Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 1 | /* $OpenBSD: sshd.c,v 1.339 2006/07/22 20:48:23 stevesk 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 | f17883e | 2006-03-15 11:45:54 +1100 | [diff] [blame] | 48 | #ifdef HAVE_SYS_STAT_H |
| 49 | # include <sys/stat.h> |
| 50 | #endif |
| 51 | #include <sys/ioctl.h> |
Damien Miller | e3b60b5 | 2006-07-10 21:08:03 +1000 | [diff] [blame] | 52 | #include <sys/socket.h> |
Damien Miller | 9cf6d07 | 2006-03-15 11:29:24 +1100 | [diff] [blame] | 53 | #include <sys/wait.h> |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 54 | |
Darren Tucker | 3997249 | 2006-07-12 22:22:46 +1000 | [diff] [blame] | 55 | #include <errno.h> |
Damien Miller | 57cf638 | 2006-07-10 21:13:46 +1000 | [diff] [blame] | 56 | #include <fcntl.h> |
Damien Miller | b8fe89c | 2006-07-24 14:51:00 +1000 | [diff] [blame^] | 57 | #include <netdb.h> |
Damien Miller | 6645e7a | 2006-03-15 14:42:54 +1100 | [diff] [blame] | 58 | #ifdef HAVE_PATHS_H |
Damien Miller | 03e2003 | 2006-03-15 11:16:59 +1100 | [diff] [blame] | 59 | #include <paths.h> |
Damien Miller | 6645e7a | 2006-03-15 14:42:54 +1100 | [diff] [blame] | 60 | #endif |
Damien Miller | a1738e4 | 2006-07-10 21:33:04 +1000 | [diff] [blame] | 61 | #include <grp.h> |
Damien Miller | 9f2abc4 | 2006-07-10 20:53:08 +1000 | [diff] [blame] | 62 | #include <pwd.h> |
Damien Miller | 6ff3cad | 2006-03-15 11:52:09 +1100 | [diff] [blame] | 63 | #include <signal.h> |
Damien Miller | e3476ed | 2006-07-24 14:13:33 +1000 | [diff] [blame] | 64 | #include <string.h> |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 65 | |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 66 | #include <openssl/dh.h> |
| 67 | #include <openssl/bn.h> |
Damien Miller | 6a47f30 | 2002-02-13 13:55:06 +1100 | [diff] [blame] | 68 | #include <openssl/md5.h> |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 69 | #include <openssl/rand.h> |
Kevin Steves | 0ea1d9d | 2002-04-25 18:17:04 +0000 | [diff] [blame] | 70 | #ifdef HAVE_SECUREWARE |
| 71 | #include <sys/security.h> |
| 72 | #include <prot.h> |
| 73 | #endif |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 74 | |
| 75 | #include "ssh.h" |
| 76 | #include "ssh1.h" |
| 77 | #include "ssh2.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 78 | #include "xmalloc.h" |
| 79 | #include "rsa.h" |
Ben Lindstrom | d95c09c | 2001-02-18 19:13:33 +0000 | [diff] [blame] | 80 | #include "sshpty.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 81 | #include "packet.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 82 | #include "log.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 83 | #include "servconf.h" |
| 84 | #include "uidswap.h" |
| 85 | #include "compat.h" |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 86 | #include "buffer.h" |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 87 | #include "bufaux.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 88 | #include "cipher.h" |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 89 | #include "kex.h" |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 90 | #include "key.h" |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 91 | #include "dh.h" |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 92 | #include "myproposal.h" |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 93 | #include "authfile.h" |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 94 | #include "pathnames.h" |
| 95 | #include "atomicio.h" |
| 96 | #include "canohost.h" |
| 97 | #include "auth.h" |
| 98 | #include "misc.h" |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 99 | #include "msg.h" |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 100 | #include "dispatch.h" |
Ben Lindstrom | 1bae404 | 2001-10-03 17:46:39 +0000 | [diff] [blame] | 101 | #include "channels.h" |
Ben Lindstrom | 73ab9ba | 2002-03-22 01:27:35 +0000 | [diff] [blame] | 102 | #include "session.h" |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 103 | #include "monitor_mm.h" |
| 104 | #include "monitor.h" |
| 105 | #include "monitor_wrap.h" |
| 106 | #include "monitor_fdpass.h" |
Damien Miller | b757677 | 2006-07-10 20:23:39 +1000 | [diff] [blame] | 107 | #include "version.h" |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 108 | |
| 109 | #ifdef LIBWRAP |
| 110 | #include <tcpd.h> |
| 111 | #include <syslog.h> |
| 112 | int allow_severity = LOG_INFO; |
| 113 | int deny_severity = LOG_WARNING; |
| 114 | #endif /* LIBWRAP */ |
| 115 | |
| 116 | #ifndef O_NOCTTY |
| 117 | #define O_NOCTTY 0 |
| 118 | #endif |
| 119 | |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 120 | /* Re-exec fds */ |
| 121 | #define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1) |
| 122 | #define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2) |
| 123 | #define REEXEC_CONFIG_PASS_FD (STDERR_FILENO + 3) |
| 124 | #define REEXEC_MIN_FREE_FD (STDERR_FILENO + 4) |
| 125 | |
Ben Lindstrom | 49a79c0 | 2000-11-17 03:47:20 +0000 | [diff] [blame] | 126 | extern char *__progname; |
Ben Lindstrom | 49a79c0 | 2000-11-17 03:47:20 +0000 | [diff] [blame] | 127 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 128 | /* Server configuration options. */ |
| 129 | ServerOptions options; |
| 130 | |
| 131 | /* Name of the server configuration file. */ |
Ben Lindstrom | 226cfa0 | 2001-01-22 05:34:40 +0000 | [diff] [blame] | 132 | char *config_file_name = _PATH_SERVER_CONFIG_FILE; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 133 | |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 134 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 135 | * Debug mode flag. This can be set on the command line. If debug |
| 136 | * mode is enabled, extra debugging output will be sent to the system |
| 137 | * log, the daemon will not go to background, and will exit after processing |
| 138 | * the first connection. |
| 139 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 140 | int debug_flag = 0; |
| 141 | |
Ben Lindstrom | 794325a | 2001-08-06 21:09:07 +0000 | [diff] [blame] | 142 | /* Flag indicating that the daemon should only test the configuration and keys. */ |
| 143 | int test_flag = 0; |
| 144 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 145 | /* Flag indicating that the daemon is being started from inetd. */ |
| 146 | int inetd_flag = 0; |
| 147 | |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 148 | /* Flag indicating that sshd should not detach and become a daemon. */ |
| 149 | int no_daemon_flag = 0; |
| 150 | |
Damien Miller | 5ce662a | 1999-11-11 17:57:39 +1100 | [diff] [blame] | 151 | /* debug goes to stderr unless inetd_flag is set */ |
| 152 | int log_stderr = 0; |
| 153 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 154 | /* Saved arguments to main(). */ |
| 155 | char **saved_argv; |
Damien Miller | b8c656e | 2000-06-28 15:22:41 +1000 | [diff] [blame] | 156 | int saved_argc; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 157 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 158 | /* re-exec */ |
| 159 | int rexeced_flag = 0; |
| 160 | int rexec_flag = 1; |
| 161 | int rexec_argc = 0; |
| 162 | char **rexec_argv; |
| 163 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 164 | /* |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 165 | * The sockets that the server is listening; this is used in the SIGHUP |
| 166 | * signal handler. |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 167 | */ |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 168 | #define MAX_LISTEN_SOCKS 16 |
| 169 | int listen_socks[MAX_LISTEN_SOCKS]; |
| 170 | int num_listen_socks = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 171 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 172 | /* |
| 173 | * the client's version string, passed by sshd2 in compat mode. if != NULL, |
| 174 | * sshd will skip the version-number exchange |
| 175 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 176 | char *client_version_string = NULL; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 177 | char *server_version_string = NULL; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 178 | |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 179 | /* for rekeying XXX fixme */ |
| 180 | Kex *xxx_kex; |
| 181 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 182 | /* |
| 183 | * Any really sensitive data in the application is contained in this |
| 184 | * structure. The idea is that this structure could be locked into memory so |
| 185 | * that the pages do not get written into swap. However, there are some |
| 186 | * problems. The private key contains BIGNUMs, and we do not (in principle) |
| 187 | * have access to the internals of them, and locking just the structure is |
| 188 | * not very useful. Currently, memory locking is not implemented. |
| 189 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 190 | struct { |
Ben Lindstrom | ca42d5f | 2001-03-09 18:25:32 +0000 | [diff] [blame] | 191 | Key *server_key; /* ephemeral server key */ |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 192 | Key *ssh1_host_key; /* ssh1 host key */ |
| 193 | Key **host_keys; /* all private host keys */ |
| 194 | int have_ssh1_key; |
| 195 | int have_ssh2_key; |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 196 | u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH]; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 197 | } sensitive_data; |
| 198 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 199 | /* |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 200 | * Flag indicating whether the RSA server key needs to be regenerated. |
| 201 | * 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] | 202 | */ |
Ben Lindstrom | 5e71c54 | 2001-12-06 16:48:14 +0000 | [diff] [blame] | 203 | static volatile sig_atomic_t key_do_regen = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 204 | |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 205 | /* This is set to true when a signal is received. */ |
Ben Lindstrom | 5e71c54 | 2001-12-06 16:48:14 +0000 | [diff] [blame] | 206 | static volatile sig_atomic_t received_sighup = 0; |
| 207 | static volatile sig_atomic_t received_sigterm = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 208 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 209 | /* session identifier, used by RSA-auth */ |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 210 | u_char session_id[16]; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 211 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 212 | /* same for ssh2 */ |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 213 | u_char *session_id2 = NULL; |
Darren Tucker | 502d384 | 2003-06-28 12:38:01 +1000 | [diff] [blame] | 214 | u_int session_id2_len = 0; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 215 | |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 216 | /* record remote hostname or ip */ |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 217 | u_int utmp_len = MAXHOSTNAMELEN; |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 218 | |
Ben Lindstrom | d84df98 | 2001-12-06 16:35:40 +0000 | [diff] [blame] | 219 | /* options.max_startup sized array of fd ints */ |
| 220 | int *startup_pipes = NULL; |
| 221 | int startup_pipe; /* in child */ |
| 222 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 223 | /* variables used for privilege separation */ |
Darren Tucker | 4515047 | 2006-07-12 22:34:17 +1000 | [diff] [blame] | 224 | int use_privsep = -1; |
Darren Tucker | a8be9e2 | 2004-02-06 16:40:27 +1100 | [diff] [blame] | 225 | struct monitor *pmonitor = NULL; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 226 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 227 | /* global authentication context */ |
| 228 | Authctxt *the_authctxt = NULL; |
| 229 | |
Darren Tucker | 4515047 | 2006-07-12 22:34:17 +1000 | [diff] [blame] | 230 | /* sshd_config buffer */ |
| 231 | Buffer cfg; |
| 232 | |
Darren Tucker | 0999174 | 2004-07-17 17:05:14 +1000 | [diff] [blame] | 233 | /* message to be displayed after login */ |
| 234 | Buffer loginmsg; |
| 235 | |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 236 | /* Prototypes for various functions defined later in this file. */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 237 | void destroy_sensitive_data(void); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 238 | void demote_sensitive_data(void); |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 239 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 240 | static void do_ssh1_kex(void); |
| 241 | static void do_ssh2_kex(void); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 242 | |
Damien Miller | 98c7ad6 | 2000-03-09 21:27:49 +1100 | [diff] [blame] | 243 | /* |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 244 | * Close all listening sockets |
| 245 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 246 | static void |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 247 | close_listen_socks(void) |
| 248 | { |
| 249 | int i; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 250 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 251 | for (i = 0; i < num_listen_socks; i++) |
| 252 | close(listen_socks[i]); |
| 253 | num_listen_socks = -1; |
| 254 | } |
| 255 | |
Ben Lindstrom | d84df98 | 2001-12-06 16:35:40 +0000 | [diff] [blame] | 256 | static void |
| 257 | close_startup_pipes(void) |
| 258 | { |
| 259 | int i; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 260 | |
Ben Lindstrom | d84df98 | 2001-12-06 16:35:40 +0000 | [diff] [blame] | 261 | if (startup_pipes) |
| 262 | for (i = 0; i < options.max_startups; i++) |
| 263 | if (startup_pipes[i] != -1) |
| 264 | close(startup_pipes[i]); |
| 265 | } |
| 266 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 267 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 268 | * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP; |
| 269 | * the effect is to reread the configuration file (and to regenerate |
| 270 | * the server key). |
| 271 | */ |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 272 | |
| 273 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 274 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 275 | sighup_handler(int sig) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 276 | { |
Ben Lindstrom | 0795848 | 2001-12-06 16:19:01 +0000 | [diff] [blame] | 277 | int save_errno = errno; |
| 278 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 279 | received_sighup = 1; |
| 280 | signal(SIGHUP, sighup_handler); |
Ben Lindstrom | 0795848 | 2001-12-06 16:19:01 +0000 | [diff] [blame] | 281 | errno = save_errno; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 282 | } |
| 283 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 284 | /* |
| 285 | * Called from the main program after receiving SIGHUP. |
| 286 | * Restarts the server. |
| 287 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 288 | static void |
Ben Lindstrom | 31ca54a | 2001-02-09 02:11:24 +0000 | [diff] [blame] | 289 | sighup_restart(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 290 | { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 291 | logit("Received SIGHUP; restarting."); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 292 | close_listen_socks(); |
Ben Lindstrom | d84df98 | 2001-12-06 16:35:40 +0000 | [diff] [blame] | 293 | close_startup_pipes(); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 294 | execv(saved_argv[0], saved_argv); |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 295 | logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0], |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 296 | strerror(errno)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 297 | exit(1); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 298 | } |
| 299 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 300 | /* |
| 301 | * Generic signal handler for terminating signals in the master daemon. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 302 | */ |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 303 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 304 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 305 | sigterm_handler(int sig) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 306 | { |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 307 | received_sigterm = sig; |
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 | * SIGCHLD handler. This is called whenever a child dies. This will then |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 312 | * reap any zombies left by exited children. |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 313 | */ |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 314 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 315 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 316 | main_sigchld_handler(int sig) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 317 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 318 | int save_errno = errno; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 319 | pid_t pid; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 320 | int status; |
Damien Miller | 431f66b | 1999-11-21 18:31:57 +1100 | [diff] [blame] | 321 | |
Ben Lindstrom | 47fd811 | 2002-04-02 20:48:19 +0000 | [diff] [blame] | 322 | while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || |
| 323 | (pid < 0 && errno == EINTR)) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 324 | ; |
Damien Miller | 431f66b | 1999-11-21 18:31:57 +1100 | [diff] [blame] | 325 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 326 | signal(SIGCHLD, main_sigchld_handler); |
| 327 | errno = save_errno; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 328 | } |
| 329 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 330 | /* |
| 331 | * Signal handler for the alarm after the login grace period has expired. |
| 332 | */ |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 333 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 334 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 335 | grace_alarm_handler(int sig) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 336 | { |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 337 | /* XXX no idea how fix this signal handler */ |
| 338 | |
Darren Tucker | a8be9e2 | 2004-02-06 16:40:27 +1100 | [diff] [blame] | 339 | if (use_privsep && pmonitor != NULL && pmonitor->m_pid > 0) |
| 340 | kill(pmonitor->m_pid, SIGALRM); |
| 341 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 342 | /* Log error and exit. */ |
Damien Miller | d27a76d | 2002-09-27 13:22:31 +1000 | [diff] [blame] | 343 | fatal("Timeout before authentication for %s", get_remote_ipaddr()); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 344 | } |
| 345 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 346 | /* |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 347 | * Signal handler for the key regeneration alarm. Note that this |
| 348 | * alarm only occurs in the daemon waiting for connections, and it does not |
| 349 | * do anything with the private key or random state before forking. |
| 350 | * Thus there should be no concurrency control/asynchronous execution |
| 351 | * problems. |
| 352 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 353 | static void |
Ben Lindstrom | ca42d5f | 2001-03-09 18:25:32 +0000 | [diff] [blame] | 354 | generate_ephemeral_server_key(void) |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 355 | { |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 356 | u_int32_t rnd = 0; |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 357 | int i; |
| 358 | |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 359 | verbose("Generating %s%d bit RSA key.", |
Damien Miller | ff75ac4 | 2001-03-30 10:50:32 +1000 | [diff] [blame] | 360 | sensitive_data.server_key ? "new " : "", options.server_key_bits); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 361 | if (sensitive_data.server_key != NULL) |
| 362 | key_free(sensitive_data.server_key); |
Ben Lindstrom | a370005 | 2001-04-05 23:26:32 +0000 | [diff] [blame] | 363 | sensitive_data.server_key = key_generate(KEY_RSA1, |
Damien Miller | ff75ac4 | 2001-03-30 10:50:32 +1000 | [diff] [blame] | 364 | options.server_key_bits); |
| 365 | verbose("RSA key generation complete."); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 366 | |
| 367 | for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) { |
| 368 | if (i % 4 == 0) |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 369 | rnd = arc4random(); |
| 370 | sensitive_data.ssh1_cookie[i] = rnd & 0xff; |
| 371 | rnd >>= 8; |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 372 | } |
| 373 | arc4random_stir(); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 374 | } |
Ben Lindstrom | 2f959b4 | 2001-01-11 06:20:23 +0000 | [diff] [blame] | 375 | |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 376 | /*ARGSUSED*/ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 377 | static void |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 378 | key_regeneration_alarm(int sig) |
| 379 | { |
| 380 | int save_errno = errno; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 381 | |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 382 | signal(SIGALRM, SIG_DFL); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 383 | errno = save_errno; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 384 | key_do_regen = 1; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 385 | } |
| 386 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 387 | static void |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 388 | sshd_exchange_identification(int sock_in, int sock_out) |
| 389 | { |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 390 | u_int i; |
| 391 | int mismatch; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 392 | int remote_major, remote_minor; |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 393 | int major, minor; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 394 | char *s; |
| 395 | char buf[256]; /* Must not be larger than remote_version. */ |
| 396 | char remote_version[256]; /* Must be at least as big as buf. */ |
| 397 | |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 398 | if ((options.protocol & SSH_PROTO_1) && |
| 399 | (options.protocol & SSH_PROTO_2)) { |
| 400 | major = PROTOCOL_MAJOR_1; |
| 401 | minor = 99; |
| 402 | } else if (options.protocol & SSH_PROTO_2) { |
| 403 | major = PROTOCOL_MAJOR_2; |
| 404 | minor = PROTOCOL_MINOR_2; |
| 405 | } else { |
| 406 | major = PROTOCOL_MAJOR_1; |
| 407 | minor = PROTOCOL_MINOR_1; |
| 408 | } |
| 409 | 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] | 410 | server_version_string = xstrdup(buf); |
| 411 | |
Darren Tucker | fe0078a | 2003-07-19 19:52:28 +1000 | [diff] [blame] | 412 | /* Send our protocol version identification. */ |
| 413 | if (atomicio(vwrite, sock_out, server_version_string, |
| 414 | strlen(server_version_string)) |
| 415 | != strlen(server_version_string)) { |
| 416 | logit("Could not write ident string to %s", get_remote_ipaddr()); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 417 | cleanup_exit(255); |
Darren Tucker | fe0078a | 2003-07-19 19:52:28 +1000 | [diff] [blame] | 418 | } |
| 419 | |
| 420 | /* Read other sides version identification. */ |
| 421 | memset(buf, 0, sizeof(buf)); |
| 422 | for (i = 0; i < sizeof(buf) - 1; i++) { |
| 423 | if (atomicio(read, sock_in, &buf[i], 1) != 1) { |
| 424 | logit("Did not receive identification string from %s", |
| 425 | get_remote_ipaddr()); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 426 | cleanup_exit(255); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 427 | } |
Darren Tucker | fe0078a | 2003-07-19 19:52:28 +1000 | [diff] [blame] | 428 | if (buf[i] == '\r') { |
| 429 | buf[i] = 0; |
| 430 | /* Kludge for F-Secure Macintosh < 1.0.2 */ |
| 431 | if (i == 12 && |
| 432 | strncmp(buf, "SSH-1.5-W1.0", 12) == 0) |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 433 | break; |
Darren Tucker | fe0078a | 2003-07-19 19:52:28 +1000 | [diff] [blame] | 434 | continue; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 435 | } |
Darren Tucker | fe0078a | 2003-07-19 19:52:28 +1000 | [diff] [blame] | 436 | if (buf[i] == '\n') { |
| 437 | buf[i] = 0; |
| 438 | break; |
| 439 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 440 | } |
Darren Tucker | fe0078a | 2003-07-19 19:52:28 +1000 | [diff] [blame] | 441 | buf[sizeof(buf) - 1] = 0; |
| 442 | client_version_string = xstrdup(buf); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 443 | |
| 444 | /* |
| 445 | * Check that the versions match. In future this might accept |
| 446 | * several versions and set appropriate flags to handle them. |
| 447 | */ |
| 448 | if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n", |
| 449 | &remote_major, &remote_minor, remote_version) != 3) { |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 450 | s = "Protocol mismatch.\n"; |
Darren Tucker | 9f63f22 | 2003-07-03 13:46:56 +1000 | [diff] [blame] | 451 | (void) atomicio(vwrite, sock_out, s, strlen(s)); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 452 | close(sock_in); |
| 453 | close(sock_out); |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 454 | logit("Bad protocol version identification '%.100s' from %s", |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 455 | client_version_string, get_remote_ipaddr()); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 456 | cleanup_exit(255); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 457 | } |
| 458 | debug("Client protocol version %d.%d; client software version %.100s", |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 459 | remote_major, remote_minor, remote_version); |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 460 | |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 461 | compat_datafellows(remote_version); |
| 462 | |
Damien Miller | e926497 | 2002-09-30 11:59:21 +1000 | [diff] [blame] | 463 | if (datafellows & SSH_BUG_PROBE) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 464 | logit("probed from %s with %s. Don't panic.", |
Damien Miller | e926497 | 2002-09-30 11:59:21 +1000 | [diff] [blame] | 465 | get_remote_ipaddr(), client_version_string); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 466 | cleanup_exit(255); |
Damien Miller | e926497 | 2002-09-30 11:59:21 +1000 | [diff] [blame] | 467 | } |
| 468 | |
Damien Miller | 27dbe6f | 2001-03-19 22:36:20 +1100 | [diff] [blame] | 469 | if (datafellows & SSH_BUG_SCANNER) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 470 | logit("scanned from %s with %s. Don't panic.", |
Damien Miller | 27dbe6f | 2001-03-19 22:36:20 +1100 | [diff] [blame] | 471 | get_remote_ipaddr(), client_version_string); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 472 | cleanup_exit(255); |
Damien Miller | 27dbe6f | 2001-03-19 22:36:20 +1100 | [diff] [blame] | 473 | } |
| 474 | |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 475 | mismatch = 0; |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 476 | switch (remote_major) { |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 477 | case 1: |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 478 | if (remote_minor == 99) { |
| 479 | if (options.protocol & SSH_PROTO_2) |
| 480 | enable_compat20(); |
| 481 | else |
| 482 | mismatch = 1; |
| 483 | break; |
| 484 | } |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 485 | if (!(options.protocol & SSH_PROTO_1)) { |
| 486 | mismatch = 1; |
| 487 | break; |
| 488 | } |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 489 | if (remote_minor < 3) { |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 490 | packet_disconnect("Your ssh version is too old and " |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 491 | "is no longer supported. Please install a newer version."); |
| 492 | } else if (remote_minor == 3) { |
| 493 | /* note that this disables agent-forwarding */ |
| 494 | enable_compat13(); |
| 495 | } |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 496 | break; |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 497 | case 2: |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 498 | if (options.protocol & SSH_PROTO_2) { |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 499 | enable_compat20(); |
| 500 | break; |
| 501 | } |
| 502 | /* FALLTHROUGH */ |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 503 | default: |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 504 | mismatch = 1; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 505 | break; |
| 506 | } |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 507 | chop(server_version_string); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 508 | debug("Local version string %.200s", server_version_string); |
| 509 | |
| 510 | if (mismatch) { |
| 511 | s = "Protocol major versions differ.\n"; |
Darren Tucker | 9f63f22 | 2003-07-03 13:46:56 +1000 | [diff] [blame] | 512 | (void) atomicio(vwrite, sock_out, s, strlen(s)); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 513 | close(sock_in); |
| 514 | close(sock_out); |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 515 | logit("Protocol major versions differ for %s: %.200s vs. %.200s", |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 516 | get_remote_ipaddr(), |
| 517 | server_version_string, client_version_string); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 518 | cleanup_exit(255); |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 519 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 520 | } |
| 521 | |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 522 | /* Destroy the host and server keys. They will no longer be needed. */ |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 523 | void |
| 524 | destroy_sensitive_data(void) |
| 525 | { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 526 | int i; |
| 527 | |
| 528 | if (sensitive_data.server_key) { |
| 529 | key_free(sensitive_data.server_key); |
| 530 | sensitive_data.server_key = NULL; |
| 531 | } |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 532 | for (i = 0; i < options.num_host_key_files; i++) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 533 | if (sensitive_data.host_keys[i]) { |
| 534 | key_free(sensitive_data.host_keys[i]); |
| 535 | sensitive_data.host_keys[i] = NULL; |
| 536 | } |
| 537 | } |
| 538 | sensitive_data.ssh1_host_key = NULL; |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 539 | memset(sensitive_data.ssh1_cookie, 0, SSH_SESSION_KEY_LENGTH); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 540 | } |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 541 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 542 | /* Demote private to public keys for network child */ |
| 543 | void |
| 544 | demote_sensitive_data(void) |
| 545 | { |
| 546 | Key *tmp; |
| 547 | int i; |
| 548 | |
| 549 | if (sensitive_data.server_key) { |
| 550 | tmp = key_demote(sensitive_data.server_key); |
| 551 | key_free(sensitive_data.server_key); |
| 552 | sensitive_data.server_key = tmp; |
| 553 | } |
| 554 | |
| 555 | for (i = 0; i < options.num_host_key_files; i++) { |
| 556 | if (sensitive_data.host_keys[i]) { |
| 557 | tmp = key_demote(sensitive_data.host_keys[i]); |
| 558 | key_free(sensitive_data.host_keys[i]); |
| 559 | sensitive_data.host_keys[i] = tmp; |
| 560 | if (tmp->type == KEY_RSA1) |
| 561 | sensitive_data.ssh1_host_key = tmp; |
| 562 | } |
| 563 | } |
| 564 | |
| 565 | /* We do not clear ssh1_host key and cookie. XXX - Okay Niels? */ |
| 566 | } |
| 567 | |
Ben Lindstrom | 0810519 | 2002-03-22 02:50:06 +0000 | [diff] [blame] | 568 | static void |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 569 | privsep_preauth_child(void) |
| 570 | { |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 571 | u_int32_t rnd[256]; |
Ben Lindstrom | 810af96 | 2002-07-04 00:11:40 +0000 | [diff] [blame] | 572 | gid_t gidset[1]; |
Ben Lindstrom | c743134 | 2002-03-22 03:11:49 +0000 | [diff] [blame] | 573 | struct passwd *pw; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 574 | int i; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 575 | |
| 576 | /* Enable challenge-response authentication for privilege separation */ |
| 577 | privsep_challenge_enable(); |
| 578 | |
| 579 | for (i = 0; i < 256; i++) |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 580 | rnd[i] = arc4random(); |
| 581 | RAND_seed(rnd, sizeof(rnd)); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 582 | |
| 583 | /* Demote the private keys to public keys. */ |
| 584 | demote_sensitive_data(); |
| 585 | |
Ben Lindstrom | c743134 | 2002-03-22 03:11:49 +0000 | [diff] [blame] | 586 | if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL) |
Damien Miller | 0150c65 | 2002-04-24 09:49:09 +1000 | [diff] [blame] | 587 | fatal("Privilege separation user %s does not exist", |
| 588 | SSH_PRIVSEP_USER); |
Ben Lindstrom | c743134 | 2002-03-22 03:11:49 +0000 | [diff] [blame] | 589 | memset(pw->pw_passwd, 0, strlen(pw->pw_passwd)); |
| 590 | endpwent(); |
| 591 | |
Ben Lindstrom | a962c2f | 2002-07-04 00:14:17 +0000 | [diff] [blame] | 592 | /* Change our root directory */ |
Ben Lindstrom | 7a7edf7 | 2002-03-22 02:42:37 +0000 | [diff] [blame] | 593 | if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1) |
| 594 | fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR, |
| 595 | strerror(errno)); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 596 | if (chdir("/") == -1) |
Ben Lindstrom | 1ee9ec3 | 2002-03-22 03:14:45 +0000 | [diff] [blame] | 597 | fatal("chdir(\"/\"): %s", strerror(errno)); |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 598 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 599 | /* Drop our privileges */ |
Ben Lindstrom | c743134 | 2002-03-22 03:11:49 +0000 | [diff] [blame] | 600 | debug3("privsep user:group %u:%u", (u_int)pw->pw_uid, |
| 601 | (u_int)pw->pw_gid); |
Ben Lindstrom | fbcc3f7 | 2002-06-25 23:24:18 +0000 | [diff] [blame] | 602 | #if 0 |
Darren Tucker | d592048 | 2004-02-29 20:11:30 +1100 | [diff] [blame] | 603 | /* XXX not ready, too heavy after chroot */ |
Ben Lindstrom | c743134 | 2002-03-22 03:11:49 +0000 | [diff] [blame] | 604 | do_setusercontext(pw); |
Ben Lindstrom | fbcc3f7 | 2002-06-25 23:24:18 +0000 | [diff] [blame] | 605 | #else |
| 606 | gidset[0] = pw->pw_gid; |
Ben Lindstrom | fbcc3f7 | 2002-06-25 23:24:18 +0000 | [diff] [blame] | 607 | if (setgroups(1, gidset) < 0) |
| 608 | fatal("setgroups: %.100s", strerror(errno)); |
| 609 | permanently_set_uid(pw); |
| 610 | #endif |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 611 | } |
| 612 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 613 | static int |
| 614 | privsep_preauth(Authctxt *authctxt) |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 615 | { |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 616 | int status; |
| 617 | pid_t pid; |
| 618 | |
| 619 | /* Set up unprivileged child process to deal with network data */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 620 | pmonitor = monitor_init(); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 621 | /* Store a pointer to the kex for later rekeying */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 622 | pmonitor->m_pkex = &xxx_kex; |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 623 | |
| 624 | pid = fork(); |
| 625 | if (pid == -1) { |
| 626 | fatal("fork of unprivileged child failed"); |
| 627 | } else if (pid != 0) { |
Ben Lindstrom | ce0f634 | 2002-06-11 16:42:49 +0000 | [diff] [blame] | 628 | debug2("Network child is on pid %ld", (long)pid); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 629 | |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 630 | close(pmonitor->m_recvfd); |
Darren Tucker | a8be9e2 | 2004-02-06 16:40:27 +1100 | [diff] [blame] | 631 | pmonitor->m_pid = pid; |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 632 | monitor_child_preauth(authctxt, pmonitor); |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 633 | close(pmonitor->m_sendfd); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 634 | |
| 635 | /* Sync memory */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 636 | monitor_sync(pmonitor); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 637 | |
| 638 | /* Wait for the child's exit status */ |
Ben Lindstrom | 47fd811 | 2002-04-02 20:48:19 +0000 | [diff] [blame] | 639 | while (waitpid(pid, &status, 0) < 0) |
| 640 | if (errno != EINTR) |
| 641 | break; |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 642 | return (1); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 643 | } else { |
| 644 | /* child */ |
| 645 | |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 646 | close(pmonitor->m_sendfd); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 647 | |
| 648 | /* Demote the child */ |
| 649 | if (getuid() == 0 || geteuid() == 0) |
| 650 | privsep_preauth_child(); |
Ben Lindstrom | f90f58d | 2002-03-26 01:53:03 +0000 | [diff] [blame] | 651 | setproctitle("%s", "[net]"); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 652 | } |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 653 | return (0); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 654 | } |
| 655 | |
Ben Lindstrom | 0810519 | 2002-03-22 02:50:06 +0000 | [diff] [blame] | 656 | static void |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 657 | privsep_postauth(Authctxt *authctxt) |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 658 | { |
Tim Rice | 9dd3081 | 2002-07-07 13:43:36 -0700 | [diff] [blame] | 659 | #ifdef DISABLE_FD_PASSING |
Tim Rice | 8eff319 | 2002-06-25 15:35:15 -0700 | [diff] [blame] | 660 | if (1) { |
| 661 | #else |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 662 | if (authctxt->pw->pw_uid == 0 || options.use_login) { |
Tim Rice | 8eff319 | 2002-06-25 15:35:15 -0700 | [diff] [blame] | 663 | #endif |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 664 | /* File descriptor passing is broken or root login */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 665 | use_privsep = 0; |
Darren Tucker | 45b0142 | 2005-10-03 18:20:00 +1000 | [diff] [blame] | 666 | goto skip; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 667 | } |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 668 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 669 | /* New socket pair */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 670 | monitor_reinit(pmonitor); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 671 | |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 672 | pmonitor->m_pid = fork(); |
| 673 | if (pmonitor->m_pid == -1) |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 674 | fatal("fork of unprivileged child failed"); |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 675 | else if (pmonitor->m_pid != 0) { |
Ben Lindstrom | ce0f634 | 2002-06-11 16:42:49 +0000 | [diff] [blame] | 676 | debug2("User child is on pid %ld", (long)pmonitor->m_pid); |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 677 | close(pmonitor->m_recvfd); |
Darren Tucker | eb57862 | 2004-08-12 23:08:14 +1000 | [diff] [blame] | 678 | buffer_clear(&loginmsg); |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 679 | monitor_child_postauth(pmonitor); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 680 | |
| 681 | /* NEVERREACHED */ |
| 682 | exit(0); |
| 683 | } |
| 684 | |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 685 | close(pmonitor->m_sendfd); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 686 | |
| 687 | /* Demote the private keys to public keys. */ |
| 688 | demote_sensitive_data(); |
| 689 | |
| 690 | /* Drop privileges */ |
| 691 | do_setusercontext(authctxt->pw); |
| 692 | |
Darren Tucker | 45b0142 | 2005-10-03 18:20:00 +1000 | [diff] [blame] | 693 | skip: |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 694 | /* It is safe now to apply the key state */ |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 695 | monitor_apply_keystate(pmonitor); |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 696 | |
| 697 | /* |
| 698 | * Tell the packet layer that authentication was successful, since |
| 699 | * this information is not part of the key state. |
| 700 | */ |
| 701 | packet_set_authenticated(); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 702 | } |
| 703 | |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 704 | static char * |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 705 | list_hostkey_types(void) |
| 706 | { |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 707 | Buffer b; |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 708 | const char *p; |
| 709 | char *ret; |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 710 | int i; |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 711 | |
| 712 | buffer_init(&b); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 713 | for (i = 0; i < options.num_host_key_files; i++) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 714 | Key *key = sensitive_data.host_keys[i]; |
| 715 | if (key == NULL) |
| 716 | continue; |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 717 | switch (key->type) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 718 | case KEY_RSA: |
| 719 | case KEY_DSA: |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 720 | if (buffer_len(&b) > 0) |
| 721 | buffer_append(&b, ",", 1); |
| 722 | p = key_ssh_name(key); |
| 723 | buffer_append(&b, p, strlen(p)); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 724 | break; |
| 725 | } |
| 726 | } |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 727 | buffer_append(&b, "\0", 1); |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 728 | ret = xstrdup(buffer_ptr(&b)); |
Damien Miller | 0e3b872 | 2002-01-22 23:26:38 +1100 | [diff] [blame] | 729 | buffer_free(&b); |
Damien Miller | f58b58c | 2003-11-17 21:18:23 +1100 | [diff] [blame] | 730 | debug("list_hostkey_types: %s", ret); |
| 731 | return ret; |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 732 | } |
| 733 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 734 | Key * |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 735 | get_hostkey_by_type(int type) |
| 736 | { |
| 737 | int i; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 738 | |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 739 | for (i = 0; i < options.num_host_key_files; i++) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 740 | Key *key = sensitive_data.host_keys[i]; |
| 741 | if (key != NULL && key->type == type) |
| 742 | return key; |
| 743 | } |
| 744 | return NULL; |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 745 | } |
| 746 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 747 | Key * |
| 748 | get_hostkey_by_index(int ind) |
| 749 | { |
| 750 | if (ind < 0 || ind >= options.num_host_key_files) |
| 751 | return (NULL); |
| 752 | return (sensitive_data.host_keys[ind]); |
| 753 | } |
| 754 | |
| 755 | int |
| 756 | get_hostkey_index(Key *key) |
| 757 | { |
| 758 | int i; |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 759 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 760 | for (i = 0; i < options.num_host_key_files; i++) { |
| 761 | if (key == sensitive_data.host_keys[i]) |
| 762 | return (i); |
| 763 | } |
| 764 | return (-1); |
| 765 | } |
| 766 | |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 767 | /* |
| 768 | * returns 1 if connection should be dropped, 0 otherwise. |
| 769 | * dropping starts at connection #max_startups_begin with a probability |
| 770 | * of (max_startups_rate/100). the probability increases linearly until |
| 771 | * all connections are dropped for startups > max_startups |
| 772 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 773 | static int |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 774 | drop_connection(int startups) |
| 775 | { |
Darren Tucker | 178fa66 | 2004-11-05 20:09:09 +1100 | [diff] [blame] | 776 | int p, r; |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 777 | |
| 778 | if (startups < options.max_startups_begin) |
| 779 | return 0; |
| 780 | if (startups >= options.max_startups) |
| 781 | return 1; |
| 782 | if (options.max_startups_rate == 100) |
| 783 | return 1; |
| 784 | |
| 785 | p = 100 - options.max_startups_rate; |
| 786 | p *= startups - options.max_startups_begin; |
Darren Tucker | 178fa66 | 2004-11-05 20:09:09 +1100 | [diff] [blame] | 787 | p /= options.max_startups - options.max_startups_begin; |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 788 | p += options.max_startups_rate; |
Darren Tucker | 178fa66 | 2004-11-05 20:09:09 +1100 | [diff] [blame] | 789 | r = arc4random() % 100; |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 790 | |
Darren Tucker | 3269b13 | 2004-11-05 20:20:59 +1100 | [diff] [blame] | 791 | debug("drop_connection: p %d, r %d", p, r); |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 792 | return (r < p) ? 1 : 0; |
| 793 | } |
| 794 | |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 795 | static void |
| 796 | usage(void) |
| 797 | { |
Damien Miller | 0c889cd | 2004-03-22 09:36:00 +1100 | [diff] [blame] | 798 | fprintf(stderr, "%s, %s\n", |
Damien Miller | 2aa6d3c | 2004-09-12 16:53:04 +1000 | [diff] [blame] | 799 | SSH_RELEASE, SSLeay_version(SSLEAY_VERSION)); |
Damien Miller | b408786 | 2004-03-22 09:35:21 +1100 | [diff] [blame] | 800 | fprintf(stderr, |
| 801 | "usage: sshd [-46Ddeiqt] [-b bits] [-f config_file] [-g login_grace_time]\n" |
| 802 | " [-h host_key_file] [-k key_gen_time] [-o option] [-p port] [-u len]\n" |
| 803 | ); |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 804 | exit(1); |
| 805 | } |
| 806 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 807 | static void |
| 808 | send_rexec_state(int fd, Buffer *conf) |
| 809 | { |
| 810 | Buffer m; |
| 811 | |
| 812 | debug3("%s: entering fd = %d config len %d", __func__, fd, |
| 813 | buffer_len(conf)); |
| 814 | |
| 815 | /* |
| 816 | * Protocol from reexec master to child: |
| 817 | * string configuration |
| 818 | * u_int ephemeral_key_follows |
| 819 | * bignum e (only if ephemeral_key_follows == 1) |
| 820 | * bignum n " |
| 821 | * bignum d " |
| 822 | * bignum iqmp " |
| 823 | * bignum p " |
| 824 | * bignum q " |
Darren Tucker | c6f8219 | 2005-09-27 22:46:32 +1000 | [diff] [blame] | 825 | * string rngseed (only if OpenSSL is not self-seeded) |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 826 | */ |
| 827 | buffer_init(&m); |
| 828 | buffer_put_cstring(&m, buffer_ptr(conf)); |
| 829 | |
Darren Tucker | fc95970 | 2004-07-17 16:12:08 +1000 | [diff] [blame] | 830 | if (sensitive_data.server_key != NULL && |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 831 | sensitive_data.server_key->type == KEY_RSA1) { |
| 832 | buffer_put_int(&m, 1); |
| 833 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->e); |
| 834 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->n); |
| 835 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->d); |
| 836 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->iqmp); |
| 837 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->p); |
| 838 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->q); |
| 839 | } else |
| 840 | buffer_put_int(&m, 0); |
| 841 | |
Darren Tucker | c6f8219 | 2005-09-27 22:46:32 +1000 | [diff] [blame] | 842 | #ifndef OPENSSL_PRNG_ONLY |
| 843 | rexec_send_rng_seed(&m); |
| 844 | #endif |
| 845 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 846 | if (ssh_msg_send(fd, 0, &m) == -1) |
| 847 | fatal("%s: ssh_msg_send failed", __func__); |
| 848 | |
| 849 | buffer_free(&m); |
| 850 | |
| 851 | debug3("%s: done", __func__); |
| 852 | } |
| 853 | |
| 854 | static void |
| 855 | recv_rexec_state(int fd, Buffer *conf) |
| 856 | { |
| 857 | Buffer m; |
| 858 | char *cp; |
| 859 | u_int len; |
| 860 | |
| 861 | debug3("%s: entering fd = %d", __func__, fd); |
| 862 | |
| 863 | buffer_init(&m); |
| 864 | |
| 865 | if (ssh_msg_recv(fd, &m) == -1) |
| 866 | fatal("%s: ssh_msg_recv failed", __func__); |
| 867 | if (buffer_get_char(&m) != 0) |
| 868 | fatal("%s: rexec version mismatch", __func__); |
| 869 | |
| 870 | cp = buffer_get_string(&m, &len); |
| 871 | if (conf != NULL) |
| 872 | buffer_append(conf, cp, len + 1); |
| 873 | xfree(cp); |
| 874 | |
| 875 | if (buffer_get_int(&m)) { |
| 876 | if (sensitive_data.server_key != NULL) |
| 877 | key_free(sensitive_data.server_key); |
| 878 | sensitive_data.server_key = key_new_private(KEY_RSA1); |
| 879 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->e); |
| 880 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->n); |
| 881 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->d); |
| 882 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->iqmp); |
| 883 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->p); |
| 884 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->q); |
| 885 | rsa_generate_additional_parameters( |
| 886 | sensitive_data.server_key->rsa); |
| 887 | } |
Darren Tucker | c6f8219 | 2005-09-27 22:46:32 +1000 | [diff] [blame] | 888 | |
| 889 | #ifndef OPENSSL_PRNG_ONLY |
| 890 | rexec_recv_rng_seed(&m); |
| 891 | #endif |
| 892 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 893 | buffer_free(&m); |
| 894 | |
| 895 | debug3("%s: done", __func__); |
| 896 | } |
| 897 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 898 | /* |
| 899 | * Main program for the daemon. |
| 900 | */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 901 | int |
| 902 | main(int ac, char **av) |
| 903 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 904 | extern char *optarg; |
| 905 | extern int optind; |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 906 | int opt, j, i, on = 1; |
Damien Miller | 386c6a2 | 2004-06-30 22:40:20 +1000 | [diff] [blame] | 907 | int sock_in = -1, sock_out = -1, newsock = -1; |
Damien Miller | 166fca8 | 2000-04-20 07:42:21 +1000 | [diff] [blame] | 908 | pid_t pid; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 909 | socklen_t fromlen; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 910 | fd_set *fdset; |
| 911 | struct sockaddr_storage from; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 912 | const char *remote_ip; |
| 913 | int remote_port; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 914 | FILE *f; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 915 | struct addrinfo *ai; |
| 916 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; |
Damien Miller | b999719 | 2003-12-17 16:29:22 +1100 | [diff] [blame] | 917 | char *line; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 918 | int listen_sock, maxfd; |
Darren Tucker | 0f56ed1 | 2004-08-29 16:38:41 +1000 | [diff] [blame] | 919 | int startup_p[2] = { -1 , -1 }, config_s[2] = { -1 , -1 }; |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 920 | int startups = 0; |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame] | 921 | Key *key; |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 922 | Authctxt *authctxt; |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 923 | int ret, key_used = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 924 | |
Kevin Steves | 0ea1d9d | 2002-04-25 18:17:04 +0000 | [diff] [blame] | 925 | #ifdef HAVE_SECUREWARE |
| 926 | (void)set_auth_parameters(ac, av); |
| 927 | #endif |
Damien Miller | 59d3d5b | 2003-08-22 09:34:41 +1000 | [diff] [blame] | 928 | __progname = ssh_get_progname(av[0]); |
Damien Miller | f9b625c | 2000-07-09 22:42:32 +1000 | [diff] [blame] | 929 | init_rng(); |
| 930 | |
Damien Miller | a8ed44b | 2003-01-10 09:53:12 +1100 | [diff] [blame] | 931 | /* Save argv. Duplicate so setproctitle emulation doesn't clobber it */ |
Damien Miller | b8c656e | 2000-06-28 15:22:41 +1000 | [diff] [blame] | 932 | saved_argc = ac; |
Darren Tucker | 17c5d03 | 2004-06-25 14:22:23 +1000 | [diff] [blame] | 933 | rexec_argc = ac; |
Darren Tucker | d8093e4 | 2006-05-04 16:24:34 +1000 | [diff] [blame] | 934 | saved_argv = xcalloc(ac + 1, sizeof(*saved_argv)); |
Damien Miller | a8ed44b | 2003-01-10 09:53:12 +1100 | [diff] [blame] | 935 | for (i = 0; i < ac; i++) |
| 936 | saved_argv[i] = xstrdup(av[i]); |
Damien Miller | 04cb536 | 2003-05-15 21:29:10 +1000 | [diff] [blame] | 937 | saved_argv[i] = NULL; |
Damien Miller | a8ed44b | 2003-01-10 09:53:12 +1100 | [diff] [blame] | 938 | |
| 939 | #ifndef HAVE_SETPROCTITLE |
| 940 | /* Prepare for later setproctitle emulation */ |
| 941 | compat_init_setproctitle(ac, av); |
Damien Miller | f2e3e9d | 2003-06-02 12:15:54 +1000 | [diff] [blame] | 942 | av = saved_argv; |
Damien Miller | a8ed44b | 2003-01-10 09:53:12 +1100 | [diff] [blame] | 943 | #endif |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 944 | |
Damien Miller | bfba354 | 2004-03-22 09:29:57 +1100 | [diff] [blame] | 945 | if (geteuid() == 0 && setgroups(0, NULL) == -1) |
| 946 | debug("setgroups(): %.200s", strerror(errno)); |
| 947 | |
Darren Tucker | ce321d8 | 2005-10-03 18:11:24 +1000 | [diff] [blame] | 948 | /* Ensure that fds 0, 1 and 2 are open or directed to /dev/null */ |
| 949 | sanitise_stdfd(); |
| 950 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 951 | /* Initialize configuration options to their default values. */ |
| 952 | initialize_server_options(&options); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 953 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 954 | /* Parse command-line arguments. */ |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 955 | 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] | 956 | switch (opt) { |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 957 | case '4': |
Darren Tucker | 0f38323 | 2005-01-20 10:57:56 +1100 | [diff] [blame] | 958 | options.address_family = AF_INET; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 959 | break; |
| 960 | case '6': |
Darren Tucker | 0f38323 | 2005-01-20 10:57:56 +1100 | [diff] [blame] | 961 | options.address_family = AF_INET6; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 962 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 963 | case 'f': |
| 964 | config_file_name = optarg; |
| 965 | break; |
| 966 | case 'd': |
Darren Tucker | e98dfa3 | 2003-07-19 19:54:31 +1000 | [diff] [blame] | 967 | if (debug_flag == 0) { |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 968 | debug_flag = 1; |
| 969 | options.log_level = SYSLOG_LEVEL_DEBUG1; |
Darren Tucker | e98dfa3 | 2003-07-19 19:54:31 +1000 | [diff] [blame] | 970 | } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 971 | options.log_level++; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 972 | break; |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 973 | case 'D': |
| 974 | no_daemon_flag = 1; |
| 975 | break; |
Ben Lindstrom | 9fce9f0 | 2001-04-11 23:10:09 +0000 | [diff] [blame] | 976 | case 'e': |
| 977 | log_stderr = 1; |
| 978 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 979 | case 'i': |
| 980 | inetd_flag = 1; |
| 981 | break; |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 982 | case 'r': |
| 983 | rexec_flag = 0; |
| 984 | break; |
| 985 | case 'R': |
| 986 | rexeced_flag = 1; |
| 987 | inetd_flag = 1; |
| 988 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 989 | case 'Q': |
Ben Lindstrom | d539020 | 2001-01-29 08:07:43 +0000 | [diff] [blame] | 990 | /* ignored */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 991 | break; |
| 992 | case 'q': |
| 993 | options.log_level = SYSLOG_LEVEL_QUIET; |
| 994 | break; |
| 995 | case 'b': |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 996 | options.server_key_bits = (int)strtonum(optarg, 256, |
| 997 | 32768, NULL); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 998 | break; |
| 999 | case 'p': |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1000 | options.ports_from_cmdline = 1; |
Damien Miller | e4340be | 2000-09-16 13:29:08 +1100 | [diff] [blame] | 1001 | if (options.num_ports >= MAX_PORTS) { |
| 1002 | fprintf(stderr, "too many ports.\n"); |
| 1003 | exit(1); |
| 1004 | } |
Ben Lindstrom | 19066a1 | 2001-04-12 23:39:26 +0000 | [diff] [blame] | 1005 | options.ports[options.num_ports++] = a2port(optarg); |
| 1006 | if (options.ports[options.num_ports-1] == 0) { |
| 1007 | fprintf(stderr, "Bad port number.\n"); |
| 1008 | exit(1); |
| 1009 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1010 | break; |
| 1011 | case 'g': |
Ben Lindstrom | 1bda4c8 | 2001-06-05 19:59:08 +0000 | [diff] [blame] | 1012 | if ((options.login_grace_time = convtime(optarg)) == -1) { |
| 1013 | fprintf(stderr, "Invalid login grace time.\n"); |
| 1014 | exit(1); |
| 1015 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1016 | break; |
| 1017 | case 'k': |
Ben Lindstrom | 1bda4c8 | 2001-06-05 19:59:08 +0000 | [diff] [blame] | 1018 | if ((options.key_regeneration_time = convtime(optarg)) == -1) { |
| 1019 | fprintf(stderr, "Invalid key regeneration interval.\n"); |
| 1020 | exit(1); |
| 1021 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1022 | break; |
| 1023 | case 'h': |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1024 | if (options.num_host_key_files >= MAX_HOSTKEYS) { |
| 1025 | fprintf(stderr, "too many host keys.\n"); |
| 1026 | exit(1); |
| 1027 | } |
| 1028 | options.host_key_files[options.num_host_key_files++] = optarg; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1029 | break; |
Ben Lindstrom | 794325a | 2001-08-06 21:09:07 +0000 | [diff] [blame] | 1030 | case 't': |
| 1031 | test_flag = 1; |
| 1032 | break; |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 1033 | case 'u': |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1034 | utmp_len = (u_int)strtonum(optarg, 0, MAXHOSTNAMELEN+1, NULL); |
Ben Lindstrom | 41daec7 | 2002-07-23 21:15:13 +0000 | [diff] [blame] | 1035 | if (utmp_len > MAXHOSTNAMELEN) { |
| 1036 | fprintf(stderr, "Invalid utmp length.\n"); |
| 1037 | exit(1); |
| 1038 | } |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 1039 | break; |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 1040 | case 'o': |
Damien Miller | b999719 | 2003-12-17 16:29:22 +1100 | [diff] [blame] | 1041 | line = xstrdup(optarg); |
| 1042 | if (process_server_config_line(&options, line, |
Darren Tucker | 4515047 | 2006-07-12 22:34:17 +1000 | [diff] [blame] | 1043 | "command-line", 0, NULL, NULL, NULL, NULL) != 0) |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1044 | exit(1); |
Damien Miller | b999719 | 2003-12-17 16:29:22 +1100 | [diff] [blame] | 1045 | xfree(line); |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 1046 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1047 | case '?': |
| 1048 | default: |
Ben Lindstrom | ade03f6 | 2001-12-06 18:22:17 +0000 | [diff] [blame] | 1049 | usage(); |
| 1050 | break; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1051 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1052 | } |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1053 | if (rexeced_flag || inetd_flag) |
| 1054 | rexec_flag = 0; |
| 1055 | if (rexec_flag && (av[0] == NULL || *av[0] != '/')) |
| 1056 | fatal("sshd re-exec requires execution with an absolute path"); |
| 1057 | if (rexeced_flag) |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1058 | closefrom(REEXEC_MIN_FREE_FD); |
| 1059 | else |
| 1060 | closefrom(REEXEC_DEVCRYPTO_RESERVED_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1061 | |
Ben Lindstrom | 425fb02 | 2001-03-29 00:31:20 +0000 | [diff] [blame] | 1062 | SSLeay_add_all_algorithms(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1063 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1064 | /* |
| 1065 | * Force logging to stderr until we have loaded the private host |
| 1066 | * key (unless started from inetd) |
| 1067 | */ |
Kevin Steves | ec84dc1 | 2000-12-13 17:45:15 +0000 | [diff] [blame] | 1068 | log_init(__progname, |
Damien Miller | 5aa5d78 | 2002-02-08 22:01:54 +1100 | [diff] [blame] | 1069 | options.log_level == SYSLOG_LEVEL_NOT_SET ? |
| 1070 | SYSLOG_LEVEL_INFO : options.log_level, |
| 1071 | options.log_facility == SYSLOG_FACILITY_NOT_SET ? |
| 1072 | SYSLOG_FACILITY_AUTH : options.log_facility, |
Ben Lindstrom | c2faa4a | 2002-11-09 15:50:03 +0000 | [diff] [blame] | 1073 | log_stderr || !inetd_flag); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1074 | |
Darren Tucker | 86c093d | 2004-03-08 22:59:03 +1100 | [diff] [blame] | 1075 | /* |
| 1076 | * Unset KRB5CCNAME, otherwise the user's session may inherit it from |
| 1077 | * root's environment |
Damien Miller | 94cf4c8 | 2005-07-17 17:04:47 +1000 | [diff] [blame] | 1078 | */ |
Darren Tucker | 9dc6c7d | 2005-02-02 18:30:33 +1100 | [diff] [blame] | 1079 | if (getenv("KRB5CCNAME") != NULL) |
| 1080 | unsetenv("KRB5CCNAME"); |
| 1081 | |
Tim Rice | 81ed518 | 2002-09-25 17:38:46 -0700 | [diff] [blame] | 1082 | #ifdef _UNICOS |
Darren Tucker | 1298496 | 2004-05-24 13:37:13 +1000 | [diff] [blame] | 1083 | /* Cray can define user privs drop all privs now! |
Ben Lindstrom | 6db66ff | 2001-08-06 23:29:16 +0000 | [diff] [blame] | 1084 | * Not needed on PRIV_SU systems! |
| 1085 | */ |
| 1086 | drop_cray_privs(); |
| 1087 | #endif |
| 1088 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1089 | sensitive_data.server_key = NULL; |
| 1090 | sensitive_data.ssh1_host_key = NULL; |
| 1091 | sensitive_data.have_ssh1_key = 0; |
| 1092 | sensitive_data.have_ssh2_key = 0; |
| 1093 | |
| 1094 | /* Fetch our configuration */ |
| 1095 | buffer_init(&cfg); |
| 1096 | if (rexeced_flag) |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1097 | recv_rexec_state(REEXEC_CONFIG_PASS_FD, &cfg); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1098 | else |
| 1099 | load_server_config(config_file_name, &cfg); |
| 1100 | |
Darren Tucker | 4515047 | 2006-07-12 22:34:17 +1000 | [diff] [blame] | 1101 | parse_server_config(&options, rexeced_flag ? "rexec" : config_file_name, |
| 1102 | &cfg, NULL, NULL, NULL); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1103 | |
Darren Tucker | c6f8219 | 2005-09-27 22:46:32 +1000 | [diff] [blame] | 1104 | seed_rng(); |
| 1105 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1106 | /* Fill in default values for those options not explicitly set. */ |
| 1107 | fill_default_server_options(&options); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1108 | |
Darren Tucker | 0f38323 | 2005-01-20 10:57:56 +1100 | [diff] [blame] | 1109 | /* set default channel AF */ |
| 1110 | channel_set_af(options.address_family); |
| 1111 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1112 | /* Check that there are no remaining arguments. */ |
| 1113 | if (optind < ac) { |
| 1114 | fprintf(stderr, "Extra argument %s.\n", av[optind]); |
| 1115 | exit(1); |
| 1116 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1117 | |
Damien Miller | 2aa6d3c | 2004-09-12 16:53:04 +1000 | [diff] [blame] | 1118 | debug("sshd version %.100s", SSH_RELEASE); |
Damien Miller | 2ccf661 | 1999-11-15 15:25:10 +1100 | [diff] [blame] | 1119 | |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1120 | /* load private host keys */ |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1121 | sensitive_data.host_keys = xcalloc(options.num_host_key_files, |
Ben Lindstrom | a962c2f | 2002-07-04 00:14:17 +0000 | [diff] [blame] | 1122 | sizeof(Key *)); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1123 | for (i = 0; i < options.num_host_key_files; i++) |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1124 | sensitive_data.host_keys[i] = NULL; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1125 | |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1126 | for (i = 0; i < options.num_host_key_files; i++) { |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame] | 1127 | key = key_load_private(options.host_key_files[i], "", NULL); |
| 1128 | sensitive_data.host_keys[i] = key; |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1129 | if (key == NULL) { |
Ben Lindstrom | 15f3386 | 2001-04-16 02:00:02 +0000 | [diff] [blame] | 1130 | error("Could not load host key: %s", |
| 1131 | options.host_key_files[i]); |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame] | 1132 | sensitive_data.host_keys[i] = NULL; |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1133 | continue; |
| 1134 | } |
Ben Lindstrom | 1c37c6a | 2001-12-06 18:00:18 +0000 | [diff] [blame] | 1135 | switch (key->type) { |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1136 | case KEY_RSA1: |
| 1137 | sensitive_data.ssh1_host_key = key; |
| 1138 | sensitive_data.have_ssh1_key = 1; |
| 1139 | break; |
| 1140 | case KEY_RSA: |
| 1141 | case KEY_DSA: |
| 1142 | sensitive_data.have_ssh2_key = 1; |
| 1143 | break; |
| 1144 | } |
Ben Lindstrom | d0fca42 | 2001-03-26 13:44:06 +0000 | [diff] [blame] | 1145 | debug("private host key: #%d type %d %s", i, key->type, |
| 1146 | key_type(key)); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1147 | } |
| 1148 | if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 1149 | logit("Disabling protocol version 1. Could not load host key"); |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1150 | options.protocol &= ~SSH_PROTO_1; |
| 1151 | } |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1152 | if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 1153 | logit("Disabling protocol version 2. Could not load host key"); |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1154 | options.protocol &= ~SSH_PROTO_2; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1155 | } |
Kevin Steves | adf74cd | 2001-02-05 14:22:50 +0000 | [diff] [blame] | 1156 | if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 1157 | logit("sshd: no hostkeys available -- exiting."); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1158 | exit(1); |
| 1159 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1160 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1161 | /* Check certain values for sanity. */ |
| 1162 | if (options.protocol & SSH_PROTO_1) { |
| 1163 | if (options.server_key_bits < 512 || |
| 1164 | options.server_key_bits > 32768) { |
| 1165 | fprintf(stderr, "Bad server key size.\n"); |
| 1166 | exit(1); |
| 1167 | } |
| 1168 | /* |
| 1169 | * Check that server and host key lengths differ sufficiently. This |
| 1170 | * is necessary to make double encryption work with rsaref. Oh, I |
| 1171 | * hate software patents. I dont know if this can go? Niels |
| 1172 | */ |
| 1173 | if (options.server_key_bits > |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 1174 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) - |
| 1175 | SSH_KEY_BITS_RESERVED && options.server_key_bits < |
| 1176 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + |
| 1177 | SSH_KEY_BITS_RESERVED) { |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1178 | options.server_key_bits = |
Ben Lindstrom | 822b634 | 2002-06-23 21:38:49 +0000 | [diff] [blame] | 1179 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + |
| 1180 | SSH_KEY_BITS_RESERVED; |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1181 | debug("Forcing server key to %d bits to make it differ from host key.", |
| 1182 | options.server_key_bits); |
| 1183 | } |
| 1184 | } |
| 1185 | |
Ben Lindstrom | a26ea63 | 2002-06-06 20:46:25 +0000 | [diff] [blame] | 1186 | if (use_privsep) { |
Ben Lindstrom | a26ea63 | 2002-06-06 20:46:25 +0000 | [diff] [blame] | 1187 | struct stat st; |
| 1188 | |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1189 | if (getpwnam(SSH_PRIVSEP_USER) == NULL) |
Ben Lindstrom | a26ea63 | 2002-06-06 20:46:25 +0000 | [diff] [blame] | 1190 | fatal("Privilege separation user %s does not exist", |
| 1191 | SSH_PRIVSEP_USER); |
| 1192 | if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) || |
| 1193 | (S_ISDIR(st.st_mode) == 0)) |
| 1194 | fatal("Missing privilege separation directory: %s", |
| 1195 | _PATH_PRIVSEP_CHROOT_DIR); |
Ben Lindstrom | 5962735 | 2002-06-27 18:02:21 +0000 | [diff] [blame] | 1196 | |
| 1197 | #ifdef HAVE_CYGWIN |
| 1198 | if (check_ntsec(_PATH_PRIVSEP_CHROOT_DIR) && |
| 1199 | (st.st_uid != getuid () || |
| 1200 | (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)) |
| 1201 | #else |
Ben Lindstrom | 2dfacb3 | 2002-06-23 00:33:47 +0000 | [diff] [blame] | 1202 | 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] | 1203 | #endif |
Damien Miller | 180fc5b | 2003-02-24 11:50:18 +1100 | [diff] [blame] | 1204 | fatal("%s must be owned by root and not group or " |
| 1205 | "world-writable.", _PATH_PRIVSEP_CHROOT_DIR); |
Ben Lindstrom | a26ea63 | 2002-06-06 20:46:25 +0000 | [diff] [blame] | 1206 | } |
| 1207 | |
Ben Lindstrom | 794325a | 2001-08-06 21:09:07 +0000 | [diff] [blame] | 1208 | /* Configuration looks good, so exit if in test mode. */ |
| 1209 | if (test_flag) |
| 1210 | exit(0); |
| 1211 | |
Damien Miller | 87aea25 | 2002-05-10 12:20:24 +1000 | [diff] [blame] | 1212 | /* |
| 1213 | * Clear out any supplemental groups we may have inherited. This |
| 1214 | * prevents inadvertent creation of files with bad modes (in the |
Damien Miller | a8e06ce | 2003-11-21 23:48:55 +1100 | [diff] [blame] | 1215 | * portable version at least, it's certainly possible for PAM |
| 1216 | * 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] | 1217 | * module which might be used). |
| 1218 | */ |
| 1219 | if (setgroups(0, NULL) < 0) |
| 1220 | debug("setgroups() failed: %.200s", strerror(errno)); |
| 1221 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1222 | if (rexec_flag) { |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1223 | rexec_argv = xcalloc(rexec_argc + 2, sizeof(char *)); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1224 | for (i = 0; i < rexec_argc; i++) { |
| 1225 | debug("rexec_argv[%d]='%s'", i, saved_argv[i]); |
| 1226 | rexec_argv[i] = saved_argv[i]; |
| 1227 | } |
| 1228 | rexec_argv[rexec_argc] = "-R"; |
| 1229 | rexec_argv[rexec_argc + 1] = NULL; |
| 1230 | } |
| 1231 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1232 | /* Initialize the log (it is reinitialized below in case we forked). */ |
Darren Tucker | ea7c812 | 2005-01-20 11:03:08 +1100 | [diff] [blame] | 1233 | if (debug_flag && (!inetd_flag || rexeced_flag)) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1234 | log_stderr = 1; |
Kevin Steves | ec84dc1 | 2000-12-13 17:45:15 +0000 | [diff] [blame] | 1235 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1236 | |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1237 | /* |
| 1238 | * If not in debugging mode, and not started from inetd, disconnect |
| 1239 | * from the controlling terminal, and fork. The original process |
| 1240 | * exits. |
| 1241 | */ |
Ben Lindstrom | c72745a | 2000-12-02 19:03:54 +0000 | [diff] [blame] | 1242 | if (!(debug_flag || inetd_flag || no_daemon_flag)) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1243 | #ifdef TIOCNOTTY |
| 1244 | int fd; |
| 1245 | #endif /* TIOCNOTTY */ |
| 1246 | if (daemon(0, 0) < 0) |
| 1247 | fatal("daemon() failed: %.200s", strerror(errno)); |
| 1248 | |
| 1249 | /* Disconnect from the controlling tty. */ |
| 1250 | #ifdef TIOCNOTTY |
Ben Lindstrom | 31ca54a | 2001-02-09 02:11:24 +0000 | [diff] [blame] | 1251 | fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1252 | if (fd >= 0) { |
| 1253 | (void) ioctl(fd, TIOCNOTTY, NULL); |
| 1254 | close(fd); |
| 1255 | } |
| 1256 | #endif /* TIOCNOTTY */ |
| 1257 | } |
| 1258 | /* Reinitialize the log (because of the fork above). */ |
Kevin Steves | ec84dc1 | 2000-12-13 17:45:15 +0000 | [diff] [blame] | 1259 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1260 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1261 | /* Initialize the random number generator. */ |
| 1262 | arc4random_stir(); |
| 1263 | |
| 1264 | /* Chdir to the root directory so that the current disk can be |
| 1265 | unmounted if desired. */ |
| 1266 | chdir("/"); |
Damien Miller | 9f0f5c6 | 2001-12-21 14:45:46 +1100 | [diff] [blame] | 1267 | |
Ben Lindstrom | de71cda | 2001-03-24 00:43:26 +0000 | [diff] [blame] | 1268 | /* ignore SIGPIPE */ |
| 1269 | signal(SIGPIPE, SIG_IGN); |
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 | /* Start listening for a socket, unless started from inetd. */ |
| 1272 | if (inetd_flag) { |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1273 | int fd; |
| 1274 | |
Damien Miller | 994cf14 | 2000-07-21 10:19:44 +1000 | [diff] [blame] | 1275 | startup_pipe = -1; |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1276 | if (rexeced_flag) { |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1277 | close(REEXEC_CONFIG_PASS_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1278 | sock_in = sock_out = dup(STDIN_FILENO); |
| 1279 | if (!debug_flag) { |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1280 | startup_pipe = dup(REEXEC_STARTUP_PIPE_FD); |
| 1281 | close(REEXEC_STARTUP_PIPE_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1282 | } |
| 1283 | } else { |
| 1284 | sock_in = dup(STDIN_FILENO); |
| 1285 | sock_out = dup(STDOUT_FILENO); |
| 1286 | } |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1287 | /* |
| 1288 | * We intentionally do not close the descriptors 0, 1, and 2 |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1289 | * as our code for setting the descriptors won't work if |
Damien Miller | eba71ba | 2000-04-29 23:57:08 +1000 | [diff] [blame] | 1290 | * ttyfd happens to be one of those. |
| 1291 | */ |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1292 | if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { |
| 1293 | dup2(fd, STDIN_FILENO); |
| 1294 | dup2(fd, STDOUT_FILENO); |
| 1295 | if (fd > STDOUT_FILENO) |
| 1296 | close(fd); |
| 1297 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1298 | debug("inetd sockets after dupping: %d, %d", sock_in, sock_out); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1299 | if ((options.protocol & SSH_PROTO_1) && |
| 1300 | sensitive_data.server_key == NULL) |
Ben Lindstrom | ca42d5f | 2001-03-09 18:25:32 +0000 | [diff] [blame] | 1301 | generate_ephemeral_server_key(); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1302 | } else { |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1303 | for (ai = options.listen_addrs; ai; ai = ai->ai_next) { |
| 1304 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) |
| 1305 | continue; |
| 1306 | if (num_listen_socks >= MAX_LISTEN_SOCKS) |
| 1307 | fatal("Too many listen sockets. " |
| 1308 | "Enlarge MAX_LISTEN_SOCKS"); |
Darren Tucker | 96d4710 | 2005-02-09 09:53:48 +1100 | [diff] [blame] | 1309 | if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen, |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1310 | ntop, sizeof(ntop), strport, sizeof(strport), |
Darren Tucker | 96d4710 | 2005-02-09 09:53:48 +1100 | [diff] [blame] | 1311 | NI_NUMERICHOST|NI_NUMERICSERV)) != 0) { |
| 1312 | error("getnameinfo failed: %.100s", |
| 1313 | (ret != EAI_SYSTEM) ? gai_strerror(ret) : |
| 1314 | strerror(errno)); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1315 | continue; |
| 1316 | } |
| 1317 | /* Create socket for listening. */ |
Damien Miller | 2372ace | 2003-05-14 13:42:23 +1000 | [diff] [blame] | 1318 | listen_sock = socket(ai->ai_family, ai->ai_socktype, |
| 1319 | ai->ai_protocol); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1320 | if (listen_sock < 0) { |
| 1321 | /* kernel may not support ipv6 */ |
| 1322 | verbose("socket: %.100s", strerror(errno)); |
| 1323 | continue; |
| 1324 | } |
Damien Miller | 232711f | 2004-06-15 10:35:30 +1000 | [diff] [blame] | 1325 | if (set_nonblock(listen_sock) == -1) { |
Darren Tucker | efa3706 | 2004-02-24 09:20:29 +1100 | [diff] [blame] | 1326 | close(listen_sock); |
| 1327 | continue; |
| 1328 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1329 | /* |
Damien Miller | e1383ce | 2002-09-19 11:49:37 +1000 | [diff] [blame] | 1330 | * Set socket options. |
| 1331 | * Allow local port reuse in TIME_WAIT. |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1332 | */ |
Damien Miller | e1383ce | 2002-09-19 11:49:37 +1000 | [diff] [blame] | 1333 | if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, |
| 1334 | &on, sizeof(on)) == -1) |
| 1335 | error("setsockopt SO_REUSEADDR: %s", strerror(errno)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1336 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1337 | debug("Bind to port %s on %s.", strport, ntop); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1338 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1339 | /* Bind the socket to the desired port. */ |
Damien Miller | 0a4e27d | 2001-02-18 12:36:39 +1100 | [diff] [blame] | 1340 | if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) { |
| 1341 | if (!ai->ai_next) |
| 1342 | error("Bind to port %s on %s failed: %.200s.", |
| 1343 | strport, ntop, strerror(errno)); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1344 | close(listen_sock); |
| 1345 | continue; |
| 1346 | } |
| 1347 | listen_socks[num_listen_socks] = listen_sock; |
| 1348 | num_listen_socks++; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1349 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1350 | /* Start listening on the port. */ |
Darren Tucker | 3175eb9 | 2003-12-09 19:15:11 +1100 | [diff] [blame] | 1351 | if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0) |
Damien Miller | b24c2f8 | 2006-03-15 12:04:36 +1100 | [diff] [blame] | 1352 | fatal("listen on [%s]:%s: %.100s", |
| 1353 | ntop, strport, strerror(errno)); |
| 1354 | logit("Server listening on %s port %s.", ntop, strport); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1355 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1356 | freeaddrinfo(options.listen_addrs); |
| 1357 | |
| 1358 | if (!num_listen_socks) |
| 1359 | fatal("Cannot bind any address."); |
| 1360 | |
Ben Lindstrom | 9809786 | 2001-06-25 05:10:20 +0000 | [diff] [blame] | 1361 | if (options.protocol & SSH_PROTO_1) |
| 1362 | generate_ephemeral_server_key(); |
| 1363 | |
| 1364 | /* |
| 1365 | * Arrange to restart on SIGHUP. The handler needs |
| 1366 | * listen_sock. |
| 1367 | */ |
| 1368 | signal(SIGHUP, sighup_handler); |
| 1369 | |
| 1370 | signal(SIGTERM, sigterm_handler); |
| 1371 | signal(SIGQUIT, sigterm_handler); |
| 1372 | |
| 1373 | /* Arrange SIGCHLD to be caught. */ |
| 1374 | signal(SIGCHLD, main_sigchld_handler); |
| 1375 | |
| 1376 | /* Write out the pid file after the sigterm handler is setup */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1377 | if (!debug_flag) { |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1378 | /* |
Ben Lindstrom | 7ad9710 | 2000-12-06 01:42:49 +0000 | [diff] [blame] | 1379 | * Record our pid in /var/run/sshd.pid to make it |
| 1380 | * easier to kill the correct sshd. We don't want to |
| 1381 | * do this before the bind above because the bind will |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1382 | * fail if there already is a daemon, and this will |
| 1383 | * overwrite any old pid in the file. |
| 1384 | */ |
Damien Miller | bac2d8a | 2000-09-05 16:13:06 +1100 | [diff] [blame] | 1385 | f = fopen(options.pid_file, "wb"); |
Darren Tucker | e532704 | 2003-07-03 13:40:44 +1000 | [diff] [blame] | 1386 | if (f == NULL) { |
| 1387 | error("Couldn't create pid file \"%s\": %s", |
| 1388 | options.pid_file, strerror(errno)); |
| 1389 | } else { |
Ben Lindstrom | ce0f634 | 2002-06-11 16:42:49 +0000 | [diff] [blame] | 1390 | fprintf(f, "%ld\n", (long) getpid()); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1391 | fclose(f); |
| 1392 | } |
| 1393 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1394 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1395 | /* setup fd set for listen */ |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1396 | fdset = NULL; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1397 | maxfd = 0; |
| 1398 | for (i = 0; i < num_listen_socks; i++) |
| 1399 | if (listen_socks[i] > maxfd) |
| 1400 | maxfd = listen_socks[i]; |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1401 | /* pipes connected to unauthenticated childs */ |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1402 | startup_pipes = xcalloc(options.max_startups, sizeof(int)); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1403 | for (i = 0; i < options.max_startups; i++) |
| 1404 | startup_pipes[i] = -1; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1405 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1406 | /* |
| 1407 | * Stay listening for connections until the system crashes or |
| 1408 | * the daemon is killed with a signal. |
| 1409 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1410 | for (;;) { |
| 1411 | if (received_sighup) |
| 1412 | sighup_restart(); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1413 | if (fdset != NULL) |
| 1414 | xfree(fdset); |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1415 | fdset = (fd_set *)xcalloc(howmany(maxfd + 1, NFDBITS), |
| 1416 | sizeof(fd_mask)); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1417 | |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1418 | for (i = 0; i < num_listen_socks; i++) |
| 1419 | FD_SET(listen_socks[i], fdset); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1420 | for (i = 0; i < options.max_startups; i++) |
| 1421 | if (startup_pipes[i] != -1) |
| 1422 | FD_SET(startup_pipes[i], fdset); |
| 1423 | |
| 1424 | /* Wait in select until there is a connection. */ |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 1425 | ret = select(maxfd+1, fdset, NULL, NULL, NULL); |
| 1426 | if (ret < 0 && errno != EINTR) |
| 1427 | error("select: %.100s", strerror(errno)); |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 1428 | if (received_sigterm) { |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 1429 | logit("Received signal %d; terminating.", |
Ben Lindstrom | f8f065b | 2001-12-06 17:52:16 +0000 | [diff] [blame] | 1430 | (int) received_sigterm); |
Ben Lindstrom | ec46e0b | 2001-06-09 01:27:31 +0000 | [diff] [blame] | 1431 | close_listen_socks(); |
| 1432 | unlink(options.pid_file); |
| 1433 | exit(255); |
| 1434 | } |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 1435 | if (key_used && key_do_regen) { |
Ben Lindstrom | ca42d5f | 2001-03-09 18:25:32 +0000 | [diff] [blame] | 1436 | generate_ephemeral_server_key(); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 1437 | key_used = 0; |
| 1438 | key_do_regen = 0; |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1439 | } |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 1440 | if (ret < 0) |
| 1441 | continue; |
| 1442 | |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1443 | for (i = 0; i < options.max_startups; i++) |
| 1444 | if (startup_pipes[i] != -1 && |
| 1445 | FD_ISSET(startup_pipes[i], fdset)) { |
| 1446 | /* |
| 1447 | * the read end of the pipe is ready |
| 1448 | * if the child has closed the pipe |
Ben Lindstrom | 4dccfa5 | 2000-12-28 16:40:05 +0000 | [diff] [blame] | 1449 | * after successful authentication |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1450 | * or if the child has died |
| 1451 | */ |
| 1452 | close(startup_pipes[i]); |
| 1453 | startup_pipes[i] = -1; |
| 1454 | startups--; |
| 1455 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1456 | for (i = 0; i < num_listen_socks; i++) { |
| 1457 | if (!FD_ISSET(listen_socks[i], fdset)) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1458 | continue; |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1459 | fromlen = sizeof(from); |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1460 | newsock = accept(listen_socks[i], |
| 1461 | (struct sockaddr *)&from, &fromlen); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1462 | if (newsock < 0) { |
| 1463 | if (errno != EINTR && errno != EWOULDBLOCK) |
| 1464 | error("accept: %.100s", strerror(errno)); |
| 1465 | continue; |
| 1466 | } |
Damien Miller | 232711f | 2004-06-15 10:35:30 +1000 | [diff] [blame] | 1467 | if (unset_nonblock(newsock) == -1) { |
Darren Tucker | efa3706 | 2004-02-24 09:20:29 +1100 | [diff] [blame] | 1468 | close(newsock); |
| 1469 | continue; |
| 1470 | } |
Damien Miller | 942da03 | 2000-08-18 13:59:06 +1000 | [diff] [blame] | 1471 | if (drop_connection(startups) == 1) { |
| 1472 | debug("drop connection #%d", startups); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1473 | close(newsock); |
| 1474 | continue; |
| 1475 | } |
| 1476 | if (pipe(startup_p) == -1) { |
| 1477 | close(newsock); |
| 1478 | continue; |
| 1479 | } |
| 1480 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1481 | if (rexec_flag && socketpair(AF_UNIX, |
| 1482 | SOCK_STREAM, 0, config_s) == -1) { |
| 1483 | error("reexec socketpair: %s", |
| 1484 | strerror(errno)); |
| 1485 | close(newsock); |
| 1486 | close(startup_p[0]); |
| 1487 | close(startup_p[1]); |
| 1488 | continue; |
| 1489 | } |
| 1490 | |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1491 | for (j = 0; j < options.max_startups; j++) |
| 1492 | if (startup_pipes[j] == -1) { |
| 1493 | startup_pipes[j] = startup_p[0]; |
| 1494 | if (maxfd < startup_p[0]) |
| 1495 | maxfd = startup_p[0]; |
| 1496 | startups++; |
| 1497 | break; |
| 1498 | } |
Kevin Steves | ef4eea9 | 2001-02-05 12:42:17 +0000 | [diff] [blame] | 1499 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1500 | /* |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1501 | * Got connection. Fork a child to handle it, unless |
| 1502 | * we are in debugging mode. |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1503 | */ |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1504 | if (debug_flag) { |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1505 | /* |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1506 | * In debugging mode. Close the listening |
| 1507 | * socket, and start processing the |
| 1508 | * connection without forking. |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1509 | */ |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1510 | debug("Server will not fork when running in debugging mode."); |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1511 | close_listen_socks(); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1512 | sock_in = newsock; |
| 1513 | sock_out = newsock; |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1514 | close(startup_p[0]); |
| 1515 | close(startup_p[1]); |
Damien Miller | 4d97ba2 | 2000-07-11 18:15:50 +1000 | [diff] [blame] | 1516 | startup_pipe = -1; |
Damien Miller | 182ee6e | 2000-07-12 09:45:27 +1000 | [diff] [blame] | 1517 | pid = getpid(); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1518 | if (rexec_flag) { |
| 1519 | send_rexec_state(config_s[0], |
| 1520 | &cfg); |
| 1521 | close(config_s[0]); |
| 1522 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1523 | break; |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1524 | } else { |
| 1525 | /* |
| 1526 | * Normal production daemon. Fork, and have |
| 1527 | * the child process the connection. The |
| 1528 | * parent continues listening. |
| 1529 | */ |
| 1530 | if ((pid = fork()) == 0) { |
| 1531 | /* |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1532 | * Child. Close the listening and |
| 1533 | * max_startup sockets. Start using |
| 1534 | * the accepted socket. Reinitialize |
| 1535 | * logging (since our pid has changed). |
| 1536 | * We break out of the loop to handle |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1537 | * the connection. |
| 1538 | */ |
| 1539 | startup_pipe = startup_p[1]; |
Ben Lindstrom | d84df98 | 2001-12-06 16:35:40 +0000 | [diff] [blame] | 1540 | close_startup_pipes(); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1541 | close_listen_socks(); |
| 1542 | sock_in = newsock; |
| 1543 | sock_out = newsock; |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1544 | log_init(__progname, |
| 1545 | options.log_level, |
| 1546 | options.log_facility, |
| 1547 | log_stderr); |
Darren Tucker | 0f56ed1 | 2004-08-29 16:38:41 +1000 | [diff] [blame] | 1548 | if (rexec_flag) |
| 1549 | close(config_s[0]); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1550 | break; |
| 1551 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1552 | } |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1553 | |
| 1554 | /* Parent. Stay in the loop. */ |
| 1555 | if (pid < 0) |
| 1556 | error("fork: %.100s", strerror(errno)); |
| 1557 | else |
Ben Lindstrom | ce0f634 | 2002-06-11 16:42:49 +0000 | [diff] [blame] | 1558 | debug("Forked child %ld.", (long)pid); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1559 | |
| 1560 | close(startup_p[1]); |
| 1561 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1562 | if (rexec_flag) { |
| 1563 | send_rexec_state(config_s[0], &cfg); |
| 1564 | close(config_s[0]); |
| 1565 | close(config_s[1]); |
| 1566 | } |
| 1567 | |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1568 | /* |
| 1569 | * Mark that the key has been used (it |
| 1570 | * was "given" to the child). |
| 1571 | */ |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 1572 | if ((options.protocol & SSH_PROTO_1) && |
| 1573 | key_used == 0) { |
| 1574 | /* Schedule server key regeneration alarm. */ |
Ben Lindstrom | 5ade9ab | 2003-08-25 01:16:21 +0000 | [diff] [blame] | 1575 | signal(SIGALRM, key_regeneration_alarm); |
Ben Lindstrom | db65e8f | 2001-01-19 04:26:52 +0000 | [diff] [blame] | 1576 | alarm(options.key_regeneration_time); |
| 1577 | key_used = 1; |
| 1578 | } |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1579 | |
| 1580 | arc4random_stir(); |
Damien Miller | 3702396 | 2000-07-11 17:31:38 +1000 | [diff] [blame] | 1581 | close(newsock); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1582 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1583 | /* child process check (or debug mode) */ |
| 1584 | if (num_listen_socks < 0) |
| 1585 | break; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1586 | } |
| 1587 | } |
| 1588 | |
| 1589 | /* This is the child processing a new connection. */ |
Damien Miller | 57aae98 | 2004-03-08 23:11:25 +1100 | [diff] [blame] | 1590 | setproctitle("%s", "[accepted]"); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1591 | |
Darren Tucker | 6832b83 | 2004-08-12 22:36:51 +1000 | [diff] [blame] | 1592 | /* |
| 1593 | * Create a new session and process group since the 4.4BSD |
| 1594 | * setlogin() affects the entire process group. We don't |
| 1595 | * want the child to be able to affect the parent. |
| 1596 | */ |
| 1597 | #if !defined(SSHD_ACQUIRES_CTTY) |
| 1598 | /* |
| 1599 | * If setsid is called, on some platforms sshd will later acquire a |
| 1600 | * controlling terminal which will result in "could not set |
| 1601 | * controlling tty" errors. |
| 1602 | */ |
| 1603 | if (!debug_flag && !inetd_flag && setsid() < 0) |
| 1604 | error("setsid: %.100s", strerror(errno)); |
| 1605 | #endif |
| 1606 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1607 | if (rexec_flag) { |
| 1608 | int fd; |
| 1609 | |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1610 | debug("rexec start in %d out %d newsock %d pipe %d sock %d", |
| 1611 | sock_in, sock_out, newsock, startup_pipe, config_s[0]); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1612 | dup2(newsock, STDIN_FILENO); |
| 1613 | dup2(STDIN_FILENO, STDOUT_FILENO); |
| 1614 | if (startup_pipe == -1) |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1615 | close(REEXEC_STARTUP_PIPE_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1616 | else |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1617 | dup2(startup_pipe, REEXEC_STARTUP_PIPE_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1618 | |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1619 | dup2(config_s[1], REEXEC_CONFIG_PASS_FD); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1620 | close(config_s[1]); |
Darren Tucker | d883593 | 2004-08-12 22:42:29 +1000 | [diff] [blame] | 1621 | if (startup_pipe != -1) |
| 1622 | close(startup_pipe); |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1623 | |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1624 | execv(rexec_argv[0], rexec_argv); |
| 1625 | |
| 1626 | /* Reexec has failed, fall back and continue */ |
| 1627 | error("rexec of %s failed: %s", rexec_argv[0], strerror(errno)); |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1628 | recv_rexec_state(REEXEC_CONFIG_PASS_FD, NULL); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1629 | log_init(__progname, options.log_level, |
| 1630 | options.log_facility, log_stderr); |
| 1631 | |
| 1632 | /* Clean up fds */ |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1633 | startup_pipe = REEXEC_STARTUP_PIPE_FD; |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1634 | close(config_s[1]); |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1635 | close(REEXEC_CONFIG_PASS_FD); |
| 1636 | newsock = sock_out = sock_in = dup(STDIN_FILENO); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1637 | if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { |
| 1638 | dup2(fd, STDIN_FILENO); |
| 1639 | dup2(fd, STDOUT_FILENO); |
| 1640 | if (fd > STDERR_FILENO) |
| 1641 | close(fd); |
| 1642 | } |
Damien Miller | 035a5b4 | 2004-06-26 08:16:31 +1000 | [diff] [blame] | 1643 | debug("rexec cleanup in %d out %d newsock %d pipe %d sock %d", |
| 1644 | sock_in, sock_out, newsock, startup_pipe, config_s[0]); |
Darren Tucker | 645ab75 | 2004-06-25 13:33:20 +1000 | [diff] [blame] | 1645 | } |
| 1646 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1647 | /* |
| 1648 | * Disable the key regeneration alarm. We will not regenerate the |
| 1649 | * key since we are no longer in a position to give it to anyone. We |
| 1650 | * will not restart on SIGHUP since it no longer makes sense. |
| 1651 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1652 | alarm(0); |
| 1653 | signal(SIGALRM, SIG_DFL); |
| 1654 | signal(SIGHUP, SIG_DFL); |
| 1655 | signal(SIGTERM, SIG_DFL); |
| 1656 | signal(SIGQUIT, SIG_DFL); |
| 1657 | signal(SIGCHLD, SIG_DFL); |
Damien Miller | 4e0f5e1 | 2000-08-29 11:05:50 +1100 | [diff] [blame] | 1658 | signal(SIGINT, SIG_DFL); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1659 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1660 | /* |
| 1661 | * Register our connection. This turns encryption off because we do |
| 1662 | * not have a key. |
| 1663 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1664 | packet_set_connection(sock_in, sock_out); |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 1665 | packet_set_server(); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1666 | |
Damien Miller | 4f1d6b2 | 2005-05-26 11:59:32 +1000 | [diff] [blame] | 1667 | /* Set SO_KEEPALIVE if requested. */ |
| 1668 | if (options.tcp_keep_alive && packet_connection_is_on_socket() && |
| 1669 | setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) < 0) |
| 1670 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); |
| 1671 | |
Damien Miller | 677257f | 2005-06-17 12:55:03 +1000 | [diff] [blame] | 1672 | if ((remote_port = get_remote_port()) < 0) { |
| 1673 | debug("get_remote_port failed"); |
| 1674 | cleanup_exit(255); |
| 1675 | } |
Damien Miller | 4d3fd54 | 2005-11-05 15:13:24 +1100 | [diff] [blame] | 1676 | |
| 1677 | /* |
| 1678 | * We use get_canonical_hostname with usedns = 0 instead of |
| 1679 | * get_remote_ipaddr here so IP options will be checked. |
| 1680 | */ |
Damien Miller | eb13e55 | 2006-06-13 13:03:53 +1000 | [diff] [blame] | 1681 | (void) get_canonical_hostname(0); |
| 1682 | /* |
| 1683 | * The rest of the code depends on the fact that |
| 1684 | * get_remote_ipaddr() caches the remote ip, even if |
| 1685 | * the socket goes away. |
| 1686 | */ |
| 1687 | remote_ip = get_remote_ipaddr(); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1688 | |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 1689 | #ifdef SSH_AUDIT_EVENTS |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 1690 | audit_connection_from(remote_ip, remote_port); |
| 1691 | #endif |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1692 | #ifdef LIBWRAP |
Damien Miller | 6a4a4b9 | 2001-11-12 11:07:11 +1100 | [diff] [blame] | 1693 | /* Check whether logins are denied from this host. */ |
Darren Tucker | 586b0b9 | 2004-06-25 13:34:31 +1000 | [diff] [blame] | 1694 | if (packet_connection_is_on_socket()) { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1695 | struct request_info req; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1696 | |
Ben Lindstrom | ce89dac | 2001-09-12 16:58:04 +0000 | [diff] [blame] | 1697 | request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1698 | fromhost(&req); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1699 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1700 | if (!hosts_access(&req)) { |
Damien Miller | 6a4a4b9 | 2001-11-12 11:07:11 +1100 | [diff] [blame] | 1701 | debug("Connection refused by tcp wrapper"); |
Ben Lindstrom | 7de696e | 2001-03-29 00:45:12 +0000 | [diff] [blame] | 1702 | refuse(&req); |
Damien Miller | 6a4a4b9 | 2001-11-12 11:07:11 +1100 | [diff] [blame] | 1703 | /* NOTREACHED */ |
| 1704 | fatal("libwrap refuse returns"); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1705 | } |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1706 | } |
Damien Miller | 34132e5 | 2000-01-14 15:45:46 +1100 | [diff] [blame] | 1707 | #endif /* LIBWRAP */ |
Damien Miller | 6a4a4b9 | 2001-11-12 11:07:11 +1100 | [diff] [blame] | 1708 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1709 | /* Log the connection. */ |
| 1710 | verbose("Connection from %.500s port %d", remote_ip, remote_port); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1711 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1712 | /* |
Damien Miller | 788f212 | 2005-11-05 15:14:59 +1100 | [diff] [blame] | 1713 | * We don't want to listen forever unless the other side |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1714 | * successfully authenticates itself. So we set up an alarm which is |
| 1715 | * cleared after successful authentication. A limit of zero |
Damien Miller | 788f212 | 2005-11-05 15:14:59 +1100 | [diff] [blame] | 1716 | * 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] | 1717 | * mode; it is just annoying to have the server exit just when you |
| 1718 | * are about to discover the bug. |
| 1719 | */ |
Ben Lindstrom | 5ade9ab | 2003-08-25 01:16:21 +0000 | [diff] [blame] | 1720 | signal(SIGALRM, grace_alarm_handler); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1721 | if (!debug_flag) |
| 1722 | alarm(options.login_grace_time); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1723 | |
Damien Miller | b38eff8 | 2000-04-01 11:09:21 +1000 | [diff] [blame] | 1724 | sshd_exchange_identification(sock_in, sock_out); |
Darren Tucker | ec960f2 | 2003-08-13 20:37:05 +1000 | [diff] [blame] | 1725 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1726 | packet_set_nonblocking(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1727 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1728 | /* allocate authentication context */ |
Damien Miller | 07d86be | 2006-03-26 14:19:21 +1100 | [diff] [blame] | 1729 | authctxt = xcalloc(1, sizeof(*authctxt)); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1730 | |
Darren Tucker | f3bb434 | 2005-03-31 21:39:25 +1000 | [diff] [blame] | 1731 | authctxt->loginmsg = &loginmsg; |
| 1732 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1733 | /* XXX global for cleanup, access from other modules */ |
| 1734 | the_authctxt = authctxt; |
| 1735 | |
Darren Tucker | 5c14c73 | 2005-01-24 21:55:49 +1100 | [diff] [blame] | 1736 | /* prepare buffer to collect messages to display to user after login */ |
| 1737 | buffer_init(&loginmsg); |
| 1738 | |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1739 | if (use_privsep) |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1740 | if (privsep_preauth(authctxt) == 1) |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1741 | goto authenticated; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1742 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1743 | /* perform the key exchange */ |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1744 | /* authenticate user and start session */ |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 1745 | if (compat20) { |
| 1746 | do_ssh2_kex(); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1747 | do_authentication2(authctxt); |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 1748 | } else { |
| 1749 | do_ssh1_kex(); |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1750 | do_authentication(authctxt); |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 1751 | } |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1752 | /* |
| 1753 | * If we use privilege separation, the unprivileged child transfers |
| 1754 | * the current keystate and exits |
| 1755 | */ |
| 1756 | if (use_privsep) { |
Ben Lindstrom | 7339b2a | 2002-05-15 16:25:01 +0000 | [diff] [blame] | 1757 | mm_send_keystate(pmonitor); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1758 | exit(0); |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1759 | } |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1760 | |
| 1761 | authenticated: |
Damien Miller | 7bff1a9 | 2005-12-24 14:59:12 +1100 | [diff] [blame] | 1762 | /* |
| 1763 | * Cancel the alarm we set to limit the time taken for |
| 1764 | * authentication. |
| 1765 | */ |
| 1766 | alarm(0); |
| 1767 | signal(SIGALRM, SIG_DFL); |
| 1768 | if (startup_pipe != -1) { |
| 1769 | close(startup_pipe); |
| 1770 | startup_pipe = -1; |
| 1771 | } |
| 1772 | |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 1773 | #ifdef SSH_AUDIT_EVENTS |
| 1774 | audit_event(SSH_AUTH_SUCCESS); |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 1775 | #endif |
| 1776 | |
Ben Lindstrom | 6328ab3 | 2002-03-22 02:54:23 +0000 | [diff] [blame] | 1777 | /* |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1778 | * In privilege separation, we fork another child and prepare |
| 1779 | * file descriptor passing. |
| 1780 | */ |
| 1781 | if (use_privsep) { |
Ben Lindstrom | 943481c | 2002-03-22 03:43:46 +0000 | [diff] [blame] | 1782 | privsep_postauth(authctxt); |
| 1783 | /* the monitor process [priv] will not return */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1784 | if (!compat20) |
| 1785 | destroy_sensitive_data(); |
| 1786 | } |
Ben Lindstrom | 73ab9ba | 2002-03-22 01:27:35 +0000 | [diff] [blame] | 1787 | |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 1788 | /* Start session. */ |
Ben Lindstrom | 73ab9ba | 2002-03-22 01:27:35 +0000 | [diff] [blame] | 1789 | do_authenticated(authctxt); |
| 1790 | |
Damien Miller | 3a5b023 | 2002-03-13 13:19:42 +1100 | [diff] [blame] | 1791 | /* The connection has been terminated. */ |
| 1792 | verbose("Closing connection to %.100s", remote_ip); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1793 | |
Damien Miller | beb4ba5 | 1999-12-28 15:09:35 +1100 | [diff] [blame] | 1794 | #ifdef USE_PAM |
Damien Miller | 4e448a3 | 2003-05-14 15:11:48 +1000 | [diff] [blame] | 1795 | if (options.use_pam) |
| 1796 | finish_pam(); |
Damien Miller | beb4ba5 | 1999-12-28 15:09:35 +1100 | [diff] [blame] | 1797 | #endif /* USE_PAM */ |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1798 | |
Darren Tucker | 2b59a6d | 2005-03-06 22:38:51 +1100 | [diff] [blame] | 1799 | #ifdef SSH_AUDIT_EVENTS |
| 1800 | PRIVSEP(audit_event(SSH_CONNECTION_CLOSE)); |
| 1801 | #endif |
| 1802 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1803 | packet_close(); |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1804 | |
| 1805 | if (use_privsep) |
| 1806 | mm_terminate(); |
| 1807 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1808 | exit(0); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1809 | } |
| 1810 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1811 | /* |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1812 | * Decrypt session_key_int using our private server key and private host key |
| 1813 | * (key with larger modulus first). |
| 1814 | */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1815 | int |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1816 | ssh1_session_key(BIGNUM *session_key_int) |
| 1817 | { |
| 1818 | int rsafail = 0; |
| 1819 | |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1820 | if (BN_cmp(sensitive_data.server_key->rsa->n, |
| 1821 | sensitive_data.ssh1_host_key->rsa->n) > 0) { |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1822 | /* Server key has bigger modulus. */ |
| 1823 | if (BN_num_bits(sensitive_data.server_key->rsa->n) < |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1824 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + |
| 1825 | SSH_KEY_BITS_RESERVED) { |
| 1826 | fatal("do_connection: %s: " |
| 1827 | "server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d", |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1828 | get_remote_ipaddr(), |
| 1829 | BN_num_bits(sensitive_data.server_key->rsa->n), |
| 1830 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), |
| 1831 | SSH_KEY_BITS_RESERVED); |
| 1832 | } |
| 1833 | if (rsa_private_decrypt(session_key_int, session_key_int, |
| 1834 | sensitive_data.server_key->rsa) <= 0) |
| 1835 | rsafail++; |
| 1836 | if (rsa_private_decrypt(session_key_int, session_key_int, |
| 1837 | sensitive_data.ssh1_host_key->rsa) <= 0) |
| 1838 | rsafail++; |
| 1839 | } else { |
| 1840 | /* Host key has bigger modulus (or they are equal). */ |
| 1841 | if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) < |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 1842 | BN_num_bits(sensitive_data.server_key->rsa->n) + |
| 1843 | SSH_KEY_BITS_RESERVED) { |
| 1844 | fatal("do_connection: %s: " |
| 1845 | "host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d", |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1846 | get_remote_ipaddr(), |
| 1847 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), |
| 1848 | BN_num_bits(sensitive_data.server_key->rsa->n), |
| 1849 | SSH_KEY_BITS_RESERVED); |
| 1850 | } |
| 1851 | if (rsa_private_decrypt(session_key_int, session_key_int, |
| 1852 | sensitive_data.ssh1_host_key->rsa) < 0) |
| 1853 | rsafail++; |
| 1854 | if (rsa_private_decrypt(session_key_int, session_key_int, |
| 1855 | sensitive_data.server_key->rsa) < 0) |
| 1856 | rsafail++; |
| 1857 | } |
| 1858 | return (rsafail); |
| 1859 | } |
| 1860 | /* |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1861 | * SSH1 key exchange |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1862 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 1863 | static void |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1864 | do_ssh1_kex(void) |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1865 | { |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1866 | int i, len; |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 1867 | int rsafail = 0; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1868 | BIGNUM *session_key_int; |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 1869 | u_char session_key[SSH_SESSION_KEY_LENGTH]; |
| 1870 | u_char cookie[8]; |
| 1871 | u_int cipher_type, auth_mask, protocol_flags; |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 1872 | u_int32_t rnd = 0; |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1873 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1874 | /* |
| 1875 | * Generate check bytes that the client must send back in the user |
| 1876 | * packet in order for it to be accepted; this is used to defy ip |
| 1877 | * spoofing attacks. Note that this only works against somebody |
| 1878 | * doing IP spoofing from a remote machine; any machine on the local |
| 1879 | * network can still see outgoing packets and catch the random |
| 1880 | * cookie. This only affects rhosts authentication, and this is one |
| 1881 | * of the reasons why it is inherently insecure. |
| 1882 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1883 | for (i = 0; i < 8; i++) { |
| 1884 | if (i % 4 == 0) |
Ben Lindstrom | 5a9d0ea | 2002-07-04 00:12:53 +0000 | [diff] [blame] | 1885 | rnd = arc4random(); |
| 1886 | cookie[i] = rnd & 0xff; |
| 1887 | rnd >>= 8; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1888 | } |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1889 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1890 | /* |
| 1891 | * Send our public key. We include in the packet 64 bits of random |
| 1892 | * data that must be matched in the reply in order to prevent IP |
| 1893 | * spoofing. |
| 1894 | */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1895 | packet_start(SSH_SMSG_PUBLIC_KEY); |
| 1896 | for (i = 0; i < 8; i++) |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1897 | packet_put_char(cookie[i]); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1898 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1899 | /* Store our public server RSA key. */ |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1900 | packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n)); |
| 1901 | packet_put_bignum(sensitive_data.server_key->rsa->e); |
| 1902 | packet_put_bignum(sensitive_data.server_key->rsa->n); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1903 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1904 | /* Store our public host RSA key. */ |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1905 | packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); |
| 1906 | packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e); |
| 1907 | packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n); |
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 | /* Put protocol flags. */ |
| 1910 | packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1911 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1912 | /* Declare which ciphers we support. */ |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1913 | packet_put_int(cipher_mask_ssh1(0)); |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1914 | |
| 1915 | /* Declare supported authentication types. */ |
| 1916 | auth_mask = 0; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1917 | if (options.rhosts_rsa_authentication) |
| 1918 | auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA; |
| 1919 | if (options.rsa_authentication) |
| 1920 | auth_mask |= 1 << SSH_AUTH_RSA; |
Ben Lindstrom | 551ea37 | 2001-06-05 18:56:16 +0000 | [diff] [blame] | 1921 | if (options.challenge_response_authentication == 1) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1922 | auth_mask |= 1 << SSH_AUTH_TIS; |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1923 | if (options.password_authentication) |
| 1924 | auth_mask |= 1 << SSH_AUTH_PASSWORD; |
| 1925 | packet_put_int(auth_mask); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1926 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1927 | /* Send the packet and wait for it to be sent. */ |
| 1928 | packet_send(); |
| 1929 | packet_write_wait(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1930 | |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 1931 | debug("Sent %d bit server key and %d bit host key.", |
| 1932 | BN_num_bits(sensitive_data.server_key->rsa->n), |
| 1933 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1934 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1935 | /* Read clients reply (cipher type and session key). */ |
Damien Miller | dff5099 | 2002-01-22 23:16:32 +1100 | [diff] [blame] | 1936 | packet_read_expect(SSH_CMSG_SESSION_KEY); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1937 | |
Damien Miller | 50945fa | 1999-12-09 10:31:37 +1100 | [diff] [blame] | 1938 | /* Get cipher type and check whether we accept this. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1939 | cipher_type = packet_get_char(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1940 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 1941 | if (!(cipher_mask_ssh1(0) & (1 << cipher_type))) |
Damien Miller | 50945fa | 1999-12-09 10:31:37 +1100 | [diff] [blame] | 1942 | packet_disconnect("Warning: client selects unsupported cipher."); |
| 1943 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1944 | /* Get check bytes from the packet. These must match those we |
| 1945 | sent earlier with the public key packet. */ |
| 1946 | for (i = 0; i < 8; i++) |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 1947 | if (cookie[i] != packet_get_char()) |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1948 | packet_disconnect("IP Spoofing check bytes do not match."); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1949 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1950 | debug("Encryption type: %.200s", cipher_name(cipher_type)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1951 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1952 | /* Get the encrypted integer. */ |
Damien Miller | da75516 | 2002-01-22 23:09:22 +1100 | [diff] [blame] | 1953 | if ((session_key_int = BN_new()) == NULL) |
| 1954 | fatal("do_ssh1_kex: BN_new failed"); |
Damien Miller | d432ccf | 2002-01-22 23:14:44 +1100 | [diff] [blame] | 1955 | packet_get_bignum(session_key_int); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1956 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 1957 | protocol_flags = packet_get_int(); |
| 1958 | packet_set_protocol_flags(protocol_flags); |
Damien Miller | 48b03fc | 2002-01-22 23:11:40 +1100 | [diff] [blame] | 1959 | packet_check_eom(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 1960 | |
Ben Lindstrom | abcb145 | 2002-03-22 01:10:21 +0000 | [diff] [blame] | 1961 | /* Decrypt session_key_int using host/server keys */ |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 1962 | rsafail = PRIVSEP(ssh1_session_key(session_key_int)); |
| 1963 | |
Damien Miller | 5428f64 | 1999-11-25 11:54:57 +1100 | [diff] [blame] | 1964 | /* |
| 1965 | * Extract session key from the decrypted integer. The key is in the |
| 1966 | * least significant 256 bits of the integer; the first byte of the |
| 1967 | * key is in the highest bits. |
| 1968 | */ |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 1969 | if (!rsafail) { |
| 1970 | BN_mask_bits(session_key_int, sizeof(session_key) * 8); |
| 1971 | len = BN_num_bytes(session_key_int); |
Damien Miller | eccb9de | 2005-06-17 12:59:34 +1000 | [diff] [blame] | 1972 | if (len < 0 || (u_int)len > sizeof(session_key)) { |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 1973 | error("do_connection: bad session key len from %s: " |
Ben Lindstrom | 31ca54a | 2001-02-09 02:11:24 +0000 | [diff] [blame] | 1974 | "session_key_int %d > sizeof(session_key) %lu", |
| 1975 | get_remote_ipaddr(), len, (u_long)sizeof(session_key)); |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 1976 | rsafail++; |
| 1977 | } else { |
| 1978 | memset(session_key, 0, sizeof(session_key)); |
| 1979 | BN_bn2bin(session_key_int, |
| 1980 | session_key + sizeof(session_key) - len); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 1981 | |
Darren Tucker | e14e005 | 2004-05-13 16:30:44 +1000 | [diff] [blame] | 1982 | derive_ssh1_session_id( |
Darren Tucker | fc95970 | 2004-07-17 16:12:08 +1000 | [diff] [blame] | 1983 | sensitive_data.ssh1_host_key->rsa->n, |
Darren Tucker | e14e005 | 2004-05-13 16:30:44 +1000 | [diff] [blame] | 1984 | sensitive_data.server_key->rsa->n, |
| 1985 | cookie, session_id); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 1986 | /* |
| 1987 | * Xor the first 16 bytes of the session key with the |
| 1988 | * session id. |
| 1989 | */ |
| 1990 | for (i = 0; i < 16; i++) |
| 1991 | session_key[i] ^= session_id[i]; |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 1992 | } |
| 1993 | } |
| 1994 | if (rsafail) { |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 1995 | int bytes = BN_num_bytes(session_key_int); |
Ben Lindstrom | 13c5d3b | 2002-02-26 18:00:48 +0000 | [diff] [blame] | 1996 | u_char *buf = xmalloc(bytes); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 1997 | MD5_CTX md; |
| 1998 | |
Damien Miller | 996acd2 | 2003-04-09 20:59:48 +1000 | [diff] [blame] | 1999 | logit("do_connection: generating a fake encryption key"); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 2000 | BN_bn2bin(session_key_int, buf); |
| 2001 | MD5_Init(&md); |
| 2002 | MD5_Update(&md, buf, bytes); |
| 2003 | MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); |
| 2004 | MD5_Final(session_key, &md); |
| 2005 | MD5_Init(&md); |
| 2006 | MD5_Update(&md, session_key, 16); |
| 2007 | MD5_Update(&md, buf, bytes); |
| 2008 | MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); |
| 2009 | MD5_Final(session_key + 16, &md); |
| 2010 | memset(buf, 0, bytes); |
| 2011 | xfree(buf); |
Ben Lindstrom | 941ac82 | 2001-03-05 06:25:23 +0000 | [diff] [blame] | 2012 | for (i = 0; i < 16; i++) |
| 2013 | session_id[i] = session_key[i] ^ session_key[i + 16]; |
Damien Miller | 7650bc6 | 2001-01-30 09:27:26 +1100 | [diff] [blame] | 2014 | } |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 2015 | /* Destroy the private and public keys. No longer. */ |
Damien Miller | 3a5b023 | 2002-03-13 13:19:42 +1100 | [diff] [blame] | 2016 | destroy_sensitive_data(); |
Ben Lindstrom | eb648a7 | 2001-03-05 06:00:29 +0000 | [diff] [blame] | 2017 | |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 2018 | if (use_privsep) |
| 2019 | mm_ssh1_session_id(session_id); |
| 2020 | |
Damien Miller | 396691a | 2000-01-20 22:44:08 +1100 | [diff] [blame] | 2021 | /* Destroy the decrypted integer. It is no longer needed. */ |
| 2022 | BN_clear_free(session_key_int); |
| 2023 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2024 | /* Set the session key. From this on all communications will be encrypted. */ |
| 2025 | packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2026 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2027 | /* Destroy our copy of the session key. It is no longer needed. */ |
| 2028 | memset(session_key, 0, sizeof(session_key)); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2029 | |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2030 | debug("Received session key; encryption turned on."); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2031 | |
Ben Lindstrom | f666fec | 2002-06-06 19:51:58 +0000 | [diff] [blame] | 2032 | /* Send an acknowledgment packet. Note that this packet is sent encrypted. */ |
Damien Miller | 95def09 | 1999-11-25 00:26:21 +1100 | [diff] [blame] | 2033 | packet_start(SSH_SMSG_SUCCESS); |
| 2034 | packet_send(); |
| 2035 | packet_write_wait(); |
Damien Miller | d4a8b7e | 1999-10-27 13:42:43 +1000 | [diff] [blame] | 2036 | } |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2037 | |
| 2038 | /* |
| 2039 | * SSH2 key exchange: diffie-hellman-group1-sha1 |
| 2040 | */ |
Ben Lindstrom | bba8121 | 2001-06-25 05:01:22 +0000 | [diff] [blame] | 2041 | static void |
Ben Lindstrom | 46c1622 | 2000-12-22 01:43:59 +0000 | [diff] [blame] | 2042 | do_ssh2_kex(void) |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2043 | { |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2044 | Kex *kex; |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2045 | |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 2046 | if (options.ciphers != NULL) { |
Damien Miller | 4af5130 | 2000-04-16 11:18:38 +1000 | [diff] [blame] | 2047 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
Damien Miller | 7892879 | 2000-04-12 20:17:38 +1000 | [diff] [blame] | 2048 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; |
| 2049 | } |
Damien Miller | a0ff466 | 2001-03-30 10:49:35 +1000 | [diff] [blame] | 2050 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
| 2051 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); |
| 2052 | myproposal[PROPOSAL_ENC_ALGS_STOC] = |
| 2053 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); |
| 2054 | |
Ben Lindstrom | 06b33aa | 2001-02-15 03:01:59 +0000 | [diff] [blame] | 2055 | if (options.macs != NULL) { |
| 2056 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = |
| 2057 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; |
| 2058 | } |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 2059 | if (options.compression == COMP_NONE) { |
Ben Lindstrom | 23e0f66 | 2002-06-21 01:09:47 +0000 | [diff] [blame] | 2060 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
| 2061 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; |
Damien Miller | 9786e6e | 2005-07-26 21:54:56 +1000 | [diff] [blame] | 2062 | } else if (options.compression == COMP_DELAYED) { |
| 2063 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
| 2064 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com"; |
Ben Lindstrom | 23e0f66 | 2002-06-21 01:09:47 +0000 | [diff] [blame] | 2065 | } |
Damien Miller | f0b15df | 2006-03-26 13:59:20 +1100 | [diff] [blame] | 2066 | |
Damien Miller | 0bc1bd8 | 2000-11-13 22:57:25 +1100 | [diff] [blame] | 2067 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types(); |
| 2068 | |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 2069 | /* start key exchange */ |
Ben Lindstrom | 238abf6 | 2001-04-04 17:52:53 +0000 | [diff] [blame] | 2070 | kex = kex_setup(myproposal); |
Damien Miller | 8e7fb33 | 2003-02-24 12:03:03 +1100 | [diff] [blame] | 2071 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; |
Damien Miller | f675fc4 | 2004-06-15 10:30:09 +1000 | [diff] [blame] | 2072 | kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; |
Damien Miller | 8e7fb33 | 2003-02-24 12:03:03 +1100 | [diff] [blame] | 2073 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; |
Damien Miller | a63128d | 2006-03-15 12:08:28 +1100 | [diff] [blame] | 2074 | kex->kex[KEX_DH_GEX_SHA256] = kexgex_server; |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 2075 | kex->server = 1; |
| 2076 | kex->client_version_string=client_version_string; |
| 2077 | kex->server_version_string=server_version_string; |
| 2078 | kex->load_host_key=&get_hostkey_by_type; |
Ben Lindstrom | 7a2073c | 2002-03-22 02:30:41 +0000 | [diff] [blame] | 2079 | kex->host_key_index=&get_hostkey_index; |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2080 | |
Ben Lindstrom | 8ac9106 | 2001-04-04 17:57:54 +0000 | [diff] [blame] | 2081 | xxx_kex = kex; |
| 2082 | |
Ben Lindstrom | be2cc43 | 2001-04-04 23:46:07 +0000 | [diff] [blame] | 2083 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 2084 | |
Ben Lindstrom | 2d90e00 | 2001-04-04 02:00:54 +0000 | [diff] [blame] | 2085 | session_id2 = kex->session_id; |
| 2086 | session_id2_len = kex->session_id_len; |
| 2087 | |
Damien Miller | 874d77b | 2000-10-14 16:23:11 +1100 | [diff] [blame] | 2088 | #ifdef DEBUG_KEXDH |
| 2089 | /* send 1st encrypted/maced/compressed message */ |
| 2090 | packet_start(SSH2_MSG_IGNORE); |
| 2091 | packet_put_cstring("markus"); |
| 2092 | packet_send(); |
| 2093 | packet_write_wait(); |
| 2094 | #endif |
Ben Lindstrom | 20d7c7b | 2001-04-04 01:56:17 +0000 | [diff] [blame] | 2095 | debug("KEX done"); |
Damien Miller | efb4afe | 2000-04-12 18:45:05 +1000 | [diff] [blame] | 2096 | } |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 2097 | |
| 2098 | /* server specific fatal cleanup */ |
| 2099 | void |
| 2100 | cleanup_exit(int i) |
| 2101 | { |
| 2102 | if (the_authctxt) |
| 2103 | do_cleanup(the_authctxt); |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 2104 | #ifdef SSH_AUDIT_EVENTS |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 2105 | /* done after do_cleanup so it can cancel the PAM auth 'thread' */ |
| 2106 | if (!use_privsep || mm_is_monitor()) |
Darren Tucker | 2e0cf0d | 2005-02-08 21:52:47 +1100 | [diff] [blame] | 2107 | audit_event(SSH_CONNECTION_ABANDON); |
Darren Tucker | 269a1ea | 2005-02-03 00:20:53 +1100 | [diff] [blame] | 2108 | #endif |
Darren Tucker | 3e33cec | 2003-10-02 16:12:36 +1000 | [diff] [blame] | 2109 | _exit(i); |
| 2110 | } |