1 /* $OpenBSD: ssh.c,v 1.527 2020/04/10 00:52:07 dtucker Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * Ssh client program. This program can be used to log into a remote machine. 7 * The software supports strong authentication, encryption, and forwarding 8 * of X11, TCP/IP, and authentication connections. 9 * 10 * As far as I am concerned, the code I have written for this software 11 * can be used freely for any purpose. Any derived versions of this 12 * software must be clearly marked as such, and if the derived work is 13 * incompatible with the protocol description in the RFC file, it must be 14 * called by a name other than "ssh" or "Secure Shell". 15 * 16 * Copyright (c) 1999 Niels Provos. All rights reserved. 17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved. 18 * 19 * Modified to work with 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 <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 /* 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 /* 171 * A config can specify a path to forward, overriding SSH_AUTH_SOCK. If this is 172 * not NULL, forward the socket at this path instead. 173 */ 174 char *forward_agent_sock_path = NULL; 175 176 /* Various strings used to to percent_expand() arguments */ 177 static char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 178 static char uidstr[32], *host_arg, *conn_hash_hex; 179 180 /* socket address the host resolves to */ 181 struct sockaddr_storage hostaddr; 182 183 /* Private host keys. */ 184 Sensitive sensitive_data; 185 186 /* command to be executed */ 187 struct sshbuf *command; 188 189 /* Should we execute a command or invoke a subsystem? */ 190 int subsystem_flag = 0; 191 192 /* # of replies received for global requests */ 193 static int forward_confirms_pending = -1; 194 195 /* mux.c */ 196 extern int muxserver_sock; 197 extern u_int muxclient_command; 198 199 /* Prints a help message to the user. This function never returns. */ 200 201 static void 202 usage(void) 203 { 204 fprintf(stderr, 205 "usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]\n" 206 " [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]\n" 207 " [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]\n" 208 " [-i identity_file] [-J [user@]host[:port]] [-L address]\n" 209 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" 210 " [-Q query_option] [-R address] [-S ctl_path] [-W host:port]\n" 211 " [-w local_tun[:remote_tun]] destination [command]\n" 212 ); 213 exit(255); 214 } 215 216 static int ssh_session2(struct ssh *, struct passwd *); 217 static void load_public_identity_files(struct passwd *); 218 static void main_sigchld_handler(int); 219 220 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 221 static void 222 tilde_expand_paths(char **paths, u_int num_paths) 223 { 224 u_int i; 225 char *cp; 226 227 for (i = 0; i < num_paths; i++) { 228 cp = tilde_expand_filename(paths[i], getuid()); 229 free(paths[i]); 230 paths[i] = cp; 231 } 232 } 233 234 #define DEFAULT_CLIENT_PERCENT_EXPAND_ARGS \ 235 "C", conn_hash_hex, \ 236 "L", shorthost, \ 237 "i", uidstr, \ 238 "l", thishost, \ 239 "n", host_arg, \ 240 "p", portstr 241 242 /* 243 * Expands the set of percent_expand options used by the majority of keywords 244 * in the client that support percent expansion. 245 * Caller must free returned string. 246 */ 247 static char * 248 default_client_percent_expand(const char *str, const char *homedir, 249 const char *remhost, const char *remuser, const char *locuser) 250 { 251 return percent_expand(str, 252 /* values from statics above */ 253 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS, 254 /* values from arguments */ 255 "d", homedir, 256 "h", remhost, 257 "r", remuser, 258 "u", locuser, 259 (char *)NULL); 260 } 261 262 /* 263 * Attempt to resolve a host name / port to a set of addresses and 264 * optionally return any CNAMEs encountered along the way. 265 * Returns NULL on failure. 266 * NB. this function must operate with a options having undefined members. 267 */ 268 static struct addrinfo * 269 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen) 270 { 271 char strport[NI_MAXSERV]; 272 struct addrinfo hints, *res; 273 int gaierr; 274 LogLevel loglevel = SYSLOG_LEVEL_DEBUG1; 275 276 if (port <= 0) 277 port = default_ssh_port(); 278 if (cname != NULL) 279 *cname = '\0'; 280 281 snprintf(strport, sizeof strport, "%d", port); 282 memset(&hints, 0, sizeof(hints)); 283 hints.ai_family = options.address_family == -1 ? 284 AF_UNSPEC : options.address_family; 285 hints.ai_socktype = SOCK_STREAM; 286 if (cname != NULL) 287 hints.ai_flags = AI_CANONNAME; 288 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 289 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) 290 loglevel = SYSLOG_LEVEL_ERROR; 291 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", 292 __progname, name, ssh_gai_strerror(gaierr)); 293 return NULL; 294 } 295 if (cname != NULL && res->ai_canonname != NULL) { 296 if (strlcpy(cname, res->ai_canonname, clen) >= clen) { 297 error("%s: host \"%s\" cname \"%s\" too long (max %lu)", 298 __func__, name, res->ai_canonname, (u_long)clen); 299 if (clen > 0) 300 *cname = '\0'; 301 } 302 } 303 return res; 304 } 305 306 /* Returns non-zero if name can only be an address and not a hostname */ 307 static int 308 is_addr_fast(const char *name) 309 { 310 return (strchr(name, '%') != NULL || strchr(name, ':') != NULL || 311 strspn(name, "0123456789.") == strlen(name)); 312 } 313 314 /* Returns non-zero if name represents a valid, single address */ 315 static int 316 is_addr(const char *name) 317 { 318 char strport[NI_MAXSERV]; 319 struct addrinfo hints, *res; 320 321 if (is_addr_fast(name)) 322 return 1; 323 324 snprintf(strport, sizeof strport, "%u", default_ssh_port()); 325 memset(&hints, 0, sizeof(hints)); 326 hints.ai_family = options.address_family == -1 ? 327 AF_UNSPEC : options.address_family; 328 hints.ai_socktype = SOCK_STREAM; 329 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 330 if (getaddrinfo(name, strport, &hints, &res) != 0) 331 return 0; 332 if (res == NULL || res->ai_next != NULL) { 333 freeaddrinfo(res); 334 return 0; 335 } 336 freeaddrinfo(res); 337 return 1; 338 } 339 340 /* 341 * Attempt to resolve a numeric host address / port to a single address. 342 * Returns a canonical address string. 343 * Returns NULL on failure. 344 * NB. this function must operate with a options having undefined members. 345 */ 346 static struct addrinfo * 347 resolve_addr(const char *name, int port, char *caddr, size_t clen) 348 { 349 char addr[NI_MAXHOST], strport[NI_MAXSERV]; 350 struct addrinfo hints, *res; 351 int gaierr; 352 353 if (port <= 0) 354 port = default_ssh_port(); 355 snprintf(strport, sizeof strport, "%u", port); 356 memset(&hints, 0, sizeof(hints)); 357 hints.ai_family = options.address_family == -1 ? 358 AF_UNSPEC : options.address_family; 359 hints.ai_socktype = SOCK_STREAM; 360 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 361 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 362 debug2("%s: could not resolve name %.100s as address: %s", 363 __func__, name, ssh_gai_strerror(gaierr)); 364 return NULL; 365 } 366 if (res == NULL) { 367 debug("%s: getaddrinfo %.100s returned no addresses", 368 __func__, name); 369 return NULL; 370 } 371 if (res->ai_next != NULL) { 372 debug("%s: getaddrinfo %.100s returned multiple addresses", 373 __func__, name); 374 goto fail; 375 } 376 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen, 377 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) { 378 debug("%s: Could not format address for name %.100s: %s", 379 __func__, name, ssh_gai_strerror(gaierr)); 380 goto fail; 381 } 382 if (strlcpy(caddr, addr, clen) >= clen) { 383 error("%s: host \"%s\" addr \"%s\" too long (max %lu)", 384 __func__, name, addr, (u_long)clen); 385 if (clen > 0) 386 *caddr = '\0'; 387 fail: 388 freeaddrinfo(res); 389 return NULL; 390 } 391 return res; 392 } 393 394 /* 395 * Check whether the cname is a permitted replacement for the hostname 396 * and perform the replacement if it is. 397 * NB. this function must operate with a options having undefined members. 398 */ 399 static int 400 check_follow_cname(int direct, char **namep, const char *cname) 401 { 402 int i; 403 struct allowed_cname *rule; 404 405 if (*cname == '\0' || options.num_permitted_cnames == 0 || 406 strcmp(*namep, cname) == 0) 407 return 0; 408 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 409 return 0; 410 /* 411 * Don't attempt to canonicalize names that will be interpreted by 412 * a proxy or jump host unless the user specifically requests so. 413 */ 414 if (!direct && 415 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 416 return 0; 417 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname); 418 for (i = 0; i < options.num_permitted_cnames; i++) { 419 rule = options.permitted_cnames + i; 420 if (match_pattern_list(*namep, rule->source_list, 1) != 1 || 421 match_pattern_list(cname, rule->target_list, 1) != 1) 422 continue; 423 verbose("Canonicalized DNS aliased hostname " 424 "\"%s\" => \"%s\"", *namep, cname); 425 free(*namep); 426 *namep = xstrdup(cname); 427 return 1; 428 } 429 return 0; 430 } 431 432 /* 433 * Attempt to resolve the supplied hostname after applying the user's 434 * canonicalization rules. Returns the address list for the host or NULL 435 * if no name was found after canonicalization. 436 * NB. this function must operate with a options having undefined members. 437 */ 438 static struct addrinfo * 439 resolve_canonicalize(char **hostp, int port) 440 { 441 int i, direct, ndots; 442 char *cp, *fullhost, newname[NI_MAXHOST]; 443 struct addrinfo *addrs; 444 445 /* 446 * Attempt to canonicalise addresses, regardless of 447 * whether hostname canonicalisation was requested 448 */ 449 if ((addrs = resolve_addr(*hostp, port, 450 newname, sizeof(newname))) != NULL) { 451 debug2("%s: hostname %.100s is address", __func__, *hostp); 452 if (strcasecmp(*hostp, newname) != 0) { 453 debug2("%s: canonicalised address \"%s\" => \"%s\"", 454 __func__, *hostp, newname); 455 free(*hostp); 456 *hostp = xstrdup(newname); 457 } 458 return addrs; 459 } 460 461 /* 462 * If this looks like an address but didn't parse as one, it might 463 * be an address with an invalid interface scope. Skip further 464 * attempts at canonicalisation. 465 */ 466 if (is_addr_fast(*hostp)) { 467 debug("%s: hostname %.100s is an unrecognised address", 468 __func__, *hostp); 469 return NULL; 470 } 471 472 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 473 return NULL; 474 475 /* 476 * Don't attempt to canonicalize names that will be interpreted by 477 * a proxy unless the user specifically requests so. 478 */ 479 direct = option_clear_or_none(options.proxy_command) && 480 options.jump_host == NULL; 481 if (!direct && 482 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 483 return NULL; 484 485 /* If domain name is anchored, then resolve it now */ 486 if ((*hostp)[strlen(*hostp) - 1] == '.') { 487 debug3("%s: name is fully qualified", __func__); 488 fullhost = xstrdup(*hostp); 489 if ((addrs = resolve_host(fullhost, port, 0, 490 newname, sizeof(newname))) != NULL) 491 goto found; 492 free(fullhost); 493 goto notfound; 494 } 495 496 /* Don't apply canonicalization to sufficiently-qualified hostnames */ 497 ndots = 0; 498 for (cp = *hostp; *cp != '\0'; cp++) { 499 if (*cp == '.') 500 ndots++; 501 } 502 if (ndots > options.canonicalize_max_dots) { 503 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)", 504 __func__, *hostp, options.canonicalize_max_dots); 505 return NULL; 506 } 507 /* Attempt each supplied suffix */ 508 for (i = 0; i < options.num_canonical_domains; i++) { 509 xasprintf(&fullhost, "%s.%s.", *hostp, 510 options.canonical_domains[i]); 511 debug3("%s: attempting \"%s\" => \"%s\"", __func__, 512 *hostp, fullhost); 513 if ((addrs = resolve_host(fullhost, port, 0, 514 newname, sizeof(newname))) == NULL) { 515 free(fullhost); 516 continue; 517 } 518 found: 519 /* Remove trailing '.' */ 520 fullhost[strlen(fullhost) - 1] = '\0'; 521 /* Follow CNAME if requested */ 522 if (!check_follow_cname(direct, &fullhost, newname)) { 523 debug("Canonicalized hostname \"%s\" => \"%s\"", 524 *hostp, fullhost); 525 } 526 free(*hostp); 527 *hostp = fullhost; 528 return addrs; 529 } 530 notfound: 531 if (!options.canonicalize_fallback_local) 532 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); 533 debug2("%s: host %s not found in any suffix", __func__, *hostp); 534 return NULL; 535 } 536 537 /* 538 * Check the result of hostkey loading, ignoring some errors and 539 * fatal()ing for others. 540 */ 541 static void 542 check_load(int r, const char *path, const char *message) 543 { 544 switch (r) { 545 case 0: 546 break; 547 case SSH_ERR_INTERNAL_ERROR: 548 case SSH_ERR_ALLOC_FAIL: 549 fatal("load %s \"%s\": %s", message, path, ssh_err(r)); 550 case SSH_ERR_SYSTEM_ERROR: 551 /* Ignore missing files */ 552 if (errno == ENOENT) 553 break; 554 /* FALLTHROUGH */ 555 default: 556 error("load %s \"%s\": %s", message, path, ssh_err(r)); 557 break; 558 } 559 } 560 561 /* 562 * Read per-user configuration file. Ignore the system wide config 563 * file if the user specifies a config file on the command line. 564 */ 565 static void 566 process_config_files(const char *host_name, struct passwd *pw, int final_pass, 567 int *want_final_pass) 568 { 569 char buf[PATH_MAX]; 570 int r; 571 572 if (config != NULL) { 573 if (strcasecmp(config, "none") != 0 && 574 !read_config_file(config, pw, host, host_name, &options, 575 SSHCONF_USERCONF | (final_pass ? SSHCONF_FINAL : 0), 576 want_final_pass)) 577 fatal("Can't open user config file %.100s: " 578 "%.100s", config, strerror(errno)); 579 } else { 580 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 581 _PATH_SSH_USER_CONFFILE); 582 if (r > 0 && (size_t)r < sizeof(buf)) 583 (void)read_config_file(buf, pw, host, host_name, 584 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF | 585 (final_pass ? SSHCONF_FINAL : 0), want_final_pass); 586 587 /* Read systemwide configuration file after user config. */ 588 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, 589 host, host_name, &options, 590 final_pass ? SSHCONF_FINAL : 0, want_final_pass); 591 } 592 } 593 594 /* Rewrite the port number in an addrinfo list of addresses */ 595 static void 596 set_addrinfo_port(struct addrinfo *addrs, int port) 597 { 598 struct addrinfo *addr; 599 600 for (addr = addrs; addr != NULL; addr = addr->ai_next) { 601 switch (addr->ai_family) { 602 case AF_INET: 603 ((struct sockaddr_in *)addr->ai_addr)-> 604 sin_port = htons(port); 605 break; 606 case AF_INET6: 607 ((struct sockaddr_in6 *)addr->ai_addr)-> 608 sin6_port = htons(port); 609 break; 610 } 611 } 612 } 613 614 /* 615 * Main program for the ssh client. 616 */ 617 int 618 main(int ac, char **av) 619 { 620 struct ssh *ssh = NULL; 621 int i, r, opt, exit_status, use_syslog, direct, timeout_ms; 622 int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0; 623 char *p, *cp, *line, *argv0, buf[PATH_MAX], *logfile; 624 char cname[NI_MAXHOST]; 625 struct stat st; 626 struct passwd *pw; 627 extern int optind, optreset; 628 extern char *optarg; 629 struct Forward fwd; 630 struct addrinfo *addrs = NULL; 631 size_t n, len; 632 633 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 634 sanitise_stdfd(); 635 636 __progname = ssh_get_progname(av[0]); 637 638 #ifndef HAVE_SETPROCTITLE 639 /* Prepare for later setproctitle emulation */ 640 /* Save argv so it isn't clobbered by setproctitle() emulation */ 641 saved_av = xcalloc(ac + 1, sizeof(*saved_av)); 642 for (i = 0; i < ac; i++) 643 saved_av[i] = xstrdup(av[i]); 644 saved_av[i] = NULL; 645 compat_init_setproctitle(ac, av); 646 av = saved_av; 647 #endif 648 649 seed_rng(); 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 /* Get user data. */ 658 pw = getpwuid(getuid()); 659 if (!pw) { 660 logit("No user exists for uid %lu", (u_long)getuid()); 661 exit(255); 662 } 663 /* Take a copy of the returned structure. */ 664 pw = pwcopy(pw); 665 666 /* 667 * Set our umask to something reasonable, as some files are created 668 * with the default umask. This will make them world-readable but 669 * writable only by the owner, which is ok for all files for which we 670 * don't set the modes explicitly. 671 */ 672 umask(022); 673 674 msetlocale(); 675 676 /* 677 * Initialize option structure to indicate that no values have been 678 * set. 679 */ 680 initialize_options(&options); 681 682 /* 683 * Prepare main ssh transport/connection structures 684 */ 685 if ((ssh = ssh_alloc_session_state()) == NULL) 686 fatal("Couldn't allocate session state"); 687 channel_init_channels(ssh); 688 689 /* Parse command-line arguments. */ 690 host = NULL; 691 use_syslog = 0; 692 logfile = NULL; 693 argv0 = av[0]; 694 695 again: 696 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 697 "AB:CD:E:F:GI:J:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { 698 switch (opt) { 699 case '1': 700 fatal("SSH protocol v.1 is no longer supported"); 701 break; 702 case '2': 703 /* Ignored */ 704 break; 705 case '4': 706 options.address_family = AF_INET; 707 break; 708 case '6': 709 options.address_family = AF_INET6; 710 break; 711 case 'n': 712 stdin_null_flag = 1; 713 break; 714 case 'f': 715 fork_after_authentication_flag = 1; 716 stdin_null_flag = 1; 717 break; 718 case 'x': 719 options.forward_x11 = 0; 720 break; 721 case 'X': 722 options.forward_x11 = 1; 723 break; 724 case 'y': 725 use_syslog = 1; 726 break; 727 case 'E': 728 logfile = optarg; 729 break; 730 case 'G': 731 config_test = 1; 732 break; 733 case 'Y': 734 options.forward_x11 = 1; 735 options.forward_x11_trusted = 1; 736 break; 737 case 'g': 738 options.fwd_opts.gateway_ports = 1; 739 break; 740 case 'O': 741 if (options.stdio_forward_host != NULL) 742 fatal("Cannot specify multiplexing " 743 "command with -W"); 744 else if (muxclient_command != 0) 745 fatal("Multiplexing command already specified"); 746 if (strcmp(optarg, "check") == 0) 747 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 748 else if (strcmp(optarg, "forward") == 0) 749 muxclient_command = SSHMUX_COMMAND_FORWARD; 750 else if (strcmp(optarg, "exit") == 0) 751 muxclient_command = SSHMUX_COMMAND_TERMINATE; 752 else if (strcmp(optarg, "stop") == 0) 753 muxclient_command = SSHMUX_COMMAND_STOP; 754 else if (strcmp(optarg, "cancel") == 0) 755 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 756 else if (strcmp(optarg, "proxy") == 0) 757 muxclient_command = SSHMUX_COMMAND_PROXY; 758 else 759 fatal("Invalid multiplex command."); 760 break; 761 case 'P': /* deprecated */ 762 break; 763 case 'Q': 764 cp = NULL; 765 if (strcmp(optarg, "cipher") == 0 || 766 strcasecmp(optarg, "Ciphers") == 0) 767 cp = cipher_alg_list('\n', 0); 768 else if (strcmp(optarg, "cipher-auth") == 0) 769 cp = cipher_alg_list('\n', 1); 770 else if (strcmp(optarg, "mac") == 0 || 771 strcasecmp(optarg, "MACs") == 0) 772 cp = mac_alg_list('\n'); 773 else if (strcmp(optarg, "kex") == 0 || 774 strcasecmp(optarg, "KexAlgorithms") == 0) 775 cp = kex_alg_list('\n'); 776 else if (strcmp(optarg, "key") == 0) 777 cp = sshkey_alg_list(0, 0, 0, '\n'); 778 else if (strcmp(optarg, "key-cert") == 0) 779 cp = sshkey_alg_list(1, 0, 0, '\n'); 780 else if (strcmp(optarg, "key-plain") == 0) 781 cp = sshkey_alg_list(0, 1, 0, '\n'); 782 else if (strcmp(optarg, "key-sig") == 0 || 783 strcasecmp(optarg, "PubkeyAcceptedKeyTypes") == 0 || 784 strcasecmp(optarg, "HostKeyAlgorithms") == 0 || 785 strcasecmp(optarg, "HostbasedKeyTypes") == 0 || 786 strcasecmp(optarg, "HostbasedAcceptedKeyTypes") == 0) 787 cp = sshkey_alg_list(0, 0, 1, '\n'); 788 else if (strcmp(optarg, "sig") == 0) 789 cp = sshkey_alg_list(0, 1, 1, '\n'); 790 else if (strcmp(optarg, "protocol-version") == 0) 791 cp = xstrdup("2"); 792 else if (strcmp(optarg, "compression") == 0) { 793 cp = xstrdup(compression_alg_list(0)); 794 len = strlen(cp); 795 for (n = 0; n < len; n++) 796 if (cp[n] == ',') 797 cp[n] = '\n'; 798 } else if (strcmp(optarg, "help") == 0) { 799 cp = xstrdup( 800 "cipher\ncipher-auth\ncompression\nkex\n" 801 "key\nkey-cert\nkey-plain\nkey-sig\nmac\n" 802 "protocol-version\nsig"); 803 } 804 if (cp == NULL) 805 fatal("Unsupported query \"%s\"", optarg); 806 printf("%s\n", cp); 807 free(cp); 808 exit(0); 809 break; 810 case 'a': 811 options.forward_agent = 0; 812 break; 813 case 'A': 814 options.forward_agent = 1; 815 break; 816 case 'k': 817 options.gss_deleg_creds = 0; 818 break; 819 case 'K': 820 options.gss_authentication = 1; 821 options.gss_deleg_creds = 1; 822 break; 823 case 'i': 824 p = tilde_expand_filename(optarg, getuid()); 825 if (stat(p, &st) == -1) 826 fprintf(stderr, "Warning: Identity file %s " 827 "not accessible: %s.\n", p, 828 strerror(errno)); 829 else 830 add_identity_file(&options, NULL, p, 1); 831 free(p); 832 break; 833 case 'I': 834 #ifdef ENABLE_PKCS11 835 free(options.pkcs11_provider); 836 options.pkcs11_provider = xstrdup(optarg); 837 #else 838 fprintf(stderr, "no support for PKCS#11.\n"); 839 #endif 840 break; 841 case 'J': 842 if (options.jump_host != NULL) { 843 fatal("Only a single -J option is permitted " 844 "(use commas to separate multiple " 845 "jump hops)"); 846 } 847 if (options.proxy_command != NULL) 848 fatal("Cannot specify -J with ProxyCommand"); 849 if (parse_jump(optarg, &options, 1) == -1) 850 fatal("Invalid -J argument"); 851 options.proxy_command = xstrdup("none"); 852 break; 853 case 't': 854 if (options.request_tty == REQUEST_TTY_YES) 855 options.request_tty = REQUEST_TTY_FORCE; 856 else 857 options.request_tty = REQUEST_TTY_YES; 858 break; 859 case 'v': 860 if (debug_flag == 0) { 861 debug_flag = 1; 862 options.log_level = SYSLOG_LEVEL_DEBUG1; 863 } else { 864 if (options.log_level < SYSLOG_LEVEL_DEBUG3) { 865 debug_flag++; 866 options.log_level++; 867 } 868 } 869 break; 870 case 'V': 871 fprintf(stderr, "%s, %s\n", 872 SSH_RELEASE, 873 #ifdef WITH_OPENSSL 874 OpenSSL_version(OPENSSL_VERSION) 875 #else 876 "without OpenSSL" 877 #endif 878 ); 879 if (opt == 'V') 880 exit(0); 881 break; 882 case 'w': 883 if (options.tun_open == -1) 884 options.tun_open = SSH_TUNMODE_DEFAULT; 885 options.tun_local = a2tun(optarg, &options.tun_remote); 886 if (options.tun_local == SSH_TUNID_ERR) { 887 fprintf(stderr, 888 "Bad tun device '%s'\n", optarg); 889 exit(255); 890 } 891 break; 892 case 'W': 893 if (options.stdio_forward_host != NULL) 894 fatal("stdio forward already specified"); 895 if (muxclient_command != 0) 896 fatal("Cannot specify stdio forward with -O"); 897 if (parse_forward(&fwd, optarg, 1, 0)) { 898 options.stdio_forward_host = fwd.listen_host; 899 options.stdio_forward_port = fwd.listen_port; 900 free(fwd.connect_host); 901 } else { 902 fprintf(stderr, 903 "Bad stdio forwarding specification '%s'\n", 904 optarg); 905 exit(255); 906 } 907 options.request_tty = REQUEST_TTY_NO; 908 no_shell_flag = 1; 909 break; 910 case 'q': 911 options.log_level = SYSLOG_LEVEL_QUIET; 912 break; 913 case 'e': 914 if (optarg[0] == '^' && optarg[2] == 0 && 915 (u_char) optarg[1] >= 64 && 916 (u_char) optarg[1] < 128) 917 options.escape_char = (u_char) optarg[1] & 31; 918 else if (strlen(optarg) == 1) 919 options.escape_char = (u_char) optarg[0]; 920 else if (strcmp(optarg, "none") == 0) 921 options.escape_char = SSH_ESCAPECHAR_NONE; 922 else { 923 fprintf(stderr, "Bad escape character '%s'.\n", 924 optarg); 925 exit(255); 926 } 927 break; 928 case 'c': 929 if (!ciphers_valid(*optarg == '+' || *optarg == '^' ? 930 optarg + 1 : optarg)) { 931 fprintf(stderr, "Unknown cipher type '%s'\n", 932 optarg); 933 exit(255); 934 } 935 free(options.ciphers); 936 options.ciphers = xstrdup(optarg); 937 break; 938 case 'm': 939 if (mac_valid(optarg)) { 940 free(options.macs); 941 options.macs = xstrdup(optarg); 942 } else { 943 fprintf(stderr, "Unknown mac type '%s'\n", 944 optarg); 945 exit(255); 946 } 947 break; 948 case 'M': 949 if (options.control_master == SSHCTL_MASTER_YES) 950 options.control_master = SSHCTL_MASTER_ASK; 951 else 952 options.control_master = SSHCTL_MASTER_YES; 953 break; 954 case 'p': 955 if (options.port == -1) { 956 options.port = a2port(optarg); 957 if (options.port <= 0) { 958 fprintf(stderr, "Bad port '%s'\n", 959 optarg); 960 exit(255); 961 } 962 } 963 break; 964 case 'l': 965 if (options.user == NULL) 966 options.user = optarg; 967 break; 968 969 case 'L': 970 if (parse_forward(&fwd, optarg, 0, 0)) 971 add_local_forward(&options, &fwd); 972 else { 973 fprintf(stderr, 974 "Bad local forwarding specification '%s'\n", 975 optarg); 976 exit(255); 977 } 978 break; 979 980 case 'R': 981 if (parse_forward(&fwd, optarg, 0, 1) || 982 parse_forward(&fwd, optarg, 1, 1)) { 983 add_remote_forward(&options, &fwd); 984 } else { 985 fprintf(stderr, 986 "Bad remote forwarding specification " 987 "'%s'\n", optarg); 988 exit(255); 989 } 990 break; 991 992 case 'D': 993 if (parse_forward(&fwd, optarg, 1, 0)) { 994 add_local_forward(&options, &fwd); 995 } else { 996 fprintf(stderr, 997 "Bad dynamic forwarding specification " 998 "'%s'\n", optarg); 999 exit(255); 1000 } 1001 break; 1002 1003 case 'C': 1004 #ifdef WITH_ZLIB 1005 options.compression = 1; 1006 #else 1007 error("Compression not supported, disabling."); 1008 #endif 1009 break; 1010 case 'N': 1011 no_shell_flag = 1; 1012 options.request_tty = REQUEST_TTY_NO; 1013 break; 1014 case 'T': 1015 options.request_tty = REQUEST_TTY_NO; 1016 break; 1017 case 'o': 1018 line = xstrdup(optarg); 1019 if (process_config_line(&options, pw, 1020 host ? host : "", host ? host : "", line, 1021 "command-line", 0, NULL, SSHCONF_USERCONF) != 0) 1022 exit(255); 1023 free(line); 1024 break; 1025 case 's': 1026 subsystem_flag = 1; 1027 break; 1028 case 'S': 1029 free(options.control_path); 1030 options.control_path = xstrdup(optarg); 1031 break; 1032 case 'b': 1033 options.bind_address = optarg; 1034 break; 1035 case 'B': 1036 options.bind_interface = optarg; 1037 break; 1038 case 'F': 1039 config = optarg; 1040 break; 1041 default: 1042 usage(); 1043 } 1044 } 1045 1046 if (optind > 1 && strcmp(av[optind - 1], "--") == 0) 1047 opt_terminated = 1; 1048 1049 ac -= optind; 1050 av += optind; 1051 1052 if (ac > 0 && !host) { 1053 int tport; 1054 char *tuser; 1055 switch (parse_ssh_uri(*av, &tuser, &host, &tport)) { 1056 case -1: 1057 usage(); 1058 break; 1059 case 0: 1060 if (options.user == NULL) { 1061 options.user = tuser; 1062 tuser = NULL; 1063 } 1064 free(tuser); 1065 if (options.port == -1 && tport != -1) 1066 options.port = tport; 1067 break; 1068 default: 1069 p = xstrdup(*av); 1070 cp = strrchr(p, '@'); 1071 if (cp != NULL) { 1072 if (cp == p) 1073 usage(); 1074 if (options.user == NULL) { 1075 options.user = p; 1076 p = NULL; 1077 } 1078 *cp++ = '\0'; 1079 host = xstrdup(cp); 1080 free(p); 1081 } else 1082 host = p; 1083 break; 1084 } 1085 if (ac > 1 && !opt_terminated) { 1086 optind = optreset = 1; 1087 goto again; 1088 } 1089 ac--, av++; 1090 } 1091 1092 /* Check that we got a host name. */ 1093 if (!host) 1094 usage(); 1095 1096 host_arg = xstrdup(host); 1097 1098 /* Initialize the command to execute on remote host. */ 1099 if ((command = sshbuf_new()) == NULL) 1100 fatal("sshbuf_new failed"); 1101 1102 /* 1103 * Save the command to execute on the remote host in a buffer. There 1104 * is no limit on the length of the command, except by the maximum 1105 * packet size. Also sets the tty flag if there is no command. 1106 */ 1107 if (!ac) { 1108 /* No command specified - execute shell on a tty. */ 1109 if (subsystem_flag) { 1110 fprintf(stderr, 1111 "You must specify a subsystem to invoke.\n"); 1112 usage(); 1113 } 1114 } else { 1115 /* A command has been specified. Store it into the buffer. */ 1116 for (i = 0; i < ac; i++) { 1117 if ((r = sshbuf_putf(command, "%s%s", 1118 i ? " " : "", av[i])) != 0) 1119 fatal("%s: buffer error: %s", 1120 __func__, ssh_err(r)); 1121 } 1122 } 1123 1124 /* 1125 * Initialize "log" output. Since we are the client all output 1126 * goes to stderr unless otherwise specified by -y or -E. 1127 */ 1128 if (use_syslog && logfile != NULL) 1129 fatal("Can't specify both -y and -E"); 1130 if (logfile != NULL) 1131 log_redirect_stderr_to(logfile); 1132 log_init(argv0, 1133 options.log_level == SYSLOG_LEVEL_NOT_SET ? 1134 SYSLOG_LEVEL_INFO : options.log_level, 1135 options.log_facility == SYSLOG_FACILITY_NOT_SET ? 1136 SYSLOG_FACILITY_USER : options.log_facility, 1137 !use_syslog); 1138 1139 if (debug_flag) 1140 logit("%s, %s", SSH_RELEASE, 1141 #ifdef WITH_OPENSSL 1142 OpenSSL_version(OPENSSL_VERSION) 1143 #else 1144 "without OpenSSL" 1145 #endif 1146 ); 1147 1148 /* Parse the configuration files */ 1149 process_config_files(host_arg, pw, 0, &want_final_pass); 1150 if (want_final_pass) 1151 debug("configuration requests final Match pass"); 1152 1153 /* Hostname canonicalisation needs a few options filled. */ 1154 fill_default_options_for_canonicalization(&options); 1155 1156 /* If the user has replaced the hostname then take it into use now */ 1157 if (options.hostname != NULL) { 1158 /* NB. Please keep in sync with readconf.c:match_cfg_line() */ 1159 cp = percent_expand(options.hostname, 1160 "h", host, (char *)NULL); 1161 free(host); 1162 host = cp; 1163 free(options.hostname); 1164 options.hostname = xstrdup(host); 1165 } 1166 1167 /* Don't lowercase addresses, they will be explicitly canonicalised */ 1168 if ((was_addr = is_addr(host)) == 0) 1169 lowercase(host); 1170 1171 /* 1172 * Try to canonicalize if requested by configuration or the 1173 * hostname is an address. 1174 */ 1175 if (options.canonicalize_hostname != SSH_CANONICALISE_NO || was_addr) 1176 addrs = resolve_canonicalize(&host, options.port); 1177 1178 /* 1179 * If CanonicalizePermittedCNAMEs have been specified but 1180 * other canonicalization did not happen (by not being requested 1181 * or by failing with fallback) then the hostname may still be changed 1182 * as a result of CNAME following. 1183 * 1184 * Try to resolve the bare hostname name using the system resolver's 1185 * usual search rules and then apply the CNAME follow rules. 1186 * 1187 * Skip the lookup if a ProxyCommand is being used unless the user 1188 * has specifically requested canonicalisation for this case via 1189 * CanonicalizeHostname=always 1190 */ 1191 direct = option_clear_or_none(options.proxy_command) && 1192 options.jump_host == NULL; 1193 if (addrs == NULL && options.num_permitted_cnames != 0 && (direct || 1194 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { 1195 if ((addrs = resolve_host(host, options.port, 1196 direct, cname, sizeof(cname))) == NULL) { 1197 /* Don't fatal proxied host names not in the DNS */ 1198 if (direct) 1199 cleanup_exit(255); /* logged in resolve_host */ 1200 } else 1201 check_follow_cname(direct, &host, cname); 1202 } 1203 1204 /* 1205 * If canonicalisation is enabled then re-parse the configuration 1206 * files as new stanzas may match. 1207 */ 1208 if (options.canonicalize_hostname != 0 && !want_final_pass) { 1209 debug("hostname canonicalisation enabled, " 1210 "will re-parse configuration"); 1211 want_final_pass = 1; 1212 } 1213 1214 if (want_final_pass) { 1215 debug("re-parsing configuration"); 1216 free(options.hostname); 1217 options.hostname = xstrdup(host); 1218 process_config_files(host_arg, pw, 1, NULL); 1219 /* 1220 * Address resolution happens early with canonicalisation 1221 * enabled and the port number may have changed since, so 1222 * reset it in address list 1223 */ 1224 if (addrs != NULL && options.port > 0) 1225 set_addrinfo_port(addrs, options.port); 1226 } 1227 1228 /* Fill configuration defaults. */ 1229 fill_default_options(&options); 1230 1231 /* 1232 * If ProxyJump option specified, then construct a ProxyCommand now. 1233 */ 1234 if (options.jump_host != NULL) { 1235 char port_s[8]; 1236 const char *sshbin = argv0; 1237 int port = options.port, jumpport = options.jump_port; 1238 1239 if (port <= 0) 1240 port = default_ssh_port(); 1241 if (jumpport <= 0) 1242 jumpport = default_ssh_port(); 1243 if (strcmp(options.jump_host, host) == 0 && port == jumpport) 1244 fatal("jumphost loop via %s", options.jump_host); 1245 1246 /* 1247 * Try to use SSH indicated by argv[0], but fall back to 1248 * "ssh" if it appears unavailable. 1249 */ 1250 if (strchr(argv0, '/') != NULL && access(argv0, X_OK) != 0) 1251 sshbin = "ssh"; 1252 1253 /* Consistency check */ 1254 if (options.proxy_command != NULL) 1255 fatal("inconsistent options: ProxyCommand+ProxyJump"); 1256 /* Never use FD passing for ProxyJump */ 1257 options.proxy_use_fdpass = 0; 1258 snprintf(port_s, sizeof(port_s), "%d", options.jump_port); 1259 xasprintf(&options.proxy_command, 1260 "%s%s%s%s%s%s%s%s%s%s%.*s -W '[%%h]:%%p' %s", 1261 sshbin, 1262 /* Optional "-l user" argument if jump_user set */ 1263 options.jump_user == NULL ? "" : " -l ", 1264 options.jump_user == NULL ? "" : options.jump_user, 1265 /* Optional "-p port" argument if jump_port set */ 1266 options.jump_port <= 0 ? "" : " -p ", 1267 options.jump_port <= 0 ? "" : port_s, 1268 /* Optional additional jump hosts ",..." */ 1269 options.jump_extra == NULL ? "" : " -J ", 1270 options.jump_extra == NULL ? "" : options.jump_extra, 1271 /* Optional "-F" argumment if -F specified */ 1272 config == NULL ? "" : " -F ", 1273 config == NULL ? "" : config, 1274 /* Optional "-v" arguments if -v set */ 1275 debug_flag ? " -" : "", 1276 debug_flag, "vvv", 1277 /* Mandatory hostname */ 1278 options.jump_host); 1279 debug("Setting implicit ProxyCommand from ProxyJump: %s", 1280 options.proxy_command); 1281 } 1282 1283 if (options.port == 0) 1284 options.port = default_ssh_port(); 1285 channel_set_af(ssh, options.address_family); 1286 1287 /* Tidy and check options */ 1288 if (options.host_key_alias != NULL) 1289 lowercase(options.host_key_alias); 1290 if (options.proxy_command != NULL && 1291 strcmp(options.proxy_command, "-") == 0 && 1292 options.proxy_use_fdpass) 1293 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); 1294 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 1295 if (options.control_persist && options.control_path != NULL) { 1296 debug("UpdateHostKeys=ask is incompatible with " 1297 "ControlPersist; disabling"); 1298 options.update_hostkeys = 0; 1299 } else if (sshbuf_len(command) != 0 || 1300 options.remote_command != NULL || 1301 options.request_tty == REQUEST_TTY_NO) { 1302 debug("UpdateHostKeys=ask is incompatible with " 1303 "remote command execution; disabling"); 1304 options.update_hostkeys = 0; 1305 } else if (options.log_level < SYSLOG_LEVEL_INFO) { 1306 /* no point logging anything; user won't see it */ 1307 options.update_hostkeys = 0; 1308 } 1309 } 1310 if (options.connection_attempts <= 0) 1311 fatal("Invalid number of ConnectionAttempts"); 1312 1313 if (sshbuf_len(command) != 0 && options.remote_command != NULL) 1314 fatal("Cannot execute command-line and remote command."); 1315 1316 /* Cannot fork to background if no command. */ 1317 if (fork_after_authentication_flag && sshbuf_len(command) == 0 && 1318 options.remote_command == NULL && !no_shell_flag) 1319 fatal("Cannot fork into background without a command " 1320 "to execute."); 1321 1322 /* reinit */ 1323 log_init(argv0, options.log_level, options.log_facility, !use_syslog); 1324 1325 if (options.request_tty == REQUEST_TTY_YES || 1326 options.request_tty == REQUEST_TTY_FORCE) 1327 tty_flag = 1; 1328 1329 /* Allocate a tty by default if no command specified. */ 1330 if (sshbuf_len(command) == 0 && options.remote_command == NULL) 1331 tty_flag = options.request_tty != REQUEST_TTY_NO; 1332 1333 /* Force no tty */ 1334 if (options.request_tty == REQUEST_TTY_NO || 1335 (muxclient_command && muxclient_command != SSHMUX_COMMAND_PROXY)) 1336 tty_flag = 0; 1337 /* Do not allocate a tty if stdin is not a tty. */ 1338 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 1339 options.request_tty != REQUEST_TTY_FORCE) { 1340 if (tty_flag) 1341 logit("Pseudo-terminal will not be allocated because " 1342 "stdin is not a terminal."); 1343 tty_flag = 0; 1344 } 1345 1346 if (options.user == NULL) 1347 options.user = xstrdup(pw->pw_name); 1348 1349 /* Set up strings used to percent_expand() arguments */ 1350 if (gethostname(thishost, sizeof(thishost)) == -1) 1351 fatal("gethostname: %s", strerror(errno)); 1352 strlcpy(shorthost, thishost, sizeof(shorthost)); 1353 shorthost[strcspn(thishost, ".")] = '\0'; 1354 snprintf(portstr, sizeof(portstr), "%d", options.port); 1355 snprintf(uidstr, sizeof(uidstr), "%llu", 1356 (unsigned long long)pw->pw_uid); 1357 1358 conn_hash_hex = ssh_connection_hash(thishost, host, portstr, 1359 options.user); 1360 1361 /* 1362 * Expand tokens in arguments. NB. LocalCommand is expanded later, 1363 * after port-forwarding is set up, so it may pick up any local 1364 * tunnel interface name allocated. 1365 */ 1366 if (options.remote_command != NULL) { 1367 debug3("expanding RemoteCommand: %s", options.remote_command); 1368 cp = options.remote_command; 1369 options.remote_command = default_client_percent_expand(cp, 1370 pw->pw_dir, host, options.user, pw->pw_name); 1371 debug3("expanded RemoteCommand: %s", options.remote_command); 1372 free(cp); 1373 if ((r = sshbuf_put(command, options.remote_command, 1374 strlen(options.remote_command))) != 0) 1375 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1376 } 1377 1378 if (options.control_path != NULL) { 1379 cp = tilde_expand_filename(options.control_path, getuid()); 1380 free(options.control_path); 1381 options.control_path = default_client_percent_expand(cp, 1382 pw->pw_dir, host, options.user, pw->pw_name); 1383 free(cp); 1384 } 1385 1386 if (options.identity_agent != NULL) { 1387 p = tilde_expand_filename(options.identity_agent, getuid()); 1388 cp = default_client_percent_expand(p, 1389 pw->pw_dir, host, options.user, pw->pw_name); 1390 free(p); 1391 free(options.identity_agent); 1392 options.identity_agent = cp; 1393 } 1394 1395 if (options.forward_agent_sock_path != NULL) { 1396 p = tilde_expand_filename(options.forward_agent_sock_path, 1397 getuid()); 1398 cp = default_client_percent_expand(p, 1399 pw->pw_dir, host, options.user, pw->pw_name); 1400 free(p); 1401 free(options.forward_agent_sock_path); 1402 options.forward_agent_sock_path = cp; 1403 } 1404 1405 for (i = 0; i < options.num_local_forwards; i++) { 1406 if (options.local_forwards[i].listen_path != NULL) { 1407 cp = options.local_forwards[i].listen_path; 1408 p = options.local_forwards[i].listen_path = 1409 default_client_percent_expand(cp, 1410 pw->pw_dir, host, options.user, pw->pw_name); 1411 if (strcmp(cp, p) != 0) 1412 debug3("expanded LocalForward listen path " 1413 "'%s' -> '%s'", cp, p); 1414 free(cp); 1415 } 1416 if (options.local_forwards[i].connect_path != NULL) { 1417 cp = options.local_forwards[i].connect_path; 1418 p = options.local_forwards[i].connect_path = 1419 default_client_percent_expand(cp, 1420 pw->pw_dir, host, options.user, pw->pw_name); 1421 if (strcmp(cp, p) != 0) 1422 debug3("expanded LocalForward connect path " 1423 "'%s' -> '%s'", cp, p); 1424 free(cp); 1425 } 1426 } 1427 1428 for (i = 0; i < options.num_remote_forwards; i++) { 1429 if (options.remote_forwards[i].listen_path != NULL) { 1430 cp = options.remote_forwards[i].listen_path; 1431 p = options.remote_forwards[i].listen_path = 1432 default_client_percent_expand(cp, 1433 pw->pw_dir, host, options.user, pw->pw_name); 1434 if (strcmp(cp, p) != 0) 1435 debug3("expanded RemoteForward listen path " 1436 "'%s' -> '%s'", cp, p); 1437 free(cp); 1438 } 1439 if (options.remote_forwards[i].connect_path != NULL) { 1440 cp = options.remote_forwards[i].connect_path; 1441 p = options.remote_forwards[i].connect_path = 1442 default_client_percent_expand(cp, 1443 pw->pw_dir, host, options.user, pw->pw_name); 1444 if (strcmp(cp, p) != 0) 1445 debug3("expanded RemoteForward connect path " 1446 "'%s' -> '%s'", cp, p); 1447 free(cp); 1448 } 1449 } 1450 1451 if (config_test) { 1452 dump_client_config(&options, host); 1453 exit(0); 1454 } 1455 1456 /* Expand SecurityKeyProvider if it refers to an environment variable */ 1457 if (options.sk_provider != NULL && *options.sk_provider == '$' && 1458 strlen(options.sk_provider) > 1) { 1459 if ((cp = getenv(options.sk_provider + 1)) == NULL) { 1460 debug("Authenticator provider %s did not resolve; " 1461 "disabling", options.sk_provider); 1462 free(options.sk_provider); 1463 options.sk_provider = NULL; 1464 } else { 1465 debug2("resolved SecurityKeyProvider %s => %s", 1466 options.sk_provider, cp); 1467 free(options.sk_provider); 1468 options.sk_provider = xstrdup(cp); 1469 } 1470 } 1471 1472 if (muxclient_command != 0 && options.control_path == NULL) 1473 fatal("No ControlPath specified for \"-O\" command"); 1474 if (options.control_path != NULL) { 1475 int sock; 1476 if ((sock = muxclient(options.control_path)) >= 0) { 1477 ssh_packet_set_connection(ssh, sock, sock); 1478 ssh_packet_set_mux(ssh); 1479 goto skip_connect; 1480 } 1481 } 1482 1483 /* 1484 * If hostname canonicalisation was not enabled, then we may not 1485 * have yet resolved the hostname. Do so now. 1486 */ 1487 if (addrs == NULL && options.proxy_command == NULL) { 1488 debug2("resolving \"%s\" port %d", host, options.port); 1489 if ((addrs = resolve_host(host, options.port, 1, 1490 cname, sizeof(cname))) == NULL) 1491 cleanup_exit(255); /* resolve_host logs the error */ 1492 } 1493 1494 timeout_ms = options.connection_timeout * 1000; 1495 1496 /* Open a connection to the remote host. */ 1497 if (ssh_connect(ssh, host, host_arg, addrs, &hostaddr, options.port, 1498 options.address_family, options.connection_attempts, 1499 &timeout_ms, options.tcp_keep_alive) != 0) 1500 exit(255); 1501 1502 if (addrs != NULL) 1503 freeaddrinfo(addrs); 1504 1505 ssh_packet_set_timeout(ssh, options.server_alive_interval, 1506 options.server_alive_count_max); 1507 1508 if (timeout_ms > 0) 1509 debug3("timeout: %d ms remain after connect", timeout_ms); 1510 1511 /* 1512 * If we successfully made the connection and we have hostbased auth 1513 * enabled, load the public keys so we can later use the ssh-keysign 1514 * helper to sign challenges. 1515 */ 1516 sensitive_data.nkeys = 0; 1517 sensitive_data.keys = NULL; 1518 if (options.hostbased_authentication) { 1519 sensitive_data.nkeys = 10; 1520 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 1521 sizeof(struct sshkey)); 1522 1523 /* XXX check errors? */ 1524 #define L_PUBKEY(p,o) do { \ 1525 if ((o) >= sensitive_data.nkeys) \ 1526 fatal("%s pubkey out of array bounds", __func__); \ 1527 check_load(sshkey_load_public(p, &(sensitive_data.keys[o]), NULL), \ 1528 p, "pubkey"); \ 1529 } while (0) 1530 #define L_CERT(p,o) do { \ 1531 if ((o) >= sensitive_data.nkeys) \ 1532 fatal("%s cert out of array bounds", __func__); \ 1533 check_load(sshkey_load_cert(p, &(sensitive_data.keys[o])), p, "cert"); \ 1534 } while (0) 1535 1536 if (options.hostbased_authentication == 1) { 1537 L_CERT(_PATH_HOST_ECDSA_KEY_FILE, 0); 1538 L_CERT(_PATH_HOST_ED25519_KEY_FILE, 1); 1539 L_CERT(_PATH_HOST_RSA_KEY_FILE, 2); 1540 L_CERT(_PATH_HOST_DSA_KEY_FILE, 3); 1541 L_PUBKEY(_PATH_HOST_ECDSA_KEY_FILE, 4); 1542 L_PUBKEY(_PATH_HOST_ED25519_KEY_FILE, 5); 1543 L_PUBKEY(_PATH_HOST_RSA_KEY_FILE, 6); 1544 L_PUBKEY(_PATH_HOST_DSA_KEY_FILE, 7); 1545 L_CERT(_PATH_HOST_XMSS_KEY_FILE, 8); 1546 L_PUBKEY(_PATH_HOST_XMSS_KEY_FILE, 9); 1547 } 1548 } 1549 1550 /* Create ~/.ssh * directory if it doesn't already exist. */ 1551 if (config == NULL) { 1552 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 1553 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 1554 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) == -1) { 1555 #ifdef WITH_SELINUX 1556 ssh_selinux_setfscreatecon(buf); 1557 #endif 1558 if (mkdir(buf, 0700) < 0) 1559 error("Could not create directory '%.200s'.", 1560 buf); 1561 #ifdef WITH_SELINUX 1562 ssh_selinux_setfscreatecon(NULL); 1563 #endif 1564 } 1565 } 1566 /* load options.identity_files */ 1567 load_public_identity_files(pw); 1568 1569 /* optionally set the SSH_AUTHSOCKET_ENV_NAME variable */ 1570 if (options.identity_agent && 1571 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) { 1572 if (strcmp(options.identity_agent, "none") == 0) { 1573 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1574 } else { 1575 cp = options.identity_agent; 1576 if (cp[0] == '$') { 1577 if (!valid_env_name(cp + 1)) { 1578 fatal("Invalid IdentityAgent " 1579 "environment variable name %s", cp); 1580 } 1581 if ((p = getenv(cp + 1)) == NULL) 1582 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1583 else 1584 setenv(SSH_AUTHSOCKET_ENV_NAME, p, 1); 1585 } else { 1586 /* identity_agent specifies a path directly */ 1587 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1); 1588 } 1589 } 1590 } 1591 1592 if (options.forward_agent && options.forward_agent_sock_path != NULL) { 1593 cp = options.forward_agent_sock_path; 1594 if (cp[0] == '$') { 1595 if (!valid_env_name(cp + 1)) { 1596 fatal("Invalid ForwardAgent environment variable name %s", cp); 1597 } 1598 if ((p = getenv(cp + 1)) != NULL) 1599 forward_agent_sock_path = p; 1600 else 1601 options.forward_agent = 0; 1602 free(cp); 1603 } else { 1604 forward_agent_sock_path = cp; 1605 } 1606 } 1607 1608 /* Expand ~ in known host file names. */ 1609 tilde_expand_paths(options.system_hostfiles, 1610 options.num_system_hostfiles); 1611 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 1612 1613 ssh_signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 1614 ssh_signal(SIGCHLD, main_sigchld_handler); 1615 1616 /* Log into the remote system. Never returns if the login fails. */ 1617 ssh_login(ssh, &sensitive_data, host, (struct sockaddr *)&hostaddr, 1618 options.port, pw, timeout_ms); 1619 1620 if (ssh_packet_connection_is_on_socket(ssh)) { 1621 verbose("Authenticated to %s ([%s]:%d).", host, 1622 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); 1623 } else { 1624 verbose("Authenticated to %s (via proxy).", host); 1625 } 1626 1627 /* We no longer need the private host keys. Clear them now. */ 1628 if (sensitive_data.nkeys != 0) { 1629 for (i = 0; i < sensitive_data.nkeys; i++) { 1630 if (sensitive_data.keys[i] != NULL) { 1631 /* Destroys contents safely */ 1632 debug3("clear hostkey %d", i); 1633 sshkey_free(sensitive_data.keys[i]); 1634 sensitive_data.keys[i] = NULL; 1635 } 1636 } 1637 free(sensitive_data.keys); 1638 } 1639 for (i = 0; i < options.num_identity_files; i++) { 1640 free(options.identity_files[i]); 1641 options.identity_files[i] = NULL; 1642 if (options.identity_keys[i]) { 1643 sshkey_free(options.identity_keys[i]); 1644 options.identity_keys[i] = NULL; 1645 } 1646 } 1647 for (i = 0; i < options.num_certificate_files; i++) { 1648 free(options.certificate_files[i]); 1649 options.certificate_files[i] = NULL; 1650 } 1651 1652 skip_connect: 1653 exit_status = ssh_session2(ssh, pw); 1654 ssh_packet_close(ssh); 1655 1656 if (options.control_path != NULL && muxserver_sock != -1) 1657 unlink(options.control_path); 1658 1659 /* Kill ProxyCommand if it is running. */ 1660 ssh_kill_proxy_command(); 1661 1662 return exit_status; 1663 } 1664 1665 static void 1666 control_persist_detach(void) 1667 { 1668 pid_t pid; 1669 int devnull, keep_stderr; 1670 1671 debug("%s: backgrounding master process", __func__); 1672 1673 /* 1674 * master (current process) into the background, and make the 1675 * foreground process a client of the backgrounded master. 1676 */ 1677 switch ((pid = fork())) { 1678 case -1: 1679 fatal("%s: fork: %s", __func__, strerror(errno)); 1680 case 0: 1681 /* Child: master process continues mainloop */ 1682 break; 1683 default: 1684 /* Parent: set up mux slave to connect to backgrounded master */ 1685 debug2("%s: background process is %ld", __func__, (long)pid); 1686 stdin_null_flag = ostdin_null_flag; 1687 options.request_tty = orequest_tty; 1688 tty_flag = otty_flag; 1689 close(muxserver_sock); 1690 muxserver_sock = -1; 1691 options.control_master = SSHCTL_MASTER_NO; 1692 muxclient(options.control_path); 1693 /* muxclient() doesn't return on success. */ 1694 fatal("Failed to connect to new control master"); 1695 } 1696 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1697 error("%s: open(\"/dev/null\"): %s", __func__, 1698 strerror(errno)); 1699 } else { 1700 keep_stderr = log_is_on_stderr() && debug_flag; 1701 if (dup2(devnull, STDIN_FILENO) == -1 || 1702 dup2(devnull, STDOUT_FILENO) == -1 || 1703 (!keep_stderr && dup2(devnull, STDERR_FILENO) == -1)) 1704 error("%s: dup2: %s", __func__, strerror(errno)); 1705 if (devnull > STDERR_FILENO) 1706 close(devnull); 1707 } 1708 daemon(1, 1); 1709 setproctitle("%s [mux]", options.control_path); 1710 } 1711 1712 /* Do fork() after authentication. Used by "ssh -f" */ 1713 static void 1714 fork_postauth(void) 1715 { 1716 if (need_controlpersist_detach) 1717 control_persist_detach(); 1718 debug("forking to background"); 1719 fork_after_authentication_flag = 0; 1720 if (daemon(1, 1) == -1) 1721 fatal("daemon() failed: %.200s", strerror(errno)); 1722 } 1723 1724 static void 1725 forwarding_success(void) 1726 { 1727 if (forward_confirms_pending == -1) 1728 return; 1729 if (--forward_confirms_pending == 0) { 1730 debug("%s: all expected forwarding replies received", __func__); 1731 if (fork_after_authentication_flag) 1732 fork_postauth(); 1733 } else { 1734 debug2("%s: %d expected forwarding replies remaining", 1735 __func__, forward_confirms_pending); 1736 } 1737 } 1738 1739 /* Callback for remote forward global requests */ 1740 static void 1741 ssh_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt) 1742 { 1743 struct Forward *rfwd = (struct Forward *)ctxt; 1744 u_int port; 1745 int r; 1746 1747 /* XXX verbose() on failure? */ 1748 debug("remote forward %s for: listen %s%s%d, connect %s:%d", 1749 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1750 rfwd->listen_path ? rfwd->listen_path : 1751 rfwd->listen_host ? rfwd->listen_host : "", 1752 (rfwd->listen_path || rfwd->listen_host) ? ":" : "", 1753 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path : 1754 rfwd->connect_host, rfwd->connect_port); 1755 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) { 1756 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1757 if ((r = sshpkt_get_u32(ssh, &port)) != 0) 1758 fatal("%s: %s", __func__, ssh_err(r)); 1759 if (port > 65535) { 1760 error("Invalid allocated port %u for remote " 1761 "forward to %s:%d", port, 1762 rfwd->connect_host, rfwd->connect_port); 1763 /* Ensure failure processing runs below */ 1764 type = SSH2_MSG_REQUEST_FAILURE; 1765 channel_update_permission(ssh, 1766 rfwd->handle, -1); 1767 } else { 1768 rfwd->allocated_port = (int)port; 1769 logit("Allocated port %u for remote " 1770 "forward to %s:%d", 1771 rfwd->allocated_port, rfwd->connect_host, 1772 rfwd->connect_port); 1773 channel_update_permission(ssh, 1774 rfwd->handle, rfwd->allocated_port); 1775 } 1776 } else { 1777 channel_update_permission(ssh, rfwd->handle, -1); 1778 } 1779 } 1780 1781 if (type == SSH2_MSG_REQUEST_FAILURE) { 1782 if (options.exit_on_forward_failure) { 1783 if (rfwd->listen_path != NULL) 1784 fatal("Error: remote port forwarding failed " 1785 "for listen path %s", rfwd->listen_path); 1786 else 1787 fatal("Error: remote port forwarding failed " 1788 "for listen port %d", rfwd->listen_port); 1789 } else { 1790 if (rfwd->listen_path != NULL) 1791 logit("Warning: remote port forwarding failed " 1792 "for listen path %s", rfwd->listen_path); 1793 else 1794 logit("Warning: remote port forwarding failed " 1795 "for listen port %d", rfwd->listen_port); 1796 } 1797 } 1798 forwarding_success(); 1799 } 1800 1801 static void 1802 client_cleanup_stdio_fwd(struct ssh *ssh, int id, void *arg) 1803 { 1804 debug("stdio forwarding: done"); 1805 cleanup_exit(0); 1806 } 1807 1808 static void 1809 ssh_stdio_confirm(struct ssh *ssh, int id, int success, void *arg) 1810 { 1811 if (!success) 1812 fatal("stdio forwarding failed"); 1813 } 1814 1815 static void 1816 ssh_tun_confirm(struct ssh *ssh, int id, int success, void *arg) 1817 { 1818 if (!success) { 1819 error("Tunnel forwarding failed"); 1820 if (options.exit_on_forward_failure) 1821 cleanup_exit(255); 1822 } 1823 1824 debug("%s: tunnel forward established, id=%d", __func__, id); 1825 forwarding_success(); 1826 } 1827 1828 static void 1829 ssh_init_stdio_forwarding(struct ssh *ssh) 1830 { 1831 Channel *c; 1832 int in, out; 1833 1834 if (options.stdio_forward_host == NULL) 1835 return; 1836 1837 debug3("%s: %s:%d", __func__, options.stdio_forward_host, 1838 options.stdio_forward_port); 1839 1840 if ((in = dup(STDIN_FILENO)) == -1 || 1841 (out = dup(STDOUT_FILENO)) == -1) 1842 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1843 if ((c = channel_connect_stdio_fwd(ssh, options.stdio_forward_host, 1844 options.stdio_forward_port, in, out)) == NULL) 1845 fatal("%s: channel_connect_stdio_fwd failed", __func__); 1846 channel_register_cleanup(ssh, c->self, client_cleanup_stdio_fwd, 0); 1847 channel_register_open_confirm(ssh, c->self, ssh_stdio_confirm, NULL); 1848 } 1849 1850 static void 1851 ssh_init_forwarding(struct ssh *ssh, char **ifname) 1852 { 1853 int success = 0; 1854 int i; 1855 1856 if (options.exit_on_forward_failure) 1857 forward_confirms_pending = 0; /* track pending requests */ 1858 /* Initiate local TCP/IP port forwardings. */ 1859 for (i = 0; i < options.num_local_forwards; i++) { 1860 debug("Local connections to %.200s:%d forwarded to remote " 1861 "address %.200s:%d", 1862 (options.local_forwards[i].listen_path != NULL) ? 1863 options.local_forwards[i].listen_path : 1864 (options.local_forwards[i].listen_host == NULL) ? 1865 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") : 1866 options.local_forwards[i].listen_host, 1867 options.local_forwards[i].listen_port, 1868 (options.local_forwards[i].connect_path != NULL) ? 1869 options.local_forwards[i].connect_path : 1870 options.local_forwards[i].connect_host, 1871 options.local_forwards[i].connect_port); 1872 success += channel_setup_local_fwd_listener(ssh, 1873 &options.local_forwards[i], &options.fwd_opts); 1874 } 1875 if (i > 0 && success != i && options.exit_on_forward_failure) 1876 fatal("Could not request local forwarding."); 1877 if (i > 0 && success == 0) 1878 error("Could not request local forwarding."); 1879 1880 /* Initiate remote TCP/IP port forwardings. */ 1881 for (i = 0; i < options.num_remote_forwards; i++) { 1882 debug("Remote connections from %.200s:%d forwarded to " 1883 "local address %.200s:%d", 1884 (options.remote_forwards[i].listen_path != NULL) ? 1885 options.remote_forwards[i].listen_path : 1886 (options.remote_forwards[i].listen_host == NULL) ? 1887 "LOCALHOST" : options.remote_forwards[i].listen_host, 1888 options.remote_forwards[i].listen_port, 1889 (options.remote_forwards[i].connect_path != NULL) ? 1890 options.remote_forwards[i].connect_path : 1891 options.remote_forwards[i].connect_host, 1892 options.remote_forwards[i].connect_port); 1893 if ((options.remote_forwards[i].handle = 1894 channel_request_remote_forwarding(ssh, 1895 &options.remote_forwards[i])) >= 0) { 1896 client_register_global_confirm( 1897 ssh_confirm_remote_forward, 1898 &options.remote_forwards[i]); 1899 forward_confirms_pending++; 1900 } else if (options.exit_on_forward_failure) 1901 fatal("Could not request remote forwarding."); 1902 else 1903 logit("Warning: Could not request remote forwarding."); 1904 } 1905 1906 /* Initiate tunnel forwarding. */ 1907 if (options.tun_open != SSH_TUNMODE_NO) { 1908 if ((*ifname = client_request_tun_fwd(ssh, 1909 options.tun_open, options.tun_local, 1910 options.tun_remote, ssh_tun_confirm, NULL)) != NULL) 1911 forward_confirms_pending++; 1912 else if (options.exit_on_forward_failure) 1913 fatal("Could not request tunnel forwarding."); 1914 else 1915 error("Could not request tunnel forwarding."); 1916 } 1917 if (forward_confirms_pending > 0) { 1918 debug("%s: expecting replies for %d forwards", __func__, 1919 forward_confirms_pending); 1920 } 1921 } 1922 1923 static void 1924 check_agent_present(void) 1925 { 1926 int r; 1927 1928 if (options.forward_agent) { 1929 /* Clear agent forwarding if we don't have an agent. */ 1930 if ((r = ssh_get_authentication_socket(NULL)) != 0) { 1931 options.forward_agent = 0; 1932 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1933 debug("ssh_get_authentication_socket: %s", 1934 ssh_err(r)); 1935 } 1936 } 1937 } 1938 1939 static void 1940 ssh_session2_setup(struct ssh *ssh, int id, int success, void *arg) 1941 { 1942 extern char **environ; 1943 const char *display; 1944 int r, interactive = tty_flag; 1945 char *proto = NULL, *data = NULL; 1946 1947 if (!success) 1948 return; /* No need for error message, channels code sens one */ 1949 1950 display = getenv("DISPLAY"); 1951 if (display == NULL && options.forward_x11) 1952 debug("X11 forwarding requested but DISPLAY not set"); 1953 if (options.forward_x11 && client_x11_get_proto(ssh, display, 1954 options.xauth_location, options.forward_x11_trusted, 1955 options.forward_x11_timeout, &proto, &data) == 0) { 1956 /* Request forwarding with authentication spoofing. */ 1957 debug("Requesting X11 forwarding with authentication " 1958 "spoofing."); 1959 x11_request_forwarding_with_spoofing(ssh, id, display, proto, 1960 data, 1); 1961 client_expect_confirm(ssh, id, "X11 forwarding", CONFIRM_WARN); 1962 /* XXX exit_on_forward_failure */ 1963 interactive = 1; 1964 } 1965 1966 check_agent_present(); 1967 if (options.forward_agent) { 1968 debug("Requesting authentication agent forwarding."); 1969 channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0); 1970 if ((r = sshpkt_send(ssh)) != 0) 1971 fatal("%s: %s", __func__, ssh_err(r)); 1972 } 1973 1974 /* Tell the packet module whether this is an interactive session. */ 1975 ssh_packet_set_interactive(ssh, interactive, 1976 options.ip_qos_interactive, options.ip_qos_bulk); 1977 1978 client_session2_setup(ssh, id, tty_flag, subsystem_flag, getenv("TERM"), 1979 NULL, fileno(stdin), command, environ); 1980 } 1981 1982 /* open new channel for a session */ 1983 static int 1984 ssh_session2_open(struct ssh *ssh) 1985 { 1986 Channel *c; 1987 int window, packetmax, in, out, err; 1988 1989 if (stdin_null_flag) { 1990 in = open(_PATH_DEVNULL, O_RDONLY); 1991 } else { 1992 in = dup(STDIN_FILENO); 1993 } 1994 out = dup(STDOUT_FILENO); 1995 err = dup(STDERR_FILENO); 1996 1997 if (in == -1 || out == -1 || err == -1) 1998 fatal("dup() in/out/err failed"); 1999 2000 /* enable nonblocking unless tty */ 2001 if (!isatty(in)) 2002 set_nonblock(in); 2003 if (!isatty(out)) 2004 set_nonblock(out); 2005 if (!isatty(err)) 2006 set_nonblock(err); 2007 2008 window = CHAN_SES_WINDOW_DEFAULT; 2009 packetmax = CHAN_SES_PACKET_DEFAULT; 2010 if (tty_flag) { 2011 window >>= 1; 2012 packetmax >>= 1; 2013 } 2014 c = channel_new(ssh, 2015 "session", SSH_CHANNEL_OPENING, in, out, err, 2016 window, packetmax, CHAN_EXTENDED_WRITE, 2017 "client-session", /*nonblock*/0); 2018 2019 debug3("%s: channel_new: %d", __func__, c->self); 2020 2021 channel_send_open(ssh, c->self); 2022 if (!no_shell_flag) 2023 channel_register_open_confirm(ssh, c->self, 2024 ssh_session2_setup, NULL); 2025 2026 return c->self; 2027 } 2028 2029 static int 2030 ssh_session2(struct ssh *ssh, struct passwd *pw) 2031 { 2032 int r, devnull, id = -1; 2033 char *cp, *tun_fwd_ifname = NULL; 2034 2035 /* XXX should be pre-session */ 2036 if (!options.control_persist) 2037 ssh_init_stdio_forwarding(ssh); 2038 2039 ssh_init_forwarding(ssh, &tun_fwd_ifname); 2040 2041 if (options.local_command != NULL) { 2042 debug3("expanding LocalCommand: %s", options.local_command); 2043 cp = options.local_command; 2044 options.local_command = percent_expand(cp, 2045 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS, 2046 "d", pw->pw_dir, 2047 "h", host, 2048 "r", options.user, 2049 "u", pw->pw_name, 2050 "T", tun_fwd_ifname == NULL ? "NONE" : tun_fwd_ifname, 2051 (char *)NULL); 2052 debug3("expanded LocalCommand: %s", options.local_command); 2053 free(cp); 2054 } 2055 2056 /* Start listening for multiplex clients */ 2057 if (!ssh_packet_get_mux(ssh)) 2058 muxserver_listen(ssh); 2059 2060 /* 2061 * If we are in control persist mode and have a working mux listen 2062 * socket, then prepare to background ourselves and have a foreground 2063 * client attach as a control slave. 2064 * NB. we must save copies of the flags that we override for 2065 * the backgrounding, since we defer attachment of the slave until 2066 * after the connection is fully established (in particular, 2067 * async rfwd replies have been received for ExitOnForwardFailure). 2068 */ 2069 if (options.control_persist && muxserver_sock != -1) { 2070 ostdin_null_flag = stdin_null_flag; 2071 ono_shell_flag = no_shell_flag; 2072 orequest_tty = options.request_tty; 2073 otty_flag = tty_flag; 2074 stdin_null_flag = 1; 2075 no_shell_flag = 1; 2076 tty_flag = 0; 2077 if (!fork_after_authentication_flag) 2078 need_controlpersist_detach = 1; 2079 fork_after_authentication_flag = 1; 2080 } 2081 /* 2082 * ControlPersist mux listen socket setup failed, attempt the 2083 * stdio forward setup that we skipped earlier. 2084 */ 2085 if (options.control_persist && muxserver_sock == -1) 2086 ssh_init_stdio_forwarding(ssh); 2087 2088 if (!no_shell_flag) 2089 id = ssh_session2_open(ssh); 2090 else { 2091 ssh_packet_set_interactive(ssh, 2092 options.control_master == SSHCTL_MASTER_NO, 2093 options.ip_qos_interactive, options.ip_qos_bulk); 2094 } 2095 2096 /* If we don't expect to open a new session, then disallow it */ 2097 if (options.control_master == SSHCTL_MASTER_NO && 2098 (datafellows & SSH_NEW_OPENSSH)) { 2099 debug("Requesting no-more-sessions@openssh.com"); 2100 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 2101 (r = sshpkt_put_cstring(ssh, 2102 "no-more-sessions@openssh.com")) != 0 || 2103 (r = sshpkt_put_u8(ssh, 0)) != 0 || 2104 (r = sshpkt_send(ssh)) != 0) 2105 fatal("%s: %s", __func__, ssh_err(r)); 2106 } 2107 2108 /* Execute a local command */ 2109 if (options.local_command != NULL && 2110 options.permit_local_command) 2111 ssh_local_cmd(options.local_command); 2112 2113 /* 2114 * stdout is now owned by the session channel; clobber it here 2115 * so future channel closes are propagated to the local fd. 2116 * NB. this can only happen after LocalCommand has completed, 2117 * as it may want to write to stdout. 2118 */ 2119 if (!need_controlpersist_detach) { 2120 if ((devnull = open(_PATH_DEVNULL, O_WRONLY)) == -1) 2121 error("%s: open %s: %s", __func__, 2122 _PATH_DEVNULL, strerror(errno)); 2123 if (dup2(devnull, STDOUT_FILENO) == -1) 2124 fatal("%s: dup2() stdout failed", __func__); 2125 if (devnull > STDERR_FILENO) 2126 close(devnull); 2127 } 2128 2129 /* 2130 * If requested and we are not interested in replies to remote 2131 * forwarding requests, then let ssh continue in the background. 2132 */ 2133 if (fork_after_authentication_flag) { 2134 if (options.exit_on_forward_failure && 2135 options.num_remote_forwards > 0) { 2136 debug("deferring postauth fork until remote forward " 2137 "confirmation received"); 2138 } else 2139 fork_postauth(); 2140 } 2141 2142 return client_loop(ssh, tty_flag, tty_flag ? 2143 options.escape_char : SSH_ESCAPECHAR_NONE, id); 2144 } 2145 2146 /* Loads all IdentityFile and CertificateFile keys */ 2147 static void 2148 load_public_identity_files(struct passwd *pw) 2149 { 2150 char *filename, *cp; 2151 struct sshkey *public; 2152 int i; 2153 u_int n_ids, n_certs; 2154 char *identity_files[SSH_MAX_IDENTITY_FILES]; 2155 struct sshkey *identity_keys[SSH_MAX_IDENTITY_FILES]; 2156 int identity_file_userprovided[SSH_MAX_IDENTITY_FILES]; 2157 char *certificate_files[SSH_MAX_CERTIFICATE_FILES]; 2158 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES]; 2159 int certificate_file_userprovided[SSH_MAX_CERTIFICATE_FILES]; 2160 #ifdef ENABLE_PKCS11 2161 struct sshkey **keys = NULL; 2162 char **comments = NULL; 2163 int nkeys; 2164 #endif /* PKCS11 */ 2165 2166 n_ids = n_certs = 0; 2167 memset(identity_files, 0, sizeof(identity_files)); 2168 memset(identity_keys, 0, sizeof(identity_keys)); 2169 memset(identity_file_userprovided, 0, 2170 sizeof(identity_file_userprovided)); 2171 memset(certificate_files, 0, sizeof(certificate_files)); 2172 memset(certificates, 0, sizeof(certificates)); 2173 memset(certificate_file_userprovided, 0, 2174 sizeof(certificate_file_userprovided)); 2175 2176 #ifdef ENABLE_PKCS11 2177 if (options.pkcs11_provider != NULL && 2178 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 2179 (pkcs11_init(!options.batch_mode) == 0) && 2180 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 2181 &keys, &comments)) > 0) { 2182 for (i = 0; i < nkeys; i++) { 2183 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 2184 sshkey_free(keys[i]); 2185 free(comments[i]); 2186 continue; 2187 } 2188 identity_keys[n_ids] = keys[i]; 2189 identity_files[n_ids] = comments[i]; /* transferred */ 2190 n_ids++; 2191 } 2192 free(keys); 2193 free(comments); 2194 } 2195 #endif /* ENABLE_PKCS11 */ 2196 for (i = 0; i < options.num_identity_files; i++) { 2197 if (n_ids >= SSH_MAX_IDENTITY_FILES || 2198 strcasecmp(options.identity_files[i], "none") == 0) { 2199 free(options.identity_files[i]); 2200 options.identity_files[i] = NULL; 2201 continue; 2202 } 2203 cp = tilde_expand_filename(options.identity_files[i], getuid()); 2204 filename = default_client_percent_expand(cp, 2205 pw->pw_dir, host, options.user, pw->pw_name); 2206 free(cp); 2207 check_load(sshkey_load_public(filename, &public, NULL), 2208 filename, "pubkey"); 2209 debug("identity file %s type %d", filename, 2210 public ? public->type : -1); 2211 free(options.identity_files[i]); 2212 identity_files[n_ids] = filename; 2213 identity_keys[n_ids] = public; 2214 identity_file_userprovided[n_ids] = 2215 options.identity_file_userprovided[i]; 2216 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 2217 continue; 2218 2219 /* 2220 * If no certificates have been explicitly listed then try 2221 * to add the default certificate variant too. 2222 */ 2223 if (options.num_certificate_files != 0) 2224 continue; 2225 xasprintf(&cp, "%s-cert", filename); 2226 check_load(sshkey_load_public(cp, &public, NULL), 2227 filename, "pubkey"); 2228 debug("identity file %s type %d", cp, 2229 public ? public->type : -1); 2230 if (public == NULL) { 2231 free(cp); 2232 continue; 2233 } 2234 if (!sshkey_is_cert(public)) { 2235 debug("%s: key %s type %s is not a certificate", 2236 __func__, cp, sshkey_type(public)); 2237 sshkey_free(public); 2238 free(cp); 2239 continue; 2240 } 2241 /* NB. leave filename pointing to private key */ 2242 identity_files[n_ids] = xstrdup(filename); 2243 identity_keys[n_ids] = public; 2244 identity_file_userprovided[n_ids] = 2245 options.identity_file_userprovided[i]; 2246 n_ids++; 2247 } 2248 2249 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES) 2250 fatal("%s: too many certificates", __func__); 2251 for (i = 0; i < options.num_certificate_files; i++) { 2252 cp = tilde_expand_filename(options.certificate_files[i], 2253 getuid()); 2254 filename = default_client_percent_expand(cp, 2255 pw->pw_dir, host, options.user, pw->pw_name); 2256 free(cp); 2257 2258 check_load(sshkey_load_public(filename, &public, NULL), 2259 filename, "certificate"); 2260 debug("certificate file %s type %d", filename, 2261 public ? public->type : -1); 2262 free(options.certificate_files[i]); 2263 options.certificate_files[i] = NULL; 2264 if (public == NULL) { 2265 free(filename); 2266 continue; 2267 } 2268 if (!sshkey_is_cert(public)) { 2269 debug("%s: key %s type %s is not a certificate", 2270 __func__, filename, sshkey_type(public)); 2271 sshkey_free(public); 2272 free(filename); 2273 continue; 2274 } 2275 certificate_files[n_certs] = filename; 2276 certificates[n_certs] = public; 2277 certificate_file_userprovided[n_certs] = 2278 options.certificate_file_userprovided[i]; 2279 ++n_certs; 2280 } 2281 2282 options.num_identity_files = n_ids; 2283 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 2284 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 2285 memcpy(options.identity_file_userprovided, 2286 identity_file_userprovided, sizeof(identity_file_userprovided)); 2287 2288 options.num_certificate_files = n_certs; 2289 memcpy(options.certificate_files, 2290 certificate_files, sizeof(certificate_files)); 2291 memcpy(options.certificates, certificates, sizeof(certificates)); 2292 memcpy(options.certificate_file_userprovided, 2293 certificate_file_userprovided, 2294 sizeof(certificate_file_userprovided)); 2295 } 2296 2297 static void 2298 main_sigchld_handler(int sig) 2299 { 2300 int save_errno = errno; 2301 pid_t pid; 2302 int status; 2303 2304 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 2305 (pid == -1 && errno == EINTR)) 2306 ; 2307 errno = save_errno; 2308 } 2309