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5d82ad35 | 1 | /* $OpenBSD: packet.c,v 1.166 2009/06/27 09:29:06 andreas Exp $ */ |
8efc0c15 | 2 | /* |
5260325f | 3 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
5260325f | 4 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
5 | * All rights reserved | |
5260325f | 6 | * This file contains code implementing the packet protocol and communication |
7 | * with the other side. This same code is used both on client and server side. | |
7e7327a1 | 8 | * |
bcbf86ec | 9 | * As far as I am concerned, the code I have written for this software |
10 | * can be used freely for any purpose. Any derived versions of this | |
11 | * software must be clearly marked as such, and if the derived work is | |
12 | * incompatible with the protocol description in the RFC file, it must be | |
13 | * called by a name other than "ssh" or "Secure Shell". | |
14 | * | |
15 | * | |
7e7327a1 | 16 | * SSH2 packet format added by Markus Friedl. |
a96070d4 | 17 | * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. |
bcbf86ec | 18 | * |
19 | * Redistribution and use in source and binary forms, with or without | |
20 | * modification, are permitted provided that the following conditions | |
21 | * are met: | |
22 | * 1. Redistributions of source code must retain the above copyright | |
23 | * notice, this list of conditions and the following disclaimer. | |
24 | * 2. Redistributions in binary form must reproduce the above copyright | |
25 | * notice, this list of conditions and the following disclaimer in the | |
26 | * documentation and/or other materials provided with the distribution. | |
7e7327a1 | 27 | * |
bcbf86ec | 28 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
29 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
30 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
31 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
32 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
33 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
34 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
35 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
36 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
37 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
5260325f | 38 | */ |
8efc0c15 | 39 | |
40 | #include "includes.h" | |
a3dcf543 | 41 | |
5b04a8bf | 42 | #include <sys/types.h> |
2f5b2528 | 43 | #include "openbsd-compat/sys-queue.h" |
536c14e8 | 44 | #include <sys/param.h> |
9794d008 | 45 | #include <sys/socket.h> |
e264ac72 | 46 | #ifdef HAVE_SYS_TIME_H |
47 | # include <sys/time.h> | |
48 | #endif | |
9794d008 | 49 | |
9794d008 | 50 | #include <netinet/in.h> |
a3dcf543 | 51 | #include <netinet/ip.h> |
c5bca5d4 | 52 | #include <arpa/inet.h> |
8efc0c15 | 53 | |
028094f4 | 54 | #include <errno.h> |
4c72fcfd | 55 | #include <stdarg.h> |
cf851879 | 56 | #include <stdio.h> |
ffa517a8 | 57 | #include <stdlib.h> |
00146caa | 58 | #include <string.h> |
5188ba17 | 59 | #include <unistd.h> |
31652869 | 60 | #include <signal.h> |
4c72fcfd | 61 | |
8efc0c15 | 62 | #include "xmalloc.h" |
63 | #include "buffer.h" | |
64 | #include "packet.h" | |
8efc0c15 | 65 | #include "crc32.h" |
8efc0c15 | 66 | #include "compress.h" |
67 | #include "deattack.h" | |
a5efa1bb | 68 | #include "channels.h" |
7e7327a1 | 69 | #include "compat.h" |
42f11eb2 | 70 | #include "ssh1.h" |
7e7327a1 | 71 | #include "ssh2.h" |
94ec8c6b | 72 | #include "cipher.h" |
31652869 | 73 | #include "key.h" |
7e7327a1 | 74 | #include "kex.h" |
b2552997 | 75 | #include "mac.h" |
42f11eb2 | 76 | #include "log.h" |
77 | #include "canohost.h" | |
2ac91be1 | 78 | #include "misc.h" |
9459414c | 79 | #include "ssh.h" |
d0137ef8 | 80 | #include "roaming.h" |
7e7327a1 | 81 | |
82 | #ifdef PACKET_DEBUG | |
83 | #define DBG(x) x | |
84 | #else | |
85 | #define DBG(x) | |
86 | #endif | |
87 | ||
608bcf58 | 88 | #define PACKET_MAX_SIZE (256 * 1024) |
89 | ||
dc1f1948 | 90 | struct packet_state { |
91 | u_int32_t seqnr; | |
92 | u_int32_t packets; | |
93 | u_int64_t blocks; | |
94 | u_int64_t bytes; | |
95 | }; | |
8efc0c15 | 96 | |
dc1f1948 | 97 | struct packet { |
98 | TAILQ_ENTRY(packet) next; | |
99 | u_char type; | |
100 | Buffer payload; | |
101 | }; | |
8efc0c15 | 102 | |
dc1f1948 | 103 | struct session_state { |
104 | /* | |
105 | * This variable contains the file descriptors used for | |
106 | * communicating with the other side. connection_in is used for | |
107 | * reading; connection_out for writing. These can be the same | |
108 | * descriptor, in which case it is assumed to be a socket. | |
109 | */ | |
110 | int connection_in; | |
111 | int connection_out; | |
5260325f | 112 | |
dc1f1948 | 113 | /* Protocol flags for the remote side. */ |
114 | u_int remote_protocol_flags; | |
8efc0c15 | 115 | |
dc1f1948 | 116 | /* Encryption context for receiving data. Only used for decryption. */ |
117 | CipherContext receive_context; | |
8efc0c15 | 118 | |
dc1f1948 | 119 | /* Encryption context for sending data. Only used for encryption. */ |
120 | CipherContext send_context; | |
8efc0c15 | 121 | |
dc1f1948 | 122 | /* Buffer for raw input data from the socket. */ |
123 | Buffer input; | |
8efc0c15 | 124 | |
dc1f1948 | 125 | /* Buffer for raw output data going to the socket. */ |
126 | Buffer output; | |
8efc0c15 | 127 | |
dc1f1948 | 128 | /* Buffer for the partial outgoing packet being constructed. */ |
129 | Buffer outgoing_packet; | |
8efc0c15 | 130 | |
dc1f1948 | 131 | /* Buffer for the incoming packet currently being processed. */ |
132 | Buffer incoming_packet; | |
8efc0c15 | 133 | |
dc1f1948 | 134 | /* Scratch buffer for packet compression/decompression. */ |
135 | Buffer compression_buffer; | |
136 | int compression_buffer_ready; | |
9d6b7add | 137 | |
dc1f1948 | 138 | /* |
139 | * Flag indicating whether packet compression/decompression is | |
140 | * enabled. | |
141 | */ | |
142 | int packet_compression; | |
8efc0c15 | 143 | |
dc1f1948 | 144 | /* default maximum packet size */ |
145 | u_int max_packet_size; | |
8efc0c15 | 146 | |
dc1f1948 | 147 | /* Flag indicating whether this module has been initialized. */ |
148 | int initialized; | |
07200973 | 149 | |
dc1f1948 | 150 | /* Set to true if the connection is interactive. */ |
151 | int interactive_mode; | |
07200973 | 152 | |
dc1f1948 | 153 | /* Set to true if we are the server side. */ |
154 | int server_side; | |
ac47b626 | 155 | |
dc1f1948 | 156 | /* Set to true if we are authenticated. */ |
157 | int after_authentication; | |
bc2d97c8 | 158 | |
dc1f1948 | 159 | int keep_alive_timeouts; |
ffd7b36b | 160 | |
dc1f1948 | 161 | /* The maximum time that we will wait to send or receive a packet */ |
162 | int packet_timeout_ms; | |
7e7327a1 | 163 | |
dc1f1948 | 164 | /* Session key information for Encryption and MAC */ |
165 | Newkeys *newkeys[MODE_MAX]; | |
166 | struct packet_state p_read, p_send; | |
9459414c | 167 | |
dc1f1948 | 168 | u_int64_t max_blocks_in, max_blocks_out; |
169 | u_int32_t rekey_limit; | |
b4b701be | 170 | |
dc1f1948 | 171 | /* Session key for protocol v1 */ |
172 | u_char ssh1_key[SSH_SESSION_KEY_LENGTH]; | |
173 | u_int ssh1_keylen; | |
608bcf58 | 174 | |
dc1f1948 | 175 | /* roundup current message to extra_pad bytes */ |
176 | u_char extra_pad; | |
177 | ||
178 | /* XXX discard incoming data after MAC error */ | |
179 | u_int packet_discard; | |
180 | Mac *packet_discard_mac; | |
181 | ||
182 | /* Used in packet_read_poll2() */ | |
183 | u_int packlen; | |
184 | ||
6a49252d | 185 | /* Used in packet_send2 */ |
186 | int rekeying; | |
187 | ||
188 | /* Used in packet_set_interactive */ | |
189 | int set_interactive_called; | |
190 | ||
191 | /* Used in packet_set_maxsize */ | |
192 | int set_maxsize_called; | |
193 | ||
dc1f1948 | 194 | TAILQ_HEAD(, packet) outgoing; |
ffd7b36b | 195 | }; |
dc1f1948 | 196 | |
5d82ad35 | 197 | static struct session_state *active_state, *backup_state; |
dc1f1948 | 198 | |
199 | static struct session_state * | |
adb5cc1b | 200 | alloc_session_state(void) |
dc1f1948 | 201 | { |
202 | struct session_state *s = xcalloc(1, sizeof(*s)); | |
203 | ||
204 | s->connection_in = -1; | |
205 | s->connection_out = -1; | |
206 | s->max_packet_size = 32768; | |
207 | s->packet_timeout_ms = -1; | |
208 | return s; | |
209 | } | |
ffd7b36b | 210 | |
aa3378df | 211 | /* |
212 | * Sets the descriptors used for communication. Disables encryption until | |
213 | * packet_set_encryption_key is called. | |
214 | */ | |
8efc0c15 | 215 | void |
216 | packet_set_connection(int fd_in, int fd_out) | |
217 | { | |
94ec8c6b | 218 | Cipher *none = cipher_by_name("none"); |
e1feb9bf | 219 | |
94ec8c6b | 220 | if (none == NULL) |
221 | fatal("packet_set_connection: cannot load cipher 'none'"); | |
dc1f1948 | 222 | if (active_state == NULL) |
223 | active_state = alloc_session_state(); | |
224 | active_state->connection_in = fd_in; | |
225 | active_state->connection_out = fd_out; | |
226 | cipher_init(&active_state->send_context, none, (const u_char *)"", | |
f6be21a0 | 227 | 0, NULL, 0, CIPHER_ENCRYPT); |
dc1f1948 | 228 | cipher_init(&active_state->receive_context, none, (const u_char *)"", |
f6be21a0 | 229 | 0, NULL, 0, CIPHER_DECRYPT); |
dc1f1948 | 230 | active_state->newkeys[MODE_IN] = active_state->newkeys[MODE_OUT] = NULL; |
231 | if (!active_state->initialized) { | |
232 | active_state->initialized = 1; | |
233 | buffer_init(&active_state->input); | |
234 | buffer_init(&active_state->output); | |
235 | buffer_init(&active_state->outgoing_packet); | |
236 | buffer_init(&active_state->incoming_packet); | |
237 | TAILQ_INIT(&active_state->outgoing); | |
238 | active_state->p_send.packets = active_state->p_read.packets = 0; | |
5260325f | 239 | } |
8efc0c15 | 240 | } |
241 | ||
bc2d97c8 | 242 | void |
243 | packet_set_timeout(int timeout, int count) | |
244 | { | |
245 | if (timeout == 0 || count == 0) { | |
dc1f1948 | 246 | active_state->packet_timeout_ms = -1; |
bc2d97c8 | 247 | return; |
248 | } | |
249 | if ((INT_MAX / 1000) / count < timeout) | |
dc1f1948 | 250 | active_state->packet_timeout_ms = INT_MAX; |
bc2d97c8 | 251 | else |
dc1f1948 | 252 | active_state->packet_timeout_ms = timeout * count * 1000; |
bc2d97c8 | 253 | } |
254 | ||
608bcf58 | 255 | static void |
256 | packet_stop_discard(void) | |
257 | { | |
dc1f1948 | 258 | if (active_state->packet_discard_mac) { |
608bcf58 | 259 | char buf[1024]; |
260 | ||
261 | memset(buf, 'a', sizeof(buf)); | |
dc1f1948 | 262 | while (buffer_len(&active_state->incoming_packet) < |
263 | PACKET_MAX_SIZE) | |
264 | buffer_append(&active_state->incoming_packet, buf, | |
265 | sizeof(buf)); | |
266 | (void) mac_compute(active_state->packet_discard_mac, | |
267 | active_state->p_read.seqnr, | |
268 | buffer_ptr(&active_state->incoming_packet), | |
608bcf58 | 269 | PACKET_MAX_SIZE); |
270 | } | |
271 | logit("Finished discarding for %.200s", get_remote_ipaddr()); | |
272 | cleanup_exit(255); | |
273 | } | |
274 | ||
275 | static void | |
276 | packet_start_discard(Enc *enc, Mac *mac, u_int packet_length, u_int discard) | |
277 | { | |
8b773163 | 278 | if (enc == NULL || !cipher_is_cbc(enc->cipher)) |
608bcf58 | 279 | packet_disconnect("Packet corrupt"); |
280 | if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled) | |
dc1f1948 | 281 | active_state->packet_discard_mac = mac; |
282 | if (buffer_len(&active_state->input) >= discard) | |
608bcf58 | 283 | packet_stop_discard(); |
dc1f1948 | 284 | active_state->packet_discard = discard - |
285 | buffer_len(&active_state->input); | |
608bcf58 | 286 | } |
287 | ||
48e671d5 | 288 | /* Returns 1 if remote host is connected via socket, 0 if not. */ |
289 | ||
290 | int | |
d5bb9418 | 291 | packet_connection_is_on_socket(void) |
48e671d5 | 292 | { |
293 | struct sockaddr_storage from, to; | |
294 | socklen_t fromlen, tolen; | |
295 | ||
296 | /* filedescriptors in and out are the same, so it's a socket */ | |
dc1f1948 | 297 | if (active_state->connection_in == active_state->connection_out) |
48e671d5 | 298 | return 1; |
299 | fromlen = sizeof(from); | |
300 | memset(&from, 0, sizeof(from)); | |
dc1f1948 | 301 | if (getpeername(active_state->connection_in, (struct sockaddr *)&from, |
302 | &fromlen) < 0) | |
48e671d5 | 303 | return 0; |
304 | tolen = sizeof(to); | |
305 | memset(&to, 0, sizeof(to)); | |
dc1f1948 | 306 | if (getpeername(active_state->connection_out, (struct sockaddr *)&to, |
307 | &tolen) < 0) | |
48e671d5 | 308 | return 0; |
309 | if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0) | |
310 | return 0; | |
311 | if (from.ss_family != AF_INET && from.ss_family != AF_INET6) | |
312 | return 0; | |
313 | return 1; | |
314 | } | |
315 | ||
762715ce | 316 | /* |
e050d348 | 317 | * Exports an IV from the CipherContext required to export the key |
318 | * state back from the unprivileged child to the privileged parent | |
319 | * process. | |
320 | */ | |
321 | ||
322 | void | |
323 | packet_get_keyiv(int mode, u_char *iv, u_int len) | |
324 | { | |
325 | CipherContext *cc; | |
326 | ||
327 | if (mode == MODE_OUT) | |
dc1f1948 | 328 | cc = &active_state->send_context; |
e050d348 | 329 | else |
dc1f1948 | 330 | cc = &active_state->receive_context; |
e050d348 | 331 | |
332 | cipher_get_keyiv(cc, iv, len); | |
333 | } | |
334 | ||
335 | int | |
336 | packet_get_keycontext(int mode, u_char *dat) | |
337 | { | |
338 | CipherContext *cc; | |
762715ce | 339 | |
e050d348 | 340 | if (mode == MODE_OUT) |
dc1f1948 | 341 | cc = &active_state->send_context; |
e050d348 | 342 | else |
dc1f1948 | 343 | cc = &active_state->receive_context; |
e050d348 | 344 | |
345 | return (cipher_get_keycontext(cc, dat)); | |
346 | } | |
347 | ||
348 | void | |
349 | packet_set_keycontext(int mode, u_char *dat) | |
350 | { | |
351 | CipherContext *cc; | |
762715ce | 352 | |
e050d348 | 353 | if (mode == MODE_OUT) |
dc1f1948 | 354 | cc = &active_state->send_context; |
e050d348 | 355 | else |
dc1f1948 | 356 | cc = &active_state->receive_context; |
e050d348 | 357 | |
358 | cipher_set_keycontext(cc, dat); | |
359 | } | |
360 | ||
361 | int | |
362 | packet_get_keyiv_len(int mode) | |
363 | { | |
364 | CipherContext *cc; | |
365 | ||
366 | if (mode == MODE_OUT) | |
dc1f1948 | 367 | cc = &active_state->send_context; |
e050d348 | 368 | else |
dc1f1948 | 369 | cc = &active_state->receive_context; |
e050d348 | 370 | |
371 | return (cipher_get_keyiv_len(cc)); | |
372 | } | |
a7137f6b | 373 | |
e050d348 | 374 | void |
375 | packet_set_iv(int mode, u_char *dat) | |
376 | { | |
377 | CipherContext *cc; | |
378 | ||
379 | if (mode == MODE_OUT) | |
dc1f1948 | 380 | cc = &active_state->send_context; |
e050d348 | 381 | else |
dc1f1948 | 382 | cc = &active_state->receive_context; |
e050d348 | 383 | |
384 | cipher_set_keyiv(cc, dat); | |
385 | } | |
a7137f6b | 386 | |
e050d348 | 387 | int |
0daa6547 | 388 | packet_get_ssh1_cipher(void) |
e050d348 | 389 | { |
dc1f1948 | 390 | return (cipher_get_number(active_state->receive_context.cipher)); |
e050d348 | 391 | } |
392 | ||
ffd7b36b | 393 | void |
e8e08a80 | 394 | packet_get_state(int mode, u_int32_t *seqnr, u_int64_t *blocks, u_int32_t *packets, |
395 | u_int64_t *bytes) | |
e050d348 | 396 | { |
ffd7b36b | 397 | struct packet_state *state; |
398 | ||
dc1f1948 | 399 | state = (mode == MODE_IN) ? |
400 | &active_state->p_read : &active_state->p_send; | |
e8e08a80 | 401 | if (seqnr) |
402 | *seqnr = state->seqnr; | |
403 | if (blocks) | |
404 | *blocks = state->blocks; | |
405 | if (packets) | |
406 | *packets = state->packets; | |
407 | if (bytes) | |
408 | *bytes = state->bytes; | |
e050d348 | 409 | } |
410 | ||
411 | void | |
e8e08a80 | 412 | packet_set_state(int mode, u_int32_t seqnr, u_int64_t blocks, u_int32_t packets, |
413 | u_int64_t bytes) | |
e050d348 | 414 | { |
ffd7b36b | 415 | struct packet_state *state; |
416 | ||
dc1f1948 | 417 | state = (mode == MODE_IN) ? |
418 | &active_state->p_read : &active_state->p_send; | |
ffd7b36b | 419 | state->seqnr = seqnr; |
420 | state->blocks = blocks; | |
421 | state->packets = packets; | |
e8e08a80 | 422 | state->bytes = bytes; |
e050d348 | 423 | } |
424 | ||
48e671d5 | 425 | /* returns 1 if connection is via ipv4 */ |
426 | ||
427 | int | |
d5bb9418 | 428 | packet_connection_is_ipv4(void) |
48e671d5 | 429 | { |
430 | struct sockaddr_storage to; | |
d45317d8 | 431 | socklen_t tolen = sizeof(to); |
48e671d5 | 432 | |
433 | memset(&to, 0, sizeof(to)); | |
dc1f1948 | 434 | if (getsockname(active_state->connection_out, (struct sockaddr *)&to, |
435 | &tolen) < 0) | |
48e671d5 | 436 | return 0; |
782e2103 | 437 | if (to.ss_family == AF_INET) |
438 | return 1; | |
439 | #ifdef IPV4_IN_IPV6 | |
aff51935 | 440 | if (to.ss_family == AF_INET6 && |
782e2103 | 441 | IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr)) |
442 | return 1; | |
443 | #endif | |
444 | return 0; | |
48e671d5 | 445 | } |
446 | ||
8efc0c15 | 447 | /* Sets the connection into non-blocking mode. */ |
448 | ||
449 | void | |
d5bb9418 | 450 | packet_set_nonblocking(void) |
8efc0c15 | 451 | { |
5260325f | 452 | /* Set the socket into non-blocking mode. */ |
dc1f1948 | 453 | set_nonblock(active_state->connection_in); |
8efc0c15 | 454 | |
dc1f1948 | 455 | if (active_state->connection_out != active_state->connection_in) |
456 | set_nonblock(active_state->connection_out); | |
8efc0c15 | 457 | } |
458 | ||
459 | /* Returns the socket used for reading. */ | |
460 | ||
461 | int | |
d5bb9418 | 462 | packet_get_connection_in(void) |
8efc0c15 | 463 | { |
dc1f1948 | 464 | return active_state->connection_in; |
8efc0c15 | 465 | } |
466 | ||
467 | /* Returns the descriptor used for writing. */ | |
468 | ||
469 | int | |
d5bb9418 | 470 | packet_get_connection_out(void) |
8efc0c15 | 471 | { |
dc1f1948 | 472 | return active_state->connection_out; |
8efc0c15 | 473 | } |
474 | ||
475 | /* Closes the connection and clears and frees internal data structures. */ | |
476 | ||
477 | void | |
d5bb9418 | 478 | packet_close(void) |
8efc0c15 | 479 | { |
dc1f1948 | 480 | if (!active_state->initialized) |
5260325f | 481 | return; |
dc1f1948 | 482 | active_state->initialized = 0; |
483 | if (active_state->connection_in == active_state->connection_out) { | |
484 | shutdown(active_state->connection_out, SHUT_RDWR); | |
485 | close(active_state->connection_out); | |
5260325f | 486 | } else { |
dc1f1948 | 487 | close(active_state->connection_in); |
488 | close(active_state->connection_out); | |
5260325f | 489 | } |
dc1f1948 | 490 | buffer_free(&active_state->input); |
491 | buffer_free(&active_state->output); | |
492 | buffer_free(&active_state->outgoing_packet); | |
493 | buffer_free(&active_state->incoming_packet); | |
494 | if (active_state->compression_buffer_ready) { | |
495 | buffer_free(&active_state->compression_buffer); | |
5260325f | 496 | buffer_compress_uninit(); |
497 | } | |
dc1f1948 | 498 | cipher_cleanup(&active_state->send_context); |
499 | cipher_cleanup(&active_state->receive_context); | |
8efc0c15 | 500 | } |
501 | ||
502 | /* Sets remote side protocol flags. */ | |
503 | ||
504 | void | |
1e3b8b07 | 505 | packet_set_protocol_flags(u_int protocol_flags) |
8efc0c15 | 506 | { |
dc1f1948 | 507 | active_state->remote_protocol_flags = protocol_flags; |
8efc0c15 | 508 | } |
509 | ||
510 | /* Returns the remote protocol flags set earlier by the above function. */ | |
511 | ||
1e3b8b07 | 512 | u_int |
d5bb9418 | 513 | packet_get_protocol_flags(void) |
8efc0c15 | 514 | { |
dc1f1948 | 515 | return active_state->remote_protocol_flags; |
8efc0c15 | 516 | } |
517 | ||
aa3378df | 518 | /* |
519 | * Starts packet compression from the next packet on in both directions. | |
520 | * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip. | |
521 | */ | |
8efc0c15 | 522 | |
396c147e | 523 | static void |
524 | packet_init_compression(void) | |
6ba22c93 | 525 | { |
dc1f1948 | 526 | if (active_state->compression_buffer_ready == 1) |
6ba22c93 | 527 | return; |
dc1f1948 | 528 | active_state->compression_buffer_ready = 1; |
529 | buffer_init(&active_state->compression_buffer); | |
6ba22c93 | 530 | } |
531 | ||
8efc0c15 | 532 | void |
533 | packet_start_compression(int level) | |
534 | { | |
dc1f1948 | 535 | if (active_state->packet_compression && !compat20) |
5260325f | 536 | fatal("Compression already enabled."); |
dc1f1948 | 537 | active_state->packet_compression = 1; |
6ba22c93 | 538 | packet_init_compression(); |
539 | buffer_compress_init_send(level); | |
540 | buffer_compress_init_recv(); | |
8efc0c15 | 541 | } |
542 | ||
aa3378df | 543 | /* |
544 | * Causes any further packets to be encrypted using the given key. The same | |
545 | * key is used for both sending and reception. However, both directions are | |
546 | * encrypted independently of each other. | |
547 | */ | |
9459414c | 548 | |
8efc0c15 | 549 | void |
1e3b8b07 | 550 | packet_set_encryption_key(const u_char *key, u_int keylen, |
94ec8c6b | 551 | int number) |
8efc0c15 | 552 | { |
94ec8c6b | 553 | Cipher *cipher = cipher_by_number(number); |
e1feb9bf | 554 | |
94ec8c6b | 555 | if (cipher == NULL) |
556 | fatal("packet_set_encryption_key: unknown cipher number %d", number); | |
7e7327a1 | 557 | if (keylen < 20) |
94ec8c6b | 558 | fatal("packet_set_encryption_key: keylen too small: %d", keylen); |
9459414c | 559 | if (keylen > SSH_SESSION_KEY_LENGTH) |
560 | fatal("packet_set_encryption_key: keylen too big: %d", keylen); | |
dc1f1948 | 561 | memcpy(active_state->ssh1_key, key, keylen); |
562 | active_state->ssh1_keylen = keylen; | |
563 | cipher_init(&active_state->send_context, cipher, key, keylen, NULL, | |
564 | 0, CIPHER_ENCRYPT); | |
565 | cipher_init(&active_state->receive_context, cipher, key, keylen, NULL, | |
566 | 0, CIPHER_DECRYPT); | |
8efc0c15 | 567 | } |
568 | ||
9459414c | 569 | u_int |
570 | packet_get_encryption_key(u_char *key) | |
571 | { | |
572 | if (key == NULL) | |
dc1f1948 | 573 | return (active_state->ssh1_keylen); |
574 | memcpy(key, active_state->ssh1_key, active_state->ssh1_keylen); | |
575 | return (active_state->ssh1_keylen); | |
9459414c | 576 | } |
577 | ||
08dcb5d7 | 578 | /* Start constructing a packet to send. */ |
8efc0c15 | 579 | void |
08dcb5d7 | 580 | packet_start(u_char type) |
8efc0c15 | 581 | { |
08dcb5d7 | 582 | u_char buf[9]; |
583 | int len; | |
7e7327a1 | 584 | |
12bf85ed | 585 | DBG(debug("packet_start[%d]", type)); |
08dcb5d7 | 586 | len = compat20 ? 6 : 9; |
587 | memset(buf, 0, len - 1); | |
588 | buf[len - 1] = type; | |
dc1f1948 | 589 | buffer_clear(&active_state->outgoing_packet); |
590 | buffer_append(&active_state->outgoing_packet, buf, len); | |
7e7327a1 | 591 | } |
592 | ||
08dcb5d7 | 593 | /* Append payload. */ |
8efc0c15 | 594 | void |
595 | packet_put_char(int value) | |
596 | { | |
5260325f | 597 | char ch = value; |
e1feb9bf | 598 | |
dc1f1948 | 599 | buffer_append(&active_state->outgoing_packet, &ch, 1); |
8efc0c15 | 600 | } |
a7137f6b | 601 | |
8efc0c15 | 602 | void |
1e3b8b07 | 603 | packet_put_int(u_int value) |
8efc0c15 | 604 | { |
dc1f1948 | 605 | buffer_put_int(&active_state->outgoing_packet, value); |
8efc0c15 | 606 | } |
a7137f6b | 607 | |
c6063ed7 | 608 | void |
609 | packet_put_int64(u_int64_t value) | |
610 | { | |
611 | buffer_put_int64(&active_state->outgoing_packet, value); | |
612 | } | |
613 | ||
8efc0c15 | 614 | void |
6c0fa2b1 | 615 | packet_put_string(const void *buf, u_int len) |
8efc0c15 | 616 | { |
dc1f1948 | 617 | buffer_put_string(&active_state->outgoing_packet, buf, len); |
8efc0c15 | 618 | } |
a7137f6b | 619 | |
7e7327a1 | 620 | void |
621 | packet_put_cstring(const char *str) | |
622 | { | |
dc1f1948 | 623 | buffer_put_cstring(&active_state->outgoing_packet, str); |
7e7327a1 | 624 | } |
a7137f6b | 625 | |
7e7327a1 | 626 | void |
6c0fa2b1 | 627 | packet_put_raw(const void *buf, u_int len) |
7e7327a1 | 628 | { |
dc1f1948 | 629 | buffer_append(&active_state->outgoing_packet, buf, len); |
7e7327a1 | 630 | } |
a7137f6b | 631 | |
8efc0c15 | 632 | void |
5260325f | 633 | packet_put_bignum(BIGNUM * value) |
8efc0c15 | 634 | { |
dc1f1948 | 635 | buffer_put_bignum(&active_state->outgoing_packet, value); |
8efc0c15 | 636 | } |
a7137f6b | 637 | |
7e7327a1 | 638 | void |
639 | packet_put_bignum2(BIGNUM * value) | |
640 | { | |
dc1f1948 | 641 | buffer_put_bignum2(&active_state->outgoing_packet, value); |
7e7327a1 | 642 | } |
8efc0c15 | 643 | |
aa3378df | 644 | /* |
645 | * Finalizes and sends the packet. If the encryption key has been set, | |
646 | * encrypts the packet before sending. | |
647 | */ | |
5260325f | 648 | |
396c147e | 649 | static void |
5ca51e19 | 650 | packet_send1(void) |
8efc0c15 | 651 | { |
a318bbf4 | 652 | u_char buf[8], *cp; |
5260325f | 653 | int i, padding, len; |
1e3b8b07 | 654 | u_int checksum; |
ca75d7de | 655 | u_int32_t rnd = 0; |
5260325f | 656 | |
aa3378df | 657 | /* |
658 | * If using packet compression, compress the payload of the outgoing | |
659 | * packet. | |
660 | */ | |
dc1f1948 | 661 | if (active_state->packet_compression) { |
662 | buffer_clear(&active_state->compression_buffer); | |
5260325f | 663 | /* Skip padding. */ |
dc1f1948 | 664 | buffer_consume(&active_state->outgoing_packet, 8); |
5260325f | 665 | /* padding */ |
dc1f1948 | 666 | buffer_append(&active_state->compression_buffer, |
667 | "\0\0\0\0\0\0\0\0", 8); | |
668 | buffer_compress(&active_state->outgoing_packet, | |
669 | &active_state->compression_buffer); | |
670 | buffer_clear(&active_state->outgoing_packet); | |
671 | buffer_append(&active_state->outgoing_packet, | |
672 | buffer_ptr(&active_state->compression_buffer), | |
673 | buffer_len(&active_state->compression_buffer)); | |
5260325f | 674 | } |
675 | /* Compute packet length without padding (add checksum, remove padding). */ | |
dc1f1948 | 676 | len = buffer_len(&active_state->outgoing_packet) + 4 - 8; |
5260325f | 677 | |
1d1ffb87 | 678 | /* Insert padding. Initialized to zero in packet_start1() */ |
5260325f | 679 | padding = 8 - len % 8; |
dc1f1948 | 680 | if (!active_state->send_context.plaintext) { |
681 | cp = buffer_ptr(&active_state->outgoing_packet); | |
5260325f | 682 | for (i = 0; i < padding; i++) { |
683 | if (i % 4 == 0) | |
ca75d7de | 684 | rnd = arc4random(); |
685 | cp[7 - i] = rnd & 0xff; | |
686 | rnd >>= 8; | |
5260325f | 687 | } |
688 | } | |
dc1f1948 | 689 | buffer_consume(&active_state->outgoing_packet, 8 - padding); |
5260325f | 690 | |
691 | /* Add check bytes. */ | |
dc1f1948 | 692 | checksum = ssh_crc32(buffer_ptr(&active_state->outgoing_packet), |
693 | buffer_len(&active_state->outgoing_packet)); | |
51e7a012 | 694 | put_u32(buf, checksum); |
dc1f1948 | 695 | buffer_append(&active_state->outgoing_packet, buf, 4); |
8efc0c15 | 696 | |
697 | #ifdef PACKET_DEBUG | |
5260325f | 698 | fprintf(stderr, "packet_send plain: "); |
dc1f1948 | 699 | buffer_dump(&active_state->outgoing_packet); |
8efc0c15 | 700 | #endif |
701 | ||
5260325f | 702 | /* Append to output. */ |
51e7a012 | 703 | put_u32(buf, len); |
dc1f1948 | 704 | buffer_append(&active_state->output, buf, 4); |
705 | cp = buffer_append_space(&active_state->output, | |
706 | buffer_len(&active_state->outgoing_packet)); | |
707 | cipher_crypt(&active_state->send_context, cp, | |
708 | buffer_ptr(&active_state->outgoing_packet), | |
709 | buffer_len(&active_state->outgoing_packet)); | |
5260325f | 710 | |
8efc0c15 | 711 | #ifdef PACKET_DEBUG |
5260325f | 712 | fprintf(stderr, "encrypted: "); |
dc1f1948 | 713 | buffer_dump(&active_state->output); |
8efc0c15 | 714 | #endif |
dc1f1948 | 715 | active_state->p_send.packets++; |
716 | active_state->p_send.bytes += len + | |
717 | buffer_len(&active_state->outgoing_packet); | |
718 | buffer_clear(&active_state->outgoing_packet); | |
8efc0c15 | 719 | |
aa3378df | 720 | /* |
7b9b0103 | 721 | * Note that the packet is now only buffered in output. It won't be |
aa3378df | 722 | * actually sent until packet_write_wait or packet_write_poll is |
723 | * called. | |
724 | */ | |
8efc0c15 | 725 | } |
726 | ||
e050d348 | 727 | void |
d1ac6175 | 728 | set_newkeys(int mode) |
729 | { | |
730 | Enc *enc; | |
731 | Mac *mac; | |
732 | Comp *comp; | |
733 | CipherContext *cc; | |
ffd7b36b | 734 | u_int64_t *max_blocks; |
ca75d7de | 735 | int crypt_type; |
d1ac6175 | 736 | |
a77673cc | 737 | debug2("set_newkeys: mode %d", mode); |
d1ac6175 | 738 | |
3ee832e5 | 739 | if (mode == MODE_OUT) { |
dc1f1948 | 740 | cc = &active_state->send_context; |
ca75d7de | 741 | crypt_type = CIPHER_ENCRYPT; |
dc1f1948 | 742 | active_state->p_send.packets = active_state->p_send.blocks = 0; |
743 | max_blocks = &active_state->max_blocks_out; | |
3ee832e5 | 744 | } else { |
dc1f1948 | 745 | cc = &active_state->receive_context; |
ca75d7de | 746 | crypt_type = CIPHER_DECRYPT; |
dc1f1948 | 747 | active_state->p_read.packets = active_state->p_read.blocks = 0; |
748 | max_blocks = &active_state->max_blocks_in; | |
3ee832e5 | 749 | } |
dc1f1948 | 750 | if (active_state->newkeys[mode] != NULL) { |
a77673cc | 751 | debug("set_newkeys: rekeying"); |
3ee832e5 | 752 | cipher_cleanup(cc); |
dc1f1948 | 753 | enc = &active_state->newkeys[mode]->enc; |
754 | mac = &active_state->newkeys[mode]->mac; | |
755 | comp = &active_state->newkeys[mode]->comp; | |
f444d0f8 | 756 | mac_clear(mac); |
a7ca6275 | 757 | xfree(enc->name); |
758 | xfree(enc->iv); | |
759 | xfree(enc->key); | |
760 | xfree(mac->name); | |
761 | xfree(mac->key); | |
762 | xfree(comp->name); | |
dc1f1948 | 763 | xfree(active_state->newkeys[mode]); |
d1ac6175 | 764 | } |
dc1f1948 | 765 | active_state->newkeys[mode] = kex_get_newkeys(mode); |
766 | if (active_state->newkeys[mode] == NULL) | |
d1ac6175 | 767 | fatal("newkeys: no keys for mode %d", mode); |
dc1f1948 | 768 | enc = &active_state->newkeys[mode]->enc; |
769 | mac = &active_state->newkeys[mode]->mac; | |
770 | comp = &active_state->newkeys[mode]->comp; | |
f444d0f8 | 771 | if (mac_init(mac) == 0) |
d1ac6175 | 772 | mac->enabled = 1; |
773 | DBG(debug("cipher_init_context: %d", mode)); | |
3ee832e5 | 774 | cipher_init(cc, enc->cipher, enc->key, enc->key_len, |
ca75d7de | 775 | enc->iv, enc->block_size, crypt_type); |
e050d348 | 776 | /* Deleting the keys does not gain extra security */ |
777 | /* memset(enc->iv, 0, enc->block_size); | |
a3de8da1 | 778 | memset(enc->key, 0, enc->key_len); |
779 | memset(mac->key, 0, mac->key_len); */ | |
07200973 | 780 | if ((comp->type == COMP_ZLIB || |
dc1f1948 | 781 | (comp->type == COMP_DELAYED && |
782 | active_state->after_authentication)) && comp->enabled == 0) { | |
6ba22c93 | 783 | packet_init_compression(); |
784 | if (mode == MODE_OUT) | |
785 | buffer_compress_init_send(6); | |
786 | else | |
787 | buffer_compress_init_recv(); | |
d1ac6175 | 788 | comp->enabled = 1; |
d1ac6175 | 789 | } |
40729edd | 790 | /* |
791 | * The 2^(blocksize*2) limit is too expensive for 3DES, | |
792 | * blowfish, etc, so enforce a 1GB limit for small blocksizes. | |
793 | */ | |
794 | if (enc->block_size >= 16) | |
795 | *max_blocks = (u_int64_t)1 << (enc->block_size*2); | |
796 | else | |
797 | *max_blocks = ((u_int64_t)1 << 30) / enc->block_size; | |
dc1f1948 | 798 | if (active_state->rekey_limit) |
799 | *max_blocks = MIN(*max_blocks, | |
800 | active_state->rekey_limit / enc->block_size); | |
d1ac6175 | 801 | } |
802 | ||
07200973 | 803 | /* |
804 | * Delayed compression for SSH2 is enabled after authentication: | |
0e13ec0f | 805 | * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent, |
07200973 | 806 | * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received. |
807 | */ | |
808 | static void | |
809 | packet_enable_delayed_compress(void) | |
810 | { | |
811 | Comp *comp = NULL; | |
812 | int mode; | |
813 | ||
814 | /* | |
815 | * Remember that we are past the authentication step, so rekeying | |
816 | * with COMP_DELAYED will turn on compression immediately. | |
817 | */ | |
dc1f1948 | 818 | active_state->after_authentication = 1; |
07200973 | 819 | for (mode = 0; mode < MODE_MAX; mode++) { |
a29c9898 | 820 | /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */ |
dc1f1948 | 821 | if (active_state->newkeys[mode] == NULL) |
a29c9898 | 822 | continue; |
dc1f1948 | 823 | comp = &active_state->newkeys[mode]->comp; |
07200973 | 824 | if (comp && !comp->enabled && comp->type == COMP_DELAYED) { |
4145cbfa | 825 | packet_init_compression(); |
07200973 | 826 | if (mode == MODE_OUT) |
827 | buffer_compress_init_send(6); | |
828 | else | |
829 | buffer_compress_init_recv(); | |
830 | comp->enabled = 1; | |
831 | } | |
832 | } | |
833 | } | |
834 | ||
7e7327a1 | 835 | /* |
836 | * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) | |
837 | */ | |
396c147e | 838 | static void |
ffd7b36b | 839 | packet_send2_wrapped(void) |
7e7327a1 | 840 | { |
a318bbf4 | 841 | u_char type, *cp, *macbuf = NULL; |
b4b701be | 842 | u_char padlen, pad; |
1e3b8b07 | 843 | u_int packet_length = 0; |
b4b701be | 844 | u_int i, len; |
ca75d7de | 845 | u_int32_t rnd = 0; |
7e7327a1 | 846 | Enc *enc = NULL; |
847 | Mac *mac = NULL; | |
848 | Comp *comp = NULL; | |
849 | int block_size; | |
850 | ||
dc1f1948 | 851 | if (active_state->newkeys[MODE_OUT] != NULL) { |
852 | enc = &active_state->newkeys[MODE_OUT]->enc; | |
853 | mac = &active_state->newkeys[MODE_OUT]->mac; | |
854 | comp = &active_state->newkeys[MODE_OUT]->comp; | |
7e7327a1 | 855 | } |
3ee832e5 | 856 | block_size = enc ? enc->block_size : 8; |
7e7327a1 | 857 | |
dc1f1948 | 858 | cp = buffer_ptr(&active_state->outgoing_packet); |
a318bbf4 | 859 | type = cp[5]; |
7e7327a1 | 860 | |
861 | #ifdef PACKET_DEBUG | |
862 | fprintf(stderr, "plain: "); | |
dc1f1948 | 863 | buffer_dump(&active_state->outgoing_packet); |
7e7327a1 | 864 | #endif |
865 | ||
866 | if (comp && comp->enabled) { | |
dc1f1948 | 867 | len = buffer_len(&active_state->outgoing_packet); |
7e7327a1 | 868 | /* skip header, compress only payload */ |
dc1f1948 | 869 | buffer_consume(&active_state->outgoing_packet, 5); |
870 | buffer_clear(&active_state->compression_buffer); | |
871 | buffer_compress(&active_state->outgoing_packet, | |
872 | &active_state->compression_buffer); | |
873 | buffer_clear(&active_state->outgoing_packet); | |
874 | buffer_append(&active_state->outgoing_packet, "\0\0\0\0\0", 5); | |
875 | buffer_append(&active_state->outgoing_packet, | |
876 | buffer_ptr(&active_state->compression_buffer), | |
877 | buffer_len(&active_state->compression_buffer)); | |
7e7327a1 | 878 | DBG(debug("compression: raw %d compressed %d", len, |
dc1f1948 | 879 | buffer_len(&active_state->outgoing_packet))); |
7e7327a1 | 880 | } |
881 | ||
882 | /* sizeof (packet_len + pad_len + payload) */ | |
dc1f1948 | 883 | len = buffer_len(&active_state->outgoing_packet); |
7e7327a1 | 884 | |
885 | /* | |
886 | * calc size of padding, alloc space, get random data, | |
887 | * minimum padding is 4 bytes | |
888 | */ | |
889 | padlen = block_size - (len % block_size); | |
890 | if (padlen < 4) | |
891 | padlen += block_size; | |
dc1f1948 | 892 | if (active_state->extra_pad) { |
b4b701be | 893 | /* will wrap if extra_pad+padlen > 255 */ |
dc1f1948 | 894 | active_state->extra_pad = |
895 | roundup(active_state->extra_pad, block_size); | |
896 | pad = active_state->extra_pad - | |
897 | ((len + padlen) % active_state->extra_pad); | |
a49dfdec | 898 | debug3("packet_send2: adding %d (len %d padlen %d extra_pad %d)", |
dc1f1948 | 899 | pad, len, padlen, active_state->extra_pad); |
b4b701be | 900 | padlen += pad; |
dc1f1948 | 901 | active_state->extra_pad = 0; |
b4b701be | 902 | } |
dc1f1948 | 903 | cp = buffer_append_space(&active_state->outgoing_packet, padlen); |
904 | if (enc && !active_state->send_context.plaintext) { | |
1d1ffb87 | 905 | /* random padding */ |
7e7327a1 | 906 | for (i = 0; i < padlen; i++) { |
907 | if (i % 4 == 0) | |
ca75d7de | 908 | rnd = arc4random(); |
909 | cp[i] = rnd & 0xff; | |
910 | rnd >>= 8; | |
7e7327a1 | 911 | } |
1d1ffb87 | 912 | } else { |
913 | /* clear padding */ | |
914 | memset(cp, 0, padlen); | |
7e7327a1 | 915 | } |
916 | /* packet_length includes payload, padding and padding length field */ | |
dc1f1948 | 917 | packet_length = buffer_len(&active_state->outgoing_packet) - 4; |
918 | cp = buffer_ptr(&active_state->outgoing_packet); | |
51e7a012 | 919 | put_u32(cp, packet_length); |
a318bbf4 | 920 | cp[4] = padlen; |
7e7327a1 | 921 | DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen)); |
922 | ||
923 | /* compute MAC over seqnr and packet(length fields, payload, padding) */ | |
924 | if (mac && mac->enabled) { | |
dc1f1948 | 925 | macbuf = mac_compute(mac, active_state->p_send.seqnr, |
926 | buffer_ptr(&active_state->outgoing_packet), | |
927 | buffer_len(&active_state->outgoing_packet)); | |
928 | DBG(debug("done calc MAC out #%d", active_state->p_send.seqnr)); | |
7e7327a1 | 929 | } |
930 | /* encrypt packet and append to output buffer. */ | |
dc1f1948 | 931 | cp = buffer_append_space(&active_state->output, |
932 | buffer_len(&active_state->outgoing_packet)); | |
933 | cipher_crypt(&active_state->send_context, cp, | |
934 | buffer_ptr(&active_state->outgoing_packet), | |
935 | buffer_len(&active_state->outgoing_packet)); | |
7e7327a1 | 936 | /* append unencrypted MAC */ |
937 | if (mac && mac->enabled) | |
dc1f1948 | 938 | buffer_append(&active_state->output, macbuf, mac->mac_len); |
7e7327a1 | 939 | #ifdef PACKET_DEBUG |
940 | fprintf(stderr, "encrypted: "); | |
dc1f1948 | 941 | buffer_dump(&active_state->output); |
7e7327a1 | 942 | #endif |
6ae2364d | 943 | /* increment sequence number for outgoing packets */ |
dc1f1948 | 944 | if (++active_state->p_send.seqnr == 0) |
bbe88b6d | 945 | logit("outgoing seqnr wraps around"); |
dc1f1948 | 946 | if (++active_state->p_send.packets == 0) |
ffd7b36b | 947 | if (!(datafellows & SSH_BUG_NOREKEY)) |
948 | fatal("XXX too many packets with same key"); | |
dc1f1948 | 949 | active_state->p_send.blocks += (packet_length + 4) / block_size; |
950 | active_state->p_send.bytes += packet_length + 4; | |
951 | buffer_clear(&active_state->outgoing_packet); | |
7e7327a1 | 952 | |
d1ac6175 | 953 | if (type == SSH2_MSG_NEWKEYS) |
954 | set_newkeys(MODE_OUT); | |
dc1f1948 | 955 | else if (type == SSH2_MSG_USERAUTH_SUCCESS && active_state->server_side) |
07200973 | 956 | packet_enable_delayed_compress(); |
7e7327a1 | 957 | } |
958 | ||
ffd7b36b | 959 | static void |
960 | packet_send2(void) | |
961 | { | |
ffd7b36b | 962 | struct packet *p; |
963 | u_char type, *cp; | |
964 | ||
dc1f1948 | 965 | cp = buffer_ptr(&active_state->outgoing_packet); |
ffd7b36b | 966 | type = cp[5]; |
967 | ||
968 | /* during rekeying we can only send key exchange messages */ | |
6a49252d | 969 | if (active_state->rekeying) { |
ffd7b36b | 970 | if (!((type >= SSH2_MSG_TRANSPORT_MIN) && |
971 | (type <= SSH2_MSG_TRANSPORT_MAX))) { | |
972 | debug("enqueue packet: %u", type); | |
973 | p = xmalloc(sizeof(*p)); | |
974 | p->type = type; | |
dc1f1948 | 975 | memcpy(&p->payload, &active_state->outgoing_packet, |
976 | sizeof(Buffer)); | |
977 | buffer_init(&active_state->outgoing_packet); | |
978 | TAILQ_INSERT_TAIL(&active_state->outgoing, p, next); | |
ffd7b36b | 979 | return; |
980 | } | |
981 | } | |
982 | ||
983 | /* rekeying starts with sending KEXINIT */ | |
984 | if (type == SSH2_MSG_KEXINIT) | |
6a49252d | 985 | active_state->rekeying = 1; |
ffd7b36b | 986 | |
987 | packet_send2_wrapped(); | |
988 | ||
989 | /* after a NEWKEYS message we can send the complete queue */ | |
990 | if (type == SSH2_MSG_NEWKEYS) { | |
6a49252d | 991 | active_state->rekeying = 0; |
dc1f1948 | 992 | while ((p = TAILQ_FIRST(&active_state->outgoing))) { |
ffd7b36b | 993 | type = p->type; |
994 | debug("dequeue packet: %u", type); | |
dc1f1948 | 995 | buffer_free(&active_state->outgoing_packet); |
996 | memcpy(&active_state->outgoing_packet, &p->payload, | |
ffd7b36b | 997 | sizeof(Buffer)); |
dc1f1948 | 998 | TAILQ_REMOVE(&active_state->outgoing, p, next); |
ffd7b36b | 999 | xfree(p); |
1000 | packet_send2_wrapped(); | |
1001 | } | |
1002 | } | |
1003 | } | |
1004 | ||
7e7327a1 | 1005 | void |
d5bb9418 | 1006 | packet_send(void) |
7e7327a1 | 1007 | { |
08dcb5d7 | 1008 | if (compat20) |
7e7327a1 | 1009 | packet_send2(); |
1010 | else | |
1011 | packet_send1(); | |
1012 | DBG(debug("packet_send done")); | |
1013 | } | |
1014 | ||
aa3378df | 1015 | /* |
1016 | * Waits until a packet has been received, and returns its type. Note that | |
1017 | * no other data is processed until this returns, so this function should not | |
1018 | * be used during the interactive session. | |
1019 | */ | |
8efc0c15 | 1020 | |
1021 | int | |
54a5250f | 1022 | packet_read_seqnr(u_int32_t *seqnr_p) |
8efc0c15 | 1023 | { |
d0137ef8 | 1024 | int type, len, ret, ms_remain, cont; |
20e04e90 | 1025 | fd_set *setp; |
5260325f | 1026 | char buf[8192]; |
bc2d97c8 | 1027 | struct timeval timeout, start, *timeoutp = NULL; |
5260325f | 1028 | |
849d3ceb | 1029 | DBG(debug("packet_read()")); |
1030 | ||
dc1f1948 | 1031 | setp = (fd_set *)xcalloc(howmany(active_state->connection_in + 1, |
1032 | NFDBITS), sizeof(fd_mask)); | |
20e04e90 | 1033 | |
5260325f | 1034 | /* Since we are blocking, ensure that all written packets have been sent. */ |
1035 | packet_write_wait(); | |
1036 | ||
1037 | /* Stay in the loop until we have received a complete packet. */ | |
1038 | for (;;) { | |
1039 | /* Try to read a packet from the buffer. */ | |
54a5250f | 1040 | type = packet_read_poll_seqnr(seqnr_p); |
08dcb5d7 | 1041 | if (!compat20 && ( |
1d1ffb87 | 1042 | type == SSH_SMSG_SUCCESS |
5260325f | 1043 | || type == SSH_SMSG_FAILURE |
1044 | || type == SSH_CMSG_EOF | |
1d1ffb87 | 1045 | || type == SSH_CMSG_EXIT_CONFIRMATION)) |
95500969 | 1046 | packet_check_eom(); |
5260325f | 1047 | /* If we got a packet, return it. */ |
20e04e90 | 1048 | if (type != SSH_MSG_NONE) { |
1049 | xfree(setp); | |
5260325f | 1050 | return type; |
20e04e90 | 1051 | } |
aa3378df | 1052 | /* |
1053 | * Otherwise, wait for some data to arrive, add it to the | |
1054 | * buffer, and try again. | |
1055 | */ | |
dc1f1948 | 1056 | memset(setp, 0, howmany(active_state->connection_in + 1, |
1057 | NFDBITS) * sizeof(fd_mask)); | |
1058 | FD_SET(active_state->connection_in, setp); | |
aa3378df | 1059 | |
dc1f1948 | 1060 | if (active_state->packet_timeout_ms > 0) { |
1061 | ms_remain = active_state->packet_timeout_ms; | |
bc2d97c8 | 1062 | timeoutp = &timeout; |
1063 | } | |
5260325f | 1064 | /* Wait for some data to arrive. */ |
bc2d97c8 | 1065 | for (;;) { |
dc1f1948 | 1066 | if (active_state->packet_timeout_ms != -1) { |
bc2d97c8 | 1067 | ms_to_timeval(&timeout, ms_remain); |
1068 | gettimeofday(&start, NULL); | |
1069 | } | |
dc1f1948 | 1070 | if ((ret = select(active_state->connection_in + 1, setp, |
1071 | NULL, NULL, timeoutp)) >= 0) | |
bc2d97c8 | 1072 | break; |
018fda87 | 1073 | if (errno != EAGAIN && errno != EINTR && |
1074 | errno != EWOULDBLOCK) | |
bc2d97c8 | 1075 | break; |
dc1f1948 | 1076 | if (active_state->packet_timeout_ms == -1) |
bc2d97c8 | 1077 | continue; |
1078 | ms_subtract_diff(&start, &ms_remain); | |
1079 | if (ms_remain <= 0) { | |
1080 | ret = 0; | |
1081 | break; | |
1082 | } | |
1083 | } | |
1084 | if (ret == 0) { | |
1085 | logit("Connection to %.200s timed out while " | |
1086 | "waiting to read", get_remote_ipaddr()); | |
1087 | cleanup_exit(255); | |
1088 | } | |
5260325f | 1089 | /* Read data from the socket. */ |
d0137ef8 | 1090 | do { |
1091 | cont = 0; | |
1092 | len = roaming_read(active_state->connection_in, buf, | |
1093 | sizeof(buf), &cont); | |
1094 | } while (len == 0 && cont); | |
89cafde6 | 1095 | if (len == 0) { |
bbe88b6d | 1096 | logit("Connection closed by %.200s", get_remote_ipaddr()); |
2362db19 | 1097 | cleanup_exit(255); |
89cafde6 | 1098 | } |
5260325f | 1099 | if (len < 0) |
1100 | fatal("Read from socket failed: %.100s", strerror(errno)); | |
1101 | /* Append it to the buffer. */ | |
1102 | packet_process_incoming(buf, len); | |
1103 | } | |
1104 | /* NOTREACHED */ | |
8efc0c15 | 1105 | } |
1106 | ||
24ca6821 | 1107 | int |
54a5250f | 1108 | packet_read(void) |
24ca6821 | 1109 | { |
54a5250f | 1110 | return packet_read_seqnr(NULL); |
24ca6821 | 1111 | } |
1112 | ||
aa3378df | 1113 | /* |
1114 | * Waits until a packet has been received, verifies that its type matches | |
1115 | * that given, and gives a fatal error and exits if there is a mismatch. | |
1116 | */ | |
8efc0c15 | 1117 | |
1118 | void | |
54a5250f | 1119 | packet_read_expect(int expected_type) |
8efc0c15 | 1120 | { |
5260325f | 1121 | int type; |
8efc0c15 | 1122 | |
54a5250f | 1123 | type = packet_read(); |
5260325f | 1124 | if (type != expected_type) |
1125 | packet_disconnect("Protocol error: expected packet type %d, got %d", | |
7e7327a1 | 1126 | expected_type, type); |
8efc0c15 | 1127 | } |
1128 | ||
1129 | /* Checks if a full packet is available in the data received so far via | |
5260325f | 1130 | * packet_process_incoming. If so, reads the packet; otherwise returns |
1131 | * SSH_MSG_NONE. This does not wait for data from the connection. | |
1132 | * | |
aacfb17b | 1133 | * SSH_MSG_DISCONNECT is handled specially here. Also, |
1134 | * SSH_MSG_IGNORE messages are skipped by this function and are never returned | |
1135 | * to higher levels. | |
5260325f | 1136 | */ |
8efc0c15 | 1137 | |
396c147e | 1138 | static int |
54a5250f | 1139 | packet_read_poll1(void) |
8efc0c15 | 1140 | { |
1e3b8b07 | 1141 | u_int len, padded_len; |
a318bbf4 | 1142 | u_char *cp, type; |
1e3b8b07 | 1143 | u_int checksum, stored_checksum; |
5260325f | 1144 | |
5260325f | 1145 | /* Check if input size is less than minimum packet size. */ |
dc1f1948 | 1146 | if (buffer_len(&active_state->input) < 4 + 8) |
5260325f | 1147 | return SSH_MSG_NONE; |
1148 | /* Get length of incoming packet. */ | |
dc1f1948 | 1149 | cp = buffer_ptr(&active_state->input); |
51e7a012 | 1150 | len = get_u32(cp); |
5260325f | 1151 | if (len < 1 + 2 + 2 || len > 256 * 1024) |
2fe3c2db | 1152 | packet_disconnect("Bad packet length %u.", len); |
5260325f | 1153 | padded_len = (len + 8) & ~7; |
1154 | ||
1155 | /* Check if the packet has been entirely received. */ | |
dc1f1948 | 1156 | if (buffer_len(&active_state->input) < 4 + padded_len) |
5260325f | 1157 | return SSH_MSG_NONE; |
1158 | ||
1159 | /* The entire packet is in buffer. */ | |
1160 | ||
1161 | /* Consume packet length. */ | |
dc1f1948 | 1162 | buffer_consume(&active_state->input, 4); |
5260325f | 1163 | |
08dcb5d7 | 1164 | /* |
1165 | * Cryptographic attack detector for ssh | |
1166 | * (C)1998 CORE-SDI, Buenos Aires Argentina | |
1167 | * Ariel Futoransky(futo@core-sdi.com) | |
1168 | */ | |
dc1f1948 | 1169 | if (!active_state->receive_context.plaintext) { |
1170 | switch (detect_attack(buffer_ptr(&active_state->input), | |
1171 | padded_len)) { | |
f0d0e025 | 1172 | case DEATTACK_DETECTED: |
1173 | packet_disconnect("crc32 compensation attack: " | |
1174 | "network attack detected"); | |
1175 | case DEATTACK_DOS_DETECTED: | |
1176 | packet_disconnect("deattack denial of " | |
1177 | "service detected"); | |
1178 | } | |
1179 | } | |
08dcb5d7 | 1180 | |
1181 | /* Decrypt data to incoming_packet. */ | |
dc1f1948 | 1182 | buffer_clear(&active_state->incoming_packet); |
1183 | cp = buffer_append_space(&active_state->incoming_packet, padded_len); | |
1184 | cipher_crypt(&active_state->receive_context, cp, | |
1185 | buffer_ptr(&active_state->input), padded_len); | |
08dcb5d7 | 1186 | |
dc1f1948 | 1187 | buffer_consume(&active_state->input, padded_len); |
8efc0c15 | 1188 | |
1189 | #ifdef PACKET_DEBUG | |
5260325f | 1190 | fprintf(stderr, "read_poll plain: "); |
dc1f1948 | 1191 | buffer_dump(&active_state->incoming_packet); |
8efc0c15 | 1192 | #endif |
5260325f | 1193 | |
1194 | /* Compute packet checksum. */ | |
dc1f1948 | 1195 | checksum = ssh_crc32(buffer_ptr(&active_state->incoming_packet), |
1196 | buffer_len(&active_state->incoming_packet) - 4); | |
5260325f | 1197 | |
1198 | /* Skip padding. */ | |
dc1f1948 | 1199 | buffer_consume(&active_state->incoming_packet, 8 - len % 8); |
5260325f | 1200 | |
1201 | /* Test check bytes. */ | |
dc1f1948 | 1202 | if (len != buffer_len(&active_state->incoming_packet)) |
24ca6821 | 1203 | packet_disconnect("packet_read_poll1: len %d != buffer_len %d.", |
dc1f1948 | 1204 | len, buffer_len(&active_state->incoming_packet)); |
5260325f | 1205 | |
dc1f1948 | 1206 | cp = (u_char *)buffer_ptr(&active_state->incoming_packet) + len - 4; |
51e7a012 | 1207 | stored_checksum = get_u32(cp); |
5260325f | 1208 | if (checksum != stored_checksum) |
1209 | packet_disconnect("Corrupted check bytes on input."); | |
dc1f1948 | 1210 | buffer_consume_end(&active_state->incoming_packet, 4); |
1211 | ||
1212 | if (active_state->packet_compression) { | |
1213 | buffer_clear(&active_state->compression_buffer); | |
1214 | buffer_uncompress(&active_state->incoming_packet, | |
1215 | &active_state->compression_buffer); | |
1216 | buffer_clear(&active_state->incoming_packet); | |
1217 | buffer_append(&active_state->incoming_packet, | |
1218 | buffer_ptr(&active_state->compression_buffer), | |
1219 | buffer_len(&active_state->compression_buffer)); | |
5260325f | 1220 | } |
dc1f1948 | 1221 | active_state->p_read.packets++; |
1222 | active_state->p_read.bytes += padded_len + 4; | |
1223 | type = buffer_get_char(&active_state->incoming_packet); | |
750bbb35 | 1224 | if (type < SSH_MSG_MIN || type > SSH_MSG_MAX) |
1225 | packet_disconnect("Invalid ssh1 packet type: %d", type); | |
08dcb5d7 | 1226 | return type; |
5260325f | 1227 | } |
1228 | ||
396c147e | 1229 | static int |
54a5250f | 1230 | packet_read_poll2(u_int32_t *seqnr_p) |
7e7327a1 | 1231 | { |
1e3b8b07 | 1232 | u_int padlen, need; |
a318bbf4 | 1233 | u_char *macbuf, *cp, type; |
2ceb8101 | 1234 | u_int maclen, block_size; |
7e7327a1 | 1235 | Enc *enc = NULL; |
1236 | Mac *mac = NULL; | |
1237 | Comp *comp = NULL; | |
1238 | ||
dc1f1948 | 1239 | if (active_state->packet_discard) |
608bcf58 | 1240 | return SSH_MSG_NONE; |
1241 | ||
dc1f1948 | 1242 | if (active_state->newkeys[MODE_IN] != NULL) { |
1243 | enc = &active_state->newkeys[MODE_IN]->enc; | |
1244 | mac = &active_state->newkeys[MODE_IN]->mac; | |
1245 | comp = &active_state->newkeys[MODE_IN]->comp; | |
7e7327a1 | 1246 | } |
1247 | maclen = mac && mac->enabled ? mac->mac_len : 0; | |
3ee832e5 | 1248 | block_size = enc ? enc->block_size : 8; |
7e7327a1 | 1249 | |
dc1f1948 | 1250 | if (active_state->packlen == 0) { |
7e7327a1 | 1251 | /* |
1252 | * check if input size is less than the cipher block size, | |
1253 | * decrypt first block and extract length of incoming packet | |
1254 | */ | |
dc1f1948 | 1255 | if (buffer_len(&active_state->input) < block_size) |
7e7327a1 | 1256 | return SSH_MSG_NONE; |
dc1f1948 | 1257 | buffer_clear(&active_state->incoming_packet); |
1258 | cp = buffer_append_space(&active_state->incoming_packet, | |
7e7327a1 | 1259 | block_size); |
dc1f1948 | 1260 | cipher_crypt(&active_state->receive_context, cp, |
1261 | buffer_ptr(&active_state->input), block_size); | |
1262 | cp = buffer_ptr(&active_state->incoming_packet); | |
1263 | active_state->packlen = get_u32(cp); | |
1264 | if (active_state->packlen < 1 + 4 || | |
1265 | active_state->packlen > PACKET_MAX_SIZE) { | |
9adbb4a4 | 1266 | #ifdef PACKET_DEBUG |
dc1f1948 | 1267 | buffer_dump(&active_state->incoming_packet); |
9adbb4a4 | 1268 | #endif |
dc1f1948 | 1269 | logit("Bad packet length %u.", active_state->packlen); |
1270 | packet_start_discard(enc, mac, active_state->packlen, | |
608bcf58 | 1271 | PACKET_MAX_SIZE); |
1272 | return SSH_MSG_NONE; | |
7e7327a1 | 1273 | } |
dc1f1948 | 1274 | DBG(debug("input: packet len %u", active_state->packlen+4)); |
1275 | buffer_consume(&active_state->input, block_size); | |
7e7327a1 | 1276 | } |
1277 | /* we have a partial packet of block_size bytes */ | |
dc1f1948 | 1278 | need = 4 + active_state->packlen - block_size; |
7e7327a1 | 1279 | DBG(debug("partial packet %d, need %d, maclen %d", block_size, |
1280 | need, maclen)); | |
66af1c21 | 1281 | if (need % block_size != 0) { |
1282 | logit("padding error: need %d block %d mod %d", | |
7e7327a1 | 1283 | need, block_size, need % block_size); |
dc1f1948 | 1284 | packet_start_discard(enc, mac, active_state->packlen, |
608bcf58 | 1285 | PACKET_MAX_SIZE - block_size); |
1286 | return SSH_MSG_NONE; | |
66af1c21 | 1287 | } |
7e7327a1 | 1288 | /* |
1289 | * check if the entire packet has been received and | |
1290 | * decrypt into incoming_packet | |
1291 | */ | |
dc1f1948 | 1292 | if (buffer_len(&active_state->input) < need + maclen) |
7e7327a1 | 1293 | return SSH_MSG_NONE; |
1294 | #ifdef PACKET_DEBUG | |
1295 | fprintf(stderr, "read_poll enc/full: "); | |
dc1f1948 | 1296 | buffer_dump(&active_state->input); |
7e7327a1 | 1297 | #endif |
dc1f1948 | 1298 | cp = buffer_append_space(&active_state->incoming_packet, need); |
1299 | cipher_crypt(&active_state->receive_context, cp, | |
1300 | buffer_ptr(&active_state->input), need); | |
1301 | buffer_consume(&active_state->input, need); | |
7e7327a1 | 1302 | /* |
1303 | * compute MAC over seqnr and packet, | |
1304 | * increment sequence number for incoming packet | |
1305 | */ | |
6ae2364d | 1306 | if (mac && mac->enabled) { |
dc1f1948 | 1307 | macbuf = mac_compute(mac, active_state->p_read.seqnr, |
1308 | buffer_ptr(&active_state->incoming_packet), | |
1309 | buffer_len(&active_state->incoming_packet)); | |
1310 | if (memcmp(macbuf, buffer_ptr(&active_state->input), | |
1311 | mac->mac_len) != 0) { | |
608bcf58 | 1312 | logit("Corrupted MAC on input."); |
1313 | if (need > PACKET_MAX_SIZE) | |
1314 | fatal("internal error need %d", need); | |
dc1f1948 | 1315 | packet_start_discard(enc, mac, active_state->packlen, |
608bcf58 | 1316 | PACKET_MAX_SIZE - need); |
1317 | return SSH_MSG_NONE; | |
1318 | } | |
1319 | ||
dc1f1948 | 1320 | DBG(debug("MAC #%d ok", active_state->p_read.seqnr)); |
1321 | buffer_consume(&active_state->input, mac->mac_len); | |
7e7327a1 | 1322 | } |
608bcf58 | 1323 | /* XXX now it's safe to use fatal/packet_disconnect */ |
24ca6821 | 1324 | if (seqnr_p != NULL) |
dc1f1948 | 1325 | *seqnr_p = active_state->p_read.seqnr; |
1326 | if (++active_state->p_read.seqnr == 0) | |
bbe88b6d | 1327 | logit("incoming seqnr wraps around"); |
dc1f1948 | 1328 | if (++active_state->p_read.packets == 0) |
ffd7b36b | 1329 | if (!(datafellows & SSH_BUG_NOREKEY)) |
1330 | fatal("XXX too many packets with same key"); | |
dc1f1948 | 1331 | active_state->p_read.blocks += (active_state->packlen + 4) / block_size; |
1332 | active_state->p_read.bytes += active_state->packlen + 4; | |
7e7327a1 | 1333 | |
1334 | /* get padlen */ | |
dc1f1948 | 1335 | cp = buffer_ptr(&active_state->incoming_packet); |
a318bbf4 | 1336 | padlen = cp[4]; |
7e7327a1 | 1337 | DBG(debug("input: padlen %d", padlen)); |
1338 | if (padlen < 4) | |
1339 | packet_disconnect("Corrupted padlen %d on input.", padlen); | |
1340 | ||
1341 | /* skip packet size + padlen, discard padding */ | |
dc1f1948 | 1342 | buffer_consume(&active_state->incoming_packet, 4 + 1); |
1343 | buffer_consume_end(&active_state->incoming_packet, padlen); | |
7e7327a1 | 1344 | |
dc1f1948 | 1345 | DBG(debug("input: len before de-compress %d", |
1346 | buffer_len(&active_state->incoming_packet))); | |
7e7327a1 | 1347 | if (comp && comp->enabled) { |
dc1f1948 | 1348 | buffer_clear(&active_state->compression_buffer); |
1349 | buffer_uncompress(&active_state->incoming_packet, | |
1350 | &active_state->compression_buffer); | |
1351 | buffer_clear(&active_state->incoming_packet); | |
1352 | buffer_append(&active_state->incoming_packet, | |
1353 | buffer_ptr(&active_state->compression_buffer), | |
1354 | buffer_len(&active_state->compression_buffer)); | |
e1feb9bf | 1355 | DBG(debug("input: len after de-compress %d", |
dc1f1948 | 1356 | buffer_len(&active_state->incoming_packet))); |
7e7327a1 | 1357 | } |
1358 | /* | |
1359 | * get packet type, implies consume. | |
1360 | * return length of payload (without type field) | |
1361 | */ | |
dc1f1948 | 1362 | type = buffer_get_char(&active_state->incoming_packet); |
750bbb35 | 1363 | if (type < SSH2_MSG_MIN || type >= SSH2_MSG_LOCAL_MIN) |
1364 | packet_disconnect("Invalid ssh2 packet type: %d", type); | |
d1ac6175 | 1365 | if (type == SSH2_MSG_NEWKEYS) |
1366 | set_newkeys(MODE_IN); | |
dc1f1948 | 1367 | else if (type == SSH2_MSG_USERAUTH_SUCCESS && |
1368 | !active_state->server_side) | |
07200973 | 1369 | packet_enable_delayed_compress(); |
7e7327a1 | 1370 | #ifdef PACKET_DEBUG |
12bf85ed | 1371 | fprintf(stderr, "read/plain[%d]:\r\n", type); |
dc1f1948 | 1372 | buffer_dump(&active_state->incoming_packet); |
7e7327a1 | 1373 | #endif |
08dcb5d7 | 1374 | /* reset for next packet */ |
dc1f1948 | 1375 | active_state->packlen = 0; |
08dcb5d7 | 1376 | return type; |
7e7327a1 | 1377 | } |
1378 | ||
1379 | int | |
54a5250f | 1380 | packet_read_poll_seqnr(u_int32_t *seqnr_p) |
7e7327a1 | 1381 | { |
0bc50167 | 1382 | u_int reason, seqnr; |
08dcb5d7 | 1383 | u_char type; |
7e7327a1 | 1384 | char *msg; |
7e7327a1 | 1385 | |
08dcb5d7 | 1386 | for (;;) { |
1387 | if (compat20) { | |
54a5250f | 1388 | type = packet_read_poll2(seqnr_p); |
2abb1ef5 | 1389 | if (type) { |
dc1f1948 | 1390 | active_state->keep_alive_timeouts = 0; |
7e7327a1 | 1391 | DBG(debug("received packet type %d", type)); |
2abb1ef5 | 1392 | } |
6aacefa7 | 1393 | switch (type) { |
aacfb17b | 1394 | case SSH2_MSG_IGNORE: |
ac47b626 | 1395 | debug3("Received SSH2_MSG_IGNORE"); |
aacfb17b | 1396 | break; |
7e7327a1 | 1397 | case SSH2_MSG_DEBUG: |
1398 | packet_get_char(); | |
1399 | msg = packet_get_string(NULL); | |
1400 | debug("Remote: %.900s", msg); | |
1401 | xfree(msg); | |
1402 | msg = packet_get_string(NULL); | |
1403 | xfree(msg); | |
1404 | break; | |
1405 | case SSH2_MSG_DISCONNECT: | |
1406 | reason = packet_get_int(); | |
1407 | msg = packet_get_string(NULL); | |
bbe88b6d | 1408 | logit("Received disconnect from %s: %u: %.400s", |
0bc50167 | 1409 | get_remote_ipaddr(), reason, msg); |
7e7327a1 | 1410 | xfree(msg); |
2362db19 | 1411 | cleanup_exit(255); |
7e7327a1 | 1412 | break; |
5a5f4c37 | 1413 | case SSH2_MSG_UNIMPLEMENTED: |
1414 | seqnr = packet_get_int(); | |
0bc50167 | 1415 | debug("Received SSH2_MSG_UNIMPLEMENTED for %u", |
1416 | seqnr); | |
aacfb17b | 1417 | break; |
7e7327a1 | 1418 | default: |
1419 | return type; | |
2b87da3b | 1420 | } |
7e7327a1 | 1421 | } else { |
54a5250f | 1422 | type = packet_read_poll1(); |
6aacefa7 | 1423 | switch (type) { |
7e7327a1 | 1424 | case SSH_MSG_IGNORE: |
1425 | break; | |
1426 | case SSH_MSG_DEBUG: | |
1427 | msg = packet_get_string(NULL); | |
1428 | debug("Remote: %.900s", msg); | |
1429 | xfree(msg); | |
1430 | break; | |
1431 | case SSH_MSG_DISCONNECT: | |
1432 | msg = packet_get_string(NULL); | |
bbe88b6d | 1433 | logit("Received disconnect from %s: %.400s", |
0bc50167 | 1434 | get_remote_ipaddr(), msg); |
2362db19 | 1435 | cleanup_exit(255); |
7e7327a1 | 1436 | break; |
1437 | default: | |
08dcb5d7 | 1438 | if (type) |
7e7327a1 | 1439 | DBG(debug("received packet type %d", type)); |
1440 | return type; | |
2b87da3b | 1441 | } |
7e7327a1 | 1442 | } |
1443 | } | |
1444 | } | |
1445 | ||
24ca6821 | 1446 | int |
54a5250f | 1447 | packet_read_poll(void) |
24ca6821 | 1448 | { |
54a5250f | 1449 | return packet_read_poll_seqnr(NULL); |
24ca6821 | 1450 | } |
1451 | ||
aa3378df | 1452 | /* |
1453 | * Buffers the given amount of input characters. This is intended to be used | |
1454 | * together with packet_read_poll. | |
1455 | */ | |
8efc0c15 | 1456 | |
1457 | void | |
1e3b8b07 | 1458 | packet_process_incoming(const char *buf, u_int len) |
8efc0c15 | 1459 | { |
dc1f1948 | 1460 | if (active_state->packet_discard) { |
1461 | active_state->keep_alive_timeouts = 0; /* ?? */ | |
1462 | if (len >= active_state->packet_discard) | |
608bcf58 | 1463 | packet_stop_discard(); |
dc1f1948 | 1464 | active_state->packet_discard -= len; |
608bcf58 | 1465 | return; |
1466 | } | |
dc1f1948 | 1467 | buffer_append(&active_state->input, buf, len); |
8efc0c15 | 1468 | } |
1469 | ||
1470 | /* Returns a character from the packet. */ | |
1471 | ||
1e3b8b07 | 1472 | u_int |
d5bb9418 | 1473 | packet_get_char(void) |
8efc0c15 | 1474 | { |
5260325f | 1475 | char ch; |
e1feb9bf | 1476 | |
dc1f1948 | 1477 | buffer_get(&active_state->incoming_packet, &ch, 1); |
1e3b8b07 | 1478 | return (u_char) ch; |
8efc0c15 | 1479 | } |
1480 | ||
1481 | /* Returns an integer from the packet data. */ | |
1482 | ||
1e3b8b07 | 1483 | u_int |
d5bb9418 | 1484 | packet_get_int(void) |
8efc0c15 | 1485 | { |
dc1f1948 | 1486 | return buffer_get_int(&active_state->incoming_packet); |
8efc0c15 | 1487 | } |
1488 | ||
c6063ed7 | 1489 | /* Returns an 64 bit integer from the packet data. */ |
1490 | ||
1491 | u_int64_t | |
1492 | packet_get_int64(void) | |
1493 | { | |
1494 | return buffer_get_int64(&active_state->incoming_packet); | |
1495 | } | |
1496 | ||
aa3378df | 1497 | /* |
1498 | * Returns an arbitrary precision integer from the packet data. The integer | |
1499 | * must have been initialized before this call. | |
1500 | */ | |
8efc0c15 | 1501 | |
1502 | void | |
20b279e6 | 1503 | packet_get_bignum(BIGNUM * value) |
8efc0c15 | 1504 | { |
dc1f1948 | 1505 | buffer_get_bignum(&active_state->incoming_packet, value); |
8efc0c15 | 1506 | } |
1507 | ||
7e7327a1 | 1508 | void |
20b279e6 | 1509 | packet_get_bignum2(BIGNUM * value) |
7e7327a1 | 1510 | { |
dc1f1948 | 1511 | buffer_get_bignum2(&active_state->incoming_packet, value); |
7e7327a1 | 1512 | } |
1513 | ||
6c0fa2b1 | 1514 | void * |
2ceb8101 | 1515 | packet_get_raw(u_int *length_ptr) |
7e7327a1 | 1516 | { |
dc1f1948 | 1517 | u_int bytes = buffer_len(&active_state->incoming_packet); |
e1feb9bf | 1518 | |
7e7327a1 | 1519 | if (length_ptr != NULL) |
1520 | *length_ptr = bytes; | |
dc1f1948 | 1521 | return buffer_ptr(&active_state->incoming_packet); |
7e7327a1 | 1522 | } |
1523 | ||
6ae2364d | 1524 | int |
1525 | packet_remaining(void) | |
1526 | { | |
dc1f1948 | 1527 | return buffer_len(&active_state->incoming_packet); |
6ae2364d | 1528 | } |
1529 | ||
aa3378df | 1530 | /* |
1531 | * Returns a string from the packet data. The string is allocated using | |
1532 | * xmalloc; it is the responsibility of the calling program to free it when | |
1533 | * no longer needed. The length_ptr argument may be NULL, or point to an | |
1534 | * integer into which the length of the string is stored. | |
1535 | */ | |
8efc0c15 | 1536 | |
6c0fa2b1 | 1537 | void * |
1e3b8b07 | 1538 | packet_get_string(u_int *length_ptr) |
8efc0c15 | 1539 | { |
dc1f1948 | 1540 | return buffer_get_string(&active_state->incoming_packet, length_ptr); |
17f02f0a | 1541 | } |
1542 | ||
1543 | void * | |
1544 | packet_get_string_ptr(u_int *length_ptr) | |
1545 | { | |
dc1f1948 | 1546 | return buffer_get_string_ptr(&active_state->incoming_packet, length_ptr); |
8efc0c15 | 1547 | } |
1548 | ||
aa3378df | 1549 | /* |
1550 | * Sends a diagnostic message from the server to the client. This message | |
1551 | * can be sent at any time (but not while constructing another message). The | |
1552 | * message is printed immediately, but only if the client is being executed | |
1553 | * in verbose mode. These messages are primarily intended to ease debugging | |
1554 | * authentication problems. The length of the formatted message must not | |
1555 | * exceed 1024 bytes. This will automatically call packet_write_wait. | |
1556 | */ | |
8efc0c15 | 1557 | |
1558 | void | |
5260325f | 1559 | packet_send_debug(const char *fmt,...) |
8efc0c15 | 1560 | { |
5260325f | 1561 | char buf[1024]; |
1562 | va_list args; | |
1563 | ||
f72fc97f | 1564 | if (compat20 && (datafellows & SSH_BUG_DEBUG)) |
1565 | return; | |
1566 | ||
5260325f | 1567 | va_start(args, fmt); |
1568 | vsnprintf(buf, sizeof(buf), fmt, args); | |
1569 | va_end(args); | |
1570 | ||
c4bc58eb | 1571 | if (compat20) { |
1572 | packet_start(SSH2_MSG_DEBUG); | |
1573 | packet_put_char(0); /* bool: always display */ | |
1574 | packet_put_cstring(buf); | |
1575 | packet_put_cstring(""); | |
1576 | } else { | |
1577 | packet_start(SSH_MSG_DEBUG); | |
1578 | packet_put_cstring(buf); | |
1579 | } | |
5260325f | 1580 | packet_send(); |
1581 | packet_write_wait(); | |
8efc0c15 | 1582 | } |
1583 | ||
aa3378df | 1584 | /* |
1585 | * Logs the error plus constructs and sends a disconnect packet, closes the | |
1586 | * connection, and exits. This function never returns. The error message | |
1587 | * should not contain a newline. The length of the formatted message must | |
1588 | * not exceed 1024 bytes. | |
1589 | */ | |
8efc0c15 | 1590 | |
1591 | void | |
5260325f | 1592 | packet_disconnect(const char *fmt,...) |
1593 | { | |
1594 | char buf[1024]; | |
1595 | va_list args; | |
1596 | static int disconnecting = 0; | |
e1feb9bf | 1597 | |
5260325f | 1598 | if (disconnecting) /* Guard against recursive invocations. */ |
1599 | fatal("packet_disconnect called recursively."); | |
1600 | disconnecting = 1; | |
1601 | ||
aa3378df | 1602 | /* |
1603 | * Format the message. Note that the caller must make sure the | |
1604 | * message is of limited size. | |
1605 | */ | |
5260325f | 1606 | va_start(args, fmt); |
1607 | vsnprintf(buf, sizeof(buf), fmt, args); | |
1608 | va_end(args); | |
1609 | ||
2ccb7bde | 1610 | /* Display the error locally */ |
bbe88b6d | 1611 | logit("Disconnecting: %.100s", buf); |
2ccb7bde | 1612 | |
5260325f | 1613 | /* Send the disconnect message to the other side, and wait for it to get sent. */ |
7e7327a1 | 1614 | if (compat20) { |
1615 | packet_start(SSH2_MSG_DISCONNECT); | |
1616 | packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR); | |
1617 | packet_put_cstring(buf); | |
1618 | packet_put_cstring(""); | |
1619 | } else { | |
1620 | packet_start(SSH_MSG_DISCONNECT); | |
449c5ba5 | 1621 | packet_put_cstring(buf); |
7e7327a1 | 1622 | } |
5260325f | 1623 | packet_send(); |
1624 | packet_write_wait(); | |
1625 | ||
1626 | /* Stop listening for connections. */ | |
d6746a0b | 1627 | channel_close_all(); |
5260325f | 1628 | |
1629 | /* Close the connection. */ | |
1630 | packet_close(); | |
2362db19 | 1631 | cleanup_exit(255); |
8efc0c15 | 1632 | } |
1633 | ||
aa3378df | 1634 | /* Checks if there is any buffered output, and tries to write some of the output. */ |
8efc0c15 | 1635 | |
1636 | void | |
d5bb9418 | 1637 | packet_write_poll(void) |
8efc0c15 | 1638 | { |
dc1f1948 | 1639 | int len = buffer_len(&active_state->output); |
d0137ef8 | 1640 | int cont; |
e1feb9bf | 1641 | |
5260325f | 1642 | if (len > 0) { |
d0137ef8 | 1643 | cont = 0; |
1644 | len = roaming_write(active_state->connection_out, | |
1645 | buffer_ptr(&active_state->output), len, &cont); | |
d38d9a80 | 1646 | if (len == -1) { |
018fda87 | 1647 | if (errno == EINTR || errno == EAGAIN || |
1648 | errno == EWOULDBLOCK) | |
5260325f | 1649 | return; |
d38d9a80 | 1650 | fatal("Write failed: %.100s", strerror(errno)); |
5260325f | 1651 | } |
d0137ef8 | 1652 | if (len == 0 && !cont) |
d38d9a80 | 1653 | fatal("Write connection closed"); |
dc1f1948 | 1654 | buffer_consume(&active_state->output, len); |
5260325f | 1655 | } |
8efc0c15 | 1656 | } |
1657 | ||
aa3378df | 1658 | /* |
1659 | * Calls packet_write_poll repeatedly until all pending output data has been | |
1660 | * written. | |
1661 | */ | |
8efc0c15 | 1662 | |
1663 | void | |
d5bb9418 | 1664 | packet_write_wait(void) |
8efc0c15 | 1665 | { |
20e04e90 | 1666 | fd_set *setp; |
bc2d97c8 | 1667 | int ret, ms_remain; |
1668 | struct timeval start, timeout, *timeoutp = NULL; | |
20e04e90 | 1669 | |
dc1f1948 | 1670 | setp = (fd_set *)xcalloc(howmany(active_state->connection_out + 1, |
1671 | NFDBITS), sizeof(fd_mask)); | |
5260325f | 1672 | packet_write_poll(); |
1673 | while (packet_have_data_to_write()) { | |
dc1f1948 | 1674 | memset(setp, 0, howmany(active_state->connection_out + 1, |
1675 | NFDBITS) * sizeof(fd_mask)); | |
1676 | FD_SET(active_state->connection_out, setp); | |
bc2d97c8 | 1677 | |
dc1f1948 | 1678 | if (active_state->packet_timeout_ms > 0) { |
1679 | ms_remain = active_state->packet_timeout_ms; | |
bc2d97c8 | 1680 | timeoutp = &timeout; |
1681 | } | |
1682 | for (;;) { | |
dc1f1948 | 1683 | if (active_state->packet_timeout_ms != -1) { |
bc2d97c8 | 1684 | ms_to_timeval(&timeout, ms_remain); |
1685 | gettimeofday(&start, NULL); | |
1686 | } | |
dc1f1948 | 1687 | if ((ret = select(active_state->connection_out + 1, |
1688 | NULL, setp, NULL, timeoutp)) >= 0) | |
bc2d97c8 | 1689 | break; |
018fda87 | 1690 | if (errno != EAGAIN && errno != EINTR && |
1691 | errno != EWOULDBLOCK) | |
bc2d97c8 | 1692 | break; |
dc1f1948 | 1693 | if (active_state->packet_timeout_ms == -1) |
bc2d97c8 | 1694 | continue; |
1695 | ms_subtract_diff(&start, &ms_remain); | |
1696 | if (ms_remain <= 0) { | |
1697 | ret = 0; | |
1698 | break; | |
1699 | } | |
1700 | } | |
1701 | if (ret == 0) { | |
1702 | logit("Connection to %.200s timed out while " | |
1703 | "waiting to write", get_remote_ipaddr()); | |
1704 | cleanup_exit(255); | |
1705 | } | |
5260325f | 1706 | packet_write_poll(); |
1707 | } | |
20e04e90 | 1708 | xfree(setp); |
8efc0c15 | 1709 | } |
1710 | ||
1711 | /* Returns true if there is buffered data to write to the connection. */ | |
1712 | ||
1713 | int | |
d5bb9418 | 1714 | packet_have_data_to_write(void) |
8efc0c15 | 1715 | { |
dc1f1948 | 1716 | return buffer_len(&active_state->output) != 0; |
8efc0c15 | 1717 | } |
1718 | ||
1719 | /* Returns true if there is not too much data to write to the connection. */ | |
1720 | ||
1721 | int | |
d5bb9418 | 1722 | packet_not_very_much_data_to_write(void) |
8efc0c15 | 1723 | { |
dc1f1948 | 1724 | if (active_state->interactive_mode) |
1725 | return buffer_len(&active_state->output) < 16384; | |
5260325f | 1726 | else |
dc1f1948 | 1727 | return buffer_len(&active_state->output) < 128 * 1024; |
8efc0c15 | 1728 | } |
1729 | ||
9e637910 | 1730 | static void |
48f636b2 | 1731 | packet_set_tos(int interactive) |
1732 | { | |
00df6acd | 1733 | #if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) |
48f636b2 | 1734 | int tos = interactive ? IPTOS_LOWDELAY : IPTOS_THROUGHPUT; |
1735 | ||
1736 | if (!packet_connection_is_on_socket() || | |
1737 | !packet_connection_is_ipv4()) | |
1738 | return; | |
dc1f1948 | 1739 | if (setsockopt(active_state->connection_in, IPPROTO_IP, IP_TOS, &tos, |
48f636b2 | 1740 | sizeof(tos)) < 0) |
1741 | error("setsockopt IP_TOS %d: %.100s:", | |
1742 | tos, strerror(errno)); | |
4d0cb2e5 | 1743 | #endif |
00df6acd | 1744 | } |
48f636b2 | 1745 | |
8efc0c15 | 1746 | /* Informs that the current session is interactive. Sets IP flags for that. */ |
1747 | ||
1748 | void | |
b5c334cc | 1749 | packet_set_interactive(int interactive) |
8efc0c15 | 1750 | { |
6a49252d | 1751 | if (active_state->set_interactive_called) |
b5c334cc | 1752 | return; |
6a49252d | 1753 | active_state->set_interactive_called = 1; |
b5c334cc | 1754 | |
5260325f | 1755 | /* Record that we are in interactive mode. */ |
dc1f1948 | 1756 | active_state->interactive_mode = interactive; |
5260325f | 1757 | |
48e671d5 | 1758 | /* Only set socket options if using a socket. */ |
1759 | if (!packet_connection_is_on_socket()) | |
aceb0423 | 1760 | return; |
dc1f1948 | 1761 | set_nodelay(active_state->connection_in); |
48f636b2 | 1762 | packet_set_tos(interactive); |
8efc0c15 | 1763 | } |
1764 | ||
1765 | /* Returns true if the current connection is interactive. */ | |
1766 | ||
1767 | int | |
d5bb9418 | 1768 | packet_is_interactive(void) |
8efc0c15 | 1769 | { |
dc1f1948 | 1770 | return active_state->interactive_mode; |
8efc0c15 | 1771 | } |
9d6b7add | 1772 | |
f6be21a0 | 1773 | int |
a27002e5 | 1774 | packet_set_maxsize(u_int s) |
9d6b7add | 1775 | { |
6a49252d | 1776 | if (active_state->set_maxsize_called) { |
bbe88b6d | 1777 | logit("packet_set_maxsize: called twice: old %d new %d", |
dc1f1948 | 1778 | active_state->max_packet_size, s); |
5260325f | 1779 | return -1; |
1780 | } | |
1781 | if (s < 4 * 1024 || s > 1024 * 1024) { | |
bbe88b6d | 1782 | logit("packet_set_maxsize: bad size %d", s); |
5260325f | 1783 | return -1; |
1784 | } | |
6a49252d | 1785 | active_state->set_maxsize_called = 1; |
76735fe3 | 1786 | debug("packet_set_maxsize: setting to %d", s); |
dc1f1948 | 1787 | active_state->max_packet_size = s; |
5260325f | 1788 | return s; |
9d6b7add | 1789 | } |
a6215e53 | 1790 | |
dc1f1948 | 1791 | int |
1792 | packet_inc_alive_timeouts(void) | |
1793 | { | |
1794 | return ++active_state->keep_alive_timeouts; | |
1795 | } | |
1796 | ||
1797 | void | |
1798 | packet_set_alive_timeouts(int ka) | |
1799 | { | |
1800 | active_state->keep_alive_timeouts = ka; | |
1801 | } | |
1802 | ||
1803 | u_int | |
1804 | packet_get_maxsize(void) | |
1805 | { | |
1806 | return active_state->max_packet_size; | |
1807 | } | |
1808 | ||
b4b701be | 1809 | /* roundup current message to pad bytes */ |
1810 | void | |
1811 | packet_add_padding(u_char pad) | |
1812 | { | |
dc1f1948 | 1813 | active_state->extra_pad = pad; |
b4b701be | 1814 | } |
1815 | ||
a6215e53 | 1816 | /* |
1817 | * 9.2. Ignored Data Message | |
cd332296 | 1818 | * |
a6215e53 | 1819 | * byte SSH_MSG_IGNORE |
1820 | * string data | |
cd332296 | 1821 | * |
a6215e53 | 1822 | * All implementations MUST understand (and ignore) this message at any |
1823 | * time (after receiving the protocol version). No implementation is | |
1824 | * required to send them. This message can be used as an additional | |
1825 | * protection measure against advanced traffic analysis techniques. | |
1826 | */ | |
95ce5599 | 1827 | void |
1828 | packet_send_ignore(int nbytes) | |
1829 | { | |
ca75d7de | 1830 | u_int32_t rnd = 0; |
95ce5599 | 1831 | int i; |
1832 | ||
1833 | packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE); | |
a6215e53 | 1834 | packet_put_int(nbytes); |
184eed6a | 1835 | for (i = 0; i < nbytes; i++) { |
a6215e53 | 1836 | if (i % 4 == 0) |
ca75d7de | 1837 | rnd = arc4random(); |
febd6f21 | 1838 | packet_put_char((u_char)rnd & 0xff); |
ca75d7de | 1839 | rnd >>= 8; |
a6215e53 | 1840 | } |
1841 | } | |
ffd7b36b | 1842 | |
f6be21a0 | 1843 | #define MAX_PACKETS (1U<<31) |
ffd7b36b | 1844 | int |
1845 | packet_need_rekeying(void) | |
1846 | { | |
1847 | if (datafellows & SSH_BUG_NOREKEY) | |
1848 | return 0; | |
1849 | return | |
dc1f1948 | 1850 | (active_state->p_send.packets > MAX_PACKETS) || |
1851 | (active_state->p_read.packets > MAX_PACKETS) || | |
1852 | (active_state->max_blocks_out && | |
1853 | (active_state->p_send.blocks > active_state->max_blocks_out)) || | |
1854 | (active_state->max_blocks_in && | |
1855 | (active_state->p_read.blocks > active_state->max_blocks_in)); | |
ffd7b36b | 1856 | } |
1857 | ||
1858 | void | |
1859 | packet_set_rekey_limit(u_int32_t bytes) | |
1860 | { | |
dc1f1948 | 1861 | active_state->rekey_limit = bytes; |
ffd7b36b | 1862 | } |
07200973 | 1863 | |
1864 | void | |
1865 | packet_set_server(void) | |
1866 | { | |
dc1f1948 | 1867 | active_state->server_side = 1; |
07200973 | 1868 | } |
1869 | ||
1870 | void | |
1871 | packet_set_authenticated(void) | |
1872 | { | |
dc1f1948 | 1873 | active_state->after_authentication = 1; |
1874 | } | |
1875 | ||
1876 | void * | |
1877 | packet_get_input(void) | |
1878 | { | |
1879 | return (void *)&active_state->input; | |
1880 | } | |
1881 | ||
1882 | void * | |
1883 | packet_get_output(void) | |
1884 | { | |
1885 | return (void *)&active_state->output; | |
1886 | } | |
1887 | ||
1888 | void * | |
1889 | packet_get_newkeys(int mode) | |
1890 | { | |
1891 | return (void *)active_state->newkeys[mode]; | |
07200973 | 1892 | } |
5d82ad35 | 1893 | |
1894 | /* | |
1895 | * Save the state for the real connection, and use a separate state when | |
1896 | * resuming a suspended connection. | |
1897 | */ | |
1898 | void | |
1899 | packet_backup_state(void) | |
1900 | { | |
1901 | struct session_state *tmp; | |
1902 | ||
1903 | close(active_state->connection_in); | |
1904 | active_state->connection_in = -1; | |
1905 | close(active_state->connection_out); | |
1906 | active_state->connection_out = -1; | |
1907 | if (backup_state) | |
1908 | tmp = backup_state; | |
1909 | else | |
1910 | tmp = alloc_session_state(); | |
1911 | backup_state = active_state; | |
1912 | active_state = tmp; | |
1913 | } | |
1914 | ||
1915 | /* | |
1916 | * Swap in the old state when resuming a connecion. | |
1917 | */ | |
1918 | void | |
1919 | packet_restore_state(void) | |
1920 | { | |
1921 | struct session_state *tmp; | |
1922 | void *buf; | |
1923 | u_int len; | |
1924 | ||
1925 | tmp = backup_state; | |
1926 | backup_state = active_state; | |
1927 | active_state = tmp; | |
1928 | active_state->connection_in = backup_state->connection_in; | |
1929 | backup_state->connection_in = -1; | |
1930 | active_state->connection_out = backup_state->connection_out; | |
1931 | backup_state->connection_out = -1; | |
1932 | len = buffer_len(&backup_state->input); | |
1933 | if (len > 0) { | |
1934 | buf = buffer_ptr(&backup_state->input); | |
1935 | buffer_append(&active_state->input, buf, len); | |
1936 | buffer_clear(&backup_state->input); | |
1937 | add_recv_bytes(len); | |
1938 | } | |
1939 | } |