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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 1.264 2006/02/20 17:19:54 stevesk Exp $"); | |
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/un.h> | |
52 | ||
53 | #include <paths.h> | |
54 | #include <signal.h> | |
55 | ||
56 | #include <openssl/evp.h> | |
57 | #include <openssl/err.h> | |
58 | ||
59 | #include "ssh.h" | |
60 | #include "ssh1.h" | |
61 | #include "ssh2.h" | |
62 | #include "compat.h" | |
63 | #include "cipher.h" | |
64 | #include "xmalloc.h" | |
65 | #include "packet.h" | |
66 | #include "buffer.h" | |
67 | #include "bufaux.h" | |
68 | #include "channels.h" | |
69 | #include "key.h" | |
70 | #include "authfd.h" | |
71 | #include "authfile.h" | |
72 | #include "pathnames.h" | |
73 | #include "dispatch.h" | |
74 | #include "clientloop.h" | |
75 | #include "log.h" | |
76 | #include "readconf.h" | |
77 | #include "sshconnect.h" | |
78 | #include "misc.h" | |
79 | #include "kex.h" | |
80 | #include "mac.h" | |
81 | #include "sshpty.h" | |
82 | #include "match.h" | |
83 | #include "msg.h" | |
84 | #include "monitor_fdpass.h" | |
85 | #include "uidswap.h" | |
86 | ||
87 | #ifdef SMARTCARD | |
88 | #include "scard.h" | |
89 | #endif | |
90 | ||
91 | extern char *__progname; | |
92 | ||
93 | /* Flag indicating whether debug mode is on. This can be set on the command line. */ | |
94 | int debug_flag = 0; | |
95 | ||
96 | /* Flag indicating whether a tty should be allocated */ | |
97 | int tty_flag = 0; | |
98 | int no_tty_flag = 0; | |
99 | int force_tty_flag = 0; | |
100 | ||
101 | /* don't exec a shell */ | |
102 | int no_shell_flag = 0; | |
103 | ||
104 | /* | |
105 | * Flag indicating that nothing should be read from stdin. This can be set | |
106 | * on the command line. | |
107 | */ | |
108 | int stdin_null_flag = 0; | |
109 | ||
110 | /* | |
111 | * Flag indicating that ssh should fork after authentication. This is useful | |
112 | * so that the passphrase can be entered manually, and then ssh goes to the | |
113 | * background. | |
114 | */ | |
115 | int fork_after_authentication_flag = 0; | |
116 | ||
117 | /* | |
118 | * General data structure for command line options and options configurable | |
119 | * in configuration files. See readconf.h. | |
120 | */ | |
121 | Options options; | |
122 | ||
123 | /* optional user configfile */ | |
124 | char *config = NULL; | |
125 | ||
126 | /* | |
127 | * Name of the host we are connecting to. This is the name given on the | |
128 | * command line, or the HostName specified for the user-supplied name in a | |
129 | * configuration file. | |
130 | */ | |
131 | char *host; | |
132 | ||
133 | /* socket address the host resolves to */ | |
134 | struct sockaddr_storage hostaddr; | |
135 | ||
136 | /* Private host keys. */ | |
137 | Sensitive sensitive_data; | |
138 | ||
139 | /* Original real UID. */ | |
140 | uid_t original_real_uid; | |
141 | uid_t original_effective_uid; | |
142 | ||
143 | /* command to be executed */ | |
144 | Buffer command; | |
145 | ||
146 | /* Should we execute a command or invoke a subsystem? */ | |
147 | int subsystem_flag = 0; | |
148 | ||
149 | /* # of replies received for global requests */ | |
150 | static int client_global_request_id = 0; | |
151 | ||
152 | /* pid of proxycommand child process */ | |
153 | pid_t proxy_command_pid = 0; | |
154 | ||
155 | /* fd to control socket */ | |
156 | int control_fd = -1; | |
157 | ||
158 | /* Multiplexing control command */ | |
159 | static u_int mux_command = 0; | |
160 | ||
161 | /* Only used in control client mode */ | |
162 | volatile sig_atomic_t control_client_terminate = 0; | |
163 | u_int control_server_pid = 0; | |
164 | ||
165 | /* Prints a help message to the user. This function never returns. */ | |
166 | ||
167 | static void | |
168 | usage(void) | |
169 | { | |
170 | fprintf(stderr, | |
171 | "usage: ssh [-1246AaCfgkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n" | |
172 | " [-D [bind_address:]port] [-e escape_char] [-F configfile]\n" | |
173 | " [-i identity_file] [-L [bind_address:]port:host:hostport]\n" | |
174 | " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" | |
175 | " [-R [bind_address:]port:host:hostport] [-S ctl_path]\n" | |
176 | " [-w tunnel:tunnel] [user@]hostname [command]\n" | |
177 | ); | |
178 | exit(255); | |
179 | } | |
180 | ||
181 | static int ssh_session(void); | |
182 | static int ssh_session2(void); | |
183 | static void load_public_identity_files(void); | |
184 | static void control_client(const char *path); | |
185 | ||
186 | /* | |
187 | * Main program for the ssh client. | |
188 | */ | |
189 | int | |
190 | main(int ac, char **av) | |
191 | { | |
192 | int i, opt, exit_status; | |
193 | char *p, *cp, *line, buf[256]; | |
194 | struct stat st; | |
195 | struct passwd *pw; | |
196 | int dummy; | |
197 | extern int optind, optreset; | |
198 | extern char *optarg; | |
199 | struct servent *sp; | |
200 | Forward fwd; | |
201 | ||
202 | /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ | |
203 | sanitise_stdfd(); | |
204 | ||
205 | __progname = ssh_get_progname(av[0]); | |
206 | init_rng(); | |
207 | ||
208 | /* | |
209 | * Save the original real uid. It will be needed later (uid-swapping | |
210 | * may clobber the real uid). | |
211 | */ | |
212 | original_real_uid = getuid(); | |
213 | original_effective_uid = geteuid(); | |
214 | ||
215 | /* | |
216 | * Use uid-swapping to give up root privileges for the duration of | |
217 | * option processing. We will re-instantiate the rights when we are | |
218 | * ready to create the privileged port, and will permanently drop | |
219 | * them when the port has been created (actually, when the connection | |
220 | * has been made, as we may need to create the port several times). | |
221 | */ | |
222 | PRIV_END; | |
223 | ||
224 | #ifdef HAVE_SETRLIMIT | |
225 | /* If we are installed setuid root be careful to not drop core. */ | |
226 | if (original_real_uid != original_effective_uid) { | |
227 | struct rlimit rlim; | |
228 | rlim.rlim_cur = rlim.rlim_max = 0; | |
229 | if (setrlimit(RLIMIT_CORE, &rlim) < 0) | |
230 | fatal("setrlimit failed: %.100s", strerror(errno)); | |
231 | } | |
232 | #endif | |
233 | /* Get user data. */ | |
234 | pw = getpwuid(original_real_uid); | |
235 | if (!pw) { | |
236 | logit("You don't exist, go away!"); | |
237 | exit(255); | |
238 | } | |
239 | /* Take a copy of the returned structure. */ | |
240 | pw = pwcopy(pw); | |
241 | ||
242 | /* | |
243 | * Set our umask to something reasonable, as some files are created | |
244 | * with the default umask. This will make them world-readable but | |
245 | * writable only by the owner, which is ok for all files for which we | |
246 | * don't set the modes explicitly. | |
247 | */ | |
248 | umask(022); | |
249 | ||
250 | /* Initialize option structure to indicate that no values have been set. */ | |
251 | initialize_options(&options); | |
252 | ||
253 | /* Parse command-line arguments. */ | |
254 | host = NULL; | |
255 | ||
256 | again: | |
257 | while ((opt = getopt(ac, av, | |
258 | "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNO:PR:S:TVw:XY")) != -1) { | |
259 | switch (opt) { | |
260 | case '1': | |
261 | options.protocol = SSH_PROTO_1; | |
262 | break; | |
263 | case '2': | |
264 | options.protocol = SSH_PROTO_2; | |
265 | break; | |
266 | case '4': | |
267 | options.address_family = AF_INET; | |
268 | break; | |
269 | case '6': | |
270 | options.address_family = AF_INET6; | |
271 | break; | |
272 | case 'n': | |
273 | stdin_null_flag = 1; | |
274 | break; | |
275 | case 'f': | |
276 | fork_after_authentication_flag = 1; | |
277 | stdin_null_flag = 1; | |
278 | break; | |
279 | case 'x': | |
280 | options.forward_x11 = 0; | |
281 | break; | |
282 | case 'X': | |
283 | options.forward_x11 = 1; | |
284 | break; | |
285 | case 'Y': | |
286 | options.forward_x11 = 1; | |
287 | options.forward_x11_trusted = 1; | |
288 | break; | |
289 | case 'g': | |
290 | options.gateway_ports = 1; | |
291 | break; | |
292 | case 'O': | |
293 | if (strcmp(optarg, "check") == 0) | |
294 | mux_command = SSHMUX_COMMAND_ALIVE_CHECK; | |
295 | else if (strcmp(optarg, "exit") == 0) | |
296 | mux_command = SSHMUX_COMMAND_TERMINATE; | |
297 | else | |
298 | fatal("Invalid multiplex command."); | |
299 | break; | |
300 | case 'P': /* deprecated */ | |
301 | options.use_privileged_port = 0; | |
302 | break; | |
303 | case 'a': | |
304 | options.forward_agent = 0; | |
305 | break; | |
306 | case 'A': | |
307 | options.forward_agent = 1; | |
308 | break; | |
309 | case 'k': | |
310 | options.gss_deleg_creds = 0; | |
311 | break; | |
312 | case 'i': | |
313 | if (stat(optarg, &st) < 0) { | |
314 | fprintf(stderr, "Warning: Identity file %s " | |
315 | "not accessible: %s.\n", optarg, | |
316 | strerror(errno)); | |
317 | break; | |
318 | } | |
319 | if (options.num_identity_files >= | |
320 | SSH_MAX_IDENTITY_FILES) | |
321 | fatal("Too many identity files specified " | |
322 | "(max %d)", SSH_MAX_IDENTITY_FILES); | |
323 | options.identity_files[options.num_identity_files++] = | |
324 | xstrdup(optarg); | |
325 | break; | |
326 | case 'I': | |
327 | #ifdef SMARTCARD | |
328 | options.smartcard_device = xstrdup(optarg); | |
329 | #else | |
330 | fprintf(stderr, "no support for smartcards.\n"); | |
331 | #endif | |
332 | break; | |
333 | case 't': | |
334 | if (tty_flag) | |
335 | force_tty_flag = 1; | |
336 | tty_flag = 1; | |
337 | break; | |
338 | case 'v': | |
339 | if (debug_flag == 0) { | |
340 | debug_flag = 1; | |
341 | options.log_level = SYSLOG_LEVEL_DEBUG1; | |
342 | } else { | |
343 | if (options.log_level < SYSLOG_LEVEL_DEBUG3) | |
344 | options.log_level++; | |
345 | break; | |
346 | } | |
347 | /* FALLTHROUGH */ | |
348 | case 'V': | |
349 | fprintf(stderr, "%s, %s\n", | |
350 | SSH_RELEASE, SSLeay_version(SSLEAY_VERSION)); | |
351 | if (opt == 'V') | |
352 | exit(0); | |
353 | break; | |
354 | case 'w': | |
355 | if (options.tun_open == -1) | |
356 | options.tun_open = SSH_TUNMODE_DEFAULT; | |
357 | options.tun_local = a2tun(optarg, &options.tun_remote); | |
358 | if (options.tun_local == SSH_TUNID_ERR) { | |
359 | fprintf(stderr, "Bad tun device '%s'\n", optarg); | |
360 | exit(255); | |
361 | } | |
362 | break; | |
363 | case 'q': | |
364 | options.log_level = SYSLOG_LEVEL_QUIET; | |
365 | break; | |
366 | case 'e': | |
367 | if (optarg[0] == '^' && optarg[2] == 0 && | |
368 | (u_char) optarg[1] >= 64 && | |
369 | (u_char) optarg[1] < 128) | |
370 | options.escape_char = (u_char) optarg[1] & 31; | |
371 | else if (strlen(optarg) == 1) | |
372 | options.escape_char = (u_char) optarg[0]; | |
373 | else if (strcmp(optarg, "none") == 0) | |
374 | options.escape_char = SSH_ESCAPECHAR_NONE; | |
375 | else { | |
376 | fprintf(stderr, "Bad escape character '%s'.\n", | |
377 | optarg); | |
378 | exit(255); | |
379 | } | |
380 | break; | |
381 | case 'c': | |
382 | if (ciphers_valid(optarg)) { | |
383 | /* SSH2 only */ | |
384 | options.ciphers = xstrdup(optarg); | |
385 | options.cipher = SSH_CIPHER_INVALID; | |
386 | } else { | |
387 | /* SSH1 only */ | |
388 | options.cipher = cipher_number(optarg); | |
389 | if (options.cipher == -1) { | |
390 | fprintf(stderr, | |
391 | "Unknown cipher type '%s'\n", | |
392 | optarg); | |
393 | exit(255); | |
394 | } | |
395 | if (options.cipher == SSH_CIPHER_3DES) | |
396 | options.ciphers = "3des-cbc"; | |
397 | else if (options.cipher == SSH_CIPHER_BLOWFISH) | |
398 | options.ciphers = "blowfish-cbc"; | |
399 | else | |
400 | options.ciphers = (char *)-1; | |
401 | } | |
402 | break; | |
403 | case 'm': | |
404 | if (mac_valid(optarg)) | |
405 | options.macs = xstrdup(optarg); | |
406 | else { | |
407 | fprintf(stderr, "Unknown mac type '%s'\n", | |
408 | optarg); | |
409 | exit(255); | |
410 | } | |
411 | break; | |
412 | case 'M': | |
413 | if (options.control_master == SSHCTL_MASTER_YES) | |
414 | options.control_master = SSHCTL_MASTER_ASK; | |
415 | else | |
416 | options.control_master = SSHCTL_MASTER_YES; | |
417 | break; | |
418 | case 'p': | |
419 | options.port = a2port(optarg); | |
420 | if (options.port == 0) { | |
421 | fprintf(stderr, "Bad port '%s'\n", optarg); | |
422 | exit(255); | |
423 | } | |
424 | break; | |
425 | case 'l': | |
426 | options.user = optarg; | |
427 | break; | |
428 | ||
429 | case 'L': | |
430 | if (parse_forward(&fwd, optarg)) | |
431 | add_local_forward(&options, &fwd); | |
432 | else { | |
433 | fprintf(stderr, | |
434 | "Bad local forwarding specification '%s'\n", | |
435 | optarg); | |
436 | exit(255); | |
437 | } | |
438 | break; | |
439 | ||
440 | case 'R': | |
441 | if (parse_forward(&fwd, optarg)) { | |
442 | add_remote_forward(&options, &fwd); | |
443 | } else { | |
444 | fprintf(stderr, | |
445 | "Bad remote forwarding specification " | |
446 | "'%s'\n", optarg); | |
447 | exit(255); | |
448 | } | |
449 | break; | |
450 | ||
451 | case 'D': | |
452 | cp = p = xstrdup(optarg); | |
453 | memset(&fwd, '\0', sizeof(fwd)); | |
454 | fwd.connect_host = "socks"; | |
455 | if ((fwd.listen_host = hpdelim(&cp)) == NULL) { | |
456 | fprintf(stderr, "Bad dynamic forwarding " | |
457 | "specification '%.100s'\n", optarg); | |
458 | exit(255); | |
459 | } | |
460 | if (cp != NULL) { | |
461 | fwd.listen_port = a2port(cp); | |
462 | fwd.listen_host = cleanhostname(fwd.listen_host); | |
463 | } else { | |
464 | fwd.listen_port = a2port(fwd.listen_host); | |
465 | fwd.listen_host = NULL; | |
466 | } | |
467 | ||
468 | if (fwd.listen_port == 0) { | |
469 | fprintf(stderr, "Bad dynamic port '%s'\n", | |
470 | optarg); | |
471 | exit(255); | |
472 | } | |
473 | add_local_forward(&options, &fwd); | |
474 | xfree(p); | |
475 | break; | |
476 | ||
477 | case 'C': | |
478 | options.compression = 1; | |
479 | break; | |
480 | case 'N': | |
481 | no_shell_flag = 1; | |
482 | no_tty_flag = 1; | |
483 | break; | |
484 | case 'T': | |
485 | no_tty_flag = 1; | |
486 | break; | |
487 | case 'o': | |
488 | dummy = 1; | |
489 | line = xstrdup(optarg); | |
490 | if (process_config_line(&options, host ? host : "", | |
491 | line, "command-line", 0, &dummy) != 0) | |
492 | exit(255); | |
493 | xfree(line); | |
494 | break; | |
495 | case 's': | |
496 | subsystem_flag = 1; | |
497 | break; | |
498 | case 'S': | |
499 | if (options.control_path != NULL) | |
500 | free(options.control_path); | |
501 | options.control_path = xstrdup(optarg); | |
502 | break; | |
503 | case 'b': | |
504 | options.bind_address = optarg; | |
505 | break; | |
506 | case 'F': | |
507 | config = optarg; | |
508 | break; | |
509 | default: | |
510 | usage(); | |
511 | } | |
512 | } | |
513 | ||
514 | ac -= optind; | |
515 | av += optind; | |
516 | ||
517 | if (ac > 0 && !host && **av != '-') { | |
518 | if (strrchr(*av, '@')) { | |
519 | p = xstrdup(*av); | |
520 | cp = strrchr(p, '@'); | |
521 | if (cp == NULL || cp == p) | |
522 | usage(); | |
523 | options.user = p; | |
524 | *cp = '\0'; | |
525 | host = ++cp; | |
526 | } else | |
527 | host = *av; | |
528 | if (ac > 1) { | |
529 | optind = optreset = 1; | |
530 | goto again; | |
531 | } | |
532 | ac--, av++; | |
533 | } | |
534 | ||
535 | /* Check that we got a host name. */ | |
536 | if (!host) | |
537 | usage(); | |
538 | ||
539 | SSLeay_add_all_algorithms(); | |
540 | ERR_load_crypto_strings(); | |
541 | ||
542 | /* Initialize the command to execute on remote host. */ | |
543 | buffer_init(&command); | |
544 | ||
545 | /* | |
546 | * Save the command to execute on the remote host in a buffer. There | |
547 | * is no limit on the length of the command, except by the maximum | |
548 | * packet size. Also sets the tty flag if there is no command. | |
549 | */ | |
550 | if (!ac) { | |
551 | /* No command specified - execute shell on a tty. */ | |
552 | tty_flag = 1; | |
553 | if (subsystem_flag) { | |
554 | fprintf(stderr, | |
555 | "You must specify a subsystem to invoke.\n"); | |
556 | usage(); | |
557 | } | |
558 | } else { | |
559 | /* A command has been specified. Store it into the buffer. */ | |
560 | for (i = 0; i < ac; i++) { | |
561 | if (i) | |
562 | buffer_append(&command, " ", 1); | |
563 | buffer_append(&command, av[i], strlen(av[i])); | |
564 | } | |
565 | } | |
566 | ||
567 | /* Cannot fork to background if no command. */ | |
568 | if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag) | |
569 | fatal("Cannot fork into background without a command to execute."); | |
570 | ||
571 | /* Allocate a tty by default if no command specified. */ | |
572 | if (buffer_len(&command) == 0) | |
573 | tty_flag = 1; | |
574 | ||
575 | /* Force no tty */ | |
576 | if (no_tty_flag) | |
577 | tty_flag = 0; | |
578 | /* Do not allocate a tty if stdin is not a tty. */ | |
579 | if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) { | |
580 | if (tty_flag) | |
581 | logit("Pseudo-terminal will not be allocated because stdin is not a terminal."); | |
582 | tty_flag = 0; | |
583 | } | |
584 | ||
585 | /* | |
586 | * Initialize "log" output. Since we are the client all output | |
587 | * actually goes to stderr. | |
588 | */ | |
589 | log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, | |
590 | SYSLOG_FACILITY_USER, 1); | |
591 | ||
592 | /* | |
593 | * Read per-user configuration file. Ignore the system wide config | |
594 | * file if the user specifies a config file on the command line. | |
595 | */ | |
596 | if (config != NULL) { | |
597 | if (!read_config_file(config, host, &options, 0)) | |
598 | fatal("Can't open user config file %.100s: " | |
599 | "%.100s", config, strerror(errno)); | |
600 | } else { | |
601 | snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, | |
602 | _PATH_SSH_USER_CONFFILE); | |
603 | (void)read_config_file(buf, host, &options, 1); | |
604 | ||
605 | /* Read systemwide configuration file after use config. */ | |
606 | (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, | |
607 | &options, 0); | |
608 | } | |
609 | ||
610 | /* Fill configuration defaults. */ | |
611 | fill_default_options(&options); | |
612 | ||
613 | channel_set_af(options.address_family); | |
614 | ||
615 | /* reinit */ | |
616 | log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1); | |
617 | ||
618 | seed_rng(); | |
619 | ||
620 | if (options.user == NULL) | |
621 | options.user = xstrdup(pw->pw_name); | |
622 | ||
623 | if (options.hostname != NULL) | |
624 | host = options.hostname; | |
625 | ||
626 | /* force lowercase for hostkey matching */ | |
627 | if (options.host_key_alias != NULL) { | |
628 | for (p = options.host_key_alias; *p; p++) | |
629 | if (isupper(*p)) | |
630 | *p = tolower(*p); | |
631 | } | |
632 | ||
633 | /* Get default port if port has not been set. */ | |
634 | if (options.port == 0) { | |
635 | sp = getservbyname(SSH_SERVICE_NAME, "tcp"); | |
636 | options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT; | |
637 | } | |
638 | ||
639 | if (options.proxy_command != NULL && | |
640 | strcmp(options.proxy_command, "none") == 0) | |
641 | options.proxy_command = NULL; | |
642 | if (options.control_path != NULL && | |
643 | strcmp(options.control_path, "none") == 0) | |
644 | options.control_path = NULL; | |
645 | ||
646 | if (options.control_path != NULL) { | |
647 | char me[NI_MAXHOST]; | |
648 | ||
649 | if (gethostname(me, sizeof(me)) == -1) | |
650 | fatal("gethostname: %s", strerror(errno)); | |
651 | snprintf(buf, sizeof(buf), "%d", options.port); | |
652 | cp = tilde_expand_filename(options.control_path, | |
653 | original_real_uid); | |
654 | options.control_path = percent_expand(cp, "p", buf, "h", host, | |
655 | "r", options.user, "l", me, (char *)NULL); | |
656 | xfree(cp); | |
657 | } | |
658 | if (mux_command != 0 && options.control_path == NULL) | |
659 | fatal("No ControlPath specified for \"-O\" command"); | |
660 | if (options.control_path != NULL) | |
661 | control_client(options.control_path); | |
662 | ||
663 | /* Open a connection to the remote host. */ | |
664 | if (ssh_connect(host, &hostaddr, options.port, | |
665 | options.address_family, options.connection_attempts, | |
666 | #ifdef HAVE_CYGWIN | |
667 | options.use_privileged_port, | |
668 | #else | |
669 | original_effective_uid == 0 && options.use_privileged_port, | |
670 | #endif | |
671 | options.proxy_command) != 0) | |
672 | exit(255); | |
673 | ||
674 | /* | |
675 | * If we successfully made the connection, load the host private key | |
676 | * in case we will need it later for combined rsa-rhosts | |
677 | * authentication. This must be done before releasing extra | |
678 | * privileges, because the file is only readable by root. | |
679 | * If we cannot access the private keys, load the public keys | |
680 | * instead and try to execute the ssh-keysign helper instead. | |
681 | */ | |
682 | sensitive_data.nkeys = 0; | |
683 | sensitive_data.keys = NULL; | |
684 | sensitive_data.external_keysign = 0; | |
685 | if (options.rhosts_rsa_authentication || | |
686 | options.hostbased_authentication) { | |
687 | sensitive_data.nkeys = 3; | |
688 | sensitive_data.keys = xmalloc(sensitive_data.nkeys * | |
689 | sizeof(Key)); | |
690 | ||
691 | PRIV_START; | |
692 | sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, | |
693 | _PATH_HOST_KEY_FILE, "", NULL); | |
694 | sensitive_data.keys[1] = key_load_private_type(KEY_DSA, | |
695 | _PATH_HOST_DSA_KEY_FILE, "", NULL); | |
696 | sensitive_data.keys[2] = key_load_private_type(KEY_RSA, | |
697 | _PATH_HOST_RSA_KEY_FILE, "", NULL); | |
698 | PRIV_END; | |
699 | ||
700 | if (options.hostbased_authentication == 1 && | |
701 | sensitive_data.keys[0] == NULL && | |
702 | sensitive_data.keys[1] == NULL && | |
703 | sensitive_data.keys[2] == NULL) { | |
704 | sensitive_data.keys[1] = key_load_public( | |
705 | _PATH_HOST_DSA_KEY_FILE, NULL); | |
706 | sensitive_data.keys[2] = key_load_public( | |
707 | _PATH_HOST_RSA_KEY_FILE, NULL); | |
708 | sensitive_data.external_keysign = 1; | |
709 | } | |
710 | } | |
711 | /* | |
712 | * Get rid of any extra privileges that we may have. We will no | |
713 | * longer need them. Also, extra privileges could make it very hard | |
714 | * to read identity files and other non-world-readable files from the | |
715 | * user's home directory if it happens to be on a NFS volume where | |
716 | * root is mapped to nobody. | |
717 | */ | |
718 | if (original_effective_uid == 0) { | |
719 | PRIV_START; | |
720 | permanently_set_uid(pw); | |
721 | } | |
722 | ||
723 | /* | |
724 | * Now that we are back to our own permissions, create ~/.ssh | |
725 | * directory if it doesn't already exist. | |
726 | */ | |
727 | snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); | |
728 | if (stat(buf, &st) < 0) | |
729 | if (mkdir(buf, 0700) < 0) | |
730 | error("Could not create directory '%.200s'.", buf); | |
731 | ||
732 | /* load options.identity_files */ | |
733 | load_public_identity_files(); | |
734 | ||
735 | /* Expand ~ in known host file names. */ | |
736 | /* XXX mem-leaks: */ | |
737 | options.system_hostfile = | |
738 | tilde_expand_filename(options.system_hostfile, original_real_uid); | |
739 | options.user_hostfile = | |
740 | tilde_expand_filename(options.user_hostfile, original_real_uid); | |
741 | options.system_hostfile2 = | |
742 | tilde_expand_filename(options.system_hostfile2, original_real_uid); | |
743 | options.user_hostfile2 = | |
744 | tilde_expand_filename(options.user_hostfile2, original_real_uid); | |
745 | ||
746 | signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ | |
747 | ||
748 | /* Log into the remote system. This never returns if the login fails. */ | |
749 | ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw); | |
750 | ||
751 | /* We no longer need the private host keys. Clear them now. */ | |
752 | if (sensitive_data.nkeys != 0) { | |
753 | for (i = 0; i < sensitive_data.nkeys; i++) { | |
754 | if (sensitive_data.keys[i] != NULL) { | |
755 | /* Destroys contents safely */ | |
756 | debug3("clear hostkey %d", i); | |
757 | key_free(sensitive_data.keys[i]); | |
758 | sensitive_data.keys[i] = NULL; | |
759 | } | |
760 | } | |
761 | xfree(sensitive_data.keys); | |
762 | } | |
763 | for (i = 0; i < options.num_identity_files; i++) { | |
764 | if (options.identity_files[i]) { | |
765 | xfree(options.identity_files[i]); | |
766 | options.identity_files[i] = NULL; | |
767 | } | |
768 | if (options.identity_keys[i]) { | |
769 | key_free(options.identity_keys[i]); | |
770 | options.identity_keys[i] = NULL; | |
771 | } | |
772 | } | |
773 | ||
774 | exit_status = compat20 ? ssh_session2() : ssh_session(); | |
775 | packet_close(); | |
776 | ||
777 | if (options.control_path != NULL && control_fd != -1) | |
778 | unlink(options.control_path); | |
779 | ||
780 | /* | |
781 | * Send SIGHUP to proxy command if used. We don't wait() in | |
782 | * case it hangs and instead rely on init to reap the child | |
783 | */ | |
784 | if (proxy_command_pid > 1) | |
785 | kill(proxy_command_pid, SIGHUP); | |
786 | ||
787 | return exit_status; | |
788 | } | |
789 | ||
790 | static void | |
791 | ssh_init_forwarding(void) | |
792 | { | |
793 | int success = 0; | |
794 | int i; | |
795 | ||
796 | /* Initiate local TCP/IP port forwardings. */ | |
797 | for (i = 0; i < options.num_local_forwards; i++) { | |
798 | debug("Local connections to %.200s:%d forwarded to remote " | |
799 | "address %.200s:%d", | |
800 | (options.local_forwards[i].listen_host == NULL) ? | |
801 | (options.gateway_ports ? "*" : "LOCALHOST") : | |
802 | options.local_forwards[i].listen_host, | |
803 | options.local_forwards[i].listen_port, | |
804 | options.local_forwards[i].connect_host, | |
805 | options.local_forwards[i].connect_port); | |
806 | success += channel_setup_local_fwd_listener( | |
807 | options.local_forwards[i].listen_host, | |
808 | options.local_forwards[i].listen_port, | |
809 | options.local_forwards[i].connect_host, | |
810 | options.local_forwards[i].connect_port, | |
811 | options.gateway_ports); | |
812 | } | |
813 | if (i > 0 && success == 0) | |
814 | error("Could not request local forwarding."); | |
815 | ||
816 | /* Initiate remote TCP/IP port forwardings. */ | |
817 | for (i = 0; i < options.num_remote_forwards; i++) { | |
818 | debug("Remote connections from %.200s:%d forwarded to " | |
819 | "local address %.200s:%d", | |
820 | (options.remote_forwards[i].listen_host == NULL) ? | |
821 | "LOCALHOST" : options.remote_forwards[i].listen_host, | |
822 | options.remote_forwards[i].listen_port, | |
823 | options.remote_forwards[i].connect_host, | |
824 | options.remote_forwards[i].connect_port); | |
825 | channel_request_remote_forwarding( | |
826 | options.remote_forwards[i].listen_host, | |
827 | options.remote_forwards[i].listen_port, | |
828 | options.remote_forwards[i].connect_host, | |
829 | options.remote_forwards[i].connect_port); | |
830 | } | |
831 | } | |
832 | ||
833 | static void | |
834 | check_agent_present(void) | |
835 | { | |
836 | if (options.forward_agent) { | |
837 | /* Clear agent forwarding if we don't have an agent. */ | |
838 | if (!ssh_agent_present()) | |
839 | options.forward_agent = 0; | |
840 | } | |
841 | } | |
842 | ||
843 | static int | |
844 | ssh_session(void) | |
845 | { | |
846 | int type; | |
847 | int interactive = 0; | |
848 | int have_tty = 0; | |
849 | struct winsize ws; | |
850 | char *cp; | |
851 | const char *display; | |
852 | ||
853 | /* Enable compression if requested. */ | |
854 | if (options.compression) { | |
855 | debug("Requesting compression at level %d.", options.compression_level); | |
856 | ||
857 | if (options.compression_level < 1 || options.compression_level > 9) | |
858 | fatal("Compression level must be from 1 (fast) to 9 (slow, best)."); | |
859 | ||
860 | /* Send the request. */ | |
861 | packet_start(SSH_CMSG_REQUEST_COMPRESSION); | |
862 | packet_put_int(options.compression_level); | |
863 | packet_send(); | |
864 | packet_write_wait(); | |
865 | type = packet_read(); | |
866 | if (type == SSH_SMSG_SUCCESS) | |
867 | packet_start_compression(options.compression_level); | |
868 | else if (type == SSH_SMSG_FAILURE) | |
869 | logit("Warning: Remote host refused compression."); | |
870 | else | |
871 | packet_disconnect("Protocol error waiting for compression response."); | |
872 | } | |
873 | /* Allocate a pseudo tty if appropriate. */ | |
874 | if (tty_flag) { | |
875 | debug("Requesting pty."); | |
876 | ||
877 | /* Start the packet. */ | |
878 | packet_start(SSH_CMSG_REQUEST_PTY); | |
879 | ||
880 | /* Store TERM in the packet. There is no limit on the | |
881 | length of the string. */ | |
882 | cp = getenv("TERM"); | |
883 | if (!cp) | |
884 | cp = ""; | |
885 | packet_put_cstring(cp); | |
886 | ||
887 | /* Store window size in the packet. */ | |
888 | if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) | |
889 | memset(&ws, 0, sizeof(ws)); | |
890 | packet_put_int(ws.ws_row); | |
891 | packet_put_int(ws.ws_col); | |
892 | packet_put_int(ws.ws_xpixel); | |
893 | packet_put_int(ws.ws_ypixel); | |
894 | ||
895 | /* Store tty modes in the packet. */ | |
896 | tty_make_modes(fileno(stdin), NULL); | |
897 | ||
898 | /* Send the packet, and wait for it to leave. */ | |
899 | packet_send(); | |
900 | packet_write_wait(); | |
901 | ||
902 | /* Read response from the server. */ | |
903 | type = packet_read(); | |
904 | if (type == SSH_SMSG_SUCCESS) { | |
905 | interactive = 1; | |
906 | have_tty = 1; | |
907 | } else if (type == SSH_SMSG_FAILURE) | |
908 | logit("Warning: Remote host failed or refused to allocate a pseudo tty."); | |
909 | else | |
910 | packet_disconnect("Protocol error waiting for pty request response."); | |
911 | } | |
912 | /* Request X11 forwarding if enabled and DISPLAY is set. */ | |
913 | display = getenv("DISPLAY"); | |
914 | if (options.forward_x11 && display != NULL) { | |
915 | char *proto, *data; | |
916 | /* Get reasonable local authentication information. */ | |
917 | client_x11_get_proto(display, options.xauth_location, | |
918 | options.forward_x11_trusted, &proto, &data); | |
919 | /* Request forwarding with authentication spoofing. */ | |
920 | debug("Requesting X11 forwarding with authentication spoofing."); | |
921 | x11_request_forwarding_with_spoofing(0, display, proto, data); | |
922 | ||
923 | /* Read response from the server. */ | |
924 | type = packet_read(); | |
925 | if (type == SSH_SMSG_SUCCESS) { | |
926 | interactive = 1; | |
927 | } else if (type == SSH_SMSG_FAILURE) { | |
928 | logit("Warning: Remote host denied X11 forwarding."); | |
929 | } else { | |
930 | packet_disconnect("Protocol error waiting for X11 forwarding"); | |
931 | } | |
932 | } | |
933 | /* Tell the packet module whether this is an interactive session. */ | |
934 | packet_set_interactive(interactive); | |
935 | ||
936 | /* Request authentication agent forwarding if appropriate. */ | |
937 | check_agent_present(); | |
938 | ||
939 | if (options.forward_agent) { | |
940 | debug("Requesting authentication agent forwarding."); | |
941 | auth_request_forwarding(); | |
942 | ||
943 | /* Read response from the server. */ | |
944 | type = packet_read(); | |
945 | packet_check_eom(); | |
946 | if (type != SSH_SMSG_SUCCESS) | |
947 | logit("Warning: Remote host denied authentication agent forwarding."); | |
948 | } | |
949 | ||
950 | /* Initiate port forwardings. */ | |
951 | ssh_init_forwarding(); | |
952 | ||
953 | /* If requested, let ssh continue in the background. */ | |
954 | if (fork_after_authentication_flag) | |
955 | if (daemon(1, 1) < 0) | |
956 | fatal("daemon() failed: %.200s", strerror(errno)); | |
957 | ||
958 | /* | |
959 | * If a command was specified on the command line, execute the | |
960 | * command now. Otherwise request the server to start a shell. | |
961 | */ | |
962 | if (buffer_len(&command) > 0) { | |
963 | int len = buffer_len(&command); | |
964 | if (len > 900) | |
965 | len = 900; | |
966 | debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command)); | |
967 | packet_start(SSH_CMSG_EXEC_CMD); | |
968 | packet_put_string(buffer_ptr(&command), buffer_len(&command)); | |
969 | packet_send(); | |
970 | packet_write_wait(); | |
971 | } else { | |
972 | debug("Requesting shell."); | |
973 | packet_start(SSH_CMSG_EXEC_SHELL); | |
974 | packet_send(); | |
975 | packet_write_wait(); | |
976 | } | |
977 | ||
978 | /* Enter the interactive session. */ | |
979 | return client_loop(have_tty, tty_flag ? | |
980 | options.escape_char : SSH_ESCAPECHAR_NONE, 0); | |
981 | } | |
982 | ||
983 | static void | |
984 | ssh_subsystem_reply(int type, u_int32_t seq, void *ctxt) | |
985 | { | |
986 | int id, len; | |
987 | ||
988 | id = packet_get_int(); | |
989 | len = buffer_len(&command); | |
990 | if (len > 900) | |
991 | len = 900; | |
992 | packet_check_eom(); | |
993 | if (type == SSH2_MSG_CHANNEL_FAILURE) | |
994 | fatal("Request for subsystem '%.*s' failed on channel %d", | |
995 | len, (u_char *)buffer_ptr(&command), id); | |
996 | } | |
997 | ||
998 | void | |
999 | client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt) | |
1000 | { | |
1001 | int i; | |
1002 | ||
1003 | i = client_global_request_id++; | |
1004 | if (i >= options.num_remote_forwards) | |
1005 | return; | |
1006 | debug("remote forward %s for: listen %d, connect %s:%d", | |
1007 | type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", | |
1008 | options.remote_forwards[i].listen_port, | |
1009 | options.remote_forwards[i].connect_host, | |
1010 | options.remote_forwards[i].connect_port); | |
1011 | if (type == SSH2_MSG_REQUEST_FAILURE) | |
1012 | logit("Warning: remote port forwarding failed for listen " | |
1013 | "port %d", options.remote_forwards[i].listen_port); | |
1014 | } | |
1015 | ||
1016 | static void | |
1017 | ssh_control_listener(void) | |
1018 | { | |
1019 | struct sockaddr_un addr; | |
1020 | mode_t old_umask; | |
1021 | int addr_len; | |
1022 | ||
1023 | if (options.control_path == NULL || | |
1024 | options.control_master == SSHCTL_MASTER_NO) | |
1025 | return; | |
1026 | ||
1027 | debug("setting up multiplex master socket"); | |
1028 | ||
1029 | memset(&addr, '\0', sizeof(addr)); | |
1030 | addr.sun_family = AF_UNIX; | |
1031 | addr_len = offsetof(struct sockaddr_un, sun_path) + | |
1032 | strlen(options.control_path) + 1; | |
1033 | ||
1034 | if (strlcpy(addr.sun_path, options.control_path, | |
1035 | sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) | |
1036 | fatal("ControlPath too long"); | |
1037 | ||
1038 | if ((control_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) | |
1039 | fatal("%s socket(): %s", __func__, strerror(errno)); | |
1040 | ||
1041 | old_umask = umask(0177); | |
1042 | if (bind(control_fd, (struct sockaddr*)&addr, addr_len) == -1) { | |
1043 | control_fd = -1; | |
1044 | if (errno == EINVAL || errno == EADDRINUSE) | |
1045 | fatal("ControlSocket %s already exists", | |
1046 | options.control_path); | |
1047 | else | |
1048 | fatal("%s bind(): %s", __func__, strerror(errno)); | |
1049 | } | |
1050 | umask(old_umask); | |
1051 | ||
1052 | if (listen(control_fd, 64) == -1) | |
1053 | fatal("%s listen(): %s", __func__, strerror(errno)); | |
1054 | ||
1055 | set_nonblock(control_fd); | |
1056 | } | |
1057 | ||
1058 | /* request pty/x11/agent/tcpfwd/shell for channel */ | |
1059 | static void | |
1060 | ssh_session2_setup(int id, void *arg) | |
1061 | { | |
1062 | extern char **environ; | |
1063 | const char *display; | |
1064 | int interactive = tty_flag; | |
1065 | ||
1066 | display = getenv("DISPLAY"); | |
1067 | if (options.forward_x11 && display != NULL) { | |
1068 | char *proto, *data; | |
1069 | /* Get reasonable local authentication information. */ | |
1070 | client_x11_get_proto(display, options.xauth_location, | |
1071 | options.forward_x11_trusted, &proto, &data); | |
1072 | /* Request forwarding with authentication spoofing. */ | |
1073 | debug("Requesting X11 forwarding with authentication spoofing."); | |
1074 | x11_request_forwarding_with_spoofing(id, display, proto, data); | |
1075 | interactive = 1; | |
1076 | /* XXX wait for reply */ | |
1077 | } | |
1078 | ||
1079 | check_agent_present(); | |
1080 | if (options.forward_agent) { | |
1081 | debug("Requesting authentication agent forwarding."); | |
1082 | channel_request_start(id, "auth-agent-req@openssh.com", 0); | |
1083 | packet_send(); | |
1084 | } | |
1085 | ||
1086 | if (options.tun_open != SSH_TUNMODE_NO) { | |
1087 | Channel *c; | |
1088 | int fd; | |
1089 | ||
1090 | debug("Requesting tun."); | |
1091 | if ((fd = tun_open(options.tun_local, | |
1092 | options.tun_open)) >= 0) { | |
1093 | c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, | |
1094 | CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, | |
1095 | 0, "tun", 1); | |
1096 | c->datagram = 1; | |
1097 | #if defined(SSH_TUN_FILTER) | |
1098 | if (options.tun_open == SSH_TUNMODE_POINTOPOINT) | |
1099 | channel_register_filter(c->self, sys_tun_infilter, | |
1100 | sys_tun_outfilter); | |
1101 | #endif | |
1102 | packet_start(SSH2_MSG_CHANNEL_OPEN); | |
1103 | packet_put_cstring("tun@openssh.com"); | |
1104 | packet_put_int(c->self); | |
1105 | packet_put_int(c->local_window_max); | |
1106 | packet_put_int(c->local_maxpacket); | |
1107 | packet_put_int(options.tun_open); | |
1108 | packet_put_int(options.tun_remote); | |
1109 | packet_send(); | |
1110 | } | |
1111 | } | |
1112 | ||
1113 | client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), | |
1114 | NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply); | |
1115 | ||
1116 | packet_set_interactive(interactive); | |
1117 | } | |
1118 | ||
1119 | /* open new channel for a session */ | |
1120 | static int | |
1121 | ssh_session2_open(void) | |
1122 | { | |
1123 | Channel *c; | |
1124 | int window, packetmax, in, out, err; | |
1125 | ||
1126 | if (stdin_null_flag) { | |
1127 | in = open(_PATH_DEVNULL, O_RDONLY); | |
1128 | } else { | |
1129 | in = dup(STDIN_FILENO); | |
1130 | } | |
1131 | out = dup(STDOUT_FILENO); | |
1132 | err = dup(STDERR_FILENO); | |
1133 | ||
1134 | if (in < 0 || out < 0 || err < 0) | |
1135 | fatal("dup() in/out/err failed"); | |
1136 | ||
1137 | /* enable nonblocking unless tty */ | |
1138 | if (!isatty(in)) | |
1139 | set_nonblock(in); | |
1140 | if (!isatty(out)) | |
1141 | set_nonblock(out); | |
1142 | if (!isatty(err)) | |
1143 | set_nonblock(err); | |
1144 | ||
1145 | window = CHAN_SES_WINDOW_DEFAULT; | |
1146 | packetmax = CHAN_SES_PACKET_DEFAULT; | |
1147 | if (tty_flag) { | |
1148 | window >>= 1; | |
1149 | packetmax >>= 1; | |
1150 | } | |
1151 | c = channel_new( | |
1152 | "session", SSH_CHANNEL_OPENING, in, out, err, | |
1153 | window, packetmax, CHAN_EXTENDED_WRITE, | |
1154 | "client-session", /*nonblock*/0); | |
1155 | ||
1156 | debug3("ssh_session2_open: channel_new: %d", c->self); | |
1157 | ||
1158 | channel_send_open(c->self); | |
1159 | if (!no_shell_flag) | |
1160 | channel_register_confirm(c->self, ssh_session2_setup, NULL); | |
1161 | ||
1162 | return c->self; | |
1163 | } | |
1164 | ||
1165 | static int | |
1166 | ssh_session2(void) | |
1167 | { | |
1168 | int id = -1; | |
1169 | ||
1170 | /* XXX should be pre-session */ | |
1171 | ssh_init_forwarding(); | |
1172 | ssh_control_listener(); | |
1173 | ||
1174 | if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) | |
1175 | id = ssh_session2_open(); | |
1176 | ||
1177 | /* Execute a local command */ | |
1178 | if (options.local_command != NULL && | |
1179 | options.permit_local_command) | |
1180 | ssh_local_cmd(options.local_command); | |
1181 | ||
1182 | /* If requested, let ssh continue in the background. */ | |
1183 | if (fork_after_authentication_flag) | |
1184 | if (daemon(1, 1) < 0) | |
1185 | fatal("daemon() failed: %.200s", strerror(errno)); | |
1186 | ||
1187 | return client_loop(tty_flag, tty_flag ? | |
1188 | options.escape_char : SSH_ESCAPECHAR_NONE, id); | |
1189 | } | |
1190 | ||
1191 | static void | |
1192 | load_public_identity_files(void) | |
1193 | { | |
1194 | char *filename; | |
1195 | int i = 0; | |
1196 | Key *public; | |
1197 | #ifdef SMARTCARD | |
1198 | Key **keys; | |
1199 | ||
1200 | if (options.smartcard_device != NULL && | |
1201 | options.num_identity_files < SSH_MAX_IDENTITY_FILES && | |
1202 | (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL ) { | |
1203 | int count = 0; | |
1204 | for (i = 0; keys[i] != NULL; i++) { | |
1205 | count++; | |
1206 | memmove(&options.identity_files[1], &options.identity_files[0], | |
1207 | sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1)); | |
1208 | memmove(&options.identity_keys[1], &options.identity_keys[0], | |
1209 | sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1)); | |
1210 | options.num_identity_files++; | |
1211 | options.identity_keys[0] = keys[i]; | |
1212 | options.identity_files[0] = sc_get_key_label(keys[i]); | |
1213 | } | |
1214 | if (options.num_identity_files > SSH_MAX_IDENTITY_FILES) | |
1215 | options.num_identity_files = SSH_MAX_IDENTITY_FILES; | |
1216 | i = count; | |
1217 | xfree(keys); | |
1218 | } | |
1219 | #endif /* SMARTCARD */ | |
1220 | for (; i < options.num_identity_files; i++) { | |
1221 | filename = tilde_expand_filename(options.identity_files[i], | |
1222 | original_real_uid); | |
1223 | public = key_load_public(filename, NULL); | |
1224 | debug("identity file %s type %d", filename, | |
1225 | public ? public->type : -1); | |
1226 | xfree(options.identity_files[i]); | |
1227 | options.identity_files[i] = filename; | |
1228 | options.identity_keys[i] = public; | |
1229 | } | |
1230 | } | |
1231 | ||
1232 | static void | |
1233 | control_client_sighandler(int signo) | |
1234 | { | |
1235 | control_client_terminate = signo; | |
1236 | } | |
1237 | ||
1238 | static void | |
1239 | control_client_sigrelay(int signo) | |
1240 | { | |
1241 | if (control_server_pid > 1) | |
1242 | kill(control_server_pid, signo); | |
1243 | } | |
1244 | ||
1245 | static int | |
1246 | env_permitted(char *env) | |
1247 | { | |
1248 | int i; | |
1249 | char name[1024], *cp; | |
1250 | ||
1251 | strlcpy(name, env, sizeof(name)); | |
1252 | if ((cp = strchr(name, '=')) == NULL) | |
1253 | return (0); | |
1254 | ||
1255 | *cp = '\0'; | |
1256 | ||
1257 | for (i = 0; i < options.num_send_env; i++) | |
1258 | if (match_pattern(name, options.send_env[i])) | |
1259 | return (1); | |
1260 | ||
1261 | return (0); | |
1262 | } | |
1263 | ||
1264 | static void | |
1265 | control_client(const char *path) | |
1266 | { | |
1267 | struct sockaddr_un addr; | |
1268 | int i, r, fd, sock, exitval, num_env, addr_len; | |
1269 | Buffer m; | |
1270 | char *term; | |
1271 | extern char **environ; | |
1272 | u_int flags; | |
1273 | ||
1274 | if (mux_command == 0) | |
1275 | mux_command = SSHMUX_COMMAND_OPEN; | |
1276 | ||
1277 | switch (options.control_master) { | |
1278 | case SSHCTL_MASTER_AUTO: | |
1279 | case SSHCTL_MASTER_AUTO_ASK: | |
1280 | debug("auto-mux: Trying existing master"); | |
1281 | /* FALLTHROUGH */ | |
1282 | case SSHCTL_MASTER_NO: | |
1283 | break; | |
1284 | default: | |
1285 | return; | |
1286 | } | |
1287 | ||
1288 | memset(&addr, '\0', sizeof(addr)); | |
1289 | addr.sun_family = AF_UNIX; | |
1290 | addr_len = offsetof(struct sockaddr_un, sun_path) + | |
1291 | strlen(path) + 1; | |
1292 | ||
1293 | if (strlcpy(addr.sun_path, path, | |
1294 | sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) | |
1295 | fatal("ControlPath too long"); | |
1296 | ||
1297 | if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) | |
1298 | fatal("%s socket(): %s", __func__, strerror(errno)); | |
1299 | ||
1300 | if (connect(sock, (struct sockaddr*)&addr, addr_len) == -1) { | |
1301 | if (mux_command != SSHMUX_COMMAND_OPEN) { | |
1302 | fatal("Control socket connect(%.100s): %s", path, | |
1303 | strerror(errno)); | |
1304 | } | |
1305 | if (errno == ENOENT) | |
1306 | debug("Control socket \"%.100s\" does not exist", path); | |
1307 | else { | |
1308 | error("Control socket connect(%.100s): %s", path, | |
1309 | strerror(errno)); | |
1310 | } | |
1311 | close(sock); | |
1312 | return; | |
1313 | } | |
1314 | ||
1315 | if (stdin_null_flag) { | |
1316 | if ((fd = open(_PATH_DEVNULL, O_RDONLY)) == -1) | |
1317 | fatal("open(/dev/null): %s", strerror(errno)); | |
1318 | if (dup2(fd, STDIN_FILENO) == -1) | |
1319 | fatal("dup2: %s", strerror(errno)); | |
1320 | if (fd > STDERR_FILENO) | |
1321 | close(fd); | |
1322 | } | |
1323 | ||
1324 | term = getenv("TERM"); | |
1325 | ||
1326 | flags = 0; | |
1327 | if (tty_flag) | |
1328 | flags |= SSHMUX_FLAG_TTY; | |
1329 | if (subsystem_flag) | |
1330 | flags |= SSHMUX_FLAG_SUBSYS; | |
1331 | if (options.forward_x11) | |
1332 | flags |= SSHMUX_FLAG_X11_FWD; | |
1333 | if (options.forward_agent) | |
1334 | flags |= SSHMUX_FLAG_AGENT_FWD; | |
1335 | ||
1336 | buffer_init(&m); | |
1337 | ||
1338 | /* Send our command to server */ | |
1339 | buffer_put_int(&m, mux_command); | |
1340 | buffer_put_int(&m, flags); | |
1341 | if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) | |
1342 | fatal("%s: msg_send", __func__); | |
1343 | buffer_clear(&m); | |
1344 | ||
1345 | /* Get authorisation status and PID of controlee */ | |
1346 | if (ssh_msg_recv(sock, &m) == -1) | |
1347 | fatal("%s: msg_recv", __func__); | |
1348 | if (buffer_get_char(&m) != SSHMUX_VER) | |
1349 | fatal("%s: wrong version", __func__); | |
1350 | if (buffer_get_int(&m) != 1) | |
1351 | fatal("Connection to master denied"); | |
1352 | control_server_pid = buffer_get_int(&m); | |
1353 | ||
1354 | buffer_clear(&m); | |
1355 | ||
1356 | switch (mux_command) { | |
1357 | case SSHMUX_COMMAND_ALIVE_CHECK: | |
1358 | fprintf(stderr, "Master running (pid=%d)\r\n", | |
1359 | control_server_pid); | |
1360 | exit(0); | |
1361 | case SSHMUX_COMMAND_TERMINATE: | |
1362 | fprintf(stderr, "Exit request sent.\r\n"); | |
1363 | exit(0); | |
1364 | case SSHMUX_COMMAND_OPEN: | |
1365 | /* continue below */ | |
1366 | break; | |
1367 | default: | |
1368 | fatal("silly mux_command %d", mux_command); | |
1369 | } | |
1370 | ||
1371 | /* SSHMUX_COMMAND_OPEN */ | |
1372 | buffer_put_cstring(&m, term ? term : ""); | |
1373 | buffer_append(&command, "\0", 1); | |
1374 | buffer_put_cstring(&m, buffer_ptr(&command)); | |
1375 | ||
1376 | if (options.num_send_env == 0 || environ == NULL) { | |
1377 | buffer_put_int(&m, 0); | |
1378 | } else { | |
1379 | /* Pass environment */ | |
1380 | num_env = 0; | |
1381 | for (i = 0; environ[i] != NULL; i++) | |
1382 | if (env_permitted(environ[i])) | |
1383 | num_env++; /* Count */ | |
1384 | ||
1385 | buffer_put_int(&m, num_env); | |
1386 | ||
1387 | for (i = 0; environ[i] != NULL && num_env >= 0; i++) | |
1388 | if (env_permitted(environ[i])) { | |
1389 | num_env--; | |
1390 | buffer_put_cstring(&m, environ[i]); | |
1391 | } | |
1392 | } | |
1393 | ||
1394 | if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) | |
1395 | fatal("%s: msg_send", __func__); | |
1396 | ||
1397 | mm_send_fd(sock, STDIN_FILENO); | |
1398 | mm_send_fd(sock, STDOUT_FILENO); | |
1399 | mm_send_fd(sock, STDERR_FILENO); | |
1400 | ||
1401 | /* Wait for reply, so master has a chance to gather ttymodes */ | |
1402 | buffer_clear(&m); | |
1403 | if (ssh_msg_recv(sock, &m) == -1) | |
1404 | fatal("%s: msg_recv", __func__); | |
1405 | if (buffer_get_char(&m) != SSHMUX_VER) | |
1406 | fatal("%s: wrong version", __func__); | |
1407 | buffer_free(&m); | |
1408 | ||
1409 | signal(SIGHUP, control_client_sighandler); | |
1410 | signal(SIGINT, control_client_sighandler); | |
1411 | signal(SIGTERM, control_client_sighandler); | |
1412 | signal(SIGWINCH, control_client_sigrelay); | |
1413 | ||
1414 | if (tty_flag) | |
1415 | enter_raw_mode(); | |
1416 | ||
1417 | /* Stick around until the controlee closes the client_fd */ | |
1418 | exitval = 0; | |
1419 | for (;!control_client_terminate;) { | |
1420 | r = read(sock, &exitval, sizeof(exitval)); | |
1421 | if (r == 0) { | |
1422 | debug2("Received EOF from master"); | |
1423 | break; | |
1424 | } | |
1425 | if (r > 0) | |
1426 | debug2("Received exit status from master %d", exitval); | |
1427 | if (r == -1 && errno != EINTR) | |
1428 | fatal("%s: read %s", __func__, strerror(errno)); | |
1429 | } | |
1430 | ||
1431 | if (control_client_terminate) | |
1432 | debug2("Exiting on signal %d", control_client_terminate); | |
1433 | ||
1434 | close(sock); | |
1435 | ||
1436 | leave_raw_mode(); | |
1437 | ||
1438 | if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET) | |
1439 | fprintf(stderr, "Connection to master closed.\r\n"); | |
1440 | ||
1441 | exit(exitval); | |
1442 | } |