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 112extern char *__progname; 113 114/* Saves a copy of argv for setproctitle emulation */ 115#ifndef HAVE_SETPROCTITLE 116static char **saved_av; 117#endif 118 119/* Flag indicating whether debug mode is on. May be set on the command line. */ 120int debug_flag = 0; 121 122/* Flag indicating whether a tty should be requested */ 123int tty_flag = 0; 124 125/* don't exec a shell */ 126int 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 */ 132int 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 */ 138int need_controlpersist_detach = 0; 139 140/* Copies of flags for ControlPersist foreground slave */ 141int 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 */ 148int fork_after_authentication_flag = 0; 149 150/* forward stdio to remote host and port */ 151char *stdio_forward_host = NULL; 152int 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 */ 158Options options; 159 160/* optional user configfile */ 161char *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 */ 168char *host; 169 170/* socket address the host resolves to */ 171struct sockaddr_storage hostaddr; 172 173/* Private host keys. */ 174Sensitive sensitive_data; 175 176/* Original real UID. */ 177uid_t original_real_uid; 178uid_t original_effective_uid; 179 180/* command to be executed */ 181Buffer command; 182 183/* Should we execute a command or invoke a subsystem? */ 184int subsystem_flag = 0; 185 186/* # of replies received for global requests */ 187static int remote_forward_confirms_received = 0; 188 189/* mux.c */ 190extern int muxserver_sock; 191extern u_int muxclient_command; 192 193/* Prints a help message to the user. This function never returns. */ 194 195static void 196usage(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 211static int ssh_session(void); 212static int ssh_session2(void); 213static void load_public_identity_files(void); 214static void main_sigchld_handler(int); 215 216/* from muxclient.c */ 217void muxclient(const char *); 218void muxserver_listen(void); 219 220/* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 221static void 222tilde_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 */ 237int 238main(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 break; 581 case 'o': 582 dummy = 1; 583 line = xstrdup(optarg); 584 if (process_config_line(&options, host ? host : "", 585 line, "command-line", 0, &dummy) != 0) 586 exit(255); 587 xfree(line); 588 break; 589 case 's': 590 subsystem_flag = 1; 591 break; 592 case 'S': 593 if (options.control_path != NULL) 594 free(options.control_path); 595 options.control_path = xstrdup(optarg); 596 break; 597 case 'b': 598 options.bind_address = optarg; 599 break; 600 case 'F': 601 config = optarg; 602 break; 603 default: 604 usage(); 605 } 606 } 607 608 ac -= optind; 609 av += optind; 610 611 if (ac > 0 && !host) { 612 if (strrchr(*av, '@')) { 613 p = xstrdup(*av); 614 cp = strrchr(p, '@'); 615 if (cp == NULL || cp == p) 616 usage(); 617 options.user = p; 618 *cp = '\0'; 619 host = ++cp; 620 } else 621 host = *av; 622 if (ac > 1) { 623 optind = optreset = 1; 624 goto again; 625 } 626 ac--, av++; 627 } 628 629 /* Check that we got a host name. */ 630 if (!host) 631 usage(); 632 633 OpenSSL_add_all_algorithms(); 634 ERR_load_crypto_strings(); 635 636 /* Initialize the command to execute on remote host. */ 637 buffer_init(&command); 638 639 if (options.request_tty == REQUEST_TTY_YES || 640 options.request_tty == REQUEST_TTY_FORCE) 641 tty_flag = 1; 642 643 /* 644 * Save the command to execute on the remote host in a buffer. There 645 * is no limit on the length of the command, except by the maximum 646 * packet size. Also sets the tty flag if there is no command. 647 */ 648 if (!ac) { 649 /* No command specified - execute shell on a tty. */ 650 tty_flag = options.request_tty != REQUEST_TTY_NO; 651 if (subsystem_flag) { 652 fprintf(stderr, 653 "You must specify a subsystem to invoke.\n"); 654 usage(); 655 } 656 } else { 657 /* A command has been specified. Store it into the buffer. */ 658 for (i = 0; i < ac; i++) { 659 if (i) 660 buffer_append(&command, " ", 1); 661 buffer_append(&command, av[i], strlen(av[i])); 662 } 663 } 664 665 /* Cannot fork to background if no command. */ 666 if (fork_after_authentication_flag && buffer_len(&command) == 0 && 667 !no_shell_flag) 668 fatal("Cannot fork into background without a command " 669 "to execute."); 670 671 /* Allocate a tty by default if no command specified. */ 672 if (buffer_len(&command) == 0) 673 tty_flag = options.request_tty != REQUEST_TTY_NO; 674 675 /* Force no tty */ 676 if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0) 677 tty_flag = 0; 678 /* Do not allocate a tty if stdin is not a tty. */ 679 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 680 options.request_tty != REQUEST_TTY_FORCE) { 681 if (tty_flag) 682 logit("Pseudo-terminal will not be allocated because " 683 "stdin is not a terminal."); 684 tty_flag = 0; 685 } 686 687 /* 688 * Initialize "log" output. Since we are the client all output 689 * actually goes to stderr. 690 */ 691 log_init(argv0, 692 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, 693 SYSLOG_FACILITY_USER, !use_syslog); 694 695 /* 696 * Read per-user configuration file. Ignore the system wide config 697 * file if the user specifies a config file on the command line. 698 */ 699 if (config != NULL) { 700 if (!read_config_file(config, host, &options, 0)) 701 fatal("Can't open user config file %.100s: " 702 "%.100s", config, strerror(errno)); 703 } else { 704 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 705 _PATH_SSH_USER_CONFFILE); 706 if (r > 0 && (size_t)r < sizeof(buf)) 707 (void)read_config_file(buf, host, &options, 1); 708 709 /* Read systemwide configuration file after user config. */ 710 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, 711 &options, 0); 712 } 713 714 /* Fill configuration defaults. */ 715 fill_default_options(&options); 716 717 channel_set_af(options.address_family); 718 719 /* reinit */ 720 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog); 721 722 seed_rng(); 723 724 if (options.user == NULL) 725 options.user = xstrdup(pw->pw_name); 726 727 /* Get default port if port has not been set. */ 728 if (options.port == 0) { 729 sp = getservbyname(SSH_SERVICE_NAME, "tcp"); 730 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT; 731 } 732 733 /* preserve host name given on command line for %n expansion */ 734 host_arg = host; 735 if (options.hostname != NULL) { 736 host = percent_expand(options.hostname, 737 "h", host, (char *)NULL); 738 } 739 740 if (gethostname(thishost, sizeof(thishost)) == -1) 741 fatal("gethostname: %s", strerror(errno)); 742 strlcpy(shorthost, thishost, sizeof(shorthost)); 743 shorthost[strcspn(thishost, ".")] = '\0'; 744 snprintf(portstr, sizeof(portstr), "%d", options.port); 745 746 if (options.local_command != NULL) { 747 debug3("expanding LocalCommand: %s", options.local_command); 748 cp = options.local_command; 749 options.local_command = percent_expand(cp, "d", pw->pw_dir, 750 "h", host, "l", thishost, "n", host_arg, "r", options.user, 751 "p", portstr, "u", pw->pw_name, "L", shorthost, 752 (char *)NULL); 753 debug3("expanded LocalCommand: %s", options.local_command); 754 xfree(cp); 755 } 756 757 /* force lowercase for hostkey matching */ 758 if (options.host_key_alias != NULL) { 759 for (p = options.host_key_alias; *p; p++) 760 if (isupper(*p)) 761 *p = (char)tolower(*p); 762 } 763 764 if (options.proxy_command != NULL && 765 strcmp(options.proxy_command, "none") == 0) { 766 xfree(options.proxy_command); 767 options.proxy_command = NULL; 768 } 769 if (options.control_path != NULL && 770 strcmp(options.control_path, "none") == 0) { 771 xfree(options.control_path); 772 options.control_path = NULL; 773 } 774 775 if (options.control_path != NULL) { 776 cp = tilde_expand_filename(options.control_path, 777 original_real_uid); 778 xfree(options.control_path); 779 options.control_path = percent_expand(cp, "h", host, 780 "l", thishost, "n", host_arg, "r", options.user, 781 "p", portstr, "u", pw->pw_name, "L", shorthost, 782 (char *)NULL); 783 xfree(cp); 784 } 785 if (muxclient_command != 0 && options.control_path == NULL) 786 fatal("No ControlPath specified for \"-O\" command"); 787 if (options.control_path != NULL) 788 muxclient(options.control_path); 789 790 timeout_ms = options.connection_timeout * 1000; 791 792 /* Open a connection to the remote host. */ 793 if (ssh_connect(host, &hostaddr, options.port, 794 options.address_family, options.connection_attempts, &timeout_ms, 795 options.tcp_keep_alive, 796#ifdef HAVE_CYGWIN 797 options.use_privileged_port, 798#else 799 original_effective_uid == 0 && options.use_privileged_port, 800#endif 801 options.proxy_command) != 0) 802 exit(255); 803 804 if (timeout_ms > 0) 805 debug3("timeout: %d ms remain after connect", timeout_ms); 806 807 /* 808 * If we successfully made the connection, load the host private key 809 * in case we will need it later for combined rsa-rhosts 810 * authentication. This must be done before releasing extra 811 * privileges, because the file is only readable by root. 812 * If we cannot access the private keys, load the public keys 813 * instead and try to execute the ssh-keysign helper instead. 814 */ 815 sensitive_data.nkeys = 0; 816 sensitive_data.keys = NULL; 817 sensitive_data.external_keysign = 0; 818 if (options.rhosts_rsa_authentication || 819 options.hostbased_authentication) { 820 sensitive_data.nkeys = 7; 821 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 822 sizeof(Key)); 823 for (i = 0; i < sensitive_data.nkeys; i++) 824 sensitive_data.keys[i] = NULL; 825 826 PRIV_START; 827 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, 828 _PATH_HOST_KEY_FILE, "", NULL, NULL); 829 sensitive_data.keys[1] = key_load_private_cert(KEY_DSA, 830 _PATH_HOST_DSA_KEY_FILE, "", NULL); 831#ifdef OPENSSL_HAS_ECC 832 sensitive_data.keys[2] = key_load_private_cert(KEY_ECDSA, 833 _PATH_HOST_ECDSA_KEY_FILE, "", NULL); 834#endif 835 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA, 836 _PATH_HOST_RSA_KEY_FILE, "", NULL); 837 sensitive_data.keys[4] = key_load_private_type(KEY_DSA, 838 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); 839#ifdef OPENSSL_HAS_ECC 840 sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA, 841 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL); 842#endif 843 sensitive_data.keys[6] = key_load_private_type(KEY_RSA, 844 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); 845 PRIV_END; 846 847 if (options.hostbased_authentication == 1 && 848 sensitive_data.keys[0] == NULL && 849 sensitive_data.keys[4] == NULL && 850 sensitive_data.keys[5] == NULL && 851 sensitive_data.keys[6] == NULL) { 852 sensitive_data.keys[1] = key_load_cert( 853 _PATH_HOST_DSA_KEY_FILE); 854#ifdef OPENSSL_HAS_ECC 855 sensitive_data.keys[2] = key_load_cert( 856 _PATH_HOST_ECDSA_KEY_FILE); 857#endif 858 sensitive_data.keys[3] = key_load_cert( 859 _PATH_HOST_RSA_KEY_FILE); 860 sensitive_data.keys[4] = key_load_public( 861 _PATH_HOST_DSA_KEY_FILE, NULL); 862#ifdef OPENSSL_HAS_ECC 863 sensitive_data.keys[5] = key_load_public( 864 _PATH_HOST_ECDSA_KEY_FILE, NULL); 865#endif 866 sensitive_data.keys[6] = key_load_public( 867 _PATH_HOST_RSA_KEY_FILE, NULL); 868 sensitive_data.external_keysign = 1; 869 } 870 } 871 /* 872 * Get rid of any extra privileges that we may have. We will no 873 * longer need them. Also, extra privileges could make it very hard 874 * to read identity files and other non-world-readable files from the 875 * user's home directory if it happens to be on a NFS volume where 876 * root is mapped to nobody. 877 */ 878 if (original_effective_uid == 0) { 879 PRIV_START; 880 permanently_set_uid(pw); 881 } 882 883 /* 884 * Now that we are back to our own permissions, create ~/.ssh 885 * directory if it doesn't already exist. 886 */ 887 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 888 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 889 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) { 890#ifdef WITH_SELINUX 891 ssh_selinux_setfscreatecon(buf); 892#endif 893 if (mkdir(buf, 0700) < 0) 894 error("Could not create directory '%.200s'.", buf); 895#ifdef WITH_SELINUX 896 ssh_selinux_setfscreatecon(NULL); 897#endif 898 } 899 /* load options.identity_files */ 900 load_public_identity_files(); 901 902 /* Expand ~ in known host file names. */ 903 tilde_expand_paths(options.system_hostfiles, 904 options.num_system_hostfiles); 905 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 906 907 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 908 signal(SIGCHLD, main_sigchld_handler); 909 910 /* Log into the remote system. Never returns if the login fails. */ 911 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, 912 options.port, pw, timeout_ms); 913 914 if (packet_connection_is_on_socket()) { 915 verbose("Authenticated to %s ([%s]:%d).", host, 916 get_remote_ipaddr(), get_remote_port()); 917 } else { 918 verbose("Authenticated to %s (via proxy).", host); 919 } 920 921 /* We no longer need the private host keys. Clear them now. */ 922 if (sensitive_data.nkeys != 0) { 923 for (i = 0; i < sensitive_data.nkeys; i++) { 924 if (sensitive_data.keys[i] != NULL) { 925 /* Destroys contents safely */ 926 debug3("clear hostkey %d", i); 927 key_free(sensitive_data.keys[i]); 928 sensitive_data.keys[i] = NULL; 929 } 930 } 931 xfree(sensitive_data.keys); 932 } 933 for (i = 0; i < options.num_identity_files; i++) { 934 if (options.identity_files[i]) { 935 xfree(options.identity_files[i]); 936 options.identity_files[i] = NULL; 937 } 938 if (options.identity_keys[i]) { 939 key_free(options.identity_keys[i]); 940 options.identity_keys[i] = NULL; 941 } 942 } 943 944 exit_status = compat20 ? ssh_session2() : ssh_session(); 945 packet_close(); 946 947 if (options.control_path != NULL && muxserver_sock != -1) 948 unlink(options.control_path); 949 950 /* Kill ProxyCommand if it is running. */ 951 ssh_kill_proxy_command(); 952 953 return exit_status; 954} 955 956static void 957control_persist_detach(void) 958{ 959 pid_t pid; 960 int devnull; 961 962 debug("%s: backgrounding master process", __func__); 963 964 /* 965 * master (current process) into the background, and make the 966 * foreground process a client of the backgrounded master. 967 */ 968 switch ((pid = fork())) { 969 case -1: 970 fatal("%s: fork: %s", __func__, strerror(errno)); 971 case 0: 972 /* Child: master process continues mainloop */ 973 break; 974 default: 975 /* Parent: set up mux slave to connect to backgrounded master */ 976 debug2("%s: background process is %ld", __func__, (long)pid); 977 stdin_null_flag = ostdin_null_flag; 978 options.request_tty = orequest_tty; 979 tty_flag = otty_flag; 980 close(muxserver_sock); 981 muxserver_sock = -1; 982 options.control_master = SSHCTL_MASTER_NO; 983 muxclient(options.control_path); 984 /* muxclient() doesn't return on success. */ 985 fatal("Failed to connect to new control master"); 986 } 987 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 988 error("%s: open(\"/dev/null\"): %s", __func__, 989 strerror(errno)); 990 } else { 991 if (dup2(devnull, STDIN_FILENO) == -1 || 992 dup2(devnull, STDOUT_FILENO) == -1) 993 error("%s: dup2: %s", __func__, strerror(errno)); 994 if (devnull > STDERR_FILENO) 995 close(devnull); 996 } 997 setproctitle("%s [mux]", options.control_path); 998} 999 1000/* Do fork() after authentication. Used by "ssh -f" */ 1001static void 1002fork_postauth(void) 1003{ 1004 if (need_controlpersist_detach) 1005 control_persist_detach(); 1006 debug("forking to background"); 1007 fork_after_authentication_flag = 0; 1008 if (daemon(1, 1) < 0) 1009 fatal("daemon() failed: %.200s", strerror(errno)); 1010} 1011 1012/* Callback for remote forward global requests */ 1013static void 1014ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) 1015{ 1016 Forward *rfwd = (Forward *)ctxt; 1017 1018 /* XXX verbose() on failure? */ 1019 debug("remote forward %s for: listen %d, connect %s:%d", 1020 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1021 rfwd->listen_port, rfwd->connect_host, rfwd->connect_port); 1022 if (type == SSH2_MSG_REQUEST_SUCCESS && rfwd->listen_port == 0) { 1023 rfwd->allocated_port = packet_get_int(); 1024 logit("Allocated port %u for remote forward to %s:%d", 1025 rfwd->allocated_port, 1026 rfwd->connect_host, rfwd->connect_port); 1027 } 1028 1029 if (type == SSH2_MSG_REQUEST_FAILURE) { 1030 if (options.exit_on_forward_failure) 1031 fatal("Error: remote port forwarding failed for " 1032 "listen port %d", rfwd->listen_port); 1033 else 1034 logit("Warning: remote port forwarding failed for " 1035 "listen port %d", rfwd->listen_port); 1036 } 1037 if (++remote_forward_confirms_received == options.num_remote_forwards) { 1038 debug("All remote forwarding requests processed"); 1039 if (fork_after_authentication_flag) 1040 fork_postauth(); 1041 } 1042} 1043 1044static void 1045client_cleanup_stdio_fwd(int id, void *arg) 1046{ 1047 debug("stdio forwarding: done"); 1048 cleanup_exit(0); 1049} 1050 1051static int 1052client_setup_stdio_fwd(const char *host_to_connect, u_short port_to_connect) 1053{ 1054 Channel *c; 1055 int in, out; 1056 1057 debug3("client_setup_stdio_fwd %s:%d", host_to_connect, 1058 port_to_connect); 1059 1060 in = dup(STDIN_FILENO); 1061 out = dup(STDOUT_FILENO); 1062 if (in < 0 || out < 0) 1063 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1064 1065 if ((c = channel_connect_stdio_fwd(host_to_connect, port_to_connect, 1066 in, out)) == NULL) 1067 return 0; 1068 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0); 1069 return 1; 1070} 1071 1072static void 1073ssh_init_forwarding(void) 1074{ 1075 int success = 0; 1076 int i; 1077 1078 if (stdio_forward_host != NULL) { 1079 if (!compat20) { 1080 fatal("stdio forwarding require Protocol 2"); 1081 } 1082 if (!client_setup_stdio_fwd(stdio_forward_host, 1083 stdio_forward_port)) 1084 fatal("Failed to connect in stdio forward mode."); 1085 } 1086 1087 /* Initiate local TCP/IP port forwardings. */ 1088 for (i = 0; i < options.num_local_forwards; i++) { 1089 debug("Local connections to %.200s:%d forwarded to remote " 1090 "address %.200s:%d", 1091 (options.local_forwards[i].listen_host == NULL) ? 1092 (options.gateway_ports ? "*" : "LOCALHOST") : 1093 options.local_forwards[i].listen_host, 1094 options.local_forwards[i].listen_port, 1095 options.local_forwards[i].connect_host, 1096 options.local_forwards[i].connect_port); 1097 success += channel_setup_local_fwd_listener( 1098 options.local_forwards[i].listen_host, 1099 options.local_forwards[i].listen_port, 1100 options.local_forwards[i].connect_host, 1101 options.local_forwards[i].connect_port, 1102 options.gateway_ports); 1103 } 1104 if (i > 0 && success != i && options.exit_on_forward_failure) 1105 fatal("Could not request local forwarding."); 1106 if (i > 0 && success == 0) 1107 error("Could not request local forwarding."); 1108 1109 /* Initiate remote TCP/IP port forwardings. */ 1110 for (i = 0; i < options.num_remote_forwards; i++) { 1111 debug("Remote connections from %.200s:%d forwarded to " 1112 "local address %.200s:%d", 1113 (options.remote_forwards[i].listen_host == NULL) ? 1114 "LOCALHOST" : options.remote_forwards[i].listen_host, 1115 options.remote_forwards[i].listen_port, 1116 options.remote_forwards[i].connect_host, 1117 options.remote_forwards[i].connect_port); 1118 if (channel_request_remote_forwarding( 1119 options.remote_forwards[i].listen_host, 1120 options.remote_forwards[i].listen_port, 1121 options.remote_forwards[i].connect_host, 1122 options.remote_forwards[i].connect_port) < 0) { 1123 if (options.exit_on_forward_failure) 1124 fatal("Could not request remote forwarding."); 1125 else 1126 logit("Warning: Could not request remote " 1127 "forwarding."); 1128 } 1129 client_register_global_confirm(ssh_confirm_remote_forward, 1130 &options.remote_forwards[i]); 1131 } 1132 1133 /* Initiate tunnel forwarding. */ 1134 if (options.tun_open != SSH_TUNMODE_NO) { 1135 if (client_request_tun_fwd(options.tun_open, 1136 options.tun_local, options.tun_remote) == -1) { 1137 if (options.exit_on_forward_failure) 1138 fatal("Could not request tunnel forwarding."); 1139 else 1140 error("Could not request tunnel forwarding."); 1141 } 1142 } 1143} 1144 1145static void 1146check_agent_present(void) 1147{ 1148 if (options.forward_agent) { 1149 /* Clear agent forwarding if we don't have an agent. */ 1150 if (!ssh_agent_present()) 1151 options.forward_agent = 0; 1152 } 1153} 1154 1155static int 1156ssh_session(void) 1157{ 1158 int type; 1159 int interactive = 0; 1160 int have_tty = 0; 1161 struct winsize ws; 1162 char *cp; 1163 const char *display; 1164 1165 /* Enable compression if requested. */ 1166 if (options.compression) { 1167 debug("Requesting compression at level %d.", 1168 options.compression_level); 1169 1170 if (options.compression_level < 1 || 1171 options.compression_level > 9) 1172 fatal("Compression level must be from 1 (fast) to " 1173 "9 (slow, best)."); 1174 1175 /* Send the request. */ 1176 packet_start(SSH_CMSG_REQUEST_COMPRESSION); 1177 packet_put_int(options.compression_level); 1178 packet_send(); 1179 packet_write_wait(); 1180 type = packet_read(); 1181 if (type == SSH_SMSG_SUCCESS) 1182 packet_start_compression(options.compression_level); 1183 else if (type == SSH_SMSG_FAILURE) 1184 logit("Warning: Remote host refused compression."); 1185 else 1186 packet_disconnect("Protocol error waiting for " 1187 "compression response."); 1188 } 1189 /* Allocate a pseudo tty if appropriate. */ 1190 if (tty_flag) { 1191 debug("Requesting pty."); 1192 1193 /* Start the packet. */ 1194 packet_start(SSH_CMSG_REQUEST_PTY); 1195 1196 /* Store TERM in the packet. There is no limit on the 1197 length of the string. */ 1198 cp = getenv("TERM"); 1199 if (!cp) 1200 cp = ""; 1201 packet_put_cstring(cp); 1202 1203 /* Store window size in the packet. */ 1204 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 1205 memset(&ws, 0, sizeof(ws)); 1206 packet_put_int((u_int)ws.ws_row); 1207 packet_put_int((u_int)ws.ws_col); 1208 packet_put_int((u_int)ws.ws_xpixel); 1209 packet_put_int((u_int)ws.ws_ypixel); 1210 1211 /* Store tty modes in the packet. */ 1212 tty_make_modes(fileno(stdin), NULL); 1213 1214 /* Send the packet, and wait for it to leave. */ 1215 packet_send(); 1216 packet_write_wait(); 1217 1218 /* Read response from the server. */ 1219 type = packet_read(); 1220 if (type == SSH_SMSG_SUCCESS) { 1221 interactive = 1; 1222 have_tty = 1; 1223 } else if (type == SSH_SMSG_FAILURE) 1224 logit("Warning: Remote host failed or refused to " 1225 "allocate a pseudo tty."); 1226 else 1227 packet_disconnect("Protocol error waiting for pty " 1228 "request response."); 1229 } 1230 /* Request X11 forwarding if enabled and DISPLAY is set. */ 1231 display = getenv("DISPLAY"); 1232 if (options.forward_x11 && display != NULL) { 1233 char *proto, *data; 1234 /* Get reasonable local authentication information. */ 1235 client_x11_get_proto(display, options.xauth_location, 1236 options.forward_x11_trusted, 1237 options.forward_x11_timeout, 1238 &proto, &data); 1239 /* Request forwarding with authentication spoofing. */ 1240 debug("Requesting X11 forwarding with authentication " 1241 "spoofing."); 1242 x11_request_forwarding_with_spoofing(0, display, proto, 1243 data, 0); 1244 /* Read response from the server. */ 1245 type = packet_read(); 1246 if (type == SSH_SMSG_SUCCESS) { 1247 interactive = 1; 1248 } else if (type == SSH_SMSG_FAILURE) { 1249 logit("Warning: Remote host denied X11 forwarding."); 1250 } else { 1251 packet_disconnect("Protocol error waiting for X11 " 1252 "forwarding"); 1253 } 1254 } 1255 /* Tell the packet module whether this is an interactive session. */ 1256 packet_set_interactive(interactive, 1257 options.ip_qos_interactive, options.ip_qos_bulk); 1258 1259 /* Request authentication agent forwarding if appropriate. */ 1260 check_agent_present(); 1261 1262 if (options.forward_agent) { 1263 debug("Requesting authentication agent forwarding."); 1264 auth_request_forwarding(); 1265 1266 /* Read response from the server. */ 1267 type = packet_read(); 1268 packet_check_eom(); 1269 if (type != SSH_SMSG_SUCCESS) 1270 logit("Warning: Remote host denied authentication agent forwarding."); 1271 } 1272 1273 /* Initiate port forwardings. */ 1274 ssh_init_forwarding(); 1275 1276 /* Execute a local command */ 1277 if (options.local_command != NULL && 1278 options.permit_local_command) 1279 ssh_local_cmd(options.local_command); 1280 1281 /* 1282 * If requested and we are not interested in replies to remote 1283 * forwarding requests, then let ssh continue in the background. 1284 */ 1285 if (fork_after_authentication_flag) { 1286 if (options.exit_on_forward_failure && 1287 options.num_remote_forwards > 0) { 1288 debug("deferring postauth fork until remote forward " 1289 "confirmation received"); 1290 } else 1291 fork_postauth(); 1292 } 1293 1294 /* 1295 * If a command was specified on the command line, execute the 1296 * command now. Otherwise request the server to start a shell. 1297 */ 1298 if (buffer_len(&command) > 0) { 1299 int len = buffer_len(&command); 1300 if (len > 900) 1301 len = 900; 1302 debug("Sending command: %.*s", len, 1303 (u_char *)buffer_ptr(&command)); 1304 packet_start(SSH_CMSG_EXEC_CMD); 1305 packet_put_string(buffer_ptr(&command), buffer_len(&command)); 1306 packet_send(); 1307 packet_write_wait(); 1308 } else { 1309 debug("Requesting shell."); 1310 packet_start(SSH_CMSG_EXEC_SHELL); 1311 packet_send(); 1312 packet_write_wait(); 1313 } 1314 1315 /* Enter the interactive session. */ 1316 return client_loop(have_tty, tty_flag ? 1317 options.escape_char : SSH_ESCAPECHAR_NONE, 0); 1318} 1319 1320/* request pty/x11/agent/tcpfwd/shell for channel */ 1321static void 1322ssh_session2_setup(int id, int success, void *arg) 1323{ 1324 extern char **environ; 1325 const char *display; 1326 int interactive = tty_flag; 1327 1328 if (!success) 1329 return; /* No need for error message, channels code sens one */ 1330 1331 display = getenv("DISPLAY"); 1332 if (options.forward_x11 && display != NULL) { 1333 char *proto, *data; 1334 /* Get reasonable local authentication information. */ 1335 client_x11_get_proto(display, options.xauth_location, 1336 options.forward_x11_trusted, 1337 options.forward_x11_timeout, &proto, &data); 1338 /* Request forwarding with authentication spoofing. */ 1339 debug("Requesting X11 forwarding with authentication " 1340 "spoofing."); 1341 x11_request_forwarding_with_spoofing(id, display, proto, 1342 data, 1); 1343 client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN); 1344 /* XXX exit_on_forward_failure */ 1345 interactive = 1; 1346 } 1347 1348 check_agent_present(); 1349 if (options.forward_agent) { 1350 debug("Requesting authentication agent forwarding."); 1351 channel_request_start(id, "auth-agent-req@openssh.com", 0); 1352 packet_send(); 1353 } 1354 1355 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), 1356 NULL, fileno(stdin), &command, environ); 1357} 1358 1359/* open new channel for a session */ 1360static int 1361ssh_session2_open(void) 1362{ 1363 Channel *c; 1364 int window, packetmax, in, out, err; 1365 1366 if (stdin_null_flag) { 1367 in = open(_PATH_DEVNULL, O_RDONLY); 1368 } else { 1369 in = dup(STDIN_FILENO); 1370 } 1371 out = dup(STDOUT_FILENO); 1372 err = dup(STDERR_FILENO); 1373 1374 if (in < 0 || out < 0 || err < 0) 1375 fatal("dup() in/out/err failed"); 1376 1377 /* enable nonblocking unless tty */ 1378 if (!isatty(in)) 1379 set_nonblock(in); 1380 if (!isatty(out)) 1381 set_nonblock(out); 1382 if (!isatty(err)) 1383 set_nonblock(err); 1384 1385 window = CHAN_SES_WINDOW_DEFAULT; 1386 packetmax = CHAN_SES_PACKET_DEFAULT; 1387 if (tty_flag) { 1388 window >>= 1; 1389 packetmax >>= 1; 1390 } 1391 c = channel_new( 1392 "session", SSH_CHANNEL_OPENING, in, out, err, 1393 window, packetmax, CHAN_EXTENDED_WRITE, 1394 "client-session", /*nonblock*/0); 1395 1396 debug3("ssh_session2_open: channel_new: %d", c->self); 1397 1398 channel_send_open(c->self); 1399 if (!no_shell_flag) 1400 channel_register_open_confirm(c->self, 1401 ssh_session2_setup, NULL); 1402 1403 return c->self; 1404} 1405 1406static int 1407ssh_session2(void) 1408{ 1409 int id = -1; 1410 1411 /* XXX should be pre-session */ 1412 ssh_init_forwarding(); 1413 1414 /* Start listening for multiplex clients */ 1415 muxserver_listen(); 1416 1417 /* 1418 * If we are in control persist mode, then prepare to background 1419 * ourselves and have a foreground client attach as a control 1420 * slave. NB. we must save copies of the flags that we override for 1421 * the backgrounding, since we defer attachment of the slave until 1422 * after the connection is fully established (in particular, 1423 * async rfwd replies have been received for ExitOnForwardFailure). 1424 */ 1425 if (options.control_persist && muxserver_sock != -1) { 1426 ostdin_null_flag = stdin_null_flag; 1427 ono_shell_flag = no_shell_flag; 1428 orequest_tty = options.request_tty; 1429 otty_flag = tty_flag; 1430 stdin_null_flag = 1; 1431 no_shell_flag = 1; 1432 tty_flag = 0; 1433 if (!fork_after_authentication_flag) 1434 need_controlpersist_detach = 1; 1435 fork_after_authentication_flag = 1; 1436 } 1437 1438 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) 1439 id = ssh_session2_open(); 1440 1441 /* If we don't expect to open a new session, then disallow it */ 1442 if (options.control_master == SSHCTL_MASTER_NO && 1443 (datafellows & SSH_NEW_OPENSSH)) { 1444 debug("Requesting no-more-sessions@openssh.com"); 1445 packet_start(SSH2_MSG_GLOBAL_REQUEST); 1446 packet_put_cstring("no-more-sessions@openssh.com"); 1447 packet_put_char(0); 1448 packet_send(); 1449 } 1450 1451 /* Execute a local command */ 1452 if (options.local_command != NULL && 1453 options.permit_local_command) 1454 ssh_local_cmd(options.local_command); 1455 1456 /* 1457 * If requested and we are not interested in replies to remote 1458 * forwarding requests, then let ssh continue in the background. 1459 */ 1460 if (fork_after_authentication_flag) { 1461 if (options.exit_on_forward_failure && 1462 options.num_remote_forwards > 0) { 1463 debug("deferring postauth fork until remote forward " 1464 "confirmation received"); 1465 } else 1466 fork_postauth(); 1467 } 1468 1469 if (options.use_roaming) 1470 request_roaming(); 1471 1472 return client_loop(tty_flag, tty_flag ? 1473 options.escape_char : SSH_ESCAPECHAR_NONE, id); 1474} 1475 1476static void 1477load_public_identity_files(void) 1478{ 1479 char *filename, *cp, thishost[NI_MAXHOST]; 1480 char *pwdir = NULL, *pwname = NULL; 1481 int i = 0; 1482 Key *public; 1483 struct passwd *pw; 1484 u_int n_ids; 1485 char *identity_files[SSH_MAX_IDENTITY_FILES]; 1486 Key *identity_keys[SSH_MAX_IDENTITY_FILES]; 1487#ifdef ENABLE_PKCS11 1488 Key **keys; 1489 int nkeys; 1490#endif /* PKCS11 */ 1491 1492 n_ids = 0; 1493 bzero(identity_files, sizeof(identity_files)); 1494 bzero(identity_keys, sizeof(identity_keys)); 1495 1496#ifdef ENABLE_PKCS11 1497 if (options.pkcs11_provider != NULL && 1498 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 1499 (pkcs11_init(!options.batch_mode) == 0) && 1500 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 1501 &keys)) > 0) { 1502 for (i = 0; i < nkeys; i++) { 1503 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 1504 key_free(keys[i]); 1505 continue; 1506 } 1507 identity_keys[n_ids] = keys[i]; 1508 identity_files[n_ids] = 1509 xstrdup(options.pkcs11_provider); /* XXX */ 1510 n_ids++; 1511 } 1512 xfree(keys); 1513 } 1514#endif /* ENABLE_PKCS11 */ 1515 if ((pw = getpwuid(original_real_uid)) == NULL) 1516 fatal("load_public_identity_files: getpwuid failed"); 1517 pwname = xstrdup(pw->pw_name); 1518 pwdir = xstrdup(pw->pw_dir); 1519 if (gethostname(thishost, sizeof(thishost)) == -1) 1520 fatal("load_public_identity_files: gethostname: %s", 1521 strerror(errno)); 1522 for (i = 0; i < options.num_identity_files; i++) { 1523 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 1524 xfree(options.identity_files[i]); 1525 continue; 1526 } 1527 cp = tilde_expand_filename(options.identity_files[i], 1528 original_real_uid); 1529 filename = percent_expand(cp, "d", pwdir, 1530 "u", pwname, "l", thishost, "h", host, 1531 "r", options.user, (char *)NULL); 1532 xfree(cp); 1533 public = key_load_public(filename, NULL); 1534 debug("identity file %s type %d", filename, 1535 public ? public->type : -1); 1536 xfree(options.identity_files[i]); 1537 identity_files[n_ids] = filename; 1538 identity_keys[n_ids] = public; 1539 1540 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 1541 continue; 1542 1543 /* Try to add the certificate variant too */ 1544 xasprintf(&cp, "%s-cert", filename); 1545 public = key_load_public(cp, NULL); 1546 debug("identity file %s type %d", cp, 1547 public ? public->type : -1); 1548 if (public == NULL) { 1549 xfree(cp); 1550 continue; 1551 } 1552 if (!key_is_cert(public)) { 1553 debug("%s: key %s type %s is not a certificate", 1554 __func__, cp, key_type(public)); 1555 key_free(public); 1556 xfree(cp); 1557 continue; 1558 } 1559 identity_keys[n_ids] = public; 1560 /* point to the original path, most likely the private key */ 1561 identity_files[n_ids] = xstrdup(filename); 1562 n_ids++; 1563 } 1564 options.num_identity_files = n_ids; 1565 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 1566 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 1567 1568 bzero(pwname, strlen(pwname)); 1569 xfree(pwname); 1570 bzero(pwdir, strlen(pwdir)); 1571 xfree(pwdir); 1572} 1573 1574static void 1575main_sigchld_handler(int sig) 1576{ 1577 int save_errno = errno; 1578 pid_t pid; 1579 int status; 1580 1581 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 1582 (pid < 0 && errno == EINTR)) 1583 ; 1584 1585 signal(sig, main_sigchld_handler); 1586 errno = save_errno; 1587} 1588 1589