openssh/ssh.c

   1 /* $OpenBSD: ssh.c,v 1.324 2009/02/12 03:00:56 djm Exp $ */
   2 /*
   3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   4  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   5  *                    All rights reserved
   6  * Ssh client program.  This program can be used to log into a remote machine.
   7  * The software supports strong authentication, encryption, and forwarding
   8  * of X11, TCP/IP, and authentication connections.
   9  *
  10  * As far as I am concerned, the code I have written for this software
  11  * can be used freely for any purpose.  Any derived versions of this
  12  * software must be clearly marked as such, and if the derived work is
  13  * incompatible with the protocol description in the RFC file, it must be
  14  * called by a name other than "ssh" or "Secure Shell".
  15  *
  16  * Copyright (c) 1999 Niels Provos.  All rights reserved.
  17  * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl.  All rights reserved.
  18  *
  19  * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
  20  * in Canada (German citizen).
  21  *
  22  * Redistribution and use in source and binary forms, with or without
  23  * modification, are permitted provided that the following conditions
  24  * are met:
  25  * 1. Redistributions of source code must retain the above copyright
  26  *    notice, this list of conditions and the following disclaimer.
  27  * 2. Redistributions in binary form must reproduce the above copyright
  28  *    notice, this list of conditions and the following disclaimer in the
  29  *    documentation and/or other materials provided with the distribution.
  30  *
  31  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  32  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  33  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  34  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  35  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  36  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  37  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  38  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  39  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  40  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  41  */
  42
  43 #include "includes.h"
  44
  45 #include <sys/types.h>
  46 #ifdef HAVE_SYS_STAT_H
  47 # include <sys/stat.h>
  48 #endif
  49 #include <sys/resource.h>
  50 #include <sys/ioctl.h>
  51 #include <sys/socket.h>
  52
  53 #include <ctype.h>
  54 #include <errno.h>
  55 #include <fcntl.h>
  56 #include <netdb.h>
  57 #ifdef HAVE_PATHS_H
  58 #include <paths.h>
  59 #endif
  60 #include <pwd.h>
  61 #include <signal.h>
  62 #include <stdarg.h>
  63 #include <stddef.h>
  64 #include <stdio.h>
  65 #include <stdlib.h>
  66 #include <string.h>
  67 #include <unistd.h>
  68
  69 #include <netinet/in.h>
  70 #include <arpa/inet.h>
  71
  72 #include <openssl/evp.h>
  73 #include <openssl/err.h>
  74 #include "openbsd-compat/openssl-compat.h"
  75 #include "openbsd-compat/sys-queue.h"
  76
  77 #include "xmalloc.h"
  78 #include "ssh.h"
  79 #include "ssh1.h"
  80 #include "ssh2.h"
  81 #include "compat.h"
  82 #include "cipher.h"
  83 #include "packet.h"
  84 #include "buffer.h"
  85 #include "channels.h"
  86 #include "key.h"
  87 #include "authfd.h"
  88 #include "authfile.h"
  89 #include "pathnames.h"
  90 #include "dispatch.h"
  91 #include "clientloop.h"
  92 #include "log.h"
  93 #include "readconf.h"
  94 #include "sshconnect.h"
  95 #include "misc.h"
  96 #include "kex.h"
  97 #include "mac.h"
  98 #include "sshpty.h"
  99 #include "match.h"
 100 #include "msg.h"
 101 #include "uidswap.h"
 102 #include "version.h"
 103
 104 #ifdef SMARTCARD
 105 #include "scard.h"
 106 #endif
 107
 108 extern char *__progname;
 109
 110 /* Flag indicating whether debug mode is on.  May be set on the command line. */
 111 int debug_flag = 0;
 112
 113 /* Flag indicating whether a tty should be allocated */
 114 int tty_flag = 0;
 115 int no_tty_flag = 0;
 116 int force_tty_flag = 0;
 117
 118 /* don't exec a shell */
 119 int no_shell_flag = 0;
 120
 121 /*
 122  * Flag indicating that nothing should be read from stdin.  This can be set
 123  * on the command line.
 124  */
 125 int stdin_null_flag = 0;
 126
 127 /*
 128  * Flag indicating that ssh should fork after authentication.  This is useful
 129  * so that the passphrase can be entered manually, and then ssh goes to the
 130  * background.
 131  */
 132 int fork_after_authentication_flag = 0;
 133
 134 /*
 135  * General data structure for command line options and options configurable
 136  * in configuration files.  See readconf.h.
 137  */
 138 Options options;
 139
 140 /* optional user configfile */
 141 char *config = NULL;
 142
 143 /*
 144  * Name of the host we are connecting to.  This is the name given on the
 145  * command line, or the HostName specified for the user-supplied name in a
 146  * configuration file.
 147  */
 148 char *host;
 149
 150 /* socket address the host resolves to */
 151 struct sockaddr_storage hostaddr;
 152
 153 /* Private host keys. */
 154 Sensitive sensitive_data;
 155
 156 /* Original real UID. */
 157 uid_t original_real_uid;
 158 uid_t original_effective_uid;
 159
 160 /* command to be executed */
 161 Buffer command;
 162
 163 /* Should we execute a command or invoke a subsystem? */
 164 int subsystem_flag = 0;
 165
 166 /* # of replies received for global requests */
 167 static int remote_forward_confirms_received = 0;
 168
 169 /* pid of proxycommand child process */
 170 pid_t proxy_command_pid = 0;
 171
 172 /* mux.c */
 173 extern int muxserver_sock;
 174 extern u_int muxclient_command;
 175
 176 /* Prints a help message to the user.  This function never returns. */
 177
 178 static void
 179 usage(void)
 180 {
 181         fprintf(stderr,
 182 "usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n"
 183 "           [-D [bind_address:]port] [-e escape_char] [-F configfile]\n"
 184 "           [-i identity_file] [-L [bind_address:]port:host:hostport]\n"
 185 "           [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
 186 "           [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
 187 "           [-w local_tun[:remote_tun]] [user@]hostname [command]\n"
 188         );
 189         exit(255);
 190 }
 191
 192 static int ssh_session(void);
 193 static int ssh_session2(void);
 194 static void load_public_identity_files(void);
 195
 196 /* from muxclient.c */
 197 void muxclient(const char *);
 198 void muxserver_listen(void);
 199
 200 /*
 201  * Main program for the ssh client.
 202  */
 203 int
 204 main(int ac, char **av)
 205 {
 206         int i, opt, exit_status, use_syslog;
 207         char *p, *cp, *line, buf[256];
 208         struct stat st;
 209         struct passwd *pw;
 210         int dummy, timeout_ms;
 211         extern int optind, optreset;
 212         extern char *optarg;
 213         struct servent *sp;
 214         Forward fwd;
 215
 216         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 217         sanitise_stdfd();
 218
 219         __progname = ssh_get_progname(av[0]);
 220         init_rng();
 221
 222         /*
 223          * Save the original real uid.  It will be needed later (uid-swapping
 224          * may clobber the real uid).
 225          */
 226         original_real_uid = getuid();
 227         original_effective_uid = geteuid();
 228
 229         /*
 230          * Use uid-swapping to give up root privileges for the duration of
 231          * option processing.  We will re-instantiate the rights when we are
 232          * ready to create the privileged port, and will permanently drop
 233          * them when the port has been created (actually, when the connection
 234          * has been made, as we may need to create the port several times).
 235          */
 236         PRIV_END;
 237
 238 #ifdef HAVE_SETRLIMIT
 239         /* If we are installed setuid root be careful to not drop core. */
 240         if (original_real_uid != original_effective_uid) {
 241                 struct rlimit rlim;
 242                 rlim.rlim_cur = rlim.rlim_max = 0;
 243                 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
 244                         fatal("setrlimit failed: %.100s", strerror(errno));
 245         }
 246 #endif
 247         /* Get user data. */
 248         pw = getpwuid(original_real_uid);
 249         if (!pw) {
 250                 logit("You don't exist, go away!");
 251                 exit(255);
 252         }
 253         /* Take a copy of the returned structure. */
 254         pw = pwcopy(pw);
 255
 256         /*
 257          * Set our umask to something reasonable, as some files are created
 258          * with the default umask.  This will make them world-readable but
 259          * writable only by the owner, which is ok for all files for which we
 260          * don't set the modes explicitly.
 261          */
 262         umask(022);
 263
 264         /*
 265          * Initialize option structure to indicate that no values have been
 266          * set.
 267          */
 268         initialize_options(&options);
 269
 270         /* Parse command-line arguments. */
 271         host = NULL;
 272         use_syslog = 0;
 273
 274  again:
 275         while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
 276             "ACD:F:I:KL:MNO:PR:S:TVw:XYy")) != -1) {
 277                 switch (opt) {
 278                 case '1':
 279                         options.protocol = SSH_PROTO_1;
 280                         break;
 281                 case '2':
 282                         options.protocol = SSH_PROTO_2;
 283                         break;
 284                 case '4':
 285                         options.address_family = AF_INET;
 286                         break;
 287                 case '6':
 288                         options.address_family = AF_INET6;
 289                         break;
 290                 case 'n':
 291                         stdin_null_flag = 1;
 292                         break;
 293                 case 'f':
 294                         fork_after_authentication_flag = 1;
 295                         stdin_null_flag = 1;
 296                         break;
 297                 case 'x':
 298                         options.forward_x11 = 0;
 299                         break;
 300                 case 'X':
 301                         options.forward_x11 = 1;
 302                         break;
 303                 case 'y':
 304                         use_syslog = 1;
 305                         break;
 306                 case 'Y':
 307                         options.forward_x11 = 1;
 308                         options.forward_x11_trusted = 1;
 309                         break;
 310                 case 'g':
 311                         options.gateway_ports = 1;
 312                         break;
 313                 case 'O':
 314                         if (strcmp(optarg, "check") == 0)
 315                                 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
 316                         else if (strcmp(optarg, "exit") == 0)
 317                                 muxclient_command = SSHMUX_COMMAND_TERMINATE;
 318                         else
 319                                 fatal("Invalid multiplex command.");
 320                         break;
 321                 case 'P':       /* deprecated */
 322                         options.use_privileged_port = 0;
 323                         break;
 324                 case 'a':
 325                         options.forward_agent = 0;
 326                         break;
 327                 case 'A':
 328                         options.forward_agent = 1;
 329                         break;
 330                 case 'k':
 331                         options.gss_deleg_creds = 0;
 332                         break;
 333                 case 'K':
 334                         options.gss_authentication = 1;
 335                         options.gss_deleg_creds = 1;
 336                         break;
 337                 case 'i':
 338                         if (stat(optarg, &st) < 0) {
 339                                 fprintf(stderr, "Warning: Identity file %s "
 340                                     "not accessible: %s.\n", optarg,
 341                                     strerror(errno));
 342                                 break;
 343                         }
 344                         if (options.num_identity_files >=
 345                             SSH_MAX_IDENTITY_FILES)
 346                                 fatal("Too many identity files specified "
 347                                     "(max %d)", SSH_MAX_IDENTITY_FILES);
 348                         options.identity_files[options.num_identity_files++] =
 349                             xstrdup(optarg);
 350                         break;
 351                 case 'I':
 352 #ifdef SMARTCARD
 353                         options.smartcard_device = xstrdup(optarg);
 354 #else
 355                         fprintf(stderr, "no support for smartcards.\n");
 356 #endif
 357                         break;
 358                 case 't':
 359                         if (tty_flag)
 360                                 force_tty_flag = 1;
 361                         tty_flag = 1;
 362                         break;
 363                 case 'v':
 364                         if (debug_flag == 0) {
 365                                 debug_flag = 1;
 366                                 options.log_level = SYSLOG_LEVEL_DEBUG1;
 367                         } else {
 368                                 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
 369                                         options.log_level++;
 370                                 break;
 371                         }
 372                         /* FALLTHROUGH */
 373                 case 'V':
 374                         fprintf(stderr, "%s, %s\n",
 375                             SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
 376                         if (opt == 'V')
 377                                 exit(0);
 378                         break;
 379                 case 'w':
 380                         if (options.tun_open == -1)
 381                                 options.tun_open = SSH_TUNMODE_DEFAULT;
 382                         options.tun_local = a2tun(optarg, &options.tun_remote);
 383                         if (options.tun_local == SSH_TUNID_ERR) {
 384                                 fprintf(stderr,
 385                                     "Bad tun device '%s'\n", optarg);
 386                                 exit(255);
 387                         }
 388                         break;
 389                 case 'q':
 390                         options.log_level = SYSLOG_LEVEL_QUIET;
 391                         break;
 392                 case 'e':
 393                         if (optarg[0] == '^' && optarg[2] == 0 &&
 394                             (u_char) optarg[1] >= 64 &&
 395                             (u_char) optarg[1] < 128)
 396                                 options.escape_char = (u_char) optarg[1] & 31;
 397                         else if (strlen(optarg) == 1)
 398                                 options.escape_char = (u_char) optarg[0];
 399                         else if (strcmp(optarg, "none") == 0)
 400                                 options.escape_char = SSH_ESCAPECHAR_NONE;
 401                         else {
 402                                 fprintf(stderr, "Bad escape character '%s'.\n",
 403                                     optarg);
 404                                 exit(255);
 405                         }
 406                         break;
 407                 case 'c':
 408                         if (ciphers_valid(optarg)) {
 409                                 /* SSH2 only */
 410                                 options.ciphers = xstrdup(optarg);
 411                                 options.cipher = SSH_CIPHER_INVALID;
 412                         } else {
 413                                 /* SSH1 only */
 414                                 options.cipher = cipher_number(optarg);
 415                                 if (options.cipher == -1) {
 416                                         fprintf(stderr,
 417                                             "Unknown cipher type '%s'\n",
 418                                             optarg);
 419                                         exit(255);
 420                                 }
 421                                 if (options.cipher == SSH_CIPHER_3DES)
 422                                         options.ciphers = "3des-cbc";
 423                                 else if (options.cipher == SSH_CIPHER_BLOWFISH)
 424                                         options.ciphers = "blowfish-cbc";
 425                                 else
 426                                         options.ciphers = (char *)-1;
 427                         }
 428                         break;
 429                 case 'm':
 430                         if (mac_valid(optarg))
 431                                 options.macs = xstrdup(optarg);
 432                         else {
 433                                 fprintf(stderr, "Unknown mac type '%s'\n",
 434                                     optarg);
 435                                 exit(255);
 436                         }
 437                         break;
 438                 case 'M':
 439                         if (options.control_master == SSHCTL_MASTER_YES)
 440                                 options.control_master = SSHCTL_MASTER_ASK;
 441                         else
 442                                 options.control_master = SSHCTL_MASTER_YES;
 443                         break;
 444                 case 'p':
 445                         options.port = a2port(optarg);
 446                         if (options.port <= 0) {
 447                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 448                                 exit(255);
 449                         }
 450                         break;
 451                 case 'l':
 452                         options.user = optarg;
 453                         break;
 454
 455                 case 'L':
 456                         if (parse_forward(&fwd, optarg, 0, 0))
 457                                 add_local_forward(&options, &fwd);
 458                         else {
 459                                 fprintf(stderr,
 460                                     "Bad local forwarding specification '%s'\n",
 461                                     optarg);
 462                                 exit(255);
 463                         }
 464                         break;
 465
 466                 case 'R':
 467                         if (parse_forward(&fwd, optarg, 0, 1)) {
 468                                 add_remote_forward(&options, &fwd);
 469                         } else {
 470                                 fprintf(stderr,
 471                                     "Bad remote forwarding specification "
 472                                     "'%s'\n", optarg);
 473                                 exit(255);
 474                         }
 475                         break;
 476
 477                 case 'D':
 478                         if (parse_forward(&fwd, optarg, 1, 0)) {
 479                                 add_local_forward(&options, &fwd);
 480                         } else {
 481                                 fprintf(stderr,
 482                                     "Bad dynamic forwarding specification "
 483                                     "'%s'\n", optarg);
 484                                 exit(255);
 485                         }
 486                         break;
 487
 488                 case 'C':
 489                         options.compression = 1;
 490                         break;
 491                 case 'N':
 492                         no_shell_flag = 1;
 493                         no_tty_flag = 1;
 494                         break;
 495                 case 'o':
 496                         dummy = 1;
 497                         line = xstrdup(optarg);
 498                         if (process_config_line(&options, host ? host : "",
 499                             line, "command-line", 0, &dummy) != 0)
 500                                 exit(255);
 501                         xfree(line);
 502                         break;
 503                 case 'T':
 504                         no_tty_flag = 1;
 505                         /* ensure that the user doesn't try to backdoor a */
 506                         /* null cipher switch on an interactive session */
 507                         /* so explicitly disable it no matter what */
 508                         options.none_switch=0;
 509                         break;
 510                 case 's':
 511                         subsystem_flag = 1;
 512                         break;
 513                 case 'S':
 514                         if (options.control_path != NULL)
 515                                 free(options.control_path);
 516                         options.control_path = xstrdup(optarg);
 517                         break;
 518                 case 'b':
 519                         options.bind_address = optarg;
 520                         break;
 521                 case 'F':
 522                         config = optarg;
 523                         break;
 524                 default:
 525                         usage();
 526                 }
 527         }
 528
 529         ac -= optind;
 530         av += optind;
 531
 532         if (ac > 0 && !host && **av != '-') {
 533                 if (strrchr(*av, '@')) {
 534                         p = xstrdup(*av);
 535                         cp = strrchr(p, '@');
 536                         if (cp == NULL || cp == p)
 537                                 usage();
 538                         options.user = p;
 539                         *cp = '\0';
 540                         host = ++cp;
 541                 } else
 542                         host = *av;
 543                 if (ac > 1) {
 544                         optind = optreset = 1;
 545                         goto again;
 546                 }
 547                 ac--, av++;
 548         }
 549
 550         /* Check that we got a host name. */
 551         if (!host)
 552                 usage();
 553
 554         SSLeay_add_all_algorithms();
 555         ERR_load_crypto_strings();
 556
 557         /* Initialize the command to execute on remote host. */
 558         buffer_init(&command);
 559
 560         /*
 561          * Save the command to execute on the remote host in a buffer. There
 562          * is no limit on the length of the command, except by the maximum
 563          * packet size.  Also sets the tty flag if there is no command.
 564          */
 565         if (!ac) {
 566                 /* No command specified - execute shell on a tty. */
 567                 tty_flag = 1;
 568                 if (subsystem_flag) {
 569                         fprintf(stderr,
 570                             "You must specify a subsystem to invoke.\n");
 571                         usage();
 572                 }
 573         } else {
 574                 /* A command has been specified.  Store it into the buffer. */
 575                 for (i = 0; i < ac; i++) {
 576                         if (i)
 577                                 buffer_append(&command, " ", 1);
 578                         buffer_append(&command, av[i], strlen(av[i]));
 579                 }
 580         }
 581
 582         /* Cannot fork to background if no command. */
 583         if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
 584             !no_shell_flag)
 585                 fatal("Cannot fork into background without a command "
 586                     "to execute.");
 587
 588         /* Allocate a tty by default if no command specified. */
 589         if (buffer_len(&command) == 0)
 590                 tty_flag = 1;
 591
 592         /* Force no tty */
 593         if (no_tty_flag)
 594                 tty_flag = 0;
 595         /* Do not allocate a tty if stdin is not a tty. */
 596         if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
 597                 if (tty_flag)
 598                         logit("Pseudo-terminal will not be allocated because "
 599                             "stdin is not a terminal.");
 600                 tty_flag = 0;
 601         }
 602
 603         /*
 604          * Initialize "log" output.  Since we are the client all output
 605          * actually goes to stderr.
 606          */
 607         log_init(av[0],
 608             options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
 609             SYSLOG_FACILITY_USER, !use_syslog);
 610
 611         /*
 612          * Read per-user configuration file.  Ignore the system wide config
 613          * file if the user specifies a config file on the command line.
 614          */
 615         if (config != NULL) {
 616                 if (!read_config_file(config, host, &options, 0))
 617                         fatal("Can't open user config file %.100s: "
 618                             "%.100s", config, strerror(errno));
 619         } else {
 620             /*
 621              * Since the config file parsing code aborts if it sees
 622              * options it doesn't recognize, allow users to put
 623              * options specific to compile-time add-ons in alternate
 624              * config files so their primary config file will
 625              * interoperate SSH versions that don't support those
 626              * options.
 627              */
 628 #ifdef GSSAPI
 629                 snprintf(buf, sizeof buf, "%.100s/%.100s.gssapi", pw->pw_dir,
 630                     _PATH_SSH_USER_CONFFILE);
 631                 (void)read_config_file(buf, host, &options, 1);
 632 #ifdef GSI
 633                 snprintf(buf, sizeof buf, "%.100s/%.100s.gsi", pw->pw_dir,
 634                     _PATH_SSH_USER_CONFFILE);
 635                 (void)read_config_file(buf, host, &options, 1);
 636 #endif
 637 #if defined(KRB5)
 638                 snprintf(buf, sizeof buf, "%.100s/%.100s.krb", pw->pw_dir,
 639                     _PATH_SSH_USER_CONFFILE);
 640                 (void)read_config_file(buf, host, &options, 1);
 641 #endif
 642 #endif
 643                 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
 644                     _PATH_SSH_USER_CONFFILE);
 645                 (void)read_config_file(buf, host, &options, 1);
 646
 647                 /* Read systemwide configuration file after use config. */
 648                 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
 649                     &options, 0);
 650         }
 651
 652         /* Fill configuration defaults. */
 653         fill_default_options(&options);
 654
 655         channel_set_af(options.address_family);
 656
 657         /* reinit */
 658         log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
 659
 660         seed_rng();
 661
 662         if (options.user == NULL) {
 663                 options.user = xstrdup(pw->pw_name);
 664                 options.implicit = 1;
 665         }
 666         else options.implicit = 0;
 667
 668         /* Get default port if port has not been set. */
 669         if (options.port == 0) {
 670                 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
 671                 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
 672         }
 673
 674         if (options.local_command != NULL) {
 675                 char thishost[NI_MAXHOST];
 676
 677                 if (gethostname(thishost, sizeof(thishost)) == -1)
 678                         fatal("gethostname: %s", strerror(errno));
 679                 snprintf(buf, sizeof(buf), "%d", options.port);
 680                 debug3("expanding LocalCommand: %s", options.local_command);
 681                 cp = options.local_command;
 682                 options.local_command = percent_expand(cp, "d", pw->pw_dir,
 683                     "h", options.hostname? options.hostname : host,
 684                     "l", thishost, "n", host, "r", options.user, "p", buf,
 685                     "u", pw->pw_name, (char *)NULL);
 686                 debug3("expanded LocalCommand: %s", options.local_command);
 687                 xfree(cp);
 688         }
 689
 690         if (options.hostname != NULL)
 691                 host = options.hostname;
 692
 693         /* force lowercase for hostkey matching */
 694         if (options.host_key_alias != NULL) {
 695                 for (p = options.host_key_alias; *p; p++)
 696                         if (isupper(*p))
 697                                 *p = (char)tolower(*p);
 698         }
 699
 700         if (options.proxy_command != NULL &&
 701             strcmp(options.proxy_command, "none") == 0) {
 702                 xfree(options.proxy_command);
 703                 options.proxy_command = NULL;
 704         }
 705         if (options.control_path != NULL &&
 706             strcmp(options.control_path, "none") == 0) {
 707                 xfree(options.control_path);
 708                 options.control_path = NULL;
 709         }
 710
 711         if (options.control_path != NULL) {
 712                 char thishost[NI_MAXHOST];
 713
 714                 if (gethostname(thishost, sizeof(thishost)) == -1)
 715                         fatal("gethostname: %s", strerror(errno));
 716                 snprintf(buf, sizeof(buf), "%d", options.port);
 717                 cp = tilde_expand_filename(options.control_path,
 718                     original_real_uid);
 719                 xfree(options.control_path);
 720                 options.control_path = percent_expand(cp, "p", buf, "h", host,
 721                     "r", options.user, "l", thishost, (char *)NULL);
 722                 xfree(cp);
 723         }
 724         if (muxclient_command != 0 && options.control_path == NULL)
 725                 fatal("No ControlPath specified for \"-O\" command");
 726         if (options.control_path != NULL)
 727                 muxclient(options.control_path);
 728
 729         timeout_ms = options.connection_timeout * 1000;
 730
 731         /* Open a connection to the remote host. */
 732         if (ssh_connect(host, &hostaddr, options.port,
 733             options.address_family, options.connection_attempts, &timeout_ms,
 734             options.tcp_keep_alive,
 735 #ifdef HAVE_CYGWIN
 736             options.use_privileged_port,
 737 #else
 738             original_effective_uid == 0 && options.use_privileged_port,
 739 #endif
 740             options.proxy_command) != 0)
 741                 exit(255);
 742
 743         if (timeout_ms > 0)
 744                 debug3("timeout: %d ms remain after connect", timeout_ms);
 745
 746         /*
 747          * If we successfully made the connection, load the host private key
 748          * in case we will need it later for combined rsa-rhosts
 749          * authentication. This must be done before releasing extra
 750          * privileges, because the file is only readable by root.
 751          * If we cannot access the private keys, load the public keys
 752          * instead and try to execute the ssh-keysign helper instead.
 753          */
 754         sensitive_data.nkeys = 0;
 755         sensitive_data.keys = NULL;
 756         sensitive_data.external_keysign = 0;
 757         if (options.rhosts_rsa_authentication ||
 758             options.hostbased_authentication) {
 759                 sensitive_data.nkeys = 3;
 760                 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
 761                     sizeof(Key));
 762
 763                 PRIV_START;
 764                 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
 765                     _PATH_HOST_KEY_FILE, "", NULL, NULL);
 766                 sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
 767                     _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
 768                 sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
 769                     _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
 770                 PRIV_END;
 771
 772                 if (options.hostbased_authentication == 1 &&
 773                     sensitive_data.keys[0] == NULL &&
 774                     sensitive_data.keys[1] == NULL &&
 775                     sensitive_data.keys[2] == NULL) {
 776                         sensitive_data.keys[1] = key_load_public(
 777                             _PATH_HOST_DSA_KEY_FILE, NULL);
 778                         sensitive_data.keys[2] = key_load_public(
 779                             _PATH_HOST_RSA_KEY_FILE, NULL);
 780                         sensitive_data.external_keysign = 1;
 781                 }
 782         }
 783         /*
 784          * Get rid of any extra privileges that we may have.  We will no
 785          * longer need them.  Also, extra privileges could make it very hard
 786          * to read identity files and other non-world-readable files from the
 787          * user's home directory if it happens to be on a NFS volume where
 788          * root is mapped to nobody.
 789          */
 790         if (original_effective_uid == 0) {
 791                 PRIV_START;
 792                 permanently_set_uid(pw);
 793         }
 794
 795         /*
 796          * Now that we are back to our own permissions, create ~/.ssh
 797          * directory if it doesn't already exist.
 798          */
 799         snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir,
 800             strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
 801         if (stat(buf, &st) < 0)
 802                 if (mkdir(buf, 0700) < 0)
 803                         error("Could not create directory '%.200s'.", buf);
 804
 805         /* load options.identity_files */
 806         load_public_identity_files();
 807
 808         /* Expand ~ in known host file names. */
 809         /* XXX mem-leaks: */
 810         options.system_hostfile =
 811             tilde_expand_filename(options.system_hostfile, original_real_uid);
 812         options.user_hostfile =
 813             tilde_expand_filename(options.user_hostfile, original_real_uid);
 814         options.system_hostfile2 =
 815             tilde_expand_filename(options.system_hostfile2, original_real_uid);
 816         options.user_hostfile2 =
 817             tilde_expand_filename(options.user_hostfile2, original_real_uid);
 818
 819         signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
 820
 821         /* Log into the remote system.  Never returns if the login fails. */
 822         ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
 823             pw, timeout_ms);
 824
 825         /* We no longer need the private host keys.  Clear them now. */
 826         if (sensitive_data.nkeys != 0) {
 827                 for (i = 0; i < sensitive_data.nkeys; i++) {
 828                         if (sensitive_data.keys[i] != NULL) {
 829                                 /* Destroys contents safely */
 830                                 debug3("clear hostkey %d", i);
 831                                 key_free(sensitive_data.keys[i]);
 832                                 sensitive_data.keys[i] = NULL;
 833                         }
 834                 }
 835                 xfree(sensitive_data.keys);
 836         }
 837         for (i = 0; i < options.num_identity_files; i++) {
 838                 if (options.identity_files[i]) {
 839                         xfree(options.identity_files[i]);
 840                         options.identity_files[i] = NULL;
 841                 }
 842                 if (options.identity_keys[i]) {
 843                         key_free(options.identity_keys[i]);
 844                         options.identity_keys[i] = NULL;
 845                 }
 846         }
 847
 848         exit_status = compat20 ? ssh_session2() : ssh_session();
 849         packet_close();
 850
 851         if (options.control_path != NULL && muxserver_sock != -1)
 852                 unlink(options.control_path);
 853
 854         /*
 855          * Send SIGHUP to proxy command if used. We don't wait() in
 856          * case it hangs and instead rely on init to reap the child
 857          */
 858         if (proxy_command_pid > 1)
 859                 kill(proxy_command_pid, SIGHUP);
 860
 861         return exit_status;
 862 }
 863
 864 /* Callback for remote forward global requests */
 865 static void
 866 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
 867 {
 868         Forward *rfwd = (Forward *)ctxt;
 869
 870         /* XXX verbose() on failure? */
 871         debug("remote forward %s for: listen %d, connect %s:%d",
 872             type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
 873             rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
 874         if (type == SSH2_MSG_REQUEST_SUCCESS && rfwd->listen_port == 0) {
 875                 logit("Allocated port %u for remote forward to %s:%d",
 876                         packet_get_int(),
 877                         rfwd->connect_host, rfwd->connect_port);
 878         }
 879
 880         if (type == SSH2_MSG_REQUEST_FAILURE) {
 881                 if (options.exit_on_forward_failure)
 882                         fatal("Error: remote port forwarding failed for "
 883                             "listen port %d", rfwd->listen_port);
 884                 else
 885                         logit("Warning: remote port forwarding failed for "
 886                             "listen port %d", rfwd->listen_port);
 887         }
 888         if (++remote_forward_confirms_received == options.num_remote_forwards) {
 889                 debug("All remote forwarding requests processed");
 890                 if (fork_after_authentication_flag) {
 891                         fork_after_authentication_flag = 0;
 892                         if (daemon(1, 1) < 0)
 893                                 fatal("daemon() failed: %.200s",
 894                                     strerror(errno));
 895                 }
 896         }
 897 }
 898
 899 static void
 900 ssh_init_forwarding(void)
 901 {
 902         int success = 0;
 903         int i;
 904
 905         /* Initiate local TCP/IP port forwardings. */
 906         for (i = 0; i < options.num_local_forwards; i++) {
 907                 debug("Local connections to %.200s:%d forwarded to remote "
 908                     "address %.200s:%d",
 909                     (options.local_forwards[i].listen_host == NULL) ?
 910                     (options.gateway_ports ? "*" : "LOCALHOST") :
 911                     options.local_forwards[i].listen_host,
 912                     options.local_forwards[i].listen_port,
 913                     options.local_forwards[i].connect_host,
 914                     options.local_forwards[i].connect_port);
 915                 success += channel_setup_local_fwd_listener(
 916                     options.local_forwards[i].listen_host,
 917                     options.local_forwards[i].listen_port,
 918                     options.local_forwards[i].connect_host,
 919                     options.local_forwards[i].connect_port,
 920                     options.gateway_ports);
 921         }
 922         if (i > 0 && success != i && options.exit_on_forward_failure)
 923                 fatal("Could not request local forwarding.");
 924         if (i > 0 && success == 0)
 925                 error("Could not request local forwarding.");
 926
 927         /* Initiate remote TCP/IP port forwardings. */
 928         for (i = 0; i < options.num_remote_forwards; i++) {
 929                 debug("Remote connections from %.200s:%d forwarded to "
 930                     "local address %.200s:%d",
 931                     (options.remote_forwards[i].listen_host == NULL) ?
 932                     "LOCALHOST" : options.remote_forwards[i].listen_host,
 933                     options.remote_forwards[i].listen_port,
 934                     options.remote_forwards[i].connect_host,
 935                     options.remote_forwards[i].connect_port);
 936                 if (channel_request_remote_forwarding(
 937                     options.remote_forwards[i].listen_host,
 938                     options.remote_forwards[i].listen_port,
 939                     options.remote_forwards[i].connect_host,
 940                     options.remote_forwards[i].connect_port) < 0) {
 941                         if (options.exit_on_forward_failure)
 942                                 fatal("Could not request remote forwarding.");
 943                         else
 944                                 logit("Warning: Could not request remote "
 945                                     "forwarding.");
 946                 }
 947                 client_register_global_confirm(ssh_confirm_remote_forward,
 948                     &options.remote_forwards[i]);
 949         }
 950
 951         /* Initiate tunnel forwarding. */
 952         if (options.tun_open != SSH_TUNMODE_NO) {
 953                 if (client_request_tun_fwd(options.tun_open,
 954                     options.tun_local, options.tun_remote) == -1) {
 955                         if (options.exit_on_forward_failure)
 956                                 fatal("Could not request tunnel forwarding.");
 957                         else
 958                                 error("Could not request tunnel forwarding.");
 959                 }
 960         }
 961 }
 962
 963 static void
 964 check_agent_present(void)
 965 {
 966         if (options.forward_agent) {
 967                 /* Clear agent forwarding if we don't have an agent. */
 968                 if (!ssh_agent_present())
 969                         options.forward_agent = 0;
 970         }
 971 }
 972
 973 static int
 974 ssh_session(void)
 975 {
 976         int type;
 977         int interactive = 0;
 978         int have_tty = 0;
 979         struct winsize ws;
 980         char *cp;
 981         const char *display;
 982
 983         /* Enable compression if requested. */
 984         if (options.compression) {
 985                 debug("Requesting compression at level %d.",
 986                     options.compression_level);
 987
 988                 if (options.compression_level < 1 ||
 989                     options.compression_level > 9)
 990                         fatal("Compression level must be from 1 (fast) to "
 991                             "9 (slow, best).");
 992
 993                 /* Send the request. */
 994                 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
 995                 packet_put_int(options.compression_level);
 996                 packet_send();
 997                 packet_write_wait();
 998                 type = packet_read();
 999                 if (type == SSH_SMSG_SUCCESS)
1000                         packet_start_compression(options.compression_level);
1001                 else if (type == SSH_SMSG_FAILURE)
1002                         logit("Warning: Remote host refused compression.");
1003                 else
1004                         packet_disconnect("Protocol error waiting for "
1005                             "compression response.");
1006         }
1007         /* Allocate a pseudo tty if appropriate. */
1008         if (tty_flag) {
1009                 debug("Requesting pty.");
1010
1011                 /* Start the packet. */
1012                 packet_start(SSH_CMSG_REQUEST_PTY);
1013
1014                 /* Store TERM in the packet.  There is no limit on the
1015                    length of the string. */
1016                 cp = getenv("TERM");
1017                 if (!cp)
1018                         cp = "";
1019                 packet_put_cstring(cp);
1020
1021                 /* Store window size in the packet. */
1022                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
1023                         memset(&ws, 0, sizeof(ws));
1024                 packet_put_int((u_int)ws.ws_row);
1025                 packet_put_int((u_int)ws.ws_col);
1026                 packet_put_int((u_int)ws.ws_xpixel);
1027                 packet_put_int((u_int)ws.ws_ypixel);
1028
1029                 /* Store tty modes in the packet. */
1030                 tty_make_modes(fileno(stdin), NULL);
1031
1032                 /* Send the packet, and wait for it to leave. */
1033                 packet_send();
1034                 packet_write_wait();
1035
1036                 /* Read response from the server. */
1037                 type = packet_read();
1038                 if (type == SSH_SMSG_SUCCESS) {
1039                         interactive = 1;
1040                         have_tty = 1;
1041                 } else if (type == SSH_SMSG_FAILURE)
1042                         logit("Warning: Remote host failed or refused to "
1043                             "allocate a pseudo tty.");
1044                 else
1045                         packet_disconnect("Protocol error waiting for pty "
1046                             "request response.");
1047         }
1048         /* Request X11 forwarding if enabled and DISPLAY is set. */
1049         display = getenv("DISPLAY");
1050         if (options.forward_x11 && display != NULL) {
1051                 char *proto, *data;
1052                 /* Get reasonable local authentication information. */
1053                 client_x11_get_proto(display, options.xauth_location,
1054                     options.forward_x11_trusted, &proto, &data);
1055                 /* Request forwarding with authentication spoofing. */
1056                 debug("Requesting X11 forwarding with authentication "
1057                     "spoofing.");
1058                 x11_request_forwarding_with_spoofing(0, display, proto, data);
1059
1060                 /* Read response from the server. */
1061                 type = packet_read();
1062                 if (type == SSH_SMSG_SUCCESS) {
1063                         interactive = 1;
1064                 } else if (type == SSH_SMSG_FAILURE) {
1065                         logit("Warning: Remote host denied X11 forwarding.");
1066                 } else {
1067                         packet_disconnect("Protocol error waiting for X11 "
1068                             "forwarding");
1069                 }
1070         }
1071         /* Tell the packet module whether this is an interactive session. */
1072         packet_set_interactive(interactive);
1073
1074         /* Request authentication agent forwarding if appropriate. */
1075         check_agent_present();
1076
1077         if (options.forward_agent) {
1078                 debug("Requesting authentication agent forwarding.");
1079                 auth_request_forwarding();
1080
1081                 /* Read response from the server. */
1082                 type = packet_read();
1083                 packet_check_eom();
1084                 if (type != SSH_SMSG_SUCCESS)
1085                         logit("Warning: Remote host denied authentication agent forwarding.");
1086         }
1087
1088         /* Initiate port forwardings. */
1089         ssh_init_forwarding();
1090
1091         /* Execute a local command */
1092         if (options.local_command != NULL &&
1093             options.permit_local_command)
1094                 ssh_local_cmd(options.local_command);
1095
1096         /*
1097          * If requested and we are not interested in replies to remote
1098          * forwarding requests, then let ssh continue in the background.
1099          */
1100         if (fork_after_authentication_flag &&
1101             (!options.exit_on_forward_failure ||
1102             options.num_remote_forwards == 0)) {
1103                 fork_after_authentication_flag = 0;
1104                 if (daemon(1, 1) < 0)
1105                         fatal("daemon() failed: %.200s", strerror(errno));
1106         }
1107
1108         /*
1109          * If a command was specified on the command line, execute the
1110          * command now. Otherwise request the server to start a shell.
1111          */
1112         if (buffer_len(&command) > 0) {
1113                 int len = buffer_len(&command);
1114                 if (len > 900)
1115                         len = 900;
1116                 debug("Sending command: %.*s", len,
1117                     (u_char *)buffer_ptr(&command));
1118                 packet_start(SSH_CMSG_EXEC_CMD);
1119                 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1120                 packet_send();
1121                 packet_write_wait();
1122         } else {
1123                 debug("Requesting shell.");
1124                 packet_start(SSH_CMSG_EXEC_SHELL);
1125                 packet_send();
1126                 packet_write_wait();
1127         }
1128
1129         /* Enter the interactive session. */
1130         return client_loop(have_tty, tty_flag ?
1131             options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1132 }
1133
1134 /* request pty/x11/agent/tcpfwd/shell for channel */
1135 static void
1136 ssh_session2_setup(int id, void *arg)
1137 {
1138         extern char **environ;
1139         const char *display;
1140         int interactive = tty_flag;
1141
1142         display = getenv("DISPLAY");
1143         if (options.forward_x11 && display != NULL) {
1144                 char *proto, *data;
1145                 /* Get reasonable local authentication information. */
1146                 client_x11_get_proto(display, options.xauth_location,
1147                     options.forward_x11_trusted, &proto, &data);
1148                 /* Request forwarding with authentication spoofing. */
1149                 debug("Requesting X11 forwarding with authentication "
1150                     "spoofing.");
1151                 x11_request_forwarding_with_spoofing(id, display, proto, data);
1152                 interactive = 1;
1153                 /* XXX wait for reply */
1154         }
1155
1156         check_agent_present();
1157         if (options.forward_agent) {
1158                 debug("Requesting authentication agent forwarding.");
1159                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1160                 packet_send();
1161         }
1162
1163         client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1164             NULL, fileno(stdin), &command, environ);
1165
1166         packet_set_interactive(interactive);
1167 }
1168
1169 /* open new channel for a session */
1170 static int
1171 ssh_session2_open(void)
1172 {
1173         Channel *c;
1174         int window, packetmax, in, out, err;
1175         int sock;
1176         int socksize;
1177         int socksizelen = sizeof(int);
1178
1179         if (stdin_null_flag) {
1180                 in = open(_PATH_DEVNULL, O_RDONLY);
1181         } else {
1182                 in = dup(STDIN_FILENO);
1183         }
1184         out = dup(STDOUT_FILENO);
1185         err = dup(STDERR_FILENO);
1186
1187         if (in < 0 || out < 0 || err < 0)
1188                 fatal("dup() in/out/err failed");
1189
1190         /* enable nonblocking unless tty */
1191         if (!isatty(in))
1192                 set_nonblock(in);
1193         if (!isatty(out))
1194                 set_nonblock(out);
1195         if (!isatty(err))
1196                 set_nonblock(err);
1197
1198         /* we need to check to see if what they want to do about buffer */
1199         /* sizes here. In a hpn to nonhpn connection we want to limit */
1200         /* the window size to something reasonable in case the far side */
1201         /* has the large window bug. In hpn to hpn connection we want to */
1202         /* use the max window size but allow the user to override it */
1203         /* lastly if they disabled hpn then use the ssh std window size */
1204
1205         /* so why don't we just do a getsockopt() here and set the */
1206         /* ssh window to that? In the case of a autotuning receive */
1207         /* window the window would get stuck at the initial buffer */
1208         /* size generally less than 96k. Therefore we need to set the */
1209         /* maximum ssh window size to the maximum hpn buffer size */
1210         /* unless the user has specifically set the tcprcvbufpoll */
1211         /* to no. In which case we *can* just set the window to the */
1212         /* minimum of the hpn buffer size and tcp receive buffer size */
1213
1214         if (tty_flag)
1215                 options.hpn_buffer_size = CHAN_SES_WINDOW_DEFAULT;
1216         else
1217                 options.hpn_buffer_size = 2*1024*1024;
1218
1219         if (datafellows & SSH_BUG_LARGEWINDOW)
1220         {
1221                 debug("HPN to Non-HPN Connection");
1222         }
1223         else
1224         {
1225                 if (options.tcp_rcv_buf_poll <= 0)
1226                 {
1227                         sock = socket(AF_INET, SOCK_STREAM, 0);
1228                         getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1229                                    &socksize, &socksizelen);
1230                         close(sock);
1231                         debug("socksize %d", socksize);
1232                         options.hpn_buffer_size = socksize;
1233                         debug ("HPNBufferSize set to TCP RWIN: %d", options.hpn_buffer_size);
1234                 }
1235                 else
1236                 {
1237                         if (options.tcp_rcv_buf > 0)
1238                         {
1239                                 /*create a socket but don't connect it */
1240                                 /* we use that the get the rcv socket size */
1241                                 sock = socket(AF_INET, SOCK_STREAM, 0);
1242                                 /* if they are using the tcp_rcv_buf option */
1243                                 /* attempt to set the buffer size to that */
1244                                 if (options.tcp_rcv_buf)
1245                                         setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void *)&options.tcp_rcv_buf,
1246                                                    sizeof(options.tcp_rcv_buf));
1247                                 getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1248                                            &socksize, &socksizelen);
1249                                 close(sock);
1250                                 debug("socksize %d", socksize);
1251                                 options.hpn_buffer_size = socksize;
1252                                 debug ("HPNBufferSize set to user TCPRcvBuf: %d", options.hpn_buffer_size);
1253                         }
1254                 }
1255
1256         }
1257
1258         debug("Final hpn_buffer_size = %d", options.hpn_buffer_size);
1259
1260         window = options.hpn_buffer_size;
1261
1262         channel_set_hpn(options.hpn_disabled, options.hpn_buffer_size);
1263
1264         packetmax = CHAN_SES_PACKET_DEFAULT;
1265         if (tty_flag) {
1266                 window = 4*CHAN_SES_PACKET_DEFAULT;
1267                 window >>= 1;
1268                 packetmax >>= 1;
1269         }
1270         c = channel_new(
1271             "session", SSH_CHANNEL_OPENING, in, out, err,
1272             window, packetmax, CHAN_EXTENDED_WRITE,
1273             "client-session", /*nonblock*/0);
1274         if ((options.tcp_rcv_buf_poll > 0) && (!options.hpn_disabled)) {
1275                 c->dynamic_window = 1;
1276                 debug ("Enabled Dynamic Window Scaling\n");
1277         }
1278         debug3("ssh_session2_open: channel_new: %d", c->self);
1279
1280         channel_send_open(c->self);
1281         if (!no_shell_flag)
1282                 channel_register_open_confirm(c->self,
1283                     ssh_session2_setup, NULL);
1284
1285         return c->self;
1286 }
1287
1288 static int
1289 ssh_session2(void)
1290 {
1291         int id = -1;
1292
1293         /* XXX should be pre-session */
1294         ssh_init_forwarding();
1295
1296         if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1297                 id = ssh_session2_open();
1298
1299         /* If we don't expect to open a new session, then disallow it */
1300         if (options.control_master == SSHCTL_MASTER_NO &&
1301             (datafellows & SSH_NEW_OPENSSH)) {
1302                 debug("Requesting no-more-sessions@openssh.com");
1303                 packet_start(SSH2_MSG_GLOBAL_REQUEST);
1304                 packet_put_cstring("no-more-sessions@openssh.com");
1305                 packet_put_char(0);
1306                 packet_send();
1307         }
1308
1309         /* Execute a local command */
1310         if (options.local_command != NULL &&
1311             options.permit_local_command)
1312                 ssh_local_cmd(options.local_command);
1313
1314         /* Start listening for multiplex clients */
1315         muxserver_listen();
1316
1317         /* If requested, let ssh continue in the background. */
1318         if (fork_after_authentication_flag) {
1319                 fork_after_authentication_flag = 0;
1320                 if (daemon(1, 1) < 0)
1321                         fatal("daemon() failed: %.200s", strerror(errno));
1322         }
1323
1324         return client_loop(tty_flag, tty_flag ?
1325             options.escape_char : SSH_ESCAPECHAR_NONE, id);
1326 }
1327
1328 static void
1329 load_public_identity_files(void)
1330 {
1331         char *filename, *cp, thishost[NI_MAXHOST];
1332         char *pwdir = NULL, *pwname = NULL;
1333         int i = 0;
1334         Key *public;
1335         struct passwd *pw;
1336 #ifdef SMARTCARD
1337         Key **keys;
1338
1339         if (options.smartcard_device != NULL &&
1340             options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1341             (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL) {
1342                 int count = 0;
1343                 for (i = 0; keys[i] != NULL; i++) {
1344                         count++;
1345                         memmove(&options.identity_files[1],
1346                             &options.identity_files[0],
1347                             sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1));
1348                         memmove(&options.identity_keys[1],
1349                             &options.identity_keys[0],
1350                             sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1));
1351                         options.num_identity_files++;
1352                         options.identity_keys[0] = keys[i];
1353                         options.identity_files[0] = sc_get_key_label(keys[i]);
1354                 }
1355                 if (options.num_identity_files > SSH_MAX_IDENTITY_FILES)
1356                         options.num_identity_files = SSH_MAX_IDENTITY_FILES;
1357                 i = count;
1358                 xfree(keys);
1359         }
1360 #endif /* SMARTCARD */
1361         if ((pw = getpwuid(original_real_uid)) == NULL)
1362                 fatal("load_public_identity_files: getpwuid failed");
1363         pwname = xstrdup(pw->pw_name);
1364         pwdir = xstrdup(pw->pw_dir);
1365         if (gethostname(thishost, sizeof(thishost)) == -1)
1366                 fatal("load_public_identity_files: gethostname: %s",
1367                     strerror(errno));
1368         for (; i < options.num_identity_files; i++) {
1369                 cp = tilde_expand_filename(options.identity_files[i],
1370                     original_real_uid);
1371                 filename = percent_expand(cp, "d", pwdir,
1372                     "u", pwname, "l", thishost, "h", host,
1373                     "r", options.user, (char *)NULL);
1374                 xfree(cp);
1375                 public = key_load_public(filename, NULL);
1376                 debug("identity file %s type %d", filename,
1377                     public ? public->type : -1);
1378                 xfree(options.identity_files[i]);
1379                 options.identity_files[i] = filename;
1380                 options.identity_keys[i] = public;
1381         }
1382         bzero(pwname, strlen(pwname));
1383         xfree(pwname);
1384         bzero(pwdir, strlen(pwdir));
1385         xfree(pwdir);
1386 }