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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. |
bcbf86ec | 16 | * Copyright (c) 2000 Markus Friedl. All rights reserved. |
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" | |
bcbf86ec | 40 | RCSID("$OpenBSD: packet.c,v 1.35 2000/09/07 20:27:52 deraadt Exp $"); |
8efc0c15 | 41 | |
42 | #include "xmalloc.h" | |
43 | #include "buffer.h" | |
44 | #include "packet.h" | |
45 | #include "bufaux.h" | |
46 | #include "ssh.h" | |
47 | #include "crc32.h" | |
48 | #include "cipher.h" | |
49 | #include "getput.h" | |
50 | ||
51 | #include "compress.h" | |
52 | #include "deattack.h" | |
7368a6c8 | 53 | #include "channels.h" |
8efc0c15 | 54 | |
7e7327a1 | 55 | #include "compat.h" |
56 | #include "ssh2.h" | |
57 | ||
35484284 | 58 | #include <openssl/bn.h> |
59 | #include <openssl/dh.h> | |
60 | #include <openssl/hmac.h> | |
7e7327a1 | 61 | #include "buffer.h" |
62 | #include "kex.h" | |
63 | #include "hmac.h" | |
64 | ||
65 | #ifdef PACKET_DEBUG | |
66 | #define DBG(x) x | |
67 | #else | |
68 | #define DBG(x) | |
69 | #endif | |
70 | ||
aa3378df | 71 | /* |
72 | * This variable contains the file descriptors used for communicating with | |
73 | * the other side. connection_in is used for reading; connection_out for | |
74 | * writing. These can be the same descriptor, in which case it is assumed to | |
75 | * be a socket. | |
76 | */ | |
8efc0c15 | 77 | static int connection_in = -1; |
78 | static int connection_out = -1; | |
79 | ||
aa3378df | 80 | /* |
81 | * Cipher type. This value is only used to determine whether to pad the | |
82 | * packets with zeroes or random data. | |
83 | */ | |
8efc0c15 | 84 | static int cipher_type = SSH_CIPHER_NONE; |
85 | ||
86 | /* Protocol flags for the remote side. */ | |
87 | static unsigned int remote_protocol_flags = 0; | |
88 | ||
89 | /* Encryption context for receiving data. This is only used for decryption. */ | |
90 | static CipherContext receive_context; | |
5260325f | 91 | |
92 | /* Encryption context for sending data. This is only used for encryption. */ | |
8efc0c15 | 93 | static CipherContext send_context; |
94 | ||
95 | /* Buffer for raw input data from the socket. */ | |
96 | static Buffer input; | |
97 | ||
98 | /* Buffer for raw output data going to the socket. */ | |
99 | static Buffer output; | |
100 | ||
101 | /* Buffer for the partial outgoing packet being constructed. */ | |
102 | static Buffer outgoing_packet; | |
103 | ||
104 | /* Buffer for the incoming packet currently being processed. */ | |
105 | static Buffer incoming_packet; | |
106 | ||
107 | /* Scratch buffer for packet compression/decompression. */ | |
108 | static Buffer compression_buffer; | |
109 | ||
110 | /* Flag indicating whether packet compression/decompression is enabled. */ | |
111 | static int packet_compression = 0; | |
112 | ||
9d6b7add | 113 | /* default maximum packet size */ |
114 | int max_packet_size = 32768; | |
115 | ||
8efc0c15 | 116 | /* Flag indicating whether this module has been initialized. */ |
117 | static int initialized = 0; | |
118 | ||
119 | /* Set to true if the connection is interactive. */ | |
120 | static int interactive_mode = 0; | |
121 | ||
7e7327a1 | 122 | /* True if SSH2 packet format is used */ |
123 | int use_ssh2_packet_format = 0; | |
124 | ||
125 | /* Session key information for Encryption and MAC */ | |
126 | Kex *kex = NULL; | |
127 | ||
128 | void | |
129 | packet_set_kex(Kex *k) | |
130 | { | |
131 | if( k->mac[MODE_IN ].key == NULL || | |
132 | k->enc[MODE_IN ].key == NULL || | |
133 | k->enc[MODE_IN ].iv == NULL || | |
134 | k->mac[MODE_OUT].key == NULL || | |
135 | k->enc[MODE_OUT].key == NULL || | |
136 | k->enc[MODE_OUT].iv == NULL) | |
137 | fatal("bad KEX"); | |
138 | kex = k; | |
139 | } | |
140 | void | |
141 | clear_enc_keys(Enc *enc, int len) | |
142 | { | |
143 | memset(enc->iv, 0, len); | |
144 | memset(enc->key, 0, len); | |
145 | xfree(enc->iv); | |
146 | xfree(enc->key); | |
147 | enc->iv = NULL; | |
148 | enc->key = NULL; | |
149 | } | |
150 | void | |
151 | packet_set_ssh2_format(void) | |
152 | { | |
3189621b | 153 | DBG(debug("use_ssh2_packet_format")); |
7e7327a1 | 154 | use_ssh2_packet_format = 1; |
155 | } | |
156 | ||
aa3378df | 157 | /* |
158 | * Sets the descriptors used for communication. Disables encryption until | |
159 | * packet_set_encryption_key is called. | |
160 | */ | |
8efc0c15 | 161 | void |
162 | packet_set_connection(int fd_in, int fd_out) | |
163 | { | |
5260325f | 164 | connection_in = fd_in; |
165 | connection_out = fd_out; | |
166 | cipher_type = SSH_CIPHER_NONE; | |
8ce64345 | 167 | cipher_set_key(&send_context, SSH_CIPHER_NONE, (unsigned char *) "", 0); |
168 | cipher_set_key(&receive_context, SSH_CIPHER_NONE, (unsigned char *) "", 0); | |
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); | |
175 | } | |
176 | /* Kludge: arrange the close function to be called from fatal(). */ | |
177 | fatal_add_cleanup((void (*) (void *)) packet_close, NULL); | |
8efc0c15 | 178 | } |
179 | ||
48e671d5 | 180 | /* Returns 1 if remote host is connected via socket, 0 if not. */ |
181 | ||
182 | int | |
183 | packet_connection_is_on_socket() | |
184 | { | |
185 | struct sockaddr_storage from, to; | |
186 | socklen_t fromlen, tolen; | |
187 | ||
188 | /* filedescriptors in and out are the same, so it's a socket */ | |
189 | if (connection_in == connection_out) | |
190 | return 1; | |
191 | fromlen = sizeof(from); | |
192 | memset(&from, 0, sizeof(from)); | |
9bc5ddfe | 193 | if (getpeername(connection_in, (struct sockaddr *)&from, &fromlen) < 0) |
48e671d5 | 194 | return 0; |
195 | tolen = sizeof(to); | |
196 | memset(&to, 0, sizeof(to)); | |
9bc5ddfe | 197 | if (getpeername(connection_out, (struct sockaddr *)&to, &tolen) < 0) |
48e671d5 | 198 | return 0; |
199 | if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0) | |
200 | return 0; | |
201 | if (from.ss_family != AF_INET && from.ss_family != AF_INET6) | |
202 | return 0; | |
203 | return 1; | |
204 | } | |
205 | ||
206 | /* returns 1 if connection is via ipv4 */ | |
207 | ||
208 | int | |
209 | packet_connection_is_ipv4() | |
210 | { | |
211 | struct sockaddr_storage to; | |
d45317d8 | 212 | socklen_t tolen = sizeof(to); |
48e671d5 | 213 | |
214 | memset(&to, 0, sizeof(to)); | |
215 | if (getsockname(connection_out, (struct sockaddr *)&to, &tolen) < 0) | |
216 | return 0; | |
217 | if (to.ss_family != AF_INET) | |
218 | return 0; | |
219 | return 1; | |
220 | } | |
221 | ||
8efc0c15 | 222 | /* Sets the connection into non-blocking mode. */ |
223 | ||
224 | void | |
225 | packet_set_nonblocking() | |
226 | { | |
5260325f | 227 | /* Set the socket into non-blocking mode. */ |
228 | if (fcntl(connection_in, F_SETFL, O_NONBLOCK) < 0) | |
229 | error("fcntl O_NONBLOCK: %.100s", strerror(errno)); | |
8efc0c15 | 230 | |
5260325f | 231 | if (connection_out != connection_in) { |
232 | if (fcntl(connection_out, F_SETFL, O_NONBLOCK) < 0) | |
233 | error("fcntl O_NONBLOCK: %.100s", strerror(errno)); | |
234 | } | |
8efc0c15 | 235 | } |
236 | ||
237 | /* Returns the socket used for reading. */ | |
238 | ||
239 | int | |
240 | packet_get_connection_in() | |
241 | { | |
5260325f | 242 | return connection_in; |
8efc0c15 | 243 | } |
244 | ||
245 | /* Returns the descriptor used for writing. */ | |
246 | ||
247 | int | |
248 | packet_get_connection_out() | |
249 | { | |
5260325f | 250 | return connection_out; |
8efc0c15 | 251 | } |
252 | ||
253 | /* Closes the connection and clears and frees internal data structures. */ | |
254 | ||
255 | void | |
256 | packet_close() | |
257 | { | |
5260325f | 258 | if (!initialized) |
259 | return; | |
260 | initialized = 0; | |
261 | if (connection_in == connection_out) { | |
262 | shutdown(connection_out, SHUT_RDWR); | |
263 | close(connection_out); | |
264 | } else { | |
265 | close(connection_in); | |
266 | close(connection_out); | |
267 | } | |
268 | buffer_free(&input); | |
269 | buffer_free(&output); | |
270 | buffer_free(&outgoing_packet); | |
271 | buffer_free(&incoming_packet); | |
272 | if (packet_compression) { | |
273 | buffer_free(&compression_buffer); | |
274 | buffer_compress_uninit(); | |
275 | } | |
8efc0c15 | 276 | } |
277 | ||
278 | /* Sets remote side protocol flags. */ | |
279 | ||
280 | void | |
281 | packet_set_protocol_flags(unsigned int protocol_flags) | |
282 | { | |
5260325f | 283 | remote_protocol_flags = protocol_flags; |
284 | channel_set_options((protocol_flags & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) != 0); | |
8efc0c15 | 285 | } |
286 | ||
287 | /* Returns the remote protocol flags set earlier by the above function. */ | |
288 | ||
289 | unsigned int | |
290 | packet_get_protocol_flags() | |
291 | { | |
5260325f | 292 | return remote_protocol_flags; |
8efc0c15 | 293 | } |
294 | ||
aa3378df | 295 | /* |
296 | * Starts packet compression from the next packet on in both directions. | |
297 | * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip. | |
298 | */ | |
8efc0c15 | 299 | |
7e7327a1 | 300 | /*** XXXXX todo: kex means re-init */ |
8efc0c15 | 301 | void |
302 | packet_start_compression(int level) | |
303 | { | |
5260325f | 304 | if (packet_compression) |
305 | fatal("Compression already enabled."); | |
306 | packet_compression = 1; | |
307 | buffer_init(&compression_buffer); | |
308 | buffer_compress_init(level); | |
8efc0c15 | 309 | } |
310 | ||
aa3378df | 311 | /* |
312 | * Encrypts the given number of bytes, copying from src to dest. bytes is | |
313 | * known to be a multiple of 8. | |
314 | */ | |
8efc0c15 | 315 | |
316 | void | |
5260325f | 317 | packet_encrypt(CipherContext * cc, void *dest, void *src, |
7e7327a1 | 318 | unsigned int bytes) |
8efc0c15 | 319 | { |
5260325f | 320 | cipher_encrypt(cc, dest, src, bytes); |
8efc0c15 | 321 | } |
322 | ||
aa3378df | 323 | /* |
324 | * Decrypts the given number of bytes, copying from src to dest. bytes is | |
325 | * known to be a multiple of 8. | |
326 | */ | |
8efc0c15 | 327 | |
328 | void | |
5260325f | 329 | packet_decrypt(CipherContext * cc, void *dest, void *src, |
7e7327a1 | 330 | unsigned int bytes) |
8efc0c15 | 331 | { |
5260325f | 332 | int i; |
333 | ||
334 | if ((bytes % 8) != 0) | |
335 | fatal("packet_decrypt: bad ciphertext length %d", bytes); | |
336 | ||
aa3378df | 337 | /* |
338 | * Cryptographic attack detector for ssh - Modifications for packet.c | |
339 | * (C)1998 CORE-SDI, Buenos Aires Argentina Ariel Futoransky(futo@core-sdi.com) | |
340 | */ | |
5260325f | 341 | |
7e7327a1 | 342 | if (cc->type == SSH_CIPHER_NONE || compat20) { |
5260325f | 343 | i = DEATTACK_OK; |
7e7327a1 | 344 | } else { |
5260325f | 345 | i = detect_attack(src, bytes, NULL); |
5260325f | 346 | } |
5260325f | 347 | if (i == DEATTACK_DETECTED) |
348 | packet_disconnect("crc32 compensation attack: network attack detected"); | |
349 | ||
350 | cipher_decrypt(cc, dest, src, bytes); | |
8efc0c15 | 351 | } |
352 | ||
aa3378df | 353 | /* |
354 | * Causes any further packets to be encrypted using the given key. The same | |
355 | * key is used for both sending and reception. However, both directions are | |
356 | * encrypted independently of each other. | |
357 | */ | |
8efc0c15 | 358 | |
359 | void | |
360 | packet_set_encryption_key(const unsigned char *key, unsigned int keylen, | |
7e7327a1 | 361 | int cipher) |
8efc0c15 | 362 | { |
7e7327a1 | 363 | if (keylen < 20) |
364 | fatal("keylen too small: %d", keylen); | |
365 | ||
5260325f | 366 | /* All other ciphers use the same key in both directions for now. */ |
8ce64345 | 367 | cipher_set_key(&receive_context, cipher, key, keylen); |
368 | cipher_set_key(&send_context, cipher, key, keylen); | |
8efc0c15 | 369 | } |
370 | ||
371 | /* Starts constructing a packet to send. */ | |
372 | ||
373 | void | |
7e7327a1 | 374 | packet_start1(int type) |
8efc0c15 | 375 | { |
5260325f | 376 | char buf[9]; |
8efc0c15 | 377 | |
5260325f | 378 | buffer_clear(&outgoing_packet); |
379 | memset(buf, 0, 8); | |
380 | buf[8] = type; | |
381 | buffer_append(&outgoing_packet, buf, 9); | |
8efc0c15 | 382 | } |
383 | ||
7e7327a1 | 384 | void |
385 | packet_start2(int type) | |
386 | { | |
387 | char buf[4+1+1]; | |
388 | ||
389 | buffer_clear(&outgoing_packet); | |
390 | memset(buf, 0, sizeof buf); | |
391 | /* buf[0..3] = payload_len; */ | |
392 | /* buf[4] = pad_len; */ | |
393 | buf[5] = type & 0xff; | |
394 | buffer_append(&outgoing_packet, buf, sizeof buf); | |
395 | } | |
396 | ||
397 | void | |
398 | packet_start(int type) | |
399 | { | |
400 | DBG(debug("packet_start[%d]",type)); | |
401 | if (use_ssh2_packet_format) | |
402 | packet_start2(type); | |
403 | else | |
404 | packet_start1(type); | |
405 | } | |
406 | ||
8efc0c15 | 407 | /* Appends a character to the packet data. */ |
408 | ||
409 | void | |
410 | packet_put_char(int value) | |
411 | { | |
5260325f | 412 | char ch = value; |
413 | buffer_append(&outgoing_packet, &ch, 1); | |
8efc0c15 | 414 | } |
415 | ||
416 | /* Appends an integer to the packet data. */ | |
417 | ||
418 | void | |
419 | packet_put_int(unsigned int value) | |
420 | { | |
5260325f | 421 | buffer_put_int(&outgoing_packet, value); |
8efc0c15 | 422 | } |
423 | ||
424 | /* Appends a string to packet data. */ | |
425 | ||
426 | void | |
427 | packet_put_string(const char *buf, unsigned int len) | |
428 | { | |
5260325f | 429 | buffer_put_string(&outgoing_packet, buf, len); |
8efc0c15 | 430 | } |
7e7327a1 | 431 | void |
432 | packet_put_cstring(const char *str) | |
433 | { | |
434 | buffer_put_string(&outgoing_packet, str, strlen(str)); | |
435 | } | |
436 | ||
437 | void | |
438 | packet_put_raw(const char *buf, unsigned int len) | |
439 | { | |
440 | buffer_append(&outgoing_packet, buf, len); | |
441 | } | |
442 | ||
8efc0c15 | 443 | |
444 | /* Appends an arbitrary precision integer to packet data. */ | |
445 | ||
446 | void | |
5260325f | 447 | packet_put_bignum(BIGNUM * value) |
8efc0c15 | 448 | { |
5260325f | 449 | buffer_put_bignum(&outgoing_packet, value); |
8efc0c15 | 450 | } |
7e7327a1 | 451 | void |
452 | packet_put_bignum2(BIGNUM * value) | |
453 | { | |
454 | buffer_put_bignum2(&outgoing_packet, value); | |
455 | } | |
8efc0c15 | 456 | |
aa3378df | 457 | /* |
458 | * Finalizes and sends the packet. If the encryption key has been set, | |
459 | * encrypts the packet before sending. | |
460 | */ | |
5260325f | 461 | |
8efc0c15 | 462 | void |
7e7327a1 | 463 | packet_send1() |
8efc0c15 | 464 | { |
5260325f | 465 | char buf[8], *cp; |
466 | int i, padding, len; | |
467 | unsigned int checksum; | |
468 | u_int32_t rand = 0; | |
469 | ||
aa3378df | 470 | /* |
471 | * If using packet compression, compress the payload of the outgoing | |
472 | * packet. | |
473 | */ | |
5260325f | 474 | if (packet_compression) { |
475 | buffer_clear(&compression_buffer); | |
476 | /* Skip padding. */ | |
477 | buffer_consume(&outgoing_packet, 8); | |
478 | /* padding */ | |
479 | buffer_append(&compression_buffer, "\0\0\0\0\0\0\0\0", 8); | |
480 | buffer_compress(&outgoing_packet, &compression_buffer); | |
481 | buffer_clear(&outgoing_packet); | |
482 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), | |
483 | buffer_len(&compression_buffer)); | |
484 | } | |
485 | /* Compute packet length without padding (add checksum, remove padding). */ | |
486 | len = buffer_len(&outgoing_packet) + 4 - 8; | |
487 | ||
1d1ffb87 | 488 | /* Insert padding. Initialized to zero in packet_start1() */ |
5260325f | 489 | padding = 8 - len % 8; |
490 | if (cipher_type != SSH_CIPHER_NONE) { | |
491 | cp = buffer_ptr(&outgoing_packet); | |
492 | for (i = 0; i < padding; i++) { | |
493 | if (i % 4 == 0) | |
494 | rand = arc4random(); | |
495 | cp[7 - i] = rand & 0xff; | |
496 | rand >>= 8; | |
497 | } | |
498 | } | |
499 | buffer_consume(&outgoing_packet, 8 - padding); | |
500 | ||
501 | /* Add check bytes. */ | |
2e73a022 | 502 | checksum = ssh_crc32((unsigned char *) buffer_ptr(&outgoing_packet), |
503 | buffer_len(&outgoing_packet)); | |
5260325f | 504 | PUT_32BIT(buf, checksum); |
505 | buffer_append(&outgoing_packet, buf, 4); | |
8efc0c15 | 506 | |
507 | #ifdef PACKET_DEBUG | |
5260325f | 508 | fprintf(stderr, "packet_send plain: "); |
509 | buffer_dump(&outgoing_packet); | |
8efc0c15 | 510 | #endif |
511 | ||
5260325f | 512 | /* Append to output. */ |
513 | PUT_32BIT(buf, len); | |
514 | buffer_append(&output, buf, 4); | |
515 | buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); | |
516 | packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), | |
517 | buffer_len(&outgoing_packet)); | |
518 | ||
8efc0c15 | 519 | #ifdef PACKET_DEBUG |
5260325f | 520 | fprintf(stderr, "encrypted: "); |
521 | buffer_dump(&output); | |
8efc0c15 | 522 | #endif |
523 | ||
5260325f | 524 | buffer_clear(&outgoing_packet); |
8efc0c15 | 525 | |
aa3378df | 526 | /* |
527 | * Note that the packet is now only buffered in output. It won\'t be | |
528 | * actually sent until packet_write_wait or packet_write_poll is | |
529 | * called. | |
530 | */ | |
8efc0c15 | 531 | } |
532 | ||
7e7327a1 | 533 | /* |
534 | * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) | |
535 | */ | |
536 | void | |
537 | packet_send2() | |
538 | { | |
539 | unsigned char *macbuf = NULL; | |
540 | char *cp; | |
541 | unsigned int packet_length = 0; | |
542 | unsigned int i, padlen, len; | |
543 | u_int32_t rand = 0; | |
6ae2364d | 544 | static unsigned int seqnr = 0; |
7e7327a1 | 545 | int type; |
546 | Enc *enc = NULL; | |
547 | Mac *mac = NULL; | |
548 | Comp *comp = NULL; | |
549 | int block_size; | |
550 | ||
551 | if (kex != NULL) { | |
552 | enc = &kex->enc[MODE_OUT]; | |
553 | mac = &kex->mac[MODE_OUT]; | |
554 | comp = &kex->comp[MODE_OUT]; | |
555 | } | |
556 | block_size = enc ? enc->block_size : 8; | |
557 | ||
558 | cp = buffer_ptr(&outgoing_packet); | |
559 | type = cp[5] & 0xff; | |
560 | ||
561 | #ifdef PACKET_DEBUG | |
562 | fprintf(stderr, "plain: "); | |
563 | buffer_dump(&outgoing_packet); | |
564 | #endif | |
565 | ||
566 | if (comp && comp->enabled) { | |
567 | len = buffer_len(&outgoing_packet); | |
568 | /* skip header, compress only payload */ | |
569 | buffer_consume(&outgoing_packet, 5); | |
570 | buffer_clear(&compression_buffer); | |
571 | buffer_compress(&outgoing_packet, &compression_buffer); | |
572 | buffer_clear(&outgoing_packet); | |
573 | buffer_append(&outgoing_packet, "\0\0\0\0\0", 5); | |
574 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), | |
575 | buffer_len(&compression_buffer)); | |
576 | DBG(debug("compression: raw %d compressed %d", len, | |
577 | buffer_len(&outgoing_packet))); | |
578 | } | |
579 | ||
580 | /* sizeof (packet_len + pad_len + payload) */ | |
581 | len = buffer_len(&outgoing_packet); | |
582 | ||
583 | /* | |
584 | * calc size of padding, alloc space, get random data, | |
585 | * minimum padding is 4 bytes | |
586 | */ | |
587 | padlen = block_size - (len % block_size); | |
588 | if (padlen < 4) | |
589 | padlen += block_size; | |
590 | buffer_append_space(&outgoing_packet, &cp, padlen); | |
591 | if (enc && enc->type != SSH_CIPHER_NONE) { | |
1d1ffb87 | 592 | /* random padding */ |
7e7327a1 | 593 | for (i = 0; i < padlen; i++) { |
594 | if (i % 4 == 0) | |
595 | rand = arc4random(); | |
596 | cp[i] = rand & 0xff; | |
597 | rand <<= 8; | |
598 | } | |
1d1ffb87 | 599 | } else { |
600 | /* clear padding */ | |
601 | memset(cp, 0, padlen); | |
7e7327a1 | 602 | } |
603 | /* packet_length includes payload, padding and padding length field */ | |
604 | packet_length = buffer_len(&outgoing_packet) - 4; | |
605 | cp = buffer_ptr(&outgoing_packet); | |
606 | PUT_32BIT(cp, packet_length); | |
607 | cp[4] = padlen & 0xff; | |
608 | DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen)); | |
609 | ||
610 | /* compute MAC over seqnr and packet(length fields, payload, padding) */ | |
611 | if (mac && mac->enabled) { | |
612 | macbuf = hmac( mac->md, seqnr, | |
613 | (unsigned char *) buffer_ptr(&outgoing_packet), | |
614 | buffer_len(&outgoing_packet), | |
615 | mac->key, mac->key_len | |
616 | ); | |
617 | DBG(debug("done calc HMAC out #%d", seqnr)); | |
618 | } | |
619 | /* encrypt packet and append to output buffer. */ | |
620 | buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); | |
621 | packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), | |
622 | buffer_len(&outgoing_packet)); | |
623 | /* append unencrypted MAC */ | |
624 | if (mac && mac->enabled) | |
625 | buffer_append(&output, (char *)macbuf, mac->mac_len); | |
626 | #ifdef PACKET_DEBUG | |
627 | fprintf(stderr, "encrypted: "); | |
628 | buffer_dump(&output); | |
629 | #endif | |
6ae2364d | 630 | /* increment sequence number for outgoing packets */ |
631 | if (++seqnr == 0) | |
632 | log("outgoing seqnr wraps around"); | |
7e7327a1 | 633 | buffer_clear(&outgoing_packet); |
634 | ||
635 | if (type == SSH2_MSG_NEWKEYS) { | |
636 | if (kex==NULL || mac==NULL || enc==NULL || comp==NULL) | |
637 | fatal("packet_send2: no KEX"); | |
638 | if (mac->md != NULL) | |
639 | mac->enabled = 1; | |
3189621b | 640 | DBG(debug("cipher_set_key_iv send_context")); |
7e7327a1 | 641 | cipher_set_key_iv(&send_context, enc->type, |
642 | enc->key, enc->key_len, | |
643 | enc->iv, enc->iv_len); | |
644 | clear_enc_keys(enc, kex->we_need); | |
645 | if (comp->type != 0 && comp->enabled == 0) { | |
646 | comp->enabled = 1; | |
647 | if (! packet_compression) | |
648 | packet_start_compression(6); | |
649 | } | |
650 | } | |
651 | } | |
652 | ||
653 | void | |
654 | packet_send() | |
655 | { | |
656 | if (use_ssh2_packet_format) | |
657 | packet_send2(); | |
658 | else | |
659 | packet_send1(); | |
660 | DBG(debug("packet_send done")); | |
661 | } | |
662 | ||
aa3378df | 663 | /* |
664 | * Waits until a packet has been received, and returns its type. Note that | |
665 | * no other data is processed until this returns, so this function should not | |
666 | * be used during the interactive session. | |
667 | */ | |
8efc0c15 | 668 | |
669 | int | |
670 | packet_read(int *payload_len_ptr) | |
671 | { | |
5260325f | 672 | int type, len; |
673 | fd_set set; | |
674 | char buf[8192]; | |
7e7327a1 | 675 | DBG(debug("packet_read()")); |
5260325f | 676 | |
677 | /* Since we are blocking, ensure that all written packets have been sent. */ | |
678 | packet_write_wait(); | |
679 | ||
680 | /* Stay in the loop until we have received a complete packet. */ | |
681 | for (;;) { | |
682 | /* Try to read a packet from the buffer. */ | |
683 | type = packet_read_poll(payload_len_ptr); | |
1d1ffb87 | 684 | if (!use_ssh2_packet_format && ( |
685 | type == SSH_SMSG_SUCCESS | |
5260325f | 686 | || type == SSH_SMSG_FAILURE |
687 | || type == SSH_CMSG_EOF | |
1d1ffb87 | 688 | || type == SSH_CMSG_EXIT_CONFIRMATION)) |
5260325f | 689 | packet_integrity_check(*payload_len_ptr, 0, type); |
690 | /* If we got a packet, return it. */ | |
691 | if (type != SSH_MSG_NONE) | |
692 | return type; | |
aa3378df | 693 | /* |
694 | * Otherwise, wait for some data to arrive, add it to the | |
695 | * buffer, and try again. | |
696 | */ | |
5260325f | 697 | FD_ZERO(&set); |
698 | FD_SET(connection_in, &set); | |
aa3378df | 699 | |
5260325f | 700 | /* Wait for some data to arrive. */ |
701 | select(connection_in + 1, &set, NULL, NULL, NULL); | |
aa3378df | 702 | |
5260325f | 703 | /* Read data from the socket. */ |
704 | len = read(connection_in, buf, sizeof(buf)); | |
89cafde6 | 705 | if (len == 0) { |
706 | log("Connection closed by %.200s", get_remote_ipaddr()); | |
707 | fatal_cleanup(); | |
708 | } | |
5260325f | 709 | if (len < 0) |
710 | fatal("Read from socket failed: %.100s", strerror(errno)); | |
711 | /* Append it to the buffer. */ | |
712 | packet_process_incoming(buf, len); | |
713 | } | |
714 | /* NOTREACHED */ | |
8efc0c15 | 715 | } |
716 | ||
aa3378df | 717 | /* |
718 | * Waits until a packet has been received, verifies that its type matches | |
719 | * that given, and gives a fatal error and exits if there is a mismatch. | |
720 | */ | |
8efc0c15 | 721 | |
722 | void | |
723 | packet_read_expect(int *payload_len_ptr, int expected_type) | |
724 | { | |
5260325f | 725 | int type; |
8efc0c15 | 726 | |
5260325f | 727 | type = packet_read(payload_len_ptr); |
728 | if (type != expected_type) | |
729 | packet_disconnect("Protocol error: expected packet type %d, got %d", | |
7e7327a1 | 730 | expected_type, type); |
8efc0c15 | 731 | } |
732 | ||
733 | /* Checks if a full packet is available in the data received so far via | |
5260325f | 734 | * packet_process_incoming. If so, reads the packet; otherwise returns |
735 | * SSH_MSG_NONE. This does not wait for data from the connection. | |
736 | * | |
737 | * SSH_MSG_DISCONNECT is handled specially here. Also, | |
738 | * SSH_MSG_IGNORE messages are skipped by this function and are never returned | |
739 | * to higher levels. | |
740 | * | |
741 | * The returned payload_len does include space consumed by: | |
742 | * Packet length | |
743 | * Padding | |
744 | * Packet type | |
745 | * Check bytes | |
746 | */ | |
8efc0c15 | 747 | |
748 | int | |
7e7327a1 | 749 | packet_read_poll1(int *payload_len_ptr) |
8efc0c15 | 750 | { |
5260325f | 751 | unsigned int len, padded_len; |
752 | unsigned char *ucp; | |
7e7327a1 | 753 | char buf[8], *cp; |
5260325f | 754 | unsigned int checksum, stored_checksum; |
755 | ||
5260325f | 756 | /* Check if input size is less than minimum packet size. */ |
757 | if (buffer_len(&input) < 4 + 8) | |
758 | return SSH_MSG_NONE; | |
759 | /* Get length of incoming packet. */ | |
760 | ucp = (unsigned char *) buffer_ptr(&input); | |
761 | len = GET_32BIT(ucp); | |
762 | if (len < 1 + 2 + 2 || len > 256 * 1024) | |
763 | packet_disconnect("Bad packet length %d.", len); | |
764 | padded_len = (len + 8) & ~7; | |
765 | ||
766 | /* Check if the packet has been entirely received. */ | |
767 | if (buffer_len(&input) < 4 + padded_len) | |
768 | return SSH_MSG_NONE; | |
769 | ||
770 | /* The entire packet is in buffer. */ | |
771 | ||
772 | /* Consume packet length. */ | |
773 | buffer_consume(&input, 4); | |
774 | ||
775 | /* Copy data to incoming_packet. */ | |
776 | buffer_clear(&incoming_packet); | |
777 | buffer_append_space(&incoming_packet, &cp, padded_len); | |
778 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len); | |
779 | buffer_consume(&input, padded_len); | |
8efc0c15 | 780 | |
781 | #ifdef PACKET_DEBUG | |
5260325f | 782 | fprintf(stderr, "read_poll plain: "); |
783 | buffer_dump(&incoming_packet); | |
8efc0c15 | 784 | #endif |
5260325f | 785 | |
786 | /* Compute packet checksum. */ | |
2e73a022 | 787 | checksum = ssh_crc32((unsigned char *) buffer_ptr(&incoming_packet), |
7e7327a1 | 788 | buffer_len(&incoming_packet) - 4); |
5260325f | 789 | |
790 | /* Skip padding. */ | |
791 | buffer_consume(&incoming_packet, 8 - len % 8); | |
792 | ||
793 | /* Test check bytes. */ | |
794 | ||
795 | if (len != buffer_len(&incoming_packet)) | |
796 | packet_disconnect("packet_read_poll: len %d != buffer_len %d.", | |
7e7327a1 | 797 | len, buffer_len(&incoming_packet)); |
5260325f | 798 | |
799 | ucp = (unsigned char *) buffer_ptr(&incoming_packet) + len - 4; | |
800 | stored_checksum = GET_32BIT(ucp); | |
801 | if (checksum != stored_checksum) | |
802 | packet_disconnect("Corrupted check bytes on input."); | |
803 | buffer_consume_end(&incoming_packet, 4); | |
804 | ||
805 | /* If using packet compression, decompress the packet. */ | |
806 | if (packet_compression) { | |
807 | buffer_clear(&compression_buffer); | |
808 | buffer_uncompress(&incoming_packet, &compression_buffer); | |
809 | buffer_clear(&incoming_packet); | |
810 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), | |
7e7327a1 | 811 | buffer_len(&compression_buffer)); |
5260325f | 812 | } |
813 | /* Get packet type. */ | |
814 | buffer_get(&incoming_packet, &buf[0], 1); | |
815 | ||
816 | /* Return length of payload (without type field). */ | |
817 | *payload_len_ptr = buffer_len(&incoming_packet); | |
818 | ||
5260325f | 819 | /* Return type. */ |
820 | return (unsigned char) buf[0]; | |
821 | } | |
822 | ||
7e7327a1 | 823 | int |
824 | packet_read_poll2(int *payload_len_ptr) | |
825 | { | |
826 | unsigned int padlen, need; | |
827 | unsigned char buf[8], *macbuf; | |
828 | unsigned char *ucp; | |
829 | char *cp; | |
830 | static unsigned int packet_length = 0; | |
831 | static unsigned int seqnr = 0; | |
832 | int type; | |
833 | int maclen, block_size; | |
834 | Enc *enc = NULL; | |
835 | Mac *mac = NULL; | |
836 | Comp *comp = NULL; | |
837 | ||
838 | if (kex != NULL) { | |
839 | enc = &kex->enc[MODE_IN]; | |
840 | mac = &kex->mac[MODE_IN]; | |
841 | comp = &kex->comp[MODE_IN]; | |
842 | } | |
843 | maclen = mac && mac->enabled ? mac->mac_len : 0; | |
844 | block_size = enc ? enc->block_size : 8; | |
845 | ||
846 | if (packet_length == 0) { | |
847 | /* | |
848 | * check if input size is less than the cipher block size, | |
849 | * decrypt first block and extract length of incoming packet | |
850 | */ | |
851 | if (buffer_len(&input) < block_size) | |
852 | return SSH_MSG_NONE; | |
853 | buffer_clear(&incoming_packet); | |
854 | buffer_append_space(&incoming_packet, &cp, block_size); | |
855 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), | |
856 | block_size); | |
857 | ucp = (unsigned char *) buffer_ptr(&incoming_packet); | |
858 | packet_length = GET_32BIT(ucp); | |
859 | if (packet_length < 1 + 4 || packet_length > 256 * 1024) { | |
860 | buffer_dump(&incoming_packet); | |
861 | packet_disconnect("Bad packet length %d.", packet_length); | |
862 | } | |
863 | DBG(debug("input: packet len %d", packet_length+4)); | |
864 | buffer_consume(&input, block_size); | |
865 | } | |
866 | /* we have a partial packet of block_size bytes */ | |
867 | need = 4 + packet_length - block_size; | |
868 | DBG(debug("partial packet %d, need %d, maclen %d", block_size, | |
869 | need, maclen)); | |
870 | if (need % block_size != 0) | |
871 | fatal("padding error: need %d block %d mod %d", | |
872 | need, block_size, need % block_size); | |
873 | /* | |
874 | * check if the entire packet has been received and | |
875 | * decrypt into incoming_packet | |
876 | */ | |
877 | if (buffer_len(&input) < need + maclen) | |
878 | return SSH_MSG_NONE; | |
879 | #ifdef PACKET_DEBUG | |
880 | fprintf(stderr, "read_poll enc/full: "); | |
881 | buffer_dump(&input); | |
882 | #endif | |
883 | buffer_append_space(&incoming_packet, &cp, need); | |
884 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), need); | |
885 | buffer_consume(&input, need); | |
886 | /* | |
887 | * compute MAC over seqnr and packet, | |
888 | * increment sequence number for incoming packet | |
889 | */ | |
6ae2364d | 890 | if (mac && mac->enabled) { |
7e7327a1 | 891 | macbuf = hmac( mac->md, seqnr, |
892 | (unsigned char *) buffer_ptr(&incoming_packet), | |
893 | buffer_len(&incoming_packet), | |
894 | mac->key, mac->key_len | |
895 | ); | |
896 | if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0) | |
897 | packet_disconnect("Corrupted HMAC on input."); | |
898 | DBG(debug("HMAC #%d ok", seqnr)); | |
899 | buffer_consume(&input, mac->mac_len); | |
900 | } | |
6ae2364d | 901 | if (++seqnr == 0) |
902 | log("incoming seqnr wraps around"); | |
7e7327a1 | 903 | |
904 | /* get padlen */ | |
905 | cp = buffer_ptr(&incoming_packet) + 4; | |
906 | padlen = *cp & 0xff; | |
907 | DBG(debug("input: padlen %d", padlen)); | |
908 | if (padlen < 4) | |
909 | packet_disconnect("Corrupted padlen %d on input.", padlen); | |
910 | ||
911 | /* skip packet size + padlen, discard padding */ | |
912 | buffer_consume(&incoming_packet, 4 + 1); | |
913 | buffer_consume_end(&incoming_packet, padlen); | |
914 | ||
915 | DBG(debug("input: len before de-compress %d", buffer_len(&incoming_packet))); | |
916 | if (comp && comp->enabled) { | |
917 | buffer_clear(&compression_buffer); | |
918 | buffer_uncompress(&incoming_packet, &compression_buffer); | |
919 | buffer_clear(&incoming_packet); | |
920 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), | |
921 | buffer_len(&compression_buffer)); | |
922 | DBG(debug("input: len after de-compress %d", buffer_len(&incoming_packet))); | |
923 | } | |
924 | /* | |
925 | * get packet type, implies consume. | |
926 | * return length of payload (without type field) | |
927 | */ | |
928 | buffer_get(&incoming_packet, (char *)&buf[0], 1); | |
929 | *payload_len_ptr = buffer_len(&incoming_packet); | |
930 | ||
931 | /* reset for next packet */ | |
932 | packet_length = 0; | |
933 | ||
934 | /* extract packet type */ | |
935 | type = (unsigned char)buf[0]; | |
936 | ||
937 | if (type == SSH2_MSG_NEWKEYS) { | |
938 | if (kex==NULL || mac==NULL || enc==NULL || comp==NULL) | |
939 | fatal("packet_read_poll2: no KEX"); | |
940 | if (mac->md != NULL) | |
941 | mac->enabled = 1; | |
3189621b | 942 | DBG(debug("cipher_set_key_iv receive_context")); |
7e7327a1 | 943 | cipher_set_key_iv(&receive_context, enc->type, |
944 | enc->key, enc->key_len, | |
945 | enc->iv, enc->iv_len); | |
946 | clear_enc_keys(enc, kex->we_need); | |
947 | if (comp->type != 0 && comp->enabled == 0) { | |
948 | comp->enabled = 1; | |
949 | if (! packet_compression) | |
950 | packet_start_compression(6); | |
951 | } | |
952 | } | |
953 | ||
954 | #ifdef PACKET_DEBUG | |
955 | fprintf(stderr, "read/plain[%d]:\r\n",type); | |
956 | buffer_dump(&incoming_packet); | |
957 | #endif | |
958 | return (unsigned char)type; | |
959 | } | |
960 | ||
961 | int | |
962 | packet_read_poll(int *payload_len_ptr) | |
963 | { | |
964 | char *msg; | |
965 | for (;;) { | |
966 | int type = use_ssh2_packet_format ? | |
967 | packet_read_poll2(payload_len_ptr): | |
968 | packet_read_poll1(payload_len_ptr); | |
969 | ||
970 | if(compat20) { | |
971 | int reason; | |
972 | if (type != 0) | |
973 | DBG(debug("received packet type %d", type)); | |
974 | switch(type) { | |
975 | case SSH2_MSG_IGNORE: | |
976 | break; | |
977 | case SSH2_MSG_DEBUG: | |
978 | packet_get_char(); | |
979 | msg = packet_get_string(NULL); | |
980 | debug("Remote: %.900s", msg); | |
981 | xfree(msg); | |
982 | msg = packet_get_string(NULL); | |
983 | xfree(msg); | |
984 | break; | |
985 | case SSH2_MSG_DISCONNECT: | |
986 | reason = packet_get_int(); | |
987 | msg = packet_get_string(NULL); | |
988 | log("Received disconnect: %d: %.900s", reason, msg); | |
989 | xfree(msg); | |
990 | fatal_cleanup(); | |
991 | break; | |
992 | default: | |
993 | return type; | |
994 | break; | |
995 | } | |
996 | } else { | |
997 | switch(type) { | |
998 | case SSH_MSG_IGNORE: | |
999 | break; | |
1000 | case SSH_MSG_DEBUG: | |
1001 | msg = packet_get_string(NULL); | |
1002 | debug("Remote: %.900s", msg); | |
1003 | xfree(msg); | |
1004 | break; | |
1005 | case SSH_MSG_DISCONNECT: | |
1006 | msg = packet_get_string(NULL); | |
1007 | log("Received disconnect: %.900s", msg); | |
1008 | fatal_cleanup(); | |
1009 | xfree(msg); | |
1010 | break; | |
1011 | default: | |
1012 | if (type != 0) | |
1013 | DBG(debug("received packet type %d", type)); | |
1014 | return type; | |
1015 | break; | |
1016 | } | |
1017 | } | |
1018 | } | |
1019 | } | |
1020 | ||
aa3378df | 1021 | /* |
1022 | * Buffers the given amount of input characters. This is intended to be used | |
1023 | * together with packet_read_poll. | |
1024 | */ | |
8efc0c15 | 1025 | |
1026 | void | |
1027 | packet_process_incoming(const char *buf, unsigned int len) | |
1028 | { | |
5260325f | 1029 | buffer_append(&input, buf, len); |
8efc0c15 | 1030 | } |
1031 | ||
1032 | /* Returns a character from the packet. */ | |
1033 | ||
1034 | unsigned int | |
1035 | packet_get_char() | |
1036 | { | |
5260325f | 1037 | char ch; |
1038 | buffer_get(&incoming_packet, &ch, 1); | |
1039 | return (unsigned char) ch; | |
8efc0c15 | 1040 | } |
1041 | ||
1042 | /* Returns an integer from the packet data. */ | |
1043 | ||
1044 | unsigned int | |
1045 | packet_get_int() | |
1046 | { | |
5260325f | 1047 | return buffer_get_int(&incoming_packet); |
8efc0c15 | 1048 | } |
1049 | ||
aa3378df | 1050 | /* |
1051 | * Returns an arbitrary precision integer from the packet data. The integer | |
1052 | * must have been initialized before this call. | |
1053 | */ | |
8efc0c15 | 1054 | |
1055 | void | |
5260325f | 1056 | packet_get_bignum(BIGNUM * value, int *length_ptr) |
8efc0c15 | 1057 | { |
5260325f | 1058 | *length_ptr = buffer_get_bignum(&incoming_packet, value); |
8efc0c15 | 1059 | } |
1060 | ||
7e7327a1 | 1061 | void |
1062 | packet_get_bignum2(BIGNUM * value, int *length_ptr) | |
1063 | { | |
1064 | *length_ptr = buffer_get_bignum2(&incoming_packet, value); | |
1065 | } | |
1066 | ||
1067 | char * | |
1068 | packet_get_raw(int *length_ptr) | |
1069 | { | |
1070 | int bytes = buffer_len(&incoming_packet); | |
1071 | if (length_ptr != NULL) | |
1072 | *length_ptr = bytes; | |
1073 | return buffer_ptr(&incoming_packet); | |
1074 | } | |
1075 | ||
6ae2364d | 1076 | int |
1077 | packet_remaining(void) | |
1078 | { | |
1079 | return buffer_len(&incoming_packet); | |
1080 | } | |
1081 | ||
aa3378df | 1082 | /* |
1083 | * Returns a string from the packet data. The string is allocated using | |
1084 | * xmalloc; it is the responsibility of the calling program to free it when | |
1085 | * no longer needed. The length_ptr argument may be NULL, or point to an | |
1086 | * integer into which the length of the string is stored. | |
1087 | */ | |
8efc0c15 | 1088 | |
aa3378df | 1089 | char * |
5260325f | 1090 | packet_get_string(unsigned int *length_ptr) |
8efc0c15 | 1091 | { |
5260325f | 1092 | return buffer_get_string(&incoming_packet, length_ptr); |
8efc0c15 | 1093 | } |
1094 | ||
aa3378df | 1095 | /* |
1096 | * Sends a diagnostic message from the server to the client. This message | |
1097 | * can be sent at any time (but not while constructing another message). The | |
1098 | * message is printed immediately, but only if the client is being executed | |
1099 | * in verbose mode. These messages are primarily intended to ease debugging | |
1100 | * authentication problems. The length of the formatted message must not | |
1101 | * exceed 1024 bytes. This will automatically call packet_write_wait. | |
1102 | */ | |
8efc0c15 | 1103 | |
1104 | void | |
5260325f | 1105 | packet_send_debug(const char *fmt,...) |
8efc0c15 | 1106 | { |
5260325f | 1107 | char buf[1024]; |
1108 | va_list args; | |
1109 | ||
1110 | va_start(args, fmt); | |
1111 | vsnprintf(buf, sizeof(buf), fmt, args); | |
1112 | va_end(args); | |
1113 | ||
c4bc58eb | 1114 | if (compat20) { |
1115 | packet_start(SSH2_MSG_DEBUG); | |
1116 | packet_put_char(0); /* bool: always display */ | |
1117 | packet_put_cstring(buf); | |
1118 | packet_put_cstring(""); | |
1119 | } else { | |
1120 | packet_start(SSH_MSG_DEBUG); | |
1121 | packet_put_cstring(buf); | |
1122 | } | |
5260325f | 1123 | packet_send(); |
1124 | packet_write_wait(); | |
8efc0c15 | 1125 | } |
1126 | ||
aa3378df | 1127 | /* |
1128 | * Logs the error plus constructs and sends a disconnect packet, closes the | |
1129 | * connection, and exits. This function never returns. The error message | |
1130 | * should not contain a newline. The length of the formatted message must | |
1131 | * not exceed 1024 bytes. | |
1132 | */ | |
8efc0c15 | 1133 | |
1134 | void | |
5260325f | 1135 | packet_disconnect(const char *fmt,...) |
1136 | { | |
1137 | char buf[1024]; | |
1138 | va_list args; | |
1139 | static int disconnecting = 0; | |
1140 | if (disconnecting) /* Guard against recursive invocations. */ | |
1141 | fatal("packet_disconnect called recursively."); | |
1142 | disconnecting = 1; | |
1143 | ||
aa3378df | 1144 | /* |
1145 | * Format the message. Note that the caller must make sure the | |
1146 | * message is of limited size. | |
1147 | */ | |
5260325f | 1148 | va_start(args, fmt); |
1149 | vsnprintf(buf, sizeof(buf), fmt, args); | |
1150 | va_end(args); | |
1151 | ||
1152 | /* Send the disconnect message to the other side, and wait for it to get sent. */ | |
7e7327a1 | 1153 | if (compat20) { |
1154 | packet_start(SSH2_MSG_DISCONNECT); | |
1155 | packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR); | |
1156 | packet_put_cstring(buf); | |
1157 | packet_put_cstring(""); | |
1158 | } else { | |
1159 | packet_start(SSH_MSG_DISCONNECT); | |
1160 | packet_put_string(buf, strlen(buf)); | |
1161 | } | |
5260325f | 1162 | packet_send(); |
1163 | packet_write_wait(); | |
1164 | ||
1165 | /* Stop listening for connections. */ | |
1166 | channel_stop_listening(); | |
1167 | ||
1168 | /* Close the connection. */ | |
1169 | packet_close(); | |
1170 | ||
1171 | /* Display the error locally and exit. */ | |
57112b5a | 1172 | log("Disconnecting: %.100s", buf); |
1173 | fatal_cleanup(); | |
8efc0c15 | 1174 | } |
1175 | ||
aa3378df | 1176 | /* Checks if there is any buffered output, and tries to write some of the output. */ |
8efc0c15 | 1177 | |
1178 | void | |
1179 | packet_write_poll() | |
1180 | { | |
5260325f | 1181 | int len = buffer_len(&output); |
1182 | if (len > 0) { | |
1183 | len = write(connection_out, buffer_ptr(&output), len); | |
1184 | if (len <= 0) { | |
1185 | if (errno == EAGAIN) | |
1186 | return; | |
1187 | else | |
1188 | fatal("Write failed: %.100s", strerror(errno)); | |
1189 | } | |
1190 | buffer_consume(&output, len); | |
1191 | } | |
8efc0c15 | 1192 | } |
1193 | ||
aa3378df | 1194 | /* |
1195 | * Calls packet_write_poll repeatedly until all pending output data has been | |
1196 | * written. | |
1197 | */ | |
8efc0c15 | 1198 | |
1199 | void | |
1200 | packet_write_wait() | |
1201 | { | |
5260325f | 1202 | packet_write_poll(); |
1203 | while (packet_have_data_to_write()) { | |
1204 | fd_set set; | |
1205 | FD_ZERO(&set); | |
1206 | FD_SET(connection_out, &set); | |
1207 | select(connection_out + 1, NULL, &set, NULL, NULL); | |
1208 | packet_write_poll(); | |
1209 | } | |
8efc0c15 | 1210 | } |
1211 | ||
1212 | /* Returns true if there is buffered data to write to the connection. */ | |
1213 | ||
1214 | int | |
1215 | packet_have_data_to_write() | |
1216 | { | |
5260325f | 1217 | return buffer_len(&output) != 0; |
8efc0c15 | 1218 | } |
1219 | ||
1220 | /* Returns true if there is not too much data to write to the connection. */ | |
1221 | ||
1222 | int | |
1223 | packet_not_very_much_data_to_write() | |
1224 | { | |
5260325f | 1225 | if (interactive_mode) |
1226 | return buffer_len(&output) < 16384; | |
1227 | else | |
1228 | return buffer_len(&output) < 128 * 1024; | |
8efc0c15 | 1229 | } |
1230 | ||
1231 | /* Informs that the current session is interactive. Sets IP flags for that. */ | |
1232 | ||
1233 | void | |
1234 | packet_set_interactive(int interactive, int keepalives) | |
1235 | { | |
5260325f | 1236 | int on = 1; |
1237 | ||
1238 | /* Record that we are in interactive mode. */ | |
1239 | interactive_mode = interactive; | |
1240 | ||
48e671d5 | 1241 | /* Only set socket options if using a socket. */ |
1242 | if (!packet_connection_is_on_socket()) | |
5260325f | 1243 | return; |
5260325f | 1244 | if (keepalives) { |
1245 | /* Set keepalives if requested. */ | |
1246 | if (setsockopt(connection_in, SOL_SOCKET, SO_KEEPALIVE, (void *) &on, | |
48e671d5 | 1247 | sizeof(on)) < 0) |
5260325f | 1248 | error("setsockopt SO_KEEPALIVE: %.100s", strerror(errno)); |
1249 | } | |
48e671d5 | 1250 | /* |
1251 | * IPTOS_LOWDELAY, TCP_NODELAY and IPTOS_THROUGHPUT are IPv4 only | |
1252 | */ | |
1253 | if (!packet_connection_is_ipv4()) | |
1254 | return; | |
5260325f | 1255 | if (interactive) { |
aa3378df | 1256 | /* |
1257 | * Set IP options for an interactive connection. Use | |
1258 | * IPTOS_LOWDELAY and TCP_NODELAY. | |
1259 | */ | |
132dd316 | 1260 | #if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) |
5260325f | 1261 | int lowdelay = IPTOS_LOWDELAY; |
1262 | if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &lowdelay, | |
48e671d5 | 1263 | sizeof(lowdelay)) < 0) |
5260325f | 1264 | error("setsockopt IPTOS_LOWDELAY: %.100s", strerror(errno)); |
c04f75f1 | 1265 | #endif |
5260325f | 1266 | if (setsockopt(connection_in, IPPROTO_TCP, TCP_NODELAY, (void *) &on, |
48e671d5 | 1267 | sizeof(on)) < 0) |
5260325f | 1268 | error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); |
1269 | } else { | |
aa3378df | 1270 | /* |
1271 | * Set IP options for a non-interactive connection. Use | |
1272 | * IPTOS_THROUGHPUT. | |
1273 | */ | |
132dd316 | 1274 | #if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) |
5260325f | 1275 | int throughput = IPTOS_THROUGHPUT; |
1276 | if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &throughput, | |
48e671d5 | 1277 | sizeof(throughput)) < 0) |
5260325f | 1278 | error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno)); |
c04f75f1 | 1279 | #endif |
5260325f | 1280 | } |
8efc0c15 | 1281 | } |
1282 | ||
1283 | /* Returns true if the current connection is interactive. */ | |
1284 | ||
1285 | int | |
1286 | packet_is_interactive() | |
1287 | { | |
5260325f | 1288 | return interactive_mode; |
8efc0c15 | 1289 | } |
9d6b7add | 1290 | |
1291 | int | |
1292 | packet_set_maxsize(int s) | |
1293 | { | |
5260325f | 1294 | static int called = 0; |
1295 | if (called) { | |
7e7327a1 | 1296 | log("packet_set_maxsize: called twice: old %d new %d", |
1297 | max_packet_size, s); | |
5260325f | 1298 | return -1; |
1299 | } | |
1300 | if (s < 4 * 1024 || s > 1024 * 1024) { | |
1301 | log("packet_set_maxsize: bad size %d", s); | |
1302 | return -1; | |
1303 | } | |
1304 | log("packet_set_maxsize: setting to %d", s); | |
1305 | max_packet_size = s; | |
1306 | return s; | |
9d6b7add | 1307 | } |