crypto/openssh/ssh.c

   1 /* $OpenBSD: ssh.c,v 1.335 2010/02/26 20:29:54 djm Exp $ */
   2 /* $FreeBSD$ */
   3 /*
   4  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   5  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   6  *                    All rights reserved
   7  * Ssh client program.  This program can be used to log into a remote machine.
   8  * The software supports strong authentication, encryption, and forwarding
   9  * of X11, TCP/IP, and authentication connections.
  10  *
  11  * As far as I am concerned, the code I have written for this software
  12  * can be used freely for any purpose.  Any derived versions of this
  13  * software must be clearly marked as such, and if the derived work is
  14  * incompatible with the protocol description in the RFC file, it must be
  15  * called by a name other than "ssh" or "Secure Shell".
  16  *
  17  * Copyright (c) 1999 Niels Provos.  All rights reserved.
  18  * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl.  All rights reserved.
  19  *
  20  * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
  21  * in Canada (German citizen).
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the above copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  *
  32  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  33  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  34  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  35  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  36  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  37  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  38  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  39  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  40  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  41  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  42  */
  43
  44 #include "includes.h"
  45 __RCSID("$FreeBSD$");
  46
  47 #include <sys/types.h>
  48 #ifdef HAVE_SYS_STAT_H
  49 # include <sys/stat.h>
  50 #endif
  51 #include <sys/resource.h>
  52 #include <sys/ioctl.h>
  53 #include <sys/param.h>
  54 #include <sys/socket.h>
  55
  56 #include <ctype.h>
  57 #include <errno.h>
  58 #include <fcntl.h>
  59 #include <netdb.h>
  60 #ifdef HAVE_PATHS_H
  61 #include <paths.h>
  62 #endif
  63 #include <pwd.h>
  64 #include <signal.h>
  65 #include <stdarg.h>
  66 #include <stddef.h>
  67 #include <stdio.h>
  68 #include <stdlib.h>
  69 #include <string.h>
  70 #include <unistd.h>
  71
  72 #include <netinet/in.h>
  73 #include <arpa/inet.h>
  74
  75 #include <openssl/evp.h>
  76 #include <openssl/err.h>
  77 #include "openbsd-compat/openssl-compat.h"
  78 #include "openbsd-compat/sys-queue.h"
  79
  80 #include "xmalloc.h"
  81 #include "ssh.h"
  82 #include "ssh1.h"
  83 #include "ssh2.h"
  84 #include "compat.h"
  85 #include "cipher.h"
  86 #include "packet.h"
  87 #include "buffer.h"
  88 #include "channels.h"
  89 #include "key.h"
  90 #include "authfd.h"
  91 #include "authfile.h"
  92 #include "pathnames.h"
  93 #include "dispatch.h"
  94 #include "clientloop.h"
  95 #include "log.h"
  96 #include "readconf.h"
  97 #include "sshconnect.h"
  98 #include "misc.h"
  99 #include "kex.h"
 100 #include "mac.h"
 101 #include "sshpty.h"
 102 #include "match.h"
 103 #include "msg.h"
 104 #include "uidswap.h"
 105 #include "roaming.h"
 106 #include "version.h"
 107
 108 #ifdef ENABLE_PKCS11
 109 #include "ssh-pkcs11.h"
 110 #endif
 111
 112 extern char *__progname;
 113
 114 /* Flag indicating whether debug mode is on.  May be set on the command line. */
 115 int debug_flag = 0;
 116
 117 /* Flag indicating whether a tty should be allocated */
 118 int tty_flag = 0;
 119 int no_tty_flag = 0;
 120 int force_tty_flag = 0;
 121
 122 /* don't exec a shell */
 123 int no_shell_flag = 0;
 124
 125 /*
 126  * Flag indicating that nothing should be read from stdin.  This can be set
 127  * on the command line.
 128  */
 129 int stdin_null_flag = 0;
 130
 131 /*
 132  * Flag indicating that ssh should fork after authentication.  This is useful
 133  * so that the passphrase can be entered manually, and then ssh goes to the
 134  * background.
 135  */
 136 int fork_after_authentication_flag = 0;
 137
 138 /* forward stdio to remote host and port */
 139 char *stdio_forward_host = NULL;
 140 int stdio_forward_port = 0;
 141
 142 /*
 143  * General data structure for command line options and options configurable
 144  * in configuration files.  See readconf.h.
 145  */
 146 Options options;
 147
 148 /* optional user configfile */
 149 char *config = NULL;
 150
 151 /*
 152  * Name of the host we are connecting to.  This is the name given on the
 153  * command line, or the HostName specified for the user-supplied name in a
 154  * configuration file.
 155  */
 156 char *host;
 157
 158 /* socket address the host resolves to */
 159 struct sockaddr_storage hostaddr;
 160
 161 /* Private host keys. */
 162 Sensitive sensitive_data;
 163
 164 /* Original real UID. */
 165 uid_t original_real_uid;
 166 uid_t original_effective_uid;
 167
 168 /* command to be executed */
 169 Buffer command;
 170
 171 /* Should we execute a command or invoke a subsystem? */
 172 int subsystem_flag = 0;
 173
 174 /* # of replies received for global requests */
 175 static int remote_forward_confirms_received = 0;
 176
 177 /* pid of proxycommand child process */
 178 pid_t proxy_command_pid = 0;
 179
 180 /* mux.c */
 181 extern int muxserver_sock;
 182 extern u_int muxclient_command;
 183
 184 /* Prints a help message to the user.  This function never returns. */
 185
 186 static void
 187 usage(void)
 188 {
 189         fprintf(stderr,
 190 "usage: ssh [-1246AaCfgKkMNnqsTtVvXxYy] [-b bind_address] [-c cipher_spec]\n"
 191 "           [-D [bind_address:]port] [-e escape_char] [-F configfile]\n"
 192 "           [-I pkcs11] [-i identity_file]\n"
 193 "           [-L [bind_address:]port:host:hostport]\n"
 194 "           [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
 195 "           [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
 196 "           [-W host:port] [-w local_tun[:remote_tun]]\n"
 197 "           [user@]hostname [command]\n"
 198         );
 199         exit(255);
 200 }
 201
 202 static int ssh_session(void);
 203 static int ssh_session2(void);
 204 static void load_public_identity_files(void);
 205
 206 /* from muxclient.c */
 207 void muxclient(const char *);
 208 void muxserver_listen(void);
 209
 210 /*
 211  * Main program for the ssh client.
 212  */
 213 int
 214 main(int ac, char **av)
 215 {
 216         int i, r, opt, exit_status, use_syslog;
 217         char *p, *cp, *line, *argv0, buf[MAXPATHLEN];
 218         struct stat st;
 219         struct passwd *pw;
 220         int dummy, timeout_ms;
 221         extern int optind, optreset;
 222         extern char *optarg;
 223         struct servent *sp;
 224         Forward fwd;
 225
 226         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 227         sanitise_stdfd();
 228
 229         __progname = ssh_get_progname(av[0]);
 230         init_rng();
 231
 232         /*
 233          * Save the original real uid.  It will be needed later (uid-swapping
 234          * may clobber the real uid).
 235          */
 236         original_real_uid = getuid();
 237         original_effective_uid = geteuid();
 238
 239         /*
 240          * Use uid-swapping to give up root privileges for the duration of
 241          * option processing.  We will re-instantiate the rights when we are
 242          * ready to create the privileged port, and will permanently drop
 243          * them when the port has been created (actually, when the connection
 244          * has been made, as we may need to create the port several times).
 245          */
 246         PRIV_END;
 247
 248 #ifdef HAVE_SETRLIMIT
 249         /* If we are installed setuid root be careful to not drop core. */
 250         if (original_real_uid != original_effective_uid) {
 251                 struct rlimit rlim;
 252                 rlim.rlim_cur = rlim.rlim_max = 0;
 253                 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
 254                         fatal("setrlimit failed: %.100s", strerror(errno));
 255         }
 256 #endif
 257         /* Get user data. */
 258         pw = getpwuid(original_real_uid);
 259         if (!pw) {
 260                 logit("You don't exist, go away!");
 261                 exit(255);
 262         }
 263         /* Take a copy of the returned structure. */
 264         pw = pwcopy(pw);
 265
 266         /*
 267          * Set our umask to something reasonable, as some files are created
 268          * with the default umask.  This will make them world-readable but
 269          * writable only by the owner, which is ok for all files for which we
 270          * don't set the modes explicitly.
 271          */
 272         umask(022);
 273
 274         /*
 275          * Initialize option structure to indicate that no values have been
 276          * set.
 277          */
 278         initialize_options(&options);
 279
 280         /* Parse command-line arguments. */
 281         host = NULL;
 282         use_syslog = 0;
 283         argv0 = av[0];
 284
 285  again:
 286         while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
 287             "ACD:F:I:KL:MNO:PR:S:TVw:W:XYy")) != -1) {
 288                 switch (opt) {
 289                 case '1':
 290                         options.protocol = SSH_PROTO_1;
 291                         break;
 292                 case '2':
 293                         options.protocol = SSH_PROTO_2;
 294                         break;
 295                 case '4':
 296                         options.address_family = AF_INET;
 297                         break;
 298                 case '6':
 299                         options.address_family = AF_INET6;
 300                         break;
 301                 case 'n':
 302                         stdin_null_flag = 1;
 303                         break;
 304                 case 'f':
 305                         fork_after_authentication_flag = 1;
 306                         stdin_null_flag = 1;
 307                         break;
 308                 case 'x':
 309                         options.forward_x11 = 0;
 310                         break;
 311                 case 'X':
 312                         options.forward_x11 = 1;
 313                         break;
 314                 case 'y':
 315                         use_syslog = 1;
 316                         break;
 317                 case 'Y':
 318                         options.forward_x11 = 1;
 319                         options.forward_x11_trusted = 1;
 320                         break;
 321                 case 'g':
 322                         options.gateway_ports = 1;
 323                         break;
 324                 case 'O':
 325                         if (stdio_forward_host != NULL)
 326                                 fatal("Cannot specify multiplexing "
 327                                     "command with -W");
 328                         else if (muxclient_command != 0)
 329                                 fatal("Multiplexing command already specified");
 330                         if (strcmp(optarg, "check") == 0)
 331                                 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
 332                         else if (strcmp(optarg, "exit") == 0)
 333                                 muxclient_command = SSHMUX_COMMAND_TERMINATE;
 334                         else
 335                                 fatal("Invalid multiplex command.");
 336                         break;
 337                 case 'P':       /* deprecated */
 338                         options.use_privileged_port = 0;
 339                         break;
 340                 case 'a':
 341                         options.forward_agent = 0;
 342                         break;
 343                 case 'A':
 344                         options.forward_agent = 1;
 345                         break;
 346                 case 'k':
 347                         options.gss_deleg_creds = 0;
 348                         break;
 349                 case 'K':
 350                         options.gss_authentication = 1;
 351                         options.gss_deleg_creds = 1;
 352                         break;
 353                 case 'i':
 354                         if (stat(optarg, &st) < 0) {
 355                                 fprintf(stderr, "Warning: Identity file %s "
 356                                     "not accessible: %s.\n", optarg,
 357                                     strerror(errno));
 358                                 break;
 359                         }
 360                         if (options.num_identity_files >=
 361                             SSH_MAX_IDENTITY_FILES)
 362                                 fatal("Too many identity files specified "
 363                                     "(max %d)", SSH_MAX_IDENTITY_FILES);
 364                         options.identity_files[options.num_identity_files++] =
 365                             xstrdup(optarg);
 366                         break;
 367                 case 'I':
 368 #ifdef ENABLE_PKCS11
 369                         options.pkcs11_provider = xstrdup(optarg);
 370 #else
 371                         fprintf(stderr, "no support for PKCS#11.\n");
 372 #endif
 373                         break;
 374                 case 't':
 375                         if (tty_flag)
 376                                 force_tty_flag = 1;
 377                         tty_flag = 1;
 378                         break;
 379                 case 'v':
 380                         if (debug_flag == 0) {
 381                                 debug_flag = 1;
 382                                 options.log_level = SYSLOG_LEVEL_DEBUG1;
 383                         } else {
 384                                 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
 385                                         options.log_level++;
 386                                 break;
 387                         }
 388                         /* FALLTHROUGH */
 389                 case 'V':
 390                         fprintf(stderr, "%s, %s\n",
 391                             SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
 392                         if (opt == 'V')
 393                                 exit(0);
 394                         break;
 395                 case 'w':
 396                         if (options.tun_open == -1)
 397                                 options.tun_open = SSH_TUNMODE_DEFAULT;
 398                         options.tun_local = a2tun(optarg, &options.tun_remote);
 399                         if (options.tun_local == SSH_TUNID_ERR) {
 400                                 fprintf(stderr,
 401                                     "Bad tun device '%s'\n", optarg);
 402                                 exit(255);
 403                         }
 404                         break;
 405                 case 'W':
 406                         if (stdio_forward_host != NULL)
 407                                 fatal("stdio forward already specified");
 408                         if (muxclient_command != 0)
 409                                 fatal("Cannot specify stdio forward with -O");
 410                         if (parse_forward(&fwd, optarg, 1, 0)) {
 411                                 stdio_forward_host = fwd.listen_host;
 412                                 stdio_forward_port = fwd.listen_port;
 413                                 xfree(fwd.connect_host);
 414                         } else {
 415                                 fprintf(stderr,
 416                                     "Bad stdio forwarding specification '%s'\n",
 417                                     optarg);
 418                                 exit(255);
 419                         }
 420                         no_tty_flag = 1;
 421                         no_shell_flag = 1;
 422                         options.clear_forwardings = 1;
 423                         options.exit_on_forward_failure = 1;
 424                         break;
 425                 case 'q':
 426                         options.log_level = SYSLOG_LEVEL_QUIET;
 427                         break;
 428                 case 'e':
 429                         if (optarg[0] == '^' && optarg[2] == 0 &&
 430                             (u_char) optarg[1] >= 64 &&
 431                             (u_char) optarg[1] < 128)
 432                                 options.escape_char = (u_char) optarg[1] & 31;
 433                         else if (strlen(optarg) == 1)
 434                                 options.escape_char = (u_char) optarg[0];
 435                         else if (strcmp(optarg, "none") == 0)
 436                                 options.escape_char = SSH_ESCAPECHAR_NONE;
 437                         else {
 438                                 fprintf(stderr, "Bad escape character '%s'.\n",
 439                                     optarg);
 440                                 exit(255);
 441                         }
 442                         break;
 443                 case 'c':
 444                         if (ciphers_valid(optarg)) {
 445                                 /* SSH2 only */
 446                                 options.ciphers = xstrdup(optarg);
 447                                 options.cipher = SSH_CIPHER_INVALID;
 448                         } else {
 449                                 /* SSH1 only */
 450                                 options.cipher = cipher_number(optarg);
 451                                 if (options.cipher == -1) {
 452                                         fprintf(stderr,
 453                                             "Unknown cipher type '%s'\n",
 454                                             optarg);
 455                                         exit(255);
 456                                 }
 457                                 if (options.cipher == SSH_CIPHER_3DES)
 458                                         options.ciphers = "3des-cbc";
 459                                 else if (options.cipher == SSH_CIPHER_BLOWFISH)
 460                                         options.ciphers = "blowfish-cbc";
 461                                 else
 462                                         options.ciphers = (char *)-1;
 463                         }
 464                         break;
 465                 case 'm':
 466                         if (mac_valid(optarg))
 467                                 options.macs = xstrdup(optarg);
 468                         else {
 469                                 fprintf(stderr, "Unknown mac type '%s'\n",
 470                                     optarg);
 471                                 exit(255);
 472                         }
 473                         break;
 474                 case 'M':
 475                         if (options.control_master == SSHCTL_MASTER_YES)
 476                                 options.control_master = SSHCTL_MASTER_ASK;
 477                         else
 478                                 options.control_master = SSHCTL_MASTER_YES;
 479                         break;
 480                 case 'p':
 481                         options.port = a2port(optarg);
 482                         if (options.port <= 0) {
 483                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 484                                 exit(255);
 485                         }
 486                         break;
 487                 case 'l':
 488                         options.user = optarg;
 489                         break;
 490
 491                 case 'L':
 492                         if (parse_forward(&fwd, optarg, 0, 0))
 493                                 add_local_forward(&options, &fwd);
 494                         else {
 495                                 fprintf(stderr,
 496                                     "Bad local forwarding specification '%s'\n",
 497                                     optarg);
 498                                 exit(255);
 499                         }
 500                         break;
 501
 502                 case 'R':
 503                         if (parse_forward(&fwd, optarg, 0, 1)) {
 504                                 add_remote_forward(&options, &fwd);
 505                         } else {
 506                                 fprintf(stderr,
 507                                     "Bad remote forwarding specification "
 508                                     "'%s'\n", optarg);
 509                                 exit(255);
 510                         }
 511                         break;
 512
 513                 case 'D':
 514                         if (parse_forward(&fwd, optarg, 1, 0)) {
 515                                 add_local_forward(&options, &fwd);
 516                         } else {
 517                                 fprintf(stderr,
 518                                     "Bad dynamic forwarding specification "
 519                                     "'%s'\n", optarg);
 520                                 exit(255);
 521                         }
 522                         break;
 523
 524                 case 'C':
 525                         options.compression = 1;
 526                         break;
 527                 case 'N':
 528                         no_shell_flag = 1;
 529                         no_tty_flag = 1;
 530                         break;
 531                 case 'T':
 532                         no_tty_flag = 1;
 533 #ifdef  NONE_CIPHER_ENABLED
 534                         /*
 535                          * Ensure that the user does not try to backdoor a
 536                          * NONE cipher switch on an interactive session by
 537                          * explicitly disabling it if the user asks for a
 538                          * session without a tty.
 539                          */
 540                         options.none_switch = 0;
 541 #endif
 542                         break;
 543                 case 'o':
 544                         dummy = 1;
 545                         line = xstrdup(optarg);
 546                         if (process_config_line(&options, host ? host : "",
 547                             line, "command-line", 0, &dummy) != 0)
 548                                 exit(255);
 549                         xfree(line);
 550                         break;
 551                 case 's':
 552                         subsystem_flag = 1;
 553                         break;
 554                 case 'S':
 555                         if (options.control_path != NULL)
 556                                 free(options.control_path);
 557                         options.control_path = xstrdup(optarg);
 558                         break;
 559                 case 'b':
 560                         options.bind_address = optarg;
 561                         break;
 562                 case 'F':
 563                         config = optarg;
 564                         break;
 565                 default:
 566                         usage();
 567                 }
 568         }
 569
 570         ac -= optind;
 571         av += optind;
 572
 573         if (ac > 0 && !host) {
 574                 if (strrchr(*av, '@')) {
 575                         p = xstrdup(*av);
 576                         cp = strrchr(p, '@');
 577                         if (cp == NULL || cp == p)
 578                                 usage();
 579                         options.user = p;
 580                         *cp = '\0';
 581                         host = ++cp;
 582                 } else
 583                         host = *av;
 584                 if (ac > 1) {
 585                         optind = optreset = 1;
 586                         goto again;
 587                 }
 588                 ac--, av++;
 589         }
 590
 591         /* Check that we got a host name. */
 592         if (!host)
 593                 usage();
 594
 595         SSLeay_add_all_algorithms();
 596         ERR_load_crypto_strings();
 597
 598         /* Initialize the command to execute on remote host. */
 599         buffer_init(&command);
 600
 601         /*
 602          * Save the command to execute on the remote host in a buffer. There
 603          * is no limit on the length of the command, except by the maximum
 604          * packet size.  Also sets the tty flag if there is no command.
 605          */
 606         if (!ac) {
 607                 /* No command specified - execute shell on a tty. */
 608                 tty_flag = 1;
 609                 if (subsystem_flag) {
 610                         fprintf(stderr,
 611                             "You must specify a subsystem to invoke.\n");
 612                         usage();
 613                 }
 614         } else {
 615                 /* A command has been specified.  Store it into the buffer. */
 616                 for (i = 0; i < ac; i++) {
 617                         if (i)
 618                                 buffer_append(&command, " ", 1);
 619                         buffer_append(&command, av[i], strlen(av[i]));
 620                 }
 621         }
 622
 623         /* Cannot fork to background if no command. */
 624         if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
 625             !no_shell_flag)
 626                 fatal("Cannot fork into background without a command "
 627                     "to execute.");
 628
 629         /* Allocate a tty by default if no command specified. */
 630         if (buffer_len(&command) == 0)
 631                 tty_flag = 1;
 632
 633         /* Force no tty */
 634         if (no_tty_flag)
 635                 tty_flag = 0;
 636         /* Do not allocate a tty if stdin is not a tty. */
 637         if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
 638                 if (tty_flag)
 639                         logit("Pseudo-terminal will not be allocated because "
 640                             "stdin is not a terminal.");
 641                 tty_flag = 0;
 642         }
 643
 644         /*
 645          * Initialize "log" output.  Since we are the client all output
 646          * actually goes to stderr.
 647          */
 648         log_init(argv0,
 649             options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
 650             SYSLOG_FACILITY_USER, !use_syslog);
 651
 652         /*
 653          * Read per-user configuration file.  Ignore the system wide config
 654          * file if the user specifies a config file on the command line.
 655          */
 656         if (config != NULL) {
 657                 if (!read_config_file(config, host, &options, 0))
 658                         fatal("Can't open user config file %.100s: "
 659                             "%.100s", config, strerror(errno));
 660         } else {
 661                 r = snprintf(buf, sizeof buf, "%s/%s", pw->pw_dir,
 662                     _PATH_SSH_USER_CONFFILE);
 663                 if (r > 0 && (size_t)r < sizeof(buf))
 664                         (void)read_config_file(buf, host, &options, 1);
 665
 666                 /* Read systemwide configuration file after use config. */
 667                 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
 668                     &options, 0);
 669         }
 670
 671         /* Fill configuration defaults. */
 672         fill_default_options(&options);
 673
 674         channel_set_af(options.address_family);
 675
 676         /* reinit */
 677         log_init(argv0, options.log_level, SYSLOG_FACILITY_USER, !use_syslog);
 678
 679         seed_rng();
 680
 681         if (options.user == NULL)
 682                 options.user = xstrdup(pw->pw_name);
 683
 684         /* Get default port if port has not been set. */
 685         if (options.port == 0) {
 686                 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
 687                 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
 688         }
 689
 690         if (options.local_command != NULL) {
 691                 char thishost[NI_MAXHOST];
 692
 693                 if (gethostname(thishost, sizeof(thishost)) == -1)
 694                         fatal("gethostname: %s", strerror(errno));
 695                 snprintf(buf, sizeof(buf), "%d", options.port);
 696                 debug3("expanding LocalCommand: %s", options.local_command);
 697                 cp = options.local_command;
 698                 options.local_command = percent_expand(cp, "d", pw->pw_dir,
 699                     "h", options.hostname? options.hostname : host,
 700                     "l", thishost, "n", host, "r", options.user, "p", buf,
 701                     "u", pw->pw_name, (char *)NULL);
 702                 debug3("expanded LocalCommand: %s", options.local_command);
 703                 xfree(cp);
 704         }
 705
 706         if (options.hostname != NULL)
 707                 host = options.hostname;
 708
 709         /* Find canonic host name. */
 710         if (strchr(host, '.') == 0) {
 711                 struct addrinfo hints;
 712                 struct addrinfo *ai = NULL;
 713                 int errgai;
 714                 memset(&hints, 0, sizeof(hints));
 715                 hints.ai_family = options.address_family;
 716                 hints.ai_flags = AI_CANONNAME;
 717                 hints.ai_socktype = SOCK_STREAM;
 718                 errgai = getaddrinfo(host, NULL, &hints, &ai);
 719                 if (errgai == 0) {
 720                         if (ai->ai_canonname != NULL)
 721                                 host = xstrdup(ai->ai_canonname);
 722                         freeaddrinfo(ai);
 723                 }
 724         }
 725
 726         /* force lowercase for hostkey matching */
 727         if (options.host_key_alias != NULL) {
 728                 for (p = options.host_key_alias; *p; p++)
 729                         if (isupper(*p))
 730                                 *p = (char)tolower(*p);
 731         }
 732
 733         if (options.proxy_command != NULL &&
 734             strcmp(options.proxy_command, "none") == 0) {
 735                 xfree(options.proxy_command);
 736                 options.proxy_command = NULL;
 737         }
 738         if (options.control_path != NULL &&
 739             strcmp(options.control_path, "none") == 0) {
 740                 xfree(options.control_path);
 741                 options.control_path = NULL;
 742         }
 743
 744         if (options.control_path != NULL) {
 745                 char thishost[NI_MAXHOST];
 746
 747                 if (gethostname(thishost, sizeof(thishost)) == -1)
 748                         fatal("gethostname: %s", strerror(errno));
 749                 snprintf(buf, sizeof(buf), "%d", options.port);
 750                 cp = tilde_expand_filename(options.control_path,
 751                     original_real_uid);
 752                 xfree(options.control_path);
 753                 options.control_path = percent_expand(cp, "p", buf, "h", host,
 754                     "r", options.user, "l", thishost, (char *)NULL);
 755                 xfree(cp);
 756         }
 757         if (muxclient_command != 0 && options.control_path == NULL)
 758                 fatal("No ControlPath specified for \"-O\" command");
 759         if (options.control_path != NULL)
 760                 muxclient(options.control_path);
 761
 762         timeout_ms = options.connection_timeout * 1000;
 763
 764         /* Open a connection to the remote host. */
 765         if (ssh_connect(host, &hostaddr, options.port,
 766             options.address_family, options.connection_attempts, &timeout_ms,
 767             options.tcp_keep_alive,
 768 #ifdef HAVE_CYGWIN
 769             options.use_privileged_port,
 770 #else
 771             original_effective_uid == 0 && options.use_privileged_port,
 772 #endif
 773             options.proxy_command) != 0)
 774                 exit(255);
 775
 776         if (timeout_ms > 0)
 777                 debug3("timeout: %d ms remain after connect", timeout_ms);
 778
 779         /*
 780          * If we successfully made the connection, load the host private key
 781          * in case we will need it later for combined rsa-rhosts
 782          * authentication. This must be done before releasing extra
 783          * privileges, because the file is only readable by root.
 784          * If we cannot access the private keys, load the public keys
 785          * instead and try to execute the ssh-keysign helper instead.
 786          */
 787         sensitive_data.nkeys = 0;
 788         sensitive_data.keys = NULL;
 789         sensitive_data.external_keysign = 0;
 790         if (options.rhosts_rsa_authentication ||
 791             options.hostbased_authentication) {
 792                 sensitive_data.nkeys = 3;
 793                 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
 794                     sizeof(Key));
 795
 796                 PRIV_START;
 797                 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
 798                     _PATH_HOST_KEY_FILE, "", NULL, NULL);
 799                 sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
 800                     _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
 801                 sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
 802                     _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
 803                 PRIV_END;
 804
 805                 if (options.hostbased_authentication == 1 &&
 806                     sensitive_data.keys[0] == NULL &&
 807                     sensitive_data.keys[1] == NULL &&
 808                     sensitive_data.keys[2] == NULL) {
 809                         sensitive_data.keys[1] = key_load_public(
 810                             _PATH_HOST_DSA_KEY_FILE, NULL);
 811                         sensitive_data.keys[2] = key_load_public(
 812                             _PATH_HOST_RSA_KEY_FILE, NULL);
 813                         sensitive_data.external_keysign = 1;
 814                 }
 815         }
 816         /*
 817          * Get rid of any extra privileges that we may have.  We will no
 818          * longer need them.  Also, extra privileges could make it very hard
 819          * to read identity files and other non-world-readable files from the
 820          * user's home directory if it happens to be on a NFS volume where
 821          * root is mapped to nobody.
 822          */
 823         if (original_effective_uid == 0) {
 824                 PRIV_START;
 825                 permanently_set_uid(pw);
 826         }
 827
 828         /*
 829          * Now that we are back to our own permissions, create ~/.ssh
 830          * directory if it doesn't already exist.
 831          */
 832         r = snprintf(buf, sizeof buf, "%s%s%s", pw->pw_dir,
 833             strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
 834         if (r > 0 && (size_t)r < sizeof(buf) && stat(buf, &st) < 0)
 835                 if (mkdir(buf, 0700) < 0)
 836                         error("Could not create directory '%.200s'.", buf);
 837
 838         /* load options.identity_files */
 839         load_public_identity_files();
 840
 841         /* Expand ~ in known host file names. */
 842         /* XXX mem-leaks: */
 843         options.system_hostfile =
 844             tilde_expand_filename(options.system_hostfile, original_real_uid);
 845         options.user_hostfile =
 846             tilde_expand_filename(options.user_hostfile, original_real_uid);
 847         options.system_hostfile2 =
 848             tilde_expand_filename(options.system_hostfile2, original_real_uid);
 849         options.user_hostfile2 =
 850             tilde_expand_filename(options.user_hostfile2, original_real_uid);
 851
 852         signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
 853
 854         /* Log into the remote system.  Never returns if the login fails. */
 855         ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
 856             pw, timeout_ms);
 857
 858         /* We no longer need the private host keys.  Clear them now. */
 859         if (sensitive_data.nkeys != 0) {
 860                 for (i = 0; i < sensitive_data.nkeys; i++) {
 861                         if (sensitive_data.keys[i] != NULL) {
 862                                 /* Destroys contents safely */
 863                                 debug3("clear hostkey %d", i);
 864                                 key_free(sensitive_data.keys[i]);
 865                                 sensitive_data.keys[i] = NULL;
 866                         }
 867                 }
 868                 xfree(sensitive_data.keys);
 869         }
 870         for (i = 0; i < options.num_identity_files; i++) {
 871                 if (options.identity_files[i]) {
 872                         xfree(options.identity_files[i]);
 873                         options.identity_files[i] = NULL;
 874                 }
 875                 if (options.identity_keys[i]) {
 876                         key_free(options.identity_keys[i]);
 877                         options.identity_keys[i] = NULL;
 878                 }
 879         }
 880
 881         exit_status = compat20 ? ssh_session2() : ssh_session();
 882         packet_close();
 883
 884         if (options.control_path != NULL && muxserver_sock != -1)
 885                 unlink(options.control_path);
 886
 887         /*
 888          * Send SIGHUP to proxy command if used. We don't wait() in
 889          * case it hangs and instead rely on init to reap the child
 890          */
 891         if (proxy_command_pid > 1)
 892                 kill(proxy_command_pid, SIGHUP);
 893
 894         return exit_status;
 895 }
 896
 897 /* Callback for remote forward global requests */
 898 static void
 899 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
 900 {
 901         Forward *rfwd = (Forward *)ctxt;
 902
 903         /* XXX verbose() on failure? */
 904         debug("remote forward %s for: listen %d, connect %s:%d",
 905             type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
 906             rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
 907         if (type == SSH2_MSG_REQUEST_SUCCESS && rfwd->listen_port == 0) {
 908                 logit("Allocated port %u for remote forward to %s:%d",
 909                         packet_get_int(),
 910                         rfwd->connect_host, rfwd->connect_port);
 911         }
 912
 913         if (type == SSH2_MSG_REQUEST_FAILURE) {
 914                 if (options.exit_on_forward_failure)
 915                         fatal("Error: remote port forwarding failed for "
 916                             "listen port %d", rfwd->listen_port);
 917                 else
 918                         logit("Warning: remote port forwarding failed for "
 919                             "listen port %d", rfwd->listen_port);
 920         }
 921         if (++remote_forward_confirms_received == options.num_remote_forwards) {
 922                 debug("All remote forwarding requests processed");
 923                 if (fork_after_authentication_flag) {
 924                         fork_after_authentication_flag = 0;
 925                         if (daemon(1, 1) < 0)
 926                                 fatal("daemon() failed: %.200s",
 927                                     strerror(errno));
 928                 }
 929         }
 930 }
 931
 932 static void
 933 client_cleanup_stdio_fwd(int id, void *arg)
 934 {
 935         debug("stdio forwarding: done");
 936         cleanup_exit(0);
 937 }
 938
 939 static int
 940 client_setup_stdio_fwd(const char *host_to_connect, u_short port_to_connect)
 941 {
 942         Channel *c;
 943         int in, out;
 944
 945         debug3("client_setup_stdio_fwd %s:%d", host_to_connect,
 946             port_to_connect);
 947
 948         in = dup(STDIN_FILENO);
 949         out = dup(STDOUT_FILENO);
 950         if (in < 0 || out < 0)
 951                 fatal("channel_connect_stdio_fwd: dup() in/out failed");
 952
 953         if ((c = channel_connect_stdio_fwd(host_to_connect, port_to_connect,
 954             in, out)) == NULL)
 955                 return 0;
 956         channel_register_cleanup(c->self, client_cleanup_stdio_fwd, 0);
 957         return 1;
 958 }
 959
 960 static void
 961 ssh_init_forwarding(void)
 962 {
 963         int success = 0;
 964         int i;
 965
 966         if (stdio_forward_host != NULL) {
 967                 if (!compat20) {
 968                         fatal("stdio forwarding require Protocol 2");
 969                 }
 970                 if (!client_setup_stdio_fwd(stdio_forward_host,
 971                     stdio_forward_port))
 972                         fatal("Failed to connect in stdio forward mode.");
 973         }
 974
 975         /* Initiate local TCP/IP port forwardings. */
 976         for (i = 0; i < options.num_local_forwards; i++) {
 977                 debug("Local connections to %.200s:%d forwarded to remote "
 978                     "address %.200s:%d",
 979                     (options.local_forwards[i].listen_host == NULL) ?
 980                     (options.gateway_ports ? "*" : "LOCALHOST") :
 981                     options.local_forwards[i].listen_host,
 982                     options.local_forwards[i].listen_port,
 983                     options.local_forwards[i].connect_host,
 984                     options.local_forwards[i].connect_port);
 985                 success += channel_setup_local_fwd_listener(
 986                     options.local_forwards[i].listen_host,
 987                     options.local_forwards[i].listen_port,
 988                     options.local_forwards[i].connect_host,
 989                     options.local_forwards[i].connect_port,
 990                     options.gateway_ports);
 991         }
 992         if (i > 0 && success != i && options.exit_on_forward_failure)
 993                 fatal("Could not request local forwarding.");
 994         if (i > 0 && success == 0)
 995                 error("Could not request local forwarding.");
 996
 997         /* Initiate remote TCP/IP port forwardings. */
 998         for (i = 0; i < options.num_remote_forwards; i++) {
 999                 debug("Remote connections from %.200s:%d forwarded to "
1000                     "local address %.200s:%d",
1001                     (options.remote_forwards[i].listen_host == NULL) ?
1002                     "LOCALHOST" : options.remote_forwards[i].listen_host,
1003                     options.remote_forwards[i].listen_port,
1004                     options.remote_forwards[i].connect_host,
1005                     options.remote_forwards[i].connect_port);
1006                 if (channel_request_remote_forwarding(
1007                     options.remote_forwards[i].listen_host,
1008                     options.remote_forwards[i].listen_port,
1009                     options.remote_forwards[i].connect_host,
1010                     options.remote_forwards[i].connect_port) < 0) {
1011                         if (options.exit_on_forward_failure)
1012                                 fatal("Could not request remote forwarding.");
1013                         else
1014                                 logit("Warning: Could not request remote "
1015                                     "forwarding.");
1016                 }
1017                 client_register_global_confirm(ssh_confirm_remote_forward,
1018                     &options.remote_forwards[i]);
1019         }
1020
1021         /* Initiate tunnel forwarding. */
1022         if (options.tun_open != SSH_TUNMODE_NO) {
1023                 if (client_request_tun_fwd(options.tun_open,
1024                     options.tun_local, options.tun_remote) == -1) {
1025                         if (options.exit_on_forward_failure)
1026                                 fatal("Could not request tunnel forwarding.");
1027                         else
1028                                 error("Could not request tunnel forwarding.");
1029                 }
1030         }
1031 }
1032
1033 static void
1034 check_agent_present(void)
1035 {
1036         if (options.forward_agent) {
1037                 /* Clear agent forwarding if we don't have an agent. */
1038                 if (!ssh_agent_present())
1039                         options.forward_agent = 0;
1040         }
1041 }
1042
1043 static int
1044 ssh_session(void)
1045 {
1046         int type;
1047         int interactive = 0;
1048         int have_tty = 0;
1049         struct winsize ws;
1050         char *cp;
1051         const char *display;
1052
1053         /* Enable compression if requested. */
1054         if (options.compression) {
1055                 debug("Requesting compression at level %d.",
1056                     options.compression_level);
1057
1058                 if (options.compression_level < 1 ||
1059                     options.compression_level > 9)
1060                         fatal("Compression level must be from 1 (fast) to "
1061                             "9 (slow, best).");
1062
1063                 /* Send the request. */
1064                 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
1065                 packet_put_int(options.compression_level);
1066                 packet_send();
1067                 packet_write_wait();
1068                 type = packet_read();
1069                 if (type == SSH_SMSG_SUCCESS)
1070                         packet_start_compression(options.compression_level);
1071                 else if (type == SSH_SMSG_FAILURE)
1072                         logit("Warning: Remote host refused compression.");
1073                 else
1074                         packet_disconnect("Protocol error waiting for "
1075                             "compression response.");
1076         }
1077         /* Allocate a pseudo tty if appropriate. */
1078         if (tty_flag) {
1079                 debug("Requesting pty.");
1080
1081                 /* Start the packet. */
1082                 packet_start(SSH_CMSG_REQUEST_PTY);
1083
1084                 /* Store TERM in the packet.  There is no limit on the
1085                    length of the string. */
1086                 cp = getenv("TERM");
1087                 if (!cp)
1088                         cp = "";
1089                 packet_put_cstring(cp);
1090
1091                 /* Store window size in the packet. */
1092                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
1093                         memset(&ws, 0, sizeof(ws));
1094                 packet_put_int((u_int)ws.ws_row);
1095                 packet_put_int((u_int)ws.ws_col);
1096                 packet_put_int((u_int)ws.ws_xpixel);
1097                 packet_put_int((u_int)ws.ws_ypixel);
1098
1099                 /* Store tty modes in the packet. */
1100                 tty_make_modes(fileno(stdin), NULL);
1101
1102                 /* Send the packet, and wait for it to leave. */
1103                 packet_send();
1104                 packet_write_wait();
1105
1106                 /* Read response from the server. */
1107                 type = packet_read();
1108                 if (type == SSH_SMSG_SUCCESS) {
1109                         interactive = 1;
1110                         have_tty = 1;
1111                 } else if (type == SSH_SMSG_FAILURE)
1112                         logit("Warning: Remote host failed or refused to "
1113                             "allocate a pseudo tty.");
1114                 else
1115                         packet_disconnect("Protocol error waiting for pty "
1116                             "request response.");
1117         }
1118         /* Request X11 forwarding if enabled and DISPLAY is set. */
1119         display = getenv("DISPLAY");
1120         if (options.forward_x11 && display != NULL) {
1121                 char *proto, *data;
1122                 /* Get reasonable local authentication information. */
1123                 client_x11_get_proto(display, options.xauth_location,
1124                     options.forward_x11_trusted, &proto, &data);
1125                 /* Request forwarding with authentication spoofing. */
1126                 debug("Requesting X11 forwarding with authentication "
1127                     "spoofing.");
1128                 x11_request_forwarding_with_spoofing(0, display, proto, data);
1129
1130                 /* Read response from the server. */
1131                 type = packet_read();
1132                 if (type == SSH_SMSG_SUCCESS) {
1133                         interactive = 1;
1134                 } else if (type == SSH_SMSG_FAILURE) {
1135                         logit("Warning: Remote host denied X11 forwarding.");
1136                 } else {
1137                         packet_disconnect("Protocol error waiting for X11 "
1138                             "forwarding");
1139                 }
1140         }
1141         /* Tell the packet module whether this is an interactive session. */
1142         packet_set_interactive(interactive);
1143
1144         /* Request authentication agent forwarding if appropriate. */
1145         check_agent_present();
1146
1147         if (options.forward_agent) {
1148                 debug("Requesting authentication agent forwarding.");
1149                 auth_request_forwarding();
1150
1151                 /* Read response from the server. */
1152                 type = packet_read();
1153                 packet_check_eom();
1154                 if (type != SSH_SMSG_SUCCESS)
1155                         logit("Warning: Remote host denied authentication agent forwarding.");
1156         }
1157
1158         /* Initiate port forwardings. */
1159         ssh_init_forwarding();
1160
1161         /* Execute a local command */
1162         if (options.local_command != NULL &&
1163             options.permit_local_command)
1164                 ssh_local_cmd(options.local_command);
1165
1166         /*
1167          * If requested and we are not interested in replies to remote
1168          * forwarding requests, then let ssh continue in the background.
1169          */
1170         if (fork_after_authentication_flag &&
1171             (!options.exit_on_forward_failure ||
1172             options.num_remote_forwards == 0)) {
1173                 fork_after_authentication_flag = 0;
1174                 if (daemon(1, 1) < 0)
1175                         fatal("daemon() failed: %.200s", strerror(errno));
1176         }
1177
1178         /*
1179          * If a command was specified on the command line, execute the
1180          * command now. Otherwise request the server to start a shell.
1181          */
1182         if (buffer_len(&command) > 0) {
1183                 int len = buffer_len(&command);
1184                 if (len > 900)
1185                         len = 900;
1186                 debug("Sending command: %.*s", len,
1187                     (u_char *)buffer_ptr(&command));
1188                 packet_start(SSH_CMSG_EXEC_CMD);
1189                 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1190                 packet_send();
1191                 packet_write_wait();
1192         } else {
1193                 debug("Requesting shell.");
1194                 packet_start(SSH_CMSG_EXEC_SHELL);
1195                 packet_send();
1196                 packet_write_wait();
1197         }
1198
1199         /* Enter the interactive session. */
1200         return client_loop(have_tty, tty_flag ?
1201             options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1202 }
1203
1204 /* request pty/x11/agent/tcpfwd/shell for channel */
1205 static void
1206 ssh_session2_setup(int id, void *arg)
1207 {
1208         extern char **environ;
1209         const char *display;
1210         int interactive = tty_flag;
1211
1212         display = getenv("DISPLAY");
1213         if (options.forward_x11 && display != NULL) {
1214                 char *proto, *data;
1215                 /* Get reasonable local authentication information. */
1216                 client_x11_get_proto(display, options.xauth_location,
1217                     options.forward_x11_trusted, &proto, &data);
1218                 /* Request forwarding with authentication spoofing. */
1219                 debug("Requesting X11 forwarding with authentication "
1220                     "spoofing.");
1221                 x11_request_forwarding_with_spoofing(id, display, proto, data);
1222                 interactive = 1;
1223                 /* XXX wait for reply */
1224         }
1225
1226         check_agent_present();
1227         if (options.forward_agent) {
1228                 debug("Requesting authentication agent forwarding.");
1229                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1230                 packet_send();
1231         }
1232
1233         client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1234             NULL, fileno(stdin), &command, environ);
1235
1236         packet_set_interactive(interactive);
1237 }
1238
1239 /* open new channel for a session */
1240 static int
1241 ssh_session2_open(void)
1242 {
1243         Channel *c;
1244         int window, packetmax, in, out, err;
1245
1246         if (stdin_null_flag) {
1247                 in = open(_PATH_DEVNULL, O_RDONLY);
1248         } else {
1249                 in = dup(STDIN_FILENO);
1250         }
1251         out = dup(STDOUT_FILENO);
1252         err = dup(STDERR_FILENO);
1253
1254         if (in < 0 || out < 0 || err < 0)
1255                 fatal("dup() in/out/err failed");
1256
1257         /* enable nonblocking unless tty */
1258         if (!isatty(in))
1259                 set_nonblock(in);
1260         if (!isatty(out))
1261                 set_nonblock(out);
1262         if (!isatty(err))
1263                 set_nonblock(err);
1264
1265         /*
1266          * We need to check to see what to do about buffer sizes here.
1267          * - In an HPN to non-HPN connection we want to limit the window size to
1268          *   something reasonable in case the far side has the large window bug.
1269          * - In an HPN to HPN connection we want to use the max window size but
1270          *   allow the user to override it.
1271          * - Lastly if HPN is disabled then use the ssh standard window size.
1272          *
1273          * We cannot just do a getsockopt() here and set the ssh window to that
1274          * as in case of autotuning of socket buffers the window would get stuck
1275          * at the initial buffer size, generally less than 96k.  Therefore we
1276          * need to set the maximum ssh window size to the maximum HPN buffer
1277          * size unless the user has set TcpRcvBufPoll to no.  In that case we
1278          * can just set the window to the minimum of HPN buffer size and TCP
1279          * receive buffer size.
1280          */
1281         if (tty_flag)
1282                 options.hpn_buffer_size = CHAN_SES_WINDOW_DEFAULT;
1283         else
1284                 options.hpn_buffer_size = CHAN_HPN_MIN_WINDOW_DEFAULT;
1285
1286         if (datafellows & SSH_BUG_LARGEWINDOW) {
1287                 debug("HPN to Non-HPN Connection");
1288         } else if (options.tcp_rcv_buf_poll <= 0) {
1289                 sock_get_rcvbuf(&options.hpn_buffer_size, 0);
1290                 debug("HPNBufferSize set to TCP RWIN: %d",
1291                     options.hpn_buffer_size);
1292         } else if (options.tcp_rcv_buf > 0) {
1293                 sock_get_rcvbuf(&options.hpn_buffer_size,
1294                     options.tcp_rcv_buf);
1295                 debug("HPNBufferSize set to user TCPRcvBuf: %d",
1296                     options.hpn_buffer_size);
1297         }
1298         debug("Final hpn_buffer_size = %d", options.hpn_buffer_size);
1299         channel_set_hpn(options.hpn_disabled, options.hpn_buffer_size);
1300         window = options.hpn_buffer_size;
1301
1302         packetmax = CHAN_SES_PACKET_DEFAULT;
1303         if (tty_flag) {
1304                 window = CHAN_SES_WINDOW_DEFAULT;
1305                 window >>= 1;
1306                 packetmax >>= 1;
1307         }
1308         c = channel_new(
1309             "session", SSH_CHANNEL_OPENING, in, out, err,
1310             window, packetmax, CHAN_EXTENDED_WRITE,
1311             "client-session", /*nonblock*/0);
1312         if (!options.hpn_disabled && options.tcp_rcv_buf_poll > 0) {
1313                 c->dynamic_window = 1;
1314                 debug("Enabled Dynamic Window Scaling\n");
1315         }
1316         debug3("ssh_session2_open: channel_new: %d", c->self);
1317
1318         channel_send_open(c->self);
1319         if (!no_shell_flag)
1320                 channel_register_open_confirm(c->self,
1321                     ssh_session2_setup, NULL);
1322
1323         return c->self;
1324 }
1325
1326 static int
1327 ssh_session2(void)
1328 {
1329         int id = -1;
1330
1331         /* XXX should be pre-session */
1332         ssh_init_forwarding();
1333
1334         if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1335                 id = ssh_session2_open();
1336
1337         /* If we don't expect to open a new session, then disallow it */
1338         if (options.control_master == SSHCTL_MASTER_NO &&
1339             (datafellows & SSH_NEW_OPENSSH)) {
1340                 debug("Requesting no-more-sessions@openssh.com");
1341                 packet_start(SSH2_MSG_GLOBAL_REQUEST);
1342                 packet_put_cstring("no-more-sessions@openssh.com");
1343                 packet_put_char(0);
1344                 packet_send();
1345         }
1346
1347         /* Execute a local command */
1348         if (options.local_command != NULL &&
1349             options.permit_local_command)
1350                 ssh_local_cmd(options.local_command);
1351
1352         /* Start listening for multiplex clients */
1353         muxserver_listen();
1354
1355         /* If requested, let ssh continue in the background. */
1356         if (fork_after_authentication_flag) {
1357                 fork_after_authentication_flag = 0;
1358                 if (daemon(1, 1) < 0)
1359                         fatal("daemon() failed: %.200s", strerror(errno));
1360         }
1361
1362         if (options.use_roaming)
1363                 request_roaming();
1364
1365         return client_loop(tty_flag, tty_flag ?
1366             options.escape_char : SSH_ESCAPECHAR_NONE, id);
1367 }
1368
1369 static void
1370 load_public_identity_files(void)
1371 {
1372         char *filename, *cp, thishost[NI_MAXHOST];
1373         char *pwdir = NULL, *pwname = NULL;
1374         int i = 0;
1375         Key *public;
1376         struct passwd *pw;
1377         u_int n_ids;
1378         char *identity_files[SSH_MAX_IDENTITY_FILES];
1379         Key *identity_keys[SSH_MAX_IDENTITY_FILES];
1380 #ifdef ENABLE_PKCS11
1381         Key **keys;
1382         int nkeys;
1383 #endif /* PKCS11 */
1384
1385         n_ids = 0;
1386         bzero(identity_files, sizeof(identity_files));
1387         bzero(identity_keys, sizeof(identity_keys));
1388
1389 #ifdef ENABLE_PKCS11
1390         if (options.pkcs11_provider != NULL &&
1391             options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1392             (pkcs11_init(!options.batch_mode) == 0) &&
1393             (nkeys = pkcs11_add_provider(options.pkcs11_provider, NULL,
1394             &keys)) > 0) {
1395                 for (i = 0; i < nkeys; i++) {
1396                         if (n_ids >= SSH_MAX_IDENTITY_FILES) {
1397                                 key_free(keys[i]);
1398                                 continue;
1399                         }
1400                         identity_keys[n_ids] = keys[i];
1401                         identity_files[n_ids] =
1402                             xstrdup(options.pkcs11_provider); /* XXX */
1403                         n_ids++;
1404                 }
1405                 xfree(keys);
1406         }
1407 #endif /* ENABLE_PKCS11 */
1408         if ((pw = getpwuid(original_real_uid)) == NULL)
1409                 fatal("load_public_identity_files: getpwuid failed");
1410         pwname = xstrdup(pw->pw_name);
1411         pwdir = xstrdup(pw->pw_dir);
1412         if (gethostname(thishost, sizeof(thishost)) == -1)
1413                 fatal("load_public_identity_files: gethostname: %s",
1414                     strerror(errno));
1415         for (i = 0; i < options.num_identity_files; i++) {
1416                 if (n_ids >= SSH_MAX_IDENTITY_FILES) {
1417                         xfree(options.identity_files[i]);
1418                         continue;
1419                 }
1420                 cp = tilde_expand_filename(options.identity_files[i],
1421                     original_real_uid);
1422                 filename = percent_expand(cp, "d", pwdir,
1423                     "u", pwname, "l", thishost, "h", host,
1424                     "r", options.user, (char *)NULL);
1425                 xfree(cp);
1426                 public = key_load_public(filename, NULL);
1427                 debug("identity file %s type %d", filename,
1428                     public ? public->type : -1);
1429                 xfree(options.identity_files[i]);
1430                 identity_files[n_ids] = filename;
1431                 identity_keys[n_ids] = public;
1432
1433                 if (++n_ids >= SSH_MAX_IDENTITY_FILES)
1434                         continue;
1435
1436                 /* Try to add the certificate variant too */
1437                 xasprintf(&cp, "%s-cert", filename);
1438                 public = key_load_public(cp, NULL);
1439                 debug("identity file %s type %d", cp,
1440                     public ? public->type : -1);
1441                 if (public == NULL) {
1442                         xfree(cp);
1443                         continue;
1444                 }
1445                 if (!key_is_cert(public)) {
1446                         debug("%s: key %s type %s is not a certificate",
1447                             __func__, cp, key_type(public));
1448                         key_free(public);
1449                         xfree(cp);
1450                         continue;
1451                 }
1452                 identity_keys[n_ids] = public;
1453                 /* point to the original path, most likely the private key */
1454                 identity_files[n_ids] = xstrdup(filename);
1455                 n_ids++;
1456         }
1457         options.num_identity_files = n_ids;
1458         memcpy(options.identity_files, identity_files, sizeof(identity_files));
1459         memcpy(options.identity_keys, identity_keys, sizeof(identity_keys));
1460
1461         bzero(pwname, strlen(pwname));
1462         xfree(pwname);
1463         bzero(pwdir, strlen(pwdir));
1464         xfree(pwdir);
1465 }