ssh.c revision 323120
1/* $OpenBSD: ssh.c,v 1.445 2016/07/17 04:20:16 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: stable/10/crypto/openssh/ssh.c 323120 2017-09-01 21:24:32Z des $"); 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/socket.h> 53#include <sys/wait.h> 54 55#include <ctype.h> 56#include <errno.h> 57#include <fcntl.h> 58#include <netdb.h> 59#ifdef HAVE_PATHS_H 60#include <paths.h> 61#endif 62#include <pwd.h> 63#include <signal.h> 64#include <stdarg.h> 65#include <stddef.h> 66#include <stdio.h> 67#include <stdlib.h> 68#include <string.h> 69#include <unistd.h> 70#include <limits.h> 71#include <locale.h> 72 73#include <netinet/in.h> 74#include <arpa/inet.h> 75 76#ifdef WITH_OPENSSL 77#include <openssl/evp.h> 78#include <openssl/err.h> 79#endif 80#include "openbsd-compat/openssl-compat.h" 81#include "openbsd-compat/sys-queue.h" 82 83#include "xmalloc.h" 84#include "ssh.h" 85#include "ssh1.h" 86#include "ssh2.h" 87#include "canohost.h" 88#include "compat.h" 89#include "cipher.h" 90#include "digest.h" 91#include "packet.h" 92#include "buffer.h" 93#include "channels.h" 94#include "key.h" 95#include "authfd.h" 96#include "authfile.h" 97#include "pathnames.h" 98#include "dispatch.h" 99#include "clientloop.h" 100#include "log.h" 101#include "misc.h" 102#include "readconf.h" 103#include "sshconnect.h" 104#include "kex.h" 105#include "mac.h" 106#include "sshpty.h" 107#include "match.h" 108#include "msg.h" 109#include "uidswap.h" 110#include "version.h" 111#include "ssherr.h" 112#include "myproposal.h" 113 114#ifdef ENABLE_PKCS11 115#include "ssh-pkcs11.h" 116#endif 117 118extern char *__progname; 119 120/* Saves a copy of argv for setproctitle emulation */ 121#ifndef HAVE_SETPROCTITLE 122static char **saved_av; 123#endif 124 125/* Flag indicating whether debug mode is on. May be set on the command line. */ 126int debug_flag = 0; 127 128/* Flag indicating whether a tty should be requested */ 129int tty_flag = 0; 130 131/* don't exec a shell */ 132int no_shell_flag = 0; 133 134/* 135 * Flag indicating that nothing should be read from stdin. This can be set 136 * on the command line. 137 */ 138int stdin_null_flag = 0; 139 140/* 141 * Flag indicating that the current process should be backgrounded and 142 * a new slave launched in the foreground for ControlPersist. 143 */ 144int need_controlpersist_detach = 0; 145 146/* Copies of flags for ControlPersist foreground slave */ 147int ostdin_null_flag, ono_shell_flag, otty_flag, orequest_tty; 148 149/* 150 * Flag indicating that ssh should fork after authentication. This is useful 151 * so that the passphrase can be entered manually, and then ssh goes to the 152 * background. 153 */ 154int fork_after_authentication_flag = 0; 155 156/* 157 * General data structure for command line options and options configurable 158 * in configuration files. See readconf.h. 159 */ 160Options options; 161 162/* optional user configfile */ 163char *config = NULL; 164 165/* 166 * Name of the host we are connecting to. This is the name given on the 167 * command line, or the HostName specified for the user-supplied name in a 168 * configuration file. 169 */ 170char *host; 171 172/* socket address the host resolves to */ 173struct sockaddr_storage hostaddr; 174 175/* Private host keys. */ 176Sensitive sensitive_data; 177 178/* Original real UID. */ 179uid_t original_real_uid; 180uid_t original_effective_uid; 181 182/* command to be executed */ 183Buffer command; 184 185/* Should we execute a command or invoke a subsystem? */ 186int subsystem_flag = 0; 187 188/* # of replies received for global requests */ 189static int remote_forward_confirms_received = 0; 190 191/* mux.c */ 192extern int muxserver_sock; 193extern u_int muxclient_command; 194 195/* Prints a help message to the user. This function never returns. */ 196 197static void 198usage(void) 199{ 200 fprintf(stderr, 201"usage: ssh [-1246AaCfGgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n" 202" [-D [bind_address:]port] [-E log_file] [-e escape_char]\n" 203" [-F configfile] [-I pkcs11] [-i identity_file]\n" 204" [-J [user@]host[:port]] [-L address] [-l login_name] [-m mac_spec]\n" 205" [-O ctl_cmd] [-o option] [-p port] [-Q query_option] [-R address]\n" 206" [-S ctl_path] [-W host:port] [-w local_tun[:remote_tun]]\n" 207" [user@]hostname [command]\n" 208 ); 209 exit(255); 210} 211 212static int ssh_session(void); 213static int ssh_session2(void); 214static void load_public_identity_files(void); 215static void main_sigchld_handler(int); 216 217/* from muxclient.c */ 218void muxclient(const char *); 219void muxserver_listen(void); 220 221/* ~/ expand a list of paths. NB. assumes path[n] is heap-allocated. */ 222static void 223tilde_expand_paths(char **paths, u_int num_paths) 224{ 225 u_int i; 226 char *cp; 227 228 for (i = 0; i < num_paths; i++) { 229 cp = tilde_expand_filename(paths[i], original_real_uid); 230 free(paths[i]); 231 paths[i] = cp; 232 } 233} 234 235/* 236 * Attempt to resolve a host name / port to a set of addresses and 237 * optionally return any CNAMEs encountered along the way. 238 * Returns NULL on failure. 239 * NB. this function must operate with a options having undefined members. 240 */ 241static struct addrinfo * 242resolve_host(const char *name, int port, int logerr, char *cname, size_t clen) 243{ 244 char strport[NI_MAXSERV]; 245 struct addrinfo hints, *res; 246 int gaierr, loglevel = SYSLOG_LEVEL_DEBUG1; 247 248 if (port <= 0) 249 port = default_ssh_port(); 250 251 snprintf(strport, sizeof strport, "%d", port); 252 memset(&hints, 0, sizeof(hints)); 253 hints.ai_family = options.address_family == -1 ? 254 AF_UNSPEC : options.address_family; 255 hints.ai_socktype = SOCK_STREAM; 256 if (cname != NULL) 257 hints.ai_flags = AI_CANONNAME; 258 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 259 if (logerr || (gaierr != EAI_NONAME && gaierr != EAI_NODATA)) 260 loglevel = SYSLOG_LEVEL_ERROR; 261 do_log2(loglevel, "%s: Could not resolve hostname %.100s: %s", 262 __progname, name, ssh_gai_strerror(gaierr)); 263 return NULL; 264 } 265 if (cname != NULL && res->ai_canonname != NULL) { 266 if (strlcpy(cname, res->ai_canonname, clen) >= clen) { 267 error("%s: host \"%s\" cname \"%s\" too long (max %lu)", 268 __func__, name, res->ai_canonname, (u_long)clen); 269 if (clen > 0) 270 *cname = '\0'; 271 } 272 } 273 return res; 274} 275 276/* 277 * Attempt to resolve a numeric host address / port to a single address. 278 * Returns a canonical address string. 279 * Returns NULL on failure. 280 * NB. this function must operate with a options having undefined members. 281 */ 282static struct addrinfo * 283resolve_addr(const char *name, int port, char *caddr, size_t clen) 284{ 285 char addr[NI_MAXHOST], strport[NI_MAXSERV]; 286 struct addrinfo hints, *res; 287 int gaierr; 288 289 if (port <= 0) 290 port = default_ssh_port(); 291 snprintf(strport, sizeof strport, "%u", port); 292 memset(&hints, 0, sizeof(hints)); 293 hints.ai_family = options.address_family == -1 ? 294 AF_UNSPEC : options.address_family; 295 hints.ai_socktype = SOCK_STREAM; 296 hints.ai_flags = AI_NUMERICHOST|AI_NUMERICSERV; 297 if ((gaierr = getaddrinfo(name, strport, &hints, &res)) != 0) { 298 debug2("%s: could not resolve name %.100s as address: %s", 299 __func__, name, ssh_gai_strerror(gaierr)); 300 return NULL; 301 } 302 if (res == NULL) { 303 debug("%s: getaddrinfo %.100s returned no addresses", 304 __func__, name); 305 return NULL; 306 } 307 if (res->ai_next != NULL) { 308 debug("%s: getaddrinfo %.100s returned multiple addresses", 309 __func__, name); 310 goto fail; 311 } 312 if ((gaierr = getnameinfo(res->ai_addr, res->ai_addrlen, 313 addr, sizeof(addr), NULL, 0, NI_NUMERICHOST)) != 0) { 314 debug("%s: Could not format address for name %.100s: %s", 315 __func__, name, ssh_gai_strerror(gaierr)); 316 goto fail; 317 } 318 if (strlcpy(caddr, addr, clen) >= clen) { 319 error("%s: host \"%s\" addr \"%s\" too long (max %lu)", 320 __func__, name, addr, (u_long)clen); 321 if (clen > 0) 322 *caddr = '\0'; 323 fail: 324 freeaddrinfo(res); 325 return NULL; 326 } 327 return res; 328} 329 330/* 331 * Check whether the cname is a permitted replacement for the hostname 332 * and perform the replacement if it is. 333 * NB. this function must operate with a options having undefined members. 334 */ 335static int 336check_follow_cname(int direct, char **namep, const char *cname) 337{ 338 int i; 339 struct allowed_cname *rule; 340 341 if (*cname == '\0' || options.num_permitted_cnames == 0 || 342 strcmp(*namep, cname) == 0) 343 return 0; 344 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 345 return 0; 346 /* 347 * Don't attempt to canonicalize names that will be interpreted by 348 * a proxy or jump host unless the user specifically requests so. 349 */ 350 if (!direct && 351 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 352 return 0; 353 debug3("%s: check \"%s\" CNAME \"%s\"", __func__, *namep, cname); 354 for (i = 0; i < options.num_permitted_cnames; i++) { 355 rule = options.permitted_cnames + i; 356 if (match_pattern_list(*namep, rule->source_list, 1) != 1 || 357 match_pattern_list(cname, rule->target_list, 1) != 1) 358 continue; 359 verbose("Canonicalized DNS aliased hostname " 360 "\"%s\" => \"%s\"", *namep, cname); 361 free(*namep); 362 *namep = xstrdup(cname); 363 return 1; 364 } 365 return 0; 366} 367 368/* 369 * Attempt to resolve the supplied hostname after applying the user's 370 * canonicalization rules. Returns the address list for the host or NULL 371 * if no name was found after canonicalization. 372 * NB. this function must operate with a options having undefined members. 373 */ 374static struct addrinfo * 375resolve_canonicalize(char **hostp, int port) 376{ 377 int i, direct, ndots; 378 char *cp, *fullhost, newname[NI_MAXHOST]; 379 struct addrinfo *addrs; 380 381 if (options.canonicalize_hostname == SSH_CANONICALISE_NO) 382 return NULL; 383 384 /* 385 * Don't attempt to canonicalize names that will be interpreted by 386 * a proxy unless the user specifically requests so. 387 */ 388 direct = option_clear_or_none(options.proxy_command) && 389 options.jump_host == NULL; 390 if (!direct && 391 options.canonicalize_hostname != SSH_CANONICALISE_ALWAYS) 392 return NULL; 393 394 /* Try numeric hostnames first */ 395 if ((addrs = resolve_addr(*hostp, port, 396 newname, sizeof(newname))) != NULL) { 397 debug2("%s: hostname %.100s is address", __func__, *hostp); 398 if (strcasecmp(*hostp, newname) != 0) { 399 debug2("%s: canonicalised address \"%s\" => \"%s\"", 400 __func__, *hostp, newname); 401 free(*hostp); 402 *hostp = xstrdup(newname); 403 } 404 return addrs; 405 } 406 407 /* If domain name is anchored, then resolve it now */ 408 if ((*hostp)[strlen(*hostp) - 1] == '.') { 409 debug3("%s: name is fully qualified", __func__); 410 fullhost = xstrdup(*hostp); 411 if ((addrs = resolve_host(fullhost, port, 0, 412 newname, sizeof(newname))) != NULL) 413 goto found; 414 free(fullhost); 415 goto notfound; 416 } 417 418 /* Don't apply canonicalization to sufficiently-qualified hostnames */ 419 ndots = 0; 420 for (cp = *hostp; *cp != '\0'; cp++) { 421 if (*cp == '.') 422 ndots++; 423 } 424 if (ndots > options.canonicalize_max_dots) { 425 debug3("%s: not canonicalizing hostname \"%s\" (max dots %d)", 426 __func__, *hostp, options.canonicalize_max_dots); 427 return NULL; 428 } 429 /* Attempt each supplied suffix */ 430 for (i = 0; i < options.num_canonical_domains; i++) { 431 *newname = '\0'; 432 xasprintf(&fullhost, "%s.%s.", *hostp, 433 options.canonical_domains[i]); 434 debug3("%s: attempting \"%s\" => \"%s\"", __func__, 435 *hostp, fullhost); 436 if ((addrs = resolve_host(fullhost, port, 0, 437 newname, sizeof(newname))) == NULL) { 438 free(fullhost); 439 continue; 440 } 441 found: 442 /* Remove trailing '.' */ 443 fullhost[strlen(fullhost) - 1] = '\0'; 444 /* Follow CNAME if requested */ 445 if (!check_follow_cname(direct, &fullhost, newname)) { 446 debug("Canonicalized hostname \"%s\" => \"%s\"", 447 *hostp, fullhost); 448 } 449 free(*hostp); 450 *hostp = fullhost; 451 return addrs; 452 } 453 notfound: 454 if (!options.canonicalize_fallback_local) 455 fatal("%s: Could not resolve host \"%s\"", __progname, *hostp); 456 debug2("%s: host %s not found in any suffix", __func__, *hostp); 457 return NULL; 458} 459 460/* 461 * Read per-user configuration file. Ignore the system wide config 462 * file if the user specifies a config file on the command line. 463 */ 464static void 465process_config_files(const char *host_arg, struct passwd *pw, int post_canon) 466{ 467 char buf[PATH_MAX]; 468 int r; 469 470 if (config != NULL) { 471 if (strcasecmp(config, "none") != 0 && 472 !read_config_file(config, pw, host, host_arg, &options, 473 SSHCONF_USERCONF | (post_canon ? SSHCONF_POSTCANON : 0))) 474 fatal("Can't open user config file %.100s: " 475 "%.100s", config, strerror(errno)); 476 } else { 477 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir, 478 _PATH_SSH_USER_CONFFILE); 479 if (r > 0 && (size_t)r < sizeof(buf)) 480 (void)read_config_file(buf, pw, host, host_arg, 481 &options, SSHCONF_CHECKPERM | SSHCONF_USERCONF | 482 (post_canon ? SSHCONF_POSTCANON : 0)); 483 484 /* Read systemwide configuration file after user config. */ 485 (void)read_config_file(_PATH_HOST_CONFIG_FILE, pw, 486 host, host_arg, &options, 487 post_canon ? SSHCONF_POSTCANON : 0); 488 } 489} 490 491/* Rewrite the port number in an addrinfo list of addresses */ 492static void 493set_addrinfo_port(struct addrinfo *addrs, int port) 494{ 495 struct addrinfo *addr; 496 497 for (addr = addrs; addr != NULL; addr = addr->ai_next) { 498 switch (addr->ai_family) { 499 case AF_INET: 500 ((struct sockaddr_in *)addr->ai_addr)-> 501 sin_port = htons(port); 502 break; 503 case AF_INET6: 504 ((struct sockaddr_in6 *)addr->ai_addr)-> 505 sin6_port = htons(port); 506 break; 507 } 508 } 509} 510 511/* 512 * Main program for the ssh client. 513 */ 514int 515main(int ac, char **av) 516{ 517 struct ssh *ssh = NULL; 518 int i, r, opt, exit_status, use_syslog, direct, config_test = 0; 519 char *p, *cp, *line, *argv0, buf[PATH_MAX], *host_arg, *logfile; 520 char thishost[NI_MAXHOST], shorthost[NI_MAXHOST], portstr[NI_MAXSERV]; 521 char cname[NI_MAXHOST], uidstr[32], *conn_hash_hex; 522 struct stat st; 523 struct passwd *pw; 524 int timeout_ms; 525 extern int optind, optreset; 526 extern char *optarg; 527 struct Forward fwd; 528 struct addrinfo *addrs = NULL; 529 struct ssh_digest_ctx *md; 530 u_char conn_hash[SSH_DIGEST_MAX_LENGTH]; 531 532 ssh_malloc_init(); /* must be called before any mallocs */ 533 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ 534 sanitise_stdfd(); 535 536 __progname = ssh_get_progname(av[0]); 537 538#ifndef HAVE_SETPROCTITLE 539 /* Prepare for later setproctitle emulation */ 540 /* Save argv so it isn't clobbered by setproctitle() emulation */ 541 saved_av = xcalloc(ac + 1, sizeof(*saved_av)); 542 for (i = 0; i < ac; i++) 543 saved_av[i] = xstrdup(av[i]); 544 saved_av[i] = NULL; 545 compat_init_setproctitle(ac, av); 546 av = saved_av; 547#endif 548 549 /* 550 * Discard other fds that are hanging around. These can cause problem 551 * with backgrounded ssh processes started by ControlPersist. 552 */ 553 closefrom(STDERR_FILENO + 1); 554 555 /* 556 * Save the original real uid. It will be needed later (uid-swapping 557 * may clobber the real uid). 558 */ 559 original_real_uid = getuid(); 560 original_effective_uid = geteuid(); 561 562 /* 563 * Use uid-swapping to give up root privileges for the duration of 564 * option processing. We will re-instantiate the rights when we are 565 * ready to create the privileged port, and will permanently drop 566 * them when the port has been created (actually, when the connection 567 * has been made, as we may need to create the port several times). 568 */ 569 PRIV_END; 570 571#ifdef HAVE_SETRLIMIT 572 /* If we are installed setuid root be careful to not drop core. */ 573 if (original_real_uid != original_effective_uid) { 574 struct rlimit rlim; 575 rlim.rlim_cur = rlim.rlim_max = 0; 576 if (setrlimit(RLIMIT_CORE, &rlim) < 0) 577 fatal("setrlimit failed: %.100s", strerror(errno)); 578 } 579#endif 580 /* Get user data. */ 581 pw = getpwuid(original_real_uid); 582 if (!pw) { 583 logit("No user exists for uid %lu", (u_long)original_real_uid); 584 exit(255); 585 } 586 /* Take a copy of the returned structure. */ 587 pw = pwcopy(pw); 588 589 /* 590 * Set our umask to something reasonable, as some files are created 591 * with the default umask. This will make them world-readable but 592 * writable only by the owner, which is ok for all files for which we 593 * don't set the modes explicitly. 594 */ 595 umask(022); 596 597 setlocale(LC_CTYPE, ""); 598 599 /* 600 * Initialize option structure to indicate that no values have been 601 * set. 602 */ 603 initialize_options(&options); 604 605 /* Parse command-line arguments. */ 606 host = NULL; 607 use_syslog = 0; 608 logfile = NULL; 609 argv0 = av[0]; 610 611 again: 612 while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx" 613 "ACD:E:F:GI:J:KL:MNO:PQ:R:S:TVw:W:XYy")) != -1) { 614 switch (opt) { 615 case '1': 616 options.protocol = SSH_PROTO_1; 617 break; 618 case '2': 619 options.protocol = SSH_PROTO_2; 620 break; 621 case '4': 622 options.address_family = AF_INET; 623 break; 624 case '6': 625 options.address_family = AF_INET6; 626 break; 627 case 'n': 628 stdin_null_flag = 1; 629 break; 630 case 'f': 631 fork_after_authentication_flag = 1; 632 stdin_null_flag = 1; 633 break; 634 case 'x': 635 options.forward_x11 = 0; 636 break; 637 case 'X': 638 options.forward_x11 = 1; 639 break; 640 case 'y': 641 use_syslog = 1; 642 break; 643 case 'E': 644 logfile = optarg; 645 break; 646 case 'G': 647 config_test = 1; 648 break; 649 case 'Y': 650 options.forward_x11 = 1; 651 options.forward_x11_trusted = 1; 652 break; 653 case 'g': 654 options.fwd_opts.gateway_ports = 1; 655 break; 656 case 'O': 657 if (options.stdio_forward_host != NULL) 658 fatal("Cannot specify multiplexing " 659 "command with -W"); 660 else if (muxclient_command != 0) 661 fatal("Multiplexing command already specified"); 662 if (strcmp(optarg, "check") == 0) 663 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK; 664 else if (strcmp(optarg, "forward") == 0) 665 muxclient_command = SSHMUX_COMMAND_FORWARD; 666 else if (strcmp(optarg, "exit") == 0) 667 muxclient_command = SSHMUX_COMMAND_TERMINATE; 668 else if (strcmp(optarg, "stop") == 0) 669 muxclient_command = SSHMUX_COMMAND_STOP; 670 else if (strcmp(optarg, "cancel") == 0) 671 muxclient_command = SSHMUX_COMMAND_CANCEL_FWD; 672 else 673 fatal("Invalid multiplex command."); 674 break; 675 case 'P': /* deprecated */ 676 options.use_privileged_port = 0; 677 break; 678 case 'Q': 679 cp = NULL; 680 if (strcmp(optarg, "cipher") == 0) 681 cp = cipher_alg_list('\n', 0); 682 else if (strcmp(optarg, "cipher-auth") == 0) 683 cp = cipher_alg_list('\n', 1); 684 else if (strcmp(optarg, "mac") == 0) 685 cp = mac_alg_list('\n'); 686 else if (strcmp(optarg, "kex") == 0) 687 cp = kex_alg_list('\n'); 688 else if (strcmp(optarg, "key") == 0) 689 cp = key_alg_list(0, 0); 690 else if (strcmp(optarg, "key-cert") == 0) 691 cp = key_alg_list(1, 0); 692 else if (strcmp(optarg, "key-plain") == 0) 693 cp = key_alg_list(0, 1); 694 else if (strcmp(optarg, "protocol-version") == 0) { 695#ifdef WITH_SSH1 696 cp = xstrdup("1\n2"); 697#else 698 cp = xstrdup("2"); 699#endif 700 } 701 if (cp == NULL) 702 fatal("Unsupported query \"%s\"", optarg); 703 printf("%s\n", cp); 704 free(cp); 705 exit(0); 706 break; 707 case 'a': 708 options.forward_agent = 0; 709 break; 710 case 'A': 711 options.forward_agent = 1; 712 break; 713 case 'k': 714 options.gss_deleg_creds = 0; 715 break; 716 case 'K': 717 options.gss_authentication = 1; 718 options.gss_deleg_creds = 1; 719 break; 720 case 'i': 721 p = tilde_expand_filename(optarg, original_real_uid); 722 if (stat(p, &st) < 0) 723 fprintf(stderr, "Warning: Identity file %s " 724 "not accessible: %s.\n", p, 725 strerror(errno)); 726 else 727 add_identity_file(&options, NULL, p, 1); 728 free(p); 729 break; 730 case 'I': 731#ifdef ENABLE_PKCS11 732 free(options.pkcs11_provider); 733 options.pkcs11_provider = xstrdup(optarg); 734#else 735 fprintf(stderr, "no support for PKCS#11.\n"); 736#endif 737 break; 738 case 'J': 739 if (options.jump_host != NULL) 740 fatal("Only a single -J option permitted"); 741 if (options.proxy_command != NULL) 742 fatal("Cannot specify -J with ProxyCommand"); 743 if (parse_jump(optarg, &options, 1) == -1) 744 fatal("Invalid -J argument"); 745 options.proxy_command = xstrdup("none"); 746 break; 747 case 't': 748 if (options.request_tty == REQUEST_TTY_YES) 749 options.request_tty = REQUEST_TTY_FORCE; 750 else 751 options.request_tty = REQUEST_TTY_YES; 752 break; 753 case 'v': 754 if (debug_flag == 0) { 755 debug_flag = 1; 756 options.log_level = SYSLOG_LEVEL_DEBUG1; 757 } else { 758 if (options.log_level < SYSLOG_LEVEL_DEBUG3) { 759 debug_flag++; 760 options.log_level++; 761 } 762 } 763 break; 764 case 'V': 765 if (options.version_addendum && 766 *options.version_addendum != '\0') 767 fprintf(stderr, "%s %s, %s\n", SSH_RELEASE, 768 options.version_addendum, 769 OPENSSL_VERSION); 770 else 771 fprintf(stderr, "%s, %s\n", SSH_RELEASE, 772 OPENSSL_VERSION); 773 if (opt == 'V') 774 exit(0); 775 break; 776 case 'w': 777 if (options.tun_open == -1) 778 options.tun_open = SSH_TUNMODE_DEFAULT; 779 options.tun_local = a2tun(optarg, &options.tun_remote); 780 if (options.tun_local == SSH_TUNID_ERR) { 781 fprintf(stderr, 782 "Bad tun device '%s'\n", optarg); 783 exit(255); 784 } 785 break; 786 case 'W': 787 if (options.stdio_forward_host != NULL) 788 fatal("stdio forward already specified"); 789 if (muxclient_command != 0) 790 fatal("Cannot specify stdio forward with -O"); 791 if (parse_forward(&fwd, optarg, 1, 0)) { 792 options.stdio_forward_host = fwd.listen_host; 793 options.stdio_forward_port = fwd.listen_port; 794 free(fwd.connect_host); 795 } else { 796 fprintf(stderr, 797 "Bad stdio forwarding specification '%s'\n", 798 optarg); 799 exit(255); 800 } 801 options.request_tty = REQUEST_TTY_NO; 802 no_shell_flag = 1; 803 break; 804 case 'q': 805 options.log_level = SYSLOG_LEVEL_QUIET; 806 break; 807 case 'e': 808 if (optarg[0] == '^' && optarg[2] == 0 && 809 (u_char) optarg[1] >= 64 && 810 (u_char) optarg[1] < 128) 811 options.escape_char = (u_char) optarg[1] & 31; 812 else if (strlen(optarg) == 1) 813 options.escape_char = (u_char) optarg[0]; 814 else if (strcmp(optarg, "none") == 0) 815 options.escape_char = SSH_ESCAPECHAR_NONE; 816 else { 817 fprintf(stderr, "Bad escape character '%s'.\n", 818 optarg); 819 exit(255); 820 } 821 break; 822 case 'c': 823 if (ciphers_valid(*optarg == '+' ? 824 optarg + 1 : optarg)) { 825 /* SSH2 only */ 826 free(options.ciphers); 827 options.ciphers = xstrdup(optarg); 828 options.cipher = SSH_CIPHER_INVALID; 829 break; 830 } 831 /* SSH1 only */ 832 options.cipher = cipher_number(optarg); 833 if (options.cipher == -1) { 834 fprintf(stderr, "Unknown cipher type '%s'\n", 835 optarg); 836 exit(255); 837 } 838 if (options.cipher == SSH_CIPHER_3DES) 839 options.ciphers = xstrdup("3des-cbc"); 840 else if (options.cipher == SSH_CIPHER_BLOWFISH) 841 options.ciphers = xstrdup("blowfish-cbc"); 842 else 843 options.ciphers = xstrdup(KEX_CLIENT_ENCRYPT); 844 break; 845 case 'm': 846 if (mac_valid(optarg)) { 847 free(options.macs); 848 options.macs = xstrdup(optarg); 849 } else { 850 fprintf(stderr, "Unknown mac type '%s'\n", 851 optarg); 852 exit(255); 853 } 854 break; 855 case 'M': 856 if (options.control_master == SSHCTL_MASTER_YES) 857 options.control_master = SSHCTL_MASTER_ASK; 858 else 859 options.control_master = SSHCTL_MASTER_YES; 860 break; 861 case 'p': 862 options.port = a2port(optarg); 863 if (options.port <= 0) { 864 fprintf(stderr, "Bad port '%s'\n", optarg); 865 exit(255); 866 } 867 break; 868 case 'l': 869 options.user = optarg; 870 break; 871 872 case 'L': 873 if (parse_forward(&fwd, optarg, 0, 0)) 874 add_local_forward(&options, &fwd); 875 else { 876 fprintf(stderr, 877 "Bad local forwarding specification '%s'\n", 878 optarg); 879 exit(255); 880 } 881 break; 882 883 case 'R': 884 if (parse_forward(&fwd, optarg, 0, 1)) { 885 add_remote_forward(&options, &fwd); 886 } else { 887 fprintf(stderr, 888 "Bad remote forwarding specification " 889 "'%s'\n", optarg); 890 exit(255); 891 } 892 break; 893 894 case 'D': 895 if (parse_forward(&fwd, optarg, 1, 0)) { 896 add_local_forward(&options, &fwd); 897 } else { 898 fprintf(stderr, 899 "Bad dynamic forwarding specification " 900 "'%s'\n", optarg); 901 exit(255); 902 } 903 break; 904 905 case 'C': 906 options.compression = 1; 907 break; 908 case 'N': 909 no_shell_flag = 1; 910 options.request_tty = REQUEST_TTY_NO; 911 break; 912 case 'T': 913 options.request_tty = REQUEST_TTY_NO; 914 break; 915 case 'o': 916 line = xstrdup(optarg); 917 if (process_config_line(&options, pw, 918 host ? host : "", host ? host : "", line, 919 "command-line", 0, NULL, SSHCONF_USERCONF) != 0) 920 exit(255); 921 free(line); 922 break; 923 case 's': 924 subsystem_flag = 1; 925 break; 926 case 'S': 927 free(options.control_path); 928 options.control_path = xstrdup(optarg); 929 break; 930 case 'b': 931 options.bind_address = optarg; 932 break; 933 case 'F': 934 config = optarg; 935 break; 936 default: 937 usage(); 938 } 939 } 940 941 ac -= optind; 942 av += optind; 943 944 if (ac > 0 && !host) { 945 if (strrchr(*av, '@')) { 946 p = xstrdup(*av); 947 cp = strrchr(p, '@'); 948 if (cp == NULL || cp == p) 949 usage(); 950 options.user = p; 951 *cp = '\0'; 952 host = xstrdup(++cp); 953 } else 954 host = xstrdup(*av); 955 if (ac > 1) { 956 optind = optreset = 1; 957 goto again; 958 } 959 ac--, av++; 960 } 961 962 /* Check that we got a host name. */ 963 if (!host) 964 usage(); 965 966 host_arg = xstrdup(host); 967 968#ifdef WITH_OPENSSL 969 OpenSSL_add_all_algorithms(); 970 ERR_load_crypto_strings(); 971#endif 972 973 /* Initialize the command to execute on remote host. */ 974 buffer_init(&command); 975 976 /* 977 * Save the command to execute on the remote host in a buffer. There 978 * is no limit on the length of the command, except by the maximum 979 * packet size. Also sets the tty flag if there is no command. 980 */ 981 if (!ac) { 982 /* No command specified - execute shell on a tty. */ 983 if (subsystem_flag) { 984 fprintf(stderr, 985 "You must specify a subsystem to invoke.\n"); 986 usage(); 987 } 988 } else { 989 /* A command has been specified. Store it into the buffer. */ 990 for (i = 0; i < ac; i++) { 991 if (i) 992 buffer_append(&command, " ", 1); 993 buffer_append(&command, av[i], strlen(av[i])); 994 } 995 } 996 997 /* Cannot fork to background if no command. */ 998 if (fork_after_authentication_flag && buffer_len(&command) == 0 && 999 !no_shell_flag) 1000 fatal("Cannot fork into background without a command " 1001 "to execute."); 1002 1003 /* 1004 * Initialize "log" output. Since we are the client all output 1005 * goes to stderr unless otherwise specified by -y or -E. 1006 */ 1007 if (use_syslog && logfile != NULL) 1008 fatal("Can't specify both -y and -E"); 1009 if (logfile != NULL) 1010 log_redirect_stderr_to(logfile); 1011 log_init(argv0, 1012 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, 1013 SYSLOG_FACILITY_USER, !use_syslog); 1014 1015 if (debug_flag) 1016 /* version_addendum is always NULL at this point */ 1017 logit("%s, %s", SSH_RELEASE, OPENSSL_VERSION); 1018 1019 /* Parse the configuration files */ 1020 process_config_files(host_arg, pw, 0); 1021 1022 /* Hostname canonicalisation needs a few options filled. */ 1023 fill_default_options_for_canonicalization(&options); 1024 1025 /* If the user has replaced the hostname then take it into use now */ 1026 if (options.hostname != NULL) { 1027 /* NB. Please keep in sync with readconf.c:match_cfg_line() */ 1028 cp = percent_expand(options.hostname, 1029 "h", host, (char *)NULL); 1030 free(host); 1031 host = cp; 1032 free(options.hostname); 1033 options.hostname = xstrdup(host); 1034 } 1035 1036 /* If canonicalization requested then try to apply it */ 1037 lowercase(host); 1038 if (options.canonicalize_hostname != SSH_CANONICALISE_NO) 1039 addrs = resolve_canonicalize(&host, options.port); 1040 1041 /* 1042 * If CanonicalizePermittedCNAMEs have been specified but 1043 * other canonicalization did not happen (by not being requested 1044 * or by failing with fallback) then the hostname may still be changed 1045 * as a result of CNAME following. 1046 * 1047 * Try to resolve the bare hostname name using the system resolver's 1048 * usual search rules and then apply the CNAME follow rules. 1049 * 1050 * Skip the lookup if a ProxyCommand is being used unless the user 1051 * has specifically requested canonicalisation for this case via 1052 * CanonicalizeHostname=always 1053 */ 1054 direct = option_clear_or_none(options.proxy_command) && 1055 options.jump_host == NULL; 1056 if (addrs == NULL && options.num_permitted_cnames != 0 && (direct || 1057 options.canonicalize_hostname == SSH_CANONICALISE_ALWAYS)) { 1058 if ((addrs = resolve_host(host, options.port, 1059 option_clear_or_none(options.proxy_command), 1060 cname, sizeof(cname))) == NULL) { 1061 /* Don't fatal proxied host names not in the DNS */ 1062 if (option_clear_or_none(options.proxy_command)) 1063 cleanup_exit(255); /* logged in resolve_host */ 1064 } else 1065 check_follow_cname(direct, &host, cname); 1066 } 1067 1068 /* 1069 * If canonicalisation is enabled then re-parse the configuration 1070 * files as new stanzas may match. 1071 */ 1072 if (options.canonicalize_hostname != 0) { 1073 debug("Re-reading configuration after hostname " 1074 "canonicalisation"); 1075 free(options.hostname); 1076 options.hostname = xstrdup(host); 1077 process_config_files(host_arg, pw, 1); 1078 /* 1079 * Address resolution happens early with canonicalisation 1080 * enabled and the port number may have changed since, so 1081 * reset it in address list 1082 */ 1083 if (addrs != NULL && options.port > 0) 1084 set_addrinfo_port(addrs, options.port); 1085 } 1086 1087 /* Fill configuration defaults. */ 1088 fill_default_options(&options); 1089 1090 /* 1091 * If ProxyJump option specified, then construct a ProxyCommand now. 1092 */ 1093 if (options.jump_host != NULL) { 1094 char port_s[8]; 1095 1096 /* Consistency check */ 1097 if (options.proxy_command != NULL) 1098 fatal("inconsistent options: ProxyCommand+ProxyJump"); 1099 /* Never use FD passing for ProxyJump */ 1100 options.proxy_use_fdpass = 0; 1101 snprintf(port_s, sizeof(port_s), "%d", options.jump_port); 1102 xasprintf(&options.proxy_command, 1103 "ssh%s%s%s%s%s%s%s%s%s%.*s -W %%h:%%p %s", 1104 /* Optional "-l user" argument if jump_user set */ 1105 options.jump_user == NULL ? "" : " -l ", 1106 options.jump_user == NULL ? "" : options.jump_user, 1107 /* Optional "-p port" argument if jump_port set */ 1108 options.jump_port <= 0 ? "" : " -p ", 1109 options.jump_port <= 0 ? "" : port_s, 1110 /* Optional additional jump hosts ",..." */ 1111 options.jump_extra == NULL ? "" : " -J ", 1112 options.jump_extra == NULL ? "" : options.jump_extra, 1113 /* Optional "-F" argumment if -F specified */ 1114 config == NULL ? "" : " -F ", 1115 config == NULL ? "" : config, 1116 /* Optional "-v" arguments if -v set */ 1117 debug_flag ? " -" : "", 1118 debug_flag, "vvv", 1119 /* Mandatory hostname */ 1120 options.jump_host); 1121 debug("Setting implicit ProxyCommand from ProxyJump: %s", 1122 options.proxy_command); 1123 } 1124 1125 if (options.port == 0) 1126 options.port = default_ssh_port(); 1127 channel_set_af(options.address_family); 1128 1129 /* Tidy and check options */ 1130 if (options.host_key_alias != NULL) 1131 lowercase(options.host_key_alias); 1132 if (options.proxy_command != NULL && 1133 strcmp(options.proxy_command, "-") == 0 && 1134 options.proxy_use_fdpass) 1135 fatal("ProxyCommand=- and ProxyUseFDPass are incompatible"); 1136 if (options.control_persist && 1137 options.update_hostkeys == SSH_UPDATE_HOSTKEYS_ASK) { 1138 debug("UpdateHostKeys=ask is incompatible with ControlPersist; " 1139 "disabling"); 1140 options.update_hostkeys = 0; 1141 } 1142 if (options.connection_attempts <= 0) 1143 fatal("Invalid number of ConnectionAttempts"); 1144#ifndef HAVE_CYGWIN 1145 if (original_effective_uid != 0) 1146 options.use_privileged_port = 0; 1147#endif 1148 1149 /* reinit */ 1150 log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog); 1151 1152 if (options.request_tty == REQUEST_TTY_YES || 1153 options.request_tty == REQUEST_TTY_FORCE) 1154 tty_flag = 1; 1155 1156 /* Allocate a tty by default if no command specified. */ 1157 if (buffer_len(&command) == 0) 1158 tty_flag = options.request_tty != REQUEST_TTY_NO; 1159 1160 /* Force no tty */ 1161 if (options.request_tty == REQUEST_TTY_NO || muxclient_command != 0) 1162 tty_flag = 0; 1163 /* Do not allocate a tty if stdin is not a tty. */ 1164 if ((!isatty(fileno(stdin)) || stdin_null_flag) && 1165 options.request_tty != REQUEST_TTY_FORCE) { 1166 if (tty_flag) 1167 logit("Pseudo-terminal will not be allocated because " 1168 "stdin is not a terminal."); 1169 tty_flag = 0; 1170 } 1171 1172 seed_rng(); 1173 1174 if (options.user == NULL) 1175 options.user = xstrdup(pw->pw_name); 1176 1177 if (gethostname(thishost, sizeof(thishost)) == -1) 1178 fatal("gethostname: %s", strerror(errno)); 1179 strlcpy(shorthost, thishost, sizeof(shorthost)); 1180 shorthost[strcspn(thishost, ".")] = '\0'; 1181 snprintf(portstr, sizeof(portstr), "%d", options.port); 1182 snprintf(uidstr, sizeof(uidstr), "%d", pw->pw_uid); 1183 1184 /* Find canonic host name. */ 1185 if (strchr(host, '.') == 0) { 1186 struct addrinfo hints; 1187 struct addrinfo *ai = NULL; 1188 int errgai; 1189 memset(&hints, 0, sizeof(hints)); 1190 hints.ai_family = options.address_family; 1191 hints.ai_flags = AI_CANONNAME; 1192 hints.ai_socktype = SOCK_STREAM; 1193 errgai = getaddrinfo(host, NULL, &hints, &ai); 1194 if (errgai == 0) { 1195 if (ai->ai_canonname != NULL) 1196 host = xstrdup(ai->ai_canonname); 1197 freeaddrinfo(ai); 1198 } 1199 } 1200 1201 if ((md = ssh_digest_start(SSH_DIGEST_SHA1)) == NULL || 1202 ssh_digest_update(md, thishost, strlen(thishost)) < 0 || 1203 ssh_digest_update(md, host, strlen(host)) < 0 || 1204 ssh_digest_update(md, portstr, strlen(portstr)) < 0 || 1205 ssh_digest_update(md, options.user, strlen(options.user)) < 0 || 1206 ssh_digest_final(md, conn_hash, sizeof(conn_hash)) < 0) 1207 fatal("%s: mux digest failed", __func__); 1208 ssh_digest_free(md); 1209 conn_hash_hex = tohex(conn_hash, ssh_digest_bytes(SSH_DIGEST_SHA1)); 1210 1211 if (options.local_command != NULL) { 1212 debug3("expanding LocalCommand: %s", options.local_command); 1213 cp = options.local_command; 1214 options.local_command = percent_expand(cp, 1215 "C", conn_hash_hex, 1216 "L", shorthost, 1217 "d", pw->pw_dir, 1218 "h", host, 1219 "l", thishost, 1220 "n", host_arg, 1221 "p", portstr, 1222 "r", options.user, 1223 "u", pw->pw_name, 1224 (char *)NULL); 1225 debug3("expanded LocalCommand: %s", options.local_command); 1226 free(cp); 1227 } 1228 1229 if (options.control_path != NULL) { 1230 cp = tilde_expand_filename(options.control_path, 1231 original_real_uid); 1232 free(options.control_path); 1233 options.control_path = percent_expand(cp, 1234 "C", conn_hash_hex, 1235 "L", shorthost, 1236 "h", host, 1237 "l", thishost, 1238 "n", host_arg, 1239 "p", portstr, 1240 "r", options.user, 1241 "u", pw->pw_name, 1242 "i", uidstr, 1243 (char *)NULL); 1244 free(cp); 1245 } 1246 free(conn_hash_hex); 1247 1248 if (config_test) { 1249 dump_client_config(&options, host); 1250 exit(0); 1251 } 1252 1253 if (muxclient_command != 0 && options.control_path == NULL) 1254 fatal("No ControlPath specified for \"-O\" command"); 1255 if (options.control_path != NULL) 1256 muxclient(options.control_path); 1257 1258 /* 1259 * If hostname canonicalisation was not enabled, then we may not 1260 * have yet resolved the hostname. Do so now. 1261 */ 1262 if (addrs == NULL && options.proxy_command == NULL) { 1263 debug2("resolving \"%s\" port %d", host, options.port); 1264 if ((addrs = resolve_host(host, options.port, 1, 1265 cname, sizeof(cname))) == NULL) 1266 cleanup_exit(255); /* resolve_host logs the error */ 1267 } 1268 1269 timeout_ms = options.connection_timeout * 1000; 1270 1271 /* Open a connection to the remote host. */ 1272 if (ssh_connect(host, addrs, &hostaddr, options.port, 1273 options.address_family, options.connection_attempts, 1274 &timeout_ms, options.tcp_keep_alive, 1275 options.use_privileged_port) != 0) 1276 exit(255); 1277 1278 if (addrs != NULL) 1279 freeaddrinfo(addrs); 1280 1281 packet_set_timeout(options.server_alive_interval, 1282 options.server_alive_count_max); 1283 1284 ssh = active_state; /* XXX */ 1285 1286 if (timeout_ms > 0) 1287 debug3("timeout: %d ms remain after connect", timeout_ms); 1288 1289 /* 1290 * If we successfully made the connection, load the host private key 1291 * in case we will need it later for combined rsa-rhosts 1292 * authentication. This must be done before releasing extra 1293 * privileges, because the file is only readable by root. 1294 * If we cannot access the private keys, load the public keys 1295 * instead and try to execute the ssh-keysign helper instead. 1296 */ 1297 sensitive_data.nkeys = 0; 1298 sensitive_data.keys = NULL; 1299 sensitive_data.external_keysign = 0; 1300 if (options.rhosts_rsa_authentication || 1301 options.hostbased_authentication) { 1302 sensitive_data.nkeys = 9; 1303 sensitive_data.keys = xcalloc(sensitive_data.nkeys, 1304 sizeof(Key)); 1305 for (i = 0; i < sensitive_data.nkeys; i++) 1306 sensitive_data.keys[i] = NULL; 1307 1308 PRIV_START; 1309#if WITH_SSH1 1310 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1, 1311 _PATH_HOST_KEY_FILE, "", NULL, NULL); 1312#endif 1313#ifdef OPENSSL_HAS_ECC 1314 sensitive_data.keys[1] = key_load_private_cert(KEY_ECDSA, 1315 _PATH_HOST_ECDSA_KEY_FILE, "", NULL); 1316#endif 1317 sensitive_data.keys[2] = key_load_private_cert(KEY_ED25519, 1318 _PATH_HOST_ED25519_KEY_FILE, "", NULL); 1319 sensitive_data.keys[3] = key_load_private_cert(KEY_RSA, 1320 _PATH_HOST_RSA_KEY_FILE, "", NULL); 1321 sensitive_data.keys[4] = key_load_private_cert(KEY_DSA, 1322 _PATH_HOST_DSA_KEY_FILE, "", NULL); 1323#ifdef OPENSSL_HAS_ECC 1324 sensitive_data.keys[5] = key_load_private_type(KEY_ECDSA, 1325 _PATH_HOST_ECDSA_KEY_FILE, "", NULL, NULL); 1326#endif 1327 sensitive_data.keys[6] = key_load_private_type(KEY_ED25519, 1328 _PATH_HOST_ED25519_KEY_FILE, "", NULL, NULL); 1329 sensitive_data.keys[7] = key_load_private_type(KEY_RSA, 1330 _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL); 1331 sensitive_data.keys[8] = key_load_private_type(KEY_DSA, 1332 _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL); 1333 PRIV_END; 1334 1335 if (options.hostbased_authentication == 1 && 1336 sensitive_data.keys[0] == NULL && 1337 sensitive_data.keys[5] == NULL && 1338 sensitive_data.keys[6] == NULL && 1339 sensitive_data.keys[7] == NULL && 1340 sensitive_data.keys[8] == NULL) { 1341#ifdef OPENSSL_HAS_ECC 1342 sensitive_data.keys[1] = key_load_cert( 1343 _PATH_HOST_ECDSA_KEY_FILE); 1344#endif 1345 sensitive_data.keys[2] = key_load_cert( 1346 _PATH_HOST_ED25519_KEY_FILE); 1347 sensitive_data.keys[3] = key_load_cert( 1348 _PATH_HOST_RSA_KEY_FILE); 1349 sensitive_data.keys[4] = key_load_cert( 1350 _PATH_HOST_DSA_KEY_FILE); 1351#ifdef OPENSSL_HAS_ECC 1352 sensitive_data.keys[5] = key_load_public( 1353 _PATH_HOST_ECDSA_KEY_FILE, NULL); 1354#endif 1355 sensitive_data.keys[6] = key_load_public( 1356 _PATH_HOST_ED25519_KEY_FILE, NULL); 1357 sensitive_data.keys[7] = key_load_public( 1358 _PATH_HOST_RSA_KEY_FILE, NULL); 1359 sensitive_data.keys[8] = key_load_public( 1360 _PATH_HOST_DSA_KEY_FILE, NULL); 1361 sensitive_data.external_keysign = 1; 1362 } 1363 } 1364 /* 1365 * Get rid of any extra privileges that we may have. We will no 1366 * longer need them. Also, extra privileges could make it very hard 1367 * to read identity files and other non-world-readable files from the 1368 * user's home directory if it happens to be on a NFS volume where 1369 * root is mapped to nobody. 1370 */ 1371 if (original_effective_uid == 0) { 1372 PRIV_START; 1373 permanently_set_uid(pw); 1374 } 1375 1376 /* 1377 * Now that we are back to our own permissions, create ~/.ssh 1378 * directory if it doesn't already exist. 1379 */ 1380 if (config == NULL) { 1381 r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir, 1382 strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR); 1383 if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0) { 1384#ifdef WITH_SELINUX 1385 ssh_selinux_setfscreatecon(buf); 1386#endif 1387 if (mkdir(buf, 0700) < 0) 1388 error("Could not create directory '%.200s'.", 1389 buf); 1390#ifdef WITH_SELINUX 1391 ssh_selinux_setfscreatecon(NULL); 1392#endif 1393 } 1394 } 1395 /* load options.identity_files */ 1396 load_public_identity_files(); 1397 1398 /* optionally set the SSH_AUTHSOCKET_ENV_NAME varibale */ 1399 if (options.identity_agent && 1400 strcmp(options.identity_agent, SSH_AUTHSOCKET_ENV_NAME) != 0) { 1401 if (strcmp(options.identity_agent, "none") == 0) { 1402 unsetenv(SSH_AUTHSOCKET_ENV_NAME); 1403 } else { 1404 p = tilde_expand_filename(options.identity_agent, 1405 original_real_uid); 1406 cp = percent_expand(p, "d", pw->pw_dir, 1407 "u", pw->pw_name, "l", thishost, "h", host, 1408 "r", options.user, (char *)NULL); 1409 setenv(SSH_AUTHSOCKET_ENV_NAME, cp, 1); 1410 free(cp); 1411 free(p); 1412 } 1413 } 1414 1415 /* Expand ~ in known host file names. */ 1416 tilde_expand_paths(options.system_hostfiles, 1417 options.num_system_hostfiles); 1418 tilde_expand_paths(options.user_hostfiles, options.num_user_hostfiles); 1419 1420 signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */ 1421 signal(SIGCHLD, main_sigchld_handler); 1422 1423 /* Log into the remote system. Never returns if the login fails. */ 1424 ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, 1425 options.port, pw, timeout_ms); 1426 1427 if (packet_connection_is_on_socket()) { 1428 verbose("Authenticated to %s ([%s]:%d).", host, 1429 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh)); 1430 } else { 1431 verbose("Authenticated to %s (via proxy).", host); 1432 } 1433 1434 /* We no longer need the private host keys. Clear them now. */ 1435 if (sensitive_data.nkeys != 0) { 1436 for (i = 0; i < sensitive_data.nkeys; i++) { 1437 if (sensitive_data.keys[i] != NULL) { 1438 /* Destroys contents safely */ 1439 debug3("clear hostkey %d", i); 1440 key_free(sensitive_data.keys[i]); 1441 sensitive_data.keys[i] = NULL; 1442 } 1443 } 1444 free(sensitive_data.keys); 1445 } 1446 for (i = 0; i < options.num_identity_files; i++) { 1447 free(options.identity_files[i]); 1448 options.identity_files[i] = NULL; 1449 if (options.identity_keys[i]) { 1450 key_free(options.identity_keys[i]); 1451 options.identity_keys[i] = NULL; 1452 } 1453 } 1454 for (i = 0; i < options.num_certificate_files; i++) { 1455 free(options.certificate_files[i]); 1456 options.certificate_files[i] = NULL; 1457 } 1458 1459 exit_status = compat20 ? ssh_session2() : ssh_session(); 1460 packet_close(); 1461 1462 if (options.control_path != NULL && muxserver_sock != -1) 1463 unlink(options.control_path); 1464 1465 /* Kill ProxyCommand if it is running. */ 1466 ssh_kill_proxy_command(); 1467 1468 return exit_status; 1469} 1470 1471static void 1472control_persist_detach(void) 1473{ 1474 pid_t pid; 1475 int devnull, keep_stderr; 1476 1477 debug("%s: backgrounding master process", __func__); 1478 1479 /* 1480 * master (current process) into the background, and make the 1481 * foreground process a client of the backgrounded master. 1482 */ 1483 switch ((pid = fork())) { 1484 case -1: 1485 fatal("%s: fork: %s", __func__, strerror(errno)); 1486 case 0: 1487 /* Child: master process continues mainloop */ 1488 break; 1489 default: 1490 /* Parent: set up mux slave to connect to backgrounded master */ 1491 debug2("%s: background process is %ld", __func__, (long)pid); 1492 stdin_null_flag = ostdin_null_flag; 1493 options.request_tty = orequest_tty; 1494 tty_flag = otty_flag; 1495 close(muxserver_sock); 1496 muxserver_sock = -1; 1497 options.control_master = SSHCTL_MASTER_NO; 1498 muxclient(options.control_path); 1499 /* muxclient() doesn't return on success. */ 1500 fatal("Failed to connect to new control master"); 1501 } 1502 if ((devnull = open(_PATH_DEVNULL, O_RDWR)) == -1) { 1503 error("%s: open(\"/dev/null\"): %s", __func__, 1504 strerror(errno)); 1505 } else { 1506 keep_stderr = log_is_on_stderr() && debug_flag; 1507 if (dup2(devnull, STDIN_FILENO) == -1 || 1508 dup2(devnull, STDOUT_FILENO) == -1 || 1509 (!keep_stderr && dup2(devnull, STDERR_FILENO) == -1)) 1510 error("%s: dup2: %s", __func__, strerror(errno)); 1511 if (devnull > STDERR_FILENO) 1512 close(devnull); 1513 } 1514 daemon(1, 1); 1515 setproctitle("%s [mux]", options.control_path); 1516} 1517 1518/* Do fork() after authentication. Used by "ssh -f" */ 1519static void 1520fork_postauth(void) 1521{ 1522 if (need_controlpersist_detach) 1523 control_persist_detach(); 1524 debug("forking to background"); 1525 fork_after_authentication_flag = 0; 1526 if (daemon(1, 1) < 0) 1527 fatal("daemon() failed: %.200s", strerror(errno)); 1528} 1529 1530/* Callback for remote forward global requests */ 1531static void 1532ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt) 1533{ 1534 struct Forward *rfwd = (struct Forward *)ctxt; 1535 1536 /* XXX verbose() on failure? */ 1537 debug("remote forward %s for: listen %s%s%d, connect %s:%d", 1538 type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure", 1539 rfwd->listen_path ? rfwd->listen_path : 1540 rfwd->listen_host ? rfwd->listen_host : "", 1541 (rfwd->listen_path || rfwd->listen_host) ? ":" : "", 1542 rfwd->listen_port, rfwd->connect_path ? rfwd->connect_path : 1543 rfwd->connect_host, rfwd->connect_port); 1544 if (rfwd->listen_path == NULL && rfwd->listen_port == 0) { 1545 if (type == SSH2_MSG_REQUEST_SUCCESS) { 1546 rfwd->allocated_port = packet_get_int(); 1547 logit("Allocated port %u for remote forward to %s:%d", 1548 rfwd->allocated_port, 1549 rfwd->connect_host, rfwd->connect_port); 1550 channel_update_permitted_opens(rfwd->handle, 1551 rfwd->allocated_port); 1552 } else { 1553 channel_update_permitted_opens(rfwd->handle, -1); 1554 } 1555 } 1556 1557 if (type == SSH2_MSG_REQUEST_FAILURE) { 1558 if (options.exit_on_forward_failure) { 1559 if (rfwd->listen_path != NULL) 1560 fatal("Error: remote port forwarding failed " 1561 "for listen path %s", rfwd->listen_path); 1562 else 1563 fatal("Error: remote port forwarding failed " 1564 "for listen port %d", rfwd->listen_port); 1565 } else { 1566 if (rfwd->listen_path != NULL) 1567 logit("Warning: remote port forwarding failed " 1568 "for listen path %s", rfwd->listen_path); 1569 else 1570 logit("Warning: remote port forwarding failed " 1571 "for listen port %d", rfwd->listen_port); 1572 } 1573 } 1574 if (++remote_forward_confirms_received == options.num_remote_forwards) { 1575 debug("All remote forwarding requests processed"); 1576 if (fork_after_authentication_flag) 1577 fork_postauth(); 1578 } 1579} 1580 1581static void 1582client_cleanup_stdio_fwd(int id, void *arg) 1583{ 1584 debug("stdio forwarding: done"); 1585 cleanup_exit(0); 1586} 1587 1588static void 1589ssh_stdio_confirm(int id, int success, void *arg) 1590{ 1591 if (!success) 1592 fatal("stdio forwarding failed"); 1593} 1594 1595static void 1596ssh_init_stdio_forwarding(void) 1597{ 1598 Channel *c; 1599 int in, out; 1600 1601 if (options.stdio_forward_host == NULL) 1602 return; 1603 if (!compat20) 1604 fatal("stdio forwarding require Protocol 2"); 1605 1606 debug3("%s: %s:%d", __func__, options.stdio_forward_host, 1607 options.stdio_forward_port); 1608 1609 if ((in = dup(STDIN_FILENO)) < 0 || 1610 (out = dup(STDOUT_FILENO)) < 0) 1611 fatal("channel_connect_stdio_fwd: dup() in/out failed"); 1612 if ((c = channel_connect_stdio_fwd(options.stdio_forward_host, 1613 options.stdio_forward_port, in, out)) == NULL) 1614 fatal("%s: channel_connect_stdio_fwd failed", __func__); 1615 channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0); 1616 channel_register_open_confirm(c->self, ssh_stdio_confirm, NULL); 1617} 1618 1619static void 1620ssh_init_forwarding(void) 1621{ 1622 int success = 0; 1623 int i; 1624 1625 /* Initiate local TCP/IP port forwardings. */ 1626 for (i = 0; i < options.num_local_forwards; i++) { 1627 debug("Local connections to %.200s:%d forwarded to remote " 1628 "address %.200s:%d", 1629 (options.local_forwards[i].listen_path != NULL) ? 1630 options.local_forwards[i].listen_path : 1631 (options.local_forwards[i].listen_host == NULL) ? 1632 (options.fwd_opts.gateway_ports ? "*" : "LOCALHOST") : 1633 options.local_forwards[i].listen_host, 1634 options.local_forwards[i].listen_port, 1635 (options.local_forwards[i].connect_path != NULL) ? 1636 options.local_forwards[i].connect_path : 1637 options.local_forwards[i].connect_host, 1638 options.local_forwards[i].connect_port); 1639 success += channel_setup_local_fwd_listener( 1640 &options.local_forwards[i], &options.fwd_opts); 1641 } 1642 if (i > 0 && success != i && options.exit_on_forward_failure) 1643 fatal("Could not request local forwarding."); 1644 if (i > 0 && success == 0) 1645 error("Could not request local forwarding."); 1646 1647 /* Initiate remote TCP/IP port forwardings. */ 1648 for (i = 0; i < options.num_remote_forwards; i++) { 1649 debug("Remote connections from %.200s:%d forwarded to " 1650 "local address %.200s:%d", 1651 (options.remote_forwards[i].listen_path != NULL) ? 1652 options.remote_forwards[i].listen_path : 1653 (options.remote_forwards[i].listen_host == NULL) ? 1654 "LOCALHOST" : options.remote_forwards[i].listen_host, 1655 options.remote_forwards[i].listen_port, 1656 (options.remote_forwards[i].connect_path != NULL) ? 1657 options.remote_forwards[i].connect_path : 1658 options.remote_forwards[i].connect_host, 1659 options.remote_forwards[i].connect_port); 1660 options.remote_forwards[i].handle = 1661 channel_request_remote_forwarding( 1662 &options.remote_forwards[i]); 1663 if (options.remote_forwards[i].handle < 0) { 1664 if (options.exit_on_forward_failure) 1665 fatal("Could not request remote forwarding."); 1666 else 1667 logit("Warning: Could not request remote " 1668 "forwarding."); 1669 } else { 1670 client_register_global_confirm(ssh_confirm_remote_forward, 1671 &options.remote_forwards[i]); 1672 } 1673 } 1674 1675 /* Initiate tunnel forwarding. */ 1676 if (options.tun_open != SSH_TUNMODE_NO) { 1677 if (client_request_tun_fwd(options.tun_open, 1678 options.tun_local, options.tun_remote) == -1) { 1679 if (options.exit_on_forward_failure) 1680 fatal("Could not request tunnel forwarding."); 1681 else 1682 error("Could not request tunnel forwarding."); 1683 } 1684 } 1685} 1686 1687static void 1688check_agent_present(void) 1689{ 1690 int r; 1691 1692 if (options.forward_agent) { 1693 /* Clear agent forwarding if we don't have an agent. */ 1694 if ((r = ssh_get_authentication_socket(NULL)) != 0) { 1695 options.forward_agent = 0; 1696 if (r != SSH_ERR_AGENT_NOT_PRESENT) 1697 debug("ssh_get_authentication_socket: %s", 1698 ssh_err(r)); 1699 } 1700 } 1701} 1702 1703static int 1704ssh_session(void) 1705{ 1706 int type; 1707 int interactive = 0; 1708 int have_tty = 0; 1709 struct winsize ws; 1710 char *cp; 1711 const char *display; 1712 char *proto = NULL, *data = NULL; 1713 1714 /* Enable compression if requested. */ 1715 if (options.compression) { 1716 debug("Requesting compression at level %d.", 1717 options.compression_level); 1718 1719 if (options.compression_level < 1 || 1720 options.compression_level > 9) 1721 fatal("Compression level must be from 1 (fast) to " 1722 "9 (slow, best)."); 1723 1724 /* Send the request. */ 1725 packet_start(SSH_CMSG_REQUEST_COMPRESSION); 1726 packet_put_int(options.compression_level); 1727 packet_send(); 1728 packet_write_wait(); 1729 type = packet_read(); 1730 if (type == SSH_SMSG_SUCCESS) 1731 packet_start_compression(options.compression_level); 1732 else if (type == SSH_SMSG_FAILURE) 1733 logit("Warning: Remote host refused compression."); 1734 else 1735 packet_disconnect("Protocol error waiting for " 1736 "compression response."); 1737 } 1738 /* Allocate a pseudo tty if appropriate. */ 1739 if (tty_flag) { 1740 debug("Requesting pty."); 1741 1742 /* Start the packet. */ 1743 packet_start(SSH_CMSG_REQUEST_PTY); 1744 1745 /* Store TERM in the packet. There is no limit on the 1746 length of the string. */ 1747 cp = getenv("TERM"); 1748 if (!cp) 1749 cp = ""; 1750 packet_put_cstring(cp); 1751 1752 /* Store window size in the packet. */ 1753 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0) 1754 memset(&ws, 0, sizeof(ws)); 1755 packet_put_int((u_int)ws.ws_row); 1756 packet_put_int((u_int)ws.ws_col); 1757 packet_put_int((u_int)ws.ws_xpixel); 1758 packet_put_int((u_int)ws.ws_ypixel); 1759 1760 /* Store tty modes in the packet. */ 1761 tty_make_modes(fileno(stdin), NULL); 1762 1763 /* Send the packet, and wait for it to leave. */ 1764 packet_send(); 1765 packet_write_wait(); 1766 1767 /* Read response from the server. */ 1768 type = packet_read(); 1769 if (type == SSH_SMSG_SUCCESS) { 1770 interactive = 1; 1771 have_tty = 1; 1772 } else if (type == SSH_SMSG_FAILURE) 1773 logit("Warning: Remote host failed or refused to " 1774 "allocate a pseudo tty."); 1775 else 1776 packet_disconnect("Protocol error waiting for pty " 1777 "request response."); 1778 } 1779 /* Request X11 forwarding if enabled and DISPLAY is set. */ 1780 display = getenv("DISPLAY"); 1781 if (display == NULL && options.forward_x11) 1782 debug("X11 forwarding requested but DISPLAY not set"); 1783 if (options.forward_x11 && client_x11_get_proto(display, 1784 options.xauth_location, options.forward_x11_trusted, 1785 options.forward_x11_timeout, &proto, &data) == 0) { 1786 /* Request forwarding with authentication spoofing. */ 1787 debug("Requesting X11 forwarding with authentication " 1788 "spoofing."); 1789 x11_request_forwarding_with_spoofing(0, display, proto, 1790 data, 0); 1791 /* Read response from the server. */ 1792 type = packet_read(); 1793 if (type == SSH_SMSG_SUCCESS) { 1794 interactive = 1; 1795 } else if (type == SSH_SMSG_FAILURE) { 1796 logit("Warning: Remote host denied X11 forwarding."); 1797 } else { 1798 packet_disconnect("Protocol error waiting for X11 " 1799 "forwarding"); 1800 } 1801 } 1802 /* Tell the packet module whether this is an interactive session. */ 1803 packet_set_interactive(interactive, 1804 options.ip_qos_interactive, options.ip_qos_bulk); 1805 1806 /* Request authentication agent forwarding if appropriate. */ 1807 check_agent_present(); 1808 1809 if (options.forward_agent) { 1810 debug("Requesting authentication agent forwarding."); 1811 auth_request_forwarding(); 1812 1813 /* Read response from the server. */ 1814 type = packet_read(); 1815 packet_check_eom(); 1816 if (type != SSH_SMSG_SUCCESS) 1817 logit("Warning: Remote host denied authentication agent forwarding."); 1818 } 1819 1820 /* Initiate port forwardings. */ 1821 ssh_init_stdio_forwarding(); 1822 ssh_init_forwarding(); 1823 1824 /* Execute a local command */ 1825 if (options.local_command != NULL && 1826 options.permit_local_command) 1827 ssh_local_cmd(options.local_command); 1828 1829 /* 1830 * If requested and we are not interested in replies to remote 1831 * forwarding requests, then let ssh continue in the background. 1832 */ 1833 if (fork_after_authentication_flag) { 1834 if (options.exit_on_forward_failure && 1835 options.num_remote_forwards > 0) { 1836 debug("deferring postauth fork until remote forward " 1837 "confirmation received"); 1838 } else 1839 fork_postauth(); 1840 } 1841 1842 /* 1843 * If a command was specified on the command line, execute the 1844 * command now. Otherwise request the server to start a shell. 1845 */ 1846 if (buffer_len(&command) > 0) { 1847 int len = buffer_len(&command); 1848 if (len > 900) 1849 len = 900; 1850 debug("Sending command: %.*s", len, 1851 (u_char *)buffer_ptr(&command)); 1852 packet_start(SSH_CMSG_EXEC_CMD); 1853 packet_put_string(buffer_ptr(&command), buffer_len(&command)); 1854 packet_send(); 1855 packet_write_wait(); 1856 } else { 1857 debug("Requesting shell."); 1858 packet_start(SSH_CMSG_EXEC_SHELL); 1859 packet_send(); 1860 packet_write_wait(); 1861 } 1862 1863 /* Enter the interactive session. */ 1864 return client_loop(have_tty, tty_flag ? 1865 options.escape_char : SSH_ESCAPECHAR_NONE, 0); 1866} 1867 1868/* request pty/x11/agent/tcpfwd/shell for channel */ 1869static void 1870ssh_session2_setup(int id, int success, void *arg) 1871{ 1872 extern char **environ; 1873 const char *display; 1874 int interactive = tty_flag; 1875 char *proto = NULL, *data = NULL; 1876 1877 if (!success) 1878 return; /* No need for error message, channels code sens one */ 1879 1880 display = getenv("DISPLAY"); 1881 if (display == NULL && options.forward_x11) 1882 debug("X11 forwarding requested but DISPLAY not set"); 1883 if (options.forward_x11 && client_x11_get_proto(display, 1884 options.xauth_location, options.forward_x11_trusted, 1885 options.forward_x11_timeout, &proto, &data) == 0) { 1886 /* Request forwarding with authentication spoofing. */ 1887 debug("Requesting X11 forwarding with authentication " 1888 "spoofing."); 1889 x11_request_forwarding_with_spoofing(id, display, proto, 1890 data, 1); 1891 client_expect_confirm(id, "X11 forwarding", CONFIRM_WARN); 1892 /* XXX exit_on_forward_failure */ 1893 interactive = 1; 1894 } 1895 1896 check_agent_present(); 1897 if (options.forward_agent) { 1898 debug("Requesting authentication agent forwarding."); 1899 channel_request_start(id, "auth-agent-req@openssh.com", 0); 1900 packet_send(); 1901 } 1902 1903 /* Tell the packet module whether this is an interactive session. */ 1904 packet_set_interactive(interactive, 1905 options.ip_qos_interactive, options.ip_qos_bulk); 1906 1907 client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"), 1908 NULL, fileno(stdin), &command, environ); 1909} 1910 1911/* open new channel for a session */ 1912static int 1913ssh_session2_open(void) 1914{ 1915 Channel *c; 1916 int window, packetmax, in, out, err; 1917 1918 if (stdin_null_flag) { 1919 in = open(_PATH_DEVNULL, O_RDONLY); 1920 } else { 1921 in = dup(STDIN_FILENO); 1922 } 1923 out = dup(STDOUT_FILENO); 1924 err = dup(STDERR_FILENO); 1925 1926 if (in < 0 || out < 0 || err < 0) 1927 fatal("dup() in/out/err failed"); 1928 1929 /* enable nonblocking unless tty */ 1930 if (!isatty(in)) 1931 set_nonblock(in); 1932 if (!isatty(out)) 1933 set_nonblock(out); 1934 if (!isatty(err)) 1935 set_nonblock(err); 1936 1937 window = CHAN_SES_WINDOW_DEFAULT; 1938 packetmax = CHAN_SES_PACKET_DEFAULT; 1939 if (tty_flag) { 1940 window >>= 1; 1941 packetmax >>= 1; 1942 } 1943 c = channel_new( 1944 "session", SSH_CHANNEL_OPENING, in, out, err, 1945 window, packetmax, CHAN_EXTENDED_WRITE, 1946 "client-session", /*nonblock*/0); 1947 1948 debug3("ssh_session2_open: channel_new: %d", c->self); 1949 1950 channel_send_open(c->self); 1951 if (!no_shell_flag) 1952 channel_register_open_confirm(c->self, 1953 ssh_session2_setup, NULL); 1954 1955 return c->self; 1956} 1957 1958static int 1959ssh_session2(void) 1960{ 1961 int id = -1; 1962 1963 /* XXX should be pre-session */ 1964 if (!options.control_persist) 1965 ssh_init_stdio_forwarding(); 1966 ssh_init_forwarding(); 1967 1968 /* Start listening for multiplex clients */ 1969 muxserver_listen(); 1970 1971 /* 1972 * If we are in control persist mode and have a working mux listen 1973 * socket, then prepare to background ourselves and have a foreground 1974 * client attach as a control slave. 1975 * NB. we must save copies of the flags that we override for 1976 * the backgrounding, since we defer attachment of the slave until 1977 * after the connection is fully established (in particular, 1978 * async rfwd replies have been received for ExitOnForwardFailure). 1979 */ 1980 if (options.control_persist && muxserver_sock != -1) { 1981 ostdin_null_flag = stdin_null_flag; 1982 ono_shell_flag = no_shell_flag; 1983 orequest_tty = options.request_tty; 1984 otty_flag = tty_flag; 1985 stdin_null_flag = 1; 1986 no_shell_flag = 1; 1987 tty_flag = 0; 1988 if (!fork_after_authentication_flag) 1989 need_controlpersist_detach = 1; 1990 fork_after_authentication_flag = 1; 1991 } 1992 /* 1993 * ControlPersist mux listen socket setup failed, attempt the 1994 * stdio forward setup that we skipped earlier. 1995 */ 1996 if (options.control_persist && muxserver_sock == -1) 1997 ssh_init_stdio_forwarding(); 1998 1999 if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN)) 2000 id = ssh_session2_open(); 2001 else { 2002 packet_set_interactive( 2003 options.control_master == SSHCTL_MASTER_NO, 2004 options.ip_qos_interactive, options.ip_qos_bulk); 2005 } 2006 2007 /* If we don't expect to open a new session, then disallow it */ 2008 if (options.control_master == SSHCTL_MASTER_NO && 2009 (datafellows & SSH_NEW_OPENSSH)) { 2010 debug("Requesting no-more-sessions@openssh.com"); 2011 packet_start(SSH2_MSG_GLOBAL_REQUEST); 2012 packet_put_cstring("no-more-sessions@openssh.com"); 2013 packet_put_char(0); 2014 packet_send(); 2015 } 2016 2017 /* Execute a local command */ 2018 if (options.local_command != NULL && 2019 options.permit_local_command) 2020 ssh_local_cmd(options.local_command); 2021 2022 /* 2023 * If requested and we are not interested in replies to remote 2024 * forwarding requests, then let ssh continue in the background. 2025 */ 2026 if (fork_after_authentication_flag) { 2027 if (options.exit_on_forward_failure && 2028 options.num_remote_forwards > 0) { 2029 debug("deferring postauth fork until remote forward " 2030 "confirmation received"); 2031 } else 2032 fork_postauth(); 2033 } 2034 2035 return client_loop(tty_flag, tty_flag ? 2036 options.escape_char : SSH_ESCAPECHAR_NONE, id); 2037} 2038 2039/* Loads all IdentityFile and CertificateFile keys */ 2040static void 2041load_public_identity_files(void) 2042{ 2043 char *filename, *cp, thishost[NI_MAXHOST]; 2044 char *pwdir = NULL, *pwname = NULL; 2045 Key *public; 2046 struct passwd *pw; 2047 int i; 2048 u_int n_ids, n_certs; 2049 char *identity_files[SSH_MAX_IDENTITY_FILES]; 2050 Key *identity_keys[SSH_MAX_IDENTITY_FILES]; 2051 char *certificate_files[SSH_MAX_CERTIFICATE_FILES]; 2052 struct sshkey *certificates[SSH_MAX_CERTIFICATE_FILES]; 2053#ifdef ENABLE_PKCS11 2054 Key **keys; 2055 int nkeys; 2056#endif /* PKCS11 */ 2057 2058 n_ids = n_certs = 0; 2059 memset(identity_files, 0, sizeof(identity_files)); 2060 memset(identity_keys, 0, sizeof(identity_keys)); 2061 memset(certificate_files, 0, sizeof(certificate_files)); 2062 memset(certificates, 0, sizeof(certificates)); 2063 2064#ifdef ENABLE_PKCS11 2065 if (options.pkcs11_provider != NULL && 2066 options.num_identity_files < SSH_MAX_IDENTITY_FILES && 2067 (pkcs11_init(!options.batch_mode) == 0) && 2068 (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL, 2069 &keys)) > 0) { 2070 for (i = 0; i < nkeys; i++) { 2071 if (n_ids >= SSH_MAX_IDENTITY_FILES) { 2072 key_free(keys[i]); 2073 continue; 2074 } 2075 identity_keys[n_ids] = keys[i]; 2076 identity_files[n_ids] = 2077 xstrdup(options.pkcs11_provider); /* XXX */ 2078 n_ids++; 2079 } 2080 free(keys); 2081 } 2082#endif /* ENABLE_PKCS11 */ 2083 if ((pw = getpwuid(original_real_uid)) == NULL) 2084 fatal("load_public_identity_files: getpwuid failed"); 2085 pwname = xstrdup(pw->pw_name); 2086 pwdir = xstrdup(pw->pw_dir); 2087 if (gethostname(thishost, sizeof(thishost)) == -1) 2088 fatal("load_public_identity_files: gethostname: %s", 2089 strerror(errno)); 2090 for (i = 0; i < options.num_identity_files; i++) { 2091 if (n_ids >= SSH_MAX_IDENTITY_FILES || 2092 strcasecmp(options.identity_files[i], "none") == 0) { 2093 free(options.identity_files[i]); 2094 options.identity_files[i] = NULL; 2095 continue; 2096 } 2097 cp = tilde_expand_filename(options.identity_files[i], 2098 original_real_uid); 2099 filename = percent_expand(cp, "d", pwdir, 2100 "u", pwname, "l", thishost, "h", host, 2101 "r", options.user, (char *)NULL); 2102 free(cp); 2103 public = key_load_public(filename, NULL); 2104 debug("identity file %s type %d", filename, 2105 public ? public->type : -1); 2106 free(options.identity_files[i]); 2107 identity_files[n_ids] = filename; 2108 identity_keys[n_ids] = public; 2109 2110 if (++n_ids >= SSH_MAX_IDENTITY_FILES) 2111 continue; 2112 2113 /* 2114 * If no certificates have been explicitly listed then try 2115 * to add the default certificate variant too. 2116 */ 2117 if (options.num_certificate_files != 0) 2118 continue; 2119 xasprintf(&cp, "%s-cert", filename); 2120 public = key_load_public(cp, NULL); 2121 debug("identity file %s type %d", cp, 2122 public ? public->type : -1); 2123 if (public == NULL) { 2124 free(cp); 2125 continue; 2126 } 2127 if (!key_is_cert(public)) { 2128 debug("%s: key %s type %s is not a certificate", 2129 __func__, cp, key_type(public)); 2130 key_free(public); 2131 free(cp); 2132 continue; 2133 } 2134 identity_keys[n_ids] = public; 2135 identity_files[n_ids] = cp; 2136 n_ids++; 2137 } 2138 2139 if (options.num_certificate_files > SSH_MAX_CERTIFICATE_FILES) 2140 fatal("%s: too many certificates", __func__); 2141 for (i = 0; i < options.num_certificate_files; i++) { 2142 cp = tilde_expand_filename(options.certificate_files[i], 2143 original_real_uid); 2144 filename = percent_expand(cp, "d", pwdir, 2145 "u", pwname, "l", thishost, "h", host, 2146 "r", options.user, (char *)NULL); 2147 free(cp); 2148 2149 public = key_load_public(filename, NULL); 2150 debug("certificate file %s type %d", filename, 2151 public ? public->type : -1); 2152 free(options.certificate_files[i]); 2153 options.certificate_files[i] = NULL; 2154 if (public == NULL) { 2155 free(filename); 2156 continue; 2157 } 2158 if (!key_is_cert(public)) { 2159 debug("%s: key %s type %s is not a certificate", 2160 __func__, filename, key_type(public)); 2161 key_free(public); 2162 free(filename); 2163 continue; 2164 } 2165 certificate_files[n_certs] = filename; 2166 certificates[n_certs] = public; 2167 ++n_certs; 2168 } 2169 2170 options.num_identity_files = n_ids; 2171 memcpy(options.identity_files, identity_files, sizeof(identity_files)); 2172 memcpy(options.identity_keys, identity_keys, sizeof(identity_keys)); 2173 2174 options.num_certificate_files = n_certs; 2175 memcpy(options.certificate_files, 2176 certificate_files, sizeof(certificate_files)); 2177 memcpy(options.certificates, certificates, sizeof(certificates)); 2178 2179 explicit_bzero(pwname, strlen(pwname)); 2180 free(pwname); 2181 explicit_bzero(pwdir, strlen(pwdir)); 2182 free(pwdir); 2183} 2184 2185static void 2186main_sigchld_handler(int sig) 2187{ 2188 int save_errno = errno; 2189 pid_t pid; 2190 int status; 2191 2192 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || 2193 (pid < 0 && errno == EINTR)) 2194 ; 2195 2196 signal(sig, main_sigchld_handler); 2197 errno = save_errno; 2198} 2199