1 /* $OpenBSD: ssh.c,v 1.407 2014/07/17 07:22:19 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 "includes.h" 44 45 #include <sys/types.h> 46 #ifdef HAVE_SYS_STAT_H 47 # include <sys/stat.h> 48 #endif 49 #include <sys/resource.h> 50 #include <sys/ioctl.h> 51 #include <sys/param.h> 52 #include <sys/socket.h> 53 #include <sys/wait.h> 54 55 #include <ctype.h> 56 #include <errno.h> 57 #include <fcntl.h> 58 #include <netdb.h> 59 #ifdef HAVE_PATHS_H 60 #include <paths.h> 61 #endif 62 #include <pwd.h> 63 #include <signal.h> 64 #include <stdarg.h> 65 #include <stddef.h> 66 #include <stdio.h> 67 #include <stdlib.h> 68 #include <string.h> 69 #include <unistd.h> 70 71 #include <netinet/in.h> 72 #include <arpa/inet.h> 73 74 #ifdef WITH_OPENSSL 75 #include <openssl/evp.h> 76 #include <openssl/err.h> 77 #endif 78 #include "openbsd-compat/openssl-compat.h" 79 #include "openbsd-compat/sys-queue.h" 80 81 #include "xmalloc.h" 82 #include "ssh.h" 83 #include "ssh1.h" 84 #include "ssh2.h" 85 #include "canohost.h" 86 #include "compat.h" 87 #include "cipher.h" 88 #include "digest.h" 89 #include "packet.h" 90 #include "buffer.h" 91 #include "channels.h" 92 #include "key.h" 93 #include "authfd.h" 94 #include "authfile.h" 95 #include "pathnames.h" 96 #include "dispatch.h" 97 #include "clientloop.h" 98 #include "log.h" 99 #include "misc.h" 100 #include "readconf.h" 101 #include "sshconnect.h" 102 #include "kex.h" 103 #include "mac.h" 104 #include "sshpty.h" 105 #include "match.h" 106 #include "msg.h" 107 #include "uidswap.h" 108 #include "roaming.h" 109 #include "version.h" 110 111 #ifdef ENABLE_PKCS11 112 #include "ssh-pkcs11.h" 113 #endif 114 115 extern char *__progname; 116 117 /* Saves a copy of argv for setproctitle emulation */ 118 #ifndef HAVE_SETPROCTITLE 119 static char **saved_av; 120 #endif 121 122 /* Flag indicating whether debug mode is on. May be set on the command line. */ 123 int debug_flag = 0; 124 125 /* Flag indicating whether a tty should be requested */ 126 int tty_flag = 0; 127 128 /* don't exec a shell */ 129 int no_shell_flag = 0; 130 131 /* 132 * Flag indicating that nothing should be read from stdin. This can be set 133 * on the command line. 134 */ 135 int stdin_null_flag = 0; 136 137 /* 138 * Flag indicating that the current process should be backgrounded and 139 * a new slave launched in the foreground for ControlPersist. 140 */ 141 int need_controlpersist_detach = 0; 142 143 /* Copies of flags for ControlPersist foreground slave */ 144 int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty; 145 146 /* 147 * Flag indicating that ssh should fork after authentication. This is useful 148 * so that the passphrase can be entered manually, and then ssh goes to the 149 * background. 150 */ 151 int fork_after_authentication_flag = 0; 152 153 /* forward stdio to remote host and port */ 154 char *stdio_forward_host = NULL; 155 int stdio_forward_port = 0; 156 157 /* 158 * General data structure for command line options and options configurable 159 * in configuration files. See readconf.h. 160 */ 161 Options options; 162 163 /* optional user configfile */ 164 char *config = NULL; 165 166 /* 167 * Name of the host we are connecting to. This is the name given on the 168 * command line, or the HostName specified for the user-supplied name in a 169 * configuration file. 170 */ 171 char *host; 172 173 /* socket address the host resolves to */ 174 struct sockaddr_storage hostaddr; 175 176 /* Private host keys. */ 177 Sensitive sensitive_data; 178 179 /* Original real UID. */ 180 uid_t original_real_uid; 181 uid_t original_effective_uid; 182 183 /* command to be executed */ 184 Buffer command; 185 186 /* Should we execute a command or invoke a subsystem? */ 187 int subsystem_flag = 0; 188 189 /* # of replies received for global requests */ 190 static int remote_forward_confirms_received = 0; 191 192 /* mux.c */ 193 extern int muxserver_sock; 194 extern u_int muxclient_command; 195 196 /* Prints a help message to the user. This function never returns. */ 197 198 static void 199 usage(void) 200 { 201 fprintf(stderr, 202 "usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n" 203 " [-D [bind_address:]port] [-E log_file] [-e escape_char]\n" 204 " [-F configfile] [-I pkcs11] [-i identity_file]\n" 205 " [-L [bind_address:]port:host:hostport] [-l login_name] [-m mac_spec]\n" 206 " [-O ctl_cmd] [-o option] [-p port]\n" 207 " [-Q cipher | cipher-auth | mac | kex | key]\n" 208 " [-R [bind_address:]port:host:hostport] [-S ctl_path] [-W host:port]\n" 209 " [-w local_tun[:remote_tun]] [user@]hostname [command]\n" 210 ); 211 exit(255); 212 } 213 214 static int ssh_session(void); 215 static int ssh_session2(void); 216 static void load_public_identity_files(void); 217 static void main_sigchld_handler(int); 218 219 /* from muxclient.c */ 220 void muxclient(const char *); 221 void muxserver_listen(void); 222 223 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 224 static void 225 tilde_expand_paths(char **paths, u_int num_paths) 226 { 227 u_int i; 228 char *cp; 229 230 for (i = 0; i < num_paths; i++) { 231 cp = tilde_expand_filename(paths[i], original_real_uid); 232 free(paths[i]); 233 paths[i] = cp; 234 } 235 } 236 237 /* 238 * Attempt to resolve a host name / port to a set of addresses and 239 * optionally return any CNAMEs encountered along the way. 240 * Returns NULL on failure. 241 * NB. this function must operate with a options having undefined members. 242 */ 243 static struct addrinfo * 244 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen) 245 { 246 char strport[NI_MAXSERV]; 247 struct addrinfo hints, *res; 248 int gaierr, loglevel = SYSLOG_LEVEL_DEBUG1; 249 250 if (port <= 0) 251 port = default_ssh_port(); 252 253 snprintf(strport, sizeof strport, "%u", port); 254 memset(&hints, 0, sizeof(hints)); 255 hints.ai_family = options.address_family == -1 ? 256 AF_UNSPEC : options.address_family; 257 hints.ai_socktype = SOCK_STREAM; 258 if (cname != NULL) 259 hints.ai_flags = AI_CANONNAME; 260 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 261 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) 262 loglevel = SYSLOG_LEVEL_ERROR; 263 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", 264 __progname, name, ssh_gai_strerror(gaierr)); 265 return NULL; 266 } 267 if (cname != NULL && res->ai_canonname != NULL) { 268 if (strlcpy(cname, res->ai_canonname, clen) >= clen) { 269 error("%s: host \"%s\" cname \"%s\" too long (max %lu)", 270 __func__, name, res->ai_canonname, (u_long)clen); 271 if (clen > 0) 272 *cname = '\0'; 273 } 274 } 275 return res; 276 } 277 278 /* 279 * Check whether the cname is a permitted replacement for the hostname 280 * and perform the replacement if it is. 281 * NB. this function must operate with a options having undefined members. 282 */ 283 static int 284 check_follow_cname(char **namep, const char *cname) 285 { 286 int i; 287 struct allowed_cname *rule; 288 289 if (*cname == '\0' || options.num_permitted_cnames == 0 || 290 strcmp(*namep, cname) == 0) 291 return 0; 292 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 293 return 0; 294 /* 295 * Don't attempt to canonicalize names that will be interpreted by 296 * a proxy unless the user specifically requests so. 297 */ 298 if (!option_clear_or_none(options.proxy_command) && 299 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 300 return 0; 301 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname); 302 for (i = 0; i < options.num_permitted_cnames; i++) { 303 rule = options.permitted_cnames + i; 304 if (match_pattern_list(*namep, rule->source_list, 305 strlen(rule->source_list), 1) != 1 || 306 match_pattern_list(cname, rule->target_list, 307 strlen(rule->target_list), 1) != 1) 308 continue; 309 verbose("Canonicalized DNS aliased hostname " 310 "\"%s\" => \"%s\"", *namep, cname); 311 free(*namep); 312 *namep = xstrdup(cname); 313 return 1; 314 } 315 return 0; 316 } 317 318 /* 319 * Attempt to resolve the supplied hostname after applying the user's 320 * canonicalization rules. Returns the address list for the host or NULL 321 * if no name was found after canonicalization. 322 * NB. this function must operate with a options having undefined members. 323 */ 324 static struct addrinfo * 325 resolve_canonicalize(char **hostp, int port) 326 { 327 int i, ndots; 328 char *cp, *fullhost, cname_target[NI_MAXHOST]; 329 struct addrinfo *addrs; 330 331 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 332 return NULL; 333 334 /* 335 * Don't attempt to canonicalize names that will be interpreted by 336 * a proxy unless the user specifically requests so. 337 */ 338 if (!option_clear_or_none(options.proxy_command) && 339 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 340 return NULL; 341 342 /* Don't apply canonicalization to sufficiently-qualified hostnames */ 343 ndots = 0; 344 for (cp = *hostp; *cp != '\0'; cp++) { 345 if (*cp == '.') 346 ndots++; 347 } 348 if (ndots > options.canonicalize_max_dots) { 349 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)", 350 __func__, *hostp, options.canonicalize_max_dots); 351 return NULL; 352 } 353 /* Attempt each supplied suffix */ 354 for (i = 0; i < options.num_canonical_domains; i++) { 355 *cname_target = '\0'; 356 xasprintf(&fullhost, "%s.%s.", *hostp, 357 options.canonical_domains[i]); 358 debug3("%s: attempting \"%s\" => \"%s\"", __func__, 359 *hostp, fullhost); 360 if ((addrs = resolve_host(fullhost, port, 0, 361 cname_target, sizeof(cname_target))) == NULL) { 362 free(fullhost); 363 continue; 364 } 365 /* Remove trailing '.' */ 366 fullhost[strlen(fullhost) - 1] = '\0'; 367 /* Follow CNAME if requested */ 368 if (!check_follow_cname(&fullhost, cname_target)) { 369 debug("Canonicalized hostname \"%s\" => \"%s\"", 370 *hostp, fullhost); 371 } 372 free(*hostp); 373 *hostp = fullhost; 374 return addrs; 375 } 376 if (!options.canonicalize_fallback_local) 377 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); 378 debug2("%s: host %s not found in any suffix", __func__, *hostp); 379 return NULL; 380 } 381 382 /* 383 * Read per-user configuration file. Ignore the system wide config 384 * file if the user specifies a config file on the command line. 385 */ 386 static void 387 process_config_files(struct passwd *pw) 388 { 389 char buf[MAXPATHLEN]; 390 int r; 391 392 if (config != NULL) { 393 if (strcasecmp(config, "none") != 0 && 394 !read_config_file(config, pw, host, &options, 395 SSHCONF_USERCONF)) 396 fatal("Can't open user config file %.100s: " 397 "%.100s", config, strerror(errno)); 398 } else { 399 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 400 _PATH_SSH_USER_CONFFILE); 401 if (r > 0 && (size_t)r < sizeof(buf)) 402 (void)read_config_file(buf, pw, host, &options, 403 SSHCONF_CHECKPERM|SSHCONF_USERCONF); 404 405 /* Read systemwide configuration file after user config. */ 406 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, host, 407 &options, 0); 408 } 409 } 410 411 /* 412 * Main program for the ssh client. 413 */ 414 int 415 main(int ac, char **av) 416 { 417 int i, r, opt, exit_status, use_syslog; 418 char *p, *cp, *line, *argv0, buf[MAXPATHLEN], *host_arg, *logfile; 419 char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 420 char cname[NI_MAXHOST]; 421 struct stat st; 422 struct passwd *pw; 423 int timeout_ms; 424 extern int optind, optreset; 425 extern char *optarg; 426 struct Forward fwd; 427 struct addrinfo *addrs = NULL; 428 struct ssh_digest_ctx *md; 429 u_char conn_hash[SSH_DIGEST_MAX_LENGTH]; 430 char *conn_hash_hex; 431 432 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 433 sanitise_stdfd(); 434 435 __progname = ssh_get_progname(av[0]); 436 437 #ifndef HAVE_SETPROCTITLE 438 /* Prepare for later setproctitle emulation */ 439 /* Save argv so it isn't clobbered by setproctitle() emulation */ 440 saved_av = xcalloc(ac + 1, sizeof(*saved_av)); 441 for (i = 0; i < ac; i++) 442 saved_av[i] = xstrdup(av[i]); 443 saved_av[i] = NULL; 444 compat_init_setproctitle(ac, av); 445 av = saved_av; 446 #endif 447 448 /* 449 * Discard other fds that are hanging around. These can cause problem 450 * with backgrounded ssh processes started by ControlPersist. 451 */ 452 closefrom(STDERR_FILENO + 1); 453 454 /* 455 * Save the original real uid. It will be needed later (uid-swapping 456 * may clobber the real uid). 457 */ 458 original_real_uid = getuid(); 459 original_effective_uid = geteuid(); 460 461 /* 462 * Use uid-swapping to give up root privileges for the duration of 463 * option processing. We will re-instantiate the rights when we are 464 * ready to create the privileged port, and will permanently drop 465 * them when the port has been created (actually, when the connection 466 * has been made, as we may need to create the port several times). 467 */ 468 PRIV_END; 469 470 #ifdef HAVE_SETRLIMIT 471 /* If we are installed setuid root be careful to not drop core. */ 472 if (original_real_uid != original_effective_uid) { 473 struct rlimit rlim; 474 rlim.rlim_cur = rlim.rlim_max = 0; 475 if (setrlimit(RLIMIT_CORE, &rlim) < 0) 476 fatal("setrlimit failed: %.100s", strerror(errno)); 477 } 478 #endif 479 /* Get user data. */ 480 pw = getpwuid(original_real_uid); 481 if (!pw) { 482 logit("No user exists for uid %lu", (u_long)original_real_uid); 483 exit(255); 484 } 485 /* Take a copy of the returned structure. */ 486 pw = pwcopy(pw); 487 488 /* 489 * Set our umask to something reasonable, as some files are created 490 * with the default umask. This will make them world-readable but 491 * writable only by the owner, which is ok for all files for which we 492 * don't set the modes explicitly. 493 */ 494 umask(022); 495 496 /* 497 * Initialize option structure to indicate that no values have been 498 * set. 499 */ 500 initialize_options(&options); 501 502 /* Parse command-line arguments. */ 503 host = NULL; 504 use_syslog = 0; 505 logfile = NULL; 506 argv0 = av[0]; 507 508 again: 509 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 510 "ACD:E:F:I:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { 511 switch (opt) { 512 case '1': 513 options.protocol = SSH_PROTO_1; 514 break; 515 case '2': 516 options.protocol = SSH_PROTO_2; 517 break; 518 case '4': 519 options.address_family = AF_INET; 520 break; 521 case '6': 522 options.address_family = AF_INET6; 523 break; 524 case 'n': 525 stdin_null_flag = 1; 526 break; 527 case 'f': 528 fork_after_authentication_flag = 1; 529 stdin_null_flag = 1; 530 break; 531 case 'x': 532 options.forward_x11 = 0; 533 break; 534 case 'X': 535 options.forward_x11 = 1; 536 break; 537 case 'y': 538 use_syslog = 1; 539 break; 540 case 'E': 541 logfile = xstrdup(optarg); 542 break; 543 case 'Y': 544 options.forward_x11 = 1; 545 options.forward_x11_trusted = 1; 546 break; 547 case 'g': 548 options.fwd_opts.gateway_ports = 1; 549 break; 550 case 'O': 551 if (stdio_forward_host != NULL) 552 fatal("Cannot specify multiplexing " 553 "command with -W"); 554 else if (muxclient_command != 0) 555 fatal("Multiplexing command already specified"); 556 if (strcmp(optarg, "check") == 0) 557 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 558 else if (strcmp(optarg, "forward") == 0) 559 muxclient_command = SSHMUX_COMMAND_FORWARD; 560 else if (strcmp(optarg, "exit") == 0) 561 muxclient_command = SSHMUX_COMMAND_TERMINATE; 562 else if (strcmp(optarg, "stop") == 0) 563 muxclient_command = SSHMUX_COMMAND_STOP; 564 else if (strcmp(optarg, "cancel") == 0) 565 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 566 else 567 fatal("Invalid multiplex command."); 568 break; 569 case 'P': /* deprecated */ 570 options.use_privileged_port = 0; 571 break; 572 case 'Q': 573 cp = NULL; 574 if (strcmp(optarg, "cipher") == 0) 575 cp = cipher_alg_list('\n', 0); 576 else if (strcmp(optarg, "cipher-auth") == 0) 577 cp = cipher_alg_list('\n', 1); 578 else if (strcmp(optarg, "mac") == 0) 579 cp = mac_alg_list('\n'); 580 else if (strcmp(optarg, "kex") == 0) 581 cp = kex_alg_list('\n'); 582 else if (strcmp(optarg, "key") == 0) 583 cp = key_alg_list(0, 0); 584 else if (strcmp(optarg, "key-cert") == 0) 585 cp = key_alg_list(1, 0); 586 else if (strcmp(optarg, "key-plain") == 0) 587 cp = key_alg_list(0, 1); 588 if (cp == NULL) 589 fatal("Unsupported query \"%s\"", optarg); 590 printf("%s\n", cp); 591 free(cp); 592 exit(0); 593 break; 594 case 'a': 595 options.forward_agent = 0; 596 break; 597 case 'A': 598 options.forward_agent = 1; 599 break; 600 case 'k': 601 options.gss_deleg_creds = 0; 602 break; 603 case 'K': 604 options.gss_authentication = 1; 605 options.gss_deleg_creds = 1; 606 break; 607 case 'i': 608 if (stat(optarg, &st) < 0) { 609 fprintf(stderr, "Warning: Identity file %s " 610 "not accessible: %s.\n", optarg, 611 strerror(errno)); 612 break; 613 } 614 add_identity_file(&options, NULL, optarg, 1); 615 break; 616 case 'I': 617 #ifdef ENABLE_PKCS11 618 options.pkcs11_provider = xstrdup(optarg); 619 #else 620 fprintf(stderr, "no support for PKCS#11.\n"); 621 #endif 622 break; 623 case 't': 624 if (options.request_tty == REQUEST_TTY_YES) 625 options.request_tty = REQUEST_TTY_FORCE; 626 else 627 options.request_tty = REQUEST_TTY_YES; 628 break; 629 case 'v': 630 if (debug_flag == 0) { 631 debug_flag = 1; 632 options.log_level = SYSLOG_LEVEL_DEBUG1; 633 } else { 634 if (options.log_level < SYSLOG_LEVEL_DEBUG3) 635 options.log_level++; 636 } 637 break; 638 case 'V': 639 fprintf(stderr, "%s%s %s, %s\n", SSH_RELEASE, 640 SSH_VERSION_HPN, SSH_VERSION_DRAGONFLY, 641 #ifdef WITH_OPENSSL 642 SSLeay_version(SSLEAY_VERSION) 643 #else 644 "without OpenSSL" 645 #endif 646 ); 647 if (opt == 'V') 648 exit(0); 649 break; 650 case 'w': 651 if (options.tun_open == -1) 652 options.tun_open = SSH_TUNMODE_DEFAULT; 653 options.tun_local = a2tun(optarg, &options.tun_remote); 654 if (options.tun_local == SSH_TUNID_ERR) { 655 fprintf(stderr, 656 "Bad tun device '%s'\n", optarg); 657 exit(255); 658 } 659 break; 660 case 'W': 661 if (stdio_forward_host != NULL) 662 fatal("stdio forward already specified"); 663 if (muxclient_command != 0) 664 fatal("Cannot specify stdio forward with -O"); 665 if (parse_forward(&fwd, optarg, 1, 0)) { 666 stdio_forward_host = fwd.listen_host; 667 stdio_forward_port = fwd.listen_port; 668 free(fwd.connect_host); 669 } else { 670 fprintf(stderr, 671 "Bad stdio forwarding specification '%s'\n", 672 optarg); 673 exit(255); 674 } 675 options.request_tty = REQUEST_TTY_NO; 676 no_shell_flag = 1; 677 options.clear_forwardings = 1; 678 options.exit_on_forward_failure = 1; 679 break; 680 case 'q': 681 options.log_level = SYSLOG_LEVEL_QUIET; 682 break; 683 case 'e': 684 if (optarg[0] == '^' && optarg[2] == 0 && 685 (u_char) optarg[1] >= 64 && 686 (u_char) optarg[1] < 128) 687 options.escape_char = (u_char) optarg[1] & 31; 688 else if (strlen(optarg) == 1) 689 options.escape_char = (u_char) optarg[0]; 690 else if (strcmp(optarg, "none") == 0) 691 options.escape_char = SSH_ESCAPECHAR_NONE; 692 else { 693 fprintf(stderr, "Bad escape character '%s'.\n", 694 optarg); 695 exit(255); 696 } 697 break; 698 case 'c': 699 if (ciphers_valid(optarg)) { 700 /* SSH2 only */ 701 options.ciphers = xstrdup(optarg); 702 options.cipher = SSH_CIPHER_INVALID; 703 } else { 704 /* SSH1 only */ 705 options.cipher = cipher_number(optarg); 706 if (options.cipher == -1) { 707 fprintf(stderr, 708 "Unknown cipher type '%s'\n", 709 optarg); 710 exit(255); 711 } 712 if (options.cipher == SSH_CIPHER_3DES) 713 options.ciphers = "3des-cbc"; 714 else if (options.cipher == SSH_CIPHER_BLOWFISH) 715 options.ciphers = "blowfish-cbc"; 716 else 717 options.ciphers = (char *)-1; 718 } 719 break; 720 case 'm': 721 if (mac_valid(optarg)) 722 options.macs = xstrdup(optarg); 723 else { 724 fprintf(stderr, "Unknown mac type '%s'\n", 725 optarg); 726 exit(255); 727 } 728 break; 729 case 'M': 730 if (options.control_master == SSHCTL_MASTER_YES) 731 options.control_master = SSHCTL_MASTER_ASK; 732 else 733 options.control_master = SSHCTL_MASTER_YES; 734 break; 735 case 'p': 736 options.port = a2port(optarg); 737 if (options.port <= 0) { 738 fprintf(stderr, "Bad port '%s'\n", optarg); 739 exit(255); 740 } 741 break; 742 case 'l': 743 options.user = optarg; 744 break; 745 746 case 'L': 747 if (parse_forward(&fwd, optarg, 0, 0)) 748 add_local_forward(&options, &fwd); 749 else { 750 fprintf(stderr, 751 "Bad local forwarding specification '%s'\n", 752 optarg); 753 exit(255); 754 } 755 break; 756 757 case 'R': 758 if (parse_forward(&fwd, optarg, 0, 1)) { 759 add_remote_forward(&options, &fwd); 760 } else { 761 fprintf(stderr, 762 "Bad remote forwarding specification " 763 "'%s'\n", optarg); 764 exit(255); 765 } 766 break; 767 768 case 'D': 769 if (parse_forward(&fwd, optarg, 1, 0)) { 770 add_local_forward(&options, &fwd); 771 } else { 772 fprintf(stderr, 773 "Bad dynamic forwarding specification " 774 "'%s'\n", optarg); 775 exit(255); 776 } 777 break; 778 779 case 'C': 780 options.compression = 1; 781 break; 782 case 'N': 783 no_shell_flag = 1; 784 options.request_tty = REQUEST_TTY_NO; 785 break; 786 case 'T': 787 options.request_tty = REQUEST_TTY_NO; 788 /* ensure that the user doesn't try to backdoor a */ 789 /* null cipher switch on an interactive session */ 790 /* so explicitly disable it no matter what */ 791 options.none_switch=0; 792 break; 793 case 'o': 794 line = xstrdup(optarg); 795 if (process_config_line(&options, pw, host ? host : "", 796 line, "command-line", 0, NULL, SSHCONF_USERCONF) 797 != 0) 798 exit(255); 799 free(line); 800 break; 801 case 's': 802 subsystem_flag = 1; 803 break; 804 case 'S': 805 if (options.control_path != NULL) 806 free(options.control_path); 807 options.control_path = xstrdup(optarg); 808 break; 809 case 'b': 810 options.bind_address = optarg; 811 break; 812 case 'F': 813 config = optarg; 814 break; 815 default: 816 usage(); 817 } 818 } 819 820 ac -= optind; 821 av += optind; 822 823 if (ac > 0 && !host) { 824 if (strrchr(*av, '@')) { 825 p = xstrdup(*av); 826 cp = strrchr(p, '@'); 827 if (cp == NULL || cp == p) 828 usage(); 829 options.user = p; 830 *cp = '\0'; 831 host = xstrdup(++cp); 832 } else 833 host = xstrdup(*av); 834 if (ac > 1) { 835 optind = optreset = 1; 836 goto again; 837 } 838 ac--, av++; 839 } 840 841 /* Check that we got a host name. */ 842 if (!host) 843 usage(); 844 845 host_arg = xstrdup(host); 846 847 #ifdef WITH_OPENSSL 848 OpenSSL_add_all_algorithms(); 849 ERR_load_crypto_strings(); 850 #endif 851 852 /* Initialize the command to execute on remote host. */ 853 buffer_init(&command); 854 855 /* 856 * Save the command to execute on the remote host in a buffer. There 857 * is no limit on the length of the command, except by the maximum 858 * packet size. Also sets the tty flag if there is no command. 859 */ 860 if (!ac) { 861 /* No command specified - execute shell on a tty. */ 862 if (subsystem_flag) { 863 fprintf(stderr, 864 "You must specify a subsystem to invoke.\n"); 865 usage(); 866 } 867 } else { 868 /* A command has been specified. Store it into the buffer. */ 869 for (i = 0; i < ac; i++) { 870 if (i) 871 buffer_append(&command, " ", 1); 872 buffer_append(&command, av[i], strlen(av[i])); 873 } 874 } 875 876 /* Cannot fork to background if no command. */ 877 if (fork_after_authentication_flag && buffer_len(&command) == 0 && 878 !no_shell_flag) 879 fatal("Cannot fork into background without a command " 880 "to execute."); 881 882 /* 883 * Initialize "log" output. Since we are the client all output 884 * goes to stderr unless otherwise specified by -y or -E. 885 */ 886 if (use_syslog && logfile != NULL) 887 fatal("Can't specify both -y and -E"); 888 if (logfile != NULL) { 889 log_redirect_stderr_to(logfile); 890 free(logfile); 891 } 892 log_init(argv0, 893 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, 894 SYSLOG_FACILITY_USER, !use_syslog); 895 896 if (debug_flag) 897 logit("%s, %s", SSH_RELEASE, 898 #ifdef WITH_OPENSSL 899 SSLeay_version(SSLEAY_VERSION) 900 #else 901 "without OpenSSL" 902 #endif 903 ); 904 905 /* Parse the configuration files */ 906 process_config_files(pw); 907 908 /* Hostname canonicalisation needs a few options filled. */ 909 fill_default_options_for_canonicalization(&options); 910 911 /* If the user has replaced the hostname then take it into use now */ 912 if (options.hostname != NULL) { 913 /* NB. Please keep in sync with readconf.c:match_cfg_line() */ 914 cp = percent_expand(options.hostname, 915 "h", host, (char *)NULL); 916 free(host); 917 host = cp; 918 } 919 920 /* If canonicalization requested then try to apply it */ 921 lowercase(host); 922 if (options.canonicalize_hostname != SSH_CANONICALISE_NO) 923 addrs = resolve_canonicalize(&host, options.port); 924 925 /* 926 * If CanonicalizePermittedCNAMEs have been specified but 927 * other canonicalization did not happen (by not being requested 928 * or by failing with fallback) then the hostname may still be changed 929 * as a result of CNAME following. 930 * 931 * Try to resolve the bare hostname name using the system resolver's 932 * usual search rules and then apply the CNAME follow rules. 933 * 934 * Skip the lookup if a ProxyCommand is being used unless the user 935 * has specifically requested canonicalisation for this case via 936 * CanonicalizeHostname=always 937 */ 938 if (addrs == NULL && options.num_permitted_cnames != 0 && 939 (option_clear_or_none(options.proxy_command) || 940 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { 941 if ((addrs = resolve_host(host, options.port, 942 option_clear_or_none(options.proxy_command), 943 cname, sizeof(cname))) == NULL) { 944 /* Don't fatal proxied host names not in the DNS */ 945 if (option_clear_or_none(options.proxy_command)) 946 cleanup_exit(255); /* logged in resolve_host */ 947 } else 948 check_follow_cname(&host, cname); 949 } 950 951 /* 952 * If the target hostname has changed as a result of canonicalisation 953 * then re-parse the configuration files as new stanzas may match. 954 */ 955 if (strcasecmp(host_arg, host) != 0) { 956 debug("Hostname has changed; re-reading configuration"); 957 process_config_files(pw); 958 } 959 960 /* Fill configuration defaults. */ 961 fill_default_options(&options); 962 963 if (options.port == 0) 964 options.port = default_ssh_port(); 965 channel_set_af(options.address_family); 966 967 /* Tidy and check options */ 968 if (options.host_key_alias != NULL) 969 lowercase(options.host_key_alias); 970 if (options.proxy_command != NULL && 971 strcmp(options.proxy_command, "-") == 0 && 972 options.proxy_use_fdpass) 973 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); 974 #ifndef HAVE_CYGWIN 975 if (original_effective_uid != 0) 976 options.use_privileged_port = 0; 977 #endif 978 979 /* reinit */ 980 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog); 981 982 if (options.request_tty == REQUEST_TTY_YES || 983 options.request_tty == REQUEST_TTY_FORCE) 984 tty_flag = 1; 985 986 /* Allocate a tty by default if no command specified. */ 987 if (buffer_len(&command) == 0) 988 tty_flag = options.request_tty != REQUEST_TTY_NO; 989 990 /* Force no tty */ 991 if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0) 992 tty_flag = 0; 993 /* Do not allocate a tty if stdin is not a tty. */ 994 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 995 options.request_tty != REQUEST_TTY_FORCE) { 996 if (tty_flag) 997 logit("Pseudo-terminal will not be allocated because " 998 "stdin is not a terminal."); 999 tty_flag = 0; 1000 } 1001 1002 seed_rng(); 1003 1004 if (options.user == NULL) 1005 options.user = xstrdup(pw->pw_name); 1006 1007 if (gethostname(thishost, sizeof(thishost)) == -1) 1008 fatal("gethostname: %s", strerror(errno)); 1009 strlcpy(shorthost, thishost, sizeof(shorthost)); 1010 shorthost[strcspn(thishost, ".")] = '\0'; 1011 snprintf(portstr, sizeof(portstr), "%d", options.port); 1012 1013 if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL || 1014 ssh_digest_update(md, thishost, strlen(thishost)) < 0 || 1015 ssh_digest_update(md, host, strlen(host)) < 0 || 1016 ssh_digest_update(md, portstr, strlen(portstr)) < 0 || 1017 ssh_digest_update(md, options.user, strlen(options.user)) < 0 || 1018 ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0) 1019 fatal("%s: mux digest failed", __func__); 1020 ssh_digest_free(md); 1021 conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1)); 1022 1023 if (options.local_command != NULL) { 1024 debug3("expanding LocalCommand: %s", options.local_command); 1025 cp = options.local_command; 1026 options.local_command = percent_expand(cp, 1027 "C", conn_hash_hex, 1028 "L", shorthost, 1029 "d", pw->pw_dir, 1030 "h", host, 1031 "l", thishost, 1032 "n", host_arg, 1033 "p", portstr, 1034 "r", options.user, 1035 "u", pw->pw_name, 1036 (char *)NULL); 1037 debug3("expanded LocalCommand: %s", options.local_command); 1038 free(cp); 1039 } 1040 1041 if (options.control_path != NULL) { 1042 cp = tilde_expand_filename(options.control_path, 1043 original_real_uid); 1044 free(options.control_path); 1045 options.control_path = percent_expand(cp, 1046 "C", conn_hash_hex, 1047 "L", shorthost, 1048 "h", host, 1049 "l", thishost, 1050 "n", host_arg, 1051 "p", portstr, 1052 "r", options.user, 1053 "u", pw->pw_name, 1054 (char *)NULL); 1055 free(cp); 1056 } 1057 free(conn_hash_hex); 1058 1059 if (muxclient_command != 0 && options.control_path == NULL) 1060 fatal("No ControlPath specified for \"-O\" command"); 1061 if (options.control_path != NULL) 1062 muxclient(options.control_path); 1063 1064 /* 1065 * If hostname canonicalisation was not enabled, then we may not 1066 * have yet resolved the hostname. Do so now. 1067 */ 1068 if (addrs == NULL && options.proxy_command == NULL) { 1069 if ((addrs = resolve_host(host, options.port, 1, 1070 cname, sizeof(cname))) == NULL) 1071 cleanup_exit(255); /* resolve_host logs the error */ 1072 } 1073 1074 timeout_ms = options.connection_timeout * 1000; 1075 1076 /* Open a connection to the remote host. */ 1077 if (ssh_connect(host, addrs, &hostaddr, options.port, 1078 options.address_family, options.connection_attempts, 1079 &timeout_ms, options.tcp_keep_alive, 1080 options.use_privileged_port) != 0) 1081 exit(255); 1082 1083 if (addrs != NULL) 1084 freeaddrinfo(addrs); 1085 1086 packet_set_timeout(options.server_alive_interval, 1087 options.server_alive_count_max); 1088 1089 if (timeout_ms > 0) 1090 debug3("timeout: %d ms remain after connect", timeout_ms); 1091 1092 /* 1093 * If we successfully made the connection, load the host private key 1094 * in case we will need it later for combined rsa-rhosts 1095 * authentication. This must be done before releasing extra 1096 * privileges, because the file is only readable by root. 1097 * If we cannot access the private keys, load the public keys 1098 * instead and try to execute the ssh-keysign helper instead. 1099 */ 1100 sensitive_data.nkeys = 0; 1101 sensitive_data.keys = NULL; 1102 sensitive_data.external_keysign = 0; 1103 if (options.rhosts_rsa_authentication || 1104 options.hostbased_authentication) { 1105 sensitive_data.nkeys = 9; 1106 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 1107 sizeof(Key)); 1108 for (i = 0; i < sensitive_data.nkeys; i++) 1109 sensitive_data.keys[i] = NULL; 1110 1111 PRIV_START; 1112 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, 1113 _PATH_HOST_KEY_FILE, "", NULL, NULL); 1114 sensitive_data.keys[1] = key_load_private_cert(KEY_DSA, 1115 _PATH_HOST_DSA_KEY_FILE, "", NULL); 1116 #ifdef OPENSSL_HAS_ECC 1117 sensitive_data.keys[2] = key_load_private_cert(KEY_ECDSA, 1118 _PATH_HOST_ECDSA_KEY_FILE, "", NULL); 1119 #endif 1120 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA, 1121 _PATH_HOST_RSA_KEY_FILE, "", NULL); 1122 sensitive_data.keys[4] = key_load_private_cert(KEY_ED25519, 1123 _PATH_HOST_ED25519_KEY_FILE, "", NULL); 1124 sensitive_data.keys[5] = key_load_private_type(KEY_DSA, 1125 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); 1126 #ifdef OPENSSL_HAS_ECC 1127 sensitive_data.keys[6] = key_load_private_type(KEY_ECDSA, 1128 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL); 1129 #endif 1130 sensitive_data.keys[7] = key_load_private_type(KEY_RSA, 1131 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); 1132 sensitive_data.keys[8] = key_load_private_type(KEY_ED25519, 1133 _PATH_HOST_ED25519_KEY_FILE, "", NULL, NULL); 1134 PRIV_END; 1135 1136 if (options.hostbased_authentication == 1 && 1137 sensitive_data.keys[0] == NULL && 1138 sensitive_data.keys[5] == NULL && 1139 sensitive_data.keys[6] == NULL && 1140 sensitive_data.keys[7] == NULL && 1141 sensitive_data.keys[8] == NULL) { 1142 sensitive_data.keys[1] = key_load_cert( 1143 _PATH_HOST_DSA_KEY_FILE); 1144 #ifdef OPENSSL_HAS_ECC 1145 sensitive_data.keys[2] = key_load_cert( 1146 _PATH_HOST_ECDSA_KEY_FILE); 1147 #endif 1148 sensitive_data.keys[3] = key_load_cert( 1149 _PATH_HOST_RSA_KEY_FILE); 1150 sensitive_data.keys[4] = key_load_cert( 1151 _PATH_HOST_ED25519_KEY_FILE); 1152 sensitive_data.keys[5] = key_load_public( 1153 _PATH_HOST_DSA_KEY_FILE, NULL); 1154 #ifdef OPENSSL_HAS_ECC 1155 sensitive_data.keys[6] = key_load_public( 1156 _PATH_HOST_ECDSA_KEY_FILE, NULL); 1157 #endif 1158 sensitive_data.keys[7] = key_load_public( 1159 _PATH_HOST_RSA_KEY_FILE, NULL); 1160 sensitive_data.keys[8] = key_load_public( 1161 _PATH_HOST_ED25519_KEY_FILE, NULL); 1162 sensitive_data.external_keysign = 1; 1163 } 1164 } 1165 /* 1166 * Get rid of any extra privileges that we may have. We will no 1167 * longer need them. Also, extra privileges could make it very hard 1168 * to read identity files and other non-world-readable files from the 1169 * user's home directory if it happens to be on a NFS volume where 1170 * root is mapped to nobody. 1171 */ 1172 if (original_effective_uid == 0) { 1173 PRIV_START; 1174 permanently_set_uid(pw); 1175 } 1176 1177 /* 1178 * Now that we are back to our own permissions, create ~/.ssh 1179 * directory if it doesn't already exist. 1180 */ 1181 if (config == NULL) { 1182 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 1183 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 1184 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) { 1185 #ifdef WITH_SELINUX 1186 ssh_selinux_setfscreatecon(buf); 1187 #endif 1188 if (mkdir(buf, 0700) < 0) 1189 error("Could not create directory '%.200s'.", 1190 buf); 1191 #ifdef WITH_SELINUX 1192 ssh_selinux_setfscreatecon(NULL); 1193 #endif 1194 } 1195 } 1196 /* load options.identity_files */ 1197 load_public_identity_files(); 1198 1199 /* Expand ~ in known host file names. */ 1200 tilde_expand_paths(options.system_hostfiles, 1201 options.num_system_hostfiles); 1202 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 1203 1204 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 1205 signal(SIGCHLD, main_sigchld_handler); 1206 1207 /* Log into the remote system. Never returns if the login fails. */ 1208 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, 1209 options.port, pw, timeout_ms); 1210 1211 if (packet_connection_is_on_socket()) { 1212 verbose("Authenticated to %s ([%s]:%d).", host, 1213 get_remote_ipaddr(), get_remote_port()); 1214 } else { 1215 verbose("Authenticated to %s (via proxy).", host); 1216 } 1217 1218 /* We no longer need the private host keys. Clear them now. */ 1219 if (sensitive_data.nkeys != 0) { 1220 for (i = 0; i < sensitive_data.nkeys; i++) { 1221 if (sensitive_data.keys[i] != NULL) { 1222 /* Destroys contents safely */ 1223 debug3("clear hostkey %d", i); 1224 key_free(sensitive_data.keys[i]); 1225 sensitive_data.keys[i] = NULL; 1226 } 1227 } 1228 free(sensitive_data.keys); 1229 } 1230 for (i = 0; i < options.num_identity_files; i++) { 1231 free(options.identity_files[i]); 1232 options.identity_files[i] = NULL; 1233 if (options.identity_keys[i]) { 1234 key_free(options.identity_keys[i]); 1235 options.identity_keys[i] = NULL; 1236 } 1237 } 1238 1239 exit_status = compat20 ? ssh_session2() : ssh_session(); 1240 packet_close(); 1241 1242 if (options.control_path != NULL && muxserver_sock != -1) 1243 unlink(options.control_path); 1244 1245 /* Kill ProxyCommand if it is running. */ 1246 ssh_kill_proxy_command(); 1247 1248 return exit_status; 1249 } 1250 1251 static void 1252 control_persist_detach(void) 1253 { 1254 pid_t pid; 1255 int devnull; 1256 1257 debug("%s: backgrounding master process", __func__); 1258 1259 /* 1260 * master (current process) into the background, and make the 1261 * foreground process a client of the backgrounded master. 1262 */ 1263 switch ((pid = fork())) { 1264 case -1: 1265 fatal("%s: fork: %s", __func__, strerror(errno)); 1266 case 0: 1267 /* Child: master process continues mainloop */ 1268 break; 1269 default: 1270 /* Parent: set up mux slave to connect to backgrounded master */ 1271 debug2("%s: background process is %ld", __func__, (long)pid); 1272 stdin_null_flag = ostdin_null_flag; 1273 options.request_tty = orequest_tty; 1274 tty_flag = otty_flag; 1275 close(muxserver_sock); 1276 muxserver_sock = -1; 1277 options.control_master = SSHCTL_MASTER_NO; 1278 muxclient(options.control_path); 1279 /* muxclient() doesn't return on success. */ 1280 fatal("Failed to connect to new control master"); 1281 } 1282 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1283 error("%s: open(\"/dev/null\"): %s", __func__, 1284 strerror(errno)); 1285 } else { 1286 if (dup2(devnull, STDIN_FILENO) == -1 || 1287 dup2(devnull, STDOUT_FILENO) == -1) 1288 error("%s: dup2: %s", __func__, strerror(errno)); 1289 if (devnull > STDERR_FILENO) 1290 close(devnull); 1291 } 1292 daemon(1, 1); 1293 setproctitle("%s [mux]", options.control_path); 1294 } 1295 1296 extern const EVP_CIPHER *evp_aes_ctr_mt(void); 1297 1298 /* Do fork() after authentication. Used by "ssh -f" */ 1299 static void 1300 fork_postauth(void) 1301 { 1302 if (need_controlpersist_detach) 1303 control_persist_detach(); 1304 debug("forking to background"); 1305 fork_after_authentication_flag = 0; 1306 if (daemon(1, 1) < 0) 1307 fatal("daemon() failed: %.200s", strerror(errno)); 1308 } 1309 1310 /* Callback for remote forward global requests */ 1311 static void 1312 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) 1313 { 1314 struct Forward *rfwd = (struct Forward *)ctxt; 1315 1316 /* XXX verbose() on failure? */ 1317 debug("remote forward %s for: listen %s%s%d, connect %s:%d", 1318 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1319 rfwd->listen_path ? rfwd->listen_path : 1320 rfwd->listen_host ? rfwd->listen_host : "", 1321 (rfwd->listen_path || rfwd->listen_host) ? ":" : "", 1322 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path : 1323 rfwd->connect_host, rfwd->connect_port); 1324 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) { 1325 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1326 rfwd->allocated_port = packet_get_int(); 1327 logit("Allocated port %u for remote forward to %s:%d", 1328 rfwd->allocated_port, 1329 rfwd->connect_host, rfwd->connect_port); 1330 channel_update_permitted_opens(rfwd->handle, 1331 rfwd->allocated_port); 1332 } else { 1333 channel_update_permitted_opens(rfwd->handle, -1); 1334 } 1335 } 1336 1337 if (type == SSH2_MSG_REQUEST_FAILURE) { 1338 if (options.exit_on_forward_failure) { 1339 if (rfwd->listen_path != NULL) 1340 fatal("Error: remote port forwarding failed " 1341 "for listen path %s", rfwd->listen_path); 1342 else 1343 fatal("Error: remote port forwarding failed " 1344 "for listen port %d", rfwd->listen_port); 1345 } else { 1346 if (rfwd->listen_path != NULL) 1347 logit("Warning: remote port forwarding failed " 1348 "for listen path %s", rfwd->listen_path); 1349 else 1350 logit("Warning: remote port forwarding failed " 1351 "for listen port %d", rfwd->listen_port); 1352 } 1353 } 1354 if (++remote_forward_confirms_received == options.num_remote_forwards) { 1355 debug("All remote forwarding requests processed"); 1356 if (fork_after_authentication_flag) 1357 fork_postauth(); 1358 } 1359 } 1360 1361 static void 1362 client_cleanup_stdio_fwd(int id, void *arg) 1363 { 1364 debug("stdio forwarding: done"); 1365 cleanup_exit(0); 1366 } 1367 1368 static void 1369 ssh_stdio_confirm(int id, int success, void *arg) 1370 { 1371 if (!success) 1372 fatal("stdio forwarding failed"); 1373 } 1374 1375 static void 1376 ssh_init_stdio_forwarding(void) 1377 { 1378 Channel *c; 1379 int in, out; 1380 1381 if (stdio_forward_host == NULL) 1382 return; 1383 if (!compat20) 1384 fatal("stdio forwarding require Protocol 2"); 1385 1386 debug3("%s: %s:%d", __func__, stdio_forward_host, stdio_forward_port); 1387 1388 if ((in = dup(STDIN_FILENO)) < 0 || 1389 (out = dup(STDOUT_FILENO)) < 0) 1390 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1391 if ((c = channel_connect_stdio_fwd(stdio_forward_host, 1392 stdio_forward_port, in, out)) == NULL) 1393 fatal("%s: channel_connect_stdio_fwd failed", __func__); 1394 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0); 1395 channel_register_open_confirm(c->self, ssh_stdio_confirm, NULL); 1396 } 1397 1398 static void 1399 ssh_init_forwarding(void) 1400 { 1401 int success = 0; 1402 int i; 1403 1404 /* Initiate local TCP/IP port forwardings. */ 1405 for (i = 0; i < options.num_local_forwards; i++) { 1406 debug("Local connections to %.200s:%d forwarded to remote " 1407 "address %.200s:%d", 1408 (options.local_forwards[i].listen_path != NULL) ? 1409 options.local_forwards[i].listen_path : 1410 (options.local_forwards[i].listen_host == NULL) ? 1411 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") : 1412 options.local_forwards[i].listen_host, 1413 options.local_forwards[i].listen_port, 1414 (options.local_forwards[i].connect_path != NULL) ? 1415 options.local_forwards[i].connect_path : 1416 options.local_forwards[i].connect_host, 1417 options.local_forwards[i].connect_port); 1418 success += channel_setup_local_fwd_listener( 1419 &options.local_forwards[i], &options.fwd_opts); 1420 } 1421 if (i > 0 && success != i && options.exit_on_forward_failure) 1422 fatal("Could not request local forwarding."); 1423 if (i > 0 && success == 0) 1424 error("Could not request local forwarding."); 1425 1426 /* Initiate remote TCP/IP port forwardings. */ 1427 for (i = 0; i < options.num_remote_forwards; i++) { 1428 debug("Remote connections from %.200s:%d forwarded to " 1429 "local address %.200s:%d", 1430 (options.remote_forwards[i].listen_path != NULL) ? 1431 options.remote_forwards[i].listen_path : 1432 (options.remote_forwards[i].listen_host == NULL) ? 1433 "LOCALHOST" : options.remote_forwards[i].listen_host, 1434 options.remote_forwards[i].listen_port, 1435 (options.remote_forwards[i].connect_path != NULL) ? 1436 options.remote_forwards[i].connect_path : 1437 options.remote_forwards[i].connect_host, 1438 options.remote_forwards[i].connect_port); 1439 options.remote_forwards[i].handle = 1440 channel_request_remote_forwarding( 1441 &options.remote_forwards[i]); 1442 if (options.remote_forwards[i].handle < 0) { 1443 if (options.exit_on_forward_failure) 1444 fatal("Could not request remote forwarding."); 1445 else 1446 logit("Warning: Could not request remote " 1447 "forwarding."); 1448 } else { 1449 client_register_global_confirm(ssh_confirm_remote_forward, 1450 &options.remote_forwards[i]); 1451 } 1452 } 1453 1454 /* Initiate tunnel forwarding. */ 1455 if (options.tun_open != SSH_TUNMODE_NO) { 1456 if (client_request_tun_fwd(options.tun_open, 1457 options.tun_local, options.tun_remote) == -1) { 1458 if (options.exit_on_forward_failure) 1459 fatal("Could not request tunnel forwarding."); 1460 else 1461 error("Could not request tunnel forwarding."); 1462 } 1463 } 1464 } 1465 1466 static void 1467 check_agent_present(void) 1468 { 1469 if (options.forward_agent) { 1470 /* Clear agent forwarding if we don't have an agent. */ 1471 if (!ssh_agent_present()) 1472 options.forward_agent = 0; 1473 } 1474 } 1475 1476 static int 1477 ssh_session(void) 1478 { 1479 int type; 1480 int interactive = 0; 1481 int have_tty = 0; 1482 struct winsize ws; 1483 char *cp; 1484 const char *display; 1485 1486 /* Enable compression if requested. */ 1487 if (options.compression) { 1488 debug("Requesting compression at level %d.", 1489 options.compression_level); 1490 1491 if (options.compression_level < 1 || 1492 options.compression_level > 9) 1493 fatal("Compression level must be from 1 (fast) to " 1494 "9 (slow, best)."); 1495 1496 /* Send the request. */ 1497 packet_start(SSH_CMSG_REQUEST_COMPRESSION); 1498 packet_put_int(options.compression_level); 1499 packet_send(); 1500 packet_write_wait(); 1501 type = packet_read(); 1502 if (type == SSH_SMSG_SUCCESS) 1503 packet_start_compression(options.compression_level); 1504 else if (type == SSH_SMSG_FAILURE) 1505 logit("Warning: Remote host refused compression."); 1506 else 1507 packet_disconnect("Protocol error waiting for " 1508 "compression response."); 1509 } 1510 /* Allocate a pseudo tty if appropriate. */ 1511 if (tty_flag) { 1512 debug("Requesting pty."); 1513 1514 /* Start the packet. */ 1515 packet_start(SSH_CMSG_REQUEST_PTY); 1516 1517 /* Store TERM in the packet. There is no limit on the 1518 length of the string. */ 1519 cp = getenv("TERM"); 1520 if (!cp) 1521 cp = ""; 1522 packet_put_cstring(cp); 1523 1524 /* Store window size in the packet. */ 1525 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 1526 memset(&ws, 0, sizeof(ws)); 1527 packet_put_int((u_int)ws.ws_row); 1528 packet_put_int((u_int)ws.ws_col); 1529 packet_put_int((u_int)ws.ws_xpixel); 1530 packet_put_int((u_int)ws.ws_ypixel); 1531 1532 /* Store tty modes in the packet. */ 1533 tty_make_modes(fileno(stdin), NULL); 1534 1535 /* Send the packet, and wait for it to leave. */ 1536 packet_send(); 1537 packet_write_wait(); 1538 1539 /* Read response from the server. */ 1540 type = packet_read(); 1541 if (type == SSH_SMSG_SUCCESS) { 1542 interactive = 1; 1543 have_tty = 1; 1544 } else if (type == SSH_SMSG_FAILURE) 1545 logit("Warning: Remote host failed or refused to " 1546 "allocate a pseudo tty."); 1547 else 1548 packet_disconnect("Protocol error waiting for pty " 1549 "request response."); 1550 } 1551 /* Request X11 forwarding if enabled and DISPLAY is set. */ 1552 display = getenv("DISPLAY"); 1553 if (options.forward_x11 && display != NULL) { 1554 char *proto, *data; 1555 /* Get reasonable local authentication information. */ 1556 client_x11_get_proto(display, options.xauth_location, 1557 options.forward_x11_trusted, 1558 options.forward_x11_timeout, 1559 &proto, &data); 1560 /* Request forwarding with authentication spoofing. */ 1561 debug("Requesting X11 forwarding with authentication " 1562 "spoofing."); 1563 x11_request_forwarding_with_spoofing(0, display, proto, 1564 data, 0); 1565 /* Read response from the server. */ 1566 type = packet_read(); 1567 if (type == SSH_SMSG_SUCCESS) { 1568 interactive = 1; 1569 } else if (type == SSH_SMSG_FAILURE) { 1570 logit("Warning: Remote host denied X11 forwarding."); 1571 } else { 1572 packet_disconnect("Protocol error waiting for X11 " 1573 "forwarding"); 1574 } 1575 } 1576 /* Tell the packet module whether this is an interactive session. */ 1577 packet_set_interactive(interactive, 1578 options.ip_qos_interactive, options.ip_qos_bulk); 1579 1580 /* Request authentication agent forwarding if appropriate. */ 1581 check_agent_present(); 1582 1583 if (options.forward_agent) { 1584 debug("Requesting authentication agent forwarding."); 1585 auth_request_forwarding(); 1586 1587 /* Read response from the server. */ 1588 type = packet_read(); 1589 packet_check_eom(); 1590 if (type != SSH_SMSG_SUCCESS) 1591 logit("Warning: Remote host denied authentication agent forwarding."); 1592 } 1593 1594 /* Initiate port forwardings. */ 1595 ssh_init_stdio_forwarding(); 1596 ssh_init_forwarding(); 1597 1598 /* Execute a local command */ 1599 if (options.local_command != NULL && 1600 options.permit_local_command) 1601 ssh_local_cmd(options.local_command); 1602 1603 /* 1604 * If requested and we are not interested in replies to remote 1605 * forwarding requests, then let ssh continue in the background. 1606 */ 1607 if (fork_after_authentication_flag) { 1608 if (options.exit_on_forward_failure && 1609 options.num_remote_forwards > 0) { 1610 debug("deferring postauth fork until remote forward " 1611 "confirmation received"); 1612 } else 1613 fork_postauth(); 1614 } 1615 1616 /* 1617 * If a command was specified on the command line, execute the 1618 * command now. Otherwise request the server to start a shell. 1619 */ 1620 if (buffer_len(&command) > 0) { 1621 int len = buffer_len(&command); 1622 if (len > 900) 1623 len = 900; 1624 debug("Sending command: %.*s", len, 1625 (u_char *)buffer_ptr(&command)); 1626 packet_start(SSH_CMSG_EXEC_CMD); 1627 packet_put_string(buffer_ptr(&command), buffer_len(&command)); 1628 packet_send(); 1629 packet_write_wait(); 1630 } else { 1631 debug("Requesting shell."); 1632 packet_start(SSH_CMSG_EXEC_SHELL); 1633 packet_send(); 1634 packet_write_wait(); 1635 } 1636 1637 /* Enter the interactive session. */ 1638 return client_loop(have_tty, tty_flag ? 1639 options.escape_char : SSH_ESCAPECHAR_NONE, 0); 1640 } 1641 1642 /* request pty/x11/agent/tcpfwd/shell for channel */ 1643 static void 1644 ssh_session2_setup(int id, int success, void *arg) 1645 { 1646 extern char **environ; 1647 const char *display; 1648 int interactive = tty_flag; 1649 1650 if (!success) 1651 return; /* No need for error message, channels code sens one */ 1652 1653 display = getenv("DISPLAY"); 1654 if (options.forward_x11 && display != NULL) { 1655 char *proto, *data; 1656 /* Get reasonable local authentication information. */ 1657 client_x11_get_proto(display, options.xauth_location, 1658 options.forward_x11_trusted, 1659 options.forward_x11_timeout, &proto, &data); 1660 /* Request forwarding with authentication spoofing. */ 1661 debug("Requesting X11 forwarding with authentication " 1662 "spoofing."); 1663 x11_request_forwarding_with_spoofing(id, display, proto, 1664 data, 1); 1665 client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN); 1666 /* XXX exit_on_forward_failure */ 1667 interactive = 1; 1668 } 1669 1670 check_agent_present(); 1671 if (options.forward_agent) { 1672 debug("Requesting authentication agent forwarding."); 1673 channel_request_start(id, "auth-agent-req@openssh.com", 0); 1674 packet_send(); 1675 } 1676 1677 /* Tell the packet module whether this is an interactive session. */ 1678 packet_set_interactive(interactive, 1679 options.ip_qos_interactive, options.ip_qos_bulk); 1680 1681 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), 1682 NULL, fileno(stdin), &command, environ); 1683 } 1684 1685 /* open new channel for a session */ 1686 static int 1687 ssh_session2_open(void) 1688 { 1689 Channel *c; 1690 int window, packetmax, in, out, err; 1691 int sock; 1692 int socksize; 1693 int socksizelen = sizeof(int); 1694 1695 if (stdin_null_flag) { 1696 in = open(_PATH_DEVNULL, O_RDONLY); 1697 } else { 1698 in = dup(STDIN_FILENO); 1699 } 1700 out = dup(STDOUT_FILENO); 1701 err = dup(STDERR_FILENO); 1702 1703 if (in < 0 || out < 0 || err < 0) 1704 fatal("dup() in/out/err failed"); 1705 1706 /* enable nonblocking unless tty */ 1707 if (!isatty(in)) 1708 set_nonblock(in); 1709 if (!isatty(out)) 1710 set_nonblock(out); 1711 if (!isatty(err)) 1712 set_nonblock(err); 1713 1714 /* we need to check to see if what they want to do about buffer */ 1715 /* sizes here. In a hpn to nonhpn connection we want to limit */ 1716 /* the window size to something reasonable in case the far side */ 1717 /* has the large window bug. In hpn to hpn connection we want to */ 1718 /* use the max window size but allow the user to override it */ 1719 /* lastly if they disabled hpn then use the ssh std window size */ 1720 1721 /* so why don't we just do a getsockopt() here and set the */ 1722 /* ssh window to that? In the case of a autotuning receive */ 1723 /* window the window would get stuck at the initial buffer */ 1724 /* size generally less than 96k. Therefore we need to set the */ 1725 /* maximum ssh window size to the maximum hpn buffer size */ 1726 /* unless the user has specifically set the tcprcvbufpoll */ 1727 /* to no. In which case we *can* just set the window to the */ 1728 /* minimum of the hpn buffer size and tcp receive buffer size */ 1729 1730 if (tty_flag) 1731 options.hpn_buffer_size = CHAN_SES_WINDOW_DEFAULT; 1732 else 1733 options.hpn_buffer_size = 2*1024*1024; 1734 1735 if (datafellows & SSH_BUG_LARGEWINDOW) 1736 { 1737 debug("HPN to Non-HPN Connection"); 1738 } 1739 else 1740 { 1741 if (options.tcp_rcv_buf_poll <= 0) 1742 { 1743 sock = socket(AF_INET, SOCK_STREAM, 0); 1744 getsockopt(sock, SOL_SOCKET, SO_RCVBUF, 1745 &socksize, &socksizelen); 1746 close(sock); 1747 debug("socksize %d", socksize); 1748 options.hpn_buffer_size = socksize; 1749 debug ("HPNBufferSize set to TCP RWIN: %d", options.hpn_buffer_size); 1750 } 1751 else 1752 { 1753 if (options.tcp_rcv_buf > 0) 1754 { 1755 /*create a socket but don't connect it */ 1756 /* we use that the get the rcv socket size */ 1757 sock = socket(AF_INET, SOCK_STREAM, 0); 1758 /* if they are using the tcp_rcv_buf option */ 1759 /* attempt to set the buffer size to that */ 1760 if (options.tcp_rcv_buf) 1761 setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void *)&options.tcp_rcv_buf, 1762 sizeof(options.tcp_rcv_buf)); 1763 getsockopt(sock, SOL_SOCKET, SO_RCVBUF, 1764 &socksize, &socksizelen); 1765 close(sock); 1766 debug("socksize %d", socksize); 1767 options.hpn_buffer_size = socksize; 1768 debug ("HPNBufferSize set to user TCPRcvBuf: %d", options.hpn_buffer_size); 1769 } 1770 } 1771 } 1772 1773 debug("Final hpn_buffer_size = %d", options.hpn_buffer_size); 1774 1775 window = options.hpn_buffer_size; 1776 1777 channel_set_hpn(options.hpn_disabled, options.hpn_buffer_size); 1778 1779 packetmax = CHAN_SES_PACKET_DEFAULT; 1780 if (tty_flag) { 1781 window = 4*CHAN_SES_PACKET_DEFAULT; 1782 window >>= 1; 1783 packetmax >>= 1; 1784 } 1785 c = channel_new( 1786 "session", SSH_CHANNEL_OPENING, in, out, err, 1787 window, packetmax, CHAN_EXTENDED_WRITE, 1788 "client-session", /*nonblock*/0); 1789 1790 if ((options.tcp_rcv_buf_poll > 0) && (!options.hpn_disabled)) { 1791 c->dynamic_window = 1; 1792 debug ("Enabled Dynamic Window Scaling"); 1793 } 1794 debug3("ssh_session2_open: channel_new: %d", c->self); 1795 1796 channel_send_open(c->self); 1797 if (!no_shell_flag) 1798 channel_register_open_confirm(c->self, 1799 ssh_session2_setup, NULL); 1800 1801 return c->self; 1802 } 1803 1804 static int 1805 ssh_session2(void) 1806 { 1807 int id = -1; 1808 1809 /* XXX should be pre-session */ 1810 if (!options.control_persist) 1811 ssh_init_stdio_forwarding(); 1812 ssh_init_forwarding(); 1813 1814 /* Start listening for multiplex clients */ 1815 muxserver_listen(); 1816 1817 /* 1818 * If we are in control persist mode and have a working mux listen 1819 * socket, then prepare to background ourselves and have a foreground 1820 * client attach as a control slave. 1821 * NB. we must save copies of the flags that we override for 1822 * the backgrounding, since we defer attachment of the slave until 1823 * after the connection is fully established (in particular, 1824 * async rfwd replies have been received for ExitOnForwardFailure). 1825 */ 1826 if (options.control_persist && muxserver_sock != -1) { 1827 ostdin_null_flag = stdin_null_flag; 1828 ono_shell_flag = no_shell_flag; 1829 orequest_tty = options.request_tty; 1830 otty_flag = tty_flag; 1831 stdin_null_flag = 1; 1832 no_shell_flag = 1; 1833 tty_flag = 0; 1834 if (!fork_after_authentication_flag) 1835 need_controlpersist_detach = 1; 1836 fork_after_authentication_flag = 1; 1837 } 1838 /* 1839 * ControlPersist mux listen socket setup failed, attempt the 1840 * stdio forward setup that we skipped earlier. 1841 */ 1842 if (options.control_persist && muxserver_sock == -1) 1843 ssh_init_stdio_forwarding(); 1844 1845 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) 1846 id = ssh_session2_open(); 1847 else { 1848 packet_set_interactive( 1849 options.control_master == SSHCTL_MASTER_NO, 1850 options.ip_qos_interactive, options.ip_qos_bulk); 1851 } 1852 1853 /* If we don't expect to open a new session, then disallow it */ 1854 if (options.control_master == SSHCTL_MASTER_NO && 1855 (datafellows & SSH_NEW_OPENSSH)) { 1856 debug("Requesting no-more-sessions@openssh.com"); 1857 packet_start(SSH2_MSG_GLOBAL_REQUEST); 1858 packet_put_cstring("no-more-sessions@openssh.com"); 1859 packet_put_char(0); 1860 packet_send(); 1861 } 1862 1863 /* Execute a local command */ 1864 if (options.local_command != NULL && 1865 options.permit_local_command) 1866 ssh_local_cmd(options.local_command); 1867 1868 /* 1869 * If requested and we are not interested in replies to remote 1870 * forwarding requests, then let ssh continue in the background. 1871 */ 1872 if (fork_after_authentication_flag) { 1873 if (options.exit_on_forward_failure && 1874 options.num_remote_forwards > 0) { 1875 debug("deferring postauth fork until remote forward " 1876 "confirmation received"); 1877 } else 1878 fork_postauth(); 1879 } 1880 1881 if (options.use_roaming) 1882 request_roaming(); 1883 1884 return client_loop(tty_flag, tty_flag ? 1885 options.escape_char : SSH_ESCAPECHAR_NONE, id); 1886 } 1887 1888 static void 1889 load_public_identity_files(void) 1890 { 1891 char *filename, *cp, thishost[NI_MAXHOST]; 1892 char *pwdir = NULL, *pwname = NULL; 1893 int i = 0; 1894 Key *public; 1895 struct passwd *pw; 1896 u_int n_ids; 1897 char *identity_files[SSH_MAX_IDENTITY_FILES]; 1898 Key *identity_keys[SSH_MAX_IDENTITY_FILES]; 1899 #ifdef ENABLE_PKCS11 1900 Key **keys; 1901 int nkeys; 1902 #endif /* PKCS11 */ 1903 1904 n_ids = 0; 1905 memset(identity_files, 0, sizeof(identity_files)); 1906 memset(identity_keys, 0, sizeof(identity_keys)); 1907 1908 #ifdef ENABLE_PKCS11 1909 if (options.pkcs11_provider != NULL && 1910 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 1911 (pkcs11_init(!options.batch_mode) == 0) && 1912 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 1913 &keys)) > 0) { 1914 for (i = 0; i < nkeys; i++) { 1915 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 1916 key_free(keys[i]); 1917 continue; 1918 } 1919 identity_keys[n_ids] = keys[i]; 1920 identity_files[n_ids] = 1921 xstrdup(options.pkcs11_provider); /* XXX */ 1922 n_ids++; 1923 } 1924 free(keys); 1925 } 1926 #endif /* ENABLE_PKCS11 */ 1927 if ((pw = getpwuid(original_real_uid)) == NULL) 1928 fatal("load_public_identity_files: getpwuid failed"); 1929 pwname = xstrdup(pw->pw_name); 1930 pwdir = xstrdup(pw->pw_dir); 1931 if (gethostname(thishost, sizeof(thishost)) == -1) 1932 fatal("load_public_identity_files: gethostname: %s", 1933 strerror(errno)); 1934 for (i = 0; i < options.num_identity_files; i++) { 1935 if (n_ids >= SSH_MAX_IDENTITY_FILES || 1936 strcasecmp(options.identity_files[i], "none") == 0) { 1937 free(options.identity_files[i]); 1938 continue; 1939 } 1940 cp = tilde_expand_filename(options.identity_files[i], 1941 original_real_uid); 1942 filename = percent_expand(cp, "d", pwdir, 1943 "u", pwname, "l", thishost, "h", host, 1944 "r", options.user, (char *)NULL); 1945 free(cp); 1946 public = key_load_public(filename, NULL); 1947 debug("identity file %s type %d", filename, 1948 public ? public->type : -1); 1949 free(options.identity_files[i]); 1950 identity_files[n_ids] = filename; 1951 identity_keys[n_ids] = public; 1952 1953 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 1954 continue; 1955 1956 /* Try to add the certificate variant too */ 1957 xasprintf(&cp, "%s-cert", filename); 1958 public = key_load_public(cp, NULL); 1959 debug("identity file %s type %d", cp, 1960 public ? public->type : -1); 1961 if (public == NULL) { 1962 free(cp); 1963 continue; 1964 } 1965 if (!key_is_cert(public)) { 1966 debug("%s: key %s type %s is not a certificate", 1967 __func__, cp, key_type(public)); 1968 key_free(public); 1969 free(cp); 1970 continue; 1971 } 1972 identity_keys[n_ids] = public; 1973 /* point to the original path, most likely the private key */ 1974 identity_files[n_ids] = xstrdup(filename); 1975 n_ids++; 1976 } 1977 options.num_identity_files = n_ids; 1978 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 1979 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 1980 1981 explicit_bzero(pwname, strlen(pwname)); 1982 free(pwname); 1983 explicit_bzero(pwdir, strlen(pwdir)); 1984 free(pwdir); 1985 } 1986 1987 static void 1988 main_sigchld_handler(int sig) 1989 { 1990 int save_errno = errno; 1991 pid_t pid; 1992 int status; 1993 1994 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 1995 (pid < 0 && errno == EINTR)) 1996 ; 1997 1998 signal(sig, main_sigchld_handler); 1999 errno = save_errno; 2000 } 2001