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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" | |
db518d9b | 43 | RCSID("$OpenBSD: sshd.c,v 1.228 2002/02/27 21:23:13 stevesk Exp $"); |
8efc0c15 | 44 | |
42f11eb2 | 45 | #include <openssl/dh.h> |
46 | #include <openssl/bn.h> | |
436c347c | 47 | #include <openssl/md5.h> |
42f11eb2 | 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 | { | |
3469eac4 | 483 | Buffer b; |
484 | char *p; | |
fa08c86b | 485 | int i; |
3469eac4 | 486 | |
487 | buffer_init(&b); | |
184eed6a | 488 | for (i = 0; i < options.num_host_key_files; i++) { |
fa08c86b | 489 | Key *key = sensitive_data.host_keys[i]; |
490 | if (key == NULL) | |
491 | continue; | |
6aacefa7 | 492 | switch (key->type) { |
fa08c86b | 493 | case KEY_RSA: |
494 | case KEY_DSA: | |
3469eac4 | 495 | if (buffer_len(&b) > 0) |
496 | buffer_append(&b, ",", 1); | |
497 | p = key_ssh_name(key); | |
498 | buffer_append(&b, p, strlen(p)); | |
fa08c86b | 499 | break; |
500 | } | |
501 | } | |
3469eac4 | 502 | buffer_append(&b, "\0", 1); |
503 | p = xstrdup(buffer_ptr(&b)); | |
504 | buffer_free(&b); | |
505 | debug("list_hostkey_types: %s", p); | |
506 | return p; | |
fa08c86b | 507 | } |
508 | ||
396c147e | 509 | static Key * |
fa08c86b | 510 | get_hostkey_by_type(int type) |
511 | { | |
512 | int i; | |
184eed6a | 513 | for (i = 0; i < options.num_host_key_files; i++) { |
fa08c86b | 514 | Key *key = sensitive_data.host_keys[i]; |
515 | if (key != NULL && key->type == type) | |
516 | return key; | |
517 | } | |
518 | return NULL; | |
7368a6c8 | 519 | } |
520 | ||
c345cf9d | 521 | /* |
522 | * returns 1 if connection should be dropped, 0 otherwise. | |
523 | * dropping starts at connection #max_startups_begin with a probability | |
524 | * of (max_startups_rate/100). the probability increases linearly until | |
525 | * all connections are dropped for startups > max_startups | |
526 | */ | |
396c147e | 527 | static int |
c345cf9d | 528 | drop_connection(int startups) |
529 | { | |
530 | double p, r; | |
531 | ||
532 | if (startups < options.max_startups_begin) | |
533 | return 0; | |
534 | if (startups >= options.max_startups) | |
535 | return 1; | |
536 | if (options.max_startups_rate == 100) | |
537 | return 1; | |
538 | ||
539 | p = 100 - options.max_startups_rate; | |
540 | p *= startups - options.max_startups_begin; | |
541 | p /= (double) (options.max_startups - options.max_startups_begin); | |
542 | p += options.max_startups_rate; | |
543 | p /= 100.0; | |
544 | r = arc4random() / (double) UINT_MAX; | |
545 | ||
546 | debug("drop_connection: p %g, r %g", p, r); | |
547 | return (r < p) ? 1 : 0; | |
548 | } | |
549 | ||
2717fa0f | 550 | static void |
551 | usage(void) | |
552 | { | |
553 | fprintf(stderr, "sshd version %s\n", SSH_VERSION); | |
554 | fprintf(stderr, "Usage: %s [options]\n", __progname); | |
555 | fprintf(stderr, "Options:\n"); | |
556 | fprintf(stderr, " -f file Configuration file (default %s)\n", _PATH_SERVER_CONFIG_FILE); | |
557 | fprintf(stderr, " -d Debugging mode (multiple -d means more debugging)\n"); | |
558 | fprintf(stderr, " -i Started from inetd\n"); | |
559 | fprintf(stderr, " -D Do not fork into daemon mode\n"); | |
560 | fprintf(stderr, " -t Only test configuration file and keys\n"); | |
561 | fprintf(stderr, " -q Quiet (no logging)\n"); | |
562 | fprintf(stderr, " -p port Listen on the specified port (default: 22)\n"); | |
563 | fprintf(stderr, " -k seconds Regenerate server key every this many seconds (default: 3600)\n"); | |
564 | fprintf(stderr, " -g seconds Grace period for authentication (default: 600)\n"); | |
565 | fprintf(stderr, " -b bits Size of server RSA key (default: 768 bits)\n"); | |
566 | fprintf(stderr, " -h file File from which to read host key (default: %s)\n", | |
567 | _PATH_HOST_KEY_FILE); | |
568 | fprintf(stderr, " -u len Maximum hostname length for utmp recording\n"); | |
569 | fprintf(stderr, " -4 Use IPv4 only\n"); | |
570 | fprintf(stderr, " -6 Use IPv6 only\n"); | |
571 | fprintf(stderr, " -o option Process the option as if it was read from a configuration file.\n"); | |
572 | exit(1); | |
573 | } | |
574 | ||
5260325f | 575 | /* |
576 | * Main program for the daemon. | |
577 | */ | |
8efc0c15 | 578 | int |
579 | main(int ac, char **av) | |
580 | { | |
5260325f | 581 | extern char *optarg; |
582 | extern int optind; | |
089fbbd2 | 583 | int opt, sock_in = 0, sock_out = 0, newsock, j, i, fdsetsz, on = 1; |
9da5c3c9 | 584 | pid_t pid; |
48e671d5 | 585 | socklen_t fromlen; |
48e671d5 | 586 | fd_set *fdset; |
587 | struct sockaddr_storage from; | |
5260325f | 588 | const char *remote_ip; |
589 | int remote_port; | |
5260325f | 590 | FILE *f; |
591 | struct linger linger; | |
48e671d5 | 592 | struct addrinfo *ai; |
593 | char ntop[NI_MAXHOST], strport[NI_MAXSERV]; | |
594 | int listen_sock, maxfd; | |
089fbbd2 | 595 | int startup_p[2]; |
596 | int startups = 0; | |
aeaa3d9e | 597 | Key *key; |
59c97189 | 598 | int ret, key_used = 0; |
5260325f | 599 | |
260d427b | 600 | __progname = get_progname(av[0]); |
264dce47 | 601 | init_rng(); |
602 | ||
1fe6a48f | 603 | /* Save argv. */ |
4d33e531 | 604 | saved_argc = ac; |
5260325f | 605 | saved_argv = av; |
5260325f | 606 | |
607 | /* Initialize configuration options to their default values. */ | |
608 | initialize_server_options(&options); | |
609 | ||
610 | /* Parse command-line arguments. */ | |
2717fa0f | 611 | while ((opt = getopt(ac, av, "f:p:b:k:h:g:V:u:o:dDeiqtQ46")) != -1) { |
5260325f | 612 | switch (opt) { |
48e671d5 | 613 | case '4': |
614 | IPv4or6 = AF_INET; | |
615 | break; | |
616 | case '6': | |
617 | IPv4or6 = AF_INET6; | |
618 | break; | |
5260325f | 619 | case 'f': |
620 | config_file_name = optarg; | |
621 | break; | |
622 | case 'd': | |
bcbf86ec | 623 | if (0 == debug_flag) { |
624 | debug_flag = 1; | |
625 | options.log_level = SYSLOG_LEVEL_DEBUG1; | |
626 | } else if (options.log_level < SYSLOG_LEVEL_DEBUG3) { | |
627 | options.log_level++; | |
628 | } else { | |
629 | fprintf(stderr, "Too high debugging level.\n"); | |
630 | exit(1); | |
631 | } | |
5260325f | 632 | break; |
0b6fbf03 | 633 | case 'D': |
634 | no_daemon_flag = 1; | |
635 | break; | |
ff14faf1 | 636 | case 'e': |
637 | log_stderr = 1; | |
638 | break; | |
5260325f | 639 | case 'i': |
640 | inetd_flag = 1; | |
641 | break; | |
642 | case 'Q': | |
9bd5b720 | 643 | /* ignored */ |
5260325f | 644 | break; |
645 | case 'q': | |
646 | options.log_level = SYSLOG_LEVEL_QUIET; | |
647 | break; | |
648 | case 'b': | |
649 | options.server_key_bits = atoi(optarg); | |
650 | break; | |
651 | case 'p': | |
48e671d5 | 652 | options.ports_from_cmdline = 1; |
bcbf86ec | 653 | if (options.num_ports >= MAX_PORTS) { |
654 | fprintf(stderr, "too many ports.\n"); | |
655 | exit(1); | |
656 | } | |
2d2a2c65 | 657 | options.ports[options.num_ports++] = a2port(optarg); |
658 | if (options.ports[options.num_ports-1] == 0) { | |
659 | fprintf(stderr, "Bad port number.\n"); | |
660 | exit(1); | |
661 | } | |
5260325f | 662 | break; |
663 | case 'g': | |
e2b1fb42 | 664 | if ((options.login_grace_time = convtime(optarg)) == -1) { |
665 | fprintf(stderr, "Invalid login grace time.\n"); | |
666 | exit(1); | |
667 | } | |
5260325f | 668 | break; |
669 | case 'k': | |
e2b1fb42 | 670 | if ((options.key_regeneration_time = convtime(optarg)) == -1) { |
671 | fprintf(stderr, "Invalid key regeneration interval.\n"); | |
672 | exit(1); | |
673 | } | |
5260325f | 674 | break; |
675 | case 'h': | |
fa08c86b | 676 | if (options.num_host_key_files >= MAX_HOSTKEYS) { |
677 | fprintf(stderr, "too many host keys.\n"); | |
678 | exit(1); | |
679 | } | |
680 | options.host_key_files[options.num_host_key_files++] = optarg; | |
5260325f | 681 | break; |
682 | case 'V': | |
683 | client_version_string = optarg; | |
684 | /* only makes sense with inetd_flag, i.e. no listen() */ | |
685 | inetd_flag = 1; | |
686 | break; | |
f87f09aa | 687 | case 't': |
688 | test_flag = 1; | |
689 | break; | |
c345cf9d | 690 | case 'u': |
691 | utmp_len = atoi(optarg); | |
692 | break; | |
2717fa0f | 693 | case 'o': |
184eed6a | 694 | if (process_server_config_line(&options, optarg, |
2717fa0f | 695 | "command-line", 0) != 0) |
184eed6a | 696 | exit(1); |
2717fa0f | 697 | break; |
5260325f | 698 | case '?': |
699 | default: | |
2717fa0f | 700 | usage(); |
701 | break; | |
5260325f | 702 | } |
703 | } | |
1a92bd7e | 704 | SSLeay_add_all_algorithms(); |
5e4a7219 | 705 | channel_set_af(IPv4or6); |
5260325f | 706 | |
48e671d5 | 707 | /* |
708 | * Force logging to stderr until we have loaded the private host | |
709 | * key (unless started from inetd) | |
710 | */ | |
1fe6a48f | 711 | log_init(__progname, |
980c9344 | 712 | options.log_level == SYSLOG_LEVEL_NOT_SET ? |
713 | SYSLOG_LEVEL_INFO : options.log_level, | |
714 | options.log_facility == SYSLOG_FACILITY_NOT_SET ? | |
715 | SYSLOG_FACILITY_AUTH : options.log_facility, | |
9bd5b720 | 716 | !inetd_flag); |
48e671d5 | 717 | |
1a23ac2c | 718 | #ifdef _CRAY |
719 | /* Cray can define user privs drop all prives now! | |
720 | * Not needed on PRIV_SU systems! | |
721 | */ | |
722 | drop_cray_privs(); | |
723 | #endif | |
724 | ||
e339aa53 | 725 | seed_rng(); |
726 | ||
5260325f | 727 | /* Read server configuration options from the configuration file. */ |
728 | read_server_config(&options, config_file_name); | |
729 | ||
730 | /* Fill in default values for those options not explicitly set. */ | |
731 | fill_default_server_options(&options); | |
732 | ||
5260325f | 733 | /* Check that there are no remaining arguments. */ |
734 | if (optind < ac) { | |
735 | fprintf(stderr, "Extra argument %s.\n", av[optind]); | |
736 | exit(1); | |
8efc0c15 | 737 | } |
5260325f | 738 | |
739 | debug("sshd version %.100s", SSH_VERSION); | |
740 | ||
fa08c86b | 741 | /* load private host keys */ |
742 | sensitive_data.host_keys = xmalloc(options.num_host_key_files*sizeof(Key*)); | |
184eed6a | 743 | for (i = 0; i < options.num_host_key_files; i++) |
1e3b8b07 | 744 | sensitive_data.host_keys[i] = NULL; |
fa08c86b | 745 | sensitive_data.server_key = NULL; |
746 | sensitive_data.ssh1_host_key = NULL; | |
747 | sensitive_data.have_ssh1_key = 0; | |
748 | sensitive_data.have_ssh2_key = 0; | |
a306f2dd | 749 | |
184eed6a | 750 | for (i = 0; i < options.num_host_key_files; i++) { |
aeaa3d9e | 751 | key = key_load_private(options.host_key_files[i], "", NULL); |
752 | sensitive_data.host_keys[i] = key; | |
fa08c86b | 753 | if (key == NULL) { |
58cfa257 | 754 | error("Could not load host key: %s", |
755 | options.host_key_files[i]); | |
aeaa3d9e | 756 | sensitive_data.host_keys[i] = NULL; |
fa08c86b | 757 | continue; |
a306f2dd | 758 | } |
6aacefa7 | 759 | switch (key->type) { |
fa08c86b | 760 | case KEY_RSA1: |
761 | sensitive_data.ssh1_host_key = key; | |
762 | sensitive_data.have_ssh1_key = 1; | |
763 | break; | |
764 | case KEY_RSA: | |
765 | case KEY_DSA: | |
766 | sensitive_data.have_ssh2_key = 1; | |
767 | break; | |
a306f2dd | 768 | } |
aeaa3d9e | 769 | debug("private host key: #%d type %d %s", i, key->type, |
770 | key_type(key)); | |
fa08c86b | 771 | } |
772 | if ((options.protocol & SSH_PROTO_1) && !sensitive_data.have_ssh1_key) { | |
773 | log("Disabling protocol version 1. Could not load host key"); | |
774 | options.protocol &= ~SSH_PROTO_1; | |
775 | } | |
776 | if ((options.protocol & SSH_PROTO_2) && !sensitive_data.have_ssh2_key) { | |
777 | log("Disabling protocol version 2. Could not load host key"); | |
778 | options.protocol &= ~SSH_PROTO_2; | |
a306f2dd | 779 | } |
6a416424 | 780 | if (!(options.protocol & (SSH_PROTO_1|SSH_PROTO_2))) { |
54b974dc | 781 | log("sshd: no hostkeys available -- exiting."); |
5260325f | 782 | exit(1); |
783 | } | |
5260325f | 784 | |
a306f2dd | 785 | /* Check certain values for sanity. */ |
786 | if (options.protocol & SSH_PROTO_1) { | |
787 | if (options.server_key_bits < 512 || | |
788 | options.server_key_bits > 32768) { | |
789 | fprintf(stderr, "Bad server key size.\n"); | |
790 | exit(1); | |
791 | } | |
792 | /* | |
793 | * Check that server and host key lengths differ sufficiently. This | |
794 | * is necessary to make double encryption work with rsaref. Oh, I | |
795 | * hate software patents. I dont know if this can go? Niels | |
796 | */ | |
797 | if (options.server_key_bits > | |
fa08c86b | 798 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) - SSH_KEY_BITS_RESERVED && |
a306f2dd | 799 | options.server_key_bits < |
fa08c86b | 800 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) { |
a306f2dd | 801 | options.server_key_bits = |
fa08c86b | 802 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED; |
a306f2dd | 803 | debug("Forcing server key to %d bits to make it differ from host key.", |
804 | options.server_key_bits); | |
805 | } | |
806 | } | |
807 | ||
f87f09aa | 808 | /* Configuration looks good, so exit if in test mode. */ |
809 | if (test_flag) | |
810 | exit(0); | |
811 | ||
77bb0bca | 812 | #ifdef HAVE_SCO_PROTECTED_PW |
813 | (void) set_auth_parameters(ac, av); | |
814 | #endif | |
815 | ||
a306f2dd | 816 | /* Initialize the log (it is reinitialized below in case we forked). */ |
5260325f | 817 | if (debug_flag && !inetd_flag) |
818 | log_stderr = 1; | |
1fe6a48f | 819 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
5260325f | 820 | |
a306f2dd | 821 | /* |
822 | * If not in debugging mode, and not started from inetd, disconnect | |
823 | * from the controlling terminal, and fork. The original process | |
824 | * exits. | |
825 | */ | |
0b6fbf03 | 826 | if (!(debug_flag || inetd_flag || no_daemon_flag)) { |
8efc0c15 | 827 | #ifdef TIOCNOTTY |
5260325f | 828 | int fd; |
8efc0c15 | 829 | #endif /* TIOCNOTTY */ |
5260325f | 830 | if (daemon(0, 0) < 0) |
831 | fatal("daemon() failed: %.200s", strerror(errno)); | |
832 | ||
833 | /* Disconnect from the controlling tty. */ | |
8efc0c15 | 834 | #ifdef TIOCNOTTY |
5ca51e19 | 835 | fd = open(_PATH_TTY, O_RDWR | O_NOCTTY); |
5260325f | 836 | if (fd >= 0) { |
837 | (void) ioctl(fd, TIOCNOTTY, NULL); | |
838 | close(fd); | |
839 | } | |
8efc0c15 | 840 | #endif /* TIOCNOTTY */ |
8efc0c15 | 841 | } |
5260325f | 842 | /* Reinitialize the log (because of the fork above). */ |
1fe6a48f | 843 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
5260325f | 844 | |
5260325f | 845 | /* Initialize the random number generator. */ |
846 | arc4random_stir(); | |
847 | ||
848 | /* Chdir to the root directory so that the current disk can be | |
849 | unmounted if desired. */ | |
850 | chdir("/"); | |
184eed6a | 851 | |
1d3c30db | 852 | /* ignore SIGPIPE */ |
853 | signal(SIGPIPE, SIG_IGN); | |
5260325f | 854 | |
5260325f | 855 | /* Start listening for a socket, unless started from inetd. */ |
856 | if (inetd_flag) { | |
ec1f12d3 | 857 | int s1; |
5260325f | 858 | s1 = dup(0); /* Make sure descriptors 0, 1, and 2 are in use. */ |
ec1f12d3 | 859 | dup(s1); |
5260325f | 860 | sock_in = dup(0); |
861 | sock_out = dup(1); | |
4c8722d9 | 862 | startup_pipe = -1; |
a306f2dd | 863 | /* |
864 | * We intentionally do not close the descriptors 0, 1, and 2 | |
865 | * as our code for setting the descriptors won\'t work if | |
866 | * ttyfd happens to be one of those. | |
867 | */ | |
5260325f | 868 | debug("inetd sockets after dupping: %d, %d", sock_in, sock_out); |
fa08c86b | 869 | if (options.protocol & SSH_PROTO_1) |
cb7bd922 | 870 | generate_ephemeral_server_key(); |
5260325f | 871 | } else { |
48e671d5 | 872 | for (ai = options.listen_addrs; ai; ai = ai->ai_next) { |
873 | if (ai->ai_family != AF_INET && ai->ai_family != AF_INET6) | |
874 | continue; | |
875 | if (num_listen_socks >= MAX_LISTEN_SOCKS) | |
876 | fatal("Too many listen sockets. " | |
877 | "Enlarge MAX_LISTEN_SOCKS"); | |
878 | if (getnameinfo(ai->ai_addr, ai->ai_addrlen, | |
879 | ntop, sizeof(ntop), strport, sizeof(strport), | |
880 | NI_NUMERICHOST|NI_NUMERICSERV) != 0) { | |
881 | error("getnameinfo failed"); | |
882 | continue; | |
883 | } | |
884 | /* Create socket for listening. */ | |
885 | listen_sock = socket(ai->ai_family, SOCK_STREAM, 0); | |
886 | if (listen_sock < 0) { | |
887 | /* kernel may not support ipv6 */ | |
888 | verbose("socket: %.100s", strerror(errno)); | |
889 | continue; | |
890 | } | |
891 | if (fcntl(listen_sock, F_SETFL, O_NONBLOCK) < 0) { | |
892 | error("listen_sock O_NONBLOCK: %s", strerror(errno)); | |
893 | close(listen_sock); | |
894 | continue; | |
895 | } | |
896 | /* | |
897 | * Set socket options. We try to make the port | |
898 | * reusable and have it close as fast as possible | |
899 | * without waiting in unnecessary wait states on | |
900 | * close. | |
901 | */ | |
902 | setsockopt(listen_sock, SOL_SOCKET, SO_REUSEADDR, | |
db518d9b | 903 | &on, sizeof(on)); |
48e671d5 | 904 | linger.l_onoff = 1; |
905 | linger.l_linger = 5; | |
906 | setsockopt(listen_sock, SOL_SOCKET, SO_LINGER, | |
db518d9b | 907 | &linger, sizeof(linger)); |
48e671d5 | 908 | |
909 | debug("Bind to port %s on %s.", strport, ntop); | |
910 | ||
911 | /* Bind the socket to the desired port. */ | |
32ced054 | 912 | if (bind(listen_sock, ai->ai_addr, ai->ai_addrlen) < 0) { |
913 | if (!ai->ai_next) | |
914 | error("Bind to port %s on %s failed: %.200s.", | |
915 | strport, ntop, strerror(errno)); | |
48e671d5 | 916 | close(listen_sock); |
917 | continue; | |
918 | } | |
919 | listen_socks[num_listen_socks] = listen_sock; | |
920 | num_listen_socks++; | |
921 | ||
922 | /* Start listening on the port. */ | |
923 | log("Server listening on %s port %s.", ntop, strport); | |
924 | if (listen(listen_sock, 5) < 0) | |
925 | fatal("listen: %.100s", strerror(errno)); | |
926 | ||
5260325f | 927 | } |
48e671d5 | 928 | freeaddrinfo(options.listen_addrs); |
929 | ||
930 | if (!num_listen_socks) | |
931 | fatal("Cannot bind any address."); | |
932 | ||
3aca00a3 | 933 | if (options.protocol & SSH_PROTO_1) |
934 | generate_ephemeral_server_key(); | |
935 | ||
936 | /* | |
937 | * Arrange to restart on SIGHUP. The handler needs | |
938 | * listen_sock. | |
939 | */ | |
940 | signal(SIGHUP, sighup_handler); | |
941 | ||
942 | signal(SIGTERM, sigterm_handler); | |
943 | signal(SIGQUIT, sigterm_handler); | |
944 | ||
945 | /* Arrange SIGCHLD to be caught. */ | |
946 | signal(SIGCHLD, main_sigchld_handler); | |
947 | ||
948 | /* Write out the pid file after the sigterm handler is setup */ | |
5260325f | 949 | if (!debug_flag) { |
aa3378df | 950 | /* |
97fb6912 | 951 | * Record our pid in /var/run/sshd.pid to make it |
952 | * easier to kill the correct sshd. We don't want to | |
953 | * do this before the bind above because the bind will | |
aa3378df | 954 | * fail if there already is a daemon, and this will |
955 | * overwrite any old pid in the file. | |
956 | */ | |
3c62e7eb | 957 | f = fopen(options.pid_file, "wb"); |
5260325f | 958 | if (f) { |
1e3b8b07 | 959 | fprintf(f, "%u\n", (u_int) getpid()); |
5260325f | 960 | fclose(f); |
961 | } | |
8efc0c15 | 962 | } |
5260325f | 963 | |
48e671d5 | 964 | /* setup fd set for listen */ |
089fbbd2 | 965 | fdset = NULL; |
48e671d5 | 966 | maxfd = 0; |
967 | for (i = 0; i < num_listen_socks; i++) | |
968 | if (listen_socks[i] > maxfd) | |
969 | maxfd = listen_socks[i]; | |
089fbbd2 | 970 | /* pipes connected to unauthenticated childs */ |
971 | startup_pipes = xmalloc(options.max_startups * sizeof(int)); | |
972 | for (i = 0; i < options.max_startups; i++) | |
973 | startup_pipes[i] = -1; | |
48e671d5 | 974 | |
aa3378df | 975 | /* |
976 | * Stay listening for connections until the system crashes or | |
977 | * the daemon is killed with a signal. | |
978 | */ | |
5260325f | 979 | for (;;) { |
980 | if (received_sighup) | |
981 | sighup_restart(); | |
089fbbd2 | 982 | if (fdset != NULL) |
983 | xfree(fdset); | |
b5c334cc | 984 | fdsetsz = howmany(maxfd+1, NFDBITS) * sizeof(fd_mask); |
089fbbd2 | 985 | fdset = (fd_set *)xmalloc(fdsetsz); |
48e671d5 | 986 | memset(fdset, 0, fdsetsz); |
089fbbd2 | 987 | |
48e671d5 | 988 | for (i = 0; i < num_listen_socks; i++) |
989 | FD_SET(listen_socks[i], fdset); | |
089fbbd2 | 990 | for (i = 0; i < options.max_startups; i++) |
991 | if (startup_pipes[i] != -1) | |
992 | FD_SET(startup_pipes[i], fdset); | |
993 | ||
994 | /* Wait in select until there is a connection. */ | |
59c97189 | 995 | ret = select(maxfd+1, fdset, NULL, NULL, NULL); |
996 | if (ret < 0 && errno != EINTR) | |
997 | error("select: %.100s", strerror(errno)); | |
c9130033 | 998 | if (received_sigterm) { |
999 | log("Received signal %d; terminating.", | |
010f9726 | 1000 | (int) received_sigterm); |
c9130033 | 1001 | close_listen_socks(); |
1002 | unlink(options.pid_file); | |
1003 | exit(255); | |
1004 | } | |
59c97189 | 1005 | if (key_used && key_do_regen) { |
cb7bd922 | 1006 | generate_ephemeral_server_key(); |
59c97189 | 1007 | key_used = 0; |
1008 | key_do_regen = 0; | |
48e671d5 | 1009 | } |
59c97189 | 1010 | if (ret < 0) |
1011 | continue; | |
1012 | ||
089fbbd2 | 1013 | for (i = 0; i < options.max_startups; i++) |
1014 | if (startup_pipes[i] != -1 && | |
1015 | FD_ISSET(startup_pipes[i], fdset)) { | |
1016 | /* | |
1017 | * the read end of the pipe is ready | |
1018 | * if the child has closed the pipe | |
8abcdba4 | 1019 | * after successful authentication |
089fbbd2 | 1020 | * or if the child has died |
1021 | */ | |
1022 | close(startup_pipes[i]); | |
1023 | startup_pipes[i] = -1; | |
1024 | startups--; | |
1025 | } | |
48e671d5 | 1026 | for (i = 0; i < num_listen_socks; i++) { |
1027 | if (!FD_ISSET(listen_socks[i], fdset)) | |
5260325f | 1028 | continue; |
089fbbd2 | 1029 | fromlen = sizeof(from); |
1030 | newsock = accept(listen_socks[i], (struct sockaddr *)&from, | |
1031 | &fromlen); | |
1032 | if (newsock < 0) { | |
1033 | if (errno != EINTR && errno != EWOULDBLOCK) | |
1034 | error("accept: %.100s", strerror(errno)); | |
1035 | continue; | |
1036 | } | |
1037 | if (fcntl(newsock, F_SETFL, 0) < 0) { | |
1038 | error("newsock del O_NONBLOCK: %s", strerror(errno)); | |
5e8948af | 1039 | close(newsock); |
089fbbd2 | 1040 | continue; |
1041 | } | |
c345cf9d | 1042 | if (drop_connection(startups) == 1) { |
1043 | debug("drop connection #%d", startups); | |
089fbbd2 | 1044 | close(newsock); |
1045 | continue; | |
1046 | } | |
1047 | if (pipe(startup_p) == -1) { | |
1048 | close(newsock); | |
1049 | continue; | |
1050 | } | |
1051 | ||
1052 | for (j = 0; j < options.max_startups; j++) | |
1053 | if (startup_pipes[j] == -1) { | |
1054 | startup_pipes[j] = startup_p[0]; | |
1055 | if (maxfd < startup_p[0]) | |
1056 | maxfd = startup_p[0]; | |
1057 | startups++; | |
1058 | break; | |
1059 | } | |
2b87da3b | 1060 | |
aa3378df | 1061 | /* |
089fbbd2 | 1062 | * Got connection. Fork a child to handle it, unless |
1063 | * we are in debugging mode. | |
aa3378df | 1064 | */ |
089fbbd2 | 1065 | if (debug_flag) { |
aa3378df | 1066 | /* |
089fbbd2 | 1067 | * In debugging mode. Close the listening |
1068 | * socket, and start processing the | |
1069 | * connection without forking. | |
aa3378df | 1070 | */ |
089fbbd2 | 1071 | debug("Server will not fork when running in debugging mode."); |
48e671d5 | 1072 | close_listen_socks(); |
5260325f | 1073 | sock_in = newsock; |
1074 | sock_out = newsock; | |
5540ea9b | 1075 | startup_pipe = -1; |
3f7a7e4a | 1076 | pid = getpid(); |
5260325f | 1077 | break; |
089fbbd2 | 1078 | } else { |
1079 | /* | |
1080 | * Normal production daemon. Fork, and have | |
1081 | * the child process the connection. The | |
1082 | * parent continues listening. | |
1083 | */ | |
1084 | if ((pid = fork()) == 0) { | |
1085 | /* | |
1086 | * Child. Close the listening and max_startup | |
1087 | * sockets. Start using the accepted socket. | |
1088 | * Reinitialize logging (since our pid has | |
1089 | * changed). We break out of the loop to handle | |
1090 | * the connection. | |
1091 | */ | |
1092 | startup_pipe = startup_p[1]; | |
7ace8c3b | 1093 | close_startup_pipes(); |
089fbbd2 | 1094 | close_listen_socks(); |
1095 | sock_in = newsock; | |
1096 | sock_out = newsock; | |
1fe6a48f | 1097 | log_init(__progname, options.log_level, options.log_facility, log_stderr); |
089fbbd2 | 1098 | break; |
1099 | } | |
5260325f | 1100 | } |
5260325f | 1101 | |
089fbbd2 | 1102 | /* Parent. Stay in the loop. */ |
1103 | if (pid < 0) | |
1104 | error("fork: %.100s", strerror(errno)); | |
1105 | else | |
1106 | debug("Forked child %d.", pid); | |
5260325f | 1107 | |
089fbbd2 | 1108 | close(startup_p[1]); |
5260325f | 1109 | |
089fbbd2 | 1110 | /* Mark that the key has been used (it was "given" to the child). */ |
59c97189 | 1111 | if ((options.protocol & SSH_PROTO_1) && |
1112 | key_used == 0) { | |
1113 | /* Schedule server key regeneration alarm. */ | |
1114 | signal(SIGALRM, key_regeneration_alarm); | |
1115 | alarm(options.key_regeneration_time); | |
1116 | key_used = 1; | |
1117 | } | |
5260325f | 1118 | |
089fbbd2 | 1119 | arc4random_stir(); |
1120 | ||
1121 | /* Close the new socket (the child is now taking care of it). */ | |
1122 | close(newsock); | |
1123 | } | |
48e671d5 | 1124 | /* child process check (or debug mode) */ |
1125 | if (num_listen_socks < 0) | |
1126 | break; | |
5260325f | 1127 | } |
1128 | } | |
8efc0c15 | 1129 | |
5260325f | 1130 | /* This is the child processing a new connection. */ |
1131 | ||
aa3378df | 1132 | /* |
1133 | * Disable the key regeneration alarm. We will not regenerate the | |
1134 | * key since we are no longer in a position to give it to anyone. We | |
1135 | * will not restart on SIGHUP since it no longer makes sense. | |
1136 | */ | |
5260325f | 1137 | alarm(0); |
1138 | signal(SIGALRM, SIG_DFL); | |
1139 | signal(SIGHUP, SIG_DFL); | |
1140 | signal(SIGTERM, SIG_DFL); | |
1141 | signal(SIGQUIT, SIG_DFL); | |
1142 | signal(SIGCHLD, SIG_DFL); | |
9aaf9be4 | 1143 | signal(SIGINT, SIG_DFL); |
5260325f | 1144 | |
aa3378df | 1145 | /* |
1146 | * Set socket options for the connection. We want the socket to | |
1147 | * close as fast as possible without waiting for anything. If the | |
1148 | * connection is not a socket, these will do nothing. | |
1149 | */ | |
1150 | /* setsockopt(sock_in, SOL_SOCKET, SO_REUSEADDR, (void *)&on, sizeof(on)); */ | |
5260325f | 1151 | linger.l_onoff = 1; |
1152 | linger.l_linger = 5; | |
db518d9b | 1153 | setsockopt(sock_in, SOL_SOCKET, SO_LINGER, &linger, sizeof(linger)); |
5260325f | 1154 | |
b5c334cc | 1155 | /* Set keepalives if requested. */ |
1156 | if (options.keepalives && | |
db518d9b | 1157 | setsockopt(sock_in, SOL_SOCKET, SO_KEEPALIVE, &on, |
b5c334cc | 1158 | sizeof(on)) < 0) |
1159 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); | |
1160 | ||
aa3378df | 1161 | /* |
1162 | * Register our connection. This turns encryption off because we do | |
1163 | * not have a key. | |
1164 | */ | |
5260325f | 1165 | packet_set_connection(sock_in, sock_out); |
1166 | ||
1167 | remote_port = get_remote_port(); | |
1168 | remote_ip = get_remote_ipaddr(); | |
1169 | ||
5260325f | 1170 | #ifdef LIBWRAP |
ac28afd8 | 1171 | /* Check whether logins are denied from this host. */ |
5260325f | 1172 | { |
1173 | struct request_info req; | |
8efc0c15 | 1174 | |
8fbc356d | 1175 | request_init(&req, RQ_DAEMON, __progname, RQ_FILE, sock_in, 0); |
5260325f | 1176 | fromhost(&req); |
8efc0c15 | 1177 | |
5260325f | 1178 | if (!hosts_access(&req)) { |
ac28afd8 | 1179 | debug("Connection refused by tcp wrapper"); |
563834bb | 1180 | refuse(&req); |
ac28afd8 | 1181 | /* NOTREACHED */ |
1182 | fatal("libwrap refuse returns"); | |
5260325f | 1183 | } |
8efc0c15 | 1184 | } |
48e671d5 | 1185 | #endif /* LIBWRAP */ |
ac28afd8 | 1186 | |
5260325f | 1187 | /* Log the connection. */ |
1188 | verbose("Connection from %.500s port %d", remote_ip, remote_port); | |
8efc0c15 | 1189 | |
aa3378df | 1190 | /* |
1191 | * We don\'t want to listen forever unless the other side | |
1192 | * successfully authenticates itself. So we set up an alarm which is | |
1193 | * cleared after successful authentication. A limit of zero | |
1194 | * indicates no limit. Note that we don\'t set the alarm in debugging | |
1195 | * mode; it is just annoying to have the server exit just when you | |
1196 | * are about to discover the bug. | |
1197 | */ | |
5260325f | 1198 | signal(SIGALRM, grace_alarm_handler); |
1199 | if (!debug_flag) | |
1200 | alarm(options.login_grace_time); | |
1201 | ||
7368a6c8 | 1202 | sshd_exchange_identification(sock_in, sock_out); |
aa3378df | 1203 | /* |
6ffc9c88 | 1204 | * Check that the connection comes from a privileged port. |
1205 | * Rhosts-Authentication only makes sense from priviledged | |
aa3378df | 1206 | * programs. Of course, if the intruder has root access on his local |
1207 | * machine, he can connect from any port. So do not use these | |
1208 | * authentication methods from machines that you do not trust. | |
1209 | */ | |
44b1a8e5 | 1210 | if (options.rhosts_authentication && |
1211 | (remote_port >= IPPORT_RESERVED || | |
1212 | remote_port < IPPORT_RESERVED / 2)) { | |
6ffc9c88 | 1213 | debug("Rhosts Authentication disabled, " |
9ae3f727 | 1214 | "originating port %d not trusted.", remote_port); |
5260325f | 1215 | options.rhosts_authentication = 0; |
5260325f | 1216 | } |
ced49be2 | 1217 | #if defined(KRB4) && !defined(KRB5) |
48e671d5 | 1218 | if (!packet_connection_is_ipv4() && |
1219 | options.kerberos_authentication) { | |
1220 | debug("Kerberos Authentication disabled, only available for IPv4."); | |
1221 | options.kerberos_authentication = 0; | |
1222 | } | |
ced49be2 | 1223 | #endif /* KRB4 && !KRB5 */ |
abf1f107 | 1224 | #ifdef AFS |
1225 | /* If machine has AFS, set process authentication group. */ | |
1226 | if (k_hasafs()) { | |
1227 | k_setpag(); | |
1228 | k_unlog(); | |
1229 | } | |
1230 | #endif /* AFS */ | |
48e671d5 | 1231 | |
5260325f | 1232 | packet_set_nonblocking(); |
1233 | ||
7b2ea3a1 | 1234 | /* perform the key exchange */ |
7b2ea3a1 | 1235 | /* authenticate user and start session */ |
e78a59f5 | 1236 | if (compat20) { |
1237 | do_ssh2_kex(); | |
63284fbb | 1238 | do_authentication2(); |
e78a59f5 | 1239 | } else { |
1240 | do_ssh1_kex(); | |
63284fbb | 1241 | do_authentication(); |
e78a59f5 | 1242 | } |
63284fbb | 1243 | /* The connection has been terminated. */ |
1244 | verbose("Closing connection to %.100s", remote_ip); | |
8efc0c15 | 1245 | |
d94aa2ae | 1246 | #ifdef USE_PAM |
a5c9cd31 | 1247 | finish_pam(); |
d94aa2ae | 1248 | #endif /* USE_PAM */ |
8efc0c15 | 1249 | |
5260325f | 1250 | packet_close(); |
1251 | exit(0); | |
1252 | } | |
8efc0c15 | 1253 | |
5260325f | 1254 | /* |
7b2ea3a1 | 1255 | * SSH1 key exchange |
5260325f | 1256 | */ |
396c147e | 1257 | static void |
1e3b8b07 | 1258 | do_ssh1_kex(void) |
8efc0c15 | 1259 | { |
5260325f | 1260 | int i, len; |
46aa2d1f | 1261 | int rsafail = 0; |
5260325f | 1262 | BIGNUM *session_key_int; |
1e3b8b07 | 1263 | u_char session_key[SSH_SESSION_KEY_LENGTH]; |
1264 | u_char cookie[8]; | |
1265 | u_int cipher_type, auth_mask, protocol_flags; | |
5260325f | 1266 | u_int32_t rand = 0; |
1267 | ||
aa3378df | 1268 | /* |
1269 | * Generate check bytes that the client must send back in the user | |
1270 | * packet in order for it to be accepted; this is used to defy ip | |
1271 | * spoofing attacks. Note that this only works against somebody | |
1272 | * doing IP spoofing from a remote machine; any machine on the local | |
1273 | * network can still see outgoing packets and catch the random | |
1274 | * cookie. This only affects rhosts authentication, and this is one | |
1275 | * of the reasons why it is inherently insecure. | |
1276 | */ | |
5260325f | 1277 | for (i = 0; i < 8; i++) { |
1278 | if (i % 4 == 0) | |
1279 | rand = arc4random(); | |
7b2ea3a1 | 1280 | cookie[i] = rand & 0xff; |
5260325f | 1281 | rand >>= 8; |
1282 | } | |
1283 | ||
aa3378df | 1284 | /* |
1285 | * Send our public key. We include in the packet 64 bits of random | |
1286 | * data that must be matched in the reply in order to prevent IP | |
1287 | * spoofing. | |
1288 | */ | |
5260325f | 1289 | packet_start(SSH_SMSG_PUBLIC_KEY); |
1290 | for (i = 0; i < 8; i++) | |
7b2ea3a1 | 1291 | packet_put_char(cookie[i]); |
5260325f | 1292 | |
1293 | /* Store our public server RSA key. */ | |
fa08c86b | 1294 | packet_put_int(BN_num_bits(sensitive_data.server_key->rsa->n)); |
1295 | packet_put_bignum(sensitive_data.server_key->rsa->e); | |
1296 | packet_put_bignum(sensitive_data.server_key->rsa->n); | |
5260325f | 1297 | |
1298 | /* Store our public host RSA key. */ | |
fa08c86b | 1299 | packet_put_int(BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); |
1300 | packet_put_bignum(sensitive_data.ssh1_host_key->rsa->e); | |
1301 | packet_put_bignum(sensitive_data.ssh1_host_key->rsa->n); | |
5260325f | 1302 | |
1303 | /* Put protocol flags. */ | |
1304 | packet_put_int(SSH_PROTOFLAG_HOST_IN_FWD_OPEN); | |
1305 | ||
1306 | /* Declare which ciphers we support. */ | |
94ec8c6b | 1307 | packet_put_int(cipher_mask_ssh1(0)); |
5260325f | 1308 | |
1309 | /* Declare supported authentication types. */ | |
1310 | auth_mask = 0; | |
1311 | if (options.rhosts_authentication) | |
1312 | auth_mask |= 1 << SSH_AUTH_RHOSTS; | |
1313 | if (options.rhosts_rsa_authentication) | |
1314 | auth_mask |= 1 << SSH_AUTH_RHOSTS_RSA; | |
1315 | if (options.rsa_authentication) | |
1316 | auth_mask |= 1 << SSH_AUTH_RSA; | |
ced49be2 | 1317 | #if defined(KRB4) || defined(KRB5) |
5260325f | 1318 | if (options.kerberos_authentication) |
1319 | auth_mask |= 1 << SSH_AUTH_KERBEROS; | |
8efc0c15 | 1320 | #endif |
ced49be2 | 1321 | #if defined(AFS) || defined(KRB5) |
5260325f | 1322 | if (options.kerberos_tgt_passing) |
1323 | auth_mask |= 1 << SSH_PASS_KERBEROS_TGT; | |
ced49be2 | 1324 | #endif |
1325 | #ifdef AFS | |
5260325f | 1326 | if (options.afs_token_passing) |
1327 | auth_mask |= 1 << SSH_PASS_AFS_TOKEN; | |
8efc0c15 | 1328 | #endif |
5ba55ada | 1329 | if (options.challenge_response_authentication == 1) |
5260325f | 1330 | auth_mask |= 1 << SSH_AUTH_TIS; |
5260325f | 1331 | if (options.password_authentication) |
1332 | auth_mask |= 1 << SSH_AUTH_PASSWORD; | |
1333 | packet_put_int(auth_mask); | |
1334 | ||
1335 | /* Send the packet and wait for it to be sent. */ | |
1336 | packet_send(); | |
1337 | packet_write_wait(); | |
1338 | ||
fa08c86b | 1339 | debug("Sent %d bit server key and %d bit host key.", |
1340 | BN_num_bits(sensitive_data.server_key->rsa->n), | |
1341 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n)); | |
5260325f | 1342 | |
1343 | /* Read clients reply (cipher type and session key). */ | |
54a5250f | 1344 | packet_read_expect(SSH_CMSG_SESSION_KEY); |
5260325f | 1345 | |
2d86a6cc | 1346 | /* Get cipher type and check whether we accept this. */ |
5260325f | 1347 | cipher_type = packet_get_char(); |
1348 | ||
94ec8c6b | 1349 | if (!(cipher_mask_ssh1(0) & (1 << cipher_type))) |
2d86a6cc | 1350 | packet_disconnect("Warning: client selects unsupported cipher."); |
1351 | ||
5260325f | 1352 | /* Get check bytes from the packet. These must match those we |
1353 | sent earlier with the public key packet. */ | |
1354 | for (i = 0; i < 8; i++) | |
7b2ea3a1 | 1355 | if (cookie[i] != packet_get_char()) |
5260325f | 1356 | packet_disconnect("IP Spoofing check bytes do not match."); |
1357 | ||
1358 | debug("Encryption type: %.200s", cipher_name(cipher_type)); | |
1359 | ||
1360 | /* Get the encrypted integer. */ | |
b775c6f2 | 1361 | if ((session_key_int = BN_new()) == NULL) |
1362 | fatal("do_ssh1_kex: BN_new failed"); | |
20b279e6 | 1363 | packet_get_bignum(session_key_int); |
5260325f | 1364 | |
5260325f | 1365 | protocol_flags = packet_get_int(); |
1366 | packet_set_protocol_flags(protocol_flags); | |
95500969 | 1367 | packet_check_eom(); |
5260325f | 1368 | |
aa3378df | 1369 | /* |
1370 | * Decrypt it using our private server key and private host key (key | |
1371 | * with larger modulus first). | |
1372 | */ | |
fa08c86b | 1373 | if (BN_cmp(sensitive_data.server_key->rsa->n, sensitive_data.ssh1_host_key->rsa->n) > 0) { |
46aa2d1f | 1374 | /* Server key has bigger modulus. */ |
fa08c86b | 1375 | if (BN_num_bits(sensitive_data.server_key->rsa->n) < |
1376 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) + SSH_KEY_BITS_RESERVED) { | |
1377 | fatal("do_connection: %s: server_key %d < host_key %d + SSH_KEY_BITS_RESERVED %d", | |
1378 | get_remote_ipaddr(), | |
1379 | BN_num_bits(sensitive_data.server_key->rsa->n), | |
1380 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), | |
1381 | SSH_KEY_BITS_RESERVED); | |
5260325f | 1382 | } |
46aa2d1f | 1383 | if (rsa_private_decrypt(session_key_int, session_key_int, |
1384 | sensitive_data.server_key->rsa) <= 0) | |
1385 | rsafail++; | |
1386 | if (rsa_private_decrypt(session_key_int, session_key_int, | |
1387 | sensitive_data.ssh1_host_key->rsa) <= 0) | |
1388 | rsafail++; | |
5260325f | 1389 | } else { |
1390 | /* Host key has bigger modulus (or they are equal). */ | |
fa08c86b | 1391 | if (BN_num_bits(sensitive_data.ssh1_host_key->rsa->n) < |
1392 | BN_num_bits(sensitive_data.server_key->rsa->n) + SSH_KEY_BITS_RESERVED) { | |
1393 | fatal("do_connection: %s: host_key %d < server_key %d + SSH_KEY_BITS_RESERVED %d", | |
1394 | get_remote_ipaddr(), | |
1395 | BN_num_bits(sensitive_data.ssh1_host_key->rsa->n), | |
1396 | BN_num_bits(sensitive_data.server_key->rsa->n), | |
1397 | SSH_KEY_BITS_RESERVED); | |
5260325f | 1398 | } |
46aa2d1f | 1399 | if (rsa_private_decrypt(session_key_int, session_key_int, |
1400 | sensitive_data.ssh1_host_key->rsa) < 0) | |
1401 | rsafail++; | |
1402 | if (rsa_private_decrypt(session_key_int, session_key_int, | |
1403 | sensitive_data.server_key->rsa) < 0) | |
1404 | rsafail++; | |
5260325f | 1405 | } |
aa3378df | 1406 | /* |
1407 | * Extract session key from the decrypted integer. The key is in the | |
1408 | * least significant 256 bits of the integer; the first byte of the | |
1409 | * key is in the highest bits. | |
1410 | */ | |
46aa2d1f | 1411 | if (!rsafail) { |
1412 | BN_mask_bits(session_key_int, sizeof(session_key) * 8); | |
1413 | len = BN_num_bytes(session_key_int); | |
1414 | if (len < 0 || len > sizeof(session_key)) { | |
1415 | error("do_connection: bad session key len from %s: " | |
5ca51e19 | 1416 | "session_key_int %d > sizeof(session_key) %lu", |
1417 | get_remote_ipaddr(), len, (u_long)sizeof(session_key)); | |
46aa2d1f | 1418 | rsafail++; |
1419 | } else { | |
1420 | memset(session_key, 0, sizeof(session_key)); | |
1421 | BN_bn2bin(session_key_int, | |
1422 | session_key + sizeof(session_key) - len); | |
00be5382 | 1423 | |
1424 | compute_session_id(session_id, cookie, | |
1425 | sensitive_data.ssh1_host_key->rsa->n, | |
1426 | sensitive_data.server_key->rsa->n); | |
1427 | /* | |
1428 | * Xor the first 16 bytes of the session key with the | |
1429 | * session id. | |
1430 | */ | |
1431 | for (i = 0; i < 16; i++) | |
1432 | session_key[i] ^= session_id[i]; | |
46aa2d1f | 1433 | } |
1434 | } | |
1435 | if (rsafail) { | |
00be5382 | 1436 | int bytes = BN_num_bytes(session_key_int); |
f6b1ba8f | 1437 | u_char *buf = xmalloc(bytes); |
00be5382 | 1438 | MD5_CTX md; |
1439 | ||
46aa2d1f | 1440 | log("do_connection: generating a fake encryption key"); |
00be5382 | 1441 | BN_bn2bin(session_key_int, buf); |
1442 | MD5_Init(&md); | |
1443 | MD5_Update(&md, buf, bytes); | |
1444 | MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); | |
1445 | MD5_Final(session_key, &md); | |
1446 | MD5_Init(&md); | |
1447 | MD5_Update(&md, session_key, 16); | |
1448 | MD5_Update(&md, buf, bytes); | |
1449 | MD5_Update(&md, sensitive_data.ssh1_cookie, SSH_SESSION_KEY_LENGTH); | |
1450 | MD5_Final(session_key + 16, &md); | |
1451 | memset(buf, 0, bytes); | |
1452 | xfree(buf); | |
0572fe75 | 1453 | for (i = 0; i < 16; i++) |
1454 | session_id[i] = session_key[i] ^ session_key[i + 16]; | |
46aa2d1f | 1455 | } |
63284fbb | 1456 | /* Destroy the private and public keys. They will no longer be needed. */ |
1457 | destroy_sensitive_data(); | |
00be5382 | 1458 | |
7b2ea3a1 | 1459 | /* Destroy the decrypted integer. It is no longer needed. */ |
1460 | BN_clear_free(session_key_int); | |
1461 | ||
5260325f | 1462 | /* Set the session key. From this on all communications will be encrypted. */ |
1463 | packet_set_encryption_key(session_key, SSH_SESSION_KEY_LENGTH, cipher_type); | |
1464 | ||
1465 | /* Destroy our copy of the session key. It is no longer needed. */ | |
1466 | memset(session_key, 0, sizeof(session_key)); | |
1467 | ||
1468 | debug("Received session key; encryption turned on."); | |
1469 | ||
1470 | /* Send an acknowledgement packet. Note that this packet is sent encrypted. */ | |
1471 | packet_start(SSH_SMSG_SUCCESS); | |
1472 | packet_send(); | |
1473 | packet_write_wait(); | |
5260325f | 1474 | } |
e78a59f5 | 1475 | |
1476 | /* | |
1477 | * SSH2 key exchange: diffie-hellman-group1-sha1 | |
1478 | */ | |
396c147e | 1479 | static void |
1e3b8b07 | 1480 | do_ssh2_kex(void) |
e78a59f5 | 1481 | { |
e78a59f5 | 1482 | Kex *kex; |
e78a59f5 | 1483 | |
a8be9f80 | 1484 | if (options.ciphers != NULL) { |
6ae2364d | 1485 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
a8be9f80 | 1486 | myproposal[PROPOSAL_ENC_ALGS_STOC] = options.ciphers; |
1487 | } | |
1ad64a93 | 1488 | myproposal[PROPOSAL_ENC_ALGS_CTOS] = |
1489 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_CTOS]); | |
1490 | myproposal[PROPOSAL_ENC_ALGS_STOC] = | |
1491 | compat_cipher_proposal(myproposal[PROPOSAL_ENC_ALGS_STOC]); | |
1492 | ||
b2552997 | 1493 | if (options.macs != NULL) { |
1494 | myproposal[PROPOSAL_MAC_ALGS_CTOS] = | |
1495 | myproposal[PROPOSAL_MAC_ALGS_STOC] = options.macs; | |
1496 | } | |
fa08c86b | 1497 | myproposal[PROPOSAL_SERVER_HOST_KEY_ALGS] = list_hostkey_types(); |
1498 | ||
7a37c112 | 1499 | /* start key exchange */ |
d8ee838b | 1500 | kex = kex_setup(myproposal); |
a5c9ffdb | 1501 | kex->server = 1; |
1502 | kex->client_version_string=client_version_string; | |
1503 | kex->server_version_string=server_version_string; | |
1504 | kex->load_host_key=&get_hostkey_by_type; | |
94ec8c6b | 1505 | |
7a37c112 | 1506 | xxx_kex = kex; |
1507 | ||
c422989b | 1508 | dispatch_run(DISPATCH_BLOCK, &kex->done, kex); |
94ec8c6b | 1509 | |
d1ac6175 | 1510 | session_id2 = kex->session_id; |
1511 | session_id2_len = kex->session_id_len; | |
1512 | ||
94ec8c6b | 1513 | #ifdef DEBUG_KEXDH |
1514 | /* send 1st encrypted/maced/compressed message */ | |
1515 | packet_start(SSH2_MSG_IGNORE); | |
1516 | packet_put_cstring("markus"); | |
1517 | packet_send(); | |
1518 | packet_write_wait(); | |
1519 | #endif | |
a5c9ffdb | 1520 | debug("KEX done"); |
e78a59f5 | 1521 | } |