crypto/openssh/ssh.c

   1 /* $OpenBSD: ssh.c,v 1.318 2008/07/02 13:47:39 djm Exp $ */
   2 /*
   3  * Author: Tatu Ylonen <ylo@cs.hut.fi>
   4  * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
   5  *                    All rights reserved
   6  * Ssh client program.  This program can be used to log into a remote machine.
   7  * The software supports strong authentication, encryption, and forwarding
   8  * of X11, TCP/IP, and authentication connections.
   9  *
  10  * As far as I am concerned, the code I have written for this software
  11  * can be used freely for any purpose.  Any derived versions of this
  12  * software must be clearly marked as such, and if the derived work is
  13  * incompatible with the protocol description in the RFC file, it must be
  14  * called by a name other than "ssh" or "Secure Shell".
  15  *
  16  * Copyright (c) 1999 Niels Provos.  All rights reserved.
  17  * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl.  All rights reserved.
  18  *
  19  * Modified to work with SSL by Niels Provos <provos@citi.umich.edu>
  20  * in Canada (German citizen).
  21  *
  22  * Redistribution and use in source and binary forms, with or without
  23  * modification, are permitted provided that the following conditions
  24  * are met:
  25  * 1. Redistributions of source code must retain the above copyright
  26  *    notice, this list of conditions and the following disclaimer.
  27  * 2. Redistributions in binary form must reproduce the above copyright
  28  *    notice, this list of conditions and the following disclaimer in the
  29  *    documentation and/or other materials provided with the distribution.
  30  *
  31  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
  32  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
  33  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
  34  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
  35  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
  36  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
  37  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
  38  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
  39  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
  40  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  41  */
  42
  43 #include "includes.h"
  44 __RCSID("$FreeBSD$");
  45
  46 #include <sys/types.h>
  47 #ifdef HAVE_SYS_STAT_H
  48 # include <sys/stat.h>
  49 #endif
  50 #include <sys/resource.h>
  51 #include <sys/ioctl.h>
  52 #include <sys/socket.h>
  53
  54 #include <ctype.h>
  55 #include <errno.h>
  56 #include <fcntl.h>
  57 #include <netdb.h>
  58 #ifdef HAVE_PATHS_H
  59 #include <paths.h>
  60 #endif
  61 #include <pwd.h>
  62 #include <signal.h>
  63 #include <stdarg.h>
  64 #include <stddef.h>
  65 #include <stdio.h>
  66 #include <stdlib.h>
  67 #include <string.h>
  68 #include <unistd.h>
  69
  70 #include <netinet/in.h>
  71 #include <arpa/inet.h>
  72
  73 #include <openssl/evp.h>
  74 #include <openssl/err.h>
  75 #include "openbsd-compat/openssl-compat.h"
  76 #include "openbsd-compat/sys-queue.h"
  77
  78 #include "xmalloc.h"
  79 #include "ssh.h"
  80 #include "ssh1.h"
  81 #include "ssh2.h"
  82 #include "compat.h"
  83 #include "cipher.h"
  84 #include "packet.h"
  85 #include "buffer.h"
  86 #include "channels.h"
  87 #include "key.h"
  88 #include "authfd.h"
  89 #include "authfile.h"
  90 #include "pathnames.h"
  91 #include "dispatch.h"
  92 #include "clientloop.h"
  93 #include "log.h"
  94 #include "readconf.h"
  95 #include "sshconnect.h"
  96 #include "misc.h"
  97 #include "kex.h"
  98 #include "mac.h"
  99 #include "sshpty.h"
 100 #include "match.h"
 101 #include "msg.h"
 102 #include "uidswap.h"
 103 #include "version.h"
 104
 105 #ifdef SMARTCARD
 106 #include "scard.h"
 107 #endif
 108
 109 extern char *__progname;
 110
 111 /* Flag indicating whether debug mode is on.  May be set on the command line. */
 112 int debug_flag = 0;
 113
 114 /* Flag indicating whether a tty should be allocated */
 115 int tty_flag = 0;
 116 int no_tty_flag = 0;
 117 int force_tty_flag = 0;
 118
 119 /* don't exec a shell */
 120 int no_shell_flag = 0;
 121
 122 /*
 123  * Flag indicating that nothing should be read from stdin.  This can be set
 124  * on the command line.
 125  */
 126 int stdin_null_flag = 0;
 127
 128 /*
 129  * Flag indicating that ssh should fork after authentication.  This is useful
 130  * so that the passphrase can be entered manually, and then ssh goes to the
 131  * background.
 132  */
 133 int fork_after_authentication_flag = 0;
 134
 135 /*
 136  * General data structure for command line options and options configurable
 137  * in configuration files.  See readconf.h.
 138  */
 139 Options options;
 140
 141 /* optional user configfile */
 142 char *config = NULL;
 143
 144 /*
 145  * Name of the host we are connecting to.  This is the name given on the
 146  * command line, or the HostName specified for the user-supplied name in a
 147  * configuration file.
 148  */
 149 char *host;
 150
 151 /* socket address the host resolves to */
 152 struct sockaddr_storage hostaddr;
 153
 154 /* Private host keys. */
 155 Sensitive sensitive_data;
 156
 157 /* Original real UID. */
 158 uid_t original_real_uid;
 159 uid_t original_effective_uid;
 160
 161 /* command to be executed */
 162 Buffer command;
 163
 164 /* Should we execute a command or invoke a subsystem? */
 165 int subsystem_flag = 0;
 166
 167 /* # of replies received for global requests */
 168 static int remote_forward_confirms_received = 0;
 169
 170 /* pid of proxycommand child process */
 171 pid_t proxy_command_pid = 0;
 172
 173 /* mux.c */
 174 extern int muxserver_sock;
 175 extern u_int muxclient_command;
 176
 177 /* Prints a help message to the user.  This function never returns. */
 178
 179 static void
 180 usage(void)
 181 {
 182         fprintf(stderr,
 183 "usage: ssh [-1246AaCfgKkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n"
 184 "           [-D [bind_address:]port] [-e escape_char] [-F configfile]\n"
 185 "           [-i identity_file] [-L [bind_address:]port:host:hostport]\n"
 186 "           [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
 187 "           [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
 188 "           [-w local_tun[:remote_tun]] [user@]hostname [command]\n"
 189         );
 190         exit(255);
 191 }
 192
 193 static int ssh_session(void);
 194 static int ssh_session2(void);
 195 static void load_public_identity_files(void);
 196
 197 /* from muxclient.c */
 198 void muxclient(const char *);
 199 void muxserver_listen(void);
 200
 201 /*
 202  * Main program for the ssh client.
 203  */
 204 int
 205 main(int ac, char **av)
 206 {
 207         int i, opt, exit_status;
 208         char *p, *cp, *line, buf[256];
 209         struct stat st;
 210         struct passwd *pw;
 211         int dummy, timeout_ms;
 212         extern int optind, optreset;
 213         extern char *optarg;
 214         struct servent *sp;
 215         Forward fwd;
 216
 217         /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
 218         sanitise_stdfd();
 219
 220         __progname = ssh_get_progname(av[0]);
 221         init_rng();
 222
 223         /*
 224          * Save the original real uid.  It will be needed later (uid-swapping
 225          * may clobber the real uid).
 226          */
 227         original_real_uid = getuid();
 228         original_effective_uid = geteuid();
 229
 230         /*
 231          * Use uid-swapping to give up root privileges for the duration of
 232          * option processing.  We will re-instantiate the rights when we are
 233          * ready to create the privileged port, and will permanently drop
 234          * them when the port has been created (actually, when the connection
 235          * has been made, as we may need to create the port several times).
 236          */
 237         PRIV_END;
 238
 239 #ifdef HAVE_SETRLIMIT
 240         /* If we are installed setuid root be careful to not drop core. */
 241         if (original_real_uid != original_effective_uid) {
 242                 struct rlimit rlim;
 243                 rlim.rlim_cur = rlim.rlim_max = 0;
 244                 if (setrlimit(RLIMIT_CORE, &rlim) < 0)
 245                         fatal("setrlimit failed: %.100s", strerror(errno));
 246         }
 247 #endif
 248         /* Get user data. */
 249         pw = getpwuid(original_real_uid);
 250         if (!pw) {
 251                 logit("You don't exist, go away!");
 252                 exit(255);
 253         }
 254         /* Take a copy of the returned structure. */
 255         pw = pwcopy(pw);
 256
 257         /*
 258          * Set our umask to something reasonable, as some files are created
 259          * with the default umask.  This will make them world-readable but
 260          * writable only by the owner, which is ok for all files for which we
 261          * don't set the modes explicitly.
 262          */
 263         umask(022);
 264
 265         /*
 266          * Initialize option structure to indicate that no values have been
 267          * set.
 268          */
 269         initialize_options(&options);
 270
 271         /* Parse command-line arguments. */
 272         host = NULL;
 273
 274  again:
 275         while ((opt = getopt(ac, av, "1246ab:c:e:fgi:kl:m:no:p:qstvx"
 276             "ACD:F:I:KL:MNO:PR:S:TVw:XY")) != -1) {
 277                 switch (opt) {
 278                 case '1':
 279                         options.protocol = SSH_PROTO_1;
 280                         break;
 281                 case '2':
 282                         options.protocol = SSH_PROTO_2;
 283                         break;
 284                 case '4':
 285                         options.address_family = AF_INET;
 286                         break;
 287                 case '6':
 288                         options.address_family = AF_INET6;
 289                         break;
 290                 case 'n':
 291                         stdin_null_flag = 1;
 292                         break;
 293                 case 'f':
 294                         fork_after_authentication_flag = 1;
 295                         stdin_null_flag = 1;
 296                         break;
 297                 case 'x':
 298                         options.forward_x11 = 0;
 299                         break;
 300                 case 'X':
 301                         options.forward_x11 = 1;
 302                         break;
 303                 case 'Y':
 304                         options.forward_x11 = 1;
 305                         options.forward_x11_trusted = 1;
 306                         break;
 307                 case 'g':
 308                         options.gateway_ports = 1;
 309                         break;
 310                 case 'O':
 311                         if (strcmp(optarg, "check") == 0)
 312                                 muxclient_command = SSHMUX_COMMAND_ALIVE_CHECK;
 313                         else if (strcmp(optarg, "exit") == 0)
 314                                 muxclient_command = SSHMUX_COMMAND_TERMINATE;
 315                         else
 316                                 fatal("Invalid multiplex command.");
 317                         break;
 318                 case 'P':       /* deprecated */
 319                         options.use_privileged_port = 0;
 320                         break;
 321                 case 'a':
 322                         options.forward_agent = 0;
 323                         break;
 324                 case 'A':
 325                         options.forward_agent = 1;
 326                         break;
 327                 case 'k':
 328                         options.gss_deleg_creds = 0;
 329                         break;
 330                 case 'K':
 331                         options.gss_authentication = 1;
 332                         options.gss_deleg_creds = 1;
 333                         break;
 334                 case 'i':
 335                         if (stat(optarg, &st) < 0) {
 336                                 fprintf(stderr, "Warning: Identity file %s "
 337                                     "not accessible: %s.\n", optarg,
 338                                     strerror(errno));
 339                                 break;
 340                         }
 341                         if (options.num_identity_files >=
 342                             SSH_MAX_IDENTITY_FILES)
 343                                 fatal("Too many identity files specified "
 344                                     "(max %d)", SSH_MAX_IDENTITY_FILES);
 345                         options.identity_files[options.num_identity_files++] =
 346                             xstrdup(optarg);
 347                         break;
 348                 case 'I':
 349 #ifdef SMARTCARD
 350                         options.smartcard_device = xstrdup(optarg);
 351 #else
 352                         fprintf(stderr, "no support for smartcards.\n");
 353 #endif
 354                         break;
 355                 case 't':
 356                         if (tty_flag)
 357                                 force_tty_flag = 1;
 358                         tty_flag = 1;
 359                         break;
 360                 case 'v':
 361                         if (debug_flag == 0) {
 362                                 debug_flag = 1;
 363                                 options.log_level = SYSLOG_LEVEL_DEBUG1;
 364                         } else {
 365                                 if (options.log_level < SYSLOG_LEVEL_DEBUG3)
 366                                         options.log_level++;
 367                                 break;
 368                         }
 369                         /* FALLTHROUGH */
 370                 case 'V':
 371                         fprintf(stderr, "%s, %s\n",
 372                             SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
 373                         if (opt == 'V')
 374                                 exit(0);
 375                         break;
 376                 case 'w':
 377                         if (options.tun_open == -1)
 378                                 options.tun_open = SSH_TUNMODE_DEFAULT;
 379                         options.tun_local = a2tun(optarg, &options.tun_remote);
 380                         if (options.tun_local == SSH_TUNID_ERR) {
 381                                 fprintf(stderr,
 382                                     "Bad tun device '%s'\n", optarg);
 383                                 exit(255);
 384                         }
 385                         break;
 386                 case 'q':
 387                         options.log_level = SYSLOG_LEVEL_QUIET;
 388                         break;
 389                 case 'e':
 390                         if (optarg[0] == '^' && optarg[2] == 0 &&
 391                             (u_char) optarg[1] >= 64 &&
 392                             (u_char) optarg[1] < 128)
 393                                 options.escape_char = (u_char) optarg[1] & 31;
 394                         else if (strlen(optarg) == 1)
 395                                 options.escape_char = (u_char) optarg[0];
 396                         else if (strcmp(optarg, "none") == 0)
 397                                 options.escape_char = SSH_ESCAPECHAR_NONE;
 398                         else {
 399                                 fprintf(stderr, "Bad escape character '%s'.\n",
 400                                     optarg);
 401                                 exit(255);
 402                         }
 403                         break;
 404                 case 'c':
 405                         if (ciphers_valid(optarg)) {
 406                                 /* SSH2 only */
 407                                 options.ciphers = xstrdup(optarg);
 408                                 options.cipher = SSH_CIPHER_INVALID;
 409                         } else {
 410                                 /* SSH1 only */
 411                                 options.cipher = cipher_number(optarg);
 412                                 if (options.cipher == -1) {
 413                                         fprintf(stderr,
 414                                             "Unknown cipher type '%s'\n",
 415                                             optarg);
 416                                         exit(255);
 417                                 }
 418                                 if (options.cipher == SSH_CIPHER_3DES)
 419                                         options.ciphers = "3des-cbc";
 420                                 else if (options.cipher == SSH_CIPHER_BLOWFISH)
 421                                         options.ciphers = "blowfish-cbc";
 422                                 else
 423                                         options.ciphers = (char *)-1;
 424                         }
 425                         break;
 426                 case 'm':
 427                         if (mac_valid(optarg))
 428                                 options.macs = xstrdup(optarg);
 429                         else {
 430                                 fprintf(stderr, "Unknown mac type '%s'\n",
 431                                     optarg);
 432                                 exit(255);
 433                         }
 434                         break;
 435                 case 'M':
 436                         if (options.control_master == SSHCTL_MASTER_YES)
 437                                 options.control_master = SSHCTL_MASTER_ASK;
 438                         else
 439                                 options.control_master = SSHCTL_MASTER_YES;
 440                         break;
 441                 case 'p':
 442                         options.port = a2port(optarg);
 443                         if (options.port == 0) {
 444                                 fprintf(stderr, "Bad port '%s'\n", optarg);
 445                                 exit(255);
 446                         }
 447                         break;
 448                 case 'l':
 449                         options.user = optarg;
 450                         break;
 451
 452                 case 'L':
 453                         if (parse_forward(&fwd, optarg))
 454                                 add_local_forward(&options, &fwd);
 455                         else {
 456                                 fprintf(stderr,
 457                                     "Bad local forwarding specification '%s'\n",
 458                                     optarg);
 459                                 exit(255);
 460                         }
 461                         break;
 462
 463                 case 'R':
 464                         if (parse_forward(&fwd, optarg)) {
 465                                 add_remote_forward(&options, &fwd);
 466                         } else {
 467                                 fprintf(stderr,
 468                                     "Bad remote forwarding specification "
 469                                     "'%s'\n", optarg);
 470                                 exit(255);
 471                         }
 472                         break;
 473
 474                 case 'D':
 475                         cp = p = xstrdup(optarg);
 476                         memset(&fwd, '\0', sizeof(fwd));
 477                         fwd.connect_host = "socks";
 478                         if ((fwd.listen_host = hpdelim(&cp)) == NULL) {
 479                                 fprintf(stderr, "Bad dynamic forwarding "
 480                                     "specification '%.100s'\n", optarg);
 481                                 exit(255);
 482                         }
 483                         if (cp != NULL) {
 484                                 fwd.listen_port = a2port(cp);
 485                                 fwd.listen_host =
 486                                     cleanhostname(fwd.listen_host);
 487                         } else {
 488                                 fwd.listen_port = a2port(fwd.listen_host);
 489                                 fwd.listen_host = NULL;
 490                         }
 491
 492                         if (fwd.listen_port == 0) {
 493                                 fprintf(stderr, "Bad dynamic port '%s'\n",
 494                                     optarg);
 495                                 exit(255);
 496                         }
 497                         add_local_forward(&options, &fwd);
 498                         xfree(p);
 499                         break;
 500
 501                 case 'C':
 502                         options.compression = 1;
 503                         break;
 504                 case 'N':
 505                         no_shell_flag = 1;
 506                         no_tty_flag = 1;
 507                         break;
 508                 case 'T':
 509                         no_tty_flag = 1;
 510                         break;
 511                 case 'o':
 512                         dummy = 1;
 513                         line = xstrdup(optarg);
 514                         if (process_config_line(&options, host ? host : "",
 515                             line, "command-line", 0, &dummy) != 0)
 516                                 exit(255);
 517                         xfree(line);
 518                         break;
 519                 case 's':
 520                         subsystem_flag = 1;
 521                         break;
 522                 case 'S':
 523                         if (options.control_path != NULL)
 524                                 free(options.control_path);
 525                         options.control_path = xstrdup(optarg);
 526                         break;
 527                 case 'b':
 528                         options.bind_address = optarg;
 529                         break;
 530                 case 'F':
 531                         config = optarg;
 532                         break;
 533                 default:
 534                         usage();
 535                 }
 536         }
 537
 538         ac -= optind;
 539         av += optind;
 540
 541         if (ac > 0 && !host && **av != '-') {
 542                 if (strrchr(*av, '@')) {
 543                         p = xstrdup(*av);
 544                         cp = strrchr(p, '@');
 545                         if (cp == NULL || cp == p)
 546                                 usage();
 547                         options.user = p;
 548                         *cp = '\0';
 549                         host = ++cp;
 550                 } else
 551                         host = *av;
 552                 if (ac > 1) {
 553                         optind = optreset = 1;
 554                         goto again;
 555                 }
 556                 ac--, av++;
 557         }
 558
 559         /* Check that we got a host name. */
 560         if (!host)
 561                 usage();
 562
 563         SSLeay_add_all_algorithms();
 564         ERR_load_crypto_strings();
 565
 566         /* Initialize the command to execute on remote host. */
 567         buffer_init(&command);
 568
 569         /*
 570          * Save the command to execute on the remote host in a buffer. There
 571          * is no limit on the length of the command, except by the maximum
 572          * packet size.  Also sets the tty flag if there is no command.
 573          */
 574         if (!ac) {
 575                 /* No command specified - execute shell on a tty. */
 576                 tty_flag = 1;
 577                 if (subsystem_flag) {
 578                         fprintf(stderr,
 579                             "You must specify a subsystem to invoke.\n");
 580                         usage();
 581                 }
 582         } else {
 583                 /* A command has been specified.  Store it into the buffer. */
 584                 for (i = 0; i < ac; i++) {
 585                         if (i)
 586                                 buffer_append(&command, " ", 1);
 587                         buffer_append(&command, av[i], strlen(av[i]));
 588                 }
 589         }
 590
 591         /* Cannot fork to background if no command. */
 592         if (fork_after_authentication_flag && buffer_len(&command) == 0 &&
 593             !no_shell_flag)
 594                 fatal("Cannot fork into background without a command "
 595                     "to execute.");
 596
 597         /* Allocate a tty by default if no command specified. */
 598         if (buffer_len(&command) == 0)
 599                 tty_flag = 1;
 600
 601         /* Force no tty */
 602         if (no_tty_flag)
 603                 tty_flag = 0;
 604         /* Do not allocate a tty if stdin is not a tty. */
 605         if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
 606                 if (tty_flag)
 607                         logit("Pseudo-terminal will not be allocated because "
 608                             "stdin is not a terminal.");
 609                 tty_flag = 0;
 610         }
 611
 612         /*
 613          * Initialize "log" output.  Since we are the client all output
 614          * actually goes to stderr.
 615          */
 616         log_init(av[0],
 617             options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
 618             SYSLOG_FACILITY_USER, 1);
 619
 620         /*
 621          * Read per-user configuration file.  Ignore the system wide config
 622          * file if the user specifies a config file on the command line.
 623          */
 624         if (config != NULL) {
 625                 if (!read_config_file(config, host, &options, 0))
 626                         fatal("Can't open user config file %.100s: "
 627                             "%.100s", config, strerror(errno));
 628         } else {
 629                 snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
 630                     _PATH_SSH_USER_CONFFILE);
 631                 (void)read_config_file(buf, host, &options, 1);
 632
 633                 /* Read systemwide configuration file after use config. */
 634                 (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
 635                     &options, 0);
 636         }
 637
 638         /* Fill configuration defaults. */
 639         fill_default_options(&options);
 640
 641         channel_set_af(options.address_family);
 642
 643         /* reinit */
 644         log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1);
 645
 646         seed_rng();
 647
 648         if (options.user == NULL)
 649                 options.user = xstrdup(pw->pw_name);
 650
 651         /* Get default port if port has not been set. */
 652         if (options.port == 0) {
 653                 sp = getservbyname(SSH_SERVICE_NAME, "tcp");
 654                 options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
 655         }
 656
 657         if (options.local_command != NULL) {
 658                 char thishost[NI_MAXHOST];
 659
 660                 if (gethostname(thishost, sizeof(thishost)) == -1)
 661                         fatal("gethostname: %s", strerror(errno));
 662                 snprintf(buf, sizeof(buf), "%d", options.port);
 663                 debug3("expanding LocalCommand: %s", options.local_command);
 664                 cp = options.local_command;
 665                 options.local_command = percent_expand(cp, "d", pw->pw_dir,
 666                     "h", options.hostname? options.hostname : host,
 667                     "l", thishost, "n", host, "r", options.user, "p", buf,
 668                     "u", pw->pw_name, (char *)NULL);
 669                 debug3("expanded LocalCommand: %s", options.local_command);
 670                 xfree(cp);
 671         }
 672
 673         if (options.hostname != NULL)
 674                 host = options.hostname;
 675
 676         /* Find canonic host name. */
 677         if (strchr(host, '.') == 0) {
 678                 struct addrinfo hints;
 679                 struct addrinfo *ai = NULL;
 680                 int errgai;
 681                 memset(&hints, 0, sizeof(hints));
 682                 hints.ai_family = options.address_family;
 683                 hints.ai_flags = AI_CANONNAME;
 684                 hints.ai_socktype = SOCK_STREAM;
 685                 errgai = getaddrinfo(host, NULL, &hints, &ai);
 686                 if (errgai == 0) {
 687                         if (ai->ai_canonname != NULL)
 688                                 host = xstrdup(ai->ai_canonname);
 689                         freeaddrinfo(ai);
 690                 }
 691         }
 692
 693         /* force lowercase for hostkey matching */
 694         if (options.host_key_alias != NULL) {
 695                 for (p = options.host_key_alias; *p; p++)
 696                         if (isupper(*p))
 697                                 *p = (char)tolower(*p);
 698         }
 699
 700         if (options.proxy_command != NULL &&
 701             strcmp(options.proxy_command, "none") == 0) {
 702                 xfree(options.proxy_command);
 703                 options.proxy_command = NULL;
 704         }
 705         if (options.control_path != NULL &&
 706             strcmp(options.control_path, "none") == 0) {
 707                 xfree(options.control_path);
 708                 options.control_path = NULL;
 709         }
 710
 711         if (options.control_path != NULL) {
 712                 char thishost[NI_MAXHOST];
 713
 714                 if (gethostname(thishost, sizeof(thishost)) == -1)
 715                         fatal("gethostname: %s", strerror(errno));
 716                 snprintf(buf, sizeof(buf), "%d", options.port);
 717                 cp = tilde_expand_filename(options.control_path,
 718                     original_real_uid);
 719                 xfree(options.control_path);
 720                 options.control_path = percent_expand(cp, "p", buf, "h", host,
 721                     "r", options.user, "l", thishost, (char *)NULL);
 722                 xfree(cp);
 723         }
 724         if (muxclient_command != 0 && options.control_path == NULL)
 725                 fatal("No ControlPath specified for \"-O\" command");
 726         if (options.control_path != NULL)
 727                 muxclient(options.control_path);
 728
 729         timeout_ms = options.connection_timeout * 1000;
 730
 731         /* Open a connection to the remote host. */
 732         if (ssh_connect(host, &hostaddr, options.port,
 733             options.address_family, options.connection_attempts, &timeout_ms,
 734             options.tcp_keep_alive,
 735 #ifdef HAVE_CYGWIN
 736             options.use_privileged_port,
 737 #else
 738             original_effective_uid == 0 && options.use_privileged_port,
 739 #endif
 740             options.proxy_command) != 0)
 741                 exit(255);
 742
 743         if (timeout_ms > 0)
 744                 debug3("timeout: %d ms remain after connect", timeout_ms);
 745
 746         /*
 747          * If we successfully made the connection, load the host private key
 748          * in case we will need it later for combined rsa-rhosts
 749          * authentication. This must be done before releasing extra
 750          * privileges, because the file is only readable by root.
 751          * If we cannot access the private keys, load the public keys
 752          * instead and try to execute the ssh-keysign helper instead.
 753          */
 754         sensitive_data.nkeys = 0;
 755         sensitive_data.keys = NULL;
 756         sensitive_data.external_keysign = 0;
 757         if (options.rhosts_rsa_authentication ||
 758             options.hostbased_authentication) {
 759                 sensitive_data.nkeys = 3;
 760                 sensitive_data.keys = xcalloc(sensitive_data.nkeys,
 761                     sizeof(Key));
 762
 763                 PRIV_START;
 764                 sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
 765                     _PATH_HOST_KEY_FILE, "", NULL, NULL);
 766                 sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
 767                     _PATH_HOST_DSA_KEY_FILE, "", NULL, NULL);
 768                 sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
 769                     _PATH_HOST_RSA_KEY_FILE, "", NULL, NULL);
 770                 PRIV_END;
 771
 772                 if (options.hostbased_authentication == 1 &&
 773                     sensitive_data.keys[0] == NULL &&
 774                     sensitive_data.keys[1] == NULL &&
 775                     sensitive_data.keys[2] == NULL) {
 776                         sensitive_data.keys[1] = key_load_public(
 777                             _PATH_HOST_DSA_KEY_FILE, NULL);
 778                         sensitive_data.keys[2] = key_load_public(
 779                             _PATH_HOST_RSA_KEY_FILE, NULL);
 780                         sensitive_data.external_keysign = 1;
 781                 }
 782         }
 783         /*
 784          * Get rid of any extra privileges that we may have.  We will no
 785          * longer need them.  Also, extra privileges could make it very hard
 786          * to read identity files and other non-world-readable files from the
 787          * user's home directory if it happens to be on a NFS volume where
 788          * root is mapped to nobody.
 789          */
 790         if (original_effective_uid == 0) {
 791                 PRIV_START;
 792                 permanently_set_uid(pw);
 793         }
 794
 795         /*
 796          * Now that we are back to our own permissions, create ~/.ssh
 797          * directory if it doesn't already exist.
 798          */
 799         snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir,
 800             strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
 801         if (stat(buf, &st) < 0)
 802                 if (mkdir(buf, 0700) < 0)
 803                         error("Could not create directory '%.200s'.", buf);
 804
 805         /* load options.identity_files */
 806         load_public_identity_files();
 807
 808         /* Expand ~ in known host file names. */
 809         /* XXX mem-leaks: */
 810         options.system_hostfile =
 811             tilde_expand_filename(options.system_hostfile, original_real_uid);
 812         options.user_hostfile =
 813             tilde_expand_filename(options.user_hostfile, original_real_uid);
 814         options.system_hostfile2 =
 815             tilde_expand_filename(options.system_hostfile2, original_real_uid);
 816         options.user_hostfile2 =
 817             tilde_expand_filename(options.user_hostfile2, original_real_uid);
 818
 819         signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
 820
 821         /* Log into the remote system.  Never returns if the login fails. */
 822         ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr,
 823             pw, timeout_ms);
 824
 825         /* We no longer need the private host keys.  Clear them now. */
 826         if (sensitive_data.nkeys != 0) {
 827                 for (i = 0; i < sensitive_data.nkeys; i++) {
 828                         if (sensitive_data.keys[i] != NULL) {
 829                                 /* Destroys contents safely */
 830                                 debug3("clear hostkey %d", i);
 831                                 key_free(sensitive_data.keys[i]);
 832                                 sensitive_data.keys[i] = NULL;
 833                         }
 834                 }
 835                 xfree(sensitive_data.keys);
 836         }
 837         for (i = 0; i < options.num_identity_files; i++) {
 838                 if (options.identity_files[i]) {
 839                         xfree(options.identity_files[i]);
 840                         options.identity_files[i] = NULL;
 841                 }
 842                 if (options.identity_keys[i]) {
 843                         key_free(options.identity_keys[i]);
 844                         options.identity_keys[i] = NULL;
 845                 }
 846         }
 847
 848         exit_status = compat20 ? ssh_session2() : ssh_session();
 849         packet_close();
 850
 851         if (options.control_path != NULL && muxserver_sock != -1)
 852                 unlink(options.control_path);
 853
 854         /*
 855          * Send SIGHUP to proxy command if used. We don't wait() in
 856          * case it hangs and instead rely on init to reap the child
 857          */
 858         if (proxy_command_pid > 1)
 859                 kill(proxy_command_pid, SIGHUP);
 860
 861         return exit_status;
 862 }
 863
 864 /* Callback for remote forward global requests */
 865 static void
 866 ssh_confirm_remote_forward(int type, u_int32_t seq, void *ctxt)
 867 {
 868         Forward *rfwd = (Forward *)ctxt;
 869
 870         debug("remote forward %s for: listen %d, connect %s:%d",
 871             type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
 872             rfwd->listen_port, rfwd->connect_host, rfwd->connect_port);
 873         if (type == SSH2_MSG_REQUEST_FAILURE) {
 874                 if (options.exit_on_forward_failure)
 875                         fatal("Error: remote port forwarding failed for "
 876                             "listen port %d", rfwd->listen_port);
 877                 else
 878                         logit("Warning: remote port forwarding failed for "
 879                             "listen port %d", rfwd->listen_port);
 880         }
 881         if (++remote_forward_confirms_received == options.num_remote_forwards) {
 882                 debug("All remote forwarding requests processed");
 883                 if (fork_after_authentication_flag) {
 884                         fork_after_authentication_flag = 0;
 885                         if (daemon(1, 1) < 0)
 886                                 fatal("daemon() failed: %.200s",
 887                                     strerror(errno));
 888                 }
 889         }
 890 }
 891
 892 static void
 893 ssh_init_forwarding(void)
 894 {
 895         int success = 0;
 896         int i;
 897
 898         /* Initiate local TCP/IP port forwardings. */
 899         for (i = 0; i < options.num_local_forwards; i++) {
 900                 debug("Local connections to %.200s:%d forwarded to remote "
 901                     "address %.200s:%d",
 902                     (options.local_forwards[i].listen_host == NULL) ?
 903                     (options.gateway_ports ? "*" : "LOCALHOST") :
 904                     options.local_forwards[i].listen_host,
 905                     options.local_forwards[i].listen_port,
 906                     options.local_forwards[i].connect_host,
 907                     options.local_forwards[i].connect_port);
 908                 success += channel_setup_local_fwd_listener(
 909                     options.local_forwards[i].listen_host,
 910                     options.local_forwards[i].listen_port,
 911                     options.local_forwards[i].connect_host,
 912                     options.local_forwards[i].connect_port,
 913                     options.gateway_ports);
 914         }
 915         if (i > 0 && success != i && options.exit_on_forward_failure)
 916                 fatal("Could not request local forwarding.");
 917         if (i > 0 && success == 0)
 918                 error("Could not request local forwarding.");
 919
 920         /* Initiate remote TCP/IP port forwardings. */
 921         for (i = 0; i < options.num_remote_forwards; i++) {
 922                 debug("Remote connections from %.200s:%d forwarded to "
 923                     "local address %.200s:%d",
 924                     (options.remote_forwards[i].listen_host == NULL) ?
 925                     "LOCALHOST" : options.remote_forwards[i].listen_host,
 926                     options.remote_forwards[i].listen_port,
 927                     options.remote_forwards[i].connect_host,
 928                     options.remote_forwards[i].connect_port);
 929                 if (channel_request_remote_forwarding(
 930                     options.remote_forwards[i].listen_host,
 931                     options.remote_forwards[i].listen_port,
 932                     options.remote_forwards[i].connect_host,
 933                     options.remote_forwards[i].connect_port) < 0) {
 934                         if (options.exit_on_forward_failure)
 935                                 fatal("Could not request remote forwarding.");
 936                         else
 937                                 logit("Warning: Could not request remote "
 938                                     "forwarding.");
 939                 }
 940                 client_register_global_confirm(ssh_confirm_remote_forward,
 941                     &options.remote_forwards[i]);
 942         }
 943
 944         /* Initiate tunnel forwarding. */
 945         if (options.tun_open != SSH_TUNMODE_NO) {
 946                 if (client_request_tun_fwd(options.tun_open,
 947                     options.tun_local, options.tun_remote) == -1) {
 948                         if (options.exit_on_forward_failure)
 949                                 fatal("Could not request tunnel forwarding.");
 950                         else
 951                                 error("Could not request tunnel forwarding.");
 952                 }
 953         }
 954 }
 955
 956 static void
 957 check_agent_present(void)
 958 {
 959         if (options.forward_agent) {
 960                 /* Clear agent forwarding if we don't have an agent. */
 961                 if (!ssh_agent_present())
 962                         options.forward_agent = 0;
 963         }
 964 }
 965
 966 static int
 967 ssh_session(void)
 968 {
 969         int type;
 970         int interactive = 0;
 971         int have_tty = 0;
 972         struct winsize ws;
 973         char *cp;
 974         const char *display;
 975
 976         /* Enable compression if requested. */
 977         if (options.compression) {
 978                 debug("Requesting compression at level %d.",
 979                     options.compression_level);
 980
 981                 if (options.compression_level < 1 ||
 982                     options.compression_level > 9)
 983                         fatal("Compression level must be from 1 (fast) to "
 984                             "9 (slow, best).");
 985
 986                 /* Send the request. */
 987                 packet_start(SSH_CMSG_REQUEST_COMPRESSION);
 988                 packet_put_int(options.compression_level);
 989                 packet_send();
 990                 packet_write_wait();
 991                 type = packet_read();
 992                 if (type == SSH_SMSG_SUCCESS)
 993                         packet_start_compression(options.compression_level);
 994                 else if (type == SSH_SMSG_FAILURE)
 995                         logit("Warning: Remote host refused compression.");
 996                 else
 997                         packet_disconnect("Protocol error waiting for "
 998                             "compression response.");
 999         }
1000         /* Allocate a pseudo tty if appropriate. */
1001         if (tty_flag) {
1002                 debug("Requesting pty.");
1003
1004                 /* Start the packet. */
1005                 packet_start(SSH_CMSG_REQUEST_PTY);
1006
1007                 /* Store TERM in the packet.  There is no limit on the
1008                    length of the string. */
1009                 cp = getenv("TERM");
1010                 if (!cp)
1011                         cp = "";
1012                 packet_put_cstring(cp);
1013
1014                 /* Store window size in the packet. */
1015                 if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
1016                         memset(&ws, 0, sizeof(ws));
1017                 packet_put_int((u_int)ws.ws_row);
1018                 packet_put_int((u_int)ws.ws_col);
1019                 packet_put_int((u_int)ws.ws_xpixel);
1020                 packet_put_int((u_int)ws.ws_ypixel);
1021
1022                 /* Store tty modes in the packet. */
1023                 tty_make_modes(fileno(stdin), NULL);
1024
1025                 /* Send the packet, and wait for it to leave. */
1026                 packet_send();
1027                 packet_write_wait();
1028
1029                 /* Read response from the server. */
1030                 type = packet_read();
1031                 if (type == SSH_SMSG_SUCCESS) {
1032                         interactive = 1;
1033                         have_tty = 1;
1034                 } else if (type == SSH_SMSG_FAILURE)
1035                         logit("Warning: Remote host failed or refused to "
1036                             "allocate a pseudo tty.");
1037                 else
1038                         packet_disconnect("Protocol error waiting for pty "
1039                             "request response.");
1040         }
1041         /* Request X11 forwarding if enabled and DISPLAY is set. */
1042         display = getenv("DISPLAY");
1043         if (options.forward_x11 && display != NULL) {
1044                 char *proto, *data;
1045                 /* Get reasonable local authentication information. */
1046                 client_x11_get_proto(display, options.xauth_location,
1047                     options.forward_x11_trusted, &proto, &data);
1048                 /* Request forwarding with authentication spoofing. */
1049                 debug("Requesting X11 forwarding with authentication "
1050                     "spoofing.");
1051                 x11_request_forwarding_with_spoofing(0, display, proto, data);
1052
1053                 /* Read response from the server. */
1054                 type = packet_read();
1055                 if (type == SSH_SMSG_SUCCESS) {
1056                         interactive = 1;
1057                 } else if (type == SSH_SMSG_FAILURE) {
1058                         logit("Warning: Remote host denied X11 forwarding.");
1059                 } else {
1060                         packet_disconnect("Protocol error waiting for X11 "
1061                             "forwarding");
1062                 }
1063         }
1064         /* Tell the packet module whether this is an interactive session. */
1065         packet_set_interactive(interactive);
1066
1067         /* Request authentication agent forwarding if appropriate. */
1068         check_agent_present();
1069
1070         if (options.forward_agent) {
1071                 debug("Requesting authentication agent forwarding.");
1072                 auth_request_forwarding();
1073
1074                 /* Read response from the server. */
1075                 type = packet_read();
1076                 packet_check_eom();
1077                 if (type != SSH_SMSG_SUCCESS)
1078                         logit("Warning: Remote host denied authentication agent forwarding.");
1079         }
1080
1081         /* Initiate port forwardings. */
1082         ssh_init_forwarding();
1083
1084         /* Execute a local command */
1085         if (options.local_command != NULL &&
1086             options.permit_local_command)
1087                 ssh_local_cmd(options.local_command);
1088
1089         /*
1090          * If requested and we are not interested in replies to remote
1091          * forwarding requests, then let ssh continue in the background.
1092          */
1093         if (fork_after_authentication_flag &&
1094             (!options.exit_on_forward_failure ||
1095             options.num_remote_forwards == 0)) {
1096                 fork_after_authentication_flag = 0;
1097                 if (daemon(1, 1) < 0)
1098                         fatal("daemon() failed: %.200s", strerror(errno));
1099         }
1100
1101         /*
1102          * If a command was specified on the command line, execute the
1103          * command now. Otherwise request the server to start a shell.
1104          */
1105         if (buffer_len(&command) > 0) {
1106                 int len = buffer_len(&command);
1107                 if (len > 900)
1108                         len = 900;
1109                 debug("Sending command: %.*s", len,
1110                     (u_char *)buffer_ptr(&command));
1111                 packet_start(SSH_CMSG_EXEC_CMD);
1112                 packet_put_string(buffer_ptr(&command), buffer_len(&command));
1113                 packet_send();
1114                 packet_write_wait();
1115         } else {
1116                 debug("Requesting shell.");
1117                 packet_start(SSH_CMSG_EXEC_SHELL);
1118                 packet_send();
1119                 packet_write_wait();
1120         }
1121
1122         /* Enter the interactive session. */
1123         return client_loop(have_tty, tty_flag ?
1124             options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1125 }
1126
1127 /* request pty/x11/agent/tcpfwd/shell for channel */
1128 static void
1129 ssh_session2_setup(int id, void *arg)
1130 {
1131         extern char **environ;
1132         const char *display;
1133         int interactive = tty_flag;
1134
1135         display = getenv("DISPLAY");
1136         if (options.forward_x11 && display != NULL) {
1137                 char *proto, *data;
1138                 /* Get reasonable local authentication information. */
1139                 client_x11_get_proto(display, options.xauth_location,
1140                     options.forward_x11_trusted, &proto, &data);
1141                 /* Request forwarding with authentication spoofing. */
1142                 debug("Requesting X11 forwarding with authentication "
1143                     "spoofing.");
1144                 x11_request_forwarding_with_spoofing(id, display, proto, data);
1145                 interactive = 1;
1146                 /* XXX wait for reply */
1147         }
1148
1149         check_agent_present();
1150         if (options.forward_agent) {
1151                 debug("Requesting authentication agent forwarding.");
1152                 channel_request_start(id, "auth-agent-req@openssh.com", 0);
1153                 packet_send();
1154         }
1155
1156         client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1157             NULL, fileno(stdin), &command, environ);
1158
1159         packet_set_interactive(interactive);
1160 }
1161
1162 /* open new channel for a session */
1163 static int
1164 ssh_session2_open(void)
1165 {
1166         Channel *c;
1167         int window, packetmax, in, out, err;
1168
1169         if (stdin_null_flag) {
1170                 in = open(_PATH_DEVNULL, O_RDONLY);
1171         } else {
1172                 in = dup(STDIN_FILENO);
1173         }
1174         out = dup(STDOUT_FILENO);
1175         err = dup(STDERR_FILENO);
1176
1177         if (in < 0 || out < 0 || err < 0)
1178                 fatal("dup() in/out/err failed");
1179
1180         /* enable nonblocking unless tty */
1181         if (!isatty(in))
1182                 set_nonblock(in);
1183         if (!isatty(out))
1184                 set_nonblock(out);
1185         if (!isatty(err))
1186                 set_nonblock(err);
1187
1188         window = CHAN_SES_WINDOW_DEFAULT;
1189         packetmax = CHAN_SES_PACKET_DEFAULT;
1190         if (tty_flag) {
1191                 window >>= 1;
1192                 packetmax >>= 1;
1193         }
1194         c = channel_new(
1195             "session", SSH_CHANNEL_OPENING, in, out, err,
1196             window, packetmax, CHAN_EXTENDED_WRITE,
1197             "client-session", /*nonblock*/0);
1198
1199         debug3("ssh_session2_open: channel_new: %d", c->self);
1200
1201         channel_send_open(c->self);
1202         if (!no_shell_flag)
1203                 channel_register_open_confirm(c->self,
1204                     ssh_session2_setup, NULL);
1205
1206         return c->self;
1207 }
1208
1209 static int
1210 ssh_session2(void)
1211 {
1212         int id = -1;
1213
1214         /* XXX should be pre-session */
1215         ssh_init_forwarding();
1216
1217         if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
1218                 id = ssh_session2_open();
1219
1220         /* If we don't expect to open a new session, then disallow it */
1221         if (options.control_master == SSHCTL_MASTER_NO) {
1222                 debug("Requesting no-more-sessions@openssh.com");
1223                 packet_start(SSH2_MSG_GLOBAL_REQUEST);
1224                 packet_put_cstring("no-more-sessions@openssh.com");
1225                 packet_put_char(0);
1226                 packet_send();
1227         }
1228
1229         /* Execute a local command */
1230         if (options.local_command != NULL &&
1231             options.permit_local_command)
1232                 ssh_local_cmd(options.local_command);
1233
1234         /* Start listening for multiplex clients */
1235         muxserver_listen();
1236
1237         /* If requested, let ssh continue in the background. */
1238         if (fork_after_authentication_flag) {
1239                 fork_after_authentication_flag = 0;
1240                 if (daemon(1, 1) < 0)
1241                         fatal("daemon() failed: %.200s", strerror(errno));
1242         }
1243
1244         return client_loop(tty_flag, tty_flag ?
1245             options.escape_char : SSH_ESCAPECHAR_NONE, id);
1246 }
1247
1248 static void
1249 load_public_identity_files(void)
1250 {
1251         char *filename, *cp, thishost[NI_MAXHOST];
1252         char *pwdir = NULL, *pwname = NULL;
1253         int i = 0;
1254         Key *public;
1255         struct passwd *pw;
1256 #ifdef SMARTCARD
1257         Key **keys;
1258
1259         if (options.smartcard_device != NULL &&
1260             options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
1261             (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL) {
1262                 int count = 0;
1263                 for (i = 0; keys[i] != NULL; i++) {
1264                         count++;
1265                         memmove(&options.identity_files[1],
1266                             &options.identity_files[0],
1267                             sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1));
1268                         memmove(&options.identity_keys[1],
1269                             &options.identity_keys[0],
1270                             sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1));
1271                         options.num_identity_files++;
1272                         options.identity_keys[0] = keys[i];
1273                         options.identity_files[0] = sc_get_key_label(keys[i]);
1274                 }
1275                 if (options.num_identity_files > SSH_MAX_IDENTITY_FILES)
1276                         options.num_identity_files = SSH_MAX_IDENTITY_FILES;
1277                 i = count;
1278                 xfree(keys);
1279         }
1280 #endif /* SMARTCARD */
1281         if ((pw = getpwuid(original_real_uid)) == NULL)
1282                 fatal("load_public_identity_files: getpwuid failed");
1283         pwname = xstrdup(pw->pw_name);
1284         pwdir = xstrdup(pw->pw_dir);
1285         if (gethostname(thishost, sizeof(thishost)) == -1)
1286                 fatal("load_public_identity_files: gethostname: %s",
1287                     strerror(errno));
1288         for (; i < options.num_identity_files; i++) {
1289                 cp = tilde_expand_filename(options.identity_files[i],
1290                     original_real_uid);
1291                 filename = percent_expand(cp, "d", pwdir,
1292                     "u", pwname, "l", thishost, "h", host,
1293                     "r", options.user, (char *)NULL);
1294                 xfree(cp);
1295                 public = key_load_public(filename, NULL);
1296                 debug("identity file %s type %d", filename,
1297                     public ? public->type : -1);
1298                 xfree(options.identity_files[i]);
1299                 options.identity_files[i] = filename;
1300                 options.identity_keys[i] = public;
1301         }
1302         bzero(pwname, strlen(pwname));
1303         xfree(pwname);
1304         bzero(pwdir, strlen(pwdir));
1305         xfree(pwdir);
1306 }