1 /* $OpenBSD: sshd-session.c,v 1.3 2024/06/06 17:15:25 djm Exp $ */
2 /*
3 * SSH2 implementation:
4 * Privilege Separation:
5 *
6 * Copyright (c) 2000, 2001, 2002 Markus Friedl. All rights reserved.
7 * Copyright (c) 2002 Niels Provos. All rights reserved.
8 *
9 * Redistribution and use in source and binary forms, with or without
10 * modification, are permitted provided that the following conditions
11 * are met:
12 * 1. Redistributions of source code must retain the above copyright
13 * notice, this list of conditions and the following disclaimer.
14 * 2. Redistributions in binary form must reproduce the above copyright
15 * notice, this list of conditions and the following disclaimer in the
16 * documentation and/or other materials provided with the distribution.
17 *
18 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
19 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
20 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
21 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
22 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
23 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
24 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
25 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
26 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
27 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
28 */
29
30 #include <sys/types.h>
31 #include <sys/ioctl.h>
32 #include <sys/wait.h>
33 #include <sys/tree.h>
34 #include <sys/stat.h>
35 #include <sys/socket.h>
36 #include <sys/time.h>
37 #include <sys/queue.h>
38
39 #include <errno.h>
40 #include <fcntl.h>
41 #include <netdb.h>
42 #include <paths.h>
43 #include <pwd.h>
44 #include <signal.h>
45 #include <stdio.h>
46 #include <stdlib.h>
47 #include <string.h>
48 #include <stdarg.h>
49 #include <unistd.h>
50 #include <limits.h>
51
52 #ifdef WITH_OPENSSL
53 #include <openssl/bn.h>
54 #include <openssl/evp.h>
55 #endif
56
57 #include "xmalloc.h"
58 #include "ssh.h"
59 #include "ssh2.h"
60 #include "sshpty.h"
61 #include "packet.h"
62 #include "log.h"
63 #include "sshbuf.h"
64 #include "misc.h"
65 #include "match.h"
66 #include "servconf.h"
67 #include "uidswap.h"
68 #include "compat.h"
69 #include "cipher.h"
70 #include "digest.h"
71 #include "sshkey.h"
72 #include "kex.h"
73 #include "authfile.h"
74 #include "pathnames.h"
75 #include "atomicio.h"
76 #include "canohost.h"
77 #include "hostfile.h"
78 #include "auth.h"
79 #include "authfd.h"
80 #include "msg.h"
81 #include "dispatch.h"
82 #include "channels.h"
83 #include "session.h"
84 #include "monitor.h"
85 #ifdef GSSAPI
86 #include "ssh-gss.h"
87 #endif
88 #include "monitor_wrap.h"
89 #include "ssh-sandbox.h"
90 #include "auth-options.h"
91 #include "version.h"
92 #include "ssherr.h"
93 #include "sk-api.h"
94 #include "srclimit.h"
95 #include "dh.h"
96
97 /* Re-exec fds */
98 #define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1)
99 #define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2)
100 #define REEXEC_CONFIG_PASS_FD (STDERR_FILENO + 3)
101 #define REEXEC_MIN_FREE_FD (STDERR_FILENO + 4)
102
103 extern char *__progname;
104
105 /* Server configuration options. */
106 ServerOptions options;
107
108 /* Name of the server configuration file. */
109 char *config_file_name = _PATH_SERVER_CONFIG_FILE;
110
111 /*
112 * Debug mode flag. This can be set on the command line. If debug
113 * mode is enabled, extra debugging output will be sent to the system
114 * log, the daemon will not go to background, and will exit after processing
115 * the first connection.
116 */
117 int debug_flag = 0;
118
119 /* Flag indicating that the daemon is being started from inetd. */
120 static int inetd_flag = 0;
121
122 /* debug goes to stderr unless inetd_flag is set */
123 static int log_stderr = 0;
124
125 /* Saved arguments to main(). */
126 static char **saved_argv;
127
128 /* Daemon's agent connection */
129 int auth_sock = -1;
130 static int have_agent = 0;
131
132 /*
133 * Any really sensitive data in the application is contained in this
134 * structure. The idea is that this structure could be locked into memory so
135 * that the pages do not get written into swap. However, there are some
136 * problems. The private key contains BIGNUMs, and we do not (in principle)
137 * have access to the internals of them, and locking just the structure is
138 * not very useful. Currently, memory locking is not implemented.
139 */
140 struct {
141 u_int num_hostkeys;
142 struct sshkey **host_keys; /* all private host keys */
143 struct sshkey **host_pubkeys; /* all public host keys */
144 struct sshkey **host_certificates; /* all public host certificates */
145 } sensitive_data;
146
147 /* record remote hostname or ip */
148 u_int utmp_len = HOST_NAME_MAX+1;
149
150 static int startup_pipe = -1; /* in child */
151
152 /* variables used for privilege separation */
153 struct monitor *pmonitor = NULL;
154 int privsep_is_preauth = 1;
155
156 /* global connection state and authentication contexts */
157 Authctxt *the_authctxt = NULL;
158 struct ssh *the_active_state;
159
160 /* global key/cert auth options. XXX move to permanent ssh->authctxt? */
161 struct sshauthopt *auth_opts = NULL;
162
163 /* sshd_config buffer */
164 struct sshbuf *cfg;
165
166 /* Included files from the configuration file */
167 struct include_list includes = TAILQ_HEAD_INITIALIZER(includes);
168
169 /* message to be displayed after login */
170 struct sshbuf *loginmsg;
171
172 /* Prototypes for various functions defined later in this file. */
173 void destroy_sensitive_data(void);
174 void demote_sensitive_data(void);
175 static void do_ssh2_kex(struct ssh *);
176
177 /*
178 * Signal handler for the alarm after the login grace period has expired.
179 */
180 static void
grace_alarm_handler(int sig)181 grace_alarm_handler(int sig)
182 {
183 /*
184 * Try to kill any processes that we have spawned, E.g. authorized
185 * keys command helpers or privsep children.
186 */
187 if (getpgid(0) == getpid()) {
188 ssh_signal(SIGTERM, SIG_IGN);
189 kill(0, SIGTERM);
190 }
191 _exit(EXIT_LOGIN_GRACE);
192 }
193
194 /* Destroy the host and server keys. They will no longer be needed. */
195 void
destroy_sensitive_data(void)196 destroy_sensitive_data(void)
197 {
198 u_int i;
199
200 for (i = 0; i < options.num_host_key_files; i++) {
201 if (sensitive_data.host_keys[i]) {
202 sshkey_free(sensitive_data.host_keys[i]);
203 sensitive_data.host_keys[i] = NULL;
204 }
205 if (sensitive_data.host_certificates[i]) {
206 sshkey_free(sensitive_data.host_certificates[i]);
207 sensitive_data.host_certificates[i] = NULL;
208 }
209 }
210 }
211
212 /* Demote private to public keys for network child */
213 void
demote_sensitive_data(void)214 demote_sensitive_data(void)
215 {
216 struct sshkey *tmp;
217 u_int i;
218 int r;
219
220 for (i = 0; i < options.num_host_key_files; i++) {
221 if (sensitive_data.host_keys[i]) {
222 if ((r = sshkey_from_private(
223 sensitive_data.host_keys[i], &tmp)) != 0)
224 fatal_r(r, "could not demote host %s key",
225 sshkey_type(sensitive_data.host_keys[i]));
226 sshkey_free(sensitive_data.host_keys[i]);
227 sensitive_data.host_keys[i] = tmp;
228 }
229 /* Certs do not need demotion */
230 }
231 }
232
233 static void
privsep_preauth_child(void)234 privsep_preauth_child(void)
235 {
236 gid_t gidset[1];
237 struct passwd *pw;
238
239 /* Enable challenge-response authentication for privilege separation */
240 privsep_challenge_enable();
241
242 #ifdef GSSAPI
243 /* Cache supported mechanism OIDs for later use */
244 ssh_gssapi_prepare_supported_oids();
245 #endif
246
247 /* Demote the private keys to public keys. */
248 demote_sensitive_data();
249
250 /* Demote the child */
251 if (getuid() == 0 || geteuid() == 0) {
252 if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
253 fatal("Privilege separation user %s does not exist",
254 SSH_PRIVSEP_USER);
255 pw = pwcopy(pw); /* Ensure mutable */
256 endpwent();
257 freezero(pw->pw_passwd, strlen(pw->pw_passwd));
258
259 /* Change our root directory */
260 if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1)
261 fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR,
262 strerror(errno));
263 if (chdir("/") == -1)
264 fatal("chdir(\"/\"): %s", strerror(errno));
265
266 /*
267 * Drop our privileges
268 * NB. Can't use setusercontext() after chroot.
269 */
270 debug3("privsep user:group %u:%u", (u_int)pw->pw_uid,
271 (u_int)pw->pw_gid);
272 gidset[0] = pw->pw_gid;
273 if (setgroups(1, gidset) == -1)
274 fatal("setgroups: %.100s", strerror(errno));
275 permanently_set_uid(pw);
276 }
277 }
278
279 static int
privsep_preauth(struct ssh * ssh)280 privsep_preauth(struct ssh *ssh)
281 {
282 int status, r;
283 pid_t pid;
284 struct ssh_sandbox *box = NULL;
285
286 /* Set up unprivileged child process to deal with network data */
287 pmonitor = monitor_init();
288 /* Store a pointer to the kex for later rekeying */
289 pmonitor->m_pkex = &ssh->kex;
290
291 box = ssh_sandbox_init();
292 pid = fork();
293 if (pid == -1) {
294 fatal("fork of unprivileged child failed");
295 } else if (pid != 0) {
296 debug2("Network child is on pid %ld", (long)pid);
297
298 pmonitor->m_pid = pid;
299 if (have_agent) {
300 r = ssh_get_authentication_socket(&auth_sock);
301 if (r != 0) {
302 error_r(r, "Could not get agent socket");
303 have_agent = 0;
304 }
305 }
306 if (box != NULL)
307 ssh_sandbox_parent_preauth(box, pid);
308 monitor_child_preauth(ssh, pmonitor);
309
310 /* Wait for the child's exit status */
311 while (waitpid(pid, &status, 0) == -1) {
312 if (errno == EINTR)
313 continue;
314 pmonitor->m_pid = -1;
315 fatal_f("waitpid: %s", strerror(errno));
316 }
317 privsep_is_preauth = 0;
318 pmonitor->m_pid = -1;
319 if (WIFEXITED(status)) {
320 if (WEXITSTATUS(status) != 0)
321 fatal_f("preauth child exited with status %d",
322 WEXITSTATUS(status));
323 } else if (WIFSIGNALED(status))
324 fatal_f("preauth child terminated by signal %d",
325 WTERMSIG(status));
326 if (box != NULL)
327 ssh_sandbox_parent_finish(box);
328 return 1;
329 } else {
330 /* child */
331 close(pmonitor->m_sendfd);
332 close(pmonitor->m_log_recvfd);
333
334 /* Arrange for logging to be sent to the monitor */
335 set_log_handler(mm_log_handler, pmonitor);
336
337 privsep_preauth_child();
338 setproctitle("%s", "[net]");
339 if (box != NULL)
340 ssh_sandbox_child(box);
341
342 return 0;
343 }
344 }
345
346 static void
privsep_postauth(struct ssh * ssh,Authctxt * authctxt)347 privsep_postauth(struct ssh *ssh, Authctxt *authctxt)
348 {
349 /* New socket pair */
350 monitor_reinit(pmonitor);
351
352 pmonitor->m_pid = fork();
353 if (pmonitor->m_pid == -1)
354 fatal("fork of unprivileged child failed");
355 else if (pmonitor->m_pid != 0) {
356 verbose("User child is on pid %ld", (long)pmonitor->m_pid);
357 sshbuf_reset(loginmsg);
358 monitor_clear_keystate(ssh, pmonitor);
359 monitor_child_postauth(ssh, pmonitor);
360
361 /* NEVERREACHED */
362 exit(0);
363 }
364
365 /* child */
366
367 close(pmonitor->m_sendfd);
368 pmonitor->m_sendfd = -1;
369
370 /* Demote the private keys to public keys. */
371 demote_sensitive_data();
372
373 /* Drop privileges */
374 do_setusercontext(authctxt->pw);
375
376 /* It is safe now to apply the key state */
377 monitor_apply_keystate(ssh, pmonitor);
378
379 /*
380 * Tell the packet layer that authentication was successful, since
381 * this information is not part of the key state.
382 */
383 ssh_packet_set_authenticated(ssh);
384 }
385
386 static void
append_hostkey_type(struct sshbuf * b,const char * s)387 append_hostkey_type(struct sshbuf *b, const char *s)
388 {
389 int r;
390
391 if (match_pattern_list(s, options.hostkeyalgorithms, 0) != 1) {
392 debug3_f("%s key not permitted by HostkeyAlgorithms", s);
393 return;
394 }
395 if ((r = sshbuf_putf(b, "%s%s", sshbuf_len(b) > 0 ? "," : "", s)) != 0)
396 fatal_fr(r, "sshbuf_putf");
397 }
398
399 static char *
list_hostkey_types(void)400 list_hostkey_types(void)
401 {
402 struct sshbuf *b;
403 struct sshkey *key;
404 char *ret;
405 u_int i;
406
407 if ((b = sshbuf_new()) == NULL)
408 fatal_f("sshbuf_new failed");
409 for (i = 0; i < options.num_host_key_files; i++) {
410 key = sensitive_data.host_keys[i];
411 if (key == NULL)
412 key = sensitive_data.host_pubkeys[i];
413 if (key == NULL)
414 continue;
415 switch (key->type) {
416 case KEY_RSA:
417 /* for RSA we also support SHA2 signatures */
418 append_hostkey_type(b, "rsa-sha2-512");
419 append_hostkey_type(b, "rsa-sha2-256");
420 /* FALLTHROUGH */
421 case KEY_DSA:
422 case KEY_ECDSA:
423 case KEY_ED25519:
424 case KEY_ECDSA_SK:
425 case KEY_ED25519_SK:
426 case KEY_XMSS:
427 append_hostkey_type(b, sshkey_ssh_name(key));
428 break;
429 }
430 /* If the private key has a cert peer, then list that too */
431 key = sensitive_data.host_certificates[i];
432 if (key == NULL)
433 continue;
434 switch (key->type) {
435 case KEY_RSA_CERT:
436 /* for RSA we also support SHA2 signatures */
437 append_hostkey_type(b,
438 "rsa-sha2-512-cert-v01@openssh.com");
439 append_hostkey_type(b,
440 "rsa-sha2-256-cert-v01@openssh.com");
441 /* FALLTHROUGH */
442 case KEY_DSA_CERT:
443 case KEY_ECDSA_CERT:
444 case KEY_ED25519_CERT:
445 case KEY_ECDSA_SK_CERT:
446 case KEY_ED25519_SK_CERT:
447 case KEY_XMSS_CERT:
448 append_hostkey_type(b, sshkey_ssh_name(key));
449 break;
450 }
451 }
452 if ((ret = sshbuf_dup_string(b)) == NULL)
453 fatal_f("sshbuf_dup_string failed");
454 sshbuf_free(b);
455 debug_f("%s", ret);
456 return ret;
457 }
458
459 static struct sshkey *
get_hostkey_by_type(int type,int nid,int need_private,struct ssh * ssh)460 get_hostkey_by_type(int type, int nid, int need_private, struct ssh *ssh)
461 {
462 u_int i;
463 struct sshkey *key;
464
465 for (i = 0; i < options.num_host_key_files; i++) {
466 switch (type) {
467 case KEY_RSA_CERT:
468 case KEY_DSA_CERT:
469 case KEY_ECDSA_CERT:
470 case KEY_ED25519_CERT:
471 case KEY_ECDSA_SK_CERT:
472 case KEY_ED25519_SK_CERT:
473 case KEY_XMSS_CERT:
474 key = sensitive_data.host_certificates[i];
475 break;
476 default:
477 key = sensitive_data.host_keys[i];
478 if (key == NULL && !need_private)
479 key = sensitive_data.host_pubkeys[i];
480 break;
481 }
482 if (key == NULL || key->type != type)
483 continue;
484 switch (type) {
485 case KEY_ECDSA:
486 case KEY_ECDSA_SK:
487 case KEY_ECDSA_CERT:
488 case KEY_ECDSA_SK_CERT:
489 if (key->ecdsa_nid != nid)
490 continue;
491 /* FALLTHROUGH */
492 default:
493 return need_private ?
494 sensitive_data.host_keys[i] : key;
495 }
496 }
497 return NULL;
498 }
499
500 struct sshkey *
get_hostkey_public_by_type(int type,int nid,struct ssh * ssh)501 get_hostkey_public_by_type(int type, int nid, struct ssh *ssh)
502 {
503 return get_hostkey_by_type(type, nid, 0, ssh);
504 }
505
506 struct sshkey *
get_hostkey_private_by_type(int type,int nid,struct ssh * ssh)507 get_hostkey_private_by_type(int type, int nid, struct ssh *ssh)
508 {
509 return get_hostkey_by_type(type, nid, 1, ssh);
510 }
511
512 struct sshkey *
get_hostkey_by_index(int ind)513 get_hostkey_by_index(int ind)
514 {
515 if (ind < 0 || (u_int)ind >= options.num_host_key_files)
516 return (NULL);
517 return (sensitive_data.host_keys[ind]);
518 }
519
520 struct sshkey *
get_hostkey_public_by_index(int ind,struct ssh * ssh)521 get_hostkey_public_by_index(int ind, struct ssh *ssh)
522 {
523 if (ind < 0 || (u_int)ind >= options.num_host_key_files)
524 return (NULL);
525 return (sensitive_data.host_pubkeys[ind]);
526 }
527
528 int
get_hostkey_index(struct sshkey * key,int compare,struct ssh * ssh)529 get_hostkey_index(struct sshkey *key, int compare, struct ssh *ssh)
530 {
531 u_int i;
532
533 for (i = 0; i < options.num_host_key_files; i++) {
534 if (sshkey_is_cert(key)) {
535 if (key == sensitive_data.host_certificates[i] ||
536 (compare && sensitive_data.host_certificates[i] &&
537 sshkey_equal(key,
538 sensitive_data.host_certificates[i])))
539 return (i);
540 } else {
541 if (key == sensitive_data.host_keys[i] ||
542 (compare && sensitive_data.host_keys[i] &&
543 sshkey_equal(key, sensitive_data.host_keys[i])))
544 return (i);
545 if (key == sensitive_data.host_pubkeys[i] ||
546 (compare && sensitive_data.host_pubkeys[i] &&
547 sshkey_equal(key, sensitive_data.host_pubkeys[i])))
548 return (i);
549 }
550 }
551 return (-1);
552 }
553
554 /* Inform the client of all hostkeys */
555 static void
notify_hostkeys(struct ssh * ssh)556 notify_hostkeys(struct ssh *ssh)
557 {
558 struct sshbuf *buf;
559 struct sshkey *key;
560 u_int i, nkeys;
561 int r;
562 char *fp;
563
564 /* Some clients cannot cope with the hostkeys message, skip those. */
565 if (ssh->compat & SSH_BUG_HOSTKEYS)
566 return;
567
568 if ((buf = sshbuf_new()) == NULL)
569 fatal_f("sshbuf_new");
570 for (i = nkeys = 0; i < options.num_host_key_files; i++) {
571 key = get_hostkey_public_by_index(i, ssh);
572 if (key == NULL || key->type == KEY_UNSPEC ||
573 sshkey_is_cert(key))
574 continue;
575 fp = sshkey_fingerprint(key, options.fingerprint_hash,
576 SSH_FP_DEFAULT);
577 debug3_f("key %d: %s %s", i, sshkey_ssh_name(key), fp);
578 free(fp);
579 if (nkeys == 0) {
580 /*
581 * Start building the request when we find the
582 * first usable key.
583 */
584 if ((r = sshpkt_start(ssh, SSH2_MSG_GLOBAL_REQUEST)) != 0 ||
585 (r = sshpkt_put_cstring(ssh, "hostkeys-00@openssh.com")) != 0 ||
586 (r = sshpkt_put_u8(ssh, 0)) != 0) /* want reply */
587 sshpkt_fatal(ssh, r, "%s: start request", __func__);
588 }
589 /* Append the key to the request */
590 sshbuf_reset(buf);
591 if ((r = sshkey_putb(key, buf)) != 0)
592 fatal_fr(r, "couldn't put hostkey %d", i);
593 if ((r = sshpkt_put_stringb(ssh, buf)) != 0)
594 sshpkt_fatal(ssh, r, "%s: append key", __func__);
595 nkeys++;
596 }
597 debug3_f("sent %u hostkeys", nkeys);
598 if (nkeys == 0)
599 fatal_f("no hostkeys");
600 if ((r = sshpkt_send(ssh)) != 0)
601 sshpkt_fatal(ssh, r, "%s: send", __func__);
602 sshbuf_free(buf);
603 }
604
605 static void
usage(void)606 usage(void)
607 {
608 fprintf(stderr, "%s, %s\n", SSH_VERSION, SSH_OPENSSL_VERSION);
609 fprintf(stderr,
610 "usage: sshd [-46DdeGiqTtV] [-C connection_spec] [-c host_cert_file]\n"
611 " [-E log_file] [-f config_file] [-g login_grace_time]\n"
612 " [-h host_key_file] [-o option] [-p port] [-u len]\n"
613 );
614 exit(1);
615 }
616
617 static void
parse_hostkeys(struct sshbuf * hostkeys)618 parse_hostkeys(struct sshbuf *hostkeys)
619 {
620 int r;
621 u_int num_keys = 0;
622 struct sshkey *k;
623 struct sshbuf *kbuf;
624 const u_char *cp;
625 size_t len;
626
627 while (sshbuf_len(hostkeys) != 0) {
628 if (num_keys > 2048)
629 fatal_f("too many hostkeys");
630 sensitive_data.host_keys = xrecallocarray(
631 sensitive_data.host_keys, num_keys, num_keys + 1,
632 sizeof(*sensitive_data.host_pubkeys));
633 sensitive_data.host_pubkeys = xrecallocarray(
634 sensitive_data.host_pubkeys, num_keys, num_keys + 1,
635 sizeof(*sensitive_data.host_pubkeys));
636 sensitive_data.host_certificates = xrecallocarray(
637 sensitive_data.host_certificates, num_keys, num_keys + 1,
638 sizeof(*sensitive_data.host_certificates));
639 /* private key */
640 k = NULL;
641 if ((r = sshbuf_froms(hostkeys, &kbuf)) != 0)
642 fatal_fr(r, "extract privkey");
643 if (sshbuf_len(kbuf) != 0 &&
644 (r = sshkey_private_deserialize(kbuf, &k)) != 0)
645 fatal_fr(r, "parse pubkey");
646 sensitive_data.host_keys[num_keys] = k;
647 sshbuf_free(kbuf);
648 if (k)
649 debug2_f("privkey %u: %s", num_keys, sshkey_ssh_name(k));
650 /* public key */
651 k = NULL;
652 if ((r = sshbuf_get_string_direct(hostkeys, &cp, &len)) != 0)
653 fatal_fr(r, "extract pubkey");
654 if (len != 0 && (r = sshkey_from_blob(cp, len, &k)) != 0)
655 fatal_fr(r, "parse pubkey");
656 sensitive_data.host_pubkeys[num_keys] = k;
657 if (k)
658 debug2_f("pubkey %u: %s", num_keys, sshkey_ssh_name(k));
659 /* certificate */
660 k = NULL;
661 if ((r = sshbuf_get_string_direct(hostkeys, &cp, &len)) != 0)
662 fatal_fr(r, "extract pubkey");
663 if (len != 0 && (r = sshkey_from_blob(cp, len, &k)) != 0)
664 fatal_fr(r, "parse pubkey");
665 sensitive_data.host_certificates[num_keys] = k;
666 if (k)
667 debug2_f("cert %u: %s", num_keys, sshkey_ssh_name(k));
668 num_keys++;
669 }
670 sensitive_data.num_hostkeys = num_keys;
671 }
672
673 static void
recv_rexec_state(int fd,struct sshbuf * conf,uint64_t * timing_secretp)674 recv_rexec_state(int fd, struct sshbuf *conf, uint64_t *timing_secretp)
675 {
676 struct sshbuf *m, *inc, *hostkeys;
677 u_char *cp, ver;
678 size_t len;
679 int r;
680 struct include_item *item;
681
682 debug3_f("entering fd = %d", fd);
683
684 if ((m = sshbuf_new()) == NULL || (inc = sshbuf_new()) == NULL)
685 fatal_f("sshbuf_new failed");
686 if (ssh_msg_recv(fd, m) == -1)
687 fatal_f("ssh_msg_recv failed");
688 if ((r = sshbuf_get_u8(m, &ver)) != 0)
689 fatal_fr(r, "parse version");
690 if (ver != 0)
691 fatal_f("rexec version mismatch");
692 if ((r = sshbuf_get_string(m, &cp, &len)) != 0 || /* XXX _direct */
693 (r = sshbuf_get_u64(m, timing_secretp)) != 0 ||
694 (r = sshbuf_froms(m, &hostkeys)) != 0 ||
695 (r = sshbuf_get_stringb(m, inc)) != 0)
696 fatal_fr(r, "parse config");
697
698 if (conf != NULL && (r = sshbuf_put(conf, cp, len)))
699 fatal_fr(r, "sshbuf_put");
700
701 while (sshbuf_len(inc) != 0) {
702 item = xcalloc(1, sizeof(*item));
703 if ((item->contents = sshbuf_new()) == NULL)
704 fatal_f("sshbuf_new failed");
705 if ((r = sshbuf_get_cstring(inc, &item->selector, NULL)) != 0 ||
706 (r = sshbuf_get_cstring(inc, &item->filename, NULL)) != 0 ||
707 (r = sshbuf_get_stringb(inc, item->contents)) != 0)
708 fatal_fr(r, "parse includes");
709 TAILQ_INSERT_TAIL(&includes, item, entry);
710 }
711
712 parse_hostkeys(hostkeys);
713
714 free(cp);
715 sshbuf_free(m);
716 sshbuf_free(hostkeys);
717 sshbuf_free(inc);
718
719 debug3_f("done");
720 }
721
722 /*
723 * If IP options are supported, make sure there are none (log and
724 * return an error if any are found). Basically we are worried about
725 * source routing; it can be used to pretend you are somebody
726 * (ip-address) you are not. That itself may be "almost acceptable"
727 * under certain circumstances, but rhosts authentication is useless
728 * if source routing is accepted. Notice also that if we just dropped
729 * source routing here, the other side could use IP spoofing to do
730 * rest of the interaction and could still bypass security. So we
731 * exit here if we detect any IP options.
732 */
733 static void
check_ip_options(struct ssh * ssh)734 check_ip_options(struct ssh *ssh)
735 {
736 int sock_in = ssh_packet_get_connection_in(ssh);
737 struct sockaddr_storage from;
738 u_char opts[200];
739 socklen_t i, option_size = sizeof(opts), fromlen = sizeof(from);
740 char text[sizeof(opts) * 3 + 1];
741
742 memset(&from, 0, sizeof(from));
743 if (getpeername(sock_in, (struct sockaddr *)&from,
744 &fromlen) == -1)
745 return;
746 if (from.ss_family != AF_INET)
747 return;
748 /* XXX IPv6 options? */
749
750 if (getsockopt(sock_in, IPPROTO_IP, IP_OPTIONS, opts,
751 &option_size) >= 0 && option_size != 0) {
752 text[0] = '\0';
753 for (i = 0; i < option_size; i++)
754 snprintf(text + i*3, sizeof(text) - i*3,
755 " %2.2x", opts[i]);
756 fatal("Connection from %.100s port %d with IP opts: %.800s",
757 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), text);
758 }
759 return;
760 }
761
762 /* Set the routing domain for this process */
763 static void
set_process_rdomain(struct ssh * ssh,const char * name)764 set_process_rdomain(struct ssh *ssh, const char *name)
765 {
766 int rtable, ortable = getrtable();
767 const char *errstr;
768
769 if (name == NULL)
770 return; /* default */
771
772 if (strcmp(name, "%D") == 0) {
773 /* "expands" to routing domain of connection */
774 if ((name = ssh_packet_rdomain_in(ssh)) == NULL)
775 return;
776 }
777
778 rtable = (int)strtonum(name, 0, 255, &errstr);
779 if (errstr != NULL) /* Shouldn't happen */
780 fatal("Invalid routing domain \"%s\": %s", name, errstr);
781 if (rtable != ortable && setrtable(rtable) != 0)
782 fatal("Unable to set routing domain %d: %s",
783 rtable, strerror(errno));
784 debug_f("set routing domain %d (was %d)", rtable, ortable);
785 }
786
787 /*
788 * Main program for the daemon.
789 */
790 int
main(int ac,char ** av)791 main(int ac, char **av)
792 {
793 struct ssh *ssh = NULL;
794 extern char *optarg;
795 extern int optind;
796 int r, opt, on = 1, remote_port;
797 int sock_in = -1, sock_out = -1, rexeced_flag = 0, have_key = 0;
798 const char *remote_ip, *rdomain;
799 char *line, *laddr, *logfile = NULL;
800 u_int i;
801 u_int64_t ibytes, obytes;
802 mode_t new_umask;
803 Authctxt *authctxt;
804 struct connection_info *connection_info = NULL;
805 sigset_t sigmask;
806 uint64_t timing_secret = 0;
807
808 sigemptyset(&sigmask);
809 sigprocmask(SIG_SETMASK, &sigmask, NULL);
810
811 /* Save argv. */
812 saved_argv = av;
813
814 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
815 sanitise_stdfd();
816
817 /* Initialize configuration options to their default values. */
818 initialize_server_options(&options);
819
820 /* Parse command-line arguments. */
821 while ((opt = getopt(ac, av,
822 "C:E:b:c:f:g:h:k:o:p:u:46DGQRTdeiqrtV")) != -1) {
823 switch (opt) {
824 case '4':
825 options.address_family = AF_INET;
826 break;
827 case '6':
828 options.address_family = AF_INET6;
829 break;
830 case 'f':
831 config_file_name = optarg;
832 break;
833 case 'c':
834 servconf_add_hostcert("[command-line]", 0,
835 &options, optarg);
836 break;
837 case 'd':
838 if (debug_flag == 0) {
839 debug_flag = 1;
840 options.log_level = SYSLOG_LEVEL_DEBUG1;
841 } else if (options.log_level < SYSLOG_LEVEL_DEBUG3)
842 options.log_level++;
843 break;
844 case 'D':
845 /* ignore */
846 break;
847 case 'E':
848 logfile = optarg;
849 /* FALLTHROUGH */
850 case 'e':
851 log_stderr = 1;
852 break;
853 case 'i':
854 inetd_flag = 1;
855 break;
856 case 'r':
857 /* ignore */
858 break;
859 case 'R':
860 rexeced_flag = 1;
861 break;
862 case 'Q':
863 /* ignored */
864 break;
865 case 'q':
866 options.log_level = SYSLOG_LEVEL_QUIET;
867 break;
868 case 'b':
869 /* protocol 1, ignored */
870 break;
871 case 'p':
872 options.ports_from_cmdline = 1;
873 if (options.num_ports >= MAX_PORTS) {
874 fprintf(stderr, "too many ports.\n");
875 exit(1);
876 }
877 options.ports[options.num_ports++] = a2port(optarg);
878 if (options.ports[options.num_ports-1] <= 0) {
879 fprintf(stderr, "Bad port number.\n");
880 exit(1);
881 }
882 break;
883 case 'g':
884 if ((options.login_grace_time = convtime(optarg)) == -1) {
885 fprintf(stderr, "Invalid login grace time.\n");
886 exit(1);
887 }
888 break;
889 case 'k':
890 /* protocol 1, ignored */
891 break;
892 case 'h':
893 servconf_add_hostkey("[command-line]", 0,
894 &options, optarg, 1);
895 break;
896 case 't':
897 case 'T':
898 case 'G':
899 fatal("test/dump modes not supported");
900 break;
901 case 'C':
902 connection_info = server_get_connection_info(ssh, 0, 0);
903 if (parse_server_match_testspec(connection_info,
904 optarg) == -1)
905 exit(1);
906 break;
907 case 'u':
908 utmp_len = (u_int)strtonum(optarg, 0, HOST_NAME_MAX+1+1, NULL);
909 if (utmp_len > HOST_NAME_MAX+1) {
910 fprintf(stderr, "Invalid utmp length.\n");
911 exit(1);
912 }
913 break;
914 case 'o':
915 line = xstrdup(optarg);
916 if (process_server_config_line(&options, line,
917 "command-line", 0, NULL, NULL, &includes) != 0)
918 exit(1);
919 free(line);
920 break;
921 case 'V':
922 fprintf(stderr, "%s, %s\n",
923 SSH_VERSION, SSH_OPENSSL_VERSION);
924 exit(0);
925 default:
926 usage();
927 break;
928 }
929 }
930
931 /* Check that there are no remaining arguments. */
932 if (optind < ac) {
933 fprintf(stderr, "Extra argument %s.\n", av[optind]);
934 exit(1);
935 }
936
937 debug("sshd version %s, %s", SSH_VERSION, SSH_OPENSSL_VERSION);
938
939 if (!rexeced_flag)
940 fatal("sshd-session should not be executed directly");
941
942 closefrom(REEXEC_MIN_FREE_FD);
943
944 #ifdef WITH_OPENSSL
945 OpenSSL_add_all_algorithms();
946 #endif
947
948 /* If requested, redirect the logs to the specified logfile. */
949 if (logfile != NULL) {
950 char *cp, pid_s[32];
951
952 snprintf(pid_s, sizeof(pid_s), "%ld", (unsigned long)getpid());
953 cp = percent_expand(logfile,
954 "p", pid_s,
955 "P", "sshd-session",
956 (char *)NULL);
957 log_redirect_stderr_to(cp);
958 free(cp);
959 }
960
961 /*
962 * Force logging to stderr until we have loaded the private host
963 * key (unless started from inetd)
964 */
965 log_init(__progname,
966 options.log_level == SYSLOG_LEVEL_NOT_SET ?
967 SYSLOG_LEVEL_INFO : options.log_level,
968 options.log_facility == SYSLOG_FACILITY_NOT_SET ?
969 SYSLOG_FACILITY_AUTH : options.log_facility,
970 log_stderr || !inetd_flag || debug_flag);
971
972 debug("sshd version %s, %s", SSH_VERSION, SSH_OPENSSL_VERSION);
973
974 /* Fetch our configuration */
975 if ((cfg = sshbuf_new()) == NULL)
976 fatal("sshbuf_new config buf failed");
977 setproctitle("%s", "[rexeced]");
978 recv_rexec_state(REEXEC_CONFIG_PASS_FD, cfg, &timing_secret);
979 close(REEXEC_CONFIG_PASS_FD);
980 parse_server_config(&options, "rexec", cfg, &includes, NULL, 1);
981 /* Fill in default values for those options not explicitly set. */
982 fill_default_server_options(&options);
983 options.timing_secret = timing_secret;
984
985 if (!debug_flag) {
986 startup_pipe = dup(REEXEC_STARTUP_PIPE_FD);
987 close(REEXEC_STARTUP_PIPE_FD);
988 /*
989 * Signal parent that this child is at a point where
990 * they can go away if they have a SIGHUP pending.
991 */
992 (void)atomicio(vwrite, startup_pipe, "\0", 1);
993 }
994
995 /* Check that options are sensible */
996 if (options.authorized_keys_command_user == NULL &&
997 (options.authorized_keys_command != NULL &&
998 strcasecmp(options.authorized_keys_command, "none") != 0))
999 fatal("AuthorizedKeysCommand set without "
1000 "AuthorizedKeysCommandUser");
1001 if (options.authorized_principals_command_user == NULL &&
1002 (options.authorized_principals_command != NULL &&
1003 strcasecmp(options.authorized_principals_command, "none") != 0))
1004 fatal("AuthorizedPrincipalsCommand set without "
1005 "AuthorizedPrincipalsCommandUser");
1006
1007 /*
1008 * Check whether there is any path through configured auth methods.
1009 * Unfortunately it is not possible to verify this generally before
1010 * daemonisation in the presence of Match block, but this catches
1011 * and warns for trivial misconfigurations that could break login.
1012 */
1013 if (options.num_auth_methods != 0) {
1014 for (i = 0; i < options.num_auth_methods; i++) {
1015 if (auth2_methods_valid(options.auth_methods[i],
1016 1) == 0)
1017 break;
1018 }
1019 if (i >= options.num_auth_methods)
1020 fatal("AuthenticationMethods cannot be satisfied by "
1021 "enabled authentication methods");
1022 }
1023
1024 #ifdef WITH_OPENSSL
1025 if (options.moduli_file != NULL)
1026 dh_set_moduli_file(options.moduli_file);
1027 #endif
1028
1029 if (options.host_key_agent) {
1030 if (strcmp(options.host_key_agent, SSH_AUTHSOCKET_ENV_NAME))
1031 setenv(SSH_AUTHSOCKET_ENV_NAME,
1032 options.host_key_agent, 1);
1033 if ((r = ssh_get_authentication_socket(NULL)) == 0)
1034 have_agent = 1;
1035 else
1036 error_r(r, "Could not connect to agent \"%s\"",
1037 options.host_key_agent);
1038 }
1039
1040 if (options.num_host_key_files != sensitive_data.num_hostkeys) {
1041 fatal("internal error: hostkeys confused (config %u recvd %u)",
1042 options.num_host_key_files, sensitive_data.num_hostkeys);
1043 }
1044
1045 for (i = 0; i < options.num_host_key_files; i++) {
1046 if (sensitive_data.host_keys[i] != NULL ||
1047 (have_agent && sensitive_data.host_pubkeys[i] != NULL)) {
1048 have_key = 1;
1049 break;
1050 }
1051 }
1052 if (!have_key)
1053 fatal("internal error: monitor received no hostkeys");
1054
1055 /* Ensure that umask disallows at least group and world write */
1056 new_umask = umask(0077) | 0022;
1057 (void) umask(new_umask);
1058
1059 /* Initialize the log (it is reinitialized below in case we forked). */
1060 if (debug_flag)
1061 log_stderr = 1;
1062 log_init(__progname, options.log_level,
1063 options.log_facility, log_stderr);
1064 for (i = 0; i < options.num_log_verbose; i++)
1065 log_verbose_add(options.log_verbose[i]);
1066
1067 /* Reinitialize the log (because of the fork above). */
1068 log_init(__progname, options.log_level, options.log_facility, log_stderr);
1069
1070 /*
1071 * Chdir to the root directory so that the current disk can be
1072 * unmounted if desired.
1073 */
1074 if (chdir("/") == -1)
1075 error("chdir(\"/\"): %s", strerror(errno));
1076
1077 /* ignore SIGPIPE */
1078 ssh_signal(SIGPIPE, SIG_IGN);
1079
1080 /* Get a connection, either from inetd or rexec */
1081 if (inetd_flag) {
1082 /*
1083 * NB. must be different fd numbers for the !socket case,
1084 * as packet_connection_is_on_socket() depends on this.
1085 */
1086 sock_in = dup(STDIN_FILENO);
1087 sock_out = dup(STDOUT_FILENO);
1088 } else {
1089 /* rexec case; accept()ed socket in ancestor listener */
1090 sock_in = sock_out = dup(STDIN_FILENO);
1091 }
1092
1093 /*
1094 * We intentionally do not close the descriptors 0, 1, and 2
1095 * as our code for setting the descriptors won't work if
1096 * ttyfd happens to be one of those.
1097 */
1098 if (stdfd_devnull(1, 1, !log_stderr) == -1)
1099 error("stdfd_devnull failed");
1100 debug("network sockets: %d, %d", sock_in, sock_out);
1101
1102 /* This is the child processing a new connection. */
1103 setproctitle("%s", "[accepted]");
1104
1105 /* Executed child processes don't need these. */
1106 fcntl(sock_out, F_SETFD, FD_CLOEXEC);
1107 fcntl(sock_in, F_SETFD, FD_CLOEXEC);
1108
1109 /* We will not restart on SIGHUP since it no longer makes sense. */
1110 ssh_signal(SIGALRM, SIG_DFL);
1111 ssh_signal(SIGHUP, SIG_DFL);
1112 ssh_signal(SIGTERM, SIG_DFL);
1113 ssh_signal(SIGQUIT, SIG_DFL);
1114 ssh_signal(SIGCHLD, SIG_DFL);
1115
1116 /*
1117 * Register our connection. This turns encryption off because we do
1118 * not have a key.
1119 */
1120 if ((ssh = ssh_packet_set_connection(NULL, sock_in, sock_out)) == NULL)
1121 fatal("Unable to create connection");
1122 the_active_state = ssh;
1123 ssh_packet_set_server(ssh);
1124
1125 check_ip_options(ssh);
1126
1127 /* Prepare the channels layer */
1128 channel_init_channels(ssh);
1129 channel_set_af(ssh, options.address_family);
1130 server_process_channel_timeouts(ssh);
1131 server_process_permitopen(ssh);
1132
1133 /* Set SO_KEEPALIVE if requested. */
1134 if (options.tcp_keep_alive && ssh_packet_connection_is_on_socket(ssh) &&
1135 setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) == -1)
1136 error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1137
1138 if ((remote_port = ssh_remote_port(ssh)) < 0) {
1139 debug("ssh_remote_port failed");
1140 cleanup_exit(255);
1141 }
1142
1143 /*
1144 * The rest of the code depends on the fact that
1145 * ssh_remote_ipaddr() caches the remote ip, even if
1146 * the socket goes away.
1147 */
1148 remote_ip = ssh_remote_ipaddr(ssh);
1149
1150 rdomain = ssh_packet_rdomain_in(ssh);
1151
1152 /* Log the connection. */
1153 laddr = get_local_ipaddr(sock_in);
1154 verbose("Connection from %s port %d on %s port %d%s%s%s",
1155 remote_ip, remote_port, laddr, ssh_local_port(ssh),
1156 rdomain == NULL ? "" : " rdomain \"",
1157 rdomain == NULL ? "" : rdomain,
1158 rdomain == NULL ? "" : "\"");
1159 free(laddr);
1160
1161 /*
1162 * We don't want to listen forever unless the other side
1163 * successfully authenticates itself. So we set up an alarm which is
1164 * cleared after successful authentication. A limit of zero
1165 * indicates no limit. Note that we don't set the alarm in debugging
1166 * mode; it is just annoying to have the server exit just when you
1167 * are about to discover the bug.
1168 */
1169 ssh_signal(SIGALRM, grace_alarm_handler);
1170 if (!debug_flag)
1171 alarm(options.login_grace_time);
1172
1173 if ((r = kex_exchange_identification(ssh, -1,
1174 options.version_addendum)) != 0)
1175 sshpkt_fatal(ssh, r, "banner exchange");
1176
1177 ssh_packet_set_nonblocking(ssh);
1178
1179 /* allocate authentication context */
1180 authctxt = xcalloc(1, sizeof(*authctxt));
1181 ssh->authctxt = authctxt;
1182
1183 /* XXX global for cleanup, access from other modules */
1184 the_authctxt = authctxt;
1185
1186 /* Set default key authentication options */
1187 if ((auth_opts = sshauthopt_new_with_keys_defaults()) == NULL)
1188 fatal("allocation failed");
1189
1190 /* prepare buffer to collect messages to display to user after login */
1191 if ((loginmsg = sshbuf_new()) == NULL)
1192 fatal("sshbuf_new loginmsg failed");
1193 auth_debug_reset();
1194
1195 if (privsep_preauth(ssh) == 1)
1196 goto authenticated;
1197
1198 /* perform the key exchange */
1199 /* authenticate user and start session */
1200 do_ssh2_kex(ssh);
1201 do_authentication2(ssh);
1202
1203 /*
1204 * The unprivileged child now transfers the current keystate and exits.
1205 */
1206 mm_send_keystate(ssh, pmonitor);
1207 ssh_packet_clear_keys(ssh);
1208 exit(0);
1209
1210 authenticated:
1211 /*
1212 * Cancel the alarm we set to limit the time taken for
1213 * authentication.
1214 */
1215 alarm(0);
1216 ssh_signal(SIGALRM, SIG_DFL);
1217 authctxt->authenticated = 1;
1218 if (startup_pipe != -1) {
1219 /* signal listener that authentication completed successfully */
1220 (void)atomicio(vwrite, startup_pipe, "\001", 1);
1221 close(startup_pipe);
1222 startup_pipe = -1;
1223 }
1224
1225 if (options.routing_domain != NULL)
1226 set_process_rdomain(ssh, options.routing_domain);
1227
1228 /*
1229 * In privilege separation, we fork another child and prepare
1230 * file descriptor passing.
1231 */
1232 privsep_postauth(ssh, authctxt);
1233 /* the monitor process [priv] will not return */
1234
1235 ssh_packet_set_timeout(ssh, options.client_alive_interval,
1236 options.client_alive_count_max);
1237
1238 /* Try to send all our hostkeys to the client */
1239 notify_hostkeys(ssh);
1240
1241 /* Start session. */
1242 do_authenticated(ssh, authctxt);
1243
1244 /* The connection has been terminated. */
1245 ssh_packet_get_bytes(ssh, &ibytes, &obytes);
1246 verbose("Transferred: sent %llu, received %llu bytes",
1247 (unsigned long long)obytes, (unsigned long long)ibytes);
1248
1249 verbose("Closing connection to %.500s port %d", remote_ip, remote_port);
1250 ssh_packet_close(ssh);
1251
1252 mm_terminate();
1253
1254 exit(0);
1255 }
1256
1257 int
sshd_hostkey_sign(struct ssh * ssh,struct sshkey * privkey,struct sshkey * pubkey,u_char ** signature,size_t * slenp,const u_char * data,size_t dlen,const char * alg)1258 sshd_hostkey_sign(struct ssh *ssh, struct sshkey *privkey,
1259 struct sshkey *pubkey, u_char **signature, size_t *slenp,
1260 const u_char *data, size_t dlen, const char *alg)
1261 {
1262 if (privkey) {
1263 if (mm_sshkey_sign(ssh, privkey, signature, slenp,
1264 data, dlen, alg, options.sk_provider, NULL,
1265 ssh->compat) < 0)
1266 fatal_f("privkey sign failed");
1267 } else {
1268 if (mm_sshkey_sign(ssh, pubkey, signature, slenp,
1269 data, dlen, alg, options.sk_provider, NULL,
1270 ssh->compat) < 0)
1271 fatal_f("pubkey sign failed");
1272 }
1273 return 0;
1274 }
1275
1276 /* SSH2 key exchange */
1277 static void
do_ssh2_kex(struct ssh * ssh)1278 do_ssh2_kex(struct ssh *ssh)
1279 {
1280 char *hkalgs = NULL, *myproposal[PROPOSAL_MAX];
1281 const char *compression = NULL;
1282 struct kex *kex;
1283 int r;
1284
1285 if (options.rekey_limit || options.rekey_interval)
1286 ssh_packet_set_rekey_limits(ssh, options.rekey_limit,
1287 options.rekey_interval);
1288
1289 if (options.compression == COMP_NONE)
1290 compression = "none";
1291 hkalgs = list_hostkey_types();
1292
1293 kex_proposal_populate_entries(ssh, myproposal, options.kex_algorithms,
1294 options.ciphers, options.macs, compression, hkalgs);
1295
1296 free(hkalgs);
1297
1298 /* start key exchange */
1299 if ((r = kex_setup(ssh, myproposal)) != 0)
1300 fatal_r(r, "kex_setup");
1301 kex_set_server_sig_algs(ssh, options.pubkey_accepted_algos);
1302 kex = ssh->kex;
1303
1304 #ifdef WITH_OPENSSL
1305 kex->kex[KEX_DH_GRP1_SHA1] = kex_gen_server;
1306 kex->kex[KEX_DH_GRP14_SHA1] = kex_gen_server;
1307 kex->kex[KEX_DH_GRP14_SHA256] = kex_gen_server;
1308 kex->kex[KEX_DH_GRP16_SHA512] = kex_gen_server;
1309 kex->kex[KEX_DH_GRP18_SHA512] = kex_gen_server;
1310 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1311 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
1312 kex->kex[KEX_ECDH_SHA2] = kex_gen_server;
1313 #endif
1314 kex->kex[KEX_C25519_SHA256] = kex_gen_server;
1315 kex->kex[KEX_KEM_SNTRUP761X25519_SHA512] = kex_gen_server;
1316 kex->load_host_public_key=&get_hostkey_public_by_type;
1317 kex->load_host_private_key=&get_hostkey_private_by_type;
1318 kex->host_key_index=&get_hostkey_index;
1319 kex->sign = sshd_hostkey_sign;
1320
1321 ssh_dispatch_run_fatal(ssh, DISPATCH_BLOCK, &kex->done);
1322 kex_proposal_free_entries(myproposal);
1323
1324 #ifdef DEBUG_KEXDH
1325 /* send 1st encrypted/maced/compressed message */
1326 if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
1327 (r = sshpkt_put_cstring(ssh, "markus")) != 0 ||
1328 (r = sshpkt_send(ssh)) != 0 ||
1329 (r = ssh_packet_write_wait(ssh)) != 0)
1330 fatal_fr(r, "send test");
1331 #endif
1332 debug("KEX done");
1333 }
1334
1335 /* server specific fatal cleanup */
1336 void
cleanup_exit(int i)1337 cleanup_exit(int i)
1338 {
1339 extern int auth_attempted; /* monitor.c */
1340
1341 if (the_active_state != NULL && the_authctxt != NULL) {
1342 do_cleanup(the_active_state, the_authctxt);
1343 if (privsep_is_preauth &&
1344 pmonitor != NULL && pmonitor->m_pid > 1) {
1345 debug("Killing privsep child %d", pmonitor->m_pid);
1346 if (kill(pmonitor->m_pid, SIGKILL) != 0 &&
1347 errno != ESRCH) {
1348 error_f("kill(%d): %s", pmonitor->m_pid,
1349 strerror(errno));
1350 }
1351 }
1352 }
1353 /* Override default fatal exit value when auth was attempted */
1354 if (i == 255 && auth_attempted)
1355 _exit(EXIT_AUTH_ATTEMPTED);
1356 _exit(i);
1357 }
1358