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1 | /* $OpenBSD: ssh.c,v 1.305 2007/10/29 06:54:50 dtucker Exp $ */ | |
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> | |
51 | #include <sys/socket.h> | |
52 | #include <sys/un.h> | |
53 | ||
54 | #include <ctype.h> | |
55 | #include <errno.h> | |
56 | #include <fcntl.h> | |
57 | #include <netdb.h> | |
58 | #ifdef HAVE_PATHS_H | |
59 | #include <paths.h> | |
60 | #endif | |
61 | #include <pwd.h> | |
62 | #include <signal.h> | |
63 | #include <stdarg.h> | |
64 | #include <stddef.h> | |
65 | #include <stdio.h> | |
66 | #include <stdlib.h> | |
67 | #include <string.h> | |
68 | #include <unistd.h> | |
69 | ||
70 | #include <netinet/in.h> | |
71 | #include <arpa/inet.h> | |
72 | ||
73 | #include <openssl/evp.h> | |
74 | #include <openssl/err.h> | |
75 | ||
76 | #include "xmalloc.h" | |
77 | #include "ssh.h" | |
78 | #include "ssh1.h" | |
79 | #include "ssh2.h" | |
80 | #include "compat.h" | |
81 | #include "cipher.h" | |
82 | #include "packet.h" | |
83 | #include "buffer.h" | |
84 | #include "channels.h" | |
85 | #include "key.h" | |
86 | #include "authfd.h" | |
87 | #include "authfile.h" | |
88 | #include "pathnames.h" | |
89 | #include "dispatch.h" | |
90 | #include "clientloop.h" | |
91 | #include "log.h" | |
92 | #include "readconf.h" | |
93 | #include "sshconnect.h" | |
94 | #include "misc.h" | |
95 | #include "kex.h" | |
96 | #include "mac.h" | |
97 | #include "sshpty.h" | |
98 | #include "match.h" | |
99 | #include "msg.h" | |
100 | #include "monitor_fdpass.h" | |
101 | #include "uidswap.h" | |
102 | #include "version.h" | |
103 | ||
104 | #ifdef SMARTCARD | |
105 | #include "scard.h" | |
106 | #endif | |
107 | ||
108 | extern char *__progname; | |
109 | ||
110 | /* Flag indicating whether debug mode is on. This can be set on the command line. */ | |
111 | int debug_flag = 0; | |
112 | ||
113 | /* Flag indicating whether a tty should be allocated */ | |
114 | int tty_flag = 0; | |
115 | int no_tty_flag = 0; | |
116 | int force_tty_flag = 0; | |
117 | ||
118 | /* don't exec a shell */ | |
119 | int no_shell_flag = 0; | |
120 | ||
121 | /* | |
122 | * Flag indicating that nothing should be read from stdin. This can be set | |
123 | * on the command line. | |
124 | */ | |
125 | int stdin_null_flag = 0; | |
126 | ||
127 | /* | |
128 | * Flag indicating that ssh should fork after authentication. This is useful | |
129 | * so that the passphrase can be entered manually, and then ssh goes to the | |
130 | * background. | |
131 | */ | |
132 | int fork_after_authentication_flag = 0; | |
133 | ||
134 | /* | |
135 | * General data structure for command line options and options configurable | |
136 | * in configuration files. See readconf.h. | |
137 | */ | |
138 | Options options; | |
139 | ||
140 | /* optional user configfile */ | |
141 | char *config = NULL; | |
142 | ||
143 | /* | |
144 | * Name of the host we are connecting to. This is the name given on the | |
145 | * command line, or the HostName specified for the user-supplied name in a | |
146 | * configuration file. | |
147 | */ | |
148 | char *host; | |
149 | ||
150 | /* socket address the host resolves to */ | |
151 | struct sockaddr_storage hostaddr; | |
152 | ||
153 | /* Private host keys. */ | |
154 | Sensitive sensitive_data; | |
155 | ||
156 | /* Original real UID. */ | |
157 | uid_t original_real_uid; | |
158 | uid_t original_effective_uid; | |
159 | ||
160 | /* command to be executed */ | |
161 | Buffer command; | |
162 | ||
163 | /* Should we execute a command or invoke a subsystem? */ | |
164 | int subsystem_flag = 0; | |
165 | ||
166 | /* # of replies received for global requests */ | |
167 | static int client_global_request_id = 0; | |
168 | ||
169 | /* pid of proxycommand child process */ | |
170 | pid_t proxy_command_pid = 0; | |
171 | ||
172 | /* fd to control socket */ | |
173 | int control_fd = -1; | |
174 | ||
175 | /* Multiplexing control command */ | |
176 | static u_int mux_command = 0; | |
177 | ||
178 | /* Only used in control client mode */ | |
179 | volatile sig_atomic_t control_client_terminate = 0; | |
180 | u_int control_server_pid = 0; | |
181 | ||
182 | /* Prints a help message to the user. This function never returns. */ | |
183 | ||
184 | static void | |
185 | usage(void) | |
186 | { | |
187 | fprintf(stderr, | |
188 | "usage: ssh [-1246AaCfgKkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n" | |
189 | " [-D [bind_address:]port] [-e escape_char] [-F configfile]\n" | |
190 | " [-i identity_file] [-L [bind_address:]port:host:hostport]\n" | |
191 | " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" | |
192 | " [-R [bind_address:]port:host:hostport] [-S ctl_path]\n" | |
193 | " [-w local_tun[:remote_tun]] [user@]hostname [command]\n" | |
194 | ); | |
195 | exit(255); | |
196 | } | |
197 | ||
198 | static int ssh_session(void); | |
199 | static int ssh_session2(void); | |
200 | static void load_public_identity_files(void); | |
201 | static void control_client(const char *path); | |
202 | ||
203 | /* | |
204 | * Main program for the ssh client. | |
205 | */ | |
206 | int | |
207 | main(int ac, char **av) | |
208 | { | |
209 | int i, opt, exit_status; | |
210 | char *p, *cp, *line, buf[256]; | |
211 | struct stat st; | |
212 | struct passwd *pw; | |
213 | int dummy, timeout_ms; | |
214 | extern int optind, optreset; | |
215 | extern char *optarg; | |
216 | struct servent *sp; | |
217 | Forward fwd; | |
218 | ||
219 | /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ | |
220 | sanitise_stdfd(); | |
221 | ||
222 | __progname = ssh_get_progname(av[0]); | |
223 | init_rng(); | |
224 | ||
225 | /* | |
226 | * Save the original real uid. It will be needed later (uid-swapping | |
227 | * may clobber the real uid). | |
228 | */ | |
229 | original_real_uid = getuid(); | |
230 | original_effective_uid = geteuid(); | |
231 | ||
232 | /* | |
233 | * Use uid-swapping to give up root privileges for the duration of | |
234 | * option processing. We will re-instantiate the rights when we are | |
235 | * ready to create the privileged port, and will permanently drop | |
236 | * them when the port has been created (actually, when the connection | |
237 | * has been made, as we may need to create the port several times). | |
238 | */ | |
239 | PRIV_END; | |
240 | ||
241 | #ifdef HAVE_SETRLIMIT | |
242 | /* If we are installed setuid root be careful to not drop core. */ | |
243 | if (original_real_uid != original_effective_uid) { | |
244 | struct rlimit rlim; | |
245 | rlim.rlim_cur = rlim.rlim_max = 0; | |
246 | if (setrlimit(RLIMIT_CORE, &rlim) < 0) | |
247 | fatal("setrlimit failed: %.100s", strerror(errno)); | |
248 | } | |
249 | #endif | |
250 | /* Get user data. */ | |
251 | pw = getpwuid(original_real_uid); | |
252 | if (!pw) { | |
253 | logit("You don't exist, go away!"); | |
254 | exit(255); | |
255 | } | |
256 | /* Take a copy of the returned structure. */ | |
257 | pw = pwcopy(pw); | |
258 | ||
259 | /* | |
260 | * Set our umask to something reasonable, as some files are created | |
261 | * with the default umask. This will make them world-readable but | |
262 | * writable only by the owner, which is ok for all files for which we | |
263 | * don't set the modes explicitly. | |
264 | */ | |
265 | umask(022); | |
266 | ||
267 | /* Initialize option structure to indicate that no values have been set. */ | |
268 | initialize_options(&options); | |
269 | ||
270 | /* Parse command-line arguments. */ | |
271 | host = NULL; | |
272 | ||
273 | again: | |
274 | while ((opt = getopt(ac, av, | |
275 | "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:KL:MNO:PR:S:TVw:XY")) != -1) { | |
276 | switch (opt) { | |
277 | case '1': | |
278 | options.protocol = SSH_PROTO_1; | |
279 | break; | |
280 | case '2': | |
281 | options.protocol = SSH_PROTO_2; | |
282 | break; | |
283 | case '4': | |
284 | options.address_family = AF_INET; | |
285 | break; | |
286 | case '6': | |
287 | options.address_family = AF_INET6; | |
288 | break; | |
289 | case 'n': | |
290 | stdin_null_flag = 1; | |
291 | break; | |
292 | case 'f': | |
293 | fork_after_authentication_flag = 1; | |
294 | stdin_null_flag = 1; | |
295 | break; | |
296 | case 'x': | |
297 | options.forward_x11 = 0; | |
298 | break; | |
299 | case 'X': | |
300 | options.forward_x11 = 1; | |
301 | break; | |
302 | case 'Y': | |
303 | options.forward_x11 = 1; | |
304 | options.forward_x11_trusted = 1; | |
305 | break; | |
306 | case 'g': | |
307 | options.gateway_ports = 1; | |
308 | break; | |
309 | case 'O': | |
310 | if (strcmp(optarg, "check") == 0) | |
311 | mux_command = SSHMUX_COMMAND_ALIVE_CHECK; | |
312 | else if (strcmp(optarg, "exit") == 0) | |
313 | mux_command = SSHMUX_COMMAND_TERMINATE; | |
314 | else | |
315 | fatal("Invalid multiplex command."); | |
316 | break; | |
317 | case 'P': /* deprecated */ | |
318 | options.use_privileged_port = 0; | |
319 | break; | |
320 | case 'a': | |
321 | options.forward_agent = 0; | |
322 | break; | |
323 | case 'A': | |
324 | options.forward_agent = 1; | |
325 | break; | |
326 | case 'k': | |
327 | options.gss_deleg_creds = 0; | |
328 | break; | |
329 | case 'K': | |
330 | options.gss_authentication = 1; | |
331 | options.gss_deleg_creds = 1; | |
332 | break; | |
333 | case 'i': | |
334 | if (stat(optarg, &st) < 0) { | |
335 | fprintf(stderr, "Warning: Identity file %s " | |
336 | "not accessible: %s.\n", optarg, | |
337 | strerror(errno)); | |
338 | break; | |
339 | } | |
340 | if (options.num_identity_files >= | |
341 | SSH_MAX_IDENTITY_FILES) | |
342 | fatal("Too many identity files specified " | |
343 | "(max %d)", SSH_MAX_IDENTITY_FILES); | |
344 | options.identity_files[options.num_identity_files++] = | |
345 | xstrdup(optarg); | |
346 | break; | |
347 | case 'I': | |
348 | #ifdef SMARTCARD | |
349 | options.smartcard_device = xstrdup(optarg); | |
350 | #else | |
351 | fprintf(stderr, "no support for smartcards.\n"); | |
352 | #endif | |
353 | break; | |
354 | case 't': | |
355 | if (tty_flag) | |
356 | force_tty_flag = 1; | |
357 | tty_flag = 1; | |
358 | break; | |
359 | case 'v': | |
360 | if (debug_flag == 0) { | |
361 | debug_flag = 1; | |
362 | options.log_level = SYSLOG_LEVEL_DEBUG1; | |
363 | } else { | |
364 | if (options.log_level < SYSLOG_LEVEL_DEBUG3) | |
365 | options.log_level++; | |
366 | break; | |
367 | } | |
368 | /* FALLTHROUGH */ | |
369 | case 'V': | |
370 | fprintf(stderr, "%s, %s\n", | |
371 | SSH_RELEASE, SSLeay_version(SSLEAY_VERSION)); | |
372 | if (opt == 'V') | |
373 | exit(0); | |
374 | break; | |
375 | case 'w': | |
376 | if (options.tun_open == -1) | |
377 | options.tun_open = SSH_TUNMODE_DEFAULT; | |
378 | options.tun_local = a2tun(optarg, &options.tun_remote); | |
379 | if (options.tun_local == SSH_TUNID_ERR) { | |
380 | fprintf(stderr, "Bad tun device '%s'\n", optarg); | |
381 | exit(255); | |
382 | } | |
383 | break; | |
384 | case 'q': | |
385 | options.log_level = SYSLOG_LEVEL_QUIET; | |
386 | break; | |
387 | case 'e': | |
388 | if (optarg[0] == '^' && optarg[2] == 0 && | |
389 | (u_char) optarg[1] >= 64 && | |
390 | (u_char) optarg[1] < 128) | |
391 | options.escape_char = (u_char) optarg[1] & 31; | |
392 | else if (strlen(optarg) == 1) | |
393 | options.escape_char = (u_char) optarg[0]; | |
394 | else if (strcmp(optarg, "none") == 0) | |
395 | options.escape_char = SSH_ESCAPECHAR_NONE; | |
396 | else { | |
397 | fprintf(stderr, "Bad escape character '%s'.\n", | |
398 | optarg); | |
399 | exit(255); | |
400 | } | |
401 | break; | |
402 | case 'c': | |
403 | if (ciphers_valid(optarg)) { | |
404 | /* SSH2 only */ | |
405 | options.ciphers = xstrdup(optarg); | |
406 | options.cipher = SSH_CIPHER_INVALID; | |
407 | } else { | |
408 | /* SSH1 only */ | |
409 | options.cipher = cipher_number(optarg); | |
410 | if (options.cipher == -1) { | |
411 | fprintf(stderr, | |
412 | "Unknown cipher type '%s'\n", | |
413 | optarg); | |
414 | exit(255); | |
415 | } | |
416 | if (options.cipher == SSH_CIPHER_3DES) | |
417 | options.ciphers = "3des-cbc"; | |
418 | else if (options.cipher == SSH_CIPHER_BLOWFISH) | |
419 | options.ciphers = "blowfish-cbc"; | |
420 | else | |
421 | options.ciphers = (char *)-1; | |
422 | } | |
423 | break; | |
424 | case 'm': | |
425 | if (mac_valid(optarg)) | |
426 | options.macs = xstrdup(optarg); | |
427 | else { | |
428 | fprintf(stderr, "Unknown mac type '%s'\n", | |
429 | optarg); | |
430 | exit(255); | |
431 | } | |
432 | break; | |
433 | case 'M': | |
434 | if (options.control_master == SSHCTL_MASTER_YES) | |
435 | options.control_master = SSHCTL_MASTER_ASK; | |
436 | else | |
437 | options.control_master = SSHCTL_MASTER_YES; | |
438 | break; | |
439 | case 'p': | |
440 | options.port = a2port(optarg); | |
441 | if (options.port == 0) { | |
442 | fprintf(stderr, "Bad port '%s'\n", optarg); | |
443 | exit(255); | |
444 | } | |
445 | break; | |
446 | case 'l': | |
447 | options.user = optarg; | |
448 | break; | |
449 | ||
450 | case 'L': | |
451 | if (parse_forward(&fwd, optarg)) | |
452 | add_local_forward(&options, &fwd); | |
453 | else { | |
454 | fprintf(stderr, | |
455 | "Bad local forwarding specification '%s'\n", | |
456 | optarg); | |
457 | exit(255); | |
458 | } | |
459 | break; | |
460 | ||
461 | case 'R': | |
462 | if (parse_forward(&fwd, optarg)) { | |
463 | add_remote_forward(&options, &fwd); | |
464 | } else { | |
465 | fprintf(stderr, | |
466 | "Bad remote forwarding specification " | |
467 | "'%s'\n", optarg); | |
468 | exit(255); | |
469 | } | |
470 | break; | |
471 | ||
472 | case 'D': | |
473 | cp = p = xstrdup(optarg); | |
474 | memset(&fwd, '\0', sizeof(fwd)); | |
475 | fwd.connect_host = "socks"; | |
476 | if ((fwd.listen_host = hpdelim(&cp)) == NULL) { | |
477 | fprintf(stderr, "Bad dynamic forwarding " | |
478 | "specification '%.100s'\n", optarg); | |
479 | exit(255); | |
480 | } | |
481 | if (cp != NULL) { | |
482 | fwd.listen_port = a2port(cp); | |
483 | fwd.listen_host = cleanhostname(fwd.listen_host); | |
484 | } else { | |
485 | fwd.listen_port = a2port(fwd.listen_host); | |
486 | fwd.listen_host = NULL; | |
487 | } | |
488 | ||
489 | if (fwd.listen_port == 0) { | |
490 | fprintf(stderr, "Bad dynamic port '%s'\n", | |
491 | optarg); | |
492 | exit(255); | |
493 | } | |
494 | add_local_forward(&options, &fwd); | |
495 | xfree(p); | |
496 | break; | |
497 | ||
498 | case 'C': | |
499 | options.compression = 1; | |
500 | break; | |
501 | case 'N': | |
502 | no_shell_flag = 1; | |
503 | no_tty_flag = 1; | |
504 | break; | |
505 | case 'T': | |
506 | no_tty_flag = 1; | |
507 | break; | |
508 | case 'o': | |
509 | dummy = 1; | |
510 | line = xstrdup(optarg); | |
511 | if (process_config_line(&options, host ? host : "", | |
512 | line, "command-line", 0, &dummy) != 0) | |
513 | exit(255); | |
514 | xfree(line); | |
515 | break; | |
516 | case 's': | |
517 | subsystem_flag = 1; | |
518 | break; | |
519 | case 'S': | |
520 | if (options.control_path != NULL) | |
521 | free(options.control_path); | |
522 | options.control_path = xstrdup(optarg); | |
523 | break; | |
524 | case 'b': | |
525 | options.bind_address = optarg; | |
526 | break; | |
527 | case 'F': | |
528 | config = optarg; | |
529 | break; | |
530 | default: | |
531 | usage(); | |
532 | } | |
533 | } | |
534 | ||
535 | ac -= optind; | |
536 | av += optind; | |
537 | ||
538 | if (ac > 0 && !host && **av != '-') { | |
539 | if (strrchr(*av, '@')) { | |
540 | p = xstrdup(*av); | |
541 | cp = strrchr(p, '@'); | |
542 | if (cp == NULL || cp == p) | |
543 | usage(); | |
544 | options.user = p; | |
545 | *cp = '\0'; | |
546 | host = ++cp; | |
547 | } else | |
548 | host = *av; | |
549 | if (ac > 1) { | |
550 | optind = optreset = 1; | |
551 | goto again; | |
552 | } | |
553 | ac--, av++; | |
554 | } | |
555 | ||
556 | /* Check that we got a host name. */ | |
557 | if (!host) | |
558 | usage(); | |
559 | ||
560 | SSLeay_add_all_algorithms(); | |
561 | ERR_load_crypto_strings(); | |
562 | ||
563 | /* Initialize the command to execute on remote host. */ | |
564 | buffer_init(&command); | |
565 | ||
566 | /* | |
567 | * Save the command to execute on the remote host in a buffer. There | |
568 | * is no limit on the length of the command, except by the maximum | |
569 | * packet size. Also sets the tty flag if there is no command. | |
570 | */ | |
571 | if (!ac) { | |
572 | /* No command specified - execute shell on a tty. */ | |
573 | tty_flag = 1; | |
574 | if (subsystem_flag) { | |
575 | fprintf(stderr, | |
576 | "You must specify a subsystem to invoke.\n"); | |
577 | usage(); | |
578 | } | |
579 | } else { | |
580 | /* A command has been specified. Store it into the buffer. */ | |
581 | for (i = 0; i < ac; i++) { | |
582 | if (i) | |
583 | buffer_append(&command, " ", 1); | |
584 | buffer_append(&command, av[i], strlen(av[i])); | |
585 | } | |
586 | } | |
587 | ||
588 | /* Cannot fork to background if no command. */ | |
589 | if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag) | |
590 | fatal("Cannot fork into background without a command to execute."); | |
591 | ||
592 | /* Allocate a tty by default if no command specified. */ | |
593 | if (buffer_len(&command) == 0) | |
594 | tty_flag = 1; | |
595 | ||
596 | /* Force no tty */ | |
597 | if (no_tty_flag) | |
598 | tty_flag = 0; | |
599 | /* Do not allocate a tty if stdin is not a tty. */ | |
600 | if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) { | |
601 | if (tty_flag) | |
602 | logit("Pseudo-terminal will not be allocated because stdin is not a terminal."); | |
603 | tty_flag = 0; | |
604 | } | |
605 | ||
606 | /* | |
607 | * Initialize "log" output. Since we are the client all output | |
608 | * actually goes to stderr. | |
609 | */ | |
610 | log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, | |
611 | SYSLOG_FACILITY_USER, 1); | |
612 | ||
613 | /* | |
614 | * Read per-user configuration file. Ignore the system wide config | |
615 | * file if the user specifies a config file on the command line. | |
616 | */ | |
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)); | |
621 | } else { | |
622 | snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, | |
623 | _PATH_SSH_USER_CONFFILE); | |
624 | (void)read_config_file(buf, host, &options, 1); | |
625 | ||
626 | /* Read systemwide configuration file after use config. */ | |
627 | (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, | |
628 | &options, 0); | |
629 | } | |
630 | ||
631 | /* Fill configuration defaults. */ | |
632 | fill_default_options(&options); | |
633 | ||
634 | channel_set_af(options.address_family); | |
635 | ||
636 | /* reinit */ | |
637 | log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1); | |
638 | ||
639 | seed_rng(); | |
640 | ||
641 | if (options.user == NULL) | |
642 | options.user = xstrdup(pw->pw_name); | |
643 | ||
644 | if (options.hostname != NULL) | |
645 | host = options.hostname; | |
646 | ||
647 | /* force lowercase for hostkey matching */ | |
648 | if (options.host_key_alias != NULL) { | |
649 | for (p = options.host_key_alias; *p; p++) | |
650 | if (isupper(*p)) | |
651 | *p = (char)tolower(*p); | |
652 | } | |
653 | ||
654 | /* Get default port if port has not been set. */ | |
655 | if (options.port == 0) { | |
656 | sp = getservbyname(SSH_SERVICE_NAME, "tcp"); | |
657 | options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT; | |
658 | } | |
659 | ||
660 | if (options.proxy_command != NULL && | |
661 | strcmp(options.proxy_command, "none") == 0) { | |
662 | xfree(options.proxy_command); | |
663 | options.proxy_command = NULL; | |
664 | } | |
665 | if (options.control_path != NULL && | |
666 | strcmp(options.control_path, "none") == 0) { | |
667 | xfree(options.control_path); | |
668 | options.control_path = NULL; | |
669 | } | |
670 | ||
671 | if (options.control_path != NULL) { | |
672 | char thishost[NI_MAXHOST]; | |
673 | ||
674 | if (gethostname(thishost, sizeof(thishost)) == -1) | |
675 | fatal("gethostname: %s", strerror(errno)); | |
676 | snprintf(buf, sizeof(buf), "%d", options.port); | |
677 | cp = tilde_expand_filename(options.control_path, | |
678 | original_real_uid); | |
679 | xfree(options.control_path); | |
680 | options.control_path = percent_expand(cp, "p", buf, "h", host, | |
681 | "r", options.user, "l", thishost, (char *)NULL); | |
682 | xfree(cp); | |
683 | } | |
684 | if (mux_command != 0 && options.control_path == NULL) | |
685 | fatal("No ControlPath specified for \"-O\" command"); | |
686 | if (options.control_path != NULL) | |
687 | control_client(options.control_path); | |
688 | ||
689 | timeout_ms = options.connection_timeout * 1000; | |
690 | ||
691 | /* Open a connection to the remote host. */ | |
692 | if (ssh_connect(host, &hostaddr, options.port, | |
693 | options.address_family, options.connection_attempts, &timeout_ms, | |
694 | options.tcp_keep_alive, | |
695 | #ifdef HAVE_CYGWIN | |
696 | options.use_privileged_port, | |
697 | #else | |
698 | original_effective_uid == 0 && options.use_privileged_port, | |
699 | #endif | |
700 | options.proxy_command) != 0) | |
701 | exit(255); | |
702 | ||
703 | if (timeout_ms > 0) | |
704 | debug3("timeout: %d ms remain after connect", timeout_ms); | |
705 | ||
706 | /* | |
707 | * If we successfully made the connection, load the host private key | |
708 | * in case we will need it later for combined rsa-rhosts | |
709 | * authentication. This must be done before releasing extra | |
710 | * privileges, because the file is only readable by root. | |
711 | * If we cannot access the private keys, load the public keys | |
712 | * instead and try to execute the ssh-keysign helper instead. | |
713 | */ | |
714 | sensitive_data.nkeys = 0; | |
715 | sensitive_data.keys = NULL; | |
716 | sensitive_data.external_keysign = 0; | |
717 | if (options.rhosts_rsa_authentication || | |
718 | options.hostbased_authentication) { | |
719 | sensitive_data.nkeys = 3; | |
720 | sensitive_data.keys = xcalloc(sensitive_data.nkeys, | |
721 | sizeof(Key)); | |
722 | ||
723 | PRIV_START; | |
724 | sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, | |
725 | _PATH_HOST_KEY_FILE, "", NULL, NULL); | |
726 | sensitive_data.keys[1] = key_load_private_type(KEY_DSA, | |
727 | _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); | |
728 | sensitive_data.keys[2] = key_load_private_type(KEY_RSA, | |
729 | _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); | |
730 | PRIV_END; | |
731 | ||
732 | if (options.hostbased_authentication == 1 && | |
733 | sensitive_data.keys[0] == NULL && | |
734 | sensitive_data.keys[1] == NULL && | |
735 | sensitive_data.keys[2] == NULL) { | |
736 | sensitive_data.keys[1] = key_load_public( | |
737 | _PATH_HOST_DSA_KEY_FILE, NULL); | |
738 | sensitive_data.keys[2] = key_load_public( | |
739 | _PATH_HOST_RSA_KEY_FILE, NULL); | |
740 | sensitive_data.external_keysign = 1; | |
741 | } | |
742 | } | |
743 | /* | |
744 | * Get rid of any extra privileges that we may have. We will no | |
745 | * longer need them. Also, extra privileges could make it very hard | |
746 | * to read identity files and other non-world-readable files from the | |
747 | * user's home directory if it happens to be on a NFS volume where | |
748 | * root is mapped to nobody. | |
749 | */ | |
750 | if (original_effective_uid == 0) { | |
751 | PRIV_START; | |
752 | permanently_set_uid(pw); | |
753 | } | |
754 | ||
755 | /* | |
756 | * Now that we are back to our own permissions, create ~/.ssh | |
757 | * directory if it doesn't already exist. | |
758 | */ | |
759 | snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); | |
760 | if (stat(buf, &st) < 0) | |
761 | if (mkdir(buf, 0700) < 0) | |
762 | error("Could not create directory '%.200s'.", buf); | |
763 | ||
764 | /* load options.identity_files */ | |
765 | load_public_identity_files(); | |
766 | ||
767 | /* Expand ~ in known host file names. */ | |
768 | /* XXX mem-leaks: */ | |
769 | options.system_hostfile = | |
770 | tilde_expand_filename(options.system_hostfile, original_real_uid); | |
771 | options.user_hostfile = | |
772 | tilde_expand_filename(options.user_hostfile, original_real_uid); | |
773 | options.system_hostfile2 = | |
774 | tilde_expand_filename(options.system_hostfile2, original_real_uid); | |
775 | options.user_hostfile2 = | |
776 | tilde_expand_filename(options.user_hostfile2, original_real_uid); | |
777 | ||
778 | signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ | |
779 | ||
780 | /* Log into the remote system. This never returns if the login fails. */ | |
781 | ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, | |
782 | pw, timeout_ms); | |
783 | ||
784 | /* We no longer need the private host keys. Clear them now. */ | |
785 | if (sensitive_data.nkeys != 0) { | |
786 | for (i = 0; i < sensitive_data.nkeys; i++) { | |
787 | if (sensitive_data.keys[i] != NULL) { | |
788 | /* Destroys contents safely */ | |
789 | debug3("clear hostkey %d", i); | |
790 | key_free(sensitive_data.keys[i]); | |
791 | sensitive_data.keys[i] = NULL; | |
792 | } | |
793 | } | |
794 | xfree(sensitive_data.keys); | |
795 | } | |
796 | for (i = 0; i < options.num_identity_files; i++) { | |
797 | if (options.identity_files[i]) { | |
798 | xfree(options.identity_files[i]); | |
799 | options.identity_files[i] = NULL; | |
800 | } | |
801 | if (options.identity_keys[i]) { | |
802 | key_free(options.identity_keys[i]); | |
803 | options.identity_keys[i] = NULL; | |
804 | } | |
805 | } | |
806 | ||
807 | exit_status = compat20 ? ssh_session2() : ssh_session(); | |
808 | packet_close(); | |
809 | ||
810 | if (options.control_path != NULL && control_fd != -1) | |
811 | unlink(options.control_path); | |
812 | ||
813 | /* | |
814 | * Send SIGHUP to proxy command if used. We don't wait() in | |
815 | * case it hangs and instead rely on init to reap the child | |
816 | */ | |
817 | if (proxy_command_pid > 1) | |
818 | kill(proxy_command_pid, SIGHUP); | |
819 | ||
820 | return exit_status; | |
821 | } | |
822 | ||
823 | static void | |
824 | ssh_init_forwarding(void) | |
825 | { | |
826 | int success = 0; | |
827 | int i; | |
828 | ||
829 | /* Initiate local TCP/IP port forwardings. */ | |
830 | for (i = 0; i < options.num_local_forwards; i++) { | |
831 | debug("Local connections to %.200s:%d forwarded to remote " | |
832 | "address %.200s:%d", | |
833 | (options.local_forwards[i].listen_host == NULL) ? | |
834 | (options.gateway_ports ? "*" : "LOCALHOST") : | |
835 | options.local_forwards[i].listen_host, | |
836 | options.local_forwards[i].listen_port, | |
837 | options.local_forwards[i].connect_host, | |
838 | options.local_forwards[i].connect_port); | |
839 | success += channel_setup_local_fwd_listener( | |
840 | options.local_forwards[i].listen_host, | |
841 | options.local_forwards[i].listen_port, | |
842 | options.local_forwards[i].connect_host, | |
843 | options.local_forwards[i].connect_port, | |
844 | options.gateway_ports); | |
845 | } | |
846 | if (i > 0 && success != i && options.exit_on_forward_failure) | |
847 | fatal("Could not request local forwarding."); | |
848 | if (i > 0 && success == 0) | |
849 | error("Could not request local forwarding."); | |
850 | ||
851 | /* Initiate remote TCP/IP port forwardings. */ | |
852 | for (i = 0; i < options.num_remote_forwards; i++) { | |
853 | debug("Remote connections from %.200s:%d forwarded to " | |
854 | "local address %.200s:%d", | |
855 | (options.remote_forwards[i].listen_host == NULL) ? | |
856 | "LOCALHOST" : options.remote_forwards[i].listen_host, | |
857 | options.remote_forwards[i].listen_port, | |
858 | options.remote_forwards[i].connect_host, | |
859 | options.remote_forwards[i].connect_port); | |
860 | if (channel_request_remote_forwarding( | |
861 | options.remote_forwards[i].listen_host, | |
862 | options.remote_forwards[i].listen_port, | |
863 | options.remote_forwards[i].connect_host, | |
864 | options.remote_forwards[i].connect_port) < 0) { | |
865 | if (options.exit_on_forward_failure) | |
866 | fatal("Could not request remote forwarding."); | |
867 | else | |
868 | logit("Warning: Could not request remote " | |
869 | "forwarding."); | |
870 | } | |
871 | } | |
872 | ||
873 | /* Initiate tunnel forwarding. */ | |
874 | if (options.tun_open != SSH_TUNMODE_NO) { | |
875 | if (client_request_tun_fwd(options.tun_open, | |
876 | options.tun_local, options.tun_remote) == -1) { | |
877 | if (options.exit_on_forward_failure) | |
878 | fatal("Could not request tunnel forwarding."); | |
879 | else | |
880 | error("Could not request tunnel forwarding."); | |
881 | } | |
882 | } | |
883 | } | |
884 | ||
885 | static void | |
886 | check_agent_present(void) | |
887 | { | |
888 | if (options.forward_agent) { | |
889 | /* Clear agent forwarding if we don't have an agent. */ | |
890 | if (!ssh_agent_present()) | |
891 | options.forward_agent = 0; | |
892 | } | |
893 | } | |
894 | ||
895 | static int | |
896 | ssh_session(void) | |
897 | { | |
898 | int type; | |
899 | int interactive = 0; | |
900 | int have_tty = 0; | |
901 | struct winsize ws; | |
902 | char *cp; | |
903 | const char *display; | |
904 | ||
905 | /* Enable compression if requested. */ | |
906 | if (options.compression) { | |
907 | debug("Requesting compression at level %d.", options.compression_level); | |
908 | ||
909 | if (options.compression_level < 1 || options.compression_level > 9) | |
910 | fatal("Compression level must be from 1 (fast) to 9 (slow, best)."); | |
911 | ||
912 | /* Send the request. */ | |
913 | packet_start(SSH_CMSG_REQUEST_COMPRESSION); | |
914 | packet_put_int(options.compression_level); | |
915 | packet_send(); | |
916 | packet_write_wait(); | |
917 | type = packet_read(); | |
918 | if (type == SSH_SMSG_SUCCESS) | |
919 | packet_start_compression(options.compression_level); | |
920 | else if (type == SSH_SMSG_FAILURE) | |
921 | logit("Warning: Remote host refused compression."); | |
922 | else | |
923 | packet_disconnect("Protocol error waiting for compression response."); | |
924 | } | |
925 | /* Allocate a pseudo tty if appropriate. */ | |
926 | if (tty_flag) { | |
927 | debug("Requesting pty."); | |
928 | ||
929 | /* Start the packet. */ | |
930 | packet_start(SSH_CMSG_REQUEST_PTY); | |
931 | ||
932 | /* Store TERM in the packet. There is no limit on the | |
933 | length of the string. */ | |
934 | cp = getenv("TERM"); | |
935 | if (!cp) | |
936 | cp = ""; | |
937 | packet_put_cstring(cp); | |
938 | ||
939 | /* Store window size in the packet. */ | |
940 | if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) | |
941 | memset(&ws, 0, sizeof(ws)); | |
942 | packet_put_int((u_int)ws.ws_row); | |
943 | packet_put_int((u_int)ws.ws_col); | |
944 | packet_put_int((u_int)ws.ws_xpixel); | |
945 | packet_put_int((u_int)ws.ws_ypixel); | |
946 | ||
947 | /* Store tty modes in the packet. */ | |
948 | tty_make_modes(fileno(stdin), NULL); | |
949 | ||
950 | /* Send the packet, and wait for it to leave. */ | |
951 | packet_send(); | |
952 | packet_write_wait(); | |
953 | ||
954 | /* Read response from the server. */ | |
955 | type = packet_read(); | |
956 | if (type == SSH_SMSG_SUCCESS) { | |
957 | interactive = 1; | |
958 | have_tty = 1; | |
959 | } else if (type == SSH_SMSG_FAILURE) | |
960 | logit("Warning: Remote host failed or refused to allocate a pseudo tty."); | |
961 | else | |
962 | packet_disconnect("Protocol error waiting for pty request response."); | |
963 | } | |
964 | /* Request X11 forwarding if enabled and DISPLAY is set. */ | |
965 | display = getenv("DISPLAY"); | |
966 | if (options.forward_x11 && display != NULL) { | |
967 | char *proto, *data; | |
968 | /* Get reasonable local authentication information. */ | |
969 | client_x11_get_proto(display, options.xauth_location, | |
970 | options.forward_x11_trusted, &proto, &data); | |
971 | /* Request forwarding with authentication spoofing. */ | |
972 | debug("Requesting X11 forwarding with authentication spoofing."); | |
973 | x11_request_forwarding_with_spoofing(0, display, proto, data); | |
974 | ||
975 | /* Read response from the server. */ | |
976 | type = packet_read(); | |
977 | if (type == SSH_SMSG_SUCCESS) { | |
978 | interactive = 1; | |
979 | } else if (type == SSH_SMSG_FAILURE) { | |
980 | logit("Warning: Remote host denied X11 forwarding."); | |
981 | } else { | |
982 | packet_disconnect("Protocol error waiting for X11 forwarding"); | |
983 | } | |
984 | } | |
985 | /* Tell the packet module whether this is an interactive session. */ | |
986 | packet_set_interactive(interactive); | |
987 | ||
988 | /* Request authentication agent forwarding if appropriate. */ | |
989 | check_agent_present(); | |
990 | ||
991 | if (options.forward_agent) { | |
992 | debug("Requesting authentication agent forwarding."); | |
993 | auth_request_forwarding(); | |
994 | ||
995 | /* Read response from the server. */ | |
996 | type = packet_read(); | |
997 | packet_check_eom(); | |
998 | if (type != SSH_SMSG_SUCCESS) | |
999 | logit("Warning: Remote host denied authentication agent forwarding."); | |
1000 | } | |
1001 | ||
1002 | /* Initiate port forwardings. */ | |
1003 | ssh_init_forwarding(); | |
1004 | ||
1005 | /* Execute a local command */ | |
1006 | if (options.local_command != NULL && | |
1007 | options.permit_local_command) | |
1008 | ssh_local_cmd(options.local_command); | |
1009 | ||
1010 | /* If requested, let ssh continue in the background. */ | |
1011 | if (fork_after_authentication_flag) | |
1012 | if (daemon(1, 1) < 0) | |
1013 | fatal("daemon() failed: %.200s", strerror(errno)); | |
1014 | ||
1015 | /* | |
1016 | * If a command was specified on the command line, execute the | |
1017 | * command now. Otherwise request the server to start a shell. | |
1018 | */ | |
1019 | if (buffer_len(&command) > 0) { | |
1020 | int len = buffer_len(&command); | |
1021 | if (len > 900) | |
1022 | len = 900; | |
1023 | debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command)); | |
1024 | packet_start(SSH_CMSG_EXEC_CMD); | |
1025 | packet_put_string(buffer_ptr(&command), buffer_len(&command)); | |
1026 | packet_send(); | |
1027 | packet_write_wait(); | |
1028 | } else { | |
1029 | debug("Requesting shell."); | |
1030 | packet_start(SSH_CMSG_EXEC_SHELL); | |
1031 | packet_send(); | |
1032 | packet_write_wait(); | |
1033 | } | |
1034 | ||
1035 | /* Enter the interactive session. */ | |
1036 | return client_loop(have_tty, tty_flag ? | |
1037 | options.escape_char : SSH_ESCAPECHAR_NONE, 0); | |
1038 | } | |
1039 | ||
1040 | static void | |
1041 | ssh_subsystem_reply(int type, u_int32_t seq, void *ctxt) | |
1042 | { | |
1043 | int id, len; | |
1044 | ||
1045 | id = packet_get_int(); | |
1046 | len = buffer_len(&command); | |
1047 | if (len > 900) | |
1048 | len = 900; | |
1049 | packet_check_eom(); | |
1050 | if (type == SSH2_MSG_CHANNEL_FAILURE) | |
1051 | fatal("Request for subsystem '%.*s' failed on channel %d", | |
1052 | len, (u_char *)buffer_ptr(&command), id); | |
1053 | } | |
1054 | ||
1055 | void | |
1056 | client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt) | |
1057 | { | |
1058 | int i; | |
1059 | ||
1060 | i = client_global_request_id++; | |
1061 | if (i >= options.num_remote_forwards) | |
1062 | return; | |
1063 | debug("remote forward %s for: listen %d, connect %s:%d", | |
1064 | type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", | |
1065 | options.remote_forwards[i].listen_port, | |
1066 | options.remote_forwards[i].connect_host, | |
1067 | options.remote_forwards[i].connect_port); | |
1068 | if (type == SSH2_MSG_REQUEST_FAILURE) { | |
1069 | if (options.exit_on_forward_failure) | |
1070 | fatal("Error: remote port forwarding failed for " | |
1071 | "listen port %d", | |
1072 | options.remote_forwards[i].listen_port); | |
1073 | else | |
1074 | logit("Warning: remote port forwarding failed for " | |
1075 | "listen port %d", | |
1076 | options.remote_forwards[i].listen_port); | |
1077 | } | |
1078 | } | |
1079 | ||
1080 | static void | |
1081 | ssh_control_listener(void) | |
1082 | { | |
1083 | struct sockaddr_un addr; | |
1084 | mode_t old_umask; | |
1085 | int addr_len; | |
1086 | ||
1087 | if (options.control_path == NULL || | |
1088 | options.control_master == SSHCTL_MASTER_NO) | |
1089 | return; | |
1090 | ||
1091 | debug("setting up multiplex master socket"); | |
1092 | ||
1093 | memset(&addr, '\0', sizeof(addr)); | |
1094 | addr.sun_family = AF_UNIX; | |
1095 | addr_len = offsetof(struct sockaddr_un, sun_path) + | |
1096 | strlen(options.control_path) + 1; | |
1097 | ||
1098 | if (strlcpy(addr.sun_path, options.control_path, | |
1099 | sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) | |
1100 | fatal("ControlPath too long"); | |
1101 | ||
1102 | if ((control_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) | |
1103 | fatal("%s socket(): %s", __func__, strerror(errno)); | |
1104 | ||
1105 | old_umask = umask(0177); | |
1106 | if (bind(control_fd, (struct sockaddr *)&addr, addr_len) == -1) { | |
1107 | control_fd = -1; | |
1108 | if (errno == EINVAL || errno == EADDRINUSE) | |
1109 | fatal("ControlSocket %s already exists", | |
1110 | options.control_path); | |
1111 | else | |
1112 | fatal("%s bind(): %s", __func__, strerror(errno)); | |
1113 | } | |
1114 | umask(old_umask); | |
1115 | ||
1116 | if (listen(control_fd, 64) == -1) | |
1117 | fatal("%s listen(): %s", __func__, strerror(errno)); | |
1118 | ||
1119 | set_nonblock(control_fd); | |
1120 | } | |
1121 | ||
1122 | /* request pty/x11/agent/tcpfwd/shell for channel */ | |
1123 | static void | |
1124 | ssh_session2_setup(int id, void *arg) | |
1125 | { | |
1126 | extern char **environ; | |
1127 | const char *display; | |
1128 | int interactive = tty_flag; | |
1129 | ||
1130 | display = getenv("DISPLAY"); | |
1131 | if (options.forward_x11 && display != NULL) { | |
1132 | char *proto, *data; | |
1133 | /* Get reasonable local authentication information. */ | |
1134 | client_x11_get_proto(display, options.xauth_location, | |
1135 | options.forward_x11_trusted, &proto, &data); | |
1136 | /* Request forwarding with authentication spoofing. */ | |
1137 | debug("Requesting X11 forwarding with authentication spoofing."); | |
1138 | x11_request_forwarding_with_spoofing(id, display, proto, data); | |
1139 | interactive = 1; | |
1140 | /* XXX wait for reply */ | |
1141 | } | |
1142 | ||
1143 | check_agent_present(); | |
1144 | if (options.forward_agent) { | |
1145 | debug("Requesting authentication agent forwarding."); | |
1146 | channel_request_start(id, "auth-agent-req@openssh.com", 0); | |
1147 | packet_send(); | |
1148 | } | |
1149 | ||
1150 | client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), | |
1151 | NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply); | |
1152 | ||
1153 | packet_set_interactive(interactive); | |
1154 | } | |
1155 | ||
1156 | /* open new channel for a session */ | |
1157 | static int | |
1158 | ssh_session2_open(void) | |
1159 | { | |
1160 | Channel *c; | |
1161 | int window, packetmax, in, out, err; | |
1162 | ||
1163 | if (stdin_null_flag) { | |
1164 | in = open(_PATH_DEVNULL, O_RDONLY); | |
1165 | } else { | |
1166 | in = dup(STDIN_FILENO); | |
1167 | } | |
1168 | out = dup(STDOUT_FILENO); | |
1169 | err = dup(STDERR_FILENO); | |
1170 | ||
1171 | if (in < 0 || out < 0 || err < 0) | |
1172 | fatal("dup() in/out/err failed"); | |
1173 | ||
1174 | /* enable nonblocking unless tty */ | |
1175 | if (!isatty(in)) | |
1176 | set_nonblock(in); | |
1177 | if (!isatty(out)) | |
1178 | set_nonblock(out); | |
1179 | if (!isatty(err)) | |
1180 | set_nonblock(err); | |
1181 | ||
1182 | window = CHAN_SES_WINDOW_DEFAULT; | |
1183 | packetmax = CHAN_SES_PACKET_DEFAULT; | |
1184 | if (tty_flag) { | |
1185 | window >>= 1; | |
1186 | packetmax >>= 1; | |
1187 | } | |
1188 | c = channel_new( | |
1189 | "session", SSH_CHANNEL_OPENING, in, out, err, | |
1190 | window, packetmax, CHAN_EXTENDED_WRITE, | |
1191 | "client-session", /*nonblock*/0); | |
1192 | ||
1193 | debug3("ssh_session2_open: channel_new: %d", c->self); | |
1194 | ||
1195 | channel_send_open(c->self); | |
1196 | if (!no_shell_flag) | |
1197 | channel_register_confirm(c->self, ssh_session2_setup, NULL); | |
1198 | ||
1199 | return c->self; | |
1200 | } | |
1201 | ||
1202 | static int | |
1203 | ssh_session2(void) | |
1204 | { | |
1205 | int id = -1; | |
1206 | ||
1207 | /* XXX should be pre-session */ | |
1208 | ssh_init_forwarding(); | |
1209 | ||
1210 | if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) | |
1211 | id = ssh_session2_open(); | |
1212 | ||
1213 | /* Execute a local command */ | |
1214 | if (options.local_command != NULL && | |
1215 | options.permit_local_command) | |
1216 | ssh_local_cmd(options.local_command); | |
1217 | ||
1218 | /* Start listening for multiplex clients */ | |
1219 | ssh_control_listener(); | |
1220 | ||
1221 | /* If requested, let ssh continue in the background. */ | |
1222 | if (fork_after_authentication_flag) | |
1223 | if (daemon(1, 1) < 0) | |
1224 | fatal("daemon() failed: %.200s", strerror(errno)); | |
1225 | ||
1226 | return client_loop(tty_flag, tty_flag ? | |
1227 | options.escape_char : SSH_ESCAPECHAR_NONE, id); | |
1228 | } | |
1229 | ||
1230 | static void | |
1231 | load_public_identity_files(void) | |
1232 | { | |
1233 | char *filename, *cp, thishost[NI_MAXHOST]; | |
1234 | int i = 0; | |
1235 | Key *public; | |
1236 | struct passwd *pw; | |
1237 | #ifdef SMARTCARD | |
1238 | Key **keys; | |
1239 | ||
1240 | if (options.smartcard_device != NULL && | |
1241 | options.num_identity_files < SSH_MAX_IDENTITY_FILES && | |
1242 | (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL) { | |
1243 | int count = 0; | |
1244 | for (i = 0; keys[i] != NULL; i++) { | |
1245 | count++; | |
1246 | memmove(&options.identity_files[1], &options.identity_files[0], | |
1247 | sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1)); | |
1248 | memmove(&options.identity_keys[1], &options.identity_keys[0], | |
1249 | sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1)); | |
1250 | options.num_identity_files++; | |
1251 | options.identity_keys[0] = keys[i]; | |
1252 | options.identity_files[0] = sc_get_key_label(keys[i]); | |
1253 | } | |
1254 | if (options.num_identity_files > SSH_MAX_IDENTITY_FILES) | |
1255 | options.num_identity_files = SSH_MAX_IDENTITY_FILES; | |
1256 | i = count; | |
1257 | xfree(keys); | |
1258 | } | |
1259 | #endif /* SMARTCARD */ | |
1260 | if ((pw = getpwuid(original_real_uid)) == NULL) | |
1261 | fatal("load_public_identity_files: getpwuid failed"); | |
1262 | if (gethostname(thishost, sizeof(thishost)) == -1) | |
1263 | fatal("load_public_identity_files: gethostname: %s", | |
1264 | strerror(errno)); | |
1265 | for (; i < options.num_identity_files; i++) { | |
1266 | cp = tilde_expand_filename(options.identity_files[i], | |
1267 | original_real_uid); | |
1268 | filename = percent_expand(cp, "d", pw->pw_dir, | |
1269 | "u", pw->pw_name, "l", thishost, "h", host, | |
1270 | "r", options.user, (char *)NULL); | |
1271 | xfree(cp); | |
1272 | public = key_load_public(filename, NULL); | |
1273 | debug("identity file %s type %d", filename, | |
1274 | public ? public->type : -1); | |
1275 | xfree(options.identity_files[i]); | |
1276 | options.identity_files[i] = filename; | |
1277 | options.identity_keys[i] = public; | |
1278 | } | |
1279 | } | |
1280 | ||
1281 | static void | |
1282 | control_client_sighandler(int signo) | |
1283 | { | |
1284 | control_client_terminate = signo; | |
1285 | } | |
1286 | ||
1287 | static void | |
1288 | control_client_sigrelay(int signo) | |
1289 | { | |
1290 | if (control_server_pid > 1) | |
1291 | kill(control_server_pid, signo); | |
1292 | } | |
1293 | ||
1294 | static int | |
1295 | env_permitted(char *env) | |
1296 | { | |
1297 | int i, ret; | |
1298 | char name[1024], *cp; | |
1299 | ||
1300 | if ((cp = strchr(env, '=')) == NULL || cp == env) | |
1301 | return (0); | |
1302 | ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env); | |
1303 | if (ret <= 0 || (size_t)ret >= sizeof(name)) | |
1304 | fatal("env_permitted: name '%.100s...' too long", env); | |
1305 | ||
1306 | for (i = 0; i < options.num_send_env; i++) | |
1307 | if (match_pattern(name, options.send_env[i])) | |
1308 | return (1); | |
1309 | ||
1310 | return (0); | |
1311 | } | |
1312 | ||
1313 | static void | |
1314 | control_client(const char *path) | |
1315 | { | |
1316 | struct sockaddr_un addr; | |
1317 | int i, r, fd, sock, exitval[2], num_env, addr_len; | |
1318 | Buffer m; | |
1319 | char *term; | |
1320 | extern char **environ; | |
1321 | u_int flags; | |
1322 | ||
1323 | if (mux_command == 0) | |
1324 | mux_command = SSHMUX_COMMAND_OPEN; | |
1325 | ||
1326 | switch (options.control_master) { | |
1327 | case SSHCTL_MASTER_AUTO: | |
1328 | case SSHCTL_MASTER_AUTO_ASK: | |
1329 | debug("auto-mux: Trying existing master"); | |
1330 | /* FALLTHROUGH */ | |
1331 | case SSHCTL_MASTER_NO: | |
1332 | break; | |
1333 | default: | |
1334 | return; | |
1335 | } | |
1336 | ||
1337 | memset(&addr, '\0', sizeof(addr)); | |
1338 | addr.sun_family = AF_UNIX; | |
1339 | addr_len = offsetof(struct sockaddr_un, sun_path) + | |
1340 | strlen(path) + 1; | |
1341 | ||
1342 | if (strlcpy(addr.sun_path, path, | |
1343 | sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) | |
1344 | fatal("ControlPath too long"); | |
1345 | ||
1346 | if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) | |
1347 | fatal("%s socket(): %s", __func__, strerror(errno)); | |
1348 | ||
1349 | if (connect(sock, (struct sockaddr *)&addr, addr_len) == -1) { | |
1350 | if (mux_command != SSHMUX_COMMAND_OPEN) { | |
1351 | fatal("Control socket connect(%.100s): %s", path, | |
1352 | strerror(errno)); | |
1353 | } | |
1354 | if (errno == ENOENT) | |
1355 | debug("Control socket \"%.100s\" does not exist", path); | |
1356 | else { | |
1357 | error("Control socket connect(%.100s): %s", path, | |
1358 | strerror(errno)); | |
1359 | } | |
1360 | close(sock); | |
1361 | return; | |
1362 | } | |
1363 | ||
1364 | if (stdin_null_flag) { | |
1365 | if ((fd = open(_PATH_DEVNULL, O_RDONLY)) == -1) | |
1366 | fatal("open(/dev/null): %s", strerror(errno)); | |
1367 | if (dup2(fd, STDIN_FILENO) == -1) | |
1368 | fatal("dup2: %s", strerror(errno)); | |
1369 | if (fd > STDERR_FILENO) | |
1370 | close(fd); | |
1371 | } | |
1372 | ||
1373 | term = getenv("TERM"); | |
1374 | ||
1375 | flags = 0; | |
1376 | if (tty_flag) | |
1377 | flags |= SSHMUX_FLAG_TTY; | |
1378 | if (subsystem_flag) | |
1379 | flags |= SSHMUX_FLAG_SUBSYS; | |
1380 | if (options.forward_x11) | |
1381 | flags |= SSHMUX_FLAG_X11_FWD; | |
1382 | if (options.forward_agent) | |
1383 | flags |= SSHMUX_FLAG_AGENT_FWD; | |
1384 | ||
1385 | buffer_init(&m); | |
1386 | ||
1387 | /* Send our command to server */ | |
1388 | buffer_put_int(&m, mux_command); | |
1389 | buffer_put_int(&m, flags); | |
1390 | if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) | |
1391 | fatal("%s: msg_send", __func__); | |
1392 | buffer_clear(&m); | |
1393 | ||
1394 | /* Get authorisation status and PID of controlee */ | |
1395 | if (ssh_msg_recv(sock, &m) == -1) | |
1396 | fatal("%s: msg_recv", __func__); | |
1397 | if (buffer_get_char(&m) != SSHMUX_VER) | |
1398 | fatal("%s: wrong version", __func__); | |
1399 | if (buffer_get_int(&m) != 1) | |
1400 | fatal("Connection to master denied"); | |
1401 | control_server_pid = buffer_get_int(&m); | |
1402 | ||
1403 | buffer_clear(&m); | |
1404 | ||
1405 | switch (mux_command) { | |
1406 | case SSHMUX_COMMAND_ALIVE_CHECK: | |
1407 | fprintf(stderr, "Master running (pid=%d)\r\n", | |
1408 | control_server_pid); | |
1409 | exit(0); | |
1410 | case SSHMUX_COMMAND_TERMINATE: | |
1411 | fprintf(stderr, "Exit request sent.\r\n"); | |
1412 | exit(0); | |
1413 | case SSHMUX_COMMAND_OPEN: | |
1414 | /* continue below */ | |
1415 | break; | |
1416 | default: | |
1417 | fatal("silly mux_command %d", mux_command); | |
1418 | } | |
1419 | ||
1420 | /* SSHMUX_COMMAND_OPEN */ | |
1421 | buffer_put_cstring(&m, term ? term : ""); | |
1422 | buffer_append(&command, "\0", 1); | |
1423 | buffer_put_cstring(&m, buffer_ptr(&command)); | |
1424 | ||
1425 | if (options.num_send_env == 0 || environ == NULL) { | |
1426 | buffer_put_int(&m, 0); | |
1427 | } else { | |
1428 | /* Pass environment */ | |
1429 | num_env = 0; | |
1430 | for (i = 0; environ[i] != NULL; i++) | |
1431 | if (env_permitted(environ[i])) | |
1432 | num_env++; /* Count */ | |
1433 | ||
1434 | buffer_put_int(&m, num_env); | |
1435 | ||
1436 | for (i = 0; environ[i] != NULL && num_env >= 0; i++) | |
1437 | if (env_permitted(environ[i])) { | |
1438 | num_env--; | |
1439 | buffer_put_cstring(&m, environ[i]); | |
1440 | } | |
1441 | } | |
1442 | ||
1443 | if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) | |
1444 | fatal("%s: msg_send", __func__); | |
1445 | ||
1446 | if (mm_send_fd(sock, STDIN_FILENO) == -1 || | |
1447 | mm_send_fd(sock, STDOUT_FILENO) == -1 || | |
1448 | mm_send_fd(sock, STDERR_FILENO) == -1) | |
1449 | fatal("%s: send fds failed", __func__); | |
1450 | ||
1451 | /* Wait for reply, so master has a chance to gather ttymodes */ | |
1452 | buffer_clear(&m); | |
1453 | if (ssh_msg_recv(sock, &m) == -1) | |
1454 | fatal("%s: msg_recv", __func__); | |
1455 | if (buffer_get_char(&m) != SSHMUX_VER) | |
1456 | fatal("%s: wrong version", __func__); | |
1457 | buffer_free(&m); | |
1458 | ||
1459 | signal(SIGHUP, control_client_sighandler); | |
1460 | signal(SIGINT, control_client_sighandler); | |
1461 | signal(SIGTERM, control_client_sighandler); | |
1462 | signal(SIGWINCH, control_client_sigrelay); | |
1463 | ||
1464 | if (tty_flag) | |
1465 | enter_raw_mode(); | |
1466 | ||
1467 | /* | |
1468 | * Stick around until the controlee closes the client_fd. | |
1469 | * Before it does, it is expected to write this process' exit | |
1470 | * value (one int). This process must read the value and wait for | |
1471 | * the closure of the client_fd; if this one closes early, the | |
1472 | * multiplex master will terminate early too (possibly losing data). | |
1473 | */ | |
1474 | exitval[0] = 0; | |
1475 | for (i = 0; !control_client_terminate && i < (int)sizeof(exitval);) { | |
1476 | r = read(sock, (char *)exitval + i, sizeof(exitval) - i); | |
1477 | if (r == 0) { | |
1478 | debug2("Received EOF from master"); | |
1479 | break; | |
1480 | } | |
1481 | if (r == -1) { | |
1482 | if (errno == EINTR) | |
1483 | continue; | |
1484 | fatal("%s: read %s", __func__, strerror(errno)); | |
1485 | } | |
1486 | i += r; | |
1487 | } | |
1488 | ||
1489 | close(sock); | |
1490 | leave_raw_mode(); | |
1491 | if (i > (int)sizeof(int)) | |
1492 | fatal("%s: master returned too much data (%d > %lu)", | |
1493 | __func__, i, sizeof(int)); | |
1494 | if (control_client_terminate) { | |
1495 | debug2("Exiting on signal %d", control_client_terminate); | |
1496 | exitval[0] = 255; | |
1497 | } else if (i < (int)sizeof(int)) { | |
1498 | debug2("Control master terminated unexpectedly"); | |
1499 | exitval[0] = 255; | |
1500 | } else | |
1501 | debug2("Received exit status from master %d", exitval[0]); | |
1502 | ||
1503 | if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET) | |
1504 | fprintf(stderr, "Shared connection to %s closed.\r\n", host); | |
1505 | ||
1506 | exit(exitval[0]); | |
1507 | } |