1 /* $OpenBSD: ssh.c,v 1.374 2013/03/08 06:32:58 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 <sys/types.h> 44 #include <sys/ioctl.h> 45 #include <sys/param.h> 46 #include <sys/queue.h> 47 #include <sys/resource.h> 48 #include <sys/socket.h> 49 #include <sys/stat.h> 50 #include <sys/types.h> 51 #include <sys/time.h> 52 #include <sys/wait.h> 53 54 #include <ctype.h> 55 #include <errno.h> 56 #include <fcntl.h> 57 #include <netdb.h> 58 #include <paths.h> 59 #include <pwd.h> 60 #include <signal.h> 61 #include <stddef.h> 62 #include <stdio.h> 63 #include <stdlib.h> 64 #include <string.h> 65 #include <unistd.h> 66 67 #include <openssl/evp.h> 68 #include <openssl/err.h> 69 70 #include "xmalloc.h" 71 #include "ssh.h" 72 #include "ssh1.h" 73 #include "ssh2.h" 74 #include "canohost.h" 75 #include "compat.h" 76 #include "cipher.h" 77 #include "packet.h" 78 #include "buffer.h" 79 #include "channels.h" 80 #include "key.h" 81 #include "authfd.h" 82 #include "authfile.h" 83 #include "pathnames.h" 84 #include "dispatch.h" 85 #include "clientloop.h" 86 #include "log.h" 87 #include "readconf.h" 88 #include "sshconnect.h" 89 #include "misc.h" 90 #include "kex.h" 91 #include "mac.h" 92 #include "sshpty.h" 93 #include "match.h" 94 #include "msg.h" 95 #include "uidswap.h" 96 #include "roaming.h" 97 #include "version.h" 98 99 #ifdef ENABLE_PKCS11 100 #include "ssh-pkcs11.h" 101 #endif 102 103 extern char *__progname; 104 105 /* Flag indicating whether debug mode is on. May be set on the command line. */ 106 int debug_flag = 0; 107 108 /* Flag indicating whether a tty should be requested */ 109 int tty_flag = 0; 110 111 /* don't exec a shell */ 112 int no_shell_flag = 0; 113 114 /* 115 * Flag indicating that nothing should be read from stdin. This can be set 116 * on the command line. 117 */ 118 int stdin_null_flag = 0; 119 120 /* 121 * Flag indicating that the current process should be backgrounded and 122 * a new slave launched in the foreground for ControlPersist. 123 */ 124 int need_controlpersist_detach = 0; 125 126 /* Copies of flags for ControlPersist foreground slave */ 127 int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty; 128 129 /* 130 * Flag indicating that ssh should fork after authentication. This is useful 131 * so that the passphrase can be entered manually, and then ssh goes to the 132 * background. 133 */ 134 int fork_after_authentication_flag = 0; 135 136 /* forward stdio to remote host and port */ 137 char *stdio_forward_host = NULL; 138 int stdio_forward_port = 0; 139 140 /* 141 * General data structure for command line options and options configurable 142 * in configuration files. See readconf.h. 143 */ 144 Options options; 145 146 /* optional user configfile */ 147 char *config = NULL; 148 149 /* 150 * Name of the host we are connecting to. This is the name given on the 151 * command line, or the HostName specified for the user-supplied name in a 152 * configuration file. 153 */ 154 char *host; 155 156 /* socket address the host resolves to */ 157 struct sockaddr_storage hostaddr; 158 159 /* Private host keys. */ 160 Sensitive sensitive_data; 161 162 /* Original real UID. */ 163 uid_t original_real_uid; 164 uid_t original_effective_uid; 165 166 /* command to be executed */ 167 Buffer command; 168 169 /* Should we execute a command or invoke a subsystem? */ 170 int subsystem_flag = 0; 171 172 /* # of replies received for global requests */ 173 static int remote_forward_confirms_received = 0; 174 175 /* mux.c */ 176 extern int muxserver_sock; 177 extern u_int muxclient_command; 178 179 180 /* Prints a help message to the user. This function never returns. */ 181 182 static void 183 usage(void) 184 { 185 fprintf(stderr, 186 "usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n" 187 " [-D [bind_address:]port] [-e escape_char] [-F configfile]\n" 188 " [-I pkcs11] [-i identity_file]\n" 189 " [-L [bind_address:]port:host:hostport]\n" 190 " [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n" 191 " [-R [bind_address:]port:host:hostport] [-S ctl_path]\n" 192 " [-W host:port] [-w local_tun[:remote_tun]]\n" 193 " [user@]hostname [command]\n" 194 ); 195 exit(255); 196 } 197 198 static int ssh_session(void); 199 static int ssh_session2(void); 200 static void load_public_identity_files(void); 201 static void main_sigchld_handler(int); 202 203 /* from muxclient.c */ 204 void muxclient(const char *); 205 void muxserver_listen(void); 206 207 /* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 208 static void 209 tilde_expand_paths(char **paths, u_int num_paths) 210 { 211 u_int i; 212 char *cp; 213 214 for (i = 0; i < num_paths; i++) { 215 cp = tilde_expand_filename(paths[i], original_real_uid); 216 xfree(paths[i]); 217 paths[i] = cp; 218 } 219 } 220 221 /* 222 * Main program for the ssh client. 223 */ 224 int 225 main(int ac, char **av) 226 { 227 int i, r, opt, exit_status, use_syslog; 228 char *p, *cp, *line, *argv0, buf[MAXPATHLEN], *host_arg; 229 char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 230 struct stat st; 231 struct passwd *pw; 232 int dummy, timeout_ms; 233 extern int optind, optreset; 234 extern char *optarg; 235 struct servent *sp; 236 Forward fwd; 237 238 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 239 sanitise_stdfd(); 240 241 /* 242 * Discard other fds that are hanging around. These can cause problem 243 * with backgrounded ssh processes started by ControlPersist. 244 */ 245 closefrom(STDERR_FILENO + 1); 246 247 /* 248 * Save the original real uid. It will be needed later (uid-swapping 249 * may clobber the real uid). 250 */ 251 original_real_uid = getuid(); 252 original_effective_uid = geteuid(); 253 254 /* 255 * Use uid-swapping to give up root privileges for the duration of 256 * option processing. We will re-instantiate the rights when we are 257 * ready to create the privileged port, and will permanently drop 258 * them when the port has been created (actually, when the connection 259 * has been made, as we may need to create the port several times). 260 */ 261 PRIV_END; 262 263 /* 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 /* Get user data. */ 271 pw = getpwuid(original_real_uid); 272 if (!pw) { 273 logit("You don't exist, go away!"); 274 exit(255); 275 } 276 /* Take a copy of the returned structure. */ 277 pw = pwcopy(pw); 278 279 /* 280 * Set our umask to something reasonable, as some files are created 281 * with the default umask. This will make them world-readable but 282 * writable only by the owner, which is ok for all files for which we 283 * don't set the modes explicitly. 284 */ 285 umask(022); 286 287 /* 288 * Initialize option structure to indicate that no values have been 289 * set. 290 */ 291 initialize_options(&options); 292 293 /* Parse command-line arguments. */ 294 host = NULL; 295 use_syslog = 0; 296 argv0 = av[0]; 297 298 again: 299 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 300 "ACD:F:I:KL:MNO:PR:S:TVw:W:XYy")) != -1) { 301 switch (opt) { 302 case '1': 303 options.protocol = SSH_PROTO_1; 304 break; 305 case '2': 306 options.protocol = SSH_PROTO_2; 307 break; 308 case '4': 309 options.address_family = AF_INET; 310 break; 311 case '6': 312 options.address_family = AF_INET6; 313 break; 314 case 'n': 315 stdin_null_flag = 1; 316 break; 317 case 'f': 318 fork_after_authentication_flag = 1; 319 stdin_null_flag = 1; 320 break; 321 case 'x': 322 options.forward_x11 = 0; 323 break; 324 case 'X': 325 options.forward_x11 = 1; 326 break; 327 case 'y': 328 use_syslog = 1; 329 break; 330 case 'Y': 331 options.forward_x11 = 1; 332 options.forward_x11_trusted = 1; 333 break; 334 case 'g': 335 options.gateway_ports = 1; 336 break; 337 case 'O': 338 if (stdio_forward_host != NULL) 339 fatal("Cannot specify multiplexing " 340 "command with -W"); 341 else if (muxclient_command != 0) 342 fatal("Multiplexing command already specified"); 343 if (strcmp(optarg, "check") == 0) 344 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 345 else if (strcmp(optarg, "forward") == 0) 346 muxclient_command = SSHMUX_COMMAND_FORWARD; 347 else if (strcmp(optarg, "exit") == 0) 348 muxclient_command = SSHMUX_COMMAND_TERMINATE; 349 else if (strcmp(optarg, "stop") == 0) 350 muxclient_command = SSHMUX_COMMAND_STOP; 351 else if (strcmp(optarg, "cancel") == 0) 352 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 353 else 354 fatal("Invalid multiplex command."); 355 break; 356 case 'P': /* deprecated */ 357 options.use_privileged_port = 0; 358 break; 359 case 'a': 360 options.forward_agent = 0; 361 break; 362 case 'A': 363 options.forward_agent = 1; 364 break; 365 case 'k': 366 options.gss_deleg_creds = 0; 367 break; 368 case 'K': 369 options.gss_authentication = 1; 370 options.gss_deleg_creds = 1; 371 break; 372 case 'i': 373 if (stat(optarg, &st) < 0) { 374 fprintf(stderr, "Warning: Identity file %s " 375 "not accessible: %s.\n", optarg, 376 strerror(errno)); 377 break; 378 } 379 add_identity_file(&options, NULL, optarg, 1); 380 break; 381 case 'I': 382 #ifdef ENABLE_PKCS11 383 options.pkcs11_provider = xstrdup(optarg); 384 #else 385 fprintf(stderr, "no support for PKCS#11.\n"); 386 #endif 387 break; 388 case 't': 389 if (options.request_tty == REQUEST_TTY_YES) 390 options.request_tty = REQUEST_TTY_FORCE; 391 else 392 options.request_tty = REQUEST_TTY_YES; 393 break; 394 case 'v': 395 if (debug_flag == 0) { 396 debug_flag = 1; 397 options.log_level = SYSLOG_LEVEL_DEBUG1; 398 } else { 399 if (options.log_level < SYSLOG_LEVEL_DEBUG3) 400 options.log_level++; 401 break; 402 } 403 /* FALLTHROUGH */ 404 case 'V': 405 fprintf(stderr, "%s, %s\n", 406 SSH_VERSION, SSLeay_version(SSLEAY_VERSION)); 407 if (opt == 'V') 408 exit(0); 409 break; 410 case 'w': 411 if (options.tun_open == -1) 412 options.tun_open = SSH_TUNMODE_DEFAULT; 413 options.tun_local = a2tun(optarg, &options.tun_remote); 414 if (options.tun_local == SSH_TUNID_ERR) { 415 fprintf(stderr, 416 "Bad tun device '%s'\n", optarg); 417 exit(255); 418 } 419 break; 420 case 'W': 421 if (stdio_forward_host != NULL) 422 fatal("stdio forward already specified"); 423 if (muxclient_command != 0) 424 fatal("Cannot specify stdio forward with -O"); 425 if (parse_forward(&fwd, optarg, 1, 0)) { 426 stdio_forward_host = fwd.listen_host; 427 stdio_forward_port = fwd.listen_port; 428 xfree(fwd.connect_host); 429 } else { 430 fprintf(stderr, 431 "Bad stdio forwarding specification '%s'\n", 432 optarg); 433 exit(255); 434 } 435 options.request_tty = REQUEST_TTY_NO; 436 no_shell_flag = 1; 437 options.clear_forwardings = 1; 438 options.exit_on_forward_failure = 1; 439 break; 440 case 'q': 441 options.log_level = SYSLOG_LEVEL_QUIET; 442 break; 443 case 'e': 444 if (optarg[0] == '^' && optarg[2] == 0 && 445 (u_char) optarg[1] >= 64 && 446 (u_char) optarg[1] < 128) 447 options.escape_char = (u_char) optarg[1] & 31; 448 else if (strlen(optarg) == 1) 449 options.escape_char = (u_char) optarg[0]; 450 else if (strcmp(optarg, "none") == 0) 451 options.escape_char = SSH_ESCAPECHAR_NONE; 452 else { 453 fprintf(stderr, "Bad escape character '%s'.\n", 454 optarg); 455 exit(255); 456 } 457 break; 458 case 'c': 459 if (ciphers_valid(optarg)) { 460 /* SSH2 only */ 461 options.ciphers = xstrdup(optarg); 462 options.cipher = SSH_CIPHER_INVALID; 463 } else { 464 /* SSH1 only */ 465 options.cipher = cipher_number(optarg); 466 if (options.cipher == -1) { 467 fprintf(stderr, 468 "Unknown cipher type '%s'\n", 469 optarg); 470 exit(255); 471 } 472 if (options.cipher == SSH_CIPHER_3DES) 473 options.ciphers = "3des-cbc"; 474 else if (options.cipher == SSH_CIPHER_BLOWFISH) 475 options.ciphers = "blowfish-cbc"; 476 else 477 options.ciphers = (char *)-1; 478 } 479 break; 480 case 'm': 481 if (mac_valid(optarg)) 482 options.macs = xstrdup(optarg); 483 else { 484 fprintf(stderr, "Unknown mac type '%s'\n", 485 optarg); 486 exit(255); 487 } 488 break; 489 case 'M': 490 if (options.control_master == SSHCTL_MASTER_YES) 491 options.control_master = SSHCTL_MASTER_ASK; 492 else 493 options.control_master = SSHCTL_MASTER_YES; 494 break; 495 case 'p': 496 options.port = a2port(optarg); 497 if (options.port <= 0) { 498 fprintf(stderr, "Bad port '%s'\n", optarg); 499 exit(255); 500 } 501 break; 502 case 'l': 503 options.user = optarg; 504 break; 505 506 case 'L': 507 if (parse_forward(&fwd, optarg, 0, 0)) 508 add_local_forward(&options, &fwd); 509 else { 510 fprintf(stderr, 511 "Bad local forwarding specification '%s'\n", 512 optarg); 513 exit(255); 514 } 515 break; 516 517 case 'R': 518 if (parse_forward(&fwd, optarg, 0, 1)) { 519 add_remote_forward(&options, &fwd); 520 } else { 521 fprintf(stderr, 522 "Bad remote forwarding specification " 523 "'%s'\n", optarg); 524 exit(255); 525 } 526 break; 527 528 case 'D': 529 if (parse_forward(&fwd, optarg, 1, 0)) { 530 add_local_forward(&options, &fwd); 531 } else { 532 fprintf(stderr, 533 "Bad dynamic forwarding specification " 534 "'%s'\n", optarg); 535 exit(255); 536 } 537 break; 538 539 case 'C': 540 options.compression = 1; 541 break; 542 case 'N': 543 no_shell_flag = 1; 544 options.request_tty = REQUEST_TTY_NO; 545 break; 546 case 'T': 547 options.request_tty = REQUEST_TTY_NO; 548 break; 549 case 'o': 550 dummy = 1; 551 line = xstrdup(optarg); 552 if (process_config_line(&options, host ? host : "", 553 line, "command-line", 0, &dummy, SSHCONF_USERCONF) 554 != 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 if (subsystem_flag) { 616 fprintf(stderr, 617 "You must specify a subsystem to invoke.\n"); 618 usage(); 619 } 620 } else { 621 /* A command has been specified. Store it into the buffer. */ 622 for (i = 0; i < ac; i++) { 623 if (i) 624 buffer_append(&command, " ", 1); 625 buffer_append(&command, av[i], strlen(av[i])); 626 } 627 } 628 629 /* Cannot fork to background if no command. */ 630 if (fork_after_authentication_flag && buffer_len(&command) == 0 && 631 !no_shell_flag) 632 fatal("Cannot fork into background without a command " 633 "to execute."); 634 635 /* 636 * Initialize "log" output. Since we are the client all output 637 * actually goes to stderr. 638 */ 639 log_init(argv0, 640 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, 641 SYSLOG_FACILITY_USER, !use_syslog); 642 643 /* 644 * Read per-user configuration file. Ignore the system wide config 645 * file if the user specifies a config file on the command line. 646 */ 647 if (config != NULL) { 648 if (strcasecmp(config, "none") != 0 && 649 !read_config_file(config, host, &options, SSHCONF_USERCONF)) 650 fatal("Can't open user config file %.100s: " 651 "%.100s", config, strerror(errno)); 652 } else { 653 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 654 _PATH_SSH_USER_CONFFILE); 655 if (r > 0 && (size_t)r < sizeof(buf)) 656 (void)read_config_file(buf, host, &options, 657 SSHCONF_CHECKPERM|SSHCONF_USERCONF); 658 659 /* Read systemwide configuration file after user config. */ 660 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host, 661 &options, 0); 662 } 663 664 /* Fill configuration defaults. */ 665 fill_default_options(&options); 666 667 channel_set_af(options.address_family); 668 669 /* reinit */ 670 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog); 671 672 if (options.request_tty == REQUEST_TTY_YES || 673 options.request_tty == REQUEST_TTY_FORCE) 674 tty_flag = 1; 675 676 /* Allocate a tty by default if no command specified. */ 677 if (buffer_len(&command) == 0) 678 tty_flag = options.request_tty != REQUEST_TTY_NO; 679 680 /* Force no tty */ 681 if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0) 682 tty_flag = 0; 683 /* Do not allocate a tty if stdin is not a tty. */ 684 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 685 options.request_tty != REQUEST_TTY_FORCE) { 686 if (tty_flag) 687 logit("Pseudo-terminal will not be allocated because " 688 "stdin is not a terminal."); 689 tty_flag = 0; 690 } 691 692 if (options.user == NULL) 693 options.user = xstrdup(pw->pw_name); 694 695 /* Get default port if port has not been set. */ 696 if (options.port == 0) { 697 sp = getservbyname(SSH_SERVICE_NAME, "tcp"); 698 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT; 699 } 700 701 /* preserve host name given on command line for %n expansion */ 702 host_arg = host; 703 if (options.hostname != NULL) { 704 host = percent_expand(options.hostname, 705 "h", host, (char *)NULL); 706 } 707 708 if (gethostname(thishost, sizeof(thishost)) == -1) 709 fatal("gethostname: %s", strerror(errno)); 710 strlcpy(shorthost, thishost, sizeof(shorthost)); 711 shorthost[strcspn(thishost, ".")] = '\0'; 712 snprintf(portstr, sizeof(portstr), "%d", options.port); 713 714 if (options.local_command != NULL) { 715 debug3("expanding LocalCommand: %s", options.local_command); 716 cp = options.local_command; 717 options.local_command = percent_expand(cp, "d", pw->pw_dir, 718 "h", host, "l", thishost, "n", host_arg, "r", options.user, 719 "p", portstr, "u", pw->pw_name, "L", shorthost, 720 (char *)NULL); 721 debug3("expanded LocalCommand: %s", options.local_command); 722 xfree(cp); 723 } 724 725 /* force lowercase for hostkey matching */ 726 if (options.host_key_alias != NULL) { 727 for (p = options.host_key_alias; *p; p++) 728 if (isupper(*p)) 729 *p = (char)tolower(*p); 730 } 731 732 if (options.proxy_command != NULL && 733 strcmp(options.proxy_command, "none") == 0) { 734 xfree(options.proxy_command); 735 options.proxy_command = NULL; 736 } 737 if (options.control_path != NULL && 738 strcmp(options.control_path, "none") == 0) { 739 xfree(options.control_path); 740 options.control_path = NULL; 741 } 742 743 if (options.control_path != NULL) { 744 cp = tilde_expand_filename(options.control_path, 745 original_real_uid); 746 xfree(options.control_path); 747 options.control_path = percent_expand(cp, "h", host, 748 "l", thishost, "n", host_arg, "r", options.user, 749 "p", portstr, "u", pw->pw_name, "L", shorthost, 750 (char *)NULL); 751 xfree(cp); 752 } 753 if (muxclient_command != 0 && options.control_path == NULL) 754 fatal("No ControlPath specified for \"-O\" command"); 755 if (options.control_path != NULL) 756 muxclient(options.control_path); 757 758 timeout_ms = options.connection_timeout * 1000; 759 760 /* Open a connection to the remote host. */ 761 if (ssh_connect(host, &hostaddr, options.port, 762 options.address_family, options.connection_attempts, &timeout_ms, 763 options.tcp_keep_alive, 764 original_effective_uid == 0 && options.use_privileged_port, 765 options.proxy_command) != 0) 766 exit(255); 767 768 if (timeout_ms > 0) 769 debug3("timeout: %d ms remain after connect", timeout_ms); 770 771 /* 772 * If we successfully made the connection, load the host private key 773 * in case we will need it later for combined rsa-rhosts 774 * authentication. This must be done before releasing extra 775 * privileges, because the file is only readable by root. 776 * If we cannot access the private keys, load the public keys 777 * instead and try to execute the ssh-keysign helper instead. 778 */ 779 sensitive_data.nkeys = 0; 780 sensitive_data.keys = NULL; 781 sensitive_data.external_keysign = 0; 782 if (options.rhosts_rsa_authentication || 783 options.hostbased_authentication) { 784 sensitive_data.nkeys = 7; 785 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 786 sizeof(Key)); 787 788 PRIV_START; 789 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, 790 _PATH_HOST_KEY_FILE, "", NULL, NULL); 791 sensitive_data.keys[1] = key_load_private_cert(KEY_DSA, 792 _PATH_HOST_DSA_KEY_FILE, "", NULL); 793 sensitive_data.keys[2] = key_load_private_cert(KEY_ECDSA, 794 _PATH_HOST_ECDSA_KEY_FILE, "", NULL); 795 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA, 796 _PATH_HOST_RSA_KEY_FILE, "", NULL); 797 sensitive_data.keys[4] = key_load_private_type(KEY_DSA, 798 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); 799 sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA, 800 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL); 801 sensitive_data.keys[6] = key_load_private_type(KEY_RSA, 802 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); 803 PRIV_END; 804 805 if (options.hostbased_authentication == 1 && 806 sensitive_data.keys[0] == NULL && 807 sensitive_data.keys[4] == NULL && 808 sensitive_data.keys[5] == NULL && 809 sensitive_data.keys[6] == NULL) { 810 sensitive_data.keys[1] = key_load_cert( 811 _PATH_HOST_DSA_KEY_FILE); 812 sensitive_data.keys[2] = key_load_cert( 813 _PATH_HOST_ECDSA_KEY_FILE); 814 sensitive_data.keys[3] = key_load_cert( 815 _PATH_HOST_RSA_KEY_FILE); 816 sensitive_data.keys[4] = key_load_public( 817 _PATH_HOST_DSA_KEY_FILE, NULL); 818 sensitive_data.keys[5] = key_load_public( 819 _PATH_HOST_ECDSA_KEY_FILE, NULL); 820 sensitive_data.keys[6] = key_load_public( 821 _PATH_HOST_RSA_KEY_FILE, NULL); 822 sensitive_data.external_keysign = 1; 823 } 824 } 825 /* 826 * Get rid of any extra privileges that we may have. We will no 827 * longer need them. Also, extra privileges could make it very hard 828 * to read identity files and other non-world-readable files from the 829 * user's home directory if it happens to be on a NFS volume where 830 * root is mapped to nobody. 831 */ 832 if (original_effective_uid == 0) { 833 PRIV_START; 834 permanently_set_uid(pw); 835 } 836 837 /* 838 * Now that we are back to our own permissions, create ~/.ssh 839 * directory if it doesn't already exist. 840 */ 841 if (config == NULL) { 842 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 843 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 844 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) 845 if (mkdir(buf, 0700) < 0) 846 error("Could not create directory '%.200s'.", 847 buf); 848 } 849 850 /* load options.identity_files */ 851 load_public_identity_files(); 852 853 /* Expand ~ in known host file names. */ 854 tilde_expand_paths(options.system_hostfiles, 855 options.num_system_hostfiles); 856 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 857 858 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 859 signal(SIGCHLD, main_sigchld_handler); 860 861 /* Log into the remote system. Never returns if the login fails. */ 862 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, 863 options.port, pw, timeout_ms); 864 865 if (packet_connection_is_on_socket()) { 866 verbose("Authenticated to %s ([%s]:%d).", host, 867 get_remote_ipaddr(), get_remote_port()); 868 } else { 869 verbose("Authenticated to %s (via proxy).", host); 870 } 871 872 /* We no longer need the private host keys. Clear them now. */ 873 if (sensitive_data.nkeys != 0) { 874 for (i = 0; i < sensitive_data.nkeys; i++) { 875 if (sensitive_data.keys[i] != NULL) { 876 /* Destroys contents safely */ 877 debug3("clear hostkey %d", i); 878 key_free(sensitive_data.keys[i]); 879 sensitive_data.keys[i] = NULL; 880 } 881 } 882 xfree(sensitive_data.keys); 883 } 884 for (i = 0; i < options.num_identity_files; i++) { 885 if (options.identity_files[i]) { 886 xfree(options.identity_files[i]); 887 options.identity_files[i] = NULL; 888 } 889 if (options.identity_keys[i]) { 890 key_free(options.identity_keys[i]); 891 options.identity_keys[i] = NULL; 892 } 893 } 894 895 exit_status = compat20 ? ssh_session2() : ssh_session(); 896 packet_close(); 897 898 if (options.control_path != NULL && muxserver_sock != -1) 899 unlink(options.control_path); 900 901 /* Kill ProxyCommand if it is running. */ 902 ssh_kill_proxy_command(); 903 904 return exit_status; 905 } 906 907 static void 908 control_persist_detach(void) 909 { 910 pid_t pid; 911 int devnull; 912 913 debug("%s: backgrounding master process", __func__); 914 915 /* 916 * master (current process) into the background, and make the 917 * foreground process a client of the backgrounded master. 918 */ 919 switch ((pid = fork())) { 920 case -1: 921 fatal("%s: fork: %s", __func__, strerror(errno)); 922 case 0: 923 /* Child: master process continues mainloop */ 924 break; 925 default: 926 /* Parent: set up mux slave to connect to backgrounded master */ 927 debug2("%s: background process is %ld", __func__, (long)pid); 928 stdin_null_flag = ostdin_null_flag; 929 options.request_tty = orequest_tty; 930 tty_flag = otty_flag; 931 close(muxserver_sock); 932 muxserver_sock = -1; 933 options.control_master = SSHCTL_MASTER_NO; 934 muxclient(options.control_path); 935 /* muxclient() doesn't return on success. */ 936 fatal("Failed to connect to new control master"); 937 } 938 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 939 error("%s: open(\"/dev/null\"): %s", __func__, 940 strerror(errno)); 941 } else { 942 if (dup2(devnull, STDIN_FILENO) == -1 || 943 dup2(devnull, STDOUT_FILENO) == -1) 944 error("%s: dup2: %s", __func__, strerror(errno)); 945 if (devnull > STDERR_FILENO) 946 close(devnull); 947 } 948 setproctitle("%s [mux]", options.control_path); 949 } 950 951 /* Do fork() after authentication. Used by "ssh -f" */ 952 static void 953 fork_postauth(void) 954 { 955 if (need_controlpersist_detach) 956 control_persist_detach(); 957 debug("forking to background"); 958 fork_after_authentication_flag = 0; 959 if (daemon(1, 1) < 0) 960 fatal("daemon() failed: %.200s", strerror(errno)); 961 } 962 963 /* Callback for remote forward global requests */ 964 static void 965 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) 966 { 967 Forward *rfwd = (Forward *)ctxt; 968 969 /* XXX verbose() on failure? */ 970 debug("remote forward %s for: listen %d, connect %s:%d", 971 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 972 rfwd->listen_port, rfwd->connect_host, rfwd->connect_port); 973 if (rfwd->listen_port == 0) { 974 if (type == SSH2_MSG_REQUEST_SUCCESS) { 975 rfwd->allocated_port = packet_get_int(); 976 logit("Allocated port %u for remote forward to %s:%d", 977 rfwd->allocated_port, 978 rfwd->connect_host, rfwd->connect_port); 979 channel_update_permitted_opens(rfwd->handle, 980 rfwd->allocated_port); 981 } else { 982 channel_update_permitted_opens(rfwd->handle, -1); 983 } 984 } 985 986 if (type == SSH2_MSG_REQUEST_FAILURE) { 987 if (options.exit_on_forward_failure) 988 fatal("Error: remote port forwarding failed for " 989 "listen port %d", rfwd->listen_port); 990 else 991 logit("Warning: remote port forwarding failed for " 992 "listen port %d", rfwd->listen_port); 993 } 994 if (++remote_forward_confirms_received == options.num_remote_forwards) { 995 debug("All remote forwarding requests processed"); 996 if (fork_after_authentication_flag) 997 fork_postauth(); 998 } 999 } 1000 1001 static void 1002 client_cleanup_stdio_fwd(int id, void *arg) 1003 { 1004 debug("stdio forwarding: done"); 1005 cleanup_exit(0); 1006 } 1007 1008 static void 1009 ssh_init_stdio_forwarding(void) 1010 { 1011 Channel *c; 1012 int in, out; 1013 1014 if (stdio_forward_host == NULL) 1015 return; 1016 if (!compat20) 1017 fatal("stdio forwarding require Protocol 2"); 1018 1019 debug3("%s: %s:%d", __func__, stdio_forward_host, stdio_forward_port); 1020 1021 if ((in = dup(STDIN_FILENO)) < 0 || 1022 (out = dup(STDOUT_FILENO)) < 0) 1023 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1024 if ((c = channel_connect_stdio_fwd(stdio_forward_host, 1025 stdio_forward_port, in, out)) == NULL) 1026 fatal("%s: channel_connect_stdio_fwd failed", __func__); 1027 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0); 1028 } 1029 1030 static void 1031 ssh_init_forwarding(void) 1032 { 1033 int success = 0; 1034 int i; 1035 1036 /* Initiate local TCP/IP port forwardings. */ 1037 for (i = 0; i < options.num_local_forwards; i++) { 1038 debug("Local connections to %.200s:%d forwarded to remote " 1039 "address %.200s:%d", 1040 (options.local_forwards[i].listen_host == NULL) ? 1041 (options.gateway_ports ? "*" : "LOCALHOST") : 1042 options.local_forwards[i].listen_host, 1043 options.local_forwards[i].listen_port, 1044 options.local_forwards[i].connect_host, 1045 options.local_forwards[i].connect_port); 1046 success += channel_setup_local_fwd_listener( 1047 options.local_forwards[i].listen_host, 1048 options.local_forwards[i].listen_port, 1049 options.local_forwards[i].connect_host, 1050 options.local_forwards[i].connect_port, 1051 options.gateway_ports); 1052 } 1053 if (i > 0 && success != i && options.exit_on_forward_failure) 1054 fatal("Could not request local forwarding."); 1055 if (i > 0 && success == 0) 1056 error("Could not request local forwarding."); 1057 1058 /* Initiate remote TCP/IP port forwardings. */ 1059 for (i = 0; i < options.num_remote_forwards; i++) { 1060 debug("Remote connections from %.200s:%d forwarded to " 1061 "local address %.200s:%d", 1062 (options.remote_forwards[i].listen_host == NULL) ? 1063 "LOCALHOST" : options.remote_forwards[i].listen_host, 1064 options.remote_forwards[i].listen_port, 1065 options.remote_forwards[i].connect_host, 1066 options.remote_forwards[i].connect_port); 1067 options.remote_forwards[i].handle = 1068 channel_request_remote_forwarding( 1069 options.remote_forwards[i].listen_host, 1070 options.remote_forwards[i].listen_port, 1071 options.remote_forwards[i].connect_host, 1072 options.remote_forwards[i].connect_port); 1073 if (options.remote_forwards[i].handle < 0) { 1074 if (options.exit_on_forward_failure) 1075 fatal("Could not request remote forwarding."); 1076 else 1077 logit("Warning: Could not request remote " 1078 "forwarding."); 1079 } else { 1080 client_register_global_confirm(ssh_confirm_remote_forward, 1081 &options.remote_forwards[i]); 1082 } 1083 } 1084 1085 /* Initiate tunnel forwarding. */ 1086 if (options.tun_open != SSH_TUNMODE_NO) { 1087 if (client_request_tun_fwd(options.tun_open, 1088 options.tun_local, options.tun_remote) == -1) { 1089 if (options.exit_on_forward_failure) 1090 fatal("Could not request tunnel forwarding."); 1091 else 1092 error("Could not request tunnel forwarding."); 1093 } 1094 } 1095 } 1096 1097 static void 1098 check_agent_present(void) 1099 { 1100 if (options.forward_agent) { 1101 /* Clear agent forwarding if we don't have an agent. */ 1102 if (!ssh_agent_present()) 1103 options.forward_agent = 0; 1104 } 1105 } 1106 1107 static int 1108 ssh_session(void) 1109 { 1110 int type; 1111 int interactive = 0; 1112 int have_tty = 0; 1113 struct winsize ws; 1114 char *cp; 1115 const char *display; 1116 1117 /* Enable compression if requested. */ 1118 if (options.compression) { 1119 debug("Requesting compression at level %d.", 1120 options.compression_level); 1121 1122 if (options.compression_level < 1 || 1123 options.compression_level > 9) 1124 fatal("Compression level must be from 1 (fast) to " 1125 "9 (slow, best)."); 1126 1127 /* Send the request. */ 1128 packet_start(SSH_CMSG_REQUEST_COMPRESSION); 1129 packet_put_int(options.compression_level); 1130 packet_send(); 1131 packet_write_wait(); 1132 type = packet_read(); 1133 if (type == SSH_SMSG_SUCCESS) 1134 packet_start_compression(options.compression_level); 1135 else if (type == SSH_SMSG_FAILURE) 1136 logit("Warning: Remote host refused compression."); 1137 else 1138 packet_disconnect("Protocol error waiting for " 1139 "compression response."); 1140 } 1141 /* Allocate a pseudo tty if appropriate. */ 1142 if (tty_flag) { 1143 debug("Requesting pty."); 1144 1145 /* Start the packet. */ 1146 packet_start(SSH_CMSG_REQUEST_PTY); 1147 1148 /* Store TERM in the packet. There is no limit on the 1149 length of the string. */ 1150 cp = getenv("TERM"); 1151 if (!cp) 1152 cp = ""; 1153 packet_put_cstring(cp); 1154 1155 /* Store window size in the packet. */ 1156 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 1157 memset(&ws, 0, sizeof(ws)); 1158 packet_put_int((u_int)ws.ws_row); 1159 packet_put_int((u_int)ws.ws_col); 1160 packet_put_int((u_int)ws.ws_xpixel); 1161 packet_put_int((u_int)ws.ws_ypixel); 1162 1163 /* Store tty modes in the packet. */ 1164 tty_make_modes(fileno(stdin), NULL); 1165 1166 /* Send the packet, and wait for it to leave. */ 1167 packet_send(); 1168 packet_write_wait(); 1169 1170 /* Read response from the server. */ 1171 type = packet_read(); 1172 if (type == SSH_SMSG_SUCCESS) { 1173 interactive = 1; 1174 have_tty = 1; 1175 } else if (type == SSH_SMSG_FAILURE) 1176 logit("Warning: Remote host failed or refused to " 1177 "allocate a pseudo tty."); 1178 else 1179 packet_disconnect("Protocol error waiting for pty " 1180 "request response."); 1181 } 1182 /* Request X11 forwarding if enabled and DISPLAY is set. */ 1183 display = getenv("DISPLAY"); 1184 if (options.forward_x11 && display != NULL) { 1185 char *proto, *data; 1186 /* Get reasonable local authentication information. */ 1187 client_x11_get_proto(display, options.xauth_location, 1188 options.forward_x11_trusted, 1189 options.forward_x11_timeout, 1190 &proto, &data); 1191 /* Request forwarding with authentication spoofing. */ 1192 debug("Requesting X11 forwarding with authentication " 1193 "spoofing."); 1194 x11_request_forwarding_with_spoofing(0, display, proto, 1195 data, 0); 1196 /* Read response from the server. */ 1197 type = packet_read(); 1198 if (type == SSH_SMSG_SUCCESS) { 1199 interactive = 1; 1200 } else if (type == SSH_SMSG_FAILURE) { 1201 logit("Warning: Remote host denied X11 forwarding."); 1202 } else { 1203 packet_disconnect("Protocol error waiting for X11 " 1204 "forwarding"); 1205 } 1206 } 1207 /* Tell the packet module whether this is an interactive session. */ 1208 packet_set_interactive(interactive, 1209 options.ip_qos_interactive, options.ip_qos_bulk); 1210 1211 /* Request authentication agent forwarding if appropriate. */ 1212 check_agent_present(); 1213 1214 if (options.forward_agent) { 1215 debug("Requesting authentication agent forwarding."); 1216 auth_request_forwarding(); 1217 1218 /* Read response from the server. */ 1219 type = packet_read(); 1220 packet_check_eom(); 1221 if (type != SSH_SMSG_SUCCESS) 1222 logit("Warning: Remote host denied authentication agent forwarding."); 1223 } 1224 1225 /* Initiate port forwardings. */ 1226 ssh_init_stdio_forwarding(); 1227 ssh_init_forwarding(); 1228 1229 /* Execute a local command */ 1230 if (options.local_command != NULL && 1231 options.permit_local_command) 1232 ssh_local_cmd(options.local_command); 1233 1234 /* 1235 * If requested and we are not interested in replies to remote 1236 * forwarding requests, then let ssh continue in the background. 1237 */ 1238 if (fork_after_authentication_flag) { 1239 if (options.exit_on_forward_failure && 1240 options.num_remote_forwards > 0) { 1241 debug("deferring postauth fork until remote forward " 1242 "confirmation received"); 1243 } else 1244 fork_postauth(); 1245 } 1246 1247 /* 1248 * If a command was specified on the command line, execute the 1249 * command now. Otherwise request the server to start a shell. 1250 */ 1251 if (buffer_len(&command) > 0) { 1252 int len = buffer_len(&command); 1253 if (len > 900) 1254 len = 900; 1255 debug("Sending command: %.*s", len, 1256 (u_char *)buffer_ptr(&command)); 1257 packet_start(SSH_CMSG_EXEC_CMD); 1258 packet_put_string(buffer_ptr(&command), buffer_len(&command)); 1259 packet_send(); 1260 packet_write_wait(); 1261 } else { 1262 debug("Requesting shell."); 1263 packet_start(SSH_CMSG_EXEC_SHELL); 1264 packet_send(); 1265 packet_write_wait(); 1266 } 1267 1268 /* Enter the interactive session. */ 1269 return client_loop(have_tty, tty_flag ? 1270 options.escape_char : SSH_ESCAPECHAR_NONE, 0); 1271 } 1272 1273 /* request pty/x11/agent/tcpfwd/shell for channel */ 1274 static void 1275 ssh_session2_setup(int id, int success, void *arg) 1276 { 1277 extern char **environ; 1278 const char *display; 1279 int interactive = tty_flag; 1280 1281 if (!success) 1282 return; /* No need for error message, channels code sens one */ 1283 1284 display = getenv("DISPLAY"); 1285 if (options.forward_x11 && display != NULL) { 1286 char *proto, *data; 1287 /* Get reasonable local authentication information. */ 1288 client_x11_get_proto(display, options.xauth_location, 1289 options.forward_x11_trusted, 1290 options.forward_x11_timeout, &proto, &data); 1291 /* Request forwarding with authentication spoofing. */ 1292 debug("Requesting X11 forwarding with authentication " 1293 "spoofing."); 1294 x11_request_forwarding_with_spoofing(id, display, proto, 1295 data, 1); 1296 client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN); 1297 /* XXX exit_on_forward_failure */ 1298 interactive = 1; 1299 } 1300 1301 check_agent_present(); 1302 if (options.forward_agent) { 1303 debug("Requesting authentication agent forwarding."); 1304 channel_request_start(id, "auth-agent-req@openssh.com", 0); 1305 packet_send(); 1306 } 1307 1308 /* Tell the packet module whether this is an interactive session. */ 1309 packet_set_interactive(interactive, 1310 options.ip_qos_interactive, options.ip_qos_bulk); 1311 1312 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), 1313 NULL, fileno(stdin), &command, environ); 1314 } 1315 1316 /* open new channel for a session */ 1317 static int 1318 ssh_session2_open(void) 1319 { 1320 Channel *c; 1321 int window, packetmax, in, out, err; 1322 1323 if (stdin_null_flag) { 1324 in = open(_PATH_DEVNULL, O_RDONLY); 1325 } else { 1326 in = dup(STDIN_FILENO); 1327 } 1328 out = dup(STDOUT_FILENO); 1329 err = dup(STDERR_FILENO); 1330 1331 if (in < 0 || out < 0 || err < 0) 1332 fatal("dup() in/out/err failed"); 1333 1334 /* enable nonblocking unless tty */ 1335 if (!isatty(in)) 1336 set_nonblock(in); 1337 if (!isatty(out)) 1338 set_nonblock(out); 1339 if (!isatty(err)) 1340 set_nonblock(err); 1341 1342 window = CHAN_SES_WINDOW_DEFAULT; 1343 packetmax = CHAN_SES_PACKET_DEFAULT; 1344 if (tty_flag) { 1345 window >>= 1; 1346 packetmax >>= 1; 1347 } 1348 c = channel_new( 1349 "session", SSH_CHANNEL_OPENING, in, out, err, 1350 window, packetmax, CHAN_EXTENDED_WRITE, 1351 "client-session", /*nonblock*/0); 1352 1353 debug3("ssh_session2_open: channel_new: %d", c->self); 1354 1355 channel_send_open(c->self); 1356 if (!no_shell_flag) 1357 channel_register_open_confirm(c->self, 1358 ssh_session2_setup, NULL); 1359 1360 return c->self; 1361 } 1362 1363 static int 1364 ssh_session2(void) 1365 { 1366 int id = -1; 1367 1368 /* XXX should be pre-session */ 1369 if (!options.control_persist) 1370 ssh_init_stdio_forwarding(); 1371 ssh_init_forwarding(); 1372 1373 /* Start listening for multiplex clients */ 1374 muxserver_listen(); 1375 1376 /* 1377 * If we are in control persist mode and have a working mux listen 1378 * socket, then prepare to background ourselves and have a foreground 1379 * client attach as a control slave. 1380 * NB. we must save copies of the flags that we override for 1381 * the backgrounding, since we defer attachment of the slave until 1382 * after the connection is fully established (in particular, 1383 * async rfwd replies have been received for ExitOnForwardFailure). 1384 */ 1385 if (options.control_persist && muxserver_sock != -1) { 1386 ostdin_null_flag = stdin_null_flag; 1387 ono_shell_flag = no_shell_flag; 1388 orequest_tty = options.request_tty; 1389 otty_flag = tty_flag; 1390 stdin_null_flag = 1; 1391 no_shell_flag = 1; 1392 tty_flag = 0; 1393 if (!fork_after_authentication_flag) 1394 need_controlpersist_detach = 1; 1395 fork_after_authentication_flag = 1; 1396 } 1397 /* 1398 * ControlPersist mux listen socket setup failed, attempt the 1399 * stdio forward setup that we skipped earlier. 1400 */ 1401 if (options.control_persist && muxserver_sock == -1) 1402 ssh_init_stdio_forwarding(); 1403 1404 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) 1405 id = ssh_session2_open(); 1406 1407 /* If we don't expect to open a new session, then disallow it */ 1408 if (options.control_master == SSHCTL_MASTER_NO && 1409 (datafellows & SSH_NEW_OPENSSH)) { 1410 debug("Requesting no-more-sessions@openssh.com"); 1411 packet_start(SSH2_MSG_GLOBAL_REQUEST); 1412 packet_put_cstring("no-more-sessions@openssh.com"); 1413 packet_put_char(0); 1414 packet_send(); 1415 } 1416 1417 /* Execute a local command */ 1418 if (options.local_command != NULL && 1419 options.permit_local_command) 1420 ssh_local_cmd(options.local_command); 1421 1422 /* 1423 * If requested and we are not interested in replies to remote 1424 * forwarding requests, then let ssh continue in the background. 1425 */ 1426 if (fork_after_authentication_flag) { 1427 if (options.exit_on_forward_failure && 1428 options.num_remote_forwards > 0) { 1429 debug("deferring postauth fork until remote forward " 1430 "confirmation received"); 1431 } else 1432 fork_postauth(); 1433 } 1434 1435 if (options.use_roaming) 1436 request_roaming(); 1437 1438 return client_loop(tty_flag, tty_flag ? 1439 options.escape_char : SSH_ESCAPECHAR_NONE, id); 1440 } 1441 1442 static void 1443 load_public_identity_files(void) 1444 { 1445 char *filename, *cp, thishost[NI_MAXHOST]; 1446 char *pwdir = NULL, *pwname = NULL; 1447 int i = 0; 1448 Key *public; 1449 struct passwd *pw; 1450 u_int n_ids; 1451 char *identity_files[SSH_MAX_IDENTITY_FILES]; 1452 Key *identity_keys[SSH_MAX_IDENTITY_FILES]; 1453 #ifdef ENABLE_PKCS11 1454 Key **keys; 1455 int nkeys; 1456 #endif /* PKCS11 */ 1457 1458 n_ids = 0; 1459 bzero(identity_files, sizeof(identity_files)); 1460 bzero(identity_keys, sizeof(identity_keys)); 1461 1462 #ifdef ENABLE_PKCS11 1463 if (options.pkcs11_provider != NULL && 1464 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 1465 (pkcs11_init(!options.batch_mode) == 0) && 1466 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 1467 &keys)) > 0) { 1468 for (i = 0; i < nkeys; i++) { 1469 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 1470 key_free(keys[i]); 1471 continue; 1472 } 1473 identity_keys[n_ids] = keys[i]; 1474 identity_files[n_ids] = 1475 xstrdup(options.pkcs11_provider); /* XXX */ 1476 n_ids++; 1477 } 1478 xfree(keys); 1479 } 1480 #endif /* ENABLE_PKCS11 */ 1481 if ((pw = getpwuid(original_real_uid)) == NULL) 1482 fatal("load_public_identity_files: getpwuid failed"); 1483 pwname = xstrdup(pw->pw_name); 1484 pwdir = xstrdup(pw->pw_dir); 1485 if (gethostname(thishost, sizeof(thishost)) == -1) 1486 fatal("load_public_identity_files: gethostname: %s", 1487 strerror(errno)); 1488 for (i = 0; i < options.num_identity_files; i++) { 1489 if (n_ids >= SSH_MAX_IDENTITY_FILES || 1490 strcasecmp(options.identity_files[i], "none") == 0) { 1491 xfree(options.identity_files[i]); 1492 continue; 1493 } 1494 cp = tilde_expand_filename(options.identity_files[i], 1495 original_real_uid); 1496 filename = percent_expand(cp, "d", pwdir, 1497 "u", pwname, "l", thishost, "h", host, 1498 "r", options.user, (char *)NULL); 1499 xfree(cp); 1500 public = key_load_public(filename, NULL); 1501 debug("identity file %s type %d", filename, 1502 public ? public->type : -1); 1503 xfree(options.identity_files[i]); 1504 identity_files[n_ids] = filename; 1505 identity_keys[n_ids] = public; 1506 1507 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 1508 continue; 1509 1510 /* Try to add the certificate variant too */ 1511 xasprintf(&cp, "%s-cert", filename); 1512 public = key_load_public(cp, NULL); 1513 debug("identity file %s type %d", cp, 1514 public ? public->type : -1); 1515 if (public == NULL) { 1516 xfree(cp); 1517 continue; 1518 } 1519 if (!key_is_cert(public)) { 1520 debug("%s: key %s type %s is not a certificate", 1521 __func__, cp, key_type(public)); 1522 key_free(public); 1523 xfree(cp); 1524 continue; 1525 } 1526 identity_keys[n_ids] = public; 1527 /* point to the original path, most likely the private key */ 1528 identity_files[n_ids] = xstrdup(filename); 1529 n_ids++; 1530 } 1531 options.num_identity_files = n_ids; 1532 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 1533 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 1534 1535 bzero(pwname, strlen(pwname)); 1536 xfree(pwname); 1537 bzero(pwdir, strlen(pwdir)); 1538 xfree(pwdir); 1539 } 1540 1541 static void 1542 main_sigchld_handler(int sig) 1543 { 1544 int save_errno = errno; 1545 pid_t pid; 1546 int status; 1547 1548 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 1549 (pid < 0 && errno == EINTR)) 1550 ; 1551 1552 signal(sig, main_sigchld_handler); 1553 errno = save_errno; 1554 } 1555 1556