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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: | |
18 | * | |
19 | * Copyright (c) 2000 Markus Friedl. All rights reserved. | |
20 | * | |
21 | * Redistribution and use in source and binary forms, with or without | |
22 | * modification, are permitted provided that the following conditions | |
23 | * are met: | |
24 | * 1. Redistributions of source code must retain the above copyright | |
25 | * notice, this list of conditions and the following disclaimer. | |
26 | * 2. Redistributions in binary form must reproduce the above copyright | |
27 | * notice, this list of conditions and the following disclaimer in the | |
28 | * documentation and/or other materials provided with the distribution. | |
29 | * | |
30 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR | |
31 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
32 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
33 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
34 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
35 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
36 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
37 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
38 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
39 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
5260325f | 40 | */ |
8efc0c15 | 41 | |
42 | #include "includes.h" | |
a8a21a53 | 43 | RCSID("$OpenBSD: sshd.c,v 1.219 2001/12/27 20:39:58 markus Exp $"); |
8efc0c15 | 44 | |
42f11eb2 | 45 | #include <openssl/dh.h> |
46 | #include <openssl/bn.h> | |
47 | #include <openssl/hmac.h> | |
48 | ||
49 | #include "ssh.h" | |
50 | #include "ssh1.h" | |
51 | #include "ssh2.h" | |
8efc0c15 | 52 | #include "xmalloc.h" |
53 | #include "rsa.h" | |
1729c161 | 54 | #include "sshpty.h" |
8efc0c15 | 55 | #include "packet.h" |
8efc0c15 | 56 | #include "mpaux.h" |
42f11eb2 | 57 | #include "log.h" |
8efc0c15 | 58 | #include "servconf.h" |
59 | #include "uidswap.h" | |
60 | #include "compat.h" | |
7368a6c8 | 61 | #include "buffer.h" |
42f11eb2 | 62 | #include "cipher.h" |
e78a59f5 | 63 | #include "kex.h" |
7368a6c8 | 64 | #include "key.h" |
94ec8c6b | 65 | #include "dh.h" |
e78a59f5 | 66 | #include "myproposal.h" |
a306f2dd | 67 | #include "authfile.h" |
42f11eb2 | 68 | #include "pathnames.h" |
69 | #include "atomicio.h" | |
70 | #include "canohost.h" | |
71 | #include "auth.h" | |
72 | #include "misc.h" | |
a5c9ffdb | 73 | #include "dispatch.h" |
e4d7f734 | 74 | #include "channels.h" |
8efc0c15 | 75 | |
76 | #ifdef LIBWRAP | |
77 | #include <tcpd.h> | |
78 | #include <syslog.h> | |
79 | int allow_severity = LOG_INFO; | |
80 | int deny_severity = LOG_WARNING; | |
81 | #endif /* LIBWRAP */ | |
82 | ||
83 | #ifndef O_NOCTTY | |
84 | #define O_NOCTTY 0 | |
85 | #endif | |
86 | ||
260d427b | 87 | #ifdef HAVE___PROGNAME |
88 | extern char *__progname; | |
89 | #else | |
90 | char *__progname; | |
91 | #endif | |
92 | ||
8efc0c15 | 93 | /* Server configuration options. */ |
94 | ServerOptions options; | |
95 | ||
96 | /* Name of the server configuration file. */ | |
42f11eb2 | 97 | char *config_file_name = _PATH_SERVER_CONFIG_FILE; |
8efc0c15 | 98 | |
6ae2364d | 99 | /* |
48e671d5 | 100 | * Flag indicating whether IPv4 or IPv6. This can be set on the command line. |
101 | * Default value is AF_UNSPEC means both IPv4 and IPv6. | |
102 | */ | |
59e76f33 | 103 | #ifdef IPV4_DEFAULT |
104 | int IPv4or6 = AF_INET; | |
105 | #else | |
48e671d5 | 106 | int IPv4or6 = AF_UNSPEC; |
59e76f33 | 107 | #endif |
48e671d5 | 108 | |
5260325f | 109 | /* |
110 | * Debug mode flag. This can be set on the command line. If debug | |
111 | * mode is enabled, extra debugging output will be sent to the system | |
112 | * log, the daemon will not go to background, and will exit after processing | |
113 | * the first connection. | |
114 | */ | |
8efc0c15 | 115 | int debug_flag = 0; |
116 | ||
f87f09aa | 117 | /* Flag indicating that the daemon should only test the configuration and keys. */ |
118 | int test_flag = 0; | |
119 | ||
8efc0c15 | 120 | /* Flag indicating that the daemon is being started from inetd. */ |
121 | int inetd_flag = 0; | |
122 | ||
0b6fbf03 | 123 | /* Flag indicating that sshd should not detach and become a daemon. */ |
124 | int no_daemon_flag = 0; | |
125 | ||
6a17f9c2 | 126 | /* debug goes to stderr unless inetd_flag is set */ |
127 | int log_stderr = 0; | |
128 | ||
8efc0c15 | 129 | /* Saved arguments to main(). */ |
130 | char **saved_argv; | |
4d33e531 | 131 | int saved_argc; |
8efc0c15 | 132 | |
aa3378df | 133 | /* |
48e671d5 | 134 | * The sockets that the server is listening; this is used in the SIGHUP |
135 | * signal handler. | |
aa3378df | 136 | */ |
48e671d5 | 137 | #define MAX_LISTEN_SOCKS 16 |
138 | int listen_socks[MAX_LISTEN_SOCKS]; | |
139 | int num_listen_socks = 0; | |
8efc0c15 | 140 | |
aa3378df | 141 | /* |
142 | * the client's version string, passed by sshd2 in compat mode. if != NULL, | |
143 | * sshd will skip the version-number exchange | |
144 | */ | |
5260325f | 145 | char *client_version_string = NULL; |
7368a6c8 | 146 | char *server_version_string = NULL; |
8efc0c15 | 147 | |
7a37c112 | 148 | /* for rekeying XXX fixme */ |
149 | Kex *xxx_kex; | |
150 | ||
aa3378df | 151 | /* |
152 | * Any really sensitive data in the application is contained in this | |
153 | * structure. The idea is that this structure could be locked into memory so | |
154 | * that the pages do not get written into swap. However, there are some | |
155 | * problems. The private key contains BIGNUMs, and we do not (in principle) | |
156 | * have access to the internals of them, and locking just the structure is | |
157 | * not very useful. Currently, memory locking is not implemented. | |
158 | */ | |
5260325f | 159 | struct { |
cb7bd922 | 160 | Key *server_key; /* ephemeral server key */ |
fa08c86b | 161 | Key *ssh1_host_key; /* ssh1 host key */ |
162 | Key **host_keys; /* all private host keys */ | |
163 | int have_ssh1_key; | |
164 | int have_ssh2_key; | |
00be5382 | 165 | u_char ssh1_cookie[SSH_SESSION_KEY_LENGTH]; |
8efc0c15 | 166 | } sensitive_data; |
167 | ||
aa3378df | 168 | /* |
59c97189 | 169 | * Flag indicating whether the RSA server key needs to be regenerated. |
170 | * Is set in the SIGALRM handler and cleared when the key is regenerated. | |
aa3378df | 171 | */ |
7a934d1b | 172 | static volatile sig_atomic_t key_do_regen = 0; |
8efc0c15 | 173 | |
c9130033 | 174 | /* This is set to true when a signal is received. */ |
7a934d1b | 175 | static volatile sig_atomic_t received_sighup = 0; |
176 | static volatile sig_atomic_t received_sigterm = 0; | |
8efc0c15 | 177 | |
7368a6c8 | 178 | /* session identifier, used by RSA-auth */ |
1e3b8b07 | 179 | u_char session_id[16]; |
e7c0f9d5 | 180 | |
a306f2dd | 181 | /* same for ssh2 */ |
1e3b8b07 | 182 | u_char *session_id2 = NULL; |
a306f2dd | 183 | int session_id2_len = 0; |
184 | ||
c345cf9d | 185 | /* record remote hostname or ip */ |
1e3b8b07 | 186 | u_int utmp_len = MAXHOSTNAMELEN; |
c345cf9d | 187 | |
7ace8c3b | 188 | /* options.max_startup sized array of fd ints */ |
189 | int *startup_pipes = NULL; | |
190 | int startup_pipe; /* in child */ | |
191 | ||
7368a6c8 | 192 | /* Prototypes for various functions defined later in this file. */ |
396c147e | 193 | void destroy_sensitive_data(void); |
c8d54615 | 194 | |
396c147e | 195 | static void do_ssh1_kex(void); |
196 | static void do_ssh2_kex(void); | |
94ec8c6b | 197 | |
48e671d5 | 198 | /* |
199 | * Close all listening sockets | |
200 | */ | |
396c147e | 201 | static void |
48e671d5 | 202 | close_listen_socks(void) |
203 | { | |
204 | int i; | |
205 | for (i = 0; i < num_listen_socks; i++) | |
206 | close(listen_socks[i]); | |
207 | num_listen_socks = -1; | |
208 | } | |
209 | ||
7ace8c3b | 210 | static void |
211 | close_startup_pipes(void) | |
212 | { | |
213 | int i; | |
214 | if (startup_pipes) | |
215 | for (i = 0; i < options.max_startups; i++) | |
216 | if (startup_pipes[i] != -1) | |
217 | close(startup_pipes[i]); | |
218 | } | |
219 | ||
5260325f | 220 | /* |
221 | * Signal handler for SIGHUP. Sshd execs itself when it receives SIGHUP; | |
222 | * the effect is to reread the configuration file (and to regenerate | |
223 | * the server key). | |
224 | */ | |
396c147e | 225 | static void |
5260325f | 226 | sighup_handler(int sig) |
8efc0c15 | 227 | { |
6056eb35 | 228 | int save_errno = errno; |
229 | ||
5260325f | 230 | received_sighup = 1; |
231 | signal(SIGHUP, sighup_handler); | |
6056eb35 | 232 | errno = save_errno; |
8efc0c15 | 233 | } |
234 | ||
5260325f | 235 | /* |
236 | * Called from the main program after receiving SIGHUP. | |
237 | * Restarts the server. | |
238 | */ | |
396c147e | 239 | static void |
5ca51e19 | 240 | sighup_restart(void) |
8efc0c15 | 241 | { |
5260325f | 242 | log("Received SIGHUP; restarting."); |
48e671d5 | 243 | close_listen_socks(); |
7ace8c3b | 244 | close_startup_pipes(); |
5260325f | 245 | execv(saved_argv[0], saved_argv); |
1fe6a48f | 246 | log("RESTART FAILED: av[0]='%.100s', error: %.100s.", saved_argv[0], strerror(errno)); |
5260325f | 247 | exit(1); |
8efc0c15 | 248 | } |
249 | ||
5260325f | 250 | /* |
251 | * Generic signal handler for terminating signals in the master daemon. | |
5260325f | 252 | */ |
396c147e | 253 | static void |
5260325f | 254 | sigterm_handler(int sig) |
8efc0c15 | 255 | { |
c9130033 | 256 | received_sigterm = sig; |
8efc0c15 | 257 | } |
258 | ||
5260325f | 259 | /* |
260 | * SIGCHLD handler. This is called whenever a child dies. This will then | |
c9130033 | 261 | * reap any zombies left by exited children. |
5260325f | 262 | */ |
396c147e | 263 | static void |
5260325f | 264 | main_sigchld_handler(int sig) |
8efc0c15 | 265 | { |
5260325f | 266 | int save_errno = errno; |
267 | int status; | |
5ad13cd7 | 268 | |
5260325f | 269 | while (waitpid(-1, &status, WNOHANG) > 0) |
270 | ; | |
5ad13cd7 | 271 | |
5260325f | 272 | signal(SIGCHLD, main_sigchld_handler); |
273 | errno = save_errno; | |
8efc0c15 | 274 | } |
275 | ||
5260325f | 276 | /* |
277 | * Signal handler for the alarm after the login grace period has expired. | |
278 | */ | |
396c147e | 279 | static void |
5260325f | 280 | grace_alarm_handler(int sig) |
8efc0c15 | 281 | { |
c9130033 | 282 | /* XXX no idea how fix this signal handler */ |
283 | ||
5260325f | 284 | /* Close the connection. */ |
285 | packet_close(); | |
8efc0c15 | 286 | |
5260325f | 287 | /* Log error and exit. */ |
288 | fatal("Timeout before authentication for %s.", get_remote_ipaddr()); | |
289 | } | |
8efc0c15 | 290 | |
5260325f | 291 | /* |
292 | * Signal handler for the key regeneration alarm. Note that this | |
293 | * alarm only occurs in the daemon waiting for connections, and it does not | |
294 | * do anything with the private key or random state before forking. | |
295 | * Thus there should be no concurrency control/asynchronous execution | |
296 | * problems. | |
297 | */ | |
396c147e | 298 | static void |
cb7bd922 | 299 | generate_ephemeral_server_key(void) |
fa08c86b | 300 | { |
00be5382 | 301 | u_int32_t rand = 0; |
302 | int i; | |
303 | ||
cd332296 | 304 | verbose("Generating %s%d bit RSA key.", |
76ca7b01 | 305 | sensitive_data.server_key ? "new " : "", options.server_key_bits); |
fa08c86b | 306 | if (sensitive_data.server_key != NULL) |
307 | key_free(sensitive_data.server_key); | |
cd332296 | 308 | sensitive_data.server_key = key_generate(KEY_RSA1, |
76ca7b01 | 309 | options.server_key_bits); |
310 | verbose("RSA key generation complete."); | |
00be5382 | 311 | |
312 | for (i = 0; i < SSH_SESSION_KEY_LENGTH; i++) { | |
313 | if (i % 4 == 0) | |
314 | rand = arc4random(); | |
315 | sensitive_data.ssh1_cookie[i] = rand & 0xff; | |
316 | rand >>= 8; | |
317 | } | |
318 | arc4random_stir(); | |
fa08c86b | 319 | } |
f546c780 | 320 | |
396c147e | 321 | static void |
5260325f | 322 | key_regeneration_alarm(int sig) |
323 | { | |
324 | int save_errno = errno; | |
59c97189 | 325 | signal(SIGALRM, SIG_DFL); |
5260325f | 326 | errno = save_errno; |
59c97189 | 327 | key_do_regen = 1; |
5260325f | 328 | } |
8efc0c15 | 329 | |
396c147e | 330 | static void |
7368a6c8 | 331 | sshd_exchange_identification(int sock_in, int sock_out) |
332 | { | |
a8be9f80 | 333 | int i, mismatch; |
7368a6c8 | 334 | int remote_major, remote_minor; |
a8be9f80 | 335 | int major, minor; |
7368a6c8 | 336 | char *s; |
337 | char buf[256]; /* Must not be larger than remote_version. */ | |
338 | char remote_version[256]; /* Must be at least as big as buf. */ | |
339 | ||
a8be9f80 | 340 | if ((options.protocol & SSH_PROTO_1) && |
341 | (options.protocol & SSH_PROTO_2)) { | |
342 | major = PROTOCOL_MAJOR_1; | |
343 | minor = 99; | |
344 | } else if (options.protocol & SSH_PROTO_2) { | |
345 | major = PROTOCOL_MAJOR_2; | |
346 | minor = PROTOCOL_MINOR_2; | |
347 | } else { | |
348 | major = PROTOCOL_MAJOR_1; | |
349 | minor = PROTOCOL_MINOR_1; | |
350 | } | |
351 | snprintf(buf, sizeof buf, "SSH-%d.%d-%.100s\n", major, minor, SSH_VERSION); | |
7368a6c8 | 352 | server_version_string = xstrdup(buf); |
353 | ||
354 | if (client_version_string == NULL) { | |
355 | /* Send our protocol version identification. */ | |
356 | if (atomicio(write, sock_out, server_version_string, strlen(server_version_string)) | |
357 | != strlen(server_version_string)) { | |
30f60c34 | 358 | log("Could not write ident string to %s", get_remote_ipaddr()); |
7368a6c8 | 359 | fatal_cleanup(); |
360 | } | |
361 | ||
2ce1adf9 | 362 | /* Read other side's version identification. */ |
cd332296 | 363 | memset(buf, 0, sizeof(buf)); |
7368a6c8 | 364 | for (i = 0; i < sizeof(buf) - 1; i++) { |
e5a0294f | 365 | if (atomicio(read, sock_in, &buf[i], 1) != 1) { |
30f60c34 | 366 | log("Did not receive identification string from %s", |
c2b544a5 | 367 | get_remote_ipaddr()); |
7368a6c8 | 368 | fatal_cleanup(); |
369 | } | |
370 | if (buf[i] == '\r') { | |
8a169574 | 371 | buf[i] = 0; |
94ec8c6b | 372 | /* Kludge for F-Secure Macintosh < 1.0.2 */ |
373 | if (i == 12 && | |
374 | strncmp(buf, "SSH-1.5-W1.0", 12) == 0) | |
375 | break; | |
7368a6c8 | 376 | continue; |
7368a6c8 | 377 | } |
378 | if (buf[i] == '\n') { | |
8a169574 | 379 | buf[i] = 0; |
7368a6c8 | 380 | break; |
381 | } | |
382 | } | |
383 | buf[sizeof(buf) - 1] = 0; | |
384 | client_version_string = xstrdup(buf); | |
385 | } | |
386 | ||
387 | /* | |
388 | * Check that the versions match. In future this might accept | |
389 | * several versions and set appropriate flags to handle them. | |
390 | */ | |
391 | if (sscanf(client_version_string, "SSH-%d.%d-%[^\n]\n", | |
392 | &remote_major, &remote_minor, remote_version) != 3) { | |
6ae2364d | 393 | s = "Protocol mismatch.\n"; |
7368a6c8 | 394 | (void) atomicio(write, sock_out, s, strlen(s)); |
395 | close(sock_in); | |
396 | close(sock_out); | |
397 | log("Bad protocol version identification '%.100s' from %s", | |
398 | client_version_string, get_remote_ipaddr()); | |
399 | fatal_cleanup(); | |
400 | } | |
401 | debug("Client protocol version %d.%d; client software version %.100s", | |
184eed6a | 402 | remote_major, remote_minor, remote_version); |
7368a6c8 | 403 | |
e78a59f5 | 404 | compat_datafellows(remote_version); |
405 | ||
3a1c54d4 | 406 | if (datafellows & SSH_BUG_SCANNER) { |
407 | log("scanned from %s with %s. Don't panic.", | |
408 | get_remote_ipaddr(), client_version_string); | |
409 | fatal_cleanup(); | |
410 | } | |
411 | ||
a8be9f80 | 412 | mismatch = 0; |
6aacefa7 | 413 | switch (remote_major) { |
7368a6c8 | 414 | case 1: |
a306f2dd | 415 | if (remote_minor == 99) { |
416 | if (options.protocol & SSH_PROTO_2) | |
417 | enable_compat20(); | |
418 | else | |
419 | mismatch = 1; | |
420 | break; | |
421 | } | |
a8be9f80 | 422 | if (!(options.protocol & SSH_PROTO_1)) { |
423 | mismatch = 1; | |
424 | break; | |
425 | } | |
7368a6c8 | 426 | if (remote_minor < 3) { |
089fbbd2 | 427 | packet_disconnect("Your ssh version is too old and " |
7368a6c8 | 428 | "is no longer supported. Please install a newer version."); |
429 | } else if (remote_minor == 3) { | |
430 | /* note that this disables agent-forwarding */ | |
431 | enable_compat13(); | |
432 | } | |
a8be9f80 | 433 | break; |
e78a59f5 | 434 | case 2: |
a8be9f80 | 435 | if (options.protocol & SSH_PROTO_2) { |
e78a59f5 | 436 | enable_compat20(); |
437 | break; | |
438 | } | |
439 | /* FALLTHROUGH */ | |
6ae2364d | 440 | default: |
a8be9f80 | 441 | mismatch = 1; |
442 | break; | |
443 | } | |
444 | chop(server_version_string); | |
a8be9f80 | 445 | debug("Local version string %.200s", server_version_string); |
446 | ||
447 | if (mismatch) { | |
7368a6c8 | 448 | s = "Protocol major versions differ.\n"; |
449 | (void) atomicio(write, sock_out, s, strlen(s)); | |
450 | close(sock_in); | |
451 | close(sock_out); | |
a8be9f80 | 452 | log("Protocol major versions differ for %s: %.200s vs. %.200s", |
453 | get_remote_ipaddr(), | |
454 | server_version_string, client_version_string); | |
7368a6c8 | 455 | fatal_cleanup(); |
7368a6c8 | 456 | } |
a306f2dd | 457 | } |
458 | ||
459 | ||
fa08c86b | 460 | /* Destroy the host and server keys. They will no longer be needed. */ |
a306f2dd | 461 | void |
462 | destroy_sensitive_data(void) | |
463 | { | |
fa08c86b | 464 | int i; |
465 | ||
466 | if (sensitive_data.server_key) { | |
467 | key_free(sensitive_data.server_key); | |
468 | sensitive_data.server_key = NULL; | |
469 | } | |
184eed6a | 470 | for (i = 0; i < options.num_host_key_files; i++) { |
fa08c86b | 471 | if (sensitive_data.host_keys[i]) { |
472 | key_free(sensitive_data.host_keys[i]); | |
473 | sensitive_data.host_keys[i] = NULL; | |
474 | } | |
475 | } | |
476 | sensitive_data.ssh1_host_key = NULL; | |
00be5382 | 477 | memset(sensitive_data.ssh1_cookie, 0, SSH_SESSION_KEY_LENGTH); |
fa08c86b | 478 | } |
fa08c86b | 479 | |
396c147e | 480 | static char * |
fa08c86b | 481 | list_hostkey_types(void) |
482 | { | |
483 | static char buf[1024]; | |
484 | int i; | |
485 | buf[0] = '\0'; | |
184eed6a | 486 | for (i = 0; i < options.num_host_key_files; i++) { |
fa08c86b | 487 | Key *key = sensitive_data.host_keys[i]; |
488 | if (key == NULL) | |
489 | continue; | |
6aacefa7 | 490 | switch (key->type) { |
fa08c86b | 491 | case KEY_RSA: |
492 | case KEY_DSA: | |
493 | strlcat(buf, key_ssh_name(key), sizeof buf); | |
494 | strlcat(buf, ",", sizeof buf); | |
495 | break; | |
496 | } | |
497 | } | |
498 | i = strlen(buf); | |
499 | if (i > 0 && buf[i-1] == ',') | |
500 | buf[i-1] = '\0'; | |
501 | debug("list_hostkey_types: %s", buf); | |
502 | return buf; | |
503 | } | |
504 | ||
396c147e | 505 | static Key * |
fa08c86b | 506 | get_hostkey_by_type(int type) |
507 | { | |
508 | int i; | |
184eed6a | 509 | for (i = 0; i < options.num_host_key_files; i++) { |
fa08c86b | 510 | Key *key = sensitive_data.host_keys[i]; |
511 | if (key != NULL && key->type == type) | |
512 | return key; | |
513 | } | |
514 | return NULL; | |
7368a6c8 | 515 | } |
516 | ||
c345cf9d | 517 | /* |
518 | * returns 1 if connection should be dropped, 0 otherwise. | |
519 | * dropping starts at connection #max_startups_begin with a probability | |
520 | * of (max_startups_rate/100). the probability increases linearly until | |
521 | * all connections are dropped for startups > max_startups | |
522 | */ | |
396c147e | 523 | static int |
c345cf9d | 524 | drop_connection(int startups) |
525 | { | |
526 | double p, r; | |
527 | ||
528 | if (startups < options.max_startups_begin) | |
529 | return 0; | |
530 | if (startups >= options.max_startups) | |
531 | return 1; | |
532 | if (options.max_startups_rate == 100) | |
533 | return 1; | |
534 | ||
535 | p = 100 - options.max_startups_rate; | |
536 | p *= startups - options.max_startups_begin; | |
537 | p /= (double) (options.max_startups - options.max_startups_begin); | |
538 | p += options.max_startups_rate; | |
539 | p /= 100.0; | |
540 | r = arc4random() / (double) UINT_MAX; | |
541 | ||
542 | debug("drop_connection: p %g, r %g", p, r); | |
543 | return (r < p) ? 1 : 0; | |
544 | } | |
545 | ||
2717fa0f | 546 | static void |
547 | usage(void) | |
548 | { | |
549 | fprintf(stderr, "sshd version %s\n", SSH_VERSION); | |
550 | fprintf(stderr, "Usage: %s [options]\n", __progname); | |
551 | fprintf(stderr, "Options:\n"); | |
552 | fprintf(stderr, " -f file Configuration file (default %s)\n", _PATH_SERVER_CONFIG_FILE); | |
553 | fprintf(stderr, " -d Debugging mode (multiple -d means more debugging)\n"); | |
554 | fprintf(stderr, " -i Started from inetd\n"); | |
555 | fprintf(stderr, " -D Do not fork into daemon mode\n"); | |
556 | fprintf(stderr, " -t Only test configuration file and keys\n"); | |
557 | fprintf(stderr, " -q Quiet (no logging)\n"); | |
558 | fprintf(stderr, " -p port Listen on the specified port (default: 22)\n"); | |
559 | fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n"); | |
560 | fprintf(stderr, " -g seconds Grace period for authentication (default: 600)\n"); | |
561 | fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n"); | |
562 | fprintf(stderr, " -h file File from which to read host key (default: %s)\n", | |
563 | _PATH_HOST_KEY_FILE); | |
564 | fprintf(stderr, " -u len Maximum hostname length for utmp recording\n"); | |
565 | fprintf(stderr, " -4 Use IPv4 only\n"); | |
566 | fprintf(stderr, " -6 Use IPv6 only\n"); | |
567 | fprintf(stderr, " -o option Process the option as if it was read from a configuration file.\n"); | |
568 | exit(1); | |
569 | } | |
570 | ||
5260325f | 571 | /* |
572 | * Main program for the daemon. | |
573 | */ | |
8efc0c15 | 574 | int |
575 | main(int ac, char **av) | |
576 | { | |
5260325f | 577 | extern char *optarg; |
578 | extern int optind; | |
089fbbd2 | 579 | int opt, sock_in = 0, sock_out = 0, newsock, j, i, fdsetsz, on = 1; |
9da5c3c9 | 580 | pid_t pid; |
48e671d5 | 581 | socklen_t fromlen; |
48e671d5 | 582 | fd_set *fdset; |
583 | struct sockaddr_storage from; | |
5260325f | 584 | const char *remote_ip; |
585 | int remote_port; | |
5260325f | 586 | FILE *f; |
587 | struct linger linger; | |
48e671d5 | 588 | struct addrinfo *ai; |
589 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
590 | int listen_sock, maxfd; | |
089fbbd2 | 591 | int startup_p[2]; |
592 | int startups = 0; | |
aeaa3d9e | 593 | Key *key; |
59c97189 | 594 | int ret, key_used = 0; |
5260325f | 595 | |
260d427b | 596 | __progname = get_progname(av[0]); |
264dce47 | 597 | init_rng(); |
598 | ||
1fe6a48f | 599 | /* Save argv. */ |
4d33e531 | 600 | saved_argc = ac; |
5260325f | 601 | saved_argv = av; |
5260325f | 602 | |
603 | /* Initialize configuration options to their default values. */ | |
604 | initialize_server_options(&options); | |
605 | ||
606 | /* Parse command-line arguments. */ | |
2717fa0f | 607 | while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:u:o:dDeiqtQ46")) != -1) { |
5260325f | 608 | switch (opt) { |
48e671d5 | 609 | case '4': |
610 | IPv4or6 = AF_INET; | |
611 | break; | |
612 | case '6': | |
613 | IPv4or6 = AF_INET6; | |
614 | break; | |
5260325f | 615 | case 'f': |
616 | config_file_name = optarg; | |
617 | break; | |
618 | case 'd': | |
bcbf86ec | 619 | if (0 == debug_flag) { |
620 | debug_flag = 1; | |
621 | options.log_level = SYSLOG_LEVEL_DEBUG1; | |
622 | } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) { | |
623 | options.log_level++; | |
624 | } else { | |
625 | fprintf(stderr, "Too high debugging level.\n"); | |
626 | exit(1); | |
627 | } | |
5260325f | 628 | break; |
0b6fbf03 | 629 | case 'D': |
630 | no_daemon_flag = 1; | |
631 | break; | |
ff14faf1 | 632 | case 'e': |
633 | log_stderr = 1; | |
634 | break; | |
5260325f | 635 | case 'i': |
636 | inetd_flag = 1; | |
637 | break; | |
638 | case 'Q': | |
9bd5b720 | 639 | /* ignored */ |
5260325f | 640 | break; |
641 | case 'q': | |
642 | options.log_level = SYSLOG_LEVEL_QUIET; | |
643 | break; | |
644 | case 'b': | |
645 | options.server_key_bits = atoi(optarg); | |
646 | break; | |
647 | case 'p': | |
48e671d5 | 648 | options.ports_from_cmdline = 1; |
bcbf86ec | 649 | if (options.num_ports >= MAX_PORTS) { |
650 | fprintf(stderr, "too many ports.\n"); | |
651 | exit(1); | |
652 | } | |
2d2a2c65 | 653 | options.ports[options.num_ports++] = a2port(optarg); |
654 | if (options.ports[options.num_ports-1] == 0) { | |
655 | fprintf(stderr, "Bad port number.\n"); | |
656 | exit(1); | |
657 | } | |
5260325f | 658 | break; |
659 | case 'g': | |
e2b1fb42 | 660 | if ((options.login_grace_time = convtime(optarg)) == -1) { |
661 | fprintf(stderr, "Invalid login grace time.\n"); | |
662 | exit(1); | |
663 | } | |
5260325f | 664 | break; |
665 | case 'k': | |
e2b1fb42 | 666 | if ((options.key_regeneration_time = convtime(optarg)) == -1) { |
667 | fprintf(stderr, "Invalid key regeneration interval.\n"); | |
668 | exit(1); | |
669 | } | |
5260325f | 670 | break; |
671 | case 'h': | |
fa08c86b | 672 | if (options.num_host_key_files >= MAX_HOSTKEYS) { |
673 | fprintf(stderr, "too many host keys.\n"); | |
674 | exit(1); | |
675 | } | |
676 | options.host_key_files[options.num_host_key_files++] = optarg; | |
5260325f | 677 | break; |
678 | case 'V': | |
679 | client_version_string = optarg; | |
680 | /* only makes sense with inetd_flag, i.e. no listen() */ | |
681 | inetd_flag = 1; | |
682 | break; | |
f87f09aa | 683 | case 't': |
684 | test_flag = 1; | |
685 | break; | |
c345cf9d | 686 | case 'u': |
687 | utmp_len = atoi(optarg); | |
688 | break; | |
2717fa0f | 689 | case 'o': |
184eed6a | 690 | if (process_server_config_line(&options, optarg, |
2717fa0f | 691 | "command-line", 0) != 0) |
184eed6a | 692 | exit(1); |
2717fa0f | 693 | break; |
5260325f | 694 | case '?': |
695 | default: | |
2717fa0f | 696 | usage(); |
697 | break; | |
5260325f | 698 | } |
699 | } | |
1a92bd7e | 700 | SSLeay_add_all_algorithms(); |
5e4a7219 | 701 | channel_set_af(IPv4or6); |
5260325f | 702 | |
48e671d5 | 703 | /* |
704 | * Force logging to stderr until we have loaded the private host | |
705 | * key (unless started from inetd) | |
706 | */ | |
1fe6a48f | 707 | log_init(__progname, |
59c97189 | 708 | options.log_level == -1 ? SYSLOG_LEVEL_INFO : options.log_level, |
48e671d5 | 709 | options.log_facility == -1 ? SYSLOG_FACILITY_AUTH : options.log_facility, |
9bd5b720 | 710 | !inetd_flag); |
48e671d5 | 711 | |
1a23ac2c | 712 | #ifdef _CRAY |
713 | /* Cray can define user privs drop all prives now! | |
714 | * Not needed on PRIV_SU systems! | |
715 | */ | |
716 | drop_cray_privs(); | |
717 | #endif | |
718 | ||
e339aa53 | 719 | seed_rng(); |
720 | ||
5260325f | 721 | /* Read server configuration options from the configuration file. */ |
722 | read_server_config(&options, config_file_name); | |
723 | ||
724 | /* Fill in default values for those options not explicitly set. */ | |
725 | fill_default_server_options(&options); | |
726 | ||
5260325f | 727 | /* Check that there are no remaining arguments. */ |
728 | if (optind < ac) { | |
729 | fprintf(stderr, "Extra argument %s.\n", av[optind]); | |
730 | exit(1); | |
8efc0c15 | 731 | } |
5260325f | 732 | |
733 | debug("sshd version %.100s", SSH_VERSION); | |
734 | ||
fa08c86b | 735 | /* load private host keys */ |
736 | sensitive_data.host_keys = xmalloc(options.num_host_key_files*sizeof(Key*)); | |
184eed6a | 737 | for (i = 0; i < options.num_host_key_files; i++) |
1e3b8b07 | 738 | sensitive_data.host_keys[i] = NULL; |
fa08c86b | 739 | sensitive_data.server_key = NULL; |
740 | sensitive_data.ssh1_host_key = NULL; | |
741 | sensitive_data.have_ssh1_key = 0; | |
742 | sensitive_data.have_ssh2_key = 0; | |
a306f2dd | 743 | |
184eed6a | 744 | for (i = 0; i < options.num_host_key_files; i++) { |
aeaa3d9e | 745 | key = key_load_private(options.host_key_files[i], "", NULL); |
746 | sensitive_data.host_keys[i] = key; | |
fa08c86b | 747 | if (key == NULL) { |
58cfa257 | 748 | error("Could not load host key: %s", |
749 | options.host_key_files[i]); | |
aeaa3d9e | 750 | sensitive_data.host_keys[i] = NULL; |
fa08c86b | 751 | continue; |
a306f2dd | 752 | } |
6aacefa7 | 753 | switch (key->type) { |
fa08c86b | 754 | case KEY_RSA1: |
755 | sensitive_data.ssh1_host_key = key; | |
756 | sensitive_data.have_ssh1_key = 1; | |
757 | break; | |
758 | case KEY_RSA: | |
759 | case KEY_DSA: | |
760 | sensitive_data.have_ssh2_key = 1; | |
761 | break; | |
a306f2dd | 762 | } |
aeaa3d9e | 763 | debug("private host key: #%d type %d %s", i, key->type, |
764 | key_type(key)); | |
fa08c86b | 765 | } |
766 | if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) { | |
767 | log("Disabling protocol version 1. Could not load host key"); | |
768 | options.protocol &= ~SSH_PROTO_1; | |
769 | } | |
770 | if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) { | |
771 | log("Disabling protocol version 2. Could not load host key"); | |
772 | options.protocol &= ~SSH_PROTO_2; | |
a306f2dd | 773 | } |
6a416424 | 774 | if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) { |
54b974dc | 775 | log("sshd: no hostkeys available -- exiting."); |
5260325f | 776 | exit(1); |
777 | } | |
5260325f | 778 | |
a306f2dd | 779 | /* Check certain values for sanity. */ |
780 | if (options.protocol & SSH_PROTO_1) { | |
781 | if (options.server_key_bits < 512 || | |
782 | options.server_key_bits > 32768) { | |
783 | fprintf(stderr, "Bad server key size.\n"); | |
784 | exit(1); | |
785 | } | |
786 | /* | |
787 | * Check that server and host key lengths differ sufficiently. This | |
788 | * is necessary to make double encryption work with rsaref. Oh, I | |
789 | * hate software patents. I dont know if this can go? Niels | |
790 | */ | |
791 | if (options.server_key_bits > | |
fa08c86b | 792 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) - SSH_KEY_BITS_RESERVED && |
a306f2dd | 793 | options.server_key_bits < |
fa08c86b | 794 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) { |
a306f2dd | 795 | options.server_key_bits = |
fa08c86b | 796 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED; |
a306f2dd | 797 | debug("Forcing server key to %d bits to make it differ from host key.", |
798 | options.server_key_bits); | |
799 | } | |
800 | } | |
801 | ||
f87f09aa | 802 | /* Configuration looks good, so exit if in test mode. */ |
803 | if (test_flag) | |
804 | exit(0); | |
805 | ||
77bb0bca | 806 | #ifdef HAVE_SCO_PROTECTED_PW |
807 | (void) set_auth_parameters(ac, av); | |
808 | #endif | |
809 | ||
a306f2dd | 810 | /* Initialize the log (it is reinitialized below in case we forked). */ |
5260325f | 811 | if (debug_flag && !inetd_flag) |
812 | log_stderr = 1; | |
1fe6a48f | 813 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
5260325f | 814 | |
a306f2dd | 815 | /* |
816 | * If not in debugging mode, and not started from inetd, disconnect | |
817 | * from the controlling terminal, and fork. The original process | |
818 | * exits. | |
819 | */ | |
0b6fbf03 | 820 | if (!(debug_flag || inetd_flag || no_daemon_flag)) { |
8efc0c15 | 821 | #ifdef TIOCNOTTY |
5260325f | 822 | int fd; |
8efc0c15 | 823 | #endif /* TIOCNOTTY */ |
5260325f | 824 | if (daemon(0, 0) < 0) |
825 | fatal("daemon() failed: %.200s", strerror(errno)); | |
826 | ||
827 | /* Disconnect from the controlling tty. */ | |
8efc0c15 | 828 | #ifdef TIOCNOTTY |
5ca51e19 | 829 | fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); |
5260325f | 830 | if (fd >= 0) { |
831 | (void) ioctl(fd, TIOCNOTTY, NULL); | |
832 | close(fd); | |
833 | } | |
8efc0c15 | 834 | #endif /* TIOCNOTTY */ |
8efc0c15 | 835 | } |
5260325f | 836 | /* Reinitialize the log (because of the fork above). */ |
1fe6a48f | 837 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
5260325f | 838 | |
5260325f | 839 | /* Initialize the random number generator. */ |
840 | arc4random_stir(); | |
841 | ||
842 | /* Chdir to the root directory so that the current disk can be | |
843 | unmounted if desired. */ | |
844 | chdir("/"); | |
184eed6a | 845 | |
1d3c30db | 846 | /* ignore SIGPIPE */ |
847 | signal(SIGPIPE, SIG_IGN); | |
5260325f | 848 | |
5260325f | 849 | /* Start listening for a socket, unless started from inetd. */ |
850 | if (inetd_flag) { | |
ec1f12d3 | 851 | int s1; |
5260325f | 852 | s1 = dup(0); /* Make sure descriptors 0, 1, and 2 are in use. */ |
ec1f12d3 | 853 | dup(s1); |
5260325f | 854 | sock_in = dup(0); |
855 | sock_out = dup(1); | |
4c8722d9 | 856 | startup_pipe = -1; |
a306f2dd | 857 | /* |
858 | * We intentionally do not close the descriptors 0, 1, and 2 | |
859 | * as our code for setting the descriptors won\'t work if | |
860 | * ttyfd happens to be one of those. | |
861 | */ | |
5260325f | 862 | debug("inetd sockets after dupping: %d, %d", sock_in, sock_out); |
fa08c86b | 863 | if (options.protocol & SSH_PROTO_1) |
cb7bd922 | 864 | generate_ephemeral_server_key(); |
5260325f | 865 | } else { |
48e671d5 | 866 | for (ai = options.listen_addrs; ai; ai = ai->ai_next) { |
867 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
868 | continue; | |
869 | if (num_listen_socks >= MAX_LISTEN_SOCKS) | |
870 | fatal("Too many listen sockets. " | |
871 | "Enlarge MAX_LISTEN_SOCKS"); | |
872 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, | |
873 | ntop, sizeof(ntop), strport, sizeof(strport), | |
874 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
875 | error("getnameinfo failed"); | |
876 | continue; | |
877 | } | |
878 | /* Create socket for listening. */ | |
879 | listen_sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
880 | if (listen_sock < 0) { | |
881 | /* kernel may not support ipv6 */ | |
882 | verbose("socket: %.100s", strerror(errno)); | |
883 | continue; | |
884 | } | |
885 | if (fcntl(listen_sock, F_SETFL, O_NONBLOCK) < 0) { | |
886 | error("listen_sock O_NONBLOCK: %s", strerror(errno)); | |
887 | close(listen_sock); | |
888 | continue; | |
889 | } | |
890 | /* | |
891 | * Set socket options. We try to make the port | |
892 | * reusable and have it close as fast as possible | |
893 | * without waiting in unnecessary wait states on | |
894 | * close. | |
895 | */ | |
896 | setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, | |
897 | (void *) &on, sizeof(on)); | |
898 | linger.l_onoff = 1; | |
899 | linger.l_linger = 5; | |
900 | setsockopt(listen_sock, SOL_SOCKET, SO_LINGER, | |
901 | (void *) &linger, sizeof(linger)); | |
902 | ||
903 | debug("Bind to port %s on %s.", strport, ntop); | |
904 | ||
905 | /* Bind the socket to the desired port. */ | |
32ced054 | 906 | if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) { |
907 | if (!ai->ai_next) | |
908 | error("Bind to port %s on %s failed: %.200s.", | |
909 | strport, ntop, strerror(errno)); | |
48e671d5 | 910 | close(listen_sock); |
911 | continue; | |
912 | } | |
913 | listen_socks[num_listen_socks] = listen_sock; | |
914 | num_listen_socks++; | |
915 | ||
916 | /* Start listening on the port. */ | |
917 | log("Server listening on %s port %s.", ntop, strport); | |
918 | if (listen(listen_sock, 5) < 0) | |
919 | fatal("listen: %.100s", strerror(errno)); | |
920 | ||
5260325f | 921 | } |
48e671d5 | 922 | freeaddrinfo(options.listen_addrs); |
923 | ||
924 | if (!num_listen_socks) | |
925 | fatal("Cannot bind any address."); | |
926 | ||
3aca00a3 | 927 | if (options.protocol & SSH_PROTO_1) |
928 | generate_ephemeral_server_key(); | |
929 | ||
930 | /* | |
931 | * Arrange to restart on SIGHUP. The handler needs | |
932 | * listen_sock. | |
933 | */ | |
934 | signal(SIGHUP, sighup_handler); | |
935 | ||
936 | signal(SIGTERM, sigterm_handler); | |
937 | signal(SIGQUIT, sigterm_handler); | |
938 | ||
939 | /* Arrange SIGCHLD to be caught. */ | |
940 | signal(SIGCHLD, main_sigchld_handler); | |
941 | ||
942 | /* Write out the pid file after the sigterm handler is setup */ | |
5260325f | 943 | if (!debug_flag) { |
aa3378df | 944 | /* |
97fb6912 | 945 | * Record our pid in /var/run/sshd.pid to make it |
946 | * easier to kill the correct sshd. We don't want to | |
947 | * do this before the bind above because the bind will | |
aa3378df | 948 | * fail if there already is a daemon, and this will |
949 | * overwrite any old pid in the file. | |
950 | */ | |
3c62e7eb | 951 | f = fopen(options.pid_file, "wb"); |
5260325f | 952 | if (f) { |
1e3b8b07 | 953 | fprintf(f, "%u\n", (u_int) getpid()); |
5260325f | 954 | fclose(f); |
955 | } | |
8efc0c15 | 956 | } |
5260325f | 957 | |
48e671d5 | 958 | /* setup fd set for listen */ |
089fbbd2 | 959 | fdset = NULL; |
48e671d5 | 960 | maxfd = 0; |
961 | for (i = 0; i < num_listen_socks; i++) | |
962 | if (listen_socks[i] > maxfd) | |
963 | maxfd = listen_socks[i]; | |
089fbbd2 | 964 | /* pipes connected to unauthenticated childs */ |
965 | startup_pipes = xmalloc(options.max_startups * sizeof(int)); | |
966 | for (i = 0; i < options.max_startups; i++) | |
967 | startup_pipes[i] = -1; | |
48e671d5 | 968 | |
aa3378df | 969 | /* |
970 | * Stay listening for connections until the system crashes or | |
971 | * the daemon is killed with a signal. | |
972 | */ | |
5260325f | 973 | for (;;) { |
974 | if (received_sighup) | |
975 | sighup_restart(); | |
089fbbd2 | 976 | if (fdset != NULL) |
977 | xfree(fdset); | |
b5c334cc | 978 | fdsetsz = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask); |
089fbbd2 | 979 | fdset = (fd_set *)xmalloc(fdsetsz); |
48e671d5 | 980 | memset(fdset, 0, fdsetsz); |
089fbbd2 | 981 | |
48e671d5 | 982 | for (i = 0; i < num_listen_socks; i++) |
983 | FD_SET(listen_socks[i], fdset); | |
089fbbd2 | 984 | for (i = 0; i < options.max_startups; i++) |
985 | if (startup_pipes[i] != -1) | |
986 | FD_SET(startup_pipes[i], fdset); | |
987 | ||
988 | /* Wait in select until there is a connection. */ | |
59c97189 | 989 | ret = select(maxfd+1, fdset, NULL, NULL, NULL); |
990 | if (ret < 0 && errno != EINTR) | |
991 | error("select: %.100s", strerror(errno)); | |
c9130033 | 992 | if (received_sigterm) { |
993 | log("Received signal %d; terminating.", | |
010f9726 | 994 | (int) received_sigterm); |
c9130033 | 995 | close_listen_socks(); |
996 | unlink(options.pid_file); | |
997 | exit(255); | |
998 | } | |
59c97189 | 999 | if (key_used && key_do_regen) { |
cb7bd922 | 1000 | generate_ephemeral_server_key(); |
59c97189 | 1001 | key_used = 0; |
1002 | key_do_regen = 0; | |
48e671d5 | 1003 | } |
59c97189 | 1004 | if (ret < 0) |
1005 | continue; | |
1006 | ||
089fbbd2 | 1007 | for (i = 0; i < options.max_startups; i++) |
1008 | if (startup_pipes[i] != -1 && | |
1009 | FD_ISSET(startup_pipes[i], fdset)) { | |
1010 | /* | |
1011 | * the read end of the pipe is ready | |
1012 | * if the child has closed the pipe | |
8abcdba4 | 1013 | * after successful authentication |
089fbbd2 | 1014 | * or if the child has died |
1015 | */ | |
1016 | close(startup_pipes[i]); | |
1017 | startup_pipes[i] = -1; | |
1018 | startups--; | |
1019 | } | |
48e671d5 | 1020 | for (i = 0; i < num_listen_socks; i++) { |
1021 | if (!FD_ISSET(listen_socks[i], fdset)) | |
5260325f | 1022 | continue; |
089fbbd2 | 1023 | fromlen = sizeof(from); |
1024 | newsock = accept(listen_socks[i], (struct sockaddr *)&from, | |
1025 | &fromlen); | |
1026 | if (newsock < 0) { | |
1027 | if (errno != EINTR && errno != EWOULDBLOCK) | |
1028 | error("accept: %.100s", strerror(errno)); | |
1029 | continue; | |
1030 | } | |
1031 | if (fcntl(newsock, F_SETFL, 0) < 0) { | |
1032 | error("newsock del O_NONBLOCK: %s", strerror(errno)); | |
5e8948af | 1033 | close(newsock); |
089fbbd2 | 1034 | continue; |
1035 | } | |
c345cf9d | 1036 | if (drop_connection(startups) == 1) { |
1037 | debug("drop connection #%d", startups); | |
089fbbd2 | 1038 | close(newsock); |
1039 | continue; | |
1040 | } | |
1041 | if (pipe(startup_p) == -1) { | |
1042 | close(newsock); | |
1043 | continue; | |
1044 | } | |
1045 | ||
1046 | for (j = 0; j < options.max_startups; j++) | |
1047 | if (startup_pipes[j] == -1) { | |
1048 | startup_pipes[j] = startup_p[0]; | |
1049 | if (maxfd < startup_p[0]) | |
1050 | maxfd = startup_p[0]; | |
1051 | startups++; | |
1052 | break; | |
1053 | } | |
2b87da3b | 1054 | |
aa3378df | 1055 | /* |
089fbbd2 | 1056 | * Got connection. Fork a child to handle it, unless |
1057 | * we are in debugging mode. | |
aa3378df | 1058 | */ |
089fbbd2 | 1059 | if (debug_flag) { |
aa3378df | 1060 | /* |
089fbbd2 | 1061 | * In debugging mode. Close the listening |
1062 | * socket, and start processing the | |
1063 | * connection without forking. | |
aa3378df | 1064 | */ |
089fbbd2 | 1065 | debug("Server will not fork when running in debugging mode."); |
48e671d5 | 1066 | close_listen_socks(); |
5260325f | 1067 | sock_in = newsock; |
1068 | sock_out = newsock; | |
5540ea9b | 1069 | startup_pipe = -1; |
3f7a7e4a | 1070 | pid = getpid(); |
5260325f | 1071 | break; |
089fbbd2 | 1072 | } else { |
1073 | /* | |
1074 | * Normal production daemon. Fork, and have | |
1075 | * the child process the connection. The | |
1076 | * parent continues listening. | |
1077 | */ | |
1078 | if ((pid = fork()) == 0) { | |
1079 | /* | |
1080 | * Child. Close the listening and max_startup | |
1081 | * sockets. Start using the accepted socket. | |
1082 | * Reinitialize logging (since our pid has | |
1083 | * changed). We break out of the loop to handle | |
1084 | * the connection. | |
1085 | */ | |
1086 | startup_pipe = startup_p[1]; | |
7ace8c3b | 1087 | close_startup_pipes(); |
089fbbd2 | 1088 | close_listen_socks(); |
1089 | sock_in = newsock; | |
1090 | sock_out = newsock; | |
1fe6a48f | 1091 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
089fbbd2 | 1092 | break; |
1093 | } | |
5260325f | 1094 | } |
5260325f | 1095 | |
089fbbd2 | 1096 | /* Parent. Stay in the loop. */ |
1097 | if (pid < 0) | |
1098 | error("fork: %.100s", strerror(errno)); | |
1099 | else | |
1100 | debug("Forked child %d.", pid); | |
5260325f | 1101 | |
089fbbd2 | 1102 | close(startup_p[1]); |
5260325f | 1103 | |
089fbbd2 | 1104 | /* Mark that the key has been used (it was "given" to the child). */ |
59c97189 | 1105 | if ((options.protocol & SSH_PROTO_1) && |
1106 | key_used == 0) { | |
1107 | /* Schedule server key regeneration alarm. */ | |
1108 | signal(SIGALRM, key_regeneration_alarm); | |
1109 | alarm(options.key_regeneration_time); | |
1110 | key_used = 1; | |
1111 | } | |
5260325f | 1112 | |
089fbbd2 | 1113 | arc4random_stir(); |
1114 | ||
1115 | /* Close the new socket (the child is now taking care of it). */ | |
1116 | close(newsock); | |
1117 | } | |
48e671d5 | 1118 | /* child process check (or debug mode) */ |
1119 | if (num_listen_socks < 0) | |
1120 | break; | |
5260325f | 1121 | } |
1122 | } | |
8efc0c15 | 1123 | |
5260325f | 1124 | /* This is the child processing a new connection. */ |
1125 | ||
aa3378df | 1126 | /* |
1127 | * Disable the key regeneration alarm. We will not regenerate the | |
1128 | * key since we are no longer in a position to give it to anyone. We | |
1129 | * will not restart on SIGHUP since it no longer makes sense. | |
1130 | */ | |
5260325f | 1131 | alarm(0); |
1132 | signal(SIGALRM, SIG_DFL); | |
1133 | signal(SIGHUP, SIG_DFL); | |
1134 | signal(SIGTERM, SIG_DFL); | |
1135 | signal(SIGQUIT, SIG_DFL); | |
1136 | signal(SIGCHLD, SIG_DFL); | |
9aaf9be4 | 1137 | signal(SIGINT, SIG_DFL); |
5260325f | 1138 | |
aa3378df | 1139 | /* |
1140 | * Set socket options for the connection. We want the socket to | |
1141 | * close as fast as possible without waiting for anything. If the | |
1142 | * connection is not a socket, these will do nothing. | |
1143 | */ | |
1144 | /* setsockopt(sock_in, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); */ | |
5260325f | 1145 | linger.l_onoff = 1; |
1146 | linger.l_linger = 5; | |
1147 | setsockopt(sock_in, SOL_SOCKET, SO_LINGER, (void *) &linger, sizeof(linger)); | |
1148 | ||
b5c334cc | 1149 | /* Set keepalives if requested. */ |
1150 | if (options.keepalives && | |
1151 | setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, (void *)&on, | |
1152 | sizeof(on)) < 0) | |
1153 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); | |
1154 | ||
aa3378df | 1155 | /* |
1156 | * Register our connection. This turns encryption off because we do | |
1157 | * not have a key. | |
1158 | */ | |
5260325f | 1159 | packet_set_connection(sock_in, sock_out); |
1160 | ||
1161 | remote_port = get_remote_port(); | |
1162 | remote_ip = get_remote_ipaddr(); | |
1163 | ||
5260325f | 1164 | #ifdef LIBWRAP |
ac28afd8 | 1165 | /* Check whether logins are denied from this host. */ |
5260325f | 1166 | { |
1167 | struct request_info req; | |
8efc0c15 | 1168 | |
8fbc356d | 1169 | request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0); |
5260325f | 1170 | fromhost(&req); |
8efc0c15 | 1171 | |
5260325f | 1172 | if (!hosts_access(&req)) { |
ac28afd8 | 1173 | debug("Connection refused by tcp wrapper"); |
563834bb | 1174 | refuse(&req); |
ac28afd8 | 1175 | /* NOTREACHED */ |
1176 | fatal("libwrap refuse returns"); | |
5260325f | 1177 | } |
8efc0c15 | 1178 | } |
48e671d5 | 1179 | #endif /* LIBWRAP */ |
ac28afd8 | 1180 | |
5260325f | 1181 | /* Log the connection. */ |
1182 | verbose("Connection from %.500s port %d", remote_ip, remote_port); | |
8efc0c15 | 1183 | |
aa3378df | 1184 | /* |
1185 | * We don\'t want to listen forever unless the other side | |
1186 | * successfully authenticates itself. So we set up an alarm which is | |
1187 | * cleared after successful authentication. A limit of zero | |
1188 | * indicates no limit. Note that we don\'t set the alarm in debugging | |
1189 | * mode; it is just annoying to have the server exit just when you | |
1190 | * are about to discover the bug. | |
1191 | */ | |
5260325f | 1192 | signal(SIGALRM, grace_alarm_handler); |
1193 | if (!debug_flag) | |
1194 | alarm(options.login_grace_time); | |
1195 | ||
7368a6c8 | 1196 | sshd_exchange_identification(sock_in, sock_out); |
aa3378df | 1197 | /* |
6ffc9c88 | 1198 | * Check that the connection comes from a privileged port. |
1199 | * Rhosts-Authentication only makes sense from priviledged | |
aa3378df | 1200 | * programs. Of course, if the intruder has root access on his local |
1201 | * machine, he can connect from any port. So do not use these | |
1202 | * authentication methods from machines that you do not trust. | |
1203 | */ | |
5260325f | 1204 | if (remote_port >= IPPORT_RESERVED || |
1205 | remote_port < IPPORT_RESERVED / 2) { | |
6ffc9c88 | 1206 | debug("Rhosts Authentication disabled, " |
9ae3f727 | 1207 | "originating port %d not trusted.", remote_port); |
5260325f | 1208 | options.rhosts_authentication = 0; |
5260325f | 1209 | } |
ced49be2 | 1210 | #if defined(KRB4) && !defined(KRB5) |
48e671d5 | 1211 | if (!packet_connection_is_ipv4() && |
1212 | options.kerberos_authentication) { | |
1213 | debug("Kerberos Authentication disabled, only available for IPv4."); | |
1214 | options.kerberos_authentication = 0; | |
1215 | } | |
ced49be2 | 1216 | #endif /* KRB4 && !KRB5 */ |
abf1f107 | 1217 | #ifdef AFS |
1218 | /* If machine has AFS, set process authentication group. */ | |
1219 | if (k_hasafs()) { | |
1220 | k_setpag(); | |
1221 | k_unlog(); | |
1222 | } | |
1223 | #endif /* AFS */ | |
48e671d5 | 1224 | |
5260325f | 1225 | packet_set_nonblocking(); |
1226 | ||
7b2ea3a1 | 1227 | /* perform the key exchange */ |
7b2ea3a1 | 1228 | /* authenticate user and start session */ |
e78a59f5 | 1229 | if (compat20) { |
1230 | do_ssh2_kex(); | |
1231 | do_authentication2(); | |
1232 | } else { | |
1233 | do_ssh1_kex(); | |
1234 | do_authentication(); | |
1235 | } | |
5260325f | 1236 | /* The connection has been terminated. */ |
1237 | verbose("Closing connection to %.100s", remote_ip); | |
8efc0c15 | 1238 | |
d94aa2ae | 1239 | #ifdef USE_PAM |
a5c9cd31 | 1240 | finish_pam(); |
d94aa2ae | 1241 | #endif /* USE_PAM */ |
8efc0c15 | 1242 | |
5260325f | 1243 | packet_close(); |
1244 | exit(0); | |
1245 | } | |
8efc0c15 | 1246 | |
5260325f | 1247 | /* |
7b2ea3a1 | 1248 | * SSH1 key exchange |
5260325f | 1249 | */ |
396c147e | 1250 | static void |
1e3b8b07 | 1251 | do_ssh1_kex(void) |
8efc0c15 | 1252 | { |
5260325f | 1253 | int i, len; |
7b2ea3a1 | 1254 | int plen, slen; |
46aa2d1f | 1255 | int rsafail = 0; |
5260325f | 1256 | BIGNUM *session_key_int; |
1e3b8b07 | 1257 | u_char session_key[SSH_SESSION_KEY_LENGTH]; |
1258 | u_char cookie[8]; | |
1259 | u_int cipher_type, auth_mask, protocol_flags; | |
5260325f | 1260 | u_int32_t rand = 0; |
1261 | ||
aa3378df | 1262 | /* |
1263 | * Generate check bytes that the client must send back in the user | |
1264 | * packet in order for it to be accepted; this is used to defy ip | |
1265 | * spoofing attacks. Note that this only works against somebody | |
1266 | * doing IP spoofing from a remote machine; any machine on the local | |
1267 | * network can still see outgoing packets and catch the random | |
1268 | * cookie. This only affects rhosts authentication, and this is one | |
1269 | * of the reasons why it is inherently insecure. | |
1270 | */ | |
5260325f | 1271 | for (i = 0; i < 8; i++) { |
1272 | if (i % 4 == 0) | |
1273 | rand = arc4random(); | |
7b2ea3a1 | 1274 | cookie[i] = rand & 0xff; |
5260325f | 1275 | rand >>= 8; |
1276 | } | |
1277 | ||
aa3378df | 1278 | /* |
1279 | * Send our public key. We include in the packet 64 bits of random | |
1280 | * data that must be matched in the reply in order to prevent IP | |
1281 | * spoofing. | |
1282 | */ | |
5260325f | 1283 | packet_start(SSH_SMSG_PUBLIC_KEY); |
1284 | for (i = 0; i < 8; i++) | |
7b2ea3a1 | 1285 | packet_put_char(cookie[i]); |
5260325f | 1286 | |
1287 | /* Store our public server RSA key. */ | |
fa08c86b | 1288 | packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n)); |
1289 | packet_put_bignum(sensitive_data.server_key->rsa->e); | |
1290 | packet_put_bignum(sensitive_data.server_key->rsa->n); | |
5260325f | 1291 | |
1292 | /* Store our public host RSA key. */ | |
fa08c86b | 1293 | packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); |
1294 | packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e); | |
1295 | packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n); | |
5260325f | 1296 | |
1297 | /* Put protocol flags. */ | |
1298 | packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN); | |
1299 | ||
1300 | /* Declare which ciphers we support. */ | |
94ec8c6b | 1301 | packet_put_int(cipher_mask_ssh1(0)); |
5260325f | 1302 | |
1303 | /* Declare supported authentication types. */ | |
1304 | auth_mask = 0; | |
1305 | if (options.rhosts_authentication) | |
1306 | auth_mask |= 1 << SSH_AUTH_RHOSTS; | |
1307 | if (options.rhosts_rsa_authentication) | |
1308 | auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA; | |
1309 | if (options.rsa_authentication) | |
1310 | auth_mask |= 1 << SSH_AUTH_RSA; | |
ced49be2 | 1311 | #if defined(KRB4) || defined(KRB5) |
5260325f | 1312 | if (options.kerberos_authentication) |
1313 | auth_mask |= 1 << SSH_AUTH_KERBEROS; | |
8efc0c15 | 1314 | #endif |
ced49be2 | 1315 | #if defined(AFS) || defined(KRB5) |
5260325f | 1316 | if (options.kerberos_tgt_passing) |
1317 | auth_mask |= 1 << SSH_PASS_KERBEROS_TGT; | |
ced49be2 | 1318 | #endif |
1319 | #ifdef AFS | |
5260325f | 1320 | if (options.afs_token_passing) |
1321 | auth_mask |= 1 << SSH_PASS_AFS_TOKEN; | |
8efc0c15 | 1322 | #endif |
5ba55ada | 1323 | if (options.challenge_response_authentication == 1) |
5260325f | 1324 | auth_mask |= 1 << SSH_AUTH_TIS; |
5260325f | 1325 | if (options.password_authentication) |
1326 | auth_mask |= 1 << SSH_AUTH_PASSWORD; | |
1327 | packet_put_int(auth_mask); | |
1328 | ||
1329 | /* Send the packet and wait for it to be sent. */ | |
1330 | packet_send(); | |
1331 | packet_write_wait(); | |
1332 | ||
fa08c86b | 1333 | debug("Sent %d bit server key and %d bit host key.", |
1334 | BN_num_bits(sensitive_data.server_key->rsa->n), | |
1335 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); | |
5260325f | 1336 | |
1337 | /* Read clients reply (cipher type and session key). */ | |
1338 | packet_read_expect(&plen, SSH_CMSG_SESSION_KEY); | |
1339 | ||
2d86a6cc | 1340 | /* Get cipher type and check whether we accept this. */ |
5260325f | 1341 | cipher_type = packet_get_char(); |
1342 | ||
94ec8c6b | 1343 | if (!(cipher_mask_ssh1(0) & (1 << cipher_type))) |
2d86a6cc | 1344 | packet_disconnect("Warning: client selects unsupported cipher."); |
1345 | ||
5260325f | 1346 | /* Get check bytes from the packet. These must match those we |
1347 | sent earlier with the public key packet. */ | |
1348 | for (i = 0; i < 8; i++) | |
7b2ea3a1 | 1349 | if (cookie[i] != packet_get_char()) |
5260325f | 1350 | packet_disconnect("IP Spoofing check bytes do not match."); |
1351 | ||
1352 | debug("Encryption type: %.200s", cipher_name(cipher_type)); | |
1353 | ||
1354 | /* Get the encrypted integer. */ | |
b775c6f2 | 1355 | if ((session_key_int = BN_new()) == NULL) |
1356 | fatal("do_ssh1_kex: BN_new failed"); | |
5260325f | 1357 | packet_get_bignum(session_key_int, &slen); |
1358 | ||
5260325f | 1359 | protocol_flags = packet_get_int(); |
1360 | packet_set_protocol_flags(protocol_flags); | |
a8a21a53 | 1361 | packet_done(); |
5260325f | 1362 | |
aa3378df | 1363 | /* |
1364 | * Decrypt it using our private server key and private host key (key | |
1365 | * with larger modulus first). | |
1366 | */ | |
fa08c86b | 1367 | if (BN_cmp(sensitive_data.server_key->rsa->n, sensitive_data.ssh1_host_key->rsa->n) > 0) { |
46aa2d1f | 1368 | /* Server key has bigger modulus. */ |
fa08c86b | 1369 | if (BN_num_bits(sensitive_data.server_key->rsa->n) < |
1370 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) { | |
1371 | fatal("do_connection: %s: server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d", | |
1372 | get_remote_ipaddr(), | |
1373 | BN_num_bits(sensitive_data.server_key->rsa->n), | |
1374 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), | |
1375 | SSH_KEY_BITS_RESERVED); | |
5260325f | 1376 | } |
46aa2d1f | 1377 | if (rsa_private_decrypt(session_key_int, session_key_int, |
1378 | sensitive_data.server_key->rsa) <= 0) | |
1379 | rsafail++; | |
1380 | if (rsa_private_decrypt(session_key_int, session_key_int, | |
1381 | sensitive_data.ssh1_host_key->rsa) <= 0) | |
1382 | rsafail++; | |
5260325f | 1383 | } else { |
1384 | /* Host key has bigger modulus (or they are equal). */ | |
fa08c86b | 1385 | if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) < |
1386 | BN_num_bits(sensitive_data.server_key->rsa->n) + SSH_KEY_BITS_RESERVED) { | |
1387 | fatal("do_connection: %s: host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d", | |
1388 | get_remote_ipaddr(), | |
1389 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), | |
1390 | BN_num_bits(sensitive_data.server_key->rsa->n), | |
1391 | SSH_KEY_BITS_RESERVED); | |
5260325f | 1392 | } |
46aa2d1f | 1393 | if (rsa_private_decrypt(session_key_int, session_key_int, |
1394 | sensitive_data.ssh1_host_key->rsa) < 0) | |
1395 | rsafail++; | |
1396 | if (rsa_private_decrypt(session_key_int, session_key_int, | |
1397 | sensitive_data.server_key->rsa) < 0) | |
1398 | rsafail++; | |
5260325f | 1399 | } |
aa3378df | 1400 | /* |
1401 | * Extract session key from the decrypted integer. The key is in the | |
1402 | * least significant 256 bits of the integer; the first byte of the | |
1403 | * key is in the highest bits. | |
1404 | */ | |
46aa2d1f | 1405 | if (!rsafail) { |
1406 | BN_mask_bits(session_key_int, sizeof(session_key) * 8); | |
1407 | len = BN_num_bytes(session_key_int); | |
1408 | if (len < 0 || len > sizeof(session_key)) { | |
1409 | error("do_connection: bad session key len from %s: " | |
5ca51e19 | 1410 | "session_key_int %d > sizeof(session_key) %lu", |
1411 | get_remote_ipaddr(), len, (u_long)sizeof(session_key)); | |
46aa2d1f | 1412 | rsafail++; |
1413 | } else { | |
1414 | memset(session_key, 0, sizeof(session_key)); | |
1415 | BN_bn2bin(session_key_int, | |
1416 | session_key + sizeof(session_key) - len); | |
00be5382 | 1417 | |
1418 | compute_session_id(session_id, cookie, | |
1419 | sensitive_data.ssh1_host_key->rsa->n, | |
1420 | sensitive_data.server_key->rsa->n); | |
1421 | /* | |
1422 | * Xor the first 16 bytes of the session key with the | |
1423 | * session id. | |
1424 | */ | |
1425 | for (i = 0; i < 16; i++) | |
1426 | session_key[i] ^= session_id[i]; | |
46aa2d1f | 1427 | } |
1428 | } | |
1429 | if (rsafail) { | |
00be5382 | 1430 | int bytes = BN_num_bytes(session_key_int); |
1431 | char *buf = xmalloc(bytes); | |
1432 | MD5_CTX md; | |
1433 | ||
46aa2d1f | 1434 | log("do_connection: generating a fake encryption key"); |
00be5382 | 1435 | BN_bn2bin(session_key_int, buf); |
1436 | MD5_Init(&md); | |
1437 | MD5_Update(&md, buf, bytes); | |
1438 | MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); | |
1439 | MD5_Final(session_key, &md); | |
1440 | MD5_Init(&md); | |
1441 | MD5_Update(&md, session_key, 16); | |
1442 | MD5_Update(&md, buf, bytes); | |
1443 | MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); | |
1444 | MD5_Final(session_key + 16, &md); | |
1445 | memset(buf, 0, bytes); | |
1446 | xfree(buf); | |
0572fe75 | 1447 | for (i = 0; i < 16; i++) |
1448 | session_id[i] = session_key[i] ^ session_key[i + 16]; | |
46aa2d1f | 1449 | } |
00be5382 | 1450 | /* Destroy the private and public keys. They will no longer be needed. */ |
1451 | destroy_sensitive_data(); | |
1452 | ||
7b2ea3a1 | 1453 | /* Destroy the decrypted integer. It is no longer needed. */ |
1454 | BN_clear_free(session_key_int); | |
1455 | ||
5260325f | 1456 | /* Set the session key. From this on all communications will be encrypted. */ |
1457 | packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type); | |
1458 | ||
1459 | /* Destroy our copy of the session key. It is no longer needed. */ | |
1460 | memset(session_key, 0, sizeof(session_key)); | |
1461 | ||
1462 | debug("Received session key; encryption turned on."); | |
1463 | ||
1464 | /* Send an acknowledgement packet. Note that this packet is sent encrypted. */ | |
1465 | packet_start(SSH_SMSG_SUCCESS); | |
1466 | packet_send(); | |
1467 | packet_write_wait(); | |
5260325f | 1468 | } |
e78a59f5 | 1469 | |
1470 | /* | |
1471 | * SSH2 key exchange: diffie-hellman-group1-sha1 | |
1472 | */ | |
396c147e | 1473 | static void |
1e3b8b07 | 1474 | do_ssh2_kex(void) |
e78a59f5 | 1475 | { |
e78a59f5 | 1476 | Kex *kex; |
e78a59f5 | 1477 | |
a8be9f80 | 1478 | if (options.ciphers != NULL) { |
6ae2364d | 1479 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
a8be9f80 | 1480 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; |
1481 | } | |
1ad64a93 | 1482 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
1483 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
1484 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
1485 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
1486 | ||
b2552997 | 1487 | if (options.macs != NULL) { |
1488 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
1489 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
1490 | } | |
fa08c86b | 1491 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types(); |
1492 | ||
7a37c112 | 1493 | /* start key exchange */ |
d8ee838b | 1494 | kex = kex_setup(myproposal); |
a5c9ffdb | 1495 | kex->server = 1; |
1496 | kex->client_version_string=client_version_string; | |
1497 | kex->server_version_string=server_version_string; | |
1498 | kex->load_host_key=&get_hostkey_by_type; | |
94ec8c6b | 1499 | |
7a37c112 | 1500 | xxx_kex = kex; |
1501 | ||
c422989b | 1502 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); |
94ec8c6b | 1503 | |
d1ac6175 | 1504 | session_id2 = kex->session_id; |
1505 | session_id2_len = kex->session_id_len; | |
1506 | ||
94ec8c6b | 1507 | #ifdef DEBUG_KEXDH |
1508 | /* send 1st encrypted/maced/compressed message */ | |
1509 | packet_start(SSH2_MSG_IGNORE); | |
1510 | packet_put_cstring("markus"); | |
1511 | packet_send(); | |
1512 | packet_write_wait(); | |
1513 | #endif | |
a5c9ffdb | 1514 | debug("KEX done"); |
e78a59f5 | 1515 | } |