Darren Tucker | 1a3d6e7 | 2006-08-05 18:46:47 +1000 | [diff] [blame] | 1 | /* $OpenBSD: sshd.c,v 1.344 2006/08/05 07:52:52 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 | 9cf6d07 | 2006-03-15 11:29:24 +1100 | [diff] [blame] | 57 | #include <sys/wait.h> |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 58 | |
Darren Tucker | 3997249 | 2006-07-12 22:22:46 +1000 | [diff] [blame] | 59 | #include <errno.h> |
Damien Miller | 57cf638 | 2006-07-10 21:13:46 +1000 | [diff] [blame] | 60 | #include <fcntl.h> |
Damien Miller | b8fe89c | 2006-07-24 14:51:00 +1000 | [diff] [blame] | 61 | #include <netdb.h> |
Damien Miller | 6645e7a | 2006-03-15 14:42:54 +1100 | [diff] [blame] | 62 | #ifdef HAVE_PATHS_H |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 63 | #include <paths.h> |
Damien Miller | 6645e7a | 2006-03-15 14:42:54 +1100 | [diff] [blame] | 64 | #endif |
Damien Miller | a1738e4 | 2006-07-10 21:33:04 +1000 | [diff] [blame] | 65 | #include <grp.h> |
Damien Miller | 9f2abc4 | 2006-07-10 20:53:08 +1000 | [diff] [blame] | 66 | #include <pwd.h> |
Damien Miller | 6ff3cad | 2006-03-15 11:52:09 +1100 | [diff] [blame] | 67 | #include <signal.h> |
Damien Miller | a7a73ee | 2006-08-05 11:37:59 +1000 | [diff] [blame] | 68 | #include <stdio.h> |
Damien Miller | e7a1e5c | 2006-08-05 11:34:19 +1000 | [diff] [blame] | 69 | #include <stdlib.h> |
Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 70 | #include <string.h> |
Damien Miller | 75bb664 | 2006-08-05 14:07:20 +1000 | [diff] [blame] | 71 | #include <unistd.h> |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 72 | |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 73 | #include <openssl/dh.h> |
| 74 | #include <openssl/bn.h> |
Damien Miller | 6a47f30 | 2002-02-13 13:55:06 +1100 | [diff] [blame] | 75 | #include <openssl/md5.h> |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 76 | #include <openssl/rand.h> |
Kevin Steves | 0ea1d9d | 2002-04-25 18:17:04 +0000 | [diff] [blame] | 77 | #ifdef HAVE_SECUREWARE |
| 78 | #include <sys/security.h> |
| 79 | #include <prot.h> |
| 80 | #endif |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 81 | |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 82 | #include "xmalloc.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 83 | #include "ssh.h" |
| 84 | #include "ssh1.h" |
| 85 | #include "ssh2.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 86 | #include "rsa.h" |
Ben Lindstrom | d95c09c | 2001-02-18 19:13:33 +0000 | [diff] [blame] | 87 | #include "sshpty.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 88 | #include "packet.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 89 | #include "log.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 90 | #include "buffer.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 91 | #include "servconf.h" |
| 92 | #include "uidswap.h" |
| 93 | #include "compat.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 94 | #include "cipher.h" |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 95 | #include "key.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 96 | #include "kex.h" |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 97 | #include "dh.h" |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 98 | #include "myproposal.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 99 | #include "authfile.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 100 | #include "pathnames.h" |
| 101 | #include "atomicio.h" |
| 102 | #include "canohost.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 103 | #include "hostfile.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 104 | #include "auth.h" |
| 105 | #include "misc.h" |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 106 | #include "msg.h" |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 107 | #include "dispatch.h" |
Ben Lindstrom | 1bae404 | 2001-10-03 17:46:39 +0000 | [diff] [blame] | 108 | #include "channels.h" |
Ben Lindstrom | 73ab9ba | 2002-03-22 01:27:35 +0000 | [diff] [blame] | 109 | #include "session.h" |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 110 | #include "monitor_mm.h" |
| 111 | #include "monitor.h" |
Damien Miller | d783435 | 2006-08-05 12:39:39 +1000 | [diff] [blame] | 112 | #ifdef GSSAPI |
| 113 | #include "ssh-gss.h" |
| 114 | #endif |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 115 | #include "monitor_wrap.h" |
| 116 | #include "monitor_fdpass.h" |
Damien Miller | b757677 | 2006-07-10 20:23:39 +1000 | [diff] [blame] | 117 | #include "version.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 118 | |
| 119 | #ifdef LIBWRAP |
| 120 | #include <tcpd.h> |
| 121 | #include <syslog.h> |
| 122 | int allow_severity = LOG_INFO; |
| 123 | int deny_severity = LOG_WARNING; |
| 124 | #endif /* LIBWRAP */ |
| 125 | |
| 126 | #ifndef O_NOCTTY |
| 127 | #define O_NOCTTY 0 |
| 128 | #endif |
| 129 | |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 130 | /* Re-exec fds */ |
| 131 | #define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1) |
| 132 | #define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2) |
| 133 | #define REEXEC_CONFIG_PASS_FD (STDERR_FILENO + 3) |
| 134 | #define REEXEC_MIN_FREE_FD (STDERR_FILENO + 4) |
| 135 | |
Ben Lindstrom | 49a79c0 | 2000-11-17 03:47:20 +0000 | [diff] [blame] | 136 | extern char *__progname; |
Ben Lindstrom | 49a79c0 | 2000-11-17 03:47:20 +0000 | [diff] [blame] | 137 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 138 | /* Server configuration options. */ |
| 139 | ServerOptions options; |
| 140 | |
| 141 | /* Name of the server configuration file. */ |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 142 | char *config_file_name = _PATH_SERVER_CONFIG_FILE; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 143 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 144 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 145 | * Debug mode flag. This can be set on the command line. If debug |
| 146 | * mode is enabled, extra debugging output will be sent to the system |
| 147 | * log, the daemon will not go to background, and will exit after processing |
| 148 | * the first connection. |
| 149 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 150 | int debug_flag = 0; |
| 151 | |
Ben Lindstrom | 794325a | 2001-08-06 21:09:07 +0000 | [diff] [blame] | 152 | /* Flag indicating that the daemon should only test the configuration and keys. */ |
| 153 | int test_flag = 0; |
| 154 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 155 | /* Flag indicating that the daemon is being started from inetd. */ |
| 156 | int inetd_flag = 0; |
| 157 | |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 158 | /* Flag indicating that sshd should not detach and become a daemon. */ |
| 159 | int no_daemon_flag = 0; |
| 160 | |
Damien Miller | 5ce662a | 1999-11-11 17:57:39 +1100 | [diff] [blame] | 161 | /* debug goes to stderr unless inetd_flag is set */ |
| 162 | int log_stderr = 0; |
| 163 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 164 | /* Saved arguments to main(). */ |
| 165 | char **saved_argv; |
Damien Miller | b8c656e | 2000-06-28 15:22:41 +1000 | [diff] [blame] | 166 | int saved_argc; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 167 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 168 | /* re-exec */ |
| 169 | int rexeced_flag = 0; |
| 170 | int rexec_flag = 1; |
| 171 | int rexec_argc = 0; |
| 172 | char **rexec_argv; |
| 173 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 174 | /* |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 175 | * The sockets that the server is listening; this is used in the SIGHUP |
| 176 | * signal handler. |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 177 | */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 178 | #define MAX_LISTEN_SOCKS 16 |
| 179 | int listen_socks[MAX_LISTEN_SOCKS]; |
| 180 | int num_listen_socks = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 181 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 182 | /* |
| 183 | * the client's version string, passed by sshd2 in compat mode. if != NULL, |
| 184 | * sshd will skip the version-number exchange |
| 185 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 186 | char *client_version_string = NULL; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 187 | char *server_version_string = NULL; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 188 | |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 189 | /* for rekeying XXX fixme */ |
| 190 | Kex *xxx_kex; |
| 191 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 192 | /* |
| 193 | * Any really sensitive data in the application is contained in this |
| 194 | * structure. The idea is that this structure could be locked into memory so |
| 195 | * that the pages do not get written into swap. However, there are some |
| 196 | * problems. The private key contains BIGNUMs, and we do not (in principle) |
| 197 | * have access to the internals of them, and locking just the structure is |
| 198 | * not very useful. Currently, memory locking is not implemented. |
| 199 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 200 | struct { |
Ben Lindstrom | ca42d5f | 2001-03-09 18:25:32 +0000 | [diff] [blame] | 201 | Key *server_key; /* ephemeral server key */ |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 202 | Key *ssh1_host_key; /* ssh1 host key */ |
| 203 | Key **host_keys; /* all private host keys */ |
| 204 | int have_ssh1_key; |
| 205 | int have_ssh2_key; |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 206 | u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 207 | } sensitive_data; |
| 208 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 209 | /* |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 210 | * Flag indicating whether the RSA server key needs to be regenerated. |
| 211 | * 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] | 212 | */ |
Ben Lindstrom | 5e71c54 | 2001-12-06 16:48:14 +0000 | [diff] [blame] | 213 | static volatile sig_atomic_t key_do_regen = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 214 | |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 215 | /* This is set to true when a signal is received. */ |
Ben Lindstrom | 5e71c54 | 2001-12-06 16:48:14 +0000 | [diff] [blame] | 216 | static volatile sig_atomic_t received_sighup = 0; |
| 217 | static volatile sig_atomic_t received_sigterm = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 218 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 219 | /* session identifier, used by RSA-auth */ |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 220 | u_char session_id[16]; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 221 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 222 | /* same for ssh2 */ |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 223 | u_char *session_id2 = NULL; |
Darren Tucker | 502d384 | 2003-06-28 12:38:01 +1000 | [diff] [blame] | 224 | u_int session_id2_len = 0; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 225 | |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 226 | /* record remote hostname or ip */ |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 227 | u_int utmp_len = MAXHOSTNAMELEN; |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 228 | |
Ben Lindstrom | d84df98 | 2001-12-06 16:35:40 +0000 | [diff] [blame] | 229 | /* options.max_startup sized array of fd ints */ |
| 230 | int *startup_pipes = NULL; |
| 231 | int startup_pipe; /* in child */ |
| 232 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 233 | /* variables used for privilege separation */ |
Darren Tucker | 4515047 | 2006-07-12 22:34:17 +1000 | [diff] [blame] | 234 | int use_privsep = -1; |
Darren Tucker | a8be9e2 | 2004-02-06 16:40:27 +1100 | [diff] [blame] | 235 | struct monitor *pmonitor = NULL; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 236 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 237 | /* global authentication context */ |
| 238 | Authctxt *the_authctxt = NULL; |
| 239 | |
Darren Tucker | 4515047 | 2006-07-12 22:34:17 +1000 | [diff] [blame] | 240 | /* sshd_config buffer */ |
| 241 | Buffer cfg; |
| 242 | |
Darren Tucker | 0999174 | 2004-07-17 17:05:14 +1000 | [diff] [blame] | 243 | /* message to be displayed after login */ |
| 244 | Buffer loginmsg; |
| 245 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 246 | /* Prototypes for various functions defined later in this file. */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 247 | void destroy_sensitive_data(void); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 248 | void demote_sensitive_data(void); |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 249 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 250 | static void do_ssh1_kex(void); |
| 251 | static void do_ssh2_kex(void); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 252 | |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 253 | /* |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 254 | * Close all listening sockets |
| 255 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 256 | static void |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 257 | close_listen_socks(void) |
| 258 | { |
| 259 | int i; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 260 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 261 | for (i = 0; i < num_listen_socks; i++) |
| 262 | close(listen_socks[i]); |
| 263 | num_listen_socks = -1; |
| 264 | } |
| 265 | |
Ben Lindstrom | d84df98 | 2001-12-06 16:35:40 +0000 | [diff] [blame] | 266 | static void |
| 267 | close_startup_pipes(void) |
| 268 | { |
| 269 | int i; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 270 | |
Ben Lindstrom | d84df98 | 2001-12-06 16:35:40 +0000 | [diff] [blame] | 271 | if (startup_pipes) |
| 272 | for (i = 0; i < options.max_startups; i++) |
| 273 | if (startup_pipes[i] != -1) |
| 274 | close(startup_pipes[i]); |
| 275 | } |
| 276 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 277 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 278 | * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP; |
| 279 | * the effect is to reread the configuration file (and to regenerate |
| 280 | * the server key). |
| 281 | */ |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 282 | |
| 283 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 284 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 285 | sighup_handler(int sig) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 286 | { |
Ben Lindstrom | 0795848 | 2001-12-06 16:19:01 +0000 | [diff] [blame] | 287 | int save_errno = errno; |
| 288 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 289 | received_sighup = 1; |
| 290 | signal(SIGHUP, sighup_handler); |
Ben Lindstrom | 0795848 | 2001-12-06 16:19:01 +0000 | [diff] [blame] | 291 | errno = save_errno; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 292 | } |
| 293 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 294 | /* |
| 295 | * Called from the main program after receiving SIGHUP. |
| 296 | * Restarts the server. |
| 297 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 298 | static void |
Ben Lindstrom | 31ca54a | 2001-02-09 02:11:24 +0000 | [diff] [blame] | 299 | sighup_restart(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 300 | { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 301 | logit("Received SIGHUP; restarting."); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 302 | close_listen_socks(); |
Ben Lindstrom | d84df98 | 2001-12-06 16:35:40 +0000 | [diff] [blame] | 303 | close_startup_pipes(); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 304 | execv(saved_argv[0], saved_argv); |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 305 | logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0], |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 306 | strerror(errno)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 307 | exit(1); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 308 | } |
| 309 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 310 | /* |
| 311 | * Generic signal handler for terminating signals in the master daemon. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 312 | */ |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 313 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 314 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 315 | sigterm_handler(int sig) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 316 | { |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 317 | received_sigterm = sig; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 318 | } |
| 319 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 320 | /* |
| 321 | * SIGCHLD handler. This is called whenever a child dies. This will then |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 322 | * reap any zombies left by exited children. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 323 | */ |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 324 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 325 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 326 | main_sigchld_handler(int sig) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 327 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 328 | int save_errno = errno; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 329 | pid_t pid; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 330 | int status; |
Damien Miller | 431f66b | 1999-11-21 18:31:57 +1100 | [diff] [blame] | 331 | |
Ben Lindstrom | 47fd811 | 2002-04-02 20:48:19 +0000 | [diff] [blame] | 332 | while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || |
| 333 | (pid < 0 && errno == EINTR)) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 334 | ; |
Damien Miller | 431f66b | 1999-11-21 18:31:57 +1100 | [diff] [blame] | 335 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 336 | signal(SIGCHLD, main_sigchld_handler); |
| 337 | errno = save_errno; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 338 | } |
| 339 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 340 | /* |
| 341 | * Signal handler for the alarm after the login grace period has expired. |
| 342 | */ |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 343 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 344 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 345 | grace_alarm_handler(int sig) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 346 | { |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 347 | /* XXX no idea how fix this signal handler */ |
| 348 | |
Darren Tucker | a8be9e2 | 2004-02-06 16:40:27 +1100 | [diff] [blame] | 349 | if (use_privsep && pmonitor != NULL && pmonitor->m_pid > 0) |
| 350 | kill(pmonitor->m_pid, SIGALRM); |
| 351 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 352 | /* Log error and exit. */ |
Damien Miller | d27a76d | 2002-09-27 13:22:31 +1000 | [diff] [blame] | 353 | fatal("Timeout before authentication for %s", get_remote_ipaddr()); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 354 | } |
| 355 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 356 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 357 | * Signal handler for the key regeneration alarm. Note that this |
| 358 | * alarm only occurs in the daemon waiting for connections, and it does not |
| 359 | * do anything with the private key or random state before forking. |
| 360 | * Thus there should be no concurrency control/asynchronous execution |
| 361 | * problems. |
| 362 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 363 | static void |
Ben Lindstrom | ca42d5f | 2001-03-09 18:25:32 +0000 | [diff] [blame] | 364 | generate_ephemeral_server_key(void) |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 365 | { |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 366 | u_int32_t rnd = 0; |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 367 | int i; |
| 368 | |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 369 | verbose("Generating %s%d bit RSA key.", |
Damien Miller | ff75ac4 | 2001-03-30 10:50:32 +1000 | [diff] [blame] | 370 | sensitive_data.server_key ? "new " : "", options.server_key_bits); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 371 | if (sensitive_data.server_key != NULL) |
| 372 | key_free(sensitive_data.server_key); |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 373 | sensitive_data.server_key = key_generate(KEY_RSA1, |
Damien Miller | ff75ac4 | 2001-03-30 10:50:32 +1000 | [diff] [blame] | 374 | options.server_key_bits); |
| 375 | verbose("RSA key generation complete."); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 376 | |
| 377 | for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) { |
| 378 | if (i % 4 == 0) |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 379 | rnd = arc4random(); |
| 380 | sensitive_data.ssh1_cookie[i] = rnd & 0xff; |
| 381 | rnd >>= 8; |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 382 | } |
| 383 | arc4random_stir(); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 384 | } |
Ben Lindstrom | 2f959b4 | 2001-01-11 06:20:23 +0000 | [diff] [blame] | 385 | |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 386 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 387 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 388 | key_regeneration_alarm(int sig) |
| 389 | { |
| 390 | int save_errno = errno; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 391 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 392 | signal(SIGALRM, SIG_DFL); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 393 | errno = save_errno; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 394 | key_do_regen = 1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 395 | } |
| 396 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 397 | static void |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 398 | sshd_exchange_identification(int sock_in, int sock_out) |
| 399 | { |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 400 | u_int i; |
| 401 | int mismatch; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 402 | int remote_major, remote_minor; |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 403 | int major, minor; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 404 | char *s; |
| 405 | char buf[256]; /* Must not be larger than remote_version. */ |
| 406 | char remote_version[256]; /* Must be at least as big as buf. */ |
| 407 | |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 408 | if ((options.protocol & SSH_PROTO_1) && |
| 409 | (options.protocol & SSH_PROTO_2)) { |
| 410 | major = PROTOCOL_MAJOR_1; |
| 411 | minor = 99; |
| 412 | } else if (options.protocol & SSH_PROTO_2) { |
| 413 | major = PROTOCOL_MAJOR_2; |
| 414 | minor = PROTOCOL_MINOR_2; |
| 415 | } else { |
| 416 | major = PROTOCOL_MAJOR_1; |
| 417 | minor = PROTOCOL_MINOR_1; |
| 418 | } |
| 419 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", major, minor, SSH_VERSION); |
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 | { |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [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 | c743134 | 2002-03-22 03:11:49 +0000 | [diff] [blame] | 583 | struct passwd *pw; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 584 | int i; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 585 | |
| 586 | /* Enable challenge-response authentication for privilege separation */ |
| 587 | privsep_challenge_enable(); |
| 588 | |
| 589 | for (i = 0; i < 256; i++) |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 590 | rnd[i] = arc4random(); |
| 591 | RAND_seed(rnd, sizeof(rnd)); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 592 | |
| 593 | /* Demote the private keys to public keys. */ |
| 594 | demote_sensitive_data(); |
| 595 | |
Ben Lindstrom | c743134 | 2002-03-22 03:11:49 +0000 | [diff] [blame] | 596 | if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL) |
Damien Miller | 0150c65 | 2002-04-24 09:49:09 +1000 | [diff] [blame] | 597 | fatal("Privilege separation user %s does not exist", |
| 598 | SSH_PRIVSEP_USER); |
Ben Lindstrom | c743134 | 2002-03-22 03:11:49 +0000 | [diff] [blame] | 599 | memset(pw->pw_passwd, 0, strlen(pw->pw_passwd)); |
| 600 | endpwent(); |
| 601 | |
Ben Lindstrom | a962c2f | 2002-07-04 00:14:17 +0000 | [diff] [blame] | 602 | /* Change our root directory */ |
Ben Lindstrom | 7a7edf7 | 2002-03-22 02:42:37 +0000 | [diff] [blame] | 603 | if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1) |
| 604 | fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR, |
| 605 | strerror(errno)); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 606 | if (chdir("/") == -1) |
Ben Lindstrom | 1ee9ec3 | 2002-03-22 03:14:45 +0000 | [diff] [blame] | 607 | fatal("chdir(\"/\"): %s", strerror(errno)); |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 608 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 609 | /* Drop our privileges */ |
Ben Lindstrom | c743134 | 2002-03-22 03:11:49 +0000 | [diff] [blame] | 610 | debug3("privsep user:group %u:%u", (u_int)pw->pw_uid, |
| 611 | (u_int)pw->pw_gid); |
Ben Lindstrom | fbcc3f7 | 2002-06-25 23:24:18 +0000 | [diff] [blame] | 612 | #if 0 |
Darren Tucker | d592048 | 2004-02-29 20:11:30 +1100 | [diff] [blame] | 613 | /* XXX not ready, too heavy after chroot */ |
Ben Lindstrom | c743134 | 2002-03-22 03:11:49 +0000 | [diff] [blame] | 614 | do_setusercontext(pw); |
Ben Lindstrom | fbcc3f7 | 2002-06-25 23:24:18 +0000 | [diff] [blame] | 615 | #else |
| 616 | gidset[0] = pw->pw_gid; |
Ben Lindstrom | fbcc3f7 | 2002-06-25 23:24:18 +0000 | [diff] [blame] | 617 | if (setgroups(1, gidset) < 0) |
| 618 | fatal("setgroups: %.100s", strerror(errno)); |
| 619 | permanently_set_uid(pw); |
| 620 | #endif |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 621 | } |
| 622 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 623 | static int |
| 624 | privsep_preauth(Authctxt *authctxt) |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 625 | { |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 626 | int status; |
| 627 | pid_t pid; |
| 628 | |
| 629 | /* Set up unprivileged child process to deal with network data */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 630 | pmonitor = monitor_init(); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 631 | /* Store a pointer to the kex for later rekeying */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 632 | pmonitor->m_pkex = &xxx_kex; |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 633 | |
| 634 | pid = fork(); |
| 635 | if (pid == -1) { |
| 636 | fatal("fork of unprivileged child failed"); |
| 637 | } else if (pid != 0) { |
Ben Lindstrom | ce0f634 | 2002-06-11 16:42:49 +0000 | [diff] [blame] | 638 | debug2("Network child is on pid %ld", (long)pid); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 639 | |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 640 | close(pmonitor->m_recvfd); |
Darren Tucker | a8be9e2 | 2004-02-06 16:40:27 +1100 | [diff] [blame] | 641 | pmonitor->m_pid = pid; |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 642 | monitor_child_preauth(authctxt, pmonitor); |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 643 | close(pmonitor->m_sendfd); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 644 | |
| 645 | /* Sync memory */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 646 | monitor_sync(pmonitor); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 647 | |
| 648 | /* Wait for the child's exit status */ |
Ben Lindstrom | 47fd811 | 2002-04-02 20:48:19 +0000 | [diff] [blame] | 649 | while (waitpid(pid, &status, 0) < 0) |
| 650 | if (errno != EINTR) |
| 651 | break; |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 652 | return (1); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 653 | } else { |
| 654 | /* child */ |
| 655 | |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 656 | close(pmonitor->m_sendfd); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 657 | |
| 658 | /* Demote the child */ |
| 659 | if (getuid() == 0 || geteuid() == 0) |
| 660 | privsep_preauth_child(); |
Ben Lindstrom | f90f58d | 2002-03-26 01:53:03 +0000 | [diff] [blame] | 661 | setproctitle("%s", "[net]"); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 662 | } |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 663 | return (0); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 664 | } |
| 665 | |
Ben Lindstrom | 0810519 | 2002-03-22 02:50:06 +0000 | [diff] [blame] | 666 | static void |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 667 | privsep_postauth(Authctxt *authctxt) |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 668 | { |
Tim Rice | 9dd3081 | 2002-07-07 13:43:36 -0700 | [diff] [blame] | 669 | #ifdef DISABLE_FD_PASSING |
Tim Rice | 8eff319 | 2002-06-25 15:35:15 -0700 | [diff] [blame] | 670 | if (1) { |
| 671 | #else |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 672 | if (authctxt->pw->pw_uid == 0 || options.use_login) { |
Tim Rice | 8eff319 | 2002-06-25 15:35:15 -0700 | [diff] [blame] | 673 | #endif |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 674 | /* File descriptor passing is broken or root login */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 675 | use_privsep = 0; |
Darren Tucker | 45b0142 | 2005-10-03 18:20:00 +1000 | [diff] [blame] | 676 | goto skip; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 677 | } |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 678 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 679 | /* New socket pair */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 680 | monitor_reinit(pmonitor); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 681 | |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 682 | pmonitor->m_pid = fork(); |
| 683 | if (pmonitor->m_pid == -1) |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 684 | fatal("fork of unprivileged child failed"); |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 685 | else if (pmonitor->m_pid != 0) { |
Ben Lindstrom | ce0f634 | 2002-06-11 16:42:49 +0000 | [diff] [blame] | 686 | debug2("User child is on pid %ld", (long)pmonitor->m_pid); |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 687 | close(pmonitor->m_recvfd); |
Darren Tucker | eb57862 | 2004-08-12 23:08:14 +1000 | [diff] [blame] | 688 | buffer_clear(&loginmsg); |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 689 | monitor_child_postauth(pmonitor); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 690 | |
| 691 | /* NEVERREACHED */ |
| 692 | exit(0); |
| 693 | } |
| 694 | |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 695 | close(pmonitor->m_sendfd); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 696 | |
| 697 | /* Demote the private keys to public keys. */ |
| 698 | demote_sensitive_data(); |
| 699 | |
| 700 | /* Drop privileges */ |
| 701 | do_setusercontext(authctxt->pw); |
| 702 | |
Darren Tucker | 45b0142 | 2005-10-03 18:20:00 +1000 | [diff] [blame] | 703 | skip: |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 704 | /* It is safe now to apply the key state */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 705 | monitor_apply_keystate(pmonitor); |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 706 | |
| 707 | /* |
| 708 | * Tell the packet layer that authentication was successful, since |
| 709 | * this information is not part of the key state. |
| 710 | */ |
| 711 | packet_set_authenticated(); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 712 | } |
| 713 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 714 | static char * |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 715 | list_hostkey_types(void) |
| 716 | { |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 717 | Buffer b; |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 718 | const char *p; |
| 719 | char *ret; |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 720 | int i; |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 721 | |
| 722 | buffer_init(&b); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 723 | for (i = 0; i < options.num_host_key_files; i++) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 724 | Key *key = sensitive_data.host_keys[i]; |
| 725 | if (key == NULL) |
| 726 | continue; |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 727 | switch (key->type) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 728 | case KEY_RSA: |
| 729 | case KEY_DSA: |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 730 | if (buffer_len(&b) > 0) |
| 731 | buffer_append(&b, ",", 1); |
| 732 | p = key_ssh_name(key); |
| 733 | buffer_append(&b, p, strlen(p)); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 734 | break; |
| 735 | } |
| 736 | } |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 737 | buffer_append(&b, "\0", 1); |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 738 | ret = xstrdup(buffer_ptr(&b)); |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 739 | buffer_free(&b); |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 740 | debug("list_hostkey_types: %s", ret); |
| 741 | return ret; |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 742 | } |
| 743 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 744 | Key * |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 745 | get_hostkey_by_type(int type) |
| 746 | { |
| 747 | int i; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 748 | |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 749 | for (i = 0; i < options.num_host_key_files; i++) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 750 | Key *key = sensitive_data.host_keys[i]; |
| 751 | if (key != NULL && key->type == type) |
| 752 | return key; |
| 753 | } |
| 754 | return NULL; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 755 | } |
| 756 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 757 | Key * |
| 758 | get_hostkey_by_index(int ind) |
| 759 | { |
| 760 | if (ind < 0 || ind >= options.num_host_key_files) |
| 761 | return (NULL); |
| 762 | return (sensitive_data.host_keys[ind]); |
| 763 | } |
| 764 | |
| 765 | int |
| 766 | get_hostkey_index(Key *key) |
| 767 | { |
| 768 | int i; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 769 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 770 | for (i = 0; i < options.num_host_key_files; i++) { |
| 771 | if (key == sensitive_data.host_keys[i]) |
| 772 | return (i); |
| 773 | } |
| 774 | return (-1); |
| 775 | } |
| 776 | |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 777 | /* |
| 778 | * returns 1 if connection should be dropped, 0 otherwise. |
| 779 | * dropping starts at connection #max_startups_begin with a probability |
| 780 | * of (max_startups_rate/100). the probability increases linearly until |
| 781 | * all connections are dropped for startups > max_startups |
| 782 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 783 | static int |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 784 | drop_connection(int startups) |
| 785 | { |
Darren Tucker | 178fa66 | 2004-11-05 20:09:09 +1100 | [diff] [blame] | 786 | int p, r; |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 787 | |
| 788 | if (startups < options.max_startups_begin) |
| 789 | return 0; |
| 790 | if (startups >= options.max_startups) |
| 791 | return 1; |
| 792 | if (options.max_startups_rate == 100) |
| 793 | return 1; |
| 794 | |
| 795 | p = 100 - options.max_startups_rate; |
| 796 | p *= startups - options.max_startups_begin; |
Darren Tucker | 178fa66 | 2004-11-05 20:09:09 +1100 | [diff] [blame] | 797 | p /= options.max_startups - options.max_startups_begin; |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 798 | p += options.max_startups_rate; |
Darren Tucker | 178fa66 | 2004-11-05 20:09:09 +1100 | [diff] [blame] | 799 | r = arc4random() % 100; |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 800 | |
Darren Tucker | 3269b13 | 2004-11-05 20:20:59 +1100 | [diff] [blame] | 801 | debug("drop_connection: p %d, r %d", p, r); |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 802 | return (r < p) ? 1 : 0; |
| 803 | } |
| 804 | |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 805 | static void |
| 806 | usage(void) |
| 807 | { |
Damien Miller | 0c889cd | 2004-03-22 09:36:00 +1100 | [diff] [blame] | 808 | fprintf(stderr, "%s, %s\n", |
Damien Miller | 2aa6d3c | 2004-09-12 16:53:04 +1000 | [diff] [blame] | 809 | SSH_RELEASE, SSLeay_version(SSLEAY_VERSION)); |
Damien Miller | b408786 | 2004-03-22 09:35:21 +1100 | [diff] [blame] | 810 | fprintf(stderr, |
| 811 | "usage: sshd [-46Ddeiqt] [-b bits] [-f config_file] [-g login_grace_time]\n" |
| 812 | " [-h host_key_file] [-k key_gen_time] [-o option] [-p port] [-u len]\n" |
| 813 | ); |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 814 | exit(1); |
| 815 | } |
| 816 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 817 | static void |
| 818 | send_rexec_state(int fd, Buffer *conf) |
| 819 | { |
| 820 | Buffer m; |
| 821 | |
| 822 | debug3("%s: entering fd = %d config len %d", __func__, fd, |
| 823 | buffer_len(conf)); |
| 824 | |
| 825 | /* |
| 826 | * Protocol from reexec master to child: |
| 827 | * string configuration |
| 828 | * u_int ephemeral_key_follows |
| 829 | * bignum e (only if ephemeral_key_follows == 1) |
| 830 | * bignum n " |
| 831 | * bignum d " |
| 832 | * bignum iqmp " |
| 833 | * bignum p " |
| 834 | * bignum q " |
Darren Tucker | c6f8219 | 2005-09-27 22:46:32 +1000 | [diff] [blame] | 835 | * string rngseed (only if OpenSSL is not self-seeded) |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 836 | */ |
| 837 | buffer_init(&m); |
| 838 | buffer_put_cstring(&m, buffer_ptr(conf)); |
| 839 | |
Darren Tucker | fc95970 | 2004-07-17 16:12:08 +1000 | [diff] [blame] | 840 | if (sensitive_data.server_key != NULL && |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 841 | sensitive_data.server_key->type == KEY_RSA1) { |
| 842 | buffer_put_int(&m, 1); |
| 843 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->e); |
| 844 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->n); |
| 845 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->d); |
| 846 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->iqmp); |
| 847 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->p); |
| 848 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->q); |
| 849 | } else |
| 850 | buffer_put_int(&m, 0); |
| 851 | |
Darren Tucker | c6f8219 | 2005-09-27 22:46:32 +1000 | [diff] [blame] | 852 | #ifndef OPENSSL_PRNG_ONLY |
| 853 | rexec_send_rng_seed(&m); |
| 854 | #endif |
| 855 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 856 | if (ssh_msg_send(fd, 0, &m) == -1) |
| 857 | fatal("%s: ssh_msg_send failed", __func__); |
| 858 | |
| 859 | buffer_free(&m); |
| 860 | |
| 861 | debug3("%s: done", __func__); |
| 862 | } |
| 863 | |
| 864 | static void |
| 865 | recv_rexec_state(int fd, Buffer *conf) |
| 866 | { |
| 867 | Buffer m; |
| 868 | char *cp; |
| 869 | u_int len; |
| 870 | |
| 871 | debug3("%s: entering fd = %d", __func__, fd); |
| 872 | |
| 873 | buffer_init(&m); |
| 874 | |
| 875 | if (ssh_msg_recv(fd, &m) == -1) |
| 876 | fatal("%s: ssh_msg_recv failed", __func__); |
| 877 | if (buffer_get_char(&m) != 0) |
| 878 | fatal("%s: rexec version mismatch", __func__); |
| 879 | |
| 880 | cp = buffer_get_string(&m, &len); |
| 881 | if (conf != NULL) |
| 882 | buffer_append(conf, cp, len + 1); |
| 883 | xfree(cp); |
| 884 | |
| 885 | if (buffer_get_int(&m)) { |
| 886 | if (sensitive_data.server_key != NULL) |
| 887 | key_free(sensitive_data.server_key); |
| 888 | sensitive_data.server_key = key_new_private(KEY_RSA1); |
| 889 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->e); |
| 890 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->n); |
| 891 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->d); |
| 892 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->iqmp); |
| 893 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->p); |
| 894 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->q); |
| 895 | rsa_generate_additional_parameters( |
| 896 | sensitive_data.server_key->rsa); |
| 897 | } |
Darren Tucker | c6f8219 | 2005-09-27 22:46:32 +1000 | [diff] [blame] | 898 | |
| 899 | #ifndef OPENSSL_PRNG_ONLY |
| 900 | rexec_recv_rng_seed(&m); |
| 901 | #endif |
| 902 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 903 | buffer_free(&m); |
| 904 | |
| 905 | debug3("%s: done", __func__); |
| 906 | } |
| 907 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 908 | /* |
| 909 | * Main program for the daemon. |
| 910 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 911 | int |
| 912 | main(int ac, char **av) |
| 913 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 914 | extern char *optarg; |
| 915 | extern int optind; |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 916 | int opt, j, i, on = 1; |
Damien Miller | 386c6a2 | 2004-06-30 22:40:20 +1000 | [diff] [blame] | 917 | int sock_in = -1, sock_out = -1, newsock = -1; |
Damien Miller | 166fca8 | 2000-04-20 07:42:21 +1000 | [diff] [blame] | 918 | pid_t pid; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 919 | socklen_t fromlen; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 920 | fd_set *fdset; |
| 921 | struct sockaddr_storage from; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 922 | const char *remote_ip; |
| 923 | int remote_port; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 924 | FILE *f; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 925 | struct addrinfo *ai; |
| 926 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
Damien Miller | b999719 | 2003-12-17 16:29:22 +1100 | [diff] [blame] | 927 | char *line; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 928 | int listen_sock, maxfd; |
Darren Tucker | 0f56ed1 | 2004-08-29 16:38:41 +1000 | [diff] [blame] | 929 | int startup_p[2] = { -1 , -1 }, config_s[2] = { -1 , -1 }; |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 930 | int startups = 0; |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame] | 931 | Key *key; |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 932 | Authctxt *authctxt; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 933 | int ret, key_used = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 934 | |
Kevin Steves | 0ea1d9d | 2002-04-25 18:17:04 +0000 | [diff] [blame] | 935 | #ifdef HAVE_SECUREWARE |
| 936 | (void)set_auth_parameters(ac, av); |
| 937 | #endif |
Damien Miller | 59d3d5b | 2003-08-22 09:34:41 +1000 | [diff] [blame] | 938 | __progname = ssh_get_progname(av[0]); |
Damien Miller | f9b625c | 2000-07-09 22:42:32 +1000 | [diff] [blame] | 939 | init_rng(); |
| 940 | |
Damien Miller | a8ed44b | 2003-01-10 09:53:12 +1100 | [diff] [blame] | 941 | /* Save argv. Duplicate so setproctitle emulation doesn't clobber it */ |
Damien Miller | b8c656e | 2000-06-28 15:22:41 +1000 | [diff] [blame] | 942 | saved_argc = ac; |
Darren Tucker | 17c5d03 | 2004-06-25 14:22:23 +1000 | [diff] [blame] | 943 | rexec_argc = ac; |
Darren Tucker | d8093e4 | 2006-05-04 16:24:34 +1000 | [diff] [blame] | 944 | saved_argv = xcalloc(ac + 1, sizeof(*saved_argv)); |
Damien Miller | a8ed44b | 2003-01-10 09:53:12 +1100 | [diff] [blame] | 945 | for (i = 0; i < ac; i++) |
| 946 | saved_argv[i] = xstrdup(av[i]); |
Damien Miller | 04cb536 | 2003-05-15 21:29:10 +1000 | [diff] [blame] | 947 | saved_argv[i] = NULL; |
Damien Miller | a8ed44b | 2003-01-10 09:53:12 +1100 | [diff] [blame] | 948 | |
| 949 | #ifndef HAVE_SETPROCTITLE |
| 950 | /* Prepare for later setproctitle emulation */ |
| 951 | compat_init_setproctitle(ac, av); |
Damien Miller | f2e3e9d | 2003-06-02 12:15:54 +1000 | [diff] [blame] | 952 | av = saved_argv; |
Damien Miller | a8ed44b | 2003-01-10 09:53:12 +1100 | [diff] [blame] | 953 | #endif |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 954 | |
Damien Miller | bfba354 | 2004-03-22 09:29:57 +1100 | [diff] [blame] | 955 | if (geteuid() == 0 && setgroups(0, NULL) == -1) |
| 956 | debug("setgroups(): %.200s", strerror(errno)); |
| 957 | |
Darren Tucker | ce321d8 | 2005-10-03 18:11:24 +1000 | [diff] [blame] | 958 | /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ |
| 959 | sanitise_stdfd(); |
| 960 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 961 | /* Initialize configuration options to their default values. */ |
| 962 | initialize_server_options(&options); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 963 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 964 | /* Parse command-line arguments. */ |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 965 | while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:dDeiqrtQR46")) != -1) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 966 | switch (opt) { |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 967 | case '4': |
Darren Tucker | 0f38323 | 2005-01-20 10:57:56 +1100 | [diff] [blame] | 968 | options.address_family = AF_INET; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 969 | break; |
| 970 | case '6': |
Darren Tucker | 0f38323 | 2005-01-20 10:57:56 +1100 | [diff] [blame] | 971 | options.address_family = AF_INET6; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 972 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 973 | case 'f': |
| 974 | config_file_name = optarg; |
| 975 | break; |
| 976 | case 'd': |
Darren Tucker | e98dfa3 | 2003-07-19 19:54:31 +1000 | [diff] [blame] | 977 | if (debug_flag == 0) { |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 978 | debug_flag = 1; |
| 979 | options.log_level = SYSLOG_LEVEL_DEBUG1; |
Darren Tucker | e98dfa3 | 2003-07-19 19:54:31 +1000 | [diff] [blame] | 980 | } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 981 | options.log_level++; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 982 | break; |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 983 | case 'D': |
| 984 | no_daemon_flag = 1; |
| 985 | break; |
Ben Lindstrom | 9fce9f0 | 2001-04-11 23:10:09 +0000 | [diff] [blame] | 986 | case 'e': |
| 987 | log_stderr = 1; |
| 988 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 989 | case 'i': |
| 990 | inetd_flag = 1; |
| 991 | break; |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 992 | case 'r': |
| 993 | rexec_flag = 0; |
| 994 | break; |
| 995 | case 'R': |
| 996 | rexeced_flag = 1; |
| 997 | inetd_flag = 1; |
| 998 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 999 | case 'Q': |
Ben Lindstrom | d539020 | 2001-01-29 08:07:43 +0000 | [diff] [blame] | 1000 | /* ignored */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1001 | break; |
| 1002 | case 'q': |
| 1003 | options.log_level = SYSLOG_LEVEL_QUIET; |
| 1004 | break; |
| 1005 | case 'b': |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1006 | options.server_key_bits = (int)strtonum(optarg, 256, |
| 1007 | 32768, NULL); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1008 | break; |
| 1009 | case 'p': |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1010 | options.ports_from_cmdline = 1; |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 1011 | if (options.num_ports >= MAX_PORTS) { |
| 1012 | fprintf(stderr, "too many ports.\n"); |
| 1013 | exit(1); |
| 1014 | } |
Ben Lindstrom | 19066a1 | 2001-04-12 23:39:26 +0000 | [diff] [blame] | 1015 | options.ports[options.num_ports++] = a2port(optarg); |
| 1016 | if (options.ports[options.num_ports-1] == 0) { |
| 1017 | fprintf(stderr, "Bad port number.\n"); |
| 1018 | exit(1); |
| 1019 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1020 | break; |
| 1021 | case 'g': |
Ben Lindstrom | 1bda4c8 | 2001-06-05 19:59:08 +0000 | [diff] [blame] | 1022 | if ((options.login_grace_time = convtime(optarg)) == -1) { |
| 1023 | fprintf(stderr, "Invalid login grace time.\n"); |
| 1024 | exit(1); |
| 1025 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1026 | break; |
| 1027 | case 'k': |
Ben Lindstrom | 1bda4c8 | 2001-06-05 19:59:08 +0000 | [diff] [blame] | 1028 | if ((options.key_regeneration_time = convtime(optarg)) == -1) { |
| 1029 | fprintf(stderr, "Invalid key regeneration interval.\n"); |
| 1030 | exit(1); |
| 1031 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1032 | break; |
| 1033 | case 'h': |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1034 | if (options.num_host_key_files >= MAX_HOSTKEYS) { |
| 1035 | fprintf(stderr, "too many host keys.\n"); |
| 1036 | exit(1); |
| 1037 | } |
| 1038 | options.host_key_files[options.num_host_key_files++] = optarg; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1039 | break; |
Ben Lindstrom | 794325a | 2001-08-06 21:09:07 +0000 | [diff] [blame] | 1040 | case 't': |
| 1041 | test_flag = 1; |
| 1042 | break; |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 1043 | case 'u': |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1044 | utmp_len = (u_int)strtonum(optarg, 0, MAXHOSTNAMELEN+1, NULL); |
Ben Lindstrom | 41daec7 | 2002-07-23 21:15:13 +0000 | [diff] [blame] | 1045 | if (utmp_len > MAXHOSTNAMELEN) { |
| 1046 | fprintf(stderr, "Invalid utmp length.\n"); |
| 1047 | exit(1); |
| 1048 | } |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 1049 | break; |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 1050 | case 'o': |
Damien Miller | b999719 | 2003-12-17 16:29:22 +1100 | [diff] [blame] | 1051 | line = xstrdup(optarg); |
| 1052 | if (process_server_config_line(&options, line, |
Darren Tucker | 4515047 | 2006-07-12 22:34:17 +1000 | [diff] [blame] | 1053 | "command-line", 0, NULL, NULL, NULL, NULL) != 0) |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1054 | exit(1); |
Damien Miller | b999719 | 2003-12-17 16:29:22 +1100 | [diff] [blame] | 1055 | xfree(line); |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 1056 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1057 | case '?': |
| 1058 | default: |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 1059 | usage(); |
| 1060 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1061 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1062 | } |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1063 | if (rexeced_flag || inetd_flag) |
| 1064 | rexec_flag = 0; |
| 1065 | if (rexec_flag && (av[0] == NULL || *av[0] != '/')) |
| 1066 | fatal("sshd re-exec requires execution with an absolute path"); |
| 1067 | if (rexeced_flag) |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1068 | closefrom(REEXEC_MIN_FREE_FD); |
| 1069 | else |
| 1070 | closefrom(REEXEC_DEVCRYPTO_RESERVED_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1071 | |
Ben Lindstrom | 425fb02 | 2001-03-29 00:31:20 +0000 | [diff] [blame] | 1072 | SSLeay_add_all_algorithms(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1073 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1074 | /* |
| 1075 | * Force logging to stderr until we have loaded the private host |
| 1076 | * key (unless started from inetd) |
| 1077 | */ |
Kevin Steves | ec84dc1 | 2000-12-13 17:45:15 +0000 | [diff] [blame] | 1078 | log_init(__progname, |
Damien Miller | 5aa5d78 | 2002-02-08 22:01:54 +1100 | [diff] [blame] | 1079 | options.log_level == SYSLOG_LEVEL_NOT_SET ? |
| 1080 | SYSLOG_LEVEL_INFO : options.log_level, |
| 1081 | options.log_facility == SYSLOG_FACILITY_NOT_SET ? |
| 1082 | SYSLOG_FACILITY_AUTH : options.log_facility, |
Ben Lindstrom | c2faa4a | 2002-11-09 15:50:03 +0000 | [diff] [blame] | 1083 | log_stderr || !inetd_flag); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1084 | |
Darren Tucker | 86c093d | 2004-03-08 22:59:03 +1100 | [diff] [blame] | 1085 | /* |
| 1086 | * Unset KRB5CCNAME, otherwise the user's session may inherit it from |
| 1087 | * root's environment |
Damien Miller | 94cf4c8 | 2005-07-17 17:04:47 +1000 | [diff] [blame] | 1088 | */ |
Darren Tucker | 9dc6c7d | 2005-02-02 18:30:33 +1100 | [diff] [blame] | 1089 | if (getenv("KRB5CCNAME") != NULL) |
| 1090 | unsetenv("KRB5CCNAME"); |
| 1091 | |
Tim Rice | 81ed518 | 2002-09-25 17:38:46 -0700 | [diff] [blame] | 1092 | #ifdef _UNICOS |
Darren Tucker | 1298496 | 2004-05-24 13:37:13 +1000 | [diff] [blame] | 1093 | /* Cray can define user privs drop all privs now! |
Ben Lindstrom | 6db66ff | 2001-08-06 23:29:16 +0000 | [diff] [blame] | 1094 | * Not needed on PRIV_SU systems! |
| 1095 | */ |
| 1096 | drop_cray_privs(); |
| 1097 | #endif |
| 1098 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1099 | sensitive_data.server_key = NULL; |
| 1100 | sensitive_data.ssh1_host_key = NULL; |
| 1101 | sensitive_data.have_ssh1_key = 0; |
| 1102 | sensitive_data.have_ssh2_key = 0; |
| 1103 | |
| 1104 | /* Fetch our configuration */ |
| 1105 | buffer_init(&cfg); |
| 1106 | if (rexeced_flag) |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1107 | recv_rexec_state(REEXEC_CONFIG_PASS_FD, &cfg); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1108 | else |
| 1109 | load_server_config(config_file_name, &cfg); |
| 1110 | |
Darren Tucker | 4515047 | 2006-07-12 22:34:17 +1000 | [diff] [blame] | 1111 | parse_server_config(&options, rexeced_flag ? "rexec" : config_file_name, |
| 1112 | &cfg, NULL, NULL, NULL); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1113 | |
Darren Tucker | c6f8219 | 2005-09-27 22:46:32 +1000 | [diff] [blame] | 1114 | seed_rng(); |
| 1115 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1116 | /* Fill in default values for those options not explicitly set. */ |
| 1117 | fill_default_server_options(&options); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1118 | |
Darren Tucker | 0f38323 | 2005-01-20 10:57:56 +1100 | [diff] [blame] | 1119 | /* set default channel AF */ |
| 1120 | channel_set_af(options.address_family); |
| 1121 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1122 | /* Check that there are no remaining arguments. */ |
| 1123 | if (optind < ac) { |
| 1124 | fprintf(stderr, "Extra argument %s.\n", av[optind]); |
| 1125 | exit(1); |
| 1126 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1127 | |
Damien Miller | 2aa6d3c | 2004-09-12 16:53:04 +1000 | [diff] [blame] | 1128 | debug("sshd version %.100s", SSH_RELEASE); |
Damien Miller | 2ccf661 | 1999-11-15 15:25:10 +1100 | [diff] [blame] | 1129 | |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1130 | /* load private host keys */ |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1131 | sensitive_data.host_keys = xcalloc(options.num_host_key_files, |
Ben Lindstrom | a962c2f | 2002-07-04 00:14:17 +0000 | [diff] [blame] | 1132 | sizeof(Key *)); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1133 | for (i = 0; i < options.num_host_key_files; i++) |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1134 | sensitive_data.host_keys[i] = NULL; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1135 | |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1136 | for (i = 0; i < options.num_host_key_files; i++) { |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame] | 1137 | key = key_load_private(options.host_key_files[i], "", NULL); |
| 1138 | sensitive_data.host_keys[i] = key; |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1139 | if (key == NULL) { |
Ben Lindstrom | 15f3386 | 2001-04-16 02:00:02 +0000 | [diff] [blame] | 1140 | error("Could not load host key: %s", |
| 1141 | options.host_key_files[i]); |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame] | 1142 | sensitive_data.host_keys[i] = NULL; |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1143 | continue; |
| 1144 | } |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 1145 | switch (key->type) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1146 | case KEY_RSA1: |
| 1147 | sensitive_data.ssh1_host_key = key; |
| 1148 | sensitive_data.have_ssh1_key = 1; |
| 1149 | break; |
| 1150 | case KEY_RSA: |
| 1151 | case KEY_DSA: |
| 1152 | sensitive_data.have_ssh2_key = 1; |
| 1153 | break; |
| 1154 | } |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame] | 1155 | debug("private host key: #%d type %d %s", i, key->type, |
| 1156 | key_type(key)); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1157 | } |
| 1158 | if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 1159 | logit("Disabling protocol version 1. Could not load host key"); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1160 | options.protocol &= ~SSH_PROTO_1; |
| 1161 | } |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1162 | if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 1163 | logit("Disabling protocol version 2. Could not load host key"); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1164 | options.protocol &= ~SSH_PROTO_2; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1165 | } |
Kevin Steves | adf74cd | 2001-02-05 14:22:50 +0000 | [diff] [blame] | 1166 | if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 1167 | logit("sshd: no hostkeys available -- exiting."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1168 | exit(1); |
| 1169 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1170 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1171 | /* Check certain values for sanity. */ |
| 1172 | if (options.protocol & SSH_PROTO_1) { |
| 1173 | if (options.server_key_bits < 512 || |
| 1174 | options.server_key_bits > 32768) { |
| 1175 | fprintf(stderr, "Bad server key size.\n"); |
| 1176 | exit(1); |
| 1177 | } |
| 1178 | /* |
| 1179 | * Check that server and host key lengths differ sufficiently. This |
| 1180 | * is necessary to make double encryption work with rsaref. Oh, I |
| 1181 | * hate software patents. I dont know if this can go? Niels |
| 1182 | */ |
| 1183 | if (options.server_key_bits > |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 1184 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) - |
| 1185 | SSH_KEY_BITS_RESERVED && options.server_key_bits < |
| 1186 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + |
| 1187 | SSH_KEY_BITS_RESERVED) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1188 | options.server_key_bits = |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 1189 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + |
| 1190 | SSH_KEY_BITS_RESERVED; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1191 | debug("Forcing server key to %d bits to make it differ from host key.", |
| 1192 | options.server_key_bits); |
| 1193 | } |
| 1194 | } |
| 1195 | |
Ben Lindstrom | a26ea63 | 2002-06-06 20:46:25 +0000 | [diff] [blame] | 1196 | if (use_privsep) { |
Ben Lindstrom | a26ea63 | 2002-06-06 20:46:25 +0000 | [diff] [blame] | 1197 | struct stat st; |
| 1198 | |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1199 | if (getpwnam(SSH_PRIVSEP_USER) == NULL) |
Ben Lindstrom | a26ea63 | 2002-06-06 20:46:25 +0000 | [diff] [blame] | 1200 | fatal("Privilege separation user %s does not exist", |
| 1201 | SSH_PRIVSEP_USER); |
| 1202 | if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) || |
| 1203 | (S_ISDIR(st.st_mode) == 0)) |
| 1204 | fatal("Missing privilege separation directory: %s", |
| 1205 | _PATH_PRIVSEP_CHROOT_DIR); |
Ben Lindstrom | 5962735 | 2002-06-27 18:02:21 +0000 | [diff] [blame] | 1206 | |
| 1207 | #ifdef HAVE_CYGWIN |
| 1208 | if (check_ntsec(_PATH_PRIVSEP_CHROOT_DIR) && |
| 1209 | (st.st_uid != getuid () || |
| 1210 | (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)) |
| 1211 | #else |
Ben Lindstrom | 2dfacb3 | 2002-06-23 00:33:47 +0000 | [diff] [blame] | 1212 | 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] | 1213 | #endif |
Damien Miller | 180fc5b | 2003-02-24 11:50:18 +1100 | [diff] [blame] | 1214 | fatal("%s must be owned by root and not group or " |
| 1215 | "world-writable.", _PATH_PRIVSEP_CHROOT_DIR); |
Ben Lindstrom | a26ea63 | 2002-06-06 20:46:25 +0000 | [diff] [blame] | 1216 | } |
| 1217 | |
Ben Lindstrom | 794325a | 2001-08-06 21:09:07 +0000 | [diff] [blame] | 1218 | /* Configuration looks good, so exit if in test mode. */ |
| 1219 | if (test_flag) |
| 1220 | exit(0); |
| 1221 | |
Damien Miller | 87aea25 | 2002-05-10 12:20:24 +1000 | [diff] [blame] | 1222 | /* |
| 1223 | * Clear out any supplemental groups we may have inherited. This |
| 1224 | * prevents inadvertent creation of files with bad modes (in the |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 1225 | * portable version at least, it's certainly possible for PAM |
| 1226 | * 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] | 1227 | * module which might be used). |
| 1228 | */ |
| 1229 | if (setgroups(0, NULL) < 0) |
| 1230 | debug("setgroups() failed: %.200s", strerror(errno)); |
| 1231 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1232 | if (rexec_flag) { |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1233 | rexec_argv = xcalloc(rexec_argc + 2, sizeof(char *)); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1234 | for (i = 0; i < rexec_argc; i++) { |
| 1235 | debug("rexec_argv[%d]='%s'", i, saved_argv[i]); |
| 1236 | rexec_argv[i] = saved_argv[i]; |
| 1237 | } |
| 1238 | rexec_argv[rexec_argc] = "-R"; |
| 1239 | rexec_argv[rexec_argc + 1] = NULL; |
| 1240 | } |
| 1241 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1242 | /* Initialize the log (it is reinitialized below in case we forked). */ |
Darren Tucker | ea7c812 | 2005-01-20 11:03:08 +1100 | [diff] [blame] | 1243 | if (debug_flag && (!inetd_flag || rexeced_flag)) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1244 | log_stderr = 1; |
Kevin Steves | ec84dc1 | 2000-12-13 17:45:15 +0000 | [diff] [blame] | 1245 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1246 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1247 | /* |
| 1248 | * If not in debugging mode, and not started from inetd, disconnect |
| 1249 | * from the controlling terminal, and fork. The original process |
| 1250 | * exits. |
| 1251 | */ |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 1252 | if (!(debug_flag || inetd_flag || no_daemon_flag)) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1253 | #ifdef TIOCNOTTY |
| 1254 | int fd; |
| 1255 | #endif /* TIOCNOTTY */ |
| 1256 | if (daemon(0, 0) < 0) |
| 1257 | fatal("daemon() failed: %.200s", strerror(errno)); |
| 1258 | |
| 1259 | /* Disconnect from the controlling tty. */ |
| 1260 | #ifdef TIOCNOTTY |
Ben Lindstrom | 31ca54a | 2001-02-09 02:11:24 +0000 | [diff] [blame] | 1261 | fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1262 | if (fd >= 0) { |
| 1263 | (void) ioctl(fd, TIOCNOTTY, NULL); |
| 1264 | close(fd); |
| 1265 | } |
| 1266 | #endif /* TIOCNOTTY */ |
| 1267 | } |
| 1268 | /* Reinitialize the log (because of the fork above). */ |
Kevin Steves | ec84dc1 | 2000-12-13 17:45:15 +0000 | [diff] [blame] | 1269 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1270 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1271 | /* Initialize the random number generator. */ |
| 1272 | arc4random_stir(); |
| 1273 | |
| 1274 | /* Chdir to the root directory so that the current disk can be |
| 1275 | unmounted if desired. */ |
| 1276 | chdir("/"); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1277 | |
Ben Lindstrom | de71cda | 2001-03-24 00:43:26 +0000 | [diff] [blame] | 1278 | /* ignore SIGPIPE */ |
| 1279 | signal(SIGPIPE, SIG_IGN); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1280 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1281 | /* Start listening for a socket, unless started from inetd. */ |
| 1282 | if (inetd_flag) { |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1283 | int fd; |
| 1284 | |
Damien Miller | 994cf14 | 2000-07-21 10:19:44 +1000 | [diff] [blame] | 1285 | startup_pipe = -1; |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1286 | if (rexeced_flag) { |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1287 | close(REEXEC_CONFIG_PASS_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1288 | sock_in = sock_out = dup(STDIN_FILENO); |
| 1289 | if (!debug_flag) { |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1290 | startup_pipe = dup(REEXEC_STARTUP_PIPE_FD); |
| 1291 | close(REEXEC_STARTUP_PIPE_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1292 | } |
| 1293 | } else { |
| 1294 | sock_in = dup(STDIN_FILENO); |
| 1295 | sock_out = dup(STDOUT_FILENO); |
| 1296 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1297 | /* |
| 1298 | * We intentionally do not close the descriptors 0, 1, and 2 |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1299 | * as our code for setting the descriptors won't work if |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1300 | * ttyfd happens to be one of those. |
| 1301 | */ |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1302 | if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { |
| 1303 | dup2(fd, STDIN_FILENO); |
| 1304 | dup2(fd, STDOUT_FILENO); |
| 1305 | if (fd > STDOUT_FILENO) |
| 1306 | close(fd); |
| 1307 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1308 | debug("inetd sockets after dupping: %d, %d", sock_in, sock_out); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1309 | if ((options.protocol & SSH_PROTO_1) && |
| 1310 | sensitive_data.server_key == NULL) |
Ben Lindstrom | ca42d5f | 2001-03-09 18:25:32 +0000 | [diff] [blame] | 1311 | generate_ephemeral_server_key(); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1312 | } else { |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1313 | for (ai = options.listen_addrs; ai; ai = ai->ai_next) { |
| 1314 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) |
| 1315 | continue; |
| 1316 | if (num_listen_socks >= MAX_LISTEN_SOCKS) |
| 1317 | fatal("Too many listen sockets. " |
| 1318 | "Enlarge MAX_LISTEN_SOCKS"); |
Darren Tucker | 96d4710 | 2005-02-09 09:53:48 +1100 | [diff] [blame] | 1319 | if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen, |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1320 | ntop, sizeof(ntop), strport, sizeof(strport), |
Darren Tucker | 96d4710 | 2005-02-09 09:53:48 +1100 | [diff] [blame] | 1321 | NI_NUMERICHOST|NI_NUMERICSERV)) != 0) { |
| 1322 | error("getnameinfo failed: %.100s", |
| 1323 | (ret != EAI_SYSTEM) ? gai_strerror(ret) : |
| 1324 | strerror(errno)); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1325 | continue; |
| 1326 | } |
| 1327 | /* Create socket for listening. */ |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 1328 | listen_sock = socket(ai->ai_family, ai->ai_socktype, |
| 1329 | ai->ai_protocol); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1330 | if (listen_sock < 0) { |
| 1331 | /* kernel may not support ipv6 */ |
| 1332 | verbose("socket: %.100s", strerror(errno)); |
| 1333 | continue; |
| 1334 | } |
Damien Miller | 232711f | 2004-06-15 10:35:30 +1000 | [diff] [blame] | 1335 | if (set_nonblock(listen_sock) == -1) { |
Darren Tucker | efa3706 | 2004-02-24 09:20:29 +1100 | [diff] [blame] | 1336 | close(listen_sock); |
| 1337 | continue; |
| 1338 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1339 | /* |
Damien Miller | e1383ce | 2002-09-19 11:49:37 +1000 | [diff] [blame] | 1340 | * Set socket options. |
| 1341 | * Allow local port reuse in TIME_WAIT. |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1342 | */ |
Damien Miller | e1383ce | 2002-09-19 11:49:37 +1000 | [diff] [blame] | 1343 | if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, |
| 1344 | &on, sizeof(on)) == -1) |
| 1345 | error("setsockopt SO_REUSEADDR: %s", strerror(errno)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1346 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1347 | debug("Bind to port %s on %s.", strport, ntop); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1348 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1349 | /* Bind the socket to the desired port. */ |
Damien Miller | 0a4e27d | 2001-02-18 12:36:39 +1100 | [diff] [blame] | 1350 | if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) { |
| 1351 | if (!ai->ai_next) |
| 1352 | error("Bind to port %s on %s failed: %.200s.", |
| 1353 | strport, ntop, strerror(errno)); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1354 | close(listen_sock); |
| 1355 | continue; |
| 1356 | } |
| 1357 | listen_socks[num_listen_socks] = listen_sock; |
| 1358 | num_listen_socks++; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1359 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1360 | /* Start listening on the port. */ |
Darren Tucker | 3175eb9 | 2003-12-09 19:15:11 +1100 | [diff] [blame] | 1361 | if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0) |
Damien Miller | b24c2f8 | 2006-03-15 12:04:36 +1100 | [diff] [blame] | 1362 | fatal("listen on [%s]:%s: %.100s", |
| 1363 | ntop, strport, strerror(errno)); |
| 1364 | logit("Server listening on %s port %s.", ntop, strport); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1365 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1366 | freeaddrinfo(options.listen_addrs); |
| 1367 | |
| 1368 | if (!num_listen_socks) |
| 1369 | fatal("Cannot bind any address."); |
| 1370 | |
Ben Lindstrom | 9809786 | 2001-06-25 05:10:20 +0000 | [diff] [blame] | 1371 | if (options.protocol & SSH_PROTO_1) |
| 1372 | generate_ephemeral_server_key(); |
| 1373 | |
| 1374 | /* |
| 1375 | * Arrange to restart on SIGHUP. The handler needs |
| 1376 | * listen_sock. |
| 1377 | */ |
| 1378 | signal(SIGHUP, sighup_handler); |
| 1379 | |
| 1380 | signal(SIGTERM, sigterm_handler); |
| 1381 | signal(SIGQUIT, sigterm_handler); |
| 1382 | |
| 1383 | /* Arrange SIGCHLD to be caught. */ |
| 1384 | signal(SIGCHLD, main_sigchld_handler); |
| 1385 | |
| 1386 | /* Write out the pid file after the sigterm handler is setup */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1387 | if (!debug_flag) { |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1388 | /* |
Ben Lindstrom | 7ad9710 | 2000-12-06 01:42:49 +0000 | [diff] [blame] | 1389 | * Record our pid in /var/run/sshd.pid to make it |
| 1390 | * easier to kill the correct sshd. We don't want to |
| 1391 | * do this before the bind above because the bind will |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1392 | * fail if there already is a daemon, and this will |
| 1393 | * overwrite any old pid in the file. |
| 1394 | */ |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 1395 | f = fopen(options.pid_file, "wb"); |
Darren Tucker | e532704 | 2003-07-03 13:40:44 +1000 | [diff] [blame] | 1396 | if (f == NULL) { |
| 1397 | error("Couldn't create pid file \"%s\": %s", |
| 1398 | options.pid_file, strerror(errno)); |
| 1399 | } else { |
Ben Lindstrom | ce0f634 | 2002-06-11 16:42:49 +0000 | [diff] [blame] | 1400 | fprintf(f, "%ld\n", (long) getpid()); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1401 | fclose(f); |
| 1402 | } |
| 1403 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1404 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1405 | /* setup fd set for listen */ |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1406 | fdset = NULL; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1407 | maxfd = 0; |
| 1408 | for (i = 0; i < num_listen_socks; i++) |
| 1409 | if (listen_socks[i] > maxfd) |
| 1410 | maxfd = listen_socks[i]; |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1411 | /* pipes connected to unauthenticated childs */ |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1412 | startup_pipes = xcalloc(options.max_startups, sizeof(int)); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1413 | for (i = 0; i < options.max_startups; i++) |
| 1414 | startup_pipes[i] = -1; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1415 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1416 | /* |
| 1417 | * Stay listening for connections until the system crashes or |
| 1418 | * the daemon is killed with a signal. |
| 1419 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1420 | for (;;) { |
| 1421 | if (received_sighup) |
| 1422 | sighup_restart(); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1423 | if (fdset != NULL) |
| 1424 | xfree(fdset); |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1425 | fdset = (fd_set *)xcalloc(howmany(maxfd + 1, NFDBITS), |
| 1426 | sizeof(fd_mask)); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1427 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1428 | for (i = 0; i < num_listen_socks; i++) |
| 1429 | FD_SET(listen_socks[i], fdset); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1430 | for (i = 0; i < options.max_startups; i++) |
| 1431 | if (startup_pipes[i] != -1) |
| 1432 | FD_SET(startup_pipes[i], fdset); |
| 1433 | |
| 1434 | /* Wait in select until there is a connection. */ |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 1435 | ret = select(maxfd+1, fdset, NULL, NULL, NULL); |
| 1436 | if (ret < 0 && errno != EINTR) |
| 1437 | error("select: %.100s", strerror(errno)); |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 1438 | if (received_sigterm) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 1439 | logit("Received signal %d; terminating.", |
Ben Lindstrom | f8f065b | 2001-12-06 17:52:16 +0000 | [diff] [blame] | 1440 | (int) received_sigterm); |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 1441 | close_listen_socks(); |
| 1442 | unlink(options.pid_file); |
| 1443 | exit(255); |
| 1444 | } |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 1445 | if (key_used && key_do_regen) { |
Ben Lindstrom | ca42d5f | 2001-03-09 18:25:32 +0000 | [diff] [blame] | 1446 | generate_ephemeral_server_key(); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 1447 | key_used = 0; |
| 1448 | key_do_regen = 0; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1449 | } |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 1450 | if (ret < 0) |
| 1451 | continue; |
| 1452 | |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1453 | for (i = 0; i < options.max_startups; i++) |
| 1454 | if (startup_pipes[i] != -1 && |
| 1455 | FD_ISSET(startup_pipes[i], fdset)) { |
| 1456 | /* |
| 1457 | * the read end of the pipe is ready |
| 1458 | * if the child has closed the pipe |
Ben Lindstrom | 4dccfa5 | 2000-12-28 16:40:05 +0000 | [diff] [blame] | 1459 | * after successful authentication |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1460 | * or if the child has died |
| 1461 | */ |
| 1462 | close(startup_pipes[i]); |
| 1463 | startup_pipes[i] = -1; |
| 1464 | startups--; |
| 1465 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1466 | for (i = 0; i < num_listen_socks; i++) { |
| 1467 | if (!FD_ISSET(listen_socks[i], fdset)) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1468 | continue; |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1469 | fromlen = sizeof(from); |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1470 | newsock = accept(listen_socks[i], |
| 1471 | (struct sockaddr *)&from, &fromlen); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1472 | if (newsock < 0) { |
| 1473 | if (errno != EINTR && errno != EWOULDBLOCK) |
| 1474 | error("accept: %.100s", strerror(errno)); |
| 1475 | continue; |
| 1476 | } |
Damien Miller | 232711f | 2004-06-15 10:35:30 +1000 | [diff] [blame] | 1477 | if (unset_nonblock(newsock) == -1) { |
Darren Tucker | efa3706 | 2004-02-24 09:20:29 +1100 | [diff] [blame] | 1478 | close(newsock); |
| 1479 | continue; |
| 1480 | } |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 1481 | if (drop_connection(startups) == 1) { |
| 1482 | debug("drop connection #%d", startups); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1483 | close(newsock); |
| 1484 | continue; |
| 1485 | } |
| 1486 | if (pipe(startup_p) == -1) { |
| 1487 | close(newsock); |
| 1488 | continue; |
| 1489 | } |
| 1490 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1491 | if (rexec_flag && socketpair(AF_UNIX, |
| 1492 | SOCK_STREAM, 0, config_s) == -1) { |
| 1493 | error("reexec socketpair: %s", |
| 1494 | strerror(errno)); |
| 1495 | close(newsock); |
| 1496 | close(startup_p[0]); |
| 1497 | close(startup_p[1]); |
| 1498 | continue; |
| 1499 | } |
| 1500 | |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1501 | for (j = 0; j < options.max_startups; j++) |
| 1502 | if (startup_pipes[j] == -1) { |
| 1503 | startup_pipes[j] = startup_p[0]; |
| 1504 | if (maxfd < startup_p[0]) |
| 1505 | maxfd = startup_p[0]; |
| 1506 | startups++; |
| 1507 | break; |
| 1508 | } |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 1509 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1510 | /* |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1511 | * Got connection. Fork a child to handle it, unless |
| 1512 | * we are in debugging mode. |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1513 | */ |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1514 | if (debug_flag) { |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1515 | /* |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1516 | * In debugging mode. Close the listening |
| 1517 | * socket, and start processing the |
| 1518 | * connection without forking. |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1519 | */ |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1520 | debug("Server will not fork when running in debugging mode."); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1521 | close_listen_socks(); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1522 | sock_in = newsock; |
| 1523 | sock_out = newsock; |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1524 | close(startup_p[0]); |
| 1525 | close(startup_p[1]); |
Damien Miller | 4d97ba2 | 2000-07-11 18:15:50 +1000 | [diff] [blame] | 1526 | startup_pipe = -1; |
Damien Miller | 182ee6e | 2000-07-12 09:45:27 +1000 | [diff] [blame] | 1527 | pid = getpid(); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1528 | if (rexec_flag) { |
| 1529 | send_rexec_state(config_s[0], |
| 1530 | &cfg); |
| 1531 | close(config_s[0]); |
| 1532 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1533 | break; |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1534 | } else { |
| 1535 | /* |
| 1536 | * Normal production daemon. Fork, and have |
| 1537 | * the child process the connection. The |
| 1538 | * parent continues listening. |
| 1539 | */ |
| 1540 | if ((pid = fork()) == 0) { |
| 1541 | /* |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1542 | * Child. Close the listening and |
| 1543 | * max_startup sockets. Start using |
| 1544 | * the accepted socket. Reinitialize |
| 1545 | * logging (since our pid has changed). |
| 1546 | * We break out of the loop to handle |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1547 | * the connection. |
| 1548 | */ |
| 1549 | startup_pipe = startup_p[1]; |
Ben Lindstrom | d84df98 | 2001-12-06 16:35:40 +0000 | [diff] [blame] | 1550 | close_startup_pipes(); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1551 | close_listen_socks(); |
| 1552 | sock_in = newsock; |
| 1553 | sock_out = newsock; |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1554 | log_init(__progname, |
| 1555 | options.log_level, |
| 1556 | options.log_facility, |
| 1557 | log_stderr); |
Darren Tucker | 0f56ed1 | 2004-08-29 16:38:41 +1000 | [diff] [blame] | 1558 | if (rexec_flag) |
| 1559 | close(config_s[0]); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1560 | break; |
| 1561 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1562 | } |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1563 | |
| 1564 | /* Parent. Stay in the loop. */ |
| 1565 | if (pid < 0) |
| 1566 | error("fork: %.100s", strerror(errno)); |
| 1567 | else |
Ben Lindstrom | ce0f634 | 2002-06-11 16:42:49 +0000 | [diff] [blame] | 1568 | debug("Forked child %ld.", (long)pid); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1569 | |
| 1570 | close(startup_p[1]); |
| 1571 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1572 | if (rexec_flag) { |
| 1573 | send_rexec_state(config_s[0], &cfg); |
| 1574 | close(config_s[0]); |
| 1575 | close(config_s[1]); |
| 1576 | } |
| 1577 | |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1578 | /* |
| 1579 | * Mark that the key has been used (it |
| 1580 | * was "given" to the child). |
| 1581 | */ |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 1582 | if ((options.protocol & SSH_PROTO_1) && |
| 1583 | key_used == 0) { |
| 1584 | /* Schedule server key regeneration alarm. */ |
Ben Lindstrom | 5ade9ab | 2003-08-25 01:16:21 +0000 | [diff] [blame] | 1585 | signal(SIGALRM, key_regeneration_alarm); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 1586 | alarm(options.key_regeneration_time); |
| 1587 | key_used = 1; |
| 1588 | } |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1589 | |
| 1590 | arc4random_stir(); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1591 | close(newsock); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1592 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1593 | /* child process check (or debug mode) */ |
| 1594 | if (num_listen_socks < 0) |
| 1595 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1596 | } |
| 1597 | } |
| 1598 | |
| 1599 | /* This is the child processing a new connection. */ |
Damien Miller | 57aae98 | 2004-03-08 23:11:25 +1100 | [diff] [blame] | 1600 | setproctitle("%s", "[accepted]"); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1601 | |
Darren Tucker | 6832b83 | 2004-08-12 22:36:51 +1000 | [diff] [blame] | 1602 | /* |
| 1603 | * Create a new session and process group since the 4.4BSD |
| 1604 | * setlogin() affects the entire process group. We don't |
| 1605 | * want the child to be able to affect the parent. |
| 1606 | */ |
| 1607 | #if !defined(SSHD_ACQUIRES_CTTY) |
| 1608 | /* |
| 1609 | * If setsid is called, on some platforms sshd will later acquire a |
| 1610 | * controlling terminal which will result in "could not set |
| 1611 | * controlling tty" errors. |
| 1612 | */ |
| 1613 | if (!debug_flag && !inetd_flag && setsid() < 0) |
| 1614 | error("setsid: %.100s", strerror(errno)); |
| 1615 | #endif |
| 1616 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1617 | if (rexec_flag) { |
| 1618 | int fd; |
| 1619 | |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1620 | debug("rexec start in %d out %d newsock %d pipe %d sock %d", |
| 1621 | sock_in, sock_out, newsock, startup_pipe, config_s[0]); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1622 | dup2(newsock, STDIN_FILENO); |
| 1623 | dup2(STDIN_FILENO, STDOUT_FILENO); |
| 1624 | if (startup_pipe == -1) |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1625 | close(REEXEC_STARTUP_PIPE_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1626 | else |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1627 | dup2(startup_pipe, REEXEC_STARTUP_PIPE_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1628 | |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1629 | dup2(config_s[1], REEXEC_CONFIG_PASS_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1630 | close(config_s[1]); |
Darren Tucker | d883593 | 2004-08-12 22:42:29 +1000 | [diff] [blame] | 1631 | if (startup_pipe != -1) |
| 1632 | close(startup_pipe); |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1633 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1634 | execv(rexec_argv[0], rexec_argv); |
| 1635 | |
| 1636 | /* Reexec has failed, fall back and continue */ |
| 1637 | error("rexec of %s failed: %s", rexec_argv[0], strerror(errno)); |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1638 | recv_rexec_state(REEXEC_CONFIG_PASS_FD, NULL); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1639 | log_init(__progname, options.log_level, |
| 1640 | options.log_facility, log_stderr); |
| 1641 | |
| 1642 | /* Clean up fds */ |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1643 | startup_pipe = REEXEC_STARTUP_PIPE_FD; |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1644 | close(config_s[1]); |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1645 | close(REEXEC_CONFIG_PASS_FD); |
| 1646 | newsock = sock_out = sock_in = dup(STDIN_FILENO); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1647 | if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { |
| 1648 | dup2(fd, STDIN_FILENO); |
| 1649 | dup2(fd, STDOUT_FILENO); |
| 1650 | if (fd > STDERR_FILENO) |
| 1651 | close(fd); |
| 1652 | } |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1653 | debug("rexec cleanup in %d out %d newsock %d pipe %d sock %d", |
| 1654 | sock_in, sock_out, newsock, startup_pipe, config_s[0]); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1655 | } |
| 1656 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1657 | /* |
| 1658 | * Disable the key regeneration alarm. We will not regenerate the |
| 1659 | * key since we are no longer in a position to give it to anyone. We |
| 1660 | * will not restart on SIGHUP since it no longer makes sense. |
| 1661 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1662 | alarm(0); |
| 1663 | signal(SIGALRM, SIG_DFL); |
| 1664 | signal(SIGHUP, SIG_DFL); |
| 1665 | signal(SIGTERM, SIG_DFL); |
| 1666 | signal(SIGQUIT, SIG_DFL); |
| 1667 | signal(SIGCHLD, SIG_DFL); |
Damien Miller | 4e0f5e1 | 2000-08-29 11:05:50 +1100 | [diff] [blame] | 1668 | signal(SIGINT, SIG_DFL); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1669 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1670 | /* |
| 1671 | * Register our connection. This turns encryption off because we do |
| 1672 | * not have a key. |
| 1673 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1674 | packet_set_connection(sock_in, sock_out); |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 1675 | packet_set_server(); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1676 | |
Damien Miller | 4f1d6b2 | 2005-05-26 11:59:32 +1000 | [diff] [blame] | 1677 | /* Set SO_KEEPALIVE if requested. */ |
| 1678 | if (options.tcp_keep_alive && packet_connection_is_on_socket() && |
| 1679 | setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) < 0) |
| 1680 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); |
| 1681 | |
Damien Miller | 677257f | 2005-06-17 12:55:03 +1000 | [diff] [blame] | 1682 | if ((remote_port = get_remote_port()) < 0) { |
| 1683 | debug("get_remote_port failed"); |
| 1684 | cleanup_exit(255); |
| 1685 | } |
Damien Miller | 4d3fd54 | 2005-11-05 15:13:24 +1100 | [diff] [blame] | 1686 | |
| 1687 | /* |
| 1688 | * We use get_canonical_hostname with usedns = 0 instead of |
| 1689 | * get_remote_ipaddr here so IP options will be checked. |
| 1690 | */ |
Damien Miller | eb13e55 | 2006-06-13 13:03:53 +1000 | [diff] [blame] | 1691 | (void) get_canonical_hostname(0); |
| 1692 | /* |
| 1693 | * The rest of the code depends on the fact that |
| 1694 | * get_remote_ipaddr() caches the remote ip, even if |
| 1695 | * the socket goes away. |
| 1696 | */ |
| 1697 | remote_ip = get_remote_ipaddr(); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1698 | |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 1699 | #ifdef SSH_AUDIT_EVENTS |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 1700 | audit_connection_from(remote_ip, remote_port); |
| 1701 | #endif |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1702 | #ifdef LIBWRAP |
Damien Miller | 6a4a4b9 | 2001-11-12 11:07:11 +1100 | [diff] [blame] | 1703 | /* Check whether logins are denied from this host. */ |
Darren Tucker | 586b0b9 | 2004-06-25 13:34:31 +1000 | [diff] [blame] | 1704 | if (packet_connection_is_on_socket()) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1705 | struct request_info req; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1706 | |
Ben Lindstrom | ce89dac | 2001-09-12 16:58:04 +0000 | [diff] [blame] | 1707 | request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1708 | fromhost(&req); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1709 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1710 | if (!hosts_access(&req)) { |
Damien Miller | 6a4a4b9 | 2001-11-12 11:07:11 +1100 | [diff] [blame] | 1711 | debug("Connection refused by tcp wrapper"); |
Ben Lindstrom | 7de696e | 2001-03-29 00:45:12 +0000 | [diff] [blame] | 1712 | refuse(&req); |
Damien Miller | 6a4a4b9 | 2001-11-12 11:07:11 +1100 | [diff] [blame] | 1713 | /* NOTREACHED */ |
| 1714 | fatal("libwrap refuse returns"); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1715 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1716 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1717 | #endif /* LIBWRAP */ |
Damien Miller | 6a4a4b9 | 2001-11-12 11:07:11 +1100 | [diff] [blame] | 1718 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1719 | /* Log the connection. */ |
| 1720 | verbose("Connection from %.500s port %d", remote_ip, remote_port); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1721 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1722 | /* |
Damien Miller | 788f212 | 2005-11-05 15:14:59 +1100 | [diff] [blame] | 1723 | * We don't want to listen forever unless the other side |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1724 | * successfully authenticates itself. So we set up an alarm which is |
| 1725 | * cleared after successful authentication. A limit of zero |
Damien Miller | 788f212 | 2005-11-05 15:14:59 +1100 | [diff] [blame] | 1726 | * 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] | 1727 | * mode; it is just annoying to have the server exit just when you |
| 1728 | * are about to discover the bug. |
| 1729 | */ |
Ben Lindstrom | 5ade9ab | 2003-08-25 01:16:21 +0000 | [diff] [blame] | 1730 | signal(SIGALRM, grace_alarm_handler); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1731 | if (!debug_flag) |
| 1732 | alarm(options.login_grace_time); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1733 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 1734 | sshd_exchange_identification(sock_in, sock_out); |
Darren Tucker | ec960f2 | 2003-08-13 20:37:05 +1000 | [diff] [blame] | 1735 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1736 | packet_set_nonblocking(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1737 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1738 | /* allocate authentication context */ |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1739 | authctxt = xcalloc(1, sizeof(*authctxt)); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1740 | |
Darren Tucker | f3bb434 | 2005-03-31 21:39:25 +1000 | [diff] [blame] | 1741 | authctxt->loginmsg = &loginmsg; |
| 1742 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1743 | /* XXX global for cleanup, access from other modules */ |
| 1744 | the_authctxt = authctxt; |
| 1745 | |
Darren Tucker | 5c14c73 | 2005-01-24 21:55:49 +1100 | [diff] [blame] | 1746 | /* prepare buffer to collect messages to display to user after login */ |
| 1747 | buffer_init(&loginmsg); |
| 1748 | |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1749 | if (use_privsep) |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1750 | if (privsep_preauth(authctxt) == 1) |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1751 | goto authenticated; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1752 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1753 | /* perform the key exchange */ |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1754 | /* authenticate user and start session */ |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 1755 | if (compat20) { |
| 1756 | do_ssh2_kex(); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1757 | do_authentication2(authctxt); |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 1758 | } else { |
| 1759 | do_ssh1_kex(); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1760 | do_authentication(authctxt); |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 1761 | } |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1762 | /* |
| 1763 | * If we use privilege separation, the unprivileged child transfers |
| 1764 | * the current keystate and exits |
| 1765 | */ |
| 1766 | if (use_privsep) { |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 1767 | mm_send_keystate(pmonitor); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1768 | exit(0); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1769 | } |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1770 | |
| 1771 | authenticated: |
Damien Miller | 7bff1a9 | 2005-12-24 14:59:12 +1100 | [diff] [blame] | 1772 | /* |
| 1773 | * Cancel the alarm we set to limit the time taken for |
| 1774 | * authentication. |
| 1775 | */ |
| 1776 | alarm(0); |
| 1777 | signal(SIGALRM, SIG_DFL); |
| 1778 | if (startup_pipe != -1) { |
| 1779 | close(startup_pipe); |
| 1780 | startup_pipe = -1; |
| 1781 | } |
| 1782 | |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 1783 | #ifdef SSH_AUDIT_EVENTS |
| 1784 | audit_event(SSH_AUTH_SUCCESS); |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 1785 | #endif |
| 1786 | |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 1787 | /* |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1788 | * In privilege separation, we fork another child and prepare |
| 1789 | * file descriptor passing. |
| 1790 | */ |
| 1791 | if (use_privsep) { |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1792 | privsep_postauth(authctxt); |
| 1793 | /* the monitor process [priv] will not return */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1794 | if (!compat20) |
| 1795 | destroy_sensitive_data(); |
| 1796 | } |
Ben Lindstrom | 73ab9ba | 2002-03-22 01:27:35 +0000 | [diff] [blame] | 1797 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1798 | /* Start session. */ |
Ben Lindstrom | 73ab9ba | 2002-03-22 01:27:35 +0000 | [diff] [blame] | 1799 | do_authenticated(authctxt); |
| 1800 | |
Damien Miller | 3a5b023 | 2002-03-13 13:19:42 +1100 | [diff] [blame] | 1801 | /* The connection has been terminated. */ |
| 1802 | verbose("Closing connection to %.100s", remote_ip); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1803 | |
Damien Miller | beb4ba5 | 1999-12-28 15:09:35 +1100 | [diff] [blame] | 1804 | #ifdef USE_PAM |
Damien Miller | 4e448a3 | 2003-05-14 15:11:48 +1000 | [diff] [blame] | 1805 | if (options.use_pam) |
| 1806 | finish_pam(); |
Damien Miller | beb4ba5 | 1999-12-28 15:09:35 +1100 | [diff] [blame] | 1807 | #endif /* USE_PAM */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1808 | |
Darren Tucker | 2b59a6d | 2005-03-06 22:38:51 +1100 | [diff] [blame] | 1809 | #ifdef SSH_AUDIT_EVENTS |
| 1810 | PRIVSEP(audit_event(SSH_CONNECTION_CLOSE)); |
| 1811 | #endif |
| 1812 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1813 | packet_close(); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1814 | |
| 1815 | if (use_privsep) |
| 1816 | mm_terminate(); |
| 1817 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1818 | exit(0); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1819 | } |
| 1820 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1821 | /* |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1822 | * Decrypt session_key_int using our private server key and private host key |
| 1823 | * (key with larger modulus first). |
| 1824 | */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1825 | int |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1826 | ssh1_session_key(BIGNUM *session_key_int) |
| 1827 | { |
| 1828 | int rsafail = 0; |
| 1829 | |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1830 | if (BN_cmp(sensitive_data.server_key->rsa->n, |
| 1831 | sensitive_data.ssh1_host_key->rsa->n) > 0) { |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1832 | /* Server key has bigger modulus. */ |
| 1833 | if (BN_num_bits(sensitive_data.server_key->rsa->n) < |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1834 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + |
| 1835 | SSH_KEY_BITS_RESERVED) { |
| 1836 | fatal("do_connection: %s: " |
| 1837 | "server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d", |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1838 | get_remote_ipaddr(), |
| 1839 | BN_num_bits(sensitive_data.server_key->rsa->n), |
| 1840 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), |
| 1841 | SSH_KEY_BITS_RESERVED); |
| 1842 | } |
| 1843 | if (rsa_private_decrypt(session_key_int, session_key_int, |
| 1844 | sensitive_data.server_key->rsa) <= 0) |
| 1845 | rsafail++; |
| 1846 | if (rsa_private_decrypt(session_key_int, session_key_int, |
| 1847 | sensitive_data.ssh1_host_key->rsa) <= 0) |
| 1848 | rsafail++; |
| 1849 | } else { |
| 1850 | /* Host key has bigger modulus (or they are equal). */ |
| 1851 | if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) < |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1852 | BN_num_bits(sensitive_data.server_key->rsa->n) + |
| 1853 | SSH_KEY_BITS_RESERVED) { |
| 1854 | fatal("do_connection: %s: " |
| 1855 | "host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d", |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1856 | get_remote_ipaddr(), |
| 1857 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), |
| 1858 | BN_num_bits(sensitive_data.server_key->rsa->n), |
| 1859 | SSH_KEY_BITS_RESERVED); |
| 1860 | } |
| 1861 | if (rsa_private_decrypt(session_key_int, session_key_int, |
| 1862 | sensitive_data.ssh1_host_key->rsa) < 0) |
| 1863 | rsafail++; |
| 1864 | if (rsa_private_decrypt(session_key_int, session_key_int, |
| 1865 | sensitive_data.server_key->rsa) < 0) |
| 1866 | rsafail++; |
| 1867 | } |
| 1868 | return (rsafail); |
| 1869 | } |
| 1870 | /* |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1871 | * SSH1 key exchange |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1872 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 1873 | static void |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1874 | do_ssh1_kex(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1875 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1876 | int i, len; |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 1877 | int rsafail = 0; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1878 | BIGNUM *session_key_int; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1879 | u_char session_key[SSH_SESSION_KEY_LENGTH]; |
| 1880 | u_char cookie[8]; |
| 1881 | u_int cipher_type, auth_mask, protocol_flags; |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 1882 | u_int32_t rnd = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1883 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1884 | /* |
| 1885 | * Generate check bytes that the client must send back in the user |
| 1886 | * packet in order for it to be accepted; this is used to defy ip |
| 1887 | * spoofing attacks. Note that this only works against somebody |
| 1888 | * doing IP spoofing from a remote machine; any machine on the local |
| 1889 | * network can still see outgoing packets and catch the random |
| 1890 | * cookie. This only affects rhosts authentication, and this is one |
| 1891 | * of the reasons why it is inherently insecure. |
| 1892 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1893 | for (i = 0; i < 8; i++) { |
| 1894 | if (i % 4 == 0) |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 1895 | rnd = arc4random(); |
| 1896 | cookie[i] = rnd & 0xff; |
| 1897 | rnd >>= 8; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1898 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1899 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1900 | /* |
| 1901 | * Send our public key. We include in the packet 64 bits of random |
| 1902 | * data that must be matched in the reply in order to prevent IP |
| 1903 | * spoofing. |
| 1904 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1905 | packet_start(SSH_SMSG_PUBLIC_KEY); |
| 1906 | for (i = 0; i < 8; i++) |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1907 | packet_put_char(cookie[i]); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1908 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1909 | /* Store our public server RSA key. */ |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1910 | packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n)); |
| 1911 | packet_put_bignum(sensitive_data.server_key->rsa->e); |
| 1912 | packet_put_bignum(sensitive_data.server_key->rsa->n); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1913 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1914 | /* Store our public host RSA key. */ |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1915 | packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); |
| 1916 | packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e); |
| 1917 | packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1918 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1919 | /* Put protocol flags. */ |
| 1920 | packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1921 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1922 | /* Declare which ciphers we support. */ |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1923 | packet_put_int(cipher_mask_ssh1(0)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1924 | |
| 1925 | /* Declare supported authentication types. */ |
| 1926 | auth_mask = 0; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1927 | if (options.rhosts_rsa_authentication) |
| 1928 | auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA; |
| 1929 | if (options.rsa_authentication) |
| 1930 | auth_mask |= 1 << SSH_AUTH_RSA; |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 1931 | if (options.challenge_response_authentication == 1) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1932 | auth_mask |= 1 << SSH_AUTH_TIS; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1933 | if (options.password_authentication) |
| 1934 | auth_mask |= 1 << SSH_AUTH_PASSWORD; |
| 1935 | packet_put_int(auth_mask); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1936 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1937 | /* Send the packet and wait for it to be sent. */ |
| 1938 | packet_send(); |
| 1939 | packet_write_wait(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1940 | |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1941 | debug("Sent %d bit server key and %d bit host key.", |
| 1942 | BN_num_bits(sensitive_data.server_key->rsa->n), |
| 1943 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1944 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1945 | /* Read clients reply (cipher type and session key). */ |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 1946 | packet_read_expect(SSH_CMSG_SESSION_KEY); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1947 | |
Damien Miller | 50945fa | 1999-12-09 10:31:37 +1100 | [diff] [blame] | 1948 | /* Get cipher type and check whether we accept this. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1949 | cipher_type = packet_get_char(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1950 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1951 | if (!(cipher_mask_ssh1(0) & (1 << cipher_type))) |
Damien Miller | 50945fa | 1999-12-09 10:31:37 +1100 | [diff] [blame] | 1952 | packet_disconnect("Warning: client selects unsupported cipher."); |
| 1953 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1954 | /* Get check bytes from the packet. These must match those we |
| 1955 | sent earlier with the public key packet. */ |
| 1956 | for (i = 0; i < 8; i++) |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1957 | if (cookie[i] != packet_get_char()) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1958 | packet_disconnect("IP Spoofing check bytes do not match."); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1959 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1960 | debug("Encryption type: %.200s", cipher_name(cipher_type)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1961 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1962 | /* Get the encrypted integer. */ |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 1963 | if ((session_key_int = BN_new()) == NULL) |
| 1964 | fatal("do_ssh1_kex: BN_new failed"); |
Damien Miller | d432ccf | 2002-01-22 23:14:44 +1100 | [diff] [blame] | 1965 | packet_get_bignum(session_key_int); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1966 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1967 | protocol_flags = packet_get_int(); |
| 1968 | packet_set_protocol_flags(protocol_flags); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 1969 | packet_check_eom(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1970 | |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1971 | /* Decrypt session_key_int using host/server keys */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1972 | rsafail = PRIVSEP(ssh1_session_key(session_key_int)); |
| 1973 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1974 | /* |
| 1975 | * Extract session key from the decrypted integer. The key is in the |
| 1976 | * least significant 256 bits of the integer; the first byte of the |
| 1977 | * key is in the highest bits. |
| 1978 | */ |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 1979 | if (!rsafail) { |
| 1980 | BN_mask_bits(session_key_int, sizeof(session_key) * 8); |
| 1981 | len = BN_num_bytes(session_key_int); |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 1982 | if (len < 0 || (u_int)len > sizeof(session_key)) { |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 1983 | error("do_connection: bad session key len from %s: " |
Ben Lindstrom | 31ca54a | 2001-02-09 02:11:24 +0000 | [diff] [blame] | 1984 | "session_key_int %d > sizeof(session_key) %lu", |
| 1985 | get_remote_ipaddr(), len, (u_long)sizeof(session_key)); |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 1986 | rsafail++; |
| 1987 | } else { |
| 1988 | memset(session_key, 0, sizeof(session_key)); |
| 1989 | BN_bn2bin(session_key_int, |
| 1990 | session_key + sizeof(session_key) - len); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 1991 | |
Darren Tucker | e14e005 | 2004-05-13 16:30:44 +1000 | [diff] [blame] | 1992 | derive_ssh1_session_id( |
Darren Tucker | fc95970 | 2004-07-17 16:12:08 +1000 | [diff] [blame] | 1993 | sensitive_data.ssh1_host_key->rsa->n, |
Darren Tucker | e14e005 | 2004-05-13 16:30:44 +1000 | [diff] [blame] | 1994 | sensitive_data.server_key->rsa->n, |
| 1995 | cookie, session_id); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 1996 | /* |
| 1997 | * Xor the first 16 bytes of the session key with the |
| 1998 | * session id. |
| 1999 | */ |
| 2000 | for (i = 0; i < 16; i++) |
| 2001 | session_key[i] ^= session_id[i]; |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 2002 | } |
| 2003 | } |
| 2004 | if (rsafail) { |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 2005 | int bytes = BN_num_bytes(session_key_int); |
Ben Lindstrom | 13c5d3b | 2002-02-26 18:00:48 +0000 | [diff] [blame] | 2006 | u_char *buf = xmalloc(bytes); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 2007 | MD5_CTX md; |
| 2008 | |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 2009 | logit("do_connection: generating a fake encryption key"); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 2010 | BN_bn2bin(session_key_int, buf); |
| 2011 | MD5_Init(&md); |
| 2012 | MD5_Update(&md, buf, bytes); |
| 2013 | MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); |
| 2014 | MD5_Final(session_key, &md); |
| 2015 | MD5_Init(&md); |
| 2016 | MD5_Update(&md, session_key, 16); |
| 2017 | MD5_Update(&md, buf, bytes); |
| 2018 | MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); |
| 2019 | MD5_Final(session_key + 16, &md); |
| 2020 | memset(buf, 0, bytes); |
| 2021 | xfree(buf); |
Ben Lindstrom | 941ac82 | 2001-03-05 06:25:23 +0000 | [diff] [blame] | 2022 | for (i = 0; i < 16; i++) |
| 2023 | session_id[i] = session_key[i] ^ session_key[i + 16]; |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 2024 | } |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 2025 | /* Destroy the private and public keys. No longer. */ |
Damien Miller | 3a5b023 | 2002-03-13 13:19:42 +1100 | [diff] [blame] | 2026 | destroy_sensitive_data(); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 2027 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 2028 | if (use_privsep) |
| 2029 | mm_ssh1_session_id(session_id); |
| 2030 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 2031 | /* Destroy the decrypted integer. It is no longer needed. */ |
| 2032 | BN_clear_free(session_key_int); |
| 2033 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2034 | /* Set the session key. From this on all communications will be encrypted. */ |
| 2035 | packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2036 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2037 | /* Destroy our copy of the session key. It is no longer needed. */ |
| 2038 | memset(session_key, 0, sizeof(session_key)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2039 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2040 | debug("Received session key; encryption turned on."); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2041 | |
Ben Lindstrom | f666fec | 2002-06-06 19:51:58 +0000 | [diff] [blame] | 2042 | /* Send an acknowledgment packet. Note that this packet is sent encrypted. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2043 | packet_start(SSH_SMSG_SUCCESS); |
| 2044 | packet_send(); |
| 2045 | packet_write_wait(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2046 | } |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2047 | |
| 2048 | /* |
| 2049 | * SSH2 key exchange: diffie-hellman-group1-sha1 |
| 2050 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 2051 | static void |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 2052 | do_ssh2_kex(void) |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2053 | { |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2054 | Kex *kex; |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2055 | |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 2056 | if (options.ciphers != NULL) { |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 2057 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 2058 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; |
| 2059 | } |
Damien Miller | a0ff466 | 2001-03-30 10:49:35 +1000 | [diff] [blame] | 2060 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
| 2061 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); |
| 2062 | myproposal[PROPOSAL_ENC_ALGS_STOC] = |
| 2063 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); |
| 2064 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 2065 | if (options.macs != NULL) { |
| 2066 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = |
| 2067 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; |
| 2068 | } |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 2069 | if (options.compression == COMP_NONE) { |
Ben Lindstrom | 23e0f66 | 2002-06-21 01:09:47 +0000 | [diff] [blame] | 2070 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
| 2071 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 2072 | } else if (options.compression == COMP_DELAYED) { |
| 2073 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
| 2074 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com"; |
Ben Lindstrom | 23e0f66 | 2002-06-21 01:09:47 +0000 | [diff] [blame] | 2075 | } |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 2076 | |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 2077 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types(); |
| 2078 | |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 2079 | /* start key exchange */ |
Ben Lindstrom | 238abf6 | 2001-04-04 17:52:53 +0000 | [diff] [blame] | 2080 | kex = kex_setup(myproposal); |
Damien Miller | 8e7fb33 | 2003-02-24 12:03:03 +1100 | [diff] [blame] | 2081 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; |
Damien Miller | f675fc4 | 2004-06-15 10:30:09 +1000 | [diff] [blame] | 2082 | kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; |
Damien Miller | 8e7fb33 | 2003-02-24 12:03:03 +1100 | [diff] [blame] | 2083 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; |
Damien Miller | a63128d | 2006-03-15 12:08:28 +1100 | [diff] [blame] | 2084 | kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 2085 | kex->server = 1; |
| 2086 | kex->client_version_string=client_version_string; |
| 2087 | kex->server_version_string=server_version_string; |
| 2088 | kex->load_host_key=&get_hostkey_by_type; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 2089 | kex->host_key_index=&get_hostkey_index; |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2090 | |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 2091 | xxx_kex = kex; |
| 2092 | |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 2093 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 2094 | |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 2095 | session_id2 = kex->session_id; |
| 2096 | session_id2_len = kex->session_id_len; |
| 2097 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 2098 | #ifdef DEBUG_KEXDH |
| 2099 | /* send 1st encrypted/maced/compressed message */ |
| 2100 | packet_start(SSH2_MSG_IGNORE); |
| 2101 | packet_put_cstring("markus"); |
| 2102 | packet_send(); |
| 2103 | packet_write_wait(); |
| 2104 | #endif |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 2105 | debug("KEX done"); |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2106 | } |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 2107 | |
| 2108 | /* server specific fatal cleanup */ |
| 2109 | void |
| 2110 | cleanup_exit(int i) |
| 2111 | { |
| 2112 | if (the_authctxt) |
| 2113 | do_cleanup(the_authctxt); |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 2114 | #ifdef SSH_AUDIT_EVENTS |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 2115 | /* done after do_cleanup so it can cancel the PAM auth 'thread' */ |
| 2116 | if (!use_privsep || mm_is_monitor()) |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 2117 | audit_event(SSH_CONNECTION_ABANDON); |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 2118 | #endif |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 2119 | _exit(i); |
| 2120 | } |