1 /* $OpenBSD: ssh.c,v 1.364 2011/08/02 23:15:03 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * Ssh client program. This program can be used to log into a remote machine. 7 * The software supports strong authentication, encryption, and forwarding 8 * of X11, TCP/IP, and authentication connections. 9 * 10 * As far as I am concerned, the code I have written for this software 11 * can be used freely for any purpose. Any derived versions of this 12 * software must be clearly marked as such, and if the derived work is 13 * incompatible with the protocol description in the RFC file, it must be 14 * called by a name other than "ssh" or "Secure Shell". 15 * 16 * Copyright (c) 1999 Niels Provos. All rights reserved. 17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved. 18 * 19 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu> 20 * in Canada (German citizen). 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the above copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 41 */ 42 43 #include "includes.h" 44 45 #include <sys/types.h> 46 #ifdef HAVE_SYS_STAT_H 47 # include <sys/stat.h> 48 #endif 49 #include <sys/resource.h> 50 #include <sys/ioctl.h> 51 #include <sys/param.h> 52 #include <sys/socket.h> 53 #include <sys/wait.h> 54 55 #include <ctype.h> 56 #include <errno.h> 57 #include <fcntl.h> 58 #include <netdb.h> 59 #ifdef HAVE_PATHS_H 60 #include <paths.h> 61 #endif 62 #include <pwd.h> 63 #include <signal.h> 64 #include <stdarg.h> 65 #include <stddef.h> 66 #include <stdio.h> 67 #include <stdlib.h> 68 #include <string.h> 69 #include <unistd.h> 70 71 #include <netinet/in.h> 72 #include <arpa/inet.h> 73 74 #include <openssl/evp.h> 75 #include <openssl/err.h> 76 #include "openbsd-compat/openssl-compat.h" 77 #include "openbsd-compat/sys-queue.h" 78 79 #include "xmalloc.h" 80 #include "ssh.h" 81 #include "ssh1.h" 82 #include "ssh2.h" 83 #include "canohost.h" 84 #include "compat.h" 85 #include "cipher.h" 86 #include "packet.h" 87 #include "buffer.h" 88 #include "channels.h" 89 #include "key.h" 90 #include "authfd.h" 91 #include "authfile.h" 92 #include "pathnames.h" 93 #include "dispatch.h" 94 #include "clientloop.h" 95 #include "log.h" 96 #include "readconf.h" 97 #include "sshconnect.h" 98 #include "misc.h" 99 #include "kex.h" 100 #include "mac.h" 101 #include "sshpty.h" 102 #include "match.h" 103 #include "msg.h" 104 #include "uidswap.h" 105 #include "roaming.h" 106 #include "version.h" 107 108 #ifdef ENABLE_PKCS11 109 #include "ssh-pkcs11.h" 110 #endif 111 112 extern char *__progname; 113 114 /* Saves a copy of argv for setproctitle emulation */ 115 #ifndef HAVE_SETPROCTITLE 116 static char **saved_av; 117 #endif 118 119 /* Flag indicating whether debug mode is on. May be set on the command line. */ 120 int debug_flag = 0; 121 122 /* Flag indicating whether a tty should be requested */ 123 int tty_flag = 0; 124 125 /* don't exec a shell */ 126 int no_shell_flag = 0; 127 128 /* 129 * Flag indicating that nothing should be read from stdin. This can be set 130 * on the command line. 131 */ 132 int stdin_null_flag = 0; 133 134 /* 135 * Flag indicating that the current process should be backgrounded and 136 * a new slave launched in the foreground for ControlPersist. 137 */ 138 int need_controlpersist_detach = 0; 139 140 /* Copies of flags for ControlPersist foreground slave */ 141 int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty; 142 143 /* 144 * Flag indicating that ssh should fork after authentication. This is useful 145 * so that the passphrase can be entered manually, and then ssh goes to the 146 * background. 147 */ 148 int fork_after_authentication_flag = 0; 149 150 /* forward stdio to remote host and port */ 151 char *stdio_forward_host = NULL; 152 int stdio_forward_port = 0; 153 154 /* 155 * General data structure for command line options and options configurable 156 * in configuration files. See readconf.h. 157 */ 158 Options options; 159 160 /* optional user configfile */ 161 char *config = NULL; 162 163 /* 164 * Name of the host we are connecting to. This is the name given on the 165 * command line, or the HostName specified for the user-supplied name in a 166 * configuration file. 167 */ 168 char *host; 169 170 /* socket address the host resolves to */ 171 struct sockaddr_storage hostaddr; 172 173 /* Private host keys. */ 174 Sensitive sensitive_data; 175 176 /* Original real UID. */ 177 uid_t original_real_uid; 178 uid_t original_effective_uid; 179 180 /* command to be executed */ 181 Buffer command; 182 183 /* Should we execute a command or invoke a subsystem? */ 184 int subsystem_flag = 0; 185 186 /* # of replies received for global requests */ 187 static int remote_forward_confirms_received = 0; 188 189 /* mux.c */ 190 extern int muxserver_sock; 191 extern u_int muxclient_command; 192 193 /* Prints a help message to the user. This function never returns. */ 194 195 static void 196 usage(void) 197 { 198 fprintf(stderr, 199 "usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n" 200 " [-D [bind_address:]port] [-e escape_char] [-F configfile]\n" 201 " [-I pkcs11] [-i identity_file]\n" 202 " [-L [bind_address:]port:host:hostport]\n" 203 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" 204 " [-R [bind_address:]port:host:hostport] [-S ctl_path]\n" 205 " [-W host:port] [-w local_tun[:remote_tun]]\n" 206 " [user@]hostname [command]\n" 207 ); 208 exit(255); 209 } 210 211 static int ssh_session(void); 212 static int ssh_session2(void); 213 static void load_public_identity_files(void); 214 static void main_sigchld_handler(int); 215 216 /* from muxclient.c */ 217 void muxclient(const char *); 218 void muxserver_listen(void); 219 220 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 221 static void 222 tilde_expand_paths(char **paths, u_int num_paths) 223 { 224 u_int i; 225 char *cp; 226 227 for (i = 0; i < num_paths; i++) { 228 cp = tilde_expand_filename(paths[i], original_real_uid); 229 xfree(paths[i]); 230 paths[i] = cp; 231 } 232 } 233 234 /* 235 * Main program for the ssh client. 236 */ 237 int 238 main(int ac, char **av) 239 { 240 int i, r, opt, exit_status, use_syslog; 241 char *p, *cp, *line, *argv0, buf[MAXPATHLEN], *host_arg; 242 char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 243 struct stat st; 244 struct passwd *pw; 245 int dummy, timeout_ms; 246 extern int optind, optreset; 247 extern char *optarg; 248 249 struct servent *sp; 250 Forward fwd; 251 252 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 253 sanitise_stdfd(); 254 255 __progname = ssh_get_progname(av[0]); 256 257 #ifndef HAVE_SETPROCTITLE 258 /* Prepare for later setproctitle emulation */ 259 /* Save argv so it isn't clobbered by setproctitle() emulation */ 260 saved_av = xcalloc(ac + 1, sizeof(*saved_av)); 261 for (i = 0; i < ac; i++) 262 saved_av[i] = xstrdup(av[i]); 263 saved_av[i] = NULL; 264 compat_init_setproctitle(ac, av); 265 av = saved_av; 266 #endif 267 268 /* 269 * Discard other fds that are hanging around. These can cause problem 270 * with backgrounded ssh processes started by ControlPersist. 271 */ 272 closefrom(STDERR_FILENO + 1); 273 274 /* 275 * Save the original real uid. It will be needed later (uid-swapping 276 * may clobber the real uid). 277 */ 278 original_real_uid = getuid(); 279 original_effective_uid = geteuid(); 280 281 /* 282 * Use uid-swapping to give up root privileges for the duration of 283 * option processing. We will re-instantiate the rights when we are 284 * ready to create the privileged port, and will permanently drop 285 * them when the port has been created (actually, when the connection 286 * has been made, as we may need to create the port several times). 287 */ 288 PRIV_END; 289 290 #ifdef HAVE_SETRLIMIT 291 /* If we are installed setuid root be careful to not drop core. */ 292 if (original_real_uid != original_effective_uid) { 293 struct rlimit rlim; 294 rlim.rlim_cur = rlim.rlim_max = 0; 295 if (setrlimit(RLIMIT_CORE, &rlim) < 0) 296 fatal("setrlimit failed: %.100s", strerror(errno)); 297 } 298 #endif 299 /* Get user data. */ 300 pw = getpwuid(original_real_uid); 301 if (!pw) { 302 logit("You don't exist, go away!"); 303 exit(255); 304 } 305 /* Take a copy of the returned structure. */ 306 pw = pwcopy(pw); 307 308 /* 309 * Set our umask to something reasonable, as some files are created 310 * with the default umask. This will make them world-readable but 311 * writable only by the owner, which is ok for all files for which we 312 * don't set the modes explicitly. 313 */ 314 umask(022); 315 316 /* 317 * Initialize option structure to indicate that no values have been 318 * set. 319 */ 320 initialize_options(&options); 321 322 /* Parse command-line arguments. */ 323 host = NULL; 324 use_syslog = 0; 325 argv0 = av[0]; 326 327 again: 328 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 329 "ACD:F:I:KL:MNO:PR:S:TVw:W:XYy")) != -1) { 330 switch (opt) { 331 case '1': 332 options.protocol = SSH_PROTO_1; 333 break; 334 case '2': 335 options.protocol = SSH_PROTO_2; 336 break; 337 case '4': 338 options.address_family = AF_INET; 339 break; 340 case '6': 341 options.address_family = AF_INET6; 342 break; 343 case 'n': 344 stdin_null_flag = 1; 345 break; 346 case 'f': 347 fork_after_authentication_flag = 1; 348 stdin_null_flag = 1; 349 break; 350 case 'x': 351 options.forward_x11 = 0; 352 break; 353 case 'X': 354 options.forward_x11 = 1; 355 break; 356 case 'y': 357 use_syslog = 1; 358 break; 359 case 'Y': 360 options.forward_x11 = 1; 361 options.forward_x11_trusted = 1; 362 break; 363 case 'g': 364 options.gateway_ports = 1; 365 break; 366 case 'O': 367 if (stdio_forward_host != NULL) 368 fatal("Cannot specify multiplexing " 369 "command with -W"); 370 else if (muxclient_command != 0) 371 fatal("Multiplexing command already specified"); 372 if (strcmp(optarg, "check") == 0) 373 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 374 else if (strcmp(optarg, "forward") == 0) 375 muxclient_command = SSHMUX_COMMAND_FORWARD; 376 else if (strcmp(optarg, "exit") == 0) 377 muxclient_command = SSHMUX_COMMAND_TERMINATE; 378 else if (strcmp(optarg, "stop") == 0) 379 muxclient_command = SSHMUX_COMMAND_STOP; 380 else 381 fatal("Invalid multiplex command."); 382 break; 383 case 'P': /* deprecated */ 384 options.use_privileged_port = 0; 385 break; 386 case 'a': 387 options.forward_agent = 0; 388 break; 389 case 'A': 390 options.forward_agent = 1; 391 break; 392 case 'k': 393 options.gss_deleg_creds = 0; 394 break; 395 case 'K': 396 options.gss_authentication = 1; 397 options.gss_deleg_creds = 1; 398 break; 399 case 'i': 400 if (stat(optarg, &st) < 0) { 401 fprintf(stderr, "Warning: Identity file %s " 402 "not accessible: %s.\n", optarg, 403 strerror(errno)); 404 break; 405 } 406 if (options.num_identity_files >= 407 SSH_MAX_IDENTITY_FILES) 408 fatal("Too many identity files specified " 409 "(max %d)", SSH_MAX_IDENTITY_FILES); 410 options.identity_files[options.num_identity_files++] = 411 xstrdup(optarg); 412 break; 413 case 'I': 414 #ifdef ENABLE_PKCS11 415 options.pkcs11_provider = xstrdup(optarg); 416 #else 417 fprintf(stderr, "no support for PKCS#11.\n"); 418 #endif 419 break; 420 case 't': 421 if (options.request_tty == REQUEST_TTY_YES) 422 options.request_tty = REQUEST_TTY_FORCE; 423 else 424 options.request_tty = REQUEST_TTY_YES; 425 break; 426 case 'v': 427 if (debug_flag == 0) { 428 debug_flag = 1; 429 options.log_level = SYSLOG_LEVEL_DEBUG1; 430 } else { 431 if (options.log_level < SYSLOG_LEVEL_DEBUG3) 432 options.log_level++; 433 break; 434 } 435 /* FALLTHROUGH */ 436 case 'V': 437 fprintf(stderr, "%s, %s\n", 438 SSH_RELEASE, SSLeay_version(SSLEAY_VERSION)); 439 if (opt == 'V') 440 exit(0); 441 break; 442 case 'w': 443 if (options.tun_open == -1) 444 options.tun_open = SSH_TUNMODE_DEFAULT; 445 options.tun_local = a2tun(optarg, &options.tun_remote); 446 if (options.tun_local == SSH_TUNID_ERR) { 447 fprintf(stderr, 448 "Bad tun device '%s'\n", optarg); 449 exit(255); 450 } 451 break; 452 case 'W': 453 if (stdio_forward_host != NULL) 454 fatal("stdio forward already specified"); 455 if (muxclient_command != 0) 456 fatal("Cannot specify stdio forward with -O"); 457 if (parse_forward(&fwd, optarg, 1, 0)) { 458 stdio_forward_host = fwd.listen_host; 459 stdio_forward_port = fwd.listen_port; 460 xfree(fwd.connect_host); 461 } else { 462 fprintf(stderr, 463 "Bad stdio forwarding specification '%s'\n", 464 optarg); 465 exit(255); 466 } 467 options.request_tty = REQUEST_TTY_NO; 468 no_shell_flag = 1; 469 options.clear_forwardings = 1; 470 options.exit_on_forward_failure = 1; 471 break; 472 case 'q': 473 options.log_level = SYSLOG_LEVEL_QUIET; 474 break; 475 case 'e': 476 if (optarg[0] == '^' && optarg[2] == 0 && 477 (u_char) optarg[1] >= 64 && 478 (u_char) optarg[1] < 128) 479 options.escape_char = (u_char) optarg[1] & 31; 480 else if (strlen(optarg) == 1) 481 options.escape_char = (u_char) optarg[0]; 482 else if (strcmp(optarg, "none") == 0) 483 options.escape_char = SSH_ESCAPECHAR_NONE; 484 else { 485 fprintf(stderr, "Bad escape character '%s'.\n", 486 optarg); 487 exit(255); 488 } 489 break; 490 case 'c': 491 if (ciphers_valid(optarg)) { 492 /* SSH2 only */ 493 options.ciphers = xstrdup(optarg); 494 options.cipher = SSH_CIPHER_INVALID; 495 } else { 496 /* SSH1 only */ 497 options.cipher = cipher_number(optarg); 498 if (options.cipher == -1) { 499 fprintf(stderr, 500 "Unknown cipher type '%s'\n", 501 optarg); 502 exit(255); 503 } 504 if (options.cipher == SSH_CIPHER_3DES) 505 options.ciphers = "3des-cbc"; 506 else if (options.cipher == SSH_CIPHER_BLOWFISH) 507 options.ciphers = "blowfish-cbc"; 508 else 509 options.ciphers = (char *)-1; 510 } 511 break; 512 case 'm': 513 if (mac_valid(optarg)) 514 options.macs = xstrdup(optarg); 515 else { 516 fprintf(stderr, "Unknown mac type '%s'\n", 517 optarg); 518 exit(255); 519 } 520 break; 521 case 'M': 522 if (options.control_master == SSHCTL_MASTER_YES) 523 options.control_master = SSHCTL_MASTER_ASK; 524 else 525 options.control_master = SSHCTL_MASTER_YES; 526 break; 527 case 'p': 528 options.port = a2port(optarg); 529 if (options.port <= 0) { 530 fprintf(stderr, "Bad port '%s'\n", optarg); 531 exit(255); 532 } 533 break; 534 case 'l': 535 options.user = optarg; 536 break; 537 538 case 'L': 539 if (parse_forward(&fwd, optarg, 0, 0)) 540 add_local_forward(&options, &fwd); 541 else { 542 fprintf(stderr, 543 "Bad local forwarding specification '%s'\n", 544 optarg); 545 exit(255); 546 } 547 break; 548 549 case 'R': 550 if (parse_forward(&fwd, optarg, 0, 1)) { 551 add_remote_forward(&options, &fwd); 552 } else { 553 fprintf(stderr, 554 "Bad remote forwarding specification " 555 "'%s'\n", optarg); 556 exit(255); 557 } 558 break; 559 560 case 'D': 561 if (parse_forward(&fwd, optarg, 1, 0)) { 562 add_local_forward(&options, &fwd); 563 } else { 564 fprintf(stderr, 565 "Bad dynamic forwarding specification " 566 "'%s'\n", optarg); 567 exit(255); 568 } 569 break; 570 571 case 'C': 572 options.compression = 1; 573 break; 574 case 'N': 575 no_shell_flag = 1; 576 options.request_tty = REQUEST_TTY_NO; 577 break; 578 case 'T': 579 options.request_tty = REQUEST_TTY_NO; 580 /* ensure that the user doesn't try to backdoor a */ 581 /* null cipher switch on an interactive session */ 582 /* so explicitly disable it no matter what */ 583 options.none_switch=0; 584 break; 585 case 'o': 586 dummy = 1; 587 line = xstrdup(optarg); 588 if (process_config_line(&options, host ? host : "", 589 line, "command-line", 0, &dummy) != 0) 590 exit(255); 591 xfree(line); 592 break; 593 case 's': 594 subsystem_flag = 1; 595 break; 596 case 'S': 597 if (options.control_path != NULL) 598 free(options.control_path); 599 options.control_path = xstrdup(optarg); 600 break; 601 case 'b': 602 options.bind_address = optarg; 603 break; 604 case 'F': 605 config = optarg; 606 break; 607 default: 608 usage(); 609 } 610 } 611 612 ac -= optind; 613 av += optind; 614 615 if (ac > 0 && !host) { 616 if (strrchr(*av, '@')) { 617 p = xstrdup(*av); 618 cp = strrchr(p, '@'); 619 if (cp == NULL || cp == p) 620 usage(); 621 options.user = p; 622 *cp = '\0'; 623 host = ++cp; 624 } else 625 host = *av; 626 if (ac > 1) { 627 optind = optreset = 1; 628 goto again; 629 } 630 ac--, av++; 631 } 632 633 /* Check that we got a host name. */ 634 if (!host) 635 usage(); 636 637 OpenSSL_add_all_algorithms(); 638 ERR_load_crypto_strings(); 639 640 /* Initialize the command to execute on remote host. */ 641 buffer_init(&command); 642 643 if (options.request_tty == REQUEST_TTY_YES || 644 options.request_tty == REQUEST_TTY_FORCE) 645 tty_flag = 1; 646 647 /* 648 * Save the command to execute on the remote host in a buffer. There 649 * is no limit on the length of the command, except by the maximum 650 * packet size. Also sets the tty flag if there is no command. 651 */ 652 if (!ac) { 653 /* No command specified - execute shell on a tty. */ 654 tty_flag = options.request_tty != REQUEST_TTY_NO; 655 if (subsystem_flag) { 656 fprintf(stderr, 657 "You must specify a subsystem to invoke.\n"); 658 usage(); 659 } 660 } else { 661 /* A command has been specified. Store it into the buffer. */ 662 for (i = 0; i < ac; i++) { 663 if (i) 664 buffer_append(&command, " ", 1); 665 buffer_append(&command, av[i], strlen(av[i])); 666 } 667 } 668 669 /* Cannot fork to background if no command. */ 670 if (fork_after_authentication_flag && buffer_len(&command) == 0 && 671 !no_shell_flag) 672 fatal("Cannot fork into background without a command " 673 "to execute."); 674 675 /* Allocate a tty by default if no command specified. */ 676 if (buffer_len(&command) == 0) 677 tty_flag = options.request_tty != REQUEST_TTY_NO; 678 679 /* Force no tty */ 680 if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0) 681 tty_flag = 0; 682 /* Do not allocate a tty if stdin is not a tty. */ 683 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 684 options.request_tty != REQUEST_TTY_FORCE) { 685 if (tty_flag) 686 logit("Pseudo-terminal will not be allocated because " 687 "stdin is not a terminal."); 688 tty_flag = 0; 689 } 690 691 /* 692 * Initialize "log" output. Since we are the client all output 693 * actually goes to stderr. 694 */ 695 log_init(argv0, 696 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, 697 SYSLOG_FACILITY_USER, !use_syslog); 698 699 /* 700 * Read per-user configuration file. Ignore the system wide config 701 * file if the user specifies a config file on the command line. 702 */ 703 if (config != NULL) { 704 if (!read_config_file(config, host, &options, 0)) 705 fatal("Can't open user config file %.100s: " 706 "%.100s", config, strerror(errno)); 707 } else { 708 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 709 _PATH_SSH_USER_CONFFILE); 710 if (r > 0 && (size_t)r < sizeof(buf)) 711 (void)read_config_file(buf, host, &options, 1); 712 713 /* Read systemwide configuration file after user config. */ 714 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, 715 &options, 0); 716 } 717 718 /* Fill configuration defaults. */ 719 fill_default_options(&options); 720 721 channel_set_af(options.address_family); 722 723 /* reinit */ 724 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog); 725 726 seed_rng(); 727 728 if (options.user == NULL) 729 options.user = xstrdup(pw->pw_name); 730 731 /* Get default port if port has not been set. */ 732 if (options.port == 0) { 733 sp = getservbyname(SSH_SERVICE_NAME, "tcp"); 734 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT; 735 } 736 737 /* preserve host name given on command line for %n expansion */ 738 host_arg = host; 739 if (options.hostname != NULL) { 740 host = percent_expand(options.hostname, 741 "h", host, (char *)NULL); 742 } 743 744 if (gethostname(thishost, sizeof(thishost)) == -1) 745 fatal("gethostname: %s", strerror(errno)); 746 strlcpy(shorthost, thishost, sizeof(shorthost)); 747 shorthost[strcspn(thishost, ".")] = '\0'; 748 snprintf(portstr, sizeof(portstr), "%d", options.port); 749 750 if (options.local_command != NULL) { 751 debug3("expanding LocalCommand: %s", options.local_command); 752 cp = options.local_command; 753 options.local_command = percent_expand(cp, "d", pw->pw_dir, 754 "h", host, "l", thishost, "n", host_arg, "r", options.user, 755 "p", portstr, "u", pw->pw_name, "L", shorthost, 756 (char *)NULL); 757 debug3("expanded LocalCommand: %s", options.local_command); 758 xfree(cp); 759 } 760 761 /* force lowercase for hostkey matching */ 762 if (options.host_key_alias != NULL) { 763 for (p = options.host_key_alias; *p; p++) 764 if (isupper(*p)) 765 *p = (char)tolower(*p); 766 } 767 768 if (options.proxy_command != NULL && 769 strcmp(options.proxy_command, "none") == 0) { 770 xfree(options.proxy_command); 771 options.proxy_command = NULL; 772 } 773 if (options.control_path != NULL && 774 strcmp(options.control_path, "none") == 0) { 775 xfree(options.control_path); 776 options.control_path = NULL; 777 } 778 779 if (options.control_path != NULL) { 780 cp = tilde_expand_filename(options.control_path, 781 original_real_uid); 782 xfree(options.control_path); 783 options.control_path = percent_expand(cp, "h", host, 784 "l", thishost, "n", host_arg, "r", options.user, 785 "p", portstr, "u", pw->pw_name, "L", shorthost, 786 (char *)NULL); 787 xfree(cp); 788 } 789 if (muxclient_command != 0 && options.control_path == NULL) 790 fatal("No ControlPath specified for \"-O\" command"); 791 if (options.control_path != NULL) 792 muxclient(options.control_path); 793 794 timeout_ms = options.connection_timeout * 1000; 795 796 /* Open a connection to the remote host. */ 797 if (ssh_connect(host, &hostaddr, options.port, 798 options.address_family, options.connection_attempts, &timeout_ms, 799 options.tcp_keep_alive, 800 #ifdef HAVE_CYGWIN 801 options.use_privileged_port, 802 #else 803 original_effective_uid == 0 && options.use_privileged_port, 804 #endif 805 options.proxy_command) != 0) 806 exit(255); 807 808 if (timeout_ms > 0) 809 debug3("timeout: %d ms remain after connect", timeout_ms); 810 811 /* 812 * If we successfully made the connection, load the host private key 813 * in case we will need it later for combined rsa-rhosts 814 * authentication. This must be done before releasing extra 815 * privileges, because the file is only readable by root. 816 * If we cannot access the private keys, load the public keys 817 * instead and try to execute the ssh-keysign helper instead. 818 */ 819 sensitive_data.nkeys = 0; 820 sensitive_data.keys = NULL; 821 sensitive_data.external_keysign = 0; 822 if (options.rhosts_rsa_authentication || 823 options.hostbased_authentication) { 824 sensitive_data.nkeys = 7; 825 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 826 sizeof(Key)); 827 for (i = 0; i < sensitive_data.nkeys; i++) 828 sensitive_data.keys[i] = NULL; 829 830 PRIV_START; 831 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, 832 _PATH_HOST_KEY_FILE, "", NULL, NULL); 833 sensitive_data.keys[1] = key_load_private_cert(KEY_DSA, 834 _PATH_HOST_DSA_KEY_FILE, "", NULL); 835 #ifdef OPENSSL_HAS_ECC 836 sensitive_data.keys[2] = key_load_private_cert(KEY_ECDSA, 837 _PATH_HOST_ECDSA_KEY_FILE, "", NULL); 838 #endif 839 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA, 840 _PATH_HOST_RSA_KEY_FILE, "", NULL); 841 sensitive_data.keys[4] = key_load_private_type(KEY_DSA, 842 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); 843 #ifdef OPENSSL_HAS_ECC 844 sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA, 845 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL); 846 #endif 847 sensitive_data.keys[6] = key_load_private_type(KEY_RSA, 848 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); 849 PRIV_END; 850 851 if (options.hostbased_authentication == 1 && 852 sensitive_data.keys[0] == NULL && 853 sensitive_data.keys[4] == NULL && 854 sensitive_data.keys[5] == NULL && 855 sensitive_data.keys[6] == NULL) { 856 sensitive_data.keys[1] = key_load_cert( 857 _PATH_HOST_DSA_KEY_FILE); 858 #ifdef OPENSSL_HAS_ECC 859 sensitive_data.keys[2] = key_load_cert( 860 _PATH_HOST_ECDSA_KEY_FILE); 861 #endif 862 sensitive_data.keys[3] = key_load_cert( 863 _PATH_HOST_RSA_KEY_FILE); 864 sensitive_data.keys[4] = key_load_public( 865 _PATH_HOST_DSA_KEY_FILE, NULL); 866 #ifdef OPENSSL_HAS_ECC 867 sensitive_data.keys[5] = key_load_public( 868 _PATH_HOST_ECDSA_KEY_FILE, NULL); 869 #endif 870 sensitive_data.keys[6] = key_load_public( 871 _PATH_HOST_RSA_KEY_FILE, NULL); 872 sensitive_data.external_keysign = 1; 873 } 874 } 875 /* 876 * Get rid of any extra privileges that we may have. We will no 877 * longer need them. Also, extra privileges could make it very hard 878 * to read identity files and other non-world-readable files from the 879 * user's home directory if it happens to be on a NFS volume where 880 * root is mapped to nobody. 881 */ 882 if (original_effective_uid == 0) { 883 PRIV_START; 884 permanently_set_uid(pw); 885 } 886 887 /* 888 * Now that we are back to our own permissions, create ~/.ssh 889 * directory if it doesn't already exist. 890 */ 891 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 892 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 893 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) { 894 #ifdef WITH_SELINUX 895 ssh_selinux_setfscreatecon(buf); 896 #endif 897 if (mkdir(buf, 0700) < 0) 898 error("Could not create directory '%.200s'.", buf); 899 #ifdef WITH_SELINUX 900 ssh_selinux_setfscreatecon(NULL); 901 #endif 902 } 903 /* load options.identity_files */ 904 load_public_identity_files(); 905 906 /* Expand ~ in known host file names. */ 907 tilde_expand_paths(options.system_hostfiles, 908 options.num_system_hostfiles); 909 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 910 911 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 912 signal(SIGCHLD, main_sigchld_handler); 913 914 /* Log into the remote system. Never returns if the login fails. */ 915 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, 916 options.port, pw, timeout_ms); 917 918 if (packet_connection_is_on_socket()) { 919 verbose("Authenticated to %s ([%s]:%d).", host, 920 get_remote_ipaddr(), get_remote_port()); 921 } else { 922 verbose("Authenticated to %s (via proxy).", host); 923 } 924 925 /* We no longer need the private host keys. Clear them now. */ 926 if (sensitive_data.nkeys != 0) { 927 for (i = 0; i < sensitive_data.nkeys; i++) { 928 if (sensitive_data.keys[i] != NULL) { 929 /* Destroys contents safely */ 930 debug3("clear hostkey %d", i); 931 key_free(sensitive_data.keys[i]); 932 sensitive_data.keys[i] = NULL; 933 } 934 } 935 xfree(sensitive_data.keys); 936 } 937 for (i = 0; i < options.num_identity_files; i++) { 938 if (options.identity_files[i]) { 939 xfree(options.identity_files[i]); 940 options.identity_files[i] = NULL; 941 } 942 if (options.identity_keys[i]) { 943 key_free(options.identity_keys[i]); 944 options.identity_keys[i] = NULL; 945 } 946 } 947 948 exit_status = compat20 ? ssh_session2() : ssh_session(); 949 packet_close(); 950 951 if (options.control_path != NULL && muxserver_sock != -1) 952 unlink(options.control_path); 953 954 /* Kill ProxyCommand if it is running. */ 955 ssh_kill_proxy_command(); 956 957 return exit_status; 958 } 959 960 static void 961 control_persist_detach(void) 962 { 963 pid_t pid; 964 int devnull; 965 966 debug("%s: backgrounding master process", __func__); 967 968 /* 969 * master (current process) into the background, and make the 970 * foreground process a client of the backgrounded master. 971 */ 972 switch ((pid = fork())) { 973 case -1: 974 fatal("%s: fork: %s", __func__, strerror(errno)); 975 case 0: 976 /* Child: master process continues mainloop */ 977 break; 978 default: 979 /* Parent: set up mux slave to connect to backgrounded master */ 980 debug2("%s: background process is %ld", __func__, (long)pid); 981 stdin_null_flag = ostdin_null_flag; 982 options.request_tty = orequest_tty; 983 tty_flag = otty_flag; 984 close(muxserver_sock); 985 muxserver_sock = -1; 986 options.control_master = SSHCTL_MASTER_NO; 987 muxclient(options.control_path); 988 /* muxclient() doesn't return on success. */ 989 fatal("Failed to connect to new control master"); 990 } 991 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 992 error("%s: open(\"/dev/null\"): %s", __func__, 993 strerror(errno)); 994 } else { 995 if (dup2(devnull, STDIN_FILENO) == -1 || 996 dup2(devnull, STDOUT_FILENO) == -1) 997 error("%s: dup2: %s", __func__, strerror(errno)); 998 if (devnull > STDERR_FILENO) 999 close(devnull); 1000 } 1001 setproctitle("%s [mux]", options.control_path); 1002 } 1003 1004 /* Do fork() after authentication. Used by "ssh -f" */ 1005 static void 1006 fork_postauth(void) 1007 { 1008 if (need_controlpersist_detach) 1009 control_persist_detach(); 1010 debug("forking to background"); 1011 fork_after_authentication_flag = 0; 1012 if (daemon(1, 1) < 0) 1013 fatal("daemon() failed: %.200s", strerror(errno)); 1014 } 1015 1016 /* Callback for remote forward global requests */ 1017 static void 1018 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) 1019 { 1020 Forward *rfwd = (Forward *)ctxt; 1021 1022 /* XXX verbose() on failure? */ 1023 debug("remote forward %s for: listen %d, connect %s:%d", 1024 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1025 rfwd->listen_port, rfwd->connect_host, rfwd->connect_port); 1026 if (type == SSH2_MSG_REQUEST_SUCCESS && rfwd->listen_port == 0) { 1027 rfwd->allocated_port = packet_get_int(); 1028 logit("Allocated port %u for remote forward to %s:%d", 1029 rfwd->allocated_port, 1030 rfwd->connect_host, rfwd->connect_port); 1031 } 1032 1033 if (type == SSH2_MSG_REQUEST_FAILURE) { 1034 if (options.exit_on_forward_failure) 1035 fatal("Error: remote port forwarding failed for " 1036 "listen port %d", rfwd->listen_port); 1037 else 1038 logit("Warning: remote port forwarding failed for " 1039 "listen port %d", rfwd->listen_port); 1040 } 1041 if (++remote_forward_confirms_received == options.num_remote_forwards) { 1042 debug("All remote forwarding requests processed"); 1043 if (fork_after_authentication_flag) 1044 fork_postauth(); 1045 } 1046 } 1047 1048 static void 1049 client_cleanup_stdio_fwd(int id, void *arg) 1050 { 1051 debug("stdio forwarding: done"); 1052 cleanup_exit(0); 1053 } 1054 1055 static int 1056 client_setup_stdio_fwd(const char *host_to_connect, u_short port_to_connect) 1057 { 1058 Channel *c; 1059 int in, out; 1060 1061 debug3("client_setup_stdio_fwd %s:%d", host_to_connect, 1062 port_to_connect); 1063 1064 in = dup(STDIN_FILENO); 1065 out = dup(STDOUT_FILENO); 1066 if (in < 0 || out < 0) 1067 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1068 1069 if ((c = channel_connect_stdio_fwd(host_to_connect, port_to_connect, 1070 in, out)) == NULL) 1071 return 0; 1072 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0); 1073 return 1; 1074 } 1075 1076 static void 1077 ssh_init_forwarding(void) 1078 { 1079 int success = 0; 1080 int i; 1081 1082 if (stdio_forward_host != NULL) { 1083 if (!compat20) { 1084 fatal("stdio forwarding require Protocol 2"); 1085 } 1086 if (!client_setup_stdio_fwd(stdio_forward_host, 1087 stdio_forward_port)) 1088 fatal("Failed to connect in stdio forward mode."); 1089 } 1090 1091 /* Initiate local TCP/IP port forwardings. */ 1092 for (i = 0; i < options.num_local_forwards; i++) { 1093 debug("Local connections to %.200s:%d forwarded to remote " 1094 "address %.200s:%d", 1095 (options.local_forwards[i].listen_host == NULL) ? 1096 (options.gateway_ports ? "*" : "LOCALHOST") : 1097 options.local_forwards[i].listen_host, 1098 options.local_forwards[i].listen_port, 1099 options.local_forwards[i].connect_host, 1100 options.local_forwards[i].connect_port); 1101 success += channel_setup_local_fwd_listener( 1102 options.local_forwards[i].listen_host, 1103 options.local_forwards[i].listen_port, 1104 options.local_forwards[i].connect_host, 1105 options.local_forwards[i].connect_port, 1106 options.gateway_ports); 1107 } 1108 if (i > 0 && success != i && options.exit_on_forward_failure) 1109 fatal("Could not request local forwarding."); 1110 if (i > 0 && success == 0) 1111 error("Could not request local forwarding."); 1112 1113 /* Initiate remote TCP/IP port forwardings. */ 1114 for (i = 0; i < options.num_remote_forwards; i++) { 1115 debug("Remote connections from %.200s:%d forwarded to " 1116 "local address %.200s:%d", 1117 (options.remote_forwards[i].listen_host == NULL) ? 1118 "LOCALHOST" : options.remote_forwards[i].listen_host, 1119 options.remote_forwards[i].listen_port, 1120 options.remote_forwards[i].connect_host, 1121 options.remote_forwards[i].connect_port); 1122 if (channel_request_remote_forwarding( 1123 options.remote_forwards[i].listen_host, 1124 options.remote_forwards[i].listen_port, 1125 options.remote_forwards[i].connect_host, 1126 options.remote_forwards[i].connect_port) < 0) { 1127 if (options.exit_on_forward_failure) 1128 fatal("Could not request remote forwarding."); 1129 else 1130 logit("Warning: Could not request remote " 1131 "forwarding."); 1132 } 1133 client_register_global_confirm(ssh_confirm_remote_forward, 1134 &options.remote_forwards[i]); 1135 } 1136 1137 /* Initiate tunnel forwarding. */ 1138 if (options.tun_open != SSH_TUNMODE_NO) { 1139 if (client_request_tun_fwd(options.tun_open, 1140 options.tun_local, options.tun_remote) == -1) { 1141 if (options.exit_on_forward_failure) 1142 fatal("Could not request tunnel forwarding."); 1143 else 1144 error("Could not request tunnel forwarding."); 1145 } 1146 } 1147 } 1148 1149 static void 1150 check_agent_present(void) 1151 { 1152 if (options.forward_agent) { 1153 /* Clear agent forwarding if we don't have an agent. */ 1154 if (!ssh_agent_present()) 1155 options.forward_agent = 0; 1156 } 1157 } 1158 1159 static int 1160 ssh_session(void) 1161 { 1162 int type; 1163 int interactive = 0; 1164 int have_tty = 0; 1165 struct winsize ws; 1166 char *cp; 1167 const char *display; 1168 1169 /* Enable compression if requested. */ 1170 if (options.compression) { 1171 debug("Requesting compression at level %d.", 1172 options.compression_level); 1173 1174 if (options.compression_level < 1 || 1175 options.compression_level > 9) 1176 fatal("Compression level must be from 1 (fast) to " 1177 "9 (slow, best)."); 1178 1179 /* Send the request. */ 1180 packet_start(SSH_CMSG_REQUEST_COMPRESSION); 1181 packet_put_int(options.compression_level); 1182 packet_send(); 1183 packet_write_wait(); 1184 type = packet_read(); 1185 if (type == SSH_SMSG_SUCCESS) 1186 packet_start_compression(options.compression_level); 1187 else if (type == SSH_SMSG_FAILURE) 1188 logit("Warning: Remote host refused compression."); 1189 else 1190 packet_disconnect("Protocol error waiting for " 1191 "compression response."); 1192 } 1193 /* Allocate a pseudo tty if appropriate. */ 1194 if (tty_flag) { 1195 debug("Requesting pty."); 1196 1197 /* Start the packet. */ 1198 packet_start(SSH_CMSG_REQUEST_PTY); 1199 1200 /* Store TERM in the packet. There is no limit on the 1201 length of the string. */ 1202 cp = getenv("TERM"); 1203 if (!cp) 1204 cp = ""; 1205 packet_put_cstring(cp); 1206 1207 /* Store window size in the packet. */ 1208 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 1209 memset(&ws, 0, sizeof(ws)); 1210 packet_put_int((u_int)ws.ws_row); 1211 packet_put_int((u_int)ws.ws_col); 1212 packet_put_int((u_int)ws.ws_xpixel); 1213 packet_put_int((u_int)ws.ws_ypixel); 1214 1215 /* Store tty modes in the packet. */ 1216 tty_make_modes(fileno(stdin), NULL); 1217 1218 /* Send the packet, and wait for it to leave. */ 1219 packet_send(); 1220 packet_write_wait(); 1221 1222 /* Read response from the server. */ 1223 type = packet_read(); 1224 if (type == SSH_SMSG_SUCCESS) { 1225 interactive = 1; 1226 have_tty = 1; 1227 } else if (type == SSH_SMSG_FAILURE) 1228 logit("Warning: Remote host failed or refused to " 1229 "allocate a pseudo tty."); 1230 else 1231 packet_disconnect("Protocol error waiting for pty " 1232 "request response."); 1233 } 1234 /* Request X11 forwarding if enabled and DISPLAY is set. */ 1235 display = getenv("DISPLAY"); 1236 if (options.forward_x11 && display != NULL) { 1237 char *proto, *data; 1238 /* Get reasonable local authentication information. */ 1239 client_x11_get_proto(display, options.xauth_location, 1240 options.forward_x11_trusted, 1241 options.forward_x11_timeout, 1242 &proto, &data); 1243 /* Request forwarding with authentication spoofing. */ 1244 debug("Requesting X11 forwarding with authentication " 1245 "spoofing."); 1246 x11_request_forwarding_with_spoofing(0, display, proto, 1247 data, 0); 1248 /* Read response from the server. */ 1249 type = packet_read(); 1250 if (type == SSH_SMSG_SUCCESS) { 1251 interactive = 1; 1252 } else if (type == SSH_SMSG_FAILURE) { 1253 logit("Warning: Remote host denied X11 forwarding."); 1254 } else { 1255 packet_disconnect("Protocol error waiting for X11 " 1256 "forwarding"); 1257 } 1258 } 1259 /* Tell the packet module whether this is an interactive session. */ 1260 packet_set_interactive(interactive, 1261 options.ip_qos_interactive, options.ip_qos_bulk); 1262 1263 /* Request authentication agent forwarding if appropriate. */ 1264 check_agent_present(); 1265 1266 if (options.forward_agent) { 1267 debug("Requesting authentication agent forwarding."); 1268 auth_request_forwarding(); 1269 1270 /* Read response from the server. */ 1271 type = packet_read(); 1272 packet_check_eom(); 1273 if (type != SSH_SMSG_SUCCESS) 1274 logit("Warning: Remote host denied authentication agent forwarding."); 1275 } 1276 1277 /* Initiate port forwardings. */ 1278 ssh_init_forwarding(); 1279 1280 /* Execute a local command */ 1281 if (options.local_command != NULL && 1282 options.permit_local_command) 1283 ssh_local_cmd(options.local_command); 1284 1285 /* 1286 * If requested and we are not interested in replies to remote 1287 * forwarding requests, then let ssh continue in the background. 1288 */ 1289 if (fork_after_authentication_flag) { 1290 if (options.exit_on_forward_failure && 1291 options.num_remote_forwards > 0) { 1292 debug("deferring postauth fork until remote forward " 1293 "confirmation received"); 1294 } else 1295 fork_postauth(); 1296 } 1297 1298 /* 1299 * If a command was specified on the command line, execute the 1300 * command now. Otherwise request the server to start a shell. 1301 */ 1302 if (buffer_len(&command) > 0) { 1303 int len = buffer_len(&command); 1304 if (len > 900) 1305 len = 900; 1306 debug("Sending command: %.*s", len, 1307 (u_char *)buffer_ptr(&command)); 1308 packet_start(SSH_CMSG_EXEC_CMD); 1309 packet_put_string(buffer_ptr(&command), buffer_len(&command)); 1310 packet_send(); 1311 packet_write_wait(); 1312 } else { 1313 debug("Requesting shell."); 1314 packet_start(SSH_CMSG_EXEC_SHELL); 1315 packet_send(); 1316 packet_write_wait(); 1317 } 1318 1319 /* Enter the interactive session. */ 1320 return client_loop(have_tty, tty_flag ? 1321 options.escape_char : SSH_ESCAPECHAR_NONE, 0); 1322 } 1323 1324 /* request pty/x11/agent/tcpfwd/shell for channel */ 1325 static void 1326 ssh_session2_setup(int id, int success, void *arg) 1327 { 1328 extern char **environ; 1329 const char *display; 1330 int interactive = tty_flag; 1331 1332 if (!success) 1333 return; /* No need for error message, channels code sens one */ 1334 1335 display = getenv("DISPLAY"); 1336 if (options.forward_x11 && display != NULL) { 1337 char *proto, *data; 1338 /* Get reasonable local authentication information. */ 1339 client_x11_get_proto(display, options.xauth_location, 1340 options.forward_x11_trusted, 1341 options.forward_x11_timeout, &proto, &data); 1342 /* Request forwarding with authentication spoofing. */ 1343 debug("Requesting X11 forwarding with authentication " 1344 "spoofing."); 1345 x11_request_forwarding_with_spoofing(id, display, proto, 1346 data, 1); 1347 client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN); 1348 /* XXX exit_on_forward_failure */ 1349 interactive = 1; 1350 } 1351 1352 check_agent_present(); 1353 if (options.forward_agent) { 1354 debug("Requesting authentication agent forwarding."); 1355 channel_request_start(id, "auth-agent-req@openssh.com", 0); 1356 packet_send(); 1357 } 1358 1359 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), 1360 NULL, fileno(stdin), &command, environ); 1361 } 1362 1363 /* open new channel for a session */ 1364 static int 1365 ssh_session2_open(void) 1366 { 1367 Channel *c; 1368 int window, packetmax, in, out, err; 1369 int sock; 1370 int socksize; 1371 int socksizelen = sizeof(int); 1372 1373 if (stdin_null_flag) { 1374 in = open(_PATH_DEVNULL, O_RDONLY); 1375 } else { 1376 in = dup(STDIN_FILENO); 1377 } 1378 out = dup(STDOUT_FILENO); 1379 err = dup(STDERR_FILENO); 1380 1381 if (in < 0 || out < 0 || err < 0) 1382 fatal("dup() in/out/err failed"); 1383 1384 /* enable nonblocking unless tty */ 1385 if (!isatty(in)) 1386 set_nonblock(in); 1387 if (!isatty(out)) 1388 set_nonblock(out); 1389 if (!isatty(err)) 1390 set_nonblock(err); 1391 1392 /* we need to check to see if what they want to do about buffer */ 1393 /* sizes here. In a hpn to nonhpn connection we want to limit */ 1394 /* the window size to something reasonable in case the far side */ 1395 /* has the large window bug. In hpn to hpn connection we want to */ 1396 /* use the max window size but allow the user to override it */ 1397 /* lastly if they disabled hpn then use the ssh std window size */ 1398 1399 /* so why don't we just do a getsockopt() here and set the */ 1400 /* ssh window to that? In the case of a autotuning receive */ 1401 /* window the window would get stuck at the initial buffer */ 1402 /* size generally less than 96k. Therefore we need to set the */ 1403 /* maximum ssh window size to the maximum hpn buffer size */ 1404 /* unless the user has specifically set the tcprcvbufpoll */ 1405 /* to no. In which case we *can* just set the window to the */ 1406 /* minimum of the hpn buffer size and tcp receive buffer size */ 1407 1408 if (tty_flag) 1409 options.hpn_buffer_size = CHAN_SES_WINDOW_DEFAULT; 1410 else 1411 options.hpn_buffer_size = 2*1024*1024; 1412 1413 if (datafellows & SSH_BUG_LARGEWINDOW) 1414 { 1415 debug("HPN to Non-HPN Connection"); 1416 } 1417 else 1418 { 1419 if (options.tcp_rcv_buf_poll <= 0) 1420 { 1421 sock = socket(AF_INET, SOCK_STREAM, 0); 1422 getsockopt(sock, SOL_SOCKET, SO_RCVBUF, 1423 &socksize, &socksizelen); 1424 close(sock); 1425 debug("socksize %d", socksize); 1426 options.hpn_buffer_size = socksize; 1427 debug ("HPNBufferSize set to TCP RWIN: %d", options.hpn_buffer_size); 1428 } 1429 else 1430 { 1431 if (options.tcp_rcv_buf > 0) 1432 { 1433 /*create a socket but don't connect it */ 1434 /* we use that the get the rcv socket size */ 1435 sock = socket(AF_INET, SOCK_STREAM, 0); 1436 /* if they are using the tcp_rcv_buf option */ 1437 /* attempt to set the buffer size to that */ 1438 if (options.tcp_rcv_buf) 1439 setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void *)&options.tcp_rcv_buf, 1440 sizeof(options.tcp_rcv_buf)); 1441 getsockopt(sock, SOL_SOCKET, SO_RCVBUF, 1442 &socksize, &socksizelen); 1443 close(sock); 1444 debug("socksize %d", socksize); 1445 options.hpn_buffer_size = socksize; 1446 debug ("HPNBufferSize set to user TCPRcvBuf: %d", options.hpn_buffer_size); 1447 } 1448 } 1449 1450 } 1451 1452 debug("Final hpn_buffer_size = %d", options.hpn_buffer_size); 1453 1454 window = options.hpn_buffer_size; 1455 1456 channel_set_hpn(options.hpn_disabled, options.hpn_buffer_size); 1457 1458 packetmax = CHAN_SES_PACKET_DEFAULT; 1459 if (tty_flag) { 1460 window = 4*CHAN_SES_PACKET_DEFAULT; 1461 window >>= 1; 1462 packetmax >>= 1; 1463 } 1464 c = channel_new( 1465 "session", SSH_CHANNEL_OPENING, in, out, err, 1466 window, packetmax, CHAN_EXTENDED_WRITE, 1467 "client-session", /*nonblock*/0); 1468 if ((options.tcp_rcv_buf_poll > 0) && (!options.hpn_disabled)) { 1469 c->dynamic_window = 1; 1470 debug ("Enabled Dynamic Window Scaling\n"); 1471 } 1472 debug3("ssh_session2_open: channel_new: %d", c->self); 1473 1474 channel_send_open(c->self); 1475 if (!no_shell_flag) 1476 channel_register_open_confirm(c->self, 1477 ssh_session2_setup, NULL); 1478 1479 return c->self; 1480 } 1481 1482 static int 1483 ssh_session2(void) 1484 { 1485 int id = -1; 1486 1487 /* XXX should be pre-session */ 1488 ssh_init_forwarding(); 1489 1490 /* Start listening for multiplex clients */ 1491 muxserver_listen(); 1492 1493 /* 1494 * If we are in control persist mode, then prepare to background 1495 * ourselves and have a foreground client attach as a control 1496 * slave. NB. we must save copies of the flags that we override for 1497 * the backgrounding, since we defer attachment of the slave until 1498 * after the connection is fully established (in particular, 1499 * async rfwd replies have been received for ExitOnForwardFailure). 1500 */ 1501 if (options.control_persist && muxserver_sock != -1) { 1502 ostdin_null_flag = stdin_null_flag; 1503 ono_shell_flag = no_shell_flag; 1504 orequest_tty = options.request_tty; 1505 otty_flag = tty_flag; 1506 stdin_null_flag = 1; 1507 no_shell_flag = 1; 1508 tty_flag = 0; 1509 if (!fork_after_authentication_flag) 1510 need_controlpersist_detach = 1; 1511 fork_after_authentication_flag = 1; 1512 } 1513 1514 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) 1515 id = ssh_session2_open(); 1516 1517 /* If we don't expect to open a new session, then disallow it */ 1518 if (options.control_master == SSHCTL_MASTER_NO && 1519 (datafellows & SSH_NEW_OPENSSH)) { 1520 debug("Requesting no-more-sessions@openssh.com"); 1521 packet_start(SSH2_MSG_GLOBAL_REQUEST); 1522 packet_put_cstring("no-more-sessions@openssh.com"); 1523 packet_put_char(0); 1524 packet_send(); 1525 } 1526 1527 /* Execute a local command */ 1528 if (options.local_command != NULL && 1529 options.permit_local_command) 1530 ssh_local_cmd(options.local_command); 1531 1532 /* 1533 * If requested and we are not interested in replies to remote 1534 * forwarding requests, then let ssh continue in the background. 1535 */ 1536 if (fork_after_authentication_flag) { 1537 if (options.exit_on_forward_failure && 1538 options.num_remote_forwards > 0) { 1539 debug("deferring postauth fork until remote forward " 1540 "confirmation received"); 1541 } else 1542 fork_postauth(); 1543 } 1544 1545 if (options.use_roaming) 1546 request_roaming(); 1547 1548 return client_loop(tty_flag, tty_flag ? 1549 options.escape_char : SSH_ESCAPECHAR_NONE, id); 1550 } 1551 1552 static void 1553 load_public_identity_files(void) 1554 { 1555 char *filename, *cp, thishost[NI_MAXHOST]; 1556 char *pwdir = NULL, *pwname = NULL; 1557 int i = 0; 1558 Key *public; 1559 struct passwd *pw; 1560 u_int n_ids; 1561 char *identity_files[SSH_MAX_IDENTITY_FILES]; 1562 Key *identity_keys[SSH_MAX_IDENTITY_FILES]; 1563 #ifdef ENABLE_PKCS11 1564 Key **keys; 1565 int nkeys; 1566 #endif /* PKCS11 */ 1567 1568 n_ids = 0; 1569 bzero(identity_files, sizeof(identity_files)); 1570 bzero(identity_keys, sizeof(identity_keys)); 1571 1572 #ifdef ENABLE_PKCS11 1573 if (options.pkcs11_provider != NULL && 1574 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 1575 (pkcs11_init(!options.batch_mode) == 0) && 1576 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 1577 &keys)) > 0) { 1578 for (i = 0; i < nkeys; i++) { 1579 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 1580 key_free(keys[i]); 1581 continue; 1582 } 1583 identity_keys[n_ids] = keys[i]; 1584 identity_files[n_ids] = 1585 xstrdup(options.pkcs11_provider); /* XXX */ 1586 n_ids++; 1587 } 1588 xfree(keys); 1589 } 1590 #endif /* ENABLE_PKCS11 */ 1591 if ((pw = getpwuid(original_real_uid)) == NULL) 1592 fatal("load_public_identity_files: getpwuid failed"); 1593 pwname = xstrdup(pw->pw_name); 1594 pwdir = xstrdup(pw->pw_dir); 1595 if (gethostname(thishost, sizeof(thishost)) == -1) 1596 fatal("load_public_identity_files: gethostname: %s", 1597 strerror(errno)); 1598 for (i = 0; i < options.num_identity_files; i++) { 1599 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 1600 xfree(options.identity_files[i]); 1601 continue; 1602 } 1603 cp = tilde_expand_filename(options.identity_files[i], 1604 original_real_uid); 1605 filename = percent_expand(cp, "d", pwdir, 1606 "u", pwname, "l", thishost, "h", host, 1607 "r", options.user, (char *)NULL); 1608 xfree(cp); 1609 public = key_load_public(filename, NULL); 1610 debug("identity file %s type %d", filename, 1611 public ? public->type : -1); 1612 xfree(options.identity_files[i]); 1613 identity_files[n_ids] = filename; 1614 identity_keys[n_ids] = public; 1615 1616 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 1617 continue; 1618 1619 /* Try to add the certificate variant too */ 1620 xasprintf(&cp, "%s-cert", filename); 1621 public = key_load_public(cp, NULL); 1622 debug("identity file %s type %d", cp, 1623 public ? public->type : -1); 1624 if (public == NULL) { 1625 xfree(cp); 1626 continue; 1627 } 1628 if (!key_is_cert(public)) { 1629 debug("%s: key %s type %s is not a certificate", 1630 __func__, cp, key_type(public)); 1631 key_free(public); 1632 xfree(cp); 1633 continue; 1634 } 1635 identity_keys[n_ids] = public; 1636 /* point to the original path, most likely the private key */ 1637 identity_files[n_ids] = xstrdup(filename); 1638 n_ids++; 1639 } 1640 options.num_identity_files = n_ids; 1641 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 1642 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 1643 1644 bzero(pwname, strlen(pwname)); 1645 xfree(pwname); 1646 bzero(pwdir, strlen(pwdir)); 1647 xfree(pwdir); 1648 } 1649 1650 static void 1651 main_sigchld_handler(int sig) 1652 { 1653 int save_errno = errno; 1654 pid_t pid; 1655 int status; 1656 1657 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 1658 (pid < 0 && errno == EINTR)) 1659 ; 1660 1661 signal(sig, main_sigchld_handler); 1662 errno = save_errno; 1663 } 1664 1665