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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" | |
fd193ca4 | 40 | RCSID("$OpenBSD: packet.c,v 1.51 2001/02/12 22:56:09 deraadt Exp $"); |
8efc0c15 | 41 | |
42 | #include "xmalloc.h" | |
43 | #include "buffer.h" | |
44 | #include "packet.h" | |
45 | #include "bufaux.h" | |
8efc0c15 | 46 | #include "crc32.h" |
8efc0c15 | 47 | #include "getput.h" |
48 | ||
49 | #include "compress.h" | |
50 | #include "deattack.h" | |
7368a6c8 | 51 | #include "channels.h" |
8efc0c15 | 52 | |
7e7327a1 | 53 | #include "compat.h" |
42f11eb2 | 54 | #include "ssh1.h" |
7e7327a1 | 55 | #include "ssh2.h" |
56 | ||
94ec8c6b | 57 | #include "cipher.h" |
7e7327a1 | 58 | #include "kex.h" |
b2552997 | 59 | #include "mac.h" |
42f11eb2 | 60 | #include "log.h" |
61 | #include "canohost.h" | |
7e7327a1 | 62 | |
63 | #ifdef PACKET_DEBUG | |
64 | #define DBG(x) x | |
65 | #else | |
66 | #define DBG(x) | |
67 | #endif | |
68 | ||
aa3378df | 69 | /* |
70 | * This variable contains the file descriptors used for communicating with | |
71 | * the other side. connection_in is used for reading; connection_out for | |
72 | * writing. These can be the same descriptor, in which case it is assumed to | |
73 | * be a socket. | |
74 | */ | |
8efc0c15 | 75 | static int connection_in = -1; |
76 | static int connection_out = -1; | |
77 | ||
aa3378df | 78 | /* |
79 | * Cipher type. This value is only used to determine whether to pad the | |
80 | * packets with zeroes or random data. | |
81 | */ | |
8efc0c15 | 82 | static int cipher_type = SSH_CIPHER_NONE; |
83 | ||
84 | /* Protocol flags for the remote side. */ | |
1e3b8b07 | 85 | static u_int remote_protocol_flags = 0; |
8efc0c15 | 86 | |
87 | /* Encryption context for receiving data. This is only used for decryption. */ | |
88 | static CipherContext receive_context; | |
5260325f | 89 | |
90 | /* Encryption context for sending data. This is only used for encryption. */ | |
8efc0c15 | 91 | static CipherContext send_context; |
92 | ||
93 | /* Buffer for raw input data from the socket. */ | |
94 | static Buffer input; | |
95 | ||
96 | /* Buffer for raw output data going to the socket. */ | |
97 | static Buffer output; | |
98 | ||
99 | /* Buffer for the partial outgoing packet being constructed. */ | |
100 | static Buffer outgoing_packet; | |
101 | ||
102 | /* Buffer for the incoming packet currently being processed. */ | |
103 | static Buffer incoming_packet; | |
104 | ||
105 | /* Scratch buffer for packet compression/decompression. */ | |
106 | static Buffer compression_buffer; | |
107 | ||
108 | /* Flag indicating whether packet compression/decompression is enabled. */ | |
109 | static int packet_compression = 0; | |
110 | ||
9d6b7add | 111 | /* default maximum packet size */ |
112 | int max_packet_size = 32768; | |
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 | ||
7e7327a1 | 120 | /* True if SSH2 packet format is used */ |
121 | int use_ssh2_packet_format = 0; | |
122 | ||
123 | /* Session key information for Encryption and MAC */ | |
124 | Kex *kex = NULL; | |
125 | ||
126 | void | |
127 | packet_set_kex(Kex *k) | |
128 | { | |
129 | if( k->mac[MODE_IN ].key == NULL || | |
130 | k->enc[MODE_IN ].key == NULL || | |
131 | k->enc[MODE_IN ].iv == NULL || | |
132 | k->mac[MODE_OUT].key == NULL || | |
133 | k->enc[MODE_OUT].key == NULL || | |
134 | k->enc[MODE_OUT].iv == NULL) | |
135 | fatal("bad KEX"); | |
136 | kex = k; | |
137 | } | |
138 | void | |
139 | clear_enc_keys(Enc *enc, int len) | |
140 | { | |
141 | memset(enc->iv, 0, len); | |
142 | memset(enc->key, 0, len); | |
143 | xfree(enc->iv); | |
144 | xfree(enc->key); | |
145 | enc->iv = NULL; | |
146 | enc->key = NULL; | |
147 | } | |
148 | void | |
149 | packet_set_ssh2_format(void) | |
150 | { | |
3189621b | 151 | DBG(debug("use_ssh2_packet_format")); |
7e7327a1 | 152 | use_ssh2_packet_format = 1; |
153 | } | |
154 | ||
aa3378df | 155 | /* |
156 | * Sets the descriptors used for communication. Disables encryption until | |
157 | * packet_set_encryption_key is called. | |
158 | */ | |
8efc0c15 | 159 | void |
160 | packet_set_connection(int fd_in, int fd_out) | |
161 | { | |
94ec8c6b | 162 | Cipher *none = cipher_by_name("none"); |
163 | if (none == NULL) | |
164 | fatal("packet_set_connection: cannot load cipher 'none'"); | |
5260325f | 165 | connection_in = fd_in; |
166 | connection_out = fd_out; | |
167 | cipher_type = SSH_CIPHER_NONE; | |
1e3b8b07 | 168 | cipher_init(&send_context, none, (u_char *) "", 0, NULL, 0); |
169 | cipher_init(&receive_context, none, (u_char *) "", 0, NULL, 0); | |
5260325f | 170 | if (!initialized) { |
171 | initialized = 1; | |
172 | buffer_init(&input); | |
173 | buffer_init(&output); | |
174 | buffer_init(&outgoing_packet); | |
175 | buffer_init(&incoming_packet); | |
176 | } | |
177 | /* Kludge: arrange the close function to be called from fatal(). */ | |
178 | fatal_add_cleanup((void (*) (void *)) packet_close, NULL); | |
8efc0c15 | 179 | } |
180 | ||
48e671d5 | 181 | /* Returns 1 if remote host is connected via socket, 0 if not. */ |
182 | ||
183 | int | |
184 | packet_connection_is_on_socket() | |
185 | { | |
186 | struct sockaddr_storage from, to; | |
187 | socklen_t fromlen, tolen; | |
188 | ||
189 | /* filedescriptors in and out are the same, so it's a socket */ | |
190 | if (connection_in == connection_out) | |
191 | return 1; | |
192 | fromlen = sizeof(from); | |
193 | memset(&from, 0, sizeof(from)); | |
9bc5ddfe | 194 | if (getpeername(connection_in, (struct sockaddr *)&from, &fromlen) < 0) |
48e671d5 | 195 | return 0; |
196 | tolen = sizeof(to); | |
197 | memset(&to, 0, sizeof(to)); | |
9bc5ddfe | 198 | if (getpeername(connection_out, (struct sockaddr *)&to, &tolen) < 0) |
48e671d5 | 199 | return 0; |
200 | if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0) | |
201 | return 0; | |
202 | if (from.ss_family != AF_INET && from.ss_family != AF_INET6) | |
203 | return 0; | |
204 | return 1; | |
205 | } | |
206 | ||
207 | /* returns 1 if connection is via ipv4 */ | |
208 | ||
209 | int | |
210 | packet_connection_is_ipv4() | |
211 | { | |
212 | struct sockaddr_storage to; | |
d45317d8 | 213 | socklen_t tolen = sizeof(to); |
48e671d5 | 214 | |
215 | memset(&to, 0, sizeof(to)); | |
216 | if (getsockname(connection_out, (struct sockaddr *)&to, &tolen) < 0) | |
217 | return 0; | |
218 | if (to.ss_family != AF_INET) | |
219 | return 0; | |
220 | return 1; | |
221 | } | |
222 | ||
8efc0c15 | 223 | /* Sets the connection into non-blocking mode. */ |
224 | ||
225 | void | |
226 | packet_set_nonblocking() | |
227 | { | |
5260325f | 228 | /* Set the socket into non-blocking mode. */ |
229 | if (fcntl(connection_in, F_SETFL, O_NONBLOCK) < 0) | |
230 | error("fcntl O_NONBLOCK: %.100s", strerror(errno)); | |
8efc0c15 | 231 | |
5260325f | 232 | if (connection_out != connection_in) { |
233 | if (fcntl(connection_out, F_SETFL, O_NONBLOCK) < 0) | |
234 | error("fcntl O_NONBLOCK: %.100s", strerror(errno)); | |
235 | } | |
8efc0c15 | 236 | } |
237 | ||
238 | /* Returns the socket used for reading. */ | |
239 | ||
240 | int | |
241 | packet_get_connection_in() | |
242 | { | |
5260325f | 243 | return connection_in; |
8efc0c15 | 244 | } |
245 | ||
246 | /* Returns the descriptor used for writing. */ | |
247 | ||
248 | int | |
249 | packet_get_connection_out() | |
250 | { | |
5260325f | 251 | return connection_out; |
8efc0c15 | 252 | } |
253 | ||
254 | /* Closes the connection and clears and frees internal data structures. */ | |
255 | ||
256 | void | |
257 | packet_close() | |
258 | { | |
5260325f | 259 | if (!initialized) |
260 | return; | |
261 | initialized = 0; | |
262 | if (connection_in == connection_out) { | |
263 | shutdown(connection_out, SHUT_RDWR); | |
264 | close(connection_out); | |
265 | } else { | |
266 | close(connection_in); | |
267 | close(connection_out); | |
268 | } | |
269 | buffer_free(&input); | |
270 | buffer_free(&output); | |
271 | buffer_free(&outgoing_packet); | |
272 | buffer_free(&incoming_packet); | |
273 | if (packet_compression) { | |
274 | buffer_free(&compression_buffer); | |
275 | buffer_compress_uninit(); | |
276 | } | |
8efc0c15 | 277 | } |
278 | ||
279 | /* Sets remote side protocol flags. */ | |
280 | ||
281 | void | |
1e3b8b07 | 282 | packet_set_protocol_flags(u_int protocol_flags) |
8efc0c15 | 283 | { |
5260325f | 284 | remote_protocol_flags = protocol_flags; |
285 | channel_set_options((protocol_flags & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) != 0); | |
8efc0c15 | 286 | } |
287 | ||
288 | /* Returns the remote protocol flags set earlier by the above function. */ | |
289 | ||
1e3b8b07 | 290 | u_int |
8efc0c15 | 291 | packet_get_protocol_flags() |
292 | { | |
5260325f | 293 | return remote_protocol_flags; |
8efc0c15 | 294 | } |
295 | ||
aa3378df | 296 | /* |
297 | * Starts packet compression from the next packet on in both directions. | |
298 | * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip. | |
299 | */ | |
8efc0c15 | 300 | |
7e7327a1 | 301 | /*** XXXXX todo: kex means re-init */ |
8efc0c15 | 302 | void |
303 | packet_start_compression(int level) | |
304 | { | |
5260325f | 305 | if (packet_compression) |
306 | fatal("Compression already enabled."); | |
307 | packet_compression = 1; | |
308 | buffer_init(&compression_buffer); | |
309 | buffer_compress_init(level); | |
8efc0c15 | 310 | } |
311 | ||
aa3378df | 312 | /* |
313 | * Encrypts the given number of bytes, copying from src to dest. bytes is | |
314 | * known to be a multiple of 8. | |
315 | */ | |
8efc0c15 | 316 | |
317 | void | |
5260325f | 318 | packet_encrypt(CipherContext * cc, void *dest, void *src, |
1e3b8b07 | 319 | u_int bytes) |
8efc0c15 | 320 | { |
5260325f | 321 | cipher_encrypt(cc, dest, src, bytes); |
8efc0c15 | 322 | } |
323 | ||
aa3378df | 324 | /* |
325 | * Decrypts the given number of bytes, copying from src to dest. bytes is | |
326 | * known to be a multiple of 8. | |
327 | */ | |
8efc0c15 | 328 | |
329 | void | |
1e3b8b07 | 330 | packet_decrypt(CipherContext *context, void *dest, void *src, u_int bytes) |
8efc0c15 | 331 | { |
aa3378df | 332 | /* |
333 | * Cryptographic attack detector for ssh - Modifications for packet.c | |
334 | * (C)1998 CORE-SDI, Buenos Aires Argentina Ariel Futoransky(futo@core-sdi.com) | |
335 | */ | |
94ec8c6b | 336 | if (!compat20 && |
337 | context->cipher->number != SSH_CIPHER_NONE && | |
338 | detect_attack(src, bytes, NULL) == DEATTACK_DETECTED) | |
5260325f | 339 | packet_disconnect("crc32 compensation attack: network attack detected"); |
340 | ||
94ec8c6b | 341 | cipher_decrypt(context, dest, src, bytes); |
8efc0c15 | 342 | } |
343 | ||
aa3378df | 344 | /* |
345 | * Causes any further packets to be encrypted using the given key. The same | |
346 | * key is used for both sending and reception. However, both directions are | |
347 | * encrypted independently of each other. | |
348 | */ | |
8efc0c15 | 349 | |
350 | void | |
1e3b8b07 | 351 | packet_set_encryption_key(const u_char *key, u_int keylen, |
94ec8c6b | 352 | int number) |
8efc0c15 | 353 | { |
94ec8c6b | 354 | Cipher *cipher = cipher_by_number(number); |
355 | if (cipher == NULL) | |
356 | fatal("packet_set_encryption_key: unknown cipher number %d", number); | |
7e7327a1 | 357 | if (keylen < 20) |
94ec8c6b | 358 | fatal("packet_set_encryption_key: keylen too small: %d", keylen); |
359 | cipher_init(&receive_context, cipher, key, keylen, NULL, 0); | |
360 | cipher_init(&send_context, cipher, key, keylen, NULL, 0); | |
8efc0c15 | 361 | } |
362 | ||
363 | /* Starts constructing a packet to send. */ | |
364 | ||
365 | void | |
7e7327a1 | 366 | packet_start1(int type) |
8efc0c15 | 367 | { |
5260325f | 368 | char buf[9]; |
8efc0c15 | 369 | |
5260325f | 370 | buffer_clear(&outgoing_packet); |
371 | memset(buf, 0, 8); | |
372 | buf[8] = type; | |
373 | buffer_append(&outgoing_packet, buf, 9); | |
8efc0c15 | 374 | } |
375 | ||
7e7327a1 | 376 | void |
377 | packet_start2(int type) | |
378 | { | |
379 | char buf[4+1+1]; | |
380 | ||
381 | buffer_clear(&outgoing_packet); | |
382 | memset(buf, 0, sizeof buf); | |
383 | /* buf[0..3] = payload_len; */ | |
384 | /* buf[4] = pad_len; */ | |
385 | buf[5] = type & 0xff; | |
386 | buffer_append(&outgoing_packet, buf, sizeof buf); | |
387 | } | |
388 | ||
389 | void | |
390 | packet_start(int type) | |
391 | { | |
392 | DBG(debug("packet_start[%d]",type)); | |
393 | if (use_ssh2_packet_format) | |
394 | packet_start2(type); | |
395 | else | |
396 | packet_start1(type); | |
397 | } | |
398 | ||
8efc0c15 | 399 | /* Appends a character to the packet data. */ |
400 | ||
401 | void | |
402 | packet_put_char(int value) | |
403 | { | |
5260325f | 404 | char ch = value; |
405 | buffer_append(&outgoing_packet, &ch, 1); | |
8efc0c15 | 406 | } |
407 | ||
408 | /* Appends an integer to the packet data. */ | |
409 | ||
410 | void | |
1e3b8b07 | 411 | packet_put_int(u_int value) |
8efc0c15 | 412 | { |
5260325f | 413 | buffer_put_int(&outgoing_packet, value); |
8efc0c15 | 414 | } |
415 | ||
416 | /* Appends a string to packet data. */ | |
417 | ||
418 | void | |
1e3b8b07 | 419 | packet_put_string(const char *buf, u_int len) |
8efc0c15 | 420 | { |
5260325f | 421 | buffer_put_string(&outgoing_packet, buf, len); |
8efc0c15 | 422 | } |
7e7327a1 | 423 | void |
424 | packet_put_cstring(const char *str) | |
425 | { | |
426 | buffer_put_string(&outgoing_packet, str, strlen(str)); | |
427 | } | |
428 | ||
429 | void | |
1e3b8b07 | 430 | packet_put_raw(const char *buf, u_int len) |
7e7327a1 | 431 | { |
432 | buffer_append(&outgoing_packet, buf, len); | |
433 | } | |
434 | ||
8efc0c15 | 435 | |
436 | /* Appends an arbitrary precision integer to packet data. */ | |
437 | ||
438 | void | |
5260325f | 439 | packet_put_bignum(BIGNUM * value) |
8efc0c15 | 440 | { |
5260325f | 441 | buffer_put_bignum(&outgoing_packet, value); |
8efc0c15 | 442 | } |
7e7327a1 | 443 | void |
444 | packet_put_bignum2(BIGNUM * value) | |
445 | { | |
446 | buffer_put_bignum2(&outgoing_packet, value); | |
447 | } | |
8efc0c15 | 448 | |
aa3378df | 449 | /* |
450 | * Finalizes and sends the packet. If the encryption key has been set, | |
451 | * encrypts the packet before sending. | |
452 | */ | |
5260325f | 453 | |
8efc0c15 | 454 | void |
5ca51e19 | 455 | packet_send1(void) |
8efc0c15 | 456 | { |
5260325f | 457 | char buf[8], *cp; |
458 | int i, padding, len; | |
1e3b8b07 | 459 | u_int checksum; |
5260325f | 460 | u_int32_t rand = 0; |
461 | ||
aa3378df | 462 | /* |
463 | * If using packet compression, compress the payload of the outgoing | |
464 | * packet. | |
465 | */ | |
5260325f | 466 | if (packet_compression) { |
467 | buffer_clear(&compression_buffer); | |
468 | /* Skip padding. */ | |
469 | buffer_consume(&outgoing_packet, 8); | |
470 | /* padding */ | |
471 | buffer_append(&compression_buffer, "\0\0\0\0\0\0\0\0", 8); | |
472 | buffer_compress(&outgoing_packet, &compression_buffer); | |
473 | buffer_clear(&outgoing_packet); | |
474 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), | |
475 | buffer_len(&compression_buffer)); | |
476 | } | |
477 | /* Compute packet length without padding (add checksum, remove padding). */ | |
478 | len = buffer_len(&outgoing_packet) + 4 - 8; | |
479 | ||
1d1ffb87 | 480 | /* Insert padding. Initialized to zero in packet_start1() */ |
5260325f | 481 | padding = 8 - len % 8; |
482 | if (cipher_type != SSH_CIPHER_NONE) { | |
483 | cp = buffer_ptr(&outgoing_packet); | |
484 | for (i = 0; i < padding; i++) { | |
485 | if (i % 4 == 0) | |
486 | rand = arc4random(); | |
487 | cp[7 - i] = rand & 0xff; | |
488 | rand >>= 8; | |
489 | } | |
490 | } | |
491 | buffer_consume(&outgoing_packet, 8 - padding); | |
492 | ||
493 | /* Add check bytes. */ | |
1e3b8b07 | 494 | checksum = ssh_crc32((u_char *) buffer_ptr(&outgoing_packet), |
2e73a022 | 495 | buffer_len(&outgoing_packet)); |
5260325f | 496 | PUT_32BIT(buf, checksum); |
497 | buffer_append(&outgoing_packet, buf, 4); | |
8efc0c15 | 498 | |
499 | #ifdef PACKET_DEBUG | |
5260325f | 500 | fprintf(stderr, "packet_send plain: "); |
501 | buffer_dump(&outgoing_packet); | |
8efc0c15 | 502 | #endif |
503 | ||
5260325f | 504 | /* Append to output. */ |
505 | PUT_32BIT(buf, len); | |
506 | buffer_append(&output, buf, 4); | |
507 | buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); | |
508 | packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), | |
509 | buffer_len(&outgoing_packet)); | |
510 | ||
8efc0c15 | 511 | #ifdef PACKET_DEBUG |
5260325f | 512 | fprintf(stderr, "encrypted: "); |
513 | buffer_dump(&output); | |
8efc0c15 | 514 | #endif |
515 | ||
5260325f | 516 | buffer_clear(&outgoing_packet); |
8efc0c15 | 517 | |
aa3378df | 518 | /* |
519 | * Note that the packet is now only buffered in output. It won\'t be | |
520 | * actually sent until packet_write_wait or packet_write_poll is | |
521 | * called. | |
522 | */ | |
8efc0c15 | 523 | } |
524 | ||
7e7327a1 | 525 | /* |
526 | * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) | |
527 | */ | |
528 | void | |
5ca51e19 | 529 | packet_send2(void) |
7e7327a1 | 530 | { |
b2552997 | 531 | static u_int32_t seqnr = 0; |
1e3b8b07 | 532 | u_char *macbuf = NULL; |
7e7327a1 | 533 | char *cp; |
1e3b8b07 | 534 | u_int packet_length = 0; |
535 | u_int i, padlen, len; | |
7e7327a1 | 536 | u_int32_t rand = 0; |
7e7327a1 | 537 | int type; |
538 | Enc *enc = NULL; | |
539 | Mac *mac = NULL; | |
540 | Comp *comp = NULL; | |
541 | int block_size; | |
542 | ||
543 | if (kex != NULL) { | |
544 | enc = &kex->enc[MODE_OUT]; | |
545 | mac = &kex->mac[MODE_OUT]; | |
546 | comp = &kex->comp[MODE_OUT]; | |
547 | } | |
94ec8c6b | 548 | block_size = enc ? enc->cipher->block_size : 8; |
7e7327a1 | 549 | |
550 | cp = buffer_ptr(&outgoing_packet); | |
551 | type = cp[5] & 0xff; | |
552 | ||
553 | #ifdef PACKET_DEBUG | |
554 | fprintf(stderr, "plain: "); | |
555 | buffer_dump(&outgoing_packet); | |
556 | #endif | |
557 | ||
558 | if (comp && comp->enabled) { | |
559 | len = buffer_len(&outgoing_packet); | |
560 | /* skip header, compress only payload */ | |
561 | buffer_consume(&outgoing_packet, 5); | |
562 | buffer_clear(&compression_buffer); | |
563 | buffer_compress(&outgoing_packet, &compression_buffer); | |
564 | buffer_clear(&outgoing_packet); | |
565 | buffer_append(&outgoing_packet, "\0\0\0\0\0", 5); | |
566 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), | |
567 | buffer_len(&compression_buffer)); | |
568 | DBG(debug("compression: raw %d compressed %d", len, | |
569 | buffer_len(&outgoing_packet))); | |
570 | } | |
571 | ||
572 | /* sizeof (packet_len + pad_len + payload) */ | |
573 | len = buffer_len(&outgoing_packet); | |
574 | ||
575 | /* | |
576 | * calc size of padding, alloc space, get random data, | |
577 | * minimum padding is 4 bytes | |
578 | */ | |
579 | padlen = block_size - (len % block_size); | |
580 | if (padlen < 4) | |
581 | padlen += block_size; | |
582 | buffer_append_space(&outgoing_packet, &cp, padlen); | |
94ec8c6b | 583 | if (enc && enc->cipher->number != SSH_CIPHER_NONE) { |
1d1ffb87 | 584 | /* random padding */ |
7e7327a1 | 585 | for (i = 0; i < padlen; i++) { |
586 | if (i % 4 == 0) | |
587 | rand = arc4random(); | |
588 | cp[i] = rand & 0xff; | |
589 | rand <<= 8; | |
590 | } | |
1d1ffb87 | 591 | } else { |
592 | /* clear padding */ | |
593 | memset(cp, 0, padlen); | |
7e7327a1 | 594 | } |
595 | /* packet_length includes payload, padding and padding length field */ | |
596 | packet_length = buffer_len(&outgoing_packet) - 4; | |
597 | cp = buffer_ptr(&outgoing_packet); | |
598 | PUT_32BIT(cp, packet_length); | |
599 | cp[4] = padlen & 0xff; | |
600 | DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen)); | |
601 | ||
602 | /* compute MAC over seqnr and packet(length fields, payload, padding) */ | |
603 | if (mac && mac->enabled) { | |
b2552997 | 604 | macbuf = mac_compute(mac, seqnr, |
1e3b8b07 | 605 | (u_char *) buffer_ptr(&outgoing_packet), |
b2552997 | 606 | buffer_len(&outgoing_packet)); |
94ec8c6b | 607 | DBG(debug("done calc MAC out #%d", seqnr)); |
7e7327a1 | 608 | } |
609 | /* encrypt packet and append to output buffer. */ | |
610 | buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); | |
611 | packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), | |
612 | buffer_len(&outgoing_packet)); | |
613 | /* append unencrypted MAC */ | |
614 | if (mac && mac->enabled) | |
615 | buffer_append(&output, (char *)macbuf, mac->mac_len); | |
616 | #ifdef PACKET_DEBUG | |
617 | fprintf(stderr, "encrypted: "); | |
618 | buffer_dump(&output); | |
619 | #endif | |
6ae2364d | 620 | /* increment sequence number for outgoing packets */ |
621 | if (++seqnr == 0) | |
622 | log("outgoing seqnr wraps around"); | |
7e7327a1 | 623 | buffer_clear(&outgoing_packet); |
624 | ||
625 | if (type == SSH2_MSG_NEWKEYS) { | |
626 | if (kex==NULL || mac==NULL || enc==NULL || comp==NULL) | |
627 | fatal("packet_send2: no KEX"); | |
628 | if (mac->md != NULL) | |
629 | mac->enabled = 1; | |
94ec8c6b | 630 | DBG(debug("cipher_init send_context")); |
631 | cipher_init(&send_context, enc->cipher, | |
632 | enc->key, enc->cipher->key_len, | |
633 | enc->iv, enc->cipher->block_size); | |
7e7327a1 | 634 | clear_enc_keys(enc, kex->we_need); |
635 | if (comp->type != 0 && comp->enabled == 0) { | |
636 | comp->enabled = 1; | |
637 | if (! packet_compression) | |
638 | packet_start_compression(6); | |
639 | } | |
640 | } | |
641 | } | |
642 | ||
643 | void | |
644 | packet_send() | |
645 | { | |
646 | if (use_ssh2_packet_format) | |
647 | packet_send2(); | |
648 | else | |
649 | packet_send1(); | |
650 | DBG(debug("packet_send done")); | |
651 | } | |
652 | ||
aa3378df | 653 | /* |
654 | * Waits until a packet has been received, and returns its type. Note that | |
655 | * no other data is processed until this returns, so this function should not | |
656 | * be used during the interactive session. | |
657 | */ | |
8efc0c15 | 658 | |
659 | int | |
660 | packet_read(int *payload_len_ptr) | |
661 | { | |
5260325f | 662 | int type, len; |
663 | fd_set set; | |
664 | char buf[8192]; | |
7e7327a1 | 665 | DBG(debug("packet_read()")); |
5260325f | 666 | |
667 | /* Since we are blocking, ensure that all written packets have been sent. */ | |
668 | packet_write_wait(); | |
669 | ||
670 | /* Stay in the loop until we have received a complete packet. */ | |
671 | for (;;) { | |
672 | /* Try to read a packet from the buffer. */ | |
673 | type = packet_read_poll(payload_len_ptr); | |
1d1ffb87 | 674 | if (!use_ssh2_packet_format && ( |
675 | type == SSH_SMSG_SUCCESS | |
5260325f | 676 | || type == SSH_SMSG_FAILURE |
677 | || type == SSH_CMSG_EOF | |
1d1ffb87 | 678 | || type == SSH_CMSG_EXIT_CONFIRMATION)) |
5260325f | 679 | packet_integrity_check(*payload_len_ptr, 0, type); |
680 | /* If we got a packet, return it. */ | |
681 | if (type != SSH_MSG_NONE) | |
682 | return type; | |
aa3378df | 683 | /* |
684 | * Otherwise, wait for some data to arrive, add it to the | |
685 | * buffer, and try again. | |
686 | */ | |
5260325f | 687 | FD_ZERO(&set); |
688 | FD_SET(connection_in, &set); | |
aa3378df | 689 | |
5260325f | 690 | /* Wait for some data to arrive. */ |
fd193ca4 | 691 | while (select(connection_in + 1, &set, NULL, NULL, NULL) == -1 && |
692 | (errno == EAGAIN || errno == EINTR)) | |
693 | ; | |
aa3378df | 694 | |
5260325f | 695 | /* Read data from the socket. */ |
696 | len = read(connection_in, buf, sizeof(buf)); | |
89cafde6 | 697 | if (len == 0) { |
698 | log("Connection closed by %.200s", get_remote_ipaddr()); | |
699 | fatal_cleanup(); | |
700 | } | |
5260325f | 701 | if (len < 0) |
702 | fatal("Read from socket failed: %.100s", strerror(errno)); | |
703 | /* Append it to the buffer. */ | |
704 | packet_process_incoming(buf, len); | |
705 | } | |
706 | /* NOTREACHED */ | |
8efc0c15 | 707 | } |
708 | ||
aa3378df | 709 | /* |
710 | * Waits until a packet has been received, verifies that its type matches | |
711 | * that given, and gives a fatal error and exits if there is a mismatch. | |
712 | */ | |
8efc0c15 | 713 | |
714 | void | |
715 | packet_read_expect(int *payload_len_ptr, int expected_type) | |
716 | { | |
5260325f | 717 | int type; |
8efc0c15 | 718 | |
5260325f | 719 | type = packet_read(payload_len_ptr); |
720 | if (type != expected_type) | |
721 | packet_disconnect("Protocol error: expected packet type %d, got %d", | |
7e7327a1 | 722 | expected_type, type); |
8efc0c15 | 723 | } |
724 | ||
725 | /* Checks if a full packet is available in the data received so far via | |
5260325f | 726 | * packet_process_incoming. If so, reads the packet; otherwise returns |
727 | * SSH_MSG_NONE. This does not wait for data from the connection. | |
728 | * | |
729 | * SSH_MSG_DISCONNECT is handled specially here. Also, | |
730 | * SSH_MSG_IGNORE messages are skipped by this function and are never returned | |
731 | * to higher levels. | |
732 | * | |
733 | * The returned payload_len does include space consumed by: | |
734 | * Packet length | |
735 | * Padding | |
736 | * Packet type | |
737 | * Check bytes | |
738 | */ | |
8efc0c15 | 739 | |
740 | int | |
7e7327a1 | 741 | packet_read_poll1(int *payload_len_ptr) |
8efc0c15 | 742 | { |
1e3b8b07 | 743 | u_int len, padded_len; |
744 | u_char *ucp; | |
7e7327a1 | 745 | char buf[8], *cp; |
1e3b8b07 | 746 | u_int checksum, stored_checksum; |
5260325f | 747 | |
5260325f | 748 | /* Check if input size is less than minimum packet size. */ |
749 | if (buffer_len(&input) < 4 + 8) | |
750 | return SSH_MSG_NONE; | |
751 | /* Get length of incoming packet. */ | |
1e3b8b07 | 752 | ucp = (u_char *) buffer_ptr(&input); |
5260325f | 753 | len = GET_32BIT(ucp); |
754 | if (len < 1 + 2 + 2 || len > 256 * 1024) | |
755 | packet_disconnect("Bad packet length %d.", len); | |
756 | padded_len = (len + 8) & ~7; | |
757 | ||
758 | /* Check if the packet has been entirely received. */ | |
759 | if (buffer_len(&input) < 4 + padded_len) | |
760 | return SSH_MSG_NONE; | |
761 | ||
762 | /* The entire packet is in buffer. */ | |
763 | ||
764 | /* Consume packet length. */ | |
765 | buffer_consume(&input, 4); | |
766 | ||
767 | /* Copy data to incoming_packet. */ | |
768 | buffer_clear(&incoming_packet); | |
769 | buffer_append_space(&incoming_packet, &cp, padded_len); | |
770 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len); | |
771 | buffer_consume(&input, padded_len); | |
8efc0c15 | 772 | |
773 | #ifdef PACKET_DEBUG | |
5260325f | 774 | fprintf(stderr, "read_poll plain: "); |
775 | buffer_dump(&incoming_packet); | |
8efc0c15 | 776 | #endif |
5260325f | 777 | |
778 | /* Compute packet checksum. */ | |
1e3b8b07 | 779 | checksum = ssh_crc32((u_char *) buffer_ptr(&incoming_packet), |
7e7327a1 | 780 | buffer_len(&incoming_packet) - 4); |
5260325f | 781 | |
782 | /* Skip padding. */ | |
783 | buffer_consume(&incoming_packet, 8 - len % 8); | |
784 | ||
785 | /* Test check bytes. */ | |
786 | ||
787 | if (len != buffer_len(&incoming_packet)) | |
788 | packet_disconnect("packet_read_poll: len %d != buffer_len %d.", | |
7e7327a1 | 789 | len, buffer_len(&incoming_packet)); |
5260325f | 790 | |
1e3b8b07 | 791 | ucp = (u_char *) buffer_ptr(&incoming_packet) + len - 4; |
5260325f | 792 | stored_checksum = GET_32BIT(ucp); |
793 | if (checksum != stored_checksum) | |
794 | packet_disconnect("Corrupted check bytes on input."); | |
795 | buffer_consume_end(&incoming_packet, 4); | |
796 | ||
797 | /* If using packet compression, decompress the packet. */ | |
798 | if (packet_compression) { | |
799 | buffer_clear(&compression_buffer); | |
800 | buffer_uncompress(&incoming_packet, &compression_buffer); | |
801 | buffer_clear(&incoming_packet); | |
802 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), | |
7e7327a1 | 803 | buffer_len(&compression_buffer)); |
5260325f | 804 | } |
805 | /* Get packet type. */ | |
806 | buffer_get(&incoming_packet, &buf[0], 1); | |
807 | ||
808 | /* Return length of payload (without type field). */ | |
809 | *payload_len_ptr = buffer_len(&incoming_packet); | |
810 | ||
5260325f | 811 | /* Return type. */ |
1e3b8b07 | 812 | return (u_char) buf[0]; |
5260325f | 813 | } |
814 | ||
7e7327a1 | 815 | int |
816 | packet_read_poll2(int *payload_len_ptr) | |
817 | { | |
b2552997 | 818 | static u_int32_t seqnr = 0; |
819 | static u_int packet_length = 0; | |
1e3b8b07 | 820 | u_int padlen, need; |
821 | u_char buf[8], *macbuf; | |
822 | u_char *ucp; | |
7e7327a1 | 823 | char *cp; |
7e7327a1 | 824 | int type; |
825 | int maclen, block_size; | |
826 | Enc *enc = NULL; | |
827 | Mac *mac = NULL; | |
828 | Comp *comp = NULL; | |
829 | ||
830 | if (kex != NULL) { | |
831 | enc = &kex->enc[MODE_IN]; | |
832 | mac = &kex->mac[MODE_IN]; | |
833 | comp = &kex->comp[MODE_IN]; | |
834 | } | |
835 | maclen = mac && mac->enabled ? mac->mac_len : 0; | |
94ec8c6b | 836 | block_size = enc ? enc->cipher->block_size : 8; |
7e7327a1 | 837 | |
838 | if (packet_length == 0) { | |
839 | /* | |
840 | * check if input size is less than the cipher block size, | |
841 | * decrypt first block and extract length of incoming packet | |
842 | */ | |
843 | if (buffer_len(&input) < block_size) | |
844 | return SSH_MSG_NONE; | |
845 | buffer_clear(&incoming_packet); | |
846 | buffer_append_space(&incoming_packet, &cp, block_size); | |
847 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), | |
848 | block_size); | |
1e3b8b07 | 849 | ucp = (u_char *) buffer_ptr(&incoming_packet); |
7e7327a1 | 850 | packet_length = GET_32BIT(ucp); |
851 | if (packet_length < 1 + 4 || packet_length > 256 * 1024) { | |
852 | buffer_dump(&incoming_packet); | |
853 | packet_disconnect("Bad packet length %d.", packet_length); | |
854 | } | |
855 | DBG(debug("input: packet len %d", packet_length+4)); | |
856 | buffer_consume(&input, block_size); | |
857 | } | |
858 | /* we have a partial packet of block_size bytes */ | |
859 | need = 4 + packet_length - block_size; | |
860 | DBG(debug("partial packet %d, need %d, maclen %d", block_size, | |
861 | need, maclen)); | |
862 | if (need % block_size != 0) | |
863 | fatal("padding error: need %d block %d mod %d", | |
864 | need, block_size, need % block_size); | |
865 | /* | |
866 | * check if the entire packet has been received and | |
867 | * decrypt into incoming_packet | |
868 | */ | |
869 | if (buffer_len(&input) < need + maclen) | |
870 | return SSH_MSG_NONE; | |
871 | #ifdef PACKET_DEBUG | |
872 | fprintf(stderr, "read_poll enc/full: "); | |
873 | buffer_dump(&input); | |
874 | #endif | |
875 | buffer_append_space(&incoming_packet, &cp, need); | |
876 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), need); | |
877 | buffer_consume(&input, need); | |
878 | /* | |
879 | * compute MAC over seqnr and packet, | |
880 | * increment sequence number for incoming packet | |
881 | */ | |
6ae2364d | 882 | if (mac && mac->enabled) { |
b2552997 | 883 | macbuf = mac_compute(mac, seqnr, |
1e3b8b07 | 884 | (u_char *) buffer_ptr(&incoming_packet), |
b2552997 | 885 | buffer_len(&incoming_packet)); |
7e7327a1 | 886 | if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0) |
94ec8c6b | 887 | packet_disconnect("Corrupted MAC on input."); |
888 | DBG(debug("MAC #%d ok", seqnr)); | |
7e7327a1 | 889 | buffer_consume(&input, mac->mac_len); |
890 | } | |
6ae2364d | 891 | if (++seqnr == 0) |
892 | log("incoming seqnr wraps around"); | |
7e7327a1 | 893 | |
894 | /* get padlen */ | |
895 | cp = buffer_ptr(&incoming_packet) + 4; | |
896 | padlen = *cp & 0xff; | |
897 | DBG(debug("input: padlen %d", padlen)); | |
898 | if (padlen < 4) | |
899 | packet_disconnect("Corrupted padlen %d on input.", padlen); | |
900 | ||
901 | /* skip packet size + padlen, discard padding */ | |
902 | buffer_consume(&incoming_packet, 4 + 1); | |
903 | buffer_consume_end(&incoming_packet, padlen); | |
904 | ||
905 | DBG(debug("input: len before de-compress %d", buffer_len(&incoming_packet))); | |
906 | if (comp && comp->enabled) { | |
907 | buffer_clear(&compression_buffer); | |
908 | buffer_uncompress(&incoming_packet, &compression_buffer); | |
909 | buffer_clear(&incoming_packet); | |
910 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), | |
911 | buffer_len(&compression_buffer)); | |
912 | DBG(debug("input: len after de-compress %d", buffer_len(&incoming_packet))); | |
913 | } | |
914 | /* | |
915 | * get packet type, implies consume. | |
916 | * return length of payload (without type field) | |
917 | */ | |
918 | buffer_get(&incoming_packet, (char *)&buf[0], 1); | |
919 | *payload_len_ptr = buffer_len(&incoming_packet); | |
920 | ||
921 | /* reset for next packet */ | |
922 | packet_length = 0; | |
923 | ||
924 | /* extract packet type */ | |
1e3b8b07 | 925 | type = (u_char)buf[0]; |
7e7327a1 | 926 | |
927 | if (type == SSH2_MSG_NEWKEYS) { | |
928 | if (kex==NULL || mac==NULL || enc==NULL || comp==NULL) | |
929 | fatal("packet_read_poll2: no KEX"); | |
930 | if (mac->md != NULL) | |
931 | mac->enabled = 1; | |
94ec8c6b | 932 | DBG(debug("cipher_init receive_context")); |
933 | cipher_init(&receive_context, enc->cipher, | |
934 | enc->key, enc->cipher->key_len, | |
935 | enc->iv, enc->cipher->block_size); | |
7e7327a1 | 936 | clear_enc_keys(enc, kex->we_need); |
937 | if (comp->type != 0 && comp->enabled == 0) { | |
938 | comp->enabled = 1; | |
939 | if (! packet_compression) | |
940 | packet_start_compression(6); | |
941 | } | |
942 | } | |
943 | ||
944 | #ifdef PACKET_DEBUG | |
945 | fprintf(stderr, "read/plain[%d]:\r\n",type); | |
946 | buffer_dump(&incoming_packet); | |
947 | #endif | |
1e3b8b07 | 948 | return (u_char)type; |
7e7327a1 | 949 | } |
950 | ||
951 | int | |
952 | packet_read_poll(int *payload_len_ptr) | |
953 | { | |
954 | char *msg; | |
955 | for (;;) { | |
956 | int type = use_ssh2_packet_format ? | |
957 | packet_read_poll2(payload_len_ptr): | |
958 | packet_read_poll1(payload_len_ptr); | |
959 | ||
960 | if(compat20) { | |
961 | int reason; | |
962 | if (type != 0) | |
963 | DBG(debug("received packet type %d", type)); | |
964 | switch(type) { | |
965 | case SSH2_MSG_IGNORE: | |
966 | break; | |
967 | case SSH2_MSG_DEBUG: | |
968 | packet_get_char(); | |
969 | msg = packet_get_string(NULL); | |
970 | debug("Remote: %.900s", msg); | |
971 | xfree(msg); | |
972 | msg = packet_get_string(NULL); | |
973 | xfree(msg); | |
974 | break; | |
975 | case SSH2_MSG_DISCONNECT: | |
976 | reason = packet_get_int(); | |
977 | msg = packet_get_string(NULL); | |
7c49df64 | 978 | log("Received disconnect from %s: %d: %.400s", get_remote_ipaddr(), |
979 | reason, msg); | |
7e7327a1 | 980 | xfree(msg); |
981 | fatal_cleanup(); | |
982 | break; | |
983 | default: | |
984 | return type; | |
985 | break; | |
2b87da3b | 986 | } |
7e7327a1 | 987 | } else { |
988 | switch(type) { | |
989 | case SSH_MSG_IGNORE: | |
990 | break; | |
991 | case SSH_MSG_DEBUG: | |
992 | msg = packet_get_string(NULL); | |
993 | debug("Remote: %.900s", msg); | |
994 | xfree(msg); | |
995 | break; | |
996 | case SSH_MSG_DISCONNECT: | |
997 | msg = packet_get_string(NULL); | |
7c49df64 | 998 | log("Received disconnect from %s: %.400s", get_remote_ipaddr(), |
999 | msg); | |
7e7327a1 | 1000 | fatal_cleanup(); |
1001 | xfree(msg); | |
1002 | break; | |
1003 | default: | |
1004 | if (type != 0) | |
1005 | DBG(debug("received packet type %d", type)); | |
1006 | return type; | |
1007 | break; | |
2b87da3b | 1008 | } |
7e7327a1 | 1009 | } |
1010 | } | |
1011 | } | |
1012 | ||
aa3378df | 1013 | /* |
1014 | * Buffers the given amount of input characters. This is intended to be used | |
1015 | * together with packet_read_poll. | |
1016 | */ | |
8efc0c15 | 1017 | |
1018 | void | |
1e3b8b07 | 1019 | packet_process_incoming(const char *buf, u_int len) |
8efc0c15 | 1020 | { |
5260325f | 1021 | buffer_append(&input, buf, len); |
8efc0c15 | 1022 | } |
1023 | ||
1024 | /* Returns a character from the packet. */ | |
1025 | ||
1e3b8b07 | 1026 | u_int |
8efc0c15 | 1027 | packet_get_char() |
1028 | { | |
5260325f | 1029 | char ch; |
1030 | buffer_get(&incoming_packet, &ch, 1); | |
1e3b8b07 | 1031 | return (u_char) ch; |
8efc0c15 | 1032 | } |
1033 | ||
1034 | /* Returns an integer from the packet data. */ | |
1035 | ||
1e3b8b07 | 1036 | u_int |
8efc0c15 | 1037 | packet_get_int() |
1038 | { | |
5260325f | 1039 | return buffer_get_int(&incoming_packet); |
8efc0c15 | 1040 | } |
1041 | ||
aa3378df | 1042 | /* |
1043 | * Returns an arbitrary precision integer from the packet data. The integer | |
1044 | * must have been initialized before this call. | |
1045 | */ | |
8efc0c15 | 1046 | |
1047 | void | |
5260325f | 1048 | packet_get_bignum(BIGNUM * value, int *length_ptr) |
8efc0c15 | 1049 | { |
5260325f | 1050 | *length_ptr = buffer_get_bignum(&incoming_packet, value); |
8efc0c15 | 1051 | } |
1052 | ||
7e7327a1 | 1053 | void |
1054 | packet_get_bignum2(BIGNUM * value, int *length_ptr) | |
1055 | { | |
1056 | *length_ptr = buffer_get_bignum2(&incoming_packet, value); | |
1057 | } | |
1058 | ||
1059 | char * | |
1060 | packet_get_raw(int *length_ptr) | |
1061 | { | |
1062 | int bytes = buffer_len(&incoming_packet); | |
1063 | if (length_ptr != NULL) | |
1064 | *length_ptr = bytes; | |
1065 | return buffer_ptr(&incoming_packet); | |
1066 | } | |
1067 | ||
6ae2364d | 1068 | int |
1069 | packet_remaining(void) | |
1070 | { | |
1071 | return buffer_len(&incoming_packet); | |
1072 | } | |
1073 | ||
aa3378df | 1074 | /* |
1075 | * Returns a string from the packet data. The string is allocated using | |
1076 | * xmalloc; it is the responsibility of the calling program to free it when | |
1077 | * no longer needed. The length_ptr argument may be NULL, or point to an | |
1078 | * integer into which the length of the string is stored. | |
1079 | */ | |
8efc0c15 | 1080 | |
aa3378df | 1081 | char * |
1e3b8b07 | 1082 | packet_get_string(u_int *length_ptr) |
8efc0c15 | 1083 | { |
5260325f | 1084 | return buffer_get_string(&incoming_packet, length_ptr); |
8efc0c15 | 1085 | } |
1086 | ||
aa3378df | 1087 | /* |
1088 | * Sends a diagnostic message from the server to the client. This message | |
1089 | * can be sent at any time (but not while constructing another message). The | |
1090 | * message is printed immediately, but only if the client is being executed | |
1091 | * in verbose mode. These messages are primarily intended to ease debugging | |
1092 | * authentication problems. The length of the formatted message must not | |
1093 | * exceed 1024 bytes. This will automatically call packet_write_wait. | |
1094 | */ | |
8efc0c15 | 1095 | |
1096 | void | |
5260325f | 1097 | packet_send_debug(const char *fmt,...) |
8efc0c15 | 1098 | { |
5260325f | 1099 | char buf[1024]; |
1100 | va_list args; | |
1101 | ||
f72fc97f | 1102 | if (compat20 && (datafellows & SSH_BUG_DEBUG)) |
1103 | return; | |
1104 | ||
5260325f | 1105 | va_start(args, fmt); |
1106 | vsnprintf(buf, sizeof(buf), fmt, args); | |
1107 | va_end(args); | |
1108 | ||
c4bc58eb | 1109 | if (compat20) { |
1110 | packet_start(SSH2_MSG_DEBUG); | |
1111 | packet_put_char(0); /* bool: always display */ | |
1112 | packet_put_cstring(buf); | |
1113 | packet_put_cstring(""); | |
1114 | } else { | |
1115 | packet_start(SSH_MSG_DEBUG); | |
1116 | packet_put_cstring(buf); | |
1117 | } | |
5260325f | 1118 | packet_send(); |
1119 | packet_write_wait(); | |
8efc0c15 | 1120 | } |
1121 | ||
aa3378df | 1122 | /* |
1123 | * Logs the error plus constructs and sends a disconnect packet, closes the | |
1124 | * connection, and exits. This function never returns. The error message | |
1125 | * should not contain a newline. The length of the formatted message must | |
1126 | * not exceed 1024 bytes. | |
1127 | */ | |
8efc0c15 | 1128 | |
1129 | void | |
5260325f | 1130 | packet_disconnect(const char *fmt,...) |
1131 | { | |
1132 | char buf[1024]; | |
1133 | va_list args; | |
1134 | static int disconnecting = 0; | |
1135 | if (disconnecting) /* Guard against recursive invocations. */ | |
1136 | fatal("packet_disconnect called recursively."); | |
1137 | disconnecting = 1; | |
1138 | ||
aa3378df | 1139 | /* |
1140 | * Format the message. Note that the caller must make sure the | |
1141 | * message is of limited size. | |
1142 | */ | |
5260325f | 1143 | va_start(args, fmt); |
1144 | vsnprintf(buf, sizeof(buf), fmt, args); | |
1145 | va_end(args); | |
1146 | ||
1147 | /* Send the disconnect message to the other side, and wait for it to get sent. */ | |
7e7327a1 | 1148 | if (compat20) { |
1149 | packet_start(SSH2_MSG_DISCONNECT); | |
1150 | packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR); | |
1151 | packet_put_cstring(buf); | |
1152 | packet_put_cstring(""); | |
1153 | } else { | |
1154 | packet_start(SSH_MSG_DISCONNECT); | |
1155 | packet_put_string(buf, strlen(buf)); | |
1156 | } | |
5260325f | 1157 | packet_send(); |
1158 | packet_write_wait(); | |
1159 | ||
1160 | /* Stop listening for connections. */ | |
1161 | channel_stop_listening(); | |
1162 | ||
1163 | /* Close the connection. */ | |
1164 | packet_close(); | |
1165 | ||
1166 | /* Display the error locally and exit. */ | |
57112b5a | 1167 | log("Disconnecting: %.100s", buf); |
1168 | fatal_cleanup(); | |
8efc0c15 | 1169 | } |
1170 | ||
aa3378df | 1171 | /* Checks if there is any buffered output, and tries to write some of the output. */ |
8efc0c15 | 1172 | |
1173 | void | |
1174 | packet_write_poll() | |
1175 | { | |
5260325f | 1176 | int len = buffer_len(&output); |
1177 | if (len > 0) { | |
1178 | len = write(connection_out, buffer_ptr(&output), len); | |
1179 | if (len <= 0) { | |
1180 | if (errno == EAGAIN) | |
1181 | return; | |
1182 | else | |
1183 | fatal("Write failed: %.100s", strerror(errno)); | |
1184 | } | |
1185 | buffer_consume(&output, len); | |
1186 | } | |
8efc0c15 | 1187 | } |
1188 | ||
aa3378df | 1189 | /* |
1190 | * Calls packet_write_poll repeatedly until all pending output data has been | |
1191 | * written. | |
1192 | */ | |
8efc0c15 | 1193 | |
1194 | void | |
1195 | packet_write_wait() | |
1196 | { | |
5260325f | 1197 | packet_write_poll(); |
1198 | while (packet_have_data_to_write()) { | |
1199 | fd_set set; | |
fd193ca4 | 1200 | |
5260325f | 1201 | FD_ZERO(&set); |
1202 | FD_SET(connection_out, &set); | |
fd193ca4 | 1203 | while (select(connection_out + 1, NULL, &set, NULL, NULL) == -1 && |
1204 | (errno == EAGAIN || errno == EINTR)) | |
1205 | ; | |
5260325f | 1206 | packet_write_poll(); |
1207 | } | |
8efc0c15 | 1208 | } |
1209 | ||
1210 | /* Returns true if there is buffered data to write to the connection. */ | |
1211 | ||
1212 | int | |
1213 | packet_have_data_to_write() | |
1214 | { | |
5260325f | 1215 | return buffer_len(&output) != 0; |
8efc0c15 | 1216 | } |
1217 | ||
1218 | /* Returns true if there is not too much data to write to the connection. */ | |
1219 | ||
1220 | int | |
1221 | packet_not_very_much_data_to_write() | |
1222 | { | |
5260325f | 1223 | if (interactive_mode) |
1224 | return buffer_len(&output) < 16384; | |
1225 | else | |
1226 | return buffer_len(&output) < 128 * 1024; | |
8efc0c15 | 1227 | } |
1228 | ||
1229 | /* Informs that the current session is interactive. Sets IP flags for that. */ | |
1230 | ||
1231 | void | |
b5c334cc | 1232 | packet_set_interactive(int interactive) |
8efc0c15 | 1233 | { |
b5c334cc | 1234 | static int called = 0; |
64e0e67e | 1235 | #if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) |
b5c334cc | 1236 | int lowdelay = IPTOS_LOWDELAY; |
1237 | int throughput = IPTOS_THROUGHPUT; | |
64e0e67e | 1238 | #endif |
5260325f | 1239 | int on = 1; |
1240 | ||
b5c334cc | 1241 | if (called) |
1242 | return; | |
1243 | called = 1; | |
1244 | ||
5260325f | 1245 | /* Record that we are in interactive mode. */ |
1246 | interactive_mode = interactive; | |
1247 | ||
48e671d5 | 1248 | /* Only set socket options if using a socket. */ |
1249 | if (!packet_connection_is_on_socket()) | |
5260325f | 1250 | return; |
48e671d5 | 1251 | /* |
f546c780 | 1252 | * IPTOS_LOWDELAY and IPTOS_THROUGHPUT are IPv4 only |
48e671d5 | 1253 | */ |
5260325f | 1254 | if (interactive) { |
aa3378df | 1255 | /* |
1256 | * Set IP options for an interactive connection. Use | |
1257 | * IPTOS_LOWDELAY and TCP_NODELAY. | |
1258 | */ | |
132dd316 | 1259 | #if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) |
f546c780 | 1260 | if (packet_connection_is_ipv4()) { |
0e3c1f95 | 1261 | if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, |
f546c780 | 1262 | (void *) &lowdelay, sizeof(lowdelay)) < 0) |
0e3c1f95 | 1263 | error("setsockopt IPTOS_LOWDELAY: %.100s", |
f546c780 | 1264 | strerror(errno)); |
1265 | } | |
c04f75f1 | 1266 | #endif |
5260325f | 1267 | if (setsockopt(connection_in, IPPROTO_TCP, TCP_NODELAY, (void *) &on, |
48e671d5 | 1268 | sizeof(on)) < 0) |
5260325f | 1269 | error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); |
f546c780 | 1270 | } else if (packet_connection_is_ipv4()) { |
aa3378df | 1271 | /* |
1272 | * Set IP options for a non-interactive connection. Use | |
1273 | * IPTOS_THROUGHPUT. | |
1274 | */ | |
132dd316 | 1275 | #if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) |
5260325f | 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 | } |