Annotation of src/usr.bin/ssh/sshd.c, Revision 1.600
1.600 ! guenther 1: /* $OpenBSD: sshd.c,v 1.599 2023/03/06 12:14:48 dtucker Exp $ */
1.86 markus 2: /*
1.65 deraadt 3: * Author: Tatu Ylonen <ylo@cs.hut.fi>
4: * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5: * All rights reserved
1.126 deraadt 6: * This program is the ssh daemon. It listens for connections from clients,
7: * and performs authentication, executes use commands or shell, and forwards
1.65 deraadt 8: * information to/from the application to the user client over an encrypted
1.126 deraadt 9: * connection. This can also handle forwarding of X11, TCP/IP, and
10: * authentication agent connections.
1.98 markus 11: *
1.126 deraadt 12: * As far as I am concerned, the code I have written for this software
13: * can be used freely for any purpose. Any derived versions of this
14: * software must be clearly marked as such, and if the derived work is
15: * incompatible with the protocol description in the RFC file, it must be
16: * called by a name other than "ssh" or "Secure Shell".
17: *
18: * SSH2 implementation:
1.231 provos 19: * Privilege Separation:
1.126 deraadt 20: *
1.231 provos 21: * Copyright (c) 2000, 2001, 2002 Markus Friedl. All rights reserved.
22: * Copyright (c) 2002 Niels Provos. All rights reserved.
1.126 deraadt 23: *
24: * Redistribution and use in source and binary forms, with or without
25: * modification, are permitted provided that the following conditions
26: * are met:
27: * 1. Redistributions of source code must retain the above copyright
28: * notice, this list of conditions and the following disclaimer.
29: * 2. Redistributions in binary form must reproduce the above copyright
30: * notice, this list of conditions and the following disclaimer in the
31: * documentation and/or other materials provided with the distribution.
32: *
33: * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
34: * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
35: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
36: * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
37: * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
38: * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
39: * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
40: * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
41: * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
42: * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
1.65 deraadt 43: */
1.1 deraadt 44:
1.343 deraadt 45: #include <sys/types.h>
1.320 stevesk 46: #include <sys/ioctl.h>
1.321 stevesk 47: #include <sys/wait.h>
1.343 deraadt 48: #include <sys/tree.h>
1.323 stevesk 49: #include <sys/stat.h>
1.334 stevesk 50: #include <sys/socket.h>
1.340 stevesk 51: #include <sys/time.h>
1.357 djm 52: #include <sys/queue.h>
1.319 stevesk 53:
1.336 stevesk 54: #include <errno.h>
1.335 stevesk 55: #include <fcntl.h>
1.338 stevesk 56: #include <netdb.h>
1.319 stevesk 57: #include <paths.h>
1.579 deraadt 58: #include <poll.h>
1.333 stevesk 59: #include <pwd.h>
1.322 stevesk 60: #include <signal.h>
1.342 stevesk 61: #include <stdio.h>
1.341 stevesk 62: #include <stdlib.h>
1.339 stevesk 63: #include <string.h>
1.541 naddy 64: #include <stdarg.h>
1.344 dtucker 65: #include <unistd.h>
1.438 deraadt 66: #include <limits.h>
1.1 deraadt 67:
1.426 markus 68: #ifdef WITH_OPENSSL
1.155 markus 69: #include <openssl/bn.h>
1.426 markus 70: #endif
1.155 markus 71:
1.343 deraadt 72: #include "xmalloc.h"
1.155 markus 73: #include "ssh.h"
74: #include "ssh2.h"
1.171 djm 75: #include "sshpty.h"
1.1 deraadt 76: #include "packet.h"
1.155 markus 77: #include "log.h"
1.511 markus 78: #include "sshbuf.h"
1.428 millert 79: #include "misc.h"
1.454 markus 80: #include "match.h"
1.1 deraadt 81: #include "servconf.h"
82: #include "uidswap.h"
1.33 markus 83: #include "compat.h"
1.155 markus 84: #include "cipher.h"
1.415 markus 85: #include "digest.h"
1.512 markus 86: #include "sshkey.h"
1.98 markus 87: #include "kex.h"
1.108 markus 88: #include "authfile.h"
1.154 markus 89: #include "pathnames.h"
1.155 markus 90: #include "atomicio.h"
91: #include "canohost.h"
1.343 deraadt 92: #include "hostfile.h"
1.155 markus 93: #include "auth.h"
1.404 markus 94: #include "authfd.h"
1.294 djm 95: #include "msg.h"
1.186 markus 96: #include "dispatch.h"
1.206 stevesk 97: #include "channels.h"
1.230 provos 98: #include "session.h"
1.231 provos 99: #include "monitor.h"
1.343 deraadt 100: #ifdef GSSAPI
101: #include "ssh-gss.h"
102: #endif
1.231 provos 103: #include "monitor_wrap.h"
1.385 djm 104: #include "ssh-sandbox.h"
1.506 djm 105: #include "auth-options.h"
1.332 stevesk 106: #include "version.h"
1.432 djm 107: #include "ssherr.h"
1.542 djm 108: #include "sk-api.h"
1.567 dtucker 109: #include "srclimit.h"
1.571 dtucker 110: #include "dh.h"
1.522 djm 111:
1.296 djm 112: /* Re-exec fds */
113: #define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1)
114: #define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2)
115: #define REEXEC_CONFIG_PASS_FD (STDERR_FILENO + 3)
116: #define REEXEC_MIN_FREE_FD (STDERR_FILENO + 4)
117:
1.138 markus 118: extern char *__progname;
119:
1.1 deraadt 120: /* Server configuration options. */
121: ServerOptions options;
122:
123: /* Name of the server configuration file. */
1.154 markus 124: char *config_file_name = _PATH_SERVER_CONFIG_FILE;
1.1 deraadt 125:
1.105 markus 126: /*
1.65 deraadt 127: * Debug mode flag. This can be set on the command line. If debug
128: * mode is enabled, extra debugging output will be sent to the system
129: * log, the daemon will not go to background, and will exit after processing
130: * the first connection.
131: */
1.1 deraadt 132: int debug_flag = 0;
133:
1.499 djm 134: /*
135: * Indicating that the daemon should only test the configuration and keys.
136: * If test_flag > 1 ("-T" flag), then sshd will also dump the effective
137: * configuration, optionally using connection information provided by the
138: * "-C" flag.
139: */
1.521 djm 140: static int test_flag = 0;
1.203 stevesk 141:
1.1 deraadt 142: /* Flag indicating that the daemon is being started from inetd. */
1.521 djm 143: static int inetd_flag = 0;
1.1 deraadt 144:
1.135 markus 145: /* Flag indicating that sshd should not detach and become a daemon. */
1.521 djm 146: static int no_daemon_flag = 0;
1.135 markus 147:
1.47 markus 148: /* debug goes to stderr unless inetd_flag is set */
1.521 djm 149: static int log_stderr = 0;
1.47 markus 150:
1.1 deraadt 151: /* Saved arguments to main(). */
1.521 djm 152: static char **saved_argv;
1.1 deraadt 153:
1.294 djm 154: /* re-exec */
1.521 djm 155: static int rexeced_flag = 0;
156: static int rexec_flag = 1;
157: static int rexec_argc = 0;
158: static char **rexec_argv;
1.294 djm 159:
1.66 markus 160: /*
1.75 markus 161: * The sockets that the server is listening; this is used in the SIGHUP
162: * signal handler.
1.66 markus 163: */
1.75 markus 164: #define MAX_LISTEN_SOCKS 16
1.521 djm 165: static int listen_socks[MAX_LISTEN_SOCKS];
166: static int num_listen_socks = 0;
1.1 deraadt 167:
1.404 markus 168: /* Daemon's agent connection */
1.432 djm 169: int auth_sock = -1;
1.521 djm 170: static int have_agent = 0;
1.404 markus 171:
1.66 markus 172: /*
173: * Any really sensitive data in the application is contained in this
174: * structure. The idea is that this structure could be locked into memory so
175: * that the pages do not get written into swap. However, there are some
176: * problems. The private key contains BIGNUMs, and we do not (in principle)
177: * have access to the internals of them, and locking just the structure is
178: * not very useful. Currently, memory locking is not implemented.
179: */
1.64 markus 180: struct {
1.488 markus 181: struct sshkey **host_keys; /* all private host keys */
182: struct sshkey **host_pubkeys; /* all public host keys */
183: struct sshkey **host_certificates; /* all public host certificates */
184: int have_ssh2_key;
1.1 deraadt 185: } sensitive_data;
186:
1.199 markus 187: /* This is set to true when a signal is received. */
1.212 markus 188: static volatile sig_atomic_t received_sighup = 0;
189: static volatile sig_atomic_t received_sigterm = 0;
1.1 deraadt 190:
1.125 markus 191: /* record remote hostname or ip */
1.438 deraadt 192: u_int utmp_len = HOST_NAME_MAX+1;
1.125 markus 193:
1.533 djm 194: /*
195: * startup_pipes/flags are used for tracking children of the listening sshd
196: * process early in their lifespans. This tracking is needed for three things:
197: *
198: * 1) Implementing the MaxStartups limit of concurrent unauthenticated
199: * connections.
200: * 2) Avoiding a race condition for SIGHUP processing, where child processes
201: * may have listen_socks open that could collide with main listener process
202: * after it restarts.
203: * 3) Ensuring that rexec'd sshd processes have received their initial state
204: * from the parent listen process before handling SIGHUP.
205: *
206: * Child processes signal that they have completed closure of the listen_socks
207: * and (if applicable) received their rexec state by sending a char over their
208: * sock. Child processes signal that authentication has completed by closing
209: * the sock (or by exiting).
210: */
1.521 djm 211: static int *startup_pipes = NULL;
1.533 djm 212: static int *startup_flags = NULL; /* Indicates child closed listener */
213: static int startup_pipe = -1; /* in child */
1.211 markus 214:
1.231 provos 215: /* variables used for privilege separation */
1.337 dtucker 216: int use_privsep = -1;
1.285 dtucker 217: struct monitor *pmonitor = NULL;
1.386 djm 218: int privsep_is_preauth = 1;
1.231 provos 219:
1.527 djm 220: /* global connection state and authentication contexts */
1.278 markus 221: Authctxt *the_authctxt = NULL;
1.527 djm 222: struct ssh *the_active_state;
1.278 markus 223:
1.506 djm 224: /* global key/cert auth options. XXX move to permanent ssh->authctxt? */
225: struct sshauthopt *auth_opts = NULL;
226:
1.337 dtucker 227: /* sshd_config buffer */
1.511 markus 228: struct sshbuf *cfg;
1.337 dtucker 229:
1.546 djm 230: /* Included files from the configuration file */
231: struct include_list includes = TAILQ_HEAD_INITIALIZER(includes);
232:
1.299 dtucker 233: /* message to be displayed after login */
1.510 markus 234: struct sshbuf *loginmsg;
1.299 dtucker 235:
1.1 deraadt 236: /* Prototypes for various functions defined later in this file. */
1.200 itojun 237: void destroy_sensitive_data(void);
1.231 provos 238: void demote_sensitive_data(void);
1.525 djm 239: static void do_ssh2_kex(struct ssh *);
1.129 provos 240:
1.545 djm 241: static char *listener_proctitle;
242:
1.87 markus 243: /*
1.75 markus 244: * Close all listening sockets
245: */
1.200 itojun 246: static void
1.75 markus 247: close_listen_socks(void)
248: {
249: int i;
1.250 deraadt 250:
1.75 markus 251: for (i = 0; i < num_listen_socks; i++)
252: close(listen_socks[i]);
1.580 djm 253: num_listen_socks = 0;
1.75 markus 254: }
255:
1.211 markus 256: static void
257: close_startup_pipes(void)
258: {
259: int i;
1.250 deraadt 260:
1.211 markus 261: if (startup_pipes)
262: for (i = 0; i < options.max_startups; i++)
263: if (startup_pipes[i] != -1)
264: close(startup_pipes[i]);
265: }
266:
1.75 markus 267: /*
1.65 deraadt 268: * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP;
269: * the effect is to reread the configuration file (and to regenerate
270: * the server key).
271: */
1.327 deraadt 272:
1.200 itojun 273: static void
1.64 markus 274: sighup_handler(int sig)
1.1 deraadt 275: {
1.64 markus 276: received_sighup = 1;
1.1 deraadt 277: }
278:
1.65 deraadt 279: /*
280: * Called from the main program after receiving SIGHUP.
281: * Restarts the server.
282: */
1.200 itojun 283: static void
1.165 itojun 284: sighup_restart(void)
1.1 deraadt 285: {
1.264 itojun 286: logit("Received SIGHUP; restarting.");
1.479 dtucker 287: if (options.pid_file != NULL)
288: unlink(options.pid_file);
1.75 markus 289: close_listen_socks();
1.211 markus 290: close_startup_pipes();
1.544 dtucker 291: ssh_signal(SIGHUP, SIG_IGN); /* will be restored after exec */
1.64 markus 292: execv(saved_argv[0], saved_argv);
1.264 itojun 293: logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0],
1.250 deraadt 294: strerror(errno));
1.64 markus 295: exit(1);
1.1 deraadt 296: }
297:
1.65 deraadt 298: /*
299: * Generic signal handler for terminating signals in the master daemon.
300: */
1.200 itojun 301: static void
1.64 markus 302: sigterm_handler(int sig)
1.1 deraadt 303: {
1.199 markus 304: received_sigterm = sig;
1.1 deraadt 305: }
306:
1.65 deraadt 307: /*
308: * SIGCHLD handler. This is called whenever a child dies. This will then
1.199 markus 309: * reap any zombies left by exited children.
1.65 deraadt 310: */
1.200 itojun 311: static void
1.64 markus 312: main_sigchld_handler(int sig)
1.1 deraadt 313: {
1.250 deraadt 314: int save_errno = errno;
1.239 markus 315: pid_t pid;
1.64 markus 316: int status;
1.544 dtucker 317:
1.239 markus 318: while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
1.537 deraadt 319: (pid == -1 && errno == EINTR))
1.64 markus 320: ;
321: errno = save_errno;
1.1 deraadt 322: }
323:
1.65 deraadt 324: /*
325: * Signal handler for the alarm after the login grace period has expired.
326: */
1.200 itojun 327: static void
1.64 markus 328: grace_alarm_handler(int sig)
1.1 deraadt 329: {
1.394 djm 330: /*
331: * Try to kill any processes that we have spawned, E.g. authorized
1.583 dtucker 332: * keys command helpers or privsep children.
1.394 djm 333: */
334: if (getpgid(0) == getpid()) {
1.544 dtucker 335: ssh_signal(SIGTERM, SIG_IGN);
1.416 djm 336: kill(0, SIGTERM);
1.394 djm 337: }
1.285 dtucker 338:
1.64 markus 339: /* Log error and exit. */
1.583 dtucker 340: sigdie("Timeout before authentication for %s port %d",
341: ssh_remote_ipaddr(the_active_state),
342: ssh_remote_port(the_active_state));
1.62 markus 343: }
344:
1.134 markus 345: /* Destroy the host and server keys. They will no longer be needed. */
1.108 markus 346: void
347: destroy_sensitive_data(void)
348: {
1.493 djm 349: u_int i;
1.134 markus 350:
1.217 deraadt 351: for (i = 0; i < options.num_host_key_files; i++) {
1.134 markus 352: if (sensitive_data.host_keys[i]) {
1.512 markus 353: sshkey_free(sensitive_data.host_keys[i]);
1.134 markus 354: sensitive_data.host_keys[i] = NULL;
355: }
1.373 djm 356: if (sensitive_data.host_certificates[i]) {
1.512 markus 357: sshkey_free(sensitive_data.host_certificates[i]);
1.373 djm 358: sensitive_data.host_certificates[i] = NULL;
359: }
1.134 markus 360: }
361: }
362:
1.231 provos 363: /* Demote private to public keys for network child */
364: void
365: demote_sensitive_data(void)
366: {
1.488 markus 367: struct sshkey *tmp;
1.493 djm 368: u_int i;
1.512 markus 369: int r;
1.231 provos 370:
371: for (i = 0; i < options.num_host_key_files; i++) {
372: if (sensitive_data.host_keys[i]) {
1.515 djm 373: if ((r = sshkey_from_private(
374: sensitive_data.host_keys[i], &tmp)) != 0)
1.564 djm 375: fatal_r(r, "could not demote host %s key",
376: sshkey_type(sensitive_data.host_keys[i]));
1.512 markus 377: sshkey_free(sensitive_data.host_keys[i]);
1.231 provos 378: sensitive_data.host_keys[i] = tmp;
379: }
1.373 djm 380: /* Certs do not need demotion */
1.231 provos 381: }
382: }
383:
1.233 markus 384: static void
1.231 provos 385: privsep_preauth_child(void)
386: {
1.253 deraadt 387: gid_t gidset[1];
1.250 deraadt 388: struct passwd *pw;
1.231 provos 389:
390: /* Enable challenge-response authentication for privilege separation */
391: privsep_challenge_enable();
1.419 djm 392:
1.420 markus 393: #ifdef GSSAPI
1.419 djm 394: /* Cache supported mechanism OIDs for later use */
1.516 djm 395: ssh_gssapi_prepare_supported_oids();
1.420 markus 396: #endif
1.231 provos 397:
398: /* Demote the private keys to public keys. */
399: demote_sensitive_data();
400:
1.460 djm 401: /* Demote the child */
402: if (getuid() == 0 || geteuid() == 0) {
403: if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
404: fatal("Privilege separation user %s does not exist",
405: SSH_PRIVSEP_USER);
1.500 djm 406: pw = pwcopy(pw); /* Ensure mutable */
1.460 djm 407: endpwent();
1.500 djm 408: freezero(pw->pw_passwd, strlen(pw->pw_passwd));
1.460 djm 409:
410: /* Change our root directory */
411: if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1)
412: fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR,
413: strerror(errno));
414: if (chdir("/") == -1)
415: fatal("chdir(\"/\"): %s", strerror(errno));
416:
417: /*
418: * Drop our privileges
419: * NB. Can't use setusercontext() after chroot.
420: */
421: debug3("privsep user:group %u:%u", (u_int)pw->pw_uid,
422: (u_int)pw->pw_gid);
423: gidset[0] = pw->pw_gid;
1.537 deraadt 424: if (setgroups(1, gidset) == -1)
1.460 djm 425: fatal("setgroups: %.100s", strerror(errno));
426: permanently_set_uid(pw);
427: }
1.231 provos 428: }
429:
1.278 markus 430: static int
1.525 djm 431: privsep_preauth(struct ssh *ssh)
1.237 markus 432: {
1.432 djm 433: int status, r;
1.237 markus 434: pid_t pid;
1.384 djm 435: struct ssh_sandbox *box = NULL;
1.237 markus 436:
437: /* Set up unprivileged child process to deal with network data */
1.242 mouring 438: pmonitor = monitor_init();
1.237 markus 439: /* Store a pointer to the kex for later rekeying */
1.525 djm 440: pmonitor->m_pkex = &ssh->kex;
1.237 markus 441:
1.393 djm 442: if (use_privsep == PRIVSEP_ON)
1.384 djm 443: box = ssh_sandbox_init();
1.237 markus 444: pid = fork();
445: if (pid == -1) {
446: fatal("fork of unprivileged child failed");
447: } else if (pid != 0) {
1.245 mpech 448: debug2("Network child is on pid %ld", (long)pid);
1.237 markus 449:
1.392 markus 450: pmonitor->m_pid = pid;
1.432 djm 451: if (have_agent) {
452: r = ssh_get_authentication_socket(&auth_sock);
453: if (r != 0) {
1.564 djm 454: error_r(r, "Could not get agent socket");
1.432 djm 455: have_agent = 0;
456: }
457: }
1.384 djm 458: if (box != NULL)
459: ssh_sandbox_parent_preauth(box, pid);
1.526 djm 460: monitor_child_preauth(ssh, pmonitor);
1.237 markus 461:
462: /* Wait for the child's exit status */
1.537 deraadt 463: while (waitpid(pid, &status, 0) == -1) {
1.386 djm 464: if (errno == EINTR)
465: continue;
466: pmonitor->m_pid = -1;
1.564 djm 467: fatal_f("waitpid: %s", strerror(errno));
1.384 djm 468: }
1.386 djm 469: privsep_is_preauth = 0;
470: pmonitor->m_pid = -1;
1.384 djm 471: if (WIFEXITED(status)) {
472: if (WEXITSTATUS(status) != 0)
1.564 djm 473: fatal_f("preauth child exited with status %d",
474: WEXITSTATUS(status));
1.384 djm 475: } else if (WIFSIGNALED(status))
1.564 djm 476: fatal_f("preauth child terminated by signal %d",
477: WTERMSIG(status));
1.384 djm 478: if (box != NULL)
479: ssh_sandbox_parent_finish(box);
480: return 1;
1.237 markus 481: } else {
482: /* child */
1.383 djm 483: close(pmonitor->m_sendfd);
484: close(pmonitor->m_log_recvfd);
1.237 markus 485:
1.383 djm 486: /* Arrange for logging to be sent to the monitor */
487: set_log_handler(mm_log_handler, pmonitor);
1.237 markus 488:
1.460 djm 489: privsep_preauth_child();
1.238 stevesk 490: setproctitle("%s", "[net]");
1.384 djm 491: if (box != NULL)
492: ssh_sandbox_child(box);
493:
494: return 0;
1.237 markus 495: }
496: }
497:
1.233 markus 498: static void
1.525 djm 499: privsep_postauth(struct ssh *ssh, Authctxt *authctxt)
1.231 provos 500: {
1.474 djm 501: if (authctxt->pw->pw_uid == 0) {
1.231 provos 502: /* File descriptor passing is broken or root login */
503: use_privsep = 0;
1.315 djm 504: goto skip;
1.231 provos 505: }
1.234 markus 506:
1.231 provos 507: /* New socket pair */
1.242 mouring 508: monitor_reinit(pmonitor);
1.231 provos 509:
1.242 mouring 510: pmonitor->m_pid = fork();
511: if (pmonitor->m_pid == -1)
1.231 provos 512: fatal("fork of unprivileged child failed");
1.242 mouring 513: else if (pmonitor->m_pid != 0) {
1.364 markus 514: verbose("User child is on pid %ld", (long)pmonitor->m_pid);
1.510 markus 515: sshbuf_reset(loginmsg);
1.526 djm 516: monitor_clear_keystate(ssh, pmonitor);
517: monitor_child_postauth(ssh, pmonitor);
1.231 provos 518:
519: /* NEVERREACHED */
520: exit(0);
521: }
522:
1.383 djm 523: /* child */
524:
1.242 mouring 525: close(pmonitor->m_sendfd);
1.383 djm 526: pmonitor->m_sendfd = -1;
1.231 provos 527:
528: /* Demote the private keys to public keys. */
529: demote_sensitive_data();
1.354 djm 530:
1.231 provos 531: /* Drop privileges */
532: do_setusercontext(authctxt->pw);
533:
1.315 djm 534: skip:
1.231 provos 535: /* It is safe now to apply the key state */
1.526 djm 536: monitor_apply_keystate(ssh, pmonitor);
1.312 markus 537:
538: /*
539: * Tell the packet layer that authentication was successful, since
540: * this information is not part of the key state.
541: */
1.525 djm 542: ssh_packet_set_authenticated(ssh);
1.231 provos 543: }
544:
1.509 djm 545: static void
546: append_hostkey_type(struct sshbuf *b, const char *s)
547: {
548: int r;
549:
550: if (match_pattern_list(s, options.hostkeyalgorithms, 0) != 1) {
1.564 djm 551: debug3_f("%s key not permitted by HostkeyAlgorithms", s);
1.509 djm 552: return;
553: }
554: if ((r = sshbuf_putf(b, "%s%s", sshbuf_len(b) > 0 ? "," : "", s)) != 0)
1.564 djm 555: fatal_fr(r, "sshbuf_putf");
1.509 djm 556: }
557:
1.200 itojun 558: static char *
1.134 markus 559: list_hostkey_types(void)
560: {
1.509 djm 561: struct sshbuf *b;
562: struct sshkey *key;
1.281 jakob 563: char *ret;
1.493 djm 564: u_int i;
1.223 markus 565:
1.509 djm 566: if ((b = sshbuf_new()) == NULL)
1.564 djm 567: fatal_f("sshbuf_new failed");
1.217 deraadt 568: for (i = 0; i < options.num_host_key_files; i++) {
1.373 djm 569: key = sensitive_data.host_keys[i];
1.443 djm 570: if (key == NULL)
1.404 markus 571: key = sensitive_data.host_pubkeys[i];
1.472 markus 572: if (key == NULL)
1.134 markus 573: continue;
1.214 deraadt 574: switch (key->type) {
1.134 markus 575: case KEY_RSA:
1.509 djm 576: /* for RSA we also support SHA2 signatures */
577: append_hostkey_type(b, "rsa-sha2-512");
578: append_hostkey_type(b, "rsa-sha2-256");
579: /* FALLTHROUGH */
1.134 markus 580: case KEY_DSA:
1.378 djm 581: case KEY_ECDSA:
1.412 markus 582: case KEY_ED25519:
1.542 djm 583: case KEY_ECDSA_SK:
584: case KEY_ED25519_SK:
1.505 markus 585: case KEY_XMSS:
1.509 djm 586: append_hostkey_type(b, sshkey_ssh_name(key));
1.134 markus 587: break;
588: }
1.373 djm 589: /* If the private key has a cert peer, then list that too */
590: key = sensitive_data.host_certificates[i];
591: if (key == NULL)
592: continue;
593: switch (key->type) {
594: case KEY_RSA_CERT:
1.509 djm 595: /* for RSA we also support SHA2 signatures */
596: append_hostkey_type(b,
597: "rsa-sha2-512-cert-v01@openssh.com");
598: append_hostkey_type(b,
599: "rsa-sha2-256-cert-v01@openssh.com");
600: /* FALLTHROUGH */
1.373 djm 601: case KEY_DSA_CERT:
1.378 djm 602: case KEY_ECDSA_CERT:
1.412 markus 603: case KEY_ED25519_CERT:
1.542 djm 604: case KEY_ECDSA_SK_CERT:
605: case KEY_ED25519_SK_CERT:
1.505 markus 606: case KEY_XMSS_CERT:
1.509 djm 607: append_hostkey_type(b, sshkey_ssh_name(key));
1.373 djm 608: break;
609: }
1.134 markus 610: }
1.509 djm 611: if ((ret = sshbuf_dup_string(b)) == NULL)
1.564 djm 612: fatal_f("sshbuf_dup_string failed");
1.509 djm 613: sshbuf_free(b);
1.564 djm 614: debug_f("%s", ret);
1.281 jakob 615: return ret;
1.134 markus 616: }
617:
1.488 markus 618: static struct sshkey *
1.440 djm 619: get_hostkey_by_type(int type, int nid, int need_private, struct ssh *ssh)
1.134 markus 620: {
1.493 djm 621: u_int i;
1.488 markus 622: struct sshkey *key;
1.250 deraadt 623:
1.217 deraadt 624: for (i = 0; i < options.num_host_key_files; i++) {
1.375 djm 625: switch (type) {
626: case KEY_RSA_CERT:
627: case KEY_DSA_CERT:
1.378 djm 628: case KEY_ECDSA_CERT:
1.412 markus 629: case KEY_ED25519_CERT:
1.542 djm 630: case KEY_ECDSA_SK_CERT:
631: case KEY_ED25519_SK_CERT:
1.505 markus 632: case KEY_XMSS_CERT:
1.373 djm 633: key = sensitive_data.host_certificates[i];
1.375 djm 634: break;
635: default:
1.373 djm 636: key = sensitive_data.host_keys[i];
1.404 markus 637: if (key == NULL && !need_private)
638: key = sensitive_data.host_pubkeys[i];
1.375 djm 639: break;
640: }
1.542 djm 641: if (key == NULL || key->type != type)
642: continue;
643: switch (type) {
644: case KEY_ECDSA:
645: case KEY_ECDSA_SK:
646: case KEY_ECDSA_CERT:
647: case KEY_ECDSA_SK_CERT:
648: if (key->ecdsa_nid != nid)
649: continue;
650: /* FALLTHROUGH */
651: default:
1.373 djm 652: return need_private ?
653: sensitive_data.host_keys[i] : key;
1.542 djm 654: }
1.134 markus 655: }
656: return NULL;
1.96 markus 657: }
658:
1.488 markus 659: struct sshkey *
1.440 djm 660: get_hostkey_public_by_type(int type, int nid, struct ssh *ssh)
1.373 djm 661: {
1.440 djm 662: return get_hostkey_by_type(type, nid, 0, ssh);
1.373 djm 663: }
664:
1.488 markus 665: struct sshkey *
1.440 djm 666: get_hostkey_private_by_type(int type, int nid, struct ssh *ssh)
1.373 djm 667: {
1.440 djm 668: return get_hostkey_by_type(type, nid, 1, ssh);
1.373 djm 669: }
670:
1.488 markus 671: struct sshkey *
1.231 provos 672: get_hostkey_by_index(int ind)
673: {
1.493 djm 674: if (ind < 0 || (u_int)ind >= options.num_host_key_files)
1.231 provos 675: return (NULL);
676: return (sensitive_data.host_keys[ind]);
677: }
678:
1.488 markus 679: struct sshkey *
1.435 markus 680: get_hostkey_public_by_index(int ind, struct ssh *ssh)
1.404 markus 681: {
1.493 djm 682: if (ind < 0 || (u_int)ind >= options.num_host_key_files)
1.404 markus 683: return (NULL);
684: return (sensitive_data.host_pubkeys[ind]);
685: }
686:
1.231 provos 687: int
1.488 markus 688: get_hostkey_index(struct sshkey *key, int compare, struct ssh *ssh)
1.231 provos 689: {
1.493 djm 690: u_int i;
1.250 deraadt 691:
1.231 provos 692: for (i = 0; i < options.num_host_key_files; i++) {
1.512 markus 693: if (sshkey_is_cert(key)) {
1.442 djm 694: if (key == sensitive_data.host_certificates[i] ||
695: (compare && sensitive_data.host_certificates[i] &&
696: sshkey_equal(key,
697: sensitive_data.host_certificates[i])))
1.373 djm 698: return (i);
699: } else {
1.442 djm 700: if (key == sensitive_data.host_keys[i] ||
701: (compare && sensitive_data.host_keys[i] &&
702: sshkey_equal(key, sensitive_data.host_keys[i])))
1.373 djm 703: return (i);
1.442 djm 704: if (key == sensitive_data.host_pubkeys[i] ||
705: (compare && sensitive_data.host_pubkeys[i] &&
706: sshkey_equal(key, sensitive_data.host_pubkeys[i])))
1.404 markus 707: return (i);
1.373 djm 708: }
1.231 provos 709: }
710: return (-1);
711: }
712:
1.439 djm 713: /* Inform the client of all hostkeys */
714: static void
715: notify_hostkeys(struct ssh *ssh)
716: {
717: struct sshbuf *buf;
718: struct sshkey *key;
1.493 djm 719: u_int i, nkeys;
720: int r;
1.439 djm 721: char *fp;
1.446 dtucker 722:
723: /* Some clients cannot cope with the hostkeys message, skip those. */
1.527 djm 724: if (ssh->compat & SSH_BUG_HOSTKEYS)
1.446 dtucker 725: return;
1.439 djm 726:
727: if ((buf = sshbuf_new()) == NULL)
1.564 djm 728: fatal_f("sshbuf_new");
1.439 djm 729: for (i = nkeys = 0; i < options.num_host_key_files; i++) {
730: key = get_hostkey_public_by_index(i, ssh);
731: if (key == NULL || key->type == KEY_UNSPEC ||
1.472 markus 732: sshkey_is_cert(key))
1.439 djm 733: continue;
734: fp = sshkey_fingerprint(key, options.fingerprint_hash,
735: SSH_FP_DEFAULT);
1.564 djm 736: debug3_f("key %d: %s %s", i, sshkey_ssh_name(key), fp);
1.439 djm 737: free(fp);
1.442 djm 738: if (nkeys == 0) {
1.525 djm 739: /*
740: * Start building the request when we find the
741: * first usable key.
742: */
743: if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
744: (r = sshpkt_put_cstring(ssh, "hostkeys-00@openssh.com")) != 0 ||
745: (r = sshpkt_put_u8(ssh, 0)) != 0) /* want reply */
746: sshpkt_fatal(ssh, r, "%s: start request", __func__);
1.442 djm 747: }
1.525 djm 748: /* Append the key to the request */
1.442 djm 749: sshbuf_reset(buf);
750: if ((r = sshkey_putb(key, buf)) != 0)
1.564 djm 751: fatal_fr(r, "couldn't put hostkey %d", i);
1.525 djm 752: if ((r = sshpkt_put_stringb(ssh, buf)) != 0)
753: sshpkt_fatal(ssh, r, "%s: append key", __func__);
1.439 djm 754: nkeys++;
755: }
1.564 djm 756: debug3_f("sent %u hostkeys", nkeys);
1.439 djm 757: if (nkeys == 0)
1.564 djm 758: fatal_f("no hostkeys");
1.525 djm 759: if ((r = sshpkt_send(ssh)) != 0)
760: sshpkt_fatal(ssh, r, "%s: send", __func__);
1.442 djm 761: sshbuf_free(buf);
1.439 djm 762: }
763:
1.124 markus 764: /*
765: * returns 1 if connection should be dropped, 0 otherwise.
766: * dropping starts at connection #max_startups_begin with a probability
767: * of (max_startups_rate/100). the probability increases linearly until
768: * all connections are dropped for startups > max_startups
769: */
1.200 itojun 770: static int
1.555 djm 771: should_drop_connection(int startups)
1.124 markus 772: {
1.303 mickey 773: int p, r;
1.124 markus 774:
775: if (startups < options.max_startups_begin)
776: return 0;
777: if (startups >= options.max_startups)
778: return 1;
779: if (options.max_startups_rate == 100)
780: return 1;
781:
782: p = 100 - options.max_startups_rate;
783: p *= startups - options.max_startups_begin;
1.303 mickey 784: p /= options.max_startups - options.max_startups_begin;
1.124 markus 785: p += options.max_startups_rate;
1.356 djm 786: r = arc4random_uniform(100);
1.124 markus 787:
1.564 djm 788: debug_f("p %d, r %d", p, r);
1.124 markus 789: return (r < p) ? 1 : 0;
790: }
791:
1.555 djm 792: /*
793: * Check whether connection should be accepted by MaxStartups.
794: * Returns 0 if the connection is accepted. If the connection is refused,
795: * returns 1 and attempts to send notification to client.
796: * Logs when the MaxStartups condition is entered or exited, and periodically
797: * while in that state.
798: */
799: static int
1.567 dtucker 800: drop_connection(int sock, int startups, int notify_pipe)
1.555 djm 801: {
802: char *laddr, *raddr;
803: const char msg[] = "Exceeded MaxStartups\r\n";
804: static time_t last_drop, first_drop;
805: static u_int ndropped;
806: LogLevel drop_level = SYSLOG_LEVEL_VERBOSE;
807: time_t now;
808:
809: now = monotime();
1.567 dtucker 810: if (!should_drop_connection(startups) &&
811: srclimit_check_allow(sock, notify_pipe) == 1) {
1.555 djm 812: if (last_drop != 0 &&
813: startups < options.max_startups_begin - 1) {
814: /* XXX maybe need better hysteresis here */
815: logit("exited MaxStartups throttling after %s, "
816: "%u connections dropped",
817: fmt_timeframe(now - first_drop), ndropped);
818: last_drop = 0;
819: }
820: return 0;
821: }
822:
823: #define SSHD_MAXSTARTUPS_LOG_INTERVAL (5 * 60)
824: if (last_drop == 0) {
825: error("beginning MaxStartups throttling");
826: drop_level = SYSLOG_LEVEL_INFO;
827: first_drop = now;
828: ndropped = 0;
829: } else if (last_drop + SSHD_MAXSTARTUPS_LOG_INTERVAL < now) {
830: /* Periodic logs */
831: error("in MaxStartups throttling for %s, "
832: "%u connections dropped",
833: fmt_timeframe(now - first_drop), ndropped + 1);
834: drop_level = SYSLOG_LEVEL_INFO;
835: }
836: last_drop = now;
837: ndropped++;
838:
839: laddr = get_local_ipaddr(sock);
840: raddr = get_peer_ipaddr(sock);
841: do_log2(drop_level, "drop connection #%d from [%s]:%d on [%s]:%d "
842: "past MaxStartups", startups, raddr, get_peer_port(sock),
843: laddr, get_local_port(sock));
844: free(laddr);
845: free(raddr);
846: /* best-effort notification to client */
847: (void)write(sock, msg, sizeof(msg) - 1);
848: return 1;
849: }
850:
1.215 markus 851: static void
852: usage(void)
853: {
1.565 dtucker 854: fprintf(stderr, "%s, %s\n", SSH_VERSION, SSH_OPENSSL_VERSION);
1.289 markus 855: fprintf(stderr,
1.597 djm 856: "usage: sshd [-46DdeGiqTtV] [-C connection_spec] [-c host_cert_file]\n"
1.399 dtucker 857: " [-E log_file] [-f config_file] [-g login_grace_time]\n"
1.473 naddy 858: " [-h host_key_file] [-o option] [-p port] [-u len]\n"
1.289 markus 859: );
1.215 markus 860: exit(1);
861: }
862:
1.294 djm 863: static void
1.467 djm 864: send_rexec_state(int fd, struct sshbuf *conf)
1.294 djm 865: {
1.546 djm 866: struct sshbuf *m = NULL, *inc = NULL;
867: struct include_item *item = NULL;
1.467 djm 868: int r;
1.294 djm 869:
1.564 djm 870: debug3_f("entering fd = %d config len %zu", fd,
1.467 djm 871: sshbuf_len(conf));
1.294 djm 872:
1.546 djm 873: if ((m = sshbuf_new()) == NULL || (inc = sshbuf_new()) == NULL)
1.564 djm 874: fatal_f("sshbuf_new failed");
1.546 djm 875:
876: /* pack includes into a string */
877: TAILQ_FOREACH(item, &includes, entry) {
878: if ((r = sshbuf_put_cstring(inc, item->selector)) != 0 ||
879: (r = sshbuf_put_cstring(inc, item->filename)) != 0 ||
1.547 djm 880: (r = sshbuf_put_stringb(inc, item->contents)) != 0)
1.564 djm 881: fatal_fr(r, "compose includes");
1.546 djm 882: }
883:
1.294 djm 884: /*
885: * Protocol from reexec master to child:
886: * string configuration
1.546 djm 887: * string included_files[] {
888: * string selector
889: * string filename
890: * string contents
891: * }
1.294 djm 892: */
1.546 djm 893: if ((r = sshbuf_put_stringb(m, conf)) != 0 ||
894: (r = sshbuf_put_stringb(m, inc)) != 0)
1.564 djm 895: fatal_fr(r, "compose config");
1.467 djm 896: if (ssh_msg_send(fd, 0, m) == -1)
1.564 djm 897: error_f("ssh_msg_send failed");
1.294 djm 898:
1.467 djm 899: sshbuf_free(m);
1.546 djm 900: sshbuf_free(inc);
1.294 djm 901:
1.564 djm 902: debug3_f("done");
1.294 djm 903: }
904:
905: static void
1.511 markus 906: recv_rexec_state(int fd, struct sshbuf *conf)
1.294 djm 907: {
1.546 djm 908: struct sshbuf *m, *inc;
1.511 markus 909: u_char *cp, ver;
910: size_t len;
911: int r;
1.546 djm 912: struct include_item *item;
1.294 djm 913:
1.564 djm 914: debug3_f("entering fd = %d", fd);
1.294 djm 915:
1.546 djm 916: if ((m = sshbuf_new()) == NULL || (inc = sshbuf_new()) == NULL)
1.564 djm 917: fatal_f("sshbuf_new failed");
1.511 markus 918: if (ssh_msg_recv(fd, m) == -1)
1.564 djm 919: fatal_f("ssh_msg_recv failed");
1.511 markus 920: if ((r = sshbuf_get_u8(m, &ver)) != 0)
1.564 djm 921: fatal_fr(r, "parse version");
1.511 markus 922: if (ver != 0)
1.564 djm 923: fatal_f("rexec version mismatch");
1.546 djm 924: if ((r = sshbuf_get_string(m, &cp, &len)) != 0 ||
925: (r = sshbuf_get_stringb(m, inc)) != 0)
1.564 djm 926: fatal_fr(r, "parse config");
1.546 djm 927:
1.511 markus 928: if (conf != NULL && (r = sshbuf_put(conf, cp, len)))
1.564 djm 929: fatal_fr(r, "sshbuf_put");
1.294 djm 930:
1.546 djm 931: while (sshbuf_len(inc) != 0) {
932: item = xcalloc(1, sizeof(*item));
933: if ((item->contents = sshbuf_new()) == NULL)
1.564 djm 934: fatal_f("sshbuf_new failed");
1.546 djm 935: if ((r = sshbuf_get_cstring(inc, &item->selector, NULL)) != 0 ||
936: (r = sshbuf_get_cstring(inc, &item->filename, NULL)) != 0 ||
937: (r = sshbuf_get_stringb(inc, item->contents)) != 0)
1.564 djm 938: fatal_fr(r, "parse includes");
1.546 djm 939: TAILQ_INSERT_TAIL(&includes, item, entry);
940: }
941:
1.402 djm 942: free(cp);
1.511 markus 943: sshbuf_free(m);
1.294 djm 944:
1.564 djm 945: debug3_f("done");
1.294 djm 946: }
947:
1.345 djm 948: /* Accept a connection from inetd */
949: static void
950: server_accept_inetd(int *sock_in, int *sock_out)
951: {
952: if (rexeced_flag) {
953: close(REEXEC_CONFIG_PASS_FD);
954: *sock_in = *sock_out = dup(STDIN_FILENO);
955: } else {
956: *sock_in = dup(STDIN_FILENO);
957: *sock_out = dup(STDOUT_FILENO);
958: }
959: /*
960: * We intentionally do not close the descriptors 0, 1, and 2
961: * as our code for setting the descriptors won't work if
962: * ttyfd happens to be one of those.
963: */
1.562 djm 964: if (stdfd_devnull(1, 1, !log_stderr) == -1)
1.564 djm 965: error_f("stdfd_devnull failed");
1.345 djm 966: debug("inetd sockets after dupping: %d, %d", *sock_in, *sock_out);
967: }
968:
969: /*
970: * Listen for TCP connections
971: */
972: static void
1.494 djm 973: listen_on_addrs(struct listenaddr *la)
1.345 djm 974: {
1.494 djm 975: int ret, listen_sock;
1.345 djm 976: struct addrinfo *ai;
977: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
978:
1.494 djm 979: for (ai = la->addrs; ai; ai = ai->ai_next) {
1.345 djm 980: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
981: continue;
982: if (num_listen_socks >= MAX_LISTEN_SOCKS)
983: fatal("Too many listen sockets. "
984: "Enlarge MAX_LISTEN_SOCKS");
985: if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen,
986: ntop, sizeof(ntop), strport, sizeof(strport),
987: NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
988: error("getnameinfo failed: %.100s",
1.352 dtucker 989: ssh_gai_strerror(ret));
1.345 djm 990: continue;
991: }
992: /* Create socket for listening. */
1.370 dtucker 993: listen_sock = socket(ai->ai_family, ai->ai_socktype,
994: ai->ai_protocol);
1.537 deraadt 995: if (listen_sock == -1) {
1.345 djm 996: /* kernel may not support ipv6 */
997: verbose("socket: %.100s", strerror(errno));
998: continue;
999: }
1000: if (set_nonblock(listen_sock) == -1) {
1.483 djm 1001: close(listen_sock);
1002: continue;
1003: }
1004: if (fcntl(listen_sock, F_SETFD, FD_CLOEXEC) == -1) {
1005: verbose("socket: CLOEXEC: %s", strerror(errno));
1.345 djm 1006: close(listen_sock);
1007: continue;
1008: }
1.494 djm 1009: /* Socket options */
1010: set_reuseaddr(listen_sock);
1011: if (la->rdomain != NULL &&
1012: set_rdomain(listen_sock, la->rdomain) == -1) {
1013: close(listen_sock);
1014: continue;
1015: }
1.345 djm 1016:
1017: debug("Bind to port %s on %s.", strport, ntop);
1018:
1019: /* Bind the socket to the desired port. */
1.537 deraadt 1020: if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) == -1) {
1.345 djm 1021: error("Bind to port %s on %s failed: %.200s.",
1022: strport, ntop, strerror(errno));
1023: close(listen_sock);
1024: continue;
1025: }
1026: listen_socks[num_listen_socks] = listen_sock;
1027: num_listen_socks++;
1028:
1029: /* Start listening on the port. */
1.537 deraadt 1030: if (listen(listen_sock, SSH_LISTEN_BACKLOG) == -1)
1.345 djm 1031: fatal("listen on [%s]:%s: %.100s",
1032: ntop, strport, strerror(errno));
1.494 djm 1033: logit("Server listening on %s port %s%s%s.",
1034: ntop, strport,
1035: la->rdomain == NULL ? "" : " rdomain ",
1036: la->rdomain == NULL ? "" : la->rdomain);
1.345 djm 1037: }
1.494 djm 1038: }
1039:
1040: static void
1041: server_listen(void)
1042: {
1043: u_int i;
1044:
1.567 dtucker 1045: /* Initialise per-source limit tracking. */
1046: srclimit_init(options.max_startups, options.per_source_max_startups,
1047: options.per_source_masklen_ipv4, options.per_source_masklen_ipv6);
1048:
1.494 djm 1049: for (i = 0; i < options.num_listen_addrs; i++) {
1050: listen_on_addrs(&options.listen_addrs[i]);
1051: freeaddrinfo(options.listen_addrs[i].addrs);
1052: free(options.listen_addrs[i].rdomain);
1053: memset(&options.listen_addrs[i], 0,
1054: sizeof(options.listen_addrs[i]));
1055: }
1056: free(options.listen_addrs);
1057: options.listen_addrs = NULL;
1058: options.num_listen_addrs = 0;
1.345 djm 1059:
1060: if (!num_listen_socks)
1061: fatal("Cannot bind any address.");
1062: }
1063:
1064: /*
1065: * The main TCP accept loop. Note that, for the non-debug case, returns
1066: * from this function are in a forked subprocess.
1067: */
1068: static void
1069: server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
1070: {
1.579 deraadt 1071: struct pollfd *pfd = NULL;
1.584 djm 1072: int i, j, ret, npfd;
1.543 djm 1073: int ostartups = -1, startups = 0, listening = 0, lameduck = 0;
1.584 djm 1074: int startup_p[2] = { -1 , -1 }, *startup_pollfd;
1.533 djm 1075: char c = 0;
1.345 djm 1076: struct sockaddr_storage from;
1077: socklen_t fromlen;
1078: pid_t pid;
1.574 dtucker 1079: sigset_t nsigset, osigset;
1.345 djm 1080:
1081: /* setup fd set for accept */
1.550 djm 1082: /* pipes connected to unauthenticated child sshd processes */
1.345 djm 1083: startup_pipes = xcalloc(options.max_startups, sizeof(int));
1.533 djm 1084: startup_flags = xcalloc(options.max_startups, sizeof(int));
1.584 djm 1085: startup_pollfd = xcalloc(options.max_startups, sizeof(int));
1.345 djm 1086: for (i = 0; i < options.max_startups; i++)
1087: startup_pipes[i] = -1;
1088:
1089: /*
1.574 dtucker 1090: * Prepare signal mask that we use to block signals that might set
1091: * received_sigterm or received_sighup, so that we are guaranteed
1.579 deraadt 1092: * to immediately wake up the ppoll if a signal is received after
1.574 dtucker 1093: * the flag is checked.
1094: */
1095: sigemptyset(&nsigset);
1096: sigaddset(&nsigset, SIGHUP);
1097: sigaddset(&nsigset, SIGCHLD);
1098: sigaddset(&nsigset, SIGTERM);
1099: sigaddset(&nsigset, SIGQUIT);
1100:
1.584 djm 1101: /* sized for worst-case */
1.579 deraadt 1102: pfd = xcalloc(num_listen_socks + options.max_startups,
1103: sizeof(struct pollfd));
1104:
1.574 dtucker 1105: /*
1.345 djm 1106: * Stay listening for connections until the system crashes or
1107: * the daemon is killed with a signal.
1108: */
1109: for (;;) {
1.574 dtucker 1110: sigprocmask(SIG_BLOCK, &nsigset, &osigset);
1111: if (received_sigterm) {
1112: logit("Received signal %d; terminating.",
1113: (int) received_sigterm);
1114: close_listen_socks();
1115: if (options.pid_file != NULL)
1116: unlink(options.pid_file);
1117: exit(received_sigterm == SIGTERM ? 0 : 255);
1118: }
1.543 djm 1119: if (ostartups != startups) {
1.545 djm 1120: setproctitle("%s [listener] %d of %d-%d startups",
1121: listener_proctitle, startups,
1122: options.max_startups_begin, options.max_startups);
1.543 djm 1123: ostartups = startups;
1124: }
1.533 djm 1125: if (received_sighup) {
1126: if (!lameduck) {
1127: debug("Received SIGHUP; waiting for children");
1128: close_listen_socks();
1129: lameduck = 1;
1130: }
1.574 dtucker 1131: if (listening <= 0) {
1132: sigprocmask(SIG_SETMASK, &osigset, NULL);
1.533 djm 1133: sighup_restart();
1.574 dtucker 1134: }
1.533 djm 1135: }
1.345 djm 1136:
1.579 deraadt 1137: for (i = 0; i < num_listen_socks; i++) {
1138: pfd[i].fd = listen_socks[i];
1139: pfd[i].events = POLLIN;
1140: }
1.584 djm 1141: npfd = num_listen_socks;
1.579 deraadt 1142: for (i = 0; i < options.max_startups; i++) {
1.584 djm 1143: startup_pollfd[i] = -1;
1144: if (startup_pipes[i] != -1) {
1145: pfd[npfd].fd = startup_pipes[i];
1146: pfd[npfd].events = POLLIN;
1147: startup_pollfd[i] = npfd++;
1148: }
1.579 deraadt 1149: }
1.345 djm 1150:
1.574 dtucker 1151: /* Wait until a connection arrives or a child exits. */
1.584 djm 1152: ret = ppoll(pfd, npfd, NULL, &osigset);
1153: if (ret == -1 && errno != EINTR) {
1.579 deraadt 1154: error("ppoll: %.100s", strerror(errno));
1.584 djm 1155: if (errno == EINVAL)
1156: cleanup_exit(1); /* can't recover */
1157: }
1.574 dtucker 1158: sigprocmask(SIG_SETMASK, &osigset, NULL);
1.576 dtucker 1159: if (ret == -1)
1.345 djm 1160: continue;
1161:
1.533 djm 1162: for (i = 0; i < options.max_startups; i++) {
1163: if (startup_pipes[i] == -1 ||
1.584 djm 1164: startup_pollfd[i] == -1 ||
1165: !(pfd[startup_pollfd[i]].revents & (POLLIN|POLLHUP)))
1.533 djm 1166: continue;
1167: switch (read(startup_pipes[i], &c, sizeof(c))) {
1168: case -1:
1169: if (errno == EINTR || errno == EAGAIN)
1170: continue;
1171: if (errno != EPIPE) {
1.564 djm 1172: error_f("startup pipe %d (fd=%d): "
1173: "read %s", i, startup_pipes[i],
1174: strerror(errno));
1.533 djm 1175: }
1176: /* FALLTHROUGH */
1177: case 0:
1178: /* child exited or completed auth */
1.345 djm 1179: close(startup_pipes[i]);
1.567 dtucker 1180: srclimit_done(startup_pipes[i]);
1.345 djm 1181: startup_pipes[i] = -1;
1182: startups--;
1.533 djm 1183: if (startup_flags[i])
1184: listening--;
1185: break;
1186: case 1:
1187: /* child has finished preliminaries */
1188: if (startup_flags[i]) {
1189: listening--;
1190: startup_flags[i] = 0;
1191: }
1192: break;
1.345 djm 1193: }
1.533 djm 1194: }
1.345 djm 1195: for (i = 0; i < num_listen_socks; i++) {
1.579 deraadt 1196: if (!(pfd[i].revents & POLLIN))
1.345 djm 1197: continue;
1198: fromlen = sizeof(from);
1199: *newsock = accept(listen_socks[i],
1200: (struct sockaddr *)&from, &fromlen);
1.537 deraadt 1201: if (*newsock == -1) {
1.398 markus 1202: if (errno != EINTR && errno != EWOULDBLOCK &&
1203: errno != ECONNABORTED)
1.389 djm 1204: error("accept: %.100s",
1205: strerror(errno));
1206: if (errno == EMFILE || errno == ENFILE)
1207: usleep(100 * 1000);
1.345 djm 1208: continue;
1209: }
1.586 dtucker 1210: if (unset_nonblock(*newsock) == -1) {
1211: close(*newsock);
1212: continue;
1213: }
1214: if (pipe(startup_p) == -1) {
1215: error_f("pipe(startup_p): %s", strerror(errno));
1.582 djm 1216: close(*newsock);
1.567 dtucker 1217: continue;
1.582 djm 1218: }
1.567 dtucker 1219: if (drop_connection(*newsock, startups, startup_p[0])) {
1.345 djm 1220: close(*newsock);
1.567 dtucker 1221: close(startup_p[0]);
1222: close(startup_p[1]);
1.345 djm 1223: continue;
1224: }
1225:
1226: if (rexec_flag && socketpair(AF_UNIX,
1227: SOCK_STREAM, 0, config_s) == -1) {
1228: error("reexec socketpair: %s",
1229: strerror(errno));
1230: close(*newsock);
1231: close(startup_p[0]);
1232: close(startup_p[1]);
1233: continue;
1234: }
1235:
1236: for (j = 0; j < options.max_startups; j++)
1237: if (startup_pipes[j] == -1) {
1238: startup_pipes[j] = startup_p[0];
1239: startups++;
1.533 djm 1240: startup_flags[j] = 1;
1.345 djm 1241: break;
1242: }
1243:
1244: /*
1245: * Got connection. Fork a child to handle it, unless
1246: * we are in debugging mode.
1247: */
1248: if (debug_flag) {
1249: /*
1250: * In debugging mode. Close the listening
1251: * socket, and start processing the
1252: * connection without forking.
1253: */
1254: debug("Server will not fork when running in debugging mode.");
1255: close_listen_socks();
1256: *sock_in = *newsock;
1257: *sock_out = *newsock;
1258: close(startup_p[0]);
1259: close(startup_p[1]);
1260: startup_pipe = -1;
1261: pid = getpid();
1262: if (rexec_flag) {
1.511 markus 1263: send_rexec_state(config_s[0], cfg);
1.345 djm 1264: close(config_s[0]);
1265: }
1.579 deraadt 1266: free(pfd);
1.533 djm 1267: return;
1.345 djm 1268: }
1269:
1270: /*
1271: * Normal production daemon. Fork, and have
1272: * the child process the connection. The
1273: * parent continues listening.
1274: */
1.533 djm 1275: listening++;
1.345 djm 1276: if ((pid = fork()) == 0) {
1277: /*
1278: * Child. Close the listening and
1279: * max_startup sockets. Start using
1280: * the accepted socket. Reinitialize
1281: * logging (since our pid has changed).
1.533 djm 1282: * We return from this function to handle
1.345 djm 1283: * the connection.
1284: */
1285: startup_pipe = startup_p[1];
1286: close_startup_pipes();
1287: close_listen_socks();
1288: *sock_in = *newsock;
1289: *sock_out = *newsock;
1290: log_init(__progname,
1291: options.log_level,
1292: options.log_facility,
1293: log_stderr);
1294: if (rexec_flag)
1295: close(config_s[0]);
1.533 djm 1296: else {
1297: /*
1298: * Signal parent that the preliminaries
1299: * for this child are complete. For the
1300: * re-exec case, this happens after the
1301: * child has received the rexec state
1302: * from the server.
1303: */
1304: (void)atomicio(vwrite, startup_pipe,
1305: "\0", 1);
1306: }
1.579 deraadt 1307: free(pfd);
1.533 djm 1308: return;
1.345 djm 1309: }
1310:
1311: /* Parent. Stay in the loop. */
1.537 deraadt 1312: if (pid == -1)
1.345 djm 1313: error("fork: %.100s", strerror(errno));
1314: else
1315: debug("Forked child %ld.", (long)pid);
1316:
1317: close(startup_p[1]);
1318:
1319: if (rexec_flag) {
1.554 markus 1320: close(config_s[1]);
1.511 markus 1321: send_rexec_state(config_s[0], cfg);
1.345 djm 1322: close(config_s[0]);
1323: }
1324: close(*newsock);
1325: }
1326: }
1327: }
1328:
1.466 djm 1329: /*
1330: * If IP options are supported, make sure there are none (log and
1331: * return an error if any are found). Basically we are worried about
1332: * source routing; it can be used to pretend you are somebody
1333: * (ip-address) you are not. That itself may be "almost acceptable"
1.507 djm 1334: * under certain circumstances, but rhosts authentication is useless
1.466 djm 1335: * if source routing is accepted. Notice also that if we just dropped
1336: * source routing here, the other side could use IP spoofing to do
1337: * rest of the interaction and could still bypass security. So we
1338: * exit here if we detect any IP options.
1339: */
1340: static void
1341: check_ip_options(struct ssh *ssh)
1342: {
1343: int sock_in = ssh_packet_get_connection_in(ssh);
1344: struct sockaddr_storage from;
1345: u_char opts[200];
1.475 djm 1346: socklen_t i, option_size = sizeof(opts), fromlen = sizeof(from);
1.466 djm 1347: char text[sizeof(opts) * 3 + 1];
1348:
1349: memset(&from, 0, sizeof(from));
1350: if (getpeername(sock_in, (struct sockaddr *)&from,
1.537 deraadt 1351: &fromlen) == -1)
1.466 djm 1352: return;
1353: if (from.ss_family != AF_INET)
1354: return;
1355: /* XXX IPv6 options? */
1356:
1357: if (getsockopt(sock_in, IPPROTO_IP, IP_OPTIONS, opts,
1358: &option_size) >= 0 && option_size != 0) {
1359: text[0] = '\0';
1360: for (i = 0; i < option_size; i++)
1361: snprintf(text + i*3, sizeof(text) - i*3,
1362: " %2.2x", opts[i]);
1363: fatal("Connection from %.100s port %d with IP opts: %.800s",
1364: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), text);
1365: }
1366: return;
1367: }
1.345 djm 1368:
1.495 djm 1369: /* Set the routing domain for this process */
1370: static void
1371: set_process_rdomain(struct ssh *ssh, const char *name)
1372: {
1373: int rtable, ortable = getrtable();
1374: const char *errstr;
1375:
1376: if (name == NULL)
1377: return; /* default */
1378:
1379: if (strcmp(name, "%D") == 0) {
1380: /* "expands" to routing domain of connection */
1381: if ((name = ssh_packet_rdomain_in(ssh)) == NULL)
1382: return;
1383: }
1384:
1385: rtable = (int)strtonum(name, 0, 255, &errstr);
1386: if (errstr != NULL) /* Shouldn't happen */
1387: fatal("Invalid routing domain \"%s\": %s", name, errstr);
1388: if (rtable != ortable && setrtable(rtable) != 0)
1389: fatal("Unable to set routing domain %d: %s",
1390: rtable, strerror(errno));
1.564 djm 1391: debug_f("set routing domain %d (was %d)", rtable, ortable);
1.495 djm 1392: }
1393:
1.508 dtucker 1394: static void
1395: accumulate_host_timing_secret(struct sshbuf *server_cfg,
1.536 djm 1396: struct sshkey *key)
1.508 dtucker 1397: {
1398: static struct ssh_digest_ctx *ctx;
1399: u_char *hash;
1400: size_t len;
1401: struct sshbuf *buf;
1402: int r;
1403:
1404: if (ctx == NULL && (ctx = ssh_digest_start(SSH_DIGEST_SHA512)) == NULL)
1.564 djm 1405: fatal_f("ssh_digest_start");
1.508 dtucker 1406: if (key == NULL) { /* finalize */
1407: /* add server config in case we are using agent for host keys */
1408: if (ssh_digest_update(ctx, sshbuf_ptr(server_cfg),
1409: sshbuf_len(server_cfg)) != 0)
1.564 djm 1410: fatal_f("ssh_digest_update");
1.508 dtucker 1411: len = ssh_digest_bytes(SSH_DIGEST_SHA512);
1412: hash = xmalloc(len);
1413: if (ssh_digest_final(ctx, hash, len) != 0)
1.564 djm 1414: fatal_f("ssh_digest_final");
1.508 dtucker 1415: options.timing_secret = PEEK_U64(hash);
1416: freezero(hash, len);
1417: ssh_digest_free(ctx);
1418: ctx = NULL;
1419: return;
1420: }
1421: if ((buf = sshbuf_new()) == NULL)
1.564 djm 1422: fatal_f("could not allocate buffer");
1.508 dtucker 1423: if ((r = sshkey_private_serialize(key, buf)) != 0)
1.592 djm 1424: fatal_fr(r, "encode %s key", sshkey_ssh_name(key));
1.508 dtucker 1425: if (ssh_digest_update(ctx, sshbuf_ptr(buf), sshbuf_len(buf)) != 0)
1.564 djm 1426: fatal_f("ssh_digest_update");
1.508 dtucker 1427: sshbuf_reset(buf);
1428: sshbuf_free(buf);
1429: }
1430:
1.545 djm 1431: static char *
1432: prepare_proctitle(int ac, char **av)
1433: {
1434: char *ret = NULL;
1435: int i;
1436:
1437: for (i = 0; i < ac; i++)
1438: xextendf(&ret, " ", "%s", av[i]);
1439: return ret;
1440: }
1441:
1.597 djm 1442: static void
1443: print_config(struct ssh *ssh, struct connection_info *connection_info)
1444: {
1445: /*
1446: * If no connection info was provided by -C then use
1447: * use a blank one that will cause no predicate to match.
1448: */
1449: if (connection_info == NULL)
1450: connection_info = get_connection_info(ssh, 0, 0);
1451: connection_info->test = 1;
1452: parse_server_match_config(&options, &includes, connection_info);
1453: dump_config(&options);
1454: exit(0);
1455: }
1456:
1.65 deraadt 1457: /*
1458: * Main program for the daemon.
1459: */
1.2 provos 1460: int
1461: main(int ac, char **av)
1.1 deraadt 1462: {
1.466 djm 1463: struct ssh *ssh = NULL;
1.64 markus 1464: extern char *optarg;
1465: extern int optind;
1.597 djm 1466: int r, opt, on = 1, do_dump_cfg = 0, already_daemon, remote_port;
1.297 avsm 1467: int sock_in = -1, sock_out = -1, newsock = -1;
1.496 djm 1468: const char *remote_ip, *rdomain;
1.447 dtucker 1469: char *fp, *line, *laddr, *logfile = NULL;
1.345 djm 1470: int config_s[2] = { -1 , -1 };
1.493 djm 1471: u_int i, j;
1.364 markus 1472: u_int64_t ibytes, obytes;
1.362 dtucker 1473: mode_t new_umask;
1.488 markus 1474: struct sshkey *key;
1475: struct sshkey *pubkey;
1.404 markus 1476: int keytype;
1.230 provos 1477: Authctxt *authctxt;
1.498 dtucker 1478: struct connection_info *connection_info = NULL;
1.594 djm 1479: sigset_t sigmask;
1480:
1481: sigemptyset(&sigmask);
1482: sigprocmask(SIG_SETMASK, &sigmask, NULL);
1.64 markus 1483:
1.138 markus 1484: /* Save argv. */
1.64 markus 1485: saved_argv = av;
1.294 djm 1486: rexec_argc = ac;
1.313 djm 1487:
1488: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1489: sanitise_stdfd();
1.64 markus 1490:
1491: /* Initialize configuration options to their default values. */
1492: initialize_server_options(&options);
1493:
1494: /* Parse command-line arguments. */
1.450 djm 1495: while ((opt = getopt(ac, av,
1.597 djm 1496: "C:E:b:c:f:g:h:k:o:p:u:46DGQRTdeiqrtV")) != -1) {
1.64 markus 1497: switch (opt) {
1.75 markus 1498: case '4':
1.305 djm 1499: options.address_family = AF_INET;
1.75 markus 1500: break;
1501: case '6':
1.305 djm 1502: options.address_family = AF_INET6;
1.75 markus 1503: break;
1.64 markus 1504: case 'f':
1505: config_file_name = optarg;
1506: break;
1.373 djm 1507: case 'c':
1.493 djm 1508: servconf_add_hostcert("[command-line]", 0,
1509: &options, optarg);
1.373 djm 1510: break;
1.64 markus 1511: case 'd':
1.273 markus 1512: if (debug_flag == 0) {
1.127 markus 1513: debug_flag = 1;
1514: options.log_level = SYSLOG_LEVEL_DEBUG1;
1.273 markus 1515: } else if (options.log_level < SYSLOG_LEVEL_DEBUG3)
1.127 markus 1516: options.log_level++;
1.64 markus 1517: break;
1.135 markus 1518: case 'D':
1519: no_daemon_flag = 1;
1.192 lebel 1520: break;
1.597 djm 1521: case 'G':
1522: do_dump_cfg = 1;
1523: break;
1.399 dtucker 1524: case 'E':
1.459 dtucker 1525: logfile = optarg;
1.399 dtucker 1526: /* FALLTHROUGH */
1.192 lebel 1527: case 'e':
1528: log_stderr = 1;
1.135 markus 1529: break;
1.64 markus 1530: case 'i':
1531: inetd_flag = 1;
1532: break;
1.294 djm 1533: case 'r':
1534: rexec_flag = 0;
1535: break;
1536: case 'R':
1537: rexeced_flag = 1;
1538: inetd_flag = 1;
1539: break;
1.64 markus 1540: case 'Q':
1.158 markus 1541: /* ignored */
1.64 markus 1542: break;
1543: case 'q':
1544: options.log_level = SYSLOG_LEVEL_QUIET;
1545: break;
1546: case 'b':
1.473 naddy 1547: /* protocol 1, ignored */
1.64 markus 1548: break;
1549: case 'p':
1.75 markus 1550: options.ports_from_cmdline = 1;
1.127 markus 1551: if (options.num_ports >= MAX_PORTS) {
1552: fprintf(stderr, "too many ports.\n");
1553: exit(1);
1554: }
1.193 stevesk 1555: options.ports[options.num_ports++] = a2port(optarg);
1.366 djm 1556: if (options.ports[options.num_ports-1] <= 0) {
1.193 stevesk 1557: fprintf(stderr, "Bad port number.\n");
1558: exit(1);
1559: }
1.64 markus 1560: break;
1561: case 'g':
1.197 stevesk 1562: if ((options.login_grace_time = convtime(optarg)) == -1) {
1563: fprintf(stderr, "Invalid login grace time.\n");
1564: exit(1);
1565: }
1.64 markus 1566: break;
1567: case 'k':
1.473 naddy 1568: /* protocol 1, ignored */
1.64 markus 1569: break;
1570: case 'h':
1.493 djm 1571: servconf_add_hostkey("[command-line]", 0,
1.519 djm 1572: &options, optarg, 1);
1.64 markus 1573: break;
1.203 stevesk 1574: case 't':
1575: test_flag = 1;
1576: break;
1.358 dtucker 1577: case 'T':
1578: test_flag = 2;
1579: break;
1580: case 'C':
1.523 djm 1581: connection_info = get_connection_info(ssh, 0, 0);
1.391 dtucker 1582: if (parse_server_match_testspec(connection_info,
1583: optarg) == -1)
1584: exit(1);
1.358 dtucker 1585: break;
1.125 markus 1586: case 'u':
1.438 deraadt 1587: utmp_len = (u_int)strtonum(optarg, 0, HOST_NAME_MAX+1+1, NULL);
1588: if (utmp_len > HOST_NAME_MAX+1) {
1.257 stevesk 1589: fprintf(stderr, "Invalid utmp length.\n");
1590: exit(1);
1591: }
1.125 markus 1592: break;
1.215 markus 1593: case 'o':
1.283 markus 1594: line = xstrdup(optarg);
1595: if (process_server_config_line(&options, line,
1.546 djm 1596: "command-line", 0, NULL, NULL, &includes) != 0)
1.217 deraadt 1597: exit(1);
1.402 djm 1598: free(line);
1.215 markus 1599: break;
1.596 millert 1600: case 'V':
1601: fprintf(stderr, "%s, %s\n",
1602: SSH_VERSION, SSH_OPENSSL_VERSION);
1603: exit(0);
1.64 markus 1604: default:
1.215 markus 1605: usage();
1606: break;
1.64 markus 1607: }
1608: }
1.294 djm 1609: if (rexeced_flag || inetd_flag)
1610: rexec_flag = 0;
1.597 djm 1611: if (!test_flag && !do_dump_cfg && rexec_flag && !path_absolute(av[0]))
1.294 djm 1612: fatal("sshd re-exec requires execution with an absolute path");
1613: if (rexeced_flag)
1.296 djm 1614: closefrom(REEXEC_MIN_FREE_FD);
1615: else
1616: closefrom(REEXEC_DEVCRYPTO_RESERVED_FD);
1.294 djm 1617:
1.426 markus 1618: #ifdef WITH_OPENSSL
1.379 djm 1619: OpenSSL_add_all_algorithms();
1.426 markus 1620: #endif
1.64 markus 1621:
1.399 dtucker 1622: /* If requested, redirect the logs to the specified logfile. */
1.459 dtucker 1623: if (logfile != NULL)
1.399 dtucker 1624: log_redirect_stderr_to(logfile);
1.75 markus 1625: /*
1626: * Force logging to stderr until we have loaded the private host
1627: * key (unless started from inetd)
1628: */
1.138 markus 1629: log_init(__progname,
1.224 markus 1630: options.log_level == SYSLOG_LEVEL_NOT_SET ?
1631: SYSLOG_LEVEL_INFO : options.log_level,
1632: options.log_facility == SYSLOG_FACILITY_NOT_SET ?
1633: SYSLOG_FACILITY_AUTH : options.log_facility,
1.548 djm 1634: log_stderr || !inetd_flag || debug_flag);
1.75 markus 1635:
1.294 djm 1636: sensitive_data.have_ssh2_key = 0;
1637:
1.358 dtucker 1638: /*
1.498 dtucker 1639: * If we're not doing an extended test do not silently ignore connection
1640: * test params.
1.358 dtucker 1641: */
1.498 dtucker 1642: if (test_flag < 2 && connection_info != NULL)
1.358 dtucker 1643: fatal("Config test connection parameter (-C) provided without "
1.572 djm 1644: "test mode (-T)");
1.358 dtucker 1645:
1.294 djm 1646: /* Fetch our configuration */
1.511 markus 1647: if ((cfg = sshbuf_new()) == NULL)
1.564 djm 1648: fatal_f("sshbuf_new failed");
1.533 djm 1649: if (rexeced_flag) {
1.560 markus 1650: setproctitle("%s", "[rexeced]");
1.511 markus 1651: recv_rexec_state(REEXEC_CONFIG_PASS_FD, cfg);
1.533 djm 1652: if (!debug_flag) {
1653: startup_pipe = dup(REEXEC_STARTUP_PIPE_FD);
1654: close(REEXEC_STARTUP_PIPE_FD);
1655: /*
1656: * Signal parent that this child is at a point where
1657: * they can go away if they have a SIGHUP pending.
1658: */
1659: (void)atomicio(vwrite, startup_pipe, "\0", 1);
1660: }
1.549 djm 1661: } else if (strcasecmp(config_file_name, "none") != 0)
1.511 markus 1662: load_server_config(config_file_name, cfg);
1.294 djm 1663:
1.337 dtucker 1664: parse_server_config(&options, rexeced_flag ? "rexec" : config_file_name,
1.585 djm 1665: cfg, &includes, NULL, rexeced_flag);
1.571 dtucker 1666:
1.578 dtucker 1667: #ifdef WITH_OPENSSL
1.571 dtucker 1668: if (options.moduli_file != NULL)
1669: dh_set_moduli_file(options.moduli_file);
1.578 dtucker 1670: #endif
1.64 markus 1671:
1672: /* Fill in default values for those options not explicitly set. */
1673: fill_default_server_options(&options);
1.395 djm 1674:
1675: /* Check that options are sensible */
1676: if (options.authorized_keys_command_user == NULL &&
1677: (options.authorized_keys_command != NULL &&
1678: strcasecmp(options.authorized_keys_command, "none") != 0))
1679: fatal("AuthorizedKeysCommand set without "
1680: "AuthorizedKeysCommandUser");
1.449 djm 1681: if (options.authorized_principals_command_user == NULL &&
1682: (options.authorized_principals_command != NULL &&
1683: strcasecmp(options.authorized_principals_command, "none") != 0))
1684: fatal("AuthorizedPrincipalsCommand set without "
1685: "AuthorizedPrincipalsCommandUser");
1.396 djm 1686:
1687: /*
1688: * Check whether there is any path through configured auth methods.
1689: * Unfortunately it is not possible to verify this generally before
1690: * daemonisation in the presence of Match block, but this catches
1691: * and warns for trivial misconfigurations that could break login.
1692: */
1693: if (options.num_auth_methods != 0) {
1.493 djm 1694: for (i = 0; i < options.num_auth_methods; i++) {
1695: if (auth2_methods_valid(options.auth_methods[i],
1.396 djm 1696: 1) == 0)
1697: break;
1698: }
1.493 djm 1699: if (i >= options.num_auth_methods)
1.396 djm 1700: fatal("AuthenticationMethods cannot be satisfied by "
1701: "enabled authentication methods");
1702: }
1.305 djm 1703:
1.64 markus 1704: /* Check that there are no remaining arguments. */
1705: if (optind < ac) {
1706: fprintf(stderr, "Extra argument %s.\n", av[optind]);
1707: exit(1);
1708: }
1709:
1.565 dtucker 1710: debug("sshd version %s, %s", SSH_VERSION, SSH_OPENSSL_VERSION);
1.64 markus 1711:
1.597 djm 1712: if (do_dump_cfg)
1713: print_config(ssh, connection_info);
1714:
1.404 markus 1715: /* load host keys */
1.329 djm 1716: sensitive_data.host_keys = xcalloc(options.num_host_key_files,
1.488 markus 1717: sizeof(struct sshkey *));
1.404 markus 1718: sensitive_data.host_pubkeys = xcalloc(options.num_host_key_files,
1.488 markus 1719: sizeof(struct sshkey *));
1.404 markus 1720:
1721: if (options.host_key_agent) {
1722: if (strcmp(options.host_key_agent, SSH_AUTHSOCKET_ENV_NAME))
1723: setenv(SSH_AUTHSOCKET_ENV_NAME,
1724: options.host_key_agent, 1);
1.433 djm 1725: if ((r = ssh_get_authentication_socket(NULL)) == 0)
1726: have_agent = 1;
1727: else
1.564 djm 1728: error_r(r, "Could not connect to agent \"%s\"",
1729: options.host_key_agent);
1.404 markus 1730: }
1.134 markus 1731:
1.217 deraadt 1732: for (i = 0; i < options.num_host_key_files; i++) {
1.519 djm 1733: int ll = options.host_key_file_userprovided[i] ?
1734: SYSLOG_LEVEL_ERROR : SYSLOG_LEVEL_DEBUG1;
1735:
1.430 djm 1736: if (options.host_key_files[i] == NULL)
1737: continue;
1.512 markus 1738: if ((r = sshkey_load_private(options.host_key_files[i], "",
1739: &key, NULL)) != 0 && r != SSH_ERR_SYSTEM_ERROR)
1.564 djm 1740: do_log2_r(r, ll, "Unable to load host key \"%s\"",
1741: options.host_key_files[i]);
1.542 djm 1742: if (sshkey_is_sk(key) &&
1743: key->sk_flags & SSH_SK_USER_PRESENCE_REQD) {
1744: debug("host key %s requires user presence, ignoring",
1745: options.host_key_files[i]);
1746: key->sk_flags &= ~SSH_SK_USER_PRESENCE_REQD;
1747: }
1748: if (r == 0 && key != NULL &&
1749: (r = sshkey_shield_private(key)) != 0) {
1.564 djm 1750: do_log2_r(r, ll, "Unable to shield host key \"%s\"",
1751: options.host_key_files[i]);
1.536 djm 1752: sshkey_free(key);
1753: key = NULL;
1754: }
1.512 markus 1755: if ((r = sshkey_load_public(options.host_key_files[i],
1756: &pubkey, NULL)) != 0 && r != SSH_ERR_SYSTEM_ERROR)
1.564 djm 1757: do_log2_r(r, ll, "Unable to load host key \"%s\"",
1758: options.host_key_files[i]);
1.557 djm 1759: if (pubkey != NULL && key != NULL) {
1760: if (!sshkey_equal(pubkey, key)) {
1761: error("Public key for %s does not match "
1762: "private key", options.host_key_files[i]);
1763: sshkey_free(pubkey);
1764: pubkey = NULL;
1765: }
1766: }
1767: if (pubkey == NULL && key != NULL) {
1.515 djm 1768: if ((r = sshkey_from_private(key, &pubkey)) != 0)
1.564 djm 1769: fatal_r(r, "Could not demote key: \"%s\"",
1770: options.host_key_files[i]);
1.591 djm 1771: }
1772: if (pubkey != NULL && (r = sshkey_check_rsa_length(pubkey,
1773: options.required_rsa_size)) != 0) {
1774: error_fr(r, "Host key %s", options.host_key_files[i]);
1775: sshkey_free(pubkey);
1776: sshkey_free(key);
1777: continue;
1.557 djm 1778: }
1.179 markus 1779: sensitive_data.host_keys[i] = key;
1.404 markus 1780: sensitive_data.host_pubkeys[i] = pubkey;
1781:
1.472 markus 1782: if (key == NULL && pubkey != NULL && have_agent) {
1.443 djm 1783: debug("will rely on agent for hostkey %s",
1784: options.host_key_files[i]);
1.404 markus 1785: keytype = pubkey->type;
1786: } else if (key != NULL) {
1787: keytype = key->type;
1.511 markus 1788: accumulate_host_timing_secret(cfg, key);
1.404 markus 1789: } else {
1.519 djm 1790: do_log2(ll, "Unable to load host key: %s",
1.195 markus 1791: options.host_key_files[i]);
1.179 markus 1792: sensitive_data.host_keys[i] = NULL;
1.404 markus 1793: sensitive_data.host_pubkeys[i] = NULL;
1.134 markus 1794: continue;
1795: }
1.404 markus 1796:
1797: switch (keytype) {
1.134 markus 1798: case KEY_RSA:
1799: case KEY_DSA:
1.378 djm 1800: case KEY_ECDSA:
1.412 markus 1801: case KEY_ED25519:
1.542 djm 1802: case KEY_ECDSA_SK:
1803: case KEY_ED25519_SK:
1.505 markus 1804: case KEY_XMSS:
1.441 djm 1805: if (have_agent || key != NULL)
1806: sensitive_data.have_ssh2_key = 1;
1.134 markus 1807: break;
1808: }
1.441 djm 1809: if ((fp = sshkey_fingerprint(pubkey, options.fingerprint_hash,
1810: SSH_FP_DEFAULT)) == NULL)
1811: fatal("sshkey_fingerprint failed");
1812: debug("%s host key #%d: %s %s",
1.472 markus 1813: key ? "private" : "agent", i, sshkey_ssh_name(pubkey), fp);
1.441 djm 1814: free(fp);
1.134 markus 1815: }
1.511 markus 1816: accumulate_host_timing_secret(cfg, NULL);
1.472 markus 1817: if (!sensitive_data.have_ssh2_key) {
1.264 itojun 1818: logit("sshd: no hostkeys available -- exiting.");
1.64 markus 1819: exit(1);
1820: }
1821:
1.373 djm 1822: /*
1823: * Load certificates. They are stored in an array at identical
1824: * indices to the public keys that they relate to.
1825: */
1826: sensitive_data.host_certificates = xcalloc(options.num_host_key_files,
1.488 markus 1827: sizeof(struct sshkey *));
1.373 djm 1828: for (i = 0; i < options.num_host_key_files; i++)
1829: sensitive_data.host_certificates[i] = NULL;
1830:
1831: for (i = 0; i < options.num_host_cert_files; i++) {
1.430 djm 1832: if (options.host_cert_files[i] == NULL)
1833: continue;
1.512 markus 1834: if ((r = sshkey_load_public(options.host_cert_files[i],
1835: &key, NULL)) != 0) {
1.564 djm 1836: error_r(r, "Could not load host certificate \"%s\"",
1837: options.host_cert_files[i]);
1.373 djm 1838: continue;
1839: }
1.512 markus 1840: if (!sshkey_is_cert(key)) {
1.373 djm 1841: error("Certificate file is not a certificate: %s",
1842: options.host_cert_files[i]);
1.512 markus 1843: sshkey_free(key);
1.373 djm 1844: continue;
1845: }
1846: /* Find matching private key */
1847: for (j = 0; j < options.num_host_key_files; j++) {
1.512 markus 1848: if (sshkey_equal_public(key,
1.575 djm 1849: sensitive_data.host_pubkeys[j])) {
1.373 djm 1850: sensitive_data.host_certificates[j] = key;
1851: break;
1852: }
1853: }
1854: if (j >= options.num_host_key_files) {
1855: error("No matching private key for certificate: %s",
1856: options.host_cert_files[i]);
1.512 markus 1857: sshkey_free(key);
1.373 djm 1858: continue;
1859: }
1860: sensitive_data.host_certificates[j] = key;
1.493 djm 1861: debug("host certificate: #%u type %d %s", j, key->type,
1.512 markus 1862: sshkey_type(key));
1.373 djm 1863: }
1.426 markus 1864:
1.244 markus 1865: if (use_privsep) {
1866: struct stat st;
1867:
1.327 deraadt 1868: if (getpwnam(SSH_PRIVSEP_USER) == NULL)
1.244 markus 1869: fatal("Privilege separation user %s does not exist",
1870: SSH_PRIVSEP_USER);
1.500 djm 1871: endpwent();
1.244 markus 1872: if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) ||
1873: (S_ISDIR(st.st_mode) == 0))
1874: fatal("Missing privilege separation directory: %s",
1.247 stevesk 1875: _PATH_PRIVSEP_CHROOT_DIR);
1876: if (st.st_uid != 0 || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)
1.262 markus 1877: fatal("%s must be owned by root and not group or "
1878: "world-writable.", _PATH_PRIVSEP_CHROOT_DIR);
1.358 dtucker 1879: }
1880:
1.597 djm 1881: if (test_flag > 1)
1882: print_config(ssh, connection_info);
1.203 stevesk 1883:
1884: /* Configuration looks good, so exit if in test mode. */
1885: if (test_flag)
1886: exit(0);
1.108 markus 1887:
1.294 djm 1888: if (rexec_flag) {
1.493 djm 1889: if (rexec_argc < 0)
1890: fatal("rexec_argc %d < 0", rexec_argc);
1.329 djm 1891: rexec_argv = xcalloc(rexec_argc + 2, sizeof(char *));
1.493 djm 1892: for (i = 0; i < (u_int)rexec_argc; i++) {
1.294 djm 1893: debug("rexec_argv[%d]='%s'", i, saved_argv[i]);
1894: rexec_argv[i] = saved_argv[i];
1895: }
1896: rexec_argv[rexec_argc] = "-R";
1897: rexec_argv[rexec_argc + 1] = NULL;
1898: }
1.545 djm 1899: listener_proctitle = prepare_proctitle(ac, av);
1.362 dtucker 1900:
1901: /* Ensure that umask disallows at least group and world write */
1902: new_umask = umask(0077) | 0022;
1903: (void) umask(new_umask);
1.294 djm 1904:
1.108 markus 1905: /* Initialize the log (it is reinitialized below in case we forked). */
1.306 dtucker 1906: if (debug_flag && (!inetd_flag || rexeced_flag))
1.64 markus 1907: log_stderr = 1;
1.563 djm 1908: log_init(__progname, options.log_level,
1909: options.log_facility, log_stderr);
1910: for (i = 0; i < options.num_log_verbose; i++)
1911: log_verbose_add(options.log_verbose[i]);
1.64 markus 1912:
1.108 markus 1913: /*
1.478 dtucker 1914: * If not in debugging mode, not started from inetd and not already
1915: * daemonized (eg re-exec via SIGHUP), disconnect from the controlling
1916: * terminal, and fork. The original process exits.
1.108 markus 1917: */
1.478 dtucker 1918: already_daemon = daemonized();
1919: if (!(debug_flag || inetd_flag || no_daemon_flag || already_daemon)) {
1.345 djm 1920:
1.537 deraadt 1921: if (daemon(0, 0) == -1)
1.64 markus 1922: fatal("daemon() failed: %.200s", strerror(errno));
1923:
1.477 dtucker 1924: disconnect_controlling_tty();
1.64 markus 1925: }
1926: /* Reinitialize the log (because of the fork above). */
1.138 markus 1927: log_init(__progname, options.log_level, options.log_facility, log_stderr);
1.64 markus 1928:
1.572 djm 1929: /*
1930: * Chdir to the root directory so that the current disk can be
1931: * unmounted if desired.
1932: */
1.401 dtucker 1933: if (chdir("/") == -1)
1934: error("chdir(\"/\"): %s", strerror(errno));
1.217 deraadt 1935:
1.178 markus 1936: /* ignore SIGPIPE */
1.544 dtucker 1937: ssh_signal(SIGPIPE, SIG_IGN);
1.64 markus 1938:
1.345 djm 1939: /* Get a connection, either from inetd or a listening TCP socket */
1.64 markus 1940: if (inetd_flag) {
1.345 djm 1941: server_accept_inetd(&sock_in, &sock_out);
1.64 markus 1942: } else {
1.345 djm 1943: server_listen();
1.75 markus 1944:
1.544 dtucker 1945: ssh_signal(SIGHUP, sighup_handler);
1946: ssh_signal(SIGCHLD, main_sigchld_handler);
1947: ssh_signal(SIGTERM, sigterm_handler);
1948: ssh_signal(SIGQUIT, sigterm_handler);
1.201 markus 1949:
1.345 djm 1950: /*
1951: * Write out the pid file after the sigterm handler
1952: * is setup and the listen sockets are bound
1953: */
1.479 dtucker 1954: if (options.pid_file != NULL && !debug_flag) {
1.345 djm 1955: FILE *f = fopen(options.pid_file, "w");
1.201 markus 1956:
1.270 djm 1957: if (f == NULL) {
1958: error("Couldn't create pid file \"%s\": %s",
1959: options.pid_file, strerror(errno));
1960: } else {
1.245 mpech 1961: fprintf(f, "%ld\n", (long) getpid());
1.64 markus 1962: fclose(f);
1963: }
1964: }
1965:
1.345 djm 1966: /* Accept a connection and return in a forked child */
1967: server_accept_loop(&sock_in, &sock_out,
1968: &newsock, config_s);
1.1 deraadt 1969: }
1970:
1.64 markus 1971: /* This is the child processing a new connection. */
1.288 markus 1972: setproctitle("%s", "[accepted]");
1.294 djm 1973:
1.300 markus 1974: /*
1975: * Create a new session and process group since the 4.4BSD
1976: * setlogin() affects the entire process group. We don't
1977: * want the child to be able to affect the parent.
1978: */
1.537 deraadt 1979: if (!debug_flag && !inetd_flag && setsid() == -1)
1.300 markus 1980: error("setsid: %.100s", strerror(errno));
1981:
1.294 djm 1982: if (rexec_flag) {
1.296 djm 1983: debug("rexec start in %d out %d newsock %d pipe %d sock %d",
1984: sock_in, sock_out, newsock, startup_pipe, config_s[0]);
1.598 dtucker 1985: if (dup2(newsock, STDIN_FILENO) == -1)
1986: debug3_f("dup2 stdin: %s", strerror(errno));
1987: if (dup2(STDIN_FILENO, STDOUT_FILENO) == -1)
1988: debug3_f("dup2 stdout: %s", strerror(errno));
1.294 djm 1989: if (startup_pipe == -1)
1.296 djm 1990: close(REEXEC_STARTUP_PIPE_FD);
1.407 djm 1991: else if (startup_pipe != REEXEC_STARTUP_PIPE_FD) {
1.598 dtucker 1992: if (dup2(startup_pipe, REEXEC_STARTUP_PIPE_FD) == -1)
1993: debug3_f("dup2 startup_p: %s", strerror(errno));
1.407 djm 1994: close(startup_pipe);
1995: startup_pipe = REEXEC_STARTUP_PIPE_FD;
1996: }
1.294 djm 1997:
1.598 dtucker 1998: if (dup2(config_s[1], REEXEC_CONFIG_PASS_FD) == -1)
1999: debug3_f("dup2 config_s: %s", strerror(errno));
1.294 djm 2000: close(config_s[1]);
1.296 djm 2001:
1.559 markus 2002: ssh_signal(SIGHUP, SIG_IGN); /* avoid reset to SIG_DFL */
1.294 djm 2003: execv(rexec_argv[0], rexec_argv);
2004:
2005: /* Reexec has failed, fall back and continue */
2006: error("rexec of %s failed: %s", rexec_argv[0], strerror(errno));
1.296 djm 2007: recv_rexec_state(REEXEC_CONFIG_PASS_FD, NULL);
1.294 djm 2008: log_init(__progname, options.log_level,
2009: options.log_facility, log_stderr);
2010:
2011: /* Clean up fds */
1.296 djm 2012: close(REEXEC_CONFIG_PASS_FD);
2013: newsock = sock_out = sock_in = dup(STDIN_FILENO);
1.562 djm 2014: if (stdfd_devnull(1, 1, 0) == -1)
1.564 djm 2015: error_f("stdfd_devnull failed");
1.296 djm 2016: debug("rexec cleanup in %d out %d newsock %d pipe %d sock %d",
2017: sock_in, sock_out, newsock, startup_pipe, config_s[0]);
1.294 djm 2018: }
1.372 djm 2019:
2020: /* Executed child processes don't need these. */
2021: fcntl(sock_out, F_SETFD, FD_CLOEXEC);
2022: fcntl(sock_in, F_SETFD, FD_CLOEXEC);
1.64 markus 2023:
1.551 dtucker 2024: /* We will not restart on SIGHUP since it no longer makes sense. */
1.544 dtucker 2025: ssh_signal(SIGALRM, SIG_DFL);
2026: ssh_signal(SIGHUP, SIG_DFL);
2027: ssh_signal(SIGTERM, SIG_DFL);
2028: ssh_signal(SIGQUIT, SIG_DFL);
2029: ssh_signal(SIGCHLD, SIG_DFL);
1.150 markus 2030:
1.66 markus 2031: /*
2032: * Register our connection. This turns encryption off because we do
2033: * not have a key.
2034: */
1.525 djm 2035: if ((ssh = ssh_packet_set_connection(NULL, sock_in, sock_out)) == NULL)
2036: fatal("Unable to create connection");
1.527 djm 2037: the_active_state = ssh;
1.525 djm 2038: ssh_packet_set_server(ssh);
1.492 djm 2039:
1.466 djm 2040: check_ip_options(ssh);
1.309 djm 2041:
1.492 djm 2042: /* Prepare the channels layer */
2043: channel_init_channels(ssh);
2044: channel_set_af(ssh, options.address_family);
1.595 djm 2045: process_channel_timeouts(ssh, &options);
1.492 djm 2046: process_permitopen(ssh, &options);
2047:
1.309 djm 2048: /* Set SO_KEEPALIVE if requested. */
1.525 djm 2049: if (options.tcp_keep_alive && ssh_packet_connection_is_on_socket(ssh) &&
1.537 deraadt 2050: setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) == -1)
1.309 djm 2051: error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1.1 deraadt 2052:
1.466 djm 2053: if ((remote_port = ssh_remote_port(ssh)) < 0) {
2054: debug("ssh_remote_port failed");
1.310 markus 2055: cleanup_exit(255);
2056: }
1.316 dtucker 2057:
2058: /*
1.331 markus 2059: * The rest of the code depends on the fact that
1.466 djm 2060: * ssh_remote_ipaddr() caches the remote ip, even if
1.331 markus 2061: * the socket goes away.
2062: */
1.466 djm 2063: remote_ip = ssh_remote_ipaddr(ssh);
1.209 markus 2064:
1.496 djm 2065: rdomain = ssh_packet_rdomain_in(ssh);
2066:
1.64 markus 2067: /* Log the connection. */
1.447 dtucker 2068: laddr = get_local_ipaddr(sock_in);
1.497 djm 2069: verbose("Connection from %s port %d on %s port %d%s%s%s",
1.496 djm 2070: remote_ip, remote_port, laddr, ssh_local_port(ssh),
1.497 djm 2071: rdomain == NULL ? "" : " rdomain \"",
2072: rdomain == NULL ? "" : rdomain,
2073: rdomain == NULL ? "" : "\"");
1.447 dtucker 2074: free(laddr);
1.1 deraadt 2075:
1.66 markus 2076: /*
1.317 djm 2077: * We don't want to listen forever unless the other side
1.66 markus 2078: * successfully authenticates itself. So we set up an alarm which is
2079: * cleared after successful authentication. A limit of zero
1.317 djm 2080: * indicates no limit. Note that we don't set the alarm in debugging
1.66 markus 2081: * mode; it is just annoying to have the server exit just when you
2082: * are about to discover the bug.
2083: */
1.544 dtucker 2084: ssh_signal(SIGALRM, grace_alarm_handler);
1.64 markus 2085: if (!debug_flag)
2086: alarm(options.login_grace_time);
2087:
1.552 djm 2088: if ((r = kex_exchange_identification(ssh, -1,
2089: options.version_addendum)) != 0)
2090: sshpkt_fatal(ssh, r, "banner exchange");
1.520 djm 2091:
1.525 djm 2092: ssh_packet_set_nonblocking(ssh);
1.1 deraadt 2093:
1.278 markus 2094: /* allocate authentication context */
1.329 djm 2095: authctxt = xcalloc(1, sizeof(*authctxt));
1.525 djm 2096: ssh->authctxt = authctxt;
1.278 markus 2097:
2098: /* XXX global for cleanup, access from other modules */
2099: the_authctxt = authctxt;
1.506 djm 2100:
2101: /* Set default key authentication options */
2102: if ((auth_opts = sshauthopt_new_with_keys_defaults()) == NULL)
2103: fatal("allocation failed");
1.278 markus 2104:
1.307 otto 2105: /* prepare buffer to collect messages to display to user after login */
1.510 markus 2106: if ((loginmsg = sshbuf_new()) == NULL)
1.564 djm 2107: fatal_f("sshbuf_new failed");
1.374 dtucker 2108: auth_debug_reset();
1.307 otto 2109:
1.404 markus 2110: if (use_privsep) {
1.525 djm 2111: if (privsep_preauth(ssh) == 1)
1.237 markus 2112: goto authenticated;
1.472 markus 2113: } else if (have_agent) {
1.432 djm 2114: if ((r = ssh_get_authentication_socket(&auth_sock)) != 0) {
1.564 djm 2115: error_r(r, "Unable to get agent socket");
1.433 djm 2116: have_agent = 0;
1.432 djm 2117: }
2118: }
1.231 provos 2119:
1.77 markus 2120: /* perform the key exchange */
2121: /* authenticate user and start session */
1.525 djm 2122: do_ssh2_kex(ssh);
1.524 djm 2123: do_authentication2(ssh);
1.472 markus 2124:
1.237 markus 2125: /*
2126: * If we use privilege separation, the unprivileged child transfers
2127: * the current keystate and exits
2128: */
2129: if (use_privsep) {
1.527 djm 2130: mm_send_keystate(ssh, pmonitor);
1.525 djm 2131: ssh_packet_clear_keys(ssh);
1.231 provos 2132: exit(0);
1.237 markus 2133: }
1.231 provos 2134:
2135: authenticated:
1.318 djm 2136: /*
2137: * Cancel the alarm we set to limit the time taken for
2138: * authentication.
2139: */
2140: alarm(0);
1.544 dtucker 2141: ssh_signal(SIGALRM, SIG_DFL);
1.347 markus 2142: authctxt->authenticated = 1;
1.318 djm 2143: if (startup_pipe != -1) {
2144: close(startup_pipe);
2145: startup_pipe = -1;
2146: }
1.495 djm 2147:
2148: if (options.routing_domain != NULL)
2149: set_process_rdomain(ssh, options.routing_domain);
1.318 djm 2150:
1.234 markus 2151: /*
1.231 provos 2152: * In privilege separation, we fork another child and prepare
2153: * file descriptor passing.
2154: */
2155: if (use_privsep) {
1.525 djm 2156: privsep_postauth(ssh, authctxt);
1.237 markus 2157: /* the monitor process [priv] will not return */
1.231 provos 2158: }
1.360 dtucker 2159:
1.525 djm 2160: ssh_packet_set_timeout(ssh, options.client_alive_interval,
1.360 dtucker 2161: options.client_alive_count_max);
1.439 djm 2162:
2163: /* Try to send all our hostkeys to the client */
1.492 djm 2164: notify_hostkeys(ssh);
1.230 provos 2165:
1.278 markus 2166: /* Start session. */
1.492 djm 2167: do_authenticated(ssh, authctxt);
1.230 provos 2168:
1.64 markus 2169: /* The connection has been terminated. */
1.525 djm 2170: ssh_packet_get_bytes(ssh, &ibytes, &obytes);
1.381 djm 2171: verbose("Transferred: sent %llu, received %llu bytes",
2172: (unsigned long long)obytes, (unsigned long long)ibytes);
1.364 markus 2173:
2174: verbose("Closing connection to %.500s port %d", remote_ip, remote_port);
1.525 djm 2175: ssh_packet_close(ssh);
1.231 provos 2176:
2177: if (use_privsep)
2178: mm_terminate();
2179:
1.64 markus 2180: exit(0);
1.1 deraadt 2181: }
1.98 markus 2182:
1.435 markus 2183: int
1.527 djm 2184: sshd_hostkey_sign(struct ssh *ssh, struct sshkey *privkey,
2185: struct sshkey *pubkey, u_char **signature, size_t *slenp,
2186: const u_char *data, size_t dlen, const char *alg)
1.404 markus 2187: {
1.432 djm 2188: int r;
2189:
1.527 djm 2190: if (use_privsep) {
2191: if (privkey) {
2192: if (mm_sshkey_sign(ssh, privkey, signature, slenp,
1.561 djm 2193: data, dlen, alg, options.sk_provider, NULL,
1.542 djm 2194: ssh->compat) < 0)
1.564 djm 2195: fatal_f("privkey sign failed");
1.527 djm 2196: } else {
2197: if (mm_sshkey_sign(ssh, pubkey, signature, slenp,
1.561 djm 2198: data, dlen, alg, options.sk_provider, NULL,
1.542 djm 2199: ssh->compat) < 0)
1.564 djm 2200: fatal_f("pubkey sign failed");
1.527 djm 2201: }
1.404 markus 2202: } else {
1.527 djm 2203: if (privkey) {
2204: if (sshkey_sign(privkey, signature, slenp, data, dlen,
1.561 djm 2205: alg, options.sk_provider, NULL, ssh->compat) < 0)
1.564 djm 2206: fatal_f("privkey sign failed");
1.527 djm 2207: } else {
2208: if ((r = ssh_agent_sign(auth_sock, pubkey,
2209: signature, slenp, data, dlen, alg,
2210: ssh->compat)) != 0) {
1.564 djm 2211: fatal_fr(r, "agent sign failed");
1.527 djm 2212: }
2213: }
1.404 markus 2214: }
1.435 markus 2215: return 0;
1.404 markus 2216: }
2217:
1.452 djm 2218: /* SSH2 key exchange */
1.200 itojun 2219: static void
1.525 djm 2220: do_ssh2_kex(struct ssh *ssh)
1.98 markus 2221: {
1.599 dtucker 2222: char *hkalgs = NULL, *myproposal[PROPOSAL_MAX];
2223: const char *compression = NULL;
1.435 markus 2224: struct kex *kex;
1.437 markus 2225: int r;
1.102 markus 2226:
1.400 dtucker 2227: if (options.rekey_limit || options.rekey_interval)
1.525 djm 2228: ssh_packet_set_rekey_limits(ssh, options.rekey_limit,
1.481 dtucker 2229: options.rekey_interval);
1.327 deraadt 2230:
1.599 dtucker 2231: if (options.compression == COMP_NONE)
2232: compression = "none";
2233: hkalgs = list_hostkey_types();
2234:
2235: kex_proposal_populate_entries(ssh, myproposal, options.kex_algorithms,
2236: options.ciphers, options.macs, compression, hkalgs);
2237:
2238: free(hkalgs);
1.134 markus 2239:
1.189 markus 2240: /* start key exchange */
1.525 djm 2241: if ((r = kex_setup(ssh, myproposal)) != 0)
1.564 djm 2242: fatal_r(r, "kex_setup");
1.525 djm 2243: kex = ssh->kex;
1.426 markus 2244: #ifdef WITH_OPENSSL
1.532 djm 2245: kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_server;
2246: kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_server;
2247: kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_server;
2248: kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_server;
2249: kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_server;
1.263 markus 2250: kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1.324 djm 2251: kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1.532 djm 2252: kex->kex[KEX_ECDH_SHA2] = kex_gen_server;
1.426 markus 2253: #endif
1.532 djm 2254: kex->kex[KEX_C25519_SHA256] = kex_gen_server;
1.566 djm 2255: kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_server;
1.373 djm 2256: kex->load_host_public_key=&get_hostkey_public_by_type;
2257: kex->load_host_private_key=&get_hostkey_private_by_type;
1.231 provos 2258: kex->host_key_index=&get_hostkey_index;
1.404 markus 2259: kex->sign = sshd_hostkey_sign;
1.189 markus 2260:
1.525 djm 2261: ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &kex->done);
1.129 provos 2262:
2263: #ifdef DEBUG_KEXDH
2264: /* send 1st encrypted/maced/compressed message */
1.553 djm 2265: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2266: (r = sshpkt_put_cstring(ssh, "markus")) != 0 ||
2267: (r = sshpkt_send(ssh)) != 0 ||
2268: (r = ssh_packet_write_wait(ssh)) != 0)
1.564 djm 2269: fatal_fr(r, "send test");
1.129 provos 2270: #endif
1.599 dtucker 2271: kex_proposal_free_entries(myproposal);
1.186 markus 2272: debug("KEX done");
1.278 markus 2273: }
2274:
2275: /* server specific fatal cleanup */
2276: void
2277: cleanup_exit(int i)
2278: {
1.527 djm 2279: if (the_active_state != NULL && the_authctxt != NULL) {
2280: do_cleanup(the_active_state, the_authctxt);
1.423 djm 2281: if (use_privsep && privsep_is_preauth &&
2282: pmonitor != NULL && pmonitor->m_pid > 1) {
1.386 djm 2283: debug("Killing privsep child %d", pmonitor->m_pid);
2284: if (kill(pmonitor->m_pid, SIGKILL) != 0 &&
1.564 djm 2285: errno != ESRCH) {
2286: error_f("kill(%d): %s", pmonitor->m_pid,
2287: strerror(errno));
2288: }
1.386 djm 2289: }
2290: }
1.278 markus 2291: _exit(i);
1.1 deraadt 2292: }
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