crypto/openssh-3.9p1/ssh.c

   1 /*
   2  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   3  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   4  *                    All rights reserved
   5  * Ssh client program.  This program can be used to log into a remote machine.
   6  * The software supports strong authentication, encryption, and forwarding
   7  * of X11, TCP/IP, and authentication connections.
   8  *
   9  * As far as I am concerned, the code I have written for this software
  10  * can be used freely for any purpose.  Any derived versions of this
  11  * software must be clearly marked as such, and if the derived work is
  12  * incompatible with the protocol description in the RFC file, it must be
  13  * called by a name other than "ssh" or "Secure Shell".
  14  *
  15  * Copyright (c) 1999 Niels Provos.  All rights reserved.
  16  * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl.  All rights reserved.
  17  *
  18  * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
  19  * in Canada (German citizen).
  20  *
  21  * Redistribution and use in source and binary forms, with or without
  22  * modification, are permitted provided that the following conditions
  23  * are met:
  24  * 1. Redistributions of source code must retain the above copyright
  25  *    notice, this list of conditions and the following disclaimer.
  26  * 2. Redistributions in binary form must reproduce the above copyright
  27  *    notice, this list of conditions and the following disclaimer in the
  28  *    documentation and/or other materials provided with the distribution.
  29  *
  30  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  31  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  32  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  33  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  34  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  35  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  36  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  37  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  38  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  39  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  40  */
  41
  42 #include "includes.h"
  43 RCSID("$OpenBSD: ssh.c,v 1.224 2004/07/28 09:40:29 markus Exp $");
  44
  45 #include <openssl/evp.h>
  46 #include <openssl/err.h>
  47
  48 #include "ssh.h"
  49 #include "ssh1.h"
  50 #include "ssh2.h"
  51 #include "compat.h"
  52 #include "cipher.h"
  53 #include "xmalloc.h"
  54 #include "packet.h"
  55 #include "buffer.h"
  56 #include "bufaux.h"
  57 #include "channels.h"
  58 #include "key.h"
  59 #include "authfd.h"
  60 #include "authfile.h"
  61 #include "pathnames.h"
  62 #include "dispatch.h"
  63 #include "clientloop.h"
  64 #include "log.h"
  65 #include "readconf.h"
  66 #include "sshconnect.h"
  67 #include "misc.h"
  68 #include "kex.h"
  69 #include "mac.h"
  70 #include "sshpty.h"
  71 #include "match.h"
  72 #include "msg.h"
  73 #include "monitor_fdpass.h"
  74 #include "uidswap.h"
  75
  76 #ifdef SMARTCARD
  77 #include "scard.h"
  78 #endif
  79
  80 extern char *__progname;
  81
  82 /* Flag indicating whether debug mode is on.  This can be set on the command line. */
  83 int debug_flag = 0;
  84
  85 /* Flag indicating whether a tty should be allocated */
  86 int tty_flag = 0;
  87 int no_tty_flag = 0;
  88 int force_tty_flag = 0;
  89
  90 /* don't exec a shell */
  91 int no_shell_flag = 0;
  92
  93 /*
  94  * Flag indicating that nothing should be read from stdin.  This can be set
  95  * on the command line.
  96  */
  97 int stdin_null_flag = 0;
  98
  99 /*
 100  * Flag indicating that ssh should fork after authentication.  This is useful
 101  * so that the passphrase can be entered manually, and then ssh goes to the
 102  * background.
 103  */
 104 int fork_after_authentication_flag = 0;
 105
 106 /*
 107  * General data structure for command line options and options configurable
 108  * in configuration files.  See readconf.h.
 109  */
 110 Options options;
 111
 112 /* optional user configfile */
 113 char *config = NULL;
 114
 115 /*
 116  * Name of the host we are connecting to.  This is the name given on the
 117  * command line, or the HostName specified for the user-supplied name in a
 118  * configuration file.
 119  */
 120 char *host;
 121
 122 /* socket address the host resolves to */
 123 struct sockaddr_storage hostaddr;
 124
 125 /* Private host keys. */
 126 Sensitive sensitive_data;
 127
 128 /* Original real UID. */
 129 uid_t original_real_uid;
 130 uid_t original_effective_uid;
 131
 132 /* command to be executed */
 133 Buffer command;
 134
 135 /* Should we execute a command or invoke a subsystem? */
 136 int subsystem_flag = 0;
 137
 138 /* # of replies received for global requests */
 139 static int client_global_request_id = 0;
 140
 141 /* pid of proxycommand child process */
 142 pid_t proxy_command_pid = 0;
 143
 144 /* fd to control socket */
 145 int control_fd = -1;
 146
 147 /* Only used in control client mode */
 148 volatile sig_atomic_t control_client_terminate = 0;
 149 u_int control_server_pid = 0;
 150
 151 /* Prints a help message to the user.  This function never returns. */
 152
 153 static void
 154 usage(void)
 155 {
 156         fprintf(stderr,
 157 "usage: ssh [-1246AaCfghkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n"
 158 "           [-D port] [-e escape_char] [-F configfile] [-i identity_file]\n"
 159 "           [-L port:host:hostport] [-l login_name] [-m mac_spec] [-o option]\n"
 160 "           [-p port] [-R port:host:hostport] [-S ctl] [user@]hostname [command]\n"
 161         );
 162         exit(1);
 163 }
 164
 165 static int ssh_session(void);
 166 static int ssh_session2(void);
 167 static void load_public_identity_files(void);
 168 static void control_client(const char *path);
 169
 170 /*
 171  * Main program for the ssh client.
 172  */
 173 int
 174 main(int ac, char **av)
 175 {
 176         int i, opt, exit_status;
 177         u_short fwd_port, fwd_host_port;
 178         char sfwd_port[6], sfwd_host_port[6];
 179         char *p, *cp, *line, buf[256];
 180         struct stat st;
 181         struct passwd *pw;
 182         int dummy;
 183         extern int optind, optreset;
 184         extern char *optarg;
 185
 186         __progname = ssh_get_progname(av[0]);
 187         init_rng();
 188
 189         /*
 190          * Save the original real uid.  It will be needed later (uid-swapping
 191          * may clobber the real uid).
 192          */
 193         original_real_uid = getuid();
 194         original_effective_uid = geteuid();
 195
 196         /*
 197          * Use uid-swapping to give up root privileges for the duration of
 198          * option processing.  We will re-instantiate the rights when we are
 199          * ready to create the privileged port, and will permanently drop
 200          * them when the port has been created (actually, when the connection
 201          * has been made, as we may need to create the port several times).
 202          */
 203         PRIV_END;
 204
 205 #ifdef HAVE_SETRLIMIT
 206         /* If we are installed setuid root be careful to not drop core. */
 207         if (original_real_uid != original_effective_uid) {
 208                 struct rlimit rlim;
 209                 rlim.rlim_cur = rlim.rlim_max = 0;
 210                 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
 211                         fatal("setrlimit failed: %.100s", strerror(errno));
 212         }
 213 #endif
 214         /* Get user data. */
 215         pw = getpwuid(original_real_uid);
 216         if (!pw) {
 217                 logit("You don't exist, go away!");
 218                 exit(1);
 219         }
 220         /* Take a copy of the returned structure. */
 221         pw = pwcopy(pw);
 222
 223         /*
 224          * Set our umask to something reasonable, as some files are created
 225          * with the default umask.  This will make them world-readable but
 226          * writable only by the owner, which is ok for all files for which we
 227          * don't set the modes explicitly.
 228          */
 229         umask(022);
 230
 231         /* Initialize option structure to indicate that no values have been set. */
 232         initialize_options(&options);
 233
 234         /* Parse command-line arguments. */
 235         host = NULL;
 236
 237 again:
 238         while ((opt = getopt(ac, av,
 239             "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNPR:S:TVXY")) != -1) {
 240                 switch (opt) {
 241                 case '1':
 242                         options.protocol = SSH_PROTO_1;
 243                         break;
 244                 case '2':
 245                         options.protocol = SSH_PROTO_2;
 246                         break;
 247                 case '4':
 248                         options.address_family = AF_INET;
 249                         break;
 250                 case '6':
 251                         options.address_family = AF_INET6;
 252                         break;
 253                 case 'n':
 254                         stdin_null_flag = 1;
 255                         break;
 256                 case 'f':
 257                         fork_after_authentication_flag = 1;
 258                         stdin_null_flag = 1;
 259                         break;
 260                 case 'x':
 261                         options.forward_x11 = 0;
 262                         break;
 263                 case 'X':
 264                         options.forward_x11 = 1;
 265                         break;
 266                 case 'Y':
 267                         options.forward_x11 = 1;
 268                         options.forward_x11_trusted = 1;
 269                         break;
 270                 case 'g':
 271                         options.gateway_ports = 1;
 272                         break;
 273                 case 'P':       /* deprecated */
 274                         options.use_privileged_port = 0;
 275                         break;
 276                 case 'a':
 277                         options.forward_agent = 0;
 278                         break;
 279                 case 'A':
 280                         options.forward_agent = 1;
 281                         break;
 282                 case 'k':
 283                         options.gss_deleg_creds = 0;
 284                         break;
 285                 case 'i':
 286                         if (stat(optarg, &st) < 0) {
 287                                 fprintf(stderr, "Warning: Identity file %s "
 288                                     "does not exist.\n", optarg);
 289                                 break;
 290                         }
 291                         if (options.num_identity_files >=
 292                             SSH_MAX_IDENTITY_FILES)
 293                                 fatal("Too many identity files specified "
 294                                     "(max %d)", SSH_MAX_IDENTITY_FILES);
 295                         options.identity_files[options.num_identity_files++] =
 296                             xstrdup(optarg);
 297                         break;
 298                 case 'I':
 299 #ifdef SMARTCARD
 300                         options.smartcard_device = xstrdup(optarg);
 301 #else
 302                         fprintf(stderr, "no support for smartcards.\n");
 303 #endif
 304                         break;
 305                 case 't':
 306                         if (tty_flag)
 307                                 force_tty_flag = 1;
 308                         tty_flag = 1;
 309                         break;
 310                 case 'v':
 311                         if (debug_flag == 0) {
 312                                 debug_flag = 1;
 313                                 options.log_level = SYSLOG_LEVEL_DEBUG1;
 314                         } else {
 315                                 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
 316                                         options.log_level++;
 317                                 break;
 318                         }
 319                         /* fallthrough */
 320                 case 'V':
 321                         fprintf(stderr, "%s, %s\n",
 322                             SSH_VERSION, SSLeay_version(SSLEAY_VERSION));
 323                         if (opt == 'V')
 324                                 exit(0);
 325                         break;
 326                 case 'q':
 327                         options.log_level = SYSLOG_LEVEL_QUIET;
 328                         break;
 329                 case 'e':
 330                         if (optarg[0] == '^' && optarg[2] == 0 &&
 331                             (u_char) optarg[1] >= 64 &&
 332                             (u_char) optarg[1] < 128)
 333                                 options.escape_char = (u_char) optarg[1] & 31;
 334                         else if (strlen(optarg) == 1)
 335                                 options.escape_char = (u_char) optarg[0];
 336                         else if (strcmp(optarg, "none") == 0)
 337                                 options.escape_char = SSH_ESCAPECHAR_NONE;
 338                         else {
 339                                 fprintf(stderr, "Bad escape character '%s'.\n",
 340                                     optarg);
 341                                 exit(1);
 342                         }
 343                         break;
 344                 case 'c':
 345                         if (ciphers_valid(optarg)) {
 346                                 /* SSH2 only */
 347                                 options.ciphers = xstrdup(optarg);
 348                                 options.cipher = SSH_CIPHER_INVALID;
 349                         } else {
 350                                 /* SSH1 only */
 351                                 options.cipher = cipher_number(optarg);
 352                                 if (options.cipher == -1) {
 353                                         fprintf(stderr,
 354                                             "Unknown cipher type '%s'\n",
 355                                             optarg);
 356                                         exit(1);
 357                                 }
 358                                 if (options.cipher == SSH_CIPHER_3DES)
 359                                         options.ciphers = "3des-cbc";
 360                                 else if (options.cipher == SSH_CIPHER_BLOWFISH)
 361                                         options.ciphers = "blowfish-cbc";
 362                                 else
 363                                         options.ciphers = (char *)-1;
 364                         }
 365                         break;
 366                 case 'm':
 367                         if (mac_valid(optarg))
 368                                 options.macs = xstrdup(optarg);
 369                         else {
 370                                 fprintf(stderr, "Unknown mac type '%s'\n",
 371                                     optarg);
 372                                 exit(1);
 373                         }
 374                         break;
 375                 case 'M':
 376                         options.control_master =
 377                             (options.control_master >= 1) ? 2 : 1;
 378                         break;
 379                 case 'p':
 380                         options.port = a2port(optarg);
 381                         if (options.port == 0) {
 382                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 383                                 exit(1);
 384                         }
 385                         break;
 386                 case 'l':
 387                         options.user = optarg;
 388                         break;
 389
 390                 case 'L':
 391                 case 'R':
 392                         if (sscanf(optarg, "%5[0123456789]:%255[^:]:%5[0123456789]",
 393                             sfwd_port, buf, sfwd_host_port) != 3 &&
 394                             sscanf(optarg, "%5[0123456789]/%255[^/]/%5[0123456789]",
 395                             sfwd_port, buf, sfwd_host_port) != 3) {
 396                                 fprintf(stderr,
 397                                     "Bad forwarding specification '%s'\n",
 398                                     optarg);
 399                                 usage();
 400                                 /* NOTREACHED */
 401                         }
 402                         if ((fwd_port = a2port(sfwd_port)) == 0 ||
 403                             (fwd_host_port = a2port(sfwd_host_port)) == 0) {
 404                                 fprintf(stderr,
 405                                     "Bad forwarding port(s) '%s'\n", optarg);
 406                                 exit(1);
 407                         }
 408                         if (opt == 'L')
 409                                 add_local_forward(&options, fwd_port, buf,
 410                                     fwd_host_port);
 411                         else if (opt == 'R')
 412                                 add_remote_forward(&options, fwd_port, buf,
 413                                     fwd_host_port);
 414                         break;
 415
 416                 case 'D':
 417                         fwd_port = a2port(optarg);
 418                         if (fwd_port == 0) {
 419                                 fprintf(stderr, "Bad dynamic port '%s'\n",
 420                                     optarg);
 421                                 exit(1);
 422                         }
 423                         add_local_forward(&options, fwd_port, "socks", 0);
 424                         break;
 425
 426                 case 'C':
 427                         options.compression = 1;
 428                         break;
 429                 case 'N':
 430                         no_shell_flag = 1;
 431                         no_tty_flag = 1;
 432                         break;
 433                 case 'T':
 434                         no_tty_flag = 1;
 435                         break;
 436                 case 'o':
 437                         dummy = 1;
 438                         line = xstrdup(optarg);
 439                         if (process_config_line(&options, host ? host : "",
 440                             line, "command-line", 0, &dummy) != 0)
 441                                 exit(1);
 442                         xfree(line);
 443                         break;
 444                 case 's':
 445                         subsystem_flag = 1;
 446                         break;
 447                 case 'S':
 448                         if (options.control_path != NULL)
 449                                 free(options.control_path);
 450                         options.control_path = xstrdup(optarg);
 451                         break;
 452                 case 'b':
 453                         options.bind_address = optarg;
 454                         break;
 455                 case 'F':
 456                         config = optarg;
 457                         break;
 458                 default:
 459                         usage();
 460                 }
 461         }
 462
 463         ac -= optind;
 464         av += optind;
 465
 466         if (ac > 0 && !host && **av != '-') {
 467                 if (strrchr(*av, '@')) {
 468                         p = xstrdup(*av);
 469                         cp = strrchr(p, '@');
 470                         if (cp == NULL || cp == p)
 471                                 usage();
 472                         options.user = p;
 473                         *cp = '\0';
 474                         host = ++cp;
 475                 } else
 476                         host = *av;
 477                 if (ac > 1) {
 478                         optind = optreset = 1;
 479                         goto again;
 480                 }
 481                 ac--, av++;
 482         }
 483
 484         /* Check that we got a host name. */
 485         if (!host)
 486                 usage();
 487
 488         SSLeay_add_all_algorithms();
 489         ERR_load_crypto_strings();
 490
 491         /* Initialize the command to execute on remote host. */
 492         buffer_init(&command);
 493
 494         /*
 495          * Save the command to execute on the remote host in a buffer. There
 496          * is no limit on the length of the command, except by the maximum
 497          * packet size.  Also sets the tty flag if there is no command.
 498          */
 499         if (!ac) {
 500                 /* No command specified - execute shell on a tty. */
 501                 tty_flag = 1;
 502                 if (subsystem_flag) {
 503                         fprintf(stderr,
 504                             "You must specify a subsystem to invoke.\n");
 505                         usage();
 506                 }
 507         } else {
 508                 /* A command has been specified.  Store it into the buffer. */
 509                 for (i = 0; i < ac; i++) {
 510                         if (i)
 511                                 buffer_append(&command, " ", 1);
 512                         buffer_append(&command, av[i], strlen(av[i]));
 513                 }
 514         }
 515
 516         /* Cannot fork to background if no command. */
 517         if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag)
 518                 fatal("Cannot fork into background without a command to execute.");
 519
 520         /* Allocate a tty by default if no command specified. */
 521         if (buffer_len(&command) == 0)
 522                 tty_flag = 1;
 523
 524         /* Force no tty */
 525         if (no_tty_flag)
 526                 tty_flag = 0;
 527         /* Do not allocate a tty if stdin is not a tty. */
 528         if (!isatty(fileno(stdin)) && !force_tty_flag) {
 529                 if (tty_flag)
 530                         logit("Pseudo-terminal will not be allocated because stdin is not a terminal.");
 531                 tty_flag = 0;
 532         }
 533
 534         /*
 535          * Initialize "log" output.  Since we are the client all output
 536          * actually goes to stderr.
 537          */
 538         log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
 539             SYSLOG_FACILITY_USER, 1);
 540
 541         /*
 542          * Read per-user configuration file.  Ignore the system wide config
 543          * file if the user specifies a config file on the command line.
 544          */
 545         if (config != NULL) {
 546                 if (!read_config_file(config, host, &options, 0))
 547                         fatal("Can't open user config file %.100s: "
 548                             "%.100s", config, strerror(errno));
 549         } else  {
 550                 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
 551                     _PATH_SSH_USER_CONFFILE);
 552                 (void)read_config_file(buf, host, &options, 1);
 553
 554                 /* Read systemwide configuration file after use config. */
 555                 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
 556                     &options, 0);
 557         }
 558
 559         /* Fill configuration defaults. */
 560         fill_default_options(&options);
 561
 562         channel_set_af(options.address_family);
 563
 564         /* reinit */
 565         log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1);
 566
 567         seed_rng();
 568
 569         if (options.user == NULL)
 570                 options.user = xstrdup(pw->pw_name);
 571
 572         if (options.hostname != NULL)
 573                 host = options.hostname;
 574
 575         /* force lowercase for hostkey matching */
 576         if (options.host_key_alias != NULL) {
 577                 for (p = options.host_key_alias; *p; p++)
 578                         if (isupper(*p))
 579                                 *p = tolower(*p);
 580         }
 581
 582         if (options.proxy_command != NULL &&
 583             strcmp(options.proxy_command, "none") == 0)
 584                 options.proxy_command = NULL;
 585
 586         if (options.control_path != NULL) {
 587                 options.control_path = tilde_expand_filename(
 588                    options.control_path, original_real_uid);
 589         }
 590         if (options.control_path != NULL && options.control_master == 0)
 591                 control_client(options.control_path); /* This doesn't return */
 592
 593         /* Open a connection to the remote host. */
 594         if (ssh_connect(host, &hostaddr, options.port,
 595             options.address_family, options.connection_attempts,
 596 #ifdef HAVE_CYGWIN
 597             options.use_privileged_port,
 598 #else
 599             original_effective_uid == 0 && options.use_privileged_port,
 600 #endif
 601             options.proxy_command) != 0)
 602                 exit(1);
 603
 604         /*
 605          * If we successfully made the connection, load the host private key
 606          * in case we will need it later for combined rsa-rhosts
 607          * authentication. This must be done before releasing extra
 608          * privileges, because the file is only readable by root.
 609          * If we cannot access the private keys, load the public keys
 610          * instead and try to execute the ssh-keysign helper instead.
 611          */
 612         sensitive_data.nkeys = 0;
 613         sensitive_data.keys = NULL;
 614         sensitive_data.external_keysign = 0;
 615         if (options.rhosts_rsa_authentication ||
 616             options.hostbased_authentication) {
 617                 sensitive_data.nkeys = 3;
 618                 sensitive_data.keys = xmalloc(sensitive_data.nkeys *
 619                     sizeof(Key));
 620
 621                 PRIV_START;
 622                 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
 623                     _PATH_HOST_KEY_FILE, "", NULL);
 624                 sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
 625                     _PATH_HOST_DSA_KEY_FILE, "", NULL);
 626                 sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
 627                     _PATH_HOST_RSA_KEY_FILE, "", NULL);
 628                 PRIV_END;
 629
 630                 if (options.hostbased_authentication == 1 &&
 631                     sensitive_data.keys[0] == NULL &&
 632                     sensitive_data.keys[1] == NULL &&
 633                     sensitive_data.keys[2] == NULL) {
 634                         sensitive_data.keys[1] = key_load_public(
 635                             _PATH_HOST_DSA_KEY_FILE, NULL);
 636                         sensitive_data.keys[2] = key_load_public(
 637                             _PATH_HOST_RSA_KEY_FILE, NULL);
 638                         sensitive_data.external_keysign = 1;
 639                 }
 640         }
 641         /*
 642          * Get rid of any extra privileges that we may have.  We will no
 643          * longer need them.  Also, extra privileges could make it very hard
 644          * to read identity files and other non-world-readable files from the
 645          * user's home directory if it happens to be on a NFS volume where
 646          * root is mapped to nobody.
 647          */
 648         if (original_effective_uid == 0) {
 649                 PRIV_START;
 650                 permanently_set_uid(pw);
 651         }
 652
 653         /*
 654          * Now that we are back to our own permissions, create ~/.ssh
 655          * directory if it doesn\'t already exist.
 656          */
 657         snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
 658         if (stat(buf, &st) < 0)
 659                 if (mkdir(buf, 0700) < 0)
 660                         error("Could not create directory '%.200s'.", buf);
 661
 662         /* load options.identity_files */
 663         load_public_identity_files();
 664
 665         /* Expand ~ in known host file names. */
 666         /* XXX mem-leaks: */
 667         options.system_hostfile =
 668             tilde_expand_filename(options.system_hostfile, original_real_uid);
 669         options.user_hostfile =
 670             tilde_expand_filename(options.user_hostfile, original_real_uid);
 671         options.system_hostfile2 =
 672             tilde_expand_filename(options.system_hostfile2, original_real_uid);
 673         options.user_hostfile2 =
 674             tilde_expand_filename(options.user_hostfile2, original_real_uid);
 675
 676         signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
 677
 678         /* Log into the remote system.  This never returns if the login fails. */
 679         ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw);
 680
 681         /* We no longer need the private host keys.  Clear them now. */
 682         if (sensitive_data.nkeys != 0) {
 683                 for (i = 0; i < sensitive_data.nkeys; i++) {
 684                         if (sensitive_data.keys[i] != NULL) {
 685                                 /* Destroys contents safely */
 686                                 debug3("clear hostkey %d", i);
 687                                 key_free(sensitive_data.keys[i]);
 688                                 sensitive_data.keys[i] = NULL;
 689                         }
 690                 }
 691                 xfree(sensitive_data.keys);
 692         }
 693         for (i = 0; i < options.num_identity_files; i++) {
 694                 if (options.identity_files[i]) {
 695                         xfree(options.identity_files[i]);
 696                         options.identity_files[i] = NULL;
 697                 }
 698                 if (options.identity_keys[i]) {
 699                         key_free(options.identity_keys[i]);
 700                         options.identity_keys[i] = NULL;
 701                 }
 702         }
 703
 704         exit_status = compat20 ? ssh_session2() : ssh_session();
 705         packet_close();
 706
 707         if (options.control_path != NULL && control_fd != -1)
 708                 unlink(options.control_path);
 709
 710         /*
 711          * Send SIGHUP to proxy command if used. We don't wait() in
 712          * case it hangs and instead rely on init to reap the child
 713          */
 714         if (proxy_command_pid > 1)
 715                 kill(proxy_command_pid, SIGHUP);
 716
 717         return exit_status;
 718 }
 719
 720 #define SSH_X11_PROTO "MIT-MAGIC-COOKIE-1"
 721
 722 static void
 723 x11_get_proto(char **_proto, char **_data)
 724 {
 725         char cmd[1024];
 726         char line[512];
 727         char xdisplay[512];
 728         static char proto[512], data[512];
 729         FILE *f;
 730         int got_data = 0, generated = 0, do_unlink = 0, i;
 731         char *display, *xauthdir, *xauthfile;
 732         struct stat st;
 733
 734         xauthdir = xauthfile = NULL;
 735         *_proto = proto;
 736         *_data = data;
 737         proto[0] = data[0] = '\0';
 738
 739         if (!options.xauth_location ||
 740             (stat(options.xauth_location, &st) == -1)) {
 741                 debug("No xauth program.");
 742         } else {
 743                 if ((display = getenv("DISPLAY")) == NULL) {
 744                         debug("x11_get_proto: DISPLAY not set");
 745                         return;
 746                 }
 747                 /*
 748                  * Handle FamilyLocal case where $DISPLAY does
 749                  * not match an authorization entry.  For this we
 750                  * just try "xauth list unix:displaynum.screennum".
 751                  * XXX: "localhost" match to determine FamilyLocal
 752                  *      is not perfect.
 753                  */
 754                 if (strncmp(display, "localhost:", 10) == 0) {
 755                         snprintf(xdisplay, sizeof(xdisplay), "unix:%s",
 756                             display + 10);
 757                         display = xdisplay;
 758                 }
 759                 if (options.forward_x11_trusted == 0) {
 760                         xauthdir = xmalloc(MAXPATHLEN);
 761                         xauthfile = xmalloc(MAXPATHLEN);
 762                         strlcpy(xauthdir, "/tmp/ssh-XXXXXXXXXX", MAXPATHLEN);
 763                         if (mkdtemp(xauthdir) != NULL) {
 764                                 do_unlink = 1;
 765                                 snprintf(xauthfile, MAXPATHLEN, "%s/xauthfile",
 766                                     xauthdir);
 767                                 snprintf(cmd, sizeof(cmd),
 768                                     "%s -f %s generate %s " SSH_X11_PROTO
 769                                     " untrusted timeout 1200 2>" _PATH_DEVNULL,
 770                                     options.xauth_location, xauthfile, display);
 771                                 debug2("x11_get_proto: %s", cmd);
 772                                 if (system(cmd) == 0)
 773                                         generated = 1;
 774                         }
 775                 }
 776                 snprintf(cmd, sizeof(cmd),
 777                     "%s %s%s list %s . 2>" _PATH_DEVNULL,
 778                     options.xauth_location,
 779                     generated ? "-f " : "" ,
 780                     generated ? xauthfile : "",
 781                     display);
 782                 debug2("x11_get_proto: %s", cmd);
 783                 f = popen(cmd, "r");
 784                 if (f && fgets(line, sizeof(line), f) &&
 785                     sscanf(line, "%*s %511s %511s", proto, data) == 2)
 786                         got_data = 1;
 787                 if (f)
 788                         pclose(f);
 789         }
 790
 791         if (do_unlink) {
 792                 unlink(xauthfile);
 793                 rmdir(xauthdir);
 794         }
 795         if (xauthdir)
 796                 xfree(xauthdir);
 797         if (xauthfile)
 798                 xfree(xauthfile);
 799
 800         /*
 801          * If we didn't get authentication data, just make up some
 802          * data.  The forwarding code will check the validity of the
 803          * response anyway, and substitute this data.  The X11
 804          * server, however, will ignore this fake data and use
 805          * whatever authentication mechanisms it was using otherwise
 806          * for the local connection.
 807          */
 808         if (!got_data) {
 809                 u_int32_t rnd = 0;
 810
 811                 logit("Warning: No xauth data; "
 812                     "using fake authentication data for X11 forwarding.");
 813                 strlcpy(proto, SSH_X11_PROTO, sizeof proto);
 814                 for (i = 0; i < 16; i++) {
 815                         if (i % 4 == 0)
 816                                 rnd = arc4random();
 817                         snprintf(data + 2 * i, sizeof data - 2 * i, "%02x",
 818                             rnd & 0xff);
 819                         rnd >>= 8;
 820                 }
 821         }
 822 }
 823
 824 static void
 825 ssh_init_forwarding(void)
 826 {
 827         int success = 0;
 828         int i;
 829
 830         /* Initiate local TCP/IP port forwardings. */
 831         for (i = 0; i < options.num_local_forwards; i++) {
 832                 debug("Connections to local port %d forwarded to remote address %.200s:%d",
 833                     options.local_forwards[i].port,
 834                     options.local_forwards[i].host,
 835                     options.local_forwards[i].host_port);
 836                 success += channel_setup_local_fwd_listener(
 837                     options.local_forwards[i].port,
 838                     options.local_forwards[i].host,
 839                     options.local_forwards[i].host_port,
 840                     options.gateway_ports);
 841         }
 842         if (i > 0 && success == 0)
 843                 error("Could not request local forwarding.");
 844
 845         /* Initiate remote TCP/IP port forwardings. */
 846         for (i = 0; i < options.num_remote_forwards; i++) {
 847                 debug("Connections to remote port %d forwarded to local address %.200s:%d",
 848                     options.remote_forwards[i].port,
 849                     options.remote_forwards[i].host,
 850                     options.remote_forwards[i].host_port);
 851                 channel_request_remote_forwarding(
 852                     options.remote_forwards[i].port,
 853                     options.remote_forwards[i].host,
 854                     options.remote_forwards[i].host_port);
 855         }
 856 }
 857
 858 static void
 859 check_agent_present(void)
 860 {
 861         if (options.forward_agent) {
 862                 /* Clear agent forwarding if we don\'t have an agent. */
 863                 if (!ssh_agent_present())
 864                         options.forward_agent = 0;
 865         }
 866 }
 867
 868 static int
 869 ssh_session(void)
 870 {
 871         int type;
 872         int interactive = 0;
 873         int have_tty = 0;
 874         struct winsize ws;
 875         char *cp;
 876
 877         /* Enable compression if requested. */
 878         if (options.compression) {
 879                 debug("Requesting compression at level %d.", options.compression_level);
 880
 881                 if (options.compression_level < 1 || options.compression_level > 9)
 882                         fatal("Compression level must be from 1 (fast) to 9 (slow, best).");
 883
 884                 /* Send the request. */
 885                 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
 886                 packet_put_int(options.compression_level);
 887                 packet_send();
 888                 packet_write_wait();
 889                 type = packet_read();
 890                 if (type == SSH_SMSG_SUCCESS)
 891                         packet_start_compression(options.compression_level);
 892                 else if (type == SSH_SMSG_FAILURE)
 893                         logit("Warning: Remote host refused compression.");
 894                 else
 895                         packet_disconnect("Protocol error waiting for compression response.");
 896         }
 897         /* Allocate a pseudo tty if appropriate. */
 898         if (tty_flag) {
 899                 debug("Requesting pty.");
 900
 901                 /* Start the packet. */
 902                 packet_start(SSH_CMSG_REQUEST_PTY);
 903
 904                 /* Store TERM in the packet.  There is no limit on the
 905                    length of the string. */
 906                 cp = getenv("TERM");
 907                 if (!cp)
 908                         cp = "";
 909                 packet_put_cstring(cp);
 910
 911                 /* Store window size in the packet. */
 912                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
 913                         memset(&ws, 0, sizeof(ws));
 914                 packet_put_int(ws.ws_row);
 915                 packet_put_int(ws.ws_col);
 916                 packet_put_int(ws.ws_xpixel);
 917                 packet_put_int(ws.ws_ypixel);
 918
 919                 /* Store tty modes in the packet. */
 920                 tty_make_modes(fileno(stdin), NULL);
 921
 922                 /* Send the packet, and wait for it to leave. */
 923                 packet_send();
 924                 packet_write_wait();
 925
 926                 /* Read response from the server. */
 927                 type = packet_read();
 928                 if (type == SSH_SMSG_SUCCESS) {
 929                         interactive = 1;
 930                         have_tty = 1;
 931                 } else if (type == SSH_SMSG_FAILURE)
 932                         logit("Warning: Remote host failed or refused to allocate a pseudo tty.");
 933                 else
 934                         packet_disconnect("Protocol error waiting for pty request response.");
 935         }
 936         /* Request X11 forwarding if enabled and DISPLAY is set. */
 937         if (options.forward_x11 && getenv("DISPLAY") != NULL) {
 938                 char *proto, *data;
 939                 /* Get reasonable local authentication information. */
 940                 x11_get_proto(&proto, &data);
 941                 /* Request forwarding with authentication spoofing. */
 942                 debug("Requesting X11 forwarding with authentication spoofing.");
 943                 x11_request_forwarding_with_spoofing(0, proto, data);
 944
 945                 /* Read response from the server. */
 946                 type = packet_read();
 947                 if (type == SSH_SMSG_SUCCESS) {
 948                         interactive = 1;
 949                 } else if (type == SSH_SMSG_FAILURE) {
 950                         logit("Warning: Remote host denied X11 forwarding.");
 951                 } else {
 952                         packet_disconnect("Protocol error waiting for X11 forwarding");
 953                 }
 954         }
 955         /* Tell the packet module whether this is an interactive session. */
 956         packet_set_interactive(interactive);
 957
 958         /* Request authentication agent forwarding if appropriate. */
 959         check_agent_present();
 960
 961         if (options.forward_agent) {
 962                 debug("Requesting authentication agent forwarding.");
 963                 auth_request_forwarding();
 964
 965                 /* Read response from the server. */
 966                 type = packet_read();
 967                 packet_check_eom();
 968                 if (type != SSH_SMSG_SUCCESS)
 969                         logit("Warning: Remote host denied authentication agent forwarding.");
 970         }
 971
 972         /* Initiate port forwardings. */
 973         ssh_init_forwarding();
 974
 975         /* If requested, let ssh continue in the background. */
 976         if (fork_after_authentication_flag)
 977                 if (daemon(1, 1) < 0)
 978                         fatal("daemon() failed: %.200s", strerror(errno));
 979
 980         /*
 981          * If a command was specified on the command line, execute the
 982          * command now. Otherwise request the server to start a shell.
 983          */
 984         if (buffer_len(&command) > 0) {
 985                 int len = buffer_len(&command);
 986                 if (len > 900)
 987                         len = 900;
 988                 debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command));
 989                 packet_start(SSH_CMSG_EXEC_CMD);
 990                 packet_put_string(buffer_ptr(&command), buffer_len(&command));
 991                 packet_send();
 992                 packet_write_wait();
 993         } else {
 994                 debug("Requesting shell.");
 995                 packet_start(SSH_CMSG_EXEC_SHELL);
 996                 packet_send();
 997                 packet_write_wait();
 998         }
 999
1000         /* Enter the interactive session. */
1001         return client_loop(have_tty, tty_flag ?
1002             options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1003 }
1004
1005 static void
1006 ssh_subsystem_reply(int type, u_int32_t seq, void *ctxt)
1007 {
1008         int id, len;
1009
1010         id = packet_get_int();
1011         len = buffer_len(&command);
1012         if (len > 900)
1013                 len = 900;
1014         packet_check_eom();
1015         if (type == SSH2_MSG_CHANNEL_FAILURE)
1016                 fatal("Request for subsystem '%.*s' failed on channel %d",
1017                     len, (u_char *)buffer_ptr(&command), id);
1018 }
1019
1020 void
1021 client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt)
1022 {
1023         int i;
1024
1025         i = client_global_request_id++;
1026         if (i >= options.num_remote_forwards)
1027                 return;
1028         debug("remote forward %s for: listen %d, connect %s:%d",
1029             type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1030             options.remote_forwards[i].port,
1031             options.remote_forwards[i].host,
1032             options.remote_forwards[i].host_port);
1033         if (type == SSH2_MSG_REQUEST_FAILURE)
1034                 logit("Warning: remote port forwarding failed for listen port %d",
1035                     options.remote_forwards[i].port);
1036 }
1037
1038 static void
1039 ssh_control_listener(void)
1040 {
1041         struct sockaddr_un addr;
1042         mode_t old_umask;
1043         int addr_len;
1044
1045         if (options.control_path == NULL || options.control_master <= 0)
1046                 return;
1047
1048         memset(&addr, '\0', sizeof(addr));
1049         addr.sun_family = AF_UNIX;
1050         addr_len = offsetof(struct sockaddr_un, sun_path) +
1051             strlen(options.control_path) + 1;
1052
1053         if (strlcpy(addr.sun_path, options.control_path,
1054             sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1055                 fatal("ControlPath too long");
1056
1057         if ((control_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1058                 fatal("%s socket(): %s\n", __func__, strerror(errno));
1059
1060         old_umask = umask(0177);
1061         if (bind(control_fd, (struct sockaddr*)&addr, addr_len) == -1) {
1062                 control_fd = -1;
1063                 if (errno == EINVAL)
1064                         fatal("ControlSocket %s already exists",
1065                             options.control_path);
1066                 else
1067                         fatal("%s bind(): %s\n", __func__, strerror(errno));
1068         }
1069         umask(old_umask);
1070
1071         if (listen(control_fd, 64) == -1)
1072                 fatal("%s listen(): %s\n", __func__, strerror(errno));
1073
1074         set_nonblock(control_fd);
1075 }
1076
1077 /* request pty/x11/agent/tcpfwd/shell for channel */
1078 static void
1079 ssh_session2_setup(int id, void *arg)
1080 {
1081         extern char **environ;
1082
1083         int interactive = tty_flag;
1084         if (options.forward_x11 && getenv("DISPLAY") != NULL) {
1085                 char *proto, *data;
1086                 /* Get reasonable local authentication information. */
1087                 x11_get_proto(&proto, &data);
1088                 /* Request forwarding with authentication spoofing. */
1089                 debug("Requesting X11 forwarding with authentication spoofing.");
1090                 x11_request_forwarding_with_spoofing(id, proto, data);
1091                 interactive = 1;
1092                 /* XXX wait for reply */
1093         }
1094
1095         check_agent_present();
1096         if (options.forward_agent) {
1097                 debug("Requesting authentication agent forwarding.");
1098                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1099                 packet_send();
1100         }
1101
1102         client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1103             NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply);
1104
1105         packet_set_interactive(interactive);
1106 }
1107
1108 /* open new channel for a session */
1109 static int
1110 ssh_session2_open(void)
1111 {
1112         Channel *c;
1113         int window, packetmax, in, out, err;
1114
1115         if (stdin_null_flag) {
1116                 in = open(_PATH_DEVNULL, O_RDONLY);
1117         } else {
1118                 in = dup(STDIN_FILENO);
1119         }
1120         out = dup(STDOUT_FILENO);
1121         err = dup(STDERR_FILENO);
1122
1123         if (in < 0 || out < 0 || err < 0)
1124                 fatal("dup() in/out/err failed");
1125
1126         /* enable nonblocking unless tty */
1127         if (!isatty(in))
1128                 set_nonblock(in);
1129         if (!isatty(out))
1130                 set_nonblock(out);
1131         if (!isatty(err))
1132                 set_nonblock(err);
1133
1134         window = CHAN_SES_WINDOW_DEFAULT;
1135         packetmax = CHAN_SES_PACKET_DEFAULT;
1136         if (tty_flag) {
1137                 window >>= 1;
1138                 packetmax >>= 1;
1139         }
1140         c = channel_new(
1141             "session", SSH_CHANNEL_OPENING, in, out, err,
1142             window, packetmax, CHAN_EXTENDED_WRITE,
1143             "client-session", /*nonblock*/0);
1144
1145         debug3("ssh_session2_open: channel_new: %d", c->self);
1146
1147         channel_send_open(c->self);
1148         if (!no_shell_flag)
1149                 channel_register_confirm(c->self, ssh_session2_setup, NULL);
1150
1151         return c->self;
1152 }
1153
1154 static int
1155 ssh_session2(void)
1156 {
1157         int id = -1;
1158
1159         /* XXX should be pre-session */
1160         ssh_init_forwarding();
1161         ssh_control_listener();
1162
1163         if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1164                 id = ssh_session2_open();
1165
1166         /* If requested, let ssh continue in the background. */
1167         if (fork_after_authentication_flag)
1168                 if (daemon(1, 1) < 0)
1169                         fatal("daemon() failed: %.200s", strerror(errno));
1170
1171         return client_loop(tty_flag, tty_flag ?
1172             options.escape_char : SSH_ESCAPECHAR_NONE, id);
1173 }
1174
1175 static void
1176 load_public_identity_files(void)
1177 {
1178         char *filename;
1179         int i = 0;
1180         Key *public;
1181 #ifdef SMARTCARD
1182         Key **keys;
1183
1184         if (options.smartcard_device != NULL &&
1185             options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1186             (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL ) {
1187                 int count = 0;
1188                 for (i = 0; keys[i] != NULL; i++) {
1189                         count++;
1190                         memmove(&options.identity_files[1], &options.identity_files[0],
1191                             sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1));
1192                         memmove(&options.identity_keys[1], &options.identity_keys[0],
1193                             sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1));
1194                         options.num_identity_files++;
1195                         options.identity_keys[0] = keys[i];
1196                         options.identity_files[0] = sc_get_key_label(keys[i]);
1197                 }
1198                 if (options.num_identity_files > SSH_MAX_IDENTITY_FILES)
1199                         options.num_identity_files = SSH_MAX_IDENTITY_FILES;
1200                 i = count;
1201                 xfree(keys);
1202         }
1203 #endif /* SMARTCARD */
1204         for (; i < options.num_identity_files; i++) {
1205                 filename = tilde_expand_filename(options.identity_files[i],
1206                     original_real_uid);
1207                 public = key_load_public(filename, NULL);
1208                 debug("identity file %s type %d", filename,
1209                     public ? public->type : -1);
1210                 xfree(options.identity_files[i]);
1211                 options.identity_files[i] = filename;
1212                 options.identity_keys[i] = public;
1213         }
1214 }
1215
1216 static void
1217 control_client_sighandler(int signo)
1218 {
1219         control_client_terminate = signo;
1220 }
1221
1222 static void
1223 control_client_sigrelay(int signo)
1224 {
1225         if (control_server_pid > 1)
1226                 kill(control_server_pid, signo);
1227 }
1228
1229 static int
1230 env_permitted(char *env)
1231 {
1232         int i;
1233         char name[1024], *cp;
1234
1235         strlcpy(name, env, sizeof(name));
1236         if ((cp = strchr(name, '=')) == NULL)
1237                 return (0);
1238
1239         *cp = '\0';
1240
1241         for (i = 0; i < options.num_send_env; i++)
1242                 if (match_pattern(name, options.send_env[i]))
1243                         return (1);
1244
1245         return (0);
1246 }
1247
1248 static void
1249 control_client(const char *path)
1250 {
1251         struct sockaddr_un addr;
1252         int i, r, sock, exitval, num_env, addr_len;
1253         Buffer m;
1254         char *cp;
1255         extern char **environ;
1256
1257         memset(&addr, '\0', sizeof(addr));
1258         addr.sun_family = AF_UNIX;
1259         addr_len = offsetof(struct sockaddr_un, sun_path) +
1260             strlen(path) + 1;
1261
1262         if (strlcpy(addr.sun_path, path,
1263             sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
1264                 fatal("ControlPath too long");
1265
1266         if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1267                 fatal("%s socket(): %s", __func__, strerror(errno));
1268
1269         if (connect(sock, (struct sockaddr*)&addr, addr_len) == -1)
1270                 fatal("Couldn't connect to %s: %s", path, strerror(errno));
1271
1272         if ((cp = getenv("TERM")) == NULL)
1273                 cp = "";
1274
1275         buffer_init(&m);
1276
1277         /* Get PID of controlee */
1278         if (ssh_msg_recv(sock, &m) == -1)
1279                 fatal("%s: msg_recv", __func__);
1280         if (buffer_get_char(&m) != 0)
1281                 fatal("%s: wrong version", __func__);
1282         /* Connection allowed? */
1283         if (buffer_get_int(&m) != 1)
1284                 fatal("Connection to master denied");
1285         control_server_pid = buffer_get_int(&m);
1286
1287         buffer_clear(&m);
1288         buffer_put_int(&m, tty_flag);
1289         buffer_put_int(&m, subsystem_flag);
1290         buffer_put_cstring(&m, cp);
1291
1292         buffer_append(&command, "\0", 1);
1293         buffer_put_cstring(&m, buffer_ptr(&command));
1294
1295         if (options.num_send_env == 0 || environ == NULL) {
1296                 buffer_put_int(&m, 0);
1297         } else {
1298                 /* Pass environment */
1299                 num_env = 0;
1300                 for (i = 0; environ[i] != NULL; i++)
1301                         if (env_permitted(environ[i]))
1302                                 num_env++; /* Count */
1303
1304                 buffer_put_int(&m, num_env);
1305
1306                 for (i = 0; environ[i] != NULL && num_env >= 0; i++)
1307                         if (env_permitted(environ[i])) {
1308                                 num_env--;
1309                                 buffer_put_cstring(&m, environ[i]);
1310                         }
1311         }
1312
1313         if (ssh_msg_send(sock, /* version */0, &m) == -1)
1314                 fatal("%s: msg_send", __func__);
1315
1316         mm_send_fd(sock, STDIN_FILENO);
1317         mm_send_fd(sock, STDOUT_FILENO);
1318         mm_send_fd(sock, STDERR_FILENO);
1319
1320         /* Wait for reply, so master has a chance to gather ttymodes */
1321         buffer_clear(&m);
1322         if (ssh_msg_recv(sock, &m) == -1)
1323                 fatal("%s: msg_recv", __func__);
1324         if (buffer_get_char(&m) != 0)
1325                 fatal("%s: master returned error", __func__);
1326         buffer_free(&m);
1327
1328         signal(SIGINT, control_client_sighandler);
1329         signal(SIGTERM, control_client_sighandler);
1330         signal(SIGWINCH, control_client_sigrelay);
1331
1332         if (tty_flag)
1333                 enter_raw_mode();
1334
1335         /* Stick around until the controlee closes the client_fd */
1336         exitval = 0;
1337         for (;!control_client_terminate;) {
1338                 r = read(sock, &exitval, sizeof(exitval));
1339                 if (r == 0) {
1340                         debug2("Received EOF from master");
1341                         break;
1342                 }
1343                 if (r > 0)
1344                         debug2("Received exit status from master %d", exitval);
1345                 if (r == -1 && errno != EINTR)
1346                         fatal("%s: read %s", __func__, strerror(errno));
1347         }
1348
1349         if (control_client_terminate)
1350                 debug2("Exiting on signal %d", control_client_terminate);
1351
1352         close(sock);
1353
1354         leave_raw_mode();
1355
1356         if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
1357                 fprintf(stderr, "Connection to master closed.\r\n");
1358
1359         exit(exitval);
1360 }