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:
19 * Copyright (c) 2000 Markus Friedl. All rights reserved.
21 * Redistribution and use in source and binary forms, with or without
22 * modification, are permitted provided that the following conditions
24 * 1. Redistributions of source code must retain the above copyright
25 * notice, this list of conditions and the following disclaimer.
26 * 2. Redistributions in binary form must reproduce the above copyright
27 * notice, this list of conditions and the following disclaimer in the
28 * documentation and/or other materials provided with the distribution.
30 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
31 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
33 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
34 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
35 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
36 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
37 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
38 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
39 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
43 RCSID("$OpenBSD: sshd.c,v 1.136 2000/12/05 16:47:28 todd Exp $");
57 #include <openssl/dh.h>
58 #include <openssl/bn.h>
59 #include <openssl/hmac.h>
61 #include <openssl/dsa.h>
62 #include <openssl/rsa.h>
67 #include "myproposal.h"
73 int allow_severity = LOG_INFO;
74 int deny_severity = LOG_WARNING;
81 #ifdef HAVE___PROGNAME
82 extern char *__progname;
87 /* Server configuration options. */
88 ServerOptions options;
90 /* Name of the server configuration file. */
91 char *config_file_name = SERVER_CONFIG_FILE;
94 * Flag indicating whether IPv4 or IPv6. This can be set on the command line.
95 * Default value is AF_UNSPEC means both IPv4 and IPv6.
98 int IPv4or6 = AF_INET;
100 int IPv4or6 = AF_UNSPEC;
104 * Debug mode flag. This can be set on the command line. If debug
105 * mode is enabled, extra debugging output will be sent to the system
106 * log, the daemon will not go to background, and will exit after processing
107 * the first connection.
111 /* Flag indicating that the daemon is being started from inetd. */
114 /* Flag indicating that sshd should not detach and become a daemon. */
115 int no_daemon_flag = 0;
117 /* debug goes to stderr unless inetd_flag is set */
120 /* argv[0] without path. */
123 /* Saved arguments to main(). */
128 * The sockets that the server is listening; this is used in the SIGHUP
131 #define MAX_LISTEN_SOCKS 16
132 int listen_socks[MAX_LISTEN_SOCKS];
133 int num_listen_socks = 0;
136 * the client's version string, passed by sshd2 in compat mode. if != NULL,
137 * sshd will skip the version-number exchange
139 char *client_version_string = NULL;
140 char *server_version_string = NULL;
143 * Any really sensitive data in the application is contained in this
144 * structure. The idea is that this structure could be locked into memory so
145 * that the pages do not get written into swap. However, there are some
146 * problems. The private key contains BIGNUMs, and we do not (in principle)
147 * have access to the internals of them, and locking just the structure is
148 * not very useful. Currently, memory locking is not implemented.
151 Key *server_key; /* empheral server key */
152 Key *ssh1_host_key; /* ssh1 host key */
153 Key **host_keys; /* all private host keys */
159 * Flag indicating whether the current session key has been used. This flag
160 * is set whenever the key is used, and cleared when the key is regenerated.
164 /* This is set to true when SIGHUP is received. */
165 int received_sighup = 0;
167 /* session identifier, used by RSA-auth */
168 unsigned char session_id[16];
171 unsigned char *session_id2 = NULL;
172 int session_id2_len = 0;
174 /* record remote hostname or ip */
175 unsigned int utmp_len = MAXHOSTNAMELEN;
177 /* Prototypes for various functions defined later in this file. */
181 void ssh_dh1_server(Kex *, Buffer *_kexinit, Buffer *);
182 void ssh_dhgex_server(Kex *, Buffer *_kexinit, Buffer *);
185 * Close all listening sockets
188 close_listen_socks(void)
191 for (i = 0; i < num_listen_socks; i++)
192 close(listen_socks[i]);
193 num_listen_socks = -1;
197 * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP;
198 * the effect is to reread the configuration file (and to regenerate
202 sighup_handler(int sig)
205 signal(SIGHUP, sighup_handler);
209 * Called from the main program after receiving SIGHUP.
210 * Restarts the server.
215 log("Received SIGHUP; restarting.");
216 close_listen_socks();
217 execv(saved_argv[0], saved_argv);
218 log("RESTART FAILED: av0='%s', error: %s.", av0, strerror(errno));
223 * Generic signal handler for terminating signals in the master daemon.
224 * These close the listen socket; not closing it seems to cause "Address
225 * already in use" problems on some machines, which is inconvenient.
228 sigterm_handler(int sig)
230 log("Received signal %d; terminating.", sig);
231 close_listen_socks();
232 unlink(options.pid_file);
237 * SIGCHLD handler. This is called whenever a child dies. This will then
238 * reap any zombies left by exited c.
241 main_sigchld_handler(int sig)
243 int save_errno = errno;
246 while (waitpid(-1, &status, WNOHANG) > 0)
249 signal(SIGCHLD, main_sigchld_handler);
254 * Signal handler for the alarm after the login grace period has expired.
257 grace_alarm_handler(int sig)
259 /* Close the connection. */
262 /* Log error and exit. */
263 fatal("Timeout before authentication for %s.", get_remote_ipaddr());
267 * Signal handler for the key regeneration alarm. Note that this
268 * alarm only occurs in the daemon waiting for connections, and it does not
269 * do anything with the private key or random state before forking.
270 * Thus there should be no concurrency control/asynchronous execution
273 /* XXX do we really want this work to be done in a signal handler ? -m */
275 generate_empheral_server_key(void)
277 log("Generating %s%d bit RSA key.", sensitive_data.server_key ? "new " : "",
278 options.server_key_bits);
279 if (sensitive_data.server_key != NULL)
280 key_free(sensitive_data.server_key);
281 sensitive_data.server_key = key_generate(KEY_RSA1, options.server_key_bits);
283 log("RSA key generation complete.");
286 key_regeneration_alarm(int sig)
288 int save_errno = errno;
290 /* Check if we should generate a new key. */
292 /* This should really be done in the background. */
293 generate_empheral_server_key();
296 /* Reschedule the alarm. */
297 signal(SIGALRM, key_regeneration_alarm);
298 alarm(options.key_regeneration_time);
303 sshd_exchange_identification(int sock_in, int sock_out)
306 int remote_major, remote_minor;
309 char buf[256]; /* Must not be larger than remote_version. */
310 char remote_version[256]; /* Must be at least as big as buf. */
312 if ((options.protocol & SSH_PROTO_1) &&
313 (options.protocol & SSH_PROTO_2)) {
314 major = PROTOCOL_MAJOR_1;
316 } else if (options.protocol & SSH_PROTO_2) {
317 major = PROTOCOL_MAJOR_2;
318 minor = PROTOCOL_MINOR_2;
320 major = PROTOCOL_MAJOR_1;
321 minor = PROTOCOL_MINOR_1;
323 snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", major, minor, SSH_VERSION);
324 server_version_string = xstrdup(buf);
326 if (client_version_string == NULL) {
327 /* Send our protocol version identification. */
328 if (atomicio(write, sock_out, server_version_string, strlen(server_version_string))
329 != strlen(server_version_string)) {
330 log("Could not write ident string to %s.", get_remote_ipaddr());
334 /* Read other side\'s version identification. */
335 for (i = 0; i < sizeof(buf) - 1; i++) {
336 if (atomicio(read, sock_in, &buf[i], 1) != 1) {
337 log("Did not receive ident string from %s.", get_remote_ipaddr());
340 if (buf[i] == '\r') {
343 /* Kludge for F-Secure Macintosh < 1.0.2 */
345 strncmp(buf, "SSH-1.5-W1.0", 12) == 0)
349 if (buf[i] == '\n') {
355 buf[sizeof(buf) - 1] = 0;
356 client_version_string = xstrdup(buf);
360 * Check that the versions match. In future this might accept
361 * several versions and set appropriate flags to handle them.
363 if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n",
364 &remote_major, &remote_minor, remote_version) != 3) {
365 s = "Protocol mismatch.\n";
366 (void) atomicio(write, sock_out, s, strlen(s));
369 log("Bad protocol version identification '%.100s' from %s",
370 client_version_string, get_remote_ipaddr());
373 debug("Client protocol version %d.%d; client software version %.100s",
374 remote_major, remote_minor, remote_version);
376 compat_datafellows(remote_version);
379 switch(remote_major) {
381 if (remote_minor == 99) {
382 if (options.protocol & SSH_PROTO_2)
388 if (!(options.protocol & SSH_PROTO_1)) {
392 if (remote_minor < 3) {
393 packet_disconnect("Your ssh version is too old and "
394 "is no longer supported. Please install a newer version.");
395 } else if (remote_minor == 3) {
396 /* note that this disables agent-forwarding */
401 if (options.protocol & SSH_PROTO_2) {
410 chop(server_version_string);
411 chop(client_version_string);
412 debug("Local version string %.200s", server_version_string);
415 s = "Protocol major versions differ.\n";
416 (void) atomicio(write, sock_out, s, strlen(s));
419 log("Protocol major versions differ for %s: %.200s vs. %.200s",
421 server_version_string, client_version_string);
425 packet_set_ssh2_format();
429 /* Destroy the host and server keys. They will no longer be needed. */
431 destroy_sensitive_data(void)
435 if (sensitive_data.server_key) {
436 key_free(sensitive_data.server_key);
437 sensitive_data.server_key = NULL;
439 for(i = 0; i < options.num_host_key_files; i++) {
440 if (sensitive_data.host_keys[i]) {
441 key_free(sensitive_data.host_keys[i]);
442 sensitive_data.host_keys[i] = NULL;
445 sensitive_data.ssh1_host_key = NULL;
448 load_private_key_autodetect(const char *filename)
452 Key *public, *private;
454 if (stat(filename, &st) < 0) {
459 * try to load the public key. right now this only works for RSA1,
460 * since SSH2 keys are fully encrypted
463 public = key_new(type);
464 if (!load_public_key(filename, public, NULL)) {
465 /* ok, so we will assume this is 'some' key */
470 /* Ok, try key with empty passphrase */
471 private = key_new(type);
472 if (load_private_key(filename, "", private, NULL)) {
473 debug("load_private_key_autodetect: type %d %s",
474 private->type, key_type(private));
482 list_hostkey_types(void)
484 static char buf[1024];
487 for(i = 0; i < options.num_host_key_files; i++) {
488 Key *key = sensitive_data.host_keys[i];
494 strlcat(buf, key_ssh_name(key), sizeof buf);
495 strlcat(buf, ",", sizeof buf);
500 if (i > 0 && buf[i-1] == ',')
502 debug("list_hostkey_types: %s", buf);
507 get_hostkey_by_type(int type)
510 for(i = 0; i < options.num_host_key_files; i++) {
511 Key *key = sensitive_data.host_keys[i];
512 if (key != NULL && key->type == type)
519 * returns 1 if connection should be dropped, 0 otherwise.
520 * dropping starts at connection #max_startups_begin with a probability
521 * of (max_startups_rate/100). the probability increases linearly until
522 * all connections are dropped for startups > max_startups
525 drop_connection(int startups)
529 if (startups < options.max_startups_begin)
531 if (startups >= options.max_startups)
533 if (options.max_startups_rate == 100)
536 p = 100 - options.max_startups_rate;
537 p *= startups - options.max_startups_begin;
538 p /= (double) (options.max_startups - options.max_startups_begin);
539 p += options.max_startups_rate;
541 r = arc4random() / (double) UINT_MAX;
543 debug("drop_connection: p %g, r %g", p, r);
544 return (r < p) ? 1 : 0;
547 int *startup_pipes = NULL; /* options.max_startup sized array of fd ints */
548 int startup_pipe; /* in child */
551 * Main program for the daemon.
554 main(int ac, char **av)
558 int opt, sock_in = 0, sock_out = 0, newsock, j, i, fdsetsz, on = 1;
563 struct sockaddr_storage from;
564 const char *remote_ip;
567 struct linger linger;
569 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
570 int listen_sock, maxfd;
574 __progname = get_progname(av[0]);
580 if (strchr(av[0], '/'))
581 av0 = strrchr(av[0], '/') + 1;
585 /* Initialize configuration options to their default values. */
586 initialize_server_options(&options);
588 /* Parse command-line arguments. */
589 while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:u:dDiqQ46")) != EOF) {
598 config_file_name = optarg;
601 if (0 == debug_flag) {
603 options.log_level = SYSLOG_LEVEL_DEBUG1;
604 } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
607 fprintf(stderr, "Too high debugging level.\n");
621 options.log_level = SYSLOG_LEVEL_QUIET;
624 options.server_key_bits = atoi(optarg);
627 options.ports_from_cmdline = 1;
628 if (options.num_ports >= MAX_PORTS) {
629 fprintf(stderr, "too many ports.\n");
632 options.ports[options.num_ports++] = atoi(optarg);
635 options.login_grace_time = atoi(optarg);
638 options.key_regeneration_time = atoi(optarg);
641 if (options.num_host_key_files >= MAX_HOSTKEYS) {
642 fprintf(stderr, "too many host keys.\n");
645 options.host_key_files[options.num_host_key_files++] = optarg;
648 client_version_string = optarg;
649 /* only makes sense with inetd_flag, i.e. no listen() */
653 utmp_len = atoi(optarg);
657 fprintf(stderr, "sshd version %s\n", SSH_VERSION);
658 fprintf(stderr, "Usage: %s [options]\n", av0);
659 fprintf(stderr, "Options:\n");
660 fprintf(stderr, " -f file Configuration file (default %s)\n", SERVER_CONFIG_FILE);
661 fprintf(stderr, " -d Debugging mode (multiple -d means more debugging)\n");
662 fprintf(stderr, " -i Started from inetd\n");
663 fprintf(stderr, " -q Quiet (no logging)\n");
664 fprintf(stderr, " -p port Listen on the specified port (default: 22)\n");
665 fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n");
666 fprintf(stderr, " -g seconds Grace period for authentication (default: 300)\n");
667 fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n");
668 fprintf(stderr, " -h file File from which to read host key (default: %s)\n",
670 fprintf(stderr, " -u len Maximum hostname length for utmp recording\n");
671 fprintf(stderr, " -4 Use IPv4 only\n");
672 fprintf(stderr, " -6 Use IPv6 only\n");
678 * Force logging to stderr until we have loaded the private host
679 * key (unless started from inetd)
682 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
683 options.log_facility == -1 ? SYSLOG_FACILITY_AUTH : options.log_facility,
684 !silent && !inetd_flag);
686 /* Read server configuration options from the configuration file. */
687 read_server_config(&options, config_file_name);
689 /* Fill in default values for those options not explicitly set. */
690 fill_default_server_options(&options);
692 /* Check that there are no remaining arguments. */
694 fprintf(stderr, "Extra argument %s.\n", av[optind]);
698 debug("sshd version %.100s", SSH_VERSION);
700 /* load private host keys */
701 sensitive_data.host_keys = xmalloc(options.num_host_key_files*sizeof(Key*));
702 sensitive_data.server_key = NULL;
703 sensitive_data.ssh1_host_key = NULL;
704 sensitive_data.have_ssh1_key = 0;
705 sensitive_data.have_ssh2_key = 0;
707 for(i = 0; i < options.num_host_key_files; i++) {
708 Key *key = load_private_key_autodetect(options.host_key_files[i]);
710 error("Could not load host key: %.200s: %.100s",
711 options.host_key_files[i], strerror(errno));
716 sensitive_data.ssh1_host_key = key;
717 sensitive_data.have_ssh1_key = 1;
721 sensitive_data.have_ssh2_key = 1;
724 sensitive_data.host_keys[i] = key;
726 if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) {
727 log("Disabling protocol version 1. Could not load host key");
728 options.protocol &= ~SSH_PROTO_1;
730 if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) {
731 log("Disabling protocol version 2. Could not load host key");
732 options.protocol &= ~SSH_PROTO_2;
734 if (! options.protocol & (SSH_PROTO_1|SSH_PROTO_2)) {
736 fprintf(stderr, "sshd: no hostkeys available -- exiting.\n");
737 log("sshd: no hostkeys available -- exiting.\n");
741 /* Check certain values for sanity. */
742 if (options.protocol & SSH_PROTO_1) {
743 if (options.server_key_bits < 512 ||
744 options.server_key_bits > 32768) {
745 fprintf(stderr, "Bad server key size.\n");
749 * Check that server and host key lengths differ sufficiently. This
750 * is necessary to make double encryption work with rsaref. Oh, I
751 * hate software patents. I dont know if this can go? Niels
753 if (options.server_key_bits >
754 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) - SSH_KEY_BITS_RESERVED &&
755 options.server_key_bits <
756 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
757 options.server_key_bits =
758 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED;
759 debug("Forcing server key to %d bits to make it differ from host key.",
760 options.server_key_bits);
764 #ifdef HAVE_SCO_PROTECTED_PW
765 (void) set_auth_parameters(ac, av);
768 /* Initialize the log (it is reinitialized below in case we forked). */
769 if (debug_flag && !inetd_flag)
771 log_init(av0, options.log_level, options.log_facility, log_stderr);
774 * If not in debugging mode, and not started from inetd, disconnect
775 * from the controlling terminal, and fork. The original process
778 if (!(debug_flag || inetd_flag || no_daemon_flag)) {
781 #endif /* TIOCNOTTY */
782 if (daemon(0, 0) < 0)
783 fatal("daemon() failed: %.200s", strerror(errno));
785 /* Disconnect from the controlling tty. */
787 fd = open("/dev/tty", O_RDWR | O_NOCTTY);
789 (void) ioctl(fd, TIOCNOTTY, NULL);
792 #endif /* TIOCNOTTY */
794 /* Reinitialize the log (because of the fork above). */
795 log_init(av0, options.log_level, options.log_facility, log_stderr);
797 /* Initialize the random number generator. */
800 /* Chdir to the root directory so that the current disk can be
801 unmounted if desired. */
804 /* Start listening for a socket, unless started from inetd. */
807 s1 = dup(0); /* Make sure descriptors 0, 1, and 2 are in use. */
813 * We intentionally do not close the descriptors 0, 1, and 2
814 * as our code for setting the descriptors won\'t work if
815 * ttyfd happens to be one of those.
817 debug("inetd sockets after dupping: %d, %d", sock_in, sock_out);
818 if (options.protocol & SSH_PROTO_1)
819 generate_empheral_server_key();
821 for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
822 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
824 if (num_listen_socks >= MAX_LISTEN_SOCKS)
825 fatal("Too many listen sockets. "
826 "Enlarge MAX_LISTEN_SOCKS");
827 if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
828 ntop, sizeof(ntop), strport, sizeof(strport),
829 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
830 error("getnameinfo failed");
833 /* Create socket for listening. */
834 listen_sock = socket(ai->ai_family, SOCK_STREAM, 0);
835 if (listen_sock < 0) {
836 /* kernel may not support ipv6 */
837 verbose("socket: %.100s", strerror(errno));
840 if (fcntl(listen_sock, F_SETFL, O_NONBLOCK) < 0) {
841 error("listen_sock O_NONBLOCK: %s", strerror(errno));
846 * Set socket options. We try to make the port
847 * reusable and have it close as fast as possible
848 * without waiting in unnecessary wait states on
851 setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
852 (void *) &on, sizeof(on));
855 setsockopt(listen_sock, SOL_SOCKET, SO_LINGER,
856 (void *) &linger, sizeof(linger));
858 debug("Bind to port %s on %s.", strport, ntop);
860 /* Bind the socket to the desired port. */
861 if ((bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) &&
863 error("Bind to port %s on %s failed: %.200s.",
864 strport, ntop, strerror(errno));
868 listen_socks[num_listen_socks] = listen_sock;
871 /* Start listening on the port. */
872 log("Server listening on %s port %s.", ntop, strport);
873 if (listen(listen_sock, 5) < 0)
874 fatal("listen: %.100s", strerror(errno));
877 freeaddrinfo(options.listen_addrs);
879 if (!num_listen_socks)
880 fatal("Cannot bind any address.");
884 * Record our pid in /var/run/sshd.pid to make it
885 * easier to kill the correct sshd. We don't want to
886 * do this before the bind above because the bind will
887 * fail if there already is a daemon, and this will
888 * overwrite any old pid in the file.
890 f = fopen(options.pid_file, "wb");
892 fprintf(f, "%u\n", (unsigned int) getpid());
896 if (options.protocol & SSH_PROTO_1) {
897 generate_empheral_server_key();
899 /* Schedule server key regeneration alarm. */
900 signal(SIGALRM, key_regeneration_alarm);
901 alarm(options.key_regeneration_time);
904 /* Arrange to restart on SIGHUP. The handler needs listen_sock. */
905 signal(SIGHUP, sighup_handler);
907 signal(SIGTERM, sigterm_handler);
908 signal(SIGQUIT, sigterm_handler);
910 /* Arrange SIGCHLD to be caught. */
911 signal(SIGCHLD, main_sigchld_handler);
913 /* setup fd set for listen */
916 for (i = 0; i < num_listen_socks; i++)
917 if (listen_socks[i] > maxfd)
918 maxfd = listen_socks[i];
919 /* pipes connected to unauthenticated childs */
920 startup_pipes = xmalloc(options.max_startups * sizeof(int));
921 for (i = 0; i < options.max_startups; i++)
922 startup_pipes[i] = -1;
925 * Stay listening for connections until the system crashes or
926 * the daemon is killed with a signal.
933 fdsetsz = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
934 fdset = (fd_set *)xmalloc(fdsetsz);
935 memset(fdset, 0, fdsetsz);
937 for (i = 0; i < num_listen_socks; i++)
938 FD_SET(listen_socks[i], fdset);
939 for (i = 0; i < options.max_startups; i++)
940 if (startup_pipes[i] != -1)
941 FD_SET(startup_pipes[i], fdset);
943 /* Wait in select until there is a connection. */
944 if (select(maxfd + 1, fdset, NULL, NULL, NULL) < 0) {
946 error("select: %.100s", strerror(errno));
949 for (i = 0; i < options.max_startups; i++)
950 if (startup_pipes[i] != -1 &&
951 FD_ISSET(startup_pipes[i], fdset)) {
953 * the read end of the pipe is ready
954 * if the child has closed the pipe
955 * after successfull authentication
956 * or if the child has died
958 close(startup_pipes[i]);
959 startup_pipes[i] = -1;
962 for (i = 0; i < num_listen_socks; i++) {
963 if (!FD_ISSET(listen_socks[i], fdset))
965 fromlen = sizeof(from);
966 newsock = accept(listen_socks[i], (struct sockaddr *)&from,
969 if (errno != EINTR && errno != EWOULDBLOCK)
970 error("accept: %.100s", strerror(errno));
973 if (fcntl(newsock, F_SETFL, 0) < 0) {
974 error("newsock del O_NONBLOCK: %s", strerror(errno));
977 if (drop_connection(startups) == 1) {
978 debug("drop connection #%d", startups);
982 if (pipe(startup_p) == -1) {
987 for (j = 0; j < options.max_startups; j++)
988 if (startup_pipes[j] == -1) {
989 startup_pipes[j] = startup_p[0];
990 if (maxfd < startup_p[0])
991 maxfd = startup_p[0];
997 * Got connection. Fork a child to handle it, unless
998 * we are in debugging mode.
1002 * In debugging mode. Close the listening
1003 * socket, and start processing the
1004 * connection without forking.
1006 debug("Server will not fork when running in debugging mode.");
1007 close_listen_socks();
1015 * Normal production daemon. Fork, and have
1016 * the child process the connection. The
1017 * parent continues listening.
1019 if ((pid = fork()) == 0) {
1021 * Child. Close the listening and max_startup
1022 * sockets. Start using the accepted socket.
1023 * Reinitialize logging (since our pid has
1024 * changed). We break out of the loop to handle
1027 startup_pipe = startup_p[1];
1028 for (j = 0; j < options.max_startups; j++)
1029 if (startup_pipes[j] != -1)
1030 close(startup_pipes[j]);
1031 close_listen_socks();
1034 log_init(av0, options.log_level, options.log_facility, log_stderr);
1039 /* Parent. Stay in the loop. */
1041 error("fork: %.100s", strerror(errno));
1043 debug("Forked child %d.", pid);
1045 close(startup_p[1]);
1047 /* Mark that the key has been used (it was "given" to the child). */
1052 /* Close the new socket (the child is now taking care of it). */
1055 /* child process check (or debug mode) */
1056 if (num_listen_socks < 0)
1061 /* This is the child processing a new connection. */
1064 * Disable the key regeneration alarm. We will not regenerate the
1065 * key since we are no longer in a position to give it to anyone. We
1066 * will not restart on SIGHUP since it no longer makes sense.
1069 signal(SIGALRM, SIG_DFL);
1070 signal(SIGHUP, SIG_DFL);
1071 signal(SIGTERM, SIG_DFL);
1072 signal(SIGQUIT, SIG_DFL);
1073 signal(SIGCHLD, SIG_DFL);
1074 signal(SIGINT, SIG_DFL);
1077 * Set socket options for the connection. We want the socket to
1078 * close as fast as possible without waiting for anything. If the
1079 * connection is not a socket, these will do nothing.
1081 /* setsockopt(sock_in, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); */
1083 linger.l_linger = 5;
1084 setsockopt(sock_in, SOL_SOCKET, SO_LINGER, (void *) &linger, sizeof(linger));
1087 * Register our connection. This turns encryption off because we do
1090 packet_set_connection(sock_in, sock_out);
1092 remote_port = get_remote_port();
1093 remote_ip = get_remote_ipaddr();
1095 /* Check whether logins are denied from this host. */
1097 /* XXX LIBWRAP noes not know about IPv6 */
1099 struct request_info req;
1101 request_init(&req, RQ_DAEMON, av0, RQ_FILE, sock_in, NULL);
1104 if (!hosts_access(&req)) {
1109 /*XXX IPv6 verbose("Connection from %.500s port %d", eval_client(&req), remote_port); */
1111 #endif /* LIBWRAP */
1112 /* Log the connection. */
1113 verbose("Connection from %.500s port %d", remote_ip, remote_port);
1116 * We don\'t want to listen forever unless the other side
1117 * successfully authenticates itself. So we set up an alarm which is
1118 * cleared after successful authentication. A limit of zero
1119 * indicates no limit. Note that we don\'t set the alarm in debugging
1120 * mode; it is just annoying to have the server exit just when you
1121 * are about to discover the bug.
1123 signal(SIGALRM, grace_alarm_handler);
1125 alarm(options.login_grace_time);
1127 sshd_exchange_identification(sock_in, sock_out);
1129 * Check that the connection comes from a privileged port. Rhosts-
1130 * and Rhosts-RSA-Authentication only make sense from priviledged
1131 * programs. Of course, if the intruder has root access on his local
1132 * machine, he can connect from any port. So do not use these
1133 * authentication methods from machines that you do not trust.
1135 if (remote_port >= IPPORT_RESERVED ||
1136 remote_port < IPPORT_RESERVED / 2) {
1137 debug("Rhosts Authentication methods disabled, "
1138 "originating port not trusted.");
1139 options.rhosts_authentication = 0;
1140 options.rhosts_rsa_authentication = 0;
1143 if (!packet_connection_is_ipv4() &&
1144 options.kerberos_authentication) {
1145 debug("Kerberos Authentication disabled, only available for IPv4.");
1146 options.kerberos_authentication = 0;
1150 packet_set_nonblocking();
1152 /* perform the key exchange */
1153 /* authenticate user and start session */
1156 do_authentication2();
1159 do_authentication();
1163 /* Cleanup user's ticket cache file. */
1164 if (options.kerberos_ticket_cleanup)
1168 /* The connection has been terminated. */
1169 verbose("Closing connection to %.100s", remote_ip);
1173 #endif /* USE_PAM */
1187 BIGNUM *session_key_int;
1188 unsigned char session_key[SSH_SESSION_KEY_LENGTH];
1189 unsigned char cookie[8];
1190 unsigned int cipher_type, auth_mask, protocol_flags;
1194 * Generate check bytes that the client must send back in the user
1195 * packet in order for it to be accepted; this is used to defy ip
1196 * spoofing attacks. Note that this only works against somebody
1197 * doing IP spoofing from a remote machine; any machine on the local
1198 * network can still see outgoing packets and catch the random
1199 * cookie. This only affects rhosts authentication, and this is one
1200 * of the reasons why it is inherently insecure.
1202 for (i = 0; i < 8; i++) {
1204 rand = arc4random();
1205 cookie[i] = rand & 0xff;
1210 * Send our public key. We include in the packet 64 bits of random
1211 * data that must be matched in the reply in order to prevent IP
1214 packet_start(SSH_SMSG_PUBLIC_KEY);
1215 for (i = 0; i < 8; i++)
1216 packet_put_char(cookie[i]);
1218 /* Store our public server RSA key. */
1219 packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n));
1220 packet_put_bignum(sensitive_data.server_key->rsa->e);
1221 packet_put_bignum(sensitive_data.server_key->rsa->n);
1223 /* Store our public host RSA key. */
1224 packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
1225 packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e);
1226 packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n);
1228 /* Put protocol flags. */
1229 packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN);
1231 /* Declare which ciphers we support. */
1232 packet_put_int(cipher_mask_ssh1(0));
1234 /* Declare supported authentication types. */
1236 if (options.rhosts_authentication)
1237 auth_mask |= 1 << SSH_AUTH_RHOSTS;
1238 if (options.rhosts_rsa_authentication)
1239 auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA;
1240 if (options.rsa_authentication)
1241 auth_mask |= 1 << SSH_AUTH_RSA;
1243 if (options.kerberos_authentication)
1244 auth_mask |= 1 << SSH_AUTH_KERBEROS;
1247 if (options.kerberos_tgt_passing)
1248 auth_mask |= 1 << SSH_PASS_KERBEROS_TGT;
1249 if (options.afs_token_passing)
1250 auth_mask |= 1 << SSH_PASS_AFS_TOKEN;
1253 if (options.skey_authentication == 1)
1254 auth_mask |= 1 << SSH_AUTH_TIS;
1256 if (options.password_authentication)
1257 auth_mask |= 1 << SSH_AUTH_PASSWORD;
1258 packet_put_int(auth_mask);
1260 /* Send the packet and wait for it to be sent. */
1262 packet_write_wait();
1264 debug("Sent %d bit server key and %d bit host key.",
1265 BN_num_bits(sensitive_data.server_key->rsa->n),
1266 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
1268 /* Read clients reply (cipher type and session key). */
1269 packet_read_expect(&plen, SSH_CMSG_SESSION_KEY);
1271 /* Get cipher type and check whether we accept this. */
1272 cipher_type = packet_get_char();
1274 if (!(cipher_mask_ssh1(0) & (1 << cipher_type)))
1275 packet_disconnect("Warning: client selects unsupported cipher.");
1277 /* Get check bytes from the packet. These must match those we
1278 sent earlier with the public key packet. */
1279 for (i = 0; i < 8; i++)
1280 if (cookie[i] != packet_get_char())
1281 packet_disconnect("IP Spoofing check bytes do not match.");
1283 debug("Encryption type: %.200s", cipher_name(cipher_type));
1285 /* Get the encrypted integer. */
1286 session_key_int = BN_new();
1287 packet_get_bignum(session_key_int, &slen);
1289 protocol_flags = packet_get_int();
1290 packet_set_protocol_flags(protocol_flags);
1292 packet_integrity_check(plen, 1 + 8 + slen + 4, SSH_CMSG_SESSION_KEY);
1295 * Decrypt it using our private server key and private host key (key
1296 * with larger modulus first).
1298 if (BN_cmp(sensitive_data.server_key->rsa->n, sensitive_data.ssh1_host_key->rsa->n) > 0) {
1299 /* Private key has bigger modulus. */
1300 if (BN_num_bits(sensitive_data.server_key->rsa->n) <
1301 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
1302 fatal("do_connection: %s: server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
1303 get_remote_ipaddr(),
1304 BN_num_bits(sensitive_data.server_key->rsa->n),
1305 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
1306 SSH_KEY_BITS_RESERVED);
1308 rsa_private_decrypt(session_key_int, session_key_int,
1309 sensitive_data.server_key->rsa);
1310 rsa_private_decrypt(session_key_int, session_key_int,
1311 sensitive_data.ssh1_host_key->rsa);
1313 /* Host key has bigger modulus (or they are equal). */
1314 if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) <
1315 BN_num_bits(sensitive_data.server_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
1316 fatal("do_connection: %s: host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d",
1317 get_remote_ipaddr(),
1318 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
1319 BN_num_bits(sensitive_data.server_key->rsa->n),
1320 SSH_KEY_BITS_RESERVED);
1322 rsa_private_decrypt(session_key_int, session_key_int,
1323 sensitive_data.ssh1_host_key->rsa);
1324 rsa_private_decrypt(session_key_int, session_key_int,
1325 sensitive_data.server_key->rsa);
1328 compute_session_id(session_id, cookie,
1329 sensitive_data.ssh1_host_key->rsa->n,
1330 sensitive_data.server_key->rsa->n);
1332 /* Destroy the private and public keys. They will no longer be needed. */
1333 destroy_sensitive_data();
1336 * Extract session key from the decrypted integer. The key is in the
1337 * least significant 256 bits of the integer; the first byte of the
1338 * key is in the highest bits.
1340 BN_mask_bits(session_key_int, sizeof(session_key) * 8);
1341 len = BN_num_bytes(session_key_int);
1342 if (len < 0 || len > sizeof(session_key))
1343 fatal("do_connection: bad len from %s: session_key_int %d > sizeof(session_key) %d",
1344 get_remote_ipaddr(),
1345 len, sizeof(session_key));
1346 memset(session_key, 0, sizeof(session_key));
1347 BN_bn2bin(session_key_int, session_key + sizeof(session_key) - len);
1349 /* Destroy the decrypted integer. It is no longer needed. */
1350 BN_clear_free(session_key_int);
1352 /* Xor the first 16 bytes of the session key with the session id. */
1353 for (i = 0; i < 16; i++)
1354 session_key[i] ^= session_id[i];
1356 /* Set the session key. From this on all communications will be encrypted. */
1357 packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type);
1359 /* Destroy our copy of the session key. It is no longer needed. */
1360 memset(session_key, 0, sizeof(session_key));
1362 debug("Received session key; encryption turned on.");
1364 /* Send an acknowledgement packet. Note that this packet is sent encrypted. */
1365 packet_start(SSH_SMSG_SUCCESS);
1367 packet_write_wait();
1371 * SSH2 key exchange: diffie-hellman-group1-sha1
1376 Buffer *server_kexinit;
1377 Buffer *client_kexinit;
1381 char *cprop[PROPOSAL_MAX];
1385 if (options.ciphers != NULL) {
1386 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1387 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
1389 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types();
1391 server_kexinit = kex_init(myproposal);
1392 client_kexinit = xmalloc(sizeof(*client_kexinit));
1393 buffer_init(client_kexinit);
1395 /* algorithm negotiation */
1396 kex_exchange_kexinit(server_kexinit, client_kexinit, cprop);
1397 kex = kex_choose_conf(cprop, myproposal, 1);
1398 for (i = 0; i < PROPOSAL_MAX; i++)
1401 switch (kex->kex_type) {
1403 ssh_dh1_server(kex, client_kexinit, server_kexinit);
1406 ssh_dhgex_server(kex, client_kexinit, server_kexinit);
1409 fatal("Unsupported key exchange %d", kex->kex_type);
1412 debug("send SSH2_MSG_NEWKEYS.");
1413 packet_start(SSH2_MSG_NEWKEYS);
1415 packet_write_wait();
1416 debug("done: send SSH2_MSG_NEWKEYS.");
1418 debug("Wait SSH2_MSG_NEWKEYS.");
1419 packet_read_expect(&payload_len, SSH2_MSG_NEWKEYS);
1420 debug("GOT SSH2_MSG_NEWKEYS.");
1423 /* send 1st encrypted/maced/compressed message */
1424 packet_start(SSH2_MSG_IGNORE);
1425 packet_put_cstring("markus");
1427 packet_write_wait();
1430 debug("done: KEX2.");
1437 /* diffie-hellman-group1-sha1 */
1440 ssh_dh1_server(Kex *kex, Buffer *client_kexinit, Buffer *server_kexinit)
1445 int payload_len, dlen;
1447 unsigned char *signature = NULL;
1448 unsigned char *server_host_key_blob = NULL;
1449 unsigned int sbloblen;
1450 unsigned int klen, kout;
1451 unsigned char *kbuf;
1452 unsigned char *hash;
1453 BIGNUM *shared_secret = 0;
1455 BIGNUM *dh_client_pub = 0;
1458 hostkey = get_hostkey_by_type(kex->hostkey_type);
1459 if (hostkey == NULL)
1460 fatal("Unsupported hostkey type %d", kex->hostkey_type);
1463 debug("Wait SSH2_MSG_KEXDH_INIT.");
1464 packet_read_expect(&payload_len, SSH2_MSG_KEXDH_INIT);
1467 dh_client_pub = BN_new();
1468 if (dh_client_pub == NULL)
1469 fatal("dh_client_pub == NULL");
1470 packet_get_bignum2(dh_client_pub, &dlen);
1473 fprintf(stderr, "\ndh_client_pub= ");
1474 BN_print_fp(stderr, dh_client_pub);
1475 fprintf(stderr, "\n");
1476 debug("bits %d", BN_num_bits(dh_client_pub));
1479 /* generate DH key */
1480 dh = dh_new_group1(); /* XXX depends on 'kex' */
1483 fprintf(stderr, "\np= ");
1484 BN_print_fp(stderr, dh->p);
1485 fprintf(stderr, "\ng= ");
1487 fprintf(stderr, "\npub= ");
1488 BN_print_fp(stderr, dh->pub_key);
1489 fprintf(stderr, "\n");
1490 DHparams_print_fp(stderr, dh);
1492 if (!dh_pub_is_valid(dh, dh_client_pub))
1493 packet_disconnect("bad client public DH value");
1496 kbuf = xmalloc(klen);
1497 kout = DH_compute_key(kbuf, dh_client_pub, dh);
1500 debug("shared secret: len %d/%d", klen, kout);
1501 fprintf(stderr, "shared secret == ");
1502 for (i = 0; i< kout; i++)
1503 fprintf(stderr, "%02x", (kbuf[i])&0xff);
1504 fprintf(stderr, "\n");
1506 shared_secret = BN_new();
1508 BN_bin2bn(kbuf, kout, shared_secret);
1509 memset(kbuf, 0, klen);
1512 /* XXX precompute? */
1513 key_to_blob(hostkey, &server_host_key_blob, &sbloblen);
1515 /* calc H */ /* XXX depends on 'kex' */
1517 client_version_string,
1518 server_version_string,
1519 buffer_ptr(client_kexinit), buffer_len(client_kexinit),
1520 buffer_ptr(server_kexinit), buffer_len(server_kexinit),
1521 (char *)server_host_key_blob, sbloblen,
1526 buffer_free(client_kexinit);
1527 buffer_free(server_kexinit);
1528 xfree(client_kexinit);
1529 xfree(server_kexinit);
1531 fprintf(stderr, "hash == ");
1532 for (i = 0; i< 20; i++)
1533 fprintf(stderr, "%02x", (hash[i])&0xff);
1534 fprintf(stderr, "\n");
1536 /* save session id := H */
1537 /* XXX hashlen depends on KEX */
1538 session_id2_len = 20;
1539 session_id2 = xmalloc(session_id2_len);
1540 memcpy(session_id2, hash, session_id2_len);
1543 /* XXX hashlen depends on KEX */
1544 key_sign(hostkey, &signature, &slen, hash, 20);
1546 destroy_sensitive_data();
1548 /* send server hostkey, DH pubkey 'f' and singed H */
1549 packet_start(SSH2_MSG_KEXDH_REPLY);
1550 packet_put_string((char *)server_host_key_blob, sbloblen);
1551 packet_put_bignum2(dh->pub_key); /* f */
1552 packet_put_string((char *)signature, slen);
1555 xfree(server_host_key_blob);
1556 packet_write_wait();
1558 kex_derive_keys(kex, hash, shared_secret);
1559 packet_set_kex(kex);
1561 /* have keys, free DH */
1565 /* diffie-hellman-group-exchange-sha1 */
1568 ssh_dhgex_server(Kex *kex, Buffer *client_kexinit, Buffer *server_kexinit)
1573 int payload_len, dlen;
1575 unsigned char *signature = NULL;
1576 unsigned char *server_host_key_blob = NULL;
1577 unsigned int sbloblen;
1578 unsigned int klen, kout;
1579 unsigned char *kbuf;
1580 unsigned char *hash;
1581 BIGNUM *shared_secret = 0;
1583 BIGNUM *dh_client_pub = 0;
1586 hostkey = get_hostkey_by_type(kex->hostkey_type);
1587 if (hostkey == NULL)
1588 fatal("Unsupported hostkey type %d", kex->hostkey_type);
1591 debug("Wait SSH2_MSG_KEX_DH_GEX_REQUEST.");
1592 packet_read_expect(&payload_len, SSH2_MSG_KEX_DH_GEX_REQUEST);
1593 nbits = packet_get_int();
1594 dh = choose_dh(nbits);
1596 debug("Sending SSH2_MSG_KEX_DH_GEX_GROUP.");
1597 packet_start(SSH2_MSG_KEX_DH_GEX_GROUP);
1598 packet_put_bignum2(dh->p);
1599 packet_put_bignum2(dh->g);
1601 packet_write_wait();
1603 debug("Wait SSH2_MSG_KEX_DH_GEX_INIT.");
1604 packet_read_expect(&payload_len, SSH2_MSG_KEX_DH_GEX_INIT);
1607 dh_client_pub = BN_new();
1608 if (dh_client_pub == NULL)
1609 fatal("dh_client_pub == NULL");
1610 packet_get_bignum2(dh_client_pub, &dlen);
1613 fprintf(stderr, "\ndh_client_pub= ");
1614 BN_print_fp(stderr, dh_client_pub);
1615 fprintf(stderr, "\n");
1616 debug("bits %d", BN_num_bits(dh_client_pub));
1620 fprintf(stderr, "\np= ");
1621 BN_print_fp(stderr, dh->p);
1622 fprintf(stderr, "\ng= ");
1624 fprintf(stderr, "\npub= ");
1625 BN_print_fp(stderr, dh->pub_key);
1626 fprintf(stderr, "\n");
1627 DHparams_print_fp(stderr, dh);
1629 if (!dh_pub_is_valid(dh, dh_client_pub))
1630 packet_disconnect("bad client public DH value");
1633 kbuf = xmalloc(klen);
1634 kout = DH_compute_key(kbuf, dh_client_pub, dh);
1637 debug("shared secret: len %d/%d", klen, kout);
1638 fprintf(stderr, "shared secret == ");
1639 for (i = 0; i< kout; i++)
1640 fprintf(stderr, "%02x", (kbuf[i])&0xff);
1641 fprintf(stderr, "\n");
1643 shared_secret = BN_new();
1645 BN_bin2bn(kbuf, kout, shared_secret);
1646 memset(kbuf, 0, klen);
1649 /* XXX precompute? */
1650 key_to_blob(hostkey, &server_host_key_blob, &sbloblen);
1652 /* calc H */ /* XXX depends on 'kex' */
1653 hash = kex_hash_gex(
1654 client_version_string,
1655 server_version_string,
1656 buffer_ptr(client_kexinit), buffer_len(client_kexinit),
1657 buffer_ptr(server_kexinit), buffer_len(server_kexinit),
1658 (char *)server_host_key_blob, sbloblen,
1659 nbits, dh->p, dh->g,
1664 buffer_free(client_kexinit);
1665 buffer_free(server_kexinit);
1666 xfree(client_kexinit);
1667 xfree(server_kexinit);
1669 fprintf(stderr, "hash == ");
1670 for (i = 0; i< 20; i++)
1671 fprintf(stderr, "%02x", (hash[i])&0xff);
1672 fprintf(stderr, "\n");
1674 /* save session id := H */
1675 /* XXX hashlen depends on KEX */
1676 session_id2_len = 20;
1677 session_id2 = xmalloc(session_id2_len);
1678 memcpy(session_id2, hash, session_id2_len);
1681 /* XXX hashlen depends on KEX */
1682 key_sign(hostkey, &signature, &slen, hash, 20);
1684 destroy_sensitive_data();
1686 /* send server hostkey, DH pubkey 'f' and singed H */
1687 packet_start(SSH2_MSG_KEX_DH_GEX_REPLY);
1688 packet_put_string((char *)server_host_key_blob, sbloblen);
1689 packet_put_bignum2(dh->pub_key); /* f */
1690 packet_put_string((char *)signature, slen);
1693 xfree(server_host_key_blob);
1694 packet_write_wait();
1696 kex_derive_keys(kex, hash, shared_secret);
1697 packet_set_kex(kex);
1699 /* have keys, free DH */