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 %s, %s\n", SSH_RELEASE
,
640 SSH_VERSION_HPN
, SSH_VERSION_DRAGONFLY
,
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
;
788 /* ensure that the user doesn't try to backdoor a */
789 /* null cipher switch on an interactive session */
790 /* so explicitly disable it no matter what */
791 options
.none_switch
=0;
794 line
= xstrdup(optarg
);
795 if (process_config_line(&options
, pw
, host
? host
: "",
796 line
, "command-line", 0, NULL
, SSHCONF_USERCONF
)
805 if (options
.control_path
!= NULL
)
806 free(options
.control_path
);
807 options
.control_path
= xstrdup(optarg
);
810 options
.bind_address
= optarg
;
823 if (ac
> 0 && !host
) {
824 if (strrchr(*av
, '@')) {
826 cp
= strrchr(p
, '@');
827 if (cp
== NULL
|| cp
== p
)
831 host
= xstrdup(++cp
);
835 optind
= optreset
= 1;
841 /* Check that we got a host name. */
845 host_arg
= xstrdup(host
);
848 OpenSSL_add_all_algorithms();
849 ERR_load_crypto_strings();
852 /* Initialize the command to execute on remote host. */
853 buffer_init(&command
);
856 * Save the command to execute on the remote host in a buffer. There
857 * is no limit on the length of the command, except by the maximum
858 * packet size. Also sets the tty flag if there is no command.
861 /* No command specified - execute shell on a tty. */
862 if (subsystem_flag
) {
864 "You must specify a subsystem to invoke.\n");
868 /* A command has been specified. Store it into the buffer. */
869 for (i
= 0; i
< ac
; i
++) {
871 buffer_append(&command
, " ", 1);
872 buffer_append(&command
, av
[i
], strlen(av
[i
]));
876 /* Cannot fork to background if no command. */
877 if (fork_after_authentication_flag
&& buffer_len(&command
) == 0 &&
879 fatal("Cannot fork into background without a command "
883 * Initialize "log" output. Since we are the client all output
884 * goes to stderr unless otherwise specified by -y or -E.
886 if (use_syslog
&& logfile
!= NULL
)
887 fatal("Can't specify both -y and -E");
888 if (logfile
!= NULL
) {
889 log_redirect_stderr_to(logfile
);
893 options
.log_level
== -1 ? SYSLOG_LEVEL_INFO
: options
.log_level
,
894 SYSLOG_FACILITY_USER
, !use_syslog
);
897 logit("%s, %s", SSH_RELEASE
,
899 SSLeay_version(SSLEAY_VERSION
)
905 /* Parse the configuration files */
906 process_config_files(pw
);
908 /* Hostname canonicalisation needs a few options filled. */
909 fill_default_options_for_canonicalization(&options
);
911 /* If the user has replaced the hostname then take it into use now */
912 if (options
.hostname
!= NULL
) {
913 /* NB. Please keep in sync with readconf.c:match_cfg_line() */
914 cp
= percent_expand(options
.hostname
,
915 "h", host
, (char *)NULL
);
920 /* If canonicalization requested then try to apply it */
922 if (options
.canonicalize_hostname
!= SSH_CANONICALISE_NO
)
923 addrs
= resolve_canonicalize(&host
, options
.port
);
926 * If CanonicalizePermittedCNAMEs have been specified but
927 * other canonicalization did not happen (by not being requested
928 * or by failing with fallback) then the hostname may still be changed
929 * as a result of CNAME following.
931 * Try to resolve the bare hostname name using the system resolver's
932 * usual search rules and then apply the CNAME follow rules.
934 * Skip the lookup if a ProxyCommand is being used unless the user
935 * has specifically requested canonicalisation for this case via
936 * CanonicalizeHostname=always
938 if (addrs
== NULL
&& options
.num_permitted_cnames
!= 0 &&
939 (option_clear_or_none(options
.proxy_command
) ||
940 options
.canonicalize_hostname
== SSH_CANONICALISE_ALWAYS
)) {
941 if ((addrs
= resolve_host(host
, options
.port
,
942 option_clear_or_none(options
.proxy_command
),
943 cname
, sizeof(cname
))) == NULL
) {
944 /* Don't fatal proxied host names not in the DNS */
945 if (option_clear_or_none(options
.proxy_command
))
946 cleanup_exit(255); /* logged in resolve_host */
948 check_follow_cname(&host
, cname
);
952 * If the target hostname has changed as a result of canonicalisation
953 * then re-parse the configuration files as new stanzas may match.
955 if (strcasecmp(host_arg
, host
) != 0) {
956 debug("Hostname has changed; re-reading configuration");
957 process_config_files(pw
);
960 /* Fill configuration defaults. */
961 fill_default_options(&options
);
963 if (options
.port
== 0)
964 options
.port
= default_ssh_port();
965 channel_set_af(options
.address_family
);
967 /* Tidy and check options */
968 if (options
.host_key_alias
!= NULL
)
969 lowercase(options
.host_key_alias
);
970 if (options
.proxy_command
!= NULL
&&
971 strcmp(options
.proxy_command
, "-") == 0 &&
972 options
.proxy_use_fdpass
)
973 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible");
975 if (original_effective_uid
!= 0)
976 options
.use_privileged_port
= 0;
980 log_init(argv0
, options
.log_level
, SYSLOG_FACILITY_USER
, !use_syslog
);
982 if (options
.request_tty
== REQUEST_TTY_YES
||
983 options
.request_tty
== REQUEST_TTY_FORCE
)
986 /* Allocate a tty by default if no command specified. */
987 if (buffer_len(&command
) == 0)
988 tty_flag
= options
.request_tty
!= REQUEST_TTY_NO
;
991 if (options
.request_tty
== REQUEST_TTY_NO
|| muxclient_command
!= 0)
993 /* Do not allocate a tty if stdin is not a tty. */
994 if ((!isatty(fileno(stdin
)) || stdin_null_flag
) &&
995 options
.request_tty
!= REQUEST_TTY_FORCE
) {
997 logit("Pseudo-terminal will not be allocated because "
998 "stdin is not a terminal.");
1004 if (options
.user
== NULL
)
1005 options
.user
= xstrdup(pw
->pw_name
);
1007 if (gethostname(thishost
, sizeof(thishost
)) == -1)
1008 fatal("gethostname: %s", strerror(errno
));
1009 strlcpy(shorthost
, thishost
, sizeof(shorthost
));
1010 shorthost
[strcspn(thishost
, ".")] = '\0';
1011 snprintf(portstr
, sizeof(portstr
), "%d", options
.port
);
1013 if ((md
= ssh_digest_start(SSH_DIGEST_SHA1
)) == NULL
||
1014 ssh_digest_update(md
, thishost
, strlen(thishost
)) < 0 ||
1015 ssh_digest_update(md
, host
, strlen(host
)) < 0 ||
1016 ssh_digest_update(md
, portstr
, strlen(portstr
)) < 0 ||
1017 ssh_digest_update(md
, options
.user
, strlen(options
.user
)) < 0 ||
1018 ssh_digest_final(md
, conn_hash
, sizeof(conn_hash
)) < 0)
1019 fatal("%s: mux digest failed", __func__
);
1020 ssh_digest_free(md
);
1021 conn_hash_hex
= tohex(conn_hash
, ssh_digest_bytes(SSH_DIGEST_SHA1
));
1023 if (options
.local_command
!= NULL
) {
1024 debug3("expanding LocalCommand: %s", options
.local_command
);
1025 cp
= options
.local_command
;
1026 options
.local_command
= percent_expand(cp
,
1037 debug3("expanded LocalCommand: %s", options
.local_command
);
1041 if (options
.control_path
!= NULL
) {
1042 cp
= tilde_expand_filename(options
.control_path
,
1044 free(options
.control_path
);
1045 options
.control_path
= percent_expand(cp
,
1057 free(conn_hash_hex
);
1059 if (muxclient_command
!= 0 && options
.control_path
== NULL
)
1060 fatal("No ControlPath specified for \"-O\" command");
1061 if (options
.control_path
!= NULL
)
1062 muxclient(options
.control_path
);
1065 * If hostname canonicalisation was not enabled, then we may not
1066 * have yet resolved the hostname. Do so now.
1068 if (addrs
== NULL
&& options
.proxy_command
== NULL
) {
1069 if ((addrs
= resolve_host(host
, options
.port
, 1,
1070 cname
, sizeof(cname
))) == NULL
)
1071 cleanup_exit(255); /* resolve_host logs the error */
1074 timeout_ms
= options
.connection_timeout
* 1000;
1076 /* Open a connection to the remote host. */
1077 if (ssh_connect(host
, addrs
, &hostaddr
, options
.port
,
1078 options
.address_family
, options
.connection_attempts
,
1079 &timeout_ms
, options
.tcp_keep_alive
,
1080 options
.use_privileged_port
) != 0)
1084 freeaddrinfo(addrs
);
1086 packet_set_timeout(options
.server_alive_interval
,
1087 options
.server_alive_count_max
);
1090 debug3("timeout: %d ms remain after connect", timeout_ms
);
1093 * If we successfully made the connection, load the host private key
1094 * in case we will need it later for combined rsa-rhosts
1095 * authentication. This must be done before releasing extra
1096 * privileges, because the file is only readable by root.
1097 * If we cannot access the private keys, load the public keys
1098 * instead and try to execute the ssh-keysign helper instead.
1100 sensitive_data
.nkeys
= 0;
1101 sensitive_data
.keys
= NULL
;
1102 sensitive_data
.external_keysign
= 0;
1103 if (options
.rhosts_rsa_authentication
||
1104 options
.hostbased_authentication
) {
1105 sensitive_data
.nkeys
= 9;
1106 sensitive_data
.keys
= xcalloc(sensitive_data
.nkeys
,
1108 for (i
= 0; i
< sensitive_data
.nkeys
; i
++)
1109 sensitive_data
.keys
[i
] = NULL
;
1112 sensitive_data
.keys
[0] = key_load_private_type(KEY_RSA1
,
1113 _PATH_HOST_KEY_FILE
, "", NULL
, NULL
);
1114 sensitive_data
.keys
[1] = key_load_private_cert(KEY_DSA
,
1115 _PATH_HOST_DSA_KEY_FILE
, "", NULL
);
1116 #ifdef OPENSSL_HAS_ECC
1117 sensitive_data
.keys
[2] = key_load_private_cert(KEY_ECDSA
,
1118 _PATH_HOST_ECDSA_KEY_FILE
, "", NULL
);
1120 sensitive_data
.keys
[3] = key_load_private_cert(KEY_RSA
,
1121 _PATH_HOST_RSA_KEY_FILE
, "", NULL
);
1122 sensitive_data
.keys
[4] = key_load_private_cert(KEY_ED25519
,
1123 _PATH_HOST_ED25519_KEY_FILE
, "", NULL
);
1124 sensitive_data
.keys
[5] = key_load_private_type(KEY_DSA
,
1125 _PATH_HOST_DSA_KEY_FILE
, "", NULL
, NULL
);
1126 #ifdef OPENSSL_HAS_ECC
1127 sensitive_data
.keys
[6] = key_load_private_type(KEY_ECDSA
,
1128 _PATH_HOST_ECDSA_KEY_FILE
, "", NULL
, NULL
);
1130 sensitive_data
.keys
[7] = key_load_private_type(KEY_RSA
,
1131 _PATH_HOST_RSA_KEY_FILE
, "", NULL
, NULL
);
1132 sensitive_data
.keys
[8] = key_load_private_type(KEY_ED25519
,
1133 _PATH_HOST_ED25519_KEY_FILE
, "", NULL
, NULL
);
1136 if (options
.hostbased_authentication
== 1 &&
1137 sensitive_data
.keys
[0] == NULL
&&
1138 sensitive_data
.keys
[5] == NULL
&&
1139 sensitive_data
.keys
[6] == NULL
&&
1140 sensitive_data
.keys
[7] == NULL
&&
1141 sensitive_data
.keys
[8] == NULL
) {
1142 sensitive_data
.keys
[1] = key_load_cert(
1143 _PATH_HOST_DSA_KEY_FILE
);
1144 #ifdef OPENSSL_HAS_ECC
1145 sensitive_data
.keys
[2] = key_load_cert(
1146 _PATH_HOST_ECDSA_KEY_FILE
);
1148 sensitive_data
.keys
[3] = key_load_cert(
1149 _PATH_HOST_RSA_KEY_FILE
);
1150 sensitive_data
.keys
[4] = key_load_cert(
1151 _PATH_HOST_ED25519_KEY_FILE
);
1152 sensitive_data
.keys
[5] = key_load_public(
1153 _PATH_HOST_DSA_KEY_FILE
, NULL
);
1154 #ifdef OPENSSL_HAS_ECC
1155 sensitive_data
.keys
[6] = key_load_public(
1156 _PATH_HOST_ECDSA_KEY_FILE
, NULL
);
1158 sensitive_data
.keys
[7] = key_load_public(
1159 _PATH_HOST_RSA_KEY_FILE
, NULL
);
1160 sensitive_data
.keys
[8] = key_load_public(
1161 _PATH_HOST_ED25519_KEY_FILE
, NULL
);
1162 sensitive_data
.external_keysign
= 1;
1166 * Get rid of any extra privileges that we may have. We will no
1167 * longer need them. Also, extra privileges could make it very hard
1168 * to read identity files and other non-world-readable files from the
1169 * user's home directory if it happens to be on a NFS volume where
1170 * root is mapped to nobody.
1172 if (original_effective_uid
== 0) {
1174 permanently_set_uid(pw
);
1178 * Now that we are back to our own permissions, create ~/.ssh
1179 * directory if it doesn't already exist.
1181 if (config
== NULL
) {
1182 r
= snprintf(buf
, sizeof buf
, "%s%s%s", pw
->pw_dir
,
1183 strcmp(pw
->pw_dir
, "/") ? "/" : "", _PATH_SSH_USER_DIR
);
1184 if (r
> 0 && (size_t)r
< sizeof(buf
) && stat(buf
, &st
) < 0) {
1186 ssh_selinux_setfscreatecon(buf
);
1188 if (mkdir(buf
, 0700) < 0)
1189 error("Could not create directory '%.200s'.",
1192 ssh_selinux_setfscreatecon(NULL
);
1196 /* load options.identity_files */
1197 load_public_identity_files();
1199 /* Expand ~ in known host file names. */
1200 tilde_expand_paths(options
.system_hostfiles
,
1201 options
.num_system_hostfiles
);
1202 tilde_expand_paths(options
.user_hostfiles
, options
.num_user_hostfiles
);
1204 signal(SIGPIPE
, SIG_IGN
); /* ignore SIGPIPE early */
1205 signal(SIGCHLD
, main_sigchld_handler
);
1207 /* Log into the remote system. Never returns if the login fails. */
1208 ssh_login(&sensitive_data
, host
, (struct sockaddr
*)&hostaddr
,
1209 options
.port
, pw
, timeout_ms
);
1211 if (packet_connection_is_on_socket()) {
1212 verbose("Authenticated to %s ([%s]:%d).", host
,
1213 get_remote_ipaddr(), get_remote_port());
1215 verbose("Authenticated to %s (via proxy).", host
);
1218 /* We no longer need the private host keys. Clear them now. */
1219 if (sensitive_data
.nkeys
!= 0) {
1220 for (i
= 0; i
< sensitive_data
.nkeys
; i
++) {
1221 if (sensitive_data
.keys
[i
] != NULL
) {
1222 /* Destroys contents safely */
1223 debug3("clear hostkey %d", i
);
1224 key_free(sensitive_data
.keys
[i
]);
1225 sensitive_data
.keys
[i
] = NULL
;
1228 free(sensitive_data
.keys
);
1230 for (i
= 0; i
< options
.num_identity_files
; i
++) {
1231 free(options
.identity_files
[i
]);
1232 options
.identity_files
[i
] = NULL
;
1233 if (options
.identity_keys
[i
]) {
1234 key_free(options
.identity_keys
[i
]);
1235 options
.identity_keys
[i
] = NULL
;
1239 exit_status
= compat20
? ssh_session2() : ssh_session();
1242 if (options
.control_path
!= NULL
&& muxserver_sock
!= -1)
1243 unlink(options
.control_path
);
1245 /* Kill ProxyCommand if it is running. */
1246 ssh_kill_proxy_command();
1252 control_persist_detach(void)
1257 debug("%s: backgrounding master process", __func__
);
1260 * master (current process) into the background, and make the
1261 * foreground process a client of the backgrounded master.
1263 switch ((pid
= fork())) {
1265 fatal("%s: fork: %s", __func__
, strerror(errno
));
1267 /* Child: master process continues mainloop */
1270 /* Parent: set up mux slave to connect to backgrounded master */
1271 debug2("%s: background process is %ld", __func__
, (long)pid
);
1272 stdin_null_flag
= ostdin_null_flag
;
1273 options
.request_tty
= orequest_tty
;
1274 tty_flag
= otty_flag
;
1275 close(muxserver_sock
);
1276 muxserver_sock
= -1;
1277 options
.control_master
= SSHCTL_MASTER_NO
;
1278 muxclient(options
.control_path
);
1279 /* muxclient() doesn't return on success. */
1280 fatal("Failed to connect to new control master");
1282 if ((devnull
= open(_PATH_DEVNULL
, O_RDWR
)) == -1) {
1283 error("%s: open(\"/dev/null\"): %s", __func__
,
1286 if (dup2(devnull
, STDIN_FILENO
) == -1 ||
1287 dup2(devnull
, STDOUT_FILENO
) == -1)
1288 error("%s: dup2: %s", __func__
, strerror(errno
));
1289 if (devnull
> STDERR_FILENO
)
1293 setproctitle("%s [mux]", options
.control_path
);
1296 extern const EVP_CIPHER
*evp_aes_ctr_mt(void);
1298 /* Do fork() after authentication. Used by "ssh -f" */
1302 if (need_controlpersist_detach
)
1303 control_persist_detach();
1304 debug("forking to background");
1305 fork_after_authentication_flag
= 0;
1306 if (daemon(1, 1) < 0)
1307 fatal("daemon() failed: %.200s", strerror(errno
));
1310 /* Callback for remote forward global requests */
1312 ssh_confirm_remote_forward(int type
, u_int32_t seq
, void *ctxt
)
1314 struct Forward
*rfwd
= (struct Forward
*)ctxt
;
1316 /* XXX verbose() on failure? */
1317 debug("remote forward %s for: listen %s%s%d, connect %s:%d",
1318 type
== SSH2_MSG_REQUEST_SUCCESS
? "success" : "failure",
1319 rfwd
->listen_path
? rfwd
->listen_path
:
1320 rfwd
->listen_host
? rfwd
->listen_host
: "",
1321 (rfwd
->listen_path
|| rfwd
->listen_host
) ? ":" : "",
1322 rfwd
->listen_port
, rfwd
->connect_path
? rfwd
->connect_path
:
1323 rfwd
->connect_host
, rfwd
->connect_port
);
1324 if (rfwd
->listen_path
== NULL
&& rfwd
->listen_port
== 0) {
1325 if (type
== SSH2_MSG_REQUEST_SUCCESS
) {
1326 rfwd
->allocated_port
= packet_get_int();
1327 logit("Allocated port %u for remote forward to %s:%d",
1328 rfwd
->allocated_port
,
1329 rfwd
->connect_host
, rfwd
->connect_port
);
1330 channel_update_permitted_opens(rfwd
->handle
,
1331 rfwd
->allocated_port
);
1333 channel_update_permitted_opens(rfwd
->handle
, -1);
1337 if (type
== SSH2_MSG_REQUEST_FAILURE
) {
1338 if (options
.exit_on_forward_failure
) {
1339 if (rfwd
->listen_path
!= NULL
)
1340 fatal("Error: remote port forwarding failed "
1341 "for listen path %s", rfwd
->listen_path
);
1343 fatal("Error: remote port forwarding failed "
1344 "for listen port %d", rfwd
->listen_port
);
1346 if (rfwd
->listen_path
!= NULL
)
1347 logit("Warning: remote port forwarding failed "
1348 "for listen path %s", rfwd
->listen_path
);
1350 logit("Warning: remote port forwarding failed "
1351 "for listen port %d", rfwd
->listen_port
);
1354 if (++remote_forward_confirms_received
== options
.num_remote_forwards
) {
1355 debug("All remote forwarding requests processed");
1356 if (fork_after_authentication_flag
)
1362 client_cleanup_stdio_fwd(int id
, void *arg
)
1364 debug("stdio forwarding: done");
1369 ssh_stdio_confirm(int id
, int success
, void *arg
)
1372 fatal("stdio forwarding failed");
1376 ssh_init_stdio_forwarding(void)
1381 if (stdio_forward_host
== NULL
)
1384 fatal("stdio forwarding require Protocol 2");
1386 debug3("%s: %s:%d", __func__
, stdio_forward_host
, stdio_forward_port
);
1388 if ((in
= dup(STDIN_FILENO
)) < 0 ||
1389 (out
= dup(STDOUT_FILENO
)) < 0)
1390 fatal("channel_connect_stdio_fwd: dup() in/out failed");
1391 if ((c
= channel_connect_stdio_fwd(stdio_forward_host
,
1392 stdio_forward_port
, in
, out
)) == NULL
)
1393 fatal("%s: channel_connect_stdio_fwd failed", __func__
);
1394 channel_register_cleanup(c
->self
, client_cleanup_stdio_fwd
, 0);
1395 channel_register_open_confirm(c
->self
, ssh_stdio_confirm
, NULL
);
1399 ssh_init_forwarding(void)
1404 /* Initiate local TCP/IP port forwardings. */
1405 for (i
= 0; i
< options
.num_local_forwards
; i
++) {
1406 debug("Local connections to %.200s:%d forwarded to remote "
1407 "address %.200s:%d",
1408 (options
.local_forwards
[i
].listen_path
!= NULL
) ?
1409 options
.local_forwards
[i
].listen_path
:
1410 (options
.local_forwards
[i
].listen_host
== NULL
) ?
1411 (options
.fwd_opts
.gateway_ports
? "*" : "LOCALHOST") :
1412 options
.local_forwards
[i
].listen_host
,
1413 options
.local_forwards
[i
].listen_port
,
1414 (options
.local_forwards
[i
].connect_path
!= NULL
) ?
1415 options
.local_forwards
[i
].connect_path
:
1416 options
.local_forwards
[i
].connect_host
,
1417 options
.local_forwards
[i
].connect_port
);
1418 success
+= channel_setup_local_fwd_listener(
1419 &options
.local_forwards
[i
], &options
.fwd_opts
);
1421 if (i
> 0 && success
!= i
&& options
.exit_on_forward_failure
)
1422 fatal("Could not request local forwarding.");
1423 if (i
> 0 && success
== 0)
1424 error("Could not request local forwarding.");
1426 /* Initiate remote TCP/IP port forwardings. */
1427 for (i
= 0; i
< options
.num_remote_forwards
; i
++) {
1428 debug("Remote connections from %.200s:%d forwarded to "
1429 "local address %.200s:%d",
1430 (options
.remote_forwards
[i
].listen_path
!= NULL
) ?
1431 options
.remote_forwards
[i
].listen_path
:
1432 (options
.remote_forwards
[i
].listen_host
== NULL
) ?
1433 "LOCALHOST" : options
.remote_forwards
[i
].listen_host
,
1434 options
.remote_forwards
[i
].listen_port
,
1435 (options
.remote_forwards
[i
].connect_path
!= NULL
) ?
1436 options
.remote_forwards
[i
].connect_path
:
1437 options
.remote_forwards
[i
].connect_host
,
1438 options
.remote_forwards
[i
].connect_port
);
1439 options
.remote_forwards
[i
].handle
=
1440 channel_request_remote_forwarding(
1441 &options
.remote_forwards
[i
]);
1442 if (options
.remote_forwards
[i
].handle
< 0) {
1443 if (options
.exit_on_forward_failure
)
1444 fatal("Could not request remote forwarding.");
1446 logit("Warning: Could not request remote "
1449 client_register_global_confirm(ssh_confirm_remote_forward
,
1450 &options
.remote_forwards
[i
]);
1454 /* Initiate tunnel forwarding. */
1455 if (options
.tun_open
!= SSH_TUNMODE_NO
) {
1456 if (client_request_tun_fwd(options
.tun_open
,
1457 options
.tun_local
, options
.tun_remote
) == -1) {
1458 if (options
.exit_on_forward_failure
)
1459 fatal("Could not request tunnel forwarding.");
1461 error("Could not request tunnel forwarding.");
1467 check_agent_present(void)
1469 if (options
.forward_agent
) {
1470 /* Clear agent forwarding if we don't have an agent. */
1471 if (!ssh_agent_present())
1472 options
.forward_agent
= 0;
1480 int interactive
= 0;
1484 const char *display
;
1486 /* Enable compression if requested. */
1487 if (options
.compression
) {
1488 debug("Requesting compression at level %d.",
1489 options
.compression_level
);
1491 if (options
.compression_level
< 1 ||
1492 options
.compression_level
> 9)
1493 fatal("Compression level must be from 1 (fast) to "
1496 /* Send the request. */
1497 packet_start(SSH_CMSG_REQUEST_COMPRESSION
);
1498 packet_put_int(options
.compression_level
);
1500 packet_write_wait();
1501 type
= packet_read();
1502 if (type
== SSH_SMSG_SUCCESS
)
1503 packet_start_compression(options
.compression_level
);
1504 else if (type
== SSH_SMSG_FAILURE
)
1505 logit("Warning: Remote host refused compression.");
1507 packet_disconnect("Protocol error waiting for "
1508 "compression response.");
1510 /* Allocate a pseudo tty if appropriate. */
1512 debug("Requesting pty.");
1514 /* Start the packet. */
1515 packet_start(SSH_CMSG_REQUEST_PTY
);
1517 /* Store TERM in the packet. There is no limit on the
1518 length of the string. */
1519 cp
= getenv("TERM");
1522 packet_put_cstring(cp
);
1524 /* Store window size in the packet. */
1525 if (ioctl(fileno(stdin
), TIOCGWINSZ
, &ws
) < 0)
1526 memset(&ws
, 0, sizeof(ws
));
1527 packet_put_int((u_int
)ws
.ws_row
);
1528 packet_put_int((u_int
)ws
.ws_col
);
1529 packet_put_int((u_int
)ws
.ws_xpixel
);
1530 packet_put_int((u_int
)ws
.ws_ypixel
);
1532 /* Store tty modes in the packet. */
1533 tty_make_modes(fileno(stdin
), NULL
);
1535 /* Send the packet, and wait for it to leave. */
1537 packet_write_wait();
1539 /* Read response from the server. */
1540 type
= packet_read();
1541 if (type
== SSH_SMSG_SUCCESS
) {
1544 } else if (type
== SSH_SMSG_FAILURE
)
1545 logit("Warning: Remote host failed or refused to "
1546 "allocate a pseudo tty.");
1548 packet_disconnect("Protocol error waiting for pty "
1549 "request response.");
1551 /* Request X11 forwarding if enabled and DISPLAY is set. */
1552 display
= getenv("DISPLAY");
1553 if (options
.forward_x11
&& display
!= NULL
) {
1555 /* Get reasonable local authentication information. */
1556 client_x11_get_proto(display
, options
.xauth_location
,
1557 options
.forward_x11_trusted
,
1558 options
.forward_x11_timeout
,
1560 /* Request forwarding with authentication spoofing. */
1561 debug("Requesting X11 forwarding with authentication "
1563 x11_request_forwarding_with_spoofing(0, display
, proto
,
1565 /* Read response from the server. */
1566 type
= packet_read();
1567 if (type
== SSH_SMSG_SUCCESS
) {
1569 } else if (type
== SSH_SMSG_FAILURE
) {
1570 logit("Warning: Remote host denied X11 forwarding.");
1572 packet_disconnect("Protocol error waiting for X11 "
1576 /* Tell the packet module whether this is an interactive session. */
1577 packet_set_interactive(interactive
,
1578 options
.ip_qos_interactive
, options
.ip_qos_bulk
);
1580 /* Request authentication agent forwarding if appropriate. */
1581 check_agent_present();
1583 if (options
.forward_agent
) {
1584 debug("Requesting authentication agent forwarding.");
1585 auth_request_forwarding();
1587 /* Read response from the server. */
1588 type
= packet_read();
1590 if (type
!= SSH_SMSG_SUCCESS
)
1591 logit("Warning: Remote host denied authentication agent forwarding.");
1594 /* Initiate port forwardings. */
1595 ssh_init_stdio_forwarding();
1596 ssh_init_forwarding();
1598 /* Execute a local command */
1599 if (options
.local_command
!= NULL
&&
1600 options
.permit_local_command
)
1601 ssh_local_cmd(options
.local_command
);
1604 * If requested and we are not interested in replies to remote
1605 * forwarding requests, then let ssh continue in the background.
1607 if (fork_after_authentication_flag
) {
1608 if (options
.exit_on_forward_failure
&&
1609 options
.num_remote_forwards
> 0) {
1610 debug("deferring postauth fork until remote forward "
1611 "confirmation received");
1617 * If a command was specified on the command line, execute the
1618 * command now. Otherwise request the server to start a shell.
1620 if (buffer_len(&command
) > 0) {
1621 int len
= buffer_len(&command
);
1624 debug("Sending command: %.*s", len
,
1625 (u_char
*)buffer_ptr(&command
));
1626 packet_start(SSH_CMSG_EXEC_CMD
);
1627 packet_put_string(buffer_ptr(&command
), buffer_len(&command
));
1629 packet_write_wait();
1631 debug("Requesting shell.");
1632 packet_start(SSH_CMSG_EXEC_SHELL
);
1634 packet_write_wait();
1637 /* Enter the interactive session. */
1638 return client_loop(have_tty
, tty_flag
?
1639 options
.escape_char
: SSH_ESCAPECHAR_NONE
, 0);
1642 /* request pty/x11/agent/tcpfwd/shell for channel */
1644 ssh_session2_setup(int id
, int success
, void *arg
)
1646 extern char **environ
;
1647 const char *display
;
1648 int interactive
= tty_flag
;
1651 return; /* No need for error message, channels code sens one */
1653 display
= getenv("DISPLAY");
1654 if (options
.forward_x11
&& display
!= NULL
) {
1656 /* Get reasonable local authentication information. */
1657 client_x11_get_proto(display
, options
.xauth_location
,
1658 options
.forward_x11_trusted
,
1659 options
.forward_x11_timeout
, &proto
, &data
);
1660 /* Request forwarding with authentication spoofing. */
1661 debug("Requesting X11 forwarding with authentication "
1663 x11_request_forwarding_with_spoofing(id
, display
, proto
,
1665 client_expect_confirm(id
, "X11 forwarding", CONFIRM_WARN
);
1666 /* XXX exit_on_forward_failure */
1670 check_agent_present();
1671 if (options
.forward_agent
) {
1672 debug("Requesting authentication agent forwarding.");
1673 channel_request_start(id
, "auth-agent-req@openssh.com", 0);
1677 /* Tell the packet module whether this is an interactive session. */
1678 packet_set_interactive(interactive
,
1679 options
.ip_qos_interactive
, options
.ip_qos_bulk
);
1681 client_session2_setup(id
, tty_flag
, subsystem_flag
, getenv("TERM"),
1682 NULL
, fileno(stdin
), &command
, environ
);
1685 /* open new channel for a session */
1687 ssh_session2_open(void)
1690 int window
, packetmax
, in
, out
, err
;
1693 int socksizelen
= sizeof(int);
1695 if (stdin_null_flag
) {
1696 in
= open(_PATH_DEVNULL
, O_RDONLY
);
1698 in
= dup(STDIN_FILENO
);
1700 out
= dup(STDOUT_FILENO
);
1701 err
= dup(STDERR_FILENO
);
1703 if (in
< 0 || out
< 0 || err
< 0)
1704 fatal("dup() in/out/err failed");
1706 /* enable nonblocking unless tty */
1714 /* we need to check to see if what they want to do about buffer */
1715 /* sizes here. In a hpn to nonhpn connection we want to limit */
1716 /* the window size to something reasonable in case the far side */
1717 /* has the large window bug. In hpn to hpn connection we want to */
1718 /* use the max window size but allow the user to override it */
1719 /* lastly if they disabled hpn then use the ssh std window size */
1721 /* so why don't we just do a getsockopt() here and set the */
1722 /* ssh window to that? In the case of a autotuning receive */
1723 /* window the window would get stuck at the initial buffer */
1724 /* size generally less than 96k. Therefore we need to set the */
1725 /* maximum ssh window size to the maximum hpn buffer size */
1726 /* unless the user has specifically set the tcprcvbufpoll */
1727 /* to no. In which case we *can* just set the window to the */
1728 /* minimum of the hpn buffer size and tcp receive buffer size */
1731 options
.hpn_buffer_size
= CHAN_SES_WINDOW_DEFAULT
;
1733 options
.hpn_buffer_size
= 2*1024*1024;
1735 if (datafellows
& SSH_BUG_LARGEWINDOW
)
1737 debug("HPN to Non-HPN Connection");
1741 if (options
.tcp_rcv_buf_poll
<= 0)
1743 sock
= socket(AF_INET
, SOCK_STREAM
, 0);
1744 getsockopt(sock
, SOL_SOCKET
, SO_RCVBUF
,
1745 &socksize
, &socksizelen
);
1747 debug("socksize %d", socksize
);
1748 options
.hpn_buffer_size
= socksize
;
1749 debug ("HPNBufferSize set to TCP RWIN: %d", options
.hpn_buffer_size
);
1753 if (options
.tcp_rcv_buf
> 0)
1755 /*create a socket but don't connect it */
1756 /* we use that the get the rcv socket size */
1757 sock
= socket(AF_INET
, SOCK_STREAM
, 0);
1758 /* if they are using the tcp_rcv_buf option */
1759 /* attempt to set the buffer size to that */
1760 if (options
.tcp_rcv_buf
)
1761 setsockopt(sock
, SOL_SOCKET
, SO_RCVBUF
, (void *)&options
.tcp_rcv_buf
,
1762 sizeof(options
.tcp_rcv_buf
));
1763 getsockopt(sock
, SOL_SOCKET
, SO_RCVBUF
,
1764 &socksize
, &socksizelen
);
1766 debug("socksize %d", socksize
);
1767 options
.hpn_buffer_size
= socksize
;
1768 debug ("HPNBufferSize set to user TCPRcvBuf: %d", options
.hpn_buffer_size
);
1773 debug("Final hpn_buffer_size = %d", options
.hpn_buffer_size
);
1775 window
= options
.hpn_buffer_size
;
1777 channel_set_hpn(options
.hpn_disabled
, options
.hpn_buffer_size
);
1779 packetmax
= CHAN_SES_PACKET_DEFAULT
;
1781 window
= 4*CHAN_SES_PACKET_DEFAULT
;
1786 "session", SSH_CHANNEL_OPENING
, in
, out
, err
,
1787 window
, packetmax
, CHAN_EXTENDED_WRITE
,
1788 "client-session", /*nonblock*/0);
1790 if ((options
.tcp_rcv_buf_poll
> 0) && (!options
.hpn_disabled
)) {
1791 c
->dynamic_window
= 1;
1792 debug ("Enabled Dynamic Window Scaling");
1794 debug3("ssh_session2_open: channel_new: %d", c
->self
);
1796 channel_send_open(c
->self
);
1798 channel_register_open_confirm(c
->self
,
1799 ssh_session2_setup
, NULL
);
1809 /* XXX should be pre-session */
1810 if (!options
.control_persist
)
1811 ssh_init_stdio_forwarding();
1812 ssh_init_forwarding();
1814 /* Start listening for multiplex clients */
1818 * If we are in control persist mode and have a working mux listen
1819 * socket, then prepare to background ourselves and have a foreground
1820 * client attach as a control slave.
1821 * NB. we must save copies of the flags that we override for
1822 * the backgrounding, since we defer attachment of the slave until
1823 * after the connection is fully established (in particular,
1824 * async rfwd replies have been received for ExitOnForwardFailure).
1826 if (options
.control_persist
&& muxserver_sock
!= -1) {
1827 ostdin_null_flag
= stdin_null_flag
;
1828 ono_shell_flag
= no_shell_flag
;
1829 orequest_tty
= options
.request_tty
;
1830 otty_flag
= tty_flag
;
1831 stdin_null_flag
= 1;
1834 if (!fork_after_authentication_flag
)
1835 need_controlpersist_detach
= 1;
1836 fork_after_authentication_flag
= 1;
1839 * ControlPersist mux listen socket setup failed, attempt the
1840 * stdio forward setup that we skipped earlier.
1842 if (options
.control_persist
&& muxserver_sock
== -1)
1843 ssh_init_stdio_forwarding();
1845 if (!no_shell_flag
|| (datafellows
& SSH_BUG_DUMMYCHAN
))
1846 id
= ssh_session2_open();
1848 packet_set_interactive(
1849 options
.control_master
== SSHCTL_MASTER_NO
,
1850 options
.ip_qos_interactive
, options
.ip_qos_bulk
);
1853 /* If we don't expect to open a new session, then disallow it */
1854 if (options
.control_master
== SSHCTL_MASTER_NO
&&
1855 (datafellows
& SSH_NEW_OPENSSH
)) {
1856 debug("Requesting no-more-sessions@openssh.com");
1857 packet_start(SSH2_MSG_GLOBAL_REQUEST
);
1858 packet_put_cstring("no-more-sessions@openssh.com");
1863 /* Execute a local command */
1864 if (options
.local_command
!= NULL
&&
1865 options
.permit_local_command
)
1866 ssh_local_cmd(options
.local_command
);
1869 * If requested and we are not interested in replies to remote
1870 * forwarding requests, then let ssh continue in the background.
1872 if (fork_after_authentication_flag
) {
1873 if (options
.exit_on_forward_failure
&&
1874 options
.num_remote_forwards
> 0) {
1875 debug("deferring postauth fork until remote forward "
1876 "confirmation received");
1881 return client_loop(tty_flag
, tty_flag
?
1882 options
.escape_char
: SSH_ESCAPECHAR_NONE
, id
);
1886 load_public_identity_files(void)
1888 char *filename
, *cp
, thishost
[NI_MAXHOST
];
1889 char *pwdir
= NULL
, *pwname
= NULL
;
1894 char *identity_files
[SSH_MAX_IDENTITY_FILES
];
1895 Key
*identity_keys
[SSH_MAX_IDENTITY_FILES
];
1896 #ifdef ENABLE_PKCS11
1902 memset(identity_files
, 0, sizeof(identity_files
));
1903 memset(identity_keys
, 0, sizeof(identity_keys
));
1905 #ifdef ENABLE_PKCS11
1906 if (options
.pkcs11_provider
!= NULL
&&
1907 options
.num_identity_files
< SSH_MAX_IDENTITY_FILES
&&
1908 (pkcs11_init(!options
.batch_mode
) == 0) &&
1909 (nkeys
= pkcs11_add_provider(options
.pkcs11_provider
, NULL
,
1911 for (i
= 0; i
< nkeys
; i
++) {
1912 if (n_ids
>= SSH_MAX_IDENTITY_FILES
) {
1916 identity_keys
[n_ids
] = keys
[i
];
1917 identity_files
[n_ids
] =
1918 xstrdup(options
.pkcs11_provider
); /* XXX */
1923 #endif /* ENABLE_PKCS11 */
1924 if ((pw
= getpwuid(original_real_uid
)) == NULL
)
1925 fatal("load_public_identity_files: getpwuid failed");
1926 pwname
= xstrdup(pw
->pw_name
);
1927 pwdir
= xstrdup(pw
->pw_dir
);
1928 if (gethostname(thishost
, sizeof(thishost
)) == -1)
1929 fatal("load_public_identity_files: gethostname: %s",
1931 for (i
= 0; i
< options
.num_identity_files
; i
++) {
1932 if (n_ids
>= SSH_MAX_IDENTITY_FILES
||
1933 strcasecmp(options
.identity_files
[i
], "none") == 0) {
1934 free(options
.identity_files
[i
]);
1937 cp
= tilde_expand_filename(options
.identity_files
[i
],
1939 filename
= percent_expand(cp
, "d", pwdir
,
1940 "u", pwname
, "l", thishost
, "h", host
,
1941 "r", options
.user
, (char *)NULL
);
1943 public = key_load_public(filename
, NULL
);
1944 debug("identity file %s type %d", filename
,
1945 public ? public->type
: -1);
1946 free(options
.identity_files
[i
]);
1947 identity_files
[n_ids
] = filename
;
1948 identity_keys
[n_ids
] = public;
1950 if (++n_ids
>= SSH_MAX_IDENTITY_FILES
)
1953 /* Try to add the certificate variant too */
1954 xasprintf(&cp
, "%s-cert", filename
);
1955 public = key_load_public(cp
, NULL
);
1956 debug("identity file %s type %d", cp
,
1957 public ? public->type
: -1);
1958 if (public == NULL
) {
1962 if (!key_is_cert(public)) {
1963 debug("%s: key %s type %s is not a certificate",
1964 __func__
, cp
, key_type(public));
1969 identity_keys
[n_ids
] = public;
1970 /* point to the original path, most likely the private key */
1971 identity_files
[n_ids
] = xstrdup(filename
);
1974 options
.num_identity_files
= n_ids
;
1975 memcpy(options
.identity_files
, identity_files
, sizeof(identity_files
));
1976 memcpy(options
.identity_keys
, identity_keys
, sizeof(identity_keys
));
1978 explicit_bzero(pwname
, strlen(pwname
));
1980 explicit_bzero(pwdir
, strlen(pwdir
));
1985 main_sigchld_handler(int sig
)
1987 int save_errno
= errno
;
1991 while ((pid
= waitpid(-1, &status
, WNOHANG
)) > 0 ||
1992 (pid
< 0 && errno
== EINTR
))
1995 signal(sig
, main_sigchld_handler
);