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_pathnames();
 221         init_rng();
 222
 223         /*
 224          * Save the original real uid.  It will be needed later (uid-swapping
 225          * may clobber the real uid).
 226          */
 227         original_real_uid = getuid();
 228         original_effective_uid = geteuid();
 229
 230         /*
 231          * Use uid-swapping to give up root privileges for the duration of
 232          * option processing.  We will re-instantiate the rights when we are
 233          * ready to create the privileged port, and will permanently drop
 234          * them when the port has been created (actually, when the connection
 235          * has been made, as we may need to create the port several times).
 236          */
 237         PRIV_END;
 238
 239 #ifdef HAVE_SETRLIMIT
 240         /* If we are installed setuid root be careful to not drop core. */
 241         if (original_real_uid != original_effective_uid) {
 242                 struct rlimit rlim;
 243                 rlim.rlim_cur = rlim.rlim_max = 0;
 244                 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
 245                         fatal("setrlimit failed: %.100s", strerror(errno));
 246         }
 247 #endif
 248         /* Get user data. */
 249         pw = getpwuid(original_real_uid);
 250         if (!pw) {
 251                 logit("You don't exist, go away!");
 252                 exit(255);
 253         }
 254         /* Take a copy of the returned structure. */
 255         pw = pwcopy(pw);
 256
 257         /*
 258          * Set our umask to something reasonable, as some files are created
 259          * with the default umask.  This will make them world-readable but
 260          * writable only by the owner, which is ok for all files for which we
 261          * don't set the modes explicitly.
 262          */
 263         umask(022);
 264
 265         /*
 266          * Initialize option structure to indicate that no values have been
 267          * set.
 268          */
 269         initialize_options(&options);
 270
 271         /* Parse command-line arguments. */
 272         host = NULL;
 273         use_syslog = 0;
 274
 275  again:
 276         while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
 277             "ACD:F:I:KL:MNO:PR:S:TVw:XYy")) != -1) {
 278                 switch (opt) {
 279                 case '1':
 280                         options.protocol = SSH_PROTO_1;
 281                         break;
 282                 case '2':
 283                         options.protocol = SSH_PROTO_2;
 284                         break;
 285                 case '4':
 286                         options.address_family = AF_INET;
 287                         break;
 288                 case '6':
 289                         options.address_family = AF_INET6;
 290                         break;
 291                 case 'n':
 292                         stdin_null_flag = 1;
 293                         break;
 294                 case 'f':
 295                         fork_after_authentication_flag = 1;
 296                         stdin_null_flag = 1;
 297                         break;
 298                 case 'x':
 299                         options.forward_x11 = 0;
 300                         break;
 301                 case 'X':
 302                         options.forward_x11 = 1;
 303                         break;
 304                 case 'y':
 305                         use_syslog = 1;
 306                         break;
 307                 case 'Y':
 308                         options.forward_x11 = 1;
 309                         options.forward_x11_trusted = 1;
 310                         break;
 311                 case 'g':
 312                         options.gateway_ports = 1;
 313                         break;
 314                 case 'O':
 315                         if (strcmp(optarg, "check") == 0)
 316                                 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
 317                         else if (strcmp(optarg, "exit") == 0)
 318                                 muxclient_command = SSHMUX_COMMAND_TERMINATE;
 319                         else
 320                                 fatal("Invalid multiplex command.");
 321                         break;
 322                 case 'P':       /* deprecated */
 323                         options.use_privileged_port = 0;
 324                         break;
 325                 case 'a':
 326                         options.forward_agent = 0;
 327                         break;
 328                 case 'A':
 329                         options.forward_agent = 1;
 330                         break;
 331                 case 'k':
 332                         options.gss_deleg_creds = 0;
 333                         break;
 334                 case 'K':
 335                         options.gss_authentication = 1;
 336                         options.gss_deleg_creds = 1;
 337                         break;
 338                 case 'i':
 339                         if (stat(optarg, &st) < 0) {
 340                                 fprintf(stderr, "Warning: Identity file %s "
 341                                     "not accessible: %s.\n", optarg,
 342                                     strerror(errno));
 343                                 break;
 344                         }
 345                         if (options.num_identity_files >=
 346                             SSH_MAX_IDENTITY_FILES)
 347                                 fatal("Too many identity files specified "
 348                                     "(max %d)", SSH_MAX_IDENTITY_FILES);
 349                         options.identity_files[options.num_identity_files++] =
 350                             xstrdup(optarg);
 351                         break;
 352                 case 'I':
 353 #ifdef SMARTCARD
 354                         options.smartcard_device = xstrdup(optarg);
 355 #else
 356                         fprintf(stderr, "no support for smartcards.\n");
 357 #endif
 358                         break;
 359                 case 't':
 360                         if (tty_flag)
 361                                 force_tty_flag = 1;
 362                         tty_flag = 1;
 363                         break;
 364                 case 'v':
 365                         if (debug_flag == 0) {
 366                                 debug_flag = 1;
 367                                 options.log_level = SYSLOG_LEVEL_DEBUG1;
 368                         } else {
 369                                 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
 370                                         options.log_level++;
 371                                 break;
 372                         }
 373                         /* FALLTHROUGH */
 374                 case 'V':
 375                         fprintf(stderr, "%s, %s\n",
 376                             SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
 377                         if (opt == 'V')
 378                                 exit(0);
 379                         break;
 380                 case 'w':
 381                         if (options.tun_open == -1)
 382                                 options.tun_open = SSH_TUNMODE_DEFAULT;
 383                         options.tun_local = a2tun(optarg, &options.tun_remote);
 384                         if (options.tun_local == SSH_TUNID_ERR) {
 385                                 fprintf(stderr,
 386                                     "Bad tun device '%s'\n", optarg);
 387                                 exit(255);
 388                         }
 389                         break;
 390                 case 'q':
 391                         options.log_level = SYSLOG_LEVEL_QUIET;
 392                         break;
 393                 case 'e':
 394                         if (optarg[0] == '^' && optarg[2] == 0 &&
 395                             (u_char) optarg[1] >= 64 &&
 396                             (u_char) optarg[1] < 128)
 397                                 options.escape_char = (u_char) optarg[1] & 31;
 398                         else if (strlen(optarg) == 1)
 399                                 options.escape_char = (u_char) optarg[0];
 400                         else if (strcmp(optarg, "none") == 0)
 401                                 options.escape_char = SSH_ESCAPECHAR_NONE;
 402                         else {
 403                                 fprintf(stderr, "Bad escape character '%s'.\n",
 404                                     optarg);
 405                                 exit(255);
 406                         }
 407                         break;
 408                 case 'c':
 409                         if (ciphers_valid(optarg)) {
 410                                 /* SSH2 only */
 411                                 options.ciphers = xstrdup(optarg);
 412                                 options.cipher = SSH_CIPHER_INVALID;
 413                         } else {
 414                                 /* SSH1 only */
 415                                 options.cipher = cipher_number(optarg);
 416                                 if (options.cipher == -1) {
 417                                         fprintf(stderr,
 418                                             "Unknown cipher type '%s'\n",
 419                                             optarg);
 420                                         exit(255);
 421                                 }
 422                                 if (options.cipher == SSH_CIPHER_3DES)
 423                                         options.ciphers = "3des-cbc";
 424                                 else if (options.cipher == SSH_CIPHER_BLOWFISH)
 425                                         options.ciphers = "blowfish-cbc";
 426                                 else
 427                                         options.ciphers = (char *)-1;
 428                         }
 429                         break;
 430                 case 'm':
 431                         if (mac_valid(optarg))
 432                                 options.macs = xstrdup(optarg);
 433                         else {
 434                                 fprintf(stderr, "Unknown mac type '%s'\n",
 435                                     optarg);
 436                                 exit(255);
 437                         }
 438                         break;
 439                 case 'M':
 440                         if (options.control_master == SSHCTL_MASTER_YES)
 441                                 options.control_master = SSHCTL_MASTER_ASK;
 442                         else
 443                                 options.control_master = SSHCTL_MASTER_YES;
 444                         break;
 445                 case 'p':
 446                         options.port = a2port(optarg);
 447                         if (options.port <= 0) {
 448                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 449                                 exit(255);
 450                         }
 451                         break;
 452                 case 'l':
 453                         options.user = optarg;
 454                         break;
 455
 456                 case 'L':
 457                         if (parse_forward(&fwd, optarg, 0, 0))
 458                                 add_local_forward(&options, &fwd);
 459                         else {
 460                                 fprintf(stderr,
 461                                     "Bad local forwarding specification '%s'\n",
 462                                     optarg);
 463                                 exit(255);
 464                         }
 465                         break;
 466
 467                 case 'R':
 468                         if (parse_forward(&fwd, optarg, 0, 1)) {
 469                                 add_remote_forward(&options, &fwd);
 470                         } else {
 471                                 fprintf(stderr,
 472                                     "Bad remote forwarding specification "
 473                                     "'%s'\n", optarg);
 474                                 exit(255);
 475                         }
 476                         break;
 477
 478                 case 'D':
 479                         if (parse_forward(&fwd, optarg, 1, 0)) {
 480                                 add_local_forward(&options, &fwd);
 481                         } else {
 482                                 fprintf(stderr,
 483                                     "Bad dynamic forwarding specification "
 484                                     "'%s'\n", optarg);
 485                                 exit(255);
 486                         }
 487                         break;
 488
 489                 case 'C':
 490                         options.compression = 1;
 491                         break;
 492                 case 'N':
 493                         no_shell_flag = 1;
 494                         no_tty_flag = 1;
 495                         break;
 496                 case 'o':
 497                         dummy = 1;
 498                         line = xstrdup(optarg);
 499                         if (process_config_line(&options, host ? host : "",
 500                             line, "command-line", 0, &dummy) != 0)
 501                                 exit(255);
 502                         xfree(line);
 503                         break;
 504                 case 'T':
 505                         no_tty_flag = 1;
 506                         /* ensure that the user doesn't try to backdoor a */
 507                         /* null cipher switch on an interactive session */
 508                         /* so explicitly disable it no matter what */
 509                         options.none_switch=0;
 510                         break;
 511                 case 's':
 512                         subsystem_flag = 1;
 513                         break;
 514                 case 'S':
 515                         if (options.control_path != NULL)
 516                                 free(options.control_path);
 517                         options.control_path = xstrdup(optarg);
 518                         break;
 519                 case 'b':
 520                         options.bind_address = optarg;
 521                         break;
 522                 case 'F':
 523                         config = optarg;
 524                         break;
 525                 default:
 526                         usage();
 527                 }
 528         }
 529
 530         ac -= optind;
 531         av += optind;
 532
 533         if (ac > 0 && !host && **av != '-') {
 534                 if (strrchr(*av, '@')) {
 535                         p = xstrdup(*av);
 536                         cp = strrchr(p, '@');
 537                         if (cp == NULL || cp == p)
 538                                 usage();
 539                         options.user = p;
 540                         *cp = '\0';
 541                         host = ++cp;
 542                 } else
 543                         host = *av;
 544                 if (ac > 1) {
 545                         optind = optreset = 1;
 546                         goto again;
 547                 }
 548                 ac--, av++;
 549         }
 550
 551         /* Check that we got a host name. */
 552         if (!host)
 553                 usage();
 554
 555         SSLeay_add_all_algorithms();
 556         ERR_load_crypto_strings();
 557
 558         /* Initialize the command to execute on remote host. */
 559         buffer_init(&command);
 560
 561         /*
 562          * Save the command to execute on the remote host in a buffer. There
 563          * is no limit on the length of the command, except by the maximum
 564          * packet size.  Also sets the tty flag if there is no command.
 565          */
 566         if (!ac) {
 567                 /* No command specified - execute shell on a tty. */
 568                 tty_flag = 1;
 569                 if (subsystem_flag) {
 570                         fprintf(stderr,
 571                             "You must specify a subsystem to invoke.\n");
 572                         usage();
 573                 }
 574         } else {
 575                 /* A command has been specified.  Store it into the buffer. */
 576                 for (i = 0; i < ac; i++) {
 577                         if (i)
 578                                 buffer_append(&command, " ", 1);
 579                         buffer_append(&command, av[i], strlen(av[i]));
 580                 }
 581         }
 582
 583         /* Cannot fork to background if no command. */
 584         if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
 585             !no_shell_flag)
 586                 fatal("Cannot fork into background without a command "
 587                     "to execute.");
 588
 589         /* Allocate a tty by default if no command specified. */
 590         if (buffer_len(&command) == 0)
 591                 tty_flag = 1;
 592
 593         /* Force no tty */
 594         if (no_tty_flag)
 595                 tty_flag = 0;
 596         /* Do not allocate a tty if stdin is not a tty. */
 597         if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
 598                 if (tty_flag)
 599                         logit("Pseudo-terminal will not be allocated because "
 600                             "stdin is not a terminal.");
 601                 tty_flag = 0;
 602         }
 603
 604         /*
 605          * Initialize "log" output.  Since we are the client all output
 606          * actually goes to stderr.
 607          */
 608         log_init(av[0],
 609             options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
 610             SYSLOG_FACILITY_USER, !use_syslog);
 611
 612         /*
 613          * Read per-user configuration file.  Ignore the system wide config
 614          * file if the user specifies a config file on the command line.
 615          */
 616         if (config != NULL) {
 617                 if (!read_config_file(config, host, &options, 0))
 618                         fatal("Can't open user config file %.100s: "
 619                             "%.100s", config, strerror(errno));
 620         } else {
 621             /*
 622              * Since the config file parsing code aborts if it sees
 623              * options it doesn't recognize, allow users to put
 624              * options specific to compile-time add-ons in alternate
 625              * config files so their primary config file will
 626              * interoperate SSH versions that don't support those
 627              * options.
 628              */
 629 #ifdef GSSAPI
 630                 snprintf(buf, sizeof buf, "%.100s/%.100s.gssapi", pw->pw_dir,
 631                     _PATH_SSH_USER_CONFFILE);
 632                 (void)read_config_file(buf, host, &options, 1);
 633 #ifdef GSI
 634                 snprintf(buf, sizeof buf, "%.100s/%.100s.gsi", pw->pw_dir,
 635                     _PATH_SSH_USER_CONFFILE);
 636                 (void)read_config_file(buf, host, &options, 1);
 637 #endif
 638 #if defined(KRB5)
 639                 snprintf(buf, sizeof buf, "%.100s/%.100s.krb", pw->pw_dir,
 640                     _PATH_SSH_USER_CONFFILE);
 641                 (void)read_config_file(buf, host, &options, 1);
 642 #endif
 643 #endif
 644                 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
 645                     _PATH_SSH_USER_CONFFILE);
 646                 (void)read_config_file(buf, host, &options, 1);
 647
 648                 /* Read systemwide configuration file after use config. */
 649                 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
 650                     &options, 0);
 651         }
 652
 653         /* Fill configuration defaults. */
 654         fill_default_options(&options);
 655
 656         channel_set_af(options.address_family);
 657
 658         /* reinit */
 659         log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
 660
 661         seed_rng();
 662
 663         if (options.user == NULL) {
 664                 options.user = xstrdup(pw->pw_name);
 665                 options.implicit = 1;
 666         }
 667         else options.implicit = 0;
 668
 669         /* Get default port if port has not been set. */
 670         if (options.port == 0) {
 671                 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
 672                 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
 673         }
 674
 675         if (options.local_command != NULL) {
 676                 char thishost[NI_MAXHOST];
 677
 678                 if (gethostname(thishost, sizeof(thishost)) == -1)
 679                         fatal("gethostname: %s", strerror(errno));
 680                 snprintf(buf, sizeof(buf), "%d", options.port);
 681                 debug3("expanding LocalCommand: %s", options.local_command);
 682                 cp = options.local_command;
 683                 options.local_command = percent_expand(cp, "d", pw->pw_dir,
 684                     "h", options.hostname? options.hostname : host,
 685                     "l", thishost, "n", host, "r", options.user, "p", buf,
 686                     "u", pw->pw_name, (char *)NULL);
 687                 debug3("expanded LocalCommand: %s", options.local_command);
 688                 xfree(cp);
 689         }
 690
 691         if (options.hostname != NULL)
 692                 host = options.hostname;
 693
 694         /* force lowercase for hostkey matching */
 695         if (options.host_key_alias != NULL) {
 696                 for (p = options.host_key_alias; *p; p++)
 697                         if (isupper(*p))
 698                                 *p = (char)tolower(*p);
 699         }
 700
 701         if (options.proxy_command != NULL &&
 702             strcmp(options.proxy_command, "none") == 0) {
 703                 xfree(options.proxy_command);
 704                 options.proxy_command = NULL;
 705         }
 706         if (options.control_path != NULL &&
 707             strcmp(options.control_path, "none") == 0) {
 708                 xfree(options.control_path);
 709                 options.control_path = NULL;
 710         }
 711
 712         if (options.control_path != NULL) {
 713                 char thishost[NI_MAXHOST];
 714
 715                 if (gethostname(thishost, sizeof(thishost)) == -1)
 716                         fatal("gethostname: %s", strerror(errno));
 717                 snprintf(buf, sizeof(buf), "%d", options.port);
 718                 cp = tilde_expand_filename(options.control_path,
 719                     original_real_uid);
 720                 xfree(options.control_path);
 721                 options.control_path = percent_expand(cp, "p", buf, "h", host,
 722                     "r", options.user, "l", thishost, (char *)NULL);
 723                 xfree(cp);
 724         }
 725         if (muxclient_command != 0 && options.control_path == NULL)
 726                 fatal("No ControlPath specified for \"-O\" command");
 727         if (options.control_path != NULL)
 728                 muxclient(options.control_path);
 729
 730         timeout_ms = options.connection_timeout * 1000;
 731
 732         /* Open a connection to the remote host. */
 733         if (ssh_connect(host, &hostaddr, options.port,
 734             options.address_family, options.connection_attempts, &timeout_ms,
 735             options.tcp_keep_alive,
 736 #ifdef HAVE_CYGWIN
 737             options.use_privileged_port,
 738 #else
 739             original_effective_uid == 0 && options.use_privileged_port,
 740 #endif
 741             options.proxy_command) != 0)
 742                 exit(255);
 743
 744         if (timeout_ms > 0)
 745                 debug3("timeout: %d ms remain after connect", timeout_ms);
 746
 747         /*
 748          * If we successfully made the connection, load the host private key
 749          * in case we will need it later for combined rsa-rhosts
 750          * authentication. This must be done before releasing extra
 751          * privileges, because the file is only readable by root.
 752          * If we cannot access the private keys, load the public keys
 753          * instead and try to execute the ssh-keysign helper instead.
 754          */
 755         sensitive_data.nkeys = 0;
 756         sensitive_data.keys = NULL;
 757         sensitive_data.external_keysign = 0;
 758         if (options.rhosts_rsa_authentication ||
 759             options.hostbased_authentication) {
 760                 sensitive_data.nkeys = 3;
 761                 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
 762                     sizeof(Key));
 763
 764                 PRIV_START;
 765                 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
 766                     _PATH_HOST_KEY_FILE, "", NULL, NULL);
 767                 sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
 768                     _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
 769                 sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
 770                     _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
 771                 PRIV_END;
 772
 773                 if (options.hostbased_authentication == 1 &&
 774                     sensitive_data.keys[0] == NULL &&
 775                     sensitive_data.keys[1] == NULL &&
 776                     sensitive_data.keys[2] == NULL) {
 777                         sensitive_data.keys[1] = key_load_public(
 778                             _PATH_HOST_DSA_KEY_FILE, NULL);
 779                         sensitive_data.keys[2] = key_load_public(
 780                             _PATH_HOST_RSA_KEY_FILE, NULL);
 781                         sensitive_data.external_keysign = 1;
 782                 }
 783         }
 784         /*
 785          * Get rid of any extra privileges that we may have.  We will no
 786          * longer need them.  Also, extra privileges could make it very hard
 787          * to read identity files and other non-world-readable files from the
 788          * user's home directory if it happens to be on a NFS volume where
 789          * root is mapped to nobody.
 790          */
 791         if (original_effective_uid == 0) {
 792                 PRIV_START;
 793                 permanently_set_uid(pw);
 794         }
 795
 796         /*
 797          * Now that we are back to our own permissions, create ~/.ssh
 798          * directory if it doesn't already exist.
 799          */
 800         snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir,
 801             strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
 802         if (stat(buf, &st) < 0)
 803                 if (mkdir(buf, 0700) < 0)
 804                         error("Could not create directory '%.200s'.", buf);
 805
 806         /* load options.identity_files */
 807         load_public_identity_files();
 808
 809         /* Expand ~ in known host file names. */
 810         /* XXX mem-leaks: */
 811         options.system_hostfile =
 812             tilde_expand_filename(options.system_hostfile, original_real_uid);
 813         options.user_hostfile =
 814             tilde_expand_filename(options.user_hostfile, original_real_uid);
 815         options.system_hostfile2 =
 816             tilde_expand_filename(options.system_hostfile2, original_real_uid);
 817         options.user_hostfile2 =
 818             tilde_expand_filename(options.user_hostfile2, original_real_uid);
 819
 820         signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
 821
 822         /* Log into the remote system.  Never returns if the login fails. */
 823         ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
 824             pw, timeout_ms);
 825
 826         /* We no longer need the private host keys.  Clear them now. */
 827         if (sensitive_data.nkeys != 0) {
 828                 for (i = 0; i < sensitive_data.nkeys; i++) {
 829                         if (sensitive_data.keys[i] != NULL) {
 830                                 /* Destroys contents safely */
 831                                 debug3("clear hostkey %d", i);
 832                                 key_free(sensitive_data.keys[i]);
 833                                 sensitive_data.keys[i] = NULL;
 834                         }
 835                 }
 836                 xfree(sensitive_data.keys);
 837         }
 838         for (i = 0; i < options.num_identity_files; i++) {
 839                 if (options.identity_files[i]) {
 840                         xfree(options.identity_files[i]);
 841                         options.identity_files[i] = NULL;
 842                 }
 843                 if (options.identity_keys[i]) {
 844                         key_free(options.identity_keys[i]);
 845                         options.identity_keys[i] = NULL;
 846                 }
 847         }
 848
 849         exit_status = compat20 ? ssh_session2() : ssh_session();
 850         packet_close();
 851
 852         if (options.control_path != NULL && muxserver_sock != -1)
 853                 unlink(options.control_path);
 854
 855         /*
 856          * Send SIGHUP to proxy command if used. We don't wait() in
 857          * case it hangs and instead rely on init to reap the child
 858          */
 859         if (proxy_command_pid > 1)
 860                 kill(proxy_command_pid, SIGHUP);
 861
 862         return exit_status;
 863 }
 864
 865 /* Callback for remote forward global requests */
 866 static void
 867 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
 868 {
 869         Forward *rfwd = (Forward *)ctxt;
 870
 871         /* XXX verbose() on failure? */
 872         debug("remote forward %s for: listen %d, connect %s:%d",
 873             type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
 874             rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
 875         if (type == SSH2_MSG_REQUEST_SUCCESS && rfwd->listen_port == 0) {
 876                 logit("Allocated port %u for remote forward to %s:%d",
 877                         packet_get_int(),
 878                         rfwd->connect_host, rfwd->connect_port);
 879         }
 880
 881         if (type == SSH2_MSG_REQUEST_FAILURE) {
 882                 if (options.exit_on_forward_failure)
 883                         fatal("Error: remote port forwarding failed for "
 884                             "listen port %d", rfwd->listen_port);
 885                 else
 886                         logit("Warning: remote port forwarding failed for "
 887                             "listen port %d", rfwd->listen_port);
 888         }
 889         if (++remote_forward_confirms_received == options.num_remote_forwards) {
 890                 debug("All remote forwarding requests processed");
 891                 if (fork_after_authentication_flag) {
 892                         fork_after_authentication_flag = 0;
 893                         if (daemon(1, 1) < 0)
 894                                 fatal("daemon() failed: %.200s",
 895                                     strerror(errno));
 896                 }
 897         }
 898 }
 899
 900 static void
 901 ssh_init_forwarding(void)
 902 {
 903         int success = 0;
 904         int i;
 905
 906         /* Initiate local TCP/IP port forwardings. */
 907         for (i = 0; i < options.num_local_forwards; i++) {
 908                 debug("Local connections to %.200s:%d forwarded to remote "
 909                     "address %.200s:%d",
 910                     (options.local_forwards[i].listen_host == NULL) ?
 911                     (options.gateway_ports ? "*" : "LOCALHOST") :
 912                     options.local_forwards[i].listen_host,
 913                     options.local_forwards[i].listen_port,
 914                     options.local_forwards[i].connect_host,
 915                     options.local_forwards[i].connect_port);
 916                 success += channel_setup_local_fwd_listener(
 917                     options.local_forwards[i].listen_host,
 918                     options.local_forwards[i].listen_port,
 919                     options.local_forwards[i].connect_host,
 920                     options.local_forwards[i].connect_port,
 921                     options.gateway_ports);
 922         }
 923         if (i > 0 && success != i && options.exit_on_forward_failure)
 924                 fatal("Could not request local forwarding.");
 925         if (i > 0 && success == 0)
 926                 error("Could not request local forwarding.");
 927
 928         /* Initiate remote TCP/IP port forwardings. */
 929         for (i = 0; i < options.num_remote_forwards; i++) {
 930                 debug("Remote connections from %.200s:%d forwarded to "
 931                     "local address %.200s:%d",
 932                     (options.remote_forwards[i].listen_host == NULL) ?
 933                     "LOCALHOST" : options.remote_forwards[i].listen_host,
 934                     options.remote_forwards[i].listen_port,
 935                     options.remote_forwards[i].connect_host,
 936                     options.remote_forwards[i].connect_port);
 937                 if (channel_request_remote_forwarding(
 938                     options.remote_forwards[i].listen_host,
 939                     options.remote_forwards[i].listen_port,
 940                     options.remote_forwards[i].connect_host,
 941                     options.remote_forwards[i].connect_port) < 0) {
 942                         if (options.exit_on_forward_failure)
 943                                 fatal("Could not request remote forwarding.");
 944                         else
 945                                 logit("Warning: Could not request remote "
 946                                     "forwarding.");
 947                 }
 948                 client_register_global_confirm(ssh_confirm_remote_forward,
 949                     &options.remote_forwards[i]);
 950         }
 951
 952         /* Initiate tunnel forwarding. */
 953         if (options.tun_open != SSH_TUNMODE_NO) {
 954                 if (client_request_tun_fwd(options.tun_open,
 955                     options.tun_local, options.tun_remote) == -1) {
 956                         if (options.exit_on_forward_failure)
 957                                 fatal("Could not request tunnel forwarding.");
 958                         else
 959                                 error("Could not request tunnel forwarding.");
 960                 }
 961         }
 962 }
 963
 964 static void
 965 check_agent_present(void)
 966 {
 967         if (options.forward_agent) {
 968                 /* Clear agent forwarding if we don't have an agent. */
 969                 if (!ssh_agent_present())
 970                         options.forward_agent = 0;
 971         }
 972 }
 973
 974 static int
 975 ssh_session(void)
 976 {
 977         int type;
 978         int interactive = 0;
 979         int have_tty = 0;
 980         struct winsize ws;
 981         char *cp;
 982         const char *display;
 983
 984         /* Enable compression if requested. */
 985         if (options.compression) {
 986                 debug("Requesting compression at level %d.",
 987                     options.compression_level);
 988
 989                 if (options.compression_level < 1 ||
 990                     options.compression_level > 9)
 991                         fatal("Compression level must be from 1 (fast) to "
 992                             "9 (slow, best).");
 993
 994                 /* Send the request. */
 995                 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
 996                 packet_put_int(options.compression_level);
 997                 packet_send();
 998                 packet_write_wait();
 999                 type = packet_read();
1000                 if (type == SSH_SMSG_SUCCESS)
1001                         packet_start_compression(options.compression_level);
1002                 else if (type == SSH_SMSG_FAILURE)
1003                         logit("Warning: Remote host refused compression.");
1004                 else
1005                         packet_disconnect("Protocol error waiting for "
1006                             "compression response.");
1007         }
1008         /* Allocate a pseudo tty if appropriate. */
1009         if (tty_flag) {
1010                 debug("Requesting pty.");
1011
1012                 /* Start the packet. */
1013                 packet_start(SSH_CMSG_REQUEST_PTY);
1014
1015                 /* Store TERM in the packet.  There is no limit on the
1016                    length of the string. */
1017                 cp = getenv("TERM");
1018                 if (!cp)
1019                         cp = "";
1020                 packet_put_cstring(cp);
1021
1022                 /* Store window size in the packet. */
1023                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
1024                         memset(&ws, 0, sizeof(ws));
1025                 packet_put_int((u_int)ws.ws_row);
1026                 packet_put_int((u_int)ws.ws_col);
1027                 packet_put_int((u_int)ws.ws_xpixel);
1028                 packet_put_int((u_int)ws.ws_ypixel);
1029
1030                 /* Store tty modes in the packet. */
1031                 tty_make_modes(fileno(stdin), NULL);
1032
1033                 /* Send the packet, and wait for it to leave. */
1034                 packet_send();
1035                 packet_write_wait();
1036
1037                 /* Read response from the server. */
1038                 type = packet_read();
1039                 if (type == SSH_SMSG_SUCCESS) {
1040                         interactive = 1;
1041                         have_tty = 1;
1042                 } else if (type == SSH_SMSG_FAILURE)
1043                         logit("Warning: Remote host failed or refused to "
1044                             "allocate a pseudo tty.");
1045                 else
1046                         packet_disconnect("Protocol error waiting for pty "
1047                             "request response.");
1048         }
1049         /* Request X11 forwarding if enabled and DISPLAY is set. */
1050         display = getenv("DISPLAY");
1051         if (options.forward_x11 && display != NULL) {
1052                 char *proto, *data;
1053                 /* Get reasonable local authentication information. */
1054                 client_x11_get_proto(display, options.xauth_location,
1055                     options.forward_x11_trusted, &proto, &data);
1056                 /* Request forwarding with authentication spoofing. */
1057                 debug("Requesting X11 forwarding with authentication "
1058                     "spoofing.");
1059                 x11_request_forwarding_with_spoofing(0, display, proto, data);
1060
1061                 /* Read response from the server. */
1062                 type = packet_read();
1063                 if (type == SSH_SMSG_SUCCESS) {
1064                         interactive = 1;
1065                 } else if (type == SSH_SMSG_FAILURE) {
1066                         logit("Warning: Remote host denied X11 forwarding.");
1067                 } else {
1068                         packet_disconnect("Protocol error waiting for X11 "
1069                             "forwarding");
1070                 }
1071         }
1072         /* Tell the packet module whether this is an interactive session. */
1073         packet_set_interactive(interactive);
1074
1075         /* Request authentication agent forwarding if appropriate. */
1076         check_agent_present();
1077
1078         if (options.forward_agent) {
1079                 debug("Requesting authentication agent forwarding.");
1080                 auth_request_forwarding();
1081
1082                 /* Read response from the server. */
1083                 type = packet_read();
1084                 packet_check_eom();
1085                 if (type != SSH_SMSG_SUCCESS)
1086                         logit("Warning: Remote host denied authentication agent forwarding.");
1087         }
1088
1089         /* Initiate port forwardings. */
1090         ssh_init_forwarding();
1091
1092         /* Execute a local command */
1093         if (options.local_command != NULL &&
1094             options.permit_local_command)
1095                 ssh_local_cmd(options.local_command);
1096
1097         /*
1098          * If requested and we are not interested in replies to remote
1099          * forwarding requests, then let ssh continue in the background.
1100          */
1101         if (fork_after_authentication_flag &&
1102             (!options.exit_on_forward_failure ||
1103             options.num_remote_forwards == 0)) {
1104                 fork_after_authentication_flag = 0;
1105                 if (daemon(1, 1) < 0)
1106                         fatal("daemon() failed: %.200s", strerror(errno));
1107         }
1108
1109         /*
1110          * If a command was specified on the command line, execute the
1111          * command now. Otherwise request the server to start a shell.
1112          */
1113         if (buffer_len(&command) > 0) {
1114                 int len = buffer_len(&command);
1115                 if (len > 900)
1116                         len = 900;
1117                 debug("Sending command: %.*s", len,
1118                     (u_char *)buffer_ptr(&command));
1119                 packet_start(SSH_CMSG_EXEC_CMD);
1120                 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1121                 packet_send();
1122                 packet_write_wait();
1123         } else {
1124                 debug("Requesting shell.");
1125                 packet_start(SSH_CMSG_EXEC_SHELL);
1126                 packet_send();
1127                 packet_write_wait();
1128         }
1129
1130         /* Enter the interactive session. */
1131         return client_loop(have_tty, tty_flag ?
1132             options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1133 }
1134
1135 /* request pty/x11/agent/tcpfwd/shell for channel */
1136 static void
1137 ssh_session2_setup(int id, void *arg)
1138 {
1139         extern char **environ;
1140         const char *display;
1141         int interactive = tty_flag;
1142
1143         display = getenv("DISPLAY");
1144         if (options.forward_x11 && display != NULL) {
1145                 char *proto, *data;
1146                 /* Get reasonable local authentication information. */
1147                 client_x11_get_proto(display, options.xauth_location,
1148                     options.forward_x11_trusted, &proto, &data);
1149                 /* Request forwarding with authentication spoofing. */
1150                 debug("Requesting X11 forwarding with authentication "
1151                     "spoofing.");
1152                 x11_request_forwarding_with_spoofing(id, display, proto, data);
1153                 interactive = 1;
1154                 /* XXX wait for reply */
1155         }
1156
1157         check_agent_present();
1158         if (options.forward_agent) {
1159                 debug("Requesting authentication agent forwarding.");
1160                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1161                 packet_send();
1162         }
1163
1164         client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1165             NULL, fileno(stdin), &command, environ);
1166
1167         packet_set_interactive(interactive);
1168 }
1169
1170 /* open new channel for a session */
1171 static int
1172 ssh_session2_open(void)
1173 {
1174         Channel *c;
1175         int window, packetmax, in, out, err;
1176         int sock;
1177         int socksize;
1178         int socksizelen = sizeof(int);
1179
1180         if (stdin_null_flag) {
1181                 in = open(_PATH_DEVNULL, O_RDONLY);
1182         } else {
1183                 in = dup(STDIN_FILENO);
1184         }
1185         out = dup(STDOUT_FILENO);
1186         err = dup(STDERR_FILENO);
1187
1188         if (in < 0 || out < 0 || err < 0)
1189                 fatal("dup() in/out/err failed");
1190
1191         /* enable nonblocking unless tty */
1192         if (!isatty(in))
1193                 set_nonblock(in);
1194         if (!isatty(out))
1195                 set_nonblock(out);
1196         if (!isatty(err))
1197                 set_nonblock(err);
1198
1199         /* we need to check to see if what they want to do about buffer */
1200         /* sizes here. In a hpn to nonhpn connection we want to limit */
1201         /* the window size to something reasonable in case the far side */
1202         /* has the large window bug. In hpn to hpn connection we want to */
1203         /* use the max window size but allow the user to override it */
1204         /* lastly if they disabled hpn then use the ssh std window size */
1205
1206         /* so why don't we just do a getsockopt() here and set the */
1207         /* ssh window to that? In the case of a autotuning receive */
1208         /* window the window would get stuck at the initial buffer */
1209         /* size generally less than 96k. Therefore we need to set the */
1210         /* maximum ssh window size to the maximum hpn buffer size */
1211         /* unless the user has specifically set the tcprcvbufpoll */
1212         /* to no. In which case we *can* just set the window to the */
1213         /* minimum of the hpn buffer size and tcp receive buffer size */
1214
1215         if (tty_flag)
1216                 options.hpn_buffer_size = CHAN_SES_WINDOW_DEFAULT;
1217         else
1218                 options.hpn_buffer_size = 2*1024*1024;
1219
1220         if (datafellows & SSH_BUG_LARGEWINDOW)
1221         {
1222                 debug("HPN to Non-HPN Connection");
1223         }
1224         else
1225         {
1226                 if (options.tcp_rcv_buf_poll <= 0)
1227                 {
1228                         sock = socket(AF_INET, SOCK_STREAM, 0);
1229                         getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1230                                    &socksize, &socksizelen);
1231                         close(sock);
1232                         debug("socksize %d", socksize);
1233                         options.hpn_buffer_size = socksize;
1234                         debug ("HPNBufferSize set to TCP RWIN: %d", options.hpn_buffer_size);
1235                 }
1236                 else
1237                 {
1238                         if (options.tcp_rcv_buf > 0)
1239                         {
1240                                 /*create a socket but don't connect it */
1241                                 /* we use that the get the rcv socket size */
1242                                 sock = socket(AF_INET, SOCK_STREAM, 0);
1243                                 /* if they are using the tcp_rcv_buf option */
1244                                 /* attempt to set the buffer size to that */
1245                                 if (options.tcp_rcv_buf)
1246                                         setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void *)&options.tcp_rcv_buf,
1247                                                    sizeof(options.tcp_rcv_buf));
1248                                 getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1249                                            &socksize, &socksizelen);
1250                                 close(sock);
1251                                 debug("socksize %d", socksize);
1252                                 options.hpn_buffer_size = socksize;
1253                                 debug ("HPNBufferSize set to user TCPRcvBuf: %d", options.hpn_buffer_size);
1254                         }
1255                 }
1256
1257         }
1258
1259         debug("Final hpn_buffer_size = %d", options.hpn_buffer_size);
1260
1261         window = options.hpn_buffer_size;
1262
1263         channel_set_hpn(options.hpn_disabled, options.hpn_buffer_size);
1264
1265         packetmax = CHAN_SES_PACKET_DEFAULT;
1266         if (tty_flag) {
1267                 window = 4*CHAN_SES_PACKET_DEFAULT;
1268                 window >>= 1;
1269                 packetmax >>= 1;
1270         }
1271         c = channel_new(
1272             "session", SSH_CHANNEL_OPENING, in, out, err,
1273             window, packetmax, CHAN_EXTENDED_WRITE,
1274             "client-session", /*nonblock*/0);
1275         if ((options.tcp_rcv_buf_poll > 0) && (!options.hpn_disabled)) {
1276                 c->dynamic_window = 1;
1277                 debug ("Enabled Dynamic Window Scaling\n");
1278         }
1279         debug3("ssh_session2_open: channel_new: %d", c->self);
1280
1281         channel_send_open(c->self);
1282         if (!no_shell_flag)
1283                 channel_register_open_confirm(c->self,
1284                     ssh_session2_setup, NULL);
1285
1286         return c->self;
1287 }
1288
1289 static int
1290 ssh_session2(void)
1291 {
1292         int id = -1;
1293
1294         /* XXX should be pre-session */
1295         ssh_init_forwarding();
1296
1297         if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1298                 id = ssh_session2_open();
1299
1300         /* If we don't expect to open a new session, then disallow it */
1301         if (options.control_master == SSHCTL_MASTER_NO &&
1302             (datafellows & SSH_NEW_OPENSSH)) {
1303                 debug("Requesting no-more-sessions@openssh.com");
1304                 packet_start(SSH2_MSG_GLOBAL_REQUEST);
1305                 packet_put_cstring("no-more-sessions@openssh.com");
1306                 packet_put_char(0);
1307                 packet_send();
1308         }
1309
1310         /* Execute a local command */
1311         if (options.local_command != NULL &&
1312             options.permit_local_command)
1313                 ssh_local_cmd(options.local_command);
1314
1315         /* Start listening for multiplex clients */
1316         muxserver_listen();
1317
1318         /* If requested, let ssh continue in the background. */
1319         if (fork_after_authentication_flag) {
1320                 fork_after_authentication_flag = 0;
1321                 if (daemon(1, 1) < 0)
1322                         fatal("daemon() failed: %.200s", strerror(errno));
1323         }
1324
1325         return client_loop(tty_flag, tty_flag ?
1326             options.escape_char : SSH_ESCAPECHAR_NONE, id);
1327 }
1328
1329 static void
1330 load_public_identity_files(void)
1331 {
1332         char *filename, *cp, thishost[NI_MAXHOST];
1333         char *pwdir = NULL, *pwname = NULL;
1334         int i = 0;
1335         Key *public;
1336         struct passwd *pw;
1337 #ifdef SMARTCARD
1338         Key **keys;
1339
1340         if (options.smartcard_device != NULL &&
1341             options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1342             (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL) {
1343                 int count = 0;
1344                 for (i = 0; keys[i] != NULL; i++) {
1345                         count++;
1346                         memmove(&options.identity_files[1],
1347                             &options.identity_files[0],
1348                             sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1));
1349                         memmove(&options.identity_keys[1],
1350                             &options.identity_keys[0],
1351                             sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1));
1352                         options.num_identity_files++;
1353                         options.identity_keys[0] = keys[i];
1354                         options.identity_files[0] = sc_get_key_label(keys[i]);
1355                 }
1356                 if (options.num_identity_files > SSH_MAX_IDENTITY_FILES)
1357                         options.num_identity_files = SSH_MAX_IDENTITY_FILES;
1358                 i = count;
1359                 xfree(keys);
1360         }
1361 #endif /* SMARTCARD */
1362         if ((pw = getpwuid(original_real_uid)) == NULL)
1363                 fatal("load_public_identity_files: getpwuid failed");
1364         pwname = xstrdup(pw->pw_name);
1365         pwdir = xstrdup(pw->pw_dir);
1366         if (gethostname(thishost, sizeof(thishost)) == -1)
1367                 fatal("load_public_identity_files: gethostname: %s",
1368                     strerror(errno));
1369         for (; i < options.num_identity_files; i++) {
1370                 cp = tilde_expand_filename(options.identity_files[i],
1371                     original_real_uid);
1372                 filename = percent_expand(cp, "d", pwdir,
1373                     "u", pwname, "l", thishost, "h", host,
1374                     "r", options.user, (char *)NULL);
1375                 xfree(cp);
1376                 public = key_load_public(filename, NULL);
1377                 debug("identity file %s type %d", filename,
1378                     public ? public->type : -1);
1379                 xfree(options.identity_files[i]);
1380                 options.identity_files[i] = filename;
1381                 options.identity_keys[i] = public;
1382         }
1383         bzero(pwname, strlen(pwname));
1384         xfree(pwname);
1385         bzero(pwdir, strlen(pwdir));
1386         xfree(pwdir);
1387 }