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