1/* $OpenBSD: ssh.c,v 1.373 2013/02/22 22:09:01 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#ifdef __APPLE_CRYPTO__ 75#include "ossl-evp.h" 76#include "ossl-err.h" 77#else 78#include <openssl/evp.h> 79#include <openssl/err.h> 80#endif 81#include "openbsd-compat/openssl-compat.h" 82#include "openbsd-compat/sys-queue.h" 83 84#include "xmalloc.h" 85#include "ssh.h" 86#include "ssh1.h" 87#include "ssh2.h" 88#include "canohost.h" 89#include "compat.h" 90#include "cipher.h" 91#include "packet.h" 92#include "buffer.h" 93#include "channels.h" 94#include "key.h" 95#include "authfd.h" 96#include "authfile.h" 97#include "pathnames.h" 98#include "dispatch.h" 99#include "clientloop.h" 100#include "log.h" 101#include "readconf.h" 102#include "sshconnect.h" 103#include "misc.h" 104#include "kex.h" 105#include "mac.h" 106#include "sshpty.h" 107#include "match.h" 108#include "msg.h" 109#include "uidswap.h" 110#include "roaming.h" 111#include "version.h" 112 113#ifdef ENABLE_PKCS11 114#include "ssh-pkcs11.h" 115#endif 116 117extern char *__progname; 118 119/* Saves a copy of argv for setproctitle emulation */ 120#ifndef HAVE_SETPROCTITLE 121static char **saved_av; 122#endif 123 124/* Flag indicating whether debug mode is on. May be set on the command line. */ 125int debug_flag = 0; 126 127/* Flag indicating whether a tty should be requested */ 128int tty_flag = 0; 129 130/* don't exec a shell */ 131int no_shell_flag = 0; 132 133/* 134 * Flag indicating that nothing should be read from stdin. This can be set 135 * on the command line. 136 */ 137int stdin_null_flag = 0; 138 139/* 140 * Flag indicating that the current process should be backgrounded and 141 * a new slave launched in the foreground for ControlPersist. 142 */ 143int need_controlpersist_detach = 0; 144 145/* Copies of flags for ControlPersist foreground slave */ 146int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty; 147 148/* 149 * Flag indicating that ssh should fork after authentication. This is useful 150 * so that the passphrase can be entered manually, and then ssh goes to the 151 * background. 152 */ 153int fork_after_authentication_flag = 0; 154 155/* forward stdio to remote host and port */ 156char *stdio_forward_host = NULL; 157int stdio_forward_port = 0; 158 159/* 160 * General data structure for command line options and options configurable 161 * in configuration files. See readconf.h. 162 */ 163Options options; 164 165/* optional user configfile */ 166char *config = NULL; 167 168/* 169 * Name of the host we are connecting to. This is the name given on the 170 * command line, or the HostName specified for the user-supplied name in a 171 * configuration file. 172 */ 173char *host; 174 175/* socket address the host resolves to */ 176struct sockaddr_storage hostaddr; 177 178/* Private host keys. */ 179Sensitive sensitive_data; 180 181/* Original real UID. */ 182uid_t original_real_uid; 183uid_t original_effective_uid; 184 185/* command to be executed */ 186Buffer command; 187 188/* Should we execute a command or invoke a subsystem? */ 189int subsystem_flag = 0; 190 191/* # of replies received for global requests */ 192static int remote_forward_confirms_received = 0; 193 194/* mux.c */ 195extern int muxserver_sock; 196extern u_int muxclient_command; 197 198/* Prints a help message to the user. This function never returns. */ 199 200static void 201usage(void) 202{ 203 fprintf(stderr, 204"usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n" 205" [-D [bind_address:]port] [-e escape_char] [-F configfile]\n" 206" [-I pkcs11] [-i identity_file]\n" 207" [-L [bind_address:]port:host:hostport]\n" 208" [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" 209" [-R [bind_address:]port:host:hostport] [-S ctl_path]\n" 210" [-W host:port] [-w local_tun[:remote_tun]]\n" 211" [user@]hostname [command]\n" 212 ); 213 exit(255); 214} 215 216static int ssh_session(void); 217static int ssh_session2(void); 218static void load_public_identity_files(void); 219static void main_sigchld_handler(int); 220 221/* from muxclient.c */ 222void muxclient(const char *); 223void muxserver_listen(void); 224 225/* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 226static void 227tilde_expand_paths(char **paths, u_int num_paths) 228{ 229 u_int i; 230 char *cp; 231 232 for (i = 0; i < num_paths; i++) { 233 cp = tilde_expand_filename(paths[i], original_real_uid); 234 xfree(paths[i]); 235 paths[i] = cp; 236 } 237} 238 239/* 240 * Main program for the ssh client. 241 */ 242int 243main(int ac, char **av) 244{ 245 int i, r, opt, exit_status, use_syslog; 246 char *p, *cp, *line, *argv0, buf[MAXPATHLEN], *host_arg; 247 char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 248 struct stat st; 249 struct passwd *pw; 250 int dummy, timeout_ms; 251 extern int optind, optreset; 252 extern char *optarg; 253 254 struct servent *sp; 255 Forward fwd; 256 257 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 258 sanitise_stdfd(); 259 260 __progname = ssh_get_progname(av[0]); 261 262#ifndef HAVE_SETPROCTITLE 263 /* Prepare for later setproctitle emulation */ 264 /* Save argv so it isn't clobbered by setproctitle() emulation */ 265 saved_av = xcalloc(ac + 1, sizeof(*saved_av)); 266 for (i = 0; i < ac; i++) 267 saved_av[i] = xstrdup(av[i]); 268 saved_av[i] = NULL; 269 compat_init_setproctitle(ac, av); 270 av = saved_av; 271#endif 272 273 /* 274 * Discard other fds that are hanging around. These can cause problem 275 * with backgrounded ssh processes started by ControlPersist. 276 */ 277 closefrom(STDERR_FILENO + 1); 278 279 /* 280 * Save the original real uid. It will be needed later (uid-swapping 281 * may clobber the real uid). 282 */ 283 original_real_uid = getuid(); 284 original_effective_uid = geteuid(); 285 286 /* 287 * Use uid-swapping to give up root privileges for the duration of 288 * option processing. We will re-instantiate the rights when we are 289 * ready to create the privileged port, and will permanently drop 290 * them when the port has been created (actually, when the connection 291 * has been made, as we may need to create the port several times). 292 */ 293 PRIV_END; 294 295#ifdef HAVE_SETRLIMIT 296 /* If we are installed setuid root be careful to not drop core. */ 297 if (original_real_uid != original_effective_uid) { 298 struct rlimit rlim; 299 rlim.rlim_cur = rlim.rlim_max = 0; 300 if (setrlimit(RLIMIT_CORE, &rlim) < 0) 301 fatal("setrlimit failed: %.100s", strerror(errno)); 302 } 303#endif 304 /* Get user data. */ 305 pw = getpwuid(original_real_uid); 306 if (!pw) { 307 logit("You don't exist, go away!"); 308 exit(255); 309 } 310 /* Take a copy of the returned structure. */ 311 pw = pwcopy(pw); 312 313 /* 314 * Set our umask to something reasonable, as some files are created 315 * with the default umask. This will make them world-readable but 316 * writable only by the owner, which is ok for all files for which we 317 * don't set the modes explicitly. 318 */ 319 umask(022); 320 321 /* 322 * Initialize option structure to indicate that no values have been 323 * set. 324 */ 325 initialize_options(&options); 326 327 /* Parse command-line arguments. */ 328 host = NULL; 329 use_syslog = 0; 330 argv0 = av[0]; 331 332 again: 333 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 334 "ACD:F:I:KL:MNO:PR:S:TVw:W:XYy")) != -1) { 335 switch (opt) { 336 case '1': 337 options.protocol = SSH_PROTO_1; 338 break; 339 case '2': 340 options.protocol = SSH_PROTO_2; 341 break; 342 case '4': 343 options.address_family = AF_INET; 344 break; 345 case '6': 346 options.address_family = AF_INET6; 347 break; 348 case 'n': 349 stdin_null_flag = 1; 350 break; 351 case 'f': 352 fork_after_authentication_flag = 1; 353 stdin_null_flag = 1; 354 break; 355 case 'x': 356 options.forward_x11 = 0; 357 break; 358 case 'X': 359 options.forward_x11 = 1; 360 break; 361 case 'y': 362 use_syslog = 1; 363 break; 364 case 'Y': 365 options.forward_x11 = 1; 366 options.forward_x11_trusted = 1; 367 break; 368 case 'g': 369 options.gateway_ports = 1; 370 break; 371 case 'O': 372 if (stdio_forward_host != NULL) 373 fatal("Cannot specify multiplexing " 374 "command with -W"); 375 else if (muxclient_command != 0) 376 fatal("Multiplexing command already specified"); 377 if (strcmp(optarg, "check") == 0) 378 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 379 else if (strcmp(optarg, "forward") == 0) 380 muxclient_command = SSHMUX_COMMAND_FORWARD; 381 else if (strcmp(optarg, "exit") == 0) 382 muxclient_command = SSHMUX_COMMAND_TERMINATE; 383 else if (strcmp(optarg, "stop") == 0) 384 muxclient_command = SSHMUX_COMMAND_STOP; 385 else if (strcmp(optarg, "cancel") == 0) 386 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 387 else 388 fatal("Invalid multiplex command."); 389 break; 390 case 'P': /* deprecated */ 391 options.use_privileged_port = 0; 392 break; 393 case 'a': 394 options.forward_agent = 0; 395 break; 396 case 'A': 397 options.forward_agent = 1; 398 break; 399 case 'k': 400 options.gss_deleg_creds = 0; 401 break; 402 case 'K': 403 options.gss_authentication = 1; 404 options.gss_deleg_creds = 1; 405 break; 406 case 'i': 407 if (stat(optarg, &st) < 0) { 408 fprintf(stderr, "Warning: Identity file %s " 409 "not accessible: %s.\n", optarg, 410 strerror(errno)); 411 break; 412 } 413 add_identity_file(&options, NULL, optarg, 1); 414 break; 415 case 'I': 416#ifdef ENABLE_PKCS11 417 options.pkcs11_provider = xstrdup(optarg); 418#else 419 fprintf(stderr, "no support for PKCS#11.\n"); 420#endif 421 break; 422 case 't': 423 if (options.request_tty == REQUEST_TTY_YES) 424 options.request_tty = REQUEST_TTY_FORCE; 425 else 426 options.request_tty = REQUEST_TTY_YES; 427 break; 428 case 'v': 429 if (debug_flag == 0) { 430 debug_flag = 1; 431 options.log_level = SYSLOG_LEVEL_DEBUG1; 432 } else { 433 if (options.log_level < SYSLOG_LEVEL_DEBUG3) 434 options.log_level++; 435 break; 436 } 437 /* FALLTHROUGH */ 438 case 'V': 439 fprintf(stderr, "%s, %s\n", 440 SSH_RELEASE, SSLeay_version(SSLEAY_VERSION)); 441 if (opt == 'V') 442 exit(0); 443 break; 444 case 'w': 445 if (options.tun_open == -1) 446 options.tun_open = SSH_TUNMODE_DEFAULT; 447 options.tun_local = a2tun(optarg, &options.tun_remote); 448 if (options.tun_local == SSH_TUNID_ERR) { 449 fprintf(stderr, 450 "Bad tun device '%s'\n", optarg); 451 exit(255); 452 } 453 break; 454 case 'W': 455 if (stdio_forward_host != NULL) 456 fatal("stdio forward already specified"); 457 if (muxclient_command != 0) 458 fatal("Cannot specify stdio forward with -O"); 459 if (parse_forward(&fwd, optarg, 1, 0)) { 460 stdio_forward_host = fwd.listen_host; 461 stdio_forward_port = fwd.listen_port; 462 xfree(fwd.connect_host); 463 } else { 464 fprintf(stderr, 465 "Bad stdio forwarding specification '%s'\n", 466 optarg); 467 exit(255); 468 } 469 options.request_tty = REQUEST_TTY_NO; 470 no_shell_flag = 1; 471 options.clear_forwardings = 1; 472 options.exit_on_forward_failure = 1; 473 break; 474 case 'q': 475 options.log_level = SYSLOG_LEVEL_QUIET; 476 break; 477 case 'e': 478 if (optarg[0] == '^' && optarg[2] == 0 && 479 (u_char) optarg[1] >= 64 && 480 (u_char) optarg[1] < 128) 481 options.escape_char = (u_char) optarg[1] & 31; 482 else if (strlen(optarg) == 1) 483 options.escape_char = (u_char) optarg[0]; 484 else if (strcmp(optarg, "none") == 0) 485 options.escape_char = SSH_ESCAPECHAR_NONE; 486 else { 487 fprintf(stderr, "Bad escape character '%s'.\n", 488 optarg); 489 exit(255); 490 } 491 break; 492 case 'c': 493 if (ciphers_valid(optarg)) { 494 /* SSH2 only */ 495 options.ciphers = xstrdup(optarg); 496 options.cipher = SSH_CIPHER_INVALID; 497 } else { 498 /* SSH1 only */ 499 options.cipher = cipher_number(optarg); 500 if (options.cipher == -1) { 501 fprintf(stderr, 502 "Unknown cipher type '%s'\n", 503 optarg); 504 exit(255); 505 } 506 if (options.cipher == SSH_CIPHER_3DES) 507 options.ciphers = "3des-cbc"; 508 else if (options.cipher == SSH_CIPHER_BLOWFISH) 509 options.ciphers = "blowfish-cbc"; 510 else 511 options.ciphers = (char *)-1; 512 } 513 break; 514 case 'm': 515 if (mac_valid(optarg)) 516 options.macs = xstrdup(optarg); 517 else { 518 fprintf(stderr, "Unknown mac type '%s'\n", 519 optarg); 520 exit(255); 521 } 522 break; 523 case 'M': 524 if (options.control_master == SSHCTL_MASTER_YES) 525 options.control_master = SSHCTL_MASTER_ASK; 526 else 527 options.control_master = SSHCTL_MASTER_YES; 528 break; 529 case 'p': 530 options.port = a2port(optarg); 531 if (options.port <= 0) { 532 fprintf(stderr, "Bad port '%s'\n", optarg); 533 exit(255); 534 } 535 break; 536 case 'l': 537 options.user = optarg; 538 break; 539 540 case 'L': 541 if (parse_forward(&fwd, optarg, 0, 0)) 542 add_local_forward(&options, &fwd); 543 else { 544 fprintf(stderr, 545 "Bad local forwarding specification '%s'\n", 546 optarg); 547 exit(255); 548 } 549 break; 550 551 case 'R': 552 if (parse_forward(&fwd, optarg, 0, 1)) { 553 add_remote_forward(&options, &fwd); 554 } else { 555 fprintf(stderr, 556 "Bad remote forwarding specification " 557 "'%s'\n", optarg); 558 exit(255); 559 } 560 break; 561 562 case 'D': 563 if (parse_forward(&fwd, optarg, 1, 0)) { 564 add_local_forward(&options, &fwd); 565 } else { 566 fprintf(stderr, 567 "Bad dynamic forwarding specification " 568 "'%s'\n", optarg); 569 exit(255); 570 } 571 break; 572 573 case 'C': 574 options.compression = 1; 575 break; 576 case 'N': 577 no_shell_flag = 1; 578 options.request_tty = REQUEST_TTY_NO; 579 break; 580 case 'T': 581 options.request_tty = REQUEST_TTY_NO; 582 break; 583 case 'o': 584 dummy = 1; 585 line = xstrdup(optarg); 586 if (process_config_line(&options, host ? host : "", 587 line, "command-line", 0, &dummy, SSHCONF_USERCONF) 588 != 0) 589 exit(255); 590 xfree(line); 591 break; 592 case 's': 593 subsystem_flag = 1; 594 break; 595 case 'S': 596 if (options.control_path != NULL) 597 free(options.control_path); 598 options.control_path = xstrdup(optarg); 599 break; 600 case 'b': 601 options.bind_address = optarg; 602 break; 603 case 'F': 604 config = optarg; 605 break; 606 default: 607 usage(); 608 } 609 } 610 611 ac -= optind; 612 av += optind; 613 614 if (ac > 0 && !host) { 615 if (strrchr(*av, '@')) { 616 p = xstrdup(*av); 617 cp = strrchr(p, '@'); 618 if (cp == NULL || cp == p) 619 usage(); 620 options.user = p; 621 *cp = '\0'; 622 host = ++cp; 623 } else 624 host = *av; 625 if (ac > 1) { 626 optind = optreset = 1; 627 goto again; 628 } 629 ac--, av++; 630 } 631 632 /* Check that we got a host name. */ 633 if (!host) 634 usage(); 635 636 OpenSSL_add_all_algorithms(); 637 ERR_load_crypto_strings(); 638 639 /* Initialize the command to execute on remote host. */ 640 buffer_init(&command); 641 642 /* 643 * Save the command to execute on the remote host in a buffer. There 644 * is no limit on the length of the command, except by the maximum 645 * packet size. Also sets the tty flag if there is no command. 646 */ 647 if (!ac) { 648 /* No command specified - execute shell on a tty. */ 649 if (subsystem_flag) { 650 fprintf(stderr, 651 "You must specify a subsystem to invoke.\n"); 652 usage(); 653 } 654 } else { 655 /* A command has been specified. Store it into the buffer. */ 656 for (i = 0; i < ac; i++) { 657 if (i) 658 buffer_append(&command, " ", 1); 659 buffer_append(&command, av[i], strlen(av[i])); 660 } 661 } 662 663 /* Cannot fork to background if no command. */ 664 if (fork_after_authentication_flag && buffer_len(&command) == 0 && 665 !no_shell_flag) 666 fatal("Cannot fork into background without a command " 667 "to execute."); 668 669 /* 670 * Initialize "log" output. Since we are the client all output 671 * actually goes to stderr. 672 */ 673 log_init(argv0, 674 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, 675 SYSLOG_FACILITY_USER, !use_syslog); 676 677 /* 678 * Read per-user configuration file. Ignore the system wide config 679 * file if the user specifies a config file on the command line. 680 */ 681 if (config != NULL) { 682 if (!read_config_file(config, host, &options, SSHCONF_USERCONF)) 683 fatal("Can't open user config file %.100s: " 684 "%.100s", config, strerror(errno)); 685 } else { 686 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 687 _PATH_SSH_USER_CONFFILE); 688 if (r > 0 && (size_t)r < sizeof(buf)) 689 (void)read_config_file(buf, host, &options, 690 SSHCONF_CHECKPERM|SSHCONF_USERCONF); 691 692 /* Read systemwide configuration file after user config. */ 693 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, 694 &options, 0); 695 } 696 697 /* Fill configuration defaults. */ 698 fill_default_options(&options); 699 700 channel_set_af(options.address_family); 701 702 /* reinit */ 703 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog); 704 705 if (options.request_tty == REQUEST_TTY_YES || 706 options.request_tty == REQUEST_TTY_FORCE) 707 tty_flag = 1; 708 709 /* Allocate a tty by default if no command specified. */ 710 if (buffer_len(&command) == 0) 711 tty_flag = options.request_tty != REQUEST_TTY_NO; 712 713 /* Force no tty */ 714 if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0) 715 tty_flag = 0; 716 /* Do not allocate a tty if stdin is not a tty. */ 717 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 718 options.request_tty != REQUEST_TTY_FORCE) { 719 if (tty_flag) 720 logit("Pseudo-terminal will not be allocated because " 721 "stdin is not a terminal."); 722 tty_flag = 0; 723 } 724 725 seed_rng(); 726 727 if (options.user == NULL) 728 options.user = xstrdup(pw->pw_name); 729 730 /* Get default port if port has not been set. */ 731 if (options.port == 0) { 732 sp = getservbyname(SSH_SERVICE_NAME, "tcp"); 733 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT; 734 } 735 736 /* preserve host name given on command line for %n expansion */ 737 host_arg = host; 738 if (options.hostname != NULL) { 739 host = percent_expand(options.hostname, 740 "h", host, (char *)NULL); 741 } 742 743 if (gethostname(thishost, sizeof(thishost)) == -1) 744 fatal("gethostname: %s", strerror(errno)); 745 strlcpy(shorthost, thishost, sizeof(shorthost)); 746 shorthost[strcspn(thishost, ".")] = '\0'; 747 snprintf(portstr, sizeof(portstr), "%d", options.port); 748 749 if (options.local_command != NULL) { 750 debug3("expanding LocalCommand: %s", options.local_command); 751 cp = options.local_command; 752 options.local_command = percent_expand(cp, "d", pw->pw_dir, 753 "h", host, "l", thishost, "n", host_arg, "r", options.user, 754 "p", portstr, "u", pw->pw_name, "L", shorthost, 755 (char *)NULL); 756 debug3("expanded LocalCommand: %s", options.local_command); 757 xfree(cp); 758 } 759 760 /* force lowercase for hostkey matching */ 761 if (options.host_key_alias != NULL) { 762 for (p = options.host_key_alias; *p; p++) 763 if (isupper(*p)) 764 *p = (char)tolower(*p); 765 } 766 767 if (options.proxy_command != NULL && 768 strcmp(options.proxy_command, "none") == 0) { 769 xfree(options.proxy_command); 770 options.proxy_command = NULL; 771 } 772 if (options.control_path != NULL && 773 strcmp(options.control_path, "none") == 0) { 774 xfree(options.control_path); 775 options.control_path = NULL; 776 } 777 778 if (options.control_path != NULL) { 779 cp = tilde_expand_filename(options.control_path, 780 original_real_uid); 781 xfree(options.control_path); 782 options.control_path = percent_expand(cp, "h", host, 783 "l", thishost, "n", host_arg, "r", options.user, 784 "p", portstr, "u", pw->pw_name, "L", shorthost, 785 (char *)NULL); 786 xfree(cp); 787 } 788 if (muxclient_command != 0 && options.control_path == NULL) 789 fatal("No ControlPath specified for \"-O\" command"); 790 if (options.control_path != NULL) 791 muxclient(options.control_path); 792 793 timeout_ms = options.connection_timeout * 1000; 794 795 /* Open a connection to the remote host. */ 796 if (ssh_connect(host, &hostaddr, options.port, 797 options.address_family, options.connection_attempts, &timeout_ms, 798 options.tcp_keep_alive, 799#ifdef HAVE_CYGWIN 800 options.use_privileged_port, 801#else 802 original_effective_uid == 0 && options.use_privileged_port, 803#endif 804 options.proxy_command) != 0) 805 exit(255); 806 807 if (timeout_ms > 0) 808 debug3("timeout: %d ms remain after connect", timeout_ms); 809 810 /* 811 * If we successfully made the connection, load the host private key 812 * in case we will need it later for combined rsa-rhosts 813 * authentication. This must be done before releasing extra 814 * privileges, because the file is only readable by root. 815 * If we cannot access the private keys, load the public keys 816 * instead and try to execute the ssh-keysign helper instead. 817 */ 818 sensitive_data.nkeys = 0; 819 sensitive_data.keys = NULL; 820 sensitive_data.external_keysign = 0; 821 if (options.rhosts_rsa_authentication || 822 options.hostbased_authentication) { 823 sensitive_data.nkeys = 7; 824 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 825 sizeof(Key)); 826 for (i = 0; i < sensitive_data.nkeys; i++) 827 sensitive_data.keys[i] = NULL; 828 829 PRIV_START; 830 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, 831 _PATH_HOST_KEY_FILE, "", NULL, NULL); 832 sensitive_data.keys[1] = key_load_private_cert(KEY_DSA, 833 _PATH_HOST_DSA_KEY_FILE, "", NULL); 834#ifdef OPENSSL_HAS_ECC 835 sensitive_data.keys[2] = key_load_private_cert(KEY_ECDSA, 836 _PATH_HOST_ECDSA_KEY_FILE, "", NULL); 837#endif 838 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA, 839 _PATH_HOST_RSA_KEY_FILE, "", NULL); 840 sensitive_data.keys[4] = key_load_private_type(KEY_DSA, 841 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); 842#ifdef OPENSSL_HAS_ECC 843 sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA, 844 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL); 845#endif 846 sensitive_data.keys[6] = key_load_private_type(KEY_RSA, 847 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); 848 PRIV_END; 849 850 if (options.hostbased_authentication == 1 && 851 sensitive_data.keys[0] == NULL && 852 sensitive_data.keys[4] == NULL && 853 sensitive_data.keys[5] == NULL && 854 sensitive_data.keys[6] == NULL) { 855 sensitive_data.keys[1] = key_load_cert( 856 _PATH_HOST_DSA_KEY_FILE); 857#ifdef OPENSSL_HAS_ECC 858 sensitive_data.keys[2] = key_load_cert( 859 _PATH_HOST_ECDSA_KEY_FILE); 860#endif 861 sensitive_data.keys[3] = key_load_cert( 862 _PATH_HOST_RSA_KEY_FILE); 863 sensitive_data.keys[4] = key_load_public( 864 _PATH_HOST_DSA_KEY_FILE, NULL); 865#ifdef OPENSSL_HAS_ECC 866 sensitive_data.keys[5] = key_load_public( 867 _PATH_HOST_ECDSA_KEY_FILE, NULL); 868#endif 869 sensitive_data.keys[6] = key_load_public( 870 _PATH_HOST_RSA_KEY_FILE, NULL); 871 sensitive_data.external_keysign = 1; 872 } 873 } 874 /* 875 * Get rid of any extra privileges that we may have. We will no 876 * longer need them. Also, extra privileges could make it very hard 877 * to read identity files and other non-world-readable files from the 878 * user's home directory if it happens to be on a NFS volume where 879 * root is mapped to nobody. 880 */ 881 if (original_effective_uid == 0) { 882 PRIV_START; 883 permanently_set_uid(pw); 884 } 885 886 /* 887 * Now that we are back to our own permissions, create ~/.ssh 888 * directory if it doesn't already exist. 889 */ 890 if (config == NULL) { 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'.", 899 buf); 900#ifdef WITH_SELINUX 901 ssh_selinux_setfscreatecon(NULL); 902#endif 903 } 904 } 905 /* load options.identity_files */ 906 load_public_identity_files(); 907 908 /* Expand ~ in known host file names. */ 909 tilde_expand_paths(options.system_hostfiles, 910 options.num_system_hostfiles); 911 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 912 913 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 914 signal(SIGCHLD, main_sigchld_handler); 915 916 /* Log into the remote system. Never returns if the login fails. */ 917 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, 918 options.port, pw, timeout_ms); 919 920 if (packet_connection_is_on_socket()) { 921 verbose("Authenticated to %s ([%s]:%d).", host, 922 get_remote_ipaddr(), get_remote_port()); 923 } else { 924 verbose("Authenticated to %s (via proxy).", host); 925 } 926 927 /* We no longer need the private host keys. Clear them now. */ 928 if (sensitive_data.nkeys != 0) { 929 for (i = 0; i < sensitive_data.nkeys; i++) { 930 if (sensitive_data.keys[i] != NULL) { 931 /* Destroys contents safely */ 932 debug3("clear hostkey %d", i); 933 key_free(sensitive_data.keys[i]); 934 sensitive_data.keys[i] = NULL; 935 } 936 } 937 xfree(sensitive_data.keys); 938 } 939 for (i = 0; i < options.num_identity_files; i++) { 940 if (options.identity_files[i]) { 941 xfree(options.identity_files[i]); 942 options.identity_files[i] = NULL; 943 } 944 if (options.identity_keys[i]) { 945 key_free(options.identity_keys[i]); 946 options.identity_keys[i] = NULL; 947 } 948 } 949 950 exit_status = compat20 ? ssh_session2() : ssh_session(); 951 packet_close(); 952 953 if (options.control_path != NULL && muxserver_sock != -1) 954 unlink(options.control_path); 955 956 /* Kill ProxyCommand if it is running. */ 957 ssh_kill_proxy_command(); 958 959 return exit_status; 960} 961 962static void 963control_persist_detach(void) 964{ 965 pid_t pid; 966 int devnull; 967 968 debug("%s: backgrounding master process", __func__); 969 970 /* 971 * master (current process) into the background, and make the 972 * foreground process a client of the backgrounded master. 973 */ 974 switch ((pid = fork())) { 975 case -1: 976 fatal("%s: fork: %s", __func__, strerror(errno)); 977 case 0: 978 /* Child: master process continues mainloop */ 979 break; 980 default: 981 /* Parent: set up mux slave to connect to backgrounded master */ 982 debug2("%s: background process is %ld", __func__, (long)pid); 983 stdin_null_flag = ostdin_null_flag; 984 options.request_tty = orequest_tty; 985 tty_flag = otty_flag; 986 close(muxserver_sock); 987 muxserver_sock = -1; 988 options.control_master = SSHCTL_MASTER_NO; 989 muxclient(options.control_path); 990 /* muxclient() doesn't return on success. */ 991 fatal("Failed to connect to new control master"); 992 } 993 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 994 error("%s: open(\"/dev/null\"): %s", __func__, 995 strerror(errno)); 996 } else { 997 if (dup2(devnull, STDIN_FILENO) == -1 || 998 dup2(devnull, STDOUT_FILENO) == -1) 999 error("%s: dup2: %s", __func__, strerror(errno)); 1000 if (devnull > STDERR_FILENO) 1001 close(devnull); 1002 } 1003 setproctitle("%s [mux]", options.control_path); 1004} 1005 1006/* Do fork() after authentication. Used by "ssh -f" */ 1007static void 1008fork_postauth(void) 1009{ 1010 if (need_controlpersist_detach) 1011 control_persist_detach(); 1012 debug("forking to background"); 1013 fork_after_authentication_flag = 0; 1014 if (daemon(1, 1) < 0) 1015 fatal("daemon() failed: %.200s", strerror(errno)); 1016} 1017 1018/* Callback for remote forward global requests */ 1019static void 1020ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) 1021{ 1022 Forward *rfwd = (Forward *)ctxt; 1023 1024 /* XXX verbose() on failure? */ 1025 debug("remote forward %s for: listen %d, connect %s:%d", 1026 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1027 rfwd->listen_port, rfwd->connect_host, rfwd->connect_port); 1028 if (rfwd->listen_port == 0) { 1029 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1030 rfwd->allocated_port = packet_get_int(); 1031 logit("Allocated port %u for remote forward to %s:%d", 1032 rfwd->allocated_port, 1033 rfwd->connect_host, rfwd->connect_port); 1034 channel_update_permitted_opens(rfwd->handle, 1035 rfwd->allocated_port); 1036 } else { 1037 channel_update_permitted_opens(rfwd->handle, -1); 1038 } 1039 } 1040 1041 if (type == SSH2_MSG_REQUEST_FAILURE) { 1042 if (options.exit_on_forward_failure) 1043 fatal("Error: remote port forwarding failed for " 1044 "listen port %d", rfwd->listen_port); 1045 else 1046 logit("Warning: remote port forwarding failed for " 1047 "listen port %d", rfwd->listen_port); 1048 } 1049 if (++remote_forward_confirms_received == options.num_remote_forwards) { 1050 debug("All remote forwarding requests processed"); 1051 if (fork_after_authentication_flag) 1052 fork_postauth(); 1053 } 1054} 1055 1056static void 1057client_cleanup_stdio_fwd(int id, void *arg) 1058{ 1059 debug("stdio forwarding: done"); 1060 cleanup_exit(0); 1061} 1062 1063static void 1064ssh_init_stdio_forwarding(void) 1065{ 1066 Channel *c; 1067 int in, out; 1068 1069 if (stdio_forward_host == NULL) 1070 return; 1071 if (!compat20) 1072 fatal("stdio forwarding require Protocol 2"); 1073 1074 debug3("%s: %s:%d", __func__, stdio_forward_host, stdio_forward_port); 1075 1076 if ((in = dup(STDIN_FILENO)) < 0 || 1077 (out = dup(STDOUT_FILENO)) < 0) 1078 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1079 if ((c = channel_connect_stdio_fwd(stdio_forward_host, 1080 stdio_forward_port, in, out)) == NULL) 1081 fatal("%s: channel_connect_stdio_fwd failed", __func__); 1082 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0); 1083} 1084 1085static void 1086ssh_init_forwarding(void) 1087{ 1088 int success = 0; 1089 int i; 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 options.remote_forwards[i].handle = 1123 channel_request_remote_forwarding( 1124 options.remote_forwards[i].listen_host, 1125 options.remote_forwards[i].listen_port, 1126 options.remote_forwards[i].connect_host, 1127 options.remote_forwards[i].connect_port); 1128 if (options.remote_forwards[i].handle < 0) { 1129 if (options.exit_on_forward_failure) 1130 fatal("Could not request remote forwarding."); 1131 else 1132 logit("Warning: Could not request remote " 1133 "forwarding."); 1134 } else { 1135 client_register_global_confirm(ssh_confirm_remote_forward, 1136 &options.remote_forwards[i]); 1137 } 1138 } 1139 1140 /* Initiate tunnel forwarding. */ 1141 if (options.tun_open != SSH_TUNMODE_NO) { 1142 if (client_request_tun_fwd(options.tun_open, 1143 options.tun_local, options.tun_remote) == -1) { 1144 if (options.exit_on_forward_failure) 1145 fatal("Could not request tunnel forwarding."); 1146 else 1147 error("Could not request tunnel forwarding."); 1148 } 1149 } 1150} 1151 1152static void 1153check_agent_present(void) 1154{ 1155 if (options.forward_agent) { 1156 /* Clear agent forwarding if we don't have an agent. */ 1157 if (!ssh_agent_present()) 1158 options.forward_agent = 0; 1159 } 1160} 1161 1162static int 1163ssh_session(void) 1164{ 1165 int type; 1166 int interactive = 0; 1167 int have_tty = 0; 1168 struct winsize ws; 1169 char *cp; 1170 const char *display; 1171 1172 /* Enable compression if requested. */ 1173 if (options.compression) { 1174 debug("Requesting compression at level %d.", 1175 options.compression_level); 1176 1177 if (options.compression_level < 1 || 1178 options.compression_level > 9) 1179 fatal("Compression level must be from 1 (fast) to " 1180 "9 (slow, best)."); 1181 1182 /* Send the request. */ 1183 packet_start(SSH_CMSG_REQUEST_COMPRESSION); 1184 packet_put_int(options.compression_level); 1185 packet_send(); 1186 packet_write_wait(); 1187 type = packet_read(); 1188 if (type == SSH_SMSG_SUCCESS) 1189 packet_start_compression(options.compression_level); 1190 else if (type == SSH_SMSG_FAILURE) 1191 logit("Warning: Remote host refused compression."); 1192 else 1193 packet_disconnect("Protocol error waiting for " 1194 "compression response."); 1195 } 1196 /* Allocate a pseudo tty if appropriate. */ 1197 if (tty_flag) { 1198 debug("Requesting pty."); 1199 1200 /* Start the packet. */ 1201 packet_start(SSH_CMSG_REQUEST_PTY); 1202 1203 /* Store TERM in the packet. There is no limit on the 1204 length of the string. */ 1205 cp = getenv("TERM"); 1206 if (!cp) 1207 cp = ""; 1208 packet_put_cstring(cp); 1209 1210 /* Store window size in the packet. */ 1211 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 1212 memset(&ws, 0, sizeof(ws)); 1213 packet_put_int((u_int)ws.ws_row); 1214 packet_put_int((u_int)ws.ws_col); 1215 packet_put_int((u_int)ws.ws_xpixel); 1216 packet_put_int((u_int)ws.ws_ypixel); 1217 1218 /* Store tty modes in the packet. */ 1219 tty_make_modes(fileno(stdin), NULL); 1220 1221 /* Send the packet, and wait for it to leave. */ 1222 packet_send(); 1223 packet_write_wait(); 1224 1225 /* Read response from the server. */ 1226 type = packet_read(); 1227 if (type == SSH_SMSG_SUCCESS) { 1228 interactive = 1; 1229 have_tty = 1; 1230 } else if (type == SSH_SMSG_FAILURE) 1231 logit("Warning: Remote host failed or refused to " 1232 "allocate a pseudo tty."); 1233 else 1234 packet_disconnect("Protocol error waiting for pty " 1235 "request response."); 1236 } 1237 /* Request X11 forwarding if enabled and DISPLAY is set. */ 1238 display = getenv("DISPLAY"); 1239 if (options.forward_x11 && display != NULL) { 1240 char *proto, *data; 1241 /* Get reasonable local authentication information. */ 1242 client_x11_get_proto(display, options.xauth_location, 1243 options.forward_x11_trusted, 1244 options.forward_x11_timeout, 1245 &proto, &data); 1246 /* Request forwarding with authentication spoofing. */ 1247 debug("Requesting X11 forwarding with authentication " 1248 "spoofing."); 1249 x11_request_forwarding_with_spoofing(0, display, proto, 1250 data, 0); 1251 /* Read response from the server. */ 1252 type = packet_read(); 1253 if (type == SSH_SMSG_SUCCESS) { 1254 interactive = 1; 1255 } else if (type == SSH_SMSG_FAILURE) { 1256 logit("Warning: Remote host denied X11 forwarding."); 1257 } else { 1258 packet_disconnect("Protocol error waiting for X11 " 1259 "forwarding"); 1260 } 1261 } 1262 /* Tell the packet module whether this is an interactive session. */ 1263 packet_set_interactive(interactive, 1264 options.ip_qos_interactive, options.ip_qos_bulk); 1265 1266 /* Request authentication agent forwarding if appropriate. */ 1267 check_agent_present(); 1268 1269 if (options.forward_agent) { 1270 debug("Requesting authentication agent forwarding."); 1271 auth_request_forwarding(); 1272 1273 /* Read response from the server. */ 1274 type = packet_read(); 1275 packet_check_eom(); 1276 if (type != SSH_SMSG_SUCCESS) 1277 logit("Warning: Remote host denied authentication agent forwarding."); 1278 } 1279 1280 /* Initiate port forwardings. */ 1281 ssh_init_stdio_forwarding(); 1282 ssh_init_forwarding(); 1283 1284 /* Execute a local command */ 1285 if (options.local_command != NULL && 1286 options.permit_local_command) 1287 ssh_local_cmd(options.local_command); 1288 1289 /* 1290 * If requested and we are not interested in replies to remote 1291 * forwarding requests, then let ssh continue in the background. 1292 */ 1293 if (fork_after_authentication_flag) { 1294 if (options.exit_on_forward_failure && 1295 options.num_remote_forwards > 0) { 1296 debug("deferring postauth fork until remote forward " 1297 "confirmation received"); 1298 } else 1299 fork_postauth(); 1300 } 1301 1302 /* 1303 * If a command was specified on the command line, execute the 1304 * command now. Otherwise request the server to start a shell. 1305 */ 1306 if (buffer_len(&command) > 0) { 1307 int len = buffer_len(&command); 1308 if (len > 900) 1309 len = 900; 1310 debug("Sending command: %.*s", len, 1311 (u_char *)buffer_ptr(&command)); 1312 packet_start(SSH_CMSG_EXEC_CMD); 1313 packet_put_string(buffer_ptr(&command), buffer_len(&command)); 1314 packet_send(); 1315 packet_write_wait(); 1316 } else { 1317 debug("Requesting shell."); 1318 packet_start(SSH_CMSG_EXEC_SHELL); 1319 packet_send(); 1320 packet_write_wait(); 1321 } 1322 1323 /* Enter the interactive session. */ 1324 return client_loop(have_tty, tty_flag ? 1325 options.escape_char : SSH_ESCAPECHAR_NONE, 0); 1326} 1327 1328/* request pty/x11/agent/tcpfwd/shell for channel */ 1329static void 1330ssh_session2_setup(int id, int success, void *arg) 1331{ 1332 extern char **environ; 1333 const char *display; 1334 int interactive = tty_flag; 1335 1336 if (!success) 1337 return; /* No need for error message, channels code sens one */ 1338 1339 display = getenv("DISPLAY"); 1340 if (options.forward_x11 && display != NULL) { 1341 char *proto, *data; 1342 /* Get reasonable local authentication information. */ 1343 client_x11_get_proto(display, options.xauth_location, 1344 options.forward_x11_trusted, 1345 options.forward_x11_timeout, &proto, &data); 1346 /* Request forwarding with authentication spoofing. */ 1347 debug("Requesting X11 forwarding with authentication " 1348 "spoofing."); 1349 x11_request_forwarding_with_spoofing(id, display, proto, 1350 data, 1); 1351 client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN); 1352 /* XXX exit_on_forward_failure */ 1353 interactive = 1; 1354 } 1355 1356 check_agent_present(); 1357 if (options.forward_agent) { 1358 debug("Requesting authentication agent forwarding."); 1359 channel_request_start(id, "auth-agent-req@openssh.com", 0); 1360 packet_send(); 1361 } 1362 1363 /* Tell the packet module whether this is an interactive session. */ 1364 packet_set_interactive(interactive, 1365 options.ip_qos_interactive, options.ip_qos_bulk); 1366 1367 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), 1368 NULL, fileno(stdin), &command, environ); 1369} 1370 1371/* open new channel for a session */ 1372static int 1373ssh_session2_open(void) 1374{ 1375 Channel *c; 1376 int window, packetmax, in, out, err; 1377 1378 if (stdin_null_flag) { 1379 in = open(_PATH_DEVNULL, O_RDONLY); 1380 } else { 1381 in = dup(STDIN_FILENO); 1382 } 1383 out = dup(STDOUT_FILENO); 1384 err = dup(STDERR_FILENO); 1385 1386 if (in < 0 || out < 0 || err < 0) 1387 fatal("dup() in/out/err failed"); 1388 1389 /* enable nonblocking unless tty */ 1390 if (!isatty(in)) 1391 set_nonblock(in); 1392 if (!isatty(out)) 1393 set_nonblock(out); 1394 if (!isatty(err)) 1395 set_nonblock(err); 1396 1397 window = CHAN_SES_WINDOW_DEFAULT; 1398 packetmax = CHAN_SES_PACKET_DEFAULT; 1399 if (tty_flag) { 1400 window >>= 1; 1401 packetmax >>= 1; 1402 } 1403 c = channel_new( 1404 "session", SSH_CHANNEL_OPENING, in, out, err, 1405 window, packetmax, CHAN_EXTENDED_WRITE, 1406 "client-session", /*nonblock*/0); 1407 1408 debug3("ssh_session2_open: channel_new: %d", c->self); 1409 1410 channel_send_open(c->self); 1411 if (!no_shell_flag) 1412 channel_register_open_confirm(c->self, 1413 ssh_session2_setup, NULL); 1414 1415 return c->self; 1416} 1417 1418static int 1419ssh_session2(void) 1420{ 1421 int id = -1; 1422 1423 /* XXX should be pre-session */ 1424 if (!options.control_persist) 1425 ssh_init_stdio_forwarding(); 1426 ssh_init_forwarding(); 1427 1428 /* Start listening for multiplex clients */ 1429 muxserver_listen(); 1430 1431 /* 1432 * If we are in control persist mode and have a working mux listen 1433 * socket, then prepare to background ourselves and have a foreground 1434 * client attach as a control slave. 1435 * NB. we must save copies of the flags that we override for 1436 * the backgrounding, since we defer attachment of the slave until 1437 * after the connection is fully established (in particular, 1438 * async rfwd replies have been received for ExitOnForwardFailure). 1439 */ 1440 if (options.control_persist && muxserver_sock != -1) { 1441 ostdin_null_flag = stdin_null_flag; 1442 ono_shell_flag = no_shell_flag; 1443 orequest_tty = options.request_tty; 1444 otty_flag = tty_flag; 1445 stdin_null_flag = 1; 1446 no_shell_flag = 1; 1447 tty_flag = 0; 1448 if (!fork_after_authentication_flag) 1449 need_controlpersist_detach = 1; 1450 fork_after_authentication_flag = 1; 1451 } 1452 /* 1453 * ControlPersist mux listen socket setup failed, attempt the 1454 * stdio forward setup that we skipped earlier. 1455 */ 1456 if (options.control_persist && muxserver_sock == -1) 1457 ssh_init_stdio_forwarding(); 1458 1459 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) 1460 id = ssh_session2_open(); 1461 1462 /* If we don't expect to open a new session, then disallow it */ 1463 if (options.control_master == SSHCTL_MASTER_NO && 1464 (datafellows & SSH_NEW_OPENSSH)) { 1465 debug("Requesting no-more-sessions@openssh.com"); 1466 packet_start(SSH2_MSG_GLOBAL_REQUEST); 1467 packet_put_cstring("no-more-sessions@openssh.com"); 1468 packet_put_char(0); 1469 packet_send(); 1470 } 1471 1472 /* Execute a local command */ 1473 if (options.local_command != NULL && 1474 options.permit_local_command) 1475 ssh_local_cmd(options.local_command); 1476 1477 /* 1478 * If requested and we are not interested in replies to remote 1479 * forwarding requests, then let ssh continue in the background. 1480 */ 1481 if (fork_after_authentication_flag) { 1482 if (options.exit_on_forward_failure && 1483 options.num_remote_forwards > 0) { 1484 debug("deferring postauth fork until remote forward " 1485 "confirmation received"); 1486 } else 1487 fork_postauth(); 1488 } 1489 1490 if (options.use_roaming) 1491 request_roaming(); 1492 1493 return client_loop(tty_flag, tty_flag ? 1494 options.escape_char : SSH_ESCAPECHAR_NONE, id); 1495} 1496 1497static void 1498load_public_identity_files(void) 1499{ 1500 char *filename, *cp, thishost[NI_MAXHOST]; 1501 char *pwdir = NULL, *pwname = NULL; 1502 int i = 0; 1503 Key *public; 1504 struct passwd *pw; 1505 u_int n_ids; 1506 char *identity_files[SSH_MAX_IDENTITY_FILES]; 1507 Key *identity_keys[SSH_MAX_IDENTITY_FILES]; 1508#ifdef ENABLE_PKCS11 1509 Key **keys; 1510 int nkeys; 1511#endif /* PKCS11 */ 1512 1513 n_ids = 0; 1514 bzero(identity_files, sizeof(identity_files)); 1515 bzero(identity_keys, sizeof(identity_keys)); 1516 1517#ifdef ENABLE_PKCS11 1518 if (options.pkcs11_provider != NULL && 1519 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 1520 (pkcs11_init(!options.batch_mode) == 0) && 1521 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 1522 &keys)) > 0) { 1523 for (i = 0; i < nkeys; i++) { 1524 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 1525 key_free(keys[i]); 1526 continue; 1527 } 1528 identity_keys[n_ids] = keys[i]; 1529 identity_files[n_ids] = 1530 xstrdup(options.pkcs11_provider); /* XXX */ 1531 n_ids++; 1532 } 1533 xfree(keys); 1534 } 1535#endif /* ENABLE_PKCS11 */ 1536 if ((pw = getpwuid(original_real_uid)) == NULL) 1537 fatal("load_public_identity_files: getpwuid failed"); 1538 pwname = xstrdup(pw->pw_name); 1539 pwdir = xstrdup(pw->pw_dir); 1540 if (gethostname(thishost, sizeof(thishost)) == -1) 1541 fatal("load_public_identity_files: gethostname: %s", 1542 strerror(errno)); 1543 for (i = 0; i < options.num_identity_files; i++) { 1544 if (n_ids >= SSH_MAX_IDENTITY_FILES || 1545 strcasecmp(options.identity_files[i], "none") == 0) { 1546 xfree(options.identity_files[i]); 1547 continue; 1548 } 1549 cp = tilde_expand_filename(options.identity_files[i], 1550 original_real_uid); 1551 filename = percent_expand(cp, "d", pwdir, 1552 "u", pwname, "l", thishost, "h", host, 1553 "r", options.user, (char *)NULL); 1554 xfree(cp); 1555 public = key_load_public(filename, NULL); 1556 debug("identity file %s type %d", filename, 1557 public ? public->type : -1); 1558 xfree(options.identity_files[i]); 1559 identity_files[n_ids] = filename; 1560 identity_keys[n_ids] = public; 1561 1562 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 1563 continue; 1564 1565 /* Try to add the certificate variant too */ 1566 xasprintf(&cp, "%s-cert", filename); 1567 public = key_load_public(cp, NULL); 1568 debug("identity file %s type %d", cp, 1569 public ? public->type : -1); 1570 if (public == NULL) { 1571 xfree(cp); 1572 continue; 1573 } 1574 if (!key_is_cert(public)) { 1575 debug("%s: key %s type %s is not a certificate", 1576 __func__, cp, key_type(public)); 1577 key_free(public); 1578 xfree(cp); 1579 continue; 1580 } 1581 identity_keys[n_ids] = public; 1582 /* point to the original path, most likely the private key */ 1583 identity_files[n_ids] = xstrdup(filename); 1584 n_ids++; 1585 } 1586 options.num_identity_files = n_ids; 1587 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 1588 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 1589 1590 bzero(pwname, strlen(pwname)); 1591 xfree(pwname); 1592 bzero(pwdir, strlen(pwdir)); 1593 xfree(pwdir); 1594} 1595 1596static void 1597main_sigchld_handler(int sig) 1598{ 1599 int save_errno = errno; 1600 pid_t pid; 1601 int status; 1602 1603 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 1604 (pid < 0 && errno == EINTR)) 1605 ; 1606 1607 signal(sig, main_sigchld_handler); 1608 errno = save_errno; 1609} 1610 1611