1 /* $OpenBSD: ssh.c,v 1.407 2014/07/17 07:22:19 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>
75 #include <openssl/evp.h>
76 #include <openssl/err.h>
78 #include "openbsd-compat/openssl-compat.h"
79 #include "openbsd-compat/sys-queue.h"
95 #include "pathnames.h"
97 #include "clientloop.h"
100 #include "readconf.h"
101 #include "sshconnect.h"
112 #include "ssh-pkcs11.h"
115 extern char *__progname
;
117 /* Saves a copy of argv for setproctitle emulation */
118 #ifndef HAVE_SETPROCTITLE
119 static char **saved_av
;
122 /* Flag indicating whether debug mode is on. May be set on the command line. */
125 /* Flag indicating whether a tty should be requested */
128 /* don't exec a shell */
129 int no_shell_flag
= 0;
132 * Flag indicating that nothing should be read from stdin. This can be set
133 * on the command line.
135 int stdin_null_flag
= 0;
138 * Flag indicating that the current process should be backgrounded and
139 * a new slave launched in the foreground for ControlPersist.
141 int need_controlpersist_detach
= 0;
143 /* Copies of flags for ControlPersist foreground slave */
144 int ostdin_null_flag
, ono_shell_flag
, otty_flag
, orequest_tty
;
147 * Flag indicating that ssh should fork after authentication. This is useful
148 * so that the passphrase can be entered manually, and then ssh goes to the
151 int fork_after_authentication_flag
= 0;
153 /* forward stdio to remote host and port */
154 char *stdio_forward_host
= NULL
;
155 int stdio_forward_port
= 0;
158 * General data structure for command line options and options configurable
159 * in configuration files. See readconf.h.
163 /* optional user configfile */
167 * Name of the host we are connecting to. This is the name given on the
168 * command line, or the HostName specified for the user-supplied name in a
169 * configuration file.
173 /* socket address the host resolves to */
174 struct sockaddr_storage hostaddr
;
176 /* Private host keys. */
177 Sensitive sensitive_data
;
179 /* Original real UID. */
180 uid_t original_real_uid
;
181 uid_t original_effective_uid
;
183 /* command to be executed */
186 /* Should we execute a command or invoke a subsystem? */
187 int subsystem_flag
= 0;
189 /* # of replies received for global requests */
190 static int remote_forward_confirms_received
= 0;
193 extern int muxserver_sock
;
194 extern u_int muxclient_command
;
196 /* Prints a help message to the user. This function never returns. */
202 "usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n"
203 " [-D [bind_address:]port] [-E log_file] [-e escape_char]\n"
204 " [-F configfile] [-I pkcs11] [-i identity_file]\n"
205 " [-L [bind_address:]port:host:hostport] [-l login_name] [-m mac_spec]\n"
206 " [-O ctl_cmd] [-o option] [-p port]\n"
207 " [-Q cipher | cipher-auth | mac | kex | key]\n"
208 " [-R [bind_address:]port:host:hostport] [-S ctl_path] [-W host:port]\n"
209 " [-w local_tun[:remote_tun]] [user@]hostname [command]\n"
214 static int ssh_session(void);
215 static int ssh_session2(void);
216 static void load_public_identity_files(void);
217 static void main_sigchld_handler(int);
219 /* from muxclient.c */
220 void muxclient(const char *);
221 void muxserver_listen(void);
223 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */
225 tilde_expand_paths(char **paths
, u_int num_paths
)
230 for (i
= 0; i
< num_paths
; i
++) {
231 cp
= tilde_expand_filename(paths
[i
], original_real_uid
);
238 * Attempt to resolve a host name / port to a set of addresses and
239 * optionally return any CNAMEs encountered along the way.
240 * Returns NULL on failure.
241 * NB. this function must operate with a options having undefined members.
243 static struct addrinfo
*
244 resolve_host(const char *name
, int port
, int logerr
, char *cname
, size_t clen
)
246 char strport
[NI_MAXSERV
];
247 struct addrinfo hints
, *res
;
248 int gaierr
, loglevel
= SYSLOG_LEVEL_DEBUG1
;
251 port
= default_ssh_port();
253 snprintf(strport
, sizeof strport
, "%u", port
);
254 memset(&hints
, 0, sizeof(hints
));
255 hints
.ai_family
= options
.address_family
== -1 ?
256 AF_UNSPEC
: options
.address_family
;
257 hints
.ai_socktype
= SOCK_STREAM
;
259 hints
.ai_flags
= AI_CANONNAME
;
260 if ((gaierr
= getaddrinfo(name
, strport
, &hints
, &res
)) != 0) {
261 if (logerr
|| (gaierr
!= EAI_NONAME
&& gaierr
!= EAI_NODATA
))
262 loglevel
= SYSLOG_LEVEL_ERROR
;
263 do_log2(loglevel
, "%s: Could not resolve hostname %.100s: %s",
264 __progname
, name
, ssh_gai_strerror(gaierr
));
267 if (cname
!= NULL
&& res
->ai_canonname
!= NULL
) {
268 if (strlcpy(cname
, res
->ai_canonname
, clen
) >= clen
) {
269 error("%s: host \"%s\" cname \"%s\" too long (max %lu)",
270 __func__
, name
, res
->ai_canonname
, (u_long
)clen
);
279 * Check whether the cname is a permitted replacement for the hostname
280 * and perform the replacement if it is.
281 * NB. this function must operate with a options having undefined members.
284 check_follow_cname(char **namep
, const char *cname
)
287 struct allowed_cname
*rule
;
289 if (*cname
== '\0' || options
.num_permitted_cnames
== 0 ||
290 strcmp(*namep
, cname
) == 0)
292 if (options
.canonicalize_hostname
== SSH_CANONICALISE_NO
)
295 * Don't attempt to canonicalize names that will be interpreted by
296 * a proxy unless the user specifically requests so.
298 if (!option_clear_or_none(options
.proxy_command
) &&
299 options
.canonicalize_hostname
!= SSH_CANONICALISE_ALWAYS
)
301 debug3("%s: check \"%s\" CNAME \"%s\"", __func__
, *namep
, cname
);
302 for (i
= 0; i
< options
.num_permitted_cnames
; i
++) {
303 rule
= options
.permitted_cnames
+ i
;
304 if (match_pattern_list(*namep
, rule
->source_list
,
305 strlen(rule
->source_list
), 1) != 1 ||
306 match_pattern_list(cname
, rule
->target_list
,
307 strlen(rule
->target_list
), 1) != 1)
309 verbose("Canonicalized DNS aliased hostname "
310 "\"%s\" => \"%s\"", *namep
, cname
);
312 *namep
= xstrdup(cname
);
319 * Attempt to resolve the supplied hostname after applying the user's
320 * canonicalization rules. Returns the address list for the host or NULL
321 * if no name was found after canonicalization.
322 * NB. this function must operate with a options having undefined members.
324 static struct addrinfo
*
325 resolve_canonicalize(char **hostp
, int port
)
328 char *cp
, *fullhost
, cname_target
[NI_MAXHOST
];
329 struct addrinfo
*addrs
;
331 if (options
.canonicalize_hostname
== SSH_CANONICALISE_NO
)
335 * Don't attempt to canonicalize names that will be interpreted by
336 * a proxy unless the user specifically requests so.
338 if (!option_clear_or_none(options
.proxy_command
) &&
339 options
.canonicalize_hostname
!= SSH_CANONICALISE_ALWAYS
)
342 /* Don't apply canonicalization to sufficiently-qualified hostnames */
344 for (cp
= *hostp
; *cp
!= '\0'; cp
++) {
348 if (ndots
> options
.canonicalize_max_dots
) {
349 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)",
350 __func__
, *hostp
, options
.canonicalize_max_dots
);
353 /* Attempt each supplied suffix */
354 for (i
= 0; i
< options
.num_canonical_domains
; i
++) {
355 *cname_target
= '\0';
356 xasprintf(&fullhost
, "%s.%s.", *hostp
,
357 options
.canonical_domains
[i
]);
358 debug3("%s: attempting \"%s\" => \"%s\"", __func__
,
360 if ((addrs
= resolve_host(fullhost
, port
, 0,
361 cname_target
, sizeof(cname_target
))) == NULL
) {
365 /* Remove trailing '.' */
366 fullhost
[strlen(fullhost
) - 1] = '\0';
367 /* Follow CNAME if requested */
368 if (!check_follow_cname(&fullhost
, cname_target
)) {
369 debug("Canonicalized hostname \"%s\" => \"%s\"",
376 if (!options
.canonicalize_fallback_local
)
377 fatal("%s: Could not resolve host \"%s\"", __progname
, *hostp
);
378 debug2("%s: host %s not found in any suffix", __func__
, *hostp
);
383 * Read per-user configuration file. Ignore the system wide config
384 * file if the user specifies a config file on the command line.
387 process_config_files(struct passwd
*pw
)
389 char buf
[MAXPATHLEN
];
392 if (config
!= NULL
) {
393 if (strcasecmp(config
, "none") != 0 &&
394 !read_config_file(config
, pw
, host
, &options
,
396 fatal("Can't open user config file %.100s: "
397 "%.100s", config
, strerror(errno
));
399 r
= snprintf(buf
, sizeof buf
, "%s/%s", pw
->pw_dir
,
400 _PATH_SSH_USER_CONFFILE
);
401 if (r
> 0 && (size_t)r
< sizeof(buf
))
402 (void)read_config_file(buf
, pw
, host
, &options
,
403 SSHCONF_CHECKPERM
|SSHCONF_USERCONF
);
405 /* Read systemwide configuration file after user config. */
406 (void)read_config_file(_PATH_HOST_CONFIG_FILE
, pw
, host
,
412 * Main program for the ssh client.
415 main(int ac
, char **av
)
417 int i
, r
, opt
, exit_status
, use_syslog
;
418 char *p
, *cp
, *line
, *argv0
, buf
[MAXPATHLEN
], *host_arg
, *logfile
;
419 char thishost
[NI_MAXHOST
], shorthost
[NI_MAXHOST
], portstr
[NI_MAXSERV
];
420 char cname
[NI_MAXHOST
];
424 extern int optind
, optreset
;
427 struct addrinfo
*addrs
= NULL
;
428 struct ssh_digest_ctx
*md
;
429 u_char conn_hash
[SSH_DIGEST_MAX_LENGTH
];
432 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
435 __progname
= ssh_get_progname(av
[0]);
437 #ifndef HAVE_SETPROCTITLE
438 /* Prepare for later setproctitle emulation */
439 /* Save argv so it isn't clobbered by setproctitle() emulation */
440 saved_av
= xcalloc(ac
+ 1, sizeof(*saved_av
));
441 for (i
= 0; i
< ac
; i
++)
442 saved_av
[i
] = xstrdup(av
[i
]);
444 compat_init_setproctitle(ac
, av
);
449 * Discard other fds that are hanging around. These can cause problem
450 * with backgrounded ssh processes started by ControlPersist.
452 closefrom(STDERR_FILENO
+ 1);
455 * Save the original real uid. It will be needed later (uid-swapping
456 * may clobber the real uid).
458 original_real_uid
= getuid();
459 original_effective_uid
= geteuid();
462 * Use uid-swapping to give up root privileges for the duration of
463 * option processing. We will re-instantiate the rights when we are
464 * ready to create the privileged port, and will permanently drop
465 * them when the port has been created (actually, when the connection
466 * has been made, as we may need to create the port several times).
470 #ifdef HAVE_SETRLIMIT
471 /* If we are installed setuid root be careful to not drop core. */
472 if (original_real_uid
!= original_effective_uid
) {
474 rlim
.rlim_cur
= rlim
.rlim_max
= 0;
475 if (setrlimit(RLIMIT_CORE
, &rlim
) < 0)
476 fatal("setrlimit failed: %.100s", strerror(errno
));
480 pw
= getpwuid(original_real_uid
);
482 logit("No user exists for uid %lu", (u_long
)original_real_uid
);
485 /* Take a copy of the returned structure. */
489 * Set our umask to something reasonable, as some files are created
490 * with the default umask. This will make them world-readable but
491 * writable only by the owner, which is ok for all files for which we
492 * don't set the modes explicitly.
497 * Initialize option structure to indicate that no values have been
500 initialize_options(&options
);
502 /* Parse command-line arguments. */
509 while ((opt
= getopt(ac
, av
, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
510 "ACD:E:F:I:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) {
513 options
.protocol
= SSH_PROTO_1
;
516 options
.protocol
= SSH_PROTO_2
;
519 options
.address_family
= AF_INET
;
522 options
.address_family
= AF_INET6
;
528 fork_after_authentication_flag
= 1;
532 options
.forward_x11
= 0;
535 options
.forward_x11
= 1;
541 logfile
= xstrdup(optarg
);
544 options
.forward_x11
= 1;
545 options
.forward_x11_trusted
= 1;
548 options
.fwd_opts
.gateway_ports
= 1;
551 if (stdio_forward_host
!= NULL
)
552 fatal("Cannot specify multiplexing "
554 else if (muxclient_command
!= 0)
555 fatal("Multiplexing command already specified");
556 if (strcmp(optarg
, "check") == 0)
557 muxclient_command
= SSHMUX_COMMAND_ALIVE_CHECK
;
558 else if (strcmp(optarg
, "forward") == 0)
559 muxclient_command
= SSHMUX_COMMAND_FORWARD
;
560 else if (strcmp(optarg
, "exit") == 0)
561 muxclient_command
= SSHMUX_COMMAND_TERMINATE
;
562 else if (strcmp(optarg
, "stop") == 0)
563 muxclient_command
= SSHMUX_COMMAND_STOP
;
564 else if (strcmp(optarg
, "cancel") == 0)
565 muxclient_command
= SSHMUX_COMMAND_CANCEL_FWD
;
567 fatal("Invalid multiplex command.");
569 case 'P': /* deprecated */
570 options
.use_privileged_port
= 0;
574 if (strcmp(optarg
, "cipher") == 0)
575 cp
= cipher_alg_list('\n', 0);
576 else if (strcmp(optarg
, "cipher-auth") == 0)
577 cp
= cipher_alg_list('\n', 1);
578 else if (strcmp(optarg
, "mac") == 0)
579 cp
= mac_alg_list('\n');
580 else if (strcmp(optarg
, "kex") == 0)
581 cp
= kex_alg_list('\n');
582 else if (strcmp(optarg
, "key") == 0)
583 cp
= key_alg_list(0, 0);
584 else if (strcmp(optarg
, "key-cert") == 0)
585 cp
= key_alg_list(1, 0);
586 else if (strcmp(optarg
, "key-plain") == 0)
587 cp
= key_alg_list(0, 1);
589 fatal("Unsupported query \"%s\"", optarg
);
595 options
.forward_agent
= 0;
598 options
.forward_agent
= 1;
601 options
.gss_deleg_creds
= 0;
604 options
.gss_authentication
= 1;
605 options
.gss_deleg_creds
= 1;
608 if (stat(optarg
, &st
) < 0) {
609 fprintf(stderr
, "Warning: Identity file %s "
610 "not accessible: %s.\n", optarg
,
614 add_identity_file(&options
, NULL
, optarg
, 1);
618 options
.pkcs11_provider
= xstrdup(optarg
);
620 fprintf(stderr
, "no support for PKCS#11.\n");
624 if (options
.request_tty
== REQUEST_TTY_YES
)
625 options
.request_tty
= REQUEST_TTY_FORCE
;
627 options
.request_tty
= REQUEST_TTY_YES
;
630 if (debug_flag
== 0) {
632 options
.log_level
= SYSLOG_LEVEL_DEBUG1
;
634 if (options
.log_level
< SYSLOG_LEVEL_DEBUG3
)
639 fprintf(stderr
, "%s, %s\n",
642 SSLeay_version(SSLEAY_VERSION
)
651 if (options
.tun_open
== -1)
652 options
.tun_open
= SSH_TUNMODE_DEFAULT
;
653 options
.tun_local
= a2tun(optarg
, &options
.tun_remote
);
654 if (options
.tun_local
== SSH_TUNID_ERR
) {
656 "Bad tun device '%s'\n", optarg
);
661 if (stdio_forward_host
!= NULL
)
662 fatal("stdio forward already specified");
663 if (muxclient_command
!= 0)
664 fatal("Cannot specify stdio forward with -O");
665 if (parse_forward(&fwd
, optarg
, 1, 0)) {
666 stdio_forward_host
= fwd
.listen_host
;
667 stdio_forward_port
= fwd
.listen_port
;
668 free(fwd
.connect_host
);
671 "Bad stdio forwarding specification '%s'\n",
675 options
.request_tty
= REQUEST_TTY_NO
;
677 options
.clear_forwardings
= 1;
678 options
.exit_on_forward_failure
= 1;
681 options
.log_level
= SYSLOG_LEVEL_QUIET
;
684 if (optarg
[0] == '^' && optarg
[2] == 0 &&
685 (u_char
) optarg
[1] >= 64 &&
686 (u_char
) optarg
[1] < 128)
687 options
.escape_char
= (u_char
) optarg
[1] & 31;
688 else if (strlen(optarg
) == 1)
689 options
.escape_char
= (u_char
) optarg
[0];
690 else if (strcmp(optarg
, "none") == 0)
691 options
.escape_char
= SSH_ESCAPECHAR_NONE
;
693 fprintf(stderr
, "Bad escape character '%s'.\n",
699 if (ciphers_valid(optarg
)) {
701 options
.ciphers
= xstrdup(optarg
);
702 options
.cipher
= SSH_CIPHER_INVALID
;
705 options
.cipher
= cipher_number(optarg
);
706 if (options
.cipher
== -1) {
708 "Unknown cipher type '%s'\n",
712 if (options
.cipher
== SSH_CIPHER_3DES
)
713 options
.ciphers
= "3des-cbc";
714 else if (options
.cipher
== SSH_CIPHER_BLOWFISH
)
715 options
.ciphers
= "blowfish-cbc";
717 options
.ciphers
= (char *)-1;
721 if (mac_valid(optarg
))
722 options
.macs
= xstrdup(optarg
);
724 fprintf(stderr
, "Unknown mac type '%s'\n",
730 if (options
.control_master
== SSHCTL_MASTER_YES
)
731 options
.control_master
= SSHCTL_MASTER_ASK
;
733 options
.control_master
= SSHCTL_MASTER_YES
;
736 options
.port
= a2port(optarg
);
737 if (options
.port
<= 0) {
738 fprintf(stderr
, "Bad port '%s'\n", optarg
);
743 options
.user
= optarg
;
747 if (parse_forward(&fwd
, optarg
, 0, 0))
748 add_local_forward(&options
, &fwd
);
751 "Bad local forwarding specification '%s'\n",
758 if (parse_forward(&fwd
, optarg
, 0, 1)) {
759 add_remote_forward(&options
, &fwd
);
762 "Bad remote forwarding specification "
769 if (parse_forward(&fwd
, optarg
, 1, 0)) {
770 add_local_forward(&options
, &fwd
);
773 "Bad dynamic forwarding specification "
780 options
.compression
= 1;
784 options
.request_tty
= REQUEST_TTY_NO
;
787 options
.request_tty
= REQUEST_TTY_NO
;
790 line
= xstrdup(optarg
);
791 if (process_config_line(&options
, pw
, host
? host
: "",
792 line
, "command-line", 0, NULL
, SSHCONF_USERCONF
)
801 if (options
.control_path
!= NULL
)
802 free(options
.control_path
);
803 options
.control_path
= xstrdup(optarg
);
806 options
.bind_address
= optarg
;
819 if (ac
> 0 && !host
) {
820 if (strrchr(*av
, '@')) {
822 cp
= strrchr(p
, '@');
823 if (cp
== NULL
|| cp
== p
)
827 host
= xstrdup(++cp
);
831 optind
= optreset
= 1;
837 /* Check that we got a host name. */
841 host_arg
= xstrdup(host
);
844 OpenSSL_add_all_algorithms();
845 ERR_load_crypto_strings();
848 /* Initialize the command to execute on remote host. */
849 buffer_init(&command
);
852 * Save the command to execute on the remote host in a buffer. There
853 * is no limit on the length of the command, except by the maximum
854 * packet size. Also sets the tty flag if there is no command.
857 /* No command specified - execute shell on a tty. */
858 if (subsystem_flag
) {
860 "You must specify a subsystem to invoke.\n");
864 /* A command has been specified. Store it into the buffer. */
865 for (i
= 0; i
< ac
; i
++) {
867 buffer_append(&command
, " ", 1);
868 buffer_append(&command
, av
[i
], strlen(av
[i
]));
872 /* Cannot fork to background if no command. */
873 if (fork_after_authentication_flag
&& buffer_len(&command
) == 0 &&
875 fatal("Cannot fork into background without a command "
879 * Initialize "log" output. Since we are the client all output
880 * goes to stderr unless otherwise specified by -y or -E.
882 if (use_syslog
&& logfile
!= NULL
)
883 fatal("Can't specify both -y and -E");
884 if (logfile
!= NULL
) {
885 log_redirect_stderr_to(logfile
);
889 options
.log_level
== -1 ? SYSLOG_LEVEL_INFO
: options
.log_level
,
890 SYSLOG_FACILITY_USER
, !use_syslog
);
893 logit("%s, %s", SSH_RELEASE
,
895 SSLeay_version(SSLEAY_VERSION
)
901 /* Parse the configuration files */
902 process_config_files(pw
);
904 /* Hostname canonicalisation needs a few options filled. */
905 fill_default_options_for_canonicalization(&options
);
907 /* If the user has replaced the hostname then take it into use now */
908 if (options
.hostname
!= NULL
) {
909 /* NB. Please keep in sync with readconf.c:match_cfg_line() */
910 cp
= percent_expand(options
.hostname
,
911 "h", host
, (char *)NULL
);
916 /* If canonicalization requested then try to apply it */
918 if (options
.canonicalize_hostname
!= SSH_CANONICALISE_NO
)
919 addrs
= resolve_canonicalize(&host
, options
.port
);
922 * If CanonicalizePermittedCNAMEs have been specified but
923 * other canonicalization did not happen (by not being requested
924 * or by failing with fallback) then the hostname may still be changed
925 * as a result of CNAME following.
927 * Try to resolve the bare hostname name using the system resolver's
928 * usual search rules and then apply the CNAME follow rules.
930 * Skip the lookup if a ProxyCommand is being used unless the user
931 * has specifically requested canonicalisation for this case via
932 * CanonicalizeHostname=always
934 if (addrs
== NULL
&& options
.num_permitted_cnames
!= 0 &&
935 (option_clear_or_none(options
.proxy_command
) ||
936 options
.canonicalize_hostname
== SSH_CANONICALISE_ALWAYS
)) {
937 if ((addrs
= resolve_host(host
, options
.port
,
938 option_clear_or_none(options
.proxy_command
),
939 cname
, sizeof(cname
))) == NULL
) {
940 /* Don't fatal proxied host names not in the DNS */
941 if (option_clear_or_none(options
.proxy_command
))
942 cleanup_exit(255); /* logged in resolve_host */
944 check_follow_cname(&host
, cname
);
948 * If the target hostname has changed as a result of canonicalisation
949 * then re-parse the configuration files as new stanzas may match.
951 if (strcasecmp(host_arg
, host
) != 0) {
952 debug("Hostname has changed; re-reading configuration");
953 process_config_files(pw
);
956 /* Fill configuration defaults. */
957 fill_default_options(&options
);
959 if (options
.port
== 0)
960 options
.port
= default_ssh_port();
961 channel_set_af(options
.address_family
);
963 /* Tidy and check options */
964 if (options
.host_key_alias
!= NULL
)
965 lowercase(options
.host_key_alias
);
966 if (options
.proxy_command
!= NULL
&&
967 strcmp(options
.proxy_command
, "-") == 0 &&
968 options
.proxy_use_fdpass
)
969 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible");
971 if (original_effective_uid
!= 0)
972 options
.use_privileged_port
= 0;
976 log_init(argv0
, options
.log_level
, SYSLOG_FACILITY_USER
, !use_syslog
);
978 if (options
.request_tty
== REQUEST_TTY_YES
||
979 options
.request_tty
== REQUEST_TTY_FORCE
)
982 /* Allocate a tty by default if no command specified. */
983 if (buffer_len(&command
) == 0)
984 tty_flag
= options
.request_tty
!= REQUEST_TTY_NO
;
987 if (options
.request_tty
== REQUEST_TTY_NO
|| muxclient_command
!= 0)
989 /* Do not allocate a tty if stdin is not a tty. */
990 if ((!isatty(fileno(stdin
)) || stdin_null_flag
) &&
991 options
.request_tty
!= REQUEST_TTY_FORCE
) {
993 logit("Pseudo-terminal will not be allocated because "
994 "stdin is not a terminal.");
1000 if (options
.user
== NULL
)
1001 options
.user
= xstrdup(pw
->pw_name
);
1003 if (gethostname(thishost
, sizeof(thishost
)) == -1)
1004 fatal("gethostname: %s", strerror(errno
));
1005 strlcpy(shorthost
, thishost
, sizeof(shorthost
));
1006 shorthost
[strcspn(thishost
, ".")] = '\0';
1007 snprintf(portstr
, sizeof(portstr
), "%d", options
.port
);
1009 if ((md
= ssh_digest_start(SSH_DIGEST_SHA1
)) == NULL
||
1010 ssh_digest_update(md
, thishost
, strlen(thishost
)) < 0 ||
1011 ssh_digest_update(md
, host
, strlen(host
)) < 0 ||
1012 ssh_digest_update(md
, portstr
, strlen(portstr
)) < 0 ||
1013 ssh_digest_update(md
, options
.user
, strlen(options
.user
)) < 0 ||
1014 ssh_digest_final(md
, conn_hash
, sizeof(conn_hash
)) < 0)
1015 fatal("%s: mux digest failed", __func__
);
1016 ssh_digest_free(md
);
1017 conn_hash_hex
= tohex(conn_hash
, ssh_digest_bytes(SSH_DIGEST_SHA1
));
1019 if (options
.local_command
!= NULL
) {
1020 debug3("expanding LocalCommand: %s", options
.local_command
);
1021 cp
= options
.local_command
;
1022 options
.local_command
= percent_expand(cp
,
1033 debug3("expanded LocalCommand: %s", options
.local_command
);
1037 if (options
.control_path
!= NULL
) {
1038 cp
= tilde_expand_filename(options
.control_path
,
1040 free(options
.control_path
);
1041 options
.control_path
= percent_expand(cp
,
1053 free(conn_hash_hex
);
1055 if (muxclient_command
!= 0 && options
.control_path
== NULL
)
1056 fatal("No ControlPath specified for \"-O\" command");
1057 if (options
.control_path
!= NULL
)
1058 muxclient(options
.control_path
);
1061 * If hostname canonicalisation was not enabled, then we may not
1062 * have yet resolved the hostname. Do so now.
1064 if (addrs
== NULL
&& options
.proxy_command
== NULL
) {
1065 if ((addrs
= resolve_host(host
, options
.port
, 1,
1066 cname
, sizeof(cname
))) == NULL
)
1067 cleanup_exit(255); /* resolve_host logs the error */
1070 timeout_ms
= options
.connection_timeout
* 1000;
1072 /* Open a connection to the remote host. */
1073 if (ssh_connect(host
, addrs
, &hostaddr
, options
.port
,
1074 options
.address_family
, options
.connection_attempts
,
1075 &timeout_ms
, options
.tcp_keep_alive
,
1076 options
.use_privileged_port
) != 0)
1080 freeaddrinfo(addrs
);
1082 packet_set_timeout(options
.server_alive_interval
,
1083 options
.server_alive_count_max
);
1086 debug3("timeout: %d ms remain after connect", timeout_ms
);
1089 * If we successfully made the connection, load the host private key
1090 * in case we will need it later for combined rsa-rhosts
1091 * authentication. This must be done before releasing extra
1092 * privileges, because the file is only readable by root.
1093 * If we cannot access the private keys, load the public keys
1094 * instead and try to execute the ssh-keysign helper instead.
1096 sensitive_data
.nkeys
= 0;
1097 sensitive_data
.keys
= NULL
;
1098 sensitive_data
.external_keysign
= 0;
1099 if (options
.rhosts_rsa_authentication
||
1100 options
.hostbased_authentication
) {
1101 sensitive_data
.nkeys
= 9;
1102 sensitive_data
.keys
= xcalloc(sensitive_data
.nkeys
,
1104 for (i
= 0; i
< sensitive_data
.nkeys
; i
++)
1105 sensitive_data
.keys
[i
] = NULL
;
1108 sensitive_data
.keys
[0] = key_load_private_type(KEY_RSA1
,
1109 _PATH_HOST_KEY_FILE
, "", NULL
, NULL
);
1110 sensitive_data
.keys
[1] = key_load_private_cert(KEY_DSA
,
1111 _PATH_HOST_DSA_KEY_FILE
, "", NULL
);
1112 #ifdef OPENSSL_HAS_ECC
1113 sensitive_data
.keys
[2] = key_load_private_cert(KEY_ECDSA
,
1114 _PATH_HOST_ECDSA_KEY_FILE
, "", NULL
);
1116 sensitive_data
.keys
[3] = key_load_private_cert(KEY_RSA
,
1117 _PATH_HOST_RSA_KEY_FILE
, "", NULL
);
1118 sensitive_data
.keys
[4] = key_load_private_cert(KEY_ED25519
,
1119 _PATH_HOST_ED25519_KEY_FILE
, "", NULL
);
1120 sensitive_data
.keys
[5] = key_load_private_type(KEY_DSA
,
1121 _PATH_HOST_DSA_KEY_FILE
, "", NULL
, NULL
);
1122 #ifdef OPENSSL_HAS_ECC
1123 sensitive_data
.keys
[6] = key_load_private_type(KEY_ECDSA
,
1124 _PATH_HOST_ECDSA_KEY_FILE
, "", NULL
, NULL
);
1126 sensitive_data
.keys
[7] = key_load_private_type(KEY_RSA
,
1127 _PATH_HOST_RSA_KEY_FILE
, "", NULL
, NULL
);
1128 sensitive_data
.keys
[8] = key_load_private_type(KEY_ED25519
,
1129 _PATH_HOST_ED25519_KEY_FILE
, "", NULL
, NULL
);
1132 if (options
.hostbased_authentication
== 1 &&
1133 sensitive_data
.keys
[0] == NULL
&&
1134 sensitive_data
.keys
[5] == NULL
&&
1135 sensitive_data
.keys
[6] == NULL
&&
1136 sensitive_data
.keys
[7] == NULL
&&
1137 sensitive_data
.keys
[8] == NULL
) {
1138 sensitive_data
.keys
[1] = key_load_cert(
1139 _PATH_HOST_DSA_KEY_FILE
);
1140 #ifdef OPENSSL_HAS_ECC
1141 sensitive_data
.keys
[2] = key_load_cert(
1142 _PATH_HOST_ECDSA_KEY_FILE
);
1144 sensitive_data
.keys
[3] = key_load_cert(
1145 _PATH_HOST_RSA_KEY_FILE
);
1146 sensitive_data
.keys
[4] = key_load_cert(
1147 _PATH_HOST_ED25519_KEY_FILE
);
1148 sensitive_data
.keys
[5] = key_load_public(
1149 _PATH_HOST_DSA_KEY_FILE
, NULL
);
1150 #ifdef OPENSSL_HAS_ECC
1151 sensitive_data
.keys
[6] = key_load_public(
1152 _PATH_HOST_ECDSA_KEY_FILE
, NULL
);
1154 sensitive_data
.keys
[7] = key_load_public(
1155 _PATH_HOST_RSA_KEY_FILE
, NULL
);
1156 sensitive_data
.keys
[8] = key_load_public(
1157 _PATH_HOST_ED25519_KEY_FILE
, NULL
);
1158 sensitive_data
.external_keysign
= 1;
1162 * Get rid of any extra privileges that we may have. We will no
1163 * longer need them. Also, extra privileges could make it very hard
1164 * to read identity files and other non-world-readable files from the
1165 * user's home directory if it happens to be on a NFS volume where
1166 * root is mapped to nobody.
1168 if (original_effective_uid
== 0) {
1170 permanently_set_uid(pw
);
1174 * Now that we are back to our own permissions, create ~/.ssh
1175 * directory if it doesn't already exist.
1177 if (config
== NULL
) {
1178 r
= snprintf(buf
, sizeof buf
, "%s%s%s", pw
->pw_dir
,
1179 strcmp(pw
->pw_dir
, "/") ? "/" : "", _PATH_SSH_USER_DIR
);
1180 if (r
> 0 && (size_t)r
< sizeof(buf
) && stat(buf
, &st
) < 0) {
1182 ssh_selinux_setfscreatecon(buf
);
1184 if (mkdir(buf
, 0700) < 0)
1185 error("Could not create directory '%.200s'.",
1188 ssh_selinux_setfscreatecon(NULL
);
1192 /* load options.identity_files */
1193 load_public_identity_files();
1195 /* Expand ~ in known host file names. */
1196 tilde_expand_paths(options
.system_hostfiles
,
1197 options
.num_system_hostfiles
);
1198 tilde_expand_paths(options
.user_hostfiles
, options
.num_user_hostfiles
);
1200 signal(SIGPIPE
, SIG_IGN
); /* ignore SIGPIPE early */
1201 signal(SIGCHLD
, main_sigchld_handler
);
1203 /* Log into the remote system. Never returns if the login fails. */
1204 ssh_login(&sensitive_data
, host
, (struct sockaddr
*)&hostaddr
,
1205 options
.port
, pw
, timeout_ms
);
1207 if (packet_connection_is_on_socket()) {
1208 verbose("Authenticated to %s ([%s]:%d).", host
,
1209 get_remote_ipaddr(), get_remote_port());
1211 verbose("Authenticated to %s (via proxy).", host
);
1214 /* We no longer need the private host keys. Clear them now. */
1215 if (sensitive_data
.nkeys
!= 0) {
1216 for (i
= 0; i
< sensitive_data
.nkeys
; i
++) {
1217 if (sensitive_data
.keys
[i
] != NULL
) {
1218 /* Destroys contents safely */
1219 debug3("clear hostkey %d", i
);
1220 key_free(sensitive_data
.keys
[i
]);
1221 sensitive_data
.keys
[i
] = NULL
;
1224 free(sensitive_data
.keys
);
1226 for (i
= 0; i
< options
.num_identity_files
; i
++) {
1227 free(options
.identity_files
[i
]);
1228 options
.identity_files
[i
] = NULL
;
1229 if (options
.identity_keys
[i
]) {
1230 key_free(options
.identity_keys
[i
]);
1231 options
.identity_keys
[i
] = NULL
;
1235 exit_status
= compat20
? ssh_session2() : ssh_session();
1238 if (options
.control_path
!= NULL
&& muxserver_sock
!= -1)
1239 unlink(options
.control_path
);
1241 /* Kill ProxyCommand if it is running. */
1242 ssh_kill_proxy_command();
1248 control_persist_detach(void)
1253 debug("%s: backgrounding master process", __func__
);
1256 * master (current process) into the background, and make the
1257 * foreground process a client of the backgrounded master.
1259 switch ((pid
= fork())) {
1261 fatal("%s: fork: %s", __func__
, strerror(errno
));
1263 /* Child: master process continues mainloop */
1266 /* Parent: set up mux slave to connect to backgrounded master */
1267 debug2("%s: background process is %ld", __func__
, (long)pid
);
1268 stdin_null_flag
= ostdin_null_flag
;
1269 options
.request_tty
= orequest_tty
;
1270 tty_flag
= otty_flag
;
1271 close(muxserver_sock
);
1272 muxserver_sock
= -1;
1273 options
.control_master
= SSHCTL_MASTER_NO
;
1274 muxclient(options
.control_path
);
1275 /* muxclient() doesn't return on success. */
1276 fatal("Failed to connect to new control master");
1278 if ((devnull
= open(_PATH_DEVNULL
, O_RDWR
)) == -1) {
1279 error("%s: open(\"/dev/null\"): %s", __func__
,
1282 if (dup2(devnull
, STDIN_FILENO
) == -1 ||
1283 dup2(devnull
, STDOUT_FILENO
) == -1)
1284 error("%s: dup2: %s", __func__
, strerror(errno
));
1285 if (devnull
> STDERR_FILENO
)
1289 setproctitle("%s [mux]", options
.control_path
);
1292 /* Do fork() after authentication. Used by "ssh -f" */
1296 if (need_controlpersist_detach
)
1297 control_persist_detach();
1298 debug("forking to background");
1299 fork_after_authentication_flag
= 0;
1300 if (daemon(1, 1) < 0)
1301 fatal("daemon() failed: %.200s", strerror(errno
));
1304 /* Callback for remote forward global requests */
1306 ssh_confirm_remote_forward(int type
, u_int32_t seq
, void *ctxt
)
1308 struct Forward
*rfwd
= (struct Forward
*)ctxt
;
1310 /* XXX verbose() on failure? */
1311 debug("remote forward %s for: listen %s%s%d, connect %s:%d",
1312 type
== SSH2_MSG_REQUEST_SUCCESS
? "success" : "failure",
1313 rfwd
->listen_path
? rfwd
->listen_path
:
1314 rfwd
->listen_host
? rfwd
->listen_host
: "",
1315 (rfwd
->listen_path
|| rfwd
->listen_host
) ? ":" : "",
1316 rfwd
->listen_port
, rfwd
->connect_path
? rfwd
->connect_path
:
1317 rfwd
->connect_host
, rfwd
->connect_port
);
1318 if (rfwd
->listen_path
== NULL
&& rfwd
->listen_port
== 0) {
1319 if (type
== SSH2_MSG_REQUEST_SUCCESS
) {
1320 rfwd
->allocated_port
= packet_get_int();
1321 logit("Allocated port %u for remote forward to %s:%d",
1322 rfwd
->allocated_port
,
1323 rfwd
->connect_host
, rfwd
->connect_port
);
1324 channel_update_permitted_opens(rfwd
->handle
,
1325 rfwd
->allocated_port
);
1327 channel_update_permitted_opens(rfwd
->handle
, -1);
1331 if (type
== SSH2_MSG_REQUEST_FAILURE
) {
1332 if (options
.exit_on_forward_failure
) {
1333 if (rfwd
->listen_path
!= NULL
)
1334 fatal("Error: remote port forwarding failed "
1335 "for listen path %s", rfwd
->listen_path
);
1337 fatal("Error: remote port forwarding failed "
1338 "for listen port %d", rfwd
->listen_port
);
1340 if (rfwd
->listen_path
!= NULL
)
1341 logit("Warning: remote port forwarding failed "
1342 "for listen path %s", rfwd
->listen_path
);
1344 logit("Warning: remote port forwarding failed "
1345 "for listen port %d", rfwd
->listen_port
);
1348 if (++remote_forward_confirms_received
== options
.num_remote_forwards
) {
1349 debug("All remote forwarding requests processed");
1350 if (fork_after_authentication_flag
)
1356 client_cleanup_stdio_fwd(int id
, void *arg
)
1358 debug("stdio forwarding: done");
1363 ssh_stdio_confirm(int id
, int success
, void *arg
)
1366 fatal("stdio forwarding failed");
1370 ssh_init_stdio_forwarding(void)
1375 if (stdio_forward_host
== NULL
)
1378 fatal("stdio forwarding require Protocol 2");
1380 debug3("%s: %s:%d", __func__
, stdio_forward_host
, stdio_forward_port
);
1382 if ((in
= dup(STDIN_FILENO
)) < 0 ||
1383 (out
= dup(STDOUT_FILENO
)) < 0)
1384 fatal("channel_connect_stdio_fwd: dup() in/out failed");
1385 if ((c
= channel_connect_stdio_fwd(stdio_forward_host
,
1386 stdio_forward_port
, in
, out
)) == NULL
)
1387 fatal("%s: channel_connect_stdio_fwd failed", __func__
);
1388 channel_register_cleanup(c
->self
, client_cleanup_stdio_fwd
, 0);
1389 channel_register_open_confirm(c
->self
, ssh_stdio_confirm
, NULL
);
1393 ssh_init_forwarding(void)
1398 /* Initiate local TCP/IP port forwardings. */
1399 for (i
= 0; i
< options
.num_local_forwards
; i
++) {
1400 debug("Local connections to %.200s:%d forwarded to remote "
1401 "address %.200s:%d",
1402 (options
.local_forwards
[i
].listen_path
!= NULL
) ?
1403 options
.local_forwards
[i
].listen_path
:
1404 (options
.local_forwards
[i
].listen_host
== NULL
) ?
1405 (options
.fwd_opts
.gateway_ports
? "*" : "LOCALHOST") :
1406 options
.local_forwards
[i
].listen_host
,
1407 options
.local_forwards
[i
].listen_port
,
1408 (options
.local_forwards
[i
].connect_path
!= NULL
) ?
1409 options
.local_forwards
[i
].connect_path
:
1410 options
.local_forwards
[i
].connect_host
,
1411 options
.local_forwards
[i
].connect_port
);
1412 success
+= channel_setup_local_fwd_listener(
1413 &options
.local_forwards
[i
], &options
.fwd_opts
);
1415 if (i
> 0 && success
!= i
&& options
.exit_on_forward_failure
)
1416 fatal("Could not request local forwarding.");
1417 if (i
> 0 && success
== 0)
1418 error("Could not request local forwarding.");
1420 /* Initiate remote TCP/IP port forwardings. */
1421 for (i
= 0; i
< options
.num_remote_forwards
; i
++) {
1422 debug("Remote connections from %.200s:%d forwarded to "
1423 "local address %.200s:%d",
1424 (options
.remote_forwards
[i
].listen_path
!= NULL
) ?
1425 options
.remote_forwards
[i
].listen_path
:
1426 (options
.remote_forwards
[i
].listen_host
== NULL
) ?
1427 "LOCALHOST" : options
.remote_forwards
[i
].listen_host
,
1428 options
.remote_forwards
[i
].listen_port
,
1429 (options
.remote_forwards
[i
].connect_path
!= NULL
) ?
1430 options
.remote_forwards
[i
].connect_path
:
1431 options
.remote_forwards
[i
].connect_host
,
1432 options
.remote_forwards
[i
].connect_port
);
1433 options
.remote_forwards
[i
].handle
=
1434 channel_request_remote_forwarding(
1435 &options
.remote_forwards
[i
]);
1436 if (options
.remote_forwards
[i
].handle
< 0) {
1437 if (options
.exit_on_forward_failure
)
1438 fatal("Could not request remote forwarding.");
1440 logit("Warning: Could not request remote "
1443 client_register_global_confirm(ssh_confirm_remote_forward
,
1444 &options
.remote_forwards
[i
]);
1448 /* Initiate tunnel forwarding. */
1449 if (options
.tun_open
!= SSH_TUNMODE_NO
) {
1450 if (client_request_tun_fwd(options
.tun_open
,
1451 options
.tun_local
, options
.tun_remote
) == -1) {
1452 if (options
.exit_on_forward_failure
)
1453 fatal("Could not request tunnel forwarding.");
1455 error("Could not request tunnel forwarding.");
1461 check_agent_present(void)
1463 if (options
.forward_agent
) {
1464 /* Clear agent forwarding if we don't have an agent. */
1465 if (!ssh_agent_present())
1466 options
.forward_agent
= 0;
1474 int interactive
= 0;
1478 const char *display
;
1480 /* Enable compression if requested. */
1481 if (options
.compression
) {
1482 debug("Requesting compression at level %d.",
1483 options
.compression_level
);
1485 if (options
.compression_level
< 1 ||
1486 options
.compression_level
> 9)
1487 fatal("Compression level must be from 1 (fast) to "
1490 /* Send the request. */
1491 packet_start(SSH_CMSG_REQUEST_COMPRESSION
);
1492 packet_put_int(options
.compression_level
);
1494 packet_write_wait();
1495 type
= packet_read();
1496 if (type
== SSH_SMSG_SUCCESS
)
1497 packet_start_compression(options
.compression_level
);
1498 else if (type
== SSH_SMSG_FAILURE
)
1499 logit("Warning: Remote host refused compression.");
1501 packet_disconnect("Protocol error waiting for "
1502 "compression response.");
1504 /* Allocate a pseudo tty if appropriate. */
1506 debug("Requesting pty.");
1508 /* Start the packet. */
1509 packet_start(SSH_CMSG_REQUEST_PTY
);
1511 /* Store TERM in the packet. There is no limit on the
1512 length of the string. */
1513 cp
= getenv("TERM");
1516 packet_put_cstring(cp
);
1518 /* Store window size in the packet. */
1519 if (ioctl(fileno(stdin
), TIOCGWINSZ
, &ws
) < 0)
1520 memset(&ws
, 0, sizeof(ws
));
1521 packet_put_int((u_int
)ws
.ws_row
);
1522 packet_put_int((u_int
)ws
.ws_col
);
1523 packet_put_int((u_int
)ws
.ws_xpixel
);
1524 packet_put_int((u_int
)ws
.ws_ypixel
);
1526 /* Store tty modes in the packet. */
1527 tty_make_modes(fileno(stdin
), NULL
);
1529 /* Send the packet, and wait for it to leave. */
1531 packet_write_wait();
1533 /* Read response from the server. */
1534 type
= packet_read();
1535 if (type
== SSH_SMSG_SUCCESS
) {
1538 } else if (type
== SSH_SMSG_FAILURE
)
1539 logit("Warning: Remote host failed or refused to "
1540 "allocate a pseudo tty.");
1542 packet_disconnect("Protocol error waiting for pty "
1543 "request response.");
1545 /* Request X11 forwarding if enabled and DISPLAY is set. */
1546 display
= getenv("DISPLAY");
1547 if (options
.forward_x11
&& display
!= NULL
) {
1549 /* Get reasonable local authentication information. */
1550 client_x11_get_proto(display
, options
.xauth_location
,
1551 options
.forward_x11_trusted
,
1552 options
.forward_x11_timeout
,
1554 /* Request forwarding with authentication spoofing. */
1555 debug("Requesting X11 forwarding with authentication "
1557 x11_request_forwarding_with_spoofing(0, display
, proto
,
1559 /* Read response from the server. */
1560 type
= packet_read();
1561 if (type
== SSH_SMSG_SUCCESS
) {
1563 } else if (type
== SSH_SMSG_FAILURE
) {
1564 logit("Warning: Remote host denied X11 forwarding.");
1566 packet_disconnect("Protocol error waiting for X11 "
1570 /* Tell the packet module whether this is an interactive session. */
1571 packet_set_interactive(interactive
,
1572 options
.ip_qos_interactive
, options
.ip_qos_bulk
);
1574 /* Request authentication agent forwarding if appropriate. */
1575 check_agent_present();
1577 if (options
.forward_agent
) {
1578 debug("Requesting authentication agent forwarding.");
1579 auth_request_forwarding();
1581 /* Read response from the server. */
1582 type
= packet_read();
1584 if (type
!= SSH_SMSG_SUCCESS
)
1585 logit("Warning: Remote host denied authentication agent forwarding.");
1588 /* Initiate port forwardings. */
1589 ssh_init_stdio_forwarding();
1590 ssh_init_forwarding();
1592 /* Execute a local command */
1593 if (options
.local_command
!= NULL
&&
1594 options
.permit_local_command
)
1595 ssh_local_cmd(options
.local_command
);
1598 * If requested and we are not interested in replies to remote
1599 * forwarding requests, then let ssh continue in the background.
1601 if (fork_after_authentication_flag
) {
1602 if (options
.exit_on_forward_failure
&&
1603 options
.num_remote_forwards
> 0) {
1604 debug("deferring postauth fork until remote forward "
1605 "confirmation received");
1611 * If a command was specified on the command line, execute the
1612 * command now. Otherwise request the server to start a shell.
1614 if (buffer_len(&command
) > 0) {
1615 int len
= buffer_len(&command
);
1618 debug("Sending command: %.*s", len
,
1619 (u_char
*)buffer_ptr(&command
));
1620 packet_start(SSH_CMSG_EXEC_CMD
);
1621 packet_put_string(buffer_ptr(&command
), buffer_len(&command
));
1623 packet_write_wait();
1625 debug("Requesting shell.");
1626 packet_start(SSH_CMSG_EXEC_SHELL
);
1628 packet_write_wait();
1631 /* Enter the interactive session. */
1632 return client_loop(have_tty
, tty_flag
?
1633 options
.escape_char
: SSH_ESCAPECHAR_NONE
, 0);
1636 /* request pty/x11/agent/tcpfwd/shell for channel */
1638 ssh_session2_setup(int id
, int success
, void *arg
)
1640 extern char **environ
;
1641 const char *display
;
1642 int interactive
= tty_flag
;
1645 return; /* No need for error message, channels code sens one */
1647 display
= getenv("DISPLAY");
1648 if (options
.forward_x11
&& display
!= NULL
) {
1650 /* Get reasonable local authentication information. */
1651 client_x11_get_proto(display
, options
.xauth_location
,
1652 options
.forward_x11_trusted
,
1653 options
.forward_x11_timeout
, &proto
, &data
);
1654 /* Request forwarding with authentication spoofing. */
1655 debug("Requesting X11 forwarding with authentication "
1657 x11_request_forwarding_with_spoofing(id
, display
, proto
,
1659 client_expect_confirm(id
, "X11 forwarding", CONFIRM_WARN
);
1660 /* XXX exit_on_forward_failure */
1664 check_agent_present();
1665 if (options
.forward_agent
) {
1666 debug("Requesting authentication agent forwarding.");
1667 channel_request_start(id
, "auth-agent-req@openssh.com", 0);
1671 /* Tell the packet module whether this is an interactive session. */
1672 packet_set_interactive(interactive
,
1673 options
.ip_qos_interactive
, options
.ip_qos_bulk
);
1675 client_session2_setup(id
, tty_flag
, subsystem_flag
, getenv("TERM"),
1676 NULL
, fileno(stdin
), &command
, environ
);
1679 /* open new channel for a session */
1681 ssh_session2_open(void)
1684 int window
, packetmax
, in
, out
, err
;
1686 if (stdin_null_flag
) {
1687 in
= open(_PATH_DEVNULL
, O_RDONLY
);
1689 in
= dup(STDIN_FILENO
);
1691 out
= dup(STDOUT_FILENO
);
1692 err
= dup(STDERR_FILENO
);
1694 if (in
< 0 || out
< 0 || err
< 0)
1695 fatal("dup() in/out/err failed");
1697 /* enable nonblocking unless tty */
1705 window
= CHAN_SES_WINDOW_DEFAULT
;
1706 packetmax
= CHAN_SES_PACKET_DEFAULT
;
1712 "session", SSH_CHANNEL_OPENING
, in
, out
, err
,
1713 window
, packetmax
, CHAN_EXTENDED_WRITE
,
1714 "client-session", /*nonblock*/0);
1716 debug3("ssh_session2_open: channel_new: %d", c
->self
);
1718 channel_send_open(c
->self
);
1720 channel_register_open_confirm(c
->self
,
1721 ssh_session2_setup
, NULL
);
1731 /* XXX should be pre-session */
1732 if (!options
.control_persist
)
1733 ssh_init_stdio_forwarding();
1734 ssh_init_forwarding();
1736 /* Start listening for multiplex clients */
1740 * If we are in control persist mode and have a working mux listen
1741 * socket, then prepare to background ourselves and have a foreground
1742 * client attach as a control slave.
1743 * NB. we must save copies of the flags that we override for
1744 * the backgrounding, since we defer attachment of the slave until
1745 * after the connection is fully established (in particular,
1746 * async rfwd replies have been received for ExitOnForwardFailure).
1748 if (options
.control_persist
&& muxserver_sock
!= -1) {
1749 ostdin_null_flag
= stdin_null_flag
;
1750 ono_shell_flag
= no_shell_flag
;
1751 orequest_tty
= options
.request_tty
;
1752 otty_flag
= tty_flag
;
1753 stdin_null_flag
= 1;
1756 if (!fork_after_authentication_flag
)
1757 need_controlpersist_detach
= 1;
1758 fork_after_authentication_flag
= 1;
1761 * ControlPersist mux listen socket setup failed, attempt the
1762 * stdio forward setup that we skipped earlier.
1764 if (options
.control_persist
&& muxserver_sock
== -1)
1765 ssh_init_stdio_forwarding();
1767 if (!no_shell_flag
|| (datafellows
& SSH_BUG_DUMMYCHAN
))
1768 id
= ssh_session2_open();
1770 packet_set_interactive(
1771 options
.control_master
== SSHCTL_MASTER_NO
,
1772 options
.ip_qos_interactive
, options
.ip_qos_bulk
);
1775 /* If we don't expect to open a new session, then disallow it */
1776 if (options
.control_master
== SSHCTL_MASTER_NO
&&
1777 (datafellows
& SSH_NEW_OPENSSH
)) {
1778 debug("Requesting no-more-sessions@openssh.com");
1779 packet_start(SSH2_MSG_GLOBAL_REQUEST
);
1780 packet_put_cstring("no-more-sessions@openssh.com");
1785 /* Execute a local command */
1786 if (options
.local_command
!= NULL
&&
1787 options
.permit_local_command
)
1788 ssh_local_cmd(options
.local_command
);
1791 * If requested and we are not interested in replies to remote
1792 * forwarding requests, then let ssh continue in the background.
1794 if (fork_after_authentication_flag
) {
1795 if (options
.exit_on_forward_failure
&&
1796 options
.num_remote_forwards
> 0) {
1797 debug("deferring postauth fork until remote forward "
1798 "confirmation received");
1803 if (options
.use_roaming
)
1806 return client_loop(tty_flag
, tty_flag
?
1807 options
.escape_char
: SSH_ESCAPECHAR_NONE
, id
);
1811 load_public_identity_files(void)
1813 char *filename
, *cp
, thishost
[NI_MAXHOST
];
1814 char *pwdir
= NULL
, *pwname
= NULL
;
1819 char *identity_files
[SSH_MAX_IDENTITY_FILES
];
1820 Key
*identity_keys
[SSH_MAX_IDENTITY_FILES
];
1821 #ifdef ENABLE_PKCS11
1827 memset(identity_files
, 0, sizeof(identity_files
));
1828 memset(identity_keys
, 0, sizeof(identity_keys
));
1830 #ifdef ENABLE_PKCS11
1831 if (options
.pkcs11_provider
!= NULL
&&
1832 options
.num_identity_files
< SSH_MAX_IDENTITY_FILES
&&
1833 (pkcs11_init(!options
.batch_mode
) == 0) &&
1834 (nkeys
= pkcs11_add_provider(options
.pkcs11_provider
, NULL
,
1836 for (i
= 0; i
< nkeys
; i
++) {
1837 if (n_ids
>= SSH_MAX_IDENTITY_FILES
) {
1841 identity_keys
[n_ids
] = keys
[i
];
1842 identity_files
[n_ids
] =
1843 xstrdup(options
.pkcs11_provider
); /* XXX */
1848 #endif /* ENABLE_PKCS11 */
1849 if ((pw
= getpwuid(original_real_uid
)) == NULL
)
1850 fatal("load_public_identity_files: getpwuid failed");
1851 pwname
= xstrdup(pw
->pw_name
);
1852 pwdir
= xstrdup(pw
->pw_dir
);
1853 if (gethostname(thishost
, sizeof(thishost
)) == -1)
1854 fatal("load_public_identity_files: gethostname: %s",
1856 for (i
= 0; i
< options
.num_identity_files
; i
++) {
1857 if (n_ids
>= SSH_MAX_IDENTITY_FILES
||
1858 strcasecmp(options
.identity_files
[i
], "none") == 0) {
1859 free(options
.identity_files
[i
]);
1862 cp
= tilde_expand_filename(options
.identity_files
[i
],
1864 filename
= percent_expand(cp
, "d", pwdir
,
1865 "u", pwname
, "l", thishost
, "h", host
,
1866 "r", options
.user
, (char *)NULL
);
1868 public = key_load_public(filename
, NULL
);
1869 debug("identity file %s type %d", filename
,
1870 public ? public->type
: -1);
1871 free(options
.identity_files
[i
]);
1872 identity_files
[n_ids
] = filename
;
1873 identity_keys
[n_ids
] = public;
1875 if (++n_ids
>= SSH_MAX_IDENTITY_FILES
)
1878 /* Try to add the certificate variant too */
1879 xasprintf(&cp
, "%s-cert", filename
);
1880 public = key_load_public(cp
, NULL
);
1881 debug("identity file %s type %d", cp
,
1882 public ? public->type
: -1);
1883 if (public == NULL
) {
1887 if (!key_is_cert(public)) {
1888 debug("%s: key %s type %s is not a certificate",
1889 __func__
, cp
, key_type(public));
1894 identity_keys
[n_ids
] = public;
1895 /* point to the original path, most likely the private key */
1896 identity_files
[n_ids
] = xstrdup(filename
);
1899 options
.num_identity_files
= n_ids
;
1900 memcpy(options
.identity_files
, identity_files
, sizeof(identity_files
));
1901 memcpy(options
.identity_keys
, identity_keys
, sizeof(identity_keys
));
1903 explicit_bzero(pwname
, strlen(pwname
));
1905 explicit_bzero(pwdir
, strlen(pwdir
));
1910 main_sigchld_handler(int sig
)
1912 int save_errno
= errno
;
1916 while ((pid
= waitpid(-1, &status
, WNOHANG
)) > 0 ||
1917 (pid
< 0 && errno
== EINTR
))
1920 signal(sig
, main_sigchld_handler
);