1 /* $OpenBSD: ssh.c,v 1.508 2019/10/31 21:18:28 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * Ssh client program. This program can be used to log into a remote machine. 7 * The software supports strong authentication, encryption, and forwarding 8 * of X11, TCP/IP, and authentication connections. 9 * 10 * As far as I am concerned, the code I have written for this software 11 * can be used freely for any purpose. Any derived versions of this 12 * software must be clearly marked as such, and if the derived work is 13 * incompatible with the protocol description in the RFC file, it must be 14 * called by a name other than "ssh" or "Secure Shell". 15 * 16 * Copyright (c) 1999 Niels Provos. All rights reserved. 17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved. 18 * 19 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu> 20 * in Canada (German citizen). 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the above copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 41 */ 42 43 #include <sys/types.h> 44 #include <sys/ioctl.h> 45 #include <sys/queue.h> 46 #include <sys/resource.h> 47 #include <sys/socket.h> 48 #include <sys/stat.h> 49 #include <sys/time.h> 50 #include <sys/wait.h> 51 52 #include <ctype.h> 53 #include <errno.h> 54 #include <fcntl.h> 55 #include <netdb.h> 56 #include <paths.h> 57 #include <pwd.h> 58 #include <signal.h> 59 #include <stddef.h> 60 #include <stdio.h> 61 #include <stdlib.h> 62 #include <string.h> 63 #include <unistd.h> 64 #include <limits.h> 65 #include <locale.h> 66 67 #ifdef WITH_OPENSSL 68 #include <openssl/evp.h> 69 #include <openssl/err.h> 70 #endif 71 72 #include "xmalloc.h" 73 #include "ssh.h" 74 #include "ssh2.h" 75 #include "canohost.h" 76 #include "compat.h" 77 #include "cipher.h" 78 #include "digest.h" 79 #include "packet.h" 80 #include "sshbuf.h" 81 #include "channels.h" 82 #include "sshkey.h" 83 #include "authfd.h" 84 #include "authfile.h" 85 #include "pathnames.h" 86 #include "dispatch.h" 87 #include "clientloop.h" 88 #include "log.h" 89 #include "misc.h" 90 #include "readconf.h" 91 #include "sshconnect.h" 92 #include "kex.h" 93 #include "mac.h" 94 #include "sshpty.h" 95 #include "match.h" 96 #include "msg.h" 97 #include "version.h" 98 #include "ssherr.h" 99 #include "myproposal.h" 100 101 #ifdef ENABLE_PKCS11 102 #include "ssh-pkcs11.h" 103 #endif 104 105 extern char *__progname; 106 107 /* Flag indicating whether debug mode is on. May be set on the command line. */ 108 int debug_flag = 0; 109 110 /* Flag indicating whether a tty should be requested */ 111 int tty_flag = 0; 112 113 /* don't exec a shell */ 114 int no_shell_flag = 0; 115 116 /* 117 * Flag indicating that nothing should be read from stdin. This can be set 118 * on the command line. 119 */ 120 int stdin_null_flag = 0; 121 122 /* 123 * Flag indicating that the current process should be backgrounded and 124 * a new slave launched in the foreground for ControlPersist. 125 */ 126 int need_controlpersist_detach = 0; 127 128 /* Copies of flags for ControlPersist foreground slave */ 129 int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty; 130 131 /* 132 * Flag indicating that ssh should fork after authentication. This is useful 133 * so that the passphrase can be entered manually, and then ssh goes to the 134 * background. 135 */ 136 int fork_after_authentication_flag = 0; 137 138 /* 139 * General data structure for command line options and options configurable 140 * in configuration files. See readconf.h. 141 */ 142 Options options; 143 144 /* optional user configfile */ 145 char *config = NULL; 146 147 /* 148 * Name of the host we are connecting to. This is the name given on the 149 * command line, or the Hostname specified for the user-supplied name in a 150 * configuration file. 151 */ 152 char *host; 153 154 /* Various strings used to to percent_expand() arguments */ 155 static char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 156 static char uidstr[32], *host_arg, *conn_hash_hex; 157 158 /* socket address the host resolves to */ 159 struct sockaddr_storage hostaddr; 160 161 /* Private host keys. */ 162 Sensitive sensitive_data; 163 164 /* command to be executed */ 165 struct sshbuf *command; 166 167 /* Should we execute a command or invoke a subsystem? */ 168 int subsystem_flag = 0; 169 170 /* # of replies received for global requests */ 171 static int remote_forward_confirms_received = 0; 172 173 /* mux.c */ 174 extern int muxserver_sock; 175 extern u_int muxclient_command; 176 177 /* Prints a help message to the user. This function never returns. */ 178 179 static void 180 usage(void) 181 { 182 fprintf(stderr, 183 "usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]\n" 184 " [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]\n" 185 " [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]\n" 186 " [-i identity_file] [-J [user@]host[:port]] [-L address]\n" 187 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" 188 " [-Q query_option] [-R address] [-S ctl_path] [-W host:port]\n" 189 " [-w local_tun[:remote_tun]] destination [command]\n" 190 ); 191 exit(255); 192 } 193 194 static int ssh_session2(struct ssh *, struct passwd *); 195 static void load_public_identity_files(struct passwd *); 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 * Attempt to resolve a host name / port to a set of addresses and 214 * optionally return any CNAMEs encountered along the way. 215 * Returns NULL on failure. 216 * NB. this function must operate with a options having undefined members. 217 */ 218 static struct addrinfo * 219 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen) 220 { 221 char strport[NI_MAXSERV]; 222 struct addrinfo hints, *res; 223 int gaierr; 224 LogLevel loglevel = SYSLOG_LEVEL_DEBUG1; 225 226 if (port <= 0) 227 port = default_ssh_port(); 228 229 snprintf(strport, sizeof strport, "%d", port); 230 memset(&hints, 0, sizeof(hints)); 231 hints.ai_family = options.address_family == -1 ? 232 AF_UNSPEC : options.address_family; 233 hints.ai_socktype = SOCK_STREAM; 234 if (cname != NULL) 235 hints.ai_flags = AI_CANONNAME; 236 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 237 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) 238 loglevel = SYSLOG_LEVEL_ERROR; 239 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", 240 __progname, name, ssh_gai_strerror(gaierr)); 241 return NULL; 242 } 243 if (cname != NULL && res->ai_canonname != NULL) { 244 if (strlcpy(cname, res->ai_canonname, clen) >= clen) { 245 error("%s: host \"%s\" cname \"%s\" too long (max %lu)", 246 __func__, name, res->ai_canonname, (u_long)clen); 247 if (clen > 0) 248 *cname = '\0'; 249 } 250 } 251 return res; 252 } 253 254 /* Returns non-zero if name can only be an address and not a hostname */ 255 static int 256 is_addr_fast(const char *name) 257 { 258 return (strchr(name, '%') != NULL || strchr(name, ':') != NULL || 259 strspn(name, "0123456789.") == strlen(name)); 260 } 261 262 /* Returns non-zero if name represents a valid, single address */ 263 static int 264 is_addr(const char *name) 265 { 266 char strport[NI_MAXSERV]; 267 struct addrinfo hints, *res; 268 269 if (is_addr_fast(name)) 270 return 1; 271 272 snprintf(strport, sizeof strport, "%u", default_ssh_port()); 273 memset(&hints, 0, sizeof(hints)); 274 hints.ai_family = options.address_family == -1 ? 275 AF_UNSPEC : options.address_family; 276 hints.ai_socktype = SOCK_STREAM; 277 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 278 if (getaddrinfo(name, strport, &hints, &res) != 0) 279 return 0; 280 if (res == NULL || res->ai_next != NULL) { 281 freeaddrinfo(res); 282 return 0; 283 } 284 freeaddrinfo(res); 285 return 1; 286 } 287 288 /* 289 * Attempt to resolve a numeric host address / port to a single address. 290 * Returns a canonical address string. 291 * Returns NULL on failure. 292 * NB. this function must operate with a options having undefined members. 293 */ 294 static struct addrinfo * 295 resolve_addr(const char *name, int port, char *caddr, size_t clen) 296 { 297 char addr[NI_MAXHOST], strport[NI_MAXSERV]; 298 struct addrinfo hints, *res; 299 int gaierr; 300 301 if (port <= 0) 302 port = default_ssh_port(); 303 snprintf(strport, sizeof strport, "%u", port); 304 memset(&hints, 0, sizeof(hints)); 305 hints.ai_family = options.address_family == -1 ? 306 AF_UNSPEC : options.address_family; 307 hints.ai_socktype = SOCK_STREAM; 308 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 309 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 310 debug2("%s: could not resolve name %.100s as address: %s", 311 __func__, name, ssh_gai_strerror(gaierr)); 312 return NULL; 313 } 314 if (res == NULL) { 315 debug("%s: getaddrinfo %.100s returned no addresses", 316 __func__, name); 317 return NULL; 318 } 319 if (res->ai_next != NULL) { 320 debug("%s: getaddrinfo %.100s returned multiple addresses", 321 __func__, name); 322 goto fail; 323 } 324 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen, 325 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) { 326 debug("%s: Could not format address for name %.100s: %s", 327 __func__, name, ssh_gai_strerror(gaierr)); 328 goto fail; 329 } 330 if (strlcpy(caddr, addr, clen) >= clen) { 331 error("%s: host \"%s\" addr \"%s\" too long (max %lu)", 332 __func__, name, addr, (u_long)clen); 333 if (clen > 0) 334 *caddr = '\0'; 335 fail: 336 freeaddrinfo(res); 337 return NULL; 338 } 339 return res; 340 } 341 342 /* 343 * Check whether the cname is a permitted replacement for the hostname 344 * and perform the replacement if it is. 345 * NB. this function must operate with a options having undefined members. 346 */ 347 static int 348 check_follow_cname(int direct, char **namep, const char *cname) 349 { 350 int i; 351 struct allowed_cname *rule; 352 353 if (*cname == '\0' || options.num_permitted_cnames == 0 || 354 strcmp(*namep, cname) == 0) 355 return 0; 356 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 357 return 0; 358 /* 359 * Don't attempt to canonicalize names that will be interpreted by 360 * a proxy or jump host unless the user specifically requests so. 361 */ 362 if (!direct && 363 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 364 return 0; 365 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname); 366 for (i = 0; i < options.num_permitted_cnames; i++) { 367 rule = options.permitted_cnames + i; 368 if (match_pattern_list(*namep, rule->source_list, 1) != 1 || 369 match_pattern_list(cname, rule->target_list, 1) != 1) 370 continue; 371 verbose("Canonicalized DNS aliased hostname " 372 "\"%s\" => \"%s\"", *namep, cname); 373 free(*namep); 374 *namep = xstrdup(cname); 375 return 1; 376 } 377 return 0; 378 } 379 380 /* 381 * Attempt to resolve the supplied hostname after applying the user's 382 * canonicalization rules. Returns the address list for the host or NULL 383 * if no name was found after canonicalization. 384 * NB. this function must operate with a options having undefined members. 385 */ 386 static struct addrinfo * 387 resolve_canonicalize(char **hostp, int port) 388 { 389 int i, direct, ndots; 390 char *cp, *fullhost, newname[NI_MAXHOST]; 391 struct addrinfo *addrs; 392 393 /* 394 * Attempt to canonicalise addresses, regardless of 395 * whether hostname canonicalisation was requested 396 */ 397 if ((addrs = resolve_addr(*hostp, port, 398 newname, sizeof(newname))) != NULL) { 399 debug2("%s: hostname %.100s is address", __func__, *hostp); 400 if (strcasecmp(*hostp, newname) != 0) { 401 debug2("%s: canonicalised address \"%s\" => \"%s\"", 402 __func__, *hostp, newname); 403 free(*hostp); 404 *hostp = xstrdup(newname); 405 } 406 return addrs; 407 } 408 409 /* 410 * If this looks like an address but didn't parse as one, it might 411 * be an address with an invalid interface scope. Skip further 412 * attempts at canonicalisation. 413 */ 414 if (is_addr_fast(*hostp)) { 415 debug("%s: hostname %.100s is an unrecognised address", 416 __func__, *hostp); 417 return NULL; 418 } 419 420 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 421 return NULL; 422 423 /* 424 * Don't attempt to canonicalize names that will be interpreted by 425 * a proxy unless the user specifically requests so. 426 */ 427 direct = option_clear_or_none(options.proxy_command) && 428 options.jump_host == NULL; 429 if (!direct && 430 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 431 return NULL; 432 433 /* If domain name is anchored, then resolve it now */ 434 if ((*hostp)[strlen(*hostp) - 1] == '.') { 435 debug3("%s: name is fully qualified", __func__); 436 fullhost = xstrdup(*hostp); 437 if ((addrs = resolve_host(fullhost, port, 0, 438 newname, sizeof(newname))) != NULL) 439 goto found; 440 free(fullhost); 441 goto notfound; 442 } 443 444 /* Don't apply canonicalization to sufficiently-qualified hostnames */ 445 ndots = 0; 446 for (cp = *hostp; *cp != '\0'; cp++) { 447 if (*cp == '.') 448 ndots++; 449 } 450 if (ndots > options.canonicalize_max_dots) { 451 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)", 452 __func__, *hostp, options.canonicalize_max_dots); 453 return NULL; 454 } 455 /* Attempt each supplied suffix */ 456 for (i = 0; i < options.num_canonical_domains; i++) { 457 *newname = '\0'; 458 xasprintf(&fullhost, "%s.%s.", *hostp, 459 options.canonical_domains[i]); 460 debug3("%s: attempting \"%s\" => \"%s\"", __func__, 461 *hostp, fullhost); 462 if ((addrs = resolve_host(fullhost, port, 0, 463 newname, sizeof(newname))) == NULL) { 464 free(fullhost); 465 continue; 466 } 467 found: 468 /* Remove trailing '.' */ 469 fullhost[strlen(fullhost) - 1] = '\0'; 470 /* Follow CNAME if requested */ 471 if (!check_follow_cname(direct, &fullhost, newname)) { 472 debug("Canonicalized hostname \"%s\" => \"%s\"", 473 *hostp, fullhost); 474 } 475 free(*hostp); 476 *hostp = fullhost; 477 return addrs; 478 } 479 notfound: 480 if (!options.canonicalize_fallback_local) 481 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); 482 debug2("%s: host %s not found in any suffix", __func__, *hostp); 483 return NULL; 484 } 485 486 /* 487 * Check the result of hostkey loading, ignoring some errors and 488 * fatal()ing for others. 489 */ 490 static void 491 check_load(int r, const char *path, const char *message) 492 { 493 switch (r) { 494 case 0: 495 break; 496 case SSH_ERR_INTERNAL_ERROR: 497 case SSH_ERR_ALLOC_FAIL: 498 fatal("load %s \"%s\": %s", message, path, ssh_err(r)); 499 case SSH_ERR_SYSTEM_ERROR: 500 /* Ignore missing files */ 501 if (errno == ENOENT) 502 break; 503 /* FALLTHROUGH */ 504 default: 505 error("load %s \"%s\": %s", message, path, ssh_err(r)); 506 break; 507 } 508 } 509 510 /* 511 * Read per-user configuration file. Ignore the system wide config 512 * file if the user specifies a config file on the command line. 513 */ 514 static void 515 process_config_files(const char *host_name, struct passwd *pw, int final_pass, 516 int *want_final_pass) 517 { 518 char buf[PATH_MAX]; 519 int r; 520 521 if (config != NULL) { 522 if (strcasecmp(config, "none") != 0 && 523 !read_config_file(config, pw, host, host_name, &options, 524 SSHCONF_USERCONF | (final_pass ? SSHCONF_FINAL : 0), 525 want_final_pass)) 526 fatal("Can't open user config file %.100s: " 527 "%.100s", config, strerror(errno)); 528 } else { 529 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 530 _PATH_SSH_USER_CONFFILE); 531 if (r > 0 && (size_t)r < sizeof(buf)) 532 (void)read_config_file(buf, pw, host, host_name, 533 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF | 534 (final_pass ? SSHCONF_FINAL : 0), want_final_pass); 535 536 /* Read systemwide configuration file after user config. */ 537 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, 538 host, host_name, &options, 539 final_pass ? SSHCONF_FINAL : 0, want_final_pass); 540 } 541 } 542 543 /* Rewrite the port number in an addrinfo list of addresses */ 544 static void 545 set_addrinfo_port(struct addrinfo *addrs, int port) 546 { 547 struct addrinfo *addr; 548 549 for (addr = addrs; addr != NULL; addr = addr->ai_next) { 550 switch (addr->ai_family) { 551 case AF_INET: 552 ((struct sockaddr_in *)addr->ai_addr)-> 553 sin_port = htons(port); 554 break; 555 case AF_INET6: 556 ((struct sockaddr_in6 *)addr->ai_addr)-> 557 sin6_port = htons(port); 558 break; 559 } 560 } 561 } 562 563 /* 564 * Main program for the ssh client. 565 */ 566 int 567 main(int ac, char **av) 568 { 569 struct ssh *ssh = NULL; 570 int i, r, opt, exit_status, use_syslog, direct, timeout_ms; 571 int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0; 572 char *p, *cp, *line, *argv0, buf[PATH_MAX], *logfile; 573 char cname[NI_MAXHOST]; 574 struct stat st; 575 struct passwd *pw; 576 extern int optind, optreset; 577 extern char *optarg; 578 struct Forward fwd; 579 struct addrinfo *addrs = NULL; 580 struct ssh_digest_ctx *md; 581 u_char conn_hash[SSH_DIGEST_MAX_LENGTH]; 582 583 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 584 sanitise_stdfd(); 585 586 /* 587 * Discard other fds that are hanging around. These can cause problem 588 * with backgrounded ssh processes started by ControlPersist. 589 */ 590 closefrom(STDERR_FILENO + 1); 591 592 if (getuid() != geteuid()) 593 fatal("ssh setuid not supported."); 594 if (getgid() != getegid()) 595 fatal("ssh setgid not supported."); 596 597 /* Get user data. */ 598 pw = getpwuid(getuid()); 599 if (!pw) { 600 logit("No user exists for uid %lu", (u_long)getuid()); 601 exit(255); 602 } 603 /* Take a copy of the returned structure. */ 604 pw = pwcopy(pw); 605 606 /* 607 * Set our umask to something reasonable, as some files are created 608 * with the default umask. This will make them world-readable but 609 * writable only by the owner, which is ok for all files for which we 610 * don't set the modes explicitly. 611 */ 612 umask(022); 613 614 setlocale(LC_CTYPE, ""); 615 616 /* 617 * Initialize option structure to indicate that no values have been 618 * set. 619 */ 620 initialize_options(&options); 621 622 /* 623 * Prepare main ssh transport/connection structures 624 */ 625 if ((ssh = ssh_alloc_session_state()) == NULL) 626 fatal("Couldn't allocate session state"); 627 channel_init_channels(ssh); 628 629 /* Parse command-line arguments. */ 630 host = NULL; 631 use_syslog = 0; 632 logfile = NULL; 633 argv0 = av[0]; 634 635 again: 636 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 637 "AB:CD:E:F:GI:J:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { 638 switch (opt) { 639 case '1': 640 fatal("SSH protocol v.1 is no longer supported"); 641 break; 642 case '2': 643 /* Ignored */ 644 break; 645 case '4': 646 options.address_family = AF_INET; 647 break; 648 case '6': 649 options.address_family = AF_INET6; 650 break; 651 case 'n': 652 stdin_null_flag = 1; 653 break; 654 case 'f': 655 fork_after_authentication_flag = 1; 656 stdin_null_flag = 1; 657 break; 658 case 'x': 659 options.forward_x11 = 0; 660 break; 661 case 'X': 662 options.forward_x11 = 1; 663 break; 664 case 'y': 665 use_syslog = 1; 666 break; 667 case 'E': 668 logfile = optarg; 669 break; 670 case 'G': 671 config_test = 1; 672 break; 673 case 'Y': 674 options.forward_x11 = 1; 675 options.forward_x11_trusted = 1; 676 break; 677 case 'g': 678 options.fwd_opts.gateway_ports = 1; 679 break; 680 case 'O': 681 if (options.stdio_forward_host != NULL) 682 fatal("Cannot specify multiplexing " 683 "command with -W"); 684 else if (muxclient_command != 0) 685 fatal("Multiplexing command already specified"); 686 if (strcmp(optarg, "check") == 0) 687 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 688 else if (strcmp(optarg, "forward") == 0) 689 muxclient_command = SSHMUX_COMMAND_FORWARD; 690 else if (strcmp(optarg, "exit") == 0) 691 muxclient_command = SSHMUX_COMMAND_TERMINATE; 692 else if (strcmp(optarg, "stop") == 0) 693 muxclient_command = SSHMUX_COMMAND_STOP; 694 else if (strcmp(optarg, "cancel") == 0) 695 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 696 else if (strcmp(optarg, "proxy") == 0) 697 muxclient_command = SSHMUX_COMMAND_PROXY; 698 else 699 fatal("Invalid multiplex command."); 700 break; 701 case 'P': /* deprecated */ 702 break; 703 case 'Q': 704 cp = NULL; 705 if (strcmp(optarg, "cipher") == 0) 706 cp = cipher_alg_list('\n', 0); 707 else if (strcmp(optarg, "cipher-auth") == 0) 708 cp = cipher_alg_list('\n', 1); 709 else if (strcmp(optarg, "mac") == 0) 710 cp = mac_alg_list('\n'); 711 else if (strcmp(optarg, "kex") == 0) 712 cp = kex_alg_list('\n'); 713 else if (strcmp(optarg, "key") == 0) 714 cp = sshkey_alg_list(0, 0, 0, '\n'); 715 else if (strcmp(optarg, "key-cert") == 0) 716 cp = sshkey_alg_list(1, 0, 0, '\n'); 717 else if (strcmp(optarg, "key-plain") == 0) 718 cp = sshkey_alg_list(0, 1, 0, '\n'); 719 else if (strcmp(optarg, "sig") == 0) 720 cp = sshkey_alg_list(0, 1, 1, '\n'); 721 else if (strcmp(optarg, "protocol-version") == 0) 722 cp = xstrdup("2"); 723 else if (strcmp(optarg, "help") == 0) { 724 cp = xstrdup( 725 "cipher\ncipher-auth\nkex\nkey\n" 726 "key-cert\nkey-plain\nmac\n" 727 "protocol-version\nsig"); 728 } 729 if (cp == NULL) 730 fatal("Unsupported query \"%s\"", optarg); 731 printf("%s\n", cp); 732 free(cp); 733 exit(0); 734 break; 735 case 'a': 736 options.forward_agent = 0; 737 break; 738 case 'A': 739 options.forward_agent = 1; 740 break; 741 case 'k': 742 options.gss_deleg_creds = 0; 743 break; 744 case 'K': 745 options.gss_authentication = 1; 746 options.gss_deleg_creds = 1; 747 break; 748 case 'i': 749 p = tilde_expand_filename(optarg, getuid()); 750 if (stat(p, &st) == -1) 751 fprintf(stderr, "Warning: Identity file %s " 752 "not accessible: %s.\n", p, 753 strerror(errno)); 754 else 755 add_identity_file(&options, NULL, p, 1); 756 free(p); 757 break; 758 case 'I': 759 #ifdef ENABLE_PKCS11 760 free(options.pkcs11_provider); 761 options.pkcs11_provider = xstrdup(optarg); 762 #else 763 fprintf(stderr, "no support for PKCS#11.\n"); 764 #endif 765 break; 766 case 'J': 767 if (options.jump_host != NULL) { 768 fatal("Only a single -J option is permitted " 769 "(use commas to separate multiple " 770 "jump hops)"); 771 } 772 if (options.proxy_command != NULL) 773 fatal("Cannot specify -J with ProxyCommand"); 774 if (parse_jump(optarg, &options, 1) == -1) 775 fatal("Invalid -J argument"); 776 options.proxy_command = xstrdup("none"); 777 break; 778 case 't': 779 if (options.request_tty == REQUEST_TTY_YES) 780 options.request_tty = REQUEST_TTY_FORCE; 781 else 782 options.request_tty = REQUEST_TTY_YES; 783 break; 784 case 'v': 785 if (debug_flag == 0) { 786 debug_flag = 1; 787 options.log_level = SYSLOG_LEVEL_DEBUG1; 788 } else { 789 if (options.log_level < SYSLOG_LEVEL_DEBUG3) { 790 debug_flag++; 791 options.log_level++; 792 } 793 } 794 break; 795 case 'V': 796 fprintf(stderr, "%s, %s\n", 797 SSH_VERSION, 798 #ifdef WITH_OPENSSL 799 OpenSSL_version(OPENSSL_VERSION) 800 #else 801 "without OpenSSL" 802 #endif 803 ); 804 if (opt == 'V') 805 exit(0); 806 break; 807 case 'w': 808 if (options.tun_open == -1) 809 options.tun_open = SSH_TUNMODE_DEFAULT; 810 options.tun_local = a2tun(optarg, &options.tun_remote); 811 if (options.tun_local == SSH_TUNID_ERR) { 812 fprintf(stderr, 813 "Bad tun device '%s'\n", optarg); 814 exit(255); 815 } 816 break; 817 case 'W': 818 if (options.stdio_forward_host != NULL) 819 fatal("stdio forward already specified"); 820 if (muxclient_command != 0) 821 fatal("Cannot specify stdio forward with -O"); 822 if (parse_forward(&fwd, optarg, 1, 0)) { 823 options.stdio_forward_host = fwd.listen_host; 824 options.stdio_forward_port = fwd.listen_port; 825 free(fwd.connect_host); 826 } else { 827 fprintf(stderr, 828 "Bad stdio forwarding specification '%s'\n", 829 optarg); 830 exit(255); 831 } 832 options.request_tty = REQUEST_TTY_NO; 833 no_shell_flag = 1; 834 break; 835 case 'q': 836 options.log_level = SYSLOG_LEVEL_QUIET; 837 break; 838 case 'e': 839 if (optarg[0] == '^' && optarg[2] == 0 && 840 (u_char) optarg[1] >= 64 && 841 (u_char) optarg[1] < 128) 842 options.escape_char = (u_char) optarg[1] & 31; 843 else if (strlen(optarg) == 1) 844 options.escape_char = (u_char) optarg[0]; 845 else if (strcmp(optarg, "none") == 0) 846 options.escape_char = SSH_ESCAPECHAR_NONE; 847 else { 848 fprintf(stderr, "Bad escape character '%s'.\n", 849 optarg); 850 exit(255); 851 } 852 break; 853 case 'c': 854 if (!ciphers_valid(*optarg == '+' || *optarg == '^' ? 855 optarg + 1 : optarg)) { 856 fprintf(stderr, "Unknown cipher type '%s'\n", 857 optarg); 858 exit(255); 859 } 860 free(options.ciphers); 861 options.ciphers = xstrdup(optarg); 862 break; 863 case 'm': 864 if (mac_valid(optarg)) { 865 free(options.macs); 866 options.macs = xstrdup(optarg); 867 } else { 868 fprintf(stderr, "Unknown mac type '%s'\n", 869 optarg); 870 exit(255); 871 } 872 break; 873 case 'M': 874 if (options.control_master == SSHCTL_MASTER_YES) 875 options.control_master = SSHCTL_MASTER_ASK; 876 else 877 options.control_master = SSHCTL_MASTER_YES; 878 break; 879 case 'p': 880 if (options.port == -1) { 881 options.port = a2port(optarg); 882 if (options.port <= 0) { 883 fprintf(stderr, "Bad port '%s'\n", 884 optarg); 885 exit(255); 886 } 887 } 888 break; 889 case 'l': 890 if (options.user == NULL) 891 options.user = optarg; 892 break; 893 894 case 'L': 895 if (parse_forward(&fwd, optarg, 0, 0)) 896 add_local_forward(&options, &fwd); 897 else { 898 fprintf(stderr, 899 "Bad local forwarding specification '%s'\n", 900 optarg); 901 exit(255); 902 } 903 break; 904 905 case 'R': 906 if (parse_forward(&fwd, optarg, 0, 1) || 907 parse_forward(&fwd, optarg, 1, 1)) { 908 add_remote_forward(&options, &fwd); 909 } else { 910 fprintf(stderr, 911 "Bad remote forwarding specification " 912 "'%s'\n", optarg); 913 exit(255); 914 } 915 break; 916 917 case 'D': 918 if (parse_forward(&fwd, optarg, 1, 0)) { 919 add_local_forward(&options, &fwd); 920 } else { 921 fprintf(stderr, 922 "Bad dynamic forwarding specification " 923 "'%s'\n", optarg); 924 exit(255); 925 } 926 break; 927 928 case 'C': 929 options.compression = 1; 930 break; 931 case 'N': 932 no_shell_flag = 1; 933 options.request_tty = REQUEST_TTY_NO; 934 break; 935 case 'T': 936 options.request_tty = REQUEST_TTY_NO; 937 break; 938 case 'o': 939 line = xstrdup(optarg); 940 if (process_config_line(&options, pw, 941 host ? host : "", host ? host : "", line, 942 "command-line", 0, NULL, SSHCONF_USERCONF) != 0) 943 exit(255); 944 free(line); 945 break; 946 case 's': 947 subsystem_flag = 1; 948 break; 949 case 'S': 950 free(options.control_path); 951 options.control_path = xstrdup(optarg); 952 break; 953 case 'b': 954 options.bind_address = optarg; 955 break; 956 case 'B': 957 options.bind_interface = optarg; 958 break; 959 case 'F': 960 config = optarg; 961 break; 962 default: 963 usage(); 964 } 965 } 966 967 if (optind > 1 && strcmp(av[optind - 1], "--") == 0) 968 opt_terminated = 1; 969 970 ac -= optind; 971 av += optind; 972 973 if (ac > 0 && !host) { 974 int tport; 975 char *tuser; 976 switch (parse_ssh_uri(*av, &tuser, &host, &tport)) { 977 case -1: 978 usage(); 979 break; 980 case 0: 981 if (options.user == NULL) { 982 options.user = tuser; 983 tuser = NULL; 984 } 985 free(tuser); 986 if (options.port == -1 && tport != -1) 987 options.port = tport; 988 break; 989 default: 990 p = xstrdup(*av); 991 cp = strrchr(p, '@'); 992 if (cp != NULL) { 993 if (cp == p) 994 usage(); 995 if (options.user == NULL) { 996 options.user = p; 997 p = NULL; 998 } 999 *cp++ = '\0'; 1000 host = xstrdup(cp); 1001 free(p); 1002 } else 1003 host = p; 1004 break; 1005 } 1006 if (ac > 1 && !opt_terminated) { 1007 optind = optreset = 1; 1008 goto again; 1009 } 1010 ac--, av++; 1011 } 1012 1013 /* Check that we got a host name. */ 1014 if (!host) 1015 usage(); 1016 1017 host_arg = xstrdup(host); 1018 1019 #ifdef WITH_OPENSSL 1020 OpenSSL_add_all_algorithms(); 1021 ERR_load_crypto_strings(); 1022 #endif 1023 1024 /* Initialize the command to execute on remote host. */ 1025 if ((command = sshbuf_new()) == NULL) 1026 fatal("sshbuf_new failed"); 1027 1028 /* 1029 * Save the command to execute on the remote host in a buffer. There 1030 * is no limit on the length of the command, except by the maximum 1031 * packet size. Also sets the tty flag if there is no command. 1032 */ 1033 if (!ac) { 1034 /* No command specified - execute shell on a tty. */ 1035 if (subsystem_flag) { 1036 fprintf(stderr, 1037 "You must specify a subsystem to invoke.\n"); 1038 usage(); 1039 } 1040 } else { 1041 /* A command has been specified. Store it into the buffer. */ 1042 for (i = 0; i < ac; i++) { 1043 if ((r = sshbuf_putf(command, "%s%s", 1044 i ? " " : "", av[i])) != 0) 1045 fatal("%s: buffer error: %s", 1046 __func__, ssh_err(r)); 1047 } 1048 } 1049 1050 /* 1051 * Initialize "log" output. Since we are the client all output 1052 * goes to stderr unless otherwise specified by -y or -E. 1053 */ 1054 if (use_syslog && logfile != NULL) 1055 fatal("Can't specify both -y and -E"); 1056 if (logfile != NULL) 1057 log_redirect_stderr_to(logfile); 1058 log_init(argv0, 1059 options.log_level == SYSLOG_LEVEL_NOT_SET ? 1060 SYSLOG_LEVEL_INFO : options.log_level, 1061 options.log_facility == SYSLOG_FACILITY_NOT_SET ? 1062 SYSLOG_FACILITY_USER : options.log_facility, 1063 !use_syslog); 1064 1065 if (debug_flag) 1066 logit("%s, %s", SSH_VERSION, 1067 #ifdef WITH_OPENSSL 1068 OpenSSL_version(OPENSSL_VERSION) 1069 #else 1070 "without OpenSSL" 1071 #endif 1072 ); 1073 1074 /* Parse the configuration files */ 1075 process_config_files(host_arg, pw, 0, &want_final_pass); 1076 if (want_final_pass) 1077 debug("configuration requests final Match pass"); 1078 1079 /* Hostname canonicalisation needs a few options filled. */ 1080 fill_default_options_for_canonicalization(&options); 1081 1082 /* If the user has replaced the hostname then take it into use now */ 1083 if (options.hostname != NULL) { 1084 /* NB. Please keep in sync with readconf.c:match_cfg_line() */ 1085 cp = percent_expand(options.hostname, 1086 "h", host, (char *)NULL); 1087 free(host); 1088 host = cp; 1089 free(options.hostname); 1090 options.hostname = xstrdup(host); 1091 } 1092 1093 /* Don't lowercase addresses, they will be explicitly canonicalised */ 1094 if ((was_addr = is_addr(host)) == 0) 1095 lowercase(host); 1096 1097 /* 1098 * Try to canonicalize if requested by configuration or the 1099 * hostname is an address. 1100 */ 1101 if (options.canonicalize_hostname != SSH_CANONICALISE_NO || was_addr) 1102 addrs = resolve_canonicalize(&host, options.port); 1103 1104 /* 1105 * If CanonicalizePermittedCNAMEs have been specified but 1106 * other canonicalization did not happen (by not being requested 1107 * or by failing with fallback) then the hostname may still be changed 1108 * as a result of CNAME following. 1109 * 1110 * Try to resolve the bare hostname name using the system resolver's 1111 * usual search rules and then apply the CNAME follow rules. 1112 * 1113 * Skip the lookup if a ProxyCommand is being used unless the user 1114 * has specifically requested canonicalisation for this case via 1115 * CanonicalizeHostname=always 1116 */ 1117 direct = option_clear_or_none(options.proxy_command) && 1118 options.jump_host == NULL; 1119 if (addrs == NULL && options.num_permitted_cnames != 0 && (direct || 1120 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { 1121 if ((addrs = resolve_host(host, options.port, 1122 direct, cname, sizeof(cname))) == NULL) { 1123 /* Don't fatal proxied host names not in the DNS */ 1124 if (direct) 1125 cleanup_exit(255); /* logged in resolve_host */ 1126 } else 1127 check_follow_cname(direct, &host, cname); 1128 } 1129 1130 /* 1131 * If canonicalisation is enabled then re-parse the configuration 1132 * files as new stanzas may match. 1133 */ 1134 if (options.canonicalize_hostname != 0 && !want_final_pass) { 1135 debug("hostname canonicalisation enabled, " 1136 "will re-parse configuration"); 1137 want_final_pass = 1; 1138 } 1139 1140 if (want_final_pass) { 1141 debug("re-parsing configuration"); 1142 free(options.hostname); 1143 options.hostname = xstrdup(host); 1144 process_config_files(host_arg, pw, 1, NULL); 1145 /* 1146 * Address resolution happens early with canonicalisation 1147 * enabled and the port number may have changed since, so 1148 * reset it in address list 1149 */ 1150 if (addrs != NULL && options.port > 0) 1151 set_addrinfo_port(addrs, options.port); 1152 } 1153 1154 /* Fill configuration defaults. */ 1155 fill_default_options(&options); 1156 1157 /* 1158 * If ProxyJump option specified, then construct a ProxyCommand now. 1159 */ 1160 if (options.jump_host != NULL) { 1161 char port_s[8]; 1162 const char *sshbin = argv0; 1163 1164 /* 1165 * Try to use SSH indicated by argv[0], but fall back to 1166 * "ssh" if it appears unavailable. 1167 */ 1168 if (strchr(argv0, '/') != NULL && access(argv0, X_OK) != 0) 1169 sshbin = "ssh"; 1170 1171 /* Consistency check */ 1172 if (options.proxy_command != NULL) 1173 fatal("inconsistent options: ProxyCommand+ProxyJump"); 1174 /* Never use FD passing for ProxyJump */ 1175 options.proxy_use_fdpass = 0; 1176 snprintf(port_s, sizeof(port_s), "%d", options.jump_port); 1177 xasprintf(&options.proxy_command, 1178 "%s%s%s%s%s%s%s%s%s%s%.*s -W '[%%h]:%%p' %s", 1179 sshbin, 1180 /* Optional "-l user" argument if jump_user set */ 1181 options.jump_user == NULL ? "" : " -l ", 1182 options.jump_user == NULL ? "" : options.jump_user, 1183 /* Optional "-p port" argument if jump_port set */ 1184 options.jump_port <= 0 ? "" : " -p ", 1185 options.jump_port <= 0 ? "" : port_s, 1186 /* Optional additional jump hosts ",..." */ 1187 options.jump_extra == NULL ? "" : " -J ", 1188 options.jump_extra == NULL ? "" : options.jump_extra, 1189 /* Optional "-F" argumment if -F specified */ 1190 config == NULL ? "" : " -F ", 1191 config == NULL ? "" : config, 1192 /* Optional "-v" arguments if -v set */ 1193 debug_flag ? " -" : "", 1194 debug_flag, "vvv", 1195 /* Mandatory hostname */ 1196 options.jump_host); 1197 debug("Setting implicit ProxyCommand from ProxyJump: %s", 1198 options.proxy_command); 1199 } 1200 1201 if (options.port == 0) 1202 options.port = default_ssh_port(); 1203 channel_set_af(ssh, options.address_family); 1204 1205 /* Tidy and check options */ 1206 if (options.host_key_alias != NULL) 1207 lowercase(options.host_key_alias); 1208 if (options.proxy_command != NULL && 1209 strcmp(options.proxy_command, "-") == 0 && 1210 options.proxy_use_fdpass) 1211 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); 1212 if (options.control_persist && 1213 options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 1214 debug("UpdateHostKeys=ask is incompatible with ControlPersist; " 1215 "disabling"); 1216 options.update_hostkeys = 0; 1217 } 1218 if (options.connection_attempts <= 0) 1219 fatal("Invalid number of ConnectionAttempts"); 1220 1221 if (sshbuf_len(command) != 0 && options.remote_command != NULL) 1222 fatal("Cannot execute command-line and remote command."); 1223 1224 /* Cannot fork to background if no command. */ 1225 if (fork_after_authentication_flag && sshbuf_len(command) == 0 && 1226 options.remote_command == NULL && !no_shell_flag) 1227 fatal("Cannot fork into background without a command " 1228 "to execute."); 1229 1230 /* reinit */ 1231 log_init(argv0, options.log_level, options.log_facility, !use_syslog); 1232 1233 if (options.request_tty == REQUEST_TTY_YES || 1234 options.request_tty == REQUEST_TTY_FORCE) 1235 tty_flag = 1; 1236 1237 /* Allocate a tty by default if no command specified. */ 1238 if (sshbuf_len(command) == 0 && options.remote_command == NULL) 1239 tty_flag = options.request_tty != REQUEST_TTY_NO; 1240 1241 /* Force no tty */ 1242 if (options.request_tty == REQUEST_TTY_NO || 1243 (muxclient_command && muxclient_command != SSHMUX_COMMAND_PROXY)) 1244 tty_flag = 0; 1245 /* Do not allocate a tty if stdin is not a tty. */ 1246 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 1247 options.request_tty != REQUEST_TTY_FORCE) { 1248 if (tty_flag) 1249 logit("Pseudo-terminal will not be allocated because " 1250 "stdin is not a terminal."); 1251 tty_flag = 0; 1252 } 1253 1254 if (options.user == NULL) 1255 options.user = xstrdup(pw->pw_name); 1256 1257 /* Set up strings used to percent_expand() arguments */ 1258 if (gethostname(thishost, sizeof(thishost)) == -1) 1259 fatal("gethostname: %s", strerror(errno)); 1260 strlcpy(shorthost, thishost, sizeof(shorthost)); 1261 shorthost[strcspn(thishost, ".")] = '\0'; 1262 snprintf(portstr, sizeof(portstr), "%d", options.port); 1263 snprintf(uidstr, sizeof(uidstr), "%llu", 1264 (unsigned long long)pw->pw_uid); 1265 1266 if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL || 1267 ssh_digest_update(md, thishost, strlen(thishost)) < 0 || 1268 ssh_digest_update(md, host, strlen(host)) < 0 || 1269 ssh_digest_update(md, portstr, strlen(portstr)) < 0 || 1270 ssh_digest_update(md, options.user, strlen(options.user)) < 0 || 1271 ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0) 1272 fatal("%s: mux digest failed", __func__); 1273 ssh_digest_free(md); 1274 conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1)); 1275 1276 /* 1277 * Expand tokens in arguments. NB. LocalCommand is expanded later, 1278 * after port-forwarding is set up, so it may pick up any local 1279 * tunnel interface name allocated. 1280 */ 1281 if (options.remote_command != NULL) { 1282 debug3("expanding RemoteCommand: %s", options.remote_command); 1283 cp = options.remote_command; 1284 options.remote_command = percent_expand(cp, 1285 "C", conn_hash_hex, 1286 "L", shorthost, 1287 "d", pw->pw_dir, 1288 "h", host, 1289 "i", uidstr, 1290 "l", thishost, 1291 "n", host_arg, 1292 "p", portstr, 1293 "r", options.user, 1294 "u", pw->pw_name, 1295 (char *)NULL); 1296 debug3("expanded RemoteCommand: %s", options.remote_command); 1297 free(cp); 1298 if ((r = sshbuf_put(command, options.remote_command, 1299 strlen(options.remote_command))) != 0) 1300 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1301 } 1302 1303 if (options.control_path != NULL) { 1304 cp = tilde_expand_filename(options.control_path, getuid()); 1305 free(options.control_path); 1306 options.control_path = percent_expand(cp, 1307 "C", conn_hash_hex, 1308 "L", shorthost, 1309 "h", host, 1310 "i", uidstr, 1311 "l", thishost, 1312 "n", host_arg, 1313 "p", portstr, 1314 "r", options.user, 1315 "u", pw->pw_name, 1316 "i", uidstr, 1317 (char *)NULL); 1318 free(cp); 1319 } 1320 1321 if (config_test) { 1322 dump_client_config(&options, host); 1323 exit(0); 1324 } 1325 1326 /* Expand SecurityKeyProvider if it refers to an environment variable */ 1327 if (options.sk_provider != NULL && *options.sk_provider == '$' && 1328 strlen(options.sk_provider) > 1) { 1329 if ((cp = getenv(options.sk_provider + 1)) == NULL) { 1330 debug("Security key provider %s did not resolve; " 1331 "disabling", options.sk_provider); 1332 free(options.sk_provider); 1333 options.sk_provider = NULL; 1334 } else { 1335 debug2("resolved SecurityKeyProvider %s => %s", 1336 options.sk_provider, cp); 1337 free(options.sk_provider); 1338 options.sk_provider = xstrdup(cp); 1339 } 1340 } 1341 1342 if (muxclient_command != 0 && options.control_path == NULL) 1343 fatal("No ControlPath specified for \"-O\" command"); 1344 if (options.control_path != NULL) { 1345 int sock; 1346 if ((sock = muxclient(options.control_path)) >= 0) { 1347 ssh_packet_set_connection(ssh, sock, sock); 1348 ssh_packet_set_mux(ssh); 1349 goto skip_connect; 1350 } 1351 } 1352 1353 /* 1354 * If hostname canonicalisation was not enabled, then we may not 1355 * have yet resolved the hostname. Do so now. 1356 */ 1357 if (addrs == NULL && options.proxy_command == NULL) { 1358 debug2("resolving \"%s\" port %d", host, options.port); 1359 if ((addrs = resolve_host(host, options.port, 1, 1360 cname, sizeof(cname))) == NULL) 1361 cleanup_exit(255); /* resolve_host logs the error */ 1362 } 1363 1364 timeout_ms = options.connection_timeout * 1000; 1365 1366 /* Open a connection to the remote host. */ 1367 if (ssh_connect(ssh, host_arg, host, addrs, &hostaddr, options.port, 1368 options.address_family, options.connection_attempts, 1369 &timeout_ms, options.tcp_keep_alive) != 0) 1370 exit(255); 1371 1372 if (addrs != NULL) 1373 freeaddrinfo(addrs); 1374 1375 ssh_packet_set_timeout(ssh, options.server_alive_interval, 1376 options.server_alive_count_max); 1377 1378 if (timeout_ms > 0) 1379 debug3("timeout: %d ms remain after connect", timeout_ms); 1380 1381 /* 1382 * If we successfully made the connection and we have hostbased auth 1383 * enabled, load the public keys so we can later use the ssh-keysign 1384 * helper to sign challenges. 1385 */ 1386 sensitive_data.nkeys = 0; 1387 sensitive_data.keys = NULL; 1388 if (options.hostbased_authentication) { 1389 sensitive_data.nkeys = 10; 1390 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 1391 sizeof(struct sshkey)); 1392 1393 /* XXX check errors? */ 1394 #define L_PUBKEY(p,o) do { \ 1395 if ((o) >= sensitive_data.nkeys) \ 1396 fatal("%s pubkey out of array bounds", __func__); \ 1397 check_load(sshkey_load_public(p, &(sensitive_data.keys[o]), NULL), \ 1398 p, "pubkey"); \ 1399 } while (0) 1400 #define L_CERT(p,o) do { \ 1401 if ((o) >= sensitive_data.nkeys) \ 1402 fatal("%s cert out of array bounds", __func__); \ 1403 check_load(sshkey_load_cert(p, &(sensitive_data.keys[o])), p, "cert"); \ 1404 } while (0) 1405 1406 if (options.hostbased_authentication == 1) { 1407 L_CERT(_PATH_HOST_ECDSA_KEY_FILE, 0); 1408 L_CERT(_PATH_HOST_ED25519_KEY_FILE, 1); 1409 L_CERT(_PATH_HOST_RSA_KEY_FILE, 2); 1410 L_CERT(_PATH_HOST_DSA_KEY_FILE, 3); 1411 L_PUBKEY(_PATH_HOST_ECDSA_KEY_FILE, 4); 1412 L_PUBKEY(_PATH_HOST_ED25519_KEY_FILE, 5); 1413 L_PUBKEY(_PATH_HOST_RSA_KEY_FILE, 6); 1414 L_PUBKEY(_PATH_HOST_DSA_KEY_FILE, 7); 1415 L_CERT(_PATH_HOST_XMSS_KEY_FILE, 8); 1416 L_PUBKEY(_PATH_HOST_XMSS_KEY_FILE, 9); 1417 } 1418 } 1419 1420 /* Create ~/.ssh * directory if it doesn't already exist. */ 1421 if (config == NULL) { 1422 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 1423 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 1424 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) == -1) 1425 if (mkdir(buf, 0700) == -1) 1426 error("Could not create directory '%.200s'.", 1427 buf); 1428 } 1429 1430 /* load options.identity_files */ 1431 load_public_identity_files(pw); 1432 1433 /* optionally set the SSH_AUTHSOCKET_ENV_NAME variable */ 1434 if (options.identity_agent && 1435 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) { 1436 if (strcmp(options.identity_agent, "none") == 0) { 1437 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1438 } else { 1439 p = tilde_expand_filename(options.identity_agent, 1440 getuid()); 1441 cp = percent_expand(p, 1442 "d", pw->pw_dir, 1443 "h", host, 1444 "i", uidstr, 1445 "l", thishost, 1446 "r", options.user, 1447 "u", pw->pw_name, 1448 (char *)NULL); 1449 free(p); 1450 /* 1451 * If identity_agent represents an environment variable 1452 * then recheck that it is valid (since processing with 1453 * percent_expand() may have changed it) and substitute 1454 * its value. 1455 */ 1456 if (cp[0] == '$') { 1457 if (!valid_env_name(cp + 1)) { 1458 fatal("Invalid IdentityAgent " 1459 "environment variable name %s", cp); 1460 } 1461 if ((p = getenv(cp + 1)) == NULL) 1462 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1463 else 1464 setenv(SSH_AUTHSOCKET_ENV_NAME, p, 1); 1465 } else { 1466 /* identity_agent specifies a path directly */ 1467 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1); 1468 } 1469 free(cp); 1470 } 1471 } 1472 1473 /* Expand ~ in known host file names. */ 1474 tilde_expand_paths(options.system_hostfiles, 1475 options.num_system_hostfiles); 1476 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 1477 1478 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 1479 signal(SIGCHLD, main_sigchld_handler); 1480 1481 /* Log into the remote system. Never returns if the login fails. */ 1482 ssh_login(ssh, &sensitive_data, host, (struct sockaddr *)&hostaddr, 1483 options.port, pw, timeout_ms); 1484 1485 if (ssh_packet_connection_is_on_socket(ssh)) { 1486 verbose("Authenticated to %s ([%s]:%d).", host, 1487 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); 1488 } else { 1489 verbose("Authenticated to %s (via proxy).", host); 1490 } 1491 1492 /* We no longer need the private host keys. Clear them now. */ 1493 if (sensitive_data.nkeys != 0) { 1494 for (i = 0; i < sensitive_data.nkeys; i++) { 1495 if (sensitive_data.keys[i] != NULL) { 1496 /* Destroys contents safely */ 1497 debug3("clear hostkey %d", i); 1498 sshkey_free(sensitive_data.keys[i]); 1499 sensitive_data.keys[i] = NULL; 1500 } 1501 } 1502 free(sensitive_data.keys); 1503 } 1504 for (i = 0; i < options.num_identity_files; i++) { 1505 free(options.identity_files[i]); 1506 options.identity_files[i] = NULL; 1507 if (options.identity_keys[i]) { 1508 sshkey_free(options.identity_keys[i]); 1509 options.identity_keys[i] = NULL; 1510 } 1511 } 1512 for (i = 0; i < options.num_certificate_files; i++) { 1513 free(options.certificate_files[i]); 1514 options.certificate_files[i] = NULL; 1515 } 1516 1517 skip_connect: 1518 exit_status = ssh_session2(ssh, pw); 1519 ssh_packet_close(ssh); 1520 1521 if (options.control_path != NULL && muxserver_sock != -1) 1522 unlink(options.control_path); 1523 1524 /* Kill ProxyCommand if it is running. */ 1525 ssh_kill_proxy_command(); 1526 1527 return exit_status; 1528 } 1529 1530 static void 1531 control_persist_detach(void) 1532 { 1533 pid_t pid; 1534 int devnull, keep_stderr; 1535 1536 debug("%s: backgrounding master process", __func__); 1537 1538 /* 1539 * master (current process) into the background, and make the 1540 * foreground process a client of the backgrounded master. 1541 */ 1542 switch ((pid = fork())) { 1543 case -1: 1544 fatal("%s: fork: %s", __func__, strerror(errno)); 1545 case 0: 1546 /* Child: master process continues mainloop */ 1547 break; 1548 default: 1549 /* Parent: set up mux slave to connect to backgrounded master */ 1550 debug2("%s: background process is %ld", __func__, (long)pid); 1551 stdin_null_flag = ostdin_null_flag; 1552 options.request_tty = orequest_tty; 1553 tty_flag = otty_flag; 1554 close(muxserver_sock); 1555 muxserver_sock = -1; 1556 options.control_master = SSHCTL_MASTER_NO; 1557 muxclient(options.control_path); 1558 /* muxclient() doesn't return on success. */ 1559 fatal("Failed to connect to new control master"); 1560 } 1561 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1562 error("%s: open(\"/dev/null\"): %s", __func__, 1563 strerror(errno)); 1564 } else { 1565 keep_stderr = log_is_on_stderr() && debug_flag; 1566 if (dup2(devnull, STDIN_FILENO) == -1 || 1567 dup2(devnull, STDOUT_FILENO) == -1 || 1568 (!keep_stderr && dup2(devnull, STDERR_FILENO) == -1)) 1569 error("%s: dup2: %s", __func__, strerror(errno)); 1570 if (devnull > STDERR_FILENO) 1571 close(devnull); 1572 } 1573 daemon(1, 1); 1574 setproctitle("%s [mux]", options.control_path); 1575 } 1576 1577 /* Do fork() after authentication. Used by "ssh -f" */ 1578 static void 1579 fork_postauth(void) 1580 { 1581 if (need_controlpersist_detach) 1582 control_persist_detach(); 1583 debug("forking to background"); 1584 fork_after_authentication_flag = 0; 1585 if (daemon(1, 1) == -1) 1586 fatal("daemon() failed: %.200s", strerror(errno)); 1587 } 1588 1589 /* Callback for remote forward global requests */ 1590 static void 1591 ssh_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt) 1592 { 1593 struct Forward *rfwd = (struct Forward *)ctxt; 1594 u_int port; 1595 int r; 1596 1597 /* XXX verbose() on failure? */ 1598 debug("remote forward %s for: listen %s%s%d, connect %s:%d", 1599 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1600 rfwd->listen_path ? rfwd->listen_path : 1601 rfwd->listen_host ? rfwd->listen_host : "", 1602 (rfwd->listen_path || rfwd->listen_host) ? ":" : "", 1603 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path : 1604 rfwd->connect_host, rfwd->connect_port); 1605 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) { 1606 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1607 if ((r = sshpkt_get_u32(ssh, &port)) != 0) 1608 fatal("%s: %s", __func__, ssh_err(r)); 1609 if (port > 65535) { 1610 error("Invalid allocated port %u for remote " 1611 "forward to %s:%d", port, 1612 rfwd->connect_host, rfwd->connect_port); 1613 /* Ensure failure processing runs below */ 1614 type = SSH2_MSG_REQUEST_FAILURE; 1615 channel_update_permission(ssh, 1616 rfwd->handle, -1); 1617 } else { 1618 rfwd->allocated_port = (int)port; 1619 logit("Allocated port %u for remote " 1620 "forward to %s:%d", 1621 rfwd->allocated_port, rfwd->connect_host, 1622 rfwd->connect_port); 1623 channel_update_permission(ssh, 1624 rfwd->handle, rfwd->allocated_port); 1625 } 1626 } else { 1627 channel_update_permission(ssh, rfwd->handle, -1); 1628 } 1629 } 1630 1631 if (type == SSH2_MSG_REQUEST_FAILURE) { 1632 if (options.exit_on_forward_failure) { 1633 if (rfwd->listen_path != NULL) 1634 fatal("Error: remote port forwarding failed " 1635 "for listen path %s", rfwd->listen_path); 1636 else 1637 fatal("Error: remote port forwarding failed " 1638 "for listen port %d", rfwd->listen_port); 1639 } else { 1640 if (rfwd->listen_path != NULL) 1641 logit("Warning: remote port forwarding failed " 1642 "for listen path %s", rfwd->listen_path); 1643 else 1644 logit("Warning: remote port forwarding failed " 1645 "for listen port %d", rfwd->listen_port); 1646 } 1647 } 1648 if (++remote_forward_confirms_received == options.num_remote_forwards) { 1649 debug("All remote forwarding requests processed"); 1650 if (fork_after_authentication_flag) 1651 fork_postauth(); 1652 } 1653 } 1654 1655 static void 1656 client_cleanup_stdio_fwd(struct ssh *ssh, int id, void *arg) 1657 { 1658 debug("stdio forwarding: done"); 1659 cleanup_exit(0); 1660 } 1661 1662 static void 1663 ssh_stdio_confirm(struct ssh *ssh, int id, int success, void *arg) 1664 { 1665 if (!success) 1666 fatal("stdio forwarding failed"); 1667 } 1668 1669 static void 1670 ssh_init_stdio_forwarding(struct ssh *ssh) 1671 { 1672 Channel *c; 1673 int in, out; 1674 1675 if (options.stdio_forward_host == NULL) 1676 return; 1677 1678 debug3("%s: %s:%d", __func__, options.stdio_forward_host, 1679 options.stdio_forward_port); 1680 1681 if ((in = dup(STDIN_FILENO)) == -1 || 1682 (out = dup(STDOUT_FILENO)) == -1) 1683 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1684 if ((c = channel_connect_stdio_fwd(ssh, options.stdio_forward_host, 1685 options.stdio_forward_port, in, out)) == NULL) 1686 fatal("%s: channel_connect_stdio_fwd failed", __func__); 1687 channel_register_cleanup(ssh, c->self, client_cleanup_stdio_fwd, 0); 1688 channel_register_open_confirm(ssh, c->self, ssh_stdio_confirm, NULL); 1689 } 1690 1691 static void 1692 ssh_init_forwarding(struct ssh *ssh, char **ifname) 1693 { 1694 int success = 0; 1695 int i; 1696 1697 /* Initiate local TCP/IP port forwardings. */ 1698 for (i = 0; i < options.num_local_forwards; i++) { 1699 debug("Local connections to %.200s:%d forwarded to remote " 1700 "address %.200s:%d", 1701 (options.local_forwards[i].listen_path != NULL) ? 1702 options.local_forwards[i].listen_path : 1703 (options.local_forwards[i].listen_host == NULL) ? 1704 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") : 1705 options.local_forwards[i].listen_host, 1706 options.local_forwards[i].listen_port, 1707 (options.local_forwards[i].connect_path != NULL) ? 1708 options.local_forwards[i].connect_path : 1709 options.local_forwards[i].connect_host, 1710 options.local_forwards[i].connect_port); 1711 success += channel_setup_local_fwd_listener(ssh, 1712 &options.local_forwards[i], &options.fwd_opts); 1713 } 1714 if (i > 0 && success != i && options.exit_on_forward_failure) 1715 fatal("Could not request local forwarding."); 1716 if (i > 0 && success == 0) 1717 error("Could not request local forwarding."); 1718 1719 /* Initiate remote TCP/IP port forwardings. */ 1720 for (i = 0; i < options.num_remote_forwards; i++) { 1721 debug("Remote connections from %.200s:%d forwarded to " 1722 "local address %.200s:%d", 1723 (options.remote_forwards[i].listen_path != NULL) ? 1724 options.remote_forwards[i].listen_path : 1725 (options.remote_forwards[i].listen_host == NULL) ? 1726 "LOCALHOST" : options.remote_forwards[i].listen_host, 1727 options.remote_forwards[i].listen_port, 1728 (options.remote_forwards[i].connect_path != NULL) ? 1729 options.remote_forwards[i].connect_path : 1730 options.remote_forwards[i].connect_host, 1731 options.remote_forwards[i].connect_port); 1732 options.remote_forwards[i].handle = 1733 channel_request_remote_forwarding(ssh, 1734 &options.remote_forwards[i]); 1735 if (options.remote_forwards[i].handle < 0) { 1736 if (options.exit_on_forward_failure) 1737 fatal("Could not request remote forwarding."); 1738 else 1739 logit("Warning: Could not request remote " 1740 "forwarding."); 1741 } else { 1742 client_register_global_confirm( 1743 ssh_confirm_remote_forward, 1744 &options.remote_forwards[i]); 1745 } 1746 } 1747 1748 /* Initiate tunnel forwarding. */ 1749 if (options.tun_open != SSH_TUNMODE_NO) { 1750 if ((*ifname = client_request_tun_fwd(ssh, 1751 options.tun_open, options.tun_local, 1752 options.tun_remote)) == NULL) { 1753 if (options.exit_on_forward_failure) 1754 fatal("Could not request tunnel forwarding."); 1755 else 1756 error("Could not request tunnel forwarding."); 1757 } 1758 } 1759 } 1760 1761 static void 1762 check_agent_present(void) 1763 { 1764 int r; 1765 1766 if (options.forward_agent) { 1767 /* Clear agent forwarding if we don't have an agent. */ 1768 if ((r = ssh_get_authentication_socket(NULL)) != 0) { 1769 options.forward_agent = 0; 1770 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1771 debug("ssh_get_authentication_socket: %s", 1772 ssh_err(r)); 1773 } 1774 } 1775 } 1776 1777 static void 1778 ssh_session2_setup(struct ssh *ssh, int id, int success, void *arg) 1779 { 1780 extern char **environ; 1781 const char *display; 1782 int r, interactive = tty_flag; 1783 char *proto = NULL, *data = NULL; 1784 1785 if (!success) 1786 return; /* No need for error message, channels code sens one */ 1787 1788 display = getenv("DISPLAY"); 1789 if (display == NULL && options.forward_x11) 1790 debug("X11 forwarding requested but DISPLAY not set"); 1791 if (options.forward_x11 && client_x11_get_proto(ssh, display, 1792 options.xauth_location, options.forward_x11_trusted, 1793 options.forward_x11_timeout, &proto, &data) == 0) { 1794 /* Request forwarding with authentication spoofing. */ 1795 debug("Requesting X11 forwarding with authentication " 1796 "spoofing."); 1797 x11_request_forwarding_with_spoofing(ssh, id, display, proto, 1798 data, 1); 1799 client_expect_confirm(ssh, id, "X11 forwarding", CONFIRM_WARN); 1800 /* XXX exit_on_forward_failure */ 1801 interactive = 1; 1802 } 1803 1804 check_agent_present(); 1805 if (options.forward_agent) { 1806 debug("Requesting authentication agent forwarding."); 1807 channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0); 1808 if ((r = sshpkt_send(ssh)) != 0) 1809 fatal("%s: %s", __func__, ssh_err(r)); 1810 } 1811 1812 /* Tell the packet module whether this is an interactive session. */ 1813 ssh_packet_set_interactive(ssh, interactive, 1814 options.ip_qos_interactive, options.ip_qos_bulk); 1815 1816 client_session2_setup(ssh, id, tty_flag, subsystem_flag, getenv("TERM"), 1817 NULL, fileno(stdin), command, environ); 1818 } 1819 1820 /* open new channel for a session */ 1821 static int 1822 ssh_session2_open(struct ssh *ssh) 1823 { 1824 Channel *c; 1825 int window, packetmax, in, out, err; 1826 1827 if (stdin_null_flag) { 1828 in = open(_PATH_DEVNULL, O_RDONLY); 1829 } else { 1830 in = dup(STDIN_FILENO); 1831 } 1832 out = dup(STDOUT_FILENO); 1833 err = dup(STDERR_FILENO); 1834 1835 if (in == -1 || out == -1 || err == -1) 1836 fatal("dup() in/out/err failed"); 1837 1838 /* enable nonblocking unless tty */ 1839 if (!isatty(in)) 1840 set_nonblock(in); 1841 if (!isatty(out)) 1842 set_nonblock(out); 1843 if (!isatty(err)) 1844 set_nonblock(err); 1845 1846 window = CHAN_SES_WINDOW_DEFAULT; 1847 packetmax = CHAN_SES_PACKET_DEFAULT; 1848 if (tty_flag) { 1849 window >>= 1; 1850 packetmax >>= 1; 1851 } 1852 c = channel_new(ssh, 1853 "session", SSH_CHANNEL_OPENING, in, out, err, 1854 window, packetmax, CHAN_EXTENDED_WRITE, 1855 "client-session", /*nonblock*/0); 1856 1857 debug3("%s: channel_new: %d", __func__, c->self); 1858 1859 channel_send_open(ssh, c->self); 1860 if (!no_shell_flag) 1861 channel_register_open_confirm(ssh, c->self, 1862 ssh_session2_setup, NULL); 1863 1864 return c->self; 1865 } 1866 1867 static int 1868 ssh_session2(struct ssh *ssh, struct passwd *pw) 1869 { 1870 int r, devnull, id = -1; 1871 char *cp, *tun_fwd_ifname = NULL; 1872 1873 /* XXX should be pre-session */ 1874 if (!options.control_persist) 1875 ssh_init_stdio_forwarding(ssh); 1876 1877 ssh_init_forwarding(ssh, &tun_fwd_ifname); 1878 1879 if (options.local_command != NULL) { 1880 debug3("expanding LocalCommand: %s", options.local_command); 1881 cp = options.local_command; 1882 options.local_command = percent_expand(cp, 1883 "C", conn_hash_hex, 1884 "L", shorthost, 1885 "d", pw->pw_dir, 1886 "h", host, 1887 "i", uidstr, 1888 "l", thishost, 1889 "n", host_arg, 1890 "p", portstr, 1891 "r", options.user, 1892 "u", pw->pw_name, 1893 "T", tun_fwd_ifname == NULL ? "NONE" : tun_fwd_ifname, 1894 (char *)NULL); 1895 debug3("expanded LocalCommand: %s", options.local_command); 1896 free(cp); 1897 } 1898 1899 /* Start listening for multiplex clients */ 1900 if (!ssh_packet_get_mux(ssh)) 1901 muxserver_listen(ssh); 1902 1903 /* 1904 * If we are in control persist mode and have a working mux listen 1905 * socket, then prepare to background ourselves and have a foreground 1906 * client attach as a control slave. 1907 * NB. we must save copies of the flags that we override for 1908 * the backgrounding, since we defer attachment of the slave until 1909 * after the connection is fully established (in particular, 1910 * async rfwd replies have been received for ExitOnForwardFailure). 1911 */ 1912 if (options.control_persist && muxserver_sock != -1) { 1913 ostdin_null_flag = stdin_null_flag; 1914 ono_shell_flag = no_shell_flag; 1915 orequest_tty = options.request_tty; 1916 otty_flag = tty_flag; 1917 stdin_null_flag = 1; 1918 no_shell_flag = 1; 1919 tty_flag = 0; 1920 if (!fork_after_authentication_flag) 1921 need_controlpersist_detach = 1; 1922 fork_after_authentication_flag = 1; 1923 } 1924 /* 1925 * ControlPersist mux listen socket setup failed, attempt the 1926 * stdio forward setup that we skipped earlier. 1927 */ 1928 if (options.control_persist && muxserver_sock == -1) 1929 ssh_init_stdio_forwarding(ssh); 1930 1931 if (!no_shell_flag) 1932 id = ssh_session2_open(ssh); 1933 else { 1934 ssh_packet_set_interactive(ssh, 1935 options.control_master == SSHCTL_MASTER_NO, 1936 options.ip_qos_interactive, options.ip_qos_bulk); 1937 } 1938 1939 /* If we don't expect to open a new session, then disallow it */ 1940 if (options.control_master == SSHCTL_MASTER_NO && 1941 (datafellows & SSH_NEW_OPENSSH)) { 1942 debug("Requesting no-more-sessions@openssh.com"); 1943 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 1944 (r = sshpkt_put_cstring(ssh, 1945 "no-more-sessions@openssh.com")) != 0 || 1946 (r = sshpkt_put_u8(ssh, 0)) != 0 || 1947 (r = sshpkt_send(ssh)) != 0) 1948 fatal("%s: %s", __func__, ssh_err(r)); 1949 } 1950 1951 /* Execute a local command */ 1952 if (options.local_command != NULL && 1953 options.permit_local_command) 1954 ssh_local_cmd(options.local_command); 1955 1956 /* 1957 * stdout is now owned by the session channel; clobber it here 1958 * so future channel closes are propagated to the local fd. 1959 * NB. this can only happen after LocalCommand has completed, 1960 * as it may want to write to stdout. 1961 */ 1962 if (!need_controlpersist_detach) { 1963 if ((devnull = open(_PATH_DEVNULL, O_WRONLY)) == -1) 1964 error("%s: open %s: %s", __func__, 1965 _PATH_DEVNULL, strerror(errno)); 1966 if (dup2(devnull, STDOUT_FILENO) == -1) 1967 fatal("%s: dup2() stdout failed", __func__); 1968 if (devnull > STDERR_FILENO) 1969 close(devnull); 1970 } 1971 1972 /* 1973 * If requested and we are not interested in replies to remote 1974 * forwarding requests, then let ssh continue in the background. 1975 */ 1976 if (fork_after_authentication_flag) { 1977 if (options.exit_on_forward_failure && 1978 options.num_remote_forwards > 0) { 1979 debug("deferring postauth fork until remote forward " 1980 "confirmation received"); 1981 } else 1982 fork_postauth(); 1983 } 1984 1985 return client_loop(ssh, tty_flag, tty_flag ? 1986 options.escape_char : SSH_ESCAPECHAR_NONE, id); 1987 } 1988 1989 /* Loads all IdentityFile and CertificateFile keys */ 1990 static void 1991 load_public_identity_files(struct passwd *pw) 1992 { 1993 char *filename, *cp; 1994 struct sshkey *public; 1995 int i; 1996 u_int n_ids, n_certs; 1997 char *identity_files[SSH_MAX_IDENTITY_FILES]; 1998 struct sshkey *identity_keys[SSH_MAX_IDENTITY_FILES]; 1999 int identity_file_userprovided[SSH_MAX_IDENTITY_FILES]; 2000 char *certificate_files[SSH_MAX_CERTIFICATE_FILES]; 2001 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES]; 2002 int certificate_file_userprovided[SSH_MAX_CERTIFICATE_FILES]; 2003 #ifdef ENABLE_PKCS11 2004 struct sshkey **keys; 2005 int nkeys; 2006 #endif /* PKCS11 */ 2007 2008 n_ids = n_certs = 0; 2009 memset(identity_files, 0, sizeof(identity_files)); 2010 memset(identity_keys, 0, sizeof(identity_keys)); 2011 memset(identity_file_userprovided, 0, 2012 sizeof(identity_file_userprovided)); 2013 memset(certificate_files, 0, sizeof(certificate_files)); 2014 memset(certificates, 0, sizeof(certificates)); 2015 memset(certificate_file_userprovided, 0, 2016 sizeof(certificate_file_userprovided)); 2017 2018 #ifdef ENABLE_PKCS11 2019 if (options.pkcs11_provider != NULL && 2020 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 2021 (pkcs11_init(!options.batch_mode) == 0) && 2022 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 2023 &keys)) > 0) { 2024 for (i = 0; i < nkeys; i++) { 2025 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 2026 sshkey_free(keys[i]); 2027 continue; 2028 } 2029 identity_keys[n_ids] = keys[i]; 2030 identity_files[n_ids] = 2031 xstrdup(options.pkcs11_provider); /* XXX */ 2032 n_ids++; 2033 } 2034 free(keys); 2035 } 2036 #endif /* ENABLE_PKCS11 */ 2037 for (i = 0; i < options.num_identity_files; i++) { 2038 if (n_ids >= SSH_MAX_IDENTITY_FILES || 2039 strcasecmp(options.identity_files[i], "none") == 0) { 2040 free(options.identity_files[i]); 2041 options.identity_files[i] = NULL; 2042 continue; 2043 } 2044 cp = tilde_expand_filename(options.identity_files[i], getuid()); 2045 filename = percent_expand(cp, "d", pw->pw_dir, 2046 "u", pw->pw_name, "l", thishost, "h", host, 2047 "r", options.user, (char *)NULL); 2048 free(cp); 2049 check_load(sshkey_load_public(filename, &public, NULL), 2050 filename, "pubkey"); 2051 debug("identity file %s type %d", filename, 2052 public ? public->type : -1); 2053 free(options.identity_files[i]); 2054 identity_files[n_ids] = filename; 2055 identity_keys[n_ids] = public; 2056 identity_file_userprovided[n_ids] = 2057 options.identity_file_userprovided[i]; 2058 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 2059 continue; 2060 2061 /* 2062 * If no certificates have been explicitly listed then try 2063 * to add the default certificate variant too. 2064 */ 2065 if (options.num_certificate_files != 0) 2066 continue; 2067 xasprintf(&cp, "%s-cert", filename); 2068 check_load(sshkey_load_public(cp, &public, NULL), 2069 filename, "pubkey"); 2070 debug("identity file %s type %d", cp, 2071 public ? public->type : -1); 2072 if (public == NULL) { 2073 free(cp); 2074 continue; 2075 } 2076 if (!sshkey_is_cert(public)) { 2077 debug("%s: key %s type %s is not a certificate", 2078 __func__, cp, sshkey_type(public)); 2079 sshkey_free(public); 2080 free(cp); 2081 continue; 2082 } 2083 /* NB. leave filename pointing to private key */ 2084 identity_files[n_ids] = xstrdup(filename); 2085 identity_keys[n_ids] = public; 2086 identity_file_userprovided[n_ids] = 2087 options.identity_file_userprovided[i]; 2088 n_ids++; 2089 } 2090 2091 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES) 2092 fatal("%s: too many certificates", __func__); 2093 for (i = 0; i < options.num_certificate_files; i++) { 2094 cp = tilde_expand_filename(options.certificate_files[i], 2095 getuid()); 2096 filename = percent_expand(cp, 2097 "d", pw->pw_dir, 2098 "h", host, 2099 "i", uidstr, 2100 "l", thishost, 2101 "r", options.user, 2102 "u", pw->pw_name, 2103 (char *)NULL); 2104 free(cp); 2105 2106 check_load(sshkey_load_public(filename, &public, NULL), 2107 filename, "certificate"); 2108 debug("certificate file %s type %d", filename, 2109 public ? public->type : -1); 2110 free(options.certificate_files[i]); 2111 options.certificate_files[i] = NULL; 2112 if (public == NULL) { 2113 free(filename); 2114 continue; 2115 } 2116 if (!sshkey_is_cert(public)) { 2117 debug("%s: key %s type %s is not a certificate", 2118 __func__, filename, sshkey_type(public)); 2119 sshkey_free(public); 2120 free(filename); 2121 continue; 2122 } 2123 certificate_files[n_certs] = filename; 2124 certificates[n_certs] = public; 2125 certificate_file_userprovided[n_certs] = 2126 options.certificate_file_userprovided[i]; 2127 ++n_certs; 2128 } 2129 2130 options.num_identity_files = n_ids; 2131 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 2132 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 2133 memcpy(options.identity_file_userprovided, 2134 identity_file_userprovided, sizeof(identity_file_userprovided)); 2135 2136 options.num_certificate_files = n_certs; 2137 memcpy(options.certificate_files, 2138 certificate_files, sizeof(certificate_files)); 2139 memcpy(options.certificates, certificates, sizeof(certificates)); 2140 memcpy(options.certificate_file_userprovided, 2141 certificate_file_userprovided, 2142 sizeof(certificate_file_userprovided)); 2143 } 2144 2145 static void 2146 main_sigchld_handler(int sig) 2147 { 2148 int save_errno = errno; 2149 pid_t pid; 2150 int status; 2151 2152 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 2153 (pid == -1 && errno == EINTR)) 2154 ; 2155 errno = save_errno; 2156 } 2157