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8efc0c15 | 1 | /* |
5260325f | 2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland | |
4 | * All rights reserved | |
bcbf86ec | 5 | * This program is the ssh daemon. It listens for connections from clients, |
6 | * and performs authentication, executes use commands or shell, and forwards | |
5260325f | 7 | * information to/from the application to the user client over an encrypted |
bcbf86ec | 8 | * connection. This can also handle forwarding of X11, TCP/IP, and |
9 | * authentication agent connections. | |
e78a59f5 | 10 | * |
bcbf86ec | 11 | * As far as I am concerned, the code I have written for this software |
12 | * can be used freely for any purpose. Any derived versions of this | |
13 | * software must be clearly marked as such, and if the derived work is | |
14 | * incompatible with the protocol description in the RFC file, it must be | |
15 | * called by a name other than "ssh" or "Secure Shell". | |
16 | * | |
17 | * SSH2 implementation: | |
1853d1ef | 18 | * Privilege Separation: |
bcbf86ec | 19 | * |
1853d1ef | 20 | * Copyright (c) 2000, 2001, 2002 Markus Friedl. All rights reserved. |
21 | * Copyright (c) 2002 Niels Provos. All rights reserved. | |
bcbf86ec | 22 | * |
23 | * Redistribution and use in source and binary forms, with or without | |
24 | * modification, are permitted provided that the following conditions | |
25 | * are met: | |
26 | * 1. Redistributions of source code must retain the above copyright | |
27 | * notice, this list of conditions and the following disclaimer. | |
28 | * 2. Redistributions in binary form must reproduce the above copyright | |
29 | * notice, this list of conditions and the following disclaimer in the | |
30 | * documentation and/or other materials provided with the distribution. | |
31 | * | |
32 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
33 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
34 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
35 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
36 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
37 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
38 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
39 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
40 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
41 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
5260325f | 42 | */ |
8efc0c15 | 43 | |
44 | #include "includes.h" | |
07200973 | 45 | RCSID("$OpenBSD: sshd.c,v 1.312 2005/07/25 11:59:40 markus Exp $"); |
8efc0c15 | 46 | |
42f11eb2 | 47 | #include <openssl/dh.h> |
48 | #include <openssl/bn.h> | |
436c347c | 49 | #include <openssl/md5.h> |
1853d1ef | 50 | #include <openssl/rand.h> |
6e879cb4 | 51 | #ifdef HAVE_SECUREWARE |
52 | #include <sys/security.h> | |
53 | #include <prot.h> | |
54 | #endif | |
42f11eb2 | 55 | |
56 | #include "ssh.h" | |
57 | #include "ssh1.h" | |
58 | #include "ssh2.h" | |
8efc0c15 | 59 | #include "xmalloc.h" |
60 | #include "rsa.h" | |
1729c161 | 61 | #include "sshpty.h" |
8efc0c15 | 62 | #include "packet.h" |
42f11eb2 | 63 | #include "log.h" |
8efc0c15 | 64 | #include "servconf.h" |
65 | #include "uidswap.h" | |
66 | #include "compat.h" | |
7368a6c8 | 67 | #include "buffer.h" |
b9a549d7 | 68 | #include "bufaux.h" |
42f11eb2 | 69 | #include "cipher.h" |
e78a59f5 | 70 | #include "kex.h" |
7368a6c8 | 71 | #include "key.h" |
94ec8c6b | 72 | #include "dh.h" |
e78a59f5 | 73 | #include "myproposal.h" |
a306f2dd | 74 | #include "authfile.h" |
42f11eb2 | 75 | #include "pathnames.h" |
76 | #include "atomicio.h" | |
77 | #include "canohost.h" | |
78 | #include "auth.h" | |
79 | #include "misc.h" | |
b9a549d7 | 80 | #include "msg.h" |
a5c9ffdb | 81 | #include "dispatch.h" |
e4d7f734 | 82 | #include "channels.h" |
1b34c1b3 | 83 | #include "session.h" |
1853d1ef | 84 | #include "monitor_mm.h" |
85 | #include "monitor.h" | |
86 | #include "monitor_wrap.h" | |
87 | #include "monitor_fdpass.h" | |
8efc0c15 | 88 | |
89 | #ifdef LIBWRAP | |
90 | #include <tcpd.h> | |
91 | #include <syslog.h> | |
92 | int allow_severity = LOG_INFO; | |
93 | int deny_severity = LOG_WARNING; | |
94 | #endif /* LIBWRAP */ | |
95 | ||
96 | #ifndef O_NOCTTY | |
97 | #define O_NOCTTY 0 | |
98 | #endif | |
99 | ||
b250e837 | 100 | /* Re-exec fds */ |
101 | #define REEXEC_DEVCRYPTO_RESERVED_FD (STDERR_FILENO + 1) | |
102 | #define REEXEC_STARTUP_PIPE_FD (STDERR_FILENO + 2) | |
103 | #define REEXEC_CONFIG_PASS_FD (STDERR_FILENO + 3) | |
104 | #define REEXEC_MIN_FREE_FD (STDERR_FILENO + 4) | |
105 | ||
260d427b | 106 | extern char *__progname; |
260d427b | 107 | |
8efc0c15 | 108 | /* Server configuration options. */ |
109 | ServerOptions options; | |
110 | ||
111 | /* Name of the server configuration file. */ | |
42f11eb2 | 112 | char *config_file_name = _PATH_SERVER_CONFIG_FILE; |
8efc0c15 | 113 | |
5260325f | 114 | /* |
115 | * Debug mode flag. This can be set on the command line. If debug | |
116 | * mode is enabled, extra debugging output will be sent to the system | |
117 | * log, the daemon will not go to background, and will exit after processing | |
118 | * the first connection. | |
119 | */ | |
8efc0c15 | 120 | int debug_flag = 0; |
121 | ||
f87f09aa | 122 | /* Flag indicating that the daemon should only test the configuration and keys. */ |
123 | int test_flag = 0; | |
124 | ||
8efc0c15 | 125 | /* Flag indicating that the daemon is being started from inetd. */ |
126 | int inetd_flag = 0; | |
127 | ||
0b6fbf03 | 128 | /* Flag indicating that sshd should not detach and become a daemon. */ |
129 | int no_daemon_flag = 0; | |
130 | ||
6a17f9c2 | 131 | /* debug goes to stderr unless inetd_flag is set */ |
132 | int log_stderr = 0; | |
133 | ||
8efc0c15 | 134 | /* Saved arguments to main(). */ |
135 | char **saved_argv; | |
4d33e531 | 136 | int saved_argc; |
8efc0c15 | 137 | |
b9a549d7 | 138 | /* re-exec */ |
139 | int rexeced_flag = 0; | |
140 | int rexec_flag = 1; | |
141 | int rexec_argc = 0; | |
142 | char **rexec_argv; | |
143 | ||
aa3378df | 144 | /* |
48e671d5 | 145 | * The sockets that the server is listening; this is used in the SIGHUP |
146 | * signal handler. | |
aa3378df | 147 | */ |
48e671d5 | 148 | #define MAX_LISTEN_SOCKS 16 |
149 | int listen_socks[MAX_LISTEN_SOCKS]; | |
150 | int num_listen_socks = 0; | |
8efc0c15 | 151 | |
aa3378df | 152 | /* |
153 | * the client's version string, passed by sshd2 in compat mode. if != NULL, | |
154 | * sshd will skip the version-number exchange | |
155 | */ | |
5260325f | 156 | char *client_version_string = NULL; |
7368a6c8 | 157 | char *server_version_string = NULL; |
8efc0c15 | 158 | |
7a37c112 | 159 | /* for rekeying XXX fixme */ |
160 | Kex *xxx_kex; | |
161 | ||
aa3378df | 162 | /* |
163 | * Any really sensitive data in the application is contained in this | |
164 | * structure. The idea is that this structure could be locked into memory so | |
165 | * that the pages do not get written into swap. However, there are some | |
166 | * problems. The private key contains BIGNUMs, and we do not (in principle) | |
167 | * have access to the internals of them, and locking just the structure is | |
168 | * not very useful. Currently, memory locking is not implemented. | |
169 | */ | |
5260325f | 170 | struct { |
cb7bd922 | 171 | Key *server_key; /* ephemeral server key */ |
fa08c86b | 172 | Key *ssh1_host_key; /* ssh1 host key */ |
173 | Key **host_keys; /* all private host keys */ | |
174 | int have_ssh1_key; | |
175 | int have_ssh2_key; | |
00be5382 | 176 | u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH]; |
8efc0c15 | 177 | } sensitive_data; |
178 | ||
aa3378df | 179 | /* |
59c97189 | 180 | * Flag indicating whether the RSA server key needs to be regenerated. |
181 | * Is set in the SIGALRM handler and cleared when the key is regenerated. | |
aa3378df | 182 | */ |
7a934d1b | 183 | static volatile sig_atomic_t key_do_regen = 0; |
8efc0c15 | 184 | |
c9130033 | 185 | /* This is set to true when a signal is received. */ |
7a934d1b | 186 | static volatile sig_atomic_t received_sighup = 0; |
187 | static volatile sig_atomic_t received_sigterm = 0; | |
8efc0c15 | 188 | |
7368a6c8 | 189 | /* session identifier, used by RSA-auth */ |
1e3b8b07 | 190 | u_char session_id[16]; |
e7c0f9d5 | 191 | |
a306f2dd | 192 | /* same for ssh2 */ |
1e3b8b07 | 193 | u_char *session_id2 = NULL; |
a27002e5 | 194 | u_int session_id2_len = 0; |
a306f2dd | 195 | |
c345cf9d | 196 | /* record remote hostname or ip */ |
1e3b8b07 | 197 | u_int utmp_len = MAXHOSTNAMELEN; |
c345cf9d | 198 | |
7ace8c3b | 199 | /* options.max_startup sized array of fd ints */ |
200 | int *startup_pipes = NULL; | |
201 | int startup_pipe; /* in child */ | |
202 | ||
1853d1ef | 203 | /* variables used for privilege separation */ |
98a58eda | 204 | int use_privsep; |
a9b33b95 | 205 | struct monitor *pmonitor = NULL; |
1853d1ef | 206 | |
2362db19 | 207 | /* global authentication context */ |
208 | Authctxt *the_authctxt = NULL; | |
209 | ||
be2ca0c9 | 210 | /* message to be displayed after login */ |
211 | Buffer loginmsg; | |
212 | ||
7368a6c8 | 213 | /* Prototypes for various functions defined later in this file. */ |
396c147e | 214 | void destroy_sensitive_data(void); |
1853d1ef | 215 | void demote_sensitive_data(void); |
c8d54615 | 216 | |
396c147e | 217 | static void do_ssh1_kex(void); |
218 | static void do_ssh2_kex(void); | |
94ec8c6b | 219 | |
48e671d5 | 220 | /* |
221 | * Close all listening sockets | |
222 | */ | |
396c147e | 223 | static void |
48e671d5 | 224 | close_listen_socks(void) |
225 | { | |
226 | int i; | |
e424e241 | 227 | |
48e671d5 | 228 | for (i = 0; i < num_listen_socks; i++) |
229 | close(listen_socks[i]); | |
230 | num_listen_socks = -1; | |
231 | } | |
232 | ||
7ace8c3b | 233 | static void |
234 | close_startup_pipes(void) | |
235 | { | |
236 | int i; | |
e424e241 | 237 | |
7ace8c3b | 238 | if (startup_pipes) |
239 | for (i = 0; i < options.max_startups; i++) | |
240 | if (startup_pipes[i] != -1) | |
241 | close(startup_pipes[i]); | |
242 | } | |
243 | ||
5260325f | 244 | /* |
245 | * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP; | |
246 | * the effect is to reread the configuration file (and to regenerate | |
247 | * the server key). | |
248 | */ | |
396c147e | 249 | static void |
5260325f | 250 | sighup_handler(int sig) |
8efc0c15 | 251 | { |
6056eb35 | 252 | int save_errno = errno; |
253 | ||
5260325f | 254 | received_sighup = 1; |
255 | signal(SIGHUP, sighup_handler); | |
6056eb35 | 256 | errno = save_errno; |
8efc0c15 | 257 | } |
258 | ||
5260325f | 259 | /* |
260 | * Called from the main program after receiving SIGHUP. | |
261 | * Restarts the server. | |
262 | */ | |
396c147e | 263 | static void |
5ca51e19 | 264 | sighup_restart(void) |
8efc0c15 | 265 | { |
bbe88b6d | 266 | logit("Received SIGHUP; restarting."); |
48e671d5 | 267 | close_listen_socks(); |
7ace8c3b | 268 | close_startup_pipes(); |
5260325f | 269 | execv(saved_argv[0], saved_argv); |
bbe88b6d | 270 | logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0], |
e424e241 | 271 | strerror(errno)); |
5260325f | 272 | exit(1); |
8efc0c15 | 273 | } |
274 | ||
5260325f | 275 | /* |
276 | * Generic signal handler for terminating signals in the master daemon. | |
5260325f | 277 | */ |
396c147e | 278 | static void |
5260325f | 279 | sigterm_handler(int sig) |
8efc0c15 | 280 | { |
c9130033 | 281 | received_sigterm = sig; |
8efc0c15 | 282 | } |
283 | ||
5260325f | 284 | /* |
285 | * SIGCHLD handler. This is called whenever a child dies. This will then | |
c9130033 | 286 | * reap any zombies left by exited children. |
5260325f | 287 | */ |
396c147e | 288 | static void |
5260325f | 289 | main_sigchld_handler(int sig) |
8efc0c15 | 290 | { |
5260325f | 291 | int save_errno = errno; |
e424e241 | 292 | pid_t pid; |
5260325f | 293 | int status; |
5ad13cd7 | 294 | |
8c38e88b | 295 | while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || |
296 | (pid < 0 && errno == EINTR)) | |
5260325f | 297 | ; |
5ad13cd7 | 298 | |
5260325f | 299 | signal(SIGCHLD, main_sigchld_handler); |
300 | errno = save_errno; | |
8efc0c15 | 301 | } |
302 | ||
5260325f | 303 | /* |
304 | * Signal handler for the alarm after the login grace period has expired. | |
305 | */ | |
396c147e | 306 | static void |
5260325f | 307 | grace_alarm_handler(int sig) |
8efc0c15 | 308 | { |
c9130033 | 309 | /* XXX no idea how fix this signal handler */ |
310 | ||
a9b33b95 | 311 | if (use_privsep && pmonitor != NULL && pmonitor->m_pid > 0) |
312 | kill(pmonitor->m_pid, SIGALRM); | |
313 | ||
5260325f | 314 | /* Log error and exit. */ |
26b9a3d2 | 315 | fatal("Timeout before authentication for %s", get_remote_ipaddr()); |
5260325f | 316 | } |
8efc0c15 | 317 | |
5260325f | 318 | /* |
319 | * Signal handler for the key regeneration alarm. Note that this | |
320 | * alarm only occurs in the daemon waiting for connections, and it does not | |
321 | * do anything with the private key or random state before forking. | |
322 | * Thus there should be no concurrency control/asynchronous execution | |
323 | * problems. | |
324 | */ | |
396c147e | 325 | static void |
cb7bd922 | 326 | generate_ephemeral_server_key(void) |
fa08c86b | 327 | { |
7fdc56c5 | 328 | u_int32_t rnd = 0; |
00be5382 | 329 | int i; |
330 | ||
cd332296 | 331 | verbose("Generating %s%d bit RSA key.", |
76ca7b01 | 332 | sensitive_data.server_key ? "new " : "", options.server_key_bits); |
fa08c86b | 333 | if (sensitive_data.server_key != NULL) |
334 | key_free(sensitive_data.server_key); | |
cd332296 | 335 | sensitive_data.server_key = key_generate(KEY_RSA1, |
76ca7b01 | 336 | options.server_key_bits); |
337 | verbose("RSA key generation complete."); | |
00be5382 | 338 | |
339 | for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) { | |
340 | if (i % 4 == 0) | |
7fdc56c5 | 341 | rnd = arc4random(); |
342 | sensitive_data.ssh1_cookie[i] = rnd & 0xff; | |
343 | rnd >>= 8; | |
00be5382 | 344 | } |
345 | arc4random_stir(); | |
fa08c86b | 346 | } |
f546c780 | 347 | |
396c147e | 348 | static void |
5260325f | 349 | key_regeneration_alarm(int sig) |
350 | { | |
351 | int save_errno = errno; | |
e424e241 | 352 | |
59c97189 | 353 | signal(SIGALRM, SIG_DFL); |
5260325f | 354 | errno = save_errno; |
59c97189 | 355 | key_do_regen = 1; |
5260325f | 356 | } |
8efc0c15 | 357 | |
396c147e | 358 | static void |
7368a6c8 | 359 | sshd_exchange_identification(int sock_in, int sock_out) |
360 | { | |
2ceb8101 | 361 | u_int i; |
362 | int mismatch; | |
7368a6c8 | 363 | int remote_major, remote_minor; |
a8be9f80 | 364 | int major, minor; |
7368a6c8 | 365 | char *s; |
366 | char buf[256]; /* Must not be larger than remote_version. */ | |
367 | char remote_version[256]; /* Must be at least as big as buf. */ | |
368 | ||
a8be9f80 | 369 | if ((options.protocol & SSH_PROTO_1) && |
370 | (options.protocol & SSH_PROTO_2)) { | |
371 | major = PROTOCOL_MAJOR_1; | |
372 | minor = 99; | |
373 | } else if (options.protocol & SSH_PROTO_2) { | |
374 | major = PROTOCOL_MAJOR_2; | |
375 | minor = PROTOCOL_MINOR_2; | |
376 | } else { | |
377 | major = PROTOCOL_MAJOR_1; | |
378 | minor = PROTOCOL_MINOR_1; | |
379 | } | |
380 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", major, minor, SSH_VERSION); | |
7368a6c8 | 381 | server_version_string = xstrdup(buf); |
382 | ||
7b390973 | 383 | /* Send our protocol version identification. */ |
384 | if (atomicio(vwrite, sock_out, server_version_string, | |
385 | strlen(server_version_string)) | |
386 | != strlen(server_version_string)) { | |
387 | logit("Could not write ident string to %s", get_remote_ipaddr()); | |
2362db19 | 388 | cleanup_exit(255); |
7b390973 | 389 | } |
390 | ||
391 | /* Read other sides version identification. */ | |
392 | memset(buf, 0, sizeof(buf)); | |
393 | for (i = 0; i < sizeof(buf) - 1; i++) { | |
394 | if (atomicio(read, sock_in, &buf[i], 1) != 1) { | |
395 | logit("Did not receive identification string from %s", | |
396 | get_remote_ipaddr()); | |
2362db19 | 397 | cleanup_exit(255); |
7368a6c8 | 398 | } |
7b390973 | 399 | if (buf[i] == '\r') { |
400 | buf[i] = 0; | |
401 | /* Kludge for F-Secure Macintosh < 1.0.2 */ | |
402 | if (i == 12 && | |
403 | strncmp(buf, "SSH-1.5-W1.0", 12) == 0) | |
7368a6c8 | 404 | break; |
7b390973 | 405 | continue; |
406 | } | |
407 | if (buf[i] == '\n') { | |
408 | buf[i] = 0; | |
409 | break; | |
7368a6c8 | 410 | } |
7368a6c8 | 411 | } |
7b390973 | 412 | buf[sizeof(buf) - 1] = 0; |
413 | client_version_string = xstrdup(buf); | |
7368a6c8 | 414 | |
415 | /* | |
416 | * Check that the versions match. In future this might accept | |
417 | * several versions and set appropriate flags to handle them. | |
418 | */ | |
419 | if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n", | |
420 | &remote_major, &remote_minor, remote_version) != 3) { | |
6ae2364d | 421 | s = "Protocol mismatch.\n"; |
dc54438a | 422 | (void) atomicio(vwrite, sock_out, s, strlen(s)); |
7368a6c8 | 423 | close(sock_in); |
424 | close(sock_out); | |
bbe88b6d | 425 | logit("Bad protocol version identification '%.100s' from %s", |
7368a6c8 | 426 | client_version_string, get_remote_ipaddr()); |
2362db19 | 427 | cleanup_exit(255); |
7368a6c8 | 428 | } |
429 | debug("Client protocol version %d.%d; client software version %.100s", | |
184eed6a | 430 | remote_major, remote_minor, remote_version); |
7368a6c8 | 431 | |
e78a59f5 | 432 | compat_datafellows(remote_version); |
433 | ||
9a87e2ac | 434 | if (datafellows & SSH_BUG_PROBE) { |
bbe88b6d | 435 | logit("probed from %s with %s. Don't panic.", |
9a87e2ac | 436 | get_remote_ipaddr(), client_version_string); |
2362db19 | 437 | cleanup_exit(255); |
9a87e2ac | 438 | } |
439 | ||
3a1c54d4 | 440 | if (datafellows & SSH_BUG_SCANNER) { |
bbe88b6d | 441 | logit("scanned from %s with %s. Don't panic.", |
3a1c54d4 | 442 | get_remote_ipaddr(), client_version_string); |
2362db19 | 443 | cleanup_exit(255); |
3a1c54d4 | 444 | } |
445 | ||
a8be9f80 | 446 | mismatch = 0; |
6aacefa7 | 447 | switch (remote_major) { |
7368a6c8 | 448 | case 1: |
a306f2dd | 449 | if (remote_minor == 99) { |
450 | if (options.protocol & SSH_PROTO_2) | |
451 | enable_compat20(); | |
452 | else | |
453 | mismatch = 1; | |
454 | break; | |
455 | } | |
a8be9f80 | 456 | if (!(options.protocol & SSH_PROTO_1)) { |
457 | mismatch = 1; | |
458 | break; | |
459 | } | |
7368a6c8 | 460 | if (remote_minor < 3) { |
089fbbd2 | 461 | packet_disconnect("Your ssh version is too old and " |
7368a6c8 | 462 | "is no longer supported. Please install a newer version."); |
463 | } else if (remote_minor == 3) { | |
464 | /* note that this disables agent-forwarding */ | |
465 | enable_compat13(); | |
466 | } | |
a8be9f80 | 467 | break; |
e78a59f5 | 468 | case 2: |
a8be9f80 | 469 | if (options.protocol & SSH_PROTO_2) { |
e78a59f5 | 470 | enable_compat20(); |
471 | break; | |
472 | } | |
473 | /* FALLTHROUGH */ | |
6ae2364d | 474 | default: |
a8be9f80 | 475 | mismatch = 1; |
476 | break; | |
477 | } | |
478 | chop(server_version_string); | |
a8be9f80 | 479 | debug("Local version string %.200s", server_version_string); |
480 | ||
481 | if (mismatch) { | |
7368a6c8 | 482 | s = "Protocol major versions differ.\n"; |
dc54438a | 483 | (void) atomicio(vwrite, sock_out, s, strlen(s)); |
7368a6c8 | 484 | close(sock_in); |
485 | close(sock_out); | |
bbe88b6d | 486 | logit("Protocol major versions differ for %s: %.200s vs. %.200s", |
a8be9f80 | 487 | get_remote_ipaddr(), |
488 | server_version_string, client_version_string); | |
2362db19 | 489 | cleanup_exit(255); |
7368a6c8 | 490 | } |
a306f2dd | 491 | } |
492 | ||
fa08c86b | 493 | /* Destroy the host and server keys. They will no longer be needed. */ |
a306f2dd | 494 | void |
495 | destroy_sensitive_data(void) | |
496 | { | |
fa08c86b | 497 | int i; |
498 | ||
499 | if (sensitive_data.server_key) { | |
500 | key_free(sensitive_data.server_key); | |
501 | sensitive_data.server_key = NULL; | |
502 | } | |
184eed6a | 503 | for (i = 0; i < options.num_host_key_files; i++) { |
fa08c86b | 504 | if (sensitive_data.host_keys[i]) { |
505 | key_free(sensitive_data.host_keys[i]); | |
506 | sensitive_data.host_keys[i] = NULL; | |
507 | } | |
508 | } | |
509 | sensitive_data.ssh1_host_key = NULL; | |
00be5382 | 510 | memset(sensitive_data.ssh1_cookie, 0, SSH_SESSION_KEY_LENGTH); |
fa08c86b | 511 | } |
fa08c86b | 512 | |
1853d1ef | 513 | /* Demote private to public keys for network child */ |
514 | void | |
515 | demote_sensitive_data(void) | |
516 | { | |
517 | Key *tmp; | |
518 | int i; | |
519 | ||
520 | if (sensitive_data.server_key) { | |
521 | tmp = key_demote(sensitive_data.server_key); | |
522 | key_free(sensitive_data.server_key); | |
523 | sensitive_data.server_key = tmp; | |
524 | } | |
525 | ||
526 | for (i = 0; i < options.num_host_key_files; i++) { | |
527 | if (sensitive_data.host_keys[i]) { | |
528 | tmp = key_demote(sensitive_data.host_keys[i]); | |
529 | key_free(sensitive_data.host_keys[i]); | |
530 | sensitive_data.host_keys[i] = tmp; | |
531 | if (tmp->type == KEY_RSA1) | |
532 | sensitive_data.ssh1_host_key = tmp; | |
533 | } | |
534 | } | |
535 | ||
536 | /* We do not clear ssh1_host key and cookie. XXX - Okay Niels? */ | |
537 | } | |
538 | ||
51aeb639 | 539 | static void |
1853d1ef | 540 | privsep_preauth_child(void) |
541 | { | |
7fdc56c5 | 542 | u_int32_t rnd[256]; |
6ded293b | 543 | gid_t gidset[1]; |
2ea6de2b | 544 | struct passwd *pw; |
e424e241 | 545 | int i; |
1853d1ef | 546 | |
547 | /* Enable challenge-response authentication for privilege separation */ | |
548 | privsep_challenge_enable(); | |
549 | ||
550 | for (i = 0; i < 256; i++) | |
7fdc56c5 | 551 | rnd[i] = arc4random(); |
552 | RAND_seed(rnd, sizeof(rnd)); | |
1853d1ef | 553 | |
554 | /* Demote the private keys to public keys. */ | |
555 | demote_sensitive_data(); | |
556 | ||
2ea6de2b | 557 | if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL) |
cdc4fc39 | 558 | fatal("Privilege separation user %s does not exist", |
559 | SSH_PRIVSEP_USER); | |
2ea6de2b | 560 | memset(pw->pw_passwd, 0, strlen(pw->pw_passwd)); |
561 | endpwent(); | |
562 | ||
343288b8 | 563 | /* Change our root directory */ |
1c352e97 | 564 | if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1) |
565 | fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR, | |
566 | strerror(errno)); | |
1853d1ef | 567 | if (chdir("/") == -1) |
edfb66cb | 568 | fatal("chdir(\"/\"): %s", strerror(errno)); |
762715ce | 569 | |
1853d1ef | 570 | /* Drop our privileges */ |
2ea6de2b | 571 | debug3("privsep user:group %u:%u", (u_int)pw->pw_uid, |
572 | (u_int)pw->pw_gid); | |
87809a1f | 573 | #if 0 |
6ff58a4b | 574 | /* XXX not ready, too heavy after chroot */ |
2ea6de2b | 575 | do_setusercontext(pw); |
87809a1f | 576 | #else |
577 | gidset[0] = pw->pw_gid; | |
87809a1f | 578 | if (setgroups(1, gidset) < 0) |
579 | fatal("setgroups: %.100s", strerror(errno)); | |
580 | permanently_set_uid(pw); | |
581 | #endif | |
1853d1ef | 582 | } |
583 | ||
2362db19 | 584 | static int |
585 | privsep_preauth(Authctxt *authctxt) | |
1853d1ef | 586 | { |
1853d1ef | 587 | int status; |
324bf712 | 588 | pid_t pid; |
1853d1ef | 589 | |
324bf712 | 590 | /* Set up unprivileged child process to deal with network data */ |
b5a28cbc | 591 | pmonitor = monitor_init(); |
324bf712 | 592 | /* Store a pointer to the kex for later rekeying */ |
b5a28cbc | 593 | pmonitor->m_pkex = &xxx_kex; |
324bf712 | 594 | |
595 | pid = fork(); | |
596 | if (pid == -1) { | |
597 | fatal("fork of unprivileged child failed"); | |
598 | } else if (pid != 0) { | |
c457707e | 599 | debug2("Network child is on pid %ld", (long)pid); |
324bf712 | 600 | |
b5a28cbc | 601 | close(pmonitor->m_recvfd); |
a9b33b95 | 602 | pmonitor->m_pid = pid; |
2362db19 | 603 | monitor_child_preauth(authctxt, pmonitor); |
b5a28cbc | 604 | close(pmonitor->m_sendfd); |
324bf712 | 605 | |
606 | /* Sync memory */ | |
b5a28cbc | 607 | monitor_sync(pmonitor); |
324bf712 | 608 | |
609 | /* Wait for the child's exit status */ | |
8c38e88b | 610 | while (waitpid(pid, &status, 0) < 0) |
611 | if (errno != EINTR) | |
612 | break; | |
2362db19 | 613 | return (1); |
324bf712 | 614 | } else { |
615 | /* child */ | |
616 | ||
b5a28cbc | 617 | close(pmonitor->m_sendfd); |
324bf712 | 618 | |
619 | /* Demote the child */ | |
620 | if (getuid() == 0 || geteuid() == 0) | |
621 | privsep_preauth_child(); | |
47c36e5b | 622 | setproctitle("%s", "[net]"); |
324bf712 | 623 | } |
2362db19 | 624 | return (0); |
324bf712 | 625 | } |
626 | ||
627 | static void | |
628 | privsep_postauth(Authctxt *authctxt) | |
629 | { | |
94d8258b | 630 | #ifdef DISABLE_FD_PASSING |
d170feb1 | 631 | if (1) { |
632 | #else | |
1853d1ef | 633 | if (authctxt->pw->pw_uid == 0 || options.use_login) { |
d170feb1 | 634 | #endif |
1853d1ef | 635 | /* File descriptor passing is broken or root login */ |
b5a28cbc | 636 | monitor_apply_keystate(pmonitor); |
1853d1ef | 637 | use_privsep = 0; |
638 | return; | |
639 | } | |
762715ce | 640 | |
1853d1ef | 641 | /* Authentication complete */ |
642 | alarm(0); | |
643 | if (startup_pipe != -1) { | |
644 | close(startup_pipe); | |
645 | startup_pipe = -1; | |
646 | } | |
647 | ||
648 | /* New socket pair */ | |
b5a28cbc | 649 | monitor_reinit(pmonitor); |
1853d1ef | 650 | |
b5a28cbc | 651 | pmonitor->m_pid = fork(); |
652 | if (pmonitor->m_pid == -1) | |
1853d1ef | 653 | fatal("fork of unprivileged child failed"); |
b5a28cbc | 654 | else if (pmonitor->m_pid != 0) { |
c457707e | 655 | debug2("User child is on pid %ld", (long)pmonitor->m_pid); |
b5a28cbc | 656 | close(pmonitor->m_recvfd); |
f143ed33 | 657 | buffer_clear(&loginmsg); |
b5a28cbc | 658 | monitor_child_postauth(pmonitor); |
1853d1ef | 659 | |
660 | /* NEVERREACHED */ | |
661 | exit(0); | |
662 | } | |
663 | ||
b5a28cbc | 664 | close(pmonitor->m_sendfd); |
1853d1ef | 665 | |
666 | /* Demote the private keys to public keys. */ | |
667 | demote_sensitive_data(); | |
668 | ||
669 | /* Drop privileges */ | |
670 | do_setusercontext(authctxt->pw); | |
671 | ||
672 | /* It is safe now to apply the key state */ | |
b5a28cbc | 673 | monitor_apply_keystate(pmonitor); |
07200973 | 674 | |
675 | /* | |
676 | * Tell the packet layer that authentication was successful, since | |
677 | * this information is not part of the key state. | |
678 | */ | |
679 | packet_set_authenticated(); | |
1853d1ef | 680 | } |
681 | ||
396c147e | 682 | static char * |
fa08c86b | 683 | list_hostkey_types(void) |
684 | { | |
3469eac4 | 685 | Buffer b; |
b6c7b7b7 | 686 | const char *p; |
687 | char *ret; | |
fa08c86b | 688 | int i; |
3469eac4 | 689 | |
690 | buffer_init(&b); | |
184eed6a | 691 | for (i = 0; i < options.num_host_key_files; i++) { |
fa08c86b | 692 | Key *key = sensitive_data.host_keys[i]; |
693 | if (key == NULL) | |
694 | continue; | |
6aacefa7 | 695 | switch (key->type) { |
fa08c86b | 696 | case KEY_RSA: |
697 | case KEY_DSA: | |
3469eac4 | 698 | if (buffer_len(&b) > 0) |
699 | buffer_append(&b, ",", 1); | |
700 | p = key_ssh_name(key); | |
701 | buffer_append(&b, p, strlen(p)); | |
fa08c86b | 702 | break; |
703 | } | |
704 | } | |
3469eac4 | 705 | buffer_append(&b, "\0", 1); |
b6c7b7b7 | 706 | ret = xstrdup(buffer_ptr(&b)); |
3469eac4 | 707 | buffer_free(&b); |
b6c7b7b7 | 708 | debug("list_hostkey_types: %s", ret); |
709 | return ret; | |
fa08c86b | 710 | } |
711 | ||
1853d1ef | 712 | Key * |
fa08c86b | 713 | get_hostkey_by_type(int type) |
714 | { | |
715 | int i; | |
e424e241 | 716 | |
184eed6a | 717 | for (i = 0; i < options.num_host_key_files; i++) { |
fa08c86b | 718 | Key *key = sensitive_data.host_keys[i]; |
719 | if (key != NULL && key->type == type) | |
720 | return key; | |
721 | } | |
722 | return NULL; | |
7368a6c8 | 723 | } |
724 | ||
1853d1ef | 725 | Key * |
726 | get_hostkey_by_index(int ind) | |
727 | { | |
728 | if (ind < 0 || ind >= options.num_host_key_files) | |
729 | return (NULL); | |
730 | return (sensitive_data.host_keys[ind]); | |
731 | } | |
732 | ||
733 | int | |
734 | get_hostkey_index(Key *key) | |
735 | { | |
736 | int i; | |
e424e241 | 737 | |
1853d1ef | 738 | for (i = 0; i < options.num_host_key_files; i++) { |
739 | if (key == sensitive_data.host_keys[i]) | |
740 | return (i); | |
741 | } | |
742 | return (-1); | |
743 | } | |
744 | ||
c345cf9d | 745 | /* |
746 | * returns 1 if connection should be dropped, 0 otherwise. | |
747 | * dropping starts at connection #max_startups_begin with a probability | |
748 | * of (max_startups_rate/100). the probability increases linearly until | |
749 | * all connections are dropped for startups > max_startups | |
750 | */ | |
396c147e | 751 | static int |
c345cf9d | 752 | drop_connection(int startups) |
753 | { | |
1c5eab6f | 754 | int p, r; |
c345cf9d | 755 | |
756 | if (startups < options.max_startups_begin) | |
757 | return 0; | |
758 | if (startups >= options.max_startups) | |
759 | return 1; | |
760 | if (options.max_startups_rate == 100) | |
761 | return 1; | |
762 | ||
763 | p = 100 - options.max_startups_rate; | |
764 | p *= startups - options.max_startups_begin; | |
1c5eab6f | 765 | p /= options.max_startups - options.max_startups_begin; |
c345cf9d | 766 | p += options.max_startups_rate; |
1c5eab6f | 767 | r = arc4random() % 100; |
c345cf9d | 768 | |
e9aec1d4 | 769 | debug("drop_connection: p %d, r %d", p, r); |
c345cf9d | 770 | return (r < p) ? 1 : 0; |
771 | } | |
772 | ||
2717fa0f | 773 | static void |
774 | usage(void) | |
775 | { | |
85ac7a84 | 776 | fprintf(stderr, "%s, %s\n", |
4526e8c2 | 777 | SSH_RELEASE, SSLeay_version(SSLEAY_VERSION)); |
65edde94 | 778 | fprintf(stderr, |
779 | "usage: sshd [-46Ddeiqt] [-b bits] [-f config_file] [-g login_grace_time]\n" | |
780 | " [-h host_key_file] [-k key_gen_time] [-o option] [-p port] [-u len]\n" | |
781 | ); | |
2717fa0f | 782 | exit(1); |
783 | } | |
784 | ||
b9a549d7 | 785 | static void |
786 | send_rexec_state(int fd, Buffer *conf) | |
787 | { | |
788 | Buffer m; | |
789 | ||
790 | debug3("%s: entering fd = %d config len %d", __func__, fd, | |
791 | buffer_len(conf)); | |
792 | ||
793 | /* | |
794 | * Protocol from reexec master to child: | |
795 | * string configuration | |
796 | * u_int ephemeral_key_follows | |
797 | * bignum e (only if ephemeral_key_follows == 1) | |
798 | * bignum n " | |
799 | * bignum d " | |
800 | * bignum iqmp " | |
801 | * bignum p " | |
802 | * bignum q " | |
803 | */ | |
804 | buffer_init(&m); | |
805 | buffer_put_cstring(&m, buffer_ptr(conf)); | |
806 | ||
f2107e97 | 807 | if (sensitive_data.server_key != NULL && |
b9a549d7 | 808 | sensitive_data.server_key->type == KEY_RSA1) { |
809 | buffer_put_int(&m, 1); | |
810 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->e); | |
811 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->n); | |
812 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->d); | |
813 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->iqmp); | |
814 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->p); | |
815 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->q); | |
816 | } else | |
817 | buffer_put_int(&m, 0); | |
818 | ||
819 | if (ssh_msg_send(fd, 0, &m) == -1) | |
820 | fatal("%s: ssh_msg_send failed", __func__); | |
821 | ||
822 | buffer_free(&m); | |
823 | ||
824 | debug3("%s: done", __func__); | |
825 | } | |
826 | ||
827 | static void | |
828 | recv_rexec_state(int fd, Buffer *conf) | |
829 | { | |
830 | Buffer m; | |
831 | char *cp; | |
832 | u_int len; | |
833 | ||
834 | debug3("%s: entering fd = %d", __func__, fd); | |
835 | ||
836 | buffer_init(&m); | |
837 | ||
838 | if (ssh_msg_recv(fd, &m) == -1) | |
839 | fatal("%s: ssh_msg_recv failed", __func__); | |
840 | if (buffer_get_char(&m) != 0) | |
841 | fatal("%s: rexec version mismatch", __func__); | |
842 | ||
843 | cp = buffer_get_string(&m, &len); | |
844 | if (conf != NULL) | |
845 | buffer_append(conf, cp, len + 1); | |
846 | xfree(cp); | |
847 | ||
848 | if (buffer_get_int(&m)) { | |
849 | if (sensitive_data.server_key != NULL) | |
850 | key_free(sensitive_data.server_key); | |
851 | sensitive_data.server_key = key_new_private(KEY_RSA1); | |
852 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->e); | |
853 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->n); | |
854 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->d); | |
855 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->iqmp); | |
856 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->p); | |
857 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->q); | |
858 | rsa_generate_additional_parameters( | |
859 | sensitive_data.server_key->rsa); | |
860 | } | |
861 | buffer_free(&m); | |
862 | ||
863 | debug3("%s: done", __func__); | |
864 | } | |
865 | ||
5260325f | 866 | /* |
867 | * Main program for the daemon. | |
868 | */ | |
8efc0c15 | 869 | int |
870 | main(int ac, char **av) | |
871 | { | |
5260325f | 872 | extern char *optarg; |
873 | extern int optind; | |
83529a6b | 874 | int opt, j, i, fdsetsz, on = 1; |
875 | int sock_in = -1, sock_out = -1, newsock = -1; | |
9da5c3c9 | 876 | pid_t pid; |
48e671d5 | 877 | socklen_t fromlen; |
48e671d5 | 878 | fd_set *fdset; |
879 | struct sockaddr_storage from; | |
5260325f | 880 | const char *remote_ip; |
881 | int remote_port; | |
5260325f | 882 | FILE *f; |
48e671d5 | 883 | struct addrinfo *ai; |
884 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
c5894280 | 885 | char *line; |
48e671d5 | 886 | int listen_sock, maxfd; |
9216f89c | 887 | int startup_p[2] = { -1 , -1 }, config_s[2] = { -1 , -1 }; |
089fbbd2 | 888 | int startups = 0; |
aeaa3d9e | 889 | Key *key; |
2362db19 | 890 | Authctxt *authctxt; |
59c97189 | 891 | int ret, key_used = 0; |
b9a549d7 | 892 | Buffer cfg; |
5260325f | 893 | |
6e879cb4 | 894 | #ifdef HAVE_SECUREWARE |
895 | (void)set_auth_parameters(ac, av); | |
896 | #endif | |
fda04d7d | 897 | __progname = ssh_get_progname(av[0]); |
264dce47 | 898 | init_rng(); |
899 | ||
d0104542 | 900 | /* Save argv. Duplicate so setproctitle emulation doesn't clobber it */ |
4d33e531 | 901 | saved_argc = ac; |
7706b4c7 | 902 | rexec_argc = ac; |
f420d2ba | 903 | saved_argv = xmalloc(sizeof(*saved_argv) * (ac + 1)); |
d0104542 | 904 | for (i = 0; i < ac; i++) |
905 | saved_argv[i] = xstrdup(av[i]); | |
f420d2ba | 906 | saved_argv[i] = NULL; |
d0104542 | 907 | |
908 | #ifndef HAVE_SETPROCTITLE | |
909 | /* Prepare for later setproctitle emulation */ | |
910 | compat_init_setproctitle(ac, av); | |
416c732d | 911 | av = saved_argv; |
d0104542 | 912 | #endif |
5260325f | 913 | |
a4c0faa2 | 914 | if (geteuid() == 0 && setgroups(0, NULL) == -1) |
915 | debug("setgroups(): %.200s", strerror(errno)); | |
916 | ||
5260325f | 917 | /* Initialize configuration options to their default values. */ |
918 | initialize_server_options(&options); | |
919 | ||
920 | /* Parse command-line arguments. */ | |
b9a549d7 | 921 | while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:dDeiqrtQR46")) != -1) { |
5260325f | 922 | switch (opt) { |
48e671d5 | 923 | case '4': |
31b41ceb | 924 | options.address_family = AF_INET; |
48e671d5 | 925 | break; |
926 | case '6': | |
31b41ceb | 927 | options.address_family = AF_INET6; |
48e671d5 | 928 | break; |
5260325f | 929 | case 'f': |
930 | config_file_name = optarg; | |
931 | break; | |
932 | case 'd': | |
e053cd2c | 933 | if (debug_flag == 0) { |
bcbf86ec | 934 | debug_flag = 1; |
935 | options.log_level = SYSLOG_LEVEL_DEBUG1; | |
e053cd2c | 936 | } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) |
bcbf86ec | 937 | options.log_level++; |
5260325f | 938 | break; |
0b6fbf03 | 939 | case 'D': |
940 | no_daemon_flag = 1; | |
941 | break; | |
ff14faf1 | 942 | case 'e': |
943 | log_stderr = 1; | |
944 | break; | |
5260325f | 945 | case 'i': |
946 | inetd_flag = 1; | |
947 | break; | |
b9a549d7 | 948 | case 'r': |
949 | rexec_flag = 0; | |
950 | break; | |
951 | case 'R': | |
952 | rexeced_flag = 1; | |
953 | inetd_flag = 1; | |
954 | break; | |
5260325f | 955 | case 'Q': |
9bd5b720 | 956 | /* ignored */ |
5260325f | 957 | break; |
958 | case 'q': | |
959 | options.log_level = SYSLOG_LEVEL_QUIET; | |
960 | break; | |
961 | case 'b': | |
962 | options.server_key_bits = atoi(optarg); | |
963 | break; | |
964 | case 'p': | |
48e671d5 | 965 | options.ports_from_cmdline = 1; |
bcbf86ec | 966 | if (options.num_ports >= MAX_PORTS) { |
967 | fprintf(stderr, "too many ports.\n"); | |
968 | exit(1); | |
969 | } | |
2d2a2c65 | 970 | options.ports[options.num_ports++] = a2port(optarg); |
971 | if (options.ports[options.num_ports-1] == 0) { | |
972 | fprintf(stderr, "Bad port number.\n"); | |
973 | exit(1); | |
974 | } | |
5260325f | 975 | break; |
976 | case 'g': | |
e2b1fb42 | 977 | if ((options.login_grace_time = convtime(optarg)) == -1) { |
978 | fprintf(stderr, "Invalid login grace time.\n"); | |
979 | exit(1); | |
980 | } | |
5260325f | 981 | break; |
982 | case 'k': | |
e2b1fb42 | 983 | if ((options.key_regeneration_time = convtime(optarg)) == -1) { |
984 | fprintf(stderr, "Invalid key regeneration interval.\n"); | |
985 | exit(1); | |
986 | } | |
5260325f | 987 | break; |
988 | case 'h': | |
fa08c86b | 989 | if (options.num_host_key_files >= MAX_HOSTKEYS) { |
990 | fprintf(stderr, "too many host keys.\n"); | |
991 | exit(1); | |
992 | } | |
993 | options.host_key_files[options.num_host_key_files++] = optarg; | |
5260325f | 994 | break; |
f87f09aa | 995 | case 't': |
996 | test_flag = 1; | |
997 | break; | |
c345cf9d | 998 | case 'u': |
999 | utmp_len = atoi(optarg); | |
67f04db1 | 1000 | if (utmp_len > MAXHOSTNAMELEN) { |
1001 | fprintf(stderr, "Invalid utmp length.\n"); | |
1002 | exit(1); | |
1003 | } | |
c345cf9d | 1004 | break; |
2717fa0f | 1005 | case 'o': |
c5894280 | 1006 | line = xstrdup(optarg); |
1007 | if (process_server_config_line(&options, line, | |
2717fa0f | 1008 | "command-line", 0) != 0) |
184eed6a | 1009 | exit(1); |
c5894280 | 1010 | xfree(line); |
2717fa0f | 1011 | break; |
5260325f | 1012 | case '?': |
1013 | default: | |
2717fa0f | 1014 | usage(); |
1015 | break; | |
5260325f | 1016 | } |
1017 | } | |
b9a549d7 | 1018 | if (rexeced_flag || inetd_flag) |
1019 | rexec_flag = 0; | |
1020 | if (rexec_flag && (av[0] == NULL || *av[0] != '/')) | |
1021 | fatal("sshd re-exec requires execution with an absolute path"); | |
1022 | if (rexeced_flag) | |
b250e837 | 1023 | closefrom(REEXEC_MIN_FREE_FD); |
1024 | else | |
1025 | closefrom(REEXEC_DEVCRYPTO_RESERVED_FD); | |
b9a549d7 | 1026 | |
1a92bd7e | 1027 | SSLeay_add_all_algorithms(); |
5260325f | 1028 | |
48e671d5 | 1029 | /* |
1030 | * Force logging to stderr until we have loaded the private host | |
1031 | * key (unless started from inetd) | |
1032 | */ | |
1fe6a48f | 1033 | log_init(__progname, |
980c9344 | 1034 | options.log_level == SYSLOG_LEVEL_NOT_SET ? |
1035 | SYSLOG_LEVEL_INFO : options.log_level, | |
1036 | options.log_facility == SYSLOG_FACILITY_NOT_SET ? | |
1037 | SYSLOG_FACILITY_AUTH : options.log_facility, | |
51efad8c | 1038 | log_stderr || !inetd_flag); |
48e671d5 | 1039 | |
351f44a0 | 1040 | /* |
1041 | * Unset KRB5CCNAME, otherwise the user's session may inherit it from | |
1042 | * root's environment | |
d1cf9a87 | 1043 | */ |
3bfd27d5 | 1044 | if (getenv("KRB5CCNAME") != NULL) |
1045 | unsetenv("KRB5CCNAME"); | |
1046 | ||
ef51930f | 1047 | #ifdef _UNICOS |
e5ba4718 | 1048 | /* Cray can define user privs drop all privs now! |
1a23ac2c | 1049 | * Not needed on PRIV_SU systems! |
1050 | */ | |
1051 | drop_cray_privs(); | |
1052 | #endif | |
1053 | ||
e339aa53 | 1054 | seed_rng(); |
1055 | ||
b9a549d7 | 1056 | sensitive_data.server_key = NULL; |
1057 | sensitive_data.ssh1_host_key = NULL; | |
1058 | sensitive_data.have_ssh1_key = 0; | |
1059 | sensitive_data.have_ssh2_key = 0; | |
1060 | ||
1061 | /* Fetch our configuration */ | |
1062 | buffer_init(&cfg); | |
1063 | if (rexeced_flag) | |
b250e837 | 1064 | recv_rexec_state(REEXEC_CONFIG_PASS_FD, &cfg); |
b9a549d7 | 1065 | else |
1066 | load_server_config(config_file_name, &cfg); | |
1067 | ||
1068 | parse_server_config(&options, | |
1069 | rexeced_flag ? "rexec" : config_file_name, &cfg); | |
1070 | ||
1071 | if (!rexec_flag) | |
1072 | buffer_free(&cfg); | |
5260325f | 1073 | |
1074 | /* Fill in default values for those options not explicitly set. */ | |
1075 | fill_default_server_options(&options); | |
1076 | ||
31b41ceb | 1077 | /* set default channel AF */ |
1078 | channel_set_af(options.address_family); | |
1079 | ||
5260325f | 1080 | /* Check that there are no remaining arguments. */ |
1081 | if (optind < ac) { | |
1082 | fprintf(stderr, "Extra argument %s.\n", av[optind]); | |
1083 | exit(1); | |
8efc0c15 | 1084 | } |
5260325f | 1085 | |
4526e8c2 | 1086 | debug("sshd version %.100s", SSH_RELEASE); |
5260325f | 1087 | |
fa08c86b | 1088 | /* load private host keys */ |
343288b8 | 1089 | sensitive_data.host_keys = xmalloc(options.num_host_key_files * |
1090 | sizeof(Key *)); | |
184eed6a | 1091 | for (i = 0; i < options.num_host_key_files; i++) |
1e3b8b07 | 1092 | sensitive_data.host_keys[i] = NULL; |
a306f2dd | 1093 | |
184eed6a | 1094 | for (i = 0; i < options.num_host_key_files; i++) { |
aeaa3d9e | 1095 | key = key_load_private(options.host_key_files[i], "", NULL); |
1096 | sensitive_data.host_keys[i] = key; | |
fa08c86b | 1097 | if (key == NULL) { |
58cfa257 | 1098 | error("Could not load host key: %s", |
1099 | options.host_key_files[i]); | |
aeaa3d9e | 1100 | sensitive_data.host_keys[i] = NULL; |
fa08c86b | 1101 | continue; |
a306f2dd | 1102 | } |
6aacefa7 | 1103 | switch (key->type) { |
fa08c86b | 1104 | case KEY_RSA1: |
1105 | sensitive_data.ssh1_host_key = key; | |
1106 | sensitive_data.have_ssh1_key = 1; | |
1107 | break; | |
1108 | case KEY_RSA: | |
1109 | case KEY_DSA: | |
1110 | sensitive_data.have_ssh2_key = 1; | |
1111 | break; | |
a306f2dd | 1112 | } |
aeaa3d9e | 1113 | debug("private host key: #%d type %d %s", i, key->type, |
1114 | key_type(key)); | |
fa08c86b | 1115 | } |
1116 | if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) { | |
bbe88b6d | 1117 | logit("Disabling protocol version 1. Could not load host key"); |
fa08c86b | 1118 | options.protocol &= ~SSH_PROTO_1; |
1119 | } | |
1120 | if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) { | |
bbe88b6d | 1121 | logit("Disabling protocol version 2. Could not load host key"); |
fa08c86b | 1122 | options.protocol &= ~SSH_PROTO_2; |
a306f2dd | 1123 | } |
6a416424 | 1124 | if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) { |
bbe88b6d | 1125 | logit("sshd: no hostkeys available -- exiting."); |
5260325f | 1126 | exit(1); |
1127 | } | |
5260325f | 1128 | |
a306f2dd | 1129 | /* Check certain values for sanity. */ |
1130 | if (options.protocol & SSH_PROTO_1) { | |
1131 | if (options.server_key_bits < 512 || | |
1132 | options.server_key_bits > 32768) { | |
1133 | fprintf(stderr, "Bad server key size.\n"); | |
1134 | exit(1); | |
1135 | } | |
1136 | /* | |
1137 | * Check that server and host key lengths differ sufficiently. This | |
1138 | * is necessary to make double encryption work with rsaref. Oh, I | |
1139 | * hate software patents. I dont know if this can go? Niels | |
1140 | */ | |
1141 | if (options.server_key_bits > | |
e424e241 | 1142 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) - |
1143 | SSH_KEY_BITS_RESERVED && options.server_key_bits < | |
1144 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + | |
1145 | SSH_KEY_BITS_RESERVED) { | |
a306f2dd | 1146 | options.server_key_bits = |
e424e241 | 1147 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + |
1148 | SSH_KEY_BITS_RESERVED; | |
a306f2dd | 1149 | debug("Forcing server key to %d bits to make it differ from host key.", |
1150 | options.server_key_bits); | |
1151 | } | |
1152 | } | |
1153 | ||
3cc54fbb | 1154 | if (use_privsep) { |
1155 | struct passwd *pw; | |
1156 | struct stat st; | |
1157 | ||
1158 | if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL) | |
1159 | fatal("Privilege separation user %s does not exist", | |
1160 | SSH_PRIVSEP_USER); | |
1161 | if ((stat(_PATH_PRIVSEP_CHROOT_DIR, &st) == -1) || | |
1162 | (S_ISDIR(st.st_mode) == 0)) | |
1163 | fatal("Missing privilege separation directory: %s", | |
1164 | _PATH_PRIVSEP_CHROOT_DIR); | |
b9b82dab | 1165 | |
1166 | #ifdef HAVE_CYGWIN | |
1167 | if (check_ntsec(_PATH_PRIVSEP_CHROOT_DIR) && | |
1168 | (st.st_uid != getuid () || | |
1169 | (st.st_mode & (S_IWGRP|S_IWOTH)) != 0)) | |
1170 | #else | |
a56313d7 | 1171 | if (st.st_uid != 0 || (st.st_mode & (S_IWGRP|S_IWOTH)) != 0) |
b9b82dab | 1172 | #endif |
5f021474 | 1173 | fatal("%s must be owned by root and not group or " |
1174 | "world-writable.", _PATH_PRIVSEP_CHROOT_DIR); | |
3cc54fbb | 1175 | } |
1176 | ||
f87f09aa | 1177 | /* Configuration looks good, so exit if in test mode. */ |
1178 | if (test_flag) | |
1179 | exit(0); | |
1180 | ||
018a5ea3 | 1181 | /* |
1182 | * Clear out any supplemental groups we may have inherited. This | |
1183 | * prevents inadvertent creation of files with bad modes (in the | |
aff51935 | 1184 | * portable version at least, it's certainly possible for PAM |
1185 | * to create a file, and we can't control the code in every | |
018a5ea3 | 1186 | * module which might be used). |
1187 | */ | |
1188 | if (setgroups(0, NULL) < 0) | |
1189 | debug("setgroups() failed: %.200s", strerror(errno)); | |
1190 | ||
b9a549d7 | 1191 | if (rexec_flag) { |
1192 | rexec_argv = xmalloc(sizeof(char *) * (rexec_argc + 2)); | |
1193 | for (i = 0; i < rexec_argc; i++) { | |
1194 | debug("rexec_argv[%d]='%s'", i, saved_argv[i]); | |
1195 | rexec_argv[i] = saved_argv[i]; | |
1196 | } | |
1197 | rexec_argv[rexec_argc] = "-R"; | |
1198 | rexec_argv[rexec_argc + 1] = NULL; | |
1199 | } | |
1200 | ||
a306f2dd | 1201 | /* Initialize the log (it is reinitialized below in case we forked). */ |
25c31d49 | 1202 | if (debug_flag && (!inetd_flag || rexeced_flag)) |
5260325f | 1203 | log_stderr = 1; |
1fe6a48f | 1204 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
5260325f | 1205 | |
a306f2dd | 1206 | /* |
1207 | * If not in debugging mode, and not started from inetd, disconnect | |
1208 | * from the controlling terminal, and fork. The original process | |
1209 | * exits. | |
1210 | */ | |
0b6fbf03 | 1211 | if (!(debug_flag || inetd_flag || no_daemon_flag)) { |
8efc0c15 | 1212 | #ifdef TIOCNOTTY |
5260325f | 1213 | int fd; |
8efc0c15 | 1214 | #endif /* TIOCNOTTY */ |
5260325f | 1215 | if (daemon(0, 0) < 0) |
1216 | fatal("daemon() failed: %.200s", strerror(errno)); | |
1217 | ||
1218 | /* Disconnect from the controlling tty. */ | |
8efc0c15 | 1219 | #ifdef TIOCNOTTY |
5ca51e19 | 1220 | fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); |
5260325f | 1221 | if (fd >= 0) { |
1222 | (void) ioctl(fd, TIOCNOTTY, NULL); | |
1223 | close(fd); | |
1224 | } | |
8efc0c15 | 1225 | #endif /* TIOCNOTTY */ |
8efc0c15 | 1226 | } |
5260325f | 1227 | /* Reinitialize the log (because of the fork above). */ |
1fe6a48f | 1228 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
5260325f | 1229 | |
5260325f | 1230 | /* Initialize the random number generator. */ |
1231 | arc4random_stir(); | |
1232 | ||
1233 | /* Chdir to the root directory so that the current disk can be | |
1234 | unmounted if desired. */ | |
1235 | chdir("/"); | |
184eed6a | 1236 | |
1d3c30db | 1237 | /* ignore SIGPIPE */ |
1238 | signal(SIGPIPE, SIG_IGN); | |
5260325f | 1239 | |
5260325f | 1240 | /* Start listening for a socket, unless started from inetd. */ |
1241 | if (inetd_flag) { | |
b9a549d7 | 1242 | int fd; |
1243 | ||
4c8722d9 | 1244 | startup_pipe = -1; |
b9a549d7 | 1245 | if (rexeced_flag) { |
b250e837 | 1246 | close(REEXEC_CONFIG_PASS_FD); |
b9a549d7 | 1247 | sock_in = sock_out = dup(STDIN_FILENO); |
1248 | if (!debug_flag) { | |
b250e837 | 1249 | startup_pipe = dup(REEXEC_STARTUP_PIPE_FD); |
1250 | close(REEXEC_STARTUP_PIPE_FD); | |
b9a549d7 | 1251 | } |
1252 | } else { | |
1253 | sock_in = dup(STDIN_FILENO); | |
1254 | sock_out = dup(STDOUT_FILENO); | |
1255 | } | |
a306f2dd | 1256 | /* |
1257 | * We intentionally do not close the descriptors 0, 1, and 2 | |
b9a549d7 | 1258 | * as our code for setting the descriptors won't work if |
a306f2dd | 1259 | * ttyfd happens to be one of those. |
1260 | */ | |
b9a549d7 | 1261 | if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { |
1262 | dup2(fd, STDIN_FILENO); | |
1263 | dup2(fd, STDOUT_FILENO); | |
1264 | if (fd > STDOUT_FILENO) | |
1265 | close(fd); | |
1266 | } | |
5260325f | 1267 | debug("inetd sockets after dupping: %d, %d", sock_in, sock_out); |
b9a549d7 | 1268 | if ((options.protocol & SSH_PROTO_1) && |
1269 | sensitive_data.server_key == NULL) | |
cb7bd922 | 1270 | generate_ephemeral_server_key(); |
5260325f | 1271 | } else { |
48e671d5 | 1272 | for (ai = options.listen_addrs; ai; ai = ai->ai_next) { |
1273 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
1274 | continue; | |
1275 | if (num_listen_socks >= MAX_LISTEN_SOCKS) | |
1276 | fatal("Too many listen sockets. " | |
1277 | "Enlarge MAX_LISTEN_SOCKS"); | |
945a9853 | 1278 | if ((ret = getnameinfo(ai->ai_addr, ai->ai_addrlen, |
48e671d5 | 1279 | ntop, sizeof(ntop), strport, sizeof(strport), |
945a9853 | 1280 | NI_NUMERICHOST|NI_NUMERICSERV)) != 0) { |
1281 | error("getnameinfo failed: %.100s", | |
1282 | (ret != EAI_SYSTEM) ? gai_strerror(ret) : | |
1283 | strerror(errno)); | |
48e671d5 | 1284 | continue; |
1285 | } | |
1286 | /* Create socket for listening. */ | |
3e131a6d | 1287 | listen_sock = socket(ai->ai_family, ai->ai_socktype, |
1288 | ai->ai_protocol); | |
48e671d5 | 1289 | if (listen_sock < 0) { |
1290 | /* kernel may not support ipv6 */ | |
1291 | verbose("socket: %.100s", strerror(errno)); | |
1292 | continue; | |
1293 | } | |
170694d7 | 1294 | if (set_nonblock(listen_sock) == -1) { |
a666e3b1 | 1295 | close(listen_sock); |
1296 | continue; | |
1297 | } | |
48e671d5 | 1298 | /* |
facfd613 | 1299 | * Set socket options. |
1300 | * Allow local port reuse in TIME_WAIT. | |
48e671d5 | 1301 | */ |
facfd613 | 1302 | if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, |
1303 | &on, sizeof(on)) == -1) | |
1304 | error("setsockopt SO_REUSEADDR: %s", strerror(errno)); | |
48e671d5 | 1305 | |
1306 | debug("Bind to port %s on %s.", strport, ntop); | |
1307 | ||
1308 | /* Bind the socket to the desired port. */ | |
32ced054 | 1309 | if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) { |
1310 | if (!ai->ai_next) | |
1311 | error("Bind to port %s on %s failed: %.200s.", | |
1312 | strport, ntop, strerror(errno)); | |
48e671d5 | 1313 | close(listen_sock); |
1314 | continue; | |
1315 | } | |
1316 | listen_socks[num_listen_socks] = listen_sock; | |
1317 | num_listen_socks++; | |
1318 | ||
1319 | /* Start listening on the port. */ | |
bbe88b6d | 1320 | logit("Server listening on %s port %s.", ntop, strport); |
fce39749 | 1321 | if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0) |
48e671d5 | 1322 | fatal("listen: %.100s", strerror(errno)); |
1323 | ||
5260325f | 1324 | } |
48e671d5 | 1325 | freeaddrinfo(options.listen_addrs); |
1326 | ||
1327 | if (!num_listen_socks) | |
1328 | fatal("Cannot bind any address."); | |
1329 | ||
3aca00a3 | 1330 | if (options.protocol & SSH_PROTO_1) |
1331 | generate_ephemeral_server_key(); | |
1332 | ||
1333 | /* | |
1334 | * Arrange to restart on SIGHUP. The handler needs | |
1335 | * listen_sock. | |
1336 | */ | |
1337 | signal(SIGHUP, sighup_handler); | |
1338 | ||
1339 | signal(SIGTERM, sigterm_handler); | |
1340 | signal(SIGQUIT, sigterm_handler); | |
1341 | ||
1342 | /* Arrange SIGCHLD to be caught. */ | |
1343 | signal(SIGCHLD, main_sigchld_handler); | |
1344 | ||
1345 | /* Write out the pid file after the sigterm handler is setup */ | |
5260325f | 1346 | if (!debug_flag) { |
aa3378df | 1347 | /* |
97fb6912 | 1348 | * Record our pid in /var/run/sshd.pid to make it |
1349 | * easier to kill the correct sshd. We don't want to | |
1350 | * do this before the bind above because the bind will | |
aa3378df | 1351 | * fail if there already is a daemon, and this will |
1352 | * overwrite any old pid in the file. | |
1353 | */ | |
3c62e7eb | 1354 | f = fopen(options.pid_file, "wb"); |
71b9ced0 | 1355 | if (f == NULL) { |
1356 | error("Couldn't create pid file \"%s\": %s", | |
1357 | options.pid_file, strerror(errno)); | |
1358 | } else { | |
c457707e | 1359 | fprintf(f, "%ld\n", (long) getpid()); |
5260325f | 1360 | fclose(f); |
1361 | } | |
8efc0c15 | 1362 | } |
5260325f | 1363 | |
48e671d5 | 1364 | /* setup fd set for listen */ |
089fbbd2 | 1365 | fdset = NULL; |
48e671d5 | 1366 | maxfd = 0; |
1367 | for (i = 0; i < num_listen_socks; i++) | |
1368 | if (listen_socks[i] > maxfd) | |
1369 | maxfd = listen_socks[i]; | |
089fbbd2 | 1370 | /* pipes connected to unauthenticated childs */ |
1371 | startup_pipes = xmalloc(options.max_startups * sizeof(int)); | |
1372 | for (i = 0; i < options.max_startups; i++) | |
1373 | startup_pipes[i] = -1; | |
48e671d5 | 1374 | |
aa3378df | 1375 | /* |
1376 | * Stay listening for connections until the system crashes or | |
1377 | * the daemon is killed with a signal. | |
1378 | */ | |
5260325f | 1379 | for (;;) { |
1380 | if (received_sighup) | |
1381 | sighup_restart(); | |
089fbbd2 | 1382 | if (fdset != NULL) |
1383 | xfree(fdset); | |
b5c334cc | 1384 | fdsetsz = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask); |
089fbbd2 | 1385 | fdset = (fd_set *)xmalloc(fdsetsz); |
48e671d5 | 1386 | memset(fdset, 0, fdsetsz); |
089fbbd2 | 1387 | |
48e671d5 | 1388 | for (i = 0; i < num_listen_socks; i++) |
1389 | FD_SET(listen_socks[i], fdset); | |
089fbbd2 | 1390 | for (i = 0; i < options.max_startups; i++) |
1391 | if (startup_pipes[i] != -1) | |
1392 | FD_SET(startup_pipes[i], fdset); | |
1393 | ||
1394 | /* Wait in select until there is a connection. */ | |
59c97189 | 1395 | ret = select(maxfd+1, fdset, NULL, NULL, NULL); |
1396 | if (ret < 0 && errno != EINTR) | |
1397 | error("select: %.100s", strerror(errno)); | |
c9130033 | 1398 | if (received_sigterm) { |
bbe88b6d | 1399 | logit("Received signal %d; terminating.", |
010f9726 | 1400 | (int) received_sigterm); |
c9130033 | 1401 | close_listen_socks(); |
1402 | unlink(options.pid_file); | |
1403 | exit(255); | |
1404 | } | |
59c97189 | 1405 | if (key_used && key_do_regen) { |
cb7bd922 | 1406 | generate_ephemeral_server_key(); |
59c97189 | 1407 | key_used = 0; |
1408 | key_do_regen = 0; | |
48e671d5 | 1409 | } |
59c97189 | 1410 | if (ret < 0) |
1411 | continue; | |
1412 | ||
089fbbd2 | 1413 | for (i = 0; i < options.max_startups; i++) |
1414 | if (startup_pipes[i] != -1 && | |
1415 | FD_ISSET(startup_pipes[i], fdset)) { | |
1416 | /* | |
1417 | * the read end of the pipe is ready | |
1418 | * if the child has closed the pipe | |
8abcdba4 | 1419 | * after successful authentication |
089fbbd2 | 1420 | * or if the child has died |
1421 | */ | |
1422 | close(startup_pipes[i]); | |
1423 | startup_pipes[i] = -1; | |
1424 | startups--; | |
1425 | } | |
48e671d5 | 1426 | for (i = 0; i < num_listen_socks; i++) { |
1427 | if (!FD_ISSET(listen_socks[i], fdset)) | |
5260325f | 1428 | continue; |
089fbbd2 | 1429 | fromlen = sizeof(from); |
1430 | newsock = accept(listen_socks[i], (struct sockaddr *)&from, | |
1431 | &fromlen); | |
1432 | if (newsock < 0) { | |
1433 | if (errno != EINTR && errno != EWOULDBLOCK) | |
1434 | error("accept: %.100s", strerror(errno)); | |
1435 | continue; | |
1436 | } | |
170694d7 | 1437 | if (unset_nonblock(newsock) == -1) { |
a666e3b1 | 1438 | close(newsock); |
1439 | continue; | |
1440 | } | |
c345cf9d | 1441 | if (drop_connection(startups) == 1) { |
1442 | debug("drop connection #%d", startups); | |
089fbbd2 | 1443 | close(newsock); |
1444 | continue; | |
1445 | } | |
1446 | if (pipe(startup_p) == -1) { | |
1447 | close(newsock); | |
1448 | continue; | |
1449 | } | |
1450 | ||
b9a549d7 | 1451 | if (rexec_flag && socketpair(AF_UNIX, |
1452 | SOCK_STREAM, 0, config_s) == -1) { | |
1453 | error("reexec socketpair: %s", | |
1454 | strerror(errno)); | |
1455 | close(newsock); | |
1456 | close(startup_p[0]); | |
1457 | close(startup_p[1]); | |
1458 | continue; | |
1459 | } | |
1460 | ||
089fbbd2 | 1461 | for (j = 0; j < options.max_startups; j++) |
1462 | if (startup_pipes[j] == -1) { | |
1463 | startup_pipes[j] = startup_p[0]; | |
1464 | if (maxfd < startup_p[0]) | |
1465 | maxfd = startup_p[0]; | |
1466 | startups++; | |
1467 | break; | |
1468 | } | |
2b87da3b | 1469 | |
aa3378df | 1470 | /* |
089fbbd2 | 1471 | * Got connection. Fork a child to handle it, unless |
1472 | * we are in debugging mode. | |
aa3378df | 1473 | */ |
089fbbd2 | 1474 | if (debug_flag) { |
aa3378df | 1475 | /* |
089fbbd2 | 1476 | * In debugging mode. Close the listening |
1477 | * socket, and start processing the | |
1478 | * connection without forking. | |
aa3378df | 1479 | */ |
089fbbd2 | 1480 | debug("Server will not fork when running in debugging mode."); |
48e671d5 | 1481 | close_listen_socks(); |
5260325f | 1482 | sock_in = newsock; |
1483 | sock_out = newsock; | |
b9a549d7 | 1484 | close(startup_p[0]); |
1485 | close(startup_p[1]); | |
5540ea9b | 1486 | startup_pipe = -1; |
3f7a7e4a | 1487 | pid = getpid(); |
b9a549d7 | 1488 | if (rexec_flag) { |
1489 | send_rexec_state(config_s[0], | |
1490 | &cfg); | |
1491 | close(config_s[0]); | |
1492 | } | |
5260325f | 1493 | break; |
089fbbd2 | 1494 | } else { |
1495 | /* | |
1496 | * Normal production daemon. Fork, and have | |
1497 | * the child process the connection. The | |
1498 | * parent continues listening. | |
1499 | */ | |
1500 | if ((pid = fork()) == 0) { | |
1501 | /* | |
1502 | * Child. Close the listening and max_startup | |
1503 | * sockets. Start using the accepted socket. | |
1504 | * Reinitialize logging (since our pid has | |
1505 | * changed). We break out of the loop to handle | |
1506 | * the connection. | |
1507 | */ | |
1508 | startup_pipe = startup_p[1]; | |
7ace8c3b | 1509 | close_startup_pipes(); |
089fbbd2 | 1510 | close_listen_socks(); |
1511 | sock_in = newsock; | |
1512 | sock_out = newsock; | |
1fe6a48f | 1513 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
9216f89c | 1514 | if (rexec_flag) |
1515 | close(config_s[0]); | |
089fbbd2 | 1516 | break; |
1517 | } | |
5260325f | 1518 | } |
5260325f | 1519 | |
089fbbd2 | 1520 | /* Parent. Stay in the loop. */ |
1521 | if (pid < 0) | |
1522 | error("fork: %.100s", strerror(errno)); | |
1523 | else | |
c457707e | 1524 | debug("Forked child %ld.", (long)pid); |
5260325f | 1525 | |
089fbbd2 | 1526 | close(startup_p[1]); |
5260325f | 1527 | |
b9a549d7 | 1528 | if (rexec_flag) { |
1529 | send_rexec_state(config_s[0], &cfg); | |
1530 | close(config_s[0]); | |
1531 | close(config_s[1]); | |
1532 | } | |
1533 | ||
089fbbd2 | 1534 | /* Mark that the key has been used (it was "given" to the child). */ |
59c97189 | 1535 | if ((options.protocol & SSH_PROTO_1) && |
1536 | key_used == 0) { | |
1537 | /* Schedule server key regeneration alarm. */ | |
f00d1f78 | 1538 | signal(SIGALRM, key_regeneration_alarm); |
59c97189 | 1539 | alarm(options.key_regeneration_time); |
1540 | key_used = 1; | |
1541 | } | |
5260325f | 1542 | |
089fbbd2 | 1543 | arc4random_stir(); |
1544 | ||
1545 | /* Close the new socket (the child is now taking care of it). */ | |
1546 | close(newsock); | |
1547 | } | |
48e671d5 | 1548 | /* child process check (or debug mode) */ |
1549 | if (num_listen_socks < 0) | |
1550 | break; | |
5260325f | 1551 | } |
1552 | } | |
8efc0c15 | 1553 | |
5260325f | 1554 | /* This is the child processing a new connection. */ |
cc120685 | 1555 | setproctitle("%s", "[accepted]"); |
5260325f | 1556 | |
8b758bd2 | 1557 | /* |
1558 | * Create a new session and process group since the 4.4BSD | |
1559 | * setlogin() affects the entire process group. We don't | |
1560 | * want the child to be able to affect the parent. | |
1561 | */ | |
1562 | #if !defined(SSHD_ACQUIRES_CTTY) | |
1563 | /* | |
1564 | * If setsid is called, on some platforms sshd will later acquire a | |
1565 | * controlling terminal which will result in "could not set | |
1566 | * controlling tty" errors. | |
1567 | */ | |
1568 | if (!debug_flag && !inetd_flag && setsid() < 0) | |
1569 | error("setsid: %.100s", strerror(errno)); | |
1570 | #endif | |
1571 | ||
b9a549d7 | 1572 | if (rexec_flag) { |
1573 | int fd; | |
1574 | ||
b250e837 | 1575 | debug("rexec start in %d out %d newsock %d pipe %d sock %d", |
1576 | sock_in, sock_out, newsock, startup_pipe, config_s[0]); | |
b9a549d7 | 1577 | dup2(newsock, STDIN_FILENO); |
1578 | dup2(STDIN_FILENO, STDOUT_FILENO); | |
1579 | if (startup_pipe == -1) | |
b250e837 | 1580 | close(REEXEC_STARTUP_PIPE_FD); |
b9a549d7 | 1581 | else |
b250e837 | 1582 | dup2(startup_pipe, REEXEC_STARTUP_PIPE_FD); |
b9a549d7 | 1583 | |
b250e837 | 1584 | dup2(config_s[1], REEXEC_CONFIG_PASS_FD); |
b9a549d7 | 1585 | close(config_s[1]); |
ad148c04 | 1586 | if (startup_pipe != -1) |
1587 | close(startup_pipe); | |
b250e837 | 1588 | |
b9a549d7 | 1589 | execv(rexec_argv[0], rexec_argv); |
1590 | ||
1591 | /* Reexec has failed, fall back and continue */ | |
1592 | error("rexec of %s failed: %s", rexec_argv[0], strerror(errno)); | |
b250e837 | 1593 | recv_rexec_state(REEXEC_CONFIG_PASS_FD, NULL); |
b9a549d7 | 1594 | log_init(__progname, options.log_level, |
1595 | options.log_facility, log_stderr); | |
1596 | ||
1597 | /* Clean up fds */ | |
b250e837 | 1598 | startup_pipe = REEXEC_STARTUP_PIPE_FD; |
b9a549d7 | 1599 | close(config_s[1]); |
b250e837 | 1600 | close(REEXEC_CONFIG_PASS_FD); |
1601 | newsock = sock_out = sock_in = dup(STDIN_FILENO); | |
b9a549d7 | 1602 | if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { |
1603 | dup2(fd, STDIN_FILENO); | |
1604 | dup2(fd, STDOUT_FILENO); | |
1605 | if (fd > STDERR_FILENO) | |
1606 | close(fd); | |
1607 | } | |
b250e837 | 1608 | debug("rexec cleanup in %d out %d newsock %d pipe %d sock %d", |
1609 | sock_in, sock_out, newsock, startup_pipe, config_s[0]); | |
b9a549d7 | 1610 | } |
1611 | ||
aa3378df | 1612 | /* |
1613 | * Disable the key regeneration alarm. We will not regenerate the | |
1614 | * key since we are no longer in a position to give it to anyone. We | |
1615 | * will not restart on SIGHUP since it no longer makes sense. | |
1616 | */ | |
5260325f | 1617 | alarm(0); |
1618 | signal(SIGALRM, SIG_DFL); | |
1619 | signal(SIGHUP, SIG_DFL); | |
1620 | signal(SIGTERM, SIG_DFL); | |
1621 | signal(SIGQUIT, SIG_DFL); | |
1622 | signal(SIGCHLD, SIG_DFL); | |
9aaf9be4 | 1623 | signal(SIGINT, SIG_DFL); |
5260325f | 1624 | |
aa3378df | 1625 | /* |
1626 | * Register our connection. This turns encryption off because we do | |
1627 | * not have a key. | |
1628 | */ | |
5260325f | 1629 | packet_set_connection(sock_in, sock_out); |
07200973 | 1630 | packet_set_server(); |
5260325f | 1631 | |
7c3bc5a2 | 1632 | /* Set SO_KEEPALIVE if requested. */ |
1633 | if (options.tcp_keep_alive && packet_connection_is_on_socket() && | |
1634 | setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, sizeof(on)) < 0) | |
1635 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); | |
1636 | ||
29798ed0 | 1637 | if ((remote_port = get_remote_port()) < 0) { |
1638 | debug("get_remote_port failed"); | |
1639 | cleanup_exit(255); | |
1640 | } | |
5260325f | 1641 | remote_ip = get_remote_ipaddr(); |
1642 | ||
6039eeef | 1643 | #ifdef SSH_AUDIT_EVENTS |
c00e4d75 | 1644 | audit_connection_from(remote_ip, remote_port); |
1645 | #endif | |
5260325f | 1646 | #ifdef LIBWRAP |
ac28afd8 | 1647 | /* Check whether logins are denied from this host. */ |
33e5359c | 1648 | if (packet_connection_is_on_socket()) { |
5260325f | 1649 | struct request_info req; |
8efc0c15 | 1650 | |
8fbc356d | 1651 | request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0); |
5260325f | 1652 | fromhost(&req); |
8efc0c15 | 1653 | |
5260325f | 1654 | if (!hosts_access(&req)) { |
ac28afd8 | 1655 | debug("Connection refused by tcp wrapper"); |
563834bb | 1656 | refuse(&req); |
ac28afd8 | 1657 | /* NOTREACHED */ |
1658 | fatal("libwrap refuse returns"); | |
5260325f | 1659 | } |
8efc0c15 | 1660 | } |
48e671d5 | 1661 | #endif /* LIBWRAP */ |
ac28afd8 | 1662 | |
5260325f | 1663 | /* Log the connection. */ |
1664 | verbose("Connection from %.500s port %d", remote_ip, remote_port); | |
8efc0c15 | 1665 | |
aa3378df | 1666 | /* |
1667 | * We don\'t want to listen forever unless the other side | |
1668 | * successfully authenticates itself. So we set up an alarm which is | |
1669 | * cleared after successful authentication. A limit of zero | |
1670 | * indicates no limit. Note that we don\'t set the alarm in debugging | |
1671 | * mode; it is just annoying to have the server exit just when you | |
1672 | * are about to discover the bug. | |
1673 | */ | |
f00d1f78 | 1674 | signal(SIGALRM, grace_alarm_handler); |
5260325f | 1675 | if (!debug_flag) |
1676 | alarm(options.login_grace_time); | |
1677 | ||
7368a6c8 | 1678 | sshd_exchange_identification(sock_in, sock_out); |
0598d99d | 1679 | |
5260325f | 1680 | packet_set_nonblocking(); |
1681 | ||
2362db19 | 1682 | /* allocate authentication context */ |
1683 | authctxt = xmalloc(sizeof(*authctxt)); | |
1684 | memset(authctxt, 0, sizeof(*authctxt)); | |
1685 | ||
1b394137 | 1686 | authctxt->loginmsg = &loginmsg; |
1687 | ||
2362db19 | 1688 | /* XXX global for cleanup, access from other modules */ |
1689 | the_authctxt = authctxt; | |
1690 | ||
022487ce | 1691 | /* prepare buffer to collect messages to display to user after login */ |
1692 | buffer_init(&loginmsg); | |
1693 | ||
324bf712 | 1694 | if (use_privsep) |
2362db19 | 1695 | if (privsep_preauth(authctxt) == 1) |
324bf712 | 1696 | goto authenticated; |
1853d1ef | 1697 | |
7b2ea3a1 | 1698 | /* perform the key exchange */ |
7b2ea3a1 | 1699 | /* authenticate user and start session */ |
e78a59f5 | 1700 | if (compat20) { |
1701 | do_ssh2_kex(); | |
2362db19 | 1702 | do_authentication2(authctxt); |
e78a59f5 | 1703 | } else { |
1704 | do_ssh1_kex(); | |
2362db19 | 1705 | do_authentication(authctxt); |
e78a59f5 | 1706 | } |
324bf712 | 1707 | /* |
1708 | * If we use privilege separation, the unprivileged child transfers | |
1709 | * the current keystate and exits | |
1710 | */ | |
1711 | if (use_privsep) { | |
b5a28cbc | 1712 | mm_send_keystate(pmonitor); |
1853d1ef | 1713 | exit(0); |
324bf712 | 1714 | } |
1853d1ef | 1715 | |
1716 | authenticated: | |
6039eeef | 1717 | #ifdef SSH_AUDIT_EVENTS |
1718 | audit_event(SSH_AUTH_SUCCESS); | |
c00e4d75 | 1719 | #endif |
1720 | ||
762715ce | 1721 | /* |
1853d1ef | 1722 | * In privilege separation, we fork another child and prepare |
1723 | * file descriptor passing. | |
1724 | */ | |
1725 | if (use_privsep) { | |
324bf712 | 1726 | privsep_postauth(authctxt); |
1727 | /* the monitor process [priv] will not return */ | |
1853d1ef | 1728 | if (!compat20) |
1729 | destroy_sensitive_data(); | |
1730 | } | |
1b34c1b3 | 1731 | |
2362db19 | 1732 | /* Start session. */ |
1b34c1b3 | 1733 | do_authenticated(authctxt); |
1734 | ||
63284fbb | 1735 | /* The connection has been terminated. */ |
1736 | verbose("Closing connection to %.100s", remote_ip); | |
8efc0c15 | 1737 | |
d94aa2ae | 1738 | #ifdef USE_PAM |
7fceb20d | 1739 | if (options.use_pam) |
1740 | finish_pam(); | |
d94aa2ae | 1741 | #endif /* USE_PAM */ |
8efc0c15 | 1742 | |
2b0c0925 | 1743 | #ifdef SSH_AUDIT_EVENTS |
1744 | PRIVSEP(audit_event(SSH_CONNECTION_CLOSE)); | |
1745 | #endif | |
1746 | ||
5260325f | 1747 | packet_close(); |
1853d1ef | 1748 | |
1749 | if (use_privsep) | |
1750 | mm_terminate(); | |
1751 | ||
5260325f | 1752 | exit(0); |
1753 | } | |
8efc0c15 | 1754 | |
4f08e98d | 1755 | /* |
1756 | * Decrypt session_key_int using our private server key and private host key | |
1757 | * (key with larger modulus first). | |
1758 | */ | |
1853d1ef | 1759 | int |
4f08e98d | 1760 | ssh1_session_key(BIGNUM *session_key_int) |
1761 | { | |
1762 | int rsafail = 0; | |
1763 | ||
1764 | if (BN_cmp(sensitive_data.server_key->rsa->n, sensitive_data.ssh1_host_key->rsa->n) > 0) { | |
1765 | /* Server key has bigger modulus. */ | |
1766 | if (BN_num_bits(sensitive_data.server_key->rsa->n) < | |
1767 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) { | |
1768 | fatal("do_connection: %s: server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d", | |
1769 | get_remote_ipaddr(), | |
1770 | BN_num_bits(sensitive_data.server_key->rsa->n), | |
1771 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), | |
1772 | SSH_KEY_BITS_RESERVED); | |
1773 | } | |
1774 | if (rsa_private_decrypt(session_key_int, session_key_int, | |
1775 | sensitive_data.server_key->rsa) <= 0) | |
1776 | rsafail++; | |
1777 | if (rsa_private_decrypt(session_key_int, session_key_int, | |
1778 | sensitive_data.ssh1_host_key->rsa) <= 0) | |
1779 | rsafail++; | |
1780 | } else { | |
1781 | /* Host key has bigger modulus (or they are equal). */ | |
1782 | if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) < | |
1783 | BN_num_bits(sensitive_data.server_key->rsa->n) + SSH_KEY_BITS_RESERVED) { | |
1784 | fatal("do_connection: %s: host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d", | |
1785 | get_remote_ipaddr(), | |
1786 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), | |
1787 | BN_num_bits(sensitive_data.server_key->rsa->n), | |
1788 | SSH_KEY_BITS_RESERVED); | |
1789 | } | |
1790 | if (rsa_private_decrypt(session_key_int, session_key_int, | |
1791 | sensitive_data.ssh1_host_key->rsa) < 0) | |
1792 | rsafail++; | |
1793 | if (rsa_private_decrypt(session_key_int, session_key_int, | |
1794 | sensitive_data.server_key->rsa) < 0) | |
1795 | rsafail++; | |
1796 | } | |
1797 | return (rsafail); | |
1798 | } | |
5260325f | 1799 | /* |
7b2ea3a1 | 1800 | * SSH1 key exchange |
5260325f | 1801 | */ |
396c147e | 1802 | static void |
1e3b8b07 | 1803 | do_ssh1_kex(void) |
8efc0c15 | 1804 | { |
5260325f | 1805 | int i, len; |
46aa2d1f | 1806 | int rsafail = 0; |
5260325f | 1807 | BIGNUM *session_key_int; |
1e3b8b07 | 1808 | u_char session_key[SSH_SESSION_KEY_LENGTH]; |
1809 | u_char cookie[8]; | |
1810 | u_int cipher_type, auth_mask, protocol_flags; | |
7fdc56c5 | 1811 | u_int32_t rnd = 0; |
5260325f | 1812 | |
aa3378df | 1813 | /* |
1814 | * Generate check bytes that the client must send back in the user | |
1815 | * packet in order for it to be accepted; this is used to defy ip | |
1816 | * spoofing attacks. Note that this only works against somebody | |
1817 | * doing IP spoofing from a remote machine; any machine on the local | |
1818 | * network can still see outgoing packets and catch the random | |
1819 | * cookie. This only affects rhosts authentication, and this is one | |
1820 | * of the reasons why it is inherently insecure. | |
1821 | */ | |
5260325f | 1822 | for (i = 0; i < 8; i++) { |
1823 | if (i % 4 == 0) | |
7fdc56c5 | 1824 | rnd = arc4random(); |
1825 | cookie[i] = rnd & 0xff; | |
1826 | rnd >>= 8; | |
5260325f | 1827 | } |
1828 | ||
aa3378df | 1829 | /* |
1830 | * Send our public key. We include in the packet 64 bits of random | |
1831 | * data that must be matched in the reply in order to prevent IP | |
1832 | * spoofing. | |
1833 | */ | |
5260325f | 1834 | packet_start(SSH_SMSG_PUBLIC_KEY); |
1835 | for (i = 0; i < 8; i++) | |
7b2ea3a1 | 1836 | packet_put_char(cookie[i]); |
5260325f | 1837 | |
1838 | /* Store our public server RSA key. */ | |
fa08c86b | 1839 | packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n)); |
1840 | packet_put_bignum(sensitive_data.server_key->rsa->e); | |
1841 | packet_put_bignum(sensitive_data.server_key->rsa->n); | |
5260325f | 1842 | |
1843 | /* Store our public host RSA key. */ | |
fa08c86b | 1844 | packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); |
1845 | packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e); | |
1846 | packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n); | |
5260325f | 1847 | |
1848 | /* Put protocol flags. */ | |
1849 | packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN); | |
1850 | ||
1851 | /* Declare which ciphers we support. */ | |
94ec8c6b | 1852 | packet_put_int(cipher_mask_ssh1(0)); |
5260325f | 1853 | |
1854 | /* Declare supported authentication types. */ | |
1855 | auth_mask = 0; | |
5260325f | 1856 | if (options.rhosts_rsa_authentication) |
1857 | auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA; | |
1858 | if (options.rsa_authentication) | |
1859 | auth_mask |= 1 << SSH_AUTH_RSA; | |
5ba55ada | 1860 | if (options.challenge_response_authentication == 1) |
5260325f | 1861 | auth_mask |= 1 << SSH_AUTH_TIS; |
5260325f | 1862 | if (options.password_authentication) |
1863 | auth_mask |= 1 << SSH_AUTH_PASSWORD; | |
1864 | packet_put_int(auth_mask); | |
1865 | ||
1866 | /* Send the packet and wait for it to be sent. */ | |
1867 | packet_send(); | |
1868 | packet_write_wait(); | |
1869 | ||
fa08c86b | 1870 | debug("Sent %d bit server key and %d bit host key.", |
1871 | BN_num_bits(sensitive_data.server_key->rsa->n), | |
1872 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); | |
5260325f | 1873 | |
1874 | /* Read clients reply (cipher type and session key). */ | |
54a5250f | 1875 | packet_read_expect(SSH_CMSG_SESSION_KEY); |
5260325f | 1876 | |
2d86a6cc | 1877 | /* Get cipher type and check whether we accept this. */ |
5260325f | 1878 | cipher_type = packet_get_char(); |
1879 | ||
94ec8c6b | 1880 | if (!(cipher_mask_ssh1(0) & (1 << cipher_type))) |
2d86a6cc | 1881 | packet_disconnect("Warning: client selects unsupported cipher."); |
1882 | ||
5260325f | 1883 | /* Get check bytes from the packet. These must match those we |
1884 | sent earlier with the public key packet. */ | |
1885 | for (i = 0; i < 8; i++) | |
7b2ea3a1 | 1886 | if (cookie[i] != packet_get_char()) |
5260325f | 1887 | packet_disconnect("IP Spoofing check bytes do not match."); |
1888 | ||
1889 | debug("Encryption type: %.200s", cipher_name(cipher_type)); | |
1890 | ||
1891 | /* Get the encrypted integer. */ | |
b775c6f2 | 1892 | if ((session_key_int = BN_new()) == NULL) |
1893 | fatal("do_ssh1_kex: BN_new failed"); | |
20b279e6 | 1894 | packet_get_bignum(session_key_int); |
5260325f | 1895 | |
5260325f | 1896 | protocol_flags = packet_get_int(); |
1897 | packet_set_protocol_flags(protocol_flags); | |
95500969 | 1898 | packet_check_eom(); |
5260325f | 1899 | |
4f08e98d | 1900 | /* Decrypt session_key_int using host/server keys */ |
1853d1ef | 1901 | rsafail = PRIVSEP(ssh1_session_key(session_key_int)); |
1902 | ||
aa3378df | 1903 | /* |
1904 | * Extract session key from the decrypted integer. The key is in the | |
1905 | * least significant 256 bits of the integer; the first byte of the | |
1906 | * key is in the highest bits. | |
1907 | */ | |
46aa2d1f | 1908 | if (!rsafail) { |
1909 | BN_mask_bits(session_key_int, sizeof(session_key) * 8); | |
1910 | len = BN_num_bytes(session_key_int); | |
2ceb8101 | 1911 | if (len < 0 || (u_int)len > sizeof(session_key)) { |
46aa2d1f | 1912 | error("do_connection: bad session key len from %s: " |
5ca51e19 | 1913 | "session_key_int %d > sizeof(session_key) %lu", |
1914 | get_remote_ipaddr(), len, (u_long)sizeof(session_key)); | |
46aa2d1f | 1915 | rsafail++; |
1916 | } else { | |
1917 | memset(session_key, 0, sizeof(session_key)); | |
1918 | BN_bn2bin(session_key_int, | |
1919 | session_key + sizeof(session_key) - len); | |
00be5382 | 1920 | |
8bbf1fa6 | 1921 | derive_ssh1_session_id( |
f2107e97 | 1922 | sensitive_data.ssh1_host_key->rsa->n, |
8bbf1fa6 | 1923 | sensitive_data.server_key->rsa->n, |
1924 | cookie, session_id); | |
00be5382 | 1925 | /* |
1926 | * Xor the first 16 bytes of the session key with the | |
1927 | * session id. | |
1928 | */ | |
1929 | for (i = 0; i < 16; i++) | |
1930 | session_key[i] ^= session_id[i]; | |
46aa2d1f | 1931 | } |
1932 | } | |
1933 | if (rsafail) { | |
00be5382 | 1934 | int bytes = BN_num_bytes(session_key_int); |
f6b1ba8f | 1935 | u_char *buf = xmalloc(bytes); |
00be5382 | 1936 | MD5_CTX md; |
1937 | ||
bbe88b6d | 1938 | logit("do_connection: generating a fake encryption key"); |
00be5382 | 1939 | BN_bn2bin(session_key_int, buf); |
1940 | MD5_Init(&md); | |
1941 | MD5_Update(&md, buf, bytes); | |
1942 | MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); | |
1943 | MD5_Final(session_key, &md); | |
1944 | MD5_Init(&md); | |
1945 | MD5_Update(&md, session_key, 16); | |
1946 | MD5_Update(&md, buf, bytes); | |
1947 | MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); | |
1948 | MD5_Final(session_key + 16, &md); | |
1949 | memset(buf, 0, bytes); | |
1950 | xfree(buf); | |
0572fe75 | 1951 | for (i = 0; i < 16; i++) |
1952 | session_id[i] = session_key[i] ^ session_key[i + 16]; | |
46aa2d1f | 1953 | } |
1853d1ef | 1954 | /* Destroy the private and public keys. No longer. */ |
63284fbb | 1955 | destroy_sensitive_data(); |
00be5382 | 1956 | |
1853d1ef | 1957 | if (use_privsep) |
1958 | mm_ssh1_session_id(session_id); | |
1959 | ||
7b2ea3a1 | 1960 | /* Destroy the decrypted integer. It is no longer needed. */ |
1961 | BN_clear_free(session_key_int); | |
1962 | ||
5260325f | 1963 | /* Set the session key. From this on all communications will be encrypted. */ |
1964 | packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type); | |
1965 | ||
1966 | /* Destroy our copy of the session key. It is no longer needed. */ | |
1967 | memset(session_key, 0, sizeof(session_key)); | |
1968 | ||
1969 | debug("Received session key; encryption turned on."); | |
1970 | ||
c242fc96 | 1971 | /* Send an acknowledgment packet. Note that this packet is sent encrypted. */ |
5260325f | 1972 | packet_start(SSH_SMSG_SUCCESS); |
1973 | packet_send(); | |
1974 | packet_write_wait(); | |
5260325f | 1975 | } |
e78a59f5 | 1976 | |
1977 | /* | |
1978 | * SSH2 key exchange: diffie-hellman-group1-sha1 | |
1979 | */ | |
396c147e | 1980 | static void |
1e3b8b07 | 1981 | do_ssh2_kex(void) |
e78a59f5 | 1982 | { |
e78a59f5 | 1983 | Kex *kex; |
e78a59f5 | 1984 | |
a8be9f80 | 1985 | if (options.ciphers != NULL) { |
6ae2364d | 1986 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
a8be9f80 | 1987 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; |
1988 | } | |
1ad64a93 | 1989 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
1990 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
1991 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
1992 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
1993 | ||
b2552997 | 1994 | if (options.macs != NULL) { |
1995 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
1996 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
1997 | } | |
07200973 | 1998 | if (options.compression == COMP_NONE) { |
636f76ca | 1999 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = |
2000 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; | |
07200973 | 2001 | } else if (options.compression == COMP_DELAYED) { |
2002 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
2003 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none,zlib@openssh.com"; | |
636f76ca | 2004 | } |
07200973 | 2005 | |
fa08c86b | 2006 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types(); |
2007 | ||
7a37c112 | 2008 | /* start key exchange */ |
d8ee838b | 2009 | kex = kex_setup(myproposal); |
98a58eda | 2010 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; |
41e5bd9a | 2011 | kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; |
98a58eda | 2012 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; |
a5c9ffdb | 2013 | kex->server = 1; |
2014 | kex->client_version_string=client_version_string; | |
2015 | kex->server_version_string=server_version_string; | |
2016 | kex->load_host_key=&get_hostkey_by_type; | |
1853d1ef | 2017 | kex->host_key_index=&get_hostkey_index; |
94ec8c6b | 2018 | |
7a37c112 | 2019 | xxx_kex = kex; |
2020 | ||
c422989b | 2021 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); |
94ec8c6b | 2022 | |
d1ac6175 | 2023 | session_id2 = kex->session_id; |
2024 | session_id2_len = kex->session_id_len; | |
2025 | ||
94ec8c6b | 2026 | #ifdef DEBUG_KEXDH |
2027 | /* send 1st encrypted/maced/compressed message */ | |
2028 | packet_start(SSH2_MSG_IGNORE); | |
2029 | packet_put_cstring("markus"); | |
2030 | packet_send(); | |
2031 | packet_write_wait(); | |
2032 | #endif | |
a5c9ffdb | 2033 | debug("KEX done"); |
e78a59f5 | 2034 | } |
2362db19 | 2035 | |
2036 | /* server specific fatal cleanup */ | |
2037 | void | |
2038 | cleanup_exit(int i) | |
2039 | { | |
2040 | if (the_authctxt) | |
2041 | do_cleanup(the_authctxt); | |
6039eeef | 2042 | #ifdef SSH_AUDIT_EVENTS |
c00e4d75 | 2043 | /* done after do_cleanup so it can cancel the PAM auth 'thread' */ |
2044 | if (!use_privsep || mm_is_monitor()) | |
6039eeef | 2045 | audit_event(SSH_CONNECTION_ABANDON); |
c00e4d75 | 2046 | #endif |
2362db19 | 2047 | _exit(i); |
2048 | } |