1 /* $NetBSD: ssh.c,v 1.19 2015/08/13 10:33:21 christos Exp $ */ 2 /* $OpenBSD: ssh.c,v 1.420 2015/07/30 00:01:34 djm Exp $ */ 3 /* 4 * Author: Tatu Ylonen <ylo@cs.hut.fi> 5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 6 * All rights reserved 7 * Ssh client program. This program can be used to log into a remote machine. 8 * The software supports strong authentication, encryption, and forwarding 9 * of X11, TCP/IP, and authentication connections. 10 * 11 * As far as I am concerned, the code I have written for this software 12 * can be used freely for any purpose. Any derived versions of this 13 * software must be clearly marked as such, and if the derived work is 14 * incompatible with the protocol description in the RFC file, it must be 15 * called by a name other than "ssh" or "Secure Shell". 16 * 17 * Copyright (c) 1999 Niels Provos. All rights reserved. 18 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved. 19 * 20 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu> 21 * in Canada (German citizen). 22 * 23 * Redistribution and use in source and binary forms, with or without 24 * modification, are permitted provided that the following conditions 25 * are met: 26 * 1. Redistributions of source code must retain the above copyright 27 * notice, this list of conditions and the following disclaimer. 28 * 2. Redistributions in binary form must reproduce the above copyright 29 * notice, this list of conditions and the following disclaimer in the 30 * documentation and/or other materials provided with the distribution. 31 * 32 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 33 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 34 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 35 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 36 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 37 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 38 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 39 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 40 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 41 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 42 */ 43 44 #include "includes.h" 45 __RCSID("$NetBSD: ssh.c,v 1.19 2015/08/13 10:33:21 christos Exp $"); 46 #include <sys/types.h> 47 #include <sys/param.h> 48 #include <sys/ioctl.h> 49 #include <sys/queue.h> 50 #include <sys/resource.h> 51 #include <sys/socket.h> 52 #include <sys/stat.h> 53 #include <sys/time.h> 54 #include <sys/wait.h> 55 56 #include <ctype.h> 57 #include <errno.h> 58 #include <fcntl.h> 59 #include <netdb.h> 60 #include <paths.h> 61 #include <pwd.h> 62 #include <signal.h> 63 #include <stddef.h> 64 #include <stdio.h> 65 #include <stdlib.h> 66 #include <string.h> 67 #include <unistd.h> 68 #include <limits.h> 69 70 #include <netinet/in.h> 71 72 #ifdef WITH_OPENSSL 73 #include <openssl/evp.h> 74 #include <openssl/err.h> 75 #endif 76 77 #include "xmalloc.h" 78 #include "ssh.h" 79 #include "ssh1.h" 80 #include "ssh2.h" 81 #include "canohost.h" 82 #include "compat.h" 83 #include "cipher.h" 84 #include "digest.h" 85 #include "packet.h" 86 #include "buffer.h" 87 #include "channels.h" 88 #include "key.h" 89 #include "authfd.h" 90 #include "authfile.h" 91 #include "pathnames.h" 92 #include "dispatch.h" 93 #include "clientloop.h" 94 #include "log.h" 95 #include "misc.h" 96 #include "readconf.h" 97 #include "sshconnect.h" 98 #include "kex.h" 99 #include "mac.h" 100 #include "sshpty.h" 101 #include "match.h" 102 #include "msg.h" 103 #include "uidswap.h" 104 #include "roaming.h" 105 #include "version.h" 106 #include "ssherr.h" 107 #include "myproposal.h" 108 109 #ifdef ENABLE_PKCS11 110 #include "ssh-pkcs11.h" 111 #endif 112 113 extern char *__progname; 114 115 /* Flag indicating whether debug mode is on. May be set on the command line. */ 116 int debug_flag = 0; 117 118 /* Flag indicating whether a tty should be requested */ 119 int tty_flag = 0; 120 121 /* don't exec a shell */ 122 int no_shell_flag = 0; 123 124 /* 125 * Flag indicating that nothing should be read from stdin. This can be set 126 * on the command line. 127 */ 128 int stdin_null_flag = 0; 129 130 /* 131 * Flag indicating that the current process should be backgrounded and 132 * a new slave launched in the foreground for ControlPersist. 133 */ 134 int need_controlpersist_detach = 0; 135 136 /* Copies of flags for ControlPersist foreground slave */ 137 int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty; 138 139 /* 140 * Flag indicating that ssh should fork after authentication. This is useful 141 * so that the passphrase can be entered manually, and then ssh goes to the 142 * background. 143 */ 144 int fork_after_authentication_flag = 0; 145 146 /* forward stdio to remote host and port */ 147 char *stdio_forward_host = NULL; 148 int stdio_forward_port = 0; 149 150 /* 151 * General data structure for command line options and options configurable 152 * in configuration files. See readconf.h. 153 */ 154 Options options; 155 156 /* optional user configfile */ 157 char *config = NULL; 158 159 /* 160 * Name of the host we are connecting to. This is the name given on the 161 * command line, or the HostName specified for the user-supplied name in a 162 * configuration file. 163 */ 164 char *host; 165 166 /* socket address the host resolves to */ 167 struct sockaddr_storage hostaddr; 168 169 /* Private host keys. */ 170 Sensitive sensitive_data; 171 172 /* Original real UID. */ 173 uid_t original_real_uid; 174 uid_t original_effective_uid; 175 176 /* command to be executed */ 177 Buffer command; 178 179 /* Should we execute a command or invoke a subsystem? */ 180 int subsystem_flag = 0; 181 182 /* # of replies received for global requests */ 183 static int remote_forward_confirms_received = 0; 184 185 /* mux.c */ 186 extern int muxserver_sock; 187 extern u_int muxclient_command; 188 189 /* Prints a help message to the user. This function never returns. */ 190 191 __dead static void 192 usage(void) 193 { 194 fprintf(stderr, 195 "usage: ssh [-1246AaCfGgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n" 196 " [-D [bind_address:]port] [-E log_file] [-e escape_char]\n" 197 " [-F configfile] [-I pkcs11] [-i identity_file]\n" 198 " [-L address] [-l login_name] [-m mac_spec]\n" 199 " [-O ctl_cmd] [-o option] [-p port]\n" 200 " [-Q cipher | cipher-auth | mac | kex | key]\n" 201 " [-R address] [-S ctl_path] [-W host:port]\n" 202 " [-w local_tun[:remote_tun]] [user@]hostname [command]\n" 203 ); 204 exit(255); 205 } 206 207 static int ssh_session(void); 208 static int ssh_session2(void); 209 static void load_public_identity_files(void); 210 static void main_sigchld_handler(int); 211 212 /* from muxclient.c */ 213 void muxclient(const char *); 214 void muxserver_listen(void); 215 216 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 217 static void 218 tilde_expand_paths(char **paths, u_int num_paths) 219 { 220 u_int i; 221 char *cp; 222 223 for (i = 0; i < num_paths; i++) { 224 cp = tilde_expand_filename(paths[i], original_real_uid); 225 free(paths[i]); 226 paths[i] = cp; 227 } 228 } 229 230 /* 231 * Attempt to resolve a host name / port to a set of addresses and 232 * optionally return any CNAMEs encountered along the way. 233 * Returns NULL on failure. 234 * NB. this function must operate with a options having undefined members. 235 */ 236 static struct addrinfo * 237 resolve_host(const char *name, int port, int logerr, char *cname, size_t clen) 238 { 239 char strport[NI_MAXSERV]; 240 struct addrinfo hints, *res; 241 int gaierr, loglevel = SYSLOG_LEVEL_DEBUG1; 242 243 if (port <= 0) 244 port = default_ssh_port(); 245 246 snprintf(strport, sizeof strport, "%u", port); 247 memset(&hints, 0, sizeof(hints)); 248 hints.ai_family = options.address_family == -1 ? 249 AF_UNSPEC : options.address_family; 250 hints.ai_socktype = SOCK_STREAM; 251 if (cname != NULL) 252 hints.ai_flags = AI_CANONNAME; 253 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 254 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) 255 loglevel = SYSLOG_LEVEL_ERROR; 256 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", 257 __progname, name, ssh_gai_strerror(gaierr)); 258 return NULL; 259 } 260 if (cname != NULL && res->ai_canonname != NULL) { 261 if (strlcpy(cname, res->ai_canonname, clen) >= clen) { 262 error("%s: host \"%s\" cname \"%s\" too long (max %lu)", 263 __func__, name, res->ai_canonname, (u_long)clen); 264 if (clen > 0) 265 *cname = '\0'; 266 } 267 } 268 return res; 269 } 270 271 /* 272 * Attempt to resolve a numeric host address / port to a single address. 273 * Returns a canonical address string. 274 * Returns NULL on failure. 275 * NB. this function must operate with a options having undefined members. 276 */ 277 static struct addrinfo * 278 resolve_addr(const char *name, int port, char *caddr, size_t clen) 279 { 280 char addr[NI_MAXHOST], strport[NI_MAXSERV]; 281 struct addrinfo hints, *res; 282 int gaierr; 283 284 if (port <= 0) 285 port = default_ssh_port(); 286 snprintf(strport, sizeof strport, "%u", port); 287 memset(&hints, 0, sizeof(hints)); 288 hints.ai_family = options.address_family == -1 ? 289 AF_UNSPEC : options.address_family; 290 hints.ai_socktype = SOCK_STREAM; 291 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 292 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 293 debug2("%s: could not resolve name %.100s as address: %s", 294 __func__, name, ssh_gai_strerror(gaierr)); 295 return NULL; 296 } 297 if (res == NULL) { 298 debug("%s: getaddrinfo %.100s returned no addresses", 299 __func__, name); 300 return NULL; 301 } 302 if (res->ai_next != NULL) { 303 debug("%s: getaddrinfo %.100s returned multiple addresses", 304 __func__, name); 305 goto fail; 306 } 307 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen, 308 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) { 309 debug("%s: Could not format address for name %.100s: %s", 310 __func__, name, ssh_gai_strerror(gaierr)); 311 goto fail; 312 } 313 if (strlcpy(caddr, addr, clen) >= clen) { 314 error("%s: host \"%s\" addr \"%s\" too long (max %lu)", 315 __func__, name, addr, (u_long)clen); 316 if (clen > 0) 317 *caddr = '\0'; 318 fail: 319 freeaddrinfo(res); 320 return NULL; 321 } 322 return res; 323 } 324 325 /* 326 * Check whether the cname is a permitted replacement for the hostname 327 * and perform the replacement if it is. 328 * NB. this function must operate with a options having undefined members. 329 */ 330 static int 331 check_follow_cname(char **namep, const char *cname) 332 { 333 int i; 334 struct allowed_cname *rule; 335 336 if (*cname == '\0' || options.num_permitted_cnames == 0 || 337 strcmp(*namep, cname) == 0) 338 return 0; 339 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 340 return 0; 341 /* 342 * Don't attempt to canonicalize names that will be interpreted by 343 * a proxy unless the user specifically requests so. 344 */ 345 if (!option_clear_or_none(options.proxy_command) && 346 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 347 return 0; 348 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname); 349 for (i = 0; i < options.num_permitted_cnames; i++) { 350 rule = options.permitted_cnames + i; 351 if (match_pattern_list(*namep, rule->source_list, 1) != 1 || 352 match_pattern_list(cname, rule->target_list, 1) != 1) 353 continue; 354 verbose("Canonicalized DNS aliased hostname " 355 "\"%s\" => \"%s\"", *namep, cname); 356 free(*namep); 357 *namep = xstrdup(cname); 358 return 1; 359 } 360 return 0; 361 } 362 363 /* 364 * Attempt to resolve the supplied hostname after applying the user's 365 * canonicalization rules. Returns the address list for the host or NULL 366 * if no name was found after canonicalization. 367 * NB. this function must operate with a options having undefined members. 368 */ 369 static struct addrinfo * 370 resolve_canonicalize(char **hostp, int port) 371 { 372 int i, ndots; 373 char *cp, *fullhost, newname[NI_MAXHOST]; 374 struct addrinfo *addrs; 375 376 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 377 return NULL; 378 379 /* 380 * Don't attempt to canonicalize names that will be interpreted by 381 * a proxy unless the user specifically requests so. 382 */ 383 if (!option_clear_or_none(options.proxy_command) && 384 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 385 return NULL; 386 387 /* Try numeric hostnames first */ 388 if ((addrs = resolve_addr(*hostp, port, 389 newname, sizeof(newname))) != NULL) { 390 debug2("%s: hostname %.100s is address", __func__, *hostp); 391 if (strcasecmp(*hostp, newname) != 0) { 392 debug2("%s: canonicalised address \"%s\" => \"%s\"", 393 __func__, *hostp, newname); 394 free(*hostp); 395 *hostp = xstrdup(newname); 396 } 397 return addrs; 398 } 399 400 /* Don't apply canonicalization to sufficiently-qualified hostnames */ 401 ndots = 0; 402 for (cp = *hostp; *cp != '\0'; cp++) { 403 if (*cp == '.') 404 ndots++; 405 } 406 if (ndots > options.canonicalize_max_dots) { 407 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)", 408 __func__, *hostp, options.canonicalize_max_dots); 409 return NULL; 410 } 411 /* Attempt each supplied suffix */ 412 for (i = 0; i < options.num_canonical_domains; i++) { 413 *newname = '\0'; 414 xasprintf(&fullhost, "%s.%s.", *hostp, 415 options.canonical_domains[i]); 416 debug3("%s: attempting \"%s\" => \"%s\"", __func__, 417 *hostp, fullhost); 418 if ((addrs = resolve_host(fullhost, port, 0, 419 newname, sizeof(newname))) == NULL) { 420 free(fullhost); 421 continue; 422 } 423 /* Remove trailing '.' */ 424 fullhost[strlen(fullhost) - 1] = '\0'; 425 /* Follow CNAME if requested */ 426 if (!check_follow_cname(&fullhost, newname)) { 427 debug("Canonicalized hostname \"%s\" => \"%s\"", 428 *hostp, fullhost); 429 } 430 free(*hostp); 431 *hostp = fullhost; 432 return addrs; 433 } 434 if (!options.canonicalize_fallback_local) 435 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); 436 debug2("%s: host %s not found in any suffix", __func__, *hostp); 437 return NULL; 438 } 439 440 /* 441 * Read per-user configuration file. Ignore the system wide config 442 * file if the user specifies a config file on the command line. 443 */ 444 static void 445 process_config_files(const char *host_arg, struct passwd *pw, int post_canon) 446 { 447 char buf[PATH_MAX]; 448 int r; 449 450 if (config != NULL) { 451 if (strcasecmp(config, "none") != 0 && 452 !read_config_file(config, pw, host, host_arg, &options, 453 SSHCONF_USERCONF | (post_canon ? SSHCONF_POSTCANON : 0))) 454 fatal("Can't open user config file %.100s: " 455 "%.100s", config, strerror(errno)); 456 } else { 457 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 458 _PATH_SSH_USER_CONFFILE); 459 if (r > 0 && (size_t)r < sizeof(buf)) 460 (void)read_config_file(buf, pw, host, host_arg, 461 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF | 462 (post_canon ? SSHCONF_POSTCANON : 0)); 463 464 /* Read systemwide configuration file after user config. */ 465 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, 466 host, host_arg, &options, 467 post_canon ? SSHCONF_POSTCANON : 0); 468 } 469 } 470 471 /* Rewrite the port number in an addrinfo list of addresses */ 472 static void 473 set_addrinfo_port(struct addrinfo *addrs, int port) 474 { 475 struct addrinfo *addr; 476 477 for (addr = addrs; addr != NULL; addr = addr->ai_next) { 478 switch (addr->ai_family) { 479 case AF_INET: 480 ((struct sockaddr_in *)addr->ai_addr)-> 481 sin_port = htons(port); 482 break; 483 case AF_INET6: 484 ((struct sockaddr_in6 *)addr->ai_addr)-> 485 sin6_port = htons(port); 486 break; 487 } 488 } 489 } 490 491 /* 492 * Main program for the ssh client. 493 */ 494 int 495 main(int ac, char **av) 496 { 497 int i, r, opt, exit_status, use_syslog, config_test = 0; 498 char *p, *cp, *line, *argv0, buf[PATH_MAX], *host_arg, *logfile; 499 char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 500 char cname[NI_MAXHOST]; 501 struct stat st; 502 struct passwd *pw; 503 int timeout_ms; 504 extern int optind, optreset; 505 extern char *optarg; 506 struct Forward fwd; 507 struct addrinfo *addrs = NULL; 508 struct ssh_digest_ctx *md; 509 u_char conn_hash[SSH_DIGEST_MAX_LENGTH]; 510 char *conn_hash_hex; 511 512 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 513 sanitise_stdfd(); 514 515 /* 516 * Discard other fds that are hanging around. These can cause problem 517 * with backgrounded ssh processes started by ControlPersist. 518 */ 519 if (closefrom(STDERR_FILENO + 1) == -1) 520 fatal("closefrom failed: %.100s", strerror(errno)); 521 522 /* 523 * Save the original real uid. It will be needed later (uid-swapping 524 * may clobber the real uid). 525 */ 526 original_real_uid = getuid(); 527 original_effective_uid = geteuid(); 528 529 /* 530 * Use uid-swapping to give up root privileges for the duration of 531 * option processing. We will re-instantiate the rights when we are 532 * ready to create the privileged port, and will permanently drop 533 * them when the port has been created (actually, when the connection 534 * has been made, as we may need to create the port several times). 535 */ 536 PRIV_END; 537 538 /* If we are installed setuid root be careful to not drop core. */ 539 if (original_real_uid != original_effective_uid) { 540 struct rlimit rlim; 541 rlim.rlim_cur = rlim.rlim_max = 0; 542 if (setrlimit(RLIMIT_CORE, &rlim) < 0) 543 fatal("setrlimit failed: %.100s", strerror(errno)); 544 } 545 /* Get user data. */ 546 pw = getpwuid(original_real_uid); 547 if (!pw) { 548 logit("No user exists for uid %lu", (u_long)original_real_uid); 549 exit(255); 550 } 551 /* Take a copy of the returned structure. */ 552 pw = pwcopy(pw); 553 554 /* 555 * Set our umask to something reasonable, as some files are created 556 * with the default umask. This will make them world-readable but 557 * writable only by the owner, which is ok for all files for which we 558 * don't set the modes explicitly. 559 */ 560 umask(022); 561 562 /* 563 * Initialize option structure to indicate that no values have been 564 * set. 565 */ 566 initialize_options(&options); 567 568 /* Parse command-line arguments. */ 569 host = NULL; 570 use_syslog = 0; 571 logfile = NULL; 572 argv0 = av[0]; 573 574 again: 575 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 576 "ACD:E:F:GI:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { 577 switch (opt) { 578 case '1': 579 options.protocol = SSH_PROTO_1; 580 break; 581 case '2': 582 options.protocol = SSH_PROTO_2; 583 break; 584 case '4': 585 options.address_family = AF_INET; 586 break; 587 case '6': 588 options.address_family = AF_INET6; 589 break; 590 case 'n': 591 stdin_null_flag = 1; 592 break; 593 case 'f': 594 fork_after_authentication_flag = 1; 595 stdin_null_flag = 1; 596 break; 597 case 'x': 598 options.forward_x11 = 0; 599 break; 600 case 'X': 601 options.forward_x11 = 1; 602 break; 603 case 'y': 604 use_syslog = 1; 605 break; 606 case 'E': 607 logfile = xstrdup(optarg); 608 break; 609 case 'G': 610 config_test = 1; 611 break; 612 case 'Y': 613 options.forward_x11 = 1; 614 options.forward_x11_trusted = 1; 615 break; 616 case 'g': 617 options.fwd_opts.gateway_ports = 1; 618 break; 619 case 'O': 620 if (stdio_forward_host != NULL) 621 fatal("Cannot specify multiplexing " 622 "command with -W"); 623 else if (muxclient_command != 0) 624 fatal("Multiplexing command already specified"); 625 if (strcmp(optarg, "check") == 0) 626 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 627 else if (strcmp(optarg, "forward") == 0) 628 muxclient_command = SSHMUX_COMMAND_FORWARD; 629 else if (strcmp(optarg, "exit") == 0) 630 muxclient_command = SSHMUX_COMMAND_TERMINATE; 631 else if (strcmp(optarg, "stop") == 0) 632 muxclient_command = SSHMUX_COMMAND_STOP; 633 else if (strcmp(optarg, "cancel") == 0) 634 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 635 else 636 fatal("Invalid multiplex command."); 637 break; 638 case 'P': /* deprecated */ 639 options.use_privileged_port = 0; 640 break; 641 case 'Q': 642 cp = NULL; 643 if (strcmp(optarg, "cipher") == 0) 644 cp = cipher_alg_list('\n', 0); 645 else if (strcmp(optarg, "cipher-auth") == 0) 646 cp = cipher_alg_list('\n', 1); 647 else if (strcmp(optarg, "mac") == 0) 648 cp = mac_alg_list('\n'); 649 else if (strcmp(optarg, "kex") == 0) 650 cp = kex_alg_list('\n'); 651 else if (strcmp(optarg, "key") == 0) 652 cp = key_alg_list(0, 0); 653 else if (strcmp(optarg, "key-cert") == 0) 654 cp = key_alg_list(1, 0); 655 else if (strcmp(optarg, "key-plain") == 0) 656 cp = key_alg_list(0, 1); 657 else if (strcmp(optarg, "protocol-version") == 0) { 658 #ifdef WITH_SSH1 659 cp = xstrdup("1\n2"); 660 #else 661 cp = xstrdup("2"); 662 #endif 663 } 664 if (cp == NULL) 665 fatal("Unsupported query \"%s\"", optarg); 666 printf("%s\n", cp); 667 free(cp); 668 exit(0); 669 break; 670 case 'a': 671 options.forward_agent = 0; 672 break; 673 case 'A': 674 options.forward_agent = 1; 675 break; 676 case 'k': 677 options.gss_deleg_creds = 0; 678 break; 679 case 'K': 680 options.gss_authentication = 1; 681 options.gss_deleg_creds = 1; 682 break; 683 case 'i': 684 if (stat(optarg, &st) < 0) { 685 fprintf(stderr, "Warning: Identity file %s " 686 "not accessible: %s.\n", optarg, 687 strerror(errno)); 688 break; 689 } 690 add_identity_file(&options, NULL, optarg, 1); 691 break; 692 case 'I': 693 #ifdef ENABLE_PKCS11 694 options.pkcs11_provider = xstrdup(optarg); 695 #else 696 fprintf(stderr, "no support for PKCS#11.\n"); 697 #endif 698 break; 699 case 't': 700 if (options.request_tty == REQUEST_TTY_YES) 701 options.request_tty = REQUEST_TTY_FORCE; 702 else 703 options.request_tty = REQUEST_TTY_YES; 704 break; 705 case 'v': 706 if (debug_flag == 0) { 707 debug_flag = 1; 708 options.log_level = SYSLOG_LEVEL_DEBUG1; 709 } else { 710 if (options.log_level < SYSLOG_LEVEL_DEBUG3) 711 options.log_level++; 712 } 713 break; 714 case 'V': 715 fprintf(stderr, "%s, %s\n", 716 SSH_VERSION, 717 #ifdef WITH_OPENSSL 718 SSLeay_version(SSLEAY_VERSION) 719 #else 720 "without OpenSSL" 721 #endif 722 ); 723 if (opt == 'V') 724 exit(0); 725 break; 726 case 'w': 727 if (options.tun_open == -1) 728 options.tun_open = SSH_TUNMODE_DEFAULT; 729 options.tun_local = a2tun(optarg, &options.tun_remote); 730 if (options.tun_local == SSH_TUNID_ERR) { 731 fprintf(stderr, 732 "Bad tun device '%s'\n", optarg); 733 exit(255); 734 } 735 break; 736 case 'W': 737 if (stdio_forward_host != NULL) 738 fatal("stdio forward already specified"); 739 if (muxclient_command != 0) 740 fatal("Cannot specify stdio forward with -O"); 741 if (parse_forward(&fwd, optarg, 1, 0)) { 742 stdio_forward_host = fwd.listen_host; 743 stdio_forward_port = fwd.listen_port; 744 free(fwd.connect_host); 745 } else { 746 fprintf(stderr, 747 "Bad stdio forwarding specification '%s'\n", 748 optarg); 749 exit(255); 750 } 751 options.request_tty = REQUEST_TTY_NO; 752 no_shell_flag = 1; 753 options.clear_forwardings = 1; 754 options.exit_on_forward_failure = 1; 755 break; 756 case 'q': 757 options.log_level = SYSLOG_LEVEL_QUIET; 758 break; 759 case 'e': 760 if (optarg[0] == '^' && optarg[2] == 0 && 761 (u_char) optarg[1] >= 64 && 762 (u_char) optarg[1] < 128) 763 options.escape_char = (u_char) optarg[1] & 31; 764 else if (strlen(optarg) == 1) 765 options.escape_char = (u_char) optarg[0]; 766 else if (strcmp(optarg, "none") == 0) 767 options.escape_char = SSH_ESCAPECHAR_NONE; 768 else { 769 fprintf(stderr, "Bad escape character '%s'.\n", 770 optarg); 771 exit(255); 772 } 773 break; 774 case 'c': 775 if (ciphers_valid(*optarg == '+' ? 776 optarg + 1 : optarg)) { 777 /* SSH2 only */ 778 options.ciphers = xstrdup(optarg); 779 options.cipher = SSH_CIPHER_INVALID; 780 break; 781 } 782 /* SSH1 only */ 783 options.cipher = cipher_number(optarg); 784 if (options.cipher == -1) { 785 fprintf(stderr, "Unknown cipher type '%s'\n", 786 optarg); 787 exit(255); 788 } 789 if (options.cipher == SSH_CIPHER_3DES) 790 options.ciphers = xstrdup("3des-cbc"); 791 else if (options.cipher == SSH_CIPHER_BLOWFISH) 792 options.ciphers = xstrdup("blowfish-cbc"); 793 else 794 options.ciphers = xstrdup(KEX_CLIENT_ENCRYPT); 795 break; 796 case 'm': 797 if (mac_valid(optarg)) 798 options.macs = xstrdup(optarg); 799 else { 800 fprintf(stderr, "Unknown mac type '%s'\n", 801 optarg); 802 exit(255); 803 } 804 break; 805 case 'M': 806 if (options.control_master == SSHCTL_MASTER_YES) 807 options.control_master = SSHCTL_MASTER_ASK; 808 else 809 options.control_master = SSHCTL_MASTER_YES; 810 break; 811 case 'p': 812 options.port = a2port(optarg); 813 if (options.port <= 0) { 814 fprintf(stderr, "Bad port '%s'\n", optarg); 815 exit(255); 816 } 817 break; 818 case 'l': 819 options.user = optarg; 820 break; 821 822 case 'L': 823 if (parse_forward(&fwd, optarg, 0, 0)) 824 add_local_forward(&options, &fwd); 825 else { 826 fprintf(stderr, 827 "Bad local forwarding specification '%s'\n", 828 optarg); 829 exit(255); 830 } 831 break; 832 833 case 'R': 834 if (parse_forward(&fwd, optarg, 0, 1)) { 835 add_remote_forward(&options, &fwd); 836 } else { 837 fprintf(stderr, 838 "Bad remote forwarding specification " 839 "'%s'\n", optarg); 840 exit(255); 841 } 842 break; 843 844 case 'D': 845 if (parse_forward(&fwd, optarg, 1, 0)) { 846 add_local_forward(&options, &fwd); 847 } else { 848 fprintf(stderr, 849 "Bad dynamic forwarding specification " 850 "'%s'\n", optarg); 851 exit(255); 852 } 853 break; 854 855 case 'C': 856 options.compression = 1; 857 break; 858 case 'N': 859 no_shell_flag = 1; 860 options.request_tty = REQUEST_TTY_NO; 861 break; 862 case 'T': 863 options.request_tty = REQUEST_TTY_NO; 864 /* ensure that the user doesn't try to backdoor a */ 865 /* null cipher switch on an interactive session */ 866 /* so explicitly disable it no matter what */ 867 options.none_switch = 0; 868 break; 869 case 'o': 870 line = xstrdup(optarg); 871 if (process_config_line(&options, pw, 872 host ? host : "", host ? host : "", line, 873 "command-line", 0, NULL, SSHCONF_USERCONF) != 0) 874 exit(255); 875 free(line); 876 break; 877 case 's': 878 subsystem_flag = 1; 879 break; 880 case 'S': 881 if (options.control_path != NULL) 882 free(options.control_path); 883 options.control_path = xstrdup(optarg); 884 break; 885 case 'b': 886 options.bind_address = optarg; 887 break; 888 case 'F': 889 config = optarg; 890 break; 891 default: 892 usage(); 893 } 894 } 895 896 ac -= optind; 897 av += optind; 898 899 if (ac > 0 && !host) { 900 if (strrchr(*av, '@')) { 901 p = xstrdup(*av); 902 cp = strrchr(p, '@'); 903 if (cp == NULL || cp == p) 904 usage(); 905 options.user = p; 906 *cp = '\0'; 907 host = xstrdup(++cp); 908 } else 909 host = xstrdup(*av); 910 if (ac > 1) { 911 optind = optreset = 1; 912 goto again; 913 } 914 ac--, av++; 915 } 916 917 /* Check that we got a host name. */ 918 if (!host) 919 usage(); 920 921 host_arg = xstrdup(host); 922 923 #ifdef WITH_OPENSSL 924 OpenSSL_add_all_algorithms(); 925 ERR_load_crypto_strings(); 926 #endif 927 928 /* Initialize the command to execute on remote host. */ 929 buffer_init(&command); 930 931 /* 932 * Save the command to execute on the remote host in a buffer. There 933 * is no limit on the length of the command, except by the maximum 934 * packet size. Also sets the tty flag if there is no command. 935 */ 936 if (!ac) { 937 /* No command specified - execute shell on a tty. */ 938 if (subsystem_flag) { 939 fprintf(stderr, 940 "You must specify a subsystem to invoke.\n"); 941 usage(); 942 } 943 } else { 944 /* A command has been specified. Store it into the buffer. */ 945 for (i = 0; i < ac; i++) { 946 if (i) 947 buffer_append(&command, " ", 1); 948 buffer_append(&command, av[i], strlen(av[i])); 949 } 950 } 951 952 /* Cannot fork to background if no command. */ 953 if (fork_after_authentication_flag && buffer_len(&command) == 0 && 954 !no_shell_flag) 955 fatal("Cannot fork into background without a command " 956 "to execute."); 957 958 /* 959 * Initialize "log" output. Since we are the client all output 960 * goes to stderr unless otherwise specified by -y or -E. 961 */ 962 if (use_syslog && logfile != NULL) 963 fatal("Can't specify both -y and -E"); 964 if (logfile != NULL) { 965 log_redirect_stderr_to(logfile); 966 free(logfile); 967 } 968 log_init(argv0, 969 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, 970 SYSLOG_FACILITY_USER, !use_syslog); 971 972 if (debug_flag) 973 logit("%s, %s", SSH_VERSION, 974 #ifdef WITH_OPENSSL 975 SSLeay_version(SSLEAY_VERSION) 976 #else 977 "without OpenSSL" 978 #endif 979 ); 980 981 /* Parse the configuration files */ 982 process_config_files(host_arg, pw, 0); 983 984 /* Hostname canonicalisation needs a few options filled. */ 985 fill_default_options_for_canonicalization(&options); 986 987 /* If the user has replaced the hostname then take it into use now */ 988 if (options.hostname != NULL) { 989 /* NB. Please keep in sync with readconf.c:match_cfg_line() */ 990 cp = percent_expand(options.hostname, 991 "h", host, (char *)NULL); 992 free(host); 993 host = cp; 994 free(options.hostname); 995 options.hostname = xstrdup(host); 996 } 997 998 /* If canonicalization requested then try to apply it */ 999 lowercase(host); 1000 if (options.canonicalize_hostname != SSH_CANONICALISE_NO) 1001 addrs = resolve_canonicalize(&host, options.port); 1002 1003 /* 1004 * If CanonicalizePermittedCNAMEs have been specified but 1005 * other canonicalization did not happen (by not being requested 1006 * or by failing with fallback) then the hostname may still be changed 1007 * as a result of CNAME following. 1008 * 1009 * Try to resolve the bare hostname name using the system resolver's 1010 * usual search rules and then apply the CNAME follow rules. 1011 * 1012 * Skip the lookup if a ProxyCommand is being used unless the user 1013 * has specifically requested canonicalisation for this case via 1014 * CanonicalizeHostname=always 1015 */ 1016 if (addrs == NULL && options.num_permitted_cnames != 0 && 1017 (option_clear_or_none(options.proxy_command) || 1018 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { 1019 if ((addrs = resolve_host(host, options.port, 1020 option_clear_or_none(options.proxy_command), 1021 cname, sizeof(cname))) == NULL) { 1022 /* Don't fatal proxied host names not in the DNS */ 1023 if (option_clear_or_none(options.proxy_command)) 1024 cleanup_exit(255); /* logged in resolve_host */ 1025 } else 1026 check_follow_cname(&host, cname); 1027 } 1028 1029 /* 1030 * If canonicalisation is enabled then re-parse the configuration 1031 * files as new stanzas may match. 1032 */ 1033 if (options.canonicalize_hostname != 0) { 1034 debug("Re-reading configuration after hostname " 1035 "canonicalisation"); 1036 free(options.hostname); 1037 options.hostname = xstrdup(host); 1038 process_config_files(host_arg, pw, 1); 1039 /* 1040 * Address resolution happens early with canonicalisation 1041 * enabled and the port number may have changed since, so 1042 * reset it in address list 1043 */ 1044 if (addrs != NULL && options.port > 0) 1045 set_addrinfo_port(addrs, options.port); 1046 } 1047 1048 /* Fill configuration defaults. */ 1049 fill_default_options(&options); 1050 1051 if (options.port == 0) 1052 options.port = default_ssh_port(); 1053 channel_set_af(options.address_family); 1054 1055 /* Tidy and check options */ 1056 if (options.host_key_alias != NULL) 1057 lowercase(options.host_key_alias); 1058 if (options.proxy_command != NULL && 1059 strcmp(options.proxy_command, "-") == 0 && 1060 options.proxy_use_fdpass) 1061 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); 1062 if (options.control_persist && 1063 options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 1064 debug("UpdateHostKeys=ask is incompatible with ControlPersist; " 1065 "disabling"); 1066 options.update_hostkeys = 0; 1067 } 1068 if (original_effective_uid != 0) 1069 options.use_privileged_port = 0; 1070 1071 /* reinit */ 1072 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog); 1073 1074 if (options.request_tty == REQUEST_TTY_YES || 1075 options.request_tty == REQUEST_TTY_FORCE) 1076 tty_flag = 1; 1077 1078 /* Allocate a tty by default if no command specified. */ 1079 if (buffer_len(&command) == 0) 1080 tty_flag = options.request_tty != REQUEST_TTY_NO; 1081 1082 /* Force no tty */ 1083 if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0) 1084 tty_flag = 0; 1085 /* Do not allocate a tty if stdin is not a tty. */ 1086 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 1087 options.request_tty != REQUEST_TTY_FORCE) { 1088 if (tty_flag) 1089 logit("Pseudo-terminal will not be allocated because " 1090 "stdin is not a terminal."); 1091 tty_flag = 0; 1092 } 1093 1094 if (options.user == NULL) 1095 options.user = xstrdup(pw->pw_name); 1096 1097 if (gethostname(thishost, sizeof(thishost)) == -1) 1098 fatal("gethostname: %s", strerror(errno)); 1099 strlcpy(shorthost, thishost, sizeof(shorthost)); 1100 shorthost[strcspn(thishost, ".")] = '\0'; 1101 snprintf(portstr, sizeof(portstr), "%d", options.port); 1102 1103 if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL || 1104 ssh_digest_update(md, thishost, strlen(thishost)) < 0 || 1105 ssh_digest_update(md, host, strlen(host)) < 0 || 1106 ssh_digest_update(md, portstr, strlen(portstr)) < 0 || 1107 ssh_digest_update(md, options.user, strlen(options.user)) < 0 || 1108 ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0) 1109 fatal("%s: mux digest failed", __func__); 1110 ssh_digest_free(md); 1111 conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1)); 1112 1113 if (options.local_command != NULL) { 1114 debug3("expanding LocalCommand: %s", options.local_command); 1115 cp = options.local_command; 1116 options.local_command = percent_expand(cp, 1117 "C", conn_hash_hex, 1118 "L", shorthost, 1119 "d", pw->pw_dir, 1120 "h", host, 1121 "l", thishost, 1122 "n", host_arg, 1123 "p", portstr, 1124 "r", options.user, 1125 "u", pw->pw_name, 1126 (char *)NULL); 1127 debug3("expanded LocalCommand: %s", options.local_command); 1128 free(cp); 1129 } 1130 1131 if (options.control_path != NULL) { 1132 cp = tilde_expand_filename(options.control_path, 1133 original_real_uid); 1134 free(options.control_path); 1135 options.control_path = percent_expand(cp, 1136 "C", conn_hash_hex, 1137 "L", shorthost, 1138 "h", host, 1139 "l", thishost, 1140 "n", host_arg, 1141 "p", portstr, 1142 "r", options.user, 1143 "u", pw->pw_name, 1144 (char *)NULL); 1145 free(cp); 1146 } 1147 free(conn_hash_hex); 1148 1149 if (config_test) { 1150 dump_client_config(&options, host); 1151 exit(0); 1152 } 1153 1154 if (muxclient_command != 0 && options.control_path == NULL) 1155 fatal("No ControlPath specified for \"-O\" command"); 1156 if (options.control_path != NULL) 1157 muxclient(options.control_path); 1158 1159 /* 1160 * If hostname canonicalisation was not enabled, then we may not 1161 * have yet resolved the hostname. Do so now. 1162 */ 1163 if (addrs == NULL && options.proxy_command == NULL) { 1164 if ((addrs = resolve_host(host, options.port, 1, 1165 cname, sizeof(cname))) == NULL) 1166 cleanup_exit(255); /* resolve_host logs the error */ 1167 } 1168 1169 timeout_ms = options.connection_timeout * 1000; 1170 1171 /* Open a connection to the remote host. */ 1172 if (ssh_connect(host, addrs, &hostaddr, options.port, 1173 options.address_family, options.connection_attempts, 1174 &timeout_ms, options.tcp_keep_alive, 1175 options.use_privileged_port) != 0) 1176 exit(255); 1177 1178 if (addrs != NULL) 1179 freeaddrinfo(addrs); 1180 1181 packet_set_timeout(options.server_alive_interval, 1182 options.server_alive_count_max); 1183 1184 if (timeout_ms > 0) 1185 debug3("timeout: %d ms remain after connect", timeout_ms); 1186 1187 /* 1188 * If we successfully made the connection, load the host private key 1189 * in case we will need it later for combined rsa-rhosts 1190 * authentication. This must be done before releasing extra 1191 * privileges, because the file is only readable by root. 1192 * If we cannot access the private keys, load the public keys 1193 * instead and try to execute the ssh-keysign helper instead. 1194 */ 1195 sensitive_data.nkeys = 0; 1196 sensitive_data.keys = NULL; 1197 sensitive_data.external_keysign = 0; 1198 if (options.rhosts_rsa_authentication || 1199 options.hostbased_authentication) { 1200 sensitive_data.nkeys = 9; 1201 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 1202 sizeof(Key)); 1203 1204 PRIV_START; 1205 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, 1206 _PATH_HOST_KEY_FILE, "", NULL, NULL); 1207 sensitive_data.keys[1] = key_load_private_cert(KEY_ECDSA, 1208 _PATH_HOST_ECDSA_KEY_FILE, "", NULL); 1209 sensitive_data.keys[2] = key_load_private_cert(KEY_ED25519, 1210 _PATH_HOST_ED25519_KEY_FILE, "", NULL); 1211 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA, 1212 _PATH_HOST_RSA_KEY_FILE, "", NULL); 1213 sensitive_data.keys[4] = key_load_private_cert(KEY_DSA, 1214 _PATH_HOST_DSA_KEY_FILE, "", NULL); 1215 sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA, 1216 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL); 1217 sensitive_data.keys[6] = key_load_private_type(KEY_ED25519, 1218 _PATH_HOST_ED25519_KEY_FILE, "", NULL, NULL); 1219 sensitive_data.keys[7] = key_load_private_type(KEY_RSA, 1220 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); 1221 sensitive_data.keys[8] = key_load_private_type(KEY_DSA, 1222 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); 1223 PRIV_END; 1224 1225 if (options.hostbased_authentication == 1 && 1226 sensitive_data.keys[0] == NULL && 1227 sensitive_data.keys[5] == NULL && 1228 sensitive_data.keys[6] == NULL && 1229 sensitive_data.keys[7] == NULL && 1230 sensitive_data.keys[8] == NULL) { 1231 sensitive_data.keys[1] = key_load_cert( 1232 _PATH_HOST_ECDSA_KEY_FILE); 1233 sensitive_data.keys[2] = key_load_cert( 1234 _PATH_HOST_ED25519_KEY_FILE); 1235 sensitive_data.keys[3] = key_load_cert( 1236 _PATH_HOST_RSA_KEY_FILE); 1237 sensitive_data.keys[4] = key_load_cert( 1238 _PATH_HOST_DSA_KEY_FILE); 1239 sensitive_data.keys[5] = key_load_public( 1240 _PATH_HOST_ECDSA_KEY_FILE, NULL); 1241 sensitive_data.keys[6] = key_load_public( 1242 _PATH_HOST_ED25519_KEY_FILE, NULL); 1243 sensitive_data.keys[7] = key_load_public( 1244 _PATH_HOST_RSA_KEY_FILE, NULL); 1245 sensitive_data.keys[8] = key_load_public( 1246 _PATH_HOST_DSA_KEY_FILE, NULL); 1247 sensitive_data.external_keysign = 1; 1248 } 1249 } 1250 /* 1251 * Get rid of any extra privileges that we may have. We will no 1252 * longer need them. Also, extra privileges could make it very hard 1253 * to read identity files and other non-world-readable files from the 1254 * user's home directory if it happens to be on a NFS volume where 1255 * root is mapped to nobody. 1256 */ 1257 if (original_effective_uid == 0) { 1258 PRIV_START; 1259 permanently_set_uid(pw); 1260 } 1261 1262 /* 1263 * Now that we are back to our own permissions, create ~/.ssh 1264 * directory if it doesn't already exist. 1265 */ 1266 if (config == NULL) { 1267 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 1268 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 1269 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) 1270 if (mkdir(buf, 0700) < 0) 1271 error("Could not create directory '%.200s'.", 1272 buf); 1273 } 1274 1275 /* load options.identity_files */ 1276 load_public_identity_files(); 1277 1278 /* Expand ~ in known host file names. */ 1279 tilde_expand_paths(options.system_hostfiles, 1280 options.num_system_hostfiles); 1281 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 1282 1283 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 1284 signal(SIGCHLD, main_sigchld_handler); 1285 1286 /* Log into the remote system. Never returns if the login fails. */ 1287 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, 1288 options.port, pw, timeout_ms); 1289 1290 if (packet_connection_is_on_socket()) { 1291 verbose("Authenticated to %s ([%s]:%d).", host, 1292 get_remote_ipaddr(), get_remote_port()); 1293 } else { 1294 verbose("Authenticated to %s (via proxy).", host); 1295 } 1296 1297 /* We no longer need the private host keys. Clear them now. */ 1298 if (sensitive_data.nkeys != 0) { 1299 for (i = 0; i < sensitive_data.nkeys; i++) { 1300 if (sensitive_data.keys[i] != NULL) { 1301 /* Destroys contents safely */ 1302 debug3("clear hostkey %d", i); 1303 key_free(sensitive_data.keys[i]); 1304 sensitive_data.keys[i] = NULL; 1305 } 1306 } 1307 free(sensitive_data.keys); 1308 } 1309 for (i = 0; i < options.num_identity_files; i++) { 1310 free(options.identity_files[i]); 1311 options.identity_files[i] = NULL; 1312 if (options.identity_keys[i]) { 1313 key_free(options.identity_keys[i]); 1314 options.identity_keys[i] = NULL; 1315 } 1316 } 1317 1318 exit_status = compat20 ? ssh_session2() : ssh_session(); 1319 packet_close(); 1320 1321 if (options.control_path != NULL && muxserver_sock != -1) 1322 unlink(options.control_path); 1323 1324 /* Kill ProxyCommand if it is running. */ 1325 ssh_kill_proxy_command(); 1326 1327 return exit_status; 1328 } 1329 1330 static void 1331 control_persist_detach(void) 1332 { 1333 pid_t pid; 1334 int devnull; 1335 1336 debug("%s: backgrounding master process", __func__); 1337 1338 /* 1339 * master (current process) into the background, and make the 1340 * foreground process a client of the backgrounded master. 1341 */ 1342 switch ((pid = fork())) { 1343 case -1: 1344 fatal("%s: fork: %s", __func__, strerror(errno)); 1345 case 0: 1346 /* Child: master process continues mainloop */ 1347 break; 1348 default: 1349 /* Parent: set up mux slave to connect to backgrounded master */ 1350 debug2("%s: background process is %ld", __func__, (long)pid); 1351 stdin_null_flag = ostdin_null_flag; 1352 options.request_tty = orequest_tty; 1353 tty_flag = otty_flag; 1354 close(muxserver_sock); 1355 muxserver_sock = -1; 1356 options.control_master = SSHCTL_MASTER_NO; 1357 muxclient(options.control_path); 1358 /* muxclient() doesn't return on success. */ 1359 fatal("Failed to connect to new control master"); 1360 } 1361 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1362 error("%s: open(\"/dev/null\"): %s", __func__, 1363 strerror(errno)); 1364 } else { 1365 if (dup2(devnull, STDIN_FILENO) == -1 || 1366 dup2(devnull, STDOUT_FILENO) == -1) 1367 error("%s: dup2: %s", __func__, strerror(errno)); 1368 if (devnull > STDERR_FILENO) 1369 close(devnull); 1370 } 1371 daemon(1, 1); 1372 setproctitle("%s [mux]", options.control_path); 1373 } 1374 1375 /* Do fork() after authentication. Used by "ssh -f" */ 1376 static void 1377 fork_postauth(void) 1378 { 1379 if (need_controlpersist_detach) 1380 control_persist_detach(); 1381 debug("forking to background"); 1382 fork_after_authentication_flag = 0; 1383 if (daemon(1, 1) < 0) 1384 fatal("daemon() failed: %.200s", strerror(errno)); 1385 } 1386 1387 /* Callback for remote forward global requests */ 1388 static void 1389 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) 1390 { 1391 struct Forward *rfwd = (struct Forward *)ctxt; 1392 1393 /* XXX verbose() on failure? */ 1394 debug("remote forward %s for: listen %s%s%d, connect %s:%d", 1395 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1396 rfwd->listen_path ? rfwd->listen_path : 1397 rfwd->listen_host ? rfwd->listen_host : "", 1398 (rfwd->listen_path || rfwd->listen_host) ? ":" : "", 1399 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path : 1400 rfwd->connect_host, rfwd->connect_port); 1401 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) { 1402 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1403 rfwd->allocated_port = packet_get_int(); 1404 logit("Allocated port %u for remote forward to %s:%d", 1405 rfwd->allocated_port, 1406 rfwd->connect_host, rfwd->connect_port); 1407 channel_update_permitted_opens(rfwd->handle, 1408 rfwd->allocated_port); 1409 } else { 1410 channel_update_permitted_opens(rfwd->handle, -1); 1411 } 1412 } 1413 1414 if (type == SSH2_MSG_REQUEST_FAILURE) { 1415 if (options.exit_on_forward_failure) { 1416 if (rfwd->listen_path != NULL) 1417 fatal("Error: remote port forwarding failed " 1418 "for listen path %s", rfwd->listen_path); 1419 else 1420 fatal("Error: remote port forwarding failed " 1421 "for listen port %d", rfwd->listen_port); 1422 } else { 1423 if (rfwd->listen_path != NULL) 1424 logit("Warning: remote port forwarding failed " 1425 "for listen path %s", rfwd->listen_path); 1426 else 1427 logit("Warning: remote port forwarding failed " 1428 "for listen port %d", rfwd->listen_port); 1429 } 1430 } 1431 if (++remote_forward_confirms_received == options.num_remote_forwards) { 1432 debug("All remote forwarding requests processed"); 1433 if (fork_after_authentication_flag) 1434 fork_postauth(); 1435 } 1436 } 1437 1438 __dead static void 1439 client_cleanup_stdio_fwd(int id, void *arg) 1440 { 1441 debug("stdio forwarding: done"); 1442 cleanup_exit(0); 1443 } 1444 1445 static void 1446 ssh_stdio_confirm(int id, int success, void *arg) 1447 { 1448 if (!success) 1449 fatal("stdio forwarding failed"); 1450 } 1451 1452 static void 1453 ssh_init_stdio_forwarding(void) 1454 { 1455 Channel *c; 1456 int in, out; 1457 1458 if (stdio_forward_host == NULL) 1459 return; 1460 if (!compat20) 1461 fatal("stdio forwarding require Protocol 2"); 1462 1463 debug3("%s: %s:%d", __func__, stdio_forward_host, stdio_forward_port); 1464 1465 if ((in = dup(STDIN_FILENO)) < 0 || 1466 (out = dup(STDOUT_FILENO)) < 0) 1467 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1468 if ((c = channel_connect_stdio_fwd(stdio_forward_host, 1469 stdio_forward_port, in, out)) == NULL) 1470 fatal("%s: channel_connect_stdio_fwd failed", __func__); 1471 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0); 1472 channel_register_open_confirm(c->self, ssh_stdio_confirm, NULL); 1473 } 1474 1475 static void 1476 ssh_init_forwarding(void) 1477 { 1478 int success = 0; 1479 int i; 1480 1481 /* Initiate local TCP/IP port forwardings. */ 1482 for (i = 0; i < options.num_local_forwards; i++) { 1483 debug("Local connections to %.200s:%d forwarded to remote " 1484 "address %.200s:%d", 1485 (options.local_forwards[i].listen_path != NULL) ? 1486 options.local_forwards[i].listen_path : 1487 (options.local_forwards[i].listen_host == NULL) ? 1488 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") : 1489 options.local_forwards[i].listen_host, 1490 options.local_forwards[i].listen_port, 1491 (options.local_forwards[i].connect_path != NULL) ? 1492 options.local_forwards[i].connect_path : 1493 options.local_forwards[i].connect_host, 1494 options.local_forwards[i].connect_port); 1495 success += channel_setup_local_fwd_listener( 1496 &options.local_forwards[i], &options.fwd_opts); 1497 } 1498 if (i > 0 && success != i && options.exit_on_forward_failure) 1499 fatal("Could not request local forwarding."); 1500 if (i > 0 && success == 0) 1501 error("Could not request local forwarding."); 1502 1503 /* Initiate remote TCP/IP port forwardings. */ 1504 for (i = 0; i < options.num_remote_forwards; i++) { 1505 debug("Remote connections from %.200s:%d forwarded to " 1506 "local address %.200s:%d", 1507 (options.remote_forwards[i].listen_path != NULL) ? 1508 options.remote_forwards[i].listen_path : 1509 (options.remote_forwards[i].listen_host == NULL) ? 1510 "LOCALHOST" : options.remote_forwards[i].listen_host, 1511 options.remote_forwards[i].listen_port, 1512 (options.remote_forwards[i].connect_path != NULL) ? 1513 options.remote_forwards[i].connect_path : 1514 options.remote_forwards[i].connect_host, 1515 options.remote_forwards[i].connect_port); 1516 options.remote_forwards[i].handle = 1517 channel_request_remote_forwarding( 1518 &options.remote_forwards[i]); 1519 if (options.remote_forwards[i].handle < 0) { 1520 if (options.exit_on_forward_failure) 1521 fatal("Could not request remote forwarding."); 1522 else 1523 logit("Warning: Could not request remote " 1524 "forwarding."); 1525 } else { 1526 client_register_global_confirm(ssh_confirm_remote_forward, 1527 &options.remote_forwards[i]); 1528 } 1529 } 1530 1531 /* Initiate tunnel forwarding. */ 1532 if (options.tun_open != SSH_TUNMODE_NO) { 1533 if (client_request_tun_fwd(options.tun_open, 1534 options.tun_local, options.tun_remote) == -1) { 1535 if (options.exit_on_forward_failure) 1536 fatal("Could not request tunnel forwarding."); 1537 else 1538 error("Could not request tunnel forwarding."); 1539 } 1540 } 1541 } 1542 1543 static void 1544 check_agent_present(void) 1545 { 1546 int r; 1547 1548 if (options.forward_agent) { 1549 /* Clear agent forwarding if we don't have an agent. */ 1550 if ((r = ssh_get_authentication_socket(NULL)) != 0) { 1551 options.forward_agent = 0; 1552 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1553 debug("ssh_get_authentication_socket: %s", 1554 ssh_err(r)); 1555 } 1556 } 1557 } 1558 1559 static int 1560 ssh_session(void) 1561 { 1562 int type; 1563 int interactive = 0; 1564 int have_tty = 0; 1565 struct winsize ws; 1566 const char *display; 1567 1568 /* Enable compression if requested. */ 1569 if (options.compression) { 1570 debug("Requesting compression at level %d.", 1571 options.compression_level); 1572 1573 if (options.compression_level < 1 || 1574 options.compression_level > 9) 1575 fatal("Compression level must be from 1 (fast) to " 1576 "9 (slow, best)."); 1577 1578 /* Send the request. */ 1579 packet_start(SSH_CMSG_REQUEST_COMPRESSION); 1580 packet_put_int(options.compression_level); 1581 packet_send(); 1582 packet_write_wait(); 1583 type = packet_read(); 1584 if (type == SSH_SMSG_SUCCESS) 1585 packet_start_compression(options.compression_level); 1586 else if (type == SSH_SMSG_FAILURE) 1587 logit("Warning: Remote host refused compression."); 1588 else 1589 packet_disconnect("Protocol error waiting for " 1590 "compression response."); 1591 } 1592 /* Allocate a pseudo tty if appropriate. */ 1593 if (tty_flag) { 1594 const char *dp; 1595 debug("Requesting pty."); 1596 1597 /* Start the packet. */ 1598 packet_start(SSH_CMSG_REQUEST_PTY); 1599 1600 /* Store TERM in the packet. There is no limit on the 1601 length of the string. */ 1602 dp = getenv("TERM"); 1603 if (!dp) 1604 dp = ""; 1605 packet_put_cstring(dp); 1606 1607 /* Store window size in the packet. */ 1608 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 1609 memset(&ws, 0, sizeof(ws)); 1610 packet_put_int((u_int)ws.ws_row); 1611 packet_put_int((u_int)ws.ws_col); 1612 packet_put_int((u_int)ws.ws_xpixel); 1613 packet_put_int((u_int)ws.ws_ypixel); 1614 1615 /* Store tty modes in the packet. */ 1616 tty_make_modes(fileno(stdin), NULL); 1617 1618 /* Send the packet, and wait for it to leave. */ 1619 packet_send(); 1620 packet_write_wait(); 1621 1622 /* Read response from the server. */ 1623 type = packet_read(); 1624 if (type == SSH_SMSG_SUCCESS) { 1625 interactive = 1; 1626 have_tty = 1; 1627 } else if (type == SSH_SMSG_FAILURE) 1628 logit("Warning: Remote host failed or refused to " 1629 "allocate a pseudo tty."); 1630 else 1631 packet_disconnect("Protocol error waiting for pty " 1632 "request response."); 1633 } 1634 /* Request X11 forwarding if enabled and DISPLAY is set. */ 1635 display = getenv("DISPLAY"); 1636 if (display == NULL && options.forward_x11) 1637 debug("X11 forwarding requested but DISPLAY not set"); 1638 if (options.forward_x11 && display != NULL) { 1639 char *proto, *data; 1640 /* Get reasonable local authentication information. */ 1641 client_x11_get_proto(display, options.xauth_location, 1642 options.forward_x11_trusted, 1643 options.forward_x11_timeout, 1644 &proto, &data); 1645 /* Request forwarding with authentication spoofing. */ 1646 debug("Requesting X11 forwarding with authentication " 1647 "spoofing."); 1648 x11_request_forwarding_with_spoofing(0, display, proto, 1649 data, 0); 1650 /* Read response from the server. */ 1651 type = packet_read(); 1652 if (type == SSH_SMSG_SUCCESS) { 1653 interactive = 1; 1654 } else if (type == SSH_SMSG_FAILURE) { 1655 logit("Warning: Remote host denied X11 forwarding."); 1656 } else { 1657 packet_disconnect("Protocol error waiting for X11 " 1658 "forwarding"); 1659 } 1660 } 1661 /* Tell the packet module whether this is an interactive session. */ 1662 packet_set_interactive(interactive, 1663 options.ip_qos_interactive, options.ip_qos_bulk); 1664 1665 /* Request authentication agent forwarding if appropriate. */ 1666 check_agent_present(); 1667 1668 if (options.forward_agent) { 1669 debug("Requesting authentication agent forwarding."); 1670 auth_request_forwarding(); 1671 1672 /* Read response from the server. */ 1673 type = packet_read(); 1674 packet_check_eom(); 1675 if (type != SSH_SMSG_SUCCESS) 1676 logit("Warning: Remote host denied authentication agent forwarding."); 1677 } 1678 1679 /* Initiate port forwardings. */ 1680 ssh_init_stdio_forwarding(); 1681 ssh_init_forwarding(); 1682 1683 /* Execute a local command */ 1684 if (options.local_command != NULL && 1685 options.permit_local_command) 1686 ssh_local_cmd(options.local_command); 1687 1688 /* 1689 * If requested and we are not interested in replies to remote 1690 * forwarding requests, then let ssh continue in the background. 1691 */ 1692 if (fork_after_authentication_flag) { 1693 if (options.exit_on_forward_failure && 1694 options.num_remote_forwards > 0) { 1695 debug("deferring postauth fork until remote forward " 1696 "confirmation received"); 1697 } else 1698 fork_postauth(); 1699 } 1700 1701 /* 1702 * If a command was specified on the command line, execute the 1703 * command now. Otherwise request the server to start a shell. 1704 */ 1705 if (buffer_len(&command) > 0) { 1706 int len = buffer_len(&command); 1707 if (len > 900) 1708 len = 900; 1709 debug("Sending command: %.*s", len, 1710 (u_char *)buffer_ptr(&command)); 1711 packet_start(SSH_CMSG_EXEC_CMD); 1712 packet_put_string(buffer_ptr(&command), buffer_len(&command)); 1713 packet_send(); 1714 packet_write_wait(); 1715 } else { 1716 debug("Requesting shell."); 1717 packet_start(SSH_CMSG_EXEC_SHELL); 1718 packet_send(); 1719 packet_write_wait(); 1720 } 1721 1722 /* Enter the interactive session. */ 1723 return client_loop(have_tty, tty_flag ? 1724 options.escape_char : SSH_ESCAPECHAR_NONE, 0); 1725 } 1726 1727 /* request pty/x11/agent/tcpfwd/shell for channel */ 1728 static void 1729 ssh_session2_setup(int id, int success, void *arg) 1730 { 1731 extern char **environ; 1732 const char *display; 1733 int interactive = tty_flag; 1734 1735 if (!success) 1736 return; /* No need for error message, channels code sens one */ 1737 1738 display = getenv("DISPLAY"); 1739 if (display == NULL && options.forward_x11) 1740 debug("X11 forwarding requested but DISPLAY not set"); 1741 if (options.forward_x11 && display != NULL) { 1742 char *proto, *data; 1743 /* Get reasonable local authentication information. */ 1744 client_x11_get_proto(display, options.xauth_location, 1745 options.forward_x11_trusted, 1746 options.forward_x11_timeout, &proto, &data); 1747 /* Request forwarding with authentication spoofing. */ 1748 debug("Requesting X11 forwarding with authentication " 1749 "spoofing."); 1750 x11_request_forwarding_with_spoofing(id, display, proto, 1751 data, 1); 1752 client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN); 1753 /* XXX exit_on_forward_failure */ 1754 interactive = 1; 1755 } 1756 1757 check_agent_present(); 1758 if (options.forward_agent) { 1759 debug("Requesting authentication agent forwarding."); 1760 channel_request_start(id, "auth-agent-req@openssh.com", 0); 1761 packet_send(); 1762 } 1763 1764 /* Tell the packet module whether this is an interactive session. */ 1765 packet_set_interactive(interactive, 1766 options.ip_qos_interactive, options.ip_qos_bulk); 1767 1768 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), 1769 NULL, fileno(stdin), &command, environ); 1770 } 1771 1772 /* open new channel for a session */ 1773 static int 1774 ssh_session2_open(void) 1775 { 1776 Channel *c; 1777 int window, packetmax, in, out, err; 1778 int sock; 1779 int socksize; 1780 socklen_t socksizelen = sizeof(int); 1781 1782 if (stdin_null_flag) { 1783 in = open(_PATH_DEVNULL, O_RDONLY); 1784 } else { 1785 in = dup(STDIN_FILENO); 1786 } 1787 out = dup(STDOUT_FILENO); 1788 err = dup(STDERR_FILENO); 1789 1790 if (in < 0 || out < 0 || err < 0) 1791 fatal("dup() in/out/err failed"); 1792 1793 /* enable nonblocking unless tty */ 1794 if (!isatty(in)) 1795 set_nonblock(in); 1796 if (!isatty(out)) 1797 set_nonblock(out); 1798 if (!isatty(err)) 1799 set_nonblock(err); 1800 1801 /* we need to check to see if what they want to do about buffer */ 1802 /* sizes here. In a hpn to nonhpn connection we want to limit */ 1803 /* the window size to something reasonable in case the far side */ 1804 /* has the large window bug. In hpn to hpn connection we want to */ 1805 /* use the max window size but allow the user to override it */ 1806 /* lastly if they disabled hpn then use the ssh std window size */ 1807 1808 /* so why don't we just do a getsockopt() here and set the */ 1809 /* ssh window to that? In the case of a autotuning receive */ 1810 /* window the window would get stuck at the initial buffer */ 1811 /* size generally less than 96k. Therefore we need to set the */ 1812 /* maximum ssh window size to the maximum hpn buffer size */ 1813 /* unless the user has specifically set the tcprcvbufpoll */ 1814 /* to no. In which case we *can* just set the window to the */ 1815 /* minimum of the hpn buffer size and tcp receive buffer size */ 1816 1817 if (tty_flag) 1818 options.hpn_buffer_size = CHAN_SES_WINDOW_DEFAULT; 1819 else 1820 options.hpn_buffer_size = 2*1024*1024; 1821 1822 if (datafellows & SSH_BUG_LARGEWINDOW) 1823 { 1824 debug("HPN to Non-HPN Connection"); 1825 } 1826 else 1827 { 1828 if (options.tcp_rcv_buf_poll <= 0) 1829 { 1830 sock = socket(AF_INET, SOCK_STREAM, 0); 1831 getsockopt(sock, SOL_SOCKET, SO_RCVBUF, 1832 &socksize, &socksizelen); 1833 close(sock); 1834 debug("socksize %d", socksize); 1835 options.hpn_buffer_size = socksize; 1836 debug ("HPNBufferSize set to TCP RWIN: %d", options.hpn_buffer_size); 1837 } 1838 else 1839 { 1840 if (options.tcp_rcv_buf > 0) 1841 { 1842 /*create a socket but don't connect it */ 1843 /* we use that the get the rcv socket size */ 1844 sock = socket(AF_INET, SOCK_STREAM, 0); 1845 /* if they are using the tcp_rcv_buf option */ 1846 /* attempt to set the buffer size to that */ 1847 if (options.tcp_rcv_buf) 1848 setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void *)&options.tcp_rcv_buf, 1849 sizeof(options.tcp_rcv_buf)); 1850 getsockopt(sock, SOL_SOCKET, SO_RCVBUF, 1851 &socksize, &socksizelen); 1852 close(sock); 1853 debug("socksize %d", socksize); 1854 options.hpn_buffer_size = socksize; 1855 debug ("HPNBufferSize set to user TCPRcvBuf: %d", options.hpn_buffer_size); 1856 } 1857 } 1858 1859 } 1860 1861 debug("Final hpn_buffer_size = %d", options.hpn_buffer_size); 1862 1863 window = options.hpn_buffer_size; 1864 1865 channel_set_hpn(options.hpn_disabled, options.hpn_buffer_size); 1866 1867 packetmax = CHAN_SES_PACKET_DEFAULT; 1868 if (tty_flag) { 1869 window = 4*CHAN_SES_PACKET_DEFAULT; 1870 window >>= 1; 1871 packetmax >>= 1; 1872 } 1873 c = channel_new( 1874 "session", SSH_CHANNEL_OPENING, in, out, err, 1875 window, packetmax, CHAN_EXTENDED_WRITE, 1876 "client-session", /*nonblock*/0); 1877 1878 if ((options.tcp_rcv_buf_poll > 0) && (!options.hpn_disabled)) { 1879 c->dynamic_window = 1; 1880 debug ("Enabled Dynamic Window Scaling"); 1881 } 1882 debug3("ssh_session2_open: channel_new: %d", c->self); 1883 1884 channel_send_open(c->self); 1885 if (!no_shell_flag) 1886 channel_register_open_confirm(c->self, 1887 ssh_session2_setup, NULL); 1888 1889 return c->self; 1890 } 1891 1892 static int 1893 ssh_session2(void) 1894 { 1895 int id = -1; 1896 1897 /* XXX should be pre-session */ 1898 if (!options.control_persist) 1899 ssh_init_stdio_forwarding(); 1900 ssh_init_forwarding(); 1901 1902 /* Start listening for multiplex clients */ 1903 muxserver_listen(); 1904 1905 /* 1906 * If we are in control persist mode and have a working mux listen 1907 * socket, then prepare to background ourselves and have a foreground 1908 * client attach as a control slave. 1909 * NB. we must save copies of the flags that we override for 1910 * the backgrounding, since we defer attachment of the slave until 1911 * after the connection is fully established (in particular, 1912 * async rfwd replies have been received for ExitOnForwardFailure). 1913 */ 1914 if (options.control_persist && muxserver_sock != -1) { 1915 ostdin_null_flag = stdin_null_flag; 1916 ono_shell_flag = no_shell_flag; 1917 orequest_tty = options.request_tty; 1918 otty_flag = tty_flag; 1919 stdin_null_flag = 1; 1920 no_shell_flag = 1; 1921 tty_flag = 0; 1922 if (!fork_after_authentication_flag) 1923 need_controlpersist_detach = 1; 1924 fork_after_authentication_flag = 1; 1925 } 1926 /* 1927 * ControlPersist mux listen socket setup failed, attempt the 1928 * stdio forward setup that we skipped earlier. 1929 */ 1930 if (options.control_persist && muxserver_sock == -1) 1931 ssh_init_stdio_forwarding(); 1932 1933 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) 1934 id = ssh_session2_open(); 1935 else { 1936 packet_set_interactive( 1937 options.control_master == SSHCTL_MASTER_NO, 1938 options.ip_qos_interactive, options.ip_qos_bulk); 1939 } 1940 1941 /* If we don't expect to open a new session, then disallow it */ 1942 if (options.control_master == SSHCTL_MASTER_NO && 1943 (datafellows & SSH_NEW_OPENSSH)) { 1944 debug("Requesting no-more-sessions@openssh.com"); 1945 packet_start(SSH2_MSG_GLOBAL_REQUEST); 1946 packet_put_cstring("no-more-sessions@openssh.com"); 1947 packet_put_char(0); 1948 packet_send(); 1949 } 1950 1951 /* Execute a local command */ 1952 if (options.local_command != NULL && 1953 options.permit_local_command) 1954 ssh_local_cmd(options.local_command); 1955 1956 /* 1957 * If requested and we are not interested in replies to remote 1958 * forwarding requests, then let ssh continue in the background. 1959 */ 1960 if (fork_after_authentication_flag) { 1961 if (options.exit_on_forward_failure && 1962 options.num_remote_forwards > 0) { 1963 debug("deferring postauth fork until remote forward " 1964 "confirmation received"); 1965 } else 1966 fork_postauth(); 1967 } 1968 1969 if (options.use_roaming) 1970 request_roaming(); 1971 1972 return client_loop(tty_flag, tty_flag ? 1973 options.escape_char : SSH_ESCAPECHAR_NONE, id); 1974 } 1975 1976 static void 1977 load_public_identity_files(void) 1978 { 1979 char *filename, *cp, thishost[NI_MAXHOST]; 1980 char *pwdir = NULL, *pwname = NULL; 1981 int i = 0; 1982 Key *public; 1983 struct passwd *pw; 1984 u_int n_ids; 1985 char *identity_files[SSH_MAX_IDENTITY_FILES]; 1986 Key *identity_keys[SSH_MAX_IDENTITY_FILES]; 1987 #ifdef ENABLE_PKCS11 1988 Key **keys; 1989 int nkeys; 1990 #endif /* PKCS11 */ 1991 1992 n_ids = 0; 1993 memset(identity_files, 0, sizeof(identity_files)); 1994 memset(identity_keys, 0, sizeof(identity_keys)); 1995 1996 #ifdef ENABLE_PKCS11 1997 if (options.pkcs11_provider != NULL && 1998 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 1999 (pkcs11_init(!options.batch_mode) == 0) && 2000 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 2001 &keys)) > 0) { 2002 for (i = 0; i < nkeys; i++) { 2003 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 2004 key_free(keys[i]); 2005 continue; 2006 } 2007 identity_keys[n_ids] = keys[i]; 2008 identity_files[n_ids] = 2009 xstrdup(options.pkcs11_provider); /* XXX */ 2010 n_ids++; 2011 } 2012 free(keys); 2013 } 2014 #endif /* ENABLE_PKCS11 */ 2015 if ((pw = getpwuid(original_real_uid)) == NULL) 2016 fatal("load_public_identity_files: getpwuid failed"); 2017 pwname = xstrdup(pw->pw_name); 2018 pwdir = xstrdup(pw->pw_dir); 2019 if (gethostname(thishost, sizeof(thishost)) == -1) 2020 fatal("load_public_identity_files: gethostname: %s", 2021 strerror(errno)); 2022 for (i = 0; i < options.num_identity_files; i++) { 2023 if (n_ids >= SSH_MAX_IDENTITY_FILES || 2024 strcasecmp(options.identity_files[i], "none") == 0) { 2025 free(options.identity_files[i]); 2026 continue; 2027 } 2028 cp = tilde_expand_filename(options.identity_files[i], 2029 original_real_uid); 2030 filename = percent_expand(cp, "d", pwdir, 2031 "u", pwname, "l", thishost, "h", host, 2032 "r", options.user, (char *)NULL); 2033 free(cp); 2034 public = key_load_public(filename, NULL); 2035 debug("identity file %s type %d", filename, 2036 public ? public->type : -1); 2037 free(options.identity_files[i]); 2038 identity_files[n_ids] = filename; 2039 identity_keys[n_ids] = public; 2040 2041 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 2042 continue; 2043 2044 /* Try to add the certificate variant too */ 2045 xasprintf(&cp, "%s-cert", filename); 2046 public = key_load_public(cp, NULL); 2047 debug("identity file %s type %d", cp, 2048 public ? public->type : -1); 2049 if (public == NULL) { 2050 free(cp); 2051 continue; 2052 } 2053 if (!key_is_cert(public)) { 2054 debug("%s: key %s type %s is not a certificate", 2055 __func__, cp, key_type(public)); 2056 key_free(public); 2057 free(cp); 2058 continue; 2059 } 2060 identity_keys[n_ids] = public; 2061 /* point to the original path, most likely the private key */ 2062 identity_files[n_ids] = xstrdup(filename); 2063 n_ids++; 2064 } 2065 options.num_identity_files = n_ids; 2066 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 2067 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 2068 2069 explicit_bzero(pwname, strlen(pwname)); 2070 free(pwname); 2071 explicit_bzero(pwdir, strlen(pwdir)); 2072 free(pwdir); 2073 } 2074 2075 static void 2076 main_sigchld_handler(int sig) 2077 { 2078 int save_errno = errno; 2079 pid_t pid; 2080 int status; 2081 2082 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 2083 (pid < 0 && errno == EINTR)) 2084 ; 2085 2086 signal(sig, main_sigchld_handler); 2087 errno = save_errno; 2088 } 2089