1 /* $OpenBSD: ssh.c,v 1.326 2009/07/02 02:11:47 dtucker 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>
70 #include <netinet/in.h>
71 #include <arpa/inet.h>
73 #include <openssl/evp.h>
74 #include <openssl/err.h>
75 #include "openbsd-compat/openssl-compat.h"
76 #include "openbsd-compat/sys-queue.h"
90 #include "pathnames.h"
92 #include "clientloop.h"
95 #include "sshconnect.h"
109 extern char *__progname
;
111 /* Flag indicating whether debug mode is on. May be set on the command line. */
114 /* Flag indicating whether a tty should be allocated */
117 int force_tty_flag
= 0;
119 /* don't exec a shell */
120 int no_shell_flag
= 0;
123 * Flag indicating that nothing should be read from stdin. This can be set
124 * on the command line.
126 int stdin_null_flag
= 0;
129 * Flag indicating that ssh should fork after authentication. This is useful
130 * so that the passphrase can be entered manually, and then ssh goes to the
133 int fork_after_authentication_flag
= 0;
136 * General data structure for command line options and options configurable
137 * in configuration files. See readconf.h.
141 /* optional user configfile */
145 * Name of the host we are connecting to. This is the name given on the
146 * command line, or the HostName specified for the user-supplied name in a
147 * configuration file.
151 /* socket address the host resolves to */
152 struct sockaddr_storage hostaddr
;
154 /* Private host keys. */
155 Sensitive sensitive_data
;
157 /* Original real UID. */
158 uid_t original_real_uid
;
159 uid_t original_effective_uid
;
161 /* command to be executed */
164 /* Should we execute a command or invoke a subsystem? */
165 int subsystem_flag
= 0;
167 /* # of replies received for global requests */
168 static int remote_forward_confirms_received
= 0;
170 /* pid of proxycommand child process */
171 pid_t proxy_command_pid
= 0;
174 extern int muxserver_sock
;
175 extern u_int muxclient_command
;
177 /* Prints a help message to the user. This function never returns. */
183 "usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n"
184 " [-D [bind_address:]port] [-e escape_char] [-F configfile]\n"
185 " [-i identity_file] [-L [bind_address:]port:host:hostport]\n"
186 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
187 " [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
188 " [-w local_tun[:remote_tun]] [user@]hostname [command]\n"
193 static int ssh_session(void);
194 static int ssh_session2(void);
195 static void load_public_identity_files(void);
197 /* from muxclient.c */
198 void muxclient(const char *);
199 void muxserver_listen(void);
202 * Main program for the ssh client.
205 main(int ac
, char **av
)
207 int i
, r
, opt
, exit_status
, use_syslog
;
208 char *p
, *cp
, *line
, *argv0
, buf
[MAXPATHLEN
];
211 int dummy
, timeout_ms
;
212 extern int optind
, optreset
;
217 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
220 __progname
= ssh_get_progname(av
[0]);
224 * Save the original real uid. It will be needed later (uid-swapping
225 * may clobber the real uid).
227 original_real_uid
= getuid();
228 original_effective_uid
= geteuid();
231 * Use uid-swapping to give up root privileges for the duration of
232 * option processing. We will re-instantiate the rights when we are
233 * ready to create the privileged port, and will permanently drop
234 * them when the port has been created (actually, when the connection
235 * has been made, as we may need to create the port several times).
239 #ifdef HAVE_SETRLIMIT
240 /* If we are installed setuid root be careful to not drop core. */
241 if (original_real_uid
!= original_effective_uid
) {
243 rlim
.rlim_cur
= rlim
.rlim_max
= 0;
244 if (setrlimit(RLIMIT_CORE
, &rlim
) < 0)
245 fatal("setrlimit failed: %.100s", strerror(errno
));
249 pw
= getpwuid(original_real_uid
);
251 logit("You don't exist, go away!");
254 /* Take a copy of the returned structure. */
258 * Set our umask to something reasonable, as some files are created
259 * with the default umask. This will make them world-readable but
260 * writable only by the owner, which is ok for all files for which we
261 * don't set the modes explicitly.
266 * Initialize option structure to indicate that no values have been
269 initialize_options(&options
);
271 /* Parse command-line arguments. */
277 while ((opt
= getopt(ac
, av
, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
278 "ACD:F:I:KL:MNO:PR:S:TVw:XYy")) != -1) {
281 options
.protocol
= SSH_PROTO_1
;
284 options
.protocol
= SSH_PROTO_2
;
287 options
.address_family
= AF_INET
;
290 options
.address_family
= AF_INET6
;
296 fork_after_authentication_flag
= 1;
300 options
.forward_x11
= 0;
303 options
.forward_x11
= 1;
309 options
.forward_x11
= 1;
310 options
.forward_x11_trusted
= 1;
313 options
.gateway_ports
= 1;
316 if (strcmp(optarg
, "check") == 0)
317 muxclient_command
= SSHMUX_COMMAND_ALIVE_CHECK
;
318 else if (strcmp(optarg
, "exit") == 0)
319 muxclient_command
= SSHMUX_COMMAND_TERMINATE
;
321 fatal("Invalid multiplex command.");
323 case 'P': /* deprecated */
324 options
.use_privileged_port
= 0;
327 options
.forward_agent
= 0;
330 options
.forward_agent
= 1;
333 options
.gss_deleg_creds
= 0;
336 options
.gss_authentication
= 1;
337 options
.gss_deleg_creds
= 1;
340 if (stat(optarg
, &st
) < 0) {
341 fprintf(stderr
, "Warning: Identity file %s "
342 "not accessible: %s.\n", optarg
,
346 if (options
.num_identity_files
>=
347 SSH_MAX_IDENTITY_FILES
)
348 fatal("Too many identity files specified "
349 "(max %d)", SSH_MAX_IDENTITY_FILES
);
350 options
.identity_files
[options
.num_identity_files
++] =
355 options
.smartcard_device
= xstrdup(optarg
);
357 fprintf(stderr
, "no support for smartcards.\n");
366 if (debug_flag
== 0) {
368 options
.log_level
= SYSLOG_LEVEL_DEBUG1
;
370 if (options
.log_level
< SYSLOG_LEVEL_DEBUG3
)
376 fprintf(stderr
, "%s, %s\n",
377 SSH_RELEASE
, SSLeay_version(SSLEAY_VERSION
));
382 if (options
.tun_open
== -1)
383 options
.tun_open
= SSH_TUNMODE_DEFAULT
;
384 options
.tun_local
= a2tun(optarg
, &options
.tun_remote
);
385 if (options
.tun_local
== SSH_TUNID_ERR
) {
387 "Bad tun device '%s'\n", optarg
);
392 options
.log_level
= SYSLOG_LEVEL_QUIET
;
395 if (optarg
[0] == '^' && optarg
[2] == 0 &&
396 (u_char
) optarg
[1] >= 64 &&
397 (u_char
) optarg
[1] < 128)
398 options
.escape_char
= (u_char
) optarg
[1] & 31;
399 else if (strlen(optarg
) == 1)
400 options
.escape_char
= (u_char
) optarg
[0];
401 else if (strcmp(optarg
, "none") == 0)
402 options
.escape_char
= SSH_ESCAPECHAR_NONE
;
404 fprintf(stderr
, "Bad escape character '%s'.\n",
410 if (ciphers_valid(optarg
)) {
412 options
.ciphers
= xstrdup(optarg
);
413 options
.cipher
= SSH_CIPHER_INVALID
;
416 options
.cipher
= cipher_number(optarg
);
417 if (options
.cipher
== -1) {
419 "Unknown cipher type '%s'\n",
423 if (options
.cipher
== SSH_CIPHER_3DES
)
424 options
.ciphers
= "3des-cbc";
425 else if (options
.cipher
== SSH_CIPHER_BLOWFISH
)
426 options
.ciphers
= "blowfish-cbc";
428 options
.ciphers
= (char *)-1;
432 if (mac_valid(optarg
))
433 options
.macs
= xstrdup(optarg
);
435 fprintf(stderr
, "Unknown mac type '%s'\n",
441 if (options
.control_master
== SSHCTL_MASTER_YES
)
442 options
.control_master
= SSHCTL_MASTER_ASK
;
444 options
.control_master
= SSHCTL_MASTER_YES
;
447 options
.port
= a2port(optarg
);
448 if (options
.port
<= 0) {
449 fprintf(stderr
, "Bad port '%s'\n", optarg
);
454 options
.user
= optarg
;
458 if (parse_forward(&fwd
, optarg
, 0, 0))
459 add_local_forward(&options
, &fwd
);
462 "Bad local forwarding specification '%s'\n",
469 if (parse_forward(&fwd
, optarg
, 0, 1)) {
470 add_remote_forward(&options
, &fwd
);
473 "Bad remote forwarding specification "
480 if (parse_forward(&fwd
, optarg
, 1, 0)) {
481 add_local_forward(&options
, &fwd
);
484 "Bad dynamic forwarding specification "
491 options
.compression
= 1;
499 line
= xstrdup(optarg
);
500 if (process_config_line(&options
, host
? host
: "",
501 line
, "command-line", 0, &dummy
) != 0)
507 /* ensure that the user doesn't try to backdoor a */
508 /* null cipher switch on an interactive session */
509 /* so explicitly disable it no matter what */
510 options
.none_switch
=0;
516 if (options
.control_path
!= NULL
)
517 free(options
.control_path
);
518 options
.control_path
= xstrdup(optarg
);
521 options
.bind_address
= optarg
;
534 if (ac
> 0 && !host
&& **av
!= '-') {
535 if (strrchr(*av
, '@')) {
537 cp
= strrchr(p
, '@');
538 if (cp
== NULL
|| cp
== p
)
546 optind
= optreset
= 1;
552 /* Check that we got a host name. */
556 SSLeay_add_all_algorithms();
557 ERR_load_crypto_strings();
559 /* Initialize the command to execute on remote host. */
560 buffer_init(&command
);
563 * Save the command to execute on the remote host in a buffer. There
564 * is no limit on the length of the command, except by the maximum
565 * packet size. Also sets the tty flag if there is no command.
568 /* No command specified - execute shell on a tty. */
570 if (subsystem_flag
) {
572 "You must specify a subsystem to invoke.\n");
576 /* A command has been specified. Store it into the buffer. */
577 for (i
= 0; i
< ac
; i
++) {
579 buffer_append(&command
, " ", 1);
580 buffer_append(&command
, av
[i
], strlen(av
[i
]));
584 /* Cannot fork to background if no command. */
585 if (fork_after_authentication_flag
&& buffer_len(&command
) == 0 &&
587 fatal("Cannot fork into background without a command "
590 /* Allocate a tty by default if no command specified. */
591 if (buffer_len(&command
) == 0)
597 /* Do not allocate a tty if stdin is not a tty. */
598 if ((!isatty(fileno(stdin
)) || stdin_null_flag
) && !force_tty_flag
) {
600 logit("Pseudo-terminal will not be allocated because "
601 "stdin is not a terminal.");
606 * Initialize "log" output. Since we are the client all output
607 * actually goes to stderr.
610 options
.log_level
== -1 ? SYSLOG_LEVEL_INFO
: options
.log_level
,
611 SYSLOG_FACILITY_USER
, !use_syslog
);
614 * Read per-user configuration file. Ignore the system wide config
615 * file if the user specifies a config file on the command line.
617 if (config
!= NULL
) {
618 if (!read_config_file(config
, host
, &options
, 0))
619 fatal("Can't open user config file %.100s: "
620 "%.100s", config
, strerror(errno
));
622 r
= snprintf(buf
, sizeof buf
, "%s/%s", pw
->pw_dir
,
623 _PATH_SSH_USER_CONFFILE
);
624 if (r
> 0 && (size_t)r
< sizeof(buf
))
625 (void)read_config_file(buf
, host
, &options
, 1);
627 /* Read systemwide configuration file after use config. */
628 (void)read_config_file(_PATH_HOST_CONFIG_FILE
, host
,
632 /* Fill configuration defaults. */
633 fill_default_options(&options
);
635 channel_set_af(options
.address_family
);
638 log_init(argv0
, options
.log_level
, SYSLOG_FACILITY_USER
, !use_syslog
);
642 if (options
.user
== NULL
)
643 options
.user
= xstrdup(pw
->pw_name
);
645 /* Get default port if port has not been set. */
646 if (options
.port
== 0) {
647 sp
= getservbyname(SSH_SERVICE_NAME
, "tcp");
648 options
.port
= sp
? ntohs(sp
->s_port
) : SSH_DEFAULT_PORT
;
651 if (options
.local_command
!= NULL
) {
652 char thishost
[NI_MAXHOST
];
654 if (gethostname(thishost
, sizeof(thishost
)) == -1)
655 fatal("gethostname: %s", strerror(errno
));
656 snprintf(buf
, sizeof(buf
), "%d", options
.port
);
657 debug3("expanding LocalCommand: %s", options
.local_command
);
658 cp
= options
.local_command
;
659 options
.local_command
= percent_expand(cp
, "d", pw
->pw_dir
,
660 "h", options
.hostname
? options
.hostname
: host
,
661 "l", thishost
, "n", host
, "r", options
.user
, "p", buf
,
662 "u", pw
->pw_name
, (char *)NULL
);
663 debug3("expanded LocalCommand: %s", options
.local_command
);
667 if (options
.hostname
!= NULL
)
668 host
= options
.hostname
;
670 /* Find canonic host name. */
671 if (strchr(host
, '.') == 0) {
672 struct addrinfo hints
;
673 struct addrinfo
*ai
= NULL
;
675 memset(&hints
, 0, sizeof(hints
));
676 hints
.ai_family
= options
.address_family
;
677 hints
.ai_flags
= AI_CANONNAME
;
678 hints
.ai_socktype
= SOCK_STREAM
;
679 errgai
= getaddrinfo(host
, NULL
, &hints
, &ai
);
681 if (ai
->ai_canonname
!= NULL
)
682 host
= xstrdup(ai
->ai_canonname
);
687 /* force lowercase for hostkey matching */
688 if (options
.host_key_alias
!= NULL
) {
689 for (p
= options
.host_key_alias
; *p
; p
++)
691 *p
= (char)tolower(*p
);
694 if (options
.proxy_command
!= NULL
&&
695 strcmp(options
.proxy_command
, "none") == 0) {
696 xfree(options
.proxy_command
);
697 options
.proxy_command
= NULL
;
699 if (options
.control_path
!= NULL
&&
700 strcmp(options
.control_path
, "none") == 0) {
701 xfree(options
.control_path
);
702 options
.control_path
= NULL
;
705 if (options
.control_path
!= NULL
) {
706 char thishost
[NI_MAXHOST
];
708 if (gethostname(thishost
, sizeof(thishost
)) == -1)
709 fatal("gethostname: %s", strerror(errno
));
710 snprintf(buf
, sizeof(buf
), "%d", options
.port
);
711 cp
= tilde_expand_filename(options
.control_path
,
713 xfree(options
.control_path
);
714 options
.control_path
= percent_expand(cp
, "p", buf
, "h", host
,
715 "r", options
.user
, "l", thishost
, (char *)NULL
);
718 if (muxclient_command
!= 0 && options
.control_path
== NULL
)
719 fatal("No ControlPath specified for \"-O\" command");
720 if (options
.control_path
!= NULL
)
721 muxclient(options
.control_path
);
723 timeout_ms
= options
.connection_timeout
* 1000;
725 /* Open a connection to the remote host. */
726 if (ssh_connect(host
, &hostaddr
, options
.port
,
727 options
.address_family
, options
.connection_attempts
, &timeout_ms
,
728 options
.tcp_keep_alive
,
730 options
.use_privileged_port
,
732 original_effective_uid
== 0 && options
.use_privileged_port
,
734 options
.proxy_command
) != 0)
738 debug3("timeout: %d ms remain after connect", timeout_ms
);
741 * If we successfully made the connection, load the host private key
742 * in case we will need it later for combined rsa-rhosts
743 * authentication. This must be done before releasing extra
744 * privileges, because the file is only readable by root.
745 * If we cannot access the private keys, load the public keys
746 * instead and try to execute the ssh-keysign helper instead.
748 sensitive_data
.nkeys
= 0;
749 sensitive_data
.keys
= NULL
;
750 sensitive_data
.external_keysign
= 0;
751 if (options
.rhosts_rsa_authentication
||
752 options
.hostbased_authentication
) {
753 sensitive_data
.nkeys
= 3;
754 sensitive_data
.keys
= xcalloc(sensitive_data
.nkeys
,
758 sensitive_data
.keys
[0] = key_load_private_type(KEY_RSA1
,
759 _PATH_HOST_KEY_FILE
, "", NULL
, NULL
);
760 sensitive_data
.keys
[1] = key_load_private_type(KEY_DSA
,
761 _PATH_HOST_DSA_KEY_FILE
, "", NULL
, NULL
);
762 sensitive_data
.keys
[2] = key_load_private_type(KEY_RSA
,
763 _PATH_HOST_RSA_KEY_FILE
, "", NULL
, NULL
);
766 if (options
.hostbased_authentication
== 1 &&
767 sensitive_data
.keys
[0] == NULL
&&
768 sensitive_data
.keys
[1] == NULL
&&
769 sensitive_data
.keys
[2] == NULL
) {
770 sensitive_data
.keys
[1] = key_load_public(
771 _PATH_HOST_DSA_KEY_FILE
, NULL
);
772 sensitive_data
.keys
[2] = key_load_public(
773 _PATH_HOST_RSA_KEY_FILE
, NULL
);
774 sensitive_data
.external_keysign
= 1;
778 * Get rid of any extra privileges that we may have. We will no
779 * longer need them. Also, extra privileges could make it very hard
780 * to read identity files and other non-world-readable files from the
781 * user's home directory if it happens to be on a NFS volume where
782 * root is mapped to nobody.
784 if (original_effective_uid
== 0) {
786 permanently_set_uid(pw
);
790 * Now that we are back to our own permissions, create ~/.ssh
791 * directory if it doesn't already exist.
793 r
= snprintf(buf
, sizeof buf
, "%s%s%s", pw
->pw_dir
,
794 strcmp(pw
->pw_dir
, "/") ? "/" : "", _PATH_SSH_USER_DIR
);
795 if (r
> 0 && (size_t)r
< sizeof(buf
) && stat(buf
, &st
) < 0)
796 if (mkdir(buf
, 0700) < 0)
797 error("Could not create directory '%.200s'.", buf
);
799 /* load options.identity_files */
800 load_public_identity_files();
802 /* Expand ~ in known host file names. */
804 options
.system_hostfile
=
805 tilde_expand_filename(options
.system_hostfile
, original_real_uid
);
806 options
.user_hostfile
=
807 tilde_expand_filename(options
.user_hostfile
, original_real_uid
);
808 options
.system_hostfile2
=
809 tilde_expand_filename(options
.system_hostfile2
, original_real_uid
);
810 options
.user_hostfile2
=
811 tilde_expand_filename(options
.user_hostfile2
, original_real_uid
);
813 signal(SIGPIPE
, SIG_IGN
); /* ignore SIGPIPE early */
815 /* Log into the remote system. Never returns if the login fails. */
816 ssh_login(&sensitive_data
, host
, (struct sockaddr
*)&hostaddr
,
819 /* We no longer need the private host keys. Clear them now. */
820 if (sensitive_data
.nkeys
!= 0) {
821 for (i
= 0; i
< sensitive_data
.nkeys
; i
++) {
822 if (sensitive_data
.keys
[i
] != NULL
) {
823 /* Destroys contents safely */
824 debug3("clear hostkey %d", i
);
825 key_free(sensitive_data
.keys
[i
]);
826 sensitive_data
.keys
[i
] = NULL
;
829 xfree(sensitive_data
.keys
);
831 for (i
= 0; i
< options
.num_identity_files
; i
++) {
832 if (options
.identity_files
[i
]) {
833 xfree(options
.identity_files
[i
]);
834 options
.identity_files
[i
] = NULL
;
836 if (options
.identity_keys
[i
]) {
837 key_free(options
.identity_keys
[i
]);
838 options
.identity_keys
[i
] = NULL
;
842 exit_status
= compat20
? ssh_session2() : ssh_session();
845 if (options
.control_path
!= NULL
&& muxserver_sock
!= -1)
846 unlink(options
.control_path
);
849 * Send SIGHUP to proxy command if used. We don't wait() in
850 * case it hangs and instead rely on init to reap the child
852 if (proxy_command_pid
> 1)
853 kill(proxy_command_pid
, SIGHUP
);
858 /* Callback for remote forward global requests */
860 ssh_confirm_remote_forward(int type
, u_int32_t seq
, void *ctxt
)
862 Forward
*rfwd
= (Forward
*)ctxt
;
864 /* XXX verbose() on failure? */
865 debug("remote forward %s for: listen %d, connect %s:%d",
866 type
== SSH2_MSG_REQUEST_SUCCESS
? "success" : "failure",
867 rfwd
->listen_port
, rfwd
->connect_host
, rfwd
->connect_port
);
868 if (type
== SSH2_MSG_REQUEST_SUCCESS
&& rfwd
->listen_port
== 0) {
869 logit("Allocated port %u for remote forward to %s:%d",
871 rfwd
->connect_host
, rfwd
->connect_port
);
874 if (type
== SSH2_MSG_REQUEST_FAILURE
) {
875 if (options
.exit_on_forward_failure
)
876 fatal("Error: remote port forwarding failed for "
877 "listen port %d", rfwd
->listen_port
);
879 logit("Warning: remote port forwarding failed for "
880 "listen port %d", rfwd
->listen_port
);
882 if (++remote_forward_confirms_received
== options
.num_remote_forwards
) {
883 debug("All remote forwarding requests processed");
884 if (fork_after_authentication_flag
) {
885 fork_after_authentication_flag
= 0;
886 if (daemon(1, 1) < 0)
887 fatal("daemon() failed: %.200s",
894 ssh_init_forwarding(void)
899 /* Initiate local TCP/IP port forwardings. */
900 for (i
= 0; i
< options
.num_local_forwards
; i
++) {
901 debug("Local connections to %.200s:%d forwarded to remote "
903 (options
.local_forwards
[i
].listen_host
== NULL
) ?
904 (options
.gateway_ports
? "*" : "LOCALHOST") :
905 options
.local_forwards
[i
].listen_host
,
906 options
.local_forwards
[i
].listen_port
,
907 options
.local_forwards
[i
].connect_host
,
908 options
.local_forwards
[i
].connect_port
);
909 success
+= channel_setup_local_fwd_listener(
910 options
.local_forwards
[i
].listen_host
,
911 options
.local_forwards
[i
].listen_port
,
912 options
.local_forwards
[i
].connect_host
,
913 options
.local_forwards
[i
].connect_port
,
914 options
.gateway_ports
);
916 if (i
> 0 && success
!= i
&& options
.exit_on_forward_failure
)
917 fatal("Could not request local forwarding.");
918 if (i
> 0 && success
== 0)
919 error("Could not request local forwarding.");
921 /* Initiate remote TCP/IP port forwardings. */
922 for (i
= 0; i
< options
.num_remote_forwards
; i
++) {
923 debug("Remote connections from %.200s:%d forwarded to "
924 "local address %.200s:%d",
925 (options
.remote_forwards
[i
].listen_host
== NULL
) ?
926 "LOCALHOST" : options
.remote_forwards
[i
].listen_host
,
927 options
.remote_forwards
[i
].listen_port
,
928 options
.remote_forwards
[i
].connect_host
,
929 options
.remote_forwards
[i
].connect_port
);
930 if (channel_request_remote_forwarding(
931 options
.remote_forwards
[i
].listen_host
,
932 options
.remote_forwards
[i
].listen_port
,
933 options
.remote_forwards
[i
].connect_host
,
934 options
.remote_forwards
[i
].connect_port
) < 0) {
935 if (options
.exit_on_forward_failure
)
936 fatal("Could not request remote forwarding.");
938 logit("Warning: Could not request remote "
941 client_register_global_confirm(ssh_confirm_remote_forward
,
942 &options
.remote_forwards
[i
]);
945 /* Initiate tunnel forwarding. */
946 if (options
.tun_open
!= SSH_TUNMODE_NO
) {
947 if (client_request_tun_fwd(options
.tun_open
,
948 options
.tun_local
, options
.tun_remote
) == -1) {
949 if (options
.exit_on_forward_failure
)
950 fatal("Could not request tunnel forwarding.");
952 error("Could not request tunnel forwarding.");
958 check_agent_present(void)
960 if (options
.forward_agent
) {
961 /* Clear agent forwarding if we don't have an agent. */
962 if (!ssh_agent_present())
963 options
.forward_agent
= 0;
977 /* Enable compression if requested. */
978 if (options
.compression
) {
979 debug("Requesting compression at level %d.",
980 options
.compression_level
);
982 if (options
.compression_level
< 1 ||
983 options
.compression_level
> 9)
984 fatal("Compression level must be from 1 (fast) to "
987 /* Send the request. */
988 packet_start(SSH_CMSG_REQUEST_COMPRESSION
);
989 packet_put_int(options
.compression_level
);
992 type
= packet_read();
993 if (type
== SSH_SMSG_SUCCESS
)
994 packet_start_compression(options
.compression_level
);
995 else if (type
== SSH_SMSG_FAILURE
)
996 logit("Warning: Remote host refused compression.");
998 packet_disconnect("Protocol error waiting for "
999 "compression response.");
1001 /* Allocate a pseudo tty if appropriate. */
1003 debug("Requesting pty.");
1005 /* Start the packet. */
1006 packet_start(SSH_CMSG_REQUEST_PTY
);
1008 /* Store TERM in the packet. There is no limit on the
1009 length of the string. */
1010 cp
= getenv("TERM");
1013 packet_put_cstring(cp
);
1015 /* Store window size in the packet. */
1016 if (ioctl(fileno(stdin
), TIOCGWINSZ
, &ws
) < 0)
1017 memset(&ws
, 0, sizeof(ws
));
1018 packet_put_int((u_int
)ws
.ws_row
);
1019 packet_put_int((u_int
)ws
.ws_col
);
1020 packet_put_int((u_int
)ws
.ws_xpixel
);
1021 packet_put_int((u_int
)ws
.ws_ypixel
);
1023 /* Store tty modes in the packet. */
1024 tty_make_modes(fileno(stdin
), NULL
);
1026 /* Send the packet, and wait for it to leave. */
1028 packet_write_wait();
1030 /* Read response from the server. */
1031 type
= packet_read();
1032 if (type
== SSH_SMSG_SUCCESS
) {
1035 } else if (type
== SSH_SMSG_FAILURE
)
1036 logit("Warning: Remote host failed or refused to "
1037 "allocate a pseudo tty.");
1039 packet_disconnect("Protocol error waiting for pty "
1040 "request response.");
1042 /* Request X11 forwarding if enabled and DISPLAY is set. */
1043 display
= getenv("DISPLAY");
1044 if (options
.forward_x11
&& display
!= NULL
) {
1046 /* Get reasonable local authentication information. */
1047 client_x11_get_proto(display
, options
.xauth_location
,
1048 options
.forward_x11_trusted
, &proto
, &data
);
1049 /* Request forwarding with authentication spoofing. */
1050 debug("Requesting X11 forwarding with authentication "
1052 x11_request_forwarding_with_spoofing(0, display
, proto
, data
);
1054 /* Read response from the server. */
1055 type
= packet_read();
1056 if (type
== SSH_SMSG_SUCCESS
) {
1058 } else if (type
== SSH_SMSG_FAILURE
) {
1059 logit("Warning: Remote host denied X11 forwarding.");
1061 packet_disconnect("Protocol error waiting for X11 "
1065 /* Tell the packet module whether this is an interactive session. */
1066 packet_set_interactive(interactive
);
1068 /* Request authentication agent forwarding if appropriate. */
1069 check_agent_present();
1071 if (options
.forward_agent
) {
1072 debug("Requesting authentication agent forwarding.");
1073 auth_request_forwarding();
1075 /* Read response from the server. */
1076 type
= packet_read();
1078 if (type
!= SSH_SMSG_SUCCESS
)
1079 logit("Warning: Remote host denied authentication agent forwarding.");
1082 /* Initiate port forwardings. */
1083 ssh_init_forwarding();
1085 /* Execute a local command */
1086 if (options
.local_command
!= NULL
&&
1087 options
.permit_local_command
)
1088 ssh_local_cmd(options
.local_command
);
1091 * If requested and we are not interested in replies to remote
1092 * forwarding requests, then let ssh continue in the background.
1094 if (fork_after_authentication_flag
&&
1095 (!options
.exit_on_forward_failure
||
1096 options
.num_remote_forwards
== 0)) {
1097 fork_after_authentication_flag
= 0;
1098 if (daemon(1, 1) < 0)
1099 fatal("daemon() failed: %.200s", strerror(errno
));
1103 * If a command was specified on the command line, execute the
1104 * command now. Otherwise request the server to start a shell.
1106 if (buffer_len(&command
) > 0) {
1107 int len
= buffer_len(&command
);
1110 debug("Sending command: %.*s", len
,
1111 (u_char
*)buffer_ptr(&command
));
1112 packet_start(SSH_CMSG_EXEC_CMD
);
1113 packet_put_string(buffer_ptr(&command
), buffer_len(&command
));
1115 packet_write_wait();
1117 debug("Requesting shell.");
1118 packet_start(SSH_CMSG_EXEC_SHELL
);
1120 packet_write_wait();
1123 /* Enter the interactive session. */
1124 return client_loop(have_tty
, tty_flag
?
1125 options
.escape_char
: SSH_ESCAPECHAR_NONE
, 0);
1128 /* request pty/x11/agent/tcpfwd/shell for channel */
1130 ssh_session2_setup(int id
, void *arg
)
1132 extern char **environ
;
1133 const char *display
;
1134 int interactive
= tty_flag
;
1136 display
= getenv("DISPLAY");
1137 if (options
.forward_x11
&& display
!= NULL
) {
1139 /* Get reasonable local authentication information. */
1140 client_x11_get_proto(display
, options
.xauth_location
,
1141 options
.forward_x11_trusted
, &proto
, &data
);
1142 /* Request forwarding with authentication spoofing. */
1143 debug("Requesting X11 forwarding with authentication "
1145 x11_request_forwarding_with_spoofing(id
, display
, proto
, data
);
1147 /* XXX wait for reply */
1150 check_agent_present();
1151 if (options
.forward_agent
) {
1152 debug("Requesting authentication agent forwarding.");
1153 channel_request_start(id
, "auth-agent-req@openssh.com", 0);
1157 client_session2_setup(id
, tty_flag
, subsystem_flag
, getenv("TERM"),
1158 NULL
, fileno(stdin
), &command
, environ
);
1160 packet_set_interactive(interactive
);
1163 /* open new channel for a session */
1165 ssh_session2_open(void)
1168 int window
, packetmax
, in
, out
, err
;
1171 int socksizelen
= sizeof(int);
1173 if (stdin_null_flag
) {
1174 in
= open(_PATH_DEVNULL
, O_RDONLY
);
1176 in
= dup(STDIN_FILENO
);
1178 out
= dup(STDOUT_FILENO
);
1179 err
= dup(STDERR_FILENO
);
1181 if (in
< 0 || out
< 0 || err
< 0)
1182 fatal("dup() in/out/err failed");
1184 /* enable nonblocking unless tty */
1192 /* we need to check to see if what they want to do about buffer */
1193 /* sizes here. In a hpn to nonhpn connection we want to limit */
1194 /* the window size to something reasonable in case the far side */
1195 /* has the large window bug. In hpn to hpn connection we want to */
1196 /* use the max window size but allow the user to override it */
1197 /* lastly if they disabled hpn then use the ssh std window size */
1199 /* so why don't we just do a getsockopt() here and set the */
1200 /* ssh window to that? In the case of a autotuning receive */
1201 /* window the window would get stuck at the initial buffer */
1202 /* size generally less than 96k. Therefore we need to set the */
1203 /* maximum ssh window size to the maximum hpn buffer size */
1204 /* unless the user has specifically set the tcprcvbufpoll */
1205 /* to no. In which case we *can* just set the window to the */
1206 /* minimum of the hpn buffer size and tcp receive buffer size */
1209 options
.hpn_buffer_size
= CHAN_SES_WINDOW_DEFAULT
;
1211 options
.hpn_buffer_size
= 2*1024*1024;
1213 if (datafellows
& SSH_BUG_LARGEWINDOW
)
1215 debug("HPN to Non-HPN Connection");
1219 if (options
.tcp_rcv_buf_poll
<= 0)
1221 sock
= socket(AF_INET
, SOCK_STREAM
, 0);
1222 getsockopt(sock
, SOL_SOCKET
, SO_RCVBUF
,
1223 &socksize
, &socksizelen
);
1225 debug("socksize %d", socksize
);
1226 options
.hpn_buffer_size
= socksize
;
1227 debug ("HPNBufferSize set to TCP RWIN: %d", options
.hpn_buffer_size
);
1231 if (options
.tcp_rcv_buf
> 0)
1233 /*create a socket but don't connect it */
1234 /* we use that the get the rcv socket size */
1235 sock
= socket(AF_INET
, SOCK_STREAM
, 0);
1236 /* if they are using the tcp_rcv_buf option */
1237 /* attempt to set the buffer size to that */
1238 if (options
.tcp_rcv_buf
)
1239 setsockopt(sock
, SOL_SOCKET
, SO_RCVBUF
, (void *)&options
.tcp_rcv_buf
,
1240 sizeof(options
.tcp_rcv_buf
));
1241 getsockopt(sock
, SOL_SOCKET
, SO_RCVBUF
,
1242 &socksize
, &socksizelen
);
1244 debug("socksize %d", socksize
);
1245 options
.hpn_buffer_size
= socksize
;
1246 debug ("HPNBufferSize set to user TCPRcvBuf: %d", options
.hpn_buffer_size
);
1252 debug("Final hpn_buffer_size = %d", options
.hpn_buffer_size
);
1254 window
= options
.hpn_buffer_size
;
1256 channel_set_hpn(options
.hpn_disabled
, options
.hpn_buffer_size
);
1258 packetmax
= CHAN_SES_PACKET_DEFAULT
;
1260 window
= 4*CHAN_SES_PACKET_DEFAULT
;
1265 "session", SSH_CHANNEL_OPENING
, in
, out
, err
,
1266 window
, packetmax
, CHAN_EXTENDED_WRITE
,
1267 "client-session", /*nonblock*/0);
1268 if ((options
.tcp_rcv_buf_poll
> 0) && (!options
.hpn_disabled
)) {
1269 c
->dynamic_window
= 1;
1270 debug ("Enabled Dynamic Window Scaling\n");
1272 debug3("ssh_session2_open: channel_new: %d", c
->self
);
1274 channel_send_open(c
->self
);
1276 channel_register_open_confirm(c
->self
,
1277 ssh_session2_setup
, NULL
);
1287 /* XXX should be pre-session */
1288 ssh_init_forwarding();
1290 if (!no_shell_flag
|| (datafellows
& SSH_BUG_DUMMYCHAN
))
1291 id
= ssh_session2_open();
1293 /* If we don't expect to open a new session, then disallow it */
1294 if (options
.control_master
== SSHCTL_MASTER_NO
&&
1295 (datafellows
& SSH_NEW_OPENSSH
)) {
1296 debug("Requesting no-more-sessions@openssh.com");
1297 packet_start(SSH2_MSG_GLOBAL_REQUEST
);
1298 packet_put_cstring("no-more-sessions@openssh.com");
1303 /* Execute a local command */
1304 if (options
.local_command
!= NULL
&&
1305 options
.permit_local_command
)
1306 ssh_local_cmd(options
.local_command
);
1308 /* Start listening for multiplex clients */
1311 /* If requested, let ssh continue in the background. */
1312 if (fork_after_authentication_flag
) {
1313 fork_after_authentication_flag
= 0;
1314 if (daemon(1, 1) < 0)
1315 fatal("daemon() failed: %.200s", strerror(errno
));
1318 return client_loop(tty_flag
, tty_flag
?
1319 options
.escape_char
: SSH_ESCAPECHAR_NONE
, id
);
1323 load_public_identity_files(void)
1325 char *filename
, *cp
, thishost
[NI_MAXHOST
];
1326 char *pwdir
= NULL
, *pwname
= NULL
;
1333 if (options
.smartcard_device
!= NULL
&&
1334 options
.num_identity_files
< SSH_MAX_IDENTITY_FILES
&&
1335 (keys
= sc_get_keys(options
.smartcard_device
, NULL
)) != NULL
) {
1337 for (i
= 0; keys
[i
] != NULL
; i
++) {
1339 memmove(&options
.identity_files
[1],
1340 &options
.identity_files
[0],
1341 sizeof(char *) * (SSH_MAX_IDENTITY_FILES
- 1));
1342 memmove(&options
.identity_keys
[1],
1343 &options
.identity_keys
[0],
1344 sizeof(Key
*) * (SSH_MAX_IDENTITY_FILES
- 1));
1345 options
.num_identity_files
++;
1346 options
.identity_keys
[0] = keys
[i
];
1347 options
.identity_files
[0] = sc_get_key_label(keys
[i
]);
1349 if (options
.num_identity_files
> SSH_MAX_IDENTITY_FILES
)
1350 options
.num_identity_files
= SSH_MAX_IDENTITY_FILES
;
1354 #endif /* SMARTCARD */
1355 if ((pw
= getpwuid(original_real_uid
)) == NULL
)
1356 fatal("load_public_identity_files: getpwuid failed");
1357 pwname
= xstrdup(pw
->pw_name
);
1358 pwdir
= xstrdup(pw
->pw_dir
);
1359 if (gethostname(thishost
, sizeof(thishost
)) == -1)
1360 fatal("load_public_identity_files: gethostname: %s",
1362 for (; i
< options
.num_identity_files
; i
++) {
1363 cp
= tilde_expand_filename(options
.identity_files
[i
],
1365 filename
= percent_expand(cp
, "d", pwdir
,
1366 "u", pwname
, "l", thishost
, "h", host
,
1367 "r", options
.user
, (char *)NULL
);
1369 public = key_load_public(filename
, NULL
);
1370 debug("identity file %s type %d", filename
,
1371 public ? public->type
: -1);
1372 xfree(options
.identity_files
[i
]);
1373 options
.identity_files
[i
] = filename
;
1374 options
.identity_keys
[i
] = public;
1376 bzero(pwname
, strlen(pwname
));
1378 bzero(pwdir
, strlen(pwdir
));