2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * This program is the ssh daemon. It listens for connections from clients,
6 * and performs authentication, executes use commands or shell, and forwards
7 * information to/from the application to the user client over an encrypted
8 * connection. This can also handle forwarding of X11, TCP/IP, and
9 * authentication agent connections.
11 * As far as I am concerned, the code I have written for this software
12 * can be used freely for any purpose. Any derived versions of this
13 * software must be clearly marked as such, and if the derived work is
14 * incompatible with the protocol description in the RFC file, it must be
15 * called by a name other than "ssh" or "Secure Shell".
17 * SSH2 implementation:
18 * Privilege Separation:
20 * Copyright (c) 2000, 2001, 2002 Markus Friedl. All rights reserved.
21 * Copyright (c) 2002 Niels Provos. All rights reserved.
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
26 * 1. Redistributions of source code must retain the above copyright
27 * notice, this list of conditions and the following disclaimer.
28 * 2. Redistributions in binary form must reproduce the above copyright
29 * notice, this list of conditions and the following disclaimer in the
30 * documentation and/or other materials provided with the distribution.
32 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
33 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
34 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
35 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
36 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
37 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
38 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
39 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
40 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
41 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
45 RCSID("$OpenBSD: sshd.c,v 1.278 2003/09/23 20:17:11 markus Exp $");
47 #include <openssl/dh.h>
48 #include <openssl/bn.h>
49 #include <openssl/md5.h>
50 #include <openssl/rand.h>
51 #ifdef HAVE_SECUREWARE
52 #include <sys/security.h>
73 #include "myproposal.h"
75 #include "pathnames.h"
83 #include "monitor_mm.h"
85 #include "monitor_wrap.h"
86 #include "monitor_fdpass.h"
91 int allow_severity = LOG_INFO;
92 int deny_severity = LOG_WARNING;
99 #ifdef HAVE___PROGNAME
100 extern char *__progname;
105 /* Server configuration options. */
106 ServerOptions options;
108 /* Name of the server configuration file. */
109 char *config_file_name = _PATH_SERVER_CONFIG_FILE;
112 * Flag indicating whether IPv4 or IPv6. This can be set on the command line.
113 * Default value is AF_UNSPEC means both IPv4 and IPv6.
115 int IPv4or6 = AF_UNSPEC;
118 * Debug mode flag. This can be set on the command line. If debug
119 * mode is enabled, extra debugging output will be sent to the system
120 * log, the daemon will not go to background, and will exit after processing
121 * the first connection.
125 /* Flag indicating that the daemon should only test the configuration and keys. */
128 /* Flag indicating that the daemon is being started from inetd. */
131 /* Flag indicating that sshd should not detach and become a daemon. */
132 int no_daemon_flag = 0;
134 /* debug goes to stderr unless inetd_flag is set */
137 /* Saved arguments to main(). */
142 * The sockets that the server is listening; this is used in the SIGHUP
145 #define MAX_LISTEN_SOCKS 16
146 int listen_socks[MAX_LISTEN_SOCKS];
147 int num_listen_socks = 0;
150 * the client's version string, passed by sshd2 in compat mode. if != NULL,
151 * sshd will skip the version-number exchange
153 char *client_version_string = NULL;
154 char *server_version_string = NULL;
156 /* for rekeying XXX fixme */
160 * Any really sensitive data in the application is contained in this
161 * structure. The idea is that this structure could be locked into memory so
162 * that the pages do not get written into swap. However, there are some
163 * problems. The private key contains BIGNUMs, and we do not (in principle)
164 * have access to the internals of them, and locking just the structure is
165 * not very useful. Currently, memory locking is not implemented.
168 Key *server_key; /* ephemeral server key */
169 Key *ssh1_host_key; /* ssh1 host key */
170 Key **host_keys; /* all private host keys */
173 u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH];
177 * Flag indicating whether the RSA server key needs to be regenerated.
178 * Is set in the SIGALRM handler and cleared when the key is regenerated.
180 static volatile sig_atomic_t key_do_regen = 0;
182 /* This is set to true when a signal is received. */
183 static volatile sig_atomic_t received_sighup = 0;
184 static volatile sig_atomic_t received_sigterm = 0;
186 /* session identifier, used by RSA-auth */
187 u_char session_id[16];
190 u_char *session_id2 = NULL;
191 u_int session_id2_len = 0;
193 /* record remote hostname or ip */
194 u_int utmp_len = MAXHOSTNAMELEN;
196 /* options.max_startup sized array of fd ints */
197 int *startup_pipes = NULL;
198 int startup_pipe; /* in child */
200 /* variables used for privilege separation */
202 struct monitor *pmonitor;
204 /* message to be displayed after login */
207 /* global authentication context */
208 Authctxt *the_authctxt = NULL;
210 /* Prototypes for various functions defined later in this file. */
211 void destroy_sensitive_data(void);
212 void demote_sensitive_data(void);
214 static void do_ssh1_kex(void);
215 static void do_ssh2_kex(void);
218 * Close all listening sockets
221 close_listen_socks(void)
225 for (i = 0; i < num_listen_socks; i++)
226 close(listen_socks[i]);
227 num_listen_socks = -1;
231 close_startup_pipes(void)
236 for (i = 0; i < options.max_startups; i++)
237 if (startup_pipes[i] != -1)
238 close(startup_pipes[i]);
242 * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP;
243 * the effect is to reread the configuration file (and to regenerate
247 sighup_handler(int sig)
249 int save_errno = errno;
252 signal(SIGHUP, sighup_handler);
257 * Called from the main program after receiving SIGHUP.
258 * Restarts the server.
263 logit("Received SIGHUP; restarting.");
264 close_listen_socks();
265 close_startup_pipes();
266 execv(saved_argv[0], saved_argv);
267 logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0],
273 * Generic signal handler for terminating signals in the master daemon.
276 sigterm_handler(int sig)
278 received_sigterm = sig;
282 * SIGCHLD handler. This is called whenever a child dies. This will then
283 * reap any zombies left by exited children.
286 main_sigchld_handler(int sig)
288 int save_errno = errno;
292 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
293 (pid < 0 && errno == EINTR))
296 signal(SIGCHLD, main_sigchld_handler);
301 * Signal handler for the alarm after the login grace period has expired.
304 grace_alarm_handler(int sig)
306 /* XXX no idea how fix this signal handler */
308 /* Log error and exit. */
309 fatal("Timeout before authentication for %s", get_remote_ipaddr());
313 * Signal handler for the key regeneration alarm. Note that this
314 * alarm only occurs in the daemon waiting for connections, and it does not
315 * do anything with the private key or random state before forking.
316 * Thus there should be no concurrency control/asynchronous execution
320 generate_ephemeral_server_key(void)
325 verbose("Generating %s%d bit RSA key.",
326 sensitive_data.server_key ? "new " : "", options.server_key_bits);
327 if (sensitive_data.server_key != NULL)
328 key_free(sensitive_data.server_key);
329 sensitive_data.server_key = key_generate(KEY_RSA1,
330 options.server_key_bits);
331 verbose("RSA key generation complete.");
333 for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) {
336 sensitive_data.ssh1_cookie[i] = rnd & 0xff;
343 key_regeneration_alarm(int sig)
345 int save_errno = errno;
347 signal(SIGALRM, SIG_DFL);
353 sshd_exchange_identification(int sock_in, int sock_out)
356 int remote_major, remote_minor;
359 char buf[256]; /* Must not be larger than remote_version. */
360 char remote_version[256]; /* Must be at least as big as buf. */
362 if ((options.protocol & SSH_PROTO_1) &&
363 (options.protocol & SSH_PROTO_2)) {
364 major = PROTOCOL_MAJOR_1;
366 } else if (options.protocol & SSH_PROTO_2) {
367 major = PROTOCOL_MAJOR_2;
368 minor = PROTOCOL_MINOR_2;
370 major = PROTOCOL_MAJOR_1;
371 minor = PROTOCOL_MINOR_1;
373 snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", major, minor, SSH_VERSION);
374 server_version_string = xstrdup(buf);
376 /* Send our protocol version identification. */
377 if (atomicio(vwrite, sock_out, server_version_string,
378 strlen(server_version_string))
379 != strlen(server_version_string)) {
380 logit("Could not write ident string to %s", get_remote_ipaddr());
384 /* Read other sides version identification. */
385 memset(buf, 0, sizeof(buf));
386 for (i = 0; i < sizeof(buf) - 1; i++) {
387 if (atomicio(read, sock_in, &buf[i], 1) != 1) {
388 logit("Did not receive identification string from %s",
389 get_remote_ipaddr());
392 if (buf[i] == '\r') {
394 /* Kludge for F-Secure Macintosh < 1.0.2 */
396 strncmp(buf, "SSH-1.5-W1.0", 12) == 0)
400 if (buf[i] == '\n') {
405 buf[sizeof(buf) - 1] = 0;
406 client_version_string = xstrdup(buf);
409 * Check that the versions match. In future this might accept
410 * several versions and set appropriate flags to handle them.
412 if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n",
413 &remote_major, &remote_minor, remote_version) != 3) {
414 s = "Protocol mismatch.\n";
415 (void) atomicio(vwrite, sock_out, s, strlen(s));
418 logit("Bad protocol version identification '%.100s' from %s",
419 client_version_string, get_remote_ipaddr());
422 debug("Client protocol version %d.%d; client software version %.100s",
423 remote_major, remote_minor, remote_version);
425 compat_datafellows(remote_version);
427 if (datafellows & SSH_BUG_PROBE) {
428 logit("probed from %s with %s. Don't panic.",
429 get_remote_ipaddr(), client_version_string);
433 if (datafellows & SSH_BUG_SCANNER) {
434 logit("scanned from %s with %s. Don't panic.",
435 get_remote_ipaddr(), client_version_string);
440 switch (remote_major) {
442 if (remote_minor == 99) {
443 if (options.protocol & SSH_PROTO_2)
449 if (!(options.protocol & SSH_PROTO_1)) {
453 if (remote_minor < 3) {
454 packet_disconnect("Your ssh version is too old and "
455 "is no longer supported. Please install a newer version.");
456 } else if (remote_minor == 3) {
457 /* note that this disables agent-forwarding */
462 if (options.protocol & SSH_PROTO_2) {
471 chop(server_version_string);
472 debug("Local version string %.200s", server_version_string);
475 s = "Protocol major versions differ.\n";
476 (void) atomicio(vwrite, sock_out, s, strlen(s));
479 logit("Protocol major versions differ for %s: %.200s vs. %.200s",
481 server_version_string, client_version_string);
486 /* Destroy the host and server keys. They will no longer be needed. */
488 destroy_sensitive_data(void)
492 if (sensitive_data.server_key) {
493 key_free(sensitive_data.server_key);
494 sensitive_data.server_key = NULL;
496 for (i = 0; i < options.num_host_key_files; i++) {
497 if (sensitive_data.host_keys[i]) {
498 key_free(sensitive_data.host_keys[i]);
499 sensitive_data.host_keys[i] = NULL;
502 sensitive_data.ssh1_host_key = NULL;
503 memset(sensitive_data.ssh1_cookie, 0, SSH_SESSION_KEY_LENGTH);
506 /* Demote private to public keys for network child */
508 demote_sensitive_data(void)
513 if (sensitive_data.server_key) {
514 tmp = key_demote(sensitive_data.server_key);
515 key_free(sensitive_data.server_key);
516 sensitive_data.server_key = tmp;
519 for (i = 0; i < options.num_host_key_files; i++) {
520 if (sensitive_data.host_keys[i]) {
521 tmp = key_demote(sensitive_data.host_keys[i]);
522 key_free(sensitive_data.host_keys[i]);
523 sensitive_data.host_keys[i] = tmp;
524 if (tmp->type == KEY_RSA1)
525 sensitive_data.ssh1_host_key = tmp;
529 /* We do not clear ssh1_host key and cookie. XXX - Okay Niels? */
533 privsep_preauth_child(void)
540 /* Enable challenge-response authentication for privilege separation */
541 privsep_challenge_enable();
543 for (i = 0; i < 256; i++)
544 rnd[i] = arc4random();
545 RAND_seed(rnd, sizeof(rnd));
547 /* Demote the private keys to public keys. */
548 demote_sensitive_data();
550 if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
551 fatal("Privilege separation user %s does not exist",
553 memset(pw->pw_passwd, 0, strlen(pw->pw_passwd));
556 /* Change our root directory */
557 if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1)
558 fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR,
560 if (chdir("/") == -1)
561 fatal("chdir(\"/\"): %s", strerror(errno));
563 /* Drop our privileges */
564 debug3("privsep user:group %u:%u", (u_int)pw->pw_uid,
567 /* XXX not ready, to heavy after chroot */
568 do_setusercontext(pw);
570 gidset[0] = pw->pw_gid;
571 if (setgroups(1, gidset) < 0)
572 fatal("setgroups: %.100s", strerror(errno));
573 permanently_set_uid(pw);
578 privsep_preauth(Authctxt *authctxt)
583 /* Set up unprivileged child process to deal with network data */
584 pmonitor = monitor_init();
585 /* Store a pointer to the kex for later rekeying */
586 pmonitor->m_pkex = &xxx_kex;
590 fatal("fork of unprivileged child failed");
591 } else if (pid != 0) {
592 debug2("Network child is on pid %ld", (long)pid);
594 close(pmonitor->m_recvfd);
595 monitor_child_preauth(authctxt, pmonitor);
596 close(pmonitor->m_sendfd);
599 monitor_sync(pmonitor);
601 /* Wait for the child's exit status */
602 while (waitpid(pid, &status, 0) < 0)
609 close(pmonitor->m_sendfd);
611 /* Demote the child */
612 if (getuid() == 0 || geteuid() == 0)
613 privsep_preauth_child();
614 setproctitle("%s", "[net]");
620 privsep_postauth(Authctxt *authctxt)
622 #ifdef DISABLE_FD_PASSING
625 if (authctxt->pw->pw_uid == 0 || options.use_login) {
627 /* File descriptor passing is broken or root login */
628 monitor_apply_keystate(pmonitor);
633 /* Authentication complete */
635 if (startup_pipe != -1) {
640 /* New socket pair */
641 monitor_reinit(pmonitor);
643 pmonitor->m_pid = fork();
644 if (pmonitor->m_pid == -1)
645 fatal("fork of unprivileged child failed");
646 else if (pmonitor->m_pid != 0) {
647 debug2("User child is on pid %ld", (long)pmonitor->m_pid);
648 close(pmonitor->m_recvfd);
649 monitor_child_postauth(pmonitor);
655 close(pmonitor->m_sendfd);
657 /* Demote the private keys to public keys. */
658 demote_sensitive_data();
660 /* Drop privileges */
661 do_setusercontext(authctxt->pw);
663 /* It is safe now to apply the key state */
664 monitor_apply_keystate(pmonitor);
668 list_hostkey_types(void)
675 for (i = 0; i < options.num_host_key_files; i++) {
676 Key *key = sensitive_data.host_keys[i];
682 if (buffer_len(&b) > 0)
683 buffer_append(&b, ",", 1);
684 p = key_ssh_name(key);
685 buffer_append(&b, p, strlen(p));
689 buffer_append(&b, "\0", 1);
690 p = xstrdup(buffer_ptr(&b));
692 debug("list_hostkey_types: %s", p);
697 get_hostkey_by_type(int type)
701 for (i = 0; i < options.num_host_key_files; i++) {
702 Key *key = sensitive_data.host_keys[i];
703 if (key != NULL && key->type == type)
710 get_hostkey_by_index(int ind)
712 if (ind < 0 || ind >= options.num_host_key_files)
714 return (sensitive_data.host_keys[ind]);
718 get_hostkey_index(Key *key)
722 for (i = 0; i < options.num_host_key_files; i++) {
723 if (key == sensitive_data.host_keys[i])
730 * returns 1 if connection should be dropped, 0 otherwise.
731 * dropping starts at connection #max_startups_begin with a probability
732 * of (max_startups_rate/100). the probability increases linearly until
733 * all connections are dropped for startups > max_startups
736 drop_connection(int startups)
740 if (startups < options.max_startups_begin)
742 if (startups >= options.max_startups)
744 if (options.max_startups_rate == 100)
747 p = 100 - options.max_startups_rate;
748 p *= startups - options.max_startups_begin;
749 p /= (double) (options.max_startups - options.max_startups_begin);
750 p += options.max_startups_rate;
752 r = arc4random() / (double) UINT_MAX;
754 debug("drop_connection: p %g, r %g", p, r);
755 return (r < p) ? 1 : 0;
761 fprintf(stderr, "sshd version %s\n", SSH_VERSION);
762 fprintf(stderr, "Usage: %s [options]\n", __progname);
763 fprintf(stderr, "Options:\n");
764 fprintf(stderr, " -f file Configuration file (default %s)\n", _PATH_SERVER_CONFIG_FILE);
765 fprintf(stderr, " -d Debugging mode (multiple -d means more debugging)\n");
766 fprintf(stderr, " -i Started from inetd\n");
767 fprintf(stderr, " -D Do not fork into daemon mode\n");
768 fprintf(stderr, " -t Only test configuration file and keys\n");
769 fprintf(stderr, " -q Quiet (no logging)\n");
770 fprintf(stderr, " -p port Listen on the specified port (default: 22)\n");
771 fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n");
772 fprintf(stderr, " -g seconds Grace period for authentication (default: 600)\n");
773 fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n");
774 fprintf(stderr, " -h file File from which to read host key (default: %s)\n",
775 _PATH_HOST_KEY_FILE);
776 fprintf(stderr, " -u len Maximum hostname length for utmp recording\n");
777 fprintf(stderr, " -4 Use IPv4 only\n");
778 fprintf(stderr, " -6 Use IPv6 only\n");
779 fprintf(stderr, " -o option Process the option as if it was read from a configuration file.\n");
784 * Main program for the daemon.
787 main(int ac, char **av)
791 int opt, sock_in = 0, sock_out = 0, newsock, j, i, fdsetsz, on = 1;
795 struct sockaddr_storage from;
796 const char *remote_ip;
800 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
801 int listen_sock, maxfd;
806 int ret, key_used = 0;
808 #ifdef HAVE_SECUREWARE
809 (void)set_auth_parameters(ac, av);
811 __progname = ssh_get_progname(av[0]);
814 /* Save argv. Duplicate so setproctitle emulation doesn't clobber it */
816 saved_argv = xmalloc(sizeof(*saved_argv) * (ac + 1));
817 for (i = 0; i < ac; i++)
818 saved_argv[i] = xstrdup(av[i]);
819 saved_argv[i] = NULL;
821 #ifndef HAVE_SETPROCTITLE
822 /* Prepare for later setproctitle emulation */
823 compat_init_setproctitle(ac, av);
827 /* Initialize configuration options to their default values. */
828 initialize_server_options(&options);
830 /* Parse command-line arguments. */
831 while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:dDeiqtQ46")) != -1) {
840 config_file_name = optarg;
843 if (debug_flag == 0) {
845 options.log_level = SYSLOG_LEVEL_DEBUG1;
846 } else if (options.log_level < SYSLOG_LEVEL_DEBUG3)
862 options.log_level = SYSLOG_LEVEL_QUIET;
865 options.server_key_bits = atoi(optarg);
868 options.ports_from_cmdline = 1;
869 if (options.num_ports >= MAX_PORTS) {
870 fprintf(stderr, "too many ports.\n");
873 options.ports[options.num_ports++] = a2port(optarg);
874 if (options.ports[options.num_ports-1] == 0) {
875 fprintf(stderr, "Bad port number.\n");
880 if ((options.login_grace_time = convtime(optarg)) == -1) {
881 fprintf(stderr, "Invalid login grace time.\n");
886 if ((options.key_regeneration_time = convtime(optarg)) == -1) {
887 fprintf(stderr, "Invalid key regeneration interval.\n");
892 if (options.num_host_key_files >= MAX_HOSTKEYS) {
893 fprintf(stderr, "too many host keys.\n");
896 options.host_key_files[options.num_host_key_files++] = optarg;
902 utmp_len = atoi(optarg);
903 if (utmp_len > MAXHOSTNAMELEN) {
904 fprintf(stderr, "Invalid utmp length.\n");
909 if (process_server_config_line(&options, optarg,
910 "command-line", 0) != 0)
919 SSLeay_add_all_algorithms();
920 channel_set_af(IPv4or6);
923 * Force logging to stderr until we have loaded the private host
924 * key (unless started from inetd)
927 options.log_level == SYSLOG_LEVEL_NOT_SET ?
928 SYSLOG_LEVEL_INFO : options.log_level,
929 options.log_facility == SYSLOG_FACILITY_NOT_SET ?
930 SYSLOG_FACILITY_AUTH : options.log_facility,
931 log_stderr || !inetd_flag);
934 /* Cray can define user privs drop all prives now!
935 * Not needed on PRIV_SU systems!
942 /* Read server configuration options from the configuration file. */
943 read_server_config(&options, config_file_name);
945 /* Fill in default values for those options not explicitly set. */
946 fill_default_server_options(&options);
948 /* Check that there are no remaining arguments. */
950 fprintf(stderr, "Extra argument %s.\n", av[optind]);
954 debug("sshd version %.100s", SSH_VERSION);
956 /* load private host keys */
957 sensitive_data.host_keys = xmalloc(options.num_host_key_files *
959 for (i = 0; i < options.num_host_key_files; i++)
960 sensitive_data.host_keys[i] = NULL;
961 sensitive_data.server_key = NULL;
962 sensitive_data.ssh1_host_key = NULL;
963 sensitive_data.have_ssh1_key = 0;
964 sensitive_data.have_ssh2_key = 0;
966 for (i = 0; i < options.num_host_key_files; i++) {
967 key = key_load_private(options.host_key_files[i], "", NULL);
968 sensitive_data.host_keys[i] = key;
970 error("Could not load host key: %s",
971 options.host_key_files[i]);
972 sensitive_data.host_keys[i] = NULL;
977 sensitive_data.ssh1_host_key = key;
978 sensitive_data.have_ssh1_key = 1;
982 sensitive_data.have_ssh2_key = 1;
985 debug("private host key: #%d type %d %s", i, key->type,
988 if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) {
989 logit("Disabling protocol version 1. Could not load host key");
990 options.protocol &= ~SSH_PROTO_1;
992 if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) {
993 logit("Disabling protocol version 2. Could not load host key");
994 options.protocol &= ~SSH_PROTO_2;
996 if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
997 logit("sshd: no hostkeys available -- exiting.");
1001 /* Check certain values for sanity. */
1002 if (options.protocol & SSH_PROTO_1) {
1003 if (options.server_key_bits < 512 ||
1004 options.server_key_bits > 32768) {
1005 fprintf(stderr, "Bad server key size.\n");
1009 * Check that server and host key lengths differ sufficiently. This
1010 * is necessary to make double encryption work with rsaref. Oh, I
1011 * hate software patents. I dont know if this can go? Niels
1013 if (options.server_key_bits >
1014 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) -
1015 SSH_KEY_BITS_RESERVED && options.server_key_bits <
1016 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
1017 SSH_KEY_BITS_RESERVED) {
1018 options.server_key_bits =
1019 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
1020 SSH_KEY_BITS_RESERVED;
1021 debug("Forcing server key to %d bits to make it differ from host key.",
1022 options.server_key_bits);
1030 if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
1031 fatal("Privilege separation user %s does not exist",
1033 if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) ||
1034 (S_ISDIR(st.st_mode) == 0))
1035 fatal("Missing privilege separation directory: %s",
1036 _PATH_PRIVSEP_CHROOT_DIR);
1039 if (check_ntsec(_PATH_PRIVSEP_CHROOT_DIR) &&
1040 (st.st_uid != getuid () ||
1041 (st.st_mode & (S_IWGRP|S_IWOTH)) != 0))
1043 if (st.st_uid != 0 || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)
1045 fatal("%s must be owned by root and not group or "
1046 "world-writable.", _PATH_PRIVSEP_CHROOT_DIR);
1049 /* Configuration looks good, so exit if in test mode. */
1054 * Clear out any supplemental groups we may have inherited. This
1055 * prevents inadvertent creation of files with bad modes (in the
1056 * portable version at least, it's certainly possible for PAM
1057 * to create a file, and we can't control the code in every
1058 * module which might be used).
1060 if (setgroups(0, NULL) < 0)
1061 debug("setgroups() failed: %.200s", strerror(errno));
1063 /* Initialize the log (it is reinitialized below in case we forked). */
1064 if (debug_flag && !inetd_flag)
1066 log_init(__progname, options.log_level, options.log_facility, log_stderr);
1069 * If not in debugging mode, and not started from inetd, disconnect
1070 * from the controlling terminal, and fork. The original process
1073 if (!(debug_flag || inetd_flag || no_daemon_flag)) {
1076 #endif /* TIOCNOTTY */
1077 if (daemon(0, 0) < 0)
1078 fatal("daemon() failed: %.200s", strerror(errno));
1080 /* Disconnect from the controlling tty. */
1082 fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
1084 (void) ioctl(fd, TIOCNOTTY, NULL);
1087 #endif /* TIOCNOTTY */
1089 /* Reinitialize the log (because of the fork above). */
1090 log_init(__progname, options.log_level, options.log_facility, log_stderr);
1092 /* Initialize the random number generator. */
1095 /* Chdir to the root directory so that the current disk can be
1096 unmounted if desired. */
1099 /* ignore SIGPIPE */
1100 signal(SIGPIPE, SIG_IGN);
1102 /* Start listening for a socket, unless started from inetd. */
1105 s1 = dup(0); /* Make sure descriptors 0, 1, and 2 are in use. */
1111 * We intentionally do not close the descriptors 0, 1, and 2
1112 * as our code for setting the descriptors won\'t work if
1113 * ttyfd happens to be one of those.
1115 debug("inetd sockets after dupping: %d, %d", sock_in, sock_out);
1116 if (options.protocol & SSH_PROTO_1)
1117 generate_ephemeral_server_key();
1119 for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
1120 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1122 if (num_listen_socks >= MAX_LISTEN_SOCKS)
1123 fatal("Too many listen sockets. "
1124 "Enlarge MAX_LISTEN_SOCKS");
1125 if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
1126 ntop, sizeof(ntop), strport, sizeof(strport),
1127 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1128 error("getnameinfo failed");
1131 /* Create socket for listening. */
1132 listen_sock = socket(ai->ai_family, ai->ai_socktype,
1134 if (listen_sock < 0) {
1135 /* kernel may not support ipv6 */
1136 verbose("socket: %.100s", strerror(errno));
1139 if (fcntl(listen_sock, F_SETFL, O_NONBLOCK) < 0) {
1140 error("listen_sock O_NONBLOCK: %s", strerror(errno));
1145 * Set socket options.
1146 * Allow local port reuse in TIME_WAIT.
1148 if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
1149 &on, sizeof(on)) == -1)
1150 error("setsockopt SO_REUSEADDR: %s", strerror(errno));
1152 debug("Bind to port %s on %s.", strport, ntop);
1154 /* Bind the socket to the desired port. */
1155 if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1157 error("Bind to port %s on %s failed: %.200s.",
1158 strport, ntop, strerror(errno));
1162 listen_socks[num_listen_socks] = listen_sock;
1165 /* Start listening on the port. */
1166 logit("Server listening on %s port %s.", ntop, strport);
1167 if (listen(listen_sock, 5) < 0)
1168 fatal("listen: %.100s", strerror(errno));
1171 freeaddrinfo(options.listen_addrs);
1173 if (!num_listen_socks)
1174 fatal("Cannot bind any address.");
1176 if (options.protocol & SSH_PROTO_1)
1177 generate_ephemeral_server_key();
1180 * Arrange to restart on SIGHUP. The handler needs
1183 signal(SIGHUP, sighup_handler);
1185 signal(SIGTERM, sigterm_handler);
1186 signal(SIGQUIT, sigterm_handler);
1188 /* Arrange SIGCHLD to be caught. */
1189 signal(SIGCHLD, main_sigchld_handler);
1191 /* Write out the pid file after the sigterm handler is setup */
1194 * Record our pid in /var/run/sshd.pid to make it
1195 * easier to kill the correct sshd. We don't want to
1196 * do this before the bind above because the bind will
1197 * fail if there already is a daemon, and this will
1198 * overwrite any old pid in the file.
1200 f = fopen(options.pid_file, "wb");
1202 error("Couldn't create pid file \"%s\": %s",
1203 options.pid_file, strerror(errno));
1205 fprintf(f, "%ld\n", (long) getpid());
1210 /* setup fd set for listen */
1213 for (i = 0; i < num_listen_socks; i++)
1214 if (listen_socks[i] > maxfd)
1215 maxfd = listen_socks[i];
1216 /* pipes connected to unauthenticated childs */
1217 startup_pipes = xmalloc(options.max_startups * sizeof(int));
1218 for (i = 0; i < options.max_startups; i++)
1219 startup_pipes[i] = -1;
1222 * Stay listening for connections until the system crashes or
1223 * the daemon is killed with a signal.
1226 if (received_sighup)
1230 fdsetsz = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask);
1231 fdset = (fd_set *)xmalloc(fdsetsz);
1232 memset(fdset, 0, fdsetsz);
1234 for (i = 0; i < num_listen_socks; i++)
1235 FD_SET(listen_socks[i], fdset);
1236 for (i = 0; i < options.max_startups; i++)
1237 if (startup_pipes[i] != -1)
1238 FD_SET(startup_pipes[i], fdset);
1240 /* Wait in select until there is a connection. */
1241 ret = select(maxfd+1, fdset, NULL, NULL, NULL);
1242 if (ret < 0 && errno != EINTR)
1243 error("select: %.100s", strerror(errno));
1244 if (received_sigterm) {
1245 logit("Received signal %d; terminating.",
1246 (int) received_sigterm);
1247 close_listen_socks();
1248 unlink(options.pid_file);
1251 if (key_used && key_do_regen) {
1252 generate_ephemeral_server_key();
1259 for (i = 0; i < options.max_startups; i++)
1260 if (startup_pipes[i] != -1 &&
1261 FD_ISSET(startup_pipes[i], fdset)) {
1263 * the read end of the pipe is ready
1264 * if the child has closed the pipe
1265 * after successful authentication
1266 * or if the child has died
1268 close(startup_pipes[i]);
1269 startup_pipes[i] = -1;
1272 for (i = 0; i < num_listen_socks; i++) {
1273 if (!FD_ISSET(listen_socks[i], fdset))
1275 fromlen = sizeof(from);
1276 newsock = accept(listen_socks[i], (struct sockaddr *)&from,
1279 if (errno != EINTR && errno != EWOULDBLOCK)
1280 error("accept: %.100s", strerror(errno));
1283 if (fcntl(newsock, F_SETFL, 0) < 0) {
1284 error("newsock del O_NONBLOCK: %s", strerror(errno));
1288 if (drop_connection(startups) == 1) {
1289 debug("drop connection #%d", startups);
1293 if (pipe(startup_p) == -1) {
1298 for (j = 0; j < options.max_startups; j++)
1299 if (startup_pipes[j] == -1) {
1300 startup_pipes[j] = startup_p[0];
1301 if (maxfd < startup_p[0])
1302 maxfd = startup_p[0];
1308 * Got connection. Fork a child to handle it, unless
1309 * we are in debugging mode.
1313 * In debugging mode. Close the listening
1314 * socket, and start processing the
1315 * connection without forking.
1317 debug("Server will not fork when running in debugging mode.");
1318 close_listen_socks();
1326 * Normal production daemon. Fork, and have
1327 * the child process the connection. The
1328 * parent continues listening.
1330 if ((pid = fork()) == 0) {
1332 * Child. Close the listening and max_startup
1333 * sockets. Start using the accepted socket.
1334 * Reinitialize logging (since our pid has
1335 * changed). We break out of the loop to handle
1338 startup_pipe = startup_p[1];
1339 close_startup_pipes();
1340 close_listen_socks();
1343 log_init(__progname, options.log_level, options.log_facility, log_stderr);
1348 /* Parent. Stay in the loop. */
1350 error("fork: %.100s", strerror(errno));
1352 debug("Forked child %ld.", (long)pid);
1354 close(startup_p[1]);
1356 /* Mark that the key has been used (it was "given" to the child). */
1357 if ((options.protocol & SSH_PROTO_1) &&
1359 /* Schedule server key regeneration alarm. */
1360 signal(SIGALRM, key_regeneration_alarm);
1361 alarm(options.key_regeneration_time);
1367 /* Close the new socket (the child is now taking care of it). */
1370 /* child process check (or debug mode) */
1371 if (num_listen_socks < 0)
1376 /* This is the child processing a new connection. */
1379 * Create a new session and process group since the 4.4BSD
1380 * setlogin() affects the entire process group. We don't
1381 * want the child to be able to affect the parent.
1383 #if !defined(SSHD_ACQUIRES_CTTY)
1385 * If setsid is called, on some platforms sshd will later acquire a
1386 * controlling terminal which will result in "could not set
1387 * controlling tty" errors.
1389 if (!debug_flag && !inetd_flag && setsid() < 0)
1390 error("setsid: %.100s", strerror(errno));
1394 * Disable the key regeneration alarm. We will not regenerate the
1395 * key since we are no longer in a position to give it to anyone. We
1396 * will not restart on SIGHUP since it no longer makes sense.
1399 signal(SIGALRM, SIG_DFL);
1400 signal(SIGHUP, SIG_DFL);
1401 signal(SIGTERM, SIG_DFL);
1402 signal(SIGQUIT, SIG_DFL);
1403 signal(SIGCHLD, SIG_DFL);
1404 signal(SIGINT, SIG_DFL);
1406 /* Set keepalives if requested. */
1407 if (options.keepalives &&
1408 setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on,
1410 error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1413 * Register our connection. This turns encryption off because we do
1416 packet_set_connection(sock_in, sock_out);
1418 remote_port = get_remote_port();
1419 remote_ip = get_remote_ipaddr();
1422 /* Check whether logins are denied from this host. */
1424 struct request_info req;
1426 request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0);
1429 if (!hosts_access(&req)) {
1430 debug("Connection refused by tcp wrapper");
1433 fatal("libwrap refuse returns");
1436 #endif /* LIBWRAP */
1438 /* Log the connection. */
1439 verbose("Connection from %.500s port %d", remote_ip, remote_port);
1442 * We don\'t want to listen forever unless the other side
1443 * successfully authenticates itself. So we set up an alarm which is
1444 * cleared after successful authentication. A limit of zero
1445 * indicates no limit. Note that we don\'t set the alarm in debugging
1446 * mode; it is just annoying to have the server exit just when you
1447 * are about to discover the bug.
1449 signal(SIGALRM, grace_alarm_handler);
1451 alarm(options.login_grace_time);
1453 sshd_exchange_identification(sock_in, sock_out);
1455 packet_set_nonblocking();
1457 /* prepare buffers to collect authentication messages */
1458 buffer_init(&loginmsg);
1460 /* allocate authentication context */
1461 authctxt = xmalloc(sizeof(*authctxt));
1462 memset(authctxt, 0, sizeof(*authctxt));
1464 /* XXX global for cleanup, access from other modules */
1465 the_authctxt = authctxt;
1468 if (privsep_preauth(authctxt) == 1)
1471 /* perform the key exchange */
1472 /* authenticate user and start session */
1475 do_authentication2(authctxt);
1478 do_authentication(authctxt);
1481 * If we use privilege separation, the unprivileged child transfers
1482 * the current keystate and exits
1485 mm_send_keystate(pmonitor);
1491 * In privilege separation, we fork another child and prepare
1492 * file descriptor passing.
1495 privsep_postauth(authctxt);
1496 /* the monitor process [priv] will not return */
1498 destroy_sensitive_data();
1501 /* Start session. */
1502 do_authenticated(authctxt);
1504 /* The connection has been terminated. */
1505 verbose("Closing connection to %.100s", remote_ip);
1508 if (options.use_pam)
1510 #endif /* USE_PAM */
1521 * Decrypt session_key_int using our private server key and private host key
1522 * (key with larger modulus first).
1525 ssh1_session_key(BIGNUM *session_key_int)
1529 if (BN_cmp(sensitive_data.server_key->rsa->n, sensitive_data.ssh1_host_key->rsa->n) > 0) {
1530 /* Server key has bigger modulus. */
1531 if (BN_num_bits(sensitive_data.server_key->rsa->n) <
1532 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
1533 fatal("do_connection: %s: server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
1534 get_remote_ipaddr(),
1535 BN_num_bits(sensitive_data.server_key->rsa->n),
1536 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
1537 SSH_KEY_BITS_RESERVED);
1539 if (rsa_private_decrypt(session_key_int, session_key_int,
1540 sensitive_data.server_key->rsa) <= 0)
1542 if (rsa_private_decrypt(session_key_int, session_key_int,
1543 sensitive_data.ssh1_host_key->rsa) <= 0)
1546 /* Host key has bigger modulus (or they are equal). */
1547 if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) <
1548 BN_num_bits(sensitive_data.server_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
1549 fatal("do_connection: %s: host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d",
1550 get_remote_ipaddr(),
1551 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
1552 BN_num_bits(sensitive_data.server_key->rsa->n),
1553 SSH_KEY_BITS_RESERVED);
1555 if (rsa_private_decrypt(session_key_int, session_key_int,
1556 sensitive_data.ssh1_host_key->rsa) < 0)
1558 if (rsa_private_decrypt(session_key_int, session_key_int,
1559 sensitive_data.server_key->rsa) < 0)
1572 BIGNUM *session_key_int;
1573 u_char session_key[SSH_SESSION_KEY_LENGTH];
1575 u_int cipher_type, auth_mask, protocol_flags;
1579 * Generate check bytes that the client must send back in the user
1580 * packet in order for it to be accepted; this is used to defy ip
1581 * spoofing attacks. Note that this only works against somebody
1582 * doing IP spoofing from a remote machine; any machine on the local
1583 * network can still see outgoing packets and catch the random
1584 * cookie. This only affects rhosts authentication, and this is one
1585 * of the reasons why it is inherently insecure.
1587 for (i = 0; i < 8; i++) {
1590 cookie[i] = rnd & 0xff;
1595 * Send our public key. We include in the packet 64 bits of random
1596 * data that must be matched in the reply in order to prevent IP
1599 packet_start(SSH_SMSG_PUBLIC_KEY);
1600 for (i = 0; i < 8; i++)
1601 packet_put_char(cookie[i]);
1603 /* Store our public server RSA key. */
1604 packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n));
1605 packet_put_bignum(sensitive_data.server_key->rsa->e);
1606 packet_put_bignum(sensitive_data.server_key->rsa->n);
1608 /* Store our public host RSA key. */
1609 packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
1610 packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e);
1611 packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n);
1613 /* Put protocol flags. */
1614 packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN);
1616 /* Declare which ciphers we support. */
1617 packet_put_int(cipher_mask_ssh1(0));
1619 /* Declare supported authentication types. */
1621 if (options.rhosts_rsa_authentication)
1622 auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA;
1623 if (options.rsa_authentication)
1624 auth_mask |= 1 << SSH_AUTH_RSA;
1625 if (options.challenge_response_authentication == 1)
1626 auth_mask |= 1 << SSH_AUTH_TIS;
1627 if (options.password_authentication)
1628 auth_mask |= 1 << SSH_AUTH_PASSWORD;
1629 packet_put_int(auth_mask);
1631 /* Send the packet and wait for it to be sent. */
1633 packet_write_wait();
1635 debug("Sent %d bit server key and %d bit host key.",
1636 BN_num_bits(sensitive_data.server_key->rsa->n),
1637 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
1639 /* Read clients reply (cipher type and session key). */
1640 packet_read_expect(SSH_CMSG_SESSION_KEY);
1642 /* Get cipher type and check whether we accept this. */
1643 cipher_type = packet_get_char();
1645 if (!(cipher_mask_ssh1(0) & (1 << cipher_type)))
1646 packet_disconnect("Warning: client selects unsupported cipher.");
1648 /* Get check bytes from the packet. These must match those we
1649 sent earlier with the public key packet. */
1650 for (i = 0; i < 8; i++)
1651 if (cookie[i] != packet_get_char())
1652 packet_disconnect("IP Spoofing check bytes do not match.");
1654 debug("Encryption type: %.200s", cipher_name(cipher_type));
1656 /* Get the encrypted integer. */
1657 if ((session_key_int = BN_new()) == NULL)
1658 fatal("do_ssh1_kex: BN_new failed");
1659 packet_get_bignum(session_key_int);
1661 protocol_flags = packet_get_int();
1662 packet_set_protocol_flags(protocol_flags);
1665 /* Decrypt session_key_int using host/server keys */
1666 rsafail = PRIVSEP(ssh1_session_key(session_key_int));
1669 * Extract session key from the decrypted integer. The key is in the
1670 * least significant 256 bits of the integer; the first byte of the
1671 * key is in the highest bits.
1674 BN_mask_bits(session_key_int, sizeof(session_key) * 8);
1675 len = BN_num_bytes(session_key_int);
1676 if (len < 0 || len > sizeof(session_key)) {
1677 error("do_connection: bad session key len from %s: "
1678 "session_key_int %d > sizeof(session_key) %lu",
1679 get_remote_ipaddr(), len, (u_long)sizeof(session_key));
1682 memset(session_key, 0, sizeof(session_key));
1683 BN_bn2bin(session_key_int,
1684 session_key + sizeof(session_key) - len);
1686 compute_session_id(session_id, cookie,
1687 sensitive_data.ssh1_host_key->rsa->n,
1688 sensitive_data.server_key->rsa->n);
1690 * Xor the first 16 bytes of the session key with the
1693 for (i = 0; i < 16; i++)
1694 session_key[i] ^= session_id[i];
1698 int bytes = BN_num_bytes(session_key_int);
1699 u_char *buf = xmalloc(bytes);
1702 logit("do_connection: generating a fake encryption key");
1703 BN_bn2bin(session_key_int, buf);
1705 MD5_Update(&md, buf, bytes);
1706 MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
1707 MD5_Final(session_key, &md);
1709 MD5_Update(&md, session_key, 16);
1710 MD5_Update(&md, buf, bytes);
1711 MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
1712 MD5_Final(session_key + 16, &md);
1713 memset(buf, 0, bytes);
1715 for (i = 0; i < 16; i++)
1716 session_id[i] = session_key[i] ^ session_key[i + 16];
1718 /* Destroy the private and public keys. No longer. */
1719 destroy_sensitive_data();
1722 mm_ssh1_session_id(session_id);
1724 /* Destroy the decrypted integer. It is no longer needed. */
1725 BN_clear_free(session_key_int);
1727 /* Set the session key. From this on all communications will be encrypted. */
1728 packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type);
1730 /* Destroy our copy of the session key. It is no longer needed. */
1731 memset(session_key, 0, sizeof(session_key));
1733 debug("Received session key; encryption turned on.");
1735 /* Send an acknowledgment packet. Note that this packet is sent encrypted. */
1736 packet_start(SSH_SMSG_SUCCESS);
1738 packet_write_wait();
1742 * SSH2 key exchange: diffie-hellman-group1-sha1
1749 if (options.ciphers != NULL) {
1750 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1751 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
1753 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1754 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
1755 myproposal[PROPOSAL_ENC_ALGS_STOC] =
1756 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
1758 if (options.macs != NULL) {
1759 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
1760 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
1762 if (!options.compression) {
1763 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1764 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
1766 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types();
1768 /* start key exchange */
1769 kex = kex_setup(myproposal);
1770 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1771 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1773 kex->client_version_string=client_version_string;
1774 kex->server_version_string=server_version_string;
1775 kex->load_host_key=&get_hostkey_by_type;
1776 kex->host_key_index=&get_hostkey_index;
1780 dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1782 session_id2 = kex->session_id;
1783 session_id2_len = kex->session_id_len;
1786 /* send 1st encrypted/maced/compressed message */
1787 packet_start(SSH2_MSG_IGNORE);
1788 packet_put_cstring("markus");
1790 packet_write_wait();
1795 /* server specific fatal cleanup */
1800 do_cleanup(the_authctxt);