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 1.288 2004/03/03 06:47:52 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 = NULL;
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 if (use_privsep && pmonitor != NULL && pmonitor->m_pid > 0)
309 kill(pmonitor->m_pid, SIGALRM);
311 /* Log error and exit. */
312 fatal("Timeout before authentication for %s", get_remote_ipaddr());
316 * Signal handler for the key regeneration alarm. Note that this
317 * alarm only occurs in the daemon waiting for connections, and it does not
318 * do anything with the private key or random state before forking.
319 * Thus there should be no concurrency control/asynchronous execution
323 generate_ephemeral_server_key(void)
328 verbose("Generating %s%d bit RSA key.",
329 sensitive_data.server_key ? "new " : "", options.server_key_bits);
330 if (sensitive_data.server_key != NULL)
331 key_free(sensitive_data.server_key);
332 sensitive_data.server_key = key_generate(KEY_RSA1,
333 options.server_key_bits);
334 verbose("RSA key generation complete.");
336 for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) {
339 sensitive_data.ssh1_cookie[i] = rnd & 0xff;
346 key_regeneration_alarm(int sig)
348 int save_errno = errno;
350 signal(SIGALRM, SIG_DFL);
356 sshd_exchange_identification(int sock_in, int sock_out)
359 int remote_major, remote_minor;
362 char buf[256]; /* Must not be larger than remote_version. */
363 char remote_version[256]; /* Must be at least as big as buf. */
365 if ((options.protocol & SSH_PROTO_1) &&
366 (options.protocol & SSH_PROTO_2)) {
367 major = PROTOCOL_MAJOR_1;
369 } else if (options.protocol & SSH_PROTO_2) {
370 major = PROTOCOL_MAJOR_2;
371 minor = PROTOCOL_MINOR_2;
373 major = PROTOCOL_MAJOR_1;
374 minor = PROTOCOL_MINOR_1;
376 snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", major, minor, SSH_VERSION);
377 server_version_string = xstrdup(buf);
379 /* Send our protocol version identification. */
380 if (atomicio(vwrite, sock_out, server_version_string,
381 strlen(server_version_string))
382 != strlen(server_version_string)) {
383 logit("Could not write ident string to %s", get_remote_ipaddr());
387 /* Read other sides version identification. */
388 memset(buf, 0, sizeof(buf));
389 for (i = 0; i < sizeof(buf) - 1; i++) {
390 if (atomicio(read, sock_in, &buf[i], 1) != 1) {
391 logit("Did not receive identification string from %s",
392 get_remote_ipaddr());
395 if (buf[i] == '\r') {
397 /* Kludge for F-Secure Macintosh < 1.0.2 */
399 strncmp(buf, "SSH-1.5-W1.0", 12) == 0)
403 if (buf[i] == '\n') {
408 buf[sizeof(buf) - 1] = 0;
409 client_version_string = xstrdup(buf);
412 * Check that the versions match. In future this might accept
413 * several versions and set appropriate flags to handle them.
415 if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n",
416 &remote_major, &remote_minor, remote_version) != 3) {
417 s = "Protocol mismatch.\n";
418 (void) atomicio(vwrite, sock_out, s, strlen(s));
421 logit("Bad protocol version identification '%.100s' from %s",
422 client_version_string, get_remote_ipaddr());
425 debug("Client protocol version %d.%d; client software version %.100s",
426 remote_major, remote_minor, remote_version);
428 compat_datafellows(remote_version);
430 if (datafellows & SSH_BUG_PROBE) {
431 logit("probed from %s with %s. Don't panic.",
432 get_remote_ipaddr(), client_version_string);
436 if (datafellows & SSH_BUG_SCANNER) {
437 logit("scanned from %s with %s. Don't panic.",
438 get_remote_ipaddr(), client_version_string);
443 switch (remote_major) {
445 if (remote_minor == 99) {
446 if (options.protocol & SSH_PROTO_2)
452 if (!(options.protocol & SSH_PROTO_1)) {
456 if (remote_minor < 3) {
457 packet_disconnect("Your ssh version is too old and "
458 "is no longer supported. Please install a newer version.");
459 } else if (remote_minor == 3) {
460 /* note that this disables agent-forwarding */
465 if (options.protocol & SSH_PROTO_2) {
474 chop(server_version_string);
475 debug("Local version string %.200s", server_version_string);
478 s = "Protocol major versions differ.\n";
479 (void) atomicio(vwrite, sock_out, s, strlen(s));
482 logit("Protocol major versions differ for %s: %.200s vs. %.200s",
484 server_version_string, client_version_string);
489 /* Destroy the host and server keys. They will no longer be needed. */
491 destroy_sensitive_data(void)
495 if (sensitive_data.server_key) {
496 key_free(sensitive_data.server_key);
497 sensitive_data.server_key = NULL;
499 for (i = 0; i < options.num_host_key_files; i++) {
500 if (sensitive_data.host_keys[i]) {
501 key_free(sensitive_data.host_keys[i]);
502 sensitive_data.host_keys[i] = NULL;
505 sensitive_data.ssh1_host_key = NULL;
506 memset(sensitive_data.ssh1_cookie, 0, SSH_SESSION_KEY_LENGTH);
509 /* Demote private to public keys for network child */
511 demote_sensitive_data(void)
516 if (sensitive_data.server_key) {
517 tmp = key_demote(sensitive_data.server_key);
518 key_free(sensitive_data.server_key);
519 sensitive_data.server_key = tmp;
522 for (i = 0; i < options.num_host_key_files; i++) {
523 if (sensitive_data.host_keys[i]) {
524 tmp = key_demote(sensitive_data.host_keys[i]);
525 key_free(sensitive_data.host_keys[i]);
526 sensitive_data.host_keys[i] = tmp;
527 if (tmp->type == KEY_RSA1)
528 sensitive_data.ssh1_host_key = tmp;
532 /* We do not clear ssh1_host key and cookie. XXX - Okay Niels? */
536 privsep_preauth_child(void)
543 /* Enable challenge-response authentication for privilege separation */
544 privsep_challenge_enable();
546 for (i = 0; i < 256; i++)
547 rnd[i] = arc4random();
548 RAND_seed(rnd, sizeof(rnd));
550 /* Demote the private keys to public keys. */
551 demote_sensitive_data();
553 if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
554 fatal("Privilege separation user %s does not exist",
556 memset(pw->pw_passwd, 0, strlen(pw->pw_passwd));
559 /* Change our root directory */
560 if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1)
561 fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR,
563 if (chdir("/") == -1)
564 fatal("chdir(\"/\"): %s", strerror(errno));
566 /* Drop our privileges */
567 debug3("privsep user:group %u:%u", (u_int)pw->pw_uid,
570 /* XXX not ready, too heavy after chroot */
571 do_setusercontext(pw);
573 gidset[0] = pw->pw_gid;
574 if (setgroups(1, gidset) < 0)
575 fatal("setgroups: %.100s", strerror(errno));
576 permanently_set_uid(pw);
581 privsep_preauth(Authctxt *authctxt)
586 /* Set up unprivileged child process to deal with network data */
587 pmonitor = monitor_init();
588 /* Store a pointer to the kex for later rekeying */
589 pmonitor->m_pkex = &xxx_kex;
593 fatal("fork of unprivileged child failed");
594 } else if (pid != 0) {
595 debug2("Network child is on pid %ld", (long)pid);
597 close(pmonitor->m_recvfd);
598 pmonitor->m_pid = pid;
599 monitor_child_preauth(authctxt, pmonitor);
600 close(pmonitor->m_sendfd);
603 monitor_sync(pmonitor);
605 /* Wait for the child's exit status */
606 while (waitpid(pid, &status, 0) < 0)
613 close(pmonitor->m_sendfd);
615 /* Demote the child */
616 if (getuid() == 0 || geteuid() == 0)
617 privsep_preauth_child();
618 setproctitle("%s", "[net]");
624 privsep_postauth(Authctxt *authctxt)
626 #ifdef DISABLE_FD_PASSING
629 if (authctxt->pw->pw_uid == 0 || options.use_login) {
631 /* File descriptor passing is broken or root login */
632 monitor_apply_keystate(pmonitor);
637 /* Authentication complete */
639 if (startup_pipe != -1) {
644 /* New socket pair */
645 monitor_reinit(pmonitor);
647 pmonitor->m_pid = fork();
648 if (pmonitor->m_pid == -1)
649 fatal("fork of unprivileged child failed");
650 else if (pmonitor->m_pid != 0) {
651 debug2("User child is on pid %ld", (long)pmonitor->m_pid);
652 close(pmonitor->m_recvfd);
653 monitor_child_postauth(pmonitor);
659 close(pmonitor->m_sendfd);
661 /* Demote the private keys to public keys. */
662 demote_sensitive_data();
664 /* Drop privileges */
665 do_setusercontext(authctxt->pw);
667 /* It is safe now to apply the key state */
668 monitor_apply_keystate(pmonitor);
672 list_hostkey_types(void)
680 for (i = 0; i < options.num_host_key_files; i++) {
681 Key *key = sensitive_data.host_keys[i];
687 if (buffer_len(&b) > 0)
688 buffer_append(&b, ",", 1);
689 p = key_ssh_name(key);
690 buffer_append(&b, p, strlen(p));
694 buffer_append(&b, "\0", 1);
695 ret = xstrdup(buffer_ptr(&b));
697 debug("list_hostkey_types: %s", ret);
702 get_hostkey_by_type(int type)
706 for (i = 0; i < options.num_host_key_files; i++) {
707 Key *key = sensitive_data.host_keys[i];
708 if (key != NULL && key->type == type)
715 get_hostkey_by_index(int ind)
717 if (ind < 0 || ind >= options.num_host_key_files)
719 return (sensitive_data.host_keys[ind]);
723 get_hostkey_index(Key *key)
727 for (i = 0; i < options.num_host_key_files; i++) {
728 if (key == sensitive_data.host_keys[i])
735 * returns 1 if connection should be dropped, 0 otherwise.
736 * dropping starts at connection #max_startups_begin with a probability
737 * of (max_startups_rate/100). the probability increases linearly until
738 * all connections are dropped for startups > max_startups
741 drop_connection(int startups)
745 if (startups < options.max_startups_begin)
747 if (startups >= options.max_startups)
749 if (options.max_startups_rate == 100)
752 p = 100 - options.max_startups_rate;
753 p *= startups - options.max_startups_begin;
754 p /= (double) (options.max_startups - options.max_startups_begin);
755 p += options.max_startups_rate;
757 r = arc4random() / (double) UINT_MAX;
759 debug("drop_connection: p %g, r %g", p, r);
760 return (r < p) ? 1 : 0;
766 fprintf(stderr, "sshd version %s, %s\n",
767 SSH_VERSION, SSLeay_version(SSLEAY_VERSION));
768 fprintf(stderr, "Usage: %s [options]\n", __progname);
769 fprintf(stderr, "Options:\n");
770 fprintf(stderr, " -f file Configuration file (default %s)\n", _PATH_SERVER_CONFIG_FILE);
771 fprintf(stderr, " -d Debugging mode (multiple -d means more debugging)\n");
772 fprintf(stderr, " -i Started from inetd\n");
773 fprintf(stderr, " -D Do not fork into daemon mode\n");
774 fprintf(stderr, " -t Only test configuration file and keys\n");
775 fprintf(stderr, " -q Quiet (no logging)\n");
776 fprintf(stderr, " -p port Listen on the specified port (default: 22)\n");
777 fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n");
778 fprintf(stderr, " -g seconds Grace period for authentication (default: 600)\n");
779 fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n");
780 fprintf(stderr, " -h file File from which to read host key (default: %s)\n",
781 _PATH_HOST_KEY_FILE);
782 fprintf(stderr, " -u len Maximum hostname length for utmp recording\n");
783 fprintf(stderr, " -4 Use IPv4 only\n");
784 fprintf(stderr, " -6 Use IPv6 only\n");
785 fprintf(stderr, " -o option Process the option as if it was read from a configuration file.\n");
790 * Main program for the daemon.
793 main(int ac, char **av)
797 int opt, sock_in = 0, sock_out = 0, newsock, j, i, fdsetsz, on = 1;
801 struct sockaddr_storage from;
802 const char *remote_ip;
806 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
808 int listen_sock, maxfd;
813 int ret, key_used = 0;
815 #ifdef HAVE_SECUREWARE
816 (void)set_auth_parameters(ac, av);
818 __progname = ssh_get_progname(av[0]);
821 /* Save argv. Duplicate so setproctitle emulation doesn't clobber it */
823 saved_argv = xmalloc(sizeof(*saved_argv) * (ac + 1));
824 for (i = 0; i < ac; i++)
825 saved_argv[i] = xstrdup(av[i]);
826 saved_argv[i] = NULL;
828 #ifndef HAVE_SETPROCTITLE
829 /* Prepare for later setproctitle emulation */
830 compat_init_setproctitle(ac, av);
834 /* Initialize configuration options to their default values. */
835 initialize_server_options(&options);
837 /* Parse command-line arguments. */
838 while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:dDeiqtQ46")) != -1) {
847 config_file_name = optarg;
850 if (debug_flag == 0) {
852 options.log_level = SYSLOG_LEVEL_DEBUG1;
853 } else if (options.log_level < SYSLOG_LEVEL_DEBUG3)
869 options.log_level = SYSLOG_LEVEL_QUIET;
872 options.server_key_bits = atoi(optarg);
875 options.ports_from_cmdline = 1;
876 if (options.num_ports >= MAX_PORTS) {
877 fprintf(stderr, "too many ports.\n");
880 options.ports[options.num_ports++] = a2port(optarg);
881 if (options.ports[options.num_ports-1] == 0) {
882 fprintf(stderr, "Bad port number.\n");
887 if ((options.login_grace_time = convtime(optarg)) == -1) {
888 fprintf(stderr, "Invalid login grace time.\n");
893 if ((options.key_regeneration_time = convtime(optarg)) == -1) {
894 fprintf(stderr, "Invalid key regeneration interval.\n");
899 if (options.num_host_key_files >= MAX_HOSTKEYS) {
900 fprintf(stderr, "too many host keys.\n");
903 options.host_key_files[options.num_host_key_files++] = optarg;
909 utmp_len = atoi(optarg);
910 if (utmp_len > MAXHOSTNAMELEN) {
911 fprintf(stderr, "Invalid utmp length.\n");
916 line = xstrdup(optarg);
917 if (process_server_config_line(&options, line,
918 "command-line", 0) != 0)
928 SSLeay_add_all_algorithms();
929 channel_set_af(IPv4or6);
932 * Force logging to stderr until we have loaded the private host
933 * key (unless started from inetd)
936 options.log_level == SYSLOG_LEVEL_NOT_SET ?
937 SYSLOG_LEVEL_INFO : options.log_level,
938 options.log_facility == SYSLOG_FACILITY_NOT_SET ?
939 SYSLOG_FACILITY_AUTH : options.log_facility,
940 log_stderr || !inetd_flag);
944 * Unset KRB5CCNAME, otherwise the user's session may inherit it from
947 unsetenv("KRB5CCNAME");
950 /* Cray can define user privs drop all prives now!
951 * Not needed on PRIV_SU systems!
958 /* Read server configuration options from the configuration file. */
959 read_server_config(&options, config_file_name);
961 /* Fill in default values for those options not explicitly set. */
962 fill_default_server_options(&options);
964 /* Check that there are no remaining arguments. */
966 fprintf(stderr, "Extra argument %s.\n", av[optind]);
970 debug("sshd version %.100s", SSH_VERSION);
972 /* load private host keys */
973 sensitive_data.host_keys = xmalloc(options.num_host_key_files *
975 for (i = 0; i < options.num_host_key_files; i++)
976 sensitive_data.host_keys[i] = NULL;
977 sensitive_data.server_key = NULL;
978 sensitive_data.ssh1_host_key = NULL;
979 sensitive_data.have_ssh1_key = 0;
980 sensitive_data.have_ssh2_key = 0;
982 for (i = 0; i < options.num_host_key_files; i++) {
983 key = key_load_private(options.host_key_files[i], "", NULL);
984 sensitive_data.host_keys[i] = key;
986 error("Could not load host key: %s",
987 options.host_key_files[i]);
988 sensitive_data.host_keys[i] = NULL;
993 sensitive_data.ssh1_host_key = key;
994 sensitive_data.have_ssh1_key = 1;
998 sensitive_data.have_ssh2_key = 1;
1001 debug("private host key: #%d type %d %s", i, key->type,
1004 if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) {
1005 logit("Disabling protocol version 1. Could not load host key");
1006 options.protocol &= ~SSH_PROTO_1;
1008 if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) {
1009 logit("Disabling protocol version 2. Could not load host key");
1010 options.protocol &= ~SSH_PROTO_2;
1012 if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
1013 logit("sshd: no hostkeys available -- exiting.");
1017 /* Check certain values for sanity. */
1018 if (options.protocol & SSH_PROTO_1) {
1019 if (options.server_key_bits < 512 ||
1020 options.server_key_bits > 32768) {
1021 fprintf(stderr, "Bad server key size.\n");
1025 * Check that server and host key lengths differ sufficiently. This
1026 * is necessary to make double encryption work with rsaref. Oh, I
1027 * hate software patents. I dont know if this can go? Niels
1029 if (options.server_key_bits >
1030 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) -
1031 SSH_KEY_BITS_RESERVED && options.server_key_bits <
1032 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
1033 SSH_KEY_BITS_RESERVED) {
1034 options.server_key_bits =
1035 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
1036 SSH_KEY_BITS_RESERVED;
1037 debug("Forcing server key to %d bits to make it differ from host key.",
1038 options.server_key_bits);
1046 if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL)
1047 fatal("Privilege separation user %s does not exist",
1049 if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) ||
1050 (S_ISDIR(st.st_mode) == 0))
1051 fatal("Missing privilege separation directory: %s",
1052 _PATH_PRIVSEP_CHROOT_DIR);
1055 if (check_ntsec(_PATH_PRIVSEP_CHROOT_DIR) &&
1056 (st.st_uid != getuid () ||
1057 (st.st_mode & (S_IWGRP|S_IWOTH)) != 0))
1059 if (st.st_uid != 0 || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)
1061 fatal("%s must be owned by root and not group or "
1062 "world-writable.", _PATH_PRIVSEP_CHROOT_DIR);
1065 /* Configuration looks good, so exit if in test mode. */
1070 * Clear out any supplemental groups we may have inherited. This
1071 * prevents inadvertent creation of files with bad modes (in the
1072 * portable version at least, it's certainly possible for PAM
1073 * to create a file, and we can't control the code in every
1074 * module which might be used).
1076 if (setgroups(0, NULL) < 0)
1077 debug("setgroups() failed: %.200s", strerror(errno));
1079 /* Initialize the log (it is reinitialized below in case we forked). */
1080 if (debug_flag && !inetd_flag)
1082 log_init(__progname, options.log_level, options.log_facility, log_stderr);
1085 * If not in debugging mode, and not started from inetd, disconnect
1086 * from the controlling terminal, and fork. The original process
1089 if (!(debug_flag || inetd_flag || no_daemon_flag)) {
1092 #endif /* TIOCNOTTY */
1093 if (daemon(0, 0) < 0)
1094 fatal("daemon() failed: %.200s", strerror(errno));
1096 /* Disconnect from the controlling tty. */
1098 fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
1100 (void) ioctl(fd, TIOCNOTTY, NULL);
1103 #endif /* TIOCNOTTY */
1105 /* Reinitialize the log (because of the fork above). */
1106 log_init(__progname, options.log_level, options.log_facility, log_stderr);
1108 /* Initialize the random number generator. */
1111 /* Chdir to the root directory so that the current disk can be
1112 unmounted if desired. */
1115 /* ignore SIGPIPE */
1116 signal(SIGPIPE, SIG_IGN);
1118 /* Start listening for a socket, unless started from inetd. */
1121 s1 = dup(0); /* Make sure descriptors 0, 1, and 2 are in use. */
1127 * We intentionally do not close the descriptors 0, 1, and 2
1128 * as our code for setting the descriptors won\'t work if
1129 * ttyfd happens to be one of those.
1131 debug("inetd sockets after dupping: %d, %d", sock_in, sock_out);
1132 if (options.protocol & SSH_PROTO_1)
1133 generate_ephemeral_server_key();
1135 for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
1136 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1138 if (num_listen_socks >= MAX_LISTEN_SOCKS)
1139 fatal("Too many listen sockets. "
1140 "Enlarge MAX_LISTEN_SOCKS");
1141 if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
1142 ntop, sizeof(ntop), strport, sizeof(strport),
1143 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1144 error("getnameinfo failed");
1147 /* Create socket for listening. */
1148 listen_sock = socket(ai->ai_family, ai->ai_socktype,
1150 if (listen_sock < 0) {
1151 /* kernel may not support ipv6 */
1152 verbose("socket: %.100s", strerror(errno));
1155 if (fcntl(listen_sock, F_SETFL, O_NONBLOCK) < 0) {
1156 error("listen_sock O_NONBLOCK: %s", strerror(errno));
1161 * Set socket options.
1162 * Allow local port reuse in TIME_WAIT.
1164 if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
1165 &on, sizeof(on)) == -1)
1166 error("setsockopt SO_REUSEADDR: %s", strerror(errno));
1168 debug("Bind to port %s on %s.", strport, ntop);
1170 /* Bind the socket to the desired port. */
1171 if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1173 error("Bind to port %s on %s failed: %.200s.",
1174 strport, ntop, strerror(errno));
1178 listen_socks[num_listen_socks] = listen_sock;
1181 /* Start listening on the port. */
1182 logit("Server listening on %s port %s.", ntop, strport);
1183 if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0)
1184 fatal("listen: %.100s", strerror(errno));
1187 freeaddrinfo(options.listen_addrs);
1189 if (!num_listen_socks)
1190 fatal("Cannot bind any address.");
1192 if (options.protocol & SSH_PROTO_1)
1193 generate_ephemeral_server_key();
1196 * Arrange to restart on SIGHUP. The handler needs
1199 signal(SIGHUP, sighup_handler);
1201 signal(SIGTERM, sigterm_handler);
1202 signal(SIGQUIT, sigterm_handler);
1204 /* Arrange SIGCHLD to be caught. */
1205 signal(SIGCHLD, main_sigchld_handler);
1207 /* Write out the pid file after the sigterm handler is setup */
1210 * Record our pid in /var/run/sshd.pid to make it
1211 * easier to kill the correct sshd. We don't want to
1212 * do this before the bind above because the bind will
1213 * fail if there already is a daemon, and this will
1214 * overwrite any old pid in the file.
1216 f = fopen(options.pid_file, "wb");
1218 error("Couldn't create pid file \"%s\": %s",
1219 options.pid_file, strerror(errno));
1221 fprintf(f, "%ld\n", (long) getpid());
1226 /* setup fd set for listen */
1229 for (i = 0; i < num_listen_socks; i++)
1230 if (listen_socks[i] > maxfd)
1231 maxfd = listen_socks[i];
1232 /* pipes connected to unauthenticated childs */
1233 startup_pipes = xmalloc(options.max_startups * sizeof(int));
1234 for (i = 0; i < options.max_startups; i++)
1235 startup_pipes[i] = -1;
1238 * Stay listening for connections until the system crashes or
1239 * the daemon is killed with a signal.
1242 if (received_sighup)
1246 fdsetsz = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask);
1247 fdset = (fd_set *)xmalloc(fdsetsz);
1248 memset(fdset, 0, fdsetsz);
1250 for (i = 0; i < num_listen_socks; i++)
1251 FD_SET(listen_socks[i], fdset);
1252 for (i = 0; i < options.max_startups; i++)
1253 if (startup_pipes[i] != -1)
1254 FD_SET(startup_pipes[i], fdset);
1256 /* Wait in select until there is a connection. */
1257 ret = select(maxfd+1, fdset, NULL, NULL, NULL);
1258 if (ret < 0 && errno != EINTR)
1259 error("select: %.100s", strerror(errno));
1260 if (received_sigterm) {
1261 logit("Received signal %d; terminating.",
1262 (int) received_sigterm);
1263 close_listen_socks();
1264 unlink(options.pid_file);
1267 if (key_used && key_do_regen) {
1268 generate_ephemeral_server_key();
1275 for (i = 0; i < options.max_startups; i++)
1276 if (startup_pipes[i] != -1 &&
1277 FD_ISSET(startup_pipes[i], fdset)) {
1279 * the read end of the pipe is ready
1280 * if the child has closed the pipe
1281 * after successful authentication
1282 * or if the child has died
1284 close(startup_pipes[i]);
1285 startup_pipes[i] = -1;
1288 for (i = 0; i < num_listen_socks; i++) {
1289 if (!FD_ISSET(listen_socks[i], fdset))
1291 fromlen = sizeof(from);
1292 newsock = accept(listen_socks[i], (struct sockaddr *)&from,
1295 if (errno != EINTR && errno != EWOULDBLOCK)
1296 error("accept: %.100s", strerror(errno));
1299 if (fcntl(newsock, F_SETFL, 0) < 0) {
1300 error("newsock del O_NONBLOCK: %s", strerror(errno));
1304 if (drop_connection(startups) == 1) {
1305 debug("drop connection #%d", startups);
1309 if (pipe(startup_p) == -1) {
1314 for (j = 0; j < options.max_startups; j++)
1315 if (startup_pipes[j] == -1) {
1316 startup_pipes[j] = startup_p[0];
1317 if (maxfd < startup_p[0])
1318 maxfd = startup_p[0];
1324 * Got connection. Fork a child to handle it, unless
1325 * we are in debugging mode.
1329 * In debugging mode. Close the listening
1330 * socket, and start processing the
1331 * connection without forking.
1333 debug("Server will not fork when running in debugging mode.");
1334 close_listen_socks();
1342 * Normal production daemon. Fork, and have
1343 * the child process the connection. The
1344 * parent continues listening.
1346 if ((pid = fork()) == 0) {
1348 * Child. Close the listening and max_startup
1349 * sockets. Start using the accepted socket.
1350 * Reinitialize logging (since our pid has
1351 * changed). We break out of the loop to handle
1354 startup_pipe = startup_p[1];
1355 close_startup_pipes();
1356 close_listen_socks();
1359 log_init(__progname, options.log_level, options.log_facility, log_stderr);
1364 /* Parent. Stay in the loop. */
1366 error("fork: %.100s", strerror(errno));
1368 debug("Forked child %ld.", (long)pid);
1370 close(startup_p[1]);
1372 /* Mark that the key has been used (it was "given" to the child). */
1373 if ((options.protocol & SSH_PROTO_1) &&
1375 /* Schedule server key regeneration alarm. */
1376 signal(SIGALRM, key_regeneration_alarm);
1377 alarm(options.key_regeneration_time);
1383 /* Close the new socket (the child is now taking care of it). */
1386 /* child process check (or debug mode) */
1387 if (num_listen_socks < 0)
1392 /* This is the child processing a new connection. */
1393 setproctitle("%s", "[accepted]");
1396 * Create a new session and process group since the 4.4BSD
1397 * setlogin() affects the entire process group. We don't
1398 * want the child to be able to affect the parent.
1400 #if !defined(SSHD_ACQUIRES_CTTY)
1402 * If setsid is called, on some platforms sshd will later acquire a
1403 * controlling terminal which will result in "could not set
1404 * controlling tty" errors.
1406 if (!debug_flag && !inetd_flag && setsid() < 0)
1407 error("setsid: %.100s", strerror(errno));
1411 * Disable the key regeneration alarm. We will not regenerate the
1412 * key since we are no longer in a position to give it to anyone. We
1413 * will not restart on SIGHUP since it no longer makes sense.
1416 signal(SIGALRM, SIG_DFL);
1417 signal(SIGHUP, SIG_DFL);
1418 signal(SIGTERM, SIG_DFL);
1419 signal(SIGQUIT, SIG_DFL);
1420 signal(SIGCHLD, SIG_DFL);
1421 signal(SIGINT, SIG_DFL);
1423 /* Set SO_KEEPALIVE if requested. */
1424 if (options.tcp_keep_alive &&
1425 setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on,
1427 error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1430 * Register our connection. This turns encryption off because we do
1433 packet_set_connection(sock_in, sock_out);
1435 remote_port = get_remote_port();
1436 remote_ip = get_remote_ipaddr();
1439 /* Check whether logins are denied from this host. */
1441 struct request_info req;
1443 request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0);
1446 if (!hosts_access(&req)) {
1447 debug("Connection refused by tcp wrapper");
1450 fatal("libwrap refuse returns");
1453 #endif /* LIBWRAP */
1455 /* Log the connection. */
1456 verbose("Connection from %.500s port %d", remote_ip, remote_port);
1459 * We don\'t want to listen forever unless the other side
1460 * successfully authenticates itself. So we set up an alarm which is
1461 * cleared after successful authentication. A limit of zero
1462 * indicates no limit. Note that we don\'t set the alarm in debugging
1463 * mode; it is just annoying to have the server exit just when you
1464 * are about to discover the bug.
1466 signal(SIGALRM, grace_alarm_handler);
1468 alarm(options.login_grace_time);
1470 sshd_exchange_identification(sock_in, sock_out);
1472 packet_set_nonblocking();
1474 /* prepare buffers to collect authentication messages */
1475 buffer_init(&loginmsg);
1477 /* allocate authentication context */
1478 authctxt = xmalloc(sizeof(*authctxt));
1479 memset(authctxt, 0, sizeof(*authctxt));
1481 /* XXX global for cleanup, access from other modules */
1482 the_authctxt = authctxt;
1485 if (privsep_preauth(authctxt) == 1)
1488 /* perform the key exchange */
1489 /* authenticate user and start session */
1492 do_authentication2(authctxt);
1495 do_authentication(authctxt);
1498 * If we use privilege separation, the unprivileged child transfers
1499 * the current keystate and exits
1502 mm_send_keystate(pmonitor);
1508 * In privilege separation, we fork another child and prepare
1509 * file descriptor passing.
1512 privsep_postauth(authctxt);
1513 /* the monitor process [priv] will not return */
1515 destroy_sensitive_data();
1518 /* Start session. */
1519 do_authenticated(authctxt);
1521 /* The connection has been terminated. */
1522 verbose("Closing connection to %.100s", remote_ip);
1525 if (options.use_pam)
1527 #endif /* USE_PAM */
1538 * Decrypt session_key_int using our private server key and private host key
1539 * (key with larger modulus first).
1542 ssh1_session_key(BIGNUM *session_key_int)
1546 if (BN_cmp(sensitive_data.server_key->rsa->n, sensitive_data.ssh1_host_key->rsa->n) > 0) {
1547 /* Server key has bigger modulus. */
1548 if (BN_num_bits(sensitive_data.server_key->rsa->n) <
1549 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
1550 fatal("do_connection: %s: server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
1551 get_remote_ipaddr(),
1552 BN_num_bits(sensitive_data.server_key->rsa->n),
1553 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
1554 SSH_KEY_BITS_RESERVED);
1556 if (rsa_private_decrypt(session_key_int, session_key_int,
1557 sensitive_data.server_key->rsa) <= 0)
1559 if (rsa_private_decrypt(session_key_int, session_key_int,
1560 sensitive_data.ssh1_host_key->rsa) <= 0)
1563 /* Host key has bigger modulus (or they are equal). */
1564 if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) <
1565 BN_num_bits(sensitive_data.server_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
1566 fatal("do_connection: %s: host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d",
1567 get_remote_ipaddr(),
1568 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
1569 BN_num_bits(sensitive_data.server_key->rsa->n),
1570 SSH_KEY_BITS_RESERVED);
1572 if (rsa_private_decrypt(session_key_int, session_key_int,
1573 sensitive_data.ssh1_host_key->rsa) < 0)
1575 if (rsa_private_decrypt(session_key_int, session_key_int,
1576 sensitive_data.server_key->rsa) < 0)
1589 BIGNUM *session_key_int;
1590 u_char session_key[SSH_SESSION_KEY_LENGTH];
1592 u_int cipher_type, auth_mask, protocol_flags;
1596 * Generate check bytes that the client must send back in the user
1597 * packet in order for it to be accepted; this is used to defy ip
1598 * spoofing attacks. Note that this only works against somebody
1599 * doing IP spoofing from a remote machine; any machine on the local
1600 * network can still see outgoing packets and catch the random
1601 * cookie. This only affects rhosts authentication, and this is one
1602 * of the reasons why it is inherently insecure.
1604 for (i = 0; i < 8; i++) {
1607 cookie[i] = rnd & 0xff;
1612 * Send our public key. We include in the packet 64 bits of random
1613 * data that must be matched in the reply in order to prevent IP
1616 packet_start(SSH_SMSG_PUBLIC_KEY);
1617 for (i = 0; i < 8; i++)
1618 packet_put_char(cookie[i]);
1620 /* Store our public server RSA key. */
1621 packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n));
1622 packet_put_bignum(sensitive_data.server_key->rsa->e);
1623 packet_put_bignum(sensitive_data.server_key->rsa->n);
1625 /* Store our public host RSA key. */
1626 packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
1627 packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e);
1628 packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n);
1630 /* Put protocol flags. */
1631 packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN);
1633 /* Declare which ciphers we support. */
1634 packet_put_int(cipher_mask_ssh1(0));
1636 /* Declare supported authentication types. */
1638 if (options.rhosts_rsa_authentication)
1639 auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA;
1640 if (options.rsa_authentication)
1641 auth_mask |= 1 << SSH_AUTH_RSA;
1642 if (options.challenge_response_authentication == 1)
1643 auth_mask |= 1 << SSH_AUTH_TIS;
1644 if (options.password_authentication)
1645 auth_mask |= 1 << SSH_AUTH_PASSWORD;
1646 packet_put_int(auth_mask);
1648 /* Send the packet and wait for it to be sent. */
1650 packet_write_wait();
1652 debug("Sent %d bit server key and %d bit host key.",
1653 BN_num_bits(sensitive_data.server_key->rsa->n),
1654 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
1656 /* Read clients reply (cipher type and session key). */
1657 packet_read_expect(SSH_CMSG_SESSION_KEY);
1659 /* Get cipher type and check whether we accept this. */
1660 cipher_type = packet_get_char();
1662 if (!(cipher_mask_ssh1(0) & (1 << cipher_type)))
1663 packet_disconnect("Warning: client selects unsupported cipher.");
1665 /* Get check bytes from the packet. These must match those we
1666 sent earlier with the public key packet. */
1667 for (i = 0; i < 8; i++)
1668 if (cookie[i] != packet_get_char())
1669 packet_disconnect("IP Spoofing check bytes do not match.");
1671 debug("Encryption type: %.200s", cipher_name(cipher_type));
1673 /* Get the encrypted integer. */
1674 if ((session_key_int = BN_new()) == NULL)
1675 fatal("do_ssh1_kex: BN_new failed");
1676 packet_get_bignum(session_key_int);
1678 protocol_flags = packet_get_int();
1679 packet_set_protocol_flags(protocol_flags);
1682 /* Decrypt session_key_int using host/server keys */
1683 rsafail = PRIVSEP(ssh1_session_key(session_key_int));
1686 * Extract session key from the decrypted integer. The key is in the
1687 * least significant 256 bits of the integer; the first byte of the
1688 * key is in the highest bits.
1691 BN_mask_bits(session_key_int, sizeof(session_key) * 8);
1692 len = BN_num_bytes(session_key_int);
1693 if (len < 0 || len > sizeof(session_key)) {
1694 error("do_connection: bad session key len from %s: "
1695 "session_key_int %d > sizeof(session_key) %lu",
1696 get_remote_ipaddr(), len, (u_long)sizeof(session_key));
1699 memset(session_key, 0, sizeof(session_key));
1700 BN_bn2bin(session_key_int,
1701 session_key + sizeof(session_key) - len);
1703 compute_session_id(session_id, cookie,
1704 sensitive_data.ssh1_host_key->rsa->n,
1705 sensitive_data.server_key->rsa->n);
1707 * Xor the first 16 bytes of the session key with the
1710 for (i = 0; i < 16; i++)
1711 session_key[i] ^= session_id[i];
1715 int bytes = BN_num_bytes(session_key_int);
1716 u_char *buf = xmalloc(bytes);
1719 logit("do_connection: generating a fake encryption key");
1720 BN_bn2bin(session_key_int, buf);
1722 MD5_Update(&md, buf, bytes);
1723 MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
1724 MD5_Final(session_key, &md);
1726 MD5_Update(&md, session_key, 16);
1727 MD5_Update(&md, buf, bytes);
1728 MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
1729 MD5_Final(session_key + 16, &md);
1730 memset(buf, 0, bytes);
1732 for (i = 0; i < 16; i++)
1733 session_id[i] = session_key[i] ^ session_key[i + 16];
1735 /* Destroy the private and public keys. No longer. */
1736 destroy_sensitive_data();
1739 mm_ssh1_session_id(session_id);
1741 /* Destroy the decrypted integer. It is no longer needed. */
1742 BN_clear_free(session_key_int);
1744 /* Set the session key. From this on all communications will be encrypted. */
1745 packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type);
1747 /* Destroy our copy of the session key. It is no longer needed. */
1748 memset(session_key, 0, sizeof(session_key));
1750 debug("Received session key; encryption turned on.");
1752 /* Send an acknowledgment packet. Note that this packet is sent encrypted. */
1753 packet_start(SSH_SMSG_SUCCESS);
1755 packet_write_wait();
1759 * SSH2 key exchange: diffie-hellman-group1-sha1
1766 if (options.ciphers != NULL) {
1767 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1768 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
1770 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1771 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
1772 myproposal[PROPOSAL_ENC_ALGS_STOC] =
1773 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
1775 if (options.macs != NULL) {
1776 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
1777 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
1779 if (!options.compression) {
1780 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1781 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
1783 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types();
1785 /* start key exchange */
1786 kex = kex_setup(myproposal);
1787 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
1788 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
1790 kex->client_version_string=client_version_string;
1791 kex->server_version_string=server_version_string;
1792 kex->load_host_key=&get_hostkey_by_type;
1793 kex->host_key_index=&get_hostkey_index;
1797 dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1799 session_id2 = kex->session_id;
1800 session_id2_len = kex->session_id_len;
1803 /* send 1st encrypted/maced/compressed message */
1804 packet_start(SSH2_MSG_IGNORE);
1805 packet_put_cstring("markus");
1807 packet_write_wait();
1812 /* server specific fatal cleanup */
1817 do_cleanup(the_authctxt);