crypto: Revert some changes in contributed code.
[dragonfly.git] / crypto / openssh / ssh.c
CommitLineData
1c188a7f 1/* $OpenBSD: ssh.c,v 1.364 2011/08/02 23:15:03 djm Exp $ */
16c343f1
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2/*
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
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.
9 *
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".
15 *
16 * Copyright (c) 1999 Niels Provos. All rights reserved.
17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved.
18 *
19 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
20 * in Canada (German citizen).
21 *
22 * Redistribution and use in source and binary forms, with or without
23 * modification, are permitted provided that the following conditions
24 * are met:
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.
30 *
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.
41 */
42
43#include "includes.h"
44
45#include <sys/types.h>
46#ifdef HAVE_SYS_STAT_H
47# include <sys/stat.h>
48#endif
49#include <sys/resource.h>
50#include <sys/ioctl.h>
40c002af 51#include <sys/param.h>
16c343f1 52#include <sys/socket.h>
9f304aaf 53#include <sys/wait.h>
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54
55#include <ctype.h>
56#include <errno.h>
57#include <fcntl.h>
58#include <netdb.h>
59#ifdef HAVE_PATHS_H
60#include <paths.h>
61#endif
62#include <pwd.h>
63#include <signal.h>
64#include <stdarg.h>
65#include <stddef.h>
66#include <stdio.h>
67#include <stdlib.h>
68#include <string.h>
69#include <unistd.h>
70
71#include <netinet/in.h>
72#include <arpa/inet.h>
73
74#include <openssl/evp.h>
75#include <openssl/err.h>
76#include "openbsd-compat/openssl-compat.h"
c8c467ee 77#include "openbsd-compat/sys-queue.h"
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78
79#include "xmalloc.h"
80#include "ssh.h"
81#include "ssh1.h"
82#include "ssh2.h"
856ea928 83#include "canohost.h"
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84#include "compat.h"
85#include "cipher.h"
86#include "packet.h"
87#include "buffer.h"
88#include "channels.h"
89#include "key.h"
90#include "authfd.h"
91#include "authfile.h"
92#include "pathnames.h"
93#include "dispatch.h"
94#include "clientloop.h"
95#include "log.h"
96#include "readconf.h"
97#include "sshconnect.h"
98#include "misc.h"
99#include "kex.h"
100#include "mac.h"
101#include "sshpty.h"
102#include "match.h"
103#include "msg.h"
16c343f1 104#include "uidswap.h"
856ea928 105#include "roaming.h"
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106#include "version.h"
107
856ea928
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108#ifdef ENABLE_PKCS11
109#include "ssh-pkcs11.h"
16c343f1
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110#endif
111
112extern char *__progname;
113
1c188a7f
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114/* Saves a copy of argv for setproctitle emulation */
115#ifndef HAVE_SETPROCTITLE
116static char **saved_av;
117#endif
118
c8c467ee 119/* Flag indicating whether debug mode is on. May be set on the command line. */
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120int debug_flag = 0;
121
1c188a7f 122/* Flag indicating whether a tty should be requested */
16c343f1 123int tty_flag = 0;
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124
125/* don't exec a shell */
126int no_shell_flag = 0;
127
128/*
129 * Flag indicating that nothing should be read from stdin. This can be set
130 * on the command line.
131 */
132int stdin_null_flag = 0;
133
134/*
856ea928
PA
135 * Flag indicating that the current process should be backgrounded and
136 * a new slave launched in the foreground for ControlPersist.
137 */
138int need_controlpersist_detach = 0;
139
140/* Copies of flags for ControlPersist foreground slave */
1c188a7f 141int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty;
856ea928
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142
143/*
16c343f1
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144 * Flag indicating that ssh should fork after authentication. This is useful
145 * so that the passphrase can be entered manually, and then ssh goes to the
146 * background.
147 */
148int fork_after_authentication_flag = 0;
149
856ea928
PA
150/* forward stdio to remote host and port */
151char *stdio_forward_host = NULL;
152int stdio_forward_port = 0;
153
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154/*
155 * General data structure for command line options and options configurable
156 * in configuration files. See readconf.h.
157 */
158Options options;
159
160/* optional user configfile */
161char *config = NULL;
162
163/*
164 * Name of the host we are connecting to. This is the name given on the
165 * command line, or the HostName specified for the user-supplied name in a
166 * configuration file.
167 */
168char *host;
169
170/* socket address the host resolves to */
171struct sockaddr_storage hostaddr;
172
173/* Private host keys. */
174Sensitive sensitive_data;
175
176/* Original real UID. */
177uid_t original_real_uid;
178uid_t original_effective_uid;
179
180/* command to be executed */
181Buffer command;
182
183/* Should we execute a command or invoke a subsystem? */
184int subsystem_flag = 0;
185
186/* # of replies received for global requests */
c8c467ee 187static int remote_forward_confirms_received = 0;
16c343f1 188
c8c467ee
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189/* mux.c */
190extern int muxserver_sock;
191extern u_int muxclient_command;
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192
193/* Prints a help message to the user. This function never returns. */
194
195static void
196usage(void)
197{
198 fprintf(stderr,
cb5eb4f1 199"usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n"
16c343f1 200" [-D [bind_address:]port] [-e escape_char] [-F configfile]\n"
856ea928
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201" [-I pkcs11] [-i identity_file]\n"
202" [-L [bind_address:]port:host:hostport]\n"
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203" [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
204" [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
856ea928
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205" [-W host:port] [-w local_tun[:remote_tun]]\n"
206" [user@]hostname [command]\n"
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207 );
208 exit(255);
209}
210
211static int ssh_session(void);
212static int ssh_session2(void);
213static void load_public_identity_files(void);
9f304aaf 214static void main_sigchld_handler(int);
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215
216/* from muxclient.c */
217void muxclient(const char *);
218void muxserver_listen(void);
16c343f1 219
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220/* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */
221static void
222tilde_expand_paths(char **paths, u_int num_paths)
223{
224 u_int i;
225 char *cp;
226
227 for (i = 0; i < num_paths; i++) {
228 cp = tilde_expand_filename(paths[i], original_real_uid);
229 xfree(paths[i]);
230 paths[i] = cp;
231 }
232}
233
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234/*
235 * Main program for the ssh client.
236 */
237int
238main(int ac, char **av)
239{
40c002af 240 int i, r, opt, exit_status, use_syslog;
9f304aaf 241 char *p, *cp, *line, *argv0, buf[MAXPATHLEN], *host_arg;
1c188a7f 242 char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV];
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243 struct stat st;
244 struct passwd *pw;
245 int dummy, timeout_ms;
246 extern int optind, optreset;
247 extern char *optarg;
1c188a7f 248
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249 struct servent *sp;
250 Forward fwd;
251
252 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
253 sanitise_stdfd();
254
255 __progname = ssh_get_progname(av[0]);
1c188a7f
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256
257#ifndef HAVE_SETPROCTITLE
258 /* Prepare for later setproctitle emulation */
259 /* Save argv so it isn't clobbered by setproctitle() emulation */
260 saved_av = xcalloc(ac + 1, sizeof(*saved_av));
261 for (i = 0; i < ac; i++)
262 saved_av[i] = xstrdup(av[i]);
263 saved_av[i] = NULL;
264 compat_init_setproctitle(ac, av);
265 av = saved_av;
266#endif
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267
268 /*
856ea928
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269 * Discard other fds that are hanging around. These can cause problem
270 * with backgrounded ssh processes started by ControlPersist.
271 */
272 closefrom(STDERR_FILENO + 1);
273
274 /*
16c343f1
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275 * Save the original real uid. It will be needed later (uid-swapping
276 * may clobber the real uid).
277 */
278 original_real_uid = getuid();
279 original_effective_uid = geteuid();
280
281 /*
282 * Use uid-swapping to give up root privileges for the duration of
283 * option processing. We will re-instantiate the rights when we are
284 * ready to create the privileged port, and will permanently drop
285 * them when the port has been created (actually, when the connection
286 * has been made, as we may need to create the port several times).
287 */
288 PRIV_END;
289
290#ifdef HAVE_SETRLIMIT
291 /* If we are installed setuid root be careful to not drop core. */
292 if (original_real_uid != original_effective_uid) {
293 struct rlimit rlim;
294 rlim.rlim_cur = rlim.rlim_max = 0;
295 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
296 fatal("setrlimit failed: %.100s", strerror(errno));
297 }
298#endif
299 /* Get user data. */
300 pw = getpwuid(original_real_uid);
301 if (!pw) {
302 logit("You don't exist, go away!");
303 exit(255);
304 }
305 /* Take a copy of the returned structure. */
306 pw = pwcopy(pw);
307
308 /*
309 * Set our umask to something reasonable, as some files are created
310 * with the default umask. This will make them world-readable but
311 * writable only by the owner, which is ok for all files for which we
312 * don't set the modes explicitly.
313 */
314 umask(022);
315
c8c467ee
PA
316 /*
317 * Initialize option structure to indicate that no values have been
318 * set.
319 */
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320 initialize_options(&options);
321
322 /* Parse command-line arguments. */
323 host = NULL;
cb5eb4f1 324 use_syslog = 0;
40c002af 325 argv0 = av[0];
16c343f1
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326
327 again:
c8c467ee 328 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
856ea928 329 "ACD:F:I:KL:MNO:PR:S:TVw:W:XYy")) != -1) {
16c343f1
PA
330 switch (opt) {
331 case '1':
332 options.protocol = SSH_PROTO_1;
333 break;
334 case '2':
335 options.protocol = SSH_PROTO_2;
336 break;
337 case '4':
338 options.address_family = AF_INET;
339 break;
340 case '6':
341 options.address_family = AF_INET6;
342 break;
343 case 'n':
344 stdin_null_flag = 1;
345 break;
346 case 'f':
347 fork_after_authentication_flag = 1;
348 stdin_null_flag = 1;
349 break;
350 case 'x':
351 options.forward_x11 = 0;
352 break;
353 case 'X':
354 options.forward_x11 = 1;
355 break;
cb5eb4f1
PA
356 case 'y':
357 use_syslog = 1;
358 break;
16c343f1
PA
359 case 'Y':
360 options.forward_x11 = 1;
361 options.forward_x11_trusted = 1;
362 break;
363 case 'g':
364 options.gateway_ports = 1;
365 break;
366 case 'O':
856ea928
PA
367 if (stdio_forward_host != NULL)
368 fatal("Cannot specify multiplexing "
369 "command with -W");
370 else if (muxclient_command != 0)
371 fatal("Multiplexing command already specified");
16c343f1 372 if (strcmp(optarg, "check") == 0)
c8c467ee 373 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
856ea928
PA
374 else if (strcmp(optarg, "forward") == 0)
375 muxclient_command = SSHMUX_COMMAND_FORWARD;
16c343f1 376 else if (strcmp(optarg, "exit") == 0)
c8c467ee 377 muxclient_command = SSHMUX_COMMAND_TERMINATE;
1c188a7f
PA
378 else if (strcmp(optarg, "stop") == 0)
379 muxclient_command = SSHMUX_COMMAND_STOP;
16c343f1
PA
380 else
381 fatal("Invalid multiplex command.");
382 break;
383 case 'P': /* deprecated */
384 options.use_privileged_port = 0;
385 break;
386 case 'a':
387 options.forward_agent = 0;
388 break;
389 case 'A':
390 options.forward_agent = 1;
391 break;
392 case 'k':
393 options.gss_deleg_creds = 0;
394 break;
395 case 'K':
396 options.gss_authentication = 1;
397 options.gss_deleg_creds = 1;
398 break;
399 case 'i':
400 if (stat(optarg, &st) < 0) {
401 fprintf(stderr, "Warning: Identity file %s "
402 "not accessible: %s.\n", optarg,
403 strerror(errno));
404 break;
405 }
406 if (options.num_identity_files >=
407 SSH_MAX_IDENTITY_FILES)
408 fatal("Too many identity files specified "
409 "(max %d)", SSH_MAX_IDENTITY_FILES);
410 options.identity_files[options.num_identity_files++] =
411 xstrdup(optarg);
412 break;
413 case 'I':
856ea928
PA
414#ifdef ENABLE_PKCS11
415 options.pkcs11_provider = xstrdup(optarg);
16c343f1 416#else
856ea928 417 fprintf(stderr, "no support for PKCS#11.\n");
16c343f1
PA
418#endif
419 break;
420 case 't':
1c188a7f
PA
421 if (options.request_tty == REQUEST_TTY_YES)
422 options.request_tty = REQUEST_TTY_FORCE;
423 else
424 options.request_tty = REQUEST_TTY_YES;
16c343f1
PA
425 break;
426 case 'v':
427 if (debug_flag == 0) {
428 debug_flag = 1;
429 options.log_level = SYSLOG_LEVEL_DEBUG1;
430 } else {
431 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
432 options.log_level++;
433 break;
434 }
435 /* FALLTHROUGH */
436 case 'V':
437 fprintf(stderr, "%s, %s\n",
438 SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
439 if (opt == 'V')
440 exit(0);
441 break;
442 case 'w':
443 if (options.tun_open == -1)
444 options.tun_open = SSH_TUNMODE_DEFAULT;
445 options.tun_local = a2tun(optarg, &options.tun_remote);
446 if (options.tun_local == SSH_TUNID_ERR) {
c8c467ee
PA
447 fprintf(stderr,
448 "Bad tun device '%s'\n", optarg);
16c343f1
PA
449 exit(255);
450 }
451 break;
856ea928
PA
452 case 'W':
453 if (stdio_forward_host != NULL)
454 fatal("stdio forward already specified");
455 if (muxclient_command != 0)
456 fatal("Cannot specify stdio forward with -O");
457 if (parse_forward(&fwd, optarg, 1, 0)) {
458 stdio_forward_host = fwd.listen_host;
459 stdio_forward_port = fwd.listen_port;
460 xfree(fwd.connect_host);
461 } else {
462 fprintf(stderr,
463 "Bad stdio forwarding specification '%s'\n",
464 optarg);
465 exit(255);
466 }
1c188a7f 467 options.request_tty = REQUEST_TTY_NO;
856ea928
PA
468 no_shell_flag = 1;
469 options.clear_forwardings = 1;
470 options.exit_on_forward_failure = 1;
471 break;
16c343f1
PA
472 case 'q':
473 options.log_level = SYSLOG_LEVEL_QUIET;
474 break;
475 case 'e':
476 if (optarg[0] == '^' && optarg[2] == 0 &&
477 (u_char) optarg[1] >= 64 &&
478 (u_char) optarg[1] < 128)
479 options.escape_char = (u_char) optarg[1] & 31;
480 else if (strlen(optarg) == 1)
481 options.escape_char = (u_char) optarg[0];
482 else if (strcmp(optarg, "none") == 0)
483 options.escape_char = SSH_ESCAPECHAR_NONE;
484 else {
485 fprintf(stderr, "Bad escape character '%s'.\n",
486 optarg);
487 exit(255);
488 }
489 break;
490 case 'c':
491 if (ciphers_valid(optarg)) {
492 /* SSH2 only */
493 options.ciphers = xstrdup(optarg);
494 options.cipher = SSH_CIPHER_INVALID;
495 } else {
496 /* SSH1 only */
497 options.cipher = cipher_number(optarg);
498 if (options.cipher == -1) {
499 fprintf(stderr,
500 "Unknown cipher type '%s'\n",
501 optarg);
502 exit(255);
503 }
504 if (options.cipher == SSH_CIPHER_3DES)
505 options.ciphers = "3des-cbc";
506 else if (options.cipher == SSH_CIPHER_BLOWFISH)
507 options.ciphers = "blowfish-cbc";
508 else
509 options.ciphers = (char *)-1;
510 }
511 break;
512 case 'm':
513 if (mac_valid(optarg))
514 options.macs = xstrdup(optarg);
515 else {
516 fprintf(stderr, "Unknown mac type '%s'\n",
517 optarg);
518 exit(255);
519 }
520 break;
521 case 'M':
522 if (options.control_master == SSHCTL_MASTER_YES)
523 options.control_master = SSHCTL_MASTER_ASK;
524 else
525 options.control_master = SSHCTL_MASTER_YES;
526 break;
527 case 'p':
528 options.port = a2port(optarg);
cb5eb4f1 529 if (options.port <= 0) {
16c343f1
PA
530 fprintf(stderr, "Bad port '%s'\n", optarg);
531 exit(255);
532 }
533 break;
534 case 'l':
535 options.user = optarg;
536 break;
537
538 case 'L':
cb5eb4f1 539 if (parse_forward(&fwd, optarg, 0, 0))
16c343f1
PA
540 add_local_forward(&options, &fwd);
541 else {
542 fprintf(stderr,
543 "Bad local forwarding specification '%s'\n",
544 optarg);
545 exit(255);
546 }
547 break;
548
549 case 'R':
cb5eb4f1 550 if (parse_forward(&fwd, optarg, 0, 1)) {
16c343f1
PA
551 add_remote_forward(&options, &fwd);
552 } else {
553 fprintf(stderr,
554 "Bad remote forwarding specification "
555 "'%s'\n", optarg);
556 exit(255);
557 }
558 break;
559
560 case 'D':
cb5eb4f1
PA
561 if (parse_forward(&fwd, optarg, 1, 0)) {
562 add_local_forward(&options, &fwd);
16c343f1 563 } else {
cb5eb4f1
PA
564 fprintf(stderr,
565 "Bad dynamic forwarding specification "
566 "'%s'\n", optarg);
16c343f1
PA
567 exit(255);
568 }
16c343f1
PA
569 break;
570
571 case 'C':
572 options.compression = 1;
573 break;
574 case 'N':
575 no_shell_flag = 1;
1c188a7f 576 options.request_tty = REQUEST_TTY_NO;
16c343f1
PA
577 break;
578 case 'T':
1c188a7f 579 options.request_tty = REQUEST_TTY_NO;
ee295cbe
PA
580 /* ensure that the user doesn't try to backdoor a */
581 /* null cipher switch on an interactive session */
582 /* so explicitly disable it no matter what */
583 options.none_switch=0;
16c343f1 584 break;
16c343f1
PA
585 case 'o':
586 dummy = 1;
587 line = xstrdup(optarg);
588 if (process_config_line(&options, host ? host : "",
589 line, "command-line", 0, &dummy) != 0)
590 exit(255);
591 xfree(line);
592 break;
593 case 's':
594 subsystem_flag = 1;
595 break;
596 case 'S':
597 if (options.control_path != NULL)
598 free(options.control_path);
599 options.control_path = xstrdup(optarg);
600 break;
601 case 'b':
602 options.bind_address = optarg;
603 break;
604 case 'F':
605 config = optarg;
606 break;
607 default:
608 usage();
609 }
610 }
611
612 ac -= optind;
613 av += optind;
614
856ea928 615 if (ac > 0 && !host) {
16c343f1
PA
616 if (strrchr(*av, '@')) {
617 p = xstrdup(*av);
618 cp = strrchr(p, '@');
619 if (cp == NULL || cp == p)
620 usage();
621 options.user = p;
622 *cp = '\0';
623 host = ++cp;
624 } else
625 host = *av;
626 if (ac > 1) {
627 optind = optreset = 1;
628 goto again;
629 }
630 ac--, av++;
631 }
632
633 /* Check that we got a host name. */
634 if (!host)
635 usage();
636
9f304aaf 637 OpenSSL_add_all_algorithms();
16c343f1
PA
638 ERR_load_crypto_strings();
639
640 /* Initialize the command to execute on remote host. */
641 buffer_init(&command);
642
1c188a7f
PA
643 if (options.request_tty == REQUEST_TTY_YES ||
644 options.request_tty == REQUEST_TTY_FORCE)
645 tty_flag = 1;
646
16c343f1
PA
647 /*
648 * Save the command to execute on the remote host in a buffer. There
649 * is no limit on the length of the command, except by the maximum
650 * packet size. Also sets the tty flag if there is no command.
651 */
652 if (!ac) {
653 /* No command specified - execute shell on a tty. */
1c188a7f 654 tty_flag = options.request_tty != REQUEST_TTY_NO;
16c343f1
PA
655 if (subsystem_flag) {
656 fprintf(stderr,
657 "You must specify a subsystem to invoke.\n");
658 usage();
659 }
660 } else {
661 /* A command has been specified. Store it into the buffer. */
662 for (i = 0; i < ac; i++) {
663 if (i)
664 buffer_append(&command, " ", 1);
665 buffer_append(&command, av[i], strlen(av[i]));
666 }
667 }
668
669 /* Cannot fork to background if no command. */
c8c467ee
PA
670 if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
671 !no_shell_flag)
672 fatal("Cannot fork into background without a command "
673 "to execute.");
16c343f1
PA
674
675 /* Allocate a tty by default if no command specified. */
676 if (buffer_len(&command) == 0)
1c188a7f 677 tty_flag = options.request_tty != REQUEST_TTY_NO;
16c343f1
PA
678
679 /* Force no tty */
1c188a7f 680 if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0)
16c343f1
PA
681 tty_flag = 0;
682 /* Do not allocate a tty if stdin is not a tty. */
1c188a7f
PA
683 if ((!isatty(fileno(stdin)) || stdin_null_flag) &&
684 options.request_tty != REQUEST_TTY_FORCE) {
16c343f1 685 if (tty_flag)
c8c467ee
PA
686 logit("Pseudo-terminal will not be allocated because "
687 "stdin is not a terminal.");
16c343f1
PA
688 tty_flag = 0;
689 }
690
691 /*
692 * Initialize "log" output. Since we are the client all output
693 * actually goes to stderr.
694 */
40c002af 695 log_init(argv0,
c8c467ee 696 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
cb5eb4f1 697 SYSLOG_FACILITY_USER, !use_syslog);
16c343f1
PA
698
699 /*
700 * Read per-user configuration file. Ignore the system wide config
701 * file if the user specifies a config file on the command line.
702 */
703 if (config != NULL) {
704 if (!read_config_file(config, host, &options, 0))
705 fatal("Can't open user config file %.100s: "
706 "%.100s", config, strerror(errno));
707 } else {
40c002af 708 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
16c343f1 709 _PATH_SSH_USER_CONFFILE);
40c002af
PA
710 if (r > 0 && (size_t)r < sizeof(buf))
711 (void)read_config_file(buf, host, &options, 1);
16c343f1 712
1c188a7f 713 /* Read systemwide configuration file after user config. */
16c343f1
PA
714 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
715 &options, 0);
716 }
717
718 /* Fill configuration defaults. */
719 fill_default_options(&options);
720
721 channel_set_af(options.address_family);
722
723 /* reinit */
40c002af 724 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
16c343f1
PA
725
726 seed_rng();
727
728 if (options.user == NULL)
729 options.user = xstrdup(pw->pw_name);
730
c8c467ee
PA
731 /* Get default port if port has not been set. */
732 if (options.port == 0) {
733 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
734 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
735 }
736
9f304aaf
PA
737 /* preserve host name given on command line for %n expansion */
738 host_arg = host;
856ea928
PA
739 if (options.hostname != NULL) {
740 host = percent_expand(options.hostname,
741 "h", host, (char *)NULL);
742 }
743
1c188a7f
PA
744 if (gethostname(thishost, sizeof(thishost)) == -1)
745 fatal("gethostname: %s", strerror(errno));
746 strlcpy(shorthost, thishost, sizeof(shorthost));
747 shorthost[strcspn(thishost, ".")] = '\0';
748 snprintf(portstr, sizeof(portstr), "%d", options.port);
c8c467ee 749
1c188a7f 750 if (options.local_command != NULL) {
c8c467ee
PA
751 debug3("expanding LocalCommand: %s", options.local_command);
752 cp = options.local_command;
753 options.local_command = percent_expand(cp, "d", pw->pw_dir,
9f304aaf 754 "h", host, "l", thishost, "n", host_arg, "r", options.user,
1c188a7f
PA
755 "p", portstr, "u", pw->pw_name, "L", shorthost,
756 (char *)NULL);
c8c467ee
PA
757 debug3("expanded LocalCommand: %s", options.local_command);
758 xfree(cp);
759 }
760
16c343f1
PA
761 /* force lowercase for hostkey matching */
762 if (options.host_key_alias != NULL) {
763 for (p = options.host_key_alias; *p; p++)
764 if (isupper(*p))
765 *p = (char)tolower(*p);
766 }
767
16c343f1
PA
768 if (options.proxy_command != NULL &&
769 strcmp(options.proxy_command, "none") == 0) {
770 xfree(options.proxy_command);
771 options.proxy_command = NULL;
772 }
773 if (options.control_path != NULL &&
774 strcmp(options.control_path, "none") == 0) {
775 xfree(options.control_path);
776 options.control_path = NULL;
777 }
778
779 if (options.control_path != NULL) {
16c343f1
PA
780 cp = tilde_expand_filename(options.control_path,
781 original_real_uid);
782 xfree(options.control_path);
1c188a7f
PA
783 options.control_path = percent_expand(cp, "h", host,
784 "l", thishost, "n", host_arg, "r", options.user,
785 "p", portstr, "u", pw->pw_name, "L", shorthost,
786 (char *)NULL);
16c343f1
PA
787 xfree(cp);
788 }
c8c467ee 789 if (muxclient_command != 0 && options.control_path == NULL)
16c343f1
PA
790 fatal("No ControlPath specified for \"-O\" command");
791 if (options.control_path != NULL)
c8c467ee 792 muxclient(options.control_path);
16c343f1
PA
793
794 timeout_ms = options.connection_timeout * 1000;
795
796 /* Open a connection to the remote host. */
797 if (ssh_connect(host, &hostaddr, options.port,
798 options.address_family, options.connection_attempts, &timeout_ms,
799 options.tcp_keep_alive,
800#ifdef HAVE_CYGWIN
801 options.use_privileged_port,
802#else
803 original_effective_uid == 0 && options.use_privileged_port,
804#endif
805 options.proxy_command) != 0)
806 exit(255);
807
808 if (timeout_ms > 0)
809 debug3("timeout: %d ms remain after connect", timeout_ms);
810
811 /*
812 * If we successfully made the connection, load the host private key
813 * in case we will need it later for combined rsa-rhosts
814 * authentication. This must be done before releasing extra
815 * privileges, because the file is only readable by root.
816 * If we cannot access the private keys, load the public keys
817 * instead and try to execute the ssh-keysign helper instead.
818 */
819 sensitive_data.nkeys = 0;
820 sensitive_data.keys = NULL;
821 sensitive_data.external_keysign = 0;
822 if (options.rhosts_rsa_authentication ||
823 options.hostbased_authentication) {
9f304aaf 824 sensitive_data.nkeys = 7;
16c343f1
PA
825 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
826 sizeof(Key));
9f304aaf
PA
827 for (i = 0; i < sensitive_data.nkeys; i++)
828 sensitive_data.keys[i] = NULL;
16c343f1
PA
829
830 PRIV_START;
831 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
832 _PATH_HOST_KEY_FILE, "", NULL, NULL);
856ea928
PA
833 sensitive_data.keys[1] = key_load_private_cert(KEY_DSA,
834 _PATH_HOST_DSA_KEY_FILE, "", NULL);
9f304aaf
PA
835#ifdef OPENSSL_HAS_ECC
836 sensitive_data.keys[2] = key_load_private_cert(KEY_ECDSA,
837 _PATH_HOST_ECDSA_KEY_FILE, "", NULL);
838#endif
839 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA,
856ea928 840 _PATH_HOST_RSA_KEY_FILE, "", NULL);
9f304aaf 841 sensitive_data.keys[4] = key_load_private_type(KEY_DSA,
16c343f1 842 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
9f304aaf
PA
843#ifdef OPENSSL_HAS_ECC
844 sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA,
845 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL);
846#endif
847 sensitive_data.keys[6] = key_load_private_type(KEY_RSA,
16c343f1
PA
848 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
849 PRIV_END;
850
851 if (options.hostbased_authentication == 1 &&
852 sensitive_data.keys[0] == NULL &&
9f304aaf
PA
853 sensitive_data.keys[4] == NULL &&
854 sensitive_data.keys[5] == NULL &&
855 sensitive_data.keys[6] == NULL) {
856ea928
PA
856 sensitive_data.keys[1] = key_load_cert(
857 _PATH_HOST_DSA_KEY_FILE);
9f304aaf 858#ifdef OPENSSL_HAS_ECC
856ea928 859 sensitive_data.keys[2] = key_load_cert(
9f304aaf
PA
860 _PATH_HOST_ECDSA_KEY_FILE);
861#endif
862 sensitive_data.keys[3] = key_load_cert(
856ea928 863 _PATH_HOST_RSA_KEY_FILE);
856ea928 864 sensitive_data.keys[4] = key_load_public(
9f304aaf
PA
865 _PATH_HOST_DSA_KEY_FILE, NULL);
866#ifdef OPENSSL_HAS_ECC
867 sensitive_data.keys[5] = key_load_public(
868 _PATH_HOST_ECDSA_KEY_FILE, NULL);
869#endif
870 sensitive_data.keys[6] = key_load_public(
16c343f1
PA
871 _PATH_HOST_RSA_KEY_FILE, NULL);
872 sensitive_data.external_keysign = 1;
873 }
874 }
875 /*
876 * Get rid of any extra privileges that we may have. We will no
877 * longer need them. Also, extra privileges could make it very hard
878 * to read identity files and other non-world-readable files from the
879 * user's home directory if it happens to be on a NFS volume where
880 * root is mapped to nobody.
881 */
882 if (original_effective_uid == 0) {
883 PRIV_START;
884 permanently_set_uid(pw);
885 }
886
887 /*
888 * Now that we are back to our own permissions, create ~/.ssh
889 * directory if it doesn't already exist.
890 */
40c002af 891 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir,
c8c467ee 892 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
9f304aaf
PA
893 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) {
894#ifdef WITH_SELINUX
895 ssh_selinux_setfscreatecon(buf);
896#endif
16c343f1
PA
897 if (mkdir(buf, 0700) < 0)
898 error("Could not create directory '%.200s'.", buf);
9f304aaf
PA
899#ifdef WITH_SELINUX
900 ssh_selinux_setfscreatecon(NULL);
901#endif
902 }
16c343f1
PA
903 /* load options.identity_files */
904 load_public_identity_files();
905
906 /* Expand ~ in known host file names. */
1c188a7f
PA
907 tilde_expand_paths(options.system_hostfiles,
908 options.num_system_hostfiles);
909 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles);
16c343f1
PA
910
911 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
9f304aaf 912 signal(SIGCHLD, main_sigchld_handler);
16c343f1 913
c8c467ee 914 /* Log into the remote system. Never returns if the login fails. */
16c343f1 915 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
9f304aaf 916 options.port, pw, timeout_ms);
16c343f1 917
856ea928
PA
918 if (packet_connection_is_on_socket()) {
919 verbose("Authenticated to %s ([%s]:%d).", host,
920 get_remote_ipaddr(), get_remote_port());
921 } else {
922 verbose("Authenticated to %s (via proxy).", host);
923 }
924
16c343f1
PA
925 /* We no longer need the private host keys. Clear them now. */
926 if (sensitive_data.nkeys != 0) {
927 for (i = 0; i < sensitive_data.nkeys; i++) {
928 if (sensitive_data.keys[i] != NULL) {
929 /* Destroys contents safely */
930 debug3("clear hostkey %d", i);
931 key_free(sensitive_data.keys[i]);
932 sensitive_data.keys[i] = NULL;
933 }
934 }
935 xfree(sensitive_data.keys);
936 }
937 for (i = 0; i < options.num_identity_files; i++) {
938 if (options.identity_files[i]) {
939 xfree(options.identity_files[i]);
940 options.identity_files[i] = NULL;
941 }
942 if (options.identity_keys[i]) {
943 key_free(options.identity_keys[i]);
944 options.identity_keys[i] = NULL;
945 }
946 }
947
948 exit_status = compat20 ? ssh_session2() : ssh_session();
949 packet_close();
950
c8c467ee 951 if (options.control_path != NULL && muxserver_sock != -1)
16c343f1
PA
952 unlink(options.control_path);
953
9f304aaf
PA
954 /* Kill ProxyCommand if it is running. */
955 ssh_kill_proxy_command();
16c343f1
PA
956
957 return exit_status;
958}
959
856ea928
PA
960static void
961control_persist_detach(void)
962{
963 pid_t pid;
964 int devnull;
965
966 debug("%s: backgrounding master process", __func__);
967
968 /*
969 * master (current process) into the background, and make the
970 * foreground process a client of the backgrounded master.
971 */
972 switch ((pid = fork())) {
973 case -1:
974 fatal("%s: fork: %s", __func__, strerror(errno));
975 case 0:
976 /* Child: master process continues mainloop */
977 break;
978 default:
979 /* Parent: set up mux slave to connect to backgrounded master */
980 debug2("%s: background process is %ld", __func__, (long)pid);
981 stdin_null_flag = ostdin_null_flag;
1c188a7f 982 options.request_tty = orequest_tty;
856ea928
PA
983 tty_flag = otty_flag;
984 close(muxserver_sock);
985 muxserver_sock = -1;
9f304aaf 986 options.control_master = SSHCTL_MASTER_NO;
856ea928
PA
987 muxclient(options.control_path);
988 /* muxclient() doesn't return on success. */
989 fatal("Failed to connect to new control master");
990 }
991 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) {
992 error("%s: open(\"/dev/null\"): %s", __func__,
993 strerror(errno));
994 } else {
995 if (dup2(devnull, STDIN_FILENO) == -1 ||
996 dup2(devnull, STDOUT_FILENO) == -1)
997 error("%s: dup2: %s", __func__, strerror(errno));
998 if (devnull > STDERR_FILENO)
999 close(devnull);
1000 }
1c188a7f 1001 setproctitle("%s [mux]", options.control_path);
856ea928
PA
1002}
1003
1004/* Do fork() after authentication. Used by "ssh -f" */
1005static void
1006fork_postauth(void)
1007{
1008 if (need_controlpersist_detach)
1009 control_persist_detach();
1010 debug("forking to background");
1011 fork_after_authentication_flag = 0;
1012 if (daemon(1, 1) < 0)
1013 fatal("daemon() failed: %.200s", strerror(errno));
1014}
1015
c8c467ee
PA
1016/* Callback for remote forward global requests */
1017static void
1018ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
1019{
1020 Forward *rfwd = (Forward *)ctxt;
1021
cb5eb4f1 1022 /* XXX verbose() on failure? */
c8c467ee
PA
1023 debug("remote forward %s for: listen %d, connect %s:%d",
1024 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1025 rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
cb5eb4f1 1026 if (type == SSH2_MSG_REQUEST_SUCCESS && rfwd->listen_port == 0) {
856ea928 1027 rfwd->allocated_port = packet_get_int();
cb5eb4f1 1028 logit("Allocated port %u for remote forward to %s:%d",
856ea928
PA
1029 rfwd->allocated_port,
1030 rfwd->connect_host, rfwd->connect_port);
cb5eb4f1
PA
1031 }
1032
c8c467ee
PA
1033 if (type == SSH2_MSG_REQUEST_FAILURE) {
1034 if (options.exit_on_forward_failure)
1035 fatal("Error: remote port forwarding failed for "
1036 "listen port %d", rfwd->listen_port);
1037 else
1038 logit("Warning: remote port forwarding failed for "
1039 "listen port %d", rfwd->listen_port);
1040 }
1041 if (++remote_forward_confirms_received == options.num_remote_forwards) {
1042 debug("All remote forwarding requests processed");
856ea928
PA
1043 if (fork_after_authentication_flag)
1044 fork_postauth();
c8c467ee
PA
1045 }
1046}
1047
16c343f1 1048static void
856ea928
PA
1049client_cleanup_stdio_fwd(int id, void *arg)
1050{
1051 debug("stdio forwarding: done");
1052 cleanup_exit(0);
1053}
1054
1055static int
1056client_setup_stdio_fwd(const char *host_to_connect, u_short port_to_connect)
1057{
1058 Channel *c;
1059 int in, out;
1060
1061 debug3("client_setup_stdio_fwd %s:%d", host_to_connect,
1062 port_to_connect);
1063
1064 in = dup(STDIN_FILENO);
1065 out = dup(STDOUT_FILENO);
1066 if (in < 0 || out < 0)
1067 fatal("channel_connect_stdio_fwd: dup() in/out failed");
1068
1069 if ((c = channel_connect_stdio_fwd(host_to_connect, port_to_connect,
1070 in, out)) == NULL)
1071 return 0;
1072 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0);
1073 return 1;
1074}
1075
1076static void
16c343f1
PA
1077ssh_init_forwarding(void)
1078{
1079 int success = 0;
1080 int i;
1081
856ea928
PA
1082 if (stdio_forward_host != NULL) {
1083 if (!compat20) {
1084 fatal("stdio forwarding require Protocol 2");
1085 }
1086 if (!client_setup_stdio_fwd(stdio_forward_host,
1087 stdio_forward_port))
1088 fatal("Failed to connect in stdio forward mode.");
1089 }
1090
16c343f1
PA
1091 /* Initiate local TCP/IP port forwardings. */
1092 for (i = 0; i < options.num_local_forwards; i++) {
1093 debug("Local connections to %.200s:%d forwarded to remote "
1094 "address %.200s:%d",
1095 (options.local_forwards[i].listen_host == NULL) ?
1096 (options.gateway_ports ? "*" : "LOCALHOST") :
1097 options.local_forwards[i].listen_host,
1098 options.local_forwards[i].listen_port,
1099 options.local_forwards[i].connect_host,
1100 options.local_forwards[i].connect_port);
1101 success += channel_setup_local_fwd_listener(
1102 options.local_forwards[i].listen_host,
1103 options.local_forwards[i].listen_port,
1104 options.local_forwards[i].connect_host,
1105 options.local_forwards[i].connect_port,
1106 options.gateway_ports);
1107 }
1108 if (i > 0 && success != i && options.exit_on_forward_failure)
1109 fatal("Could not request local forwarding.");
1110 if (i > 0 && success == 0)
1111 error("Could not request local forwarding.");
1112
1113 /* Initiate remote TCP/IP port forwardings. */
1114 for (i = 0; i < options.num_remote_forwards; i++) {
1115 debug("Remote connections from %.200s:%d forwarded to "
1116 "local address %.200s:%d",
1117 (options.remote_forwards[i].listen_host == NULL) ?
1118 "LOCALHOST" : options.remote_forwards[i].listen_host,
1119 options.remote_forwards[i].listen_port,
1120 options.remote_forwards[i].connect_host,
1121 options.remote_forwards[i].connect_port);
1122 if (channel_request_remote_forwarding(
1123 options.remote_forwards[i].listen_host,
1124 options.remote_forwards[i].listen_port,
1125 options.remote_forwards[i].connect_host,
1126 options.remote_forwards[i].connect_port) < 0) {
1127 if (options.exit_on_forward_failure)
1128 fatal("Could not request remote forwarding.");
1129 else
1130 logit("Warning: Could not request remote "
1131 "forwarding.");
1132 }
c8c467ee
PA
1133 client_register_global_confirm(ssh_confirm_remote_forward,
1134 &options.remote_forwards[i]);
16c343f1
PA
1135 }
1136
1137 /* Initiate tunnel forwarding. */
1138 if (options.tun_open != SSH_TUNMODE_NO) {
1139 if (client_request_tun_fwd(options.tun_open,
1140 options.tun_local, options.tun_remote) == -1) {
1141 if (options.exit_on_forward_failure)
1142 fatal("Could not request tunnel forwarding.");
1143 else
1144 error("Could not request tunnel forwarding.");
1145 }
1146 }
1147}
1148
1149static void
1150check_agent_present(void)
1151{
1152 if (options.forward_agent) {
1153 /* Clear agent forwarding if we don't have an agent. */
1154 if (!ssh_agent_present())
1155 options.forward_agent = 0;
1156 }
1157}
1158
1159static int
1160ssh_session(void)
1161{
1162 int type;
1163 int interactive = 0;
1164 int have_tty = 0;
1165 struct winsize ws;
1166 char *cp;
1167 const char *display;
1168
1169 /* Enable compression if requested. */
1170 if (options.compression) {
c8c467ee
PA
1171 debug("Requesting compression at level %d.",
1172 options.compression_level);
16c343f1 1173
c8c467ee
PA
1174 if (options.compression_level < 1 ||
1175 options.compression_level > 9)
1176 fatal("Compression level must be from 1 (fast) to "
1177 "9 (slow, best).");
16c343f1
PA
1178
1179 /* Send the request. */
1180 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
1181 packet_put_int(options.compression_level);
1182 packet_send();
1183 packet_write_wait();
1184 type = packet_read();
1185 if (type == SSH_SMSG_SUCCESS)
1186 packet_start_compression(options.compression_level);
1187 else if (type == SSH_SMSG_FAILURE)
1188 logit("Warning: Remote host refused compression.");
1189 else
c8c467ee
PA
1190 packet_disconnect("Protocol error waiting for "
1191 "compression response.");
16c343f1
PA
1192 }
1193 /* Allocate a pseudo tty if appropriate. */
1194 if (tty_flag) {
1195 debug("Requesting pty.");
1196
1197 /* Start the packet. */
1198 packet_start(SSH_CMSG_REQUEST_PTY);
1199
1200 /* Store TERM in the packet. There is no limit on the
1201 length of the string. */
1202 cp = getenv("TERM");
1203 if (!cp)
1204 cp = "";
1205 packet_put_cstring(cp);
1206
1207 /* Store window size in the packet. */
1208 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
1209 memset(&ws, 0, sizeof(ws));
1210 packet_put_int((u_int)ws.ws_row);
1211 packet_put_int((u_int)ws.ws_col);
1212 packet_put_int((u_int)ws.ws_xpixel);
1213 packet_put_int((u_int)ws.ws_ypixel);
1214
1215 /* Store tty modes in the packet. */
1216 tty_make_modes(fileno(stdin), NULL);
1217
1218 /* Send the packet, and wait for it to leave. */
1219 packet_send();
1220 packet_write_wait();
1221
1222 /* Read response from the server. */
1223 type = packet_read();
1224 if (type == SSH_SMSG_SUCCESS) {
1225 interactive = 1;
1226 have_tty = 1;
1227 } else if (type == SSH_SMSG_FAILURE)
c8c467ee
PA
1228 logit("Warning: Remote host failed or refused to "
1229 "allocate a pseudo tty.");
16c343f1 1230 else
c8c467ee
PA
1231 packet_disconnect("Protocol error waiting for pty "
1232 "request response.");
16c343f1
PA
1233 }
1234 /* Request X11 forwarding if enabled and DISPLAY is set. */
1235 display = getenv("DISPLAY");
1236 if (options.forward_x11 && display != NULL) {
1237 char *proto, *data;
1238 /* Get reasonable local authentication information. */
1239 client_x11_get_proto(display, options.xauth_location,
856ea928
PA
1240 options.forward_x11_trusted,
1241 options.forward_x11_timeout,
1242 &proto, &data);
16c343f1 1243 /* Request forwarding with authentication spoofing. */
c8c467ee
PA
1244 debug("Requesting X11 forwarding with authentication "
1245 "spoofing.");
1c188a7f
PA
1246 x11_request_forwarding_with_spoofing(0, display, proto,
1247 data, 0);
16c343f1
PA
1248 /* Read response from the server. */
1249 type = packet_read();
1250 if (type == SSH_SMSG_SUCCESS) {
1251 interactive = 1;
1252 } else if (type == SSH_SMSG_FAILURE) {
1253 logit("Warning: Remote host denied X11 forwarding.");
1254 } else {
c8c467ee
PA
1255 packet_disconnect("Protocol error waiting for X11 "
1256 "forwarding");
16c343f1
PA
1257 }
1258 }
1259 /* Tell the packet module whether this is an interactive session. */
9f304aaf
PA
1260 packet_set_interactive(interactive,
1261 options.ip_qos_interactive, options.ip_qos_bulk);
16c343f1
PA
1262
1263 /* Request authentication agent forwarding if appropriate. */
1264 check_agent_present();
1265
1266 if (options.forward_agent) {
1267 debug("Requesting authentication agent forwarding.");
1268 auth_request_forwarding();
1269
1270 /* Read response from the server. */
1271 type = packet_read();
1272 packet_check_eom();
1273 if (type != SSH_SMSG_SUCCESS)
1274 logit("Warning: Remote host denied authentication agent forwarding.");
1275 }
1276
1277 /* Initiate port forwardings. */
1278 ssh_init_forwarding();
1279
1280 /* Execute a local command */
1281 if (options.local_command != NULL &&
1282 options.permit_local_command)
1283 ssh_local_cmd(options.local_command);
1284
c8c467ee
PA
1285 /*
1286 * If requested and we are not interested in replies to remote
1287 * forwarding requests, then let ssh continue in the background.
1288 */
856ea928
PA
1289 if (fork_after_authentication_flag) {
1290 if (options.exit_on_forward_failure &&
1291 options.num_remote_forwards > 0) {
1292 debug("deferring postauth fork until remote forward "
1293 "confirmation received");
1294 } else
1295 fork_postauth();
c8c467ee 1296 }
16c343f1
PA
1297
1298 /*
1299 * If a command was specified on the command line, execute the
1300 * command now. Otherwise request the server to start a shell.
1301 */
1302 if (buffer_len(&command) > 0) {
1303 int len = buffer_len(&command);
1304 if (len > 900)
1305 len = 900;
c8c467ee
PA
1306 debug("Sending command: %.*s", len,
1307 (u_char *)buffer_ptr(&command));
16c343f1
PA
1308 packet_start(SSH_CMSG_EXEC_CMD);
1309 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1310 packet_send();
1311 packet_write_wait();
1312 } else {
1313 debug("Requesting shell.");
1314 packet_start(SSH_CMSG_EXEC_SHELL);
1315 packet_send();
1316 packet_write_wait();
1317 }
1318
1319 /* Enter the interactive session. */
1320 return client_loop(have_tty, tty_flag ?
1321 options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1322}
1323
16c343f1
PA
1324/* request pty/x11/agent/tcpfwd/shell for channel */
1325static void
856ea928 1326ssh_session2_setup(int id, int success, void *arg)
16c343f1
PA
1327{
1328 extern char **environ;
1329 const char *display;
4b17c316 1330 int interactive = tty_flag;
16c343f1 1331
856ea928
PA
1332 if (!success)
1333 return; /* No need for error message, channels code sens one */
1334
16c343f1
PA
1335 display = getenv("DISPLAY");
1336 if (options.forward_x11 && display != NULL) {
1337 char *proto, *data;
1338 /* Get reasonable local authentication information. */
1339 client_x11_get_proto(display, options.xauth_location,
856ea928
PA
1340 options.forward_x11_trusted,
1341 options.forward_x11_timeout, &proto, &data);
16c343f1 1342 /* Request forwarding with authentication spoofing. */
c8c467ee
PA
1343 debug("Requesting X11 forwarding with authentication "
1344 "spoofing.");
1c188a7f
PA
1345 x11_request_forwarding_with_spoofing(id, display, proto,
1346 data, 1);
1347 client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN);
1348 /* XXX exit_on_forward_failure */
16c343f1 1349 interactive = 1;
16c343f1
PA
1350 }
1351
1352 check_agent_present();
1353 if (options.forward_agent) {
1354 debug("Requesting authentication agent forwarding.");
1355 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1356 packet_send();
1357 }
1358
1359 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
c8c467ee 1360 NULL, fileno(stdin), &command, environ);
16c343f1
PA
1361}
1362
1363/* open new channel for a session */
1364static int
1365ssh_session2_open(void)
1366{
1367 Channel *c;
1368 int window, packetmax, in, out, err;
c29cd1cc
PA
1369 int sock;
1370 int socksize;
1371 int socksizelen = sizeof(int);
16c343f1
PA
1372
1373 if (stdin_null_flag) {
1374 in = open(_PATH_DEVNULL, O_RDONLY);
1375 } else {
1376 in = dup(STDIN_FILENO);
1377 }
1378 out = dup(STDOUT_FILENO);
1379 err = dup(STDERR_FILENO);
1380
1381 if (in < 0 || out < 0 || err < 0)
1382 fatal("dup() in/out/err failed");
1383
1384 /* enable nonblocking unless tty */
1385 if (!isatty(in))
1386 set_nonblock(in);
1387 if (!isatty(out))
1388 set_nonblock(out);
1389 if (!isatty(err))
1390 set_nonblock(err);
1391
c29cd1cc
PA
1392 /* we need to check to see if what they want to do about buffer */
1393 /* sizes here. In a hpn to nonhpn connection we want to limit */
1394 /* the window size to something reasonable in case the far side */
1395 /* has the large window bug. In hpn to hpn connection we want to */
1396 /* use the max window size but allow the user to override it */
1397 /* lastly if they disabled hpn then use the ssh std window size */
1398
1399 /* so why don't we just do a getsockopt() here and set the */
1400 /* ssh window to that? In the case of a autotuning receive */
1401 /* window the window would get stuck at the initial buffer */
1402 /* size generally less than 96k. Therefore we need to set the */
1403 /* maximum ssh window size to the maximum hpn buffer size */
1404 /* unless the user has specifically set the tcprcvbufpoll */
1405 /* to no. In which case we *can* just set the window to the */
1406 /* minimum of the hpn buffer size and tcp receive buffer size */
1407
1408 if (tty_flag)
1409 options.hpn_buffer_size = CHAN_SES_WINDOW_DEFAULT;
1410 else
1411 options.hpn_buffer_size = 2*1024*1024;
1412
1413 if (datafellows & SSH_BUG_LARGEWINDOW)
1414 {
1415 debug("HPN to Non-HPN Connection");
1416 }
1417 else
1418 {
1419 if (options.tcp_rcv_buf_poll <= 0)
1420 {
1421 sock = socket(AF_INET, SOCK_STREAM, 0);
1422 getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1423 &socksize, &socksizelen);
1424 close(sock);
1425 debug("socksize %d", socksize);
1426 options.hpn_buffer_size = socksize;
1427 debug ("HPNBufferSize set to TCP RWIN: %d", options.hpn_buffer_size);
1428 }
1429 else
1430 {
1431 if (options.tcp_rcv_buf > 0)
1432 {
1433 /*create a socket but don't connect it */
1434 /* we use that the get the rcv socket size */
1435 sock = socket(AF_INET, SOCK_STREAM, 0);
1436 /* if they are using the tcp_rcv_buf option */
1437 /* attempt to set the buffer size to that */
1438 if (options.tcp_rcv_buf)
1439 setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void *)&options.tcp_rcv_buf,
1440 sizeof(options.tcp_rcv_buf));
1441 getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1442 &socksize, &socksizelen);
1443 close(sock);
1444 debug("socksize %d", socksize);
1445 options.hpn_buffer_size = socksize;
1446 debug ("HPNBufferSize set to user TCPRcvBuf: %d", options.hpn_buffer_size);
1447 }
1448 }
1449
1450 }
1451
1452 debug("Final hpn_buffer_size = %d", options.hpn_buffer_size);
1453
1454 window = options.hpn_buffer_size;
1455
1456 channel_set_hpn(options.hpn_disabled, options.hpn_buffer_size);
1457
16c343f1
PA
1458 packetmax = CHAN_SES_PACKET_DEFAULT;
1459 if (tty_flag) {
c29cd1cc 1460 window = 4*CHAN_SES_PACKET_DEFAULT;
16c343f1
PA
1461 window >>= 1;
1462 packetmax >>= 1;
1463 }
1464 c = channel_new(
1465 "session", SSH_CHANNEL_OPENING, in, out, err,
1466 window, packetmax, CHAN_EXTENDED_WRITE,
1467 "client-session", /*nonblock*/0);
c29cd1cc
PA
1468 if ((options.tcp_rcv_buf_poll > 0) && (!options.hpn_disabled)) {
1469 c->dynamic_window = 1;
1470 debug ("Enabled Dynamic Window Scaling\n");
1471 }
16c343f1
PA
1472 debug3("ssh_session2_open: channel_new: %d", c->self);
1473
1474 channel_send_open(c->self);
1475 if (!no_shell_flag)
c8c467ee
PA
1476 channel_register_open_confirm(c->self,
1477 ssh_session2_setup, NULL);
16c343f1
PA
1478
1479 return c->self;
1480}
1481
1482static int
1483ssh_session2(void)
1484{
1485 int id = -1;
1486
1487 /* XXX should be pre-session */
1488 ssh_init_forwarding();
1489
856ea928
PA
1490 /* Start listening for multiplex clients */
1491 muxserver_listen();
1492
1493 /*
1494 * If we are in control persist mode, then prepare to background
1495 * ourselves and have a foreground client attach as a control
1496 * slave. NB. we must save copies of the flags that we override for
1497 * the backgrounding, since we defer attachment of the slave until
1498 * after the connection is fully established (in particular,
1499 * async rfwd replies have been received for ExitOnForwardFailure).
1500 */
1501 if (options.control_persist && muxserver_sock != -1) {
1502 ostdin_null_flag = stdin_null_flag;
1503 ono_shell_flag = no_shell_flag;
1c188a7f 1504 orequest_tty = options.request_tty;
856ea928
PA
1505 otty_flag = tty_flag;
1506 stdin_null_flag = 1;
1507 no_shell_flag = 1;
856ea928
PA
1508 tty_flag = 0;
1509 if (!fork_after_authentication_flag)
1510 need_controlpersist_detach = 1;
1511 fork_after_authentication_flag = 1;
1512 }
1513
16c343f1
PA
1514 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1515 id = ssh_session2_open();
1516
c8c467ee 1517 /* If we don't expect to open a new session, then disallow it */
cb5eb4f1
PA
1518 if (options.control_master == SSHCTL_MASTER_NO &&
1519 (datafellows & SSH_NEW_OPENSSH)) {
c8c467ee
PA
1520 debug("Requesting no-more-sessions@openssh.com");
1521 packet_start(SSH2_MSG_GLOBAL_REQUEST);
1522 packet_put_cstring("no-more-sessions@openssh.com");
1523 packet_put_char(0);
1524 packet_send();
1525 }
1526
16c343f1
PA
1527 /* Execute a local command */
1528 if (options.local_command != NULL &&
1529 options.permit_local_command)
1530 ssh_local_cmd(options.local_command);
1531
856ea928
PA
1532 /*
1533 * If requested and we are not interested in replies to remote
1534 * forwarding requests, then let ssh continue in the background.
1535 */
c8c467ee 1536 if (fork_after_authentication_flag) {
856ea928
PA
1537 if (options.exit_on_forward_failure &&
1538 options.num_remote_forwards > 0) {
1539 debug("deferring postauth fork until remote forward "
1540 "confirmation received");
1541 } else
1542 fork_postauth();
c8c467ee 1543 }
16c343f1 1544
856ea928
PA
1545 if (options.use_roaming)
1546 request_roaming();
1547
16c343f1
PA
1548 return client_loop(tty_flag, tty_flag ?
1549 options.escape_char : SSH_ESCAPECHAR_NONE, id);
1550}
1551
1552static void
1553load_public_identity_files(void)
1554{
1555 char *filename, *cp, thishost[NI_MAXHOST];
1556 char *pwdir = NULL, *pwname = NULL;
1557 int i = 0;
1558 Key *public;
1559 struct passwd *pw;
856ea928
PA
1560 u_int n_ids;
1561 char *identity_files[SSH_MAX_IDENTITY_FILES];
1562 Key *identity_keys[SSH_MAX_IDENTITY_FILES];
1563#ifdef ENABLE_PKCS11
16c343f1 1564 Key **keys;
856ea928
PA
1565 int nkeys;
1566#endif /* PKCS11 */
16c343f1 1567
856ea928
PA
1568 n_ids = 0;
1569 bzero(identity_files, sizeof(identity_files));
1570 bzero(identity_keys, sizeof(identity_keys));
16c343f1 1571
856ea928
PA
1572#ifdef ENABLE_PKCS11
1573 if (options.pkcs11_provider != NULL &&
16c343f1 1574 options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
856ea928
PA
1575 (pkcs11_init(!options.batch_mode) == 0) &&
1576 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL,
1577 &keys)) > 0) {
1578 for (i = 0; i < nkeys; i++) {
1579 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
1580 key_free(keys[i]);
1581 continue;
1582 }
1583 identity_keys[n_ids] = keys[i];
1584 identity_files[n_ids] =
1585 xstrdup(options.pkcs11_provider); /* XXX */
1586 n_ids++;
16c343f1 1587 }
16c343f1
PA
1588 xfree(keys);
1589 }
856ea928 1590#endif /* ENABLE_PKCS11 */
16c343f1
PA
1591 if ((pw = getpwuid(original_real_uid)) == NULL)
1592 fatal("load_public_identity_files: getpwuid failed");
1593 pwname = xstrdup(pw->pw_name);
1594 pwdir = xstrdup(pw->pw_dir);
1595 if (gethostname(thishost, sizeof(thishost)) == -1)
1596 fatal("load_public_identity_files: gethostname: %s",
1597 strerror(errno));
856ea928
PA
1598 for (i = 0; i < options.num_identity_files; i++) {
1599 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
1600 xfree(options.identity_files[i]);
1601 continue;
1602 }
16c343f1
PA
1603 cp = tilde_expand_filename(options.identity_files[i],
1604 original_real_uid);
1605 filename = percent_expand(cp, "d", pwdir,
1606 "u", pwname, "l", thishost, "h", host,
1607 "r", options.user, (char *)NULL);
1608 xfree(cp);
1609 public = key_load_public(filename, NULL);
1610 debug("identity file %s type %d", filename,
1611 public ? public->type : -1);
1612 xfree(options.identity_files[i]);
856ea928
PA
1613 identity_files[n_ids] = filename;
1614 identity_keys[n_ids] = public;
1615
1616 if (++n_ids >= SSH_MAX_IDENTITY_FILES)
1617 continue;
1618
1619 /* Try to add the certificate variant too */
1620 xasprintf(&cp, "%s-cert", filename);
1621 public = key_load_public(cp, NULL);
1622 debug("identity file %s type %d", cp,
1623 public ? public->type : -1);
1624 if (public == NULL) {
1625 xfree(cp);
1626 continue;
1627 }
1628 if (!key_is_cert(public)) {
1629 debug("%s: key %s type %s is not a certificate",
1630 __func__, cp, key_type(public));
1631 key_free(public);
1632 xfree(cp);
1633 continue;
1634 }
1635 identity_keys[n_ids] = public;
1636 /* point to the original path, most likely the private key */
1637 identity_files[n_ids] = xstrdup(filename);
1638 n_ids++;
16c343f1 1639 }
856ea928
PA
1640 options.num_identity_files = n_ids;
1641 memcpy(options.identity_files, identity_files, sizeof(identity_files));
1642 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys));
1643
16c343f1
PA
1644 bzero(pwname, strlen(pwname));
1645 xfree(pwname);
1646 bzero(pwdir, strlen(pwdir));
1647 xfree(pwdir);
1648}
9f304aaf
PA
1649
1650static void
1651main_sigchld_handler(int sig)
1652{
1653 int save_errno = errno;
1654 pid_t pid;
1655 int status;
1656
1657 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
1658 (pid < 0 && errno == EINTR))
1659 ;
1660
1661 signal(sig, main_sigchld_handler);
1662 errno = save_errno;
1663}
1664