summaryrefslogtreecommitdiff
path: root/other/openssh-2.1.1p4/sshd.c
diff options
context:
space:
mode:
Diffstat (limited to 'other/openssh-2.1.1p4/sshd.c')
-rw-r--r--other/openssh-2.1.1p4/sshd.c1431
1 files changed, 0 insertions, 1431 deletions
diff --git a/other/openssh-2.1.1p4/sshd.c b/other/openssh-2.1.1p4/sshd.c
deleted file mode 100644
index f74a9e3..0000000
--- a/other/openssh-2.1.1p4/sshd.c
+++ /dev/null
@@ -1,1431 +0,0 @@
1/*
2 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 * All rights reserved
5 * Created: Fri Mar 17 17:09:28 1995 ylo
6 * This program is the ssh daemon. It listens for connections from clients, and
7 * performs authentication, executes use commands or shell, and forwards
8 * information to/from the application to the user client over an encrypted
9 * connection. This can also handle forwarding of X11, TCP/IP, and authentication
10 * agent connections.
11 *
12 * SSH2 implementation,
13 * Copyright (c) 2000 Markus Friedl. All rights reserved.
14 */
15
16#include "includes.h"
17RCSID("$OpenBSD: sshd.c,v 1.122 2000/07/11 08:11:34 deraadt Exp $");
18
19#include "xmalloc.h"
20#include "rsa.h"
21#include "ssh.h"
22#include "pty.h"
23#include "packet.h"
24#include "cipher.h"
25#include "mpaux.h"
26#include "servconf.h"
27#include "uidswap.h"
28#include "compat.h"
29#include "buffer.h"
30
31#include "ssh2.h"
32#include <openssl/dh.h>
33#include <openssl/bn.h>
34#include <openssl/hmac.h>
35#include "kex.h"
36#include <openssl/dsa.h>
37#include <openssl/rsa.h>
38
39#include "key.h"
40#include "dsa.h"
41
42#include "auth.h"
43#include "myproposal.h"
44#include "authfile.h"
45
46#ifdef LIBWRAP
47#include <tcpd.h>
48#include <syslog.h>
49int allow_severity = LOG_INFO;
50int deny_severity = LOG_WARNING;
51#endif /* LIBWRAP */
52
53#ifndef O_NOCTTY
54#define O_NOCTTY 0
55#endif
56
57/* Server configuration options. */
58ServerOptions options;
59
60/* Name of the server configuration file. */
61char *config_file_name = SERVER_CONFIG_FILE;
62
63/*
64 * Flag indicating whether IPv4 or IPv6. This can be set on the command line.
65 * Default value is AF_UNSPEC means both IPv4 and IPv6.
66 */
67#ifdef IPV4_DEFAULT
68int IPv4or6 = AF_INET;
69#else
70int IPv4or6 = AF_UNSPEC;
71#endif
72
73/*
74 * Debug mode flag. This can be set on the command line. If debug
75 * mode is enabled, extra debugging output will be sent to the system
76 * log, the daemon will not go to background, and will exit after processing
77 * the first connection.
78 */
79int debug_flag = 0;
80
81/* Flag indicating that the daemon is being started from inetd. */
82int inetd_flag = 0;
83
84/* debug goes to stderr unless inetd_flag is set */
85int log_stderr = 0;
86
87/* argv[0] without path. */
88char *av0;
89
90/* Saved arguments to main(). */
91char **saved_argv;
92int saved_argc;
93
94/*
95 * The sockets that the server is listening; this is used in the SIGHUP
96 * signal handler.
97 */
98#define MAX_LISTEN_SOCKS 16
99int listen_socks[MAX_LISTEN_SOCKS];
100int num_listen_socks = 0;
101
102/*
103 * the client's version string, passed by sshd2 in compat mode. if != NULL,
104 * sshd will skip the version-number exchange
105 */
106char *client_version_string = NULL;
107char *server_version_string = NULL;
108
109/*
110 * Any really sensitive data in the application is contained in this
111 * structure. The idea is that this structure could be locked into memory so
112 * that the pages do not get written into swap. However, there are some
113 * problems. The private key contains BIGNUMs, and we do not (in principle)
114 * have access to the internals of them, and locking just the structure is
115 * not very useful. Currently, memory locking is not implemented.
116 */
117struct {
118 RSA *private_key; /* Private part of empheral server key. */
119 RSA *host_key; /* Private part of host key. */
120 Key *dsa_host_key; /* Private DSA host key. */
121} sensitive_data;
122
123/*
124 * Flag indicating whether the current session key has been used. This flag
125 * is set whenever the key is used, and cleared when the key is regenerated.
126 */
127int key_used = 0;
128
129/* This is set to true when SIGHUP is received. */
130int received_sighup = 0;
131
132/* Public side of the server key. This value is regenerated regularly with
133 the private key. */
134RSA *public_key;
135
136/* session identifier, used by RSA-auth */
137unsigned char session_id[16];
138
139/* same for ssh2 */
140unsigned char *session_id2 = NULL;
141int session_id2_len = 0;
142
143/* Prototypes for various functions defined later in this file. */
144void do_ssh1_kex();
145void do_ssh2_kex();
146
147/*
148 * Close all listening sockets
149 */
150void
151close_listen_socks(void)
152{
153 int i;
154 for (i = 0; i < num_listen_socks; i++)
155 close(listen_socks[i]);
156 num_listen_socks = -1;
157}
158
159/*
160 * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP;
161 * the effect is to reread the configuration file (and to regenerate
162 * the server key).
163 */
164void
165sighup_handler(int sig)
166{
167 received_sighup = 1;
168 signal(SIGHUP, sighup_handler);
169}
170
171/*
172 * Called from the main program after receiving SIGHUP.
173 * Restarts the server.
174 */
175void
176sighup_restart()
177{
178 log("Received SIGHUP; restarting.");
179 close_listen_socks();
180 execv(saved_argv[0], saved_argv);
181 log("RESTART FAILED: av0='%s', error: %s.", av0, strerror(errno));
182 exit(1);
183}
184
185/*
186 * Generic signal handler for terminating signals in the master daemon.
187 * These close the listen socket; not closing it seems to cause "Address
188 * already in use" problems on some machines, which is inconvenient.
189 */
190void
191sigterm_handler(int sig)
192{
193 log("Received signal %d; terminating.", sig);
194 close_listen_socks();
195 unlink(options.pid_file);
196 exit(255);
197}
198
199/*
200 * SIGCHLD handler. This is called whenever a child dies. This will then
201 * reap any zombies left by exited c.
202 */
203void
204main_sigchld_handler(int sig)
205{
206 int save_errno = errno;
207 int status;
208
209 while (waitpid(-1, &status, WNOHANG) > 0)
210 ;
211
212 signal(SIGCHLD, main_sigchld_handler);
213 errno = save_errno;
214}
215
216/*
217 * Signal handler for the alarm after the login grace period has expired.
218 */
219void
220grace_alarm_handler(int sig)
221{
222 /* Close the connection. */
223 packet_close();
224
225 /* Log error and exit. */
226 fatal("Timeout before authentication for %s.", get_remote_ipaddr());
227}
228
229/*
230 * Signal handler for the key regeneration alarm. Note that this
231 * alarm only occurs in the daemon waiting for connections, and it does not
232 * do anything with the private key or random state before forking.
233 * Thus there should be no concurrency control/asynchronous execution
234 * problems.
235 */
236/* XXX do we really want this work to be done in a signal handler ? -m */
237void
238key_regeneration_alarm(int sig)
239{
240 int save_errno = errno;
241
242 /* Check if we should generate a new key. */
243 if (key_used) {
244 /* This should really be done in the background. */
245 log("Generating new %d bit RSA key.", options.server_key_bits);
246
247 if (sensitive_data.private_key != NULL)
248 RSA_free(sensitive_data.private_key);
249 sensitive_data.private_key = RSA_new();
250
251 if (public_key != NULL)
252 RSA_free(public_key);
253 public_key = RSA_new();
254
255 rsa_generate_key(sensitive_data.private_key, public_key,
256 options.server_key_bits);
257 arc4random_stir();
258 key_used = 0;
259 log("RSA key generation complete.");
260 }
261 /* Reschedule the alarm. */
262 signal(SIGALRM, key_regeneration_alarm);
263 alarm(options.key_regeneration_time);
264 errno = save_errno;
265}
266
267void
268sshd_exchange_identification(int sock_in, int sock_out)
269{
270 int i, mismatch;
271 int remote_major, remote_minor;
272 int major, minor;
273 char *s;
274 char buf[256]; /* Must not be larger than remote_version. */
275 char remote_version[256]; /* Must be at least as big as buf. */
276
277 if ((options.protocol & SSH_PROTO_1) &&
278 (options.protocol & SSH_PROTO_2)) {
279 major = PROTOCOL_MAJOR_1;
280 minor = 99;
281 } else if (options.protocol & SSH_PROTO_2) {
282 major = PROTOCOL_MAJOR_2;
283 minor = PROTOCOL_MINOR_2;
284 } else {
285 major = PROTOCOL_MAJOR_1;
286 minor = PROTOCOL_MINOR_1;
287 }
288 snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", major, minor, SSH_VERSION);
289 server_version_string = xstrdup(buf);
290
291 if (client_version_string == NULL) {
292 /* Send our protocol version identification. */
293 if (atomicio(write, sock_out, server_version_string, strlen(server_version_string))
294 != strlen(server_version_string)) {
295 log("Could not write ident string to %s.", get_remote_ipaddr());
296 fatal_cleanup();
297 }
298
299 /* Read other side\'s version identification. */
300 for (i = 0; i < sizeof(buf) - 1; i++) {
301 if (atomicio(read, sock_in, &buf[i], 1) != 1) {
302 log("Did not receive ident string from %s.", get_remote_ipaddr());
303 fatal_cleanup();
304 }
305 if (buf[i] == '\r') {
306 buf[i] = '\n';
307 buf[i + 1] = 0;
308 continue;
309 }
310 if (buf[i] == '\n') {
311 /* buf[i] == '\n' */
312 buf[i + 1] = 0;
313 break;
314 }
315 }
316 buf[sizeof(buf) - 1] = 0;
317 client_version_string = xstrdup(buf);
318 }
319
320 /*
321 * Check that the versions match. In future this might accept
322 * several versions and set appropriate flags to handle them.
323 */
324 if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n",
325 &remote_major, &remote_minor, remote_version) != 3) {
326 s = "Protocol mismatch.\n";
327 (void) atomicio(write, sock_out, s, strlen(s));
328 close(sock_in);
329 close(sock_out);
330 log("Bad protocol version identification '%.100s' from %s",
331 client_version_string, get_remote_ipaddr());
332 fatal_cleanup();
333 }
334 debug("Client protocol version %d.%d; client software version %.100s",
335 remote_major, remote_minor, remote_version);
336
337 compat_datafellows(remote_version);
338
339 mismatch = 0;
340 switch(remote_major) {
341 case 1:
342 if (remote_minor == 99) {
343 if (options.protocol & SSH_PROTO_2)
344 enable_compat20();
345 else
346 mismatch = 1;
347 break;
348 }
349 if (!(options.protocol & SSH_PROTO_1)) {
350 mismatch = 1;
351 break;
352 }
353 if (remote_minor < 3) {
354 packet_disconnect("Your ssh version is too old and "
355 "is no longer supported. Please install a newer version.");
356 } else if (remote_minor == 3) {
357 /* note that this disables agent-forwarding */
358 enable_compat13();
359 }
360 break;
361 case 2:
362 if (options.protocol & SSH_PROTO_2) {
363 enable_compat20();
364 break;
365 }
366 /* FALLTHROUGH */
367 default:
368 mismatch = 1;
369 break;
370 }
371 chop(server_version_string);
372 chop(client_version_string);
373 debug("Local version string %.200s", server_version_string);
374
375 if (mismatch) {
376 s = "Protocol major versions differ.\n";
377 (void) atomicio(write, sock_out, s, strlen(s));
378 close(sock_in);
379 close(sock_out);
380 log("Protocol major versions differ for %s: %.200s vs. %.200s",
381 get_remote_ipaddr(),
382 server_version_string, client_version_string);
383 fatal_cleanup();
384 }
385 if (compat20)
386 packet_set_ssh2_format();
387}
388
389
390void
391destroy_sensitive_data(void)
392{
393 /* Destroy the private and public keys. They will no longer be needed. */
394 if (public_key)
395 RSA_free(public_key);
396 if (sensitive_data.private_key)
397 RSA_free(sensitive_data.private_key);
398 if (sensitive_data.host_key)
399 RSA_free(sensitive_data.host_key);
400 if (sensitive_data.dsa_host_key != NULL)
401 key_free(sensitive_data.dsa_host_key);
402}
403
404int *startup_pipes = NULL; /* options.max_startup sized array of fd ints */
405int startup_pipe; /* in child */
406
407/*
408 * Main program for the daemon.
409 */
410int
411main(int ac, char **av)
412{
413 extern char *optarg;
414 extern int optind;
415 int opt, sock_in = 0, sock_out = 0, newsock, j, i, fdsetsz, on = 1;
416 pid_t pid;
417 socklen_t fromlen;
418 int silent = 0;
419 fd_set *fdset;
420 struct sockaddr_storage from;
421 const char *remote_ip;
422 int remote_port;
423 FILE *f;
424 struct linger linger;
425 struct addrinfo *ai;
426 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
427 int listen_sock, maxfd;
428 int startup_p[2];
429 int startups = 0, reverse_fun = 0;
430 char reverse_client[1024];
431
432 init_rng();
433
434 /* Save argv[0]. */
435 saved_argc = ac;
436 saved_argv = av;
437 if (strchr(av[0], '/'))
438 av0 = strrchr(av[0], '/') + 1;
439 else
440 av0 = av[0];
441
442 /* Initialize configuration options to their default values. */
443 initialize_server_options(&options);
444
445 /* Parse command-line arguments. */
446 while ((opt = getopt(ac, av, "r:f:p:b:k:h:g:V:diqQ46")) != EOF) {
447 switch (opt) {
448 case '4':
449 IPv4or6 = AF_INET;
450 break;
451 case '6':
452 IPv4or6 = AF_INET6;
453 break;
454 case 'f':
455 config_file_name = optarg;
456 break;
457 case 'd':
458 debug_flag = 1;
459 options.log_level = SYSLOG_LEVEL_DEBUG;
460 break;
461 case 'i':
462 inetd_flag = 1;
463 break;
464 case 'Q':
465 silent = 1;
466 break;
467 case 'q':
468 options.log_level = SYSLOG_LEVEL_QUIET;
469 break;
470 case 'b':
471 options.server_key_bits = atoi(optarg);
472 break;
473 case 'p':
474 options.ports_from_cmdline = 1;
475 if (options.num_ports >= MAX_PORTS)
476 fatal("too many ports.\n");
477 options.ports[options.num_ports++] = atoi(optarg);
478 break;
479 case 'g':
480 options.login_grace_time = atoi(optarg);
481 break;
482 case 'k':
483 options.key_regeneration_time = atoi(optarg);
484 break;
485 case 'h':
486 options.host_key_file = optarg;
487 break;
488 case 'V':
489 client_version_string = optarg;
490 /* only makes sense with inetd_flag, i.e. no listen() */
491 inetd_flag = 1;
492 break;
493 case 'r':
494 reverse_fun = 1;
495 strncpy(reverse_client, optarg, sizeof(reverse_client));
496 printf("Enabling reverse fun.\n");
497 break;
498 case '?':
499 default:
500 fprintf(stderr, "sshd version %s\n", SSH_VERSION);
501 fprintf(stderr, "Usage: %s [options]\n", av0);
502 fprintf(stderr, "Options:\n");
503 fprintf(stderr, " -f file Configuration file (default %s)\n", SERVER_CONFIG_FILE);
504 fprintf(stderr, " -d Debugging mode\n");
505 fprintf(stderr, " -i Started from inetd\n");
506 fprintf(stderr, " -q Quiet (no logging)\n");
507 fprintf(stderr, " -p port Listen on the specified port (default: 22)\n");
508 fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n");
509 fprintf(stderr, " -g seconds Grace period for authentication (default: 300)\n");
510 fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n");
511 fprintf(stderr, " -h file File from which to read host key (default: %s)\n",
512 HOST_KEY_FILE);
513 fprintf(stderr, " -4 Use IPv4 only\n");
514 fprintf(stderr, " -6 Use IPv6 only\n");
515 fprintf(stderr, " -r host Use Reverse-fun to connect to 'host'\n");
516 exit(1);
517 }
518 }
519
520 /*
521 * Force logging to stderr until we have loaded the private host
522 * key (unless started from inetd)
523 */
524 log_init(av0,
525 options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level,
526 options.log_facility == -1 ? SYSLOG_FACILITY_AUTH : options.log_facility,
527 !silent && !inetd_flag);
528
529 /* Read server configuration options from the configuration file. */
530 read_server_config(&options, config_file_name);
531
532 /* Fill in default values for those options not explicitly set. */
533 fill_default_server_options(&options);
534
535 /* Check that there are no remaining arguments. */
536 if (optind < ac) {
537 fprintf(stderr, "Extra argument %s.\n", av[optind]);
538 exit(1);
539 }
540
541 debug("sshd version %.100s", SSH_VERSION);
542
543 sensitive_data.dsa_host_key = NULL;
544 sensitive_data.host_key = NULL;
545
546 /* check if RSA support exists */
547 if ((options.protocol & SSH_PROTO_1) &&
548 rsa_alive() == 0) {
549 log("no RSA support in libssl and libcrypto. See ssl(8)");
550 log("Disabling protocol version 1");
551 options.protocol &= ~SSH_PROTO_1;
552 }
553 /* Load the RSA/DSA host key. It must have empty passphrase. */
554 if (options.protocol & SSH_PROTO_1) {
555 Key k;
556 sensitive_data.host_key = RSA_new();
557 k.type = KEY_RSA;
558 k.rsa = sensitive_data.host_key;
559 errno = 0;
560 if (!load_private_key(options.host_key_file, "", &k, NULL)) {
561 error("Could not load host key: %.200s: %.100s",
562 options.host_key_file, strerror(errno));
563 log("Disabling protocol version 1");
564 options.protocol &= ~SSH_PROTO_1;
565 }
566 k.rsa = NULL;
567 }
568 if (options.protocol & SSH_PROTO_2) {
569 sensitive_data.dsa_host_key = key_new(KEY_DSA);
570 if (!load_private_key(options.host_dsa_key_file, "", sensitive_data.dsa_host_key, NULL)) {
571
572 error("Could not load DSA host key: %.200s", options.host_dsa_key_file);
573 log("Disabling protocol version 2");
574 options.protocol &= ~SSH_PROTO_2;
575 }
576 }
577 if (! options.protocol & (SSH_PROTO_1|SSH_PROTO_2)) {
578 if (silent == 0)
579 fprintf(stderr, "sshd: no hostkeys available -- exiting.\n");
580 log("sshd: no hostkeys available -- exiting.\n");
581 exit(1);
582 }
583
584 /* Check certain values for sanity. */
585 if (options.protocol & SSH_PROTO_1) {
586 if (options.server_key_bits < 512 ||
587 options.server_key_bits > 32768) {
588 fprintf(stderr, "Bad server key size.\n");
589 exit(1);
590 }
591 /*
592 * Check that server and host key lengths differ sufficiently. This
593 * is necessary to make double encryption work with rsaref. Oh, I
594 * hate software patents. I dont know if this can go? Niels
595 */
596 if (options.server_key_bits >
597 BN_num_bits(sensitive_data.host_key->n) - SSH_KEY_BITS_RESERVED &&
598 options.server_key_bits <
599 BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED) {
600 options.server_key_bits =
601 BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED;
602 debug("Forcing server key to %d bits to make it differ from host key.",
603 options.server_key_bits);
604 }
605 }
606
607 /* Initialize the log (it is reinitialized below in case we forked). */
608 if (debug_flag && !inetd_flag)
609 log_stderr = 1;
610 log_init(av0, options.log_level, options.log_facility, log_stderr);
611
612 /*
613 * If not in debugging mode, and not started from inetd, disconnect
614 * from the controlling terminal, and fork. The original process
615 * exits.
616 */
617 if (!debug_flag && !inetd_flag) {
618#ifdef TIOCNOTTY
619 int fd;
620#endif /* TIOCNOTTY */
621 if (daemon(0, 0) < 0)
622 fatal("daemon() failed: %.200s", strerror(errno));
623
624 /* Disconnect from the controlling tty. */
625#ifdef TIOCNOTTY
626 fd = open("/dev/tty", O_RDWR | O_NOCTTY);
627 if (fd >= 0) {
628 (void) ioctl(fd, TIOCNOTTY, NULL);
629 close(fd);
630 }
631#endif /* TIOCNOTTY */
632 }
633 /* Reinitialize the log (because of the fork above). */
634 log_init(av0, options.log_level, options.log_facility, log_stderr);
635
636 /* Do not display messages to stdout in RSA code. */
637 rsa_set_verbose(0);
638
639 /* Initialize the random number generator. */
640 arc4random_stir();
641
642 /* Chdir to the root directory so that the current disk can be
643 unmounted if desired. */
644 chdir("/");
645
646 /* Start listening for a socket, unless started from inetd. */
647 if (inetd_flag) {
648 int s1, s2;
649 s1 = dup(0); /* Make sure descriptors 0, 1, and 2 are in use. */
650 s2 = dup(s1);
651 sock_in = dup(0);
652 sock_out = dup(1);
653 /*
654 * We intentionally do not close the descriptors 0, 1, and 2
655 * as our code for setting the descriptors won\'t work if
656 * ttyfd happens to be one of those.
657 */
658 debug("inetd sockets after dupping: %d, %d", sock_in, sock_out);
659
660 if (options.protocol & SSH_PROTO_1) {
661 public_key = RSA_new();
662 sensitive_data.private_key = RSA_new();
663 log("Generating %d bit RSA key.", options.server_key_bits);
664 rsa_generate_key(sensitive_data.private_key, public_key,
665 options.server_key_bits);
666 arc4random_stir();
667 log("RSA key generation complete.");
668 }
669 /* XXX: Have some reverse fun through firewalls. */
670 } else if (reverse_fun) {
671 int client_port = options.ports[0];
672 char port[100];
673 struct addrinfo *adi, hints;
674
675 memset(&hints, 0, sizeof(hints));
676 hints.ai_family = IPv4or6;
677 hints.ai_socktype = SOCK_STREAM;
678
679 memset(port, 0, sizeof(port));
680 snprintf(port, sizeof(port), "%d", client_port);
681 if (getaddrinfo(reverse_client, port, &hints, &adi) < 0) {
682 perror("addrinfo (during reverse fun)");
683 exit(errno);
684 }
685 if ((listen_sock = socket(adi->ai_family, SOCK_STREAM, 0)) < 0) {
686 perror("socket (during reverse fun)");
687 exit(errno);
688 }
689 printf("Reverse fun: Connecting to %s:%s\n", reverse_client, port);
690
691 if (connect(listen_sock, (struct sockaddr*)adi->ai_addr, sizeof(struct sockaddr)) < 0) {
692 perror("connect (during reverse fun)");
693 exit(errno);
694 }
695 if (fcntl(listen_sock, F_SETFL, 0) < 0)
696 error("newsock del O_NONBLOCK: %s", strerror(errno));
697
698 sock_in = listen_sock;
699 if ((sock_out = dup(sock_in)) < 0) {
700 perror("dup (during reverse fun)");
701 sock_out = sock_in;
702 }
703
704 if (options.protocol & SSH_PROTO_1) {
705 public_key = RSA_new();
706 sensitive_data.private_key = RSA_new();
707
708 log("Generating %d bit RSA key.", options.server_key_bits);
709 rsa_generate_key(sensitive_data.private_key, public_key,
710 options.server_key_bits);
711 arc4random_stir();
712 log("RSA key generation complete.");
713
714 /* Schedule server key regeneration alarm. */
715 signal(SIGALRM, key_regeneration_alarm);
716 alarm(options.key_regeneration_time);
717 }
718
719
720 } else {
721 for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
722 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
723 continue;
724 if (num_listen_socks >= MAX_LISTEN_SOCKS)
725 fatal("Too many listen sockets. "
726 "Enlarge MAX_LISTEN_SOCKS");
727 if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
728 ntop, sizeof(ntop), strport, sizeof(strport),
729 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
730 error("getnameinfo failed");
731 continue;
732 }
733 /* Create socket for listening. */
734 listen_sock = socket(ai->ai_family, SOCK_STREAM, 0);
735 if (listen_sock < 0) {
736 /* kernel may not support ipv6 */
737 verbose("socket: %.100s", strerror(errno));
738 continue;
739 }
740 if (fcntl(listen_sock, F_SETFL, O_NONBLOCK) < 0) {
741 error("listen_sock O_NONBLOCK: %s", strerror(errno));
742 close(listen_sock);
743 continue;
744 }
745 /*
746 * Set socket options. We try to make the port
747 * reusable and have it close as fast as possible
748 * without waiting in unnecessary wait states on
749 * close.
750 */
751 setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
752 (void *) &on, sizeof(on));
753 linger.l_onoff = 1;
754 linger.l_linger = 5;
755 setsockopt(listen_sock, SOL_SOCKET, SO_LINGER,
756 (void *) &linger, sizeof(linger));
757
758 debug("Bind to port %s on %s.", strport, ntop);
759
760 /* Bind the socket to the desired port. */
761 if ((bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) &&
762 (!ai->ai_next)) {
763 error("Bind to port %s on %s failed: %.200s.",
764 strport, ntop, strerror(errno));
765 close(listen_sock);
766 continue;
767 }
768 listen_socks[num_listen_socks] = listen_sock;
769 num_listen_socks++;
770
771 /* Start listening on the port. */
772 log("Server listening on %s port %s.", ntop, strport);
773 if (listen(listen_sock, 5) < 0)
774 fatal("listen: %.100s", strerror(errno));
775
776 }
777 freeaddrinfo(options.listen_addrs);
778
779 if (!num_listen_socks)
780 fatal("Cannot bind any address.");
781
782 if (!debug_flag) {
783 /*
784 * Record our pid in /etc/sshd_pid to make it easier
785 * to kill the correct sshd. We don\'t want to do
786 * this before the bind above because the bind will
787 * fail if there already is a daemon, and this will
788 * overwrite any old pid in the file.
789 */
790 f = fopen(options.pid_file, "w");
791 if (f) {
792 fprintf(f, "%u\n", (unsigned int) getpid());
793 fclose(f);
794 }
795 }
796 if (options.protocol & SSH_PROTO_1) {
797 public_key = RSA_new();
798 sensitive_data.private_key = RSA_new();
799
800 log("Generating %d bit RSA key.", options.server_key_bits);
801 rsa_generate_key(sensitive_data.private_key, public_key,
802 options.server_key_bits);
803 arc4random_stir();
804 log("RSA key generation complete.");
805
806 /* Schedule server key regeneration alarm. */
807 signal(SIGALRM, key_regeneration_alarm);
808 alarm(options.key_regeneration_time);
809 }
810
811 /* Arrange to restart on SIGHUP. The handler needs listen_sock. */
812 signal(SIGHUP, sighup_handler);
813
814 signal(SIGTERM, sigterm_handler);
815 signal(SIGQUIT, sigterm_handler);
816
817 /* Arrange SIGCHLD to be caught. */
818 signal(SIGCHLD, main_sigchld_handler);
819
820 /* setup fd set for listen */
821 fdset = NULL;
822 maxfd = 0;
823 for (i = 0; i < num_listen_socks; i++)
824 if (listen_socks[i] > maxfd)
825 maxfd = listen_socks[i];
826 /* pipes connected to unauthenticated childs */
827 startup_pipes = xmalloc(options.max_startups * sizeof(int));
828 for (i = 0; i < options.max_startups; i++)
829 startup_pipes[i] = -1;
830
831 /*
832 * Stay listening for connections until the system crashes or
833 * the daemon is killed with a signal.
834 */
835 for (;;) {
836 if (received_sighup)
837 sighup_restart();
838 if (fdset != NULL)
839 xfree(fdset);
840 fdsetsz = howmany(maxfd, NFDBITS) * sizeof(fd_mask);
841 fdset = (fd_set *)xmalloc(fdsetsz);
842 memset(fdset, 0, fdsetsz);
843
844 for (i = 0; i < num_listen_socks; i++)
845 FD_SET(listen_socks[i], fdset);
846 for (i = 0; i < options.max_startups; i++)
847 if (startup_pipes[i] != -1)
848 FD_SET(startup_pipes[i], fdset);
849
850 /* Wait in select until there is a connection. */
851 if (select(maxfd + 1, fdset, NULL, NULL, NULL) < 0) {
852 if (errno != EINTR)
853 error("select: %.100s", strerror(errno));
854 continue;
855 }
856 for (i = 0; i < options.max_startups; i++)
857 if (startup_pipes[i] != -1 &&
858 FD_ISSET(startup_pipes[i], fdset)) {
859 /*
860 * the read end of the pipe is ready
861 * if the child has closed the pipe
862 * after successfull authentication
863 * or if the child has died
864 */
865 close(startup_pipes[i]);
866 startup_pipes[i] = -1;
867 startups--;
868 }
869 for (i = 0; i < num_listen_socks; i++) {
870 if (!FD_ISSET(listen_socks[i], fdset))
871 continue;
872 fromlen = sizeof(from);
873 newsock = accept(listen_socks[i], (struct sockaddr *)&from,
874 &fromlen);
875 if (newsock < 0) {
876 if (errno != EINTR && errno != EWOULDBLOCK)
877 error("accept: %.100s", strerror(errno));
878 continue;
879 }
880 if (fcntl(newsock, F_SETFL, 0) < 0) {
881 error("newsock del O_NONBLOCK: %s", strerror(errno));
882 continue;
883 }
884 if (startups >= options.max_startups) {
885 close(newsock);
886 continue;
887 }
888 if (pipe(startup_p) == -1) {
889 close(newsock);
890 continue;
891 }
892
893 for (j = 0; j < options.max_startups; j++)
894 if (startup_pipes[j] == -1) {
895 startup_pipes[j] = startup_p[0];
896 if (maxfd < startup_p[0])
897 maxfd = startup_p[0];
898 startups++;
899 break;
900 }
901
902 /*
903 * Got connection. Fork a child to handle it, unless
904 * we are in debugging mode.
905 */
906 if (debug_flag) {
907 /*
908 * In debugging mode. Close the listening
909 * socket, and start processing the
910 * connection without forking.
911 */
912 debug("Server will not fork when running in debugging mode.");
913 close_listen_socks();
914 sock_in = newsock;
915 sock_out = newsock;
916 startup_pipe = -1;
917 pid = getpid();
918 break;
919 } else {
920 /*
921 * Normal production daemon. Fork, and have
922 * the child process the connection. The
923 * parent continues listening.
924 */
925 if ((pid = fork()) == 0) {
926 /*
927 * Child. Close the listening and max_startup
928 * sockets. Start using the accepted socket.
929 * Reinitialize logging (since our pid has
930 * changed). We break out of the loop to handle
931 * the connection.
932 */
933 startup_pipe = startup_p[1];
934 for (j = 0; j < options.max_startups; j++)
935 if (startup_pipes[j] != -1)
936 close(startup_pipes[j]);
937 close_listen_socks();
938 sock_in = newsock;
939 sock_out = newsock;
940 log_init(av0, options.log_level, options.log_facility, log_stderr);
941 break;
942 }
943 }
944
945 /* Parent. Stay in the loop. */
946 if (pid < 0)
947 error("fork: %.100s", strerror(errno));
948 else
949 debug("Forked child %d.", pid);
950
951 close(startup_p[1]);
952
953 /* Mark that the key has been used (it was "given" to the child). */
954 key_used = 1;
955
956 arc4random_stir();
957
958 /* Close the new socket (the child is now taking care of it). */
959 close(newsock);
960 }
961 /* child process check (or debug mode) */
962 if (num_listen_socks < 0)
963 break;
964 }
965 }
966
967 /* This is the child processing a new connection. */
968
969 /*
970 * Disable the key regeneration alarm. We will not regenerate the
971 * key since we are no longer in a position to give it to anyone. We
972 * will not restart on SIGHUP since it no longer makes sense.
973 */
974 alarm(0);
975 signal(SIGALRM, SIG_DFL);
976 signal(SIGHUP, SIG_DFL);
977 signal(SIGTERM, SIG_DFL);
978 signal(SIGQUIT, SIG_DFL);
979 signal(SIGCHLD, SIG_DFL);
980
981 /*
982 * Set socket options for the connection. We want the socket to
983 * close as fast as possible without waiting for anything. If the
984 * connection is not a socket, these will do nothing.
985 */
986 /* setsockopt(sock_in, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); */
987 linger.l_onoff = 1;
988 linger.l_linger = 5;
989 setsockopt(sock_in, SOL_SOCKET, SO_LINGER, (void *) &linger, sizeof(linger));
990
991 /*
992 * Register our connection. This turns encryption off because we do
993 * not have a key.
994 */
995 packet_set_connection(sock_in, sock_out);
996
997 remote_port = get_remote_port();
998 remote_ip = get_remote_ipaddr();
999
1000 /* Check whether logins are denied from this host. */
1001#ifdef LIBWRAP
1002 /* XXX LIBWRAP noes not know about IPv6 */
1003 {
1004 struct request_info req;
1005
1006 request_init(&req, RQ_DAEMON, av0, RQ_FILE, sock_in, NULL);
1007 fromhost(&req);
1008
1009 if (!hosts_access(&req)) {
1010 close(sock_in);
1011 close(sock_out);
1012 refuse(&req);
1013 }
1014/*XXX IPv6 verbose("Connection from %.500s port %d", eval_client(&req), remote_port); */
1015 }
1016#endif /* LIBWRAP */
1017 /* Log the connection. */
1018 verbose("Connection from %.500s port %d", remote_ip, remote_port);
1019
1020 /*
1021 * We don\'t want to listen forever unless the other side
1022 * successfully authenticates itself. So we set up an alarm which is
1023 * cleared after successful authentication. A limit of zero
1024 * indicates no limit. Note that we don\'t set the alarm in debugging
1025 * mode; it is just annoying to have the server exit just when you
1026 * are about to discover the bug.
1027 */
1028 signal(SIGALRM, grace_alarm_handler);
1029 if (!debug_flag)
1030 alarm(options.login_grace_time);
1031
1032 sshd_exchange_identification(sock_in, sock_out);
1033 /*
1034 * Check that the connection comes from a privileged port. Rhosts-
1035 * and Rhosts-RSA-Authentication only make sense from priviledged
1036 * programs. Of course, if the intruder has root access on his local
1037 * machine, he can connect from any port. So do not use these
1038 * authentication methods from machines that you do not trust.
1039 */
1040 if (remote_port >= IPPORT_RESERVED ||
1041 remote_port < IPPORT_RESERVED / 2) {
1042 options.rhosts_authentication = 0;
1043 options.rhosts_rsa_authentication = 0;
1044 }
1045#ifdef KRB4
1046 if (!packet_connection_is_ipv4() &&
1047 options.kerberos_authentication) {
1048 debug("Kerberos Authentication disabled, only available for IPv4.");
1049 options.kerberos_authentication = 0;
1050 }
1051#endif /* KRB4 */
1052
1053 packet_set_nonblocking();
1054
1055 /* perform the key exchange */
1056 /* authenticate user and start session */
1057 if (compat20) {
1058 do_ssh2_kex();
1059 do_authentication2();
1060 } else {
1061 do_ssh1_kex();
1062 do_authentication();
1063 }
1064
1065#ifdef KRB4
1066 /* Cleanup user's ticket cache file. */
1067 if (options.kerberos_ticket_cleanup)
1068 (void) dest_tkt();
1069#endif /* KRB4 */
1070
1071 /* The connection has been terminated. */
1072 verbose("Closing connection to %.100s", remote_ip);
1073
1074#ifdef USE_PAM
1075 finish_pam();
1076#endif /* USE_PAM */
1077
1078 packet_close();
1079 exit(0);
1080}
1081
1082/*
1083 * SSH1 key exchange
1084 */
1085void
1086do_ssh1_kex()
1087{
1088 int i, len;
1089 int plen, slen;
1090 BIGNUM *session_key_int;
1091 unsigned char session_key[SSH_SESSION_KEY_LENGTH];
1092 unsigned char cookie[8];
1093 unsigned int cipher_type, auth_mask, protocol_flags;
1094 u_int32_t rand = 0;
1095
1096 /*
1097 * Generate check bytes that the client must send back in the user
1098 * packet in order for it to be accepted; this is used to defy ip
1099 * spoofing attacks. Note that this only works against somebody
1100 * doing IP spoofing from a remote machine; any machine on the local
1101 * network can still see outgoing packets and catch the random
1102 * cookie. This only affects rhosts authentication, and this is one
1103 * of the reasons why it is inherently insecure.
1104 */
1105 for (i = 0; i < 8; i++) {
1106 if (i % 4 == 0)
1107 rand = arc4random();
1108 cookie[i] = rand & 0xff;
1109 rand >>= 8;
1110 }
1111
1112 /*
1113 * Send our public key. We include in the packet 64 bits of random
1114 * data that must be matched in the reply in order to prevent IP
1115 * spoofing.
1116 */
1117 packet_start(SSH_SMSG_PUBLIC_KEY);
1118 for (i = 0; i < 8; i++)
1119 packet_put_char(cookie[i]);
1120
1121 /* Store our public server RSA key. */
1122 packet_put_int(BN_num_bits(public_key->n));
1123 packet_put_bignum(public_key->e);
1124 packet_put_bignum(public_key->n);
1125
1126 /* Store our public host RSA key. */
1127 packet_put_int(BN_num_bits(sensitive_data.host_key->n));
1128 packet_put_bignum(sensitive_data.host_key->e);
1129 packet_put_bignum(sensitive_data.host_key->n);
1130
1131 /* Put protocol flags. */
1132 packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN);
1133
1134 /* Declare which ciphers we support. */
1135 packet_put_int(cipher_mask1());
1136
1137 /* Declare supported authentication types. */
1138 auth_mask = 0;
1139 if (options.rhosts_authentication)
1140 auth_mask |= 1 << SSH_AUTH_RHOSTS;
1141 if (options.rhosts_rsa_authentication)
1142 auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA;
1143 if (options.rsa_authentication)
1144 auth_mask |= 1 << SSH_AUTH_RSA;
1145#ifdef KRB4
1146 if (options.kerberos_authentication)
1147 auth_mask |= 1 << SSH_AUTH_KERBEROS;
1148#endif
1149#ifdef AFS
1150 if (options.kerberos_tgt_passing)
1151 auth_mask |= 1 << SSH_PASS_KERBEROS_TGT;
1152 if (options.afs_token_passing)
1153 auth_mask |= 1 << SSH_PASS_AFS_TOKEN;
1154#endif
1155#ifdef SKEY
1156 if (options.skey_authentication == 1)
1157 auth_mask |= 1 << SSH_AUTH_TIS;
1158#endif
1159 if (options.password_authentication)
1160 auth_mask |= 1 << SSH_AUTH_PASSWORD;
1161 packet_put_int(auth_mask);
1162
1163 /* Send the packet and wait for it to be sent. */
1164 packet_send();
1165 packet_write_wait();
1166
1167 debug("Sent %d bit public key and %d bit host key.",
1168 BN_num_bits(public_key->n), BN_num_bits(sensitive_data.host_key->n));
1169
1170 /* Read clients reply (cipher type and session key). */
1171 packet_read_expect(&plen, SSH_CMSG_SESSION_KEY);
1172
1173 /* Get cipher type and check whether we accept this. */
1174 cipher_type = packet_get_char();
1175
1176 if (!(cipher_mask() & (1 << cipher_type)))
1177 packet_disconnect("Warning: client selects unsupported cipher.");
1178
1179 /* Get check bytes from the packet. These must match those we
1180 sent earlier with the public key packet. */
1181 for (i = 0; i < 8; i++)
1182 if (cookie[i] != packet_get_char())
1183 packet_disconnect("IP Spoofing check bytes do not match.");
1184
1185 debug("Encryption type: %.200s", cipher_name(cipher_type));
1186
1187 /* Get the encrypted integer. */
1188 session_key_int = BN_new();
1189 packet_get_bignum(session_key_int, &slen);
1190
1191 protocol_flags = packet_get_int();
1192 packet_set_protocol_flags(protocol_flags);
1193
1194 packet_integrity_check(plen, 1 + 8 + slen + 4, SSH_CMSG_SESSION_KEY);
1195
1196 /*
1197 * Decrypt it using our private server key and private host key (key
1198 * with larger modulus first).
1199 */
1200 if (BN_cmp(sensitive_data.private_key->n, sensitive_data.host_key->n) > 0) {
1201 /* Private key has bigger modulus. */
1202 if (BN_num_bits(sensitive_data.private_key->n) <
1203 BN_num_bits(sensitive_data.host_key->n) + SSH_KEY_BITS_RESERVED) {
1204 fatal("do_connection: %s: private_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
1205 get_remote_ipaddr(),
1206 BN_num_bits(sensitive_data.private_key->n),
1207 BN_num_bits(sensitive_data.host_key->n),
1208 SSH_KEY_BITS_RESERVED);
1209 }
1210 rsa_private_decrypt(session_key_int, session_key_int,
1211 sensitive_data.private_key);
1212 rsa_private_decrypt(session_key_int, session_key_int,
1213 sensitive_data.host_key);
1214 } else {
1215 /* Host key has bigger modulus (or they are equal). */
1216 if (BN_num_bits(sensitive_data.host_key->n) <
1217 BN_num_bits(sensitive_data.private_key->n) + SSH_KEY_BITS_RESERVED) {
1218 fatal("do_connection: %s: host_key %d < private_key %d + SSH_KEY_BITS_RESERVED %d",
1219 get_remote_ipaddr(),
1220 BN_num_bits(sensitive_data.host_key->n),
1221 BN_num_bits(sensitive_data.private_key->n),
1222 SSH_KEY_BITS_RESERVED);
1223 }
1224 rsa_private_decrypt(session_key_int, session_key_int,
1225 sensitive_data.host_key);
1226 rsa_private_decrypt(session_key_int, session_key_int,
1227 sensitive_data.private_key);
1228 }
1229
1230 compute_session_id(session_id, cookie,
1231 sensitive_data.host_key->n,
1232 sensitive_data.private_key->n);
1233
1234 /* Destroy the private and public keys. They will no longer be needed. */
1235 destroy_sensitive_data();
1236
1237 /*
1238 * Extract session key from the decrypted integer. The key is in the
1239 * least significant 256 bits of the integer; the first byte of the
1240 * key is in the highest bits.
1241 */
1242 BN_mask_bits(session_key_int, sizeof(session_key) * 8);
1243 len = BN_num_bytes(session_key_int);
1244 if (len < 0 || len > sizeof(session_key))
1245 fatal("do_connection: bad len from %s: session_key_int %d > sizeof(session_key) %d",
1246 get_remote_ipaddr(),
1247 len, sizeof(session_key));
1248 memset(session_key, 0, sizeof(session_key));
1249 BN_bn2bin(session_key_int, session_key + sizeof(session_key) - len);
1250
1251 /* Destroy the decrypted integer. It is no longer needed. */
1252 BN_clear_free(session_key_int);
1253
1254 /* Xor the first 16 bytes of the session key with the session id. */
1255 for (i = 0; i < 16; i++)
1256 session_key[i] ^= session_id[i];
1257
1258 /* Set the session key. From this on all communications will be encrypted. */
1259 packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type);
1260
1261 /* Destroy our copy of the session key. It is no longer needed. */
1262 memset(session_key, 0, sizeof(session_key));
1263
1264 debug("Received session key; encryption turned on.");
1265
1266 /* Send an acknowledgement packet. Note that this packet is sent encrypted. */
1267 packet_start(SSH_SMSG_SUCCESS);
1268 packet_send();
1269 packet_write_wait();
1270}
1271
1272/*
1273 * SSH2 key exchange: diffie-hellman-group1-sha1
1274 */
1275void
1276do_ssh2_kex()
1277{
1278 Buffer *server_kexinit;
1279 Buffer *client_kexinit;
1280 int payload_len, dlen;
1281 int slen;
1282 unsigned int klen, kout;
1283 unsigned char *signature = NULL;
1284 unsigned char *server_host_key_blob = NULL;
1285 unsigned int sbloblen;
1286 DH *dh;
1287 BIGNUM *dh_client_pub = 0;
1288 BIGNUM *shared_secret = 0;
1289 int i;
1290 unsigned char *kbuf;
1291 unsigned char *hash;
1292 Kex *kex;
1293 char *cprop[PROPOSAL_MAX];
1294
1295/* KEXINIT */
1296
1297 if (options.ciphers != NULL) {
1298 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1299 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
1300 }
1301 server_kexinit = kex_init(myproposal);
1302 client_kexinit = xmalloc(sizeof(*client_kexinit));
1303 buffer_init(client_kexinit);
1304
1305 /* algorithm negotiation */
1306 kex_exchange_kexinit(server_kexinit, client_kexinit, cprop);
1307 kex = kex_choose_conf(cprop, myproposal, 1);
1308 for (i = 0; i < PROPOSAL_MAX; i++)
1309 xfree(cprop[i]);
1310
1311/* KEXDH */
1312
1313 debug("Wait SSH2_MSG_KEXDH_INIT.");
1314 packet_read_expect(&payload_len, SSH2_MSG_KEXDH_INIT);
1315
1316 /* key, cert */
1317 dh_client_pub = BN_new();
1318 if (dh_client_pub == NULL)
1319 fatal("dh_client_pub == NULL");
1320 packet_get_bignum2(dh_client_pub, &dlen);
1321
1322#ifdef DEBUG_KEXDH
1323 fprintf(stderr, "\ndh_client_pub= ");
1324 bignum_print(dh_client_pub);
1325 fprintf(stderr, "\n");
1326 debug("bits %d", BN_num_bits(dh_client_pub));
1327#endif
1328
1329 /* generate DH key */
1330 dh = dh_new_group1(); /* XXX depends on 'kex' */
1331
1332#ifdef DEBUG_KEXDH
1333 fprintf(stderr, "\np= ");
1334 bignum_print(dh->p);
1335 fprintf(stderr, "\ng= ");
1336 bignum_print(dh->g);
1337 fprintf(stderr, "\npub= ");
1338 bignum_print(dh->pub_key);
1339 fprintf(stderr, "\n");
1340#endif
1341 if (!dh_pub_is_valid(dh, dh_client_pub))
1342 packet_disconnect("bad client public DH value");
1343
1344 klen = DH_size(dh);
1345 kbuf = xmalloc(klen);
1346 kout = DH_compute_key(kbuf, dh_client_pub, dh);
1347
1348#ifdef DEBUG_KEXDH
1349 debug("shared secret: len %d/%d", klen, kout);
1350 fprintf(stderr, "shared secret == ");
1351 for (i = 0; i< kout; i++)
1352 fprintf(stderr, "%02x", (kbuf[i])&0xff);
1353 fprintf(stderr, "\n");
1354#endif
1355 shared_secret = BN_new();
1356
1357 BN_bin2bn(kbuf, kout, shared_secret);
1358 memset(kbuf, 0, klen);
1359 xfree(kbuf);
1360
1361 /* XXX precompute? */
1362 dsa_make_key_blob(sensitive_data.dsa_host_key, &server_host_key_blob, &sbloblen);
1363
1364 /* calc H */ /* XXX depends on 'kex' */
1365 hash = kex_hash(
1366 client_version_string,
1367 server_version_string,
1368 buffer_ptr(client_kexinit), buffer_len(client_kexinit),
1369 buffer_ptr(server_kexinit), buffer_len(server_kexinit),
1370 (char *)server_host_key_blob, sbloblen,
1371 dh_client_pub,
1372 dh->pub_key,
1373 shared_secret
1374 );
1375 buffer_free(client_kexinit);
1376 buffer_free(server_kexinit);
1377 xfree(client_kexinit);
1378 xfree(server_kexinit);
1379#ifdef DEBUG_KEXDH
1380 fprintf(stderr, "hash == ");
1381 for (i = 0; i< 20; i++)
1382 fprintf(stderr, "%02x", (hash[i])&0xff);
1383 fprintf(stderr, "\n");
1384#endif
1385 /* save session id := H */
1386 /* XXX hashlen depends on KEX */
1387 session_id2_len = 20;
1388 session_id2 = xmalloc(session_id2_len);
1389 memcpy(session_id2, hash, session_id2_len);
1390
1391 /* sign H */
1392 /* XXX hashlen depends on KEX */
1393 dsa_sign(sensitive_data.dsa_host_key, &signature, &slen, hash, 20);
1394
1395 destroy_sensitive_data();
1396
1397 /* send server hostkey, DH pubkey 'f' and singed H */
1398 packet_start(SSH2_MSG_KEXDH_REPLY);
1399 packet_put_string((char *)server_host_key_blob, sbloblen);
1400 packet_put_bignum2(dh->pub_key); /* f */
1401 packet_put_string((char *)signature, slen);
1402 packet_send();
1403 xfree(signature);
1404 xfree(server_host_key_blob);
1405 packet_write_wait();
1406
1407 kex_derive_keys(kex, hash, shared_secret);
1408 packet_set_kex(kex);
1409
1410 /* have keys, free DH */
1411 DH_free(dh);
1412
1413 debug("send SSH2_MSG_NEWKEYS.");
1414 packet_start(SSH2_MSG_NEWKEYS);
1415 packet_send();
1416 packet_write_wait();
1417 debug("done: send SSH2_MSG_NEWKEYS.");
1418
1419 debug("Wait SSH2_MSG_NEWKEYS.");
1420 packet_read_expect(&payload_len, SSH2_MSG_NEWKEYS);
1421 debug("GOT SSH2_MSG_NEWKEYS.");
1422
1423#ifdef DEBUG_KEXDH
1424 /* send 1st encrypted/maced/compressed message */
1425 packet_start(SSH2_MSG_IGNORE);
1426 packet_put_cstring("markus");
1427 packet_send();
1428 packet_write_wait();
1429#endif
1430 debug("done: KEX2.");
1431}