blob: 799c7711f49c69c1d1b92544ace51a4bf57b6ef4 [file] [log] [blame]
dtucker@openbsd.org8c02e362016-05-24 04:43:45 +00001/* $OpenBSD: sshd.c,v 1.470 2016/05/24 04:43:45 dtucker Exp $ */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002/*
Damien Miller95def091999-11-25 00:26:21 +11003 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
5 * All rights reserved
Damien Millere4340be2000-09-16 13:29:08 +11006 * This program is the ssh daemon. It listens for connections from clients,
7 * and performs authentication, executes use commands or shell, and forwards
Damien Miller95def091999-11-25 00:26:21 +11008 * information to/from the application to the user client over an encrypted
Damien Millere4340be2000-09-16 13:29:08 +11009 * connection. This can also handle forwarding of X11, TCP/IP, and
10 * authentication agent connections.
Damien Millerefb4afe2000-04-12 18:45:05 +100011 *
Damien Millere4340be2000-09-16 13:29:08 +110012 * As far as I am concerned, the code I have written for this software
13 * can be used freely for any purpose. Any derived versions of this
14 * software must be clearly marked as such, and if the derived work is
15 * incompatible with the protocol description in the RFC file, it must be
16 * called by a name other than "ssh" or "Secure Shell".
17 *
18 * SSH2 implementation:
Ben Lindstrom7a2073c2002-03-22 02:30:41 +000019 * Privilege Separation:
Damien Millere4340be2000-09-16 13:29:08 +110020 *
Ben Lindstrom7a2073c2002-03-22 02:30:41 +000021 * Copyright (c) 2000, 2001, 2002 Markus Friedl. All rights reserved.
22 * Copyright (c) 2002 Niels Provos. All rights reserved.
Damien Millere4340be2000-09-16 13:29:08 +110023 *
24 * Redistribution and use in source and binary forms, with or without
25 * modification, are permitted provided that the following conditions
26 * are met:
27 * 1. Redistributions of source code must retain the above copyright
28 * notice, this list of conditions and the following disclaimer.
29 * 2. Redistributions in binary form must reproduce the above copyright
30 * notice, this list of conditions and the following disclaimer in the
31 * documentation and/or other materials provided with the distribution.
32 *
33 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
34 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
35 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
36 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
37 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
38 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
39 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
40 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
41 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
42 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
Damien Miller95def091999-11-25 00:26:21 +110043 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100044
45#include "includes.h"
Damien Miller17e91c02006-03-15 11:28:34 +110046
Damien Miller9cf6d072006-03-15 11:29:24 +110047#include <sys/types.h>
Damien Millerd7834352006-08-05 12:39:39 +100048#include <sys/ioctl.h>
49#include <sys/socket.h>
Damien Millerf17883e2006-03-15 11:45:54 +110050#ifdef HAVE_SYS_STAT_H
51# include <sys/stat.h>
52#endif
Damien Miller9aec9192006-08-05 10:57:45 +100053#ifdef HAVE_SYS_TIME_H
54# include <sys/time.h>
55#endif
Damien Millerd7834352006-08-05 12:39:39 +100056#include "openbsd-compat/sys-tree.h"
Damien Millerb84886b2008-05-19 15:05:07 +100057#include "openbsd-compat/sys-queue.h"
Damien Miller9cf6d072006-03-15 11:29:24 +110058#include <sys/wait.h>
Damien Miller03e20032006-03-15 11:16:59 +110059
Darren Tucker39972492006-07-12 22:22:46 +100060#include <errno.h>
Damien Miller57cf6382006-07-10 21:13:46 +100061#include <fcntl.h>
Damien Millerb8fe89c2006-07-24 14:51:00 +100062#include <netdb.h>
Damien Miller6645e7a2006-03-15 14:42:54 +110063#ifdef HAVE_PATHS_H
Damien Miller03e20032006-03-15 11:16:59 +110064#include <paths.h>
Damien Miller6645e7a2006-03-15 14:42:54 +110065#endif
Damien Millera1738e42006-07-10 21:33:04 +100066#include <grp.h>
Damien Miller9f2abc42006-07-10 20:53:08 +100067#include <pwd.h>
Damien Miller6ff3cad2006-03-15 11:52:09 +110068#include <signal.h>
Damien Millerded319c2006-09-01 15:38:36 +100069#include <stdarg.h>
Damien Millera7a73ee2006-08-05 11:37:59 +100070#include <stdio.h>
Damien Millere7a1e5c2006-08-05 11:34:19 +100071#include <stdlib.h>
Damien Millere3476ed2006-07-24 14:13:33 +100072#include <string.h>
Damien Miller75bb6642006-08-05 14:07:20 +100073#include <unistd.h>
deraadt@openbsd.org087266e2015-01-20 23:14:00 +000074#include <limits.h>
Damien Millerd4a8b7e1999-10-27 13:42:43 +100075
Damien Miller1f0311c2014-05-15 14:24:09 +100076#ifdef WITH_OPENSSL
Ben Lindstrom226cfa02001-01-22 05:34:40 +000077#include <openssl/dh.h>
78#include <openssl/bn.h>
Ben Lindstrom7a2073c2002-03-22 02:30:41 +000079#include <openssl/rand.h>
Darren Tuckerbfaaf962008-02-28 19:13:52 +110080#include "openbsd-compat/openssl-compat.h"
Damien Miller1f0311c2014-05-15 14:24:09 +100081#endif
Darren Tuckerbfaaf962008-02-28 19:13:52 +110082
Kevin Steves0ea1d9d2002-04-25 18:17:04 +000083#ifdef HAVE_SECUREWARE
84#include <sys/security.h>
85#include <prot.h>
86#endif
Ben Lindstrom226cfa02001-01-22 05:34:40 +000087
Damien Millerd7834352006-08-05 12:39:39 +100088#include "xmalloc.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000089#include "ssh.h"
90#include "ssh1.h"
91#include "ssh2.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100092#include "rsa.h"
Ben Lindstromd95c09c2001-02-18 19:13:33 +000093#include "sshpty.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100094#include "packet.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000095#include "log.h"
Damien Millerd7834352006-08-05 12:39:39 +100096#include "buffer.h"
Damien Miller7acefbb2014-07-18 14:11:24 +100097#include "misc.h"
markus@openbsd.org3a1638d2015-07-10 06:21:53 +000098#include "match.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100099#include "servconf.h"
100#include "uidswap.h"
101#include "compat.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +0000102#include "cipher.h"
Damien Miller4a1c7aa2014-02-04 11:03:36 +1100103#include "digest.h"
Damien Millerb38eff82000-04-01 11:09:21 +1000104#include "key.h"
Damien Millerd7834352006-08-05 12:39:39 +1000105#include "kex.h"
Damien Millerefb4afe2000-04-12 18:45:05 +1000106#include "myproposal.h"
Damien Millereba71ba2000-04-29 23:57:08 +1000107#include "authfile.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +0000108#include "pathnames.h"
109#include "atomicio.h"
110#include "canohost.h"
Damien Millerd7834352006-08-05 12:39:39 +1000111#include "hostfile.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +0000112#include "auth.h"
Damien Miller85b45e02013-07-20 13:21:52 +1000113#include "authfd.h"
Darren Tucker645ab752004-06-25 13:33:20 +1000114#include "msg.h"
Ben Lindstrom20d7c7b2001-04-04 01:56:17 +0000115#include "dispatch.h"
Ben Lindstrom1bae4042001-10-03 17:46:39 +0000116#include "channels.h"
Ben Lindstrom73ab9ba2002-03-22 01:27:35 +0000117#include "session.h"
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000118#include "monitor_mm.h"
119#include "monitor.h"
Damien Millerd7834352006-08-05 12:39:39 +1000120#ifdef GSSAPI
121#include "ssh-gss.h"
122#endif
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000123#include "monitor_wrap.h"
Damien Millerdcbd41e2011-06-23 19:45:51 +1000124#include "ssh-sandbox.h"
Damien Millerb7576772006-07-10 20:23:39 +1000125#include "version.h"
djm@openbsd.org141efe42015-01-14 20:05:27 +0000126#include "ssherr.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000127
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000128#ifndef O_NOCTTY
129#define O_NOCTTY 0
130#endif
131
Damien Miller035a5b42004-06-26 08:16:31 +1000132/* Re-exec fds */
133#define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1)
134#define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2)
135#define REEXEC_CONFIG_PASS_FD (STDERR_FILENO + 3)
136#define REEXEC_MIN_FREE_FD (STDERR_FILENO + 4)
137
Ben Lindstrom49a79c02000-11-17 03:47:20 +0000138extern char *__progname;
Ben Lindstrom49a79c02000-11-17 03:47:20 +0000139
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000140/* Server configuration options. */
141ServerOptions options;
142
143/* Name of the server configuration file. */
Ben Lindstrom226cfa02001-01-22 05:34:40 +0000144char *config_file_name = _PATH_SERVER_CONFIG_FILE;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000145
Damien Miller4af51302000-04-16 11:18:38 +1000146/*
Damien Miller95def091999-11-25 00:26:21 +1100147 * Debug mode flag. This can be set on the command line. If debug
148 * mode is enabled, extra debugging output will be sent to the system
149 * log, the daemon will not go to background, and will exit after processing
150 * the first connection.
151 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000152int debug_flag = 0;
153
Ben Lindstrom794325a2001-08-06 21:09:07 +0000154/* Flag indicating that the daemon should only test the configuration and keys. */
155int test_flag = 0;
156
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000157/* Flag indicating that the daemon is being started from inetd. */
158int inetd_flag = 0;
159
Ben Lindstromc72745a2000-12-02 19:03:54 +0000160/* Flag indicating that sshd should not detach and become a daemon. */
161int no_daemon_flag = 0;
162
Damien Miller5ce662a1999-11-11 17:57:39 +1100163/* debug goes to stderr unless inetd_flag is set */
164int log_stderr = 0;
165
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000166/* Saved arguments to main(). */
167char **saved_argv;
Damien Millerb8c656e2000-06-28 15:22:41 +1000168int saved_argc;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000169
Darren Tucker645ab752004-06-25 13:33:20 +1000170/* re-exec */
171int rexeced_flag = 0;
172int rexec_flag = 1;
173int rexec_argc = 0;
174char **rexec_argv;
175
Damien Miller5428f641999-11-25 11:54:57 +1100176/*
Damien Miller34132e52000-01-14 15:45:46 +1100177 * The sockets that the server is listening; this is used in the SIGHUP
178 * signal handler.
Damien Miller5428f641999-11-25 11:54:57 +1100179 */
Damien Miller34132e52000-01-14 15:45:46 +1100180#define MAX_LISTEN_SOCKS 16
181int listen_socks[MAX_LISTEN_SOCKS];
182int num_listen_socks = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000183
Damien Miller5428f641999-11-25 11:54:57 +1100184/*
185 * the client's version string, passed by sshd2 in compat mode. if != NULL,
186 * sshd will skip the version-number exchange
187 */
Damien Miller95def091999-11-25 00:26:21 +1100188char *client_version_string = NULL;
Damien Millerb38eff82000-04-01 11:09:21 +1000189char *server_version_string = NULL;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000190
Damien Miller85b45e02013-07-20 13:21:52 +1000191/* Daemon's agent connection */
djm@openbsd.org141efe42015-01-14 20:05:27 +0000192int auth_sock = -1;
Damien Miller85b45e02013-07-20 13:21:52 +1000193int have_agent = 0;
194
Damien Miller5428f641999-11-25 11:54:57 +1100195/*
196 * Any really sensitive data in the application is contained in this
197 * structure. The idea is that this structure could be locked into memory so
198 * that the pages do not get written into swap. However, there are some
199 * problems. The private key contains BIGNUMs, and we do not (in principle)
200 * have access to the internals of them, and locking just the structure is
201 * not very useful. Currently, memory locking is not implemented.
202 */
Damien Miller95def091999-11-25 00:26:21 +1100203struct {
Ben Lindstromca42d5f2001-03-09 18:25:32 +0000204 Key *server_key; /* ephemeral server key */
Damien Miller0bc1bd82000-11-13 22:57:25 +1100205 Key *ssh1_host_key; /* ssh1 host key */
206 Key **host_keys; /* all private host keys */
Damien Miller85b45e02013-07-20 13:21:52 +1000207 Key **host_pubkeys; /* all public host keys */
Damien Miller0a80ca12010-02-27 07:55:05 +1100208 Key **host_certificates; /* all public host certificates */
Damien Miller0bc1bd82000-11-13 22:57:25 +1100209 int have_ssh1_key;
210 int have_ssh2_key;
Ben Lindstromeb648a72001-03-05 06:00:29 +0000211 u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH];
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000212} sensitive_data;
213
Damien Miller5428f641999-11-25 11:54:57 +1100214/*
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000215 * Flag indicating whether the RSA server key needs to be regenerated.
216 * Is set in the SIGALRM handler and cleared when the key is regenerated.
Damien Miller5428f641999-11-25 11:54:57 +1100217 */
Ben Lindstrom5e71c542001-12-06 16:48:14 +0000218static volatile sig_atomic_t key_do_regen = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000219
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000220/* This is set to true when a signal is received. */
Ben Lindstrom5e71c542001-12-06 16:48:14 +0000221static volatile sig_atomic_t received_sighup = 0;
222static volatile sig_atomic_t received_sigterm = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000223
Damien Millerb38eff82000-04-01 11:09:21 +1000224/* session identifier, used by RSA-auth */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000225u_char session_id[16];
Damien Millerb38eff82000-04-01 11:09:21 +1000226
Damien Millereba71ba2000-04-29 23:57:08 +1000227/* same for ssh2 */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000228u_char *session_id2 = NULL;
Darren Tucker502d3842003-06-28 12:38:01 +1000229u_int session_id2_len = 0;
Damien Millereba71ba2000-04-29 23:57:08 +1000230
Damien Miller942da032000-08-18 13:59:06 +1000231/* record remote hostname or ip */
deraadt@openbsd.org087266e2015-01-20 23:14:00 +0000232u_int utmp_len = HOST_NAME_MAX+1;
Damien Miller942da032000-08-18 13:59:06 +1000233
Ben Lindstromd84df982001-12-06 16:35:40 +0000234/* options.max_startup sized array of fd ints */
235int *startup_pipes = NULL;
236int startup_pipe; /* in child */
237
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000238/* variables used for privilege separation */
Darren Tucker45150472006-07-12 22:34:17 +1000239int use_privsep = -1;
Darren Tuckera8be9e22004-02-06 16:40:27 +1100240struct monitor *pmonitor = NULL;
Damien Miller9ee2c602011-09-22 21:38:30 +1000241int privsep_is_preauth = 1;
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000242
Darren Tucker3e33cec2003-10-02 16:12:36 +1000243/* global authentication context */
244Authctxt *the_authctxt = NULL;
245
Darren Tucker45150472006-07-12 22:34:17 +1000246/* sshd_config buffer */
247Buffer cfg;
248
Darren Tucker09991742004-07-17 17:05:14 +1000249/* message to be displayed after login */
250Buffer loginmsg;
251
Damien Miller6433df02006-09-07 10:36:43 +1000252/* Unprivileged user */
253struct passwd *privsep_pw = NULL;
254
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000255/* Prototypes for various functions defined later in this file. */
Ben Lindstrombba81212001-06-25 05:01:22 +0000256void destroy_sensitive_data(void);
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000257void demote_sensitive_data(void);
Damien Miller98c7ad62000-03-09 21:27:49 +1100258
Damien Miller1f0311c2014-05-15 14:24:09 +1000259#ifdef WITH_SSH1
Ben Lindstrombba81212001-06-25 05:01:22 +0000260static void do_ssh1_kex(void);
Damien Miller1f0311c2014-05-15 14:24:09 +1000261#endif
Ben Lindstrombba81212001-06-25 05:01:22 +0000262static void do_ssh2_kex(void);
Damien Miller874d77b2000-10-14 16:23:11 +1100263
Damien Miller98c7ad62000-03-09 21:27:49 +1100264/*
Damien Miller34132e52000-01-14 15:45:46 +1100265 * Close all listening sockets
266 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000267static void
Damien Miller34132e52000-01-14 15:45:46 +1100268close_listen_socks(void)
269{
270 int i;
Ben Lindstrom822b6342002-06-23 21:38:49 +0000271
Damien Miller34132e52000-01-14 15:45:46 +1100272 for (i = 0; i < num_listen_socks; i++)
273 close(listen_socks[i]);
274 num_listen_socks = -1;
275}
276
Ben Lindstromd84df982001-12-06 16:35:40 +0000277static void
278close_startup_pipes(void)
279{
280 int i;
Ben Lindstrom822b6342002-06-23 21:38:49 +0000281
Ben Lindstromd84df982001-12-06 16:35:40 +0000282 if (startup_pipes)
283 for (i = 0; i < options.max_startups; i++)
284 if (startup_pipes[i] != -1)
285 close(startup_pipes[i]);
286}
287
Damien Miller34132e52000-01-14 15:45:46 +1100288/*
Damien Miller95def091999-11-25 00:26:21 +1100289 * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP;
290 * the effect is to reread the configuration file (and to regenerate
291 * the server key).
292 */
Damien Millerf0b15df2006-03-26 13:59:20 +1100293
294/*ARGSUSED*/
Ben Lindstrombba81212001-06-25 05:01:22 +0000295static void
Damien Miller95def091999-11-25 00:26:21 +1100296sighup_handler(int sig)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000297{
Ben Lindstrom07958482001-12-06 16:19:01 +0000298 int save_errno = errno;
299
Damien Miller95def091999-11-25 00:26:21 +1100300 received_sighup = 1;
301 signal(SIGHUP, sighup_handler);
Ben Lindstrom07958482001-12-06 16:19:01 +0000302 errno = save_errno;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000303}
304
Damien Miller95def091999-11-25 00:26:21 +1100305/*
306 * Called from the main program after receiving SIGHUP.
307 * Restarts the server.
308 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000309static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000310sighup_restart(void)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000311{
Damien Miller996acd22003-04-09 20:59:48 +1000312 logit("Received SIGHUP; restarting.");
Darren Tuckerf2bf36c2013-09-22 19:02:40 +1000313 platform_pre_restart();
Damien Miller34132e52000-01-14 15:45:46 +1100314 close_listen_socks();
Ben Lindstromd84df982001-12-06 16:35:40 +0000315 close_startup_pipes();
Darren Tuckered623962007-02-25 20:37:21 +1100316 alarm(0); /* alarm timer persists across exec */
Darren Tucker2c671bf2010-01-09 22:28:43 +1100317 signal(SIGHUP, SIG_IGN); /* will be restored after exec */
Damien Miller95def091999-11-25 00:26:21 +1100318 execv(saved_argv[0], saved_argv);
Damien Miller996acd22003-04-09 20:59:48 +1000319 logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0],
Ben Lindstrom822b6342002-06-23 21:38:49 +0000320 strerror(errno));
Damien Miller95def091999-11-25 00:26:21 +1100321 exit(1);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000322}
323
Damien Miller95def091999-11-25 00:26:21 +1100324/*
325 * Generic signal handler for terminating signals in the master daemon.
Damien Miller95def091999-11-25 00:26:21 +1100326 */
Damien Millerf0b15df2006-03-26 13:59:20 +1100327/*ARGSUSED*/
Ben Lindstrombba81212001-06-25 05:01:22 +0000328static void
Damien Miller95def091999-11-25 00:26:21 +1100329sigterm_handler(int sig)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000330{
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000331 received_sigterm = sig;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000332}
333
Damien Miller95def091999-11-25 00:26:21 +1100334/*
335 * SIGCHLD handler. This is called whenever a child dies. This will then
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000336 * reap any zombies left by exited children.
Damien Miller95def091999-11-25 00:26:21 +1100337 */
Damien Millerf0b15df2006-03-26 13:59:20 +1100338/*ARGSUSED*/
Ben Lindstrombba81212001-06-25 05:01:22 +0000339static void
Damien Miller95def091999-11-25 00:26:21 +1100340main_sigchld_handler(int sig)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000341{
Damien Miller95def091999-11-25 00:26:21 +1100342 int save_errno = errno;
Ben Lindstrom822b6342002-06-23 21:38:49 +0000343 pid_t pid;
Damien Miller95def091999-11-25 00:26:21 +1100344 int status;
Damien Miller431f66b1999-11-21 18:31:57 +1100345
Ben Lindstrom47fd8112002-04-02 20:48:19 +0000346 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
347 (pid < 0 && errno == EINTR))
Damien Miller95def091999-11-25 00:26:21 +1100348 ;
Damien Miller431f66b1999-11-21 18:31:57 +1100349
Damien Miller95def091999-11-25 00:26:21 +1100350 signal(SIGCHLD, main_sigchld_handler);
351 errno = save_errno;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000352}
353
Damien Miller95def091999-11-25 00:26:21 +1100354/*
355 * Signal handler for the alarm after the login grace period has expired.
356 */
Damien Millerf0b15df2006-03-26 13:59:20 +1100357/*ARGSUSED*/
Ben Lindstrombba81212001-06-25 05:01:22 +0000358static void
Damien Miller95def091999-11-25 00:26:21 +1100359grace_alarm_handler(int sig)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000360{
Darren Tuckera8be9e22004-02-06 16:40:27 +1100361 if (use_privsep && pmonitor != NULL && pmonitor->m_pid > 0)
362 kill(pmonitor->m_pid, SIGALRM);
363
Damien Miller09d3e122012-10-31 08:58:58 +1100364 /*
365 * Try to kill any processes that we have spawned, E.g. authorized
366 * keys command helpers.
367 */
368 if (getpgid(0) == getpid()) {
369 signal(SIGTERM, SIG_IGN);
Damien Millerab16ef42014-01-28 15:08:12 +1100370 kill(0, SIGTERM);
Damien Miller09d3e122012-10-31 08:58:58 +1100371 }
372
Damien Miller95def091999-11-25 00:26:21 +1100373 /* Log error and exit. */
djm@openbsd.org95767262016-03-07 19:02:43 +0000374 sigdie("Timeout before authentication for %s port %d",
375 ssh_remote_ipaddr(active_state), ssh_remote_port(active_state));
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000376}
377
Damien Miller95def091999-11-25 00:26:21 +1100378/*
Damien Miller95def091999-11-25 00:26:21 +1100379 * Signal handler for the key regeneration alarm. Note that this
380 * alarm only occurs in the daemon waiting for connections, and it does not
381 * do anything with the private key or random state before forking.
382 * Thus there should be no concurrency control/asynchronous execution
383 * problems.
384 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000385static void
Ben Lindstromca42d5f2001-03-09 18:25:32 +0000386generate_ephemeral_server_key(void)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100387{
Ben Lindstroma3700052001-04-05 23:26:32 +0000388 verbose("Generating %s%d bit RSA key.",
Damien Millerff75ac42001-03-30 10:50:32 +1000389 sensitive_data.server_key ? "new " : "", options.server_key_bits);
Damien Miller0bc1bd82000-11-13 22:57:25 +1100390 if (sensitive_data.server_key != NULL)
391 key_free(sensitive_data.server_key);
Ben Lindstroma3700052001-04-05 23:26:32 +0000392 sensitive_data.server_key = key_generate(KEY_RSA1,
Damien Millerff75ac42001-03-30 10:50:32 +1000393 options.server_key_bits);
394 verbose("RSA key generation complete.");
Ben Lindstromeb648a72001-03-05 06:00:29 +0000395
Damien Miller354c48c2008-05-19 14:50:00 +1000396 arc4random_buf(sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
Damien Miller0bc1bd82000-11-13 22:57:25 +1100397}
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000398
Damien Millerf0b15df2006-03-26 13:59:20 +1100399/*ARGSUSED*/
Ben Lindstrombba81212001-06-25 05:01:22 +0000400static void
Damien Miller95def091999-11-25 00:26:21 +1100401key_regeneration_alarm(int sig)
402{
403 int save_errno = errno;
Ben Lindstrom822b6342002-06-23 21:38:49 +0000404
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000405 signal(SIGALRM, SIG_DFL);
Damien Miller95def091999-11-25 00:26:21 +1100406 errno = save_errno;
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000407 key_do_regen = 1;
Damien Miller95def091999-11-25 00:26:21 +1100408}
409
Ben Lindstrombba81212001-06-25 05:01:22 +0000410static void
djm@openbsd.org95767262016-03-07 19:02:43 +0000411sshd_exchange_identification(struct ssh *ssh, int sock_in, int sock_out)
Damien Millerb38eff82000-04-01 11:09:21 +1000412{
Damien Millereccb9de2005-06-17 12:59:34 +1000413 u_int i;
414 int mismatch;
Damien Millerb38eff82000-04-01 11:09:21 +1000415 int remote_major, remote_minor;
Damien Miller78928792000-04-12 20:17:38 +1000416 int major, minor;
Darren Tuckerd7bdc0c2008-07-02 22:34:30 +1000417 char *s, *newline = "\n";
Damien Millerb38eff82000-04-01 11:09:21 +1000418 char buf[256]; /* Must not be larger than remote_version. */
419 char remote_version[256]; /* Must be at least as big as buf. */
420
Damien Miller78928792000-04-12 20:17:38 +1000421 if ((options.protocol & SSH_PROTO_1) &&
422 (options.protocol & SSH_PROTO_2)) {
423 major = PROTOCOL_MAJOR_1;
424 minor = 99;
425 } else if (options.protocol & SSH_PROTO_2) {
426 major = PROTOCOL_MAJOR_2;
427 minor = PROTOCOL_MINOR_2;
Darren Tuckerd7bdc0c2008-07-02 22:34:30 +1000428 newline = "\r\n";
Damien Miller78928792000-04-12 20:17:38 +1000429 } else {
430 major = PROTOCOL_MAJOR_1;
431 minor = PROTOCOL_MINOR_1;
432 }
Damien Miller23528812012-04-22 11:24:43 +1000433
434 xasprintf(&server_version_string, "SSH-%d.%d-%.100s%s%s%s",
435 major, minor, SSH_VERSION,
436 *options.version_addendum == '\0' ? "" : " ",
437 options.version_addendum, newline);
Damien Millerb38eff82000-04-01 11:09:21 +1000438
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000439 /* Send our protocol version identification. */
markus@openbsd.orga3068632016-01-14 16:17:39 +0000440 if (atomicio(vwrite, sock_out, server_version_string,
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000441 strlen(server_version_string))
442 != strlen(server_version_string)) {
djm@openbsd.org95767262016-03-07 19:02:43 +0000443 logit("Could not write ident string to %s port %d",
444 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
Darren Tucker3e33cec2003-10-02 16:12:36 +1000445 cleanup_exit(255);
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000446 }
447
448 /* Read other sides version identification. */
449 memset(buf, 0, sizeof(buf));
450 for (i = 0; i < sizeof(buf) - 1; i++) {
markus@openbsd.orga3068632016-01-14 16:17:39 +0000451 if (atomicio(read, sock_in, &buf[i], 1) != 1) {
djm@openbsd.org95767262016-03-07 19:02:43 +0000452 logit("Did not receive identification string "
453 "from %s port %d",
454 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
Darren Tucker3e33cec2003-10-02 16:12:36 +1000455 cleanup_exit(255);
Damien Millerb38eff82000-04-01 11:09:21 +1000456 }
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000457 if (buf[i] == '\r') {
458 buf[i] = 0;
459 /* Kludge for F-Secure Macintosh < 1.0.2 */
460 if (i == 12 &&
461 strncmp(buf, "SSH-1.5-W1.0", 12) == 0)
Damien Millerb38eff82000-04-01 11:09:21 +1000462 break;
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000463 continue;
Damien Millerb38eff82000-04-01 11:09:21 +1000464 }
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000465 if (buf[i] == '\n') {
466 buf[i] = 0;
467 break;
468 }
Damien Millerb38eff82000-04-01 11:09:21 +1000469 }
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000470 buf[sizeof(buf) - 1] = 0;
471 client_version_string = xstrdup(buf);
Damien Millerb38eff82000-04-01 11:09:21 +1000472
473 /*
474 * Check that the versions match. In future this might accept
475 * several versions and set appropriate flags to handle them.
476 */
477 if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n",
478 &remote_major, &remote_minor, remote_version) != 3) {
Damien Miller4af51302000-04-16 11:18:38 +1000479 s = "Protocol mismatch.\n";
Darren Tucker9f63f222003-07-03 13:46:56 +1000480 (void) atomicio(vwrite, sock_out, s, strlen(s));
Damien Miller4502f882013-10-18 10:17:36 +1100481 logit("Bad protocol version identification '%.100s' "
482 "from %s port %d", client_version_string,
djm@openbsd.org95767262016-03-07 19:02:43 +0000483 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
Damien Miller23e00aa2013-11-21 13:56:28 +1100484 close(sock_in);
485 close(sock_out);
Darren Tucker3e33cec2003-10-02 16:12:36 +1000486 cleanup_exit(255);
Damien Millerb38eff82000-04-01 11:09:21 +1000487 }
488 debug("Client protocol version %d.%d; client software version %.100s",
Damien Miller9f0f5c62001-12-21 14:45:46 +1100489 remote_major, remote_minor, remote_version);
Damien Millerb38eff82000-04-01 11:09:21 +1000490
djm@openbsd.org95767262016-03-07 19:02:43 +0000491 ssh->compat = compat_datafellows(remote_version);
Damien Millerefb4afe2000-04-12 18:45:05 +1000492
djm@openbsd.org95767262016-03-07 19:02:43 +0000493 if ((ssh->compat & SSH_BUG_PROBE) != 0) {
494 logit("probed from %s port %d with %s. Don't panic.",
495 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
496 client_version_string);
Darren Tucker3e33cec2003-10-02 16:12:36 +1000497 cleanup_exit(255);
Damien Millere9264972002-09-30 11:59:21 +1000498 }
djm@openbsd.org95767262016-03-07 19:02:43 +0000499 if ((ssh->compat & SSH_BUG_SCANNER) != 0) {
500 logit("scanned from %s port %d with %s. Don't panic.",
501 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
502 client_version_string);
Darren Tucker3e33cec2003-10-02 16:12:36 +1000503 cleanup_exit(255);
Damien Miller27dbe6f2001-03-19 22:36:20 +1100504 }
djm@openbsd.org95767262016-03-07 19:02:43 +0000505 if ((ssh->compat & SSH_BUG_RSASIGMD5) != 0) {
Damien Miller324541e2013-12-31 12:25:40 +1100506 logit("Client version \"%.100s\" uses unsafe RSA signature "
507 "scheme; disabling use of RSA keys", remote_version);
Damien Miller58cd63b2014-01-10 10:59:24 +1100508 }
djm@openbsd.org95767262016-03-07 19:02:43 +0000509 if ((ssh->compat & SSH_BUG_DERIVEKEY) != 0) {
Damien Miller58cd63b2014-01-10 10:59:24 +1100510 fatal("Client version \"%.100s\" uses unsafe key agreement; "
511 "refusing connection", remote_version);
512 }
Damien Miller27dbe6f2001-03-19 22:36:20 +1100513
Damien Miller78928792000-04-12 20:17:38 +1000514 mismatch = 0;
Ben Lindstrom1c37c6a2001-12-06 18:00:18 +0000515 switch (remote_major) {
Damien Millerb38eff82000-04-01 11:09:21 +1000516 case 1:
Damien Millereba71ba2000-04-29 23:57:08 +1000517 if (remote_minor == 99) {
518 if (options.protocol & SSH_PROTO_2)
519 enable_compat20();
520 else
521 mismatch = 1;
522 break;
523 }
Damien Miller78928792000-04-12 20:17:38 +1000524 if (!(options.protocol & SSH_PROTO_1)) {
525 mismatch = 1;
526 break;
527 }
Damien Millerb38eff82000-04-01 11:09:21 +1000528 if (remote_minor < 3) {
Damien Miller37023962000-07-11 17:31:38 +1000529 packet_disconnect("Your ssh version is too old and "
Damien Millerb38eff82000-04-01 11:09:21 +1000530 "is no longer supported. Please install a newer version.");
531 } else if (remote_minor == 3) {
532 /* note that this disables agent-forwarding */
533 enable_compat13();
534 }
Damien Miller78928792000-04-12 20:17:38 +1000535 break;
Damien Millerefb4afe2000-04-12 18:45:05 +1000536 case 2:
Damien Miller78928792000-04-12 20:17:38 +1000537 if (options.protocol & SSH_PROTO_2) {
Damien Millerefb4afe2000-04-12 18:45:05 +1000538 enable_compat20();
539 break;
540 }
541 /* FALLTHROUGH */
Damien Miller4af51302000-04-16 11:18:38 +1000542 default:
Damien Miller78928792000-04-12 20:17:38 +1000543 mismatch = 1;
Damien Millerb38eff82000-04-01 11:09:21 +1000544 break;
545 }
Damien Millerefb4afe2000-04-12 18:45:05 +1000546 chop(server_version_string);
Damien Miller78928792000-04-12 20:17:38 +1000547 debug("Local version string %.200s", server_version_string);
548
549 if (mismatch) {
550 s = "Protocol major versions differ.\n";
Darren Tucker9f63f222003-07-03 13:46:56 +1000551 (void) atomicio(vwrite, sock_out, s, strlen(s));
Damien Miller78928792000-04-12 20:17:38 +1000552 close(sock_in);
553 close(sock_out);
djm@openbsd.org95767262016-03-07 19:02:43 +0000554 logit("Protocol major versions differ for %s port %d: "
555 "%.200s vs. %.200s",
556 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
Damien Miller78928792000-04-12 20:17:38 +1000557 server_version_string, client_version_string);
Darren Tucker3e33cec2003-10-02 16:12:36 +1000558 cleanup_exit(255);
Damien Miller78928792000-04-12 20:17:38 +1000559 }
Damien Millereba71ba2000-04-29 23:57:08 +1000560}
561
Damien Miller0bc1bd82000-11-13 22:57:25 +1100562/* Destroy the host and server keys. They will no longer be needed. */
Damien Millereba71ba2000-04-29 23:57:08 +1000563void
564destroy_sensitive_data(void)
565{
Damien Miller0bc1bd82000-11-13 22:57:25 +1100566 int i;
567
568 if (sensitive_data.server_key) {
569 key_free(sensitive_data.server_key);
570 sensitive_data.server_key = NULL;
571 }
Damien Miller9f0f5c62001-12-21 14:45:46 +1100572 for (i = 0; i < options.num_host_key_files; i++) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100573 if (sensitive_data.host_keys[i]) {
574 key_free(sensitive_data.host_keys[i]);
575 sensitive_data.host_keys[i] = NULL;
576 }
Damien Miller0a80ca12010-02-27 07:55:05 +1100577 if (sensitive_data.host_certificates[i]) {
578 key_free(sensitive_data.host_certificates[i]);
579 sensitive_data.host_certificates[i] = NULL;
580 }
Damien Miller0bc1bd82000-11-13 22:57:25 +1100581 }
582 sensitive_data.ssh1_host_key = NULL;
Damien Millera5103f42014-02-04 11:20:14 +1100583 explicit_bzero(sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
Damien Miller0bc1bd82000-11-13 22:57:25 +1100584}
Damien Miller0bc1bd82000-11-13 22:57:25 +1100585
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000586/* Demote private to public keys for network child */
587void
588demote_sensitive_data(void)
589{
590 Key *tmp;
591 int i;
592
593 if (sensitive_data.server_key) {
594 tmp = key_demote(sensitive_data.server_key);
595 key_free(sensitive_data.server_key);
596 sensitive_data.server_key = tmp;
597 }
598
599 for (i = 0; i < options.num_host_key_files; i++) {
600 if (sensitive_data.host_keys[i]) {
601 tmp = key_demote(sensitive_data.host_keys[i]);
602 key_free(sensitive_data.host_keys[i]);
603 sensitive_data.host_keys[i] = tmp;
604 if (tmp->type == KEY_RSA1)
605 sensitive_data.ssh1_host_key = tmp;
606 }
Damien Miller0a80ca12010-02-27 07:55:05 +1100607 /* Certs do not need demotion */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000608 }
609
610 /* We do not clear ssh1_host key and cookie. XXX - Okay Niels? */
611}
612
Ben Lindstrom08105192002-03-22 02:50:06 +0000613static void
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000614privsep_preauth_child(void)
615{
Darren Tucker64cee362009-06-21 20:26:17 +1000616 u_int32_t rnd[256];
Ben Lindstrom810af962002-07-04 00:11:40 +0000617 gid_t gidset[1];
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000618
619 /* Enable challenge-response authentication for privilege separation */
620 privsep_challenge_enable();
621
Damien Millerfb3423b2014-02-27 10:20:07 +1100622#ifdef GSSAPI
Damien Millere6a74ae2014-02-27 10:17:49 +1100623 /* Cache supported mechanism OIDs for later use */
624 if (options.gss_authentication)
625 ssh_gssapi_prepare_supported_oids();
Damien Millerfb3423b2014-02-27 10:20:07 +1100626#endif
Damien Millere6a74ae2014-02-27 10:17:49 +1100627
Damien Miller76e95da2008-03-07 18:31:24 +1100628 arc4random_stir();
Damien Miller354c48c2008-05-19 14:50:00 +1000629 arc4random_buf(rnd, sizeof(rnd));
Damien Miller72ef7c12015-01-15 02:21:31 +1100630#ifdef WITH_OPENSSL
Ben Lindstrom5a9d0ea2002-07-04 00:12:53 +0000631 RAND_seed(rnd, sizeof(rnd));
Damien Miller07889c72015-11-14 18:44:49 +1100632 if ((RAND_bytes((u_char *)rnd, 1)) != 1)
633 fatal("%s: RAND_bytes failed", __func__);
Damien Miller72ef7c12015-01-15 02:21:31 +1100634#endif
Damien Miller1d2c4562014-02-04 11:18:20 +1100635 explicit_bzero(rnd, sizeof(rnd));
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000636
637 /* Demote the private keys to public keys. */
638 demote_sensitive_data();
639
djm@openbsd.org5b4010d2015-11-16 22:51:05 +0000640 /* Demote the child */
641 if (getuid() == 0 || geteuid() == 0) {
642 /* Change our root directory */
643 if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1)
644 fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR,
645 strerror(errno));
646 if (chdir("/") == -1)
647 fatal("chdir(\"/\"): %s", strerror(errno));
Ben Lindstrom6328ab32002-03-22 02:54:23 +0000648
djm@openbsd.org5b4010d2015-11-16 22:51:05 +0000649 /* Drop our privileges */
650 debug3("privsep user:group %u:%u", (u_int)privsep_pw->pw_uid,
651 (u_int)privsep_pw->pw_gid);
652 gidset[0] = privsep_pw->pw_gid;
653 if (setgroups(1, gidset) < 0)
654 fatal("setgroups: %.100s", strerror(errno));
655 permanently_set_uid(privsep_pw);
656 }
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000657}
658
Darren Tucker3e33cec2003-10-02 16:12:36 +1000659static int
660privsep_preauth(Authctxt *authctxt)
Ben Lindstrom943481c2002-03-22 03:43:46 +0000661{
djm@openbsd.org141efe42015-01-14 20:05:27 +0000662 int status, r;
Ben Lindstrom943481c2002-03-22 03:43:46 +0000663 pid_t pid;
Damien Miller69ff1df2011-06-23 08:30:03 +1000664 struct ssh_sandbox *box = NULL;
Ben Lindstrom943481c2002-03-22 03:43:46 +0000665
666 /* Set up unprivileged child process to deal with network data */
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000667 pmonitor = monitor_init();
Ben Lindstrom943481c2002-03-22 03:43:46 +0000668 /* Store a pointer to the kex for later rekeying */
markus@openbsd.org091c3022015-01-19 19:52:16 +0000669 pmonitor->m_pkex = &active_state->kex;
Ben Lindstrom943481c2002-03-22 03:43:46 +0000670
Damien Miller5a5c2b92012-07-31 12:21:34 +1000671 if (use_privsep == PRIVSEP_ON)
Damien Miller868ea1e2014-01-17 16:47:04 +1100672 box = ssh_sandbox_init(pmonitor);
Ben Lindstrom943481c2002-03-22 03:43:46 +0000673 pid = fork();
674 if (pid == -1) {
675 fatal("fork of unprivileged child failed");
676 } else if (pid != 0) {
Ben Lindstromce0f6342002-06-11 16:42:49 +0000677 debug2("Network child is on pid %ld", (long)pid);
Ben Lindstrom943481c2002-03-22 03:43:46 +0000678
Darren Tucker3b4b2d32012-07-02 18:54:31 +1000679 pmonitor->m_pid = pid;
djm@openbsd.org141efe42015-01-14 20:05:27 +0000680 if (have_agent) {
681 r = ssh_get_authentication_socket(&auth_sock);
682 if (r != 0) {
683 error("Could not get agent socket: %s",
684 ssh_err(r));
685 have_agent = 0;
686 }
687 }
Damien Miller69ff1df2011-06-23 08:30:03 +1000688 if (box != NULL)
689 ssh_sandbox_parent_preauth(box, pid);
Darren Tucker3e33cec2003-10-02 16:12:36 +1000690 monitor_child_preauth(authctxt, pmonitor);
Ben Lindstrom943481c2002-03-22 03:43:46 +0000691
692 /* Sync memory */
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000693 monitor_sync(pmonitor);
Ben Lindstrom943481c2002-03-22 03:43:46 +0000694
695 /* Wait for the child's exit status */
Damien Miller69ff1df2011-06-23 08:30:03 +1000696 while (waitpid(pid, &status, 0) < 0) {
Damien Miller9ee2c602011-09-22 21:38:30 +1000697 if (errno == EINTR)
698 continue;
699 pmonitor->m_pid = -1;
700 fatal("%s: waitpid: %s", __func__, strerror(errno));
Damien Miller69ff1df2011-06-23 08:30:03 +1000701 }
Damien Miller9ee2c602011-09-22 21:38:30 +1000702 privsep_is_preauth = 0;
703 pmonitor->m_pid = -1;
Damien Miller69ff1df2011-06-23 08:30:03 +1000704 if (WIFEXITED(status)) {
705 if (WEXITSTATUS(status) != 0)
706 fatal("%s: preauth child exited with status %d",
707 __func__, WEXITSTATUS(status));
708 } else if (WIFSIGNALED(status))
709 fatal("%s: preauth child terminated by signal %d",
710 __func__, WTERMSIG(status));
711 if (box != NULL)
712 ssh_sandbox_parent_finish(box);
713 return 1;
Ben Lindstrom943481c2002-03-22 03:43:46 +0000714 } else {
715 /* child */
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000716 close(pmonitor->m_sendfd);
Damien Miller8f0bf232011-06-20 14:42:23 +1000717 close(pmonitor->m_log_recvfd);
718
719 /* Arrange for logging to be sent to the monitor */
720 set_log_handler(mm_log_handler, pmonitor);
Ben Lindstrom943481c2002-03-22 03:43:46 +0000721
djm@openbsd.org5b4010d2015-11-16 22:51:05 +0000722 privsep_preauth_child();
Ben Lindstromf90f58d2002-03-26 01:53:03 +0000723 setproctitle("%s", "[net]");
Damien Miller69ff1df2011-06-23 08:30:03 +1000724 if (box != NULL)
725 ssh_sandbox_child(box);
726
727 return 0;
Ben Lindstrom943481c2002-03-22 03:43:46 +0000728 }
Ben Lindstrom943481c2002-03-22 03:43:46 +0000729}
730
Ben Lindstrom08105192002-03-22 02:50:06 +0000731static void
Ben Lindstrom943481c2002-03-22 03:43:46 +0000732privsep_postauth(Authctxt *authctxt)
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000733{
Damien Miller76e95da2008-03-07 18:31:24 +1100734 u_int32_t rnd[256];
Damien Miller76e95da2008-03-07 18:31:24 +1100735
Tim Rice9dd30812002-07-07 13:43:36 -0700736#ifdef DISABLE_FD_PASSING
Tim Rice8eff3192002-06-25 15:35:15 -0700737 if (1) {
738#else
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000739 if (authctxt->pw->pw_uid == 0 || options.use_login) {
Tim Rice8eff3192002-06-25 15:35:15 -0700740#endif
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000741 /* File descriptor passing is broken or root login */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000742 use_privsep = 0;
Darren Tucker45b01422005-10-03 18:20:00 +1000743 goto skip;
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000744 }
Ben Lindstrom6328ab32002-03-22 02:54:23 +0000745
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000746 /* New socket pair */
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000747 monitor_reinit(pmonitor);
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000748
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000749 pmonitor->m_pid = fork();
750 if (pmonitor->m_pid == -1)
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000751 fatal("fork of unprivileged child failed");
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000752 else if (pmonitor->m_pid != 0) {
Damien Millerb61f3fc2008-07-11 17:36:48 +1000753 verbose("User child is on pid %ld", (long)pmonitor->m_pid);
Darren Tuckereb578622004-08-12 23:08:14 +1000754 buffer_clear(&loginmsg);
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000755 monitor_child_postauth(pmonitor);
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000756
757 /* NEVERREACHED */
758 exit(0);
759 }
760
Damien Miller8f0bf232011-06-20 14:42:23 +1000761 /* child */
762
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000763 close(pmonitor->m_sendfd);
Damien Miller8f0bf232011-06-20 14:42:23 +1000764 pmonitor->m_sendfd = -1;
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000765
766 /* Demote the private keys to public keys. */
767 demote_sensitive_data();
768
Damien Miller76e95da2008-03-07 18:31:24 +1100769 arc4random_stir();
Damien Miller354c48c2008-05-19 14:50:00 +1000770 arc4random_buf(rnd, sizeof(rnd));
Damien Miller72ef7c12015-01-15 02:21:31 +1100771#ifdef WITH_OPENSSL
Damien Miller76e95da2008-03-07 18:31:24 +1100772 RAND_seed(rnd, sizeof(rnd));
Damien Miller07889c72015-11-14 18:44:49 +1100773 if ((RAND_bytes((u_char *)rnd, 1)) != 1)
774 fatal("%s: RAND_bytes failed", __func__);
Damien Miller72ef7c12015-01-15 02:21:31 +1100775#endif
Damien Miller1d2c4562014-02-04 11:18:20 +1100776 explicit_bzero(rnd, sizeof(rnd));
Damien Miller76e95da2008-03-07 18:31:24 +1100777
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000778 /* Drop privileges */
779 do_setusercontext(authctxt->pw);
780
Darren Tucker45b01422005-10-03 18:20:00 +1000781 skip:
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000782 /* It is safe now to apply the key state */
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000783 monitor_apply_keystate(pmonitor);
Damien Miller9786e6e2005-07-26 21:54:56 +1000784
785 /*
786 * Tell the packet layer that authentication was successful, since
787 * this information is not part of the key state.
788 */
789 packet_set_authenticated();
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000790}
791
Ben Lindstrombba81212001-06-25 05:01:22 +0000792static char *
Damien Miller0bc1bd82000-11-13 22:57:25 +1100793list_hostkey_types(void)
794{
Damien Miller0e3b8722002-01-22 23:26:38 +1100795 Buffer b;
Damien Millerf58b58c2003-11-17 21:18:23 +1100796 const char *p;
797 char *ret;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100798 int i;
Damien Miller0a80ca12010-02-27 07:55:05 +1100799 Key *key;
Damien Miller0e3b8722002-01-22 23:26:38 +1100800
801 buffer_init(&b);
Damien Miller9f0f5c62001-12-21 14:45:46 +1100802 for (i = 0; i < options.num_host_key_files; i++) {
Damien Miller0a80ca12010-02-27 07:55:05 +1100803 key = sensitive_data.host_keys[i];
djm@openbsd.orgce63c4b2015-02-16 22:30:03 +0000804 if (key == NULL)
Damien Miller85b45e02013-07-20 13:21:52 +1000805 key = sensitive_data.host_pubkeys[i];
djm@openbsd.org25b14612015-07-17 02:47:45 +0000806 if (key == NULL || key->type == KEY_RSA1)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100807 continue;
markus@openbsd.org3a1638d2015-07-10 06:21:53 +0000808 /* Check that the key is accepted in HostkeyAlgorithms */
809 if (match_pattern_list(sshkey_ssh_name(key),
810 options.hostkeyalgorithms, 0) != 1) {
811 debug3("%s: %s key not permitted by HostkeyAlgorithms",
812 __func__, sshkey_ssh_name(key));
813 continue;
814 }
Ben Lindstrom1c37c6a2001-12-06 18:00:18 +0000815 switch (key->type) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100816 case KEY_RSA:
817 case KEY_DSA:
Damien Millereb8b60e2010-08-31 22:41:14 +1000818 case KEY_ECDSA:
Damien Miller5be9d9e2013-12-07 11:24:01 +1100819 case KEY_ED25519:
Damien Miller0e3b8722002-01-22 23:26:38 +1100820 if (buffer_len(&b) > 0)
821 buffer_append(&b, ",", 1);
822 p = key_ssh_name(key);
823 buffer_append(&b, p, strlen(p));
markus@openbsd.org76c9fbb2015-12-04 16:41:28 +0000824
825 /* for RSA we also support SHA2 signatures */
826 if (key->type == KEY_RSA) {
827 p = ",rsa-sha2-512,rsa-sha2-256";
828 buffer_append(&b, p, strlen(p));
829 }
Damien Miller0bc1bd82000-11-13 22:57:25 +1100830 break;
831 }
Damien Miller0a80ca12010-02-27 07:55:05 +1100832 /* If the private key has a cert peer, then list that too */
833 key = sensitive_data.host_certificates[i];
834 if (key == NULL)
835 continue;
836 switch (key->type) {
837 case KEY_RSA_CERT:
838 case KEY_DSA_CERT:
Damien Millereb8b60e2010-08-31 22:41:14 +1000839 case KEY_ECDSA_CERT:
Damien Miller5be9d9e2013-12-07 11:24:01 +1100840 case KEY_ED25519_CERT:
Damien Miller0a80ca12010-02-27 07:55:05 +1100841 if (buffer_len(&b) > 0)
842 buffer_append(&b, ",", 1);
843 p = key_ssh_name(key);
844 buffer_append(&b, p, strlen(p));
845 break;
846 }
Damien Miller0bc1bd82000-11-13 22:57:25 +1100847 }
djm@openbsd.org1a31d022016-05-02 08:49:03 +0000848 if ((ret = sshbuf_dup_string(&b)) == NULL)
849 fatal("%s: sshbuf_dup_string failed", __func__);
Damien Miller0e3b8722002-01-22 23:26:38 +1100850 buffer_free(&b);
Damien Millerf58b58c2003-11-17 21:18:23 +1100851 debug("list_hostkey_types: %s", ret);
852 return ret;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100853}
854
Damien Miller0a80ca12010-02-27 07:55:05 +1100855static Key *
djm@openbsd.org5104db72015-01-26 06:10:03 +0000856get_hostkey_by_type(int type, int nid, int need_private, struct ssh *ssh)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100857{
858 int i;
Damien Miller0a80ca12010-02-27 07:55:05 +1100859 Key *key;
Ben Lindstrom822b6342002-06-23 21:38:49 +0000860
Damien Miller9f0f5c62001-12-21 14:45:46 +1100861 for (i = 0; i < options.num_host_key_files; i++) {
Damien Miller4e270b02010-04-16 15:56:21 +1000862 switch (type) {
Damien Miller4e270b02010-04-16 15:56:21 +1000863 case KEY_RSA_CERT:
864 case KEY_DSA_CERT:
Damien Millereb8b60e2010-08-31 22:41:14 +1000865 case KEY_ECDSA_CERT:
Damien Miller5be9d9e2013-12-07 11:24:01 +1100866 case KEY_ED25519_CERT:
Damien Miller0a80ca12010-02-27 07:55:05 +1100867 key = sensitive_data.host_certificates[i];
Damien Miller4e270b02010-04-16 15:56:21 +1000868 break;
869 default:
Damien Miller0a80ca12010-02-27 07:55:05 +1100870 key = sensitive_data.host_keys[i];
Damien Miller85b45e02013-07-20 13:21:52 +1000871 if (key == NULL && !need_private)
872 key = sensitive_data.host_pubkeys[i];
Damien Miller4e270b02010-04-16 15:56:21 +1000873 break;
874 }
djm@openbsd.org5104db72015-01-26 06:10:03 +0000875 if (key != NULL && key->type == type &&
876 (key->type != KEY_ECDSA || key->ecdsa_nid == nid))
Damien Miller0a80ca12010-02-27 07:55:05 +1100877 return need_private ?
878 sensitive_data.host_keys[i] : key;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100879 }
880 return NULL;
Damien Millerb38eff82000-04-01 11:09:21 +1000881}
882
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000883Key *
djm@openbsd.org5104db72015-01-26 06:10:03 +0000884get_hostkey_public_by_type(int type, int nid, struct ssh *ssh)
Damien Miller0a80ca12010-02-27 07:55:05 +1100885{
djm@openbsd.org5104db72015-01-26 06:10:03 +0000886 return get_hostkey_by_type(type, nid, 0, ssh);
Damien Miller0a80ca12010-02-27 07:55:05 +1100887}
888
889Key *
djm@openbsd.org5104db72015-01-26 06:10:03 +0000890get_hostkey_private_by_type(int type, int nid, struct ssh *ssh)
Damien Miller0a80ca12010-02-27 07:55:05 +1100891{
djm@openbsd.org5104db72015-01-26 06:10:03 +0000892 return get_hostkey_by_type(type, nid, 1, ssh);
Damien Miller0a80ca12010-02-27 07:55:05 +1100893}
894
895Key *
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000896get_hostkey_by_index(int ind)
897{
898 if (ind < 0 || ind >= options.num_host_key_files)
899 return (NULL);
900 return (sensitive_data.host_keys[ind]);
901}
902
Damien Miller85b45e02013-07-20 13:21:52 +1000903Key *
markus@openbsd.org57d10cb2015-01-19 20:16:15 +0000904get_hostkey_public_by_index(int ind, struct ssh *ssh)
Damien Miller85b45e02013-07-20 13:21:52 +1000905{
906 if (ind < 0 || ind >= options.num_host_key_files)
907 return (NULL);
908 return (sensitive_data.host_pubkeys[ind]);
909}
910
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000911int
djm@openbsd.org523463a2015-02-16 22:13:32 +0000912get_hostkey_index(Key *key, int compare, struct ssh *ssh)
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000913{
914 int i;
Ben Lindstrom822b6342002-06-23 21:38:49 +0000915
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000916 for (i = 0; i < options.num_host_key_files; i++) {
Damien Miller0a80ca12010-02-27 07:55:05 +1100917 if (key_is_cert(key)) {
djm@openbsd.org523463a2015-02-16 22:13:32 +0000918 if (key == sensitive_data.host_certificates[i] ||
919 (compare && sensitive_data.host_certificates[i] &&
920 sshkey_equal(key,
921 sensitive_data.host_certificates[i])))
Damien Miller0a80ca12010-02-27 07:55:05 +1100922 return (i);
923 } else {
djm@openbsd.org523463a2015-02-16 22:13:32 +0000924 if (key == sensitive_data.host_keys[i] ||
925 (compare && sensitive_data.host_keys[i] &&
926 sshkey_equal(key, sensitive_data.host_keys[i])))
Damien Miller0a80ca12010-02-27 07:55:05 +1100927 return (i);
djm@openbsd.org523463a2015-02-16 22:13:32 +0000928 if (key == sensitive_data.host_pubkeys[i] ||
929 (compare && sensitive_data.host_pubkeys[i] &&
930 sshkey_equal(key, sensitive_data.host_pubkeys[i])))
Damien Miller85b45e02013-07-20 13:21:52 +1000931 return (i);
Damien Miller0a80ca12010-02-27 07:55:05 +1100932 }
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000933 }
934 return (-1);
935}
936
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000937/* Inform the client of all hostkeys */
938static void
939notify_hostkeys(struct ssh *ssh)
940{
941 struct sshbuf *buf;
942 struct sshkey *key;
943 int i, nkeys, r;
944 char *fp;
945
dtucker@openbsd.orgd8f391c2015-04-10 05:16:50 +0000946 /* Some clients cannot cope with the hostkeys message, skip those. */
947 if (datafellows & SSH_BUG_HOSTKEYS)
948 return;
949
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000950 if ((buf = sshbuf_new()) == NULL)
951 fatal("%s: sshbuf_new", __func__);
952 for (i = nkeys = 0; i < options.num_host_key_files; i++) {
953 key = get_hostkey_public_by_index(i, ssh);
954 if (key == NULL || key->type == KEY_UNSPEC ||
955 key->type == KEY_RSA1 || sshkey_is_cert(key))
956 continue;
957 fp = sshkey_fingerprint(key, options.fingerprint_hash,
958 SSH_FP_DEFAULT);
959 debug3("%s: key %d: %s %s", __func__, i,
960 sshkey_ssh_name(key), fp);
961 free(fp);
djm@openbsd.org523463a2015-02-16 22:13:32 +0000962 if (nkeys == 0) {
963 packet_start(SSH2_MSG_GLOBAL_REQUEST);
djm@openbsd.org44732de2015-02-20 22:17:21 +0000964 packet_put_cstring("hostkeys-00@openssh.com");
djm@openbsd.org523463a2015-02-16 22:13:32 +0000965 packet_put_char(0); /* want-reply */
966 }
967 sshbuf_reset(buf);
968 if ((r = sshkey_putb(key, buf)) != 0)
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000969 fatal("%s: couldn't put hostkey %d: %s",
970 __func__, i, ssh_err(r));
djm@openbsd.org523463a2015-02-16 22:13:32 +0000971 packet_put_string(sshbuf_ptr(buf), sshbuf_len(buf));
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000972 nkeys++;
973 }
djm@openbsd.org523463a2015-02-16 22:13:32 +0000974 debug3("%s: sent %d hostkeys", __func__, nkeys);
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000975 if (nkeys == 0)
976 fatal("%s: no hostkeys", __func__);
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000977 packet_send();
djm@openbsd.org523463a2015-02-16 22:13:32 +0000978 sshbuf_free(buf);
djm@openbsd.org8d4f8722015-01-26 03:04:45 +0000979}
980
Damien Miller942da032000-08-18 13:59:06 +1000981/*
982 * returns 1 if connection should be dropped, 0 otherwise.
983 * dropping starts at connection #max_startups_begin with a probability
984 * of (max_startups_rate/100). the probability increases linearly until
985 * all connections are dropped for startups > max_startups
986 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000987static int
Damien Miller942da032000-08-18 13:59:06 +1000988drop_connection(int startups)
989{
Darren Tucker178fa662004-11-05 20:09:09 +1100990 int p, r;
Damien Miller942da032000-08-18 13:59:06 +1000991
992 if (startups < options.max_startups_begin)
993 return 0;
994 if (startups >= options.max_startups)
995 return 1;
996 if (options.max_startups_rate == 100)
997 return 1;
998
999 p = 100 - options.max_startups_rate;
1000 p *= startups - options.max_startups_begin;
Darren Tucker178fa662004-11-05 20:09:09 +11001001 p /= options.max_startups - options.max_startups_begin;
Damien Miller942da032000-08-18 13:59:06 +10001002 p += options.max_startups_rate;
Damien Miller354c48c2008-05-19 14:50:00 +10001003 r = arc4random_uniform(100);
Damien Miller942da032000-08-18 13:59:06 +10001004
Darren Tucker3269b132004-11-05 20:20:59 +11001005 debug("drop_connection: p %d, r %d", p, r);
Damien Miller942da032000-08-18 13:59:06 +10001006 return (r < p) ? 1 : 0;
1007}
1008
Ben Lindstromade03f62001-12-06 18:22:17 +00001009static void
1010usage(void)
1011{
Damien Miller0c889cd2004-03-22 09:36:00 +11001012 fprintf(stderr, "%s, %s\n",
Damien Miller1f0311c2014-05-15 14:24:09 +10001013 SSH_RELEASE,
1014#ifdef WITH_OPENSSL
1015 SSLeay_version(SSLEAY_VERSION)
1016#else
1017 "without OpenSSL"
1018#endif
1019 );
Damien Millerb4087862004-03-22 09:35:21 +11001020 fprintf(stderr,
Damien Miller0a80ca12010-02-27 07:55:05 +11001021"usage: sshd [-46DdeiqTt] [-b bits] [-C connection_spec] [-c host_cert_file]\n"
Damien Miller03d4d7e2013-04-23 15:21:06 +10001022" [-E log_file] [-f config_file] [-g login_grace_time]\n"
1023" [-h host_key_file] [-k key_gen_time] [-o option] [-p port]\n"
1024" [-u len]\n"
Damien Millerb4087862004-03-22 09:35:21 +11001025 );
Ben Lindstromade03f62001-12-06 18:22:17 +00001026 exit(1);
1027}
1028
Darren Tucker645ab752004-06-25 13:33:20 +10001029static void
djm@openbsd.org1a31d022016-05-02 08:49:03 +00001030send_rexec_state(int fd, struct sshbuf *conf)
Darren Tucker645ab752004-06-25 13:33:20 +10001031{
djm@openbsd.org1a31d022016-05-02 08:49:03 +00001032 struct sshbuf *m;
1033 int r;
Darren Tucker645ab752004-06-25 13:33:20 +10001034
djm@openbsd.org1a31d022016-05-02 08:49:03 +00001035 debug3("%s: entering fd = %d config len %zu", __func__, fd,
1036 sshbuf_len(conf));
Darren Tucker645ab752004-06-25 13:33:20 +10001037
1038 /*
1039 * Protocol from reexec master to child:
1040 * string configuration
1041 * u_int ephemeral_key_follows
1042 * bignum e (only if ephemeral_key_follows == 1)
1043 * bignum n "
1044 * bignum d "
1045 * bignum iqmp "
1046 * bignum p "
1047 * bignum q "
Darren Tuckerc6f82192005-09-27 22:46:32 +10001048 * string rngseed (only if OpenSSL is not self-seeded)
Darren Tucker645ab752004-06-25 13:33:20 +10001049 */
djm@openbsd.org1a31d022016-05-02 08:49:03 +00001050 if ((m = sshbuf_new()) == NULL)
1051 fatal("%s: sshbuf_new failed", __func__);
1052 if ((r = sshbuf_put_stringb(m, conf)) != 0)
1053 fatal("%s: buffer error: %s", __func__, ssh_err(r));
Darren Tucker645ab752004-06-25 13:33:20 +10001054
Damien Miller1f0311c2014-05-15 14:24:09 +10001055#ifdef WITH_SSH1
Darren Tuckerfc959702004-07-17 16:12:08 +10001056 if (sensitive_data.server_key != NULL &&
Darren Tucker645ab752004-06-25 13:33:20 +10001057 sensitive_data.server_key->type == KEY_RSA1) {
djm@openbsd.org1a31d022016-05-02 08:49:03 +00001058 if ((r = sshbuf_put_u32(m, 1)) != 0 ||
1059 (r = sshbuf_put_bignum1(m,
1060 sensitive_data.server_key->rsa->e)) != 0 ||
1061 (r = sshbuf_put_bignum1(m,
1062 sensitive_data.server_key->rsa->n)) != 0 ||
1063 (r = sshbuf_put_bignum1(m,
1064 sensitive_data.server_key->rsa->d)) != 0 ||
1065 (r = sshbuf_put_bignum1(m,
1066 sensitive_data.server_key->rsa->iqmp)) != 0 ||
1067 (r = sshbuf_put_bignum1(m,
1068 sensitive_data.server_key->rsa->p)) != 0 ||
1069 (r = sshbuf_put_bignum1(m,
1070 sensitive_data.server_key->rsa->q)) != 0)
1071 fatal("%s: buffer error: %s", __func__, ssh_err(r));
Darren Tucker645ab752004-06-25 13:33:20 +10001072 } else
Damien Miller1f0311c2014-05-15 14:24:09 +10001073#endif
djm@openbsd.org1a31d022016-05-02 08:49:03 +00001074 if ((r = sshbuf_put_u32(m, 1)) != 0)
1075 fatal("%s: buffer error: %s", __func__, ssh_err(r));
Darren Tucker645ab752004-06-25 13:33:20 +10001076
Damien Miller72ef7c12015-01-15 02:21:31 +11001077#if defined(WITH_OPENSSL) && !defined(OPENSSL_PRNG_ONLY)
djm@openbsd.org1a31d022016-05-02 08:49:03 +00001078 rexec_send_rng_seed(m);
Darren Tuckerc6f82192005-09-27 22:46:32 +10001079#endif
1080
djm@openbsd.org1a31d022016-05-02 08:49:03 +00001081 if (ssh_msg_send(fd, 0, m) == -1)
Darren Tucker645ab752004-06-25 13:33:20 +10001082 fatal("%s: ssh_msg_send failed", __func__);
1083
djm@openbsd.org1a31d022016-05-02 08:49:03 +00001084 sshbuf_free(m);
Darren Tucker645ab752004-06-25 13:33:20 +10001085
1086 debug3("%s: done", __func__);
1087}
1088
1089static void
1090recv_rexec_state(int fd, Buffer *conf)
1091{
1092 Buffer m;
1093 char *cp;
1094 u_int len;
1095
1096 debug3("%s: entering fd = %d", __func__, fd);
1097
1098 buffer_init(&m);
1099
1100 if (ssh_msg_recv(fd, &m) == -1)
1101 fatal("%s: ssh_msg_recv failed", __func__);
1102 if (buffer_get_char(&m) != 0)
1103 fatal("%s: rexec version mismatch", __func__);
1104
1105 cp = buffer_get_string(&m, &len);
1106 if (conf != NULL)
djm@openbsd.org31bc01c2016-05-02 14:10:58 +00001107 buffer_append(conf, cp, len);
Darren Tuckera627d422013-06-02 07:31:17 +10001108 free(cp);
Darren Tucker645ab752004-06-25 13:33:20 +10001109
1110 if (buffer_get_int(&m)) {
Damien Miller1f0311c2014-05-15 14:24:09 +10001111#ifdef WITH_SSH1
Darren Tucker645ab752004-06-25 13:33:20 +10001112 if (sensitive_data.server_key != NULL)
1113 key_free(sensitive_data.server_key);
1114 sensitive_data.server_key = key_new_private(KEY_RSA1);
1115 buffer_get_bignum(&m, sensitive_data.server_key->rsa->e);
1116 buffer_get_bignum(&m, sensitive_data.server_key->rsa->n);
1117 buffer_get_bignum(&m, sensitive_data.server_key->rsa->d);
1118 buffer_get_bignum(&m, sensitive_data.server_key->rsa->iqmp);
1119 buffer_get_bignum(&m, sensitive_data.server_key->rsa->p);
1120 buffer_get_bignum(&m, sensitive_data.server_key->rsa->q);
Damien Miller86687062014-07-02 15:28:02 +10001121 if (rsa_generate_additional_parameters(
1122 sensitive_data.server_key->rsa) != 0)
1123 fatal("%s: rsa_generate_additional_parameters "
1124 "error", __func__);
Damien Miller1f0311c2014-05-15 14:24:09 +10001125#endif
Darren Tucker645ab752004-06-25 13:33:20 +10001126 }
Darren Tuckerc6f82192005-09-27 22:46:32 +10001127
Damien Miller72ef7c12015-01-15 02:21:31 +11001128#if defined(WITH_OPENSSL) && !defined(OPENSSL_PRNG_ONLY)
Darren Tuckerc6f82192005-09-27 22:46:32 +10001129 rexec_recv_rng_seed(&m);
1130#endif
1131
Darren Tucker645ab752004-06-25 13:33:20 +10001132 buffer_free(&m);
1133
1134 debug3("%s: done", __func__);
1135}
1136
Damien Millera1f68402006-08-19 00:31:39 +10001137/* Accept a connection from inetd */
1138static void
1139server_accept_inetd(int *sock_in, int *sock_out)
1140{
1141 int fd;
1142
1143 startup_pipe = -1;
1144 if (rexeced_flag) {
1145 close(REEXEC_CONFIG_PASS_FD);
1146 *sock_in = *sock_out = dup(STDIN_FILENO);
1147 if (!debug_flag) {
1148 startup_pipe = dup(REEXEC_STARTUP_PIPE_FD);
1149 close(REEXEC_STARTUP_PIPE_FD);
1150 }
1151 } else {
1152 *sock_in = dup(STDIN_FILENO);
1153 *sock_out = dup(STDOUT_FILENO);
1154 }
1155 /*
1156 * We intentionally do not close the descriptors 0, 1, and 2
1157 * as our code for setting the descriptors won't work if
1158 * ttyfd happens to be one of those.
1159 */
1160 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1161 dup2(fd, STDIN_FILENO);
1162 dup2(fd, STDOUT_FILENO);
Darren Tucker0cca17f2013-06-06 08:21:14 +10001163 if (!log_stderr)
1164 dup2(fd, STDERR_FILENO);
1165 if (fd > (log_stderr ? STDERR_FILENO : STDOUT_FILENO))
Damien Millera1f68402006-08-19 00:31:39 +10001166 close(fd);
1167 }
1168 debug("inetd sockets after dupping: %d, %d", *sock_in, *sock_out);
1169}
1170
1171/*
1172 * Listen for TCP connections
1173 */
1174static void
1175server_listen(void)
1176{
1177 int ret, listen_sock, on = 1;
1178 struct addrinfo *ai;
1179 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1180
1181 for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
1182 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1183 continue;
1184 if (num_listen_socks >= MAX_LISTEN_SOCKS)
1185 fatal("Too many listen sockets. "
1186 "Enlarge MAX_LISTEN_SOCKS");
1187 if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen,
1188 ntop, sizeof(ntop), strport, sizeof(strport),
1189 NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
1190 error("getnameinfo failed: %.100s",
Darren Tucker4abde772007-12-29 02:43:51 +11001191 ssh_gai_strerror(ret));
Damien Millera1f68402006-08-19 00:31:39 +10001192 continue;
1193 }
1194 /* Create socket for listening. */
Darren Tucker7bd98e72010-01-10 10:31:12 +11001195 listen_sock = socket(ai->ai_family, ai->ai_socktype,
1196 ai->ai_protocol);
Damien Millera1f68402006-08-19 00:31:39 +10001197 if (listen_sock < 0) {
1198 /* kernel may not support ipv6 */
1199 verbose("socket: %.100s", strerror(errno));
1200 continue;
1201 }
1202 if (set_nonblock(listen_sock) == -1) {
1203 close(listen_sock);
1204 continue;
1205 }
1206 /*
1207 * Set socket options.
1208 * Allow local port reuse in TIME_WAIT.
1209 */
1210 if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
1211 &on, sizeof(on)) == -1)
1212 error("setsockopt SO_REUSEADDR: %s", strerror(errno));
1213
Damien Miller49d2a282008-01-20 08:56:00 +11001214 /* Only communicate in IPv6 over AF_INET6 sockets. */
Damien Miller04ee0f82009-11-18 17:48:30 +11001215 if (ai->ai_family == AF_INET6)
1216 sock_set_v6only(listen_sock);
Damien Miller49d2a282008-01-20 08:56:00 +11001217
Damien Millera1f68402006-08-19 00:31:39 +10001218 debug("Bind to port %s on %s.", strport, ntop);
1219
1220 /* Bind the socket to the desired port. */
1221 if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1222 error("Bind to port %s on %s failed: %.200s.",
1223 strport, ntop, strerror(errno));
1224 close(listen_sock);
1225 continue;
1226 }
1227 listen_socks[num_listen_socks] = listen_sock;
1228 num_listen_socks++;
1229
1230 /* Start listening on the port. */
1231 if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0)
1232 fatal("listen on [%s]:%s: %.100s",
1233 ntop, strport, strerror(errno));
1234 logit("Server listening on %s port %s.", ntop, strport);
1235 }
1236 freeaddrinfo(options.listen_addrs);
1237
1238 if (!num_listen_socks)
1239 fatal("Cannot bind any address.");
1240}
1241
1242/*
1243 * The main TCP accept loop. Note that, for the non-debug case, returns
1244 * from this function are in a forked subprocess.
1245 */
1246static void
1247server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
1248{
1249 fd_set *fdset;
1250 int i, j, ret, maxfd;
1251 int key_used = 0, startups = 0;
1252 int startup_p[2] = { -1 , -1 };
1253 struct sockaddr_storage from;
1254 socklen_t fromlen;
1255 pid_t pid;
Damien Miller045bda52013-09-14 09:44:37 +10001256 u_char rnd[256];
Damien Millera1f68402006-08-19 00:31:39 +10001257
1258 /* setup fd set for accept */
1259 fdset = NULL;
1260 maxfd = 0;
1261 for (i = 0; i < num_listen_socks; i++)
1262 if (listen_socks[i] > maxfd)
1263 maxfd = listen_socks[i];
1264 /* pipes connected to unauthenticated childs */
1265 startup_pipes = xcalloc(options.max_startups, sizeof(int));
1266 for (i = 0; i < options.max_startups; i++)
1267 startup_pipes[i] = -1;
1268
1269 /*
1270 * Stay listening for connections until the system crashes or
1271 * the daemon is killed with a signal.
1272 */
1273 for (;;) {
1274 if (received_sighup)
1275 sighup_restart();
mmcc@openbsd.orgd59ce082015-12-10 17:08:40 +00001276 free(fdset);
deraadt@openbsd.orgce445b02015-08-20 22:32:42 +00001277 fdset = xcalloc(howmany(maxfd + 1, NFDBITS),
Damien Millera1f68402006-08-19 00:31:39 +10001278 sizeof(fd_mask));
1279
1280 for (i = 0; i < num_listen_socks; i++)
1281 FD_SET(listen_socks[i], fdset);
1282 for (i = 0; i < options.max_startups; i++)
1283 if (startup_pipes[i] != -1)
1284 FD_SET(startup_pipes[i], fdset);
1285
1286 /* Wait in select until there is a connection. */
1287 ret = select(maxfd+1, fdset, NULL, NULL, NULL);
1288 if (ret < 0 && errno != EINTR)
1289 error("select: %.100s", strerror(errno));
1290 if (received_sigterm) {
1291 logit("Received signal %d; terminating.",
1292 (int) received_sigterm);
1293 close_listen_socks();
djm@openbsd.org161cf412014-12-22 07:55:51 +00001294 if (options.pid_file != NULL)
1295 unlink(options.pid_file);
Damien Miller26b57ce2011-05-05 14:15:09 +10001296 exit(received_sigterm == SIGTERM ? 0 : 255);
Damien Millera1f68402006-08-19 00:31:39 +10001297 }
1298 if (key_used && key_do_regen) {
1299 generate_ephemeral_server_key();
1300 key_used = 0;
1301 key_do_regen = 0;
1302 }
1303 if (ret < 0)
1304 continue;
1305
1306 for (i = 0; i < options.max_startups; i++)
1307 if (startup_pipes[i] != -1 &&
1308 FD_ISSET(startup_pipes[i], fdset)) {
1309 /*
1310 * the read end of the pipe is ready
1311 * if the child has closed the pipe
1312 * after successful authentication
1313 * or if the child has died
1314 */
1315 close(startup_pipes[i]);
1316 startup_pipes[i] = -1;
1317 startups--;
1318 }
1319 for (i = 0; i < num_listen_socks; i++) {
1320 if (!FD_ISSET(listen_socks[i], fdset))
1321 continue;
1322 fromlen = sizeof(from);
1323 *newsock = accept(listen_socks[i],
1324 (struct sockaddr *)&from, &fromlen);
1325 if (*newsock < 0) {
Damien Miller37f1c082013-04-23 15:20:43 +10001326 if (errno != EINTR && errno != EWOULDBLOCK &&
1327 errno != ECONNABORTED && errno != EAGAIN)
Damien Millera116d132012-04-22 11:23:46 +10001328 error("accept: %.100s",
1329 strerror(errno));
1330 if (errno == EMFILE || errno == ENFILE)
1331 usleep(100 * 1000);
Damien Millera1f68402006-08-19 00:31:39 +10001332 continue;
1333 }
1334 if (unset_nonblock(*newsock) == -1) {
1335 close(*newsock);
1336 continue;
1337 }
1338 if (drop_connection(startups) == 1) {
1339 debug("drop connection #%d", startups);
1340 close(*newsock);
1341 continue;
1342 }
1343 if (pipe(startup_p) == -1) {
1344 close(*newsock);
1345 continue;
1346 }
1347
1348 if (rexec_flag && socketpair(AF_UNIX,
1349 SOCK_STREAM, 0, config_s) == -1) {
1350 error("reexec socketpair: %s",
1351 strerror(errno));
1352 close(*newsock);
1353 close(startup_p[0]);
1354 close(startup_p[1]);
1355 continue;
1356 }
1357
1358 for (j = 0; j < options.max_startups; j++)
1359 if (startup_pipes[j] == -1) {
1360 startup_pipes[j] = startup_p[0];
1361 if (maxfd < startup_p[0])
1362 maxfd = startup_p[0];
1363 startups++;
1364 break;
1365 }
1366
1367 /*
1368 * Got connection. Fork a child to handle it, unless
1369 * we are in debugging mode.
1370 */
1371 if (debug_flag) {
1372 /*
1373 * In debugging mode. Close the listening
1374 * socket, and start processing the
1375 * connection without forking.
1376 */
1377 debug("Server will not fork when running in debugging mode.");
1378 close_listen_socks();
1379 *sock_in = *newsock;
1380 *sock_out = *newsock;
1381 close(startup_p[0]);
1382 close(startup_p[1]);
1383 startup_pipe = -1;
1384 pid = getpid();
1385 if (rexec_flag) {
1386 send_rexec_state(config_s[0],
1387 &cfg);
1388 close(config_s[0]);
1389 }
1390 break;
1391 }
1392
1393 /*
1394 * Normal production daemon. Fork, and have
1395 * the child process the connection. The
1396 * parent continues listening.
1397 */
Damien Miller1b06dc32006-08-31 03:24:41 +10001398 platform_pre_fork();
Damien Millera1f68402006-08-19 00:31:39 +10001399 if ((pid = fork()) == 0) {
1400 /*
1401 * Child. Close the listening and
1402 * max_startup sockets. Start using
1403 * the accepted socket. Reinitialize
1404 * logging (since our pid has changed).
1405 * We break out of the loop to handle
1406 * the connection.
1407 */
Damien Miller1b06dc32006-08-31 03:24:41 +10001408 platform_post_fork_child();
Damien Millera1f68402006-08-19 00:31:39 +10001409 startup_pipe = startup_p[1];
1410 close_startup_pipes();
1411 close_listen_socks();
1412 *sock_in = *newsock;
1413 *sock_out = *newsock;
1414 log_init(__progname,
1415 options.log_level,
1416 options.log_facility,
1417 log_stderr);
1418 if (rexec_flag)
1419 close(config_s[0]);
1420 break;
1421 }
1422
1423 /* Parent. Stay in the loop. */
Damien Miller1b06dc32006-08-31 03:24:41 +10001424 platform_post_fork_parent(pid);
Damien Millera1f68402006-08-19 00:31:39 +10001425 if (pid < 0)
1426 error("fork: %.100s", strerror(errno));
1427 else
1428 debug("Forked child %ld.", (long)pid);
1429
1430 close(startup_p[1]);
1431
1432 if (rexec_flag) {
1433 send_rexec_state(config_s[0], &cfg);
1434 close(config_s[0]);
1435 close(config_s[1]);
1436 }
1437
1438 /*
1439 * Mark that the key has been used (it
1440 * was "given" to the child).
1441 */
1442 if ((options.protocol & SSH_PROTO_1) &&
1443 key_used == 0) {
1444 /* Schedule server key regeneration alarm. */
1445 signal(SIGALRM, key_regeneration_alarm);
1446 alarm(options.key_regeneration_time);
1447 key_used = 1;
1448 }
1449
1450 close(*newsock);
1451
1452 /*
1453 * Ensure that our random state differs
1454 * from that of the child
1455 */
1456 arc4random_stir();
Damien Miller045bda52013-09-14 09:44:37 +10001457 arc4random_buf(rnd, sizeof(rnd));
Damien Miller72ef7c12015-01-15 02:21:31 +11001458#ifdef WITH_OPENSSL
Damien Miller045bda52013-09-14 09:44:37 +10001459 RAND_seed(rnd, sizeof(rnd));
Damien Miller07889c72015-11-14 18:44:49 +11001460 if ((RAND_bytes((u_char *)rnd, 1)) != 1)
1461 fatal("%s: RAND_bytes failed", __func__);
Damien Miller72ef7c12015-01-15 02:21:31 +11001462#endif
Damien Miller1d2c4562014-02-04 11:18:20 +11001463 explicit_bzero(rnd, sizeof(rnd));
Damien Millera1f68402006-08-19 00:31:39 +10001464 }
1465
1466 /* child process check (or debug mode) */
1467 if (num_listen_socks < 0)
1468 break;
1469 }
1470}
1471
djm@openbsd.org95767262016-03-07 19:02:43 +00001472/*
1473 * If IP options are supported, make sure there are none (log and
1474 * return an error if any are found). Basically we are worried about
1475 * source routing; it can be used to pretend you are somebody
1476 * (ip-address) you are not. That itself may be "almost acceptable"
1477 * under certain circumstances, but rhosts autentication is useless
1478 * if source routing is accepted. Notice also that if we just dropped
1479 * source routing here, the other side could use IP spoofing to do
1480 * rest of the interaction and could still bypass security. So we
1481 * exit here if we detect any IP options.
1482 */
1483static void
1484check_ip_options(struct ssh *ssh)
1485{
1486#ifdef IP_OPTIONS
1487 int sock_in = ssh_packet_get_connection_in(ssh);
1488 struct sockaddr_storage from;
1489 socklen_t option_size, i, fromlen = sizeof(from);
1490 u_char opts[200];
1491 char text[sizeof(opts) * 3 + 1];
1492
1493 memset(&from, 0, sizeof(from));
1494 if (getpeername(sock_in, (struct sockaddr *)&from,
1495 &fromlen) < 0)
1496 return;
1497 if (from.ss_family != AF_INET)
1498 return;
1499 /* XXX IPv6 options? */
1500
1501 if (getsockopt(sock_in, IPPROTO_IP, IP_OPTIONS, opts,
1502 &option_size) >= 0 && option_size != 0) {
1503 text[0] = '\0';
1504 for (i = 0; i < option_size; i++)
1505 snprintf(text + i*3, sizeof(text) - i*3,
1506 " %2.2x", opts[i]);
1507 fatal("Connection from %.100s port %d with IP opts: %.800s",
1508 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), text);
1509 }
1510 return;
1511#endif /* IP_OPTIONS */
1512}
Damien Millera1f68402006-08-19 00:31:39 +10001513
Damien Miller95def091999-11-25 00:26:21 +11001514/*
1515 * Main program for the daemon.
1516 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001517int
1518main(int ac, char **av)
1519{
djm@openbsd.org95767262016-03-07 19:02:43 +00001520 struct ssh *ssh = NULL;
Damien Miller95def091999-11-25 00:26:21 +11001521 extern char *optarg;
1522 extern int optind;
djm@openbsd.org141efe42015-01-14 20:05:27 +00001523 int r, opt, i, j, on = 1;
Damien Miller386c6a22004-06-30 22:40:20 +10001524 int sock_in = -1, sock_out = -1, newsock = -1;
Damien Miller95def091999-11-25 00:26:21 +11001525 const char *remote_ip;
1526 int remote_port;
dtucker@openbsd.org15fdfc92015-04-15 23:23:25 +00001527 char *fp, *line, *laddr, *logfile = NULL;
Damien Millera1f68402006-08-19 00:31:39 +10001528 int config_s[2] = { -1 , -1 };
Damien Millera6e3f012012-11-04 23:21:40 +11001529 u_int n;
Damien Millerb61f3fc2008-07-11 17:36:48 +10001530 u_int64_t ibytes, obytes;
Damien Miller6ca16c62008-06-16 07:50:58 +10001531 mode_t new_umask;
Ben Lindstromd0fca422001-03-26 13:44:06 +00001532 Key *key;
Damien Miller85b45e02013-07-20 13:21:52 +10001533 Key *pubkey;
1534 int keytype;
Darren Tucker3e33cec2003-10-02 16:12:36 +10001535 Authctxt *authctxt;
Darren Tuckerfbcf8272012-05-19 19:37:01 +10001536 struct connection_info *connection_info = get_connection_info(0, 0);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001537
dtucker@openbsd.orgffb1e7e2016-02-15 09:47:49 +00001538 ssh_malloc_init(); /* must be called before any mallocs */
1539
Kevin Steves0ea1d9d2002-04-25 18:17:04 +00001540#ifdef HAVE_SECUREWARE
1541 (void)set_auth_parameters(ac, av);
1542#endif
Damien Miller59d3d5b2003-08-22 09:34:41 +10001543 __progname = ssh_get_progname(av[0]);
Damien Millerf9b625c2000-07-09 22:42:32 +10001544
Damien Millera8ed44b2003-01-10 09:53:12 +11001545 /* Save argv. Duplicate so setproctitle emulation doesn't clobber it */
Damien Millerb8c656e2000-06-28 15:22:41 +10001546 saved_argc = ac;
Darren Tucker17c5d032004-06-25 14:22:23 +10001547 rexec_argc = ac;
Darren Tuckerd8093e42006-05-04 16:24:34 +10001548 saved_argv = xcalloc(ac + 1, sizeof(*saved_argv));
Damien Millera8ed44b2003-01-10 09:53:12 +11001549 for (i = 0; i < ac; i++)
1550 saved_argv[i] = xstrdup(av[i]);
Damien Miller04cb5362003-05-15 21:29:10 +10001551 saved_argv[i] = NULL;
Damien Millera8ed44b2003-01-10 09:53:12 +11001552
1553#ifndef HAVE_SETPROCTITLE
1554 /* Prepare for later setproctitle emulation */
1555 compat_init_setproctitle(ac, av);
Damien Millerf2e3e9d2003-06-02 12:15:54 +10001556 av = saved_argv;
Damien Millera8ed44b2003-01-10 09:53:12 +11001557#endif
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001558
Damien Millerbfba3542004-03-22 09:29:57 +11001559 if (geteuid() == 0 && setgroups(0, NULL) == -1)
1560 debug("setgroups(): %.200s", strerror(errno));
1561
Darren Tuckerce321d82005-10-03 18:11:24 +10001562 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1563 sanitise_stdfd();
1564
Damien Miller95def091999-11-25 00:26:21 +11001565 /* Initialize configuration options to their default values. */
1566 initialize_server_options(&options);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001567
Damien Miller95def091999-11-25 00:26:21 +11001568 /* Parse command-line arguments. */
djm@openbsd.org3e91b4e2015-05-24 23:39:16 +00001569 while ((opt = getopt(ac, av,
1570 "C:E:b:c:f:g:h:k:o:p:u:46DQRTdeiqrt")) != -1) {
Damien Miller95def091999-11-25 00:26:21 +11001571 switch (opt) {
Damien Miller34132e52000-01-14 15:45:46 +11001572 case '4':
Darren Tucker0f383232005-01-20 10:57:56 +11001573 options.address_family = AF_INET;
Damien Miller34132e52000-01-14 15:45:46 +11001574 break;
1575 case '6':
Darren Tucker0f383232005-01-20 10:57:56 +11001576 options.address_family = AF_INET6;
Damien Miller34132e52000-01-14 15:45:46 +11001577 break;
Damien Miller95def091999-11-25 00:26:21 +11001578 case 'f':
1579 config_file_name = optarg;
1580 break;
Damien Miller0a80ca12010-02-27 07:55:05 +11001581 case 'c':
1582 if (options.num_host_cert_files >= MAX_HOSTCERTS) {
1583 fprintf(stderr, "too many host certificates.\n");
1584 exit(1);
1585 }
1586 options.host_cert_files[options.num_host_cert_files++] =
1587 derelativise_path(optarg);
1588 break;
Damien Miller95def091999-11-25 00:26:21 +11001589 case 'd':
Darren Tuckere98dfa32003-07-19 19:54:31 +10001590 if (debug_flag == 0) {
Damien Millere4340be2000-09-16 13:29:08 +11001591 debug_flag = 1;
1592 options.log_level = SYSLOG_LEVEL_DEBUG1;
Darren Tuckere98dfa32003-07-19 19:54:31 +10001593 } else if (options.log_level < SYSLOG_LEVEL_DEBUG3)
Damien Millere4340be2000-09-16 13:29:08 +11001594 options.log_level++;
Damien Miller95def091999-11-25 00:26:21 +11001595 break;
Ben Lindstromc72745a2000-12-02 19:03:54 +00001596 case 'D':
1597 no_daemon_flag = 1;
1598 break;
Damien Miller03d4d7e2013-04-23 15:21:06 +10001599 case 'E':
dtucker@openbsd.org4f7cc2f2015-09-04 08:21:47 +00001600 logfile = optarg;
Damien Miller03d4d7e2013-04-23 15:21:06 +10001601 /* FALLTHROUGH */
Ben Lindstrom9fce9f02001-04-11 23:10:09 +00001602 case 'e':
1603 log_stderr = 1;
1604 break;
Damien Miller95def091999-11-25 00:26:21 +11001605 case 'i':
1606 inetd_flag = 1;
1607 break;
Darren Tucker645ab752004-06-25 13:33:20 +10001608 case 'r':
1609 rexec_flag = 0;
1610 break;
1611 case 'R':
1612 rexeced_flag = 1;
1613 inetd_flag = 1;
1614 break;
Damien Miller95def091999-11-25 00:26:21 +11001615 case 'Q':
Ben Lindstromd5390202001-01-29 08:07:43 +00001616 /* ignored */
Damien Miller95def091999-11-25 00:26:21 +11001617 break;
1618 case 'q':
1619 options.log_level = SYSLOG_LEVEL_QUIET;
1620 break;
1621 case 'b':
Damien Millerf0b15df2006-03-26 13:59:20 +11001622 options.server_key_bits = (int)strtonum(optarg, 256,
1623 32768, NULL);
Damien Miller95def091999-11-25 00:26:21 +11001624 break;
1625 case 'p':
Damien Miller34132e52000-01-14 15:45:46 +11001626 options.ports_from_cmdline = 1;
Damien Millere4340be2000-09-16 13:29:08 +11001627 if (options.num_ports >= MAX_PORTS) {
1628 fprintf(stderr, "too many ports.\n");
1629 exit(1);
1630 }
Ben Lindstrom19066a12001-04-12 23:39:26 +00001631 options.ports[options.num_ports++] = a2port(optarg);
Damien Miller3dc71ad2009-01-28 16:31:22 +11001632 if (options.ports[options.num_ports-1] <= 0) {
Ben Lindstrom19066a12001-04-12 23:39:26 +00001633 fprintf(stderr, "Bad port number.\n");
1634 exit(1);
1635 }
Damien Miller95def091999-11-25 00:26:21 +11001636 break;
1637 case 'g':
Ben Lindstrom1bda4c82001-06-05 19:59:08 +00001638 if ((options.login_grace_time = convtime(optarg)) == -1) {
1639 fprintf(stderr, "Invalid login grace time.\n");
1640 exit(1);
1641 }
Damien Miller95def091999-11-25 00:26:21 +11001642 break;
1643 case 'k':
Ben Lindstrom1bda4c82001-06-05 19:59:08 +00001644 if ((options.key_regeneration_time = convtime(optarg)) == -1) {
1645 fprintf(stderr, "Invalid key regeneration interval.\n");
1646 exit(1);
1647 }
Damien Miller95def091999-11-25 00:26:21 +11001648 break;
1649 case 'h':
Damien Miller0bc1bd82000-11-13 22:57:25 +11001650 if (options.num_host_key_files >= MAX_HOSTKEYS) {
1651 fprintf(stderr, "too many host keys.\n");
1652 exit(1);
1653 }
Darren Tucker88b6fb22010-01-13 22:44:29 +11001654 options.host_key_files[options.num_host_key_files++] =
1655 derelativise_path(optarg);
Damien Miller95def091999-11-25 00:26:21 +11001656 break;
Ben Lindstrom794325a2001-08-06 21:09:07 +00001657 case 't':
1658 test_flag = 1;
1659 break;
Darren Tuckere7140f22008-06-10 23:01:51 +10001660 case 'T':
1661 test_flag = 2;
1662 break;
1663 case 'C':
Darren Tuckerfbcf8272012-05-19 19:37:01 +10001664 if (parse_server_match_testspec(connection_info,
1665 optarg) == -1)
1666 exit(1);
Darren Tuckere7140f22008-06-10 23:01:51 +10001667 break;
Damien Miller942da032000-08-18 13:59:06 +10001668 case 'u':
deraadt@openbsd.org087266e2015-01-20 23:14:00 +00001669 utmp_len = (u_int)strtonum(optarg, 0, HOST_NAME_MAX+1+1, NULL);
1670 if (utmp_len > HOST_NAME_MAX+1) {
Ben Lindstrom41daec72002-07-23 21:15:13 +00001671 fprintf(stderr, "Invalid utmp length.\n");
1672 exit(1);
1673 }
Damien Miller942da032000-08-18 13:59:06 +10001674 break;
Ben Lindstromade03f62001-12-06 18:22:17 +00001675 case 'o':
Damien Millerb9997192003-12-17 16:29:22 +11001676 line = xstrdup(optarg);
1677 if (process_server_config_line(&options, line,
Darren Tuckerfbcf8272012-05-19 19:37:01 +10001678 "command-line", 0, NULL, NULL) != 0)
Damien Miller9f0f5c62001-12-21 14:45:46 +11001679 exit(1);
Darren Tuckera627d422013-06-02 07:31:17 +10001680 free(line);
Ben Lindstromade03f62001-12-06 18:22:17 +00001681 break;
Damien Miller95def091999-11-25 00:26:21 +11001682 case '?':
1683 default:
Ben Lindstromade03f62001-12-06 18:22:17 +00001684 usage();
1685 break;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001686 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001687 }
Darren Tucker645ab752004-06-25 13:33:20 +10001688 if (rexeced_flag || inetd_flag)
1689 rexec_flag = 0;
Damien Miller2ee0c432008-03-07 18:31:47 +11001690 if (!test_flag && (rexec_flag && (av[0] == NULL || *av[0] != '/')))
Darren Tucker645ab752004-06-25 13:33:20 +10001691 fatal("sshd re-exec requires execution with an absolute path");
1692 if (rexeced_flag)
Damien Miller035a5b42004-06-26 08:16:31 +10001693 closefrom(REEXEC_MIN_FREE_FD);
1694 else
1695 closefrom(REEXEC_DEVCRYPTO_RESERVED_FD);
Darren Tucker645ab752004-06-25 13:33:20 +10001696
Damien Miller1f0311c2014-05-15 14:24:09 +10001697#ifdef WITH_OPENSSL
Damien Miller4314c2b2010-09-10 11:12:09 +10001698 OpenSSL_add_all_algorithms();
Damien Miller1f0311c2014-05-15 14:24:09 +10001699#endif
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001700
Damien Miller03d4d7e2013-04-23 15:21:06 +10001701 /* If requested, redirect the logs to the specified logfile. */
dtucker@openbsd.org4f7cc2f2015-09-04 08:21:47 +00001702 if (logfile != NULL)
Damien Miller03d4d7e2013-04-23 15:21:06 +10001703 log_redirect_stderr_to(logfile);
Damien Miller34132e52000-01-14 15:45:46 +11001704 /*
1705 * Force logging to stderr until we have loaded the private host
1706 * key (unless started from inetd)
1707 */
Kevin Stevesec84dc12000-12-13 17:45:15 +00001708 log_init(__progname,
Damien Miller5aa5d782002-02-08 22:01:54 +11001709 options.log_level == SYSLOG_LEVEL_NOT_SET ?
1710 SYSLOG_LEVEL_INFO : options.log_level,
1711 options.log_facility == SYSLOG_FACILITY_NOT_SET ?
1712 SYSLOG_FACILITY_AUTH : options.log_facility,
Ben Lindstromc2faa4a2002-11-09 15:50:03 +00001713 log_stderr || !inetd_flag);
Damien Miller34132e52000-01-14 15:45:46 +11001714
Darren Tucker86c093d2004-03-08 22:59:03 +11001715 /*
1716 * Unset KRB5CCNAME, otherwise the user's session may inherit it from
1717 * root's environment
Damien Miller94cf4c82005-07-17 17:04:47 +10001718 */
Darren Tucker9dc6c7d2005-02-02 18:30:33 +11001719 if (getenv("KRB5CCNAME") != NULL)
Tim Ricee3609c92012-02-14 10:03:30 -08001720 (void) unsetenv("KRB5CCNAME");
Darren Tucker9dc6c7d2005-02-02 18:30:33 +11001721
Tim Rice81ed5182002-09-25 17:38:46 -07001722#ifdef _UNICOS
Darren Tucker12984962004-05-24 13:37:13 +10001723 /* Cray can define user privs drop all privs now!
Ben Lindstrom6db66ff2001-08-06 23:29:16 +00001724 * Not needed on PRIV_SU systems!
1725 */
1726 drop_cray_privs();
1727#endif
1728
Darren Tucker645ab752004-06-25 13:33:20 +10001729 sensitive_data.server_key = NULL;
1730 sensitive_data.ssh1_host_key = NULL;
1731 sensitive_data.have_ssh1_key = 0;
1732 sensitive_data.have_ssh2_key = 0;
1733
Darren Tuckere7140f22008-06-10 23:01:51 +10001734 /*
1735 * If we're doing an extended config test, make sure we have all of
1736 * the parameters we need. If we're not doing an extended test,
1737 * do not silently ignore connection test params.
1738 */
Darren Tuckerfbcf8272012-05-19 19:37:01 +10001739 if (test_flag >= 2 && server_match_spec_complete(connection_info) == 0)
Darren Tuckere7140f22008-06-10 23:01:51 +10001740 fatal("user, host and addr are all required when testing "
1741 "Match configs");
Darren Tuckerfbcf8272012-05-19 19:37:01 +10001742 if (test_flag < 2 && server_match_spec_complete(connection_info) >= 0)
Darren Tuckere7140f22008-06-10 23:01:51 +10001743 fatal("Config test connection parameter (-C) provided without "
1744 "test mode (-T)");
1745
Darren Tucker645ab752004-06-25 13:33:20 +10001746 /* Fetch our configuration */
1747 buffer_init(&cfg);
1748 if (rexeced_flag)
Damien Miller035a5b42004-06-26 08:16:31 +10001749 recv_rexec_state(REEXEC_CONFIG_PASS_FD, &cfg);
djm@openbsd.orgdbcc6522015-04-27 00:21:21 +00001750 else if (strcasecmp(config_file_name, "none") != 0)
Darren Tucker645ab752004-06-25 13:33:20 +10001751 load_server_config(config_file_name, &cfg);
1752
Darren Tucker45150472006-07-12 22:34:17 +10001753 parse_server_config(&options, rexeced_flag ? "rexec" : config_file_name,
Darren Tuckerfbcf8272012-05-19 19:37:01 +10001754 &cfg, NULL);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001755
Darren Tuckerc6f82192005-09-27 22:46:32 +10001756 seed_rng();
1757
Damien Miller95def091999-11-25 00:26:21 +11001758 /* Fill in default values for those options not explicitly set. */
1759 fill_default_server_options(&options);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001760
Darren Tucker97b1bb52007-03-21 20:38:53 +11001761 /* challenge-response is implemented via keyboard interactive */
1762 if (options.challenge_response_authentication)
1763 options.kbd_interactive_authentication = 1;
1764
Damien Millerd0d10992012-11-04 22:23:14 +11001765 /* Check that options are sensible */
1766 if (options.authorized_keys_command_user == NULL &&
1767 (options.authorized_keys_command != NULL &&
1768 strcasecmp(options.authorized_keys_command, "none") != 0))
1769 fatal("AuthorizedKeysCommand set without "
1770 "AuthorizedKeysCommandUser");
djm@openbsd.orgbcc50d82015-05-21 06:43:30 +00001771 if (options.authorized_principals_command_user == NULL &&
1772 (options.authorized_principals_command != NULL &&
1773 strcasecmp(options.authorized_principals_command, "none") != 0))
1774 fatal("AuthorizedPrincipalsCommand set without "
1775 "AuthorizedPrincipalsCommandUser");
Damien Millerd0d10992012-11-04 22:23:14 +11001776
Damien Millera6e3f012012-11-04 23:21:40 +11001777 /*
1778 * Check whether there is any path through configured auth methods.
1779 * Unfortunately it is not possible to verify this generally before
1780 * daemonisation in the presence of Match block, but this catches
1781 * and warns for trivial misconfigurations that could break login.
1782 */
1783 if (options.num_auth_methods != 0) {
1784 if ((options.protocol & SSH_PROTO_1))
1785 fatal("AuthenticationMethods is not supported with "
1786 "SSH protocol 1");
1787 for (n = 0; n < options.num_auth_methods; n++) {
1788 if (auth2_methods_valid(options.auth_methods[n],
1789 1) == 0)
1790 break;
1791 }
1792 if (n >= options.num_auth_methods)
1793 fatal("AuthenticationMethods cannot be satisfied by "
1794 "enabled authentication methods");
1795 }
1796
Darren Tucker7bd98e72010-01-10 10:31:12 +11001797 /* set default channel AF */
Darren Tucker0f383232005-01-20 10:57:56 +11001798 channel_set_af(options.address_family);
1799
Damien Miller95def091999-11-25 00:26:21 +11001800 /* Check that there are no remaining arguments. */
1801 if (optind < ac) {
1802 fprintf(stderr, "Extra argument %s.\n", av[optind]);
1803 exit(1);
1804 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001805
Damien Miller22e8a1e2013-02-12 11:04:48 +11001806 debug("sshd version %s, %s", SSH_VERSION,
Damien Miller1f0311c2014-05-15 14:24:09 +10001807#ifdef WITH_OPENSSL
1808 SSLeay_version(SSLEAY_VERSION)
1809#else
1810 "without OpenSSL"
1811#endif
1812 );
Damien Miller2ccf6611999-11-15 15:25:10 +11001813
Darren Tuckerdf0e4382006-11-07 11:28:40 +11001814 /* Store privilege separation user for later use if required. */
1815 if ((privsep_pw = getpwnam(SSH_PRIVSEP_USER)) == NULL) {
1816 if (use_privsep || options.kerberos_authentication)
1817 fatal("Privilege separation user %s does not exist",
1818 SSH_PRIVSEP_USER);
1819 } else {
Damien Millera5103f42014-02-04 11:20:14 +11001820 explicit_bzero(privsep_pw->pw_passwd,
1821 strlen(privsep_pw->pw_passwd));
Darren Tuckerdf0e4382006-11-07 11:28:40 +11001822 privsep_pw = pwcopy(privsep_pw);
Darren Tuckerf60845f2013-06-02 08:07:31 +10001823 free(privsep_pw->pw_passwd);
Darren Tuckerdf0e4382006-11-07 11:28:40 +11001824 privsep_pw->pw_passwd = xstrdup("*");
1825 }
Damien Miller6433df02006-09-07 10:36:43 +10001826 endpwent();
1827
Damien Miller85b45e02013-07-20 13:21:52 +10001828 /* load host keys */
Damien Miller07d86be2006-03-26 14:19:21 +11001829 sensitive_data.host_keys = xcalloc(options.num_host_key_files,
Ben Lindstroma962c2f2002-07-04 00:14:17 +00001830 sizeof(Key *));
Damien Miller85b45e02013-07-20 13:21:52 +10001831 sensitive_data.host_pubkeys = xcalloc(options.num_host_key_files,
1832 sizeof(Key *));
Damien Miller85b45e02013-07-20 13:21:52 +10001833
1834 if (options.host_key_agent) {
1835 if (strcmp(options.host_key_agent, SSH_AUTHSOCKET_ENV_NAME))
1836 setenv(SSH_AUTHSOCKET_ENV_NAME,
1837 options.host_key_agent, 1);
djm@openbsd.org83f8ffa2015-01-17 18:53:34 +00001838 if ((r = ssh_get_authentication_socket(NULL)) == 0)
1839 have_agent = 1;
1840 else
1841 error("Could not connect to agent \"%s\": %s",
1842 options.host_key_agent, ssh_err(r));
Damien Miller85b45e02013-07-20 13:21:52 +10001843 }
Damien Millereba71ba2000-04-29 23:57:08 +10001844
Damien Miller9f0f5c62001-12-21 14:45:46 +11001845 for (i = 0; i < options.num_host_key_files; i++) {
djm@openbsd.org161cf412014-12-22 07:55:51 +00001846 if (options.host_key_files[i] == NULL)
1847 continue;
Ben Lindstromd0fca422001-03-26 13:44:06 +00001848 key = key_load_private(options.host_key_files[i], "", NULL);
Damien Miller85b45e02013-07-20 13:21:52 +10001849 pubkey = key_load_public(options.host_key_files[i], NULL);
djm@openbsd.org8d4f8722015-01-26 03:04:45 +00001850 if (pubkey == NULL && key != NULL)
1851 pubkey = key_demote(key);
Ben Lindstromd0fca422001-03-26 13:44:06 +00001852 sensitive_data.host_keys[i] = key;
Damien Miller85b45e02013-07-20 13:21:52 +10001853 sensitive_data.host_pubkeys[i] = pubkey;
1854
djm@openbsd.orgce63c4b2015-02-16 22:30:03 +00001855 if (key == NULL && pubkey != NULL && pubkey->type != KEY_RSA1 &&
1856 have_agent) {
1857 debug("will rely on agent for hostkey %s",
1858 options.host_key_files[i]);
Damien Miller85b45e02013-07-20 13:21:52 +10001859 keytype = pubkey->type;
1860 } else if (key != NULL) {
1861 keytype = key->type;
1862 } else {
Ben Lindstrom15f33862001-04-16 02:00:02 +00001863 error("Could not load host key: %s",
1864 options.host_key_files[i]);
Ben Lindstromd0fca422001-03-26 13:44:06 +00001865 sensitive_data.host_keys[i] = NULL;
Damien Miller85b45e02013-07-20 13:21:52 +10001866 sensitive_data.host_pubkeys[i] = NULL;
Damien Miller0bc1bd82000-11-13 22:57:25 +11001867 continue;
1868 }
Damien Miller85b45e02013-07-20 13:21:52 +10001869
1870 switch (keytype) {
Damien Miller0bc1bd82000-11-13 22:57:25 +11001871 case KEY_RSA1:
1872 sensitive_data.ssh1_host_key = key;
1873 sensitive_data.have_ssh1_key = 1;
1874 break;
1875 case KEY_RSA:
1876 case KEY_DSA:
Damien Millereb8b60e2010-08-31 22:41:14 +10001877 case KEY_ECDSA:
Damien Miller5be9d9e2013-12-07 11:24:01 +11001878 case KEY_ED25519:
djm@openbsd.org6049a542015-01-31 20:30:05 +00001879 if (have_agent || key != NULL)
1880 sensitive_data.have_ssh2_key = 1;
Damien Miller0bc1bd82000-11-13 22:57:25 +11001881 break;
1882 }
djm@openbsd.org6049a542015-01-31 20:30:05 +00001883 if ((fp = sshkey_fingerprint(pubkey, options.fingerprint_hash,
1884 SSH_FP_DEFAULT)) == NULL)
1885 fatal("sshkey_fingerprint failed");
1886 debug("%s host key #%d: %s %s",
djm@openbsd.orgce63c4b2015-02-16 22:30:03 +00001887 key ? "private" : "agent", i, keytype == KEY_RSA1 ?
djm@openbsd.org6049a542015-01-31 20:30:05 +00001888 sshkey_type(pubkey) : sshkey_ssh_name(pubkey), fp);
1889 free(fp);
Damien Miller0bc1bd82000-11-13 22:57:25 +11001890 }
1891 if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) {
Damien Miller996acd22003-04-09 20:59:48 +10001892 logit("Disabling protocol version 1. Could not load host key");
Damien Millereba71ba2000-04-29 23:57:08 +10001893 options.protocol &= ~SSH_PROTO_1;
1894 }
Damien Miller0bc1bd82000-11-13 22:57:25 +11001895 if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) {
Damien Miller996acd22003-04-09 20:59:48 +10001896 logit("Disabling protocol version 2. Could not load host key");
Damien Miller0bc1bd82000-11-13 22:57:25 +11001897 options.protocol &= ~SSH_PROTO_2;
Damien Millereba71ba2000-04-29 23:57:08 +10001898 }
Kevin Stevesadf74cd2001-02-05 14:22:50 +00001899 if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
Damien Miller996acd22003-04-09 20:59:48 +10001900 logit("sshd: no hostkeys available -- exiting.");
Damien Miller95def091999-11-25 00:26:21 +11001901 exit(1);
1902 }
Damien Miller95def091999-11-25 00:26:21 +11001903
Damien Miller0a80ca12010-02-27 07:55:05 +11001904 /*
1905 * Load certificates. They are stored in an array at identical
1906 * indices to the public keys that they relate to.
1907 */
1908 sensitive_data.host_certificates = xcalloc(options.num_host_key_files,
1909 sizeof(Key *));
1910 for (i = 0; i < options.num_host_key_files; i++)
1911 sensitive_data.host_certificates[i] = NULL;
1912
1913 for (i = 0; i < options.num_host_cert_files; i++) {
djm@openbsd.org161cf412014-12-22 07:55:51 +00001914 if (options.host_cert_files[i] == NULL)
1915 continue;
Damien Miller0a80ca12010-02-27 07:55:05 +11001916 key = key_load_public(options.host_cert_files[i], NULL);
1917 if (key == NULL) {
1918 error("Could not load host certificate: %s",
1919 options.host_cert_files[i]);
1920 continue;
1921 }
1922 if (!key_is_cert(key)) {
1923 error("Certificate file is not a certificate: %s",
1924 options.host_cert_files[i]);
1925 key_free(key);
1926 continue;
1927 }
1928 /* Find matching private key */
1929 for (j = 0; j < options.num_host_key_files; j++) {
1930 if (key_equal_public(key,
1931 sensitive_data.host_keys[j])) {
1932 sensitive_data.host_certificates[j] = key;
1933 break;
1934 }
1935 }
1936 if (j >= options.num_host_key_files) {
1937 error("No matching private key for certificate: %s",
1938 options.host_cert_files[i]);
1939 key_free(key);
1940 continue;
1941 }
1942 sensitive_data.host_certificates[j] = key;
1943 debug("host certificate: #%d type %d %s", j, key->type,
1944 key_type(key));
1945 }
Damien Miller1f0311c2014-05-15 14:24:09 +10001946
1947#ifdef WITH_SSH1
Damien Millereba71ba2000-04-29 23:57:08 +10001948 /* Check certain values for sanity. */
1949 if (options.protocol & SSH_PROTO_1) {
djm@openbsd.org933935c2015-07-03 03:49:45 +00001950 if (options.server_key_bits < SSH_RSA_MINIMUM_MODULUS_SIZE ||
1951 options.server_key_bits > OPENSSL_RSA_MAX_MODULUS_BITS) {
Damien Millereba71ba2000-04-29 23:57:08 +10001952 fprintf(stderr, "Bad server key size.\n");
1953 exit(1);
1954 }
1955 /*
1956 * Check that server and host key lengths differ sufficiently. This
1957 * is necessary to make double encryption work with rsaref. Oh, I
1958 * hate software patents. I dont know if this can go? Niels
1959 */
1960 if (options.server_key_bits >
Ben Lindstrom822b6342002-06-23 21:38:49 +00001961 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) -
1962 SSH_KEY_BITS_RESERVED && options.server_key_bits <
1963 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
1964 SSH_KEY_BITS_RESERVED) {
Damien Millereba71ba2000-04-29 23:57:08 +10001965 options.server_key_bits =
Ben Lindstrom822b6342002-06-23 21:38:49 +00001966 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
1967 SSH_KEY_BITS_RESERVED;
Damien Millereba71ba2000-04-29 23:57:08 +10001968 debug("Forcing server key to %d bits to make it differ from host key.",
1969 options.server_key_bits);
1970 }
1971 }
Damien Miller1f0311c2014-05-15 14:24:09 +10001972#endif
Damien Millereba71ba2000-04-29 23:57:08 +10001973
Ben Lindstroma26ea632002-06-06 20:46:25 +00001974 if (use_privsep) {
Ben Lindstroma26ea632002-06-06 20:46:25 +00001975 struct stat st;
1976
Ben Lindstroma26ea632002-06-06 20:46:25 +00001977 if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) ||
1978 (S_ISDIR(st.st_mode) == 0))
1979 fatal("Missing privilege separation directory: %s",
1980 _PATH_PRIVSEP_CHROOT_DIR);
Ben Lindstrom59627352002-06-27 18:02:21 +00001981
1982#ifdef HAVE_CYGWIN
1983 if (check_ntsec(_PATH_PRIVSEP_CHROOT_DIR) &&
1984 (st.st_uid != getuid () ||
1985 (st.st_mode & (S_IWGRP|S_IWOTH)) != 0))
1986#else
Ben Lindstrom2dfacb32002-06-23 00:33:47 +00001987 if (st.st_uid != 0 || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)
Ben Lindstrom59627352002-06-27 18:02:21 +00001988#endif
Damien Miller180fc5b2003-02-24 11:50:18 +11001989 fatal("%s must be owned by root and not group or "
1990 "world-writable.", _PATH_PRIVSEP_CHROOT_DIR);
Ben Lindstroma26ea632002-06-06 20:46:25 +00001991 }
1992
Darren Tuckere7140f22008-06-10 23:01:51 +10001993 if (test_flag > 1) {
Darren Tuckerfbcf8272012-05-19 19:37:01 +10001994 if (server_match_spec_complete(connection_info) == 1)
1995 parse_server_match_config(&options, connection_info);
Darren Tuckere7140f22008-06-10 23:01:51 +10001996 dump_config(&options);
1997 }
1998
Ben Lindstrom794325a2001-08-06 21:09:07 +00001999 /* Configuration looks good, so exit if in test mode. */
2000 if (test_flag)
2001 exit(0);
2002
Damien Miller87aea252002-05-10 12:20:24 +10002003 /*
2004 * Clear out any supplemental groups we may have inherited. This
2005 * prevents inadvertent creation of files with bad modes (in the
Damien Millera8e06ce2003-11-21 23:48:55 +11002006 * portable version at least, it's certainly possible for PAM
2007 * to create a file, and we can't control the code in every
Damien Miller87aea252002-05-10 12:20:24 +10002008 * module which might be used).
2009 */
2010 if (setgroups(0, NULL) < 0)
2011 debug("setgroups() failed: %.200s", strerror(errno));
2012
Darren Tucker645ab752004-06-25 13:33:20 +10002013 if (rexec_flag) {
Damien Miller07d86be2006-03-26 14:19:21 +11002014 rexec_argv = xcalloc(rexec_argc + 2, sizeof(char *));
Darren Tucker645ab752004-06-25 13:33:20 +10002015 for (i = 0; i < rexec_argc; i++) {
2016 debug("rexec_argv[%d]='%s'", i, saved_argv[i]);
2017 rexec_argv[i] = saved_argv[i];
2018 }
2019 rexec_argv[rexec_argc] = "-R";
2020 rexec_argv[rexec_argc + 1] = NULL;
2021 }
2022
Damien Miller6ca16c62008-06-16 07:50:58 +10002023 /* Ensure that umask disallows at least group and world write */
2024 new_umask = umask(0077) | 0022;
2025 (void) umask(new_umask);
2026
Damien Millereba71ba2000-04-29 23:57:08 +10002027 /* Initialize the log (it is reinitialized below in case we forked). */
Darren Tuckerea7c8122005-01-20 11:03:08 +11002028 if (debug_flag && (!inetd_flag || rexeced_flag))
Damien Miller95def091999-11-25 00:26:21 +11002029 log_stderr = 1;
Kevin Stevesec84dc12000-12-13 17:45:15 +00002030 log_init(__progname, options.log_level, options.log_facility, log_stderr);
Damien Miller95def091999-11-25 00:26:21 +11002031
Damien Millereba71ba2000-04-29 23:57:08 +10002032 /*
2033 * If not in debugging mode, and not started from inetd, disconnect
2034 * from the controlling terminal, and fork. The original process
2035 * exits.
2036 */
Ben Lindstromc72745a2000-12-02 19:03:54 +00002037 if (!(debug_flag || inetd_flag || no_daemon_flag)) {
Damien Miller95def091999-11-25 00:26:21 +11002038#ifdef TIOCNOTTY
2039 int fd;
2040#endif /* TIOCNOTTY */
2041 if (daemon(0, 0) < 0)
2042 fatal("daemon() failed: %.200s", strerror(errno));
2043
2044 /* Disconnect from the controlling tty. */
2045#ifdef TIOCNOTTY
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00002046 fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
Damien Miller95def091999-11-25 00:26:21 +11002047 if (fd >= 0) {
2048 (void) ioctl(fd, TIOCNOTTY, NULL);
2049 close(fd);
2050 }
2051#endif /* TIOCNOTTY */
2052 }
2053 /* Reinitialize the log (because of the fork above). */
Kevin Stevesec84dc12000-12-13 17:45:15 +00002054 log_init(__progname, options.log_level, options.log_facility, log_stderr);
Damien Miller95def091999-11-25 00:26:21 +11002055
Damien Miller95def091999-11-25 00:26:21 +11002056 /* Chdir to the root directory so that the current disk can be
2057 unmounted if desired. */
Darren Tuckerdbee3082013-05-16 20:32:29 +10002058 if (chdir("/") == -1)
2059 error("chdir(\"/\"): %s", strerror(errno));
Damien Miller9f0f5c62001-12-21 14:45:46 +11002060
Ben Lindstromde71cda2001-03-24 00:43:26 +00002061 /* ignore SIGPIPE */
2062 signal(SIGPIPE, SIG_IGN);
Damien Miller95def091999-11-25 00:26:21 +11002063
Damien Millera1f68402006-08-19 00:31:39 +10002064 /* Get a connection, either from inetd or a listening TCP socket */
Damien Miller95def091999-11-25 00:26:21 +11002065 if (inetd_flag) {
Damien Millera1f68402006-08-19 00:31:39 +10002066 server_accept_inetd(&sock_in, &sock_out);
Damien Miller95def091999-11-25 00:26:21 +11002067 } else {
Darren Tuckerc8802aa2009-12-08 13:39:48 +11002068 platform_pre_listen();
Damien Millera1f68402006-08-19 00:31:39 +10002069 server_listen();
Damien Miller34132e52000-01-14 15:45:46 +11002070
Ben Lindstrom98097862001-06-25 05:10:20 +00002071 if (options.protocol & SSH_PROTO_1)
2072 generate_ephemeral_server_key();
2073
Ben Lindstrom98097862001-06-25 05:10:20 +00002074 signal(SIGHUP, sighup_handler);
Damien Millera1f68402006-08-19 00:31:39 +10002075 signal(SIGCHLD, main_sigchld_handler);
Ben Lindstrom98097862001-06-25 05:10:20 +00002076 signal(SIGTERM, sigterm_handler);
2077 signal(SIGQUIT, sigterm_handler);
2078
Damien Millera1f68402006-08-19 00:31:39 +10002079 /*
2080 * Write out the pid file after the sigterm handler
2081 * is setup and the listen sockets are bound
2082 */
djm@openbsd.org161cf412014-12-22 07:55:51 +00002083 if (options.pid_file != NULL && !debug_flag) {
Damien Millera1f68402006-08-19 00:31:39 +10002084 FILE *f = fopen(options.pid_file, "w");
2085
Darren Tuckere5327042003-07-03 13:40:44 +10002086 if (f == NULL) {
2087 error("Couldn't create pid file \"%s\": %s",
2088 options.pid_file, strerror(errno));
2089 } else {
Ben Lindstromce0f6342002-06-11 16:42:49 +00002090 fprintf(f, "%ld\n", (long) getpid());
Damien Miller95def091999-11-25 00:26:21 +11002091 fclose(f);
2092 }
2093 }
Damien Miller95def091999-11-25 00:26:21 +11002094
Damien Millera1f68402006-08-19 00:31:39 +10002095 /* Accept a connection and return in a forked child */
2096 server_accept_loop(&sock_in, &sock_out,
2097 &newsock, config_s);
Damien Miller95def091999-11-25 00:26:21 +11002098 }
2099
2100 /* This is the child processing a new connection. */
Damien Miller57aae982004-03-08 23:11:25 +11002101 setproctitle("%s", "[accepted]");
Damien Miller95def091999-11-25 00:26:21 +11002102
Darren Tucker6832b832004-08-12 22:36:51 +10002103 /*
2104 * Create a new session and process group since the 4.4BSD
2105 * setlogin() affects the entire process group. We don't
2106 * want the child to be able to affect the parent.
2107 */
2108#if !defined(SSHD_ACQUIRES_CTTY)
2109 /*
2110 * If setsid is called, on some platforms sshd will later acquire a
2111 * controlling terminal which will result in "could not set
2112 * controlling tty" errors.
2113 */
2114 if (!debug_flag && !inetd_flag && setsid() < 0)
2115 error("setsid: %.100s", strerror(errno));
2116#endif
2117
Darren Tucker645ab752004-06-25 13:33:20 +10002118 if (rexec_flag) {
2119 int fd;
2120
Damien Miller035a5b42004-06-26 08:16:31 +10002121 debug("rexec start in %d out %d newsock %d pipe %d sock %d",
2122 sock_in, sock_out, newsock, startup_pipe, config_s[0]);
Darren Tucker645ab752004-06-25 13:33:20 +10002123 dup2(newsock, STDIN_FILENO);
2124 dup2(STDIN_FILENO, STDOUT_FILENO);
2125 if (startup_pipe == -1)
Damien Miller035a5b42004-06-26 08:16:31 +10002126 close(REEXEC_STARTUP_PIPE_FD);
Damien Miller61ee4d62013-10-15 11:56:47 +11002127 else if (startup_pipe != REEXEC_STARTUP_PIPE_FD) {
Damien Miller035a5b42004-06-26 08:16:31 +10002128 dup2(startup_pipe, REEXEC_STARTUP_PIPE_FD);
Damien Miller61ee4d62013-10-15 11:56:47 +11002129 close(startup_pipe);
2130 startup_pipe = REEXEC_STARTUP_PIPE_FD;
2131 }
Darren Tucker645ab752004-06-25 13:33:20 +10002132
Damien Miller035a5b42004-06-26 08:16:31 +10002133 dup2(config_s[1], REEXEC_CONFIG_PASS_FD);
Darren Tucker645ab752004-06-25 13:33:20 +10002134 close(config_s[1]);
Damien Miller035a5b42004-06-26 08:16:31 +10002135
Darren Tucker645ab752004-06-25 13:33:20 +10002136 execv(rexec_argv[0], rexec_argv);
2137
2138 /* Reexec has failed, fall back and continue */
2139 error("rexec of %s failed: %s", rexec_argv[0], strerror(errno));
Damien Miller035a5b42004-06-26 08:16:31 +10002140 recv_rexec_state(REEXEC_CONFIG_PASS_FD, NULL);
Darren Tucker645ab752004-06-25 13:33:20 +10002141 log_init(__progname, options.log_level,
2142 options.log_facility, log_stderr);
2143
2144 /* Clean up fds */
Damien Miller035a5b42004-06-26 08:16:31 +10002145 close(REEXEC_CONFIG_PASS_FD);
2146 newsock = sock_out = sock_in = dup(STDIN_FILENO);
Darren Tucker645ab752004-06-25 13:33:20 +10002147 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
2148 dup2(fd, STDIN_FILENO);
2149 dup2(fd, STDOUT_FILENO);
2150 if (fd > STDERR_FILENO)
2151 close(fd);
2152 }
Damien Miller035a5b42004-06-26 08:16:31 +10002153 debug("rexec cleanup in %d out %d newsock %d pipe %d sock %d",
2154 sock_in, sock_out, newsock, startup_pipe, config_s[0]);
Darren Tucker645ab752004-06-25 13:33:20 +10002155 }
2156
Damien Miller133d9d32010-01-30 17:30:04 +11002157 /* Executed child processes don't need these. */
2158 fcntl(sock_out, F_SETFD, FD_CLOEXEC);
2159 fcntl(sock_in, F_SETFD, FD_CLOEXEC);
2160
Damien Miller5428f641999-11-25 11:54:57 +11002161 /*
2162 * Disable the key regeneration alarm. We will not regenerate the
2163 * key since we are no longer in a position to give it to anyone. We
2164 * will not restart on SIGHUP since it no longer makes sense.
2165 */
Damien Miller95def091999-11-25 00:26:21 +11002166 alarm(0);
2167 signal(SIGALRM, SIG_DFL);
2168 signal(SIGHUP, SIG_DFL);
2169 signal(SIGTERM, SIG_DFL);
2170 signal(SIGQUIT, SIG_DFL);
2171 signal(SIGCHLD, SIG_DFL);
Damien Miller4e0f5e12000-08-29 11:05:50 +11002172 signal(SIGINT, SIG_DFL);
Damien Miller95def091999-11-25 00:26:21 +11002173
Damien Miller5428f641999-11-25 11:54:57 +11002174 /*
2175 * Register our connection. This turns encryption off because we do
2176 * not have a key.
2177 */
Damien Miller95def091999-11-25 00:26:21 +11002178 packet_set_connection(sock_in, sock_out);
Damien Miller9786e6e2005-07-26 21:54:56 +10002179 packet_set_server();
djm@openbsd.org95767262016-03-07 19:02:43 +00002180 ssh = active_state; /* XXX */
2181 check_ip_options(ssh);
Damien Miller95def091999-11-25 00:26:21 +11002182
Damien Miller4f1d6b22005-05-26 11:59:32 +10002183 /* Set SO_KEEPALIVE if requested. */
2184 if (options.tcp_keep_alive && packet_connection_is_on_socket() &&
2185 setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) < 0)
2186 error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
2187
djm@openbsd.org95767262016-03-07 19:02:43 +00002188 if ((remote_port = ssh_remote_port(ssh)) < 0) {
2189 debug("ssh_remote_port failed");
Damien Miller677257f2005-06-17 12:55:03 +10002190 cleanup_exit(255);
2191 }
Damien Miller4d3fd542005-11-05 15:13:24 +11002192
2193 /*
Damien Millereb13e552006-06-13 13:03:53 +10002194 * The rest of the code depends on the fact that
djm@openbsd.org95767262016-03-07 19:02:43 +00002195 * ssh_remote_ipaddr() caches the remote ip, even if
Damien Millereb13e552006-06-13 13:03:53 +10002196 * the socket goes away.
2197 */
djm@openbsd.org95767262016-03-07 19:02:43 +00002198 remote_ip = ssh_remote_ipaddr(ssh);
Damien Miller95def091999-11-25 00:26:21 +11002199
Darren Tucker2e0cf0d2005-02-08 21:52:47 +11002200#ifdef SSH_AUDIT_EVENTS
Darren Tucker269a1ea2005-02-03 00:20:53 +11002201 audit_connection_from(remote_ip, remote_port);
2202#endif
Damien Miller6a4a4b92001-11-12 11:07:11 +11002203
Damien Miller95def091999-11-25 00:26:21 +11002204 /* Log the connection. */
dtucker@openbsd.org15fdfc92015-04-15 23:23:25 +00002205 laddr = get_local_ipaddr(sock_in);
Damien Miller5ecb4162013-10-24 21:02:02 +11002206 verbose("Connection from %s port %d on %s port %d",
djm@openbsd.org95767262016-03-07 19:02:43 +00002207 remote_ip, remote_port, laddr, ssh_local_port(ssh));
dtucker@openbsd.org15fdfc92015-04-15 23:23:25 +00002208 free(laddr);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002209
Damien Miller5428f641999-11-25 11:54:57 +11002210 /*
Damien Miller788f2122005-11-05 15:14:59 +11002211 * We don't want to listen forever unless the other side
Damien Miller5428f641999-11-25 11:54:57 +11002212 * successfully authenticates itself. So we set up an alarm which is
2213 * cleared after successful authentication. A limit of zero
Damien Miller788f2122005-11-05 15:14:59 +11002214 * indicates no limit. Note that we don't set the alarm in debugging
Damien Miller5428f641999-11-25 11:54:57 +11002215 * mode; it is just annoying to have the server exit just when you
2216 * are about to discover the bug.
2217 */
Ben Lindstrom5ade9ab2003-08-25 01:16:21 +00002218 signal(SIGALRM, grace_alarm_handler);
Damien Miller95def091999-11-25 00:26:21 +11002219 if (!debug_flag)
2220 alarm(options.login_grace_time);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002221
djm@openbsd.org95767262016-03-07 19:02:43 +00002222 sshd_exchange_identification(ssh, sock_in, sock_out);
Darren Tuckerec960f22003-08-13 20:37:05 +10002223
Darren Tucker58911162008-01-01 20:33:09 +11002224 /* In inetd mode, generate ephemeral key only for proto 1 connections */
2225 if (!compat20 && inetd_flag && sensitive_data.server_key == NULL)
2226 generate_ephemeral_server_key();
2227
Damien Miller95def091999-11-25 00:26:21 +11002228 packet_set_nonblocking();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002229
Darren Tucker3e33cec2003-10-02 16:12:36 +10002230 /* allocate authentication context */
Damien Miller07d86be2006-03-26 14:19:21 +11002231 authctxt = xcalloc(1, sizeof(*authctxt));
Darren Tucker3e33cec2003-10-02 16:12:36 +10002232
Darren Tuckerf3bb4342005-03-31 21:39:25 +10002233 authctxt->loginmsg = &loginmsg;
2234
Darren Tucker3e33cec2003-10-02 16:12:36 +10002235 /* XXX global for cleanup, access from other modules */
2236 the_authctxt = authctxt;
2237
Darren Tucker5c14c732005-01-24 21:55:49 +11002238 /* prepare buffer to collect messages to display to user after login */
2239 buffer_init(&loginmsg);
Darren Tuckercd70e1b2010-03-07 23:05:17 +11002240 auth_debug_reset();
Darren Tucker5c14c732005-01-24 21:55:49 +11002241
Damien Miller85b45e02013-07-20 13:21:52 +10002242 if (use_privsep) {
Darren Tucker3e33cec2003-10-02 16:12:36 +10002243 if (privsep_preauth(authctxt) == 1)
Ben Lindstrom943481c2002-03-22 03:43:46 +00002244 goto authenticated;
djm@openbsd.org141efe42015-01-14 20:05:27 +00002245 } else if (compat20 && have_agent) {
2246 if ((r = ssh_get_authentication_socket(&auth_sock)) != 0) {
2247 error("Unable to get agent socket: %s", ssh_err(r));
djm@openbsd.org83f8ffa2015-01-17 18:53:34 +00002248 have_agent = 0;
djm@openbsd.org141efe42015-01-14 20:05:27 +00002249 }
2250 }
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002251
Damien Miller396691a2000-01-20 22:44:08 +11002252 /* perform the key exchange */
Damien Miller396691a2000-01-20 22:44:08 +11002253 /* authenticate user and start session */
Damien Millerefb4afe2000-04-12 18:45:05 +10002254 if (compat20) {
2255 do_ssh2_kex();
Darren Tucker3e33cec2003-10-02 16:12:36 +10002256 do_authentication2(authctxt);
Damien Millerefb4afe2000-04-12 18:45:05 +10002257 } else {
Damien Miller1f0311c2014-05-15 14:24:09 +10002258#ifdef WITH_SSH1
Damien Millerefb4afe2000-04-12 18:45:05 +10002259 do_ssh1_kex();
Darren Tucker3e33cec2003-10-02 16:12:36 +10002260 do_authentication(authctxt);
Damien Miller1f0311c2014-05-15 14:24:09 +10002261#else
2262 fatal("ssh1 not supported");
2263#endif
Damien Millerefb4afe2000-04-12 18:45:05 +10002264 }
Ben Lindstrom943481c2002-03-22 03:43:46 +00002265 /*
2266 * If we use privilege separation, the unprivileged child transfers
2267 * the current keystate and exits
2268 */
2269 if (use_privsep) {
Ben Lindstrom7339b2a2002-05-15 16:25:01 +00002270 mm_send_keystate(pmonitor);
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002271 exit(0);
Ben Lindstrom943481c2002-03-22 03:43:46 +00002272 }
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002273
2274 authenticated:
Damien Miller7bff1a92005-12-24 14:59:12 +11002275 /*
2276 * Cancel the alarm we set to limit the time taken for
2277 * authentication.
2278 */
2279 alarm(0);
2280 signal(SIGALRM, SIG_DFL);
Damien Miller3f8123c2006-08-19 00:32:46 +10002281 authctxt->authenticated = 1;
Damien Miller7bff1a92005-12-24 14:59:12 +11002282 if (startup_pipe != -1) {
2283 close(startup_pipe);
2284 startup_pipe = -1;
2285 }
2286
Darren Tucker2e0cf0d2005-02-08 21:52:47 +11002287#ifdef SSH_AUDIT_EVENTS
2288 audit_event(SSH_AUTH_SUCCESS);
Darren Tucker269a1ea2005-02-03 00:20:53 +11002289#endif
2290
Darren Tucker52358d62008-03-11 22:58:25 +11002291#ifdef GSSAPI
2292 if (options.gss_authentication) {
2293 temporarily_use_uid(authctxt->pw);
2294 ssh_gssapi_storecreds();
2295 restore_uid();
2296 }
2297#endif
2298#ifdef USE_PAM
2299 if (options.use_pam) {
2300 do_pam_setcred(1);
2301 do_pam_session();
2302 }
2303#endif
2304
Ben Lindstrom6328ab32002-03-22 02:54:23 +00002305 /*
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002306 * In privilege separation, we fork another child and prepare
2307 * file descriptor passing.
2308 */
2309 if (use_privsep) {
Ben Lindstrom943481c2002-03-22 03:43:46 +00002310 privsep_postauth(authctxt);
2311 /* the monitor process [priv] will not return */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002312 if (!compat20)
2313 destroy_sensitive_data();
2314 }
Ben Lindstrom73ab9ba2002-03-22 01:27:35 +00002315
Darren Tucker3fc464e2008-06-13 06:42:45 +10002316 packet_set_timeout(options.client_alive_interval,
2317 options.client_alive_count_max);
2318
djm@openbsd.org8d4f8722015-01-26 03:04:45 +00002319 /* Try to send all our hostkeys to the client */
2320 if (compat20)
2321 notify_hostkeys(active_state);
2322
Darren Tucker3e33cec2003-10-02 16:12:36 +10002323 /* Start session. */
Ben Lindstrom73ab9ba2002-03-22 01:27:35 +00002324 do_authenticated(authctxt);
2325
Damien Miller3a5b0232002-03-13 13:19:42 +11002326 /* The connection has been terminated. */
markus@openbsd.org091c3022015-01-19 19:52:16 +00002327 packet_get_bytes(&ibytes, &obytes);
Damien Miller821de0a2011-01-11 17:20:29 +11002328 verbose("Transferred: sent %llu, received %llu bytes",
2329 (unsigned long long)obytes, (unsigned long long)ibytes);
Damien Millerb61f3fc2008-07-11 17:36:48 +10002330
2331 verbose("Closing connection to %.500s port %d", remote_ip, remote_port);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002332
Damien Millerbeb4ba51999-12-28 15:09:35 +11002333#ifdef USE_PAM
Damien Miller4e448a32003-05-14 15:11:48 +10002334 if (options.use_pam)
2335 finish_pam();
Damien Millerbeb4ba51999-12-28 15:09:35 +11002336#endif /* USE_PAM */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002337
Darren Tucker2b59a6d2005-03-06 22:38:51 +11002338#ifdef SSH_AUDIT_EVENTS
2339 PRIVSEP(audit_event(SSH_CONNECTION_CLOSE));
2340#endif
2341
Damien Miller95def091999-11-25 00:26:21 +11002342 packet_close();
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002343
2344 if (use_privsep)
2345 mm_terminate();
2346
Damien Miller95def091999-11-25 00:26:21 +11002347 exit(0);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002348}
2349
Damien Miller1f0311c2014-05-15 14:24:09 +10002350#ifdef WITH_SSH1
Damien Miller95def091999-11-25 00:26:21 +11002351/*
Ben Lindstromabcb1452002-03-22 01:10:21 +00002352 * Decrypt session_key_int using our private server key and private host key
2353 * (key with larger modulus first).
2354 */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002355int
Ben Lindstromabcb1452002-03-22 01:10:21 +00002356ssh1_session_key(BIGNUM *session_key_int)
2357{
djm@openbsd.org95767262016-03-07 19:02:43 +00002358 struct ssh *ssh = active_state; /* XXX */
Ben Lindstromabcb1452002-03-22 01:10:21 +00002359 int rsafail = 0;
2360
Damien Millerf0b15df2006-03-26 13:59:20 +11002361 if (BN_cmp(sensitive_data.server_key->rsa->n,
2362 sensitive_data.ssh1_host_key->rsa->n) > 0) {
Ben Lindstromabcb1452002-03-22 01:10:21 +00002363 /* Server key has bigger modulus. */
2364 if (BN_num_bits(sensitive_data.server_key->rsa->n) <
Damien Millerf0b15df2006-03-26 13:59:20 +11002365 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
2366 SSH_KEY_BITS_RESERVED) {
djm@openbsd.org95767262016-03-07 19:02:43 +00002367 fatal("do_connection: %s port %d: "
Damien Millerf0b15df2006-03-26 13:59:20 +11002368 "server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
djm@openbsd.org95767262016-03-07 19:02:43 +00002369 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
Ben Lindstromabcb1452002-03-22 01:10:21 +00002370 BN_num_bits(sensitive_data.server_key->rsa->n),
2371 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
2372 SSH_KEY_BITS_RESERVED);
2373 }
2374 if (rsa_private_decrypt(session_key_int, session_key_int,
Damien Miller86687062014-07-02 15:28:02 +10002375 sensitive_data.server_key->rsa) != 0)
Ben Lindstromabcb1452002-03-22 01:10:21 +00002376 rsafail++;
2377 if (rsa_private_decrypt(session_key_int, session_key_int,
Damien Miller86687062014-07-02 15:28:02 +10002378 sensitive_data.ssh1_host_key->rsa) != 0)
Ben Lindstromabcb1452002-03-22 01:10:21 +00002379 rsafail++;
2380 } else {
2381 /* Host key has bigger modulus (or they are equal). */
2382 if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) <
Damien Millerf0b15df2006-03-26 13:59:20 +11002383 BN_num_bits(sensitive_data.server_key->rsa->n) +
2384 SSH_KEY_BITS_RESERVED) {
djm@openbsd.org95767262016-03-07 19:02:43 +00002385 fatal("do_connection: %s port %d: "
Damien Millerf0b15df2006-03-26 13:59:20 +11002386 "host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d",
djm@openbsd.org95767262016-03-07 19:02:43 +00002387 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
Ben Lindstromabcb1452002-03-22 01:10:21 +00002388 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
2389 BN_num_bits(sensitive_data.server_key->rsa->n),
2390 SSH_KEY_BITS_RESERVED);
2391 }
2392 if (rsa_private_decrypt(session_key_int, session_key_int,
Damien Miller86687062014-07-02 15:28:02 +10002393 sensitive_data.ssh1_host_key->rsa) != 0)
Ben Lindstromabcb1452002-03-22 01:10:21 +00002394 rsafail++;
2395 if (rsa_private_decrypt(session_key_int, session_key_int,
Damien Miller86687062014-07-02 15:28:02 +10002396 sensitive_data.server_key->rsa) != 0)
Ben Lindstromabcb1452002-03-22 01:10:21 +00002397 rsafail++;
2398 }
2399 return (rsafail);
2400}
Damien Miller1f0311c2014-05-15 14:24:09 +10002401
Ben Lindstromabcb1452002-03-22 01:10:21 +00002402/*
Damien Miller396691a2000-01-20 22:44:08 +11002403 * SSH1 key exchange
Damien Miller95def091999-11-25 00:26:21 +11002404 */
Ben Lindstrombba81212001-06-25 05:01:22 +00002405static void
Ben Lindstrom46c16222000-12-22 01:43:59 +00002406do_ssh1_kex(void)
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002407{
djm@openbsd.org95767262016-03-07 19:02:43 +00002408 struct ssh *ssh = active_state; /* XXX */
Damien Miller95def091999-11-25 00:26:21 +11002409 int i, len;
Damien Miller7650bc62001-01-30 09:27:26 +11002410 int rsafail = 0;
tedu@openbsd.orgfebbe092015-01-07 18:15:07 +00002411 BIGNUM *session_key_int, *fake_key_int, *real_key_int;
Ben Lindstrom46c16222000-12-22 01:43:59 +00002412 u_char session_key[SSH_SESSION_KEY_LENGTH];
tedu@openbsd.orgfebbe092015-01-07 18:15:07 +00002413 u_char fake_key_bytes[4096 / 8];
2414 size_t fake_key_len;
Ben Lindstrom46c16222000-12-22 01:43:59 +00002415 u_char cookie[8];
2416 u_int cipher_type, auth_mask, protocol_flags;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002417
Damien Miller5428f641999-11-25 11:54:57 +11002418 /*
2419 * Generate check bytes that the client must send back in the user
2420 * packet in order for it to be accepted; this is used to defy ip
2421 * spoofing attacks. Note that this only works against somebody
2422 * doing IP spoofing from a remote machine; any machine on the local
2423 * network can still see outgoing packets and catch the random
2424 * cookie. This only affects rhosts authentication, and this is one
2425 * of the reasons why it is inherently insecure.
2426 */
Damien Miller354c48c2008-05-19 14:50:00 +10002427 arc4random_buf(cookie, sizeof(cookie));
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002428
Damien Miller5428f641999-11-25 11:54:57 +11002429 /*
2430 * Send our public key. We include in the packet 64 bits of random
2431 * data that must be matched in the reply in order to prevent IP
2432 * spoofing.
2433 */
Damien Miller95def091999-11-25 00:26:21 +11002434 packet_start(SSH_SMSG_PUBLIC_KEY);
2435 for (i = 0; i < 8; i++)
Damien Miller396691a2000-01-20 22:44:08 +11002436 packet_put_char(cookie[i]);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002437
Damien Miller95def091999-11-25 00:26:21 +11002438 /* Store our public server RSA key. */
Damien Miller0bc1bd82000-11-13 22:57:25 +11002439 packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n));
2440 packet_put_bignum(sensitive_data.server_key->rsa->e);
2441 packet_put_bignum(sensitive_data.server_key->rsa->n);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002442
Damien Miller95def091999-11-25 00:26:21 +11002443 /* Store our public host RSA key. */
Damien Miller0bc1bd82000-11-13 22:57:25 +11002444 packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
2445 packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e);
2446 packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002447
Damien Miller95def091999-11-25 00:26:21 +11002448 /* Put protocol flags. */
2449 packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002450
Damien Miller95def091999-11-25 00:26:21 +11002451 /* Declare which ciphers we support. */
Damien Miller874d77b2000-10-14 16:23:11 +11002452 packet_put_int(cipher_mask_ssh1(0));
Damien Miller95def091999-11-25 00:26:21 +11002453
2454 /* Declare supported authentication types. */
2455 auth_mask = 0;
Damien Miller95def091999-11-25 00:26:21 +11002456 if (options.rhosts_rsa_authentication)
2457 auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA;
2458 if (options.rsa_authentication)
2459 auth_mask |= 1 << SSH_AUTH_RSA;
Ben Lindstrom551ea372001-06-05 18:56:16 +00002460 if (options.challenge_response_authentication == 1)
Damien Miller95def091999-11-25 00:26:21 +11002461 auth_mask |= 1 << SSH_AUTH_TIS;
Damien Miller95def091999-11-25 00:26:21 +11002462 if (options.password_authentication)
2463 auth_mask |= 1 << SSH_AUTH_PASSWORD;
2464 packet_put_int(auth_mask);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002465
Damien Miller95def091999-11-25 00:26:21 +11002466 /* Send the packet and wait for it to be sent. */
2467 packet_send();
2468 packet_write_wait();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002469
Damien Miller0bc1bd82000-11-13 22:57:25 +11002470 debug("Sent %d bit server key and %d bit host key.",
2471 BN_num_bits(sensitive_data.server_key->rsa->n),
2472 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002473
Damien Miller95def091999-11-25 00:26:21 +11002474 /* Read clients reply (cipher type and session key). */
Damien Millerdff50992002-01-22 23:16:32 +11002475 packet_read_expect(SSH_CMSG_SESSION_KEY);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002476
Damien Miller50945fa1999-12-09 10:31:37 +11002477 /* Get cipher type and check whether we accept this. */
Damien Miller95def091999-11-25 00:26:21 +11002478 cipher_type = packet_get_char();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002479
Damien Miller874d77b2000-10-14 16:23:11 +11002480 if (!(cipher_mask_ssh1(0) & (1 << cipher_type)))
Damien Miller50945fa1999-12-09 10:31:37 +11002481 packet_disconnect("Warning: client selects unsupported cipher.");
2482
Damien Miller95def091999-11-25 00:26:21 +11002483 /* Get check bytes from the packet. These must match those we
2484 sent earlier with the public key packet. */
2485 for (i = 0; i < 8; i++)
Damien Miller396691a2000-01-20 22:44:08 +11002486 if (cookie[i] != packet_get_char())
Damien Miller95def091999-11-25 00:26:21 +11002487 packet_disconnect("IP Spoofing check bytes do not match.");
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002488
Damien Miller95def091999-11-25 00:26:21 +11002489 debug("Encryption type: %.200s", cipher_name(cipher_type));
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002490
Damien Miller95def091999-11-25 00:26:21 +11002491 /* Get the encrypted integer. */
tedu@openbsd.orgfebbe092015-01-07 18:15:07 +00002492 if ((real_key_int = BN_new()) == NULL)
Damien Millerda755162002-01-22 23:09:22 +11002493 fatal("do_ssh1_kex: BN_new failed");
tedu@openbsd.orgfebbe092015-01-07 18:15:07 +00002494 packet_get_bignum(real_key_int);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002495
Damien Miller95def091999-11-25 00:26:21 +11002496 protocol_flags = packet_get_int();
2497 packet_set_protocol_flags(protocol_flags);
Damien Miller48b03fc2002-01-22 23:11:40 +11002498 packet_check_eom();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002499
tedu@openbsd.orgfebbe092015-01-07 18:15:07 +00002500 /* Setup a fake key in case RSA decryption fails */
2501 if ((fake_key_int = BN_new()) == NULL)
2502 fatal("do_ssh1_kex: BN_new failed");
2503 fake_key_len = BN_num_bytes(real_key_int);
2504 if (fake_key_len > sizeof(fake_key_bytes))
2505 fake_key_len = sizeof(fake_key_bytes);
2506 arc4random_buf(fake_key_bytes, fake_key_len);
2507 if (BN_bin2bn(fake_key_bytes, fake_key_len, fake_key_int) == NULL)
2508 fatal("do_ssh1_kex: BN_bin2bn failed");
2509
2510 /* Decrypt real_key_int using host/server keys */
2511 rsafail = PRIVSEP(ssh1_session_key(real_key_int));
2512 /* If decryption failed, use the fake key. Else, the real key. */
2513 if (rsafail)
2514 session_key_int = fake_key_int;
2515 else
2516 session_key_int = real_key_int;
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002517
Damien Miller5428f641999-11-25 11:54:57 +11002518 /*
2519 * Extract session key from the decrypted integer. The key is in the
2520 * least significant 256 bits of the integer; the first byte of the
2521 * key is in the highest bits.
2522 */
tedu@openbsd.orgfebbe092015-01-07 18:15:07 +00002523 (void) BN_mask_bits(session_key_int, sizeof(session_key) * 8);
2524 len = BN_num_bytes(session_key_int);
2525 if (len < 0 || (u_int)len > sizeof(session_key)) {
djm@openbsd.org95767262016-03-07 19:02:43 +00002526 error("%s: bad session key len from %s port %d: "
2527 "session_key_int %d > sizeof(session_key) %lu", __func__,
2528 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh),
2529 len, (u_long)sizeof(session_key));
tedu@openbsd.orgfebbe092015-01-07 18:15:07 +00002530 rsafail++;
2531 } else {
2532 explicit_bzero(session_key, sizeof(session_key));
2533 BN_bn2bin(session_key_int,
2534 session_key + sizeof(session_key) - len);
Ben Lindstromeb648a72001-03-05 06:00:29 +00002535
tedu@openbsd.orgfebbe092015-01-07 18:15:07 +00002536 derive_ssh1_session_id(
2537 sensitive_data.ssh1_host_key->rsa->n,
2538 sensitive_data.server_key->rsa->n,
2539 cookie, session_id);
2540 /*
2541 * Xor the first 16 bytes of the session key with the
2542 * session id.
2543 */
Ben Lindstrom941ac822001-03-05 06:25:23 +00002544 for (i = 0; i < 16; i++)
tedu@openbsd.orgfebbe092015-01-07 18:15:07 +00002545 session_key[i] ^= session_id[i];
Damien Miller7650bc62001-01-30 09:27:26 +11002546 }
tedu@openbsd.orgfebbe092015-01-07 18:15:07 +00002547
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002548 /* Destroy the private and public keys. No longer. */
Damien Miller3a5b0232002-03-13 13:19:42 +11002549 destroy_sensitive_data();
Ben Lindstromeb648a72001-03-05 06:00:29 +00002550
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002551 if (use_privsep)
2552 mm_ssh1_session_id(session_id);
2553
Damien Miller396691a2000-01-20 22:44:08 +11002554 /* Destroy the decrypted integer. It is no longer needed. */
tedu@openbsd.orgfebbe092015-01-07 18:15:07 +00002555 BN_clear_free(real_key_int);
2556 BN_clear_free(fake_key_int);
Damien Miller396691a2000-01-20 22:44:08 +11002557
Damien Miller95def091999-11-25 00:26:21 +11002558 /* Set the session key. From this on all communications will be encrypted. */
2559 packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002560
Damien Miller95def091999-11-25 00:26:21 +11002561 /* Destroy our copy of the session key. It is no longer needed. */
Damien Millera5103f42014-02-04 11:20:14 +11002562 explicit_bzero(session_key, sizeof(session_key));
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002563
Damien Miller95def091999-11-25 00:26:21 +11002564 debug("Received session key; encryption turned on.");
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002565
Ben Lindstromf666fec2002-06-06 19:51:58 +00002566 /* Send an acknowledgment packet. Note that this packet is sent encrypted. */
Damien Miller95def091999-11-25 00:26:21 +11002567 packet_start(SSH_SMSG_SUCCESS);
2568 packet_send();
2569 packet_write_wait();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002570}
Damien Miller1f0311c2014-05-15 14:24:09 +10002571#endif
Damien Millerefb4afe2000-04-12 18:45:05 +10002572
markus@openbsd.org57d10cb2015-01-19 20:16:15 +00002573int
2574sshd_hostkey_sign(Key *privkey, Key *pubkey, u_char **signature, size_t *slen,
markus@openbsd.org76c9fbb2015-12-04 16:41:28 +00002575 const u_char *data, size_t dlen, const char *alg, u_int flag)
Damien Miller85b45e02013-07-20 13:21:52 +10002576{
djm@openbsd.org141efe42015-01-14 20:05:27 +00002577 int r;
markus@openbsd.org57d10cb2015-01-19 20:16:15 +00002578 u_int xxx_slen, xxx_dlen = dlen;
djm@openbsd.org141efe42015-01-14 20:05:27 +00002579
Damien Miller85b45e02013-07-20 13:21:52 +10002580 if (privkey) {
markus@openbsd.org76c9fbb2015-12-04 16:41:28 +00002581 if (PRIVSEP(key_sign(privkey, signature, &xxx_slen, data, xxx_dlen,
2582 alg) < 0))
Damien Miller85b45e02013-07-20 13:21:52 +10002583 fatal("%s: key_sign failed", __func__);
markus@openbsd.org57d10cb2015-01-19 20:16:15 +00002584 if (slen)
2585 *slen = xxx_slen;
Damien Miller85b45e02013-07-20 13:21:52 +10002586 } else if (use_privsep) {
markus@openbsd.org76c9fbb2015-12-04 16:41:28 +00002587 if (mm_key_sign(pubkey, signature, &xxx_slen, data, xxx_dlen,
2588 alg) < 0)
Damien Miller85b45e02013-07-20 13:21:52 +10002589 fatal("%s: pubkey_sign failed", __func__);
markus@openbsd.org57d10cb2015-01-19 20:16:15 +00002590 if (slen)
2591 *slen = xxx_slen;
Damien Miller85b45e02013-07-20 13:21:52 +10002592 } else {
markus@openbsd.org57d10cb2015-01-19 20:16:15 +00002593 if ((r = ssh_agent_sign(auth_sock, pubkey, signature, slen,
markus@openbsd.org76c9fbb2015-12-04 16:41:28 +00002594 data, dlen, alg, datafellows)) != 0)
djm@openbsd.org141efe42015-01-14 20:05:27 +00002595 fatal("%s: ssh_agent_sign failed: %s",
2596 __func__, ssh_err(r));
Damien Miller85b45e02013-07-20 13:21:52 +10002597 }
markus@openbsd.org57d10cb2015-01-19 20:16:15 +00002598 return 0;
Damien Miller85b45e02013-07-20 13:21:52 +10002599}
2600
djm@openbsd.orgbdfd29f2015-07-03 03:47:00 +00002601/* SSH2 key exchange */
Ben Lindstrombba81212001-06-25 05:01:22 +00002602static void
Ben Lindstrom46c16222000-12-22 01:43:59 +00002603do_ssh2_kex(void)
Damien Millerefb4afe2000-04-12 18:45:05 +10002604{
Damien Miller9235a032014-04-20 13:17:20 +10002605 char *myproposal[PROPOSAL_MAX] = { KEX_SERVER };
markus@openbsd.org57d10cb2015-01-19 20:16:15 +00002606 struct kex *kex;
markus@openbsd.org57e783c2015-01-20 20:16:21 +00002607 int r;
Damien Millerefb4afe2000-04-12 18:45:05 +10002608
djm@openbsd.orgf9eca242015-07-30 00:01:34 +00002609 myproposal[PROPOSAL_KEX_ALGS] = compat_kex_proposal(
2610 options.kex_algorithms);
2611 myproposal[PROPOSAL_ENC_ALGS_CTOS] = compat_cipher_proposal(
2612 options.ciphers);
2613 myproposal[PROPOSAL_ENC_ALGS_STOC] = compat_cipher_proposal(
2614 options.ciphers);
2615 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
2616 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
Damien Millera0ff4662001-03-30 10:49:35 +10002617
Damien Miller9786e6e2005-07-26 21:54:56 +10002618 if (options.compression == COMP_NONE) {
Ben Lindstrom23e0f662002-06-21 01:09:47 +00002619 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
dtucker@openbsd.org8c02e362016-05-24 04:43:45 +00002620 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
Damien Miller9786e6e2005-07-26 21:54:56 +10002621 } else if (options.compression == COMP_DELAYED) {
2622 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
dtucker@openbsd.org8c02e362016-05-24 04:43:45 +00002623 myproposal[PROPOSAL_COMP_ALGS_STOC] =
2624 "none,zlib@openssh.com";
Ben Lindstrom23e0f662002-06-21 01:09:47 +00002625 }
Damien Miller9395b282014-04-20 13:25:30 +10002626
Darren Tucker5f96f3b2013-05-16 20:29:28 +10002627 if (options.rekey_limit || options.rekey_interval)
dtucker@openbsd.org921ff002016-01-29 02:54:45 +00002628 packet_set_rekey_limits(options.rekey_limit,
Darren Tucker5f96f3b2013-05-16 20:29:28 +10002629 (time_t)options.rekey_interval);
2630
Damien Miller324541e2013-12-31 12:25:40 +11002631 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = compat_pkalg_proposal(
2632 list_hostkey_types());
Damien Miller0bc1bd82000-11-13 22:57:25 +11002633
Ben Lindstrom8ac91062001-04-04 17:57:54 +00002634 /* start key exchange */
markus@openbsd.org57e783c2015-01-20 20:16:21 +00002635 if ((r = kex_setup(active_state, myproposal)) != 0)
2636 fatal("kex_setup: %s", ssh_err(r));
markus@openbsd.org57d10cb2015-01-19 20:16:15 +00002637 kex = active_state->kex;
Damien Miller1f0311c2014-05-15 14:24:09 +10002638#ifdef WITH_OPENSSL
Damien Miller8e7fb332003-02-24 12:03:03 +11002639 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
Damien Millerf675fc42004-06-15 10:30:09 +10002640 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
djm@openbsd.org0e8eeec2016-05-02 10:26:04 +00002641 kex->kex[KEX_DH_GRP14_SHA256] = kexdh_server;
2642 kex->kex[KEX_DH_GRP16_SHA512] = kexdh_server;
2643 kex->kex[KEX_DH_GRP18_SHA512] = kexdh_server;
Damien Miller8e7fb332003-02-24 12:03:03 +11002644 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
Damien Millera63128d2006-03-15 12:08:28 +11002645 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
Darren Tuckerf2004cd2015-02-23 05:04:21 +11002646# ifdef OPENSSL_HAS_ECC
Damien Millereb8b60e2010-08-31 22:41:14 +10002647 kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
Darren Tuckerf2004cd2015-02-23 05:04:21 +11002648# endif
Damien Miller1f0311c2014-05-15 14:24:09 +10002649#endif
Damien Miller1e124262013-11-04 08:26:52 +11002650 kex->kex[KEX_C25519_SHA256] = kexc25519_server;
Ben Lindstrom20d7c7b2001-04-04 01:56:17 +00002651 kex->server = 1;
2652 kex->client_version_string=client_version_string;
2653 kex->server_version_string=server_version_string;
Damien Miller0a80ca12010-02-27 07:55:05 +11002654 kex->load_host_public_key=&get_hostkey_public_by_type;
2655 kex->load_host_private_key=&get_hostkey_private_by_type;
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002656 kex->host_key_index=&get_hostkey_index;
Damien Miller85b45e02013-07-20 13:21:52 +10002657 kex->sign = sshd_hostkey_sign;
Damien Millerefb4afe2000-04-12 18:45:05 +10002658
markus@openbsd.org57d10cb2015-01-19 20:16:15 +00002659 dispatch_run(DISPATCH_BLOCK, &kex->done, active_state);
Damien Miller874d77b2000-10-14 16:23:11 +11002660
Ben Lindstrom2d90e002001-04-04 02:00:54 +00002661 session_id2 = kex->session_id;
2662 session_id2_len = kex->session_id_len;
2663
Damien Miller874d77b2000-10-14 16:23:11 +11002664#ifdef DEBUG_KEXDH
2665 /* send 1st encrypted/maced/compressed message */
2666 packet_start(SSH2_MSG_IGNORE);
2667 packet_put_cstring("markus");
2668 packet_send();
2669 packet_write_wait();
2670#endif
Ben Lindstrom20d7c7b2001-04-04 01:56:17 +00002671 debug("KEX done");
Damien Millerefb4afe2000-04-12 18:45:05 +10002672}
Darren Tucker3e33cec2003-10-02 16:12:36 +10002673
2674/* server specific fatal cleanup */
2675void
2676cleanup_exit(int i)
2677{
Damien Miller9ee2c602011-09-22 21:38:30 +10002678 if (the_authctxt) {
Darren Tucker3e33cec2003-10-02 16:12:36 +10002679 do_cleanup(the_authctxt);
Damien Miller75c62722014-04-20 13:24:31 +10002680 if (use_privsep && privsep_is_preauth &&
2681 pmonitor != NULL && pmonitor->m_pid > 1) {
Damien Miller9ee2c602011-09-22 21:38:30 +10002682 debug("Killing privsep child %d", pmonitor->m_pid);
2683 if (kill(pmonitor->m_pid, SIGKILL) != 0 &&
Darren Tucker2e135602011-10-02 19:10:13 +11002684 errno != ESRCH)
Damien Miller9ee2c602011-09-22 21:38:30 +10002685 error("%s: kill(%d): %s", __func__,
2686 pmonitor->m_pid, strerror(errno));
2687 }
2688 }
Darren Tucker2e0cf0d2005-02-08 21:52:47 +11002689#ifdef SSH_AUDIT_EVENTS
Darren Tucker269a1ea2005-02-03 00:20:53 +11002690 /* done after do_cleanup so it can cancel the PAM auth 'thread' */
2691 if (!use_privsep || mm_is_monitor())
Darren Tucker2e0cf0d2005-02-08 21:52:47 +11002692 audit_event(SSH_CONNECTION_ABANDON);
Darren Tucker269a1ea2005-02-03 00:20:53 +11002693#endif
Darren Tucker3e33cec2003-10-02 16:12:36 +10002694 _exit(i);
2695}