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 1.260 2002/09/27 10:42:09 mickey 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.
116 int IPv4or6 = AF_INET;
118 int IPv4or6 = AF_UNSPEC;
122 * Debug mode flag. This can be set on the command line. If debug
123 * mode is enabled, extra debugging output will be sent to the system
124 * log, the daemon will not go to background, and will exit after processing
125 * the first connection.
129 /* Flag indicating that the daemon should only test the configuration and keys. */
132 /* Flag indicating that the daemon is being started from inetd. */
135 /* Flag indicating that sshd should not detach and become a daemon. */
136 int no_daemon_flag = 0;
138 /* debug goes to stderr unless inetd_flag is set */
141 /* Saved arguments to main(). */
146 * The sockets that the server is listening; this is used in the SIGHUP
149 #define MAX_LISTEN_SOCKS 16
150 int listen_socks[MAX_LISTEN_SOCKS];
151 int num_listen_socks = 0;
154 * the client's version string, passed by sshd2 in compat mode. if != NULL,
155 * sshd will skip the version-number exchange
157 char *client_version_string = NULL;
158 char *server_version_string = NULL;
160 /* for rekeying XXX fixme */
164 * Any really sensitive data in the application is contained in this
165 * structure. The idea is that this structure could be locked into memory so
166 * that the pages do not get written into swap. However, there are some
167 * problems. The private key contains BIGNUMs, and we do not (in principle)
168 * have access to the internals of them, and locking just the structure is
169 * not very useful. Currently, memory locking is not implemented.
172 Key *server_key; /* ephemeral server key */
173 Key *ssh1_host_key; /* ssh1 host key */
174 Key **host_keys; /* all private host keys */
177 u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH];
181 * Flag indicating whether the RSA server key needs to be regenerated.
182 * Is set in the SIGALRM handler and cleared when the key is regenerated.
184 static volatile sig_atomic_t key_do_regen = 0;
186 /* This is set to true when a signal is received. */
187 static volatile sig_atomic_t received_sighup = 0;
188 static volatile sig_atomic_t received_sigterm = 0;
190 /* session identifier, used by RSA-auth */
191 u_char session_id[16];
194 u_char *session_id2 = NULL;
195 int session_id2_len = 0;
197 /* record remote hostname or ip */
198 u_int utmp_len = MAXHOSTNAMELEN;
200 /* options.max_startup sized array of fd ints */
201 int *startup_pipes = NULL;
202 int startup_pipe; /* in child */
204 /* variables used for privilege separation */
205 extern struct monitor *pmonitor;
206 extern int use_privsep;
208 /* Prototypes for various functions defined later in this file. */
209 void destroy_sensitive_data(void);
210 void demote_sensitive_data(void);
212 static void do_ssh1_kex(void);
213 static void do_ssh2_kex(void);
216 * Close all listening sockets
219 close_listen_socks(void)
223 for (i = 0; i < num_listen_socks; i++)
224 close(listen_socks[i]);
225 num_listen_socks = -1;
229 close_startup_pipes(void)
234 for (i = 0; i < options.max_startups; i++)
235 if (startup_pipes[i] != -1)
236 close(startup_pipes[i]);
240 * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP;
241 * the effect is to reread the configuration file (and to regenerate
245 sighup_handler(int sig)
247 int save_errno = errno;
250 signal(SIGHUP, sighup_handler);
255 * Called from the main program after receiving SIGHUP.
256 * Restarts the server.
261 log("Received SIGHUP; restarting.");
262 close_listen_socks();
263 close_startup_pipes();
264 execv(saved_argv[0], saved_argv);
265 log("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0],
271 * Generic signal handler for terminating signals in the master daemon.
274 sigterm_handler(int sig)
276 received_sigterm = sig;
280 * SIGCHLD handler. This is called whenever a child dies. This will then
281 * reap any zombies left by exited children.
284 main_sigchld_handler(int sig)
286 int save_errno = errno;
290 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
291 (pid < 0 && errno == EINTR))
294 signal(SIGCHLD, main_sigchld_handler);
299 * Signal handler for the alarm after the login grace period has expired.
302 grace_alarm_handler(int sig)
304 /* XXX no idea how fix this signal handler */
306 /* Log error and exit. */
307 fatal("Timeout before authentication for %s", get_remote_ipaddr());
311 * Signal handler for the key regeneration alarm. Note that this
312 * alarm only occurs in the daemon waiting for connections, and it does not
313 * do anything with the private key or random state before forking.
314 * Thus there should be no concurrency control/asynchronous execution
318 generate_ephemeral_server_key(void)
323 verbose("Generating %s%d bit RSA key.",
324 sensitive_data.server_key ? "new " : "", options.server_key_bits);
325 if (sensitive_data.server_key != NULL)
326 key_free(sensitive_data.server_key);
327 sensitive_data.server_key = key_generate(KEY_RSA1,
328 options.server_key_bits);
329 verbose("RSA key generation complete.");
331 for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) {
334 sensitive_data.ssh1_cookie[i] = rnd & 0xff;
341 key_regeneration_alarm(int sig)
343 int save_errno = errno;
345 signal(SIGALRM, SIG_DFL);
351 sshd_exchange_identification(int sock_in, int sock_out)
354 int remote_major, remote_minor;
357 char buf[256]; /* Must not be larger than remote_version. */
358 char remote_version[256]; /* Must be at least as big as buf. */
360 if ((options.protocol & SSH_PROTO_1) &&
361 (options.protocol & SSH_PROTO_2)) {
362 major = PROTOCOL_MAJOR_1;
364 } else if (options.protocol & SSH_PROTO_2) {
365 major = PROTOCOL_MAJOR_2;
366 minor = PROTOCOL_MINOR_2;
368 major = PROTOCOL_MAJOR_1;
369 minor = PROTOCOL_MINOR_1;
371 snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", major, minor, SSH_VERSION);
372 server_version_string = xstrdup(buf);
374 if (client_version_string == NULL) {
375 /* Send our protocol version identification. */
376 if (atomicio(write, sock_out, server_version_string,
377 strlen(server_version_string))
378 != strlen(server_version_string)) {
379 log("Could not write ident string to %s", get_remote_ipaddr());
383 /* Read other sides version identification. */
384 memset(buf, 0, sizeof(buf));
385 for (i = 0; i < sizeof(buf) - 1; i++) {
386 if (atomicio(read, sock_in, &buf[i], 1) != 1) {
387 log("Did not receive identification string from %s",
388 get_remote_ipaddr());
391 if (buf[i] == '\r') {
393 /* Kludge for F-Secure Macintosh < 1.0.2 */
395 strncmp(buf, "SSH-1.5-W1.0", 12) == 0)
399 if (buf[i] == '\n') {
404 buf[sizeof(buf) - 1] = 0;
405 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(write, sock_out, s, strlen(s));
418 log("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 log("probed from %s with %s. Don't panic.",
429 get_remote_ipaddr(), client_version_string);
433 if (datafellows & SSH_BUG_SCANNER) {
434 log("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(write, sock_out, s, strlen(s));
479 log("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 (setgid(pw->pw_gid) < 0)
572 fatal("setgid failed for %u", pw->pw_gid );
573 if (setgroups(1, gidset) < 0)
574 fatal("setgroups: %.100s", strerror(errno));
575 permanently_set_uid(pw);
580 privsep_preauth(void)
582 Authctxt *authctxt = NULL;
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 fatal_remove_cleanup((void (*) (void *)) packet_close, NULL);
597 debug2("Network child is on pid %ld", (long)pid);
599 close(pmonitor->m_recvfd);
600 authctxt = monitor_child_preauth(pmonitor);
601 close(pmonitor->m_sendfd);
604 monitor_sync(pmonitor);
606 /* Wait for the child's exit status */
607 while (waitpid(pid, &status, 0) < 0)
611 /* Reinstall, since the child has finished */
612 fatal_add_cleanup((void (*) (void *)) packet_close, NULL);
618 close(pmonitor->m_sendfd);
620 /* Demote the child */
621 if (getuid() == 0 || geteuid() == 0)
622 privsep_preauth_child();
623 setproctitle("%s", "[net]");
629 privsep_postauth(Authctxt *authctxt)
631 extern Authctxt *x_authctxt;
633 /* XXX - Remote port forwarding */
634 x_authctxt = authctxt;
636 #ifdef DISABLE_FD_PASSING
639 if (authctxt->pw->pw_uid == 0 || options.use_login) {
641 /* File descriptor passing is broken or root login */
642 monitor_apply_keystate(pmonitor);
647 /* Authentication complete */
649 if (startup_pipe != -1) {
654 /* New socket pair */
655 monitor_reinit(pmonitor);
657 pmonitor->m_pid = fork();
658 if (pmonitor->m_pid == -1)
659 fatal("fork of unprivileged child failed");
660 else if (pmonitor->m_pid != 0) {
661 fatal_remove_cleanup((void (*) (void *)) packet_close, NULL);
663 debug2("User child is on pid %ld", (long)pmonitor->m_pid);
664 close(pmonitor->m_recvfd);
665 monitor_child_postauth(pmonitor);
671 close(pmonitor->m_sendfd);
673 /* Demote the private keys to public keys. */
674 demote_sensitive_data();
676 /* Drop privileges */
677 do_setusercontext(authctxt->pw);
679 /* It is safe now to apply the key state */
680 monitor_apply_keystate(pmonitor);
684 list_hostkey_types(void)
691 for (i = 0; i < options.num_host_key_files; i++) {
692 Key *key = sensitive_data.host_keys[i];
698 if (buffer_len(&b) > 0)
699 buffer_append(&b, ",", 1);
700 p = key_ssh_name(key);
701 buffer_append(&b, p, strlen(p));
705 buffer_append(&b, "\0", 1);
706 p = xstrdup(buffer_ptr(&b));
708 debug("list_hostkey_types: %s", p);
713 get_hostkey_by_type(int type)
717 for (i = 0; i < options.num_host_key_files; i++) {
718 Key *key = sensitive_data.host_keys[i];
719 if (key != NULL && key->type == type)
726 get_hostkey_by_index(int ind)
728 if (ind < 0 || ind >= options.num_host_key_files)
730 return (sensitive_data.host_keys[ind]);
734 get_hostkey_index(Key *key)
738 for (i = 0; i < options.num_host_key_files; i++) {
739 if (key == sensitive_data.host_keys[i])
746 * returns 1 if connection should be dropped, 0 otherwise.
747 * dropping starts at connection #max_startups_begin with a probability
748 * of (max_startups_rate/100). the probability increases linearly until
749 * all connections are dropped for startups > max_startups
752 drop_connection(int startups)
756 if (startups < options.max_startups_begin)
758 if (startups >= options.max_startups)
760 if (options.max_startups_rate == 100)
763 p = 100 - options.max_startups_rate;
764 p *= startups - options.max_startups_begin;
765 p /= (double) (options.max_startups - options.max_startups_begin);
766 p += options.max_startups_rate;
768 r = arc4random() / (double) UINT_MAX;
770 debug("drop_connection: p %g, r %g", p, r);
771 return (r < p) ? 1 : 0;
777 fprintf(stderr, "sshd version %s\n", SSH_VERSION);
778 fprintf(stderr, "Usage: %s [options]\n", __progname);
779 fprintf(stderr, "Options:\n");
780 fprintf(stderr, " -f file Configuration file (default %s)\n", _PATH_SERVER_CONFIG_FILE);
781 fprintf(stderr, " -d Debugging mode (multiple -d means more debugging)\n");
782 fprintf(stderr, " -i Started from inetd\n");
783 fprintf(stderr, " -D Do not fork into daemon mode\n");
784 fprintf(stderr, " -t Only test configuration file and keys\n");
785 fprintf(stderr, " -q Quiet (no logging)\n");
786 fprintf(stderr, " -p port Listen on the specified port (default: 22)\n");
787 fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n");
788 fprintf(stderr, " -g seconds Grace period for authentication (default: 600)\n");
789 fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n");
790 fprintf(stderr, " -h file File from which to read host key (default: %s)\n",
791 _PATH_HOST_KEY_FILE);
792 fprintf(stderr, " -u len Maximum hostname length for utmp recording\n");
793 fprintf(stderr, " -4 Use IPv4 only\n");
794 fprintf(stderr, " -6 Use IPv6 only\n");
795 fprintf(stderr, " -o option Process the option as if it was read from a configuration file.\n");
800 * Main program for the daemon.
803 main(int ac, char **av)
807 int opt, sock_in = 0, sock_out = 0, newsock, j, i, fdsetsz, on = 1;
811 struct sockaddr_storage from;
812 const char *remote_ip;
816 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
817 int listen_sock, maxfd;
822 int ret, key_used = 0;
824 #ifdef HAVE_SECUREWARE
825 (void)set_auth_parameters(ac, av);
827 __progname = get_progname(av[0]);
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:V:u:o:dDeiqtQ46")) != -1) {
847 config_file_name = optarg;
850 if (0 == debug_flag) {
852 options.log_level = SYSLOG_LEVEL_DEBUG1;
853 } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
856 fprintf(stderr, "Too high debugging level.\n");
873 options.log_level = SYSLOG_LEVEL_QUIET;
876 options.server_key_bits = atoi(optarg);
879 options.ports_from_cmdline = 1;
880 if (options.num_ports >= MAX_PORTS) {
881 fprintf(stderr, "too many ports.\n");
884 options.ports[options.num_ports++] = a2port(optarg);
885 if (options.ports[options.num_ports-1] == 0) {
886 fprintf(stderr, "Bad port number.\n");
891 if ((options.login_grace_time = convtime(optarg)) == -1) {
892 fprintf(stderr, "Invalid login grace time.\n");
897 if ((options.key_regeneration_time = convtime(optarg)) == -1) {
898 fprintf(stderr, "Invalid key regeneration interval.\n");
903 if (options.num_host_key_files >= MAX_HOSTKEYS) {
904 fprintf(stderr, "too many host keys.\n");
907 options.host_key_files[options.num_host_key_files++] = optarg;
910 client_version_string = optarg;
911 /* only makes sense with inetd_flag, i.e. no listen() */
918 utmp_len = atoi(optarg);
919 if (utmp_len > MAXHOSTNAMELEN) {
920 fprintf(stderr, "Invalid utmp length.\n");
925 if (process_server_config_line(&options, optarg,
926 "command-line", 0) != 0)
935 SSLeay_add_all_algorithms();
936 channel_set_af(IPv4or6);
939 * Force logging to stderr until we have loaded the private host
940 * key (unless started from inetd)
943 options.log_level == SYSLOG_LEVEL_NOT_SET ?
944 SYSLOG_LEVEL_INFO : options.log_level,
945 options.log_facility == SYSLOG_FACILITY_NOT_SET ?
946 SYSLOG_FACILITY_AUTH : options.log_facility,
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 log("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 log("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 log("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("Bad owner or mode for %s",
1062 _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, SOCK_STREAM, 0);
1149 if (listen_sock < 0) {
1150 /* kernel may not support ipv6 */
1151 verbose("socket: %.100s", strerror(errno));
1154 if (fcntl(listen_sock, F_SETFL, O_NONBLOCK) < 0) {
1155 error("listen_sock O_NONBLOCK: %s", strerror(errno));
1160 * Set socket options.
1161 * Allow local port reuse in TIME_WAIT.
1163 if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
1164 &on, sizeof(on)) == -1)
1165 error("setsockopt SO_REUSEADDR: %s", strerror(errno));
1167 debug("Bind to port %s on %s.", strport, ntop);
1169 /* Bind the socket to the desired port. */
1170 if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1172 error("Bind to port %s on %s failed: %.200s.",
1173 strport, ntop, strerror(errno));
1177 listen_socks[num_listen_socks] = listen_sock;
1180 /* Start listening on the port. */
1181 log("Server listening on %s port %s.", ntop, strport);
1182 if (listen(listen_sock, 5) < 0)
1183 fatal("listen: %.100s", strerror(errno));
1186 freeaddrinfo(options.listen_addrs);
1188 if (!num_listen_socks)
1189 fatal("Cannot bind any address.");
1191 if (options.protocol & SSH_PROTO_1)
1192 generate_ephemeral_server_key();
1195 * Arrange to restart on SIGHUP. The handler needs
1198 signal(SIGHUP, sighup_handler);
1200 signal(SIGTERM, sigterm_handler);
1201 signal(SIGQUIT, sigterm_handler);
1203 /* Arrange SIGCHLD to be caught. */
1204 signal(SIGCHLD, main_sigchld_handler);
1206 /* Write out the pid file after the sigterm handler is setup */
1209 * Record our pid in /var/run/sshd.pid to make it
1210 * easier to kill the correct sshd. We don't want to
1211 * do this before the bind above because the bind will
1212 * fail if there already is a daemon, and this will
1213 * overwrite any old pid in the file.
1215 f = fopen(options.pid_file, "wb");
1217 fprintf(f, "%ld\n", (long) getpid());
1222 /* setup fd set for listen */
1225 for (i = 0; i < num_listen_socks; i++)
1226 if (listen_socks[i] > maxfd)
1227 maxfd = listen_socks[i];
1228 /* pipes connected to unauthenticated childs */
1229 startup_pipes = xmalloc(options.max_startups * sizeof(int));
1230 for (i = 0; i < options.max_startups; i++)
1231 startup_pipes[i] = -1;
1234 * Stay listening for connections until the system crashes or
1235 * the daemon is killed with a signal.
1238 if (received_sighup)
1242 fdsetsz = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask);
1243 fdset = (fd_set *)xmalloc(fdsetsz);
1244 memset(fdset, 0, fdsetsz);
1246 for (i = 0; i < num_listen_socks; i++)
1247 FD_SET(listen_socks[i], fdset);
1248 for (i = 0; i < options.max_startups; i++)
1249 if (startup_pipes[i] != -1)
1250 FD_SET(startup_pipes[i], fdset);
1252 /* Wait in select until there is a connection. */
1253 ret = select(maxfd+1, fdset, NULL, NULL, NULL);
1254 if (ret < 0 && errno != EINTR)
1255 error("select: %.100s", strerror(errno));
1256 if (received_sigterm) {
1257 log("Received signal %d; terminating.",
1258 (int) received_sigterm);
1259 close_listen_socks();
1260 unlink(options.pid_file);
1263 if (key_used && key_do_regen) {
1264 generate_ephemeral_server_key();
1271 for (i = 0; i < options.max_startups; i++)
1272 if (startup_pipes[i] != -1 &&
1273 FD_ISSET(startup_pipes[i], fdset)) {
1275 * the read end of the pipe is ready
1276 * if the child has closed the pipe
1277 * after successful authentication
1278 * or if the child has died
1280 close(startup_pipes[i]);
1281 startup_pipes[i] = -1;
1284 for (i = 0; i < num_listen_socks; i++) {
1285 if (!FD_ISSET(listen_socks[i], fdset))
1287 fromlen = sizeof(from);
1288 newsock = accept(listen_socks[i], (struct sockaddr *)&from,
1291 if (errno != EINTR && errno != EWOULDBLOCK)
1292 error("accept: %.100s", strerror(errno));
1295 if (fcntl(newsock, F_SETFL, 0) < 0) {
1296 error("newsock del O_NONBLOCK: %s", strerror(errno));
1300 if (drop_connection(startups) == 1) {
1301 debug("drop connection #%d", startups);
1305 if (pipe(startup_p) == -1) {
1310 for (j = 0; j < options.max_startups; j++)
1311 if (startup_pipes[j] == -1) {
1312 startup_pipes[j] = startup_p[0];
1313 if (maxfd < startup_p[0])
1314 maxfd = startup_p[0];
1320 * Got connection. Fork a child to handle it, unless
1321 * we are in debugging mode.
1325 * In debugging mode. Close the listening
1326 * socket, and start processing the
1327 * connection without forking.
1329 debug("Server will not fork when running in debugging mode.");
1330 close_listen_socks();
1338 * Normal production daemon. Fork, and have
1339 * the child process the connection. The
1340 * parent continues listening.
1342 if ((pid = fork()) == 0) {
1344 * Child. Close the listening and max_startup
1345 * sockets. Start using the accepted socket.
1346 * Reinitialize logging (since our pid has
1347 * changed). We break out of the loop to handle
1350 startup_pipe = startup_p[1];
1351 close_startup_pipes();
1352 close_listen_socks();
1355 log_init(__progname, options.log_level, options.log_facility, log_stderr);
1360 /* Parent. Stay in the loop. */
1362 error("fork: %.100s", strerror(errno));
1364 debug("Forked child %ld.", (long)pid);
1366 close(startup_p[1]);
1368 /* Mark that the key has been used (it was "given" to the child). */
1369 if ((options.protocol & SSH_PROTO_1) &&
1371 /* Schedule server key regeneration alarm. */
1372 signal(SIGALRM, key_regeneration_alarm);
1373 alarm(options.key_regeneration_time);
1379 /* Close the new socket (the child is now taking care of it). */
1382 /* child process check (or debug mode) */
1383 if (num_listen_socks < 0)
1388 /* This is the child processing a new connection. */
1391 * Create a new session and process group since the 4.4BSD
1392 * setlogin() affects the entire process group. We don't
1393 * want the child to be able to affect the parent.
1396 /* XXX: this breaks Solaris */
1397 if (!debug_flag && !inetd_flag && setsid() < 0)
1398 error("setsid: %.100s", strerror(errno));
1402 * Disable the key regeneration alarm. We will not regenerate the
1403 * key since we are no longer in a position to give it to anyone. We
1404 * will not restart on SIGHUP since it no longer makes sense.
1407 signal(SIGALRM, SIG_DFL);
1408 signal(SIGHUP, SIG_DFL);
1409 signal(SIGTERM, SIG_DFL);
1410 signal(SIGQUIT, SIG_DFL);
1411 signal(SIGCHLD, SIG_DFL);
1412 signal(SIGINT, SIG_DFL);
1414 /* Set keepalives if requested. */
1415 if (options.keepalives &&
1416 setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on,
1418 error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1421 * Register our connection. This turns encryption off because we do
1424 packet_set_connection(sock_in, sock_out);
1426 remote_port = get_remote_port();
1427 remote_ip = get_remote_ipaddr();
1430 /* Check whether logins are denied from this host. */
1432 struct request_info req;
1434 request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0);
1437 if (!hosts_access(&req)) {
1438 debug("Connection refused by tcp wrapper");
1441 fatal("libwrap refuse returns");
1444 #endif /* LIBWRAP */
1446 /* Log the connection. */
1447 verbose("Connection from %.500s port %d", remote_ip, remote_port);
1450 * We don\'t want to listen forever unless the other side
1451 * successfully authenticates itself. So we set up an alarm which is
1452 * cleared after successful authentication. A limit of zero
1453 * indicates no limit. Note that we don\'t set the alarm in debugging
1454 * mode; it is just annoying to have the server exit just when you
1455 * are about to discover the bug.
1457 signal(SIGALRM, grace_alarm_handler);
1459 alarm(options.login_grace_time);
1461 sshd_exchange_identification(sock_in, sock_out);
1463 * Check that the connection comes from a privileged port.
1464 * Rhosts-Authentication only makes sense from privileged
1465 * programs. Of course, if the intruder has root access on his local
1466 * machine, he can connect from any port. So do not use these
1467 * authentication methods from machines that you do not trust.
1469 if (options.rhosts_authentication &&
1470 (remote_port >= IPPORT_RESERVED ||
1471 remote_port < IPPORT_RESERVED / 2)) {
1472 debug("Rhosts Authentication disabled, "
1473 "originating port %d not trusted.", remote_port);
1474 options.rhosts_authentication = 0;
1476 #if defined(KRB4) && !defined(KRB5)
1477 if (!packet_connection_is_ipv4() &&
1478 options.kerberos_authentication) {
1479 debug("Kerberos Authentication disabled, only available for IPv4.");
1480 options.kerberos_authentication = 0;
1482 #endif /* KRB4 && !KRB5 */
1484 /* If machine has AFS, set process authentication group. */
1491 packet_set_nonblocking();
1494 if ((authctxt = privsep_preauth()) != NULL)
1497 /* perform the key exchange */
1498 /* authenticate user and start session */
1501 authctxt = do_authentication2();
1504 authctxt = do_authentication();
1507 * If we use privilege separation, the unprivileged child transfers
1508 * the current keystate and exits
1511 mm_send_keystate(pmonitor);
1517 * In privilege separation, we fork another child and prepare
1518 * file descriptor passing.
1521 privsep_postauth(authctxt);
1522 /* the monitor process [priv] will not return */
1524 destroy_sensitive_data();
1527 /* Perform session preparation. */
1528 do_authenticated(authctxt);
1530 /* The connection has been terminated. */
1531 verbose("Closing connection to %.100s", remote_ip);
1535 #endif /* USE_PAM */
1546 * Decrypt session_key_int using our private server key and private host key
1547 * (key with larger modulus first).
1550 ssh1_session_key(BIGNUM *session_key_int)
1554 if (BN_cmp(sensitive_data.server_key->rsa->n, sensitive_data.ssh1_host_key->rsa->n) > 0) {
1555 /* Server key has bigger modulus. */
1556 if (BN_num_bits(sensitive_data.server_key->rsa->n) <
1557 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
1558 fatal("do_connection: %s: server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
1559 get_remote_ipaddr(),
1560 BN_num_bits(sensitive_data.server_key->rsa->n),
1561 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
1562 SSH_KEY_BITS_RESERVED);
1564 if (rsa_private_decrypt(session_key_int, session_key_int,
1565 sensitive_data.server_key->rsa) <= 0)
1567 if (rsa_private_decrypt(session_key_int, session_key_int,
1568 sensitive_data.ssh1_host_key->rsa) <= 0)
1571 /* Host key has bigger modulus (or they are equal). */
1572 if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) <
1573 BN_num_bits(sensitive_data.server_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
1574 fatal("do_connection: %s: host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d",
1575 get_remote_ipaddr(),
1576 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
1577 BN_num_bits(sensitive_data.server_key->rsa->n),
1578 SSH_KEY_BITS_RESERVED);
1580 if (rsa_private_decrypt(session_key_int, session_key_int,
1581 sensitive_data.ssh1_host_key->rsa) < 0)
1583 if (rsa_private_decrypt(session_key_int, session_key_int,
1584 sensitive_data.server_key->rsa) < 0)
1597 BIGNUM *session_key_int;
1598 u_char session_key[SSH_SESSION_KEY_LENGTH];
1600 u_int cipher_type, auth_mask, protocol_flags;
1604 * Generate check bytes that the client must send back in the user
1605 * packet in order for it to be accepted; this is used to defy ip
1606 * spoofing attacks. Note that this only works against somebody
1607 * doing IP spoofing from a remote machine; any machine on the local
1608 * network can still see outgoing packets and catch the random
1609 * cookie. This only affects rhosts authentication, and this is one
1610 * of the reasons why it is inherently insecure.
1612 for (i = 0; i < 8; i++) {
1615 cookie[i] = rnd & 0xff;
1620 * Send our public key. We include in the packet 64 bits of random
1621 * data that must be matched in the reply in order to prevent IP
1624 packet_start(SSH_SMSG_PUBLIC_KEY);
1625 for (i = 0; i < 8; i++)
1626 packet_put_char(cookie[i]);
1628 /* Store our public server RSA key. */
1629 packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n));
1630 packet_put_bignum(sensitive_data.server_key->rsa->e);
1631 packet_put_bignum(sensitive_data.server_key->rsa->n);
1633 /* Store our public host RSA key. */
1634 packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
1635 packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e);
1636 packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n);
1638 /* Put protocol flags. */
1639 packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN);
1641 /* Declare which ciphers we support. */
1642 packet_put_int(cipher_mask_ssh1(0));
1644 /* Declare supported authentication types. */
1646 if (options.rhosts_authentication)
1647 auth_mask |= 1 << SSH_AUTH_RHOSTS;
1648 if (options.rhosts_rsa_authentication)
1649 auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA;
1650 if (options.rsa_authentication)
1651 auth_mask |= 1 << SSH_AUTH_RSA;
1652 #if defined(KRB4) || defined(KRB5)
1653 if (options.kerberos_authentication)
1654 auth_mask |= 1 << SSH_AUTH_KERBEROS;
1656 #if defined(AFS) || defined(KRB5)
1657 if (options.kerberos_tgt_passing)
1658 auth_mask |= 1 << SSH_PASS_KERBEROS_TGT;
1661 if (options.afs_token_passing)
1662 auth_mask |= 1 << SSH_PASS_AFS_TOKEN;
1664 if (options.challenge_response_authentication == 1)
1665 auth_mask |= 1 << SSH_AUTH_TIS;
1666 if (options.password_authentication)
1667 auth_mask |= 1 << SSH_AUTH_PASSWORD;
1668 packet_put_int(auth_mask);
1670 /* Send the packet and wait for it to be sent. */
1672 packet_write_wait();
1674 debug("Sent %d bit server key and %d bit host key.",
1675 BN_num_bits(sensitive_data.server_key->rsa->n),
1676 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
1678 /* Read clients reply (cipher type and session key). */
1679 packet_read_expect(SSH_CMSG_SESSION_KEY);
1681 /* Get cipher type and check whether we accept this. */
1682 cipher_type = packet_get_char();
1684 if (!(cipher_mask_ssh1(0) & (1 << cipher_type)))
1685 packet_disconnect("Warning: client selects unsupported cipher.");
1687 /* Get check bytes from the packet. These must match those we
1688 sent earlier with the public key packet. */
1689 for (i = 0; i < 8; i++)
1690 if (cookie[i] != packet_get_char())
1691 packet_disconnect("IP Spoofing check bytes do not match.");
1693 debug("Encryption type: %.200s", cipher_name(cipher_type));
1695 /* Get the encrypted integer. */
1696 if ((session_key_int = BN_new()) == NULL)
1697 fatal("do_ssh1_kex: BN_new failed");
1698 packet_get_bignum(session_key_int);
1700 protocol_flags = packet_get_int();
1701 packet_set_protocol_flags(protocol_flags);
1704 /* Decrypt session_key_int using host/server keys */
1705 rsafail = PRIVSEP(ssh1_session_key(session_key_int));
1708 * Extract session key from the decrypted integer. The key is in the
1709 * least significant 256 bits of the integer; the first byte of the
1710 * key is in the highest bits.
1713 BN_mask_bits(session_key_int, sizeof(session_key) * 8);
1714 len = BN_num_bytes(session_key_int);
1715 if (len < 0 || len > sizeof(session_key)) {
1716 error("do_connection: bad session key len from %s: "
1717 "session_key_int %d > sizeof(session_key) %lu",
1718 get_remote_ipaddr(), len, (u_long)sizeof(session_key));
1721 memset(session_key, 0, sizeof(session_key));
1722 BN_bn2bin(session_key_int,
1723 session_key + sizeof(session_key) - len);
1725 compute_session_id(session_id, cookie,
1726 sensitive_data.ssh1_host_key->rsa->n,
1727 sensitive_data.server_key->rsa->n);
1729 * Xor the first 16 bytes of the session key with the
1732 for (i = 0; i < 16; i++)
1733 session_key[i] ^= session_id[i];
1737 int bytes = BN_num_bytes(session_key_int);
1738 u_char *buf = xmalloc(bytes);
1741 log("do_connection: generating a fake encryption key");
1742 BN_bn2bin(session_key_int, buf);
1744 MD5_Update(&md, buf, bytes);
1745 MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
1746 MD5_Final(session_key, &md);
1748 MD5_Update(&md, session_key, 16);
1749 MD5_Update(&md, buf, bytes);
1750 MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
1751 MD5_Final(session_key + 16, &md);
1752 memset(buf, 0, bytes);
1754 for (i = 0; i < 16; i++)
1755 session_id[i] = session_key[i] ^ session_key[i + 16];
1757 /* Destroy the private and public keys. No longer. */
1758 destroy_sensitive_data();
1761 mm_ssh1_session_id(session_id);
1763 /* Destroy the decrypted integer. It is no longer needed. */
1764 BN_clear_free(session_key_int);
1766 /* Set the session key. From this on all communications will be encrypted. */
1767 packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type);
1769 /* Destroy our copy of the session key. It is no longer needed. */
1770 memset(session_key, 0, sizeof(session_key));
1772 debug("Received session key; encryption turned on.");
1774 /* Send an acknowledgment packet. Note that this packet is sent encrypted. */
1775 packet_start(SSH_SMSG_SUCCESS);
1777 packet_write_wait();
1781 * SSH2 key exchange: diffie-hellman-group1-sha1
1788 if (options.ciphers != NULL) {
1789 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1790 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
1792 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1793 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
1794 myproposal[PROPOSAL_ENC_ALGS_STOC] =
1795 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
1797 if (options.macs != NULL) {
1798 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
1799 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
1801 if (!options.compression) {
1802 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
1803 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
1805 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types();
1807 /* start key exchange */
1808 kex = kex_setup(myproposal);
1810 kex->client_version_string=client_version_string;
1811 kex->server_version_string=server_version_string;
1812 kex->load_host_key=&get_hostkey_by_type;
1813 kex->host_key_index=&get_hostkey_index;
1817 dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
1819 session_id2 = kex->session_id;
1820 session_id2_len = kex->session_id_len;
1823 /* send 1st encrypted/maced/compressed message */
1824 packet_start(SSH2_MSG_IGNORE);
1825 packet_put_cstring("markus");
1827 packet_write_wait();