1 /* $OpenBSD: ssh.c,v 1.529 2020/06/05 03:15:26 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 SSLeay by Niels Provos <provos@citi.umich.edu> 20 * in Canada (German citizen). 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the above copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 41 */ 42 43 #include <sys/types.h> 44 #include <sys/ioctl.h> 45 #include <sys/queue.h> 46 #include <sys/resource.h> 47 #include <sys/socket.h> 48 #include <sys/stat.h> 49 #include <sys/time.h> 50 #include <sys/wait.h> 51 52 #include <ctype.h> 53 #include <errno.h> 54 #include <fcntl.h> 55 #include <netdb.h> 56 #include <paths.h> 57 #include <pwd.h> 58 #include <signal.h> 59 #include <stddef.h> 60 #include <stdio.h> 61 #include <stdlib.h> 62 #include <string.h> 63 #include <stdarg.h> 64 #include <unistd.h> 65 #include <limits.h> 66 #include <locale.h> 67 68 #ifdef WITH_OPENSSL 69 #include <openssl/evp.h> 70 #include <openssl/err.h> 71 #endif 72 73 #include "xmalloc.h" 74 #include "ssh.h" 75 #include "ssh2.h" 76 #include "canohost.h" 77 #include "compat.h" 78 #include "cipher.h" 79 #include "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 /* 155 * A config can specify a path to forward, overriding SSH_AUTH_SOCK. If this is 156 * not NULL, forward the socket at this path instead. 157 */ 158 char *forward_agent_sock_path = NULL; 159 160 /* Various strings used to to percent_expand() arguments */ 161 static char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 162 static char uidstr[32], *host_arg, *conn_hash_hex; 163 164 /* socket address the host resolves to */ 165 struct sockaddr_storage hostaddr; 166 167 /* Private host keys. */ 168 Sensitive sensitive_data; 169 170 /* command to be executed */ 171 struct sshbuf *command; 172 173 /* Should we execute a command or invoke a subsystem? */ 174 int subsystem_flag = 0; 175 176 /* # of replies received for global requests */ 177 static int forward_confirms_pending = -1; 178 179 /* mux.c */ 180 extern int muxserver_sock; 181 extern u_int muxclient_command; 182 183 /* Prints a help message to the user. This function never returns. */ 184 185 static void 186 usage(void) 187 { 188 fprintf(stderr, 189 "usage: ssh [-46AaCfGgKkMNnqsTtVvXxYy] [-B bind_interface]\n" 190 " [-b bind_address] [-c cipher_spec] [-D [bind_address:]port]\n" 191 " [-E log_file] [-e escape_char] [-F configfile] [-I pkcs11]\n" 192 " [-i identity_file] [-J [user@]host[:port]] [-L address]\n" 193 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" 194 " [-Q query_option] [-R address] [-S ctl_path] [-W host:port]\n" 195 " [-w local_tun[:remote_tun]] destination [command]\n" 196 ); 197 exit(255); 198 } 199 200 static int ssh_session2(struct ssh *, struct passwd *); 201 static void load_public_identity_files(struct passwd *); 202 static void main_sigchld_handler(int); 203 204 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 205 static void 206 tilde_expand_paths(char **paths, u_int num_paths) 207 { 208 u_int i; 209 char *cp; 210 211 for (i = 0; i < num_paths; i++) { 212 cp = tilde_expand_filename(paths[i], getuid()); 213 free(paths[i]); 214 paths[i] = cp; 215 } 216 } 217 218 #define DEFAULT_CLIENT_PERCENT_EXPAND_ARGS \ 219 "C", conn_hash_hex, \ 220 "L", shorthost, \ 221 "i", uidstr, \ 222 "l", thishost, \ 223 "n", host_arg, \ 224 "p", portstr 225 226 /* 227 * Expands the set of percent_expand options used by the majority of keywords 228 * in the client that support percent expansion. 229 * Caller must free returned string. 230 */ 231 static char * 232 default_client_percent_expand(const char *str, const char *homedir, 233 const char *remhost, const char *remuser, const char *locuser) 234 { 235 return percent_expand(str, 236 /* values from statics above */ 237 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS, 238 /* values from arguments */ 239 "d", homedir, 240 "h", remhost, 241 "r", remuser, 242 "u", locuser, 243 (char *)NULL); 244 } 245 246 /* 247 * Expands the set of percent_expand options used by the majority of keywords 248 * AND perform environment variable substitution. 249 * Caller must free returned string. 250 */ 251 static char * 252 default_client_percent_dollar_expand(const char *str, const char *homedir, 253 const char *remhost, const char *remuser, const char *locuser) 254 { 255 char *ret; 256 257 ret = percent_dollar_expand(str, 258 /* values from statics above */ 259 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS, 260 /* values from arguments */ 261 "d", homedir, 262 "h", remhost, 263 "r", remuser, 264 "u", locuser, 265 (char *)NULL); 266 if (ret == NULL) 267 fatal("invalid environment variable expansion"); 268 return ret; 269 } 270 271 /* 272 * Attempt to resolve a host name / port to a set of addresses and 273 * optionally return any CNAMEs encountered along the way. 274 * Returns NULL on failure. 275 * NB. this function must operate with a options having undefined members. 276 */ 277 static struct addrinfo * 278 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen) 279 { 280 char strport[NI_MAXSERV]; 281 struct addrinfo hints, *res; 282 int gaierr; 283 LogLevel loglevel = SYSLOG_LEVEL_DEBUG1; 284 285 if (port <= 0) 286 port = default_ssh_port(); 287 if (cname != NULL) 288 *cname = '\0'; 289 290 snprintf(strport, sizeof strport, "%d", port); 291 memset(&hints, 0, sizeof(hints)); 292 hints.ai_family = options.address_family == -1 ? 293 AF_UNSPEC : options.address_family; 294 hints.ai_socktype = SOCK_STREAM; 295 if (cname != NULL) 296 hints.ai_flags = AI_CANONNAME; 297 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 298 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) 299 loglevel = SYSLOG_LEVEL_ERROR; 300 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", 301 __progname, name, ssh_gai_strerror(gaierr)); 302 return NULL; 303 } 304 if (cname != NULL && res->ai_canonname != NULL) { 305 if (strlcpy(cname, res->ai_canonname, clen) >= clen) { 306 error("%s: host \"%s\" cname \"%s\" too long (max %lu)", 307 __func__, name, res->ai_canonname, (u_long)clen); 308 if (clen > 0) 309 *cname = '\0'; 310 } 311 } 312 return res; 313 } 314 315 /* Returns non-zero if name can only be an address and not a hostname */ 316 static int 317 is_addr_fast(const char *name) 318 { 319 return (strchr(name, '%') != NULL || strchr(name, ':') != NULL || 320 strspn(name, "0123456789.") == strlen(name)); 321 } 322 323 /* Returns non-zero if name represents a valid, single address */ 324 static int 325 is_addr(const char *name) 326 { 327 char strport[NI_MAXSERV]; 328 struct addrinfo hints, *res; 329 330 if (is_addr_fast(name)) 331 return 1; 332 333 snprintf(strport, sizeof strport, "%u", default_ssh_port()); 334 memset(&hints, 0, sizeof(hints)); 335 hints.ai_family = options.address_family == -1 ? 336 AF_UNSPEC : options.address_family; 337 hints.ai_socktype = SOCK_STREAM; 338 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 339 if (getaddrinfo(name, strport, &hints, &res) != 0) 340 return 0; 341 if (res == NULL || res->ai_next != NULL) { 342 freeaddrinfo(res); 343 return 0; 344 } 345 freeaddrinfo(res); 346 return 1; 347 } 348 349 /* 350 * Attempt to resolve a numeric host address / port to a single address. 351 * Returns a canonical address string. 352 * Returns NULL on failure. 353 * NB. this function must operate with a options having undefined members. 354 */ 355 static struct addrinfo * 356 resolve_addr(const char *name, int port, char *caddr, size_t clen) 357 { 358 char addr[NI_MAXHOST], strport[NI_MAXSERV]; 359 struct addrinfo hints, *res; 360 int gaierr; 361 362 if (port <= 0) 363 port = default_ssh_port(); 364 snprintf(strport, sizeof strport, "%u", port); 365 memset(&hints, 0, sizeof(hints)); 366 hints.ai_family = options.address_family == -1 ? 367 AF_UNSPEC : options.address_family; 368 hints.ai_socktype = SOCK_STREAM; 369 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 370 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 371 debug2("%s: could not resolve name %.100s as address: %s", 372 __func__, name, ssh_gai_strerror(gaierr)); 373 return NULL; 374 } 375 if (res == NULL) { 376 debug("%s: getaddrinfo %.100s returned no addresses", 377 __func__, name); 378 return NULL; 379 } 380 if (res->ai_next != NULL) { 381 debug("%s: getaddrinfo %.100s returned multiple addresses", 382 __func__, name); 383 goto fail; 384 } 385 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen, 386 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) { 387 debug("%s: Could not format address for name %.100s: %s", 388 __func__, name, ssh_gai_strerror(gaierr)); 389 goto fail; 390 } 391 if (strlcpy(caddr, addr, clen) >= clen) { 392 error("%s: host \"%s\" addr \"%s\" too long (max %lu)", 393 __func__, name, addr, (u_long)clen); 394 if (clen > 0) 395 *caddr = '\0'; 396 fail: 397 freeaddrinfo(res); 398 return NULL; 399 } 400 return res; 401 } 402 403 /* 404 * Check whether the cname is a permitted replacement for the hostname 405 * and perform the replacement if it is. 406 * NB. this function must operate with a options having undefined members. 407 */ 408 static int 409 check_follow_cname(int direct, char **namep, const char *cname) 410 { 411 int i; 412 struct allowed_cname *rule; 413 414 if (*cname == '\0' || options.num_permitted_cnames == 0 || 415 strcmp(*namep, cname) == 0) 416 return 0; 417 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 418 return 0; 419 /* 420 * Don't attempt to canonicalize names that will be interpreted by 421 * a proxy or jump host unless the user specifically requests so. 422 */ 423 if (!direct && 424 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 425 return 0; 426 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname); 427 for (i = 0; i < options.num_permitted_cnames; i++) { 428 rule = options.permitted_cnames + i; 429 if (match_pattern_list(*namep, rule->source_list, 1) != 1 || 430 match_pattern_list(cname, rule->target_list, 1) != 1) 431 continue; 432 verbose("Canonicalized DNS aliased hostname " 433 "\"%s\" => \"%s\"", *namep, cname); 434 free(*namep); 435 *namep = xstrdup(cname); 436 return 1; 437 } 438 return 0; 439 } 440 441 /* 442 * Attempt to resolve the supplied hostname after applying the user's 443 * canonicalization rules. Returns the address list for the host or NULL 444 * if no name was found after canonicalization. 445 * NB. this function must operate with a options having undefined members. 446 */ 447 static struct addrinfo * 448 resolve_canonicalize(char **hostp, int port) 449 { 450 int i, direct, ndots; 451 char *cp, *fullhost, newname[NI_MAXHOST]; 452 struct addrinfo *addrs; 453 454 /* 455 * Attempt to canonicalise addresses, regardless of 456 * whether hostname canonicalisation was requested 457 */ 458 if ((addrs = resolve_addr(*hostp, port, 459 newname, sizeof(newname))) != NULL) { 460 debug2("%s: hostname %.100s is address", __func__, *hostp); 461 if (strcasecmp(*hostp, newname) != 0) { 462 debug2("%s: canonicalised address \"%s\" => \"%s\"", 463 __func__, *hostp, newname); 464 free(*hostp); 465 *hostp = xstrdup(newname); 466 } 467 return addrs; 468 } 469 470 /* 471 * If this looks like an address but didn't parse as one, it might 472 * be an address with an invalid interface scope. Skip further 473 * attempts at canonicalisation. 474 */ 475 if (is_addr_fast(*hostp)) { 476 debug("%s: hostname %.100s is an unrecognised address", 477 __func__, *hostp); 478 return NULL; 479 } 480 481 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 482 return NULL; 483 484 /* 485 * Don't attempt to canonicalize names that will be interpreted by 486 * a proxy unless the user specifically requests so. 487 */ 488 direct = option_clear_or_none(options.proxy_command) && 489 options.jump_host == NULL; 490 if (!direct && 491 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 492 return NULL; 493 494 /* If domain name is anchored, then resolve it now */ 495 if ((*hostp)[strlen(*hostp) - 1] == '.') { 496 debug3("%s: name is fully qualified", __func__); 497 fullhost = xstrdup(*hostp); 498 if ((addrs = resolve_host(fullhost, port, 0, 499 newname, sizeof(newname))) != NULL) 500 goto found; 501 free(fullhost); 502 goto notfound; 503 } 504 505 /* Don't apply canonicalization to sufficiently-qualified hostnames */ 506 ndots = 0; 507 for (cp = *hostp; *cp != '\0'; cp++) { 508 if (*cp == '.') 509 ndots++; 510 } 511 if (ndots > options.canonicalize_max_dots) { 512 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)", 513 __func__, *hostp, options.canonicalize_max_dots); 514 return NULL; 515 } 516 /* Attempt each supplied suffix */ 517 for (i = 0; i < options.num_canonical_domains; i++) { 518 xasprintf(&fullhost, "%s.%s.", *hostp, 519 options.canonical_domains[i]); 520 debug3("%s: attempting \"%s\" => \"%s\"", __func__, 521 *hostp, fullhost); 522 if ((addrs = resolve_host(fullhost, port, 0, 523 newname, sizeof(newname))) == NULL) { 524 free(fullhost); 525 continue; 526 } 527 found: 528 /* Remove trailing '.' */ 529 fullhost[strlen(fullhost) - 1] = '\0'; 530 /* Follow CNAME if requested */ 531 if (!check_follow_cname(direct, &fullhost, newname)) { 532 debug("Canonicalized hostname \"%s\" => \"%s\"", 533 *hostp, fullhost); 534 } 535 free(*hostp); 536 *hostp = fullhost; 537 return addrs; 538 } 539 notfound: 540 if (!options.canonicalize_fallback_local) 541 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); 542 debug2("%s: host %s not found in any suffix", __func__, *hostp); 543 return NULL; 544 } 545 546 /* 547 * Check the result of hostkey loading, ignoring some errors and 548 * fatal()ing for others. 549 */ 550 static void 551 check_load(int r, const char *path, const char *message) 552 { 553 switch (r) { 554 case 0: 555 break; 556 case SSH_ERR_INTERNAL_ERROR: 557 case SSH_ERR_ALLOC_FAIL: 558 fatal("load %s \"%s\": %s", message, path, ssh_err(r)); 559 case SSH_ERR_SYSTEM_ERROR: 560 /* Ignore missing files */ 561 if (errno == ENOENT) 562 break; 563 /* FALLTHROUGH */ 564 default: 565 error("load %s \"%s\": %s", message, path, ssh_err(r)); 566 break; 567 } 568 } 569 570 /* 571 * Read per-user configuration file. Ignore the system wide config 572 * file if the user specifies a config file on the command line. 573 */ 574 static void 575 process_config_files(const char *host_name, struct passwd *pw, int final_pass, 576 int *want_final_pass) 577 { 578 char buf[PATH_MAX]; 579 int r; 580 581 if (config != NULL) { 582 if (strcasecmp(config, "none") != 0 && 583 !read_config_file(config, pw, host, host_name, &options, 584 SSHCONF_USERCONF | (final_pass ? SSHCONF_FINAL : 0), 585 want_final_pass)) 586 fatal("Can't open user config file %.100s: " 587 "%.100s", config, strerror(errno)); 588 } else { 589 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 590 _PATH_SSH_USER_CONFFILE); 591 if (r > 0 && (size_t)r < sizeof(buf)) 592 (void)read_config_file(buf, pw, host, host_name, 593 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF | 594 (final_pass ? SSHCONF_FINAL : 0), want_final_pass); 595 596 /* Read systemwide configuration file after user config. */ 597 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, 598 host, host_name, &options, 599 final_pass ? SSHCONF_FINAL : 0, want_final_pass); 600 } 601 } 602 603 /* Rewrite the port number in an addrinfo list of addresses */ 604 static void 605 set_addrinfo_port(struct addrinfo *addrs, int port) 606 { 607 struct addrinfo *addr; 608 609 for (addr = addrs; addr != NULL; addr = addr->ai_next) { 610 switch (addr->ai_family) { 611 case AF_INET: 612 ((struct sockaddr_in *)addr->ai_addr)-> 613 sin_port = htons(port); 614 break; 615 case AF_INET6: 616 ((struct sockaddr_in6 *)addr->ai_addr)-> 617 sin6_port = htons(port); 618 break; 619 } 620 } 621 } 622 623 /* 624 * Main program for the ssh client. 625 */ 626 int 627 main(int ac, char **av) 628 { 629 struct ssh *ssh = NULL; 630 int i, r, opt, exit_status, use_syslog, direct, timeout_ms; 631 int was_addr, config_test = 0, opt_terminated = 0, want_final_pass = 0; 632 char *p, *cp, *line, *argv0, buf[PATH_MAX], *logfile; 633 char cname[NI_MAXHOST]; 634 struct stat st; 635 struct passwd *pw; 636 extern int optind, optreset; 637 extern char *optarg; 638 struct Forward fwd; 639 struct addrinfo *addrs = NULL; 640 size_t n, len; 641 642 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 643 sanitise_stdfd(); 644 645 /* 646 * Discard other fds that are hanging around. These can cause problem 647 * with backgrounded ssh processes started by ControlPersist. 648 */ 649 closefrom(STDERR_FILENO + 1); 650 651 if (getuid() != geteuid()) 652 fatal("ssh setuid not supported."); 653 if (getgid() != getegid()) 654 fatal("ssh setgid not supported."); 655 656 /* Get user data. */ 657 pw = getpwuid(getuid()); 658 if (!pw) { 659 logit("No user exists for uid %lu", (u_long)getuid()); 660 exit(255); 661 } 662 /* Take a copy of the returned structure. */ 663 pw = pwcopy(pw); 664 665 /* 666 * Set our umask to something reasonable, as some files are created 667 * with the default umask. This will make them world-readable but 668 * writable only by the owner, which is ok for all files for which we 669 * don't set the modes explicitly. 670 */ 671 umask(022); 672 673 setlocale(LC_CTYPE, ""); 674 675 /* 676 * Initialize option structure to indicate that no values have been 677 * set. 678 */ 679 initialize_options(&options); 680 681 /* 682 * Prepare main ssh transport/connection structures 683 */ 684 if ((ssh = ssh_alloc_session_state()) == NULL) 685 fatal("Couldn't allocate session state"); 686 channel_init_channels(ssh); 687 688 /* Parse command-line arguments. */ 689 host = NULL; 690 use_syslog = 0; 691 logfile = NULL; 692 argv0 = av[0]; 693 694 again: 695 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 696 "AB:CD:E:F:GI:J:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { 697 switch (opt) { 698 case '1': 699 fatal("SSH protocol v.1 is no longer supported"); 700 break; 701 case '2': 702 /* Ignored */ 703 break; 704 case '4': 705 options.address_family = AF_INET; 706 break; 707 case '6': 708 options.address_family = AF_INET6; 709 break; 710 case 'n': 711 stdin_null_flag = 1; 712 break; 713 case 'f': 714 fork_after_authentication_flag = 1; 715 stdin_null_flag = 1; 716 break; 717 case 'x': 718 options.forward_x11 = 0; 719 break; 720 case 'X': 721 options.forward_x11 = 1; 722 break; 723 case 'y': 724 use_syslog = 1; 725 break; 726 case 'E': 727 logfile = optarg; 728 break; 729 case 'G': 730 config_test = 1; 731 break; 732 case 'Y': 733 options.forward_x11 = 1; 734 options.forward_x11_trusted = 1; 735 break; 736 case 'g': 737 options.fwd_opts.gateway_ports = 1; 738 break; 739 case 'O': 740 if (options.stdio_forward_host != NULL) 741 fatal("Cannot specify multiplexing " 742 "command with -W"); 743 else if (muxclient_command != 0) 744 fatal("Multiplexing command already specified"); 745 if (strcmp(optarg, "check") == 0) 746 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 747 else if (strcmp(optarg, "forward") == 0) 748 muxclient_command = SSHMUX_COMMAND_FORWARD; 749 else if (strcmp(optarg, "exit") == 0) 750 muxclient_command = SSHMUX_COMMAND_TERMINATE; 751 else if (strcmp(optarg, "stop") == 0) 752 muxclient_command = SSHMUX_COMMAND_STOP; 753 else if (strcmp(optarg, "cancel") == 0) 754 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 755 else if (strcmp(optarg, "proxy") == 0) 756 muxclient_command = SSHMUX_COMMAND_PROXY; 757 else 758 fatal("Invalid multiplex command."); 759 break; 760 case 'P': /* deprecated */ 761 break; 762 case 'Q': 763 cp = NULL; 764 if (strcmp(optarg, "cipher") == 0 || 765 strcasecmp(optarg, "Ciphers") == 0) 766 cp = cipher_alg_list('\n', 0); 767 else if (strcmp(optarg, "cipher-auth") == 0) 768 cp = cipher_alg_list('\n', 1); 769 else if (strcmp(optarg, "mac") == 0 || 770 strcasecmp(optarg, "MACs") == 0) 771 cp = mac_alg_list('\n'); 772 else if (strcmp(optarg, "kex") == 0 || 773 strcasecmp(optarg, "KexAlgorithms") == 0) 774 cp = kex_alg_list('\n'); 775 else if (strcmp(optarg, "key") == 0) 776 cp = sshkey_alg_list(0, 0, 0, '\n'); 777 else if (strcmp(optarg, "key-cert") == 0) 778 cp = sshkey_alg_list(1, 0, 0, '\n'); 779 else if (strcmp(optarg, "key-plain") == 0) 780 cp = sshkey_alg_list(0, 1, 0, '\n'); 781 else if (strcmp(optarg, "key-sig") == 0 || 782 strcasecmp(optarg, "PubkeyAcceptedKeyTypes") == 0 || 783 strcasecmp(optarg, "HostKeyAlgorithms") == 0 || 784 strcasecmp(optarg, "HostbasedKeyTypes") == 0 || 785 strcasecmp(optarg, "HostbasedAcceptedKeyTypes") == 0) 786 cp = sshkey_alg_list(0, 0, 1, '\n'); 787 else if (strcmp(optarg, "sig") == 0) 788 cp = sshkey_alg_list(0, 1, 1, '\n'); 789 else if (strcmp(optarg, "protocol-version") == 0) 790 cp = xstrdup("2"); 791 else if (strcmp(optarg, "compression") == 0) { 792 cp = xstrdup(compression_alg_list(0)); 793 len = strlen(cp); 794 for (n = 0; n < len; n++) 795 if (cp[n] == ',') 796 cp[n] = '\n'; 797 } else if (strcmp(optarg, "help") == 0) { 798 cp = xstrdup( 799 "cipher\ncipher-auth\ncompression\nkex\n" 800 "key\nkey-cert\nkey-plain\nkey-sig\nmac\n" 801 "protocol-version\nsig"); 802 } 803 if (cp == NULL) 804 fatal("Unsupported query \"%s\"", optarg); 805 printf("%s\n", cp); 806 free(cp); 807 exit(0); 808 break; 809 case 'a': 810 options.forward_agent = 0; 811 break; 812 case 'A': 813 options.forward_agent = 1; 814 break; 815 case 'k': 816 options.gss_deleg_creds = 0; 817 break; 818 case 'K': 819 options.gss_authentication = 1; 820 options.gss_deleg_creds = 1; 821 break; 822 case 'i': 823 p = tilde_expand_filename(optarg, getuid()); 824 if (stat(p, &st) == -1) 825 fprintf(stderr, "Warning: Identity file %s " 826 "not accessible: %s.\n", p, 827 strerror(errno)); 828 else 829 add_identity_file(&options, NULL, p, 1); 830 free(p); 831 break; 832 case 'I': 833 #ifdef ENABLE_PKCS11 834 free(options.pkcs11_provider); 835 options.pkcs11_provider = xstrdup(optarg); 836 #else 837 fprintf(stderr, "no support for PKCS#11.\n"); 838 #endif 839 break; 840 case 'J': 841 if (options.jump_host != NULL) { 842 fatal("Only a single -J option is permitted " 843 "(use commas to separate multiple " 844 "jump hops)"); 845 } 846 if (options.proxy_command != NULL) 847 fatal("Cannot specify -J with ProxyCommand"); 848 if (parse_jump(optarg, &options, 1) == -1) 849 fatal("Invalid -J argument"); 850 options.proxy_command = xstrdup("none"); 851 break; 852 case 't': 853 if (options.request_tty == REQUEST_TTY_YES) 854 options.request_tty = REQUEST_TTY_FORCE; 855 else 856 options.request_tty = REQUEST_TTY_YES; 857 break; 858 case 'v': 859 if (debug_flag == 0) { 860 debug_flag = 1; 861 options.log_level = SYSLOG_LEVEL_DEBUG1; 862 } else { 863 if (options.log_level < SYSLOG_LEVEL_DEBUG3) { 864 debug_flag++; 865 options.log_level++; 866 } 867 } 868 break; 869 case 'V': 870 fprintf(stderr, "%s, %s\n", 871 SSH_VERSION, 872 #ifdef WITH_OPENSSL 873 OpenSSL_version(OPENSSL_VERSION) 874 #else 875 "without OpenSSL" 876 #endif 877 ); 878 if (opt == 'V') 879 exit(0); 880 break; 881 case 'w': 882 if (options.tun_open == -1) 883 options.tun_open = SSH_TUNMODE_DEFAULT; 884 options.tun_local = a2tun(optarg, &options.tun_remote); 885 if (options.tun_local == SSH_TUNID_ERR) { 886 fprintf(stderr, 887 "Bad tun device '%s'\n", optarg); 888 exit(255); 889 } 890 break; 891 case 'W': 892 if (options.stdio_forward_host != NULL) 893 fatal("stdio forward already specified"); 894 if (muxclient_command != 0) 895 fatal("Cannot specify stdio forward with -O"); 896 if (parse_forward(&fwd, optarg, 1, 0)) { 897 options.stdio_forward_host = fwd.listen_host; 898 options.stdio_forward_port = fwd.listen_port; 899 free(fwd.connect_host); 900 } else { 901 fprintf(stderr, 902 "Bad stdio forwarding specification '%s'\n", 903 optarg); 904 exit(255); 905 } 906 options.request_tty = REQUEST_TTY_NO; 907 no_shell_flag = 1; 908 break; 909 case 'q': 910 options.log_level = SYSLOG_LEVEL_QUIET; 911 break; 912 case 'e': 913 if (optarg[0] == '^' && optarg[2] == 0 && 914 (u_char) optarg[1] >= 64 && 915 (u_char) optarg[1] < 128) 916 options.escape_char = (u_char) optarg[1] & 31; 917 else if (strlen(optarg) == 1) 918 options.escape_char = (u_char) optarg[0]; 919 else if (strcmp(optarg, "none") == 0) 920 options.escape_char = SSH_ESCAPECHAR_NONE; 921 else { 922 fprintf(stderr, "Bad escape character '%s'.\n", 923 optarg); 924 exit(255); 925 } 926 break; 927 case 'c': 928 if (!ciphers_valid(*optarg == '+' || *optarg == '^' ? 929 optarg + 1 : optarg)) { 930 fprintf(stderr, "Unknown cipher type '%s'\n", 931 optarg); 932 exit(255); 933 } 934 free(options.ciphers); 935 options.ciphers = xstrdup(optarg); 936 break; 937 case 'm': 938 if (mac_valid(optarg)) { 939 free(options.macs); 940 options.macs = xstrdup(optarg); 941 } else { 942 fprintf(stderr, "Unknown mac type '%s'\n", 943 optarg); 944 exit(255); 945 } 946 break; 947 case 'M': 948 if (options.control_master == SSHCTL_MASTER_YES) 949 options.control_master = SSHCTL_MASTER_ASK; 950 else 951 options.control_master = SSHCTL_MASTER_YES; 952 break; 953 case 'p': 954 if (options.port == -1) { 955 options.port = a2port(optarg); 956 if (options.port <= 0) { 957 fprintf(stderr, "Bad port '%s'\n", 958 optarg); 959 exit(255); 960 } 961 } 962 break; 963 case 'l': 964 if (options.user == NULL) 965 options.user = optarg; 966 break; 967 968 case 'L': 969 if (parse_forward(&fwd, optarg, 0, 0)) 970 add_local_forward(&options, &fwd); 971 else { 972 fprintf(stderr, 973 "Bad local forwarding specification '%s'\n", 974 optarg); 975 exit(255); 976 } 977 break; 978 979 case 'R': 980 if (parse_forward(&fwd, optarg, 0, 1) || 981 parse_forward(&fwd, optarg, 1, 1)) { 982 add_remote_forward(&options, &fwd); 983 } else { 984 fprintf(stderr, 985 "Bad remote forwarding specification " 986 "'%s'\n", optarg); 987 exit(255); 988 } 989 break; 990 991 case 'D': 992 if (parse_forward(&fwd, optarg, 1, 0)) { 993 add_local_forward(&options, &fwd); 994 } else { 995 fprintf(stderr, 996 "Bad dynamic forwarding specification " 997 "'%s'\n", optarg); 998 exit(255); 999 } 1000 break; 1001 1002 case 'C': 1003 #ifdef WITH_ZLIB 1004 options.compression = 1; 1005 #else 1006 error("Compression not supported, disabling."); 1007 #endif 1008 break; 1009 case 'N': 1010 no_shell_flag = 1; 1011 options.request_tty = REQUEST_TTY_NO; 1012 break; 1013 case 'T': 1014 options.request_tty = REQUEST_TTY_NO; 1015 break; 1016 case 'o': 1017 line = xstrdup(optarg); 1018 if (process_config_line(&options, pw, 1019 host ? host : "", host ? host : "", line, 1020 "command-line", 0, NULL, SSHCONF_USERCONF) != 0) 1021 exit(255); 1022 free(line); 1023 break; 1024 case 's': 1025 subsystem_flag = 1; 1026 break; 1027 case 'S': 1028 free(options.control_path); 1029 options.control_path = xstrdup(optarg); 1030 break; 1031 case 'b': 1032 options.bind_address = optarg; 1033 break; 1034 case 'B': 1035 options.bind_interface = optarg; 1036 break; 1037 case 'F': 1038 config = optarg; 1039 break; 1040 default: 1041 usage(); 1042 } 1043 } 1044 1045 if (optind > 1 && strcmp(av[optind - 1], "--") == 0) 1046 opt_terminated = 1; 1047 1048 ac -= optind; 1049 av += optind; 1050 1051 if (ac > 0 && !host) { 1052 int tport; 1053 char *tuser; 1054 switch (parse_ssh_uri(*av, &tuser, &host, &tport)) { 1055 case -1: 1056 usage(); 1057 break; 1058 case 0: 1059 if (options.user == NULL) { 1060 options.user = tuser; 1061 tuser = NULL; 1062 } 1063 free(tuser); 1064 if (options.port == -1 && tport != -1) 1065 options.port = tport; 1066 break; 1067 default: 1068 p = xstrdup(*av); 1069 cp = strrchr(p, '@'); 1070 if (cp != NULL) { 1071 if (cp == p) 1072 usage(); 1073 if (options.user == NULL) { 1074 options.user = p; 1075 p = NULL; 1076 } 1077 *cp++ = '\0'; 1078 host = xstrdup(cp); 1079 free(p); 1080 } else 1081 host = p; 1082 break; 1083 } 1084 if (ac > 1 && !opt_terminated) { 1085 optind = optreset = 1; 1086 goto again; 1087 } 1088 ac--, av++; 1089 } 1090 1091 /* Check that we got a host name. */ 1092 if (!host) 1093 usage(); 1094 1095 host_arg = xstrdup(host); 1096 1097 #ifdef WITH_OPENSSL 1098 OpenSSL_add_all_algorithms(); 1099 ERR_load_crypto_strings(); 1100 #endif 1101 1102 /* Initialize the command to execute on remote host. */ 1103 if ((command = sshbuf_new()) == NULL) 1104 fatal("sshbuf_new failed"); 1105 1106 /* 1107 * Save the command to execute on the remote host in a buffer. There 1108 * is no limit on the length of the command, except by the maximum 1109 * packet size. Also sets the tty flag if there is no command. 1110 */ 1111 if (!ac) { 1112 /* No command specified - execute shell on a tty. */ 1113 if (subsystem_flag) { 1114 fprintf(stderr, 1115 "You must specify a subsystem to invoke.\n"); 1116 usage(); 1117 } 1118 } else { 1119 /* A command has been specified. Store it into the buffer. */ 1120 for (i = 0; i < ac; i++) { 1121 if ((r = sshbuf_putf(command, "%s%s", 1122 i ? " " : "", av[i])) != 0) 1123 fatal("%s: buffer error: %s", 1124 __func__, ssh_err(r)); 1125 } 1126 } 1127 1128 /* 1129 * Initialize "log" output. Since we are the client all output 1130 * goes to stderr unless otherwise specified by -y or -E. 1131 */ 1132 if (use_syslog && logfile != NULL) 1133 fatal("Can't specify both -y and -E"); 1134 if (logfile != NULL) 1135 log_redirect_stderr_to(logfile); 1136 log_init(argv0, 1137 options.log_level == SYSLOG_LEVEL_NOT_SET ? 1138 SYSLOG_LEVEL_INFO : options.log_level, 1139 options.log_facility == SYSLOG_FACILITY_NOT_SET ? 1140 SYSLOG_FACILITY_USER : options.log_facility, 1141 !use_syslog); 1142 1143 if (debug_flag) 1144 logit("%s, %s", SSH_VERSION, 1145 #ifdef WITH_OPENSSL 1146 OpenSSL_version(OPENSSL_VERSION) 1147 #else 1148 "without OpenSSL" 1149 #endif 1150 ); 1151 1152 /* Parse the configuration files */ 1153 process_config_files(host_arg, pw, 0, &want_final_pass); 1154 if (want_final_pass) 1155 debug("configuration requests final Match pass"); 1156 1157 /* Hostname canonicalisation needs a few options filled. */ 1158 fill_default_options_for_canonicalization(&options); 1159 1160 /* If the user has replaced the hostname then take it into use now */ 1161 if (options.hostname != NULL) { 1162 /* NB. Please keep in sync with readconf.c:match_cfg_line() */ 1163 cp = percent_expand(options.hostname, 1164 "h", host, (char *)NULL); 1165 free(host); 1166 host = cp; 1167 free(options.hostname); 1168 options.hostname = xstrdup(host); 1169 } 1170 1171 /* Don't lowercase addresses, they will be explicitly canonicalised */ 1172 if ((was_addr = is_addr(host)) == 0) 1173 lowercase(host); 1174 1175 /* 1176 * Try to canonicalize if requested by configuration or the 1177 * hostname is an address. 1178 */ 1179 if (options.canonicalize_hostname != SSH_CANONICALISE_NO || was_addr) 1180 addrs = resolve_canonicalize(&host, options.port); 1181 1182 /* 1183 * If CanonicalizePermittedCNAMEs have been specified but 1184 * other canonicalization did not happen (by not being requested 1185 * or by failing with fallback) then the hostname may still be changed 1186 * as a result of CNAME following. 1187 * 1188 * Try to resolve the bare hostname name using the system resolver's 1189 * usual search rules and then apply the CNAME follow rules. 1190 * 1191 * Skip the lookup if a ProxyCommand is being used unless the user 1192 * has specifically requested canonicalisation for this case via 1193 * CanonicalizeHostname=always 1194 */ 1195 direct = option_clear_or_none(options.proxy_command) && 1196 options.jump_host == NULL; 1197 if (addrs == NULL && options.num_permitted_cnames != 0 && (direct || 1198 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { 1199 if ((addrs = resolve_host(host, options.port, 1200 direct, cname, sizeof(cname))) == NULL) { 1201 /* Don't fatal proxied host names not in the DNS */ 1202 if (direct) 1203 cleanup_exit(255); /* logged in resolve_host */ 1204 } else 1205 check_follow_cname(direct, &host, cname); 1206 } 1207 1208 /* 1209 * If canonicalisation is enabled then re-parse the configuration 1210 * files as new stanzas may match. 1211 */ 1212 if (options.canonicalize_hostname != 0 && !want_final_pass) { 1213 debug("hostname canonicalisation enabled, " 1214 "will re-parse configuration"); 1215 want_final_pass = 1; 1216 } 1217 1218 if (want_final_pass) { 1219 debug("re-parsing configuration"); 1220 free(options.hostname); 1221 options.hostname = xstrdup(host); 1222 process_config_files(host_arg, pw, 1, NULL); 1223 /* 1224 * Address resolution happens early with canonicalisation 1225 * enabled and the port number may have changed since, so 1226 * reset it in address list 1227 */ 1228 if (addrs != NULL && options.port > 0) 1229 set_addrinfo_port(addrs, options.port); 1230 } 1231 1232 /* Fill configuration defaults. */ 1233 fill_default_options(&options); 1234 1235 /* 1236 * If ProxyJump option specified, then construct a ProxyCommand now. 1237 */ 1238 if (options.jump_host != NULL) { 1239 char port_s[8]; 1240 const char *sshbin = argv0; 1241 int port = options.port, jumpport = options.jump_port; 1242 1243 if (port <= 0) 1244 port = default_ssh_port(); 1245 if (jumpport <= 0) 1246 jumpport = default_ssh_port(); 1247 if (strcmp(options.jump_host, host) == 0 && port == jumpport) 1248 fatal("jumphost loop via %s", options.jump_host); 1249 1250 /* 1251 * Try to use SSH indicated by argv[0], but fall back to 1252 * "ssh" if it appears unavailable. 1253 */ 1254 if (strchr(argv0, '/') != NULL && access(argv0, X_OK) != 0) 1255 sshbin = "ssh"; 1256 1257 /* Consistency check */ 1258 if (options.proxy_command != NULL) 1259 fatal("inconsistent options: ProxyCommand+ProxyJump"); 1260 /* Never use FD passing for ProxyJump */ 1261 options.proxy_use_fdpass = 0; 1262 snprintf(port_s, sizeof(port_s), "%d", options.jump_port); 1263 xasprintf(&options.proxy_command, 1264 "%s%s%s%s%s%s%s%s%s%s%.*s -W '[%%h]:%%p' %s", 1265 sshbin, 1266 /* Optional "-l user" argument if jump_user set */ 1267 options.jump_user == NULL ? "" : " -l ", 1268 options.jump_user == NULL ? "" : options.jump_user, 1269 /* Optional "-p port" argument if jump_port set */ 1270 options.jump_port <= 0 ? "" : " -p ", 1271 options.jump_port <= 0 ? "" : port_s, 1272 /* Optional additional jump hosts ",..." */ 1273 options.jump_extra == NULL ? "" : " -J ", 1274 options.jump_extra == NULL ? "" : options.jump_extra, 1275 /* Optional "-F" argumment if -F specified */ 1276 config == NULL ? "" : " -F ", 1277 config == NULL ? "" : config, 1278 /* Optional "-v" arguments if -v set */ 1279 debug_flag ? " -" : "", 1280 debug_flag, "vvv", 1281 /* Mandatory hostname */ 1282 options.jump_host); 1283 debug("Setting implicit ProxyCommand from ProxyJump: %s", 1284 options.proxy_command); 1285 } 1286 1287 if (options.port == 0) 1288 options.port = default_ssh_port(); 1289 channel_set_af(ssh, options.address_family); 1290 1291 /* Tidy and check options */ 1292 if (options.host_key_alias != NULL) 1293 lowercase(options.host_key_alias); 1294 if (options.proxy_command != NULL && 1295 strcmp(options.proxy_command, "-") == 0 && 1296 options.proxy_use_fdpass) 1297 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); 1298 if (options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 1299 if (options.control_persist && options.control_path != NULL) { 1300 debug("UpdateHostKeys=ask is incompatible with " 1301 "ControlPersist; disabling"); 1302 options.update_hostkeys = 0; 1303 } else if (sshbuf_len(command) != 0 || 1304 options.remote_command != NULL || 1305 options.request_tty == REQUEST_TTY_NO) { 1306 debug("UpdateHostKeys=ask is incompatible with " 1307 "remote command execution; disabling"); 1308 options.update_hostkeys = 0; 1309 } else if (options.log_level < SYSLOG_LEVEL_INFO) { 1310 /* no point logging anything; user won't see it */ 1311 options.update_hostkeys = 0; 1312 } 1313 } 1314 if (options.connection_attempts <= 0) 1315 fatal("Invalid number of ConnectionAttempts"); 1316 1317 if (sshbuf_len(command) != 0 && options.remote_command != NULL) 1318 fatal("Cannot execute command-line and remote command."); 1319 1320 /* Cannot fork to background if no command. */ 1321 if (fork_after_authentication_flag && sshbuf_len(command) == 0 && 1322 options.remote_command == NULL && !no_shell_flag) 1323 fatal("Cannot fork into background without a command " 1324 "to execute."); 1325 1326 /* reinit */ 1327 log_init(argv0, options.log_level, options.log_facility, !use_syslog); 1328 1329 if (options.request_tty == REQUEST_TTY_YES || 1330 options.request_tty == REQUEST_TTY_FORCE) 1331 tty_flag = 1; 1332 1333 /* Allocate a tty by default if no command specified. */ 1334 if (sshbuf_len(command) == 0 && options.remote_command == NULL) 1335 tty_flag = options.request_tty != REQUEST_TTY_NO; 1336 1337 /* Force no tty */ 1338 if (options.request_tty == REQUEST_TTY_NO || 1339 (muxclient_command && muxclient_command != SSHMUX_COMMAND_PROXY)) 1340 tty_flag = 0; 1341 /* Do not allocate a tty if stdin is not a tty. */ 1342 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 1343 options.request_tty != REQUEST_TTY_FORCE) { 1344 if (tty_flag) 1345 logit("Pseudo-terminal will not be allocated because " 1346 "stdin is not a terminal."); 1347 tty_flag = 0; 1348 } 1349 1350 if (options.user == NULL) 1351 options.user = xstrdup(pw->pw_name); 1352 1353 /* Set up strings used to percent_expand() arguments */ 1354 if (gethostname(thishost, sizeof(thishost)) == -1) 1355 fatal("gethostname: %s", strerror(errno)); 1356 strlcpy(shorthost, thishost, sizeof(shorthost)); 1357 shorthost[strcspn(thishost, ".")] = '\0'; 1358 snprintf(portstr, sizeof(portstr), "%d", options.port); 1359 snprintf(uidstr, sizeof(uidstr), "%llu", 1360 (unsigned long long)pw->pw_uid); 1361 1362 conn_hash_hex = ssh_connection_hash(thishost, host, portstr, 1363 options.user); 1364 1365 /* 1366 * Expand tokens in arguments. NB. LocalCommand is expanded later, 1367 * after port-forwarding is set up, so it may pick up any local 1368 * tunnel interface name allocated. 1369 */ 1370 if (options.remote_command != NULL) { 1371 debug3("expanding RemoteCommand: %s", options.remote_command); 1372 cp = options.remote_command; 1373 options.remote_command = default_client_percent_expand(cp, 1374 pw->pw_dir, host, options.user, pw->pw_name); 1375 debug3("expanded RemoteCommand: %s", options.remote_command); 1376 free(cp); 1377 if ((r = sshbuf_put(command, options.remote_command, 1378 strlen(options.remote_command))) != 0) 1379 fatal("%s: buffer error: %s", __func__, ssh_err(r)); 1380 } 1381 1382 if (options.control_path != NULL) { 1383 cp = tilde_expand_filename(options.control_path, getuid()); 1384 free(options.control_path); 1385 options.control_path = default_client_percent_dollar_expand(cp, 1386 pw->pw_dir, host, options.user, pw->pw_name); 1387 free(cp); 1388 } 1389 1390 if (options.identity_agent != NULL) { 1391 p = tilde_expand_filename(options.identity_agent, getuid()); 1392 cp = default_client_percent_dollar_expand(p, 1393 pw->pw_dir, host, options.user, pw->pw_name); 1394 free(p); 1395 free(options.identity_agent); 1396 options.identity_agent = cp; 1397 } 1398 1399 if (options.forward_agent_sock_path != NULL) { 1400 p = tilde_expand_filename(options.forward_agent_sock_path, 1401 getuid()); 1402 cp = default_client_percent_dollar_expand(p, 1403 pw->pw_dir, host, options.user, pw->pw_name); 1404 free(p); 1405 free(options.forward_agent_sock_path); 1406 options.forward_agent_sock_path = cp; 1407 } 1408 1409 for (i = 0; i < options.num_local_forwards; i++) { 1410 if (options.local_forwards[i].listen_path != NULL) { 1411 cp = options.local_forwards[i].listen_path; 1412 p = options.local_forwards[i].listen_path = 1413 default_client_percent_expand(cp, 1414 pw->pw_dir, host, options.user, pw->pw_name); 1415 if (strcmp(cp, p) != 0) 1416 debug3("expanded LocalForward listen path " 1417 "'%s' -> '%s'", cp, p); 1418 free(cp); 1419 } 1420 if (options.local_forwards[i].connect_path != NULL) { 1421 cp = options.local_forwards[i].connect_path; 1422 p = options.local_forwards[i].connect_path = 1423 default_client_percent_expand(cp, 1424 pw->pw_dir, host, options.user, pw->pw_name); 1425 if (strcmp(cp, p) != 0) 1426 debug3("expanded LocalForward connect path " 1427 "'%s' -> '%s'", cp, p); 1428 free(cp); 1429 } 1430 } 1431 1432 for (i = 0; i < options.num_remote_forwards; i++) { 1433 if (options.remote_forwards[i].listen_path != NULL) { 1434 cp = options.remote_forwards[i].listen_path; 1435 p = options.remote_forwards[i].listen_path = 1436 default_client_percent_expand(cp, 1437 pw->pw_dir, host, options.user, pw->pw_name); 1438 if (strcmp(cp, p) != 0) 1439 debug3("expanded RemoteForward listen path " 1440 "'%s' -> '%s'", cp, p); 1441 free(cp); 1442 } 1443 if (options.remote_forwards[i].connect_path != NULL) { 1444 cp = options.remote_forwards[i].connect_path; 1445 p = options.remote_forwards[i].connect_path = 1446 default_client_percent_expand(cp, 1447 pw->pw_dir, host, options.user, pw->pw_name); 1448 if (strcmp(cp, p) != 0) 1449 debug3("expanded RemoteForward connect path " 1450 "'%s' -> '%s'", cp, p); 1451 free(cp); 1452 } 1453 } 1454 1455 if (config_test) { 1456 dump_client_config(&options, host); 1457 exit(0); 1458 } 1459 1460 /* Expand SecurityKeyProvider if it refers to an environment variable */ 1461 if (options.sk_provider != NULL && *options.sk_provider == '$' && 1462 strlen(options.sk_provider) > 1) { 1463 if ((cp = getenv(options.sk_provider + 1)) == NULL) { 1464 debug("Authenticator provider %s did not resolve; " 1465 "disabling", options.sk_provider); 1466 free(options.sk_provider); 1467 options.sk_provider = NULL; 1468 } else { 1469 debug2("resolved SecurityKeyProvider %s => %s", 1470 options.sk_provider, cp); 1471 free(options.sk_provider); 1472 options.sk_provider = xstrdup(cp); 1473 } 1474 } 1475 1476 if (muxclient_command != 0 && options.control_path == NULL) 1477 fatal("No ControlPath specified for \"-O\" command"); 1478 if (options.control_path != NULL) { 1479 int sock; 1480 if ((sock = muxclient(options.control_path)) >= 0) { 1481 ssh_packet_set_connection(ssh, sock, sock); 1482 ssh_packet_set_mux(ssh); 1483 goto skip_connect; 1484 } 1485 } 1486 1487 /* 1488 * If hostname canonicalisation was not enabled, then we may not 1489 * have yet resolved the hostname. Do so now. 1490 */ 1491 if (addrs == NULL && options.proxy_command == NULL) { 1492 debug2("resolving \"%s\" port %d", host, options.port); 1493 if ((addrs = resolve_host(host, options.port, 1, 1494 cname, sizeof(cname))) == NULL) 1495 cleanup_exit(255); /* resolve_host logs the error */ 1496 } 1497 1498 timeout_ms = options.connection_timeout * 1000; 1499 1500 /* Open a connection to the remote host. */ 1501 if (ssh_connect(ssh, host, host_arg, addrs, &hostaddr, options.port, 1502 options.address_family, options.connection_attempts, 1503 &timeout_ms, options.tcp_keep_alive) != 0) 1504 exit(255); 1505 1506 if (addrs != NULL) 1507 freeaddrinfo(addrs); 1508 1509 ssh_packet_set_timeout(ssh, options.server_alive_interval, 1510 options.server_alive_count_max); 1511 1512 if (timeout_ms > 0) 1513 debug3("timeout: %d ms remain after connect", timeout_ms); 1514 1515 /* 1516 * If we successfully made the connection and we have hostbased auth 1517 * enabled, load the public keys so we can later use the ssh-keysign 1518 * helper to sign challenges. 1519 */ 1520 sensitive_data.nkeys = 0; 1521 sensitive_data.keys = NULL; 1522 if (options.hostbased_authentication) { 1523 sensitive_data.nkeys = 10; 1524 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 1525 sizeof(struct sshkey)); 1526 1527 /* XXX check errors? */ 1528 #define L_PUBKEY(p,o) do { \ 1529 if ((o) >= sensitive_data.nkeys) \ 1530 fatal("%s pubkey out of array bounds", __func__); \ 1531 check_load(sshkey_load_public(p, &(sensitive_data.keys[o]), NULL), \ 1532 p, "pubkey"); \ 1533 } while (0) 1534 #define L_CERT(p,o) do { \ 1535 if ((o) >= sensitive_data.nkeys) \ 1536 fatal("%s cert out of array bounds", __func__); \ 1537 check_load(sshkey_load_cert(p, &(sensitive_data.keys[o])), p, "cert"); \ 1538 } while (0) 1539 1540 if (options.hostbased_authentication == 1) { 1541 L_CERT(_PATH_HOST_ECDSA_KEY_FILE, 0); 1542 L_CERT(_PATH_HOST_ED25519_KEY_FILE, 1); 1543 L_CERT(_PATH_HOST_RSA_KEY_FILE, 2); 1544 L_CERT(_PATH_HOST_DSA_KEY_FILE, 3); 1545 L_PUBKEY(_PATH_HOST_ECDSA_KEY_FILE, 4); 1546 L_PUBKEY(_PATH_HOST_ED25519_KEY_FILE, 5); 1547 L_PUBKEY(_PATH_HOST_RSA_KEY_FILE, 6); 1548 L_PUBKEY(_PATH_HOST_DSA_KEY_FILE, 7); 1549 L_CERT(_PATH_HOST_XMSS_KEY_FILE, 8); 1550 L_PUBKEY(_PATH_HOST_XMSS_KEY_FILE, 9); 1551 } 1552 } 1553 1554 /* Create ~/.ssh * directory if it doesn't already exist. */ 1555 if (config == NULL) { 1556 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 1557 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 1558 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) == -1) 1559 if (mkdir(buf, 0700) == -1) 1560 error("Could not create directory '%.200s'.", 1561 buf); 1562 } 1563 1564 /* load options.identity_files */ 1565 load_public_identity_files(pw); 1566 1567 /* optionally set the SSH_AUTHSOCKET_ENV_NAME variable */ 1568 if (options.identity_agent && 1569 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) { 1570 if (strcmp(options.identity_agent, "none") == 0) { 1571 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1572 } else { 1573 cp = options.identity_agent; 1574 /* legacy (limited) format */ 1575 if (cp[0] == '$' && cp[1] != '{') { 1576 if (!valid_env_name(cp + 1)) { 1577 fatal("Invalid IdentityAgent " 1578 "environment variable name %s", cp); 1579 } 1580 if ((p = getenv(cp + 1)) == NULL) 1581 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1582 else 1583 setenv(SSH_AUTHSOCKET_ENV_NAME, p, 1); 1584 } else { 1585 /* identity_agent specifies a path directly */ 1586 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1); 1587 } 1588 } 1589 } 1590 1591 if (options.forward_agent && options.forward_agent_sock_path != NULL) { 1592 cp = options.forward_agent_sock_path; 1593 if (cp[0] == '$') { 1594 if (!valid_env_name(cp + 1)) { 1595 fatal("Invalid ForwardAgent environment variable name %s", cp); 1596 } 1597 if ((p = getenv(cp + 1)) != NULL) 1598 forward_agent_sock_path = p; 1599 else 1600 options.forward_agent = 0; 1601 free(cp); 1602 } else { 1603 forward_agent_sock_path = cp; 1604 } 1605 } 1606 1607 /* Expand ~ in known host file names. */ 1608 tilde_expand_paths(options.system_hostfiles, 1609 options.num_system_hostfiles); 1610 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 1611 1612 ssh_signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 1613 ssh_signal(SIGCHLD, main_sigchld_handler); 1614 1615 /* Log into the remote system. Never returns if the login fails. */ 1616 ssh_login(ssh, &sensitive_data, host, (struct sockaddr *)&hostaddr, 1617 options.port, pw, timeout_ms); 1618 1619 if (ssh_packet_connection_is_on_socket(ssh)) { 1620 verbose("Authenticated to %s ([%s]:%d).", host, 1621 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); 1622 } else { 1623 verbose("Authenticated to %s (via proxy).", host); 1624 } 1625 1626 /* We no longer need the private host keys. Clear them now. */ 1627 if (sensitive_data.nkeys != 0) { 1628 for (i = 0; i < sensitive_data.nkeys; i++) { 1629 if (sensitive_data.keys[i] != NULL) { 1630 /* Destroys contents safely */ 1631 debug3("clear hostkey %d", i); 1632 sshkey_free(sensitive_data.keys[i]); 1633 sensitive_data.keys[i] = NULL; 1634 } 1635 } 1636 free(sensitive_data.keys); 1637 } 1638 for (i = 0; i < options.num_identity_files; i++) { 1639 free(options.identity_files[i]); 1640 options.identity_files[i] = NULL; 1641 if (options.identity_keys[i]) { 1642 sshkey_free(options.identity_keys[i]); 1643 options.identity_keys[i] = NULL; 1644 } 1645 } 1646 for (i = 0; i < options.num_certificate_files; i++) { 1647 free(options.certificate_files[i]); 1648 options.certificate_files[i] = NULL; 1649 } 1650 1651 skip_connect: 1652 exit_status = ssh_session2(ssh, pw); 1653 ssh_packet_close(ssh); 1654 1655 if (options.control_path != NULL && muxserver_sock != -1) 1656 unlink(options.control_path); 1657 1658 /* Kill ProxyCommand if it is running. */ 1659 ssh_kill_proxy_command(); 1660 1661 return exit_status; 1662 } 1663 1664 static void 1665 control_persist_detach(void) 1666 { 1667 pid_t pid; 1668 int devnull, keep_stderr; 1669 1670 debug("%s: backgrounding master process", __func__); 1671 1672 /* 1673 * master (current process) into the background, and make the 1674 * foreground process a client of the backgrounded master. 1675 */ 1676 switch ((pid = fork())) { 1677 case -1: 1678 fatal("%s: fork: %s", __func__, strerror(errno)); 1679 case 0: 1680 /* Child: master process continues mainloop */ 1681 break; 1682 default: 1683 /* Parent: set up mux slave to connect to backgrounded master */ 1684 debug2("%s: background process is %ld", __func__, (long)pid); 1685 stdin_null_flag = ostdin_null_flag; 1686 options.request_tty = orequest_tty; 1687 tty_flag = otty_flag; 1688 close(muxserver_sock); 1689 muxserver_sock = -1; 1690 options.control_master = SSHCTL_MASTER_NO; 1691 muxclient(options.control_path); 1692 /* muxclient() doesn't return on success. */ 1693 fatal("Failed to connect to new control master"); 1694 } 1695 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1696 error("%s: open(\"/dev/null\"): %s", __func__, 1697 strerror(errno)); 1698 } else { 1699 keep_stderr = log_is_on_stderr() && debug_flag; 1700 if (dup2(devnull, STDIN_FILENO) == -1 || 1701 dup2(devnull, STDOUT_FILENO) == -1 || 1702 (!keep_stderr && dup2(devnull, STDERR_FILENO) == -1)) 1703 error("%s: dup2: %s", __func__, strerror(errno)); 1704 if (devnull > STDERR_FILENO) 1705 close(devnull); 1706 } 1707 daemon(1, 1); 1708 setproctitle("%s [mux]", options.control_path); 1709 } 1710 1711 /* Do fork() after authentication. Used by "ssh -f" */ 1712 static void 1713 fork_postauth(void) 1714 { 1715 if (need_controlpersist_detach) 1716 control_persist_detach(); 1717 debug("forking to background"); 1718 fork_after_authentication_flag = 0; 1719 if (daemon(1, 1) == -1) 1720 fatal("daemon() failed: %.200s", strerror(errno)); 1721 } 1722 1723 static void 1724 forwarding_success(void) 1725 { 1726 if (forward_confirms_pending == -1) 1727 return; 1728 if (--forward_confirms_pending == 0) { 1729 debug("%s: all expected forwarding replies received", __func__); 1730 if (fork_after_authentication_flag) 1731 fork_postauth(); 1732 } else { 1733 debug2("%s: %d expected forwarding replies remaining", 1734 __func__, forward_confirms_pending); 1735 } 1736 } 1737 1738 /* Callback for remote forward global requests */ 1739 static void 1740 ssh_confirm_remote_forward(struct ssh *ssh, int type, u_int32_t seq, void *ctxt) 1741 { 1742 struct Forward *rfwd = (struct Forward *)ctxt; 1743 u_int port; 1744 int r; 1745 1746 /* XXX verbose() on failure? */ 1747 debug("remote forward %s for: listen %s%s%d, connect %s:%d", 1748 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1749 rfwd->listen_path ? rfwd->listen_path : 1750 rfwd->listen_host ? rfwd->listen_host : "", 1751 (rfwd->listen_path || rfwd->listen_host) ? ":" : "", 1752 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path : 1753 rfwd->connect_host, rfwd->connect_port); 1754 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) { 1755 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1756 if ((r = sshpkt_get_u32(ssh, &port)) != 0) 1757 fatal("%s: %s", __func__, ssh_err(r)); 1758 if (port > 65535) { 1759 error("Invalid allocated port %u for remote " 1760 "forward to %s:%d", port, 1761 rfwd->connect_host, rfwd->connect_port); 1762 /* Ensure failure processing runs below */ 1763 type = SSH2_MSG_REQUEST_FAILURE; 1764 channel_update_permission(ssh, 1765 rfwd->handle, -1); 1766 } else { 1767 rfwd->allocated_port = (int)port; 1768 logit("Allocated port %u for remote " 1769 "forward to %s:%d", 1770 rfwd->allocated_port, rfwd->connect_host, 1771 rfwd->connect_port); 1772 channel_update_permission(ssh, 1773 rfwd->handle, rfwd->allocated_port); 1774 } 1775 } else { 1776 channel_update_permission(ssh, rfwd->handle, -1); 1777 } 1778 } 1779 1780 if (type == SSH2_MSG_REQUEST_FAILURE) { 1781 if (options.exit_on_forward_failure) { 1782 if (rfwd->listen_path != NULL) 1783 fatal("Error: remote port forwarding failed " 1784 "for listen path %s", rfwd->listen_path); 1785 else 1786 fatal("Error: remote port forwarding failed " 1787 "for listen port %d", rfwd->listen_port); 1788 } else { 1789 if (rfwd->listen_path != NULL) 1790 logit("Warning: remote port forwarding failed " 1791 "for listen path %s", rfwd->listen_path); 1792 else 1793 logit("Warning: remote port forwarding failed " 1794 "for listen port %d", rfwd->listen_port); 1795 } 1796 } 1797 forwarding_success(); 1798 } 1799 1800 static void 1801 client_cleanup_stdio_fwd(struct ssh *ssh, int id, void *arg) 1802 { 1803 debug("stdio forwarding: done"); 1804 cleanup_exit(0); 1805 } 1806 1807 static void 1808 ssh_stdio_confirm(struct ssh *ssh, int id, int success, void *arg) 1809 { 1810 if (!success) 1811 fatal("stdio forwarding failed"); 1812 } 1813 1814 static void 1815 ssh_tun_confirm(struct ssh *ssh, int id, int success, void *arg) 1816 { 1817 if (!success) { 1818 error("Tunnel forwarding failed"); 1819 if (options.exit_on_forward_failure) 1820 cleanup_exit(255); 1821 } 1822 1823 debug("%s: tunnel forward established, id=%d", __func__, id); 1824 forwarding_success(); 1825 } 1826 1827 static void 1828 ssh_init_stdio_forwarding(struct ssh *ssh) 1829 { 1830 Channel *c; 1831 int in, out; 1832 1833 if (options.stdio_forward_host == NULL) 1834 return; 1835 1836 debug3("%s: %s:%d", __func__, options.stdio_forward_host, 1837 options.stdio_forward_port); 1838 1839 if ((in = dup(STDIN_FILENO)) == -1 || 1840 (out = dup(STDOUT_FILENO)) == -1) 1841 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1842 if ((c = channel_connect_stdio_fwd(ssh, options.stdio_forward_host, 1843 options.stdio_forward_port, in, out)) == NULL) 1844 fatal("%s: channel_connect_stdio_fwd failed", __func__); 1845 channel_register_cleanup(ssh, c->self, client_cleanup_stdio_fwd, 0); 1846 channel_register_open_confirm(ssh, c->self, ssh_stdio_confirm, NULL); 1847 } 1848 1849 static void 1850 ssh_init_forwarding(struct ssh *ssh, char **ifname) 1851 { 1852 int success = 0; 1853 int i; 1854 1855 if (options.exit_on_forward_failure) 1856 forward_confirms_pending = 0; /* track pending requests */ 1857 /* Initiate local TCP/IP port forwardings. */ 1858 for (i = 0; i < options.num_local_forwards; i++) { 1859 debug("Local connections to %.200s:%d forwarded to remote " 1860 "address %.200s:%d", 1861 (options.local_forwards[i].listen_path != NULL) ? 1862 options.local_forwards[i].listen_path : 1863 (options.local_forwards[i].listen_host == NULL) ? 1864 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") : 1865 options.local_forwards[i].listen_host, 1866 options.local_forwards[i].listen_port, 1867 (options.local_forwards[i].connect_path != NULL) ? 1868 options.local_forwards[i].connect_path : 1869 options.local_forwards[i].connect_host, 1870 options.local_forwards[i].connect_port); 1871 success += channel_setup_local_fwd_listener(ssh, 1872 &options.local_forwards[i], &options.fwd_opts); 1873 } 1874 if (i > 0 && success != i && options.exit_on_forward_failure) 1875 fatal("Could not request local forwarding."); 1876 if (i > 0 && success == 0) 1877 error("Could not request local forwarding."); 1878 1879 /* Initiate remote TCP/IP port forwardings. */ 1880 for (i = 0; i < options.num_remote_forwards; i++) { 1881 debug("Remote connections from %.200s:%d forwarded to " 1882 "local address %.200s:%d", 1883 (options.remote_forwards[i].listen_path != NULL) ? 1884 options.remote_forwards[i].listen_path : 1885 (options.remote_forwards[i].listen_host == NULL) ? 1886 "LOCALHOST" : options.remote_forwards[i].listen_host, 1887 options.remote_forwards[i].listen_port, 1888 (options.remote_forwards[i].connect_path != NULL) ? 1889 options.remote_forwards[i].connect_path : 1890 options.remote_forwards[i].connect_host, 1891 options.remote_forwards[i].connect_port); 1892 if ((options.remote_forwards[i].handle = 1893 channel_request_remote_forwarding(ssh, 1894 &options.remote_forwards[i])) >= 0) { 1895 client_register_global_confirm( 1896 ssh_confirm_remote_forward, 1897 &options.remote_forwards[i]); 1898 forward_confirms_pending++; 1899 } else if (options.exit_on_forward_failure) 1900 fatal("Could not request remote forwarding."); 1901 else 1902 logit("Warning: Could not request remote forwarding."); 1903 } 1904 1905 /* Initiate tunnel forwarding. */ 1906 if (options.tun_open != SSH_TUNMODE_NO) { 1907 if ((*ifname = client_request_tun_fwd(ssh, 1908 options.tun_open, options.tun_local, 1909 options.tun_remote, ssh_tun_confirm, NULL)) != NULL) 1910 forward_confirms_pending++; 1911 else if (options.exit_on_forward_failure) 1912 fatal("Could not request tunnel forwarding."); 1913 else 1914 error("Could not request tunnel forwarding."); 1915 } 1916 if (forward_confirms_pending > 0) { 1917 debug("%s: expecting replies for %d forwards", __func__, 1918 forward_confirms_pending); 1919 } 1920 } 1921 1922 static void 1923 check_agent_present(void) 1924 { 1925 int r; 1926 1927 if (options.forward_agent) { 1928 /* Clear agent forwarding if we don't have an agent. */ 1929 if ((r = ssh_get_authentication_socket(NULL)) != 0) { 1930 options.forward_agent = 0; 1931 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1932 debug("ssh_get_authentication_socket: %s", 1933 ssh_err(r)); 1934 } 1935 } 1936 } 1937 1938 static void 1939 ssh_session2_setup(struct ssh *ssh, int id, int success, void *arg) 1940 { 1941 extern char **environ; 1942 const char *display; 1943 int r, interactive = tty_flag; 1944 char *proto = NULL, *data = NULL; 1945 1946 if (!success) 1947 return; /* No need for error message, channels code sens one */ 1948 1949 display = getenv("DISPLAY"); 1950 if (display == NULL && options.forward_x11) 1951 debug("X11 forwarding requested but DISPLAY not set"); 1952 if (options.forward_x11 && client_x11_get_proto(ssh, display, 1953 options.xauth_location, options.forward_x11_trusted, 1954 options.forward_x11_timeout, &proto, &data) == 0) { 1955 /* Request forwarding with authentication spoofing. */ 1956 debug("Requesting X11 forwarding with authentication " 1957 "spoofing."); 1958 x11_request_forwarding_with_spoofing(ssh, id, display, proto, 1959 data, 1); 1960 client_expect_confirm(ssh, id, "X11 forwarding", CONFIRM_WARN); 1961 /* XXX exit_on_forward_failure */ 1962 interactive = 1; 1963 } 1964 1965 check_agent_present(); 1966 if (options.forward_agent) { 1967 debug("Requesting authentication agent forwarding."); 1968 channel_request_start(ssh, id, "auth-agent-req@openssh.com", 0); 1969 if ((r = sshpkt_send(ssh)) != 0) 1970 fatal("%s: %s", __func__, ssh_err(r)); 1971 } 1972 1973 /* Tell the packet module whether this is an interactive session. */ 1974 ssh_packet_set_interactive(ssh, interactive, 1975 options.ip_qos_interactive, options.ip_qos_bulk); 1976 1977 client_session2_setup(ssh, id, tty_flag, subsystem_flag, getenv("TERM"), 1978 NULL, fileno(stdin), command, environ); 1979 } 1980 1981 /* open new channel for a session */ 1982 static int 1983 ssh_session2_open(struct ssh *ssh) 1984 { 1985 Channel *c; 1986 int window, packetmax, in, out, err; 1987 1988 if (stdin_null_flag) { 1989 in = open(_PATH_DEVNULL, O_RDONLY); 1990 } else { 1991 in = dup(STDIN_FILENO); 1992 } 1993 out = dup(STDOUT_FILENO); 1994 err = dup(STDERR_FILENO); 1995 1996 if (in == -1 || out == -1 || err == -1) 1997 fatal("dup() in/out/err failed"); 1998 1999 /* enable nonblocking unless tty */ 2000 if (!isatty(in)) 2001 set_nonblock(in); 2002 if (!isatty(out)) 2003 set_nonblock(out); 2004 if (!isatty(err)) 2005 set_nonblock(err); 2006 2007 window = CHAN_SES_WINDOW_DEFAULT; 2008 packetmax = CHAN_SES_PACKET_DEFAULT; 2009 if (tty_flag) { 2010 window >>= 1; 2011 packetmax >>= 1; 2012 } 2013 c = channel_new(ssh, 2014 "session", SSH_CHANNEL_OPENING, in, out, err, 2015 window, packetmax, CHAN_EXTENDED_WRITE, 2016 "client-session", /*nonblock*/0); 2017 2018 debug3("%s: channel_new: %d", __func__, c->self); 2019 2020 channel_send_open(ssh, c->self); 2021 if (!no_shell_flag) 2022 channel_register_open_confirm(ssh, c->self, 2023 ssh_session2_setup, NULL); 2024 2025 return c->self; 2026 } 2027 2028 static int 2029 ssh_session2(struct ssh *ssh, struct passwd *pw) 2030 { 2031 int r, devnull, id = -1; 2032 char *cp, *tun_fwd_ifname = NULL; 2033 2034 /* XXX should be pre-session */ 2035 if (!options.control_persist) 2036 ssh_init_stdio_forwarding(ssh); 2037 2038 ssh_init_forwarding(ssh, &tun_fwd_ifname); 2039 2040 if (options.local_command != NULL) { 2041 debug3("expanding LocalCommand: %s", options.local_command); 2042 cp = options.local_command; 2043 options.local_command = percent_expand(cp, 2044 DEFAULT_CLIENT_PERCENT_EXPAND_ARGS, 2045 "d", pw->pw_dir, 2046 "h", host, 2047 "r", options.user, 2048 "u", pw->pw_name, 2049 "T", tun_fwd_ifname == NULL ? "NONE" : tun_fwd_ifname, 2050 (char *)NULL); 2051 debug3("expanded LocalCommand: %s", options.local_command); 2052 free(cp); 2053 } 2054 2055 /* Start listening for multiplex clients */ 2056 if (!ssh_packet_get_mux(ssh)) 2057 muxserver_listen(ssh); 2058 2059 /* 2060 * If we are in control persist mode and have a working mux listen 2061 * socket, then prepare to background ourselves and have a foreground 2062 * client attach as a control slave. 2063 * NB. we must save copies of the flags that we override for 2064 * the backgrounding, since we defer attachment of the slave until 2065 * after the connection is fully established (in particular, 2066 * async rfwd replies have been received for ExitOnForwardFailure). 2067 */ 2068 if (options.control_persist && muxserver_sock != -1) { 2069 ostdin_null_flag = stdin_null_flag; 2070 ono_shell_flag = no_shell_flag; 2071 orequest_tty = options.request_tty; 2072 otty_flag = tty_flag; 2073 stdin_null_flag = 1; 2074 no_shell_flag = 1; 2075 tty_flag = 0; 2076 if (!fork_after_authentication_flag) 2077 need_controlpersist_detach = 1; 2078 fork_after_authentication_flag = 1; 2079 } 2080 /* 2081 * ControlPersist mux listen socket setup failed, attempt the 2082 * stdio forward setup that we skipped earlier. 2083 */ 2084 if (options.control_persist && muxserver_sock == -1) 2085 ssh_init_stdio_forwarding(ssh); 2086 2087 if (!no_shell_flag) 2088 id = ssh_session2_open(ssh); 2089 else { 2090 ssh_packet_set_interactive(ssh, 2091 options.control_master == SSHCTL_MASTER_NO, 2092 options.ip_qos_interactive, options.ip_qos_bulk); 2093 } 2094 2095 /* If we don't expect to open a new session, then disallow it */ 2096 if (options.control_master == SSHCTL_MASTER_NO && 2097 (datafellows & SSH_NEW_OPENSSH)) { 2098 debug("Requesting no-more-sessions@openssh.com"); 2099 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 || 2100 (r = sshpkt_put_cstring(ssh, 2101 "no-more-sessions@openssh.com")) != 0 || 2102 (r = sshpkt_put_u8(ssh, 0)) != 0 || 2103 (r = sshpkt_send(ssh)) != 0) 2104 fatal("%s: %s", __func__, ssh_err(r)); 2105 } 2106 2107 /* Execute a local command */ 2108 if (options.local_command != NULL && 2109 options.permit_local_command) 2110 ssh_local_cmd(options.local_command); 2111 2112 /* 2113 * stdout is now owned by the session channel; clobber it here 2114 * so future channel closes are propagated to the local fd. 2115 * NB. this can only happen after LocalCommand has completed, 2116 * as it may want to write to stdout. 2117 */ 2118 if (!need_controlpersist_detach) { 2119 if ((devnull = open(_PATH_DEVNULL, O_WRONLY)) == -1) 2120 error("%s: open %s: %s", __func__, 2121 _PATH_DEVNULL, strerror(errno)); 2122 if (dup2(devnull, STDOUT_FILENO) == -1) 2123 fatal("%s: dup2() stdout failed", __func__); 2124 if (devnull > STDERR_FILENO) 2125 close(devnull); 2126 } 2127 2128 /* 2129 * If requested and we are not interested in replies to remote 2130 * forwarding requests, then let ssh continue in the background. 2131 */ 2132 if (fork_after_authentication_flag) { 2133 if (options.exit_on_forward_failure && 2134 options.num_remote_forwards > 0) { 2135 debug("deferring postauth fork until remote forward " 2136 "confirmation received"); 2137 } else 2138 fork_postauth(); 2139 } 2140 2141 return client_loop(ssh, tty_flag, tty_flag ? 2142 options.escape_char : SSH_ESCAPECHAR_NONE, id); 2143 } 2144 2145 /* Loads all IdentityFile and CertificateFile keys */ 2146 static void 2147 load_public_identity_files(struct passwd *pw) 2148 { 2149 char *filename, *cp; 2150 struct sshkey *public; 2151 int i; 2152 u_int n_ids, n_certs; 2153 char *identity_files[SSH_MAX_IDENTITY_FILES]; 2154 struct sshkey *identity_keys[SSH_MAX_IDENTITY_FILES]; 2155 int identity_file_userprovided[SSH_MAX_IDENTITY_FILES]; 2156 char *certificate_files[SSH_MAX_CERTIFICATE_FILES]; 2157 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES]; 2158 int certificate_file_userprovided[SSH_MAX_CERTIFICATE_FILES]; 2159 #ifdef ENABLE_PKCS11 2160 struct sshkey **keys = NULL; 2161 char **comments = NULL; 2162 int nkeys; 2163 #endif /* PKCS11 */ 2164 2165 n_ids = n_certs = 0; 2166 memset(identity_files, 0, sizeof(identity_files)); 2167 memset(identity_keys, 0, sizeof(identity_keys)); 2168 memset(identity_file_userprovided, 0, 2169 sizeof(identity_file_userprovided)); 2170 memset(certificate_files, 0, sizeof(certificate_files)); 2171 memset(certificates, 0, sizeof(certificates)); 2172 memset(certificate_file_userprovided, 0, 2173 sizeof(certificate_file_userprovided)); 2174 2175 #ifdef ENABLE_PKCS11 2176 if (options.pkcs11_provider != NULL && 2177 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 2178 (pkcs11_init(!options.batch_mode) == 0) && 2179 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 2180 &keys, &comments)) > 0) { 2181 for (i = 0; i < nkeys; i++) { 2182 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 2183 sshkey_free(keys[i]); 2184 free(comments[i]); 2185 continue; 2186 } 2187 identity_keys[n_ids] = keys[i]; 2188 identity_files[n_ids] = comments[i]; /* transferred */ 2189 n_ids++; 2190 } 2191 free(keys); 2192 free(comments); 2193 } 2194 #endif /* ENABLE_PKCS11 */ 2195 for (i = 0; i < options.num_identity_files; i++) { 2196 if (n_ids >= SSH_MAX_IDENTITY_FILES || 2197 strcasecmp(options.identity_files[i], "none") == 0) { 2198 free(options.identity_files[i]); 2199 options.identity_files[i] = NULL; 2200 continue; 2201 } 2202 cp = tilde_expand_filename(options.identity_files[i], getuid()); 2203 filename = default_client_percent_dollar_expand(cp, 2204 pw->pw_dir, host, options.user, pw->pw_name); 2205 free(cp); 2206 check_load(sshkey_load_public(filename, &public, NULL), 2207 filename, "pubkey"); 2208 debug("identity file %s type %d", filename, 2209 public ? public->type : -1); 2210 free(options.identity_files[i]); 2211 identity_files[n_ids] = filename; 2212 identity_keys[n_ids] = public; 2213 identity_file_userprovided[n_ids] = 2214 options.identity_file_userprovided[i]; 2215 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 2216 continue; 2217 2218 /* 2219 * If no certificates have been explicitly listed then try 2220 * to add the default certificate variant too. 2221 */ 2222 if (options.num_certificate_files != 0) 2223 continue; 2224 xasprintf(&cp, "%s-cert", filename); 2225 check_load(sshkey_load_public(cp, &public, NULL), 2226 filename, "pubkey"); 2227 debug("identity file %s type %d", cp, 2228 public ? public->type : -1); 2229 if (public == NULL) { 2230 free(cp); 2231 continue; 2232 } 2233 if (!sshkey_is_cert(public)) { 2234 debug("%s: key %s type %s is not a certificate", 2235 __func__, cp, sshkey_type(public)); 2236 sshkey_free(public); 2237 free(cp); 2238 continue; 2239 } 2240 /* NB. leave filename pointing to private key */ 2241 identity_files[n_ids] = xstrdup(filename); 2242 identity_keys[n_ids] = public; 2243 identity_file_userprovided[n_ids] = 2244 options.identity_file_userprovided[i]; 2245 n_ids++; 2246 } 2247 2248 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES) 2249 fatal("%s: too many certificates", __func__); 2250 for (i = 0; i < options.num_certificate_files; i++) { 2251 cp = tilde_expand_filename(options.certificate_files[i], 2252 getuid()); 2253 filename = default_client_percent_dollar_expand(cp, 2254 pw->pw_dir, host, options.user, pw->pw_name); 2255 free(cp); 2256 2257 check_load(sshkey_load_public(filename, &public, NULL), 2258 filename, "certificate"); 2259 debug("certificate file %s type %d", filename, 2260 public ? public->type : -1); 2261 free(options.certificate_files[i]); 2262 options.certificate_files[i] = NULL; 2263 if (public == NULL) { 2264 free(filename); 2265 continue; 2266 } 2267 if (!sshkey_is_cert(public)) { 2268 debug("%s: key %s type %s is not a certificate", 2269 __func__, filename, sshkey_type(public)); 2270 sshkey_free(public); 2271 free(filename); 2272 continue; 2273 } 2274 certificate_files[n_certs] = filename; 2275 certificates[n_certs] = public; 2276 certificate_file_userprovided[n_certs] = 2277 options.certificate_file_userprovided[i]; 2278 ++n_certs; 2279 } 2280 2281 options.num_identity_files = n_ids; 2282 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 2283 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 2284 memcpy(options.identity_file_userprovided, 2285 identity_file_userprovided, sizeof(identity_file_userprovided)); 2286 2287 options.num_certificate_files = n_certs; 2288 memcpy(options.certificate_files, 2289 certificate_files, sizeof(certificate_files)); 2290 memcpy(options.certificates, certificates, sizeof(certificates)); 2291 memcpy(options.certificate_file_userprovided, 2292 certificate_file_userprovided, 2293 sizeof(certificate_file_userprovided)); 2294 } 2295 2296 static void 2297 main_sigchld_handler(int sig) 2298 { 2299 int save_errno = errno; 2300 pid_t pid; 2301 int status; 2302 2303 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 2304 (pid == -1 && errno == EINTR)) 2305 ; 2306 errno = save_errno; 2307 } 2308