1 /* $OpenBSD: ssh.c,v 1.416 2015/03/03 06:48:58 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo (at) cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo (at) 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 (at) 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/socket.h> 52 #include <sys/wait.h> 53 54 #include <ctype.h> 55 #include <errno.h> 56 #include <fcntl.h> 57 #include <netdb.h> 58 #ifdef HAVE_PATHS_H 59 #include <paths.h> 60 #endif 61 #include <pwd.h> 62 #include <signal.h> 63 #include <stdarg.h> 64 #include <stddef.h> 65 #include <stdio.h> 66 #include <stdlib.h> 67 #include <string.h> 68 #include <unistd.h> 69 #include <limits.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 #include "ssherr.h" 111 112 #ifdef ENABLE_PKCS11 113 #include "ssh-pkcs11.h" 114 #endif 115 116 extern char *__progname; 117 118 /* Saves a copy of argv for setproctitle emulation */ 119 #ifndef HAVE_SETPROCTITLE 120 static char **saved_av; 121 #endif 122 123 /* Flag indicating whether debug mode is on. May be set on the command line. */ 124 int debug_flag = 0; 125 126 /* Flag indicating whether a tty should be requested */ 127 int tty_flag = 0; 128 129 /* don't exec a shell */ 130 int no_shell_flag = 0; 131 132 /* 133 * Flag indicating that nothing should be read from stdin. This can be set 134 * on the command line. 135 */ 136 int stdin_null_flag = 0; 137 138 /* 139 * Flag indicating that the current process should be backgrounded and 140 * a new slave launched in the foreground for ControlPersist. 141 */ 142 int need_controlpersist_detach = 0; 143 144 /* Copies of flags for ControlPersist foreground slave */ 145 int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty; 146 147 /* 148 * Flag indicating that ssh should fork after authentication. This is useful 149 * so that the passphrase can be entered manually, and then ssh goes to the 150 * background. 151 */ 152 int fork_after_authentication_flag = 0; 153 154 /* forward stdio to remote host and port */ 155 char *stdio_forward_host = NULL; 156 int stdio_forward_port = 0; 157 158 /* 159 * General data structure for command line options and options configurable 160 * in configuration files. See readconf.h. 161 */ 162 Options options; 163 164 /* optional user configfile */ 165 char *config = NULL; 166 167 /* 168 * Name of the host we are connecting to. This is the name given on the 169 * command line, or the HostName specified for the user-supplied name in a 170 * configuration file. 171 */ 172 char *host; 173 174 /* socket address the host resolves to */ 175 struct sockaddr_storage hostaddr; 176 177 /* Private host keys. */ 178 Sensitive sensitive_data; 179 180 /* Original real UID. */ 181 uid_t original_real_uid; 182 uid_t original_effective_uid; 183 184 /* command to be executed */ 185 Buffer command; 186 187 /* Should we execute a command or invoke a subsystem? */ 188 int subsystem_flag = 0; 189 190 /* # of replies received for global requests */ 191 static int remote_forward_confirms_received = 0; 192 193 /* mux.c */ 194 extern int muxserver_sock; 195 extern u_int muxclient_command; 196 197 /* Prints a help message to the user. This function never returns. */ 198 199 static void 200 usage(void) 201 { 202 fprintf(stderr, 203 "usage: ssh [-1246AaCfGgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n" 204 " [-D [bind_address:]port] [-E log_file] [-e escape_char]\n" 205 " [-F configfile] [-I pkcs11] [-i identity_file]\n" 206 " [-L [bind_address:]port:host:hostport] [-l login_name] [-m mac_spec]\n" 207 " [-O ctl_cmd] [-o option] [-p port]\n" 208 " [-Q cipher | cipher-auth | mac | kex | key]\n" 209 " [-R [bind_address:]port:host:hostport] [-S ctl_path] [-W host:port]\n" 210 " [-w local_tun[:remote_tun]] [user@]hostname [command]\n" 211 ); 212 exit(255); 213 } 214 215 static int ssh_session(void); 216 static int ssh_session2(void); 217 static void load_public_identity_files(void); 218 static void main_sigchld_handler(int); 219 220 /* from muxclient.c */ 221 void muxclient(const char *); 222 void muxserver_listen(void); 223 224 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 225 static void 226 tilde_expand_paths(char **paths, u_int num_paths) 227 { 228 u_int i; 229 char *cp; 230 231 for (i = 0; i < num_paths; i++) { 232 cp = tilde_expand_filename(paths[i], original_real_uid); 233 free(paths[i]); 234 paths[i] = cp; 235 } 236 } 237 238 /* 239 * Attempt to resolve a host name / port to a set of addresses and 240 * optionally return any CNAMEs encountered along the way. 241 * Returns NULL on failure. 242 * NB. this function must operate with a options having undefined members. 243 */ 244 static struct addrinfo * 245 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen) 246 { 247 char strport[NI_MAXSERV]; 248 struct addrinfo hints, *res; 249 int gaierr, loglevel = SYSLOG_LEVEL_DEBUG1; 250 251 if (port <= 0) 252 port = default_ssh_port(); 253 254 snprintf(strport, sizeof strport, "%u", port); 255 memset(&hints, 0, sizeof(hints)); 256 hints.ai_family = options.address_family == -1 ? 257 AF_UNSPEC : options.address_family; 258 hints.ai_socktype = SOCK_STREAM; 259 if (cname != NULL) 260 hints.ai_flags = AI_CANONNAME; 261 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 262 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) 263 loglevel = SYSLOG_LEVEL_ERROR; 264 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", 265 __progname, name, ssh_gai_strerror(gaierr)); 266 return NULL; 267 } 268 if (cname != NULL && res->ai_canonname != NULL) { 269 if (strlcpy(cname, res->ai_canonname, clen) >= clen) { 270 error("%s: host \"%s\" cname \"%s\" too long (max %lu)", 271 __func__, name, res->ai_canonname, (u_long)clen); 272 if (clen > 0) 273 *cname = '\0'; 274 } 275 } 276 return res; 277 } 278 279 /* 280 * Attempt to resolve a numeric host address / port to a single address. 281 * Returns a canonical address string. 282 * Returns NULL on failure. 283 * NB. this function must operate with a options having undefined members. 284 */ 285 static struct addrinfo * 286 resolve_addr(const char *name, int port, char *caddr, size_t clen) 287 { 288 char addr[NI_MAXHOST], strport[NI_MAXSERV]; 289 struct addrinfo hints, *res; 290 int gaierr; 291 292 if (port <= 0) 293 port = default_ssh_port(); 294 snprintf(strport, sizeof strport, "%u", port); 295 memset(&hints, 0, sizeof(hints)); 296 hints.ai_family = options.address_family == -1 ? 297 AF_UNSPEC : options.address_family; 298 hints.ai_socktype = SOCK_STREAM; 299 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 300 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 301 debug2("%s: could not resolve name %.100s as address: %s", 302 __func__, name, ssh_gai_strerror(gaierr)); 303 return NULL; 304 } 305 if (res == NULL) { 306 debug("%s: getaddrinfo %.100s returned no addresses", 307 __func__, name); 308 return NULL; 309 } 310 if (res->ai_next != NULL) { 311 debug("%s: getaddrinfo %.100s returned multiple addresses", 312 __func__, name); 313 goto fail; 314 } 315 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen, 316 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) { 317 debug("%s: Could not format address for name %.100s: %s", 318 __func__, name, ssh_gai_strerror(gaierr)); 319 goto fail; 320 } 321 if (strlcpy(caddr, addr, clen) >= clen) { 322 error("%s: host \"%s\" addr \"%s\" too long (max %lu)", 323 __func__, name, addr, (u_long)clen); 324 if (clen > 0) 325 *caddr = '\0'; 326 fail: 327 freeaddrinfo(res); 328 return NULL; 329 } 330 return res; 331 } 332 333 /* 334 * Check whether the cname is a permitted replacement for the hostname 335 * and perform the replacement if it is. 336 * NB. this function must operate with a options having undefined members. 337 */ 338 static int 339 check_follow_cname(char **namep, const char *cname) 340 { 341 int i; 342 struct allowed_cname *rule; 343 344 if (*cname == '\0' || options.num_permitted_cnames == 0 || 345 strcmp(*namep, cname) == 0) 346 return 0; 347 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 348 return 0; 349 /* 350 * Don't attempt to canonicalize names that will be interpreted by 351 * a proxy unless the user specifically requests so. 352 */ 353 if (!option_clear_or_none(options.proxy_command) && 354 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 355 return 0; 356 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname); 357 for (i = 0; i < options.num_permitted_cnames; i++) { 358 rule = options.permitted_cnames + i; 359 if (match_pattern_list(*namep, rule->source_list, 360 strlen(rule->source_list), 1) != 1 || 361 match_pattern_list(cname, rule->target_list, 362 strlen(rule->target_list), 1) != 1) 363 continue; 364 verbose("Canonicalized DNS aliased hostname " 365 "\"%s\" => \"%s\"", *namep, cname); 366 free(*namep); 367 *namep = xstrdup(cname); 368 return 1; 369 } 370 return 0; 371 } 372 373 /* 374 * Attempt to resolve the supplied hostname after applying the user's 375 * canonicalization rules. Returns the address list for the host or NULL 376 * if no name was found after canonicalization. 377 * NB. this function must operate with a options having undefined members. 378 */ 379 static struct addrinfo * 380 resolve_canonicalize(char **hostp, int port) 381 { 382 int i, ndots; 383 char *cp, *fullhost, newname[NI_MAXHOST]; 384 struct addrinfo *addrs; 385 386 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 387 return NULL; 388 389 /* 390 * Don't attempt to canonicalize names that will be interpreted by 391 * a proxy unless the user specifically requests so. 392 */ 393 if (!option_clear_or_none(options.proxy_command) && 394 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 395 return NULL; 396 397 /* Try numeric hostnames first */ 398 if ((addrs = resolve_addr(*hostp, port, 399 newname, sizeof(newname))) != NULL) { 400 debug2("%s: hostname %.100s is address", __func__, *hostp); 401 if (strcasecmp(*hostp, newname) != 0) { 402 debug2("%s: canonicalised address \"%s\" => \"%s\"", 403 __func__, *hostp, newname); 404 free(*hostp); 405 *hostp = xstrdup(newname); 406 } 407 return addrs; 408 } 409 410 /* Don't apply canonicalization to sufficiently-qualified hostnames */ 411 ndots = 0; 412 for (cp = *hostp; *cp != '\0'; cp++) { 413 if (*cp == '.') 414 ndots++; 415 } 416 if (ndots > options.canonicalize_max_dots) { 417 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)", 418 __func__, *hostp, options.canonicalize_max_dots); 419 return NULL; 420 } 421 /* Attempt each supplied suffix */ 422 for (i = 0; i < options.num_canonical_domains; i++) { 423 *newname = '\0'; 424 xasprintf(&fullhost, "%s.%s.", *hostp, 425 options.canonical_domains[i]); 426 debug3("%s: attempting \"%s\" => \"%s\"", __func__, 427 *hostp, fullhost); 428 if ((addrs = resolve_host(fullhost, port, 0, 429 newname, sizeof(newname))) == NULL) { 430 free(fullhost); 431 continue; 432 } 433 /* Remove trailing '.' */ 434 fullhost[strlen(fullhost) - 1] = '\0'; 435 /* Follow CNAME if requested */ 436 if (!check_follow_cname(&fullhost, newname)) { 437 debug("Canonicalized hostname \"%s\" => \"%s\"", 438 *hostp, fullhost); 439 } 440 free(*hostp); 441 *hostp = fullhost; 442 return addrs; 443 } 444 if (!options.canonicalize_fallback_local) 445 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); 446 debug2("%s: host %s not found in any suffix", __func__, *hostp); 447 return NULL; 448 } 449 450 /* 451 * Read per-user configuration file. Ignore the system wide config 452 * file if the user specifies a config file on the command line. 453 */ 454 static void 455 process_config_files(const char *host_arg, struct passwd *pw, int post_canon) 456 { 457 char buf[PATH_MAX]; 458 int r; 459 460 if (config != NULL) { 461 if (strcasecmp(config, "none") != 0 && 462 !read_config_file(config, pw, host, host_arg, &options, 463 SSHCONF_USERCONF | (post_canon ? SSHCONF_POSTCANON : 0))) 464 fatal("Can't open user config file %.100s: " 465 "%.100s", config, strerror(errno)); 466 } else { 467 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 468 _PATH_SSH_USER_CONFFILE); 469 if (r > 0 && (size_t)r < sizeof(buf)) 470 (void)read_config_file(buf, pw, host, host_arg, 471 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF | 472 (post_canon ? SSHCONF_POSTCANON : 0)); 473 474 /* Read systemwide configuration file after user config. */ 475 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, 476 host, host_arg, &options, 477 post_canon ? SSHCONF_POSTCANON : 0); 478 } 479 } 480 481 /* Rewrite the port number in an addrinfo list of addresses */ 482 static void 483 set_addrinfo_port(struct addrinfo *addrs, int port) 484 { 485 struct addrinfo *addr; 486 487 for (addr = addrs; addr != NULL; addr = addr->ai_next) { 488 switch (addr->ai_family) { 489 case AF_INET: 490 ((struct sockaddr_in *)addr->ai_addr)-> 491 sin_port = htons(port); 492 break; 493 case AF_INET6: 494 ((struct sockaddr_in6 *)addr->ai_addr)-> 495 sin6_port = htons(port); 496 break; 497 } 498 } 499 } 500 501 /* 502 * Main program for the ssh client. 503 */ 504 int 505 main(int ac, char **av) 506 { 507 int i, r, opt, exit_status, use_syslog, config_test = 0; 508 char *p, *cp, *line, *argv0, buf[PATH_MAX], *host_arg, *logfile; 509 char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 510 char cname[NI_MAXHOST]; 511 struct stat st; 512 struct passwd *pw; 513 int timeout_ms; 514 extern int optind, optreset; 515 extern char *optarg; 516 struct Forward fwd; 517 struct addrinfo *addrs = NULL; 518 struct ssh_digest_ctx *md; 519 u_char conn_hash[SSH_DIGEST_MAX_LENGTH]; 520 char *conn_hash_hex; 521 522 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 523 sanitise_stdfd(); 524 525 __progname = ssh_get_progname(av[0]); 526 527 #ifndef HAVE_SETPROCTITLE 528 /* Prepare for later setproctitle emulation */ 529 /* Save argv so it isn't clobbered by setproctitle() emulation */ 530 saved_av = xcalloc(ac + 1, sizeof(*saved_av)); 531 for (i = 0; i < ac; i++) 532 saved_av[i] = xstrdup(av[i]); 533 saved_av[i] = NULL; 534 compat_init_setproctitle(ac, av); 535 av = saved_av; 536 #endif 537 538 /* 539 * Discard other fds that are hanging around. These can cause problem 540 * with backgrounded ssh processes started by ControlPersist. 541 */ 542 closefrom(STDERR_FILENO + 1); 543 544 /* 545 * Save the original real uid. It will be needed later (uid-swapping 546 * may clobber the real uid). 547 */ 548 original_real_uid = getuid(); 549 original_effective_uid = geteuid(); 550 551 /* 552 * Use uid-swapping to give up root privileges for the duration of 553 * option processing. We will re-instantiate the rights when we are 554 * ready to create the privileged port, and will permanently drop 555 * them when the port has been created (actually, when the connection 556 * has been made, as we may need to create the port several times). 557 */ 558 PRIV_END; 559 560 #ifdef HAVE_SETRLIMIT 561 /* If we are installed setuid root be careful to not drop core. */ 562 if (original_real_uid != original_effective_uid) { 563 struct rlimit rlim; 564 rlim.rlim_cur = rlim.rlim_max = 0; 565 if (setrlimit(RLIMIT_CORE, &rlim) < 0) 566 fatal("setrlimit failed: %.100s", strerror(errno)); 567 } 568 #endif 569 /* Get user data. */ 570 pw = getpwuid(original_real_uid); 571 if (!pw) { 572 logit("No user exists for uid %lu", (u_long)original_real_uid); 573 exit(255); 574 } 575 /* Take a copy of the returned structure. */ 576 pw = pwcopy(pw); 577 578 /* 579 * Set our umask to something reasonable, as some files are created 580 * with the default umask. This will make them world-readable but 581 * writable only by the owner, which is ok for all files for which we 582 * don't set the modes explicitly. 583 */ 584 umask(022); 585 586 /* 587 * Initialize option structure to indicate that no values have been 588 * set. 589 */ 590 initialize_options(&options); 591 592 /* Parse command-line arguments. */ 593 host = NULL; 594 use_syslog = 0; 595 logfile = NULL; 596 argv0 = av[0]; 597 598 again: 599 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 600 "ACD:E:F:GI:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { 601 switch (opt) { 602 case '1': 603 options.protocol = SSH_PROTO_1; 604 break; 605 case '2': 606 options.protocol = SSH_PROTO_2; 607 break; 608 case '4': 609 options.address_family = AF_INET; 610 break; 611 case '6': 612 options.address_family = AF_INET6; 613 break; 614 case 'n': 615 stdin_null_flag = 1; 616 break; 617 case 'f': 618 fork_after_authentication_flag = 1; 619 stdin_null_flag = 1; 620 break; 621 case 'x': 622 options.forward_x11 = 0; 623 break; 624 case 'X': 625 options.forward_x11 = 1; 626 break; 627 case 'y': 628 use_syslog = 1; 629 break; 630 case 'E': 631 logfile = xstrdup(optarg); 632 break; 633 case 'G': 634 config_test = 1; 635 break; 636 case 'Y': 637 options.forward_x11 = 1; 638 options.forward_x11_trusted = 1; 639 break; 640 case 'g': 641 options.fwd_opts.gateway_ports = 1; 642 break; 643 case 'O': 644 if (stdio_forward_host != NULL) 645 fatal("Cannot specify multiplexing " 646 "command with -W"); 647 else if (muxclient_command != 0) 648 fatal("Multiplexing command already specified"); 649 if (strcmp(optarg, "check") == 0) 650 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 651 else if (strcmp(optarg, "forward") == 0) 652 muxclient_command = SSHMUX_COMMAND_FORWARD; 653 else if (strcmp(optarg, "exit") == 0) 654 muxclient_command = SSHMUX_COMMAND_TERMINATE; 655 else if (strcmp(optarg, "stop") == 0) 656 muxclient_command = SSHMUX_COMMAND_STOP; 657 else if (strcmp(optarg, "cancel") == 0) 658 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 659 else 660 fatal("Invalid multiplex command."); 661 break; 662 case 'P': /* deprecated */ 663 options.use_privileged_port = 0; 664 break; 665 case 'Q': 666 cp = NULL; 667 if (strcmp(optarg, "cipher") == 0) 668 cp = cipher_alg_list('\n', 0); 669 else if (strcmp(optarg, "cipher-auth") == 0) 670 cp = cipher_alg_list('\n', 1); 671 else if (strcmp(optarg, "mac") == 0) 672 cp = mac_alg_list('\n'); 673 else if (strcmp(optarg, "kex") == 0) 674 cp = kex_alg_list('\n'); 675 else if (strcmp(optarg, "key") == 0) 676 cp = key_alg_list(0, 0); 677 else if (strcmp(optarg, "key-cert") == 0) 678 cp = key_alg_list(1, 0); 679 else if (strcmp(optarg, "key-plain") == 0) 680 cp = key_alg_list(0, 1); 681 else if (strcmp(optarg, "protocol-version") == 0) { 682 #ifdef WITH_SSH1 683 cp = xstrdup("1\n2"); 684 #else 685 cp = xstrdup("2"); 686 #endif 687 } 688 if (cp == NULL) 689 fatal("Unsupported query \"%s\"", optarg); 690 printf("%s\n", cp); 691 free(cp); 692 exit(0); 693 break; 694 case 'a': 695 options.forward_agent = 0; 696 break; 697 case 'A': 698 options.forward_agent = 1; 699 break; 700 case 'k': 701 options.gss_deleg_creds = 0; 702 break; 703 case 'K': 704 options.gss_authentication = 1; 705 options.gss_deleg_creds = 1; 706 break; 707 case 'i': 708 if (stat(optarg, &st) < 0) { 709 fprintf(stderr, "Warning: Identity file %s " 710 "not accessible: %s.\n", optarg, 711 strerror(errno)); 712 break; 713 } 714 add_identity_file(&options, NULL, optarg, 1); 715 break; 716 case 'I': 717 #ifdef ENABLE_PKCS11 718 options.pkcs11_provider = xstrdup(optarg); 719 #else 720 fprintf(stderr, "no support for PKCS#11.\n"); 721 #endif 722 break; 723 case 't': 724 if (options.request_tty == REQUEST_TTY_YES) 725 options.request_tty = REQUEST_TTY_FORCE; 726 else 727 options.request_tty = REQUEST_TTY_YES; 728 break; 729 case 'v': 730 if (debug_flag == 0) { 731 debug_flag = 1; 732 options.log_level = SYSLOG_LEVEL_DEBUG1; 733 } else { 734 if (options.log_level < SYSLOG_LEVEL_DEBUG3) 735 options.log_level++; 736 } 737 break; 738 case 'V': 739 fprintf(stderr, "%s, %s\n", 740 SSH_RELEASE, 741 #ifdef WITH_OPENSSL 742 SSLeay_version(SSLEAY_VERSION) 743 #else 744 "without OpenSSL" 745 #endif 746 ); 747 if (opt == 'V') 748 exit(0); 749 break; 750 case 'w': 751 if (options.tun_open == -1) 752 options.tun_open = SSH_TUNMODE_DEFAULT; 753 options.tun_local = a2tun(optarg, &options.tun_remote); 754 if (options.tun_local == SSH_TUNID_ERR) { 755 fprintf(stderr, 756 "Bad tun device '%s'\n", optarg); 757 exit(255); 758 } 759 break; 760 case 'W': 761 if (stdio_forward_host != NULL) 762 fatal("stdio forward already specified"); 763 if (muxclient_command != 0) 764 fatal("Cannot specify stdio forward with -O"); 765 if (parse_forward(&fwd, optarg, 1, 0)) { 766 stdio_forward_host = fwd.listen_host; 767 stdio_forward_port = fwd.listen_port; 768 free(fwd.connect_host); 769 } else { 770 fprintf(stderr, 771 "Bad stdio forwarding specification '%s'\n", 772 optarg); 773 exit(255); 774 } 775 options.request_tty = REQUEST_TTY_NO; 776 no_shell_flag = 1; 777 options.clear_forwardings = 1; 778 options.exit_on_forward_failure = 1; 779 break; 780 case 'q': 781 options.log_level = SYSLOG_LEVEL_QUIET; 782 break; 783 case 'e': 784 if (optarg[0] == '^' && optarg[2] == 0 && 785 (u_char) optarg[1] >= 64 && 786 (u_char) optarg[1] < 128) 787 options.escape_char = (u_char) optarg[1] & 31; 788 else if (strlen(optarg) == 1) 789 options.escape_char = (u_char) optarg[0]; 790 else if (strcmp(optarg, "none") == 0) 791 options.escape_char = SSH_ESCAPECHAR_NONE; 792 else { 793 fprintf(stderr, "Bad escape character '%s'.\n", 794 optarg); 795 exit(255); 796 } 797 break; 798 case 'c': 799 if (ciphers_valid(optarg)) { 800 /* SSH2 only */ 801 options.ciphers = xstrdup(optarg); 802 options.cipher = SSH_CIPHER_INVALID; 803 } else { 804 /* SSH1 only */ 805 options.cipher = cipher_number(optarg); 806 if (options.cipher == -1) { 807 fprintf(stderr, 808 "Unknown cipher type '%s'\n", 809 optarg); 810 exit(255); 811 } 812 if (options.cipher == SSH_CIPHER_3DES) 813 options.ciphers = "3des-cbc"; 814 else if (options.cipher == SSH_CIPHER_BLOWFISH) 815 options.ciphers = "blowfish-cbc"; 816 else 817 options.ciphers = (char *)-1; 818 } 819 break; 820 case 'm': 821 if (mac_valid(optarg)) 822 options.macs = xstrdup(optarg); 823 else { 824 fprintf(stderr, "Unknown mac type '%s'\n", 825 optarg); 826 exit(255); 827 } 828 break; 829 case 'M': 830 if (options.control_master == SSHCTL_MASTER_YES) 831 options.control_master = SSHCTL_MASTER_ASK; 832 else 833 options.control_master = SSHCTL_MASTER_YES; 834 break; 835 case 'p': 836 options.port = a2port(optarg); 837 if (options.port <= 0) { 838 fprintf(stderr, "Bad port '%s'\n", optarg); 839 exit(255); 840 } 841 break; 842 case 'l': 843 options.user = optarg; 844 break; 845 846 case 'L': 847 if (parse_forward(&fwd, optarg, 0, 0)) 848 add_local_forward(&options, &fwd); 849 else { 850 fprintf(stderr, 851 "Bad local forwarding specification '%s'\n", 852 optarg); 853 exit(255); 854 } 855 break; 856 857 case 'R': 858 if (parse_forward(&fwd, optarg, 0, 1)) { 859 add_remote_forward(&options, &fwd); 860 } else { 861 fprintf(stderr, 862 "Bad remote forwarding specification " 863 "'%s'\n", optarg); 864 exit(255); 865 } 866 break; 867 868 case 'D': 869 if (parse_forward(&fwd, optarg, 1, 0)) { 870 add_local_forward(&options, &fwd); 871 } else { 872 fprintf(stderr, 873 "Bad dynamic forwarding specification " 874 "'%s'\n", optarg); 875 exit(255); 876 } 877 break; 878 879 case 'C': 880 options.compression = 1; 881 break; 882 case 'N': 883 no_shell_flag = 1; 884 options.request_tty = REQUEST_TTY_NO; 885 break; 886 case 'T': 887 options.request_tty = REQUEST_TTY_NO; 888 break; 889 case 'o': 890 line = xstrdup(optarg); 891 if (process_config_line(&options, pw, 892 host ? host : "", host ? host : "", line, 893 "command-line", 0, NULL, SSHCONF_USERCONF) != 0) 894 exit(255); 895 free(line); 896 break; 897 case 's': 898 subsystem_flag = 1; 899 break; 900 case 'S': 901 if (options.control_path != NULL) 902 free(options.control_path); 903 options.control_path = xstrdup(optarg); 904 break; 905 case 'b': 906 options.bind_address = optarg; 907 break; 908 case 'F': 909 config = optarg; 910 break; 911 default: 912 usage(); 913 } 914 } 915 916 ac -= optind; 917 av += optind; 918 919 if (ac > 0 && !host) { 920 if (strrchr(*av, '@')) { 921 p = xstrdup(*av); 922 cp = strrchr(p, '@'); 923 if (cp == NULL || cp == p) 924 usage(); 925 options.user = p; 926 *cp = '\0'; 927 host = xstrdup(++cp); 928 } else 929 host = xstrdup(*av); 930 if (ac > 1) { 931 optind = optreset = 1; 932 goto again; 933 } 934 ac--, av++; 935 } 936 937 /* Check that we got a host name. */ 938 if (!host) 939 usage(); 940 941 host_arg = xstrdup(host); 942 943 #ifdef WITH_OPENSSL 944 OpenSSL_add_all_algorithms(); 945 ERR_load_crypto_strings(); 946 #endif 947 948 /* Initialize the command to execute on remote host. */ 949 buffer_init(&command); 950 951 /* 952 * Save the command to execute on the remote host in a buffer. There 953 * is no limit on the length of the command, except by the maximum 954 * packet size. Also sets the tty flag if there is no command. 955 */ 956 if (!ac) { 957 /* No command specified - execute shell on a tty. */ 958 if (subsystem_flag) { 959 fprintf(stderr, 960 "You must specify a subsystem to invoke.\n"); 961 usage(); 962 } 963 } else { 964 /* A command has been specified. Store it into the buffer. */ 965 for (i = 0; i < ac; i++) { 966 if (i) 967 buffer_append(&command, " ", 1); 968 buffer_append(&command, av[i], strlen(av[i])); 969 } 970 } 971 972 /* Cannot fork to background if no command. */ 973 if (fork_after_authentication_flag && buffer_len(&command) == 0 && 974 !no_shell_flag) 975 fatal("Cannot fork into background without a command " 976 "to execute."); 977 978 /* 979 * Initialize "log" output. Since we are the client all output 980 * goes to stderr unless otherwise specified by -y or -E. 981 */ 982 if (use_syslog && logfile != NULL) 983 fatal("Can't specify both -y and -E"); 984 if (logfile != NULL) { 985 log_redirect_stderr_to(logfile); 986 free(logfile); 987 } 988 log_init(argv0, 989 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, 990 SYSLOG_FACILITY_USER, !use_syslog); 991 992 if (debug_flag) 993 logit("%s, %s", SSH_RELEASE, 994 #ifdef WITH_OPENSSL 995 SSLeay_version(SSLEAY_VERSION) 996 #else 997 "without OpenSSL" 998 #endif 999 ); 1000 1001 /* Parse the configuration files */ 1002 process_config_files(host_arg, pw, 0); 1003 1004 /* Hostname canonicalisation needs a few options filled. */ 1005 fill_default_options_for_canonicalization(&options); 1006 1007 /* If the user has replaced the hostname then take it into use now */ 1008 if (options.hostname != NULL) { 1009 /* NB. Please keep in sync with readconf.c:match_cfg_line() */ 1010 cp = percent_expand(options.hostname, 1011 "h", host, (char *)NULL); 1012 free(host); 1013 host = cp; 1014 free(options.hostname); 1015 options.hostname = xstrdup(host); 1016 } 1017 1018 /* If canonicalization requested then try to apply it */ 1019 lowercase(host); 1020 if (options.canonicalize_hostname != SSH_CANONICALISE_NO) 1021 addrs = resolve_canonicalize(&host, options.port); 1022 1023 /* 1024 * If CanonicalizePermittedCNAMEs have been specified but 1025 * other canonicalization did not happen (by not being requested 1026 * or by failing with fallback) then the hostname may still be changed 1027 * as a result of CNAME following. 1028 * 1029 * Try to resolve the bare hostname name using the system resolver's 1030 * usual search rules and then apply the CNAME follow rules. 1031 * 1032 * Skip the lookup if a ProxyCommand is being used unless the user 1033 * has specifically requested canonicalisation for this case via 1034 * CanonicalizeHostname=always 1035 */ 1036 if (addrs == NULL && options.num_permitted_cnames != 0 && 1037 (option_clear_or_none(options.proxy_command) || 1038 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { 1039 if ((addrs = resolve_host(host, options.port, 1040 option_clear_or_none(options.proxy_command), 1041 cname, sizeof(cname))) == NULL) { 1042 /* Don't fatal proxied host names not in the DNS */ 1043 if (option_clear_or_none(options.proxy_command)) 1044 cleanup_exit(255); /* logged in resolve_host */ 1045 } else 1046 check_follow_cname(&host, cname); 1047 } 1048 1049 /* 1050 * If canonicalisation is enabled then re-parse the configuration 1051 * files as new stanzas may match. 1052 */ 1053 if (options.canonicalize_hostname != 0) { 1054 debug("Re-reading configuration after hostname " 1055 "canonicalisation"); 1056 free(options.hostname); 1057 options.hostname = xstrdup(host); 1058 process_config_files(host_arg, pw, 1); 1059 /* 1060 * Address resolution happens early with canonicalisation 1061 * enabled and the port number may have changed since, so 1062 * reset it in address list 1063 */ 1064 if (addrs != NULL && options.port > 0) 1065 set_addrinfo_port(addrs, options.port); 1066 } 1067 1068 /* Fill configuration defaults. */ 1069 fill_default_options(&options); 1070 1071 if (options.port == 0) 1072 options.port = default_ssh_port(); 1073 channel_set_af(options.address_family); 1074 1075 /* Tidy and check options */ 1076 if (options.host_key_alias != NULL) 1077 lowercase(options.host_key_alias); 1078 if (options.proxy_command != NULL && 1079 strcmp(options.proxy_command, "-") == 0 && 1080 options.proxy_use_fdpass) 1081 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); 1082 if (options.control_persist && 1083 options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 1084 debug("UpdateHostKeys=ask is incompatible with ControlPersist; " 1085 "disabling"); 1086 options.update_hostkeys = 0; 1087 } 1088 #ifndef HAVE_CYGWIN 1089 if (original_effective_uid != 0) 1090 options.use_privileged_port = 0; 1091 #endif 1092 1093 /* reinit */ 1094 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog); 1095 1096 if (options.request_tty == REQUEST_TTY_YES || 1097 options.request_tty == REQUEST_TTY_FORCE) 1098 tty_flag = 1; 1099 1100 /* Allocate a tty by default if no command specified. */ 1101 if (buffer_len(&command) == 0) 1102 tty_flag = options.request_tty != REQUEST_TTY_NO; 1103 1104 /* Force no tty */ 1105 if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0) 1106 tty_flag = 0; 1107 /* Do not allocate a tty if stdin is not a tty. */ 1108 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 1109 options.request_tty != REQUEST_TTY_FORCE) { 1110 if (tty_flag) 1111 logit("Pseudo-terminal will not be allocated because " 1112 "stdin is not a terminal."); 1113 tty_flag = 0; 1114 } 1115 1116 seed_rng(); 1117 1118 if (options.user == NULL) 1119 options.user = xstrdup(pw->pw_name); 1120 1121 if (gethostname(thishost, sizeof(thishost)) == -1) 1122 fatal("gethostname: %s", strerror(errno)); 1123 strlcpy(shorthost, thishost, sizeof(shorthost)); 1124 shorthost[strcspn(thishost, ".")] = '\0'; 1125 snprintf(portstr, sizeof(portstr), "%d", options.port); 1126 1127 if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL || 1128 ssh_digest_update(md, thishost, strlen(thishost)) < 0 || 1129 ssh_digest_update(md, host, strlen(host)) < 0 || 1130 ssh_digest_update(md, portstr, strlen(portstr)) < 0 || 1131 ssh_digest_update(md, options.user, strlen(options.user)) < 0 || 1132 ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0) 1133 fatal("%s: mux digest failed", __func__); 1134 ssh_digest_free(md); 1135 conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1)); 1136 1137 if (options.local_command != NULL) { 1138 debug3("expanding LocalCommand: %s", options.local_command); 1139 cp = options.local_command; 1140 options.local_command = percent_expand(cp, 1141 "C", conn_hash_hex, 1142 "L", shorthost, 1143 "d", pw->pw_dir, 1144 "h", host, 1145 "l", thishost, 1146 "n", host_arg, 1147 "p", portstr, 1148 "r", options.user, 1149 "u", pw->pw_name, 1150 (char *)NULL); 1151 debug3("expanded LocalCommand: %s", options.local_command); 1152 free(cp); 1153 } 1154 1155 if (options.control_path != NULL) { 1156 cp = tilde_expand_filename(options.control_path, 1157 original_real_uid); 1158 free(options.control_path); 1159 options.control_path = percent_expand(cp, 1160 "C", conn_hash_hex, 1161 "L", shorthost, 1162 "h", host, 1163 "l", thishost, 1164 "n", host_arg, 1165 "p", portstr, 1166 "r", options.user, 1167 "u", pw->pw_name, 1168 (char *)NULL); 1169 free(cp); 1170 } 1171 free(conn_hash_hex); 1172 1173 if (config_test) { 1174 dump_client_config(&options, host); 1175 exit(0); 1176 } 1177 1178 if (muxclient_command != 0 && options.control_path == NULL) 1179 fatal("No ControlPath specified for \"-O\" command"); 1180 if (options.control_path != NULL) 1181 muxclient(options.control_path); 1182 1183 /* 1184 * If hostname canonicalisation was not enabled, then we may not 1185 * have yet resolved the hostname. Do so now. 1186 */ 1187 if (addrs == NULL && options.proxy_command == NULL) { 1188 if ((addrs = resolve_host(host, options.port, 1, 1189 cname, sizeof(cname))) == NULL) 1190 cleanup_exit(255); /* resolve_host logs the error */ 1191 } 1192 1193 timeout_ms = options.connection_timeout * 1000; 1194 1195 /* Open a connection to the remote host. */ 1196 if (ssh_connect(host, addrs, &hostaddr, options.port, 1197 options.address_family, options.connection_attempts, 1198 &timeout_ms, options.tcp_keep_alive, 1199 options.use_privileged_port) != 0) 1200 exit(255); 1201 1202 if (addrs != NULL) 1203 freeaddrinfo(addrs); 1204 1205 packet_set_timeout(options.server_alive_interval, 1206 options.server_alive_count_max); 1207 1208 if (timeout_ms > 0) 1209 debug3("timeout: %d ms remain after connect", timeout_ms); 1210 1211 /* 1212 * If we successfully made the connection, load the host private key 1213 * in case we will need it later for combined rsa-rhosts 1214 * authentication. This must be done before releasing extra 1215 * privileges, because the file is only readable by root. 1216 * If we cannot access the private keys, load the public keys 1217 * instead and try to execute the ssh-keysign helper instead. 1218 */ 1219 sensitive_data.nkeys = 0; 1220 sensitive_data.keys = NULL; 1221 sensitive_data.external_keysign = 0; 1222 if (options.rhosts_rsa_authentication || 1223 options.hostbased_authentication) { 1224 sensitive_data.nkeys = 9; 1225 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 1226 sizeof(Key)); 1227 for (i = 0; i < sensitive_data.nkeys; i++) 1228 sensitive_data.keys[i] = NULL; 1229 1230 PRIV_START; 1231 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, 1232 _PATH_HOST_KEY_FILE, "", NULL, NULL); 1233 #ifdef OPENSSL_HAS_ECC 1234 sensitive_data.keys[1] = key_load_private_cert(KEY_ECDSA, 1235 _PATH_HOST_ECDSA_KEY_FILE, "", NULL); 1236 #endif 1237 sensitive_data.keys[2] = key_load_private_cert(KEY_ED25519, 1238 _PATH_HOST_ED25519_KEY_FILE, "", NULL); 1239 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA, 1240 _PATH_HOST_RSA_KEY_FILE, "", NULL); 1241 sensitive_data.keys[4] = key_load_private_cert(KEY_DSA, 1242 _PATH_HOST_DSA_KEY_FILE, "", NULL); 1243 #ifdef OPENSSL_HAS_ECC 1244 sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA, 1245 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL); 1246 #endif 1247 sensitive_data.keys[6] = key_load_private_type(KEY_ED25519, 1248 _PATH_HOST_ED25519_KEY_FILE, "", NULL, NULL); 1249 sensitive_data.keys[7] = key_load_private_type(KEY_RSA, 1250 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); 1251 sensitive_data.keys[8] = key_load_private_type(KEY_DSA, 1252 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); 1253 PRIV_END; 1254 1255 if (options.hostbased_authentication == 1 && 1256 sensitive_data.keys[0] == NULL && 1257 sensitive_data.keys[5] == NULL && 1258 sensitive_data.keys[6] == NULL && 1259 sensitive_data.keys[7] == NULL && 1260 sensitive_data.keys[8] == NULL) { 1261 #ifdef OPENSSL_HAS_ECC 1262 sensitive_data.keys[1] = key_load_cert( 1263 _PATH_HOST_ECDSA_KEY_FILE); 1264 #endif 1265 sensitive_data.keys[2] = key_load_cert( 1266 _PATH_HOST_ED25519_KEY_FILE); 1267 sensitive_data.keys[3] = key_load_cert( 1268 _PATH_HOST_RSA_KEY_FILE); 1269 sensitive_data.keys[4] = key_load_cert( 1270 _PATH_HOST_DSA_KEY_FILE); 1271 #ifdef OPENSSL_HAS_ECC 1272 sensitive_data.keys[5] = key_load_public( 1273 _PATH_HOST_ECDSA_KEY_FILE, NULL); 1274 #endif 1275 sensitive_data.keys[6] = key_load_public( 1276 _PATH_HOST_ED25519_KEY_FILE, NULL); 1277 sensitive_data.keys[7] = key_load_public( 1278 _PATH_HOST_RSA_KEY_FILE, NULL); 1279 sensitive_data.keys[8] = key_load_public( 1280 _PATH_HOST_DSA_KEY_FILE, NULL); 1281 sensitive_data.external_keysign = 1; 1282 } 1283 } 1284 /* 1285 * Get rid of any extra privileges that we may have. We will no 1286 * longer need them. Also, extra privileges could make it very hard 1287 * to read identity files and other non-world-readable files from the 1288 * user's home directory if it happens to be on a NFS volume where 1289 * root is mapped to nobody. 1290 */ 1291 if (original_effective_uid == 0) { 1292 PRIV_START; 1293 permanently_set_uid(pw); 1294 } 1295 1296 /* 1297 * Now that we are back to our own permissions, create ~/.ssh 1298 * directory if it doesn't already exist. 1299 */ 1300 if (config == NULL) { 1301 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 1302 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 1303 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) { 1304 #ifdef WITH_SELINUX 1305 ssh_selinux_setfscreatecon(buf); 1306 #endif 1307 if (mkdir(buf, 0700) < 0) 1308 error("Could not create directory '%.200s'.", 1309 buf); 1310 #ifdef WITH_SELINUX 1311 ssh_selinux_setfscreatecon(NULL); 1312 #endif 1313 } 1314 } 1315 /* load options.identity_files */ 1316 load_public_identity_files(); 1317 1318 /* Expand ~ in known host file names. */ 1319 tilde_expand_paths(options.system_hostfiles, 1320 options.num_system_hostfiles); 1321 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 1322 1323 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 1324 signal(SIGCHLD, main_sigchld_handler); 1325 1326 /* Log into the remote system. Never returns if the login fails. */ 1327 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, 1328 options.port, pw, timeout_ms); 1329 1330 if (packet_connection_is_on_socket()) { 1331 verbose("Authenticated to %s ([%s]:%d).", host, 1332 get_remote_ipaddr(), get_remote_port()); 1333 } else { 1334 verbose("Authenticated to %s (via proxy).", host); 1335 } 1336 1337 /* We no longer need the private host keys. Clear them now. */ 1338 if (sensitive_data.nkeys != 0) { 1339 for (i = 0; i < sensitive_data.nkeys; i++) { 1340 if (sensitive_data.keys[i] != NULL) { 1341 /* Destroys contents safely */ 1342 debug3("clear hostkey %d", i); 1343 key_free(sensitive_data.keys[i]); 1344 sensitive_data.keys[i] = NULL; 1345 } 1346 } 1347 free(sensitive_data.keys); 1348 } 1349 for (i = 0; i < options.num_identity_files; i++) { 1350 free(options.identity_files[i]); 1351 options.identity_files[i] = NULL; 1352 if (options.identity_keys[i]) { 1353 key_free(options.identity_keys[i]); 1354 options.identity_keys[i] = NULL; 1355 } 1356 } 1357 1358 exit_status = compat20 ? ssh_session2() : ssh_session(); 1359 packet_close(); 1360 1361 if (options.control_path != NULL && muxserver_sock != -1) 1362 unlink(options.control_path); 1363 1364 /* Kill ProxyCommand if it is running. */ 1365 ssh_kill_proxy_command(); 1366 1367 return exit_status; 1368 } 1369 1370 static void 1371 control_persist_detach(void) 1372 { 1373 pid_t pid; 1374 int devnull; 1375 1376 debug("%s: backgrounding master process", __func__); 1377 1378 /* 1379 * master (current process) into the background, and make the 1380 * foreground process a client of the backgrounded master. 1381 */ 1382 switch ((pid = fork())) { 1383 case -1: 1384 fatal("%s: fork: %s", __func__, strerror(errno)); 1385 case 0: 1386 /* Child: master process continues mainloop */ 1387 break; 1388 default: 1389 /* Parent: set up mux slave to connect to backgrounded master */ 1390 debug2("%s: background process is %ld", __func__, (long)pid); 1391 stdin_null_flag = ostdin_null_flag; 1392 options.request_tty = orequest_tty; 1393 tty_flag = otty_flag; 1394 close(muxserver_sock); 1395 muxserver_sock = -1; 1396 options.control_master = SSHCTL_MASTER_NO; 1397 muxclient(options.control_path); 1398 /* muxclient() doesn't return on success. */ 1399 fatal("Failed to connect to new control master"); 1400 } 1401 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1402 error("%s: open(\"/dev/null\"): %s", __func__, 1403 strerror(errno)); 1404 } else { 1405 if (dup2(devnull, STDIN_FILENO) == -1 || 1406 dup2(devnull, STDOUT_FILENO) == -1) 1407 error("%s: dup2: %s", __func__, strerror(errno)); 1408 if (devnull > STDERR_FILENO) 1409 close(devnull); 1410 } 1411 daemon(1, 1); 1412 setproctitle("%s [mux]", options.control_path); 1413 } 1414 1415 /* Do fork() after authentication. Used by "ssh -f" */ 1416 static void 1417 fork_postauth(void) 1418 { 1419 if (need_controlpersist_detach) 1420 control_persist_detach(); 1421 debug("forking to background"); 1422 fork_after_authentication_flag = 0; 1423 if (daemon(1, 1) < 0) 1424 fatal("daemon() failed: %.200s", strerror(errno)); 1425 } 1426 1427 /* Callback for remote forward global requests */ 1428 static void 1429 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) 1430 { 1431 struct Forward *rfwd = (struct Forward *)ctxt; 1432 1433 /* XXX verbose() on failure? */ 1434 debug("remote forward %s for: listen %s%s%d, connect %s:%d", 1435 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1436 rfwd->listen_path ? rfwd->listen_path : 1437 rfwd->listen_host ? rfwd->listen_host : "", 1438 (rfwd->listen_path || rfwd->listen_host) ? ":" : "", 1439 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path : 1440 rfwd->connect_host, rfwd->connect_port); 1441 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) { 1442 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1443 rfwd->allocated_port = packet_get_int(); 1444 logit("Allocated port %u for remote forward to %s:%d", 1445 rfwd->allocated_port, 1446 rfwd->connect_host, rfwd->connect_port); 1447 channel_update_permitted_opens(rfwd->handle, 1448 rfwd->allocated_port); 1449 } else { 1450 channel_update_permitted_opens(rfwd->handle, -1); 1451 } 1452 } 1453 1454 if (type == SSH2_MSG_REQUEST_FAILURE) { 1455 if (options.exit_on_forward_failure) { 1456 if (rfwd->listen_path != NULL) 1457 fatal("Error: remote port forwarding failed " 1458 "for listen path %s", rfwd->listen_path); 1459 else 1460 fatal("Error: remote port forwarding failed " 1461 "for listen port %d", rfwd->listen_port); 1462 } else { 1463 if (rfwd->listen_path != NULL) 1464 logit("Warning: remote port forwarding failed " 1465 "for listen path %s", rfwd->listen_path); 1466 else 1467 logit("Warning: remote port forwarding failed " 1468 "for listen port %d", rfwd->listen_port); 1469 } 1470 } 1471 if (++remote_forward_confirms_received == options.num_remote_forwards) { 1472 debug("All remote forwarding requests processed"); 1473 if (fork_after_authentication_flag) 1474 fork_postauth(); 1475 } 1476 } 1477 1478 static void 1479 client_cleanup_stdio_fwd(int id, void *arg) 1480 { 1481 debug("stdio forwarding: done"); 1482 cleanup_exit(0); 1483 } 1484 1485 static void 1486 ssh_stdio_confirm(int id, int success, void *arg) 1487 { 1488 if (!success) 1489 fatal("stdio forwarding failed"); 1490 } 1491 1492 static void 1493 ssh_init_stdio_forwarding(void) 1494 { 1495 Channel *c; 1496 int in, out; 1497 1498 if (stdio_forward_host == NULL) 1499 return; 1500 if (!compat20) 1501 fatal("stdio forwarding require Protocol 2"); 1502 1503 debug3("%s: %s:%d", __func__, stdio_forward_host, stdio_forward_port); 1504 1505 if ((in = dup(STDIN_FILENO)) < 0 || 1506 (out = dup(STDOUT_FILENO)) < 0) 1507 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1508 if ((c = channel_connect_stdio_fwd(stdio_forward_host, 1509 stdio_forward_port, in, out)) == NULL) 1510 fatal("%s: channel_connect_stdio_fwd failed", __func__); 1511 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0); 1512 channel_register_open_confirm(c->self, ssh_stdio_confirm, NULL); 1513 } 1514 1515 static void 1516 ssh_init_forwarding(void) 1517 { 1518 int success = 0; 1519 int i; 1520 1521 /* Initiate local TCP/IP port forwardings. */ 1522 for (i = 0; i < options.num_local_forwards; i++) { 1523 debug("Local connections to %.200s:%d forwarded to remote " 1524 "address %.200s:%d", 1525 (options.local_forwards[i].listen_path != NULL) ? 1526 options.local_forwards[i].listen_path : 1527 (options.local_forwards[i].listen_host == NULL) ? 1528 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") : 1529 options.local_forwards[i].listen_host, 1530 options.local_forwards[i].listen_port, 1531 (options.local_forwards[i].connect_path != NULL) ? 1532 options.local_forwards[i].connect_path : 1533 options.local_forwards[i].connect_host, 1534 options.local_forwards[i].connect_port); 1535 success += channel_setup_local_fwd_listener( 1536 &options.local_forwards[i], &options.fwd_opts); 1537 } 1538 if (i > 0 && success != i && options.exit_on_forward_failure) 1539 fatal("Could not request local forwarding."); 1540 if (i > 0 && success == 0) 1541 error("Could not request local forwarding."); 1542 1543 /* Initiate remote TCP/IP port forwardings. */ 1544 for (i = 0; i < options.num_remote_forwards; i++) { 1545 debug("Remote connections from %.200s:%d forwarded to " 1546 "local address %.200s:%d", 1547 (options.remote_forwards[i].listen_path != NULL) ? 1548 options.remote_forwards[i].listen_path : 1549 (options.remote_forwards[i].listen_host == NULL) ? 1550 "LOCALHOST" : options.remote_forwards[i].listen_host, 1551 options.remote_forwards[i].listen_port, 1552 (options.remote_forwards[i].connect_path != NULL) ? 1553 options.remote_forwards[i].connect_path : 1554 options.remote_forwards[i].connect_host, 1555 options.remote_forwards[i].connect_port); 1556 options.remote_forwards[i].handle = 1557 channel_request_remote_forwarding( 1558 &options.remote_forwards[i]); 1559 if (options.remote_forwards[i].handle < 0) { 1560 if (options.exit_on_forward_failure) 1561 fatal("Could not request remote forwarding."); 1562 else 1563 logit("Warning: Could not request remote " 1564 "forwarding."); 1565 } else { 1566 client_register_global_confirm(ssh_confirm_remote_forward, 1567 &options.remote_forwards[i]); 1568 } 1569 } 1570 1571 /* Initiate tunnel forwarding. */ 1572 if (options.tun_open != SSH_TUNMODE_NO) { 1573 if (client_request_tun_fwd(options.tun_open, 1574 options.tun_local, options.tun_remote) == -1) { 1575 if (options.exit_on_forward_failure) 1576 fatal("Could not request tunnel forwarding."); 1577 else 1578 error("Could not request tunnel forwarding."); 1579 } 1580 } 1581 } 1582 1583 static void 1584 check_agent_present(void) 1585 { 1586 int r; 1587 1588 if (options.forward_agent) { 1589 /* Clear agent forwarding if we don't have an agent. */ 1590 if ((r = ssh_get_authentication_socket(NULL)) != 0) { 1591 options.forward_agent = 0; 1592 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1593 debug("ssh_get_authentication_socket: %s", 1594 ssh_err(r)); 1595 } 1596 } 1597 } 1598 1599 static int 1600 ssh_session(void) 1601 { 1602 int type; 1603 int interactive = 0; 1604 int have_tty = 0; 1605 struct winsize ws; 1606 char *cp; 1607 const char *display; 1608 1609 /* Enable compression if requested. */ 1610 if (options.compression) { 1611 debug("Requesting compression at level %d.", 1612 options.compression_level); 1613 1614 if (options.compression_level < 1 || 1615 options.compression_level > 9) 1616 fatal("Compression level must be from 1 (fast) to " 1617 "9 (slow, best)."); 1618 1619 /* Send the request. */ 1620 packet_start(SSH_CMSG_REQUEST_COMPRESSION); 1621 packet_put_int(options.compression_level); 1622 packet_send(); 1623 packet_write_wait(); 1624 type = packet_read(); 1625 if (type == SSH_SMSG_SUCCESS) 1626 packet_start_compression(options.compression_level); 1627 else if (type == SSH_SMSG_FAILURE) 1628 logit("Warning: Remote host refused compression."); 1629 else 1630 packet_disconnect("Protocol error waiting for " 1631 "compression response."); 1632 } 1633 /* Allocate a pseudo tty if appropriate. */ 1634 if (tty_flag) { 1635 debug("Requesting pty."); 1636 1637 /* Start the packet. */ 1638 packet_start(SSH_CMSG_REQUEST_PTY); 1639 1640 /* Store TERM in the packet. There is no limit on the 1641 length of the string. */ 1642 cp = getenv("TERM"); 1643 if (!cp) 1644 cp = ""; 1645 packet_put_cstring(cp); 1646 1647 /* Store window size in the packet. */ 1648 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 1649 memset(&ws, 0, sizeof(ws)); 1650 packet_put_int((u_int)ws.ws_row); 1651 packet_put_int((u_int)ws.ws_col); 1652 packet_put_int((u_int)ws.ws_xpixel); 1653 packet_put_int((u_int)ws.ws_ypixel); 1654 1655 /* Store tty modes in the packet. */ 1656 tty_make_modes(fileno(stdin), NULL); 1657 1658 /* Send the packet, and wait for it to leave. */ 1659 packet_send(); 1660 packet_write_wait(); 1661 1662 /* Read response from the server. */ 1663 type = packet_read(); 1664 if (type == SSH_SMSG_SUCCESS) { 1665 interactive = 1; 1666 have_tty = 1; 1667 } else if (type == SSH_SMSG_FAILURE) 1668 logit("Warning: Remote host failed or refused to " 1669 "allocate a pseudo tty."); 1670 else 1671 packet_disconnect("Protocol error waiting for pty " 1672 "request response."); 1673 } 1674 /* Request X11 forwarding if enabled and DISPLAY is set. */ 1675 display = getenv("DISPLAY"); 1676 if (options.forward_x11 && display != NULL) { 1677 char *proto, *data; 1678 /* Get reasonable local authentication information. */ 1679 client_x11_get_proto(display, options.xauth_location, 1680 options.forward_x11_trusted, 1681 options.forward_x11_timeout, 1682 &proto, &data); 1683 /* Request forwarding with authentication spoofing. */ 1684 debug("Requesting X11 forwarding with authentication " 1685 "spoofing."); 1686 x11_request_forwarding_with_spoofing(0, display, proto, 1687 data, 0); 1688 /* Read response from the server. */ 1689 type = packet_read(); 1690 if (type == SSH_SMSG_SUCCESS) { 1691 interactive = 1; 1692 } else if (type == SSH_SMSG_FAILURE) { 1693 logit("Warning: Remote host denied X11 forwarding."); 1694 } else { 1695 packet_disconnect("Protocol error waiting for X11 " 1696 "forwarding"); 1697 } 1698 } 1699 /* Tell the packet module whether this is an interactive session. */ 1700 packet_set_interactive(interactive, 1701 options.ip_qos_interactive, options.ip_qos_bulk); 1702 1703 /* Request authentication agent forwarding if appropriate. */ 1704 check_agent_present(); 1705 1706 if (options.forward_agent) { 1707 debug("Requesting authentication agent forwarding."); 1708 auth_request_forwarding(); 1709 1710 /* Read response from the server. */ 1711 type = packet_read(); 1712 packet_check_eom(); 1713 if (type != SSH_SMSG_SUCCESS) 1714 logit("Warning: Remote host denied authentication agent forwarding."); 1715 } 1716 1717 /* Initiate port forwardings. */ 1718 ssh_init_stdio_forwarding(); 1719 ssh_init_forwarding(); 1720 1721 /* Execute a local command */ 1722 if (options.local_command != NULL && 1723 options.permit_local_command) 1724 ssh_local_cmd(options.local_command); 1725 1726 /* 1727 * If requested and we are not interested in replies to remote 1728 * forwarding requests, then let ssh continue in the background. 1729 */ 1730 if (fork_after_authentication_flag) { 1731 if (options.exit_on_forward_failure && 1732 options.num_remote_forwards > 0) { 1733 debug("deferring postauth fork until remote forward " 1734 "confirmation received"); 1735 } else 1736 fork_postauth(); 1737 } 1738 1739 /* 1740 * If a command was specified on the command line, execute the 1741 * command now. Otherwise request the server to start a shell. 1742 */ 1743 if (buffer_len(&command) > 0) { 1744 int len = buffer_len(&command); 1745 if (len > 900) 1746 len = 900; 1747 debug("Sending command: %.*s", len, 1748 (u_char *)buffer_ptr(&command)); 1749 packet_start(SSH_CMSG_EXEC_CMD); 1750 packet_put_string(buffer_ptr(&command), buffer_len(&command)); 1751 packet_send(); 1752 packet_write_wait(); 1753 } else { 1754 debug("Requesting shell."); 1755 packet_start(SSH_CMSG_EXEC_SHELL); 1756 packet_send(); 1757 packet_write_wait(); 1758 } 1759 1760 /* Enter the interactive session. */ 1761 return client_loop(have_tty, tty_flag ? 1762 options.escape_char : SSH_ESCAPECHAR_NONE, 0); 1763 } 1764 1765 /* request pty/x11/agent/tcpfwd/shell for channel */ 1766 static void 1767 ssh_session2_setup(int id, int success, void *arg) 1768 { 1769 extern char **environ; 1770 const char *display; 1771 int interactive = tty_flag; 1772 1773 if (!success) 1774 return; /* No need for error message, channels code sens one */ 1775 1776 display = getenv("DISPLAY"); 1777 if (options.forward_x11 && display != NULL) { 1778 char *proto, *data; 1779 /* Get reasonable local authentication information. */ 1780 client_x11_get_proto(display, options.xauth_location, 1781 options.forward_x11_trusted, 1782 options.forward_x11_timeout, &proto, &data); 1783 /* Request forwarding with authentication spoofing. */ 1784 debug("Requesting X11 forwarding with authentication " 1785 "spoofing."); 1786 x11_request_forwarding_with_spoofing(id, display, proto, 1787 data, 1); 1788 client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN); 1789 /* XXX exit_on_forward_failure */ 1790 interactive = 1; 1791 } 1792 1793 check_agent_present(); 1794 if (options.forward_agent) { 1795 debug("Requesting authentication agent forwarding."); 1796 channel_request_start(id, "auth-agent-req (at) openssh.com", 0); 1797 packet_send(); 1798 } 1799 1800 /* Tell the packet module whether this is an interactive session. */ 1801 packet_set_interactive(interactive, 1802 options.ip_qos_interactive, options.ip_qos_bulk); 1803 1804 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), 1805 NULL, fileno(stdin), &command, environ); 1806 } 1807 1808 /* open new channel for a session */ 1809 static int 1810 ssh_session2_open(void) 1811 { 1812 Channel *c; 1813 int window, packetmax, in, out, err; 1814 1815 if (stdin_null_flag) { 1816 in = open(_PATH_DEVNULL, O_RDONLY); 1817 } else { 1818 in = dup(STDIN_FILENO); 1819 } 1820 out = dup(STDOUT_FILENO); 1821 err = dup(STDERR_FILENO); 1822 1823 if (in < 0 || out < 0 || err < 0) 1824 fatal("dup() in/out/err failed"); 1825 1826 /* enable nonblocking unless tty */ 1827 if (!isatty(in)) 1828 set_nonblock(in); 1829 if (!isatty(out)) 1830 set_nonblock(out); 1831 if (!isatty(err)) 1832 set_nonblock(err); 1833 1834 window = CHAN_SES_WINDOW_DEFAULT; 1835 packetmax = CHAN_SES_PACKET_DEFAULT; 1836 if (tty_flag) { 1837 window >>= 1; 1838 packetmax >>= 1; 1839 } 1840 c = channel_new( 1841 "session", SSH_CHANNEL_OPENING, in, out, err, 1842 window, packetmax, CHAN_EXTENDED_WRITE, 1843 "client-session", /*nonblock*/0); 1844 1845 debug3("ssh_session2_open: channel_new: %d", c->self); 1846 1847 channel_send_open(c->self); 1848 if (!no_shell_flag) 1849 channel_register_open_confirm(c->self, 1850 ssh_session2_setup, NULL); 1851 1852 return c->self; 1853 } 1854 1855 static int 1856 ssh_session2(void) 1857 { 1858 int id = -1; 1859 1860 /* XXX should be pre-session */ 1861 if (!options.control_persist) 1862 ssh_init_stdio_forwarding(); 1863 ssh_init_forwarding(); 1864 1865 /* Start listening for multiplex clients */ 1866 muxserver_listen(); 1867 1868 /* 1869 * If we are in control persist mode and have a working mux listen 1870 * socket, then prepare to background ourselves and have a foreground 1871 * client attach as a control slave. 1872 * NB. we must save copies of the flags that we override for 1873 * the backgrounding, since we defer attachment of the slave until 1874 * after the connection is fully established (in particular, 1875 * async rfwd replies have been received for ExitOnForwardFailure). 1876 */ 1877 if (options.control_persist && muxserver_sock != -1) { 1878 ostdin_null_flag = stdin_null_flag; 1879 ono_shell_flag = no_shell_flag; 1880 orequest_tty = options.request_tty; 1881 otty_flag = tty_flag; 1882 stdin_null_flag = 1; 1883 no_shell_flag = 1; 1884 tty_flag = 0; 1885 if (!fork_after_authentication_flag) 1886 need_controlpersist_detach = 1; 1887 fork_after_authentication_flag = 1; 1888 } 1889 /* 1890 * ControlPersist mux listen socket setup failed, attempt the 1891 * stdio forward setup that we skipped earlier. 1892 */ 1893 if (options.control_persist && muxserver_sock == -1) 1894 ssh_init_stdio_forwarding(); 1895 1896 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) 1897 id = ssh_session2_open(); 1898 else { 1899 packet_set_interactive( 1900 options.control_master == SSHCTL_MASTER_NO, 1901 options.ip_qos_interactive, options.ip_qos_bulk); 1902 } 1903 1904 /* If we don't expect to open a new session, then disallow it */ 1905 if (options.control_master == SSHCTL_MASTER_NO && 1906 (datafellows & SSH_NEW_OPENSSH)) { 1907 debug("Requesting no-more-sessions (at) openssh.com"); 1908 packet_start(SSH2_MSG_GLOBAL_REQUEST); 1909 packet_put_cstring("no-more-sessions (at) openssh.com"); 1910 packet_put_char(0); 1911 packet_send(); 1912 } 1913 1914 /* Execute a local command */ 1915 if (options.local_command != NULL && 1916 options.permit_local_command) 1917 ssh_local_cmd(options.local_command); 1918 1919 /* 1920 * If requested and we are not interested in replies to remote 1921 * forwarding requests, then let ssh continue in the background. 1922 */ 1923 if (fork_after_authentication_flag) { 1924 if (options.exit_on_forward_failure && 1925 options.num_remote_forwards > 0) { 1926 debug("deferring postauth fork until remote forward " 1927 "confirmation received"); 1928 } else 1929 fork_postauth(); 1930 } 1931 1932 if (options.use_roaming) 1933 request_roaming(); 1934 1935 return client_loop(tty_flag, tty_flag ? 1936 options.escape_char : SSH_ESCAPECHAR_NONE, id); 1937 } 1938 1939 static void 1940 load_public_identity_files(void) 1941 { 1942 char *filename, *cp, thishost[NI_MAXHOST]; 1943 char *pwdir = NULL, *pwname = NULL; 1944 int i = 0; 1945 Key *public; 1946 struct passwd *pw; 1947 u_int n_ids; 1948 char *identity_files[SSH_MAX_IDENTITY_FILES]; 1949 Key *identity_keys[SSH_MAX_IDENTITY_FILES]; 1950 #ifdef ENABLE_PKCS11 1951 Key **keys; 1952 int nkeys; 1953 #endif /* PKCS11 */ 1954 1955 n_ids = 0; 1956 memset(identity_files, 0, sizeof(identity_files)); 1957 memset(identity_keys, 0, sizeof(identity_keys)); 1958 1959 #ifdef ENABLE_PKCS11 1960 if (options.pkcs11_provider != NULL && 1961 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 1962 (pkcs11_init(!options.batch_mode) == 0) && 1963 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 1964 &keys)) > 0) { 1965 for (i = 0; i < nkeys; i++) { 1966 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 1967 key_free(keys[i]); 1968 continue; 1969 } 1970 identity_keys[n_ids] = keys[i]; 1971 identity_files[n_ids] = 1972 xstrdup(options.pkcs11_provider); /* XXX */ 1973 n_ids++; 1974 } 1975 free(keys); 1976 } 1977 #endif /* ENABLE_PKCS11 */ 1978 if ((pw = getpwuid(original_real_uid)) == NULL) 1979 fatal("load_public_identity_files: getpwuid failed"); 1980 pwname = xstrdup(pw->pw_name); 1981 pwdir = xstrdup(pw->pw_dir); 1982 if (gethostname(thishost, sizeof(thishost)) == -1) 1983 fatal("load_public_identity_files: gethostname: %s", 1984 strerror(errno)); 1985 for (i = 0; i < options.num_identity_files; i++) { 1986 if (n_ids >= SSH_MAX_IDENTITY_FILES || 1987 strcasecmp(options.identity_files[i], "none") == 0) { 1988 free(options.identity_files[i]); 1989 continue; 1990 } 1991 cp = tilde_expand_filename(options.identity_files[i], 1992 original_real_uid); 1993 filename = percent_expand(cp, "d", pwdir, 1994 "u", pwname, "l", thishost, "h", host, 1995 "r", options.user, (char *)NULL); 1996 free(cp); 1997 public = key_load_public(filename, NULL); 1998 debug("identity file %s type %d", filename, 1999 public ? public->type : -1); 2000 free(options.identity_files[i]); 2001 identity_files[n_ids] = filename; 2002 identity_keys[n_ids] = public; 2003 2004 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 2005 continue; 2006 2007 /* Try to add the certificate variant too */ 2008 xasprintf(&cp, "%s-cert", filename); 2009 public = key_load_public(cp, NULL); 2010 debug("identity file %s type %d", cp, 2011 public ? public->type : -1); 2012 if (public == NULL) { 2013 free(cp); 2014 continue; 2015 } 2016 if (!key_is_cert(public)) { 2017 debug("%s: key %s type %s is not a certificate", 2018 __func__, cp, key_type(public)); 2019 key_free(public); 2020 free(cp); 2021 continue; 2022 } 2023 identity_keys[n_ids] = public; 2024 /* point to the original path, most likely the private key */ 2025 identity_files[n_ids] = xstrdup(filename); 2026 n_ids++; 2027 } 2028 options.num_identity_files = n_ids; 2029 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 2030 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 2031 2032 explicit_bzero(pwname, strlen(pwname)); 2033 free(pwname); 2034 explicit_bzero(pwdir, strlen(pwdir)); 2035 free(pwdir); 2036 } 2037 2038 static void 2039 main_sigchld_handler(int sig) 2040 { 2041 int save_errno = errno; 2042 pid_t pid; 2043 int status; 2044 2045 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 2046 (pid < 0 && errno == EINTR)) 2047 ; 2048 2049 signal(sig, main_sigchld_handler); 2050 errno = save_errno; 2051 } 2052