1 /* $OpenBSD: ssh.c,v 1.566 2021/08/08 08:49:09 dtucker Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * Ssh client program. This program can be used to log into a remote machine. 7 * The software supports strong authentication, encryption, and forwarding 8 * of X11, TCP/IP, and authentication connections. 9 * 10 * As far as I am concerned, the code I have written for this software 11 * can be used freely for any purpose. Any derived versions of this 12 * software must be clearly marked as such, and if the derived work is 13 * incompatible with the protocol description in the RFC file, it must be 14 * called by a name other than "ssh" or "Secure Shell". 15 * 16 * Copyright (c) 1999 Niels Provos. All rights reserved. 17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved. 18 * 19 * Modified to work with SSLeay by Niels Provos <provos@citi.umich.edu> 20 * in Canada (German citizen). 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the above copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 41 */ 42 43 #include "includes.h" 44 __RCSID("$FreeBSD$"); 45 46 #include <sys/types.h> 47 #ifdef HAVE_SYS_STAT_H 48 # include <sys/stat.h> 49 #endif 50 #include <sys/resource.h> 51 #include <sys/ioctl.h> 52 #include <sys/socket.h> 53 #include <sys/wait.h> 54 55 #include <ctype.h> 56 #include <errno.h> 57 #include <fcntl.h> 58 #include <netdb.h> 59 #ifdef HAVE_PATHS_H 60 #include <paths.h> 61 #endif 62 #include <pwd.h> 63 #include <signal.h> 64 #include <stdarg.h> 65 #include <stddef.h> 66 #include <stdio.h> 67 #include <stdlib.h> 68 #include <string.h> 69 #include <stdarg.h> 70 #include <unistd.h> 71 #include <limits.h> 72 #include <locale.h> 73 74 #include <netinet/in.h> 75 #include <arpa/inet.h> 76 77 #ifdef WITH_OPENSSL 78 #include <openssl/evp.h> 79 #include <openssl/err.h> 80 #endif 81 #include "openbsd-compat/openssl-compat.h" 82 #include "openbsd-compat/sys-queue.h" 83 84 #include "xmalloc.h" 85 #include "ssh.h" 86 #include "ssh2.h" 87 #include "canohost.h" 88 #include "compat.h" 89 #include "cipher.h" 90 #include "packet.h" 91 #include "sshbuf.h" 92 #include "channels.h" 93 #include "sshkey.h" 94 #include "authfd.h" 95 #include "authfile.h" 96 #include "pathnames.h" 97 #include "dispatch.h" 98 #include "clientloop.h" 99 #include "log.h" 100 #include "misc.h" 101 #include "readconf.h" 102 #include "sshconnect.h" 103 #include "kex.h" 104 #include "mac.h" 105 #include "sshpty.h" 106 #include "match.h" 107 #include "msg.h" 108 #include "version.h" 109 #include "ssherr.h" 110 #include "myproposal.h" 111 #include "utf8.h" 112 113 #ifdef ENABLE_PKCS11 114 #include "ssh-pkcs11.h" 115 #endif 116 117 extern char *__progname; 118 119 /* Saves a copy of argv for setproctitle emulation */ 120 #ifndef HAVE_SETPROCTITLE 121 static char **saved_av; 122 #endif 123 124 /* Flag indicating whether debug mode is on. May be set on the command line. */ 125 int debug_flag = 0; 126 127 /* Flag indicating whether a tty should be requested */ 128 int tty_flag = 0; 129 130 /* 131 * Flag indicating that the current process should be backgrounded and 132 * a new mux-client launched in the foreground for ControlPersist. 133 */ 134 int need_controlpersist_detach = 0; 135 136 /* Copies of flags for ControlPersist foreground mux-client */ 137 int ostdin_null_flag, osession_type, otty_flag, orequest_tty; 138 139 /* 140 * General data structure for command line options and options configurable 141 * in configuration files. See readconf.h. 142 */ 143 Options options; 144 145 /* optional user configfile */ 146 char *config = NULL; 147 148 /* 149 * Name of the host we are connecting to. This is the name given on the 150 * command line, or the Hostname specified for the user-supplied name in a 151 * configuration file. 152 */ 153 char *host; 154 155 /* 156 * A config can specify a path to forward, overriding SSH_AUTH_SOCK. If this is 157 * not NULL, forward the socket at this path instead. 158 */ 159 char *forward_agent_sock_path = NULL; 160 161 /* socket address the host resolves to */ 162 struct sockaddr_storage hostaddr; 163 164 /* Private host keys. */ 165 Sensitive sensitive_data; 166 167 /* command to be executed */ 168 struct sshbuf *command; 169 170 /* # of replies received for global requests */ 171 static int forward_confirms_pending = -1; 172 173 /* mux.c */ 174 extern int muxserver_sock; 175 extern u_int muxclient_command; 176 177 /* Prints a help message to the user. This function never returns. */ 178 179 static void 180 usage(void) 181 { 182 fprintf(stderr, 183 "usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]\n" 184 " [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]\n" 185 " [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]\n" 186 " [-i identity_file] [-J [user@]host[:port]] [-L address]\n" 187 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" 188 " [-Q query_option] [-R address] [-S ctl_path] [-W host:port]\n" 189 " [-w local_tun[:remote_tun]] destination [command]\n" 190 ); 191 exit(255); 192 } 193 194 static int ssh_session2(struct ssh *, const struct ssh_conn_info *); 195 static void load_public_identity_files(const struct ssh_conn_info *); 196 static void main_sigchld_handler(int); 197 198 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 199 static void 200 tilde_expand_paths(char **paths, u_int num_paths) 201 { 202 u_int i; 203 char *cp; 204 205 for (i = 0; i < num_paths; i++) { 206 cp = tilde_expand_filename(paths[i], getuid()); 207 free(paths[i]); 208 paths[i] = cp; 209 } 210 } 211 212 /* 213 * Expands the set of percent_expand options used by the majority of keywords 214 * in the client that support percent expansion. 215 * Caller must free returned string. 216 */ 217 static char * 218 default_client_percent_expand(const char *str, 219 const struct ssh_conn_info *cinfo) 220 { 221 return percent_expand(str, 222 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo), 223 (char *)NULL); 224 } 225 226 /* 227 * Expands the set of percent_expand options used by the majority of keywords 228 * AND perform environment variable substitution. 229 * Caller must free returned string. 230 */ 231 static char * 232 default_client_percent_dollar_expand(const char *str, 233 const struct ssh_conn_info *cinfo) 234 { 235 char *ret; 236 237 ret = percent_dollar_expand(str, 238 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo), 239 (char *)NULL); 240 if (ret == NULL) 241 fatal("invalid environment variable expansion"); 242 return ret; 243 } 244 245 /* 246 * Attempt to resolve a host name / port to a set of addresses and 247 * optionally return any CNAMEs encountered along the way. 248 * Returns NULL on failure. 249 * NB. this function must operate with a options having undefined members. 250 */ 251 static struct addrinfo * 252 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen) 253 { 254 char strport[NI_MAXSERV]; 255 struct addrinfo hints, *res; 256 int gaierr; 257 LogLevel loglevel = SYSLOG_LEVEL_DEBUG1; 258 259 if (port <= 0) 260 port = default_ssh_port(); 261 if (cname != NULL) 262 *cname = '\0'; 263 264 snprintf(strport, sizeof strport, "%d", port); 265 memset(&hints, 0, sizeof(hints)); 266 hints.ai_family = options.address_family == -1 ? 267 AF_UNSPEC : options.address_family; 268 hints.ai_socktype = SOCK_STREAM; 269 if (cname != NULL) 270 hints.ai_flags = AI_CANONNAME; 271 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 272 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) 273 loglevel = SYSLOG_LEVEL_ERROR; 274 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", 275 __progname, name, ssh_gai_strerror(gaierr)); 276 return NULL; 277 } 278 if (cname != NULL && res->ai_canonname != NULL) { 279 if (strlcpy(cname, res->ai_canonname, clen) >= clen) { 280 error_f("host \"%s\" cname \"%s\" too long (max %lu)", 281 name, res->ai_canonname, (u_long)clen); 282 if (clen > 0) 283 *cname = '\0'; 284 } 285 } 286 return res; 287 } 288 289 /* Returns non-zero if name can only be an address and not a hostname */ 290 static int 291 is_addr_fast(const char *name) 292 { 293 return (strchr(name, '%') != NULL || strchr(name, ':') != NULL || 294 strspn(name, "0123456789.") == strlen(name)); 295 } 296 297 /* Returns non-zero if name represents a valid, single address */ 298 static int 299 is_addr(const char *name) 300 { 301 char strport[NI_MAXSERV]; 302 struct addrinfo hints, *res; 303 304 if (is_addr_fast(name)) 305 return 1; 306 307 snprintf(strport, sizeof strport, "%u", default_ssh_port()); 308 memset(&hints, 0, sizeof(hints)); 309 hints.ai_family = options.address_family == -1 ? 310 AF_UNSPEC : options.address_family; 311 hints.ai_socktype = SOCK_STREAM; 312 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 313 if (getaddrinfo(name, strport, &hints, &res) != 0) 314 return 0; 315 if (res == NULL || res->ai_next != NULL) { 316 freeaddrinfo(res); 317 return 0; 318 } 319 freeaddrinfo(res); 320 return 1; 321 } 322 323 /* 324 * Attempt to resolve a numeric host address / port to a single address. 325 * Returns a canonical address string. 326 * Returns NULL on failure. 327 * NB. this function must operate with a options having undefined members. 328 */ 329 static struct addrinfo * 330 resolve_addr(const char *name, int port, char *caddr, size_t clen) 331 { 332 char addr[NI_MAXHOST], strport[NI_MAXSERV]; 333 struct addrinfo hints, *res; 334 int gaierr; 335 336 if (port <= 0) 337 port = default_ssh_port(); 338 snprintf(strport, sizeof strport, "%u", port); 339 memset(&hints, 0, sizeof(hints)); 340 hints.ai_family = options.address_family == -1 ? 341 AF_UNSPEC : options.address_family; 342 hints.ai_socktype = SOCK_STREAM; 343 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 344 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 345 debug2_f("could not resolve name %.100s as address: %s", 346 name, ssh_gai_strerror(gaierr)); 347 return NULL; 348 } 349 if (res == NULL) { 350 debug_f("getaddrinfo %.100s returned no addresses", name); 351 return NULL; 352 } 353 if (res->ai_next != NULL) { 354 debug_f("getaddrinfo %.100s returned multiple addresses", name); 355 goto fail; 356 } 357 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen, 358 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) { 359 debug_f("Could not format address for name %.100s: %s", 360 name, ssh_gai_strerror(gaierr)); 361 goto fail; 362 } 363 if (strlcpy(caddr, addr, clen) >= clen) { 364 error_f("host \"%s\" addr \"%s\" too long (max %lu)", 365 name, addr, (u_long)clen); 366 if (clen > 0) 367 *caddr = '\0'; 368 fail: 369 freeaddrinfo(res); 370 return NULL; 371 } 372 return res; 373 } 374 375 /* 376 * Check whether the cname is a permitted replacement for the hostname 377 * and perform the replacement if it is. 378 * NB. this function must operate with a options having undefined members. 379 */ 380 static int 381 check_follow_cname(int direct, char **namep, const char *cname) 382 { 383 int i; 384 struct allowed_cname *rule; 385 386 if (*cname == '\0' || options.num_permitted_cnames == 0 || 387 strcmp(*namep, cname) == 0) 388 return 0; 389 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 390 return 0; 391 /* 392 * Don't attempt to canonicalize names that will be interpreted by 393 * a proxy or jump host unless the user specifically requests so. 394 */ 395 if (!direct && 396 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 397 return 0; 398 debug3_f("check \"%s\" CNAME \"%s\"", *namep, cname); 399 for (i = 0; i < options.num_permitted_cnames; i++) { 400 rule = options.permitted_cnames + i; 401 if (match_pattern_list(*namep, rule->source_list, 1) != 1 || 402 match_pattern_list(cname, rule->target_list, 1) != 1) 403 continue; 404 verbose("Canonicalized DNS aliased hostname " 405 "\"%s\" => \"%s\"", *namep, cname); 406 free(*namep); 407 *namep = xstrdup(cname); 408 return 1; 409 } 410 return 0; 411 } 412 413 /* 414 * Attempt to resolve the supplied hostname after applying the user's 415 * canonicalization rules. Returns the address list for the host or NULL 416 * if no name was found after canonicalization. 417 * NB. this function must operate with a options having undefined members. 418 */ 419 static struct addrinfo * 420 resolve_canonicalize(char **hostp, int port) 421 { 422 int i, direct, ndots; 423 char *cp, *fullhost, newname[NI_MAXHOST]; 424 struct addrinfo *addrs; 425 426 /* 427 * Attempt to canonicalise addresses, regardless of 428 * whether hostname canonicalisation was requested 429 */ 430 if ((addrs = resolve_addr(*hostp, port, 431 newname, sizeof(newname))) != NULL) { 432 debug2_f("hostname %.100s is address", *hostp); 433 if (strcasecmp(*hostp, newname) != 0) { 434 debug2_f("canonicalised address \"%s\" => \"%s\"", 435 *hostp, newname); 436 free(*hostp); 437 *hostp = xstrdup(newname); 438 } 439 return addrs; 440 } 441 442 /* 443 * If this looks like an address but didn't parse as one, it might 444 * be an address with an invalid interface scope. Skip further 445 * attempts at canonicalisation. 446 */ 447 if (is_addr_fast(*hostp)) { 448 debug_f("hostname %.100s is an unrecognised address", *hostp); 449 return NULL; 450 } 451 452 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 453 return NULL; 454 455 /* 456 * Don't attempt to canonicalize names that will be interpreted by 457 * a proxy unless the user specifically requests so. 458 */ 459 direct = option_clear_or_none(options.proxy_command) && 460 options.jump_host == NULL; 461 if (!direct && 462 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 463 return NULL; 464 465 /* If domain name is anchored, then resolve it now */ 466 if ((*hostp)[strlen(*hostp) - 1] == '.') { 467 debug3_f("name is fully qualified"); 468 fullhost = xstrdup(*hostp); 469 if ((addrs = resolve_host(fullhost, port, 0, 470 newname, sizeof(newname))) != NULL) 471 goto found; 472 free(fullhost); 473 goto notfound; 474 } 475 476 /* Don't apply canonicalization to sufficiently-qualified hostnames */ 477 ndots = 0; 478 for (cp = *hostp; *cp != '\0'; cp++) { 479 if (*cp == '.') 480 ndots++; 481 } 482 if (ndots > options.canonicalize_max_dots) { 483 debug3_f("not canonicalizing hostname \"%s\" (max dots %d)", 484 *hostp, options.canonicalize_max_dots); 485 return NULL; 486 } 487 /* Attempt each supplied suffix */ 488 for (i = 0; i < options.num_canonical_domains; i++) { 489 if (strcasecmp(options.canonical_domains[i], "none") == 0) 490 break; 491 xasprintf(&fullhost, "%s.%s.", *hostp, 492 options.canonical_domains[i]); 493 debug3_f("attempting \"%s\" => \"%s\"", *hostp, fullhost); 494 if ((addrs = resolve_host(fullhost, port, 0, 495 newname, sizeof(newname))) == NULL) { 496 free(fullhost); 497 continue; 498 } 499 found: 500 /* Remove trailing '.' */ 501 fullhost[strlen(fullhost) - 1] = '\0'; 502 /* Follow CNAME if requested */ 503 if (!check_follow_cname(direct, &fullhost, newname)) { 504 debug("Canonicalized hostname \"%s\" => \"%s\"", 505 *hostp, fullhost); 506 } 507 free(*hostp); 508 *hostp = fullhost; 509 return addrs; 510 } 511 notfound: 512 if (!options.canonicalize_fallback_local) 513 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); 514 debug2_f("host %s not found in any suffix", *hostp); 515 return NULL; 516 } 517 518 /* 519 * Check the result of hostkey loading, ignoring some errors and 520 * fatal()ing for others. 521 */ 522 static void 523 check_load(int r, const char *path, const char *message) 524 { 525 switch (r) { 526 case 0: 527 break; 528 case SSH_ERR_INTERNAL_ERROR: 529 case SSH_ERR_ALLOC_FAIL: 530 fatal_r(r, "load %s \"%s\"", message, path); 531 case SSH_ERR_SYSTEM_ERROR: 532 /* Ignore missing files */ 533 if (errno == ENOENT) 534 break; 535 /* FALLTHROUGH */ 536 default: 537 error_r(r, "load %s \"%s\"", message, path); 538 break; 539 } 540 } 541 542 /* 543 * Read per-user configuration file. Ignore the system wide config 544 * file if the user specifies a config file on the command line. 545 */ 546 static void 547 process_config_files(const char *host_name, struct passwd *pw, int final_pass, 548 int *want_final_pass) 549 { 550 char buf[PATH_MAX]; 551 int r; 552 553 if (config != NULL) { 554 if (strcasecmp(config, "none") != 0 && 555 !read_config_file(config, pw, host, host_name, &options, 556 SSHCONF_USERCONF | (final_pass ? SSHCONF_FINAL : 0), 557 want_final_pass)) 558 fatal("Can't open user config file %.100s: " 559 "%.100s", config, strerror(errno)); 560 } else { 561 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 562 _PATH_SSH_USER_CONFFILE); 563 if (r > 0 && (size_t)r < sizeof(buf)) 564 (void)read_config_file(buf, pw, host, host_name, 565 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF | 566 (final_pass ? SSHCONF_FINAL : 0), want_final_pass); 567 568 /* Read systemwide configuration file after user config. */ 569 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, 570 host, host_name, &options, 571 final_pass ? SSHCONF_FINAL : 0, want_final_pass); 572 } 573 } 574 575 /* Rewrite the port number in an addrinfo list of addresses */ 576 static void 577 set_addrinfo_port(struct addrinfo *addrs, int port) 578 { 579 struct addrinfo *addr; 580 581 for (addr = addrs; addr != NULL; addr = addr->ai_next) { 582 switch (addr->ai_family) { 583 case AF_INET: 584 ((struct sockaddr_in *)addr->ai_addr)-> 585 sin_port = htons(port); 586 break; 587 case AF_INET6: 588 ((struct sockaddr_in6 *)addr->ai_addr)-> 589 sin6_port = htons(port); 590 break; 591 } 592 } 593 } 594 595 static void 596 ssh_conn_info_free(struct ssh_conn_info *cinfo) 597 { 598 if (cinfo == NULL) 599 return; 600 free(cinfo->conn_hash_hex); 601 free(cinfo->shorthost); 602 free(cinfo->uidstr); 603 free(cinfo->keyalias); 604 free(cinfo->thishost); 605 free(cinfo->host_arg); 606 free(cinfo->portstr); 607 free(cinfo->remhost); 608 free(cinfo->remuser); 609 free(cinfo->homedir); 610 free(cinfo->locuser); 611 free(cinfo); 612 } 613 614 /* 615 * Main program for the ssh client. 616 */ 617 int 618 main(int ac, char **av) 619 { 620 struct ssh *ssh = NULL; 621 int i, r, opt, exit_status, use_syslog, direct, timeout_ms; 622 int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0; 623 char *p, *cp, *line, *argv0, *logfile, *host_arg; 624 char cname[NI_MAXHOST], thishost[NI_MAXHOST]; 625 struct stat st; 626 struct passwd *pw; 627 extern int optind, optreset; 628 extern char *optarg; 629 struct Forward fwd; 630 struct addrinfo *addrs = NULL; 631 size_t n, len; 632 u_int j; 633 struct ssh_conn_info *cinfo = NULL; 634 635 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 636 sanitise_stdfd(); 637 638 /* 639 * Discard other fds that are hanging around. These can cause problem 640 * with backgrounded ssh processes started by ControlPersist. 641 */ 642 closefrom(STDERR_FILENO + 1); 643 644 __progname = ssh_get_progname(av[0]); 645 646 #ifndef HAVE_SETPROCTITLE 647 /* Prepare for later setproctitle emulation */ 648 /* Save argv so it isn't clobbered by setproctitle() emulation */ 649 saved_av = xcalloc(ac + 1, sizeof(*saved_av)); 650 for (i = 0; i < ac; i++) 651 saved_av[i] = xstrdup(av[i]); 652 saved_av[i] = NULL; 653 compat_init_setproctitle(ac, av); 654 av = saved_av; 655 #endif 656 657 seed_rng(); 658 659 /* Get user data. */ 660 pw = getpwuid(getuid()); 661 if (!pw) { 662 logit("No user exists for uid %lu", (u_long)getuid()); 663 exit(255); 664 } 665 /* Take a copy of the returned structure. */ 666 pw = pwcopy(pw); 667 668 /* 669 * Set our umask to something reasonable, as some files are created 670 * with the default umask. This will make them world-readable but 671 * writable only by the owner, which is ok for all files for which we 672 * don't set the modes explicitly. 673 */ 674 umask(022); 675 676 msetlocale(); 677 678 /* 679 * Initialize option structure to indicate that no values have been 680 * set. 681 */ 682 initialize_options(&options); 683 684 /* 685 * Prepare main ssh transport/connection structures 686 */ 687 if ((ssh = ssh_alloc_session_state()) == NULL) 688 fatal("Couldn't allocate session state"); 689 channel_init_channels(ssh); 690 691 /* Parse command-line arguments. */ 692 host = NULL; 693 use_syslog = 0; 694 logfile = NULL; 695 argv0 = av[0]; 696 697 again: 698 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 699 "AB:CD:E:F:GI:J:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { 700 switch (opt) { 701 case '1': 702 fatal("SSH protocol v.1 is no longer supported"); 703 break; 704 case '2': 705 /* Ignored */ 706 break; 707 case '4': 708 options.address_family = AF_INET; 709 break; 710 case '6': 711 options.address_family = AF_INET6; 712 break; 713 case 'n': 714 options.stdin_null = 1; 715 break; 716 case 'f': 717 options.fork_after_authentication = 1; 718 options.stdin_null = 1; 719 break; 720 case 'x': 721 options.forward_x11 = 0; 722 break; 723 case 'X': 724 options.forward_x11 = 1; 725 break; 726 case 'y': 727 use_syslog = 1; 728 break; 729 case 'E': 730 logfile = optarg; 731 break; 732 case 'G': 733 config_test = 1; 734 break; 735 case 'Y': 736 options.forward_x11 = 1; 737 options.forward_x11_trusted = 1; 738 break; 739 case 'g': 740 options.fwd_opts.gateway_ports = 1; 741 break; 742 case 'O': 743 if (options.stdio_forward_host != NULL) 744 fatal("Cannot specify multiplexing " 745 "command with -W"); 746 else if (muxclient_command != 0) 747 fatal("Multiplexing command already specified"); 748 if (strcmp(optarg, "check") == 0) 749 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 750 else if (strcmp(optarg, "forward") == 0) 751 muxclient_command = SSHMUX_COMMAND_FORWARD; 752 else if (strcmp(optarg, "exit") == 0) 753 muxclient_command = SSHMUX_COMMAND_TERMINATE; 754 else if (strcmp(optarg, "stop") == 0) 755 muxclient_command = SSHMUX_COMMAND_STOP; 756 else if (strcmp(optarg, "cancel") == 0) 757 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 758 else if (strcmp(optarg, "proxy") == 0) 759 muxclient_command = SSHMUX_COMMAND_PROXY; 760 else 761 fatal("Invalid multiplex command."); 762 break; 763 case 'P': /* deprecated */ 764 break; 765 case 'Q': 766 cp = NULL; 767 if (strcmp(optarg, "cipher") == 0 || 768 strcasecmp(optarg, "Ciphers") == 0) 769 cp = cipher_alg_list('\n', 0); 770 else if (strcmp(optarg, "cipher-auth") == 0) 771 cp = cipher_alg_list('\n', 1); 772 else if (strcmp(optarg, "mac") == 0 || 773 strcasecmp(optarg, "MACs") == 0) 774 cp = mac_alg_list('\n'); 775 else if (strcmp(optarg, "kex") == 0 || 776 strcasecmp(optarg, "KexAlgorithms") == 0) 777 cp = kex_alg_list('\n'); 778 else if (strcmp(optarg, "key") == 0) 779 cp = sshkey_alg_list(0, 0, 0, '\n'); 780 else if (strcmp(optarg, "key-cert") == 0) 781 cp = sshkey_alg_list(1, 0, 0, '\n'); 782 else if (strcmp(optarg, "key-plain") == 0) 783 cp = sshkey_alg_list(0, 1, 0, '\n'); 784 else if (strcmp(optarg, "key-sig") == 0 || 785 strcasecmp(optarg, "PubkeyAcceptedKeyTypes") == 0 || /* deprecated name */ 786 strcasecmp(optarg, "PubkeyAcceptedAlgorithms") == 0 || 787 strcasecmp(optarg, "HostKeyAlgorithms") == 0 || 788 strcasecmp(optarg, "HostbasedKeyTypes") == 0 || /* deprecated name */ 789 strcasecmp(optarg, "HostbasedAcceptedKeyTypes") == 0 || /* deprecated name */ 790 strcasecmp(optarg, "HostbasedAcceptedAlgorithms") == 0) 791 cp = sshkey_alg_list(0, 0, 1, '\n'); 792 else if (strcmp(optarg, "sig") == 0) 793 cp = sshkey_alg_list(0, 1, 1, '\n'); 794 else if (strcmp(optarg, "protocol-version") == 0) 795 cp = xstrdup("2"); 796 else if (strcmp(optarg, "compression") == 0) { 797 cp = xstrdup(compression_alg_list(0)); 798 len = strlen(cp); 799 for (n = 0; n < len; n++) 800 if (cp[n] == ',') 801 cp[n] = '\n'; 802 } else if (strcmp(optarg, "help") == 0) { 803 cp = xstrdup( 804 "cipher\ncipher-auth\ncompression\nkex\n" 805 "key\nkey-cert\nkey-plain\nkey-sig\nmac\n" 806 "protocol-version\nsig"); 807 } 808 if (cp == NULL) 809 fatal("Unsupported query \"%s\"", optarg); 810 printf("%s\n", cp); 811 free(cp); 812 exit(0); 813 break; 814 case 'a': 815 options.forward_agent = 0; 816 break; 817 case 'A': 818 options.forward_agent = 1; 819 break; 820 case 'k': 821 options.gss_deleg_creds = 0; 822 break; 823 case 'K': 824 options.gss_authentication = 1; 825 options.gss_deleg_creds = 1; 826 break; 827 case 'i': 828 p = tilde_expand_filename(optarg, getuid()); 829 if (stat(p, &st) == -1) 830 fprintf(stderr, "Warning: Identity file %s " 831 "not accessible: %s.\n", p, 832 strerror(errno)); 833 else 834 add_identity_file(&options, NULL, p, 1); 835 free(p); 836 break; 837 case 'I': 838 #ifdef ENABLE_PKCS11 839 free(options.pkcs11_provider); 840 options.pkcs11_provider = xstrdup(optarg); 841 #else 842 fprintf(stderr, "no support for PKCS#11.\n"); 843 #endif 844 break; 845 case 'J': 846 if (options.jump_host != NULL) { 847 fatal("Only a single -J option is permitted " 848 "(use commas to separate multiple " 849 "jump hops)"); 850 } 851 if (options.proxy_command != NULL) 852 fatal("Cannot specify -J with ProxyCommand"); 853 if (parse_jump(optarg, &options, 1) == -1) 854 fatal("Invalid -J argument"); 855 options.proxy_command = xstrdup("none"); 856 break; 857 case 't': 858 if (options.request_tty == REQUEST_TTY_YES) 859 options.request_tty = REQUEST_TTY_FORCE; 860 else 861 options.request_tty = REQUEST_TTY_YES; 862 break; 863 case 'v': 864 if (debug_flag == 0) { 865 debug_flag = 1; 866 options.log_level = SYSLOG_LEVEL_DEBUG1; 867 } else { 868 if (options.log_level < SYSLOG_LEVEL_DEBUG3) { 869 debug_flag++; 870 options.log_level++; 871 } 872 } 873 break; 874 case 'V': 875 if (options.version_addendum && 876 *options.version_addendum != '\0') 877 fprintf(stderr, "%s %s, %s\n", SSH_RELEASE, 878 options.version_addendum, 879 OPENSSL_VERSION_STRING); 880 else 881 fprintf(stderr, "%s, %s\n", SSH_RELEASE, 882 OPENSSL_VERSION_STRING); 883 if (opt == 'V') 884 exit(0); 885 break; 886 case 'w': 887 if (options.tun_open == -1) 888 options.tun_open = SSH_TUNMODE_DEFAULT; 889 options.tun_local = a2tun(optarg, &options.tun_remote); 890 if (options.tun_local == SSH_TUNID_ERR) { 891 fprintf(stderr, 892 "Bad tun device '%s'\n", optarg); 893 exit(255); 894 } 895 break; 896 case 'W': 897 if (options.stdio_forward_host != NULL) 898 fatal("stdio forward already specified"); 899 if (muxclient_command != 0) 900 fatal("Cannot specify stdio forward with -O"); 901 if (parse_forward(&fwd, optarg, 1, 0)) { 902 options.stdio_forward_host = fwd.listen_host; 903 options.stdio_forward_port = fwd.listen_port; 904 free(fwd.connect_host); 905 } else { 906 fprintf(stderr, 907 "Bad stdio forwarding specification '%s'\n", 908 optarg); 909 exit(255); 910 } 911 options.request_tty = REQUEST_TTY_NO; 912 options.session_type = SESSION_TYPE_NONE; 913 break; 914 case 'q': 915 options.log_level = SYSLOG_LEVEL_QUIET; 916 break; 917 case 'e': 918 if (optarg[0] == '^' && optarg[2] == 0 && 919 (u_char) optarg[1] >= 64 && 920 (u_char) optarg[1] < 128) 921 options.escape_char = (u_char) optarg[1] & 31; 922 else if (strlen(optarg) == 1) 923 options.escape_char = (u_char) optarg[0]; 924 else if (strcmp(optarg, "none") == 0) 925 options.escape_char = SSH_ESCAPECHAR_NONE; 926 else { 927 fprintf(stderr, "Bad escape character '%s'.\n", 928 optarg); 929 exit(255); 930 } 931 break; 932 case 'c': 933 if (!ciphers_valid(*optarg == '+' || *optarg == '^' ? 934 optarg + 1 : optarg)) { 935 fprintf(stderr, "Unknown cipher type '%s'\n", 936 optarg); 937 exit(255); 938 } 939 free(options.ciphers); 940 options.ciphers = xstrdup(optarg); 941 break; 942 case 'm': 943 if (mac_valid(optarg)) { 944 free(options.macs); 945 options.macs = xstrdup(optarg); 946 } else { 947 fprintf(stderr, "Unknown mac type '%s'\n", 948 optarg); 949 exit(255); 950 } 951 break; 952 case 'M': 953 if (options.control_master == SSHCTL_MASTER_YES) 954 options.control_master = SSHCTL_MASTER_ASK; 955 else 956 options.control_master = SSHCTL_MASTER_YES; 957 break; 958 case 'p': 959 if (options.port == -1) { 960 options.port = a2port(optarg); 961 if (options.port <= 0) { 962 fprintf(stderr, "Bad port '%s'\n", 963 optarg); 964 exit(255); 965 } 966 } 967 break; 968 case 'l': 969 if (options.user == NULL) 970 options.user = optarg; 971 break; 972 973 case 'L': 974 if (parse_forward(&fwd, optarg, 0, 0)) 975 add_local_forward(&options, &fwd); 976 else { 977 fprintf(stderr, 978 "Bad local forwarding specification '%s'\n", 979 optarg); 980 exit(255); 981 } 982 break; 983 984 case 'R': 985 if (parse_forward(&fwd, optarg, 0, 1) || 986 parse_forward(&fwd, optarg, 1, 1)) { 987 add_remote_forward(&options, &fwd); 988 } else { 989 fprintf(stderr, 990 "Bad remote forwarding specification " 991 "'%s'\n", optarg); 992 exit(255); 993 } 994 break; 995 996 case 'D': 997 if (parse_forward(&fwd, optarg, 1, 0)) { 998 add_local_forward(&options, &fwd); 999 } else { 1000 fprintf(stderr, 1001 "Bad dynamic forwarding specification " 1002 "'%s'\n", optarg); 1003 exit(255); 1004 } 1005 break; 1006 1007 case 'C': 1008 #ifdef WITH_ZLIB 1009 options.compression = 1; 1010 #else 1011 error("Compression not supported, disabling."); 1012 #endif 1013 break; 1014 case 'N': 1015 if (options.session_type != -1 && 1016 options.session_type != SESSION_TYPE_NONE) 1017 fatal("Cannot specify -N with -s/SessionType"); 1018 options.session_type = SESSION_TYPE_NONE; 1019 options.request_tty = REQUEST_TTY_NO; 1020 break; 1021 case 'T': 1022 options.request_tty = REQUEST_TTY_NO; 1023 break; 1024 case 'o': 1025 line = xstrdup(optarg); 1026 if (process_config_line(&options, pw, 1027 host ? host : "", host ? host : "", line, 1028 "command-line", 0, NULL, SSHCONF_USERCONF) != 0) 1029 exit(255); 1030 free(line); 1031 break; 1032 case 's': 1033 if (options.session_type != -1 && 1034 options.session_type != SESSION_TYPE_SUBSYSTEM) 1035 fatal("Cannot specify -s with -N/SessionType"); 1036 options.session_type = SESSION_TYPE_SUBSYSTEM; 1037 break; 1038 case 'S': 1039 free(options.control_path); 1040 options.control_path = xstrdup(optarg); 1041 break; 1042 case 'b': 1043 options.bind_address = optarg; 1044 break; 1045 case 'B': 1046 options.bind_interface = optarg; 1047 break; 1048 case 'F': 1049 config = optarg; 1050 break; 1051 default: 1052 usage(); 1053 } 1054 } 1055 1056 if (optind > 1 && strcmp(av[optind - 1], "--") == 0) 1057 opt_terminated = 1; 1058 1059 ac -= optind; 1060 av += optind; 1061 1062 if (ac > 0 && !host) { 1063 int tport; 1064 char *tuser; 1065 switch (parse_ssh_uri(*av, &tuser, &host, &tport)) { 1066 case -1: 1067 usage(); 1068 break; 1069 case 0: 1070 if (options.user == NULL) { 1071 options.user = tuser; 1072 tuser = NULL; 1073 } 1074 free(tuser); 1075 if (options.port == -1 && tport != -1) 1076 options.port = tport; 1077 break; 1078 default: 1079 p = xstrdup(*av); 1080 cp = strrchr(p, '@'); 1081 if (cp != NULL) { 1082 if (cp == p) 1083 usage(); 1084 if (options.user == NULL) { 1085 options.user = p; 1086 p = NULL; 1087 } 1088 *cp++ = '\0'; 1089 host = xstrdup(cp); 1090 free(p); 1091 } else 1092 host = p; 1093 break; 1094 } 1095 if (ac > 1 && !opt_terminated) { 1096 optind = optreset = 1; 1097 goto again; 1098 } 1099 ac--, av++; 1100 } 1101 1102 /* Check that we got a host name. */ 1103 if (!host) 1104 usage(); 1105 1106 host_arg = xstrdup(host); 1107 1108 /* Initialize the command to execute on remote host. */ 1109 if ((command = sshbuf_new()) == NULL) 1110 fatal("sshbuf_new failed"); 1111 1112 /* 1113 * Save the command to execute on the remote host in a buffer. There 1114 * is no limit on the length of the command, except by the maximum 1115 * packet size. Also sets the tty flag if there is no command. 1116 */ 1117 if (!ac) { 1118 /* No command specified - execute shell on a tty. */ 1119 if (options.session_type == SESSION_TYPE_SUBSYSTEM) { 1120 fprintf(stderr, 1121 "You must specify a subsystem to invoke.\n"); 1122 usage(); 1123 } 1124 } else { 1125 /* A command has been specified. Store it into the buffer. */ 1126 for (i = 0; i < ac; i++) { 1127 if ((r = sshbuf_putf(command, "%s%s", 1128 i ? " " : "", av[i])) != 0) 1129 fatal_fr(r, "buffer error"); 1130 } 1131 } 1132 1133 /* 1134 * Initialize "log" output. Since we are the client all output 1135 * goes to stderr unless otherwise specified by -y or -E. 1136 */ 1137 if (use_syslog && logfile != NULL) 1138 fatal("Can't specify both -y and -E"); 1139 if (logfile != NULL) 1140 log_redirect_stderr_to(logfile); 1141 log_init(argv0, 1142 options.log_level == SYSLOG_LEVEL_NOT_SET ? 1143 SYSLOG_LEVEL_INFO : options.log_level, 1144 options.log_facility == SYSLOG_FACILITY_NOT_SET ? 1145 SYSLOG_FACILITY_USER : options.log_facility, 1146 !use_syslog); 1147 1148 if (debug_flag) 1149 /* version_addendum is always NULL at this point */ 1150 logit("%s, %s", SSH_RELEASE, OPENSSL_VERSION_STRING); 1151 1152 /* Parse the configuration files */ 1153 process_config_files(host_arg, pw, 0, &want_final_pass); 1154 if (want_final_pass) 1155 debug("configuration requests final Match pass"); 1156 1157 /* Hostname canonicalisation needs a few options filled. */ 1158 fill_default_options_for_canonicalization(&options); 1159 1160 /* If the user has replaced the hostname then take it into use now */ 1161 if (options.hostname != NULL) { 1162 /* NB. Please keep in sync with readconf.c:match_cfg_line() */ 1163 cp = percent_expand(options.hostname, 1164 "h", host, (char *)NULL); 1165 free(host); 1166 host = cp; 1167 free(options.hostname); 1168 options.hostname = xstrdup(host); 1169 } 1170 1171 /* Don't lowercase addresses, they will be explicitly canonicalised */ 1172 if ((was_addr = is_addr(host)) == 0) 1173 lowercase(host); 1174 1175 /* 1176 * Try to canonicalize if requested by configuration or the 1177 * hostname is an address. 1178 */ 1179 if (options.canonicalize_hostname != SSH_CANONICALISE_NO || was_addr) 1180 addrs = resolve_canonicalize(&host, options.port); 1181 1182 /* 1183 * If CanonicalizePermittedCNAMEs have been specified but 1184 * other canonicalization did not happen (by not being requested 1185 * or by failing with fallback) then the hostname may still be changed 1186 * as a result of CNAME following. 1187 * 1188 * Try to resolve the bare hostname name using the system resolver's 1189 * usual search rules and then apply the CNAME follow rules. 1190 * 1191 * Skip the lookup if a ProxyCommand is being used unless the user 1192 * has specifically requested canonicalisation for this case via 1193 * CanonicalizeHostname=always 1194 */ 1195 direct = option_clear_or_none(options.proxy_command) && 1196 options.jump_host == NULL; 1197 if (addrs == NULL && options.num_permitted_cnames != 0 && (direct || 1198 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { 1199 if ((addrs = resolve_host(host, options.port, 1200 direct, cname, sizeof(cname))) == NULL) { 1201 /* Don't fatal proxied host names not in the DNS */ 1202 if (direct) 1203 cleanup_exit(255); /* logged in resolve_host */ 1204 } else 1205 check_follow_cname(direct, &host, cname); 1206 } 1207 1208 /* 1209 * If canonicalisation is enabled then re-parse the configuration 1210 * files as new stanzas may match. 1211 */ 1212 if (options.canonicalize_hostname != 0 && !want_final_pass) { 1213 debug("hostname canonicalisation enabled, " 1214 "will re-parse configuration"); 1215 want_final_pass = 1; 1216 } 1217 1218 if (want_final_pass) { 1219 debug("re-parsing configuration"); 1220 free(options.hostname); 1221 options.hostname = xstrdup(host); 1222 process_config_files(host_arg, pw, 1, NULL); 1223 /* 1224 * Address resolution happens early with canonicalisation 1225 * enabled and the port number may have changed since, so 1226 * reset it in address list 1227 */ 1228 if (addrs != NULL && options.port > 0) 1229 set_addrinfo_port(addrs, options.port); 1230 } 1231 1232 /* Fill configuration defaults. */ 1233 if (fill_default_options(&options) != 0) 1234 cleanup_exit(255); 1235 1236 if (options.user == NULL) 1237 options.user = xstrdup(pw->pw_name); 1238 1239 /* 1240 * If ProxyJump option specified, then construct a ProxyCommand now. 1241 */ 1242 if (options.jump_host != NULL) { 1243 char port_s[8]; 1244 const char *jumpuser = options.jump_user, *sshbin = argv0; 1245 int port = options.port, jumpport = options.jump_port; 1246 1247 if (port <= 0) 1248 port = default_ssh_port(); 1249 if (jumpport <= 0) 1250 jumpport = default_ssh_port(); 1251 if (jumpuser == NULL) 1252 jumpuser = options.user; 1253 if (strcmp(options.jump_host, host) == 0 && port == jumpport && 1254 strcmp(options.user, jumpuser) == 0) 1255 fatal("jumphost loop via %s", options.jump_host); 1256 1257 /* 1258 * Try to use SSH indicated by argv[0], but fall back to 1259 * "ssh" if it appears unavailable. 1260 */ 1261 if (strchr(argv0, '/') != NULL && access(argv0, X_OK) != 0) 1262 sshbin = "ssh"; 1263 1264 /* Consistency check */ 1265 if (options.proxy_command != NULL) 1266 fatal("inconsistent options: ProxyCommand+ProxyJump"); 1267 /* Never use FD passing for ProxyJump */ 1268 options.proxy_use_fdpass = 0; 1269 snprintf(port_s, sizeof(port_s), "%d", options.jump_port); 1270 xasprintf(&options.proxy_command, 1271 "%s%s%s%s%s%s%s%s%s%s%.*s -W '[%%h]:%%p' %s", 1272 sshbin, 1273 /* Optional "-l user" argument if jump_user set */ 1274 options.jump_user == NULL ? "" : " -l ", 1275 options.jump_user == NULL ? "" : options.jump_user, 1276 /* Optional "-p port" argument if jump_port set */ 1277 options.jump_port <= 0 ? "" : " -p ", 1278 options.jump_port <= 0 ? "" : port_s, 1279 /* Optional additional jump hosts ",..." */ 1280 options.jump_extra == NULL ? "" : " -J ", 1281 options.jump_extra == NULL ? "" : options.jump_extra, 1282 /* Optional "-F" argumment if -F specified */ 1283 config == NULL ? "" : " -F ", 1284 config == NULL ? "" : config, 1285 /* Optional "-v" arguments if -v set */ 1286 debug_flag ? " -" : "", 1287 debug_flag, "vvv", 1288 /* Mandatory hostname */ 1289 options.jump_host); 1290 debug("Setting implicit ProxyCommand from ProxyJump: %s", 1291 options.proxy_command); 1292 } 1293 1294 if (options.port == 0) 1295 options.port = default_ssh_port(); 1296 channel_set_af(ssh, options.address_family); 1297 1298 /* Tidy and check options */ 1299 if (options.host_key_alias != NULL) 1300 lowercase(options.host_key_alias); 1301 if (options.proxy_command != NULL && 1302 strcmp(options.proxy_command, "-") == 0 && 1303 options.proxy_use_fdpass) 1304 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); 1305 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 1306 if (options.control_persist && options.control_path != NULL) { 1307 debug("UpdateHostKeys=ask is incompatible with " 1308 "ControlPersist; disabling"); 1309 options.update_hostkeys = 0; 1310 } else if (sshbuf_len(command) != 0 || 1311 options.remote_command != NULL || 1312 options.request_tty == REQUEST_TTY_NO) { 1313 debug("UpdateHostKeys=ask is incompatible with " 1314 "remote command execution; disabling"); 1315 options.update_hostkeys = 0; 1316 } else if (options.log_level < SYSLOG_LEVEL_INFO) { 1317 /* no point logging anything; user won't see it */ 1318 options.update_hostkeys = 0; 1319 } 1320 } 1321 if (options.connection_attempts <= 0) 1322 fatal("Invalid number of ConnectionAttempts"); 1323 1324 if (sshbuf_len(command) != 0 && options.remote_command != NULL) 1325 fatal("Cannot execute command-line and remote command."); 1326 1327 /* Cannot fork to background if no command. */ 1328 if (options.fork_after_authentication && sshbuf_len(command) == 0 && 1329 options.remote_command == NULL && 1330 options.session_type != SESSION_TYPE_NONE) 1331 fatal("Cannot fork into background without a command " 1332 "to execute."); 1333 1334 /* reinit */ 1335 log_init(argv0, options.log_level, options.log_facility, !use_syslog); 1336 for (j = 0; j < options.num_log_verbose; j++) { 1337 if (strcasecmp(options.log_verbose[j], "none") == 0) 1338 break; 1339 log_verbose_add(options.log_verbose[j]); 1340 } 1341 1342 if (options.request_tty == REQUEST_TTY_YES || 1343 options.request_tty == REQUEST_TTY_FORCE) 1344 tty_flag = 1; 1345 1346 /* Allocate a tty by default if no command specified. */ 1347 if (sshbuf_len(command) == 0 && options.remote_command == NULL) 1348 tty_flag = options.request_tty != REQUEST_TTY_NO; 1349 1350 /* Force no tty */ 1351 if (options.request_tty == REQUEST_TTY_NO || 1352 (muxclient_command && muxclient_command != SSHMUX_COMMAND_PROXY)) 1353 tty_flag = 0; 1354 /* Do not allocate a tty if stdin is not a tty. */ 1355 if ((!isatty(fileno(stdin)) || options.stdin_null) && 1356 options.request_tty != REQUEST_TTY_FORCE) { 1357 if (tty_flag) 1358 logit("Pseudo-terminal will not be allocated because " 1359 "stdin is not a terminal."); 1360 tty_flag = 0; 1361 } 1362 1363 /* Set up strings used to percent_expand() arguments */ 1364 cinfo = xcalloc(1, sizeof(*cinfo)); 1365 if (gethostname(thishost, sizeof(thishost)) == -1) 1366 fatal("gethostname: %s", strerror(errno)); 1367 cinfo->thishost = xstrdup(thishost); 1368 thishost[strcspn(thishost, ".")] = '\0'; 1369 cinfo->shorthost = xstrdup(thishost); 1370 xasprintf(&cinfo->portstr, "%d", options.port); 1371 xasprintf(&cinfo->uidstr, "%llu", 1372 (unsigned long long)pw->pw_uid); 1373 cinfo->keyalias = xstrdup(options.host_key_alias ? 1374 options.host_key_alias : host_arg); 1375 cinfo->conn_hash_hex = ssh_connection_hash(cinfo->thishost, host, 1376 cinfo->portstr, options.user); 1377 cinfo->host_arg = xstrdup(host_arg); 1378 cinfo->remhost = xstrdup(host); 1379 cinfo->remuser = xstrdup(options.user); 1380 cinfo->homedir = xstrdup(pw->pw_dir); 1381 cinfo->locuser = xstrdup(pw->pw_name); 1382 1383 /* Find canonic host name. */ 1384 if (strchr(host, '.') == 0) { 1385 struct addrinfo hints; 1386 struct addrinfo *ai = NULL; 1387 int errgai; 1388 memset(&hints, 0, sizeof(hints)); 1389 hints.ai_family = options.address_family; 1390 hints.ai_flags = AI_CANONNAME; 1391 hints.ai_socktype = SOCK_STREAM; 1392 errgai = getaddrinfo(host, NULL, &hints, &ai); 1393 if (errgai == 0) { 1394 if (ai->ai_canonname != NULL) 1395 host = xstrdup(ai->ai_canonname); 1396 freeaddrinfo(ai); 1397 } 1398 } 1399 1400 /* 1401 * Expand tokens in arguments. NB. LocalCommand is expanded later, 1402 * after port-forwarding is set up, so it may pick up any local 1403 * tunnel interface name allocated. 1404 */ 1405 if (options.remote_command != NULL) { 1406 debug3("expanding RemoteCommand: %s", options.remote_command); 1407 cp = options.remote_command; 1408 options.remote_command = default_client_percent_expand(cp, 1409 cinfo); 1410 debug3("expanded RemoteCommand: %s", options.remote_command); 1411 free(cp); 1412 if ((r = sshbuf_put(command, options.remote_command, 1413 strlen(options.remote_command))) != 0) 1414 fatal_fr(r, "buffer error"); 1415 } 1416 1417 if (options.control_path != NULL) { 1418 cp = tilde_expand_filename(options.control_path, getuid()); 1419 free(options.control_path); 1420 options.control_path = default_client_percent_dollar_expand(cp, 1421 cinfo); 1422 free(cp); 1423 } 1424 1425 if (options.identity_agent != NULL) { 1426 p = tilde_expand_filename(options.identity_agent, getuid()); 1427 cp = default_client_percent_dollar_expand(p, cinfo); 1428 free(p); 1429 free(options.identity_agent); 1430 options.identity_agent = cp; 1431 } 1432 1433 if (options.forward_agent_sock_path != NULL) { 1434 p = tilde_expand_filename(options.forward_agent_sock_path, 1435 getuid()); 1436 cp = default_client_percent_dollar_expand(p, cinfo); 1437 free(p); 1438 free(options.forward_agent_sock_path); 1439 options.forward_agent_sock_path = cp; 1440 if (stat(options.forward_agent_sock_path, &st) != 0) { 1441 error("Cannot forward agent socket path \"%s\": %s", 1442 options.forward_agent_sock_path, strerror(errno)); 1443 if (options.exit_on_forward_failure) 1444 cleanup_exit(255); 1445 } 1446 } 1447 1448 if (options.num_system_hostfiles > 0 && 1449 strcasecmp(options.system_hostfiles[0], "none") == 0) { 1450 if (options.num_system_hostfiles > 1) 1451 fatal("Invalid GlobalKnownHostsFiles: \"none\" " 1452 "appears with other entries"); 1453 free(options.system_hostfiles[0]); 1454 options.system_hostfiles[0] = NULL; 1455 options.num_system_hostfiles = 0; 1456 } 1457 1458 if (options.num_user_hostfiles > 0 && 1459 strcasecmp(options.user_hostfiles[0], "none") == 0) { 1460 if (options.num_user_hostfiles > 1) 1461 fatal("Invalid UserKnownHostsFiles: \"none\" " 1462 "appears with other entries"); 1463 free(options.user_hostfiles[0]); 1464 options.user_hostfiles[0] = NULL; 1465 options.num_user_hostfiles = 0; 1466 } 1467 for (j = 0; j < options.num_user_hostfiles; j++) { 1468 if (options.user_hostfiles[j] == NULL) 1469 continue; 1470 cp = tilde_expand_filename(options.user_hostfiles[j], getuid()); 1471 p = default_client_percent_dollar_expand(cp, cinfo); 1472 if (strcmp(options.user_hostfiles[j], p) != 0) 1473 debug3("expanded UserKnownHostsFile '%s' -> " 1474 "'%s'", options.user_hostfiles[j], p); 1475 free(options.user_hostfiles[j]); 1476 free(cp); 1477 options.user_hostfiles[j] = p; 1478 } 1479 1480 for (i = 0; i < options.num_local_forwards; i++) { 1481 if (options.local_forwards[i].listen_path != NULL) { 1482 cp = options.local_forwards[i].listen_path; 1483 p = options.local_forwards[i].listen_path = 1484 default_client_percent_expand(cp, cinfo); 1485 if (strcmp(cp, p) != 0) 1486 debug3("expanded LocalForward listen path " 1487 "'%s' -> '%s'", cp, p); 1488 free(cp); 1489 } 1490 if (options.local_forwards[i].connect_path != NULL) { 1491 cp = options.local_forwards[i].connect_path; 1492 p = options.local_forwards[i].connect_path = 1493 default_client_percent_expand(cp, cinfo); 1494 if (strcmp(cp, p) != 0) 1495 debug3("expanded LocalForward connect path " 1496 "'%s' -> '%s'", cp, p); 1497 free(cp); 1498 } 1499 } 1500 1501 for (i = 0; i < options.num_remote_forwards; i++) { 1502 if (options.remote_forwards[i].listen_path != NULL) { 1503 cp = options.remote_forwards[i].listen_path; 1504 p = options.remote_forwards[i].listen_path = 1505 default_client_percent_expand(cp, cinfo); 1506 if (strcmp(cp, p) != 0) 1507 debug3("expanded RemoteForward listen path " 1508 "'%s' -> '%s'", cp, p); 1509 free(cp); 1510 } 1511 if (options.remote_forwards[i].connect_path != NULL) { 1512 cp = options.remote_forwards[i].connect_path; 1513 p = options.remote_forwards[i].connect_path = 1514 default_client_percent_expand(cp, cinfo); 1515 if (strcmp(cp, p) != 0) 1516 debug3("expanded RemoteForward connect path " 1517 "'%s' -> '%s'", cp, p); 1518 free(cp); 1519 } 1520 } 1521 1522 if (config_test) { 1523 dump_client_config(&options, host); 1524 exit(0); 1525 } 1526 1527 /* Expand SecurityKeyProvider if it refers to an environment variable */ 1528 if (options.sk_provider != NULL && *options.sk_provider == '$' && 1529 strlen(options.sk_provider) > 1) { 1530 if ((cp = getenv(options.sk_provider + 1)) == NULL) { 1531 debug("Authenticator provider %s did not resolve; " 1532 "disabling", options.sk_provider); 1533 free(options.sk_provider); 1534 options.sk_provider = NULL; 1535 } else { 1536 debug2("resolved SecurityKeyProvider %s => %s", 1537 options.sk_provider, cp); 1538 free(options.sk_provider); 1539 options.sk_provider = xstrdup(cp); 1540 } 1541 } 1542 1543 if (muxclient_command != 0 && options.control_path == NULL) 1544 fatal("No ControlPath specified for \"-O\" command"); 1545 if (options.control_path != NULL) { 1546 int sock; 1547 if ((sock = muxclient(options.control_path)) >= 0) { 1548 ssh_packet_set_connection(ssh, sock, sock); 1549 ssh_packet_set_mux(ssh); 1550 goto skip_connect; 1551 } 1552 } 1553 1554 /* 1555 * If hostname canonicalisation was not enabled, then we may not 1556 * have yet resolved the hostname. Do so now. 1557 */ 1558 if (addrs == NULL && options.proxy_command == NULL) { 1559 debug2("resolving \"%s\" port %d", host, options.port); 1560 if ((addrs = resolve_host(host, options.port, 1, 1561 cname, sizeof(cname))) == NULL) 1562 cleanup_exit(255); /* resolve_host logs the error */ 1563 } 1564 1565 if (options.connection_timeout >= INT_MAX/1000) 1566 timeout_ms = INT_MAX; 1567 else 1568 timeout_ms = options.connection_timeout * 1000; 1569 1570 /* Open a connection to the remote host. */ 1571 if (ssh_connect(ssh, host, host_arg, addrs, &hostaddr, options.port, 1572 options.connection_attempts, 1573 &timeout_ms, options.tcp_keep_alive) != 0) 1574 exit(255); 1575 1576 if (addrs != NULL) 1577 freeaddrinfo(addrs); 1578 1579 ssh_packet_set_timeout(ssh, options.server_alive_interval, 1580 options.server_alive_count_max); 1581 1582 if (timeout_ms > 0) 1583 debug3("timeout: %d ms remain after connect", timeout_ms); 1584 1585 /* 1586 * If we successfully made the connection and we have hostbased auth 1587 * enabled, load the public keys so we can later use the ssh-keysign 1588 * helper to sign challenges. 1589 */ 1590 sensitive_data.nkeys = 0; 1591 sensitive_data.keys = NULL; 1592 if (options.hostbased_authentication) { 1593 sensitive_data.nkeys = 10; 1594 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 1595 sizeof(struct sshkey)); 1596 1597 /* XXX check errors? */ 1598 #define L_PUBKEY(p,o) do { \ 1599 if ((o) >= sensitive_data.nkeys) \ 1600 fatal_f("pubkey out of array bounds"); \ 1601 check_load(sshkey_load_public(p, &(sensitive_data.keys[o]), NULL), \ 1602 p, "pubkey"); \ 1603 } while (0) 1604 #define L_CERT(p,o) do { \ 1605 if ((o) >= sensitive_data.nkeys) \ 1606 fatal_f("cert out of array bounds"); \ 1607 check_load(sshkey_load_cert(p, &(sensitive_data.keys[o])), p, "cert"); \ 1608 } while (0) 1609 1610 if (options.hostbased_authentication == 1) { 1611 L_CERT(_PATH_HOST_ECDSA_KEY_FILE, 0); 1612 L_CERT(_PATH_HOST_ED25519_KEY_FILE, 1); 1613 L_CERT(_PATH_HOST_RSA_KEY_FILE, 2); 1614 L_CERT(_PATH_HOST_DSA_KEY_FILE, 3); 1615 L_PUBKEY(_PATH_HOST_ECDSA_KEY_FILE, 4); 1616 L_PUBKEY(_PATH_HOST_ED25519_KEY_FILE, 5); 1617 L_PUBKEY(_PATH_HOST_RSA_KEY_FILE, 6); 1618 L_PUBKEY(_PATH_HOST_DSA_KEY_FILE, 7); 1619 L_CERT(_PATH_HOST_XMSS_KEY_FILE, 8); 1620 L_PUBKEY(_PATH_HOST_XMSS_KEY_FILE, 9); 1621 } 1622 } 1623 1624 /* load options.identity_files */ 1625 load_public_identity_files(cinfo); 1626 1627 /* optionally set the SSH_AUTHSOCKET_ENV_NAME variable */ 1628 if (options.identity_agent && 1629 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) { 1630 if (strcmp(options.identity_agent, "none") == 0) { 1631 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1632 } else { 1633 cp = options.identity_agent; 1634 /* legacy (limited) format */ 1635 if (cp[0] == '$' && cp[1] != '{') { 1636 if (!valid_env_name(cp + 1)) { 1637 fatal("Invalid IdentityAgent " 1638 "environment variable name %s", cp); 1639 } 1640 if ((p = getenv(cp + 1)) == NULL) 1641 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1642 else 1643 setenv(SSH_AUTHSOCKET_ENV_NAME, p, 1); 1644 } else { 1645 /* identity_agent specifies a path directly */ 1646 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1); 1647 } 1648 } 1649 } 1650 1651 if (options.forward_agent && options.forward_agent_sock_path != NULL) { 1652 cp = options.forward_agent_sock_path; 1653 if (cp[0] == '$') { 1654 if (!valid_env_name(cp + 1)) { 1655 fatal("Invalid ForwardAgent environment variable name %s", cp); 1656 } 1657 if ((p = getenv(cp + 1)) != NULL) 1658 forward_agent_sock_path = xstrdup(p); 1659 else 1660 options.forward_agent = 0; 1661 free(cp); 1662 } else { 1663 forward_agent_sock_path = cp; 1664 } 1665 } 1666 1667 /* Expand ~ in known host file names. */ 1668 tilde_expand_paths(options.system_hostfiles, 1669 options.num_system_hostfiles); 1670 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 1671 1672 ssh_signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 1673 ssh_signal(SIGCHLD, main_sigchld_handler); 1674 1675 /* Log into the remote system. Never returns if the login fails. */ 1676 ssh_login(ssh, &sensitive_data, host, (struct sockaddr *)&hostaddr, 1677 options.port, pw, timeout_ms, cinfo); 1678 1679 /* We no longer need the private host keys. Clear them now. */ 1680 if (sensitive_data.nkeys != 0) { 1681 for (i = 0; i < sensitive_data.nkeys; i++) { 1682 if (sensitive_data.keys[i] != NULL) { 1683 /* Destroys contents safely */ 1684 debug3("clear hostkey %d", i); 1685 sshkey_free(sensitive_data.keys[i]); 1686 sensitive_data.keys[i] = NULL; 1687 } 1688 } 1689 free(sensitive_data.keys); 1690 } 1691 for (i = 0; i < options.num_identity_files; i++) { 1692 free(options.identity_files[i]); 1693 options.identity_files[i] = NULL; 1694 if (options.identity_keys[i]) { 1695 sshkey_free(options.identity_keys[i]); 1696 options.identity_keys[i] = NULL; 1697 } 1698 } 1699 for (i = 0; i < options.num_certificate_files; i++) { 1700 free(options.certificate_files[i]); 1701 options.certificate_files[i] = NULL; 1702 } 1703 1704 #ifdef ENABLE_PKCS11 1705 (void)pkcs11_del_provider(options.pkcs11_provider); 1706 #endif 1707 1708 skip_connect: 1709 exit_status = ssh_session2(ssh, cinfo); 1710 ssh_conn_info_free(cinfo); 1711 ssh_packet_close(ssh); 1712 1713 if (options.control_path != NULL && muxserver_sock != -1) 1714 unlink(options.control_path); 1715 1716 /* Kill ProxyCommand if it is running. */ 1717 ssh_kill_proxy_command(); 1718 1719 return exit_status; 1720 } 1721 1722 static void 1723 control_persist_detach(void) 1724 { 1725 pid_t pid; 1726 1727 debug_f("backgrounding master process"); 1728 1729 /* 1730 * master (current process) into the background, and make the 1731 * foreground process a client of the backgrounded master. 1732 */ 1733 switch ((pid = fork())) { 1734 case -1: 1735 fatal_f("fork: %s", strerror(errno)); 1736 case 0: 1737 /* Child: master process continues mainloop */ 1738 break; 1739 default: 1740 /* Parent: set up mux client to connect to backgrounded master */ 1741 debug2_f("background process is %ld", (long)pid); 1742 options.stdin_null = ostdin_null_flag; 1743 options.request_tty = orequest_tty; 1744 tty_flag = otty_flag; 1745 options.session_type = osession_type; 1746 close(muxserver_sock); 1747 muxserver_sock = -1; 1748 options.control_master = SSHCTL_MASTER_NO; 1749 muxclient(options.control_path); 1750 /* muxclient() doesn't return on success. */ 1751 fatal("Failed to connect to new control master"); 1752 } 1753 if (stdfd_devnull(1, 1, !(log_is_on_stderr() && debug_flag)) == -1) 1754 error_f("stdfd_devnull failed"); 1755 daemon(1, 1); 1756 setproctitle("%s [mux]", options.control_path); 1757 } 1758 1759 /* Do fork() after authentication. Used by "ssh -f" */ 1760 static void 1761 fork_postauth(void) 1762 { 1763 if (need_controlpersist_detach) 1764 control_persist_detach(); 1765 debug("forking to background"); 1766 options.fork_after_authentication = 0; 1767 if (daemon(1, 1) == -1) 1768 fatal("daemon() failed: %.200s", strerror(errno)); 1769 if (stdfd_devnull(1, 1, !(log_is_on_stderr() && debug_flag)) == -1) 1770 error_f("stdfd_devnull failed"); 1771 } 1772 1773 static void 1774 forwarding_success(void) 1775 { 1776 if (forward_confirms_pending == -1) 1777 return; 1778 if (--forward_confirms_pending == 0) { 1779 debug_f("all expected forwarding replies received"); 1780 if (options.fork_after_authentication) 1781 fork_postauth(); 1782 } else { 1783 debug2_f("%d expected forwarding replies remaining", 1784 forward_confirms_pending); 1785 } 1786 } 1787 1788 /* Callback for remote forward global requests */ 1789 static void 1790 ssh_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt) 1791 { 1792 struct Forward *rfwd = (struct Forward *)ctxt; 1793 u_int port; 1794 int r; 1795 1796 /* XXX verbose() on failure? */ 1797 debug("remote forward %s for: listen %s%s%d, connect %s:%d", 1798 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1799 rfwd->listen_path ? rfwd->listen_path : 1800 rfwd->listen_host ? rfwd->listen_host : "", 1801 (rfwd->listen_path || rfwd->listen_host) ? ":" : "", 1802 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path : 1803 rfwd->connect_host, rfwd->connect_port); 1804 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) { 1805 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1806 if ((r = sshpkt_get_u32(ssh, &port)) != 0) 1807 fatal_fr(r, "parse packet"); 1808 if (port > 65535) { 1809 error("Invalid allocated port %u for remote " 1810 "forward to %s:%d", port, 1811 rfwd->connect_host, rfwd->connect_port); 1812 /* Ensure failure processing runs below */ 1813 type = SSH2_MSG_REQUEST_FAILURE; 1814 channel_update_permission(ssh, 1815 rfwd->handle, -1); 1816 } else { 1817 rfwd->allocated_port = (int)port; 1818 logit("Allocated port %u for remote " 1819 "forward to %s:%d", 1820 rfwd->allocated_port, rfwd->connect_host, 1821 rfwd->connect_port); 1822 channel_update_permission(ssh, 1823 rfwd->handle, rfwd->allocated_port); 1824 } 1825 } else { 1826 channel_update_permission(ssh, rfwd->handle, -1); 1827 } 1828 } 1829 1830 if (type == SSH2_MSG_REQUEST_FAILURE) { 1831 if (options.exit_on_forward_failure) { 1832 if (rfwd->listen_path != NULL) 1833 fatal("Error: remote port forwarding failed " 1834 "for listen path %s", rfwd->listen_path); 1835 else 1836 fatal("Error: remote port forwarding failed " 1837 "for listen port %d", rfwd->listen_port); 1838 } else { 1839 if (rfwd->listen_path != NULL) 1840 logit("Warning: remote port forwarding failed " 1841 "for listen path %s", rfwd->listen_path); 1842 else 1843 logit("Warning: remote port forwarding failed " 1844 "for listen port %d", rfwd->listen_port); 1845 } 1846 } 1847 forwarding_success(); 1848 } 1849 1850 static void 1851 client_cleanup_stdio_fwd(struct ssh *ssh, int id, void *arg) 1852 { 1853 debug("stdio forwarding: done"); 1854 cleanup_exit(0); 1855 } 1856 1857 static void 1858 ssh_stdio_confirm(struct ssh *ssh, int id, int success, void *arg) 1859 { 1860 if (!success) 1861 fatal("stdio forwarding failed"); 1862 } 1863 1864 static void 1865 ssh_tun_confirm(struct ssh *ssh, int id, int success, void *arg) 1866 { 1867 if (!success) { 1868 error("Tunnel forwarding failed"); 1869 if (options.exit_on_forward_failure) 1870 cleanup_exit(255); 1871 } 1872 1873 debug_f("tunnel forward established, id=%d", id); 1874 forwarding_success(); 1875 } 1876 1877 static void 1878 ssh_init_stdio_forwarding(struct ssh *ssh) 1879 { 1880 Channel *c; 1881 int in, out; 1882 1883 if (options.stdio_forward_host == NULL) 1884 return; 1885 1886 debug3_f("%s:%d", options.stdio_forward_host, 1887 options.stdio_forward_port); 1888 1889 if ((in = dup(STDIN_FILENO)) == -1 || 1890 (out = dup(STDOUT_FILENO)) == -1) 1891 fatal_f("dup() in/out failed"); 1892 if ((c = channel_connect_stdio_fwd(ssh, options.stdio_forward_host, 1893 options.stdio_forward_port, in, out, 1894 CHANNEL_NONBLOCK_STDIO)) == NULL) 1895 fatal_f("channel_connect_stdio_fwd failed"); 1896 channel_register_cleanup(ssh, c->self, client_cleanup_stdio_fwd, 0); 1897 channel_register_open_confirm(ssh, c->self, ssh_stdio_confirm, NULL); 1898 } 1899 1900 static void 1901 ssh_init_forward_permissions(struct ssh *ssh, const char *what, char **opens, 1902 u_int num_opens) 1903 { 1904 u_int i; 1905 int port; 1906 char *addr, *arg, *oarg, ch; 1907 int where = FORWARD_LOCAL; 1908 1909 channel_clear_permission(ssh, FORWARD_ADM, where); 1910 if (num_opens == 0) 1911 return; /* permit any */ 1912 1913 /* handle keywords: "any" / "none" */ 1914 if (num_opens == 1 && strcmp(opens[0], "any") == 0) 1915 return; 1916 if (num_opens == 1 && strcmp(opens[0], "none") == 0) { 1917 channel_disable_admin(ssh, where); 1918 return; 1919 } 1920 /* Otherwise treat it as a list of permitted host:port */ 1921 for (i = 0; i < num_opens; i++) { 1922 oarg = arg = xstrdup(opens[i]); 1923 ch = '\0'; 1924 addr = hpdelim2(&arg, &ch); 1925 if (addr == NULL || ch == '/') 1926 fatal_f("missing host in %s", what); 1927 addr = cleanhostname(addr); 1928 if (arg == NULL || ((port = permitopen_port(arg)) < 0)) 1929 fatal_f("bad port number in %s", what); 1930 /* Send it to channels layer */ 1931 channel_add_permission(ssh, FORWARD_ADM, 1932 where, addr, port); 1933 free(oarg); 1934 } 1935 } 1936 1937 static void 1938 ssh_init_forwarding(struct ssh *ssh, char **ifname) 1939 { 1940 int success = 0; 1941 int i; 1942 1943 ssh_init_forward_permissions(ssh, "permitremoteopen", 1944 options.permitted_remote_opens, 1945 options.num_permitted_remote_opens); 1946 1947 if (options.exit_on_forward_failure) 1948 forward_confirms_pending = 0; /* track pending requests */ 1949 /* Initiate local TCP/IP port forwardings. */ 1950 for (i = 0; i < options.num_local_forwards; i++) { 1951 debug("Local connections to %.200s:%d forwarded to remote " 1952 "address %.200s:%d", 1953 (options.local_forwards[i].listen_path != NULL) ? 1954 options.local_forwards[i].listen_path : 1955 (options.local_forwards[i].listen_host == NULL) ? 1956 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") : 1957 options.local_forwards[i].listen_host, 1958 options.local_forwards[i].listen_port, 1959 (options.local_forwards[i].connect_path != NULL) ? 1960 options.local_forwards[i].connect_path : 1961 options.local_forwards[i].connect_host, 1962 options.local_forwards[i].connect_port); 1963 success += channel_setup_local_fwd_listener(ssh, 1964 &options.local_forwards[i], &options.fwd_opts); 1965 } 1966 if (i > 0 && success != i && options.exit_on_forward_failure) 1967 fatal("Could not request local forwarding."); 1968 if (i > 0 && success == 0) 1969 error("Could not request local forwarding."); 1970 1971 /* Initiate remote TCP/IP port forwardings. */ 1972 for (i = 0; i < options.num_remote_forwards; i++) { 1973 debug("Remote connections from %.200s:%d forwarded to " 1974 "local address %.200s:%d", 1975 (options.remote_forwards[i].listen_path != NULL) ? 1976 options.remote_forwards[i].listen_path : 1977 (options.remote_forwards[i].listen_host == NULL) ? 1978 "LOCALHOST" : options.remote_forwards[i].listen_host, 1979 options.remote_forwards[i].listen_port, 1980 (options.remote_forwards[i].connect_path != NULL) ? 1981 options.remote_forwards[i].connect_path : 1982 options.remote_forwards[i].connect_host, 1983 options.remote_forwards[i].connect_port); 1984 if ((options.remote_forwards[i].handle = 1985 channel_request_remote_forwarding(ssh, 1986 &options.remote_forwards[i])) >= 0) { 1987 client_register_global_confirm( 1988 ssh_confirm_remote_forward, 1989 &options.remote_forwards[i]); 1990 forward_confirms_pending++; 1991 } else if (options.exit_on_forward_failure) 1992 fatal("Could not request remote forwarding."); 1993 else 1994 logit("Warning: Could not request remote forwarding."); 1995 } 1996 1997 /* Initiate tunnel forwarding. */ 1998 if (options.tun_open != SSH_TUNMODE_NO) { 1999 if ((*ifname = client_request_tun_fwd(ssh, 2000 options.tun_open, options.tun_local, 2001 options.tun_remote, ssh_tun_confirm, NULL)) != NULL) 2002 forward_confirms_pending++; 2003 else if (options.exit_on_forward_failure) 2004 fatal("Could not request tunnel forwarding."); 2005 else 2006 error("Could not request tunnel forwarding."); 2007 } 2008 if (forward_confirms_pending > 0) { 2009 debug_f("expecting replies for %d forwards", 2010 forward_confirms_pending); 2011 } 2012 } 2013 2014 static void 2015 check_agent_present(void) 2016 { 2017 int r; 2018 2019 if (options.forward_agent) { 2020 /* Clear agent forwarding if we don't have an agent. */ 2021 if ((r = ssh_get_authentication_socket(NULL)) != 0) { 2022 options.forward_agent = 0; 2023 if (r != SSH_ERR_AGENT_NOT_PRESENT) 2024 debug_r(r, "ssh_get_authentication_socket"); 2025 } 2026 } 2027 } 2028 2029 static void 2030 ssh_session2_setup(struct ssh *ssh, int id, int success, void *arg) 2031 { 2032 extern char **environ; 2033 const char *display, *term; 2034 int r, interactive = tty_flag; 2035 char *proto = NULL, *data = NULL; 2036 2037 if (!success) 2038 return; /* No need for error message, channels code sens one */ 2039 2040 display = getenv("DISPLAY"); 2041 if (display == NULL && options.forward_x11) 2042 debug("X11 forwarding requested but DISPLAY not set"); 2043 if (options.forward_x11 && client_x11_get_proto(ssh, display, 2044 options.xauth_location, options.forward_x11_trusted, 2045 options.forward_x11_timeout, &proto, &data) == 0) { 2046 /* Request forwarding with authentication spoofing. */ 2047 debug("Requesting X11 forwarding with authentication " 2048 "spoofing."); 2049 x11_request_forwarding_with_spoofing(ssh, id, display, proto, 2050 data, 1); 2051 client_expect_confirm(ssh, id, "X11 forwarding", CONFIRM_WARN); 2052 /* XXX exit_on_forward_failure */ 2053 interactive = 1; 2054 } 2055 2056 check_agent_present(); 2057 if (options.forward_agent) { 2058 debug("Requesting authentication agent forwarding."); 2059 channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0); 2060 if ((r = sshpkt_send(ssh)) != 0) 2061 fatal_fr(r, "send packet"); 2062 } 2063 2064 /* Tell the packet module whether this is an interactive session. */ 2065 ssh_packet_set_interactive(ssh, interactive, 2066 options.ip_qos_interactive, options.ip_qos_bulk); 2067 2068 if ((term = lookup_env_in_list("TERM", options.setenv, 2069 options.num_setenv)) == NULL || *term == '\0') 2070 term = getenv("TERM"); 2071 client_session2_setup(ssh, id, tty_flag, 2072 options.session_type == SESSION_TYPE_SUBSYSTEM, term, 2073 NULL, fileno(stdin), command, environ); 2074 } 2075 2076 /* open new channel for a session */ 2077 static int 2078 ssh_session2_open(struct ssh *ssh) 2079 { 2080 Channel *c; 2081 int window, packetmax, in, out, err; 2082 2083 if (options.stdin_null) { 2084 in = open(_PATH_DEVNULL, O_RDONLY); 2085 } else { 2086 in = dup(STDIN_FILENO); 2087 } 2088 out = dup(STDOUT_FILENO); 2089 err = dup(STDERR_FILENO); 2090 2091 if (in == -1 || out == -1 || err == -1) 2092 fatal("dup() in/out/err failed"); 2093 2094 window = CHAN_SES_WINDOW_DEFAULT; 2095 packetmax = CHAN_SES_PACKET_DEFAULT; 2096 if (tty_flag) { 2097 window >>= 1; 2098 packetmax >>= 1; 2099 } 2100 c = channel_new(ssh, 2101 "session", SSH_CHANNEL_OPENING, in, out, err, 2102 window, packetmax, CHAN_EXTENDED_WRITE, 2103 "client-session", CHANNEL_NONBLOCK_STDIO); 2104 2105 debug3_f("channel_new: %d", c->self); 2106 2107 channel_send_open(ssh, c->self); 2108 if (options.session_type != SESSION_TYPE_NONE) 2109 channel_register_open_confirm(ssh, c->self, 2110 ssh_session2_setup, NULL); 2111 2112 return c->self; 2113 } 2114 2115 static int 2116 ssh_session2(struct ssh *ssh, const struct ssh_conn_info *cinfo) 2117 { 2118 int r, id = -1; 2119 char *cp, *tun_fwd_ifname = NULL; 2120 2121 /* XXX should be pre-session */ 2122 if (!options.control_persist) 2123 ssh_init_stdio_forwarding(ssh); 2124 2125 ssh_init_forwarding(ssh, &tun_fwd_ifname); 2126 2127 if (options.local_command != NULL) { 2128 debug3("expanding LocalCommand: %s", options.local_command); 2129 cp = options.local_command; 2130 options.local_command = percent_expand(cp, 2131 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo), 2132 "T", tun_fwd_ifname == NULL ? "NONE" : tun_fwd_ifname, 2133 (char *)NULL); 2134 debug3("expanded LocalCommand: %s", options.local_command); 2135 free(cp); 2136 } 2137 2138 /* Start listening for multiplex clients */ 2139 if (!ssh_packet_get_mux(ssh)) 2140 muxserver_listen(ssh); 2141 2142 /* 2143 * If we are in control persist mode and have a working mux listen 2144 * socket, then prepare to background ourselves and have a foreground 2145 * client attach as a control client. 2146 * NB. we must save copies of the flags that we override for 2147 * the backgrounding, since we defer attachment of the client until 2148 * after the connection is fully established (in particular, 2149 * async rfwd replies have been received for ExitOnForwardFailure). 2150 */ 2151 if (options.control_persist && muxserver_sock != -1) { 2152 ostdin_null_flag = options.stdin_null; 2153 osession_type = options.session_type; 2154 orequest_tty = options.request_tty; 2155 otty_flag = tty_flag; 2156 options.stdin_null = 1; 2157 options.session_type = SESSION_TYPE_NONE; 2158 tty_flag = 0; 2159 if (!options.fork_after_authentication && 2160 (osession_type != SESSION_TYPE_NONE || 2161 options.stdio_forward_host != NULL)) 2162 need_controlpersist_detach = 1; 2163 options.fork_after_authentication = 1; 2164 } 2165 /* 2166 * ControlPersist mux listen socket setup failed, attempt the 2167 * stdio forward setup that we skipped earlier. 2168 */ 2169 if (options.control_persist && muxserver_sock == -1) 2170 ssh_init_stdio_forwarding(ssh); 2171 2172 if (options.session_type != SESSION_TYPE_NONE) 2173 id = ssh_session2_open(ssh); 2174 else { 2175 ssh_packet_set_interactive(ssh, 2176 options.control_master == SSHCTL_MASTER_NO, 2177 options.ip_qos_interactive, options.ip_qos_bulk); 2178 } 2179 2180 /* If we don't expect to open a new session, then disallow it */ 2181 if (options.control_master == SSHCTL_MASTER_NO && 2182 (ssh->compat & SSH_NEW_OPENSSH)) { 2183 debug("Requesting no-more-sessions@openssh.com"); 2184 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 2185 (r = sshpkt_put_cstring(ssh, 2186 "no-more-sessions@openssh.com")) != 0 || 2187 (r = sshpkt_put_u8(ssh, 0)) != 0 || 2188 (r = sshpkt_send(ssh)) != 0) 2189 fatal_fr(r, "send packet"); 2190 } 2191 2192 /* Execute a local command */ 2193 if (options.local_command != NULL && 2194 options.permit_local_command) 2195 ssh_local_cmd(options.local_command); 2196 2197 /* 2198 * stdout is now owned by the session channel; clobber it here 2199 * so future channel closes are propagated to the local fd. 2200 * NB. this can only happen after LocalCommand has completed, 2201 * as it may want to write to stdout. 2202 */ 2203 if (!need_controlpersist_detach && stdfd_devnull(0, 1, 0) == -1) 2204 error_f("stdfd_devnull failed"); 2205 2206 /* 2207 * If requested and we are not interested in replies to remote 2208 * forwarding requests, then let ssh continue in the background. 2209 */ 2210 if (options.fork_after_authentication) { 2211 if (options.exit_on_forward_failure && 2212 options.num_remote_forwards > 0) { 2213 debug("deferring postauth fork until remote forward " 2214 "confirmation received"); 2215 } else 2216 fork_postauth(); 2217 } 2218 2219 return client_loop(ssh, tty_flag, tty_flag ? 2220 options.escape_char : SSH_ESCAPECHAR_NONE, id); 2221 } 2222 2223 /* Loads all IdentityFile and CertificateFile keys */ 2224 static void 2225 load_public_identity_files(const struct ssh_conn_info *cinfo) 2226 { 2227 char *filename, *cp; 2228 struct sshkey *public; 2229 int i; 2230 u_int n_ids, n_certs; 2231 char *identity_files[SSH_MAX_IDENTITY_FILES]; 2232 struct sshkey *identity_keys[SSH_MAX_IDENTITY_FILES]; 2233 int identity_file_userprovided[SSH_MAX_IDENTITY_FILES]; 2234 char *certificate_files[SSH_MAX_CERTIFICATE_FILES]; 2235 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES]; 2236 int certificate_file_userprovided[SSH_MAX_CERTIFICATE_FILES]; 2237 #ifdef ENABLE_PKCS11 2238 struct sshkey **keys = NULL; 2239 char **comments = NULL; 2240 int nkeys; 2241 #endif /* PKCS11 */ 2242 2243 n_ids = n_certs = 0; 2244 memset(identity_files, 0, sizeof(identity_files)); 2245 memset(identity_keys, 0, sizeof(identity_keys)); 2246 memset(identity_file_userprovided, 0, 2247 sizeof(identity_file_userprovided)); 2248 memset(certificate_files, 0, sizeof(certificate_files)); 2249 memset(certificates, 0, sizeof(certificates)); 2250 memset(certificate_file_userprovided, 0, 2251 sizeof(certificate_file_userprovided)); 2252 2253 #ifdef ENABLE_PKCS11 2254 if (options.pkcs11_provider != NULL && 2255 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 2256 (pkcs11_init(!options.batch_mode) == 0) && 2257 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 2258 &keys, &comments)) > 0) { 2259 for (i = 0; i < nkeys; i++) { 2260 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 2261 sshkey_free(keys[i]); 2262 free(comments[i]); 2263 continue; 2264 } 2265 identity_keys[n_ids] = keys[i]; 2266 identity_files[n_ids] = comments[i]; /* transferred */ 2267 n_ids++; 2268 } 2269 free(keys); 2270 free(comments); 2271 } 2272 #endif /* ENABLE_PKCS11 */ 2273 for (i = 0; i < options.num_identity_files; i++) { 2274 if (n_ids >= SSH_MAX_IDENTITY_FILES || 2275 strcasecmp(options.identity_files[i], "none") == 0) { 2276 free(options.identity_files[i]); 2277 options.identity_files[i] = NULL; 2278 continue; 2279 } 2280 cp = tilde_expand_filename(options.identity_files[i], getuid()); 2281 filename = default_client_percent_dollar_expand(cp, cinfo); 2282 free(cp); 2283 check_load(sshkey_load_public(filename, &public, NULL), 2284 filename, "pubkey"); 2285 debug("identity file %s type %d", filename, 2286 public ? public->type : -1); 2287 free(options.identity_files[i]); 2288 identity_files[n_ids] = filename; 2289 identity_keys[n_ids] = public; 2290 identity_file_userprovided[n_ids] = 2291 options.identity_file_userprovided[i]; 2292 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 2293 continue; 2294 2295 /* 2296 * If no certificates have been explicitly listed then try 2297 * to add the default certificate variant too. 2298 */ 2299 if (options.num_certificate_files != 0) 2300 continue; 2301 xasprintf(&cp, "%s-cert", filename); 2302 check_load(sshkey_load_public(cp, &public, NULL), 2303 filename, "pubkey"); 2304 debug("identity file %s type %d", cp, 2305 public ? public->type : -1); 2306 if (public == NULL) { 2307 free(cp); 2308 continue; 2309 } 2310 if (!sshkey_is_cert(public)) { 2311 debug_f("key %s type %s is not a certificate", 2312 cp, sshkey_type(public)); 2313 sshkey_free(public); 2314 free(cp); 2315 continue; 2316 } 2317 /* NB. leave filename pointing to private key */ 2318 identity_files[n_ids] = xstrdup(filename); 2319 identity_keys[n_ids] = public; 2320 identity_file_userprovided[n_ids] = 2321 options.identity_file_userprovided[i]; 2322 n_ids++; 2323 } 2324 2325 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES) 2326 fatal_f("too many certificates"); 2327 for (i = 0; i < options.num_certificate_files; i++) { 2328 cp = tilde_expand_filename(options.certificate_files[i], 2329 getuid()); 2330 filename = default_client_percent_dollar_expand(cp, cinfo); 2331 free(cp); 2332 2333 check_load(sshkey_load_public(filename, &public, NULL), 2334 filename, "certificate"); 2335 debug("certificate file %s type %d", filename, 2336 public ? public->type : -1); 2337 free(options.certificate_files[i]); 2338 options.certificate_files[i] = NULL; 2339 if (public == NULL) { 2340 free(filename); 2341 continue; 2342 } 2343 if (!sshkey_is_cert(public)) { 2344 debug_f("key %s type %s is not a certificate", 2345 filename, sshkey_type(public)); 2346 sshkey_free(public); 2347 free(filename); 2348 continue; 2349 } 2350 certificate_files[n_certs] = filename; 2351 certificates[n_certs] = public; 2352 certificate_file_userprovided[n_certs] = 2353 options.certificate_file_userprovided[i]; 2354 ++n_certs; 2355 } 2356 2357 options.num_identity_files = n_ids; 2358 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 2359 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 2360 memcpy(options.identity_file_userprovided, 2361 identity_file_userprovided, sizeof(identity_file_userprovided)); 2362 2363 options.num_certificate_files = n_certs; 2364 memcpy(options.certificate_files, 2365 certificate_files, sizeof(certificate_files)); 2366 memcpy(options.certificates, certificates, sizeof(certificates)); 2367 memcpy(options.certificate_file_userprovided, 2368 certificate_file_userprovided, 2369 sizeof(certificate_file_userprovided)); 2370 } 2371 2372 static void 2373 main_sigchld_handler(int sig) 2374 { 2375 int save_errno = errno; 2376 pid_t pid; 2377 int status; 2378 2379 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 2380 (pid == -1 && errno == EINTR)) 2381 ; 2382 errno = save_errno; 2383 } 2384