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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" | |
42f11eb2 | 40 | RCSID("$OpenBSD: packet.c,v 1.46 2001/01/21 19:05:53 markus 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 | ||
35484284 | 57 | #include <openssl/bn.h> |
58 | #include <openssl/dh.h> | |
59 | #include <openssl/hmac.h> | |
7e7327a1 | 60 | #include "buffer.h" |
94ec8c6b | 61 | #include "cipher.h" |
7e7327a1 | 62 | #include "kex.h" |
63 | #include "hmac.h" | |
42f11eb2 | 64 | #include "log.h" |
65 | #include "canohost.h" | |
7e7327a1 | 66 | |
67 | #ifdef PACKET_DEBUG | |
68 | #define DBG(x) x | |
69 | #else | |
70 | #define DBG(x) | |
71 | #endif | |
72 | ||
aa3378df | 73 | /* |
74 | * This variable contains the file descriptors used for communicating with | |
75 | * the other side. connection_in is used for reading; connection_out for | |
76 | * writing. These can be the same descriptor, in which case it is assumed to | |
77 | * be a socket. | |
78 | */ | |
8efc0c15 | 79 | static int connection_in = -1; |
80 | static int connection_out = -1; | |
81 | ||
aa3378df | 82 | /* |
83 | * Cipher type. This value is only used to determine whether to pad the | |
84 | * packets with zeroes or random data. | |
85 | */ | |
8efc0c15 | 86 | static int cipher_type = SSH_CIPHER_NONE; |
87 | ||
88 | /* Protocol flags for the remote side. */ | |
1e3b8b07 | 89 | static u_int remote_protocol_flags = 0; |
8efc0c15 | 90 | |
91 | /* Encryption context for receiving data. This is only used for decryption. */ | |
92 | static CipherContext receive_context; | |
5260325f | 93 | |
94 | /* Encryption context for sending data. This is only used for encryption. */ | |
8efc0c15 | 95 | static CipherContext send_context; |
96 | ||
97 | /* Buffer for raw input data from the socket. */ | |
98 | static Buffer input; | |
99 | ||
100 | /* Buffer for raw output data going to the socket. */ | |
101 | static Buffer output; | |
102 | ||
103 | /* Buffer for the partial outgoing packet being constructed. */ | |
104 | static Buffer outgoing_packet; | |
105 | ||
106 | /* Buffer for the incoming packet currently being processed. */ | |
107 | static Buffer incoming_packet; | |
108 | ||
109 | /* Scratch buffer for packet compression/decompression. */ | |
110 | static Buffer compression_buffer; | |
111 | ||
112 | /* Flag indicating whether packet compression/decompression is enabled. */ | |
113 | static int packet_compression = 0; | |
114 | ||
9d6b7add | 115 | /* default maximum packet size */ |
116 | int max_packet_size = 32768; | |
117 | ||
8efc0c15 | 118 | /* Flag indicating whether this module has been initialized. */ |
119 | static int initialized = 0; | |
120 | ||
121 | /* Set to true if the connection is interactive. */ | |
122 | static int interactive_mode = 0; | |
123 | ||
7e7327a1 | 124 | /* True if SSH2 packet format is used */ |
125 | int use_ssh2_packet_format = 0; | |
126 | ||
127 | /* Session key information for Encryption and MAC */ | |
128 | Kex *kex = NULL; | |
129 | ||
130 | void | |
131 | packet_set_kex(Kex *k) | |
132 | { | |
133 | if( k->mac[MODE_IN ].key == NULL || | |
134 | k->enc[MODE_IN ].key == NULL || | |
135 | k->enc[MODE_IN ].iv == NULL || | |
136 | k->mac[MODE_OUT].key == NULL || | |
137 | k->enc[MODE_OUT].key == NULL || | |
138 | k->enc[MODE_OUT].iv == NULL) | |
139 | fatal("bad KEX"); | |
140 | kex = k; | |
141 | } | |
142 | void | |
143 | clear_enc_keys(Enc *enc, int len) | |
144 | { | |
145 | memset(enc->iv, 0, len); | |
146 | memset(enc->key, 0, len); | |
147 | xfree(enc->iv); | |
148 | xfree(enc->key); | |
149 | enc->iv = NULL; | |
150 | enc->key = NULL; | |
151 | } | |
152 | void | |
153 | packet_set_ssh2_format(void) | |
154 | { | |
3189621b | 155 | DBG(debug("use_ssh2_packet_format")); |
7e7327a1 | 156 | use_ssh2_packet_format = 1; |
157 | } | |
158 | ||
aa3378df | 159 | /* |
160 | * Sets the descriptors used for communication. Disables encryption until | |
161 | * packet_set_encryption_key is called. | |
162 | */ | |
8efc0c15 | 163 | void |
164 | packet_set_connection(int fd_in, int fd_out) | |
165 | { | |
94ec8c6b | 166 | Cipher *none = cipher_by_name("none"); |
167 | if (none == NULL) | |
168 | fatal("packet_set_connection: cannot load cipher 'none'"); | |
5260325f | 169 | connection_in = fd_in; |
170 | connection_out = fd_out; | |
171 | cipher_type = SSH_CIPHER_NONE; | |
1e3b8b07 | 172 | cipher_init(&send_context, none, (u_char *) "", 0, NULL, 0); |
173 | cipher_init(&receive_context, none, (u_char *) "", 0, NULL, 0); | |
5260325f | 174 | if (!initialized) { |
175 | initialized = 1; | |
176 | buffer_init(&input); | |
177 | buffer_init(&output); | |
178 | buffer_init(&outgoing_packet); | |
179 | buffer_init(&incoming_packet); | |
180 | } | |
181 | /* Kludge: arrange the close function to be called from fatal(). */ | |
182 | fatal_add_cleanup((void (*) (void *)) packet_close, NULL); | |
8efc0c15 | 183 | } |
184 | ||
48e671d5 | 185 | /* Returns 1 if remote host is connected via socket, 0 if not. */ |
186 | ||
187 | int | |
188 | packet_connection_is_on_socket() | |
189 | { | |
190 | struct sockaddr_storage from, to; | |
191 | socklen_t fromlen, tolen; | |
192 | ||
193 | /* filedescriptors in and out are the same, so it's a socket */ | |
194 | if (connection_in == connection_out) | |
195 | return 1; | |
196 | fromlen = sizeof(from); | |
197 | memset(&from, 0, sizeof(from)); | |
9bc5ddfe | 198 | if (getpeername(connection_in, (struct sockaddr *)&from, &fromlen) < 0) |
48e671d5 | 199 | return 0; |
200 | tolen = sizeof(to); | |
201 | memset(&to, 0, sizeof(to)); | |
9bc5ddfe | 202 | if (getpeername(connection_out, (struct sockaddr *)&to, &tolen) < 0) |
48e671d5 | 203 | return 0; |
204 | if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0) | |
205 | return 0; | |
206 | if (from.ss_family != AF_INET && from.ss_family != AF_INET6) | |
207 | return 0; | |
208 | return 1; | |
209 | } | |
210 | ||
211 | /* returns 1 if connection is via ipv4 */ | |
212 | ||
213 | int | |
214 | packet_connection_is_ipv4() | |
215 | { | |
216 | struct sockaddr_storage to; | |
d45317d8 | 217 | socklen_t tolen = sizeof(to); |
48e671d5 | 218 | |
219 | memset(&to, 0, sizeof(to)); | |
220 | if (getsockname(connection_out, (struct sockaddr *)&to, &tolen) < 0) | |
221 | return 0; | |
222 | if (to.ss_family != AF_INET) | |
223 | return 0; | |
224 | return 1; | |
225 | } | |
226 | ||
8efc0c15 | 227 | /* Sets the connection into non-blocking mode. */ |
228 | ||
229 | void | |
230 | packet_set_nonblocking() | |
231 | { | |
5260325f | 232 | /* Set the socket into non-blocking mode. */ |
233 | if (fcntl(connection_in, F_SETFL, O_NONBLOCK) < 0) | |
234 | error("fcntl O_NONBLOCK: %.100s", strerror(errno)); | |
8efc0c15 | 235 | |
5260325f | 236 | if (connection_out != connection_in) { |
237 | if (fcntl(connection_out, F_SETFL, O_NONBLOCK) < 0) | |
238 | error("fcntl O_NONBLOCK: %.100s", strerror(errno)); | |
239 | } | |
8efc0c15 | 240 | } |
241 | ||
242 | /* Returns the socket used for reading. */ | |
243 | ||
244 | int | |
245 | packet_get_connection_in() | |
246 | { | |
5260325f | 247 | return connection_in; |
8efc0c15 | 248 | } |
249 | ||
250 | /* Returns the descriptor used for writing. */ | |
251 | ||
252 | int | |
253 | packet_get_connection_out() | |
254 | { | |
5260325f | 255 | return connection_out; |
8efc0c15 | 256 | } |
257 | ||
258 | /* Closes the connection and clears and frees internal data structures. */ | |
259 | ||
260 | void | |
261 | packet_close() | |
262 | { | |
5260325f | 263 | if (!initialized) |
264 | return; | |
265 | initialized = 0; | |
266 | if (connection_in == connection_out) { | |
267 | shutdown(connection_out, SHUT_RDWR); | |
268 | close(connection_out); | |
269 | } else { | |
270 | close(connection_in); | |
271 | close(connection_out); | |
272 | } | |
273 | buffer_free(&input); | |
274 | buffer_free(&output); | |
275 | buffer_free(&outgoing_packet); | |
276 | buffer_free(&incoming_packet); | |
277 | if (packet_compression) { | |
278 | buffer_free(&compression_buffer); | |
279 | buffer_compress_uninit(); | |
280 | } | |
8efc0c15 | 281 | } |
282 | ||
283 | /* Sets remote side protocol flags. */ | |
284 | ||
285 | void | |
1e3b8b07 | 286 | packet_set_protocol_flags(u_int protocol_flags) |
8efc0c15 | 287 | { |
5260325f | 288 | remote_protocol_flags = protocol_flags; |
289 | channel_set_options((protocol_flags & SSH_PROTOFLAG_HOST_IN_FWD_OPEN) != 0); | |
8efc0c15 | 290 | } |
291 | ||
292 | /* Returns the remote protocol flags set earlier by the above function. */ | |
293 | ||
1e3b8b07 | 294 | u_int |
8efc0c15 | 295 | packet_get_protocol_flags() |
296 | { | |
5260325f | 297 | return remote_protocol_flags; |
8efc0c15 | 298 | } |
299 | ||
aa3378df | 300 | /* |
301 | * Starts packet compression from the next packet on in both directions. | |
302 | * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip. | |
303 | */ | |
8efc0c15 | 304 | |
7e7327a1 | 305 | /*** XXXXX todo: kex means re-init */ |
8efc0c15 | 306 | void |
307 | packet_start_compression(int level) | |
308 | { | |
5260325f | 309 | if (packet_compression) |
310 | fatal("Compression already enabled."); | |
311 | packet_compression = 1; | |
312 | buffer_init(&compression_buffer); | |
313 | buffer_compress_init(level); | |
8efc0c15 | 314 | } |
315 | ||
aa3378df | 316 | /* |
317 | * Encrypts the given number of bytes, copying from src to dest. bytes is | |
318 | * known to be a multiple of 8. | |
319 | */ | |
8efc0c15 | 320 | |
321 | void | |
5260325f | 322 | packet_encrypt(CipherContext * cc, void *dest, void *src, |
1e3b8b07 | 323 | u_int bytes) |
8efc0c15 | 324 | { |
5260325f | 325 | cipher_encrypt(cc, dest, src, bytes); |
8efc0c15 | 326 | } |
327 | ||
aa3378df | 328 | /* |
329 | * Decrypts the given number of bytes, copying from src to dest. bytes is | |
330 | * known to be a multiple of 8. | |
331 | */ | |
8efc0c15 | 332 | |
333 | void | |
1e3b8b07 | 334 | packet_decrypt(CipherContext *context, void *dest, void *src, u_int bytes) |
8efc0c15 | 335 | { |
aa3378df | 336 | /* |
337 | * Cryptographic attack detector for ssh - Modifications for packet.c | |
338 | * (C)1998 CORE-SDI, Buenos Aires Argentina Ariel Futoransky(futo@core-sdi.com) | |
339 | */ | |
94ec8c6b | 340 | if (!compat20 && |
341 | context->cipher->number != SSH_CIPHER_NONE && | |
342 | detect_attack(src, bytes, NULL) == DEATTACK_DETECTED) | |
5260325f | 343 | packet_disconnect("crc32 compensation attack: network attack detected"); |
344 | ||
94ec8c6b | 345 | cipher_decrypt(context, dest, src, bytes); |
8efc0c15 | 346 | } |
347 | ||
aa3378df | 348 | /* |
349 | * Causes any further packets to be encrypted using the given key. The same | |
350 | * key is used for both sending and reception. However, both directions are | |
351 | * encrypted independently of each other. | |
352 | */ | |
8efc0c15 | 353 | |
354 | void | |
1e3b8b07 | 355 | packet_set_encryption_key(const u_char *key, u_int keylen, |
94ec8c6b | 356 | int number) |
8efc0c15 | 357 | { |
94ec8c6b | 358 | Cipher *cipher = cipher_by_number(number); |
359 | if (cipher == NULL) | |
360 | fatal("packet_set_encryption_key: unknown cipher number %d", number); | |
7e7327a1 | 361 | if (keylen < 20) |
94ec8c6b | 362 | fatal("packet_set_encryption_key: keylen too small: %d", keylen); |
363 | cipher_init(&receive_context, cipher, key, keylen, NULL, 0); | |
364 | cipher_init(&send_context, cipher, key, keylen, NULL, 0); | |
8efc0c15 | 365 | } |
366 | ||
367 | /* Starts constructing a packet to send. */ | |
368 | ||
369 | void | |
7e7327a1 | 370 | packet_start1(int type) |
8efc0c15 | 371 | { |
5260325f | 372 | char buf[9]; |
8efc0c15 | 373 | |
5260325f | 374 | buffer_clear(&outgoing_packet); |
375 | memset(buf, 0, 8); | |
376 | buf[8] = type; | |
377 | buffer_append(&outgoing_packet, buf, 9); | |
8efc0c15 | 378 | } |
379 | ||
7e7327a1 | 380 | void |
381 | packet_start2(int type) | |
382 | { | |
383 | char buf[4+1+1]; | |
384 | ||
385 | buffer_clear(&outgoing_packet); | |
386 | memset(buf, 0, sizeof buf); | |
387 | /* buf[0..3] = payload_len; */ | |
388 | /* buf[4] = pad_len; */ | |
389 | buf[5] = type & 0xff; | |
390 | buffer_append(&outgoing_packet, buf, sizeof buf); | |
391 | } | |
392 | ||
393 | void | |
394 | packet_start(int type) | |
395 | { | |
396 | DBG(debug("packet_start[%d]",type)); | |
397 | if (use_ssh2_packet_format) | |
398 | packet_start2(type); | |
399 | else | |
400 | packet_start1(type); | |
401 | } | |
402 | ||
8efc0c15 | 403 | /* Appends a character to the packet data. */ |
404 | ||
405 | void | |
406 | packet_put_char(int value) | |
407 | { | |
5260325f | 408 | char ch = value; |
409 | buffer_append(&outgoing_packet, &ch, 1); | |
8efc0c15 | 410 | } |
411 | ||
412 | /* Appends an integer to the packet data. */ | |
413 | ||
414 | void | |
1e3b8b07 | 415 | packet_put_int(u_int value) |
8efc0c15 | 416 | { |
5260325f | 417 | buffer_put_int(&outgoing_packet, value); |
8efc0c15 | 418 | } |
419 | ||
420 | /* Appends a string to packet data. */ | |
421 | ||
422 | void | |
1e3b8b07 | 423 | packet_put_string(const char *buf, u_int len) |
8efc0c15 | 424 | { |
5260325f | 425 | buffer_put_string(&outgoing_packet, buf, len); |
8efc0c15 | 426 | } |
7e7327a1 | 427 | void |
428 | packet_put_cstring(const char *str) | |
429 | { | |
430 | buffer_put_string(&outgoing_packet, str, strlen(str)); | |
431 | } | |
432 | ||
433 | void | |
1e3b8b07 | 434 | packet_put_raw(const char *buf, u_int len) |
7e7327a1 | 435 | { |
436 | buffer_append(&outgoing_packet, buf, len); | |
437 | } | |
438 | ||
8efc0c15 | 439 | |
440 | /* Appends an arbitrary precision integer to packet data. */ | |
441 | ||
442 | void | |
5260325f | 443 | packet_put_bignum(BIGNUM * value) |
8efc0c15 | 444 | { |
5260325f | 445 | buffer_put_bignum(&outgoing_packet, value); |
8efc0c15 | 446 | } |
7e7327a1 | 447 | void |
448 | packet_put_bignum2(BIGNUM * value) | |
449 | { | |
450 | buffer_put_bignum2(&outgoing_packet, value); | |
451 | } | |
8efc0c15 | 452 | |
aa3378df | 453 | /* |
454 | * Finalizes and sends the packet. If the encryption key has been set, | |
455 | * encrypts the packet before sending. | |
456 | */ | |
5260325f | 457 | |
8efc0c15 | 458 | void |
7e7327a1 | 459 | packet_send1() |
8efc0c15 | 460 | { |
5260325f | 461 | char buf[8], *cp; |
462 | int i, padding, len; | |
1e3b8b07 | 463 | u_int checksum; |
5260325f | 464 | u_int32_t rand = 0; |
465 | ||
aa3378df | 466 | /* |
467 | * If using packet compression, compress the payload of the outgoing | |
468 | * packet. | |
469 | */ | |
5260325f | 470 | if (packet_compression) { |
471 | buffer_clear(&compression_buffer); | |
472 | /* Skip padding. */ | |
473 | buffer_consume(&outgoing_packet, 8); | |
474 | /* padding */ | |
475 | buffer_append(&compression_buffer, "\0\0\0\0\0\0\0\0", 8); | |
476 | buffer_compress(&outgoing_packet, &compression_buffer); | |
477 | buffer_clear(&outgoing_packet); | |
478 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), | |
479 | buffer_len(&compression_buffer)); | |
480 | } | |
481 | /* Compute packet length without padding (add checksum, remove padding). */ | |
482 | len = buffer_len(&outgoing_packet) + 4 - 8; | |
483 | ||
1d1ffb87 | 484 | /* Insert padding. Initialized to zero in packet_start1() */ |
5260325f | 485 | padding = 8 - len % 8; |
486 | if (cipher_type != SSH_CIPHER_NONE) { | |
487 | cp = buffer_ptr(&outgoing_packet); | |
488 | for (i = 0; i < padding; i++) { | |
489 | if (i % 4 == 0) | |
490 | rand = arc4random(); | |
491 | cp[7 - i] = rand & 0xff; | |
492 | rand >>= 8; | |
493 | } | |
494 | } | |
495 | buffer_consume(&outgoing_packet, 8 - padding); | |
496 | ||
497 | /* Add check bytes. */ | |
1e3b8b07 | 498 | checksum = ssh_crc32((u_char *) buffer_ptr(&outgoing_packet), |
2e73a022 | 499 | buffer_len(&outgoing_packet)); |
5260325f | 500 | PUT_32BIT(buf, checksum); |
501 | buffer_append(&outgoing_packet, buf, 4); | |
8efc0c15 | 502 | |
503 | #ifdef PACKET_DEBUG | |
5260325f | 504 | fprintf(stderr, "packet_send plain: "); |
505 | buffer_dump(&outgoing_packet); | |
8efc0c15 | 506 | #endif |
507 | ||
5260325f | 508 | /* Append to output. */ |
509 | PUT_32BIT(buf, len); | |
510 | buffer_append(&output, buf, 4); | |
511 | buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); | |
512 | packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), | |
513 | buffer_len(&outgoing_packet)); | |
514 | ||
8efc0c15 | 515 | #ifdef PACKET_DEBUG |
5260325f | 516 | fprintf(stderr, "encrypted: "); |
517 | buffer_dump(&output); | |
8efc0c15 | 518 | #endif |
519 | ||
5260325f | 520 | buffer_clear(&outgoing_packet); |
8efc0c15 | 521 | |
aa3378df | 522 | /* |
523 | * Note that the packet is now only buffered in output. It won\'t be | |
524 | * actually sent until packet_write_wait or packet_write_poll is | |
525 | * called. | |
526 | */ | |
8efc0c15 | 527 | } |
528 | ||
7e7327a1 | 529 | /* |
530 | * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue) | |
531 | */ | |
532 | void | |
533 | packet_send2() | |
534 | { | |
1e3b8b07 | 535 | u_char *macbuf = NULL; |
7e7327a1 | 536 | char *cp; |
1e3b8b07 | 537 | u_int packet_length = 0; |
538 | u_int i, padlen, len; | |
7e7327a1 | 539 | u_int32_t rand = 0; |
1e3b8b07 | 540 | static u_int seqnr = 0; |
7e7327a1 | 541 | int type; |
542 | Enc *enc = NULL; | |
543 | Mac *mac = NULL; | |
544 | Comp *comp = NULL; | |
545 | int block_size; | |
546 | ||
547 | if (kex != NULL) { | |
548 | enc = &kex->enc[MODE_OUT]; | |
549 | mac = &kex->mac[MODE_OUT]; | |
550 | comp = &kex->comp[MODE_OUT]; | |
551 | } | |
94ec8c6b | 552 | block_size = enc ? enc->cipher->block_size : 8; |
7e7327a1 | 553 | |
554 | cp = buffer_ptr(&outgoing_packet); | |
555 | type = cp[5] & 0xff; | |
556 | ||
557 | #ifdef PACKET_DEBUG | |
558 | fprintf(stderr, "plain: "); | |
559 | buffer_dump(&outgoing_packet); | |
560 | #endif | |
561 | ||
562 | if (comp && comp->enabled) { | |
563 | len = buffer_len(&outgoing_packet); | |
564 | /* skip header, compress only payload */ | |
565 | buffer_consume(&outgoing_packet, 5); | |
566 | buffer_clear(&compression_buffer); | |
567 | buffer_compress(&outgoing_packet, &compression_buffer); | |
568 | buffer_clear(&outgoing_packet); | |
569 | buffer_append(&outgoing_packet, "\0\0\0\0\0", 5); | |
570 | buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer), | |
571 | buffer_len(&compression_buffer)); | |
572 | DBG(debug("compression: raw %d compressed %d", len, | |
573 | buffer_len(&outgoing_packet))); | |
574 | } | |
575 | ||
576 | /* sizeof (packet_len + pad_len + payload) */ | |
577 | len = buffer_len(&outgoing_packet); | |
578 | ||
579 | /* | |
580 | * calc size of padding, alloc space, get random data, | |
581 | * minimum padding is 4 bytes | |
582 | */ | |
583 | padlen = block_size - (len % block_size); | |
584 | if (padlen < 4) | |
585 | padlen += block_size; | |
586 | buffer_append_space(&outgoing_packet, &cp, padlen); | |
94ec8c6b | 587 | if (enc && enc->cipher->number != SSH_CIPHER_NONE) { |
1d1ffb87 | 588 | /* random padding */ |
7e7327a1 | 589 | for (i = 0; i < padlen; i++) { |
590 | if (i % 4 == 0) | |
591 | rand = arc4random(); | |
592 | cp[i] = rand & 0xff; | |
593 | rand <<= 8; | |
594 | } | |
1d1ffb87 | 595 | } else { |
596 | /* clear padding */ | |
597 | memset(cp, 0, padlen); | |
7e7327a1 | 598 | } |
599 | /* packet_length includes payload, padding and padding length field */ | |
600 | packet_length = buffer_len(&outgoing_packet) - 4; | |
601 | cp = buffer_ptr(&outgoing_packet); | |
602 | PUT_32BIT(cp, packet_length); | |
603 | cp[4] = padlen & 0xff; | |
604 | DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen)); | |
605 | ||
606 | /* compute MAC over seqnr and packet(length fields, payload, padding) */ | |
607 | if (mac && mac->enabled) { | |
608 | macbuf = hmac( mac->md, seqnr, | |
1e3b8b07 | 609 | (u_char *) buffer_ptr(&outgoing_packet), |
7e7327a1 | 610 | buffer_len(&outgoing_packet), |
611 | mac->key, mac->key_len | |
612 | ); | |
94ec8c6b | 613 | DBG(debug("done calc MAC out #%d", seqnr)); |
7e7327a1 | 614 | } |
615 | /* encrypt packet and append to output buffer. */ | |
616 | buffer_append_space(&output, &cp, buffer_len(&outgoing_packet)); | |
617 | packet_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet), | |
618 | buffer_len(&outgoing_packet)); | |
619 | /* append unencrypted MAC */ | |
620 | if (mac && mac->enabled) | |
621 | buffer_append(&output, (char *)macbuf, mac->mac_len); | |
622 | #ifdef PACKET_DEBUG | |
623 | fprintf(stderr, "encrypted: "); | |
624 | buffer_dump(&output); | |
625 | #endif | |
6ae2364d | 626 | /* increment sequence number for outgoing packets */ |
627 | if (++seqnr == 0) | |
628 | log("outgoing seqnr wraps around"); | |
7e7327a1 | 629 | buffer_clear(&outgoing_packet); |
630 | ||
631 | if (type == SSH2_MSG_NEWKEYS) { | |
632 | if (kex==NULL || mac==NULL || enc==NULL || comp==NULL) | |
633 | fatal("packet_send2: no KEX"); | |
634 | if (mac->md != NULL) | |
635 | mac->enabled = 1; | |
94ec8c6b | 636 | DBG(debug("cipher_init send_context")); |
637 | cipher_init(&send_context, enc->cipher, | |
638 | enc->key, enc->cipher->key_len, | |
639 | enc->iv, enc->cipher->block_size); | |
7e7327a1 | 640 | clear_enc_keys(enc, kex->we_need); |
641 | if (comp->type != 0 && comp->enabled == 0) { | |
642 | comp->enabled = 1; | |
643 | if (! packet_compression) | |
644 | packet_start_compression(6); | |
645 | } | |
646 | } | |
647 | } | |
648 | ||
649 | void | |
650 | packet_send() | |
651 | { | |
652 | if (use_ssh2_packet_format) | |
653 | packet_send2(); | |
654 | else | |
655 | packet_send1(); | |
656 | DBG(debug("packet_send done")); | |
657 | } | |
658 | ||
aa3378df | 659 | /* |
660 | * Waits until a packet has been received, and returns its type. Note that | |
661 | * no other data is processed until this returns, so this function should not | |
662 | * be used during the interactive session. | |
663 | */ | |
8efc0c15 | 664 | |
665 | int | |
666 | packet_read(int *payload_len_ptr) | |
667 | { | |
5260325f | 668 | int type, len; |
669 | fd_set set; | |
670 | char buf[8192]; | |
7e7327a1 | 671 | DBG(debug("packet_read()")); |
5260325f | 672 | |
673 | /* Since we are blocking, ensure that all written packets have been sent. */ | |
674 | packet_write_wait(); | |
675 | ||
676 | /* Stay in the loop until we have received a complete packet. */ | |
677 | for (;;) { | |
678 | /* Try to read a packet from the buffer. */ | |
679 | type = packet_read_poll(payload_len_ptr); | |
1d1ffb87 | 680 | if (!use_ssh2_packet_format && ( |
681 | type == SSH_SMSG_SUCCESS | |
5260325f | 682 | || type == SSH_SMSG_FAILURE |
683 | || type == SSH_CMSG_EOF | |
1d1ffb87 | 684 | || type == SSH_CMSG_EXIT_CONFIRMATION)) |
5260325f | 685 | packet_integrity_check(*payload_len_ptr, 0, type); |
686 | /* If we got a packet, return it. */ | |
687 | if (type != SSH_MSG_NONE) | |
688 | return type; | |
aa3378df | 689 | /* |
690 | * Otherwise, wait for some data to arrive, add it to the | |
691 | * buffer, and try again. | |
692 | */ | |
5260325f | 693 | FD_ZERO(&set); |
694 | FD_SET(connection_in, &set); | |
aa3378df | 695 | |
5260325f | 696 | /* Wait for some data to arrive. */ |
697 | select(connection_in + 1, &set, NULL, NULL, NULL); | |
aa3378df | 698 | |
5260325f | 699 | /* Read data from the socket. */ |
700 | len = read(connection_in, buf, sizeof(buf)); | |
89cafde6 | 701 | if (len == 0) { |
702 | log("Connection closed by %.200s", get_remote_ipaddr()); | |
703 | fatal_cleanup(); | |
704 | } | |
5260325f | 705 | if (len < 0) |
706 | fatal("Read from socket failed: %.100s", strerror(errno)); | |
707 | /* Append it to the buffer. */ | |
708 | packet_process_incoming(buf, len); | |
709 | } | |
710 | /* NOTREACHED */ | |
8efc0c15 | 711 | } |
712 | ||
aa3378df | 713 | /* |
714 | * Waits until a packet has been received, verifies that its type matches | |
715 | * that given, and gives a fatal error and exits if there is a mismatch. | |
716 | */ | |
8efc0c15 | 717 | |
718 | void | |
719 | packet_read_expect(int *payload_len_ptr, int expected_type) | |
720 | { | |
5260325f | 721 | int type; |
8efc0c15 | 722 | |
5260325f | 723 | type = packet_read(payload_len_ptr); |
724 | if (type != expected_type) | |
725 | packet_disconnect("Protocol error: expected packet type %d, got %d", | |
7e7327a1 | 726 | expected_type, type); |
8efc0c15 | 727 | } |
728 | ||
729 | /* Checks if a full packet is available in the data received so far via | |
5260325f | 730 | * packet_process_incoming. If so, reads the packet; otherwise returns |
731 | * SSH_MSG_NONE. This does not wait for data from the connection. | |
732 | * | |
733 | * SSH_MSG_DISCONNECT is handled specially here. Also, | |
734 | * SSH_MSG_IGNORE messages are skipped by this function and are never returned | |
735 | * to higher levels. | |
736 | * | |
737 | * The returned payload_len does include space consumed by: | |
738 | * Packet length | |
739 | * Padding | |
740 | * Packet type | |
741 | * Check bytes | |
742 | */ | |
8efc0c15 | 743 | |
744 | int | |
7e7327a1 | 745 | packet_read_poll1(int *payload_len_ptr) |
8efc0c15 | 746 | { |
1e3b8b07 | 747 | u_int len, padded_len; |
748 | u_char *ucp; | |
7e7327a1 | 749 | char buf[8], *cp; |
1e3b8b07 | 750 | u_int checksum, stored_checksum; |
5260325f | 751 | |
5260325f | 752 | /* Check if input size is less than minimum packet size. */ |
753 | if (buffer_len(&input) < 4 + 8) | |
754 | return SSH_MSG_NONE; | |
755 | /* Get length of incoming packet. */ | |
1e3b8b07 | 756 | ucp = (u_char *) buffer_ptr(&input); |
5260325f | 757 | len = GET_32BIT(ucp); |
758 | if (len < 1 + 2 + 2 || len > 256 * 1024) | |
759 | packet_disconnect("Bad packet length %d.", len); | |
760 | padded_len = (len + 8) & ~7; | |
761 | ||
762 | /* Check if the packet has been entirely received. */ | |
763 | if (buffer_len(&input) < 4 + padded_len) | |
764 | return SSH_MSG_NONE; | |
765 | ||
766 | /* The entire packet is in buffer. */ | |
767 | ||
768 | /* Consume packet length. */ | |
769 | buffer_consume(&input, 4); | |
770 | ||
771 | /* Copy data to incoming_packet. */ | |
772 | buffer_clear(&incoming_packet); | |
773 | buffer_append_space(&incoming_packet, &cp, padded_len); | |
774 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len); | |
775 | buffer_consume(&input, padded_len); | |
8efc0c15 | 776 | |
777 | #ifdef PACKET_DEBUG | |
5260325f | 778 | fprintf(stderr, "read_poll plain: "); |
779 | buffer_dump(&incoming_packet); | |
8efc0c15 | 780 | #endif |
5260325f | 781 | |
782 | /* Compute packet checksum. */ | |
1e3b8b07 | 783 | checksum = ssh_crc32((u_char *) buffer_ptr(&incoming_packet), |
7e7327a1 | 784 | buffer_len(&incoming_packet) - 4); |
5260325f | 785 | |
786 | /* Skip padding. */ | |
787 | buffer_consume(&incoming_packet, 8 - len % 8); | |
788 | ||
789 | /* Test check bytes. */ | |
790 | ||
791 | if (len != buffer_len(&incoming_packet)) | |
792 | packet_disconnect("packet_read_poll: len %d != buffer_len %d.", | |
7e7327a1 | 793 | len, buffer_len(&incoming_packet)); |
5260325f | 794 | |
1e3b8b07 | 795 | ucp = (u_char *) buffer_ptr(&incoming_packet) + len - 4; |
5260325f | 796 | stored_checksum = GET_32BIT(ucp); |
797 | if (checksum != stored_checksum) | |
798 | packet_disconnect("Corrupted check bytes on input."); | |
799 | buffer_consume_end(&incoming_packet, 4); | |
800 | ||
801 | /* If using packet compression, decompress the packet. */ | |
802 | if (packet_compression) { | |
803 | buffer_clear(&compression_buffer); | |
804 | buffer_uncompress(&incoming_packet, &compression_buffer); | |
805 | buffer_clear(&incoming_packet); | |
806 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), | |
7e7327a1 | 807 | buffer_len(&compression_buffer)); |
5260325f | 808 | } |
809 | /* Get packet type. */ | |
810 | buffer_get(&incoming_packet, &buf[0], 1); | |
811 | ||
812 | /* Return length of payload (without type field). */ | |
813 | *payload_len_ptr = buffer_len(&incoming_packet); | |
814 | ||
5260325f | 815 | /* Return type. */ |
1e3b8b07 | 816 | return (u_char) buf[0]; |
5260325f | 817 | } |
818 | ||
7e7327a1 | 819 | int |
820 | packet_read_poll2(int *payload_len_ptr) | |
821 | { | |
1e3b8b07 | 822 | u_int padlen, need; |
823 | u_char buf[8], *macbuf; | |
824 | u_char *ucp; | |
7e7327a1 | 825 | char *cp; |
1e3b8b07 | 826 | static u_int packet_length = 0; |
827 | static u_int seqnr = 0; | |
7e7327a1 | 828 | int type; |
829 | int maclen, block_size; | |
830 | Enc *enc = NULL; | |
831 | Mac *mac = NULL; | |
832 | Comp *comp = NULL; | |
833 | ||
834 | if (kex != NULL) { | |
835 | enc = &kex->enc[MODE_IN]; | |
836 | mac = &kex->mac[MODE_IN]; | |
837 | comp = &kex->comp[MODE_IN]; | |
838 | } | |
839 | maclen = mac && mac->enabled ? mac->mac_len : 0; | |
94ec8c6b | 840 | block_size = enc ? enc->cipher->block_size : 8; |
7e7327a1 | 841 | |
842 | if (packet_length == 0) { | |
843 | /* | |
844 | * check if input size is less than the cipher block size, | |
845 | * decrypt first block and extract length of incoming packet | |
846 | */ | |
847 | if (buffer_len(&input) < block_size) | |
848 | return SSH_MSG_NONE; | |
849 | buffer_clear(&incoming_packet); | |
850 | buffer_append_space(&incoming_packet, &cp, block_size); | |
851 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), | |
852 | block_size); | |
1e3b8b07 | 853 | ucp = (u_char *) buffer_ptr(&incoming_packet); |
7e7327a1 | 854 | packet_length = GET_32BIT(ucp); |
855 | if (packet_length < 1 + 4 || packet_length > 256 * 1024) { | |
856 | buffer_dump(&incoming_packet); | |
857 | packet_disconnect("Bad packet length %d.", packet_length); | |
858 | } | |
859 | DBG(debug("input: packet len %d", packet_length+4)); | |
860 | buffer_consume(&input, block_size); | |
861 | } | |
862 | /* we have a partial packet of block_size bytes */ | |
863 | need = 4 + packet_length - block_size; | |
864 | DBG(debug("partial packet %d, need %d, maclen %d", block_size, | |
865 | need, maclen)); | |
866 | if (need % block_size != 0) | |
867 | fatal("padding error: need %d block %d mod %d", | |
868 | need, block_size, need % block_size); | |
869 | /* | |
870 | * check if the entire packet has been received and | |
871 | * decrypt into incoming_packet | |
872 | */ | |
873 | if (buffer_len(&input) < need + maclen) | |
874 | return SSH_MSG_NONE; | |
875 | #ifdef PACKET_DEBUG | |
876 | fprintf(stderr, "read_poll enc/full: "); | |
877 | buffer_dump(&input); | |
878 | #endif | |
879 | buffer_append_space(&incoming_packet, &cp, need); | |
880 | packet_decrypt(&receive_context, cp, buffer_ptr(&input), need); | |
881 | buffer_consume(&input, need); | |
882 | /* | |
883 | * compute MAC over seqnr and packet, | |
884 | * increment sequence number for incoming packet | |
885 | */ | |
6ae2364d | 886 | if (mac && mac->enabled) { |
7e7327a1 | 887 | macbuf = hmac( mac->md, seqnr, |
1e3b8b07 | 888 | (u_char *) buffer_ptr(&incoming_packet), |
7e7327a1 | 889 | buffer_len(&incoming_packet), |
890 | mac->key, mac->key_len | |
891 | ); | |
892 | if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0) | |
94ec8c6b | 893 | packet_disconnect("Corrupted MAC on input."); |
894 | DBG(debug("MAC #%d ok", seqnr)); | |
7e7327a1 | 895 | buffer_consume(&input, mac->mac_len); |
896 | } | |
6ae2364d | 897 | if (++seqnr == 0) |
898 | log("incoming seqnr wraps around"); | |
7e7327a1 | 899 | |
900 | /* get padlen */ | |
901 | cp = buffer_ptr(&incoming_packet) + 4; | |
902 | padlen = *cp & 0xff; | |
903 | DBG(debug("input: padlen %d", padlen)); | |
904 | if (padlen < 4) | |
905 | packet_disconnect("Corrupted padlen %d on input.", padlen); | |
906 | ||
907 | /* skip packet size + padlen, discard padding */ | |
908 | buffer_consume(&incoming_packet, 4 + 1); | |
909 | buffer_consume_end(&incoming_packet, padlen); | |
910 | ||
911 | DBG(debug("input: len before de-compress %d", buffer_len(&incoming_packet))); | |
912 | if (comp && comp->enabled) { | |
913 | buffer_clear(&compression_buffer); | |
914 | buffer_uncompress(&incoming_packet, &compression_buffer); | |
915 | buffer_clear(&incoming_packet); | |
916 | buffer_append(&incoming_packet, buffer_ptr(&compression_buffer), | |
917 | buffer_len(&compression_buffer)); | |
918 | DBG(debug("input: len after de-compress %d", buffer_len(&incoming_packet))); | |
919 | } | |
920 | /* | |
921 | * get packet type, implies consume. | |
922 | * return length of payload (without type field) | |
923 | */ | |
924 | buffer_get(&incoming_packet, (char *)&buf[0], 1); | |
925 | *payload_len_ptr = buffer_len(&incoming_packet); | |
926 | ||
927 | /* reset for next packet */ | |
928 | packet_length = 0; | |
929 | ||
930 | /* extract packet type */ | |
1e3b8b07 | 931 | type = (u_char)buf[0]; |
7e7327a1 | 932 | |
933 | if (type == SSH2_MSG_NEWKEYS) { | |
934 | if (kex==NULL || mac==NULL || enc==NULL || comp==NULL) | |
935 | fatal("packet_read_poll2: no KEX"); | |
936 | if (mac->md != NULL) | |
937 | mac->enabled = 1; | |
94ec8c6b | 938 | DBG(debug("cipher_init receive_context")); |
939 | cipher_init(&receive_context, enc->cipher, | |
940 | enc->key, enc->cipher->key_len, | |
941 | enc->iv, enc->cipher->block_size); | |
7e7327a1 | 942 | clear_enc_keys(enc, kex->we_need); |
943 | if (comp->type != 0 && comp->enabled == 0) { | |
944 | comp->enabled = 1; | |
945 | if (! packet_compression) | |
946 | packet_start_compression(6); | |
947 | } | |
948 | } | |
949 | ||
950 | #ifdef PACKET_DEBUG | |
951 | fprintf(stderr, "read/plain[%d]:\r\n",type); | |
952 | buffer_dump(&incoming_packet); | |
953 | #endif | |
1e3b8b07 | 954 | return (u_char)type; |
7e7327a1 | 955 | } |
956 | ||
957 | int | |
958 | packet_read_poll(int *payload_len_ptr) | |
959 | { | |
960 | char *msg; | |
961 | for (;;) { | |
962 | int type = use_ssh2_packet_format ? | |
963 | packet_read_poll2(payload_len_ptr): | |
964 | packet_read_poll1(payload_len_ptr); | |
965 | ||
966 | if(compat20) { | |
967 | int reason; | |
968 | if (type != 0) | |
969 | DBG(debug("received packet type %d", type)); | |
970 | switch(type) { | |
971 | case SSH2_MSG_IGNORE: | |
972 | break; | |
973 | case SSH2_MSG_DEBUG: | |
974 | packet_get_char(); | |
975 | msg = packet_get_string(NULL); | |
976 | debug("Remote: %.900s", msg); | |
977 | xfree(msg); | |
978 | msg = packet_get_string(NULL); | |
979 | xfree(msg); | |
980 | break; | |
981 | case SSH2_MSG_DISCONNECT: | |
982 | reason = packet_get_int(); | |
983 | msg = packet_get_string(NULL); | |
7c49df64 | 984 | log("Received disconnect from %s: %d: %.400s", get_remote_ipaddr(), |
985 | reason, msg); | |
7e7327a1 | 986 | xfree(msg); |
987 | fatal_cleanup(); | |
988 | break; | |
989 | default: | |
990 | return type; | |
991 | break; | |
992 | } | |
993 | } else { | |
994 | switch(type) { | |
995 | case SSH_MSG_IGNORE: | |
996 | break; | |
997 | case SSH_MSG_DEBUG: | |
998 | msg = packet_get_string(NULL); | |
999 | debug("Remote: %.900s", msg); | |
1000 | xfree(msg); | |
1001 | break; | |
1002 | case SSH_MSG_DISCONNECT: | |
1003 | msg = packet_get_string(NULL); | |
7c49df64 | 1004 | log("Received disconnect from %s: %.400s", get_remote_ipaddr(), |
1005 | msg); | |
7e7327a1 | 1006 | fatal_cleanup(); |
1007 | xfree(msg); | |
1008 | break; | |
1009 | default: | |
1010 | if (type != 0) | |
1011 | DBG(debug("received packet type %d", type)); | |
1012 | return type; | |
1013 | break; | |
1014 | } | |
1015 | } | |
1016 | } | |
1017 | } | |
1018 | ||
aa3378df | 1019 | /* |
1020 | * Buffers the given amount of input characters. This is intended to be used | |
1021 | * together with packet_read_poll. | |
1022 | */ | |
8efc0c15 | 1023 | |
1024 | void | |
1e3b8b07 | 1025 | packet_process_incoming(const char *buf, u_int len) |
8efc0c15 | 1026 | { |
5260325f | 1027 | buffer_append(&input, buf, len); |
8efc0c15 | 1028 | } |
1029 | ||
1030 | /* Returns a character from the packet. */ | |
1031 | ||
1e3b8b07 | 1032 | u_int |
8efc0c15 | 1033 | packet_get_char() |
1034 | { | |
5260325f | 1035 | char ch; |
1036 | buffer_get(&incoming_packet, &ch, 1); | |
1e3b8b07 | 1037 | return (u_char) ch; |
8efc0c15 | 1038 | } |
1039 | ||
1040 | /* Returns an integer from the packet data. */ | |
1041 | ||
1e3b8b07 | 1042 | u_int |
8efc0c15 | 1043 | packet_get_int() |
1044 | { | |
5260325f | 1045 | return buffer_get_int(&incoming_packet); |
8efc0c15 | 1046 | } |
1047 | ||
aa3378df | 1048 | /* |
1049 | * Returns an arbitrary precision integer from the packet data. The integer | |
1050 | * must have been initialized before this call. | |
1051 | */ | |
8efc0c15 | 1052 | |
1053 | void | |
5260325f | 1054 | packet_get_bignum(BIGNUM * value, int *length_ptr) |
8efc0c15 | 1055 | { |
5260325f | 1056 | *length_ptr = buffer_get_bignum(&incoming_packet, value); |
8efc0c15 | 1057 | } |
1058 | ||
7e7327a1 | 1059 | void |
1060 | packet_get_bignum2(BIGNUM * value, int *length_ptr) | |
1061 | { | |
1062 | *length_ptr = buffer_get_bignum2(&incoming_packet, value); | |
1063 | } | |
1064 | ||
1065 | char * | |
1066 | packet_get_raw(int *length_ptr) | |
1067 | { | |
1068 | int bytes = buffer_len(&incoming_packet); | |
1069 | if (length_ptr != NULL) | |
1070 | *length_ptr = bytes; | |
1071 | return buffer_ptr(&incoming_packet); | |
1072 | } | |
1073 | ||
6ae2364d | 1074 | int |
1075 | packet_remaining(void) | |
1076 | { | |
1077 | return buffer_len(&incoming_packet); | |
1078 | } | |
1079 | ||
aa3378df | 1080 | /* |
1081 | * Returns a string from the packet data. The string is allocated using | |
1082 | * xmalloc; it is the responsibility of the calling program to free it when | |
1083 | * no longer needed. The length_ptr argument may be NULL, or point to an | |
1084 | * integer into which the length of the string is stored. | |
1085 | */ | |
8efc0c15 | 1086 | |
aa3378df | 1087 | char * |
1e3b8b07 | 1088 | packet_get_string(u_int *length_ptr) |
8efc0c15 | 1089 | { |
5260325f | 1090 | return buffer_get_string(&incoming_packet, length_ptr); |
8efc0c15 | 1091 | } |
1092 | ||
aa3378df | 1093 | /* |
1094 | * Sends a diagnostic message from the server to the client. This message | |
1095 | * can be sent at any time (but not while constructing another message). The | |
1096 | * message is printed immediately, but only if the client is being executed | |
1097 | * in verbose mode. These messages are primarily intended to ease debugging | |
1098 | * authentication problems. The length of the formatted message must not | |
1099 | * exceed 1024 bytes. This will automatically call packet_write_wait. | |
1100 | */ | |
8efc0c15 | 1101 | |
1102 | void | |
5260325f | 1103 | packet_send_debug(const char *fmt,...) |
8efc0c15 | 1104 | { |
5260325f | 1105 | char buf[1024]; |
1106 | va_list args; | |
1107 | ||
f72fc97f | 1108 | if (compat20 && (datafellows & SSH_BUG_DEBUG)) |
1109 | return; | |
1110 | ||
5260325f | 1111 | va_start(args, fmt); |
1112 | vsnprintf(buf, sizeof(buf), fmt, args); | |
1113 | va_end(args); | |
1114 | ||
c4bc58eb | 1115 | if (compat20) { |
1116 | packet_start(SSH2_MSG_DEBUG); | |
1117 | packet_put_char(0); /* bool: always display */ | |
1118 | packet_put_cstring(buf); | |
1119 | packet_put_cstring(""); | |
1120 | } else { | |
1121 | packet_start(SSH_MSG_DEBUG); | |
1122 | packet_put_cstring(buf); | |
1123 | } | |
5260325f | 1124 | packet_send(); |
1125 | packet_write_wait(); | |
8efc0c15 | 1126 | } |
1127 | ||
aa3378df | 1128 | /* |
1129 | * Logs the error plus constructs and sends a disconnect packet, closes the | |
1130 | * connection, and exits. This function never returns. The error message | |
1131 | * should not contain a newline. The length of the formatted message must | |
1132 | * not exceed 1024 bytes. | |
1133 | */ | |
8efc0c15 | 1134 | |
1135 | void | |
5260325f | 1136 | packet_disconnect(const char *fmt,...) |
1137 | { | |
1138 | char buf[1024]; | |
1139 | va_list args; | |
1140 | static int disconnecting = 0; | |
1141 | if (disconnecting) /* Guard against recursive invocations. */ | |
1142 | fatal("packet_disconnect called recursively."); | |
1143 | disconnecting = 1; | |
1144 | ||
aa3378df | 1145 | /* |
1146 | * Format the message. Note that the caller must make sure the | |
1147 | * message is of limited size. | |
1148 | */ | |
5260325f | 1149 | va_start(args, fmt); |
1150 | vsnprintf(buf, sizeof(buf), fmt, args); | |
1151 | va_end(args); | |
1152 | ||
1153 | /* Send the disconnect message to the other side, and wait for it to get sent. */ | |
7e7327a1 | 1154 | if (compat20) { |
1155 | packet_start(SSH2_MSG_DISCONNECT); | |
1156 | packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR); | |
1157 | packet_put_cstring(buf); | |
1158 | packet_put_cstring(""); | |
1159 | } else { | |
1160 | packet_start(SSH_MSG_DISCONNECT); | |
1161 | packet_put_string(buf, strlen(buf)); | |
1162 | } | |
5260325f | 1163 | packet_send(); |
1164 | packet_write_wait(); | |
1165 | ||
1166 | /* Stop listening for connections. */ | |
1167 | channel_stop_listening(); | |
1168 | ||
1169 | /* Close the connection. */ | |
1170 | packet_close(); | |
1171 | ||
1172 | /* Display the error locally and exit. */ | |
57112b5a | 1173 | log("Disconnecting: %.100s", buf); |
1174 | fatal_cleanup(); | |
8efc0c15 | 1175 | } |
1176 | ||
aa3378df | 1177 | /* Checks if there is any buffered output, and tries to write some of the output. */ |
8efc0c15 | 1178 | |
1179 | void | |
1180 | packet_write_poll() | |
1181 | { | |
5260325f | 1182 | int len = buffer_len(&output); |
1183 | if (len > 0) { | |
1184 | len = write(connection_out, buffer_ptr(&output), len); | |
1185 | if (len <= 0) { | |
1186 | if (errno == EAGAIN) | |
1187 | return; | |
1188 | else | |
1189 | fatal("Write failed: %.100s", strerror(errno)); | |
1190 | } | |
1191 | buffer_consume(&output, len); | |
1192 | } | |
8efc0c15 | 1193 | } |
1194 | ||
aa3378df | 1195 | /* |
1196 | * Calls packet_write_poll repeatedly until all pending output data has been | |
1197 | * written. | |
1198 | */ | |
8efc0c15 | 1199 | |
1200 | void | |
1201 | packet_write_wait() | |
1202 | { | |
5260325f | 1203 | packet_write_poll(); |
1204 | while (packet_have_data_to_write()) { | |
1205 | fd_set set; | |
1206 | FD_ZERO(&set); | |
1207 | FD_SET(connection_out, &set); | |
1208 | select(connection_out + 1, NULL, &set, NULL, NULL); | |
1209 | packet_write_poll(); | |
1210 | } | |
8efc0c15 | 1211 | } |
1212 | ||
1213 | /* Returns true if there is buffered data to write to the connection. */ | |
1214 | ||
1215 | int | |
1216 | packet_have_data_to_write() | |
1217 | { | |
5260325f | 1218 | return buffer_len(&output) != 0; |
8efc0c15 | 1219 | } |
1220 | ||
1221 | /* Returns true if there is not too much data to write to the connection. */ | |
1222 | ||
1223 | int | |
1224 | packet_not_very_much_data_to_write() | |
1225 | { | |
5260325f | 1226 | if (interactive_mode) |
1227 | return buffer_len(&output) < 16384; | |
1228 | else | |
1229 | return buffer_len(&output) < 128 * 1024; | |
8efc0c15 | 1230 | } |
1231 | ||
1232 | /* Informs that the current session is interactive. Sets IP flags for that. */ | |
1233 | ||
1234 | void | |
b5c334cc | 1235 | packet_set_interactive(int interactive) |
8efc0c15 | 1236 | { |
b5c334cc | 1237 | static int called = 0; |
1238 | int lowdelay = IPTOS_LOWDELAY; | |
1239 | int throughput = IPTOS_THROUGHPUT; | |
5260325f | 1240 | int on = 1; |
1241 | ||
b5c334cc | 1242 | if (called) |
1243 | return; | |
1244 | called = 1; | |
1245 | ||
5260325f | 1246 | /* Record that we are in interactive mode. */ |
1247 | interactive_mode = interactive; | |
1248 | ||
48e671d5 | 1249 | /* Only set socket options if using a socket. */ |
1250 | if (!packet_connection_is_on_socket()) | |
5260325f | 1251 | return; |
48e671d5 | 1252 | /* |
f546c780 | 1253 | * IPTOS_LOWDELAY and IPTOS_THROUGHPUT are IPv4 only |
48e671d5 | 1254 | */ |
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) |
f546c780 | 1261 | if (packet_connection_is_ipv4()) { |
0e3c1f95 | 1262 | if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, |
f546c780 | 1263 | (void *) &lowdelay, sizeof(lowdelay)) < 0) |
0e3c1f95 | 1264 | error("setsockopt IPTOS_LOWDELAY: %.100s", |
f546c780 | 1265 | strerror(errno)); |
1266 | } | |
c04f75f1 | 1267 | #endif |
5260325f | 1268 | if (setsockopt(connection_in, IPPROTO_TCP, TCP_NODELAY, (void *) &on, |
48e671d5 | 1269 | sizeof(on)) < 0) |
5260325f | 1270 | error("setsockopt TCP_NODELAY: %.100s", strerror(errno)); |
f546c780 | 1271 | } else if (packet_connection_is_ipv4()) { |
aa3378df | 1272 | /* |
1273 | * Set IP options for a non-interactive connection. Use | |
1274 | * IPTOS_THROUGHPUT. | |
1275 | */ | |
132dd316 | 1276 | #if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN) |
5260325f | 1277 | if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &throughput, |
48e671d5 | 1278 | sizeof(throughput)) < 0) |
5260325f | 1279 | error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno)); |
c04f75f1 | 1280 | #endif |
5260325f | 1281 | } |
8efc0c15 | 1282 | } |
1283 | ||
1284 | /* Returns true if the current connection is interactive. */ | |
1285 | ||
1286 | int | |
1287 | packet_is_interactive() | |
1288 | { | |
5260325f | 1289 | return interactive_mode; |
8efc0c15 | 1290 | } |
9d6b7add | 1291 | |
1292 | int | |
1293 | packet_set_maxsize(int s) | |
1294 | { | |
5260325f | 1295 | static int called = 0; |
1296 | if (called) { | |
7e7327a1 | 1297 | log("packet_set_maxsize: called twice: old %d new %d", |
1298 | max_packet_size, s); | |
5260325f | 1299 | return -1; |
1300 | } | |
1301 | if (s < 4 * 1024 || s > 1024 * 1024) { | |
1302 | log("packet_set_maxsize: bad size %d", s); | |
1303 | return -1; | |
1304 | } | |
1305 | log("packet_set_maxsize: setting to %d", s); | |
1306 | max_packet_size = s; | |
1307 | return s; | |
9d6b7add | 1308 | } |