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Annotation of src/usr.bin/ssh/ssh.c, Revision 1.260

1.1       deraadt     1: /*
1.32      deraadt     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:  *
1.64      deraadt     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.
1.202     markus     16:  * Copyright (c) 2000, 2001, 2002, 2003 Markus Friedl.  All rights reserved.
1.64      deraadt    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.
1.32      deraadt    40:  */
1.1       deraadt    41:
                     42: #include "includes.h"
1.260   ! stevesk    43: RCSID("$OpenBSD: ssh.c,v 1.259 2006/02/08 14:31:30 stevesk Exp $");
1.259     stevesk    44:
                     45: #include <sys/resource.h>
1.260   ! stevesk    46: #include <sys/ioctl.h>
1.258     stevesk    47:
                     48: #include <paths.h>
1.49      markus     49:
                     50: #include <openssl/evp.h>
1.72      markus     51: #include <openssl/err.h>
1.1       deraadt    52:
1.84      markus     53: #include "ssh.h"
                     54: #include "ssh1.h"
                     55: #include "ssh2.h"
                     56: #include "compat.h"
                     57: #include "cipher.h"
1.1       deraadt    58: #include "xmalloc.h"
                     59: #include "packet.h"
                     60: #include "buffer.h"
1.214     djm        61: #include "bufaux.h"
1.123     markus     62: #include "channels.h"
1.49      markus     63: #include "key.h"
1.58      markus     64: #include "authfd.h"
1.49      markus     65: #include "authfile.h"
1.83      markus     66: #include "pathnames.h"
1.214     djm        67: #include "dispatch.h"
1.81      markus     68: #include "clientloop.h"
1.84      markus     69: #include "log.h"
                     70: #include "readconf.h"
                     71: #include "sshconnect.h"
                     72: #include "misc.h"
1.95      markus     73: #include "kex.h"
                     74: #include "mac.h"
1.213     deraadt    75: #include "sshpty.h"
1.212     djm        76: #include "match.h"
1.214     djm        77: #include "msg.h"
                     78: #include "monitor_fdpass.h"
1.225     dtucker    79: #include "uidswap.h"
1.49      markus     80:
1.127     markus     81: #ifdef SMARTCARD
                     82: #include "scard.h"
1.137     jakob      83: #endif
1.127     markus     84:
1.49      markus     85: extern char *__progname;
1.1       deraadt    86:
1.31      markus     87: /* Flag indicating whether debug mode is on.  This can be set on the command line. */
1.1       deraadt    88: int debug_flag = 0;
                     89:
1.46      markus     90: /* Flag indicating whether a tty should be allocated */
1.1       deraadt    91: int tty_flag = 0;
1.79      markus     92: int no_tty_flag = 0;
                     93: int force_tty_flag = 0;
1.1       deraadt    94:
1.45      markus     95: /* don't exec a shell */
                     96: int no_shell_flag = 0;
                     97:
1.33      markus     98: /*
                     99:  * Flag indicating that nothing should be read from stdin.  This can be set
                    100:  * on the command line.
                    101:  */
1.1       deraadt   102: int stdin_null_flag = 0;
                    103:
1.33      markus    104: /*
                    105:  * Flag indicating that ssh should fork after authentication.  This is useful
1.172     deraadt   106:  * so that the passphrase can be entered manually, and then ssh goes to the
1.33      markus    107:  * background.
                    108:  */
1.1       deraadt   109: int fork_after_authentication_flag = 0;
                    110:
1.33      markus    111: /*
                    112:  * General data structure for command line options and options configurable
                    113:  * in configuration files.  See readconf.h.
                    114:  */
1.1       deraadt   115: Options options;
                    116:
1.139     markus    117: /* optional user configfile */
                    118: char *config = NULL;
                    119:
1.33      markus    120: /*
                    121:  * Name of the host we are connecting to.  This is the name given on the
                    122:  * command line, or the HostName specified for the user-supplied name in a
                    123:  * configuration file.
                    124:  */
1.1       deraadt   125: char *host;
                    126:
1.22      provos    127: /* socket address the host resolves to */
1.37      markus    128: struct sockaddr_storage hostaddr;
1.1       deraadt   129:
1.112     markus    130: /* Private host keys. */
1.173     markus    131: Sensitive sensitive_data;
1.1       deraadt   132:
1.10      dugsong   133: /* Original real UID. */
                    134: uid_t original_real_uid;
1.177     markus    135: uid_t original_effective_uid;
1.1       deraadt   136:
1.45      markus    137: /* command to be executed */
                    138: Buffer command;
                    139:
1.85      djm       140: /* Should we execute a command or invoke a subsystem? */
                    141: int subsystem_flag = 0;
                    142:
1.170     markus    143: /* # of replies received for global requests */
                    144: static int client_global_request_id = 0;
                    145:
1.186     djm       146: /* pid of proxycommand child process */
                    147: pid_t proxy_command_pid = 0;
                    148:
1.214     djm       149: /* fd to control socket */
                    150: int control_fd = -1;
                    151:
1.229     djm       152: /* Multiplexing control command */
1.240     djm       153: static u_int mux_command = 0;
1.229     djm       154:
1.214     djm       155: /* Only used in control client mode */
                    156: volatile sig_atomic_t control_client_terminate = 0;
                    157: u_int control_server_pid = 0;
                    158:
1.1       deraadt   159: /* Prints a help message to the user.  This function never returns. */
                    160:
1.126     itojun    161: static void
1.93      itojun    162: usage(void)
1.1       deraadt   163: {
1.208     markus    164:        fprintf(stderr,
1.230     jmc       165: "usage: ssh [-1246AaCfgkMNnqsTtVvXxY] [-b bind_address] [-c cipher_spec]\n"
1.251     jmc       166: "           [-D [bind_address:]port] [-e escape_char] [-F configfile]\n"
1.233     jmc       167: "           [-i identity_file] [-L [bind_address:]port:host:hostport]\n"
1.232     djm       168: "           [-l login_name] [-m mac_spec] [-O ctl_cmd] [-o option] [-p port]\n"
1.233     jmc       169: "           [-R [bind_address:]port:host:hostport] [-S ctl_path]\n"
1.255     reyk      170: "           [-w tunnel:tunnel] [user@]hostname [command]\n"
1.208     markus    171:        );
1.257     dtucker   172:        exit(255);
1.1       deraadt   173: }
                    174:
1.126     itojun    175: static int ssh_session(void);
                    176: static int ssh_session2(void);
                    177: static void load_public_identity_files(void);
1.214     djm       178: static void control_client(const char *path);
1.45      markus    179:
1.32      deraadt   180: /*
                    181:  * Main program for the ssh client.
                    182:  */
1.2       provos    183: int
                    184: main(int ac, char **av)
1.1       deraadt   185: {
1.178     markus    186:        int i, opt, exit_status;
1.205     markus    187:        char *p, *cp, *line, buf[256];
1.31      markus    188:        struct stat st;
1.98      markus    189:        struct passwd *pw;
1.45      markus    190:        int dummy;
1.144     stevesk   191:        extern int optind, optreset;
                    192:        extern char *optarg;
1.244     djm       193:        struct servent *sp;
1.232     djm       194:        Forward fwd;
1.250     djm       195:
                    196:        /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
                    197:        sanitise_stdfd();
1.31      markus    198:
1.33      markus    199:        /*
                    200:         * Save the original real uid.  It will be needed later (uid-swapping
                    201:         * may clobber the real uid).
                    202:         */
1.31      markus    203:        original_real_uid = getuid();
                    204:        original_effective_uid = geteuid();
                    205:
1.184     stevesk   206:        /*
                    207:         * Use uid-swapping to give up root privileges for the duration of
                    208:         * option processing.  We will re-instantiate the rights when we are
                    209:         * ready to create the privileged port, and will permanently drop
                    210:         * them when the port has been created (actually, when the connection
                    211:         * has been made, as we may need to create the port several times).
                    212:         */
                    213:        PRIV_END;
                    214:
1.31      markus    215:        /* If we are installed setuid root be careful to not drop core. */
                    216:        if (original_real_uid != original_effective_uid) {
                    217:                struct rlimit rlim;
                    218:                rlim.rlim_cur = rlim.rlim_max = 0;
                    219:                if (setrlimit(RLIMIT_CORE, &rlim) < 0)
                    220:                        fatal("setrlimit failed: %.100s", strerror(errno));
1.1       deraadt   221:        }
1.107     markus    222:        /* Get user data. */
                    223:        pw = getpwuid(original_real_uid);
                    224:        if (!pw) {
1.191     itojun    225:                logit("You don't exist, go away!");
1.257     dtucker   226:                exit(255);
1.107     markus    227:        }
                    228:        /* Take a copy of the returned structure. */
                    229:        pw = pwcopy(pw);
1.31      markus    230:
1.33      markus    231:        /*
                    232:         * Set our umask to something reasonable, as some files are created
                    233:         * with the default umask.  This will make them world-readable but
                    234:         * writable only by the owner, which is ok for all files for which we
                    235:         * don't set the modes explicitly.
                    236:         */
1.31      markus    237:        umask(022);
                    238:
                    239:        /* Initialize option structure to indicate that no values have been set. */
                    240:        initialize_options(&options);
                    241:
                    242:        /* Parse command-line arguments. */
                    243:        host = NULL;
                    244:
1.128     fgsch     245: again:
                    246:        while ((opt = getopt(ac, av,
1.255     reyk      247:            "1246ab:c:e:fgi:kl:m:no:p:qstvxACD:F:I:L:MNO:PR:S:TVw:XY")) != -1) {
1.31      markus    248:                switch (opt) {
1.91      jakob     249:                case '1':
                    250:                        options.protocol = SSH_PROTO_1;
                    251:                        break;
1.47      markus    252:                case '2':
                    253:                        options.protocol = SSH_PROTO_2;
                    254:                        break;
1.37      markus    255:                case '4':
1.196     djm       256:                        options.address_family = AF_INET;
1.37      markus    257:                        break;
                    258:                case '6':
1.196     djm       259:                        options.address_family = AF_INET6;
1.37      markus    260:                        break;
1.31      markus    261:                case 'n':
                    262:                        stdin_null_flag = 1;
                    263:                        break;
                    264:                case 'f':
                    265:                        fork_after_authentication_flag = 1;
                    266:                        stdin_null_flag = 1;
                    267:                        break;
                    268:                case 'x':
                    269:                        options.forward_x11 = 0;
                    270:                        break;
                    271:                case 'X':
                    272:                        options.forward_x11 = 1;
                    273:                        break;
1.202     markus    274:                case 'Y':
                    275:                        options.forward_x11 = 1;
                    276:                        options.forward_x11_trusted = 1;
                    277:                        break;
1.31      markus    278:                case 'g':
                    279:                        options.gateway_ports = 1;
                    280:                        break;
1.229     djm       281:                case 'O':
                    282:                        if (strcmp(optarg, "check") == 0)
                    283:                                mux_command = SSHMUX_COMMAND_ALIVE_CHECK;
                    284:                        else if (strcmp(optarg, "exit") == 0)
                    285:                                mux_command = SSHMUX_COMMAND_TERMINATE;
                    286:                        else
                    287:                                fatal("Invalid multiplex command.");
                    288:                        break;
1.183     stevesk   289:                case 'P':       /* deprecated */
1.31      markus    290:                        options.use_privileged_port = 0;
                    291:                        break;
                    292:                case 'a':
                    293:                        options.forward_agent = 0;
1.53      markus    294:                        break;
                    295:                case 'A':
                    296:                        options.forward_agent = 1;
1.31      markus    297:                        break;
                    298:                case 'k':
1.204     dtucker   299:                        options.gss_deleg_creds = 0;
1.31      markus    300:                        break;
                    301:                case 'i':
                    302:                        if (stat(optarg, &st) < 0) {
1.128     fgsch     303:                                fprintf(stderr, "Warning: Identity file %s "
1.231     otto      304:                                    "not accessible: %s.\n", optarg,
                    305:                                    strerror(errno));
1.31      markus    306:                                break;
                    307:                        }
1.128     fgsch     308:                        if (options.num_identity_files >=
                    309:                            SSH_MAX_IDENTITY_FILES)
                    310:                                fatal("Too many identity files specified "
                    311:                                    "(max %d)", SSH_MAX_IDENTITY_FILES);
                    312:                        options.identity_files[options.num_identity_files++] =
                    313:                            xstrdup(optarg);
1.31      markus    314:                        break;
1.127     markus    315:                case 'I':
                    316: #ifdef SMARTCARD
1.133     markus    317:                        options.smartcard_device = xstrdup(optarg);
1.137     jakob     318: #else
1.127     markus    319:                        fprintf(stderr, "no support for smartcards.\n");
1.137     jakob     320: #endif
1.127     markus    321:                        break;
1.31      markus    322:                case 't':
1.79      markus    323:                        if (tty_flag)
                    324:                                force_tty_flag = 1;
1.31      markus    325:                        tty_flag = 1;
                    326:                        break;
                    327:                case 'v':
1.197     markus    328:                        if (debug_flag == 0) {
1.66      markus    329:                                debug_flag = 1;
                    330:                                options.log_level = SYSLOG_LEVEL_DEBUG1;
1.197     markus    331:                        } else {
                    332:                                if (options.log_level < SYSLOG_LEVEL_DEBUG3)
                    333:                                        options.log_level++;
1.66      markus    334:                                break;
1.197     markus    335:                        }
1.227     deraadt   336:                        /* FALLTHROUGH */
1.31      markus    337:                case 'V':
1.209     markus    338:                        fprintf(stderr, "%s, %s\n",
                    339:                            SSH_VERSION, SSLeay_version(SSLEAY_VERSION));
1.31      markus    340:                        if (opt == 'V')
                    341:                                exit(0);
                    342:                        break;
1.255     reyk      343:                case 'w':
1.256     reyk      344:                        if (options.tun_open == -1)
                    345:                                options.tun_open = SSH_TUNMODE_DEFAULT;
1.255     reyk      346:                        options.tun_local = a2tun(optarg, &options.tun_remote);
1.256     reyk      347:                        if (options.tun_local == SSH_TUNID_ERR) {
1.255     reyk      348:                                fprintf(stderr, "Bad tun device '%s'\n", optarg);
1.257     dtucker   349:                                exit(255);
1.255     reyk      350:                        }
                    351:                        break;
1.31      markus    352:                case 'q':
                    353:                        options.log_level = SYSLOG_LEVEL_QUIET;
                    354:                        break;
                    355:                case 'e':
                    356:                        if (optarg[0] == '^' && optarg[2] == 0 &&
1.128     fgsch     357:                            (u_char) optarg[1] >= 64 &&
                    358:                            (u_char) optarg[1] < 128)
1.78      markus    359:                                options.escape_char = (u_char) optarg[1] & 31;
1.31      markus    360:                        else if (strlen(optarg) == 1)
1.78      markus    361:                                options.escape_char = (u_char) optarg[0];
1.31      markus    362:                        else if (strcmp(optarg, "none") == 0)
1.119     stevesk   363:                                options.escape_char = SSH_ESCAPECHAR_NONE;
1.31      markus    364:                        else {
1.128     fgsch     365:                                fprintf(stderr, "Bad escape character '%s'.\n",
                    366:                                    optarg);
1.257     dtucker   367:                                exit(255);
1.31      markus    368:                        }
                    369:                        break;
                    370:                case 'c':
1.49      markus    371:                        if (ciphers_valid(optarg)) {
                    372:                                /* SSH2 only */
                    373:                                options.ciphers = xstrdup(optarg);
1.224     markus    374:                                options.cipher = SSH_CIPHER_INVALID;
1.49      markus    375:                        } else {
                    376:                                /* SSH1 only */
1.74      markus    377:                                options.cipher = cipher_number(optarg);
                    378:                                if (options.cipher == -1) {
1.128     fgsch     379:                                        fprintf(stderr,
                    380:                                            "Unknown cipher type '%s'\n",
                    381:                                            optarg);
1.257     dtucker   382:                                        exit(255);
1.49      markus    383:                                }
1.128     fgsch     384:                                if (options.cipher == SSH_CIPHER_3DES)
1.74      markus    385:                                        options.ciphers = "3des-cbc";
1.128     fgsch     386:                                else if (options.cipher == SSH_CIPHER_BLOWFISH)
1.74      markus    387:                                        options.ciphers = "blowfish-cbc";
1.128     fgsch     388:                                else
1.74      markus    389:                                        options.ciphers = (char *)-1;
1.95      markus    390:                        }
                    391:                        break;
                    392:                case 'm':
                    393:                        if (mac_valid(optarg))
                    394:                                options.macs = xstrdup(optarg);
                    395:                        else {
1.128     fgsch     396:                                fprintf(stderr, "Unknown mac type '%s'\n",
                    397:                                    optarg);
1.257     dtucker   398:                                exit(255);
1.31      markus    399:                        }
                    400:                        break;
1.214     djm       401:                case 'M':
1.242     djm       402:                        if (options.control_master == SSHCTL_MASTER_YES)
                    403:                                options.control_master = SSHCTL_MASTER_ASK;
                    404:                        else
                    405:                                options.control_master = SSHCTL_MASTER_YES;
1.214     djm       406:                        break;
1.31      markus    407:                case 'p':
1.113     stevesk   408:                        options.port = a2port(optarg);
                    409:                        if (options.port == 0) {
1.109     markus    410:                                fprintf(stderr, "Bad port '%s'\n", optarg);
1.257     dtucker   411:                                exit(255);
1.109     markus    412:                        }
1.31      markus    413:                        break;
                    414:                case 'l':
                    415:                        options.user = optarg;
                    416:                        break;
1.141     stevesk   417:
                    418:                case 'L':
1.232     djm       419:                        if (parse_forward(&fwd, optarg))
                    420:                                add_local_forward(&options, &fwd);
                    421:                        else {
1.128     fgsch     422:                                fprintf(stderr,
1.232     djm       423:                                    "Bad local forwarding specification '%s'\n",
1.128     fgsch     424:                                    optarg);
1.257     dtucker   425:                                exit(255);
1.31      markus    426:                        }
1.232     djm       427:                        break;
                    428:
                    429:                case 'R':
                    430:                        if (parse_forward(&fwd, optarg)) {
                    431:                                add_remote_forward(&options, &fwd);
                    432:                        } else {
1.128     fgsch     433:                                fprintf(stderr,
1.232     djm       434:                                    "Bad remote forwarding specification "
                    435:                                    "'%s'\n", optarg);
1.257     dtucker   436:                                exit(255);
1.31      markus    437:                        }
                    438:                        break;
1.108     markus    439:
                    440:                case 'D':
1.232     djm       441:                        cp = p = xstrdup(optarg);
                    442:                        memset(&fwd, '\0', sizeof(fwd));
                    443:                        fwd.connect_host = "socks";
                    444:                        if ((fwd.listen_host = hpdelim(&cp)) == NULL) {
                    445:                                fprintf(stderr, "Bad dynamic forwarding "
                    446:                                    "specification '%.100s'\n", optarg);
1.257     dtucker   447:                                exit(255);
1.232     djm       448:                        }
                    449:                        if (cp != NULL) {
                    450:                                fwd.listen_port = a2port(cp);
                    451:                                fwd.listen_host = cleanhostname(fwd.listen_host);
                    452:                        } else {
                    453:                                fwd.listen_port = a2port(fwd.listen_host);
1.249     djm       454:                                fwd.listen_host = NULL;
1.232     djm       455:                        }
                    456:
                    457:                        if (fwd.listen_port == 0) {
1.128     fgsch     458:                                fprintf(stderr, "Bad dynamic port '%s'\n",
                    459:                                    optarg);
1.257     dtucker   460:                                exit(255);
1.109     markus    461:                        }
1.232     djm       462:                        add_local_forward(&options, &fwd);
                    463:                        xfree(p);
1.108     markus    464:                        break;
                    465:
1.31      markus    466:                case 'C':
                    467:                        options.compression = 1;
                    468:                        break;
1.45      markus    469:                case 'N':
                    470:                        no_shell_flag = 1;
                    471:                        no_tty_flag = 1;
                    472:                        break;
                    473:                case 'T':
                    474:                        no_tty_flag = 1;
                    475:                        break;
1.31      markus    476:                case 'o':
                    477:                        dummy = 1;
1.205     markus    478:                        line = xstrdup(optarg);
1.128     fgsch     479:                        if (process_config_line(&options, host ? host : "",
1.205     markus    480:                            line, "command-line", 0, &dummy) != 0)
1.257     dtucker   481:                                exit(255);
1.205     markus    482:                        xfree(line);
1.31      markus    483:                        break;
1.85      djm       484:                case 's':
                    485:                        subsystem_flag = 1;
1.117     markus    486:                        break;
1.214     djm       487:                case 'S':
                    488:                        if (options.control_path != NULL)
                    489:                                free(options.control_path);
                    490:                        options.control_path = xstrdup(optarg);
                    491:                        break;
1.117     markus    492:                case 'b':
                    493:                        options.bind_address = optarg;
1.85      djm       494:                        break;
1.139     markus    495:                case 'F':
                    496:                        config = optarg;
                    497:                        break;
1.31      markus    498:                default:
                    499:                        usage();
1.1       deraadt   500:                }
1.31      markus    501:        }
                    502:
1.128     fgsch     503:        ac -= optind;
                    504:        av += optind;
                    505:
                    506:        if (ac > 0 && !host && **av != '-') {
1.188     markus    507:                if (strrchr(*av, '@')) {
1.128     fgsch     508:                        p = xstrdup(*av);
1.188     markus    509:                        cp = strrchr(p, '@');
1.128     fgsch     510:                        if (cp == NULL || cp == p)
                    511:                                usage();
                    512:                        options.user = p;
                    513:                        *cp = '\0';
                    514:                        host = ++cp;
                    515:                } else
                    516:                        host = *av;
1.189     millert   517:                if (ac > 1) {
                    518:                        optind = optreset = 1;
1.128     fgsch     519:                        goto again;
                    520:                }
1.189     millert   521:                ac--, av++;
1.128     fgsch     522:        }
                    523:
1.31      markus    524:        /* Check that we got a host name. */
                    525:        if (!host)
                    526:                usage();
                    527:
1.54      markus    528:        SSLeay_add_all_algorithms();
1.72      markus    529:        ERR_load_crypto_strings();
1.31      markus    530:
                    531:        /* Initialize the command to execute on remote host. */
                    532:        buffer_init(&command);
1.1       deraadt   533:
1.33      markus    534:        /*
                    535:         * Save the command to execute on the remote host in a buffer. There
                    536:         * is no limit on the length of the command, except by the maximum
                    537:         * packet size.  Also sets the tty flag if there is no command.
                    538:         */
1.128     fgsch     539:        if (!ac) {
1.31      markus    540:                /* No command specified - execute shell on a tty. */
                    541:                tty_flag = 1;
1.85      djm       542:                if (subsystem_flag) {
1.128     fgsch     543:                        fprintf(stderr,
                    544:                            "You must specify a subsystem to invoke.\n");
1.85      djm       545:                        usage();
                    546:                }
1.31      markus    547:        } else {
1.128     fgsch     548:                /* A command has been specified.  Store it into the buffer. */
                    549:                for (i = 0; i < ac; i++) {
                    550:                        if (i)
1.31      markus    551:                                buffer_append(&command, " ", 1);
                    552:                        buffer_append(&command, av[i], strlen(av[i]));
                    553:                }
                    554:        }
                    555:
                    556:        /* Cannot fork to background if no command. */
1.63      markus    557:        if (fork_after_authentication_flag && buffer_len(&command) == 0 && !no_shell_flag)
1.31      markus    558:                fatal("Cannot fork into background without a command to execute.");
                    559:
                    560:        /* Allocate a tty by default if no command specified. */
                    561:        if (buffer_len(&command) == 0)
                    562:                tty_flag = 1;
                    563:
1.180     deraadt   564:        /* Force no tty */
1.75      markus    565:        if (no_tty_flag)
                    566:                tty_flag = 0;
1.31      markus    567:        /* Do not allocate a tty if stdin is not a tty. */
1.236     djm       568:        if ((!isatty(fileno(stdin)) || stdin_null_flag) && !force_tty_flag) {
1.31      markus    569:                if (tty_flag)
1.191     itojun    570:                        logit("Pseudo-terminal will not be allocated because stdin is not a terminal.");
1.31      markus    571:                tty_flag = 0;
                    572:        }
1.45      markus    573:
1.101     markus    574:        /*
                    575:         * Initialize "log" output.  Since we are the client all output
                    576:         * actually goes to stderr.
                    577:         */
1.111     markus    578:        log_init(av[0], options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
                    579:            SYSLOG_FACILITY_USER, 1);
1.31      markus    580:
1.139     markus    581:        /*
                    582:         * Read per-user configuration file.  Ignore the system wide config
                    583:         * file if the user specifies a config file on the command line.
                    584:         */
                    585:        if (config != NULL) {
1.211     djm       586:                if (!read_config_file(config, host, &options, 0))
1.142     stevesk   587:                        fatal("Can't open user config file %.100s: "
                    588:                            "%.100s", config, strerror(errno));
1.139     markus    589:        } else  {
                    590:                snprintf(buf, sizeof buf, "%.100s/%.100s", pw->pw_dir,
                    591:                    _PATH_SSH_USER_CONFFILE);
1.210     djm       592:                (void)read_config_file(buf, host, &options, 1);
1.139     markus    593:
1.145     markus    594:                /* Read systemwide configuration file after use config. */
1.223     deraadt   595:                (void)read_config_file(_PATH_HOST_CONFIG_FILE, host,
1.210     djm       596:                    &options, 0);
1.139     markus    597:        }
1.31      markus    598:
                    599:        /* Fill configuration defaults. */
                    600:        fill_default_options(&options);
                    601:
1.196     djm       602:        channel_set_af(options.address_family);
                    603:
1.31      markus    604:        /* reinit */
1.101     markus    605:        log_init(av[0], options.log_level, SYSLOG_FACILITY_USER, 1);
1.31      markus    606:
                    607:        if (options.user == NULL)
                    608:                options.user = xstrdup(pw->pw_name);
                    609:
                    610:        if (options.hostname != NULL)
                    611:                host = options.hostname;
1.195     markus    612:
                    613:        /* force lowercase for hostkey matching */
                    614:        if (options.host_key_alias != NULL) {
                    615:                for (p = options.host_key_alias; *p; p++)
                    616:                        if (isupper(*p))
                    617:                                *p = tolower(*p);
                    618:        }
1.190     markus    619:
1.246     djm       620:        /* Get default port if port has not been set. */
                    621:        if (options.port == 0) {
                    622:                sp = getservbyname(SSH_SERVICE_NAME, "tcp");
                    623:                options.port = sp ? ntohs(sp->s_port) : SSH_DEFAULT_PORT;
                    624:        }
                    625:
1.190     markus    626:        if (options.proxy_command != NULL &&
                    627:            strcmp(options.proxy_command, "none") == 0)
                    628:                options.proxy_command = NULL;
1.245     djm       629:        if (options.control_path != NULL &&
                    630:            strcmp(options.control_path, "none") == 0)
                    631:                options.control_path = NULL;
1.31      markus    632:
1.214     djm       633:        if (options.control_path != NULL) {
1.241     djm       634:                snprintf(buf, sizeof(buf), "%d", options.port);
                    635:                cp = tilde_expand_filename(options.control_path,
                    636:                    original_real_uid);
                    637:                options.control_path = percent_expand(cp, "p", buf, "h", host,
                    638:                    "r", options.user, (char *)NULL);
                    639:                xfree(cp);
1.214     djm       640:        }
1.240     djm       641:        if (mux_command != 0 && options.control_path == NULL)
                    642:                fatal("No ControlPath specified for \"-O\" command");
1.242     djm       643:        if (options.control_path != NULL)
1.237     jakob     644:                control_client(options.control_path);
1.214     djm       645:
1.77      markus    646:        /* Open a connection to the remote host. */
1.203     djm       647:        if (ssh_connect(host, &hostaddr, options.port,
1.196     djm       648:            options.address_family, options.connection_attempts,
1.177     markus    649:            original_effective_uid == 0 && options.use_privileged_port,
1.179     markus    650:            options.proxy_command) != 0)
1.257     dtucker   651:                exit(255);
1.31      markus    652:
1.33      markus    653:        /*
                    654:         * If we successfully made the connection, load the host private key
                    655:         * in case we will need it later for combined rsa-rhosts
                    656:         * authentication. This must be done before releasing extra
                    657:         * privileges, because the file is only readable by root.
1.174     markus    658:         * If we cannot access the private keys, load the public keys
                    659:         * instead and try to execute the ssh-keysign helper instead.
1.33      markus    660:         */
1.112     markus    661:        sensitive_data.nkeys = 0;
                    662:        sensitive_data.keys = NULL;
1.173     markus    663:        sensitive_data.external_keysign = 0;
1.178     markus    664:        if (options.rhosts_rsa_authentication ||
                    665:            options.hostbased_authentication) {
1.112     markus    666:                sensitive_data.nkeys = 3;
1.180     deraadt   667:                sensitive_data.keys = xmalloc(sensitive_data.nkeys *
                    668:                    sizeof(Key));
1.177     markus    669:
                    670:                PRIV_START;
1.112     markus    671:                sensitive_data.keys[0] = key_load_private_type(KEY_RSA1,
1.105     markus    672:                    _PATH_HOST_KEY_FILE, "", NULL);
1.112     markus    673:                sensitive_data.keys[1] = key_load_private_type(KEY_DSA,
                    674:                    _PATH_HOST_DSA_KEY_FILE, "", NULL);
                    675:                sensitive_data.keys[2] = key_load_private_type(KEY_RSA,
                    676:                    _PATH_HOST_RSA_KEY_FILE, "", NULL);
1.177     markus    677:                PRIV_END;
1.173     markus    678:
1.181     markus    679:                if (options.hostbased_authentication == 1 &&
                    680:                    sensitive_data.keys[0] == NULL &&
1.173     markus    681:                    sensitive_data.keys[1] == NULL &&
                    682:                    sensitive_data.keys[2] == NULL) {
                    683:                        sensitive_data.keys[1] = key_load_public(
                    684:                            _PATH_HOST_DSA_KEY_FILE, NULL);
                    685:                        sensitive_data.keys[2] = key_load_public(
                    686:                            _PATH_HOST_RSA_KEY_FILE, NULL);
                    687:                        sensitive_data.external_keysign = 1;
                    688:                }
1.31      markus    689:        }
1.33      markus    690:        /*
                    691:         * Get rid of any extra privileges that we may have.  We will no
                    692:         * longer need them.  Also, extra privileges could make it very hard
                    693:         * to read identity files and other non-world-readable files from the
                    694:         * user's home directory if it happens to be on a NFS volume where
                    695:         * root is mapped to nobody.
                    696:         */
1.225     dtucker   697:        if (original_effective_uid == 0) {
                    698:                PRIV_START;
                    699:                permanently_set_uid(pw);
                    700:        }
1.31      markus    701:
1.33      markus    702:        /*
                    703:         * Now that we are back to our own permissions, create ~/.ssh
1.254     djm       704:         * directory if it doesn't already exist.
1.33      markus    705:         */
1.138     jakob     706:        snprintf(buf, sizeof buf, "%.100s%s%.100s", pw->pw_dir, strcmp(pw->pw_dir, "/") ? "/" : "", _PATH_SSH_USER_DIR);
1.31      markus    707:        if (stat(buf, &st) < 0)
1.57      djm       708:                if (mkdir(buf, 0700) < 0)
1.31      markus    709:                        error("Could not create directory '%.200s'.", buf);
                    710:
1.104     markus    711:        /* load options.identity_files */
                    712:        load_public_identity_files();
                    713:
                    714:        /* Expand ~ in known host file names. */
                    715:        /* XXX mem-leaks: */
1.72      markus    716:        options.system_hostfile =
                    717:            tilde_expand_filename(options.system_hostfile, original_real_uid);
                    718:        options.user_hostfile =
                    719:            tilde_expand_filename(options.user_hostfile, original_real_uid);
                    720:        options.system_hostfile2 =
                    721:            tilde_expand_filename(options.system_hostfile2, original_real_uid);
                    722:        options.user_hostfile2 =
                    723:            tilde_expand_filename(options.user_hostfile2, original_real_uid);
1.149     markus    724:
                    725:        signal(SIGPIPE, SIG_IGN); /* ignore SIGPIPE early */
1.31      markus    726:
                    727:        /* Log into the remote system.  This never returns if the login fails. */
1.173     markus    728:        ssh_login(&sensitive_data, host, (struct sockaddr *)&hostaddr, pw);
1.31      markus    729:
1.112     markus    730:        /* We no longer need the private host keys.  Clear them now. */
                    731:        if (sensitive_data.nkeys != 0) {
                    732:                for (i = 0; i < sensitive_data.nkeys; i++) {
                    733:                        if (sensitive_data.keys[i] != NULL) {
                    734:                                /* Destroys contents safely */
                    735:                                debug3("clear hostkey %d", i);
                    736:                                key_free(sensitive_data.keys[i]);
                    737:                                sensitive_data.keys[i] = NULL;
                    738:                        }
                    739:                }
                    740:                xfree(sensitive_data.keys);
1.134     markus    741:        }
                    742:        for (i = 0; i < options.num_identity_files; i++) {
                    743:                if (options.identity_files[i]) {
                    744:                        xfree(options.identity_files[i]);
                    745:                        options.identity_files[i] = NULL;
                    746:                }
                    747:                if (options.identity_keys[i]) {
                    748:                        key_free(options.identity_keys[i]);
                    749:                        options.identity_keys[i] = NULL;
                    750:                }
1.112     markus    751:        }
1.31      markus    752:
1.45      markus    753:        exit_status = compat20 ? ssh_session2() : ssh_session();
                    754:        packet_close();
1.186     djm       755:
1.214     djm       756:        if (options.control_path != NULL && control_fd != -1)
                    757:                unlink(options.control_path);
                    758:
1.186     djm       759:        /*
1.203     djm       760:         * Send SIGHUP to proxy command if used. We don't wait() in
1.186     djm       761:         * case it hangs and instead rely on init to reap the child
                    762:         */
                    763:        if (proxy_command_pid > 1)
                    764:                kill(proxy_command_pid, SIGHUP);
                    765:
1.45      markus    766:        return exit_status;
                    767: }
                    768:
1.126     itojun    769: static void
1.70      markus    770: ssh_init_forwarding(void)
                    771: {
1.86      markus    772:        int success = 0;
1.70      markus    773:        int i;
1.86      markus    774:
1.70      markus    775:        /* Initiate local TCP/IP port forwardings. */
                    776:        for (i = 0; i < options.num_local_forwards; i++) {
1.232     djm       777:                debug("Local connections to %.200s:%d forwarded to remote "
                    778:                    "address %.200s:%d",
1.234     deraadt   779:                    (options.local_forwards[i].listen_host == NULL) ?
                    780:                    (options.gateway_ports ? "*" : "LOCALHOST") :
1.232     djm       781:                    options.local_forwards[i].listen_host,
                    782:                    options.local_forwards[i].listen_port,
                    783:                    options.local_forwards[i].connect_host,
                    784:                    options.local_forwards[i].connect_port);
1.158     markus    785:                success += channel_setup_local_fwd_listener(
1.232     djm       786:                    options.local_forwards[i].listen_host,
                    787:                    options.local_forwards[i].listen_port,
                    788:                    options.local_forwards[i].connect_host,
                    789:                    options.local_forwards[i].connect_port,
1.70      markus    790:                    options.gateway_ports);
                    791:        }
1.86      markus    792:        if (i > 0 && success == 0)
                    793:                error("Could not request local forwarding.");
1.70      markus    794:
                    795:        /* Initiate remote TCP/IP port forwardings. */
                    796:        for (i = 0; i < options.num_remote_forwards; i++) {
1.232     djm       797:                debug("Remote connections from %.200s:%d forwarded to "
                    798:                    "local address %.200s:%d",
1.248     djm       799:                    (options.remote_forwards[i].listen_host == NULL) ?
1.253     djm       800:                    "LOCALHOST" : options.remote_forwards[i].listen_host,
1.232     djm       801:                    options.remote_forwards[i].listen_port,
                    802:                    options.remote_forwards[i].connect_host,
                    803:                    options.remote_forwards[i].connect_port);
1.70      markus    804:                channel_request_remote_forwarding(
1.232     djm       805:                    options.remote_forwards[i].listen_host,
                    806:                    options.remote_forwards[i].listen_port,
                    807:                    options.remote_forwards[i].connect_host,
                    808:                    options.remote_forwards[i].connect_port);
1.70      markus    809:        }
                    810: }
                    811:
1.126     itojun    812: static void
1.70      markus    813: check_agent_present(void)
                    814: {
                    815:        if (options.forward_agent) {
1.254     djm       816:                /* Clear agent forwarding if we don't have an agent. */
1.185     stevesk   817:                if (!ssh_agent_present())
1.70      markus    818:                        options.forward_agent = 0;
                    819:        }
                    820: }
                    821:
1.126     itojun    822: static int
1.45      markus    823: ssh_session(void)
                    824: {
                    825:        int type;
                    826:        int interactive = 0;
                    827:        int have_tty = 0;
                    828:        struct winsize ws;
                    829:        char *cp;
1.243     djm       830:        const char *display;
1.45      markus    831:
1.31      markus    832:        /* Enable compression if requested. */
                    833:        if (options.compression) {
                    834:                debug("Requesting compression at level %d.", options.compression_level);
                    835:
                    836:                if (options.compression_level < 1 || options.compression_level > 9)
                    837:                        fatal("Compression level must be from 1 (fast) to 9 (slow, best).");
                    838:
                    839:                /* Send the request. */
                    840:                packet_start(SSH_CMSG_REQUEST_COMPRESSION);
                    841:                packet_put_int(options.compression_level);
                    842:                packet_send();
                    843:                packet_write_wait();
1.156     markus    844:                type = packet_read();
1.31      markus    845:                if (type == SSH_SMSG_SUCCESS)
                    846:                        packet_start_compression(options.compression_level);
                    847:                else if (type == SSH_SMSG_FAILURE)
1.191     itojun    848:                        logit("Warning: Remote host refused compression.");
1.31      markus    849:                else
                    850:                        packet_disconnect("Protocol error waiting for compression response.");
                    851:        }
                    852:        /* Allocate a pseudo tty if appropriate. */
                    853:        if (tty_flag) {
                    854:                debug("Requesting pty.");
                    855:
                    856:                /* Start the packet. */
                    857:                packet_start(SSH_CMSG_REQUEST_PTY);
                    858:
                    859:                /* Store TERM in the packet.  There is no limit on the
                    860:                   length of the string. */
                    861:                cp = getenv("TERM");
                    862:                if (!cp)
                    863:                        cp = "";
1.124     markus    864:                packet_put_cstring(cp);
1.31      markus    865:
                    866:                /* Store window size in the packet. */
                    867:                if (ioctl(fileno(stdin), TIOCGWINSZ, &ws) < 0)
                    868:                        memset(&ws, 0, sizeof(ws));
                    869:                packet_put_int(ws.ws_row);
                    870:                packet_put_int(ws.ws_col);
                    871:                packet_put_int(ws.ws_xpixel);
                    872:                packet_put_int(ws.ws_ypixel);
                    873:
                    874:                /* Store tty modes in the packet. */
1.115     stevesk   875:                tty_make_modes(fileno(stdin), NULL);
1.31      markus    876:
                    877:                /* Send the packet, and wait for it to leave. */
                    878:                packet_send();
                    879:                packet_write_wait();
                    880:
                    881:                /* Read response from the server. */
1.156     markus    882:                type = packet_read();
1.43      markus    883:                if (type == SSH_SMSG_SUCCESS) {
1.31      markus    884:                        interactive = 1;
1.45      markus    885:                        have_tty = 1;
1.43      markus    886:                } else if (type == SSH_SMSG_FAILURE)
1.191     itojun    887:                        logit("Warning: Remote host failed or refused to allocate a pseudo tty.");
1.31      markus    888:                else
                    889:                        packet_disconnect("Protocol error waiting for pty request response.");
                    890:        }
                    891:        /* Request X11 forwarding if enabled and DISPLAY is set. */
1.243     djm       892:        display = getenv("DISPLAY");
                    893:        if (options.forward_x11 && display != NULL) {
1.150     stevesk   894:                char *proto, *data;
1.50      markus    895:                /* Get reasonable local authentication information. */
1.243     djm       896:                client_x11_get_proto(display, options.xauth_location,
                    897:                    options.forward_x11_trusted, &proto, &data);
1.50      markus    898:                /* Request forwarding with authentication spoofing. */
1.31      markus    899:                debug("Requesting X11 forwarding with authentication spoofing.");
1.243     djm       900:                x11_request_forwarding_with_spoofing(0, display, proto, data);
1.31      markus    901:
                    902:                /* Read response from the server. */
1.156     markus    903:                type = packet_read();
1.31      markus    904:                if (type == SSH_SMSG_SUCCESS) {
                    905:                        interactive = 1;
1.50      markus    906:                } else if (type == SSH_SMSG_FAILURE) {
1.191     itojun    907:                        logit("Warning: Remote host denied X11 forwarding.");
1.50      markus    908:                } else {
1.31      markus    909:                        packet_disconnect("Protocol error waiting for X11 forwarding");
1.50      markus    910:                }
1.31      markus    911:        }
                    912:        /* Tell the packet module whether this is an interactive session. */
1.80      markus    913:        packet_set_interactive(interactive);
1.31      markus    914:
                    915:        /* Request authentication agent forwarding if appropriate. */
1.70      markus    916:        check_agent_present();
                    917:
1.31      markus    918:        if (options.forward_agent) {
                    919:                debug("Requesting authentication agent forwarding.");
                    920:                auth_request_forwarding();
                    921:
                    922:                /* Read response from the server. */
1.156     markus    923:                type = packet_read();
1.155     markus    924:                packet_check_eom();
1.31      markus    925:                if (type != SSH_SMSG_SUCCESS)
1.191     itojun    926:                        logit("Warning: Remote host denied authentication agent forwarding.");
1.31      markus    927:        }
                    928:
1.70      markus    929:        /* Initiate port forwardings. */
                    930:        ssh_init_forwarding();
1.34      markus    931:
                    932:        /* If requested, let ssh continue in the background. */
1.48      markus    933:        if (fork_after_authentication_flag)
1.34      markus    934:                if (daemon(1, 1) < 0)
                    935:                        fatal("daemon() failed: %.200s", strerror(errno));
1.31      markus    936:
1.33      markus    937:        /*
                    938:         * If a command was specified on the command line, execute the
                    939:         * command now. Otherwise request the server to start a shell.
                    940:         */
1.31      markus    941:        if (buffer_len(&command) > 0) {
                    942:                int len = buffer_len(&command);
                    943:                if (len > 900)
                    944:                        len = 900;
1.152     stevesk   945:                debug("Sending command: %.*s", len, (u_char *)buffer_ptr(&command));
1.31      markus    946:                packet_start(SSH_CMSG_EXEC_CMD);
                    947:                packet_put_string(buffer_ptr(&command), buffer_len(&command));
                    948:                packet_send();
                    949:                packet_write_wait();
                    950:        } else {
                    951:                debug("Requesting shell.");
                    952:                packet_start(SSH_CMSG_EXEC_SHELL);
                    953:                packet_send();
                    954:                packet_write_wait();
                    955:        }
                    956:
                    957:        /* Enter the interactive session. */
1.119     stevesk   958:        return client_loop(have_tty, tty_flag ?
                    959:            options.escape_char : SSH_ESCAPECHAR_NONE, 0);
1.45      markus    960: }
                    961:
1.126     itojun    962: static void
1.214     djm       963: ssh_subsystem_reply(int type, u_int32_t seq, void *ctxt)
1.89      markus    964: {
                    965:        int id, len;
                    966:
                    967:        id = packet_get_int();
                    968:        len = buffer_len(&command);
1.100     markus    969:        if (len > 900)
                    970:                len = 900;
1.155     markus    971:        packet_check_eom();
1.89      markus    972:        if (type == SSH2_MSG_CHANNEL_FAILURE)
                    973:                fatal("Request for subsystem '%.*s' failed on channel %d",
1.152     stevesk   974:                    len, (u_char *)buffer_ptr(&command), id);
1.170     markus    975: }
                    976:
                    977: void
1.206     markus    978: client_global_request_reply_fwd(int type, u_int32_t seq, void *ctxt)
1.170     markus    979: {
                    980:        int i;
                    981:
                    982:        i = client_global_request_id++;
1.206     markus    983:        if (i >= options.num_remote_forwards)
1.170     markus    984:                return;
                    985:        debug("remote forward %s for: listen %d, connect %s:%d",
                    986:            type == SSH2_MSG_REQUEST_SUCCESS ? "success" : "failure",
1.232     djm       987:            options.remote_forwards[i].listen_port,
                    988:            options.remote_forwards[i].connect_host,
                    989:            options.remote_forwards[i].connect_port);
1.170     markus    990:        if (type == SSH2_MSG_REQUEST_FAILURE)
1.232     djm       991:                logit("Warning: remote port forwarding failed for listen "
                    992:                    "port %d", options.remote_forwards[i].listen_port);
1.89      markus    993: }
                    994:
1.126     itojun    995: static void
1.214     djm       996: ssh_control_listener(void)
1.45      markus    997: {
1.214     djm       998:        struct sockaddr_un addr;
                    999:        mode_t old_umask;
1.223     deraadt  1000:
1.242     djm      1001:        if (options.control_path == NULL ||
                   1002:            options.control_master == SSHCTL_MASTER_NO)
1.214     djm      1003:                return;
                   1004:
1.242     djm      1005:        debug("setting up multiplex master socket");
                   1006:
1.214     djm      1007:        memset(&addr, '\0', sizeof(addr));
                   1008:        addr.sun_family = AF_UNIX;
                   1009:        addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
                   1010:            strlen(options.control_path) + 1;
                   1011:
                   1012:        if (strlcpy(addr.sun_path, options.control_path,
                   1013:            sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
                   1014:                fatal("ControlPath too long");
                   1015:
                   1016:        if ((control_fd = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
1.252     stevesk  1017:                fatal("%s socket(): %s", __func__, strerror(errno));
1.214     djm      1018:
                   1019:        old_umask = umask(0177);
                   1020:        if (bind(control_fd, (struct sockaddr*)&addr, addr.sun_len) == -1) {
                   1021:                control_fd = -1;
1.238     djm      1022:                if (errno == EINVAL || errno == EADDRINUSE)
1.214     djm      1023:                        fatal("ControlSocket %s already exists",
                   1024:                            options.control_path);
                   1025:                else
1.252     stevesk  1026:                        fatal("%s bind(): %s", __func__, strerror(errno));
1.214     djm      1027:        }
                   1028:        umask(old_umask);
1.80      markus   1029:
1.214     djm      1030:        if (listen(control_fd, 64) == -1)
1.252     stevesk  1031:                fatal("%s listen(): %s", __func__, strerror(errno));
1.31      markus   1032:
1.214     djm      1033:        set_nonblock(control_fd);
                   1034: }
1.45      markus   1035:
1.214     djm      1036: /* request pty/x11/agent/tcpfwd/shell for channel */
                   1037: static void
                   1038: ssh_session2_setup(int id, void *arg)
                   1039: {
1.215     djm      1040:        extern char **environ;
1.243     djm      1041:        const char *display;
                   1042:        int interactive = tty_flag;
1.215     djm      1043:
1.248     djm      1044:        display = getenv("DISPLAY");
1.243     djm      1045:        if (options.forward_x11 && display != NULL) {
1.150     stevesk  1046:                char *proto, *data;
1.50      markus   1047:                /* Get reasonable local authentication information. */
1.243     djm      1048:                client_x11_get_proto(display, options.xauth_location,
                   1049:                    options.forward_x11_trusted, &proto, &data);
1.50      markus   1050:                /* Request forwarding with authentication spoofing. */
                   1051:                debug("Requesting X11 forwarding with authentication spoofing.");
1.243     djm      1052:                x11_request_forwarding_with_spoofing(id, display, proto, data);
1.80      markus   1053:                interactive = 1;
1.50      markus   1054:                /* XXX wait for reply */
                   1055:        }
                   1056:
1.70      markus   1057:        check_agent_present();
                   1058:        if (options.forward_agent) {
                   1059:                debug("Requesting authentication agent forwarding.");
                   1060:                channel_request_start(id, "auth-agent-req@openssh.com", 0);
                   1061:                packet_send();
1.212     djm      1062:        }
                   1063:
1.256     reyk     1064:        if (options.tun_open != SSH_TUNMODE_NO) {
1.255     reyk     1065:                Channel *c;
                   1066:                int fd;
                   1067:
                   1068:                debug("Requesting tun.");
1.256     reyk     1069:                if ((fd = tun_open(options.tun_local,
                   1070:                    options.tun_open)) >= 0) {
1.255     reyk     1071:                        c = channel_new("tun", SSH_CHANNEL_OPENING, fd, fd, -1,
                   1072:                            CHAN_TCP_WINDOW_DEFAULT, CHAN_TCP_PACKET_DEFAULT,
                   1073:                            0, "tun", 1);
                   1074:                        c->datagram = 1;
                   1075:                        packet_start(SSH2_MSG_CHANNEL_OPEN);
                   1076:                        packet_put_cstring("tun@openssh.com");
                   1077:                        packet_put_int(c->self);
                   1078:                        packet_put_int(c->local_window_max);
                   1079:                        packet_put_int(c->local_maxpacket);
1.256     reyk     1080:                        packet_put_int(options.tun_open);
1.255     reyk     1081:                        packet_put_int(options.tun_remote);
                   1082:                        packet_send();
                   1083:                }
                   1084:        }
                   1085:
1.214     djm      1086:        client_session2_setup(id, tty_flag, subsystem_flag, getenv("TERM"),
1.215     djm      1087:            NULL, fileno(stdin), &command, environ, &ssh_subsystem_reply);
1.90      markus   1088:
1.80      markus   1089:        packet_set_interactive(interactive);
1.45      markus   1090: }
                   1091:
1.143     markus   1092: /* open new channel for a session */
1.126     itojun   1093: static int
1.143     markus   1094: ssh_session2_open(void)
1.45      markus   1095: {
1.118     markus   1096:        Channel *c;
                   1097:        int window, packetmax, in, out, err;
1.60      markus   1098:
1.62      markus   1099:        if (stdin_null_flag) {
1.93      itojun   1100:                in = open(_PATH_DEVNULL, O_RDONLY);
1.62      markus   1101:        } else {
                   1102:                in = dup(STDIN_FILENO);
                   1103:        }
1.60      markus   1104:        out = dup(STDOUT_FILENO);
                   1105:        err = dup(STDERR_FILENO);
1.45      markus   1106:
                   1107:        if (in < 0 || out < 0 || err < 0)
1.62      markus   1108:                fatal("dup() in/out/err failed");
1.45      markus   1109:
1.69      markus   1110:        /* enable nonblocking unless tty */
                   1111:        if (!isatty(in))
                   1112:                set_nonblock(in);
                   1113:        if (!isatty(out))
                   1114:                set_nonblock(out);
                   1115:        if (!isatty(err))
                   1116:                set_nonblock(err);
                   1117:
1.65      markus   1118:        window = CHAN_SES_WINDOW_DEFAULT;
                   1119:        packetmax = CHAN_SES_PACKET_DEFAULT;
1.164     markus   1120:        if (tty_flag) {
                   1121:                window >>= 1;
                   1122:                packetmax >>= 1;
1.45      markus   1123:        }
1.118     markus   1124:        c = channel_new(
1.45      markus   1125:            "session", SSH_CHANNEL_OPENING, in, out, err,
1.65      markus   1126:            window, packetmax, CHAN_EXTENDED_WRITE,
1.192     markus   1127:            "client-session", /*nonblock*/0);
1.45      markus   1128:
1.143     markus   1129:        debug3("ssh_session2_open: channel_new: %d", c->self);
1.106     markus   1130:
1.122     markus   1131:        channel_send_open(c->self);
1.143     markus   1132:        if (!no_shell_flag)
1.214     djm      1133:                channel_register_confirm(c->self, ssh_session2_setup, NULL);
1.106     markus   1134:
1.118     markus   1135:        return c->self;
1.106     markus   1136: }
                   1137:
1.126     itojun   1138: static int
1.106     markus   1139: ssh_session2(void)
                   1140: {
1.143     markus   1141:        int id = -1;
1.106     markus   1142:
                   1143:        /* XXX should be pre-session */
                   1144:        ssh_init_forwarding();
1.214     djm      1145:        ssh_control_listener();
1.106     markus   1146:
1.143     markus   1147:        if (!no_shell_flag || (datafellows & SSH_BUG_DUMMYCHAN))
                   1148:                id = ssh_session2_open();
1.255     reyk     1149:
                   1150:        /* Execute a local command */
                   1151:        if (options.local_command != NULL &&
                   1152:            options.permit_local_command)
                   1153:                ssh_local_cmd(options.local_command);
1.106     markus   1154:
                   1155:        /* If requested, let ssh continue in the background. */
                   1156:        if (fork_after_authentication_flag)
                   1157:                if (daemon(1, 1) < 0)
                   1158:                        fatal("daemon() failed: %.200s", strerror(errno));
1.31      markus   1159:
1.119     stevesk  1160:        return client_loop(tty_flag, tty_flag ?
                   1161:            options.escape_char : SSH_ESCAPECHAR_NONE, id);
1.72      markus   1162: }
                   1163:
1.126     itojun   1164: static void
1.104     markus   1165: load_public_identity_files(void)
                   1166: {
                   1167:        char *filename;
1.167     markus   1168:        int i = 0;
1.104     markus   1169:        Key *public;
1.167     markus   1170: #ifdef SMARTCARD
                   1171:        Key **keys;
1.104     markus   1172:
1.133     markus   1173:        if (options.smartcard_device != NULL &&
1.167     markus   1174:            options.num_identity_files < SSH_MAX_IDENTITY_FILES &&
                   1175:            (keys = sc_get_keys(options.smartcard_device, NULL)) != NULL ) {
                   1176:                int count = 0;
                   1177:                for (i = 0; keys[i] != NULL; i++) {
                   1178:                        count++;
                   1179:                        memmove(&options.identity_files[1], &options.identity_files[0],
                   1180:                            sizeof(char *) * (SSH_MAX_IDENTITY_FILES - 1));
                   1181:                        memmove(&options.identity_keys[1], &options.identity_keys[0],
                   1182:                            sizeof(Key *) * (SSH_MAX_IDENTITY_FILES - 1));
                   1183:                        options.num_identity_files++;
                   1184:                        options.identity_keys[0] = keys[i];
1.194     markus   1185:                        options.identity_files[0] = sc_get_key_label(keys[i]);
1.167     markus   1186:                }
1.168     markus   1187:                if (options.num_identity_files > SSH_MAX_IDENTITY_FILES)
                   1188:                        options.num_identity_files = SSH_MAX_IDENTITY_FILES;
1.167     markus   1189:                i = count;
                   1190:                xfree(keys);
1.127     markus   1191:        }
1.136     jakob    1192: #endif /* SMARTCARD */
1.131     millert  1193:        for (; i < options.num_identity_files; i++) {
                   1194:                filename = tilde_expand_filename(options.identity_files[i],
                   1195:                    original_real_uid);
                   1196:                public = key_load_public(filename, NULL);
                   1197:                debug("identity file %s type %d", filename,
                   1198:                    public ? public->type : -1);
                   1199:                xfree(options.identity_files[i]);
                   1200:                options.identity_files[i] = filename;
                   1201:                options.identity_keys[i] = public;
                   1202:        }
1.214     djm      1203: }
                   1204:
                   1205: static void
                   1206: control_client_sighandler(int signo)
                   1207: {
                   1208:        control_client_terminate = signo;
                   1209: }
                   1210:
                   1211: static void
                   1212: control_client_sigrelay(int signo)
                   1213: {
                   1214:        if (control_server_pid > 1)
                   1215:                kill(control_server_pid, signo);
                   1216: }
                   1217:
1.220     djm      1218: static int
                   1219: env_permitted(char *env)
                   1220: {
                   1221:        int i;
                   1222:        char name[1024], *cp;
                   1223:
                   1224:        strlcpy(name, env, sizeof(name));
                   1225:        if ((cp = strchr(name, '=')) == NULL)
                   1226:                return (0);
                   1227:
                   1228:        *cp = '\0';
                   1229:
                   1230:        for (i = 0; i < options.num_send_env; i++)
                   1231:                if (match_pattern(name, options.send_env[i]))
                   1232:                        return (1);
                   1233:
                   1234:        return (0);
                   1235: }
                   1236:
1.214     djm      1237: static void
                   1238: control_client(const char *path)
                   1239: {
                   1240:        struct sockaddr_un addr;
1.228     djm      1241:        int i, r, fd, sock, exitval, num_env;
1.214     djm      1242:        Buffer m;
1.229     djm      1243:        char *term;
1.215     djm      1244:        extern char **environ;
1.229     djm      1245:        u_int  flags;
1.242     djm      1246:
                   1247:        if (mux_command == 0)
                   1248:                mux_command = SSHMUX_COMMAND_OPEN;
                   1249:
                   1250:        switch (options.control_master) {
                   1251:        case SSHCTL_MASTER_AUTO:
                   1252:        case SSHCTL_MASTER_AUTO_ASK:
                   1253:                debug("auto-mux: Trying existing master");
                   1254:                /* FALLTHROUGH */
                   1255:        case SSHCTL_MASTER_NO:
                   1256:                break;
                   1257:        default:
                   1258:                return;
                   1259:        }
1.228     djm      1260:
1.214     djm      1261:        memset(&addr, '\0', sizeof(addr));
                   1262:        addr.sun_family = AF_UNIX;
                   1263:        addr.sun_len = offsetof(struct sockaddr_un, sun_path) +
                   1264:            strlen(path) + 1;
                   1265:
                   1266:        if (strlcpy(addr.sun_path, path,
                   1267:            sizeof(addr.sun_path)) >= sizeof(addr.sun_path))
                   1268:                fatal("ControlPath too long");
                   1269:
                   1270:        if ((sock = socket(PF_UNIX, SOCK_STREAM, 0)) < 0)
                   1271:                fatal("%s socket(): %s", __func__, strerror(errno));
                   1272:
1.237     jakob    1273:        if (connect(sock, (struct sockaddr*)&addr, addr.sun_len) == -1) {
1.240     djm      1274:                if (mux_command != SSHMUX_COMMAND_OPEN) {
                   1275:                        fatal("Control socket connect(%.100s): %s", path,
                   1276:                            strerror(errno));
                   1277:                }
1.239     djm      1278:                if (errno == ENOENT)
                   1279:                        debug("Control socket \"%.100s\" does not exist", path);
                   1280:                else {
                   1281:                        error("Control socket connect(%.100s): %s", path,
                   1282:                            strerror(errno));
                   1283:                }
1.237     jakob    1284:                close(sock);
                   1285:                return;
                   1286:        }
1.248     djm      1287:
1.237     jakob    1288:        if (stdin_null_flag) {
                   1289:                if ((fd = open(_PATH_DEVNULL, O_RDONLY)) == -1)
                   1290:                        fatal("open(/dev/null): %s", strerror(errno));
                   1291:                if (dup2(fd, STDIN_FILENO) == -1)
                   1292:                        fatal("dup2: %s", strerror(errno));
                   1293:                if (fd > STDERR_FILENO)
                   1294:                        close(fd);
                   1295:        }
1.248     djm      1296:
1.247     djm      1297:        term = getenv("TERM");
1.229     djm      1298:
                   1299:        flags = 0;
                   1300:        if (tty_flag)
                   1301:                flags |= SSHMUX_FLAG_TTY;
                   1302:        if (subsystem_flag)
                   1303:                flags |= SSHMUX_FLAG_SUBSYS;
1.247     djm      1304:        if (options.forward_x11)
                   1305:                flags |= SSHMUX_FLAG_X11_FWD;
                   1306:        if (options.forward_agent)
                   1307:                flags |= SSHMUX_FLAG_AGENT_FWD;
1.214     djm      1308:
                   1309:        buffer_init(&m);
                   1310:
1.229     djm      1311:        /* Send our command to server */
                   1312:        buffer_put_int(&m, mux_command);
                   1313:        buffer_put_int(&m, flags);
1.247     djm      1314:        if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
1.229     djm      1315:                fatal("%s: msg_send", __func__);
                   1316:        buffer_clear(&m);
                   1317:
                   1318:        /* Get authorisation status and PID of controlee */
1.214     djm      1319:        if (ssh_msg_recv(sock, &m) == -1)
                   1320:                fatal("%s: msg_recv", __func__);
1.247     djm      1321:        if (buffer_get_char(&m) != SSHMUX_VER)
1.214     djm      1322:                fatal("%s: wrong version", __func__);
1.216     djm      1323:        if (buffer_get_int(&m) != 1)
                   1324:                fatal("Connection to master denied");
1.214     djm      1325:        control_server_pid = buffer_get_int(&m);
                   1326:
                   1327:        buffer_clear(&m);
                   1328:
1.229     djm      1329:        switch (mux_command) {
                   1330:        case SSHMUX_COMMAND_ALIVE_CHECK:
1.234     deraadt  1331:                fprintf(stderr, "Master running (pid=%d)\r\n",
1.229     djm      1332:                    control_server_pid);
                   1333:                exit(0);
                   1334:        case SSHMUX_COMMAND_TERMINATE:
                   1335:                fprintf(stderr, "Exit request sent.\r\n");
                   1336:                exit(0);
                   1337:        case SSHMUX_COMMAND_OPEN:
                   1338:                /* continue below */
                   1339:                break;
                   1340:        default:
                   1341:                fatal("silly mux_command %d", mux_command);
                   1342:        }
                   1343:
                   1344:        /* SSHMUX_COMMAND_OPEN */
1.247     djm      1345:        buffer_put_cstring(&m, term ? term : "");
1.214     djm      1346:        buffer_append(&command, "\0", 1);
                   1347:        buffer_put_cstring(&m, buffer_ptr(&command));
1.215     djm      1348:
1.220     djm      1349:        if (options.num_send_env == 0 || environ == NULL) {
                   1350:                buffer_put_int(&m, 0);
1.223     deraadt  1351:        } else {
1.220     djm      1352:                /* Pass environment */
                   1353:                num_env = 0;
                   1354:                for (i = 0; environ[i] != NULL; i++)
                   1355:                        if (env_permitted(environ[i]))
                   1356:                                num_env++; /* Count */
1.223     deraadt  1357:
1.220     djm      1358:                buffer_put_int(&m, num_env);
                   1359:
1.222     dtucker  1360:                for (i = 0; environ[i] != NULL && num_env >= 0; i++)
                   1361:                        if (env_permitted(environ[i])) {
                   1362:                                num_env--;
1.220     djm      1363:                                buffer_put_cstring(&m, environ[i]);
1.222     dtucker  1364:                        }
1.220     djm      1365:        }
1.214     djm      1366:
1.247     djm      1367:        if (ssh_msg_send(sock, SSHMUX_VER, &m) == -1)
1.214     djm      1368:                fatal("%s: msg_send", __func__);
                   1369:
                   1370:        mm_send_fd(sock, STDIN_FILENO);
                   1371:        mm_send_fd(sock, STDOUT_FILENO);
                   1372:        mm_send_fd(sock, STDERR_FILENO);
                   1373:
                   1374:        /* Wait for reply, so master has a chance to gather ttymodes */
                   1375:        buffer_clear(&m);
                   1376:        if (ssh_msg_recv(sock, &m) == -1)
                   1377:                fatal("%s: msg_recv", __func__);
1.247     djm      1378:        if (buffer_get_char(&m) != SSHMUX_VER)
1.229     djm      1379:                fatal("%s: wrong version", __func__);
1.214     djm      1380:        buffer_free(&m);
1.218     djm      1381:
1.226     djm      1382:        signal(SIGHUP, control_client_sighandler);
1.218     djm      1383:        signal(SIGINT, control_client_sighandler);
                   1384:        signal(SIGTERM, control_client_sighandler);
                   1385:        signal(SIGWINCH, control_client_sigrelay);
1.214     djm      1386:
                   1387:        if (tty_flag)
                   1388:                enter_raw_mode();
                   1389:
                   1390:        /* Stick around until the controlee closes the client_fd */
                   1391:        exitval = 0;
                   1392:        for (;!control_client_terminate;) {
                   1393:                r = read(sock, &exitval, sizeof(exitval));
                   1394:                if (r == 0) {
                   1395:                        debug2("Received EOF from master");
                   1396:                        break;
                   1397:                }
                   1398:                if (r > 0)
                   1399:                        debug2("Received exit status from master %d", exitval);
                   1400:                if (r == -1 && errno != EINTR)
                   1401:                        fatal("%s: read %s", __func__, strerror(errno));
                   1402:        }
                   1403:
                   1404:        if (control_client_terminate)
                   1405:                debug2("Exiting on signal %d", control_client_terminate);
                   1406:
                   1407:        close(sock);
                   1408:
                   1409:        leave_raw_mode();
                   1410:
                   1411:        if (tty_flag && options.log_level != SYSLOG_LEVEL_QUIET)
                   1412:                fprintf(stderr, "Connection to master closed.\r\n");
                   1413:
                   1414:        exit(exitval);
1.1       deraadt  1415: }