1 /* $OpenBSD: ssh.c,v 1.428 2015/10/16 18:40:49 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 66 #ifdef WITH_OPENSSL 67 #include <openssl/evp.h> 68 #include <openssl/err.h> 69 #endif 70 71 #include "xmalloc.h" 72 #include "ssh.h" 73 #include "ssh1.h" 74 #include "ssh2.h" 75 #include "canohost.h" 76 #include "compat.h" 77 #include "cipher.h" 78 #include "digest.h" 79 #include "packet.h" 80 #include "buffer.h" 81 #include "channels.h" 82 #include "key.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 "uidswap.h" 98 #include "roaming.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 /* forward stdio to remote host and port */ 141 char *stdio_forward_host = NULL; 142 int stdio_forward_port = 0; 143 144 /* 145 * General data structure for command line options and options configurable 146 * in configuration files. See readconf.h. 147 */ 148 Options options; 149 150 /* optional user configfile */ 151 char *config = NULL; 152 153 /* 154 * Name of the host we are connecting to. This is the name given on the 155 * command line, or the HostName specified for the user-supplied name in a 156 * configuration file. 157 */ 158 char *host; 159 160 /* socket address the host resolves to */ 161 struct sockaddr_storage hostaddr; 162 163 /* Private host keys. */ 164 Sensitive sensitive_data; 165 166 /* Original real UID. */ 167 uid_t original_real_uid; 168 uid_t original_effective_uid; 169 170 /* command to be executed */ 171 Buffer 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 remote_forward_confirms_received = 0; 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 [-1246AaCfGgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n" 190 " [-D [bind_address:]port] [-E log_file] [-e escape_char]\n" 191 " [-F configfile] [-I pkcs11] [-i identity_file] [-L address]\n" 192 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" 193 " [-Q query_option] [-R address] [-S ctl_path] [-W host:port]\n" 194 " [-w local_tun[:remote_tun]] [user@]hostname [command]\n" 195 ); 196 exit(255); 197 } 198 199 static int ssh_session(void); 200 static int ssh_session2(void); 201 static void load_public_identity_files(void); 202 static void main_sigchld_handler(int); 203 204 /* from muxclient.c */ 205 void muxclient(const char *); 206 void muxserver_listen(void); 207 208 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 209 static void 210 tilde_expand_paths(char **paths, u_int num_paths) 211 { 212 u_int i; 213 char *cp; 214 215 for (i = 0; i < num_paths; i++) { 216 cp = tilde_expand_filename(paths[i], original_real_uid); 217 free(paths[i]); 218 paths[i] = cp; 219 } 220 } 221 222 /* 223 * Attempt to resolve a host name / port to a set of addresses and 224 * optionally return any CNAMEs encountered along the way. 225 * Returns NULL on failure. 226 * NB. this function must operate with a options having undefined members. 227 */ 228 static struct addrinfo * 229 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen) 230 { 231 char strport[NI_MAXSERV]; 232 struct addrinfo hints, *res; 233 int gaierr, loglevel = SYSLOG_LEVEL_DEBUG1; 234 235 if (port <= 0) 236 port = default_ssh_port(); 237 238 snprintf(strport, sizeof strport, "%d", port); 239 memset(&hints, 0, sizeof(hints)); 240 hints.ai_family = options.address_family == -1 ? 241 AF_UNSPEC : options.address_family; 242 hints.ai_socktype = SOCK_STREAM; 243 if (cname != NULL) 244 hints.ai_flags = AI_CANONNAME; 245 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 246 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) 247 loglevel = SYSLOG_LEVEL_ERROR; 248 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", 249 __progname, name, ssh_gai_strerror(gaierr)); 250 return NULL; 251 } 252 if (cname != NULL && res->ai_canonname != NULL) { 253 if (strlcpy(cname, res->ai_canonname, clen) >= clen) { 254 error("%s: host \"%s\" cname \"%s\" too long (max %lu)", 255 __func__, name, res->ai_canonname, (u_long)clen); 256 if (clen > 0) 257 *cname = '\0'; 258 } 259 } 260 return res; 261 } 262 263 /* 264 * Attempt to resolve a numeric host address / port to a single address. 265 * Returns a canonical address string. 266 * Returns NULL on failure. 267 * NB. this function must operate with a options having undefined members. 268 */ 269 static struct addrinfo * 270 resolve_addr(const char *name, int port, char *caddr, size_t clen) 271 { 272 char addr[NI_MAXHOST], strport[NI_MAXSERV]; 273 struct addrinfo hints, *res; 274 int gaierr; 275 276 if (port <= 0) 277 port = default_ssh_port(); 278 snprintf(strport, sizeof strport, "%u", port); 279 memset(&hints, 0, sizeof(hints)); 280 hints.ai_family = options.address_family == -1 ? 281 AF_UNSPEC : options.address_family; 282 hints.ai_socktype = SOCK_STREAM; 283 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 284 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 285 debug2("%s: could not resolve name %.100s as address: %s", 286 __func__, name, ssh_gai_strerror(gaierr)); 287 return NULL; 288 } 289 if (res == NULL) { 290 debug("%s: getaddrinfo %.100s returned no addresses", 291 __func__, name); 292 return NULL; 293 } 294 if (res->ai_next != NULL) { 295 debug("%s: getaddrinfo %.100s returned multiple addresses", 296 __func__, name); 297 goto fail; 298 } 299 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen, 300 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) { 301 debug("%s: Could not format address for name %.100s: %s", 302 __func__, name, ssh_gai_strerror(gaierr)); 303 goto fail; 304 } 305 if (strlcpy(caddr, addr, clen) >= clen) { 306 error("%s: host \"%s\" addr \"%s\" too long (max %lu)", 307 __func__, name, addr, (u_long)clen); 308 if (clen > 0) 309 *caddr = '\0'; 310 fail: 311 freeaddrinfo(res); 312 return NULL; 313 } 314 return res; 315 } 316 317 /* 318 * Check whether the cname is a permitted replacement for the hostname 319 * and perform the replacement if it is. 320 * NB. this function must operate with a options having undefined members. 321 */ 322 static int 323 check_follow_cname(char **namep, const char *cname) 324 { 325 int i; 326 struct allowed_cname *rule; 327 328 if (*cname == '\0' || options.num_permitted_cnames == 0 || 329 strcmp(*namep, cname) == 0) 330 return 0; 331 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 332 return 0; 333 /* 334 * Don't attempt to canonicalize names that will be interpreted by 335 * a proxy unless the user specifically requests so. 336 */ 337 if (!option_clear_or_none(options.proxy_command) && 338 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 339 return 0; 340 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname); 341 for (i = 0; i < options.num_permitted_cnames; i++) { 342 rule = options.permitted_cnames + i; 343 if (match_pattern_list(*namep, rule->source_list, 1) != 1 || 344 match_pattern_list(cname, rule->target_list, 1) != 1) 345 continue; 346 verbose("Canonicalized DNS aliased hostname " 347 "\"%s\" => \"%s\"", *namep, cname); 348 free(*namep); 349 *namep = xstrdup(cname); 350 return 1; 351 } 352 return 0; 353 } 354 355 /* 356 * Attempt to resolve the supplied hostname after applying the user's 357 * canonicalization rules. Returns the address list for the host or NULL 358 * if no name was found after canonicalization. 359 * NB. this function must operate with a options having undefined members. 360 */ 361 static struct addrinfo * 362 resolve_canonicalize(char **hostp, int port) 363 { 364 int i, ndots; 365 char *cp, *fullhost, newname[NI_MAXHOST]; 366 struct addrinfo *addrs; 367 368 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 369 return NULL; 370 371 /* 372 * Don't attempt to canonicalize names that will be interpreted by 373 * a proxy unless the user specifically requests so. 374 */ 375 if (!option_clear_or_none(options.proxy_command) && 376 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 377 return NULL; 378 379 /* Try numeric hostnames first */ 380 if ((addrs = resolve_addr(*hostp, port, 381 newname, sizeof(newname))) != NULL) { 382 debug2("%s: hostname %.100s is address", __func__, *hostp); 383 if (strcasecmp(*hostp, newname) != 0) { 384 debug2("%s: canonicalised address \"%s\" => \"%s\"", 385 __func__, *hostp, newname); 386 free(*hostp); 387 *hostp = xstrdup(newname); 388 } 389 return addrs; 390 } 391 392 /* If domain name is anchored, then resolve it now */ 393 if ((*hostp)[strlen(*hostp) - 1] == '.') { 394 debug3("%s: name is fully qualified", __func__); 395 fullhost = xstrdup(*hostp); 396 if ((addrs = resolve_host(fullhost, port, 0, 397 newname, sizeof(newname))) != NULL) 398 goto found; 399 free(fullhost); 400 goto notfound; 401 } 402 403 /* Don't apply canonicalization to sufficiently-qualified hostnames */ 404 ndots = 0; 405 for (cp = *hostp; *cp != '\0'; cp++) { 406 if (*cp == '.') 407 ndots++; 408 } 409 if (ndots > options.canonicalize_max_dots) { 410 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)", 411 __func__, *hostp, options.canonicalize_max_dots); 412 return NULL; 413 } 414 /* Attempt each supplied suffix */ 415 for (i = 0; i < options.num_canonical_domains; i++) { 416 *newname = '\0'; 417 xasprintf(&fullhost, "%s.%s.", *hostp, 418 options.canonical_domains[i]); 419 debug3("%s: attempting \"%s\" => \"%s\"", __func__, 420 *hostp, fullhost); 421 if ((addrs = resolve_host(fullhost, port, 0, 422 newname, sizeof(newname))) == NULL) { 423 free(fullhost); 424 continue; 425 } 426 found: 427 /* Remove trailing '.' */ 428 fullhost[strlen(fullhost) - 1] = '\0'; 429 /* Follow CNAME if requested */ 430 if (!check_follow_cname(&fullhost, newname)) { 431 debug("Canonicalized hostname \"%s\" => \"%s\"", 432 *hostp, fullhost); 433 } 434 free(*hostp); 435 *hostp = fullhost; 436 return addrs; 437 } 438 notfound: 439 if (!options.canonicalize_fallback_local) 440 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); 441 debug2("%s: host %s not found in any suffix", __func__, *hostp); 442 return NULL; 443 } 444 445 /* 446 * Read per-user configuration file. Ignore the system wide config 447 * file if the user specifies a config file on the command line. 448 */ 449 static void 450 process_config_files(const char *host_arg, struct passwd *pw, int post_canon) 451 { 452 char buf[PATH_MAX]; 453 int r; 454 455 if (config != NULL) { 456 if (strcasecmp(config, "none") != 0 && 457 !read_config_file(config, pw, host, host_arg, &options, 458 SSHCONF_USERCONF | (post_canon ? SSHCONF_POSTCANON : 0))) 459 fatal("Can't open user config file %.100s: " 460 "%.100s", config, strerror(errno)); 461 } else { 462 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 463 _PATH_SSH_USER_CONFFILE); 464 if (r > 0 && (size_t)r < sizeof(buf)) 465 (void)read_config_file(buf, pw, host, host_arg, 466 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF | 467 (post_canon ? SSHCONF_POSTCANON : 0)); 468 469 /* Read systemwide configuration file after user config. */ 470 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, 471 host, host_arg, &options, 472 post_canon ? SSHCONF_POSTCANON : 0); 473 } 474 } 475 476 /* Rewrite the port number in an addrinfo list of addresses */ 477 static void 478 set_addrinfo_port(struct addrinfo *addrs, int port) 479 { 480 struct addrinfo *addr; 481 482 for (addr = addrs; addr != NULL; addr = addr->ai_next) { 483 switch (addr->ai_family) { 484 case AF_INET: 485 ((struct sockaddr_in *)addr->ai_addr)-> 486 sin_port = htons(port); 487 break; 488 case AF_INET6: 489 ((struct sockaddr_in6 *)addr->ai_addr)-> 490 sin6_port = htons(port); 491 break; 492 } 493 } 494 } 495 496 /* 497 * Main program for the ssh client. 498 */ 499 int 500 main(int ac, char **av) 501 { 502 int i, r, opt, exit_status, use_syslog, config_test = 0; 503 char *p, *cp, *line, *argv0, buf[PATH_MAX], *host_arg, *logfile; 504 char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 505 char cname[NI_MAXHOST], uidstr[32], *conn_hash_hex; 506 struct stat st; 507 struct passwd *pw; 508 int timeout_ms; 509 extern int optind, optreset; 510 extern char *optarg; 511 struct Forward fwd; 512 struct addrinfo *addrs = NULL; 513 struct ssh_digest_ctx *md; 514 u_char conn_hash[SSH_DIGEST_MAX_LENGTH]; 515 516 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 517 sanitise_stdfd(); 518 519 /* 520 * Discard other fds that are hanging around. These can cause problem 521 * with backgrounded ssh processes started by ControlPersist. 522 */ 523 closefrom(STDERR_FILENO + 1); 524 525 /* 526 * Save the original real uid. It will be needed later (uid-swapping 527 * may clobber the real uid). 528 */ 529 original_real_uid = getuid(); 530 original_effective_uid = geteuid(); 531 532 /* 533 * Use uid-swapping to give up root privileges for the duration of 534 * option processing. We will re-instantiate the rights when we are 535 * ready to create the privileged port, and will permanently drop 536 * them when the port has been created (actually, when the connection 537 * has been made, as we may need to create the port several times). 538 */ 539 PRIV_END; 540 541 /* If we are installed setuid root be careful to not drop core. */ 542 if (original_real_uid != original_effective_uid) { 543 struct rlimit rlim; 544 rlim.rlim_cur = rlim.rlim_max = 0; 545 if (setrlimit(RLIMIT_CORE, &rlim) < 0) 546 fatal("setrlimit failed: %.100s", strerror(errno)); 547 } 548 /* Get user data. */ 549 pw = getpwuid(original_real_uid); 550 if (!pw) { 551 logit("No user exists for uid %lu", (u_long)original_real_uid); 552 exit(255); 553 } 554 /* Take a copy of the returned structure. */ 555 pw = pwcopy(pw); 556 557 /* 558 * Set our umask to something reasonable, as some files are created 559 * with the default umask. This will make them world-readable but 560 * writable only by the owner, which is ok for all files for which we 561 * don't set the modes explicitly. 562 */ 563 umask(022); 564 565 /* 566 * Initialize option structure to indicate that no values have been 567 * set. 568 */ 569 initialize_options(&options); 570 571 /* Parse command-line arguments. */ 572 host = NULL; 573 use_syslog = 0; 574 logfile = NULL; 575 argv0 = av[0]; 576 577 again: 578 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 579 "ACD:E:F:GI:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { 580 switch (opt) { 581 case '1': 582 options.protocol = SSH_PROTO_1; 583 break; 584 case '2': 585 options.protocol = SSH_PROTO_2; 586 break; 587 case '4': 588 options.address_family = AF_INET; 589 break; 590 case '6': 591 options.address_family = AF_INET6; 592 break; 593 case 'n': 594 stdin_null_flag = 1; 595 break; 596 case 'f': 597 fork_after_authentication_flag = 1; 598 stdin_null_flag = 1; 599 break; 600 case 'x': 601 options.forward_x11 = 0; 602 break; 603 case 'X': 604 options.forward_x11 = 1; 605 break; 606 case 'y': 607 use_syslog = 1; 608 break; 609 case 'E': 610 logfile = optarg; 611 break; 612 case 'G': 613 config_test = 1; 614 break; 615 case 'Y': 616 options.forward_x11 = 1; 617 options.forward_x11_trusted = 1; 618 break; 619 case 'g': 620 options.fwd_opts.gateway_ports = 1; 621 break; 622 case 'O': 623 if (stdio_forward_host != NULL) 624 fatal("Cannot specify multiplexing " 625 "command with -W"); 626 else if (muxclient_command != 0) 627 fatal("Multiplexing command already specified"); 628 if (strcmp(optarg, "check") == 0) 629 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 630 else if (strcmp(optarg, "forward") == 0) 631 muxclient_command = SSHMUX_COMMAND_FORWARD; 632 else if (strcmp(optarg, "exit") == 0) 633 muxclient_command = SSHMUX_COMMAND_TERMINATE; 634 else if (strcmp(optarg, "stop") == 0) 635 muxclient_command = SSHMUX_COMMAND_STOP; 636 else if (strcmp(optarg, "cancel") == 0) 637 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 638 else 639 fatal("Invalid multiplex command."); 640 break; 641 case 'P': /* deprecated */ 642 options.use_privileged_port = 0; 643 break; 644 case 'Q': 645 cp = NULL; 646 if (strcmp(optarg, "cipher") == 0) 647 cp = cipher_alg_list('\n', 0); 648 else if (strcmp(optarg, "cipher-auth") == 0) 649 cp = cipher_alg_list('\n', 1); 650 else if (strcmp(optarg, "mac") == 0) 651 cp = mac_alg_list('\n'); 652 else if (strcmp(optarg, "kex") == 0) 653 cp = kex_alg_list('\n'); 654 else if (strcmp(optarg, "key") == 0) 655 cp = key_alg_list(0, 0); 656 else if (strcmp(optarg, "key-cert") == 0) 657 cp = key_alg_list(1, 0); 658 else if (strcmp(optarg, "key-plain") == 0) 659 cp = key_alg_list(0, 1); 660 else if (strcmp(optarg, "protocol-version") == 0) { 661 #ifdef WITH_SSH1 662 cp = xstrdup("1\n2"); 663 #else 664 cp = xstrdup("2"); 665 #endif 666 } 667 if (cp == NULL) 668 fatal("Unsupported query \"%s\"", optarg); 669 printf("%s\n", cp); 670 free(cp); 671 exit(0); 672 break; 673 case 'a': 674 options.forward_agent = 0; 675 break; 676 case 'A': 677 options.forward_agent = 1; 678 break; 679 case 'k': 680 options.gss_deleg_creds = 0; 681 break; 682 case 'K': 683 options.gss_authentication = 1; 684 options.gss_deleg_creds = 1; 685 break; 686 case 'i': 687 if (stat(optarg, &st) < 0) { 688 fprintf(stderr, "Warning: Identity file %s " 689 "not accessible: %s.\n", optarg, 690 strerror(errno)); 691 break; 692 } 693 add_identity_file(&options, NULL, optarg, 1); 694 break; 695 case 'I': 696 #ifdef ENABLE_PKCS11 697 free(options.pkcs11_provider); 698 options.pkcs11_provider = xstrdup(optarg); 699 #else 700 fprintf(stderr, "no support for PKCS#11.\n"); 701 #endif 702 break; 703 case 't': 704 if (options.request_tty == REQUEST_TTY_YES) 705 options.request_tty = REQUEST_TTY_FORCE; 706 else 707 options.request_tty = REQUEST_TTY_YES; 708 break; 709 case 'v': 710 if (debug_flag == 0) { 711 debug_flag = 1; 712 options.log_level = SYSLOG_LEVEL_DEBUG1; 713 } else { 714 if (options.log_level < SYSLOG_LEVEL_DEBUG3) 715 options.log_level++; 716 } 717 break; 718 case 'V': 719 fprintf(stderr, "%s, %s\n", 720 SSH_VERSION, 721 #ifdef WITH_OPENSSL 722 SSLeay_version(SSLEAY_VERSION) 723 #else 724 "without OpenSSL" 725 #endif 726 ); 727 if (opt == 'V') 728 exit(0); 729 break; 730 case 'w': 731 if (options.tun_open == -1) 732 options.tun_open = SSH_TUNMODE_DEFAULT; 733 options.tun_local = a2tun(optarg, &options.tun_remote); 734 if (options.tun_local == SSH_TUNID_ERR) { 735 fprintf(stderr, 736 "Bad tun device '%s'\n", optarg); 737 exit(255); 738 } 739 break; 740 case 'W': 741 if (stdio_forward_host != NULL) 742 fatal("stdio forward already specified"); 743 if (muxclient_command != 0) 744 fatal("Cannot specify stdio forward with -O"); 745 if (parse_forward(&fwd, optarg, 1, 0)) { 746 stdio_forward_host = fwd.listen_host; 747 stdio_forward_port = fwd.listen_port; 748 free(fwd.connect_host); 749 } else { 750 fprintf(stderr, 751 "Bad stdio forwarding specification '%s'\n", 752 optarg); 753 exit(255); 754 } 755 options.request_tty = REQUEST_TTY_NO; 756 no_shell_flag = 1; 757 options.clear_forwardings = 1; 758 options.exit_on_forward_failure = 1; 759 break; 760 case 'q': 761 options.log_level = SYSLOG_LEVEL_QUIET; 762 break; 763 case 'e': 764 if (optarg[0] == '^' && optarg[2] == 0 && 765 (u_char) optarg[1] >= 64 && 766 (u_char) optarg[1] < 128) 767 options.escape_char = (u_char) optarg[1] & 31; 768 else if (strlen(optarg) == 1) 769 options.escape_char = (u_char) optarg[0]; 770 else if (strcmp(optarg, "none") == 0) 771 options.escape_char = SSH_ESCAPECHAR_NONE; 772 else { 773 fprintf(stderr, "Bad escape character '%s'.\n", 774 optarg); 775 exit(255); 776 } 777 break; 778 case 'c': 779 if (ciphers_valid(*optarg == '+' ? 780 optarg + 1 : optarg)) { 781 /* SSH2 only */ 782 free(options.ciphers); 783 options.ciphers = xstrdup(optarg); 784 options.cipher = SSH_CIPHER_INVALID; 785 break; 786 } 787 /* SSH1 only */ 788 options.cipher = cipher_number(optarg); 789 if (options.cipher == -1) { 790 fprintf(stderr, "Unknown cipher type '%s'\n", 791 optarg); 792 exit(255); 793 } 794 if (options.cipher == SSH_CIPHER_3DES) 795 options.ciphers = xstrdup("3des-cbc"); 796 else if (options.cipher == SSH_CIPHER_BLOWFISH) 797 options.ciphers = xstrdup("blowfish-cbc"); 798 else 799 options.ciphers = xstrdup(KEX_CLIENT_ENCRYPT); 800 break; 801 case 'm': 802 if (mac_valid(optarg)) { 803 free(options.macs); 804 options.macs = xstrdup(optarg); 805 } else { 806 fprintf(stderr, "Unknown mac type '%s'\n", 807 optarg); 808 exit(255); 809 } 810 break; 811 case 'M': 812 if (options.control_master == SSHCTL_MASTER_YES) 813 options.control_master = SSHCTL_MASTER_ASK; 814 else 815 options.control_master = SSHCTL_MASTER_YES; 816 break; 817 case 'p': 818 options.port = a2port(optarg); 819 if (options.port <= 0) { 820 fprintf(stderr, "Bad port '%s'\n", optarg); 821 exit(255); 822 } 823 break; 824 case 'l': 825 options.user = optarg; 826 break; 827 828 case 'L': 829 if (parse_forward(&fwd, optarg, 0, 0)) 830 add_local_forward(&options, &fwd); 831 else { 832 fprintf(stderr, 833 "Bad local forwarding specification '%s'\n", 834 optarg); 835 exit(255); 836 } 837 break; 838 839 case 'R': 840 if (parse_forward(&fwd, optarg, 0, 1)) { 841 add_remote_forward(&options, &fwd); 842 } else { 843 fprintf(stderr, 844 "Bad remote forwarding specification " 845 "'%s'\n", optarg); 846 exit(255); 847 } 848 break; 849 850 case 'D': 851 if (parse_forward(&fwd, optarg, 1, 0)) { 852 add_local_forward(&options, &fwd); 853 } else { 854 fprintf(stderr, 855 "Bad dynamic forwarding specification " 856 "'%s'\n", optarg); 857 exit(255); 858 } 859 break; 860 861 case 'C': 862 options.compression = 1; 863 break; 864 case 'N': 865 no_shell_flag = 1; 866 options.request_tty = REQUEST_TTY_NO; 867 break; 868 case 'T': 869 options.request_tty = REQUEST_TTY_NO; 870 break; 871 case 'o': 872 line = xstrdup(optarg); 873 if (process_config_line(&options, pw, 874 host ? host : "", host ? host : "", line, 875 "command-line", 0, NULL, SSHCONF_USERCONF) != 0) 876 exit(255); 877 free(line); 878 break; 879 case 's': 880 subsystem_flag = 1; 881 break; 882 case 'S': 883 if (options.control_path != NULL) 884 free(options.control_path); 885 options.control_path = xstrdup(optarg); 886 break; 887 case 'b': 888 options.bind_address = optarg; 889 break; 890 case 'F': 891 config = optarg; 892 break; 893 default: 894 usage(); 895 } 896 } 897 898 ac -= optind; 899 av += optind; 900 901 if (ac > 0 && !host) { 902 if (strrchr(*av, '@')) { 903 p = xstrdup(*av); 904 cp = strrchr(p, '@'); 905 if (cp == NULL || cp == p) 906 usage(); 907 options.user = p; 908 *cp = '\0'; 909 host = xstrdup(++cp); 910 } else 911 host = xstrdup(*av); 912 if (ac > 1) { 913 optind = optreset = 1; 914 goto again; 915 } 916 ac--, av++; 917 } 918 919 /* Check that we got a host name. */ 920 if (!host) 921 usage(); 922 923 host_arg = xstrdup(host); 924 925 #ifdef WITH_OPENSSL 926 OpenSSL_add_all_algorithms(); 927 ERR_load_crypto_strings(); 928 #endif 929 930 /* Initialize the command to execute on remote host. */ 931 buffer_init(&command); 932 933 /* 934 * Save the command to execute on the remote host in a buffer. There 935 * is no limit on the length of the command, except by the maximum 936 * packet size. Also sets the tty flag if there is no command. 937 */ 938 if (!ac) { 939 /* No command specified - execute shell on a tty. */ 940 if (subsystem_flag) { 941 fprintf(stderr, 942 "You must specify a subsystem to invoke.\n"); 943 usage(); 944 } 945 } else { 946 /* A command has been specified. Store it into the buffer. */ 947 for (i = 0; i < ac; i++) { 948 if (i) 949 buffer_append(&command, " ", 1); 950 buffer_append(&command, av[i], strlen(av[i])); 951 } 952 } 953 954 /* Cannot fork to background if no command. */ 955 if (fork_after_authentication_flag && buffer_len(&command) == 0 && 956 !no_shell_flag) 957 fatal("Cannot fork into background without a command " 958 "to execute."); 959 960 /* 961 * Initialize "log" output. Since we are the client all output 962 * goes to stderr unless otherwise specified by -y or -E. 963 */ 964 if (use_syslog && logfile != NULL) 965 fatal("Can't specify both -y and -E"); 966 if (logfile != NULL) 967 log_redirect_stderr_to(logfile); 968 log_init(argv0, 969 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, 970 SYSLOG_FACILITY_USER, !use_syslog); 971 972 if (debug_flag) 973 logit("%s, %s", SSH_VERSION, 974 #ifdef WITH_OPENSSL 975 SSLeay_version(SSLEAY_VERSION) 976 #else 977 "without OpenSSL" 978 #endif 979 ); 980 981 /* Parse the configuration files */ 982 process_config_files(host_arg, pw, 0); 983 984 /* Hostname canonicalisation needs a few options filled. */ 985 fill_default_options_for_canonicalization(&options); 986 987 /* If the user has replaced the hostname then take it into use now */ 988 if (options.hostname != NULL) { 989 /* NB. Please keep in sync with readconf.c:match_cfg_line() */ 990 cp = percent_expand(options.hostname, 991 "h", host, (char *)NULL); 992 free(host); 993 host = cp; 994 free(options.hostname); 995 options.hostname = xstrdup(host); 996 } 997 998 /* If canonicalization requested then try to apply it */ 999 lowercase(host); 1000 if (options.canonicalize_hostname != SSH_CANONICALISE_NO) 1001 addrs = resolve_canonicalize(&host, options.port); 1002 1003 /* 1004 * If CanonicalizePermittedCNAMEs have been specified but 1005 * other canonicalization did not happen (by not being requested 1006 * or by failing with fallback) then the hostname may still be changed 1007 * as a result of CNAME following. 1008 * 1009 * Try to resolve the bare hostname name using the system resolver's 1010 * usual search rules and then apply the CNAME follow rules. 1011 * 1012 * Skip the lookup if a ProxyCommand is being used unless the user 1013 * has specifically requested canonicalisation for this case via 1014 * CanonicalizeHostname=always 1015 */ 1016 if (addrs == NULL && options.num_permitted_cnames != 0 && 1017 (option_clear_or_none(options.proxy_command) || 1018 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { 1019 if ((addrs = resolve_host(host, options.port, 1020 option_clear_or_none(options.proxy_command), 1021 cname, sizeof(cname))) == NULL) { 1022 /* Don't fatal proxied host names not in the DNS */ 1023 if (option_clear_or_none(options.proxy_command)) 1024 cleanup_exit(255); /* logged in resolve_host */ 1025 } else 1026 check_follow_cname(&host, cname); 1027 } 1028 1029 /* 1030 * If canonicalisation is enabled then re-parse the configuration 1031 * files as new stanzas may match. 1032 */ 1033 if (options.canonicalize_hostname != 0) { 1034 debug("Re-reading configuration after hostname " 1035 "canonicalisation"); 1036 free(options.hostname); 1037 options.hostname = xstrdup(host); 1038 process_config_files(host_arg, pw, 1); 1039 /* 1040 * Address resolution happens early with canonicalisation 1041 * enabled and the port number may have changed since, so 1042 * reset it in address list 1043 */ 1044 if (addrs != NULL && options.port > 0) 1045 set_addrinfo_port(addrs, options.port); 1046 } 1047 1048 /* Fill configuration defaults. */ 1049 fill_default_options(&options); 1050 1051 if (options.port == 0) 1052 options.port = default_ssh_port(); 1053 channel_set_af(options.address_family); 1054 1055 /* Tidy and check options */ 1056 if (options.host_key_alias != NULL) 1057 lowercase(options.host_key_alias); 1058 if (options.proxy_command != NULL && 1059 strcmp(options.proxy_command, "-") == 0 && 1060 options.proxy_use_fdpass) 1061 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); 1062 if (options.control_persist && 1063 options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 1064 debug("UpdateHostKeys=ask is incompatible with ControlPersist; " 1065 "disabling"); 1066 options.update_hostkeys = 0; 1067 } 1068 if (original_effective_uid != 0) 1069 options.use_privileged_port = 0; 1070 1071 /* reinit */ 1072 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog); 1073 1074 if (options.request_tty == REQUEST_TTY_YES || 1075 options.request_tty == REQUEST_TTY_FORCE) 1076 tty_flag = 1; 1077 1078 /* Allocate a tty by default if no command specified. */ 1079 if (buffer_len(&command) == 0) 1080 tty_flag = options.request_tty != REQUEST_TTY_NO; 1081 1082 /* Force no tty */ 1083 if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0) 1084 tty_flag = 0; 1085 /* Do not allocate a tty if stdin is not a tty. */ 1086 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 1087 options.request_tty != REQUEST_TTY_FORCE) { 1088 if (tty_flag) 1089 logit("Pseudo-terminal will not be allocated because " 1090 "stdin is not a terminal."); 1091 tty_flag = 0; 1092 } 1093 1094 if (options.user == NULL) 1095 options.user = xstrdup(pw->pw_name); 1096 1097 if (gethostname(thishost, sizeof(thishost)) == -1) 1098 fatal("gethostname: %s", strerror(errno)); 1099 strlcpy(shorthost, thishost, sizeof(shorthost)); 1100 shorthost[strcspn(thishost, ".")] = '\0'; 1101 snprintf(portstr, sizeof(portstr), "%d", options.port); 1102 snprintf(uidstr, sizeof(uidstr), "%d", pw->pw_uid); 1103 1104 if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL || 1105 ssh_digest_update(md, thishost, strlen(thishost)) < 0 || 1106 ssh_digest_update(md, host, strlen(host)) < 0 || 1107 ssh_digest_update(md, portstr, strlen(portstr)) < 0 || 1108 ssh_digest_update(md, options.user, strlen(options.user)) < 0 || 1109 ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0) 1110 fatal("%s: mux digest failed", __func__); 1111 ssh_digest_free(md); 1112 conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1)); 1113 1114 if (options.local_command != NULL) { 1115 debug3("expanding LocalCommand: %s", options.local_command); 1116 cp = options.local_command; 1117 options.local_command = percent_expand(cp, 1118 "C", conn_hash_hex, 1119 "L", shorthost, 1120 "d", pw->pw_dir, 1121 "h", host, 1122 "l", thishost, 1123 "n", host_arg, 1124 "p", portstr, 1125 "r", options.user, 1126 "u", pw->pw_name, 1127 (char *)NULL); 1128 debug3("expanded LocalCommand: %s", options.local_command); 1129 free(cp); 1130 } 1131 1132 if (options.control_path != NULL) { 1133 cp = tilde_expand_filename(options.control_path, 1134 original_real_uid); 1135 free(options.control_path); 1136 options.control_path = percent_expand(cp, 1137 "C", conn_hash_hex, 1138 "L", shorthost, 1139 "h", host, 1140 "l", thishost, 1141 "n", host_arg, 1142 "p", portstr, 1143 "r", options.user, 1144 "u", pw->pw_name, 1145 "i", uidstr, 1146 (char *)NULL); 1147 free(cp); 1148 } 1149 free(conn_hash_hex); 1150 1151 if (config_test) { 1152 dump_client_config(&options, host); 1153 exit(0); 1154 } 1155 1156 if (muxclient_command != 0 && options.control_path == NULL) 1157 fatal("No ControlPath specified for \"-O\" command"); 1158 if (options.control_path != NULL) 1159 muxclient(options.control_path); 1160 1161 /* 1162 * If hostname canonicalisation was not enabled, then we may not 1163 * have yet resolved the hostname. Do so now. 1164 */ 1165 if (addrs == NULL && options.proxy_command == NULL) { 1166 debug2("resolving \"%s\" port %d", host, options.port); 1167 if ((addrs = resolve_host(host, options.port, 1, 1168 cname, sizeof(cname))) == NULL) 1169 cleanup_exit(255); /* resolve_host logs the error */ 1170 } 1171 1172 timeout_ms = options.connection_timeout * 1000; 1173 1174 /* Open a connection to the remote host. */ 1175 if (ssh_connect(host, addrs, &hostaddr, options.port, 1176 options.address_family, options.connection_attempts, 1177 &timeout_ms, options.tcp_keep_alive, 1178 options.use_privileged_port) != 0) 1179 exit(255); 1180 1181 if (addrs != NULL) 1182 freeaddrinfo(addrs); 1183 1184 packet_set_timeout(options.server_alive_interval, 1185 options.server_alive_count_max); 1186 1187 if (timeout_ms > 0) 1188 debug3("timeout: %d ms remain after connect", timeout_ms); 1189 1190 /* 1191 * If we successfully made the connection, load the host private key 1192 * in case we will need it later for combined rsa-rhosts 1193 * authentication. This must be done before releasing extra 1194 * privileges, because the file is only readable by root. 1195 * If we cannot access the private keys, load the public keys 1196 * instead and try to execute the ssh-keysign helper instead. 1197 */ 1198 sensitive_data.nkeys = 0; 1199 sensitive_data.keys = NULL; 1200 sensitive_data.external_keysign = 0; 1201 if (options.rhosts_rsa_authentication || 1202 options.hostbased_authentication) { 1203 sensitive_data.nkeys = 9; 1204 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 1205 sizeof(Key)); 1206 1207 PRIV_START; 1208 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, 1209 _PATH_HOST_KEY_FILE, "", NULL, NULL); 1210 sensitive_data.keys[1] = key_load_private_cert(KEY_ECDSA, 1211 _PATH_HOST_ECDSA_KEY_FILE, "", NULL); 1212 sensitive_data.keys[2] = key_load_private_cert(KEY_ED25519, 1213 _PATH_HOST_ED25519_KEY_FILE, "", NULL); 1214 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA, 1215 _PATH_HOST_RSA_KEY_FILE, "", NULL); 1216 sensitive_data.keys[4] = key_load_private_cert(KEY_DSA, 1217 _PATH_HOST_DSA_KEY_FILE, "", NULL); 1218 sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA, 1219 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL); 1220 sensitive_data.keys[6] = key_load_private_type(KEY_ED25519, 1221 _PATH_HOST_ED25519_KEY_FILE, "", NULL, NULL); 1222 sensitive_data.keys[7] = key_load_private_type(KEY_RSA, 1223 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); 1224 sensitive_data.keys[8] = key_load_private_type(KEY_DSA, 1225 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); 1226 PRIV_END; 1227 1228 if (options.hostbased_authentication == 1 && 1229 sensitive_data.keys[0] == NULL && 1230 sensitive_data.keys[5] == NULL && 1231 sensitive_data.keys[6] == NULL && 1232 sensitive_data.keys[7] == NULL && 1233 sensitive_data.keys[8] == NULL) { 1234 sensitive_data.keys[1] = key_load_cert( 1235 _PATH_HOST_ECDSA_KEY_FILE); 1236 sensitive_data.keys[2] = key_load_cert( 1237 _PATH_HOST_ED25519_KEY_FILE); 1238 sensitive_data.keys[3] = key_load_cert( 1239 _PATH_HOST_RSA_KEY_FILE); 1240 sensitive_data.keys[4] = key_load_cert( 1241 _PATH_HOST_DSA_KEY_FILE); 1242 sensitive_data.keys[5] = key_load_public( 1243 _PATH_HOST_ECDSA_KEY_FILE, NULL); 1244 sensitive_data.keys[6] = key_load_public( 1245 _PATH_HOST_ED25519_KEY_FILE, NULL); 1246 sensitive_data.keys[7] = key_load_public( 1247 _PATH_HOST_RSA_KEY_FILE, NULL); 1248 sensitive_data.keys[8] = key_load_public( 1249 _PATH_HOST_DSA_KEY_FILE, NULL); 1250 sensitive_data.external_keysign = 1; 1251 } 1252 } 1253 /* 1254 * Get rid of any extra privileges that we may have. We will no 1255 * longer need them. Also, extra privileges could make it very hard 1256 * to read identity files and other non-world-readable files from the 1257 * user's home directory if it happens to be on a NFS volume where 1258 * root is mapped to nobody. 1259 */ 1260 if (original_effective_uid == 0) { 1261 PRIV_START; 1262 permanently_set_uid(pw); 1263 } 1264 1265 /* 1266 * Now that we are back to our own permissions, create ~/.ssh 1267 * directory if it doesn't already exist. 1268 */ 1269 if (config == NULL) { 1270 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 1271 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 1272 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) 1273 if (mkdir(buf, 0700) < 0) 1274 error("Could not create directory '%.200s'.", 1275 buf); 1276 } 1277 1278 /* load options.identity_files */ 1279 load_public_identity_files(); 1280 1281 /* Expand ~ in known host file names. */ 1282 tilde_expand_paths(options.system_hostfiles, 1283 options.num_system_hostfiles); 1284 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 1285 1286 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 1287 signal(SIGCHLD, main_sigchld_handler); 1288 1289 /* Log into the remote system. Never returns if the login fails. */ 1290 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, 1291 options.port, pw, timeout_ms); 1292 1293 if (packet_connection_is_on_socket()) { 1294 verbose("Authenticated to %s ([%s]:%d).", host, 1295 get_remote_ipaddr(), get_remote_port()); 1296 } else { 1297 verbose("Authenticated to %s (via proxy).", host); 1298 } 1299 1300 /* We no longer need the private host keys. Clear them now. */ 1301 if (sensitive_data.nkeys != 0) { 1302 for (i = 0; i < sensitive_data.nkeys; i++) { 1303 if (sensitive_data.keys[i] != NULL) { 1304 /* Destroys contents safely */ 1305 debug3("clear hostkey %d", i); 1306 key_free(sensitive_data.keys[i]); 1307 sensitive_data.keys[i] = NULL; 1308 } 1309 } 1310 free(sensitive_data.keys); 1311 } 1312 for (i = 0; i < options.num_identity_files; i++) { 1313 free(options.identity_files[i]); 1314 options.identity_files[i] = NULL; 1315 if (options.identity_keys[i]) { 1316 key_free(options.identity_keys[i]); 1317 options.identity_keys[i] = NULL; 1318 } 1319 } 1320 for (i = 0; i < options.num_certificate_files; i++) { 1321 free(options.certificate_files[i]); 1322 options.certificate_files[i] = NULL; 1323 } 1324 1325 exit_status = compat20 ? ssh_session2() : ssh_session(); 1326 packet_close(); 1327 1328 if (options.control_path != NULL && muxserver_sock != -1) 1329 unlink(options.control_path); 1330 1331 /* Kill ProxyCommand if it is running. */ 1332 ssh_kill_proxy_command(); 1333 1334 return exit_status; 1335 } 1336 1337 static void 1338 control_persist_detach(void) 1339 { 1340 pid_t pid; 1341 int devnull; 1342 1343 debug("%s: backgrounding master process", __func__); 1344 1345 /* 1346 * master (current process) into the background, and make the 1347 * foreground process a client of the backgrounded master. 1348 */ 1349 switch ((pid = fork())) { 1350 case -1: 1351 fatal("%s: fork: %s", __func__, strerror(errno)); 1352 case 0: 1353 /* Child: master process continues mainloop */ 1354 break; 1355 default: 1356 /* Parent: set up mux slave to connect to backgrounded master */ 1357 debug2("%s: background process is %ld", __func__, (long)pid); 1358 stdin_null_flag = ostdin_null_flag; 1359 options.request_tty = orequest_tty; 1360 tty_flag = otty_flag; 1361 close(muxserver_sock); 1362 muxserver_sock = -1; 1363 options.control_master = SSHCTL_MASTER_NO; 1364 muxclient(options.control_path); 1365 /* muxclient() doesn't return on success. */ 1366 fatal("Failed to connect to new control master"); 1367 } 1368 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1369 error("%s: open(\"/dev/null\"): %s", __func__, 1370 strerror(errno)); 1371 } else { 1372 if (dup2(devnull, STDIN_FILENO) == -1 || 1373 dup2(devnull, STDOUT_FILENO) == -1) 1374 error("%s: dup2: %s", __func__, strerror(errno)); 1375 if (devnull > STDERR_FILENO) 1376 close(devnull); 1377 } 1378 daemon(1, 1); 1379 setproctitle("%s [mux]", options.control_path); 1380 } 1381 1382 /* Do fork() after authentication. Used by "ssh -f" */ 1383 static void 1384 fork_postauth(void) 1385 { 1386 if (need_controlpersist_detach) 1387 control_persist_detach(); 1388 debug("forking to background"); 1389 fork_after_authentication_flag = 0; 1390 if (daemon(1, 1) < 0) 1391 fatal("daemon() failed: %.200s", strerror(errno)); 1392 } 1393 1394 /* Callback for remote forward global requests */ 1395 static void 1396 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) 1397 { 1398 struct Forward *rfwd = (struct Forward *)ctxt; 1399 1400 /* XXX verbose() on failure? */ 1401 debug("remote forward %s for: listen %s%s%d, connect %s:%d", 1402 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1403 rfwd->listen_path ? rfwd->listen_path : 1404 rfwd->listen_host ? rfwd->listen_host : "", 1405 (rfwd->listen_path || rfwd->listen_host) ? ":" : "", 1406 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path : 1407 rfwd->connect_host, rfwd->connect_port); 1408 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) { 1409 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1410 rfwd->allocated_port = packet_get_int(); 1411 logit("Allocated port %u for remote forward to %s:%d", 1412 rfwd->allocated_port, 1413 rfwd->connect_host, rfwd->connect_port); 1414 channel_update_permitted_opens(rfwd->handle, 1415 rfwd->allocated_port); 1416 } else { 1417 channel_update_permitted_opens(rfwd->handle, -1); 1418 } 1419 } 1420 1421 if (type == SSH2_MSG_REQUEST_FAILURE) { 1422 if (options.exit_on_forward_failure) { 1423 if (rfwd->listen_path != NULL) 1424 fatal("Error: remote port forwarding failed " 1425 "for listen path %s", rfwd->listen_path); 1426 else 1427 fatal("Error: remote port forwarding failed " 1428 "for listen port %d", rfwd->listen_port); 1429 } else { 1430 if (rfwd->listen_path != NULL) 1431 logit("Warning: remote port forwarding failed " 1432 "for listen path %s", rfwd->listen_path); 1433 else 1434 logit("Warning: remote port forwarding failed " 1435 "for listen port %d", rfwd->listen_port); 1436 } 1437 } 1438 if (++remote_forward_confirms_received == options.num_remote_forwards) { 1439 debug("All remote forwarding requests processed"); 1440 if (fork_after_authentication_flag) 1441 fork_postauth(); 1442 } 1443 } 1444 1445 static void 1446 client_cleanup_stdio_fwd(int id, void *arg) 1447 { 1448 debug("stdio forwarding: done"); 1449 cleanup_exit(0); 1450 } 1451 1452 static void 1453 ssh_stdio_confirm(int id, int success, void *arg) 1454 { 1455 if (!success) 1456 fatal("stdio forwarding failed"); 1457 } 1458 1459 static void 1460 ssh_init_stdio_forwarding(void) 1461 { 1462 Channel *c; 1463 int in, out; 1464 1465 if (stdio_forward_host == NULL) 1466 return; 1467 if (!compat20) 1468 fatal("stdio forwarding require Protocol 2"); 1469 1470 debug3("%s: %s:%d", __func__, stdio_forward_host, stdio_forward_port); 1471 1472 if ((in = dup(STDIN_FILENO)) < 0 || 1473 (out = dup(STDOUT_FILENO)) < 0) 1474 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1475 if ((c = channel_connect_stdio_fwd(stdio_forward_host, 1476 stdio_forward_port, in, out)) == NULL) 1477 fatal("%s: channel_connect_stdio_fwd failed", __func__); 1478 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0); 1479 channel_register_open_confirm(c->self, ssh_stdio_confirm, NULL); 1480 } 1481 1482 static void 1483 ssh_init_forwarding(void) 1484 { 1485 int success = 0; 1486 int i; 1487 1488 /* Initiate local TCP/IP port forwardings. */ 1489 for (i = 0; i < options.num_local_forwards; i++) { 1490 debug("Local connections to %.200s:%d forwarded to remote " 1491 "address %.200s:%d", 1492 (options.local_forwards[i].listen_path != NULL) ? 1493 options.local_forwards[i].listen_path : 1494 (options.local_forwards[i].listen_host == NULL) ? 1495 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") : 1496 options.local_forwards[i].listen_host, 1497 options.local_forwards[i].listen_port, 1498 (options.local_forwards[i].connect_path != NULL) ? 1499 options.local_forwards[i].connect_path : 1500 options.local_forwards[i].connect_host, 1501 options.local_forwards[i].connect_port); 1502 success += channel_setup_local_fwd_listener( 1503 &options.local_forwards[i], &options.fwd_opts); 1504 } 1505 if (i > 0 && success != i && options.exit_on_forward_failure) 1506 fatal("Could not request local forwarding."); 1507 if (i > 0 && success == 0) 1508 error("Could not request local forwarding."); 1509 1510 /* Initiate remote TCP/IP port forwardings. */ 1511 for (i = 0; i < options.num_remote_forwards; i++) { 1512 debug("Remote connections from %.200s:%d forwarded to " 1513 "local address %.200s:%d", 1514 (options.remote_forwards[i].listen_path != NULL) ? 1515 options.remote_forwards[i].listen_path : 1516 (options.remote_forwards[i].listen_host == NULL) ? 1517 "LOCALHOST" : options.remote_forwards[i].listen_host, 1518 options.remote_forwards[i].listen_port, 1519 (options.remote_forwards[i].connect_path != NULL) ? 1520 options.remote_forwards[i].connect_path : 1521 options.remote_forwards[i].connect_host, 1522 options.remote_forwards[i].connect_port); 1523 options.remote_forwards[i].handle = 1524 channel_request_remote_forwarding( 1525 &options.remote_forwards[i]); 1526 if (options.remote_forwards[i].handle < 0) { 1527 if (options.exit_on_forward_failure) 1528 fatal("Could not request remote forwarding."); 1529 else 1530 logit("Warning: Could not request remote " 1531 "forwarding."); 1532 } else { 1533 client_register_global_confirm(ssh_confirm_remote_forward, 1534 &options.remote_forwards[i]); 1535 } 1536 } 1537 1538 /* Initiate tunnel forwarding. */ 1539 if (options.tun_open != SSH_TUNMODE_NO) { 1540 if (client_request_tun_fwd(options.tun_open, 1541 options.tun_local, options.tun_remote) == -1) { 1542 if (options.exit_on_forward_failure) 1543 fatal("Could not request tunnel forwarding."); 1544 else 1545 error("Could not request tunnel forwarding."); 1546 } 1547 } 1548 } 1549 1550 static void 1551 check_agent_present(void) 1552 { 1553 int r; 1554 1555 if (options.forward_agent) { 1556 /* Clear agent forwarding if we don't have an agent. */ 1557 if ((r = ssh_get_authentication_socket(NULL)) != 0) { 1558 options.forward_agent = 0; 1559 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1560 debug("ssh_get_authentication_socket: %s", 1561 ssh_err(r)); 1562 } 1563 } 1564 } 1565 1566 static int 1567 ssh_session(void) 1568 { 1569 int type; 1570 int interactive = 0; 1571 int have_tty = 0; 1572 struct winsize ws; 1573 char *cp; 1574 const char *display; 1575 1576 /* Enable compression if requested. */ 1577 if (options.compression) { 1578 debug("Requesting compression at level %d.", 1579 options.compression_level); 1580 1581 if (options.compression_level < 1 || 1582 options.compression_level > 9) 1583 fatal("Compression level must be from 1 (fast) to " 1584 "9 (slow, best)."); 1585 1586 /* Send the request. */ 1587 packet_start(SSH_CMSG_REQUEST_COMPRESSION); 1588 packet_put_int(options.compression_level); 1589 packet_send(); 1590 packet_write_wait(); 1591 type = packet_read(); 1592 if (type == SSH_SMSG_SUCCESS) 1593 packet_start_compression(options.compression_level); 1594 else if (type == SSH_SMSG_FAILURE) 1595 logit("Warning: Remote host refused compression."); 1596 else 1597 packet_disconnect("Protocol error waiting for " 1598 "compression response."); 1599 } 1600 /* Allocate a pseudo tty if appropriate. */ 1601 if (tty_flag) { 1602 debug("Requesting pty."); 1603 1604 /* Start the packet. */ 1605 packet_start(SSH_CMSG_REQUEST_PTY); 1606 1607 /* Store TERM in the packet. There is no limit on the 1608 length of the string. */ 1609 cp = getenv("TERM"); 1610 if (!cp) 1611 cp = ""; 1612 packet_put_cstring(cp); 1613 1614 /* Store window size in the packet. */ 1615 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 1616 memset(&ws, 0, sizeof(ws)); 1617 packet_put_int((u_int)ws.ws_row); 1618 packet_put_int((u_int)ws.ws_col); 1619 packet_put_int((u_int)ws.ws_xpixel); 1620 packet_put_int((u_int)ws.ws_ypixel); 1621 1622 /* Store tty modes in the packet. */ 1623 tty_make_modes(fileno(stdin), NULL); 1624 1625 /* Send the packet, and wait for it to leave. */ 1626 packet_send(); 1627 packet_write_wait(); 1628 1629 /* Read response from the server. */ 1630 type = packet_read(); 1631 if (type == SSH_SMSG_SUCCESS) { 1632 interactive = 1; 1633 have_tty = 1; 1634 } else if (type == SSH_SMSG_FAILURE) 1635 logit("Warning: Remote host failed or refused to " 1636 "allocate a pseudo tty."); 1637 else 1638 packet_disconnect("Protocol error waiting for pty " 1639 "request response."); 1640 } 1641 /* Request X11 forwarding if enabled and DISPLAY is set. */ 1642 display = getenv("DISPLAY"); 1643 if (display == NULL && options.forward_x11) 1644 debug("X11 forwarding requested but DISPLAY not set"); 1645 if (options.forward_x11 && display != NULL) { 1646 char *proto, *data; 1647 /* Get reasonable local authentication information. */ 1648 client_x11_get_proto(display, options.xauth_location, 1649 options.forward_x11_trusted, 1650 options.forward_x11_timeout, 1651 &proto, &data); 1652 /* Request forwarding with authentication spoofing. */ 1653 debug("Requesting X11 forwarding with authentication " 1654 "spoofing."); 1655 x11_request_forwarding_with_spoofing(0, display, proto, 1656 data, 0); 1657 /* Read response from the server. */ 1658 type = packet_read(); 1659 if (type == SSH_SMSG_SUCCESS) { 1660 interactive = 1; 1661 } else if (type == SSH_SMSG_FAILURE) { 1662 logit("Warning: Remote host denied X11 forwarding."); 1663 } else { 1664 packet_disconnect("Protocol error waiting for X11 " 1665 "forwarding"); 1666 } 1667 } 1668 /* Tell the packet module whether this is an interactive session. */ 1669 packet_set_interactive(interactive, 1670 options.ip_qos_interactive, options.ip_qos_bulk); 1671 1672 /* Request authentication agent forwarding if appropriate. */ 1673 check_agent_present(); 1674 1675 if (options.forward_agent) { 1676 debug("Requesting authentication agent forwarding."); 1677 auth_request_forwarding(); 1678 1679 /* Read response from the server. */ 1680 type = packet_read(); 1681 packet_check_eom(); 1682 if (type != SSH_SMSG_SUCCESS) 1683 logit("Warning: Remote host denied authentication agent forwarding."); 1684 } 1685 1686 /* Initiate port forwardings. */ 1687 ssh_init_stdio_forwarding(); 1688 ssh_init_forwarding(); 1689 1690 /* Execute a local command */ 1691 if (options.local_command != NULL && 1692 options.permit_local_command) 1693 ssh_local_cmd(options.local_command); 1694 1695 /* 1696 * If requested and we are not interested in replies to remote 1697 * forwarding requests, then let ssh continue in the background. 1698 */ 1699 if (fork_after_authentication_flag) { 1700 if (options.exit_on_forward_failure && 1701 options.num_remote_forwards > 0) { 1702 debug("deferring postauth fork until remote forward " 1703 "confirmation received"); 1704 } else 1705 fork_postauth(); 1706 } 1707 1708 /* 1709 * If a command was specified on the command line, execute the 1710 * command now. Otherwise request the server to start a shell. 1711 */ 1712 if (buffer_len(&command) > 0) { 1713 int len = buffer_len(&command); 1714 if (len > 900) 1715 len = 900; 1716 debug("Sending command: %.*s", len, 1717 (u_char *)buffer_ptr(&command)); 1718 packet_start(SSH_CMSG_EXEC_CMD); 1719 packet_put_string(buffer_ptr(&command), buffer_len(&command)); 1720 packet_send(); 1721 packet_write_wait(); 1722 } else { 1723 debug("Requesting shell."); 1724 packet_start(SSH_CMSG_EXEC_SHELL); 1725 packet_send(); 1726 packet_write_wait(); 1727 } 1728 1729 /* Enter the interactive session. */ 1730 return client_loop(have_tty, tty_flag ? 1731 options.escape_char : SSH_ESCAPECHAR_NONE, 0); 1732 } 1733 1734 /* request pty/x11/agent/tcpfwd/shell for channel */ 1735 static void 1736 ssh_session2_setup(int id, int success, void *arg) 1737 { 1738 extern char **environ; 1739 const char *display; 1740 int interactive = tty_flag; 1741 1742 if (!success) 1743 return; /* No need for error message, channels code sens one */ 1744 1745 display = getenv("DISPLAY"); 1746 if (display == NULL && options.forward_x11) 1747 debug("X11 forwarding requested but DISPLAY not set"); 1748 if (options.forward_x11 && display != NULL) { 1749 char *proto, *data; 1750 /* Get reasonable local authentication information. */ 1751 client_x11_get_proto(display, options.xauth_location, 1752 options.forward_x11_trusted, 1753 options.forward_x11_timeout, &proto, &data); 1754 /* Request forwarding with authentication spoofing. */ 1755 debug("Requesting X11 forwarding with authentication " 1756 "spoofing."); 1757 x11_request_forwarding_with_spoofing(id, display, proto, 1758 data, 1); 1759 client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN); 1760 /* XXX exit_on_forward_failure */ 1761 interactive = 1; 1762 } 1763 1764 check_agent_present(); 1765 if (options.forward_agent) { 1766 debug("Requesting authentication agent forwarding."); 1767 channel_request_start(id, "auth-agent-req@openssh.com", 0); 1768 packet_send(); 1769 } 1770 1771 /* Tell the packet module whether this is an interactive session. */ 1772 packet_set_interactive(interactive, 1773 options.ip_qos_interactive, options.ip_qos_bulk); 1774 1775 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), 1776 NULL, fileno(stdin), &command, environ); 1777 } 1778 1779 /* open new channel for a session */ 1780 static int 1781 ssh_session2_open(void) 1782 { 1783 Channel *c; 1784 int window, packetmax, in, out, err; 1785 1786 if (stdin_null_flag) { 1787 in = open(_PATH_DEVNULL, O_RDONLY); 1788 } else { 1789 in = dup(STDIN_FILENO); 1790 } 1791 out = dup(STDOUT_FILENO); 1792 err = dup(STDERR_FILENO); 1793 1794 if (in < 0 || out < 0 || err < 0) 1795 fatal("dup() in/out/err failed"); 1796 1797 /* enable nonblocking unless tty */ 1798 if (!isatty(in)) 1799 set_nonblock(in); 1800 if (!isatty(out)) 1801 set_nonblock(out); 1802 if (!isatty(err)) 1803 set_nonblock(err); 1804 1805 window = CHAN_SES_WINDOW_DEFAULT; 1806 packetmax = CHAN_SES_PACKET_DEFAULT; 1807 if (tty_flag) { 1808 window >>= 1; 1809 packetmax >>= 1; 1810 } 1811 c = channel_new( 1812 "session", SSH_CHANNEL_OPENING, in, out, err, 1813 window, packetmax, CHAN_EXTENDED_WRITE, 1814 "client-session", /*nonblock*/0); 1815 1816 debug3("ssh_session2_open: channel_new: %d", c->self); 1817 1818 channel_send_open(c->self); 1819 if (!no_shell_flag) 1820 channel_register_open_confirm(c->self, 1821 ssh_session2_setup, NULL); 1822 1823 return c->self; 1824 } 1825 1826 static int 1827 ssh_session2(void) 1828 { 1829 int id = -1; 1830 1831 /* XXX should be pre-session */ 1832 if (!options.control_persist) 1833 ssh_init_stdio_forwarding(); 1834 ssh_init_forwarding(); 1835 1836 /* Start listening for multiplex clients */ 1837 muxserver_listen(); 1838 1839 /* 1840 * If we are in control persist mode and have a working mux listen 1841 * socket, then prepare to background ourselves and have a foreground 1842 * client attach as a control slave. 1843 * NB. we must save copies of the flags that we override for 1844 * the backgrounding, since we defer attachment of the slave until 1845 * after the connection is fully established (in particular, 1846 * async rfwd replies have been received for ExitOnForwardFailure). 1847 */ 1848 if (options.control_persist && muxserver_sock != -1) { 1849 ostdin_null_flag = stdin_null_flag; 1850 ono_shell_flag = no_shell_flag; 1851 orequest_tty = options.request_tty; 1852 otty_flag = tty_flag; 1853 stdin_null_flag = 1; 1854 no_shell_flag = 1; 1855 tty_flag = 0; 1856 if (!fork_after_authentication_flag) 1857 need_controlpersist_detach = 1; 1858 fork_after_authentication_flag = 1; 1859 } 1860 /* 1861 * ControlPersist mux listen socket setup failed, attempt the 1862 * stdio forward setup that we skipped earlier. 1863 */ 1864 if (options.control_persist && muxserver_sock == -1) 1865 ssh_init_stdio_forwarding(); 1866 1867 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) 1868 id = ssh_session2_open(); 1869 else { 1870 packet_set_interactive( 1871 options.control_master == SSHCTL_MASTER_NO, 1872 options.ip_qos_interactive, options.ip_qos_bulk); 1873 } 1874 1875 /* If we don't expect to open a new session, then disallow it */ 1876 if (options.control_master == SSHCTL_MASTER_NO && 1877 (datafellows & SSH_NEW_OPENSSH)) { 1878 debug("Requesting no-more-sessions@openssh.com"); 1879 packet_start(SSH2_MSG_GLOBAL_REQUEST); 1880 packet_put_cstring("no-more-sessions@openssh.com"); 1881 packet_put_char(0); 1882 packet_send(); 1883 } 1884 1885 /* Execute a local command */ 1886 if (options.local_command != NULL && 1887 options.permit_local_command) 1888 ssh_local_cmd(options.local_command); 1889 1890 /* 1891 * If requested and we are not interested in replies to remote 1892 * forwarding requests, then let ssh continue in the background. 1893 */ 1894 if (fork_after_authentication_flag) { 1895 if (options.exit_on_forward_failure && 1896 options.num_remote_forwards > 0) { 1897 debug("deferring postauth fork until remote forward " 1898 "confirmation received"); 1899 } else 1900 fork_postauth(); 1901 } 1902 1903 if (options.use_roaming) 1904 request_roaming(); 1905 1906 return client_loop(tty_flag, tty_flag ? 1907 options.escape_char : SSH_ESCAPECHAR_NONE, id); 1908 } 1909 1910 /* Loads all IdentityFile and CertificateFile keys */ 1911 static void 1912 load_public_identity_files(void) 1913 { 1914 char *filename, *cp, thishost[NI_MAXHOST]; 1915 char *pwdir = NULL, *pwname = NULL; 1916 Key *public; 1917 struct passwd *pw; 1918 int i; 1919 u_int n_ids, n_certs; 1920 char *identity_files[SSH_MAX_IDENTITY_FILES]; 1921 Key *identity_keys[SSH_MAX_IDENTITY_FILES]; 1922 char *certificate_files[SSH_MAX_CERTIFICATE_FILES]; 1923 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES]; 1924 #ifdef ENABLE_PKCS11 1925 Key **keys; 1926 int nkeys; 1927 #endif /* PKCS11 */ 1928 1929 n_ids = n_certs = 0; 1930 memset(identity_files, 0, sizeof(identity_files)); 1931 memset(identity_keys, 0, sizeof(identity_keys)); 1932 memset(certificate_files, 0, sizeof(certificate_files)); 1933 memset(certificates, 0, sizeof(certificates)); 1934 1935 #ifdef ENABLE_PKCS11 1936 if (options.pkcs11_provider != NULL && 1937 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 1938 (pkcs11_init(!options.batch_mode) == 0) && 1939 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 1940 &keys)) > 0) { 1941 for (i = 0; i < nkeys; i++) { 1942 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 1943 key_free(keys[i]); 1944 continue; 1945 } 1946 identity_keys[n_ids] = keys[i]; 1947 identity_files[n_ids] = 1948 xstrdup(options.pkcs11_provider); /* XXX */ 1949 n_ids++; 1950 } 1951 free(keys); 1952 } 1953 #endif /* ENABLE_PKCS11 */ 1954 if ((pw = getpwuid(original_real_uid)) == NULL) 1955 fatal("load_public_identity_files: getpwuid failed"); 1956 pwname = xstrdup(pw->pw_name); 1957 pwdir = xstrdup(pw->pw_dir); 1958 if (gethostname(thishost, sizeof(thishost)) == -1) 1959 fatal("load_public_identity_files: gethostname: %s", 1960 strerror(errno)); 1961 for (i = 0; i < options.num_identity_files; i++) { 1962 if (n_ids >= SSH_MAX_IDENTITY_FILES || 1963 strcasecmp(options.identity_files[i], "none") == 0) { 1964 free(options.identity_files[i]); 1965 options.identity_files[i] = NULL; 1966 continue; 1967 } 1968 cp = tilde_expand_filename(options.identity_files[i], 1969 original_real_uid); 1970 filename = percent_expand(cp, "d", pwdir, 1971 "u", pwname, "l", thishost, "h", host, 1972 "r", options.user, (char *)NULL); 1973 free(cp); 1974 public = key_load_public(filename, NULL); 1975 debug("identity file %s type %d", filename, 1976 public ? public->type : -1); 1977 free(options.identity_files[i]); 1978 identity_files[n_ids] = filename; 1979 identity_keys[n_ids] = public; 1980 1981 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 1982 continue; 1983 1984 /* 1985 * If no certificates have been explicitly listed then try 1986 * to add the default certificate variant too. 1987 */ 1988 if (options.num_certificate_files != 0) 1989 continue; 1990 xasprintf(&cp, "%s-cert", filename); 1991 public = key_load_public(cp, NULL); 1992 debug("identity file %s type %d", cp, 1993 public ? public->type : -1); 1994 if (public == NULL) { 1995 free(cp); 1996 continue; 1997 } 1998 if (!key_is_cert(public)) { 1999 debug("%s: key %s type %s is not a certificate", 2000 __func__, cp, key_type(public)); 2001 key_free(public); 2002 free(cp); 2003 continue; 2004 } 2005 identity_keys[n_ids] = public; 2006 identity_files[n_ids] = cp; 2007 n_ids++; 2008 } 2009 2010 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES) 2011 fatal("%s: too many certificates", __func__); 2012 for (i = 0; i < options.num_certificate_files; i++) { 2013 cp = tilde_expand_filename(options.certificate_files[i], 2014 original_real_uid); 2015 filename = percent_expand(cp, "d", pwdir, 2016 "u", pwname, "l", thishost, "h", host, 2017 "r", options.user, (char *)NULL); 2018 free(cp); 2019 2020 public = key_load_public(filename, NULL); 2021 debug("certificate file %s type %d", filename, 2022 public ? public->type : -1); 2023 free(options.certificate_files[i]); 2024 options.certificate_files[i] = NULL; 2025 if (public == NULL) { 2026 free(filename); 2027 continue; 2028 } 2029 if (!key_is_cert(public)) { 2030 debug("%s: key %s type %s is not a certificate", 2031 __func__, filename, key_type(public)); 2032 key_free(public); 2033 free(filename); 2034 continue; 2035 } 2036 certificate_files[n_certs] = filename; 2037 certificates[n_certs] = public; 2038 ++n_certs; 2039 } 2040 2041 options.num_identity_files = n_ids; 2042 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 2043 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 2044 2045 options.num_certificate_files = n_certs; 2046 memcpy(options.certificate_files, 2047 certificate_files, sizeof(certificate_files)); 2048 memcpy(options.certificates, certificates, sizeof(certificates)); 2049 2050 explicit_bzero(pwname, strlen(pwname)); 2051 free(pwname); 2052 explicit_bzero(pwdir, strlen(pwdir)); 2053 free(pwdir); 2054 } 2055 2056 static void 2057 main_sigchld_handler(int sig) 2058 { 2059 int save_errno = errno; 2060 pid_t pid; 2061 int status; 2062 2063 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 2064 (pid < 0 && errno == EINTR)) 2065 ; 2066 2067 signal(sig, main_sigchld_handler); 2068 errno = save_errno; 2069 } 2070