openssh/ssh.c

   1 /* $OpenBSD: ssh.c,v 1.318 2008/07/02 13:47:39 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 [-1246AaCfgKkMNnqsTtVvXxY] [-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;
 207         char *p, *cp, *line, buf[256];
 208         struct stat st;
 209         struct passwd *pw;
 210         int dummy, timeout_ms;
 211         extern int optind, optreset;
 212         extern char *optarg;
 213         struct servent *sp;
 214         Forward fwd;
 215
 216         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 217         sanitise_stdfd();
 218
 219         __progname = ssh_get_progname(av[0]);
 220         init_rng();
 221
 222         /*
 223          * Save the original real uid.  It will be needed later (uid-swapping
 224          * may clobber the real uid).
 225          */
 226         original_real_uid = getuid();
 227         original_effective_uid = geteuid();
 228
 229         /*
 230          * Use uid-swapping to give up root privileges for the duration of
 231          * option processing.  We will re-instantiate the rights when we are
 232          * ready to create the privileged port, and will permanently drop
 233          * them when the port has been created (actually, when the connection
 234          * has been made, as we may need to create the port several times).
 235          */
 236         PRIV_END;
 237
 238 #ifdef HAVE_SETRLIMIT
 239         /* If we are installed setuid root be careful to not drop core. */
 240         if (original_real_uid != original_effective_uid) {
 241                 struct rlimit rlim;
 242                 rlim.rlim_cur = rlim.rlim_max = 0;
 243                 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
 244                         fatal("setrlimit failed: %.100s", strerror(errno));
 245         }
 246 #endif
 247         /* Get user data. */
 248         pw = getpwuid(original_real_uid);
 249         if (!pw) {
 250                 logit("You don't exist, go away!");
 251                 exit(255);
 252         }
 253         /* Take a copy of the returned structure. */
 254         pw = pwcopy(pw);
 255
 256         /*
 257          * Set our umask to something reasonable, as some files are created
 258          * with the default umask.  This will make them world-readable but
 259          * writable only by the owner, which is ok for all files for which we
 260          * don't set the modes explicitly.
 261          */
 262         umask(022);
 263
 264         /*
 265          * Initialize option structure to indicate that no values have been
 266          * set.
 267          */
 268         initialize_options(&options);
 269
 270         /* Parse command-line arguments. */
 271         host = NULL;
 272
 273  again:
 274         while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
 275             "ACD:F:I:KL:MNO:PR:S:TVw:XY")) != -1) {
 276                 switch (opt) {
 277                 case '1':
 278                         options.protocol = SSH_PROTO_1;
 279                         break;
 280                 case '2':
 281                         options.protocol = SSH_PROTO_2;
 282                         break;
 283                 case '4':
 284                         options.address_family = AF_INET;
 285                         break;
 286                 case '6':
 287                         options.address_family = AF_INET6;
 288                         break;
 289                 case 'n':
 290                         stdin_null_flag = 1;
 291                         break;
 292                 case 'f':
 293                         fork_after_authentication_flag = 1;
 294                         stdin_null_flag = 1;
 295                         break;
 296                 case 'x':
 297                         options.forward_x11 = 0;
 298                         break;
 299                 case 'X':
 300                         options.forward_x11 = 1;
 301                         break;
 302                 case 'Y':
 303                         options.forward_x11 = 1;
 304                         options.forward_x11_trusted = 1;
 305                         break;
 306                 case 'g':
 307                         options.gateway_ports = 1;
 308                         break;
 309                 case 'O':
 310                         if (strcmp(optarg, "check") == 0)
 311                                 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
 312                         else if (strcmp(optarg, "exit") == 0)
 313                                 muxclient_command = SSHMUX_COMMAND_TERMINATE;
 314                         else
 315                                 fatal("Invalid multiplex command.");
 316                         break;
 317                 case 'P':       /* deprecated */
 318                         options.use_privileged_port = 0;
 319                         break;
 320                 case 'a':
 321                         options.forward_agent = 0;
 322                         break;
 323                 case 'A':
 324                         options.forward_agent = 1;
 325                         break;
 326                 case 'k':
 327                         options.gss_deleg_creds = 0;
 328                         break;
 329                 case 'K':
 330                         options.gss_authentication = 1;
 331                         options.gss_deleg_creds = 1;
 332                         break;
 333                 case 'i':
 334                         if (stat(optarg, &st) < 0) {
 335                                 fprintf(stderr, "Warning: Identity file %s "
 336                                     "not accessible: %s.\n", optarg,
 337                                     strerror(errno));
 338                                 break;
 339                         }
 340                         if (options.num_identity_files >=
 341                             SSH_MAX_IDENTITY_FILES)
 342                                 fatal("Too many identity files specified "
 343                                     "(max %d)", SSH_MAX_IDENTITY_FILES);
 344                         options.identity_files[options.num_identity_files++] =
 345                             xstrdup(optarg);
 346                         break;
 347                 case 'I':
 348 #ifdef SMARTCARD
 349                         options.smartcard_device = xstrdup(optarg);
 350 #else
 351                         fprintf(stderr, "no support for smartcards.\n");
 352 #endif
 353                         break;
 354                 case 't':
 355                         if (tty_flag)
 356                                 force_tty_flag = 1;
 357                         tty_flag = 1;
 358                         break;
 359                 case 'v':
 360                         if (debug_flag == 0) {
 361                                 debug_flag = 1;
 362                                 options.log_level = SYSLOG_LEVEL_DEBUG1;
 363                         } else {
 364                                 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
 365                                         options.log_level++;
 366                                 break;
 367                         }
 368                         /* FALLTHROUGH */
 369                 case 'V':
 370                         fprintf(stderr, "%s, %s\n",
 371                             SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
 372                         if (opt == 'V')
 373                                 exit(0);
 374                         break;
 375                 case 'w':
 376                         if (options.tun_open == -1)
 377                                 options.tun_open = SSH_TUNMODE_DEFAULT;
 378                         options.tun_local = a2tun(optarg, &options.tun_remote);
 379                         if (options.tun_local == SSH_TUNID_ERR) {
 380                                 fprintf(stderr,
 381                                     "Bad tun device '%s'\n", optarg);
 382                                 exit(255);
 383                         }
 384                         break;
 385                 case 'q':
 386                         options.log_level = SYSLOG_LEVEL_QUIET;
 387                         break;
 388                 case 'e':
 389                         if (optarg[0] == '^' && optarg[2] == 0 &&
 390                             (u_char) optarg[1] >= 64 &&
 391                             (u_char) optarg[1] < 128)
 392                                 options.escape_char = (u_char) optarg[1] & 31;
 393                         else if (strlen(optarg) == 1)
 394                                 options.escape_char = (u_char) optarg[0];
 395                         else if (strcmp(optarg, "none") == 0)
 396                                 options.escape_char = SSH_ESCAPECHAR_NONE;
 397                         else {
 398                                 fprintf(stderr, "Bad escape character '%s'.\n",
 399                                     optarg);
 400                                 exit(255);
 401                         }
 402                         break;
 403                 case 'c':
 404                         if (ciphers_valid(optarg)) {
 405                                 /* SSH2 only */
 406                                 options.ciphers = xstrdup(optarg);
 407                                 options.cipher = SSH_CIPHER_INVALID;
 408                         } else {
 409                                 /* SSH1 only */
 410                                 options.cipher = cipher_number(optarg);
 411                                 if (options.cipher == -1) {
 412                                         fprintf(stderr,
 413                                             "Unknown cipher type '%s'\n",
 414                                             optarg);
 415                                         exit(255);
 416                                 }
 417                                 if (options.cipher == SSH_CIPHER_3DES)
 418                                         options.ciphers = "3des-cbc";
 419                                 else if (options.cipher == SSH_CIPHER_BLOWFISH)
 420                                         options.ciphers = "blowfish-cbc";
 421                                 else
 422                                         options.ciphers = (char *)-1;
 423                         }
 424                         break;
 425                 case 'm':
 426                         if (mac_valid(optarg))
 427                                 options.macs = xstrdup(optarg);
 428                         else {
 429                                 fprintf(stderr, "Unknown mac type '%s'\n",
 430                                     optarg);
 431                                 exit(255);
 432                         }
 433                         break;
 434                 case 'M':
 435                         if (options.control_master == SSHCTL_MASTER_YES)
 436                                 options.control_master = SSHCTL_MASTER_ASK;
 437                         else
 438                                 options.control_master = SSHCTL_MASTER_YES;
 439                         break;
 440                 case 'p':
 441                         options.port = a2port(optarg);
 442                         if (options.port == 0) {
 443                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 444                                 exit(255);
 445                         }
 446                         break;
 447                 case 'l':
 448                         options.user = optarg;
 449                         break;
 450
 451                 case 'L':
 452                         if (parse_forward(&fwd, optarg))
 453                                 add_local_forward(&options, &fwd);
 454                         else {
 455                                 fprintf(stderr,
 456                                     "Bad local forwarding specification '%s'\n",
 457                                     optarg);
 458                                 exit(255);
 459                         }
 460                         break;
 461
 462                 case 'R':
 463                         if (parse_forward(&fwd, optarg)) {
 464                                 add_remote_forward(&options, &fwd);
 465                         } else {
 466                                 fprintf(stderr,
 467                                     "Bad remote forwarding specification "
 468                                     "'%s'\n", optarg);
 469                                 exit(255);
 470                         }
 471                         break;
 472
 473                 case 'D':
 474                         cp = p = xstrdup(optarg);
 475                         memset(&fwd, '\0', sizeof(fwd));
 476                         fwd.connect_host = "socks";
 477                         if ((fwd.listen_host = hpdelim(&cp)) == NULL) {
 478                                 fprintf(stderr, "Bad dynamic forwarding "
 479                                     "specification '%.100s'\n", optarg);
 480                                 exit(255);
 481                         }
 482                         if (cp != NULL) {
 483                                 fwd.listen_port = a2port(cp);
 484                                 fwd.listen_host =
 485                                     cleanhostname(fwd.listen_host);
 486                         } else {
 487                                 fwd.listen_port = a2port(fwd.listen_host);
 488                                 fwd.listen_host = NULL;
 489                         }
 490
 491                         if (fwd.listen_port == 0) {
 492                                 fprintf(stderr, "Bad dynamic port '%s'\n",
 493                                     optarg);
 494                                 exit(255);
 495                         }
 496                         add_local_forward(&options, &fwd);
 497                         xfree(p);
 498                         break;
 499
 500                 case 'C':
 501                         options.compression = 1;
 502                         break;
 503                 case 'N':
 504                         no_shell_flag = 1;
 505                         no_tty_flag = 1;
 506                         break;
 507                 case 'T':
 508                         no_tty_flag = 1;
 509                         /* ensure that the user doesn't try to backdoor a */
 510                         /* null cipher switch on an interactive session */
 511                         /* so explicitly disable it no matter what */
 512                         options.none_switch=0;
 513                         break;
 514                 case 'o':
 515                         dummy = 1;
 516                         line = xstrdup(optarg);
 517                         if (process_config_line(&options, host ? host : "",
 518                             line, "command-line", 0, &dummy) != 0)
 519                                 exit(255);
 520                         xfree(line);
 521                         break;
 522                 case 's':
 523                         subsystem_flag = 1;
 524                         break;
 525                 case 'S':
 526                         if (options.control_path != NULL)
 527                                 free(options.control_path);
 528                         options.control_path = xstrdup(optarg);
 529                         break;
 530                 case 'b':
 531                         options.bind_address = optarg;
 532                         break;
 533                 case 'F':
 534                         config = optarg;
 535                         break;
 536                 default:
 537                         usage();
 538                 }
 539         }
 540
 541         ac -= optind;
 542         av += optind;
 543
 544         if (ac > 0 && !host && **av != '-') {
 545                 if (strrchr(*av, '@')) {
 546                         p = xstrdup(*av);
 547                         cp = strrchr(p, '@');
 548                         if (cp == NULL || cp == p)
 549                                 usage();
 550                         options.user = p;
 551                         *cp = '\0';
 552                         host = ++cp;
 553                 } else
 554                         host = *av;
 555                 if (ac > 1) {
 556                         optind = optreset = 1;
 557                         goto again;
 558                 }
 559                 ac--, av++;
 560         }
 561
 562         /* Check that we got a host name. */
 563         if (!host)
 564                 usage();
 565
 566         SSLeay_add_all_algorithms();
 567         ERR_load_crypto_strings();
 568
 569         /* Initialize the command to execute on remote host. */
 570         buffer_init(&command);
 571
 572         /*
 573          * Save the command to execute on the remote host in a buffer. There
 574          * is no limit on the length of the command, except by the maximum
 575          * packet size.  Also sets the tty flag if there is no command.
 576          */
 577         if (!ac) {
 578                 /* No command specified - execute shell on a tty. */
 579                 tty_flag = 1;
 580                 if (subsystem_flag) {
 581                         fprintf(stderr,
 582                             "You must specify a subsystem to invoke.\n");
 583                         usage();
 584                 }
 585         } else {
 586                 /* A command has been specified.  Store it into the buffer. */
 587                 for (i = 0; i < ac; i++) {
 588                         if (i)
 589                                 buffer_append(&command, " ", 1);
 590                         buffer_append(&command, av[i], strlen(av[i]));
 591                 }
 592         }
 593
 594         /* Cannot fork to background if no command. */
 595         if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
 596             !no_shell_flag)
 597                 fatal("Cannot fork into background without a command "
 598                     "to execute.");
 599
 600         /* Allocate a tty by default if no command specified. */
 601         if (buffer_len(&command) == 0)
 602                 tty_flag = 1;
 603
 604         /* Force no tty */
 605         if (no_tty_flag)
 606                 tty_flag = 0;
 607         /* Do not allocate a tty if stdin is not a tty. */
 608         if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
 609                 if (tty_flag)
 610                         logit("Pseudo-terminal will not be allocated because "
 611                             "stdin is not a terminal.");
 612                 tty_flag = 0;
 613         }
 614
 615         /*
 616          * Initialize "log" output.  Since we are the client all output
 617          * actually goes to stderr.
 618          */
 619         log_init(av[0],
 620             options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
 621             SYSLOG_FACILITY_USER, 1);
 622
 623         /*
 624          * Read per-user configuration file.  Ignore the system wide config
 625          * file if the user specifies a config file on the command line.
 626          */
 627         if (config != NULL) {
 628                 if (!read_config_file(config, host, &options, 0))
 629                         fatal("Can't open user config file %.100s: "
 630                             "%.100s", config, strerror(errno));
 631         } else {
 632             /*
 633              * Since the config file parsing code aborts if it sees
 634              * options it doesn't recognize, allow users to put
 635              * options specific to compile-time add-ons in alternate
 636              * config files so their primary config file will
 637              * interoperate SSH versions that don't support those
 638              * options.
 639              */
 640 #ifdef GSSAPI
 641                 snprintf(buf, sizeof buf, "%.100s/%.100s.gssapi", pw->pw_dir,
 642                     _PATH_SSH_USER_CONFFILE);
 643                 (void)read_config_file(buf, host, &options, 1);
 644 #ifdef GSI
 645                 snprintf(buf, sizeof buf, "%.100s/%.100s.gsi", pw->pw_dir,
 646                     _PATH_SSH_USER_CONFFILE);
 647                 (void)read_config_file(buf, host, &options, 1);
 648 #endif
 649 #if defined(KRB5)
 650                 snprintf(buf, sizeof buf, "%.100s/%.100s.krb", pw->pw_dir,
 651                     _PATH_SSH_USER_CONFFILE);
 652                 (void)read_config_file(buf, host, &options, 1);
 653 #endif
 654 #endif
 655                 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
 656                     _PATH_SSH_USER_CONFFILE);
 657                 (void)read_config_file(buf, host, &options, 1);
 658
 659                 /* Read systemwide configuration file after use config. */
 660                 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
 661                     &options, 0);
 662         }
 663
 664         /* Fill configuration defaults. */
 665         fill_default_options(&options);
 666
 667         channel_set_af(options.address_family);
 668
 669         /* reinit */
 670         log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1);
 671
 672         seed_rng();
 673
 674         if (options.user == NULL) {
 675                 options.user = xstrdup(pw->pw_name);
 676                 options.implicit = 1;
 677         }
 678         else options.implicit = 0;
 679
 680         /* Get default port if port has not been set. */
 681         if (options.port == 0) {
 682                 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
 683                 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
 684         }
 685
 686         if (options.local_command != NULL) {
 687                 char thishost[NI_MAXHOST];
 688
 689                 if (gethostname(thishost, sizeof(thishost)) == -1)
 690                         fatal("gethostname: %s", strerror(errno));
 691                 snprintf(buf, sizeof(buf), "%d", options.port);
 692                 debug3("expanding LocalCommand: %s", options.local_command);
 693                 cp = options.local_command;
 694                 options.local_command = percent_expand(cp, "d", pw->pw_dir,
 695                     "h", options.hostname? options.hostname : host,
 696                     "l", thishost, "n", host, "r", options.user, "p", buf,
 697                     "u", pw->pw_name, (char *)NULL);
 698                 debug3("expanded LocalCommand: %s", options.local_command);
 699                 xfree(cp);
 700         }
 701
 702         if (options.hostname != NULL)
 703                 host = options.hostname;
 704
 705         /* force lowercase for hostkey matching */
 706         if (options.host_key_alias != NULL) {
 707                 for (p = options.host_key_alias; *p; p++)
 708                         if (isupper(*p))
 709                                 *p = (char)tolower(*p);
 710         }
 711
 712         if (options.proxy_command != NULL &&
 713             strcmp(options.proxy_command, "none") == 0) {
 714                 xfree(options.proxy_command);
 715                 options.proxy_command = NULL;
 716         }
 717         if (options.control_path != NULL &&
 718             strcmp(options.control_path, "none") == 0) {
 719                 xfree(options.control_path);
 720                 options.control_path = NULL;
 721         }
 722
 723         if (options.control_path != NULL) {
 724                 char thishost[NI_MAXHOST];
 725
 726                 if (gethostname(thishost, sizeof(thishost)) == -1)
 727                         fatal("gethostname: %s", strerror(errno));
 728                 snprintf(buf, sizeof(buf), "%d", options.port);
 729                 cp = tilde_expand_filename(options.control_path,
 730                     original_real_uid);
 731                 xfree(options.control_path);
 732                 options.control_path = percent_expand(cp, "p", buf, "h", host,
 733                     "r", options.user, "l", thishost, (char *)NULL);
 734                 xfree(cp);
 735         }
 736         if (muxclient_command != 0 && options.control_path == NULL)
 737                 fatal("No ControlPath specified for \"-O\" command");
 738         if (options.control_path != NULL)
 739                 muxclient(options.control_path);
 740
 741         timeout_ms = options.connection_timeout * 1000;
 742
 743         /* Open a connection to the remote host. */
 744         if (ssh_connect(host, &hostaddr, options.port,
 745             options.address_family, options.connection_attempts, &timeout_ms,
 746             options.tcp_keep_alive,
 747 #ifdef HAVE_CYGWIN
 748             options.use_privileged_port,
 749 #else
 750             original_effective_uid == 0 && options.use_privileged_port,
 751 #endif
 752             options.proxy_command) != 0)
 753                 exit(255);
 754
 755         if (timeout_ms > 0)
 756                 debug3("timeout: %d ms remain after connect", timeout_ms);
 757
 758         /*
 759          * If we successfully made the connection, load the host private key
 760          * in case we will need it later for combined rsa-rhosts
 761          * authentication. This must be done before releasing extra
 762          * privileges, because the file is only readable by root.
 763          * If we cannot access the private keys, load the public keys
 764          * instead and try to execute the ssh-keysign helper instead.
 765          */
 766         sensitive_data.nkeys = 0;
 767         sensitive_data.keys = NULL;
 768         sensitive_data.external_keysign = 0;
 769         if (options.rhosts_rsa_authentication ||
 770             options.hostbased_authentication) {
 771                 sensitive_data.nkeys = 3;
 772                 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
 773                     sizeof(Key));
 774
 775                 PRIV_START;
 776                 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
 777                     _PATH_HOST_KEY_FILE, "", NULL, NULL);
 778                 sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
 779                     _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
 780                 sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
 781                     _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
 782                 PRIV_END;
 783
 784                 if (options.hostbased_authentication == 1 &&
 785                     sensitive_data.keys[0] == NULL &&
 786                     sensitive_data.keys[1] == NULL &&
 787                     sensitive_data.keys[2] == NULL) {
 788                         sensitive_data.keys[1] = key_load_public(
 789                             _PATH_HOST_DSA_KEY_FILE, NULL);
 790                         sensitive_data.keys[2] = key_load_public(
 791                             _PATH_HOST_RSA_KEY_FILE, NULL);
 792                         sensitive_data.external_keysign = 1;
 793                 }
 794         }
 795         /*
 796          * Get rid of any extra privileges that we may have.  We will no
 797          * longer need them.  Also, extra privileges could make it very hard
 798          * to read identity files and other non-world-readable files from the
 799          * user's home directory if it happens to be on a NFS volume where
 800          * root is mapped to nobody.
 801          */
 802         if (original_effective_uid == 0) {
 803                 PRIV_START;
 804                 permanently_set_uid(pw);
 805         }
 806
 807         /*
 808          * Now that we are back to our own permissions, create ~/.ssh
 809          * directory if it doesn't already exist.
 810          */
 811         snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir,
 812             strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
 813         if (stat(buf, &st) < 0)
 814                 if (mkdir(buf, 0700) < 0)
 815                         error("Could not create directory '%.200s'.", buf);
 816
 817         /* load options.identity_files */
 818         load_public_identity_files();
 819
 820         /* Expand ~ in known host file names. */
 821         /* XXX mem-leaks: */
 822         options.system_hostfile =
 823             tilde_expand_filename(options.system_hostfile, original_real_uid);
 824         options.user_hostfile =
 825             tilde_expand_filename(options.user_hostfile, original_real_uid);
 826         options.system_hostfile2 =
 827             tilde_expand_filename(options.system_hostfile2, original_real_uid);
 828         options.user_hostfile2 =
 829             tilde_expand_filename(options.user_hostfile2, original_real_uid);
 830
 831         signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
 832
 833         /* Log into the remote system.  Never returns if the login fails. */
 834         ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
 835             pw, timeout_ms);
 836
 837         /* We no longer need the private host keys.  Clear them now. */
 838         if (sensitive_data.nkeys != 0) {
 839                 for (i = 0; i < sensitive_data.nkeys; i++) {
 840                         if (sensitive_data.keys[i] != NULL) {
 841                                 /* Destroys contents safely */
 842                                 debug3("clear hostkey %d", i);
 843                                 key_free(sensitive_data.keys[i]);
 844                                 sensitive_data.keys[i] = NULL;
 845                         }
 846                 }
 847                 xfree(sensitive_data.keys);
 848         }
 849         for (i = 0; i < options.num_identity_files; i++) {
 850                 if (options.identity_files[i]) {
 851                         xfree(options.identity_files[i]);
 852                         options.identity_files[i] = NULL;
 853                 }
 854                 if (options.identity_keys[i]) {
 855                         key_free(options.identity_keys[i]);
 856                         options.identity_keys[i] = NULL;
 857                 }
 858         }
 859
 860         exit_status = compat20 ? ssh_session2() : ssh_session();
 861         packet_close();
 862
 863         if (options.control_path != NULL && muxserver_sock != -1)
 864                 unlink(options.control_path);
 865
 866         /*
 867          * Send SIGHUP to proxy command if used. We don't wait() in
 868          * case it hangs and instead rely on init to reap the child
 869          */
 870         if (proxy_command_pid > 1)
 871                 kill(proxy_command_pid, SIGHUP);
 872
 873         return exit_status;
 874 }
 875
 876 /* Callback for remote forward global requests */
 877 static void
 878 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
 879 {
 880         Forward *rfwd = (Forward *)ctxt;
 881
 882         debug("remote forward %s for: listen %d, connect %s:%d",
 883             type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
 884             rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
 885         if (type == SSH2_MSG_REQUEST_FAILURE) {
 886                 if (options.exit_on_forward_failure)
 887                         fatal("Error: remote port forwarding failed for "
 888                             "listen port %d", rfwd->listen_port);
 889                 else
 890                         logit("Warning: remote port forwarding failed for "
 891                             "listen port %d", rfwd->listen_port);
 892         }
 893         if (++remote_forward_confirms_received == options.num_remote_forwards) {
 894                 debug("All remote forwarding requests processed");
 895                 if (fork_after_authentication_flag) {
 896                         fork_after_authentication_flag = 0;
 897                         if (daemon(1, 1) < 0)
 898                                 fatal("daemon() failed: %.200s",
 899                                     strerror(errno));
 900                 }
 901         }
 902 }
 903
 904 static void
 905 ssh_init_forwarding(void)
 906 {
 907         int success = 0;
 908         int i;
 909
 910         /* Initiate local TCP/IP port forwardings. */
 911         for (i = 0; i < options.num_local_forwards; i++) {
 912                 debug("Local connections to %.200s:%d forwarded to remote "
 913                     "address %.200s:%d",
 914                     (options.local_forwards[i].listen_host == NULL) ?
 915                     (options.gateway_ports ? "*" : "LOCALHOST") :
 916                     options.local_forwards[i].listen_host,
 917                     options.local_forwards[i].listen_port,
 918                     options.local_forwards[i].connect_host,
 919                     options.local_forwards[i].connect_port);
 920                 success += channel_setup_local_fwd_listener(
 921                     options.local_forwards[i].listen_host,
 922                     options.local_forwards[i].listen_port,
 923                     options.local_forwards[i].connect_host,
 924                     options.local_forwards[i].connect_port,
 925                     options.gateway_ports, options.hpn_disabled,
 926                     options.hpn_buffer_size);
 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(options.hpn_disabled)
1221         {
1222                 options.hpn_buffer_size = CHAN_SES_WINDOW_DEFAULT;
1223         }
1224         else if (datafellows & SSH_BUG_LARGEWINDOW)
1225         {
1226                 debug("HPN to Non-HPN Connection");
1227                 if (options.hpn_buffer_size < 0)
1228                         options.hpn_buffer_size = 2*1024*1024;
1229         }
1230         else
1231         {
1232                 if (options.hpn_buffer_size < 0)
1233                         options.hpn_buffer_size = BUFFER_MAX_LEN_HPN;
1234
1235                 /*create a socket but don't connect it */
1236                 /* we use that the get the rcv socket size */
1237                 sock = socket(AF_INET, SOCK_STREAM, 0);
1238                 /* if they are using the tcp_rcv_buf option */
1239                 /* attempt to set the buffer size to that */
1240                 if (options.tcp_rcv_buf)
1241                         setsockopt(sock, SOL_SOCKET, SO_RCVBUF, (void *)&options.tcp_rcv_buf,
1242                                    sizeof(options.tcp_rcv_buf));
1243                 getsockopt(sock, SOL_SOCKET, SO_RCVBUF,
1244                            &socksize, &socksizelen);
1245                 close(sock);
1246                 debug("socksize %d", socksize);
1247                 if (options.tcp_rcv_buf_poll <= 0)
1248                 {
1249                         options.hpn_buffer_size = MIN(socksize,options.hpn_buffer_size);
1250                         debug ("MIN of TCP RWIN and HPNBufferSize: %d", options.hpn_buffer_size);
1251                 }
1252                 else
1253                 {
1254                         if (options.tcp_rcv_buf > 0)
1255                                 options.hpn_buffer_size = MIN(options.tcp_rcv_buf, options.hpn_buffer_size);
1256                                 debug ("MIN of TCPRcvBuf and HPNBufferSize: %d", options.hpn_buffer_size);
1257                 }
1258
1259         }
1260
1261         debug("Final hpn_buffer_size = %d", options.hpn_buffer_size);
1262
1263         window = 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
1276         if ((options.tcp_rcv_buf_poll > 0) && (!options.hpn_disabled)) {
1277                 c->dynamic_window = 1;
1278                 debug ("Enabled Dynamic Window Scaling\n");
1279         }
1280         debug3("ssh_session2_open: channel_new: %d", c->self);
1281
1282         channel_send_open(c->self);
1283         if (!no_shell_flag)
1284                 channel_register_open_confirm(c->self,
1285                     ssh_session2_setup, NULL);
1286
1287         return c->self;
1288 }
1289
1290 static int
1291 ssh_session2(void)
1292 {
1293         int id = -1;
1294
1295         /* XXX should be pre-session */
1296         ssh_init_forwarding();
1297
1298         if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1299                 id = ssh_session2_open();
1300
1301         /* If we don't expect to open a new session, then disallow it */
1302         if (options.control_master == SSHCTL_MASTER_NO) {
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 }