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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" | |
be2ca0c9 | 45 | RCSID("$OpenBSD: sshd.c,v 1.299 2004/07/17 05:31:41 dtucker 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 | |
6ae2364d | 114 | /* |
48e671d5 | 115 | * Flag indicating whether IPv4 or IPv6. This can be set on the command line. |
116 | * Default value is AF_UNSPEC means both IPv4 and IPv6. | |
117 | */ | |
118 | int IPv4or6 = AF_UNSPEC; | |
119 | ||
5260325f | 120 | /* |
121 | * Debug mode flag. This can be set on the command line. If debug | |
122 | * mode is enabled, extra debugging output will be sent to the system | |
123 | * log, the daemon will not go to background, and will exit after processing | |
124 | * the first connection. | |
125 | */ | |
8efc0c15 | 126 | int debug_flag = 0; |
127 | ||
f87f09aa | 128 | /* Flag indicating that the daemon should only test the configuration and keys. */ |
129 | int test_flag = 0; | |
130 | ||
8efc0c15 | 131 | /* Flag indicating that the daemon is being started from inetd. */ |
132 | int inetd_flag = 0; | |
133 | ||
0b6fbf03 | 134 | /* Flag indicating that sshd should not detach and become a daemon. */ |
135 | int no_daemon_flag = 0; | |
136 | ||
6a17f9c2 | 137 | /* debug goes to stderr unless inetd_flag is set */ |
138 | int log_stderr = 0; | |
139 | ||
8efc0c15 | 140 | /* Saved arguments to main(). */ |
141 | char **saved_argv; | |
4d33e531 | 142 | int saved_argc; |
8efc0c15 | 143 | |
b9a549d7 | 144 | /* re-exec */ |
145 | int rexeced_flag = 0; | |
146 | int rexec_flag = 1; | |
147 | int rexec_argc = 0; | |
148 | char **rexec_argv; | |
149 | ||
aa3378df | 150 | /* |
48e671d5 | 151 | * The sockets that the server is listening; this is used in the SIGHUP |
152 | * signal handler. | |
aa3378df | 153 | */ |
48e671d5 | 154 | #define MAX_LISTEN_SOCKS 16 |
155 | int listen_socks[MAX_LISTEN_SOCKS]; | |
156 | int num_listen_socks = 0; | |
8efc0c15 | 157 | |
aa3378df | 158 | /* |
159 | * the client's version string, passed by sshd2 in compat mode. if != NULL, | |
160 | * sshd will skip the version-number exchange | |
161 | */ | |
5260325f | 162 | char *client_version_string = NULL; |
7368a6c8 | 163 | char *server_version_string = NULL; |
8efc0c15 | 164 | |
7a37c112 | 165 | /* for rekeying XXX fixme */ |
166 | Kex *xxx_kex; | |
167 | ||
aa3378df | 168 | /* |
169 | * Any really sensitive data in the application is contained in this | |
170 | * structure. The idea is that this structure could be locked into memory so | |
171 | * that the pages do not get written into swap. However, there are some | |
172 | * problems. The private key contains BIGNUMs, and we do not (in principle) | |
173 | * have access to the internals of them, and locking just the structure is | |
174 | * not very useful. Currently, memory locking is not implemented. | |
175 | */ | |
5260325f | 176 | struct { |
cb7bd922 | 177 | Key *server_key; /* ephemeral server key */ |
fa08c86b | 178 | Key *ssh1_host_key; /* ssh1 host key */ |
179 | Key **host_keys; /* all private host keys */ | |
180 | int have_ssh1_key; | |
181 | int have_ssh2_key; | |
00be5382 | 182 | u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH]; |
8efc0c15 | 183 | } sensitive_data; |
184 | ||
aa3378df | 185 | /* |
59c97189 | 186 | * Flag indicating whether the RSA server key needs to be regenerated. |
187 | * Is set in the SIGALRM handler and cleared when the key is regenerated. | |
aa3378df | 188 | */ |
7a934d1b | 189 | static volatile sig_atomic_t key_do_regen = 0; |
8efc0c15 | 190 | |
c9130033 | 191 | /* This is set to true when a signal is received. */ |
7a934d1b | 192 | static volatile sig_atomic_t received_sighup = 0; |
193 | static volatile sig_atomic_t received_sigterm = 0; | |
8efc0c15 | 194 | |
7368a6c8 | 195 | /* session identifier, used by RSA-auth */ |
1e3b8b07 | 196 | u_char session_id[16]; |
e7c0f9d5 | 197 | |
a306f2dd | 198 | /* same for ssh2 */ |
1e3b8b07 | 199 | u_char *session_id2 = NULL; |
a27002e5 | 200 | u_int session_id2_len = 0; |
a306f2dd | 201 | |
c345cf9d | 202 | /* record remote hostname or ip */ |
1e3b8b07 | 203 | u_int utmp_len = MAXHOSTNAMELEN; |
c345cf9d | 204 | |
7ace8c3b | 205 | /* options.max_startup sized array of fd ints */ |
206 | int *startup_pipes = NULL; | |
207 | int startup_pipe; /* in child */ | |
208 | ||
1853d1ef | 209 | /* variables used for privilege separation */ |
98a58eda | 210 | int use_privsep; |
a9b33b95 | 211 | struct monitor *pmonitor = NULL; |
1853d1ef | 212 | |
bc7dfc06 | 213 | /* message to be displayed after login */ |
214 | Buffer loginmsg; | |
215 | ||
2362db19 | 216 | /* global authentication context */ |
217 | Authctxt *the_authctxt = NULL; | |
218 | ||
be2ca0c9 | 219 | /* message to be displayed after login */ |
220 | Buffer loginmsg; | |
221 | ||
7368a6c8 | 222 | /* Prototypes for various functions defined later in this file. */ |
396c147e | 223 | void destroy_sensitive_data(void); |
1853d1ef | 224 | void demote_sensitive_data(void); |
c8d54615 | 225 | |
396c147e | 226 | static void do_ssh1_kex(void); |
227 | static void do_ssh2_kex(void); | |
94ec8c6b | 228 | |
48e671d5 | 229 | /* |
230 | * Close all listening sockets | |
231 | */ | |
396c147e | 232 | static void |
48e671d5 | 233 | close_listen_socks(void) |
234 | { | |
235 | int i; | |
e424e241 | 236 | |
48e671d5 | 237 | for (i = 0; i < num_listen_socks; i++) |
238 | close(listen_socks[i]); | |
239 | num_listen_socks = -1; | |
240 | } | |
241 | ||
7ace8c3b | 242 | static void |
243 | close_startup_pipes(void) | |
244 | { | |
245 | int i; | |
e424e241 | 246 | |
7ace8c3b | 247 | if (startup_pipes) |
248 | for (i = 0; i < options.max_startups; i++) | |
249 | if (startup_pipes[i] != -1) | |
250 | close(startup_pipes[i]); | |
251 | } | |
252 | ||
5260325f | 253 | /* |
254 | * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP; | |
255 | * the effect is to reread the configuration file (and to regenerate | |
256 | * the server key). | |
257 | */ | |
396c147e | 258 | static void |
5260325f | 259 | sighup_handler(int sig) |
8efc0c15 | 260 | { |
6056eb35 | 261 | int save_errno = errno; |
262 | ||
5260325f | 263 | received_sighup = 1; |
264 | signal(SIGHUP, sighup_handler); | |
6056eb35 | 265 | errno = save_errno; |
8efc0c15 | 266 | } |
267 | ||
5260325f | 268 | /* |
269 | * Called from the main program after receiving SIGHUP. | |
270 | * Restarts the server. | |
271 | */ | |
396c147e | 272 | static void |
5ca51e19 | 273 | sighup_restart(void) |
8efc0c15 | 274 | { |
bbe88b6d | 275 | logit("Received SIGHUP; restarting."); |
48e671d5 | 276 | close_listen_socks(); |
7ace8c3b | 277 | close_startup_pipes(); |
5260325f | 278 | execv(saved_argv[0], saved_argv); |
bbe88b6d | 279 | logit("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0], |
e424e241 | 280 | strerror(errno)); |
5260325f | 281 | exit(1); |
8efc0c15 | 282 | } |
283 | ||
5260325f | 284 | /* |
285 | * Generic signal handler for terminating signals in the master daemon. | |
5260325f | 286 | */ |
396c147e | 287 | static void |
5260325f | 288 | sigterm_handler(int sig) |
8efc0c15 | 289 | { |
c9130033 | 290 | received_sigterm = sig; |
8efc0c15 | 291 | } |
292 | ||
5260325f | 293 | /* |
294 | * SIGCHLD handler. This is called whenever a child dies. This will then | |
c9130033 | 295 | * reap any zombies left by exited children. |
5260325f | 296 | */ |
396c147e | 297 | static void |
5260325f | 298 | main_sigchld_handler(int sig) |
8efc0c15 | 299 | { |
5260325f | 300 | int save_errno = errno; |
e424e241 | 301 | pid_t pid; |
5260325f | 302 | int status; |
5ad13cd7 | 303 | |
8c38e88b | 304 | while ((pid = waitpid(-1, &status, WNOHANG)) > 0 || |
305 | (pid < 0 && errno == EINTR)) | |
5260325f | 306 | ; |
5ad13cd7 | 307 | |
5260325f | 308 | signal(SIGCHLD, main_sigchld_handler); |
309 | errno = save_errno; | |
8efc0c15 | 310 | } |
311 | ||
5260325f | 312 | /* |
313 | * Signal handler for the alarm after the login grace period has expired. | |
314 | */ | |
396c147e | 315 | static void |
5260325f | 316 | grace_alarm_handler(int sig) |
8efc0c15 | 317 | { |
c9130033 | 318 | /* XXX no idea how fix this signal handler */ |
319 | ||
a9b33b95 | 320 | if (use_privsep && pmonitor != NULL && pmonitor->m_pid > 0) |
321 | kill(pmonitor->m_pid, SIGALRM); | |
322 | ||
5260325f | 323 | /* Log error and exit. */ |
26b9a3d2 | 324 | fatal("Timeout before authentication for %s", get_remote_ipaddr()); |
5260325f | 325 | } |
8efc0c15 | 326 | |
5260325f | 327 | /* |
328 | * Signal handler for the key regeneration alarm. Note that this | |
329 | * alarm only occurs in the daemon waiting for connections, and it does not | |
330 | * do anything with the private key or random state before forking. | |
331 | * Thus there should be no concurrency control/asynchronous execution | |
332 | * problems. | |
333 | */ | |
396c147e | 334 | static void |
cb7bd922 | 335 | generate_ephemeral_server_key(void) |
fa08c86b | 336 | { |
7fdc56c5 | 337 | u_int32_t rnd = 0; |
00be5382 | 338 | int i; |
339 | ||
cd332296 | 340 | verbose("Generating %s%d bit RSA key.", |
76ca7b01 | 341 | sensitive_data.server_key ? "new " : "", options.server_key_bits); |
fa08c86b | 342 | if (sensitive_data.server_key != NULL) |
343 | key_free(sensitive_data.server_key); | |
cd332296 | 344 | sensitive_data.server_key = key_generate(KEY_RSA1, |
76ca7b01 | 345 | options.server_key_bits); |
346 | verbose("RSA key generation complete."); | |
00be5382 | 347 | |
348 | for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) { | |
349 | if (i % 4 == 0) | |
7fdc56c5 | 350 | rnd = arc4random(); |
351 | sensitive_data.ssh1_cookie[i] = rnd & 0xff; | |
352 | rnd >>= 8; | |
00be5382 | 353 | } |
354 | arc4random_stir(); | |
fa08c86b | 355 | } |
f546c780 | 356 | |
396c147e | 357 | static void |
5260325f | 358 | key_regeneration_alarm(int sig) |
359 | { | |
360 | int save_errno = errno; | |
e424e241 | 361 | |
59c97189 | 362 | signal(SIGALRM, SIG_DFL); |
5260325f | 363 | errno = save_errno; |
59c97189 | 364 | key_do_regen = 1; |
5260325f | 365 | } |
8efc0c15 | 366 | |
396c147e | 367 | static void |
7368a6c8 | 368 | sshd_exchange_identification(int sock_in, int sock_out) |
369 | { | |
a8be9f80 | 370 | int i, mismatch; |
7368a6c8 | 371 | int remote_major, remote_minor; |
a8be9f80 | 372 | int major, minor; |
7368a6c8 | 373 | char *s; |
374 | char buf[256]; /* Must not be larger than remote_version. */ | |
375 | char remote_version[256]; /* Must be at least as big as buf. */ | |
376 | ||
a8be9f80 | 377 | if ((options.protocol & SSH_PROTO_1) && |
378 | (options.protocol & SSH_PROTO_2)) { | |
379 | major = PROTOCOL_MAJOR_1; | |
380 | minor = 99; | |
381 | } else if (options.protocol & SSH_PROTO_2) { | |
382 | major = PROTOCOL_MAJOR_2; | |
383 | minor = PROTOCOL_MINOR_2; | |
384 | } else { | |
385 | major = PROTOCOL_MAJOR_1; | |
386 | minor = PROTOCOL_MINOR_1; | |
387 | } | |
388 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", major, minor, SSH_VERSION); | |
7368a6c8 | 389 | server_version_string = xstrdup(buf); |
390 | ||
7b390973 | 391 | /* Send our protocol version identification. */ |
392 | if (atomicio(vwrite, sock_out, server_version_string, | |
393 | strlen(server_version_string)) | |
394 | != strlen(server_version_string)) { | |
395 | logit("Could not write ident string to %s", get_remote_ipaddr()); | |
2362db19 | 396 | cleanup_exit(255); |
7b390973 | 397 | } |
398 | ||
399 | /* Read other sides version identification. */ | |
400 | memset(buf, 0, sizeof(buf)); | |
401 | for (i = 0; i < sizeof(buf) - 1; i++) { | |
402 | if (atomicio(read, sock_in, &buf[i], 1) != 1) { | |
403 | logit("Did not receive identification string from %s", | |
404 | get_remote_ipaddr()); | |
2362db19 | 405 | cleanup_exit(255); |
7368a6c8 | 406 | } |
7b390973 | 407 | if (buf[i] == '\r') { |
408 | buf[i] = 0; | |
409 | /* Kludge for F-Secure Macintosh < 1.0.2 */ | |
410 | if (i == 12 && | |
411 | strncmp(buf, "SSH-1.5-W1.0", 12) == 0) | |
7368a6c8 | 412 | break; |
7b390973 | 413 | continue; |
414 | } | |
415 | if (buf[i] == '\n') { | |
416 | buf[i] = 0; | |
417 | break; | |
7368a6c8 | 418 | } |
7368a6c8 | 419 | } |
7b390973 | 420 | buf[sizeof(buf) - 1] = 0; |
421 | client_version_string = xstrdup(buf); | |
7368a6c8 | 422 | |
423 | /* | |
424 | * Check that the versions match. In future this might accept | |
425 | * several versions and set appropriate flags to handle them. | |
426 | */ | |
427 | if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n", | |
428 | &remote_major, &remote_minor, remote_version) != 3) { | |
6ae2364d | 429 | s = "Protocol mismatch.\n"; |
dc54438a | 430 | (void) atomicio(vwrite, sock_out, s, strlen(s)); |
7368a6c8 | 431 | close(sock_in); |
432 | close(sock_out); | |
bbe88b6d | 433 | logit("Bad protocol version identification '%.100s' from %s", |
7368a6c8 | 434 | client_version_string, get_remote_ipaddr()); |
2362db19 | 435 | cleanup_exit(255); |
7368a6c8 | 436 | } |
437 | debug("Client protocol version %d.%d; client software version %.100s", | |
184eed6a | 438 | remote_major, remote_minor, remote_version); |
7368a6c8 | 439 | |
e78a59f5 | 440 | compat_datafellows(remote_version); |
441 | ||
9a87e2ac | 442 | if (datafellows & SSH_BUG_PROBE) { |
bbe88b6d | 443 | logit("probed from %s with %s. Don't panic.", |
9a87e2ac | 444 | get_remote_ipaddr(), client_version_string); |
2362db19 | 445 | cleanup_exit(255); |
9a87e2ac | 446 | } |
447 | ||
3a1c54d4 | 448 | if (datafellows & SSH_BUG_SCANNER) { |
bbe88b6d | 449 | logit("scanned from %s with %s. Don't panic.", |
3a1c54d4 | 450 | get_remote_ipaddr(), client_version_string); |
2362db19 | 451 | cleanup_exit(255); |
3a1c54d4 | 452 | } |
453 | ||
a8be9f80 | 454 | mismatch = 0; |
6aacefa7 | 455 | switch (remote_major) { |
7368a6c8 | 456 | case 1: |
a306f2dd | 457 | if (remote_minor == 99) { |
458 | if (options.protocol & SSH_PROTO_2) | |
459 | enable_compat20(); | |
460 | else | |
461 | mismatch = 1; | |
462 | break; | |
463 | } | |
a8be9f80 | 464 | if (!(options.protocol & SSH_PROTO_1)) { |
465 | mismatch = 1; | |
466 | break; | |
467 | } | |
7368a6c8 | 468 | if (remote_minor < 3) { |
089fbbd2 | 469 | packet_disconnect("Your ssh version is too old and " |
7368a6c8 | 470 | "is no longer supported. Please install a newer version."); |
471 | } else if (remote_minor == 3) { | |
472 | /* note that this disables agent-forwarding */ | |
473 | enable_compat13(); | |
474 | } | |
a8be9f80 | 475 | break; |
e78a59f5 | 476 | case 2: |
a8be9f80 | 477 | if (options.protocol & SSH_PROTO_2) { |
e78a59f5 | 478 | enable_compat20(); |
479 | break; | |
480 | } | |
481 | /* FALLTHROUGH */ | |
6ae2364d | 482 | default: |
a8be9f80 | 483 | mismatch = 1; |
484 | break; | |
485 | } | |
486 | chop(server_version_string); | |
a8be9f80 | 487 | debug("Local version string %.200s", server_version_string); |
488 | ||
489 | if (mismatch) { | |
7368a6c8 | 490 | s = "Protocol major versions differ.\n"; |
dc54438a | 491 | (void) atomicio(vwrite, sock_out, s, strlen(s)); |
7368a6c8 | 492 | close(sock_in); |
493 | close(sock_out); | |
bbe88b6d | 494 | logit("Protocol major versions differ for %s: %.200s vs. %.200s", |
a8be9f80 | 495 | get_remote_ipaddr(), |
496 | server_version_string, client_version_string); | |
2362db19 | 497 | cleanup_exit(255); |
7368a6c8 | 498 | } |
a306f2dd | 499 | } |
500 | ||
fa08c86b | 501 | /* Destroy the host and server keys. They will no longer be needed. */ |
a306f2dd | 502 | void |
503 | destroy_sensitive_data(void) | |
504 | { | |
fa08c86b | 505 | int i; |
506 | ||
507 | if (sensitive_data.server_key) { | |
508 | key_free(sensitive_data.server_key); | |
509 | sensitive_data.server_key = NULL; | |
510 | } | |
184eed6a | 511 | for (i = 0; i < options.num_host_key_files; i++) { |
fa08c86b | 512 | if (sensitive_data.host_keys[i]) { |
513 | key_free(sensitive_data.host_keys[i]); | |
514 | sensitive_data.host_keys[i] = NULL; | |
515 | } | |
516 | } | |
517 | sensitive_data.ssh1_host_key = NULL; | |
00be5382 | 518 | memset(sensitive_data.ssh1_cookie, 0, SSH_SESSION_KEY_LENGTH); |
fa08c86b | 519 | } |
fa08c86b | 520 | |
1853d1ef | 521 | /* Demote private to public keys for network child */ |
522 | void | |
523 | demote_sensitive_data(void) | |
524 | { | |
525 | Key *tmp; | |
526 | int i; | |
527 | ||
528 | if (sensitive_data.server_key) { | |
529 | tmp = key_demote(sensitive_data.server_key); | |
530 | key_free(sensitive_data.server_key); | |
531 | sensitive_data.server_key = tmp; | |
532 | } | |
533 | ||
534 | for (i = 0; i < options.num_host_key_files; i++) { | |
535 | if (sensitive_data.host_keys[i]) { | |
536 | tmp = key_demote(sensitive_data.host_keys[i]); | |
537 | key_free(sensitive_data.host_keys[i]); | |
538 | sensitive_data.host_keys[i] = tmp; | |
539 | if (tmp->type == KEY_RSA1) | |
540 | sensitive_data.ssh1_host_key = tmp; | |
541 | } | |
542 | } | |
543 | ||
544 | /* We do not clear ssh1_host key and cookie. XXX - Okay Niels? */ | |
545 | } | |
546 | ||
51aeb639 | 547 | static void |
1853d1ef | 548 | privsep_preauth_child(void) |
549 | { | |
7fdc56c5 | 550 | u_int32_t rnd[256]; |
6ded293b | 551 | gid_t gidset[1]; |
2ea6de2b | 552 | struct passwd *pw; |
e424e241 | 553 | int i; |
1853d1ef | 554 | |
555 | /* Enable challenge-response authentication for privilege separation */ | |
556 | privsep_challenge_enable(); | |
557 | ||
558 | for (i = 0; i < 256; i++) | |
7fdc56c5 | 559 | rnd[i] = arc4random(); |
560 | RAND_seed(rnd, sizeof(rnd)); | |
1853d1ef | 561 | |
562 | /* Demote the private keys to public keys. */ | |
563 | demote_sensitive_data(); | |
564 | ||
2ea6de2b | 565 | if ((pw = getpwnam(SSH_PRIVSEP_USER)) == NULL) |
cdc4fc39 | 566 | fatal("Privilege separation user %s does not exist", |
567 | SSH_PRIVSEP_USER); | |
2ea6de2b | 568 | memset(pw->pw_passwd, 0, strlen(pw->pw_passwd)); |
569 | endpwent(); | |
570 | ||
343288b8 | 571 | /* Change our root directory */ |
1c352e97 | 572 | if (chroot(_PATH_PRIVSEP_CHROOT_DIR) == -1) |
573 | fatal("chroot(\"%s\"): %s", _PATH_PRIVSEP_CHROOT_DIR, | |
574 | strerror(errno)); | |
1853d1ef | 575 | if (chdir("/") == -1) |
edfb66cb | 576 | fatal("chdir(\"/\"): %s", strerror(errno)); |
762715ce | 577 | |
1853d1ef | 578 | /* Drop our privileges */ |
2ea6de2b | 579 | debug3("privsep user:group %u:%u", (u_int)pw->pw_uid, |
580 | (u_int)pw->pw_gid); | |
87809a1f | 581 | #if 0 |
6ff58a4b | 582 | /* XXX not ready, too heavy after chroot */ |
2ea6de2b | 583 | do_setusercontext(pw); |
87809a1f | 584 | #else |
585 | gidset[0] = pw->pw_gid; | |
87809a1f | 586 | if (setgroups(1, gidset) < 0) |
587 | fatal("setgroups: %.100s", strerror(errno)); | |
588 | permanently_set_uid(pw); | |
589 | #endif | |
1853d1ef | 590 | } |
591 | ||
2362db19 | 592 | static int |
593 | privsep_preauth(Authctxt *authctxt) | |
1853d1ef | 594 | { |
1853d1ef | 595 | int status; |
324bf712 | 596 | pid_t pid; |
1853d1ef | 597 | |
324bf712 | 598 | /* Set up unprivileged child process to deal with network data */ |
b5a28cbc | 599 | pmonitor = monitor_init(); |
324bf712 | 600 | /* Store a pointer to the kex for later rekeying */ |
b5a28cbc | 601 | pmonitor->m_pkex = &xxx_kex; |
324bf712 | 602 | |
603 | pid = fork(); | |
604 | if (pid == -1) { | |
605 | fatal("fork of unprivileged child failed"); | |
606 | } else if (pid != 0) { | |
c457707e | 607 | debug2("Network child is on pid %ld", (long)pid); |
324bf712 | 608 | |
b5a28cbc | 609 | close(pmonitor->m_recvfd); |
a9b33b95 | 610 | pmonitor->m_pid = pid; |
2362db19 | 611 | monitor_child_preauth(authctxt, pmonitor); |
b5a28cbc | 612 | close(pmonitor->m_sendfd); |
324bf712 | 613 | |
614 | /* Sync memory */ | |
b5a28cbc | 615 | monitor_sync(pmonitor); |
324bf712 | 616 | |
617 | /* Wait for the child's exit status */ | |
8c38e88b | 618 | while (waitpid(pid, &status, 0) < 0) |
619 | if (errno != EINTR) | |
620 | break; | |
2362db19 | 621 | return (1); |
324bf712 | 622 | } else { |
623 | /* child */ | |
624 | ||
b5a28cbc | 625 | close(pmonitor->m_sendfd); |
324bf712 | 626 | |
627 | /* Demote the child */ | |
628 | if (getuid() == 0 || geteuid() == 0) | |
629 | privsep_preauth_child(); | |
47c36e5b | 630 | setproctitle("%s", "[net]"); |
324bf712 | 631 | } |
2362db19 | 632 | return (0); |
324bf712 | 633 | } |
634 | ||
635 | static void | |
636 | privsep_postauth(Authctxt *authctxt) | |
637 | { | |
94d8258b | 638 | #ifdef DISABLE_FD_PASSING |
d170feb1 | 639 | if (1) { |
640 | #else | |
1853d1ef | 641 | if (authctxt->pw->pw_uid == 0 || options.use_login) { |
d170feb1 | 642 | #endif |
1853d1ef | 643 | /* File descriptor passing is broken or root login */ |
b5a28cbc | 644 | monitor_apply_keystate(pmonitor); |
1853d1ef | 645 | use_privsep = 0; |
646 | return; | |
647 | } | |
762715ce | 648 | |
1853d1ef | 649 | /* Authentication complete */ |
650 | alarm(0); | |
651 | if (startup_pipe != -1) { | |
652 | close(startup_pipe); | |
653 | startup_pipe = -1; | |
654 | } | |
655 | ||
656 | /* New socket pair */ | |
b5a28cbc | 657 | monitor_reinit(pmonitor); |
1853d1ef | 658 | |
b5a28cbc | 659 | pmonitor->m_pid = fork(); |
660 | if (pmonitor->m_pid == -1) | |
1853d1ef | 661 | fatal("fork of unprivileged child failed"); |
b5a28cbc | 662 | else if (pmonitor->m_pid != 0) { |
c457707e | 663 | debug2("User child is on pid %ld", (long)pmonitor->m_pid); |
b5a28cbc | 664 | close(pmonitor->m_recvfd); |
665 | monitor_child_postauth(pmonitor); | |
1853d1ef | 666 | |
667 | /* NEVERREACHED */ | |
668 | exit(0); | |
669 | } | |
670 | ||
b5a28cbc | 671 | close(pmonitor->m_sendfd); |
1853d1ef | 672 | |
673 | /* Demote the private keys to public keys. */ | |
674 | demote_sensitive_data(); | |
675 | ||
676 | /* Drop privileges */ | |
677 | do_setusercontext(authctxt->pw); | |
678 | ||
679 | /* It is safe now to apply the key state */ | |
b5a28cbc | 680 | monitor_apply_keystate(pmonitor); |
1853d1ef | 681 | } |
682 | ||
396c147e | 683 | static char * |
fa08c86b | 684 | list_hostkey_types(void) |
685 | { | |
3469eac4 | 686 | Buffer b; |
b6c7b7b7 | 687 | const char *p; |
688 | char *ret; | |
fa08c86b | 689 | int i; |
3469eac4 | 690 | |
691 | buffer_init(&b); | |
184eed6a | 692 | for (i = 0; i < options.num_host_key_files; i++) { |
fa08c86b | 693 | Key *key = sensitive_data.host_keys[i]; |
694 | if (key == NULL) | |
695 | continue; | |
6aacefa7 | 696 | switch (key->type) { |
fa08c86b | 697 | case KEY_RSA: |
698 | case KEY_DSA: | |
3469eac4 | 699 | if (buffer_len(&b) > 0) |
700 | buffer_append(&b, ",", 1); | |
701 | p = key_ssh_name(key); | |
702 | buffer_append(&b, p, strlen(p)); | |
fa08c86b | 703 | break; |
704 | } | |
705 | } | |
3469eac4 | 706 | buffer_append(&b, "\0", 1); |
b6c7b7b7 | 707 | ret = xstrdup(buffer_ptr(&b)); |
3469eac4 | 708 | buffer_free(&b); |
b6c7b7b7 | 709 | debug("list_hostkey_types: %s", ret); |
710 | return ret; | |
fa08c86b | 711 | } |
712 | ||
1853d1ef | 713 | Key * |
fa08c86b | 714 | get_hostkey_by_type(int type) |
715 | { | |
716 | int i; | |
e424e241 | 717 | |
184eed6a | 718 | for (i = 0; i < options.num_host_key_files; i++) { |
fa08c86b | 719 | Key *key = sensitive_data.host_keys[i]; |
720 | if (key != NULL && key->type == type) | |
721 | return key; | |
722 | } | |
723 | return NULL; | |
7368a6c8 | 724 | } |
725 | ||
1853d1ef | 726 | Key * |
727 | get_hostkey_by_index(int ind) | |
728 | { | |
729 | if (ind < 0 || ind >= options.num_host_key_files) | |
730 | return (NULL); | |
731 | return (sensitive_data.host_keys[ind]); | |
732 | } | |
733 | ||
734 | int | |
735 | get_hostkey_index(Key *key) | |
736 | { | |
737 | int i; | |
e424e241 | 738 | |
1853d1ef | 739 | for (i = 0; i < options.num_host_key_files; i++) { |
740 | if (key == sensitive_data.host_keys[i]) | |
741 | return (i); | |
742 | } | |
743 | return (-1); | |
744 | } | |
745 | ||
c345cf9d | 746 | /* |
747 | * returns 1 if connection should be dropped, 0 otherwise. | |
748 | * dropping starts at connection #max_startups_begin with a probability | |
749 | * of (max_startups_rate/100). the probability increases linearly until | |
750 | * all connections are dropped for startups > max_startups | |
751 | */ | |
396c147e | 752 | static int |
c345cf9d | 753 | drop_connection(int startups) |
754 | { | |
755 | double p, r; | |
756 | ||
757 | if (startups < options.max_startups_begin) | |
758 | return 0; | |
759 | if (startups >= options.max_startups) | |
760 | return 1; | |
761 | if (options.max_startups_rate == 100) | |
762 | return 1; | |
763 | ||
764 | p = 100 - options.max_startups_rate; | |
765 | p *= startups - options.max_startups_begin; | |
766 | p /= (double) (options.max_startups - options.max_startups_begin); | |
767 | p += options.max_startups_rate; | |
768 | p /= 100.0; | |
769 | r = arc4random() / (double) UINT_MAX; | |
770 | ||
771 | debug("drop_connection: p %g, r %g", p, r); | |
772 | return (r < p) ? 1 : 0; | |
773 | } | |
774 | ||
2717fa0f | 775 | static void |
776 | usage(void) | |
777 | { | |
85ac7a84 | 778 | fprintf(stderr, "%s, %s\n", |
418ae4b4 | 779 | SSH_VERSION, SSLeay_version(SSLEAY_VERSION)); |
65edde94 | 780 | fprintf(stderr, |
781 | "usage: sshd [-46Ddeiqt] [-b bits] [-f config_file] [-g login_grace_time]\n" | |
782 | " [-h host_key_file] [-k key_gen_time] [-o option] [-p port] [-u len]\n" | |
783 | ); | |
2717fa0f | 784 | exit(1); |
785 | } | |
786 | ||
b9a549d7 | 787 | static void |
788 | send_rexec_state(int fd, Buffer *conf) | |
789 | { | |
790 | Buffer m; | |
791 | ||
792 | debug3("%s: entering fd = %d config len %d", __func__, fd, | |
793 | buffer_len(conf)); | |
794 | ||
795 | /* | |
796 | * Protocol from reexec master to child: | |
797 | * string configuration | |
798 | * u_int ephemeral_key_follows | |
799 | * bignum e (only if ephemeral_key_follows == 1) | |
800 | * bignum n " | |
801 | * bignum d " | |
802 | * bignum iqmp " | |
803 | * bignum p " | |
804 | * bignum q " | |
805 | */ | |
806 | buffer_init(&m); | |
807 | buffer_put_cstring(&m, buffer_ptr(conf)); | |
808 | ||
f2107e97 | 809 | if (sensitive_data.server_key != NULL && |
b9a549d7 | 810 | sensitive_data.server_key->type == KEY_RSA1) { |
811 | buffer_put_int(&m, 1); | |
812 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->e); | |
813 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->n); | |
814 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->d); | |
815 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->iqmp); | |
816 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->p); | |
817 | buffer_put_bignum(&m, sensitive_data.server_key->rsa->q); | |
818 | } else | |
819 | buffer_put_int(&m, 0); | |
820 | ||
821 | if (ssh_msg_send(fd, 0, &m) == -1) | |
822 | fatal("%s: ssh_msg_send failed", __func__); | |
823 | ||
824 | buffer_free(&m); | |
825 | ||
826 | debug3("%s: done", __func__); | |
827 | } | |
828 | ||
829 | static void | |
830 | recv_rexec_state(int fd, Buffer *conf) | |
831 | { | |
832 | Buffer m; | |
833 | char *cp; | |
834 | u_int len; | |
835 | ||
836 | debug3("%s: entering fd = %d", __func__, fd); | |
837 | ||
838 | buffer_init(&m); | |
839 | ||
840 | if (ssh_msg_recv(fd, &m) == -1) | |
841 | fatal("%s: ssh_msg_recv failed", __func__); | |
842 | if (buffer_get_char(&m) != 0) | |
843 | fatal("%s: rexec version mismatch", __func__); | |
844 | ||
845 | cp = buffer_get_string(&m, &len); | |
846 | if (conf != NULL) | |
847 | buffer_append(conf, cp, len + 1); | |
848 | xfree(cp); | |
849 | ||
850 | if (buffer_get_int(&m)) { | |
851 | if (sensitive_data.server_key != NULL) | |
852 | key_free(sensitive_data.server_key); | |
853 | sensitive_data.server_key = key_new_private(KEY_RSA1); | |
854 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->e); | |
855 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->n); | |
856 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->d); | |
857 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->iqmp); | |
858 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->p); | |
859 | buffer_get_bignum(&m, sensitive_data.server_key->rsa->q); | |
860 | rsa_generate_additional_parameters( | |
861 | sensitive_data.server_key->rsa); | |
862 | } | |
863 | buffer_free(&m); | |
864 | ||
865 | debug3("%s: done", __func__); | |
866 | } | |
867 | ||
5260325f | 868 | /* |
869 | * Main program for the daemon. | |
870 | */ | |
8efc0c15 | 871 | int |
872 | main(int ac, char **av) | |
873 | { | |
5260325f | 874 | extern char *optarg; |
875 | extern int optind; | |
83529a6b | 876 | int opt, j, i, fdsetsz, on = 1; |
877 | int sock_in = -1, sock_out = -1, newsock = -1; | |
9da5c3c9 | 878 | pid_t pid; |
48e671d5 | 879 | socklen_t fromlen; |
48e671d5 | 880 | fd_set *fdset; |
881 | struct sockaddr_storage from; | |
5260325f | 882 | const char *remote_ip; |
883 | int remote_port; | |
5260325f | 884 | FILE *f; |
48e671d5 | 885 | struct addrinfo *ai; |
886 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
c5894280 | 887 | char *line; |
48e671d5 | 888 | int listen_sock, maxfd; |
b9a549d7 | 889 | int startup_p[2], config_s[2]; |
089fbbd2 | 890 | int startups = 0; |
aeaa3d9e | 891 | Key *key; |
2362db19 | 892 | Authctxt *authctxt; |
59c97189 | 893 | int ret, key_used = 0; |
b9a549d7 | 894 | Buffer cfg; |
5260325f | 895 | |
6e879cb4 | 896 | #ifdef HAVE_SECUREWARE |
897 | (void)set_auth_parameters(ac, av); | |
898 | #endif | |
fda04d7d | 899 | __progname = ssh_get_progname(av[0]); |
264dce47 | 900 | init_rng(); |
901 | ||
d0104542 | 902 | /* Save argv. Duplicate so setproctitle emulation doesn't clobber it */ |
4d33e531 | 903 | saved_argc = ac; |
7706b4c7 | 904 | rexec_argc = ac; |
f420d2ba | 905 | saved_argv = xmalloc(sizeof(*saved_argv) * (ac + 1)); |
d0104542 | 906 | for (i = 0; i < ac; i++) |
907 | saved_argv[i] = xstrdup(av[i]); | |
f420d2ba | 908 | saved_argv[i] = NULL; |
d0104542 | 909 | |
910 | #ifndef HAVE_SETPROCTITLE | |
911 | /* Prepare for later setproctitle emulation */ | |
912 | compat_init_setproctitle(ac, av); | |
416c732d | 913 | av = saved_argv; |
d0104542 | 914 | #endif |
5260325f | 915 | |
a4c0faa2 | 916 | if (geteuid() == 0 && setgroups(0, NULL) == -1) |
917 | debug("setgroups(): %.200s", strerror(errno)); | |
918 | ||
5260325f | 919 | /* Initialize configuration options to their default values. */ |
920 | initialize_server_options(&options); | |
921 | ||
922 | /* Parse command-line arguments. */ | |
b9a549d7 | 923 | while ((opt = getopt(ac, av, "f:p:b:k:h:g:u:o:dDeiqrtQR46")) != -1) { |
5260325f | 924 | switch (opt) { |
48e671d5 | 925 | case '4': |
926 | IPv4or6 = AF_INET; | |
927 | break; | |
928 | case '6': | |
929 | IPv4or6 = AF_INET6; | |
930 | break; | |
5260325f | 931 | case 'f': |
932 | config_file_name = optarg; | |
933 | break; | |
934 | case 'd': | |
e053cd2c | 935 | if (debug_flag == 0) { |
bcbf86ec | 936 | debug_flag = 1; |
937 | options.log_level = SYSLOG_LEVEL_DEBUG1; | |
e053cd2c | 938 | } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) |
bcbf86ec | 939 | options.log_level++; |
5260325f | 940 | break; |
0b6fbf03 | 941 | case 'D': |
942 | no_daemon_flag = 1; | |
943 | break; | |
ff14faf1 | 944 | case 'e': |
945 | log_stderr = 1; | |
946 | break; | |
5260325f | 947 | case 'i': |
948 | inetd_flag = 1; | |
949 | break; | |
b9a549d7 | 950 | case 'r': |
951 | rexec_flag = 0; | |
952 | break; | |
953 | case 'R': | |
954 | rexeced_flag = 1; | |
955 | inetd_flag = 1; | |
956 | break; | |
5260325f | 957 | case 'Q': |
9bd5b720 | 958 | /* ignored */ |
5260325f | 959 | break; |
960 | case 'q': | |
961 | options.log_level = SYSLOG_LEVEL_QUIET; | |
962 | break; | |
963 | case 'b': | |
964 | options.server_key_bits = atoi(optarg); | |
965 | break; | |
966 | case 'p': | |
48e671d5 | 967 | options.ports_from_cmdline = 1; |
bcbf86ec | 968 | if (options.num_ports >= MAX_PORTS) { |
969 | fprintf(stderr, "too many ports.\n"); | |
970 | exit(1); | |
971 | } | |
2d2a2c65 | 972 | options.ports[options.num_ports++] = a2port(optarg); |
973 | if (options.ports[options.num_ports-1] == 0) { | |
974 | fprintf(stderr, "Bad port number.\n"); | |
975 | exit(1); | |
976 | } | |
5260325f | 977 | break; |
978 | case 'g': | |
e2b1fb42 | 979 | if ((options.login_grace_time = convtime(optarg)) == -1) { |
980 | fprintf(stderr, "Invalid login grace time.\n"); | |
981 | exit(1); | |
982 | } | |
5260325f | 983 | break; |
984 | case 'k': | |
e2b1fb42 | 985 | if ((options.key_regeneration_time = convtime(optarg)) == -1) { |
986 | fprintf(stderr, "Invalid key regeneration interval.\n"); | |
987 | exit(1); | |
988 | } | |
5260325f | 989 | break; |
990 | case 'h': | |
fa08c86b | 991 | if (options.num_host_key_files >= MAX_HOSTKEYS) { |
992 | fprintf(stderr, "too many host keys.\n"); | |
993 | exit(1); | |
994 | } | |
995 | options.host_key_files[options.num_host_key_files++] = optarg; | |
5260325f | 996 | break; |
f87f09aa | 997 | case 't': |
998 | test_flag = 1; | |
999 | break; | |
c345cf9d | 1000 | case 'u': |
1001 | utmp_len = atoi(optarg); | |
67f04db1 | 1002 | if (utmp_len > MAXHOSTNAMELEN) { |
1003 | fprintf(stderr, "Invalid utmp length.\n"); | |
1004 | exit(1); | |
1005 | } | |
c345cf9d | 1006 | break; |
2717fa0f | 1007 | case 'o': |
c5894280 | 1008 | line = xstrdup(optarg); |
1009 | if (process_server_config_line(&options, line, | |
2717fa0f | 1010 | "command-line", 0) != 0) |
184eed6a | 1011 | exit(1); |
c5894280 | 1012 | xfree(line); |
2717fa0f | 1013 | break; |
5260325f | 1014 | case '?': |
1015 | default: | |
2717fa0f | 1016 | usage(); |
1017 | break; | |
5260325f | 1018 | } |
1019 | } | |
b9a549d7 | 1020 | if (rexeced_flag || inetd_flag) |
1021 | rexec_flag = 0; | |
1022 | if (rexec_flag && (av[0] == NULL || *av[0] != '/')) | |
1023 | fatal("sshd re-exec requires execution with an absolute path"); | |
1024 | if (rexeced_flag) | |
b250e837 | 1025 | closefrom(REEXEC_MIN_FREE_FD); |
1026 | else | |
1027 | closefrom(REEXEC_DEVCRYPTO_RESERVED_FD); | |
b9a549d7 | 1028 | |
1a92bd7e | 1029 | SSLeay_add_all_algorithms(); |
5e4a7219 | 1030 | channel_set_af(IPv4or6); |
5260325f | 1031 | |
48e671d5 | 1032 | /* |
1033 | * Force logging to stderr until we have loaded the private host | |
1034 | * key (unless started from inetd) | |
1035 | */ | |
1fe6a48f | 1036 | log_init(__progname, |
980c9344 | 1037 | options.log_level == SYSLOG_LEVEL_NOT_SET ? |
1038 | SYSLOG_LEVEL_INFO : options.log_level, | |
1039 | options.log_facility == SYSLOG_FACILITY_NOT_SET ? | |
1040 | SYSLOG_FACILITY_AUTH : options.log_facility, | |
51efad8c | 1041 | log_stderr || !inetd_flag); |
48e671d5 | 1042 | |
351f44a0 | 1043 | #ifdef _AIX |
1044 | /* | |
1045 | * Unset KRB5CCNAME, otherwise the user's session may inherit it from | |
1046 | * root's environment | |
1047 | */ | |
1048 | unsetenv("KRB5CCNAME"); | |
1049 | #endif /* _AIX */ | |
ef51930f | 1050 | #ifdef _UNICOS |
e5ba4718 | 1051 | /* Cray can define user privs drop all privs now! |
1a23ac2c | 1052 | * Not needed on PRIV_SU systems! |
1053 | */ | |
1054 | drop_cray_privs(); | |
1055 | #endif | |
1056 | ||
e339aa53 | 1057 | seed_rng(); |
1058 | ||
b9a549d7 | 1059 | sensitive_data.server_key = NULL; |
1060 | sensitive_data.ssh1_host_key = NULL; | |
1061 | sensitive_data.have_ssh1_key = 0; | |
1062 | sensitive_data.have_ssh2_key = 0; | |
1063 | ||
1064 | /* Fetch our configuration */ | |
1065 | buffer_init(&cfg); | |
1066 | if (rexeced_flag) | |
b250e837 | 1067 | recv_rexec_state(REEXEC_CONFIG_PASS_FD, &cfg); |
b9a549d7 | 1068 | else |
1069 | load_server_config(config_file_name, &cfg); | |
1070 | ||
1071 | parse_server_config(&options, | |
1072 | rexeced_flag ? "rexec" : config_file_name, &cfg); | |
1073 | ||
1074 | if (!rexec_flag) | |
1075 | buffer_free(&cfg); | |
5260325f | 1076 | |
1077 | /* Fill in default values for those options not explicitly set. */ | |
1078 | fill_default_server_options(&options); | |
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 | |
1086 | debug("sshd version %.100s", SSH_VERSION); | |
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). */ |
5260325f | 1202 | if (debug_flag && !inetd_flag) |
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"); | |
1278 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, | |
1279 | ntop, sizeof(ntop), strport, sizeof(strport), | |
1280 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
1281 | error("getnameinfo failed"); | |
1282 | continue; | |
1283 | } | |
1284 | /* Create socket for listening. */ | |
3e131a6d | 1285 | listen_sock = socket(ai->ai_family, ai->ai_socktype, |
1286 | ai->ai_protocol); | |
48e671d5 | 1287 | if (listen_sock < 0) { |
1288 | /* kernel may not support ipv6 */ | |
1289 | verbose("socket: %.100s", strerror(errno)); | |
1290 | continue; | |
1291 | } | |
170694d7 | 1292 | if (set_nonblock(listen_sock) == -1) { |
a666e3b1 | 1293 | close(listen_sock); |
1294 | continue; | |
1295 | } | |
48e671d5 | 1296 | /* |
facfd613 | 1297 | * Set socket options. |
1298 | * Allow local port reuse in TIME_WAIT. | |
48e671d5 | 1299 | */ |
facfd613 | 1300 | if (setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, |
1301 | &on, sizeof(on)) == -1) | |
1302 | error("setsockopt SO_REUSEADDR: %s", strerror(errno)); | |
48e671d5 | 1303 | |
1304 | debug("Bind to port %s on %s.", strport, ntop); | |
1305 | ||
1306 | /* Bind the socket to the desired port. */ | |
32ced054 | 1307 | if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) { |
1308 | if (!ai->ai_next) | |
1309 | error("Bind to port %s on %s failed: %.200s.", | |
1310 | strport, ntop, strerror(errno)); | |
48e671d5 | 1311 | close(listen_sock); |
1312 | continue; | |
1313 | } | |
1314 | listen_socks[num_listen_socks] = listen_sock; | |
1315 | num_listen_socks++; | |
1316 | ||
1317 | /* Start listening on the port. */ | |
bbe88b6d | 1318 | logit("Server listening on %s port %s.", ntop, strport); |
fce39749 | 1319 | if (listen(listen_sock, SSH_LISTEN_BACKLOG) < 0) |
48e671d5 | 1320 | fatal("listen: %.100s", strerror(errno)); |
1321 | ||
5260325f | 1322 | } |
48e671d5 | 1323 | freeaddrinfo(options.listen_addrs); |
1324 | ||
1325 | if (!num_listen_socks) | |
1326 | fatal("Cannot bind any address."); | |
1327 | ||
3aca00a3 | 1328 | if (options.protocol & SSH_PROTO_1) |
1329 | generate_ephemeral_server_key(); | |
1330 | ||
1331 | /* | |
1332 | * Arrange to restart on SIGHUP. The handler needs | |
1333 | * listen_sock. | |
1334 | */ | |
1335 | signal(SIGHUP, sighup_handler); | |
1336 | ||
1337 | signal(SIGTERM, sigterm_handler); | |
1338 | signal(SIGQUIT, sigterm_handler); | |
1339 | ||
1340 | /* Arrange SIGCHLD to be caught. */ | |
1341 | signal(SIGCHLD, main_sigchld_handler); | |
1342 | ||
1343 | /* Write out the pid file after the sigterm handler is setup */ | |
5260325f | 1344 | if (!debug_flag) { |
aa3378df | 1345 | /* |
97fb6912 | 1346 | * Record our pid in /var/run/sshd.pid to make it |
1347 | * easier to kill the correct sshd. We don't want to | |
1348 | * do this before the bind above because the bind will | |
aa3378df | 1349 | * fail if there already is a daemon, and this will |
1350 | * overwrite any old pid in the file. | |
1351 | */ | |
3c62e7eb | 1352 | f = fopen(options.pid_file, "wb"); |
71b9ced0 | 1353 | if (f == NULL) { |
1354 | error("Couldn't create pid file \"%s\": %s", | |
1355 | options.pid_file, strerror(errno)); | |
1356 | } else { | |
c457707e | 1357 | fprintf(f, "%ld\n", (long) getpid()); |
5260325f | 1358 | fclose(f); |
1359 | } | |
8efc0c15 | 1360 | } |
5260325f | 1361 | |
48e671d5 | 1362 | /* setup fd set for listen */ |
089fbbd2 | 1363 | fdset = NULL; |
48e671d5 | 1364 | maxfd = 0; |
1365 | for (i = 0; i < num_listen_socks; i++) | |
1366 | if (listen_socks[i] > maxfd) | |
1367 | maxfd = listen_socks[i]; | |
089fbbd2 | 1368 | /* pipes connected to unauthenticated childs */ |
1369 | startup_pipes = xmalloc(options.max_startups * sizeof(int)); | |
1370 | for (i = 0; i < options.max_startups; i++) | |
1371 | startup_pipes[i] = -1; | |
48e671d5 | 1372 | |
aa3378df | 1373 | /* |
1374 | * Stay listening for connections until the system crashes or | |
1375 | * the daemon is killed with a signal. | |
1376 | */ | |
5260325f | 1377 | for (;;) { |
1378 | if (received_sighup) | |
1379 | sighup_restart(); | |
089fbbd2 | 1380 | if (fdset != NULL) |
1381 | xfree(fdset); | |
b5c334cc | 1382 | fdsetsz = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask); |
089fbbd2 | 1383 | fdset = (fd_set *)xmalloc(fdsetsz); |
48e671d5 | 1384 | memset(fdset, 0, fdsetsz); |
089fbbd2 | 1385 | |
48e671d5 | 1386 | for (i = 0; i < num_listen_socks; i++) |
1387 | FD_SET(listen_socks[i], fdset); | |
089fbbd2 | 1388 | for (i = 0; i < options.max_startups; i++) |
1389 | if (startup_pipes[i] != -1) | |
1390 | FD_SET(startup_pipes[i], fdset); | |
1391 | ||
1392 | /* Wait in select until there is a connection. */ | |
59c97189 | 1393 | ret = select(maxfd+1, fdset, NULL, NULL, NULL); |
1394 | if (ret < 0 && errno != EINTR) | |
1395 | error("select: %.100s", strerror(errno)); | |
c9130033 | 1396 | if (received_sigterm) { |
bbe88b6d | 1397 | logit("Received signal %d; terminating.", |
010f9726 | 1398 | (int) received_sigterm); |
c9130033 | 1399 | close_listen_socks(); |
1400 | unlink(options.pid_file); | |
1401 | exit(255); | |
1402 | } | |
59c97189 | 1403 | if (key_used && key_do_regen) { |
cb7bd922 | 1404 | generate_ephemeral_server_key(); |
59c97189 | 1405 | key_used = 0; |
1406 | key_do_regen = 0; | |
48e671d5 | 1407 | } |
59c97189 | 1408 | if (ret < 0) |
1409 | continue; | |
1410 | ||
089fbbd2 | 1411 | for (i = 0; i < options.max_startups; i++) |
1412 | if (startup_pipes[i] != -1 && | |
1413 | FD_ISSET(startup_pipes[i], fdset)) { | |
1414 | /* | |
1415 | * the read end of the pipe is ready | |
1416 | * if the child has closed the pipe | |
8abcdba4 | 1417 | * after successful authentication |
089fbbd2 | 1418 | * or if the child has died |
1419 | */ | |
1420 | close(startup_pipes[i]); | |
1421 | startup_pipes[i] = -1; | |
1422 | startups--; | |
1423 | } | |
48e671d5 | 1424 | for (i = 0; i < num_listen_socks; i++) { |
1425 | if (!FD_ISSET(listen_socks[i], fdset)) | |
5260325f | 1426 | continue; |
089fbbd2 | 1427 | fromlen = sizeof(from); |
1428 | newsock = accept(listen_socks[i], (struct sockaddr *)&from, | |
1429 | &fromlen); | |
1430 | if (newsock < 0) { | |
1431 | if (errno != EINTR && errno != EWOULDBLOCK) | |
1432 | error("accept: %.100s", strerror(errno)); | |
1433 | continue; | |
1434 | } | |
170694d7 | 1435 | if (unset_nonblock(newsock) == -1) { |
a666e3b1 | 1436 | close(newsock); |
1437 | continue; | |
1438 | } | |
c345cf9d | 1439 | if (drop_connection(startups) == 1) { |
1440 | debug("drop connection #%d", startups); | |
089fbbd2 | 1441 | close(newsock); |
1442 | continue; | |
1443 | } | |
1444 | if (pipe(startup_p) == -1) { | |
1445 | close(newsock); | |
1446 | continue; | |
1447 | } | |
1448 | ||
b9a549d7 | 1449 | if (rexec_flag && socketpair(AF_UNIX, |
1450 | SOCK_STREAM, 0, config_s) == -1) { | |
1451 | error("reexec socketpair: %s", | |
1452 | strerror(errno)); | |
1453 | close(newsock); | |
1454 | close(startup_p[0]); | |
1455 | close(startup_p[1]); | |
1456 | continue; | |
1457 | } | |
1458 | ||
089fbbd2 | 1459 | for (j = 0; j < options.max_startups; j++) |
1460 | if (startup_pipes[j] == -1) { | |
1461 | startup_pipes[j] = startup_p[0]; | |
1462 | if (maxfd < startup_p[0]) | |
1463 | maxfd = startup_p[0]; | |
1464 | startups++; | |
1465 | break; | |
1466 | } | |
2b87da3b | 1467 | |
aa3378df | 1468 | /* |
089fbbd2 | 1469 | * Got connection. Fork a child to handle it, unless |
1470 | * we are in debugging mode. | |
aa3378df | 1471 | */ |
089fbbd2 | 1472 | if (debug_flag) { |
aa3378df | 1473 | /* |
089fbbd2 | 1474 | * In debugging mode. Close the listening |
1475 | * socket, and start processing the | |
1476 | * connection without forking. | |
aa3378df | 1477 | */ |
089fbbd2 | 1478 | debug("Server will not fork when running in debugging mode."); |
48e671d5 | 1479 | close_listen_socks(); |
5260325f | 1480 | sock_in = newsock; |
1481 | sock_out = newsock; | |
b9a549d7 | 1482 | close(startup_p[0]); |
1483 | close(startup_p[1]); | |
5540ea9b | 1484 | startup_pipe = -1; |
3f7a7e4a | 1485 | pid = getpid(); |
b9a549d7 | 1486 | if (rexec_flag) { |
1487 | send_rexec_state(config_s[0], | |
1488 | &cfg); | |
1489 | close(config_s[0]); | |
1490 | } | |
5260325f | 1491 | break; |
089fbbd2 | 1492 | } else { |
1493 | /* | |
1494 | * Normal production daemon. Fork, and have | |
1495 | * the child process the connection. The | |
1496 | * parent continues listening. | |
1497 | */ | |
1498 | if ((pid = fork()) == 0) { | |
1499 | /* | |
1500 | * Child. Close the listening and max_startup | |
1501 | * sockets. Start using the accepted socket. | |
1502 | * Reinitialize logging (since our pid has | |
1503 | * changed). We break out of the loop to handle | |
1504 | * the connection. | |
1505 | */ | |
1506 | startup_pipe = startup_p[1]; | |
7ace8c3b | 1507 | close_startup_pipes(); |
089fbbd2 | 1508 | close_listen_socks(); |
1509 | sock_in = newsock; | |
1510 | sock_out = newsock; | |
1fe6a48f | 1511 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
b250e837 | 1512 | close(config_s[0]); |
089fbbd2 | 1513 | break; |
1514 | } | |
5260325f | 1515 | } |
5260325f | 1516 | |
089fbbd2 | 1517 | /* Parent. Stay in the loop. */ |
1518 | if (pid < 0) | |
1519 | error("fork: %.100s", strerror(errno)); | |
1520 | else | |
c457707e | 1521 | debug("Forked child %ld.", (long)pid); |
5260325f | 1522 | |
089fbbd2 | 1523 | close(startup_p[1]); |
5260325f | 1524 | |
b9a549d7 | 1525 | if (rexec_flag) { |
1526 | send_rexec_state(config_s[0], &cfg); | |
1527 | close(config_s[0]); | |
1528 | close(config_s[1]); | |
1529 | } | |
1530 | ||
089fbbd2 | 1531 | /* Mark that the key has been used (it was "given" to the child). */ |
59c97189 | 1532 | if ((options.protocol & SSH_PROTO_1) && |
1533 | key_used == 0) { | |
1534 | /* Schedule server key regeneration alarm. */ | |
f00d1f78 | 1535 | signal(SIGALRM, key_regeneration_alarm); |
59c97189 | 1536 | alarm(options.key_regeneration_time); |
1537 | key_used = 1; | |
1538 | } | |
5260325f | 1539 | |
089fbbd2 | 1540 | arc4random_stir(); |
1541 | ||
1542 | /* Close the new socket (the child is now taking care of it). */ | |
1543 | close(newsock); | |
1544 | } | |
48e671d5 | 1545 | /* child process check (or debug mode) */ |
1546 | if (num_listen_socks < 0) | |
1547 | break; | |
5260325f | 1548 | } |
1549 | } | |
8efc0c15 | 1550 | |
5260325f | 1551 | /* This is the child processing a new connection. */ |
cc120685 | 1552 | setproctitle("%s", "[accepted]"); |
5260325f | 1553 | |
b9a549d7 | 1554 | if (rexec_flag) { |
1555 | int fd; | |
1556 | ||
b250e837 | 1557 | debug("rexec start in %d out %d newsock %d pipe %d sock %d", |
1558 | sock_in, sock_out, newsock, startup_pipe, config_s[0]); | |
b9a549d7 | 1559 | dup2(newsock, STDIN_FILENO); |
1560 | dup2(STDIN_FILENO, STDOUT_FILENO); | |
1561 | if (startup_pipe == -1) | |
b250e837 | 1562 | close(REEXEC_STARTUP_PIPE_FD); |
b9a549d7 | 1563 | else |
b250e837 | 1564 | dup2(startup_pipe, REEXEC_STARTUP_PIPE_FD); |
b9a549d7 | 1565 | |
b250e837 | 1566 | dup2(config_s[1], REEXEC_CONFIG_PASS_FD); |
b9a549d7 | 1567 | close(config_s[1]); |
b250e837 | 1568 | close(startup_pipe); |
1569 | ||
b9a549d7 | 1570 | execv(rexec_argv[0], rexec_argv); |
1571 | ||
1572 | /* Reexec has failed, fall back and continue */ | |
1573 | error("rexec of %s failed: %s", rexec_argv[0], strerror(errno)); | |
b250e837 | 1574 | recv_rexec_state(REEXEC_CONFIG_PASS_FD, NULL); |
b9a549d7 | 1575 | log_init(__progname, options.log_level, |
1576 | options.log_facility, log_stderr); | |
1577 | ||
1578 | /* Clean up fds */ | |
b250e837 | 1579 | startup_pipe = REEXEC_STARTUP_PIPE_FD; |
b9a549d7 | 1580 | close(config_s[1]); |
b250e837 | 1581 | close(REEXEC_CONFIG_PASS_FD); |
1582 | newsock = sock_out = sock_in = dup(STDIN_FILENO); | |
b9a549d7 | 1583 | if ((fd = open(_PATH_DEVNULL, O_RDWR, 0)) != -1) { |
1584 | dup2(fd, STDIN_FILENO); | |
1585 | dup2(fd, STDOUT_FILENO); | |
1586 | if (fd > STDERR_FILENO) | |
1587 | close(fd); | |
1588 | } | |
b250e837 | 1589 | debug("rexec cleanup in %d out %d newsock %d pipe %d sock %d", |
1590 | sock_in, sock_out, newsock, startup_pipe, config_s[0]); | |
b9a549d7 | 1591 | } |
1592 | ||
4ac8556b | 1593 | /* |
1594 | * Create a new session and process group since the 4.4BSD | |
1595 | * setlogin() affects the entire process group. We don't | |
1596 | * want the child to be able to affect the parent. | |
1597 | */ | |
ad84c479 | 1598 | #if !defined(SSHD_ACQUIRES_CTTY) |
6ecd00f8 | 1599 | /* |
ad84c479 | 1600 | * If setsid is called, on some platforms sshd will later acquire a |
1601 | * controlling terminal which will result in "could not set | |
1602 | * controlling tty" errors. | |
6ecd00f8 | 1603 | */ |
c28876e9 | 1604 | if (!debug_flag && !inetd_flag && setsid() < 0) |
4ac8556b | 1605 | error("setsid: %.100s", strerror(errno)); |
30321a9b | 1606 | #endif |
4ac8556b | 1607 | |
aa3378df | 1608 | /* |
1609 | * Disable the key regeneration alarm. We will not regenerate the | |
1610 | * key since we are no longer in a position to give it to anyone. We | |
1611 | * will not restart on SIGHUP since it no longer makes sense. | |
1612 | */ | |
5260325f | 1613 | alarm(0); |
1614 | signal(SIGALRM, SIG_DFL); | |
1615 | signal(SIGHUP, SIG_DFL); | |
1616 | signal(SIGTERM, SIG_DFL); | |
1617 | signal(SIGQUIT, SIG_DFL); | |
1618 | signal(SIGCHLD, SIG_DFL); | |
9aaf9be4 | 1619 | signal(SIGINT, SIG_DFL); |
5260325f | 1620 | |
fd573618 | 1621 | /* Set SO_KEEPALIVE if requested. */ |
1622 | if (options.tcp_keep_alive && | |
db518d9b | 1623 | setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, |
b5c334cc | 1624 | sizeof(on)) < 0) |
1625 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); | |
1626 | ||
aa3378df | 1627 | /* |
1628 | * Register our connection. This turns encryption off because we do | |
1629 | * not have a key. | |
1630 | */ | |
5260325f | 1631 | packet_set_connection(sock_in, sock_out); |
1632 | ||
1633 | remote_port = get_remote_port(); | |
1634 | remote_ip = get_remote_ipaddr(); | |
1635 | ||
5260325f | 1636 | #ifdef LIBWRAP |
ac28afd8 | 1637 | /* Check whether logins are denied from this host. */ |
33e5359c | 1638 | if (packet_connection_is_on_socket()) { |
5260325f | 1639 | struct request_info req; |
8efc0c15 | 1640 | |
8fbc356d | 1641 | request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0); |
5260325f | 1642 | fromhost(&req); |
8efc0c15 | 1643 | |
5260325f | 1644 | if (!hosts_access(&req)) { |
ac28afd8 | 1645 | debug("Connection refused by tcp wrapper"); |
563834bb | 1646 | refuse(&req); |
ac28afd8 | 1647 | /* NOTREACHED */ |
1648 | fatal("libwrap refuse returns"); | |
5260325f | 1649 | } |
8efc0c15 | 1650 | } |
48e671d5 | 1651 | #endif /* LIBWRAP */ |
ac28afd8 | 1652 | |
5260325f | 1653 | /* Log the connection. */ |
1654 | verbose("Connection from %.500s port %d", remote_ip, remote_port); | |
8efc0c15 | 1655 | |
aa3378df | 1656 | /* |
1657 | * We don\'t want to listen forever unless the other side | |
1658 | * successfully authenticates itself. So we set up an alarm which is | |
1659 | * cleared after successful authentication. A limit of zero | |
1660 | * indicates no limit. Note that we don\'t set the alarm in debugging | |
1661 | * mode; it is just annoying to have the server exit just when you | |
1662 | * are about to discover the bug. | |
1663 | */ | |
f00d1f78 | 1664 | signal(SIGALRM, grace_alarm_handler); |
5260325f | 1665 | if (!debug_flag) |
1666 | alarm(options.login_grace_time); | |
1667 | ||
7368a6c8 | 1668 | sshd_exchange_identification(sock_in, sock_out); |
0598d99d | 1669 | |
5260325f | 1670 | packet_set_nonblocking(); |
1671 | ||
aff51935 | 1672 | /* prepare buffers to collect authentication messages */ |
bc7dfc06 | 1673 | buffer_init(&loginmsg); |
1674 | ||
2362db19 | 1675 | /* allocate authentication context */ |
1676 | authctxt = xmalloc(sizeof(*authctxt)); | |
1677 | memset(authctxt, 0, sizeof(*authctxt)); | |
1678 | ||
1679 | /* XXX global for cleanup, access from other modules */ | |
1680 | the_authctxt = authctxt; | |
1681 | ||
324bf712 | 1682 | if (use_privsep) |
2362db19 | 1683 | if (privsep_preauth(authctxt) == 1) |
324bf712 | 1684 | goto authenticated; |
1853d1ef | 1685 | |
be2ca0c9 | 1686 | /* prepare buffer to collect messages to display to user after login */ |
1687 | buffer_init(&loginmsg); | |
1688 | ||
7b2ea3a1 | 1689 | /* perform the key exchange */ |
7b2ea3a1 | 1690 | /* authenticate user and start session */ |
e78a59f5 | 1691 | if (compat20) { |
1692 | do_ssh2_kex(); | |
2362db19 | 1693 | do_authentication2(authctxt); |
e78a59f5 | 1694 | } else { |
1695 | do_ssh1_kex(); | |
2362db19 | 1696 | do_authentication(authctxt); |
e78a59f5 | 1697 | } |
324bf712 | 1698 | /* |
1699 | * If we use privilege separation, the unprivileged child transfers | |
1700 | * the current keystate and exits | |
1701 | */ | |
1702 | if (use_privsep) { | |
b5a28cbc | 1703 | mm_send_keystate(pmonitor); |
1853d1ef | 1704 | exit(0); |
324bf712 | 1705 | } |
1853d1ef | 1706 | |
1707 | authenticated: | |
762715ce | 1708 | /* |
1853d1ef | 1709 | * In privilege separation, we fork another child and prepare |
1710 | * file descriptor passing. | |
1711 | */ | |
1712 | if (use_privsep) { | |
324bf712 | 1713 | privsep_postauth(authctxt); |
1714 | /* the monitor process [priv] will not return */ | |
1853d1ef | 1715 | if (!compat20) |
1716 | destroy_sensitive_data(); | |
1717 | } | |
1b34c1b3 | 1718 | |
2362db19 | 1719 | /* Start session. */ |
1b34c1b3 | 1720 | do_authenticated(authctxt); |
1721 | ||
63284fbb | 1722 | /* The connection has been terminated. */ |
1723 | verbose("Closing connection to %.100s", remote_ip); | |
8efc0c15 | 1724 | |
d94aa2ae | 1725 | #ifdef USE_PAM |
7fceb20d | 1726 | if (options.use_pam) |
1727 | finish_pam(); | |
d94aa2ae | 1728 | #endif /* USE_PAM */ |
8efc0c15 | 1729 | |
5260325f | 1730 | packet_close(); |
1853d1ef | 1731 | |
1732 | if (use_privsep) | |
1733 | mm_terminate(); | |
1734 | ||
5260325f | 1735 | exit(0); |
1736 | } | |
8efc0c15 | 1737 | |
4f08e98d | 1738 | /* |
1739 | * Decrypt session_key_int using our private server key and private host key | |
1740 | * (key with larger modulus first). | |
1741 | */ | |
1853d1ef | 1742 | int |
4f08e98d | 1743 | ssh1_session_key(BIGNUM *session_key_int) |
1744 | { | |
1745 | int rsafail = 0; | |
1746 | ||
1747 | if (BN_cmp(sensitive_data.server_key->rsa->n, sensitive_data.ssh1_host_key->rsa->n) > 0) { | |
1748 | /* Server key has bigger modulus. */ | |
1749 | if (BN_num_bits(sensitive_data.server_key->rsa->n) < | |
1750 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) { | |
1751 | fatal("do_connection: %s: server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d", | |
1752 | get_remote_ipaddr(), | |
1753 | BN_num_bits(sensitive_data.server_key->rsa->n), | |
1754 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), | |
1755 | SSH_KEY_BITS_RESERVED); | |
1756 | } | |
1757 | if (rsa_private_decrypt(session_key_int, session_key_int, | |
1758 | sensitive_data.server_key->rsa) <= 0) | |
1759 | rsafail++; | |
1760 | if (rsa_private_decrypt(session_key_int, session_key_int, | |
1761 | sensitive_data.ssh1_host_key->rsa) <= 0) | |
1762 | rsafail++; | |
1763 | } else { | |
1764 | /* Host key has bigger modulus (or they are equal). */ | |
1765 | if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) < | |
1766 | BN_num_bits(sensitive_data.server_key->rsa->n) + SSH_KEY_BITS_RESERVED) { | |
1767 | fatal("do_connection: %s: host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d", | |
1768 | get_remote_ipaddr(), | |
1769 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), | |
1770 | BN_num_bits(sensitive_data.server_key->rsa->n), | |
1771 | SSH_KEY_BITS_RESERVED); | |
1772 | } | |
1773 | if (rsa_private_decrypt(session_key_int, session_key_int, | |
1774 | sensitive_data.ssh1_host_key->rsa) < 0) | |
1775 | rsafail++; | |
1776 | if (rsa_private_decrypt(session_key_int, session_key_int, | |
1777 | sensitive_data.server_key->rsa) < 0) | |
1778 | rsafail++; | |
1779 | } | |
1780 | return (rsafail); | |
1781 | } | |
5260325f | 1782 | /* |
7b2ea3a1 | 1783 | * SSH1 key exchange |
5260325f | 1784 | */ |
396c147e | 1785 | static void |
1e3b8b07 | 1786 | do_ssh1_kex(void) |
8efc0c15 | 1787 | { |
5260325f | 1788 | int i, len; |
46aa2d1f | 1789 | int rsafail = 0; |
5260325f | 1790 | BIGNUM *session_key_int; |
1e3b8b07 | 1791 | u_char session_key[SSH_SESSION_KEY_LENGTH]; |
1792 | u_char cookie[8]; | |
1793 | u_int cipher_type, auth_mask, protocol_flags; | |
7fdc56c5 | 1794 | u_int32_t rnd = 0; |
5260325f | 1795 | |
aa3378df | 1796 | /* |
1797 | * Generate check bytes that the client must send back in the user | |
1798 | * packet in order for it to be accepted; this is used to defy ip | |
1799 | * spoofing attacks. Note that this only works against somebody | |
1800 | * doing IP spoofing from a remote machine; any machine on the local | |
1801 | * network can still see outgoing packets and catch the random | |
1802 | * cookie. This only affects rhosts authentication, and this is one | |
1803 | * of the reasons why it is inherently insecure. | |
1804 | */ | |
5260325f | 1805 | for (i = 0; i < 8; i++) { |
1806 | if (i % 4 == 0) | |
7fdc56c5 | 1807 | rnd = arc4random(); |
1808 | cookie[i] = rnd & 0xff; | |
1809 | rnd >>= 8; | |
5260325f | 1810 | } |
1811 | ||
aa3378df | 1812 | /* |
1813 | * Send our public key. We include in the packet 64 bits of random | |
1814 | * data that must be matched in the reply in order to prevent IP | |
1815 | * spoofing. | |
1816 | */ | |
5260325f | 1817 | packet_start(SSH_SMSG_PUBLIC_KEY); |
1818 | for (i = 0; i < 8; i++) | |
7b2ea3a1 | 1819 | packet_put_char(cookie[i]); |
5260325f | 1820 | |
1821 | /* Store our public server RSA key. */ | |
fa08c86b | 1822 | packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n)); |
1823 | packet_put_bignum(sensitive_data.server_key->rsa->e); | |
1824 | packet_put_bignum(sensitive_data.server_key->rsa->n); | |
5260325f | 1825 | |
1826 | /* Store our public host RSA key. */ | |
fa08c86b | 1827 | packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); |
1828 | packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e); | |
1829 | packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n); | |
5260325f | 1830 | |
1831 | /* Put protocol flags. */ | |
1832 | packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN); | |
1833 | ||
1834 | /* Declare which ciphers we support. */ | |
94ec8c6b | 1835 | packet_put_int(cipher_mask_ssh1(0)); |
5260325f | 1836 | |
1837 | /* Declare supported authentication types. */ | |
1838 | auth_mask = 0; | |
5260325f | 1839 | if (options.rhosts_rsa_authentication) |
1840 | auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA; | |
1841 | if (options.rsa_authentication) | |
1842 | auth_mask |= 1 << SSH_AUTH_RSA; | |
5ba55ada | 1843 | if (options.challenge_response_authentication == 1) |
5260325f | 1844 | auth_mask |= 1 << SSH_AUTH_TIS; |
5260325f | 1845 | if (options.password_authentication) |
1846 | auth_mask |= 1 << SSH_AUTH_PASSWORD; | |
1847 | packet_put_int(auth_mask); | |
1848 | ||
1849 | /* Send the packet and wait for it to be sent. */ | |
1850 | packet_send(); | |
1851 | packet_write_wait(); | |
1852 | ||
fa08c86b | 1853 | debug("Sent %d bit server key and %d bit host key.", |
1854 | BN_num_bits(sensitive_data.server_key->rsa->n), | |
1855 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); | |
5260325f | 1856 | |
1857 | /* Read clients reply (cipher type and session key). */ | |
54a5250f | 1858 | packet_read_expect(SSH_CMSG_SESSION_KEY); |
5260325f | 1859 | |
2d86a6cc | 1860 | /* Get cipher type and check whether we accept this. */ |
5260325f | 1861 | cipher_type = packet_get_char(); |
1862 | ||
94ec8c6b | 1863 | if (!(cipher_mask_ssh1(0) & (1 << cipher_type))) |
2d86a6cc | 1864 | packet_disconnect("Warning: client selects unsupported cipher."); |
1865 | ||
5260325f | 1866 | /* Get check bytes from the packet. These must match those we |
1867 | sent earlier with the public key packet. */ | |
1868 | for (i = 0; i < 8; i++) | |
7b2ea3a1 | 1869 | if (cookie[i] != packet_get_char()) |
5260325f | 1870 | packet_disconnect("IP Spoofing check bytes do not match."); |
1871 | ||
1872 | debug("Encryption type: %.200s", cipher_name(cipher_type)); | |
1873 | ||
1874 | /* Get the encrypted integer. */ | |
b775c6f2 | 1875 | if ((session_key_int = BN_new()) == NULL) |
1876 | fatal("do_ssh1_kex: BN_new failed"); | |
20b279e6 | 1877 | packet_get_bignum(session_key_int); |
5260325f | 1878 | |
5260325f | 1879 | protocol_flags = packet_get_int(); |
1880 | packet_set_protocol_flags(protocol_flags); | |
95500969 | 1881 | packet_check_eom(); |
5260325f | 1882 | |
4f08e98d | 1883 | /* Decrypt session_key_int using host/server keys */ |
1853d1ef | 1884 | rsafail = PRIVSEP(ssh1_session_key(session_key_int)); |
1885 | ||
aa3378df | 1886 | /* |
1887 | * Extract session key from the decrypted integer. The key is in the | |
1888 | * least significant 256 bits of the integer; the first byte of the | |
1889 | * key is in the highest bits. | |
1890 | */ | |
46aa2d1f | 1891 | if (!rsafail) { |
1892 | BN_mask_bits(session_key_int, sizeof(session_key) * 8); | |
1893 | len = BN_num_bytes(session_key_int); | |
1894 | if (len < 0 || len > sizeof(session_key)) { | |
1895 | error("do_connection: bad session key len from %s: " | |
5ca51e19 | 1896 | "session_key_int %d > sizeof(session_key) %lu", |
1897 | get_remote_ipaddr(), len, (u_long)sizeof(session_key)); | |
46aa2d1f | 1898 | rsafail++; |
1899 | } else { | |
1900 | memset(session_key, 0, sizeof(session_key)); | |
1901 | BN_bn2bin(session_key_int, | |
1902 | session_key + sizeof(session_key) - len); | |
00be5382 | 1903 | |
8bbf1fa6 | 1904 | derive_ssh1_session_id( |
f2107e97 | 1905 | sensitive_data.ssh1_host_key->rsa->n, |
8bbf1fa6 | 1906 | sensitive_data.server_key->rsa->n, |
1907 | cookie, session_id); | |
00be5382 | 1908 | /* |
1909 | * Xor the first 16 bytes of the session key with the | |
1910 | * session id. | |
1911 | */ | |
1912 | for (i = 0; i < 16; i++) | |
1913 | session_key[i] ^= session_id[i]; | |
46aa2d1f | 1914 | } |
1915 | } | |
1916 | if (rsafail) { | |
00be5382 | 1917 | int bytes = BN_num_bytes(session_key_int); |
f6b1ba8f | 1918 | u_char *buf = xmalloc(bytes); |
00be5382 | 1919 | MD5_CTX md; |
1920 | ||
bbe88b6d | 1921 | logit("do_connection: generating a fake encryption key"); |
00be5382 | 1922 | BN_bn2bin(session_key_int, buf); |
1923 | MD5_Init(&md); | |
1924 | MD5_Update(&md, buf, bytes); | |
1925 | MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); | |
1926 | MD5_Final(session_key, &md); | |
1927 | MD5_Init(&md); | |
1928 | MD5_Update(&md, session_key, 16); | |
1929 | MD5_Update(&md, buf, bytes); | |
1930 | MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); | |
1931 | MD5_Final(session_key + 16, &md); | |
1932 | memset(buf, 0, bytes); | |
1933 | xfree(buf); | |
0572fe75 | 1934 | for (i = 0; i < 16; i++) |
1935 | session_id[i] = session_key[i] ^ session_key[i + 16]; | |
46aa2d1f | 1936 | } |
1853d1ef | 1937 | /* Destroy the private and public keys. No longer. */ |
63284fbb | 1938 | destroy_sensitive_data(); |
00be5382 | 1939 | |
1853d1ef | 1940 | if (use_privsep) |
1941 | mm_ssh1_session_id(session_id); | |
1942 | ||
7b2ea3a1 | 1943 | /* Destroy the decrypted integer. It is no longer needed. */ |
1944 | BN_clear_free(session_key_int); | |
1945 | ||
5260325f | 1946 | /* Set the session key. From this on all communications will be encrypted. */ |
1947 | packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type); | |
1948 | ||
1949 | /* Destroy our copy of the session key. It is no longer needed. */ | |
1950 | memset(session_key, 0, sizeof(session_key)); | |
1951 | ||
1952 | debug("Received session key; encryption turned on."); | |
1953 | ||
c242fc96 | 1954 | /* Send an acknowledgment packet. Note that this packet is sent encrypted. */ |
5260325f | 1955 | packet_start(SSH_SMSG_SUCCESS); |
1956 | packet_send(); | |
1957 | packet_write_wait(); | |
5260325f | 1958 | } |
e78a59f5 | 1959 | |
1960 | /* | |
1961 | * SSH2 key exchange: diffie-hellman-group1-sha1 | |
1962 | */ | |
396c147e | 1963 | static void |
1e3b8b07 | 1964 | do_ssh2_kex(void) |
e78a59f5 | 1965 | { |
e78a59f5 | 1966 | Kex *kex; |
e78a59f5 | 1967 | |
a8be9f80 | 1968 | if (options.ciphers != NULL) { |
6ae2364d | 1969 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
a8be9f80 | 1970 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; |
1971 | } | |
1ad64a93 | 1972 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
1973 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
1974 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
1975 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
1976 | ||
b2552997 | 1977 | if (options.macs != NULL) { |
1978 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
1979 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
1980 | } | |
636f76ca | 1981 | if (!options.compression) { |
1982 | myproposal[PROPOSAL_COMP_ALGS_CTOS] = | |
1983 | myproposal[PROPOSAL_COMP_ALGS_STOC] = "none"; | |
1984 | } | |
fa08c86b | 1985 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types(); |
1986 | ||
7a37c112 | 1987 | /* start key exchange */ |
d8ee838b | 1988 | kex = kex_setup(myproposal); |
98a58eda | 1989 | kex->kex[KEX_DH_GRP1_SHA1] = kexdh_server; |
41e5bd9a | 1990 | kex->kex[KEX_DH_GRP14_SHA1] = kexdh_server; |
98a58eda | 1991 | kex->kex[KEX_DH_GEX_SHA1] = kexgex_server; |
a5c9ffdb | 1992 | kex->server = 1; |
1993 | kex->client_version_string=client_version_string; | |
1994 | kex->server_version_string=server_version_string; | |
1995 | kex->load_host_key=&get_hostkey_by_type; | |
1853d1ef | 1996 | kex->host_key_index=&get_hostkey_index; |
94ec8c6b | 1997 | |
7a37c112 | 1998 | xxx_kex = kex; |
1999 | ||
c422989b | 2000 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); |
94ec8c6b | 2001 | |
d1ac6175 | 2002 | session_id2 = kex->session_id; |
2003 | session_id2_len = kex->session_id_len; | |
2004 | ||
94ec8c6b | 2005 | #ifdef DEBUG_KEXDH |
2006 | /* send 1st encrypted/maced/compressed message */ | |
2007 | packet_start(SSH2_MSG_IGNORE); | |
2008 | packet_put_cstring("markus"); | |
2009 | packet_send(); | |
2010 | packet_write_wait(); | |
2011 | #endif | |
a5c9ffdb | 2012 | debug("KEX done"); |
e78a59f5 | 2013 | } |
2362db19 | 2014 | |
2015 | /* server specific fatal cleanup */ | |
2016 | void | |
2017 | cleanup_exit(int i) | |
2018 | { | |
2019 | if (the_authctxt) | |
2020 | do_cleanup(the_authctxt); | |
2021 | _exit(i); | |
2022 | } |