1 /* $OpenBSD: ssh.c,v 1.594 2023/09/03 23:59:32 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 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 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 <stdarg.h> 69 #include <unistd.h> 70 #include <limits.h> 71 #include <locale.h> 72 73 #include <netinet/in.h> 74 #include <arpa/inet.h> 75 76 #ifdef WITH_OPENSSL 77 #include <openssl/evp.h> 78 #include <openssl/err.h> 79 #endif 80 #include "openbsd-compat/openssl-compat.h" 81 #include "openbsd-compat/sys-queue.h" 82 83 #include "xmalloc.h" 84 #include "ssh.h" 85 #include "ssh2.h" 86 #include "canohost.h" 87 #include "compat.h" 88 #include "cipher.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 /* 130 * Flag indicating that the current process should be backgrounded and 131 * a new mux-client launched in the foreground for ControlPersist. 132 */ 133 static int need_controlpersist_detach = 0; 134 135 /* Copies of flags for ControlPersist foreground mux-client */ 136 static int ostdin_null_flag, osession_type, otty_flag, orequest_tty; 137 static int ofork_after_authentication; 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] [-b bind_address]\n" 184 " [-c cipher_spec] [-D [bind_address:]port] [-E log_file]\n" 185 " [-e escape_char] [-F configfile] [-I pkcs11] [-i identity_file]\n" 186 " [-J destination] [-L address] [-l login_name] [-m mac_spec]\n" 187 " [-O ctl_cmd] [-o option] [-P tag] [-p port] [-Q query_option]\n" 188 " [-R address] [-S ctl_path] [-W host:port] [-w local_tun[:remote_tun]]\n" 189 " destination [command [argument ...]]\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 const char *errstr = NULL; 256 struct addrinfo hints, *res; 257 int gaierr; 258 LogLevel loglevel = SYSLOG_LEVEL_DEBUG1; 259 260 if (port <= 0) 261 port = default_ssh_port(); 262 if (cname != NULL) 263 *cname = '\0'; 264 debug3_f("lookup %s:%d", name, port); 265 266 snprintf(strport, sizeof strport, "%d", port); 267 memset(&hints, 0, sizeof(hints)); 268 hints.ai_family = options.address_family == -1 ? 269 AF_UNSPEC : options.address_family; 270 hints.ai_socktype = SOCK_STREAM; 271 if (cname != NULL) 272 hints.ai_flags = AI_CANONNAME; 273 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 274 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) 275 loglevel = SYSLOG_LEVEL_ERROR; 276 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", 277 __progname, name, ssh_gai_strerror(gaierr)); 278 return NULL; 279 } 280 if (cname != NULL && res->ai_canonname != NULL) { 281 if (!valid_domain(res->ai_canonname, 0, &errstr)) { 282 error("ignoring bad CNAME \"%s\" for host \"%s\": %s", 283 res->ai_canonname, name, errstr); 284 } else if (strlcpy(cname, res->ai_canonname, clen) >= clen) { 285 error_f("host \"%s\" cname \"%s\" too long (max %lu)", 286 name, res->ai_canonname, (u_long)clen); 287 if (clen > 0) 288 *cname = '\0'; 289 } 290 } 291 return res; 292 } 293 294 /* Returns non-zero if name can only be an address and not a hostname */ 295 static int 296 is_addr_fast(const char *name) 297 { 298 return (strchr(name, '%') != NULL || strchr(name, ':') != NULL || 299 strspn(name, "0123456789.") == strlen(name)); 300 } 301 302 /* Returns non-zero if name represents a valid, single address */ 303 static int 304 is_addr(const char *name) 305 { 306 char strport[NI_MAXSERV]; 307 struct addrinfo hints, *res; 308 309 if (is_addr_fast(name)) 310 return 1; 311 312 snprintf(strport, sizeof strport, "%u", default_ssh_port()); 313 memset(&hints, 0, sizeof(hints)); 314 hints.ai_family = options.address_family == -1 ? 315 AF_UNSPEC : options.address_family; 316 hints.ai_socktype = SOCK_STREAM; 317 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 318 if (getaddrinfo(name, strport, &hints, &res) != 0) 319 return 0; 320 if (res == NULL || res->ai_next != NULL) { 321 freeaddrinfo(res); 322 return 0; 323 } 324 freeaddrinfo(res); 325 return 1; 326 } 327 328 /* 329 * Attempt to resolve a numeric host address / port to a single address. 330 * Returns a canonical address string. 331 * Returns NULL on failure. 332 * NB. this function must operate with a options having undefined members. 333 */ 334 static struct addrinfo * 335 resolve_addr(const char *name, int port, char *caddr, size_t clen) 336 { 337 char addr[NI_MAXHOST], strport[NI_MAXSERV]; 338 struct addrinfo hints, *res; 339 int gaierr; 340 341 if (port <= 0) 342 port = default_ssh_port(); 343 snprintf(strport, sizeof strport, "%u", port); 344 memset(&hints, 0, sizeof(hints)); 345 hints.ai_family = options.address_family == -1 ? 346 AF_UNSPEC : options.address_family; 347 hints.ai_socktype = SOCK_STREAM; 348 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 349 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 350 debug2_f("could not resolve name %.100s as address: %s", 351 name, ssh_gai_strerror(gaierr)); 352 return NULL; 353 } 354 if (res == NULL) { 355 debug_f("getaddrinfo %.100s returned no addresses", name); 356 return NULL; 357 } 358 if (res->ai_next != NULL) { 359 debug_f("getaddrinfo %.100s returned multiple addresses", name); 360 goto fail; 361 } 362 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen, 363 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) { 364 debug_f("Could not format address for name %.100s: %s", 365 name, ssh_gai_strerror(gaierr)); 366 goto fail; 367 } 368 if (strlcpy(caddr, addr, clen) >= clen) { 369 error_f("host \"%s\" addr \"%s\" too long (max %lu)", 370 name, addr, (u_long)clen); 371 if (clen > 0) 372 *caddr = '\0'; 373 fail: 374 freeaddrinfo(res); 375 return NULL; 376 } 377 return res; 378 } 379 380 /* 381 * Check whether the cname is a permitted replacement for the hostname 382 * and perform the replacement if it is. 383 * NB. this function must operate with a options having undefined members. 384 */ 385 static int 386 check_follow_cname(int direct, char **namep, const char *cname) 387 { 388 int i; 389 struct allowed_cname *rule; 390 391 if (*cname == '\0' || !config_has_permitted_cnames(&options) || 392 strcmp(*namep, cname) == 0) 393 return 0; 394 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 395 return 0; 396 /* 397 * Don't attempt to canonicalize names that will be interpreted by 398 * a proxy or jump host unless the user specifically requests so. 399 */ 400 if (!direct && 401 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 402 return 0; 403 debug3_f("check \"%s\" CNAME \"%s\"", *namep, cname); 404 for (i = 0; i < options.num_permitted_cnames; i++) { 405 rule = options.permitted_cnames + i; 406 if (match_pattern_list(*namep, rule->source_list, 1) != 1 || 407 match_pattern_list(cname, rule->target_list, 1) != 1) 408 continue; 409 verbose("Canonicalized DNS aliased hostname " 410 "\"%s\" => \"%s\"", *namep, cname); 411 free(*namep); 412 *namep = xstrdup(cname); 413 return 1; 414 } 415 return 0; 416 } 417 418 /* 419 * Attempt to resolve the supplied hostname after applying the user's 420 * canonicalization rules. Returns the address list for the host or NULL 421 * if no name was found after canonicalization. 422 * NB. this function must operate with a options having undefined members. 423 */ 424 static struct addrinfo * 425 resolve_canonicalize(char **hostp, int port) 426 { 427 int i, direct, ndots; 428 char *cp, *fullhost, newname[NI_MAXHOST]; 429 struct addrinfo *addrs; 430 431 /* 432 * Attempt to canonicalise addresses, regardless of 433 * whether hostname canonicalisation was requested 434 */ 435 if ((addrs = resolve_addr(*hostp, port, 436 newname, sizeof(newname))) != NULL) { 437 debug2_f("hostname %.100s is address", *hostp); 438 if (strcasecmp(*hostp, newname) != 0) { 439 debug2_f("canonicalised address \"%s\" => \"%s\"", 440 *hostp, newname); 441 free(*hostp); 442 *hostp = xstrdup(newname); 443 } 444 return addrs; 445 } 446 447 /* 448 * If this looks like an address but didn't parse as one, it might 449 * be an address with an invalid interface scope. Skip further 450 * attempts at canonicalisation. 451 */ 452 if (is_addr_fast(*hostp)) { 453 debug_f("hostname %.100s is an unrecognised address", *hostp); 454 return NULL; 455 } 456 457 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 458 return NULL; 459 460 /* 461 * Don't attempt to canonicalize names that will be interpreted by 462 * a proxy unless the user specifically requests so. 463 */ 464 direct = option_clear_or_none(options.proxy_command) && 465 option_clear_or_none(options.jump_host); 466 if (!direct && 467 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 468 return NULL; 469 470 /* If domain name is anchored, then resolve it now */ 471 if ((*hostp)[strlen(*hostp) - 1] == '.') { 472 debug3_f("name is fully qualified"); 473 fullhost = xstrdup(*hostp); 474 if ((addrs = resolve_host(fullhost, port, 0, 475 newname, sizeof(newname))) != NULL) 476 goto found; 477 free(fullhost); 478 goto notfound; 479 } 480 481 /* Don't apply canonicalization to sufficiently-qualified hostnames */ 482 ndots = 0; 483 for (cp = *hostp; *cp != '\0'; cp++) { 484 if (*cp == '.') 485 ndots++; 486 } 487 if (ndots > options.canonicalize_max_dots) { 488 debug3_f("not canonicalizing hostname \"%s\" (max dots %d)", 489 *hostp, options.canonicalize_max_dots); 490 return NULL; 491 } 492 /* Attempt each supplied suffix */ 493 for (i = 0; i < options.num_canonical_domains; i++) { 494 if (strcasecmp(options.canonical_domains[i], "none") == 0) 495 break; 496 xasprintf(&fullhost, "%s.%s.", *hostp, 497 options.canonical_domains[i]); 498 debug3_f("attempting \"%s\" => \"%s\"", *hostp, fullhost); 499 if ((addrs = resolve_host(fullhost, port, 0, 500 newname, sizeof(newname))) == NULL) { 501 free(fullhost); 502 continue; 503 } 504 found: 505 /* Remove trailing '.' */ 506 fullhost[strlen(fullhost) - 1] = '\0'; 507 /* Follow CNAME if requested */ 508 if (!check_follow_cname(direct, &fullhost, newname)) { 509 debug("Canonicalized hostname \"%s\" => \"%s\"", 510 *hostp, fullhost); 511 } 512 free(*hostp); 513 *hostp = fullhost; 514 return addrs; 515 } 516 notfound: 517 if (!options.canonicalize_fallback_local) 518 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); 519 debug2_f("host %s not found in any suffix", *hostp); 520 return NULL; 521 } 522 523 /* 524 * Check the result of hostkey loading, ignoring some errors and either 525 * discarding the key or fatal()ing for others. 526 */ 527 static void 528 check_load(int r, struct sshkey **k, const char *path, const char *message) 529 { 530 switch (r) { 531 case 0: 532 /* Check RSA keys size and discard if undersized */ 533 if (k != NULL && *k != NULL && 534 (r = sshkey_check_rsa_length(*k, 535 options.required_rsa_size)) != 0) { 536 error_r(r, "load %s \"%s\"", message, path); 537 free(*k); 538 *k = NULL; 539 } 540 break; 541 case SSH_ERR_INTERNAL_ERROR: 542 case SSH_ERR_ALLOC_FAIL: 543 fatal_r(r, "load %s \"%s\"", message, path); 544 case SSH_ERR_SYSTEM_ERROR: 545 /* Ignore missing files */ 546 if (errno == ENOENT) 547 break; 548 /* FALLTHROUGH */ 549 default: 550 error_r(r, "load %s \"%s\"", message, path); 551 break; 552 } 553 } 554 555 /* 556 * Read per-user configuration file. Ignore the system wide config 557 * file if the user specifies a config file on the command line. 558 */ 559 static void 560 process_config_files(const char *host_name, struct passwd *pw, int final_pass, 561 int *want_final_pass) 562 { 563 char buf[PATH_MAX]; 564 int r; 565 566 if (config != NULL) { 567 if (strcasecmp(config, "none") != 0 && 568 !read_config_file(config, pw, host, host_name, &options, 569 SSHCONF_USERCONF | (final_pass ? SSHCONF_FINAL : 0), 570 want_final_pass)) 571 fatal("Can't open user config file %.100s: " 572 "%.100s", config, strerror(errno)); 573 } else { 574 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 575 _PATH_SSH_USER_CONFFILE); 576 if (r > 0 && (size_t)r < sizeof(buf)) 577 (void)read_config_file(buf, pw, host, host_name, 578 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF | 579 (final_pass ? SSHCONF_FINAL : 0), want_final_pass); 580 581 /* Read systemwide configuration file after user config. */ 582 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, 583 host, host_name, &options, 584 final_pass ? SSHCONF_FINAL : 0, want_final_pass); 585 } 586 } 587 588 /* Rewrite the port number in an addrinfo list of addresses */ 589 static void 590 set_addrinfo_port(struct addrinfo *addrs, int port) 591 { 592 struct addrinfo *addr; 593 594 for (addr = addrs; addr != NULL; addr = addr->ai_next) { 595 switch (addr->ai_family) { 596 case AF_INET: 597 ((struct sockaddr_in *)addr->ai_addr)-> 598 sin_port = htons(port); 599 break; 600 case AF_INET6: 601 ((struct sockaddr_in6 *)addr->ai_addr)-> 602 sin6_port = htons(port); 603 break; 604 } 605 } 606 } 607 608 static void 609 ssh_conn_info_free(struct ssh_conn_info *cinfo) 610 { 611 if (cinfo == NULL) 612 return; 613 free(cinfo->conn_hash_hex); 614 free(cinfo->shorthost); 615 free(cinfo->uidstr); 616 free(cinfo->keyalias); 617 free(cinfo->thishost); 618 free(cinfo->host_arg); 619 free(cinfo->portstr); 620 free(cinfo->remhost); 621 free(cinfo->remuser); 622 free(cinfo->homedir); 623 free(cinfo->locuser); 624 free(cinfo); 625 } 626 627 /* 628 * Main program for the ssh client. 629 */ 630 int 631 main(int ac, char **av) 632 { 633 struct ssh *ssh = NULL; 634 int i, r, opt, exit_status, use_syslog, direct, timeout_ms; 635 int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0; 636 char *p, *cp, *line, *argv0, *logfile; 637 char cname[NI_MAXHOST], thishost[NI_MAXHOST]; 638 struct stat st; 639 struct passwd *pw; 640 extern int optind, optreset; 641 extern char *optarg; 642 struct Forward fwd; 643 struct addrinfo *addrs = NULL; 644 size_t n, len; 645 u_int j; 646 struct ssh_conn_info *cinfo = NULL; 647 648 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 649 sanitise_stdfd(); 650 651 /* 652 * Discard other fds that are hanging around. These can cause problem 653 * with backgrounded ssh processes started by ControlPersist. 654 */ 655 closefrom(STDERR_FILENO + 1); 656 657 __progname = ssh_get_progname(av[0]); 658 659 #ifndef HAVE_SETPROCTITLE 660 /* Prepare for later setproctitle emulation */ 661 /* Save argv so it isn't clobbered by setproctitle() emulation */ 662 saved_av = xcalloc(ac + 1, sizeof(*saved_av)); 663 for (i = 0; i < ac; i++) 664 saved_av[i] = xstrdup(av[i]); 665 saved_av[i] = NULL; 666 compat_init_setproctitle(ac, av); 667 av = saved_av; 668 #endif 669 670 seed_rng(); 671 672 /* Get user data. */ 673 pw = getpwuid(getuid()); 674 if (!pw) { 675 logit("No user exists for uid %lu", (u_long)getuid()); 676 exit(255); 677 } 678 /* Take a copy of the returned structure. */ 679 pw = pwcopy(pw); 680 681 /* 682 * Set our umask to something reasonable, as some files are created 683 * with the default umask. This will make them world-readable but 684 * writable only by the owner, which is ok for all files for which we 685 * don't set the modes explicitly. 686 */ 687 umask(022 | umask(077)); 688 689 msetlocale(); 690 691 /* 692 * Initialize option structure to indicate that no values have been 693 * set. 694 */ 695 initialize_options(&options); 696 697 /* 698 * Prepare main ssh transport/connection structures 699 */ 700 if ((ssh = ssh_alloc_session_state()) == NULL) 701 fatal("Couldn't allocate session state"); 702 channel_init_channels(ssh); 703 704 /* Parse command-line arguments. */ 705 host = NULL; 706 use_syslog = 0; 707 logfile = NULL; 708 argv0 = av[0]; 709 710 again: 711 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 712 "AB:CD:E:F:GI:J:KL:MNO:P:Q:R:S:TVw:W:XYy")) != -1) { /* HUZdhjruz */ 713 switch (opt) { 714 case '1': 715 fatal("SSH protocol v.1 is no longer supported"); 716 break; 717 case '2': 718 /* Ignored */ 719 break; 720 case '4': 721 options.address_family = AF_INET; 722 break; 723 case '6': 724 options.address_family = AF_INET6; 725 break; 726 case 'n': 727 options.stdin_null = 1; 728 break; 729 case 'f': 730 options.fork_after_authentication = 1; 731 options.stdin_null = 1; 732 break; 733 case 'x': 734 options.forward_x11 = 0; 735 break; 736 case 'X': 737 options.forward_x11 = 1; 738 break; 739 case 'y': 740 use_syslog = 1; 741 break; 742 case 'E': 743 logfile = optarg; 744 break; 745 case 'G': 746 config_test = 1; 747 break; 748 case 'Y': 749 options.forward_x11 = 1; 750 options.forward_x11_trusted = 1; 751 break; 752 case 'g': 753 options.fwd_opts.gateway_ports = 1; 754 break; 755 case 'O': 756 if (options.stdio_forward_host != NULL) 757 fatal("Cannot specify multiplexing " 758 "command with -W"); 759 else if (muxclient_command != 0) 760 fatal("Multiplexing command already specified"); 761 if (strcmp(optarg, "check") == 0) 762 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 763 else if (strcmp(optarg, "forward") == 0) 764 muxclient_command = SSHMUX_COMMAND_FORWARD; 765 else if (strcmp(optarg, "exit") == 0) 766 muxclient_command = SSHMUX_COMMAND_TERMINATE; 767 else if (strcmp(optarg, "stop") == 0) 768 muxclient_command = SSHMUX_COMMAND_STOP; 769 else if (strcmp(optarg, "cancel") == 0) 770 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 771 else if (strcmp(optarg, "proxy") == 0) 772 muxclient_command = SSHMUX_COMMAND_PROXY; 773 else 774 fatal("Invalid multiplex command."); 775 break; 776 case 'P': 777 if (options.tag == NULL) 778 options.tag = xstrdup(optarg); 779 break; 780 case 'Q': 781 cp = NULL; 782 if (strcmp(optarg, "cipher") == 0 || 783 strcasecmp(optarg, "Ciphers") == 0) 784 cp = cipher_alg_list('\n', 0); 785 else if (strcmp(optarg, "cipher-auth") == 0) 786 cp = cipher_alg_list('\n', 1); 787 else if (strcmp(optarg, "mac") == 0 || 788 strcasecmp(optarg, "MACs") == 0) 789 cp = mac_alg_list('\n'); 790 else if (strcmp(optarg, "kex") == 0 || 791 strcasecmp(optarg, "KexAlgorithms") == 0) 792 cp = kex_alg_list('\n'); 793 else if (strcmp(optarg, "key") == 0) 794 cp = sshkey_alg_list(0, 0, 0, '\n'); 795 else if (strcmp(optarg, "key-cert") == 0) 796 cp = sshkey_alg_list(1, 0, 0, '\n'); 797 else if (strcmp(optarg, "key-plain") == 0) 798 cp = sshkey_alg_list(0, 1, 0, '\n'); 799 else if (strcmp(optarg, "key-ca-sign") == 0 || 800 strcasecmp(optarg, "CASignatureAlgorithms") == 0) 801 cp = sshkey_alg_list(0, 1, 1, '\n'); 802 else if (strcmp(optarg, "key-sig") == 0 || 803 strcasecmp(optarg, "PubkeyAcceptedKeyTypes") == 0 || /* deprecated name */ 804 strcasecmp(optarg, "PubkeyAcceptedAlgorithms") == 0 || 805 strcasecmp(optarg, "HostKeyAlgorithms") == 0 || 806 strcasecmp(optarg, "HostbasedKeyTypes") == 0 || /* deprecated name */ 807 strcasecmp(optarg, "HostbasedAcceptedKeyTypes") == 0 || /* deprecated name */ 808 strcasecmp(optarg, "HostbasedAcceptedAlgorithms") == 0) 809 cp = sshkey_alg_list(0, 0, 1, '\n'); 810 else if (strcmp(optarg, "sig") == 0) 811 cp = sshkey_alg_list(0, 1, 1, '\n'); 812 else if (strcmp(optarg, "protocol-version") == 0) 813 cp = xstrdup("2"); 814 else if (strcmp(optarg, "compression") == 0) { 815 cp = xstrdup(compression_alg_list(0)); 816 len = strlen(cp); 817 for (n = 0; n < len; n++) 818 if (cp[n] == ',') 819 cp[n] = '\n'; 820 } else if (strcmp(optarg, "help") == 0) { 821 cp = xstrdup( 822 "cipher\ncipher-auth\ncompression\nkex\n" 823 "key\nkey-cert\nkey-plain\nkey-sig\nmac\n" 824 "protocol-version\nsig"); 825 } 826 if (cp == NULL) 827 fatal("Unsupported query \"%s\"", optarg); 828 printf("%s\n", cp); 829 free(cp); 830 exit(0); 831 break; 832 case 'a': 833 options.forward_agent = 0; 834 break; 835 case 'A': 836 options.forward_agent = 1; 837 break; 838 case 'k': 839 options.gss_deleg_creds = 0; 840 break; 841 case 'K': 842 options.gss_authentication = 1; 843 options.gss_deleg_creds = 1; 844 break; 845 case 'i': 846 p = tilde_expand_filename(optarg, getuid()); 847 if (stat(p, &st) == -1) 848 fprintf(stderr, "Warning: Identity file %s " 849 "not accessible: %s.\n", p, 850 strerror(errno)); 851 else 852 add_identity_file(&options, NULL, p, 1); 853 free(p); 854 break; 855 case 'I': 856 #ifdef ENABLE_PKCS11 857 free(options.pkcs11_provider); 858 options.pkcs11_provider = xstrdup(optarg); 859 #else 860 fprintf(stderr, "no support for PKCS#11.\n"); 861 #endif 862 break; 863 case 'J': 864 if (options.jump_host != NULL) { 865 fatal("Only a single -J option is permitted " 866 "(use commas to separate multiple " 867 "jump hops)"); 868 } 869 if (options.proxy_command != NULL) 870 fatal("Cannot specify -J with ProxyCommand"); 871 if (parse_jump(optarg, &options, 1) == -1) 872 fatal("Invalid -J argument"); 873 options.proxy_command = xstrdup("none"); 874 break; 875 case 't': 876 if (options.request_tty == REQUEST_TTY_YES) 877 options.request_tty = REQUEST_TTY_FORCE; 878 else 879 options.request_tty = REQUEST_TTY_YES; 880 break; 881 case 'v': 882 if (debug_flag == 0) { 883 debug_flag = 1; 884 options.log_level = SYSLOG_LEVEL_DEBUG1; 885 } else { 886 if (options.log_level < SYSLOG_LEVEL_DEBUG3) { 887 debug_flag++; 888 options.log_level++; 889 } 890 } 891 break; 892 case 'V': 893 fprintf(stderr, "%s, %s\n", 894 SSH_RELEASE, SSH_OPENSSL_VERSION); 895 exit(0); 896 break; 897 case 'w': 898 if (options.tun_open == -1) 899 options.tun_open = SSH_TUNMODE_DEFAULT; 900 options.tun_local = a2tun(optarg, &options.tun_remote); 901 if (options.tun_local == SSH_TUNID_ERR) { 902 fprintf(stderr, 903 "Bad tun device '%s'\n", optarg); 904 exit(255); 905 } 906 break; 907 case 'W': 908 if (options.stdio_forward_host != NULL) 909 fatal("stdio forward already specified"); 910 if (muxclient_command != 0) 911 fatal("Cannot specify stdio forward with -O"); 912 if (parse_forward(&fwd, optarg, 1, 0)) { 913 options.stdio_forward_host = 914 fwd.listen_port == PORT_STREAMLOCAL ? 915 fwd.listen_path : fwd.listen_host; 916 options.stdio_forward_port = fwd.listen_port; 917 free(fwd.connect_host); 918 } else { 919 fprintf(stderr, 920 "Bad stdio forwarding specification '%s'\n", 921 optarg); 922 exit(255); 923 } 924 options.request_tty = REQUEST_TTY_NO; 925 options.session_type = SESSION_TYPE_NONE; 926 break; 927 case 'q': 928 options.log_level = SYSLOG_LEVEL_QUIET; 929 break; 930 case 'e': 931 if (optarg[0] == '^' && optarg[2] == 0 && 932 (u_char) optarg[1] >= 64 && 933 (u_char) optarg[1] < 128) 934 options.escape_char = (u_char) optarg[1] & 31; 935 else if (strlen(optarg) == 1) 936 options.escape_char = (u_char) optarg[0]; 937 else if (strcmp(optarg, "none") == 0) 938 options.escape_char = SSH_ESCAPECHAR_NONE; 939 else { 940 fprintf(stderr, "Bad escape character '%s'.\n", 941 optarg); 942 exit(255); 943 } 944 break; 945 case 'c': 946 if (!ciphers_valid(*optarg == '+' || *optarg == '^' ? 947 optarg + 1 : optarg)) { 948 fprintf(stderr, "Unknown cipher type '%s'\n", 949 optarg); 950 exit(255); 951 } 952 free(options.ciphers); 953 options.ciphers = xstrdup(optarg); 954 break; 955 case 'm': 956 if (mac_valid(optarg)) { 957 free(options.macs); 958 options.macs = xstrdup(optarg); 959 } else { 960 fprintf(stderr, "Unknown mac type '%s'\n", 961 optarg); 962 exit(255); 963 } 964 break; 965 case 'M': 966 if (options.control_master == SSHCTL_MASTER_YES) 967 options.control_master = SSHCTL_MASTER_ASK; 968 else 969 options.control_master = SSHCTL_MASTER_YES; 970 break; 971 case 'p': 972 if (options.port == -1) { 973 options.port = a2port(optarg); 974 if (options.port <= 0) { 975 fprintf(stderr, "Bad port '%s'\n", 976 optarg); 977 exit(255); 978 } 979 } 980 break; 981 case 'l': 982 if (options.user == NULL) 983 options.user = optarg; 984 break; 985 986 case 'L': 987 if (parse_forward(&fwd, optarg, 0, 0)) 988 add_local_forward(&options, &fwd); 989 else { 990 fprintf(stderr, 991 "Bad local forwarding specification '%s'\n", 992 optarg); 993 exit(255); 994 } 995 break; 996 997 case 'R': 998 if (parse_forward(&fwd, optarg, 0, 1) || 999 parse_forward(&fwd, optarg, 1, 1)) { 1000 add_remote_forward(&options, &fwd); 1001 } else { 1002 fprintf(stderr, 1003 "Bad remote forwarding specification " 1004 "'%s'\n", optarg); 1005 exit(255); 1006 } 1007 break; 1008 1009 case 'D': 1010 if (parse_forward(&fwd, optarg, 1, 0)) { 1011 add_local_forward(&options, &fwd); 1012 } else { 1013 fprintf(stderr, 1014 "Bad dynamic forwarding specification " 1015 "'%s'\n", optarg); 1016 exit(255); 1017 } 1018 break; 1019 1020 case 'C': 1021 #ifdef WITH_ZLIB 1022 options.compression = 1; 1023 #else 1024 error("Compression not supported, disabling."); 1025 #endif 1026 break; 1027 case 'N': 1028 if (options.session_type != -1 && 1029 options.session_type != SESSION_TYPE_NONE) 1030 fatal("Cannot specify -N with -s/SessionType"); 1031 options.session_type = SESSION_TYPE_NONE; 1032 options.request_tty = REQUEST_TTY_NO; 1033 break; 1034 case 'T': 1035 options.request_tty = REQUEST_TTY_NO; 1036 break; 1037 case 'o': 1038 line = xstrdup(optarg); 1039 if (process_config_line(&options, pw, 1040 host ? host : "", host ? host : "", line, 1041 "command-line", 0, NULL, SSHCONF_USERCONF) != 0) 1042 exit(255); 1043 free(line); 1044 break; 1045 case 's': 1046 if (options.session_type != -1 && 1047 options.session_type != SESSION_TYPE_SUBSYSTEM) 1048 fatal("Cannot specify -s with -N/SessionType"); 1049 options.session_type = SESSION_TYPE_SUBSYSTEM; 1050 break; 1051 case 'S': 1052 free(options.control_path); 1053 options.control_path = xstrdup(optarg); 1054 break; 1055 case 'b': 1056 options.bind_address = optarg; 1057 break; 1058 case 'B': 1059 options.bind_interface = optarg; 1060 break; 1061 case 'F': 1062 config = optarg; 1063 break; 1064 default: 1065 usage(); 1066 } 1067 } 1068 1069 if (optind > 1 && strcmp(av[optind - 1], "--") == 0) 1070 opt_terminated = 1; 1071 1072 ac -= optind; 1073 av += optind; 1074 1075 if (ac > 0 && !host) { 1076 int tport; 1077 char *tuser; 1078 switch (parse_ssh_uri(*av, &tuser, &host, &tport)) { 1079 case -1: 1080 usage(); 1081 break; 1082 case 0: 1083 if (options.user == NULL) { 1084 options.user = tuser; 1085 tuser = NULL; 1086 } 1087 free(tuser); 1088 if (options.port == -1 && tport != -1) 1089 options.port = tport; 1090 break; 1091 default: 1092 p = xstrdup(*av); 1093 cp = strrchr(p, '@'); 1094 if (cp != NULL) { 1095 if (cp == p) 1096 usage(); 1097 if (options.user == NULL) { 1098 options.user = p; 1099 p = NULL; 1100 } 1101 *cp++ = '\0'; 1102 host = xstrdup(cp); 1103 free(p); 1104 } else 1105 host = p; 1106 break; 1107 } 1108 if (ac > 1 && !opt_terminated) { 1109 optind = optreset = 1; 1110 goto again; 1111 } 1112 ac--, av++; 1113 } 1114 1115 /* Check that we got a host name. */ 1116 if (!host) 1117 usage(); 1118 1119 options.host_arg = xstrdup(host); 1120 1121 /* Initialize the command to execute on remote host. */ 1122 if ((command = sshbuf_new()) == NULL) 1123 fatal("sshbuf_new failed"); 1124 1125 /* 1126 * Save the command to execute on the remote host in a buffer. There 1127 * is no limit on the length of the command, except by the maximum 1128 * packet size. Also sets the tty flag if there is no command. 1129 */ 1130 if (!ac) { 1131 /* No command specified - execute shell on a tty. */ 1132 if (options.session_type == SESSION_TYPE_SUBSYSTEM) { 1133 fprintf(stderr, 1134 "You must specify a subsystem to invoke.\n"); 1135 usage(); 1136 } 1137 } else { 1138 /* A command has been specified. Store it into the buffer. */ 1139 for (i = 0; i < ac; i++) { 1140 if ((r = sshbuf_putf(command, "%s%s", 1141 i ? " " : "", av[i])) != 0) 1142 fatal_fr(r, "buffer error"); 1143 } 1144 } 1145 1146 ssh_signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 1147 1148 /* 1149 * Initialize "log" output. Since we are the client all output 1150 * goes to stderr unless otherwise specified by -y or -E. 1151 */ 1152 if (use_syslog && logfile != NULL) 1153 fatal("Can't specify both -y and -E"); 1154 if (logfile != NULL) 1155 log_redirect_stderr_to(logfile); 1156 log_init(argv0, 1157 options.log_level == SYSLOG_LEVEL_NOT_SET ? 1158 SYSLOG_LEVEL_INFO : options.log_level, 1159 options.log_facility == SYSLOG_FACILITY_NOT_SET ? 1160 SYSLOG_FACILITY_USER : options.log_facility, 1161 !use_syslog); 1162 1163 if (debug_flag) 1164 logit("%s, %s", SSH_RELEASE, SSH_OPENSSL_VERSION); 1165 1166 /* Parse the configuration files */ 1167 process_config_files(options.host_arg, pw, 0, &want_final_pass); 1168 if (want_final_pass) 1169 debug("configuration requests final Match pass"); 1170 1171 /* Hostname canonicalisation needs a few options filled. */ 1172 fill_default_options_for_canonicalization(&options); 1173 1174 /* If the user has replaced the hostname then take it into use now */ 1175 if (options.hostname != NULL) { 1176 /* NB. Please keep in sync with readconf.c:match_cfg_line() */ 1177 cp = percent_expand(options.hostname, 1178 "h", host, (char *)NULL); 1179 free(host); 1180 host = cp; 1181 free(options.hostname); 1182 options.hostname = xstrdup(host); 1183 } 1184 1185 /* Don't lowercase addresses, they will be explicitly canonicalised */ 1186 if ((was_addr = is_addr(host)) == 0) 1187 lowercase(host); 1188 1189 /* 1190 * Try to canonicalize if requested by configuration or the 1191 * hostname is an address. 1192 */ 1193 if (options.canonicalize_hostname != SSH_CANONICALISE_NO || was_addr) 1194 addrs = resolve_canonicalize(&host, options.port); 1195 1196 /* 1197 * If CanonicalizePermittedCNAMEs have been specified but 1198 * other canonicalization did not happen (by not being requested 1199 * or by failing with fallback) then the hostname may still be changed 1200 * as a result of CNAME following. 1201 * 1202 * Try to resolve the bare hostname name using the system resolver's 1203 * usual search rules and then apply the CNAME follow rules. 1204 * 1205 * Skip the lookup if a ProxyCommand is being used unless the user 1206 * has specifically requested canonicalisation for this case via 1207 * CanonicalizeHostname=always 1208 */ 1209 direct = option_clear_or_none(options.proxy_command) && 1210 option_clear_or_none(options.jump_host); 1211 if (addrs == NULL && config_has_permitted_cnames(&options) && (direct || 1212 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { 1213 if ((addrs = resolve_host(host, options.port, 1214 direct, cname, sizeof(cname))) == NULL) { 1215 /* Don't fatal proxied host names not in the DNS */ 1216 if (direct) 1217 cleanup_exit(255); /* logged in resolve_host */ 1218 } else 1219 check_follow_cname(direct, &host, cname); 1220 } 1221 1222 /* 1223 * If canonicalisation is enabled then re-parse the configuration 1224 * files as new stanzas may match. 1225 */ 1226 if (options.canonicalize_hostname != 0 && !want_final_pass) { 1227 debug("hostname canonicalisation enabled, " 1228 "will re-parse configuration"); 1229 want_final_pass = 1; 1230 } 1231 1232 if (want_final_pass) { 1233 debug("re-parsing configuration"); 1234 free(options.hostname); 1235 options.hostname = xstrdup(host); 1236 process_config_files(options.host_arg, pw, 1, NULL); 1237 /* 1238 * Address resolution happens early with canonicalisation 1239 * enabled and the port number may have changed since, so 1240 * reset it in address list 1241 */ 1242 if (addrs != NULL && options.port > 0) 1243 set_addrinfo_port(addrs, options.port); 1244 } 1245 1246 /* Fill configuration defaults. */ 1247 if (fill_default_options(&options) != 0) 1248 cleanup_exit(255); 1249 1250 if (options.user == NULL) 1251 options.user = xstrdup(pw->pw_name); 1252 1253 /* 1254 * If ProxyJump option specified, then construct a ProxyCommand now. 1255 */ 1256 if (options.jump_host != NULL) { 1257 char port_s[8]; 1258 const char *jumpuser = options.jump_user, *sshbin = argv0; 1259 int port = options.port, jumpport = options.jump_port; 1260 1261 if (port <= 0) 1262 port = default_ssh_port(); 1263 if (jumpport <= 0) 1264 jumpport = default_ssh_port(); 1265 if (jumpuser == NULL) 1266 jumpuser = options.user; 1267 if (strcmp(options.jump_host, host) == 0 && port == jumpport && 1268 strcmp(options.user, jumpuser) == 0) 1269 fatal("jumphost loop via %s", options.jump_host); 1270 1271 /* 1272 * Try to use SSH indicated by argv[0], but fall back to 1273 * "ssh" if it appears unavailable. 1274 */ 1275 if (strchr(argv0, '/') != NULL && access(argv0, X_OK) != 0) 1276 sshbin = "ssh"; 1277 1278 /* Consistency check */ 1279 if (options.proxy_command != NULL) 1280 fatal("inconsistent options: ProxyCommand+ProxyJump"); 1281 /* Never use FD passing for ProxyJump */ 1282 options.proxy_use_fdpass = 0; 1283 snprintf(port_s, sizeof(port_s), "%d", options.jump_port); 1284 xasprintf(&options.proxy_command, 1285 "%s%s%s%s%s%s%s%s%s%s%.*s -W '[%%h]:%%p' %s", 1286 sshbin, 1287 /* Optional "-l user" argument if jump_user set */ 1288 options.jump_user == NULL ? "" : " -l ", 1289 options.jump_user == NULL ? "" : options.jump_user, 1290 /* Optional "-p port" argument if jump_port set */ 1291 options.jump_port <= 0 ? "" : " -p ", 1292 options.jump_port <= 0 ? "" : port_s, 1293 /* Optional additional jump hosts ",..." */ 1294 options.jump_extra == NULL ? "" : " -J ", 1295 options.jump_extra == NULL ? "" : options.jump_extra, 1296 /* Optional "-F" argument if -F specified */ 1297 config == NULL ? "" : " -F ", 1298 config == NULL ? "" : config, 1299 /* Optional "-v" arguments if -v set */ 1300 debug_flag ? " -" : "", 1301 debug_flag, "vvv", 1302 /* Mandatory hostname */ 1303 options.jump_host); 1304 debug("Setting implicit ProxyCommand from ProxyJump: %s", 1305 options.proxy_command); 1306 } 1307 1308 if (options.port == 0) 1309 options.port = default_ssh_port(); 1310 channel_set_af(ssh, options.address_family); 1311 1312 /* Tidy and check options */ 1313 if (options.host_key_alias != NULL) 1314 lowercase(options.host_key_alias); 1315 if (options.proxy_command != NULL && 1316 strcmp(options.proxy_command, "-") == 0 && 1317 options.proxy_use_fdpass) 1318 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); 1319 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 1320 if (options.control_persist && options.control_path != NULL) { 1321 debug("UpdateHostKeys=ask is incompatible with " 1322 "ControlPersist; disabling"); 1323 options.update_hostkeys = 0; 1324 } else if (sshbuf_len(command) != 0 || 1325 options.remote_command != NULL || 1326 options.request_tty == REQUEST_TTY_NO) { 1327 debug("UpdateHostKeys=ask is incompatible with " 1328 "remote command execution; disabling"); 1329 options.update_hostkeys = 0; 1330 } else if (options.log_level < SYSLOG_LEVEL_INFO) { 1331 /* no point logging anything; user won't see it */ 1332 options.update_hostkeys = 0; 1333 } 1334 } 1335 if (options.connection_attempts <= 0) 1336 fatal("Invalid number of ConnectionAttempts"); 1337 1338 if (sshbuf_len(command) != 0 && options.remote_command != NULL) 1339 fatal("Cannot execute command-line and remote command."); 1340 1341 /* Cannot fork to background if no command. */ 1342 if (options.fork_after_authentication && sshbuf_len(command) == 0 && 1343 options.remote_command == NULL && 1344 options.session_type != SESSION_TYPE_NONE) 1345 fatal("Cannot fork into background without a command " 1346 "to execute."); 1347 1348 /* reinit */ 1349 log_init(argv0, options.log_level, options.log_facility, !use_syslog); 1350 for (j = 0; j < options.num_log_verbose; j++) { 1351 if (strcasecmp(options.log_verbose[j], "none") == 0) 1352 break; 1353 log_verbose_add(options.log_verbose[j]); 1354 } 1355 1356 if (options.request_tty == REQUEST_TTY_YES || 1357 options.request_tty == REQUEST_TTY_FORCE) 1358 tty_flag = 1; 1359 1360 /* Allocate a tty by default if no command specified. */ 1361 if (sshbuf_len(command) == 0 && options.remote_command == NULL) 1362 tty_flag = options.request_tty != REQUEST_TTY_NO; 1363 1364 /* Force no tty */ 1365 if (options.request_tty == REQUEST_TTY_NO || 1366 (muxclient_command && muxclient_command != SSHMUX_COMMAND_PROXY) || 1367 options.session_type == SESSION_TYPE_NONE) 1368 tty_flag = 0; 1369 /* Do not allocate a tty if stdin is not a tty. */ 1370 if ((!isatty(fileno(stdin)) || options.stdin_null) && 1371 options.request_tty != REQUEST_TTY_FORCE) { 1372 if (tty_flag) 1373 logit("Pseudo-terminal will not be allocated because " 1374 "stdin is not a terminal."); 1375 tty_flag = 0; 1376 } 1377 1378 /* Set up strings used to percent_expand() arguments */ 1379 cinfo = xcalloc(1, sizeof(*cinfo)); 1380 if (gethostname(thishost, sizeof(thishost)) == -1) 1381 fatal("gethostname: %s", strerror(errno)); 1382 cinfo->thishost = xstrdup(thishost); 1383 thishost[strcspn(thishost, ".")] = '\0'; 1384 cinfo->shorthost = xstrdup(thishost); 1385 xasprintf(&cinfo->portstr, "%d", options.port); 1386 xasprintf(&cinfo->uidstr, "%llu", 1387 (unsigned long long)pw->pw_uid); 1388 cinfo->keyalias = xstrdup(options.host_key_alias ? 1389 options.host_key_alias : options.host_arg); 1390 cinfo->conn_hash_hex = ssh_connection_hash(cinfo->thishost, host, 1391 cinfo->portstr, options.user); 1392 cinfo->host_arg = xstrdup(options.host_arg); 1393 cinfo->remhost = xstrdup(host); 1394 cinfo->remuser = xstrdup(options.user); 1395 cinfo->homedir = xstrdup(pw->pw_dir); 1396 cinfo->locuser = xstrdup(pw->pw_name); 1397 1398 /* Find canonic host name. */ 1399 if (strchr(host, '.') == NULL) { 1400 struct addrinfo hints; 1401 struct addrinfo *ai = NULL; 1402 int errgai; 1403 1404 memset(&hints, 0, sizeof(hints)); 1405 hints.ai_family = options.address_family; 1406 hints.ai_flags = AI_CANONNAME; 1407 hints.ai_socktype = SOCK_STREAM; 1408 errgai = getaddrinfo(host, NULL, &hints, &ai); 1409 if (errgai == 0) { 1410 if (ai->ai_canonname != NULL) { 1411 free(host); 1412 host = xstrdup(ai->ai_canonname); 1413 } 1414 freeaddrinfo(ai); 1415 } 1416 } 1417 1418 /* 1419 * Expand tokens in arguments. NB. LocalCommand is expanded later, 1420 * after port-forwarding is set up, so it may pick up any local 1421 * tunnel interface name allocated. 1422 */ 1423 if (options.remote_command != NULL) { 1424 debug3("expanding RemoteCommand: %s", options.remote_command); 1425 cp = options.remote_command; 1426 options.remote_command = default_client_percent_expand(cp, 1427 cinfo); 1428 debug3("expanded RemoteCommand: %s", options.remote_command); 1429 free(cp); 1430 if ((r = sshbuf_put(command, options.remote_command, 1431 strlen(options.remote_command))) != 0) 1432 fatal_fr(r, "buffer error"); 1433 } 1434 1435 if (options.control_path != NULL) { 1436 cp = tilde_expand_filename(options.control_path, getuid()); 1437 free(options.control_path); 1438 options.control_path = default_client_percent_dollar_expand(cp, 1439 cinfo); 1440 free(cp); 1441 } 1442 1443 if (options.identity_agent != NULL) { 1444 p = tilde_expand_filename(options.identity_agent, getuid()); 1445 cp = default_client_percent_dollar_expand(p, cinfo); 1446 free(p); 1447 free(options.identity_agent); 1448 options.identity_agent = cp; 1449 } 1450 1451 if (options.revoked_host_keys != NULL) { 1452 p = tilde_expand_filename(options.revoked_host_keys, getuid()); 1453 cp = default_client_percent_dollar_expand(p, cinfo); 1454 free(p); 1455 free(options.revoked_host_keys); 1456 options.revoked_host_keys = cp; 1457 } 1458 1459 if (options.forward_agent_sock_path != NULL) { 1460 p = tilde_expand_filename(options.forward_agent_sock_path, 1461 getuid()); 1462 cp = default_client_percent_dollar_expand(p, cinfo); 1463 free(p); 1464 free(options.forward_agent_sock_path); 1465 options.forward_agent_sock_path = cp; 1466 if (stat(options.forward_agent_sock_path, &st) != 0) { 1467 error("Cannot forward agent socket path \"%s\": %s", 1468 options.forward_agent_sock_path, strerror(errno)); 1469 if (options.exit_on_forward_failure) 1470 cleanup_exit(255); 1471 } 1472 } 1473 1474 if (options.num_system_hostfiles > 0 && 1475 strcasecmp(options.system_hostfiles[0], "none") == 0) { 1476 if (options.num_system_hostfiles > 1) 1477 fatal("Invalid GlobalKnownHostsFiles: \"none\" " 1478 "appears with other entries"); 1479 free(options.system_hostfiles[0]); 1480 options.system_hostfiles[0] = NULL; 1481 options.num_system_hostfiles = 0; 1482 } 1483 1484 if (options.num_user_hostfiles > 0 && 1485 strcasecmp(options.user_hostfiles[0], "none") == 0) { 1486 if (options.num_user_hostfiles > 1) 1487 fatal("Invalid UserKnownHostsFiles: \"none\" " 1488 "appears with other entries"); 1489 free(options.user_hostfiles[0]); 1490 options.user_hostfiles[0] = NULL; 1491 options.num_user_hostfiles = 0; 1492 } 1493 for (j = 0; j < options.num_user_hostfiles; j++) { 1494 if (options.user_hostfiles[j] == NULL) 1495 continue; 1496 cp = tilde_expand_filename(options.user_hostfiles[j], getuid()); 1497 p = default_client_percent_dollar_expand(cp, cinfo); 1498 if (strcmp(options.user_hostfiles[j], p) != 0) 1499 debug3("expanded UserKnownHostsFile '%s' -> " 1500 "'%s'", options.user_hostfiles[j], p); 1501 free(options.user_hostfiles[j]); 1502 free(cp); 1503 options.user_hostfiles[j] = p; 1504 } 1505 1506 for (i = 0; i < options.num_local_forwards; i++) { 1507 if (options.local_forwards[i].listen_path != NULL) { 1508 cp = options.local_forwards[i].listen_path; 1509 p = options.local_forwards[i].listen_path = 1510 default_client_percent_expand(cp, cinfo); 1511 if (strcmp(cp, p) != 0) 1512 debug3("expanded LocalForward listen path " 1513 "'%s' -> '%s'", cp, p); 1514 free(cp); 1515 } 1516 if (options.local_forwards[i].connect_path != NULL) { 1517 cp = options.local_forwards[i].connect_path; 1518 p = options.local_forwards[i].connect_path = 1519 default_client_percent_expand(cp, cinfo); 1520 if (strcmp(cp, p) != 0) 1521 debug3("expanded LocalForward connect path " 1522 "'%s' -> '%s'", cp, p); 1523 free(cp); 1524 } 1525 } 1526 1527 for (i = 0; i < options.num_remote_forwards; i++) { 1528 if (options.remote_forwards[i].listen_path != NULL) { 1529 cp = options.remote_forwards[i].listen_path; 1530 p = options.remote_forwards[i].listen_path = 1531 default_client_percent_expand(cp, cinfo); 1532 if (strcmp(cp, p) != 0) 1533 debug3("expanded RemoteForward listen path " 1534 "'%s' -> '%s'", cp, p); 1535 free(cp); 1536 } 1537 if (options.remote_forwards[i].connect_path != NULL) { 1538 cp = options.remote_forwards[i].connect_path; 1539 p = options.remote_forwards[i].connect_path = 1540 default_client_percent_expand(cp, cinfo); 1541 if (strcmp(cp, p) != 0) 1542 debug3("expanded RemoteForward connect path " 1543 "'%s' -> '%s'", cp, p); 1544 free(cp); 1545 } 1546 } 1547 1548 if (config_test) { 1549 dump_client_config(&options, host); 1550 exit(0); 1551 } 1552 1553 /* Expand SecurityKeyProvider if it refers to an environment variable */ 1554 if (options.sk_provider != NULL && *options.sk_provider == '$' && 1555 strlen(options.sk_provider) > 1) { 1556 if ((cp = getenv(options.sk_provider + 1)) == NULL) { 1557 debug("Authenticator provider %s did not resolve; " 1558 "disabling", options.sk_provider); 1559 free(options.sk_provider); 1560 options.sk_provider = NULL; 1561 } else { 1562 debug2("resolved SecurityKeyProvider %s => %s", 1563 options.sk_provider, cp); 1564 free(options.sk_provider); 1565 options.sk_provider = xstrdup(cp); 1566 } 1567 } 1568 1569 if (muxclient_command != 0 && options.control_path == NULL) 1570 fatal("No ControlPath specified for \"-O\" command"); 1571 if (options.control_path != NULL) { 1572 int sock; 1573 if ((sock = muxclient(options.control_path)) >= 0) { 1574 ssh_packet_set_connection(ssh, sock, sock); 1575 ssh_packet_set_mux(ssh); 1576 goto skip_connect; 1577 } 1578 } 1579 1580 /* 1581 * If hostname canonicalisation was not enabled, then we may not 1582 * have yet resolved the hostname. Do so now. 1583 */ 1584 if (addrs == NULL && options.proxy_command == NULL) { 1585 debug2("resolving \"%s\" port %d", host, options.port); 1586 if ((addrs = resolve_host(host, options.port, 1, 1587 cname, sizeof(cname))) == NULL) 1588 cleanup_exit(255); /* resolve_host logs the error */ 1589 } 1590 1591 if (options.connection_timeout >= INT_MAX/1000) 1592 timeout_ms = INT_MAX; 1593 else 1594 timeout_ms = options.connection_timeout * 1000; 1595 1596 /* Open a connection to the remote host. */ 1597 if (ssh_connect(ssh, host, options.host_arg, addrs, &hostaddr, 1598 options.port, options.connection_attempts, 1599 &timeout_ms, options.tcp_keep_alive) != 0) 1600 exit(255); 1601 1602 if (addrs != NULL) 1603 freeaddrinfo(addrs); 1604 1605 ssh_packet_set_timeout(ssh, options.server_alive_interval, 1606 options.server_alive_count_max); 1607 1608 if (timeout_ms > 0) 1609 debug3("timeout: %d ms remain after connect", timeout_ms); 1610 1611 /* 1612 * If we successfully made the connection and we have hostbased auth 1613 * enabled, load the public keys so we can later use the ssh-keysign 1614 * helper to sign challenges. 1615 */ 1616 sensitive_data.nkeys = 0; 1617 sensitive_data.keys = NULL; 1618 if (options.hostbased_authentication) { 1619 int loaded = 0; 1620 1621 sensitive_data.nkeys = 10; 1622 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 1623 sizeof(*sensitive_data.keys)); 1624 1625 /* XXX check errors? */ 1626 #define L_PUBKEY(p,o) do { \ 1627 if ((o) >= sensitive_data.nkeys) \ 1628 fatal_f("pubkey out of array bounds"); \ 1629 check_load(sshkey_load_public(p, &(sensitive_data.keys[o]), NULL), \ 1630 &(sensitive_data.keys[o]), p, "pubkey"); \ 1631 if (sensitive_data.keys[o] != NULL) { \ 1632 debug2("hostbased key %d: %s key from \"%s\"", o, \ 1633 sshkey_ssh_name(sensitive_data.keys[o]), p); \ 1634 loaded++; \ 1635 } \ 1636 } while (0) 1637 #define L_CERT(p,o) do { \ 1638 if ((o) >= sensitive_data.nkeys) \ 1639 fatal_f("cert out of array bounds"); \ 1640 check_load(sshkey_load_cert(p, &(sensitive_data.keys[o])), \ 1641 &(sensitive_data.keys[o]), p, "cert"); \ 1642 if (sensitive_data.keys[o] != NULL) { \ 1643 debug2("hostbased key %d: %s cert from \"%s\"", o, \ 1644 sshkey_ssh_name(sensitive_data.keys[o]), p); \ 1645 loaded++; \ 1646 } \ 1647 } while (0) 1648 1649 if (options.hostbased_authentication == 1) { 1650 L_CERT(_PATH_HOST_ECDSA_KEY_FILE, 0); 1651 L_CERT(_PATH_HOST_ED25519_KEY_FILE, 1); 1652 L_CERT(_PATH_HOST_RSA_KEY_FILE, 2); 1653 L_CERT(_PATH_HOST_DSA_KEY_FILE, 3); 1654 L_PUBKEY(_PATH_HOST_ECDSA_KEY_FILE, 4); 1655 L_PUBKEY(_PATH_HOST_ED25519_KEY_FILE, 5); 1656 L_PUBKEY(_PATH_HOST_RSA_KEY_FILE, 6); 1657 L_PUBKEY(_PATH_HOST_DSA_KEY_FILE, 7); 1658 L_CERT(_PATH_HOST_XMSS_KEY_FILE, 8); 1659 L_PUBKEY(_PATH_HOST_XMSS_KEY_FILE, 9); 1660 if (loaded == 0) 1661 debug("HostbasedAuthentication enabled but no " 1662 "local public host keys could be loaded."); 1663 } 1664 } 1665 1666 /* load options.identity_files */ 1667 load_public_identity_files(cinfo); 1668 1669 /* optionally set the SSH_AUTHSOCKET_ENV_NAME variable */ 1670 if (options.identity_agent && 1671 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) { 1672 if (strcmp(options.identity_agent, "none") == 0) { 1673 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1674 } else { 1675 cp = options.identity_agent; 1676 /* legacy (limited) format */ 1677 if (cp[0] == '$' && cp[1] != '{') { 1678 if (!valid_env_name(cp + 1)) { 1679 fatal("Invalid IdentityAgent " 1680 "environment variable name %s", cp); 1681 } 1682 if ((p = getenv(cp + 1)) == NULL) 1683 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1684 else 1685 setenv(SSH_AUTHSOCKET_ENV_NAME, p, 1); 1686 } else { 1687 /* identity_agent specifies a path directly */ 1688 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1); 1689 } 1690 } 1691 } 1692 1693 if (options.forward_agent && options.forward_agent_sock_path != NULL) { 1694 cp = options.forward_agent_sock_path; 1695 if (cp[0] == '$') { 1696 if (!valid_env_name(cp + 1)) { 1697 fatal("Invalid ForwardAgent environment variable name %s", cp); 1698 } 1699 if ((p = getenv(cp + 1)) != NULL) 1700 forward_agent_sock_path = xstrdup(p); 1701 else 1702 options.forward_agent = 0; 1703 free(cp); 1704 } else { 1705 forward_agent_sock_path = cp; 1706 } 1707 } 1708 1709 /* Expand ~ in known host file names. */ 1710 tilde_expand_paths(options.system_hostfiles, 1711 options.num_system_hostfiles); 1712 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 1713 1714 ssh_signal(SIGCHLD, main_sigchld_handler); 1715 1716 /* Log into the remote system. Never returns if the login fails. */ 1717 ssh_login(ssh, &sensitive_data, host, (struct sockaddr *)&hostaddr, 1718 options.port, pw, timeout_ms, cinfo); 1719 1720 /* We no longer need the private host keys. Clear them now. */ 1721 if (sensitive_data.nkeys != 0) { 1722 for (i = 0; i < sensitive_data.nkeys; i++) { 1723 if (sensitive_data.keys[i] != NULL) { 1724 /* Destroys contents safely */ 1725 debug3("clear hostkey %d", i); 1726 sshkey_free(sensitive_data.keys[i]); 1727 sensitive_data.keys[i] = NULL; 1728 } 1729 } 1730 free(sensitive_data.keys); 1731 } 1732 for (i = 0; i < options.num_identity_files; i++) { 1733 free(options.identity_files[i]); 1734 options.identity_files[i] = NULL; 1735 if (options.identity_keys[i]) { 1736 sshkey_free(options.identity_keys[i]); 1737 options.identity_keys[i] = NULL; 1738 } 1739 } 1740 for (i = 0; i < options.num_certificate_files; i++) { 1741 free(options.certificate_files[i]); 1742 options.certificate_files[i] = NULL; 1743 } 1744 1745 #ifdef ENABLE_PKCS11 1746 (void)pkcs11_del_provider(options.pkcs11_provider); 1747 #endif 1748 1749 skip_connect: 1750 exit_status = ssh_session2(ssh, cinfo); 1751 ssh_conn_info_free(cinfo); 1752 ssh_packet_close(ssh); 1753 1754 if (options.control_path != NULL && muxserver_sock != -1) 1755 unlink(options.control_path); 1756 1757 /* Kill ProxyCommand if it is running. */ 1758 ssh_kill_proxy_command(); 1759 1760 return exit_status; 1761 } 1762 1763 static void 1764 control_persist_detach(void) 1765 { 1766 pid_t pid; 1767 1768 debug_f("backgrounding master process"); 1769 1770 /* 1771 * master (current process) into the background, and make the 1772 * foreground process a client of the backgrounded master. 1773 */ 1774 switch ((pid = fork())) { 1775 case -1: 1776 fatal_f("fork: %s", strerror(errno)); 1777 case 0: 1778 /* Child: master process continues mainloop */ 1779 break; 1780 default: 1781 /* 1782 * Parent: set up mux client to connect to backgrounded 1783 * master. 1784 */ 1785 debug2_f("background process is %ld", (long)pid); 1786 options.stdin_null = ostdin_null_flag; 1787 options.request_tty = orequest_tty; 1788 tty_flag = otty_flag; 1789 options.fork_after_authentication = ofork_after_authentication; 1790 options.session_type = osession_type; 1791 close(muxserver_sock); 1792 muxserver_sock = -1; 1793 options.control_master = SSHCTL_MASTER_NO; 1794 (void)muxclient(options.control_path); 1795 /* muxclient() doesn't return on success. */ 1796 fatal("Failed to connect to new control master"); 1797 } 1798 if (stdfd_devnull(1, 1, !(log_is_on_stderr() && debug_flag)) == -1) 1799 error_f("stdfd_devnull failed"); 1800 daemon(1, 1); 1801 setproctitle("%s [mux]", options.control_path); 1802 } 1803 1804 /* Do fork() after authentication. Used by "ssh -f" */ 1805 static void 1806 fork_postauth(void) 1807 { 1808 if (need_controlpersist_detach) 1809 control_persist_detach(); 1810 debug("forking to background"); 1811 options.fork_after_authentication = 0; 1812 if (daemon(1, 1) == -1) 1813 fatal("daemon() failed: %.200s", strerror(errno)); 1814 if (stdfd_devnull(1, 1, !(log_is_on_stderr() && debug_flag)) == -1) 1815 error_f("stdfd_devnull failed"); 1816 } 1817 1818 static void 1819 forwarding_success(void) 1820 { 1821 if (forward_confirms_pending == -1) 1822 return; 1823 if (--forward_confirms_pending == 0) { 1824 debug_f("all expected forwarding replies received"); 1825 if (options.fork_after_authentication) 1826 fork_postauth(); 1827 } else { 1828 debug2_f("%d expected forwarding replies remaining", 1829 forward_confirms_pending); 1830 } 1831 } 1832 1833 /* Callback for remote forward global requests */ 1834 static void 1835 ssh_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt) 1836 { 1837 struct Forward *rfwd = (struct Forward *)ctxt; 1838 u_int port; 1839 int r; 1840 1841 /* XXX verbose() on failure? */ 1842 debug("remote forward %s for: listen %s%s%d, connect %s:%d", 1843 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1844 rfwd->listen_path ? rfwd->listen_path : 1845 rfwd->listen_host ? rfwd->listen_host : "", 1846 (rfwd->listen_path || rfwd->listen_host) ? ":" : "", 1847 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path : 1848 rfwd->connect_host, rfwd->connect_port); 1849 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) { 1850 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1851 if ((r = sshpkt_get_u32(ssh, &port)) != 0) 1852 fatal_fr(r, "parse packet"); 1853 if (port > 65535) { 1854 error("Invalid allocated port %u for remote " 1855 "forward to %s:%d", port, 1856 rfwd->connect_host, rfwd->connect_port); 1857 /* Ensure failure processing runs below */ 1858 type = SSH2_MSG_REQUEST_FAILURE; 1859 channel_update_permission(ssh, 1860 rfwd->handle, -1); 1861 } else { 1862 rfwd->allocated_port = (int)port; 1863 logit("Allocated port %u for remote " 1864 "forward to %s:%d", 1865 rfwd->allocated_port, rfwd->connect_path ? 1866 rfwd->connect_path : rfwd->connect_host, 1867 rfwd->connect_port); 1868 channel_update_permission(ssh, 1869 rfwd->handle, rfwd->allocated_port); 1870 } 1871 } else { 1872 channel_update_permission(ssh, rfwd->handle, -1); 1873 } 1874 } 1875 1876 if (type == SSH2_MSG_REQUEST_FAILURE) { 1877 if (options.exit_on_forward_failure) { 1878 if (rfwd->listen_path != NULL) 1879 fatal("Error: remote port forwarding failed " 1880 "for listen path %s", rfwd->listen_path); 1881 else 1882 fatal("Error: remote port forwarding failed " 1883 "for listen port %d", rfwd->listen_port); 1884 } else { 1885 if (rfwd->listen_path != NULL) 1886 logit("Warning: remote port forwarding failed " 1887 "for listen path %s", rfwd->listen_path); 1888 else 1889 logit("Warning: remote port forwarding failed " 1890 "for listen port %d", rfwd->listen_port); 1891 } 1892 } 1893 forwarding_success(); 1894 } 1895 1896 static void 1897 client_cleanup_stdio_fwd(struct ssh *ssh, int id, int force, void *arg) 1898 { 1899 debug("stdio forwarding: done"); 1900 cleanup_exit(0); 1901 } 1902 1903 static void 1904 ssh_stdio_confirm(struct ssh *ssh, int id, int success, void *arg) 1905 { 1906 if (!success) 1907 fatal("stdio forwarding failed"); 1908 } 1909 1910 static void 1911 ssh_tun_confirm(struct ssh *ssh, int id, int success, void *arg) 1912 { 1913 if (!success) { 1914 error("Tunnel forwarding failed"); 1915 if (options.exit_on_forward_failure) 1916 cleanup_exit(255); 1917 } 1918 1919 debug_f("tunnel forward established, id=%d", id); 1920 forwarding_success(); 1921 } 1922 1923 static void 1924 ssh_init_stdio_forwarding(struct ssh *ssh) 1925 { 1926 Channel *c; 1927 int in, out; 1928 1929 if (options.stdio_forward_host == NULL) 1930 return; 1931 1932 debug3_f("%s:%d", options.stdio_forward_host, 1933 options.stdio_forward_port); 1934 1935 if ((in = dup(STDIN_FILENO)) == -1 || 1936 (out = dup(STDOUT_FILENO)) == -1) 1937 fatal_f("dup() in/out failed"); 1938 if ((c = channel_connect_stdio_fwd(ssh, options.stdio_forward_host, 1939 options.stdio_forward_port, in, out, 1940 CHANNEL_NONBLOCK_STDIO)) == NULL) 1941 fatal_f("channel_connect_stdio_fwd failed"); 1942 channel_register_cleanup(ssh, c->self, client_cleanup_stdio_fwd, 0); 1943 channel_register_open_confirm(ssh, c->self, ssh_stdio_confirm, NULL); 1944 } 1945 1946 static void 1947 ssh_init_forward_permissions(struct ssh *ssh, const char *what, char **opens, 1948 u_int num_opens) 1949 { 1950 u_int i; 1951 int port; 1952 char *addr, *arg, *oarg; 1953 int where = FORWARD_LOCAL; 1954 1955 channel_clear_permission(ssh, FORWARD_ADM, where); 1956 if (num_opens == 0) 1957 return; /* permit any */ 1958 1959 /* handle keywords: "any" / "none" */ 1960 if (num_opens == 1 && strcmp(opens[0], "any") == 0) 1961 return; 1962 if (num_opens == 1 && strcmp(opens[0], "none") == 0) { 1963 channel_disable_admin(ssh, where); 1964 return; 1965 } 1966 /* Otherwise treat it as a list of permitted host:port */ 1967 for (i = 0; i < num_opens; i++) { 1968 oarg = arg = xstrdup(opens[i]); 1969 addr = hpdelim(&arg); 1970 if (addr == NULL) 1971 fatal_f("missing host in %s", what); 1972 addr = cleanhostname(addr); 1973 if (arg == NULL || ((port = permitopen_port(arg)) < 0)) 1974 fatal_f("bad port number in %s", what); 1975 /* Send it to channels layer */ 1976 channel_add_permission(ssh, FORWARD_ADM, 1977 where, addr, port); 1978 free(oarg); 1979 } 1980 } 1981 1982 static void 1983 ssh_init_forwarding(struct ssh *ssh, char **ifname) 1984 { 1985 int success = 0; 1986 int i; 1987 1988 ssh_init_forward_permissions(ssh, "permitremoteopen", 1989 options.permitted_remote_opens, 1990 options.num_permitted_remote_opens); 1991 1992 if (options.exit_on_forward_failure) 1993 forward_confirms_pending = 0; /* track pending requests */ 1994 /* Initiate local TCP/IP port forwardings. */ 1995 for (i = 0; i < options.num_local_forwards; i++) { 1996 debug("Local connections to %.200s:%d forwarded to remote " 1997 "address %.200s:%d", 1998 (options.local_forwards[i].listen_path != NULL) ? 1999 options.local_forwards[i].listen_path : 2000 (options.local_forwards[i].listen_host == NULL) ? 2001 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") : 2002 options.local_forwards[i].listen_host, 2003 options.local_forwards[i].listen_port, 2004 (options.local_forwards[i].connect_path != NULL) ? 2005 options.local_forwards[i].connect_path : 2006 options.local_forwards[i].connect_host, 2007 options.local_forwards[i].connect_port); 2008 success += channel_setup_local_fwd_listener(ssh, 2009 &options.local_forwards[i], &options.fwd_opts); 2010 } 2011 if (i > 0 && success != i && options.exit_on_forward_failure) 2012 fatal("Could not request local forwarding."); 2013 if (i > 0 && success == 0) 2014 error("Could not request local forwarding."); 2015 2016 /* Initiate remote TCP/IP port forwardings. */ 2017 for (i = 0; i < options.num_remote_forwards; i++) { 2018 debug("Remote connections from %.200s:%d forwarded to " 2019 "local address %.200s:%d", 2020 (options.remote_forwards[i].listen_path != NULL) ? 2021 options.remote_forwards[i].listen_path : 2022 (options.remote_forwards[i].listen_host == NULL) ? 2023 "LOCALHOST" : options.remote_forwards[i].listen_host, 2024 options.remote_forwards[i].listen_port, 2025 (options.remote_forwards[i].connect_path != NULL) ? 2026 options.remote_forwards[i].connect_path : 2027 options.remote_forwards[i].connect_host, 2028 options.remote_forwards[i].connect_port); 2029 if ((options.remote_forwards[i].handle = 2030 channel_request_remote_forwarding(ssh, 2031 &options.remote_forwards[i])) >= 0) { 2032 client_register_global_confirm( 2033 ssh_confirm_remote_forward, 2034 &options.remote_forwards[i]); 2035 forward_confirms_pending++; 2036 } else if (options.exit_on_forward_failure) 2037 fatal("Could not request remote forwarding."); 2038 else 2039 logit("Warning: Could not request remote forwarding."); 2040 } 2041 2042 /* Initiate tunnel forwarding. */ 2043 if (options.tun_open != SSH_TUNMODE_NO) { 2044 if ((*ifname = client_request_tun_fwd(ssh, 2045 options.tun_open, options.tun_local, 2046 options.tun_remote, ssh_tun_confirm, NULL)) != NULL) 2047 forward_confirms_pending++; 2048 else if (options.exit_on_forward_failure) 2049 fatal("Could not request tunnel forwarding."); 2050 else 2051 error("Could not request tunnel forwarding."); 2052 } 2053 if (forward_confirms_pending > 0) { 2054 debug_f("expecting replies for %d forwards", 2055 forward_confirms_pending); 2056 } 2057 } 2058 2059 static void 2060 check_agent_present(void) 2061 { 2062 int r; 2063 2064 if (options.forward_agent) { 2065 /* Clear agent forwarding if we don't have an agent. */ 2066 if ((r = ssh_get_authentication_socket(NULL)) != 0) { 2067 options.forward_agent = 0; 2068 if (r != SSH_ERR_AGENT_NOT_PRESENT) 2069 debug_r(r, "ssh_get_authentication_socket"); 2070 } 2071 } 2072 } 2073 2074 static void 2075 ssh_session2_setup(struct ssh *ssh, int id, int success, void *arg) 2076 { 2077 extern char **environ; 2078 const char *display, *term; 2079 int r, interactive = tty_flag; 2080 char *proto = NULL, *data = NULL; 2081 2082 if (!success) 2083 return; /* No need for error message, channels code sends one */ 2084 2085 display = getenv("DISPLAY"); 2086 if (display == NULL && options.forward_x11) 2087 debug("X11 forwarding requested but DISPLAY not set"); 2088 if (options.forward_x11 && client_x11_get_proto(ssh, display, 2089 options.xauth_location, options.forward_x11_trusted, 2090 options.forward_x11_timeout, &proto, &data) == 0) { 2091 /* Request forwarding with authentication spoofing. */ 2092 debug("Requesting X11 forwarding with authentication " 2093 "spoofing."); 2094 x11_request_forwarding_with_spoofing(ssh, id, display, proto, 2095 data, 1); 2096 client_expect_confirm(ssh, id, "X11 forwarding", CONFIRM_WARN); 2097 /* XXX exit_on_forward_failure */ 2098 interactive = 1; 2099 } 2100 2101 check_agent_present(); 2102 if (options.forward_agent) { 2103 debug("Requesting authentication agent forwarding."); 2104 channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0); 2105 if ((r = sshpkt_send(ssh)) != 0) 2106 fatal_fr(r, "send packet"); 2107 } 2108 2109 /* Tell the packet module whether this is an interactive session. */ 2110 ssh_packet_set_interactive(ssh, interactive, 2111 options.ip_qos_interactive, options.ip_qos_bulk); 2112 2113 if ((term = lookup_env_in_list("TERM", options.setenv, 2114 options.num_setenv)) == NULL || *term == '\0') 2115 term = getenv("TERM"); 2116 client_session2_setup(ssh, id, tty_flag, 2117 options.session_type == SESSION_TYPE_SUBSYSTEM, term, 2118 NULL, fileno(stdin), command, environ); 2119 } 2120 2121 /* open new channel for a session */ 2122 static int 2123 ssh_session2_open(struct ssh *ssh) 2124 { 2125 Channel *c; 2126 int window, packetmax, in, out, err; 2127 2128 if (options.stdin_null) { 2129 in = open(_PATH_DEVNULL, O_RDONLY); 2130 } else { 2131 in = dup(STDIN_FILENO); 2132 } 2133 out = dup(STDOUT_FILENO); 2134 err = dup(STDERR_FILENO); 2135 2136 if (in == -1 || out == -1 || err == -1) 2137 fatal("dup() in/out/err failed"); 2138 2139 window = CHAN_SES_WINDOW_DEFAULT; 2140 packetmax = CHAN_SES_PACKET_DEFAULT; 2141 if (tty_flag) { 2142 window >>= 1; 2143 packetmax >>= 1; 2144 } 2145 c = channel_new(ssh, 2146 "session", SSH_CHANNEL_OPENING, in, out, err, 2147 window, packetmax, CHAN_EXTENDED_WRITE, 2148 "client-session", CHANNEL_NONBLOCK_STDIO); 2149 2150 debug3_f("channel_new: %d", c->self); 2151 2152 channel_send_open(ssh, c->self); 2153 if (options.session_type != SESSION_TYPE_NONE) 2154 channel_register_open_confirm(ssh, c->self, 2155 ssh_session2_setup, NULL); 2156 2157 return c->self; 2158 } 2159 2160 static int 2161 ssh_session2(struct ssh *ssh, const struct ssh_conn_info *cinfo) 2162 { 2163 int r, interactive, id = -1; 2164 char *cp, *tun_fwd_ifname = NULL; 2165 2166 /* XXX should be pre-session */ 2167 if (!options.control_persist) 2168 ssh_init_stdio_forwarding(ssh); 2169 2170 ssh_init_forwarding(ssh, &tun_fwd_ifname); 2171 2172 if (options.local_command != NULL) { 2173 debug3("expanding LocalCommand: %s", options.local_command); 2174 cp = options.local_command; 2175 options.local_command = percent_expand(cp, 2176 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS(cinfo), 2177 "T", tun_fwd_ifname == NULL ? "NONE" : tun_fwd_ifname, 2178 (char *)NULL); 2179 debug3("expanded LocalCommand: %s", options.local_command); 2180 free(cp); 2181 } 2182 2183 /* Start listening for multiplex clients */ 2184 if (!ssh_packet_get_mux(ssh)) 2185 muxserver_listen(ssh); 2186 2187 /* 2188 * If we are in control persist mode and have a working mux listen 2189 * socket, then prepare to background ourselves and have a foreground 2190 * client attach as a control client. 2191 * NB. we must save copies of the flags that we override for 2192 * the backgrounding, since we defer attachment of the client until 2193 * after the connection is fully established (in particular, 2194 * async rfwd replies have been received for ExitOnForwardFailure). 2195 */ 2196 if (options.control_persist && muxserver_sock != -1) { 2197 ostdin_null_flag = options.stdin_null; 2198 osession_type = options.session_type; 2199 orequest_tty = options.request_tty; 2200 otty_flag = tty_flag; 2201 ofork_after_authentication = options.fork_after_authentication; 2202 options.stdin_null = 1; 2203 options.session_type = SESSION_TYPE_NONE; 2204 tty_flag = 0; 2205 if ((osession_type != SESSION_TYPE_NONE || 2206 options.stdio_forward_host != NULL)) 2207 need_controlpersist_detach = 1; 2208 options.fork_after_authentication = 1; 2209 } 2210 /* 2211 * ControlPersist mux listen socket setup failed, attempt the 2212 * stdio forward setup that we skipped earlier. 2213 */ 2214 if (options.control_persist && muxserver_sock == -1) 2215 ssh_init_stdio_forwarding(ssh); 2216 2217 if (options.session_type != SESSION_TYPE_NONE) 2218 id = ssh_session2_open(ssh); 2219 else { 2220 interactive = options.control_master == SSHCTL_MASTER_NO; 2221 /* ControlPersist may have clobbered ControlMaster, so check */ 2222 if (need_controlpersist_detach) 2223 interactive = otty_flag != 0; 2224 ssh_packet_set_interactive(ssh, interactive, 2225 options.ip_qos_interactive, options.ip_qos_bulk); 2226 } 2227 2228 /* If we don't expect to open a new session, then disallow it */ 2229 if (options.control_master == SSHCTL_MASTER_NO && 2230 (ssh->compat & SSH_NEW_OPENSSH)) { 2231 debug("Requesting no-more-sessions@openssh.com"); 2232 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 2233 (r = sshpkt_put_cstring(ssh, 2234 "no-more-sessions@openssh.com")) != 0 || 2235 (r = sshpkt_put_u8(ssh, 0)) != 0 || 2236 (r = sshpkt_send(ssh)) != 0) 2237 fatal_fr(r, "send packet"); 2238 } 2239 2240 /* Execute a local command */ 2241 if (options.local_command != NULL && 2242 options.permit_local_command) 2243 ssh_local_cmd(options.local_command); 2244 2245 /* 2246 * stdout is now owned by the session channel; clobber it here 2247 * so future channel closes are propagated to the local fd. 2248 * NB. this can only happen after LocalCommand has completed, 2249 * as it may want to write to stdout. 2250 */ 2251 if (!need_controlpersist_detach && stdfd_devnull(0, 1, 0) == -1) 2252 error_f("stdfd_devnull failed"); 2253 2254 /* 2255 * If requested and we are not interested in replies to remote 2256 * forwarding requests, then let ssh continue in the background. 2257 */ 2258 if (options.fork_after_authentication) { 2259 if (options.exit_on_forward_failure && 2260 options.num_remote_forwards > 0) { 2261 debug("deferring postauth fork until remote forward " 2262 "confirmation received"); 2263 } else 2264 fork_postauth(); 2265 } 2266 2267 return client_loop(ssh, tty_flag, tty_flag ? 2268 options.escape_char : SSH_ESCAPECHAR_NONE, id); 2269 } 2270 2271 /* Loads all IdentityFile and CertificateFile keys */ 2272 static void 2273 load_public_identity_files(const struct ssh_conn_info *cinfo) 2274 { 2275 char *filename, *cp; 2276 struct sshkey *public; 2277 int i; 2278 u_int n_ids, n_certs; 2279 char *identity_files[SSH_MAX_IDENTITY_FILES]; 2280 struct sshkey *identity_keys[SSH_MAX_IDENTITY_FILES]; 2281 int identity_file_userprovided[SSH_MAX_IDENTITY_FILES]; 2282 char *certificate_files[SSH_MAX_CERTIFICATE_FILES]; 2283 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES]; 2284 int certificate_file_userprovided[SSH_MAX_CERTIFICATE_FILES]; 2285 #ifdef ENABLE_PKCS11 2286 struct sshkey **keys = NULL; 2287 char **comments = NULL; 2288 int nkeys; 2289 #endif /* PKCS11 */ 2290 2291 n_ids = n_certs = 0; 2292 memset(identity_files, 0, sizeof(identity_files)); 2293 memset(identity_keys, 0, sizeof(identity_keys)); 2294 memset(identity_file_userprovided, 0, 2295 sizeof(identity_file_userprovided)); 2296 memset(certificate_files, 0, sizeof(certificate_files)); 2297 memset(certificates, 0, sizeof(certificates)); 2298 memset(certificate_file_userprovided, 0, 2299 sizeof(certificate_file_userprovided)); 2300 2301 #ifdef ENABLE_PKCS11 2302 if (options.pkcs11_provider != NULL && 2303 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 2304 (pkcs11_init(!options.batch_mode) == 0) && 2305 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 2306 &keys, &comments)) > 0) { 2307 for (i = 0; i < nkeys; i++) { 2308 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 2309 sshkey_free(keys[i]); 2310 free(comments[i]); 2311 continue; 2312 } 2313 identity_keys[n_ids] = keys[i]; 2314 identity_files[n_ids] = comments[i]; /* transferred */ 2315 n_ids++; 2316 } 2317 free(keys); 2318 free(comments); 2319 } 2320 #endif /* ENABLE_PKCS11 */ 2321 for (i = 0; i < options.num_identity_files; i++) { 2322 if (n_ids >= SSH_MAX_IDENTITY_FILES || 2323 strcasecmp(options.identity_files[i], "none") == 0) { 2324 free(options.identity_files[i]); 2325 options.identity_files[i] = NULL; 2326 continue; 2327 } 2328 cp = tilde_expand_filename(options.identity_files[i], getuid()); 2329 filename = default_client_percent_dollar_expand(cp, cinfo); 2330 free(cp); 2331 check_load(sshkey_load_public(filename, &public, NULL), 2332 &public, filename, "pubkey"); 2333 debug("identity file %s type %d", filename, 2334 public ? public->type : -1); 2335 free(options.identity_files[i]); 2336 identity_files[n_ids] = filename; 2337 identity_keys[n_ids] = public; 2338 identity_file_userprovided[n_ids] = 2339 options.identity_file_userprovided[i]; 2340 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 2341 continue; 2342 2343 /* 2344 * If no certificates have been explicitly listed then try 2345 * to add the default certificate variant too. 2346 */ 2347 if (options.num_certificate_files != 0) 2348 continue; 2349 xasprintf(&cp, "%s-cert", filename); 2350 check_load(sshkey_load_public(cp, &public, NULL), 2351 &public, filename, "pubkey"); 2352 debug("identity file %s type %d", cp, 2353 public ? public->type : -1); 2354 if (public == NULL) { 2355 free(cp); 2356 continue; 2357 } 2358 if (!sshkey_is_cert(public)) { 2359 debug_f("key %s type %s is not a certificate", 2360 cp, sshkey_type(public)); 2361 sshkey_free(public); 2362 free(cp); 2363 continue; 2364 } 2365 /* NB. leave filename pointing to private key */ 2366 identity_files[n_ids] = xstrdup(filename); 2367 identity_keys[n_ids] = public; 2368 identity_file_userprovided[n_ids] = 2369 options.identity_file_userprovided[i]; 2370 n_ids++; 2371 } 2372 2373 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES) 2374 fatal_f("too many certificates"); 2375 for (i = 0; i < options.num_certificate_files; i++) { 2376 cp = tilde_expand_filename(options.certificate_files[i], 2377 getuid()); 2378 filename = default_client_percent_dollar_expand(cp, cinfo); 2379 free(cp); 2380 2381 check_load(sshkey_load_public(filename, &public, NULL), 2382 &public, filename, "certificate"); 2383 debug("certificate file %s type %d", filename, 2384 public ? public->type : -1); 2385 free(options.certificate_files[i]); 2386 options.certificate_files[i] = NULL; 2387 if (public == NULL) { 2388 free(filename); 2389 continue; 2390 } 2391 if (!sshkey_is_cert(public)) { 2392 debug_f("key %s type %s is not a certificate", 2393 filename, sshkey_type(public)); 2394 sshkey_free(public); 2395 free(filename); 2396 continue; 2397 } 2398 certificate_files[n_certs] = filename; 2399 certificates[n_certs] = public; 2400 certificate_file_userprovided[n_certs] = 2401 options.certificate_file_userprovided[i]; 2402 ++n_certs; 2403 } 2404 2405 options.num_identity_files = n_ids; 2406 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 2407 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 2408 memcpy(options.identity_file_userprovided, 2409 identity_file_userprovided, sizeof(identity_file_userprovided)); 2410 2411 options.num_certificate_files = n_certs; 2412 memcpy(options.certificate_files, 2413 certificate_files, sizeof(certificate_files)); 2414 memcpy(options.certificates, certificates, sizeof(certificates)); 2415 memcpy(options.certificate_file_userprovided, 2416 certificate_file_userprovided, 2417 sizeof(certificate_file_userprovided)); 2418 } 2419 2420 static void 2421 main_sigchld_handler(int sig) 2422 { 2423 int save_errno = errno; 2424 pid_t pid; 2425 int status; 2426 2427 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 2428 (pid == -1 && errno == EINTR)) 2429 ; 2430 errno = save_errno; 2431 } 2432