openssh/ssh.c

   1 /* $OpenBSD: ssh.c,v 1.326 2009/07/02 02:11:47 dtucker 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/param.h>
  52 #include <sys/socket.h>
  53
  54 #include <ctype.h>
  55 #include <errno.h>
  56 #include <fcntl.h>
  57 #include <netdb.h>
  58 #ifdef HAVE_PATHS_H
  59 #include <paths.h>
  60 #endif
  61 #include <pwd.h>
  62 #include <signal.h>
  63 #include <stdarg.h>
  64 #include <stddef.h>
  65 #include <stdio.h>
  66 #include <stdlib.h>
  67 #include <string.h>
  68 #include <unistd.h>
  69
  70 #include <netinet/in.h>
  71 #include <arpa/inet.h>
  72
  73 #include <openssl/evp.h>
  74 #include <openssl/err.h>
  75 #include "openbsd-compat/openssl-compat.h"
  76 #include "openbsd-compat/sys-queue.h"
  77
  78 #include "xmalloc.h"
  79 #include "ssh.h"
  80 #include "ssh1.h"
  81 #include "ssh2.h"
  82 #include "compat.h"
  83 #include "cipher.h"
  84 #include "packet.h"
  85 #include "buffer.h"
  86 #include "channels.h"
  87 #include "key.h"
  88 #include "authfd.h"
  89 #include "authfile.h"
  90 #include "pathnames.h"
  91 #include "dispatch.h"
  92 #include "clientloop.h"
  93 #include "log.h"
  94 #include "readconf.h"
  95 #include "sshconnect.h"
  96 #include "misc.h"
  97 #include "kex.h"
  98 #include "mac.h"
  99 #include "sshpty.h"
 100 #include "match.h"
 101 #include "msg.h"
 102 #include "uidswap.h"
 103 #include "version.h"
 104
 105 #ifdef SMARTCARD
 106 #include "scard.h"
 107 #endif
 108
 109 extern char *__progname;
 110
 111 /* Flag indicating whether debug mode is on.  May be set on the command line. */
 112 int debug_flag = 0;
 113
 114 /* Flag indicating whether a tty should be allocated */
 115 int tty_flag = 0;
 116 int no_tty_flag = 0;
 117 int force_tty_flag = 0;
 118
 119 /* don't exec a shell */
 120 int no_shell_flag = 0;
 121
 122 /*
 123  * Flag indicating that nothing should be read from stdin.  This can be set
 124  * on the command line.
 125  */
 126 int stdin_null_flag = 0;
 127
 128 /*
 129  * Flag indicating that ssh should fork after authentication.  This is useful
 130  * so that the passphrase can be entered manually, and then ssh goes to the
 131  * background.
 132  */
 133 int fork_after_authentication_flag = 0;
 134
 135 /*
 136  * General data structure for command line options and options configurable
 137  * in configuration files.  See readconf.h.
 138  */
 139 Options options;
 140
 141 /* optional user configfile */
 142 char *config = NULL;
 143
 144 /*
 145  * Name of the host we are connecting to.  This is the name given on the
 146  * command line, or the HostName specified for the user-supplied name in a
 147  * configuration file.
 148  */
 149 char *host;
 150
 151 /* socket address the host resolves to */
 152 struct sockaddr_storage hostaddr;
 153
 154 /* Private host keys. */
 155 Sensitive sensitive_data;
 156
 157 /* Original real UID. */
 158 uid_t original_real_uid;
 159 uid_t original_effective_uid;
 160
 161 /* command to be executed */
 162 Buffer command;
 163
 164 /* Should we execute a command or invoke a subsystem? */
 165 int subsystem_flag = 0;
 166
 167 /* # of replies received for global requests */
 168 static int remote_forward_confirms_received = 0;
 169
 170 /* pid of proxycommand child process */
 171 pid_t proxy_command_pid = 0;
 172
 173 /* mux.c */
 174 extern int muxserver_sock;
 175 extern u_int muxclient_command;
 176
 177 /* Prints a help message to the user.  This function never returns. */
 178
 179 static void
 180 usage(void)
 181 {
 182         fprintf(stderr,
 183 "usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n"
 184 "           [-D [bind_address:]port] [-e escape_char] [-F configfile]\n"
 185 "           [-i identity_file] [-L [bind_address:]port:host:hostport]\n"
 186 "           [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
 187 "           [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
 188 "           [-w local_tun[:remote_tun]] [user@]hostname [command]\n"
 189         );
 190         exit(255);
 191 }
 192
 193 static int ssh_session(void);
 194 static int ssh_session2(void);
 195 static void load_public_identity_files(void);
 196
 197 /* from muxclient.c */
 198 void muxclient(const char *);
 199 void muxserver_listen(void);
 200
 201 /*
 202  * Main program for the ssh client.
 203  */
 204 int
 205 main(int ac, char **av)
 206 {
 207         int i, r, opt, exit_status, use_syslog;
 208         char *p, *cp, *line, *argv0, buf[MAXPATHLEN];
 209         struct stat st;
 210         struct passwd *pw;
 211         int dummy, timeout_ms;
 212         extern int optind, optreset;
 213         extern char *optarg;
 214         struct servent *sp;
 215         Forward fwd;
 216
 217         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 218         sanitise_stdfd();
 219
 220         __progname = ssh_get_progname(av[0]);
 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         argv0 = av[0];
 275
 276  again:
 277         while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
 278             "ACD:F:I:KL:MNO:PR:S:TVw:XYy")) != -1) {
 279                 switch (opt) {
 280                 case '1':
 281                         options.protocol = SSH_PROTO_1;
 282                         break;
 283                 case '2':
 284                         options.protocol = SSH_PROTO_2;
 285                         break;
 286                 case '4':
 287                         options.address_family = AF_INET;
 288                         break;
 289                 case '6':
 290                         options.address_family = AF_INET6;
 291                         break;
 292                 case 'n':
 293                         stdin_null_flag = 1;
 294                         break;
 295                 case 'f':
 296                         fork_after_authentication_flag = 1;
 297                         stdin_null_flag = 1;
 298                         break;
 299                 case 'x':
 300                         options.forward_x11 = 0;
 301                         break;
 302                 case 'X':
 303                         options.forward_x11 = 1;
 304                         break;
 305                 case 'y':
 306                         use_syslog = 1;
 307                         break;
 308                 case 'Y':
 309                         options.forward_x11 = 1;
 310                         options.forward_x11_trusted = 1;
 311                         break;
 312                 case 'g':
 313                         options.gateway_ports = 1;
 314                         break;
 315                 case 'O':
 316                         if (strcmp(optarg, "check") == 0)
 317                                 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
 318                         else if (strcmp(optarg, "exit") == 0)
 319                                 muxclient_command = SSHMUX_COMMAND_TERMINATE;
 320                         else
 321                                 fatal("Invalid multiplex command.");
 322                         break;
 323                 case 'P':       /* deprecated */
 324                         options.use_privileged_port = 0;
 325                         break;
 326                 case 'a':
 327                         options.forward_agent = 0;
 328                         break;
 329                 case 'A':
 330                         options.forward_agent = 1;
 331                         break;
 332                 case 'k':
 333                         options.gss_deleg_creds = 0;
 334                         break;
 335                 case 'K':
 336                         options.gss_authentication = 1;
 337                         options.gss_deleg_creds = 1;
 338                         break;
 339                 case 'i':
 340                         if (stat(optarg, &st) < 0) {
 341                                 fprintf(stderr, "Warning: Identity file %s "
 342                                     "not accessible: %s.\n", optarg,
 343                                     strerror(errno));
 344                                 break;
 345                         }
 346                         if (options.num_identity_files >=
 347                             SSH_MAX_IDENTITY_FILES)
 348                                 fatal("Too many identity files specified "
 349                                     "(max %d)", SSH_MAX_IDENTITY_FILES);
 350                         options.identity_files[options.num_identity_files++] =
 351                             xstrdup(optarg);
 352                         break;
 353                 case 'I':
 354 #ifdef SMARTCARD
 355                         options.smartcard_device = xstrdup(optarg);
 356 #else
 357                         fprintf(stderr, "no support for smartcards.\n");
 358 #endif
 359                         break;
 360                 case 't':
 361                         if (tty_flag)
 362                                 force_tty_flag = 1;
 363                         tty_flag = 1;
 364                         break;
 365                 case 'v':
 366                         if (debug_flag == 0) {
 367                                 debug_flag = 1;
 368                                 options.log_level = SYSLOG_LEVEL_DEBUG1;
 369                         } else {
 370                                 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
 371                                         options.log_level++;
 372                                 break;
 373                         }
 374                         /* FALLTHROUGH */
 375                 case 'V':
 376                         fprintf(stderr, "%s, %s\n",
 377                             SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
 378                         if (opt == 'V')
 379                                 exit(0);
 380                         break;
 381                 case 'w':
 382                         if (options.tun_open == -1)
 383                                 options.tun_open = SSH_TUNMODE_DEFAULT;
 384                         options.tun_local = a2tun(optarg, &options.tun_remote);
 385                         if (options.tun_local == SSH_TUNID_ERR) {
 386                                 fprintf(stderr,
 387                                     "Bad tun device '%s'\n", optarg);
 388                                 exit(255);
 389                         }
 390                         break;
 391                 case 'q':
 392                         options.log_level = SYSLOG_LEVEL_QUIET;
 393                         break;
 394                 case 'e':
 395                         if (optarg[0] == '^' && optarg[2] == 0 &&
 396                             (u_char) optarg[1] >= 64 &&
 397                             (u_char) optarg[1] < 128)
 398                                 options.escape_char = (u_char) optarg[1] & 31;
 399                         else if (strlen(optarg) == 1)
 400                                 options.escape_char = (u_char) optarg[0];
 401                         else if (strcmp(optarg, "none") == 0)
 402                                 options.escape_char = SSH_ESCAPECHAR_NONE;
 403                         else {
 404                                 fprintf(stderr, "Bad escape character '%s'.\n",
 405                                     optarg);
 406                                 exit(255);
 407                         }
 408                         break;
 409                 case 'c':
 410                         if (ciphers_valid(optarg)) {
 411                                 /* SSH2 only */
 412                                 options.ciphers = xstrdup(optarg);
 413                                 options.cipher = SSH_CIPHER_INVALID;
 414                         } else {
 415                                 /* SSH1 only */
 416                                 options.cipher = cipher_number(optarg);
 417                                 if (options.cipher == -1) {
 418                                         fprintf(stderr,
 419                                             "Unknown cipher type '%s'\n",
 420                                             optarg);
 421                                         exit(255);
 422                                 }
 423                                 if (options.cipher == SSH_CIPHER_3DES)
 424                                         options.ciphers = "3des-cbc";
 425                                 else if (options.cipher == SSH_CIPHER_BLOWFISH)
 426                                         options.ciphers = "blowfish-cbc";
 427                                 else
 428                                         options.ciphers = (char *)-1;
 429                         }
 430                         break;
 431                 case 'm':
 432                         if (mac_valid(optarg))
 433                                 options.macs = xstrdup(optarg);
 434                         else {
 435                                 fprintf(stderr, "Unknown mac type '%s'\n",
 436                                     optarg);
 437                                 exit(255);
 438                         }
 439                         break;
 440                 case 'M':
 441                         if (options.control_master == SSHCTL_MASTER_YES)
 442                                 options.control_master = SSHCTL_MASTER_ASK;
 443                         else
 444                                 options.control_master = SSHCTL_MASTER_YES;
 445                         break;
 446                 case 'p':
 447                         options.port = a2port(optarg);
 448                         if (options.port <= 0) {
 449                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 450                                 exit(255);
 451                         }
 452                         break;
 453                 case 'l':
 454                         options.user = optarg;
 455                         break;
 456
 457                 case 'L':
 458                         if (parse_forward(&fwd, optarg, 0, 0))
 459                                 add_local_forward(&options, &fwd);
 460                         else {
 461                                 fprintf(stderr,
 462                                     "Bad local forwarding specification '%s'\n",
 463                                     optarg);
 464                                 exit(255);
 465                         }
 466                         break;
 467
 468                 case 'R':
 469                         if (parse_forward(&fwd, optarg, 0, 1)) {
 470                                 add_remote_forward(&options, &fwd);
 471                         } else {
 472                                 fprintf(stderr,
 473                                     "Bad remote forwarding specification "
 474                                     "'%s'\n", optarg);
 475                                 exit(255);
 476                         }
 477                         break;
 478
 479                 case 'D':
 480                         if (parse_forward(&fwd, optarg, 1, 0)) {
 481                                 add_local_forward(&options, &fwd);
 482                         } else {
 483                                 fprintf(stderr,
 484                                     "Bad dynamic forwarding specification "
 485                                     "'%s'\n", optarg);
 486                                 exit(255);
 487                         }
 488                         break;
 489
 490                 case 'C':
 491                         options.compression = 1;
 492                         break;
 493                 case 'N':
 494                         no_shell_flag = 1;
 495                         no_tty_flag = 1;
 496                         break;
 497                 case 'o':
 498                         dummy = 1;
 499                         line = xstrdup(optarg);
 500                         if (process_config_line(&options, host ? host : "",
 501                             line, "command-line", 0, &dummy) != 0)
 502                                 exit(255);
 503                         xfree(line);
 504                         break;
 505                 case 'T':
 506                         no_tty_flag = 1;
 507                         /* ensure that the user doesn't try to backdoor a */
 508                         /* null cipher switch on an interactive session */
 509                         /* so explicitly disable it no matter what */
 510                         options.none_switch=0;
 511                         break;
 512                 case 's':
 513                         subsystem_flag = 1;
 514                         break;
 515                 case 'S':
 516                         if (options.control_path != NULL)
 517                                 free(options.control_path);
 518                         options.control_path = xstrdup(optarg);
 519                         break;
 520                 case 'b':
 521                         options.bind_address = optarg;
 522                         break;
 523                 case 'F':
 524                         config = optarg;
 525                         break;
 526                 default:
 527                         usage();
 528                 }
 529         }
 530
 531         ac -= optind;
 532         av += optind;
 533
 534         if (ac > 0 && !host && **av != '-') {
 535                 if (strrchr(*av, '@')) {
 536                         p = xstrdup(*av);
 537                         cp = strrchr(p, '@');
 538                         if (cp == NULL || cp == p)
 539                                 usage();
 540                         options.user = p;
 541                         *cp = '\0';
 542                         host = ++cp;
 543                 } else
 544                         host = *av;
 545                 if (ac > 1) {
 546                         optind = optreset = 1;
 547                         goto again;
 548                 }
 549                 ac--, av++;
 550         }
 551
 552         /* Check that we got a host name. */
 553         if (!host)
 554                 usage();
 555
 556         SSLeay_add_all_algorithms();
 557         ERR_load_crypto_strings();
 558
 559         /* Initialize the command to execute on remote host. */
 560         buffer_init(&command);
 561
 562         /*
 563          * Save the command to execute on the remote host in a buffer. There
 564          * is no limit on the length of the command, except by the maximum
 565          * packet size.  Also sets the tty flag if there is no command.
 566          */
 567         if (!ac) {
 568                 /* No command specified - execute shell on a tty. */
 569                 tty_flag = 1;
 570                 if (subsystem_flag) {
 571                         fprintf(stderr,
 572                             "You must specify a subsystem to invoke.\n");
 573                         usage();
 574                 }
 575         } else {
 576                 /* A command has been specified.  Store it into the buffer. */
 577                 for (i = 0; i < ac; i++) {
 578                         if (i)
 579                                 buffer_append(&command, " ", 1);
 580                         buffer_append(&command, av[i], strlen(av[i]));
 581                 }
 582         }
 583
 584         /* Cannot fork to background if no command. */
 585         if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
 586             !no_shell_flag)
 587                 fatal("Cannot fork into background without a command "
 588                     "to execute.");
 589
 590         /* Allocate a tty by default if no command specified. */
 591         if (buffer_len(&command) == 0)
 592                 tty_flag = 1;
 593
 594         /* Force no tty */
 595         if (no_tty_flag)
 596                 tty_flag = 0;
 597         /* Do not allocate a tty if stdin is not a tty. */
 598         if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
 599                 if (tty_flag)
 600                         logit("Pseudo-terminal will not be allocated because "
 601                             "stdin is not a terminal.");
 602                 tty_flag = 0;
 603         }
 604
 605         /*
 606          * Initialize "log" output.  Since we are the client all output
 607          * actually goes to stderr.
 608          */
 609         log_init(argv0,
 610             options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
 611             SYSLOG_FACILITY_USER, !use_syslog);
 612
 613         /*
 614          * Read per-user configuration file.  Ignore the system wide config
 615          * file if the user specifies a config file on the command line.
 616          */
 617         if (config != NULL) {
 618                 if (!read_config_file(config, host, &options, 0))
 619                         fatal("Can't open user config file %.100s: "
 620                             "%.100s", config, strerror(errno));
 621         } else {
 622             /*
 623              * Since the config file parsing code aborts if it sees
 624              * options it doesn't recognize, allow users to put
 625              * options specific to compile-time add-ons in alternate
 626              * config files so their primary config file will
 627              * interoperate SSH versions that don't support those
 628              * options.
 629              */
 630 #ifdef GSSAPI
 631                 r = snprintf(buf, sizeof buf, "%s/%s.gssapi", pw->pw_dir,
 632                     _PATH_SSH_USER_CONFFILE);
 633                 if (r > 0 && (size_t)r < sizeof(buf))
 634                         (void)read_config_file(buf, host, &options, 1);
 635 #ifdef GSI
 636                 r = snprintf(buf, sizeof buf, "%s/%s.gsi", pw->pw_dir,
 637                     _PATH_SSH_USER_CONFFILE);
 638                 if (r > 0 && (size_t)r < sizeof(buf))
 639                         (void)read_config_file(buf, host, &options, 1);
 640 #endif
 641 #if defined(KRB5)
 642                 r = snprintf(buf, sizeof buf, "%s/%s.krb", pw->pw_dir,
 643                     _PATH_SSH_USER_CONFFILE);
 644                 if (r > 0 && (size_t)r < sizeof(buf))
 645                         (void)read_config_file(buf, host, &options, 1);
 646 #endif
 647 #endif
 648                 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
 649                     _PATH_SSH_USER_CONFFILE);
 650                 if (r > 0 && (size_t)r < sizeof(buf))
 651                         (void)read_config_file(buf, host, &options, 1);
 652
 653                 /* Read systemwide configuration file after use config. */
 654                 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
 655                     &options, 0);
 656         }
 657
 658         /* Fill configuration defaults. */
 659         fill_default_options(&options);
 660
 661         channel_set_af(options.address_family);
 662
 663         /* reinit */
 664         log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
 665
 666         seed_rng();
 667
 668         if (options.user == NULL) {
 669                 options.user = xstrdup(pw->pw_name);
 670                 options.implicit = 1;
 671         }
 672         else options.implicit = 0;
 673
 674         /* Get default port if port has not been set. */
 675         if (options.port == 0) {
 676                 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
 677                 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
 678         }
 679
 680         if (options.local_command != NULL) {
 681                 char thishost[NI_MAXHOST];
 682
 683                 if (gethostname(thishost, sizeof(thishost)) == -1)
 684                         fatal("gethostname: %s", strerror(errno));
 685                 snprintf(buf, sizeof(buf), "%d", options.port);
 686                 debug3("expanding LocalCommand: %s", options.local_command);
 687                 cp = options.local_command;
 688                 options.local_command = percent_expand(cp, "d", pw->pw_dir,
 689                     "h", options.hostname? options.hostname : host,
 690                     "l", thishost, "n", host, "r", options.user, "p", buf,
 691                     "u", pw->pw_name, (char *)NULL);
 692                 debug3("expanded LocalCommand: %s", options.local_command);
 693                 xfree(cp);
 694         }
 695
 696         if (options.hostname != NULL)
 697                 host = options.hostname;
 698
 699         /* force lowercase for hostkey matching */
 700         if (options.host_key_alias != NULL) {
 701                 for (p = options.host_key_alias; *p; p++)
 702                         if (isupper(*p))
 703                                 *p = (char)tolower(*p);
 704         }
 705
 706         if (options.proxy_command != NULL &&
 707             strcmp(options.proxy_command, "none") == 0) {
 708                 xfree(options.proxy_command);
 709                 options.proxy_command = NULL;
 710         }
 711         if (options.control_path != NULL &&
 712             strcmp(options.control_path, "none") == 0) {
 713                 xfree(options.control_path);
 714                 options.control_path = NULL;
 715         }
 716
 717         if (options.control_path != NULL) {
 718                 char thishost[NI_MAXHOST];
 719
 720                 if (gethostname(thishost, sizeof(thishost)) == -1)
 721                         fatal("gethostname: %s", strerror(errno));
 722                 snprintf(buf, sizeof(buf), "%d", options.port);
 723                 cp = tilde_expand_filename(options.control_path,
 724                     original_real_uid);
 725                 xfree(options.control_path);
 726                 options.control_path = percent_expand(cp, "p", buf, "h", host,
 727                     "r", options.user, "l", thishost, (char *)NULL);
 728                 xfree(cp);
 729         }
 730         if (muxclient_command != 0 && options.control_path == NULL)
 731                 fatal("No ControlPath specified for \"-O\" command");
 732         if (options.control_path != NULL)
 733                 muxclient(options.control_path);
 734
 735         timeout_ms = options.connection_timeout * 1000;
 736
 737         /* Open a connection to the remote host. */
 738         if (ssh_connect(host, &hostaddr, options.port,
 739             options.address_family, options.connection_attempts, &timeout_ms,
 740             options.tcp_keep_alive,
 741 #ifdef HAVE_CYGWIN
 742             options.use_privileged_port,
 743 #else
 744             original_effective_uid == 0 && options.use_privileged_port,
 745 #endif
 746             options.proxy_command) != 0)
 747                 exit(255);
 748
 749         if (timeout_ms > 0)
 750                 debug3("timeout: %d ms remain after connect", timeout_ms);
 751
 752         /*
 753          * If we successfully made the connection, load the host private key
 754          * in case we will need it later for combined rsa-rhosts
 755          * authentication. This must be done before releasing extra
 756          * privileges, because the file is only readable by root.
 757          * If we cannot access the private keys, load the public keys
 758          * instead and try to execute the ssh-keysign helper instead.
 759          */
 760         sensitive_data.nkeys = 0;
 761         sensitive_data.keys = NULL;
 762         sensitive_data.external_keysign = 0;
 763         if (options.rhosts_rsa_authentication ||
 764             options.hostbased_authentication) {
 765                 sensitive_data.nkeys = 3;
 766                 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
 767                     sizeof(Key));
 768
 769                 PRIV_START;
 770                 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
 771                     _PATH_HOST_KEY_FILE, "", NULL, NULL);
 772                 sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
 773                     _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
 774                 sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
 775                     _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
 776                 PRIV_END;
 777
 778                 if (options.hostbased_authentication == 1 &&
 779                     sensitive_data.keys[0] == NULL &&
 780                     sensitive_data.keys[1] == NULL &&
 781                     sensitive_data.keys[2] == NULL) {
 782                         sensitive_data.keys[1] = key_load_public(
 783                             _PATH_HOST_DSA_KEY_FILE, NULL);
 784                         sensitive_data.keys[2] = key_load_public(
 785                             _PATH_HOST_RSA_KEY_FILE, NULL);
 786                         sensitive_data.external_keysign = 1;
 787                 }
 788         }
 789         /*
 790          * Get rid of any extra privileges that we may have.  We will no
 791          * longer need them.  Also, extra privileges could make it very hard
 792          * to read identity files and other non-world-readable files from the
 793          * user's home directory if it happens to be on a NFS volume where
 794          * root is mapped to nobody.
 795          */
 796         if (original_effective_uid == 0) {
 797                 PRIV_START;
 798                 permanently_set_uid(pw);
 799         }
 800
 801         /*
 802          * Now that we are back to our own permissions, create ~/.ssh
 803          * directory if it doesn't already exist.
 804          */
 805         r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir,
 806             strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
 807         if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0)
 808                 if (mkdir(buf, 0700) < 0)
 809                         error("Could not create directory '%.200s'.", buf);
 810
 811         /* load options.identity_files */
 812         load_public_identity_files();
 813
 814         /* Expand ~ in known host file names. */
 815         /* XXX mem-leaks: */
 816         options.system_hostfile =
 817             tilde_expand_filename(options.system_hostfile, original_real_uid);
 818         options.user_hostfile =
 819             tilde_expand_filename(options.user_hostfile, original_real_uid);
 820         options.system_hostfile2 =
 821             tilde_expand_filename(options.system_hostfile2, original_real_uid);
 822         options.user_hostfile2 =
 823             tilde_expand_filename(options.user_hostfile2, original_real_uid);
 824
 825         signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
 826
 827         /* Log into the remote system.  Never returns if the login fails. */
 828         ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
 829             pw, timeout_ms);
 830
 831         /* We no longer need the private host keys.  Clear them now. */
 832         if (sensitive_data.nkeys != 0) {
 833                 for (i = 0; i < sensitive_data.nkeys; i++) {
 834                         if (sensitive_data.keys[i] != NULL) {
 835                                 /* Destroys contents safely */
 836                                 debug3("clear hostkey %d", i);
 837                                 key_free(sensitive_data.keys[i]);
 838                                 sensitive_data.keys[i] = NULL;
 839                         }
 840                 }
 841                 xfree(sensitive_data.keys);
 842         }
 843         for (i = 0; i < options.num_identity_files; i++) {
 844                 if (options.identity_files[i]) {
 845                         xfree(options.identity_files[i]);
 846                         options.identity_files[i] = NULL;
 847                 }
 848                 if (options.identity_keys[i]) {
 849                         key_free(options.identity_keys[i]);
 850                         options.identity_keys[i] = NULL;
 851                 }
 852         }
 853
 854         exit_status = compat20 ? ssh_session2() : ssh_session();
 855         packet_close();
 856
 857         if (options.control_path != NULL && muxserver_sock != -1)
 858                 unlink(options.control_path);
 859
 860         /*
 861          * Send SIGHUP to proxy command if used. We don't wait() in
 862          * case it hangs and instead rely on init to reap the child
 863          */
 864         if (proxy_command_pid > 1)
 865                 kill(proxy_command_pid, SIGHUP);
 866
 867         return exit_status;
 868 }
 869
 870 /* Callback for remote forward global requests */
 871 static void
 872 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
 873 {
 874         Forward *rfwd = (Forward *)ctxt;
 875
 876         /* XXX verbose() on failure? */
 877         debug("remote forward %s for: listen %d, connect %s:%d",
 878             type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
 879             rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
 880         if (type == SSH2_MSG_REQUEST_SUCCESS && rfwd->listen_port == 0) {
 881                 logit("Allocated port %u for remote forward to %s:%d",
 882                         packet_get_int(),
 883                         rfwd->connect_host, rfwd->connect_port);
 884         }
 885
 886         if (type == SSH2_MSG_REQUEST_FAILURE) {
 887                 if (options.exit_on_forward_failure)
 888                         fatal("Error: remote port forwarding failed for "
 889                             "listen port %d", rfwd->listen_port);
 890                 else
 891                         logit("Warning: remote port forwarding failed for "
 892                             "listen port %d", rfwd->listen_port);
 893         }
 894         if (++remote_forward_confirms_received == options.num_remote_forwards) {
 895                 debug("All remote forwarding requests processed");
 896                 if (fork_after_authentication_flag) {
 897                         fork_after_authentication_flag = 0;
 898                         if (daemon(1, 1) < 0)
 899                                 fatal("daemon() failed: %.200s",
 900                                     strerror(errno));
 901                 }
 902         }
 903 }
 904
 905 static void
 906 ssh_init_forwarding(void)
 907 {
 908         int success = 0;
 909         int i;
 910
 911         /* Initiate local TCP/IP port forwardings. */
 912         for (i = 0; i < options.num_local_forwards; i++) {
 913                 debug("Local connections to %.200s:%d forwarded to remote "
 914                     "address %.200s:%d",
 915                     (options.local_forwards[i].listen_host == NULL) ?
 916                     (options.gateway_ports ? "*" : "LOCALHOST") :
 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                 success += channel_setup_local_fwd_listener(
 922                     options.local_forwards[i].listen_host,
 923                     options.local_forwards[i].listen_port,
 924                     options.local_forwards[i].connect_host,
 925                     options.local_forwards[i].connect_port,
 926                     options.gateway_ports);
 927         }
 928         if (i > 0 && success != i && options.exit_on_forward_failure)
 929                 fatal("Could not request local forwarding.");
 930         if (i > 0 && success == 0)
 931                 error("Could not request local forwarding.");
 932
 933         /* Initiate remote TCP/IP port forwardings. */
 934         for (i = 0; i < options.num_remote_forwards; i++) {
 935                 debug("Remote connections from %.200s:%d forwarded to "
 936                     "local address %.200s:%d",
 937                     (options.remote_forwards[i].listen_host == NULL) ?
 938                     "LOCALHOST" : 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);
 942                 if (channel_request_remote_forwarding(
 943                     options.remote_forwards[i].listen_host,
 944                     options.remote_forwards[i].listen_port,
 945                     options.remote_forwards[i].connect_host,
 946                     options.remote_forwards[i].connect_port) < 0) {
 947                         if (options.exit_on_forward_failure)
 948                                 fatal("Could not request remote forwarding.");
 949                         else
 950                                 logit("Warning: Could not request remote "
 951                                     "forwarding.");
 952                 }
 953                 client_register_global_confirm(ssh_confirm_remote_forward,
 954                     &options.remote_forwards[i]);
 955         }
 956
 957         /* Initiate tunnel forwarding. */
 958         if (options.tun_open != SSH_TUNMODE_NO) {
 959                 if (client_request_tun_fwd(options.tun_open,
 960                     options.tun_local, options.tun_remote) == -1) {
 961                         if (options.exit_on_forward_failure)
 962                                 fatal("Could not request tunnel forwarding.");
 963                         else
 964                                 error("Could not request tunnel forwarding.");
 965                 }
 966         }
 967 }
 968
 969 static void
 970 check_agent_present(void)
 971 {
 972         if (options.forward_agent) {
 973                 /* Clear agent forwarding if we don't have an agent. */
 974                 if (!ssh_agent_present())
 975                         options.forward_agent = 0;
 976         }
 977 }
 978
 979 static int
 980 ssh_session(void)
 981 {
 982         int type;
 983         int interactive = 0;
 984         int have_tty = 0;
 985         struct winsize ws;
 986         char *cp;
 987         const char *display;
 988
 989         /* Enable compression if requested. */
 990         if (options.compression) {
 991                 debug("Requesting compression at level %d.",
 992                     options.compression_level);
 993
 994                 if (options.compression_level < 1 ||
 995                     options.compression_level > 9)
 996                         fatal("Compression level must be from 1 (fast) to "
 997                             "9 (slow, best).");
 998
 999                 /* Send the request. */
1000                 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
1001                 packet_put_int(options.compression_level);
1002                 packet_send();
1003                 packet_write_wait();
1004                 type = packet_read();
1005                 if (type == SSH_SMSG_SUCCESS)
1006                         packet_start_compression(options.compression_level);
1007                 else if (type == SSH_SMSG_FAILURE)
1008                         logit("Warning: Remote host refused compression.");
1009                 else
1010                         packet_disconnect("Protocol error waiting for "
1011                             "compression response.");
1012         }
1013         /* Allocate a pseudo tty if appropriate. */
1014         if (tty_flag) {
1015                 debug("Requesting pty.");
1016
1017                 /* Start the packet. */
1018                 packet_start(SSH_CMSG_REQUEST_PTY);
1019
1020                 /* Store TERM in the packet.  There is no limit on the
1021                    length of the string. */
1022                 cp = getenv("TERM");
1023                 if (!cp)
1024                         cp = "";
1025                 packet_put_cstring(cp);
1026
1027                 /* Store window size in the packet. */
1028                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
1029                         memset(&ws, 0, sizeof(ws));
1030                 packet_put_int((u_int)ws.ws_row);
1031                 packet_put_int((u_int)ws.ws_col);
1032                 packet_put_int((u_int)ws.ws_xpixel);
1033                 packet_put_int((u_int)ws.ws_ypixel);
1034
1035                 /* Store tty modes in the packet. */
1036                 tty_make_modes(fileno(stdin), NULL);
1037
1038                 /* Send the packet, and wait for it to leave. */
1039                 packet_send();
1040                 packet_write_wait();
1041
1042                 /* Read response from the server. */
1043                 type = packet_read();
1044                 if (type == SSH_SMSG_SUCCESS) {
1045                         interactive = 1;
1046                         have_tty = 1;
1047                 } else if (type == SSH_SMSG_FAILURE)
1048                         logit("Warning: Remote host failed or refused to "
1049                             "allocate a pseudo tty.");
1050                 else
1051                         packet_disconnect("Protocol error waiting for pty "
1052                             "request response.");
1053         }
1054         /* Request X11 forwarding if enabled and DISPLAY is set. */
1055         display = getenv("DISPLAY");
1056         if (options.forward_x11 && display != NULL) {
1057                 char *proto, *data;
1058                 /* Get reasonable local authentication information. */
1059                 client_x11_get_proto(display, options.xauth_location,
1060                     options.forward_x11_trusted, &proto, &data);
1061                 /* Request forwarding with authentication spoofing. */
1062                 debug("Requesting X11 forwarding with authentication "
1063                     "spoofing.");
1064                 x11_request_forwarding_with_spoofing(0, display, proto, data);
1065
1066                 /* Read response from the server. */
1067                 type = packet_read();
1068                 if (type == SSH_SMSG_SUCCESS) {
1069                         interactive = 1;
1070                 } else if (type == SSH_SMSG_FAILURE) {
1071                         logit("Warning: Remote host denied X11 forwarding.");
1072                 } else {
1073                         packet_disconnect("Protocol error waiting for X11 "
1074                             "forwarding");
1075                 }
1076         }
1077         /* Tell the packet module whether this is an interactive session. */
1078         packet_set_interactive(interactive);
1079
1080         /* Request authentication agent forwarding if appropriate. */
1081         check_agent_present();
1082
1083         if (options.forward_agent) {
1084                 debug("Requesting authentication agent forwarding.");
1085                 auth_request_forwarding();
1086
1087                 /* Read response from the server. */
1088                 type = packet_read();
1089                 packet_check_eom();
1090                 if (type != SSH_SMSG_SUCCESS)
1091                         logit("Warning: Remote host denied authentication agent forwarding.");
1092         }
1093
1094         /* Initiate port forwardings. */
1095         ssh_init_forwarding();
1096
1097         /* Execute a local command */
1098         if (options.local_command != NULL &&
1099             options.permit_local_command)
1100                 ssh_local_cmd(options.local_command);
1101
1102         /*
1103          * If requested and we are not interested in replies to remote
1104          * forwarding requests, then let ssh continue in the background.
1105          */
1106         if (fork_after_authentication_flag &&
1107             (!options.exit_on_forward_failure ||
1108             options.num_remote_forwards == 0)) {
1109                 fork_after_authentication_flag = 0;
1110                 if (daemon(1, 1) < 0)
1111                         fatal("daemon() failed: %.200s", strerror(errno));
1112         }
1113
1114         /*
1115          * If a command was specified on the command line, execute the
1116          * command now. Otherwise request the server to start a shell.
1117          */
1118         if (buffer_len(&command) > 0) {
1119                 int len = buffer_len(&command);
1120                 if (len > 900)
1121                         len = 900;
1122                 debug("Sending command: %.*s", len,
1123                     (u_char *)buffer_ptr(&command));
1124                 packet_start(SSH_CMSG_EXEC_CMD);
1125                 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1126                 packet_send();
1127                 packet_write_wait();
1128         } else {
1129                 debug("Requesting shell.");
1130                 packet_start(SSH_CMSG_EXEC_SHELL);
1131                 packet_send();
1132                 packet_write_wait();
1133         }
1134
1135         /* Enter the interactive session. */
1136         return client_loop(have_tty, tty_flag ?
1137             options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1138 }
1139
1140 /* request pty/x11/agent/tcpfwd/shell for channel */
1141 static void
1142 ssh_session2_setup(int id, void *arg)
1143 {
1144         extern char **environ;
1145         const char *display;
1146         int interactive = tty_flag;
1147
1148         display = getenv("DISPLAY");
1149         if (options.forward_x11 && display != NULL) {
1150                 char *proto, *data;
1151                 /* Get reasonable local authentication information. */
1152                 client_x11_get_proto(display, options.xauth_location,
1153                     options.forward_x11_trusted, &proto, &data);
1154                 /* Request forwarding with authentication spoofing. */
1155                 debug("Requesting X11 forwarding with authentication "
1156                     "spoofing.");
1157                 x11_request_forwarding_with_spoofing(id, display, proto, data);
1158                 interactive = 1;
1159                 /* XXX wait for reply */
1160         }
1161
1162         check_agent_present();
1163         if (options.forward_agent) {
1164                 debug("Requesting authentication agent forwarding.");
1165                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1166                 packet_send();
1167         }
1168
1169         client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1170             NULL, fileno(stdin), &command, environ);
1171
1172         packet_set_interactive(interactive);
1173 }
1174
1175 /* open new channel for a session */
1176 static int
1177 ssh_session2_open(void)
1178 {
1179         Channel *c;
1180         int window, packetmax, in, out, err;
1181         int sock;
1182         int socksize;
1183         int socksizelen = sizeof(int);
1184
1185         if (stdin_null_flag) {
1186                 in = open(_PATH_DEVNULL, O_RDONLY);
1187         } else {
1188                 in = dup(STDIN_FILENO);
1189         }
1190         out = dup(STDOUT_FILENO);
1191         err = dup(STDERR_FILENO);
1192
1193         if (in < 0 || out < 0 || err < 0)
1194                 fatal("dup() in/out/err failed");
1195
1196         /* enable nonblocking unless tty */
1197         if (!isatty(in))
1198                 set_nonblock(in);
1199         if (!isatty(out))
1200                 set_nonblock(out);
1201         if (!isatty(err))
1202                 set_nonblock(err);
1203
1204         /* we need to check to see if what they want to do about buffer */
1205         /* sizes here. In a hpn to nonhpn connection we want to limit */
1206         /* the window size to something reasonable in case the far side */
1207         /* has the large window bug. In hpn to hpn connection we want to */
1208         /* use the max window size but allow the user to override it */
1209         /* lastly if they disabled hpn then use the ssh std window size */
1210
1211         /* so why don't we just do a getsockopt() here and set the */
1212         /* ssh window to that? In the case of a autotuning receive */
1213         /* window the window would get stuck at the initial buffer */
1214         /* size generally less than 96k. Therefore we need to set the */
1215         /* maximum ssh window size to the maximum hpn buffer size */
1216         /* unless the user has specifically set the tcprcvbufpoll */
1217         /* to no. In which case we *can* just set the window to the */
1218         /* minimum of the hpn buffer size and tcp receive buffer size */
1219
1220         if (tty_flag)
1221                 options.hpn_buffer_size = CHAN_SES_WINDOW_DEFAULT;
1222         else
1223                 options.hpn_buffer_size = 2*1024*1024;
1224
1225         if (datafellows & SSH_BUG_LARGEWINDOW)
1226         {
1227                 debug("HPN to Non-HPN Connection");
1228         }
1229         else
1230         {
1231                 if (options.tcp_rcv_buf_poll <= 0)
1232                 {
1233                         sock = socket(AF_INET, SOCK_STREAM, 0);
1234                         getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1235                                    &socksize, &socksizelen);
1236                         close(sock);
1237                         debug("socksize %d", socksize);
1238                         options.hpn_buffer_size = socksize;
1239                         debug ("HPNBufferSize set to TCP RWIN: %d", options.hpn_buffer_size);
1240                 }
1241                 else
1242                 {
1243                         if (options.tcp_rcv_buf > 0)
1244                         {
1245                                 /*create a socket but don't connect it */
1246                                 /* we use that the get the rcv socket size */
1247                                 sock = socket(AF_INET, SOCK_STREAM, 0);
1248                                 /* if they are using the tcp_rcv_buf option */
1249                                 /* attempt to set the buffer size to that */
1250                                 if (options.tcp_rcv_buf)
1251                                         setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void *)&options.tcp_rcv_buf,
1252                                                    sizeof(options.tcp_rcv_buf));
1253                                 getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1254                                            &socksize, &socksizelen);
1255                                 close(sock);
1256                                 debug("socksize %d", socksize);
1257                                 options.hpn_buffer_size = socksize;
1258                                 debug ("HPNBufferSize set to user TCPRcvBuf: %d", options.hpn_buffer_size);
1259                         }
1260                 }
1261
1262         }
1263
1264         debug("Final hpn_buffer_size = %d", options.hpn_buffer_size);
1265
1266         window = options.hpn_buffer_size;
1267
1268         channel_set_hpn(options.hpn_disabled, options.hpn_buffer_size);
1269
1270         packetmax = CHAN_SES_PACKET_DEFAULT;
1271         if (tty_flag) {
1272                 window = 4*CHAN_SES_PACKET_DEFAULT;
1273                 window >>= 1;
1274                 packetmax >>= 1;
1275         }
1276         c = channel_new(
1277             "session", SSH_CHANNEL_OPENING, in, out, err,
1278             window, packetmax, CHAN_EXTENDED_WRITE,
1279             "client-session", /*nonblock*/0);
1280         if ((options.tcp_rcv_buf_poll > 0) && (!options.hpn_disabled)) {
1281                 c->dynamic_window = 1;
1282                 debug ("Enabled Dynamic Window Scaling\n");
1283         }
1284         debug3("ssh_session2_open: channel_new: %d", c->self);
1285
1286         channel_send_open(c->self);
1287         if (!no_shell_flag)
1288                 channel_register_open_confirm(c->self,
1289                     ssh_session2_setup, NULL);
1290
1291         return c->self;
1292 }
1293
1294 static int
1295 ssh_session2(void)
1296 {
1297         int id = -1;
1298
1299         /* XXX should be pre-session */
1300         ssh_init_forwarding();
1301
1302         if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1303                 id = ssh_session2_open();
1304
1305         /* If we don't expect to open a new session, then disallow it */
1306         if (options.control_master == SSHCTL_MASTER_NO &&
1307             (datafellows & SSH_NEW_OPENSSH)) {
1308                 debug("Requesting no-more-sessions@openssh.com");
1309                 packet_start(SSH2_MSG_GLOBAL_REQUEST);
1310                 packet_put_cstring("no-more-sessions@openssh.com");
1311                 packet_put_char(0);
1312                 packet_send();
1313         }
1314
1315         /* Execute a local command */
1316         if (options.local_command != NULL &&
1317             options.permit_local_command)
1318                 ssh_local_cmd(options.local_command);
1319
1320         /* Start listening for multiplex clients */
1321         muxserver_listen();
1322
1323         /* If requested, let ssh continue in the background. */
1324         if (fork_after_authentication_flag) {
1325                 fork_after_authentication_flag = 0;
1326                 if (daemon(1, 1) < 0)
1327                         fatal("daemon() failed: %.200s", strerror(errno));
1328         }
1329
1330         return client_loop(tty_flag, tty_flag ?
1331             options.escape_char : SSH_ESCAPECHAR_NONE, id);
1332 }
1333
1334 static void
1335 load_public_identity_files(void)
1336 {
1337         char *filename, *cp, thishost[NI_MAXHOST];
1338         char *pwdir = NULL, *pwname = NULL;
1339         int i = 0;
1340         Key *public;
1341         struct passwd *pw;
1342 #ifdef SMARTCARD
1343         Key **keys;
1344
1345         if (options.smartcard_device != NULL &&
1346             options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1347             (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL) {
1348                 int count = 0;
1349                 for (i = 0; keys[i] != NULL; i++) {
1350                         count++;
1351                         memmove(&options.identity_files[1],
1352                             &options.identity_files[0],
1353                             sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1));
1354                         memmove(&options.identity_keys[1],
1355                             &options.identity_keys[0],
1356                             sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1));
1357                         options.num_identity_files++;
1358                         options.identity_keys[0] = keys[i];
1359                         options.identity_files[0] = sc_get_key_label(keys[i]);
1360                 }
1361                 if (options.num_identity_files > SSH_MAX_IDENTITY_FILES)
1362                         options.num_identity_files = SSH_MAX_IDENTITY_FILES;
1363                 i = count;
1364                 xfree(keys);
1365         }
1366 #endif /* SMARTCARD */
1367         if ((pw = getpwuid(original_real_uid)) == NULL)
1368                 fatal("load_public_identity_files: getpwuid failed");
1369         pwname = xstrdup(pw->pw_name);
1370         pwdir = xstrdup(pw->pw_dir);
1371         if (gethostname(thishost, sizeof(thishost)) == -1)
1372                 fatal("load_public_identity_files: gethostname: %s",
1373                     strerror(errno));
1374         for (; i < options.num_identity_files; i++) {
1375                 cp = tilde_expand_filename(options.identity_files[i],
1376                     original_real_uid);
1377                 filename = percent_expand(cp, "d", pwdir,
1378                     "u", pwname, "l", thishost, "h", host,
1379                     "r", options.user, (char *)NULL);
1380                 xfree(cp);
1381                 public = key_load_public(filename, NULL);
1382                 debug("identity file %s type %d", filename,
1383                     public ? public->type : -1);
1384                 xfree(options.identity_files[i]);
1385                 options.identity_files[i] = filename;
1386                 options.identity_keys[i] = public;
1387         }
1388         bzero(pwname, strlen(pwname));
1389         xfree(pwname);
1390         bzero(pwdir, strlen(pwdir));
1391         xfree(pwdir);
1392 }