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8efc0c15 | 1 | /* |
5260325f | 2 | * Author: Tatu Ylonen <ylo@cs.hut.fi> |
5260325f | 3 | * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland |
4 | * All rights reserved | |
5260325f | 5 | * This file contains code implementing the packet protocol and communication |
6 | * with the other side. This same code is used both on client and server side. | |
7e7327a1 | 7 | * |
bcbf86ec | 8 | * As far as I am concerned, the code I have written for this software |
9 | * can be used freely for any purpose. Any derived versions of this | |
10 | * software must be clearly marked as such, and if the derived work is | |
11 | * incompatible with the protocol description in the RFC file, it must be | |
12 | * called by a name other than "ssh" or "Secure Shell". | |
13 | * | |
14 | * | |
7e7327a1 | 15 | * SSH2 packet format added by Markus Friedl. |
a96070d4 | 16 | * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved. |
bcbf86ec | 17 | * |
18 | * Redistribution and use in source and binary forms, with or without | |
19 | * modification, are permitted provided that the following conditions | |
20 | * are met: | |
21 | * 1. Redistributions of source code must retain the above copyright | |
22 | * notice, this list of conditions and the following disclaimer. | |
23 | * 2. Redistributions in binary form must reproduce the above copyright | |
24 | * notice, this list of conditions and the following disclaimer in the | |
25 | * documentation and/or other materials provided with the distribution. | |
7e7327a1 | 26 | * |
bcbf86ec | 27 | * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR |
28 | * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES | |
29 | * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. | |
30 | * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, | |
31 | * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | |
32 | * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, | |
33 | * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY | |
34 | * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT | |
35 | * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF | |
36 | * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. | |
5260325f | 37 | */ |
8efc0c15 | 38 | |
39 | #include "includes.h" | |
a3dcf543 | 40 | |
2f5b2528 | 41 | #include "openbsd-compat/sys-queue.h" |
a3dcf543 | 42 | #include <netinet/in_systm.h> |
43 | #include <netinet/ip.h> | |
8efc0c15 | 44 | |
45 | #include "xmalloc.h" | |
46 | #include "buffer.h" | |
47 | #include "packet.h" | |
48 | #include "bufaux.h" | |
8efc0c15 | 49 | #include "crc32.h" |
8efc0c15 | 50 | #include "getput.h" |
51 | ||
52 | #include "compress.h" | |
53 | #include "deattack.h" | |
a5efa1bb | 54 | #include "channels.h" |
8efc0c15 | 55 | |
7e7327a1 | 56 | #include "compat.h" |
42f11eb2 | 57 | #include "ssh1.h" |
7e7327a1 | 58 | #include "ssh2.h" |
59 | ||
94ec8c6b | 60 | #include "cipher.h" |
7e7327a1 | 61 | #include "kex.h" |
b2552997 | 62 | #include "mac.h" |
42f11eb2 | 63 | #include "log.h" |
64 | #include "canohost.h" | |
2ac91be1 | 65 | #include "misc.h" |
9459414c | 66 | #include "ssh.h" |
7e7327a1 | 67 | |
68 | #ifdef PACKET_DEBUG | |
69 | #define DBG(x) x | |
70 | #else | |
71 | #define DBG(x) | |
72 | #endif | |
73 | ||
aa3378df | 74 | /* |
75 | * This variable contains the file descriptors used for communicating with | |
76 | * the other side. connection_in is used for reading; connection_out for | |
77 | * writing. These can be the same descriptor, in which case it is assumed to | |
78 | * be a socket. | |
79 | */ | |
8efc0c15 | 80 | static int connection_in = -1; |
81 | static int connection_out = -1; | |
82 | ||
8efc0c15 | 83 | /* Protocol flags for the remote side. */ |
1e3b8b07 | 84 | static u_int remote_protocol_flags = 0; |
8efc0c15 | 85 | |
86 | /* Encryption context for receiving data. This is only used for decryption. */ | |
87 | static CipherContext receive_context; | |
5260325f | 88 | |
89 | /* Encryption context for sending data. This is only used for encryption. */ | |
8efc0c15 | 90 | static CipherContext send_context; |
91 | ||
92 | /* Buffer for raw input data from the socket. */ | |
e050d348 | 93 | Buffer input; |
8efc0c15 | 94 | |
95 | /* Buffer for raw output data going to the socket. */ | |
e050d348 | 96 | Buffer output; |
8efc0c15 | 97 | |
98 | /* Buffer for the partial outgoing packet being constructed. */ | |
99 | static Buffer outgoing_packet; | |
100 | ||
101 | /* Buffer for the incoming packet currently being processed. */ | |
102 | static Buffer incoming_packet; | |
103 | ||
104 | /* Scratch buffer for packet compression/decompression. */ | |
105 | static Buffer compression_buffer; | |
6ba22c93 | 106 | static int compression_buffer_ready = 0; |
8efc0c15 | 107 | |
108 | /* Flag indicating whether packet compression/decompression is enabled. */ | |
109 | static int packet_compression = 0; | |
110 | ||
9d6b7add | 111 | /* default maximum packet size */ |
a27002e5 | 112 | u_int max_packet_size = 32768; |
9d6b7add | 113 | |
8efc0c15 | 114 | /* Flag indicating whether this module has been initialized. */ |
115 | static int initialized = 0; | |
116 | ||
117 | /* Set to true if the connection is interactive. */ | |
118 | static int interactive_mode = 0; | |
119 | ||
07200973 | 120 | /* Set to true if we are the server side. */ |
121 | static int server_side = 0; | |
122 | ||
123 | /* Set to true if we are authenticated. */ | |
124 | static int after_authentication = 0; | |
125 | ||
7e7327a1 | 126 | /* Session key information for Encryption and MAC */ |
d1ac6175 | 127 | Newkeys *newkeys[MODE_MAX]; |
ffd7b36b | 128 | static struct packet_state { |
129 | u_int32_t seqnr; | |
130 | u_int32_t packets; | |
131 | u_int64_t blocks; | |
132 | } p_read, p_send; | |
133 | ||
134 | static u_int64_t max_blocks_in, max_blocks_out; | |
135 | static u_int32_t rekey_limit; | |
7e7327a1 | 136 | |
9459414c | 137 | /* Session key for protocol v1 */ |
138 | static u_char ssh1_key[SSH_SESSION_KEY_LENGTH]; | |
139 | static u_int ssh1_keylen; | |
140 | ||
b4b701be | 141 | /* roundup current message to extra_pad bytes */ |
142 | static u_char extra_pad = 0; | |
143 | ||
ffd7b36b | 144 | struct packet { |
145 | TAILQ_ENTRY(packet) next; | |
146 | u_char type; | |
147 | Buffer payload; | |
148 | }; | |
149 | TAILQ_HEAD(, packet) outgoing; | |
150 | ||
aa3378df | 151 | /* |
152 | * Sets the descriptors used for communication. Disables encryption until | |
153 | * packet_set_encryption_key is called. | |
154 | */ | |
8efc0c15 | 155 | void |
156 | packet_set_connection(int fd_in, int fd_out) | |
157 | { | |
94ec8c6b | 158 | Cipher *none = cipher_by_name("none"); |
e1feb9bf | 159 | |
94ec8c6b | 160 | if (none == NULL) |
161 | fatal("packet_set_connection: cannot load cipher 'none'"); | |
5260325f | 162 | connection_in = fd_in; |
163 | connection_out = fd_out; | |
f6be21a0 | 164 | cipher_init(&send_context, none, (const u_char *)"", |
165 | 0, NULL, 0, CIPHER_ENCRYPT); | |
166 | cipher_init(&receive_context, none, (const u_char *)"", | |
167 | 0, NULL, 0, CIPHER_DECRYPT); | |
08dcb5d7 | 168 | newkeys[MODE_IN] = newkeys[MODE_OUT] = NULL; |
5260325f | 169 | if (!initialized) { |
170 | initialized = 1; | |
171 | buffer_init(&input); | |
172 | buffer_init(&output); | |
173 | buffer_init(&outgoing_packet); | |
174 | buffer_init(&incoming_packet); | |
ffd7b36b | 175 | TAILQ_INIT(&outgoing); |
5260325f | 176 | } |
8efc0c15 | 177 | } |
178 | ||
48e671d5 | 179 | /* Returns 1 if remote host is connected via socket, 0 if not. */ |
180 | ||
181 | int | |
d5bb9418 | 182 | packet_connection_is_on_socket(void) |
48e671d5 | 183 | { |
184 | struct sockaddr_storage from, to; | |
185 | socklen_t fromlen, tolen; | |
186 | ||
187 | /* filedescriptors in and out are the same, so it's a socket */ | |
188 | if (connection_in == connection_out) | |
189 | return 1; | |
190 | fromlen = sizeof(from); | |
191 | memset(&from, 0, sizeof(from)); | |
9bc5ddfe | 192 | if (getpeername(connection_in, (struct sockaddr *)&from, &fromlen) < 0) |
48e671d5 | 193 | return 0; |
194 | tolen = sizeof(to); | |
195 | memset(&to, 0, sizeof(to)); | |
9bc5ddfe | 196 | if (getpeername(connection_out, (struct sockaddr *)&to, &tolen) < 0) |
48e671d5 | 197 | return 0; |
198 | if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0) | |
199 | return 0; | |
200 | if (from.ss_family != AF_INET && from.ss_family != AF_INET6) | |
201 | return 0; | |
202 | return 1; | |
203 | } | |
204 | ||
762715ce | 205 | /* |
e050d348 | 206 | * Exports an IV from the CipherContext required to export the key |
207 | * state back from the unprivileged child to the privileged parent | |
208 | * process. | |
209 | */ | |
210 | ||
211 | void | |
212 | packet_get_keyiv(int mode, u_char *iv, u_int len) | |
213 | { | |
214 | CipherContext *cc; | |
215 | ||
216 | if (mode == MODE_OUT) | |
217 | cc = &send_context; | |
218 | else | |
219 | cc = &receive_context; | |
220 | ||
221 | cipher_get_keyiv(cc, iv, len); | |
222 | } | |
223 | ||
224 | int | |
225 | packet_get_keycontext(int mode, u_char *dat) | |
226 | { | |
227 | CipherContext *cc; | |
762715ce | 228 | |
e050d348 | 229 | if (mode == MODE_OUT) |
230 | cc = &send_context; | |
231 | else | |
232 | cc = &receive_context; | |
233 | ||
234 | return (cipher_get_keycontext(cc, dat)); | |
235 | } | |
236 | ||
237 | void | |
238 | packet_set_keycontext(int mode, u_char *dat) | |
239 | { | |
240 | CipherContext *cc; | |
762715ce | 241 | |
e050d348 | 242 | if (mode == MODE_OUT) |
243 | cc = &send_context; | |
244 | else | |
245 | cc = &receive_context; | |
246 | ||
247 | cipher_set_keycontext(cc, dat); | |
248 | } | |
249 | ||
250 | int | |
251 | packet_get_keyiv_len(int mode) | |
252 | { | |
253 | CipherContext *cc; | |
254 | ||
255 | if (mode == MODE_OUT) | |
256 | cc = &send_context; | |
257 | else | |
258 | cc = &receive_context; | |
259 | ||
260 | return (cipher_get_keyiv_len(cc)); | |
261 | } | |
262 | void | |
263 | packet_set_iv(int mode, u_char *dat) | |
264 | { | |
265 | CipherContext *cc; | |
266 | ||
267 | if (mode == MODE_OUT) | |
268 | cc = &send_context; | |
269 | else | |
270 | cc = &receive_context; | |
271 | ||
272 | cipher_set_keyiv(cc, dat); | |
273 | } | |
274 | int | |
0daa6547 | 275 | packet_get_ssh1_cipher(void) |
e050d348 | 276 | { |
277 | return (cipher_get_number(receive_context.cipher)); | |
278 | } | |
279 | ||
ffd7b36b | 280 | void |
281 | packet_get_state(int mode, u_int32_t *seqnr, u_int64_t *blocks, u_int32_t *packets) | |
e050d348 | 282 | { |
ffd7b36b | 283 | struct packet_state *state; |
284 | ||
285 | state = (mode == MODE_IN) ? &p_read : &p_send; | |
286 | *seqnr = state->seqnr; | |
287 | *blocks = state->blocks; | |
288 | *packets = state->packets; | |
e050d348 | 289 | } |
290 | ||
291 | void | |
ffd7b36b | 292 | packet_set_state(int mode, u_int32_t seqnr, u_int64_t blocks, u_int32_t packets) |
e050d348 | 293 | { |
ffd7b36b | 294 | struct packet_state *state; |
295 | ||
296 | state = (mode == MODE_IN) ? &p_read : &p_send; | |
297 | state->seqnr = seqnr; | |
298 | state->blocks = blocks; | |
299 | state->packets = packets; | |
e050d348 | 300 | } |
301 | ||
48e671d5 | 302 | /* returns 1 if connection is via ipv4 */ |
303 | ||
304 | int | |
d5bb9418 | 305 | packet_connection_is_ipv4(void) |
48e671d5 | 306 | { |
307 | struct sockaddr_storage to; | |
d45317d8 | 308 | socklen_t tolen = sizeof(to); |
48e671d5 | 309 | |
310 | memset(&to, 0, sizeof(to)); | |
311 | if (getsockname(connection_out, (struct sockaddr *)&to, &tolen) < 0) | |
312 | return 0; | |
782e2103 | 313 | if (to.ss_family == AF_INET) |
314 | return 1; | |
315 | #ifdef IPV4_IN_IPV6 | |
aff51935 | 316 | if (to.ss_family == AF_INET6 && |
782e2103 | 317 | IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr)) |
318 | return 1; | |
319 | #endif | |
320 | return 0; | |
48e671d5 | 321 | } |
322 | ||
8efc0c15 | 323 | /* Sets the connection into non-blocking mode. */ |
324 | ||
325 | void | |
d5bb9418 | 326 | packet_set_nonblocking(void) |
8efc0c15 | 327 | { |
5260325f | 328 | /* Set the socket into non-blocking mode. */ |
170694d7 | 329 | set_nonblock(connection_in); |
8efc0c15 | 330 | |
170694d7 | 331 | if (connection_out != connection_in) |
332 | set_nonblock(connection_out); | |
8efc0c15 | 333 | } |
334 | ||
335 | /* Returns the socket used for reading. */ | |
336 | ||
337 | int | |
d5bb9418 | 338 | packet_get_connection_in(void) |
8efc0c15 | 339 | { |
5260325f | 340 | return connection_in; |
8efc0c15 | 341 | } |
342 | ||
343 | /* Returns the descriptor used for writing. */ | |
344 | ||
345 | int | |
d5bb9418 | 346 | packet_get_connection_out(void) |
8efc0c15 | 347 | { |
5260325f | 348 | return connection_out; |
8efc0c15 | 349 | } |
350 | ||
351 | /* Closes the connection and clears and frees internal data structures. */ | |
352 | ||
353 | void | |
d5bb9418 | 354 | packet_close(void) |
8efc0c15 | 355 | { |
5260325f | 356 | if (!initialized) |
357 | return; | |
358 | initialized = 0; | |
359 | if (connection_in == connection_out) { | |
360 | shutdown(connection_out, SHUT_RDWR); | |
361 | close(connection_out); | |
362 | } else { | |
363 | close(connection_in); | |
364 | close(connection_out); | |
365 | } | |
366 | buffer_free(&input); | |
367 | buffer_free(&output); | |
368 | buffer_free(&outgoing_packet); | |
369 | buffer_free(&incoming_packet); | |
6ba22c93 | 370 | if (compression_buffer_ready) { |
5260325f | 371 | buffer_free(&compression_buffer); |
372 | buffer_compress_uninit(); | |
373 | } | |
3ee832e5 | 374 | cipher_cleanup(&send_context); |
375 | cipher_cleanup(&receive_context); | |
8efc0c15 | 376 | } |
377 | ||
378 | /* Sets remote side protocol flags. */ | |
379 | ||
380 | void | |
1e3b8b07 | 381 | packet_set_protocol_flags(u_int protocol_flags) |
8efc0c15 | 382 | { |
5260325f | 383 | remote_protocol_flags = protocol_flags; |
8efc0c15 | 384 | } |
385 | ||
386 | /* Returns the remote protocol flags set earlier by the above function. */ | |
387 | ||
1e3b8b07 | 388 | u_int |
d5bb9418 | 389 | packet_get_protocol_flags(void) |
8efc0c15 | 390 | { |
5260325f | 391 | return remote_protocol_flags; |
8efc0c15 | 392 | } |
393 | ||
aa3378df | 394 | /* |
395 | * Starts packet compression from the next packet on in both directions. | |
396 | * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip. | |
397 | */ | |
8efc0c15 | 398 | |
396c147e | 399 | static void |
400 | packet_init_compression(void) | |
6ba22c93 | 401 | { |
402 | if (compression_buffer_ready == 1) | |
403 | return; | |
404 | compression_buffer_ready = 1; | |
405 | buffer_init(&compression_buffer); | |
406 | } | |
407 | ||
8efc0c15 | 408 | void |
409 | packet_start_compression(int level) | |
410 | { | |
08dcb5d7 | 411 | if (packet_compression && !compat20) |
5260325f | 412 | fatal("Compression already enabled."); |
413 | packet_compression = 1; | |
6ba22c93 | 414 | packet_init_compression(); |
415 | buffer_compress_init_send(level); | |
416 | buffer_compress_init_recv(); | |
8efc0c15 | 417 | } |
418 | ||
aa3378df | 419 | /* |
420 | * Causes any further packets to be encrypted using the given key. The same | |
421 | * key is used for both sending and reception. However, both directions are | |
422 | * encrypted independently of each other. | |
423 | */ | |
9459414c | 424 | |
8efc0c15 | 425 | void |
1e3b8b07 | 426 | packet_set_encryption_key(const u_char *key, u_int keylen, |
94ec8c6b | 427 | int number) |
8efc0c15 | 428 | { |
94ec8c6b | 429 | Cipher *cipher = cipher_by_number(number); |
e1feb9bf | 430 | |
94ec8c6b | 431 | if (cipher == NULL) |
432 | fatal("packet_set_encryption_key: unknown cipher number %d", number); | |
7e7327a1 | 433 | if (keylen < 20) |
94ec8c6b | 434 | fatal("packet_set_encryption_key: keylen too small: %d", keylen); |
9459414c | 435 | if (keylen > SSH_SESSION_KEY_LENGTH) |
436 | fatal("packet_set_encryption_key: keylen too big: %d", keylen); | |
437 | memcpy(ssh1_key, key, keylen); | |
438 | ssh1_keylen = keylen; | |
3ee832e5 | 439 | cipher_init(&send_context, cipher, key, keylen, NULL, 0, CIPHER_ENCRYPT); |
440 | cipher_init(&receive_context, cipher, key, keylen, NULL, 0, CIPHER_DECRYPT); | |
8efc0c15 | 441 | } |
442 | ||
9459414c | 443 | u_int |
444 | packet_get_encryption_key(u_char *key) | |
445 | { | |
446 | if (key == NULL) | |
447 | return (ssh1_keylen); | |
448 | memcpy(key, ssh1_key, ssh1_keylen); | |
449 | return (ssh1_keylen); | |
450 | } | |
451 | ||
08dcb5d7 | 452 | /* Start constructing a packet to send. */ |
8efc0c15 | 453 | void |
08dcb5d7 | 454 | packet_start(u_char type) |
8efc0c15 | 455 | { |
08dcb5d7 | 456 | u_char buf[9]; |
457 | int len; | |
7e7327a1 | 458 | |
12bf85ed | 459 | DBG(debug("packet_start[%d]", type)); |
08dcb5d7 | 460 | len = compat20 ? 6 : 9; |
461 | memset(buf, 0, len - 1); | |
462 | buf[len - 1] = type; | |
463 | buffer_clear(&outgoing_packet); | |
464 | buffer_append(&outgoing_packet, buf, len); | |
7e7327a1 | 465 | } |
466 | ||
08dcb5d7 | 467 | /* Append payload. */ |
8efc0c15 | 468 | void |
469 | packet_put_char(int value) | |
470 | { | |
5260325f | 471 | char ch = value; |
e1feb9bf | 472 | |
5260325f | 473 | buffer_append(&outgoing_packet, &ch, 1); |
8efc0c15 | 474 | } |
8efc0c15 | 475 | void |
1e3b8b07 | 476 | packet_put_int(u_int value) |
8efc0c15 | 477 | { |
5260325f | 478 | buffer_put_int(&outgoing_packet, value); |
8efc0c15 | 479 | } |
8efc0c15 | 480 | void |
6c0fa2b1 | 481 | packet_put_string(const void *buf, u_int len) |
8efc0c15 | 482 | { |
5260325f | 483 | buffer_put_string(&outgoing_packet, buf, len); |
8efc0c15 | 484 | } |
7e7327a1 | 485 | void |
486 | packet_put_cstring(const char *str) | |
487 | { | |
449c5ba5 | 488 | buffer_put_cstring(&outgoing_packet, str); |
7e7327a1 | 489 | } |
7e7327a1 | 490 | void |
6c0fa2b1 | 491 | packet_put_raw(const void *buf, u_int len) |
7e7327a1 | 492 | { |
493 | buffer_append(&outgoing_packet, buf, len); | |
494 | } | |
8efc0c15 | 495 | void |
5260325f | 496 | packet_put_bignum(BIGNUM * value) |
8efc0c15 | 497 | { |
5260325f | 498 | buffer_put_bignum(&outgoing_packet, value); |
8efc0c15 | 499 | } |
7e7327a1 | 500 | void |
501 | packet_put_bignum2(BIGNUM * value) | |
502 | { | |
503 | buffer_put_bignum2(&outgoing_packet, value); | |
504 | } | |
8efc0c15 | 505 | |
aa3378df | 506 | /* |
507 | * Finalizes and sends the packet. If the encryption key has been set, | |
508 | * encrypts the packet before sending. | |
509 | */ | |
5260325f | 510 | |
396c147e | 511 | static void |
5ca51e19 | 512 | packet_send1(void) |
8efc0c15 | 513 | { |
a318bbf4 | 514 | u_char buf[8], *cp; |
5260325f | 515 | int i, padding, len; |
1e3b8b07 | 516 | u_int checksum; |
ca75d7de | 517 | u_int32_t rnd = 0; |
5260325f | 518 | |
aa3378df | 519 | /* |
520 | * If using packet compression, compress the payload of the outgoing | |
521 | * packet. | |
522 | */ | |
5260325f | 523 | if (packet_compression) { |
524 | buffer_clear(&compression_buffer); | |
525 | /* Skip padding. */ | |
526 | buffer_consume(&outgoing_packet, 8); | |
527 | /* padding */ | |
528 | buffer_append(&compression_buffer, "\0\0\0\0\0\0\0\0", 8); | |
529 | buffer_compress(&outgoing_packet, &compression_buffer); | |
530 | buffer_clear(&outgoing_packet); | |
531 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), | |
184eed6a | 532 | buffer_len(&compression_buffer)); |
5260325f | 533 | } |
534 | /* Compute packet length without padding (add checksum, remove padding). */ | |
535 | len = buffer_len(&outgoing_packet) + 4 - 8; | |
536 | ||
1d1ffb87 | 537 | /* Insert padding. Initialized to zero in packet_start1() */ |
5260325f | 538 | padding = 8 - len % 8; |
3ee832e5 | 539 | if (!send_context.plaintext) { |
5260325f | 540 | cp = buffer_ptr(&outgoing_packet); |
541 | for (i = 0; i < padding; i++) { | |
542 | if (i % 4 == 0) | |
ca75d7de | 543 | rnd = arc4random(); |
544 | cp[7 - i] = rnd & 0xff; | |
545 | rnd >>= 8; | |
5260325f | 546 | } |
547 | } | |
548 | buffer_consume(&outgoing_packet, 8 - padding); | |
549 | ||
550 | /* Add check bytes. */ | |
20905a8e | 551 | checksum = ssh_crc32(buffer_ptr(&outgoing_packet), |
2e73a022 | 552 | buffer_len(&outgoing_packet)); |
5260325f | 553 | PUT_32BIT(buf, checksum); |
554 | buffer_append(&outgoing_packet, buf, 4); | |
8efc0c15 | 555 | |
556 | #ifdef PACKET_DEBUG | |
5260325f | 557 | fprintf(stderr, "packet_send plain: "); |
558 | buffer_dump(&outgoing_packet); | |
8efc0c15 | 559 | #endif |
560 | ||
5260325f | 561 | /* Append to output. */ |
562 | PUT_32BIT(buf, len); | |
563 | buffer_append(&output, buf, 4); | |
6c0fa2b1 | 564 | cp = buffer_append_space(&output, buffer_len(&outgoing_packet)); |
3ee832e5 | 565 | cipher_crypt(&send_context, cp, buffer_ptr(&outgoing_packet), |
184eed6a | 566 | buffer_len(&outgoing_packet)); |
5260325f | 567 | |
8efc0c15 | 568 | #ifdef PACKET_DEBUG |
5260325f | 569 | fprintf(stderr, "encrypted: "); |
570 | buffer_dump(&output); | |
8efc0c15 | 571 | #endif |
572 | ||
5260325f | 573 | buffer_clear(&outgoing_packet); |
8efc0c15 | 574 | |
aa3378df | 575 | /* |
7b9b0103 | 576 | * Note that the packet is now only buffered in output. It won't be |
aa3378df | 577 | * actually sent until packet_write_wait or packet_write_poll is |
578 | * called. | |
579 | */ | |
8efc0c15 | 580 | } |
581 | ||
e050d348 | 582 | void |
d1ac6175 | 583 | set_newkeys(int mode) |
584 | { | |
585 | Enc *enc; | |
586 | Mac *mac; | |
587 | Comp *comp; | |
588 | CipherContext *cc; | |
ffd7b36b | 589 | u_int64_t *max_blocks; |
ca75d7de | 590 | int crypt_type; |
d1ac6175 | 591 | |
a77673cc | 592 | debug2("set_newkeys: mode %d", mode); |
d1ac6175 | 593 | |
3ee832e5 | 594 | if (mode == MODE_OUT) { |
595 | cc = &send_context; | |
ca75d7de | 596 | crypt_type = CIPHER_ENCRYPT; |
ffd7b36b | 597 | p_send.packets = p_send.blocks = 0; |
598 | max_blocks = &max_blocks_out; | |
3ee832e5 | 599 | } else { |
600 | cc = &receive_context; | |
ca75d7de | 601 | crypt_type = CIPHER_DECRYPT; |
ffd7b36b | 602 | p_read.packets = p_read.blocks = 0; |
603 | max_blocks = &max_blocks_in; | |
3ee832e5 | 604 | } |
d1ac6175 | 605 | if (newkeys[mode] != NULL) { |
a77673cc | 606 | debug("set_newkeys: rekeying"); |
3ee832e5 | 607 | cipher_cleanup(cc); |
a7ca6275 | 608 | enc = &newkeys[mode]->enc; |
609 | mac = &newkeys[mode]->mac; | |
610 | comp = &newkeys[mode]->comp; | |
cd332296 | 611 | memset(mac->key, 0, mac->key_len); |
a7ca6275 | 612 | xfree(enc->name); |
613 | xfree(enc->iv); | |
614 | xfree(enc->key); | |
615 | xfree(mac->name); | |
616 | xfree(mac->key); | |
617 | xfree(comp->name); | |
d8ee838b | 618 | xfree(newkeys[mode]); |
d1ac6175 | 619 | } |
620 | newkeys[mode] = kex_get_newkeys(mode); | |
621 | if (newkeys[mode] == NULL) | |
622 | fatal("newkeys: no keys for mode %d", mode); | |
623 | enc = &newkeys[mode]->enc; | |
624 | mac = &newkeys[mode]->mac; | |
625 | comp = &newkeys[mode]->comp; | |
626 | if (mac->md != NULL) | |
627 | mac->enabled = 1; | |
628 | DBG(debug("cipher_init_context: %d", mode)); | |
3ee832e5 | 629 | cipher_init(cc, enc->cipher, enc->key, enc->key_len, |
ca75d7de | 630 | enc->iv, enc->block_size, crypt_type); |
e050d348 | 631 | /* Deleting the keys does not gain extra security */ |
632 | /* memset(enc->iv, 0, enc->block_size); | |
633 | memset(enc->key, 0, enc->key_len); */ | |
07200973 | 634 | if ((comp->type == COMP_ZLIB || |
635 | (comp->type == COMP_DELAYED && after_authentication)) && | |
636 | comp->enabled == 0) { | |
6ba22c93 | 637 | packet_init_compression(); |
638 | if (mode == MODE_OUT) | |
639 | buffer_compress_init_send(6); | |
640 | else | |
641 | buffer_compress_init_recv(); | |
d1ac6175 | 642 | comp->enabled = 1; |
d1ac6175 | 643 | } |
40729edd | 644 | /* |
645 | * The 2^(blocksize*2) limit is too expensive for 3DES, | |
646 | * blowfish, etc, so enforce a 1GB limit for small blocksizes. | |
647 | */ | |
648 | if (enc->block_size >= 16) | |
649 | *max_blocks = (u_int64_t)1 << (enc->block_size*2); | |
650 | else | |
651 | *max_blocks = ((u_int64_t)1 << 30) / enc->block_size; | |
ffd7b36b | 652 | if (rekey_limit) |
653 | *max_blocks = MIN(*max_blocks, rekey_limit / enc->block_size); | |
d1ac6175 | 654 | } |
655 | ||
07200973 | 656 | /* |
657 | * Delayed compression for SSH2 is enabled after authentication: | |
658 | * This happans on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent, | |
659 | * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received. | |
660 | */ | |
661 | static void | |
662 | packet_enable_delayed_compress(void) | |
663 | { | |
664 | Comp *comp = NULL; | |
665 | int mode; | |
666 | ||
667 | /* | |
668 | * Remember that we are past the authentication step, so rekeying | |
669 | * with COMP_DELAYED will turn on compression immediately. | |
670 | */ | |
671 | after_authentication = 1; | |
672 | for (mode = 0; mode < MODE_MAX; mode++) { | |
673 | comp = &newkeys[mode]->comp; | |
674 | if (comp && !comp->enabled && comp->type == COMP_DELAYED) { | |
4145cbfa | 675 | packet_init_compression(); |
07200973 | 676 | if (mode == MODE_OUT) |
677 | buffer_compress_init_send(6); | |
678 | else | |
679 | buffer_compress_init_recv(); | |
680 | comp->enabled = 1; | |
681 | } | |
682 | } | |
683 | } | |
684 | ||
7e7327a1 | 685 | /* |
686 | * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) | |
687 | */ | |
396c147e | 688 | static void |
ffd7b36b | 689 | packet_send2_wrapped(void) |
7e7327a1 | 690 | { |
a318bbf4 | 691 | u_char type, *cp, *macbuf = NULL; |
b4b701be | 692 | u_char padlen, pad; |
1e3b8b07 | 693 | u_int packet_length = 0; |
b4b701be | 694 | u_int i, len; |
ca75d7de | 695 | u_int32_t rnd = 0; |
7e7327a1 | 696 | Enc *enc = NULL; |
697 | Mac *mac = NULL; | |
698 | Comp *comp = NULL; | |
699 | int block_size; | |
700 | ||
d1ac6175 | 701 | if (newkeys[MODE_OUT] != NULL) { |
702 | enc = &newkeys[MODE_OUT]->enc; | |
703 | mac = &newkeys[MODE_OUT]->mac; | |
704 | comp = &newkeys[MODE_OUT]->comp; | |
7e7327a1 | 705 | } |
3ee832e5 | 706 | block_size = enc ? enc->block_size : 8; |
7e7327a1 | 707 | |
a318bbf4 | 708 | cp = buffer_ptr(&outgoing_packet); |
709 | type = cp[5]; | |
7e7327a1 | 710 | |
711 | #ifdef PACKET_DEBUG | |
712 | fprintf(stderr, "plain: "); | |
713 | buffer_dump(&outgoing_packet); | |
714 | #endif | |
715 | ||
716 | if (comp && comp->enabled) { | |
717 | len = buffer_len(&outgoing_packet); | |
718 | /* skip header, compress only payload */ | |
719 | buffer_consume(&outgoing_packet, 5); | |
720 | buffer_clear(&compression_buffer); | |
721 | buffer_compress(&outgoing_packet, &compression_buffer); | |
722 | buffer_clear(&outgoing_packet); | |
723 | buffer_append(&outgoing_packet, "\0\0\0\0\0", 5); | |
724 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), | |
725 | buffer_len(&compression_buffer)); | |
726 | DBG(debug("compression: raw %d compressed %d", len, | |
727 | buffer_len(&outgoing_packet))); | |
728 | } | |
729 | ||
730 | /* sizeof (packet_len + pad_len + payload) */ | |
731 | len = buffer_len(&outgoing_packet); | |
732 | ||
733 | /* | |
734 | * calc size of padding, alloc space, get random data, | |
735 | * minimum padding is 4 bytes | |
736 | */ | |
737 | padlen = block_size - (len % block_size); | |
738 | if (padlen < 4) | |
739 | padlen += block_size; | |
b4b701be | 740 | if (extra_pad) { |
741 | /* will wrap if extra_pad+padlen > 255 */ | |
742 | extra_pad = roundup(extra_pad, block_size); | |
743 | pad = extra_pad - ((len + padlen) % extra_pad); | |
a49dfdec | 744 | debug3("packet_send2: adding %d (len %d padlen %d extra_pad %d)", |
b4b701be | 745 | pad, len, padlen, extra_pad); |
746 | padlen += pad; | |
747 | extra_pad = 0; | |
748 | } | |
6c0fa2b1 | 749 | cp = buffer_append_space(&outgoing_packet, padlen); |
3ee832e5 | 750 | if (enc && !send_context.plaintext) { |
1d1ffb87 | 751 | /* random padding */ |
7e7327a1 | 752 | for (i = 0; i < padlen; i++) { |
753 | if (i % 4 == 0) | |
ca75d7de | 754 | rnd = arc4random(); |
755 | cp[i] = rnd & 0xff; | |
756 | rnd >>= 8; | |
7e7327a1 | 757 | } |
1d1ffb87 | 758 | } else { |
759 | /* clear padding */ | |
760 | memset(cp, 0, padlen); | |
7e7327a1 | 761 | } |
762 | /* packet_length includes payload, padding and padding length field */ | |
763 | packet_length = buffer_len(&outgoing_packet) - 4; | |
a318bbf4 | 764 | cp = buffer_ptr(&outgoing_packet); |
765 | PUT_32BIT(cp, packet_length); | |
766 | cp[4] = padlen; | |
7e7327a1 | 767 | DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen)); |
768 | ||
769 | /* compute MAC over seqnr and packet(length fields, payload, padding) */ | |
770 | if (mac && mac->enabled) { | |
ffd7b36b | 771 | macbuf = mac_compute(mac, p_send.seqnr, |
20905a8e | 772 | buffer_ptr(&outgoing_packet), |
b2552997 | 773 | buffer_len(&outgoing_packet)); |
ffd7b36b | 774 | DBG(debug("done calc MAC out #%d", p_send.seqnr)); |
7e7327a1 | 775 | } |
776 | /* encrypt packet and append to output buffer. */ | |
6c0fa2b1 | 777 | cp = buffer_append_space(&output, buffer_len(&outgoing_packet)); |
3ee832e5 | 778 | cipher_crypt(&send_context, cp, buffer_ptr(&outgoing_packet), |
7e7327a1 | 779 | buffer_len(&outgoing_packet)); |
780 | /* append unencrypted MAC */ | |
781 | if (mac && mac->enabled) | |
782 | buffer_append(&output, (char *)macbuf, mac->mac_len); | |
783 | #ifdef PACKET_DEBUG | |
784 | fprintf(stderr, "encrypted: "); | |
785 | buffer_dump(&output); | |
786 | #endif | |
6ae2364d | 787 | /* increment sequence number for outgoing packets */ |
ffd7b36b | 788 | if (++p_send.seqnr == 0) |
bbe88b6d | 789 | logit("outgoing seqnr wraps around"); |
ffd7b36b | 790 | if (++p_send.packets == 0) |
791 | if (!(datafellows & SSH_BUG_NOREKEY)) | |
792 | fatal("XXX too many packets with same key"); | |
793 | p_send.blocks += (packet_length + 4) / block_size; | |
7e7327a1 | 794 | buffer_clear(&outgoing_packet); |
795 | ||
d1ac6175 | 796 | if (type == SSH2_MSG_NEWKEYS) |
797 | set_newkeys(MODE_OUT); | |
07200973 | 798 | else if (type == SSH2_MSG_USERAUTH_SUCCESS && server_side) |
799 | packet_enable_delayed_compress(); | |
7e7327a1 | 800 | } |
801 | ||
ffd7b36b | 802 | static void |
803 | packet_send2(void) | |
804 | { | |
805 | static int rekeying = 0; | |
806 | struct packet *p; | |
807 | u_char type, *cp; | |
808 | ||
809 | cp = buffer_ptr(&outgoing_packet); | |
810 | type = cp[5]; | |
811 | ||
812 | /* during rekeying we can only send key exchange messages */ | |
813 | if (rekeying) { | |
814 | if (!((type >= SSH2_MSG_TRANSPORT_MIN) && | |
815 | (type <= SSH2_MSG_TRANSPORT_MAX))) { | |
816 | debug("enqueue packet: %u", type); | |
817 | p = xmalloc(sizeof(*p)); | |
818 | p->type = type; | |
819 | memcpy(&p->payload, &outgoing_packet, sizeof(Buffer)); | |
820 | buffer_init(&outgoing_packet); | |
821 | TAILQ_INSERT_TAIL(&outgoing, p, next); | |
822 | return; | |
823 | } | |
824 | } | |
825 | ||
826 | /* rekeying starts with sending KEXINIT */ | |
827 | if (type == SSH2_MSG_KEXINIT) | |
828 | rekeying = 1; | |
829 | ||
830 | packet_send2_wrapped(); | |
831 | ||
832 | /* after a NEWKEYS message we can send the complete queue */ | |
833 | if (type == SSH2_MSG_NEWKEYS) { | |
834 | rekeying = 0; | |
835 | while ((p = TAILQ_FIRST(&outgoing))) { | |
836 | type = p->type; | |
837 | debug("dequeue packet: %u", type); | |
838 | buffer_free(&outgoing_packet); | |
839 | memcpy(&outgoing_packet, &p->payload, | |
840 | sizeof(Buffer)); | |
841 | TAILQ_REMOVE(&outgoing, p, next); | |
842 | xfree(p); | |
843 | packet_send2_wrapped(); | |
844 | } | |
845 | } | |
846 | } | |
847 | ||
7e7327a1 | 848 | void |
d5bb9418 | 849 | packet_send(void) |
7e7327a1 | 850 | { |
08dcb5d7 | 851 | if (compat20) |
7e7327a1 | 852 | packet_send2(); |
853 | else | |
854 | packet_send1(); | |
855 | DBG(debug("packet_send done")); | |
856 | } | |
857 | ||
aa3378df | 858 | /* |
859 | * Waits until a packet has been received, and returns its type. Note that | |
860 | * no other data is processed until this returns, so this function should not | |
861 | * be used during the interactive session. | |
862 | */ | |
8efc0c15 | 863 | |
864 | int | |
54a5250f | 865 | packet_read_seqnr(u_int32_t *seqnr_p) |
8efc0c15 | 866 | { |
5260325f | 867 | int type, len; |
20e04e90 | 868 | fd_set *setp; |
5260325f | 869 | char buf[8192]; |
7e7327a1 | 870 | DBG(debug("packet_read()")); |
5260325f | 871 | |
20e04e90 | 872 | setp = (fd_set *)xmalloc(howmany(connection_in+1, NFDBITS) * |
873 | sizeof(fd_mask)); | |
874 | ||
5260325f | 875 | /* Since we are blocking, ensure that all written packets have been sent. */ |
876 | packet_write_wait(); | |
877 | ||
878 | /* Stay in the loop until we have received a complete packet. */ | |
879 | for (;;) { | |
880 | /* Try to read a packet from the buffer. */ | |
54a5250f | 881 | type = packet_read_poll_seqnr(seqnr_p); |
08dcb5d7 | 882 | if (!compat20 && ( |
1d1ffb87 | 883 | type == SSH_SMSG_SUCCESS |
5260325f | 884 | || type == SSH_SMSG_FAILURE |
885 | || type == SSH_CMSG_EOF | |
1d1ffb87 | 886 | || type == SSH_CMSG_EXIT_CONFIRMATION)) |
95500969 | 887 | packet_check_eom(); |
5260325f | 888 | /* If we got a packet, return it. */ |
20e04e90 | 889 | if (type != SSH_MSG_NONE) { |
890 | xfree(setp); | |
5260325f | 891 | return type; |
20e04e90 | 892 | } |
aa3378df | 893 | /* |
894 | * Otherwise, wait for some data to arrive, add it to the | |
895 | * buffer, and try again. | |
896 | */ | |
20e04e90 | 897 | memset(setp, 0, howmany(connection_in + 1, NFDBITS) * |
898 | sizeof(fd_mask)); | |
899 | FD_SET(connection_in, setp); | |
aa3378df | 900 | |
5260325f | 901 | /* Wait for some data to arrive. */ |
20e04e90 | 902 | while (select(connection_in + 1, setp, NULL, NULL, NULL) == -1 && |
fd193ca4 | 903 | (errno == EAGAIN || errno == EINTR)) |
904 | ; | |
aa3378df | 905 | |
5260325f | 906 | /* Read data from the socket. */ |
907 | len = read(connection_in, buf, sizeof(buf)); | |
89cafde6 | 908 | if (len == 0) { |
bbe88b6d | 909 | logit("Connection closed by %.200s", get_remote_ipaddr()); |
2362db19 | 910 | cleanup_exit(255); |
89cafde6 | 911 | } |
5260325f | 912 | if (len < 0) |
913 | fatal("Read from socket failed: %.100s", strerror(errno)); | |
914 | /* Append it to the buffer. */ | |
915 | packet_process_incoming(buf, len); | |
916 | } | |
917 | /* NOTREACHED */ | |
8efc0c15 | 918 | } |
919 | ||
24ca6821 | 920 | int |
54a5250f | 921 | packet_read(void) |
24ca6821 | 922 | { |
54a5250f | 923 | return packet_read_seqnr(NULL); |
24ca6821 | 924 | } |
925 | ||
aa3378df | 926 | /* |
927 | * Waits until a packet has been received, verifies that its type matches | |
928 | * that given, and gives a fatal error and exits if there is a mismatch. | |
929 | */ | |
8efc0c15 | 930 | |
931 | void | |
54a5250f | 932 | packet_read_expect(int expected_type) |
8efc0c15 | 933 | { |
5260325f | 934 | int type; |
8efc0c15 | 935 | |
54a5250f | 936 | type = packet_read(); |
5260325f | 937 | if (type != expected_type) |
938 | packet_disconnect("Protocol error: expected packet type %d, got %d", | |
7e7327a1 | 939 | expected_type, type); |
8efc0c15 | 940 | } |
941 | ||
942 | /* Checks if a full packet is available in the data received so far via | |
5260325f | 943 | * packet_process_incoming. If so, reads the packet; otherwise returns |
944 | * SSH_MSG_NONE. This does not wait for data from the connection. | |
945 | * | |
946 | * SSH_MSG_DISCONNECT is handled specially here. Also, | |
947 | * SSH_MSG_IGNORE messages are skipped by this function and are never returned | |
948 | * to higher levels. | |
5260325f | 949 | */ |
8efc0c15 | 950 | |
396c147e | 951 | static int |
54a5250f | 952 | packet_read_poll1(void) |
8efc0c15 | 953 | { |
1e3b8b07 | 954 | u_int len, padded_len; |
a318bbf4 | 955 | u_char *cp, type; |
1e3b8b07 | 956 | u_int checksum, stored_checksum; |
5260325f | 957 | |
5260325f | 958 | /* Check if input size is less than minimum packet size. */ |
959 | if (buffer_len(&input) < 4 + 8) | |
960 | return SSH_MSG_NONE; | |
961 | /* Get length of incoming packet. */ | |
a318bbf4 | 962 | cp = buffer_ptr(&input); |
963 | len = GET_32BIT(cp); | |
5260325f | 964 | if (len < 1 + 2 + 2 || len > 256 * 1024) |
2fe3c2db | 965 | packet_disconnect("Bad packet length %u.", len); |
5260325f | 966 | padded_len = (len + 8) & ~7; |
967 | ||
968 | /* Check if the packet has been entirely received. */ | |
969 | if (buffer_len(&input) < 4 + padded_len) | |
970 | return SSH_MSG_NONE; | |
971 | ||
972 | /* The entire packet is in buffer. */ | |
973 | ||
974 | /* Consume packet length. */ | |
975 | buffer_consume(&input, 4); | |
976 | ||
08dcb5d7 | 977 | /* |
978 | * Cryptographic attack detector for ssh | |
979 | * (C)1998 CORE-SDI, Buenos Aires Argentina | |
980 | * Ariel Futoransky(futo@core-sdi.com) | |
981 | */ | |
3ee832e5 | 982 | if (!receive_context.plaintext && |
08dcb5d7 | 983 | detect_attack(buffer_ptr(&input), padded_len, NULL) == DEATTACK_DETECTED) |
984 | packet_disconnect("crc32 compensation attack: network attack detected"); | |
985 | ||
986 | /* Decrypt data to incoming_packet. */ | |
5260325f | 987 | buffer_clear(&incoming_packet); |
6c0fa2b1 | 988 | cp = buffer_append_space(&incoming_packet, padded_len); |
3ee832e5 | 989 | cipher_crypt(&receive_context, cp, buffer_ptr(&input), padded_len); |
08dcb5d7 | 990 | |
5260325f | 991 | buffer_consume(&input, padded_len); |
8efc0c15 | 992 | |
993 | #ifdef PACKET_DEBUG | |
5260325f | 994 | fprintf(stderr, "read_poll plain: "); |
995 | buffer_dump(&incoming_packet); | |
8efc0c15 | 996 | #endif |
5260325f | 997 | |
998 | /* Compute packet checksum. */ | |
20905a8e | 999 | checksum = ssh_crc32(buffer_ptr(&incoming_packet), |
7e7327a1 | 1000 | buffer_len(&incoming_packet) - 4); |
5260325f | 1001 | |
1002 | /* Skip padding. */ | |
1003 | buffer_consume(&incoming_packet, 8 - len % 8); | |
1004 | ||
1005 | /* Test check bytes. */ | |
5260325f | 1006 | if (len != buffer_len(&incoming_packet)) |
24ca6821 | 1007 | packet_disconnect("packet_read_poll1: len %d != buffer_len %d.", |
7e7327a1 | 1008 | len, buffer_len(&incoming_packet)); |
5260325f | 1009 | |
a318bbf4 | 1010 | cp = (u_char *)buffer_ptr(&incoming_packet) + len - 4; |
1011 | stored_checksum = GET_32BIT(cp); | |
5260325f | 1012 | if (checksum != stored_checksum) |
1013 | packet_disconnect("Corrupted check bytes on input."); | |
1014 | buffer_consume_end(&incoming_packet, 4); | |
1015 | ||
5260325f | 1016 | if (packet_compression) { |
1017 | buffer_clear(&compression_buffer); | |
1018 | buffer_uncompress(&incoming_packet, &compression_buffer); | |
1019 | buffer_clear(&incoming_packet); | |
1020 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), | |
7e7327a1 | 1021 | buffer_len(&compression_buffer)); |
5260325f | 1022 | } |
08dcb5d7 | 1023 | type = buffer_get_char(&incoming_packet); |
750bbb35 | 1024 | if (type < SSH_MSG_MIN || type > SSH_MSG_MAX) |
1025 | packet_disconnect("Invalid ssh1 packet type: %d", type); | |
08dcb5d7 | 1026 | return type; |
5260325f | 1027 | } |
1028 | ||
396c147e | 1029 | static int |
54a5250f | 1030 | packet_read_poll2(u_int32_t *seqnr_p) |
7e7327a1 | 1031 | { |
b2552997 | 1032 | static u_int packet_length = 0; |
1e3b8b07 | 1033 | u_int padlen, need; |
a318bbf4 | 1034 | u_char *macbuf, *cp, type; |
2ceb8101 | 1035 | u_int maclen, block_size; |
7e7327a1 | 1036 | Enc *enc = NULL; |
1037 | Mac *mac = NULL; | |
1038 | Comp *comp = NULL; | |
1039 | ||
d1ac6175 | 1040 | if (newkeys[MODE_IN] != NULL) { |
1041 | enc = &newkeys[MODE_IN]->enc; | |
1042 | mac = &newkeys[MODE_IN]->mac; | |
1043 | comp = &newkeys[MODE_IN]->comp; | |
7e7327a1 | 1044 | } |
1045 | maclen = mac && mac->enabled ? mac->mac_len : 0; | |
3ee832e5 | 1046 | block_size = enc ? enc->block_size : 8; |
7e7327a1 | 1047 | |
1048 | if (packet_length == 0) { | |
1049 | /* | |
1050 | * check if input size is less than the cipher block size, | |
1051 | * decrypt first block and extract length of incoming packet | |
1052 | */ | |
1053 | if (buffer_len(&input) < block_size) | |
1054 | return SSH_MSG_NONE; | |
1055 | buffer_clear(&incoming_packet); | |
6c0fa2b1 | 1056 | cp = buffer_append_space(&incoming_packet, block_size); |
3ee832e5 | 1057 | cipher_crypt(&receive_context, cp, buffer_ptr(&input), |
7e7327a1 | 1058 | block_size); |
a318bbf4 | 1059 | cp = buffer_ptr(&incoming_packet); |
1060 | packet_length = GET_32BIT(cp); | |
7e7327a1 | 1061 | if (packet_length < 1 + 4 || packet_length > 256 * 1024) { |
9adbb4a4 | 1062 | #ifdef PACKET_DEBUG |
7e7327a1 | 1063 | buffer_dump(&incoming_packet); |
9adbb4a4 | 1064 | #endif |
2fe3c2db | 1065 | packet_disconnect("Bad packet length %u.", packet_length); |
7e7327a1 | 1066 | } |
2fe3c2db | 1067 | DBG(debug("input: packet len %u", packet_length+4)); |
7e7327a1 | 1068 | buffer_consume(&input, block_size); |
1069 | } | |
1070 | /* we have a partial packet of block_size bytes */ | |
1071 | need = 4 + packet_length - block_size; | |
1072 | DBG(debug("partial packet %d, need %d, maclen %d", block_size, | |
1073 | need, maclen)); | |
1074 | if (need % block_size != 0) | |
1075 | fatal("padding error: need %d block %d mod %d", | |
1076 | need, block_size, need % block_size); | |
1077 | /* | |
1078 | * check if the entire packet has been received and | |
1079 | * decrypt into incoming_packet | |
1080 | */ | |
1081 | if (buffer_len(&input) < need + maclen) | |
1082 | return SSH_MSG_NONE; | |
1083 | #ifdef PACKET_DEBUG | |
1084 | fprintf(stderr, "read_poll enc/full: "); | |
1085 | buffer_dump(&input); | |
1086 | #endif | |
6c0fa2b1 | 1087 | cp = buffer_append_space(&incoming_packet, need); |
3ee832e5 | 1088 | cipher_crypt(&receive_context, cp, buffer_ptr(&input), need); |
7e7327a1 | 1089 | buffer_consume(&input, need); |
1090 | /* | |
1091 | * compute MAC over seqnr and packet, | |
1092 | * increment sequence number for incoming packet | |
1093 | */ | |
6ae2364d | 1094 | if (mac && mac->enabled) { |
ffd7b36b | 1095 | macbuf = mac_compute(mac, p_read.seqnr, |
20905a8e | 1096 | buffer_ptr(&incoming_packet), |
b2552997 | 1097 | buffer_len(&incoming_packet)); |
7e7327a1 | 1098 | if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0) |
94ec8c6b | 1099 | packet_disconnect("Corrupted MAC on input."); |
ffd7b36b | 1100 | DBG(debug("MAC #%d ok", p_read.seqnr)); |
7e7327a1 | 1101 | buffer_consume(&input, mac->mac_len); |
1102 | } | |
24ca6821 | 1103 | if (seqnr_p != NULL) |
ffd7b36b | 1104 | *seqnr_p = p_read.seqnr; |
1105 | if (++p_read.seqnr == 0) | |
bbe88b6d | 1106 | logit("incoming seqnr wraps around"); |
ffd7b36b | 1107 | if (++p_read.packets == 0) |
1108 | if (!(datafellows & SSH_BUG_NOREKEY)) | |
1109 | fatal("XXX too many packets with same key"); | |
1110 | p_read.blocks += (packet_length + 4) / block_size; | |
7e7327a1 | 1111 | |
1112 | /* get padlen */ | |
6c0fa2b1 | 1113 | cp = buffer_ptr(&incoming_packet); |
a318bbf4 | 1114 | padlen = cp[4]; |
7e7327a1 | 1115 | DBG(debug("input: padlen %d", padlen)); |
1116 | if (padlen < 4) | |
1117 | packet_disconnect("Corrupted padlen %d on input.", padlen); | |
1118 | ||
1119 | /* skip packet size + padlen, discard padding */ | |
1120 | buffer_consume(&incoming_packet, 4 + 1); | |
1121 | buffer_consume_end(&incoming_packet, padlen); | |
1122 | ||
1123 | DBG(debug("input: len before de-compress %d", buffer_len(&incoming_packet))); | |
1124 | if (comp && comp->enabled) { | |
1125 | buffer_clear(&compression_buffer); | |
1126 | buffer_uncompress(&incoming_packet, &compression_buffer); | |
1127 | buffer_clear(&incoming_packet); | |
1128 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), | |
1129 | buffer_len(&compression_buffer)); | |
e1feb9bf | 1130 | DBG(debug("input: len after de-compress %d", |
1131 | buffer_len(&incoming_packet))); | |
7e7327a1 | 1132 | } |
1133 | /* | |
1134 | * get packet type, implies consume. | |
1135 | * return length of payload (without type field) | |
1136 | */ | |
08dcb5d7 | 1137 | type = buffer_get_char(&incoming_packet); |
750bbb35 | 1138 | if (type < SSH2_MSG_MIN || type >= SSH2_MSG_LOCAL_MIN) |
1139 | packet_disconnect("Invalid ssh2 packet type: %d", type); | |
d1ac6175 | 1140 | if (type == SSH2_MSG_NEWKEYS) |
1141 | set_newkeys(MODE_IN); | |
07200973 | 1142 | else if (type == SSH2_MSG_USERAUTH_SUCCESS && !server_side) |
1143 | packet_enable_delayed_compress(); | |
7e7327a1 | 1144 | #ifdef PACKET_DEBUG |
12bf85ed | 1145 | fprintf(stderr, "read/plain[%d]:\r\n", type); |
7e7327a1 | 1146 | buffer_dump(&incoming_packet); |
1147 | #endif | |
08dcb5d7 | 1148 | /* reset for next packet */ |
1149 | packet_length = 0; | |
1150 | return type; | |
7e7327a1 | 1151 | } |
1152 | ||
1153 | int | |
54a5250f | 1154 | packet_read_poll_seqnr(u_int32_t *seqnr_p) |
7e7327a1 | 1155 | { |
0bc50167 | 1156 | u_int reason, seqnr; |
08dcb5d7 | 1157 | u_char type; |
7e7327a1 | 1158 | char *msg; |
7e7327a1 | 1159 | |
08dcb5d7 | 1160 | for (;;) { |
1161 | if (compat20) { | |
54a5250f | 1162 | type = packet_read_poll2(seqnr_p); |
08dcb5d7 | 1163 | if (type) |
7e7327a1 | 1164 | DBG(debug("received packet type %d", type)); |
6aacefa7 | 1165 | switch (type) { |
7e7327a1 | 1166 | case SSH2_MSG_IGNORE: |
1167 | break; | |
1168 | case SSH2_MSG_DEBUG: | |
1169 | packet_get_char(); | |
1170 | msg = packet_get_string(NULL); | |
1171 | debug("Remote: %.900s", msg); | |
1172 | xfree(msg); | |
1173 | msg = packet_get_string(NULL); | |
1174 | xfree(msg); | |
1175 | break; | |
1176 | case SSH2_MSG_DISCONNECT: | |
1177 | reason = packet_get_int(); | |
1178 | msg = packet_get_string(NULL); | |
bbe88b6d | 1179 | logit("Received disconnect from %s: %u: %.400s", |
0bc50167 | 1180 | get_remote_ipaddr(), reason, msg); |
7e7327a1 | 1181 | xfree(msg); |
2362db19 | 1182 | cleanup_exit(255); |
7e7327a1 | 1183 | break; |
5a5f4c37 | 1184 | case SSH2_MSG_UNIMPLEMENTED: |
1185 | seqnr = packet_get_int(); | |
0bc50167 | 1186 | debug("Received SSH2_MSG_UNIMPLEMENTED for %u", |
1187 | seqnr); | |
5a5f4c37 | 1188 | break; |
7e7327a1 | 1189 | default: |
1190 | return type; | |
2b87da3b | 1191 | } |
7e7327a1 | 1192 | } else { |
54a5250f | 1193 | type = packet_read_poll1(); |
6aacefa7 | 1194 | switch (type) { |
7e7327a1 | 1195 | case SSH_MSG_IGNORE: |
1196 | break; | |
1197 | case SSH_MSG_DEBUG: | |
1198 | msg = packet_get_string(NULL); | |
1199 | debug("Remote: %.900s", msg); | |
1200 | xfree(msg); | |
1201 | break; | |
1202 | case SSH_MSG_DISCONNECT: | |
1203 | msg = packet_get_string(NULL); | |
bbe88b6d | 1204 | logit("Received disconnect from %s: %.400s", |
0bc50167 | 1205 | get_remote_ipaddr(), msg); |
2362db19 | 1206 | cleanup_exit(255); |
7e7327a1 | 1207 | xfree(msg); |
1208 | break; | |
1209 | default: | |
08dcb5d7 | 1210 | if (type) |
7e7327a1 | 1211 | DBG(debug("received packet type %d", type)); |
1212 | return type; | |
2b87da3b | 1213 | } |
7e7327a1 | 1214 | } |
1215 | } | |
1216 | } | |
1217 | ||
24ca6821 | 1218 | int |
54a5250f | 1219 | packet_read_poll(void) |
24ca6821 | 1220 | { |
54a5250f | 1221 | return packet_read_poll_seqnr(NULL); |
24ca6821 | 1222 | } |
1223 | ||
aa3378df | 1224 | /* |
1225 | * Buffers the given amount of input characters. This is intended to be used | |
1226 | * together with packet_read_poll. | |
1227 | */ | |
8efc0c15 | 1228 | |
1229 | void | |
1e3b8b07 | 1230 | packet_process_incoming(const char *buf, u_int len) |
8efc0c15 | 1231 | { |
5260325f | 1232 | buffer_append(&input, buf, len); |
8efc0c15 | 1233 | } |
1234 | ||
1235 | /* Returns a character from the packet. */ | |
1236 | ||
1e3b8b07 | 1237 | u_int |
d5bb9418 | 1238 | packet_get_char(void) |
8efc0c15 | 1239 | { |
5260325f | 1240 | char ch; |
e1feb9bf | 1241 | |
5260325f | 1242 | buffer_get(&incoming_packet, &ch, 1); |
1e3b8b07 | 1243 | return (u_char) ch; |
8efc0c15 | 1244 | } |
1245 | ||
1246 | /* Returns an integer from the packet data. */ | |
1247 | ||
1e3b8b07 | 1248 | u_int |
d5bb9418 | 1249 | packet_get_int(void) |
8efc0c15 | 1250 | { |
5260325f | 1251 | return buffer_get_int(&incoming_packet); |
8efc0c15 | 1252 | } |
1253 | ||
aa3378df | 1254 | /* |
1255 | * Returns an arbitrary precision integer from the packet data. The integer | |
1256 | * must have been initialized before this call. | |
1257 | */ | |
8efc0c15 | 1258 | |
1259 | void | |
20b279e6 | 1260 | packet_get_bignum(BIGNUM * value) |
8efc0c15 | 1261 | { |
4ef6f649 | 1262 | buffer_get_bignum(&incoming_packet, value); |
8efc0c15 | 1263 | } |
1264 | ||
7e7327a1 | 1265 | void |
20b279e6 | 1266 | packet_get_bignum2(BIGNUM * value) |
7e7327a1 | 1267 | { |
4ef6f649 | 1268 | buffer_get_bignum2(&incoming_packet, value); |
7e7327a1 | 1269 | } |
1270 | ||
6c0fa2b1 | 1271 | void * |
2ceb8101 | 1272 | packet_get_raw(u_int *length_ptr) |
7e7327a1 | 1273 | { |
2ceb8101 | 1274 | u_int bytes = buffer_len(&incoming_packet); |
e1feb9bf | 1275 | |
7e7327a1 | 1276 | if (length_ptr != NULL) |
1277 | *length_ptr = bytes; | |
1278 | return buffer_ptr(&incoming_packet); | |
1279 | } | |
1280 | ||
6ae2364d | 1281 | int |
1282 | packet_remaining(void) | |
1283 | { | |
1284 | return buffer_len(&incoming_packet); | |
1285 | } | |
1286 | ||
aa3378df | 1287 | /* |
1288 | * Returns a string from the packet data. The string is allocated using | |
1289 | * xmalloc; it is the responsibility of the calling program to free it when | |
1290 | * no longer needed. The length_ptr argument may be NULL, or point to an | |
1291 | * integer into which the length of the string is stored. | |
1292 | */ | |
8efc0c15 | 1293 | |
6c0fa2b1 | 1294 | void * |
1e3b8b07 | 1295 | packet_get_string(u_int *length_ptr) |
8efc0c15 | 1296 | { |
5260325f | 1297 | return buffer_get_string(&incoming_packet, length_ptr); |
8efc0c15 | 1298 | } |
1299 | ||
aa3378df | 1300 | /* |
1301 | * Sends a diagnostic message from the server to the client. This message | |
1302 | * can be sent at any time (but not while constructing another message). The | |
1303 | * message is printed immediately, but only if the client is being executed | |
1304 | * in verbose mode. These messages are primarily intended to ease debugging | |
1305 | * authentication problems. The length of the formatted message must not | |
1306 | * exceed 1024 bytes. This will automatically call packet_write_wait. | |
1307 | */ | |
8efc0c15 | 1308 | |
1309 | void | |
5260325f | 1310 | packet_send_debug(const char *fmt,...) |
8efc0c15 | 1311 | { |
5260325f | 1312 | char buf[1024]; |
1313 | va_list args; | |
1314 | ||
f72fc97f | 1315 | if (compat20 && (datafellows & SSH_BUG_DEBUG)) |
1316 | return; | |
1317 | ||
5260325f | 1318 | va_start(args, fmt); |
1319 | vsnprintf(buf, sizeof(buf), fmt, args); | |
1320 | va_end(args); | |
1321 | ||
c4bc58eb | 1322 | if (compat20) { |
1323 | packet_start(SSH2_MSG_DEBUG); | |
1324 | packet_put_char(0); /* bool: always display */ | |
1325 | packet_put_cstring(buf); | |
1326 | packet_put_cstring(""); | |
1327 | } else { | |
1328 | packet_start(SSH_MSG_DEBUG); | |
1329 | packet_put_cstring(buf); | |
1330 | } | |
5260325f | 1331 | packet_send(); |
1332 | packet_write_wait(); | |
8efc0c15 | 1333 | } |
1334 | ||
aa3378df | 1335 | /* |
1336 | * Logs the error plus constructs and sends a disconnect packet, closes the | |
1337 | * connection, and exits. This function never returns. The error message | |
1338 | * should not contain a newline. The length of the formatted message must | |
1339 | * not exceed 1024 bytes. | |
1340 | */ | |
8efc0c15 | 1341 | |
1342 | void | |
5260325f | 1343 | packet_disconnect(const char *fmt,...) |
1344 | { | |
1345 | char buf[1024]; | |
1346 | va_list args; | |
1347 | static int disconnecting = 0; | |
e1feb9bf | 1348 | |
5260325f | 1349 | if (disconnecting) /* Guard against recursive invocations. */ |
1350 | fatal("packet_disconnect called recursively."); | |
1351 | disconnecting = 1; | |
1352 | ||
aa3378df | 1353 | /* |
1354 | * Format the message. Note that the caller must make sure the | |
1355 | * message is of limited size. | |
1356 | */ | |
5260325f | 1357 | va_start(args, fmt); |
1358 | vsnprintf(buf, sizeof(buf), fmt, args); | |
1359 | va_end(args); | |
1360 | ||
2ccb7bde | 1361 | /* Display the error locally */ |
bbe88b6d | 1362 | logit("Disconnecting: %.100s", buf); |
2ccb7bde | 1363 | |
5260325f | 1364 | /* Send the disconnect message to the other side, and wait for it to get sent. */ |
7e7327a1 | 1365 | if (compat20) { |
1366 | packet_start(SSH2_MSG_DISCONNECT); | |
1367 | packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR); | |
1368 | packet_put_cstring(buf); | |
1369 | packet_put_cstring(""); | |
1370 | } else { | |
1371 | packet_start(SSH_MSG_DISCONNECT); | |
449c5ba5 | 1372 | packet_put_cstring(buf); |
7e7327a1 | 1373 | } |
5260325f | 1374 | packet_send(); |
1375 | packet_write_wait(); | |
1376 | ||
1377 | /* Stop listening for connections. */ | |
d6746a0b | 1378 | channel_close_all(); |
5260325f | 1379 | |
1380 | /* Close the connection. */ | |
1381 | packet_close(); | |
2362db19 | 1382 | cleanup_exit(255); |
8efc0c15 | 1383 | } |
1384 | ||
aa3378df | 1385 | /* Checks if there is any buffered output, and tries to write some of the output. */ |
8efc0c15 | 1386 | |
1387 | void | |
d5bb9418 | 1388 | packet_write_poll(void) |
8efc0c15 | 1389 | { |
5260325f | 1390 | int len = buffer_len(&output); |
e1feb9bf | 1391 | |
5260325f | 1392 | if (len > 0) { |
1393 | len = write(connection_out, buffer_ptr(&output), len); | |
1394 | if (len <= 0) { | |
1395 | if (errno == EAGAIN) | |
1396 | return; | |
1397 | else | |
1398 | fatal("Write failed: %.100s", strerror(errno)); | |
1399 | } | |
1400 | buffer_consume(&output, len); | |
1401 | } | |
8efc0c15 | 1402 | } |
1403 | ||
aa3378df | 1404 | /* |
1405 | * Calls packet_write_poll repeatedly until all pending output data has been | |
1406 | * written. | |
1407 | */ | |
8efc0c15 | 1408 | |
1409 | void | |
d5bb9418 | 1410 | packet_write_wait(void) |
8efc0c15 | 1411 | { |
20e04e90 | 1412 | fd_set *setp; |
1413 | ||
1414 | setp = (fd_set *)xmalloc(howmany(connection_out + 1, NFDBITS) * | |
1415 | sizeof(fd_mask)); | |
5260325f | 1416 | packet_write_poll(); |
1417 | while (packet_have_data_to_write()) { | |
20e04e90 | 1418 | memset(setp, 0, howmany(connection_out + 1, NFDBITS) * |
1419 | sizeof(fd_mask)); | |
1420 | FD_SET(connection_out, setp); | |
1421 | while (select(connection_out + 1, NULL, setp, NULL, NULL) == -1 && | |
fd193ca4 | 1422 | (errno == EAGAIN || errno == EINTR)) |
1423 | ; | |
5260325f | 1424 | packet_write_poll(); |
1425 | } | |
20e04e90 | 1426 | xfree(setp); |
8efc0c15 | 1427 | } |
1428 | ||
1429 | /* Returns true if there is buffered data to write to the connection. */ | |
1430 | ||
1431 | int | |
d5bb9418 | 1432 | packet_have_data_to_write(void) |
8efc0c15 | 1433 | { |
5260325f | 1434 | return buffer_len(&output) != 0; |
8efc0c15 | 1435 | } |
1436 | ||
1437 | /* Returns true if there is not too much data to write to the connection. */ | |
1438 | ||
1439 | int | |
d5bb9418 | 1440 | packet_not_very_much_data_to_write(void) |
8efc0c15 | 1441 | { |
5260325f | 1442 | if (interactive_mode) |
1443 | return buffer_len(&output) < 16384; | |
1444 | else | |
1445 | return buffer_len(&output) < 128 * 1024; | |
8efc0c15 | 1446 | } |
1447 | ||
4d0cb2e5 | 1448 | |
9e637910 | 1449 | static void |
48f636b2 | 1450 | packet_set_tos(int interactive) |
1451 | { | |
00df6acd | 1452 | #if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) |
48f636b2 | 1453 | int tos = interactive ? IPTOS_LOWDELAY : IPTOS_THROUGHPUT; |
1454 | ||
1455 | if (!packet_connection_is_on_socket() || | |
1456 | !packet_connection_is_ipv4()) | |
1457 | return; | |
1458 | if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, &tos, | |
1459 | sizeof(tos)) < 0) | |
1460 | error("setsockopt IP_TOS %d: %.100s:", | |
1461 | tos, strerror(errno)); | |
4d0cb2e5 | 1462 | #endif |
00df6acd | 1463 | } |
48f636b2 | 1464 | |
8efc0c15 | 1465 | /* Informs that the current session is interactive. Sets IP flags for that. */ |
1466 | ||
1467 | void | |
b5c334cc | 1468 | packet_set_interactive(int interactive) |
8efc0c15 | 1469 | { |
b5c334cc | 1470 | static int called = 0; |
5260325f | 1471 | |
b5c334cc | 1472 | if (called) |
1473 | return; | |
1474 | called = 1; | |
1475 | ||
5260325f | 1476 | /* Record that we are in interactive mode. */ |
1477 | interactive_mode = interactive; | |
1478 | ||
48e671d5 | 1479 | /* Only set socket options if using a socket. */ |
1480 | if (!packet_connection_is_on_socket()) | |
aceb0423 | 1481 | return; |
71f0de56 | 1482 | set_nodelay(connection_in); |
48f636b2 | 1483 | packet_set_tos(interactive); |
8efc0c15 | 1484 | } |
1485 | ||
1486 | /* Returns true if the current connection is interactive. */ | |
1487 | ||
1488 | int | |
d5bb9418 | 1489 | packet_is_interactive(void) |
8efc0c15 | 1490 | { |
5260325f | 1491 | return interactive_mode; |
8efc0c15 | 1492 | } |
9d6b7add | 1493 | |
f6be21a0 | 1494 | int |
a27002e5 | 1495 | packet_set_maxsize(u_int s) |
9d6b7add | 1496 | { |
5260325f | 1497 | static int called = 0; |
e1feb9bf | 1498 | |
5260325f | 1499 | if (called) { |
bbe88b6d | 1500 | logit("packet_set_maxsize: called twice: old %d new %d", |
7e7327a1 | 1501 | max_packet_size, s); |
5260325f | 1502 | return -1; |
1503 | } | |
1504 | if (s < 4 * 1024 || s > 1024 * 1024) { | |
bbe88b6d | 1505 | logit("packet_set_maxsize: bad size %d", s); |
5260325f | 1506 | return -1; |
1507 | } | |
b6350327 | 1508 | called = 1; |
76735fe3 | 1509 | debug("packet_set_maxsize: setting to %d", s); |
5260325f | 1510 | max_packet_size = s; |
1511 | return s; | |
9d6b7add | 1512 | } |
a6215e53 | 1513 | |
b4b701be | 1514 | /* roundup current message to pad bytes */ |
1515 | void | |
1516 | packet_add_padding(u_char pad) | |
1517 | { | |
1518 | extra_pad = pad; | |
1519 | } | |
1520 | ||
a6215e53 | 1521 | /* |
1522 | * 9.2. Ignored Data Message | |
cd332296 | 1523 | * |
a6215e53 | 1524 | * byte SSH_MSG_IGNORE |
1525 | * string data | |
cd332296 | 1526 | * |
a6215e53 | 1527 | * All implementations MUST understand (and ignore) this message at any |
1528 | * time (after receiving the protocol version). No implementation is | |
1529 | * required to send them. This message can be used as an additional | |
1530 | * protection measure against advanced traffic analysis techniques. | |
1531 | */ | |
95ce5599 | 1532 | void |
1533 | packet_send_ignore(int nbytes) | |
1534 | { | |
ca75d7de | 1535 | u_int32_t rnd = 0; |
95ce5599 | 1536 | int i; |
1537 | ||
1538 | packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE); | |
a6215e53 | 1539 | packet_put_int(nbytes); |
184eed6a | 1540 | for (i = 0; i < nbytes; i++) { |
a6215e53 | 1541 | if (i % 4 == 0) |
ca75d7de | 1542 | rnd = arc4random(); |
1543 | packet_put_char(rnd & 0xff); | |
1544 | rnd >>= 8; | |
a6215e53 | 1545 | } |
1546 | } | |
ffd7b36b | 1547 | |
f6be21a0 | 1548 | #define MAX_PACKETS (1U<<31) |
ffd7b36b | 1549 | int |
1550 | packet_need_rekeying(void) | |
1551 | { | |
1552 | if (datafellows & SSH_BUG_NOREKEY) | |
1553 | return 0; | |
1554 | return | |
1555 | (p_send.packets > MAX_PACKETS) || | |
1556 | (p_read.packets > MAX_PACKETS) || | |
1557 | (max_blocks_out && (p_send.blocks > max_blocks_out)) || | |
1558 | (max_blocks_in && (p_read.blocks > max_blocks_in)); | |
1559 | } | |
1560 | ||
1561 | void | |
1562 | packet_set_rekey_limit(u_int32_t bytes) | |
1563 | { | |
1564 | rekey_limit = bytes; | |
1565 | } | |
07200973 | 1566 | |
1567 | void | |
1568 | packet_set_server(void) | |
1569 | { | |
1570 | server_side = 1; | |
1571 | } | |
1572 | ||
1573 | void | |
1574 | packet_set_authenticated(void) | |
1575 | { | |
1576 | after_authentication = 1; | |
1577 | } |