Darren Tucker | d7bdc0c | 2008-07-02 22:34:30 +1000 | [diff] [blame] | 1 | /* $OpenBSD: sshd.c,v 1.363 2008/07/01 07:24:22 dtucker Exp $ */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 3 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
| 4 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
| 5 | * All rights reserved |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 6 | * This program is the ssh daemon. It listens for connections from clients, |
| 7 | * and performs authentication, executes use commands or shell, and forwards |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 8 | * information to/from the application to the user client over an encrypted |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 9 | * connection. This can also handle forwarding of X11, TCP/IP, and |
| 10 | * authentication agent connections. |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 11 | * |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 12 | * 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 Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 19 | * Privilege Separation: |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 20 | * |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 21 | * Copyright (c) 2000, 2001, 2002 Markus Friedl. All rights reserved. |
| 22 | * Copyright (c) 2002 Niels Provos. All rights reserved. |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 23 | * |
| 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 Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 43 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 44 | |
| 45 | #include "includes.h" |
Damien Miller | 17e91c0 | 2006-03-15 11:28:34 +1100 | [diff] [blame] | 46 | |
Damien Miller | 9cf6d07 | 2006-03-15 11:29:24 +1100 | [diff] [blame] | 47 | #include <sys/types.h> |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 48 | #include <sys/ioctl.h> |
| 49 | #include <sys/socket.h> |
Damien Miller | f17883e | 2006-03-15 11:45:54 +1100 | [diff] [blame] | 50 | #ifdef HAVE_SYS_STAT_H |
| 51 | # include <sys/stat.h> |
| 52 | #endif |
Damien Miller | 9aec919 | 2006-08-05 10:57:45 +1000 | [diff] [blame] | 53 | #ifdef HAVE_SYS_TIME_H |
| 54 | # include <sys/time.h> |
| 55 | #endif |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 56 | #include "openbsd-compat/sys-tree.h" |
Damien Miller | b84886b | 2008-05-19 15:05:07 +1000 | [diff] [blame] | 57 | #include "openbsd-compat/sys-queue.h" |
Damien Miller | 9cf6d07 | 2006-03-15 11:29:24 +1100 | [diff] [blame] | 58 | #include <sys/wait.h> |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 59 | |
Darren Tucker | 3997249 | 2006-07-12 22:22:46 +1000 | [diff] [blame] | 60 | #include <errno.h> |
Damien Miller | 57cf638 | 2006-07-10 21:13:46 +1000 | [diff] [blame] | 61 | #include <fcntl.h> |
Damien Miller | b8fe89c | 2006-07-24 14:51:00 +1000 | [diff] [blame] | 62 | #include <netdb.h> |
Damien Miller | 6645e7a | 2006-03-15 14:42:54 +1100 | [diff] [blame] | 63 | #ifdef HAVE_PATHS_H |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 64 | #include <paths.h> |
Damien Miller | 6645e7a | 2006-03-15 14:42:54 +1100 | [diff] [blame] | 65 | #endif |
Damien Miller | a1738e4 | 2006-07-10 21:33:04 +1000 | [diff] [blame] | 66 | #include <grp.h> |
Damien Miller | 9f2abc4 | 2006-07-10 20:53:08 +1000 | [diff] [blame] | 67 | #include <pwd.h> |
Damien Miller | 6ff3cad | 2006-03-15 11:52:09 +1100 | [diff] [blame] | 68 | #include <signal.h> |
Damien Miller | ded319c | 2006-09-01 15:38:36 +1000 | [diff] [blame] | 69 | #include <stdarg.h> |
Damien Miller | a7a73ee | 2006-08-05 11:37:59 +1000 | [diff] [blame] | 70 | #include <stdio.h> |
Damien Miller | e7a1e5c | 2006-08-05 11:34:19 +1000 | [diff] [blame] | 71 | #include <stdlib.h> |
Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 72 | #include <string.h> |
Damien Miller | 75bb664 | 2006-08-05 14:07:20 +1000 | [diff] [blame] | 73 | #include <unistd.h> |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 74 | |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 75 | #include <openssl/dh.h> |
| 76 | #include <openssl/bn.h> |
Damien Miller | 6a47f30 | 2002-02-13 13:55:06 +1100 | [diff] [blame] | 77 | #include <openssl/md5.h> |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 78 | #include <openssl/rand.h> |
Darren Tucker | bfaaf96 | 2008-02-28 19:13:52 +1100 | [diff] [blame] | 79 | #include "openbsd-compat/openssl-compat.h" |
| 80 | |
Kevin Steves | 0ea1d9d | 2002-04-25 18:17:04 +0000 | [diff] [blame] | 81 | #ifdef HAVE_SECUREWARE |
| 82 | #include <sys/security.h> |
| 83 | #include <prot.h> |
| 84 | #endif |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 85 | |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 86 | #include "xmalloc.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 87 | #include "ssh.h" |
| 88 | #include "ssh1.h" |
| 89 | #include "ssh2.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 90 | #include "rsa.h" |
Ben Lindstrom | d95c09c | 2001-02-18 19:13:33 +0000 | [diff] [blame] | 91 | #include "sshpty.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 92 | #include "packet.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 93 | #include "log.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 94 | #include "buffer.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 95 | #include "servconf.h" |
| 96 | #include "uidswap.h" |
| 97 | #include "compat.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 98 | #include "cipher.h" |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 99 | #include "key.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 100 | #include "kex.h" |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 101 | #include "dh.h" |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 102 | #include "myproposal.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 103 | #include "authfile.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 104 | #include "pathnames.h" |
| 105 | #include "atomicio.h" |
| 106 | #include "canohost.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 107 | #include "hostfile.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 108 | #include "auth.h" |
| 109 | #include "misc.h" |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 110 | #include "msg.h" |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 111 | #include "dispatch.h" |
Ben Lindstrom | 1bae404 | 2001-10-03 17:46:39 +0000 | [diff] [blame] | 112 | #include "channels.h" |
Ben Lindstrom | 73ab9ba | 2002-03-22 01:27:35 +0000 | [diff] [blame] | 113 | #include "session.h" |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 114 | #include "monitor_mm.h" |
| 115 | #include "monitor.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 116 | #ifdef GSSAPI |
| 117 | #include "ssh-gss.h" |
| 118 | #endif |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 119 | #include "monitor_wrap.h" |
| 120 | #include "monitor_fdpass.h" |
Damien Miller | b757677 | 2006-07-10 20:23:39 +1000 | [diff] [blame] | 121 | #include "version.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 122 | |
| 123 | #ifdef LIBWRAP |
| 124 | #include <tcpd.h> |
| 125 | #include <syslog.h> |
Darren Tucker | 1f1e17b | 2008-02-28 23:20:48 +1100 | [diff] [blame] | 126 | int allow_severity; |
| 127 | int deny_severity; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 128 | #endif /* LIBWRAP */ |
| 129 | |
| 130 | #ifndef O_NOCTTY |
| 131 | #define O_NOCTTY 0 |
| 132 | #endif |
| 133 | |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 134 | /* Re-exec fds */ |
| 135 | #define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1) |
| 136 | #define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2) |
| 137 | #define REEXEC_CONFIG_PASS_FD (STDERR_FILENO + 3) |
| 138 | #define REEXEC_MIN_FREE_FD (STDERR_FILENO + 4) |
| 139 | |
Ben Lindstrom | 49a79c0 | 2000-11-17 03:47:20 +0000 | [diff] [blame] | 140 | extern char *__progname; |
Ben Lindstrom | 49a79c0 | 2000-11-17 03:47:20 +0000 | [diff] [blame] | 141 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 142 | /* Server configuration options. */ |
| 143 | ServerOptions options; |
| 144 | |
| 145 | /* Name of the server configuration file. */ |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 146 | char *config_file_name = _PATH_SERVER_CONFIG_FILE; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 147 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 148 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 149 | * Debug mode flag. This can be set on the command line. If debug |
| 150 | * mode is enabled, extra debugging output will be sent to the system |
| 151 | * log, the daemon will not go to background, and will exit after processing |
| 152 | * the first connection. |
| 153 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 154 | int debug_flag = 0; |
| 155 | |
Ben Lindstrom | 794325a | 2001-08-06 21:09:07 +0000 | [diff] [blame] | 156 | /* Flag indicating that the daemon should only test the configuration and keys. */ |
| 157 | int test_flag = 0; |
| 158 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 159 | /* Flag indicating that the daemon is being started from inetd. */ |
| 160 | int inetd_flag = 0; |
| 161 | |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 162 | /* Flag indicating that sshd should not detach and become a daemon. */ |
| 163 | int no_daemon_flag = 0; |
| 164 | |
Damien Miller | 5ce662a | 1999-11-11 17:57:39 +1100 | [diff] [blame] | 165 | /* debug goes to stderr unless inetd_flag is set */ |
| 166 | int log_stderr = 0; |
| 167 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 168 | /* Saved arguments to main(). */ |
| 169 | char **saved_argv; |
Damien Miller | b8c656e | 2000-06-28 15:22:41 +1000 | [diff] [blame] | 170 | int saved_argc; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 171 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 172 | /* re-exec */ |
| 173 | int rexeced_flag = 0; |
| 174 | int rexec_flag = 1; |
| 175 | int rexec_argc = 0; |
| 176 | char **rexec_argv; |
| 177 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 178 | /* |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 179 | * The sockets that the server is listening; this is used in the SIGHUP |
| 180 | * signal handler. |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 181 | */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 182 | #define MAX_LISTEN_SOCKS 16 |
| 183 | int listen_socks[MAX_LISTEN_SOCKS]; |
| 184 | int num_listen_socks = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 185 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 186 | /* |
| 187 | * the client's version string, passed by sshd2 in compat mode. if != NULL, |
| 188 | * sshd will skip the version-number exchange |
| 189 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 190 | char *client_version_string = NULL; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 191 | char *server_version_string = NULL; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 192 | |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 193 | /* for rekeying XXX fixme */ |
| 194 | Kex *xxx_kex; |
| 195 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 196 | /* |
| 197 | * Any really sensitive data in the application is contained in this |
| 198 | * structure. The idea is that this structure could be locked into memory so |
| 199 | * that the pages do not get written into swap. However, there are some |
| 200 | * problems. The private key contains BIGNUMs, and we do not (in principle) |
| 201 | * have access to the internals of them, and locking just the structure is |
| 202 | * not very useful. Currently, memory locking is not implemented. |
| 203 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 204 | struct { |
Ben Lindstrom | ca42d5f | 2001-03-09 18:25:32 +0000 | [diff] [blame] | 205 | Key *server_key; /* ephemeral server key */ |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 206 | Key *ssh1_host_key; /* ssh1 host key */ |
| 207 | Key **host_keys; /* all private host keys */ |
| 208 | int have_ssh1_key; |
| 209 | int have_ssh2_key; |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 210 | u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 211 | } sensitive_data; |
| 212 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 213 | /* |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 214 | * Flag indicating whether the RSA server key needs to be regenerated. |
| 215 | * Is set in the SIGALRM handler and cleared when the key is regenerated. |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 216 | */ |
Ben Lindstrom | 5e71c54 | 2001-12-06 16:48:14 +0000 | [diff] [blame] | 217 | static volatile sig_atomic_t key_do_regen = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 218 | |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 219 | /* This is set to true when a signal is received. */ |
Ben Lindstrom | 5e71c54 | 2001-12-06 16:48:14 +0000 | [diff] [blame] | 220 | static volatile sig_atomic_t received_sighup = 0; |
| 221 | static volatile sig_atomic_t received_sigterm = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 222 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 223 | /* session identifier, used by RSA-auth */ |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 224 | u_char session_id[16]; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 225 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 226 | /* same for ssh2 */ |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 227 | u_char *session_id2 = NULL; |
Darren Tucker | 502d384 | 2003-06-28 12:38:01 +1000 | [diff] [blame] | 228 | u_int session_id2_len = 0; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 229 | |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 230 | /* record remote hostname or ip */ |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 231 | u_int utmp_len = MAXHOSTNAMELEN; |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 232 | |
Ben Lindstrom | d84df98 | 2001-12-06 16:35:40 +0000 | [diff] [blame] | 233 | /* options.max_startup sized array of fd ints */ |
| 234 | int *startup_pipes = NULL; |
| 235 | int startup_pipe; /* in child */ |
| 236 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 237 | /* variables used for privilege separation */ |
Darren Tucker | 4515047 | 2006-07-12 22:34:17 +1000 | [diff] [blame] | 238 | int use_privsep = -1; |
Darren Tucker | a8be9e2 | 2004-02-06 16:40:27 +1100 | [diff] [blame] | 239 | struct monitor *pmonitor = NULL; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 240 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 241 | /* global authentication context */ |
| 242 | Authctxt *the_authctxt = NULL; |
| 243 | |
Darren Tucker | 4515047 | 2006-07-12 22:34:17 +1000 | [diff] [blame] | 244 | /* sshd_config buffer */ |
| 245 | Buffer cfg; |
| 246 | |
Darren Tucker | 0999174 | 2004-07-17 17:05:14 +1000 | [diff] [blame] | 247 | /* message to be displayed after login */ |
| 248 | Buffer loginmsg; |
| 249 | |
Damien Miller | 6433df0 | 2006-09-07 10:36:43 +1000 | [diff] [blame] | 250 | /* Unprivileged user */ |
| 251 | struct passwd *privsep_pw = NULL; |
| 252 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 253 | /* Prototypes for various functions defined later in this file. */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 254 | void destroy_sensitive_data(void); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 255 | void demote_sensitive_data(void); |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 256 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 257 | static void do_ssh1_kex(void); |
| 258 | static void do_ssh2_kex(void); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 259 | |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 260 | /* |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 261 | * Close all listening sockets |
| 262 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 263 | static void |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 264 | close_listen_socks(void) |
| 265 | { |
| 266 | int i; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 267 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 268 | for (i = 0; i < num_listen_socks; i++) |
| 269 | close(listen_socks[i]); |
| 270 | num_listen_socks = -1; |
| 271 | } |
| 272 | |
Ben Lindstrom | d84df98 | 2001-12-06 16:35:40 +0000 | [diff] [blame] | 273 | static void |
| 274 | close_startup_pipes(void) |
| 275 | { |
| 276 | int i; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 277 | |
Ben Lindstrom | d84df98 | 2001-12-06 16:35:40 +0000 | [diff] [blame] | 278 | if (startup_pipes) |
| 279 | for (i = 0; i < options.max_startups; i++) |
| 280 | if (startup_pipes[i] != -1) |
| 281 | close(startup_pipes[i]); |
| 282 | } |
| 283 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 284 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 285 | * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP; |
| 286 | * the effect is to reread the configuration file (and to regenerate |
| 287 | * the server key). |
| 288 | */ |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 289 | |
| 290 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 291 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 292 | sighup_handler(int sig) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 293 | { |
Ben Lindstrom | 0795848 | 2001-12-06 16:19:01 +0000 | [diff] [blame] | 294 | int save_errno = errno; |
| 295 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 296 | received_sighup = 1; |
| 297 | signal(SIGHUP, sighup_handler); |
Ben Lindstrom | 0795848 | 2001-12-06 16:19:01 +0000 | [diff] [blame] | 298 | errno = save_errno; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 299 | } |
| 300 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 301 | /* |
| 302 | * Called from the main program after receiving SIGHUP. |
| 303 | * Restarts the server. |
| 304 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 305 | static void |
Ben Lindstrom | 31ca54a | 2001-02-09 02:11:24 +0000 | [diff] [blame] | 306 | sighup_restart(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 307 | { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 308 | logit("Received SIGHUP; restarting."); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 309 | close_listen_socks(); |
Ben Lindstrom | d84df98 | 2001-12-06 16:35:40 +0000 | [diff] [blame] | 310 | close_startup_pipes(); |
Darren Tucker | ed62396 | 2007-02-25 20:37:21 +1100 | [diff] [blame] | 311 | alarm(0); /* alarm timer persists across exec */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 312 | execv(saved_argv[0], saved_argv); |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 313 | logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0], |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 314 | strerror(errno)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 315 | exit(1); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 316 | } |
| 317 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 318 | /* |
| 319 | * Generic signal handler for terminating signals in the master daemon. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 320 | */ |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 321 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 322 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 323 | sigterm_handler(int sig) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 324 | { |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 325 | received_sigterm = sig; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 326 | } |
| 327 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 328 | /* |
| 329 | * SIGCHLD handler. This is called whenever a child dies. This will then |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 330 | * reap any zombies left by exited children. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 331 | */ |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 332 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 333 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 334 | main_sigchld_handler(int sig) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 335 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 336 | int save_errno = errno; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 337 | pid_t pid; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 338 | int status; |
Damien Miller | 431f66b | 1999-11-21 18:31:57 +1100 | [diff] [blame] | 339 | |
Ben Lindstrom | 47fd811 | 2002-04-02 20:48:19 +0000 | [diff] [blame] | 340 | while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || |
| 341 | (pid < 0 && errno == EINTR)) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 342 | ; |
Damien Miller | 431f66b | 1999-11-21 18:31:57 +1100 | [diff] [blame] | 343 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 344 | signal(SIGCHLD, main_sigchld_handler); |
| 345 | errno = save_errno; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 346 | } |
| 347 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 348 | /* |
| 349 | * Signal handler for the alarm after the login grace period has expired. |
| 350 | */ |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 351 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 352 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 353 | grace_alarm_handler(int sig) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 354 | { |
Darren Tucker | a8be9e2 | 2004-02-06 16:40:27 +1100 | [diff] [blame] | 355 | if (use_privsep && pmonitor != NULL && pmonitor->m_pid > 0) |
| 356 | kill(pmonitor->m_pid, SIGALRM); |
| 357 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 358 | /* Log error and exit. */ |
Damien Miller | 99a648e | 2006-08-19 00:32:20 +1000 | [diff] [blame] | 359 | sigdie("Timeout before authentication for %s", get_remote_ipaddr()); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 360 | } |
| 361 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 362 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 363 | * Signal handler for the key regeneration alarm. Note that this |
| 364 | * alarm only occurs in the daemon waiting for connections, and it does not |
| 365 | * do anything with the private key or random state before forking. |
| 366 | * Thus there should be no concurrency control/asynchronous execution |
| 367 | * problems. |
| 368 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 369 | static void |
Ben Lindstrom | ca42d5f | 2001-03-09 18:25:32 +0000 | [diff] [blame] | 370 | generate_ephemeral_server_key(void) |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 371 | { |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 372 | verbose("Generating %s%d bit RSA key.", |
Damien Miller | ff75ac4 | 2001-03-30 10:50:32 +1000 | [diff] [blame] | 373 | sensitive_data.server_key ? "new " : "", options.server_key_bits); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 374 | if (sensitive_data.server_key != NULL) |
| 375 | key_free(sensitive_data.server_key); |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 376 | sensitive_data.server_key = key_generate(KEY_RSA1, |
Damien Miller | ff75ac4 | 2001-03-30 10:50:32 +1000 | [diff] [blame] | 377 | options.server_key_bits); |
| 378 | verbose("RSA key generation complete."); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 379 | |
Damien Miller | 354c48c | 2008-05-19 14:50:00 +1000 | [diff] [blame] | 380 | arc4random_buf(sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 381 | arc4random_stir(); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 382 | } |
Ben Lindstrom | 2f959b4 | 2001-01-11 06:20:23 +0000 | [diff] [blame] | 383 | |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 384 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 385 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 386 | key_regeneration_alarm(int sig) |
| 387 | { |
| 388 | int save_errno = errno; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 389 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 390 | signal(SIGALRM, SIG_DFL); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 391 | errno = save_errno; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 392 | key_do_regen = 1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 393 | } |
| 394 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 395 | static void |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 396 | sshd_exchange_identification(int sock_in, int sock_out) |
| 397 | { |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 398 | u_int i; |
| 399 | int mismatch; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 400 | int remote_major, remote_minor; |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 401 | int major, minor; |
Darren Tucker | d7bdc0c | 2008-07-02 22:34:30 +1000 | [diff] [blame] | 402 | char *s, *newline = "\n"; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 403 | char buf[256]; /* Must not be larger than remote_version. */ |
| 404 | char remote_version[256]; /* Must be at least as big as buf. */ |
| 405 | |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 406 | if ((options.protocol & SSH_PROTO_1) && |
| 407 | (options.protocol & SSH_PROTO_2)) { |
| 408 | major = PROTOCOL_MAJOR_1; |
| 409 | minor = 99; |
| 410 | } else if (options.protocol & SSH_PROTO_2) { |
| 411 | major = PROTOCOL_MAJOR_2; |
| 412 | minor = PROTOCOL_MINOR_2; |
Darren Tucker | d7bdc0c | 2008-07-02 22:34:30 +1000 | [diff] [blame] | 413 | newline = "\r\n"; |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 414 | } else { |
| 415 | major = PROTOCOL_MAJOR_1; |
| 416 | minor = PROTOCOL_MINOR_1; |
| 417 | } |
Darren Tucker | d7bdc0c | 2008-07-02 22:34:30 +1000 | [diff] [blame] | 418 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s%s", major, minor, |
| 419 | SSH_VERSION, newline); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 420 | server_version_string = xstrdup(buf); |
| 421 | |
Darren Tucker | fe0078a | 2003-07-19 19:52:28 +1000 | [diff] [blame] | 422 | /* Send our protocol version identification. */ |
| 423 | if (atomicio(vwrite, sock_out, server_version_string, |
| 424 | strlen(server_version_string)) |
| 425 | != strlen(server_version_string)) { |
| 426 | logit("Could not write ident string to %s", get_remote_ipaddr()); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 427 | cleanup_exit(255); |
Darren Tucker | fe0078a | 2003-07-19 19:52:28 +1000 | [diff] [blame] | 428 | } |
| 429 | |
| 430 | /* Read other sides version identification. */ |
| 431 | memset(buf, 0, sizeof(buf)); |
| 432 | for (i = 0; i < sizeof(buf) - 1; i++) { |
| 433 | if (atomicio(read, sock_in, &buf[i], 1) != 1) { |
| 434 | logit("Did not receive identification string from %s", |
| 435 | get_remote_ipaddr()); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 436 | cleanup_exit(255); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 437 | } |
Darren Tucker | fe0078a | 2003-07-19 19:52:28 +1000 | [diff] [blame] | 438 | if (buf[i] == '\r') { |
| 439 | buf[i] = 0; |
| 440 | /* Kludge for F-Secure Macintosh < 1.0.2 */ |
| 441 | if (i == 12 && |
| 442 | strncmp(buf, "SSH-1.5-W1.0", 12) == 0) |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 443 | break; |
Darren Tucker | fe0078a | 2003-07-19 19:52:28 +1000 | [diff] [blame] | 444 | continue; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 445 | } |
Darren Tucker | fe0078a | 2003-07-19 19:52:28 +1000 | [diff] [blame] | 446 | if (buf[i] == '\n') { |
| 447 | buf[i] = 0; |
| 448 | break; |
| 449 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 450 | } |
Darren Tucker | fe0078a | 2003-07-19 19:52:28 +1000 | [diff] [blame] | 451 | buf[sizeof(buf) - 1] = 0; |
| 452 | client_version_string = xstrdup(buf); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 453 | |
| 454 | /* |
| 455 | * Check that the versions match. In future this might accept |
| 456 | * several versions and set appropriate flags to handle them. |
| 457 | */ |
| 458 | if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n", |
| 459 | &remote_major, &remote_minor, remote_version) != 3) { |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 460 | s = "Protocol mismatch.\n"; |
Darren Tucker | 9f63f22 | 2003-07-03 13:46:56 +1000 | [diff] [blame] | 461 | (void) atomicio(vwrite, sock_out, s, strlen(s)); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 462 | close(sock_in); |
| 463 | close(sock_out); |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 464 | logit("Bad protocol version identification '%.100s' from %s", |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 465 | client_version_string, get_remote_ipaddr()); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 466 | cleanup_exit(255); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 467 | } |
| 468 | debug("Client protocol version %d.%d; client software version %.100s", |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 469 | remote_major, remote_minor, remote_version); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 470 | |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 471 | compat_datafellows(remote_version); |
| 472 | |
Damien Miller | e926497 | 2002-09-30 11:59:21 +1000 | [diff] [blame] | 473 | if (datafellows & SSH_BUG_PROBE) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 474 | logit("probed from %s with %s. Don't panic.", |
Damien Miller | e926497 | 2002-09-30 11:59:21 +1000 | [diff] [blame] | 475 | get_remote_ipaddr(), client_version_string); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 476 | cleanup_exit(255); |
Damien Miller | e926497 | 2002-09-30 11:59:21 +1000 | [diff] [blame] | 477 | } |
| 478 | |
Damien Miller | 27dbe6f | 2001-03-19 22:36:20 +1100 | [diff] [blame] | 479 | if (datafellows & SSH_BUG_SCANNER) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 480 | logit("scanned from %s with %s. Don't panic.", |
Damien Miller | 27dbe6f | 2001-03-19 22:36:20 +1100 | [diff] [blame] | 481 | get_remote_ipaddr(), client_version_string); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 482 | cleanup_exit(255); |
Damien Miller | 27dbe6f | 2001-03-19 22:36:20 +1100 | [diff] [blame] | 483 | } |
| 484 | |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 485 | mismatch = 0; |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 486 | switch (remote_major) { |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 487 | case 1: |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 488 | if (remote_minor == 99) { |
| 489 | if (options.protocol & SSH_PROTO_2) |
| 490 | enable_compat20(); |
| 491 | else |
| 492 | mismatch = 1; |
| 493 | break; |
| 494 | } |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 495 | if (!(options.protocol & SSH_PROTO_1)) { |
| 496 | mismatch = 1; |
| 497 | break; |
| 498 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 499 | if (remote_minor < 3) { |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 500 | packet_disconnect("Your ssh version is too old and " |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 501 | "is no longer supported. Please install a newer version."); |
| 502 | } else if (remote_minor == 3) { |
| 503 | /* note that this disables agent-forwarding */ |
| 504 | enable_compat13(); |
| 505 | } |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 506 | break; |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 507 | case 2: |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 508 | if (options.protocol & SSH_PROTO_2) { |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 509 | enable_compat20(); |
| 510 | break; |
| 511 | } |
| 512 | /* FALLTHROUGH */ |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 513 | default: |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 514 | mismatch = 1; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 515 | break; |
| 516 | } |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 517 | chop(server_version_string); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 518 | debug("Local version string %.200s", server_version_string); |
| 519 | |
| 520 | if (mismatch) { |
| 521 | s = "Protocol major versions differ.\n"; |
Darren Tucker | 9f63f22 | 2003-07-03 13:46:56 +1000 | [diff] [blame] | 522 | (void) atomicio(vwrite, sock_out, s, strlen(s)); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 523 | close(sock_in); |
| 524 | close(sock_out); |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 525 | logit("Protocol major versions differ for %s: %.200s vs. %.200s", |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 526 | get_remote_ipaddr(), |
| 527 | server_version_string, client_version_string); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 528 | cleanup_exit(255); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 529 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 530 | } |
| 531 | |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 532 | /* Destroy the host and server keys. They will no longer be needed. */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 533 | void |
| 534 | destroy_sensitive_data(void) |
| 535 | { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 536 | int i; |
| 537 | |
| 538 | if (sensitive_data.server_key) { |
| 539 | key_free(sensitive_data.server_key); |
| 540 | sensitive_data.server_key = NULL; |
| 541 | } |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 542 | for (i = 0; i < options.num_host_key_files; i++) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 543 | if (sensitive_data.host_keys[i]) { |
| 544 | key_free(sensitive_data.host_keys[i]); |
| 545 | sensitive_data.host_keys[i] = NULL; |
| 546 | } |
| 547 | } |
| 548 | sensitive_data.ssh1_host_key = NULL; |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 549 | memset(sensitive_data.ssh1_cookie, 0, SSH_SESSION_KEY_LENGTH); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 550 | } |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 551 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 552 | /* Demote private to public keys for network child */ |
| 553 | void |
| 554 | demote_sensitive_data(void) |
| 555 | { |
| 556 | Key *tmp; |
| 557 | int i; |
| 558 | |
| 559 | if (sensitive_data.server_key) { |
| 560 | tmp = key_demote(sensitive_data.server_key); |
| 561 | key_free(sensitive_data.server_key); |
| 562 | sensitive_data.server_key = tmp; |
| 563 | } |
| 564 | |
| 565 | for (i = 0; i < options.num_host_key_files; i++) { |
| 566 | if (sensitive_data.host_keys[i]) { |
| 567 | tmp = key_demote(sensitive_data.host_keys[i]); |
| 568 | key_free(sensitive_data.host_keys[i]); |
| 569 | sensitive_data.host_keys[i] = tmp; |
| 570 | if (tmp->type == KEY_RSA1) |
| 571 | sensitive_data.ssh1_host_key = tmp; |
| 572 | } |
| 573 | } |
| 574 | |
| 575 | /* We do not clear ssh1_host key and cookie. XXX - Okay Niels? */ |
| 576 | } |
| 577 | |
Ben Lindstrom | 0810519 | 2002-03-22 02:50:06 +0000 | [diff] [blame] | 578 | static void |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 579 | privsep_preauth_child(void) |
| 580 | { |
Damien Miller | 354c48c | 2008-05-19 14:50:00 +1000 | [diff] [blame] | 581 | u_int32_t rnd[256]; |
Ben Lindstrom | 810af96 | 2002-07-04 00:11:40 +0000 | [diff] [blame] | 582 | gid_t gidset[1]; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 583 | |
| 584 | /* Enable challenge-response authentication for privilege separation */ |
| 585 | privsep_challenge_enable(); |
| 586 | |
Damien Miller | 76e95da | 2008-03-07 18:31:24 +1100 | [diff] [blame] | 587 | arc4random_stir(); |
Damien Miller | 354c48c | 2008-05-19 14:50:00 +1000 | [diff] [blame] | 588 | arc4random_buf(rnd, sizeof(rnd)); |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 589 | RAND_seed(rnd, sizeof(rnd)); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 590 | |
| 591 | /* Demote the private keys to public keys. */ |
| 592 | demote_sensitive_data(); |
| 593 | |
Ben Lindstrom | a962c2f | 2002-07-04 00:14:17 +0000 | [diff] [blame] | 594 | /* Change our root directory */ |
Ben Lindstrom | 7a7edf7 | 2002-03-22 02:42:37 +0000 | [diff] [blame] | 595 | if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1) |
| 596 | fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR, |
| 597 | strerror(errno)); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 598 | if (chdir("/") == -1) |
Ben Lindstrom | 1ee9ec3 | 2002-03-22 03:14:45 +0000 | [diff] [blame] | 599 | fatal("chdir(\"/\"): %s", strerror(errno)); |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 600 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 601 | /* Drop our privileges */ |
Damien Miller | 6433df0 | 2006-09-07 10:36:43 +1000 | [diff] [blame] | 602 | debug3("privsep user:group %u:%u", (u_int)privsep_pw->pw_uid, |
| 603 | (u_int)privsep_pw->pw_gid); |
Ben Lindstrom | fbcc3f7 | 2002-06-25 23:24:18 +0000 | [diff] [blame] | 604 | #if 0 |
Darren Tucker | d592048 | 2004-02-29 20:11:30 +1100 | [diff] [blame] | 605 | /* XXX not ready, too heavy after chroot */ |
Damien Miller | 6433df0 | 2006-09-07 10:36:43 +1000 | [diff] [blame] | 606 | do_setusercontext(privsep_pw); |
Ben Lindstrom | fbcc3f7 | 2002-06-25 23:24:18 +0000 | [diff] [blame] | 607 | #else |
Damien Miller | 6433df0 | 2006-09-07 10:36:43 +1000 | [diff] [blame] | 608 | gidset[0] = privsep_pw->pw_gid; |
Ben Lindstrom | fbcc3f7 | 2002-06-25 23:24:18 +0000 | [diff] [blame] | 609 | if (setgroups(1, gidset) < 0) |
| 610 | fatal("setgroups: %.100s", strerror(errno)); |
Damien Miller | 6433df0 | 2006-09-07 10:36:43 +1000 | [diff] [blame] | 611 | permanently_set_uid(privsep_pw); |
Ben Lindstrom | fbcc3f7 | 2002-06-25 23:24:18 +0000 | [diff] [blame] | 612 | #endif |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 613 | } |
| 614 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 615 | static int |
| 616 | privsep_preauth(Authctxt *authctxt) |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 617 | { |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 618 | int status; |
| 619 | pid_t pid; |
| 620 | |
| 621 | /* Set up unprivileged child process to deal with network data */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 622 | pmonitor = monitor_init(); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 623 | /* Store a pointer to the kex for later rekeying */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 624 | pmonitor->m_pkex = &xxx_kex; |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 625 | |
| 626 | pid = fork(); |
| 627 | if (pid == -1) { |
| 628 | fatal("fork of unprivileged child failed"); |
| 629 | } else if (pid != 0) { |
Ben Lindstrom | ce0f634 | 2002-06-11 16:42:49 +0000 | [diff] [blame] | 630 | debug2("Network child is on pid %ld", (long)pid); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 631 | |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 632 | close(pmonitor->m_recvfd); |
Darren Tucker | a8be9e2 | 2004-02-06 16:40:27 +1100 | [diff] [blame] | 633 | pmonitor->m_pid = pid; |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 634 | monitor_child_preauth(authctxt, pmonitor); |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 635 | close(pmonitor->m_sendfd); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 636 | |
| 637 | /* Sync memory */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 638 | monitor_sync(pmonitor); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 639 | |
| 640 | /* Wait for the child's exit status */ |
Ben Lindstrom | 47fd811 | 2002-04-02 20:48:19 +0000 | [diff] [blame] | 641 | while (waitpid(pid, &status, 0) < 0) |
| 642 | if (errno != EINTR) |
| 643 | break; |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 644 | return (1); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 645 | } else { |
| 646 | /* child */ |
| 647 | |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 648 | close(pmonitor->m_sendfd); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 649 | |
| 650 | /* Demote the child */ |
| 651 | if (getuid() == 0 || geteuid() == 0) |
| 652 | privsep_preauth_child(); |
Ben Lindstrom | f90f58d | 2002-03-26 01:53:03 +0000 | [diff] [blame] | 653 | setproctitle("%s", "[net]"); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 654 | } |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 655 | return (0); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 656 | } |
| 657 | |
Ben Lindstrom | 0810519 | 2002-03-22 02:50:06 +0000 | [diff] [blame] | 658 | static void |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 659 | privsep_postauth(Authctxt *authctxt) |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 660 | { |
Damien Miller | 76e95da | 2008-03-07 18:31:24 +1100 | [diff] [blame] | 661 | u_int32_t rnd[256]; |
Damien Miller | 76e95da | 2008-03-07 18:31:24 +1100 | [diff] [blame] | 662 | |
Tim Rice | 9dd3081 | 2002-07-07 13:43:36 -0700 | [diff] [blame] | 663 | #ifdef DISABLE_FD_PASSING |
Tim Rice | 8eff319 | 2002-06-25 15:35:15 -0700 | [diff] [blame] | 664 | if (1) { |
| 665 | #else |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 666 | if (authctxt->pw->pw_uid == 0 || options.use_login) { |
Tim Rice | 8eff319 | 2002-06-25 15:35:15 -0700 | [diff] [blame] | 667 | #endif |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 668 | /* File descriptor passing is broken or root login */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 669 | use_privsep = 0; |
Darren Tucker | 45b0142 | 2005-10-03 18:20:00 +1000 | [diff] [blame] | 670 | goto skip; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 671 | } |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 672 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 673 | /* New socket pair */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 674 | monitor_reinit(pmonitor); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 675 | |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 676 | pmonitor->m_pid = fork(); |
| 677 | if (pmonitor->m_pid == -1) |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 678 | fatal("fork of unprivileged child failed"); |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 679 | else if (pmonitor->m_pid != 0) { |
Ben Lindstrom | ce0f634 | 2002-06-11 16:42:49 +0000 | [diff] [blame] | 680 | debug2("User child is on pid %ld", (long)pmonitor->m_pid); |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 681 | close(pmonitor->m_recvfd); |
Darren Tucker | eb57862 | 2004-08-12 23:08:14 +1000 | [diff] [blame] | 682 | buffer_clear(&loginmsg); |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 683 | monitor_child_postauth(pmonitor); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 684 | |
| 685 | /* NEVERREACHED */ |
| 686 | exit(0); |
| 687 | } |
| 688 | |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 689 | close(pmonitor->m_sendfd); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 690 | |
| 691 | /* Demote the private keys to public keys. */ |
| 692 | demote_sensitive_data(); |
| 693 | |
Damien Miller | 76e95da | 2008-03-07 18:31:24 +1100 | [diff] [blame] | 694 | arc4random_stir(); |
Damien Miller | 354c48c | 2008-05-19 14:50:00 +1000 | [diff] [blame] | 695 | arc4random_buf(rnd, sizeof(rnd)); |
Damien Miller | 76e95da | 2008-03-07 18:31:24 +1100 | [diff] [blame] | 696 | RAND_seed(rnd, sizeof(rnd)); |
| 697 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 698 | /* Drop privileges */ |
| 699 | do_setusercontext(authctxt->pw); |
| 700 | |
Darren Tucker | 45b0142 | 2005-10-03 18:20:00 +1000 | [diff] [blame] | 701 | skip: |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 702 | /* It is safe now to apply the key state */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 703 | monitor_apply_keystate(pmonitor); |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 704 | |
| 705 | /* |
| 706 | * Tell the packet layer that authentication was successful, since |
| 707 | * this information is not part of the key state. |
| 708 | */ |
| 709 | packet_set_authenticated(); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 710 | } |
| 711 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 712 | static char * |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 713 | list_hostkey_types(void) |
| 714 | { |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 715 | Buffer b; |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 716 | const char *p; |
| 717 | char *ret; |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 718 | int i; |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 719 | |
| 720 | buffer_init(&b); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 721 | for (i = 0; i < options.num_host_key_files; i++) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 722 | Key *key = sensitive_data.host_keys[i]; |
| 723 | if (key == NULL) |
| 724 | continue; |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 725 | switch (key->type) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 726 | case KEY_RSA: |
| 727 | case KEY_DSA: |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 728 | if (buffer_len(&b) > 0) |
| 729 | buffer_append(&b, ",", 1); |
| 730 | p = key_ssh_name(key); |
| 731 | buffer_append(&b, p, strlen(p)); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 732 | break; |
| 733 | } |
| 734 | } |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 735 | buffer_append(&b, "\0", 1); |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 736 | ret = xstrdup(buffer_ptr(&b)); |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 737 | buffer_free(&b); |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 738 | debug("list_hostkey_types: %s", ret); |
| 739 | return ret; |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 740 | } |
| 741 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 742 | Key * |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 743 | get_hostkey_by_type(int type) |
| 744 | { |
| 745 | int i; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 746 | |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 747 | for (i = 0; i < options.num_host_key_files; i++) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 748 | Key *key = sensitive_data.host_keys[i]; |
| 749 | if (key != NULL && key->type == type) |
| 750 | return key; |
| 751 | } |
| 752 | return NULL; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 753 | } |
| 754 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 755 | Key * |
| 756 | get_hostkey_by_index(int ind) |
| 757 | { |
| 758 | if (ind < 0 || ind >= options.num_host_key_files) |
| 759 | return (NULL); |
| 760 | return (sensitive_data.host_keys[ind]); |
| 761 | } |
| 762 | |
| 763 | int |
| 764 | get_hostkey_index(Key *key) |
| 765 | { |
| 766 | int i; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 767 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 768 | for (i = 0; i < options.num_host_key_files; i++) { |
| 769 | if (key == sensitive_data.host_keys[i]) |
| 770 | return (i); |
| 771 | } |
| 772 | return (-1); |
| 773 | } |
| 774 | |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 775 | /* |
| 776 | * returns 1 if connection should be dropped, 0 otherwise. |
| 777 | * dropping starts at connection #max_startups_begin with a probability |
| 778 | * of (max_startups_rate/100). the probability increases linearly until |
| 779 | * all connections are dropped for startups > max_startups |
| 780 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 781 | static int |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 782 | drop_connection(int startups) |
| 783 | { |
Darren Tucker | 178fa66 | 2004-11-05 20:09:09 +1100 | [diff] [blame] | 784 | int p, r; |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 785 | |
| 786 | if (startups < options.max_startups_begin) |
| 787 | return 0; |
| 788 | if (startups >= options.max_startups) |
| 789 | return 1; |
| 790 | if (options.max_startups_rate == 100) |
| 791 | return 1; |
| 792 | |
| 793 | p = 100 - options.max_startups_rate; |
| 794 | p *= startups - options.max_startups_begin; |
Darren Tucker | 178fa66 | 2004-11-05 20:09:09 +1100 | [diff] [blame] | 795 | p /= options.max_startups - options.max_startups_begin; |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 796 | p += options.max_startups_rate; |
Damien Miller | 354c48c | 2008-05-19 14:50:00 +1000 | [diff] [blame] | 797 | r = arc4random_uniform(100); |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 798 | |
Darren Tucker | 3269b13 | 2004-11-05 20:20:59 +1100 | [diff] [blame] | 799 | debug("drop_connection: p %d, r %d", p, r); |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 800 | return (r < p) ? 1 : 0; |
| 801 | } |
| 802 | |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 803 | static void |
| 804 | usage(void) |
| 805 | { |
Damien Miller | 0c889cd | 2004-03-22 09:36:00 +1100 | [diff] [blame] | 806 | fprintf(stderr, "%s, %s\n", |
Damien Miller | 2aa6d3c | 2004-09-12 16:53:04 +1000 | [diff] [blame] | 807 | SSH_RELEASE, SSLeay_version(SSLEAY_VERSION)); |
Damien Miller | b408786 | 2004-03-22 09:35:21 +1100 | [diff] [blame] | 808 | fprintf(stderr, |
Darren Tucker | e7f3f75 | 2008-06-10 23:06:01 +1000 | [diff] [blame] | 809 | "usage: sshd [-46DdeiqTt] [-b bits] [-C connection_spec] [-f config_file]\n" |
| 810 | " [-g login_grace_time] [-h host_key_file] [-k key_gen_time]\n" |
| 811 | " [-o option] [-p port] [-u len]\n" |
Damien Miller | b408786 | 2004-03-22 09:35:21 +1100 | [diff] [blame] | 812 | ); |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 813 | exit(1); |
| 814 | } |
| 815 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 816 | static void |
| 817 | send_rexec_state(int fd, Buffer *conf) |
| 818 | { |
| 819 | Buffer m; |
| 820 | |
| 821 | debug3("%s: entering fd = %d config len %d", __func__, fd, |
| 822 | buffer_len(conf)); |
| 823 | |
| 824 | /* |
| 825 | * Protocol from reexec master to child: |
| 826 | * string configuration |
| 827 | * u_int ephemeral_key_follows |
| 828 | * bignum e (only if ephemeral_key_follows == 1) |
| 829 | * bignum n " |
| 830 | * bignum d " |
| 831 | * bignum iqmp " |
| 832 | * bignum p " |
| 833 | * bignum q " |
Darren Tucker | c6f8219 | 2005-09-27 22:46:32 +1000 | [diff] [blame] | 834 | * string rngseed (only if OpenSSL is not self-seeded) |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 835 | */ |
| 836 | buffer_init(&m); |
| 837 | buffer_put_cstring(&m, buffer_ptr(conf)); |
| 838 | |
Darren Tucker | fc95970 | 2004-07-17 16:12:08 +1000 | [diff] [blame] | 839 | if (sensitive_data.server_key != NULL && |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 840 | sensitive_data.server_key->type == KEY_RSA1) { |
| 841 | buffer_put_int(&m, 1); |
| 842 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->e); |
| 843 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->n); |
| 844 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->d); |
| 845 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->iqmp); |
| 846 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->p); |
| 847 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->q); |
| 848 | } else |
| 849 | buffer_put_int(&m, 0); |
| 850 | |
Darren Tucker | c6f8219 | 2005-09-27 22:46:32 +1000 | [diff] [blame] | 851 | #ifndef OPENSSL_PRNG_ONLY |
| 852 | rexec_send_rng_seed(&m); |
| 853 | #endif |
| 854 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 855 | if (ssh_msg_send(fd, 0, &m) == -1) |
| 856 | fatal("%s: ssh_msg_send failed", __func__); |
| 857 | |
| 858 | buffer_free(&m); |
| 859 | |
| 860 | debug3("%s: done", __func__); |
| 861 | } |
| 862 | |
| 863 | static void |
| 864 | recv_rexec_state(int fd, Buffer *conf) |
| 865 | { |
| 866 | Buffer m; |
| 867 | char *cp; |
| 868 | u_int len; |
| 869 | |
| 870 | debug3("%s: entering fd = %d", __func__, fd); |
| 871 | |
| 872 | buffer_init(&m); |
| 873 | |
| 874 | if (ssh_msg_recv(fd, &m) == -1) |
| 875 | fatal("%s: ssh_msg_recv failed", __func__); |
| 876 | if (buffer_get_char(&m) != 0) |
| 877 | fatal("%s: rexec version mismatch", __func__); |
| 878 | |
| 879 | cp = buffer_get_string(&m, &len); |
| 880 | if (conf != NULL) |
| 881 | buffer_append(conf, cp, len + 1); |
| 882 | xfree(cp); |
| 883 | |
| 884 | if (buffer_get_int(&m)) { |
| 885 | if (sensitive_data.server_key != NULL) |
| 886 | key_free(sensitive_data.server_key); |
| 887 | sensitive_data.server_key = key_new_private(KEY_RSA1); |
| 888 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->e); |
| 889 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->n); |
| 890 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->d); |
| 891 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->iqmp); |
| 892 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->p); |
| 893 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->q); |
| 894 | rsa_generate_additional_parameters( |
| 895 | sensitive_data.server_key->rsa); |
| 896 | } |
Darren Tucker | c6f8219 | 2005-09-27 22:46:32 +1000 | [diff] [blame] | 897 | |
| 898 | #ifndef OPENSSL_PRNG_ONLY |
| 899 | rexec_recv_rng_seed(&m); |
| 900 | #endif |
| 901 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 902 | buffer_free(&m); |
| 903 | |
| 904 | debug3("%s: done", __func__); |
| 905 | } |
| 906 | |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 907 | /* Accept a connection from inetd */ |
| 908 | static void |
| 909 | server_accept_inetd(int *sock_in, int *sock_out) |
| 910 | { |
| 911 | int fd; |
| 912 | |
| 913 | startup_pipe = -1; |
| 914 | if (rexeced_flag) { |
| 915 | close(REEXEC_CONFIG_PASS_FD); |
| 916 | *sock_in = *sock_out = dup(STDIN_FILENO); |
| 917 | if (!debug_flag) { |
| 918 | startup_pipe = dup(REEXEC_STARTUP_PIPE_FD); |
| 919 | close(REEXEC_STARTUP_PIPE_FD); |
| 920 | } |
| 921 | } else { |
| 922 | *sock_in = dup(STDIN_FILENO); |
| 923 | *sock_out = dup(STDOUT_FILENO); |
| 924 | } |
| 925 | /* |
| 926 | * We intentionally do not close the descriptors 0, 1, and 2 |
| 927 | * as our code for setting the descriptors won't work if |
| 928 | * ttyfd happens to be one of those. |
| 929 | */ |
| 930 | if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { |
| 931 | dup2(fd, STDIN_FILENO); |
| 932 | dup2(fd, STDOUT_FILENO); |
| 933 | if (fd > STDOUT_FILENO) |
| 934 | close(fd); |
| 935 | } |
| 936 | debug("inetd sockets after dupping: %d, %d", *sock_in, *sock_out); |
| 937 | } |
| 938 | |
| 939 | /* |
| 940 | * Listen for TCP connections |
| 941 | */ |
| 942 | static void |
| 943 | server_listen(void) |
| 944 | { |
| 945 | int ret, listen_sock, on = 1; |
| 946 | struct addrinfo *ai; |
| 947 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
| 948 | |
| 949 | for (ai = options.listen_addrs; ai; ai = ai->ai_next) { |
| 950 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) |
| 951 | continue; |
| 952 | if (num_listen_socks >= MAX_LISTEN_SOCKS) |
| 953 | fatal("Too many listen sockets. " |
| 954 | "Enlarge MAX_LISTEN_SOCKS"); |
| 955 | if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen, |
| 956 | ntop, sizeof(ntop), strport, sizeof(strport), |
| 957 | NI_NUMERICHOST|NI_NUMERICSERV)) != 0) { |
| 958 | error("getnameinfo failed: %.100s", |
Darren Tucker | 4abde77 | 2007-12-29 02:43:51 +1100 | [diff] [blame] | 959 | ssh_gai_strerror(ret)); |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 960 | continue; |
| 961 | } |
| 962 | /* Create socket for listening. */ |
| 963 | listen_sock = socket(ai->ai_family, ai->ai_socktype, |
| 964 | ai->ai_protocol); |
| 965 | if (listen_sock < 0) { |
| 966 | /* kernel may not support ipv6 */ |
| 967 | verbose("socket: %.100s", strerror(errno)); |
| 968 | continue; |
| 969 | } |
| 970 | if (set_nonblock(listen_sock) == -1) { |
| 971 | close(listen_sock); |
| 972 | continue; |
| 973 | } |
| 974 | /* |
| 975 | * Set socket options. |
| 976 | * Allow local port reuse in TIME_WAIT. |
| 977 | */ |
| 978 | if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, |
| 979 | &on, sizeof(on)) == -1) |
| 980 | error("setsockopt SO_REUSEADDR: %s", strerror(errno)); |
| 981 | |
Damien Miller | 49d2a28 | 2008-01-20 08:56:00 +1100 | [diff] [blame] | 982 | #ifdef IPV6_V6ONLY |
| 983 | /* Only communicate in IPv6 over AF_INET6 sockets. */ |
| 984 | if (ai->ai_family == AF_INET6) { |
| 985 | if (setsockopt(listen_sock, IPPROTO_IPV6, IPV6_V6ONLY, |
| 986 | &on, sizeof(on)) == -1) |
| 987 | error("setsockopt IPV6_V6ONLY: %s", |
| 988 | strerror(errno)); |
| 989 | } |
| 990 | #endif |
| 991 | |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 992 | debug("Bind to port %s on %s.", strport, ntop); |
| 993 | |
| 994 | /* Bind the socket to the desired port. */ |
| 995 | if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) { |
| 996 | error("Bind to port %s on %s failed: %.200s.", |
| 997 | strport, ntop, strerror(errno)); |
| 998 | close(listen_sock); |
| 999 | continue; |
| 1000 | } |
| 1001 | listen_socks[num_listen_socks] = listen_sock; |
| 1002 | num_listen_socks++; |
| 1003 | |
| 1004 | /* Start listening on the port. */ |
| 1005 | if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0) |
| 1006 | fatal("listen on [%s]:%s: %.100s", |
| 1007 | ntop, strport, strerror(errno)); |
| 1008 | logit("Server listening on %s port %s.", ntop, strport); |
| 1009 | } |
| 1010 | freeaddrinfo(options.listen_addrs); |
| 1011 | |
| 1012 | if (!num_listen_socks) |
| 1013 | fatal("Cannot bind any address."); |
| 1014 | } |
| 1015 | |
| 1016 | /* |
| 1017 | * The main TCP accept loop. Note that, for the non-debug case, returns |
| 1018 | * from this function are in a forked subprocess. |
| 1019 | */ |
| 1020 | static void |
| 1021 | server_accept_loop(int *sock_in, int *sock_out, int *newsock, int *config_s) |
| 1022 | { |
| 1023 | fd_set *fdset; |
| 1024 | int i, j, ret, maxfd; |
| 1025 | int key_used = 0, startups = 0; |
| 1026 | int startup_p[2] = { -1 , -1 }; |
| 1027 | struct sockaddr_storage from; |
| 1028 | socklen_t fromlen; |
| 1029 | pid_t pid; |
| 1030 | |
| 1031 | /* setup fd set for accept */ |
| 1032 | fdset = NULL; |
| 1033 | maxfd = 0; |
| 1034 | for (i = 0; i < num_listen_socks; i++) |
| 1035 | if (listen_socks[i] > maxfd) |
| 1036 | maxfd = listen_socks[i]; |
| 1037 | /* pipes connected to unauthenticated childs */ |
| 1038 | startup_pipes = xcalloc(options.max_startups, sizeof(int)); |
| 1039 | for (i = 0; i < options.max_startups; i++) |
| 1040 | startup_pipes[i] = -1; |
| 1041 | |
| 1042 | /* |
| 1043 | * Stay listening for connections until the system crashes or |
| 1044 | * the daemon is killed with a signal. |
| 1045 | */ |
| 1046 | for (;;) { |
| 1047 | if (received_sighup) |
| 1048 | sighup_restart(); |
| 1049 | if (fdset != NULL) |
| 1050 | xfree(fdset); |
| 1051 | fdset = (fd_set *)xcalloc(howmany(maxfd + 1, NFDBITS), |
| 1052 | sizeof(fd_mask)); |
| 1053 | |
| 1054 | for (i = 0; i < num_listen_socks; i++) |
| 1055 | FD_SET(listen_socks[i], fdset); |
| 1056 | for (i = 0; i < options.max_startups; i++) |
| 1057 | if (startup_pipes[i] != -1) |
| 1058 | FD_SET(startup_pipes[i], fdset); |
| 1059 | |
| 1060 | /* Wait in select until there is a connection. */ |
| 1061 | ret = select(maxfd+1, fdset, NULL, NULL, NULL); |
| 1062 | if (ret < 0 && errno != EINTR) |
| 1063 | error("select: %.100s", strerror(errno)); |
| 1064 | if (received_sigterm) { |
| 1065 | logit("Received signal %d; terminating.", |
| 1066 | (int) received_sigterm); |
| 1067 | close_listen_socks(); |
| 1068 | unlink(options.pid_file); |
| 1069 | exit(255); |
| 1070 | } |
| 1071 | if (key_used && key_do_regen) { |
| 1072 | generate_ephemeral_server_key(); |
| 1073 | key_used = 0; |
| 1074 | key_do_regen = 0; |
| 1075 | } |
| 1076 | if (ret < 0) |
| 1077 | continue; |
| 1078 | |
| 1079 | for (i = 0; i < options.max_startups; i++) |
| 1080 | if (startup_pipes[i] != -1 && |
| 1081 | FD_ISSET(startup_pipes[i], fdset)) { |
| 1082 | /* |
| 1083 | * the read end of the pipe is ready |
| 1084 | * if the child has closed the pipe |
| 1085 | * after successful authentication |
| 1086 | * or if the child has died |
| 1087 | */ |
| 1088 | close(startup_pipes[i]); |
| 1089 | startup_pipes[i] = -1; |
| 1090 | startups--; |
| 1091 | } |
| 1092 | for (i = 0; i < num_listen_socks; i++) { |
| 1093 | if (!FD_ISSET(listen_socks[i], fdset)) |
| 1094 | continue; |
| 1095 | fromlen = sizeof(from); |
| 1096 | *newsock = accept(listen_socks[i], |
| 1097 | (struct sockaddr *)&from, &fromlen); |
| 1098 | if (*newsock < 0) { |
| 1099 | if (errno != EINTR && errno != EWOULDBLOCK) |
| 1100 | error("accept: %.100s", strerror(errno)); |
| 1101 | continue; |
| 1102 | } |
| 1103 | if (unset_nonblock(*newsock) == -1) { |
| 1104 | close(*newsock); |
| 1105 | continue; |
| 1106 | } |
| 1107 | if (drop_connection(startups) == 1) { |
| 1108 | debug("drop connection #%d", startups); |
| 1109 | close(*newsock); |
| 1110 | continue; |
| 1111 | } |
| 1112 | if (pipe(startup_p) == -1) { |
| 1113 | close(*newsock); |
| 1114 | continue; |
| 1115 | } |
| 1116 | |
| 1117 | if (rexec_flag && socketpair(AF_UNIX, |
| 1118 | SOCK_STREAM, 0, config_s) == -1) { |
| 1119 | error("reexec socketpair: %s", |
| 1120 | strerror(errno)); |
| 1121 | close(*newsock); |
| 1122 | close(startup_p[0]); |
| 1123 | close(startup_p[1]); |
| 1124 | continue; |
| 1125 | } |
| 1126 | |
| 1127 | for (j = 0; j < options.max_startups; j++) |
| 1128 | if (startup_pipes[j] == -1) { |
| 1129 | startup_pipes[j] = startup_p[0]; |
| 1130 | if (maxfd < startup_p[0]) |
| 1131 | maxfd = startup_p[0]; |
| 1132 | startups++; |
| 1133 | break; |
| 1134 | } |
| 1135 | |
| 1136 | /* |
| 1137 | * Got connection. Fork a child to handle it, unless |
| 1138 | * we are in debugging mode. |
| 1139 | */ |
| 1140 | if (debug_flag) { |
| 1141 | /* |
| 1142 | * In debugging mode. Close the listening |
| 1143 | * socket, and start processing the |
| 1144 | * connection without forking. |
| 1145 | */ |
| 1146 | debug("Server will not fork when running in debugging mode."); |
| 1147 | close_listen_socks(); |
| 1148 | *sock_in = *newsock; |
| 1149 | *sock_out = *newsock; |
| 1150 | close(startup_p[0]); |
| 1151 | close(startup_p[1]); |
| 1152 | startup_pipe = -1; |
| 1153 | pid = getpid(); |
| 1154 | if (rexec_flag) { |
| 1155 | send_rexec_state(config_s[0], |
| 1156 | &cfg); |
| 1157 | close(config_s[0]); |
| 1158 | } |
| 1159 | break; |
| 1160 | } |
| 1161 | |
| 1162 | /* |
| 1163 | * Normal production daemon. Fork, and have |
| 1164 | * the child process the connection. The |
| 1165 | * parent continues listening. |
| 1166 | */ |
Damien Miller | 1b06dc3 | 2006-08-31 03:24:41 +1000 | [diff] [blame] | 1167 | platform_pre_fork(); |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 1168 | if ((pid = fork()) == 0) { |
| 1169 | /* |
| 1170 | * Child. Close the listening and |
| 1171 | * max_startup sockets. Start using |
| 1172 | * the accepted socket. Reinitialize |
| 1173 | * logging (since our pid has changed). |
| 1174 | * We break out of the loop to handle |
| 1175 | * the connection. |
| 1176 | */ |
Damien Miller | 1b06dc3 | 2006-08-31 03:24:41 +1000 | [diff] [blame] | 1177 | platform_post_fork_child(); |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 1178 | startup_pipe = startup_p[1]; |
| 1179 | close_startup_pipes(); |
| 1180 | close_listen_socks(); |
| 1181 | *sock_in = *newsock; |
| 1182 | *sock_out = *newsock; |
| 1183 | log_init(__progname, |
| 1184 | options.log_level, |
| 1185 | options.log_facility, |
| 1186 | log_stderr); |
| 1187 | if (rexec_flag) |
| 1188 | close(config_s[0]); |
| 1189 | break; |
| 1190 | } |
| 1191 | |
| 1192 | /* Parent. Stay in the loop. */ |
Damien Miller | 1b06dc3 | 2006-08-31 03:24:41 +1000 | [diff] [blame] | 1193 | platform_post_fork_parent(pid); |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 1194 | if (pid < 0) |
| 1195 | error("fork: %.100s", strerror(errno)); |
| 1196 | else |
| 1197 | debug("Forked child %ld.", (long)pid); |
| 1198 | |
| 1199 | close(startup_p[1]); |
| 1200 | |
| 1201 | if (rexec_flag) { |
| 1202 | send_rexec_state(config_s[0], &cfg); |
| 1203 | close(config_s[0]); |
| 1204 | close(config_s[1]); |
| 1205 | } |
| 1206 | |
| 1207 | /* |
| 1208 | * Mark that the key has been used (it |
| 1209 | * was "given" to the child). |
| 1210 | */ |
| 1211 | if ((options.protocol & SSH_PROTO_1) && |
| 1212 | key_used == 0) { |
| 1213 | /* Schedule server key regeneration alarm. */ |
| 1214 | signal(SIGALRM, key_regeneration_alarm); |
| 1215 | alarm(options.key_regeneration_time); |
| 1216 | key_used = 1; |
| 1217 | } |
| 1218 | |
| 1219 | close(*newsock); |
| 1220 | |
| 1221 | /* |
| 1222 | * Ensure that our random state differs |
| 1223 | * from that of the child |
| 1224 | */ |
| 1225 | arc4random_stir(); |
| 1226 | } |
| 1227 | |
| 1228 | /* child process check (or debug mode) */ |
| 1229 | if (num_listen_socks < 0) |
| 1230 | break; |
| 1231 | } |
| 1232 | } |
| 1233 | |
| 1234 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1235 | /* |
| 1236 | * Main program for the daemon. |
| 1237 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1238 | int |
| 1239 | main(int ac, char **av) |
| 1240 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1241 | extern char *optarg; |
| 1242 | extern int optind; |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 1243 | int opt, i, on = 1; |
Damien Miller | 386c6a2 | 2004-06-30 22:40:20 +1000 | [diff] [blame] | 1244 | int sock_in = -1, sock_out = -1, newsock = -1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1245 | const char *remote_ip; |
Darren Tucker | e7140f2 | 2008-06-10 23:01:51 +1000 | [diff] [blame] | 1246 | char *test_user = NULL, *test_host = NULL, *test_addr = NULL; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1247 | int remote_port; |
Darren Tucker | e7140f2 | 2008-06-10 23:01:51 +1000 | [diff] [blame] | 1248 | char *line, *p, *cp; |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 1249 | int config_s[2] = { -1 , -1 }; |
Damien Miller | 6ca16c6 | 2008-06-16 07:50:58 +1000 | [diff] [blame] | 1250 | mode_t new_umask; |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame] | 1251 | Key *key; |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1252 | Authctxt *authctxt; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1253 | |
Kevin Steves | 0ea1d9d | 2002-04-25 18:17:04 +0000 | [diff] [blame] | 1254 | #ifdef HAVE_SECUREWARE |
| 1255 | (void)set_auth_parameters(ac, av); |
| 1256 | #endif |
Damien Miller | 59d3d5b | 2003-08-22 09:34:41 +1000 | [diff] [blame] | 1257 | __progname = ssh_get_progname(av[0]); |
Damien Miller | f9b625c | 2000-07-09 22:42:32 +1000 | [diff] [blame] | 1258 | init_rng(); |
| 1259 | |
Damien Miller | a8ed44b | 2003-01-10 09:53:12 +1100 | [diff] [blame] | 1260 | /* Save argv. Duplicate so setproctitle emulation doesn't clobber it */ |
Damien Miller | b8c656e | 2000-06-28 15:22:41 +1000 | [diff] [blame] | 1261 | saved_argc = ac; |
Darren Tucker | 17c5d03 | 2004-06-25 14:22:23 +1000 | [diff] [blame] | 1262 | rexec_argc = ac; |
Darren Tucker | d8093e4 | 2006-05-04 16:24:34 +1000 | [diff] [blame] | 1263 | saved_argv = xcalloc(ac + 1, sizeof(*saved_argv)); |
Damien Miller | a8ed44b | 2003-01-10 09:53:12 +1100 | [diff] [blame] | 1264 | for (i = 0; i < ac; i++) |
| 1265 | saved_argv[i] = xstrdup(av[i]); |
Damien Miller | 04cb536 | 2003-05-15 21:29:10 +1000 | [diff] [blame] | 1266 | saved_argv[i] = NULL; |
Damien Miller | a8ed44b | 2003-01-10 09:53:12 +1100 | [diff] [blame] | 1267 | |
| 1268 | #ifndef HAVE_SETPROCTITLE |
| 1269 | /* Prepare for later setproctitle emulation */ |
| 1270 | compat_init_setproctitle(ac, av); |
Damien Miller | f2e3e9d | 2003-06-02 12:15:54 +1000 | [diff] [blame] | 1271 | av = saved_argv; |
Damien Miller | a8ed44b | 2003-01-10 09:53:12 +1100 | [diff] [blame] | 1272 | #endif |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1273 | |
Damien Miller | bfba354 | 2004-03-22 09:29:57 +1100 | [diff] [blame] | 1274 | if (geteuid() == 0 && setgroups(0, NULL) == -1) |
| 1275 | debug("setgroups(): %.200s", strerror(errno)); |
| 1276 | |
Darren Tucker | ce321d8 | 2005-10-03 18:11:24 +1000 | [diff] [blame] | 1277 | /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ |
| 1278 | sanitise_stdfd(); |
| 1279 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1280 | /* Initialize configuration options to their default values. */ |
| 1281 | initialize_server_options(&options); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1282 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1283 | /* Parse command-line arguments. */ |
Darren Tucker | e7140f2 | 2008-06-10 23:01:51 +1000 | [diff] [blame] | 1284 | while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:C:dDeiqrtQRT46")) != -1) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1285 | switch (opt) { |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1286 | case '4': |
Darren Tucker | 0f38323 | 2005-01-20 10:57:56 +1100 | [diff] [blame] | 1287 | options.address_family = AF_INET; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1288 | break; |
| 1289 | case '6': |
Darren Tucker | 0f38323 | 2005-01-20 10:57:56 +1100 | [diff] [blame] | 1290 | options.address_family = AF_INET6; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1291 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1292 | case 'f': |
| 1293 | config_file_name = optarg; |
| 1294 | break; |
| 1295 | case 'd': |
Darren Tucker | e98dfa3 | 2003-07-19 19:54:31 +1000 | [diff] [blame] | 1296 | if (debug_flag == 0) { |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 1297 | debug_flag = 1; |
| 1298 | options.log_level = SYSLOG_LEVEL_DEBUG1; |
Darren Tucker | e98dfa3 | 2003-07-19 19:54:31 +1000 | [diff] [blame] | 1299 | } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 1300 | options.log_level++; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1301 | break; |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 1302 | case 'D': |
| 1303 | no_daemon_flag = 1; |
| 1304 | break; |
Ben Lindstrom | 9fce9f0 | 2001-04-11 23:10:09 +0000 | [diff] [blame] | 1305 | case 'e': |
| 1306 | log_stderr = 1; |
| 1307 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1308 | case 'i': |
| 1309 | inetd_flag = 1; |
| 1310 | break; |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1311 | case 'r': |
| 1312 | rexec_flag = 0; |
| 1313 | break; |
| 1314 | case 'R': |
| 1315 | rexeced_flag = 1; |
| 1316 | inetd_flag = 1; |
| 1317 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1318 | case 'Q': |
Ben Lindstrom | d539020 | 2001-01-29 08:07:43 +0000 | [diff] [blame] | 1319 | /* ignored */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1320 | break; |
| 1321 | case 'q': |
| 1322 | options.log_level = SYSLOG_LEVEL_QUIET; |
| 1323 | break; |
| 1324 | case 'b': |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1325 | options.server_key_bits = (int)strtonum(optarg, 256, |
| 1326 | 32768, NULL); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1327 | break; |
| 1328 | case 'p': |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1329 | options.ports_from_cmdline = 1; |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 1330 | if (options.num_ports >= MAX_PORTS) { |
| 1331 | fprintf(stderr, "too many ports.\n"); |
| 1332 | exit(1); |
| 1333 | } |
Ben Lindstrom | 19066a1 | 2001-04-12 23:39:26 +0000 | [diff] [blame] | 1334 | options.ports[options.num_ports++] = a2port(optarg); |
| 1335 | if (options.ports[options.num_ports-1] == 0) { |
| 1336 | fprintf(stderr, "Bad port number.\n"); |
| 1337 | exit(1); |
| 1338 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1339 | break; |
| 1340 | case 'g': |
Ben Lindstrom | 1bda4c8 | 2001-06-05 19:59:08 +0000 | [diff] [blame] | 1341 | if ((options.login_grace_time = convtime(optarg)) == -1) { |
| 1342 | fprintf(stderr, "Invalid login grace time.\n"); |
| 1343 | exit(1); |
| 1344 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1345 | break; |
| 1346 | case 'k': |
Ben Lindstrom | 1bda4c8 | 2001-06-05 19:59:08 +0000 | [diff] [blame] | 1347 | if ((options.key_regeneration_time = convtime(optarg)) == -1) { |
| 1348 | fprintf(stderr, "Invalid key regeneration interval.\n"); |
| 1349 | exit(1); |
| 1350 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1351 | break; |
| 1352 | case 'h': |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1353 | if (options.num_host_key_files >= MAX_HOSTKEYS) { |
| 1354 | fprintf(stderr, "too many host keys.\n"); |
| 1355 | exit(1); |
| 1356 | } |
| 1357 | options.host_key_files[options.num_host_key_files++] = optarg; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1358 | break; |
Ben Lindstrom | 794325a | 2001-08-06 21:09:07 +0000 | [diff] [blame] | 1359 | case 't': |
| 1360 | test_flag = 1; |
| 1361 | break; |
Darren Tucker | e7140f2 | 2008-06-10 23:01:51 +1000 | [diff] [blame] | 1362 | case 'T': |
| 1363 | test_flag = 2; |
| 1364 | break; |
| 1365 | case 'C': |
| 1366 | cp = optarg; |
| 1367 | while ((p = strsep(&cp, ",")) && *p != '\0') { |
| 1368 | if (strncmp(p, "addr=", 5) == 0) |
| 1369 | test_addr = xstrdup(p + 5); |
| 1370 | else if (strncmp(p, "host=", 5) == 0) |
| 1371 | test_host = xstrdup(p + 5); |
| 1372 | else if (strncmp(p, "user=", 5) == 0) |
| 1373 | test_user = xstrdup(p + 5); |
| 1374 | else { |
| 1375 | fprintf(stderr, "Invalid test " |
| 1376 | "mode specification %s\n", p); |
| 1377 | exit(1); |
| 1378 | } |
| 1379 | } |
| 1380 | break; |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 1381 | case 'u': |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1382 | utmp_len = (u_int)strtonum(optarg, 0, MAXHOSTNAMELEN+1, NULL); |
Ben Lindstrom | 41daec7 | 2002-07-23 21:15:13 +0000 | [diff] [blame] | 1383 | if (utmp_len > MAXHOSTNAMELEN) { |
| 1384 | fprintf(stderr, "Invalid utmp length.\n"); |
| 1385 | exit(1); |
| 1386 | } |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 1387 | break; |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 1388 | case 'o': |
Damien Miller | b999719 | 2003-12-17 16:29:22 +1100 | [diff] [blame] | 1389 | line = xstrdup(optarg); |
| 1390 | if (process_server_config_line(&options, line, |
Darren Tucker | 4515047 | 2006-07-12 22:34:17 +1000 | [diff] [blame] | 1391 | "command-line", 0, NULL, NULL, NULL, NULL) != 0) |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1392 | exit(1); |
Damien Miller | b999719 | 2003-12-17 16:29:22 +1100 | [diff] [blame] | 1393 | xfree(line); |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 1394 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1395 | case '?': |
| 1396 | default: |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 1397 | usage(); |
| 1398 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1399 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1400 | } |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1401 | if (rexeced_flag || inetd_flag) |
| 1402 | rexec_flag = 0; |
Damien Miller | 2ee0c43 | 2008-03-07 18:31:47 +1100 | [diff] [blame] | 1403 | if (!test_flag && (rexec_flag && (av[0] == NULL || *av[0] != '/'))) |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1404 | fatal("sshd re-exec requires execution with an absolute path"); |
| 1405 | if (rexeced_flag) |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1406 | closefrom(REEXEC_MIN_FREE_FD); |
| 1407 | else |
| 1408 | closefrom(REEXEC_DEVCRYPTO_RESERVED_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1409 | |
Ben Lindstrom | 425fb02 | 2001-03-29 00:31:20 +0000 | [diff] [blame] | 1410 | SSLeay_add_all_algorithms(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1411 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1412 | /* |
| 1413 | * Force logging to stderr until we have loaded the private host |
| 1414 | * key (unless started from inetd) |
| 1415 | */ |
Kevin Steves | ec84dc1 | 2000-12-13 17:45:15 +0000 | [diff] [blame] | 1416 | log_init(__progname, |
Damien Miller | 5aa5d78 | 2002-02-08 22:01:54 +1100 | [diff] [blame] | 1417 | options.log_level == SYSLOG_LEVEL_NOT_SET ? |
| 1418 | SYSLOG_LEVEL_INFO : options.log_level, |
| 1419 | options.log_facility == SYSLOG_FACILITY_NOT_SET ? |
| 1420 | SYSLOG_FACILITY_AUTH : options.log_facility, |
Ben Lindstrom | c2faa4a | 2002-11-09 15:50:03 +0000 | [diff] [blame] | 1421 | log_stderr || !inetd_flag); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1422 | |
Darren Tucker | 86c093d | 2004-03-08 22:59:03 +1100 | [diff] [blame] | 1423 | /* |
| 1424 | * Unset KRB5CCNAME, otherwise the user's session may inherit it from |
| 1425 | * root's environment |
Damien Miller | 94cf4c8 | 2005-07-17 17:04:47 +1000 | [diff] [blame] | 1426 | */ |
Darren Tucker | 9dc6c7d | 2005-02-02 18:30:33 +1100 | [diff] [blame] | 1427 | if (getenv("KRB5CCNAME") != NULL) |
| 1428 | unsetenv("KRB5CCNAME"); |
| 1429 | |
Tim Rice | 81ed518 | 2002-09-25 17:38:46 -0700 | [diff] [blame] | 1430 | #ifdef _UNICOS |
Darren Tucker | 1298496 | 2004-05-24 13:37:13 +1000 | [diff] [blame] | 1431 | /* Cray can define user privs drop all privs now! |
Ben Lindstrom | 6db66ff | 2001-08-06 23:29:16 +0000 | [diff] [blame] | 1432 | * Not needed on PRIV_SU systems! |
| 1433 | */ |
| 1434 | drop_cray_privs(); |
| 1435 | #endif |
| 1436 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1437 | sensitive_data.server_key = NULL; |
| 1438 | sensitive_data.ssh1_host_key = NULL; |
| 1439 | sensitive_data.have_ssh1_key = 0; |
| 1440 | sensitive_data.have_ssh2_key = 0; |
| 1441 | |
Darren Tucker | e7140f2 | 2008-06-10 23:01:51 +1000 | [diff] [blame] | 1442 | /* |
| 1443 | * If we're doing an extended config test, make sure we have all of |
| 1444 | * the parameters we need. If we're not doing an extended test, |
| 1445 | * do not silently ignore connection test params. |
| 1446 | */ |
Damien Miller | 2a62847 | 2008-06-16 07:50:24 +1000 | [diff] [blame] | 1447 | if (test_flag >= 2 && |
| 1448 | (test_user != NULL || test_host != NULL || test_addr != NULL) |
Darren Tucker | e7140f2 | 2008-06-10 23:01:51 +1000 | [diff] [blame] | 1449 | && (test_user == NULL || test_host == NULL || test_addr == NULL)) |
| 1450 | fatal("user, host and addr are all required when testing " |
| 1451 | "Match configs"); |
| 1452 | if (test_flag < 2 && (test_user != NULL || test_host != NULL || |
| 1453 | test_addr != NULL)) |
| 1454 | fatal("Config test connection parameter (-C) provided without " |
| 1455 | "test mode (-T)"); |
| 1456 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1457 | /* Fetch our configuration */ |
| 1458 | buffer_init(&cfg); |
| 1459 | if (rexeced_flag) |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1460 | recv_rexec_state(REEXEC_CONFIG_PASS_FD, &cfg); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1461 | else |
| 1462 | load_server_config(config_file_name, &cfg); |
| 1463 | |
Darren Tucker | 4515047 | 2006-07-12 22:34:17 +1000 | [diff] [blame] | 1464 | parse_server_config(&options, rexeced_flag ? "rexec" : config_file_name, |
| 1465 | &cfg, NULL, NULL, NULL); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1466 | |
Darren Tucker | c6f8219 | 2005-09-27 22:46:32 +1000 | [diff] [blame] | 1467 | seed_rng(); |
| 1468 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1469 | /* Fill in default values for those options not explicitly set. */ |
| 1470 | fill_default_server_options(&options); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1471 | |
Darren Tucker | 97b1bb5 | 2007-03-21 20:38:53 +1100 | [diff] [blame] | 1472 | /* challenge-response is implemented via keyboard interactive */ |
| 1473 | if (options.challenge_response_authentication) |
| 1474 | options.kbd_interactive_authentication = 1; |
| 1475 | |
Darren Tucker | 0f38323 | 2005-01-20 10:57:56 +1100 | [diff] [blame] | 1476 | /* set default channel AF */ |
| 1477 | channel_set_af(options.address_family); |
| 1478 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1479 | /* Check that there are no remaining arguments. */ |
| 1480 | if (optind < ac) { |
| 1481 | fprintf(stderr, "Extra argument %s.\n", av[optind]); |
| 1482 | exit(1); |
| 1483 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1484 | |
Damien Miller | 2aa6d3c | 2004-09-12 16:53:04 +1000 | [diff] [blame] | 1485 | debug("sshd version %.100s", SSH_RELEASE); |
Damien Miller | 2ccf661 | 1999-11-15 15:25:10 +1100 | [diff] [blame] | 1486 | |
Darren Tucker | df0e438 | 2006-11-07 11:28:40 +1100 | [diff] [blame] | 1487 | /* Store privilege separation user for later use if required. */ |
| 1488 | if ((privsep_pw = getpwnam(SSH_PRIVSEP_USER)) == NULL) { |
| 1489 | if (use_privsep || options.kerberos_authentication) |
| 1490 | fatal("Privilege separation user %s does not exist", |
| 1491 | SSH_PRIVSEP_USER); |
| 1492 | } else { |
| 1493 | memset(privsep_pw->pw_passwd, 0, strlen(privsep_pw->pw_passwd)); |
| 1494 | privsep_pw = pwcopy(privsep_pw); |
| 1495 | xfree(privsep_pw->pw_passwd); |
| 1496 | privsep_pw->pw_passwd = xstrdup("*"); |
| 1497 | } |
Damien Miller | 6433df0 | 2006-09-07 10:36:43 +1000 | [diff] [blame] | 1498 | endpwent(); |
| 1499 | |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1500 | /* load private host keys */ |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1501 | sensitive_data.host_keys = xcalloc(options.num_host_key_files, |
Ben Lindstrom | a962c2f | 2002-07-04 00:14:17 +0000 | [diff] [blame] | 1502 | sizeof(Key *)); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1503 | for (i = 0; i < options.num_host_key_files; i++) |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1504 | sensitive_data.host_keys[i] = NULL; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1505 | |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1506 | for (i = 0; i < options.num_host_key_files; i++) { |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame] | 1507 | key = key_load_private(options.host_key_files[i], "", NULL); |
| 1508 | sensitive_data.host_keys[i] = key; |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1509 | if (key == NULL) { |
Ben Lindstrom | 15f3386 | 2001-04-16 02:00:02 +0000 | [diff] [blame] | 1510 | error("Could not load host key: %s", |
| 1511 | options.host_key_files[i]); |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame] | 1512 | sensitive_data.host_keys[i] = NULL; |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1513 | continue; |
| 1514 | } |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 1515 | switch (key->type) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1516 | case KEY_RSA1: |
| 1517 | sensitive_data.ssh1_host_key = key; |
| 1518 | sensitive_data.have_ssh1_key = 1; |
| 1519 | break; |
| 1520 | case KEY_RSA: |
| 1521 | case KEY_DSA: |
| 1522 | sensitive_data.have_ssh2_key = 1; |
| 1523 | break; |
| 1524 | } |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame] | 1525 | debug("private host key: #%d type %d %s", i, key->type, |
| 1526 | key_type(key)); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1527 | } |
| 1528 | if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 1529 | logit("Disabling protocol version 1. Could not load host key"); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1530 | options.protocol &= ~SSH_PROTO_1; |
| 1531 | } |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1532 | if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 1533 | logit("Disabling protocol version 2. Could not load host key"); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1534 | options.protocol &= ~SSH_PROTO_2; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1535 | } |
Kevin Steves | adf74cd | 2001-02-05 14:22:50 +0000 | [diff] [blame] | 1536 | if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 1537 | logit("sshd: no hostkeys available -- exiting."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1538 | exit(1); |
| 1539 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1540 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1541 | /* Check certain values for sanity. */ |
| 1542 | if (options.protocol & SSH_PROTO_1) { |
| 1543 | if (options.server_key_bits < 512 || |
| 1544 | options.server_key_bits > 32768) { |
| 1545 | fprintf(stderr, "Bad server key size.\n"); |
| 1546 | exit(1); |
| 1547 | } |
| 1548 | /* |
| 1549 | * Check that server and host key lengths differ sufficiently. This |
| 1550 | * is necessary to make double encryption work with rsaref. Oh, I |
| 1551 | * hate software patents. I dont know if this can go? Niels |
| 1552 | */ |
| 1553 | if (options.server_key_bits > |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 1554 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) - |
| 1555 | SSH_KEY_BITS_RESERVED && options.server_key_bits < |
| 1556 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + |
| 1557 | SSH_KEY_BITS_RESERVED) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1558 | options.server_key_bits = |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 1559 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + |
| 1560 | SSH_KEY_BITS_RESERVED; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1561 | debug("Forcing server key to %d bits to make it differ from host key.", |
| 1562 | options.server_key_bits); |
| 1563 | } |
| 1564 | } |
| 1565 | |
Ben Lindstrom | a26ea63 | 2002-06-06 20:46:25 +0000 | [diff] [blame] | 1566 | if (use_privsep) { |
Ben Lindstrom | a26ea63 | 2002-06-06 20:46:25 +0000 | [diff] [blame] | 1567 | struct stat st; |
| 1568 | |
Ben Lindstrom | a26ea63 | 2002-06-06 20:46:25 +0000 | [diff] [blame] | 1569 | if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) || |
| 1570 | (S_ISDIR(st.st_mode) == 0)) |
| 1571 | fatal("Missing privilege separation directory: %s", |
| 1572 | _PATH_PRIVSEP_CHROOT_DIR); |
Ben Lindstrom | 5962735 | 2002-06-27 18:02:21 +0000 | [diff] [blame] | 1573 | |
| 1574 | #ifdef HAVE_CYGWIN |
| 1575 | if (check_ntsec(_PATH_PRIVSEP_CHROOT_DIR) && |
| 1576 | (st.st_uid != getuid () || |
| 1577 | (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)) |
| 1578 | #else |
Ben Lindstrom | 2dfacb3 | 2002-06-23 00:33:47 +0000 | [diff] [blame] | 1579 | if (st.st_uid != 0 || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0) |
Ben Lindstrom | 5962735 | 2002-06-27 18:02:21 +0000 | [diff] [blame] | 1580 | #endif |
Damien Miller | 180fc5b | 2003-02-24 11:50:18 +1100 | [diff] [blame] | 1581 | fatal("%s must be owned by root and not group or " |
| 1582 | "world-writable.", _PATH_PRIVSEP_CHROOT_DIR); |
Ben Lindstrom | a26ea63 | 2002-06-06 20:46:25 +0000 | [diff] [blame] | 1583 | } |
| 1584 | |
Darren Tucker | e7140f2 | 2008-06-10 23:01:51 +1000 | [diff] [blame] | 1585 | if (test_flag > 1) { |
| 1586 | if (test_user != NULL && test_addr != NULL && test_host != NULL) |
| 1587 | parse_server_match_config(&options, test_user, |
| 1588 | test_host, test_addr); |
| 1589 | dump_config(&options); |
| 1590 | } |
| 1591 | |
Ben Lindstrom | 794325a | 2001-08-06 21:09:07 +0000 | [diff] [blame] | 1592 | /* Configuration looks good, so exit if in test mode. */ |
| 1593 | if (test_flag) |
| 1594 | exit(0); |
| 1595 | |
Damien Miller | 87aea25 | 2002-05-10 12:20:24 +1000 | [diff] [blame] | 1596 | /* |
| 1597 | * Clear out any supplemental groups we may have inherited. This |
| 1598 | * prevents inadvertent creation of files with bad modes (in the |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 1599 | * portable version at least, it's certainly possible for PAM |
| 1600 | * to create a file, and we can't control the code in every |
Damien Miller | 87aea25 | 2002-05-10 12:20:24 +1000 | [diff] [blame] | 1601 | * module which might be used). |
| 1602 | */ |
| 1603 | if (setgroups(0, NULL) < 0) |
| 1604 | debug("setgroups() failed: %.200s", strerror(errno)); |
| 1605 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1606 | if (rexec_flag) { |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1607 | rexec_argv = xcalloc(rexec_argc + 2, sizeof(char *)); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1608 | for (i = 0; i < rexec_argc; i++) { |
| 1609 | debug("rexec_argv[%d]='%s'", i, saved_argv[i]); |
| 1610 | rexec_argv[i] = saved_argv[i]; |
| 1611 | } |
| 1612 | rexec_argv[rexec_argc] = "-R"; |
| 1613 | rexec_argv[rexec_argc + 1] = NULL; |
| 1614 | } |
| 1615 | |
Damien Miller | 6ca16c6 | 2008-06-16 07:50:58 +1000 | [diff] [blame] | 1616 | /* Ensure that umask disallows at least group and world write */ |
| 1617 | new_umask = umask(0077) | 0022; |
| 1618 | (void) umask(new_umask); |
| 1619 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1620 | /* Initialize the log (it is reinitialized below in case we forked). */ |
Darren Tucker | ea7c812 | 2005-01-20 11:03:08 +1100 | [diff] [blame] | 1621 | if (debug_flag && (!inetd_flag || rexeced_flag)) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1622 | log_stderr = 1; |
Kevin Steves | ec84dc1 | 2000-12-13 17:45:15 +0000 | [diff] [blame] | 1623 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1624 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1625 | /* |
| 1626 | * If not in debugging mode, and not started from inetd, disconnect |
| 1627 | * from the controlling terminal, and fork. The original process |
| 1628 | * exits. |
| 1629 | */ |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 1630 | if (!(debug_flag || inetd_flag || no_daemon_flag)) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1631 | #ifdef TIOCNOTTY |
| 1632 | int fd; |
| 1633 | #endif /* TIOCNOTTY */ |
| 1634 | if (daemon(0, 0) < 0) |
| 1635 | fatal("daemon() failed: %.200s", strerror(errno)); |
| 1636 | |
| 1637 | /* Disconnect from the controlling tty. */ |
| 1638 | #ifdef TIOCNOTTY |
Ben Lindstrom | 31ca54a | 2001-02-09 02:11:24 +0000 | [diff] [blame] | 1639 | fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1640 | if (fd >= 0) { |
| 1641 | (void) ioctl(fd, TIOCNOTTY, NULL); |
| 1642 | close(fd); |
| 1643 | } |
| 1644 | #endif /* TIOCNOTTY */ |
| 1645 | } |
| 1646 | /* Reinitialize the log (because of the fork above). */ |
Kevin Steves | ec84dc1 | 2000-12-13 17:45:15 +0000 | [diff] [blame] | 1647 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1648 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1649 | /* Initialize the random number generator. */ |
| 1650 | arc4random_stir(); |
| 1651 | |
| 1652 | /* Chdir to the root directory so that the current disk can be |
| 1653 | unmounted if desired. */ |
| 1654 | chdir("/"); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1655 | |
Ben Lindstrom | de71cda | 2001-03-24 00:43:26 +0000 | [diff] [blame] | 1656 | /* ignore SIGPIPE */ |
| 1657 | signal(SIGPIPE, SIG_IGN); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1658 | |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 1659 | /* Get a connection, either from inetd or a listening TCP socket */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1660 | if (inetd_flag) { |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 1661 | server_accept_inetd(&sock_in, &sock_out); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1662 | } else { |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 1663 | server_listen(); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1664 | |
Ben Lindstrom | 9809786 | 2001-06-25 05:10:20 +0000 | [diff] [blame] | 1665 | if (options.protocol & SSH_PROTO_1) |
| 1666 | generate_ephemeral_server_key(); |
| 1667 | |
Ben Lindstrom | 9809786 | 2001-06-25 05:10:20 +0000 | [diff] [blame] | 1668 | signal(SIGHUP, sighup_handler); |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 1669 | signal(SIGCHLD, main_sigchld_handler); |
Ben Lindstrom | 9809786 | 2001-06-25 05:10:20 +0000 | [diff] [blame] | 1670 | signal(SIGTERM, sigterm_handler); |
| 1671 | signal(SIGQUIT, sigterm_handler); |
| 1672 | |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 1673 | /* |
| 1674 | * Write out the pid file after the sigterm handler |
| 1675 | * is setup and the listen sockets are bound |
| 1676 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1677 | if (!debug_flag) { |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 1678 | FILE *f = fopen(options.pid_file, "w"); |
| 1679 | |
Darren Tucker | e532704 | 2003-07-03 13:40:44 +1000 | [diff] [blame] | 1680 | if (f == NULL) { |
| 1681 | error("Couldn't create pid file \"%s\": %s", |
| 1682 | options.pid_file, strerror(errno)); |
| 1683 | } else { |
Ben Lindstrom | ce0f634 | 2002-06-11 16:42:49 +0000 | [diff] [blame] | 1684 | fprintf(f, "%ld\n", (long) getpid()); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1685 | fclose(f); |
| 1686 | } |
| 1687 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1688 | |
Damien Miller | a1f6840 | 2006-08-19 00:31:39 +1000 | [diff] [blame] | 1689 | /* Accept a connection and return in a forked child */ |
| 1690 | server_accept_loop(&sock_in, &sock_out, |
| 1691 | &newsock, config_s); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1692 | } |
| 1693 | |
| 1694 | /* This is the child processing a new connection. */ |
Damien Miller | 57aae98 | 2004-03-08 23:11:25 +1100 | [diff] [blame] | 1695 | setproctitle("%s", "[accepted]"); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1696 | |
Darren Tucker | 6832b83 | 2004-08-12 22:36:51 +1000 | [diff] [blame] | 1697 | /* |
| 1698 | * Create a new session and process group since the 4.4BSD |
| 1699 | * setlogin() affects the entire process group. We don't |
| 1700 | * want the child to be able to affect the parent. |
| 1701 | */ |
| 1702 | #if !defined(SSHD_ACQUIRES_CTTY) |
| 1703 | /* |
| 1704 | * If setsid is called, on some platforms sshd will later acquire a |
| 1705 | * controlling terminal which will result in "could not set |
| 1706 | * controlling tty" errors. |
| 1707 | */ |
| 1708 | if (!debug_flag && !inetd_flag && setsid() < 0) |
| 1709 | error("setsid: %.100s", strerror(errno)); |
| 1710 | #endif |
| 1711 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1712 | if (rexec_flag) { |
| 1713 | int fd; |
| 1714 | |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1715 | debug("rexec start in %d out %d newsock %d pipe %d sock %d", |
| 1716 | sock_in, sock_out, newsock, startup_pipe, config_s[0]); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1717 | dup2(newsock, STDIN_FILENO); |
| 1718 | dup2(STDIN_FILENO, STDOUT_FILENO); |
| 1719 | if (startup_pipe == -1) |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1720 | close(REEXEC_STARTUP_PIPE_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1721 | else |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1722 | dup2(startup_pipe, REEXEC_STARTUP_PIPE_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1723 | |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1724 | dup2(config_s[1], REEXEC_CONFIG_PASS_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1725 | close(config_s[1]); |
Darren Tucker | d883593 | 2004-08-12 22:42:29 +1000 | [diff] [blame] | 1726 | if (startup_pipe != -1) |
| 1727 | close(startup_pipe); |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1728 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1729 | execv(rexec_argv[0], rexec_argv); |
| 1730 | |
| 1731 | /* Reexec has failed, fall back and continue */ |
| 1732 | error("rexec of %s failed: %s", rexec_argv[0], strerror(errno)); |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1733 | recv_rexec_state(REEXEC_CONFIG_PASS_FD, NULL); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1734 | log_init(__progname, options.log_level, |
| 1735 | options.log_facility, log_stderr); |
| 1736 | |
| 1737 | /* Clean up fds */ |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1738 | startup_pipe = REEXEC_STARTUP_PIPE_FD; |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1739 | close(config_s[1]); |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1740 | close(REEXEC_CONFIG_PASS_FD); |
| 1741 | newsock = sock_out = sock_in = dup(STDIN_FILENO); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1742 | if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { |
| 1743 | dup2(fd, STDIN_FILENO); |
| 1744 | dup2(fd, STDOUT_FILENO); |
| 1745 | if (fd > STDERR_FILENO) |
| 1746 | close(fd); |
| 1747 | } |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1748 | debug("rexec cleanup in %d out %d newsock %d pipe %d sock %d", |
| 1749 | sock_in, sock_out, newsock, startup_pipe, config_s[0]); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1750 | } |
| 1751 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1752 | /* |
| 1753 | * Disable the key regeneration alarm. We will not regenerate the |
| 1754 | * key since we are no longer in a position to give it to anyone. We |
| 1755 | * will not restart on SIGHUP since it no longer makes sense. |
| 1756 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1757 | alarm(0); |
| 1758 | signal(SIGALRM, SIG_DFL); |
| 1759 | signal(SIGHUP, SIG_DFL); |
| 1760 | signal(SIGTERM, SIG_DFL); |
| 1761 | signal(SIGQUIT, SIG_DFL); |
| 1762 | signal(SIGCHLD, SIG_DFL); |
Damien Miller | 4e0f5e1 | 2000-08-29 11:05:50 +1100 | [diff] [blame] | 1763 | signal(SIGINT, SIG_DFL); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1764 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1765 | /* |
| 1766 | * Register our connection. This turns encryption off because we do |
| 1767 | * not have a key. |
| 1768 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1769 | packet_set_connection(sock_in, sock_out); |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 1770 | packet_set_server(); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1771 | |
Damien Miller | 4f1d6b2 | 2005-05-26 11:59:32 +1000 | [diff] [blame] | 1772 | /* Set SO_KEEPALIVE if requested. */ |
| 1773 | if (options.tcp_keep_alive && packet_connection_is_on_socket() && |
| 1774 | setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) < 0) |
| 1775 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); |
| 1776 | |
Damien Miller | 677257f | 2005-06-17 12:55:03 +1000 | [diff] [blame] | 1777 | if ((remote_port = get_remote_port()) < 0) { |
| 1778 | debug("get_remote_port failed"); |
| 1779 | cleanup_exit(255); |
| 1780 | } |
Damien Miller | 4d3fd54 | 2005-11-05 15:13:24 +1100 | [diff] [blame] | 1781 | |
| 1782 | /* |
| 1783 | * We use get_canonical_hostname with usedns = 0 instead of |
| 1784 | * get_remote_ipaddr here so IP options will be checked. |
| 1785 | */ |
Damien Miller | eb13e55 | 2006-06-13 13:03:53 +1000 | [diff] [blame] | 1786 | (void) get_canonical_hostname(0); |
| 1787 | /* |
| 1788 | * The rest of the code depends on the fact that |
| 1789 | * get_remote_ipaddr() caches the remote ip, even if |
| 1790 | * the socket goes away. |
| 1791 | */ |
| 1792 | remote_ip = get_remote_ipaddr(); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1793 | |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 1794 | #ifdef SSH_AUDIT_EVENTS |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 1795 | audit_connection_from(remote_ip, remote_port); |
| 1796 | #endif |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1797 | #ifdef LIBWRAP |
Darren Tucker | 1f1e17b | 2008-02-28 23:20:48 +1100 | [diff] [blame] | 1798 | allow_severity = options.log_facility|LOG_INFO; |
| 1799 | deny_severity = options.log_facility|LOG_WARNING; |
Damien Miller | 6a4a4b9 | 2001-11-12 11:07:11 +1100 | [diff] [blame] | 1800 | /* Check whether logins are denied from this host. */ |
Darren Tucker | 586b0b9 | 2004-06-25 13:34:31 +1000 | [diff] [blame] | 1801 | if (packet_connection_is_on_socket()) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1802 | struct request_info req; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1803 | |
Ben Lindstrom | ce89dac | 2001-09-12 16:58:04 +0000 | [diff] [blame] | 1804 | request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1805 | fromhost(&req); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1806 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1807 | if (!hosts_access(&req)) { |
Damien Miller | 6a4a4b9 | 2001-11-12 11:07:11 +1100 | [diff] [blame] | 1808 | debug("Connection refused by tcp wrapper"); |
Ben Lindstrom | 7de696e | 2001-03-29 00:45:12 +0000 | [diff] [blame] | 1809 | refuse(&req); |
Damien Miller | 6a4a4b9 | 2001-11-12 11:07:11 +1100 | [diff] [blame] | 1810 | /* NOTREACHED */ |
| 1811 | fatal("libwrap refuse returns"); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1812 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1813 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1814 | #endif /* LIBWRAP */ |
Damien Miller | 6a4a4b9 | 2001-11-12 11:07:11 +1100 | [diff] [blame] | 1815 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1816 | /* Log the connection. */ |
| 1817 | verbose("Connection from %.500s port %d", remote_ip, remote_port); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1818 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1819 | /* |
Damien Miller | 788f212 | 2005-11-05 15:14:59 +1100 | [diff] [blame] | 1820 | * We don't want to listen forever unless the other side |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1821 | * successfully authenticates itself. So we set up an alarm which is |
| 1822 | * cleared after successful authentication. A limit of zero |
Damien Miller | 788f212 | 2005-11-05 15:14:59 +1100 | [diff] [blame] | 1823 | * indicates no limit. Note that we don't set the alarm in debugging |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1824 | * mode; it is just annoying to have the server exit just when you |
| 1825 | * are about to discover the bug. |
| 1826 | */ |
Ben Lindstrom | 5ade9ab | 2003-08-25 01:16:21 +0000 | [diff] [blame] | 1827 | signal(SIGALRM, grace_alarm_handler); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1828 | if (!debug_flag) |
| 1829 | alarm(options.login_grace_time); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1830 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 1831 | sshd_exchange_identification(sock_in, sock_out); |
Darren Tucker | ec960f2 | 2003-08-13 20:37:05 +1000 | [diff] [blame] | 1832 | |
Darren Tucker | 5891116 | 2008-01-01 20:33:09 +1100 | [diff] [blame] | 1833 | /* In inetd mode, generate ephemeral key only for proto 1 connections */ |
| 1834 | if (!compat20 && inetd_flag && sensitive_data.server_key == NULL) |
| 1835 | generate_ephemeral_server_key(); |
| 1836 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1837 | packet_set_nonblocking(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1838 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1839 | /* allocate authentication context */ |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1840 | authctxt = xcalloc(1, sizeof(*authctxt)); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1841 | |
Darren Tucker | f3bb434 | 2005-03-31 21:39:25 +1000 | [diff] [blame] | 1842 | authctxt->loginmsg = &loginmsg; |
| 1843 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1844 | /* XXX global for cleanup, access from other modules */ |
| 1845 | the_authctxt = authctxt; |
| 1846 | |
Darren Tucker | 5c14c73 | 2005-01-24 21:55:49 +1100 | [diff] [blame] | 1847 | /* prepare buffer to collect messages to display to user after login */ |
| 1848 | buffer_init(&loginmsg); |
| 1849 | |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1850 | if (use_privsep) |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1851 | if (privsep_preauth(authctxt) == 1) |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1852 | goto authenticated; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1853 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1854 | /* perform the key exchange */ |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1855 | /* authenticate user and start session */ |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 1856 | if (compat20) { |
| 1857 | do_ssh2_kex(); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1858 | do_authentication2(authctxt); |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 1859 | } else { |
| 1860 | do_ssh1_kex(); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1861 | do_authentication(authctxt); |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 1862 | } |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1863 | /* |
| 1864 | * If we use privilege separation, the unprivileged child transfers |
| 1865 | * the current keystate and exits |
| 1866 | */ |
| 1867 | if (use_privsep) { |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 1868 | mm_send_keystate(pmonitor); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1869 | exit(0); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1870 | } |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1871 | |
| 1872 | authenticated: |
Damien Miller | 7bff1a9 | 2005-12-24 14:59:12 +1100 | [diff] [blame] | 1873 | /* |
| 1874 | * Cancel the alarm we set to limit the time taken for |
| 1875 | * authentication. |
| 1876 | */ |
| 1877 | alarm(0); |
| 1878 | signal(SIGALRM, SIG_DFL); |
Damien Miller | 3f8123c | 2006-08-19 00:32:46 +1000 | [diff] [blame] | 1879 | authctxt->authenticated = 1; |
Damien Miller | 7bff1a9 | 2005-12-24 14:59:12 +1100 | [diff] [blame] | 1880 | if (startup_pipe != -1) { |
| 1881 | close(startup_pipe); |
| 1882 | startup_pipe = -1; |
| 1883 | } |
| 1884 | |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 1885 | #ifdef SSH_AUDIT_EVENTS |
| 1886 | audit_event(SSH_AUTH_SUCCESS); |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 1887 | #endif |
| 1888 | |
Darren Tucker | 52358d6 | 2008-03-11 22:58:25 +1100 | [diff] [blame] | 1889 | #ifdef GSSAPI |
| 1890 | if (options.gss_authentication) { |
| 1891 | temporarily_use_uid(authctxt->pw); |
| 1892 | ssh_gssapi_storecreds(); |
| 1893 | restore_uid(); |
| 1894 | } |
| 1895 | #endif |
| 1896 | #ifdef USE_PAM |
| 1897 | if (options.use_pam) { |
| 1898 | do_pam_setcred(1); |
| 1899 | do_pam_session(); |
| 1900 | } |
| 1901 | #endif |
| 1902 | |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 1903 | /* |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1904 | * In privilege separation, we fork another child and prepare |
| 1905 | * file descriptor passing. |
| 1906 | */ |
| 1907 | if (use_privsep) { |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1908 | privsep_postauth(authctxt); |
| 1909 | /* the monitor process [priv] will not return */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1910 | if (!compat20) |
| 1911 | destroy_sensitive_data(); |
| 1912 | } |
Ben Lindstrom | 73ab9ba | 2002-03-22 01:27:35 +0000 | [diff] [blame] | 1913 | |
Darren Tucker | 3fc464e | 2008-06-13 06:42:45 +1000 | [diff] [blame] | 1914 | packet_set_timeout(options.client_alive_interval, |
| 1915 | options.client_alive_count_max); |
| 1916 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1917 | /* Start session. */ |
Ben Lindstrom | 73ab9ba | 2002-03-22 01:27:35 +0000 | [diff] [blame] | 1918 | do_authenticated(authctxt); |
| 1919 | |
Damien Miller | 3a5b023 | 2002-03-13 13:19:42 +1100 | [diff] [blame] | 1920 | /* The connection has been terminated. */ |
| 1921 | verbose("Closing connection to %.100s", remote_ip); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1922 | |
Damien Miller | beb4ba5 | 1999-12-28 15:09:35 +1100 | [diff] [blame] | 1923 | #ifdef USE_PAM |
Damien Miller | 4e448a3 | 2003-05-14 15:11:48 +1000 | [diff] [blame] | 1924 | if (options.use_pam) |
| 1925 | finish_pam(); |
Damien Miller | beb4ba5 | 1999-12-28 15:09:35 +1100 | [diff] [blame] | 1926 | #endif /* USE_PAM */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1927 | |
Darren Tucker | 2b59a6d | 2005-03-06 22:38:51 +1100 | [diff] [blame] | 1928 | #ifdef SSH_AUDIT_EVENTS |
| 1929 | PRIVSEP(audit_event(SSH_CONNECTION_CLOSE)); |
| 1930 | #endif |
| 1931 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1932 | packet_close(); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1933 | |
| 1934 | if (use_privsep) |
| 1935 | mm_terminate(); |
| 1936 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1937 | exit(0); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1938 | } |
| 1939 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1940 | /* |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1941 | * Decrypt session_key_int using our private server key and private host key |
| 1942 | * (key with larger modulus first). |
| 1943 | */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1944 | int |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1945 | ssh1_session_key(BIGNUM *session_key_int) |
| 1946 | { |
| 1947 | int rsafail = 0; |
| 1948 | |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1949 | if (BN_cmp(sensitive_data.server_key->rsa->n, |
| 1950 | sensitive_data.ssh1_host_key->rsa->n) > 0) { |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1951 | /* Server key has bigger modulus. */ |
| 1952 | if (BN_num_bits(sensitive_data.server_key->rsa->n) < |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1953 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + |
| 1954 | SSH_KEY_BITS_RESERVED) { |
| 1955 | fatal("do_connection: %s: " |
| 1956 | "server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d", |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1957 | get_remote_ipaddr(), |
| 1958 | BN_num_bits(sensitive_data.server_key->rsa->n), |
| 1959 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), |
| 1960 | SSH_KEY_BITS_RESERVED); |
| 1961 | } |
| 1962 | if (rsa_private_decrypt(session_key_int, session_key_int, |
| 1963 | sensitive_data.server_key->rsa) <= 0) |
| 1964 | rsafail++; |
| 1965 | if (rsa_private_decrypt(session_key_int, session_key_int, |
| 1966 | sensitive_data.ssh1_host_key->rsa) <= 0) |
| 1967 | rsafail++; |
| 1968 | } else { |
| 1969 | /* Host key has bigger modulus (or they are equal). */ |
| 1970 | if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) < |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1971 | BN_num_bits(sensitive_data.server_key->rsa->n) + |
| 1972 | SSH_KEY_BITS_RESERVED) { |
| 1973 | fatal("do_connection: %s: " |
| 1974 | "host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d", |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1975 | get_remote_ipaddr(), |
| 1976 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), |
| 1977 | BN_num_bits(sensitive_data.server_key->rsa->n), |
| 1978 | SSH_KEY_BITS_RESERVED); |
| 1979 | } |
| 1980 | if (rsa_private_decrypt(session_key_int, session_key_int, |
| 1981 | sensitive_data.ssh1_host_key->rsa) < 0) |
| 1982 | rsafail++; |
| 1983 | if (rsa_private_decrypt(session_key_int, session_key_int, |
| 1984 | sensitive_data.server_key->rsa) < 0) |
| 1985 | rsafail++; |
| 1986 | } |
| 1987 | return (rsafail); |
| 1988 | } |
| 1989 | /* |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1990 | * SSH1 key exchange |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1991 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 1992 | static void |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1993 | do_ssh1_kex(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1994 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1995 | int i, len; |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 1996 | int rsafail = 0; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1997 | BIGNUM *session_key_int; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1998 | u_char session_key[SSH_SESSION_KEY_LENGTH]; |
| 1999 | u_char cookie[8]; |
| 2000 | u_int cipher_type, auth_mask, protocol_flags; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2001 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 2002 | /* |
| 2003 | * Generate check bytes that the client must send back in the user |
| 2004 | * packet in order for it to be accepted; this is used to defy ip |
| 2005 | * spoofing attacks. Note that this only works against somebody |
| 2006 | * doing IP spoofing from a remote machine; any machine on the local |
| 2007 | * network can still see outgoing packets and catch the random |
| 2008 | * cookie. This only affects rhosts authentication, and this is one |
| 2009 | * of the reasons why it is inherently insecure. |
| 2010 | */ |
Damien Miller | 354c48c | 2008-05-19 14:50:00 +1000 | [diff] [blame] | 2011 | arc4random_buf(cookie, sizeof(cookie)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2012 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 2013 | /* |
| 2014 | * Send our public key. We include in the packet 64 bits of random |
| 2015 | * data that must be matched in the reply in order to prevent IP |
| 2016 | * spoofing. |
| 2017 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2018 | packet_start(SSH_SMSG_PUBLIC_KEY); |
| 2019 | for (i = 0; i < 8; i++) |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 2020 | packet_put_char(cookie[i]); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2021 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2022 | /* Store our public server RSA key. */ |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 2023 | packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n)); |
| 2024 | packet_put_bignum(sensitive_data.server_key->rsa->e); |
| 2025 | packet_put_bignum(sensitive_data.server_key->rsa->n); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2026 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2027 | /* Store our public host RSA key. */ |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 2028 | packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); |
| 2029 | packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e); |
| 2030 | packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2031 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2032 | /* Put protocol flags. */ |
| 2033 | packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2034 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2035 | /* Declare which ciphers we support. */ |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 2036 | packet_put_int(cipher_mask_ssh1(0)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2037 | |
| 2038 | /* Declare supported authentication types. */ |
| 2039 | auth_mask = 0; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2040 | if (options.rhosts_rsa_authentication) |
| 2041 | auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA; |
| 2042 | if (options.rsa_authentication) |
| 2043 | auth_mask |= 1 << SSH_AUTH_RSA; |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 2044 | if (options.challenge_response_authentication == 1) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2045 | auth_mask |= 1 << SSH_AUTH_TIS; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2046 | if (options.password_authentication) |
| 2047 | auth_mask |= 1 << SSH_AUTH_PASSWORD; |
| 2048 | packet_put_int(auth_mask); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2049 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2050 | /* Send the packet and wait for it to be sent. */ |
| 2051 | packet_send(); |
| 2052 | packet_write_wait(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2053 | |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 2054 | debug("Sent %d bit server key and %d bit host key.", |
| 2055 | BN_num_bits(sensitive_data.server_key->rsa->n), |
| 2056 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2057 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2058 | /* Read clients reply (cipher type and session key). */ |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 2059 | packet_read_expect(SSH_CMSG_SESSION_KEY); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2060 | |
Damien Miller | 50945fa | 1999-12-09 10:31:37 +1100 | [diff] [blame] | 2061 | /* Get cipher type and check whether we accept this. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2062 | cipher_type = packet_get_char(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2063 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 2064 | if (!(cipher_mask_ssh1(0) & (1 << cipher_type))) |
Damien Miller | 50945fa | 1999-12-09 10:31:37 +1100 | [diff] [blame] | 2065 | packet_disconnect("Warning: client selects unsupported cipher."); |
| 2066 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2067 | /* Get check bytes from the packet. These must match those we |
| 2068 | sent earlier with the public key packet. */ |
| 2069 | for (i = 0; i < 8; i++) |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 2070 | if (cookie[i] != packet_get_char()) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2071 | packet_disconnect("IP Spoofing check bytes do not match."); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2072 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2073 | debug("Encryption type: %.200s", cipher_name(cipher_type)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2074 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2075 | /* Get the encrypted integer. */ |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 2076 | if ((session_key_int = BN_new()) == NULL) |
| 2077 | fatal("do_ssh1_kex: BN_new failed"); |
Damien Miller | d432ccf | 2002-01-22 23:14:44 +1100 | [diff] [blame] | 2078 | packet_get_bignum(session_key_int); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2079 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2080 | protocol_flags = packet_get_int(); |
| 2081 | packet_set_protocol_flags(protocol_flags); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 2082 | packet_check_eom(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2083 | |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 2084 | /* Decrypt session_key_int using host/server keys */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 2085 | rsafail = PRIVSEP(ssh1_session_key(session_key_int)); |
| 2086 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 2087 | /* |
| 2088 | * Extract session key from the decrypted integer. The key is in the |
| 2089 | * least significant 256 bits of the integer; the first byte of the |
| 2090 | * key is in the highest bits. |
| 2091 | */ |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 2092 | if (!rsafail) { |
Darren Tucker | 0bc8557 | 2006-11-07 23:14:41 +1100 | [diff] [blame] | 2093 | (void) BN_mask_bits(session_key_int, sizeof(session_key) * 8); |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 2094 | len = BN_num_bytes(session_key_int); |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 2095 | if (len < 0 || (u_int)len > sizeof(session_key)) { |
Darren Tucker | 0bc8557 | 2006-11-07 23:14:41 +1100 | [diff] [blame] | 2096 | error("do_ssh1_kex: bad session key len from %s: " |
Ben Lindstrom | 31ca54a | 2001-02-09 02:11:24 +0000 | [diff] [blame] | 2097 | "session_key_int %d > sizeof(session_key) %lu", |
| 2098 | get_remote_ipaddr(), len, (u_long)sizeof(session_key)); |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 2099 | rsafail++; |
| 2100 | } else { |
| 2101 | memset(session_key, 0, sizeof(session_key)); |
| 2102 | BN_bn2bin(session_key_int, |
| 2103 | session_key + sizeof(session_key) - len); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 2104 | |
Darren Tucker | e14e005 | 2004-05-13 16:30:44 +1000 | [diff] [blame] | 2105 | derive_ssh1_session_id( |
Darren Tucker | fc95970 | 2004-07-17 16:12:08 +1000 | [diff] [blame] | 2106 | sensitive_data.ssh1_host_key->rsa->n, |
Darren Tucker | e14e005 | 2004-05-13 16:30:44 +1000 | [diff] [blame] | 2107 | sensitive_data.server_key->rsa->n, |
| 2108 | cookie, session_id); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 2109 | /* |
| 2110 | * Xor the first 16 bytes of the session key with the |
| 2111 | * session id. |
| 2112 | */ |
| 2113 | for (i = 0; i < 16; i++) |
| 2114 | session_key[i] ^= session_id[i]; |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 2115 | } |
| 2116 | } |
| 2117 | if (rsafail) { |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 2118 | int bytes = BN_num_bytes(session_key_int); |
Ben Lindstrom | 13c5d3b | 2002-02-26 18:00:48 +0000 | [diff] [blame] | 2119 | u_char *buf = xmalloc(bytes); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 2120 | MD5_CTX md; |
| 2121 | |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 2122 | logit("do_connection: generating a fake encryption key"); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 2123 | BN_bn2bin(session_key_int, buf); |
| 2124 | MD5_Init(&md); |
| 2125 | MD5_Update(&md, buf, bytes); |
| 2126 | MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); |
| 2127 | MD5_Final(session_key, &md); |
| 2128 | MD5_Init(&md); |
| 2129 | MD5_Update(&md, session_key, 16); |
| 2130 | MD5_Update(&md, buf, bytes); |
| 2131 | MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); |
| 2132 | MD5_Final(session_key + 16, &md); |
| 2133 | memset(buf, 0, bytes); |
| 2134 | xfree(buf); |
Ben Lindstrom | 941ac82 | 2001-03-05 06:25:23 +0000 | [diff] [blame] | 2135 | for (i = 0; i < 16; i++) |
| 2136 | session_id[i] = session_key[i] ^ session_key[i + 16]; |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 2137 | } |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 2138 | /* Destroy the private and public keys. No longer. */ |
Damien Miller | 3a5b023 | 2002-03-13 13:19:42 +1100 | [diff] [blame] | 2139 | destroy_sensitive_data(); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 2140 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 2141 | if (use_privsep) |
| 2142 | mm_ssh1_session_id(session_id); |
| 2143 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 2144 | /* Destroy the decrypted integer. It is no longer needed. */ |
| 2145 | BN_clear_free(session_key_int); |
| 2146 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2147 | /* Set the session key. From this on all communications will be encrypted. */ |
| 2148 | packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2149 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2150 | /* Destroy our copy of the session key. It is no longer needed. */ |
| 2151 | memset(session_key, 0, sizeof(session_key)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2152 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2153 | debug("Received session key; encryption turned on."); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2154 | |
Ben Lindstrom | f666fec | 2002-06-06 19:51:58 +0000 | [diff] [blame] | 2155 | /* Send an acknowledgment packet. Note that this packet is sent encrypted. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2156 | packet_start(SSH_SMSG_SUCCESS); |
| 2157 | packet_send(); |
| 2158 | packet_write_wait(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2159 | } |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2160 | |
| 2161 | /* |
| 2162 | * SSH2 key exchange: diffie-hellman-group1-sha1 |
| 2163 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 2164 | static void |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 2165 | do_ssh2_kex(void) |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2166 | { |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2167 | Kex *kex; |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2168 | |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 2169 | if (options.ciphers != NULL) { |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 2170 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 2171 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; |
| 2172 | } |
Damien Miller | a0ff466 | 2001-03-30 10:49:35 +1000 | [diff] [blame] | 2173 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
| 2174 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); |
| 2175 | myproposal[PROPOSAL_ENC_ALGS_STOC] = |
| 2176 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); |
| 2177 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 2178 | if (options.macs != NULL) { |
| 2179 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = |
| 2180 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; |
| 2181 | } |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 2182 | if (options.compression == COMP_NONE) { |
Ben Lindstrom | 23e0f66 | 2002-06-21 01:09:47 +0000 | [diff] [blame] | 2183 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
| 2184 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 2185 | } else if (options.compression == COMP_DELAYED) { |
| 2186 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
| 2187 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com"; |
Ben Lindstrom | 23e0f66 | 2002-06-21 01:09:47 +0000 | [diff] [blame] | 2188 | } |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 2189 | |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 2190 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types(); |
| 2191 | |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 2192 | /* start key exchange */ |
Ben Lindstrom | 238abf6 | 2001-04-04 17:52:53 +0000 | [diff] [blame] | 2193 | kex = kex_setup(myproposal); |
Damien Miller | 8e7fb33 | 2003-02-24 12:03:03 +1100 | [diff] [blame] | 2194 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; |
Damien Miller | f675fc4 | 2004-06-15 10:30:09 +1000 | [diff] [blame] | 2195 | kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; |
Damien Miller | 8e7fb33 | 2003-02-24 12:03:03 +1100 | [diff] [blame] | 2196 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; |
Damien Miller | a63128d | 2006-03-15 12:08:28 +1100 | [diff] [blame] | 2197 | kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 2198 | kex->server = 1; |
| 2199 | kex->client_version_string=client_version_string; |
| 2200 | kex->server_version_string=server_version_string; |
| 2201 | kex->load_host_key=&get_hostkey_by_type; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 2202 | kex->host_key_index=&get_hostkey_index; |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2203 | |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 2204 | xxx_kex = kex; |
| 2205 | |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 2206 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 2207 | |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 2208 | session_id2 = kex->session_id; |
| 2209 | session_id2_len = kex->session_id_len; |
| 2210 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 2211 | #ifdef DEBUG_KEXDH |
| 2212 | /* send 1st encrypted/maced/compressed message */ |
| 2213 | packet_start(SSH2_MSG_IGNORE); |
| 2214 | packet_put_cstring("markus"); |
| 2215 | packet_send(); |
| 2216 | packet_write_wait(); |
| 2217 | #endif |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 2218 | debug("KEX done"); |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2219 | } |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 2220 | |
| 2221 | /* server specific fatal cleanup */ |
| 2222 | void |
| 2223 | cleanup_exit(int i) |
| 2224 | { |
| 2225 | if (the_authctxt) |
| 2226 | do_cleanup(the_authctxt); |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 2227 | #ifdef SSH_AUDIT_EVENTS |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 2228 | /* done after do_cleanup so it can cancel the PAM auth 'thread' */ |
| 2229 | if (!use_privsep || mm_is_monitor()) |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 2230 | audit_event(SSH_CONNECTION_ABANDON); |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 2231 | #endif |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 2232 | _exit(i); |
| 2233 | } |