blob: c788ac016c0a450e7288178f2f7a63c911851605 [file] [log] [blame]
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001/*
Damien Miller95def091999-11-25 00:26:21 +11002 * Author: Tatu Ylonen <ylo@cs.hut.fi>
3 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 * All rights reserved
Damien Millere4340be2000-09-16 13:29:08 +11005 * This program is the ssh daemon. It listens for connections from clients,
6 * and performs authentication, executes use commands or shell, and forwards
Damien Miller95def091999-11-25 00:26:21 +11007 * information to/from the application to the user client over an encrypted
Damien Millere4340be2000-09-16 13:29:08 +11008 * connection. This can also handle forwarding of X11, TCP/IP, and
9 * authentication agent connections.
Damien Millerefb4afe2000-04-12 18:45:05 +100010 *
Damien Millere4340be2000-09-16 13:29:08 +110011 * 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".
16 *
17 * SSH2 implementation:
Ben Lindstrom7a2073c2002-03-22 02:30:41 +000018 * Privilege Separation:
Damien Millere4340be2000-09-16 13:29:08 +110019 *
Ben Lindstrom7a2073c2002-03-22 02:30:41 +000020 * Copyright (c) 2000, 2001, 2002 Markus Friedl. All rights reserved.
21 * Copyright (c) 2002 Niels Provos. All rights reserved.
Damien Millere4340be2000-09-16 13:29:08 +110022 *
23 * Redistribution and use in source and binary forms, with or without
24 * modification, are permitted provided that the following conditions
25 * are met:
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.
31 *
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.
Damien Miller95def091999-11-25 00:26:21 +110042 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100043
44#include "includes.h"
Ben Lindstrom7a7edf72002-03-22 02:42:37 +000045RCSID("$OpenBSD: sshd.c,v 1.232 2002/03/19 03:03:43 stevesk Exp $");
Damien Millerd4a8b7e1999-10-27 13:42:43 +100046
Ben Lindstrom226cfa02001-01-22 05:34:40 +000047#include <openssl/dh.h>
48#include <openssl/bn.h>
Damien Miller6a47f302002-02-13 13:55:06 +110049#include <openssl/md5.h>
Ben Lindstrom7a2073c2002-03-22 02:30:41 +000050#include <openssl/rand.h>
Ben Lindstrom226cfa02001-01-22 05:34:40 +000051
52#include "ssh.h"
53#include "ssh1.h"
54#include "ssh2.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100055#include "xmalloc.h"
56#include "rsa.h"
Ben Lindstromd95c09c2001-02-18 19:13:33 +000057#include "sshpty.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100058#include "packet.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100059#include "mpaux.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000060#include "log.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100061#include "servconf.h"
62#include "uidswap.h"
63#include "compat.h"
Damien Millerb38eff82000-04-01 11:09:21 +100064#include "buffer.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000065#include "cipher.h"
Damien Millerefb4afe2000-04-12 18:45:05 +100066#include "kex.h"
Damien Millerb38eff82000-04-01 11:09:21 +100067#include "key.h"
Damien Miller874d77b2000-10-14 16:23:11 +110068#include "dh.h"
Damien Millerefb4afe2000-04-12 18:45:05 +100069#include "myproposal.h"
Damien Millereba71ba2000-04-29 23:57:08 +100070#include "authfile.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000071#include "pathnames.h"
72#include "atomicio.h"
73#include "canohost.h"
74#include "auth.h"
75#include "misc.h"
Ben Lindstrom20d7c7b2001-04-04 01:56:17 +000076#include "dispatch.h"
Ben Lindstrom1bae4042001-10-03 17:46:39 +000077#include "channels.h"
Ben Lindstrom73ab9ba2002-03-22 01:27:35 +000078#include "session.h"
Ben Lindstrom7a2073c2002-03-22 02:30:41 +000079#include "monitor_mm.h"
80#include "monitor.h"
81#include "monitor_wrap.h"
82#include "monitor_fdpass.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100083
84#ifdef LIBWRAP
85#include <tcpd.h>
86#include <syslog.h>
87int allow_severity = LOG_INFO;
88int deny_severity = LOG_WARNING;
89#endif /* LIBWRAP */
90
91#ifndef O_NOCTTY
92#define O_NOCTTY 0
93#endif
94
Ben Lindstrom49a79c02000-11-17 03:47:20 +000095#ifdef HAVE___PROGNAME
96extern char *__progname;
97#else
98char *__progname;
99#endif
100
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000101/* Server configuration options. */
102ServerOptions options;
103
104/* Name of the server configuration file. */
Ben Lindstrom226cfa02001-01-22 05:34:40 +0000105char *config_file_name = _PATH_SERVER_CONFIG_FILE;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000106
Damien Miller4af51302000-04-16 11:18:38 +1000107/*
Damien Miller34132e52000-01-14 15:45:46 +1100108 * Flag indicating whether IPv4 or IPv6. This can be set on the command line.
109 * Default value is AF_UNSPEC means both IPv4 and IPv6.
110 */
Damien Miller7d80e342000-01-19 14:36:49 +1100111#ifdef IPV4_DEFAULT
112int IPv4or6 = AF_INET;
113#else
Damien Miller34132e52000-01-14 15:45:46 +1100114int IPv4or6 = AF_UNSPEC;
Damien Miller7d80e342000-01-19 14:36:49 +1100115#endif
Damien Miller34132e52000-01-14 15:45:46 +1100116
Damien Miller95def091999-11-25 00:26:21 +1100117/*
118 * Debug mode flag. This can be set on the command line. If debug
119 * mode is enabled, extra debugging output will be sent to the system
120 * log, the daemon will not go to background, and will exit after processing
121 * the first connection.
122 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000123int debug_flag = 0;
124
Ben Lindstrom794325a2001-08-06 21:09:07 +0000125/* Flag indicating that the daemon should only test the configuration and keys. */
126int test_flag = 0;
127
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000128/* Flag indicating that the daemon is being started from inetd. */
129int inetd_flag = 0;
130
Ben Lindstromc72745a2000-12-02 19:03:54 +0000131/* Flag indicating that sshd should not detach and become a daemon. */
132int no_daemon_flag = 0;
133
Damien Miller5ce662a1999-11-11 17:57:39 +1100134/* debug goes to stderr unless inetd_flag is set */
135int log_stderr = 0;
136
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000137/* Saved arguments to main(). */
138char **saved_argv;
Damien Millerb8c656e2000-06-28 15:22:41 +1000139int saved_argc;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000140
Damien Miller5428f641999-11-25 11:54:57 +1100141/*
Damien Miller34132e52000-01-14 15:45:46 +1100142 * The sockets that the server is listening; this is used in the SIGHUP
143 * signal handler.
Damien Miller5428f641999-11-25 11:54:57 +1100144 */
Damien Miller34132e52000-01-14 15:45:46 +1100145#define MAX_LISTEN_SOCKS 16
146int listen_socks[MAX_LISTEN_SOCKS];
147int num_listen_socks = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000148
Damien Miller5428f641999-11-25 11:54:57 +1100149/*
150 * the client's version string, passed by sshd2 in compat mode. if != NULL,
151 * sshd will skip the version-number exchange
152 */
Damien Miller95def091999-11-25 00:26:21 +1100153char *client_version_string = NULL;
Damien Millerb38eff82000-04-01 11:09:21 +1000154char *server_version_string = NULL;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000155
Ben Lindstrom8ac91062001-04-04 17:57:54 +0000156/* for rekeying XXX fixme */
157Kex *xxx_kex;
158
Damien Miller5428f641999-11-25 11:54:57 +1100159/*
160 * Any really sensitive data in the application is contained in this
161 * structure. The idea is that this structure could be locked into memory so
162 * that the pages do not get written into swap. However, there are some
163 * problems. The private key contains BIGNUMs, and we do not (in principle)
164 * have access to the internals of them, and locking just the structure is
165 * not very useful. Currently, memory locking is not implemented.
166 */
Damien Miller95def091999-11-25 00:26:21 +1100167struct {
Ben Lindstromca42d5f2001-03-09 18:25:32 +0000168 Key *server_key; /* ephemeral server key */
Damien Miller0bc1bd82000-11-13 22:57:25 +1100169 Key *ssh1_host_key; /* ssh1 host key */
170 Key **host_keys; /* all private host keys */
171 int have_ssh1_key;
172 int have_ssh2_key;
Ben Lindstromeb648a72001-03-05 06:00:29 +0000173 u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH];
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000174} sensitive_data;
175
Damien Miller5428f641999-11-25 11:54:57 +1100176/*
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000177 * Flag indicating whether the RSA server key needs to be regenerated.
178 * Is set in the SIGALRM handler and cleared when the key is regenerated.
Damien Miller5428f641999-11-25 11:54:57 +1100179 */
Ben Lindstrom5e71c542001-12-06 16:48:14 +0000180static volatile sig_atomic_t key_do_regen = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000181
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000182/* This is set to true when a signal is received. */
Ben Lindstrom5e71c542001-12-06 16:48:14 +0000183static volatile sig_atomic_t received_sighup = 0;
184static volatile sig_atomic_t received_sigterm = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000185
Damien Millerb38eff82000-04-01 11:09:21 +1000186/* session identifier, used by RSA-auth */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000187u_char session_id[16];
Damien Millerb38eff82000-04-01 11:09:21 +1000188
Damien Millereba71ba2000-04-29 23:57:08 +1000189/* same for ssh2 */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000190u_char *session_id2 = NULL;
Damien Millereba71ba2000-04-29 23:57:08 +1000191int session_id2_len = 0;
192
Damien Miller942da032000-08-18 13:59:06 +1000193/* record remote hostname or ip */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000194u_int utmp_len = MAXHOSTNAMELEN;
Damien Miller942da032000-08-18 13:59:06 +1000195
Ben Lindstromd84df982001-12-06 16:35:40 +0000196/* options.max_startup sized array of fd ints */
197int *startup_pipes = NULL;
198int startup_pipe; /* in child */
199
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000200/* variables used for privilege separation */
201extern struct monitor *monitor;
202extern int use_privsep;
203
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000204/* Prototypes for various functions defined later in this file. */
Ben Lindstrombba81212001-06-25 05:01:22 +0000205void destroy_sensitive_data(void);
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000206void demote_sensitive_data(void);
Damien Miller98c7ad62000-03-09 21:27:49 +1100207
Ben Lindstrombba81212001-06-25 05:01:22 +0000208static void do_ssh1_kex(void);
209static void do_ssh2_kex(void);
Damien Miller874d77b2000-10-14 16:23:11 +1100210
Damien Miller98c7ad62000-03-09 21:27:49 +1100211/*
Damien Miller34132e52000-01-14 15:45:46 +1100212 * Close all listening sockets
213 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000214static void
Damien Miller34132e52000-01-14 15:45:46 +1100215close_listen_socks(void)
216{
217 int i;
218 for (i = 0; i < num_listen_socks; i++)
219 close(listen_socks[i]);
220 num_listen_socks = -1;
221}
222
Ben Lindstromd84df982001-12-06 16:35:40 +0000223static void
224close_startup_pipes(void)
225{
226 int i;
227 if (startup_pipes)
228 for (i = 0; i < options.max_startups; i++)
229 if (startup_pipes[i] != -1)
230 close(startup_pipes[i]);
231}
232
Damien Miller34132e52000-01-14 15:45:46 +1100233/*
Damien Miller95def091999-11-25 00:26:21 +1100234 * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP;
235 * the effect is to reread the configuration file (and to regenerate
236 * the server key).
237 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000238static void
Damien Miller95def091999-11-25 00:26:21 +1100239sighup_handler(int sig)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000240{
Ben Lindstrom07958482001-12-06 16:19:01 +0000241 int save_errno = errno;
242
Damien Miller95def091999-11-25 00:26:21 +1100243 received_sighup = 1;
244 signal(SIGHUP, sighup_handler);
Ben Lindstrom07958482001-12-06 16:19:01 +0000245 errno = save_errno;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000246}
247
Damien Miller95def091999-11-25 00:26:21 +1100248/*
249 * Called from the main program after receiving SIGHUP.
250 * Restarts the server.
251 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000252static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000253sighup_restart(void)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000254{
Damien Miller95def091999-11-25 00:26:21 +1100255 log("Received SIGHUP; restarting.");
Damien Miller34132e52000-01-14 15:45:46 +1100256 close_listen_socks();
Ben Lindstromd84df982001-12-06 16:35:40 +0000257 close_startup_pipes();
Damien Miller95def091999-11-25 00:26:21 +1100258 execv(saved_argv[0], saved_argv);
Kevin Stevesec84dc12000-12-13 17:45:15 +0000259 log("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0], strerror(errno));
Damien Miller95def091999-11-25 00:26:21 +1100260 exit(1);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000261}
262
Damien Miller95def091999-11-25 00:26:21 +1100263/*
264 * Generic signal handler for terminating signals in the master daemon.
Damien Miller95def091999-11-25 00:26:21 +1100265 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000266static void
Damien Miller95def091999-11-25 00:26:21 +1100267sigterm_handler(int sig)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000268{
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000269 received_sigterm = sig;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000270}
271
Damien Miller95def091999-11-25 00:26:21 +1100272/*
273 * SIGCHLD handler. This is called whenever a child dies. This will then
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000274 * reap any zombies left by exited children.
Damien Miller95def091999-11-25 00:26:21 +1100275 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000276static void
Damien Miller95def091999-11-25 00:26:21 +1100277main_sigchld_handler(int sig)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000278{
Damien Miller95def091999-11-25 00:26:21 +1100279 int save_errno = errno;
280 int status;
Damien Miller431f66b1999-11-21 18:31:57 +1100281
Damien Miller95def091999-11-25 00:26:21 +1100282 while (waitpid(-1, &status, WNOHANG) > 0)
283 ;
Damien Miller431f66b1999-11-21 18:31:57 +1100284
Damien Miller95def091999-11-25 00:26:21 +1100285 signal(SIGCHLD, main_sigchld_handler);
286 errno = save_errno;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000287}
288
Damien Miller95def091999-11-25 00:26:21 +1100289/*
290 * Signal handler for the alarm after the login grace period has expired.
291 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000292static void
Damien Miller95def091999-11-25 00:26:21 +1100293grace_alarm_handler(int sig)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000294{
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000295 /* XXX no idea how fix this signal handler */
296
Damien Miller95def091999-11-25 00:26:21 +1100297 /* Close the connection. */
298 packet_close();
299
300 /* Log error and exit. */
301 fatal("Timeout before authentication for %s.", get_remote_ipaddr());
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000302}
303
Damien Miller95def091999-11-25 00:26:21 +1100304/*
Damien Miller95def091999-11-25 00:26:21 +1100305 * Signal handler for the key regeneration alarm. Note that this
306 * alarm only occurs in the daemon waiting for connections, and it does not
307 * do anything with the private key or random state before forking.
308 * Thus there should be no concurrency control/asynchronous execution
309 * problems.
310 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000311static void
Ben Lindstromca42d5f2001-03-09 18:25:32 +0000312generate_ephemeral_server_key(void)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100313{
Ben Lindstromeb648a72001-03-05 06:00:29 +0000314 u_int32_t rand = 0;
315 int i;
316
Ben Lindstroma3700052001-04-05 23:26:32 +0000317 verbose("Generating %s%d bit RSA key.",
Damien Millerff75ac42001-03-30 10:50:32 +1000318 sensitive_data.server_key ? "new " : "", options.server_key_bits);
Damien Miller0bc1bd82000-11-13 22:57:25 +1100319 if (sensitive_data.server_key != NULL)
320 key_free(sensitive_data.server_key);
Ben Lindstroma3700052001-04-05 23:26:32 +0000321 sensitive_data.server_key = key_generate(KEY_RSA1,
Damien Millerff75ac42001-03-30 10:50:32 +1000322 options.server_key_bits);
323 verbose("RSA key generation complete.");
Ben Lindstromeb648a72001-03-05 06:00:29 +0000324
325 for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) {
326 if (i % 4 == 0)
327 rand = arc4random();
328 sensitive_data.ssh1_cookie[i] = rand & 0xff;
329 rand >>= 8;
330 }
331 arc4random_stir();
Damien Miller0bc1bd82000-11-13 22:57:25 +1100332}
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000333
Ben Lindstrombba81212001-06-25 05:01:22 +0000334static void
Damien Miller95def091999-11-25 00:26:21 +1100335key_regeneration_alarm(int sig)
336{
337 int save_errno = errno;
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000338 signal(SIGALRM, SIG_DFL);
Damien Miller95def091999-11-25 00:26:21 +1100339 errno = save_errno;
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000340 key_do_regen = 1;
Damien Miller95def091999-11-25 00:26:21 +1100341}
342
Ben Lindstrombba81212001-06-25 05:01:22 +0000343static void
Damien Millerb38eff82000-04-01 11:09:21 +1000344sshd_exchange_identification(int sock_in, int sock_out)
345{
Damien Miller78928792000-04-12 20:17:38 +1000346 int i, mismatch;
Damien Millerb38eff82000-04-01 11:09:21 +1000347 int remote_major, remote_minor;
Damien Miller78928792000-04-12 20:17:38 +1000348 int major, minor;
Damien Millerb38eff82000-04-01 11:09:21 +1000349 char *s;
350 char buf[256]; /* Must not be larger than remote_version. */
351 char remote_version[256]; /* Must be at least as big as buf. */
352
Damien Miller78928792000-04-12 20:17:38 +1000353 if ((options.protocol & SSH_PROTO_1) &&
354 (options.protocol & SSH_PROTO_2)) {
355 major = PROTOCOL_MAJOR_1;
356 minor = 99;
357 } else if (options.protocol & SSH_PROTO_2) {
358 major = PROTOCOL_MAJOR_2;
359 minor = PROTOCOL_MINOR_2;
360 } else {
361 major = PROTOCOL_MAJOR_1;
362 minor = PROTOCOL_MINOR_1;
363 }
364 snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", major, minor, SSH_VERSION);
Damien Millerb38eff82000-04-01 11:09:21 +1000365 server_version_string = xstrdup(buf);
366
367 if (client_version_string == NULL) {
368 /* Send our protocol version identification. */
369 if (atomicio(write, sock_out, server_version_string, strlen(server_version_string))
370 != strlen(server_version_string)) {
Damien Millere4a0ff42001-11-12 11:06:54 +1100371 log("Could not write ident string to %s", get_remote_ipaddr());
Damien Millerb38eff82000-04-01 11:09:21 +1000372 fatal_cleanup();
373 }
374
Ben Lindstrom5393f932001-02-15 03:17:13 +0000375 /* Read other side's version identification. */
Ben Lindstroma3700052001-04-05 23:26:32 +0000376 memset(buf, 0, sizeof(buf));
Damien Millerb38eff82000-04-01 11:09:21 +1000377 for (i = 0; i < sizeof(buf) - 1; i++) {
Damien Millerbf7f4662000-06-23 10:16:38 +1000378 if (atomicio(read, sock_in, &buf[i], 1) != 1) {
Damien Millere4a0ff42001-11-12 11:06:54 +1100379 log("Did not receive identification string from %s",
Ben Lindstroma9a29e12001-02-20 01:20:47 +0000380 get_remote_ipaddr());
Damien Millerb38eff82000-04-01 11:09:21 +1000381 fatal_cleanup();
382 }
383 if (buf[i] == '\r') {
Ben Lindstrom69d8c072001-03-22 22:45:33 +0000384 buf[i] = 0;
Damien Miller874d77b2000-10-14 16:23:11 +1100385 /* Kludge for F-Secure Macintosh < 1.0.2 */
386 if (i == 12 &&
387 strncmp(buf, "SSH-1.5-W1.0", 12) == 0)
388 break;
Damien Millerb38eff82000-04-01 11:09:21 +1000389 continue;
Damien Millerb38eff82000-04-01 11:09:21 +1000390 }
391 if (buf[i] == '\n') {
Ben Lindstrom69d8c072001-03-22 22:45:33 +0000392 buf[i] = 0;
Damien Millerb38eff82000-04-01 11:09:21 +1000393 break;
394 }
395 }
396 buf[sizeof(buf) - 1] = 0;
397 client_version_string = xstrdup(buf);
398 }
399
400 /*
401 * Check that the versions match. In future this might accept
402 * several versions and set appropriate flags to handle them.
403 */
404 if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n",
405 &remote_major, &remote_minor, remote_version) != 3) {
Damien Miller4af51302000-04-16 11:18:38 +1000406 s = "Protocol mismatch.\n";
Damien Millerb38eff82000-04-01 11:09:21 +1000407 (void) atomicio(write, sock_out, s, strlen(s));
408 close(sock_in);
409 close(sock_out);
410 log("Bad protocol version identification '%.100s' from %s",
411 client_version_string, get_remote_ipaddr());
412 fatal_cleanup();
413 }
414 debug("Client protocol version %d.%d; client software version %.100s",
Damien Miller9f0f5c62001-12-21 14:45:46 +1100415 remote_major, remote_minor, remote_version);
Damien Millerb38eff82000-04-01 11:09:21 +1000416
Damien Millerefb4afe2000-04-12 18:45:05 +1000417 compat_datafellows(remote_version);
418
Damien Miller27dbe6f2001-03-19 22:36:20 +1100419 if (datafellows & SSH_BUG_SCANNER) {
420 log("scanned from %s with %s. Don't panic.",
421 get_remote_ipaddr(), client_version_string);
422 fatal_cleanup();
423 }
424
Damien Miller78928792000-04-12 20:17:38 +1000425 mismatch = 0;
Ben Lindstrom1c37c6a2001-12-06 18:00:18 +0000426 switch (remote_major) {
Damien Millerb38eff82000-04-01 11:09:21 +1000427 case 1:
Damien Millereba71ba2000-04-29 23:57:08 +1000428 if (remote_minor == 99) {
429 if (options.protocol & SSH_PROTO_2)
430 enable_compat20();
431 else
432 mismatch = 1;
433 break;
434 }
Damien Miller78928792000-04-12 20:17:38 +1000435 if (!(options.protocol & SSH_PROTO_1)) {
436 mismatch = 1;
437 break;
438 }
Damien Millerb38eff82000-04-01 11:09:21 +1000439 if (remote_minor < 3) {
Damien Miller37023962000-07-11 17:31:38 +1000440 packet_disconnect("Your ssh version is too old and "
Damien Millerb38eff82000-04-01 11:09:21 +1000441 "is no longer supported. Please install a newer version.");
442 } else if (remote_minor == 3) {
443 /* note that this disables agent-forwarding */
444 enable_compat13();
445 }
Damien Miller78928792000-04-12 20:17:38 +1000446 break;
Damien Millerefb4afe2000-04-12 18:45:05 +1000447 case 2:
Damien Miller78928792000-04-12 20:17:38 +1000448 if (options.protocol & SSH_PROTO_2) {
Damien Millerefb4afe2000-04-12 18:45:05 +1000449 enable_compat20();
450 break;
451 }
452 /* FALLTHROUGH */
Damien Miller4af51302000-04-16 11:18:38 +1000453 default:
Damien Miller78928792000-04-12 20:17:38 +1000454 mismatch = 1;
Damien Millerb38eff82000-04-01 11:09:21 +1000455 break;
456 }
Damien Millerefb4afe2000-04-12 18:45:05 +1000457 chop(server_version_string);
Damien Miller78928792000-04-12 20:17:38 +1000458 debug("Local version string %.200s", server_version_string);
459
460 if (mismatch) {
461 s = "Protocol major versions differ.\n";
462 (void) atomicio(write, sock_out, s, strlen(s));
463 close(sock_in);
464 close(sock_out);
465 log("Protocol major versions differ for %s: %.200s vs. %.200s",
466 get_remote_ipaddr(),
467 server_version_string, client_version_string);
468 fatal_cleanup();
469 }
Damien Millereba71ba2000-04-29 23:57:08 +1000470}
471
472
Damien Miller0bc1bd82000-11-13 22:57:25 +1100473/* Destroy the host and server keys. They will no longer be needed. */
Damien Millereba71ba2000-04-29 23:57:08 +1000474void
475destroy_sensitive_data(void)
476{
Damien Miller0bc1bd82000-11-13 22:57:25 +1100477 int i;
478
479 if (sensitive_data.server_key) {
480 key_free(sensitive_data.server_key);
481 sensitive_data.server_key = NULL;
482 }
Damien Miller9f0f5c62001-12-21 14:45:46 +1100483 for (i = 0; i < options.num_host_key_files; i++) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100484 if (sensitive_data.host_keys[i]) {
485 key_free(sensitive_data.host_keys[i]);
486 sensitive_data.host_keys[i] = NULL;
487 }
488 }
489 sensitive_data.ssh1_host_key = NULL;
Ben Lindstromeb648a72001-03-05 06:00:29 +0000490 memset(sensitive_data.ssh1_cookie, 0, SSH_SESSION_KEY_LENGTH);
Damien Miller0bc1bd82000-11-13 22:57:25 +1100491}
Damien Miller0bc1bd82000-11-13 22:57:25 +1100492
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000493/* Demote private to public keys for network child */
494void
495demote_sensitive_data(void)
496{
497 Key *tmp;
498 int i;
499
500 if (sensitive_data.server_key) {
501 tmp = key_demote(sensitive_data.server_key);
502 key_free(sensitive_data.server_key);
503 sensitive_data.server_key = tmp;
504 }
505
506 for (i = 0; i < options.num_host_key_files; i++) {
507 if (sensitive_data.host_keys[i]) {
508 tmp = key_demote(sensitive_data.host_keys[i]);
509 key_free(sensitive_data.host_keys[i]);
510 sensitive_data.host_keys[i] = tmp;
511 if (tmp->type == KEY_RSA1)
512 sensitive_data.ssh1_host_key = tmp;
513 }
514 }
515
516 /* We do not clear ssh1_host key and cookie. XXX - Okay Niels? */
517}
518
519void
520privsep_preauth_child(void)
521{
522 u_int32_t rand[256];
523 int i;
524
525 /* Enable challenge-response authentication for privilege separation */
526 privsep_challenge_enable();
527
528 for (i = 0; i < 256; i++)
529 rand[i] = arc4random();
530 RAND_seed(rand, sizeof(rand));
531
532 /* Demote the private keys to public keys. */
533 demote_sensitive_data();
534
535 /* Change our root directory*/
Ben Lindstrom7a7edf72002-03-22 02:42:37 +0000536 if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1)
537 fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR,
538 strerror(errno));
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000539 if (chdir("/") == -1)
540 fatal("chdir(/)");
541
542 /* Drop our privileges */
543 setegid(options.unprivileged_group);
544 setgid(options.unprivileged_group);
545 seteuid(options.unprivileged_user);
546 setuid(options.unprivileged_user);
547}
548
549void
550privsep_postauth(Authctxt *authctxt, pid_t pid)
551{
552 extern Authctxt *x_authctxt;
553 int status;
554
555 /* Wait for the child's exit status */
556 waitpid(pid, &status, 0);
557
558 /* XXX - Remote port forwarding */
559 x_authctxt = authctxt;
560
561 if (authctxt->pw->pw_uid == 0 || options.use_login) {
562 /* File descriptor passing is broken or root login */
563 monitor_apply_keystate(monitor);
564 use_privsep = 0;
565 return;
566 }
567
568 /* Authentication complete */
569 alarm(0);
570 if (startup_pipe != -1) {
571 close(startup_pipe);
572 startup_pipe = -1;
573 }
574
575 /* New socket pair */
576 monitor_reinit(monitor);
577
578 monitor->m_pid = fork();
579 if (monitor->m_pid == -1)
580 fatal("fork of unprivileged child failed");
581 else if (monitor->m_pid != 0) {
582 debug2("User child is on pid %d", pid);
583 close(monitor->m_recvfd);
584 monitor_child_postauth(monitor);
585
586 /* NEVERREACHED */
587 exit(0);
588 }
589
590 close(monitor->m_sendfd);
591
592 /* Demote the private keys to public keys. */
593 demote_sensitive_data();
594
595 /* Drop privileges */
596 do_setusercontext(authctxt->pw);
597
598 /* It is safe now to apply the key state */
599 monitor_apply_keystate(monitor);
600}
601
602
Ben Lindstrombba81212001-06-25 05:01:22 +0000603static char *
Damien Miller0bc1bd82000-11-13 22:57:25 +1100604list_hostkey_types(void)
605{
Damien Miller0e3b8722002-01-22 23:26:38 +1100606 Buffer b;
607 char *p;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100608 int i;
Damien Miller0e3b8722002-01-22 23:26:38 +1100609
610 buffer_init(&b);
Damien Miller9f0f5c62001-12-21 14:45:46 +1100611 for (i = 0; i < options.num_host_key_files; i++) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100612 Key *key = sensitive_data.host_keys[i];
613 if (key == NULL)
614 continue;
Ben Lindstrom1c37c6a2001-12-06 18:00:18 +0000615 switch (key->type) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100616 case KEY_RSA:
617 case KEY_DSA:
Damien Miller0e3b8722002-01-22 23:26:38 +1100618 if (buffer_len(&b) > 0)
619 buffer_append(&b, ",", 1);
620 p = key_ssh_name(key);
621 buffer_append(&b, p, strlen(p));
Damien Miller0bc1bd82000-11-13 22:57:25 +1100622 break;
623 }
624 }
Damien Miller0e3b8722002-01-22 23:26:38 +1100625 buffer_append(&b, "\0", 1);
626 p = xstrdup(buffer_ptr(&b));
627 buffer_free(&b);
628 debug("list_hostkey_types: %s", p);
629 return p;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100630}
631
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000632Key *
Damien Miller0bc1bd82000-11-13 22:57:25 +1100633get_hostkey_by_type(int type)
634{
635 int i;
Damien Miller9f0f5c62001-12-21 14:45:46 +1100636 for (i = 0; i < options.num_host_key_files; i++) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100637 Key *key = sensitive_data.host_keys[i];
638 if (key != NULL && key->type == type)
639 return key;
640 }
641 return NULL;
Damien Millerb38eff82000-04-01 11:09:21 +1000642}
643
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000644Key *
645get_hostkey_by_index(int ind)
646{
647 if (ind < 0 || ind >= options.num_host_key_files)
648 return (NULL);
649 return (sensitive_data.host_keys[ind]);
650}
651
652int
653get_hostkey_index(Key *key)
654{
655 int i;
656 for (i = 0; i < options.num_host_key_files; i++) {
657 if (key == sensitive_data.host_keys[i])
658 return (i);
659 }
660 return (-1);
661}
662
Damien Miller942da032000-08-18 13:59:06 +1000663/*
664 * returns 1 if connection should be dropped, 0 otherwise.
665 * dropping starts at connection #max_startups_begin with a probability
666 * of (max_startups_rate/100). the probability increases linearly until
667 * all connections are dropped for startups > max_startups
668 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000669static int
Damien Miller942da032000-08-18 13:59:06 +1000670drop_connection(int startups)
671{
672 double p, r;
673
674 if (startups < options.max_startups_begin)
675 return 0;
676 if (startups >= options.max_startups)
677 return 1;
678 if (options.max_startups_rate == 100)
679 return 1;
680
681 p = 100 - options.max_startups_rate;
682 p *= startups - options.max_startups_begin;
683 p /= (double) (options.max_startups - options.max_startups_begin);
684 p += options.max_startups_rate;
685 p /= 100.0;
686 r = arc4random() / (double) UINT_MAX;
687
688 debug("drop_connection: p %g, r %g", p, r);
689 return (r < p) ? 1 : 0;
690}
691
Ben Lindstromade03f62001-12-06 18:22:17 +0000692static void
693usage(void)
694{
695 fprintf(stderr, "sshd version %s\n", SSH_VERSION);
696 fprintf(stderr, "Usage: %s [options]\n", __progname);
697 fprintf(stderr, "Options:\n");
698 fprintf(stderr, " -f file Configuration file (default %s)\n", _PATH_SERVER_CONFIG_FILE);
699 fprintf(stderr, " -d Debugging mode (multiple -d means more debugging)\n");
700 fprintf(stderr, " -i Started from inetd\n");
701 fprintf(stderr, " -D Do not fork into daemon mode\n");
702 fprintf(stderr, " -t Only test configuration file and keys\n");
703 fprintf(stderr, " -q Quiet (no logging)\n");
704 fprintf(stderr, " -p port Listen on the specified port (default: 22)\n");
705 fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n");
706 fprintf(stderr, " -g seconds Grace period for authentication (default: 600)\n");
707 fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n");
708 fprintf(stderr, " -h file File from which to read host key (default: %s)\n",
709 _PATH_HOST_KEY_FILE);
710 fprintf(stderr, " -u len Maximum hostname length for utmp recording\n");
711 fprintf(stderr, " -4 Use IPv4 only\n");
712 fprintf(stderr, " -6 Use IPv6 only\n");
713 fprintf(stderr, " -o option Process the option as if it was read from a configuration file.\n");
714 exit(1);
715}
716
Damien Miller95def091999-11-25 00:26:21 +1100717/*
718 * Main program for the daemon.
719 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000720int
721main(int ac, char **av)
722{
Damien Miller95def091999-11-25 00:26:21 +1100723 extern char *optarg;
724 extern int optind;
Damien Miller37023962000-07-11 17:31:38 +1000725 int opt, sock_in = 0, sock_out = 0, newsock, j, i, fdsetsz, on = 1;
Damien Miller166fca82000-04-20 07:42:21 +1000726 pid_t pid;
Damien Miller34132e52000-01-14 15:45:46 +1100727 socklen_t fromlen;
Damien Miller34132e52000-01-14 15:45:46 +1100728 fd_set *fdset;
729 struct sockaddr_storage from;
Damien Miller95def091999-11-25 00:26:21 +1100730 const char *remote_ip;
731 int remote_port;
Damien Miller95def091999-11-25 00:26:21 +1100732 FILE *f;
733 struct linger linger;
Damien Miller34132e52000-01-14 15:45:46 +1100734 struct addrinfo *ai;
735 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
736 int listen_sock, maxfd;
Damien Miller37023962000-07-11 17:31:38 +1000737 int startup_p[2];
738 int startups = 0;
Ben Lindstrom73ab9ba2002-03-22 01:27:35 +0000739 Authctxt *authctxt;
Ben Lindstromd0fca422001-03-26 13:44:06 +0000740 Key *key;
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000741 int ret, key_used = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000742
Ben Lindstrom49a79c02000-11-17 03:47:20 +0000743 __progname = get_progname(av[0]);
Damien Millerf9b625c2000-07-09 22:42:32 +1000744 init_rng();
745
Kevin Stevesec84dc12000-12-13 17:45:15 +0000746 /* Save argv. */
Damien Millerb8c656e2000-06-28 15:22:41 +1000747 saved_argc = ac;
Damien Miller95def091999-11-25 00:26:21 +1100748 saved_argv = av;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000749
Damien Miller95def091999-11-25 00:26:21 +1100750 /* Initialize configuration options to their default values. */
751 initialize_server_options(&options);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000752
Damien Miller95def091999-11-25 00:26:21 +1100753 /* Parse command-line arguments. */
Ben Lindstromade03f62001-12-06 18:22:17 +0000754 while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:u:o:dDeiqtQ46")) != -1) {
Damien Miller95def091999-11-25 00:26:21 +1100755 switch (opt) {
Damien Miller34132e52000-01-14 15:45:46 +1100756 case '4':
757 IPv4or6 = AF_INET;
758 break;
759 case '6':
760 IPv4or6 = AF_INET6;
761 break;
Damien Miller95def091999-11-25 00:26:21 +1100762 case 'f':
763 config_file_name = optarg;
764 break;
765 case 'd':
Damien Millere4340be2000-09-16 13:29:08 +1100766 if (0 == debug_flag) {
767 debug_flag = 1;
768 options.log_level = SYSLOG_LEVEL_DEBUG1;
769 } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) {
770 options.log_level++;
771 } else {
772 fprintf(stderr, "Too high debugging level.\n");
773 exit(1);
774 }
Damien Miller95def091999-11-25 00:26:21 +1100775 break;
Ben Lindstromc72745a2000-12-02 19:03:54 +0000776 case 'D':
777 no_daemon_flag = 1;
778 break;
Ben Lindstrom9fce9f02001-04-11 23:10:09 +0000779 case 'e':
780 log_stderr = 1;
781 break;
Damien Miller95def091999-11-25 00:26:21 +1100782 case 'i':
783 inetd_flag = 1;
784 break;
785 case 'Q':
Ben Lindstromd5390202001-01-29 08:07:43 +0000786 /* ignored */
Damien Miller95def091999-11-25 00:26:21 +1100787 break;
788 case 'q':
789 options.log_level = SYSLOG_LEVEL_QUIET;
790 break;
791 case 'b':
792 options.server_key_bits = atoi(optarg);
793 break;
794 case 'p':
Damien Miller34132e52000-01-14 15:45:46 +1100795 options.ports_from_cmdline = 1;
Damien Millere4340be2000-09-16 13:29:08 +1100796 if (options.num_ports >= MAX_PORTS) {
797 fprintf(stderr, "too many ports.\n");
798 exit(1);
799 }
Ben Lindstrom19066a12001-04-12 23:39:26 +0000800 options.ports[options.num_ports++] = a2port(optarg);
801 if (options.ports[options.num_ports-1] == 0) {
802 fprintf(stderr, "Bad port number.\n");
803 exit(1);
804 }
Damien Miller95def091999-11-25 00:26:21 +1100805 break;
806 case 'g':
Ben Lindstrom1bda4c82001-06-05 19:59:08 +0000807 if ((options.login_grace_time = convtime(optarg)) == -1) {
808 fprintf(stderr, "Invalid login grace time.\n");
809 exit(1);
810 }
Damien Miller95def091999-11-25 00:26:21 +1100811 break;
812 case 'k':
Ben Lindstrom1bda4c82001-06-05 19:59:08 +0000813 if ((options.key_regeneration_time = convtime(optarg)) == -1) {
814 fprintf(stderr, "Invalid key regeneration interval.\n");
815 exit(1);
816 }
Damien Miller95def091999-11-25 00:26:21 +1100817 break;
818 case 'h':
Damien Miller0bc1bd82000-11-13 22:57:25 +1100819 if (options.num_host_key_files >= MAX_HOSTKEYS) {
820 fprintf(stderr, "too many host keys.\n");
821 exit(1);
822 }
823 options.host_key_files[options.num_host_key_files++] = optarg;
Damien Miller95def091999-11-25 00:26:21 +1100824 break;
825 case 'V':
826 client_version_string = optarg;
827 /* only makes sense with inetd_flag, i.e. no listen() */
828 inetd_flag = 1;
829 break;
Ben Lindstrom794325a2001-08-06 21:09:07 +0000830 case 't':
831 test_flag = 1;
832 break;
Damien Miller942da032000-08-18 13:59:06 +1000833 case 'u':
834 utmp_len = atoi(optarg);
835 break;
Ben Lindstromade03f62001-12-06 18:22:17 +0000836 case 'o':
Damien Miller9f0f5c62001-12-21 14:45:46 +1100837 if (process_server_config_line(&options, optarg,
Ben Lindstromade03f62001-12-06 18:22:17 +0000838 "command-line", 0) != 0)
Damien Miller9f0f5c62001-12-21 14:45:46 +1100839 exit(1);
Ben Lindstromade03f62001-12-06 18:22:17 +0000840 break;
Damien Miller95def091999-11-25 00:26:21 +1100841 case '?':
842 default:
Ben Lindstromade03f62001-12-06 18:22:17 +0000843 usage();
844 break;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000845 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000846 }
Ben Lindstrom425fb022001-03-29 00:31:20 +0000847 SSLeay_add_all_algorithms();
Ben Lindstrom908afed2001-10-03 17:34:59 +0000848 channel_set_af(IPv4or6);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000849
Damien Miller34132e52000-01-14 15:45:46 +1100850 /*
851 * Force logging to stderr until we have loaded the private host
852 * key (unless started from inetd)
853 */
Kevin Stevesec84dc12000-12-13 17:45:15 +0000854 log_init(__progname,
Damien Miller5aa5d782002-02-08 22:01:54 +1100855 options.log_level == SYSLOG_LEVEL_NOT_SET ?
856 SYSLOG_LEVEL_INFO : options.log_level,
857 options.log_facility == SYSLOG_FACILITY_NOT_SET ?
858 SYSLOG_FACILITY_AUTH : options.log_facility,
Ben Lindstromd5390202001-01-29 08:07:43 +0000859 !inetd_flag);
Damien Miller34132e52000-01-14 15:45:46 +1100860
Ben Lindstrom6db66ff2001-08-06 23:29:16 +0000861#ifdef _CRAY
862 /* Cray can define user privs drop all prives now!
863 * Not needed on PRIV_SU systems!
864 */
865 drop_cray_privs();
866#endif
867
Damien Miller60bc5172001-03-19 09:38:15 +1100868 seed_rng();
869
Damien Miller95def091999-11-25 00:26:21 +1100870 /* Read server configuration options from the configuration file. */
871 read_server_config(&options, config_file_name);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000872
Damien Miller95def091999-11-25 00:26:21 +1100873 /* Fill in default values for those options not explicitly set. */
874 fill_default_server_options(&options);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000875
Damien Miller95def091999-11-25 00:26:21 +1100876 /* Check that there are no remaining arguments. */
877 if (optind < ac) {
878 fprintf(stderr, "Extra argument %s.\n", av[optind]);
879 exit(1);
880 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000881
Damien Miller95def091999-11-25 00:26:21 +1100882 debug("sshd version %.100s", SSH_VERSION);
Damien Miller2ccf6611999-11-15 15:25:10 +1100883
Damien Miller0bc1bd82000-11-13 22:57:25 +1100884 /* load private host keys */
885 sensitive_data.host_keys = xmalloc(options.num_host_key_files*sizeof(Key*));
Damien Miller9f0f5c62001-12-21 14:45:46 +1100886 for (i = 0; i < options.num_host_key_files; i++)
Ben Lindstrom46c16222000-12-22 01:43:59 +0000887 sensitive_data.host_keys[i] = NULL;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100888 sensitive_data.server_key = NULL;
889 sensitive_data.ssh1_host_key = NULL;
890 sensitive_data.have_ssh1_key = 0;
891 sensitive_data.have_ssh2_key = 0;
Damien Millereba71ba2000-04-29 23:57:08 +1000892
Damien Miller9f0f5c62001-12-21 14:45:46 +1100893 for (i = 0; i < options.num_host_key_files; i++) {
Ben Lindstromd0fca422001-03-26 13:44:06 +0000894 key = key_load_private(options.host_key_files[i], "", NULL);
895 sensitive_data.host_keys[i] = key;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100896 if (key == NULL) {
Ben Lindstrom15f33862001-04-16 02:00:02 +0000897 error("Could not load host key: %s",
898 options.host_key_files[i]);
Ben Lindstromd0fca422001-03-26 13:44:06 +0000899 sensitive_data.host_keys[i] = NULL;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100900 continue;
901 }
Ben Lindstrom1c37c6a2001-12-06 18:00:18 +0000902 switch (key->type) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100903 case KEY_RSA1:
904 sensitive_data.ssh1_host_key = key;
905 sensitive_data.have_ssh1_key = 1;
906 break;
907 case KEY_RSA:
908 case KEY_DSA:
909 sensitive_data.have_ssh2_key = 1;
910 break;
911 }
Ben Lindstromd0fca422001-03-26 13:44:06 +0000912 debug("private host key: #%d type %d %s", i, key->type,
913 key_type(key));
Damien Miller0bc1bd82000-11-13 22:57:25 +1100914 }
915 if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) {
916 log("Disabling protocol version 1. Could not load host key");
Damien Millereba71ba2000-04-29 23:57:08 +1000917 options.protocol &= ~SSH_PROTO_1;
918 }
Damien Miller0bc1bd82000-11-13 22:57:25 +1100919 if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) {
920 log("Disabling protocol version 2. Could not load host key");
921 options.protocol &= ~SSH_PROTO_2;
Damien Millereba71ba2000-04-29 23:57:08 +1000922 }
Kevin Stevesadf74cd2001-02-05 14:22:50 +0000923 if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
Ben Lindstrom6df8ef42001-03-05 07:47:23 +0000924 log("sshd: no hostkeys available -- exiting.");
Damien Miller95def091999-11-25 00:26:21 +1100925 exit(1);
926 }
Damien Miller95def091999-11-25 00:26:21 +1100927
Damien Millereba71ba2000-04-29 23:57:08 +1000928 /* Check certain values for sanity. */
929 if (options.protocol & SSH_PROTO_1) {
930 if (options.server_key_bits < 512 ||
931 options.server_key_bits > 32768) {
932 fprintf(stderr, "Bad server key size.\n");
933 exit(1);
934 }
935 /*
936 * Check that server and host key lengths differ sufficiently. This
937 * is necessary to make double encryption work with rsaref. Oh, I
938 * hate software patents. I dont know if this can go? Niels
939 */
940 if (options.server_key_bits >
Damien Miller0bc1bd82000-11-13 22:57:25 +1100941 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) - SSH_KEY_BITS_RESERVED &&
Damien Millereba71ba2000-04-29 23:57:08 +1000942 options.server_key_bits <
Damien Miller0bc1bd82000-11-13 22:57:25 +1100943 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
Damien Millereba71ba2000-04-29 23:57:08 +1000944 options.server_key_bits =
Damien Miller0bc1bd82000-11-13 22:57:25 +1100945 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED;
Damien Millereba71ba2000-04-29 23:57:08 +1000946 debug("Forcing server key to %d bits to make it differ from host key.",
947 options.server_key_bits);
948 }
949 }
950
Ben Lindstrom794325a2001-08-06 21:09:07 +0000951 /* Configuration looks good, so exit if in test mode. */
952 if (test_flag)
953 exit(0);
954
Damien Miller78315eb2000-09-29 23:01:36 +1100955#ifdef HAVE_SCO_PROTECTED_PW
956 (void) set_auth_parameters(ac, av);
957#endif
958
Damien Millereba71ba2000-04-29 23:57:08 +1000959 /* Initialize the log (it is reinitialized below in case we forked). */
Damien Miller95def091999-11-25 00:26:21 +1100960 if (debug_flag && !inetd_flag)
961 log_stderr = 1;
Kevin Stevesec84dc12000-12-13 17:45:15 +0000962 log_init(__progname, options.log_level, options.log_facility, log_stderr);
Damien Miller95def091999-11-25 00:26:21 +1100963
Damien Millereba71ba2000-04-29 23:57:08 +1000964 /*
965 * If not in debugging mode, and not started from inetd, disconnect
966 * from the controlling terminal, and fork. The original process
967 * exits.
968 */
Ben Lindstromc72745a2000-12-02 19:03:54 +0000969 if (!(debug_flag || inetd_flag || no_daemon_flag)) {
Damien Miller95def091999-11-25 00:26:21 +1100970#ifdef TIOCNOTTY
971 int fd;
972#endif /* TIOCNOTTY */
973 if (daemon(0, 0) < 0)
974 fatal("daemon() failed: %.200s", strerror(errno));
975
976 /* Disconnect from the controlling tty. */
977#ifdef TIOCNOTTY
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000978 fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
Damien Miller95def091999-11-25 00:26:21 +1100979 if (fd >= 0) {
980 (void) ioctl(fd, TIOCNOTTY, NULL);
981 close(fd);
982 }
983#endif /* TIOCNOTTY */
984 }
985 /* Reinitialize the log (because of the fork above). */
Kevin Stevesec84dc12000-12-13 17:45:15 +0000986 log_init(__progname, options.log_level, options.log_facility, log_stderr);
Damien Miller95def091999-11-25 00:26:21 +1100987
Damien Miller95def091999-11-25 00:26:21 +1100988 /* Initialize the random number generator. */
989 arc4random_stir();
990
991 /* Chdir to the root directory so that the current disk can be
992 unmounted if desired. */
993 chdir("/");
Damien Miller9f0f5c62001-12-21 14:45:46 +1100994
Ben Lindstromde71cda2001-03-24 00:43:26 +0000995 /* ignore SIGPIPE */
996 signal(SIGPIPE, SIG_IGN);
Damien Miller95def091999-11-25 00:26:21 +1100997
Damien Miller95def091999-11-25 00:26:21 +1100998 /* Start listening for a socket, unless started from inetd. */
999 if (inetd_flag) {
Ben Lindstrom206941f2001-04-15 14:27:16 +00001000 int s1;
Damien Miller95def091999-11-25 00:26:21 +11001001 s1 = dup(0); /* Make sure descriptors 0, 1, and 2 are in use. */
Ben Lindstrom206941f2001-04-15 14:27:16 +00001002 dup(s1);
Damien Miller95def091999-11-25 00:26:21 +11001003 sock_in = dup(0);
1004 sock_out = dup(1);
Damien Miller994cf142000-07-21 10:19:44 +10001005 startup_pipe = -1;
Damien Millereba71ba2000-04-29 23:57:08 +10001006 /*
1007 * We intentionally do not close the descriptors 0, 1, and 2
1008 * as our code for setting the descriptors won\'t work if
1009 * ttyfd happens to be one of those.
1010 */
Damien Miller95def091999-11-25 00:26:21 +11001011 debug("inetd sockets after dupping: %d, %d", sock_in, sock_out);
Damien Miller0bc1bd82000-11-13 22:57:25 +11001012 if (options.protocol & SSH_PROTO_1)
Ben Lindstromca42d5f2001-03-09 18:25:32 +00001013 generate_ephemeral_server_key();
Damien Miller95def091999-11-25 00:26:21 +11001014 } else {
Damien Miller34132e52000-01-14 15:45:46 +11001015 for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
1016 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1017 continue;
1018 if (num_listen_socks >= MAX_LISTEN_SOCKS)
1019 fatal("Too many listen sockets. "
1020 "Enlarge MAX_LISTEN_SOCKS");
1021 if (getnameinfo(ai->ai_addr, ai->ai_addrlen,
1022 ntop, sizeof(ntop), strport, sizeof(strport),
1023 NI_NUMERICHOST|NI_NUMERICSERV) != 0) {
1024 error("getnameinfo failed");
1025 continue;
1026 }
1027 /* Create socket for listening. */
1028 listen_sock = socket(ai->ai_family, SOCK_STREAM, 0);
1029 if (listen_sock < 0) {
1030 /* kernel may not support ipv6 */
1031 verbose("socket: %.100s", strerror(errno));
1032 continue;
1033 }
1034 if (fcntl(listen_sock, F_SETFL, O_NONBLOCK) < 0) {
1035 error("listen_sock O_NONBLOCK: %s", strerror(errno));
1036 close(listen_sock);
1037 continue;
1038 }
1039 /*
1040 * Set socket options. We try to make the port
1041 * reusable and have it close as fast as possible
1042 * without waiting in unnecessary wait states on
1043 * close.
1044 */
1045 setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
Ben Lindstrom733a2352002-03-05 01:31:28 +00001046 &on, sizeof(on));
Damien Miller34132e52000-01-14 15:45:46 +11001047 linger.l_onoff = 1;
1048 linger.l_linger = 5;
1049 setsockopt(listen_sock, SOL_SOCKET, SO_LINGER,
Ben Lindstrom733a2352002-03-05 01:31:28 +00001050 &linger, sizeof(linger));
Damien Miller95def091999-11-25 00:26:21 +11001051
Damien Miller34132e52000-01-14 15:45:46 +11001052 debug("Bind to port %s on %s.", strport, ntop);
Damien Miller95def091999-11-25 00:26:21 +11001053
Damien Miller34132e52000-01-14 15:45:46 +11001054 /* Bind the socket to the desired port. */
Damien Miller0a4e27d2001-02-18 12:36:39 +11001055 if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1056 if (!ai->ai_next)
1057 error("Bind to port %s on %s failed: %.200s.",
1058 strport, ntop, strerror(errno));
Damien Miller34132e52000-01-14 15:45:46 +11001059 close(listen_sock);
1060 continue;
1061 }
1062 listen_socks[num_listen_socks] = listen_sock;
1063 num_listen_socks++;
Damien Miller95def091999-11-25 00:26:21 +11001064
Damien Miller34132e52000-01-14 15:45:46 +11001065 /* Start listening on the port. */
1066 log("Server listening on %s port %s.", ntop, strport);
1067 if (listen(listen_sock, 5) < 0)
1068 fatal("listen: %.100s", strerror(errno));
1069
Damien Miller95def091999-11-25 00:26:21 +11001070 }
Damien Miller34132e52000-01-14 15:45:46 +11001071 freeaddrinfo(options.listen_addrs);
1072
1073 if (!num_listen_socks)
1074 fatal("Cannot bind any address.");
1075
Ben Lindstrom98097862001-06-25 05:10:20 +00001076 if (options.protocol & SSH_PROTO_1)
1077 generate_ephemeral_server_key();
1078
1079 /*
1080 * Arrange to restart on SIGHUP. The handler needs
1081 * listen_sock.
1082 */
1083 signal(SIGHUP, sighup_handler);
1084
1085 signal(SIGTERM, sigterm_handler);
1086 signal(SIGQUIT, sigterm_handler);
1087
1088 /* Arrange SIGCHLD to be caught. */
1089 signal(SIGCHLD, main_sigchld_handler);
1090
1091 /* Write out the pid file after the sigterm handler is setup */
Damien Miller95def091999-11-25 00:26:21 +11001092 if (!debug_flag) {
Damien Miller5428f641999-11-25 11:54:57 +11001093 /*
Ben Lindstrom7ad97102000-12-06 01:42:49 +00001094 * Record our pid in /var/run/sshd.pid to make it
1095 * easier to kill the correct sshd. We don't want to
1096 * do this before the bind above because the bind will
Damien Miller5428f641999-11-25 11:54:57 +11001097 * fail if there already is a daemon, and this will
1098 * overwrite any old pid in the file.
1099 */
Damien Millerbac2d8a2000-09-05 16:13:06 +11001100 f = fopen(options.pid_file, "wb");
Damien Miller95def091999-11-25 00:26:21 +11001101 if (f) {
Ben Lindstrom46c16222000-12-22 01:43:59 +00001102 fprintf(f, "%u\n", (u_int) getpid());
Damien Miller95def091999-11-25 00:26:21 +11001103 fclose(f);
1104 }
1105 }
Damien Miller95def091999-11-25 00:26:21 +11001106
Damien Miller34132e52000-01-14 15:45:46 +11001107 /* setup fd set for listen */
Damien Miller37023962000-07-11 17:31:38 +10001108 fdset = NULL;
Damien Miller34132e52000-01-14 15:45:46 +11001109 maxfd = 0;
1110 for (i = 0; i < num_listen_socks; i++)
1111 if (listen_socks[i] > maxfd)
1112 maxfd = listen_socks[i];
Damien Miller37023962000-07-11 17:31:38 +10001113 /* pipes connected to unauthenticated childs */
1114 startup_pipes = xmalloc(options.max_startups * sizeof(int));
1115 for (i = 0; i < options.max_startups; i++)
1116 startup_pipes[i] = -1;
Damien Miller34132e52000-01-14 15:45:46 +11001117
Damien Miller5428f641999-11-25 11:54:57 +11001118 /*
1119 * Stay listening for connections until the system crashes or
1120 * the daemon is killed with a signal.
1121 */
Damien Miller95def091999-11-25 00:26:21 +11001122 for (;;) {
1123 if (received_sighup)
1124 sighup_restart();
Damien Miller37023962000-07-11 17:31:38 +10001125 if (fdset != NULL)
1126 xfree(fdset);
Ben Lindstrombf555ba2001-01-18 02:04:35 +00001127 fdsetsz = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask);
Damien Miller37023962000-07-11 17:31:38 +10001128 fdset = (fd_set *)xmalloc(fdsetsz);
Damien Miller34132e52000-01-14 15:45:46 +11001129 memset(fdset, 0, fdsetsz);
Damien Miller37023962000-07-11 17:31:38 +10001130
Damien Miller34132e52000-01-14 15:45:46 +11001131 for (i = 0; i < num_listen_socks; i++)
1132 FD_SET(listen_socks[i], fdset);
Damien Miller37023962000-07-11 17:31:38 +10001133 for (i = 0; i < options.max_startups; i++)
1134 if (startup_pipes[i] != -1)
1135 FD_SET(startup_pipes[i], fdset);
1136
1137 /* Wait in select until there is a connection. */
Ben Lindstromdb65e8f2001-01-19 04:26:52 +00001138 ret = select(maxfd+1, fdset, NULL, NULL, NULL);
1139 if (ret < 0 && errno != EINTR)
1140 error("select: %.100s", strerror(errno));
Ben Lindstromec46e0b2001-06-09 01:27:31 +00001141 if (received_sigterm) {
1142 log("Received signal %d; terminating.",
Ben Lindstromf8f065b2001-12-06 17:52:16 +00001143 (int) received_sigterm);
Ben Lindstromec46e0b2001-06-09 01:27:31 +00001144 close_listen_socks();
1145 unlink(options.pid_file);
1146 exit(255);
1147 }
Ben Lindstromdb65e8f2001-01-19 04:26:52 +00001148 if (key_used && key_do_regen) {
Ben Lindstromca42d5f2001-03-09 18:25:32 +00001149 generate_ephemeral_server_key();
Ben Lindstromdb65e8f2001-01-19 04:26:52 +00001150 key_used = 0;
1151 key_do_regen = 0;
Damien Miller34132e52000-01-14 15:45:46 +11001152 }
Ben Lindstromdb65e8f2001-01-19 04:26:52 +00001153 if (ret < 0)
1154 continue;
1155
Damien Miller37023962000-07-11 17:31:38 +10001156 for (i = 0; i < options.max_startups; i++)
1157 if (startup_pipes[i] != -1 &&
1158 FD_ISSET(startup_pipes[i], fdset)) {
1159 /*
1160 * the read end of the pipe is ready
1161 * if the child has closed the pipe
Ben Lindstrom4dccfa52000-12-28 16:40:05 +00001162 * after successful authentication
Damien Miller37023962000-07-11 17:31:38 +10001163 * or if the child has died
1164 */
1165 close(startup_pipes[i]);
1166 startup_pipes[i] = -1;
1167 startups--;
1168 }
Damien Miller34132e52000-01-14 15:45:46 +11001169 for (i = 0; i < num_listen_socks; i++) {
1170 if (!FD_ISSET(listen_socks[i], fdset))
Damien Miller95def091999-11-25 00:26:21 +11001171 continue;
Damien Miller37023962000-07-11 17:31:38 +10001172 fromlen = sizeof(from);
1173 newsock = accept(listen_socks[i], (struct sockaddr *)&from,
1174 &fromlen);
1175 if (newsock < 0) {
1176 if (errno != EINTR && errno != EWOULDBLOCK)
1177 error("accept: %.100s", strerror(errno));
1178 continue;
1179 }
1180 if (fcntl(newsock, F_SETFL, 0) < 0) {
1181 error("newsock del O_NONBLOCK: %s", strerror(errno));
Damien Miller72c336d2001-12-21 12:44:28 +11001182 close(newsock);
Damien Miller37023962000-07-11 17:31:38 +10001183 continue;
1184 }
Damien Miller942da032000-08-18 13:59:06 +10001185 if (drop_connection(startups) == 1) {
1186 debug("drop connection #%d", startups);
Damien Miller37023962000-07-11 17:31:38 +10001187 close(newsock);
1188 continue;
1189 }
1190 if (pipe(startup_p) == -1) {
1191 close(newsock);
1192 continue;
1193 }
1194
1195 for (j = 0; j < options.max_startups; j++)
1196 if (startup_pipes[j] == -1) {
1197 startup_pipes[j] = startup_p[0];
1198 if (maxfd < startup_p[0])
1199 maxfd = startup_p[0];
1200 startups++;
1201 break;
1202 }
Kevin Stevesef4eea92001-02-05 12:42:17 +00001203
Damien Miller5428f641999-11-25 11:54:57 +11001204 /*
Damien Miller37023962000-07-11 17:31:38 +10001205 * Got connection. Fork a child to handle it, unless
1206 * we are in debugging mode.
Damien Miller5428f641999-11-25 11:54:57 +11001207 */
Damien Miller37023962000-07-11 17:31:38 +10001208 if (debug_flag) {
Damien Miller5428f641999-11-25 11:54:57 +11001209 /*
Damien Miller37023962000-07-11 17:31:38 +10001210 * In debugging mode. Close the listening
1211 * socket, and start processing the
1212 * connection without forking.
Damien Miller5428f641999-11-25 11:54:57 +11001213 */
Damien Miller37023962000-07-11 17:31:38 +10001214 debug("Server will not fork when running in debugging mode.");
Damien Miller34132e52000-01-14 15:45:46 +11001215 close_listen_socks();
Damien Miller95def091999-11-25 00:26:21 +11001216 sock_in = newsock;
1217 sock_out = newsock;
Damien Miller4d97ba22000-07-11 18:15:50 +10001218 startup_pipe = -1;
Damien Miller182ee6e2000-07-12 09:45:27 +10001219 pid = getpid();
Damien Miller95def091999-11-25 00:26:21 +11001220 break;
Damien Miller37023962000-07-11 17:31:38 +10001221 } else {
1222 /*
1223 * Normal production daemon. Fork, and have
1224 * the child process the connection. The
1225 * parent continues listening.
1226 */
1227 if ((pid = fork()) == 0) {
1228 /*
1229 * Child. Close the listening and max_startup
1230 * sockets. Start using the accepted socket.
1231 * Reinitialize logging (since our pid has
1232 * changed). We break out of the loop to handle
1233 * the connection.
1234 */
1235 startup_pipe = startup_p[1];
Ben Lindstromd84df982001-12-06 16:35:40 +00001236 close_startup_pipes();
Damien Miller37023962000-07-11 17:31:38 +10001237 close_listen_socks();
1238 sock_in = newsock;
1239 sock_out = newsock;
Kevin Stevesec84dc12000-12-13 17:45:15 +00001240 log_init(__progname, options.log_level, options.log_facility, log_stderr);
Damien Miller37023962000-07-11 17:31:38 +10001241 break;
1242 }
Damien Miller95def091999-11-25 00:26:21 +11001243 }
Damien Miller37023962000-07-11 17:31:38 +10001244
1245 /* Parent. Stay in the loop. */
1246 if (pid < 0)
1247 error("fork: %.100s", strerror(errno));
1248 else
1249 debug("Forked child %d.", pid);
1250
1251 close(startup_p[1]);
1252
1253 /* Mark that the key has been used (it was "given" to the child). */
Ben Lindstromdb65e8f2001-01-19 04:26:52 +00001254 if ((options.protocol & SSH_PROTO_1) &&
1255 key_used == 0) {
1256 /* Schedule server key regeneration alarm. */
1257 signal(SIGALRM, key_regeneration_alarm);
1258 alarm(options.key_regeneration_time);
1259 key_used = 1;
1260 }
Damien Miller37023962000-07-11 17:31:38 +10001261
1262 arc4random_stir();
1263
1264 /* Close the new socket (the child is now taking care of it). */
1265 close(newsock);
Damien Miller95def091999-11-25 00:26:21 +11001266 }
Damien Miller34132e52000-01-14 15:45:46 +11001267 /* child process check (or debug mode) */
1268 if (num_listen_socks < 0)
1269 break;
Damien Miller95def091999-11-25 00:26:21 +11001270 }
1271 }
1272
1273 /* This is the child processing a new connection. */
1274
Damien Miller5428f641999-11-25 11:54:57 +11001275 /*
1276 * Disable the key regeneration alarm. We will not regenerate the
1277 * key since we are no longer in a position to give it to anyone. We
1278 * will not restart on SIGHUP since it no longer makes sense.
1279 */
Damien Miller95def091999-11-25 00:26:21 +11001280 alarm(0);
1281 signal(SIGALRM, SIG_DFL);
1282 signal(SIGHUP, SIG_DFL);
1283 signal(SIGTERM, SIG_DFL);
1284 signal(SIGQUIT, SIG_DFL);
1285 signal(SIGCHLD, SIG_DFL);
Damien Miller4e0f5e12000-08-29 11:05:50 +11001286 signal(SIGINT, SIG_DFL);
Damien Miller95def091999-11-25 00:26:21 +11001287
Damien Miller5428f641999-11-25 11:54:57 +11001288 /*
1289 * Set socket options for the connection. We want the socket to
1290 * close as fast as possible without waiting for anything. If the
1291 * connection is not a socket, these will do nothing.
1292 */
1293 /* setsockopt(sock_in, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); */
Damien Miller95def091999-11-25 00:26:21 +11001294 linger.l_onoff = 1;
1295 linger.l_linger = 5;
Ben Lindstrom733a2352002-03-05 01:31:28 +00001296 setsockopt(sock_in, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger));
Damien Miller95def091999-11-25 00:26:21 +11001297
Ben Lindstrombf555ba2001-01-18 02:04:35 +00001298 /* Set keepalives if requested. */
1299 if (options.keepalives &&
Ben Lindstrom733a2352002-03-05 01:31:28 +00001300 setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on,
Ben Lindstrombf555ba2001-01-18 02:04:35 +00001301 sizeof(on)) < 0)
1302 error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1303
Damien Miller5428f641999-11-25 11:54:57 +11001304 /*
1305 * Register our connection. This turns encryption off because we do
1306 * not have a key.
1307 */
Damien Miller95def091999-11-25 00:26:21 +11001308 packet_set_connection(sock_in, sock_out);
1309
1310 remote_port = get_remote_port();
1311 remote_ip = get_remote_ipaddr();
1312
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001313#ifdef LIBWRAP
Damien Miller6a4a4b92001-11-12 11:07:11 +11001314 /* Check whether logins are denied from this host. */
Damien Miller95def091999-11-25 00:26:21 +11001315 {
1316 struct request_info req;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001317
Ben Lindstromce89dac2001-09-12 16:58:04 +00001318 request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0);
Damien Miller95def091999-11-25 00:26:21 +11001319 fromhost(&req);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001320
Damien Miller95def091999-11-25 00:26:21 +11001321 if (!hosts_access(&req)) {
Damien Miller6a4a4b92001-11-12 11:07:11 +11001322 debug("Connection refused by tcp wrapper");
Ben Lindstrom7de696e2001-03-29 00:45:12 +00001323 refuse(&req);
Damien Miller6a4a4b92001-11-12 11:07:11 +11001324 /* NOTREACHED */
1325 fatal("libwrap refuse returns");
Damien Miller95def091999-11-25 00:26:21 +11001326 }
Damien Miller95def091999-11-25 00:26:21 +11001327 }
Damien Miller34132e52000-01-14 15:45:46 +11001328#endif /* LIBWRAP */
Damien Miller6a4a4b92001-11-12 11:07:11 +11001329
Damien Miller95def091999-11-25 00:26:21 +11001330 /* Log the connection. */
1331 verbose("Connection from %.500s port %d", remote_ip, remote_port);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001332
Damien Miller5428f641999-11-25 11:54:57 +11001333 /*
1334 * We don\'t want to listen forever unless the other side
1335 * successfully authenticates itself. So we set up an alarm which is
1336 * cleared after successful authentication. A limit of zero
1337 * indicates no limit. Note that we don\'t set the alarm in debugging
1338 * mode; it is just annoying to have the server exit just when you
1339 * are about to discover the bug.
1340 */
Damien Miller95def091999-11-25 00:26:21 +11001341 signal(SIGALRM, grace_alarm_handler);
1342 if (!debug_flag)
1343 alarm(options.login_grace_time);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001344
Damien Millerb38eff82000-04-01 11:09:21 +10001345 sshd_exchange_identification(sock_in, sock_out);
Damien Miller5428f641999-11-25 11:54:57 +11001346 /*
Kevin Stevesfcec7f82000-12-15 19:55:48 +00001347 * Check that the connection comes from a privileged port.
1348 * Rhosts-Authentication only makes sense from priviledged
Damien Miller5428f641999-11-25 11:54:57 +11001349 * programs. Of course, if the intruder has root access on his local
1350 * machine, he can connect from any port. So do not use these
1351 * authentication methods from machines that you do not trust.
1352 */
Damien Miller654c03f2002-02-13 13:54:44 +11001353 if (options.rhosts_authentication &&
1354 (remote_port >= IPPORT_RESERVED ||
1355 remote_port < IPPORT_RESERVED / 2)) {
Kevin Stevesfcec7f82000-12-15 19:55:48 +00001356 debug("Rhosts Authentication disabled, "
Damien Miller00b61642001-11-12 10:51:23 +11001357 "originating port %d not trusted.", remote_port);
Damien Miller95def091999-11-25 00:26:21 +11001358 options.rhosts_authentication = 0;
Damien Miller95def091999-11-25 00:26:21 +11001359 }
Ben Lindstromec95ed92001-07-04 04:21:14 +00001360#if defined(KRB4) && !defined(KRB5)
Damien Miller34132e52000-01-14 15:45:46 +11001361 if (!packet_connection_is_ipv4() &&
1362 options.kerberos_authentication) {
1363 debug("Kerberos Authentication disabled, only available for IPv4.");
1364 options.kerberos_authentication = 0;
1365 }
Ben Lindstromec95ed92001-07-04 04:21:14 +00001366#endif /* KRB4 && !KRB5 */
Ben Lindstromf79aeff2001-02-10 21:27:11 +00001367#ifdef AFS
1368 /* If machine has AFS, set process authentication group. */
1369 if (k_hasafs()) {
1370 k_setpag();
1371 k_unlog();
1372 }
1373#endif /* AFS */
Damien Miller34132e52000-01-14 15:45:46 +11001374
Damien Miller95def091999-11-25 00:26:21 +11001375 packet_set_nonblocking();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001376
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00001377 if (!use_privsep)
1378 goto skip_privilegeseparation;
1379
1380 /* Set up unprivileged child process to deal with network data */
1381 monitor = monitor_init();
1382 /* Store a pointer to the kex for later rekeying */
1383 monitor->m_pkex = &xxx_kex;
1384
1385 pid = fork();
1386 if (pid == -1)
1387 fatal("fork of unprivileged child failed");
1388 else if (pid != 0) {
1389 debug2("Network child is on pid %d", pid);
1390
1391 close(monitor->m_recvfd);
1392 authctxt = monitor_child_preauth(monitor);
1393 close(monitor->m_sendfd);
1394
1395 /* Sync memory */
1396 monitor_sync(monitor);
1397 goto authenticated;
1398 } else {
1399 close(monitor->m_sendfd);
1400
1401 /* Demote the child */
1402 if (getuid() == 0 || geteuid() == 0)
1403 privsep_preauth_child();
1404 }
1405
1406 skip_privilegeseparation:
1407
Damien Miller396691a2000-01-20 22:44:08 +11001408 /* perform the key exchange */
Damien Miller396691a2000-01-20 22:44:08 +11001409 /* authenticate user and start session */
Damien Millerefb4afe2000-04-12 18:45:05 +10001410 if (compat20) {
1411 do_ssh2_kex();
Ben Lindstrom73ab9ba2002-03-22 01:27:35 +00001412 authctxt = do_authentication2();
Damien Millerefb4afe2000-04-12 18:45:05 +10001413 } else {
1414 do_ssh1_kex();
Ben Lindstrom73ab9ba2002-03-22 01:27:35 +00001415 authctxt = do_authentication();
Damien Millerefb4afe2000-04-12 18:45:05 +10001416 }
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00001417 if (use_privsep)
1418 mm_send_keystate(monitor);
1419
1420 /* If we use privilege separation, the unprivileged child exits */
1421 if (use_privsep)
1422 exit(0);
1423
1424 authenticated:
1425 /*
1426 * In privilege separation, we fork another child and prepare
1427 * file descriptor passing.
1428 */
1429 if (use_privsep) {
1430 privsep_postauth(authctxt, pid);
1431 if (!compat20)
1432 destroy_sensitive_data();
1433 }
Ben Lindstrom73ab9ba2002-03-22 01:27:35 +00001434
1435 /* Perform session preparation. */
1436 do_authenticated(authctxt);
1437
Damien Miller3a5b0232002-03-13 13:19:42 +11001438 /* The connection has been terminated. */
1439 verbose("Closing connection to %.100s", remote_ip);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001440
Damien Millerbeb4ba51999-12-28 15:09:35 +11001441#ifdef USE_PAM
Damien Millere72b7af1999-12-30 15:08:44 +11001442 finish_pam();
Damien Millerbeb4ba51999-12-28 15:09:35 +11001443#endif /* USE_PAM */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001444
Damien Miller95def091999-11-25 00:26:21 +11001445 packet_close();
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00001446
1447 if (use_privsep)
1448 mm_terminate();
1449
Damien Miller95def091999-11-25 00:26:21 +11001450 exit(0);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001451}
1452
Damien Miller95def091999-11-25 00:26:21 +11001453/*
Ben Lindstromabcb1452002-03-22 01:10:21 +00001454 * Decrypt session_key_int using our private server key and private host key
1455 * (key with larger modulus first).
1456 */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00001457int
Ben Lindstromabcb1452002-03-22 01:10:21 +00001458ssh1_session_key(BIGNUM *session_key_int)
1459{
1460 int rsafail = 0;
1461
1462 if (BN_cmp(sensitive_data.server_key->rsa->n, sensitive_data.ssh1_host_key->rsa->n) > 0) {
1463 /* Server key has bigger modulus. */
1464 if (BN_num_bits(sensitive_data.server_key->rsa->n) <
1465 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
1466 fatal("do_connection: %s: server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
1467 get_remote_ipaddr(),
1468 BN_num_bits(sensitive_data.server_key->rsa->n),
1469 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
1470 SSH_KEY_BITS_RESERVED);
1471 }
1472 if (rsa_private_decrypt(session_key_int, session_key_int,
1473 sensitive_data.server_key->rsa) <= 0)
1474 rsafail++;
1475 if (rsa_private_decrypt(session_key_int, session_key_int,
1476 sensitive_data.ssh1_host_key->rsa) <= 0)
1477 rsafail++;
1478 } else {
1479 /* Host key has bigger modulus (or they are equal). */
1480 if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) <
1481 BN_num_bits(sensitive_data.server_key->rsa->n) + SSH_KEY_BITS_RESERVED) {
1482 fatal("do_connection: %s: host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d",
1483 get_remote_ipaddr(),
1484 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
1485 BN_num_bits(sensitive_data.server_key->rsa->n),
1486 SSH_KEY_BITS_RESERVED);
1487 }
1488 if (rsa_private_decrypt(session_key_int, session_key_int,
1489 sensitive_data.ssh1_host_key->rsa) < 0)
1490 rsafail++;
1491 if (rsa_private_decrypt(session_key_int, session_key_int,
1492 sensitive_data.server_key->rsa) < 0)
1493 rsafail++;
1494 }
1495 return (rsafail);
1496}
1497/*
Damien Miller396691a2000-01-20 22:44:08 +11001498 * SSH1 key exchange
Damien Miller95def091999-11-25 00:26:21 +11001499 */
Ben Lindstrombba81212001-06-25 05:01:22 +00001500static void
Ben Lindstrom46c16222000-12-22 01:43:59 +00001501do_ssh1_kex(void)
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001502{
Damien Miller95def091999-11-25 00:26:21 +11001503 int i, len;
Damien Miller7650bc62001-01-30 09:27:26 +11001504 int rsafail = 0;
Damien Miller95def091999-11-25 00:26:21 +11001505 BIGNUM *session_key_int;
Ben Lindstrom46c16222000-12-22 01:43:59 +00001506 u_char session_key[SSH_SESSION_KEY_LENGTH];
1507 u_char cookie[8];
1508 u_int cipher_type, auth_mask, protocol_flags;
Damien Miller95def091999-11-25 00:26:21 +11001509 u_int32_t rand = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001510
Damien Miller5428f641999-11-25 11:54:57 +11001511 /*
1512 * Generate check bytes that the client must send back in the user
1513 * packet in order for it to be accepted; this is used to defy ip
1514 * spoofing attacks. Note that this only works against somebody
1515 * doing IP spoofing from a remote machine; any machine on the local
1516 * network can still see outgoing packets and catch the random
1517 * cookie. This only affects rhosts authentication, and this is one
1518 * of the reasons why it is inherently insecure.
1519 */
Damien Miller95def091999-11-25 00:26:21 +11001520 for (i = 0; i < 8; i++) {
1521 if (i % 4 == 0)
1522 rand = arc4random();
Damien Miller396691a2000-01-20 22:44:08 +11001523 cookie[i] = rand & 0xff;
Damien Miller95def091999-11-25 00:26:21 +11001524 rand >>= 8;
1525 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001526
Damien Miller5428f641999-11-25 11:54:57 +11001527 /*
1528 * Send our public key. We include in the packet 64 bits of random
1529 * data that must be matched in the reply in order to prevent IP
1530 * spoofing.
1531 */
Damien Miller95def091999-11-25 00:26:21 +11001532 packet_start(SSH_SMSG_PUBLIC_KEY);
1533 for (i = 0; i < 8; i++)
Damien Miller396691a2000-01-20 22:44:08 +11001534 packet_put_char(cookie[i]);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001535
Damien Miller95def091999-11-25 00:26:21 +11001536 /* Store our public server RSA key. */
Damien Miller0bc1bd82000-11-13 22:57:25 +11001537 packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n));
1538 packet_put_bignum(sensitive_data.server_key->rsa->e);
1539 packet_put_bignum(sensitive_data.server_key->rsa->n);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001540
Damien Miller95def091999-11-25 00:26:21 +11001541 /* Store our public host RSA key. */
Damien Miller0bc1bd82000-11-13 22:57:25 +11001542 packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
1543 packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e);
1544 packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001545
Damien Miller95def091999-11-25 00:26:21 +11001546 /* Put protocol flags. */
1547 packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001548
Damien Miller95def091999-11-25 00:26:21 +11001549 /* Declare which ciphers we support. */
Damien Miller874d77b2000-10-14 16:23:11 +11001550 packet_put_int(cipher_mask_ssh1(0));
Damien Miller95def091999-11-25 00:26:21 +11001551
1552 /* Declare supported authentication types. */
1553 auth_mask = 0;
1554 if (options.rhosts_authentication)
1555 auth_mask |= 1 << SSH_AUTH_RHOSTS;
1556 if (options.rhosts_rsa_authentication)
1557 auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA;
1558 if (options.rsa_authentication)
1559 auth_mask |= 1 << SSH_AUTH_RSA;
Ben Lindstromec95ed92001-07-04 04:21:14 +00001560#if defined(KRB4) || defined(KRB5)
Damien Miller95def091999-11-25 00:26:21 +11001561 if (options.kerberos_authentication)
1562 auth_mask |= 1 << SSH_AUTH_KERBEROS;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001563#endif
Ben Lindstromec95ed92001-07-04 04:21:14 +00001564#if defined(AFS) || defined(KRB5)
Damien Miller95def091999-11-25 00:26:21 +11001565 if (options.kerberos_tgt_passing)
1566 auth_mask |= 1 << SSH_PASS_KERBEROS_TGT;
Ben Lindstromec95ed92001-07-04 04:21:14 +00001567#endif
1568#ifdef AFS
Damien Miller95def091999-11-25 00:26:21 +11001569 if (options.afs_token_passing)
1570 auth_mask |= 1 << SSH_PASS_AFS_TOKEN;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001571#endif
Ben Lindstrom551ea372001-06-05 18:56:16 +00001572 if (options.challenge_response_authentication == 1)
Damien Miller95def091999-11-25 00:26:21 +11001573 auth_mask |= 1 << SSH_AUTH_TIS;
Damien Miller95def091999-11-25 00:26:21 +11001574 if (options.password_authentication)
1575 auth_mask |= 1 << SSH_AUTH_PASSWORD;
1576 packet_put_int(auth_mask);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001577
Damien Miller95def091999-11-25 00:26:21 +11001578 /* Send the packet and wait for it to be sent. */
1579 packet_send();
1580 packet_write_wait();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001581
Damien Miller0bc1bd82000-11-13 22:57:25 +11001582 debug("Sent %d bit server key and %d bit host key.",
1583 BN_num_bits(sensitive_data.server_key->rsa->n),
1584 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001585
Damien Miller95def091999-11-25 00:26:21 +11001586 /* Read clients reply (cipher type and session key). */
Damien Millerdff50992002-01-22 23:16:32 +11001587 packet_read_expect(SSH_CMSG_SESSION_KEY);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001588
Damien Miller50945fa1999-12-09 10:31:37 +11001589 /* Get cipher type and check whether we accept this. */
Damien Miller95def091999-11-25 00:26:21 +11001590 cipher_type = packet_get_char();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001591
Damien Miller874d77b2000-10-14 16:23:11 +11001592 if (!(cipher_mask_ssh1(0) & (1 << cipher_type)))
Damien Miller50945fa1999-12-09 10:31:37 +11001593 packet_disconnect("Warning: client selects unsupported cipher.");
1594
Damien Miller95def091999-11-25 00:26:21 +11001595 /* Get check bytes from the packet. These must match those we
1596 sent earlier with the public key packet. */
1597 for (i = 0; i < 8; i++)
Damien Miller396691a2000-01-20 22:44:08 +11001598 if (cookie[i] != packet_get_char())
Damien Miller95def091999-11-25 00:26:21 +11001599 packet_disconnect("IP Spoofing check bytes do not match.");
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001600
Damien Miller95def091999-11-25 00:26:21 +11001601 debug("Encryption type: %.200s", cipher_name(cipher_type));
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001602
Damien Miller95def091999-11-25 00:26:21 +11001603 /* Get the encrypted integer. */
Damien Millerda755162002-01-22 23:09:22 +11001604 if ((session_key_int = BN_new()) == NULL)
1605 fatal("do_ssh1_kex: BN_new failed");
Damien Millerd432ccf2002-01-22 23:14:44 +11001606 packet_get_bignum(session_key_int);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001607
Damien Miller95def091999-11-25 00:26:21 +11001608 protocol_flags = packet_get_int();
1609 packet_set_protocol_flags(protocol_flags);
Damien Miller48b03fc2002-01-22 23:11:40 +11001610 packet_check_eom();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001611
Ben Lindstromabcb1452002-03-22 01:10:21 +00001612 /* Decrypt session_key_int using host/server keys */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00001613 rsafail = PRIVSEP(ssh1_session_key(session_key_int));
1614
Damien Miller5428f641999-11-25 11:54:57 +11001615 /*
1616 * Extract session key from the decrypted integer. The key is in the
1617 * least significant 256 bits of the integer; the first byte of the
1618 * key is in the highest bits.
1619 */
Damien Miller7650bc62001-01-30 09:27:26 +11001620 if (!rsafail) {
1621 BN_mask_bits(session_key_int, sizeof(session_key) * 8);
1622 len = BN_num_bytes(session_key_int);
1623 if (len < 0 || len > sizeof(session_key)) {
1624 error("do_connection: bad session key len from %s: "
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001625 "session_key_int %d > sizeof(session_key) %lu",
1626 get_remote_ipaddr(), len, (u_long)sizeof(session_key));
Damien Miller7650bc62001-01-30 09:27:26 +11001627 rsafail++;
1628 } else {
1629 memset(session_key, 0, sizeof(session_key));
1630 BN_bn2bin(session_key_int,
1631 session_key + sizeof(session_key) - len);
Ben Lindstromeb648a72001-03-05 06:00:29 +00001632
1633 compute_session_id(session_id, cookie,
1634 sensitive_data.ssh1_host_key->rsa->n,
1635 sensitive_data.server_key->rsa->n);
1636 /*
1637 * Xor the first 16 bytes of the session key with the
1638 * session id.
1639 */
1640 for (i = 0; i < 16; i++)
1641 session_key[i] ^= session_id[i];
Damien Miller7650bc62001-01-30 09:27:26 +11001642 }
1643 }
1644 if (rsafail) {
Ben Lindstromeb648a72001-03-05 06:00:29 +00001645 int bytes = BN_num_bytes(session_key_int);
Ben Lindstrom13c5d3b2002-02-26 18:00:48 +00001646 u_char *buf = xmalloc(bytes);
Ben Lindstromeb648a72001-03-05 06:00:29 +00001647 MD5_CTX md;
1648
Damien Miller7650bc62001-01-30 09:27:26 +11001649 log("do_connection: generating a fake encryption key");
Ben Lindstromeb648a72001-03-05 06:00:29 +00001650 BN_bn2bin(session_key_int, buf);
1651 MD5_Init(&md);
1652 MD5_Update(&md, buf, bytes);
1653 MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
1654 MD5_Final(session_key, &md);
1655 MD5_Init(&md);
1656 MD5_Update(&md, session_key, 16);
1657 MD5_Update(&md, buf, bytes);
1658 MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
1659 MD5_Final(session_key + 16, &md);
1660 memset(buf, 0, bytes);
1661 xfree(buf);
Ben Lindstrom941ac822001-03-05 06:25:23 +00001662 for (i = 0; i < 16; i++)
1663 session_id[i] = session_key[i] ^ session_key[i + 16];
Damien Miller7650bc62001-01-30 09:27:26 +11001664 }
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00001665 /* Destroy the private and public keys. No longer. */
Damien Miller3a5b0232002-03-13 13:19:42 +11001666 destroy_sensitive_data();
Ben Lindstromeb648a72001-03-05 06:00:29 +00001667
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00001668 if (use_privsep)
1669 mm_ssh1_session_id(session_id);
1670
Damien Miller396691a2000-01-20 22:44:08 +11001671 /* Destroy the decrypted integer. It is no longer needed. */
1672 BN_clear_free(session_key_int);
1673
Damien Miller95def091999-11-25 00:26:21 +11001674 /* Set the session key. From this on all communications will be encrypted. */
1675 packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001676
Damien Miller95def091999-11-25 00:26:21 +11001677 /* Destroy our copy of the session key. It is no longer needed. */
1678 memset(session_key, 0, sizeof(session_key));
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001679
Damien Miller95def091999-11-25 00:26:21 +11001680 debug("Received session key; encryption turned on.");
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001681
Damien Miller95def091999-11-25 00:26:21 +11001682 /* Send an acknowledgement packet. Note that this packet is sent encrypted. */
1683 packet_start(SSH_SMSG_SUCCESS);
1684 packet_send();
1685 packet_write_wait();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001686}
Damien Millerefb4afe2000-04-12 18:45:05 +10001687
1688/*
1689 * SSH2 key exchange: diffie-hellman-group1-sha1
1690 */
Ben Lindstrombba81212001-06-25 05:01:22 +00001691static void
Ben Lindstrom46c16222000-12-22 01:43:59 +00001692do_ssh2_kex(void)
Damien Millerefb4afe2000-04-12 18:45:05 +10001693{
Damien Millerefb4afe2000-04-12 18:45:05 +10001694 Kex *kex;
Damien Millerefb4afe2000-04-12 18:45:05 +10001695
Damien Miller78928792000-04-12 20:17:38 +10001696 if (options.ciphers != NULL) {
Damien Miller4af51302000-04-16 11:18:38 +10001697 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
Damien Miller78928792000-04-12 20:17:38 +10001698 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
1699 }
Damien Millera0ff4662001-03-30 10:49:35 +10001700 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
1701 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
1702 myproposal[PROPOSAL_ENC_ALGS_STOC] =
1703 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
1704
Ben Lindstrom06b33aa2001-02-15 03:01:59 +00001705 if (options.macs != NULL) {
1706 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
1707 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
1708 }
Damien Miller0bc1bd82000-11-13 22:57:25 +11001709 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types();
1710
Ben Lindstrom8ac91062001-04-04 17:57:54 +00001711 /* start key exchange */
Ben Lindstrom238abf62001-04-04 17:52:53 +00001712 kex = kex_setup(myproposal);
Ben Lindstrom20d7c7b2001-04-04 01:56:17 +00001713 kex->server = 1;
1714 kex->client_version_string=client_version_string;
1715 kex->server_version_string=server_version_string;
1716 kex->load_host_key=&get_hostkey_by_type;
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00001717 kex->host_key_index=&get_hostkey_index;
Damien Millerefb4afe2000-04-12 18:45:05 +10001718
Ben Lindstrom8ac91062001-04-04 17:57:54 +00001719 xxx_kex = kex;
1720
Ben Lindstrombe2cc432001-04-04 23:46:07 +00001721 dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
Damien Miller874d77b2000-10-14 16:23:11 +11001722
Ben Lindstrom2d90e002001-04-04 02:00:54 +00001723 session_id2 = kex->session_id;
1724 session_id2_len = kex->session_id_len;
1725
Damien Miller874d77b2000-10-14 16:23:11 +11001726#ifdef DEBUG_KEXDH
1727 /* send 1st encrypted/maced/compressed message */
1728 packet_start(SSH2_MSG_IGNORE);
1729 packet_put_cstring("markus");
1730 packet_send();
1731 packet_write_wait();
1732#endif
Ben Lindstrom20d7c7b2001-04-04 01:56:17 +00001733 debug("KEX done");
Damien Millerefb4afe2000-04-12 18:45:05 +10001734}