1 /* $OpenBSD: ssh.c,v 1.520 2020/02/18 08:49:49 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 <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 <stdarg.h> 64 #include <unistd.h> 65 #include <limits.h> 66 #include <locale.h> 67 68 #ifdef WITH_OPENSSL 69 #include <openssl/evp.h> 70 #include <openssl/err.h> 71 #endif 72 73 #include "xmalloc.h" 74 #include "ssh.h" 75 #include "ssh2.h" 76 #include "canohost.h" 77 #include "compat.h" 78 #include "cipher.h" 79 #include "digest.h" 80 #include "packet.h" 81 #include "sshbuf.h" 82 #include "channels.h" 83 #include "sshkey.h" 84 #include "authfd.h" 85 #include "authfile.h" 86 #include "pathnames.h" 87 #include "dispatch.h" 88 #include "clientloop.h" 89 #include "log.h" 90 #include "misc.h" 91 #include "readconf.h" 92 #include "sshconnect.h" 93 #include "kex.h" 94 #include "mac.h" 95 #include "sshpty.h" 96 #include "match.h" 97 #include "msg.h" 98 #include "version.h" 99 #include "ssherr.h" 100 #include "myproposal.h" 101 102 #ifdef ENABLE_PKCS11 103 #include "ssh-pkcs11.h" 104 #endif 105 106 extern char *__progname; 107 108 /* Flag indicating whether debug mode is on. May be set on the command line. */ 109 int debug_flag = 0; 110 111 /* Flag indicating whether a tty should be requested */ 112 int tty_flag = 0; 113 114 /* don't exec a shell */ 115 int no_shell_flag = 0; 116 117 /* 118 * Flag indicating that nothing should be read from stdin. This can be set 119 * on the command line. 120 */ 121 int stdin_null_flag = 0; 122 123 /* 124 * Flag indicating that the current process should be backgrounded and 125 * a new slave launched in the foreground for ControlPersist. 126 */ 127 int need_controlpersist_detach = 0; 128 129 /* Copies of flags for ControlPersist foreground slave */ 130 int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty; 131 132 /* 133 * Flag indicating that ssh should fork after authentication. This is useful 134 * so that the passphrase can be entered manually, and then ssh goes to the 135 * background. 136 */ 137 int fork_after_authentication_flag = 0; 138 139 /* 140 * General data structure for command line options and options configurable 141 * in configuration files. See readconf.h. 142 */ 143 Options options; 144 145 /* optional user configfile */ 146 char *config = NULL; 147 148 /* 149 * Name of the host we are connecting to. This is the name given on the 150 * command line, or the Hostname specified for the user-supplied name in a 151 * configuration file. 152 */ 153 char *host; 154 155 /* 156 * A config can specify a path to forward, overriding SSH_AUTH_SOCK. If this is 157 * not NULL, forward the socket at this path instead. 158 */ 159 char *forward_agent_sock_path = NULL; 160 161 /* Various strings used to to percent_expand() arguments */ 162 static char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 163 static char uidstr[32], *host_arg, *conn_hash_hex; 164 165 /* socket address the host resolves to */ 166 struct sockaddr_storage hostaddr; 167 168 /* Private host keys. */ 169 Sensitive sensitive_data; 170 171 /* command to be executed */ 172 struct sshbuf *command; 173 174 /* Should we execute a command or invoke a subsystem? */ 175 int subsystem_flag = 0; 176 177 /* # of replies received for global requests */ 178 static int remote_forward_confirms_received = 0; 179 180 /* mux.c */ 181 extern int muxserver_sock; 182 extern u_int muxclient_command; 183 184 /* Prints a help message to the user. This function never returns. */ 185 186 static void 187 usage(void) 188 { 189 fprintf(stderr, 190 "usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]\n" 191 " [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]\n" 192 " [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]\n" 193 " [-i identity_file] [-J [user@]host[:port]] [-L address]\n" 194 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" 195 " [-Q query_option] [-R address] [-S ctl_path] [-W host:port]\n" 196 " [-w local_tun[:remote_tun]] destination [command]\n" 197 ); 198 exit(255); 199 } 200 201 static int ssh_session2(struct ssh *, struct passwd *); 202 static void load_public_identity_files(struct passwd *); 203 static void main_sigchld_handler(int); 204 205 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 206 static void 207 tilde_expand_paths(char **paths, u_int num_paths) 208 { 209 u_int i; 210 char *cp; 211 212 for (i = 0; i < num_paths; i++) { 213 cp = tilde_expand_filename(paths[i], getuid()); 214 free(paths[i]); 215 paths[i] = cp; 216 } 217 } 218 219 /* 220 * Attempt to resolve a host name / port to a set of addresses and 221 * optionally return any CNAMEs encountered along the way. 222 * Returns NULL on failure. 223 * NB. this function must operate with a options having undefined members. 224 */ 225 static struct addrinfo * 226 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen) 227 { 228 char strport[NI_MAXSERV]; 229 struct addrinfo hints, *res; 230 int gaierr; 231 LogLevel loglevel = SYSLOG_LEVEL_DEBUG1; 232 233 if (port <= 0) 234 port = default_ssh_port(); 235 236 snprintf(strport, sizeof strport, "%d", port); 237 memset(&hints, 0, sizeof(hints)); 238 hints.ai_family = options.address_family == -1 ? 239 AF_UNSPEC : options.address_family; 240 hints.ai_socktype = SOCK_STREAM; 241 if (cname != NULL) 242 hints.ai_flags = AI_CANONNAME; 243 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 244 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) 245 loglevel = SYSLOG_LEVEL_ERROR; 246 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", 247 __progname, name, ssh_gai_strerror(gaierr)); 248 return NULL; 249 } 250 if (cname != NULL && res->ai_canonname != NULL) { 251 if (strlcpy(cname, res->ai_canonname, clen) >= clen) { 252 error("%s: host \"%s\" cname \"%s\" too long (max %lu)", 253 __func__, name, res->ai_canonname, (u_long)clen); 254 if (clen > 0) 255 *cname = '\0'; 256 } 257 } 258 return res; 259 } 260 261 /* Returns non-zero if name can only be an address and not a hostname */ 262 static int 263 is_addr_fast(const char *name) 264 { 265 return (strchr(name, '%') != NULL || strchr(name, ':') != NULL || 266 strspn(name, "0123456789.") == strlen(name)); 267 } 268 269 /* Returns non-zero if name represents a valid, single address */ 270 static int 271 is_addr(const char *name) 272 { 273 char strport[NI_MAXSERV]; 274 struct addrinfo hints, *res; 275 276 if (is_addr_fast(name)) 277 return 1; 278 279 snprintf(strport, sizeof strport, "%u", default_ssh_port()); 280 memset(&hints, 0, sizeof(hints)); 281 hints.ai_family = options.address_family == -1 ? 282 AF_UNSPEC : options.address_family; 283 hints.ai_socktype = SOCK_STREAM; 284 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 285 if (getaddrinfo(name, strport, &hints, &res) != 0) 286 return 0; 287 if (res == NULL || res->ai_next != NULL) { 288 freeaddrinfo(res); 289 return 0; 290 } 291 freeaddrinfo(res); 292 return 1; 293 } 294 295 /* 296 * Attempt to resolve a numeric host address / port to a single address. 297 * Returns a canonical address string. 298 * Returns NULL on failure. 299 * NB. this function must operate with a options having undefined members. 300 */ 301 static struct addrinfo * 302 resolve_addr(const char *name, int port, char *caddr, size_t clen) 303 { 304 char addr[NI_MAXHOST], strport[NI_MAXSERV]; 305 struct addrinfo hints, *res; 306 int gaierr; 307 308 if (port <= 0) 309 port = default_ssh_port(); 310 snprintf(strport, sizeof strport, "%u", port); 311 memset(&hints, 0, sizeof(hints)); 312 hints.ai_family = options.address_family == -1 ? 313 AF_UNSPEC : options.address_family; 314 hints.ai_socktype = SOCK_STREAM; 315 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 316 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 317 debug2("%s: could not resolve name %.100s as address: %s", 318 __func__, name, ssh_gai_strerror(gaierr)); 319 return NULL; 320 } 321 if (res == NULL) { 322 debug("%s: getaddrinfo %.100s returned no addresses", 323 __func__, name); 324 return NULL; 325 } 326 if (res->ai_next != NULL) { 327 debug("%s: getaddrinfo %.100s returned multiple addresses", 328 __func__, name); 329 goto fail; 330 } 331 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen, 332 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) { 333 debug("%s: Could not format address for name %.100s: %s", 334 __func__, name, ssh_gai_strerror(gaierr)); 335 goto fail; 336 } 337 if (strlcpy(caddr, addr, clen) >= clen) { 338 error("%s: host \"%s\" addr \"%s\" too long (max %lu)", 339 __func__, name, addr, (u_long)clen); 340 if (clen > 0) 341 *caddr = '\0'; 342 fail: 343 freeaddrinfo(res); 344 return NULL; 345 } 346 return res; 347 } 348 349 /* 350 * Check whether the cname is a permitted replacement for the hostname 351 * and perform the replacement if it is. 352 * NB. this function must operate with a options having undefined members. 353 */ 354 static int 355 check_follow_cname(int direct, char **namep, const char *cname) 356 { 357 int i; 358 struct allowed_cname *rule; 359 360 if (*cname == '\0' || options.num_permitted_cnames == 0 || 361 strcmp(*namep, cname) == 0) 362 return 0; 363 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 364 return 0; 365 /* 366 * Don't attempt to canonicalize names that will be interpreted by 367 * a proxy or jump host unless the user specifically requests so. 368 */ 369 if (!direct && 370 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 371 return 0; 372 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname); 373 for (i = 0; i < options.num_permitted_cnames; i++) { 374 rule = options.permitted_cnames + i; 375 if (match_pattern_list(*namep, rule->source_list, 1) != 1 || 376 match_pattern_list(cname, rule->target_list, 1) != 1) 377 continue; 378 verbose("Canonicalized DNS aliased hostname " 379 "\"%s\" => \"%s\"", *namep, cname); 380 free(*namep); 381 *namep = xstrdup(cname); 382 return 1; 383 } 384 return 0; 385 } 386 387 /* 388 * Attempt to resolve the supplied hostname after applying the user's 389 * canonicalization rules. Returns the address list for the host or NULL 390 * if no name was found after canonicalization. 391 * NB. this function must operate with a options having undefined members. 392 */ 393 static struct addrinfo * 394 resolve_canonicalize(char **hostp, int port) 395 { 396 int i, direct, ndots; 397 char *cp, *fullhost, newname[NI_MAXHOST]; 398 struct addrinfo *addrs; 399 400 /* 401 * Attempt to canonicalise addresses, regardless of 402 * whether hostname canonicalisation was requested 403 */ 404 if ((addrs = resolve_addr(*hostp, port, 405 newname, sizeof(newname))) != NULL) { 406 debug2("%s: hostname %.100s is address", __func__, *hostp); 407 if (strcasecmp(*hostp, newname) != 0) { 408 debug2("%s: canonicalised address \"%s\" => \"%s\"", 409 __func__, *hostp, newname); 410 free(*hostp); 411 *hostp = xstrdup(newname); 412 } 413 return addrs; 414 } 415 416 /* 417 * If this looks like an address but didn't parse as one, it might 418 * be an address with an invalid interface scope. Skip further 419 * attempts at canonicalisation. 420 */ 421 if (is_addr_fast(*hostp)) { 422 debug("%s: hostname %.100s is an unrecognised address", 423 __func__, *hostp); 424 return NULL; 425 } 426 427 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 428 return NULL; 429 430 /* 431 * Don't attempt to canonicalize names that will be interpreted by 432 * a proxy unless the user specifically requests so. 433 */ 434 direct = option_clear_or_none(options.proxy_command) && 435 options.jump_host == NULL; 436 if (!direct && 437 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 438 return NULL; 439 440 /* If domain name is anchored, then resolve it now */ 441 if ((*hostp)[strlen(*hostp) - 1] == '.') { 442 debug3("%s: name is fully qualified", __func__); 443 fullhost = xstrdup(*hostp); 444 if ((addrs = resolve_host(fullhost, port, 0, 445 newname, sizeof(newname))) != NULL) 446 goto found; 447 free(fullhost); 448 goto notfound; 449 } 450 451 /* Don't apply canonicalization to sufficiently-qualified hostnames */ 452 ndots = 0; 453 for (cp = *hostp; *cp != '\0'; cp++) { 454 if (*cp == '.') 455 ndots++; 456 } 457 if (ndots > options.canonicalize_max_dots) { 458 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)", 459 __func__, *hostp, options.canonicalize_max_dots); 460 return NULL; 461 } 462 /* Attempt each supplied suffix */ 463 for (i = 0; i < options.num_canonical_domains; i++) { 464 *newname = '\0'; 465 xasprintf(&fullhost, "%s.%s.", *hostp, 466 options.canonical_domains[i]); 467 debug3("%s: attempting \"%s\" => \"%s\"", __func__, 468 *hostp, fullhost); 469 if ((addrs = resolve_host(fullhost, port, 0, 470 newname, sizeof(newname))) == NULL) { 471 free(fullhost); 472 continue; 473 } 474 found: 475 /* Remove trailing '.' */ 476 fullhost[strlen(fullhost) - 1] = '\0'; 477 /* Follow CNAME if requested */ 478 if (!check_follow_cname(direct, &fullhost, newname)) { 479 debug("Canonicalized hostname \"%s\" => \"%s\"", 480 *hostp, fullhost); 481 } 482 free(*hostp); 483 *hostp = fullhost; 484 return addrs; 485 } 486 notfound: 487 if (!options.canonicalize_fallback_local) 488 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); 489 debug2("%s: host %s not found in any suffix", __func__, *hostp); 490 return NULL; 491 } 492 493 /* 494 * Check the result of hostkey loading, ignoring some errors and 495 * fatal()ing for others. 496 */ 497 static void 498 check_load(int r, const char *path, const char *message) 499 { 500 switch (r) { 501 case 0: 502 break; 503 case SSH_ERR_INTERNAL_ERROR: 504 case SSH_ERR_ALLOC_FAIL: 505 fatal("load %s \"%s\": %s", message, path, ssh_err(r)); 506 case SSH_ERR_SYSTEM_ERROR: 507 /* Ignore missing files */ 508 if (errno == ENOENT) 509 break; 510 /* FALLTHROUGH */ 511 default: 512 error("load %s \"%s\": %s", message, path, ssh_err(r)); 513 break; 514 } 515 } 516 517 /* 518 * Read per-user configuration file. Ignore the system wide config 519 * file if the user specifies a config file on the command line. 520 */ 521 static void 522 process_config_files(const char *host_name, struct passwd *pw, int final_pass, 523 int *want_final_pass) 524 { 525 char buf[PATH_MAX]; 526 int r; 527 528 if (config != NULL) { 529 if (strcasecmp(config, "none") != 0 && 530 !read_config_file(config, pw, host, host_name, &options, 531 SSHCONF_USERCONF | (final_pass ? SSHCONF_FINAL : 0), 532 want_final_pass)) 533 fatal("Can't open user config file %.100s: " 534 "%.100s", config, strerror(errno)); 535 } else { 536 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 537 _PATH_SSH_USER_CONFFILE); 538 if (r > 0 && (size_t)r < sizeof(buf)) 539 (void)read_config_file(buf, pw, host, host_name, 540 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF | 541 (final_pass ? SSHCONF_FINAL : 0), want_final_pass); 542 543 /* Read systemwide configuration file after user config. */ 544 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, 545 host, host_name, &options, 546 final_pass ? SSHCONF_FINAL : 0, want_final_pass); 547 } 548 } 549 550 /* Rewrite the port number in an addrinfo list of addresses */ 551 static void 552 set_addrinfo_port(struct addrinfo *addrs, int port) 553 { 554 struct addrinfo *addr; 555 556 for (addr = addrs; addr != NULL; addr = addr->ai_next) { 557 switch (addr->ai_family) { 558 case AF_INET: 559 ((struct sockaddr_in *)addr->ai_addr)-> 560 sin_port = htons(port); 561 break; 562 case AF_INET6: 563 ((struct sockaddr_in6 *)addr->ai_addr)-> 564 sin6_port = htons(port); 565 break; 566 } 567 } 568 } 569 570 /* 571 * Main program for the ssh client. 572 */ 573 int 574 main(int ac, char **av) 575 { 576 struct ssh *ssh = NULL; 577 int i, r, opt, exit_status, use_syslog, direct, timeout_ms; 578 int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0; 579 char *p, *cp, *line, *argv0, buf[PATH_MAX], *logfile; 580 char cname[NI_MAXHOST]; 581 struct stat st; 582 struct passwd *pw; 583 extern int optind, optreset; 584 extern char *optarg; 585 struct Forward fwd; 586 struct addrinfo *addrs = NULL; 587 struct ssh_digest_ctx *md; 588 u_char conn_hash[SSH_DIGEST_MAX_LENGTH]; 589 size_t n, len; 590 591 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 592 sanitise_stdfd(); 593 594 /* 595 * Discard other fds that are hanging around. These can cause problem 596 * with backgrounded ssh processes started by ControlPersist. 597 */ 598 closefrom(STDERR_FILENO + 1); 599 600 if (getuid() != geteuid()) 601 fatal("ssh setuid not supported."); 602 if (getgid() != getegid()) 603 fatal("ssh setgid not supported."); 604 605 /* Get user data. */ 606 pw = getpwuid(getuid()); 607 if (!pw) { 608 logit("No user exists for uid %lu", (u_long)getuid()); 609 exit(255); 610 } 611 /* Take a copy of the returned structure. */ 612 pw = pwcopy(pw); 613 614 /* 615 * Set our umask to something reasonable, as some files are created 616 * with the default umask. This will make them world-readable but 617 * writable only by the owner, which is ok for all files for which we 618 * don't set the modes explicitly. 619 */ 620 umask(022); 621 622 setlocale(LC_CTYPE, ""); 623 624 /* 625 * Initialize option structure to indicate that no values have been 626 * set. 627 */ 628 initialize_options(&options); 629 630 /* 631 * Prepare main ssh transport/connection structures 632 */ 633 if ((ssh = ssh_alloc_session_state()) == NULL) 634 fatal("Couldn't allocate session state"); 635 channel_init_channels(ssh); 636 637 /* Parse command-line arguments. */ 638 host = NULL; 639 use_syslog = 0; 640 logfile = NULL; 641 argv0 = av[0]; 642 643 again: 644 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 645 "AB:CD:E:F:GI:J:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { 646 switch (opt) { 647 case '1': 648 fatal("SSH protocol v.1 is no longer supported"); 649 break; 650 case '2': 651 /* Ignored */ 652 break; 653 case '4': 654 options.address_family = AF_INET; 655 break; 656 case '6': 657 options.address_family = AF_INET6; 658 break; 659 case 'n': 660 stdin_null_flag = 1; 661 break; 662 case 'f': 663 fork_after_authentication_flag = 1; 664 stdin_null_flag = 1; 665 break; 666 case 'x': 667 options.forward_x11 = 0; 668 break; 669 case 'X': 670 options.forward_x11 = 1; 671 break; 672 case 'y': 673 use_syslog = 1; 674 break; 675 case 'E': 676 logfile = optarg; 677 break; 678 case 'G': 679 config_test = 1; 680 break; 681 case 'Y': 682 options.forward_x11 = 1; 683 options.forward_x11_trusted = 1; 684 break; 685 case 'g': 686 options.fwd_opts.gateway_ports = 1; 687 break; 688 case 'O': 689 if (options.stdio_forward_host != NULL) 690 fatal("Cannot specify multiplexing " 691 "command with -W"); 692 else if (muxclient_command != 0) 693 fatal("Multiplexing command already specified"); 694 if (strcmp(optarg, "check") == 0) 695 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 696 else if (strcmp(optarg, "forward") == 0) 697 muxclient_command = SSHMUX_COMMAND_FORWARD; 698 else if (strcmp(optarg, "exit") == 0) 699 muxclient_command = SSHMUX_COMMAND_TERMINATE; 700 else if (strcmp(optarg, "stop") == 0) 701 muxclient_command = SSHMUX_COMMAND_STOP; 702 else if (strcmp(optarg, "cancel") == 0) 703 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 704 else if (strcmp(optarg, "proxy") == 0) 705 muxclient_command = SSHMUX_COMMAND_PROXY; 706 else 707 fatal("Invalid multiplex command."); 708 break; 709 case 'P': /* deprecated */ 710 break; 711 case 'Q': 712 cp = NULL; 713 if (strcmp(optarg, "cipher") == 0 || 714 strcasecmp(optarg, "Ciphers") == 0) 715 cp = cipher_alg_list('\n', 0); 716 else if (strcmp(optarg, "cipher-auth") == 0) 717 cp = cipher_alg_list('\n', 1); 718 else if (strcmp(optarg, "mac") == 0 || 719 strcasecmp(optarg, "MACs") == 0) 720 cp = mac_alg_list('\n'); 721 else if (strcmp(optarg, "kex") == 0 || 722 strcasecmp(optarg, "KexAlgorithms") == 0) 723 cp = kex_alg_list('\n'); 724 else if (strcmp(optarg, "key") == 0) 725 cp = sshkey_alg_list(0, 0, 0, '\n'); 726 else if (strcmp(optarg, "key-cert") == 0) 727 cp = sshkey_alg_list(1, 0, 0, '\n'); 728 else if (strcmp(optarg, "key-plain") == 0) 729 cp = sshkey_alg_list(0, 1, 0, '\n'); 730 else if (strcmp(optarg, "key-sig") == 0 || 731 strcasecmp(optarg, "PubkeyAcceptedKeyTypes") == 0 || 732 strcasecmp(optarg, "HostKeyAlgorithms") == 0 || 733 strcasecmp(optarg, "HostbasedKeyTypes") == 0 || 734 strcasecmp(optarg, "HostbasedAcceptedKeyTypes") == 0) 735 cp = sshkey_alg_list(0, 0, 1, '\n'); 736 else if (strcmp(optarg, "sig") == 0) 737 cp = sshkey_alg_list(0, 1, 1, '\n'); 738 else if (strcmp(optarg, "protocol-version") == 0) 739 cp = xstrdup("2"); 740 else if (strcmp(optarg, "compression") == 0) { 741 cp = xstrdup(compression_alg_list(0)); 742 len = strlen(cp); 743 for (n = 0; n < len; n++) 744 if (cp[n] == ',') 745 cp[n] = '\n'; 746 } else if (strcmp(optarg, "help") == 0) { 747 cp = xstrdup( 748 "cipher\ncipher-auth\ncompression\nkex\n" 749 "key\nkey-cert\nkey-plain\nkey-sig\nmac\n" 750 "protocol-version\nsig"); 751 } 752 if (cp == NULL) 753 fatal("Unsupported query \"%s\"", optarg); 754 printf("%s\n", cp); 755 free(cp); 756 exit(0); 757 break; 758 case 'a': 759 options.forward_agent = 0; 760 break; 761 case 'A': 762 options.forward_agent = 1; 763 break; 764 case 'k': 765 options.gss_deleg_creds = 0; 766 break; 767 case 'K': 768 options.gss_authentication = 1; 769 options.gss_deleg_creds = 1; 770 break; 771 case 'i': 772 p = tilde_expand_filename(optarg, getuid()); 773 if (stat(p, &st) == -1) 774 fprintf(stderr, "Warning: Identity file %s " 775 "not accessible: %s.\n", p, 776 strerror(errno)); 777 else 778 add_identity_file(&options, NULL, p, 1); 779 free(p); 780 break; 781 case 'I': 782 #ifdef ENABLE_PKCS11 783 free(options.pkcs11_provider); 784 options.pkcs11_provider = xstrdup(optarg); 785 #else 786 fprintf(stderr, "no support for PKCS#11.\n"); 787 #endif 788 break; 789 case 'J': 790 if (options.jump_host != NULL) { 791 fatal("Only a single -J option is permitted " 792 "(use commas to separate multiple " 793 "jump hops)"); 794 } 795 if (options.proxy_command != NULL) 796 fatal("Cannot specify -J with ProxyCommand"); 797 if (parse_jump(optarg, &options, 1) == -1) 798 fatal("Invalid -J argument"); 799 options.proxy_command = xstrdup("none"); 800 break; 801 case 't': 802 if (options.request_tty == REQUEST_TTY_YES) 803 options.request_tty = REQUEST_TTY_FORCE; 804 else 805 options.request_tty = REQUEST_TTY_YES; 806 break; 807 case 'v': 808 if (debug_flag == 0) { 809 debug_flag = 1; 810 options.log_level = SYSLOG_LEVEL_DEBUG1; 811 } else { 812 if (options.log_level < SYSLOG_LEVEL_DEBUG3) { 813 debug_flag++; 814 options.log_level++; 815 } 816 } 817 break; 818 case 'V': 819 fprintf(stderr, "%s, %s\n", 820 SSH_VERSION, 821 #ifdef WITH_OPENSSL 822 OpenSSL_version(OPENSSL_VERSION) 823 #else 824 "without OpenSSL" 825 #endif 826 ); 827 if (opt == 'V') 828 exit(0); 829 break; 830 case 'w': 831 if (options.tun_open == -1) 832 options.tun_open = SSH_TUNMODE_DEFAULT; 833 options.tun_local = a2tun(optarg, &options.tun_remote); 834 if (options.tun_local == SSH_TUNID_ERR) { 835 fprintf(stderr, 836 "Bad tun device '%s'\n", optarg); 837 exit(255); 838 } 839 break; 840 case 'W': 841 if (options.stdio_forward_host != NULL) 842 fatal("stdio forward already specified"); 843 if (muxclient_command != 0) 844 fatal("Cannot specify stdio forward with -O"); 845 if (parse_forward(&fwd, optarg, 1, 0)) { 846 options.stdio_forward_host = fwd.listen_host; 847 options.stdio_forward_port = fwd.listen_port; 848 free(fwd.connect_host); 849 } else { 850 fprintf(stderr, 851 "Bad stdio forwarding specification '%s'\n", 852 optarg); 853 exit(255); 854 } 855 options.request_tty = REQUEST_TTY_NO; 856 no_shell_flag = 1; 857 break; 858 case 'q': 859 options.log_level = SYSLOG_LEVEL_QUIET; 860 break; 861 case 'e': 862 if (optarg[0] == '^' && optarg[2] == 0 && 863 (u_char) optarg[1] >= 64 && 864 (u_char) optarg[1] < 128) 865 options.escape_char = (u_char) optarg[1] & 31; 866 else if (strlen(optarg) == 1) 867 options.escape_char = (u_char) optarg[0]; 868 else if (strcmp(optarg, "none") == 0) 869 options.escape_char = SSH_ESCAPECHAR_NONE; 870 else { 871 fprintf(stderr, "Bad escape character '%s'.\n", 872 optarg); 873 exit(255); 874 } 875 break; 876 case 'c': 877 if (!ciphers_valid(*optarg == '+' || *optarg == '^' ? 878 optarg + 1 : optarg)) { 879 fprintf(stderr, "Unknown cipher type '%s'\n", 880 optarg); 881 exit(255); 882 } 883 free(options.ciphers); 884 options.ciphers = xstrdup(optarg); 885 break; 886 case 'm': 887 if (mac_valid(optarg)) { 888 free(options.macs); 889 options.macs = xstrdup(optarg); 890 } else { 891 fprintf(stderr, "Unknown mac type '%s'\n", 892 optarg); 893 exit(255); 894 } 895 break; 896 case 'M': 897 if (options.control_master == SSHCTL_MASTER_YES) 898 options.control_master = SSHCTL_MASTER_ASK; 899 else 900 options.control_master = SSHCTL_MASTER_YES; 901 break; 902 case 'p': 903 if (options.port == -1) { 904 options.port = a2port(optarg); 905 if (options.port <= 0) { 906 fprintf(stderr, "Bad port '%s'\n", 907 optarg); 908 exit(255); 909 } 910 } 911 break; 912 case 'l': 913 if (options.user == NULL) 914 options.user = optarg; 915 break; 916 917 case 'L': 918 if (parse_forward(&fwd, optarg, 0, 0)) 919 add_local_forward(&options, &fwd); 920 else { 921 fprintf(stderr, 922 "Bad local forwarding specification '%s'\n", 923 optarg); 924 exit(255); 925 } 926 break; 927 928 case 'R': 929 if (parse_forward(&fwd, optarg, 0, 1) || 930 parse_forward(&fwd, optarg, 1, 1)) { 931 add_remote_forward(&options, &fwd); 932 } else { 933 fprintf(stderr, 934 "Bad remote forwarding specification " 935 "'%s'\n", optarg); 936 exit(255); 937 } 938 break; 939 940 case 'D': 941 if (parse_forward(&fwd, optarg, 1, 0)) { 942 add_local_forward(&options, &fwd); 943 } else { 944 fprintf(stderr, 945 "Bad dynamic forwarding specification " 946 "'%s'\n", optarg); 947 exit(255); 948 } 949 break; 950 951 case 'C': 952 #ifdef WITH_ZLIB 953 options.compression = 1; 954 #else 955 error("Compression not supported, disabling."); 956 #endif 957 break; 958 case 'N': 959 no_shell_flag = 1; 960 options.request_tty = REQUEST_TTY_NO; 961 break; 962 case 'T': 963 options.request_tty = REQUEST_TTY_NO; 964 break; 965 case 'o': 966 line = xstrdup(optarg); 967 if (process_config_line(&options, pw, 968 host ? host : "", host ? host : "", line, 969 "command-line", 0, NULL, SSHCONF_USERCONF) != 0) 970 exit(255); 971 free(line); 972 break; 973 case 's': 974 subsystem_flag = 1; 975 break; 976 case 'S': 977 free(options.control_path); 978 options.control_path = xstrdup(optarg); 979 break; 980 case 'b': 981 options.bind_address = optarg; 982 break; 983 case 'B': 984 options.bind_interface = optarg; 985 break; 986 case 'F': 987 config = optarg; 988 break; 989 default: 990 usage(); 991 } 992 } 993 994 if (optind > 1 && strcmp(av[optind - 1], "--") == 0) 995 opt_terminated = 1; 996 997 ac -= optind; 998 av += optind; 999 1000 if (ac > 0 && !host) { 1001 int tport; 1002 char *tuser; 1003 switch (parse_ssh_uri(*av, &tuser, &host, &tport)) { 1004 case -1: 1005 usage(); 1006 break; 1007 case 0: 1008 if (options.user == NULL) { 1009 options.user = tuser; 1010 tuser = NULL; 1011 } 1012 free(tuser); 1013 if (options.port == -1 && tport != -1) 1014 options.port = tport; 1015 break; 1016 default: 1017 p = xstrdup(*av); 1018 cp = strrchr(p, '@'); 1019 if (cp != NULL) { 1020 if (cp == p) 1021 usage(); 1022 if (options.user == NULL) { 1023 options.user = p; 1024 p = NULL; 1025 } 1026 *cp++ = '\0'; 1027 host = xstrdup(cp); 1028 free(p); 1029 } else 1030 host = p; 1031 break; 1032 } 1033 if (ac > 1 && !opt_terminated) { 1034 optind = optreset = 1; 1035 goto again; 1036 } 1037 ac--, av++; 1038 } 1039 1040 /* Check that we got a host name. */ 1041 if (!host) 1042 usage(); 1043 1044 host_arg = xstrdup(host); 1045 1046 #ifdef WITH_OPENSSL 1047 OpenSSL_add_all_algorithms(); 1048 ERR_load_crypto_strings(); 1049 #endif 1050 1051 /* Initialize the command to execute on remote host. */ 1052 if ((command = sshbuf_new()) == NULL) 1053 fatal("sshbuf_new failed"); 1054 1055 /* 1056 * Save the command to execute on the remote host in a buffer. There 1057 * is no limit on the length of the command, except by the maximum 1058 * packet size. Also sets the tty flag if there is no command. 1059 */ 1060 if (!ac) { 1061 /* No command specified - execute shell on a tty. */ 1062 if (subsystem_flag) { 1063 fprintf(stderr, 1064 "You must specify a subsystem to invoke.\n"); 1065 usage(); 1066 } 1067 } else { 1068 /* A command has been specified. Store it into the buffer. */ 1069 for (i = 0; i < ac; i++) { 1070 if ((r = sshbuf_putf(command, "%s%s", 1071 i ? " " : "", av[i])) != 0) 1072 fatal("%s: buffer error: %s", 1073 __func__, ssh_err(r)); 1074 } 1075 } 1076 1077 /* 1078 * Initialize "log" output. Since we are the client all output 1079 * goes to stderr unless otherwise specified by -y or -E. 1080 */ 1081 if (use_syslog && logfile != NULL) 1082 fatal("Can't specify both -y and -E"); 1083 if (logfile != NULL) 1084 log_redirect_stderr_to(logfile); 1085 log_init(argv0, 1086 options.log_level == SYSLOG_LEVEL_NOT_SET ? 1087 SYSLOG_LEVEL_INFO : options.log_level, 1088 options.log_facility == SYSLOG_FACILITY_NOT_SET ? 1089 SYSLOG_FACILITY_USER : options.log_facility, 1090 !use_syslog); 1091 1092 if (debug_flag) 1093 logit("%s, %s", SSH_VERSION, 1094 #ifdef WITH_OPENSSL 1095 OpenSSL_version(OPENSSL_VERSION) 1096 #else 1097 "without OpenSSL" 1098 #endif 1099 ); 1100 1101 /* Parse the configuration files */ 1102 process_config_files(host_arg, pw, 0, &want_final_pass); 1103 if (want_final_pass) 1104 debug("configuration requests final Match pass"); 1105 1106 /* Hostname canonicalisation needs a few options filled. */ 1107 fill_default_options_for_canonicalization(&options); 1108 1109 /* If the user has replaced the hostname then take it into use now */ 1110 if (options.hostname != NULL) { 1111 /* NB. Please keep in sync with readconf.c:match_cfg_line() */ 1112 cp = percent_expand(options.hostname, 1113 "h", host, (char *)NULL); 1114 free(host); 1115 host = cp; 1116 free(options.hostname); 1117 options.hostname = xstrdup(host); 1118 } 1119 1120 /* Don't lowercase addresses, they will be explicitly canonicalised */ 1121 if ((was_addr = is_addr(host)) == 0) 1122 lowercase(host); 1123 1124 /* 1125 * Try to canonicalize if requested by configuration or the 1126 * hostname is an address. 1127 */ 1128 if (options.canonicalize_hostname != SSH_CANONICALISE_NO || was_addr) 1129 addrs = resolve_canonicalize(&host, options.port); 1130 1131 /* 1132 * If CanonicalizePermittedCNAMEs have been specified but 1133 * other canonicalization did not happen (by not being requested 1134 * or by failing with fallback) then the hostname may still be changed 1135 * as a result of CNAME following. 1136 * 1137 * Try to resolve the bare hostname name using the system resolver's 1138 * usual search rules and then apply the CNAME follow rules. 1139 * 1140 * Skip the lookup if a ProxyCommand is being used unless the user 1141 * has specifically requested canonicalisation for this case via 1142 * CanonicalizeHostname=always 1143 */ 1144 direct = option_clear_or_none(options.proxy_command) && 1145 options.jump_host == NULL; 1146 if (addrs == NULL && options.num_permitted_cnames != 0 && (direct || 1147 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { 1148 if ((addrs = resolve_host(host, options.port, 1149 direct, cname, sizeof(cname))) == NULL) { 1150 /* Don't fatal proxied host names not in the DNS */ 1151 if (direct) 1152 cleanup_exit(255); /* logged in resolve_host */ 1153 } else 1154 check_follow_cname(direct, &host, cname); 1155 } 1156 1157 /* 1158 * If canonicalisation is enabled then re-parse the configuration 1159 * files as new stanzas may match. 1160 */ 1161 if (options.canonicalize_hostname != 0 && !want_final_pass) { 1162 debug("hostname canonicalisation enabled, " 1163 "will re-parse configuration"); 1164 want_final_pass = 1; 1165 } 1166 1167 if (want_final_pass) { 1168 debug("re-parsing configuration"); 1169 free(options.hostname); 1170 options.hostname = xstrdup(host); 1171 process_config_files(host_arg, pw, 1, NULL); 1172 /* 1173 * Address resolution happens early with canonicalisation 1174 * enabled and the port number may have changed since, so 1175 * reset it in address list 1176 */ 1177 if (addrs != NULL && options.port > 0) 1178 set_addrinfo_port(addrs, options.port); 1179 } 1180 1181 /* Fill configuration defaults. */ 1182 fill_default_options(&options); 1183 1184 /* 1185 * If ProxyJump option specified, then construct a ProxyCommand now. 1186 */ 1187 if (options.jump_host != NULL) { 1188 char port_s[8]; 1189 const char *sshbin = argv0; 1190 int port = options.port, jumpport = options.jump_port; 1191 1192 if (port <= 0) 1193 port = default_ssh_port(); 1194 if (jumpport <= 0) 1195 jumpport = default_ssh_port(); 1196 if (strcmp(options.jump_host, host) == 0 && port == jumpport) 1197 fatal("jumphost loop via %s", options.jump_host); 1198 1199 /* 1200 * Try to use SSH indicated by argv[0], but fall back to 1201 * "ssh" if it appears unavailable. 1202 */ 1203 if (strchr(argv0, '/') != NULL && access(argv0, X_OK) != 0) 1204 sshbin = "ssh"; 1205 1206 /* Consistency check */ 1207 if (options.proxy_command != NULL) 1208 fatal("inconsistent options: ProxyCommand+ProxyJump"); 1209 /* Never use FD passing for ProxyJump */ 1210 options.proxy_use_fdpass = 0; 1211 snprintf(port_s, sizeof(port_s), "%d", options.jump_port); 1212 xasprintf(&options.proxy_command, 1213 "%s%s%s%s%s%s%s%s%s%s%.*s -W '[%%h]:%%p' %s", 1214 sshbin, 1215 /* Optional "-l user" argument if jump_user set */ 1216 options.jump_user == NULL ? "" : " -l ", 1217 options.jump_user == NULL ? "" : options.jump_user, 1218 /* Optional "-p port" argument if jump_port set */ 1219 options.jump_port <= 0 ? "" : " -p ", 1220 options.jump_port <= 0 ? "" : port_s, 1221 /* Optional additional jump hosts ",..." */ 1222 options.jump_extra == NULL ? "" : " -J ", 1223 options.jump_extra == NULL ? "" : options.jump_extra, 1224 /* Optional "-F" argumment if -F specified */ 1225 config == NULL ? "" : " -F ", 1226 config == NULL ? "" : config, 1227 /* Optional "-v" arguments if -v set */ 1228 debug_flag ? " -" : "", 1229 debug_flag, "vvv", 1230 /* Mandatory hostname */ 1231 options.jump_host); 1232 debug("Setting implicit ProxyCommand from ProxyJump: %s", 1233 options.proxy_command); 1234 } 1235 1236 if (options.port == 0) 1237 options.port = default_ssh_port(); 1238 channel_set_af(ssh, options.address_family); 1239 1240 /* Tidy and check options */ 1241 if (options.host_key_alias != NULL) 1242 lowercase(options.host_key_alias); 1243 if (options.proxy_command != NULL && 1244 strcmp(options.proxy_command, "-") == 0 && 1245 options.proxy_use_fdpass) 1246 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); 1247 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 1248 if (options.control_persist && options.control_path != NULL) { 1249 debug("UpdateHostKeys=ask is incompatible with " 1250 "ControlPersist; disabling"); 1251 options.update_hostkeys = 0; 1252 } else if (sshbuf_len(command) != 0 || 1253 options.remote_command != NULL || 1254 options.request_tty == REQUEST_TTY_NO) { 1255 debug("UpdateHostKeys=ask is incompatible with " 1256 "remote command execution; disabling"); 1257 options.update_hostkeys = 0; 1258 } else if (options.log_level < SYSLOG_LEVEL_INFO) { 1259 /* no point logging anything; user won't see it */ 1260 options.update_hostkeys = 0; 1261 } 1262 } 1263 if (options.connection_attempts <= 0) 1264 fatal("Invalid number of ConnectionAttempts"); 1265 1266 if (sshbuf_len(command) != 0 && options.remote_command != NULL) 1267 fatal("Cannot execute command-line and remote command."); 1268 1269 /* Cannot fork to background if no command. */ 1270 if (fork_after_authentication_flag && sshbuf_len(command) == 0 && 1271 options.remote_command == NULL && !no_shell_flag) 1272 fatal("Cannot fork into background without a command " 1273 "to execute."); 1274 1275 /* reinit */ 1276 log_init(argv0, options.log_level, options.log_facility, !use_syslog); 1277 1278 if (options.request_tty == REQUEST_TTY_YES || 1279 options.request_tty == REQUEST_TTY_FORCE) 1280 tty_flag = 1; 1281 1282 /* Allocate a tty by default if no command specified. */ 1283 if (sshbuf_len(command) == 0 && options.remote_command == NULL) 1284 tty_flag = options.request_tty != REQUEST_TTY_NO; 1285 1286 /* Force no tty */ 1287 if (options.request_tty == REQUEST_TTY_NO || 1288 (muxclient_command && muxclient_command != SSHMUX_COMMAND_PROXY)) 1289 tty_flag = 0; 1290 /* Do not allocate a tty if stdin is not a tty. */ 1291 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 1292 options.request_tty != REQUEST_TTY_FORCE) { 1293 if (tty_flag) 1294 logit("Pseudo-terminal will not be allocated because " 1295 "stdin is not a terminal."); 1296 tty_flag = 0; 1297 } 1298 1299 if (options.user == NULL) 1300 options.user = xstrdup(pw->pw_name); 1301 1302 /* Set up strings used to percent_expand() arguments */ 1303 if (gethostname(thishost, sizeof(thishost)) == -1) 1304 fatal("gethostname: %s", strerror(errno)); 1305 strlcpy(shorthost, thishost, sizeof(shorthost)); 1306 shorthost[strcspn(thishost, ".")] = '\0'; 1307 snprintf(portstr, sizeof(portstr), "%d", options.port); 1308 snprintf(uidstr, sizeof(uidstr), "%llu", 1309 (unsigned long long)pw->pw_uid); 1310 1311 if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL || 1312 ssh_digest_update(md, thishost, strlen(thishost)) < 0 || 1313 ssh_digest_update(md, host, strlen(host)) < 0 || 1314 ssh_digest_update(md, portstr, strlen(portstr)) < 0 || 1315 ssh_digest_update(md, options.user, strlen(options.user)) < 0 || 1316 ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0) 1317 fatal("%s: mux digest failed", __func__); 1318 ssh_digest_free(md); 1319 conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1)); 1320 1321 /* 1322 * Expand tokens in arguments. NB. LocalCommand is expanded later, 1323 * after port-forwarding is set up, so it may pick up any local 1324 * tunnel interface name allocated. 1325 */ 1326 if (options.remote_command != NULL) { 1327 debug3("expanding RemoteCommand: %s", options.remote_command); 1328 cp = options.remote_command; 1329 options.remote_command = percent_expand(cp, 1330 "C", conn_hash_hex, 1331 "L", shorthost, 1332 "d", pw->pw_dir, 1333 "h", host, 1334 "i", uidstr, 1335 "l", thishost, 1336 "n", host_arg, 1337 "p", portstr, 1338 "r", options.user, 1339 "u", pw->pw_name, 1340 (char *)NULL); 1341 debug3("expanded RemoteCommand: %s", options.remote_command); 1342 free(cp); 1343 if ((r = sshbuf_put(command, options.remote_command, 1344 strlen(options.remote_command))) != 0) 1345 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1346 } 1347 1348 if (options.control_path != NULL) { 1349 cp = tilde_expand_filename(options.control_path, getuid()); 1350 free(options.control_path); 1351 options.control_path = percent_expand(cp, 1352 "C", conn_hash_hex, 1353 "L", shorthost, 1354 "h", host, 1355 "i", uidstr, 1356 "l", thishost, 1357 "n", host_arg, 1358 "p", portstr, 1359 "r", options.user, 1360 "u", pw->pw_name, 1361 "i", uidstr, 1362 (char *)NULL); 1363 free(cp); 1364 } 1365 1366 if (config_test) { 1367 dump_client_config(&options, host); 1368 exit(0); 1369 } 1370 1371 /* Expand SecurityKeyProvider if it refers to an environment variable */ 1372 if (options.sk_provider != NULL && *options.sk_provider == '$' && 1373 strlen(options.sk_provider) > 1) { 1374 if ((cp = getenv(options.sk_provider + 1)) == NULL) { 1375 debug("Authenticator provider %s did not resolve; " 1376 "disabling", options.sk_provider); 1377 free(options.sk_provider); 1378 options.sk_provider = NULL; 1379 } else { 1380 debug2("resolved SecurityKeyProvider %s => %s", 1381 options.sk_provider, cp); 1382 free(options.sk_provider); 1383 options.sk_provider = xstrdup(cp); 1384 } 1385 } 1386 1387 if (muxclient_command != 0 && options.control_path == NULL) 1388 fatal("No ControlPath specified for \"-O\" command"); 1389 if (options.control_path != NULL) { 1390 int sock; 1391 if ((sock = muxclient(options.control_path)) >= 0) { 1392 ssh_packet_set_connection(ssh, sock, sock); 1393 ssh_packet_set_mux(ssh); 1394 goto skip_connect; 1395 } 1396 } 1397 1398 /* 1399 * If hostname canonicalisation was not enabled, then we may not 1400 * have yet resolved the hostname. Do so now. 1401 */ 1402 if (addrs == NULL && options.proxy_command == NULL) { 1403 debug2("resolving \"%s\" port %d", host, options.port); 1404 if ((addrs = resolve_host(host, options.port, 1, 1405 cname, sizeof(cname))) == NULL) 1406 cleanup_exit(255); /* resolve_host logs the error */ 1407 } 1408 1409 timeout_ms = options.connection_timeout * 1000; 1410 1411 /* Open a connection to the remote host. */ 1412 if (ssh_connect(ssh, host, host_arg, addrs, &hostaddr, options.port, 1413 options.address_family, options.connection_attempts, 1414 &timeout_ms, options.tcp_keep_alive) != 0) 1415 exit(255); 1416 1417 if (addrs != NULL) 1418 freeaddrinfo(addrs); 1419 1420 ssh_packet_set_timeout(ssh, options.server_alive_interval, 1421 options.server_alive_count_max); 1422 1423 if (timeout_ms > 0) 1424 debug3("timeout: %d ms remain after connect", timeout_ms); 1425 1426 /* 1427 * If we successfully made the connection and we have hostbased auth 1428 * enabled, load the public keys so we can later use the ssh-keysign 1429 * helper to sign challenges. 1430 */ 1431 sensitive_data.nkeys = 0; 1432 sensitive_data.keys = NULL; 1433 if (options.hostbased_authentication) { 1434 sensitive_data.nkeys = 10; 1435 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 1436 sizeof(struct sshkey)); 1437 1438 /* XXX check errors? */ 1439 #define L_PUBKEY(p,o) do { \ 1440 if ((o) >= sensitive_data.nkeys) \ 1441 fatal("%s pubkey out of array bounds", __func__); \ 1442 check_load(sshkey_load_public(p, &(sensitive_data.keys[o]), NULL), \ 1443 p, "pubkey"); \ 1444 } while (0) 1445 #define L_CERT(p,o) do { \ 1446 if ((o) >= sensitive_data.nkeys) \ 1447 fatal("%s cert out of array bounds", __func__); \ 1448 check_load(sshkey_load_cert(p, &(sensitive_data.keys[o])), p, "cert"); \ 1449 } while (0) 1450 1451 if (options.hostbased_authentication == 1) { 1452 L_CERT(_PATH_HOST_ECDSA_KEY_FILE, 0); 1453 L_CERT(_PATH_HOST_ED25519_KEY_FILE, 1); 1454 L_CERT(_PATH_HOST_RSA_KEY_FILE, 2); 1455 L_CERT(_PATH_HOST_DSA_KEY_FILE, 3); 1456 L_PUBKEY(_PATH_HOST_ECDSA_KEY_FILE, 4); 1457 L_PUBKEY(_PATH_HOST_ED25519_KEY_FILE, 5); 1458 L_PUBKEY(_PATH_HOST_RSA_KEY_FILE, 6); 1459 L_PUBKEY(_PATH_HOST_DSA_KEY_FILE, 7); 1460 L_CERT(_PATH_HOST_XMSS_KEY_FILE, 8); 1461 L_PUBKEY(_PATH_HOST_XMSS_KEY_FILE, 9); 1462 } 1463 } 1464 1465 /* Create ~/.ssh * directory if it doesn't already exist. */ 1466 if (config == NULL) { 1467 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 1468 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 1469 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) == -1) 1470 if (mkdir(buf, 0700) == -1) 1471 error("Could not create directory '%.200s'.", 1472 buf); 1473 } 1474 1475 /* load options.identity_files */ 1476 load_public_identity_files(pw); 1477 1478 /* optionally set the SSH_AUTHSOCKET_ENV_NAME variable */ 1479 if (options.identity_agent && 1480 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) { 1481 if (strcmp(options.identity_agent, "none") == 0) { 1482 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1483 } else { 1484 p = tilde_expand_filename(options.identity_agent, 1485 getuid()); 1486 cp = percent_expand(p, 1487 "d", pw->pw_dir, 1488 "h", host, 1489 "i", uidstr, 1490 "l", thishost, 1491 "r", options.user, 1492 "u", pw->pw_name, 1493 (char *)NULL); 1494 free(p); 1495 /* 1496 * If identity_agent represents an environment variable 1497 * then recheck that it is valid (since processing with 1498 * percent_expand() may have changed it) and substitute 1499 * its value. 1500 */ 1501 if (cp[0] == '$') { 1502 if (!valid_env_name(cp + 1)) { 1503 fatal("Invalid IdentityAgent " 1504 "environment variable name %s", cp); 1505 } 1506 if ((p = getenv(cp + 1)) == NULL) 1507 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1508 else 1509 setenv(SSH_AUTHSOCKET_ENV_NAME, p, 1); 1510 } else { 1511 /* identity_agent specifies a path directly */ 1512 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1); 1513 } 1514 free(cp); 1515 } 1516 } 1517 1518 if (options.forward_agent && (options.forward_agent_sock_path != NULL)) { 1519 p = tilde_expand_filename(options.forward_agent_sock_path, getuid()); 1520 cp = percent_expand(p, 1521 "d", pw->pw_dir, 1522 "h", host, 1523 "i", uidstr, 1524 "l", thishost, 1525 "r", options.user, 1526 "u", pw->pw_name, 1527 (char *)NULL); 1528 free(p); 1529 1530 if (cp[0] == '$') { 1531 if (!valid_env_name(cp + 1)) { 1532 fatal("Invalid ForwardAgent environment variable name %s", cp); 1533 } 1534 if ((p = getenv(cp + 1)) != NULL) 1535 forward_agent_sock_path = p; 1536 else 1537 options.forward_agent = 0; 1538 free(cp); 1539 } else { 1540 forward_agent_sock_path = cp; 1541 } 1542 } 1543 1544 /* Expand ~ in known host file names. */ 1545 tilde_expand_paths(options.system_hostfiles, 1546 options.num_system_hostfiles); 1547 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 1548 1549 ssh_signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 1550 ssh_signal(SIGCHLD, main_sigchld_handler); 1551 1552 /* Log into the remote system. Never returns if the login fails. */ 1553 ssh_login(ssh, &sensitive_data, host, (struct sockaddr *)&hostaddr, 1554 options.port, pw, timeout_ms); 1555 1556 if (ssh_packet_connection_is_on_socket(ssh)) { 1557 verbose("Authenticated to %s ([%s]:%d).", host, 1558 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); 1559 } else { 1560 verbose("Authenticated to %s (via proxy).", host); 1561 } 1562 1563 /* We no longer need the private host keys. Clear them now. */ 1564 if (sensitive_data.nkeys != 0) { 1565 for (i = 0; i < sensitive_data.nkeys; i++) { 1566 if (sensitive_data.keys[i] != NULL) { 1567 /* Destroys contents safely */ 1568 debug3("clear hostkey %d", i); 1569 sshkey_free(sensitive_data.keys[i]); 1570 sensitive_data.keys[i] = NULL; 1571 } 1572 } 1573 free(sensitive_data.keys); 1574 } 1575 for (i = 0; i < options.num_identity_files; i++) { 1576 free(options.identity_files[i]); 1577 options.identity_files[i] = NULL; 1578 if (options.identity_keys[i]) { 1579 sshkey_free(options.identity_keys[i]); 1580 options.identity_keys[i] = NULL; 1581 } 1582 } 1583 for (i = 0; i < options.num_certificate_files; i++) { 1584 free(options.certificate_files[i]); 1585 options.certificate_files[i] = NULL; 1586 } 1587 1588 skip_connect: 1589 exit_status = ssh_session2(ssh, pw); 1590 ssh_packet_close(ssh); 1591 1592 if (options.control_path != NULL && muxserver_sock != -1) 1593 unlink(options.control_path); 1594 1595 /* Kill ProxyCommand if it is running. */ 1596 ssh_kill_proxy_command(); 1597 1598 return exit_status; 1599 } 1600 1601 static void 1602 control_persist_detach(void) 1603 { 1604 pid_t pid; 1605 int devnull, keep_stderr; 1606 1607 debug("%s: backgrounding master process", __func__); 1608 1609 /* 1610 * master (current process) into the background, and make the 1611 * foreground process a client of the backgrounded master. 1612 */ 1613 switch ((pid = fork())) { 1614 case -1: 1615 fatal("%s: fork: %s", __func__, strerror(errno)); 1616 case 0: 1617 /* Child: master process continues mainloop */ 1618 break; 1619 default: 1620 /* Parent: set up mux slave to connect to backgrounded master */ 1621 debug2("%s: background process is %ld", __func__, (long)pid); 1622 stdin_null_flag = ostdin_null_flag; 1623 options.request_tty = orequest_tty; 1624 tty_flag = otty_flag; 1625 close(muxserver_sock); 1626 muxserver_sock = -1; 1627 options.control_master = SSHCTL_MASTER_NO; 1628 muxclient(options.control_path); 1629 /* muxclient() doesn't return on success. */ 1630 fatal("Failed to connect to new control master"); 1631 } 1632 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1633 error("%s: open(\"/dev/null\"): %s", __func__, 1634 strerror(errno)); 1635 } else { 1636 keep_stderr = log_is_on_stderr() && debug_flag; 1637 if (dup2(devnull, STDIN_FILENO) == -1 || 1638 dup2(devnull, STDOUT_FILENO) == -1 || 1639 (!keep_stderr && dup2(devnull, STDERR_FILENO) == -1)) 1640 error("%s: dup2: %s", __func__, strerror(errno)); 1641 if (devnull > STDERR_FILENO) 1642 close(devnull); 1643 } 1644 daemon(1, 1); 1645 setproctitle("%s [mux]", options.control_path); 1646 } 1647 1648 /* Do fork() after authentication. Used by "ssh -f" */ 1649 static void 1650 fork_postauth(void) 1651 { 1652 if (need_controlpersist_detach) 1653 control_persist_detach(); 1654 debug("forking to background"); 1655 fork_after_authentication_flag = 0; 1656 if (daemon(1, 1) == -1) 1657 fatal("daemon() failed: %.200s", strerror(errno)); 1658 } 1659 1660 /* Callback for remote forward global requests */ 1661 static void 1662 ssh_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt) 1663 { 1664 struct Forward *rfwd = (struct Forward *)ctxt; 1665 u_int port; 1666 int r; 1667 1668 /* XXX verbose() on failure? */ 1669 debug("remote forward %s for: listen %s%s%d, connect %s:%d", 1670 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1671 rfwd->listen_path ? rfwd->listen_path : 1672 rfwd->listen_host ? rfwd->listen_host : "", 1673 (rfwd->listen_path || rfwd->listen_host) ? ":" : "", 1674 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path : 1675 rfwd->connect_host, rfwd->connect_port); 1676 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) { 1677 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1678 if ((r = sshpkt_get_u32(ssh, &port)) != 0) 1679 fatal("%s: %s", __func__, ssh_err(r)); 1680 if (port > 65535) { 1681 error("Invalid allocated port %u for remote " 1682 "forward to %s:%d", port, 1683 rfwd->connect_host, rfwd->connect_port); 1684 /* Ensure failure processing runs below */ 1685 type = SSH2_MSG_REQUEST_FAILURE; 1686 channel_update_permission(ssh, 1687 rfwd->handle, -1); 1688 } else { 1689 rfwd->allocated_port = (int)port; 1690 logit("Allocated port %u for remote " 1691 "forward to %s:%d", 1692 rfwd->allocated_port, rfwd->connect_host, 1693 rfwd->connect_port); 1694 channel_update_permission(ssh, 1695 rfwd->handle, rfwd->allocated_port); 1696 } 1697 } else { 1698 channel_update_permission(ssh, rfwd->handle, -1); 1699 } 1700 } 1701 1702 if (type == SSH2_MSG_REQUEST_FAILURE) { 1703 if (options.exit_on_forward_failure) { 1704 if (rfwd->listen_path != NULL) 1705 fatal("Error: remote port forwarding failed " 1706 "for listen path %s", rfwd->listen_path); 1707 else 1708 fatal("Error: remote port forwarding failed " 1709 "for listen port %d", rfwd->listen_port); 1710 } else { 1711 if (rfwd->listen_path != NULL) 1712 logit("Warning: remote port forwarding failed " 1713 "for listen path %s", rfwd->listen_path); 1714 else 1715 logit("Warning: remote port forwarding failed " 1716 "for listen port %d", rfwd->listen_port); 1717 } 1718 } 1719 if (++remote_forward_confirms_received == options.num_remote_forwards) { 1720 debug("All remote forwarding requests processed"); 1721 if (fork_after_authentication_flag) 1722 fork_postauth(); 1723 } 1724 } 1725 1726 static void 1727 client_cleanup_stdio_fwd(struct ssh *ssh, int id, void *arg) 1728 { 1729 debug("stdio forwarding: done"); 1730 cleanup_exit(0); 1731 } 1732 1733 static void 1734 ssh_stdio_confirm(struct ssh *ssh, int id, int success, void *arg) 1735 { 1736 if (!success) 1737 fatal("stdio forwarding failed"); 1738 } 1739 1740 static void 1741 ssh_init_stdio_forwarding(struct ssh *ssh) 1742 { 1743 Channel *c; 1744 int in, out; 1745 1746 if (options.stdio_forward_host == NULL) 1747 return; 1748 1749 debug3("%s: %s:%d", __func__, options.stdio_forward_host, 1750 options.stdio_forward_port); 1751 1752 if ((in = dup(STDIN_FILENO)) == -1 || 1753 (out = dup(STDOUT_FILENO)) == -1) 1754 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1755 if ((c = channel_connect_stdio_fwd(ssh, options.stdio_forward_host, 1756 options.stdio_forward_port, in, out)) == NULL) 1757 fatal("%s: channel_connect_stdio_fwd failed", __func__); 1758 channel_register_cleanup(ssh, c->self, client_cleanup_stdio_fwd, 0); 1759 channel_register_open_confirm(ssh, c->self, ssh_stdio_confirm, NULL); 1760 } 1761 1762 static void 1763 ssh_init_forwarding(struct ssh *ssh, char **ifname) 1764 { 1765 int success = 0; 1766 int i; 1767 1768 /* Initiate local TCP/IP port forwardings. */ 1769 for (i = 0; i < options.num_local_forwards; i++) { 1770 debug("Local connections to %.200s:%d forwarded to remote " 1771 "address %.200s:%d", 1772 (options.local_forwards[i].listen_path != NULL) ? 1773 options.local_forwards[i].listen_path : 1774 (options.local_forwards[i].listen_host == NULL) ? 1775 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") : 1776 options.local_forwards[i].listen_host, 1777 options.local_forwards[i].listen_port, 1778 (options.local_forwards[i].connect_path != NULL) ? 1779 options.local_forwards[i].connect_path : 1780 options.local_forwards[i].connect_host, 1781 options.local_forwards[i].connect_port); 1782 success += channel_setup_local_fwd_listener(ssh, 1783 &options.local_forwards[i], &options.fwd_opts); 1784 } 1785 if (i > 0 && success != i && options.exit_on_forward_failure) 1786 fatal("Could not request local forwarding."); 1787 if (i > 0 && success == 0) 1788 error("Could not request local forwarding."); 1789 1790 /* Initiate remote TCP/IP port forwardings. */ 1791 for (i = 0; i < options.num_remote_forwards; i++) { 1792 debug("Remote connections from %.200s:%d forwarded to " 1793 "local address %.200s:%d", 1794 (options.remote_forwards[i].listen_path != NULL) ? 1795 options.remote_forwards[i].listen_path : 1796 (options.remote_forwards[i].listen_host == NULL) ? 1797 "LOCALHOST" : options.remote_forwards[i].listen_host, 1798 options.remote_forwards[i].listen_port, 1799 (options.remote_forwards[i].connect_path != NULL) ? 1800 options.remote_forwards[i].connect_path : 1801 options.remote_forwards[i].connect_host, 1802 options.remote_forwards[i].connect_port); 1803 options.remote_forwards[i].handle = 1804 channel_request_remote_forwarding(ssh, 1805 &options.remote_forwards[i]); 1806 if (options.remote_forwards[i].handle < 0) { 1807 if (options.exit_on_forward_failure) 1808 fatal("Could not request remote forwarding."); 1809 else 1810 logit("Warning: Could not request remote " 1811 "forwarding."); 1812 } else { 1813 client_register_global_confirm( 1814 ssh_confirm_remote_forward, 1815 &options.remote_forwards[i]); 1816 } 1817 } 1818 1819 /* Initiate tunnel forwarding. */ 1820 if (options.tun_open != SSH_TUNMODE_NO) { 1821 if ((*ifname = client_request_tun_fwd(ssh, 1822 options.tun_open, options.tun_local, 1823 options.tun_remote)) == NULL) { 1824 if (options.exit_on_forward_failure) 1825 fatal("Could not request tunnel forwarding."); 1826 else 1827 error("Could not request tunnel forwarding."); 1828 } 1829 } 1830 } 1831 1832 static void 1833 check_agent_present(void) 1834 { 1835 int r; 1836 1837 if (options.forward_agent) { 1838 /* Clear agent forwarding if we don't have an agent. */ 1839 if ((r = ssh_get_authentication_socket(NULL)) != 0) { 1840 options.forward_agent = 0; 1841 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1842 debug("ssh_get_authentication_socket: %s", 1843 ssh_err(r)); 1844 } 1845 } 1846 } 1847 1848 static void 1849 ssh_session2_setup(struct ssh *ssh, int id, int success, void *arg) 1850 { 1851 extern char **environ; 1852 const char *display; 1853 int r, interactive = tty_flag; 1854 char *proto = NULL, *data = NULL; 1855 1856 if (!success) 1857 return; /* No need for error message, channels code sens one */ 1858 1859 display = getenv("DISPLAY"); 1860 if (display == NULL && options.forward_x11) 1861 debug("X11 forwarding requested but DISPLAY not set"); 1862 if (options.forward_x11 && client_x11_get_proto(ssh, display, 1863 options.xauth_location, options.forward_x11_trusted, 1864 options.forward_x11_timeout, &proto, &data) == 0) { 1865 /* Request forwarding with authentication spoofing. */ 1866 debug("Requesting X11 forwarding with authentication " 1867 "spoofing."); 1868 x11_request_forwarding_with_spoofing(ssh, id, display, proto, 1869 data, 1); 1870 client_expect_confirm(ssh, id, "X11 forwarding", CONFIRM_WARN); 1871 /* XXX exit_on_forward_failure */ 1872 interactive = 1; 1873 } 1874 1875 check_agent_present(); 1876 if (options.forward_agent) { 1877 debug("Requesting authentication agent forwarding."); 1878 channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0); 1879 if ((r = sshpkt_send(ssh)) != 0) 1880 fatal("%s: %s", __func__, ssh_err(r)); 1881 } 1882 1883 /* Tell the packet module whether this is an interactive session. */ 1884 ssh_packet_set_interactive(ssh, interactive, 1885 options.ip_qos_interactive, options.ip_qos_bulk); 1886 1887 client_session2_setup(ssh, id, tty_flag, subsystem_flag, getenv("TERM"), 1888 NULL, fileno(stdin), command, environ); 1889 } 1890 1891 /* open new channel for a session */ 1892 static int 1893 ssh_session2_open(struct ssh *ssh) 1894 { 1895 Channel *c; 1896 int window, packetmax, in, out, err; 1897 1898 if (stdin_null_flag) { 1899 in = open(_PATH_DEVNULL, O_RDONLY); 1900 } else { 1901 in = dup(STDIN_FILENO); 1902 } 1903 out = dup(STDOUT_FILENO); 1904 err = dup(STDERR_FILENO); 1905 1906 if (in == -1 || out == -1 || err == -1) 1907 fatal("dup() in/out/err failed"); 1908 1909 /* enable nonblocking unless tty */ 1910 if (!isatty(in)) 1911 set_nonblock(in); 1912 if (!isatty(out)) 1913 set_nonblock(out); 1914 if (!isatty(err)) 1915 set_nonblock(err); 1916 1917 window = CHAN_SES_WINDOW_DEFAULT; 1918 packetmax = CHAN_SES_PACKET_DEFAULT; 1919 if (tty_flag) { 1920 window >>= 1; 1921 packetmax >>= 1; 1922 } 1923 c = channel_new(ssh, 1924 "session", SSH_CHANNEL_OPENING, in, out, err, 1925 window, packetmax, CHAN_EXTENDED_WRITE, 1926 "client-session", /*nonblock*/0); 1927 1928 debug3("%s: channel_new: %d", __func__, c->self); 1929 1930 channel_send_open(ssh, c->self); 1931 if (!no_shell_flag) 1932 channel_register_open_confirm(ssh, c->self, 1933 ssh_session2_setup, NULL); 1934 1935 return c->self; 1936 } 1937 1938 static int 1939 ssh_session2(struct ssh *ssh, struct passwd *pw) 1940 { 1941 int r, devnull, id = -1; 1942 char *cp, *tun_fwd_ifname = NULL; 1943 1944 /* XXX should be pre-session */ 1945 if (!options.control_persist) 1946 ssh_init_stdio_forwarding(ssh); 1947 1948 ssh_init_forwarding(ssh, &tun_fwd_ifname); 1949 1950 if (options.local_command != NULL) { 1951 debug3("expanding LocalCommand: %s", options.local_command); 1952 cp = options.local_command; 1953 options.local_command = percent_expand(cp, 1954 "C", conn_hash_hex, 1955 "L", shorthost, 1956 "d", pw->pw_dir, 1957 "h", host, 1958 "i", uidstr, 1959 "l", thishost, 1960 "n", host_arg, 1961 "p", portstr, 1962 "r", options.user, 1963 "u", pw->pw_name, 1964 "T", tun_fwd_ifname == NULL ? "NONE" : tun_fwd_ifname, 1965 (char *)NULL); 1966 debug3("expanded LocalCommand: %s", options.local_command); 1967 free(cp); 1968 } 1969 1970 /* Start listening for multiplex clients */ 1971 if (!ssh_packet_get_mux(ssh)) 1972 muxserver_listen(ssh); 1973 1974 /* 1975 * If we are in control persist mode and have a working mux listen 1976 * socket, then prepare to background ourselves and have a foreground 1977 * client attach as a control slave. 1978 * NB. we must save copies of the flags that we override for 1979 * the backgrounding, since we defer attachment of the slave until 1980 * after the connection is fully established (in particular, 1981 * async rfwd replies have been received for ExitOnForwardFailure). 1982 */ 1983 if (options.control_persist && muxserver_sock != -1) { 1984 ostdin_null_flag = stdin_null_flag; 1985 ono_shell_flag = no_shell_flag; 1986 orequest_tty = options.request_tty; 1987 otty_flag = tty_flag; 1988 stdin_null_flag = 1; 1989 no_shell_flag = 1; 1990 tty_flag = 0; 1991 if (!fork_after_authentication_flag) 1992 need_controlpersist_detach = 1; 1993 fork_after_authentication_flag = 1; 1994 } 1995 /* 1996 * ControlPersist mux listen socket setup failed, attempt the 1997 * stdio forward setup that we skipped earlier. 1998 */ 1999 if (options.control_persist && muxserver_sock == -1) 2000 ssh_init_stdio_forwarding(ssh); 2001 2002 if (!no_shell_flag) 2003 id = ssh_session2_open(ssh); 2004 else { 2005 ssh_packet_set_interactive(ssh, 2006 options.control_master == SSHCTL_MASTER_NO, 2007 options.ip_qos_interactive, options.ip_qos_bulk); 2008 } 2009 2010 /* If we don't expect to open a new session, then disallow it */ 2011 if (options.control_master == SSHCTL_MASTER_NO && 2012 (datafellows & SSH_NEW_OPENSSH)) { 2013 debug("Requesting no-more-sessions@openssh.com"); 2014 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 2015 (r = sshpkt_put_cstring(ssh, 2016 "no-more-sessions@openssh.com")) != 0 || 2017 (r = sshpkt_put_u8(ssh, 0)) != 0 || 2018 (r = sshpkt_send(ssh)) != 0) 2019 fatal("%s: %s", __func__, ssh_err(r)); 2020 } 2021 2022 /* Execute a local command */ 2023 if (options.local_command != NULL && 2024 options.permit_local_command) 2025 ssh_local_cmd(options.local_command); 2026 2027 /* 2028 * stdout is now owned by the session channel; clobber it here 2029 * so future channel closes are propagated to the local fd. 2030 * NB. this can only happen after LocalCommand has completed, 2031 * as it may want to write to stdout. 2032 */ 2033 if (!need_controlpersist_detach) { 2034 if ((devnull = open(_PATH_DEVNULL, O_WRONLY)) == -1) 2035 error("%s: open %s: %s", __func__, 2036 _PATH_DEVNULL, strerror(errno)); 2037 if (dup2(devnull, STDOUT_FILENO) == -1) 2038 fatal("%s: dup2() stdout failed", __func__); 2039 if (devnull > STDERR_FILENO) 2040 close(devnull); 2041 } 2042 2043 /* 2044 * If requested and we are not interested in replies to remote 2045 * forwarding requests, then let ssh continue in the background. 2046 */ 2047 if (fork_after_authentication_flag) { 2048 if (options.exit_on_forward_failure && 2049 options.num_remote_forwards > 0) { 2050 debug("deferring postauth fork until remote forward " 2051 "confirmation received"); 2052 } else 2053 fork_postauth(); 2054 } 2055 2056 return client_loop(ssh, tty_flag, tty_flag ? 2057 options.escape_char : SSH_ESCAPECHAR_NONE, id); 2058 } 2059 2060 /* Loads all IdentityFile and CertificateFile keys */ 2061 static void 2062 load_public_identity_files(struct passwd *pw) 2063 { 2064 char *filename, *cp; 2065 struct sshkey *public; 2066 int i; 2067 u_int n_ids, n_certs; 2068 char *identity_files[SSH_MAX_IDENTITY_FILES]; 2069 struct sshkey *identity_keys[SSH_MAX_IDENTITY_FILES]; 2070 int identity_file_userprovided[SSH_MAX_IDENTITY_FILES]; 2071 char *certificate_files[SSH_MAX_CERTIFICATE_FILES]; 2072 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES]; 2073 int certificate_file_userprovided[SSH_MAX_CERTIFICATE_FILES]; 2074 #ifdef ENABLE_PKCS11 2075 struct sshkey **keys = NULL; 2076 char **comments = NULL; 2077 int nkeys; 2078 #endif /* PKCS11 */ 2079 2080 n_ids = n_certs = 0; 2081 memset(identity_files, 0, sizeof(identity_files)); 2082 memset(identity_keys, 0, sizeof(identity_keys)); 2083 memset(identity_file_userprovided, 0, 2084 sizeof(identity_file_userprovided)); 2085 memset(certificate_files, 0, sizeof(certificate_files)); 2086 memset(certificates, 0, sizeof(certificates)); 2087 memset(certificate_file_userprovided, 0, 2088 sizeof(certificate_file_userprovided)); 2089 2090 #ifdef ENABLE_PKCS11 2091 if (options.pkcs11_provider != NULL && 2092 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 2093 (pkcs11_init(!options.batch_mode) == 0) && 2094 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 2095 &keys, &comments)) > 0) { 2096 for (i = 0; i < nkeys; i++) { 2097 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 2098 sshkey_free(keys[i]); 2099 free(comments[i]); 2100 continue; 2101 } 2102 identity_keys[n_ids] = keys[i]; 2103 identity_files[n_ids] = comments[i]; /* transferred */ 2104 n_ids++; 2105 } 2106 free(keys); 2107 free(comments); 2108 } 2109 #endif /* ENABLE_PKCS11 */ 2110 for (i = 0; i < options.num_identity_files; i++) { 2111 if (n_ids >= SSH_MAX_IDENTITY_FILES || 2112 strcasecmp(options.identity_files[i], "none") == 0) { 2113 free(options.identity_files[i]); 2114 options.identity_files[i] = NULL; 2115 continue; 2116 } 2117 cp = tilde_expand_filename(options.identity_files[i], getuid()); 2118 filename = percent_expand(cp, "d", pw->pw_dir, 2119 "u", pw->pw_name, "l", thishost, "h", host, 2120 "r", options.user, (char *)NULL); 2121 free(cp); 2122 check_load(sshkey_load_public(filename, &public, NULL), 2123 filename, "pubkey"); 2124 debug("identity file %s type %d", filename, 2125 public ? public->type : -1); 2126 free(options.identity_files[i]); 2127 identity_files[n_ids] = filename; 2128 identity_keys[n_ids] = public; 2129 identity_file_userprovided[n_ids] = 2130 options.identity_file_userprovided[i]; 2131 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 2132 continue; 2133 2134 /* 2135 * If no certificates have been explicitly listed then try 2136 * to add the default certificate variant too. 2137 */ 2138 if (options.num_certificate_files != 0) 2139 continue; 2140 xasprintf(&cp, "%s-cert", filename); 2141 check_load(sshkey_load_public(cp, &public, NULL), 2142 filename, "pubkey"); 2143 debug("identity file %s type %d", cp, 2144 public ? public->type : -1); 2145 if (public == NULL) { 2146 free(cp); 2147 continue; 2148 } 2149 if (!sshkey_is_cert(public)) { 2150 debug("%s: key %s type %s is not a certificate", 2151 __func__, cp, sshkey_type(public)); 2152 sshkey_free(public); 2153 free(cp); 2154 continue; 2155 } 2156 /* NB. leave filename pointing to private key */ 2157 identity_files[n_ids] = xstrdup(filename); 2158 identity_keys[n_ids] = public; 2159 identity_file_userprovided[n_ids] = 2160 options.identity_file_userprovided[i]; 2161 n_ids++; 2162 } 2163 2164 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES) 2165 fatal("%s: too many certificates", __func__); 2166 for (i = 0; i < options.num_certificate_files; i++) { 2167 cp = tilde_expand_filename(options.certificate_files[i], 2168 getuid()); 2169 filename = percent_expand(cp, 2170 "d", pw->pw_dir, 2171 "h", host, 2172 "i", uidstr, 2173 "l", thishost, 2174 "r", options.user, 2175 "u", pw->pw_name, 2176 (char *)NULL); 2177 free(cp); 2178 2179 check_load(sshkey_load_public(filename, &public, NULL), 2180 filename, "certificate"); 2181 debug("certificate file %s type %d", filename, 2182 public ? public->type : -1); 2183 free(options.certificate_files[i]); 2184 options.certificate_files[i] = NULL; 2185 if (public == NULL) { 2186 free(filename); 2187 continue; 2188 } 2189 if (!sshkey_is_cert(public)) { 2190 debug("%s: key %s type %s is not a certificate", 2191 __func__, filename, sshkey_type(public)); 2192 sshkey_free(public); 2193 free(filename); 2194 continue; 2195 } 2196 certificate_files[n_certs] = filename; 2197 certificates[n_certs] = public; 2198 certificate_file_userprovided[n_certs] = 2199 options.certificate_file_userprovided[i]; 2200 ++n_certs; 2201 } 2202 2203 options.num_identity_files = n_ids; 2204 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 2205 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 2206 memcpy(options.identity_file_userprovided, 2207 identity_file_userprovided, sizeof(identity_file_userprovided)); 2208 2209 options.num_certificate_files = n_certs; 2210 memcpy(options.certificate_files, 2211 certificate_files, sizeof(certificate_files)); 2212 memcpy(options.certificates, certificates, sizeof(certificates)); 2213 memcpy(options.certificate_file_userprovided, 2214 certificate_file_userprovided, 2215 sizeof(certificate_file_userprovided)); 2216 } 2217 2218 static void 2219 main_sigchld_handler(int sig) 2220 { 2221 int save_errno = errno; 2222 pid_t pid; 2223 int status; 2224 2225 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 2226 (pid == -1 && errno == EINTR)) 2227 ; 2228 errno = save_errno; 2229 } 2230