1 /* $OpenBSD: ssh.c,v 1.500 2019/01/19 21:43:56 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * Ssh client program. This program can be used to log into a remote machine. 7 * The software supports strong authentication, encryption, and forwarding 8 * of X11, TCP/IP, and authentication connections. 9 * 10 * As far as I am concerned, the code I have written for this software 11 * can be used freely for any purpose. Any derived versions of this 12 * software must be clearly marked as such, and if the derived work is 13 * incompatible with the protocol description in the RFC file, it must be 14 * called by a name other than "ssh" or "Secure Shell". 15 * 16 * Copyright (c) 1999 Niels Provos. All rights reserved. 17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved. 18 * 19 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu> 20 * in Canada (German citizen). 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the above copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 41 */ 42 43 #include "includes.h" 44 45 #include <sys/types.h> 46 #ifdef HAVE_SYS_STAT_H 47 # include <sys/stat.h> 48 #endif 49 #include <sys/resource.h> 50 #include <sys/ioctl.h> 51 #include <sys/socket.h> 52 #include <sys/wait.h> 53 54 #include <ctype.h> 55 #include <errno.h> 56 #include <fcntl.h> 57 #include <netdb.h> 58 #ifdef HAVE_PATHS_H 59 #include <paths.h> 60 #endif 61 #include <pwd.h> 62 #include <signal.h> 63 #include <stdarg.h> 64 #include <stddef.h> 65 #include <stdio.h> 66 #include <stdlib.h> 67 #include <string.h> 68 #include <unistd.h> 69 #include <limits.h> 70 #include <locale.h> 71 72 #include <netinet/in.h> 73 #include <arpa/inet.h> 74 75 #ifdef WITH_OPENSSL 76 #include <openssl/evp.h> 77 #include <openssl/err.h> 78 #endif 79 #include "openbsd-compat/openssl-compat.h" 80 #include "openbsd-compat/sys-queue.h" 81 82 #include "xmalloc.h" 83 #include "ssh.h" 84 #include "ssh2.h" 85 #include "canohost.h" 86 #include "compat.h" 87 #include "cipher.h" 88 #include "digest.h" 89 #include "packet.h" 90 #include "sshbuf.h" 91 #include "channels.h" 92 #include "sshkey.h" 93 #include "authfd.h" 94 #include "authfile.h" 95 #include "pathnames.h" 96 #include "dispatch.h" 97 #include "clientloop.h" 98 #include "log.h" 99 #include "misc.h" 100 #include "readconf.h" 101 #include "sshconnect.h" 102 #include "kex.h" 103 #include "mac.h" 104 #include "sshpty.h" 105 #include "match.h" 106 #include "msg.h" 107 #include "version.h" 108 #include "ssherr.h" 109 #include "myproposal.h" 110 #include "utf8.h" 111 112 #ifdef ENABLE_PKCS11 113 #include "ssh-pkcs11.h" 114 #endif 115 116 extern char *__progname; 117 118 /* Saves a copy of argv for setproctitle emulation */ 119 #ifndef HAVE_SETPROCTITLE 120 static char **saved_av; 121 #endif 122 123 /* Flag indicating whether debug mode is on. May be set on the command line. */ 124 int debug_flag = 0; 125 126 /* Flag indicating whether a tty should be requested */ 127 int tty_flag = 0; 128 129 /* don't exec a shell */ 130 int no_shell_flag = 0; 131 132 /* 133 * Flag indicating that nothing should be read from stdin. This can be set 134 * on the command line. 135 */ 136 int stdin_null_flag = 0; 137 138 /* 139 * Flag indicating that the current process should be backgrounded and 140 * a new slave launched in the foreground for ControlPersist. 141 */ 142 int need_controlpersist_detach = 0; 143 144 /* Copies of flags for ControlPersist foreground slave */ 145 int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty; 146 147 /* 148 * Flag indicating that ssh should fork after authentication. This is useful 149 * so that the passphrase can be entered manually, and then ssh goes to the 150 * background. 151 */ 152 int fork_after_authentication_flag = 0; 153 154 /* 155 * General data structure for command line options and options configurable 156 * in configuration files. See readconf.h. 157 */ 158 Options options; 159 160 /* optional user configfile */ 161 char *config = NULL; 162 163 /* 164 * Name of the host we are connecting to. This is the name given on the 165 * command line, or the HostName specified for the user-supplied name in a 166 * configuration file. 167 */ 168 char *host; 169 170 /* Various strings used to to percent_expand() arguments */ 171 static char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 172 static char uidstr[32], *host_arg, *conn_hash_hex; 173 174 /* socket address the host resolves to */ 175 struct sockaddr_storage hostaddr; 176 177 /* Private host keys. */ 178 Sensitive sensitive_data; 179 180 /* command to be executed */ 181 struct sshbuf *command; 182 183 /* Should we execute a command or invoke a subsystem? */ 184 int subsystem_flag = 0; 185 186 /* # of replies received for global requests */ 187 static int remote_forward_confirms_received = 0; 188 189 /* mux.c */ 190 extern int muxserver_sock; 191 extern u_int muxclient_command; 192 193 /* Prints a help message to the user. This function never returns. */ 194 195 static void 196 usage(void) 197 { 198 fprintf(stderr, 199 "usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]\n" 200 " [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]\n" 201 " [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]\n" 202 " [-i identity_file] [-J [user@]host[:port]] [-L address]\n" 203 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" 204 " [-Q query_option] [-R address] [-S ctl_path] [-W host:port]\n" 205 " [-w local_tun[:remote_tun]] destination [command]\n" 206 ); 207 exit(255); 208 } 209 210 static int ssh_session2(struct ssh *, struct passwd *); 211 static void load_public_identity_files(struct passwd *); 212 static void main_sigchld_handler(int); 213 214 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 215 static void 216 tilde_expand_paths(char **paths, u_int num_paths) 217 { 218 u_int i; 219 char *cp; 220 221 for (i = 0; i < num_paths; i++) { 222 cp = tilde_expand_filename(paths[i], getuid()); 223 free(paths[i]); 224 paths[i] = cp; 225 } 226 } 227 228 /* 229 * Attempt to resolve a host name / port to a set of addresses and 230 * optionally return any CNAMEs encountered along the way. 231 * Returns NULL on failure. 232 * NB. this function must operate with a options having undefined members. 233 */ 234 static struct addrinfo * 235 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen) 236 { 237 char strport[NI_MAXSERV]; 238 struct addrinfo hints, *res; 239 int gaierr, loglevel = SYSLOG_LEVEL_DEBUG1; 240 241 if (port <= 0) 242 port = default_ssh_port(); 243 244 snprintf(strport, sizeof strport, "%d", port); 245 memset(&hints, 0, sizeof(hints)); 246 hints.ai_family = options.address_family == -1 ? 247 AF_UNSPEC : options.address_family; 248 hints.ai_socktype = SOCK_STREAM; 249 if (cname != NULL) 250 hints.ai_flags = AI_CANONNAME; 251 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 252 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) 253 loglevel = SYSLOG_LEVEL_ERROR; 254 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", 255 __progname, name, ssh_gai_strerror(gaierr)); 256 return NULL; 257 } 258 if (cname != NULL && res->ai_canonname != NULL) { 259 if (strlcpy(cname, res->ai_canonname, clen) >= clen) { 260 error("%s: host \"%s\" cname \"%s\" too long (max %lu)", 261 __func__, name, res->ai_canonname, (u_long)clen); 262 if (clen > 0) 263 *cname = '\0'; 264 } 265 } 266 return res; 267 } 268 269 /* Returns non-zero if name can only be an address and not a hostname */ 270 static int 271 is_addr_fast(const char *name) 272 { 273 return (strchr(name, '%') != NULL || strchr(name, ':') != NULL || 274 strspn(name, "0123456789.") == strlen(name)); 275 } 276 277 /* Returns non-zero if name represents a valid, single address */ 278 static int 279 is_addr(const char *name) 280 { 281 char strport[NI_MAXSERV]; 282 struct addrinfo hints, *res; 283 284 if (is_addr_fast(name)) 285 return 1; 286 287 snprintf(strport, sizeof strport, "%u", default_ssh_port()); 288 memset(&hints, 0, sizeof(hints)); 289 hints.ai_family = options.address_family == -1 ? 290 AF_UNSPEC : options.address_family; 291 hints.ai_socktype = SOCK_STREAM; 292 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 293 if (getaddrinfo(name, strport, &hints, &res) != 0) 294 return 0; 295 if (res == NULL || res->ai_next != NULL) { 296 freeaddrinfo(res); 297 return 0; 298 } 299 freeaddrinfo(res); 300 return 1; 301 } 302 303 /* 304 * Attempt to resolve a numeric host address / port to a single address. 305 * Returns a canonical address string. 306 * Returns NULL on failure. 307 * NB. this function must operate with a options having undefined members. 308 */ 309 static struct addrinfo * 310 resolve_addr(const char *name, int port, char *caddr, size_t clen) 311 { 312 char addr[NI_MAXHOST], strport[NI_MAXSERV]; 313 struct addrinfo hints, *res; 314 int gaierr; 315 316 if (port <= 0) 317 port = default_ssh_port(); 318 snprintf(strport, sizeof strport, "%u", port); 319 memset(&hints, 0, sizeof(hints)); 320 hints.ai_family = options.address_family == -1 ? 321 AF_UNSPEC : options.address_family; 322 hints.ai_socktype = SOCK_STREAM; 323 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 324 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 325 debug2("%s: could not resolve name %.100s as address: %s", 326 __func__, name, ssh_gai_strerror(gaierr)); 327 return NULL; 328 } 329 if (res == NULL) { 330 debug("%s: getaddrinfo %.100s returned no addresses", 331 __func__, name); 332 return NULL; 333 } 334 if (res->ai_next != NULL) { 335 debug("%s: getaddrinfo %.100s returned multiple addresses", 336 __func__, name); 337 goto fail; 338 } 339 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen, 340 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) { 341 debug("%s: Could not format address for name %.100s: %s", 342 __func__, name, ssh_gai_strerror(gaierr)); 343 goto fail; 344 } 345 if (strlcpy(caddr, addr, clen) >= clen) { 346 error("%s: host \"%s\" addr \"%s\" too long (max %lu)", 347 __func__, name, addr, (u_long)clen); 348 if (clen > 0) 349 *caddr = '\0'; 350 fail: 351 freeaddrinfo(res); 352 return NULL; 353 } 354 return res; 355 } 356 357 /* 358 * Check whether the cname is a permitted replacement for the hostname 359 * and perform the replacement if it is. 360 * NB. this function must operate with a options having undefined members. 361 */ 362 static int 363 check_follow_cname(int direct, char **namep, const char *cname) 364 { 365 int i; 366 struct allowed_cname *rule; 367 368 if (*cname == '\0' || options.num_permitted_cnames == 0 || 369 strcmp(*namep, cname) == 0) 370 return 0; 371 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 372 return 0; 373 /* 374 * Don't attempt to canonicalize names that will be interpreted by 375 * a proxy or jump host unless the user specifically requests so. 376 */ 377 if (!direct && 378 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 379 return 0; 380 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname); 381 for (i = 0; i < options.num_permitted_cnames; i++) { 382 rule = options.permitted_cnames + i; 383 if (match_pattern_list(*namep, rule->source_list, 1) != 1 || 384 match_pattern_list(cname, rule->target_list, 1) != 1) 385 continue; 386 verbose("Canonicalized DNS aliased hostname " 387 "\"%s\" => \"%s\"", *namep, cname); 388 free(*namep); 389 *namep = xstrdup(cname); 390 return 1; 391 } 392 return 0; 393 } 394 395 /* 396 * Attempt to resolve the supplied hostname after applying the user's 397 * canonicalization rules. Returns the address list for the host or NULL 398 * if no name was found after canonicalization. 399 * NB. this function must operate with a options having undefined members. 400 */ 401 static struct addrinfo * 402 resolve_canonicalize(char **hostp, int port) 403 { 404 int i, direct, ndots; 405 char *cp, *fullhost, newname[NI_MAXHOST]; 406 struct addrinfo *addrs; 407 408 /* 409 * Attempt to canonicalise addresses, regardless of 410 * whether hostname canonicalisation was requested 411 */ 412 if ((addrs = resolve_addr(*hostp, port, 413 newname, sizeof(newname))) != NULL) { 414 debug2("%s: hostname %.100s is address", __func__, *hostp); 415 if (strcasecmp(*hostp, newname) != 0) { 416 debug2("%s: canonicalised address \"%s\" => \"%s\"", 417 __func__, *hostp, newname); 418 free(*hostp); 419 *hostp = xstrdup(newname); 420 } 421 return addrs; 422 } 423 424 /* 425 * If this looks like an address but didn't parse as one, it might 426 * be an address with an invalid interface scope. Skip further 427 * attempts at canonicalisation. 428 */ 429 if (is_addr_fast(*hostp)) { 430 debug("%s: hostname %.100s is an unrecognised address", 431 __func__, *hostp); 432 return NULL; 433 } 434 435 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 436 return NULL; 437 438 /* 439 * Don't attempt to canonicalize names that will be interpreted by 440 * a proxy unless the user specifically requests so. 441 */ 442 direct = option_clear_or_none(options.proxy_command) && 443 options.jump_host == NULL; 444 if (!direct && 445 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 446 return NULL; 447 448 /* If domain name is anchored, then resolve it now */ 449 if ((*hostp)[strlen(*hostp) - 1] == '.') { 450 debug3("%s: name is fully qualified", __func__); 451 fullhost = xstrdup(*hostp); 452 if ((addrs = resolve_host(fullhost, port, 0, 453 newname, sizeof(newname))) != NULL) 454 goto found; 455 free(fullhost); 456 goto notfound; 457 } 458 459 /* Don't apply canonicalization to sufficiently-qualified hostnames */ 460 ndots = 0; 461 for (cp = *hostp; *cp != '\0'; cp++) { 462 if (*cp == '.') 463 ndots++; 464 } 465 if (ndots > options.canonicalize_max_dots) { 466 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)", 467 __func__, *hostp, options.canonicalize_max_dots); 468 return NULL; 469 } 470 /* Attempt each supplied suffix */ 471 for (i = 0; i < options.num_canonical_domains; i++) { 472 *newname = '\0'; 473 xasprintf(&fullhost, "%s.%s.", *hostp, 474 options.canonical_domains[i]); 475 debug3("%s: attempting \"%s\" => \"%s\"", __func__, 476 *hostp, fullhost); 477 if ((addrs = resolve_host(fullhost, port, 0, 478 newname, sizeof(newname))) == NULL) { 479 free(fullhost); 480 continue; 481 } 482 found: 483 /* Remove trailing '.' */ 484 fullhost[strlen(fullhost) - 1] = '\0'; 485 /* Follow CNAME if requested */ 486 if (!check_follow_cname(direct, &fullhost, newname)) { 487 debug("Canonicalized hostname \"%s\" => \"%s\"", 488 *hostp, fullhost); 489 } 490 free(*hostp); 491 *hostp = fullhost; 492 return addrs; 493 } 494 notfound: 495 if (!options.canonicalize_fallback_local) 496 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); 497 debug2("%s: host %s not found in any suffix", __func__, *hostp); 498 return NULL; 499 } 500 501 /* 502 * Check the result of hostkey loading, ignoring some errors and 503 * fatal()ing for others. 504 */ 505 static void 506 check_load(int r, const char *path, const char *message) 507 { 508 switch (r) { 509 case 0: 510 break; 511 case SSH_ERR_INTERNAL_ERROR: 512 case SSH_ERR_ALLOC_FAIL: 513 fatal("load %s \"%s\": %s", message, path, ssh_err(r)); 514 case SSH_ERR_SYSTEM_ERROR: 515 /* Ignore missing files */ 516 if (errno == ENOENT) 517 break; 518 /* FALLTHROUGH */ 519 default: 520 error("load %s \"%s\": %s", message, path, ssh_err(r)); 521 break; 522 } 523 } 524 525 /* 526 * Read per-user configuration file. Ignore the system wide config 527 * file if the user specifies a config file on the command line. 528 */ 529 static void 530 process_config_files(const char *host_name, struct passwd *pw, int final_pass, 531 int *want_final_pass) 532 { 533 char buf[PATH_MAX]; 534 int r; 535 536 if (config != NULL) { 537 if (strcasecmp(config, "none") != 0 && 538 !read_config_file(config, pw, host, host_name, &options, 539 SSHCONF_USERCONF | (final_pass ? SSHCONF_FINAL : 0), 540 want_final_pass)) 541 fatal("Can't open user config file %.100s: " 542 "%.100s", config, strerror(errno)); 543 } else { 544 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 545 _PATH_SSH_USER_CONFFILE); 546 if (r > 0 && (size_t)r < sizeof(buf)) 547 (void)read_config_file(buf, pw, host, host_name, 548 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF | 549 (final_pass ? SSHCONF_FINAL : 0), want_final_pass); 550 551 /* Read systemwide configuration file after user config. */ 552 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, 553 host, host_name, &options, 554 final_pass ? SSHCONF_FINAL : 0, want_final_pass); 555 } 556 } 557 558 /* Rewrite the port number in an addrinfo list of addresses */ 559 static void 560 set_addrinfo_port(struct addrinfo *addrs, int port) 561 { 562 struct addrinfo *addr; 563 564 for (addr = addrs; addr != NULL; addr = addr->ai_next) { 565 switch (addr->ai_family) { 566 case AF_INET: 567 ((struct sockaddr_in *)addr->ai_addr)-> 568 sin_port = htons(port); 569 break; 570 case AF_INET6: 571 ((struct sockaddr_in6 *)addr->ai_addr)-> 572 sin6_port = htons(port); 573 break; 574 } 575 } 576 } 577 578 /* 579 * Main program for the ssh client. 580 */ 581 int 582 main(int ac, char **av) 583 { 584 struct ssh *ssh = NULL; 585 int i, r, opt, exit_status, use_syslog, direct, timeout_ms; 586 int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0; 587 char *p, *cp, *line, *argv0, buf[PATH_MAX], *logfile; 588 char cname[NI_MAXHOST]; 589 struct stat st; 590 struct passwd *pw; 591 extern int optind, optreset; 592 extern char *optarg; 593 struct Forward fwd; 594 struct addrinfo *addrs = NULL; 595 struct ssh_digest_ctx *md; 596 u_char conn_hash[SSH_DIGEST_MAX_LENGTH]; 597 598 ssh_malloc_init(); /* must be called before any mallocs */ 599 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 600 sanitise_stdfd(); 601 602 __progname = ssh_get_progname(av[0]); 603 604 #ifndef HAVE_SETPROCTITLE 605 /* Prepare for later setproctitle emulation */ 606 /* Save argv so it isn't clobbered by setproctitle() emulation */ 607 saved_av = xcalloc(ac + 1, sizeof(*saved_av)); 608 for (i = 0; i < ac; i++) 609 saved_av[i] = xstrdup(av[i]); 610 saved_av[i] = NULL; 611 compat_init_setproctitle(ac, av); 612 av = saved_av; 613 #endif 614 615 seed_rng(); 616 617 /* 618 * Discard other fds that are hanging around. These can cause problem 619 * with backgrounded ssh processes started by ControlPersist. 620 */ 621 closefrom(STDERR_FILENO + 1); 622 623 /* Get user data. */ 624 pw = getpwuid(getuid()); 625 if (!pw) { 626 logit("No user exists for uid %lu", (u_long)getuid()); 627 exit(255); 628 } 629 /* Take a copy of the returned structure. */ 630 pw = pwcopy(pw); 631 632 /* 633 * Set our umask to something reasonable, as some files are created 634 * with the default umask. This will make them world-readable but 635 * writable only by the owner, which is ok for all files for which we 636 * don't set the modes explicitly. 637 */ 638 umask(022); 639 640 msetlocale(); 641 642 /* 643 * Initialize option structure to indicate that no values have been 644 * set. 645 */ 646 initialize_options(&options); 647 648 /* 649 * Prepare main ssh transport/connection structures 650 */ 651 if ((ssh = ssh_alloc_session_state()) == NULL) 652 fatal("Couldn't allocate session state"); 653 channel_init_channels(ssh); 654 655 /* Parse command-line arguments. */ 656 host = NULL; 657 use_syslog = 0; 658 logfile = NULL; 659 argv0 = av[0]; 660 661 again: 662 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 663 "AB:CD:E:F:GI:J:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { 664 switch (opt) { 665 case '1': 666 fatal("SSH protocol v.1 is no longer supported"); 667 break; 668 case '2': 669 /* Ignored */ 670 break; 671 case '4': 672 options.address_family = AF_INET; 673 break; 674 case '6': 675 options.address_family = AF_INET6; 676 break; 677 case 'n': 678 stdin_null_flag = 1; 679 break; 680 case 'f': 681 fork_after_authentication_flag = 1; 682 stdin_null_flag = 1; 683 break; 684 case 'x': 685 options.forward_x11 = 0; 686 break; 687 case 'X': 688 options.forward_x11 = 1; 689 break; 690 case 'y': 691 use_syslog = 1; 692 break; 693 case 'E': 694 logfile = optarg; 695 break; 696 case 'G': 697 config_test = 1; 698 break; 699 case 'Y': 700 options.forward_x11 = 1; 701 options.forward_x11_trusted = 1; 702 break; 703 case 'g': 704 options.fwd_opts.gateway_ports = 1; 705 break; 706 case 'O': 707 if (options.stdio_forward_host != NULL) 708 fatal("Cannot specify multiplexing " 709 "command with -W"); 710 else if (muxclient_command != 0) 711 fatal("Multiplexing command already specified"); 712 if (strcmp(optarg, "check") == 0) 713 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 714 else if (strcmp(optarg, "forward") == 0) 715 muxclient_command = SSHMUX_COMMAND_FORWARD; 716 else if (strcmp(optarg, "exit") == 0) 717 muxclient_command = SSHMUX_COMMAND_TERMINATE; 718 else if (strcmp(optarg, "stop") == 0) 719 muxclient_command = SSHMUX_COMMAND_STOP; 720 else if (strcmp(optarg, "cancel") == 0) 721 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 722 else if (strcmp(optarg, "proxy") == 0) 723 muxclient_command = SSHMUX_COMMAND_PROXY; 724 else 725 fatal("Invalid multiplex command."); 726 break; 727 case 'P': /* deprecated */ 728 break; 729 case 'Q': 730 cp = NULL; 731 if (strcmp(optarg, "cipher") == 0) 732 cp = cipher_alg_list('\n', 0); 733 else if (strcmp(optarg, "cipher-auth") == 0) 734 cp = cipher_alg_list('\n', 1); 735 else if (strcmp(optarg, "mac") == 0) 736 cp = mac_alg_list('\n'); 737 else if (strcmp(optarg, "kex") == 0) 738 cp = kex_alg_list('\n'); 739 else if (strcmp(optarg, "key") == 0) 740 cp = sshkey_alg_list(0, 0, 0, '\n'); 741 else if (strcmp(optarg, "key-cert") == 0) 742 cp = sshkey_alg_list(1, 0, 0, '\n'); 743 else if (strcmp(optarg, "key-plain") == 0) 744 cp = sshkey_alg_list(0, 1, 0, '\n'); 745 else if (strcmp(optarg, "sig") == 0) 746 cp = sshkey_alg_list(0, 1, 1, '\n'); 747 else if (strcmp(optarg, "protocol-version") == 0) 748 cp = xstrdup("2"); 749 else if (strcmp(optarg, "help") == 0) { 750 cp = xstrdup( 751 "cipher\ncipher-auth\nkex\nkey\n" 752 "key-cert\nkey-plain\nmac\n" 753 "protocol-version\nsig"); 754 } 755 if (cp == NULL) 756 fatal("Unsupported query \"%s\"", optarg); 757 printf("%s\n", cp); 758 free(cp); 759 exit(0); 760 break; 761 case 'a': 762 options.forward_agent = 0; 763 break; 764 case 'A': 765 options.forward_agent = 1; 766 break; 767 case 'k': 768 options.gss_deleg_creds = 0; 769 break; 770 case 'K': 771 options.gss_authentication = 1; 772 options.gss_deleg_creds = 1; 773 break; 774 case 'i': 775 p = tilde_expand_filename(optarg, getuid()); 776 if (stat(p, &st) < 0) 777 fprintf(stderr, "Warning: Identity file %s " 778 "not accessible: %s.\n", p, 779 strerror(errno)); 780 else 781 add_identity_file(&options, NULL, p, 1); 782 free(p); 783 break; 784 case 'I': 785 #ifdef ENABLE_PKCS11 786 free(options.pkcs11_provider); 787 options.pkcs11_provider = xstrdup(optarg); 788 #else 789 fprintf(stderr, "no support for PKCS#11.\n"); 790 #endif 791 break; 792 case 'J': 793 if (options.jump_host != NULL) 794 fatal("Only a single -J option permitted"); 795 if (options.proxy_command != NULL) 796 fatal("Cannot specify -J with ProxyCommand"); 797 if (parse_jump(optarg, &options, 1) == -1) 798 fatal("Invalid -J argument"); 799 options.proxy_command = xstrdup("none"); 800 break; 801 case 't': 802 if (options.request_tty == REQUEST_TTY_YES) 803 options.request_tty = REQUEST_TTY_FORCE; 804 else 805 options.request_tty = REQUEST_TTY_YES; 806 break; 807 case 'v': 808 if (debug_flag == 0) { 809 debug_flag = 1; 810 options.log_level = SYSLOG_LEVEL_DEBUG1; 811 } else { 812 if (options.log_level < SYSLOG_LEVEL_DEBUG3) { 813 debug_flag++; 814 options.log_level++; 815 } 816 } 817 break; 818 case 'V': 819 fprintf(stderr, "%s, %s\n", 820 SSH_RELEASE, 821 #ifdef WITH_OPENSSL 822 OpenSSL_version(OPENSSL_VERSION) 823 #else 824 "without OpenSSL" 825 #endif 826 ); 827 if (opt == 'V') 828 exit(0); 829 break; 830 case 'w': 831 if (options.tun_open == -1) 832 options.tun_open = SSH_TUNMODE_DEFAULT; 833 options.tun_local = a2tun(optarg, &options.tun_remote); 834 if (options.tun_local == SSH_TUNID_ERR) { 835 fprintf(stderr, 836 "Bad tun device '%s'\n", optarg); 837 exit(255); 838 } 839 break; 840 case 'W': 841 if (options.stdio_forward_host != NULL) 842 fatal("stdio forward already specified"); 843 if (muxclient_command != 0) 844 fatal("Cannot specify stdio forward with -O"); 845 if (parse_forward(&fwd, optarg, 1, 0)) { 846 options.stdio_forward_host = fwd.listen_host; 847 options.stdio_forward_port = fwd.listen_port; 848 free(fwd.connect_host); 849 } else { 850 fprintf(stderr, 851 "Bad stdio forwarding specification '%s'\n", 852 optarg); 853 exit(255); 854 } 855 options.request_tty = REQUEST_TTY_NO; 856 no_shell_flag = 1; 857 break; 858 case 'q': 859 options.log_level = SYSLOG_LEVEL_QUIET; 860 break; 861 case 'e': 862 if (optarg[0] == '^' && optarg[2] == 0 && 863 (u_char) optarg[1] >= 64 && 864 (u_char) optarg[1] < 128) 865 options.escape_char = (u_char) optarg[1] & 31; 866 else if (strlen(optarg) == 1) 867 options.escape_char = (u_char) optarg[0]; 868 else if (strcmp(optarg, "none") == 0) 869 options.escape_char = SSH_ESCAPECHAR_NONE; 870 else { 871 fprintf(stderr, "Bad escape character '%s'.\n", 872 optarg); 873 exit(255); 874 } 875 break; 876 case 'c': 877 if (!ciphers_valid(*optarg == '+' ? 878 optarg + 1 : optarg)) { 879 fprintf(stderr, "Unknown cipher type '%s'\n", 880 optarg); 881 exit(255); 882 } 883 free(options.ciphers); 884 options.ciphers = xstrdup(optarg); 885 break; 886 case 'm': 887 if (mac_valid(optarg)) { 888 free(options.macs); 889 options.macs = xstrdup(optarg); 890 } else { 891 fprintf(stderr, "Unknown mac type '%s'\n", 892 optarg); 893 exit(255); 894 } 895 break; 896 case 'M': 897 if (options.control_master == SSHCTL_MASTER_YES) 898 options.control_master = SSHCTL_MASTER_ASK; 899 else 900 options.control_master = SSHCTL_MASTER_YES; 901 break; 902 case 'p': 903 if (options.port == -1) { 904 options.port = a2port(optarg); 905 if (options.port <= 0) { 906 fprintf(stderr, "Bad port '%s'\n", 907 optarg); 908 exit(255); 909 } 910 } 911 break; 912 case 'l': 913 if (options.user == NULL) 914 options.user = optarg; 915 break; 916 917 case 'L': 918 if (parse_forward(&fwd, optarg, 0, 0)) 919 add_local_forward(&options, &fwd); 920 else { 921 fprintf(stderr, 922 "Bad local forwarding specification '%s'\n", 923 optarg); 924 exit(255); 925 } 926 break; 927 928 case 'R': 929 if (parse_forward(&fwd, optarg, 0, 1) || 930 parse_forward(&fwd, optarg, 1, 1)) { 931 add_remote_forward(&options, &fwd); 932 } else { 933 fprintf(stderr, 934 "Bad remote forwarding specification " 935 "'%s'\n", optarg); 936 exit(255); 937 } 938 break; 939 940 case 'D': 941 if (parse_forward(&fwd, optarg, 1, 0)) { 942 add_local_forward(&options, &fwd); 943 } else { 944 fprintf(stderr, 945 "Bad dynamic forwarding specification " 946 "'%s'\n", optarg); 947 exit(255); 948 } 949 break; 950 951 case 'C': 952 options.compression = 1; 953 break; 954 case 'N': 955 no_shell_flag = 1; 956 options.request_tty = REQUEST_TTY_NO; 957 break; 958 case 'T': 959 options.request_tty = REQUEST_TTY_NO; 960 break; 961 case 'o': 962 line = xstrdup(optarg); 963 if (process_config_line(&options, pw, 964 host ? host : "", host ? host : "", line, 965 "command-line", 0, NULL, SSHCONF_USERCONF) != 0) 966 exit(255); 967 free(line); 968 break; 969 case 's': 970 subsystem_flag = 1; 971 break; 972 case 'S': 973 free(options.control_path); 974 options.control_path = xstrdup(optarg); 975 break; 976 case 'b': 977 options.bind_address = optarg; 978 break; 979 case 'B': 980 options.bind_interface = optarg; 981 break; 982 case 'F': 983 config = optarg; 984 break; 985 default: 986 usage(); 987 } 988 } 989 990 if (optind > 1 && strcmp(av[optind - 1], "--") == 0) 991 opt_terminated = 1; 992 993 ac -= optind; 994 av += optind; 995 996 if (ac > 0 && !host) { 997 int tport; 998 char *tuser; 999 switch (parse_ssh_uri(*av, &tuser, &host, &tport)) { 1000 case -1: 1001 usage(); 1002 break; 1003 case 0: 1004 if (options.user == NULL) { 1005 options.user = tuser; 1006 tuser = NULL; 1007 } 1008 free(tuser); 1009 if (options.port == -1 && tport != -1) 1010 options.port = tport; 1011 break; 1012 default: 1013 p = xstrdup(*av); 1014 cp = strrchr(p, '@'); 1015 if (cp != NULL) { 1016 if (cp == p) 1017 usage(); 1018 if (options.user == NULL) { 1019 options.user = p; 1020 p = NULL; 1021 } 1022 *cp++ = '\0'; 1023 host = xstrdup(cp); 1024 free(p); 1025 } else 1026 host = p; 1027 break; 1028 } 1029 if (ac > 1 && !opt_terminated) { 1030 optind = optreset = 1; 1031 goto again; 1032 } 1033 ac--, av++; 1034 } 1035 1036 /* Check that we got a host name. */ 1037 if (!host) 1038 usage(); 1039 1040 host_arg = xstrdup(host); 1041 1042 /* Initialize the command to execute on remote host. */ 1043 if ((command = sshbuf_new()) == NULL) 1044 fatal("sshbuf_new failed"); 1045 1046 /* 1047 * Save the command to execute on the remote host in a buffer. There 1048 * is no limit on the length of the command, except by the maximum 1049 * packet size. Also sets the tty flag if there is no command. 1050 */ 1051 if (!ac) { 1052 /* No command specified - execute shell on a tty. */ 1053 if (subsystem_flag) { 1054 fprintf(stderr, 1055 "You must specify a subsystem to invoke.\n"); 1056 usage(); 1057 } 1058 } else { 1059 /* A command has been specified. Store it into the buffer. */ 1060 for (i = 0; i < ac; i++) { 1061 if ((r = sshbuf_putf(command, "%s%s", 1062 i ? " " : "", av[i])) != 0) 1063 fatal("%s: buffer error: %s", 1064 __func__, ssh_err(r)); 1065 } 1066 } 1067 1068 /* 1069 * Initialize "log" output. Since we are the client all output 1070 * goes to stderr unless otherwise specified by -y or -E. 1071 */ 1072 if (use_syslog && logfile != NULL) 1073 fatal("Can't specify both -y and -E"); 1074 if (logfile != NULL) 1075 log_redirect_stderr_to(logfile); 1076 log_init(argv0, 1077 options.log_level == SYSLOG_LEVEL_NOT_SET ? 1078 SYSLOG_LEVEL_INFO : options.log_level, 1079 options.log_facility == SYSLOG_FACILITY_NOT_SET ? 1080 SYSLOG_FACILITY_USER : options.log_facility, 1081 !use_syslog); 1082 1083 if (debug_flag) 1084 logit("%s, %s", SSH_RELEASE, 1085 #ifdef WITH_OPENSSL 1086 OpenSSL_version(OPENSSL_VERSION) 1087 #else 1088 "without OpenSSL" 1089 #endif 1090 ); 1091 1092 /* Parse the configuration files */ 1093 process_config_files(host_arg, pw, 0, &want_final_pass); 1094 if (want_final_pass) 1095 debug("configuration requests final Match pass"); 1096 1097 /* Hostname canonicalisation needs a few options filled. */ 1098 fill_default_options_for_canonicalization(&options); 1099 1100 /* If the user has replaced the hostname then take it into use now */ 1101 if (options.hostname != NULL) { 1102 /* NB. Please keep in sync with readconf.c:match_cfg_line() */ 1103 cp = percent_expand(options.hostname, 1104 "h", host, (char *)NULL); 1105 free(host); 1106 host = cp; 1107 free(options.hostname); 1108 options.hostname = xstrdup(host); 1109 } 1110 1111 /* Don't lowercase addresses, they will be explicitly canonicalised */ 1112 if ((was_addr = is_addr(host)) == 0) 1113 lowercase(host); 1114 1115 /* 1116 * Try to canonicalize if requested by configuration or the 1117 * hostname is an address. 1118 */ 1119 if (options.canonicalize_hostname != SSH_CANONICALISE_NO || was_addr) 1120 addrs = resolve_canonicalize(&host, options.port); 1121 1122 /* 1123 * If CanonicalizePermittedCNAMEs have been specified but 1124 * other canonicalization did not happen (by not being requested 1125 * or by failing with fallback) then the hostname may still be changed 1126 * as a result of CNAME following. 1127 * 1128 * Try to resolve the bare hostname name using the system resolver's 1129 * usual search rules and then apply the CNAME follow rules. 1130 * 1131 * Skip the lookup if a ProxyCommand is being used unless the user 1132 * has specifically requested canonicalisation for this case via 1133 * CanonicalizeHostname=always 1134 */ 1135 direct = option_clear_or_none(options.proxy_command) && 1136 options.jump_host == NULL; 1137 if (addrs == NULL && options.num_permitted_cnames != 0 && (direct || 1138 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { 1139 if ((addrs = resolve_host(host, options.port, 1140 direct, cname, sizeof(cname))) == NULL) { 1141 /* Don't fatal proxied host names not in the DNS */ 1142 if (direct) 1143 cleanup_exit(255); /* logged in resolve_host */ 1144 } else 1145 check_follow_cname(direct, &host, cname); 1146 } 1147 1148 /* 1149 * If canonicalisation is enabled then re-parse the configuration 1150 * files as new stanzas may match. 1151 */ 1152 if (options.canonicalize_hostname != 0 && !want_final_pass) { 1153 debug("hostname canonicalisation enabled, " 1154 "will re-parse configuration"); 1155 want_final_pass = 1; 1156 } 1157 1158 if (want_final_pass) { 1159 debug("re-parsing configuration"); 1160 free(options.hostname); 1161 options.hostname = xstrdup(host); 1162 process_config_files(host_arg, pw, 1, NULL); 1163 /* 1164 * Address resolution happens early with canonicalisation 1165 * enabled and the port number may have changed since, so 1166 * reset it in address list 1167 */ 1168 if (addrs != NULL && options.port > 0) 1169 set_addrinfo_port(addrs, options.port); 1170 } 1171 1172 /* Fill configuration defaults. */ 1173 fill_default_options(&options); 1174 1175 /* 1176 * If ProxyJump option specified, then construct a ProxyCommand now. 1177 */ 1178 if (options.jump_host != NULL) { 1179 char port_s[8]; 1180 const char *sshbin = argv0; 1181 1182 /* 1183 * Try to use SSH indicated by argv[0], but fall back to 1184 * "ssh" if it appears unavailable. 1185 */ 1186 if (strchr(argv0, '/') != NULL && access(argv0, X_OK) != 0) 1187 sshbin = "ssh"; 1188 1189 /* Consistency check */ 1190 if (options.proxy_command != NULL) 1191 fatal("inconsistent options: ProxyCommand+ProxyJump"); 1192 /* Never use FD passing for ProxyJump */ 1193 options.proxy_use_fdpass = 0; 1194 snprintf(port_s, sizeof(port_s), "%d", options.jump_port); 1195 xasprintf(&options.proxy_command, 1196 "%s%s%s%s%s%s%s%s%s%s%.*s -W '[%%h]:%%p' %s", 1197 sshbin, 1198 /* Optional "-l user" argument if jump_user set */ 1199 options.jump_user == NULL ? "" : " -l ", 1200 options.jump_user == NULL ? "" : options.jump_user, 1201 /* Optional "-p port" argument if jump_port set */ 1202 options.jump_port <= 0 ? "" : " -p ", 1203 options.jump_port <= 0 ? "" : port_s, 1204 /* Optional additional jump hosts ",..." */ 1205 options.jump_extra == NULL ? "" : " -J ", 1206 options.jump_extra == NULL ? "" : options.jump_extra, 1207 /* Optional "-F" argumment if -F specified */ 1208 config == NULL ? "" : " -F ", 1209 config == NULL ? "" : config, 1210 /* Optional "-v" arguments if -v set */ 1211 debug_flag ? " -" : "", 1212 debug_flag, "vvv", 1213 /* Mandatory hostname */ 1214 options.jump_host); 1215 debug("Setting implicit ProxyCommand from ProxyJump: %s", 1216 options.proxy_command); 1217 } 1218 1219 if (options.port == 0) 1220 options.port = default_ssh_port(); 1221 channel_set_af(ssh, options.address_family); 1222 1223 /* Tidy and check options */ 1224 if (options.host_key_alias != NULL) 1225 lowercase(options.host_key_alias); 1226 if (options.proxy_command != NULL && 1227 strcmp(options.proxy_command, "-") == 0 && 1228 options.proxy_use_fdpass) 1229 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); 1230 if (options.control_persist && 1231 options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 1232 debug("UpdateHostKeys=ask is incompatible with ControlPersist; " 1233 "disabling"); 1234 options.update_hostkeys = 0; 1235 } 1236 if (options.connection_attempts <= 0) 1237 fatal("Invalid number of ConnectionAttempts"); 1238 1239 if (sshbuf_len(command) != 0 && options.remote_command != NULL) 1240 fatal("Cannot execute command-line and remote command."); 1241 1242 /* Cannot fork to background if no command. */ 1243 if (fork_after_authentication_flag && sshbuf_len(command) == 0 && 1244 options.remote_command == NULL && !no_shell_flag) 1245 fatal("Cannot fork into background without a command " 1246 "to execute."); 1247 1248 /* reinit */ 1249 log_init(argv0, options.log_level, options.log_facility, !use_syslog); 1250 1251 if (options.request_tty == REQUEST_TTY_YES || 1252 options.request_tty == REQUEST_TTY_FORCE) 1253 tty_flag = 1; 1254 1255 /* Allocate a tty by default if no command specified. */ 1256 if (sshbuf_len(command) == 0 && options.remote_command == NULL) 1257 tty_flag = options.request_tty != REQUEST_TTY_NO; 1258 1259 /* Force no tty */ 1260 if (options.request_tty == REQUEST_TTY_NO || 1261 (muxclient_command && muxclient_command != SSHMUX_COMMAND_PROXY)) 1262 tty_flag = 0; 1263 /* Do not allocate a tty if stdin is not a tty. */ 1264 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 1265 options.request_tty != REQUEST_TTY_FORCE) { 1266 if (tty_flag) 1267 logit("Pseudo-terminal will not be allocated because " 1268 "stdin is not a terminal."); 1269 tty_flag = 0; 1270 } 1271 1272 if (options.user == NULL) 1273 options.user = xstrdup(pw->pw_name); 1274 1275 /* Set up strings used to percent_expand() arguments */ 1276 if (gethostname(thishost, sizeof(thishost)) == -1) 1277 fatal("gethostname: %s", strerror(errno)); 1278 strlcpy(shorthost, thishost, sizeof(shorthost)); 1279 shorthost[strcspn(thishost, ".")] = '\0'; 1280 snprintf(portstr, sizeof(portstr), "%d", options.port); 1281 snprintf(uidstr, sizeof(uidstr), "%llu", 1282 (unsigned long long)pw->pw_uid); 1283 1284 if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL || 1285 ssh_digest_update(md, thishost, strlen(thishost)) < 0 || 1286 ssh_digest_update(md, host, strlen(host)) < 0 || 1287 ssh_digest_update(md, portstr, strlen(portstr)) < 0 || 1288 ssh_digest_update(md, options.user, strlen(options.user)) < 0 || 1289 ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0) 1290 fatal("%s: mux digest failed", __func__); 1291 ssh_digest_free(md); 1292 conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1)); 1293 1294 /* 1295 * Expand tokens in arguments. NB. LocalCommand is expanded later, 1296 * after port-forwarding is set up, so it may pick up any local 1297 * tunnel interface name allocated. 1298 */ 1299 if (options.remote_command != NULL) { 1300 debug3("expanding RemoteCommand: %s", options.remote_command); 1301 cp = options.remote_command; 1302 options.remote_command = percent_expand(cp, 1303 "C", conn_hash_hex, 1304 "L", shorthost, 1305 "d", pw->pw_dir, 1306 "h", host, 1307 "i", uidstr, 1308 "l", thishost, 1309 "n", host_arg, 1310 "p", portstr, 1311 "r", options.user, 1312 "u", pw->pw_name, 1313 (char *)NULL); 1314 debug3("expanded RemoteCommand: %s", options.remote_command); 1315 free(cp); 1316 if ((r = sshbuf_put(command, options.remote_command, 1317 strlen(options.remote_command))) != 0) 1318 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1319 } 1320 1321 if (options.control_path != NULL) { 1322 cp = tilde_expand_filename(options.control_path, getuid()); 1323 free(options.control_path); 1324 options.control_path = percent_expand(cp, 1325 "C", conn_hash_hex, 1326 "L", shorthost, 1327 "h", host, 1328 "i", uidstr, 1329 "l", thishost, 1330 "n", host_arg, 1331 "p", portstr, 1332 "r", options.user, 1333 "u", pw->pw_name, 1334 "i", uidstr, 1335 (char *)NULL); 1336 free(cp); 1337 } 1338 1339 if (config_test) { 1340 dump_client_config(&options, host); 1341 exit(0); 1342 } 1343 1344 if (muxclient_command != 0 && options.control_path == NULL) 1345 fatal("No ControlPath specified for \"-O\" command"); 1346 if (options.control_path != NULL) { 1347 int sock; 1348 if ((sock = muxclient(options.control_path)) >= 0) { 1349 ssh_packet_set_connection(ssh, sock, sock); 1350 ssh_packet_set_mux(ssh); 1351 goto skip_connect; 1352 } 1353 } 1354 1355 /* 1356 * If hostname canonicalisation was not enabled, then we may not 1357 * have yet resolved the hostname. Do so now. 1358 */ 1359 if (addrs == NULL && options.proxy_command == NULL) { 1360 debug2("resolving \"%s\" port %d", host, options.port); 1361 if ((addrs = resolve_host(host, options.port, 1, 1362 cname, sizeof(cname))) == NULL) 1363 cleanup_exit(255); /* resolve_host logs the error */ 1364 } 1365 1366 timeout_ms = options.connection_timeout * 1000; 1367 1368 /* Open a connection to the remote host. */ 1369 if (ssh_connect(ssh, host, addrs, &hostaddr, options.port, 1370 options.address_family, options.connection_attempts, 1371 &timeout_ms, options.tcp_keep_alive) != 0) 1372 exit(255); 1373 1374 if (addrs != NULL) 1375 freeaddrinfo(addrs); 1376 1377 ssh_packet_set_timeout(ssh, options.server_alive_interval, 1378 options.server_alive_count_max); 1379 1380 if (timeout_ms > 0) 1381 debug3("timeout: %d ms remain after connect", timeout_ms); 1382 1383 /* 1384 * If we successfully made the connection and we have hostbased auth 1385 * enabled, load the public keys so we can later use the ssh-keysign 1386 * helper to sign challenges. 1387 */ 1388 sensitive_data.nkeys = 0; 1389 sensitive_data.keys = NULL; 1390 if (options.hostbased_authentication) { 1391 sensitive_data.nkeys = 10; 1392 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 1393 sizeof(struct sshkey)); 1394 1395 /* XXX check errors? */ 1396 #define L_PUBKEY(p,o) do { \ 1397 if ((o) >= sensitive_data.nkeys) \ 1398 fatal("%s pubkey out of array bounds", __func__); \ 1399 check_load(sshkey_load_public(p, &(sensitive_data.keys[o]), NULL), \ 1400 p, "pubkey"); \ 1401 } while (0) 1402 #define L_CERT(p,o) do { \ 1403 if ((o) >= sensitive_data.nkeys) \ 1404 fatal("%s cert out of array bounds", __func__); \ 1405 check_load(sshkey_load_cert(p, &(sensitive_data.keys[o])), p, "cert"); \ 1406 } while (0) 1407 1408 if (options.hostbased_authentication == 1) { 1409 L_CERT(_PATH_HOST_ECDSA_KEY_FILE, 0); 1410 L_CERT(_PATH_HOST_ED25519_KEY_FILE, 1); 1411 L_CERT(_PATH_HOST_RSA_KEY_FILE, 2); 1412 L_CERT(_PATH_HOST_DSA_KEY_FILE, 3); 1413 L_PUBKEY(_PATH_HOST_ECDSA_KEY_FILE, 4); 1414 L_PUBKEY(_PATH_HOST_ED25519_KEY_FILE, 5); 1415 L_PUBKEY(_PATH_HOST_RSA_KEY_FILE, 6); 1416 L_PUBKEY(_PATH_HOST_DSA_KEY_FILE, 7); 1417 L_CERT(_PATH_HOST_XMSS_KEY_FILE, 8); 1418 L_PUBKEY(_PATH_HOST_XMSS_KEY_FILE, 9); 1419 } 1420 } 1421 1422 /* Create ~/.ssh * directory if it doesn't already exist. */ 1423 if (config == NULL) { 1424 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 1425 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 1426 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) { 1427 #ifdef WITH_SELINUX 1428 ssh_selinux_setfscreatecon(buf); 1429 #endif 1430 if (mkdir(buf, 0700) < 0) 1431 error("Could not create directory '%.200s'.", 1432 buf); 1433 #ifdef WITH_SELINUX 1434 ssh_selinux_setfscreatecon(NULL); 1435 #endif 1436 } 1437 } 1438 /* load options.identity_files */ 1439 load_public_identity_files(pw); 1440 1441 /* optionally set the SSH_AUTHSOCKET_ENV_NAME variable */ 1442 if (options.identity_agent && 1443 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) { 1444 if (strcmp(options.identity_agent, "none") == 0) { 1445 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1446 } else { 1447 p = tilde_expand_filename(options.identity_agent, 1448 getuid()); 1449 cp = percent_expand(p, 1450 "d", pw->pw_dir, 1451 "h", host, 1452 "i", uidstr, 1453 "l", thishost, 1454 "r", options.user, 1455 "u", pw->pw_name, 1456 (char *)NULL); 1457 free(p); 1458 /* 1459 * If identity_agent represents an environment variable 1460 * then recheck that it is valid (since processing with 1461 * percent_expand() may have changed it) and substitute 1462 * its value. 1463 */ 1464 if (cp[0] == '$') { 1465 if (!valid_env_name(cp + 1)) { 1466 fatal("Invalid IdentityAgent " 1467 "environment variable name %s", cp); 1468 } 1469 if ((p = getenv(cp + 1)) == NULL) 1470 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1471 else 1472 setenv(SSH_AUTHSOCKET_ENV_NAME, p, 1); 1473 } else { 1474 /* identity_agent specifies a path directly */ 1475 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1); 1476 } 1477 free(cp); 1478 } 1479 } 1480 1481 /* Expand ~ in known host file names. */ 1482 tilde_expand_paths(options.system_hostfiles, 1483 options.num_system_hostfiles); 1484 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 1485 1486 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 1487 signal(SIGCHLD, main_sigchld_handler); 1488 1489 /* Log into the remote system. Never returns if the login fails. */ 1490 ssh_login(ssh, &sensitive_data, host, (struct sockaddr *)&hostaddr, 1491 options.port, pw, timeout_ms); 1492 1493 if (ssh_packet_connection_is_on_socket(ssh)) { 1494 verbose("Authenticated to %s ([%s]:%d).", host, 1495 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); 1496 } else { 1497 verbose("Authenticated to %s (via proxy).", host); 1498 } 1499 1500 /* We no longer need the private host keys. Clear them now. */ 1501 if (sensitive_data.nkeys != 0) { 1502 for (i = 0; i < sensitive_data.nkeys; i++) { 1503 if (sensitive_data.keys[i] != NULL) { 1504 /* Destroys contents safely */ 1505 debug3("clear hostkey %d", i); 1506 sshkey_free(sensitive_data.keys[i]); 1507 sensitive_data.keys[i] = NULL; 1508 } 1509 } 1510 free(sensitive_data.keys); 1511 } 1512 for (i = 0; i < options.num_identity_files; i++) { 1513 free(options.identity_files[i]); 1514 options.identity_files[i] = NULL; 1515 if (options.identity_keys[i]) { 1516 sshkey_free(options.identity_keys[i]); 1517 options.identity_keys[i] = NULL; 1518 } 1519 } 1520 for (i = 0; i < options.num_certificate_files; i++) { 1521 free(options.certificate_files[i]); 1522 options.certificate_files[i] = NULL; 1523 } 1524 1525 skip_connect: 1526 exit_status = ssh_session2(ssh, pw); 1527 ssh_packet_close(ssh); 1528 1529 if (options.control_path != NULL && muxserver_sock != -1) 1530 unlink(options.control_path); 1531 1532 /* Kill ProxyCommand if it is running. */ 1533 ssh_kill_proxy_command(); 1534 1535 return exit_status; 1536 } 1537 1538 static void 1539 control_persist_detach(void) 1540 { 1541 pid_t pid; 1542 int devnull, keep_stderr; 1543 1544 debug("%s: backgrounding master process", __func__); 1545 1546 /* 1547 * master (current process) into the background, and make the 1548 * foreground process a client of the backgrounded master. 1549 */ 1550 switch ((pid = fork())) { 1551 case -1: 1552 fatal("%s: fork: %s", __func__, strerror(errno)); 1553 case 0: 1554 /* Child: master process continues mainloop */ 1555 break; 1556 default: 1557 /* Parent: set up mux slave to connect to backgrounded master */ 1558 debug2("%s: background process is %ld", __func__, (long)pid); 1559 stdin_null_flag = ostdin_null_flag; 1560 options.request_tty = orequest_tty; 1561 tty_flag = otty_flag; 1562 close(muxserver_sock); 1563 muxserver_sock = -1; 1564 options.control_master = SSHCTL_MASTER_NO; 1565 muxclient(options.control_path); 1566 /* muxclient() doesn't return on success. */ 1567 fatal("Failed to connect to new control master"); 1568 } 1569 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1570 error("%s: open(\"/dev/null\"): %s", __func__, 1571 strerror(errno)); 1572 } else { 1573 keep_stderr = log_is_on_stderr() && debug_flag; 1574 if (dup2(devnull, STDIN_FILENO) == -1 || 1575 dup2(devnull, STDOUT_FILENO) == -1 || 1576 (!keep_stderr && dup2(devnull, STDERR_FILENO) == -1)) 1577 error("%s: dup2: %s", __func__, strerror(errno)); 1578 if (devnull > STDERR_FILENO) 1579 close(devnull); 1580 } 1581 daemon(1, 1); 1582 setproctitle("%s [mux]", options.control_path); 1583 } 1584 1585 /* Do fork() after authentication. Used by "ssh -f" */ 1586 static void 1587 fork_postauth(void) 1588 { 1589 if (need_controlpersist_detach) 1590 control_persist_detach(); 1591 debug("forking to background"); 1592 fork_after_authentication_flag = 0; 1593 if (daemon(1, 1) < 0) 1594 fatal("daemon() failed: %.200s", strerror(errno)); 1595 } 1596 1597 /* Callback for remote forward global requests */ 1598 static void 1599 ssh_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt) 1600 { 1601 struct Forward *rfwd = (struct Forward *)ctxt; 1602 u_int port; 1603 int r; 1604 1605 /* XXX verbose() on failure? */ 1606 debug("remote forward %s for: listen %s%s%d, connect %s:%d", 1607 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1608 rfwd->listen_path ? rfwd->listen_path : 1609 rfwd->listen_host ? rfwd->listen_host : "", 1610 (rfwd->listen_path || rfwd->listen_host) ? ":" : "", 1611 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path : 1612 rfwd->connect_host, rfwd->connect_port); 1613 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) { 1614 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1615 if ((r = sshpkt_get_u32(ssh, &port)) != 0) 1616 fatal("%s: %s", __func__, ssh_err(r)); 1617 if (port > 65535) { 1618 error("Invalid allocated port %u for remote " 1619 "forward to %s:%d", port, 1620 rfwd->connect_host, rfwd->connect_port); 1621 /* Ensure failure processing runs below */ 1622 type = SSH2_MSG_REQUEST_FAILURE; 1623 channel_update_permission(ssh, 1624 rfwd->handle, -1); 1625 } else { 1626 rfwd->allocated_port = (int)port; 1627 logit("Allocated port %u for remote " 1628 "forward to %s:%d", 1629 rfwd->allocated_port, rfwd->connect_host, 1630 rfwd->connect_port); 1631 channel_update_permission(ssh, 1632 rfwd->handle, rfwd->allocated_port); 1633 } 1634 } else { 1635 channel_update_permission(ssh, rfwd->handle, -1); 1636 } 1637 } 1638 1639 if (type == SSH2_MSG_REQUEST_FAILURE) { 1640 if (options.exit_on_forward_failure) { 1641 if (rfwd->listen_path != NULL) 1642 fatal("Error: remote port forwarding failed " 1643 "for listen path %s", rfwd->listen_path); 1644 else 1645 fatal("Error: remote port forwarding failed " 1646 "for listen port %d", rfwd->listen_port); 1647 } else { 1648 if (rfwd->listen_path != NULL) 1649 logit("Warning: remote port forwarding failed " 1650 "for listen path %s", rfwd->listen_path); 1651 else 1652 logit("Warning: remote port forwarding failed " 1653 "for listen port %d", rfwd->listen_port); 1654 } 1655 } 1656 if (++remote_forward_confirms_received == options.num_remote_forwards) { 1657 debug("All remote forwarding requests processed"); 1658 if (fork_after_authentication_flag) 1659 fork_postauth(); 1660 } 1661 } 1662 1663 static void 1664 client_cleanup_stdio_fwd(struct ssh *ssh, int id, void *arg) 1665 { 1666 debug("stdio forwarding: done"); 1667 cleanup_exit(0); 1668 } 1669 1670 static void 1671 ssh_stdio_confirm(struct ssh *ssh, int id, int success, void *arg) 1672 { 1673 if (!success) 1674 fatal("stdio forwarding failed"); 1675 } 1676 1677 static void 1678 ssh_init_stdio_forwarding(struct ssh *ssh) 1679 { 1680 Channel *c; 1681 int in, out; 1682 1683 if (options.stdio_forward_host == NULL) 1684 return; 1685 1686 debug3("%s: %s:%d", __func__, options.stdio_forward_host, 1687 options.stdio_forward_port); 1688 1689 if ((in = dup(STDIN_FILENO)) < 0 || 1690 (out = dup(STDOUT_FILENO)) < 0) 1691 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1692 if ((c = channel_connect_stdio_fwd(ssh, options.stdio_forward_host, 1693 options.stdio_forward_port, in, out)) == NULL) 1694 fatal("%s: channel_connect_stdio_fwd failed", __func__); 1695 channel_register_cleanup(ssh, c->self, client_cleanup_stdio_fwd, 0); 1696 channel_register_open_confirm(ssh, c->self, ssh_stdio_confirm, NULL); 1697 } 1698 1699 static void 1700 ssh_init_forwarding(struct ssh *ssh, char **ifname) 1701 { 1702 int success = 0; 1703 int i; 1704 1705 /* Initiate local TCP/IP port forwardings. */ 1706 for (i = 0; i < options.num_local_forwards; i++) { 1707 debug("Local connections to %.200s:%d forwarded to remote " 1708 "address %.200s:%d", 1709 (options.local_forwards[i].listen_path != NULL) ? 1710 options.local_forwards[i].listen_path : 1711 (options.local_forwards[i].listen_host == NULL) ? 1712 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") : 1713 options.local_forwards[i].listen_host, 1714 options.local_forwards[i].listen_port, 1715 (options.local_forwards[i].connect_path != NULL) ? 1716 options.local_forwards[i].connect_path : 1717 options.local_forwards[i].connect_host, 1718 options.local_forwards[i].connect_port); 1719 success += channel_setup_local_fwd_listener(ssh, 1720 &options.local_forwards[i], &options.fwd_opts); 1721 } 1722 if (i > 0 && success != i && options.exit_on_forward_failure) 1723 fatal("Could not request local forwarding."); 1724 if (i > 0 && success == 0) 1725 error("Could not request local forwarding."); 1726 1727 /* Initiate remote TCP/IP port forwardings. */ 1728 for (i = 0; i < options.num_remote_forwards; i++) { 1729 debug("Remote connections from %.200s:%d forwarded to " 1730 "local address %.200s:%d", 1731 (options.remote_forwards[i].listen_path != NULL) ? 1732 options.remote_forwards[i].listen_path : 1733 (options.remote_forwards[i].listen_host == NULL) ? 1734 "LOCALHOST" : options.remote_forwards[i].listen_host, 1735 options.remote_forwards[i].listen_port, 1736 (options.remote_forwards[i].connect_path != NULL) ? 1737 options.remote_forwards[i].connect_path : 1738 options.remote_forwards[i].connect_host, 1739 options.remote_forwards[i].connect_port); 1740 options.remote_forwards[i].handle = 1741 channel_request_remote_forwarding(ssh, 1742 &options.remote_forwards[i]); 1743 if (options.remote_forwards[i].handle < 0) { 1744 if (options.exit_on_forward_failure) 1745 fatal("Could not request remote forwarding."); 1746 else 1747 logit("Warning: Could not request remote " 1748 "forwarding."); 1749 } else { 1750 client_register_global_confirm( 1751 ssh_confirm_remote_forward, 1752 &options.remote_forwards[i]); 1753 } 1754 } 1755 1756 /* Initiate tunnel forwarding. */ 1757 if (options.tun_open != SSH_TUNMODE_NO) { 1758 if ((*ifname = client_request_tun_fwd(ssh, 1759 options.tun_open, options.tun_local, 1760 options.tun_remote)) == NULL) { 1761 if (options.exit_on_forward_failure) 1762 fatal("Could not request tunnel forwarding."); 1763 else 1764 error("Could not request tunnel forwarding."); 1765 } 1766 } 1767 } 1768 1769 static void 1770 check_agent_present(void) 1771 { 1772 int r; 1773 1774 if (options.forward_agent) { 1775 /* Clear agent forwarding if we don't have an agent. */ 1776 if ((r = ssh_get_authentication_socket(NULL)) != 0) { 1777 options.forward_agent = 0; 1778 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1779 debug("ssh_get_authentication_socket: %s", 1780 ssh_err(r)); 1781 } 1782 } 1783 } 1784 1785 static void 1786 ssh_session2_setup(struct ssh *ssh, int id, int success, void *arg) 1787 { 1788 extern char **environ; 1789 const char *display; 1790 int r, interactive = tty_flag; 1791 char *proto = NULL, *data = NULL; 1792 1793 if (!success) 1794 return; /* No need for error message, channels code sens one */ 1795 1796 display = getenv("DISPLAY"); 1797 if (display == NULL && options.forward_x11) 1798 debug("X11 forwarding requested but DISPLAY not set"); 1799 if (options.forward_x11 && client_x11_get_proto(ssh, display, 1800 options.xauth_location, options.forward_x11_trusted, 1801 options.forward_x11_timeout, &proto, &data) == 0) { 1802 /* Request forwarding with authentication spoofing. */ 1803 debug("Requesting X11 forwarding with authentication " 1804 "spoofing."); 1805 x11_request_forwarding_with_spoofing(ssh, id, display, proto, 1806 data, 1); 1807 client_expect_confirm(ssh, id, "X11 forwarding", CONFIRM_WARN); 1808 /* XXX exit_on_forward_failure */ 1809 interactive = 1; 1810 } 1811 1812 check_agent_present(); 1813 if (options.forward_agent) { 1814 debug("Requesting authentication agent forwarding."); 1815 channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0); 1816 if ((r = sshpkt_send(ssh)) != 0) 1817 fatal("%s: %s", __func__, ssh_err(r)); 1818 } 1819 1820 /* Tell the packet module whether this is an interactive session. */ 1821 ssh_packet_set_interactive(ssh, interactive, 1822 options.ip_qos_interactive, options.ip_qos_bulk); 1823 1824 client_session2_setup(ssh, id, tty_flag, subsystem_flag, getenv("TERM"), 1825 NULL, fileno(stdin), command, environ); 1826 } 1827 1828 /* open new channel for a session */ 1829 static int 1830 ssh_session2_open(struct ssh *ssh) 1831 { 1832 Channel *c; 1833 int window, packetmax, in, out, err; 1834 1835 if (stdin_null_flag) { 1836 in = open(_PATH_DEVNULL, O_RDONLY); 1837 } else { 1838 in = dup(STDIN_FILENO); 1839 } 1840 out = dup(STDOUT_FILENO); 1841 err = dup(STDERR_FILENO); 1842 1843 if (in < 0 || out < 0 || err < 0) 1844 fatal("dup() in/out/err failed"); 1845 1846 /* enable nonblocking unless tty */ 1847 if (!isatty(in)) 1848 set_nonblock(in); 1849 if (!isatty(out)) 1850 set_nonblock(out); 1851 if (!isatty(err)) 1852 set_nonblock(err); 1853 1854 window = CHAN_SES_WINDOW_DEFAULT; 1855 packetmax = CHAN_SES_PACKET_DEFAULT; 1856 if (tty_flag) { 1857 window >>= 1; 1858 packetmax >>= 1; 1859 } 1860 c = channel_new(ssh, 1861 "session", SSH_CHANNEL_OPENING, in, out, err, 1862 window, packetmax, CHAN_EXTENDED_WRITE, 1863 "client-session", /*nonblock*/0); 1864 1865 debug3("%s: channel_new: %d", __func__, c->self); 1866 1867 channel_send_open(ssh, c->self); 1868 if (!no_shell_flag) 1869 channel_register_open_confirm(ssh, c->self, 1870 ssh_session2_setup, NULL); 1871 1872 return c->self; 1873 } 1874 1875 static int 1876 ssh_session2(struct ssh *ssh, struct passwd *pw) 1877 { 1878 int r, devnull, id = -1; 1879 char *cp, *tun_fwd_ifname = NULL; 1880 1881 /* XXX should be pre-session */ 1882 if (!options.control_persist) 1883 ssh_init_stdio_forwarding(ssh); 1884 1885 ssh_init_forwarding(ssh, &tun_fwd_ifname); 1886 1887 if (options.local_command != NULL) { 1888 debug3("expanding LocalCommand: %s", options.local_command); 1889 cp = options.local_command; 1890 options.local_command = percent_expand(cp, 1891 "C", conn_hash_hex, 1892 "L", shorthost, 1893 "d", pw->pw_dir, 1894 "h", host, 1895 "i", uidstr, 1896 "l", thishost, 1897 "n", host_arg, 1898 "p", portstr, 1899 "r", options.user, 1900 "u", pw->pw_name, 1901 "T", tun_fwd_ifname == NULL ? "NONE" : tun_fwd_ifname, 1902 (char *)NULL); 1903 debug3("expanded LocalCommand: %s", options.local_command); 1904 free(cp); 1905 } 1906 1907 /* Start listening for multiplex clients */ 1908 if (!ssh_packet_get_mux(ssh)) 1909 muxserver_listen(ssh); 1910 1911 /* 1912 * If we are in control persist mode and have a working mux listen 1913 * socket, then prepare to background ourselves and have a foreground 1914 * client attach as a control slave. 1915 * NB. we must save copies of the flags that we override for 1916 * the backgrounding, since we defer attachment of the slave until 1917 * after the connection is fully established (in particular, 1918 * async rfwd replies have been received for ExitOnForwardFailure). 1919 */ 1920 if (options.control_persist && muxserver_sock != -1) { 1921 ostdin_null_flag = stdin_null_flag; 1922 ono_shell_flag = no_shell_flag; 1923 orequest_tty = options.request_tty; 1924 otty_flag = tty_flag; 1925 stdin_null_flag = 1; 1926 no_shell_flag = 1; 1927 tty_flag = 0; 1928 if (!fork_after_authentication_flag) 1929 need_controlpersist_detach = 1; 1930 fork_after_authentication_flag = 1; 1931 } 1932 /* 1933 * ControlPersist mux listen socket setup failed, attempt the 1934 * stdio forward setup that we skipped earlier. 1935 */ 1936 if (options.control_persist && muxserver_sock == -1) 1937 ssh_init_stdio_forwarding(ssh); 1938 1939 if (!no_shell_flag) 1940 id = ssh_session2_open(ssh); 1941 else { 1942 ssh_packet_set_interactive(ssh, 1943 options.control_master == SSHCTL_MASTER_NO, 1944 options.ip_qos_interactive, options.ip_qos_bulk); 1945 } 1946 1947 /* If we don't expect to open a new session, then disallow it */ 1948 if (options.control_master == SSHCTL_MASTER_NO && 1949 (datafellows & SSH_NEW_OPENSSH)) { 1950 debug("Requesting no-more-sessions@openssh.com"); 1951 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 1952 (r = sshpkt_put_cstring(ssh, 1953 "no-more-sessions@openssh.com")) != 0 || 1954 (r = sshpkt_put_u8(ssh, 0)) != 0 || 1955 (r = sshpkt_send(ssh)) != 0) 1956 fatal("%s: %s", __func__, ssh_err(r)); 1957 } 1958 1959 /* Execute a local command */ 1960 if (options.local_command != NULL && 1961 options.permit_local_command) 1962 ssh_local_cmd(options.local_command); 1963 1964 /* 1965 * stdout is now owned by the session channel; clobber it here 1966 * so future channel closes are propagated to the local fd. 1967 * NB. this can only happen after LocalCommand has completed, 1968 * as it may want to write to stdout. 1969 */ 1970 if (!need_controlpersist_detach) { 1971 if ((devnull = open(_PATH_DEVNULL, O_WRONLY)) == -1) 1972 error("%s: open %s: %s", __func__, 1973 _PATH_DEVNULL, strerror(errno)); 1974 if (dup2(devnull, STDOUT_FILENO) < 0) 1975 fatal("%s: dup2() stdout failed", __func__); 1976 if (devnull > STDERR_FILENO) 1977 close(devnull); 1978 } 1979 1980 /* 1981 * If requested and we are not interested in replies to remote 1982 * forwarding requests, then let ssh continue in the background. 1983 */ 1984 if (fork_after_authentication_flag) { 1985 if (options.exit_on_forward_failure && 1986 options.num_remote_forwards > 0) { 1987 debug("deferring postauth fork until remote forward " 1988 "confirmation received"); 1989 } else 1990 fork_postauth(); 1991 } 1992 1993 return client_loop(ssh, tty_flag, tty_flag ? 1994 options.escape_char : SSH_ESCAPECHAR_NONE, id); 1995 } 1996 1997 /* Loads all IdentityFile and CertificateFile keys */ 1998 static void 1999 load_public_identity_files(struct passwd *pw) 2000 { 2001 char *filename, *cp; 2002 struct sshkey *public; 2003 int i; 2004 u_int n_ids, n_certs; 2005 char *identity_files[SSH_MAX_IDENTITY_FILES]; 2006 struct sshkey *identity_keys[SSH_MAX_IDENTITY_FILES]; 2007 int identity_file_userprovided[SSH_MAX_IDENTITY_FILES]; 2008 char *certificate_files[SSH_MAX_CERTIFICATE_FILES]; 2009 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES]; 2010 int certificate_file_userprovided[SSH_MAX_CERTIFICATE_FILES]; 2011 #ifdef ENABLE_PKCS11 2012 struct sshkey **keys; 2013 int nkeys; 2014 #endif /* PKCS11 */ 2015 2016 n_ids = n_certs = 0; 2017 memset(identity_files, 0, sizeof(identity_files)); 2018 memset(identity_keys, 0, sizeof(identity_keys)); 2019 memset(identity_file_userprovided, 0, 2020 sizeof(identity_file_userprovided)); 2021 memset(certificate_files, 0, sizeof(certificate_files)); 2022 memset(certificates, 0, sizeof(certificates)); 2023 memset(certificate_file_userprovided, 0, 2024 sizeof(certificate_file_userprovided)); 2025 2026 #ifdef ENABLE_PKCS11 2027 if (options.pkcs11_provider != NULL && 2028 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 2029 (pkcs11_init(!options.batch_mode) == 0) && 2030 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 2031 &keys)) > 0) { 2032 for (i = 0; i < nkeys; i++) { 2033 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 2034 sshkey_free(keys[i]); 2035 continue; 2036 } 2037 identity_keys[n_ids] = keys[i]; 2038 identity_files[n_ids] = 2039 xstrdup(options.pkcs11_provider); /* XXX */ 2040 n_ids++; 2041 } 2042 free(keys); 2043 } 2044 #endif /* ENABLE_PKCS11 */ 2045 for (i = 0; i < options.num_identity_files; i++) { 2046 if (n_ids >= SSH_MAX_IDENTITY_FILES || 2047 strcasecmp(options.identity_files[i], "none") == 0) { 2048 free(options.identity_files[i]); 2049 options.identity_files[i] = NULL; 2050 continue; 2051 } 2052 cp = tilde_expand_filename(options.identity_files[i], getuid()); 2053 filename = percent_expand(cp, "d", pw->pw_dir, 2054 "u", pw->pw_name, "l", thishost, "h", host, 2055 "r", options.user, (char *)NULL); 2056 free(cp); 2057 check_load(sshkey_load_public(filename, &public, NULL), 2058 filename, "pubkey"); 2059 debug("identity file %s type %d", filename, 2060 public ? public->type : -1); 2061 free(options.identity_files[i]); 2062 identity_files[n_ids] = filename; 2063 identity_keys[n_ids] = public; 2064 identity_file_userprovided[n_ids] = 2065 options.identity_file_userprovided[i]; 2066 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 2067 continue; 2068 2069 /* 2070 * If no certificates have been explicitly listed then try 2071 * to add the default certificate variant too. 2072 */ 2073 if (options.num_certificate_files != 0) 2074 continue; 2075 xasprintf(&cp, "%s-cert", filename); 2076 check_load(sshkey_load_public(cp, &public, NULL), 2077 filename, "pubkey"); 2078 debug("identity file %s type %d", cp, 2079 public ? public->type : -1); 2080 if (public == NULL) { 2081 free(cp); 2082 continue; 2083 } 2084 if (!sshkey_is_cert(public)) { 2085 debug("%s: key %s type %s is not a certificate", 2086 __func__, cp, sshkey_type(public)); 2087 sshkey_free(public); 2088 free(cp); 2089 continue; 2090 } 2091 /* NB. leave filename pointing to private key */ 2092 identity_files[n_ids] = xstrdup(filename); 2093 identity_keys[n_ids] = public; 2094 identity_file_userprovided[n_ids] = 2095 options.identity_file_userprovided[i]; 2096 n_ids++; 2097 } 2098 2099 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES) 2100 fatal("%s: too many certificates", __func__); 2101 for (i = 0; i < options.num_certificate_files; i++) { 2102 cp = tilde_expand_filename(options.certificate_files[i], 2103 getuid()); 2104 filename = percent_expand(cp, 2105 "d", pw->pw_dir, 2106 "h", host, 2107 "i", uidstr, 2108 "l", thishost, 2109 "r", options.user, 2110 "u", pw->pw_name, 2111 (char *)NULL); 2112 free(cp); 2113 2114 check_load(sshkey_load_public(filename, &public, NULL), 2115 filename, "certificate"); 2116 debug("certificate file %s type %d", filename, 2117 public ? public->type : -1); 2118 free(options.certificate_files[i]); 2119 options.certificate_files[i] = NULL; 2120 if (public == NULL) { 2121 free(filename); 2122 continue; 2123 } 2124 if (!sshkey_is_cert(public)) { 2125 debug("%s: key %s type %s is not a certificate", 2126 __func__, filename, sshkey_type(public)); 2127 sshkey_free(public); 2128 free(filename); 2129 continue; 2130 } 2131 certificate_files[n_certs] = filename; 2132 certificates[n_certs] = public; 2133 certificate_file_userprovided[n_certs] = 2134 options.certificate_file_userprovided[i]; 2135 ++n_certs; 2136 } 2137 2138 options.num_identity_files = n_ids; 2139 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 2140 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 2141 memcpy(options.identity_file_userprovided, 2142 identity_file_userprovided, sizeof(identity_file_userprovided)); 2143 2144 options.num_certificate_files = n_certs; 2145 memcpy(options.certificate_files, 2146 certificate_files, sizeof(certificate_files)); 2147 memcpy(options.certificates, certificates, sizeof(certificates)); 2148 memcpy(options.certificate_file_userprovided, 2149 certificate_file_userprovided, 2150 sizeof(certificate_file_userprovided)); 2151 } 2152 2153 static void 2154 main_sigchld_handler(int sig) 2155 { 2156 int save_errno = errno; 2157 pid_t pid; 2158 int status; 2159 2160 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 2161 (pid < 0 && errno == EINTR)) 2162 ; 2163 errno = save_errno; 2164 } 2165