Annotation of src/usr.bin/ssh/sshd.c, Revision 1.596
1.596 ! millert 1: /* $OpenBSD: sshd.c,v 1.595 2023/01/06 02:47:19 djm 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"
88: #include "myproposal.h"
1.108 markus 89: #include "authfile.h"
1.154 markus 90: #include "pathnames.h"
1.155 markus 91: #include "atomicio.h"
92: #include "canohost.h"
1.343 deraadt 93: #include "hostfile.h"
1.155 markus 94: #include "auth.h"
1.404 markus 95: #include "authfd.h"
1.294 djm 96: #include "msg.h"
1.186 markus 97: #include "dispatch.h"
1.206 stevesk 98: #include "channels.h"
1.230 provos 99: #include "session.h"
1.231 provos 100: #include "monitor.h"
1.343 deraadt 101: #ifdef GSSAPI
102: #include "ssh-gss.h"
103: #endif
1.231 provos 104: #include "monitor_wrap.h"
1.385 djm 105: #include "ssh-sandbox.h"
1.506 djm 106: #include "auth-options.h"
1.332 stevesk 107: #include "version.h"
1.432 djm 108: #include "ssherr.h"
1.542 djm 109: #include "sk-api.h"
1.567 dtucker 110: #include "srclimit.h"
1.571 dtucker 111: #include "dh.h"
1.522 djm 112:
1.296 djm 113: /* Re-exec fds */
114: #define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1)
115: #define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2)
116: #define REEXEC_CONFIG_PASS_FD (STDERR_FILENO + 3)
117: #define REEXEC_MIN_FREE_FD (STDERR_FILENO + 4)
118:
1.138 markus 119: extern char *__progname;
120:
1.1 deraadt 121: /* Server configuration options. */
122: ServerOptions options;
123:
124: /* Name of the server configuration file. */
1.154 markus 125: char *config_file_name = _PATH_SERVER_CONFIG_FILE;
1.1 deraadt 126:
1.105 markus 127: /*
1.65 deraadt 128: * Debug mode flag. This can be set on the command line. If debug
129: * mode is enabled, extra debugging output will be sent to the system
130: * log, the daemon will not go to background, and will exit after processing
131: * the first connection.
132: */
1.1 deraadt 133: int debug_flag = 0;
134:
1.499 djm 135: /*
136: * Indicating that the daemon should only test the configuration and keys.
137: * If test_flag > 1 ("-T" flag), then sshd will also dump the effective
138: * configuration, optionally using connection information provided by the
139: * "-C" flag.
140: */
1.521 djm 141: static int test_flag = 0;
1.203 stevesk 142:
1.1 deraadt 143: /* Flag indicating that the daemon is being started from inetd. */
1.521 djm 144: static int inetd_flag = 0;
1.1 deraadt 145:
1.135 markus 146: /* Flag indicating that sshd should not detach and become a daemon. */
1.521 djm 147: static int no_daemon_flag = 0;
1.135 markus 148:
1.47 markus 149: /* debug goes to stderr unless inetd_flag is set */
1.521 djm 150: static int log_stderr = 0;
1.47 markus 151:
1.1 deraadt 152: /* Saved arguments to main(). */
1.521 djm 153: static char **saved_argv;
1.1 deraadt 154:
1.294 djm 155: /* re-exec */
1.521 djm 156: static int rexeced_flag = 0;
157: static int rexec_flag = 1;
158: static int rexec_argc = 0;
159: static char **rexec_argv;
1.294 djm 160:
1.66 markus 161: /*
1.75 markus 162: * The sockets that the server is listening; this is used in the SIGHUP
163: * signal handler.
1.66 markus 164: */
1.75 markus 165: #define MAX_LISTEN_SOCKS 16
1.521 djm 166: static int listen_socks[MAX_LISTEN_SOCKS];
167: static int num_listen_socks = 0;
1.1 deraadt 168:
1.404 markus 169: /* Daemon's agent connection */
1.432 djm 170: int auth_sock = -1;
1.521 djm 171: static int have_agent = 0;
1.404 markus 172:
1.66 markus 173: /*
174: * Any really sensitive data in the application is contained in this
175: * structure. The idea is that this structure could be locked into memory so
176: * that the pages do not get written into swap. However, there are some
177: * problems. The private key contains BIGNUMs, and we do not (in principle)
178: * have access to the internals of them, and locking just the structure is
179: * not very useful. Currently, memory locking is not implemented.
180: */
1.64 markus 181: struct {
1.488 markus 182: struct sshkey **host_keys; /* all private host keys */
183: struct sshkey **host_pubkeys; /* all public host keys */
184: struct sshkey **host_certificates; /* all public host certificates */
185: int have_ssh2_key;
1.1 deraadt 186: } sensitive_data;
187:
1.199 markus 188: /* This is set to true when a signal is received. */
1.212 markus 189: static volatile sig_atomic_t received_sighup = 0;
190: static volatile sig_atomic_t received_sigterm = 0;
1.1 deraadt 191:
1.125 markus 192: /* record remote hostname or ip */
1.438 deraadt 193: u_int utmp_len = HOST_NAME_MAX+1;
1.125 markus 194:
1.533 djm 195: /*
196: * startup_pipes/flags are used for tracking children of the listening sshd
197: * process early in their lifespans. This tracking is needed for three things:
198: *
199: * 1) Implementing the MaxStartups limit of concurrent unauthenticated
200: * connections.
201: * 2) Avoiding a race condition for SIGHUP processing, where child processes
202: * may have listen_socks open that could collide with main listener process
203: * after it restarts.
204: * 3) Ensuring that rexec'd sshd processes have received their initial state
205: * from the parent listen process before handling SIGHUP.
206: *
207: * Child processes signal that they have completed closure of the listen_socks
208: * and (if applicable) received their rexec state by sending a char over their
209: * sock. Child processes signal that authentication has completed by closing
210: * the sock (or by exiting).
211: */
1.521 djm 212: static int *startup_pipes = NULL;
1.533 djm 213: static int *startup_flags = NULL; /* Indicates child closed listener */
214: static int startup_pipe = -1; /* in child */
1.211 markus 215:
1.231 provos 216: /* variables used for privilege separation */
1.337 dtucker 217: int use_privsep = -1;
1.285 dtucker 218: struct monitor *pmonitor = NULL;
1.386 djm 219: int privsep_is_preauth = 1;
1.231 provos 220:
1.527 djm 221: /* global connection state and authentication contexts */
1.278 markus 222: Authctxt *the_authctxt = NULL;
1.527 djm 223: struct ssh *the_active_state;
1.278 markus 224:
1.506 djm 225: /* global key/cert auth options. XXX move to permanent ssh->authctxt? */
226: struct sshauthopt *auth_opts = NULL;
227:
1.337 dtucker 228: /* sshd_config buffer */
1.511 markus 229: struct sshbuf *cfg;
1.337 dtucker 230:
1.546 djm 231: /* Included files from the configuration file */
232: struct include_list includes = TAILQ_HEAD_INITIALIZER(includes);
233:
1.299 dtucker 234: /* message to be displayed after login */
1.510 markus 235: struct sshbuf *loginmsg;
1.299 dtucker 236:
1.1 deraadt 237: /* Prototypes for various functions defined later in this file. */
1.200 itojun 238: void destroy_sensitive_data(void);
1.231 provos 239: void demote_sensitive_data(void);
1.525 djm 240: static void do_ssh2_kex(struct ssh *);
1.129 provos 241:
1.545 djm 242: static char *listener_proctitle;
243:
1.87 markus 244: /*
1.75 markus 245: * Close all listening sockets
246: */
1.200 itojun 247: static void
1.75 markus 248: close_listen_socks(void)
249: {
250: int i;
1.250 deraadt 251:
1.75 markus 252: for (i = 0; i < num_listen_socks; i++)
253: close(listen_socks[i]);
1.580 djm 254: num_listen_socks = 0;
1.75 markus 255: }
256:
1.211 markus 257: static void
258: close_startup_pipes(void)
259: {
260: int i;
1.250 deraadt 261:
1.211 markus 262: if (startup_pipes)
263: for (i = 0; i < options.max_startups; i++)
264: if (startup_pipes[i] != -1)
265: close(startup_pipes[i]);
266: }
267:
1.75 markus 268: /*
1.65 deraadt 269: * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP;
270: * the effect is to reread the configuration file (and to regenerate
271: * the server key).
272: */
1.327 deraadt 273:
274: /*ARGSUSED*/
1.200 itojun 275: static void
1.64 markus 276: sighup_handler(int sig)
1.1 deraadt 277: {
1.64 markus 278: received_sighup = 1;
1.1 deraadt 279: }
280:
1.65 deraadt 281: /*
282: * Called from the main program after receiving SIGHUP.
283: * Restarts the server.
284: */
1.200 itojun 285: static void
1.165 itojun 286: sighup_restart(void)
1.1 deraadt 287: {
1.264 itojun 288: logit("Received SIGHUP; restarting.");
1.479 dtucker 289: if (options.pid_file != NULL)
290: unlink(options.pid_file);
1.75 markus 291: close_listen_socks();
1.211 markus 292: close_startup_pipes();
1.544 dtucker 293: ssh_signal(SIGHUP, SIG_IGN); /* will be restored after exec */
1.64 markus 294: execv(saved_argv[0], saved_argv);
1.264 itojun 295: logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0],
1.250 deraadt 296: strerror(errno));
1.64 markus 297: exit(1);
1.1 deraadt 298: }
299:
1.65 deraadt 300: /*
301: * Generic signal handler for terminating signals in the master daemon.
302: */
1.327 deraadt 303: /*ARGSUSED*/
1.200 itojun 304: static void
1.64 markus 305: sigterm_handler(int sig)
1.1 deraadt 306: {
1.199 markus 307: received_sigterm = sig;
1.1 deraadt 308: }
309:
1.65 deraadt 310: /*
311: * SIGCHLD handler. This is called whenever a child dies. This will then
1.199 markus 312: * reap any zombies left by exited children.
1.65 deraadt 313: */
1.327 deraadt 314: /*ARGSUSED*/
1.200 itojun 315: static void
1.64 markus 316: main_sigchld_handler(int sig)
1.1 deraadt 317: {
1.250 deraadt 318: int save_errno = errno;
1.239 markus 319: pid_t pid;
1.64 markus 320: int status;
1.544 dtucker 321:
1.239 markus 322: while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
1.537 deraadt 323: (pid == -1 && errno == EINTR))
1.64 markus 324: ;
325: errno = save_errno;
1.1 deraadt 326: }
327:
1.65 deraadt 328: /*
329: * Signal handler for the alarm after the login grace period has expired.
330: */
1.327 deraadt 331: /*ARGSUSED*/
1.200 itojun 332: static void
1.64 markus 333: grace_alarm_handler(int sig)
1.1 deraadt 334: {
1.394 djm 335: /*
336: * Try to kill any processes that we have spawned, E.g. authorized
1.583 dtucker 337: * keys command helpers or privsep children.
1.394 djm 338: */
339: if (getpgid(0) == getpid()) {
1.544 dtucker 340: ssh_signal(SIGTERM, SIG_IGN);
1.416 djm 341: kill(0, SIGTERM);
1.394 djm 342: }
1.285 dtucker 343:
1.64 markus 344: /* Log error and exit. */
1.583 dtucker 345: sigdie("Timeout before authentication for %s port %d",
346: ssh_remote_ipaddr(the_active_state),
347: ssh_remote_port(the_active_state));
1.62 markus 348: }
349:
1.134 markus 350: /* Destroy the host and server keys. They will no longer be needed. */
1.108 markus 351: void
352: destroy_sensitive_data(void)
353: {
1.493 djm 354: u_int i;
1.134 markus 355:
1.217 deraadt 356: for (i = 0; i < options.num_host_key_files; i++) {
1.134 markus 357: if (sensitive_data.host_keys[i]) {
1.512 markus 358: sshkey_free(sensitive_data.host_keys[i]);
1.134 markus 359: sensitive_data.host_keys[i] = NULL;
360: }
1.373 djm 361: if (sensitive_data.host_certificates[i]) {
1.512 markus 362: sshkey_free(sensitive_data.host_certificates[i]);
1.373 djm 363: sensitive_data.host_certificates[i] = NULL;
364: }
1.134 markus 365: }
366: }
367:
1.231 provos 368: /* Demote private to public keys for network child */
369: void
370: demote_sensitive_data(void)
371: {
1.488 markus 372: struct sshkey *tmp;
1.493 djm 373: u_int i;
1.512 markus 374: int r;
1.231 provos 375:
376: for (i = 0; i < options.num_host_key_files; i++) {
377: if (sensitive_data.host_keys[i]) {
1.515 djm 378: if ((r = sshkey_from_private(
379: sensitive_data.host_keys[i], &tmp)) != 0)
1.564 djm 380: fatal_r(r, "could not demote host %s key",
381: sshkey_type(sensitive_data.host_keys[i]));
1.512 markus 382: sshkey_free(sensitive_data.host_keys[i]);
1.231 provos 383: sensitive_data.host_keys[i] = tmp;
384: }
1.373 djm 385: /* Certs do not need demotion */
1.231 provos 386: }
387: }
388:
1.233 markus 389: static void
1.231 provos 390: privsep_preauth_child(void)
391: {
1.253 deraadt 392: gid_t gidset[1];
1.250 deraadt 393: struct passwd *pw;
1.231 provos 394:
395: /* Enable challenge-response authentication for privilege separation */
396: privsep_challenge_enable();
1.419 djm 397:
1.420 markus 398: #ifdef GSSAPI
1.419 djm 399: /* Cache supported mechanism OIDs for later use */
1.516 djm 400: ssh_gssapi_prepare_supported_oids();
1.420 markus 401: #endif
1.231 provos 402:
403: /* Demote the private keys to public keys. */
404: demote_sensitive_data();
405:
1.460 djm 406: /* Demote the child */
407: if (getuid() == 0 || geteuid() == 0) {
408: if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
409: fatal("Privilege separation user %s does not exist",
410: SSH_PRIVSEP_USER);
1.500 djm 411: pw = pwcopy(pw); /* Ensure mutable */
1.460 djm 412: endpwent();
1.500 djm 413: freezero(pw->pw_passwd, strlen(pw->pw_passwd));
1.460 djm 414:
415: /* Change our root directory */
416: if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1)
417: fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR,
418: strerror(errno));
419: if (chdir("/") == -1)
420: fatal("chdir(\"/\"): %s", strerror(errno));
421:
422: /*
423: * Drop our privileges
424: * NB. Can't use setusercontext() after chroot.
425: */
426: debug3("privsep user:group %u:%u", (u_int)pw->pw_uid,
427: (u_int)pw->pw_gid);
428: gidset[0] = pw->pw_gid;
1.537 deraadt 429: if (setgroups(1, gidset) == -1)
1.460 djm 430: fatal("setgroups: %.100s", strerror(errno));
431: permanently_set_uid(pw);
432: }
1.231 provos 433: }
434:
1.278 markus 435: static int
1.525 djm 436: privsep_preauth(struct ssh *ssh)
1.237 markus 437: {
1.432 djm 438: int status, r;
1.237 markus 439: pid_t pid;
1.384 djm 440: struct ssh_sandbox *box = NULL;
1.237 markus 441:
442: /* Set up unprivileged child process to deal with network data */
1.242 mouring 443: pmonitor = monitor_init();
1.237 markus 444: /* Store a pointer to the kex for later rekeying */
1.525 djm 445: pmonitor->m_pkex = &ssh->kex;
1.237 markus 446:
1.393 djm 447: if (use_privsep == PRIVSEP_ON)
1.384 djm 448: box = ssh_sandbox_init();
1.237 markus 449: pid = fork();
450: if (pid == -1) {
451: fatal("fork of unprivileged child failed");
452: } else if (pid != 0) {
1.245 mpech 453: debug2("Network child is on pid %ld", (long)pid);
1.237 markus 454:
1.392 markus 455: pmonitor->m_pid = pid;
1.432 djm 456: if (have_agent) {
457: r = ssh_get_authentication_socket(&auth_sock);
458: if (r != 0) {
1.564 djm 459: error_r(r, "Could not get agent socket");
1.432 djm 460: have_agent = 0;
461: }
462: }
1.384 djm 463: if (box != NULL)
464: ssh_sandbox_parent_preauth(box, pid);
1.526 djm 465: monitor_child_preauth(ssh, pmonitor);
1.237 markus 466:
467: /* Wait for the child's exit status */
1.537 deraadt 468: while (waitpid(pid, &status, 0) == -1) {
1.386 djm 469: if (errno == EINTR)
470: continue;
471: pmonitor->m_pid = -1;
1.564 djm 472: fatal_f("waitpid: %s", strerror(errno));
1.384 djm 473: }
1.386 djm 474: privsep_is_preauth = 0;
475: pmonitor->m_pid = -1;
1.384 djm 476: if (WIFEXITED(status)) {
477: if (WEXITSTATUS(status) != 0)
1.564 djm 478: fatal_f("preauth child exited with status %d",
479: WEXITSTATUS(status));
1.384 djm 480: } else if (WIFSIGNALED(status))
1.564 djm 481: fatal_f("preauth child terminated by signal %d",
482: WTERMSIG(status));
1.384 djm 483: if (box != NULL)
484: ssh_sandbox_parent_finish(box);
485: return 1;
1.237 markus 486: } else {
487: /* child */
1.383 djm 488: close(pmonitor->m_sendfd);
489: close(pmonitor->m_log_recvfd);
1.237 markus 490:
1.383 djm 491: /* Arrange for logging to be sent to the monitor */
492: set_log_handler(mm_log_handler, pmonitor);
1.237 markus 493:
1.460 djm 494: privsep_preauth_child();
1.238 stevesk 495: setproctitle("%s", "[net]");
1.384 djm 496: if (box != NULL)
497: ssh_sandbox_child(box);
498:
499: return 0;
1.237 markus 500: }
501: }
502:
1.233 markus 503: static void
1.525 djm 504: privsep_postauth(struct ssh *ssh, Authctxt *authctxt)
1.231 provos 505: {
1.474 djm 506: if (authctxt->pw->pw_uid == 0) {
1.231 provos 507: /* File descriptor passing is broken or root login */
508: use_privsep = 0;
1.315 djm 509: goto skip;
1.231 provos 510: }
1.234 markus 511:
1.231 provos 512: /* New socket pair */
1.242 mouring 513: monitor_reinit(pmonitor);
1.231 provos 514:
1.242 mouring 515: pmonitor->m_pid = fork();
516: if (pmonitor->m_pid == -1)
1.231 provos 517: fatal("fork of unprivileged child failed");
1.242 mouring 518: else if (pmonitor->m_pid != 0) {
1.364 markus 519: verbose("User child is on pid %ld", (long)pmonitor->m_pid);
1.510 markus 520: sshbuf_reset(loginmsg);
1.526 djm 521: monitor_clear_keystate(ssh, pmonitor);
522: monitor_child_postauth(ssh, pmonitor);
1.231 provos 523:
524: /* NEVERREACHED */
525: exit(0);
526: }
527:
1.383 djm 528: /* child */
529:
1.242 mouring 530: close(pmonitor->m_sendfd);
1.383 djm 531: pmonitor->m_sendfd = -1;
1.231 provos 532:
533: /* Demote the private keys to public keys. */
534: demote_sensitive_data();
1.354 djm 535:
1.231 provos 536: /* Drop privileges */
537: do_setusercontext(authctxt->pw);
538:
1.315 djm 539: skip:
1.231 provos 540: /* It is safe now to apply the key state */
1.526 djm 541: monitor_apply_keystate(ssh, pmonitor);
1.312 markus 542:
543: /*
544: * Tell the packet layer that authentication was successful, since
545: * this information is not part of the key state.
546: */
1.525 djm 547: ssh_packet_set_authenticated(ssh);
1.231 provos 548: }
549:
1.509 djm 550: static void
551: append_hostkey_type(struct sshbuf *b, const char *s)
552: {
553: int r;
554:
555: if (match_pattern_list(s, options.hostkeyalgorithms, 0) != 1) {
1.564 djm 556: debug3_f("%s key not permitted by HostkeyAlgorithms", s);
1.509 djm 557: return;
558: }
559: if ((r = sshbuf_putf(b, "%s%s", sshbuf_len(b) > 0 ? "," : "", s)) != 0)
1.564 djm 560: fatal_fr(r, "sshbuf_putf");
1.509 djm 561: }
562:
1.200 itojun 563: static char *
1.134 markus 564: list_hostkey_types(void)
565: {
1.509 djm 566: struct sshbuf *b;
567: struct sshkey *key;
1.281 jakob 568: char *ret;
1.493 djm 569: u_int i;
1.223 markus 570:
1.509 djm 571: if ((b = sshbuf_new()) == NULL)
1.564 djm 572: fatal_f("sshbuf_new failed");
1.217 deraadt 573: for (i = 0; i < options.num_host_key_files; i++) {
1.373 djm 574: key = sensitive_data.host_keys[i];
1.443 djm 575: if (key == NULL)
1.404 markus 576: key = sensitive_data.host_pubkeys[i];
1.472 markus 577: if (key == NULL)
1.134 markus 578: continue;
1.214 deraadt 579: switch (key->type) {
1.134 markus 580: case KEY_RSA:
1.509 djm 581: /* for RSA we also support SHA2 signatures */
582: append_hostkey_type(b, "rsa-sha2-512");
583: append_hostkey_type(b, "rsa-sha2-256");
584: /* FALLTHROUGH */
1.134 markus 585: case KEY_DSA:
1.378 djm 586: case KEY_ECDSA:
1.412 markus 587: case KEY_ED25519:
1.542 djm 588: case KEY_ECDSA_SK:
589: case KEY_ED25519_SK:
1.505 markus 590: case KEY_XMSS:
1.509 djm 591: append_hostkey_type(b, sshkey_ssh_name(key));
1.134 markus 592: break;
593: }
1.373 djm 594: /* If the private key has a cert peer, then list that too */
595: key = sensitive_data.host_certificates[i];
596: if (key == NULL)
597: continue;
598: switch (key->type) {
599: case KEY_RSA_CERT:
1.509 djm 600: /* for RSA we also support SHA2 signatures */
601: append_hostkey_type(b,
602: "rsa-sha2-512-cert-v01@openssh.com");
603: append_hostkey_type(b,
604: "rsa-sha2-256-cert-v01@openssh.com");
605: /* FALLTHROUGH */
1.373 djm 606: case KEY_DSA_CERT:
1.378 djm 607: case KEY_ECDSA_CERT:
1.412 markus 608: case KEY_ED25519_CERT:
1.542 djm 609: case KEY_ECDSA_SK_CERT:
610: case KEY_ED25519_SK_CERT:
1.505 markus 611: case KEY_XMSS_CERT:
1.509 djm 612: append_hostkey_type(b, sshkey_ssh_name(key));
1.373 djm 613: break;
614: }
1.134 markus 615: }
1.509 djm 616: if ((ret = sshbuf_dup_string(b)) == NULL)
1.564 djm 617: fatal_f("sshbuf_dup_string failed");
1.509 djm 618: sshbuf_free(b);
1.564 djm 619: debug_f("%s", ret);
1.281 jakob 620: return ret;
1.134 markus 621: }
622:
1.488 markus 623: static struct sshkey *
1.440 djm 624: get_hostkey_by_type(int type, int nid, int need_private, struct ssh *ssh)
1.134 markus 625: {
1.493 djm 626: u_int i;
1.488 markus 627: struct sshkey *key;
1.250 deraadt 628:
1.217 deraadt 629: for (i = 0; i < options.num_host_key_files; i++) {
1.375 djm 630: switch (type) {
631: case KEY_RSA_CERT:
632: case KEY_DSA_CERT:
1.378 djm 633: case KEY_ECDSA_CERT:
1.412 markus 634: case KEY_ED25519_CERT:
1.542 djm 635: case KEY_ECDSA_SK_CERT:
636: case KEY_ED25519_SK_CERT:
1.505 markus 637: case KEY_XMSS_CERT:
1.373 djm 638: key = sensitive_data.host_certificates[i];
1.375 djm 639: break;
640: default:
1.373 djm 641: key = sensitive_data.host_keys[i];
1.404 markus 642: if (key == NULL && !need_private)
643: key = sensitive_data.host_pubkeys[i];
1.375 djm 644: break;
645: }
1.542 djm 646: if (key == NULL || key->type != type)
647: continue;
648: switch (type) {
649: case KEY_ECDSA:
650: case KEY_ECDSA_SK:
651: case KEY_ECDSA_CERT:
652: case KEY_ECDSA_SK_CERT:
653: if (key->ecdsa_nid != nid)
654: continue;
655: /* FALLTHROUGH */
656: default:
1.373 djm 657: return need_private ?
658: sensitive_data.host_keys[i] : key;
1.542 djm 659: }
1.134 markus 660: }
661: return NULL;
1.96 markus 662: }
663:
1.488 markus 664: struct sshkey *
1.440 djm 665: get_hostkey_public_by_type(int type, int nid, struct ssh *ssh)
1.373 djm 666: {
1.440 djm 667: return get_hostkey_by_type(type, nid, 0, ssh);
1.373 djm 668: }
669:
1.488 markus 670: struct sshkey *
1.440 djm 671: get_hostkey_private_by_type(int type, int nid, struct ssh *ssh)
1.373 djm 672: {
1.440 djm 673: return get_hostkey_by_type(type, nid, 1, ssh);
1.373 djm 674: }
675:
1.488 markus 676: struct sshkey *
1.231 provos 677: get_hostkey_by_index(int ind)
678: {
1.493 djm 679: if (ind < 0 || (u_int)ind >= options.num_host_key_files)
1.231 provos 680: return (NULL);
681: return (sensitive_data.host_keys[ind]);
682: }
683:
1.488 markus 684: struct sshkey *
1.435 markus 685: get_hostkey_public_by_index(int ind, struct ssh *ssh)
1.404 markus 686: {
1.493 djm 687: if (ind < 0 || (u_int)ind >= options.num_host_key_files)
1.404 markus 688: return (NULL);
689: return (sensitive_data.host_pubkeys[ind]);
690: }
691:
1.231 provos 692: int
1.488 markus 693: get_hostkey_index(struct sshkey *key, int compare, struct ssh *ssh)
1.231 provos 694: {
1.493 djm 695: u_int i;
1.250 deraadt 696:
1.231 provos 697: for (i = 0; i < options.num_host_key_files; i++) {
1.512 markus 698: if (sshkey_is_cert(key)) {
1.442 djm 699: if (key == sensitive_data.host_certificates[i] ||
700: (compare && sensitive_data.host_certificates[i] &&
701: sshkey_equal(key,
702: sensitive_data.host_certificates[i])))
1.373 djm 703: return (i);
704: } else {
1.442 djm 705: if (key == sensitive_data.host_keys[i] ||
706: (compare && sensitive_data.host_keys[i] &&
707: sshkey_equal(key, sensitive_data.host_keys[i])))
1.373 djm 708: return (i);
1.442 djm 709: if (key == sensitive_data.host_pubkeys[i] ||
710: (compare && sensitive_data.host_pubkeys[i] &&
711: sshkey_equal(key, sensitive_data.host_pubkeys[i])))
1.404 markus 712: return (i);
1.373 djm 713: }
1.231 provos 714: }
715: return (-1);
716: }
717:
1.439 djm 718: /* Inform the client of all hostkeys */
719: static void
720: notify_hostkeys(struct ssh *ssh)
721: {
722: struct sshbuf *buf;
723: struct sshkey *key;
1.493 djm 724: u_int i, nkeys;
725: int r;
1.439 djm 726: char *fp;
1.446 dtucker 727:
728: /* Some clients cannot cope with the hostkeys message, skip those. */
1.527 djm 729: if (ssh->compat & SSH_BUG_HOSTKEYS)
1.446 dtucker 730: return;
1.439 djm 731:
732: if ((buf = sshbuf_new()) == NULL)
1.564 djm 733: fatal_f("sshbuf_new");
1.439 djm 734: for (i = nkeys = 0; i < options.num_host_key_files; i++) {
735: key = get_hostkey_public_by_index(i, ssh);
736: if (key == NULL || key->type == KEY_UNSPEC ||
1.472 markus 737: sshkey_is_cert(key))
1.439 djm 738: continue;
739: fp = sshkey_fingerprint(key, options.fingerprint_hash,
740: SSH_FP_DEFAULT);
1.564 djm 741: debug3_f("key %d: %s %s", i, sshkey_ssh_name(key), fp);
1.439 djm 742: free(fp);
1.442 djm 743: if (nkeys == 0) {
1.525 djm 744: /*
745: * Start building the request when we find the
746: * first usable key.
747: */
748: if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
749: (r = sshpkt_put_cstring(ssh, "hostkeys-00@openssh.com")) != 0 ||
750: (r = sshpkt_put_u8(ssh, 0)) != 0) /* want reply */
751: sshpkt_fatal(ssh, r, "%s: start request", __func__);
1.442 djm 752: }
1.525 djm 753: /* Append the key to the request */
1.442 djm 754: sshbuf_reset(buf);
755: if ((r = sshkey_putb(key, buf)) != 0)
1.564 djm 756: fatal_fr(r, "couldn't put hostkey %d", i);
1.525 djm 757: if ((r = sshpkt_put_stringb(ssh, buf)) != 0)
758: sshpkt_fatal(ssh, r, "%s: append key", __func__);
1.439 djm 759: nkeys++;
760: }
1.564 djm 761: debug3_f("sent %u hostkeys", nkeys);
1.439 djm 762: if (nkeys == 0)
1.564 djm 763: fatal_f("no hostkeys");
1.525 djm 764: if ((r = sshpkt_send(ssh)) != 0)
765: sshpkt_fatal(ssh, r, "%s: send", __func__);
1.442 djm 766: sshbuf_free(buf);
1.439 djm 767: }
768:
1.124 markus 769: /*
770: * returns 1 if connection should be dropped, 0 otherwise.
771: * dropping starts at connection #max_startups_begin with a probability
772: * of (max_startups_rate/100). the probability increases linearly until
773: * all connections are dropped for startups > max_startups
774: */
1.200 itojun 775: static int
1.555 djm 776: should_drop_connection(int startups)
1.124 markus 777: {
1.303 mickey 778: int p, r;
1.124 markus 779:
780: if (startups < options.max_startups_begin)
781: return 0;
782: if (startups >= options.max_startups)
783: return 1;
784: if (options.max_startups_rate == 100)
785: return 1;
786:
787: p = 100 - options.max_startups_rate;
788: p *= startups - options.max_startups_begin;
1.303 mickey 789: p /= options.max_startups - options.max_startups_begin;
1.124 markus 790: p += options.max_startups_rate;
1.356 djm 791: r = arc4random_uniform(100);
1.124 markus 792:
1.564 djm 793: debug_f("p %d, r %d", p, r);
1.124 markus 794: return (r < p) ? 1 : 0;
795: }
796:
1.555 djm 797: /*
798: * Check whether connection should be accepted by MaxStartups.
799: * Returns 0 if the connection is accepted. If the connection is refused,
800: * returns 1 and attempts to send notification to client.
801: * Logs when the MaxStartups condition is entered or exited, and periodically
802: * while in that state.
803: */
804: static int
1.567 dtucker 805: drop_connection(int sock, int startups, int notify_pipe)
1.555 djm 806: {
807: char *laddr, *raddr;
808: const char msg[] = "Exceeded MaxStartups\r\n";
809: static time_t last_drop, first_drop;
810: static u_int ndropped;
811: LogLevel drop_level = SYSLOG_LEVEL_VERBOSE;
812: time_t now;
813:
814: now = monotime();
1.567 dtucker 815: if (!should_drop_connection(startups) &&
816: srclimit_check_allow(sock, notify_pipe) == 1) {
1.555 djm 817: if (last_drop != 0 &&
818: startups < options.max_startups_begin - 1) {
819: /* XXX maybe need better hysteresis here */
820: logit("exited MaxStartups throttling after %s, "
821: "%u connections dropped",
822: fmt_timeframe(now - first_drop), ndropped);
823: last_drop = 0;
824: }
825: return 0;
826: }
827:
828: #define SSHD_MAXSTARTUPS_LOG_INTERVAL (5 * 60)
829: if (last_drop == 0) {
830: error("beginning MaxStartups throttling");
831: drop_level = SYSLOG_LEVEL_INFO;
832: first_drop = now;
833: ndropped = 0;
834: } else if (last_drop + SSHD_MAXSTARTUPS_LOG_INTERVAL < now) {
835: /* Periodic logs */
836: error("in MaxStartups throttling for %s, "
837: "%u connections dropped",
838: fmt_timeframe(now - first_drop), ndropped + 1);
839: drop_level = SYSLOG_LEVEL_INFO;
840: }
841: last_drop = now;
842: ndropped++;
843:
844: laddr = get_local_ipaddr(sock);
845: raddr = get_peer_ipaddr(sock);
846: do_log2(drop_level, "drop connection #%d from [%s]:%d on [%s]:%d "
847: "past MaxStartups", startups, raddr, get_peer_port(sock),
848: laddr, get_local_port(sock));
849: free(laddr);
850: free(raddr);
851: /* best-effort notification to client */
852: (void)write(sock, msg, sizeof(msg) - 1);
853: return 1;
854: }
855:
1.215 markus 856: static void
857: usage(void)
858: {
1.565 dtucker 859: fprintf(stderr, "%s, %s\n", SSH_VERSION, SSH_OPENSSL_VERSION);
1.289 markus 860: fprintf(stderr,
1.596 ! millert 861: "usage: sshd [-46DdeiqTtV] [-C connection_spec] [-c host_cert_file]\n"
1.399 dtucker 862: " [-E log_file] [-f config_file] [-g login_grace_time]\n"
1.473 naddy 863: " [-h host_key_file] [-o option] [-p port] [-u len]\n"
1.289 markus 864: );
1.215 markus 865: exit(1);
866: }
867:
1.294 djm 868: static void
1.467 djm 869: send_rexec_state(int fd, struct sshbuf *conf)
1.294 djm 870: {
1.546 djm 871: struct sshbuf *m = NULL, *inc = NULL;
872: struct include_item *item = NULL;
1.467 djm 873: int r;
1.294 djm 874:
1.564 djm 875: debug3_f("entering fd = %d config len %zu", fd,
1.467 djm 876: sshbuf_len(conf));
1.294 djm 877:
1.546 djm 878: if ((m = sshbuf_new()) == NULL || (inc = sshbuf_new()) == NULL)
1.564 djm 879: fatal_f("sshbuf_new failed");
1.546 djm 880:
881: /* pack includes into a string */
882: TAILQ_FOREACH(item, &includes, entry) {
883: if ((r = sshbuf_put_cstring(inc, item->selector)) != 0 ||
884: (r = sshbuf_put_cstring(inc, item->filename)) != 0 ||
1.547 djm 885: (r = sshbuf_put_stringb(inc, item->contents)) != 0)
1.564 djm 886: fatal_fr(r, "compose includes");
1.546 djm 887: }
888:
1.294 djm 889: /*
890: * Protocol from reexec master to child:
891: * string configuration
1.546 djm 892: * string included_files[] {
893: * string selector
894: * string filename
895: * string contents
896: * }
1.294 djm 897: */
1.546 djm 898: if ((r = sshbuf_put_stringb(m, conf)) != 0 ||
899: (r = sshbuf_put_stringb(m, inc)) != 0)
1.564 djm 900: fatal_fr(r, "compose config");
1.467 djm 901: if (ssh_msg_send(fd, 0, m) == -1)
1.564 djm 902: error_f("ssh_msg_send failed");
1.294 djm 903:
1.467 djm 904: sshbuf_free(m);
1.546 djm 905: sshbuf_free(inc);
1.294 djm 906:
1.564 djm 907: debug3_f("done");
1.294 djm 908: }
909:
910: static void
1.511 markus 911: recv_rexec_state(int fd, struct sshbuf *conf)
1.294 djm 912: {
1.546 djm 913: struct sshbuf *m, *inc;
1.511 markus 914: u_char *cp, ver;
915: size_t len;
916: int r;
1.546 djm 917: struct include_item *item;
1.294 djm 918:
1.564 djm 919: debug3_f("entering fd = %d", fd);
1.294 djm 920:
1.546 djm 921: if ((m = sshbuf_new()) == NULL || (inc = sshbuf_new()) == NULL)
1.564 djm 922: fatal_f("sshbuf_new failed");
1.511 markus 923: if (ssh_msg_recv(fd, m) == -1)
1.564 djm 924: fatal_f("ssh_msg_recv failed");
1.511 markus 925: if ((r = sshbuf_get_u8(m, &ver)) != 0)
1.564 djm 926: fatal_fr(r, "parse version");
1.511 markus 927: if (ver != 0)
1.564 djm 928: fatal_f("rexec version mismatch");
1.546 djm 929: if ((r = sshbuf_get_string(m, &cp, &len)) != 0 ||
930: (r = sshbuf_get_stringb(m, inc)) != 0)
1.564 djm 931: fatal_fr(r, "parse config");
1.546 djm 932:
1.511 markus 933: if (conf != NULL && (r = sshbuf_put(conf, cp, len)))
1.564 djm 934: fatal_fr(r, "sshbuf_put");
1.294 djm 935:
1.546 djm 936: while (sshbuf_len(inc) != 0) {
937: item = xcalloc(1, sizeof(*item));
938: if ((item->contents = sshbuf_new()) == NULL)
1.564 djm 939: fatal_f("sshbuf_new failed");
1.546 djm 940: if ((r = sshbuf_get_cstring(inc, &item->selector, NULL)) != 0 ||
941: (r = sshbuf_get_cstring(inc, &item->filename, NULL)) != 0 ||
942: (r = sshbuf_get_stringb(inc, item->contents)) != 0)
1.564 djm 943: fatal_fr(r, "parse includes");
1.546 djm 944: TAILQ_INSERT_TAIL(&includes, item, entry);
945: }
946:
1.402 djm 947: free(cp);
1.511 markus 948: sshbuf_free(m);
1.294 djm 949:
1.564 djm 950: debug3_f("done");
1.294 djm 951: }
952:
1.345 djm 953: /* Accept a connection from inetd */
954: static void
955: server_accept_inetd(int *sock_in, int *sock_out)
956: {
957: if (rexeced_flag) {
958: close(REEXEC_CONFIG_PASS_FD);
959: *sock_in = *sock_out = dup(STDIN_FILENO);
960: } else {
961: *sock_in = dup(STDIN_FILENO);
962: *sock_out = dup(STDOUT_FILENO);
963: }
964: /*
965: * We intentionally do not close the descriptors 0, 1, and 2
966: * as our code for setting the descriptors won't work if
967: * ttyfd happens to be one of those.
968: */
1.562 djm 969: if (stdfd_devnull(1, 1, !log_stderr) == -1)
1.564 djm 970: error_f("stdfd_devnull failed");
1.345 djm 971: debug("inetd sockets after dupping: %d, %d", *sock_in, *sock_out);
972: }
973:
974: /*
975: * Listen for TCP connections
976: */
977: static void
1.494 djm 978: listen_on_addrs(struct listenaddr *la)
1.345 djm 979: {
1.494 djm 980: int ret, listen_sock;
1.345 djm 981: struct addrinfo *ai;
982: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
983:
1.494 djm 984: for (ai = la->addrs; ai; ai = ai->ai_next) {
1.345 djm 985: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
986: continue;
987: if (num_listen_socks >= MAX_LISTEN_SOCKS)
988: fatal("Too many listen sockets. "
989: "Enlarge MAX_LISTEN_SOCKS");
990: if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen,
991: ntop, sizeof(ntop), strport, sizeof(strport),
992: NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
993: error("getnameinfo failed: %.100s",
1.352 dtucker 994: ssh_gai_strerror(ret));
1.345 djm 995: continue;
996: }
997: /* Create socket for listening. */
1.370 dtucker 998: listen_sock = socket(ai->ai_family, ai->ai_socktype,
999: ai->ai_protocol);
1.537 deraadt 1000: if (listen_sock == -1) {
1.345 djm 1001: /* kernel may not support ipv6 */
1002: verbose("socket: %.100s", strerror(errno));
1003: continue;
1004: }
1005: if (set_nonblock(listen_sock) == -1) {
1.483 djm 1006: close(listen_sock);
1007: continue;
1008: }
1009: if (fcntl(listen_sock, F_SETFD, FD_CLOEXEC) == -1) {
1010: verbose("socket: CLOEXEC: %s", strerror(errno));
1.345 djm 1011: close(listen_sock);
1012: continue;
1013: }
1.494 djm 1014: /* Socket options */
1015: set_reuseaddr(listen_sock);
1016: if (la->rdomain != NULL &&
1017: set_rdomain(listen_sock, la->rdomain) == -1) {
1018: close(listen_sock);
1019: continue;
1020: }
1.345 djm 1021:
1022: debug("Bind to port %s on %s.", strport, ntop);
1023:
1024: /* Bind the socket to the desired port. */
1.537 deraadt 1025: if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) == -1) {
1.345 djm 1026: error("Bind to port %s on %s failed: %.200s.",
1027: strport, ntop, strerror(errno));
1028: close(listen_sock);
1029: continue;
1030: }
1031: listen_socks[num_listen_socks] = listen_sock;
1032: num_listen_socks++;
1033:
1034: /* Start listening on the port. */
1.537 deraadt 1035: if (listen(listen_sock, SSH_LISTEN_BACKLOG) == -1)
1.345 djm 1036: fatal("listen on [%s]:%s: %.100s",
1037: ntop, strport, strerror(errno));
1.494 djm 1038: logit("Server listening on %s port %s%s%s.",
1039: ntop, strport,
1040: la->rdomain == NULL ? "" : " rdomain ",
1041: la->rdomain == NULL ? "" : la->rdomain);
1.345 djm 1042: }
1.494 djm 1043: }
1044:
1045: static void
1046: server_listen(void)
1047: {
1048: u_int i;
1049:
1.567 dtucker 1050: /* Initialise per-source limit tracking. */
1051: srclimit_init(options.max_startups, options.per_source_max_startups,
1052: options.per_source_masklen_ipv4, options.per_source_masklen_ipv6);
1053:
1.494 djm 1054: for (i = 0; i < options.num_listen_addrs; i++) {
1055: listen_on_addrs(&options.listen_addrs[i]);
1056: freeaddrinfo(options.listen_addrs[i].addrs);
1057: free(options.listen_addrs[i].rdomain);
1058: memset(&options.listen_addrs[i], 0,
1059: sizeof(options.listen_addrs[i]));
1060: }
1061: free(options.listen_addrs);
1062: options.listen_addrs = NULL;
1063: options.num_listen_addrs = 0;
1.345 djm 1064:
1065: if (!num_listen_socks)
1066: fatal("Cannot bind any address.");
1067: }
1068:
1069: /*
1070: * The main TCP accept loop. Note that, for the non-debug case, returns
1071: * from this function are in a forked subprocess.
1072: */
1073: static void
1074: server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
1075: {
1.579 deraadt 1076: struct pollfd *pfd = NULL;
1.584 djm 1077: int i, j, ret, npfd;
1.543 djm 1078: int ostartups = -1, startups = 0, listening = 0, lameduck = 0;
1.584 djm 1079: int startup_p[2] = { -1 , -1 }, *startup_pollfd;
1.533 djm 1080: char c = 0;
1.345 djm 1081: struct sockaddr_storage from;
1082: socklen_t fromlen;
1083: pid_t pid;
1.574 dtucker 1084: sigset_t nsigset, osigset;
1.345 djm 1085:
1086: /* setup fd set for accept */
1.550 djm 1087: /* pipes connected to unauthenticated child sshd processes */
1.345 djm 1088: startup_pipes = xcalloc(options.max_startups, sizeof(int));
1.533 djm 1089: startup_flags = xcalloc(options.max_startups, sizeof(int));
1.584 djm 1090: startup_pollfd = xcalloc(options.max_startups, sizeof(int));
1.345 djm 1091: for (i = 0; i < options.max_startups; i++)
1092: startup_pipes[i] = -1;
1093:
1094: /*
1.574 dtucker 1095: * Prepare signal mask that we use to block signals that might set
1096: * received_sigterm or received_sighup, so that we are guaranteed
1.579 deraadt 1097: * to immediately wake up the ppoll if a signal is received after
1.574 dtucker 1098: * the flag is checked.
1099: */
1100: sigemptyset(&nsigset);
1101: sigaddset(&nsigset, SIGHUP);
1102: sigaddset(&nsigset, SIGCHLD);
1103: sigaddset(&nsigset, SIGTERM);
1104: sigaddset(&nsigset, SIGQUIT);
1105:
1.584 djm 1106: /* sized for worst-case */
1.579 deraadt 1107: pfd = xcalloc(num_listen_socks + options.max_startups,
1108: sizeof(struct pollfd));
1109:
1.574 dtucker 1110: /*
1.345 djm 1111: * Stay listening for connections until the system crashes or
1112: * the daemon is killed with a signal.
1113: */
1114: for (;;) {
1.574 dtucker 1115: sigprocmask(SIG_BLOCK, &nsigset, &osigset);
1116: if (received_sigterm) {
1117: logit("Received signal %d; terminating.",
1118: (int) received_sigterm);
1119: close_listen_socks();
1120: if (options.pid_file != NULL)
1121: unlink(options.pid_file);
1122: exit(received_sigterm == SIGTERM ? 0 : 255);
1123: }
1.543 djm 1124: if (ostartups != startups) {
1.545 djm 1125: setproctitle("%s [listener] %d of %d-%d startups",
1126: listener_proctitle, startups,
1127: options.max_startups_begin, options.max_startups);
1.543 djm 1128: ostartups = startups;
1129: }
1.533 djm 1130: if (received_sighup) {
1131: if (!lameduck) {
1132: debug("Received SIGHUP; waiting for children");
1133: close_listen_socks();
1134: lameduck = 1;
1135: }
1.574 dtucker 1136: if (listening <= 0) {
1137: sigprocmask(SIG_SETMASK, &osigset, NULL);
1.533 djm 1138: sighup_restart();
1.574 dtucker 1139: }
1.533 djm 1140: }
1.345 djm 1141:
1.579 deraadt 1142: for (i = 0; i < num_listen_socks; i++) {
1143: pfd[i].fd = listen_socks[i];
1144: pfd[i].events = POLLIN;
1145: }
1.584 djm 1146: npfd = num_listen_socks;
1.579 deraadt 1147: for (i = 0; i < options.max_startups; i++) {
1.584 djm 1148: startup_pollfd[i] = -1;
1149: if (startup_pipes[i] != -1) {
1150: pfd[npfd].fd = startup_pipes[i];
1151: pfd[npfd].events = POLLIN;
1152: startup_pollfd[i] = npfd++;
1153: }
1.579 deraadt 1154: }
1.345 djm 1155:
1.574 dtucker 1156: /* Wait until a connection arrives or a child exits. */
1.584 djm 1157: ret = ppoll(pfd, npfd, NULL, &osigset);
1158: if (ret == -1 && errno != EINTR) {
1.579 deraadt 1159: error("ppoll: %.100s", strerror(errno));
1.584 djm 1160: if (errno == EINVAL)
1161: cleanup_exit(1); /* can't recover */
1162: }
1.574 dtucker 1163: sigprocmask(SIG_SETMASK, &osigset, NULL);
1.576 dtucker 1164: if (ret == -1)
1.345 djm 1165: continue;
1166:
1.533 djm 1167: for (i = 0; i < options.max_startups; i++) {
1168: if (startup_pipes[i] == -1 ||
1.584 djm 1169: startup_pollfd[i] == -1 ||
1170: !(pfd[startup_pollfd[i]].revents & (POLLIN|POLLHUP)))
1.533 djm 1171: continue;
1172: switch (read(startup_pipes[i], &c, sizeof(c))) {
1173: case -1:
1174: if (errno == EINTR || errno == EAGAIN)
1175: continue;
1176: if (errno != EPIPE) {
1.564 djm 1177: error_f("startup pipe %d (fd=%d): "
1178: "read %s", i, startup_pipes[i],
1179: strerror(errno));
1.533 djm 1180: }
1181: /* FALLTHROUGH */
1182: case 0:
1183: /* child exited or completed auth */
1.345 djm 1184: close(startup_pipes[i]);
1.567 dtucker 1185: srclimit_done(startup_pipes[i]);
1.345 djm 1186: startup_pipes[i] = -1;
1187: startups--;
1.533 djm 1188: if (startup_flags[i])
1189: listening--;
1190: break;
1191: case 1:
1192: /* child has finished preliminaries */
1193: if (startup_flags[i]) {
1194: listening--;
1195: startup_flags[i] = 0;
1196: }
1197: break;
1.345 djm 1198: }
1.533 djm 1199: }
1.345 djm 1200: for (i = 0; i < num_listen_socks; i++) {
1.579 deraadt 1201: if (!(pfd[i].revents & POLLIN))
1.345 djm 1202: continue;
1203: fromlen = sizeof(from);
1204: *newsock = accept(listen_socks[i],
1205: (struct sockaddr *)&from, &fromlen);
1.537 deraadt 1206: if (*newsock == -1) {
1.398 markus 1207: if (errno != EINTR && errno != EWOULDBLOCK &&
1208: errno != ECONNABORTED)
1.389 djm 1209: error("accept: %.100s",
1210: strerror(errno));
1211: if (errno == EMFILE || errno == ENFILE)
1212: usleep(100 * 1000);
1.345 djm 1213: continue;
1214: }
1.586 dtucker 1215: if (unset_nonblock(*newsock) == -1) {
1216: close(*newsock);
1217: continue;
1218: }
1219: if (pipe(startup_p) == -1) {
1220: error_f("pipe(startup_p): %s", strerror(errno));
1.582 djm 1221: close(*newsock);
1.567 dtucker 1222: continue;
1.582 djm 1223: }
1.567 dtucker 1224: if (drop_connection(*newsock, startups, startup_p[0])) {
1.345 djm 1225: close(*newsock);
1.567 dtucker 1226: close(startup_p[0]);
1227: close(startup_p[1]);
1.345 djm 1228: continue;
1229: }
1230:
1231: if (rexec_flag && socketpair(AF_UNIX,
1232: SOCK_STREAM, 0, config_s) == -1) {
1233: error("reexec socketpair: %s",
1234: strerror(errno));
1235: close(*newsock);
1236: close(startup_p[0]);
1237: close(startup_p[1]);
1238: continue;
1239: }
1240:
1241: for (j = 0; j < options.max_startups; j++)
1242: if (startup_pipes[j] == -1) {
1243: startup_pipes[j] = startup_p[0];
1244: startups++;
1.533 djm 1245: startup_flags[j] = 1;
1.345 djm 1246: break;
1247: }
1248:
1249: /*
1250: * Got connection. Fork a child to handle it, unless
1251: * we are in debugging mode.
1252: */
1253: if (debug_flag) {
1254: /*
1255: * In debugging mode. Close the listening
1256: * socket, and start processing the
1257: * connection without forking.
1258: */
1259: debug("Server will not fork when running in debugging mode.");
1260: close_listen_socks();
1261: *sock_in = *newsock;
1262: *sock_out = *newsock;
1263: close(startup_p[0]);
1264: close(startup_p[1]);
1265: startup_pipe = -1;
1266: pid = getpid();
1267: if (rexec_flag) {
1.511 markus 1268: send_rexec_state(config_s[0], cfg);
1.345 djm 1269: close(config_s[0]);
1270: }
1.579 deraadt 1271: free(pfd);
1.533 djm 1272: return;
1.345 djm 1273: }
1274:
1275: /*
1276: * Normal production daemon. Fork, and have
1277: * the child process the connection. The
1278: * parent continues listening.
1279: */
1.533 djm 1280: listening++;
1.345 djm 1281: if ((pid = fork()) == 0) {
1282: /*
1283: * Child. Close the listening and
1284: * max_startup sockets. Start using
1285: * the accepted socket. Reinitialize
1286: * logging (since our pid has changed).
1.533 djm 1287: * We return from this function to handle
1.345 djm 1288: * the connection.
1289: */
1290: startup_pipe = startup_p[1];
1291: close_startup_pipes();
1292: close_listen_socks();
1293: *sock_in = *newsock;
1294: *sock_out = *newsock;
1295: log_init(__progname,
1296: options.log_level,
1297: options.log_facility,
1298: log_stderr);
1299: if (rexec_flag)
1300: close(config_s[0]);
1.533 djm 1301: else {
1302: /*
1303: * Signal parent that the preliminaries
1304: * for this child are complete. For the
1305: * re-exec case, this happens after the
1306: * child has received the rexec state
1307: * from the server.
1308: */
1309: (void)atomicio(vwrite, startup_pipe,
1310: "\0", 1);
1311: }
1.579 deraadt 1312: free(pfd);
1.533 djm 1313: return;
1.345 djm 1314: }
1315:
1316: /* Parent. Stay in the loop. */
1.537 deraadt 1317: if (pid == -1)
1.345 djm 1318: error("fork: %.100s", strerror(errno));
1319: else
1320: debug("Forked child %ld.", (long)pid);
1321:
1322: close(startup_p[1]);
1323:
1324: if (rexec_flag) {
1.554 markus 1325: close(config_s[1]);
1.511 markus 1326: send_rexec_state(config_s[0], cfg);
1.345 djm 1327: close(config_s[0]);
1328: }
1329: close(*newsock);
1330: }
1331: }
1332: }
1333:
1.466 djm 1334: /*
1335: * If IP options are supported, make sure there are none (log and
1336: * return an error if any are found). Basically we are worried about
1337: * source routing; it can be used to pretend you are somebody
1338: * (ip-address) you are not. That itself may be "almost acceptable"
1.507 djm 1339: * under certain circumstances, but rhosts authentication is useless
1.466 djm 1340: * if source routing is accepted. Notice also that if we just dropped
1341: * source routing here, the other side could use IP spoofing to do
1342: * rest of the interaction and could still bypass security. So we
1343: * exit here if we detect any IP options.
1344: */
1345: static void
1346: check_ip_options(struct ssh *ssh)
1347: {
1348: int sock_in = ssh_packet_get_connection_in(ssh);
1349: struct sockaddr_storage from;
1350: u_char opts[200];
1.475 djm 1351: socklen_t i, option_size = sizeof(opts), fromlen = sizeof(from);
1.466 djm 1352: char text[sizeof(opts) * 3 + 1];
1353:
1354: memset(&from, 0, sizeof(from));
1355: if (getpeername(sock_in, (struct sockaddr *)&from,
1.537 deraadt 1356: &fromlen) == -1)
1.466 djm 1357: return;
1358: if (from.ss_family != AF_INET)
1359: return;
1360: /* XXX IPv6 options? */
1361:
1362: if (getsockopt(sock_in, IPPROTO_IP, IP_OPTIONS, opts,
1363: &option_size) >= 0 && option_size != 0) {
1364: text[0] = '\0';
1365: for (i = 0; i < option_size; i++)
1366: snprintf(text + i*3, sizeof(text) - i*3,
1367: " %2.2x", opts[i]);
1368: fatal("Connection from %.100s port %d with IP opts: %.800s",
1369: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), text);
1370: }
1371: return;
1372: }
1.345 djm 1373:
1.495 djm 1374: /* Set the routing domain for this process */
1375: static void
1376: set_process_rdomain(struct ssh *ssh, const char *name)
1377: {
1378: int rtable, ortable = getrtable();
1379: const char *errstr;
1380:
1381: if (name == NULL)
1382: return; /* default */
1383:
1384: if (strcmp(name, "%D") == 0) {
1385: /* "expands" to routing domain of connection */
1386: if ((name = ssh_packet_rdomain_in(ssh)) == NULL)
1387: return;
1388: }
1389:
1390: rtable = (int)strtonum(name, 0, 255, &errstr);
1391: if (errstr != NULL) /* Shouldn't happen */
1392: fatal("Invalid routing domain \"%s\": %s", name, errstr);
1393: if (rtable != ortable && setrtable(rtable) != 0)
1394: fatal("Unable to set routing domain %d: %s",
1395: rtable, strerror(errno));
1.564 djm 1396: debug_f("set routing domain %d (was %d)", rtable, ortable);
1.495 djm 1397: }
1398:
1.508 dtucker 1399: static void
1400: accumulate_host_timing_secret(struct sshbuf *server_cfg,
1.536 djm 1401: struct sshkey *key)
1.508 dtucker 1402: {
1403: static struct ssh_digest_ctx *ctx;
1404: u_char *hash;
1405: size_t len;
1406: struct sshbuf *buf;
1407: int r;
1408:
1409: if (ctx == NULL && (ctx = ssh_digest_start(SSH_DIGEST_SHA512)) == NULL)
1.564 djm 1410: fatal_f("ssh_digest_start");
1.508 dtucker 1411: if (key == NULL) { /* finalize */
1412: /* add server config in case we are using agent for host keys */
1413: if (ssh_digest_update(ctx, sshbuf_ptr(server_cfg),
1414: sshbuf_len(server_cfg)) != 0)
1.564 djm 1415: fatal_f("ssh_digest_update");
1.508 dtucker 1416: len = ssh_digest_bytes(SSH_DIGEST_SHA512);
1417: hash = xmalloc(len);
1418: if (ssh_digest_final(ctx, hash, len) != 0)
1.564 djm 1419: fatal_f("ssh_digest_final");
1.508 dtucker 1420: options.timing_secret = PEEK_U64(hash);
1421: freezero(hash, len);
1422: ssh_digest_free(ctx);
1423: ctx = NULL;
1424: return;
1425: }
1426: if ((buf = sshbuf_new()) == NULL)
1.564 djm 1427: fatal_f("could not allocate buffer");
1.508 dtucker 1428: if ((r = sshkey_private_serialize(key, buf)) != 0)
1.592 djm 1429: fatal_fr(r, "encode %s key", sshkey_ssh_name(key));
1.508 dtucker 1430: if (ssh_digest_update(ctx, sshbuf_ptr(buf), sshbuf_len(buf)) != 0)
1.564 djm 1431: fatal_f("ssh_digest_update");
1.508 dtucker 1432: sshbuf_reset(buf);
1433: sshbuf_free(buf);
1434: }
1435:
1.545 djm 1436: static char *
1437: prepare_proctitle(int ac, char **av)
1438: {
1439: char *ret = NULL;
1440: int i;
1441:
1442: for (i = 0; i < ac; i++)
1443: xextendf(&ret, " ", "%s", av[i]);
1444: return ret;
1445: }
1446:
1.65 deraadt 1447: /*
1448: * Main program for the daemon.
1449: */
1.2 provos 1450: int
1451: main(int ac, char **av)
1.1 deraadt 1452: {
1.466 djm 1453: struct ssh *ssh = NULL;
1.64 markus 1454: extern char *optarg;
1455: extern int optind;
1.493 djm 1456: int r, opt, on = 1, already_daemon, remote_port;
1.297 avsm 1457: int sock_in = -1, sock_out = -1, newsock = -1;
1.496 djm 1458: const char *remote_ip, *rdomain;
1.447 dtucker 1459: char *fp, *line, *laddr, *logfile = NULL;
1.345 djm 1460: int config_s[2] = { -1 , -1 };
1.493 djm 1461: u_int i, j;
1.364 markus 1462: u_int64_t ibytes, obytes;
1.362 dtucker 1463: mode_t new_umask;
1.488 markus 1464: struct sshkey *key;
1465: struct sshkey *pubkey;
1.404 markus 1466: int keytype;
1.230 provos 1467: Authctxt *authctxt;
1.498 dtucker 1468: struct connection_info *connection_info = NULL;
1.594 djm 1469: sigset_t sigmask;
1470:
1471: sigemptyset(&sigmask);
1472: sigprocmask(SIG_SETMASK, &sigmask, NULL);
1.64 markus 1473:
1.138 markus 1474: /* Save argv. */
1.64 markus 1475: saved_argv = av;
1.294 djm 1476: rexec_argc = ac;
1.313 djm 1477:
1478: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1479: sanitise_stdfd();
1.64 markus 1480:
1481: /* Initialize configuration options to their default values. */
1482: initialize_server_options(&options);
1483:
1484: /* Parse command-line arguments. */
1.450 djm 1485: while ((opt = getopt(ac, av,
1.596 ! millert 1486: "C:E:b:c:f:g:h:k:o:p:u:46DQRTdeiqrtV")) != -1) {
1.64 markus 1487: switch (opt) {
1.75 markus 1488: case '4':
1.305 djm 1489: options.address_family = AF_INET;
1.75 markus 1490: break;
1491: case '6':
1.305 djm 1492: options.address_family = AF_INET6;
1.75 markus 1493: break;
1.64 markus 1494: case 'f':
1495: config_file_name = optarg;
1496: break;
1.373 djm 1497: case 'c':
1.493 djm 1498: servconf_add_hostcert("[command-line]", 0,
1499: &options, optarg);
1.373 djm 1500: break;
1.64 markus 1501: case 'd':
1.273 markus 1502: if (debug_flag == 0) {
1.127 markus 1503: debug_flag = 1;
1504: options.log_level = SYSLOG_LEVEL_DEBUG1;
1.273 markus 1505: } else if (options.log_level < SYSLOG_LEVEL_DEBUG3)
1.127 markus 1506: options.log_level++;
1.64 markus 1507: break;
1.135 markus 1508: case 'D':
1509: no_daemon_flag = 1;
1.192 lebel 1510: break;
1.399 dtucker 1511: case 'E':
1.459 dtucker 1512: logfile = optarg;
1.399 dtucker 1513: /* FALLTHROUGH */
1.192 lebel 1514: case 'e':
1515: log_stderr = 1;
1.135 markus 1516: break;
1.64 markus 1517: case 'i':
1518: inetd_flag = 1;
1519: break;
1.294 djm 1520: case 'r':
1521: rexec_flag = 0;
1522: break;
1523: case 'R':
1524: rexeced_flag = 1;
1525: inetd_flag = 1;
1526: break;
1.64 markus 1527: case 'Q':
1.158 markus 1528: /* ignored */
1.64 markus 1529: break;
1530: case 'q':
1531: options.log_level = SYSLOG_LEVEL_QUIET;
1532: break;
1533: case 'b':
1.473 naddy 1534: /* protocol 1, ignored */
1.64 markus 1535: break;
1536: case 'p':
1.75 markus 1537: options.ports_from_cmdline = 1;
1.127 markus 1538: if (options.num_ports >= MAX_PORTS) {
1539: fprintf(stderr, "too many ports.\n");
1540: exit(1);
1541: }
1.193 stevesk 1542: options.ports[options.num_ports++] = a2port(optarg);
1.366 djm 1543: if (options.ports[options.num_ports-1] <= 0) {
1.193 stevesk 1544: fprintf(stderr, "Bad port number.\n");
1545: exit(1);
1546: }
1.64 markus 1547: break;
1548: case 'g':
1.197 stevesk 1549: if ((options.login_grace_time = convtime(optarg)) == -1) {
1550: fprintf(stderr, "Invalid login grace time.\n");
1551: exit(1);
1552: }
1.64 markus 1553: break;
1554: case 'k':
1.473 naddy 1555: /* protocol 1, ignored */
1.64 markus 1556: break;
1557: case 'h':
1.493 djm 1558: servconf_add_hostkey("[command-line]", 0,
1.519 djm 1559: &options, optarg, 1);
1.64 markus 1560: break;
1.203 stevesk 1561: case 't':
1562: test_flag = 1;
1563: break;
1.358 dtucker 1564: case 'T':
1565: test_flag = 2;
1566: break;
1567: case 'C':
1.523 djm 1568: connection_info = get_connection_info(ssh, 0, 0);
1.391 dtucker 1569: if (parse_server_match_testspec(connection_info,
1570: optarg) == -1)
1571: exit(1);
1.358 dtucker 1572: break;
1.125 markus 1573: case 'u':
1.438 deraadt 1574: utmp_len = (u_int)strtonum(optarg, 0, HOST_NAME_MAX+1+1, NULL);
1575: if (utmp_len > HOST_NAME_MAX+1) {
1.257 stevesk 1576: fprintf(stderr, "Invalid utmp length.\n");
1577: exit(1);
1578: }
1.125 markus 1579: break;
1.215 markus 1580: case 'o':
1.283 markus 1581: line = xstrdup(optarg);
1582: if (process_server_config_line(&options, line,
1.546 djm 1583: "command-line", 0, NULL, NULL, &includes) != 0)
1.217 deraadt 1584: exit(1);
1.402 djm 1585: free(line);
1.215 markus 1586: break;
1.596 ! millert 1587: case 'V':
! 1588: fprintf(stderr, "%s, %s\n",
! 1589: SSH_VERSION, SSH_OPENSSL_VERSION);
! 1590: exit(0);
1.64 markus 1591: default:
1.215 markus 1592: usage();
1593: break;
1.64 markus 1594: }
1595: }
1.294 djm 1596: if (rexeced_flag || inetd_flag)
1597: rexec_flag = 0;
1.518 djm 1598: if (!test_flag && rexec_flag && !path_absolute(av[0]))
1.294 djm 1599: fatal("sshd re-exec requires execution with an absolute path");
1600: if (rexeced_flag)
1.296 djm 1601: closefrom(REEXEC_MIN_FREE_FD);
1602: else
1603: closefrom(REEXEC_DEVCRYPTO_RESERVED_FD);
1.294 djm 1604:
1.426 markus 1605: #ifdef WITH_OPENSSL
1.379 djm 1606: OpenSSL_add_all_algorithms();
1.426 markus 1607: #endif
1.64 markus 1608:
1.399 dtucker 1609: /* If requested, redirect the logs to the specified logfile. */
1.459 dtucker 1610: if (logfile != NULL)
1.399 dtucker 1611: log_redirect_stderr_to(logfile);
1.75 markus 1612: /*
1613: * Force logging to stderr until we have loaded the private host
1614: * key (unless started from inetd)
1615: */
1.138 markus 1616: log_init(__progname,
1.224 markus 1617: options.log_level == SYSLOG_LEVEL_NOT_SET ?
1618: SYSLOG_LEVEL_INFO : options.log_level,
1619: options.log_facility == SYSLOG_FACILITY_NOT_SET ?
1620: SYSLOG_FACILITY_AUTH : options.log_facility,
1.548 djm 1621: log_stderr || !inetd_flag || debug_flag);
1.75 markus 1622:
1.294 djm 1623: sensitive_data.have_ssh2_key = 0;
1624:
1.358 dtucker 1625: /*
1.498 dtucker 1626: * If we're not doing an extended test do not silently ignore connection
1627: * test params.
1.358 dtucker 1628: */
1.498 dtucker 1629: if (test_flag < 2 && connection_info != NULL)
1.358 dtucker 1630: fatal("Config test connection parameter (-C) provided without "
1.572 djm 1631: "test mode (-T)");
1.358 dtucker 1632:
1.294 djm 1633: /* Fetch our configuration */
1.511 markus 1634: if ((cfg = sshbuf_new()) == NULL)
1.564 djm 1635: fatal_f("sshbuf_new failed");
1.533 djm 1636: if (rexeced_flag) {
1.560 markus 1637: setproctitle("%s", "[rexeced]");
1.511 markus 1638: recv_rexec_state(REEXEC_CONFIG_PASS_FD, cfg);
1.533 djm 1639: if (!debug_flag) {
1640: startup_pipe = dup(REEXEC_STARTUP_PIPE_FD);
1641: close(REEXEC_STARTUP_PIPE_FD);
1642: /*
1643: * Signal parent that this child is at a point where
1644: * they can go away if they have a SIGHUP pending.
1645: */
1646: (void)atomicio(vwrite, startup_pipe, "\0", 1);
1647: }
1.549 djm 1648: } else if (strcasecmp(config_file_name, "none") != 0)
1.511 markus 1649: load_server_config(config_file_name, cfg);
1.294 djm 1650:
1.337 dtucker 1651: parse_server_config(&options, rexeced_flag ? "rexec" : config_file_name,
1.585 djm 1652: cfg, &includes, NULL, rexeced_flag);
1.571 dtucker 1653:
1.578 dtucker 1654: #ifdef WITH_OPENSSL
1.571 dtucker 1655: if (options.moduli_file != NULL)
1656: dh_set_moduli_file(options.moduli_file);
1.578 dtucker 1657: #endif
1.64 markus 1658:
1659: /* Fill in default values for those options not explicitly set. */
1660: fill_default_server_options(&options);
1.395 djm 1661:
1662: /* Check that options are sensible */
1663: if (options.authorized_keys_command_user == NULL &&
1664: (options.authorized_keys_command != NULL &&
1665: strcasecmp(options.authorized_keys_command, "none") != 0))
1666: fatal("AuthorizedKeysCommand set without "
1667: "AuthorizedKeysCommandUser");
1.449 djm 1668: if (options.authorized_principals_command_user == NULL &&
1669: (options.authorized_principals_command != NULL &&
1670: strcasecmp(options.authorized_principals_command, "none") != 0))
1671: fatal("AuthorizedPrincipalsCommand set without "
1672: "AuthorizedPrincipalsCommandUser");
1.396 djm 1673:
1674: /*
1675: * Check whether there is any path through configured auth methods.
1676: * Unfortunately it is not possible to verify this generally before
1677: * daemonisation in the presence of Match block, but this catches
1678: * and warns for trivial misconfigurations that could break login.
1679: */
1680: if (options.num_auth_methods != 0) {
1.493 djm 1681: for (i = 0; i < options.num_auth_methods; i++) {
1682: if (auth2_methods_valid(options.auth_methods[i],
1.396 djm 1683: 1) == 0)
1684: break;
1685: }
1.493 djm 1686: if (i >= options.num_auth_methods)
1.396 djm 1687: fatal("AuthenticationMethods cannot be satisfied by "
1688: "enabled authentication methods");
1689: }
1.305 djm 1690:
1.64 markus 1691: /* Check that there are no remaining arguments. */
1692: if (optind < ac) {
1693: fprintf(stderr, "Extra argument %s.\n", av[optind]);
1694: exit(1);
1695: }
1696:
1.565 dtucker 1697: debug("sshd version %s, %s", SSH_VERSION, SSH_OPENSSL_VERSION);
1.64 markus 1698:
1.404 markus 1699: /* load host keys */
1.329 djm 1700: sensitive_data.host_keys = xcalloc(options.num_host_key_files,
1.488 markus 1701: sizeof(struct sshkey *));
1.404 markus 1702: sensitive_data.host_pubkeys = xcalloc(options.num_host_key_files,
1.488 markus 1703: sizeof(struct sshkey *));
1.404 markus 1704:
1705: if (options.host_key_agent) {
1706: if (strcmp(options.host_key_agent, SSH_AUTHSOCKET_ENV_NAME))
1707: setenv(SSH_AUTHSOCKET_ENV_NAME,
1708: options.host_key_agent, 1);
1.433 djm 1709: if ((r = ssh_get_authentication_socket(NULL)) == 0)
1710: have_agent = 1;
1711: else
1.564 djm 1712: error_r(r, "Could not connect to agent \"%s\"",
1713: options.host_key_agent);
1.404 markus 1714: }
1.134 markus 1715:
1.217 deraadt 1716: for (i = 0; i < options.num_host_key_files; i++) {
1.519 djm 1717: int ll = options.host_key_file_userprovided[i] ?
1718: SYSLOG_LEVEL_ERROR : SYSLOG_LEVEL_DEBUG1;
1719:
1.430 djm 1720: if (options.host_key_files[i] == NULL)
1721: continue;
1.512 markus 1722: if ((r = sshkey_load_private(options.host_key_files[i], "",
1723: &key, NULL)) != 0 && r != SSH_ERR_SYSTEM_ERROR)
1.564 djm 1724: do_log2_r(r, ll, "Unable to load host key \"%s\"",
1725: options.host_key_files[i]);
1.542 djm 1726: if (sshkey_is_sk(key) &&
1727: key->sk_flags & SSH_SK_USER_PRESENCE_REQD) {
1728: debug("host key %s requires user presence, ignoring",
1729: options.host_key_files[i]);
1730: key->sk_flags &= ~SSH_SK_USER_PRESENCE_REQD;
1731: }
1732: if (r == 0 && key != NULL &&
1733: (r = sshkey_shield_private(key)) != 0) {
1.564 djm 1734: do_log2_r(r, ll, "Unable to shield host key \"%s\"",
1735: options.host_key_files[i]);
1.536 djm 1736: sshkey_free(key);
1737: key = NULL;
1738: }
1.512 markus 1739: if ((r = sshkey_load_public(options.host_key_files[i],
1740: &pubkey, NULL)) != 0 && r != SSH_ERR_SYSTEM_ERROR)
1.564 djm 1741: do_log2_r(r, ll, "Unable to load host key \"%s\"",
1742: options.host_key_files[i]);
1.557 djm 1743: if (pubkey != NULL && key != NULL) {
1744: if (!sshkey_equal(pubkey, key)) {
1745: error("Public key for %s does not match "
1746: "private key", options.host_key_files[i]);
1747: sshkey_free(pubkey);
1748: pubkey = NULL;
1749: }
1750: }
1751: if (pubkey == NULL && key != NULL) {
1.515 djm 1752: if ((r = sshkey_from_private(key, &pubkey)) != 0)
1.564 djm 1753: fatal_r(r, "Could not demote key: \"%s\"",
1754: options.host_key_files[i]);
1.591 djm 1755: }
1756: if (pubkey != NULL && (r = sshkey_check_rsa_length(pubkey,
1757: options.required_rsa_size)) != 0) {
1758: error_fr(r, "Host key %s", options.host_key_files[i]);
1759: sshkey_free(pubkey);
1760: sshkey_free(key);
1761: continue;
1.557 djm 1762: }
1.179 markus 1763: sensitive_data.host_keys[i] = key;
1.404 markus 1764: sensitive_data.host_pubkeys[i] = pubkey;
1765:
1.472 markus 1766: if (key == NULL && pubkey != NULL && have_agent) {
1.443 djm 1767: debug("will rely on agent for hostkey %s",
1768: options.host_key_files[i]);
1.404 markus 1769: keytype = pubkey->type;
1770: } else if (key != NULL) {
1771: keytype = key->type;
1.511 markus 1772: accumulate_host_timing_secret(cfg, key);
1.404 markus 1773: } else {
1.519 djm 1774: do_log2(ll, "Unable to load host key: %s",
1.195 markus 1775: options.host_key_files[i]);
1.179 markus 1776: sensitive_data.host_keys[i] = NULL;
1.404 markus 1777: sensitive_data.host_pubkeys[i] = NULL;
1.134 markus 1778: continue;
1779: }
1.404 markus 1780:
1781: switch (keytype) {
1.134 markus 1782: case KEY_RSA:
1783: case KEY_DSA:
1.378 djm 1784: case KEY_ECDSA:
1.412 markus 1785: case KEY_ED25519:
1.542 djm 1786: case KEY_ECDSA_SK:
1787: case KEY_ED25519_SK:
1.505 markus 1788: case KEY_XMSS:
1.441 djm 1789: if (have_agent || key != NULL)
1790: sensitive_data.have_ssh2_key = 1;
1.134 markus 1791: break;
1792: }
1.441 djm 1793: if ((fp = sshkey_fingerprint(pubkey, options.fingerprint_hash,
1794: SSH_FP_DEFAULT)) == NULL)
1795: fatal("sshkey_fingerprint failed");
1796: debug("%s host key #%d: %s %s",
1.472 markus 1797: key ? "private" : "agent", i, sshkey_ssh_name(pubkey), fp);
1.441 djm 1798: free(fp);
1.134 markus 1799: }
1.511 markus 1800: accumulate_host_timing_secret(cfg, NULL);
1.472 markus 1801: if (!sensitive_data.have_ssh2_key) {
1.264 itojun 1802: logit("sshd: no hostkeys available -- exiting.");
1.64 markus 1803: exit(1);
1804: }
1805:
1.373 djm 1806: /*
1807: * Load certificates. They are stored in an array at identical
1808: * indices to the public keys that they relate to.
1809: */
1810: sensitive_data.host_certificates = xcalloc(options.num_host_key_files,
1.488 markus 1811: sizeof(struct sshkey *));
1.373 djm 1812: for (i = 0; i < options.num_host_key_files; i++)
1813: sensitive_data.host_certificates[i] = NULL;
1814:
1815: for (i = 0; i < options.num_host_cert_files; i++) {
1.430 djm 1816: if (options.host_cert_files[i] == NULL)
1817: continue;
1.512 markus 1818: if ((r = sshkey_load_public(options.host_cert_files[i],
1819: &key, NULL)) != 0) {
1.564 djm 1820: error_r(r, "Could not load host certificate \"%s\"",
1821: options.host_cert_files[i]);
1.373 djm 1822: continue;
1823: }
1.512 markus 1824: if (!sshkey_is_cert(key)) {
1.373 djm 1825: error("Certificate file is not a certificate: %s",
1826: options.host_cert_files[i]);
1.512 markus 1827: sshkey_free(key);
1.373 djm 1828: continue;
1829: }
1830: /* Find matching private key */
1831: for (j = 0; j < options.num_host_key_files; j++) {
1.512 markus 1832: if (sshkey_equal_public(key,
1.575 djm 1833: sensitive_data.host_pubkeys[j])) {
1.373 djm 1834: sensitive_data.host_certificates[j] = key;
1835: break;
1836: }
1837: }
1838: if (j >= options.num_host_key_files) {
1839: error("No matching private key for certificate: %s",
1840: options.host_cert_files[i]);
1.512 markus 1841: sshkey_free(key);
1.373 djm 1842: continue;
1843: }
1844: sensitive_data.host_certificates[j] = key;
1.493 djm 1845: debug("host certificate: #%u type %d %s", j, key->type,
1.512 markus 1846: sshkey_type(key));
1.373 djm 1847: }
1.426 markus 1848:
1.244 markus 1849: if (use_privsep) {
1850: struct stat st;
1851:
1.327 deraadt 1852: if (getpwnam(SSH_PRIVSEP_USER) == NULL)
1.244 markus 1853: fatal("Privilege separation user %s does not exist",
1854: SSH_PRIVSEP_USER);
1.500 djm 1855: endpwent();
1.244 markus 1856: if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) ||
1857: (S_ISDIR(st.st_mode) == 0))
1858: fatal("Missing privilege separation directory: %s",
1.247 stevesk 1859: _PATH_PRIVSEP_CHROOT_DIR);
1860: if (st.st_uid != 0 || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)
1.262 markus 1861: fatal("%s must be owned by root and not group or "
1862: "world-writable.", _PATH_PRIVSEP_CHROOT_DIR);
1.358 dtucker 1863: }
1864:
1865: if (test_flag > 1) {
1.499 djm 1866: /*
1867: * If no connection info was provided by -C then use
1868: * use a blank one that will cause no predicate to match.
1869: */
1870: if (connection_info == NULL)
1.523 djm 1871: connection_info = get_connection_info(ssh, 0, 0);
1.534 dtucker 1872: connection_info->test = 1;
1.546 djm 1873: parse_server_match_config(&options, &includes, connection_info);
1.358 dtucker 1874: dump_config(&options);
1.108 markus 1875: }
1.203 stevesk 1876:
1877: /* Configuration looks good, so exit if in test mode. */
1878: if (test_flag)
1879: exit(0);
1.108 markus 1880:
1.294 djm 1881: if (rexec_flag) {
1.493 djm 1882: if (rexec_argc < 0)
1883: fatal("rexec_argc %d < 0", rexec_argc);
1.329 djm 1884: rexec_argv = xcalloc(rexec_argc + 2, sizeof(char *));
1.493 djm 1885: for (i = 0; i < (u_int)rexec_argc; i++) {
1.294 djm 1886: debug("rexec_argv[%d]='%s'", i, saved_argv[i]);
1887: rexec_argv[i] = saved_argv[i];
1888: }
1889: rexec_argv[rexec_argc] = "-R";
1890: rexec_argv[rexec_argc + 1] = NULL;
1891: }
1.545 djm 1892: listener_proctitle = prepare_proctitle(ac, av);
1.362 dtucker 1893:
1894: /* Ensure that umask disallows at least group and world write */
1895: new_umask = umask(0077) | 0022;
1896: (void) umask(new_umask);
1.294 djm 1897:
1.108 markus 1898: /* Initialize the log (it is reinitialized below in case we forked). */
1.306 dtucker 1899: if (debug_flag && (!inetd_flag || rexeced_flag))
1.64 markus 1900: log_stderr = 1;
1.563 djm 1901: log_init(__progname, options.log_level,
1902: options.log_facility, log_stderr);
1903: for (i = 0; i < options.num_log_verbose; i++)
1904: log_verbose_add(options.log_verbose[i]);
1.64 markus 1905:
1.108 markus 1906: /*
1.478 dtucker 1907: * If not in debugging mode, not started from inetd and not already
1908: * daemonized (eg re-exec via SIGHUP), disconnect from the controlling
1909: * terminal, and fork. The original process exits.
1.108 markus 1910: */
1.478 dtucker 1911: already_daemon = daemonized();
1912: if (!(debug_flag || inetd_flag || no_daemon_flag || already_daemon)) {
1.345 djm 1913:
1.537 deraadt 1914: if (daemon(0, 0) == -1)
1.64 markus 1915: fatal("daemon() failed: %.200s", strerror(errno));
1916:
1.477 dtucker 1917: disconnect_controlling_tty();
1.64 markus 1918: }
1919: /* Reinitialize the log (because of the fork above). */
1.138 markus 1920: log_init(__progname, options.log_level, options.log_facility, log_stderr);
1.64 markus 1921:
1.572 djm 1922: /*
1923: * Chdir to the root directory so that the current disk can be
1924: * unmounted if desired.
1925: */
1.401 dtucker 1926: if (chdir("/") == -1)
1927: error("chdir(\"/\"): %s", strerror(errno));
1.217 deraadt 1928:
1.178 markus 1929: /* ignore SIGPIPE */
1.544 dtucker 1930: ssh_signal(SIGPIPE, SIG_IGN);
1.64 markus 1931:
1.345 djm 1932: /* Get a connection, either from inetd or a listening TCP socket */
1.64 markus 1933: if (inetd_flag) {
1.345 djm 1934: server_accept_inetd(&sock_in, &sock_out);
1.64 markus 1935: } else {
1.345 djm 1936: server_listen();
1.75 markus 1937:
1.544 dtucker 1938: ssh_signal(SIGHUP, sighup_handler);
1939: ssh_signal(SIGCHLD, main_sigchld_handler);
1940: ssh_signal(SIGTERM, sigterm_handler);
1941: ssh_signal(SIGQUIT, sigterm_handler);
1.201 markus 1942:
1.345 djm 1943: /*
1944: * Write out the pid file after the sigterm handler
1945: * is setup and the listen sockets are bound
1946: */
1.479 dtucker 1947: if (options.pid_file != NULL && !debug_flag) {
1.345 djm 1948: FILE *f = fopen(options.pid_file, "w");
1.201 markus 1949:
1.270 djm 1950: if (f == NULL) {
1951: error("Couldn't create pid file \"%s\": %s",
1952: options.pid_file, strerror(errno));
1953: } else {
1.245 mpech 1954: fprintf(f, "%ld\n", (long) getpid());
1.64 markus 1955: fclose(f);
1956: }
1957: }
1958:
1.345 djm 1959: /* Accept a connection and return in a forked child */
1960: server_accept_loop(&sock_in, &sock_out,
1961: &newsock, config_s);
1.1 deraadt 1962: }
1963:
1.64 markus 1964: /* This is the child processing a new connection. */
1.288 markus 1965: setproctitle("%s", "[accepted]");
1.294 djm 1966:
1.300 markus 1967: /*
1968: * Create a new session and process group since the 4.4BSD
1969: * setlogin() affects the entire process group. We don't
1970: * want the child to be able to affect the parent.
1971: */
1.537 deraadt 1972: if (!debug_flag && !inetd_flag && setsid() == -1)
1.300 markus 1973: error("setsid: %.100s", strerror(errno));
1974:
1.294 djm 1975: if (rexec_flag) {
1.296 djm 1976: debug("rexec start in %d out %d newsock %d pipe %d sock %d",
1977: sock_in, sock_out, newsock, startup_pipe, config_s[0]);
1.294 djm 1978: dup2(newsock, STDIN_FILENO);
1979: dup2(STDIN_FILENO, STDOUT_FILENO);
1980: if (startup_pipe == -1)
1.296 djm 1981: close(REEXEC_STARTUP_PIPE_FD);
1.407 djm 1982: else if (startup_pipe != REEXEC_STARTUP_PIPE_FD) {
1.296 djm 1983: dup2(startup_pipe, REEXEC_STARTUP_PIPE_FD);
1.407 djm 1984: close(startup_pipe);
1985: startup_pipe = REEXEC_STARTUP_PIPE_FD;
1986: }
1.294 djm 1987:
1.296 djm 1988: dup2(config_s[1], REEXEC_CONFIG_PASS_FD);
1.294 djm 1989: close(config_s[1]);
1.296 djm 1990:
1.559 markus 1991: ssh_signal(SIGHUP, SIG_IGN); /* avoid reset to SIG_DFL */
1.294 djm 1992: execv(rexec_argv[0], rexec_argv);
1993:
1994: /* Reexec has failed, fall back and continue */
1995: error("rexec of %s failed: %s", rexec_argv[0], strerror(errno));
1.296 djm 1996: recv_rexec_state(REEXEC_CONFIG_PASS_FD, NULL);
1.294 djm 1997: log_init(__progname, options.log_level,
1998: options.log_facility, log_stderr);
1999:
2000: /* Clean up fds */
1.296 djm 2001: close(REEXEC_CONFIG_PASS_FD);
2002: newsock = sock_out = sock_in = dup(STDIN_FILENO);
1.562 djm 2003: if (stdfd_devnull(1, 1, 0) == -1)
1.564 djm 2004: error_f("stdfd_devnull failed");
1.296 djm 2005: debug("rexec cleanup in %d out %d newsock %d pipe %d sock %d",
2006: sock_in, sock_out, newsock, startup_pipe, config_s[0]);
1.294 djm 2007: }
1.372 djm 2008:
2009: /* Executed child processes don't need these. */
2010: fcntl(sock_out, F_SETFD, FD_CLOEXEC);
2011: fcntl(sock_in, F_SETFD, FD_CLOEXEC);
1.64 markus 2012:
1.551 dtucker 2013: /* We will not restart on SIGHUP since it no longer makes sense. */
1.544 dtucker 2014: ssh_signal(SIGALRM, SIG_DFL);
2015: ssh_signal(SIGHUP, SIG_DFL);
2016: ssh_signal(SIGTERM, SIG_DFL);
2017: ssh_signal(SIGQUIT, SIG_DFL);
2018: ssh_signal(SIGCHLD, SIG_DFL);
1.150 markus 2019:
1.66 markus 2020: /*
2021: * Register our connection. This turns encryption off because we do
2022: * not have a key.
2023: */
1.525 djm 2024: if ((ssh = ssh_packet_set_connection(NULL, sock_in, sock_out)) == NULL)
2025: fatal("Unable to create connection");
1.527 djm 2026: the_active_state = ssh;
1.525 djm 2027: ssh_packet_set_server(ssh);
1.492 djm 2028:
1.466 djm 2029: check_ip_options(ssh);
1.309 djm 2030:
1.492 djm 2031: /* Prepare the channels layer */
2032: channel_init_channels(ssh);
2033: channel_set_af(ssh, options.address_family);
1.595 djm 2034: process_channel_timeouts(ssh, &options);
1.492 djm 2035: process_permitopen(ssh, &options);
2036:
1.309 djm 2037: /* Set SO_KEEPALIVE if requested. */
1.525 djm 2038: if (options.tcp_keep_alive && ssh_packet_connection_is_on_socket(ssh) &&
1.537 deraadt 2039: setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) == -1)
1.309 djm 2040: error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1.1 deraadt 2041:
1.466 djm 2042: if ((remote_port = ssh_remote_port(ssh)) < 0) {
2043: debug("ssh_remote_port failed");
1.310 markus 2044: cleanup_exit(255);
2045: }
1.316 dtucker 2046:
2047: /*
1.331 markus 2048: * The rest of the code depends on the fact that
1.466 djm 2049: * ssh_remote_ipaddr() caches the remote ip, even if
1.331 markus 2050: * the socket goes away.
2051: */
1.466 djm 2052: remote_ip = ssh_remote_ipaddr(ssh);
1.209 markus 2053:
1.496 djm 2054: rdomain = ssh_packet_rdomain_in(ssh);
2055:
1.64 markus 2056: /* Log the connection. */
1.447 dtucker 2057: laddr = get_local_ipaddr(sock_in);
1.497 djm 2058: verbose("Connection from %s port %d on %s port %d%s%s%s",
1.496 djm 2059: remote_ip, remote_port, laddr, ssh_local_port(ssh),
1.497 djm 2060: rdomain == NULL ? "" : " rdomain \"",
2061: rdomain == NULL ? "" : rdomain,
2062: rdomain == NULL ? "" : "\"");
1.447 dtucker 2063: free(laddr);
1.1 deraadt 2064:
1.66 markus 2065: /*
1.317 djm 2066: * We don't want to listen forever unless the other side
1.66 markus 2067: * successfully authenticates itself. So we set up an alarm which is
2068: * cleared after successful authentication. A limit of zero
1.317 djm 2069: * indicates no limit. Note that we don't set the alarm in debugging
1.66 markus 2070: * mode; it is just annoying to have the server exit just when you
2071: * are about to discover the bug.
2072: */
1.544 dtucker 2073: ssh_signal(SIGALRM, grace_alarm_handler);
1.64 markus 2074: if (!debug_flag)
2075: alarm(options.login_grace_time);
2076:
1.552 djm 2077: if ((r = kex_exchange_identification(ssh, -1,
2078: options.version_addendum)) != 0)
2079: sshpkt_fatal(ssh, r, "banner exchange");
1.520 djm 2080:
1.525 djm 2081: ssh_packet_set_nonblocking(ssh);
1.1 deraadt 2082:
1.278 markus 2083: /* allocate authentication context */
1.329 djm 2084: authctxt = xcalloc(1, sizeof(*authctxt));
1.525 djm 2085: ssh->authctxt = authctxt;
1.278 markus 2086:
2087: /* XXX global for cleanup, access from other modules */
2088: the_authctxt = authctxt;
1.506 djm 2089:
2090: /* Set default key authentication options */
2091: if ((auth_opts = sshauthopt_new_with_keys_defaults()) == NULL)
2092: fatal("allocation failed");
1.278 markus 2093:
1.307 otto 2094: /* prepare buffer to collect messages to display to user after login */
1.510 markus 2095: if ((loginmsg = sshbuf_new()) == NULL)
1.564 djm 2096: fatal_f("sshbuf_new failed");
1.374 dtucker 2097: auth_debug_reset();
1.307 otto 2098:
1.404 markus 2099: if (use_privsep) {
1.525 djm 2100: if (privsep_preauth(ssh) == 1)
1.237 markus 2101: goto authenticated;
1.472 markus 2102: } else if (have_agent) {
1.432 djm 2103: if ((r = ssh_get_authentication_socket(&auth_sock)) != 0) {
1.564 djm 2104: error_r(r, "Unable to get agent socket");
1.433 djm 2105: have_agent = 0;
1.432 djm 2106: }
2107: }
1.231 provos 2108:
1.77 markus 2109: /* perform the key exchange */
2110: /* authenticate user and start session */
1.525 djm 2111: do_ssh2_kex(ssh);
1.524 djm 2112: do_authentication2(ssh);
1.472 markus 2113:
1.237 markus 2114: /*
2115: * If we use privilege separation, the unprivileged child transfers
2116: * the current keystate and exits
2117: */
2118: if (use_privsep) {
1.527 djm 2119: mm_send_keystate(ssh, pmonitor);
1.525 djm 2120: ssh_packet_clear_keys(ssh);
1.231 provos 2121: exit(0);
1.237 markus 2122: }
1.231 provos 2123:
2124: authenticated:
1.318 djm 2125: /*
2126: * Cancel the alarm we set to limit the time taken for
2127: * authentication.
2128: */
2129: alarm(0);
1.544 dtucker 2130: ssh_signal(SIGALRM, SIG_DFL);
1.347 markus 2131: authctxt->authenticated = 1;
1.318 djm 2132: if (startup_pipe != -1) {
2133: close(startup_pipe);
2134: startup_pipe = -1;
2135: }
1.495 djm 2136:
2137: if (options.routing_domain != NULL)
2138: set_process_rdomain(ssh, options.routing_domain);
1.318 djm 2139:
1.234 markus 2140: /*
1.231 provos 2141: * In privilege separation, we fork another child and prepare
2142: * file descriptor passing.
2143: */
2144: if (use_privsep) {
1.525 djm 2145: privsep_postauth(ssh, authctxt);
1.237 markus 2146: /* the monitor process [priv] will not return */
1.231 provos 2147: }
1.360 dtucker 2148:
1.525 djm 2149: ssh_packet_set_timeout(ssh, options.client_alive_interval,
1.360 dtucker 2150: options.client_alive_count_max);
1.439 djm 2151:
2152: /* Try to send all our hostkeys to the client */
1.492 djm 2153: notify_hostkeys(ssh);
1.230 provos 2154:
1.278 markus 2155: /* Start session. */
1.492 djm 2156: do_authenticated(ssh, authctxt);
1.230 provos 2157:
1.64 markus 2158: /* The connection has been terminated. */
1.525 djm 2159: ssh_packet_get_bytes(ssh, &ibytes, &obytes);
1.381 djm 2160: verbose("Transferred: sent %llu, received %llu bytes",
2161: (unsigned long long)obytes, (unsigned long long)ibytes);
1.364 markus 2162:
2163: verbose("Closing connection to %.500s port %d", remote_ip, remote_port);
1.525 djm 2164: ssh_packet_close(ssh);
1.231 provos 2165:
2166: if (use_privsep)
2167: mm_terminate();
2168:
1.64 markus 2169: exit(0);
1.1 deraadt 2170: }
1.98 markus 2171:
1.435 markus 2172: int
1.527 djm 2173: sshd_hostkey_sign(struct ssh *ssh, struct sshkey *privkey,
2174: struct sshkey *pubkey, u_char **signature, size_t *slenp,
2175: const u_char *data, size_t dlen, const char *alg)
1.404 markus 2176: {
1.432 djm 2177: int r;
2178:
1.527 djm 2179: if (use_privsep) {
2180: if (privkey) {
2181: if (mm_sshkey_sign(ssh, privkey, signature, slenp,
1.561 djm 2182: data, dlen, alg, options.sk_provider, NULL,
1.542 djm 2183: ssh->compat) < 0)
1.564 djm 2184: fatal_f("privkey sign failed");
1.527 djm 2185: } else {
2186: if (mm_sshkey_sign(ssh, pubkey, signature, slenp,
1.561 djm 2187: data, dlen, alg, options.sk_provider, NULL,
1.542 djm 2188: ssh->compat) < 0)
1.564 djm 2189: fatal_f("pubkey sign failed");
1.527 djm 2190: }
1.404 markus 2191: } else {
1.527 djm 2192: if (privkey) {
2193: if (sshkey_sign(privkey, signature, slenp, data, dlen,
1.561 djm 2194: alg, options.sk_provider, NULL, ssh->compat) < 0)
1.564 djm 2195: fatal_f("privkey sign failed");
1.527 djm 2196: } else {
2197: if ((r = ssh_agent_sign(auth_sock, pubkey,
2198: signature, slenp, data, dlen, alg,
2199: ssh->compat)) != 0) {
1.564 djm 2200: fatal_fr(r, "agent sign failed");
1.527 djm 2201: }
2202: }
1.404 markus 2203: }
1.435 markus 2204: return 0;
1.404 markus 2205: }
2206:
1.452 djm 2207: /* SSH2 key exchange */
1.200 itojun 2208: static void
1.525 djm 2209: do_ssh2_kex(struct ssh *ssh)
1.98 markus 2210: {
1.422 markus 2211: char *myproposal[PROPOSAL_MAX] = { KEX_SERVER };
1.435 markus 2212: struct kex *kex;
1.589 dtucker 2213: char *prop_kex = NULL, *prop_enc = NULL, *prop_hostkey = NULL;
1.437 markus 2214: int r;
1.102 markus 2215:
1.589 dtucker 2216: myproposal[PROPOSAL_KEX_ALGS] = prop_kex = compat_kex_proposal(ssh,
1.514 djm 2217: options.kex_algorithms);
1.589 dtucker 2218: myproposal[PROPOSAL_ENC_ALGS_CTOS] =
2219: myproposal[PROPOSAL_ENC_ALGS_STOC] = prop_enc =
2220: compat_cipher_proposal(ssh, options.ciphers);
1.457 djm 2221: myproposal[PROPOSAL_MAC_ALGS_CTOS] =
2222: myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
2223:
1.312 markus 2224: if (options.compression == COMP_NONE) {
1.246 markus 2225: myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1.470 dtucker 2226: myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
1.102 markus 2227: }
1.400 dtucker 2228:
2229: if (options.rekey_limit || options.rekey_interval)
1.525 djm 2230: ssh_packet_set_rekey_limits(ssh, options.rekey_limit,
1.481 dtucker 2231: options.rekey_interval);
1.327 deraadt 2232:
1.589 dtucker 2233: myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = prop_hostkey =
2234: compat_pkalg_proposal(ssh, list_hostkey_types());
1.134 markus 2235:
1.189 markus 2236: /* start key exchange */
1.525 djm 2237: if ((r = kex_setup(ssh, myproposal)) != 0)
1.564 djm 2238: fatal_r(r, "kex_setup");
1.525 djm 2239: kex = ssh->kex;
1.426 markus 2240: #ifdef WITH_OPENSSL
1.532 djm 2241: kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_server;
2242: kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_server;
2243: kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_server;
2244: kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_server;
2245: kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_server;
1.263 markus 2246: kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1.324 djm 2247: kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1.532 djm 2248: kex->kex[KEX_ECDH_SHA2] = kex_gen_server;
1.426 markus 2249: #endif
1.532 djm 2250: kex->kex[KEX_C25519_SHA256] = kex_gen_server;
1.566 djm 2251: kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_server;
1.373 djm 2252: kex->load_host_public_key=&get_hostkey_public_by_type;
2253: kex->load_host_private_key=&get_hostkey_private_by_type;
1.231 provos 2254: kex->host_key_index=&get_hostkey_index;
1.404 markus 2255: kex->sign = sshd_hostkey_sign;
1.189 markus 2256:
1.525 djm 2257: ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &kex->done);
1.129 provos 2258:
2259: #ifdef DEBUG_KEXDH
2260: /* send 1st encrypted/maced/compressed message */
1.553 djm 2261: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2262: (r = sshpkt_put_cstring(ssh, "markus")) != 0 ||
2263: (r = sshpkt_send(ssh)) != 0 ||
2264: (r = ssh_packet_write_wait(ssh)) != 0)
1.564 djm 2265: fatal_fr(r, "send test");
1.129 provos 2266: #endif
1.589 dtucker 2267: free(prop_kex);
2268: free(prop_enc);
2269: free(prop_hostkey);
1.186 markus 2270: debug("KEX done");
1.278 markus 2271: }
2272:
2273: /* server specific fatal cleanup */
2274: void
2275: cleanup_exit(int i)
2276: {
1.527 djm 2277: if (the_active_state != NULL && the_authctxt != NULL) {
2278: do_cleanup(the_active_state, the_authctxt);
1.423 djm 2279: if (use_privsep && privsep_is_preauth &&
2280: pmonitor != NULL && pmonitor->m_pid > 1) {
1.386 djm 2281: debug("Killing privsep child %d", pmonitor->m_pid);
2282: if (kill(pmonitor->m_pid, SIGKILL) != 0 &&
1.564 djm 2283: errno != ESRCH) {
2284: error_f("kill(%d): %s", pmonitor->m_pid,
2285: strerror(errno));
2286: }
1.386 djm 2287: }
2288: }
1.278 markus 2289: _exit(i);
1.1 deraadt 2290: }
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