Annotation of src/usr.bin/ssh/sshd.c, Revision 1.599
1.599 ! dtucker 1: /* $OpenBSD: sshd.c,v 1.598 2023/03/03 03:12:24 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:
273: /*ARGSUSED*/
1.200 itojun 274: static void
1.64 markus 275: sighup_handler(int sig)
1.1 deraadt 276: {
1.64 markus 277: received_sighup = 1;
1.1 deraadt 278: }
279:
1.65 deraadt 280: /*
281: * Called from the main program after receiving SIGHUP.
282: * Restarts the server.
283: */
1.200 itojun 284: static void
1.165 itojun 285: sighup_restart(void)
1.1 deraadt 286: {
1.264 itojun 287: logit("Received SIGHUP; restarting.");
1.479 dtucker 288: if (options.pid_file != NULL)
289: unlink(options.pid_file);
1.75 markus 290: close_listen_socks();
1.211 markus 291: close_startup_pipes();
1.544 dtucker 292: ssh_signal(SIGHUP, SIG_IGN); /* will be restored after exec */
1.64 markus 293: execv(saved_argv[0], saved_argv);
1.264 itojun 294: logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0],
1.250 deraadt 295: strerror(errno));
1.64 markus 296: exit(1);
1.1 deraadt 297: }
298:
1.65 deraadt 299: /*
300: * Generic signal handler for terminating signals in the master daemon.
301: */
1.327 deraadt 302: /*ARGSUSED*/
1.200 itojun 303: static void
1.64 markus 304: sigterm_handler(int sig)
1.1 deraadt 305: {
1.199 markus 306: received_sigterm = sig;
1.1 deraadt 307: }
308:
1.65 deraadt 309: /*
310: * SIGCHLD handler. This is called whenever a child dies. This will then
1.199 markus 311: * reap any zombies left by exited children.
1.65 deraadt 312: */
1.327 deraadt 313: /*ARGSUSED*/
1.200 itojun 314: static void
1.64 markus 315: main_sigchld_handler(int sig)
1.1 deraadt 316: {
1.250 deraadt 317: int save_errno = errno;
1.239 markus 318: pid_t pid;
1.64 markus 319: int status;
1.544 dtucker 320:
1.239 markus 321: while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
1.537 deraadt 322: (pid == -1 && errno == EINTR))
1.64 markus 323: ;
324: errno = save_errno;
1.1 deraadt 325: }
326:
1.65 deraadt 327: /*
328: * Signal handler for the alarm after the login grace period has expired.
329: */
1.327 deraadt 330: /*ARGSUSED*/
1.200 itojun 331: static void
1.64 markus 332: grace_alarm_handler(int sig)
1.1 deraadt 333: {
1.394 djm 334: /*
335: * Try to kill any processes that we have spawned, E.g. authorized
1.583 dtucker 336: * keys command helpers or privsep children.
1.394 djm 337: */
338: if (getpgid(0) == getpid()) {
1.544 dtucker 339: ssh_signal(SIGTERM, SIG_IGN);
1.416 djm 340: kill(0, SIGTERM);
1.394 djm 341: }
1.285 dtucker 342:
1.64 markus 343: /* Log error and exit. */
1.583 dtucker 344: sigdie("Timeout before authentication for %s port %d",
345: ssh_remote_ipaddr(the_active_state),
346: ssh_remote_port(the_active_state));
1.62 markus 347: }
348:
1.134 markus 349: /* Destroy the host and server keys. They will no longer be needed. */
1.108 markus 350: void
351: destroy_sensitive_data(void)
352: {
1.493 djm 353: u_int i;
1.134 markus 354:
1.217 deraadt 355: for (i = 0; i < options.num_host_key_files; i++) {
1.134 markus 356: if (sensitive_data.host_keys[i]) {
1.512 markus 357: sshkey_free(sensitive_data.host_keys[i]);
1.134 markus 358: sensitive_data.host_keys[i] = NULL;
359: }
1.373 djm 360: if (sensitive_data.host_certificates[i]) {
1.512 markus 361: sshkey_free(sensitive_data.host_certificates[i]);
1.373 djm 362: sensitive_data.host_certificates[i] = NULL;
363: }
1.134 markus 364: }
365: }
366:
1.231 provos 367: /* Demote private to public keys for network child */
368: void
369: demote_sensitive_data(void)
370: {
1.488 markus 371: struct sshkey *tmp;
1.493 djm 372: u_int i;
1.512 markus 373: int r;
1.231 provos 374:
375: for (i = 0; i < options.num_host_key_files; i++) {
376: if (sensitive_data.host_keys[i]) {
1.515 djm 377: if ((r = sshkey_from_private(
378: sensitive_data.host_keys[i], &tmp)) != 0)
1.564 djm 379: fatal_r(r, "could not demote host %s key",
380: sshkey_type(sensitive_data.host_keys[i]));
1.512 markus 381: sshkey_free(sensitive_data.host_keys[i]);
1.231 provos 382: sensitive_data.host_keys[i] = tmp;
383: }
1.373 djm 384: /* Certs do not need demotion */
1.231 provos 385: }
386: }
387:
1.233 markus 388: static void
1.231 provos 389: privsep_preauth_child(void)
390: {
1.253 deraadt 391: gid_t gidset[1];
1.250 deraadt 392: struct passwd *pw;
1.231 provos 393:
394: /* Enable challenge-response authentication for privilege separation */
395: privsep_challenge_enable();
1.419 djm 396:
1.420 markus 397: #ifdef GSSAPI
1.419 djm 398: /* Cache supported mechanism OIDs for later use */
1.516 djm 399: ssh_gssapi_prepare_supported_oids();
1.420 markus 400: #endif
1.231 provos 401:
402: /* Demote the private keys to public keys. */
403: demote_sensitive_data();
404:
1.460 djm 405: /* Demote the child */
406: if (getuid() == 0 || geteuid() == 0) {
407: if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
408: fatal("Privilege separation user %s does not exist",
409: SSH_PRIVSEP_USER);
1.500 djm 410: pw = pwcopy(pw); /* Ensure mutable */
1.460 djm 411: endpwent();
1.500 djm 412: freezero(pw->pw_passwd, strlen(pw->pw_passwd));
1.460 djm 413:
414: /* Change our root directory */
415: if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1)
416: fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR,
417: strerror(errno));
418: if (chdir("/") == -1)
419: fatal("chdir(\"/\"): %s", strerror(errno));
420:
421: /*
422: * Drop our privileges
423: * NB. Can't use setusercontext() after chroot.
424: */
425: debug3("privsep user:group %u:%u", (u_int)pw->pw_uid,
426: (u_int)pw->pw_gid);
427: gidset[0] = pw->pw_gid;
1.537 deraadt 428: if (setgroups(1, gidset) == -1)
1.460 djm 429: fatal("setgroups: %.100s", strerror(errno));
430: permanently_set_uid(pw);
431: }
1.231 provos 432: }
433:
1.278 markus 434: static int
1.525 djm 435: privsep_preauth(struct ssh *ssh)
1.237 markus 436: {
1.432 djm 437: int status, r;
1.237 markus 438: pid_t pid;
1.384 djm 439: struct ssh_sandbox *box = NULL;
1.237 markus 440:
441: /* Set up unprivileged child process to deal with network data */
1.242 mouring 442: pmonitor = monitor_init();
1.237 markus 443: /* Store a pointer to the kex for later rekeying */
1.525 djm 444: pmonitor->m_pkex = &ssh->kex;
1.237 markus 445:
1.393 djm 446: if (use_privsep == PRIVSEP_ON)
1.384 djm 447: box = ssh_sandbox_init();
1.237 markus 448: pid = fork();
449: if (pid == -1) {
450: fatal("fork of unprivileged child failed");
451: } else if (pid != 0) {
1.245 mpech 452: debug2("Network child is on pid %ld", (long)pid);
1.237 markus 453:
1.392 markus 454: pmonitor->m_pid = pid;
1.432 djm 455: if (have_agent) {
456: r = ssh_get_authentication_socket(&auth_sock);
457: if (r != 0) {
1.564 djm 458: error_r(r, "Could not get agent socket");
1.432 djm 459: have_agent = 0;
460: }
461: }
1.384 djm 462: if (box != NULL)
463: ssh_sandbox_parent_preauth(box, pid);
1.526 djm 464: monitor_child_preauth(ssh, pmonitor);
1.237 markus 465:
466: /* Wait for the child's exit status */
1.537 deraadt 467: while (waitpid(pid, &status, 0) == -1) {
1.386 djm 468: if (errno == EINTR)
469: continue;
470: pmonitor->m_pid = -1;
1.564 djm 471: fatal_f("waitpid: %s", strerror(errno));
1.384 djm 472: }
1.386 djm 473: privsep_is_preauth = 0;
474: pmonitor->m_pid = -1;
1.384 djm 475: if (WIFEXITED(status)) {
476: if (WEXITSTATUS(status) != 0)
1.564 djm 477: fatal_f("preauth child exited with status %d",
478: WEXITSTATUS(status));
1.384 djm 479: } else if (WIFSIGNALED(status))
1.564 djm 480: fatal_f("preauth child terminated by signal %d",
481: WTERMSIG(status));
1.384 djm 482: if (box != NULL)
483: ssh_sandbox_parent_finish(box);
484: return 1;
1.237 markus 485: } else {
486: /* child */
1.383 djm 487: close(pmonitor->m_sendfd);
488: close(pmonitor->m_log_recvfd);
1.237 markus 489:
1.383 djm 490: /* Arrange for logging to be sent to the monitor */
491: set_log_handler(mm_log_handler, pmonitor);
1.237 markus 492:
1.460 djm 493: privsep_preauth_child();
1.238 stevesk 494: setproctitle("%s", "[net]");
1.384 djm 495: if (box != NULL)
496: ssh_sandbox_child(box);
497:
498: return 0;
1.237 markus 499: }
500: }
501:
1.233 markus 502: static void
1.525 djm 503: privsep_postauth(struct ssh *ssh, Authctxt *authctxt)
1.231 provos 504: {
1.474 djm 505: if (authctxt->pw->pw_uid == 0) {
1.231 provos 506: /* File descriptor passing is broken or root login */
507: use_privsep = 0;
1.315 djm 508: goto skip;
1.231 provos 509: }
1.234 markus 510:
1.231 provos 511: /* New socket pair */
1.242 mouring 512: monitor_reinit(pmonitor);
1.231 provos 513:
1.242 mouring 514: pmonitor->m_pid = fork();
515: if (pmonitor->m_pid == -1)
1.231 provos 516: fatal("fork of unprivileged child failed");
1.242 mouring 517: else if (pmonitor->m_pid != 0) {
1.364 markus 518: verbose("User child is on pid %ld", (long)pmonitor->m_pid);
1.510 markus 519: sshbuf_reset(loginmsg);
1.526 djm 520: monitor_clear_keystate(ssh, pmonitor);
521: monitor_child_postauth(ssh, pmonitor);
1.231 provos 522:
523: /* NEVERREACHED */
524: exit(0);
525: }
526:
1.383 djm 527: /* child */
528:
1.242 mouring 529: close(pmonitor->m_sendfd);
1.383 djm 530: pmonitor->m_sendfd = -1;
1.231 provos 531:
532: /* Demote the private keys to public keys. */
533: demote_sensitive_data();
1.354 djm 534:
1.231 provos 535: /* Drop privileges */
536: do_setusercontext(authctxt->pw);
537:
1.315 djm 538: skip:
1.231 provos 539: /* It is safe now to apply the key state */
1.526 djm 540: monitor_apply_keystate(ssh, pmonitor);
1.312 markus 541:
542: /*
543: * Tell the packet layer that authentication was successful, since
544: * this information is not part of the key state.
545: */
1.525 djm 546: ssh_packet_set_authenticated(ssh);
1.231 provos 547: }
548:
1.509 djm 549: static void
550: append_hostkey_type(struct sshbuf *b, const char *s)
551: {
552: int r;
553:
554: if (match_pattern_list(s, options.hostkeyalgorithms, 0) != 1) {
1.564 djm 555: debug3_f("%s key not permitted by HostkeyAlgorithms", s);
1.509 djm 556: return;
557: }
558: if ((r = sshbuf_putf(b, "%s%s", sshbuf_len(b) > 0 ? "," : "", s)) != 0)
1.564 djm 559: fatal_fr(r, "sshbuf_putf");
1.509 djm 560: }
561:
1.200 itojun 562: static char *
1.134 markus 563: list_hostkey_types(void)
564: {
1.509 djm 565: struct sshbuf *b;
566: struct sshkey *key;
1.281 jakob 567: char *ret;
1.493 djm 568: u_int i;
1.223 markus 569:
1.509 djm 570: if ((b = sshbuf_new()) == NULL)
1.564 djm 571: fatal_f("sshbuf_new failed");
1.217 deraadt 572: for (i = 0; i < options.num_host_key_files; i++) {
1.373 djm 573: key = sensitive_data.host_keys[i];
1.443 djm 574: if (key == NULL)
1.404 markus 575: key = sensitive_data.host_pubkeys[i];
1.472 markus 576: if (key == NULL)
1.134 markus 577: continue;
1.214 deraadt 578: switch (key->type) {
1.134 markus 579: case KEY_RSA:
1.509 djm 580: /* for RSA we also support SHA2 signatures */
581: append_hostkey_type(b, "rsa-sha2-512");
582: append_hostkey_type(b, "rsa-sha2-256");
583: /* FALLTHROUGH */
1.134 markus 584: case KEY_DSA:
1.378 djm 585: case KEY_ECDSA:
1.412 markus 586: case KEY_ED25519:
1.542 djm 587: case KEY_ECDSA_SK:
588: case KEY_ED25519_SK:
1.505 markus 589: case KEY_XMSS:
1.509 djm 590: append_hostkey_type(b, sshkey_ssh_name(key));
1.134 markus 591: break;
592: }
1.373 djm 593: /* If the private key has a cert peer, then list that too */
594: key = sensitive_data.host_certificates[i];
595: if (key == NULL)
596: continue;
597: switch (key->type) {
598: case KEY_RSA_CERT:
1.509 djm 599: /* for RSA we also support SHA2 signatures */
600: append_hostkey_type(b,
601: "rsa-sha2-512-cert-v01@openssh.com");
602: append_hostkey_type(b,
603: "rsa-sha2-256-cert-v01@openssh.com");
604: /* FALLTHROUGH */
1.373 djm 605: case KEY_DSA_CERT:
1.378 djm 606: case KEY_ECDSA_CERT:
1.412 markus 607: case KEY_ED25519_CERT:
1.542 djm 608: case KEY_ECDSA_SK_CERT:
609: case KEY_ED25519_SK_CERT:
1.505 markus 610: case KEY_XMSS_CERT:
1.509 djm 611: append_hostkey_type(b, sshkey_ssh_name(key));
1.373 djm 612: break;
613: }
1.134 markus 614: }
1.509 djm 615: if ((ret = sshbuf_dup_string(b)) == NULL)
1.564 djm 616: fatal_f("sshbuf_dup_string failed");
1.509 djm 617: sshbuf_free(b);
1.564 djm 618: debug_f("%s", ret);
1.281 jakob 619: return ret;
1.134 markus 620: }
621:
1.488 markus 622: static struct sshkey *
1.440 djm 623: get_hostkey_by_type(int type, int nid, int need_private, struct ssh *ssh)
1.134 markus 624: {
1.493 djm 625: u_int i;
1.488 markus 626: struct sshkey *key;
1.250 deraadt 627:
1.217 deraadt 628: for (i = 0; i < options.num_host_key_files; i++) {
1.375 djm 629: switch (type) {
630: case KEY_RSA_CERT:
631: case KEY_DSA_CERT:
1.378 djm 632: case KEY_ECDSA_CERT:
1.412 markus 633: case KEY_ED25519_CERT:
1.542 djm 634: case KEY_ECDSA_SK_CERT:
635: case KEY_ED25519_SK_CERT:
1.505 markus 636: case KEY_XMSS_CERT:
1.373 djm 637: key = sensitive_data.host_certificates[i];
1.375 djm 638: break;
639: default:
1.373 djm 640: key = sensitive_data.host_keys[i];
1.404 markus 641: if (key == NULL && !need_private)
642: key = sensitive_data.host_pubkeys[i];
1.375 djm 643: break;
644: }
1.542 djm 645: if (key == NULL || key->type != type)
646: continue;
647: switch (type) {
648: case KEY_ECDSA:
649: case KEY_ECDSA_SK:
650: case KEY_ECDSA_CERT:
651: case KEY_ECDSA_SK_CERT:
652: if (key->ecdsa_nid != nid)
653: continue;
654: /* FALLTHROUGH */
655: default:
1.373 djm 656: return need_private ?
657: sensitive_data.host_keys[i] : key;
1.542 djm 658: }
1.134 markus 659: }
660: return NULL;
1.96 markus 661: }
662:
1.488 markus 663: struct sshkey *
1.440 djm 664: get_hostkey_public_by_type(int type, int nid, struct ssh *ssh)
1.373 djm 665: {
1.440 djm 666: return get_hostkey_by_type(type, nid, 0, ssh);
1.373 djm 667: }
668:
1.488 markus 669: struct sshkey *
1.440 djm 670: get_hostkey_private_by_type(int type, int nid, struct ssh *ssh)
1.373 djm 671: {
1.440 djm 672: return get_hostkey_by_type(type, nid, 1, ssh);
1.373 djm 673: }
674:
1.488 markus 675: struct sshkey *
1.231 provos 676: get_hostkey_by_index(int ind)
677: {
1.493 djm 678: if (ind < 0 || (u_int)ind >= options.num_host_key_files)
1.231 provos 679: return (NULL);
680: return (sensitive_data.host_keys[ind]);
681: }
682:
1.488 markus 683: struct sshkey *
1.435 markus 684: get_hostkey_public_by_index(int ind, struct ssh *ssh)
1.404 markus 685: {
1.493 djm 686: if (ind < 0 || (u_int)ind >= options.num_host_key_files)
1.404 markus 687: return (NULL);
688: return (sensitive_data.host_pubkeys[ind]);
689: }
690:
1.231 provos 691: int
1.488 markus 692: get_hostkey_index(struct sshkey *key, int compare, struct ssh *ssh)
1.231 provos 693: {
1.493 djm 694: u_int i;
1.250 deraadt 695:
1.231 provos 696: for (i = 0; i < options.num_host_key_files; i++) {
1.512 markus 697: if (sshkey_is_cert(key)) {
1.442 djm 698: if (key == sensitive_data.host_certificates[i] ||
699: (compare && sensitive_data.host_certificates[i] &&
700: sshkey_equal(key,
701: sensitive_data.host_certificates[i])))
1.373 djm 702: return (i);
703: } else {
1.442 djm 704: if (key == sensitive_data.host_keys[i] ||
705: (compare && sensitive_data.host_keys[i] &&
706: sshkey_equal(key, sensitive_data.host_keys[i])))
1.373 djm 707: return (i);
1.442 djm 708: if (key == sensitive_data.host_pubkeys[i] ||
709: (compare && sensitive_data.host_pubkeys[i] &&
710: sshkey_equal(key, sensitive_data.host_pubkeys[i])))
1.404 markus 711: return (i);
1.373 djm 712: }
1.231 provos 713: }
714: return (-1);
715: }
716:
1.439 djm 717: /* Inform the client of all hostkeys */
718: static void
719: notify_hostkeys(struct ssh *ssh)
720: {
721: struct sshbuf *buf;
722: struct sshkey *key;
1.493 djm 723: u_int i, nkeys;
724: int r;
1.439 djm 725: char *fp;
1.446 dtucker 726:
727: /* Some clients cannot cope with the hostkeys message, skip those. */
1.527 djm 728: if (ssh->compat & SSH_BUG_HOSTKEYS)
1.446 dtucker 729: return;
1.439 djm 730:
731: if ((buf = sshbuf_new()) == NULL)
1.564 djm 732: fatal_f("sshbuf_new");
1.439 djm 733: for (i = nkeys = 0; i < options.num_host_key_files; i++) {
734: key = get_hostkey_public_by_index(i, ssh);
735: if (key == NULL || key->type == KEY_UNSPEC ||
1.472 markus 736: sshkey_is_cert(key))
1.439 djm 737: continue;
738: fp = sshkey_fingerprint(key, options.fingerprint_hash,
739: SSH_FP_DEFAULT);
1.564 djm 740: debug3_f("key %d: %s %s", i, sshkey_ssh_name(key), fp);
1.439 djm 741: free(fp);
1.442 djm 742: if (nkeys == 0) {
1.525 djm 743: /*
744: * Start building the request when we find the
745: * first usable key.
746: */
747: if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
748: (r = sshpkt_put_cstring(ssh, "hostkeys-00@openssh.com")) != 0 ||
749: (r = sshpkt_put_u8(ssh, 0)) != 0) /* want reply */
750: sshpkt_fatal(ssh, r, "%s: start request", __func__);
1.442 djm 751: }
1.525 djm 752: /* Append the key to the request */
1.442 djm 753: sshbuf_reset(buf);
754: if ((r = sshkey_putb(key, buf)) != 0)
1.564 djm 755: fatal_fr(r, "couldn't put hostkey %d", i);
1.525 djm 756: if ((r = sshpkt_put_stringb(ssh, buf)) != 0)
757: sshpkt_fatal(ssh, r, "%s: append key", __func__);
1.439 djm 758: nkeys++;
759: }
1.564 djm 760: debug3_f("sent %u hostkeys", nkeys);
1.439 djm 761: if (nkeys == 0)
1.564 djm 762: fatal_f("no hostkeys");
1.525 djm 763: if ((r = sshpkt_send(ssh)) != 0)
764: sshpkt_fatal(ssh, r, "%s: send", __func__);
1.442 djm 765: sshbuf_free(buf);
1.439 djm 766: }
767:
1.124 markus 768: /*
769: * returns 1 if connection should be dropped, 0 otherwise.
770: * dropping starts at connection #max_startups_begin with a probability
771: * of (max_startups_rate/100). the probability increases linearly until
772: * all connections are dropped for startups > max_startups
773: */
1.200 itojun 774: static int
1.555 djm 775: should_drop_connection(int startups)
1.124 markus 776: {
1.303 mickey 777: int p, r;
1.124 markus 778:
779: if (startups < options.max_startups_begin)
780: return 0;
781: if (startups >= options.max_startups)
782: return 1;
783: if (options.max_startups_rate == 100)
784: return 1;
785:
786: p = 100 - options.max_startups_rate;
787: p *= startups - options.max_startups_begin;
1.303 mickey 788: p /= options.max_startups - options.max_startups_begin;
1.124 markus 789: p += options.max_startups_rate;
1.356 djm 790: r = arc4random_uniform(100);
1.124 markus 791:
1.564 djm 792: debug_f("p %d, r %d", p, r);
1.124 markus 793: return (r < p) ? 1 : 0;
794: }
795:
1.555 djm 796: /*
797: * Check whether connection should be accepted by MaxStartups.
798: * Returns 0 if the connection is accepted. If the connection is refused,
799: * returns 1 and attempts to send notification to client.
800: * Logs when the MaxStartups condition is entered or exited, and periodically
801: * while in that state.
802: */
803: static int
1.567 dtucker 804: drop_connection(int sock, int startups, int notify_pipe)
1.555 djm 805: {
806: char *laddr, *raddr;
807: const char msg[] = "Exceeded MaxStartups\r\n";
808: static time_t last_drop, first_drop;
809: static u_int ndropped;
810: LogLevel drop_level = SYSLOG_LEVEL_VERBOSE;
811: time_t now;
812:
813: now = monotime();
1.567 dtucker 814: if (!should_drop_connection(startups) &&
815: srclimit_check_allow(sock, notify_pipe) == 1) {
1.555 djm 816: if (last_drop != 0 &&
817: startups < options.max_startups_begin - 1) {
818: /* XXX maybe need better hysteresis here */
819: logit("exited MaxStartups throttling after %s, "
820: "%u connections dropped",
821: fmt_timeframe(now - first_drop), ndropped);
822: last_drop = 0;
823: }
824: return 0;
825: }
826:
827: #define SSHD_MAXSTARTUPS_LOG_INTERVAL (5 * 60)
828: if (last_drop == 0) {
829: error("beginning MaxStartups throttling");
830: drop_level = SYSLOG_LEVEL_INFO;
831: first_drop = now;
832: ndropped = 0;
833: } else if (last_drop + SSHD_MAXSTARTUPS_LOG_INTERVAL < now) {
834: /* Periodic logs */
835: error("in MaxStartups throttling for %s, "
836: "%u connections dropped",
837: fmt_timeframe(now - first_drop), ndropped + 1);
838: drop_level = SYSLOG_LEVEL_INFO;
839: }
840: last_drop = now;
841: ndropped++;
842:
843: laddr = get_local_ipaddr(sock);
844: raddr = get_peer_ipaddr(sock);
845: do_log2(drop_level, "drop connection #%d from [%s]:%d on [%s]:%d "
846: "past MaxStartups", startups, raddr, get_peer_port(sock),
847: laddr, get_local_port(sock));
848: free(laddr);
849: free(raddr);
850: /* best-effort notification to client */
851: (void)write(sock, msg, sizeof(msg) - 1);
852: return 1;
853: }
854:
1.215 markus 855: static void
856: usage(void)
857: {
1.565 dtucker 858: fprintf(stderr, "%s, %s\n", SSH_VERSION, SSH_OPENSSL_VERSION);
1.289 markus 859: fprintf(stderr,
1.597 djm 860: "usage: sshd [-46DdeGiqTtV] [-C connection_spec] [-c host_cert_file]\n"
1.399 dtucker 861: " [-E log_file] [-f config_file] [-g login_grace_time]\n"
1.473 naddy 862: " [-h host_key_file] [-o option] [-p port] [-u len]\n"
1.289 markus 863: );
1.215 markus 864: exit(1);
865: }
866:
1.294 djm 867: static void
1.467 djm 868: send_rexec_state(int fd, struct sshbuf *conf)
1.294 djm 869: {
1.546 djm 870: struct sshbuf *m = NULL, *inc = NULL;
871: struct include_item *item = NULL;
1.467 djm 872: int r;
1.294 djm 873:
1.564 djm 874: debug3_f("entering fd = %d config len %zu", fd,
1.467 djm 875: sshbuf_len(conf));
1.294 djm 876:
1.546 djm 877: if ((m = sshbuf_new()) == NULL || (inc = sshbuf_new()) == NULL)
1.564 djm 878: fatal_f("sshbuf_new failed");
1.546 djm 879:
880: /* pack includes into a string */
881: TAILQ_FOREACH(item, &includes, entry) {
882: if ((r = sshbuf_put_cstring(inc, item->selector)) != 0 ||
883: (r = sshbuf_put_cstring(inc, item->filename)) != 0 ||
1.547 djm 884: (r = sshbuf_put_stringb(inc, item->contents)) != 0)
1.564 djm 885: fatal_fr(r, "compose includes");
1.546 djm 886: }
887:
1.294 djm 888: /*
889: * Protocol from reexec master to child:
890: * string configuration
1.546 djm 891: * string included_files[] {
892: * string selector
893: * string filename
894: * string contents
895: * }
1.294 djm 896: */
1.546 djm 897: if ((r = sshbuf_put_stringb(m, conf)) != 0 ||
898: (r = sshbuf_put_stringb(m, inc)) != 0)
1.564 djm 899: fatal_fr(r, "compose config");
1.467 djm 900: if (ssh_msg_send(fd, 0, m) == -1)
1.564 djm 901: error_f("ssh_msg_send failed");
1.294 djm 902:
1.467 djm 903: sshbuf_free(m);
1.546 djm 904: sshbuf_free(inc);
1.294 djm 905:
1.564 djm 906: debug3_f("done");
1.294 djm 907: }
908:
909: static void
1.511 markus 910: recv_rexec_state(int fd, struct sshbuf *conf)
1.294 djm 911: {
1.546 djm 912: struct sshbuf *m, *inc;
1.511 markus 913: u_char *cp, ver;
914: size_t len;
915: int r;
1.546 djm 916: struct include_item *item;
1.294 djm 917:
1.564 djm 918: debug3_f("entering fd = %d", fd);
1.294 djm 919:
1.546 djm 920: if ((m = sshbuf_new()) == NULL || (inc = sshbuf_new()) == NULL)
1.564 djm 921: fatal_f("sshbuf_new failed");
1.511 markus 922: if (ssh_msg_recv(fd, m) == -1)
1.564 djm 923: fatal_f("ssh_msg_recv failed");
1.511 markus 924: if ((r = sshbuf_get_u8(m, &ver)) != 0)
1.564 djm 925: fatal_fr(r, "parse version");
1.511 markus 926: if (ver != 0)
1.564 djm 927: fatal_f("rexec version mismatch");
1.546 djm 928: if ((r = sshbuf_get_string(m, &cp, &len)) != 0 ||
929: (r = sshbuf_get_stringb(m, inc)) != 0)
1.564 djm 930: fatal_fr(r, "parse config");
1.546 djm 931:
1.511 markus 932: if (conf != NULL && (r = sshbuf_put(conf, cp, len)))
1.564 djm 933: fatal_fr(r, "sshbuf_put");
1.294 djm 934:
1.546 djm 935: while (sshbuf_len(inc) != 0) {
936: item = xcalloc(1, sizeof(*item));
937: if ((item->contents = sshbuf_new()) == NULL)
1.564 djm 938: fatal_f("sshbuf_new failed");
1.546 djm 939: if ((r = sshbuf_get_cstring(inc, &item->selector, NULL)) != 0 ||
940: (r = sshbuf_get_cstring(inc, &item->filename, NULL)) != 0 ||
941: (r = sshbuf_get_stringb(inc, item->contents)) != 0)
1.564 djm 942: fatal_fr(r, "parse includes");
1.546 djm 943: TAILQ_INSERT_TAIL(&includes, item, entry);
944: }
945:
1.402 djm 946: free(cp);
1.511 markus 947: sshbuf_free(m);
1.294 djm 948:
1.564 djm 949: debug3_f("done");
1.294 djm 950: }
951:
1.345 djm 952: /* Accept a connection from inetd */
953: static void
954: server_accept_inetd(int *sock_in, int *sock_out)
955: {
956: if (rexeced_flag) {
957: close(REEXEC_CONFIG_PASS_FD);
958: *sock_in = *sock_out = dup(STDIN_FILENO);
959: } else {
960: *sock_in = dup(STDIN_FILENO);
961: *sock_out = dup(STDOUT_FILENO);
962: }
963: /*
964: * We intentionally do not close the descriptors 0, 1, and 2
965: * as our code for setting the descriptors won't work if
966: * ttyfd happens to be one of those.
967: */
1.562 djm 968: if (stdfd_devnull(1, 1, !log_stderr) == -1)
1.564 djm 969: error_f("stdfd_devnull failed");
1.345 djm 970: debug("inetd sockets after dupping: %d, %d", *sock_in, *sock_out);
971: }
972:
973: /*
974: * Listen for TCP connections
975: */
976: static void
1.494 djm 977: listen_on_addrs(struct listenaddr *la)
1.345 djm 978: {
1.494 djm 979: int ret, listen_sock;
1.345 djm 980: struct addrinfo *ai;
981: char ntop[NI_MAXHOST], strport[NI_MAXSERV];
982:
1.494 djm 983: for (ai = la->addrs; ai; ai = ai->ai_next) {
1.345 djm 984: if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
985: continue;
986: if (num_listen_socks >= MAX_LISTEN_SOCKS)
987: fatal("Too many listen sockets. "
988: "Enlarge MAX_LISTEN_SOCKS");
989: if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen,
990: ntop, sizeof(ntop), strport, sizeof(strport),
991: NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
992: error("getnameinfo failed: %.100s",
1.352 dtucker 993: ssh_gai_strerror(ret));
1.345 djm 994: continue;
995: }
996: /* Create socket for listening. */
1.370 dtucker 997: listen_sock = socket(ai->ai_family, ai->ai_socktype,
998: ai->ai_protocol);
1.537 deraadt 999: if (listen_sock == -1) {
1.345 djm 1000: /* kernel may not support ipv6 */
1001: verbose("socket: %.100s", strerror(errno));
1002: continue;
1003: }
1004: if (set_nonblock(listen_sock) == -1) {
1.483 djm 1005: close(listen_sock);
1006: continue;
1007: }
1008: if (fcntl(listen_sock, F_SETFD, FD_CLOEXEC) == -1) {
1009: verbose("socket: CLOEXEC: %s", strerror(errno));
1.345 djm 1010: close(listen_sock);
1011: continue;
1012: }
1.494 djm 1013: /* Socket options */
1014: set_reuseaddr(listen_sock);
1015: if (la->rdomain != NULL &&
1016: set_rdomain(listen_sock, la->rdomain) == -1) {
1017: close(listen_sock);
1018: continue;
1019: }
1.345 djm 1020:
1021: debug("Bind to port %s on %s.", strport, ntop);
1022:
1023: /* Bind the socket to the desired port. */
1.537 deraadt 1024: if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) == -1) {
1.345 djm 1025: error("Bind to port %s on %s failed: %.200s.",
1026: strport, ntop, strerror(errno));
1027: close(listen_sock);
1028: continue;
1029: }
1030: listen_socks[num_listen_socks] = listen_sock;
1031: num_listen_socks++;
1032:
1033: /* Start listening on the port. */
1.537 deraadt 1034: if (listen(listen_sock, SSH_LISTEN_BACKLOG) == -1)
1.345 djm 1035: fatal("listen on [%s]:%s: %.100s",
1036: ntop, strport, strerror(errno));
1.494 djm 1037: logit("Server listening on %s port %s%s%s.",
1038: ntop, strport,
1039: la->rdomain == NULL ? "" : " rdomain ",
1040: la->rdomain == NULL ? "" : la->rdomain);
1.345 djm 1041: }
1.494 djm 1042: }
1043:
1044: static void
1045: server_listen(void)
1046: {
1047: u_int i;
1048:
1.567 dtucker 1049: /* Initialise per-source limit tracking. */
1050: srclimit_init(options.max_startups, options.per_source_max_startups,
1051: options.per_source_masklen_ipv4, options.per_source_masklen_ipv6);
1052:
1.494 djm 1053: for (i = 0; i < options.num_listen_addrs; i++) {
1054: listen_on_addrs(&options.listen_addrs[i]);
1055: freeaddrinfo(options.listen_addrs[i].addrs);
1056: free(options.listen_addrs[i].rdomain);
1057: memset(&options.listen_addrs[i], 0,
1058: sizeof(options.listen_addrs[i]));
1059: }
1060: free(options.listen_addrs);
1061: options.listen_addrs = NULL;
1062: options.num_listen_addrs = 0;
1.345 djm 1063:
1064: if (!num_listen_socks)
1065: fatal("Cannot bind any address.");
1066: }
1067:
1068: /*
1069: * The main TCP accept loop. Note that, for the non-debug case, returns
1070: * from this function are in a forked subprocess.
1071: */
1072: static void
1073: server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
1074: {
1.579 deraadt 1075: struct pollfd *pfd = NULL;
1.584 djm 1076: int i, j, ret, npfd;
1.543 djm 1077: int ostartups = -1, startups = 0, listening = 0, lameduck = 0;
1.584 djm 1078: int startup_p[2] = { -1 , -1 }, *startup_pollfd;
1.533 djm 1079: char c = 0;
1.345 djm 1080: struct sockaddr_storage from;
1081: socklen_t fromlen;
1082: pid_t pid;
1.574 dtucker 1083: sigset_t nsigset, osigset;
1.345 djm 1084:
1085: /* setup fd set for accept */
1.550 djm 1086: /* pipes connected to unauthenticated child sshd processes */
1.345 djm 1087: startup_pipes = xcalloc(options.max_startups, sizeof(int));
1.533 djm 1088: startup_flags = xcalloc(options.max_startups, sizeof(int));
1.584 djm 1089: startup_pollfd = xcalloc(options.max_startups, sizeof(int));
1.345 djm 1090: for (i = 0; i < options.max_startups; i++)
1091: startup_pipes[i] = -1;
1092:
1093: /*
1.574 dtucker 1094: * Prepare signal mask that we use to block signals that might set
1095: * received_sigterm or received_sighup, so that we are guaranteed
1.579 deraadt 1096: * to immediately wake up the ppoll if a signal is received after
1.574 dtucker 1097: * the flag is checked.
1098: */
1099: sigemptyset(&nsigset);
1100: sigaddset(&nsigset, SIGHUP);
1101: sigaddset(&nsigset, SIGCHLD);
1102: sigaddset(&nsigset, SIGTERM);
1103: sigaddset(&nsigset, SIGQUIT);
1104:
1.584 djm 1105: /* sized for worst-case */
1.579 deraadt 1106: pfd = xcalloc(num_listen_socks + options.max_startups,
1107: sizeof(struct pollfd));
1108:
1.574 dtucker 1109: /*
1.345 djm 1110: * Stay listening for connections until the system crashes or
1111: * the daemon is killed with a signal.
1112: */
1113: for (;;) {
1.574 dtucker 1114: sigprocmask(SIG_BLOCK, &nsigset, &osigset);
1115: if (received_sigterm) {
1116: logit("Received signal %d; terminating.",
1117: (int) received_sigterm);
1118: close_listen_socks();
1119: if (options.pid_file != NULL)
1120: unlink(options.pid_file);
1121: exit(received_sigterm == SIGTERM ? 0 : 255);
1122: }
1.543 djm 1123: if (ostartups != startups) {
1.545 djm 1124: setproctitle("%s [listener] %d of %d-%d startups",
1125: listener_proctitle, startups,
1126: options.max_startups_begin, options.max_startups);
1.543 djm 1127: ostartups = startups;
1128: }
1.533 djm 1129: if (received_sighup) {
1130: if (!lameduck) {
1131: debug("Received SIGHUP; waiting for children");
1132: close_listen_socks();
1133: lameduck = 1;
1134: }
1.574 dtucker 1135: if (listening <= 0) {
1136: sigprocmask(SIG_SETMASK, &osigset, NULL);
1.533 djm 1137: sighup_restart();
1.574 dtucker 1138: }
1.533 djm 1139: }
1.345 djm 1140:
1.579 deraadt 1141: for (i = 0; i < num_listen_socks; i++) {
1142: pfd[i].fd = listen_socks[i];
1143: pfd[i].events = POLLIN;
1144: }
1.584 djm 1145: npfd = num_listen_socks;
1.579 deraadt 1146: for (i = 0; i < options.max_startups; i++) {
1.584 djm 1147: startup_pollfd[i] = -1;
1148: if (startup_pipes[i] != -1) {
1149: pfd[npfd].fd = startup_pipes[i];
1150: pfd[npfd].events = POLLIN;
1151: startup_pollfd[i] = npfd++;
1152: }
1.579 deraadt 1153: }
1.345 djm 1154:
1.574 dtucker 1155: /* Wait until a connection arrives or a child exits. */
1.584 djm 1156: ret = ppoll(pfd, npfd, NULL, &osigset);
1157: if (ret == -1 && errno != EINTR) {
1.579 deraadt 1158: error("ppoll: %.100s", strerror(errno));
1.584 djm 1159: if (errno == EINVAL)
1160: cleanup_exit(1); /* can't recover */
1161: }
1.574 dtucker 1162: sigprocmask(SIG_SETMASK, &osigset, NULL);
1.576 dtucker 1163: if (ret == -1)
1.345 djm 1164: continue;
1165:
1.533 djm 1166: for (i = 0; i < options.max_startups; i++) {
1167: if (startup_pipes[i] == -1 ||
1.584 djm 1168: startup_pollfd[i] == -1 ||
1169: !(pfd[startup_pollfd[i]].revents & (POLLIN|POLLHUP)))
1.533 djm 1170: continue;
1171: switch (read(startup_pipes[i], &c, sizeof(c))) {
1172: case -1:
1173: if (errno == EINTR || errno == EAGAIN)
1174: continue;
1175: if (errno != EPIPE) {
1.564 djm 1176: error_f("startup pipe %d (fd=%d): "
1177: "read %s", i, startup_pipes[i],
1178: strerror(errno));
1.533 djm 1179: }
1180: /* FALLTHROUGH */
1181: case 0:
1182: /* child exited or completed auth */
1.345 djm 1183: close(startup_pipes[i]);
1.567 dtucker 1184: srclimit_done(startup_pipes[i]);
1.345 djm 1185: startup_pipes[i] = -1;
1186: startups--;
1.533 djm 1187: if (startup_flags[i])
1188: listening--;
1189: break;
1190: case 1:
1191: /* child has finished preliminaries */
1192: if (startup_flags[i]) {
1193: listening--;
1194: startup_flags[i] = 0;
1195: }
1196: break;
1.345 djm 1197: }
1.533 djm 1198: }
1.345 djm 1199: for (i = 0; i < num_listen_socks; i++) {
1.579 deraadt 1200: if (!(pfd[i].revents & POLLIN))
1.345 djm 1201: continue;
1202: fromlen = sizeof(from);
1203: *newsock = accept(listen_socks[i],
1204: (struct sockaddr *)&from, &fromlen);
1.537 deraadt 1205: if (*newsock == -1) {
1.398 markus 1206: if (errno != EINTR && errno != EWOULDBLOCK &&
1207: errno != ECONNABORTED)
1.389 djm 1208: error("accept: %.100s",
1209: strerror(errno));
1210: if (errno == EMFILE || errno == ENFILE)
1211: usleep(100 * 1000);
1.345 djm 1212: continue;
1213: }
1.586 dtucker 1214: if (unset_nonblock(*newsock) == -1) {
1215: close(*newsock);
1216: continue;
1217: }
1218: if (pipe(startup_p) == -1) {
1219: error_f("pipe(startup_p): %s", strerror(errno));
1.582 djm 1220: close(*newsock);
1.567 dtucker 1221: continue;
1.582 djm 1222: }
1.567 dtucker 1223: if (drop_connection(*newsock, startups, startup_p[0])) {
1.345 djm 1224: close(*newsock);
1.567 dtucker 1225: close(startup_p[0]);
1226: close(startup_p[1]);
1.345 djm 1227: continue;
1228: }
1229:
1230: if (rexec_flag && socketpair(AF_UNIX,
1231: SOCK_STREAM, 0, config_s) == -1) {
1232: error("reexec socketpair: %s",
1233: strerror(errno));
1234: close(*newsock);
1235: close(startup_p[0]);
1236: close(startup_p[1]);
1237: continue;
1238: }
1239:
1240: for (j = 0; j < options.max_startups; j++)
1241: if (startup_pipes[j] == -1) {
1242: startup_pipes[j] = startup_p[0];
1243: startups++;
1.533 djm 1244: startup_flags[j] = 1;
1.345 djm 1245: break;
1246: }
1247:
1248: /*
1249: * Got connection. Fork a child to handle it, unless
1250: * we are in debugging mode.
1251: */
1252: if (debug_flag) {
1253: /*
1254: * In debugging mode. Close the listening
1255: * socket, and start processing the
1256: * connection without forking.
1257: */
1258: debug("Server will not fork when running in debugging mode.");
1259: close_listen_socks();
1260: *sock_in = *newsock;
1261: *sock_out = *newsock;
1262: close(startup_p[0]);
1263: close(startup_p[1]);
1264: startup_pipe = -1;
1265: pid = getpid();
1266: if (rexec_flag) {
1.511 markus 1267: send_rexec_state(config_s[0], cfg);
1.345 djm 1268: close(config_s[0]);
1269: }
1.579 deraadt 1270: free(pfd);
1.533 djm 1271: return;
1.345 djm 1272: }
1273:
1274: /*
1275: * Normal production daemon. Fork, and have
1276: * the child process the connection. The
1277: * parent continues listening.
1278: */
1.533 djm 1279: listening++;
1.345 djm 1280: if ((pid = fork()) == 0) {
1281: /*
1282: * Child. Close the listening and
1283: * max_startup sockets. Start using
1284: * the accepted socket. Reinitialize
1285: * logging (since our pid has changed).
1.533 djm 1286: * We return from this function to handle
1.345 djm 1287: * the connection.
1288: */
1289: startup_pipe = startup_p[1];
1290: close_startup_pipes();
1291: close_listen_socks();
1292: *sock_in = *newsock;
1293: *sock_out = *newsock;
1294: log_init(__progname,
1295: options.log_level,
1296: options.log_facility,
1297: log_stderr);
1298: if (rexec_flag)
1299: close(config_s[0]);
1.533 djm 1300: else {
1301: /*
1302: * Signal parent that the preliminaries
1303: * for this child are complete. For the
1304: * re-exec case, this happens after the
1305: * child has received the rexec state
1306: * from the server.
1307: */
1308: (void)atomicio(vwrite, startup_pipe,
1309: "\0", 1);
1310: }
1.579 deraadt 1311: free(pfd);
1.533 djm 1312: return;
1.345 djm 1313: }
1314:
1315: /* Parent. Stay in the loop. */
1.537 deraadt 1316: if (pid == -1)
1.345 djm 1317: error("fork: %.100s", strerror(errno));
1318: else
1319: debug("Forked child %ld.", (long)pid);
1320:
1321: close(startup_p[1]);
1322:
1323: if (rexec_flag) {
1.554 markus 1324: close(config_s[1]);
1.511 markus 1325: send_rexec_state(config_s[0], cfg);
1.345 djm 1326: close(config_s[0]);
1327: }
1328: close(*newsock);
1329: }
1330: }
1331: }
1332:
1.466 djm 1333: /*
1334: * If IP options are supported, make sure there are none (log and
1335: * return an error if any are found). Basically we are worried about
1336: * source routing; it can be used to pretend you are somebody
1337: * (ip-address) you are not. That itself may be "almost acceptable"
1.507 djm 1338: * under certain circumstances, but rhosts authentication is useless
1.466 djm 1339: * if source routing is accepted. Notice also that if we just dropped
1340: * source routing here, the other side could use IP spoofing to do
1341: * rest of the interaction and could still bypass security. So we
1342: * exit here if we detect any IP options.
1343: */
1344: static void
1345: check_ip_options(struct ssh *ssh)
1346: {
1347: int sock_in = ssh_packet_get_connection_in(ssh);
1348: struct sockaddr_storage from;
1349: u_char opts[200];
1.475 djm 1350: socklen_t i, option_size = sizeof(opts), fromlen = sizeof(from);
1.466 djm 1351: char text[sizeof(opts) * 3 + 1];
1352:
1353: memset(&from, 0, sizeof(from));
1354: if (getpeername(sock_in, (struct sockaddr *)&from,
1.537 deraadt 1355: &fromlen) == -1)
1.466 djm 1356: return;
1357: if (from.ss_family != AF_INET)
1358: return;
1359: /* XXX IPv6 options? */
1360:
1361: if (getsockopt(sock_in, IPPROTO_IP, IP_OPTIONS, opts,
1362: &option_size) >= 0 && option_size != 0) {
1363: text[0] = '\0';
1364: for (i = 0; i < option_size; i++)
1365: snprintf(text + i*3, sizeof(text) - i*3,
1366: " %2.2x", opts[i]);
1367: fatal("Connection from %.100s port %d with IP opts: %.800s",
1368: ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), text);
1369: }
1370: return;
1371: }
1.345 djm 1372:
1.495 djm 1373: /* Set the routing domain for this process */
1374: static void
1375: set_process_rdomain(struct ssh *ssh, const char *name)
1376: {
1377: int rtable, ortable = getrtable();
1378: const char *errstr;
1379:
1380: if (name == NULL)
1381: return; /* default */
1382:
1383: if (strcmp(name, "%D") == 0) {
1384: /* "expands" to routing domain of connection */
1385: if ((name = ssh_packet_rdomain_in(ssh)) == NULL)
1386: return;
1387: }
1388:
1389: rtable = (int)strtonum(name, 0, 255, &errstr);
1390: if (errstr != NULL) /* Shouldn't happen */
1391: fatal("Invalid routing domain \"%s\": %s", name, errstr);
1392: if (rtable != ortable && setrtable(rtable) != 0)
1393: fatal("Unable to set routing domain %d: %s",
1394: rtable, strerror(errno));
1.564 djm 1395: debug_f("set routing domain %d (was %d)", rtable, ortable);
1.495 djm 1396: }
1397:
1.508 dtucker 1398: static void
1399: accumulate_host_timing_secret(struct sshbuf *server_cfg,
1.536 djm 1400: struct sshkey *key)
1.508 dtucker 1401: {
1402: static struct ssh_digest_ctx *ctx;
1403: u_char *hash;
1404: size_t len;
1405: struct sshbuf *buf;
1406: int r;
1407:
1408: if (ctx == NULL && (ctx = ssh_digest_start(SSH_DIGEST_SHA512)) == NULL)
1.564 djm 1409: fatal_f("ssh_digest_start");
1.508 dtucker 1410: if (key == NULL) { /* finalize */
1411: /* add server config in case we are using agent for host keys */
1412: if (ssh_digest_update(ctx, sshbuf_ptr(server_cfg),
1413: sshbuf_len(server_cfg)) != 0)
1.564 djm 1414: fatal_f("ssh_digest_update");
1.508 dtucker 1415: len = ssh_digest_bytes(SSH_DIGEST_SHA512);
1416: hash = xmalloc(len);
1417: if (ssh_digest_final(ctx, hash, len) != 0)
1.564 djm 1418: fatal_f("ssh_digest_final");
1.508 dtucker 1419: options.timing_secret = PEEK_U64(hash);
1420: freezero(hash, len);
1421: ssh_digest_free(ctx);
1422: ctx = NULL;
1423: return;
1424: }
1425: if ((buf = sshbuf_new()) == NULL)
1.564 djm 1426: fatal_f("could not allocate buffer");
1.508 dtucker 1427: if ((r = sshkey_private_serialize(key, buf)) != 0)
1.592 djm 1428: fatal_fr(r, "encode %s key", sshkey_ssh_name(key));
1.508 dtucker 1429: if (ssh_digest_update(ctx, sshbuf_ptr(buf), sshbuf_len(buf)) != 0)
1.564 djm 1430: fatal_f("ssh_digest_update");
1.508 dtucker 1431: sshbuf_reset(buf);
1432: sshbuf_free(buf);
1433: }
1434:
1.545 djm 1435: static char *
1436: prepare_proctitle(int ac, char **av)
1437: {
1438: char *ret = NULL;
1439: int i;
1440:
1441: for (i = 0; i < ac; i++)
1442: xextendf(&ret, " ", "%s", av[i]);
1443: return ret;
1444: }
1445:
1.597 djm 1446: static void
1447: print_config(struct ssh *ssh, struct connection_info *connection_info)
1448: {
1449: /*
1450: * If no connection info was provided by -C then use
1451: * use a blank one that will cause no predicate to match.
1452: */
1453: if (connection_info == NULL)
1454: connection_info = get_connection_info(ssh, 0, 0);
1455: connection_info->test = 1;
1456: parse_server_match_config(&options, &includes, connection_info);
1457: dump_config(&options);
1458: exit(0);
1459: }
1460:
1.65 deraadt 1461: /*
1462: * Main program for the daemon.
1463: */
1.2 provos 1464: int
1465: main(int ac, char **av)
1.1 deraadt 1466: {
1.466 djm 1467: struct ssh *ssh = NULL;
1.64 markus 1468: extern char *optarg;
1469: extern int optind;
1.597 djm 1470: int r, opt, on = 1, do_dump_cfg = 0, already_daemon, remote_port;
1.297 avsm 1471: int sock_in = -1, sock_out = -1, newsock = -1;
1.496 djm 1472: const char *remote_ip, *rdomain;
1.447 dtucker 1473: char *fp, *line, *laddr, *logfile = NULL;
1.345 djm 1474: int config_s[2] = { -1 , -1 };
1.493 djm 1475: u_int i, j;
1.364 markus 1476: u_int64_t ibytes, obytes;
1.362 dtucker 1477: mode_t new_umask;
1.488 markus 1478: struct sshkey *key;
1479: struct sshkey *pubkey;
1.404 markus 1480: int keytype;
1.230 provos 1481: Authctxt *authctxt;
1.498 dtucker 1482: struct connection_info *connection_info = NULL;
1.594 djm 1483: sigset_t sigmask;
1484:
1485: sigemptyset(&sigmask);
1486: sigprocmask(SIG_SETMASK, &sigmask, NULL);
1.64 markus 1487:
1.138 markus 1488: /* Save argv. */
1.64 markus 1489: saved_argv = av;
1.294 djm 1490: rexec_argc = ac;
1.313 djm 1491:
1492: /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1493: sanitise_stdfd();
1.64 markus 1494:
1495: /* Initialize configuration options to their default values. */
1496: initialize_server_options(&options);
1497:
1498: /* Parse command-line arguments. */
1.450 djm 1499: while ((opt = getopt(ac, av,
1.597 djm 1500: "C:E:b:c:f:g:h:k:o:p:u:46DGQRTdeiqrtV")) != -1) {
1.64 markus 1501: switch (opt) {
1.75 markus 1502: case '4':
1.305 djm 1503: options.address_family = AF_INET;
1.75 markus 1504: break;
1505: case '6':
1.305 djm 1506: options.address_family = AF_INET6;
1.75 markus 1507: break;
1.64 markus 1508: case 'f':
1509: config_file_name = optarg;
1510: break;
1.373 djm 1511: case 'c':
1.493 djm 1512: servconf_add_hostcert("[command-line]", 0,
1513: &options, optarg);
1.373 djm 1514: break;
1.64 markus 1515: case 'd':
1.273 markus 1516: if (debug_flag == 0) {
1.127 markus 1517: debug_flag = 1;
1518: options.log_level = SYSLOG_LEVEL_DEBUG1;
1.273 markus 1519: } else if (options.log_level < SYSLOG_LEVEL_DEBUG3)
1.127 markus 1520: options.log_level++;
1.64 markus 1521: break;
1.135 markus 1522: case 'D':
1523: no_daemon_flag = 1;
1.192 lebel 1524: break;
1.597 djm 1525: case 'G':
1526: do_dump_cfg = 1;
1527: break;
1.399 dtucker 1528: case 'E':
1.459 dtucker 1529: logfile = optarg;
1.399 dtucker 1530: /* FALLTHROUGH */
1.192 lebel 1531: case 'e':
1532: log_stderr = 1;
1.135 markus 1533: break;
1.64 markus 1534: case 'i':
1535: inetd_flag = 1;
1536: break;
1.294 djm 1537: case 'r':
1538: rexec_flag = 0;
1539: break;
1540: case 'R':
1541: rexeced_flag = 1;
1542: inetd_flag = 1;
1543: break;
1.64 markus 1544: case 'Q':
1.158 markus 1545: /* ignored */
1.64 markus 1546: break;
1547: case 'q':
1548: options.log_level = SYSLOG_LEVEL_QUIET;
1549: break;
1550: case 'b':
1.473 naddy 1551: /* protocol 1, ignored */
1.64 markus 1552: break;
1553: case 'p':
1.75 markus 1554: options.ports_from_cmdline = 1;
1.127 markus 1555: if (options.num_ports >= MAX_PORTS) {
1556: fprintf(stderr, "too many ports.\n");
1557: exit(1);
1558: }
1.193 stevesk 1559: options.ports[options.num_ports++] = a2port(optarg);
1.366 djm 1560: if (options.ports[options.num_ports-1] <= 0) {
1.193 stevesk 1561: fprintf(stderr, "Bad port number.\n");
1562: exit(1);
1563: }
1.64 markus 1564: break;
1565: case 'g':
1.197 stevesk 1566: if ((options.login_grace_time = convtime(optarg)) == -1) {
1567: fprintf(stderr, "Invalid login grace time.\n");
1568: exit(1);
1569: }
1.64 markus 1570: break;
1571: case 'k':
1.473 naddy 1572: /* protocol 1, ignored */
1.64 markus 1573: break;
1574: case 'h':
1.493 djm 1575: servconf_add_hostkey("[command-line]", 0,
1.519 djm 1576: &options, optarg, 1);
1.64 markus 1577: break;
1.203 stevesk 1578: case 't':
1579: test_flag = 1;
1580: break;
1.358 dtucker 1581: case 'T':
1582: test_flag = 2;
1583: break;
1584: case 'C':
1.523 djm 1585: connection_info = get_connection_info(ssh, 0, 0);
1.391 dtucker 1586: if (parse_server_match_testspec(connection_info,
1587: optarg) == -1)
1588: exit(1);
1.358 dtucker 1589: break;
1.125 markus 1590: case 'u':
1.438 deraadt 1591: utmp_len = (u_int)strtonum(optarg, 0, HOST_NAME_MAX+1+1, NULL);
1592: if (utmp_len > HOST_NAME_MAX+1) {
1.257 stevesk 1593: fprintf(stderr, "Invalid utmp length.\n");
1594: exit(1);
1595: }
1.125 markus 1596: break;
1.215 markus 1597: case 'o':
1.283 markus 1598: line = xstrdup(optarg);
1599: if (process_server_config_line(&options, line,
1.546 djm 1600: "command-line", 0, NULL, NULL, &includes) != 0)
1.217 deraadt 1601: exit(1);
1.402 djm 1602: free(line);
1.215 markus 1603: break;
1.596 millert 1604: case 'V':
1605: fprintf(stderr, "%s, %s\n",
1606: SSH_VERSION, SSH_OPENSSL_VERSION);
1607: exit(0);
1.64 markus 1608: default:
1.215 markus 1609: usage();
1610: break;
1.64 markus 1611: }
1612: }
1.294 djm 1613: if (rexeced_flag || inetd_flag)
1614: rexec_flag = 0;
1.597 djm 1615: if (!test_flag && !do_dump_cfg && rexec_flag && !path_absolute(av[0]))
1.294 djm 1616: fatal("sshd re-exec requires execution with an absolute path");
1617: if (rexeced_flag)
1.296 djm 1618: closefrom(REEXEC_MIN_FREE_FD);
1619: else
1620: closefrom(REEXEC_DEVCRYPTO_RESERVED_FD);
1.294 djm 1621:
1.426 markus 1622: #ifdef WITH_OPENSSL
1.379 djm 1623: OpenSSL_add_all_algorithms();
1.426 markus 1624: #endif
1.64 markus 1625:
1.399 dtucker 1626: /* If requested, redirect the logs to the specified logfile. */
1.459 dtucker 1627: if (logfile != NULL)
1.399 dtucker 1628: log_redirect_stderr_to(logfile);
1.75 markus 1629: /*
1630: * Force logging to stderr until we have loaded the private host
1631: * key (unless started from inetd)
1632: */
1.138 markus 1633: log_init(__progname,
1.224 markus 1634: options.log_level == SYSLOG_LEVEL_NOT_SET ?
1635: SYSLOG_LEVEL_INFO : options.log_level,
1636: options.log_facility == SYSLOG_FACILITY_NOT_SET ?
1637: SYSLOG_FACILITY_AUTH : options.log_facility,
1.548 djm 1638: log_stderr || !inetd_flag || debug_flag);
1.75 markus 1639:
1.294 djm 1640: sensitive_data.have_ssh2_key = 0;
1641:
1.358 dtucker 1642: /*
1.498 dtucker 1643: * If we're not doing an extended test do not silently ignore connection
1644: * test params.
1.358 dtucker 1645: */
1.498 dtucker 1646: if (test_flag < 2 && connection_info != NULL)
1.358 dtucker 1647: fatal("Config test connection parameter (-C) provided without "
1.572 djm 1648: "test mode (-T)");
1.358 dtucker 1649:
1.294 djm 1650: /* Fetch our configuration */
1.511 markus 1651: if ((cfg = sshbuf_new()) == NULL)
1.564 djm 1652: fatal_f("sshbuf_new failed");
1.533 djm 1653: if (rexeced_flag) {
1.560 markus 1654: setproctitle("%s", "[rexeced]");
1.511 markus 1655: recv_rexec_state(REEXEC_CONFIG_PASS_FD, cfg);
1.533 djm 1656: if (!debug_flag) {
1657: startup_pipe = dup(REEXEC_STARTUP_PIPE_FD);
1658: close(REEXEC_STARTUP_PIPE_FD);
1659: /*
1660: * Signal parent that this child is at a point where
1661: * they can go away if they have a SIGHUP pending.
1662: */
1663: (void)atomicio(vwrite, startup_pipe, "\0", 1);
1664: }
1.549 djm 1665: } else if (strcasecmp(config_file_name, "none") != 0)
1.511 markus 1666: load_server_config(config_file_name, cfg);
1.294 djm 1667:
1.337 dtucker 1668: parse_server_config(&options, rexeced_flag ? "rexec" : config_file_name,
1.585 djm 1669: cfg, &includes, NULL, rexeced_flag);
1.571 dtucker 1670:
1.578 dtucker 1671: #ifdef WITH_OPENSSL
1.571 dtucker 1672: if (options.moduli_file != NULL)
1673: dh_set_moduli_file(options.moduli_file);
1.578 dtucker 1674: #endif
1.64 markus 1675:
1676: /* Fill in default values for those options not explicitly set. */
1677: fill_default_server_options(&options);
1.395 djm 1678:
1679: /* Check that options are sensible */
1680: if (options.authorized_keys_command_user == NULL &&
1681: (options.authorized_keys_command != NULL &&
1682: strcasecmp(options.authorized_keys_command, "none") != 0))
1683: fatal("AuthorizedKeysCommand set without "
1684: "AuthorizedKeysCommandUser");
1.449 djm 1685: if (options.authorized_principals_command_user == NULL &&
1686: (options.authorized_principals_command != NULL &&
1687: strcasecmp(options.authorized_principals_command, "none") != 0))
1688: fatal("AuthorizedPrincipalsCommand set without "
1689: "AuthorizedPrincipalsCommandUser");
1.396 djm 1690:
1691: /*
1692: * Check whether there is any path through configured auth methods.
1693: * Unfortunately it is not possible to verify this generally before
1694: * daemonisation in the presence of Match block, but this catches
1695: * and warns for trivial misconfigurations that could break login.
1696: */
1697: if (options.num_auth_methods != 0) {
1.493 djm 1698: for (i = 0; i < options.num_auth_methods; i++) {
1699: if (auth2_methods_valid(options.auth_methods[i],
1.396 djm 1700: 1) == 0)
1701: break;
1702: }
1.493 djm 1703: if (i >= options.num_auth_methods)
1.396 djm 1704: fatal("AuthenticationMethods cannot be satisfied by "
1705: "enabled authentication methods");
1706: }
1.305 djm 1707:
1.64 markus 1708: /* Check that there are no remaining arguments. */
1709: if (optind < ac) {
1710: fprintf(stderr, "Extra argument %s.\n", av[optind]);
1711: exit(1);
1712: }
1713:
1.565 dtucker 1714: debug("sshd version %s, %s", SSH_VERSION, SSH_OPENSSL_VERSION);
1.64 markus 1715:
1.597 djm 1716: if (do_dump_cfg)
1717: print_config(ssh, connection_info);
1718:
1.404 markus 1719: /* load host keys */
1.329 djm 1720: sensitive_data.host_keys = xcalloc(options.num_host_key_files,
1.488 markus 1721: sizeof(struct sshkey *));
1.404 markus 1722: sensitive_data.host_pubkeys = xcalloc(options.num_host_key_files,
1.488 markus 1723: sizeof(struct sshkey *));
1.404 markus 1724:
1725: if (options.host_key_agent) {
1726: if (strcmp(options.host_key_agent, SSH_AUTHSOCKET_ENV_NAME))
1727: setenv(SSH_AUTHSOCKET_ENV_NAME,
1728: options.host_key_agent, 1);
1.433 djm 1729: if ((r = ssh_get_authentication_socket(NULL)) == 0)
1730: have_agent = 1;
1731: else
1.564 djm 1732: error_r(r, "Could not connect to agent \"%s\"",
1733: options.host_key_agent);
1.404 markus 1734: }
1.134 markus 1735:
1.217 deraadt 1736: for (i = 0; i < options.num_host_key_files; i++) {
1.519 djm 1737: int ll = options.host_key_file_userprovided[i] ?
1738: SYSLOG_LEVEL_ERROR : SYSLOG_LEVEL_DEBUG1;
1739:
1.430 djm 1740: if (options.host_key_files[i] == NULL)
1741: continue;
1.512 markus 1742: if ((r = sshkey_load_private(options.host_key_files[i], "",
1743: &key, NULL)) != 0 && r != SSH_ERR_SYSTEM_ERROR)
1.564 djm 1744: do_log2_r(r, ll, "Unable to load host key \"%s\"",
1745: options.host_key_files[i]);
1.542 djm 1746: if (sshkey_is_sk(key) &&
1747: key->sk_flags & SSH_SK_USER_PRESENCE_REQD) {
1748: debug("host key %s requires user presence, ignoring",
1749: options.host_key_files[i]);
1750: key->sk_flags &= ~SSH_SK_USER_PRESENCE_REQD;
1751: }
1752: if (r == 0 && key != NULL &&
1753: (r = sshkey_shield_private(key)) != 0) {
1.564 djm 1754: do_log2_r(r, ll, "Unable to shield host key \"%s\"",
1755: options.host_key_files[i]);
1.536 djm 1756: sshkey_free(key);
1757: key = NULL;
1758: }
1.512 markus 1759: if ((r = sshkey_load_public(options.host_key_files[i],
1760: &pubkey, NULL)) != 0 && r != SSH_ERR_SYSTEM_ERROR)
1.564 djm 1761: do_log2_r(r, ll, "Unable to load host key \"%s\"",
1762: options.host_key_files[i]);
1.557 djm 1763: if (pubkey != NULL && key != NULL) {
1764: if (!sshkey_equal(pubkey, key)) {
1765: error("Public key for %s does not match "
1766: "private key", options.host_key_files[i]);
1767: sshkey_free(pubkey);
1768: pubkey = NULL;
1769: }
1770: }
1771: if (pubkey == NULL && key != NULL) {
1.515 djm 1772: if ((r = sshkey_from_private(key, &pubkey)) != 0)
1.564 djm 1773: fatal_r(r, "Could not demote key: \"%s\"",
1774: options.host_key_files[i]);
1.591 djm 1775: }
1776: if (pubkey != NULL && (r = sshkey_check_rsa_length(pubkey,
1777: options.required_rsa_size)) != 0) {
1778: error_fr(r, "Host key %s", options.host_key_files[i]);
1779: sshkey_free(pubkey);
1780: sshkey_free(key);
1781: continue;
1.557 djm 1782: }
1.179 markus 1783: sensitive_data.host_keys[i] = key;
1.404 markus 1784: sensitive_data.host_pubkeys[i] = pubkey;
1785:
1.472 markus 1786: if (key == NULL && pubkey != NULL && have_agent) {
1.443 djm 1787: debug("will rely on agent for hostkey %s",
1788: options.host_key_files[i]);
1.404 markus 1789: keytype = pubkey->type;
1790: } else if (key != NULL) {
1791: keytype = key->type;
1.511 markus 1792: accumulate_host_timing_secret(cfg, key);
1.404 markus 1793: } else {
1.519 djm 1794: do_log2(ll, "Unable to load host key: %s",
1.195 markus 1795: options.host_key_files[i]);
1.179 markus 1796: sensitive_data.host_keys[i] = NULL;
1.404 markus 1797: sensitive_data.host_pubkeys[i] = NULL;
1.134 markus 1798: continue;
1799: }
1.404 markus 1800:
1801: switch (keytype) {
1.134 markus 1802: case KEY_RSA:
1803: case KEY_DSA:
1.378 djm 1804: case KEY_ECDSA:
1.412 markus 1805: case KEY_ED25519:
1.542 djm 1806: case KEY_ECDSA_SK:
1807: case KEY_ED25519_SK:
1.505 markus 1808: case KEY_XMSS:
1.441 djm 1809: if (have_agent || key != NULL)
1810: sensitive_data.have_ssh2_key = 1;
1.134 markus 1811: break;
1812: }
1.441 djm 1813: if ((fp = sshkey_fingerprint(pubkey, options.fingerprint_hash,
1814: SSH_FP_DEFAULT)) == NULL)
1815: fatal("sshkey_fingerprint failed");
1816: debug("%s host key #%d: %s %s",
1.472 markus 1817: key ? "private" : "agent", i, sshkey_ssh_name(pubkey), fp);
1.441 djm 1818: free(fp);
1.134 markus 1819: }
1.511 markus 1820: accumulate_host_timing_secret(cfg, NULL);
1.472 markus 1821: if (!sensitive_data.have_ssh2_key) {
1.264 itojun 1822: logit("sshd: no hostkeys available -- exiting.");
1.64 markus 1823: exit(1);
1824: }
1825:
1.373 djm 1826: /*
1827: * Load certificates. They are stored in an array at identical
1828: * indices to the public keys that they relate to.
1829: */
1830: sensitive_data.host_certificates = xcalloc(options.num_host_key_files,
1.488 markus 1831: sizeof(struct sshkey *));
1.373 djm 1832: for (i = 0; i < options.num_host_key_files; i++)
1833: sensitive_data.host_certificates[i] = NULL;
1834:
1835: for (i = 0; i < options.num_host_cert_files; i++) {
1.430 djm 1836: if (options.host_cert_files[i] == NULL)
1837: continue;
1.512 markus 1838: if ((r = sshkey_load_public(options.host_cert_files[i],
1839: &key, NULL)) != 0) {
1.564 djm 1840: error_r(r, "Could not load host certificate \"%s\"",
1841: options.host_cert_files[i]);
1.373 djm 1842: continue;
1843: }
1.512 markus 1844: if (!sshkey_is_cert(key)) {
1.373 djm 1845: error("Certificate file is not a certificate: %s",
1846: options.host_cert_files[i]);
1.512 markus 1847: sshkey_free(key);
1.373 djm 1848: continue;
1849: }
1850: /* Find matching private key */
1851: for (j = 0; j < options.num_host_key_files; j++) {
1.512 markus 1852: if (sshkey_equal_public(key,
1.575 djm 1853: sensitive_data.host_pubkeys[j])) {
1.373 djm 1854: sensitive_data.host_certificates[j] = key;
1855: break;
1856: }
1857: }
1858: if (j >= options.num_host_key_files) {
1859: error("No matching private key for certificate: %s",
1860: options.host_cert_files[i]);
1.512 markus 1861: sshkey_free(key);
1.373 djm 1862: continue;
1863: }
1864: sensitive_data.host_certificates[j] = key;
1.493 djm 1865: debug("host certificate: #%u type %d %s", j, key->type,
1.512 markus 1866: sshkey_type(key));
1.373 djm 1867: }
1.426 markus 1868:
1.244 markus 1869: if (use_privsep) {
1870: struct stat st;
1871:
1.327 deraadt 1872: if (getpwnam(SSH_PRIVSEP_USER) == NULL)
1.244 markus 1873: fatal("Privilege separation user %s does not exist",
1874: SSH_PRIVSEP_USER);
1.500 djm 1875: endpwent();
1.244 markus 1876: if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) ||
1877: (S_ISDIR(st.st_mode) == 0))
1878: fatal("Missing privilege separation directory: %s",
1.247 stevesk 1879: _PATH_PRIVSEP_CHROOT_DIR);
1880: if (st.st_uid != 0 || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)
1.262 markus 1881: fatal("%s must be owned by root and not group or "
1882: "world-writable.", _PATH_PRIVSEP_CHROOT_DIR);
1.358 dtucker 1883: }
1884:
1.597 djm 1885: if (test_flag > 1)
1886: print_config(ssh, connection_info);
1.203 stevesk 1887:
1888: /* Configuration looks good, so exit if in test mode. */
1889: if (test_flag)
1890: exit(0);
1.108 markus 1891:
1.294 djm 1892: if (rexec_flag) {
1.493 djm 1893: if (rexec_argc < 0)
1894: fatal("rexec_argc %d < 0", rexec_argc);
1.329 djm 1895: rexec_argv = xcalloc(rexec_argc + 2, sizeof(char *));
1.493 djm 1896: for (i = 0; i < (u_int)rexec_argc; i++) {
1.294 djm 1897: debug("rexec_argv[%d]='%s'", i, saved_argv[i]);
1898: rexec_argv[i] = saved_argv[i];
1899: }
1900: rexec_argv[rexec_argc] = "-R";
1901: rexec_argv[rexec_argc + 1] = NULL;
1902: }
1.545 djm 1903: listener_proctitle = prepare_proctitle(ac, av);
1.362 dtucker 1904:
1905: /* Ensure that umask disallows at least group and world write */
1906: new_umask = umask(0077) | 0022;
1907: (void) umask(new_umask);
1.294 djm 1908:
1.108 markus 1909: /* Initialize the log (it is reinitialized below in case we forked). */
1.306 dtucker 1910: if (debug_flag && (!inetd_flag || rexeced_flag))
1.64 markus 1911: log_stderr = 1;
1.563 djm 1912: log_init(__progname, options.log_level,
1913: options.log_facility, log_stderr);
1914: for (i = 0; i < options.num_log_verbose; i++)
1915: log_verbose_add(options.log_verbose[i]);
1.64 markus 1916:
1.108 markus 1917: /*
1.478 dtucker 1918: * If not in debugging mode, not started from inetd and not already
1919: * daemonized (eg re-exec via SIGHUP), disconnect from the controlling
1920: * terminal, and fork. The original process exits.
1.108 markus 1921: */
1.478 dtucker 1922: already_daemon = daemonized();
1923: if (!(debug_flag || inetd_flag || no_daemon_flag || already_daemon)) {
1.345 djm 1924:
1.537 deraadt 1925: if (daemon(0, 0) == -1)
1.64 markus 1926: fatal("daemon() failed: %.200s", strerror(errno));
1927:
1.477 dtucker 1928: disconnect_controlling_tty();
1.64 markus 1929: }
1930: /* Reinitialize the log (because of the fork above). */
1.138 markus 1931: log_init(__progname, options.log_level, options.log_facility, log_stderr);
1.64 markus 1932:
1.572 djm 1933: /*
1934: * Chdir to the root directory so that the current disk can be
1935: * unmounted if desired.
1936: */
1.401 dtucker 1937: if (chdir("/") == -1)
1938: error("chdir(\"/\"): %s", strerror(errno));
1.217 deraadt 1939:
1.178 markus 1940: /* ignore SIGPIPE */
1.544 dtucker 1941: ssh_signal(SIGPIPE, SIG_IGN);
1.64 markus 1942:
1.345 djm 1943: /* Get a connection, either from inetd or a listening TCP socket */
1.64 markus 1944: if (inetd_flag) {
1.345 djm 1945: server_accept_inetd(&sock_in, &sock_out);
1.64 markus 1946: } else {
1.345 djm 1947: server_listen();
1.75 markus 1948:
1.544 dtucker 1949: ssh_signal(SIGHUP, sighup_handler);
1950: ssh_signal(SIGCHLD, main_sigchld_handler);
1951: ssh_signal(SIGTERM, sigterm_handler);
1952: ssh_signal(SIGQUIT, sigterm_handler);
1.201 markus 1953:
1.345 djm 1954: /*
1955: * Write out the pid file after the sigterm handler
1956: * is setup and the listen sockets are bound
1957: */
1.479 dtucker 1958: if (options.pid_file != NULL && !debug_flag) {
1.345 djm 1959: FILE *f = fopen(options.pid_file, "w");
1.201 markus 1960:
1.270 djm 1961: if (f == NULL) {
1962: error("Couldn't create pid file \"%s\": %s",
1963: options.pid_file, strerror(errno));
1964: } else {
1.245 mpech 1965: fprintf(f, "%ld\n", (long) getpid());
1.64 markus 1966: fclose(f);
1967: }
1968: }
1969:
1.345 djm 1970: /* Accept a connection and return in a forked child */
1971: server_accept_loop(&sock_in, &sock_out,
1972: &newsock, config_s);
1.1 deraadt 1973: }
1974:
1.64 markus 1975: /* This is the child processing a new connection. */
1.288 markus 1976: setproctitle("%s", "[accepted]");
1.294 djm 1977:
1.300 markus 1978: /*
1979: * Create a new session and process group since the 4.4BSD
1980: * setlogin() affects the entire process group. We don't
1981: * want the child to be able to affect the parent.
1982: */
1.537 deraadt 1983: if (!debug_flag && !inetd_flag && setsid() == -1)
1.300 markus 1984: error("setsid: %.100s", strerror(errno));
1985:
1.294 djm 1986: if (rexec_flag) {
1.296 djm 1987: debug("rexec start in %d out %d newsock %d pipe %d sock %d",
1988: sock_in, sock_out, newsock, startup_pipe, config_s[0]);
1.598 dtucker 1989: if (dup2(newsock, STDIN_FILENO) == -1)
1990: debug3_f("dup2 stdin: %s", strerror(errno));
1991: if (dup2(STDIN_FILENO, STDOUT_FILENO) == -1)
1992: debug3_f("dup2 stdout: %s", strerror(errno));
1.294 djm 1993: if (startup_pipe == -1)
1.296 djm 1994: close(REEXEC_STARTUP_PIPE_FD);
1.407 djm 1995: else if (startup_pipe != REEXEC_STARTUP_PIPE_FD) {
1.598 dtucker 1996: if (dup2(startup_pipe, REEXEC_STARTUP_PIPE_FD) == -1)
1997: debug3_f("dup2 startup_p: %s", strerror(errno));
1.407 djm 1998: close(startup_pipe);
1999: startup_pipe = REEXEC_STARTUP_PIPE_FD;
2000: }
1.294 djm 2001:
1.598 dtucker 2002: if (dup2(config_s[1], REEXEC_CONFIG_PASS_FD) == -1)
2003: debug3_f("dup2 config_s: %s", strerror(errno));
1.294 djm 2004: close(config_s[1]);
1.296 djm 2005:
1.559 markus 2006: ssh_signal(SIGHUP, SIG_IGN); /* avoid reset to SIG_DFL */
1.294 djm 2007: execv(rexec_argv[0], rexec_argv);
2008:
2009: /* Reexec has failed, fall back and continue */
2010: error("rexec of %s failed: %s", rexec_argv[0], strerror(errno));
1.296 djm 2011: recv_rexec_state(REEXEC_CONFIG_PASS_FD, NULL);
1.294 djm 2012: log_init(__progname, options.log_level,
2013: options.log_facility, log_stderr);
2014:
2015: /* Clean up fds */
1.296 djm 2016: close(REEXEC_CONFIG_PASS_FD);
2017: newsock = sock_out = sock_in = dup(STDIN_FILENO);
1.562 djm 2018: if (stdfd_devnull(1, 1, 0) == -1)
1.564 djm 2019: error_f("stdfd_devnull failed");
1.296 djm 2020: debug("rexec cleanup in %d out %d newsock %d pipe %d sock %d",
2021: sock_in, sock_out, newsock, startup_pipe, config_s[0]);
1.294 djm 2022: }
1.372 djm 2023:
2024: /* Executed child processes don't need these. */
2025: fcntl(sock_out, F_SETFD, FD_CLOEXEC);
2026: fcntl(sock_in, F_SETFD, FD_CLOEXEC);
1.64 markus 2027:
1.551 dtucker 2028: /* We will not restart on SIGHUP since it no longer makes sense. */
1.544 dtucker 2029: ssh_signal(SIGALRM, SIG_DFL);
2030: ssh_signal(SIGHUP, SIG_DFL);
2031: ssh_signal(SIGTERM, SIG_DFL);
2032: ssh_signal(SIGQUIT, SIG_DFL);
2033: ssh_signal(SIGCHLD, SIG_DFL);
1.150 markus 2034:
1.66 markus 2035: /*
2036: * Register our connection. This turns encryption off because we do
2037: * not have a key.
2038: */
1.525 djm 2039: if ((ssh = ssh_packet_set_connection(NULL, sock_in, sock_out)) == NULL)
2040: fatal("Unable to create connection");
1.527 djm 2041: the_active_state = ssh;
1.525 djm 2042: ssh_packet_set_server(ssh);
1.492 djm 2043:
1.466 djm 2044: check_ip_options(ssh);
1.309 djm 2045:
1.492 djm 2046: /* Prepare the channels layer */
2047: channel_init_channels(ssh);
2048: channel_set_af(ssh, options.address_family);
1.595 djm 2049: process_channel_timeouts(ssh, &options);
1.492 djm 2050: process_permitopen(ssh, &options);
2051:
1.309 djm 2052: /* Set SO_KEEPALIVE if requested. */
1.525 djm 2053: if (options.tcp_keep_alive && ssh_packet_connection_is_on_socket(ssh) &&
1.537 deraadt 2054: setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) == -1)
1.309 djm 2055: error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1.1 deraadt 2056:
1.466 djm 2057: if ((remote_port = ssh_remote_port(ssh)) < 0) {
2058: debug("ssh_remote_port failed");
1.310 markus 2059: cleanup_exit(255);
2060: }
1.316 dtucker 2061:
2062: /*
1.331 markus 2063: * The rest of the code depends on the fact that
1.466 djm 2064: * ssh_remote_ipaddr() caches the remote ip, even if
1.331 markus 2065: * the socket goes away.
2066: */
1.466 djm 2067: remote_ip = ssh_remote_ipaddr(ssh);
1.209 markus 2068:
1.496 djm 2069: rdomain = ssh_packet_rdomain_in(ssh);
2070:
1.64 markus 2071: /* Log the connection. */
1.447 dtucker 2072: laddr = get_local_ipaddr(sock_in);
1.497 djm 2073: verbose("Connection from %s port %d on %s port %d%s%s%s",
1.496 djm 2074: remote_ip, remote_port, laddr, ssh_local_port(ssh),
1.497 djm 2075: rdomain == NULL ? "" : " rdomain \"",
2076: rdomain == NULL ? "" : rdomain,
2077: rdomain == NULL ? "" : "\"");
1.447 dtucker 2078: free(laddr);
1.1 deraadt 2079:
1.66 markus 2080: /*
1.317 djm 2081: * We don't want to listen forever unless the other side
1.66 markus 2082: * successfully authenticates itself. So we set up an alarm which is
2083: * cleared after successful authentication. A limit of zero
1.317 djm 2084: * indicates no limit. Note that we don't set the alarm in debugging
1.66 markus 2085: * mode; it is just annoying to have the server exit just when you
2086: * are about to discover the bug.
2087: */
1.544 dtucker 2088: ssh_signal(SIGALRM, grace_alarm_handler);
1.64 markus 2089: if (!debug_flag)
2090: alarm(options.login_grace_time);
2091:
1.552 djm 2092: if ((r = kex_exchange_identification(ssh, -1,
2093: options.version_addendum)) != 0)
2094: sshpkt_fatal(ssh, r, "banner exchange");
1.520 djm 2095:
1.525 djm 2096: ssh_packet_set_nonblocking(ssh);
1.1 deraadt 2097:
1.278 markus 2098: /* allocate authentication context */
1.329 djm 2099: authctxt = xcalloc(1, sizeof(*authctxt));
1.525 djm 2100: ssh->authctxt = authctxt;
1.278 markus 2101:
2102: /* XXX global for cleanup, access from other modules */
2103: the_authctxt = authctxt;
1.506 djm 2104:
2105: /* Set default key authentication options */
2106: if ((auth_opts = sshauthopt_new_with_keys_defaults()) == NULL)
2107: fatal("allocation failed");
1.278 markus 2108:
1.307 otto 2109: /* prepare buffer to collect messages to display to user after login */
1.510 markus 2110: if ((loginmsg = sshbuf_new()) == NULL)
1.564 djm 2111: fatal_f("sshbuf_new failed");
1.374 dtucker 2112: auth_debug_reset();
1.307 otto 2113:
1.404 markus 2114: if (use_privsep) {
1.525 djm 2115: if (privsep_preauth(ssh) == 1)
1.237 markus 2116: goto authenticated;
1.472 markus 2117: } else if (have_agent) {
1.432 djm 2118: if ((r = ssh_get_authentication_socket(&auth_sock)) != 0) {
1.564 djm 2119: error_r(r, "Unable to get agent socket");
1.433 djm 2120: have_agent = 0;
1.432 djm 2121: }
2122: }
1.231 provos 2123:
1.77 markus 2124: /* perform the key exchange */
2125: /* authenticate user and start session */
1.525 djm 2126: do_ssh2_kex(ssh);
1.524 djm 2127: do_authentication2(ssh);
1.472 markus 2128:
1.237 markus 2129: /*
2130: * If we use privilege separation, the unprivileged child transfers
2131: * the current keystate and exits
2132: */
2133: if (use_privsep) {
1.527 djm 2134: mm_send_keystate(ssh, pmonitor);
1.525 djm 2135: ssh_packet_clear_keys(ssh);
1.231 provos 2136: exit(0);
1.237 markus 2137: }
1.231 provos 2138:
2139: authenticated:
1.318 djm 2140: /*
2141: * Cancel the alarm we set to limit the time taken for
2142: * authentication.
2143: */
2144: alarm(0);
1.544 dtucker 2145: ssh_signal(SIGALRM, SIG_DFL);
1.347 markus 2146: authctxt->authenticated = 1;
1.318 djm 2147: if (startup_pipe != -1) {
2148: close(startup_pipe);
2149: startup_pipe = -1;
2150: }
1.495 djm 2151:
2152: if (options.routing_domain != NULL)
2153: set_process_rdomain(ssh, options.routing_domain);
1.318 djm 2154:
1.234 markus 2155: /*
1.231 provos 2156: * In privilege separation, we fork another child and prepare
2157: * file descriptor passing.
2158: */
2159: if (use_privsep) {
1.525 djm 2160: privsep_postauth(ssh, authctxt);
1.237 markus 2161: /* the monitor process [priv] will not return */
1.231 provos 2162: }
1.360 dtucker 2163:
1.525 djm 2164: ssh_packet_set_timeout(ssh, options.client_alive_interval,
1.360 dtucker 2165: options.client_alive_count_max);
1.439 djm 2166:
2167: /* Try to send all our hostkeys to the client */
1.492 djm 2168: notify_hostkeys(ssh);
1.230 provos 2169:
1.278 markus 2170: /* Start session. */
1.492 djm 2171: do_authenticated(ssh, authctxt);
1.230 provos 2172:
1.64 markus 2173: /* The connection has been terminated. */
1.525 djm 2174: ssh_packet_get_bytes(ssh, &ibytes, &obytes);
1.381 djm 2175: verbose("Transferred: sent %llu, received %llu bytes",
2176: (unsigned long long)obytes, (unsigned long long)ibytes);
1.364 markus 2177:
2178: verbose("Closing connection to %.500s port %d", remote_ip, remote_port);
1.525 djm 2179: ssh_packet_close(ssh);
1.231 provos 2180:
2181: if (use_privsep)
2182: mm_terminate();
2183:
1.64 markus 2184: exit(0);
1.1 deraadt 2185: }
1.98 markus 2186:
1.435 markus 2187: int
1.527 djm 2188: sshd_hostkey_sign(struct ssh *ssh, struct sshkey *privkey,
2189: struct sshkey *pubkey, u_char **signature, size_t *slenp,
2190: const u_char *data, size_t dlen, const char *alg)
1.404 markus 2191: {
1.432 djm 2192: int r;
2193:
1.527 djm 2194: if (use_privsep) {
2195: if (privkey) {
2196: if (mm_sshkey_sign(ssh, privkey, signature, slenp,
1.561 djm 2197: data, dlen, alg, options.sk_provider, NULL,
1.542 djm 2198: ssh->compat) < 0)
1.564 djm 2199: fatal_f("privkey sign failed");
1.527 djm 2200: } else {
2201: if (mm_sshkey_sign(ssh, pubkey, signature, slenp,
1.561 djm 2202: data, dlen, alg, options.sk_provider, NULL,
1.542 djm 2203: ssh->compat) < 0)
1.564 djm 2204: fatal_f("pubkey sign failed");
1.527 djm 2205: }
1.404 markus 2206: } else {
1.527 djm 2207: if (privkey) {
2208: if (sshkey_sign(privkey, signature, slenp, data, dlen,
1.561 djm 2209: alg, options.sk_provider, NULL, ssh->compat) < 0)
1.564 djm 2210: fatal_f("privkey sign failed");
1.527 djm 2211: } else {
2212: if ((r = ssh_agent_sign(auth_sock, pubkey,
2213: signature, slenp, data, dlen, alg,
2214: ssh->compat)) != 0) {
1.564 djm 2215: fatal_fr(r, "agent sign failed");
1.527 djm 2216: }
2217: }
1.404 markus 2218: }
1.435 markus 2219: return 0;
1.404 markus 2220: }
2221:
1.452 djm 2222: /* SSH2 key exchange */
1.200 itojun 2223: static void
1.525 djm 2224: do_ssh2_kex(struct ssh *ssh)
1.98 markus 2225: {
1.599 ! dtucker 2226: char *hkalgs = NULL, *myproposal[PROPOSAL_MAX];
! 2227: const char *compression = NULL;
1.435 markus 2228: struct kex *kex;
1.437 markus 2229: int r;
1.102 markus 2230:
1.400 dtucker 2231: if (options.rekey_limit || options.rekey_interval)
1.525 djm 2232: ssh_packet_set_rekey_limits(ssh, options.rekey_limit,
1.481 dtucker 2233: options.rekey_interval);
1.327 deraadt 2234:
1.599 ! dtucker 2235: if (options.compression == COMP_NONE)
! 2236: compression = "none";
! 2237: hkalgs = list_hostkey_types();
! 2238:
! 2239: kex_proposal_populate_entries(ssh, myproposal, options.kex_algorithms,
! 2240: options.ciphers, options.macs, compression, hkalgs);
! 2241:
! 2242: free(hkalgs);
1.134 markus 2243:
1.189 markus 2244: /* start key exchange */
1.525 djm 2245: if ((r = kex_setup(ssh, myproposal)) != 0)
1.564 djm 2246: fatal_r(r, "kex_setup");
1.525 djm 2247: kex = ssh->kex;
1.426 markus 2248: #ifdef WITH_OPENSSL
1.532 djm 2249: kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_server;
2250: kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_server;
2251: kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_server;
2252: kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_server;
2253: kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_server;
1.263 markus 2254: kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1.324 djm 2255: kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1.532 djm 2256: kex->kex[KEX_ECDH_SHA2] = kex_gen_server;
1.426 markus 2257: #endif
1.532 djm 2258: kex->kex[KEX_C25519_SHA256] = kex_gen_server;
1.566 djm 2259: kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_server;
1.373 djm 2260: kex->load_host_public_key=&get_hostkey_public_by_type;
2261: kex->load_host_private_key=&get_hostkey_private_by_type;
1.231 provos 2262: kex->host_key_index=&get_hostkey_index;
1.404 markus 2263: kex->sign = sshd_hostkey_sign;
1.189 markus 2264:
1.525 djm 2265: ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &kex->done);
1.129 provos 2266:
2267: #ifdef DEBUG_KEXDH
2268: /* send 1st encrypted/maced/compressed message */
1.553 djm 2269: if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2270: (r = sshpkt_put_cstring(ssh, "markus")) != 0 ||
2271: (r = sshpkt_send(ssh)) != 0 ||
2272: (r = ssh_packet_write_wait(ssh)) != 0)
1.564 djm 2273: fatal_fr(r, "send test");
1.129 provos 2274: #endif
1.599 ! dtucker 2275: kex_proposal_free_entries(myproposal);
1.186 markus 2276: debug("KEX done");
1.278 markus 2277: }
2278:
2279: /* server specific fatal cleanup */
2280: void
2281: cleanup_exit(int i)
2282: {
1.527 djm 2283: if (the_active_state != NULL && the_authctxt != NULL) {
2284: do_cleanup(the_active_state, the_authctxt);
1.423 djm 2285: if (use_privsep && privsep_is_preauth &&
2286: pmonitor != NULL && pmonitor->m_pid > 1) {
1.386 djm 2287: debug("Killing privsep child %d", pmonitor->m_pid);
2288: if (kill(pmonitor->m_pid, SIGKILL) != 0 &&
1.564 djm 2289: errno != ESRCH) {
2290: error_f("kill(%d): %s", pmonitor->m_pid,
2291: strerror(errno));
2292: }
1.386 djm 2293: }
2294: }
1.278 markus 2295: _exit(i);
1.1 deraadt 2296: }
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