1 /* $OpenBSD: ssh.c,v 1.501 2019/04/23 11:56:41 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 <unistd.h> 64 #include <limits.h> 65 #include <locale.h> 66 67 #ifdef WITH_OPENSSL 68 #include <openssl/evp.h> 69 #include <openssl/err.h> 70 #endif 71 72 #include "xmalloc.h" 73 #include "ssh.h" 74 #include "ssh2.h" 75 #include "canohost.h" 76 #include "compat.h" 77 #include "cipher.h" 78 #include "digest.h" 79 #include "packet.h" 80 #include "sshbuf.h" 81 #include "channels.h" 82 #include "sshkey.h" 83 #include "authfd.h" 84 #include "authfile.h" 85 #include "pathnames.h" 86 #include "dispatch.h" 87 #include "clientloop.h" 88 #include "log.h" 89 #include "misc.h" 90 #include "readconf.h" 91 #include "sshconnect.h" 92 #include "kex.h" 93 #include "mac.h" 94 #include "sshpty.h" 95 #include "match.h" 96 #include "msg.h" 97 #include "version.h" 98 #include "ssherr.h" 99 #include "myproposal.h" 100 101 #ifdef ENABLE_PKCS11 102 #include "ssh-pkcs11.h" 103 #endif 104 105 extern char *__progname; 106 107 /* Flag indicating whether debug mode is on. May be set on the command line. */ 108 int debug_flag = 0; 109 110 /* Flag indicating whether a tty should be requested */ 111 int tty_flag = 0; 112 113 /* don't exec a shell */ 114 int no_shell_flag = 0; 115 116 /* 117 * Flag indicating that nothing should be read from stdin. This can be set 118 * on the command line. 119 */ 120 int stdin_null_flag = 0; 121 122 /* 123 * Flag indicating that the current process should be backgrounded and 124 * a new slave launched in the foreground for ControlPersist. 125 */ 126 int need_controlpersist_detach = 0; 127 128 /* Copies of flags for ControlPersist foreground slave */ 129 int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty; 130 131 /* 132 * Flag indicating that ssh should fork after authentication. This is useful 133 * so that the passphrase can be entered manually, and then ssh goes to the 134 * background. 135 */ 136 int fork_after_authentication_flag = 0; 137 138 /* 139 * General data structure for command line options and options configurable 140 * in configuration files. See readconf.h. 141 */ 142 Options options; 143 144 /* optional user configfile */ 145 char *config = NULL; 146 147 /* 148 * Name of the host we are connecting to. This is the name given on the 149 * command line, or the HostName specified for the user-supplied name in a 150 * configuration file. 151 */ 152 char *host; 153 154 /* Various strings used to to percent_expand() arguments */ 155 static char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 156 static char uidstr[32], *host_arg, *conn_hash_hex; 157 158 /* socket address the host resolves to */ 159 struct sockaddr_storage hostaddr; 160 161 /* Private host keys. */ 162 Sensitive sensitive_data; 163 164 /* command to be executed */ 165 struct sshbuf *command; 166 167 /* Should we execute a command or invoke a subsystem? */ 168 int subsystem_flag = 0; 169 170 /* # of replies received for global requests */ 171 static int remote_forward_confirms_received = 0; 172 173 /* mux.c */ 174 extern int muxserver_sock; 175 extern u_int muxclient_command; 176 177 /* Prints a help message to the user. This function never returns. */ 178 179 static void 180 usage(void) 181 { 182 fprintf(stderr, 183 "usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]\n" 184 " [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]\n" 185 " [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]\n" 186 " [-i identity_file] [-J [user@]host[:port]] [-L address]\n" 187 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" 188 " [-Q query_option] [-R address] [-S ctl_path] [-W host:port]\n" 189 " [-w local_tun[:remote_tun]] destination [command]\n" 190 ); 191 exit(255); 192 } 193 194 static int ssh_session2(struct ssh *, struct passwd *); 195 static void load_public_identity_files(struct passwd *); 196 static void main_sigchld_handler(int); 197 198 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 199 static void 200 tilde_expand_paths(char **paths, u_int num_paths) 201 { 202 u_int i; 203 char *cp; 204 205 for (i = 0; i < num_paths; i++) { 206 cp = tilde_expand_filename(paths[i], getuid()); 207 free(paths[i]); 208 paths[i] = cp; 209 } 210 } 211 212 /* 213 * Attempt to resolve a host name / port to a set of addresses and 214 * optionally return any CNAMEs encountered along the way. 215 * Returns NULL on failure. 216 * NB. this function must operate with a options having undefined members. 217 */ 218 static struct addrinfo * 219 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen) 220 { 221 char strport[NI_MAXSERV]; 222 struct addrinfo hints, *res; 223 int gaierr; 224 LogLevel loglevel = SYSLOG_LEVEL_DEBUG1; 225 226 if (port <= 0) 227 port = default_ssh_port(); 228 229 snprintf(strport, sizeof strport, "%d", port); 230 memset(&hints, 0, sizeof(hints)); 231 hints.ai_family = options.address_family == -1 ? 232 AF_UNSPEC : options.address_family; 233 hints.ai_socktype = SOCK_STREAM; 234 if (cname != NULL) 235 hints.ai_flags = AI_CANONNAME; 236 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 237 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) 238 loglevel = SYSLOG_LEVEL_ERROR; 239 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", 240 __progname, name, ssh_gai_strerror(gaierr)); 241 return NULL; 242 } 243 if (cname != NULL && res->ai_canonname != NULL) { 244 if (strlcpy(cname, res->ai_canonname, clen) >= clen) { 245 error("%s: host \"%s\" cname \"%s\" too long (max %lu)", 246 __func__, name, res->ai_canonname, (u_long)clen); 247 if (clen > 0) 248 *cname = '\0'; 249 } 250 } 251 return res; 252 } 253 254 /* Returns non-zero if name can only be an address and not a hostname */ 255 static int 256 is_addr_fast(const char *name) 257 { 258 return (strchr(name, '%') != NULL || strchr(name, ':') != NULL || 259 strspn(name, "0123456789.") == strlen(name)); 260 } 261 262 /* Returns non-zero if name represents a valid, single address */ 263 static int 264 is_addr(const char *name) 265 { 266 char strport[NI_MAXSERV]; 267 struct addrinfo hints, *res; 268 269 if (is_addr_fast(name)) 270 return 1; 271 272 snprintf(strport, sizeof strport, "%u", default_ssh_port()); 273 memset(&hints, 0, sizeof(hints)); 274 hints.ai_family = options.address_family == -1 ? 275 AF_UNSPEC : options.address_family; 276 hints.ai_socktype = SOCK_STREAM; 277 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 278 if (getaddrinfo(name, strport, &hints, &res) != 0) 279 return 0; 280 if (res == NULL || res->ai_next != NULL) { 281 freeaddrinfo(res); 282 return 0; 283 } 284 freeaddrinfo(res); 285 return 1; 286 } 287 288 /* 289 * Attempt to resolve a numeric host address / port to a single address. 290 * Returns a canonical address string. 291 * Returns NULL on failure. 292 * NB. this function must operate with a options having undefined members. 293 */ 294 static struct addrinfo * 295 resolve_addr(const char *name, int port, char *caddr, size_t clen) 296 { 297 char addr[NI_MAXHOST], strport[NI_MAXSERV]; 298 struct addrinfo hints, *res; 299 int gaierr; 300 301 if (port <= 0) 302 port = default_ssh_port(); 303 snprintf(strport, sizeof strport, "%u", port); 304 memset(&hints, 0, sizeof(hints)); 305 hints.ai_family = options.address_family == -1 ? 306 AF_UNSPEC : options.address_family; 307 hints.ai_socktype = SOCK_STREAM; 308 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 309 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 310 debug2("%s: could not resolve name %.100s as address: %s", 311 __func__, name, ssh_gai_strerror(gaierr)); 312 return NULL; 313 } 314 if (res == NULL) { 315 debug("%s: getaddrinfo %.100s returned no addresses", 316 __func__, name); 317 return NULL; 318 } 319 if (res->ai_next != NULL) { 320 debug("%s: getaddrinfo %.100s returned multiple addresses", 321 __func__, name); 322 goto fail; 323 } 324 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen, 325 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) { 326 debug("%s: Could not format address for name %.100s: %s", 327 __func__, name, ssh_gai_strerror(gaierr)); 328 goto fail; 329 } 330 if (strlcpy(caddr, addr, clen) >= clen) { 331 error("%s: host \"%s\" addr \"%s\" too long (max %lu)", 332 __func__, name, addr, (u_long)clen); 333 if (clen > 0) 334 *caddr = '\0'; 335 fail: 336 freeaddrinfo(res); 337 return NULL; 338 } 339 return res; 340 } 341 342 /* 343 * Check whether the cname is a permitted replacement for the hostname 344 * and perform the replacement if it is. 345 * NB. this function must operate with a options having undefined members. 346 */ 347 static int 348 check_follow_cname(int direct, char **namep, const char *cname) 349 { 350 int i; 351 struct allowed_cname *rule; 352 353 if (*cname == '\0' || options.num_permitted_cnames == 0 || 354 strcmp(*namep, cname) == 0) 355 return 0; 356 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 357 return 0; 358 /* 359 * Don't attempt to canonicalize names that will be interpreted by 360 * a proxy or jump host unless the user specifically requests so. 361 */ 362 if (!direct && 363 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 364 return 0; 365 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname); 366 for (i = 0; i < options.num_permitted_cnames; i++) { 367 rule = options.permitted_cnames + i; 368 if (match_pattern_list(*namep, rule->source_list, 1) != 1 || 369 match_pattern_list(cname, rule->target_list, 1) != 1) 370 continue; 371 verbose("Canonicalized DNS aliased hostname " 372 "\"%s\" => \"%s\"", *namep, cname); 373 free(*namep); 374 *namep = xstrdup(cname); 375 return 1; 376 } 377 return 0; 378 } 379 380 /* 381 * Attempt to resolve the supplied hostname after applying the user's 382 * canonicalization rules. Returns the address list for the host or NULL 383 * if no name was found after canonicalization. 384 * NB. this function must operate with a options having undefined members. 385 */ 386 static struct addrinfo * 387 resolve_canonicalize(char **hostp, int port) 388 { 389 int i, direct, ndots; 390 char *cp, *fullhost, newname[NI_MAXHOST]; 391 struct addrinfo *addrs; 392 393 /* 394 * Attempt to canonicalise addresses, regardless of 395 * whether hostname canonicalisation was requested 396 */ 397 if ((addrs = resolve_addr(*hostp, port, 398 newname, sizeof(newname))) != NULL) { 399 debug2("%s: hostname %.100s is address", __func__, *hostp); 400 if (strcasecmp(*hostp, newname) != 0) { 401 debug2("%s: canonicalised address \"%s\" => \"%s\"", 402 __func__, *hostp, newname); 403 free(*hostp); 404 *hostp = xstrdup(newname); 405 } 406 return addrs; 407 } 408 409 /* 410 * If this looks like an address but didn't parse as one, it might 411 * be an address with an invalid interface scope. Skip further 412 * attempts at canonicalisation. 413 */ 414 if (is_addr_fast(*hostp)) { 415 debug("%s: hostname %.100s is an unrecognised address", 416 __func__, *hostp); 417 return NULL; 418 } 419 420 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 421 return NULL; 422 423 /* 424 * Don't attempt to canonicalize names that will be interpreted by 425 * a proxy unless the user specifically requests so. 426 */ 427 direct = option_clear_or_none(options.proxy_command) && 428 options.jump_host == NULL; 429 if (!direct && 430 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 431 return NULL; 432 433 /* If domain name is anchored, then resolve it now */ 434 if ((*hostp)[strlen(*hostp) - 1] == '.') { 435 debug3("%s: name is fully qualified", __func__); 436 fullhost = xstrdup(*hostp); 437 if ((addrs = resolve_host(fullhost, port, 0, 438 newname, sizeof(newname))) != NULL) 439 goto found; 440 free(fullhost); 441 goto notfound; 442 } 443 444 /* Don't apply canonicalization to sufficiently-qualified hostnames */ 445 ndots = 0; 446 for (cp = *hostp; *cp != '\0'; cp++) { 447 if (*cp == '.') 448 ndots++; 449 } 450 if (ndots > options.canonicalize_max_dots) { 451 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)", 452 __func__, *hostp, options.canonicalize_max_dots); 453 return NULL; 454 } 455 /* Attempt each supplied suffix */ 456 for (i = 0; i < options.num_canonical_domains; i++) { 457 *newname = '\0'; 458 xasprintf(&fullhost, "%s.%s.", *hostp, 459 options.canonical_domains[i]); 460 debug3("%s: attempting \"%s\" => \"%s\"", __func__, 461 *hostp, fullhost); 462 if ((addrs = resolve_host(fullhost, port, 0, 463 newname, sizeof(newname))) == NULL) { 464 free(fullhost); 465 continue; 466 } 467 found: 468 /* Remove trailing '.' */ 469 fullhost[strlen(fullhost) - 1] = '\0'; 470 /* Follow CNAME if requested */ 471 if (!check_follow_cname(direct, &fullhost, newname)) { 472 debug("Canonicalized hostname \"%s\" => \"%s\"", 473 *hostp, fullhost); 474 } 475 free(*hostp); 476 *hostp = fullhost; 477 return addrs; 478 } 479 notfound: 480 if (!options.canonicalize_fallback_local) 481 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); 482 debug2("%s: host %s not found in any suffix", __func__, *hostp); 483 return NULL; 484 } 485 486 /* 487 * Check the result of hostkey loading, ignoring some errors and 488 * fatal()ing for others. 489 */ 490 static void 491 check_load(int r, const char *path, const char *message) 492 { 493 switch (r) { 494 case 0: 495 break; 496 case SSH_ERR_INTERNAL_ERROR: 497 case SSH_ERR_ALLOC_FAIL: 498 fatal("load %s \"%s\": %s", message, path, ssh_err(r)); 499 case SSH_ERR_SYSTEM_ERROR: 500 /* Ignore missing files */ 501 if (errno == ENOENT) 502 break; 503 /* FALLTHROUGH */ 504 default: 505 error("load %s \"%s\": %s", message, path, ssh_err(r)); 506 break; 507 } 508 } 509 510 /* 511 * Read per-user configuration file. Ignore the system wide config 512 * file if the user specifies a config file on the command line. 513 */ 514 static void 515 process_config_files(const char *host_name, struct passwd *pw, int final_pass, 516 int *want_final_pass) 517 { 518 char buf[PATH_MAX]; 519 int r; 520 521 if (config != NULL) { 522 if (strcasecmp(config, "none") != 0 && 523 !read_config_file(config, pw, host, host_name, &options, 524 SSHCONF_USERCONF | (final_pass ? SSHCONF_FINAL : 0), 525 want_final_pass)) 526 fatal("Can't open user config file %.100s: " 527 "%.100s", config, strerror(errno)); 528 } else { 529 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 530 _PATH_SSH_USER_CONFFILE); 531 if (r > 0 && (size_t)r < sizeof(buf)) 532 (void)read_config_file(buf, pw, host, host_name, 533 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF | 534 (final_pass ? SSHCONF_FINAL : 0), want_final_pass); 535 536 /* Read systemwide configuration file after user config. */ 537 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, 538 host, host_name, &options, 539 final_pass ? SSHCONF_FINAL : 0, want_final_pass); 540 } 541 } 542 543 /* Rewrite the port number in an addrinfo list of addresses */ 544 static void 545 set_addrinfo_port(struct addrinfo *addrs, int port) 546 { 547 struct addrinfo *addr; 548 549 for (addr = addrs; addr != NULL; addr = addr->ai_next) { 550 switch (addr->ai_family) { 551 case AF_INET: 552 ((struct sockaddr_in *)addr->ai_addr)-> 553 sin_port = htons(port); 554 break; 555 case AF_INET6: 556 ((struct sockaddr_in6 *)addr->ai_addr)-> 557 sin6_port = htons(port); 558 break; 559 } 560 } 561 } 562 563 /* 564 * Main program for the ssh client. 565 */ 566 int 567 main(int ac, char **av) 568 { 569 struct ssh *ssh = NULL; 570 int i, r, opt, exit_status, use_syslog, direct, timeout_ms; 571 int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0; 572 char *p, *cp, *line, *argv0, buf[PATH_MAX], *logfile; 573 char cname[NI_MAXHOST]; 574 struct stat st; 575 struct passwd *pw; 576 extern int optind, optreset; 577 extern char *optarg; 578 struct Forward fwd; 579 struct addrinfo *addrs = NULL; 580 struct ssh_digest_ctx *md; 581 u_char conn_hash[SSH_DIGEST_MAX_LENGTH]; 582 583 ssh_malloc_init(); /* must be called before any mallocs */ 584 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 585 sanitise_stdfd(); 586 587 /* 588 * Discard other fds that are hanging around. These can cause problem 589 * with backgrounded ssh processes started by ControlPersist. 590 */ 591 closefrom(STDERR_FILENO + 1); 592 593 if (getuid() != geteuid()) 594 fatal("ssh setuid not supported."); 595 if (getgid() != getegid()) 596 fatal("ssh setgid not supported."); 597 598 /* Get user data. */ 599 pw = getpwuid(getuid()); 600 if (!pw) { 601 logit("No user exists for uid %lu", (u_long)getuid()); 602 exit(255); 603 } 604 /* Take a copy of the returned structure. */ 605 pw = pwcopy(pw); 606 607 /* 608 * Set our umask to something reasonable, as some files are created 609 * with the default umask. This will make them world-readable but 610 * writable only by the owner, which is ok for all files for which we 611 * don't set the modes explicitly. 612 */ 613 umask(022); 614 615 setlocale(LC_CTYPE, ""); 616 617 /* 618 * Initialize option structure to indicate that no values have been 619 * set. 620 */ 621 initialize_options(&options); 622 623 /* 624 * Prepare main ssh transport/connection structures 625 */ 626 if ((ssh = ssh_alloc_session_state()) == NULL) 627 fatal("Couldn't allocate session state"); 628 channel_init_channels(ssh); 629 630 /* Parse command-line arguments. */ 631 host = NULL; 632 use_syslog = 0; 633 logfile = NULL; 634 argv0 = av[0]; 635 636 again: 637 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 638 "AB:CD:E:F:GI:J:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { 639 switch (opt) { 640 case '1': 641 fatal("SSH protocol v.1 is no longer supported"); 642 break; 643 case '2': 644 /* Ignored */ 645 break; 646 case '4': 647 options.address_family = AF_INET; 648 break; 649 case '6': 650 options.address_family = AF_INET6; 651 break; 652 case 'n': 653 stdin_null_flag = 1; 654 break; 655 case 'f': 656 fork_after_authentication_flag = 1; 657 stdin_null_flag = 1; 658 break; 659 case 'x': 660 options.forward_x11 = 0; 661 break; 662 case 'X': 663 options.forward_x11 = 1; 664 break; 665 case 'y': 666 use_syslog = 1; 667 break; 668 case 'E': 669 logfile = optarg; 670 break; 671 case 'G': 672 config_test = 1; 673 break; 674 case 'Y': 675 options.forward_x11 = 1; 676 options.forward_x11_trusted = 1; 677 break; 678 case 'g': 679 options.fwd_opts.gateway_ports = 1; 680 break; 681 case 'O': 682 if (options.stdio_forward_host != NULL) 683 fatal("Cannot specify multiplexing " 684 "command with -W"); 685 else if (muxclient_command != 0) 686 fatal("Multiplexing command already specified"); 687 if (strcmp(optarg, "check") == 0) 688 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 689 else if (strcmp(optarg, "forward") == 0) 690 muxclient_command = SSHMUX_COMMAND_FORWARD; 691 else if (strcmp(optarg, "exit") == 0) 692 muxclient_command = SSHMUX_COMMAND_TERMINATE; 693 else if (strcmp(optarg, "stop") == 0) 694 muxclient_command = SSHMUX_COMMAND_STOP; 695 else if (strcmp(optarg, "cancel") == 0) 696 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 697 else if (strcmp(optarg, "proxy") == 0) 698 muxclient_command = SSHMUX_COMMAND_PROXY; 699 else 700 fatal("Invalid multiplex command."); 701 break; 702 case 'P': /* deprecated */ 703 break; 704 case 'Q': 705 cp = NULL; 706 if (strcmp(optarg, "cipher") == 0) 707 cp = cipher_alg_list('\n', 0); 708 else if (strcmp(optarg, "cipher-auth") == 0) 709 cp = cipher_alg_list('\n', 1); 710 else if (strcmp(optarg, "mac") == 0) 711 cp = mac_alg_list('\n'); 712 else if (strcmp(optarg, "kex") == 0) 713 cp = kex_alg_list('\n'); 714 else if (strcmp(optarg, "key") == 0) 715 cp = sshkey_alg_list(0, 0, 0, '\n'); 716 else if (strcmp(optarg, "key-cert") == 0) 717 cp = sshkey_alg_list(1, 0, 0, '\n'); 718 else if (strcmp(optarg, "key-plain") == 0) 719 cp = sshkey_alg_list(0, 1, 0, '\n'); 720 else if (strcmp(optarg, "sig") == 0) 721 cp = sshkey_alg_list(0, 1, 1, '\n'); 722 else if (strcmp(optarg, "protocol-version") == 0) 723 cp = xstrdup("2"); 724 else if (strcmp(optarg, "help") == 0) { 725 cp = xstrdup( 726 "cipher\ncipher-auth\nkex\nkey\n" 727 "key-cert\nkey-plain\nmac\n" 728 "protocol-version\nsig"); 729 } 730 if (cp == NULL) 731 fatal("Unsupported query \"%s\"", optarg); 732 printf("%s\n", cp); 733 free(cp); 734 exit(0); 735 break; 736 case 'a': 737 options.forward_agent = 0; 738 break; 739 case 'A': 740 options.forward_agent = 1; 741 break; 742 case 'k': 743 options.gss_deleg_creds = 0; 744 break; 745 case 'K': 746 options.gss_authentication = 1; 747 options.gss_deleg_creds = 1; 748 break; 749 case 'i': 750 p = tilde_expand_filename(optarg, getuid()); 751 if (stat(p, &st) < 0) 752 fprintf(stderr, "Warning: Identity file %s " 753 "not accessible: %s.\n", p, 754 strerror(errno)); 755 else 756 add_identity_file(&options, NULL, p, 1); 757 free(p); 758 break; 759 case 'I': 760 #ifdef ENABLE_PKCS11 761 free(options.pkcs11_provider); 762 options.pkcs11_provider = xstrdup(optarg); 763 #else 764 fprintf(stderr, "no support for PKCS#11.\n"); 765 #endif 766 break; 767 case 'J': 768 if (options.jump_host != NULL) 769 fatal("Only a single -J option permitted"); 770 if (options.proxy_command != NULL) 771 fatal("Cannot specify -J with ProxyCommand"); 772 if (parse_jump(optarg, &options, 1) == -1) 773 fatal("Invalid -J argument"); 774 options.proxy_command = xstrdup("none"); 775 break; 776 case 't': 777 if (options.request_tty == REQUEST_TTY_YES) 778 options.request_tty = REQUEST_TTY_FORCE; 779 else 780 options.request_tty = REQUEST_TTY_YES; 781 break; 782 case 'v': 783 if (debug_flag == 0) { 784 debug_flag = 1; 785 options.log_level = SYSLOG_LEVEL_DEBUG1; 786 } else { 787 if (options.log_level < SYSLOG_LEVEL_DEBUG3) { 788 debug_flag++; 789 options.log_level++; 790 } 791 } 792 break; 793 case 'V': 794 fprintf(stderr, "%s, %s\n", 795 SSH_VERSION, 796 #ifdef WITH_OPENSSL 797 OpenSSL_version(OPENSSL_VERSION) 798 #else 799 "without OpenSSL" 800 #endif 801 ); 802 if (opt == 'V') 803 exit(0); 804 break; 805 case 'w': 806 if (options.tun_open == -1) 807 options.tun_open = SSH_TUNMODE_DEFAULT; 808 options.tun_local = a2tun(optarg, &options.tun_remote); 809 if (options.tun_local == SSH_TUNID_ERR) { 810 fprintf(stderr, 811 "Bad tun device '%s'\n", optarg); 812 exit(255); 813 } 814 break; 815 case 'W': 816 if (options.stdio_forward_host != NULL) 817 fatal("stdio forward already specified"); 818 if (muxclient_command != 0) 819 fatal("Cannot specify stdio forward with -O"); 820 if (parse_forward(&fwd, optarg, 1, 0)) { 821 options.stdio_forward_host = fwd.listen_host; 822 options.stdio_forward_port = fwd.listen_port; 823 free(fwd.connect_host); 824 } else { 825 fprintf(stderr, 826 "Bad stdio forwarding specification '%s'\n", 827 optarg); 828 exit(255); 829 } 830 options.request_tty = REQUEST_TTY_NO; 831 no_shell_flag = 1; 832 break; 833 case 'q': 834 options.log_level = SYSLOG_LEVEL_QUIET; 835 break; 836 case 'e': 837 if (optarg[0] == '^' && optarg[2] == 0 && 838 (u_char) optarg[1] >= 64 && 839 (u_char) optarg[1] < 128) 840 options.escape_char = (u_char) optarg[1] & 31; 841 else if (strlen(optarg) == 1) 842 options.escape_char = (u_char) optarg[0]; 843 else if (strcmp(optarg, "none") == 0) 844 options.escape_char = SSH_ESCAPECHAR_NONE; 845 else { 846 fprintf(stderr, "Bad escape character '%s'.\n", 847 optarg); 848 exit(255); 849 } 850 break; 851 case 'c': 852 if (!ciphers_valid(*optarg == '+' ? 853 optarg + 1 : optarg)) { 854 fprintf(stderr, "Unknown cipher type '%s'\n", 855 optarg); 856 exit(255); 857 } 858 free(options.ciphers); 859 options.ciphers = xstrdup(optarg); 860 break; 861 case 'm': 862 if (mac_valid(optarg)) { 863 free(options.macs); 864 options.macs = xstrdup(optarg); 865 } else { 866 fprintf(stderr, "Unknown mac type '%s'\n", 867 optarg); 868 exit(255); 869 } 870 break; 871 case 'M': 872 if (options.control_master == SSHCTL_MASTER_YES) 873 options.control_master = SSHCTL_MASTER_ASK; 874 else 875 options.control_master = SSHCTL_MASTER_YES; 876 break; 877 case 'p': 878 if (options.port == -1) { 879 options.port = a2port(optarg); 880 if (options.port <= 0) { 881 fprintf(stderr, "Bad port '%s'\n", 882 optarg); 883 exit(255); 884 } 885 } 886 break; 887 case 'l': 888 if (options.user == NULL) 889 options.user = optarg; 890 break; 891 892 case 'L': 893 if (parse_forward(&fwd, optarg, 0, 0)) 894 add_local_forward(&options, &fwd); 895 else { 896 fprintf(stderr, 897 "Bad local forwarding specification '%s'\n", 898 optarg); 899 exit(255); 900 } 901 break; 902 903 case 'R': 904 if (parse_forward(&fwd, optarg, 0, 1) || 905 parse_forward(&fwd, optarg, 1, 1)) { 906 add_remote_forward(&options, &fwd); 907 } else { 908 fprintf(stderr, 909 "Bad remote forwarding specification " 910 "'%s'\n", optarg); 911 exit(255); 912 } 913 break; 914 915 case 'D': 916 if (parse_forward(&fwd, optarg, 1, 0)) { 917 add_local_forward(&options, &fwd); 918 } else { 919 fprintf(stderr, 920 "Bad dynamic forwarding specification " 921 "'%s'\n", optarg); 922 exit(255); 923 } 924 break; 925 926 case 'C': 927 options.compression = 1; 928 break; 929 case 'N': 930 no_shell_flag = 1; 931 options.request_tty = REQUEST_TTY_NO; 932 break; 933 case 'T': 934 options.request_tty = REQUEST_TTY_NO; 935 break; 936 case 'o': 937 line = xstrdup(optarg); 938 if (process_config_line(&options, pw, 939 host ? host : "", host ? host : "", line, 940 "command-line", 0, NULL, SSHCONF_USERCONF) != 0) 941 exit(255); 942 free(line); 943 break; 944 case 's': 945 subsystem_flag = 1; 946 break; 947 case 'S': 948 free(options.control_path); 949 options.control_path = xstrdup(optarg); 950 break; 951 case 'b': 952 options.bind_address = optarg; 953 break; 954 case 'B': 955 options.bind_interface = optarg; 956 break; 957 case 'F': 958 config = optarg; 959 break; 960 default: 961 usage(); 962 } 963 } 964 965 if (optind > 1 && strcmp(av[optind - 1], "--") == 0) 966 opt_terminated = 1; 967 968 ac -= optind; 969 av += optind; 970 971 if (ac > 0 && !host) { 972 int tport; 973 char *tuser; 974 switch (parse_ssh_uri(*av, &tuser, &host, &tport)) { 975 case -1: 976 usage(); 977 break; 978 case 0: 979 if (options.user == NULL) { 980 options.user = tuser; 981 tuser = NULL; 982 } 983 free(tuser); 984 if (options.port == -1 && tport != -1) 985 options.port = tport; 986 break; 987 default: 988 p = xstrdup(*av); 989 cp = strrchr(p, '@'); 990 if (cp != NULL) { 991 if (cp == p) 992 usage(); 993 if (options.user == NULL) { 994 options.user = p; 995 p = NULL; 996 } 997 *cp++ = '\0'; 998 host = xstrdup(cp); 999 free(p); 1000 } else 1001 host = p; 1002 break; 1003 } 1004 if (ac > 1 && !opt_terminated) { 1005 optind = optreset = 1; 1006 goto again; 1007 } 1008 ac--, av++; 1009 } 1010 1011 /* Check that we got a host name. */ 1012 if (!host) 1013 usage(); 1014 1015 host_arg = xstrdup(host); 1016 1017 #ifdef WITH_OPENSSL 1018 OpenSSL_add_all_algorithms(); 1019 ERR_load_crypto_strings(); 1020 #endif 1021 1022 /* Initialize the command to execute on remote host. */ 1023 if ((command = sshbuf_new()) == NULL) 1024 fatal("sshbuf_new failed"); 1025 1026 /* 1027 * Save the command to execute on the remote host in a buffer. There 1028 * is no limit on the length of the command, except by the maximum 1029 * packet size. Also sets the tty flag if there is no command. 1030 */ 1031 if (!ac) { 1032 /* No command specified - execute shell on a tty. */ 1033 if (subsystem_flag) { 1034 fprintf(stderr, 1035 "You must specify a subsystem to invoke.\n"); 1036 usage(); 1037 } 1038 } else { 1039 /* A command has been specified. Store it into the buffer. */ 1040 for (i = 0; i < ac; i++) { 1041 if ((r = sshbuf_putf(command, "%s%s", 1042 i ? " " : "", av[i])) != 0) 1043 fatal("%s: buffer error: %s", 1044 __func__, ssh_err(r)); 1045 } 1046 } 1047 1048 /* 1049 * Initialize "log" output. Since we are the client all output 1050 * goes to stderr unless otherwise specified by -y or -E. 1051 */ 1052 if (use_syslog && logfile != NULL) 1053 fatal("Can't specify both -y and -E"); 1054 if (logfile != NULL) 1055 log_redirect_stderr_to(logfile); 1056 log_init(argv0, 1057 options.log_level == SYSLOG_LEVEL_NOT_SET ? 1058 SYSLOG_LEVEL_INFO : options.log_level, 1059 options.log_facility == SYSLOG_FACILITY_NOT_SET ? 1060 SYSLOG_FACILITY_USER : options.log_facility, 1061 !use_syslog); 1062 1063 if (debug_flag) 1064 logit("%s, %s", SSH_VERSION, 1065 #ifdef WITH_OPENSSL 1066 OpenSSL_version(OPENSSL_VERSION) 1067 #else 1068 "without OpenSSL" 1069 #endif 1070 ); 1071 1072 /* Parse the configuration files */ 1073 process_config_files(host_arg, pw, 0, &want_final_pass); 1074 if (want_final_pass) 1075 debug("configuration requests final Match pass"); 1076 1077 /* Hostname canonicalisation needs a few options filled. */ 1078 fill_default_options_for_canonicalization(&options); 1079 1080 /* If the user has replaced the hostname then take it into use now */ 1081 if (options.hostname != NULL) { 1082 /* NB. Please keep in sync with readconf.c:match_cfg_line() */ 1083 cp = percent_expand(options.hostname, 1084 "h", host, (char *)NULL); 1085 free(host); 1086 host = cp; 1087 free(options.hostname); 1088 options.hostname = xstrdup(host); 1089 } 1090 1091 /* Don't lowercase addresses, they will be explicitly canonicalised */ 1092 if ((was_addr = is_addr(host)) == 0) 1093 lowercase(host); 1094 1095 /* 1096 * Try to canonicalize if requested by configuration or the 1097 * hostname is an address. 1098 */ 1099 if (options.canonicalize_hostname != SSH_CANONICALISE_NO || was_addr) 1100 addrs = resolve_canonicalize(&host, options.port); 1101 1102 /* 1103 * If CanonicalizePermittedCNAMEs have been specified but 1104 * other canonicalization did not happen (by not being requested 1105 * or by failing with fallback) then the hostname may still be changed 1106 * as a result of CNAME following. 1107 * 1108 * Try to resolve the bare hostname name using the system resolver's 1109 * usual search rules and then apply the CNAME follow rules. 1110 * 1111 * Skip the lookup if a ProxyCommand is being used unless the user 1112 * has specifically requested canonicalisation for this case via 1113 * CanonicalizeHostname=always 1114 */ 1115 direct = option_clear_or_none(options.proxy_command) && 1116 options.jump_host == NULL; 1117 if (addrs == NULL && options.num_permitted_cnames != 0 && (direct || 1118 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { 1119 if ((addrs = resolve_host(host, options.port, 1120 direct, cname, sizeof(cname))) == NULL) { 1121 /* Don't fatal proxied host names not in the DNS */ 1122 if (direct) 1123 cleanup_exit(255); /* logged in resolve_host */ 1124 } else 1125 check_follow_cname(direct, &host, cname); 1126 } 1127 1128 /* 1129 * If canonicalisation is enabled then re-parse the configuration 1130 * files as new stanzas may match. 1131 */ 1132 if (options.canonicalize_hostname != 0 && !want_final_pass) { 1133 debug("hostname canonicalisation enabled, " 1134 "will re-parse configuration"); 1135 want_final_pass = 1; 1136 } 1137 1138 if (want_final_pass) { 1139 debug("re-parsing configuration"); 1140 free(options.hostname); 1141 options.hostname = xstrdup(host); 1142 process_config_files(host_arg, pw, 1, NULL); 1143 /* 1144 * Address resolution happens early with canonicalisation 1145 * enabled and the port number may have changed since, so 1146 * reset it in address list 1147 */ 1148 if (addrs != NULL && options.port > 0) 1149 set_addrinfo_port(addrs, options.port); 1150 } 1151 1152 /* Fill configuration defaults. */ 1153 fill_default_options(&options); 1154 1155 /* 1156 * If ProxyJump option specified, then construct a ProxyCommand now. 1157 */ 1158 if (options.jump_host != NULL) { 1159 char port_s[8]; 1160 const char *sshbin = argv0; 1161 1162 /* 1163 * Try to use SSH indicated by argv[0], but fall back to 1164 * "ssh" if it appears unavailable. 1165 */ 1166 if (strchr(argv0, '/') != NULL && access(argv0, X_OK) != 0) 1167 sshbin = "ssh"; 1168 1169 /* Consistency check */ 1170 if (options.proxy_command != NULL) 1171 fatal("inconsistent options: ProxyCommand+ProxyJump"); 1172 /* Never use FD passing for ProxyJump */ 1173 options.proxy_use_fdpass = 0; 1174 snprintf(port_s, sizeof(port_s), "%d", options.jump_port); 1175 xasprintf(&options.proxy_command, 1176 "%s%s%s%s%s%s%s%s%s%s%.*s -W '[%%h]:%%p' %s", 1177 sshbin, 1178 /* Optional "-l user" argument if jump_user set */ 1179 options.jump_user == NULL ? "" : " -l ", 1180 options.jump_user == NULL ? "" : options.jump_user, 1181 /* Optional "-p port" argument if jump_port set */ 1182 options.jump_port <= 0 ? "" : " -p ", 1183 options.jump_port <= 0 ? "" : port_s, 1184 /* Optional additional jump hosts ",..." */ 1185 options.jump_extra == NULL ? "" : " -J ", 1186 options.jump_extra == NULL ? "" : options.jump_extra, 1187 /* Optional "-F" argumment if -F specified */ 1188 config == NULL ? "" : " -F ", 1189 config == NULL ? "" : config, 1190 /* Optional "-v" arguments if -v set */ 1191 debug_flag ? " -" : "", 1192 debug_flag, "vvv", 1193 /* Mandatory hostname */ 1194 options.jump_host); 1195 debug("Setting implicit ProxyCommand from ProxyJump: %s", 1196 options.proxy_command); 1197 } 1198 1199 if (options.port == 0) 1200 options.port = default_ssh_port(); 1201 channel_set_af(ssh, options.address_family); 1202 1203 /* Tidy and check options */ 1204 if (options.host_key_alias != NULL) 1205 lowercase(options.host_key_alias); 1206 if (options.proxy_command != NULL && 1207 strcmp(options.proxy_command, "-") == 0 && 1208 options.proxy_use_fdpass) 1209 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); 1210 if (options.control_persist && 1211 options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 1212 debug("UpdateHostKeys=ask is incompatible with ControlPersist; " 1213 "disabling"); 1214 options.update_hostkeys = 0; 1215 } 1216 if (options.connection_attempts <= 0) 1217 fatal("Invalid number of ConnectionAttempts"); 1218 1219 if (sshbuf_len(command) != 0 && options.remote_command != NULL) 1220 fatal("Cannot execute command-line and remote command."); 1221 1222 /* Cannot fork to background if no command. */ 1223 if (fork_after_authentication_flag && sshbuf_len(command) == 0 && 1224 options.remote_command == NULL && !no_shell_flag) 1225 fatal("Cannot fork into background without a command " 1226 "to execute."); 1227 1228 /* reinit */ 1229 log_init(argv0, options.log_level, options.log_facility, !use_syslog); 1230 1231 if (options.request_tty == REQUEST_TTY_YES || 1232 options.request_tty == REQUEST_TTY_FORCE) 1233 tty_flag = 1; 1234 1235 /* Allocate a tty by default if no command specified. */ 1236 if (sshbuf_len(command) == 0 && options.remote_command == NULL) 1237 tty_flag = options.request_tty != REQUEST_TTY_NO; 1238 1239 /* Force no tty */ 1240 if (options.request_tty == REQUEST_TTY_NO || 1241 (muxclient_command && muxclient_command != SSHMUX_COMMAND_PROXY)) 1242 tty_flag = 0; 1243 /* Do not allocate a tty if stdin is not a tty. */ 1244 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 1245 options.request_tty != REQUEST_TTY_FORCE) { 1246 if (tty_flag) 1247 logit("Pseudo-terminal will not be allocated because " 1248 "stdin is not a terminal."); 1249 tty_flag = 0; 1250 } 1251 1252 if (options.user == NULL) 1253 options.user = xstrdup(pw->pw_name); 1254 1255 /* Set up strings used to percent_expand() arguments */ 1256 if (gethostname(thishost, sizeof(thishost)) == -1) 1257 fatal("gethostname: %s", strerror(errno)); 1258 strlcpy(shorthost, thishost, sizeof(shorthost)); 1259 shorthost[strcspn(thishost, ".")] = '\0'; 1260 snprintf(portstr, sizeof(portstr), "%d", options.port); 1261 snprintf(uidstr, sizeof(uidstr), "%llu", 1262 (unsigned long long)pw->pw_uid); 1263 1264 if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL || 1265 ssh_digest_update(md, thishost, strlen(thishost)) < 0 || 1266 ssh_digest_update(md, host, strlen(host)) < 0 || 1267 ssh_digest_update(md, portstr, strlen(portstr)) < 0 || 1268 ssh_digest_update(md, options.user, strlen(options.user)) < 0 || 1269 ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0) 1270 fatal("%s: mux digest failed", __func__); 1271 ssh_digest_free(md); 1272 conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1)); 1273 1274 /* 1275 * Expand tokens in arguments. NB. LocalCommand is expanded later, 1276 * after port-forwarding is set up, so it may pick up any local 1277 * tunnel interface name allocated. 1278 */ 1279 if (options.remote_command != NULL) { 1280 debug3("expanding RemoteCommand: %s", options.remote_command); 1281 cp = options.remote_command; 1282 options.remote_command = percent_expand(cp, 1283 "C", conn_hash_hex, 1284 "L", shorthost, 1285 "d", pw->pw_dir, 1286 "h", host, 1287 "i", uidstr, 1288 "l", thishost, 1289 "n", host_arg, 1290 "p", portstr, 1291 "r", options.user, 1292 "u", pw->pw_name, 1293 (char *)NULL); 1294 debug3("expanded RemoteCommand: %s", options.remote_command); 1295 free(cp); 1296 if ((r = sshbuf_put(command, options.remote_command, 1297 strlen(options.remote_command))) != 0) 1298 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1299 } 1300 1301 if (options.control_path != NULL) { 1302 cp = tilde_expand_filename(options.control_path, getuid()); 1303 free(options.control_path); 1304 options.control_path = percent_expand(cp, 1305 "C", conn_hash_hex, 1306 "L", shorthost, 1307 "h", host, 1308 "i", uidstr, 1309 "l", thishost, 1310 "n", host_arg, 1311 "p", portstr, 1312 "r", options.user, 1313 "u", pw->pw_name, 1314 "i", uidstr, 1315 (char *)NULL); 1316 free(cp); 1317 } 1318 1319 if (config_test) { 1320 dump_client_config(&options, host); 1321 exit(0); 1322 } 1323 1324 if (muxclient_command != 0 && options.control_path == NULL) 1325 fatal("No ControlPath specified for \"-O\" command"); 1326 if (options.control_path != NULL) { 1327 int sock; 1328 if ((sock = muxclient(options.control_path)) >= 0) { 1329 ssh_packet_set_connection(ssh, sock, sock); 1330 ssh_packet_set_mux(ssh); 1331 goto skip_connect; 1332 } 1333 } 1334 1335 /* 1336 * If hostname canonicalisation was not enabled, then we may not 1337 * have yet resolved the hostname. Do so now. 1338 */ 1339 if (addrs == NULL && options.proxy_command == NULL) { 1340 debug2("resolving \"%s\" port %d", host, options.port); 1341 if ((addrs = resolve_host(host, options.port, 1, 1342 cname, sizeof(cname))) == NULL) 1343 cleanup_exit(255); /* resolve_host logs the error */ 1344 } 1345 1346 timeout_ms = options.connection_timeout * 1000; 1347 1348 /* Open a connection to the remote host. */ 1349 if (ssh_connect(ssh, host, addrs, &hostaddr, options.port, 1350 options.address_family, options.connection_attempts, 1351 &timeout_ms, options.tcp_keep_alive) != 0) 1352 exit(255); 1353 1354 if (addrs != NULL) 1355 freeaddrinfo(addrs); 1356 1357 ssh_packet_set_timeout(ssh, options.server_alive_interval, 1358 options.server_alive_count_max); 1359 1360 if (timeout_ms > 0) 1361 debug3("timeout: %d ms remain after connect", timeout_ms); 1362 1363 /* 1364 * If we successfully made the connection and we have hostbased auth 1365 * enabled, load the public keys so we can later use the ssh-keysign 1366 * helper to sign challenges. 1367 */ 1368 sensitive_data.nkeys = 0; 1369 sensitive_data.keys = NULL; 1370 if (options.hostbased_authentication) { 1371 sensitive_data.nkeys = 10; 1372 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 1373 sizeof(struct sshkey)); 1374 1375 /* XXX check errors? */ 1376 #define L_PUBKEY(p,o) do { \ 1377 if ((o) >= sensitive_data.nkeys) \ 1378 fatal("%s pubkey out of array bounds", __func__); \ 1379 check_load(sshkey_load_public(p, &(sensitive_data.keys[o]), NULL), \ 1380 p, "pubkey"); \ 1381 } while (0) 1382 #define L_CERT(p,o) do { \ 1383 if ((o) >= sensitive_data.nkeys) \ 1384 fatal("%s cert out of array bounds", __func__); \ 1385 check_load(sshkey_load_cert(p, &(sensitive_data.keys[o])), p, "cert"); \ 1386 } while (0) 1387 1388 if (options.hostbased_authentication == 1) { 1389 L_CERT(_PATH_HOST_ECDSA_KEY_FILE, 0); 1390 L_CERT(_PATH_HOST_ED25519_KEY_FILE, 1); 1391 L_CERT(_PATH_HOST_RSA_KEY_FILE, 2); 1392 L_CERT(_PATH_HOST_DSA_KEY_FILE, 3); 1393 L_PUBKEY(_PATH_HOST_ECDSA_KEY_FILE, 4); 1394 L_PUBKEY(_PATH_HOST_ED25519_KEY_FILE, 5); 1395 L_PUBKEY(_PATH_HOST_RSA_KEY_FILE, 6); 1396 L_PUBKEY(_PATH_HOST_DSA_KEY_FILE, 7); 1397 L_CERT(_PATH_HOST_XMSS_KEY_FILE, 8); 1398 L_PUBKEY(_PATH_HOST_XMSS_KEY_FILE, 9); 1399 } 1400 } 1401 1402 /* Create ~/.ssh * directory if it doesn't already exist. */ 1403 if (config == NULL) { 1404 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 1405 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 1406 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) 1407 if (mkdir(buf, 0700) < 0) 1408 error("Could not create directory '%.200s'.", 1409 buf); 1410 } 1411 1412 /* load options.identity_files */ 1413 load_public_identity_files(pw); 1414 1415 /* optionally set the SSH_AUTHSOCKET_ENV_NAME variable */ 1416 if (options.identity_agent && 1417 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) { 1418 if (strcmp(options.identity_agent, "none") == 0) { 1419 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1420 } else { 1421 p = tilde_expand_filename(options.identity_agent, 1422 getuid()); 1423 cp = percent_expand(p, 1424 "d", pw->pw_dir, 1425 "h", host, 1426 "i", uidstr, 1427 "l", thishost, 1428 "r", options.user, 1429 "u", pw->pw_name, 1430 (char *)NULL); 1431 free(p); 1432 /* 1433 * If identity_agent represents an environment variable 1434 * then recheck that it is valid (since processing with 1435 * percent_expand() may have changed it) and substitute 1436 * its value. 1437 */ 1438 if (cp[0] == '$') { 1439 if (!valid_env_name(cp + 1)) { 1440 fatal("Invalid IdentityAgent " 1441 "environment variable name %s", cp); 1442 } 1443 if ((p = getenv(cp + 1)) == NULL) 1444 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1445 else 1446 setenv(SSH_AUTHSOCKET_ENV_NAME, p, 1); 1447 } else { 1448 /* identity_agent specifies a path directly */ 1449 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1); 1450 } 1451 free(cp); 1452 } 1453 } 1454 1455 /* Expand ~ in known host file names. */ 1456 tilde_expand_paths(options.system_hostfiles, 1457 options.num_system_hostfiles); 1458 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 1459 1460 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 1461 signal(SIGCHLD, main_sigchld_handler); 1462 1463 /* Log into the remote system. Never returns if the login fails. */ 1464 ssh_login(ssh, &sensitive_data, host, (struct sockaddr *)&hostaddr, 1465 options.port, pw, timeout_ms); 1466 1467 if (ssh_packet_connection_is_on_socket(ssh)) { 1468 verbose("Authenticated to %s ([%s]:%d).", host, 1469 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); 1470 } else { 1471 verbose("Authenticated to %s (via proxy).", host); 1472 } 1473 1474 /* We no longer need the private host keys. Clear them now. */ 1475 if (sensitive_data.nkeys != 0) { 1476 for (i = 0; i < sensitive_data.nkeys; i++) { 1477 if (sensitive_data.keys[i] != NULL) { 1478 /* Destroys contents safely */ 1479 debug3("clear hostkey %d", i); 1480 sshkey_free(sensitive_data.keys[i]); 1481 sensitive_data.keys[i] = NULL; 1482 } 1483 } 1484 free(sensitive_data.keys); 1485 } 1486 for (i = 0; i < options.num_identity_files; i++) { 1487 free(options.identity_files[i]); 1488 options.identity_files[i] = NULL; 1489 if (options.identity_keys[i]) { 1490 sshkey_free(options.identity_keys[i]); 1491 options.identity_keys[i] = NULL; 1492 } 1493 } 1494 for (i = 0; i < options.num_certificate_files; i++) { 1495 free(options.certificate_files[i]); 1496 options.certificate_files[i] = NULL; 1497 } 1498 1499 skip_connect: 1500 exit_status = ssh_session2(ssh, pw); 1501 ssh_packet_close(ssh); 1502 1503 if (options.control_path != NULL && muxserver_sock != -1) 1504 unlink(options.control_path); 1505 1506 /* Kill ProxyCommand if it is running. */ 1507 ssh_kill_proxy_command(); 1508 1509 return exit_status; 1510 } 1511 1512 static void 1513 control_persist_detach(void) 1514 { 1515 pid_t pid; 1516 int devnull, keep_stderr; 1517 1518 debug("%s: backgrounding master process", __func__); 1519 1520 /* 1521 * master (current process) into the background, and make the 1522 * foreground process a client of the backgrounded master. 1523 */ 1524 switch ((pid = fork())) { 1525 case -1: 1526 fatal("%s: fork: %s", __func__, strerror(errno)); 1527 case 0: 1528 /* Child: master process continues mainloop */ 1529 break; 1530 default: 1531 /* Parent: set up mux slave to connect to backgrounded master */ 1532 debug2("%s: background process is %ld", __func__, (long)pid); 1533 stdin_null_flag = ostdin_null_flag; 1534 options.request_tty = orequest_tty; 1535 tty_flag = otty_flag; 1536 close(muxserver_sock); 1537 muxserver_sock = -1; 1538 options.control_master = SSHCTL_MASTER_NO; 1539 muxclient(options.control_path); 1540 /* muxclient() doesn't return on success. */ 1541 fatal("Failed to connect to new control master"); 1542 } 1543 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1544 error("%s: open(\"/dev/null\"): %s", __func__, 1545 strerror(errno)); 1546 } else { 1547 keep_stderr = log_is_on_stderr() && debug_flag; 1548 if (dup2(devnull, STDIN_FILENO) == -1 || 1549 dup2(devnull, STDOUT_FILENO) == -1 || 1550 (!keep_stderr && dup2(devnull, STDERR_FILENO) == -1)) 1551 error("%s: dup2: %s", __func__, strerror(errno)); 1552 if (devnull > STDERR_FILENO) 1553 close(devnull); 1554 } 1555 daemon(1, 1); 1556 setproctitle("%s [mux]", options.control_path); 1557 } 1558 1559 /* Do fork() after authentication. Used by "ssh -f" */ 1560 static void 1561 fork_postauth(void) 1562 { 1563 if (need_controlpersist_detach) 1564 control_persist_detach(); 1565 debug("forking to background"); 1566 fork_after_authentication_flag = 0; 1567 if (daemon(1, 1) < 0) 1568 fatal("daemon() failed: %.200s", strerror(errno)); 1569 } 1570 1571 /* Callback for remote forward global requests */ 1572 static void 1573 ssh_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt) 1574 { 1575 struct Forward *rfwd = (struct Forward *)ctxt; 1576 u_int port; 1577 int r; 1578 1579 /* XXX verbose() on failure? */ 1580 debug("remote forward %s for: listen %s%s%d, connect %s:%d", 1581 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1582 rfwd->listen_path ? rfwd->listen_path : 1583 rfwd->listen_host ? rfwd->listen_host : "", 1584 (rfwd->listen_path || rfwd->listen_host) ? ":" : "", 1585 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path : 1586 rfwd->connect_host, rfwd->connect_port); 1587 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) { 1588 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1589 if ((r = sshpkt_get_u32(ssh, &port)) != 0) 1590 fatal("%s: %s", __func__, ssh_err(r)); 1591 if (port > 65535) { 1592 error("Invalid allocated port %u for remote " 1593 "forward to %s:%d", port, 1594 rfwd->connect_host, rfwd->connect_port); 1595 /* Ensure failure processing runs below */ 1596 type = SSH2_MSG_REQUEST_FAILURE; 1597 channel_update_permission(ssh, 1598 rfwd->handle, -1); 1599 } else { 1600 rfwd->allocated_port = (int)port; 1601 logit("Allocated port %u for remote " 1602 "forward to %s:%d", 1603 rfwd->allocated_port, rfwd->connect_host, 1604 rfwd->connect_port); 1605 channel_update_permission(ssh, 1606 rfwd->handle, rfwd->allocated_port); 1607 } 1608 } else { 1609 channel_update_permission(ssh, rfwd->handle, -1); 1610 } 1611 } 1612 1613 if (type == SSH2_MSG_REQUEST_FAILURE) { 1614 if (options.exit_on_forward_failure) { 1615 if (rfwd->listen_path != NULL) 1616 fatal("Error: remote port forwarding failed " 1617 "for listen path %s", rfwd->listen_path); 1618 else 1619 fatal("Error: remote port forwarding failed " 1620 "for listen port %d", rfwd->listen_port); 1621 } else { 1622 if (rfwd->listen_path != NULL) 1623 logit("Warning: remote port forwarding failed " 1624 "for listen path %s", rfwd->listen_path); 1625 else 1626 logit("Warning: remote port forwarding failed " 1627 "for listen port %d", rfwd->listen_port); 1628 } 1629 } 1630 if (++remote_forward_confirms_received == options.num_remote_forwards) { 1631 debug("All remote forwarding requests processed"); 1632 if (fork_after_authentication_flag) 1633 fork_postauth(); 1634 } 1635 } 1636 1637 static void 1638 client_cleanup_stdio_fwd(struct ssh *ssh, int id, void *arg) 1639 { 1640 debug("stdio forwarding: done"); 1641 cleanup_exit(0); 1642 } 1643 1644 static void 1645 ssh_stdio_confirm(struct ssh *ssh, int id, int success, void *arg) 1646 { 1647 if (!success) 1648 fatal("stdio forwarding failed"); 1649 } 1650 1651 static void 1652 ssh_init_stdio_forwarding(struct ssh *ssh) 1653 { 1654 Channel *c; 1655 int in, out; 1656 1657 if (options.stdio_forward_host == NULL) 1658 return; 1659 1660 debug3("%s: %s:%d", __func__, options.stdio_forward_host, 1661 options.stdio_forward_port); 1662 1663 if ((in = dup(STDIN_FILENO)) < 0 || 1664 (out = dup(STDOUT_FILENO)) < 0) 1665 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1666 if ((c = channel_connect_stdio_fwd(ssh, options.stdio_forward_host, 1667 options.stdio_forward_port, in, out)) == NULL) 1668 fatal("%s: channel_connect_stdio_fwd failed", __func__); 1669 channel_register_cleanup(ssh, c->self, client_cleanup_stdio_fwd, 0); 1670 channel_register_open_confirm(ssh, c->self, ssh_stdio_confirm, NULL); 1671 } 1672 1673 static void 1674 ssh_init_forwarding(struct ssh *ssh, char **ifname) 1675 { 1676 int success = 0; 1677 int i; 1678 1679 /* Initiate local TCP/IP port forwardings. */ 1680 for (i = 0; i < options.num_local_forwards; i++) { 1681 debug("Local connections to %.200s:%d forwarded to remote " 1682 "address %.200s:%d", 1683 (options.local_forwards[i].listen_path != NULL) ? 1684 options.local_forwards[i].listen_path : 1685 (options.local_forwards[i].listen_host == NULL) ? 1686 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") : 1687 options.local_forwards[i].listen_host, 1688 options.local_forwards[i].listen_port, 1689 (options.local_forwards[i].connect_path != NULL) ? 1690 options.local_forwards[i].connect_path : 1691 options.local_forwards[i].connect_host, 1692 options.local_forwards[i].connect_port); 1693 success += channel_setup_local_fwd_listener(ssh, 1694 &options.local_forwards[i], &options.fwd_opts); 1695 } 1696 if (i > 0 && success != i && options.exit_on_forward_failure) 1697 fatal("Could not request local forwarding."); 1698 if (i > 0 && success == 0) 1699 error("Could not request local forwarding."); 1700 1701 /* Initiate remote TCP/IP port forwardings. */ 1702 for (i = 0; i < options.num_remote_forwards; i++) { 1703 debug("Remote connections from %.200s:%d forwarded to " 1704 "local address %.200s:%d", 1705 (options.remote_forwards[i].listen_path != NULL) ? 1706 options.remote_forwards[i].listen_path : 1707 (options.remote_forwards[i].listen_host == NULL) ? 1708 "LOCALHOST" : options.remote_forwards[i].listen_host, 1709 options.remote_forwards[i].listen_port, 1710 (options.remote_forwards[i].connect_path != NULL) ? 1711 options.remote_forwards[i].connect_path : 1712 options.remote_forwards[i].connect_host, 1713 options.remote_forwards[i].connect_port); 1714 options.remote_forwards[i].handle = 1715 channel_request_remote_forwarding(ssh, 1716 &options.remote_forwards[i]); 1717 if (options.remote_forwards[i].handle < 0) { 1718 if (options.exit_on_forward_failure) 1719 fatal("Could not request remote forwarding."); 1720 else 1721 logit("Warning: Could not request remote " 1722 "forwarding."); 1723 } else { 1724 client_register_global_confirm( 1725 ssh_confirm_remote_forward, 1726 &options.remote_forwards[i]); 1727 } 1728 } 1729 1730 /* Initiate tunnel forwarding. */ 1731 if (options.tun_open != SSH_TUNMODE_NO) { 1732 if ((*ifname = client_request_tun_fwd(ssh, 1733 options.tun_open, options.tun_local, 1734 options.tun_remote)) == NULL) { 1735 if (options.exit_on_forward_failure) 1736 fatal("Could not request tunnel forwarding."); 1737 else 1738 error("Could not request tunnel forwarding."); 1739 } 1740 } 1741 } 1742 1743 static void 1744 check_agent_present(void) 1745 { 1746 int r; 1747 1748 if (options.forward_agent) { 1749 /* Clear agent forwarding if we don't have an agent. */ 1750 if ((r = ssh_get_authentication_socket(NULL)) != 0) { 1751 options.forward_agent = 0; 1752 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1753 debug("ssh_get_authentication_socket: %s", 1754 ssh_err(r)); 1755 } 1756 } 1757 } 1758 1759 static void 1760 ssh_session2_setup(struct ssh *ssh, int id, int success, void *arg) 1761 { 1762 extern char **environ; 1763 const char *display; 1764 int r, interactive = tty_flag; 1765 char *proto = NULL, *data = NULL; 1766 1767 if (!success) 1768 return; /* No need for error message, channels code sens one */ 1769 1770 display = getenv("DISPLAY"); 1771 if (display == NULL && options.forward_x11) 1772 debug("X11 forwarding requested but DISPLAY not set"); 1773 if (options.forward_x11 && client_x11_get_proto(ssh, display, 1774 options.xauth_location, options.forward_x11_trusted, 1775 options.forward_x11_timeout, &proto, &data) == 0) { 1776 /* Request forwarding with authentication spoofing. */ 1777 debug("Requesting X11 forwarding with authentication " 1778 "spoofing."); 1779 x11_request_forwarding_with_spoofing(ssh, id, display, proto, 1780 data, 1); 1781 client_expect_confirm(ssh, id, "X11 forwarding", CONFIRM_WARN); 1782 /* XXX exit_on_forward_failure */ 1783 interactive = 1; 1784 } 1785 1786 check_agent_present(); 1787 if (options.forward_agent) { 1788 debug("Requesting authentication agent forwarding."); 1789 channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0); 1790 if ((r = sshpkt_send(ssh)) != 0) 1791 fatal("%s: %s", __func__, ssh_err(r)); 1792 } 1793 1794 /* Tell the packet module whether this is an interactive session. */ 1795 ssh_packet_set_interactive(ssh, interactive, 1796 options.ip_qos_interactive, options.ip_qos_bulk); 1797 1798 client_session2_setup(ssh, id, tty_flag, subsystem_flag, getenv("TERM"), 1799 NULL, fileno(stdin), command, environ); 1800 } 1801 1802 /* open new channel for a session */ 1803 static int 1804 ssh_session2_open(struct ssh *ssh) 1805 { 1806 Channel *c; 1807 int window, packetmax, in, out, err; 1808 1809 if (stdin_null_flag) { 1810 in = open(_PATH_DEVNULL, O_RDONLY); 1811 } else { 1812 in = dup(STDIN_FILENO); 1813 } 1814 out = dup(STDOUT_FILENO); 1815 err = dup(STDERR_FILENO); 1816 1817 if (in < 0 || out < 0 || err < 0) 1818 fatal("dup() in/out/err failed"); 1819 1820 /* enable nonblocking unless tty */ 1821 if (!isatty(in)) 1822 set_nonblock(in); 1823 if (!isatty(out)) 1824 set_nonblock(out); 1825 if (!isatty(err)) 1826 set_nonblock(err); 1827 1828 window = CHAN_SES_WINDOW_DEFAULT; 1829 packetmax = CHAN_SES_PACKET_DEFAULT; 1830 if (tty_flag) { 1831 window >>= 1; 1832 packetmax >>= 1; 1833 } 1834 c = channel_new(ssh, 1835 "session", SSH_CHANNEL_OPENING, in, out, err, 1836 window, packetmax, CHAN_EXTENDED_WRITE, 1837 "client-session", /*nonblock*/0); 1838 1839 debug3("%s: channel_new: %d", __func__, c->self); 1840 1841 channel_send_open(ssh, c->self); 1842 if (!no_shell_flag) 1843 channel_register_open_confirm(ssh, c->self, 1844 ssh_session2_setup, NULL); 1845 1846 return c->self; 1847 } 1848 1849 static int 1850 ssh_session2(struct ssh *ssh, struct passwd *pw) 1851 { 1852 int r, devnull, id = -1; 1853 char *cp, *tun_fwd_ifname = NULL; 1854 1855 /* XXX should be pre-session */ 1856 if (!options.control_persist) 1857 ssh_init_stdio_forwarding(ssh); 1858 1859 ssh_init_forwarding(ssh, &tun_fwd_ifname); 1860 1861 if (options.local_command != NULL) { 1862 debug3("expanding LocalCommand: %s", options.local_command); 1863 cp = options.local_command; 1864 options.local_command = percent_expand(cp, 1865 "C", conn_hash_hex, 1866 "L", shorthost, 1867 "d", pw->pw_dir, 1868 "h", host, 1869 "i", uidstr, 1870 "l", thishost, 1871 "n", host_arg, 1872 "p", portstr, 1873 "r", options.user, 1874 "u", pw->pw_name, 1875 "T", tun_fwd_ifname == NULL ? "NONE" : tun_fwd_ifname, 1876 (char *)NULL); 1877 debug3("expanded LocalCommand: %s", options.local_command); 1878 free(cp); 1879 } 1880 1881 /* Start listening for multiplex clients */ 1882 if (!ssh_packet_get_mux(ssh)) 1883 muxserver_listen(ssh); 1884 1885 /* 1886 * If we are in control persist mode and have a working mux listen 1887 * socket, then prepare to background ourselves and have a foreground 1888 * client attach as a control slave. 1889 * NB. we must save copies of the flags that we override for 1890 * the backgrounding, since we defer attachment of the slave until 1891 * after the connection is fully established (in particular, 1892 * async rfwd replies have been received for ExitOnForwardFailure). 1893 */ 1894 if (options.control_persist && muxserver_sock != -1) { 1895 ostdin_null_flag = stdin_null_flag; 1896 ono_shell_flag = no_shell_flag; 1897 orequest_tty = options.request_tty; 1898 otty_flag = tty_flag; 1899 stdin_null_flag = 1; 1900 no_shell_flag = 1; 1901 tty_flag = 0; 1902 if (!fork_after_authentication_flag) 1903 need_controlpersist_detach = 1; 1904 fork_after_authentication_flag = 1; 1905 } 1906 /* 1907 * ControlPersist mux listen socket setup failed, attempt the 1908 * stdio forward setup that we skipped earlier. 1909 */ 1910 if (options.control_persist && muxserver_sock == -1) 1911 ssh_init_stdio_forwarding(ssh); 1912 1913 if (!no_shell_flag) 1914 id = ssh_session2_open(ssh); 1915 else { 1916 ssh_packet_set_interactive(ssh, 1917 options.control_master == SSHCTL_MASTER_NO, 1918 options.ip_qos_interactive, options.ip_qos_bulk); 1919 } 1920 1921 /* If we don't expect to open a new session, then disallow it */ 1922 if (options.control_master == SSHCTL_MASTER_NO && 1923 (datafellows & SSH_NEW_OPENSSH)) { 1924 debug("Requesting no-more-sessions@openssh.com"); 1925 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 1926 (r = sshpkt_put_cstring(ssh, 1927 "no-more-sessions@openssh.com")) != 0 || 1928 (r = sshpkt_put_u8(ssh, 0)) != 0 || 1929 (r = sshpkt_send(ssh)) != 0) 1930 fatal("%s: %s", __func__, ssh_err(r)); 1931 } 1932 1933 /* Execute a local command */ 1934 if (options.local_command != NULL && 1935 options.permit_local_command) 1936 ssh_local_cmd(options.local_command); 1937 1938 /* 1939 * stdout is now owned by the session channel; clobber it here 1940 * so future channel closes are propagated to the local fd. 1941 * NB. this can only happen after LocalCommand has completed, 1942 * as it may want to write to stdout. 1943 */ 1944 if (!need_controlpersist_detach) { 1945 if ((devnull = open(_PATH_DEVNULL, O_WRONLY)) == -1) 1946 error("%s: open %s: %s", __func__, 1947 _PATH_DEVNULL, strerror(errno)); 1948 if (dup2(devnull, STDOUT_FILENO) < 0) 1949 fatal("%s: dup2() stdout failed", __func__); 1950 if (devnull > STDERR_FILENO) 1951 close(devnull); 1952 } 1953 1954 /* 1955 * If requested and we are not interested in replies to remote 1956 * forwarding requests, then let ssh continue in the background. 1957 */ 1958 if (fork_after_authentication_flag) { 1959 if (options.exit_on_forward_failure && 1960 options.num_remote_forwards > 0) { 1961 debug("deferring postauth fork until remote forward " 1962 "confirmation received"); 1963 } else 1964 fork_postauth(); 1965 } 1966 1967 return client_loop(ssh, tty_flag, tty_flag ? 1968 options.escape_char : SSH_ESCAPECHAR_NONE, id); 1969 } 1970 1971 /* Loads all IdentityFile and CertificateFile keys */ 1972 static void 1973 load_public_identity_files(struct passwd *pw) 1974 { 1975 char *filename, *cp; 1976 struct sshkey *public; 1977 int i; 1978 u_int n_ids, n_certs; 1979 char *identity_files[SSH_MAX_IDENTITY_FILES]; 1980 struct sshkey *identity_keys[SSH_MAX_IDENTITY_FILES]; 1981 int identity_file_userprovided[SSH_MAX_IDENTITY_FILES]; 1982 char *certificate_files[SSH_MAX_CERTIFICATE_FILES]; 1983 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES]; 1984 int certificate_file_userprovided[SSH_MAX_CERTIFICATE_FILES]; 1985 #ifdef ENABLE_PKCS11 1986 struct sshkey **keys; 1987 int nkeys; 1988 #endif /* PKCS11 */ 1989 1990 n_ids = n_certs = 0; 1991 memset(identity_files, 0, sizeof(identity_files)); 1992 memset(identity_keys, 0, sizeof(identity_keys)); 1993 memset(identity_file_userprovided, 0, 1994 sizeof(identity_file_userprovided)); 1995 memset(certificate_files, 0, sizeof(certificate_files)); 1996 memset(certificates, 0, sizeof(certificates)); 1997 memset(certificate_file_userprovided, 0, 1998 sizeof(certificate_file_userprovided)); 1999 2000 #ifdef ENABLE_PKCS11 2001 if (options.pkcs11_provider != NULL && 2002 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 2003 (pkcs11_init(!options.batch_mode) == 0) && 2004 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 2005 &keys)) > 0) { 2006 for (i = 0; i < nkeys; i++) { 2007 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 2008 sshkey_free(keys[i]); 2009 continue; 2010 } 2011 identity_keys[n_ids] = keys[i]; 2012 identity_files[n_ids] = 2013 xstrdup(options.pkcs11_provider); /* XXX */ 2014 n_ids++; 2015 } 2016 free(keys); 2017 } 2018 #endif /* ENABLE_PKCS11 */ 2019 for (i = 0; i < options.num_identity_files; i++) { 2020 if (n_ids >= SSH_MAX_IDENTITY_FILES || 2021 strcasecmp(options.identity_files[i], "none") == 0) { 2022 free(options.identity_files[i]); 2023 options.identity_files[i] = NULL; 2024 continue; 2025 } 2026 cp = tilde_expand_filename(options.identity_files[i], getuid()); 2027 filename = percent_expand(cp, "d", pw->pw_dir, 2028 "u", pw->pw_name, "l", thishost, "h", host, 2029 "r", options.user, (char *)NULL); 2030 free(cp); 2031 check_load(sshkey_load_public(filename, &public, NULL), 2032 filename, "pubkey"); 2033 debug("identity file %s type %d", filename, 2034 public ? public->type : -1); 2035 free(options.identity_files[i]); 2036 identity_files[n_ids] = filename; 2037 identity_keys[n_ids] = public; 2038 identity_file_userprovided[n_ids] = 2039 options.identity_file_userprovided[i]; 2040 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 2041 continue; 2042 2043 /* 2044 * If no certificates have been explicitly listed then try 2045 * to add the default certificate variant too. 2046 */ 2047 if (options.num_certificate_files != 0) 2048 continue; 2049 xasprintf(&cp, "%s-cert", filename); 2050 check_load(sshkey_load_public(cp, &public, NULL), 2051 filename, "pubkey"); 2052 debug("identity file %s type %d", cp, 2053 public ? public->type : -1); 2054 if (public == NULL) { 2055 free(cp); 2056 continue; 2057 } 2058 if (!sshkey_is_cert(public)) { 2059 debug("%s: key %s type %s is not a certificate", 2060 __func__, cp, sshkey_type(public)); 2061 sshkey_free(public); 2062 free(cp); 2063 continue; 2064 } 2065 /* NB. leave filename pointing to private key */ 2066 identity_files[n_ids] = xstrdup(filename); 2067 identity_keys[n_ids] = public; 2068 identity_file_userprovided[n_ids] = 2069 options.identity_file_userprovided[i]; 2070 n_ids++; 2071 } 2072 2073 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES) 2074 fatal("%s: too many certificates", __func__); 2075 for (i = 0; i < options.num_certificate_files; i++) { 2076 cp = tilde_expand_filename(options.certificate_files[i], 2077 getuid()); 2078 filename = percent_expand(cp, 2079 "d", pw->pw_dir, 2080 "h", host, 2081 "i", uidstr, 2082 "l", thishost, 2083 "r", options.user, 2084 "u", pw->pw_name, 2085 (char *)NULL); 2086 free(cp); 2087 2088 check_load(sshkey_load_public(filename, &public, NULL), 2089 filename, "certificate"); 2090 debug("certificate file %s type %d", filename, 2091 public ? public->type : -1); 2092 free(options.certificate_files[i]); 2093 options.certificate_files[i] = NULL; 2094 if (public == NULL) { 2095 free(filename); 2096 continue; 2097 } 2098 if (!sshkey_is_cert(public)) { 2099 debug("%s: key %s type %s is not a certificate", 2100 __func__, filename, sshkey_type(public)); 2101 sshkey_free(public); 2102 free(filename); 2103 continue; 2104 } 2105 certificate_files[n_certs] = filename; 2106 certificates[n_certs] = public; 2107 certificate_file_userprovided[n_certs] = 2108 options.certificate_file_userprovided[i]; 2109 ++n_certs; 2110 } 2111 2112 options.num_identity_files = n_ids; 2113 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 2114 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 2115 memcpy(options.identity_file_userprovided, 2116 identity_file_userprovided, sizeof(identity_file_userprovided)); 2117 2118 options.num_certificate_files = n_certs; 2119 memcpy(options.certificate_files, 2120 certificate_files, sizeof(certificate_files)); 2121 memcpy(options.certificates, certificates, sizeof(certificates)); 2122 memcpy(options.certificate_file_userprovided, 2123 certificate_file_userprovided, 2124 sizeof(certificate_file_userprovided)); 2125 } 2126 2127 static void 2128 main_sigchld_handler(int sig) 2129 { 2130 int save_errno = errno; 2131 pid_t pid; 2132 int status; 2133 2134 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 2135 (pid < 0 && errno == EINTR)) 2136 ; 2137 errno = save_errno; 2138 } 2139