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1 | /* | |
2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> | |
3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
4 | * All rights reserved | |
5 | * Ssh client program. This program can be used to log into a remote machine. | |
6 | * The software supports strong authentication, encryption, and forwarding | |
7 | * of X11, TCP/IP, and authentication connections. | |
8 | * | |
9 | * As far as I am concerned, the code I have written for this software | |
10 | * can be used freely for any purpose. Any derived versions of this | |
11 | * software must be clearly marked as such, and if the derived work is | |
12 | * incompatible with the protocol description in the RFC file, it must be | |
13 | * called by a name other than "ssh" or "Secure Shell". | |
14 | * | |
15 | * Copyright (c) 1999 Niels Provos. All rights reserved. | |
16 | * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved. | |
17 | * | |
18 | * Modified to work with SSL by Niels Provos <provos@citi.umich.edu> | |
19 | * in Canada (German citizen). | |
20 | * | |
21 | * Redistribution and use in source and binary forms, with or without | |
22 | * modification, are permitted provided that the following conditions | |
23 | * are met: | |
24 | * 1. Redistributions of source code must retain the above copyright | |
25 | * notice, this list of conditions and the following disclaimer. | |
26 | * 2. Redistributions in binary form must reproduce the above copyright | |
27 | * notice, this list of conditions and the following disclaimer in the | |
28 | * documentation and/or other materials provided with the distribution. | |
29 | * | |
30 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
31 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
32 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
33 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
34 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
35 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
36 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
37 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
38 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
39 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
40 | */ | |
41 | ||
42 | #include "includes.h" | |
43 | RCSID("$OpenBSD: ssh.c,v 1.258 2006/02/08 12:15:27 stevesk Exp $"); | |
44 | ||
45 | #include <paths.h> | |
46 | ||
47 | #include <openssl/evp.h> | |
48 | #include <openssl/err.h> | |
49 | ||
50 | #include "ssh.h" | |
51 | #include "ssh1.h" | |
52 | #include "ssh2.h" | |
53 | #include "compat.h" | |
54 | #include "cipher.h" | |
55 | #include "xmalloc.h" | |
56 | #include "packet.h" | |
57 | #include "buffer.h" | |
58 | #include "bufaux.h" | |
59 | #include "channels.h" | |
60 | #include "key.h" | |
61 | #include "authfd.h" | |
62 | #include "authfile.h" | |
63 | #include "pathnames.h" | |
64 | #include "dispatch.h" | |
65 | #include "clientloop.h" | |
66 | #include "log.h" | |
67 | #include "readconf.h" | |
68 | #include "sshconnect.h" | |
69 | #include "misc.h" | |
70 | #include "kex.h" | |
71 | #include "mac.h" | |
72 | #include "sshpty.h" | |
73 | #include "match.h" | |
74 | #include "msg.h" | |
75 | #include "monitor_fdpass.h" | |
76 | #include "uidswap.h" | |
77 | ||
78 | #ifdef SMARTCARD | |
79 | #include "scard.h" | |
80 | #endif | |
81 | ||
82 | extern char *__progname; | |
83 | ||
84 | /* Flag indicating whether debug mode is on. This can be set on the command line. */ | |
85 | int debug_flag = 0; | |
86 | ||
87 | /* Flag indicating whether a tty should be allocated */ | |
88 | int tty_flag = 0; | |
89 | int no_tty_flag = 0; | |
90 | int force_tty_flag = 0; | |
91 | ||
92 | /* don't exec a shell */ | |
93 | int no_shell_flag = 0; | |
94 | ||
95 | /* | |
96 | * Flag indicating that nothing should be read from stdin. This can be set | |
97 | * on the command line. | |
98 | */ | |
99 | int stdin_null_flag = 0; | |
100 | ||
101 | /* | |
102 | * Flag indicating that ssh should fork after authentication. This is useful | |
103 | * so that the passphrase can be entered manually, and then ssh goes to the | |
104 | * background. | |
105 | */ | |
106 | int fork_after_authentication_flag = 0; | |
107 | ||
108 | /* | |
109 | * General data structure for command line options and options configurable | |
110 | * in configuration files. See readconf.h. | |
111 | */ | |
112 | Options options; | |
113 | ||
114 | /* optional user configfile */ | |
115 | char *config = NULL; | |
116 | ||
117 | /* | |
118 | * Name of the host we are connecting to. This is the name given on the | |
119 | * command line, or the HostName specified for the user-supplied name in a | |
120 | * configuration file. | |
121 | */ | |
122 | char *host; | |
123 | ||
124 | /* socket address the host resolves to */ | |
125 | struct sockaddr_storage hostaddr; | |
126 | ||
127 | /* Private host keys. */ | |
128 | Sensitive sensitive_data; | |
129 | ||
130 | /* Original real UID. */ | |
131 | uid_t original_real_uid; | |
132 | uid_t original_effective_uid; | |
133 | ||
134 | /* command to be executed */ | |
135 | Buffer command; | |
136 | ||
137 | /* Should we execute a command or invoke a subsystem? */ | |
138 | int subsystem_flag = 0; | |
139 | ||
140 | /* # of replies received for global requests */ | |
141 | static int client_global_request_id = 0; | |
142 | ||
143 | /* pid of proxycommand child process */ | |
144 | pid_t proxy_command_pid = 0; | |
145 | ||
146 | /* fd to control socket */ | |
147 | int control_fd = -1; | |
148 | ||
149 | /* Multiplexing control command */ | |
150 | static u_int mux_command = 0; | |
151 | ||
152 | /* Only used in control client mode */ | |
153 | volatile sig_atomic_t control_client_terminate = 0; | |
154 | u_int control_server_pid = 0; | |
155 | ||
156 | /* Prints a help message to the user. This function never returns. */ | |
157 | ||
158 | static void | |
159 | usage(void) | |
160 | { | |
161 | fprintf(stderr, | |
162 | "usage: ssh [-1246AaCfgkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n" | |
163 | " [-D [bind_address:]port] [-e escape_char] [-F configfile]\n" | |
164 | " [-i identity_file] [-L [bind_address:]port:host:hostport]\n" | |
165 | " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" | |
166 | " [-R [bind_address:]port:host:hostport] [-S ctl_path]\n" | |
167 | " [-w tunnel:tunnel] [user@]hostname [command]\n" | |
168 | ); | |
169 | exit(255); | |
170 | } | |
171 | ||
172 | static int ssh_session(void); | |
173 | static int ssh_session2(void); | |
174 | static void load_public_identity_files(void); | |
175 | static void control_client(const char *path); | |
176 | ||
177 | /* | |
178 | * Main program for the ssh client. | |
179 | */ | |
180 | int | |
181 | main(int ac, char **av) | |
182 | { | |
183 | int i, opt, exit_status; | |
184 | char *p, *cp, *line, buf[256]; | |
185 | struct stat st; | |
186 | struct passwd *pw; | |
187 | int dummy; | |
188 | extern int optind, optreset; | |
189 | extern char *optarg; | |
190 | struct servent *sp; | |
191 | Forward fwd; | |
192 | ||
193 | /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ | |
194 | sanitise_stdfd(); | |
195 | ||
196 | __progname = ssh_get_progname(av[0]); | |
197 | init_rng(); | |
198 | ||
199 | /* | |
200 | * Save the original real uid. It will be needed later (uid-swapping | |
201 | * may clobber the real uid). | |
202 | */ | |
203 | original_real_uid = getuid(); | |
204 | original_effective_uid = geteuid(); | |
205 | ||
206 | /* | |
207 | * Use uid-swapping to give up root privileges for the duration of | |
208 | * option processing. We will re-instantiate the rights when we are | |
209 | * ready to create the privileged port, and will permanently drop | |
210 | * them when the port has been created (actually, when the connection | |
211 | * has been made, as we may need to create the port several times). | |
212 | */ | |
213 | PRIV_END; | |
214 | ||
215 | #ifdef HAVE_SETRLIMIT | |
216 | /* If we are installed setuid root be careful to not drop core. */ | |
217 | if (original_real_uid != original_effective_uid) { | |
218 | struct rlimit rlim; | |
219 | rlim.rlim_cur = rlim.rlim_max = 0; | |
220 | if (setrlimit(RLIMIT_CORE, &rlim) < 0) | |
221 | fatal("setrlimit failed: %.100s", strerror(errno)); | |
222 | } | |
223 | #endif | |
224 | /* Get user data. */ | |
225 | pw = getpwuid(original_real_uid); | |
226 | if (!pw) { | |
227 | logit("You don't exist, go away!"); | |
228 | exit(255); | |
229 | } | |
230 | /* Take a copy of the returned structure. */ | |
231 | pw = pwcopy(pw); | |
232 | ||
233 | /* | |
234 | * Set our umask to something reasonable, as some files are created | |
235 | * with the default umask. This will make them world-readable but | |
236 | * writable only by the owner, which is ok for all files for which we | |
237 | * don't set the modes explicitly. | |
238 | */ | |
239 | umask(022); | |
240 | ||
241 | /* Initialize option structure to indicate that no values have been set. */ | |
242 | initialize_options(&options); | |
243 | ||
244 | /* Parse command-line arguments. */ | |
245 | host = NULL; | |
246 | ||
247 | again: | |
248 | while ((opt = getopt(ac, av, | |
249 | "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNO:PR:S:TVw:XY")) != -1) { | |
250 | switch (opt) { | |
251 | case '1': | |
252 | options.protocol = SSH_PROTO_1; | |
253 | break; | |
254 | case '2': | |
255 | options.protocol = SSH_PROTO_2; | |
256 | break; | |
257 | case '4': | |
258 | options.address_family = AF_INET; | |
259 | break; | |
260 | case '6': | |
261 | options.address_family = AF_INET6; | |
262 | break; | |
263 | case 'n': | |
264 | stdin_null_flag = 1; | |
265 | break; | |
266 | case 'f': | |
267 | fork_after_authentication_flag = 1; | |
268 | stdin_null_flag = 1; | |
269 | break; | |
270 | case 'x': | |
271 | options.forward_x11 = 0; | |
272 | break; | |
273 | case 'X': | |
274 | options.forward_x11 = 1; | |
275 | break; | |
276 | case 'Y': | |
277 | options.forward_x11 = 1; | |
278 | options.forward_x11_trusted = 1; | |
279 | break; | |
280 | case 'g': | |
281 | options.gateway_ports = 1; | |
282 | break; | |
283 | case 'O': | |
284 | if (strcmp(optarg, "check") == 0) | |
285 | mux_command = SSHMUX_COMMAND_ALIVE_CHECK; | |
286 | else if (strcmp(optarg, "exit") == 0) | |
287 | mux_command = SSHMUX_COMMAND_TERMINATE; | |
288 | else | |
289 | fatal("Invalid multiplex command."); | |
290 | break; | |
291 | case 'P': /* deprecated */ | |
292 | options.use_privileged_port = 0; | |
293 | break; | |
294 | case 'a': | |
295 | options.forward_agent = 0; | |
296 | break; | |
297 | case 'A': | |
298 | options.forward_agent = 1; | |
299 | break; | |
300 | case 'k': | |
301 | options.gss_deleg_creds = 0; | |
302 | break; | |
303 | case 'i': | |
304 | if (stat(optarg, &st) < 0) { | |
305 | fprintf(stderr, "Warning: Identity file %s " | |
306 | "not accessible: %s.\n", optarg, | |
307 | strerror(errno)); | |
308 | break; | |
309 | } | |
310 | if (options.num_identity_files >= | |
311 | SSH_MAX_IDENTITY_FILES) | |
312 | fatal("Too many identity files specified " | |
313 | "(max %d)", SSH_MAX_IDENTITY_FILES); | |
314 | options.identity_files[options.num_identity_files++] = | |
315 | xstrdup(optarg); | |
316 | break; | |
317 | case 'I': | |
318 | #ifdef SMARTCARD | |
319 | options.smartcard_device = xstrdup(optarg); | |
320 | #else | |
321 | fprintf(stderr, "no support for smartcards.\n"); | |
322 | #endif | |
323 | break; | |
324 | case 't': | |
325 | if (tty_flag) | |
326 | force_tty_flag = 1; | |
327 | tty_flag = 1; | |
328 | break; | |
329 | case 'v': | |
330 | if (debug_flag == 0) { | |
331 | debug_flag = 1; | |
332 | options.log_level = SYSLOG_LEVEL_DEBUG1; | |
333 | } else { | |
334 | if (options.log_level < SYSLOG_LEVEL_DEBUG3) | |
335 | options.log_level++; | |
336 | break; | |
337 | } | |
338 | /* FALLTHROUGH */ | |
339 | case 'V': | |
340 | fprintf(stderr, "%s, %s\n", | |
341 | SSH_RELEASE, SSLeay_version(SSLEAY_VERSION)); | |
342 | if (opt == 'V') | |
343 | exit(0); | |
344 | break; | |
345 | case 'w': | |
346 | if (options.tun_open == -1) | |
347 | options.tun_open = SSH_TUNMODE_DEFAULT; | |
348 | options.tun_local = a2tun(optarg, &options.tun_remote); | |
349 | if (options.tun_local == SSH_TUNID_ERR) { | |
350 | fprintf(stderr, "Bad tun device '%s'\n", optarg); | |
351 | exit(255); | |
352 | } | |
353 | break; | |
354 | case 'q': | |
355 | options.log_level = SYSLOG_LEVEL_QUIET; | |
356 | break; | |
357 | case 'e': | |
358 | if (optarg[0] == '^' && optarg[2] == 0 && | |
359 | (u_char) optarg[1] >= 64 && | |
360 | (u_char) optarg[1] < 128) | |
361 | options.escape_char = (u_char) optarg[1] & 31; | |
362 | else if (strlen(optarg) == 1) | |
363 | options.escape_char = (u_char) optarg[0]; | |
364 | else if (strcmp(optarg, "none") == 0) | |
365 | options.escape_char = SSH_ESCAPECHAR_NONE; | |
366 | else { | |
367 | fprintf(stderr, "Bad escape character '%s'.\n", | |
368 | optarg); | |
369 | exit(255); | |
370 | } | |
371 | break; | |
372 | case 'c': | |
373 | if (ciphers_valid(optarg)) { | |
374 | /* SSH2 only */ | |
375 | options.ciphers = xstrdup(optarg); | |
376 | options.cipher = SSH_CIPHER_INVALID; | |
377 | } else { | |
378 | /* SSH1 only */ | |
379 | options.cipher = cipher_number(optarg); | |
380 | if (options.cipher == -1) { | |
381 | fprintf(stderr, | |
382 | "Unknown cipher type '%s'\n", | |
383 | optarg); | |
384 | exit(255); | |
385 | } | |
386 | if (options.cipher == SSH_CIPHER_3DES) | |
387 | options.ciphers = "3des-cbc"; | |
388 | else if (options.cipher == SSH_CIPHER_BLOWFISH) | |
389 | options.ciphers = "blowfish-cbc"; | |
390 | else | |
391 | options.ciphers = (char *)-1; | |
392 | } | |
393 | break; | |
394 | case 'm': | |
395 | if (mac_valid(optarg)) | |
396 | options.macs = xstrdup(optarg); | |
397 | else { | |
398 | fprintf(stderr, "Unknown mac type '%s'\n", | |
399 | optarg); | |
400 | exit(255); | |
401 | } | |
402 | break; | |
403 | case 'M': | |
404 | if (options.control_master == SSHCTL_MASTER_YES) | |
405 | options.control_master = SSHCTL_MASTER_ASK; | |
406 | else | |
407 | options.control_master = SSHCTL_MASTER_YES; | |
408 | break; | |
409 | case 'p': | |
410 | options.port = a2port(optarg); | |
411 | if (options.port == 0) { | |
412 | fprintf(stderr, "Bad port '%s'\n", optarg); | |
413 | exit(255); | |
414 | } | |
415 | break; | |
416 | case 'l': | |
417 | options.user = optarg; | |
418 | break; | |
419 | ||
420 | case 'L': | |
421 | if (parse_forward(&fwd, optarg)) | |
422 | add_local_forward(&options, &fwd); | |
423 | else { | |
424 | fprintf(stderr, | |
425 | "Bad local forwarding specification '%s'\n", | |
426 | optarg); | |
427 | exit(255); | |
428 | } | |
429 | break; | |
430 | ||
431 | case 'R': | |
432 | if (parse_forward(&fwd, optarg)) { | |
433 | add_remote_forward(&options, &fwd); | |
434 | } else { | |
435 | fprintf(stderr, | |
436 | "Bad remote forwarding specification " | |
437 | "'%s'\n", optarg); | |
438 | exit(255); | |
439 | } | |
440 | break; | |
441 | ||
442 | case 'D': | |
443 | cp = p = xstrdup(optarg); | |
444 | memset(&fwd, '\0', sizeof(fwd)); | |
445 | fwd.connect_host = "socks"; | |
446 | if ((fwd.listen_host = hpdelim(&cp)) == NULL) { | |
447 | fprintf(stderr, "Bad dynamic forwarding " | |
448 | "specification '%.100s'\n", optarg); | |
449 | exit(255); | |
450 | } | |
451 | if (cp != NULL) { | |
452 | fwd.listen_port = a2port(cp); | |
453 | fwd.listen_host = cleanhostname(fwd.listen_host); | |
454 | } else { | |
455 | fwd.listen_port = a2port(fwd.listen_host); | |
456 | fwd.listen_host = NULL; | |
457 | } | |
458 | ||
459 | if (fwd.listen_port == 0) { | |
460 | fprintf(stderr, "Bad dynamic port '%s'\n", | |
461 | optarg); | |
462 | exit(255); | |
463 | } | |
464 | add_local_forward(&options, &fwd); | |
465 | xfree(p); | |
466 | break; | |
467 | ||
468 | case 'C': | |
469 | options.compression = 1; | |
470 | break; | |
471 | case 'N': | |
472 | no_shell_flag = 1; | |
473 | no_tty_flag = 1; | |
474 | break; | |
475 | case 'T': | |
476 | no_tty_flag = 1; | |
477 | break; | |
478 | case 'o': | |
479 | dummy = 1; | |
480 | line = xstrdup(optarg); | |
481 | if (process_config_line(&options, host ? host : "", | |
482 | line, "command-line", 0, &dummy) != 0) | |
483 | exit(255); | |
484 | xfree(line); | |
485 | break; | |
486 | case 's': | |
487 | subsystem_flag = 1; | |
488 | break; | |
489 | case 'S': | |
490 | if (options.control_path != NULL) | |
491 | free(options.control_path); | |
492 | options.control_path = xstrdup(optarg); | |
493 | break; | |
494 | case 'b': | |
495 | options.bind_address = optarg; | |
496 | break; | |
497 | case 'F': | |
498 | config = optarg; | |
499 | break; | |
500 | default: | |
501 | usage(); | |
502 | } | |
503 | } | |
504 | ||
505 | ac -= optind; | |
506 | av += optind; | |
507 | ||
508 | if (ac > 0 && !host && **av != '-') { | |
509 | if (strrchr(*av, '@')) { | |
510 | p = xstrdup(*av); | |
511 | cp = strrchr(p, '@'); | |
512 | if (cp == NULL || cp == p) | |
513 | usage(); | |
514 | options.user = p; | |
515 | *cp = '\0'; | |
516 | host = ++cp; | |
517 | } else | |
518 | host = *av; | |
519 | if (ac > 1) { | |
520 | optind = optreset = 1; | |
521 | goto again; | |
522 | } | |
523 | ac--, av++; | |
524 | } | |
525 | ||
526 | /* Check that we got a host name. */ | |
527 | if (!host) | |
528 | usage(); | |
529 | ||
530 | SSLeay_add_all_algorithms(); | |
531 | ERR_load_crypto_strings(); | |
532 | ||
533 | /* Initialize the command to execute on remote host. */ | |
534 | buffer_init(&command); | |
535 | ||
536 | /* | |
537 | * Save the command to execute on the remote host in a buffer. There | |
538 | * is no limit on the length of the command, except by the maximum | |
539 | * packet size. Also sets the tty flag if there is no command. | |
540 | */ | |
541 | if (!ac) { | |
542 | /* No command specified - execute shell on a tty. */ | |
543 | tty_flag = 1; | |
544 | if (subsystem_flag) { | |
545 | fprintf(stderr, | |
546 | "You must specify a subsystem to invoke.\n"); | |
547 | usage(); | |
548 | } | |
549 | } else { | |
550 | /* A command has been specified. Store it into the buffer. */ | |
551 | for (i = 0; i < ac; i++) { | |
552 | if (i) | |
553 | buffer_append(&command, " ", 1); | |
554 | buffer_append(&command, av[i], strlen(av[i])); | |
555 | } | |
556 | } | |
557 | ||
558 | /* Cannot fork to background if no command. */ | |
559 | if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag) | |
560 | fatal("Cannot fork into background without a command to execute."); | |
561 | ||
562 | /* Allocate a tty by default if no command specified. */ | |
563 | if (buffer_len(&command) == 0) | |
564 | tty_flag = 1; | |
565 | ||
566 | /* Force no tty */ | |
567 | if (no_tty_flag) | |
568 | tty_flag = 0; | |
569 | /* Do not allocate a tty if stdin is not a tty. */ | |
570 | if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) { | |
571 | if (tty_flag) | |
572 | logit("Pseudo-terminal will not be allocated because stdin is not a terminal."); | |
573 | tty_flag = 0; | |
574 | } | |
575 | ||
576 | /* | |
577 | * Initialize "log" output. Since we are the client all output | |
578 | * actually goes to stderr. | |
579 | */ | |
580 | log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, | |
581 | SYSLOG_FACILITY_USER, 1); | |
582 | ||
583 | /* | |
584 | * Read per-user configuration file. Ignore the system wide config | |
585 | * file if the user specifies a config file on the command line. | |
586 | */ | |
587 | if (config != NULL) { | |
588 | if (!read_config_file(config, host, &options, 0)) | |
589 | fatal("Can't open user config file %.100s: " | |
590 | "%.100s", config, strerror(errno)); | |
591 | } else { | |
592 | snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, | |
593 | _PATH_SSH_USER_CONFFILE); | |
594 | (void)read_config_file(buf, host, &options, 1); | |
595 | ||
596 | /* Read systemwide configuration file after use config. */ | |
597 | (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, | |
598 | &options, 0); | |
599 | } | |
600 | ||
601 | /* Fill configuration defaults. */ | |
602 | fill_default_options(&options); | |
603 | ||
604 | channel_set_af(options.address_family); | |
605 | ||
606 | /* reinit */ | |
607 | log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1); | |
608 | ||
609 | seed_rng(); | |
610 | ||
611 | if (options.user == NULL) | |
612 | options.user = xstrdup(pw->pw_name); | |
613 | ||
614 | if (options.hostname != NULL) | |
615 | host = options.hostname; | |
616 | ||
617 | /* force lowercase for hostkey matching */ | |
618 | if (options.host_key_alias != NULL) { | |
619 | for (p = options.host_key_alias; *p; p++) | |
620 | if (isupper(*p)) | |
621 | *p = tolower(*p); | |
622 | } | |
623 | ||
624 | /* Get default port if port has not been set. */ | |
625 | if (options.port == 0) { | |
626 | sp = getservbyname(SSH_SERVICE_NAME, "tcp"); | |
627 | options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT; | |
628 | } | |
629 | ||
630 | if (options.proxy_command != NULL && | |
631 | strcmp(options.proxy_command, "none") == 0) | |
632 | options.proxy_command = NULL; | |
633 | if (options.control_path != NULL && | |
634 | strcmp(options.control_path, "none") == 0) | |
635 | options.control_path = NULL; | |
636 | ||
637 | if (options.control_path != NULL) { | |
638 | snprintf(buf, sizeof(buf), "%d", options.port); | |
639 | cp = tilde_expand_filename(options.control_path, | |
640 | original_real_uid); | |
641 | options.control_path = percent_expand(cp, "p", buf, "h", host, | |
642 | "r", options.user, (char *)NULL); | |
643 | xfree(cp); | |
644 | } | |
645 | if (mux_command != 0 && options.control_path == NULL) | |
646 | fatal("No ControlPath specified for \"-O\" command"); | |
647 | if (options.control_path != NULL) | |
648 | control_client(options.control_path); | |
649 | ||
650 | /* Open a connection to the remote host. */ | |
651 | if (ssh_connect(host, &hostaddr, options.port, | |
652 | options.address_family, options.connection_attempts, | |
653 | #ifdef HAVE_CYGWIN | |
654 | options.use_privileged_port, | |
655 | #else | |
656 | original_effective_uid == 0 && options.use_privileged_port, | |
657 | #endif | |
658 | options.proxy_command) != 0) | |
659 | exit(255); | |
660 | ||
661 | /* | |
662 | * If we successfully made the connection, load the host private key | |
663 | * in case we will need it later for combined rsa-rhosts | |
664 | * authentication. This must be done before releasing extra | |
665 | * privileges, because the file is only readable by root. | |
666 | * If we cannot access the private keys, load the public keys | |
667 | * instead and try to execute the ssh-keysign helper instead. | |
668 | */ | |
669 | sensitive_data.nkeys = 0; | |
670 | sensitive_data.keys = NULL; | |
671 | sensitive_data.external_keysign = 0; | |
672 | if (options.rhosts_rsa_authentication || | |
673 | options.hostbased_authentication) { | |
674 | sensitive_data.nkeys = 3; | |
675 | sensitive_data.keys = xmalloc(sensitive_data.nkeys * | |
676 | sizeof(Key)); | |
677 | ||
678 | PRIV_START; | |
679 | sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, | |
680 | _PATH_HOST_KEY_FILE, "", NULL); | |
681 | sensitive_data.keys[1] = key_load_private_type(KEY_DSA, | |
682 | _PATH_HOST_DSA_KEY_FILE, "", NULL); | |
683 | sensitive_data.keys[2] = key_load_private_type(KEY_RSA, | |
684 | _PATH_HOST_RSA_KEY_FILE, "", NULL); | |
685 | PRIV_END; | |
686 | ||
687 | if (options.hostbased_authentication == 1 && | |
688 | sensitive_data.keys[0] == NULL && | |
689 | sensitive_data.keys[1] == NULL && | |
690 | sensitive_data.keys[2] == NULL) { | |
691 | sensitive_data.keys[1] = key_load_public( | |
692 | _PATH_HOST_DSA_KEY_FILE, NULL); | |
693 | sensitive_data.keys[2] = key_load_public( | |
694 | _PATH_HOST_RSA_KEY_FILE, NULL); | |
695 | sensitive_data.external_keysign = 1; | |
696 | } | |
697 | } | |
698 | /* | |
699 | * Get rid of any extra privileges that we may have. We will no | |
700 | * longer need them. Also, extra privileges could make it very hard | |
701 | * to read identity files and other non-world-readable files from the | |
702 | * user's home directory if it happens to be on a NFS volume where | |
703 | * root is mapped to nobody. | |
704 | */ | |
705 | if (original_effective_uid == 0) { | |
706 | PRIV_START; | |
707 | permanently_set_uid(pw); | |
708 | } | |
709 | ||
710 | /* | |
711 | * Now that we are back to our own permissions, create ~/.ssh | |
712 | * directory if it doesn't already exist. | |
713 | */ | |
714 | snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); | |
715 | if (stat(buf, &st) < 0) | |
716 | if (mkdir(buf, 0700) < 0) | |
717 | error("Could not create directory '%.200s'.", buf); | |
718 | ||
719 | /* load options.identity_files */ | |
720 | load_public_identity_files(); | |
721 | ||
722 | /* Expand ~ in known host file names. */ | |
723 | /* XXX mem-leaks: */ | |
724 | options.system_hostfile = | |
725 | tilde_expand_filename(options.system_hostfile, original_real_uid); | |
726 | options.user_hostfile = | |
727 | tilde_expand_filename(options.user_hostfile, original_real_uid); | |
728 | options.system_hostfile2 = | |
729 | tilde_expand_filename(options.system_hostfile2, original_real_uid); | |
730 | options.user_hostfile2 = | |
731 | tilde_expand_filename(options.user_hostfile2, original_real_uid); | |
732 | ||
733 | signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ | |
734 | ||
735 | /* Log into the remote system. This never returns if the login fails. */ | |
736 | ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw); | |
737 | ||
738 | /* We no longer need the private host keys. Clear them now. */ | |
739 | if (sensitive_data.nkeys != 0) { | |
740 | for (i = 0; i < sensitive_data.nkeys; i++) { | |
741 | if (sensitive_data.keys[i] != NULL) { | |
742 | /* Destroys contents safely */ | |
743 | debug3("clear hostkey %d", i); | |
744 | key_free(sensitive_data.keys[i]); | |
745 | sensitive_data.keys[i] = NULL; | |
746 | } | |
747 | } | |
748 | xfree(sensitive_data.keys); | |
749 | } | |
750 | for (i = 0; i < options.num_identity_files; i++) { | |
751 | if (options.identity_files[i]) { | |
752 | xfree(options.identity_files[i]); | |
753 | options.identity_files[i] = NULL; | |
754 | } | |
755 | if (options.identity_keys[i]) { | |
756 | key_free(options.identity_keys[i]); | |
757 | options.identity_keys[i] = NULL; | |
758 | } | |
759 | } | |
760 | ||
761 | exit_status = compat20 ? ssh_session2() : ssh_session(); | |
762 | packet_close(); | |
763 | ||
764 | if (options.control_path != NULL && control_fd != -1) | |
765 | unlink(options.control_path); | |
766 | ||
767 | /* | |
768 | * Send SIGHUP to proxy command if used. We don't wait() in | |
769 | * case it hangs and instead rely on init to reap the child | |
770 | */ | |
771 | if (proxy_command_pid > 1) | |
772 | kill(proxy_command_pid, SIGHUP); | |
773 | ||
774 | return exit_status; | |
775 | } | |
776 | ||
777 | static void | |
778 | ssh_init_forwarding(void) | |
779 | { | |
780 | int success = 0; | |
781 | int i; | |
782 | ||
783 | /* Initiate local TCP/IP port forwardings. */ | |
784 | for (i = 0; i < options.num_local_forwards; i++) { | |
785 | debug("Local connections to %.200s:%d forwarded to remote " | |
786 | "address %.200s:%d", | |
787 | (options.local_forwards[i].listen_host == NULL) ? | |
788 | (options.gateway_ports ? "*" : "LOCALHOST") : | |
789 | options.local_forwards[i].listen_host, | |
790 | options.local_forwards[i].listen_port, | |
791 | options.local_forwards[i].connect_host, | |
792 | options.local_forwards[i].connect_port); | |
793 | success += channel_setup_local_fwd_listener( | |
794 | options.local_forwards[i].listen_host, | |
795 | options.local_forwards[i].listen_port, | |
796 | options.local_forwards[i].connect_host, | |
797 | options.local_forwards[i].connect_port, | |
798 | options.gateway_ports); | |
799 | } | |
800 | if (i > 0 && success == 0) | |
801 | error("Could not request local forwarding."); | |
802 | ||
803 | /* Initiate remote TCP/IP port forwardings. */ | |
804 | for (i = 0; i < options.num_remote_forwards; i++) { | |
805 | debug("Remote connections from %.200s:%d forwarded to " | |
806 | "local address %.200s:%d", | |
807 | (options.remote_forwards[i].listen_host == NULL) ? | |
808 | "LOCALHOST" : options.remote_forwards[i].listen_host, | |
809 | options.remote_forwards[i].listen_port, | |
810 | options.remote_forwards[i].connect_host, | |
811 | options.remote_forwards[i].connect_port); | |
812 | channel_request_remote_forwarding( | |
813 | options.remote_forwards[i].listen_host, | |
814 | options.remote_forwards[i].listen_port, | |
815 | options.remote_forwards[i].connect_host, | |
816 | options.remote_forwards[i].connect_port); | |
817 | } | |
818 | } | |
819 | ||
820 | static void | |
821 | check_agent_present(void) | |
822 | { | |
823 | if (options.forward_agent) { | |
824 | /* Clear agent forwarding if we don't have an agent. */ | |
825 | if (!ssh_agent_present()) | |
826 | options.forward_agent = 0; | |
827 | } | |
828 | } | |
829 | ||
830 | static int | |
831 | ssh_session(void) | |
832 | { | |
833 | int type; | |
834 | int interactive = 0; | |
835 | int have_tty = 0; | |
836 | struct winsize ws; | |
837 | char *cp; | |
838 | const char *display; | |
839 | ||
840 | /* Enable compression if requested. */ | |
841 | if (options.compression) { | |
842 | debug("Requesting compression at level %d.", options.compression_level); | |
843 | ||
844 | if (options.compression_level < 1 || options.compression_level > 9) | |
845 | fatal("Compression level must be from 1 (fast) to 9 (slow, best)."); | |
846 | ||
847 | /* Send the request. */ | |
848 | packet_start(SSH_CMSG_REQUEST_COMPRESSION); | |
849 | packet_put_int(options.compression_level); | |
850 | packet_send(); | |
851 | packet_write_wait(); | |
852 | type = packet_read(); | |
853 | if (type == SSH_SMSG_SUCCESS) | |
854 | packet_start_compression(options.compression_level); | |
855 | else if (type == SSH_SMSG_FAILURE) | |
856 | logit("Warning: Remote host refused compression."); | |
857 | else | |
858 | packet_disconnect("Protocol error waiting for compression response."); | |
859 | } | |
860 | /* Allocate a pseudo tty if appropriate. */ | |
861 | if (tty_flag) { | |
862 | debug("Requesting pty."); | |
863 | ||
864 | /* Start the packet. */ | |
865 | packet_start(SSH_CMSG_REQUEST_PTY); | |
866 | ||
867 | /* Store TERM in the packet. There is no limit on the | |
868 | length of the string. */ | |
869 | cp = getenv("TERM"); | |
870 | if (!cp) | |
871 | cp = ""; | |
872 | packet_put_cstring(cp); | |
873 | ||
874 | /* Store window size in the packet. */ | |
875 | if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) | |
876 | memset(&ws, 0, sizeof(ws)); | |
877 | packet_put_int(ws.ws_row); | |
878 | packet_put_int(ws.ws_col); | |
879 | packet_put_int(ws.ws_xpixel); | |
880 | packet_put_int(ws.ws_ypixel); | |
881 | ||
882 | /* Store tty modes in the packet. */ | |
883 | tty_make_modes(fileno(stdin), NULL); | |
884 | ||
885 | /* Send the packet, and wait for it to leave. */ | |
886 | packet_send(); | |
887 | packet_write_wait(); | |
888 | ||
889 | /* Read response from the server. */ | |
890 | type = packet_read(); | |
891 | if (type == SSH_SMSG_SUCCESS) { | |
892 | interactive = 1; | |
893 | have_tty = 1; | |
894 | } else if (type == SSH_SMSG_FAILURE) | |
895 | logit("Warning: Remote host failed or refused to allocate a pseudo tty."); | |
896 | else | |
897 | packet_disconnect("Protocol error waiting for pty request response."); | |
898 | } | |
899 | /* Request X11 forwarding if enabled and DISPLAY is set. */ | |
900 | display = getenv("DISPLAY"); | |
901 | if (options.forward_x11 && display != NULL) { | |
902 | char *proto, *data; | |
903 | /* Get reasonable local authentication information. */ | |
904 | client_x11_get_proto(display, options.xauth_location, | |
905 | options.forward_x11_trusted, &proto, &data); | |
906 | /* Request forwarding with authentication spoofing. */ | |
907 | debug("Requesting X11 forwarding with authentication spoofing."); | |
908 | x11_request_forwarding_with_spoofing(0, display, proto, data); | |
909 | ||
910 | /* Read response from the server. */ | |
911 | type = packet_read(); | |
912 | if (type == SSH_SMSG_SUCCESS) { | |
913 | interactive = 1; | |
914 | } else if (type == SSH_SMSG_FAILURE) { | |
915 | logit("Warning: Remote host denied X11 forwarding."); | |
916 | } else { | |
917 | packet_disconnect("Protocol error waiting for X11 forwarding"); | |
918 | } | |
919 | } | |
920 | /* Tell the packet module whether this is an interactive session. */ | |
921 | packet_set_interactive(interactive); | |
922 | ||
923 | /* Request authentication agent forwarding if appropriate. */ | |
924 | check_agent_present(); | |
925 | ||
926 | if (options.forward_agent) { | |
927 | debug("Requesting authentication agent forwarding."); | |
928 | auth_request_forwarding(); | |
929 | ||
930 | /* Read response from the server. */ | |
931 | type = packet_read(); | |
932 | packet_check_eom(); | |
933 | if (type != SSH_SMSG_SUCCESS) | |
934 | logit("Warning: Remote host denied authentication agent forwarding."); | |
935 | } | |
936 | ||
937 | /* Initiate port forwardings. */ | |
938 | ssh_init_forwarding(); | |
939 | ||
940 | /* If requested, let ssh continue in the background. */ | |
941 | if (fork_after_authentication_flag) | |
942 | if (daemon(1, 1) < 0) | |
943 | fatal("daemon() failed: %.200s", strerror(errno)); | |
944 | ||
945 | /* | |
946 | * If a command was specified on the command line, execute the | |
947 | * command now. Otherwise request the server to start a shell. | |
948 | */ | |
949 | if (buffer_len(&command) > 0) { | |
950 | int len = buffer_len(&command); | |
951 | if (len > 900) | |
952 | len = 900; | |
953 | debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command)); | |
954 | packet_start(SSH_CMSG_EXEC_CMD); | |
955 | packet_put_string(buffer_ptr(&command), buffer_len(&command)); | |
956 | packet_send(); | |
957 | packet_write_wait(); | |
958 | } else { | |
959 | debug("Requesting shell."); | |
960 | packet_start(SSH_CMSG_EXEC_SHELL); | |
961 | packet_send(); | |
962 | packet_write_wait(); | |
963 | } | |
964 | ||
965 | /* Enter the interactive session. */ | |
966 | return client_loop(have_tty, tty_flag ? | |
967 | options.escape_char : SSH_ESCAPECHAR_NONE, 0); | |
968 | } | |
969 | ||
970 | static void | |
971 | ssh_subsystem_reply(int type, u_int32_t seq, void *ctxt) | |
972 | { | |
973 | int id, len; | |
974 | ||
975 | id = packet_get_int(); | |
976 | len = buffer_len(&command); | |
977 | if (len > 900) | |
978 | len = 900; | |
979 | packet_check_eom(); | |
980 | if (type == SSH2_MSG_CHANNEL_FAILURE) | |
981 | fatal("Request for subsystem '%.*s' failed on channel %d", | |
982 | len, (u_char *)buffer_ptr(&command), id); | |
983 | } | |
984 | ||
985 | void | |
986 | client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt) | |
987 | { | |
988 | int i; | |
989 | ||
990 | i = client_global_request_id++; | |
991 | if (i >= options.num_remote_forwards) | |
992 | return; | |
993 | debug("remote forward %s for: listen %d, connect %s:%d", | |
994 | type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", | |
995 | options.remote_forwards[i].listen_port, | |
996 | options.remote_forwards[i].connect_host, | |
997 | options.remote_forwards[i].connect_port); | |
998 | if (type == SSH2_MSG_REQUEST_FAILURE) | |
999 | logit("Warning: remote port forwarding failed for listen " | |
1000 | "port %d", options.remote_forwards[i].listen_port); | |
1001 | } | |
1002 | ||
1003 | static void | |
1004 | ssh_control_listener(void) | |
1005 | { | |
1006 | struct sockaddr_un addr; | |
1007 | mode_t old_umask; | |
1008 | int addr_len; | |
1009 | ||
1010 | if (options.control_path == NULL || | |
1011 | options.control_master == SSHCTL_MASTER_NO) | |
1012 | return; | |
1013 | ||
1014 | debug("setting up multiplex master socket"); | |
1015 | ||
1016 | memset(&addr, '\0', sizeof(addr)); | |
1017 | addr.sun_family = AF_UNIX; | |
1018 | addr_len = offsetof(struct sockaddr_un, sun_path) + | |
1019 | strlen(options.control_path) + 1; | |
1020 | ||
1021 | if (strlcpy(addr.sun_path, options.control_path, | |
1022 | sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) | |
1023 | fatal("ControlPath too long"); | |
1024 | ||
1025 | if ((control_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) | |
1026 | fatal("%s socket(): %s", __func__, strerror(errno)); | |
1027 | ||
1028 | old_umask = umask(0177); | |
1029 | if (bind(control_fd, (struct sockaddr*)&addr, addr_len) == -1) { | |
1030 | control_fd = -1; | |
1031 | if (errno == EINVAL || errno == EADDRINUSE) | |
1032 | fatal("ControlSocket %s already exists", | |
1033 | options.control_path); | |
1034 | else | |
1035 | fatal("%s bind(): %s", __func__, strerror(errno)); | |
1036 | } | |
1037 | umask(old_umask); | |
1038 | ||
1039 | if (listen(control_fd, 64) == -1) | |
1040 | fatal("%s listen(): %s", __func__, strerror(errno)); | |
1041 | ||
1042 | set_nonblock(control_fd); | |
1043 | } | |
1044 | ||
1045 | /* request pty/x11/agent/tcpfwd/shell for channel */ | |
1046 | static void | |
1047 | ssh_session2_setup(int id, void *arg) | |
1048 | { | |
1049 | extern char **environ; | |
1050 | const char *display; | |
1051 | int interactive = tty_flag; | |
1052 | ||
1053 | display = getenv("DISPLAY"); | |
1054 | if (options.forward_x11 && display != NULL) { | |
1055 | char *proto, *data; | |
1056 | /* Get reasonable local authentication information. */ | |
1057 | client_x11_get_proto(display, options.xauth_location, | |
1058 | options.forward_x11_trusted, &proto, &data); | |
1059 | /* Request forwarding with authentication spoofing. */ | |
1060 | debug("Requesting X11 forwarding with authentication spoofing."); | |
1061 | x11_request_forwarding_with_spoofing(id, display, proto, data); | |
1062 | interactive = 1; | |
1063 | /* XXX wait for reply */ | |
1064 | } | |
1065 | ||
1066 | check_agent_present(); | |
1067 | if (options.forward_agent) { | |
1068 | debug("Requesting authentication agent forwarding."); | |
1069 | channel_request_start(id, "auth-agent-req@openssh.com", 0); | |
1070 | packet_send(); | |
1071 | } | |
1072 | ||
1073 | if (options.tun_open != SSH_TUNMODE_NO) { | |
1074 | Channel *c; | |
1075 | int fd; | |
1076 | ||
1077 | debug("Requesting tun."); | |
1078 | if ((fd = tun_open(options.tun_local, | |
1079 | options.tun_open)) >= 0) { | |
1080 | c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, | |
1081 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, | |
1082 | 0, "tun", 1); | |
1083 | c->datagram = 1; | |
1084 | #if defined(SSH_TUN_FILTER) | |
1085 | if (options.tun_open == SSH_TUNMODE_POINTOPOINT) | |
1086 | channel_register_filter(c->self, sys_tun_infilter, | |
1087 | sys_tun_outfilter); | |
1088 | #endif | |
1089 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
1090 | packet_put_cstring("tun@openssh.com"); | |
1091 | packet_put_int(c->self); | |
1092 | packet_put_int(c->local_window_max); | |
1093 | packet_put_int(c->local_maxpacket); | |
1094 | packet_put_int(options.tun_open); | |
1095 | packet_put_int(options.tun_remote); | |
1096 | packet_send(); | |
1097 | } | |
1098 | } | |
1099 | ||
1100 | client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), | |
1101 | NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply); | |
1102 | ||
1103 | packet_set_interactive(interactive); | |
1104 | } | |
1105 | ||
1106 | /* open new channel for a session */ | |
1107 | static int | |
1108 | ssh_session2_open(void) | |
1109 | { | |
1110 | Channel *c; | |
1111 | int window, packetmax, in, out, err; | |
1112 | ||
1113 | if (stdin_null_flag) { | |
1114 | in = open(_PATH_DEVNULL, O_RDONLY); | |
1115 | } else { | |
1116 | in = dup(STDIN_FILENO); | |
1117 | } | |
1118 | out = dup(STDOUT_FILENO); | |
1119 | err = dup(STDERR_FILENO); | |
1120 | ||
1121 | if (in < 0 || out < 0 || err < 0) | |
1122 | fatal("dup() in/out/err failed"); | |
1123 | ||
1124 | /* enable nonblocking unless tty */ | |
1125 | if (!isatty(in)) | |
1126 | set_nonblock(in); | |
1127 | if (!isatty(out)) | |
1128 | set_nonblock(out); | |
1129 | if (!isatty(err)) | |
1130 | set_nonblock(err); | |
1131 | ||
1132 | window = CHAN_SES_WINDOW_DEFAULT; | |
1133 | packetmax = CHAN_SES_PACKET_DEFAULT; | |
1134 | if (tty_flag) { | |
1135 | window >>= 1; | |
1136 | packetmax >>= 1; | |
1137 | } | |
1138 | c = channel_new( | |
1139 | "session", SSH_CHANNEL_OPENING, in, out, err, | |
1140 | window, packetmax, CHAN_EXTENDED_WRITE, | |
1141 | "client-session", /*nonblock*/0); | |
1142 | ||
1143 | debug3("ssh_session2_open: channel_new: %d", c->self); | |
1144 | ||
1145 | channel_send_open(c->self); | |
1146 | if (!no_shell_flag) | |
1147 | channel_register_confirm(c->self, ssh_session2_setup, NULL); | |
1148 | ||
1149 | return c->self; | |
1150 | } | |
1151 | ||
1152 | static int | |
1153 | ssh_session2(void) | |
1154 | { | |
1155 | int id = -1; | |
1156 | ||
1157 | /* XXX should be pre-session */ | |
1158 | ssh_init_forwarding(); | |
1159 | ssh_control_listener(); | |
1160 | ||
1161 | if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) | |
1162 | id = ssh_session2_open(); | |
1163 | ||
1164 | /* Execute a local command */ | |
1165 | if (options.local_command != NULL && | |
1166 | options.permit_local_command) | |
1167 | ssh_local_cmd(options.local_command); | |
1168 | ||
1169 | /* If requested, let ssh continue in the background. */ | |
1170 | if (fork_after_authentication_flag) | |
1171 | if (daemon(1, 1) < 0) | |
1172 | fatal("daemon() failed: %.200s", strerror(errno)); | |
1173 | ||
1174 | return client_loop(tty_flag, tty_flag ? | |
1175 | options.escape_char : SSH_ESCAPECHAR_NONE, id); | |
1176 | } | |
1177 | ||
1178 | static void | |
1179 | load_public_identity_files(void) | |
1180 | { | |
1181 | char *filename; | |
1182 | int i = 0; | |
1183 | Key *public; | |
1184 | #ifdef SMARTCARD | |
1185 | Key **keys; | |
1186 | ||
1187 | if (options.smartcard_device != NULL && | |
1188 | options.num_identity_files < SSH_MAX_IDENTITY_FILES && | |
1189 | (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL ) { | |
1190 | int count = 0; | |
1191 | for (i = 0; keys[i] != NULL; i++) { | |
1192 | count++; | |
1193 | memmove(&options.identity_files[1], &options.identity_files[0], | |
1194 | sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1)); | |
1195 | memmove(&options.identity_keys[1], &options.identity_keys[0], | |
1196 | sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1)); | |
1197 | options.num_identity_files++; | |
1198 | options.identity_keys[0] = keys[i]; | |
1199 | options.identity_files[0] = sc_get_key_label(keys[i]); | |
1200 | } | |
1201 | if (options.num_identity_files > SSH_MAX_IDENTITY_FILES) | |
1202 | options.num_identity_files = SSH_MAX_IDENTITY_FILES; | |
1203 | i = count; | |
1204 | xfree(keys); | |
1205 | } | |
1206 | #endif /* SMARTCARD */ | |
1207 | for (; i < options.num_identity_files; i++) { | |
1208 | filename = tilde_expand_filename(options.identity_files[i], | |
1209 | original_real_uid); | |
1210 | public = key_load_public(filename, NULL); | |
1211 | debug("identity file %s type %d", filename, | |
1212 | public ? public->type : -1); | |
1213 | xfree(options.identity_files[i]); | |
1214 | options.identity_files[i] = filename; | |
1215 | options.identity_keys[i] = public; | |
1216 | } | |
1217 | } | |
1218 | ||
1219 | static void | |
1220 | control_client_sighandler(int signo) | |
1221 | { | |
1222 | control_client_terminate = signo; | |
1223 | } | |
1224 | ||
1225 | static void | |
1226 | control_client_sigrelay(int signo) | |
1227 | { | |
1228 | if (control_server_pid > 1) | |
1229 | kill(control_server_pid, signo); | |
1230 | } | |
1231 | ||
1232 | static int | |
1233 | env_permitted(char *env) | |
1234 | { | |
1235 | int i; | |
1236 | char name[1024], *cp; | |
1237 | ||
1238 | strlcpy(name, env, sizeof(name)); | |
1239 | if ((cp = strchr(name, '=')) == NULL) | |
1240 | return (0); | |
1241 | ||
1242 | *cp = '\0'; | |
1243 | ||
1244 | for (i = 0; i < options.num_send_env; i++) | |
1245 | if (match_pattern(name, options.send_env[i])) | |
1246 | return (1); | |
1247 | ||
1248 | return (0); | |
1249 | } | |
1250 | ||
1251 | static void | |
1252 | control_client(const char *path) | |
1253 | { | |
1254 | struct sockaddr_un addr; | |
1255 | int i, r, fd, sock, exitval, num_env, addr_len; | |
1256 | Buffer m; | |
1257 | char *term; | |
1258 | extern char **environ; | |
1259 | u_int flags; | |
1260 | ||
1261 | if (mux_command == 0) | |
1262 | mux_command = SSHMUX_COMMAND_OPEN; | |
1263 | ||
1264 | switch (options.control_master) { | |
1265 | case SSHCTL_MASTER_AUTO: | |
1266 | case SSHCTL_MASTER_AUTO_ASK: | |
1267 | debug("auto-mux: Trying existing master"); | |
1268 | /* FALLTHROUGH */ | |
1269 | case SSHCTL_MASTER_NO: | |
1270 | break; | |
1271 | default: | |
1272 | return; | |
1273 | } | |
1274 | ||
1275 | memset(&addr, '\0', sizeof(addr)); | |
1276 | addr.sun_family = AF_UNIX; | |
1277 | addr_len = offsetof(struct sockaddr_un, sun_path) + | |
1278 | strlen(path) + 1; | |
1279 | ||
1280 | if (strlcpy(addr.sun_path, path, | |
1281 | sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) | |
1282 | fatal("ControlPath too long"); | |
1283 | ||
1284 | if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) | |
1285 | fatal("%s socket(): %s", __func__, strerror(errno)); | |
1286 | ||
1287 | if (connect(sock, (struct sockaddr*)&addr, addr_len) == -1) { | |
1288 | if (mux_command != SSHMUX_COMMAND_OPEN) { | |
1289 | fatal("Control socket connect(%.100s): %s", path, | |
1290 | strerror(errno)); | |
1291 | } | |
1292 | if (errno == ENOENT) | |
1293 | debug("Control socket \"%.100s\" does not exist", path); | |
1294 | else { | |
1295 | error("Control socket connect(%.100s): %s", path, | |
1296 | strerror(errno)); | |
1297 | } | |
1298 | close(sock); | |
1299 | return; | |
1300 | } | |
1301 | ||
1302 | if (stdin_null_flag) { | |
1303 | if ((fd = open(_PATH_DEVNULL, O_RDONLY)) == -1) | |
1304 | fatal("open(/dev/null): %s", strerror(errno)); | |
1305 | if (dup2(fd, STDIN_FILENO) == -1) | |
1306 | fatal("dup2: %s", strerror(errno)); | |
1307 | if (fd > STDERR_FILENO) | |
1308 | close(fd); | |
1309 | } | |
1310 | ||
1311 | term = getenv("TERM"); | |
1312 | ||
1313 | flags = 0; | |
1314 | if (tty_flag) | |
1315 | flags |= SSHMUX_FLAG_TTY; | |
1316 | if (subsystem_flag) | |
1317 | flags |= SSHMUX_FLAG_SUBSYS; | |
1318 | if (options.forward_x11) | |
1319 | flags |= SSHMUX_FLAG_X11_FWD; | |
1320 | if (options.forward_agent) | |
1321 | flags |= SSHMUX_FLAG_AGENT_FWD; | |
1322 | ||
1323 | buffer_init(&m); | |
1324 | ||
1325 | /* Send our command to server */ | |
1326 | buffer_put_int(&m, mux_command); | |
1327 | buffer_put_int(&m, flags); | |
1328 | if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) | |
1329 | fatal("%s: msg_send", __func__); | |
1330 | buffer_clear(&m); | |
1331 | ||
1332 | /* Get authorisation status and PID of controlee */ | |
1333 | if (ssh_msg_recv(sock, &m) == -1) | |
1334 | fatal("%s: msg_recv", __func__); | |
1335 | if (buffer_get_char(&m) != SSHMUX_VER) | |
1336 | fatal("%s: wrong version", __func__); | |
1337 | if (buffer_get_int(&m) != 1) | |
1338 | fatal("Connection to master denied"); | |
1339 | control_server_pid = buffer_get_int(&m); | |
1340 | ||
1341 | buffer_clear(&m); | |
1342 | ||
1343 | switch (mux_command) { | |
1344 | case SSHMUX_COMMAND_ALIVE_CHECK: | |
1345 | fprintf(stderr, "Master running (pid=%d)\r\n", | |
1346 | control_server_pid); | |
1347 | exit(0); | |
1348 | case SSHMUX_COMMAND_TERMINATE: | |
1349 | fprintf(stderr, "Exit request sent.\r\n"); | |
1350 | exit(0); | |
1351 | case SSHMUX_COMMAND_OPEN: | |
1352 | /* continue below */ | |
1353 | break; | |
1354 | default: | |
1355 | fatal("silly mux_command %d", mux_command); | |
1356 | } | |
1357 | ||
1358 | /* SSHMUX_COMMAND_OPEN */ | |
1359 | buffer_put_cstring(&m, term ? term : ""); | |
1360 | buffer_append(&command, "\0", 1); | |
1361 | buffer_put_cstring(&m, buffer_ptr(&command)); | |
1362 | ||
1363 | if (options.num_send_env == 0 || environ == NULL) { | |
1364 | buffer_put_int(&m, 0); | |
1365 | } else { | |
1366 | /* Pass environment */ | |
1367 | num_env = 0; | |
1368 | for (i = 0; environ[i] != NULL; i++) | |
1369 | if (env_permitted(environ[i])) | |
1370 | num_env++; /* Count */ | |
1371 | ||
1372 | buffer_put_int(&m, num_env); | |
1373 | ||
1374 | for (i = 0; environ[i] != NULL && num_env >= 0; i++) | |
1375 | if (env_permitted(environ[i])) { | |
1376 | num_env--; | |
1377 | buffer_put_cstring(&m, environ[i]); | |
1378 | } | |
1379 | } | |
1380 | ||
1381 | if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) | |
1382 | fatal("%s: msg_send", __func__); | |
1383 | ||
1384 | mm_send_fd(sock, STDIN_FILENO); | |
1385 | mm_send_fd(sock, STDOUT_FILENO); | |
1386 | mm_send_fd(sock, STDERR_FILENO); | |
1387 | ||
1388 | /* Wait for reply, so master has a chance to gather ttymodes */ | |
1389 | buffer_clear(&m); | |
1390 | if (ssh_msg_recv(sock, &m) == -1) | |
1391 | fatal("%s: msg_recv", __func__); | |
1392 | if (buffer_get_char(&m) != SSHMUX_VER) | |
1393 | fatal("%s: wrong version", __func__); | |
1394 | buffer_free(&m); | |
1395 | ||
1396 | signal(SIGHUP, control_client_sighandler); | |
1397 | signal(SIGINT, control_client_sighandler); | |
1398 | signal(SIGTERM, control_client_sighandler); | |
1399 | signal(SIGWINCH, control_client_sigrelay); | |
1400 | ||
1401 | if (tty_flag) | |
1402 | enter_raw_mode(); | |
1403 | ||
1404 | /* Stick around until the controlee closes the client_fd */ | |
1405 | exitval = 0; | |
1406 | for (;!control_client_terminate;) { | |
1407 | r = read(sock, &exitval, sizeof(exitval)); | |
1408 | if (r == 0) { | |
1409 | debug2("Received EOF from master"); | |
1410 | break; | |
1411 | } | |
1412 | if (r > 0) | |
1413 | debug2("Received exit status from master %d", exitval); | |
1414 | if (r == -1 && errno != EINTR) | |
1415 | fatal("%s: read %s", __func__, strerror(errno)); | |
1416 | } | |
1417 | ||
1418 | if (control_client_terminate) | |
1419 | debug2("Exiting on signal %d", control_client_terminate); | |
1420 | ||
1421 | close(sock); | |
1422 | ||
1423 | leave_raw_mode(); | |
1424 | ||
1425 | if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET) | |
1426 | fprintf(stderr, "Connection to master closed.\r\n"); | |
1427 | ||
1428 | exit(exitval); | |
1429 | } |