1 /* $OpenBSD: ssh.c,v 1.356 2011/01/06 22:23:53 djm Exp $ */ 2 /* 3 * Author: Tatu Ylonen <ylo@cs.hut.fi> 4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland 5 * All rights reserved 6 * Ssh client program. This program can be used to log into a remote machine. 7 * The software supports strong authentication, encryption, and forwarding 8 * of X11, TCP/IP, and authentication connections. 9 * 10 * As far as I am concerned, the code I have written for this software 11 * can be used freely for any purpose. Any derived versions of this 12 * software must be clearly marked as such, and if the derived work is 13 * incompatible with the protocol description in the RFC file, it must be 14 * called by a name other than "ssh" or "Secure Shell". 15 * 16 * Copyright (c) 1999 Niels Provos. All rights reserved. 17 * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl. All rights reserved. 18 * 19 * Modified to work with SSL by Niels Provos <provos@citi.umich.edu> 20 * in Canada (German citizen). 21 * 22 * Redistribution and use in source and binary forms, with or without 23 * modification, are permitted provided that the following conditions 24 * are met: 25 * 1. Redistributions of source code must retain the above copyright 26 * notice, this list of conditions and the following disclaimer. 27 * 2. Redistributions in binary form must reproduce the above copyright 28 * notice, this list of conditions and the following disclaimer in the 29 * documentation and/or other materials provided with the distribution. 30 * 31 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR 32 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES 33 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 34 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, 35 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT 36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 37 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 38 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 39 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 40 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 41 */ 42 43 #include "includes.h" 44 __RCSID("$FreeBSD$"); 45 46 #include <sys/types.h> 47 #ifdef HAVE_SYS_STAT_H 48 # include <sys/stat.h> 49 #endif 50 #include <sys/resource.h> 51 #include <sys/ioctl.h> 52 #include <sys/param.h> 53 #include <sys/socket.h> 54 #include <sys/wait.h> 55 56 #include <ctype.h> 57 #include <errno.h> 58 #include <fcntl.h> 59 #include <netdb.h> 60 #ifdef HAVE_PATHS_H 61 #include <paths.h> 62 #endif 63 #include <pwd.h> 64 #include <signal.h> 65 #include <stdarg.h> 66 #include <stddef.h> 67 #include <stdio.h> 68 #include <stdlib.h> 69 #include <string.h> 70 #include <unistd.h> 71 72 #include <netinet/in.h> 73 #include <arpa/inet.h> 74 75 #include <openssl/evp.h> 76 #include <openssl/err.h> 77 #include "openbsd-compat/openssl-compat.h" 78 #include "openbsd-compat/sys-queue.h" 79 80 #include "xmalloc.h" 81 #include "ssh.h" 82 #include "ssh1.h" 83 #include "ssh2.h" 84 #include "canohost.h" 85 #include "compat.h" 86 #include "cipher.h" 87 #include "packet.h" 88 #include "buffer.h" 89 #include "channels.h" 90 #include "key.h" 91 #include "authfd.h" 92 #include "authfile.h" 93 #include "pathnames.h" 94 #include "dispatch.h" 95 #include "clientloop.h" 96 #include "log.h" 97 #include "readconf.h" 98 #include "sshconnect.h" 99 #include "misc.h" 100 #include "kex.h" 101 #include "mac.h" 102 #include "sshpty.h" 103 #include "match.h" 104 #include "msg.h" 105 #include "uidswap.h" 106 #include "roaming.h" 107 #include "version.h" 108 109 #ifdef ENABLE_PKCS11 110 #include "ssh-pkcs11.h" 111 #endif 112 113 extern char *__progname; 114 115 /* Flag indicating whether debug mode is on. May be set on the command line. */ 116 int debug_flag = 0; 117 118 /* Flag indicating whether a tty should be allocated */ 119 int tty_flag = 0; 120 int no_tty_flag = 0; 121 int force_tty_flag = 0; 122 123 /* don't exec a shell */ 124 int no_shell_flag = 0; 125 126 /* 127 * Flag indicating that nothing should be read from stdin. This can be set 128 * on the command line. 129 */ 130 int stdin_null_flag = 0; 131 132 /* 133 * Flag indicating that the current process should be backgrounded and 134 * a new slave launched in the foreground for ControlPersist. 135 */ 136 int need_controlpersist_detach = 0; 137 138 /* Copies of flags for ControlPersist foreground slave */ 139 int ostdin_null_flag, ono_shell_flag, ono_tty_flag, otty_flag; 140 141 /* 142 * Flag indicating that ssh should fork after authentication. This is useful 143 * so that the passphrase can be entered manually, and then ssh goes to the 144 * background. 145 */ 146 int fork_after_authentication_flag = 0; 147 148 /* forward stdio to remote host and port */ 149 char *stdio_forward_host = NULL; 150 int stdio_forward_port = 0; 151 152 /* 153 * General data structure for command line options and options configurable 154 * in configuration files. See readconf.h. 155 */ 156 Options options; 157 158 /* optional user configfile */ 159 char *config = NULL; 160 161 /* 162 * Name of the host we are connecting to. This is the name given on the 163 * command line, or the HostName specified for the user-supplied name in a 164 * configuration file. 165 */ 166 char *host; 167 168 /* socket address the host resolves to */ 169 struct sockaddr_storage hostaddr; 170 171 /* Private host keys. */ 172 Sensitive sensitive_data; 173 174 /* Original real UID. */ 175 uid_t original_real_uid; 176 uid_t original_effective_uid; 177 178 /* command to be executed */ 179 Buffer command; 180 181 /* Should we execute a command or invoke a subsystem? */ 182 int subsystem_flag = 0; 183 184 /* # of replies received for global requests */ 185 static int remote_forward_confirms_received = 0; 186 187 /* mux.c */ 188 extern int muxserver_sock; 189 extern u_int muxclient_command; 190 191 /* Prints a help message to the user. This function never returns. */ 192 193 static void 194 usage(void) 195 { 196 fprintf(stderr, 197 "usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n" 198 " [-D [bind_address:]port] [-e escape_char] [-F configfile]\n" 199 " [-I pkcs11] [-i identity_file]\n" 200 " [-L [bind_address:]port:host:hostport]\n" 201 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" 202 " [-R [bind_address:]port:host:hostport] [-S ctl_path]\n" 203 " [-W host:port] [-w local_tun[:remote_tun]]\n" 204 " [user@]hostname [command]\n" 205 ); 206 exit(255); 207 } 208 209 static int ssh_session(void); 210 static int ssh_session2(void); 211 static void load_public_identity_files(void); 212 static void main_sigchld_handler(int); 213 214 /* from muxclient.c */ 215 void muxclient(const char *); 216 void muxserver_listen(void); 217 218 /* 219 * Main program for the ssh client. 220 */ 221 int 222 main(int ac, char **av) 223 { 224 int i, r, opt, exit_status, use_syslog; 225 char *p, *cp, *line, *argv0, buf[MAXPATHLEN], *host_arg; 226 struct stat st; 227 struct passwd *pw; 228 int dummy, timeout_ms; 229 extern int optind, optreset; 230 extern char *optarg; 231 struct servent *sp; 232 Forward fwd; 233 234 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 235 sanitise_stdfd(); 236 237 __progname = ssh_get_progname(av[0]); 238 init_rng(); 239 240 /* 241 * Discard other fds that are hanging around. These can cause problem 242 * with backgrounded ssh processes started by ControlPersist. 243 */ 244 closefrom(STDERR_FILENO + 1); 245 246 /* 247 * Save the original real uid. It will be needed later (uid-swapping 248 * may clobber the real uid). 249 */ 250 original_real_uid = getuid(); 251 original_effective_uid = geteuid(); 252 253 /* 254 * Use uid-swapping to give up root privileges for the duration of 255 * option processing. We will re-instantiate the rights when we are 256 * ready to create the privileged port, and will permanently drop 257 * them when the port has been created (actually, when the connection 258 * has been made, as we may need to create the port several times). 259 */ 260 PRIV_END; 261 262 #ifdef HAVE_SETRLIMIT 263 /* If we are installed setuid root be careful to not drop core. */ 264 if (original_real_uid != original_effective_uid) { 265 struct rlimit rlim; 266 rlim.rlim_cur = rlim.rlim_max = 0; 267 if (setrlimit(RLIMIT_CORE, &rlim) < 0) 268 fatal("setrlimit failed: %.100s", strerror(errno)); 269 } 270 #endif 271 /* Get user data. */ 272 pw = getpwuid(original_real_uid); 273 if (!pw) { 274 logit("You don't exist, go away!"); 275 exit(255); 276 } 277 /* Take a copy of the returned structure. */ 278 pw = pwcopy(pw); 279 280 /* 281 * Set our umask to something reasonable, as some files are created 282 * with the default umask. This will make them world-readable but 283 * writable only by the owner, which is ok for all files for which we 284 * don't set the modes explicitly. 285 */ 286 umask(022); 287 288 /* 289 * Initialize option structure to indicate that no values have been 290 * set. 291 */ 292 initialize_options(&options); 293 294 /* Parse command-line arguments. */ 295 host = NULL; 296 use_syslog = 0; 297 argv0 = av[0]; 298 299 again: 300 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 301 "ACD:F:I:KL:MNO:PR:S:TVw:W:XYy")) != -1) { 302 switch (opt) { 303 case '1': 304 options.protocol = SSH_PROTO_1; 305 break; 306 case '2': 307 options.protocol = SSH_PROTO_2; 308 break; 309 case '4': 310 options.address_family = AF_INET; 311 break; 312 case '6': 313 options.address_family = AF_INET6; 314 break; 315 case 'n': 316 stdin_null_flag = 1; 317 break; 318 case 'f': 319 fork_after_authentication_flag = 1; 320 stdin_null_flag = 1; 321 break; 322 case 'x': 323 options.forward_x11 = 0; 324 break; 325 case 'X': 326 options.forward_x11 = 1; 327 break; 328 case 'y': 329 use_syslog = 1; 330 break; 331 case 'Y': 332 options.forward_x11 = 1; 333 options.forward_x11_trusted = 1; 334 break; 335 case 'g': 336 options.gateway_ports = 1; 337 break; 338 case 'O': 339 if (stdio_forward_host != NULL) 340 fatal("Cannot specify multiplexing " 341 "command with -W"); 342 else if (muxclient_command != 0) 343 fatal("Multiplexing command already specified"); 344 if (strcmp(optarg, "check") == 0) 345 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 346 else if (strcmp(optarg, "forward") == 0) 347 muxclient_command = SSHMUX_COMMAND_FORWARD; 348 else if (strcmp(optarg, "exit") == 0) 349 muxclient_command = SSHMUX_COMMAND_TERMINATE; 350 else 351 fatal("Invalid multiplex command."); 352 break; 353 case 'P': /* deprecated */ 354 options.use_privileged_port = 0; 355 break; 356 case 'a': 357 options.forward_agent = 0; 358 break; 359 case 'A': 360 options.forward_agent = 1; 361 break; 362 case 'k': 363 options.gss_deleg_creds = 0; 364 break; 365 case 'K': 366 options.gss_authentication = 1; 367 options.gss_deleg_creds = 1; 368 break; 369 case 'i': 370 if (stat(optarg, &st) < 0) { 371 fprintf(stderr, "Warning: Identity file %s " 372 "not accessible: %s.\n", optarg, 373 strerror(errno)); 374 break; 375 } 376 if (options.num_identity_files >= 377 SSH_MAX_IDENTITY_FILES) 378 fatal("Too many identity files specified " 379 "(max %d)", SSH_MAX_IDENTITY_FILES); 380 options.identity_files[options.num_identity_files++] = 381 xstrdup(optarg); 382 break; 383 case 'I': 384 #ifdef ENABLE_PKCS11 385 options.pkcs11_provider = xstrdup(optarg); 386 #else 387 fprintf(stderr, "no support for PKCS#11.\n"); 388 #endif 389 break; 390 case 't': 391 if (tty_flag) 392 force_tty_flag = 1; 393 tty_flag = 1; 394 break; 395 case 'v': 396 if (debug_flag == 0) { 397 debug_flag = 1; 398 options.log_level = SYSLOG_LEVEL_DEBUG1; 399 } else { 400 if (options.log_level < SYSLOG_LEVEL_DEBUG3) 401 options.log_level++; 402 break; 403 } 404 /* FALLTHROUGH */ 405 case 'V': 406 fprintf(stderr, "%s, %s\n", 407 SSH_RELEASE, SSLeay_version(SSLEAY_VERSION)); 408 if (opt == 'V') 409 exit(0); 410 break; 411 case 'w': 412 if (options.tun_open == -1) 413 options.tun_open = SSH_TUNMODE_DEFAULT; 414 options.tun_local = a2tun(optarg, &options.tun_remote); 415 if (options.tun_local == SSH_TUNID_ERR) { 416 fprintf(stderr, 417 "Bad tun device '%s'\n", optarg); 418 exit(255); 419 } 420 break; 421 case 'W': 422 if (stdio_forward_host != NULL) 423 fatal("stdio forward already specified"); 424 if (muxclient_command != 0) 425 fatal("Cannot specify stdio forward with -O"); 426 if (parse_forward(&fwd, optarg, 1, 0)) { 427 stdio_forward_host = fwd.listen_host; 428 stdio_forward_port = fwd.listen_port; 429 xfree(fwd.connect_host); 430 } else { 431 fprintf(stderr, 432 "Bad stdio forwarding specification '%s'\n", 433 optarg); 434 exit(255); 435 } 436 no_tty_flag = 1; 437 no_shell_flag = 1; 438 options.clear_forwardings = 1; 439 options.exit_on_forward_failure = 1; 440 break; 441 case 'q': 442 options.log_level = SYSLOG_LEVEL_QUIET; 443 break; 444 case 'e': 445 if (optarg[0] == '^' && optarg[2] == 0 && 446 (u_char) optarg[1] >= 64 && 447 (u_char) optarg[1] < 128) 448 options.escape_char = (u_char) optarg[1] & 31; 449 else if (strlen(optarg) == 1) 450 options.escape_char = (u_char) optarg[0]; 451 else if (strcmp(optarg, "none") == 0) 452 options.escape_char = SSH_ESCAPECHAR_NONE; 453 else { 454 fprintf(stderr, "Bad escape character '%s'.\n", 455 optarg); 456 exit(255); 457 } 458 break; 459 case 'c': 460 if (ciphers_valid(optarg)) { 461 /* SSH2 only */ 462 options.ciphers = xstrdup(optarg); 463 options.cipher = SSH_CIPHER_INVALID; 464 } else { 465 /* SSH1 only */ 466 options.cipher = cipher_number(optarg); 467 if (options.cipher == -1) { 468 fprintf(stderr, 469 "Unknown cipher type '%s'\n", 470 optarg); 471 exit(255); 472 } 473 if (options.cipher == SSH_CIPHER_3DES) 474 options.ciphers = "3des-cbc"; 475 else if (options.cipher == SSH_CIPHER_BLOWFISH) 476 options.ciphers = "blowfish-cbc"; 477 else 478 options.ciphers = (char *)-1; 479 } 480 break; 481 case 'm': 482 if (mac_valid(optarg)) 483 options.macs = xstrdup(optarg); 484 else { 485 fprintf(stderr, "Unknown mac type '%s'\n", 486 optarg); 487 exit(255); 488 } 489 break; 490 case 'M': 491 if (options.control_master == SSHCTL_MASTER_YES) 492 options.control_master = SSHCTL_MASTER_ASK; 493 else 494 options.control_master = SSHCTL_MASTER_YES; 495 break; 496 case 'p': 497 options.port = a2port(optarg); 498 if (options.port <= 0) { 499 fprintf(stderr, "Bad port '%s'\n", optarg); 500 exit(255); 501 } 502 break; 503 case 'l': 504 options.user = optarg; 505 break; 506 507 case 'L': 508 if (parse_forward(&fwd, optarg, 0, 0)) 509 add_local_forward(&options, &fwd); 510 else { 511 fprintf(stderr, 512 "Bad local forwarding specification '%s'\n", 513 optarg); 514 exit(255); 515 } 516 break; 517 518 case 'R': 519 if (parse_forward(&fwd, optarg, 0, 1)) { 520 add_remote_forward(&options, &fwd); 521 } else { 522 fprintf(stderr, 523 "Bad remote forwarding specification " 524 "'%s'\n", optarg); 525 exit(255); 526 } 527 break; 528 529 case 'D': 530 if (parse_forward(&fwd, optarg, 1, 0)) { 531 add_local_forward(&options, &fwd); 532 } else { 533 fprintf(stderr, 534 "Bad dynamic forwarding specification " 535 "'%s'\n", optarg); 536 exit(255); 537 } 538 break; 539 540 case 'C': 541 options.compression = 1; 542 break; 543 case 'N': 544 no_shell_flag = 1; 545 no_tty_flag = 1; 546 break; 547 case 'T': 548 no_tty_flag = 1; 549 break; 550 case 'o': 551 dummy = 1; 552 line = xstrdup(optarg); 553 if (process_config_line(&options, host ? host : "", 554 line, "command-line", 0, &dummy) != 0) 555 exit(255); 556 xfree(line); 557 break; 558 case 's': 559 subsystem_flag = 1; 560 break; 561 case 'S': 562 if (options.control_path != NULL) 563 free(options.control_path); 564 options.control_path = xstrdup(optarg); 565 break; 566 case 'b': 567 options.bind_address = optarg; 568 break; 569 case 'F': 570 config = optarg; 571 break; 572 default: 573 usage(); 574 } 575 } 576 577 ac -= optind; 578 av += optind; 579 580 if (ac > 0 && !host) { 581 if (strrchr(*av, '@')) { 582 p = xstrdup(*av); 583 cp = strrchr(p, '@'); 584 if (cp == NULL || cp == p) 585 usage(); 586 options.user = p; 587 *cp = '\0'; 588 host = ++cp; 589 } else 590 host = *av; 591 if (ac > 1) { 592 optind = optreset = 1; 593 goto again; 594 } 595 ac--, av++; 596 } 597 598 /* Check that we got a host name. */ 599 if (!host) 600 usage(); 601 602 OpenSSL_add_all_algorithms(); 603 ERR_load_crypto_strings(); 604 605 /* Initialize the command to execute on remote host. */ 606 buffer_init(&command); 607 608 /* 609 * Save the command to execute on the remote host in a buffer. There 610 * is no limit on the length of the command, except by the maximum 611 * packet size. Also sets the tty flag if there is no command. 612 */ 613 if (!ac) { 614 /* No command specified - execute shell on a tty. */ 615 tty_flag = 1; 616 if (subsystem_flag) { 617 fprintf(stderr, 618 "You must specify a subsystem to invoke.\n"); 619 usage(); 620 } 621 } else { 622 /* A command has been specified. Store it into the buffer. */ 623 for (i = 0; i < ac; i++) { 624 if (i) 625 buffer_append(&command, " ", 1); 626 buffer_append(&command, av[i], strlen(av[i])); 627 } 628 } 629 630 /* Cannot fork to background if no command. */ 631 if (fork_after_authentication_flag && buffer_len(&command) == 0 && 632 !no_shell_flag) 633 fatal("Cannot fork into background without a command " 634 "to execute."); 635 636 /* Allocate a tty by default if no command specified. */ 637 if (buffer_len(&command) == 0) 638 tty_flag = 1; 639 640 /* Force no tty */ 641 if (no_tty_flag || muxclient_command != 0) 642 tty_flag = 0; 643 /* Do not allocate a tty if stdin is not a tty. */ 644 if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) { 645 if (tty_flag) 646 logit("Pseudo-terminal will not be allocated because " 647 "stdin is not a terminal."); 648 tty_flag = 0; 649 } 650 651 /* 652 * Initialize "log" output. Since we are the client all output 653 * actually goes to stderr. 654 */ 655 log_init(argv0, 656 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, 657 SYSLOG_FACILITY_USER, !use_syslog); 658 659 /* 660 * Read per-user configuration file. Ignore the system wide config 661 * file if the user specifies a config file on the command line. 662 */ 663 if (config != NULL) { 664 if (!read_config_file(config, host, &options, 0)) 665 fatal("Can't open user config file %.100s: " 666 "%.100s", config, strerror(errno)); 667 } else { 668 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 669 _PATH_SSH_USER_CONFFILE); 670 if (r > 0 && (size_t)r < sizeof(buf)) 671 (void)read_config_file(buf, host, &options, 1); 672 673 /* Read systemwide configuration file after use config. */ 674 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, 675 &options, 0); 676 } 677 678 /* Fill configuration defaults. */ 679 fill_default_options(&options); 680 681 channel_set_af(options.address_family); 682 683 /* reinit */ 684 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog); 685 686 seed_rng(); 687 688 if (options.user == NULL) 689 options.user = xstrdup(pw->pw_name); 690 691 /* Get default port if port has not been set. */ 692 if (options.port == 0) { 693 sp = getservbyname(SSH_SERVICE_NAME, "tcp"); 694 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT; 695 } 696 697 /* preserve host name given on command line for %n expansion */ 698 host_arg = host; 699 if (options.hostname != NULL) { 700 host = percent_expand(options.hostname, 701 "h", host, (char *)NULL); 702 } 703 704 if (options.local_command != NULL) { 705 char thishost[NI_MAXHOST]; 706 707 if (gethostname(thishost, sizeof(thishost)) == -1) 708 fatal("gethostname: %s", strerror(errno)); 709 snprintf(buf, sizeof(buf), "%d", options.port); 710 debug3("expanding LocalCommand: %s", options.local_command); 711 cp = options.local_command; 712 options.local_command = percent_expand(cp, "d", pw->pw_dir, 713 "h", host, "l", thishost, "n", host_arg, "r", options.user, 714 "p", buf, "u", pw->pw_name, (char *)NULL); 715 debug3("expanded LocalCommand: %s", options.local_command); 716 xfree(cp); 717 } 718 719 /* Find canonic host name. */ 720 if (strchr(host, '.') == 0) { 721 struct addrinfo hints; 722 struct addrinfo *ai = NULL; 723 int errgai; 724 memset(&hints, 0, sizeof(hints)); 725 hints.ai_family = options.address_family; 726 hints.ai_flags = AI_CANONNAME; 727 hints.ai_socktype = SOCK_STREAM; 728 errgai = getaddrinfo(host, NULL, &hints, &ai); 729 if (errgai == 0) { 730 if (ai->ai_canonname != NULL) 731 host = xstrdup(ai->ai_canonname); 732 freeaddrinfo(ai); 733 } 734 } 735 736 /* force lowercase for hostkey matching */ 737 if (options.host_key_alias != NULL) { 738 for (p = options.host_key_alias; *p; p++) 739 if (isupper(*p)) 740 *p = (char)tolower(*p); 741 } 742 743 if (options.proxy_command != NULL && 744 strcmp(options.proxy_command, "none") == 0) { 745 xfree(options.proxy_command); 746 options.proxy_command = NULL; 747 } 748 if (options.control_path != NULL && 749 strcmp(options.control_path, "none") == 0) { 750 xfree(options.control_path); 751 options.control_path = NULL; 752 } 753 754 if (options.control_path != NULL) { 755 char thishost[NI_MAXHOST]; 756 757 if (gethostname(thishost, sizeof(thishost)) == -1) 758 fatal("gethostname: %s", strerror(errno)); 759 snprintf(buf, sizeof(buf), "%d", options.port); 760 cp = tilde_expand_filename(options.control_path, 761 original_real_uid); 762 xfree(options.control_path); 763 options.control_path = percent_expand(cp, "p", buf, "h", host, 764 "r", options.user, "l", thishost, (char *)NULL); 765 xfree(cp); 766 } 767 if (muxclient_command != 0 && options.control_path == NULL) 768 fatal("No ControlPath specified for \"-O\" command"); 769 if (options.control_path != NULL) 770 muxclient(options.control_path); 771 772 timeout_ms = options.connection_timeout * 1000; 773 774 /* Open a connection to the remote host. */ 775 if (ssh_connect(host, &hostaddr, options.port, 776 options.address_family, options.connection_attempts, &timeout_ms, 777 options.tcp_keep_alive, 778 #ifdef HAVE_CYGWIN 779 options.use_privileged_port, 780 #else 781 original_effective_uid == 0 && options.use_privileged_port, 782 #endif 783 options.proxy_command) != 0) 784 exit(255); 785 786 if (timeout_ms > 0) 787 debug3("timeout: %d ms remain after connect", timeout_ms); 788 789 /* 790 * If we successfully made the connection, load the host private key 791 * in case we will need it later for combined rsa-rhosts 792 * authentication. This must be done before releasing extra 793 * privileges, because the file is only readable by root. 794 * If we cannot access the private keys, load the public keys 795 * instead and try to execute the ssh-keysign helper instead. 796 */ 797 sensitive_data.nkeys = 0; 798 sensitive_data.keys = NULL; 799 sensitive_data.external_keysign = 0; 800 if (options.rhosts_rsa_authentication || 801 options.hostbased_authentication) { 802 sensitive_data.nkeys = 7; 803 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 804 sizeof(Key)); 805 for (i = 0; i < sensitive_data.nkeys; i++) 806 sensitive_data.keys[i] = NULL; 807 808 PRIV_START; 809 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, 810 _PATH_HOST_KEY_FILE, "", NULL, NULL); 811 sensitive_data.keys[1] = key_load_private_cert(KEY_DSA, 812 _PATH_HOST_DSA_KEY_FILE, "", NULL); 813 #ifdef OPENSSL_HAS_ECC 814 sensitive_data.keys[2] = key_load_private_cert(KEY_ECDSA, 815 _PATH_HOST_ECDSA_KEY_FILE, "", NULL); 816 #endif 817 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA, 818 _PATH_HOST_RSA_KEY_FILE, "", NULL); 819 sensitive_data.keys[4] = key_load_private_type(KEY_DSA, 820 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); 821 #ifdef OPENSSL_HAS_ECC 822 sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA, 823 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL); 824 #endif 825 sensitive_data.keys[6] = key_load_private_type(KEY_RSA, 826 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); 827 PRIV_END; 828 829 if (options.hostbased_authentication == 1 && 830 sensitive_data.keys[0] == NULL && 831 sensitive_data.keys[4] == NULL && 832 sensitive_data.keys[5] == NULL && 833 sensitive_data.keys[6] == NULL) { 834 sensitive_data.keys[1] = key_load_cert( 835 _PATH_HOST_DSA_KEY_FILE); 836 #ifdef OPENSSL_HAS_ECC 837 sensitive_data.keys[2] = key_load_cert( 838 _PATH_HOST_ECDSA_KEY_FILE); 839 #endif 840 sensitive_data.keys[3] = key_load_cert( 841 _PATH_HOST_RSA_KEY_FILE); 842 sensitive_data.keys[4] = key_load_public( 843 _PATH_HOST_DSA_KEY_FILE, NULL); 844 #ifdef OPENSSL_HAS_ECC 845 sensitive_data.keys[5] = key_load_public( 846 _PATH_HOST_ECDSA_KEY_FILE, NULL); 847 #endif 848 sensitive_data.keys[6] = key_load_public( 849 _PATH_HOST_RSA_KEY_FILE, NULL); 850 sensitive_data.external_keysign = 1; 851 } 852 } 853 /* 854 * Get rid of any extra privileges that we may have. We will no 855 * longer need them. Also, extra privileges could make it very hard 856 * to read identity files and other non-world-readable files from the 857 * user's home directory if it happens to be on a NFS volume where 858 * root is mapped to nobody. 859 */ 860 if (original_effective_uid == 0) { 861 PRIV_START; 862 permanently_set_uid(pw); 863 } 864 865 /* 866 * Now that we are back to our own permissions, create ~/.ssh 867 * directory if it doesn't already exist. 868 */ 869 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 870 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 871 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) { 872 #ifdef WITH_SELINUX 873 ssh_selinux_setfscreatecon(buf); 874 #endif 875 if (mkdir(buf, 0700) < 0) 876 error("Could not create directory '%.200s'.", buf); 877 #ifdef WITH_SELINUX 878 ssh_selinux_setfscreatecon(NULL); 879 #endif 880 } 881 /* load options.identity_files */ 882 load_public_identity_files(); 883 884 /* Expand ~ in known host file names. */ 885 /* XXX mem-leaks: */ 886 options.system_hostfile = 887 tilde_expand_filename(options.system_hostfile, original_real_uid); 888 options.user_hostfile = 889 tilde_expand_filename(options.user_hostfile, original_real_uid); 890 options.system_hostfile2 = 891 tilde_expand_filename(options.system_hostfile2, original_real_uid); 892 options.user_hostfile2 = 893 tilde_expand_filename(options.user_hostfile2, original_real_uid); 894 895 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 896 signal(SIGCHLD, main_sigchld_handler); 897 898 /* Log into the remote system. Never returns if the login fails. */ 899 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, 900 options.port, pw, timeout_ms); 901 902 if (packet_connection_is_on_socket()) { 903 verbose("Authenticated to %s ([%s]:%d).", host, 904 get_remote_ipaddr(), get_remote_port()); 905 } else { 906 verbose("Authenticated to %s (via proxy).", host); 907 } 908 909 /* We no longer need the private host keys. Clear them now. */ 910 if (sensitive_data.nkeys != 0) { 911 for (i = 0; i < sensitive_data.nkeys; i++) { 912 if (sensitive_data.keys[i] != NULL) { 913 /* Destroys contents safely */ 914 debug3("clear hostkey %d", i); 915 key_free(sensitive_data.keys[i]); 916 sensitive_data.keys[i] = NULL; 917 } 918 } 919 xfree(sensitive_data.keys); 920 } 921 for (i = 0; i < options.num_identity_files; i++) { 922 if (options.identity_files[i]) { 923 xfree(options.identity_files[i]); 924 options.identity_files[i] = NULL; 925 } 926 if (options.identity_keys[i]) { 927 key_free(options.identity_keys[i]); 928 options.identity_keys[i] = NULL; 929 } 930 } 931 932 exit_status = compat20 ? ssh_session2() : ssh_session(); 933 packet_close(); 934 935 if (options.control_path != NULL && muxserver_sock != -1) 936 unlink(options.control_path); 937 938 /* Kill ProxyCommand if it is running. */ 939 ssh_kill_proxy_command(); 940 941 return exit_status; 942 } 943 944 static void 945 control_persist_detach(void) 946 { 947 pid_t pid; 948 int devnull; 949 950 debug("%s: backgrounding master process", __func__); 951 952 /* 953 * master (current process) into the background, and make the 954 * foreground process a client of the backgrounded master. 955 */ 956 switch ((pid = fork())) { 957 case -1: 958 fatal("%s: fork: %s", __func__, strerror(errno)); 959 case 0: 960 /* Child: master process continues mainloop */ 961 break; 962 default: 963 /* Parent: set up mux slave to connect to backgrounded master */ 964 debug2("%s: background process is %ld", __func__, (long)pid); 965 stdin_null_flag = ostdin_null_flag; 966 no_shell_flag = ono_shell_flag; 967 no_tty_flag = ono_tty_flag; 968 tty_flag = otty_flag; 969 close(muxserver_sock); 970 muxserver_sock = -1; 971 options.control_master = SSHCTL_MASTER_NO; 972 muxclient(options.control_path); 973 /* muxclient() doesn't return on success. */ 974 fatal("Failed to connect to new control master"); 975 } 976 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 977 error("%s: open(\"/dev/null\"): %s", __func__, 978 strerror(errno)); 979 } else { 980 if (dup2(devnull, STDIN_FILENO) == -1 || 981 dup2(devnull, STDOUT_FILENO) == -1) 982 error("%s: dup2: %s", __func__, strerror(errno)); 983 if (devnull > STDERR_FILENO) 984 close(devnull); 985 } 986 } 987 988 /* Do fork() after authentication. Used by "ssh -f" */ 989 static void 990 fork_postauth(void) 991 { 992 if (need_controlpersist_detach) 993 control_persist_detach(); 994 debug("forking to background"); 995 fork_after_authentication_flag = 0; 996 if (daemon(1, 1) < 0) 997 fatal("daemon() failed: %.200s", strerror(errno)); 998 } 999 1000 /* Callback for remote forward global requests */ 1001 static void 1002 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) 1003 { 1004 Forward *rfwd = (Forward *)ctxt; 1005 1006 /* XXX verbose() on failure? */ 1007 debug("remote forward %s for: listen %d, connect %s:%d", 1008 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1009 rfwd->listen_port, rfwd->connect_host, rfwd->connect_port); 1010 if (type == SSH2_MSG_REQUEST_SUCCESS && rfwd->listen_port == 0) { 1011 rfwd->allocated_port = packet_get_int(); 1012 logit("Allocated port %u for remote forward to %s:%d", 1013 rfwd->allocated_port, 1014 rfwd->connect_host, rfwd->connect_port); 1015 } 1016 1017 if (type == SSH2_MSG_REQUEST_FAILURE) { 1018 if (options.exit_on_forward_failure) 1019 fatal("Error: remote port forwarding failed for " 1020 "listen port %d", rfwd->listen_port); 1021 else 1022 logit("Warning: remote port forwarding failed for " 1023 "listen port %d", rfwd->listen_port); 1024 } 1025 if (++remote_forward_confirms_received == options.num_remote_forwards) { 1026 debug("All remote forwarding requests processed"); 1027 if (fork_after_authentication_flag) 1028 fork_postauth(); 1029 } 1030 } 1031 1032 static void 1033 client_cleanup_stdio_fwd(int id, void *arg) 1034 { 1035 debug("stdio forwarding: done"); 1036 cleanup_exit(0); 1037 } 1038 1039 static int 1040 client_setup_stdio_fwd(const char *host_to_connect, u_short port_to_connect) 1041 { 1042 Channel *c; 1043 int in, out; 1044 1045 debug3("client_setup_stdio_fwd %s:%d", host_to_connect, 1046 port_to_connect); 1047 1048 in = dup(STDIN_FILENO); 1049 out = dup(STDOUT_FILENO); 1050 if (in < 0 || out < 0) 1051 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1052 1053 if ((c = channel_connect_stdio_fwd(host_to_connect, port_to_connect, 1054 in, out)) == NULL) 1055 return 0; 1056 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0); 1057 return 1; 1058 } 1059 1060 static void 1061 ssh_init_forwarding(void) 1062 { 1063 int success = 0; 1064 int i; 1065 1066 if (stdio_forward_host != NULL) { 1067 if (!compat20) { 1068 fatal("stdio forwarding require Protocol 2"); 1069 } 1070 if (!client_setup_stdio_fwd(stdio_forward_host, 1071 stdio_forward_port)) 1072 fatal("Failed to connect in stdio forward mode."); 1073 } 1074 1075 /* Initiate local TCP/IP port forwardings. */ 1076 for (i = 0; i < options.num_local_forwards; i++) { 1077 debug("Local connections to %.200s:%d forwarded to remote " 1078 "address %.200s:%d", 1079 (options.local_forwards[i].listen_host == NULL) ? 1080 (options.gateway_ports ? "*" : "LOCALHOST") : 1081 options.local_forwards[i].listen_host, 1082 options.local_forwards[i].listen_port, 1083 options.local_forwards[i].connect_host, 1084 options.local_forwards[i].connect_port); 1085 success += channel_setup_local_fwd_listener( 1086 options.local_forwards[i].listen_host, 1087 options.local_forwards[i].listen_port, 1088 options.local_forwards[i].connect_host, 1089 options.local_forwards[i].connect_port, 1090 options.gateway_ports); 1091 } 1092 if (i > 0 && success != i && options.exit_on_forward_failure) 1093 fatal("Could not request local forwarding."); 1094 if (i > 0 && success == 0) 1095 error("Could not request local forwarding."); 1096 1097 /* Initiate remote TCP/IP port forwardings. */ 1098 for (i = 0; i < options.num_remote_forwards; i++) { 1099 debug("Remote connections from %.200s:%d forwarded to " 1100 "local address %.200s:%d", 1101 (options.remote_forwards[i].listen_host == NULL) ? 1102 "LOCALHOST" : options.remote_forwards[i].listen_host, 1103 options.remote_forwards[i].listen_port, 1104 options.remote_forwards[i].connect_host, 1105 options.remote_forwards[i].connect_port); 1106 if (channel_request_remote_forwarding( 1107 options.remote_forwards[i].listen_host, 1108 options.remote_forwards[i].listen_port, 1109 options.remote_forwards[i].connect_host, 1110 options.remote_forwards[i].connect_port) < 0) { 1111 if (options.exit_on_forward_failure) 1112 fatal("Could not request remote forwarding."); 1113 else 1114 logit("Warning: Could not request remote " 1115 "forwarding."); 1116 } 1117 client_register_global_confirm(ssh_confirm_remote_forward, 1118 &options.remote_forwards[i]); 1119 } 1120 1121 /* Initiate tunnel forwarding. */ 1122 if (options.tun_open != SSH_TUNMODE_NO) { 1123 if (client_request_tun_fwd(options.tun_open, 1124 options.tun_local, options.tun_remote) == -1) { 1125 if (options.exit_on_forward_failure) 1126 fatal("Could not request tunnel forwarding."); 1127 else 1128 error("Could not request tunnel forwarding."); 1129 } 1130 } 1131 } 1132 1133 static void 1134 check_agent_present(void) 1135 { 1136 if (options.forward_agent) { 1137 /* Clear agent forwarding if we don't have an agent. */ 1138 if (!ssh_agent_present()) 1139 options.forward_agent = 0; 1140 } 1141 } 1142 1143 static int 1144 ssh_session(void) 1145 { 1146 int type; 1147 int interactive = 0; 1148 int have_tty = 0; 1149 struct winsize ws; 1150 char *cp; 1151 const char *display; 1152 1153 /* Enable compression if requested. */ 1154 if (options.compression) { 1155 debug("Requesting compression at level %d.", 1156 options.compression_level); 1157 1158 if (options.compression_level < 1 || 1159 options.compression_level > 9) 1160 fatal("Compression level must be from 1 (fast) to " 1161 "9 (slow, best)."); 1162 1163 /* Send the request. */ 1164 packet_start(SSH_CMSG_REQUEST_COMPRESSION); 1165 packet_put_int(options.compression_level); 1166 packet_send(); 1167 packet_write_wait(); 1168 type = packet_read(); 1169 if (type == SSH_SMSG_SUCCESS) 1170 packet_start_compression(options.compression_level); 1171 else if (type == SSH_SMSG_FAILURE) 1172 logit("Warning: Remote host refused compression."); 1173 else 1174 packet_disconnect("Protocol error waiting for " 1175 "compression response."); 1176 } 1177 /* Allocate a pseudo tty if appropriate. */ 1178 if (tty_flag) { 1179 debug("Requesting pty."); 1180 1181 /* Start the packet. */ 1182 packet_start(SSH_CMSG_REQUEST_PTY); 1183 1184 /* Store TERM in the packet. There is no limit on the 1185 length of the string. */ 1186 cp = getenv("TERM"); 1187 if (!cp) 1188 cp = ""; 1189 packet_put_cstring(cp); 1190 1191 /* Store window size in the packet. */ 1192 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 1193 memset(&ws, 0, sizeof(ws)); 1194 packet_put_int((u_int)ws.ws_row); 1195 packet_put_int((u_int)ws.ws_col); 1196 packet_put_int((u_int)ws.ws_xpixel); 1197 packet_put_int((u_int)ws.ws_ypixel); 1198 1199 /* Store tty modes in the packet. */ 1200 tty_make_modes(fileno(stdin), NULL); 1201 1202 /* Send the packet, and wait for it to leave. */ 1203 packet_send(); 1204 packet_write_wait(); 1205 1206 /* Read response from the server. */ 1207 type = packet_read(); 1208 if (type == SSH_SMSG_SUCCESS) { 1209 interactive = 1; 1210 have_tty = 1; 1211 } else if (type == SSH_SMSG_FAILURE) 1212 logit("Warning: Remote host failed or refused to " 1213 "allocate a pseudo tty."); 1214 else 1215 packet_disconnect("Protocol error waiting for pty " 1216 "request response."); 1217 } 1218 /* Request X11 forwarding if enabled and DISPLAY is set. */ 1219 display = getenv("DISPLAY"); 1220 if (options.forward_x11 && display != NULL) { 1221 char *proto, *data; 1222 /* Get reasonable local authentication information. */ 1223 client_x11_get_proto(display, options.xauth_location, 1224 options.forward_x11_trusted, 1225 options.forward_x11_timeout, 1226 &proto, &data); 1227 /* Request forwarding with authentication spoofing. */ 1228 debug("Requesting X11 forwarding with authentication " 1229 "spoofing."); 1230 x11_request_forwarding_with_spoofing(0, display, proto, data); 1231 1232 /* Read response from the server. */ 1233 type = packet_read(); 1234 if (type == SSH_SMSG_SUCCESS) { 1235 interactive = 1; 1236 } else if (type == SSH_SMSG_FAILURE) { 1237 logit("Warning: Remote host denied X11 forwarding."); 1238 } else { 1239 packet_disconnect("Protocol error waiting for X11 " 1240 "forwarding"); 1241 } 1242 } 1243 /* Tell the packet module whether this is an interactive session. */ 1244 packet_set_interactive(interactive, 1245 options.ip_qos_interactive, options.ip_qos_bulk); 1246 1247 /* Request authentication agent forwarding if appropriate. */ 1248 check_agent_present(); 1249 1250 if (options.forward_agent) { 1251 debug("Requesting authentication agent forwarding."); 1252 auth_request_forwarding(); 1253 1254 /* Read response from the server. */ 1255 type = packet_read(); 1256 packet_check_eom(); 1257 if (type != SSH_SMSG_SUCCESS) 1258 logit("Warning: Remote host denied authentication agent forwarding."); 1259 } 1260 1261 /* Initiate port forwardings. */ 1262 ssh_init_forwarding(); 1263 1264 /* Execute a local command */ 1265 if (options.local_command != NULL && 1266 options.permit_local_command) 1267 ssh_local_cmd(options.local_command); 1268 1269 /* 1270 * If requested and we are not interested in replies to remote 1271 * forwarding requests, then let ssh continue in the background. 1272 */ 1273 if (fork_after_authentication_flag) { 1274 if (options.exit_on_forward_failure && 1275 options.num_remote_forwards > 0) { 1276 debug("deferring postauth fork until remote forward " 1277 "confirmation received"); 1278 } else 1279 fork_postauth(); 1280 } 1281 1282 /* 1283 * If a command was specified on the command line, execute the 1284 * command now. Otherwise request the server to start a shell. 1285 */ 1286 if (buffer_len(&command) > 0) { 1287 int len = buffer_len(&command); 1288 if (len > 900) 1289 len = 900; 1290 debug("Sending command: %.*s", len, 1291 (u_char *)buffer_ptr(&command)); 1292 packet_start(SSH_CMSG_EXEC_CMD); 1293 packet_put_string(buffer_ptr(&command), buffer_len(&command)); 1294 packet_send(); 1295 packet_write_wait(); 1296 } else { 1297 debug("Requesting shell."); 1298 packet_start(SSH_CMSG_EXEC_SHELL); 1299 packet_send(); 1300 packet_write_wait(); 1301 } 1302 1303 /* Enter the interactive session. */ 1304 return client_loop(have_tty, tty_flag ? 1305 options.escape_char : SSH_ESCAPECHAR_NONE, 0); 1306 } 1307 1308 /* request pty/x11/agent/tcpfwd/shell for channel */ 1309 static void 1310 ssh_session2_setup(int id, int success, void *arg) 1311 { 1312 extern char **environ; 1313 const char *display; 1314 int interactive = tty_flag; 1315 1316 if (!success) 1317 return; /* No need for error message, channels code sens one */ 1318 1319 display = getenv("DISPLAY"); 1320 if (options.forward_x11 && display != NULL) { 1321 char *proto, *data; 1322 /* Get reasonable local authentication information. */ 1323 client_x11_get_proto(display, options.xauth_location, 1324 options.forward_x11_trusted, 1325 options.forward_x11_timeout, &proto, &data); 1326 /* Request forwarding with authentication spoofing. */ 1327 debug("Requesting X11 forwarding with authentication " 1328 "spoofing."); 1329 x11_request_forwarding_with_spoofing(id, display, proto, data); 1330 interactive = 1; 1331 /* XXX wait for reply */ 1332 } 1333 1334 check_agent_present(); 1335 if (options.forward_agent) { 1336 debug("Requesting authentication agent forwarding."); 1337 channel_request_start(id, "auth-agent-req@openssh.com", 0); 1338 packet_send(); 1339 } 1340 1341 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), 1342 NULL, fileno(stdin), &command, environ); 1343 } 1344 1345 /* open new channel for a session */ 1346 static int 1347 ssh_session2_open(void) 1348 { 1349 Channel *c; 1350 int window, packetmax, in, out, err; 1351 1352 if (stdin_null_flag) { 1353 in = open(_PATH_DEVNULL, O_RDONLY); 1354 } else { 1355 in = dup(STDIN_FILENO); 1356 } 1357 out = dup(STDOUT_FILENO); 1358 err = dup(STDERR_FILENO); 1359 1360 if (in < 0 || out < 0 || err < 0) 1361 fatal("dup() in/out/err failed"); 1362 1363 /* enable nonblocking unless tty */ 1364 if (!isatty(in)) 1365 set_nonblock(in); 1366 if (!isatty(out)) 1367 set_nonblock(out); 1368 if (!isatty(err)) 1369 set_nonblock(err); 1370 1371 window = CHAN_SES_WINDOW_DEFAULT; 1372 packetmax = CHAN_SES_PACKET_DEFAULT; 1373 if (tty_flag) { 1374 window >>= 1; 1375 packetmax >>= 1; 1376 } 1377 c = channel_new( 1378 "session", SSH_CHANNEL_OPENING, in, out, err, 1379 window, packetmax, CHAN_EXTENDED_WRITE, 1380 "client-session", /*nonblock*/0); 1381 1382 debug3("ssh_session2_open: channel_new: %d", c->self); 1383 1384 channel_send_open(c->self); 1385 if (!no_shell_flag) 1386 channel_register_open_confirm(c->self, 1387 ssh_session2_setup, NULL); 1388 1389 return c->self; 1390 } 1391 1392 static int 1393 ssh_session2(void) 1394 { 1395 int id = -1; 1396 1397 /* XXX should be pre-session */ 1398 ssh_init_forwarding(); 1399 1400 /* Start listening for multiplex clients */ 1401 muxserver_listen(); 1402 1403 /* 1404 * If we are in control persist mode, then prepare to background 1405 * ourselves and have a foreground client attach as a control 1406 * slave. NB. we must save copies of the flags that we override for 1407 * the backgrounding, since we defer attachment of the slave until 1408 * after the connection is fully established (in particular, 1409 * async rfwd replies have been received for ExitOnForwardFailure). 1410 */ 1411 if (options.control_persist && muxserver_sock != -1) { 1412 ostdin_null_flag = stdin_null_flag; 1413 ono_shell_flag = no_shell_flag; 1414 ono_tty_flag = no_tty_flag; 1415 otty_flag = tty_flag; 1416 stdin_null_flag = 1; 1417 no_shell_flag = 1; 1418 no_tty_flag = 1; 1419 tty_flag = 0; 1420 if (!fork_after_authentication_flag) 1421 need_controlpersist_detach = 1; 1422 fork_after_authentication_flag = 1; 1423 } 1424 1425 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) 1426 id = ssh_session2_open(); 1427 1428 /* If we don't expect to open a new session, then disallow it */ 1429 if (options.control_master == SSHCTL_MASTER_NO && 1430 (datafellows & SSH_NEW_OPENSSH)) { 1431 debug("Requesting no-more-sessions@openssh.com"); 1432 packet_start(SSH2_MSG_GLOBAL_REQUEST); 1433 packet_put_cstring("no-more-sessions@openssh.com"); 1434 packet_put_char(0); 1435 packet_send(); 1436 } 1437 1438 /* Execute a local command */ 1439 if (options.local_command != NULL && 1440 options.permit_local_command) 1441 ssh_local_cmd(options.local_command); 1442 1443 /* 1444 * If requested and we are not interested in replies to remote 1445 * forwarding requests, then let ssh continue in the background. 1446 */ 1447 if (fork_after_authentication_flag) { 1448 if (options.exit_on_forward_failure && 1449 options.num_remote_forwards > 0) { 1450 debug("deferring postauth fork until remote forward " 1451 "confirmation received"); 1452 } else 1453 fork_postauth(); 1454 } 1455 1456 if (options.use_roaming) 1457 request_roaming(); 1458 1459 return client_loop(tty_flag, tty_flag ? 1460 options.escape_char : SSH_ESCAPECHAR_NONE, id); 1461 } 1462 1463 static void 1464 load_public_identity_files(void) 1465 { 1466 char *filename, *cp, thishost[NI_MAXHOST]; 1467 char *pwdir = NULL, *pwname = NULL; 1468 int i = 0; 1469 Key *public; 1470 struct passwd *pw; 1471 u_int n_ids; 1472 char *identity_files[SSH_MAX_IDENTITY_FILES]; 1473 Key *identity_keys[SSH_MAX_IDENTITY_FILES]; 1474 #ifdef ENABLE_PKCS11 1475 Key **keys; 1476 int nkeys; 1477 #endif /* PKCS11 */ 1478 1479 n_ids = 0; 1480 bzero(identity_files, sizeof(identity_files)); 1481 bzero(identity_keys, sizeof(identity_keys)); 1482 1483 #ifdef ENABLE_PKCS11 1484 if (options.pkcs11_provider != NULL && 1485 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 1486 (pkcs11_init(!options.batch_mode) == 0) && 1487 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 1488 &keys)) > 0) { 1489 for (i = 0; i < nkeys; i++) { 1490 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 1491 key_free(keys[i]); 1492 continue; 1493 } 1494 identity_keys[n_ids] = keys[i]; 1495 identity_files[n_ids] = 1496 xstrdup(options.pkcs11_provider); /* XXX */ 1497 n_ids++; 1498 } 1499 xfree(keys); 1500 } 1501 #endif /* ENABLE_PKCS11 */ 1502 if ((pw = getpwuid(original_real_uid)) == NULL) 1503 fatal("load_public_identity_files: getpwuid failed"); 1504 pwname = xstrdup(pw->pw_name); 1505 pwdir = xstrdup(pw->pw_dir); 1506 if (gethostname(thishost, sizeof(thishost)) == -1) 1507 fatal("load_public_identity_files: gethostname: %s", 1508 strerror(errno)); 1509 for (i = 0; i < options.num_identity_files; i++) { 1510 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 1511 xfree(options.identity_files[i]); 1512 continue; 1513 } 1514 cp = tilde_expand_filename(options.identity_files[i], 1515 original_real_uid); 1516 filename = percent_expand(cp, "d", pwdir, 1517 "u", pwname, "l", thishost, "h", host, 1518 "r", options.user, (char *)NULL); 1519 xfree(cp); 1520 public = key_load_public(filename, NULL); 1521 debug("identity file %s type %d", filename, 1522 public ? public->type : -1); 1523 xfree(options.identity_files[i]); 1524 identity_files[n_ids] = filename; 1525 identity_keys[n_ids] = public; 1526 1527 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 1528 continue; 1529 1530 /* Try to add the certificate variant too */ 1531 xasprintf(&cp, "%s-cert", filename); 1532 public = key_load_public(cp, NULL); 1533 debug("identity file %s type %d", cp, 1534 public ? public->type : -1); 1535 if (public == NULL) { 1536 xfree(cp); 1537 continue; 1538 } 1539 if (!key_is_cert(public)) { 1540 debug("%s: key %s type %s is not a certificate", 1541 __func__, cp, key_type(public)); 1542 key_free(public); 1543 xfree(cp); 1544 continue; 1545 } 1546 identity_keys[n_ids] = public; 1547 /* point to the original path, most likely the private key */ 1548 identity_files[n_ids] = xstrdup(filename); 1549 n_ids++; 1550 } 1551 options.num_identity_files = n_ids; 1552 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 1553 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 1554 1555 bzero(pwname, strlen(pwname)); 1556 xfree(pwname); 1557 bzero(pwdir, strlen(pwdir)); 1558 xfree(pwdir); 1559 } 1560 1561 static void 1562 main_sigchld_handler(int sig) 1563 { 1564 int save_errno = errno; 1565 pid_t pid; 1566 int status; 1567 1568 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 1569 (pid < 0 && errno == EINTR)) 1570 ; 1571 1572 signal(sig, main_sigchld_handler); 1573 errno = save_errno; 1574 } 1575 1576