1 /* $OpenBSD: ssh.c,v 1.294 2006/10/06 02:29:19 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * Ssh client program. This program can be used to log into a remote machine. 7 * The software supports strong authentication, encryption, and forwarding 8 * of X11, TCP/IP, and authentication connections. 9 * 10 * As far as I am concerned, the code I have written for this software 11 * can be used freely for any purpose. Any derived versions of this 12 * software must be clearly marked as such, and if the derived work is 13 * incompatible with the protocol description in the RFC file, it must be 14 * called by a name other than "ssh" or "Secure Shell". 15 * 16 * Copyright (c) 1999 Niels Provos. All rights reserved. 17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved. 18 * 19 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu> 20 * in Canada (German citizen). 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the above copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 41 */ 42 43 #include "includes.h" 44 __RCSID("$FreeBSD$"); 45 46 #include <sys/types.h> 47 #ifdef HAVE_SYS_STAT_H 48 # include <sys/stat.h> 49 #endif 50 #include <sys/resource.h> 51 #include <sys/ioctl.h> 52 #include <sys/socket.h> 53 #include <sys/un.h> 54 55 #include <ctype.h> 56 #include <errno.h> 57 #include <fcntl.h> 58 #include <netdb.h> 59 #ifdef HAVE_PATHS_H 60 #include <paths.h> 61 #endif 62 #include <pwd.h> 63 #include <signal.h> 64 #include <stdarg.h> 65 #include <stddef.h> 66 #include <stdio.h> 67 #include <stdlib.h> 68 #include <string.h> 69 #include <unistd.h> 70 71 #include <netinet/in.h> 72 #include <arpa/inet.h> 73 74 #include <openssl/evp.h> 75 #include <openssl/err.h> 76 77 #include "xmalloc.h" 78 #include "ssh.h" 79 #include "ssh1.h" 80 #include "ssh2.h" 81 #include "compat.h" 82 #include "cipher.h" 83 #include "packet.h" 84 #include "buffer.h" 85 #include "channels.h" 86 #include "key.h" 87 #include "authfd.h" 88 #include "authfile.h" 89 #include "pathnames.h" 90 #include "dispatch.h" 91 #include "clientloop.h" 92 #include "log.h" 93 #include "readconf.h" 94 #include "sshconnect.h" 95 #include "misc.h" 96 #include "kex.h" 97 #include "mac.h" 98 #include "sshpty.h" 99 #include "match.h" 100 #include "msg.h" 101 #include "monitor_fdpass.h" 102 #include "uidswap.h" 103 #include "version.h" 104 105 #ifdef SMARTCARD 106 #include "scard.h" 107 #endif 108 109 extern char *__progname; 110 111 /* Flag indicating whether debug mode is on. This can be set on the command line. */ 112 int debug_flag = 0; 113 114 /* Flag indicating whether a tty should be allocated */ 115 int tty_flag = 0; 116 int no_tty_flag = 0; 117 int force_tty_flag = 0; 118 119 /* don't exec a shell */ 120 int no_shell_flag = 0; 121 122 /* 123 * Flag indicating that nothing should be read from stdin. This can be set 124 * on the command line. 125 */ 126 int stdin_null_flag = 0; 127 128 /* 129 * Flag indicating that ssh should fork after authentication. This is useful 130 * so that the passphrase can be entered manually, and then ssh goes to the 131 * background. 132 */ 133 int fork_after_authentication_flag = 0; 134 135 /* 136 * General data structure for command line options and options configurable 137 * in configuration files. See readconf.h. 138 */ 139 Options options; 140 141 /* optional user configfile */ 142 char *config = NULL; 143 144 /* 145 * Name of the host we are connecting to. This is the name given on the 146 * command line, or the HostName specified for the user-supplied name in a 147 * configuration file. 148 */ 149 char *host; 150 151 /* socket address the host resolves to */ 152 struct sockaddr_storage hostaddr; 153 154 /* Private host keys. */ 155 Sensitive sensitive_data; 156 157 /* Original real UID. */ 158 uid_t original_real_uid; 159 uid_t original_effective_uid; 160 161 /* command to be executed */ 162 Buffer command; 163 164 /* Should we execute a command or invoke a subsystem? */ 165 int subsystem_flag = 0; 166 167 /* # of replies received for global requests */ 168 static int client_global_request_id = 0; 169 170 /* pid of proxycommand child process */ 171 pid_t proxy_command_pid = 0; 172 173 /* fd to control socket */ 174 int control_fd = -1; 175 176 /* Multiplexing control command */ 177 static u_int mux_command = 0; 178 179 /* Only used in control client mode */ 180 volatile sig_atomic_t control_client_terminate = 0; 181 u_int control_server_pid = 0; 182 183 /* Prints a help message to the user. This function never returns. */ 184 185 static void 186 usage(void) 187 { 188 fprintf(stderr, 189 "usage: ssh [-1246AaCfgkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n" 190 " [-D [bind_address:]port] [-e escape_char] [-F configfile]\n" 191 " [-i identity_file] [-L [bind_address:]port:host:hostport]\n" 192 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" 193 " [-R [bind_address:]port:host:hostport] [-S ctl_path]\n" 194 " [-w local_tun[:remote_tun]] [user@]hostname [command]\n" 195 ); 196 exit(255); 197 } 198 199 static int ssh_session(void); 200 static int ssh_session2(void); 201 static void load_public_identity_files(void); 202 static void control_client(const char *path); 203 204 /* 205 * Main program for the ssh client. 206 */ 207 int 208 main(int ac, char **av) 209 { 210 int i, opt, exit_status; 211 char *p, *cp, *line, buf[256]; 212 struct stat st; 213 struct passwd *pw; 214 int dummy; 215 extern int optind, optreset; 216 extern char *optarg; 217 struct servent *sp; 218 Forward fwd; 219 220 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 221 sanitise_stdfd(); 222 223 __progname = ssh_get_progname(av[0]); 224 init_rng(); 225 226 /* 227 * Save the original real uid. It will be needed later (uid-swapping 228 * may clobber the real uid). 229 */ 230 original_real_uid = getuid(); 231 original_effective_uid = geteuid(); 232 233 /* 234 * Use uid-swapping to give up root privileges for the duration of 235 * option processing. We will re-instantiate the rights when we are 236 * ready to create the privileged port, and will permanently drop 237 * them when the port has been created (actually, when the connection 238 * has been made, as we may need to create the port several times). 239 */ 240 PRIV_END; 241 242 #ifdef HAVE_SETRLIMIT 243 /* If we are installed setuid root be careful to not drop core. */ 244 if (original_real_uid != original_effective_uid) { 245 struct rlimit rlim; 246 rlim.rlim_cur = rlim.rlim_max = 0; 247 if (setrlimit(RLIMIT_CORE, &rlim) < 0) 248 fatal("setrlimit failed: %.100s", strerror(errno)); 249 } 250 #endif 251 /* Get user data. */ 252 pw = getpwuid(original_real_uid); 253 if (!pw) { 254 logit("You don't exist, go away!"); 255 exit(255); 256 } 257 /* Take a copy of the returned structure. */ 258 pw = pwcopy(pw); 259 260 /* 261 * Set our umask to something reasonable, as some files are created 262 * with the default umask. This will make them world-readable but 263 * writable only by the owner, which is ok for all files for which we 264 * don't set the modes explicitly. 265 */ 266 umask(022); 267 268 /* Initialize option structure to indicate that no values have been set. */ 269 initialize_options(&options); 270 271 /* Parse command-line arguments. */ 272 host = NULL; 273 274 again: 275 while ((opt = getopt(ac, av, 276 "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNO:PR:S:TVw:XY")) != -1) { 277 switch (opt) { 278 case '1': 279 options.protocol = SSH_PROTO_1; 280 break; 281 case '2': 282 options.protocol = SSH_PROTO_2; 283 break; 284 case '4': 285 options.address_family = AF_INET; 286 break; 287 case '6': 288 options.address_family = AF_INET6; 289 break; 290 case 'n': 291 stdin_null_flag = 1; 292 break; 293 case 'f': 294 fork_after_authentication_flag = 1; 295 stdin_null_flag = 1; 296 break; 297 case 'x': 298 options.forward_x11 = 0; 299 break; 300 case 'X': 301 options.forward_x11 = 1; 302 break; 303 case 'Y': 304 options.forward_x11 = 1; 305 options.forward_x11_trusted = 1; 306 break; 307 case 'g': 308 options.gateway_ports = 1; 309 break; 310 case 'O': 311 if (strcmp(optarg, "check") == 0) 312 mux_command = SSHMUX_COMMAND_ALIVE_CHECK; 313 else if (strcmp(optarg, "exit") == 0) 314 mux_command = SSHMUX_COMMAND_TERMINATE; 315 else 316 fatal("Invalid multiplex command."); 317 break; 318 case 'P': /* deprecated */ 319 options.use_privileged_port = 0; 320 break; 321 case 'a': 322 options.forward_agent = 0; 323 break; 324 case 'A': 325 options.forward_agent = 1; 326 break; 327 case 'k': 328 options.gss_deleg_creds = 0; 329 break; 330 case 'i': 331 if (stat(optarg, &st) < 0) { 332 fprintf(stderr, "Warning: Identity file %s " 333 "not accessible: %s.\n", optarg, 334 strerror(errno)); 335 break; 336 } 337 if (options.num_identity_files >= 338 SSH_MAX_IDENTITY_FILES) 339 fatal("Too many identity files specified " 340 "(max %d)", SSH_MAX_IDENTITY_FILES); 341 options.identity_files[options.num_identity_files++] = 342 xstrdup(optarg); 343 break; 344 case 'I': 345 #ifdef SMARTCARD 346 options.smartcard_device = xstrdup(optarg); 347 #else 348 fprintf(stderr, "no support for smartcards.\n"); 349 #endif 350 break; 351 case 't': 352 if (tty_flag) 353 force_tty_flag = 1; 354 tty_flag = 1; 355 break; 356 case 'v': 357 if (debug_flag == 0) { 358 debug_flag = 1; 359 options.log_level = SYSLOG_LEVEL_DEBUG1; 360 } else { 361 if (options.log_level < SYSLOG_LEVEL_DEBUG3) 362 options.log_level++; 363 break; 364 } 365 /* FALLTHROUGH */ 366 case 'V': 367 fprintf(stderr, "%s, %s\n", 368 SSH_RELEASE, SSLeay_version(SSLEAY_VERSION)); 369 if (opt == 'V') 370 exit(0); 371 break; 372 case 'w': 373 if (options.tun_open == -1) 374 options.tun_open = SSH_TUNMODE_DEFAULT; 375 options.tun_local = a2tun(optarg, &options.tun_remote); 376 if (options.tun_local == SSH_TUNID_ERR) { 377 fprintf(stderr, "Bad tun device '%s'\n", optarg); 378 exit(255); 379 } 380 break; 381 case 'q': 382 options.log_level = SYSLOG_LEVEL_QUIET; 383 break; 384 case 'e': 385 if (optarg[0] == '^' && optarg[2] == 0 && 386 (u_char) optarg[1] >= 64 && 387 (u_char) optarg[1] < 128) 388 options.escape_char = (u_char) optarg[1] & 31; 389 else if (strlen(optarg) == 1) 390 options.escape_char = (u_char) optarg[0]; 391 else if (strcmp(optarg, "none") == 0) 392 options.escape_char = SSH_ESCAPECHAR_NONE; 393 else { 394 fprintf(stderr, "Bad escape character '%s'.\n", 395 optarg); 396 exit(255); 397 } 398 break; 399 case 'c': 400 if (ciphers_valid(optarg)) { 401 /* SSH2 only */ 402 options.ciphers = xstrdup(optarg); 403 options.cipher = SSH_CIPHER_INVALID; 404 } else { 405 /* SSH1 only */ 406 options.cipher = cipher_number(optarg); 407 if (options.cipher == -1) { 408 fprintf(stderr, 409 "Unknown cipher type '%s'\n", 410 optarg); 411 exit(255); 412 } 413 if (options.cipher == SSH_CIPHER_3DES) 414 options.ciphers = "3des-cbc"; 415 else if (options.cipher == SSH_CIPHER_BLOWFISH) 416 options.ciphers = "blowfish-cbc"; 417 else 418 options.ciphers = (char *)-1; 419 } 420 break; 421 case 'm': 422 if (mac_valid(optarg)) 423 options.macs = xstrdup(optarg); 424 else { 425 fprintf(stderr, "Unknown mac type '%s'\n", 426 optarg); 427 exit(255); 428 } 429 break; 430 case 'M': 431 if (options.control_master == SSHCTL_MASTER_YES) 432 options.control_master = SSHCTL_MASTER_ASK; 433 else 434 options.control_master = SSHCTL_MASTER_YES; 435 break; 436 case 'p': 437 options.port = a2port(optarg); 438 if (options.port == 0) { 439 fprintf(stderr, "Bad port '%s'\n", optarg); 440 exit(255); 441 } 442 break; 443 case 'l': 444 options.user = optarg; 445 break; 446 447 case 'L': 448 if (parse_forward(&fwd, optarg)) 449 add_local_forward(&options, &fwd); 450 else { 451 fprintf(stderr, 452 "Bad local forwarding specification '%s'\n", 453 optarg); 454 exit(255); 455 } 456 break; 457 458 case 'R': 459 if (parse_forward(&fwd, optarg)) { 460 add_remote_forward(&options, &fwd); 461 } else { 462 fprintf(stderr, 463 "Bad remote forwarding specification " 464 "'%s'\n", optarg); 465 exit(255); 466 } 467 break; 468 469 case 'D': 470 cp = p = xstrdup(optarg); 471 memset(&fwd, '\0', sizeof(fwd)); 472 fwd.connect_host = "socks"; 473 if ((fwd.listen_host = hpdelim(&cp)) == NULL) { 474 fprintf(stderr, "Bad dynamic forwarding " 475 "specification '%.100s'\n", optarg); 476 exit(255); 477 } 478 if (cp != NULL) { 479 fwd.listen_port = a2port(cp); 480 fwd.listen_host = cleanhostname(fwd.listen_host); 481 } else { 482 fwd.listen_port = a2port(fwd.listen_host); 483 fwd.listen_host = NULL; 484 } 485 486 if (fwd.listen_port == 0) { 487 fprintf(stderr, "Bad dynamic port '%s'\n", 488 optarg); 489 exit(255); 490 } 491 add_local_forward(&options, &fwd); 492 xfree(p); 493 break; 494 495 case 'C': 496 options.compression = 1; 497 break; 498 case 'N': 499 no_shell_flag = 1; 500 no_tty_flag = 1; 501 break; 502 case 'T': 503 no_tty_flag = 1; 504 break; 505 case 'o': 506 dummy = 1; 507 line = xstrdup(optarg); 508 if (process_config_line(&options, host ? host : "", 509 line, "command-line", 0, &dummy) != 0) 510 exit(255); 511 xfree(line); 512 break; 513 case 's': 514 subsystem_flag = 1; 515 break; 516 case 'S': 517 if (options.control_path != NULL) 518 free(options.control_path); 519 options.control_path = xstrdup(optarg); 520 break; 521 case 'b': 522 options.bind_address = optarg; 523 break; 524 case 'F': 525 config = optarg; 526 break; 527 default: 528 usage(); 529 } 530 } 531 532 ac -= optind; 533 av += optind; 534 535 if (ac > 0 && !host && **av != '-') { 536 if (strrchr(*av, '@')) { 537 p = xstrdup(*av); 538 cp = strrchr(p, '@'); 539 if (cp == NULL || cp == p) 540 usage(); 541 options.user = p; 542 *cp = '\0'; 543 host = ++cp; 544 } else 545 host = *av; 546 if (ac > 1) { 547 optind = optreset = 1; 548 goto again; 549 } 550 ac--, av++; 551 } 552 553 /* Check that we got a host name. */ 554 if (!host) 555 usage(); 556 557 SSLeay_add_all_algorithms(); 558 ERR_load_crypto_strings(); 559 560 /* Initialize the command to execute on remote host. */ 561 buffer_init(&command); 562 563 /* 564 * Save the command to execute on the remote host in a buffer. There 565 * is no limit on the length of the command, except by the maximum 566 * packet size. Also sets the tty flag if there is no command. 567 */ 568 if (!ac) { 569 /* No command specified - execute shell on a tty. */ 570 tty_flag = 1; 571 if (subsystem_flag) { 572 fprintf(stderr, 573 "You must specify a subsystem to invoke.\n"); 574 usage(); 575 } 576 } else { 577 /* A command has been specified. Store it into the buffer. */ 578 for (i = 0; i < ac; i++) { 579 if (i) 580 buffer_append(&command, " ", 1); 581 buffer_append(&command, av[i], strlen(av[i])); 582 } 583 } 584 585 /* Cannot fork to background if no command. */ 586 if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag) 587 fatal("Cannot fork into background without a command to execute."); 588 589 /* Allocate a tty by default if no command specified. */ 590 if (buffer_len(&command) == 0) 591 tty_flag = 1; 592 593 /* Force no tty */ 594 if (no_tty_flag) 595 tty_flag = 0; 596 /* Do not allocate a tty if stdin is not a tty. */ 597 if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) { 598 if (tty_flag) 599 logit("Pseudo-terminal will not be allocated because stdin is not a terminal."); 600 tty_flag = 0; 601 } 602 603 /* 604 * Initialize "log" output. Since we are the client all output 605 * actually goes to stderr. 606 */ 607 log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, 608 SYSLOG_FACILITY_USER, 1); 609 610 /* 611 * Read per-user configuration file. Ignore the system wide config 612 * file if the user specifies a config file on the command line. 613 */ 614 if (config != NULL) { 615 if (!read_config_file(config, host, &options, 0)) 616 fatal("Can't open user config file %.100s: " 617 "%.100s", config, strerror(errno)); 618 } else { 619 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir, 620 _PATH_SSH_USER_CONFFILE); 621 (void)read_config_file(buf, host, &options, 1); 622 623 /* Read systemwide configuration file after use config. */ 624 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, 625 &options, 0); 626 } 627 628 /* Fill configuration defaults. */ 629 fill_default_options(&options); 630 631 channel_set_af(options.address_family); 632 633 /* reinit */ 634 log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1); 635 636 seed_rng(); 637 638 if (options.user == NULL) 639 options.user = xstrdup(pw->pw_name); 640 641 if (options.hostname != NULL) 642 host = options.hostname; 643 644 /* Find canonic host name. */ 645 if (strchr(host, '.') == 0) { 646 struct addrinfo hints; 647 struct addrinfo *ai = NULL; 648 int errgai; 649 memset(&hints, 0, sizeof(hints)); 650 hints.ai_family = options.address_family; 651 hints.ai_flags = AI_CANONNAME; 652 hints.ai_socktype = SOCK_STREAM; 653 errgai = getaddrinfo(host, NULL, &hints, &ai); 654 if (errgai == 0) { 655 if (ai->ai_canonname != NULL) 656 host = xstrdup(ai->ai_canonname); 657 freeaddrinfo(ai); 658 } 659 } 660 661 /* force lowercase for hostkey matching */ 662 if (options.host_key_alias != NULL) { 663 for (p = options.host_key_alias; *p; p++) 664 if (isupper(*p)) 665 *p = (char)tolower(*p); 666 } 667 668 /* Get default port if port has not been set. */ 669 if (options.port == 0) { 670 sp = getservbyname(SSH_SERVICE_NAME, "tcp"); 671 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT; 672 } 673 674 if (options.proxy_command != NULL && 675 strcmp(options.proxy_command, "none") == 0) 676 options.proxy_command = NULL; 677 if (options.control_path != NULL && 678 strcmp(options.control_path, "none") == 0) 679 options.control_path = NULL; 680 681 if (options.control_path != NULL) { 682 char thishost[NI_MAXHOST]; 683 684 if (gethostname(thishost, sizeof(thishost)) == -1) 685 fatal("gethostname: %s", strerror(errno)); 686 snprintf(buf, sizeof(buf), "%d", options.port); 687 cp = tilde_expand_filename(options.control_path, 688 original_real_uid); 689 options.control_path = percent_expand(cp, "p", buf, "h", host, 690 "r", options.user, "l", thishost, (char *)NULL); 691 xfree(cp); 692 } 693 if (mux_command != 0 && options.control_path == NULL) 694 fatal("No ControlPath specified for \"-O\" command"); 695 if (options.control_path != NULL) 696 control_client(options.control_path); 697 698 /* Open a connection to the remote host. */ 699 if (ssh_connect(host, &hostaddr, options.port, 700 options.address_family, options.connection_attempts, 701 #ifdef HAVE_CYGWIN 702 options.use_privileged_port, 703 #else 704 original_effective_uid == 0 && options.use_privileged_port, 705 #endif 706 options.proxy_command) != 0) 707 exit(255); 708 709 /* 710 * If we successfully made the connection, load the host private key 711 * in case we will need it later for combined rsa-rhosts 712 * authentication. This must be done before releasing extra 713 * privileges, because the file is only readable by root. 714 * If we cannot access the private keys, load the public keys 715 * instead and try to execute the ssh-keysign helper instead. 716 */ 717 sensitive_data.nkeys = 0; 718 sensitive_data.keys = NULL; 719 sensitive_data.external_keysign = 0; 720 if (options.rhosts_rsa_authentication || 721 options.hostbased_authentication) { 722 sensitive_data.nkeys = 3; 723 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 724 sizeof(Key)); 725 726 PRIV_START; 727 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, 728 _PATH_HOST_KEY_FILE, "", NULL, NULL); 729 sensitive_data.keys[1] = key_load_private_type(KEY_DSA, 730 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); 731 sensitive_data.keys[2] = key_load_private_type(KEY_RSA, 732 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); 733 PRIV_END; 734 735 if (options.hostbased_authentication == 1 && 736 sensitive_data.keys[0] == NULL && 737 sensitive_data.keys[1] == NULL && 738 sensitive_data.keys[2] == NULL) { 739 sensitive_data.keys[1] = key_load_public( 740 _PATH_HOST_DSA_KEY_FILE, NULL); 741 sensitive_data.keys[2] = key_load_public( 742 _PATH_HOST_RSA_KEY_FILE, NULL); 743 sensitive_data.external_keysign = 1; 744 } 745 } 746 /* 747 * Get rid of any extra privileges that we may have. We will no 748 * longer need them. Also, extra privileges could make it very hard 749 * to read identity files and other non-world-readable files from the 750 * user's home directory if it happens to be on a NFS volume where 751 * root is mapped to nobody. 752 */ 753 if (original_effective_uid == 0) { 754 PRIV_START; 755 permanently_set_uid(pw); 756 } 757 758 /* 759 * Now that we are back to our own permissions, create ~/.ssh 760 * directory if it doesn't already exist. 761 */ 762 snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 763 if (stat(buf, &st) < 0) 764 if (mkdir(buf, 0700) < 0) 765 error("Could not create directory '%.200s'.", buf); 766 767 /* load options.identity_files */ 768 load_public_identity_files(); 769 770 /* Expand ~ in known host file names. */ 771 /* XXX mem-leaks: */ 772 options.system_hostfile = 773 tilde_expand_filename(options.system_hostfile, original_real_uid); 774 options.user_hostfile = 775 tilde_expand_filename(options.user_hostfile, original_real_uid); 776 options.system_hostfile2 = 777 tilde_expand_filename(options.system_hostfile2, original_real_uid); 778 options.user_hostfile2 = 779 tilde_expand_filename(options.user_hostfile2, original_real_uid); 780 781 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 782 783 /* Log into the remote system. This never returns if the login fails. */ 784 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw); 785 786 /* We no longer need the private host keys. Clear them now. */ 787 if (sensitive_data.nkeys != 0) { 788 for (i = 0; i < sensitive_data.nkeys; i++) { 789 if (sensitive_data.keys[i] != NULL) { 790 /* Destroys contents safely */ 791 debug3("clear hostkey %d", i); 792 key_free(sensitive_data.keys[i]); 793 sensitive_data.keys[i] = NULL; 794 } 795 } 796 xfree(sensitive_data.keys); 797 } 798 for (i = 0; i < options.num_identity_files; i++) { 799 if (options.identity_files[i]) { 800 xfree(options.identity_files[i]); 801 options.identity_files[i] = NULL; 802 } 803 if (options.identity_keys[i]) { 804 key_free(options.identity_keys[i]); 805 options.identity_keys[i] = NULL; 806 } 807 } 808 809 exit_status = compat20 ? ssh_session2() : ssh_session(); 810 packet_close(); 811 812 if (options.control_path != NULL && control_fd != -1) 813 unlink(options.control_path); 814 815 /* 816 * Send SIGHUP to proxy command if used. We don't wait() in 817 * case it hangs and instead rely on init to reap the child 818 */ 819 if (proxy_command_pid > 1) 820 kill(proxy_command_pid, SIGHUP); 821 822 return exit_status; 823 } 824 825 static void 826 ssh_init_forwarding(void) 827 { 828 int success = 0; 829 int i; 830 831 /* Initiate local TCP/IP port forwardings. */ 832 for (i = 0; i < options.num_local_forwards; i++) { 833 debug("Local connections to %.200s:%d forwarded to remote " 834 "address %.200s:%d", 835 (options.local_forwards[i].listen_host == NULL) ? 836 (options.gateway_ports ? "*" : "LOCALHOST") : 837 options.local_forwards[i].listen_host, 838 options.local_forwards[i].listen_port, 839 options.local_forwards[i].connect_host, 840 options.local_forwards[i].connect_port); 841 success += channel_setup_local_fwd_listener( 842 options.local_forwards[i].listen_host, 843 options.local_forwards[i].listen_port, 844 options.local_forwards[i].connect_host, 845 options.local_forwards[i].connect_port, 846 options.gateway_ports); 847 } 848 if (i > 0 && success != i && options.exit_on_forward_failure) 849 fatal("Could not request local forwarding."); 850 if (i > 0 && success == 0) 851 error("Could not request local forwarding."); 852 853 /* Initiate remote TCP/IP port forwardings. */ 854 for (i = 0; i < options.num_remote_forwards; i++) { 855 debug("Remote connections from %.200s:%d forwarded to " 856 "local address %.200s:%d", 857 (options.remote_forwards[i].listen_host == NULL) ? 858 "LOCALHOST" : options.remote_forwards[i].listen_host, 859 options.remote_forwards[i].listen_port, 860 options.remote_forwards[i].connect_host, 861 options.remote_forwards[i].connect_port); 862 if (channel_request_remote_forwarding( 863 options.remote_forwards[i].listen_host, 864 options.remote_forwards[i].listen_port, 865 options.remote_forwards[i].connect_host, 866 options.remote_forwards[i].connect_port) < 0) { 867 if (options.exit_on_forward_failure) 868 fatal("Could not request remote forwarding."); 869 else 870 logit("Warning: Could not request remote " 871 "forwarding."); 872 } 873 } 874 } 875 876 static void 877 check_agent_present(void) 878 { 879 if (options.forward_agent) { 880 /* Clear agent forwarding if we don't have an agent. */ 881 if (!ssh_agent_present()) 882 options.forward_agent = 0; 883 } 884 } 885 886 static int 887 ssh_session(void) 888 { 889 int type; 890 int interactive = 0; 891 int have_tty = 0; 892 struct winsize ws; 893 char *cp; 894 const char *display; 895 896 /* Enable compression if requested. */ 897 if (options.compression) { 898 debug("Requesting compression at level %d.", options.compression_level); 899 900 if (options.compression_level < 1 || options.compression_level > 9) 901 fatal("Compression level must be from 1 (fast) to 9 (slow, best)."); 902 903 /* Send the request. */ 904 packet_start(SSH_CMSG_REQUEST_COMPRESSION); 905 packet_put_int(options.compression_level); 906 packet_send(); 907 packet_write_wait(); 908 type = packet_read(); 909 if (type == SSH_SMSG_SUCCESS) 910 packet_start_compression(options.compression_level); 911 else if (type == SSH_SMSG_FAILURE) 912 logit("Warning: Remote host refused compression."); 913 else 914 packet_disconnect("Protocol error waiting for compression response."); 915 } 916 /* Allocate a pseudo tty if appropriate. */ 917 if (tty_flag) { 918 debug("Requesting pty."); 919 920 /* Start the packet. */ 921 packet_start(SSH_CMSG_REQUEST_PTY); 922 923 /* Store TERM in the packet. There is no limit on the 924 length of the string. */ 925 cp = getenv("TERM"); 926 if (!cp) 927 cp = ""; 928 packet_put_cstring(cp); 929 930 /* Store window size in the packet. */ 931 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 932 memset(&ws, 0, sizeof(ws)); 933 packet_put_int((u_int)ws.ws_row); 934 packet_put_int((u_int)ws.ws_col); 935 packet_put_int((u_int)ws.ws_xpixel); 936 packet_put_int((u_int)ws.ws_ypixel); 937 938 /* Store tty modes in the packet. */ 939 tty_make_modes(fileno(stdin), NULL); 940 941 /* Send the packet, and wait for it to leave. */ 942 packet_send(); 943 packet_write_wait(); 944 945 /* Read response from the server. */ 946 type = packet_read(); 947 if (type == SSH_SMSG_SUCCESS) { 948 interactive = 1; 949 have_tty = 1; 950 } else if (type == SSH_SMSG_FAILURE) 951 logit("Warning: Remote host failed or refused to allocate a pseudo tty."); 952 else 953 packet_disconnect("Protocol error waiting for pty request response."); 954 } 955 /* Request X11 forwarding if enabled and DISPLAY is set. */ 956 display = getenv("DISPLAY"); 957 if (options.forward_x11 && display != NULL) { 958 char *proto, *data; 959 /* Get reasonable local authentication information. */ 960 client_x11_get_proto(display, options.xauth_location, 961 options.forward_x11_trusted, &proto, &data); 962 /* Request forwarding with authentication spoofing. */ 963 debug("Requesting X11 forwarding with authentication spoofing."); 964 x11_request_forwarding_with_spoofing(0, display, proto, data); 965 966 /* Read response from the server. */ 967 type = packet_read(); 968 if (type == SSH_SMSG_SUCCESS) { 969 interactive = 1; 970 } else if (type == SSH_SMSG_FAILURE) { 971 logit("Warning: Remote host denied X11 forwarding."); 972 } else { 973 packet_disconnect("Protocol error waiting for X11 forwarding"); 974 } 975 } 976 /* Tell the packet module whether this is an interactive session. */ 977 packet_set_interactive(interactive); 978 979 /* Request authentication agent forwarding if appropriate. */ 980 check_agent_present(); 981 982 if (options.forward_agent) { 983 debug("Requesting authentication agent forwarding."); 984 auth_request_forwarding(); 985 986 /* Read response from the server. */ 987 type = packet_read(); 988 packet_check_eom(); 989 if (type != SSH_SMSG_SUCCESS) 990 logit("Warning: Remote host denied authentication agent forwarding."); 991 } 992 993 /* Initiate port forwardings. */ 994 ssh_init_forwarding(); 995 996 /* If requested, let ssh continue in the background. */ 997 if (fork_after_authentication_flag) 998 if (daemon(1, 1) < 0) 999 fatal("daemon() failed: %.200s", strerror(errno)); 1000 1001 /* 1002 * If a command was specified on the command line, execute the 1003 * command now. Otherwise request the server to start a shell. 1004 */ 1005 if (buffer_len(&command) > 0) { 1006 int len = buffer_len(&command); 1007 if (len > 900) 1008 len = 900; 1009 debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command)); 1010 packet_start(SSH_CMSG_EXEC_CMD); 1011 packet_put_string(buffer_ptr(&command), buffer_len(&command)); 1012 packet_send(); 1013 packet_write_wait(); 1014 } else { 1015 debug("Requesting shell."); 1016 packet_start(SSH_CMSG_EXEC_SHELL); 1017 packet_send(); 1018 packet_write_wait(); 1019 } 1020 1021 /* Enter the interactive session. */ 1022 return client_loop(have_tty, tty_flag ? 1023 options.escape_char : SSH_ESCAPECHAR_NONE, 0); 1024 } 1025 1026 static void 1027 ssh_subsystem_reply(int type, u_int32_t seq, void *ctxt) 1028 { 1029 int id, len; 1030 1031 id = packet_get_int(); 1032 len = buffer_len(&command); 1033 if (len > 900) 1034 len = 900; 1035 packet_check_eom(); 1036 if (type == SSH2_MSG_CHANNEL_FAILURE) 1037 fatal("Request for subsystem '%.*s' failed on channel %d", 1038 len, (u_char *)buffer_ptr(&command), id); 1039 } 1040 1041 void 1042 client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt) 1043 { 1044 int i; 1045 1046 i = client_global_request_id++; 1047 if (i >= options.num_remote_forwards) 1048 return; 1049 debug("remote forward %s for: listen %d, connect %s:%d", 1050 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1051 options.remote_forwards[i].listen_port, 1052 options.remote_forwards[i].connect_host, 1053 options.remote_forwards[i].connect_port); 1054 if (type == SSH2_MSG_REQUEST_FAILURE) { 1055 if (options.exit_on_forward_failure) 1056 fatal("Error: remote port forwarding failed for " 1057 "listen port %d", 1058 options.remote_forwards[i].listen_port); 1059 else 1060 logit("Warning: remote port forwarding failed for " 1061 "listen port %d", 1062 options.remote_forwards[i].listen_port); 1063 } 1064 } 1065 1066 static void 1067 ssh_control_listener(void) 1068 { 1069 struct sockaddr_un addr; 1070 mode_t old_umask; 1071 int addr_len; 1072 1073 if (options.control_path == NULL || 1074 options.control_master == SSHCTL_MASTER_NO) 1075 return; 1076 1077 debug("setting up multiplex master socket"); 1078 1079 memset(&addr, '\0', sizeof(addr)); 1080 addr.sun_family = AF_UNIX; 1081 addr_len = offsetof(struct sockaddr_un, sun_path) + 1082 strlen(options.control_path) + 1; 1083 1084 if (strlcpy(addr.sun_path, options.control_path, 1085 sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) 1086 fatal("ControlPath too long"); 1087 1088 if ((control_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) 1089 fatal("%s socket(): %s", __func__, strerror(errno)); 1090 1091 old_umask = umask(0177); 1092 if (bind(control_fd, (struct sockaddr *)&addr, addr_len) == -1) { 1093 control_fd = -1; 1094 if (errno == EINVAL || errno == EADDRINUSE) 1095 fatal("ControlSocket %s already exists", 1096 options.control_path); 1097 else 1098 fatal("%s bind(): %s", __func__, strerror(errno)); 1099 } 1100 umask(old_umask); 1101 1102 if (listen(control_fd, 64) == -1) 1103 fatal("%s listen(): %s", __func__, strerror(errno)); 1104 1105 set_nonblock(control_fd); 1106 } 1107 1108 /* request pty/x11/agent/tcpfwd/shell for channel */ 1109 static void 1110 ssh_session2_setup(int id, void *arg) 1111 { 1112 extern char **environ; 1113 const char *display; 1114 int interactive = tty_flag; 1115 1116 display = getenv("DISPLAY"); 1117 if (options.forward_x11 && display != NULL) { 1118 char *proto, *data; 1119 /* Get reasonable local authentication information. */ 1120 client_x11_get_proto(display, options.xauth_location, 1121 options.forward_x11_trusted, &proto, &data); 1122 /* Request forwarding with authentication spoofing. */ 1123 debug("Requesting X11 forwarding with authentication spoofing."); 1124 x11_request_forwarding_with_spoofing(id, display, proto, data); 1125 interactive = 1; 1126 /* XXX wait for reply */ 1127 } 1128 1129 check_agent_present(); 1130 if (options.forward_agent) { 1131 debug("Requesting authentication agent forwarding."); 1132 channel_request_start(id, "auth-agent-req@openssh.com", 0); 1133 packet_send(); 1134 } 1135 1136 if (options.tun_open != SSH_TUNMODE_NO) { 1137 Channel *c; 1138 int fd; 1139 1140 debug("Requesting tun."); 1141 if ((fd = tun_open(options.tun_local, 1142 options.tun_open)) >= 0) { 1143 c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1, 1144 CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT, 1145 0, "tun", 1); 1146 c->datagram = 1; 1147 #if defined(SSH_TUN_FILTER) 1148 if (options.tun_open == SSH_TUNMODE_POINTOPOINT) 1149 channel_register_filter(c->self, sys_tun_infilter, 1150 sys_tun_outfilter); 1151 #endif 1152 packet_start(SSH2_MSG_CHANNEL_OPEN); 1153 packet_put_cstring("tun@openssh.com"); 1154 packet_put_int(c->self); 1155 packet_put_int(c->local_window_max); 1156 packet_put_int(c->local_maxpacket); 1157 packet_put_int(options.tun_open); 1158 packet_put_int(options.tun_remote); 1159 packet_send(); 1160 } 1161 } 1162 1163 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), 1164 NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply); 1165 1166 packet_set_interactive(interactive); 1167 } 1168 1169 /* open new channel for a session */ 1170 static int 1171 ssh_session2_open(void) 1172 { 1173 Channel *c; 1174 int window, packetmax, in, out, err; 1175 1176 if (stdin_null_flag) { 1177 in = open(_PATH_DEVNULL, O_RDONLY); 1178 } else { 1179 in = dup(STDIN_FILENO); 1180 } 1181 out = dup(STDOUT_FILENO); 1182 err = dup(STDERR_FILENO); 1183 1184 if (in < 0 || out < 0 || err < 0) 1185 fatal("dup() in/out/err failed"); 1186 1187 /* enable nonblocking unless tty */ 1188 if (!isatty(in)) 1189 set_nonblock(in); 1190 if (!isatty(out)) 1191 set_nonblock(out); 1192 if (!isatty(err)) 1193 set_nonblock(err); 1194 1195 window = CHAN_SES_WINDOW_DEFAULT; 1196 packetmax = CHAN_SES_PACKET_DEFAULT; 1197 if (tty_flag) { 1198 window >>= 1; 1199 packetmax >>= 1; 1200 } 1201 c = channel_new( 1202 "session", SSH_CHANNEL_OPENING, in, out, err, 1203 window, packetmax, CHAN_EXTENDED_WRITE, 1204 "client-session", /*nonblock*/0); 1205 1206 debug3("ssh_session2_open: channel_new: %d", c->self); 1207 1208 channel_send_open(c->self); 1209 if (!no_shell_flag) 1210 channel_register_confirm(c->self, ssh_session2_setup, NULL); 1211 1212 return c->self; 1213 } 1214 1215 static int 1216 ssh_session2(void) 1217 { 1218 int id = -1; 1219 1220 /* XXX should be pre-session */ 1221 ssh_init_forwarding(); 1222 ssh_control_listener(); 1223 1224 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) 1225 id = ssh_session2_open(); 1226 1227 /* Execute a local command */ 1228 if (options.local_command != NULL && 1229 options.permit_local_command) 1230 ssh_local_cmd(options.local_command); 1231 1232 /* If requested, let ssh continue in the background. */ 1233 if (fork_after_authentication_flag) 1234 if (daemon(1, 1) < 0) 1235 fatal("daemon() failed: %.200s", strerror(errno)); 1236 1237 return client_loop(tty_flag, tty_flag ? 1238 options.escape_char : SSH_ESCAPECHAR_NONE, id); 1239 } 1240 1241 static void 1242 load_public_identity_files(void) 1243 { 1244 char *filename, *cp, thishost[NI_MAXHOST]; 1245 int i = 0; 1246 Key *public; 1247 struct passwd *pw; 1248 #ifdef SMARTCARD 1249 Key **keys; 1250 1251 if (options.smartcard_device != NULL && 1252 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 1253 (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL) { 1254 int count = 0; 1255 for (i = 0; keys[i] != NULL; i++) { 1256 count++; 1257 memmove(&options.identity_files[1], &options.identity_files[0], 1258 sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1)); 1259 memmove(&options.identity_keys[1], &options.identity_keys[0], 1260 sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1)); 1261 options.num_identity_files++; 1262 options.identity_keys[0] = keys[i]; 1263 options.identity_files[0] = sc_get_key_label(keys[i]); 1264 } 1265 if (options.num_identity_files > SSH_MAX_IDENTITY_FILES) 1266 options.num_identity_files = SSH_MAX_IDENTITY_FILES; 1267 i = count; 1268 xfree(keys); 1269 } 1270 #endif /* SMARTCARD */ 1271 if ((pw = getpwuid(original_real_uid)) == NULL) 1272 fatal("load_public_identity_files: getpwuid failed"); 1273 if (gethostname(thishost, sizeof(thishost)) == -1) 1274 fatal("load_public_identity_files: gethostname: %s", 1275 strerror(errno)); 1276 for (; i < options.num_identity_files; i++) { 1277 cp = tilde_expand_filename(options.identity_files[i], 1278 original_real_uid); 1279 filename = percent_expand(cp, "d", pw->pw_dir, 1280 "u", pw->pw_name, "l", thishost, "h", host, 1281 "r", options.user, (char *)NULL); 1282 xfree(cp); 1283 public = key_load_public(filename, NULL); 1284 debug("identity file %s type %d", filename, 1285 public ? public->type : -1); 1286 xfree(options.identity_files[i]); 1287 options.identity_files[i] = filename; 1288 options.identity_keys[i] = public; 1289 } 1290 } 1291 1292 static void 1293 control_client_sighandler(int signo) 1294 { 1295 control_client_terminate = signo; 1296 } 1297 1298 static void 1299 control_client_sigrelay(int signo) 1300 { 1301 if (control_server_pid > 1) 1302 kill(control_server_pid, signo); 1303 } 1304 1305 static int 1306 env_permitted(char *env) 1307 { 1308 int i, ret; 1309 char name[1024], *cp; 1310 1311 if ((cp = strchr(env, '=')) == NULL || cp == env) 1312 return (0); 1313 ret = snprintf(name, sizeof(name), "%.*s", (int)(cp - env), env); 1314 if (ret <= 0 || (size_t)ret >= sizeof(name)) 1315 fatal("env_permitted: name '%.100s...' too long", env); 1316 1317 for (i = 0; i < options.num_send_env; i++) 1318 if (match_pattern(name, options.send_env[i])) 1319 return (1); 1320 1321 return (0); 1322 } 1323 1324 static void 1325 control_client(const char *path) 1326 { 1327 struct sockaddr_un addr; 1328 int i, r, fd, sock, exitval, num_env, addr_len; 1329 Buffer m; 1330 char *term; 1331 extern char **environ; 1332 u_int flags; 1333 1334 if (mux_command == 0) 1335 mux_command = SSHMUX_COMMAND_OPEN; 1336 1337 switch (options.control_master) { 1338 case SSHCTL_MASTER_AUTO: 1339 case SSHCTL_MASTER_AUTO_ASK: 1340 debug("auto-mux: Trying existing master"); 1341 /* FALLTHROUGH */ 1342 case SSHCTL_MASTER_NO: 1343 break; 1344 default: 1345 return; 1346 } 1347 1348 memset(&addr, '\0', sizeof(addr)); 1349 addr.sun_family = AF_UNIX; 1350 addr_len = offsetof(struct sockaddr_un, sun_path) + 1351 strlen(path) + 1; 1352 1353 if (strlcpy(addr.sun_path, path, 1354 sizeof(addr.sun_path)) >= sizeof(addr.sun_path)) 1355 fatal("ControlPath too long"); 1356 1357 if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0) 1358 fatal("%s socket(): %s", __func__, strerror(errno)); 1359 1360 if (connect(sock, (struct sockaddr *)&addr, addr_len) == -1) { 1361 if (mux_command != SSHMUX_COMMAND_OPEN) { 1362 fatal("Control socket connect(%.100s): %s", path, 1363 strerror(errno)); 1364 } 1365 if (errno == ENOENT) 1366 debug("Control socket \"%.100s\" does not exist", path); 1367 else { 1368 error("Control socket connect(%.100s): %s", path, 1369 strerror(errno)); 1370 } 1371 close(sock); 1372 return; 1373 } 1374 1375 if (stdin_null_flag) { 1376 if ((fd = open(_PATH_DEVNULL, O_RDONLY)) == -1) 1377 fatal("open(/dev/null): %s", strerror(errno)); 1378 if (dup2(fd, STDIN_FILENO) == -1) 1379 fatal("dup2: %s", strerror(errno)); 1380 if (fd > STDERR_FILENO) 1381 close(fd); 1382 } 1383 1384 term = getenv("TERM"); 1385 1386 flags = 0; 1387 if (tty_flag) 1388 flags |= SSHMUX_FLAG_TTY; 1389 if (subsystem_flag) 1390 flags |= SSHMUX_FLAG_SUBSYS; 1391 if (options.forward_x11) 1392 flags |= SSHMUX_FLAG_X11_FWD; 1393 if (options.forward_agent) 1394 flags |= SSHMUX_FLAG_AGENT_FWD; 1395 1396 buffer_init(&m); 1397 1398 /* Send our command to server */ 1399 buffer_put_int(&m, mux_command); 1400 buffer_put_int(&m, flags); 1401 if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) 1402 fatal("%s: msg_send", __func__); 1403 buffer_clear(&m); 1404 1405 /* Get authorisation status and PID of controlee */ 1406 if (ssh_msg_recv(sock, &m) == -1) 1407 fatal("%s: msg_recv", __func__); 1408 if (buffer_get_char(&m) != SSHMUX_VER) 1409 fatal("%s: wrong version", __func__); 1410 if (buffer_get_int(&m) != 1) 1411 fatal("Connection to master denied"); 1412 control_server_pid = buffer_get_int(&m); 1413 1414 buffer_clear(&m); 1415 1416 switch (mux_command) { 1417 case SSHMUX_COMMAND_ALIVE_CHECK: 1418 fprintf(stderr, "Master running (pid=%d)\r\n", 1419 control_server_pid); 1420 exit(0); 1421 case SSHMUX_COMMAND_TERMINATE: 1422 fprintf(stderr, "Exit request sent.\r\n"); 1423 exit(0); 1424 case SSHMUX_COMMAND_OPEN: 1425 /* continue below */ 1426 break; 1427 default: 1428 fatal("silly mux_command %d", mux_command); 1429 } 1430 1431 /* SSHMUX_COMMAND_OPEN */ 1432 buffer_put_cstring(&m, term ? term : ""); 1433 buffer_append(&command, "\0", 1); 1434 buffer_put_cstring(&m, buffer_ptr(&command)); 1435 1436 if (options.num_send_env == 0 || environ == NULL) { 1437 buffer_put_int(&m, 0); 1438 } else { 1439 /* Pass environment */ 1440 num_env = 0; 1441 for (i = 0; environ[i] != NULL; i++) 1442 if (env_permitted(environ[i])) 1443 num_env++; /* Count */ 1444 1445 buffer_put_int(&m, num_env); 1446 1447 for (i = 0; environ[i] != NULL && num_env >= 0; i++) 1448 if (env_permitted(environ[i])) { 1449 num_env--; 1450 buffer_put_cstring(&m, environ[i]); 1451 } 1452 } 1453 1454 if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1) 1455 fatal("%s: msg_send", __func__); 1456 1457 mm_send_fd(sock, STDIN_FILENO); 1458 mm_send_fd(sock, STDOUT_FILENO); 1459 mm_send_fd(sock, STDERR_FILENO); 1460 1461 /* Wait for reply, so master has a chance to gather ttymodes */ 1462 buffer_clear(&m); 1463 if (ssh_msg_recv(sock, &m) == -1) 1464 fatal("%s: msg_recv", __func__); 1465 if (buffer_get_char(&m) != SSHMUX_VER) 1466 fatal("%s: wrong version", __func__); 1467 buffer_free(&m); 1468 1469 signal(SIGHUP, control_client_sighandler); 1470 signal(SIGINT, control_client_sighandler); 1471 signal(SIGTERM, control_client_sighandler); 1472 signal(SIGWINCH, control_client_sigrelay); 1473 1474 if (tty_flag) 1475 enter_raw_mode(); 1476 1477 /* Stick around until the controlee closes the client_fd */ 1478 exitval = 0; 1479 for (;!control_client_terminate;) { 1480 r = read(sock, &exitval, sizeof(exitval)); 1481 if (r == 0) { 1482 debug2("Received EOF from master"); 1483 break; 1484 } 1485 if (r > 0) 1486 debug2("Received exit status from master %d", exitval); 1487 if (r == -1 && errno != EINTR) 1488 fatal("%s: read %s", __func__, strerror(errno)); 1489 } 1490 1491 if (control_client_terminate) 1492 debug2("Exiting on signal %d", control_client_terminate); 1493 1494 close(sock); 1495 1496 leave_raw_mode(); 1497 1498 if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET) 1499 fprintf(stderr, "Connection to master closed.\r\n"); 1500 1501 exit(exitval); 1502 } 1503