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Darren Tuckera627d422013-06-02 07:31:17 +10001/* $OpenBSD: sshd.c,v 1.402 2013/05/17 00:13:14 djm 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>
Damien Millerd4a8b7e1999-10-27 13:42:43 +100074
Ben Lindstrom226cfa02001-01-22 05:34:40 +000075#include <openssl/dh.h>
76#include <openssl/bn.h>
Damien Miller6a47f302002-02-13 13:55:06 +110077#include <openssl/md5.h>
Ben Lindstrom7a2073c2002-03-22 02:30:41 +000078#include <openssl/rand.h>
Darren Tuckerbfaaf962008-02-28 19:13:52 +110079#include "openbsd-compat/openssl-compat.h"
80
Kevin Steves0ea1d9d2002-04-25 18:17:04 +000081#ifdef HAVE_SECUREWARE
82#include <sys/security.h>
83#include <prot.h>
84#endif
Ben Lindstrom226cfa02001-01-22 05:34:40 +000085
Damien Millerd7834352006-08-05 12:39:39 +100086#include "xmalloc.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000087#include "ssh.h"
88#include "ssh1.h"
89#include "ssh2.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100090#include "rsa.h"
Ben Lindstromd95c09c2001-02-18 19:13:33 +000091#include "sshpty.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100092#include "packet.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000093#include "log.h"
Damien Millerd7834352006-08-05 12:39:39 +100094#include "buffer.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100095#include "servconf.h"
96#include "uidswap.h"
97#include "compat.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000098#include "cipher.h"
Damien Millerb38eff82000-04-01 11:09:21 +100099#include "key.h"
Damien Millerd7834352006-08-05 12:39:39 +1000100#include "kex.h"
Damien Miller874d77b2000-10-14 16:23:11 +1100101#include "dh.h"
Damien Millerefb4afe2000-04-12 18:45:05 +1000102#include "myproposal.h"
Damien Millereba71ba2000-04-29 23:57:08 +1000103#include "authfile.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +0000104#include "pathnames.h"
105#include "atomicio.h"
106#include "canohost.h"
Damien Millerd7834352006-08-05 12:39:39 +1000107#include "hostfile.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +0000108#include "auth.h"
109#include "misc.h"
Darren Tucker645ab752004-06-25 13:33:20 +1000110#include "msg.h"
Ben Lindstrom20d7c7b2001-04-04 01:56:17 +0000111#include "dispatch.h"
Ben Lindstrom1bae4042001-10-03 17:46:39 +0000112#include "channels.h"
Ben Lindstrom73ab9ba2002-03-22 01:27:35 +0000113#include "session.h"
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000114#include "monitor_mm.h"
115#include "monitor.h"
Damien Millerd7834352006-08-05 12:39:39 +1000116#ifdef GSSAPI
117#include "ssh-gss.h"
118#endif
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000119#include "monitor_wrap.h"
Darren Tuckerc5564e12009-06-21 18:53:53 +1000120#include "roaming.h"
Damien Millerdcbd41e2011-06-23 19:45:51 +1000121#include "ssh-sandbox.h"
Damien Millerb7576772006-07-10 20:23:39 +1000122#include "version.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000123
124#ifdef LIBWRAP
125#include <tcpd.h>
126#include <syslog.h>
Darren Tucker1f1e17b2008-02-28 23:20:48 +1100127int allow_severity;
128int deny_severity;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000129#endif /* LIBWRAP */
130
131#ifndef O_NOCTTY
132#define O_NOCTTY 0
133#endif
134
Damien Miller035a5b42004-06-26 08:16:31 +1000135/* Re-exec fds */
136#define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1)
137#define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2)
138#define REEXEC_CONFIG_PASS_FD (STDERR_FILENO + 3)
139#define REEXEC_MIN_FREE_FD (STDERR_FILENO + 4)
140
Ben Lindstrom49a79c02000-11-17 03:47:20 +0000141extern char *__progname;
Ben Lindstrom49a79c02000-11-17 03:47:20 +0000142
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000143/* Server configuration options. */
144ServerOptions options;
145
146/* Name of the server configuration file. */
Ben Lindstrom226cfa02001-01-22 05:34:40 +0000147char *config_file_name = _PATH_SERVER_CONFIG_FILE;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000148
Damien Miller4af51302000-04-16 11:18:38 +1000149/*
Damien Miller95def091999-11-25 00:26:21 +1100150 * Debug mode flag. This can be set on the command line. If debug
151 * mode is enabled, extra debugging output will be sent to the system
152 * log, the daemon will not go to background, and will exit after processing
153 * the first connection.
154 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000155int debug_flag = 0;
156
Ben Lindstrom794325a2001-08-06 21:09:07 +0000157/* Flag indicating that the daemon should only test the configuration and keys. */
158int test_flag = 0;
159
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000160/* Flag indicating that the daemon is being started from inetd. */
161int inetd_flag = 0;
162
Ben Lindstromc72745a2000-12-02 19:03:54 +0000163/* Flag indicating that sshd should not detach and become a daemon. */
164int no_daemon_flag = 0;
165
Damien Miller5ce662a1999-11-11 17:57:39 +1100166/* debug goes to stderr unless inetd_flag is set */
167int log_stderr = 0;
168
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000169/* Saved arguments to main(). */
170char **saved_argv;
Damien Millerb8c656e2000-06-28 15:22:41 +1000171int saved_argc;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000172
Darren Tucker645ab752004-06-25 13:33:20 +1000173/* re-exec */
174int rexeced_flag = 0;
175int rexec_flag = 1;
176int rexec_argc = 0;
177char **rexec_argv;
178
Damien Miller5428f641999-11-25 11:54:57 +1100179/*
Damien Miller34132e52000-01-14 15:45:46 +1100180 * The sockets that the server is listening; this is used in the SIGHUP
181 * signal handler.
Damien Miller5428f641999-11-25 11:54:57 +1100182 */
Damien Miller34132e52000-01-14 15:45:46 +1100183#define MAX_LISTEN_SOCKS 16
184int listen_socks[MAX_LISTEN_SOCKS];
185int num_listen_socks = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000186
Damien Miller5428f641999-11-25 11:54:57 +1100187/*
188 * the client's version string, passed by sshd2 in compat mode. if != NULL,
189 * sshd will skip the version-number exchange
190 */
Damien Miller95def091999-11-25 00:26:21 +1100191char *client_version_string = NULL;
Damien Millerb38eff82000-04-01 11:09:21 +1000192char *server_version_string = NULL;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000193
Ben Lindstrom8ac91062001-04-04 17:57:54 +0000194/* for rekeying XXX fixme */
195Kex *xxx_kex;
196
Damien Miller5428f641999-11-25 11:54:57 +1100197/*
198 * Any really sensitive data in the application is contained in this
199 * structure. The idea is that this structure could be locked into memory so
200 * that the pages do not get written into swap. However, there are some
201 * problems. The private key contains BIGNUMs, and we do not (in principle)
202 * have access to the internals of them, and locking just the structure is
203 * not very useful. Currently, memory locking is not implemented.
204 */
Damien Miller95def091999-11-25 00:26:21 +1100205struct {
Ben Lindstromca42d5f2001-03-09 18:25:32 +0000206 Key *server_key; /* ephemeral server key */
Damien Miller0bc1bd82000-11-13 22:57:25 +1100207 Key *ssh1_host_key; /* ssh1 host key */
208 Key **host_keys; /* all private host keys */
Damien Miller0a80ca12010-02-27 07:55:05 +1100209 Key **host_certificates; /* all public host certificates */
Damien Miller0bc1bd82000-11-13 22:57:25 +1100210 int have_ssh1_key;
211 int have_ssh2_key;
Ben Lindstromeb648a72001-03-05 06:00:29 +0000212 u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH];
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000213} sensitive_data;
214
Damien Miller5428f641999-11-25 11:54:57 +1100215/*
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000216 * Flag indicating whether the RSA server key needs to be regenerated.
217 * Is set in the SIGALRM handler and cleared when the key is regenerated.
Damien Miller5428f641999-11-25 11:54:57 +1100218 */
Ben Lindstrom5e71c542001-12-06 16:48:14 +0000219static volatile sig_atomic_t key_do_regen = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000220
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000221/* This is set to true when a signal is received. */
Ben Lindstrom5e71c542001-12-06 16:48:14 +0000222static volatile sig_atomic_t received_sighup = 0;
223static volatile sig_atomic_t received_sigterm = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000224
Damien Millerb38eff82000-04-01 11:09:21 +1000225/* session identifier, used by RSA-auth */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000226u_char session_id[16];
Damien Millerb38eff82000-04-01 11:09:21 +1000227
Damien Millereba71ba2000-04-29 23:57:08 +1000228/* same for ssh2 */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000229u_char *session_id2 = NULL;
Darren Tucker502d3842003-06-28 12:38:01 +1000230u_int session_id2_len = 0;
Damien Millereba71ba2000-04-29 23:57:08 +1000231
Damien Miller942da032000-08-18 13:59:06 +1000232/* record remote hostname or ip */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000233u_int utmp_len = MAXHOSTNAMELEN;
Damien Miller942da032000-08-18 13:59:06 +1000234
Ben Lindstromd84df982001-12-06 16:35:40 +0000235/* options.max_startup sized array of fd ints */
236int *startup_pipes = NULL;
237int startup_pipe; /* in child */
238
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000239/* variables used for privilege separation */
Darren Tucker45150472006-07-12 22:34:17 +1000240int use_privsep = -1;
Darren Tuckera8be9e22004-02-06 16:40:27 +1100241struct monitor *pmonitor = NULL;
Damien Miller9ee2c602011-09-22 21:38:30 +1000242int privsep_is_preauth = 1;
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000243
Darren Tucker3e33cec2003-10-02 16:12:36 +1000244/* global authentication context */
245Authctxt *the_authctxt = NULL;
246
Darren Tucker45150472006-07-12 22:34:17 +1000247/* sshd_config buffer */
248Buffer cfg;
249
Darren Tucker09991742004-07-17 17:05:14 +1000250/* message to be displayed after login */
251Buffer loginmsg;
252
Damien Miller6433df02006-09-07 10:36:43 +1000253/* Unprivileged user */
254struct passwd *privsep_pw = NULL;
255
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000256/* Prototypes for various functions defined later in this file. */
Ben Lindstrombba81212001-06-25 05:01:22 +0000257void destroy_sensitive_data(void);
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000258void demote_sensitive_data(void);
Damien Miller98c7ad62000-03-09 21:27:49 +1100259
Ben Lindstrombba81212001-06-25 05:01:22 +0000260static void do_ssh1_kex(void);
261static void do_ssh2_kex(void);
Damien Miller874d77b2000-10-14 16:23:11 +1100262
Damien Miller98c7ad62000-03-09 21:27:49 +1100263/*
Damien Miller34132e52000-01-14 15:45:46 +1100264 * Close all listening sockets
265 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000266static void
Damien Miller34132e52000-01-14 15:45:46 +1100267close_listen_socks(void)
268{
269 int i;
Ben Lindstrom822b6342002-06-23 21:38:49 +0000270
Damien Miller34132e52000-01-14 15:45:46 +1100271 for (i = 0; i < num_listen_socks; i++)
272 close(listen_socks[i]);
273 num_listen_socks = -1;
274}
275
Ben Lindstromd84df982001-12-06 16:35:40 +0000276static void
277close_startup_pipes(void)
278{
279 int i;
Ben Lindstrom822b6342002-06-23 21:38:49 +0000280
Ben Lindstromd84df982001-12-06 16:35:40 +0000281 if (startup_pipes)
282 for (i = 0; i < options.max_startups; i++)
283 if (startup_pipes[i] != -1)
284 close(startup_pipes[i]);
285}
286
Damien Miller34132e52000-01-14 15:45:46 +1100287/*
Damien Miller95def091999-11-25 00:26:21 +1100288 * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP;
289 * the effect is to reread the configuration file (and to regenerate
290 * the server key).
291 */
Damien Millerf0b15df2006-03-26 13:59:20 +1100292
293/*ARGSUSED*/
Ben Lindstrombba81212001-06-25 05:01:22 +0000294static void
Damien Miller95def091999-11-25 00:26:21 +1100295sighup_handler(int sig)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000296{
Ben Lindstrom07958482001-12-06 16:19:01 +0000297 int save_errno = errno;
298
Damien Miller95def091999-11-25 00:26:21 +1100299 received_sighup = 1;
300 signal(SIGHUP, sighup_handler);
Ben Lindstrom07958482001-12-06 16:19:01 +0000301 errno = save_errno;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000302}
303
Damien Miller95def091999-11-25 00:26:21 +1100304/*
305 * Called from the main program after receiving SIGHUP.
306 * Restarts the server.
307 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000308static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000309sighup_restart(void)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000310{
Damien Miller996acd22003-04-09 20:59:48 +1000311 logit("Received SIGHUP; restarting.");
Damien Miller34132e52000-01-14 15:45:46 +1100312 close_listen_socks();
Ben Lindstromd84df982001-12-06 16:35:40 +0000313 close_startup_pipes();
Darren Tuckered623962007-02-25 20:37:21 +1100314 alarm(0); /* alarm timer persists across exec */
Darren Tucker2c671bf2010-01-09 22:28:43 +1100315 signal(SIGHUP, SIG_IGN); /* will be restored after exec */
Damien Miller95def091999-11-25 00:26:21 +1100316 execv(saved_argv[0], saved_argv);
Damien Miller996acd22003-04-09 20:59:48 +1000317 logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0],
Ben Lindstrom822b6342002-06-23 21:38:49 +0000318 strerror(errno));
Damien Miller95def091999-11-25 00:26:21 +1100319 exit(1);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000320}
321
Damien Miller95def091999-11-25 00:26:21 +1100322/*
323 * Generic signal handler for terminating signals in the master daemon.
Damien Miller95def091999-11-25 00:26:21 +1100324 */
Damien Millerf0b15df2006-03-26 13:59:20 +1100325/*ARGSUSED*/
Ben Lindstrombba81212001-06-25 05:01:22 +0000326static void
Damien Miller95def091999-11-25 00:26:21 +1100327sigterm_handler(int sig)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000328{
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000329 received_sigterm = sig;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000330}
331
Damien Miller95def091999-11-25 00:26:21 +1100332/*
333 * SIGCHLD handler. This is called whenever a child dies. This will then
Ben Lindstromec46e0b2001-06-09 01:27:31 +0000334 * reap any zombies left by exited children.
Damien Miller95def091999-11-25 00:26:21 +1100335 */
Damien Millerf0b15df2006-03-26 13:59:20 +1100336/*ARGSUSED*/
Ben Lindstrombba81212001-06-25 05:01:22 +0000337static void
Damien Miller95def091999-11-25 00:26:21 +1100338main_sigchld_handler(int sig)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000339{
Damien Miller95def091999-11-25 00:26:21 +1100340 int save_errno = errno;
Ben Lindstrom822b6342002-06-23 21:38:49 +0000341 pid_t pid;
Damien Miller95def091999-11-25 00:26:21 +1100342 int status;
Damien Miller431f66b1999-11-21 18:31:57 +1100343
Ben Lindstrom47fd8112002-04-02 20:48:19 +0000344 while ((pid = waitpid(-1, &status, WNOHANG)) > 0 ||
345 (pid < 0 && errno == EINTR))
Damien Miller95def091999-11-25 00:26:21 +1100346 ;
Damien Miller431f66b1999-11-21 18:31:57 +1100347
Damien Miller95def091999-11-25 00:26:21 +1100348 signal(SIGCHLD, main_sigchld_handler);
349 errno = save_errno;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000350}
351
Damien Miller95def091999-11-25 00:26:21 +1100352/*
353 * Signal handler for the alarm after the login grace period has expired.
354 */
Damien Millerf0b15df2006-03-26 13:59:20 +1100355/*ARGSUSED*/
Ben Lindstrombba81212001-06-25 05:01:22 +0000356static void
Damien Miller95def091999-11-25 00:26:21 +1100357grace_alarm_handler(int sig)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000358{
Darren Tuckera8be9e22004-02-06 16:40:27 +1100359 if (use_privsep && pmonitor != NULL && pmonitor->m_pid > 0)
360 kill(pmonitor->m_pid, SIGALRM);
361
Damien Miller09d3e122012-10-31 08:58:58 +1100362 /*
363 * Try to kill any processes that we have spawned, E.g. authorized
364 * keys command helpers.
365 */
366 if (getpgid(0) == getpid()) {
367 signal(SIGTERM, SIG_IGN);
368 killpg(0, SIGTERM);
369 }
370
Damien Miller95def091999-11-25 00:26:21 +1100371 /* Log error and exit. */
Damien Miller99a648e2006-08-19 00:32:20 +1000372 sigdie("Timeout before authentication for %s", get_remote_ipaddr());
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000373}
374
Damien Miller95def091999-11-25 00:26:21 +1100375/*
Damien Miller95def091999-11-25 00:26:21 +1100376 * Signal handler for the key regeneration alarm. Note that this
377 * alarm only occurs in the daemon waiting for connections, and it does not
378 * do anything with the private key or random state before forking.
379 * Thus there should be no concurrency control/asynchronous execution
380 * problems.
381 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000382static void
Ben Lindstromca42d5f2001-03-09 18:25:32 +0000383generate_ephemeral_server_key(void)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100384{
Ben Lindstroma3700052001-04-05 23:26:32 +0000385 verbose("Generating %s%d bit RSA key.",
Damien Millerff75ac42001-03-30 10:50:32 +1000386 sensitive_data.server_key ? "new " : "", options.server_key_bits);
Damien Miller0bc1bd82000-11-13 22:57:25 +1100387 if (sensitive_data.server_key != NULL)
388 key_free(sensitive_data.server_key);
Ben Lindstroma3700052001-04-05 23:26:32 +0000389 sensitive_data.server_key = key_generate(KEY_RSA1,
Damien Millerff75ac42001-03-30 10:50:32 +1000390 options.server_key_bits);
391 verbose("RSA key generation complete.");
Ben Lindstromeb648a72001-03-05 06:00:29 +0000392
Damien Miller354c48c2008-05-19 14:50:00 +1000393 arc4random_buf(sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
Ben Lindstromeb648a72001-03-05 06:00:29 +0000394 arc4random_stir();
Damien Miller0bc1bd82000-11-13 22:57:25 +1100395}
Ben Lindstrom2f959b42001-01-11 06:20:23 +0000396
Damien Millerf0b15df2006-03-26 13:59:20 +1100397/*ARGSUSED*/
Ben Lindstrombba81212001-06-25 05:01:22 +0000398static void
Damien Miller95def091999-11-25 00:26:21 +1100399key_regeneration_alarm(int sig)
400{
401 int save_errno = errno;
Ben Lindstrom822b6342002-06-23 21:38:49 +0000402
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000403 signal(SIGALRM, SIG_DFL);
Damien Miller95def091999-11-25 00:26:21 +1100404 errno = save_errno;
Ben Lindstromdb65e8f2001-01-19 04:26:52 +0000405 key_do_regen = 1;
Damien Miller95def091999-11-25 00:26:21 +1100406}
407
Ben Lindstrombba81212001-06-25 05:01:22 +0000408static void
Damien Millerb38eff82000-04-01 11:09:21 +1000409sshd_exchange_identification(int sock_in, int sock_out)
410{
Damien Millereccb9de2005-06-17 12:59:34 +1000411 u_int i;
412 int mismatch;
Damien Millerb38eff82000-04-01 11:09:21 +1000413 int remote_major, remote_minor;
Damien Miller78928792000-04-12 20:17:38 +1000414 int major, minor;
Darren Tuckerd7bdc0c2008-07-02 22:34:30 +1000415 char *s, *newline = "\n";
Damien Millerb38eff82000-04-01 11:09:21 +1000416 char buf[256]; /* Must not be larger than remote_version. */
417 char remote_version[256]; /* Must be at least as big as buf. */
418
Damien Miller78928792000-04-12 20:17:38 +1000419 if ((options.protocol & SSH_PROTO_1) &&
420 (options.protocol & SSH_PROTO_2)) {
421 major = PROTOCOL_MAJOR_1;
422 minor = 99;
423 } else if (options.protocol & SSH_PROTO_2) {
424 major = PROTOCOL_MAJOR_2;
425 minor = PROTOCOL_MINOR_2;
Darren Tuckerd7bdc0c2008-07-02 22:34:30 +1000426 newline = "\r\n";
Damien Miller78928792000-04-12 20:17:38 +1000427 } else {
428 major = PROTOCOL_MAJOR_1;
429 minor = PROTOCOL_MINOR_1;
430 }
Damien Miller23528812012-04-22 11:24:43 +1000431
432 xasprintf(&server_version_string, "SSH-%d.%d-%.100s%s%s%s",
433 major, minor, SSH_VERSION,
434 *options.version_addendum == '\0' ? "" : " ",
435 options.version_addendum, newline);
Damien Millerb38eff82000-04-01 11:09:21 +1000436
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000437 /* Send our protocol version identification. */
Darren Tuckerc5564e12009-06-21 18:53:53 +1000438 if (roaming_atomicio(vwrite, sock_out, server_version_string,
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000439 strlen(server_version_string))
440 != strlen(server_version_string)) {
441 logit("Could not write ident string to %s", get_remote_ipaddr());
Darren Tucker3e33cec2003-10-02 16:12:36 +1000442 cleanup_exit(255);
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000443 }
444
445 /* Read other sides version identification. */
446 memset(buf, 0, sizeof(buf));
447 for (i = 0; i < sizeof(buf) - 1; i++) {
Darren Tuckerc5564e12009-06-21 18:53:53 +1000448 if (roaming_atomicio(read, sock_in, &buf[i], 1) != 1) {
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000449 logit("Did not receive identification string from %s",
450 get_remote_ipaddr());
Darren Tucker3e33cec2003-10-02 16:12:36 +1000451 cleanup_exit(255);
Damien Millerb38eff82000-04-01 11:09:21 +1000452 }
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000453 if (buf[i] == '\r') {
454 buf[i] = 0;
455 /* Kludge for F-Secure Macintosh < 1.0.2 */
456 if (i == 12 &&
457 strncmp(buf, "SSH-1.5-W1.0", 12) == 0)
Damien Millerb38eff82000-04-01 11:09:21 +1000458 break;
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000459 continue;
Damien Millerb38eff82000-04-01 11:09:21 +1000460 }
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000461 if (buf[i] == '\n') {
462 buf[i] = 0;
463 break;
464 }
Damien Millerb38eff82000-04-01 11:09:21 +1000465 }
Darren Tuckerfe0078a2003-07-19 19:52:28 +1000466 buf[sizeof(buf) - 1] = 0;
467 client_version_string = xstrdup(buf);
Damien Millerb38eff82000-04-01 11:09:21 +1000468
469 /*
470 * Check that the versions match. In future this might accept
471 * several versions and set appropriate flags to handle them.
472 */
473 if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n",
474 &remote_major, &remote_minor, remote_version) != 3) {
Damien Miller4af51302000-04-16 11:18:38 +1000475 s = "Protocol mismatch.\n";
Darren Tucker9f63f222003-07-03 13:46:56 +1000476 (void) atomicio(vwrite, sock_out, s, strlen(s));
Damien Millerb38eff82000-04-01 11:09:21 +1000477 close(sock_in);
478 close(sock_out);
Damien Miller996acd22003-04-09 20:59:48 +1000479 logit("Bad protocol version identification '%.100s' from %s",
Damien Millerb38eff82000-04-01 11:09:21 +1000480 client_version_string, get_remote_ipaddr());
Darren Tucker3e33cec2003-10-02 16:12:36 +1000481 cleanup_exit(255);
Damien Millerb38eff82000-04-01 11:09:21 +1000482 }
483 debug("Client protocol version %d.%d; client software version %.100s",
Damien Miller9f0f5c62001-12-21 14:45:46 +1100484 remote_major, remote_minor, remote_version);
Damien Millerb38eff82000-04-01 11:09:21 +1000485
Damien Millerefb4afe2000-04-12 18:45:05 +1000486 compat_datafellows(remote_version);
487
Damien Millere9264972002-09-30 11:59:21 +1000488 if (datafellows & SSH_BUG_PROBE) {
Damien Miller996acd22003-04-09 20:59:48 +1000489 logit("probed from %s with %s. Don't panic.",
Damien Millere9264972002-09-30 11:59:21 +1000490 get_remote_ipaddr(), client_version_string);
Darren Tucker3e33cec2003-10-02 16:12:36 +1000491 cleanup_exit(255);
Damien Millere9264972002-09-30 11:59:21 +1000492 }
493
Damien Miller27dbe6f2001-03-19 22:36:20 +1100494 if (datafellows & SSH_BUG_SCANNER) {
Damien Miller996acd22003-04-09 20:59:48 +1000495 logit("scanned from %s with %s. Don't panic.",
Damien Miller27dbe6f2001-03-19 22:36:20 +1100496 get_remote_ipaddr(), client_version_string);
Darren Tucker3e33cec2003-10-02 16:12:36 +1000497 cleanup_exit(255);
Damien Miller27dbe6f2001-03-19 22:36:20 +1100498 }
499
Damien Miller78928792000-04-12 20:17:38 +1000500 mismatch = 0;
Ben Lindstrom1c37c6a2001-12-06 18:00:18 +0000501 switch (remote_major) {
Damien Millerb38eff82000-04-01 11:09:21 +1000502 case 1:
Damien Millereba71ba2000-04-29 23:57:08 +1000503 if (remote_minor == 99) {
504 if (options.protocol & SSH_PROTO_2)
505 enable_compat20();
506 else
507 mismatch = 1;
508 break;
509 }
Damien Miller78928792000-04-12 20:17:38 +1000510 if (!(options.protocol & SSH_PROTO_1)) {
511 mismatch = 1;
512 break;
513 }
Damien Millerb38eff82000-04-01 11:09:21 +1000514 if (remote_minor < 3) {
Damien Miller37023962000-07-11 17:31:38 +1000515 packet_disconnect("Your ssh version is too old and "
Damien Millerb38eff82000-04-01 11:09:21 +1000516 "is no longer supported. Please install a newer version.");
517 } else if (remote_minor == 3) {
518 /* note that this disables agent-forwarding */
519 enable_compat13();
520 }
Damien Miller78928792000-04-12 20:17:38 +1000521 break;
Damien Millerefb4afe2000-04-12 18:45:05 +1000522 case 2:
Damien Miller78928792000-04-12 20:17:38 +1000523 if (options.protocol & SSH_PROTO_2) {
Damien Millerefb4afe2000-04-12 18:45:05 +1000524 enable_compat20();
525 break;
526 }
527 /* FALLTHROUGH */
Damien Miller4af51302000-04-16 11:18:38 +1000528 default:
Damien Miller78928792000-04-12 20:17:38 +1000529 mismatch = 1;
Damien Millerb38eff82000-04-01 11:09:21 +1000530 break;
531 }
Damien Millerefb4afe2000-04-12 18:45:05 +1000532 chop(server_version_string);
Damien Miller78928792000-04-12 20:17:38 +1000533 debug("Local version string %.200s", server_version_string);
534
535 if (mismatch) {
536 s = "Protocol major versions differ.\n";
Darren Tucker9f63f222003-07-03 13:46:56 +1000537 (void) atomicio(vwrite, sock_out, s, strlen(s));
Damien Miller78928792000-04-12 20:17:38 +1000538 close(sock_in);
539 close(sock_out);
Damien Miller996acd22003-04-09 20:59:48 +1000540 logit("Protocol major versions differ for %s: %.200s vs. %.200s",
Damien Miller78928792000-04-12 20:17:38 +1000541 get_remote_ipaddr(),
542 server_version_string, client_version_string);
Darren Tucker3e33cec2003-10-02 16:12:36 +1000543 cleanup_exit(255);
Damien Miller78928792000-04-12 20:17:38 +1000544 }
Damien Millereba71ba2000-04-29 23:57:08 +1000545}
546
Damien Miller0bc1bd82000-11-13 22:57:25 +1100547/* Destroy the host and server keys. They will no longer be needed. */
Damien Millereba71ba2000-04-29 23:57:08 +1000548void
549destroy_sensitive_data(void)
550{
Damien Miller0bc1bd82000-11-13 22:57:25 +1100551 int i;
552
553 if (sensitive_data.server_key) {
554 key_free(sensitive_data.server_key);
555 sensitive_data.server_key = NULL;
556 }
Damien Miller9f0f5c62001-12-21 14:45:46 +1100557 for (i = 0; i < options.num_host_key_files; i++) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100558 if (sensitive_data.host_keys[i]) {
559 key_free(sensitive_data.host_keys[i]);
560 sensitive_data.host_keys[i] = NULL;
561 }
Damien Miller0a80ca12010-02-27 07:55:05 +1100562 if (sensitive_data.host_certificates[i]) {
563 key_free(sensitive_data.host_certificates[i]);
564 sensitive_data.host_certificates[i] = NULL;
565 }
Damien Miller0bc1bd82000-11-13 22:57:25 +1100566 }
567 sensitive_data.ssh1_host_key = NULL;
Ben Lindstromeb648a72001-03-05 06:00:29 +0000568 memset(sensitive_data.ssh1_cookie, 0, SSH_SESSION_KEY_LENGTH);
Damien Miller0bc1bd82000-11-13 22:57:25 +1100569}
Damien Miller0bc1bd82000-11-13 22:57:25 +1100570
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000571/* Demote private to public keys for network child */
572void
573demote_sensitive_data(void)
574{
575 Key *tmp;
576 int i;
577
578 if (sensitive_data.server_key) {
579 tmp = key_demote(sensitive_data.server_key);
580 key_free(sensitive_data.server_key);
581 sensitive_data.server_key = tmp;
582 }
583
584 for (i = 0; i < options.num_host_key_files; i++) {
585 if (sensitive_data.host_keys[i]) {
586 tmp = key_demote(sensitive_data.host_keys[i]);
587 key_free(sensitive_data.host_keys[i]);
588 sensitive_data.host_keys[i] = tmp;
589 if (tmp->type == KEY_RSA1)
590 sensitive_data.ssh1_host_key = tmp;
591 }
Damien Miller0a80ca12010-02-27 07:55:05 +1100592 /* Certs do not need demotion */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000593 }
594
595 /* We do not clear ssh1_host key and cookie. XXX - Okay Niels? */
596}
597
Ben Lindstrom08105192002-03-22 02:50:06 +0000598static void
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000599privsep_preauth_child(void)
600{
Darren Tucker64cee362009-06-21 20:26:17 +1000601 u_int32_t rnd[256];
Ben Lindstrom810af962002-07-04 00:11:40 +0000602 gid_t gidset[1];
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000603
604 /* Enable challenge-response authentication for privilege separation */
605 privsep_challenge_enable();
606
Damien Miller76e95da2008-03-07 18:31:24 +1100607 arc4random_stir();
Damien Miller354c48c2008-05-19 14:50:00 +1000608 arc4random_buf(rnd, sizeof(rnd));
Ben Lindstrom5a9d0ea2002-07-04 00:12:53 +0000609 RAND_seed(rnd, sizeof(rnd));
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000610
611 /* Demote the private keys to public keys. */
612 demote_sensitive_data();
613
Ben Lindstroma962c2f2002-07-04 00:14:17 +0000614 /* Change our root directory */
Ben Lindstrom7a7edf72002-03-22 02:42:37 +0000615 if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1)
616 fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR,
617 strerror(errno));
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000618 if (chdir("/") == -1)
Ben Lindstrom1ee9ec32002-03-22 03:14:45 +0000619 fatal("chdir(\"/\"): %s", strerror(errno));
Ben Lindstrom6328ab32002-03-22 02:54:23 +0000620
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000621 /* Drop our privileges */
Damien Miller6433df02006-09-07 10:36:43 +1000622 debug3("privsep user:group %u:%u", (u_int)privsep_pw->pw_uid,
623 (u_int)privsep_pw->pw_gid);
Ben Lindstromfbcc3f72002-06-25 23:24:18 +0000624#if 0
Darren Tuckerd5920482004-02-29 20:11:30 +1100625 /* XXX not ready, too heavy after chroot */
Damien Miller6433df02006-09-07 10:36:43 +1000626 do_setusercontext(privsep_pw);
Ben Lindstromfbcc3f72002-06-25 23:24:18 +0000627#else
Damien Miller6433df02006-09-07 10:36:43 +1000628 gidset[0] = privsep_pw->pw_gid;
Ben Lindstromfbcc3f72002-06-25 23:24:18 +0000629 if (setgroups(1, gidset) < 0)
630 fatal("setgroups: %.100s", strerror(errno));
Damien Miller6433df02006-09-07 10:36:43 +1000631 permanently_set_uid(privsep_pw);
Ben Lindstromfbcc3f72002-06-25 23:24:18 +0000632#endif
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000633}
634
Darren Tucker3e33cec2003-10-02 16:12:36 +1000635static int
636privsep_preauth(Authctxt *authctxt)
Ben Lindstrom943481c2002-03-22 03:43:46 +0000637{
Ben Lindstrom943481c2002-03-22 03:43:46 +0000638 int status;
639 pid_t pid;
Damien Miller69ff1df2011-06-23 08:30:03 +1000640 struct ssh_sandbox *box = NULL;
Ben Lindstrom943481c2002-03-22 03:43:46 +0000641
642 /* Set up unprivileged child process to deal with network data */
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000643 pmonitor = monitor_init();
Ben Lindstrom943481c2002-03-22 03:43:46 +0000644 /* Store a pointer to the kex for later rekeying */
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000645 pmonitor->m_pkex = &xxx_kex;
Ben Lindstrom943481c2002-03-22 03:43:46 +0000646
Damien Miller5a5c2b92012-07-31 12:21:34 +1000647 if (use_privsep == PRIVSEP_ON)
Damien Miller69ff1df2011-06-23 08:30:03 +1000648 box = ssh_sandbox_init();
Ben Lindstrom943481c2002-03-22 03:43:46 +0000649 pid = fork();
650 if (pid == -1) {
651 fatal("fork of unprivileged child failed");
652 } else if (pid != 0) {
Ben Lindstromce0f6342002-06-11 16:42:49 +0000653 debug2("Network child is on pid %ld", (long)pid);
Ben Lindstrom943481c2002-03-22 03:43:46 +0000654
Darren Tucker3b4b2d32012-07-02 18:54:31 +1000655 pmonitor->m_pid = pid;
Damien Miller69ff1df2011-06-23 08:30:03 +1000656 if (box != NULL)
657 ssh_sandbox_parent_preauth(box, pid);
Darren Tucker3e33cec2003-10-02 16:12:36 +1000658 monitor_child_preauth(authctxt, pmonitor);
Ben Lindstrom943481c2002-03-22 03:43:46 +0000659
660 /* Sync memory */
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000661 monitor_sync(pmonitor);
Ben Lindstrom943481c2002-03-22 03:43:46 +0000662
663 /* Wait for the child's exit status */
Damien Miller69ff1df2011-06-23 08:30:03 +1000664 while (waitpid(pid, &status, 0) < 0) {
Damien Miller9ee2c602011-09-22 21:38:30 +1000665 if (errno == EINTR)
666 continue;
667 pmonitor->m_pid = -1;
668 fatal("%s: waitpid: %s", __func__, strerror(errno));
Damien Miller69ff1df2011-06-23 08:30:03 +1000669 }
Damien Miller9ee2c602011-09-22 21:38:30 +1000670 privsep_is_preauth = 0;
671 pmonitor->m_pid = -1;
Damien Miller69ff1df2011-06-23 08:30:03 +1000672 if (WIFEXITED(status)) {
673 if (WEXITSTATUS(status) != 0)
674 fatal("%s: preauth child exited with status %d",
675 __func__, WEXITSTATUS(status));
676 } else if (WIFSIGNALED(status))
677 fatal("%s: preauth child terminated by signal %d",
678 __func__, WTERMSIG(status));
679 if (box != NULL)
680 ssh_sandbox_parent_finish(box);
681 return 1;
Ben Lindstrom943481c2002-03-22 03:43:46 +0000682 } else {
683 /* child */
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000684 close(pmonitor->m_sendfd);
Damien Miller8f0bf232011-06-20 14:42:23 +1000685 close(pmonitor->m_log_recvfd);
686
687 /* Arrange for logging to be sent to the monitor */
688 set_log_handler(mm_log_handler, pmonitor);
Ben Lindstrom943481c2002-03-22 03:43:46 +0000689
690 /* Demote the child */
691 if (getuid() == 0 || geteuid() == 0)
692 privsep_preauth_child();
Ben Lindstromf90f58d2002-03-26 01:53:03 +0000693 setproctitle("%s", "[net]");
Damien Miller69ff1df2011-06-23 08:30:03 +1000694 if (box != NULL)
695 ssh_sandbox_child(box);
696
697 return 0;
Ben Lindstrom943481c2002-03-22 03:43:46 +0000698 }
Ben Lindstrom943481c2002-03-22 03:43:46 +0000699}
700
Ben Lindstrom08105192002-03-22 02:50:06 +0000701static void
Ben Lindstrom943481c2002-03-22 03:43:46 +0000702privsep_postauth(Authctxt *authctxt)
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000703{
Damien Miller76e95da2008-03-07 18:31:24 +1100704 u_int32_t rnd[256];
Damien Miller76e95da2008-03-07 18:31:24 +1100705
Tim Rice9dd30812002-07-07 13:43:36 -0700706#ifdef DISABLE_FD_PASSING
Tim Rice8eff3192002-06-25 15:35:15 -0700707 if (1) {
708#else
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000709 if (authctxt->pw->pw_uid == 0 || options.use_login) {
Tim Rice8eff3192002-06-25 15:35:15 -0700710#endif
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000711 /* File descriptor passing is broken or root login */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000712 use_privsep = 0;
Darren Tucker45b01422005-10-03 18:20:00 +1000713 goto skip;
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000714 }
Ben Lindstrom6328ab32002-03-22 02:54:23 +0000715
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000716 /* New socket pair */
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000717 monitor_reinit(pmonitor);
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000718
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000719 pmonitor->m_pid = fork();
720 if (pmonitor->m_pid == -1)
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000721 fatal("fork of unprivileged child failed");
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000722 else if (pmonitor->m_pid != 0) {
Damien Millerb61f3fc2008-07-11 17:36:48 +1000723 verbose("User child is on pid %ld", (long)pmonitor->m_pid);
Darren Tuckereb578622004-08-12 23:08:14 +1000724 buffer_clear(&loginmsg);
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000725 monitor_child_postauth(pmonitor);
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000726
727 /* NEVERREACHED */
728 exit(0);
729 }
730
Damien Miller8f0bf232011-06-20 14:42:23 +1000731 /* child */
732
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000733 close(pmonitor->m_sendfd);
Damien Miller8f0bf232011-06-20 14:42:23 +1000734 pmonitor->m_sendfd = -1;
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000735
736 /* Demote the private keys to public keys. */
737 demote_sensitive_data();
738
Damien Miller76e95da2008-03-07 18:31:24 +1100739 arc4random_stir();
Damien Miller354c48c2008-05-19 14:50:00 +1000740 arc4random_buf(rnd, sizeof(rnd));
Damien Miller76e95da2008-03-07 18:31:24 +1100741 RAND_seed(rnd, sizeof(rnd));
742
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000743 /* Drop privileges */
744 do_setusercontext(authctxt->pw);
745
Darren Tucker45b01422005-10-03 18:20:00 +1000746 skip:
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000747 /* It is safe now to apply the key state */
Ben Lindstrom7339b2a2002-05-15 16:25:01 +0000748 monitor_apply_keystate(pmonitor);
Damien Miller9786e6e2005-07-26 21:54:56 +1000749
750 /*
751 * Tell the packet layer that authentication was successful, since
752 * this information is not part of the key state.
753 */
754 packet_set_authenticated();
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000755}
756
Ben Lindstrombba81212001-06-25 05:01:22 +0000757static char *
Damien Miller0bc1bd82000-11-13 22:57:25 +1100758list_hostkey_types(void)
759{
Damien Miller0e3b8722002-01-22 23:26:38 +1100760 Buffer b;
Damien Millerf58b58c2003-11-17 21:18:23 +1100761 const char *p;
762 char *ret;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100763 int i;
Damien Miller0a80ca12010-02-27 07:55:05 +1100764 Key *key;
Damien Miller0e3b8722002-01-22 23:26:38 +1100765
766 buffer_init(&b);
Damien Miller9f0f5c62001-12-21 14:45:46 +1100767 for (i = 0; i < options.num_host_key_files; i++) {
Damien Miller0a80ca12010-02-27 07:55:05 +1100768 key = sensitive_data.host_keys[i];
Damien Miller0bc1bd82000-11-13 22:57:25 +1100769 if (key == NULL)
770 continue;
Ben Lindstrom1c37c6a2001-12-06 18:00:18 +0000771 switch (key->type) {
Damien Miller0bc1bd82000-11-13 22:57:25 +1100772 case KEY_RSA:
773 case KEY_DSA:
Damien Millereb8b60e2010-08-31 22:41:14 +1000774 case KEY_ECDSA:
Damien Miller0e3b8722002-01-22 23:26:38 +1100775 if (buffer_len(&b) > 0)
776 buffer_append(&b, ",", 1);
777 p = key_ssh_name(key);
778 buffer_append(&b, p, strlen(p));
Damien Miller0bc1bd82000-11-13 22:57:25 +1100779 break;
780 }
Damien Miller0a80ca12010-02-27 07:55:05 +1100781 /* If the private key has a cert peer, then list that too */
782 key = sensitive_data.host_certificates[i];
783 if (key == NULL)
784 continue;
785 switch (key->type) {
Damien Miller4e270b02010-04-16 15:56:21 +1000786 case KEY_RSA_CERT_V00:
787 case KEY_DSA_CERT_V00:
Damien Miller0a80ca12010-02-27 07:55:05 +1100788 case KEY_RSA_CERT:
789 case KEY_DSA_CERT:
Damien Millereb8b60e2010-08-31 22:41:14 +1000790 case KEY_ECDSA_CERT:
Damien Miller0a80ca12010-02-27 07:55:05 +1100791 if (buffer_len(&b) > 0)
792 buffer_append(&b, ",", 1);
793 p = key_ssh_name(key);
794 buffer_append(&b, p, strlen(p));
795 break;
796 }
Damien Miller0bc1bd82000-11-13 22:57:25 +1100797 }
Damien Miller0e3b8722002-01-22 23:26:38 +1100798 buffer_append(&b, "\0", 1);
Damien Millerf58b58c2003-11-17 21:18:23 +1100799 ret = xstrdup(buffer_ptr(&b));
Damien Miller0e3b8722002-01-22 23:26:38 +1100800 buffer_free(&b);
Damien Millerf58b58c2003-11-17 21:18:23 +1100801 debug("list_hostkey_types: %s", ret);
802 return ret;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100803}
804
Damien Miller0a80ca12010-02-27 07:55:05 +1100805static Key *
806get_hostkey_by_type(int type, int need_private)
Damien Miller0bc1bd82000-11-13 22:57:25 +1100807{
808 int i;
Damien Miller0a80ca12010-02-27 07:55:05 +1100809 Key *key;
Ben Lindstrom822b6342002-06-23 21:38:49 +0000810
Damien Miller9f0f5c62001-12-21 14:45:46 +1100811 for (i = 0; i < options.num_host_key_files; i++) {
Damien Miller4e270b02010-04-16 15:56:21 +1000812 switch (type) {
813 case KEY_RSA_CERT_V00:
814 case KEY_DSA_CERT_V00:
815 case KEY_RSA_CERT:
816 case KEY_DSA_CERT:
Damien Millereb8b60e2010-08-31 22:41:14 +1000817 case KEY_ECDSA_CERT:
Damien Miller0a80ca12010-02-27 07:55:05 +1100818 key = sensitive_data.host_certificates[i];
Damien Miller4e270b02010-04-16 15:56:21 +1000819 break;
820 default:
Damien Miller0a80ca12010-02-27 07:55:05 +1100821 key = sensitive_data.host_keys[i];
Damien Miller4e270b02010-04-16 15:56:21 +1000822 break;
823 }
Damien Miller0bc1bd82000-11-13 22:57:25 +1100824 if (key != NULL && key->type == type)
Damien Miller0a80ca12010-02-27 07:55:05 +1100825 return need_private ?
826 sensitive_data.host_keys[i] : key;
Damien Miller0bc1bd82000-11-13 22:57:25 +1100827 }
828 return NULL;
Damien Millerb38eff82000-04-01 11:09:21 +1000829}
830
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000831Key *
Damien Miller0a80ca12010-02-27 07:55:05 +1100832get_hostkey_public_by_type(int type)
833{
834 return get_hostkey_by_type(type, 0);
835}
836
837Key *
838get_hostkey_private_by_type(int type)
839{
840 return get_hostkey_by_type(type, 1);
841}
842
843Key *
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000844get_hostkey_by_index(int ind)
845{
846 if (ind < 0 || ind >= options.num_host_key_files)
847 return (NULL);
848 return (sensitive_data.host_keys[ind]);
849}
850
851int
852get_hostkey_index(Key *key)
853{
854 int i;
Ben Lindstrom822b6342002-06-23 21:38:49 +0000855
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000856 for (i = 0; i < options.num_host_key_files; i++) {
Damien Miller0a80ca12010-02-27 07:55:05 +1100857 if (key_is_cert(key)) {
858 if (key == sensitive_data.host_certificates[i])
859 return (i);
860 } else {
861 if (key == sensitive_data.host_keys[i])
862 return (i);
863 }
Ben Lindstrom7a2073c2002-03-22 02:30:41 +0000864 }
865 return (-1);
866}
867
Damien Miller942da032000-08-18 13:59:06 +1000868/*
869 * returns 1 if connection should be dropped, 0 otherwise.
870 * dropping starts at connection #max_startups_begin with a probability
871 * of (max_startups_rate/100). the probability increases linearly until
872 * all connections are dropped for startups > max_startups
873 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000874static int
Damien Miller942da032000-08-18 13:59:06 +1000875drop_connection(int startups)
876{
Darren Tucker178fa662004-11-05 20:09:09 +1100877 int p, r;
Damien Miller942da032000-08-18 13:59:06 +1000878
879 if (startups < options.max_startups_begin)
880 return 0;
881 if (startups >= options.max_startups)
882 return 1;
883 if (options.max_startups_rate == 100)
884 return 1;
885
886 p = 100 - options.max_startups_rate;
887 p *= startups - options.max_startups_begin;
Darren Tucker178fa662004-11-05 20:09:09 +1100888 p /= options.max_startups - options.max_startups_begin;
Damien Miller942da032000-08-18 13:59:06 +1000889 p += options.max_startups_rate;
Damien Miller354c48c2008-05-19 14:50:00 +1000890 r = arc4random_uniform(100);
Damien Miller942da032000-08-18 13:59:06 +1000891
Darren Tucker3269b132004-11-05 20:20:59 +1100892 debug("drop_connection: p %d, r %d", p, r);
Damien Miller942da032000-08-18 13:59:06 +1000893 return (r < p) ? 1 : 0;
894}
895
Ben Lindstromade03f62001-12-06 18:22:17 +0000896static void
897usage(void)
898{
Damien Miller0c889cd2004-03-22 09:36:00 +1100899 fprintf(stderr, "%s, %s\n",
Damien Miller2aa6d3c2004-09-12 16:53:04 +1000900 SSH_RELEASE, SSLeay_version(SSLEAY_VERSION));
Damien Millerb4087862004-03-22 09:35:21 +1100901 fprintf(stderr,
Damien Miller0a80ca12010-02-27 07:55:05 +1100902"usage: sshd [-46DdeiqTt] [-b bits] [-C connection_spec] [-c host_cert_file]\n"
Damien Miller03d4d7e2013-04-23 15:21:06 +1000903" [-E log_file] [-f config_file] [-g login_grace_time]\n"
904" [-h host_key_file] [-k key_gen_time] [-o option] [-p port]\n"
905" [-u len]\n"
Damien Millerb4087862004-03-22 09:35:21 +1100906 );
Ben Lindstromade03f62001-12-06 18:22:17 +0000907 exit(1);
908}
909
Darren Tucker645ab752004-06-25 13:33:20 +1000910static void
911send_rexec_state(int fd, Buffer *conf)
912{
913 Buffer m;
914
915 debug3("%s: entering fd = %d config len %d", __func__, fd,
916 buffer_len(conf));
917
918 /*
919 * Protocol from reexec master to child:
920 * string configuration
921 * u_int ephemeral_key_follows
922 * bignum e (only if ephemeral_key_follows == 1)
923 * bignum n "
924 * bignum d "
925 * bignum iqmp "
926 * bignum p "
927 * bignum q "
Darren Tuckerc6f82192005-09-27 22:46:32 +1000928 * string rngseed (only if OpenSSL is not self-seeded)
Darren Tucker645ab752004-06-25 13:33:20 +1000929 */
930 buffer_init(&m);
931 buffer_put_cstring(&m, buffer_ptr(conf));
932
Darren Tuckerfc959702004-07-17 16:12:08 +1000933 if (sensitive_data.server_key != NULL &&
Darren Tucker645ab752004-06-25 13:33:20 +1000934 sensitive_data.server_key->type == KEY_RSA1) {
935 buffer_put_int(&m, 1);
936 buffer_put_bignum(&m, sensitive_data.server_key->rsa->e);
937 buffer_put_bignum(&m, sensitive_data.server_key->rsa->n);
938 buffer_put_bignum(&m, sensitive_data.server_key->rsa->d);
939 buffer_put_bignum(&m, sensitive_data.server_key->rsa->iqmp);
940 buffer_put_bignum(&m, sensitive_data.server_key->rsa->p);
941 buffer_put_bignum(&m, sensitive_data.server_key->rsa->q);
942 } else
943 buffer_put_int(&m, 0);
944
Darren Tuckerc6f82192005-09-27 22:46:32 +1000945#ifndef OPENSSL_PRNG_ONLY
946 rexec_send_rng_seed(&m);
947#endif
948
Darren Tucker645ab752004-06-25 13:33:20 +1000949 if (ssh_msg_send(fd, 0, &m) == -1)
950 fatal("%s: ssh_msg_send failed", __func__);
951
952 buffer_free(&m);
953
954 debug3("%s: done", __func__);
955}
956
957static void
958recv_rexec_state(int fd, Buffer *conf)
959{
960 Buffer m;
961 char *cp;
962 u_int len;
963
964 debug3("%s: entering fd = %d", __func__, fd);
965
966 buffer_init(&m);
967
968 if (ssh_msg_recv(fd, &m) == -1)
969 fatal("%s: ssh_msg_recv failed", __func__);
970 if (buffer_get_char(&m) != 0)
971 fatal("%s: rexec version mismatch", __func__);
972
973 cp = buffer_get_string(&m, &len);
974 if (conf != NULL)
975 buffer_append(conf, cp, len + 1);
Darren Tuckera627d422013-06-02 07:31:17 +1000976 free(cp);
Darren Tucker645ab752004-06-25 13:33:20 +1000977
978 if (buffer_get_int(&m)) {
979 if (sensitive_data.server_key != NULL)
980 key_free(sensitive_data.server_key);
981 sensitive_data.server_key = key_new_private(KEY_RSA1);
982 buffer_get_bignum(&m, sensitive_data.server_key->rsa->e);
983 buffer_get_bignum(&m, sensitive_data.server_key->rsa->n);
984 buffer_get_bignum(&m, sensitive_data.server_key->rsa->d);
985 buffer_get_bignum(&m, sensitive_data.server_key->rsa->iqmp);
986 buffer_get_bignum(&m, sensitive_data.server_key->rsa->p);
987 buffer_get_bignum(&m, sensitive_data.server_key->rsa->q);
988 rsa_generate_additional_parameters(
989 sensitive_data.server_key->rsa);
990 }
Darren Tuckerc6f82192005-09-27 22:46:32 +1000991
992#ifndef OPENSSL_PRNG_ONLY
993 rexec_recv_rng_seed(&m);
994#endif
995
Darren Tucker645ab752004-06-25 13:33:20 +1000996 buffer_free(&m);
997
998 debug3("%s: done", __func__);
999}
1000
Damien Millera1f68402006-08-19 00:31:39 +10001001/* Accept a connection from inetd */
1002static void
1003server_accept_inetd(int *sock_in, int *sock_out)
1004{
1005 int fd;
1006
1007 startup_pipe = -1;
1008 if (rexeced_flag) {
1009 close(REEXEC_CONFIG_PASS_FD);
1010 *sock_in = *sock_out = dup(STDIN_FILENO);
1011 if (!debug_flag) {
1012 startup_pipe = dup(REEXEC_STARTUP_PIPE_FD);
1013 close(REEXEC_STARTUP_PIPE_FD);
1014 }
1015 } else {
1016 *sock_in = dup(STDIN_FILENO);
1017 *sock_out = dup(STDOUT_FILENO);
1018 }
1019 /*
1020 * We intentionally do not close the descriptors 0, 1, and 2
1021 * as our code for setting the descriptors won't work if
1022 * ttyfd happens to be one of those.
1023 */
1024 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1025 dup2(fd, STDIN_FILENO);
1026 dup2(fd, STDOUT_FILENO);
1027 if (fd > STDOUT_FILENO)
1028 close(fd);
1029 }
1030 debug("inetd sockets after dupping: %d, %d", *sock_in, *sock_out);
1031}
1032
1033/*
1034 * Listen for TCP connections
1035 */
1036static void
1037server_listen(void)
1038{
1039 int ret, listen_sock, on = 1;
1040 struct addrinfo *ai;
1041 char ntop[NI_MAXHOST], strport[NI_MAXSERV];
1042
1043 for (ai = options.listen_addrs; ai; ai = ai->ai_next) {
1044 if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6)
1045 continue;
1046 if (num_listen_socks >= MAX_LISTEN_SOCKS)
1047 fatal("Too many listen sockets. "
1048 "Enlarge MAX_LISTEN_SOCKS");
1049 if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen,
1050 ntop, sizeof(ntop), strport, sizeof(strport),
1051 NI_NUMERICHOST|NI_NUMERICSERV)) != 0) {
1052 error("getnameinfo failed: %.100s",
Darren Tucker4abde772007-12-29 02:43:51 +11001053 ssh_gai_strerror(ret));
Damien Millera1f68402006-08-19 00:31:39 +10001054 continue;
1055 }
1056 /* Create socket for listening. */
Darren Tucker7bd98e72010-01-10 10:31:12 +11001057 listen_sock = socket(ai->ai_family, ai->ai_socktype,
1058 ai->ai_protocol);
Damien Millera1f68402006-08-19 00:31:39 +10001059 if (listen_sock < 0) {
1060 /* kernel may not support ipv6 */
1061 verbose("socket: %.100s", strerror(errno));
1062 continue;
1063 }
1064 if (set_nonblock(listen_sock) == -1) {
1065 close(listen_sock);
1066 continue;
1067 }
1068 /*
1069 * Set socket options.
1070 * Allow local port reuse in TIME_WAIT.
1071 */
1072 if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR,
1073 &on, sizeof(on)) == -1)
1074 error("setsockopt SO_REUSEADDR: %s", strerror(errno));
1075
Damien Miller49d2a282008-01-20 08:56:00 +11001076 /* Only communicate in IPv6 over AF_INET6 sockets. */
Damien Miller04ee0f82009-11-18 17:48:30 +11001077 if (ai->ai_family == AF_INET6)
1078 sock_set_v6only(listen_sock);
Damien Miller49d2a282008-01-20 08:56:00 +11001079
Damien Millera1f68402006-08-19 00:31:39 +10001080 debug("Bind to port %s on %s.", strport, ntop);
1081
1082 /* Bind the socket to the desired port. */
1083 if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) {
1084 error("Bind to port %s on %s failed: %.200s.",
1085 strport, ntop, strerror(errno));
1086 close(listen_sock);
1087 continue;
1088 }
1089 listen_socks[num_listen_socks] = listen_sock;
1090 num_listen_socks++;
1091
1092 /* Start listening on the port. */
1093 if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0)
1094 fatal("listen on [%s]:%s: %.100s",
1095 ntop, strport, strerror(errno));
1096 logit("Server listening on %s port %s.", ntop, strport);
1097 }
1098 freeaddrinfo(options.listen_addrs);
1099
1100 if (!num_listen_socks)
1101 fatal("Cannot bind any address.");
1102}
1103
1104/*
1105 * The main TCP accept loop. Note that, for the non-debug case, returns
1106 * from this function are in a forked subprocess.
1107 */
1108static void
1109server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s)
1110{
1111 fd_set *fdset;
1112 int i, j, ret, maxfd;
1113 int key_used = 0, startups = 0;
1114 int startup_p[2] = { -1 , -1 };
1115 struct sockaddr_storage from;
1116 socklen_t fromlen;
1117 pid_t pid;
1118
1119 /* setup fd set for accept */
1120 fdset = NULL;
1121 maxfd = 0;
1122 for (i = 0; i < num_listen_socks; i++)
1123 if (listen_socks[i] > maxfd)
1124 maxfd = listen_socks[i];
1125 /* pipes connected to unauthenticated childs */
1126 startup_pipes = xcalloc(options.max_startups, sizeof(int));
1127 for (i = 0; i < options.max_startups; i++)
1128 startup_pipes[i] = -1;
1129
1130 /*
1131 * Stay listening for connections until the system crashes or
1132 * the daemon is killed with a signal.
1133 */
1134 for (;;) {
1135 if (received_sighup)
1136 sighup_restart();
1137 if (fdset != NULL)
Darren Tuckera627d422013-06-02 07:31:17 +10001138 free(fdset);
Damien Millera1f68402006-08-19 00:31:39 +10001139 fdset = (fd_set *)xcalloc(howmany(maxfd + 1, NFDBITS),
1140 sizeof(fd_mask));
1141
1142 for (i = 0; i < num_listen_socks; i++)
1143 FD_SET(listen_socks[i], fdset);
1144 for (i = 0; i < options.max_startups; i++)
1145 if (startup_pipes[i] != -1)
1146 FD_SET(startup_pipes[i], fdset);
1147
1148 /* Wait in select until there is a connection. */
1149 ret = select(maxfd+1, fdset, NULL, NULL, NULL);
1150 if (ret < 0 && errno != EINTR)
1151 error("select: %.100s", strerror(errno));
1152 if (received_sigterm) {
1153 logit("Received signal %d; terminating.",
1154 (int) received_sigterm);
1155 close_listen_socks();
1156 unlink(options.pid_file);
Damien Miller26b57ce2011-05-05 14:15:09 +10001157 exit(received_sigterm == SIGTERM ? 0 : 255);
Damien Millera1f68402006-08-19 00:31:39 +10001158 }
1159 if (key_used && key_do_regen) {
1160 generate_ephemeral_server_key();
1161 key_used = 0;
1162 key_do_regen = 0;
1163 }
1164 if (ret < 0)
1165 continue;
1166
1167 for (i = 0; i < options.max_startups; i++)
1168 if (startup_pipes[i] != -1 &&
1169 FD_ISSET(startup_pipes[i], fdset)) {
1170 /*
1171 * the read end of the pipe is ready
1172 * if the child has closed the pipe
1173 * after successful authentication
1174 * or if the child has died
1175 */
1176 close(startup_pipes[i]);
1177 startup_pipes[i] = -1;
1178 startups--;
1179 }
1180 for (i = 0; i < num_listen_socks; i++) {
1181 if (!FD_ISSET(listen_socks[i], fdset))
1182 continue;
1183 fromlen = sizeof(from);
1184 *newsock = accept(listen_socks[i],
1185 (struct sockaddr *)&from, &fromlen);
1186 if (*newsock < 0) {
Damien Miller37f1c082013-04-23 15:20:43 +10001187 if (errno != EINTR && errno != EWOULDBLOCK &&
1188 errno != ECONNABORTED && errno != EAGAIN)
Damien Millera116d132012-04-22 11:23:46 +10001189 error("accept: %.100s",
1190 strerror(errno));
1191 if (errno == EMFILE || errno == ENFILE)
1192 usleep(100 * 1000);
Damien Millera1f68402006-08-19 00:31:39 +10001193 continue;
1194 }
1195 if (unset_nonblock(*newsock) == -1) {
1196 close(*newsock);
1197 continue;
1198 }
1199 if (drop_connection(startups) == 1) {
1200 debug("drop connection #%d", startups);
1201 close(*newsock);
1202 continue;
1203 }
1204 if (pipe(startup_p) == -1) {
1205 close(*newsock);
1206 continue;
1207 }
1208
1209 if (rexec_flag && socketpair(AF_UNIX,
1210 SOCK_STREAM, 0, config_s) == -1) {
1211 error("reexec socketpair: %s",
1212 strerror(errno));
1213 close(*newsock);
1214 close(startup_p[0]);
1215 close(startup_p[1]);
1216 continue;
1217 }
1218
1219 for (j = 0; j < options.max_startups; j++)
1220 if (startup_pipes[j] == -1) {
1221 startup_pipes[j] = startup_p[0];
1222 if (maxfd < startup_p[0])
1223 maxfd = startup_p[0];
1224 startups++;
1225 break;
1226 }
1227
1228 /*
1229 * Got connection. Fork a child to handle it, unless
1230 * we are in debugging mode.
1231 */
1232 if (debug_flag) {
1233 /*
1234 * In debugging mode. Close the listening
1235 * socket, and start processing the
1236 * connection without forking.
1237 */
1238 debug("Server will not fork when running in debugging mode.");
1239 close_listen_socks();
1240 *sock_in = *newsock;
1241 *sock_out = *newsock;
1242 close(startup_p[0]);
1243 close(startup_p[1]);
1244 startup_pipe = -1;
1245 pid = getpid();
1246 if (rexec_flag) {
1247 send_rexec_state(config_s[0],
1248 &cfg);
1249 close(config_s[0]);
1250 }
1251 break;
1252 }
1253
1254 /*
1255 * Normal production daemon. Fork, and have
1256 * the child process the connection. The
1257 * parent continues listening.
1258 */
Damien Miller1b06dc32006-08-31 03:24:41 +10001259 platform_pre_fork();
Damien Millera1f68402006-08-19 00:31:39 +10001260 if ((pid = fork()) == 0) {
1261 /*
1262 * Child. Close the listening and
1263 * max_startup sockets. Start using
1264 * the accepted socket. Reinitialize
1265 * logging (since our pid has changed).
1266 * We break out of the loop to handle
1267 * the connection.
1268 */
Damien Miller1b06dc32006-08-31 03:24:41 +10001269 platform_post_fork_child();
Damien Millera1f68402006-08-19 00:31:39 +10001270 startup_pipe = startup_p[1];
1271 close_startup_pipes();
1272 close_listen_socks();
1273 *sock_in = *newsock;
1274 *sock_out = *newsock;
1275 log_init(__progname,
1276 options.log_level,
1277 options.log_facility,
1278 log_stderr);
1279 if (rexec_flag)
1280 close(config_s[0]);
1281 break;
1282 }
1283
1284 /* Parent. Stay in the loop. */
Damien Miller1b06dc32006-08-31 03:24:41 +10001285 platform_post_fork_parent(pid);
Damien Millera1f68402006-08-19 00:31:39 +10001286 if (pid < 0)
1287 error("fork: %.100s", strerror(errno));
1288 else
1289 debug("Forked child %ld.", (long)pid);
1290
1291 close(startup_p[1]);
1292
1293 if (rexec_flag) {
1294 send_rexec_state(config_s[0], &cfg);
1295 close(config_s[0]);
1296 close(config_s[1]);
1297 }
1298
1299 /*
1300 * Mark that the key has been used (it
1301 * was "given" to the child).
1302 */
1303 if ((options.protocol & SSH_PROTO_1) &&
1304 key_used == 0) {
1305 /* Schedule server key regeneration alarm. */
1306 signal(SIGALRM, key_regeneration_alarm);
1307 alarm(options.key_regeneration_time);
1308 key_used = 1;
1309 }
1310
1311 close(*newsock);
1312
1313 /*
1314 * Ensure that our random state differs
1315 * from that of the child
1316 */
1317 arc4random_stir();
1318 }
1319
1320 /* child process check (or debug mode) */
1321 if (num_listen_socks < 0)
1322 break;
1323 }
1324}
1325
1326
Damien Miller95def091999-11-25 00:26:21 +11001327/*
1328 * Main program for the daemon.
1329 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001330int
1331main(int ac, char **av)
1332{
Damien Miller95def091999-11-25 00:26:21 +11001333 extern char *optarg;
1334 extern int optind;
Damien Miller0a80ca12010-02-27 07:55:05 +11001335 int opt, i, j, on = 1;
Damien Miller386c6a22004-06-30 22:40:20 +10001336 int sock_in = -1, sock_out = -1, newsock = -1;
Damien Miller95def091999-11-25 00:26:21 +11001337 const char *remote_ip;
1338 int remote_port;
Damien Miller03d4d7e2013-04-23 15:21:06 +10001339 char *line, *logfile = NULL;
Damien Millera1f68402006-08-19 00:31:39 +10001340 int config_s[2] = { -1 , -1 };
Damien Millera6e3f012012-11-04 23:21:40 +11001341 u_int n;
Damien Millerb61f3fc2008-07-11 17:36:48 +10001342 u_int64_t ibytes, obytes;
Damien Miller6ca16c62008-06-16 07:50:58 +10001343 mode_t new_umask;
Ben Lindstromd0fca422001-03-26 13:44:06 +00001344 Key *key;
Darren Tucker3e33cec2003-10-02 16:12:36 +10001345 Authctxt *authctxt;
Darren Tuckerfbcf8272012-05-19 19:37:01 +10001346 struct connection_info *connection_info = get_connection_info(0, 0);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001347
Kevin Steves0ea1d9d2002-04-25 18:17:04 +00001348#ifdef HAVE_SECUREWARE
1349 (void)set_auth_parameters(ac, av);
1350#endif
Damien Miller59d3d5b2003-08-22 09:34:41 +10001351 __progname = ssh_get_progname(av[0]);
Damien Millerf9b625c2000-07-09 22:42:32 +10001352
Damien Millera8ed44b2003-01-10 09:53:12 +11001353 /* Save argv. Duplicate so setproctitle emulation doesn't clobber it */
Damien Millerb8c656e2000-06-28 15:22:41 +10001354 saved_argc = ac;
Darren Tucker17c5d032004-06-25 14:22:23 +10001355 rexec_argc = ac;
Darren Tuckerd8093e42006-05-04 16:24:34 +10001356 saved_argv = xcalloc(ac + 1, sizeof(*saved_argv));
Damien Millera8ed44b2003-01-10 09:53:12 +11001357 for (i = 0; i < ac; i++)
1358 saved_argv[i] = xstrdup(av[i]);
Damien Miller04cb5362003-05-15 21:29:10 +10001359 saved_argv[i] = NULL;
Damien Millera8ed44b2003-01-10 09:53:12 +11001360
1361#ifndef HAVE_SETPROCTITLE
1362 /* Prepare for later setproctitle emulation */
1363 compat_init_setproctitle(ac, av);
Damien Millerf2e3e9d2003-06-02 12:15:54 +10001364 av = saved_argv;
Damien Millera8ed44b2003-01-10 09:53:12 +11001365#endif
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001366
Damien Millerbfba3542004-03-22 09:29:57 +11001367 if (geteuid() == 0 && setgroups(0, NULL) == -1)
1368 debug("setgroups(): %.200s", strerror(errno));
1369
Darren Tuckerce321d82005-10-03 18:11:24 +10001370 /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */
1371 sanitise_stdfd();
1372
Damien Miller95def091999-11-25 00:26:21 +11001373 /* Initialize configuration options to their default values. */
1374 initialize_server_options(&options);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001375
Damien Miller95def091999-11-25 00:26:21 +11001376 /* Parse command-line arguments. */
Damien Miller03d4d7e2013-04-23 15:21:06 +10001377 while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:C:dDeE:iqrtQRT46")) != -1) {
Damien Miller95def091999-11-25 00:26:21 +11001378 switch (opt) {
Damien Miller34132e52000-01-14 15:45:46 +11001379 case '4':
Darren Tucker0f383232005-01-20 10:57:56 +11001380 options.address_family = AF_INET;
Damien Miller34132e52000-01-14 15:45:46 +11001381 break;
1382 case '6':
Darren Tucker0f383232005-01-20 10:57:56 +11001383 options.address_family = AF_INET6;
Damien Miller34132e52000-01-14 15:45:46 +11001384 break;
Damien Miller95def091999-11-25 00:26:21 +11001385 case 'f':
1386 config_file_name = optarg;
1387 break;
Damien Miller0a80ca12010-02-27 07:55:05 +11001388 case 'c':
1389 if (options.num_host_cert_files >= MAX_HOSTCERTS) {
1390 fprintf(stderr, "too many host certificates.\n");
1391 exit(1);
1392 }
1393 options.host_cert_files[options.num_host_cert_files++] =
1394 derelativise_path(optarg);
1395 break;
Damien Miller95def091999-11-25 00:26:21 +11001396 case 'd':
Darren Tuckere98dfa32003-07-19 19:54:31 +10001397 if (debug_flag == 0) {
Damien Millere4340be2000-09-16 13:29:08 +11001398 debug_flag = 1;
1399 options.log_level = SYSLOG_LEVEL_DEBUG1;
Darren Tuckere98dfa32003-07-19 19:54:31 +10001400 } else if (options.log_level < SYSLOG_LEVEL_DEBUG3)
Damien Millere4340be2000-09-16 13:29:08 +11001401 options.log_level++;
Damien Miller95def091999-11-25 00:26:21 +11001402 break;
Ben Lindstromc72745a2000-12-02 19:03:54 +00001403 case 'D':
1404 no_daemon_flag = 1;
1405 break;
Damien Miller03d4d7e2013-04-23 15:21:06 +10001406 case 'E':
1407 logfile = xstrdup(optarg);
1408 /* FALLTHROUGH */
Ben Lindstrom9fce9f02001-04-11 23:10:09 +00001409 case 'e':
1410 log_stderr = 1;
1411 break;
Damien Miller95def091999-11-25 00:26:21 +11001412 case 'i':
1413 inetd_flag = 1;
1414 break;
Darren Tucker645ab752004-06-25 13:33:20 +10001415 case 'r':
1416 rexec_flag = 0;
1417 break;
1418 case 'R':
1419 rexeced_flag = 1;
1420 inetd_flag = 1;
1421 break;
Damien Miller95def091999-11-25 00:26:21 +11001422 case 'Q':
Ben Lindstromd5390202001-01-29 08:07:43 +00001423 /* ignored */
Damien Miller95def091999-11-25 00:26:21 +11001424 break;
1425 case 'q':
1426 options.log_level = SYSLOG_LEVEL_QUIET;
1427 break;
1428 case 'b':
Damien Millerf0b15df2006-03-26 13:59:20 +11001429 options.server_key_bits = (int)strtonum(optarg, 256,
1430 32768, NULL);
Damien Miller95def091999-11-25 00:26:21 +11001431 break;
1432 case 'p':
Damien Miller34132e52000-01-14 15:45:46 +11001433 options.ports_from_cmdline = 1;
Damien Millere4340be2000-09-16 13:29:08 +11001434 if (options.num_ports >= MAX_PORTS) {
1435 fprintf(stderr, "too many ports.\n");
1436 exit(1);
1437 }
Ben Lindstrom19066a12001-04-12 23:39:26 +00001438 options.ports[options.num_ports++] = a2port(optarg);
Damien Miller3dc71ad2009-01-28 16:31:22 +11001439 if (options.ports[options.num_ports-1] <= 0) {
Ben Lindstrom19066a12001-04-12 23:39:26 +00001440 fprintf(stderr, "Bad port number.\n");
1441 exit(1);
1442 }
Damien Miller95def091999-11-25 00:26:21 +11001443 break;
1444 case 'g':
Ben Lindstrom1bda4c82001-06-05 19:59:08 +00001445 if ((options.login_grace_time = convtime(optarg)) == -1) {
1446 fprintf(stderr, "Invalid login grace time.\n");
1447 exit(1);
1448 }
Damien Miller95def091999-11-25 00:26:21 +11001449 break;
1450 case 'k':
Ben Lindstrom1bda4c82001-06-05 19:59:08 +00001451 if ((options.key_regeneration_time = convtime(optarg)) == -1) {
1452 fprintf(stderr, "Invalid key regeneration interval.\n");
1453 exit(1);
1454 }
Damien Miller95def091999-11-25 00:26:21 +11001455 break;
1456 case 'h':
Damien Miller0bc1bd82000-11-13 22:57:25 +11001457 if (options.num_host_key_files >= MAX_HOSTKEYS) {
1458 fprintf(stderr, "too many host keys.\n");
1459 exit(1);
1460 }
Darren Tucker88b6fb22010-01-13 22:44:29 +11001461 options.host_key_files[options.num_host_key_files++] =
1462 derelativise_path(optarg);
Damien Miller95def091999-11-25 00:26:21 +11001463 break;
Ben Lindstrom794325a2001-08-06 21:09:07 +00001464 case 't':
1465 test_flag = 1;
1466 break;
Darren Tuckere7140f22008-06-10 23:01:51 +10001467 case 'T':
1468 test_flag = 2;
1469 break;
1470 case 'C':
Darren Tuckerfbcf8272012-05-19 19:37:01 +10001471 if (parse_server_match_testspec(connection_info,
1472 optarg) == -1)
1473 exit(1);
Darren Tuckere7140f22008-06-10 23:01:51 +10001474 break;
Damien Miller942da032000-08-18 13:59:06 +10001475 case 'u':
Damien Millerf0b15df2006-03-26 13:59:20 +11001476 utmp_len = (u_int)strtonum(optarg, 0, MAXHOSTNAMELEN+1, NULL);
Ben Lindstrom41daec72002-07-23 21:15:13 +00001477 if (utmp_len > MAXHOSTNAMELEN) {
1478 fprintf(stderr, "Invalid utmp length.\n");
1479 exit(1);
1480 }
Damien Miller942da032000-08-18 13:59:06 +10001481 break;
Ben Lindstromade03f62001-12-06 18:22:17 +00001482 case 'o':
Damien Millerb9997192003-12-17 16:29:22 +11001483 line = xstrdup(optarg);
1484 if (process_server_config_line(&options, line,
Darren Tuckerfbcf8272012-05-19 19:37:01 +10001485 "command-line", 0, NULL, NULL) != 0)
Damien Miller9f0f5c62001-12-21 14:45:46 +11001486 exit(1);
Darren Tuckera627d422013-06-02 07:31:17 +10001487 free(line);
Ben Lindstromade03f62001-12-06 18:22:17 +00001488 break;
Damien Miller95def091999-11-25 00:26:21 +11001489 case '?':
1490 default:
Ben Lindstromade03f62001-12-06 18:22:17 +00001491 usage();
1492 break;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001493 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001494 }
Darren Tucker645ab752004-06-25 13:33:20 +10001495 if (rexeced_flag || inetd_flag)
1496 rexec_flag = 0;
Damien Miller2ee0c432008-03-07 18:31:47 +11001497 if (!test_flag && (rexec_flag && (av[0] == NULL || *av[0] != '/')))
Darren Tucker645ab752004-06-25 13:33:20 +10001498 fatal("sshd re-exec requires execution with an absolute path");
1499 if (rexeced_flag)
Damien Miller035a5b42004-06-26 08:16:31 +10001500 closefrom(REEXEC_MIN_FREE_FD);
1501 else
1502 closefrom(REEXEC_DEVCRYPTO_RESERVED_FD);
Darren Tucker645ab752004-06-25 13:33:20 +10001503
Damien Miller4314c2b2010-09-10 11:12:09 +10001504 OpenSSL_add_all_algorithms();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001505
Damien Miller03d4d7e2013-04-23 15:21:06 +10001506 /* If requested, redirect the logs to the specified logfile. */
1507 if (logfile != NULL) {
1508 log_redirect_stderr_to(logfile);
Darren Tuckera627d422013-06-02 07:31:17 +10001509 free(logfile);
Damien Miller03d4d7e2013-04-23 15:21:06 +10001510 }
Damien Miller34132e52000-01-14 15:45:46 +11001511 /*
1512 * Force logging to stderr until we have loaded the private host
1513 * key (unless started from inetd)
1514 */
Kevin Stevesec84dc12000-12-13 17:45:15 +00001515 log_init(__progname,
Damien Miller5aa5d782002-02-08 22:01:54 +11001516 options.log_level == SYSLOG_LEVEL_NOT_SET ?
1517 SYSLOG_LEVEL_INFO : options.log_level,
1518 options.log_facility == SYSLOG_FACILITY_NOT_SET ?
1519 SYSLOG_FACILITY_AUTH : options.log_facility,
Ben Lindstromc2faa4a2002-11-09 15:50:03 +00001520 log_stderr || !inetd_flag);
Damien Miller34132e52000-01-14 15:45:46 +11001521
Darren Tucker86c093d2004-03-08 22:59:03 +11001522 /*
1523 * Unset KRB5CCNAME, otherwise the user's session may inherit it from
1524 * root's environment
Damien Miller94cf4c82005-07-17 17:04:47 +10001525 */
Darren Tucker9dc6c7d2005-02-02 18:30:33 +11001526 if (getenv("KRB5CCNAME") != NULL)
Tim Ricee3609c92012-02-14 10:03:30 -08001527 (void) unsetenv("KRB5CCNAME");
Darren Tucker9dc6c7d2005-02-02 18:30:33 +11001528
Tim Rice81ed5182002-09-25 17:38:46 -07001529#ifdef _UNICOS
Darren Tucker12984962004-05-24 13:37:13 +10001530 /* Cray can define user privs drop all privs now!
Ben Lindstrom6db66ff2001-08-06 23:29:16 +00001531 * Not needed on PRIV_SU systems!
1532 */
1533 drop_cray_privs();
1534#endif
1535
Darren Tucker645ab752004-06-25 13:33:20 +10001536 sensitive_data.server_key = NULL;
1537 sensitive_data.ssh1_host_key = NULL;
1538 sensitive_data.have_ssh1_key = 0;
1539 sensitive_data.have_ssh2_key = 0;
1540
Darren Tuckere7140f22008-06-10 23:01:51 +10001541 /*
1542 * If we're doing an extended config test, make sure we have all of
1543 * the parameters we need. If we're not doing an extended test,
1544 * do not silently ignore connection test params.
1545 */
Darren Tuckerfbcf8272012-05-19 19:37:01 +10001546 if (test_flag >= 2 && server_match_spec_complete(connection_info) == 0)
Darren Tuckere7140f22008-06-10 23:01:51 +10001547 fatal("user, host and addr are all required when testing "
1548 "Match configs");
Darren Tuckerfbcf8272012-05-19 19:37:01 +10001549 if (test_flag < 2 && server_match_spec_complete(connection_info) >= 0)
Darren Tuckere7140f22008-06-10 23:01:51 +10001550 fatal("Config test connection parameter (-C) provided without "
1551 "test mode (-T)");
1552
Darren Tucker645ab752004-06-25 13:33:20 +10001553 /* Fetch our configuration */
1554 buffer_init(&cfg);
1555 if (rexeced_flag)
Damien Miller035a5b42004-06-26 08:16:31 +10001556 recv_rexec_state(REEXEC_CONFIG_PASS_FD, &cfg);
Darren Tucker645ab752004-06-25 13:33:20 +10001557 else
1558 load_server_config(config_file_name, &cfg);
1559
Darren Tucker45150472006-07-12 22:34:17 +10001560 parse_server_config(&options, rexeced_flag ? "rexec" : config_file_name,
Darren Tuckerfbcf8272012-05-19 19:37:01 +10001561 &cfg, NULL);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001562
Darren Tuckerc6f82192005-09-27 22:46:32 +10001563 seed_rng();
1564
Damien Miller95def091999-11-25 00:26:21 +11001565 /* Fill in default values for those options not explicitly set. */
1566 fill_default_server_options(&options);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001567
Darren Tucker97b1bb52007-03-21 20:38:53 +11001568 /* challenge-response is implemented via keyboard interactive */
1569 if (options.challenge_response_authentication)
1570 options.kbd_interactive_authentication = 1;
1571
Damien Millerd0d10992012-11-04 22:23:14 +11001572 /* Check that options are sensible */
1573 if (options.authorized_keys_command_user == NULL &&
1574 (options.authorized_keys_command != NULL &&
1575 strcasecmp(options.authorized_keys_command, "none") != 0))
1576 fatal("AuthorizedKeysCommand set without "
1577 "AuthorizedKeysCommandUser");
1578
Damien Millera6e3f012012-11-04 23:21:40 +11001579 /*
1580 * Check whether there is any path through configured auth methods.
1581 * Unfortunately it is not possible to verify this generally before
1582 * daemonisation in the presence of Match block, but this catches
1583 * and warns for trivial misconfigurations that could break login.
1584 */
1585 if (options.num_auth_methods != 0) {
1586 if ((options.protocol & SSH_PROTO_1))
1587 fatal("AuthenticationMethods is not supported with "
1588 "SSH protocol 1");
1589 for (n = 0; n < options.num_auth_methods; n++) {
1590 if (auth2_methods_valid(options.auth_methods[n],
1591 1) == 0)
1592 break;
1593 }
1594 if (n >= options.num_auth_methods)
1595 fatal("AuthenticationMethods cannot be satisfied by "
1596 "enabled authentication methods");
1597 }
1598
Darren Tucker7bd98e72010-01-10 10:31:12 +11001599 /* set default channel AF */
Darren Tucker0f383232005-01-20 10:57:56 +11001600 channel_set_af(options.address_family);
1601
Damien Miller95def091999-11-25 00:26:21 +11001602 /* Check that there are no remaining arguments. */
1603 if (optind < ac) {
1604 fprintf(stderr, "Extra argument %s.\n", av[optind]);
1605 exit(1);
1606 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001607
Damien Miller22e8a1e2013-02-12 11:04:48 +11001608 debug("sshd version %s, %s", SSH_VERSION,
1609 SSLeay_version(SSLEAY_VERSION));
Damien Miller2ccf6611999-11-15 15:25:10 +11001610
Darren Tuckerdf0e4382006-11-07 11:28:40 +11001611 /* Store privilege separation user for later use if required. */
1612 if ((privsep_pw = getpwnam(SSH_PRIVSEP_USER)) == NULL) {
1613 if (use_privsep || options.kerberos_authentication)
1614 fatal("Privilege separation user %s does not exist",
1615 SSH_PRIVSEP_USER);
1616 } else {
1617 memset(privsep_pw->pw_passwd, 0, strlen(privsep_pw->pw_passwd));
1618 privsep_pw = pwcopy(privsep_pw);
Darren Tuckerf60845f2013-06-02 08:07:31 +10001619 free(privsep_pw->pw_passwd);
Darren Tuckerdf0e4382006-11-07 11:28:40 +11001620 privsep_pw->pw_passwd = xstrdup("*");
1621 }
Damien Miller6433df02006-09-07 10:36:43 +10001622 endpwent();
1623
Damien Miller0bc1bd82000-11-13 22:57:25 +11001624 /* load private host keys */
Damien Miller07d86be2006-03-26 14:19:21 +11001625 sensitive_data.host_keys = xcalloc(options.num_host_key_files,
Ben Lindstroma962c2f2002-07-04 00:14:17 +00001626 sizeof(Key *));
Damien Miller9f0f5c62001-12-21 14:45:46 +11001627 for (i = 0; i < options.num_host_key_files; i++)
Ben Lindstrom46c16222000-12-22 01:43:59 +00001628 sensitive_data.host_keys[i] = NULL;
Damien Millereba71ba2000-04-29 23:57:08 +10001629
Damien Miller9f0f5c62001-12-21 14:45:46 +11001630 for (i = 0; i < options.num_host_key_files; i++) {
Ben Lindstromd0fca422001-03-26 13:44:06 +00001631 key = key_load_private(options.host_key_files[i], "", NULL);
1632 sensitive_data.host_keys[i] = key;
Damien Miller0bc1bd82000-11-13 22:57:25 +11001633 if (key == NULL) {
Ben Lindstrom15f33862001-04-16 02:00:02 +00001634 error("Could not load host key: %s",
1635 options.host_key_files[i]);
Ben Lindstromd0fca422001-03-26 13:44:06 +00001636 sensitive_data.host_keys[i] = NULL;
Damien Miller0bc1bd82000-11-13 22:57:25 +11001637 continue;
1638 }
Ben Lindstrom1c37c6a2001-12-06 18:00:18 +00001639 switch (key->type) {
Damien Miller0bc1bd82000-11-13 22:57:25 +11001640 case KEY_RSA1:
1641 sensitive_data.ssh1_host_key = key;
1642 sensitive_data.have_ssh1_key = 1;
1643 break;
1644 case KEY_RSA:
1645 case KEY_DSA:
Damien Millereb8b60e2010-08-31 22:41:14 +10001646 case KEY_ECDSA:
Damien Miller0bc1bd82000-11-13 22:57:25 +11001647 sensitive_data.have_ssh2_key = 1;
1648 break;
1649 }
Ben Lindstromd0fca422001-03-26 13:44:06 +00001650 debug("private host key: #%d type %d %s", i, key->type,
1651 key_type(key));
Damien Miller0bc1bd82000-11-13 22:57:25 +11001652 }
1653 if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) {
Damien Miller996acd22003-04-09 20:59:48 +10001654 logit("Disabling protocol version 1. Could not load host key");
Damien Millereba71ba2000-04-29 23:57:08 +10001655 options.protocol &= ~SSH_PROTO_1;
1656 }
Damien Miller0bc1bd82000-11-13 22:57:25 +11001657 if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) {
Damien Miller996acd22003-04-09 20:59:48 +10001658 logit("Disabling protocol version 2. Could not load host key");
Damien Miller0bc1bd82000-11-13 22:57:25 +11001659 options.protocol &= ~SSH_PROTO_2;
Damien Millereba71ba2000-04-29 23:57:08 +10001660 }
Kevin Stevesadf74cd2001-02-05 14:22:50 +00001661 if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) {
Damien Miller996acd22003-04-09 20:59:48 +10001662 logit("sshd: no hostkeys available -- exiting.");
Damien Miller95def091999-11-25 00:26:21 +11001663 exit(1);
1664 }
Damien Miller95def091999-11-25 00:26:21 +11001665
Damien Miller0a80ca12010-02-27 07:55:05 +11001666 /*
1667 * Load certificates. They are stored in an array at identical
1668 * indices to the public keys that they relate to.
1669 */
1670 sensitive_data.host_certificates = xcalloc(options.num_host_key_files,
1671 sizeof(Key *));
1672 for (i = 0; i < options.num_host_key_files; i++)
1673 sensitive_data.host_certificates[i] = NULL;
1674
1675 for (i = 0; i < options.num_host_cert_files; i++) {
1676 key = key_load_public(options.host_cert_files[i], NULL);
1677 if (key == NULL) {
1678 error("Could not load host certificate: %s",
1679 options.host_cert_files[i]);
1680 continue;
1681 }
1682 if (!key_is_cert(key)) {
1683 error("Certificate file is not a certificate: %s",
1684 options.host_cert_files[i]);
1685 key_free(key);
1686 continue;
1687 }
1688 /* Find matching private key */
1689 for (j = 0; j < options.num_host_key_files; j++) {
1690 if (key_equal_public(key,
1691 sensitive_data.host_keys[j])) {
1692 sensitive_data.host_certificates[j] = key;
1693 break;
1694 }
1695 }
1696 if (j >= options.num_host_key_files) {
1697 error("No matching private key for certificate: %s",
1698 options.host_cert_files[i]);
1699 key_free(key);
1700 continue;
1701 }
1702 sensitive_data.host_certificates[j] = key;
1703 debug("host certificate: #%d type %d %s", j, key->type,
1704 key_type(key));
1705 }
Damien Millereba71ba2000-04-29 23:57:08 +10001706 /* Check certain values for sanity. */
1707 if (options.protocol & SSH_PROTO_1) {
1708 if (options.server_key_bits < 512 ||
1709 options.server_key_bits > 32768) {
1710 fprintf(stderr, "Bad server key size.\n");
1711 exit(1);
1712 }
1713 /*
1714 * Check that server and host key lengths differ sufficiently. This
1715 * is necessary to make double encryption work with rsaref. Oh, I
1716 * hate software patents. I dont know if this can go? Niels
1717 */
1718 if (options.server_key_bits >
Ben Lindstrom822b6342002-06-23 21:38:49 +00001719 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) -
1720 SSH_KEY_BITS_RESERVED && options.server_key_bits <
1721 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
1722 SSH_KEY_BITS_RESERVED) {
Damien Millereba71ba2000-04-29 23:57:08 +10001723 options.server_key_bits =
Ben Lindstrom822b6342002-06-23 21:38:49 +00001724 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
1725 SSH_KEY_BITS_RESERVED;
Damien Millereba71ba2000-04-29 23:57:08 +10001726 debug("Forcing server key to %d bits to make it differ from host key.",
1727 options.server_key_bits);
1728 }
1729 }
1730
Ben Lindstroma26ea632002-06-06 20:46:25 +00001731 if (use_privsep) {
Ben Lindstroma26ea632002-06-06 20:46:25 +00001732 struct stat st;
1733
Ben Lindstroma26ea632002-06-06 20:46:25 +00001734 if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) ||
1735 (S_ISDIR(st.st_mode) == 0))
1736 fatal("Missing privilege separation directory: %s",
1737 _PATH_PRIVSEP_CHROOT_DIR);
Ben Lindstrom59627352002-06-27 18:02:21 +00001738
1739#ifdef HAVE_CYGWIN
1740 if (check_ntsec(_PATH_PRIVSEP_CHROOT_DIR) &&
1741 (st.st_uid != getuid () ||
1742 (st.st_mode & (S_IWGRP|S_IWOTH)) != 0))
1743#else
Ben Lindstrom2dfacb32002-06-23 00:33:47 +00001744 if (st.st_uid != 0 || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)
Ben Lindstrom59627352002-06-27 18:02:21 +00001745#endif
Damien Miller180fc5b2003-02-24 11:50:18 +11001746 fatal("%s must be owned by root and not group or "
1747 "world-writable.", _PATH_PRIVSEP_CHROOT_DIR);
Ben Lindstroma26ea632002-06-06 20:46:25 +00001748 }
1749
Darren Tuckere7140f22008-06-10 23:01:51 +10001750 if (test_flag > 1) {
Darren Tuckerfbcf8272012-05-19 19:37:01 +10001751 if (server_match_spec_complete(connection_info) == 1)
1752 parse_server_match_config(&options, connection_info);
Darren Tuckere7140f22008-06-10 23:01:51 +10001753 dump_config(&options);
1754 }
1755
Ben Lindstrom794325a2001-08-06 21:09:07 +00001756 /* Configuration looks good, so exit if in test mode. */
1757 if (test_flag)
1758 exit(0);
1759
Damien Miller87aea252002-05-10 12:20:24 +10001760 /*
1761 * Clear out any supplemental groups we may have inherited. This
1762 * prevents inadvertent creation of files with bad modes (in the
Damien Millera8e06ce2003-11-21 23:48:55 +11001763 * portable version at least, it's certainly possible for PAM
1764 * to create a file, and we can't control the code in every
Damien Miller87aea252002-05-10 12:20:24 +10001765 * module which might be used).
1766 */
1767 if (setgroups(0, NULL) < 0)
1768 debug("setgroups() failed: %.200s", strerror(errno));
1769
Darren Tucker645ab752004-06-25 13:33:20 +10001770 if (rexec_flag) {
Damien Miller07d86be2006-03-26 14:19:21 +11001771 rexec_argv = xcalloc(rexec_argc + 2, sizeof(char *));
Darren Tucker645ab752004-06-25 13:33:20 +10001772 for (i = 0; i < rexec_argc; i++) {
1773 debug("rexec_argv[%d]='%s'", i, saved_argv[i]);
1774 rexec_argv[i] = saved_argv[i];
1775 }
1776 rexec_argv[rexec_argc] = "-R";
1777 rexec_argv[rexec_argc + 1] = NULL;
1778 }
1779
Damien Miller6ca16c62008-06-16 07:50:58 +10001780 /* Ensure that umask disallows at least group and world write */
1781 new_umask = umask(0077) | 0022;
1782 (void) umask(new_umask);
1783
Damien Millereba71ba2000-04-29 23:57:08 +10001784 /* Initialize the log (it is reinitialized below in case we forked). */
Darren Tuckerea7c8122005-01-20 11:03:08 +11001785 if (debug_flag && (!inetd_flag || rexeced_flag))
Damien Miller95def091999-11-25 00:26:21 +11001786 log_stderr = 1;
Kevin Stevesec84dc12000-12-13 17:45:15 +00001787 log_init(__progname, options.log_level, options.log_facility, log_stderr);
Damien Miller95def091999-11-25 00:26:21 +11001788
Damien Millereba71ba2000-04-29 23:57:08 +10001789 /*
1790 * If not in debugging mode, and not started from inetd, disconnect
1791 * from the controlling terminal, and fork. The original process
1792 * exits.
1793 */
Ben Lindstromc72745a2000-12-02 19:03:54 +00001794 if (!(debug_flag || inetd_flag || no_daemon_flag)) {
Damien Miller95def091999-11-25 00:26:21 +11001795#ifdef TIOCNOTTY
1796 int fd;
1797#endif /* TIOCNOTTY */
1798 if (daemon(0, 0) < 0)
1799 fatal("daemon() failed: %.200s", strerror(errno));
1800
1801 /* Disconnect from the controlling tty. */
1802#ifdef TIOCNOTTY
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00001803 fd = open(_PATH_TTY, O_RDWR | O_NOCTTY);
Damien Miller95def091999-11-25 00:26:21 +11001804 if (fd >= 0) {
1805 (void) ioctl(fd, TIOCNOTTY, NULL);
1806 close(fd);
1807 }
1808#endif /* TIOCNOTTY */
1809 }
1810 /* Reinitialize the log (because of the fork above). */
Kevin Stevesec84dc12000-12-13 17:45:15 +00001811 log_init(__progname, options.log_level, options.log_facility, log_stderr);
Damien Miller95def091999-11-25 00:26:21 +11001812
Damien Miller95def091999-11-25 00:26:21 +11001813 /* Initialize the random number generator. */
1814 arc4random_stir();
1815
1816 /* Chdir to the root directory so that the current disk can be
1817 unmounted if desired. */
Darren Tuckerdbee3082013-05-16 20:32:29 +10001818 if (chdir("/") == -1)
1819 error("chdir(\"/\"): %s", strerror(errno));
Damien Miller9f0f5c62001-12-21 14:45:46 +11001820
Ben Lindstromde71cda2001-03-24 00:43:26 +00001821 /* ignore SIGPIPE */
1822 signal(SIGPIPE, SIG_IGN);
Damien Miller95def091999-11-25 00:26:21 +11001823
Damien Millera1f68402006-08-19 00:31:39 +10001824 /* Get a connection, either from inetd or a listening TCP socket */
Damien Miller95def091999-11-25 00:26:21 +11001825 if (inetd_flag) {
Damien Millera1f68402006-08-19 00:31:39 +10001826 server_accept_inetd(&sock_in, &sock_out);
Damien Miller95def091999-11-25 00:26:21 +11001827 } else {
Darren Tuckerc8802aa2009-12-08 13:39:48 +11001828 platform_pre_listen();
Damien Millera1f68402006-08-19 00:31:39 +10001829 server_listen();
Damien Miller34132e52000-01-14 15:45:46 +11001830
Ben Lindstrom98097862001-06-25 05:10:20 +00001831 if (options.protocol & SSH_PROTO_1)
1832 generate_ephemeral_server_key();
1833
Ben Lindstrom98097862001-06-25 05:10:20 +00001834 signal(SIGHUP, sighup_handler);
Damien Millera1f68402006-08-19 00:31:39 +10001835 signal(SIGCHLD, main_sigchld_handler);
Ben Lindstrom98097862001-06-25 05:10:20 +00001836 signal(SIGTERM, sigterm_handler);
1837 signal(SIGQUIT, sigterm_handler);
1838
Damien Millera1f68402006-08-19 00:31:39 +10001839 /*
1840 * Write out the pid file after the sigterm handler
1841 * is setup and the listen sockets are bound
1842 */
Damien Miller95def091999-11-25 00:26:21 +11001843 if (!debug_flag) {
Damien Millera1f68402006-08-19 00:31:39 +10001844 FILE *f = fopen(options.pid_file, "w");
1845
Darren Tuckere5327042003-07-03 13:40:44 +10001846 if (f == NULL) {
1847 error("Couldn't create pid file \"%s\": %s",
1848 options.pid_file, strerror(errno));
1849 } else {
Ben Lindstromce0f6342002-06-11 16:42:49 +00001850 fprintf(f, "%ld\n", (long) getpid());
Damien Miller95def091999-11-25 00:26:21 +11001851 fclose(f);
1852 }
1853 }
Damien Miller95def091999-11-25 00:26:21 +11001854
Damien Millera1f68402006-08-19 00:31:39 +10001855 /* Accept a connection and return in a forked child */
1856 server_accept_loop(&sock_in, &sock_out,
1857 &newsock, config_s);
Damien Miller95def091999-11-25 00:26:21 +11001858 }
1859
1860 /* This is the child processing a new connection. */
Damien Miller57aae982004-03-08 23:11:25 +11001861 setproctitle("%s", "[accepted]");
Damien Miller95def091999-11-25 00:26:21 +11001862
Darren Tucker6832b832004-08-12 22:36:51 +10001863 /*
1864 * Create a new session and process group since the 4.4BSD
1865 * setlogin() affects the entire process group. We don't
1866 * want the child to be able to affect the parent.
1867 */
1868#if !defined(SSHD_ACQUIRES_CTTY)
1869 /*
1870 * If setsid is called, on some platforms sshd will later acquire a
1871 * controlling terminal which will result in "could not set
1872 * controlling tty" errors.
1873 */
1874 if (!debug_flag && !inetd_flag && setsid() < 0)
1875 error("setsid: %.100s", strerror(errno));
1876#endif
1877
Darren Tucker645ab752004-06-25 13:33:20 +10001878 if (rexec_flag) {
1879 int fd;
1880
Damien Miller035a5b42004-06-26 08:16:31 +10001881 debug("rexec start in %d out %d newsock %d pipe %d sock %d",
1882 sock_in, sock_out, newsock, startup_pipe, config_s[0]);
Darren Tucker645ab752004-06-25 13:33:20 +10001883 dup2(newsock, STDIN_FILENO);
1884 dup2(STDIN_FILENO, STDOUT_FILENO);
1885 if (startup_pipe == -1)
Damien Miller035a5b42004-06-26 08:16:31 +10001886 close(REEXEC_STARTUP_PIPE_FD);
Darren Tucker645ab752004-06-25 13:33:20 +10001887 else
Damien Miller035a5b42004-06-26 08:16:31 +10001888 dup2(startup_pipe, REEXEC_STARTUP_PIPE_FD);
Darren Tucker645ab752004-06-25 13:33:20 +10001889
Damien Miller035a5b42004-06-26 08:16:31 +10001890 dup2(config_s[1], REEXEC_CONFIG_PASS_FD);
Darren Tucker645ab752004-06-25 13:33:20 +10001891 close(config_s[1]);
Darren Tuckerd8835932004-08-12 22:42:29 +10001892 if (startup_pipe != -1)
1893 close(startup_pipe);
Damien Miller035a5b42004-06-26 08:16:31 +10001894
Darren Tucker645ab752004-06-25 13:33:20 +10001895 execv(rexec_argv[0], rexec_argv);
1896
1897 /* Reexec has failed, fall back and continue */
1898 error("rexec of %s failed: %s", rexec_argv[0], strerror(errno));
Damien Miller035a5b42004-06-26 08:16:31 +10001899 recv_rexec_state(REEXEC_CONFIG_PASS_FD, NULL);
Darren Tucker645ab752004-06-25 13:33:20 +10001900 log_init(__progname, options.log_level,
1901 options.log_facility, log_stderr);
1902
1903 /* Clean up fds */
Damien Miller035a5b42004-06-26 08:16:31 +10001904 startup_pipe = REEXEC_STARTUP_PIPE_FD;
Darren Tucker645ab752004-06-25 13:33:20 +10001905 close(config_s[1]);
Damien Miller035a5b42004-06-26 08:16:31 +10001906 close(REEXEC_CONFIG_PASS_FD);
1907 newsock = sock_out = sock_in = dup(STDIN_FILENO);
Darren Tucker645ab752004-06-25 13:33:20 +10001908 if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) {
1909 dup2(fd, STDIN_FILENO);
1910 dup2(fd, STDOUT_FILENO);
1911 if (fd > STDERR_FILENO)
1912 close(fd);
1913 }
Damien Miller035a5b42004-06-26 08:16:31 +10001914 debug("rexec cleanup in %d out %d newsock %d pipe %d sock %d",
1915 sock_in, sock_out, newsock, startup_pipe, config_s[0]);
Darren Tucker645ab752004-06-25 13:33:20 +10001916 }
1917
Damien Miller133d9d32010-01-30 17:30:04 +11001918 /* Executed child processes don't need these. */
1919 fcntl(sock_out, F_SETFD, FD_CLOEXEC);
1920 fcntl(sock_in, F_SETFD, FD_CLOEXEC);
1921
Damien Miller5428f641999-11-25 11:54:57 +11001922 /*
1923 * Disable the key regeneration alarm. We will not regenerate the
1924 * key since we are no longer in a position to give it to anyone. We
1925 * will not restart on SIGHUP since it no longer makes sense.
1926 */
Damien Miller95def091999-11-25 00:26:21 +11001927 alarm(0);
1928 signal(SIGALRM, SIG_DFL);
1929 signal(SIGHUP, SIG_DFL);
1930 signal(SIGTERM, SIG_DFL);
1931 signal(SIGQUIT, SIG_DFL);
1932 signal(SIGCHLD, SIG_DFL);
Damien Miller4e0f5e12000-08-29 11:05:50 +11001933 signal(SIGINT, SIG_DFL);
Damien Miller95def091999-11-25 00:26:21 +11001934
Damien Miller5428f641999-11-25 11:54:57 +11001935 /*
1936 * Register our connection. This turns encryption off because we do
1937 * not have a key.
1938 */
Damien Miller95def091999-11-25 00:26:21 +11001939 packet_set_connection(sock_in, sock_out);
Damien Miller9786e6e2005-07-26 21:54:56 +10001940 packet_set_server();
Damien Miller95def091999-11-25 00:26:21 +11001941
Damien Miller4f1d6b22005-05-26 11:59:32 +10001942 /* Set SO_KEEPALIVE if requested. */
1943 if (options.tcp_keep_alive && packet_connection_is_on_socket() &&
1944 setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) < 0)
1945 error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno));
1946
Damien Miller677257f2005-06-17 12:55:03 +10001947 if ((remote_port = get_remote_port()) < 0) {
1948 debug("get_remote_port failed");
1949 cleanup_exit(255);
1950 }
Damien Miller4d3fd542005-11-05 15:13:24 +11001951
1952 /*
1953 * We use get_canonical_hostname with usedns = 0 instead of
1954 * get_remote_ipaddr here so IP options will be checked.
1955 */
Damien Millereb13e552006-06-13 13:03:53 +10001956 (void) get_canonical_hostname(0);
1957 /*
1958 * The rest of the code depends on the fact that
1959 * get_remote_ipaddr() caches the remote ip, even if
1960 * the socket goes away.
1961 */
1962 remote_ip = get_remote_ipaddr();
Damien Miller95def091999-11-25 00:26:21 +11001963
Darren Tucker2e0cf0d2005-02-08 21:52:47 +11001964#ifdef SSH_AUDIT_EVENTS
Darren Tucker269a1ea2005-02-03 00:20:53 +11001965 audit_connection_from(remote_ip, remote_port);
1966#endif
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001967#ifdef LIBWRAP
Darren Tucker1f1e17b2008-02-28 23:20:48 +11001968 allow_severity = options.log_facility|LOG_INFO;
1969 deny_severity = options.log_facility|LOG_WARNING;
Damien Miller6a4a4b92001-11-12 11:07:11 +11001970 /* Check whether logins are denied from this host. */
Darren Tucker586b0b92004-06-25 13:34:31 +10001971 if (packet_connection_is_on_socket()) {
Damien Miller95def091999-11-25 00:26:21 +11001972 struct request_info req;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001973
Ben Lindstromce89dac2001-09-12 16:58:04 +00001974 request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0);
Damien Miller95def091999-11-25 00:26:21 +11001975 fromhost(&req);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001976
Damien Miller95def091999-11-25 00:26:21 +11001977 if (!hosts_access(&req)) {
Damien Miller6a4a4b92001-11-12 11:07:11 +11001978 debug("Connection refused by tcp wrapper");
Ben Lindstrom7de696e2001-03-29 00:45:12 +00001979 refuse(&req);
Damien Miller6a4a4b92001-11-12 11:07:11 +11001980 /* NOTREACHED */
1981 fatal("libwrap refuse returns");
Damien Miller95def091999-11-25 00:26:21 +11001982 }
Damien Miller95def091999-11-25 00:26:21 +11001983 }
Damien Miller34132e52000-01-14 15:45:46 +11001984#endif /* LIBWRAP */
Damien Miller6a4a4b92001-11-12 11:07:11 +11001985
Damien Miller95def091999-11-25 00:26:21 +11001986 /* Log the connection. */
1987 verbose("Connection from %.500s port %d", remote_ip, remote_port);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001988
Damien Miller5428f641999-11-25 11:54:57 +11001989 /*
Damien Miller788f2122005-11-05 15:14:59 +11001990 * We don't want to listen forever unless the other side
Damien Miller5428f641999-11-25 11:54:57 +11001991 * successfully authenticates itself. So we set up an alarm which is
1992 * cleared after successful authentication. A limit of zero
Damien Miller788f2122005-11-05 15:14:59 +11001993 * indicates no limit. Note that we don't set the alarm in debugging
Damien Miller5428f641999-11-25 11:54:57 +11001994 * mode; it is just annoying to have the server exit just when you
1995 * are about to discover the bug.
1996 */
Ben Lindstrom5ade9ab2003-08-25 01:16:21 +00001997 signal(SIGALRM, grace_alarm_handler);
Damien Miller95def091999-11-25 00:26:21 +11001998 if (!debug_flag)
1999 alarm(options.login_grace_time);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002000
Damien Millerb38eff82000-04-01 11:09:21 +10002001 sshd_exchange_identification(sock_in, sock_out);
Darren Tuckerec960f22003-08-13 20:37:05 +10002002
Darren Tucker58911162008-01-01 20:33:09 +11002003 /* In inetd mode, generate ephemeral key only for proto 1 connections */
2004 if (!compat20 && inetd_flag && sensitive_data.server_key == NULL)
2005 generate_ephemeral_server_key();
2006
Damien Miller95def091999-11-25 00:26:21 +11002007 packet_set_nonblocking();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002008
Darren Tucker3e33cec2003-10-02 16:12:36 +10002009 /* allocate authentication context */
Damien Miller07d86be2006-03-26 14:19:21 +11002010 authctxt = xcalloc(1, sizeof(*authctxt));
Darren Tucker3e33cec2003-10-02 16:12:36 +10002011
Darren Tuckerf3bb4342005-03-31 21:39:25 +10002012 authctxt->loginmsg = &loginmsg;
2013
Darren Tucker3e33cec2003-10-02 16:12:36 +10002014 /* XXX global for cleanup, access from other modules */
2015 the_authctxt = authctxt;
2016
Darren Tucker5c14c732005-01-24 21:55:49 +11002017 /* prepare buffer to collect messages to display to user after login */
2018 buffer_init(&loginmsg);
Darren Tuckercd70e1b2010-03-07 23:05:17 +11002019 auth_debug_reset();
Darren Tucker5c14c732005-01-24 21:55:49 +11002020
Ben Lindstrom943481c2002-03-22 03:43:46 +00002021 if (use_privsep)
Darren Tucker3e33cec2003-10-02 16:12:36 +10002022 if (privsep_preauth(authctxt) == 1)
Ben Lindstrom943481c2002-03-22 03:43:46 +00002023 goto authenticated;
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002024
Damien Miller396691a2000-01-20 22:44:08 +11002025 /* perform the key exchange */
Damien Miller396691a2000-01-20 22:44:08 +11002026 /* authenticate user and start session */
Damien Millerefb4afe2000-04-12 18:45:05 +10002027 if (compat20) {
2028 do_ssh2_kex();
Darren Tucker3e33cec2003-10-02 16:12:36 +10002029 do_authentication2(authctxt);
Damien Millerefb4afe2000-04-12 18:45:05 +10002030 } else {
2031 do_ssh1_kex();
Darren Tucker3e33cec2003-10-02 16:12:36 +10002032 do_authentication(authctxt);
Damien Millerefb4afe2000-04-12 18:45:05 +10002033 }
Ben Lindstrom943481c2002-03-22 03:43:46 +00002034 /*
2035 * If we use privilege separation, the unprivileged child transfers
2036 * the current keystate and exits
2037 */
2038 if (use_privsep) {
Ben Lindstrom7339b2a2002-05-15 16:25:01 +00002039 mm_send_keystate(pmonitor);
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002040 exit(0);
Ben Lindstrom943481c2002-03-22 03:43:46 +00002041 }
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002042
2043 authenticated:
Damien Miller7bff1a92005-12-24 14:59:12 +11002044 /*
2045 * Cancel the alarm we set to limit the time taken for
2046 * authentication.
2047 */
2048 alarm(0);
2049 signal(SIGALRM, SIG_DFL);
Damien Miller3f8123c2006-08-19 00:32:46 +10002050 authctxt->authenticated = 1;
Damien Miller7bff1a92005-12-24 14:59:12 +11002051 if (startup_pipe != -1) {
2052 close(startup_pipe);
2053 startup_pipe = -1;
2054 }
2055
Darren Tucker2e0cf0d2005-02-08 21:52:47 +11002056#ifdef SSH_AUDIT_EVENTS
2057 audit_event(SSH_AUTH_SUCCESS);
Darren Tucker269a1ea2005-02-03 00:20:53 +11002058#endif
2059
Darren Tucker52358d62008-03-11 22:58:25 +11002060#ifdef GSSAPI
2061 if (options.gss_authentication) {
2062 temporarily_use_uid(authctxt->pw);
2063 ssh_gssapi_storecreds();
2064 restore_uid();
2065 }
2066#endif
2067#ifdef USE_PAM
2068 if (options.use_pam) {
2069 do_pam_setcred(1);
2070 do_pam_session();
2071 }
2072#endif
2073
Ben Lindstrom6328ab32002-03-22 02:54:23 +00002074 /*
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002075 * In privilege separation, we fork another child and prepare
2076 * file descriptor passing.
2077 */
2078 if (use_privsep) {
Ben Lindstrom943481c2002-03-22 03:43:46 +00002079 privsep_postauth(authctxt);
2080 /* the monitor process [priv] will not return */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002081 if (!compat20)
2082 destroy_sensitive_data();
2083 }
Ben Lindstrom73ab9ba2002-03-22 01:27:35 +00002084
Darren Tucker3fc464e2008-06-13 06:42:45 +10002085 packet_set_timeout(options.client_alive_interval,
2086 options.client_alive_count_max);
2087
Darren Tucker3e33cec2003-10-02 16:12:36 +10002088 /* Start session. */
Ben Lindstrom73ab9ba2002-03-22 01:27:35 +00002089 do_authenticated(authctxt);
2090
Damien Miller3a5b0232002-03-13 13:19:42 +11002091 /* The connection has been terminated. */
Damien Millerb61f3fc2008-07-11 17:36:48 +10002092 packet_get_state(MODE_IN, NULL, NULL, NULL, &ibytes);
2093 packet_get_state(MODE_OUT, NULL, NULL, NULL, &obytes);
Damien Miller821de0a2011-01-11 17:20:29 +11002094 verbose("Transferred: sent %llu, received %llu bytes",
2095 (unsigned long long)obytes, (unsigned long long)ibytes);
Damien Millerb61f3fc2008-07-11 17:36:48 +10002096
2097 verbose("Closing connection to %.500s port %d", remote_ip, remote_port);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002098
Damien Millerbeb4ba51999-12-28 15:09:35 +11002099#ifdef USE_PAM
Damien Miller4e448a32003-05-14 15:11:48 +10002100 if (options.use_pam)
2101 finish_pam();
Damien Millerbeb4ba51999-12-28 15:09:35 +11002102#endif /* USE_PAM */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002103
Darren Tucker2b59a6d2005-03-06 22:38:51 +11002104#ifdef SSH_AUDIT_EVENTS
2105 PRIVSEP(audit_event(SSH_CONNECTION_CLOSE));
2106#endif
2107
Damien Miller95def091999-11-25 00:26:21 +11002108 packet_close();
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002109
2110 if (use_privsep)
2111 mm_terminate();
2112
Damien Miller95def091999-11-25 00:26:21 +11002113 exit(0);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002114}
2115
Damien Miller95def091999-11-25 00:26:21 +11002116/*
Ben Lindstromabcb1452002-03-22 01:10:21 +00002117 * Decrypt session_key_int using our private server key and private host key
2118 * (key with larger modulus first).
2119 */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002120int
Ben Lindstromabcb1452002-03-22 01:10:21 +00002121ssh1_session_key(BIGNUM *session_key_int)
2122{
2123 int rsafail = 0;
2124
Damien Millerf0b15df2006-03-26 13:59:20 +11002125 if (BN_cmp(sensitive_data.server_key->rsa->n,
2126 sensitive_data.ssh1_host_key->rsa->n) > 0) {
Ben Lindstromabcb1452002-03-22 01:10:21 +00002127 /* Server key has bigger modulus. */
2128 if (BN_num_bits(sensitive_data.server_key->rsa->n) <
Damien Millerf0b15df2006-03-26 13:59:20 +11002129 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) +
2130 SSH_KEY_BITS_RESERVED) {
2131 fatal("do_connection: %s: "
2132 "server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d",
Ben Lindstromabcb1452002-03-22 01:10:21 +00002133 get_remote_ipaddr(),
2134 BN_num_bits(sensitive_data.server_key->rsa->n),
2135 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
2136 SSH_KEY_BITS_RESERVED);
2137 }
2138 if (rsa_private_decrypt(session_key_int, session_key_int,
2139 sensitive_data.server_key->rsa) <= 0)
2140 rsafail++;
2141 if (rsa_private_decrypt(session_key_int, session_key_int,
2142 sensitive_data.ssh1_host_key->rsa) <= 0)
2143 rsafail++;
2144 } else {
2145 /* Host key has bigger modulus (or they are equal). */
2146 if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) <
Damien Millerf0b15df2006-03-26 13:59:20 +11002147 BN_num_bits(sensitive_data.server_key->rsa->n) +
2148 SSH_KEY_BITS_RESERVED) {
2149 fatal("do_connection: %s: "
2150 "host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d",
Ben Lindstromabcb1452002-03-22 01:10:21 +00002151 get_remote_ipaddr(),
2152 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n),
2153 BN_num_bits(sensitive_data.server_key->rsa->n),
2154 SSH_KEY_BITS_RESERVED);
2155 }
2156 if (rsa_private_decrypt(session_key_int, session_key_int,
2157 sensitive_data.ssh1_host_key->rsa) < 0)
2158 rsafail++;
2159 if (rsa_private_decrypt(session_key_int, session_key_int,
2160 sensitive_data.server_key->rsa) < 0)
2161 rsafail++;
2162 }
2163 return (rsafail);
2164}
2165/*
Damien Miller396691a2000-01-20 22:44:08 +11002166 * SSH1 key exchange
Damien Miller95def091999-11-25 00:26:21 +11002167 */
Ben Lindstrombba81212001-06-25 05:01:22 +00002168static void
Ben Lindstrom46c16222000-12-22 01:43:59 +00002169do_ssh1_kex(void)
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002170{
Damien Miller95def091999-11-25 00:26:21 +11002171 int i, len;
Damien Miller7650bc62001-01-30 09:27:26 +11002172 int rsafail = 0;
Damien Miller95def091999-11-25 00:26:21 +11002173 BIGNUM *session_key_int;
Ben Lindstrom46c16222000-12-22 01:43:59 +00002174 u_char session_key[SSH_SESSION_KEY_LENGTH];
2175 u_char cookie[8];
2176 u_int cipher_type, auth_mask, protocol_flags;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002177
Damien Miller5428f641999-11-25 11:54:57 +11002178 /*
2179 * Generate check bytes that the client must send back in the user
2180 * packet in order for it to be accepted; this is used to defy ip
2181 * spoofing attacks. Note that this only works against somebody
2182 * doing IP spoofing from a remote machine; any machine on the local
2183 * network can still see outgoing packets and catch the random
2184 * cookie. This only affects rhosts authentication, and this is one
2185 * of the reasons why it is inherently insecure.
2186 */
Damien Miller354c48c2008-05-19 14:50:00 +10002187 arc4random_buf(cookie, sizeof(cookie));
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002188
Damien Miller5428f641999-11-25 11:54:57 +11002189 /*
2190 * Send our public key. We include in the packet 64 bits of random
2191 * data that must be matched in the reply in order to prevent IP
2192 * spoofing.
2193 */
Damien Miller95def091999-11-25 00:26:21 +11002194 packet_start(SSH_SMSG_PUBLIC_KEY);
2195 for (i = 0; i < 8; i++)
Damien Miller396691a2000-01-20 22:44:08 +11002196 packet_put_char(cookie[i]);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002197
Damien Miller95def091999-11-25 00:26:21 +11002198 /* Store our public server RSA key. */
Damien Miller0bc1bd82000-11-13 22:57:25 +11002199 packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n));
2200 packet_put_bignum(sensitive_data.server_key->rsa->e);
2201 packet_put_bignum(sensitive_data.server_key->rsa->n);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002202
Damien Miller95def091999-11-25 00:26:21 +11002203 /* Store our public host RSA key. */
Damien Miller0bc1bd82000-11-13 22:57:25 +11002204 packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
2205 packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e);
2206 packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002207
Damien Miller95def091999-11-25 00:26:21 +11002208 /* Put protocol flags. */
2209 packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002210
Damien Miller95def091999-11-25 00:26:21 +11002211 /* Declare which ciphers we support. */
Damien Miller874d77b2000-10-14 16:23:11 +11002212 packet_put_int(cipher_mask_ssh1(0));
Damien Miller95def091999-11-25 00:26:21 +11002213
2214 /* Declare supported authentication types. */
2215 auth_mask = 0;
Damien Miller95def091999-11-25 00:26:21 +11002216 if (options.rhosts_rsa_authentication)
2217 auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA;
2218 if (options.rsa_authentication)
2219 auth_mask |= 1 << SSH_AUTH_RSA;
Ben Lindstrom551ea372001-06-05 18:56:16 +00002220 if (options.challenge_response_authentication == 1)
Damien Miller95def091999-11-25 00:26:21 +11002221 auth_mask |= 1 << SSH_AUTH_TIS;
Damien Miller95def091999-11-25 00:26:21 +11002222 if (options.password_authentication)
2223 auth_mask |= 1 << SSH_AUTH_PASSWORD;
2224 packet_put_int(auth_mask);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002225
Damien Miller95def091999-11-25 00:26:21 +11002226 /* Send the packet and wait for it to be sent. */
2227 packet_send();
2228 packet_write_wait();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002229
Damien Miller0bc1bd82000-11-13 22:57:25 +11002230 debug("Sent %d bit server key and %d bit host key.",
2231 BN_num_bits(sensitive_data.server_key->rsa->n),
2232 BN_num_bits(sensitive_data.ssh1_host_key->rsa->n));
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002233
Damien Miller95def091999-11-25 00:26:21 +11002234 /* Read clients reply (cipher type and session key). */
Damien Millerdff50992002-01-22 23:16:32 +11002235 packet_read_expect(SSH_CMSG_SESSION_KEY);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002236
Damien Miller50945fa1999-12-09 10:31:37 +11002237 /* Get cipher type and check whether we accept this. */
Damien Miller95def091999-11-25 00:26:21 +11002238 cipher_type = packet_get_char();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002239
Damien Miller874d77b2000-10-14 16:23:11 +11002240 if (!(cipher_mask_ssh1(0) & (1 << cipher_type)))
Damien Miller50945fa1999-12-09 10:31:37 +11002241 packet_disconnect("Warning: client selects unsupported cipher.");
2242
Damien Miller95def091999-11-25 00:26:21 +11002243 /* Get check bytes from the packet. These must match those we
2244 sent earlier with the public key packet. */
2245 for (i = 0; i < 8; i++)
Damien Miller396691a2000-01-20 22:44:08 +11002246 if (cookie[i] != packet_get_char())
Damien Miller95def091999-11-25 00:26:21 +11002247 packet_disconnect("IP Spoofing check bytes do not match.");
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002248
Damien Miller95def091999-11-25 00:26:21 +11002249 debug("Encryption type: %.200s", cipher_name(cipher_type));
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002250
Damien Miller95def091999-11-25 00:26:21 +11002251 /* Get the encrypted integer. */
Damien Millerda755162002-01-22 23:09:22 +11002252 if ((session_key_int = BN_new()) == NULL)
2253 fatal("do_ssh1_kex: BN_new failed");
Damien Millerd432ccf2002-01-22 23:14:44 +11002254 packet_get_bignum(session_key_int);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002255
Damien Miller95def091999-11-25 00:26:21 +11002256 protocol_flags = packet_get_int();
2257 packet_set_protocol_flags(protocol_flags);
Damien Miller48b03fc2002-01-22 23:11:40 +11002258 packet_check_eom();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002259
Ben Lindstromabcb1452002-03-22 01:10:21 +00002260 /* Decrypt session_key_int using host/server keys */
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002261 rsafail = PRIVSEP(ssh1_session_key(session_key_int));
2262
Damien Miller5428f641999-11-25 11:54:57 +11002263 /*
2264 * Extract session key from the decrypted integer. The key is in the
2265 * least significant 256 bits of the integer; the first byte of the
2266 * key is in the highest bits.
2267 */
Damien Miller7650bc62001-01-30 09:27:26 +11002268 if (!rsafail) {
Darren Tucker0bc85572006-11-07 23:14:41 +11002269 (void) BN_mask_bits(session_key_int, sizeof(session_key) * 8);
Damien Miller7650bc62001-01-30 09:27:26 +11002270 len = BN_num_bytes(session_key_int);
Damien Millereccb9de2005-06-17 12:59:34 +10002271 if (len < 0 || (u_int)len > sizeof(session_key)) {
Darren Tucker0bc85572006-11-07 23:14:41 +11002272 error("do_ssh1_kex: bad session key len from %s: "
Ben Lindstrom31ca54a2001-02-09 02:11:24 +00002273 "session_key_int %d > sizeof(session_key) %lu",
2274 get_remote_ipaddr(), len, (u_long)sizeof(session_key));
Damien Miller7650bc62001-01-30 09:27:26 +11002275 rsafail++;
2276 } else {
2277 memset(session_key, 0, sizeof(session_key));
2278 BN_bn2bin(session_key_int,
2279 session_key + sizeof(session_key) - len);
Ben Lindstromeb648a72001-03-05 06:00:29 +00002280
Darren Tuckere14e0052004-05-13 16:30:44 +10002281 derive_ssh1_session_id(
Darren Tuckerfc959702004-07-17 16:12:08 +10002282 sensitive_data.ssh1_host_key->rsa->n,
Darren Tuckere14e0052004-05-13 16:30:44 +10002283 sensitive_data.server_key->rsa->n,
2284 cookie, session_id);
Ben Lindstromeb648a72001-03-05 06:00:29 +00002285 /*
2286 * Xor the first 16 bytes of the session key with the
2287 * session id.
2288 */
2289 for (i = 0; i < 16; i++)
2290 session_key[i] ^= session_id[i];
Damien Miller7650bc62001-01-30 09:27:26 +11002291 }
2292 }
2293 if (rsafail) {
Ben Lindstromeb648a72001-03-05 06:00:29 +00002294 int bytes = BN_num_bytes(session_key_int);
Ben Lindstrom13c5d3b2002-02-26 18:00:48 +00002295 u_char *buf = xmalloc(bytes);
Ben Lindstromeb648a72001-03-05 06:00:29 +00002296 MD5_CTX md;
2297
Damien Miller996acd22003-04-09 20:59:48 +10002298 logit("do_connection: generating a fake encryption key");
Ben Lindstromeb648a72001-03-05 06:00:29 +00002299 BN_bn2bin(session_key_int, buf);
2300 MD5_Init(&md);
2301 MD5_Update(&md, buf, bytes);
2302 MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
2303 MD5_Final(session_key, &md);
2304 MD5_Init(&md);
2305 MD5_Update(&md, session_key, 16);
2306 MD5_Update(&md, buf, bytes);
2307 MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH);
2308 MD5_Final(session_key + 16, &md);
2309 memset(buf, 0, bytes);
Darren Tuckera627d422013-06-02 07:31:17 +10002310 free(buf);
Ben Lindstrom941ac822001-03-05 06:25:23 +00002311 for (i = 0; i < 16; i++)
2312 session_id[i] = session_key[i] ^ session_key[i + 16];
Damien Miller7650bc62001-01-30 09:27:26 +11002313 }
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002314 /* Destroy the private and public keys. No longer. */
Damien Miller3a5b0232002-03-13 13:19:42 +11002315 destroy_sensitive_data();
Ben Lindstromeb648a72001-03-05 06:00:29 +00002316
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002317 if (use_privsep)
2318 mm_ssh1_session_id(session_id);
2319
Damien Miller396691a2000-01-20 22:44:08 +11002320 /* Destroy the decrypted integer. It is no longer needed. */
2321 BN_clear_free(session_key_int);
2322
Damien Miller95def091999-11-25 00:26:21 +11002323 /* Set the session key. From this on all communications will be encrypted. */
2324 packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002325
Damien Miller95def091999-11-25 00:26:21 +11002326 /* Destroy our copy of the session key. It is no longer needed. */
2327 memset(session_key, 0, sizeof(session_key));
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002328
Damien Miller95def091999-11-25 00:26:21 +11002329 debug("Received session key; encryption turned on.");
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002330
Ben Lindstromf666fec2002-06-06 19:51:58 +00002331 /* Send an acknowledgment packet. Note that this packet is sent encrypted. */
Damien Miller95def091999-11-25 00:26:21 +11002332 packet_start(SSH_SMSG_SUCCESS);
2333 packet_send();
2334 packet_write_wait();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10002335}
Damien Millerefb4afe2000-04-12 18:45:05 +10002336
2337/*
2338 * SSH2 key exchange: diffie-hellman-group1-sha1
2339 */
Ben Lindstrombba81212001-06-25 05:01:22 +00002340static void
Ben Lindstrom46c16222000-12-22 01:43:59 +00002341do_ssh2_kex(void)
Damien Millerefb4afe2000-04-12 18:45:05 +10002342{
Damien Millerefb4afe2000-04-12 18:45:05 +10002343 Kex *kex;
Damien Millerefb4afe2000-04-12 18:45:05 +10002344
Damien Miller78928792000-04-12 20:17:38 +10002345 if (options.ciphers != NULL) {
Damien Miller4af51302000-04-16 11:18:38 +10002346 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
Damien Miller78928792000-04-12 20:17:38 +10002347 myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers;
2348 }
Damien Millera0ff4662001-03-30 10:49:35 +10002349 myproposal[PROPOSAL_ENC_ALGS_CTOS] =
2350 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]);
2351 myproposal[PROPOSAL_ENC_ALGS_STOC] =
2352 compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]);
2353
Ben Lindstrom06b33aa2001-02-15 03:01:59 +00002354 if (options.macs != NULL) {
2355 myproposal[PROPOSAL_MAC_ALGS_CTOS] =
2356 myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs;
2357 }
Damien Miller9786e6e2005-07-26 21:54:56 +10002358 if (options.compression == COMP_NONE) {
Ben Lindstrom23e0f662002-06-21 01:09:47 +00002359 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
2360 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none";
Damien Miller9786e6e2005-07-26 21:54:56 +10002361 } else if (options.compression == COMP_DELAYED) {
2362 myproposal[PROPOSAL_COMP_ALGS_CTOS] =
2363 myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com";
Ben Lindstrom23e0f662002-06-21 01:09:47 +00002364 }
Damien Millerd5f62bf2010-09-24 22:11:14 +10002365 if (options.kex_algorithms != NULL)
2366 myproposal[PROPOSAL_KEX_ALGS] = options.kex_algorithms;
Damien Millerf0b15df2006-03-26 13:59:20 +11002367
Darren Tucker5f96f3b2013-05-16 20:29:28 +10002368 if (options.rekey_limit || options.rekey_interval)
2369 packet_set_rekey_limits((u_int32_t)options.rekey_limit,
2370 (time_t)options.rekey_interval);
2371
Damien Miller0bc1bd82000-11-13 22:57:25 +11002372 myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types();
2373
Ben Lindstrom8ac91062001-04-04 17:57:54 +00002374 /* start key exchange */
Ben Lindstrom238abf62001-04-04 17:52:53 +00002375 kex = kex_setup(myproposal);
Damien Miller8e7fb332003-02-24 12:03:03 +11002376 kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server;
Damien Millerf675fc42004-06-15 10:30:09 +10002377 kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server;
Damien Miller8e7fb332003-02-24 12:03:03 +11002378 kex->kex[KEX_DH_GEX_SHA1] = kexgex_server;
Damien Millera63128d2006-03-15 12:08:28 +11002379 kex->kex[KEX_DH_GEX_SHA256] = kexgex_server;
Damien Millereb8b60e2010-08-31 22:41:14 +10002380 kex->kex[KEX_ECDH_SHA2] = kexecdh_server;
Ben Lindstrom20d7c7b2001-04-04 01:56:17 +00002381 kex->server = 1;
2382 kex->client_version_string=client_version_string;
2383 kex->server_version_string=server_version_string;
Damien Miller0a80ca12010-02-27 07:55:05 +11002384 kex->load_host_public_key=&get_hostkey_public_by_type;
2385 kex->load_host_private_key=&get_hostkey_private_by_type;
Ben Lindstrom7a2073c2002-03-22 02:30:41 +00002386 kex->host_key_index=&get_hostkey_index;
Damien Millerefb4afe2000-04-12 18:45:05 +10002387
Ben Lindstrom8ac91062001-04-04 17:57:54 +00002388 xxx_kex = kex;
2389
Ben Lindstrombe2cc432001-04-04 23:46:07 +00002390 dispatch_run(DISPATCH_BLOCK, &kex->done, kex);
Damien Miller874d77b2000-10-14 16:23:11 +11002391
Ben Lindstrom2d90e002001-04-04 02:00:54 +00002392 session_id2 = kex->session_id;
2393 session_id2_len = kex->session_id_len;
2394
Damien Miller874d77b2000-10-14 16:23:11 +11002395#ifdef DEBUG_KEXDH
2396 /* send 1st encrypted/maced/compressed message */
2397 packet_start(SSH2_MSG_IGNORE);
2398 packet_put_cstring("markus");
2399 packet_send();
2400 packet_write_wait();
2401#endif
Ben Lindstrom20d7c7b2001-04-04 01:56:17 +00002402 debug("KEX done");
Damien Millerefb4afe2000-04-12 18:45:05 +10002403}
Darren Tucker3e33cec2003-10-02 16:12:36 +10002404
2405/* server specific fatal cleanup */
2406void
2407cleanup_exit(int i)
2408{
Damien Miller9ee2c602011-09-22 21:38:30 +10002409 if (the_authctxt) {
Darren Tucker3e33cec2003-10-02 16:12:36 +10002410 do_cleanup(the_authctxt);
Darren Tuckeraf1a60e2011-10-02 18:59:59 +11002411 if (use_privsep && privsep_is_preauth && pmonitor->m_pid > 1) {
Damien Miller9ee2c602011-09-22 21:38:30 +10002412 debug("Killing privsep child %d", pmonitor->m_pid);
2413 if (kill(pmonitor->m_pid, SIGKILL) != 0 &&
Darren Tucker2e135602011-10-02 19:10:13 +11002414 errno != ESRCH)
Damien Miller9ee2c602011-09-22 21:38:30 +10002415 error("%s: kill(%d): %s", __func__,
2416 pmonitor->m_pid, strerror(errno));
2417 }
2418 }
Darren Tucker2e0cf0d2005-02-08 21:52:47 +11002419#ifdef SSH_AUDIT_EVENTS
Darren Tucker269a1ea2005-02-03 00:20:53 +11002420 /* done after do_cleanup so it can cancel the PAM auth 'thread' */
2421 if (!use_privsep || mm_is_monitor())
Darren Tucker2e0cf0d2005-02-08 21:52:47 +11002422 audit_event(SSH_CONNECTION_ABANDON);
Darren Tucker269a1ea2005-02-03 00:20:53 +11002423#endif
Darren Tucker3e33cec2003-10-02 16:12:36 +10002424 _exit(i);
2425}