1 /* $OpenBSD: ssh.c,v 1.448 2016/12/06 07:48:01 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * Ssh client program. This program can be used to log into a remote machine. 7 * The software supports strong authentication, encryption, and forwarding 8 * of X11, TCP/IP, and authentication connections. 9 * 10 * As far as I am concerned, the code I have written for this software 11 * can be used freely for any purpose. Any derived versions of this 12 * software must be clearly marked as such, and if the derived work is 13 * incompatible with the protocol description in the RFC file, it must be 14 * called by a name other than "ssh" or "Secure Shell". 15 * 16 * Copyright (c) 1999 Niels Provos. All rights reserved. 17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved. 18 * 19 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu> 20 * in Canada (German citizen). 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the above copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 41 */ 42 43 #include <sys/types.h> 44 #include <sys/ioctl.h> 45 #include <sys/queue.h> 46 #include <sys/resource.h> 47 #include <sys/socket.h> 48 #include <sys/stat.h> 49 #include <sys/time.h> 50 #include <sys/wait.h> 51 52 #include <ctype.h> 53 #include <errno.h> 54 #include <fcntl.h> 55 #include <netdb.h> 56 #include <paths.h> 57 #include <pwd.h> 58 #include <signal.h> 59 #include <stddef.h> 60 #include <stdio.h> 61 #include <stdlib.h> 62 #include <string.h> 63 #include <unistd.h> 64 #include <limits.h> 65 #include <locale.h> 66 67 #ifdef WITH_OPENSSL 68 #include <openssl/evp.h> 69 #include <openssl/err.h> 70 #endif 71 72 #include "xmalloc.h" 73 #include "ssh.h" 74 #include "ssh1.h" 75 #include "ssh2.h" 76 #include "canohost.h" 77 #include "compat.h" 78 #include "cipher.h" 79 #include "digest.h" 80 #include "packet.h" 81 #include "buffer.h" 82 #include "channels.h" 83 #include "key.h" 84 #include "authfd.h" 85 #include "authfile.h" 86 #include "pathnames.h" 87 #include "dispatch.h" 88 #include "clientloop.h" 89 #include "log.h" 90 #include "misc.h" 91 #include "readconf.h" 92 #include "sshconnect.h" 93 #include "kex.h" 94 #include "mac.h" 95 #include "sshpty.h" 96 #include "match.h" 97 #include "msg.h" 98 #include "uidswap.h" 99 #include "version.h" 100 #include "ssherr.h" 101 #include "myproposal.h" 102 103 #ifdef ENABLE_PKCS11 104 #include "ssh-pkcs11.h" 105 #endif 106 107 extern char *__progname; 108 109 /* Flag indicating whether debug mode is on. May be set on the command line. */ 110 int debug_flag = 0; 111 112 /* Flag indicating whether a tty should be requested */ 113 int tty_flag = 0; 114 115 /* don't exec a shell */ 116 int no_shell_flag = 0; 117 118 /* 119 * Flag indicating that nothing should be read from stdin. This can be set 120 * on the command line. 121 */ 122 int stdin_null_flag = 0; 123 124 /* 125 * Flag indicating that the current process should be backgrounded and 126 * a new slave launched in the foreground for ControlPersist. 127 */ 128 int need_controlpersist_detach = 0; 129 130 /* Copies of flags for ControlPersist foreground slave */ 131 int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty; 132 133 /* 134 * Flag indicating that ssh should fork after authentication. This is useful 135 * so that the passphrase can be entered manually, and then ssh goes to the 136 * background. 137 */ 138 int fork_after_authentication_flag = 0; 139 140 /* 141 * General data structure for command line options and options configurable 142 * in configuration files. See readconf.h. 143 */ 144 Options options; 145 146 /* optional user configfile */ 147 char *config = NULL; 148 149 /* 150 * Name of the host we are connecting to. This is the name given on the 151 * command line, or the HostName specified for the user-supplied name in a 152 * configuration file. 153 */ 154 char *host; 155 156 /* socket address the host resolves to */ 157 struct sockaddr_storage hostaddr; 158 159 /* Private host keys. */ 160 Sensitive sensitive_data; 161 162 /* Original real UID. */ 163 uid_t original_real_uid; 164 uid_t original_effective_uid; 165 166 /* command to be executed */ 167 Buffer command; 168 169 /* Should we execute a command or invoke a subsystem? */ 170 int subsystem_flag = 0; 171 172 /* # of replies received for global requests */ 173 static int remote_forward_confirms_received = 0; 174 175 /* mux.c */ 176 extern int muxserver_sock; 177 extern u_int muxclient_command; 178 179 /* Prints a help message to the user. This function never returns. */ 180 181 static void 182 usage(void) 183 { 184 fprintf(stderr, 185 "usage: ssh [-1246AaCfGgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n" 186 " [-D [bind_address:]port] [-E log_file] [-e escape_char]\n" 187 " [-F configfile] [-I pkcs11] [-i identity_file]\n" 188 " [-J [user@]host[:port]] [-L address] [-l login_name] [-m mac_spec]\n" 189 " [-O ctl_cmd] [-o option] [-p port] [-Q query_option] [-R address]\n" 190 " [-S ctl_path] [-W host:port] [-w local_tun[:remote_tun]]\n" 191 " [user@]hostname [command]\n" 192 ); 193 exit(255); 194 } 195 196 static int ssh_session(void); 197 static int ssh_session2(void); 198 static void load_public_identity_files(void); 199 static void main_sigchld_handler(int); 200 201 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 202 static void 203 tilde_expand_paths(char **paths, u_int num_paths) 204 { 205 u_int i; 206 char *cp; 207 208 for (i = 0; i < num_paths; i++) { 209 cp = tilde_expand_filename(paths[i], original_real_uid); 210 free(paths[i]); 211 paths[i] = cp; 212 } 213 } 214 215 /* 216 * Attempt to resolve a host name / port to a set of addresses and 217 * optionally return any CNAMEs encountered along the way. 218 * Returns NULL on failure. 219 * NB. this function must operate with a options having undefined members. 220 */ 221 static struct addrinfo * 222 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen) 223 { 224 char strport[NI_MAXSERV]; 225 struct addrinfo hints, *res; 226 int gaierr, loglevel = SYSLOG_LEVEL_DEBUG1; 227 228 if (port <= 0) 229 port = default_ssh_port(); 230 231 snprintf(strport, sizeof strport, "%d", port); 232 memset(&hints, 0, sizeof(hints)); 233 hints.ai_family = options.address_family == -1 ? 234 AF_UNSPEC : options.address_family; 235 hints.ai_socktype = SOCK_STREAM; 236 if (cname != NULL) 237 hints.ai_flags = AI_CANONNAME; 238 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 239 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) 240 loglevel = SYSLOG_LEVEL_ERROR; 241 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", 242 __progname, name, ssh_gai_strerror(gaierr)); 243 return NULL; 244 } 245 if (cname != NULL && res->ai_canonname != NULL) { 246 if (strlcpy(cname, res->ai_canonname, clen) >= clen) { 247 error("%s: host \"%s\" cname \"%s\" too long (max %lu)", 248 __func__, name, res->ai_canonname, (u_long)clen); 249 if (clen > 0) 250 *cname = '\0'; 251 } 252 } 253 return res; 254 } 255 256 /* 257 * Attempt to resolve a numeric host address / port to a single address. 258 * Returns a canonical address string. 259 * Returns NULL on failure. 260 * NB. this function must operate with a options having undefined members. 261 */ 262 static struct addrinfo * 263 resolve_addr(const char *name, int port, char *caddr, size_t clen) 264 { 265 char addr[NI_MAXHOST], strport[NI_MAXSERV]; 266 struct addrinfo hints, *res; 267 int gaierr; 268 269 if (port <= 0) 270 port = default_ssh_port(); 271 snprintf(strport, sizeof strport, "%u", port); 272 memset(&hints, 0, sizeof(hints)); 273 hints.ai_family = options.address_family == -1 ? 274 AF_UNSPEC : options.address_family; 275 hints.ai_socktype = SOCK_STREAM; 276 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 277 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 278 debug2("%s: could not resolve name %.100s as address: %s", 279 __func__, name, ssh_gai_strerror(gaierr)); 280 return NULL; 281 } 282 if (res == NULL) { 283 debug("%s: getaddrinfo %.100s returned no addresses", 284 __func__, name); 285 return NULL; 286 } 287 if (res->ai_next != NULL) { 288 debug("%s: getaddrinfo %.100s returned multiple addresses", 289 __func__, name); 290 goto fail; 291 } 292 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen, 293 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) { 294 debug("%s: Could not format address for name %.100s: %s", 295 __func__, name, ssh_gai_strerror(gaierr)); 296 goto fail; 297 } 298 if (strlcpy(caddr, addr, clen) >= clen) { 299 error("%s: host \"%s\" addr \"%s\" too long (max %lu)", 300 __func__, name, addr, (u_long)clen); 301 if (clen > 0) 302 *caddr = '\0'; 303 fail: 304 freeaddrinfo(res); 305 return NULL; 306 } 307 return res; 308 } 309 310 /* 311 * Check whether the cname is a permitted replacement for the hostname 312 * and perform the replacement if it is. 313 * NB. this function must operate with a options having undefined members. 314 */ 315 static int 316 check_follow_cname(int direct, char **namep, const char *cname) 317 { 318 int i; 319 struct allowed_cname *rule; 320 321 if (*cname == '\0' || options.num_permitted_cnames == 0 || 322 strcmp(*namep, cname) == 0) 323 return 0; 324 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 325 return 0; 326 /* 327 * Don't attempt to canonicalize names that will be interpreted by 328 * a proxy or jump host unless the user specifically requests so. 329 */ 330 if (!direct && 331 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 332 return 0; 333 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname); 334 for (i = 0; i < options.num_permitted_cnames; i++) { 335 rule = options.permitted_cnames + i; 336 if (match_pattern_list(*namep, rule->source_list, 1) != 1 || 337 match_pattern_list(cname, rule->target_list, 1) != 1) 338 continue; 339 verbose("Canonicalized DNS aliased hostname " 340 "\"%s\" => \"%s\"", *namep, cname); 341 free(*namep); 342 *namep = xstrdup(cname); 343 return 1; 344 } 345 return 0; 346 } 347 348 /* 349 * Attempt to resolve the supplied hostname after applying the user's 350 * canonicalization rules. Returns the address list for the host or NULL 351 * if no name was found after canonicalization. 352 * NB. this function must operate with a options having undefined members. 353 */ 354 static struct addrinfo * 355 resolve_canonicalize(char **hostp, int port) 356 { 357 int i, direct, ndots; 358 char *cp, *fullhost, newname[NI_MAXHOST]; 359 struct addrinfo *addrs; 360 361 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 362 return NULL; 363 364 /* 365 * Don't attempt to canonicalize names that will be interpreted by 366 * a proxy unless the user specifically requests so. 367 */ 368 direct = option_clear_or_none(options.proxy_command) && 369 options.jump_host == NULL; 370 if (!direct && 371 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 372 return NULL; 373 374 /* Try numeric hostnames first */ 375 if ((addrs = resolve_addr(*hostp, port, 376 newname, sizeof(newname))) != NULL) { 377 debug2("%s: hostname %.100s is address", __func__, *hostp); 378 if (strcasecmp(*hostp, newname) != 0) { 379 debug2("%s: canonicalised address \"%s\" => \"%s\"", 380 __func__, *hostp, newname); 381 free(*hostp); 382 *hostp = xstrdup(newname); 383 } 384 return addrs; 385 } 386 387 /* If domain name is anchored, then resolve it now */ 388 if ((*hostp)[strlen(*hostp) - 1] == '.') { 389 debug3("%s: name is fully qualified", __func__); 390 fullhost = xstrdup(*hostp); 391 if ((addrs = resolve_host(fullhost, port, 0, 392 newname, sizeof(newname))) != NULL) 393 goto found; 394 free(fullhost); 395 goto notfound; 396 } 397 398 /* Don't apply canonicalization to sufficiently-qualified hostnames */ 399 ndots = 0; 400 for (cp = *hostp; *cp != '\0'; cp++) { 401 if (*cp == '.') 402 ndots++; 403 } 404 if (ndots > options.canonicalize_max_dots) { 405 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)", 406 __func__, *hostp, options.canonicalize_max_dots); 407 return NULL; 408 } 409 /* Attempt each supplied suffix */ 410 for (i = 0; i < options.num_canonical_domains; i++) { 411 *newname = '\0'; 412 xasprintf(&fullhost, "%s.%s.", *hostp, 413 options.canonical_domains[i]); 414 debug3("%s: attempting \"%s\" => \"%s\"", __func__, 415 *hostp, fullhost); 416 if ((addrs = resolve_host(fullhost, port, 0, 417 newname, sizeof(newname))) == NULL) { 418 free(fullhost); 419 continue; 420 } 421 found: 422 /* Remove trailing '.' */ 423 fullhost[strlen(fullhost) - 1] = '\0'; 424 /* Follow CNAME if requested */ 425 if (!check_follow_cname(direct, &fullhost, newname)) { 426 debug("Canonicalized hostname \"%s\" => \"%s\"", 427 *hostp, fullhost); 428 } 429 free(*hostp); 430 *hostp = fullhost; 431 return addrs; 432 } 433 notfound: 434 if (!options.canonicalize_fallback_local) 435 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); 436 debug2("%s: host %s not found in any suffix", __func__, *hostp); 437 return NULL; 438 } 439 440 /* 441 * Read per-user configuration file. Ignore the system wide config 442 * file if the user specifies a config file on the command line. 443 */ 444 static void 445 process_config_files(const char *host_arg, struct passwd *pw, int post_canon) 446 { 447 char buf[PATH_MAX]; 448 int r; 449 450 if (config != NULL) { 451 if (strcasecmp(config, "none") != 0 && 452 !read_config_file(config, pw, host, host_arg, &options, 453 SSHCONF_USERCONF | (post_canon ? SSHCONF_POSTCANON : 0))) 454 fatal("Can't open user config file %.100s: " 455 "%.100s", config, strerror(errno)); 456 } else { 457 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 458 _PATH_SSH_USER_CONFFILE); 459 if (r > 0 && (size_t)r < sizeof(buf)) 460 (void)read_config_file(buf, pw, host, host_arg, 461 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF | 462 (post_canon ? SSHCONF_POSTCANON : 0)); 463 464 /* Read systemwide configuration file after user config. */ 465 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, 466 host, host_arg, &options, 467 post_canon ? SSHCONF_POSTCANON : 0); 468 } 469 } 470 471 /* Rewrite the port number in an addrinfo list of addresses */ 472 static void 473 set_addrinfo_port(struct addrinfo *addrs, int port) 474 { 475 struct addrinfo *addr; 476 477 for (addr = addrs; addr != NULL; addr = addr->ai_next) { 478 switch (addr->ai_family) { 479 case AF_INET: 480 ((struct sockaddr_in *)addr->ai_addr)-> 481 sin_port = htons(port); 482 break; 483 case AF_INET6: 484 ((struct sockaddr_in6 *)addr->ai_addr)-> 485 sin6_port = htons(port); 486 break; 487 } 488 } 489 } 490 491 /* 492 * Main program for the ssh client. 493 */ 494 int 495 main(int ac, char **av) 496 { 497 struct ssh *ssh = NULL; 498 int i, r, opt, exit_status, use_syslog, direct, config_test = 0; 499 char *p, *cp, *line, *argv0, buf[PATH_MAX], *host_arg, *logfile; 500 char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 501 char cname[NI_MAXHOST], uidstr[32], *conn_hash_hex; 502 struct stat st; 503 struct passwd *pw; 504 int timeout_ms; 505 extern int optind, optreset; 506 extern char *optarg; 507 struct Forward fwd; 508 struct addrinfo *addrs = NULL; 509 struct ssh_digest_ctx *md; 510 u_char conn_hash[SSH_DIGEST_MAX_LENGTH]; 511 512 ssh_malloc_init(); /* must be called before any mallocs */ 513 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 514 sanitise_stdfd(); 515 516 /* 517 * Discard other fds that are hanging around. These can cause problem 518 * with backgrounded ssh processes started by ControlPersist. 519 */ 520 closefrom(STDERR_FILENO + 1); 521 522 /* 523 * Save the original real uid. It will be needed later (uid-swapping 524 * may clobber the real uid). 525 */ 526 original_real_uid = getuid(); 527 original_effective_uid = geteuid(); 528 529 /* 530 * Use uid-swapping to give up root privileges for the duration of 531 * option processing. We will re-instantiate the rights when we are 532 * ready to create the privileged port, and will permanently drop 533 * them when the port has been created (actually, when the connection 534 * has been made, as we may need to create the port several times). 535 */ 536 PRIV_END; 537 538 /* If we are installed setuid root be careful to not drop core. */ 539 if (original_real_uid != original_effective_uid) { 540 struct rlimit rlim; 541 rlim.rlim_cur = rlim.rlim_max = 0; 542 if (setrlimit(RLIMIT_CORE, &rlim) < 0) 543 fatal("setrlimit failed: %.100s", strerror(errno)); 544 } 545 /* Get user data. */ 546 pw = getpwuid(original_real_uid); 547 if (!pw) { 548 logit("No user exists for uid %lu", (u_long)original_real_uid); 549 exit(255); 550 } 551 /* Take a copy of the returned structure. */ 552 pw = pwcopy(pw); 553 554 /* 555 * Set our umask to something reasonable, as some files are created 556 * with the default umask. This will make them world-readable but 557 * writable only by the owner, which is ok for all files for which we 558 * don't set the modes explicitly. 559 */ 560 umask(022); 561 562 setlocale(LC_CTYPE, ""); 563 564 /* 565 * Initialize option structure to indicate that no values have been 566 * set. 567 */ 568 initialize_options(&options); 569 570 /* Parse command-line arguments. */ 571 host = NULL; 572 use_syslog = 0; 573 logfile = NULL; 574 argv0 = av[0]; 575 576 again: 577 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 578 "ACD:E:F:GI:J:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { 579 switch (opt) { 580 case '1': 581 options.protocol = SSH_PROTO_1; 582 break; 583 case '2': 584 options.protocol = SSH_PROTO_2; 585 break; 586 case '4': 587 options.address_family = AF_INET; 588 break; 589 case '6': 590 options.address_family = AF_INET6; 591 break; 592 case 'n': 593 stdin_null_flag = 1; 594 break; 595 case 'f': 596 fork_after_authentication_flag = 1; 597 stdin_null_flag = 1; 598 break; 599 case 'x': 600 options.forward_x11 = 0; 601 break; 602 case 'X': 603 options.forward_x11 = 1; 604 break; 605 case 'y': 606 use_syslog = 1; 607 break; 608 case 'E': 609 logfile = optarg; 610 break; 611 case 'G': 612 config_test = 1; 613 break; 614 case 'Y': 615 options.forward_x11 = 1; 616 options.forward_x11_trusted = 1; 617 break; 618 case 'g': 619 options.fwd_opts.gateway_ports = 1; 620 break; 621 case 'O': 622 if (options.stdio_forward_host != NULL) 623 fatal("Cannot specify multiplexing " 624 "command with -W"); 625 else if (muxclient_command != 0) 626 fatal("Multiplexing command already specified"); 627 if (strcmp(optarg, "check") == 0) 628 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 629 else if (strcmp(optarg, "forward") == 0) 630 muxclient_command = SSHMUX_COMMAND_FORWARD; 631 else if (strcmp(optarg, "exit") == 0) 632 muxclient_command = SSHMUX_COMMAND_TERMINATE; 633 else if (strcmp(optarg, "stop") == 0) 634 muxclient_command = SSHMUX_COMMAND_STOP; 635 else if (strcmp(optarg, "cancel") == 0) 636 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 637 else if (strcmp(optarg, "proxy") == 0) 638 muxclient_command = SSHMUX_COMMAND_PROXY; 639 else 640 fatal("Invalid multiplex command."); 641 break; 642 case 'P': /* deprecated */ 643 options.use_privileged_port = 0; 644 break; 645 case 'Q': 646 cp = NULL; 647 if (strcmp(optarg, "cipher") == 0) 648 cp = cipher_alg_list('\n', 0); 649 else if (strcmp(optarg, "cipher-auth") == 0) 650 cp = cipher_alg_list('\n', 1); 651 else if (strcmp(optarg, "mac") == 0) 652 cp = mac_alg_list('\n'); 653 else if (strcmp(optarg, "kex") == 0) 654 cp = kex_alg_list('\n'); 655 else if (strcmp(optarg, "key") == 0) 656 cp = sshkey_alg_list(0, 0, '\n'); 657 else if (strcmp(optarg, "key-cert") == 0) 658 cp = sshkey_alg_list(1, 0, '\n'); 659 else if (strcmp(optarg, "key-plain") == 0) 660 cp = sshkey_alg_list(0, 1, '\n'); 661 else if (strcmp(optarg, "protocol-version") == 0) { 662 #ifdef WITH_SSH1 663 cp = xstrdup("1\n2"); 664 #else 665 cp = xstrdup("2"); 666 #endif 667 } 668 if (cp == NULL) 669 fatal("Unsupported query \"%s\"", optarg); 670 printf("%s\n", cp); 671 free(cp); 672 exit(0); 673 break; 674 case 'a': 675 options.forward_agent = 0; 676 break; 677 case 'A': 678 options.forward_agent = 1; 679 break; 680 case 'k': 681 options.gss_deleg_creds = 0; 682 break; 683 case 'K': 684 options.gss_authentication = 1; 685 options.gss_deleg_creds = 1; 686 break; 687 case 'i': 688 p = tilde_expand_filename(optarg, original_real_uid); 689 if (stat(p, &st) < 0) 690 fprintf(stderr, "Warning: Identity file %s " 691 "not accessible: %s.\n", p, 692 strerror(errno)); 693 else 694 add_identity_file(&options, NULL, p, 1); 695 free(p); 696 break; 697 case 'I': 698 #ifdef ENABLE_PKCS11 699 free(options.pkcs11_provider); 700 options.pkcs11_provider = xstrdup(optarg); 701 #else 702 fprintf(stderr, "no support for PKCS#11.\n"); 703 #endif 704 break; 705 case 'J': 706 if (options.jump_host != NULL) 707 fatal("Only a single -J option permitted"); 708 if (options.proxy_command != NULL) 709 fatal("Cannot specify -J with ProxyCommand"); 710 if (parse_jump(optarg, &options, 1) == -1) 711 fatal("Invalid -J argument"); 712 options.proxy_command = xstrdup("none"); 713 break; 714 case 't': 715 if (options.request_tty == REQUEST_TTY_YES) 716 options.request_tty = REQUEST_TTY_FORCE; 717 else 718 options.request_tty = REQUEST_TTY_YES; 719 break; 720 case 'v': 721 if (debug_flag == 0) { 722 debug_flag = 1; 723 options.log_level = SYSLOG_LEVEL_DEBUG1; 724 } else { 725 if (options.log_level < SYSLOG_LEVEL_DEBUG3) { 726 debug_flag++; 727 options.log_level++; 728 } 729 } 730 break; 731 case 'V': 732 fprintf(stderr, "%s, %s\n", 733 SSH_VERSION, 734 #ifdef WITH_OPENSSL 735 SSLeay_version(SSLEAY_VERSION) 736 #else 737 "without OpenSSL" 738 #endif 739 ); 740 if (opt == 'V') 741 exit(0); 742 break; 743 case 'w': 744 if (options.tun_open == -1) 745 options.tun_open = SSH_TUNMODE_DEFAULT; 746 options.tun_local = a2tun(optarg, &options.tun_remote); 747 if (options.tun_local == SSH_TUNID_ERR) { 748 fprintf(stderr, 749 "Bad tun device '%s'\n", optarg); 750 exit(255); 751 } 752 break; 753 case 'W': 754 if (options.stdio_forward_host != NULL) 755 fatal("stdio forward already specified"); 756 if (muxclient_command != 0) 757 fatal("Cannot specify stdio forward with -O"); 758 if (parse_forward(&fwd, optarg, 1, 0)) { 759 options.stdio_forward_host = fwd.listen_host; 760 options.stdio_forward_port = fwd.listen_port; 761 free(fwd.connect_host); 762 } else { 763 fprintf(stderr, 764 "Bad stdio forwarding specification '%s'\n", 765 optarg); 766 exit(255); 767 } 768 options.request_tty = REQUEST_TTY_NO; 769 no_shell_flag = 1; 770 break; 771 case 'q': 772 options.log_level = SYSLOG_LEVEL_QUIET; 773 break; 774 case 'e': 775 if (optarg[0] == '^' && optarg[2] == 0 && 776 (u_char) optarg[1] >= 64 && 777 (u_char) optarg[1] < 128) 778 options.escape_char = (u_char) optarg[1] & 31; 779 else if (strlen(optarg) == 1) 780 options.escape_char = (u_char) optarg[0]; 781 else if (strcmp(optarg, "none") == 0) 782 options.escape_char = SSH_ESCAPECHAR_NONE; 783 else { 784 fprintf(stderr, "Bad escape character '%s'.\n", 785 optarg); 786 exit(255); 787 } 788 break; 789 case 'c': 790 if (ciphers_valid(*optarg == '+' ? 791 optarg + 1 : optarg)) { 792 /* SSH2 only */ 793 free(options.ciphers); 794 options.ciphers = xstrdup(optarg); 795 options.cipher = SSH_CIPHER_INVALID; 796 break; 797 } 798 /* SSH1 only */ 799 options.cipher = cipher_number(optarg); 800 if (options.cipher == -1) { 801 fprintf(stderr, "Unknown cipher type '%s'\n", 802 optarg); 803 exit(255); 804 } 805 if (options.cipher == SSH_CIPHER_3DES) 806 options.ciphers = xstrdup("3des-cbc"); 807 else if (options.cipher == SSH_CIPHER_BLOWFISH) 808 options.ciphers = xstrdup("blowfish-cbc"); 809 else 810 options.ciphers = xstrdup(KEX_CLIENT_ENCRYPT); 811 break; 812 case 'm': 813 if (mac_valid(optarg)) { 814 free(options.macs); 815 options.macs = xstrdup(optarg); 816 } else { 817 fprintf(stderr, "Unknown mac type '%s'\n", 818 optarg); 819 exit(255); 820 } 821 break; 822 case 'M': 823 if (options.control_master == SSHCTL_MASTER_YES) 824 options.control_master = SSHCTL_MASTER_ASK; 825 else 826 options.control_master = SSHCTL_MASTER_YES; 827 break; 828 case 'p': 829 options.port = a2port(optarg); 830 if (options.port <= 0) { 831 fprintf(stderr, "Bad port '%s'\n", optarg); 832 exit(255); 833 } 834 break; 835 case 'l': 836 options.user = optarg; 837 break; 838 839 case 'L': 840 if (parse_forward(&fwd, optarg, 0, 0)) 841 add_local_forward(&options, &fwd); 842 else { 843 fprintf(stderr, 844 "Bad local forwarding specification '%s'\n", 845 optarg); 846 exit(255); 847 } 848 break; 849 850 case 'R': 851 if (parse_forward(&fwd, optarg, 0, 1)) { 852 add_remote_forward(&options, &fwd); 853 } else { 854 fprintf(stderr, 855 "Bad remote forwarding specification " 856 "'%s'\n", optarg); 857 exit(255); 858 } 859 break; 860 861 case 'D': 862 if (parse_forward(&fwd, optarg, 1, 0)) { 863 add_local_forward(&options, &fwd); 864 } else { 865 fprintf(stderr, 866 "Bad dynamic forwarding specification " 867 "'%s'\n", optarg); 868 exit(255); 869 } 870 break; 871 872 case 'C': 873 options.compression = 1; 874 break; 875 case 'N': 876 no_shell_flag = 1; 877 options.request_tty = REQUEST_TTY_NO; 878 break; 879 case 'T': 880 options.request_tty = REQUEST_TTY_NO; 881 break; 882 case 'o': 883 line = xstrdup(optarg); 884 if (process_config_line(&options, pw, 885 host ? host : "", host ? host : "", line, 886 "command-line", 0, NULL, SSHCONF_USERCONF) != 0) 887 exit(255); 888 free(line); 889 break; 890 case 's': 891 subsystem_flag = 1; 892 break; 893 case 'S': 894 free(options.control_path); 895 options.control_path = xstrdup(optarg); 896 break; 897 case 'b': 898 options.bind_address = optarg; 899 break; 900 case 'F': 901 config = optarg; 902 break; 903 default: 904 usage(); 905 } 906 } 907 908 ac -= optind; 909 av += optind; 910 911 if (ac > 0 && !host) { 912 if (strrchr(*av, '@')) { 913 p = xstrdup(*av); 914 cp = strrchr(p, '@'); 915 if (cp == NULL || cp == p) 916 usage(); 917 options.user = p; 918 *cp = '\0'; 919 host = xstrdup(++cp); 920 } else 921 host = xstrdup(*av); 922 if (ac > 1) { 923 optind = optreset = 1; 924 goto again; 925 } 926 ac--, av++; 927 } 928 929 /* Check that we got a host name. */ 930 if (!host) 931 usage(); 932 933 host_arg = xstrdup(host); 934 935 #ifdef WITH_OPENSSL 936 OpenSSL_add_all_algorithms(); 937 ERR_load_crypto_strings(); 938 #endif 939 940 /* Initialize the command to execute on remote host. */ 941 buffer_init(&command); 942 943 /* 944 * Save the command to execute on the remote host in a buffer. There 945 * is no limit on the length of the command, except by the maximum 946 * packet size. Also sets the tty flag if there is no command. 947 */ 948 if (!ac) { 949 /* No command specified - execute shell on a tty. */ 950 if (subsystem_flag) { 951 fprintf(stderr, 952 "You must specify a subsystem to invoke.\n"); 953 usage(); 954 } 955 } else { 956 /* A command has been specified. Store it into the buffer. */ 957 for (i = 0; i < ac; i++) { 958 if (i) 959 buffer_append(&command, " ", 1); 960 buffer_append(&command, av[i], strlen(av[i])); 961 } 962 } 963 964 /* Cannot fork to background if no command. */ 965 if (fork_after_authentication_flag && buffer_len(&command) == 0 && 966 !no_shell_flag) 967 fatal("Cannot fork into background without a command " 968 "to execute."); 969 970 /* 971 * Initialize "log" output. Since we are the client all output 972 * goes to stderr unless otherwise specified by -y or -E. 973 */ 974 if (use_syslog && logfile != NULL) 975 fatal("Can't specify both -y and -E"); 976 if (logfile != NULL) 977 log_redirect_stderr_to(logfile); 978 log_init(argv0, 979 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, 980 SYSLOG_FACILITY_USER, !use_syslog); 981 982 if (debug_flag) 983 logit("%s, %s", SSH_VERSION, 984 #ifdef WITH_OPENSSL 985 SSLeay_version(SSLEAY_VERSION) 986 #else 987 "without OpenSSL" 988 #endif 989 ); 990 991 /* Parse the configuration files */ 992 process_config_files(host_arg, pw, 0); 993 994 /* Hostname canonicalisation needs a few options filled. */ 995 fill_default_options_for_canonicalization(&options); 996 997 /* If the user has replaced the hostname then take it into use now */ 998 if (options.hostname != NULL) { 999 /* NB. Please keep in sync with readconf.c:match_cfg_line() */ 1000 cp = percent_expand(options.hostname, 1001 "h", host, (char *)NULL); 1002 free(host); 1003 host = cp; 1004 free(options.hostname); 1005 options.hostname = xstrdup(host); 1006 } 1007 1008 /* If canonicalization requested then try to apply it */ 1009 lowercase(host); 1010 if (options.canonicalize_hostname != SSH_CANONICALISE_NO) 1011 addrs = resolve_canonicalize(&host, options.port); 1012 1013 /* 1014 * If CanonicalizePermittedCNAMEs have been specified but 1015 * other canonicalization did not happen (by not being requested 1016 * or by failing with fallback) then the hostname may still be changed 1017 * as a result of CNAME following. 1018 * 1019 * Try to resolve the bare hostname name using the system resolver's 1020 * usual search rules and then apply the CNAME follow rules. 1021 * 1022 * Skip the lookup if a ProxyCommand is being used unless the user 1023 * has specifically requested canonicalisation for this case via 1024 * CanonicalizeHostname=always 1025 */ 1026 direct = option_clear_or_none(options.proxy_command) && 1027 options.jump_host == NULL; 1028 if (addrs == NULL && options.num_permitted_cnames != 0 && (direct || 1029 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { 1030 if ((addrs = resolve_host(host, options.port, 1031 option_clear_or_none(options.proxy_command), 1032 cname, sizeof(cname))) == NULL) { 1033 /* Don't fatal proxied host names not in the DNS */ 1034 if (option_clear_or_none(options.proxy_command)) 1035 cleanup_exit(255); /* logged in resolve_host */ 1036 } else 1037 check_follow_cname(direct, &host, cname); 1038 } 1039 1040 /* 1041 * If canonicalisation is enabled then re-parse the configuration 1042 * files as new stanzas may match. 1043 */ 1044 if (options.canonicalize_hostname != 0) { 1045 debug("Re-reading configuration after hostname " 1046 "canonicalisation"); 1047 free(options.hostname); 1048 options.hostname = xstrdup(host); 1049 process_config_files(host_arg, pw, 1); 1050 /* 1051 * Address resolution happens early with canonicalisation 1052 * enabled and the port number may have changed since, so 1053 * reset it in address list 1054 */ 1055 if (addrs != NULL && options.port > 0) 1056 set_addrinfo_port(addrs, options.port); 1057 } 1058 1059 /* Fill configuration defaults. */ 1060 fill_default_options(&options); 1061 1062 /* 1063 * If ProxyJump option specified, then construct a ProxyCommand now. 1064 */ 1065 if (options.jump_host != NULL) { 1066 char port_s[8]; 1067 1068 /* Consistency check */ 1069 if (options.proxy_command != NULL) 1070 fatal("inconsistent options: ProxyCommand+ProxyJump"); 1071 /* Never use FD passing for ProxyJump */ 1072 options.proxy_use_fdpass = 0; 1073 snprintf(port_s, sizeof(port_s), "%d", options.jump_port); 1074 xasprintf(&options.proxy_command, 1075 "ssh%s%s%s%s%s%s%s%s%s%.*s -W %%h:%%p %s", 1076 /* Optional "-l user" argument if jump_user set */ 1077 options.jump_user == NULL ? "" : " -l ", 1078 options.jump_user == NULL ? "" : options.jump_user, 1079 /* Optional "-p port" argument if jump_port set */ 1080 options.jump_port <= 0 ? "" : " -p ", 1081 options.jump_port <= 0 ? "" : port_s, 1082 /* Optional additional jump hosts ",..." */ 1083 options.jump_extra == NULL ? "" : " -J ", 1084 options.jump_extra == NULL ? "" : options.jump_extra, 1085 /* Optional "-F" argumment if -F specified */ 1086 config == NULL ? "" : " -F ", 1087 config == NULL ? "" : config, 1088 /* Optional "-v" arguments if -v set */ 1089 debug_flag ? " -" : "", 1090 debug_flag, "vvv", 1091 /* Mandatory hostname */ 1092 options.jump_host); 1093 debug("Setting implicit ProxyCommand from ProxyJump: %s", 1094 options.proxy_command); 1095 } 1096 1097 if (options.port == 0) 1098 options.port = default_ssh_port(); 1099 channel_set_af(options.address_family); 1100 1101 /* Tidy and check options */ 1102 if (options.host_key_alias != NULL) 1103 lowercase(options.host_key_alias); 1104 if (options.proxy_command != NULL && 1105 strcmp(options.proxy_command, "-") == 0 && 1106 options.proxy_use_fdpass) 1107 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); 1108 if (options.control_persist && 1109 options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 1110 debug("UpdateHostKeys=ask is incompatible with ControlPersist; " 1111 "disabling"); 1112 options.update_hostkeys = 0; 1113 } 1114 if (options.connection_attempts <= 0) 1115 fatal("Invalid number of ConnectionAttempts"); 1116 1117 if (original_effective_uid != 0) 1118 options.use_privileged_port = 0; 1119 1120 /* reinit */ 1121 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog); 1122 1123 if (options.request_tty == REQUEST_TTY_YES || 1124 options.request_tty == REQUEST_TTY_FORCE) 1125 tty_flag = 1; 1126 1127 /* Allocate a tty by default if no command specified. */ 1128 if (buffer_len(&command) == 0) 1129 tty_flag = options.request_tty != REQUEST_TTY_NO; 1130 1131 /* Force no tty */ 1132 if (options.request_tty == REQUEST_TTY_NO || 1133 (muxclient_command && muxclient_command != SSHMUX_COMMAND_PROXY)) 1134 tty_flag = 0; 1135 /* Do not allocate a tty if stdin is not a tty. */ 1136 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 1137 options.request_tty != REQUEST_TTY_FORCE) { 1138 if (tty_flag) 1139 logit("Pseudo-terminal will not be allocated because " 1140 "stdin is not a terminal."); 1141 tty_flag = 0; 1142 } 1143 1144 if (options.user == NULL) 1145 options.user = xstrdup(pw->pw_name); 1146 1147 if (gethostname(thishost, sizeof(thishost)) == -1) 1148 fatal("gethostname: %s", strerror(errno)); 1149 strlcpy(shorthost, thishost, sizeof(shorthost)); 1150 shorthost[strcspn(thishost, ".")] = '\0'; 1151 snprintf(portstr, sizeof(portstr), "%d", options.port); 1152 snprintf(uidstr, sizeof(uidstr), "%d", pw->pw_uid); 1153 1154 if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL || 1155 ssh_digest_update(md, thishost, strlen(thishost)) < 0 || 1156 ssh_digest_update(md, host, strlen(host)) < 0 || 1157 ssh_digest_update(md, portstr, strlen(portstr)) < 0 || 1158 ssh_digest_update(md, options.user, strlen(options.user)) < 0 || 1159 ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0) 1160 fatal("%s: mux digest failed", __func__); 1161 ssh_digest_free(md); 1162 conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1)); 1163 1164 if (options.local_command != NULL) { 1165 debug3("expanding LocalCommand: %s", options.local_command); 1166 cp = options.local_command; 1167 options.local_command = percent_expand(cp, 1168 "C", conn_hash_hex, 1169 "L", shorthost, 1170 "d", pw->pw_dir, 1171 "h", host, 1172 "l", thishost, 1173 "n", host_arg, 1174 "p", portstr, 1175 "r", options.user, 1176 "u", pw->pw_name, 1177 (char *)NULL); 1178 debug3("expanded LocalCommand: %s", options.local_command); 1179 free(cp); 1180 } 1181 1182 if (options.control_path != NULL) { 1183 cp = tilde_expand_filename(options.control_path, 1184 original_real_uid); 1185 free(options.control_path); 1186 options.control_path = percent_expand(cp, 1187 "C", conn_hash_hex, 1188 "L", shorthost, 1189 "h", host, 1190 "l", thishost, 1191 "n", host_arg, 1192 "p", portstr, 1193 "r", options.user, 1194 "u", pw->pw_name, 1195 "i", uidstr, 1196 (char *)NULL); 1197 free(cp); 1198 } 1199 free(conn_hash_hex); 1200 1201 if (config_test) { 1202 dump_client_config(&options, host); 1203 exit(0); 1204 } 1205 1206 if (muxclient_command != 0 && options.control_path == NULL) 1207 fatal("No ControlPath specified for \"-O\" command"); 1208 if (options.control_path != NULL) { 1209 int sock; 1210 if ((sock = muxclient(options.control_path)) >= 0) { 1211 packet_set_connection(sock, sock); 1212 ssh = active_state; /* XXX */ 1213 enable_compat20(); /* XXX */ 1214 packet_set_mux(); 1215 goto skip_connect; 1216 } 1217 } 1218 1219 /* 1220 * If hostname canonicalisation was not enabled, then we may not 1221 * have yet resolved the hostname. Do so now. 1222 */ 1223 if (addrs == NULL && options.proxy_command == NULL) { 1224 debug2("resolving \"%s\" port %d", host, options.port); 1225 if ((addrs = resolve_host(host, options.port, 1, 1226 cname, sizeof(cname))) == NULL) 1227 cleanup_exit(255); /* resolve_host logs the error */ 1228 } 1229 1230 timeout_ms = options.connection_timeout * 1000; 1231 1232 /* Open a connection to the remote host. */ 1233 if (ssh_connect(host, addrs, &hostaddr, options.port, 1234 options.address_family, options.connection_attempts, 1235 &timeout_ms, options.tcp_keep_alive, 1236 options.use_privileged_port) != 0) 1237 exit(255); 1238 1239 if (addrs != NULL) 1240 freeaddrinfo(addrs); 1241 1242 packet_set_timeout(options.server_alive_interval, 1243 options.server_alive_count_max); 1244 1245 ssh = active_state; /* XXX */ 1246 1247 if (timeout_ms > 0) 1248 debug3("timeout: %d ms remain after connect", timeout_ms); 1249 1250 /* 1251 * If we successfully made the connection, load the host private key 1252 * in case we will need it later for combined rsa-rhosts 1253 * authentication. This must be done before releasing extra 1254 * privileges, because the file is only readable by root. 1255 * If we cannot access the private keys, load the public keys 1256 * instead and try to execute the ssh-keysign helper instead. 1257 */ 1258 sensitive_data.nkeys = 0; 1259 sensitive_data.keys = NULL; 1260 sensitive_data.external_keysign = 0; 1261 if (options.rhosts_rsa_authentication || 1262 options.hostbased_authentication) { 1263 sensitive_data.nkeys = 9; 1264 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 1265 sizeof(Key)); 1266 1267 PRIV_START; 1268 #if WITH_SSH1 1269 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, 1270 _PATH_HOST_KEY_FILE, "", NULL, NULL); 1271 #endif 1272 sensitive_data.keys[1] = key_load_private_cert(KEY_ECDSA, 1273 _PATH_HOST_ECDSA_KEY_FILE, "", NULL); 1274 sensitive_data.keys[2] = key_load_private_cert(KEY_ED25519, 1275 _PATH_HOST_ED25519_KEY_FILE, "", NULL); 1276 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA, 1277 _PATH_HOST_RSA_KEY_FILE, "", NULL); 1278 sensitive_data.keys[4] = key_load_private_cert(KEY_DSA, 1279 _PATH_HOST_DSA_KEY_FILE, "", NULL); 1280 sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA, 1281 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL); 1282 sensitive_data.keys[6] = key_load_private_type(KEY_ED25519, 1283 _PATH_HOST_ED25519_KEY_FILE, "", NULL, NULL); 1284 sensitive_data.keys[7] = key_load_private_type(KEY_RSA, 1285 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); 1286 sensitive_data.keys[8] = key_load_private_type(KEY_DSA, 1287 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); 1288 PRIV_END; 1289 1290 if (options.hostbased_authentication == 1 && 1291 sensitive_data.keys[0] == NULL && 1292 sensitive_data.keys[5] == NULL && 1293 sensitive_data.keys[6] == NULL && 1294 sensitive_data.keys[7] == NULL && 1295 sensitive_data.keys[8] == NULL) { 1296 sensitive_data.keys[1] = key_load_cert( 1297 _PATH_HOST_ECDSA_KEY_FILE); 1298 sensitive_data.keys[2] = key_load_cert( 1299 _PATH_HOST_ED25519_KEY_FILE); 1300 sensitive_data.keys[3] = key_load_cert( 1301 _PATH_HOST_RSA_KEY_FILE); 1302 sensitive_data.keys[4] = key_load_cert( 1303 _PATH_HOST_DSA_KEY_FILE); 1304 sensitive_data.keys[5] = key_load_public( 1305 _PATH_HOST_ECDSA_KEY_FILE, NULL); 1306 sensitive_data.keys[6] = key_load_public( 1307 _PATH_HOST_ED25519_KEY_FILE, NULL); 1308 sensitive_data.keys[7] = key_load_public( 1309 _PATH_HOST_RSA_KEY_FILE, NULL); 1310 sensitive_data.keys[8] = key_load_public( 1311 _PATH_HOST_DSA_KEY_FILE, NULL); 1312 sensitive_data.external_keysign = 1; 1313 } 1314 } 1315 /* 1316 * Get rid of any extra privileges that we may have. We will no 1317 * longer need them. Also, extra privileges could make it very hard 1318 * to read identity files and other non-world-readable files from the 1319 * user's home directory if it happens to be on a NFS volume where 1320 * root is mapped to nobody. 1321 */ 1322 if (original_effective_uid == 0) { 1323 PRIV_START; 1324 permanently_set_uid(pw); 1325 } 1326 1327 /* 1328 * Now that we are back to our own permissions, create ~/.ssh 1329 * directory if it doesn't already exist. 1330 */ 1331 if (config == NULL) { 1332 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 1333 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 1334 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) 1335 if (mkdir(buf, 0700) < 0) 1336 error("Could not create directory '%.200s'.", 1337 buf); 1338 } 1339 1340 /* load options.identity_files */ 1341 load_public_identity_files(); 1342 1343 /* optionally set the SSH_AUTHSOCKET_ENV_NAME varibale */ 1344 if (options.identity_agent && 1345 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) { 1346 if (strcmp(options.identity_agent, "none") == 0) { 1347 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1348 } else { 1349 p = tilde_expand_filename(options.identity_agent, 1350 original_real_uid); 1351 cp = percent_expand(p, "d", pw->pw_dir, 1352 "u", pw->pw_name, "l", thishost, "h", host, 1353 "r", options.user, (char *)NULL); 1354 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1); 1355 free(cp); 1356 free(p); 1357 } 1358 } 1359 1360 /* Expand ~ in known host file names. */ 1361 tilde_expand_paths(options.system_hostfiles, 1362 options.num_system_hostfiles); 1363 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 1364 1365 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 1366 signal(SIGCHLD, main_sigchld_handler); 1367 1368 /* Log into the remote system. Never returns if the login fails. */ 1369 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, 1370 options.port, pw, timeout_ms); 1371 1372 if (packet_connection_is_on_socket()) { 1373 verbose("Authenticated to %s ([%s]:%d).", host, 1374 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); 1375 } else { 1376 verbose("Authenticated to %s (via proxy).", host); 1377 } 1378 1379 /* We no longer need the private host keys. Clear them now. */ 1380 if (sensitive_data.nkeys != 0) { 1381 for (i = 0; i < sensitive_data.nkeys; i++) { 1382 if (sensitive_data.keys[i] != NULL) { 1383 /* Destroys contents safely */ 1384 debug3("clear hostkey %d", i); 1385 key_free(sensitive_data.keys[i]); 1386 sensitive_data.keys[i] = NULL; 1387 } 1388 } 1389 free(sensitive_data.keys); 1390 } 1391 for (i = 0; i < options.num_identity_files; i++) { 1392 free(options.identity_files[i]); 1393 options.identity_files[i] = NULL; 1394 if (options.identity_keys[i]) { 1395 key_free(options.identity_keys[i]); 1396 options.identity_keys[i] = NULL; 1397 } 1398 } 1399 for (i = 0; i < options.num_certificate_files; i++) { 1400 free(options.certificate_files[i]); 1401 options.certificate_files[i] = NULL; 1402 } 1403 1404 skip_connect: 1405 exit_status = compat20 ? ssh_session2() : ssh_session(); 1406 packet_close(); 1407 1408 if (options.control_path != NULL && muxserver_sock != -1) 1409 unlink(options.control_path); 1410 1411 /* Kill ProxyCommand if it is running. */ 1412 ssh_kill_proxy_command(); 1413 1414 return exit_status; 1415 } 1416 1417 static void 1418 control_persist_detach(void) 1419 { 1420 pid_t pid; 1421 int devnull, keep_stderr; 1422 1423 debug("%s: backgrounding master process", __func__); 1424 1425 /* 1426 * master (current process) into the background, and make the 1427 * foreground process a client of the backgrounded master. 1428 */ 1429 switch ((pid = fork())) { 1430 case -1: 1431 fatal("%s: fork: %s", __func__, strerror(errno)); 1432 case 0: 1433 /* Child: master process continues mainloop */ 1434 break; 1435 default: 1436 /* Parent: set up mux slave to connect to backgrounded master */ 1437 debug2("%s: background process is %ld", __func__, (long)pid); 1438 stdin_null_flag = ostdin_null_flag; 1439 options.request_tty = orequest_tty; 1440 tty_flag = otty_flag; 1441 close(muxserver_sock); 1442 muxserver_sock = -1; 1443 options.control_master = SSHCTL_MASTER_NO; 1444 muxclient(options.control_path); 1445 /* muxclient() doesn't return on success. */ 1446 fatal("Failed to connect to new control master"); 1447 } 1448 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1449 error("%s: open(\"/dev/null\"): %s", __func__, 1450 strerror(errno)); 1451 } else { 1452 keep_stderr = log_is_on_stderr() && debug_flag; 1453 if (dup2(devnull, STDIN_FILENO) == -1 || 1454 dup2(devnull, STDOUT_FILENO) == -1 || 1455 (!keep_stderr && dup2(devnull, STDERR_FILENO) == -1)) 1456 error("%s: dup2: %s", __func__, strerror(errno)); 1457 if (devnull > STDERR_FILENO) 1458 close(devnull); 1459 } 1460 daemon(1, 1); 1461 setproctitle("%s [mux]", options.control_path); 1462 } 1463 1464 /* Do fork() after authentication. Used by "ssh -f" */ 1465 static void 1466 fork_postauth(void) 1467 { 1468 if (need_controlpersist_detach) 1469 control_persist_detach(); 1470 debug("forking to background"); 1471 fork_after_authentication_flag = 0; 1472 if (daemon(1, 1) < 0) 1473 fatal("daemon() failed: %.200s", strerror(errno)); 1474 } 1475 1476 /* Callback for remote forward global requests */ 1477 static void 1478 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) 1479 { 1480 struct Forward *rfwd = (struct Forward *)ctxt; 1481 1482 /* XXX verbose() on failure? */ 1483 debug("remote forward %s for: listen %s%s%d, connect %s:%d", 1484 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1485 rfwd->listen_path ? rfwd->listen_path : 1486 rfwd->listen_host ? rfwd->listen_host : "", 1487 (rfwd->listen_path || rfwd->listen_host) ? ":" : "", 1488 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path : 1489 rfwd->connect_host, rfwd->connect_port); 1490 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) { 1491 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1492 rfwd->allocated_port = packet_get_int(); 1493 logit("Allocated port %u for remote forward to %s:%d", 1494 rfwd->allocated_port, 1495 rfwd->connect_host, rfwd->connect_port); 1496 channel_update_permitted_opens(rfwd->handle, 1497 rfwd->allocated_port); 1498 } else { 1499 channel_update_permitted_opens(rfwd->handle, -1); 1500 } 1501 } 1502 1503 if (type == SSH2_MSG_REQUEST_FAILURE) { 1504 if (options.exit_on_forward_failure) { 1505 if (rfwd->listen_path != NULL) 1506 fatal("Error: remote port forwarding failed " 1507 "for listen path %s", rfwd->listen_path); 1508 else 1509 fatal("Error: remote port forwarding failed " 1510 "for listen port %d", rfwd->listen_port); 1511 } else { 1512 if (rfwd->listen_path != NULL) 1513 logit("Warning: remote port forwarding failed " 1514 "for listen path %s", rfwd->listen_path); 1515 else 1516 logit("Warning: remote port forwarding failed " 1517 "for listen port %d", rfwd->listen_port); 1518 } 1519 } 1520 if (++remote_forward_confirms_received == options.num_remote_forwards) { 1521 debug("All remote forwarding requests processed"); 1522 if (fork_after_authentication_flag) 1523 fork_postauth(); 1524 } 1525 } 1526 1527 static void 1528 client_cleanup_stdio_fwd(int id, void *arg) 1529 { 1530 debug("stdio forwarding: done"); 1531 cleanup_exit(0); 1532 } 1533 1534 static void 1535 ssh_stdio_confirm(int id, int success, void *arg) 1536 { 1537 if (!success) 1538 fatal("stdio forwarding failed"); 1539 } 1540 1541 static void 1542 ssh_init_stdio_forwarding(void) 1543 { 1544 Channel *c; 1545 int in, out; 1546 1547 if (options.stdio_forward_host == NULL) 1548 return; 1549 if (!compat20) 1550 fatal("stdio forwarding require Protocol 2"); 1551 1552 debug3("%s: %s:%d", __func__, options.stdio_forward_host, 1553 options.stdio_forward_port); 1554 1555 if ((in = dup(STDIN_FILENO)) < 0 || 1556 (out = dup(STDOUT_FILENO)) < 0) 1557 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1558 if ((c = channel_connect_stdio_fwd(options.stdio_forward_host, 1559 options.stdio_forward_port, in, out)) == NULL) 1560 fatal("%s: channel_connect_stdio_fwd failed", __func__); 1561 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0); 1562 channel_register_open_confirm(c->self, ssh_stdio_confirm, NULL); 1563 } 1564 1565 static void 1566 ssh_init_forwarding(void) 1567 { 1568 int success = 0; 1569 int i; 1570 1571 /* Initiate local TCP/IP port forwardings. */ 1572 for (i = 0; i < options.num_local_forwards; i++) { 1573 debug("Local connections to %.200s:%d forwarded to remote " 1574 "address %.200s:%d", 1575 (options.local_forwards[i].listen_path != NULL) ? 1576 options.local_forwards[i].listen_path : 1577 (options.local_forwards[i].listen_host == NULL) ? 1578 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") : 1579 options.local_forwards[i].listen_host, 1580 options.local_forwards[i].listen_port, 1581 (options.local_forwards[i].connect_path != NULL) ? 1582 options.local_forwards[i].connect_path : 1583 options.local_forwards[i].connect_host, 1584 options.local_forwards[i].connect_port); 1585 success += channel_setup_local_fwd_listener( 1586 &options.local_forwards[i], &options.fwd_opts); 1587 } 1588 if (i > 0 && success != i && options.exit_on_forward_failure) 1589 fatal("Could not request local forwarding."); 1590 if (i > 0 && success == 0) 1591 error("Could not request local forwarding."); 1592 1593 /* Initiate remote TCP/IP port forwardings. */ 1594 for (i = 0; i < options.num_remote_forwards; i++) { 1595 debug("Remote connections from %.200s:%d forwarded to " 1596 "local address %.200s:%d", 1597 (options.remote_forwards[i].listen_path != NULL) ? 1598 options.remote_forwards[i].listen_path : 1599 (options.remote_forwards[i].listen_host == NULL) ? 1600 "LOCALHOST" : options.remote_forwards[i].listen_host, 1601 options.remote_forwards[i].listen_port, 1602 (options.remote_forwards[i].connect_path != NULL) ? 1603 options.remote_forwards[i].connect_path : 1604 options.remote_forwards[i].connect_host, 1605 options.remote_forwards[i].connect_port); 1606 options.remote_forwards[i].handle = 1607 channel_request_remote_forwarding( 1608 &options.remote_forwards[i]); 1609 if (options.remote_forwards[i].handle < 0) { 1610 if (options.exit_on_forward_failure) 1611 fatal("Could not request remote forwarding."); 1612 else 1613 logit("Warning: Could not request remote " 1614 "forwarding."); 1615 } else { 1616 client_register_global_confirm(ssh_confirm_remote_forward, 1617 &options.remote_forwards[i]); 1618 } 1619 } 1620 1621 /* Initiate tunnel forwarding. */ 1622 if (options.tun_open != SSH_TUNMODE_NO) { 1623 if (client_request_tun_fwd(options.tun_open, 1624 options.tun_local, options.tun_remote) == -1) { 1625 if (options.exit_on_forward_failure) 1626 fatal("Could not request tunnel forwarding."); 1627 else 1628 error("Could not request tunnel forwarding."); 1629 } 1630 } 1631 } 1632 1633 static void 1634 check_agent_present(void) 1635 { 1636 int r; 1637 1638 if (options.forward_agent) { 1639 /* Clear agent forwarding if we don't have an agent. */ 1640 if ((r = ssh_get_authentication_socket(NULL)) != 0) { 1641 options.forward_agent = 0; 1642 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1643 debug("ssh_get_authentication_socket: %s", 1644 ssh_err(r)); 1645 } 1646 } 1647 } 1648 1649 static int 1650 ssh_session(void) 1651 { 1652 int type; 1653 int interactive = 0; 1654 int have_tty = 0; 1655 struct winsize ws; 1656 char *cp; 1657 const char *display; 1658 char *proto = NULL, *data = NULL; 1659 1660 /* Enable compression if requested. */ 1661 if (options.compression) { 1662 debug("Requesting compression at level %d.", 1663 options.compression_level); 1664 1665 if (options.compression_level < 1 || 1666 options.compression_level > 9) 1667 fatal("Compression level must be from 1 (fast) to " 1668 "9 (slow, best)."); 1669 1670 /* Send the request. */ 1671 packet_start(SSH_CMSG_REQUEST_COMPRESSION); 1672 packet_put_int(options.compression_level); 1673 packet_send(); 1674 packet_write_wait(); 1675 type = packet_read(); 1676 if (type == SSH_SMSG_SUCCESS) 1677 packet_start_compression(options.compression_level); 1678 else if (type == SSH_SMSG_FAILURE) 1679 logit("Warning: Remote host refused compression."); 1680 else 1681 packet_disconnect("Protocol error waiting for " 1682 "compression response."); 1683 } 1684 /* Allocate a pseudo tty if appropriate. */ 1685 if (tty_flag) { 1686 debug("Requesting pty."); 1687 1688 /* Start the packet. */ 1689 packet_start(SSH_CMSG_REQUEST_PTY); 1690 1691 /* Store TERM in the packet. There is no limit on the 1692 length of the string. */ 1693 cp = getenv("TERM"); 1694 if (!cp) 1695 cp = ""; 1696 packet_put_cstring(cp); 1697 1698 /* Store window size in the packet. */ 1699 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 1700 memset(&ws, 0, sizeof(ws)); 1701 packet_put_int((u_int)ws.ws_row); 1702 packet_put_int((u_int)ws.ws_col); 1703 packet_put_int((u_int)ws.ws_xpixel); 1704 packet_put_int((u_int)ws.ws_ypixel); 1705 1706 /* Store tty modes in the packet. */ 1707 tty_make_modes(fileno(stdin), NULL); 1708 1709 /* Send the packet, and wait for it to leave. */ 1710 packet_send(); 1711 packet_write_wait(); 1712 1713 /* Read response from the server. */ 1714 type = packet_read(); 1715 if (type == SSH_SMSG_SUCCESS) { 1716 interactive = 1; 1717 have_tty = 1; 1718 } else if (type == SSH_SMSG_FAILURE) 1719 logit("Warning: Remote host failed or refused to " 1720 "allocate a pseudo tty."); 1721 else 1722 packet_disconnect("Protocol error waiting for pty " 1723 "request response."); 1724 } 1725 /* Request X11 forwarding if enabled and DISPLAY is set. */ 1726 display = getenv("DISPLAY"); 1727 if (display == NULL && options.forward_x11) 1728 debug("X11 forwarding requested but DISPLAY not set"); 1729 if (options.forward_x11 && client_x11_get_proto(display, 1730 options.xauth_location, options.forward_x11_trusted, 1731 options.forward_x11_timeout, &proto, &data) == 0) { 1732 /* Request forwarding with authentication spoofing. */ 1733 debug("Requesting X11 forwarding with authentication " 1734 "spoofing."); 1735 x11_request_forwarding_with_spoofing(0, display, proto, 1736 data, 0); 1737 /* Read response from the server. */ 1738 type = packet_read(); 1739 if (type == SSH_SMSG_SUCCESS) { 1740 interactive = 1; 1741 } else if (type == SSH_SMSG_FAILURE) { 1742 logit("Warning: Remote host denied X11 forwarding."); 1743 } else { 1744 packet_disconnect("Protocol error waiting for X11 " 1745 "forwarding"); 1746 } 1747 } 1748 /* Tell the packet module whether this is an interactive session. */ 1749 packet_set_interactive(interactive, 1750 options.ip_qos_interactive, options.ip_qos_bulk); 1751 1752 /* Request authentication agent forwarding if appropriate. */ 1753 check_agent_present(); 1754 1755 if (options.forward_agent) { 1756 debug("Requesting authentication agent forwarding."); 1757 auth_request_forwarding(); 1758 1759 /* Read response from the server. */ 1760 type = packet_read(); 1761 packet_check_eom(); 1762 if (type != SSH_SMSG_SUCCESS) 1763 logit("Warning: Remote host denied authentication agent forwarding."); 1764 } 1765 1766 /* Initiate port forwardings. */ 1767 ssh_init_stdio_forwarding(); 1768 ssh_init_forwarding(); 1769 1770 /* Execute a local command */ 1771 if (options.local_command != NULL && 1772 options.permit_local_command) 1773 ssh_local_cmd(options.local_command); 1774 1775 /* 1776 * If requested and we are not interested in replies to remote 1777 * forwarding requests, then let ssh continue in the background. 1778 */ 1779 if (fork_after_authentication_flag) { 1780 if (options.exit_on_forward_failure && 1781 options.num_remote_forwards > 0) { 1782 debug("deferring postauth fork until remote forward " 1783 "confirmation received"); 1784 } else 1785 fork_postauth(); 1786 } 1787 1788 /* 1789 * If a command was specified on the command line, execute the 1790 * command now. Otherwise request the server to start a shell. 1791 */ 1792 if (buffer_len(&command) > 0) { 1793 int len = buffer_len(&command); 1794 if (len > 900) 1795 len = 900; 1796 debug("Sending command: %.*s", len, 1797 (u_char *)buffer_ptr(&command)); 1798 packet_start(SSH_CMSG_EXEC_CMD); 1799 packet_put_string(buffer_ptr(&command), buffer_len(&command)); 1800 packet_send(); 1801 packet_write_wait(); 1802 } else { 1803 debug("Requesting shell."); 1804 packet_start(SSH_CMSG_EXEC_SHELL); 1805 packet_send(); 1806 packet_write_wait(); 1807 } 1808 1809 /* Enter the interactive session. */ 1810 return client_loop(have_tty, tty_flag ? 1811 options.escape_char : SSH_ESCAPECHAR_NONE, 0); 1812 } 1813 1814 /* request pty/x11/agent/tcpfwd/shell for channel */ 1815 static void 1816 ssh_session2_setup(int id, int success, void *arg) 1817 { 1818 extern char **environ; 1819 const char *display; 1820 int interactive = tty_flag; 1821 char *proto = NULL, *data = NULL; 1822 1823 if (!success) 1824 return; /* No need for error message, channels code sens one */ 1825 1826 display = getenv("DISPLAY"); 1827 if (display == NULL && options.forward_x11) 1828 debug("X11 forwarding requested but DISPLAY not set"); 1829 if (options.forward_x11 && client_x11_get_proto(display, 1830 options.xauth_location, options.forward_x11_trusted, 1831 options.forward_x11_timeout, &proto, &data) == 0) { 1832 /* Request forwarding with authentication spoofing. */ 1833 debug("Requesting X11 forwarding with authentication " 1834 "spoofing."); 1835 x11_request_forwarding_with_spoofing(id, display, proto, 1836 data, 1); 1837 client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN); 1838 /* XXX exit_on_forward_failure */ 1839 interactive = 1; 1840 } 1841 1842 check_agent_present(); 1843 if (options.forward_agent) { 1844 debug("Requesting authentication agent forwarding."); 1845 channel_request_start(id, "auth-agent-req@openssh.com", 0); 1846 packet_send(); 1847 } 1848 1849 /* Tell the packet module whether this is an interactive session. */ 1850 packet_set_interactive(interactive, 1851 options.ip_qos_interactive, options.ip_qos_bulk); 1852 1853 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), 1854 NULL, fileno(stdin), &command, environ); 1855 } 1856 1857 /* open new channel for a session */ 1858 static int 1859 ssh_session2_open(void) 1860 { 1861 Channel *c; 1862 int window, packetmax, in, out, err; 1863 1864 if (stdin_null_flag) { 1865 in = open(_PATH_DEVNULL, O_RDONLY); 1866 } else { 1867 in = dup(STDIN_FILENO); 1868 } 1869 out = dup(STDOUT_FILENO); 1870 err = dup(STDERR_FILENO); 1871 1872 if (in < 0 || out < 0 || err < 0) 1873 fatal("dup() in/out/err failed"); 1874 1875 /* enable nonblocking unless tty */ 1876 if (!isatty(in)) 1877 set_nonblock(in); 1878 if (!isatty(out)) 1879 set_nonblock(out); 1880 if (!isatty(err)) 1881 set_nonblock(err); 1882 1883 window = CHAN_SES_WINDOW_DEFAULT; 1884 packetmax = CHAN_SES_PACKET_DEFAULT; 1885 if (tty_flag) { 1886 window >>= 1; 1887 packetmax >>= 1; 1888 } 1889 c = channel_new( 1890 "session", SSH_CHANNEL_OPENING, in, out, err, 1891 window, packetmax, CHAN_EXTENDED_WRITE, 1892 "client-session", /*nonblock*/0); 1893 1894 debug3("ssh_session2_open: channel_new: %d", c->self); 1895 1896 channel_send_open(c->self); 1897 if (!no_shell_flag) 1898 channel_register_open_confirm(c->self, 1899 ssh_session2_setup, NULL); 1900 1901 return c->self; 1902 } 1903 1904 static int 1905 ssh_session2(void) 1906 { 1907 int id = -1; 1908 1909 /* XXX should be pre-session */ 1910 if (!options.control_persist) 1911 ssh_init_stdio_forwarding(); 1912 ssh_init_forwarding(); 1913 1914 /* Start listening for multiplex clients */ 1915 if (!packet_get_mux()) 1916 muxserver_listen(); 1917 1918 /* 1919 * If we are in control persist mode and have a working mux listen 1920 * socket, then prepare to background ourselves and have a foreground 1921 * client attach as a control slave. 1922 * NB. we must save copies of the flags that we override for 1923 * the backgrounding, since we defer attachment of the slave until 1924 * after the connection is fully established (in particular, 1925 * async rfwd replies have been received for ExitOnForwardFailure). 1926 */ 1927 if (options.control_persist && muxserver_sock != -1) { 1928 ostdin_null_flag = stdin_null_flag; 1929 ono_shell_flag = no_shell_flag; 1930 orequest_tty = options.request_tty; 1931 otty_flag = tty_flag; 1932 stdin_null_flag = 1; 1933 no_shell_flag = 1; 1934 tty_flag = 0; 1935 if (!fork_after_authentication_flag) 1936 need_controlpersist_detach = 1; 1937 fork_after_authentication_flag = 1; 1938 } 1939 /* 1940 * ControlPersist mux listen socket setup failed, attempt the 1941 * stdio forward setup that we skipped earlier. 1942 */ 1943 if (options.control_persist && muxserver_sock == -1) 1944 ssh_init_stdio_forwarding(); 1945 1946 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) 1947 id = ssh_session2_open(); 1948 else { 1949 packet_set_interactive( 1950 options.control_master == SSHCTL_MASTER_NO, 1951 options.ip_qos_interactive, options.ip_qos_bulk); 1952 } 1953 1954 /* If we don't expect to open a new session, then disallow it */ 1955 if (options.control_master == SSHCTL_MASTER_NO && 1956 (datafellows & SSH_NEW_OPENSSH)) { 1957 debug("Requesting no-more-sessions@openssh.com"); 1958 packet_start(SSH2_MSG_GLOBAL_REQUEST); 1959 packet_put_cstring("no-more-sessions@openssh.com"); 1960 packet_put_char(0); 1961 packet_send(); 1962 } 1963 1964 /* Execute a local command */ 1965 if (options.local_command != NULL && 1966 options.permit_local_command) 1967 ssh_local_cmd(options.local_command); 1968 1969 /* 1970 * If requested and we are not interested in replies to remote 1971 * forwarding requests, then let ssh continue in the background. 1972 */ 1973 if (fork_after_authentication_flag) { 1974 if (options.exit_on_forward_failure && 1975 options.num_remote_forwards > 0) { 1976 debug("deferring postauth fork until remote forward " 1977 "confirmation received"); 1978 } else 1979 fork_postauth(); 1980 } 1981 1982 return client_loop(tty_flag, tty_flag ? 1983 options.escape_char : SSH_ESCAPECHAR_NONE, id); 1984 } 1985 1986 /* Loads all IdentityFile and CertificateFile keys */ 1987 static void 1988 load_public_identity_files(void) 1989 { 1990 char *filename, *cp, thishost[NI_MAXHOST]; 1991 char *pwdir = NULL, *pwname = NULL; 1992 Key *public; 1993 struct passwd *pw; 1994 int i; 1995 u_int n_ids, n_certs; 1996 char *identity_files[SSH_MAX_IDENTITY_FILES]; 1997 Key *identity_keys[SSH_MAX_IDENTITY_FILES]; 1998 char *certificate_files[SSH_MAX_CERTIFICATE_FILES]; 1999 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES]; 2000 #ifdef ENABLE_PKCS11 2001 Key **keys; 2002 int nkeys; 2003 #endif /* PKCS11 */ 2004 2005 n_ids = n_certs = 0; 2006 memset(identity_files, 0, sizeof(identity_files)); 2007 memset(identity_keys, 0, sizeof(identity_keys)); 2008 memset(certificate_files, 0, sizeof(certificate_files)); 2009 memset(certificates, 0, sizeof(certificates)); 2010 2011 #ifdef ENABLE_PKCS11 2012 if (options.pkcs11_provider != NULL && 2013 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 2014 (pkcs11_init(!options.batch_mode) == 0) && 2015 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 2016 &keys)) > 0) { 2017 for (i = 0; i < nkeys; i++) { 2018 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 2019 key_free(keys[i]); 2020 continue; 2021 } 2022 identity_keys[n_ids] = keys[i]; 2023 identity_files[n_ids] = 2024 xstrdup(options.pkcs11_provider); /* XXX */ 2025 n_ids++; 2026 } 2027 free(keys); 2028 } 2029 #endif /* ENABLE_PKCS11 */ 2030 if ((pw = getpwuid(original_real_uid)) == NULL) 2031 fatal("load_public_identity_files: getpwuid failed"); 2032 pwname = xstrdup(pw->pw_name); 2033 pwdir = xstrdup(pw->pw_dir); 2034 if (gethostname(thishost, sizeof(thishost)) == -1) 2035 fatal("load_public_identity_files: gethostname: %s", 2036 strerror(errno)); 2037 for (i = 0; i < options.num_identity_files; i++) { 2038 if (n_ids >= SSH_MAX_IDENTITY_FILES || 2039 strcasecmp(options.identity_files[i], "none") == 0) { 2040 free(options.identity_files[i]); 2041 options.identity_files[i] = NULL; 2042 continue; 2043 } 2044 cp = tilde_expand_filename(options.identity_files[i], 2045 original_real_uid); 2046 filename = percent_expand(cp, "d", pwdir, 2047 "u", pwname, "l", thishost, "h", host, 2048 "r", options.user, (char *)NULL); 2049 free(cp); 2050 public = key_load_public(filename, NULL); 2051 debug("identity file %s type %d", filename, 2052 public ? public->type : -1); 2053 free(options.identity_files[i]); 2054 identity_files[n_ids] = filename; 2055 identity_keys[n_ids] = public; 2056 2057 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 2058 continue; 2059 2060 /* 2061 * If no certificates have been explicitly listed then try 2062 * to add the default certificate variant too. 2063 */ 2064 if (options.num_certificate_files != 0) 2065 continue; 2066 xasprintf(&cp, "%s-cert", filename); 2067 public = key_load_public(cp, NULL); 2068 debug("identity file %s type %d", cp, 2069 public ? public->type : -1); 2070 if (public == NULL) { 2071 free(cp); 2072 continue; 2073 } 2074 if (!key_is_cert(public)) { 2075 debug("%s: key %s type %s is not a certificate", 2076 __func__, cp, key_type(public)); 2077 key_free(public); 2078 free(cp); 2079 continue; 2080 } 2081 /* NB. leave filename pointing to private key */ 2082 identity_files[n_ids] = xstrdup(filename); 2083 identity_keys[n_ids] = public; 2084 n_ids++; 2085 } 2086 2087 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES) 2088 fatal("%s: too many certificates", __func__); 2089 for (i = 0; i < options.num_certificate_files; i++) { 2090 cp = tilde_expand_filename(options.certificate_files[i], 2091 original_real_uid); 2092 filename = percent_expand(cp, "d", pwdir, 2093 "u", pwname, "l", thishost, "h", host, 2094 "r", options.user, (char *)NULL); 2095 free(cp); 2096 2097 public = key_load_public(filename, NULL); 2098 debug("certificate file %s type %d", filename, 2099 public ? public->type : -1); 2100 free(options.certificate_files[i]); 2101 options.certificate_files[i] = NULL; 2102 if (public == NULL) { 2103 free(filename); 2104 continue; 2105 } 2106 if (!key_is_cert(public)) { 2107 debug("%s: key %s type %s is not a certificate", 2108 __func__, filename, key_type(public)); 2109 key_free(public); 2110 free(filename); 2111 continue; 2112 } 2113 certificate_files[n_certs] = filename; 2114 certificates[n_certs] = public; 2115 ++n_certs; 2116 } 2117 2118 options.num_identity_files = n_ids; 2119 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 2120 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 2121 2122 options.num_certificate_files = n_certs; 2123 memcpy(options.certificate_files, 2124 certificate_files, sizeof(certificate_files)); 2125 memcpy(options.certificates, certificates, sizeof(certificates)); 2126 2127 explicit_bzero(pwname, strlen(pwname)); 2128 free(pwname); 2129 explicit_bzero(pwdir, strlen(pwdir)); 2130 free(pwdir); 2131 } 2132 2133 static void 2134 main_sigchld_handler(int sig) 2135 { 2136 int save_errno = errno; 2137 pid_t pid; 2138 int status; 2139 2140 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 2141 (pid < 0 && errno == EINTR)) 2142 ; 2143 2144 signal(sig, main_sigchld_handler); 2145 errno = save_errno; 2146 } 2147