENO
);
1032 if (in
< 0 || out
< 0)
1033 fatal("channel_connect_stdio_fwd: dup() in/out failed");
1035 if ((c
= channel_connect_stdio_fwd(host_to_connect
, port_to_connect
,
1038 channel_register_cleanup(c
->self
, client_cleanup_stdio_fwd
, 0);
1043 ssh_init_forwarding(void)
1048 if (stdio_forward_host
!= NULL
) {
1050 fatal("stdio forwarding require Protocol 2");
1052 if (!client_setup_stdio_fwd(stdio_forward_host
,
1053 stdio_forward_port
))
1054 fatal("Failed to connect in stdio forward mode.");
1057 /* Initiate local TCP/IP port forwardings. */
1058 for (i
= 0; i
< options
.num_local_forwards
; i
++) {
1059 debug("Local connections to %.200s:%d forwarded to remote "
1060 "address %.200s:%d",
1061 (options
.local_forwards
[i
].listen_host
== NULL
) ?
1062 (options
.gateway_ports
? "*" : "LOCALHOST") :
1063 options
.local_forwards
[i
].listen_host
,
1064 options
.local_forwards
[i
].listen_port
,
1065 options
.local_forwards
[i
].connect_host
,
1066 options
.local_forwards
[i
].connect_port
);
1067 success
+= channel_setup_local_fwd_listener(
1068 options
.local_forwards
[i
].listen_host
,
1069 options
.local_forwards
[i
].listen_port
,
1070 options
.local_forwards
[i
].connect_host
,
1071 options
.local_forwards
[i
].connect_port
,
1072 options
.gateway_ports
);
1074 if (i
> 0 && success
!= i
&& options
.exit_on_forward_failure
)
1075 fatal("Could not request local forwarding.");
1076 if (i
> 0 && success
== 0)
1077 error("Could not request local forwarding.");
1079 /* Initiate remote TCP/IP port forwardings. */
1080 for (i
= 0; i
< options
.num_remote_forwards
; i
++) {
1081 debug("Remote connections from %.200s:%d forwarded to "
1082 "local address %.200s:%d",
1083 (options
.remote_forwards
[i
].listen_host
== NULL
) ?
1084 "LOCALHOST" : options
.remote_forwards
[i
].listen_host
,
1085 options
.remote_forwards
[i
].listen_port
,
1086 options
.remote_forwards
[i
].connect_host
,
1087 options
.remote_forwards
[i
].connect_port
);
1088 if (channel_request_remote_forwarding(
1089 options
.remote_forwards
[i
].listen_host
,
1090 options
.remote_forwards
[i
].listen_port
,
1091 options
.remote_forwards
[i
].connect_host
,
1092 options
.remote_forwards
[i
].connect_port
) < 0) {
1093 if (options
.exit_on_forward_failure
)
1094 fatal("Could not request remote forwarding.");
1096 logit("Warning: Could not request remote "
1099 client_register_global_confirm(ssh_confirm_remote_forward
,
1100 &options
.remote_forwards
[i
]);
1103 /* Initiate tunnel forwarding. */
1104 if (options
.tun_open
!= SSH_TUNMODE_NO
) {
1105 if (client_request_tun_fwd(options
.tun_open
,
1106 options
.tun_local
, options
.tun_remote
) == -1) {
1107 if (options
.exit_on_forward_failure
)
1108 fatal("Could not request tunnel forwarding.");
1110 error("Could not request tunnel forwarding.");
1116 check_agent_present(void)
1118 if (options
.forward_agent
) {
1119 /* Clear agent forwarding if we don't have an agent. */
1120 if (!ssh_agent_present())
1121 options
.forward_agent
= 0;
1129 int interactive
= 0;
1133 const char *display
;
1135 /* Enable compression if requested. */
1136 if (options
.compression
) {
1137 debug("Requesting compression at level %d.",
1138 options
.compression_level
);
1140 if (options
.compression_level
< 1 ||
1141 options
.compression_level
> 9)
1142 fatal("Compression level must be from 1 (fast) to "
1145 /* Send the request. */
1146 packet_start(SSH_CMSG_REQUEST_COMPRESSION
);
1147 packet_put_int(options
.compression_level
);
1149 packet_write_wait();
1150 type
= packet_read();
1151 if (type
== SSH_SMSG_SUCCESS
)
1152 packet_start_compression(options
.compression_level
);
1153 else if (type
== SSH_SMSG_FAILURE
)
1154 logit("Warning: Remote host refused compression.");
1156 packet_disconnect("Protocol error waiting for "
1157 "compression response.");
1159 /* Allocate a pseudo tty if appropriate. */
1161 debug("Requesting pty.");
1163 /* Start the packet. */
1164 packet_start(SSH_CMSG_REQUEST_PTY
);
1166 /* Store TERM in the packet. There is no limit on the
1167 length of the string. */
1168 cp
= getenv("TERM");
1171 packet_put_cstring(cp
);
1173 /* Store window size in the packet. */
1174 if (ioctl(fileno(stdin
), TIOCGWINSZ
, &ws
) < 0)
1175 memset(&ws
, 0, sizeof(ws
));
1176 packet_put_int((u_int
)ws
.ws_row
);
1177 packet_put_int((u_int
)ws
.ws_col
);
1178 packet_put_int((u_int
)ws
.ws_xpixel
);
1179 packet_put_int((u_int
)ws
.ws_ypixel
);
1181 /* Store tty modes in the packet. */
1182 tty_make_modes(fileno(stdin
), NULL
);
1184 /* Send the packet, and wait for it to leave. */
1186 packet_write_wait();
1188 /* Read response from the server. */
1189 type
= packet_read();
1190 if (type
== SSH_SMSG_SUCCESS
) {
1193 } else if (type
== SSH_SMSG_FAILURE
)
1194 logit("Warning: Remote host failed or refused to "
1195 "allocate a pseudo tty.");
1197 packet_disconnect("Protocol error waiting for pty "
1198 "request response.");
1200 /* Request X11 forwarding if enabled and DISPLAY is set. */
1201 display
= getenv("DISPLAY");
1202 if (options
.forward_x11
&& display
!= NULL
) {
1204 /* Get reasonable local authentication information. */
1205 client_x11_get_proto(display
, options
.xauth_location
,
1206 options
.forward_x11_trusted
,
1207 options
.forward_x11_timeout
,
1209 /* Request forwarding with authentication spoofing. */
1210 debug("Requesting X11 forwarding with authentication "
1212 x11_request_forwarding_with_spoofing(0, display
, proto
, data
);
1214 /* Read response from the server. */
1215 type
= packet_read();
1216 if (type
== SSH_SMSG_SUCCESS
) {
1218 } else if (type
== SSH_SMSG_FAILURE
) {
1219 logit("Warning: Remote host denied X11 forwarding.");
1221 packet_disconnect("Protocol error waiting for X11 "
1225 /* Tell the packet module whether this is an interactive session. */
1226 packet_set_interactive(interactive
,
1227 options
.ip_qos_interactive
, options
.ip_qos_bulk
);
1229 /* Request authentication agent forwarding if appropriate. */
1230 check_agent_present();
1232 if (options
.forward_agent
) {
1233 debug("Requesting authentication agent forwarding.");
1234 auth_request_forwarding();
1236 /* Read response from the server. */
1237 type
= packet_read();
1239 if (type
!= SSH_SMSG_SUCCESS
)
1240 logit("Warning: Remote host denied authentication agent forwarding.");
1243 /* Initiate port forwardings. */
1244 ssh_init_forwarding();
1246 /* Execute a local command */
1247 if (options
.local_command
!= NULL
&&
1248 options
.permit_local_command
)
1249 ssh_local_cmd(options
.local_command
);
1252 * If requested and we are not interested in replies to remote
1253 * forwarding requests, then let ssh continue in the background.
1255 if (fork_after_authentication_flag
) {
1256 if (options
.exit_on_forward_failure
&&
1257 options
.num_remote_forwards
> 0) {
1258 debug("deferring postauth fork until remote forward "
1259 "confirmation received");
1265 * If a command was specified on the command line, execute the
1266 * command now. Otherwise request the server to start a shell.
1268 if (buffer_len(&command
) > 0) {
1269 int len
= buffer_len(&command
);
1272 debug("Sending command: %.*s", len
,
1273 (u_char
*)buffer_ptr(&command
));
1274 packet_start(SSH_CMSG_EXEC_CMD
);
1275 packet_put_string(buffer_ptr(&command
), buffer_len(&command
));
1277 packet_write_wait();
1279 debug("Requesting shell.");
1280 packet_start(SSH_CMSG_EXEC_SHELL
);
1282 packet_write_wait();
1285 /* Enter the interactive session. */
1286 return client_loop(have_tty
, tty_flag
?
1287 options
.escape_char
: SSH_ESCAPECHAR_NONE
, 0);
1290 /* request pty/x11/agent/tcpfwd/shell for channel */
1292 ssh_session2_setup(int id
, int success
, void *arg
)
1294 extern char **environ
;
1295 const char *display
;
1296 int interactive
= tty_flag
;
1299 return; /* No need for error message, channels code sens one */
1301 display
= getenv("DISPLAY");
1302 if (options
.forward_x11
&& display
!= NULL
) {
1304 /* Get reasonable local authentication information. */
1305 client_x11_get_proto(display
, options
.xauth_location
,
1306 options
.forward_x11_trusted
,
1307 options
.forward_x11_timeout
, &proto
, &data
);
1308 /* Request forwarding with authentication spoofing. */
1309 debug("Requesting X11 forwarding with authentication "
1311 x11_request_forwarding_with_spoofing(id
, display
, proto
, data
);
1313 /* XXX wait for reply */
1316 check_agent_present();
1317 if (options
.forward_agent
) {
1318 debug("Requesting authentication agent forwarding.");
1319 channel_request_start(id
, "auth-agent-req@openssh.com", 0);
1323 client_session2_setup(id
, tty_flag
, subsystem_flag
, getenv("TERM"),
1324 NULL
, fileno(stdin
), &command
, environ
);
1327 /* open new channel for a session */
1329 ssh_session2_open(void)
1332 int window
, packetmax
, in
, out
, err
;
1334 if (stdin_null_flag
) {
1335 in
= open(_PATH_DEVNULL
, O_RDONLY
);
1337 in
= dup(STDIN_FILENO
);
1339 out
= dup(STDOUT_FILENO
);
1340 err
= dup(STDERR_FILENO
);
1342 if (in
< 0 || out
< 0 || err
< 0)
1343 fatal("dup() in/out/err failed");
1345 /* enable nonblocking unless tty */
1353 window
= CHAN_SES_WINDOW_DEFAULT
;
1354 packetmax
= CHAN_SES_PACKET_DEFAULT
;
1360 "session", SSH_CHANNEL_OPENING
, in
, out
, err
,
1361 window
, packetmax
, CHAN_EXTENDED_WRITE
,
1362 "client-session", /*nonblock*/0);
1364 debug3("ssh_session2_open: channel_new: %d", c
->self
);
1366 channel_send_open(c
->self
);
1368 channel_register_open_confirm(c
->self
,
1369 ssh_session2_setup
, NULL
);
1379 /* XXX should be pre-session */
1380 ssh_init_forwarding();
1382 /* Start listening for multiplex clients */
1386 * If we are in control persist mode, then prepare to background
1387 * ourselves and have a foreground client attach as a control
1388 * slave. NB. we must save copies of the flags that we override for
1389 * the backgrounding, since we defer attachment of the slave until
1390 * after the connection is fully established (in particular,
1391 * async rfwd replies have been received for ExitOnForwardFailure).
1393 if (options
.control_persist
&& muxserver_sock
!= -1) {
1394 ostdin_null_flag
= stdin_null_flag
;
1395 ono_shell_flag
= no_shell_flag
;
1396 ono_tty_flag
= no_tty_flag
;
1397 otty_flag
= tty_flag
;
1398 stdin_null_flag
= 1;
1402 if (!fork_after_authentication_flag
)
1403 need_controlpersist_detach
= 1;
1404 fork_after_authentication_flag
= 1;
1407 if (!no_shell_flag
|| (datafellows
& SSH_BUG_DUMMYCHAN
))
1408 id
= ssh_session2_open();
1410 /* If we don't expect to open a new session, then disallow it */
1411 if (options
.control_master
== SSHCTL_MASTER_NO
&&
1412 (datafellows
& SSH_NEW_OPENSSH
)) {
1413 debug("Requesting no-more-sessions@openssh.com");
1414 packet_start(SSH2_MSG_GLOBAL_REQUEST
);
1415 packet_put_cstring("no-more-sessions@openssh.com");
1420 /* Execute a local command */
1421 if (options
.local_command
!= NULL
&&
1422 options
.permit_local_command
)
1423 ssh_local_cmd(options
.local_command
);
1426 * If requested and we are not interested in replies to remote
1427 * forwarding requests, then let ssh continue in the background.
1429 if (fork_after_authentication_flag
) {
1430 if (options
.exit_on_forward_failure
&&
1431 options
.num_remote_forwards
> 0) {
1432 debug("deferring postauth fork until remote forward "
1433 "confirmation received");
1438 if (options
.use_roaming
)
1441 return client_loop(tty_flag
, tty_flag
?
1442 options
.escape_char
: SSH_ESCAPECHAR_NONE
, id
);
1446 load_public_identity_files(void)
1448 char *filename
, *cp
, thishost
[NI_MAXHOST
];
1449 char *pwdir
= NULL
, *pwname
= NULL
;
1454 char *identity_files
[SSH_MAX_IDENTITY_FILES
];
1455 Key
*identity_keys
[SSH_MAX_IDENTITY_FILES
];
1456 #ifdef ENABLE_PKCS11
1462 bzero(identity_files
, sizeof(identity_files
));
1463 bzero(identity_keys
, sizeof(identity_keys
));
1465 #ifdef ENABLE_PKCS11
1466 if (options
.pkcs11_provider
!= NULL
&&
1467 options
.num_identity_files
< SSH_MAX_IDENTITY_FILES
&&
1468 (pkcs11_init(!options
.batch_mode
) == 0) &&
1469 (nkeys
= pkcs11_add_provider(options
.pkcs11_provider
, NULL
,
1471 for (i
= 0; i
< nkeys
; i
++) {
1472 if (n_ids
>= SSH_MAX_IDENTITY_FILES
) {
1476 identity_keys
[n_ids
] = keys
[i
];
1477 identity_files
[n_ids
] =
1478 xstrdup(options
.pkcs11_provider
); /* XXX */
1483 #endif /* ENABLE_PKCS11 */
1484 if ((pw
= getpwuid(original_real_uid
)) == NULL
)
1485 fatal("load_public_identity_files: getpwuid failed");
1486 pwname
= xstrdup(pw
->pw_name
);
1487 pwdir
= xstrdup(pw
->pw_dir
);
1488 if (gethostname(thishost
, sizeof(thishost
)) == -1)
1489 fatal("load_public_identity_files: gethostname: %s",
1491 for (i
= 0; i
< options
.num_identity_files
; i
++) {
1492 if (n_ids
>= SSH_MAX_IDENTITY_FILES
) {
1493 xfree(options
.identity_files
[i
]);
1496 cp
= tilde_expand_filename(options
.identity_files
[i
],
1498 filename
= percent_expand(cp
, "d", pwdir
,
1499 "u", pwname
, "l", thishost
, "h", host
,
1500 "r", options
.user
, (char *)NULL
);
1502 public = key_load_public(filename
, NULL
);
1503 debug("identity file %s type %d", filename
,
1504 public ? public->type
: -1);
1505 xfree(options
.identity_files
[i
]);
1506 identity_files
[n_ids
] = filename
;
1507 identity_keys
[n_ids
] = public;
1509 if (++n_ids
>= SSH_MAX_IDENTITY_FILES
)
1512 /* Try to add the certificate variant too */
1513 xasprintf(&cp
, "%s-cert", filename
);
1514 public = key_load_public(cp
, NULL
);
1515 debug("identity file %s type %d", cp
,
1516 public ? public->type
: -1);
1517 if (public == NULL
) {
1521 if (!key_is_cert(public)) {
1522 debug("%s: key %s type %s is not a certificate",
1523 __func__
, cp
, key_type(public));
1528 identity_keys
[n_ids
] = public;
1529 /* point to the original path, most likely the private key */
1530 identity_files
[n_ids
] = xstrdup(filename
);
1533 options
.num_identity_files
= n_ids
;
1534 memcpy(options
.identity_files
, identity_files
, sizeof(identity_files
));
1535 memcpy(options
.identity_keys
, identity_keys
, sizeof(identity_keys
));
1537 bzero(pwname
, strlen(pwname
));
1539 bzero(pwdir
, strlen(pwdir
));
1544 main_sigchld_handler(int sig
)
1546 int save_errno
= errno
;
1550 while ((pid
= waitpid(-1, &status
, WNOHANG
)) > 0 ||
1551 (pid
< 0 && errno
== EINTR
))
1554 signal(sig
, main_sigchld_handler
);