blob: 9aa686aa740d73715f33a9a16885b292cb8a458e [file] [log] [blame]
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001/*
Damien Miller95def091999-11-25 00:26:21 +11002 * Author: Tatu Ylonen <ylo@cs.hut.fi>
Damien Miller95def091999-11-25 00:26:21 +11003 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
4 * All rights reserved
Damien Miller95def091999-11-25 00:26:21 +11005 * 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.
Damien Miller33b13562000-04-04 14:38:59 +10007 *
Damien Millere4340be2000-09-16 13:29:08 +11008 * 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".
Damien Miller33b13562000-04-04 14:38:59 +100013 *
Damien Millere4340be2000-09-16 13:29:08 +110014 *
15 * SSH2 packet format added by Markus Friedl.
Ben Lindstrom44697232001-07-04 03:32:30 +000016 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
Damien Millere4340be2000-09-16 13:29:08 +110017 *
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.
26 *
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.
Damien Miller95def091999-11-25 00:26:21 +110037 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100038
39#include "includes.h"
Ben Lindstrom44697232001-07-04 03:32:30 +000040RCSID("$OpenBSD: packet.c,v 1.69 2001/06/25 08:25:38 markus Exp $");
Damien Millerd4a8b7e1999-10-27 13:42:43 +100041
42#include "xmalloc.h"
43#include "buffer.h"
44#include "packet.h"
45#include "bufaux.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100046#include "crc32.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100047#include "getput.h"
48
49#include "compress.h"
50#include "deattack.h"
Ben Lindstromc7637672001-06-09 00:36:26 +000051#include "channels.h"
Damien Millerd4a8b7e1999-10-27 13:42:43 +100052
Damien Miller33b13562000-04-04 14:38:59 +100053#include "compat.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000054#include "ssh1.h"
Damien Miller33b13562000-04-04 14:38:59 +100055#include "ssh2.h"
56
Damien Miller874d77b2000-10-14 16:23:11 +110057#include "cipher.h"
Damien Miller33b13562000-04-04 14:38:59 +100058#include "kex.h"
Ben Lindstrom06b33aa2001-02-15 03:01:59 +000059#include "mac.h"
Ben Lindstrom226cfa02001-01-22 05:34:40 +000060#include "log.h"
61#include "canohost.h"
Damien Miller33b13562000-04-04 14:38:59 +100062
63#ifdef PACKET_DEBUG
64#define DBG(x) x
65#else
66#define DBG(x)
67#endif
68
Damien Miller5428f641999-11-25 11:54:57 +110069/*
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 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100075static int connection_in = -1;
76static int connection_out = -1;
77
Damien Millerd4a8b7e1999-10-27 13:42:43 +100078/* Protocol flags for the remote side. */
Ben Lindstrom46c16222000-12-22 01:43:59 +000079static u_int remote_protocol_flags = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +100080
81/* Encryption context for receiving data. This is only used for decryption. */
82static CipherContext receive_context;
Damien Miller95def091999-11-25 00:26:21 +110083
84/* Encryption context for sending data. This is only used for encryption. */
Damien Millerd4a8b7e1999-10-27 13:42:43 +100085static CipherContext send_context;
86
87/* Buffer for raw input data from the socket. */
88static Buffer input;
89
90/* Buffer for raw output data going to the socket. */
91static Buffer output;
92
93/* Buffer for the partial outgoing packet being constructed. */
94static Buffer outgoing_packet;
95
96/* Buffer for the incoming packet currently being processed. */
97static Buffer incoming_packet;
98
99/* Scratch buffer for packet compression/decompression. */
100static Buffer compression_buffer;
Ben Lindstromfb50cdf2001-04-05 23:20:46 +0000101static int compression_buffer_ready = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000102
103/* Flag indicating whether packet compression/decompression is enabled. */
104static int packet_compression = 0;
105
Damien Miller6162d121999-11-21 13:23:52 +1100106/* default maximum packet size */
107int max_packet_size = 32768;
108
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000109/* Flag indicating whether this module has been initialized. */
110static int initialized = 0;
111
112/* Set to true if the connection is interactive. */
113static int interactive_mode = 0;
114
Damien Miller33b13562000-04-04 14:38:59 +1000115/* Session key information for Encryption and MAC */
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000116Newkeys *newkeys[MODE_MAX];
Damien Miller33b13562000-04-04 14:38:59 +1000117
Damien Miller5428f641999-11-25 11:54:57 +1100118/*
119 * Sets the descriptors used for communication. Disables encryption until
120 * packet_set_encryption_key is called.
121 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000122void
123packet_set_connection(int fd_in, int fd_out)
124{
Damien Miller874d77b2000-10-14 16:23:11 +1100125 Cipher *none = cipher_by_name("none");
126 if (none == NULL)
127 fatal("packet_set_connection: cannot load cipher 'none'");
Damien Miller95def091999-11-25 00:26:21 +1100128 connection_in = fd_in;
129 connection_out = fd_out;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000130 cipher_init(&send_context, none, (u_char *) "", 0, NULL, 0);
131 cipher_init(&receive_context, none, (u_char *) "", 0, NULL, 0);
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000132 newkeys[MODE_IN] = newkeys[MODE_OUT] = NULL;
Damien Miller95def091999-11-25 00:26:21 +1100133 if (!initialized) {
134 initialized = 1;
135 buffer_init(&input);
136 buffer_init(&output);
137 buffer_init(&outgoing_packet);
138 buffer_init(&incoming_packet);
139 }
140 /* Kludge: arrange the close function to be called from fatal(). */
141 fatal_add_cleanup((void (*) (void *)) packet_close, NULL);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000142}
143
Damien Miller34132e52000-01-14 15:45:46 +1100144/* Returns 1 if remote host is connected via socket, 0 if not. */
145
146int
147packet_connection_is_on_socket()
148{
149 struct sockaddr_storage from, to;
150 socklen_t fromlen, tolen;
151
152 /* filedescriptors in and out are the same, so it's a socket */
153 if (connection_in == connection_out)
154 return 1;
155 fromlen = sizeof(from);
156 memset(&from, 0, sizeof(from));
Damien Millerf052aaf2000-01-22 19:47:21 +1100157 if (getpeername(connection_in, (struct sockaddr *)&from, &fromlen) < 0)
Damien Miller34132e52000-01-14 15:45:46 +1100158 return 0;
159 tolen = sizeof(to);
160 memset(&to, 0, sizeof(to));
Damien Millerf052aaf2000-01-22 19:47:21 +1100161 if (getpeername(connection_out, (struct sockaddr *)&to, &tolen) < 0)
Damien Miller34132e52000-01-14 15:45:46 +1100162 return 0;
163 if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
164 return 0;
165 if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
166 return 0;
167 return 1;
168}
169
170/* returns 1 if connection is via ipv4 */
171
172int
173packet_connection_is_ipv4()
174{
175 struct sockaddr_storage to;
Damien Miller6fe375d2000-01-23 09:38:00 +1100176 socklen_t tolen = sizeof(to);
Damien Miller34132e52000-01-14 15:45:46 +1100177
178 memset(&to, 0, sizeof(to));
179 if (getsockname(connection_out, (struct sockaddr *)&to, &tolen) < 0)
180 return 0;
181 if (to.ss_family != AF_INET)
182 return 0;
183 return 1;
184}
185
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000186/* Sets the connection into non-blocking mode. */
187
188void
189packet_set_nonblocking()
190{
Damien Miller95def091999-11-25 00:26:21 +1100191 /* Set the socket into non-blocking mode. */
192 if (fcntl(connection_in, F_SETFL, O_NONBLOCK) < 0)
193 error("fcntl O_NONBLOCK: %.100s", strerror(errno));
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000194
Damien Miller95def091999-11-25 00:26:21 +1100195 if (connection_out != connection_in) {
196 if (fcntl(connection_out, F_SETFL, O_NONBLOCK) < 0)
197 error("fcntl O_NONBLOCK: %.100s", strerror(errno));
198 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000199}
200
201/* Returns the socket used for reading. */
202
203int
204packet_get_connection_in()
205{
Damien Miller95def091999-11-25 00:26:21 +1100206 return connection_in;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000207}
208
209/* Returns the descriptor used for writing. */
210
211int
212packet_get_connection_out()
213{
Damien Miller95def091999-11-25 00:26:21 +1100214 return connection_out;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000215}
216
217/* Closes the connection and clears and frees internal data structures. */
218
219void
220packet_close()
221{
Damien Miller95def091999-11-25 00:26:21 +1100222 if (!initialized)
223 return;
224 initialized = 0;
225 if (connection_in == connection_out) {
226 shutdown(connection_out, SHUT_RDWR);
227 close(connection_out);
228 } else {
229 close(connection_in);
230 close(connection_out);
231 }
232 buffer_free(&input);
233 buffer_free(&output);
234 buffer_free(&outgoing_packet);
235 buffer_free(&incoming_packet);
Ben Lindstromfb50cdf2001-04-05 23:20:46 +0000236 if (compression_buffer_ready) {
Damien Miller95def091999-11-25 00:26:21 +1100237 buffer_free(&compression_buffer);
238 buffer_compress_uninit();
239 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000240}
241
242/* Sets remote side protocol flags. */
243
244void
Ben Lindstrom46c16222000-12-22 01:43:59 +0000245packet_set_protocol_flags(u_int protocol_flags)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000246{
Damien Miller95def091999-11-25 00:26:21 +1100247 remote_protocol_flags = protocol_flags;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000248}
249
250/* Returns the remote protocol flags set earlier by the above function. */
251
Ben Lindstrom46c16222000-12-22 01:43:59 +0000252u_int
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000253packet_get_protocol_flags()
254{
Damien Miller95def091999-11-25 00:26:21 +1100255 return remote_protocol_flags;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000256}
257
Damien Miller5428f641999-11-25 11:54:57 +1100258/*
259 * Starts packet compression from the next packet on in both directions.
260 * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
261 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000262
Ben Lindstrombba81212001-06-25 05:01:22 +0000263static void
264packet_init_compression(void)
Ben Lindstromfb50cdf2001-04-05 23:20:46 +0000265{
266 if (compression_buffer_ready == 1)
267 return;
268 compression_buffer_ready = 1;
269 buffer_init(&compression_buffer);
270}
271
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000272void
273packet_start_compression(int level)
274{
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000275 if (packet_compression && !compat20)
Damien Miller95def091999-11-25 00:26:21 +1100276 fatal("Compression already enabled.");
277 packet_compression = 1;
Ben Lindstromfb50cdf2001-04-05 23:20:46 +0000278 packet_init_compression();
279 buffer_compress_init_send(level);
280 buffer_compress_init_recv();
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000281}
282
Damien Miller5428f641999-11-25 11:54:57 +1100283/*
Damien Miller5428f641999-11-25 11:54:57 +1100284 * Causes any further packets to be encrypted using the given key. The same
285 * key is used for both sending and reception. However, both directions are
286 * encrypted independently of each other.
287 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000288void
Ben Lindstrom46c16222000-12-22 01:43:59 +0000289packet_set_encryption_key(const u_char *key, u_int keylen,
Damien Miller874d77b2000-10-14 16:23:11 +1100290 int number)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000291{
Damien Miller874d77b2000-10-14 16:23:11 +1100292 Cipher *cipher = cipher_by_number(number);
293 if (cipher == NULL)
294 fatal("packet_set_encryption_key: unknown cipher number %d", number);
Damien Miller33b13562000-04-04 14:38:59 +1000295 if (keylen < 20)
Damien Miller874d77b2000-10-14 16:23:11 +1100296 fatal("packet_set_encryption_key: keylen too small: %d", keylen);
297 cipher_init(&receive_context, cipher, key, keylen, NULL, 0);
298 cipher_init(&send_context, cipher, key, keylen, NULL, 0);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000299}
300
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000301/* Start constructing a packet to send. */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000302void
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000303packet_start(u_char type)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000304{
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000305 u_char buf[9];
306 int len;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000307
Ben Lindstrom204e4882001-03-05 06:47:00 +0000308 DBG(debug("packet_start[%d]", type));
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000309 len = compat20 ? 6 : 9;
310 memset(buf, 0, len - 1);
311 buf[len - 1] = type;
312 buffer_clear(&outgoing_packet);
313 buffer_append(&outgoing_packet, buf, len);
Damien Miller33b13562000-04-04 14:38:59 +1000314}
315
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000316/* Append payload. */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000317void
318packet_put_char(int value)
319{
Damien Miller95def091999-11-25 00:26:21 +1100320 char ch = value;
321 buffer_append(&outgoing_packet, &ch, 1);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000322}
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000323void
Ben Lindstrom46c16222000-12-22 01:43:59 +0000324packet_put_int(u_int value)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000325{
Damien Miller95def091999-11-25 00:26:21 +1100326 buffer_put_int(&outgoing_packet, value);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000327}
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000328void
Ben Lindstrom46c16222000-12-22 01:43:59 +0000329packet_put_string(const char *buf, u_int len)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000330{
Damien Miller95def091999-11-25 00:26:21 +1100331 buffer_put_string(&outgoing_packet, buf, len);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000332}
Damien Miller33b13562000-04-04 14:38:59 +1000333void
334packet_put_cstring(const char *str)
335{
Ben Lindstrom664408d2001-06-09 01:42:01 +0000336 buffer_put_cstring(&outgoing_packet, str);
Damien Miller33b13562000-04-04 14:38:59 +1000337}
Damien Miller33b13562000-04-04 14:38:59 +1000338void
Ben Lindstrom46c16222000-12-22 01:43:59 +0000339packet_put_raw(const char *buf, u_int len)
Damien Miller33b13562000-04-04 14:38:59 +1000340{
341 buffer_append(&outgoing_packet, buf, len);
342}
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000343void
Damien Miller95def091999-11-25 00:26:21 +1100344packet_put_bignum(BIGNUM * value)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000345{
Damien Miller95def091999-11-25 00:26:21 +1100346 buffer_put_bignum(&outgoing_packet, value);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000347}
Damien Miller33b13562000-04-04 14:38:59 +1000348void
349packet_put_bignum2(BIGNUM * value)
350{
351 buffer_put_bignum2(&outgoing_packet, value);
352}
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000353
Damien Miller5428f641999-11-25 11:54:57 +1100354/*
355 * Finalizes and sends the packet. If the encryption key has been set,
356 * encrypts the packet before sending.
357 */
Damien Miller95def091999-11-25 00:26:21 +1100358
Ben Lindstrombba81212001-06-25 05:01:22 +0000359static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000360packet_send1(void)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000361{
Damien Miller95def091999-11-25 00:26:21 +1100362 char buf[8], *cp;
363 int i, padding, len;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000364 u_int checksum;
Damien Miller95def091999-11-25 00:26:21 +1100365 u_int32_t rand = 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000366
Damien Miller5428f641999-11-25 11:54:57 +1100367 /*
368 * If using packet compression, compress the payload of the outgoing
369 * packet.
370 */
Damien Miller95def091999-11-25 00:26:21 +1100371 if (packet_compression) {
372 buffer_clear(&compression_buffer);
373 /* Skip padding. */
374 buffer_consume(&outgoing_packet, 8);
375 /* padding */
376 buffer_append(&compression_buffer, "\0\0\0\0\0\0\0\0", 8);
377 buffer_compress(&outgoing_packet, &compression_buffer);
378 buffer_clear(&outgoing_packet);
379 buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer),
380 buffer_len(&compression_buffer));
381 }
382 /* Compute packet length without padding (add checksum, remove padding). */
383 len = buffer_len(&outgoing_packet) + 4 - 8;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000384
Damien Millere247cc42000-05-07 12:03:14 +1000385 /* Insert padding. Initialized to zero in packet_start1() */
Damien Miller95def091999-11-25 00:26:21 +1100386 padding = 8 - len % 8;
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000387 if (send_context.cipher->number != SSH_CIPHER_NONE) {
Damien Miller95def091999-11-25 00:26:21 +1100388 cp = buffer_ptr(&outgoing_packet);
389 for (i = 0; i < padding; i++) {
390 if (i % 4 == 0)
391 rand = arc4random();
392 cp[7 - i] = rand & 0xff;
393 rand >>= 8;
394 }
395 }
396 buffer_consume(&outgoing_packet, 8 - padding);
397
398 /* Add check bytes. */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000399 checksum = ssh_crc32((u_char *) buffer_ptr(&outgoing_packet),
Damien Millerad833b32000-08-23 10:46:23 +1000400 buffer_len(&outgoing_packet));
Damien Miller95def091999-11-25 00:26:21 +1100401 PUT_32BIT(buf, checksum);
402 buffer_append(&outgoing_packet, buf, 4);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000403
404#ifdef PACKET_DEBUG
Damien Miller95def091999-11-25 00:26:21 +1100405 fprintf(stderr, "packet_send plain: ");
406 buffer_dump(&outgoing_packet);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000407#endif
408
Damien Miller95def091999-11-25 00:26:21 +1100409 /* Append to output. */
410 PUT_32BIT(buf, len);
411 buffer_append(&output, buf, 4);
412 buffer_append_space(&output, &cp, buffer_len(&outgoing_packet));
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000413 cipher_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet),
Damien Miller95def091999-11-25 00:26:21 +1100414 buffer_len(&outgoing_packet));
415
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000416#ifdef PACKET_DEBUG
Damien Miller95def091999-11-25 00:26:21 +1100417 fprintf(stderr, "encrypted: ");
418 buffer_dump(&output);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000419#endif
420
Damien Miller95def091999-11-25 00:26:21 +1100421 buffer_clear(&outgoing_packet);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000422
Damien Miller5428f641999-11-25 11:54:57 +1100423 /*
424 * Note that the packet is now only buffered in output. It won\'t be
425 * actually sent until packet_write_wait or packet_write_poll is
426 * called.
427 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000428}
429
Ben Lindstrombba81212001-06-25 05:01:22 +0000430static void
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000431set_newkeys(int mode)
432{
433 Enc *enc;
434 Mac *mac;
435 Comp *comp;
436 CipherContext *cc;
437
438 debug("newkeys: mode %d", mode);
439
440 cc = (mode == MODE_OUT) ? &send_context : &receive_context;
441 if (newkeys[mode] != NULL) {
442 debug("newkeys: rekeying");
Ben Lindstrom238abf62001-04-04 17:52:53 +0000443 /* todo: free old keys, reset compression/cipher-ctxt; */
Ben Lindstrom5ba23b32001-04-05 02:05:21 +0000444 memset(cc, 0, sizeof(*cc));
445 enc = &newkeys[mode]->enc;
446 mac = &newkeys[mode]->mac;
447 comp = &newkeys[mode]->comp;
Ben Lindstroma3700052001-04-05 23:26:32 +0000448 memset(mac->key, 0, mac->key_len);
Ben Lindstrom5ba23b32001-04-05 02:05:21 +0000449 xfree(enc->name);
450 xfree(enc->iv);
451 xfree(enc->key);
452 xfree(mac->name);
453 xfree(mac->key);
454 xfree(comp->name);
Ben Lindstrom238abf62001-04-04 17:52:53 +0000455 xfree(newkeys[mode]);
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000456 }
457 newkeys[mode] = kex_get_newkeys(mode);
458 if (newkeys[mode] == NULL)
459 fatal("newkeys: no keys for mode %d", mode);
460 enc = &newkeys[mode]->enc;
461 mac = &newkeys[mode]->mac;
462 comp = &newkeys[mode]->comp;
463 if (mac->md != NULL)
464 mac->enabled = 1;
465 DBG(debug("cipher_init_context: %d", mode));
466 cipher_init(cc, enc->cipher, enc->key, enc->cipher->key_len,
467 enc->iv, enc->cipher->block_size);
Ben Lindstrom5ba23b32001-04-05 02:05:21 +0000468 memset(enc->iv, 0, enc->cipher->block_size);
469 memset(enc->key, 0, enc->cipher->key_len);
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000470 if (comp->type != 0 && comp->enabled == 0) {
Ben Lindstromfb50cdf2001-04-05 23:20:46 +0000471 packet_init_compression();
472 if (mode == MODE_OUT)
473 buffer_compress_init_send(6);
474 else
475 buffer_compress_init_recv();
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000476 comp->enabled = 1;
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000477 }
478}
479
Damien Miller5428f641999-11-25 11:54:57 +1100480/*
Damien Miller33b13562000-04-04 14:38:59 +1000481 * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
482 */
Ben Lindstrombba81212001-06-25 05:01:22 +0000483static void
Ben Lindstrom31ca54a2001-02-09 02:11:24 +0000484packet_send2(void)
Damien Miller33b13562000-04-04 14:38:59 +1000485{
Ben Lindstrom06b33aa2001-02-15 03:01:59 +0000486 static u_int32_t seqnr = 0;
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000487 u_char type, *ucp, *macbuf = NULL;
Damien Miller33b13562000-04-04 14:38:59 +1000488 char *cp;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000489 u_int packet_length = 0;
490 u_int i, padlen, len;
Damien Miller33b13562000-04-04 14:38:59 +1000491 u_int32_t rand = 0;
Damien Miller33b13562000-04-04 14:38:59 +1000492 Enc *enc = NULL;
493 Mac *mac = NULL;
494 Comp *comp = NULL;
495 int block_size;
496
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000497 if (newkeys[MODE_OUT] != NULL) {
498 enc = &newkeys[MODE_OUT]->enc;
499 mac = &newkeys[MODE_OUT]->mac;
500 comp = &newkeys[MODE_OUT]->comp;
Damien Miller33b13562000-04-04 14:38:59 +1000501 }
Damien Miller874d77b2000-10-14 16:23:11 +1100502 block_size = enc ? enc->cipher->block_size : 8;
Damien Miller33b13562000-04-04 14:38:59 +1000503
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000504 ucp = (u_char *) buffer_ptr(&outgoing_packet);
505 type = ucp[5];
Damien Miller33b13562000-04-04 14:38:59 +1000506
507#ifdef PACKET_DEBUG
508 fprintf(stderr, "plain: ");
509 buffer_dump(&outgoing_packet);
510#endif
511
512 if (comp && comp->enabled) {
513 len = buffer_len(&outgoing_packet);
514 /* skip header, compress only payload */
515 buffer_consume(&outgoing_packet, 5);
516 buffer_clear(&compression_buffer);
517 buffer_compress(&outgoing_packet, &compression_buffer);
518 buffer_clear(&outgoing_packet);
519 buffer_append(&outgoing_packet, "\0\0\0\0\0", 5);
520 buffer_append(&outgoing_packet, buffer_ptr(&compression_buffer),
521 buffer_len(&compression_buffer));
522 DBG(debug("compression: raw %d compressed %d", len,
523 buffer_len(&outgoing_packet)));
524 }
525
526 /* sizeof (packet_len + pad_len + payload) */
527 len = buffer_len(&outgoing_packet);
528
529 /*
530 * calc size of padding, alloc space, get random data,
531 * minimum padding is 4 bytes
532 */
533 padlen = block_size - (len % block_size);
534 if (padlen < 4)
535 padlen += block_size;
536 buffer_append_space(&outgoing_packet, &cp, padlen);
Damien Miller874d77b2000-10-14 16:23:11 +1100537 if (enc && enc->cipher->number != SSH_CIPHER_NONE) {
Damien Millere247cc42000-05-07 12:03:14 +1000538 /* random padding */
Damien Miller33b13562000-04-04 14:38:59 +1000539 for (i = 0; i < padlen; i++) {
540 if (i % 4 == 0)
541 rand = arc4random();
542 cp[i] = rand & 0xff;
Ben Lindstrom6a5cde02001-03-05 06:07:00 +0000543 rand >>= 8;
Damien Miller33b13562000-04-04 14:38:59 +1000544 }
Damien Millere247cc42000-05-07 12:03:14 +1000545 } else {
546 /* clear padding */
547 memset(cp, 0, padlen);
Damien Miller33b13562000-04-04 14:38:59 +1000548 }
549 /* packet_length includes payload, padding and padding length field */
550 packet_length = buffer_len(&outgoing_packet) - 4;
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000551 ucp = (u_char *)buffer_ptr(&outgoing_packet);
552 PUT_32BIT(ucp, packet_length);
553 ucp[4] = padlen;
Damien Miller33b13562000-04-04 14:38:59 +1000554 DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen));
555
556 /* compute MAC over seqnr and packet(length fields, payload, padding) */
557 if (mac && mac->enabled) {
Ben Lindstrom06b33aa2001-02-15 03:01:59 +0000558 macbuf = mac_compute(mac, seqnr,
Ben Lindstrom46c16222000-12-22 01:43:59 +0000559 (u_char *) buffer_ptr(&outgoing_packet),
Ben Lindstrom06b33aa2001-02-15 03:01:59 +0000560 buffer_len(&outgoing_packet));
Damien Miller874d77b2000-10-14 16:23:11 +1100561 DBG(debug("done calc MAC out #%d", seqnr));
Damien Miller33b13562000-04-04 14:38:59 +1000562 }
563 /* encrypt packet and append to output buffer. */
564 buffer_append_space(&output, &cp, buffer_len(&outgoing_packet));
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000565 cipher_encrypt(&send_context, cp, buffer_ptr(&outgoing_packet),
Damien Miller33b13562000-04-04 14:38:59 +1000566 buffer_len(&outgoing_packet));
567 /* append unencrypted MAC */
568 if (mac && mac->enabled)
569 buffer_append(&output, (char *)macbuf, mac->mac_len);
570#ifdef PACKET_DEBUG
571 fprintf(stderr, "encrypted: ");
572 buffer_dump(&output);
573#endif
Damien Miller4af51302000-04-16 11:18:38 +1000574 /* increment sequence number for outgoing packets */
575 if (++seqnr == 0)
576 log("outgoing seqnr wraps around");
Damien Miller33b13562000-04-04 14:38:59 +1000577 buffer_clear(&outgoing_packet);
578
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000579 if (type == SSH2_MSG_NEWKEYS)
580 set_newkeys(MODE_OUT);
Damien Miller33b13562000-04-04 14:38:59 +1000581}
582
583void
584packet_send()
585{
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000586 if (compat20)
Damien Miller33b13562000-04-04 14:38:59 +1000587 packet_send2();
588 else
589 packet_send1();
590 DBG(debug("packet_send done"));
591}
592
Damien Miller33b13562000-04-04 14:38:59 +1000593/*
Damien Miller5428f641999-11-25 11:54:57 +1100594 * Waits until a packet has been received, and returns its type. Note that
595 * no other data is processed until this returns, so this function should not
596 * be used during the interactive session.
597 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000598
599int
600packet_read(int *payload_len_ptr)
601{
Damien Miller95def091999-11-25 00:26:21 +1100602 int type, len;
Ben Lindstromcb978aa2001-03-05 07:07:49 +0000603 fd_set *setp;
Damien Miller95def091999-11-25 00:26:21 +1100604 char buf[8192];
Damien Miller33b13562000-04-04 14:38:59 +1000605 DBG(debug("packet_read()"));
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000606
Ben Lindstromcb978aa2001-03-05 07:07:49 +0000607 setp = (fd_set *)xmalloc(howmany(connection_in+1, NFDBITS) *
608 sizeof(fd_mask));
609
Damien Miller95def091999-11-25 00:26:21 +1100610 /* Since we are blocking, ensure that all written packets have been sent. */
611 packet_write_wait();
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000612
Damien Miller95def091999-11-25 00:26:21 +1100613 /* Stay in the loop until we have received a complete packet. */
614 for (;;) {
615 /* Try to read a packet from the buffer. */
616 type = packet_read_poll(payload_len_ptr);
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000617 if (!compat20 && (
Damien Millere247cc42000-05-07 12:03:14 +1000618 type == SSH_SMSG_SUCCESS
Damien Miller95def091999-11-25 00:26:21 +1100619 || type == SSH_SMSG_FAILURE
620 || type == SSH_CMSG_EOF
Damien Millere247cc42000-05-07 12:03:14 +1000621 || type == SSH_CMSG_EXIT_CONFIRMATION))
Damien Miller95def091999-11-25 00:26:21 +1100622 packet_integrity_check(*payload_len_ptr, 0, type);
623 /* If we got a packet, return it. */
Ben Lindstromcb978aa2001-03-05 07:07:49 +0000624 if (type != SSH_MSG_NONE) {
625 xfree(setp);
Damien Miller95def091999-11-25 00:26:21 +1100626 return type;
Ben Lindstromcb978aa2001-03-05 07:07:49 +0000627 }
Damien Miller5428f641999-11-25 11:54:57 +1100628 /*
629 * Otherwise, wait for some data to arrive, add it to the
630 * buffer, and try again.
631 */
Ben Lindstromcb978aa2001-03-05 07:07:49 +0000632 memset(setp, 0, howmany(connection_in + 1, NFDBITS) *
633 sizeof(fd_mask));
634 FD_SET(connection_in, setp);
Damien Miller5428f641999-11-25 11:54:57 +1100635
Damien Miller95def091999-11-25 00:26:21 +1100636 /* Wait for some data to arrive. */
Ben Lindstromcb978aa2001-03-05 07:07:49 +0000637 while (select(connection_in + 1, setp, NULL, NULL, NULL) == -1 &&
Ben Lindstromf9452512001-02-15 03:12:08 +0000638 (errno == EAGAIN || errno == EINTR))
639 ;
Damien Miller5428f641999-11-25 11:54:57 +1100640
Damien Miller95def091999-11-25 00:26:21 +1100641 /* Read data from the socket. */
642 len = read(connection_in, buf, sizeof(buf));
Damien Miller5e7c10e1999-12-16 13:18:04 +1100643 if (len == 0) {
644 log("Connection closed by %.200s", get_remote_ipaddr());
645 fatal_cleanup();
646 }
Damien Miller95def091999-11-25 00:26:21 +1100647 if (len < 0)
648 fatal("Read from socket failed: %.100s", strerror(errno));
649 /* Append it to the buffer. */
650 packet_process_incoming(buf, len);
651 }
652 /* NOTREACHED */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000653}
654
Damien Miller5428f641999-11-25 11:54:57 +1100655/*
656 * Waits until a packet has been received, verifies that its type matches
657 * that given, and gives a fatal error and exits if there is a mismatch.
658 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000659
660void
661packet_read_expect(int *payload_len_ptr, int expected_type)
662{
Damien Miller95def091999-11-25 00:26:21 +1100663 int type;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000664
Damien Miller95def091999-11-25 00:26:21 +1100665 type = packet_read(payload_len_ptr);
666 if (type != expected_type)
667 packet_disconnect("Protocol error: expected packet type %d, got %d",
Damien Miller33b13562000-04-04 14:38:59 +1000668 expected_type, type);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000669}
670
671/* Checks if a full packet is available in the data received so far via
Damien Miller95def091999-11-25 00:26:21 +1100672 * packet_process_incoming. If so, reads the packet; otherwise returns
673 * SSH_MSG_NONE. This does not wait for data from the connection.
674 *
675 * SSH_MSG_DISCONNECT is handled specially here. Also,
676 * SSH_MSG_IGNORE messages are skipped by this function and are never returned
677 * to higher levels.
678 *
679 * The returned payload_len does include space consumed by:
680 * Packet length
681 * Padding
682 * Packet type
683 * Check bytes
684 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000685
Ben Lindstrombba81212001-06-25 05:01:22 +0000686static int
Damien Miller33b13562000-04-04 14:38:59 +1000687packet_read_poll1(int *payload_len_ptr)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000688{
Ben Lindstrom46c16222000-12-22 01:43:59 +0000689 u_int len, padded_len;
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000690 u_char *ucp, type;
691 char *cp;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000692 u_int checksum, stored_checksum;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000693
Damien Miller95def091999-11-25 00:26:21 +1100694 /* Check if input size is less than minimum packet size. */
695 if (buffer_len(&input) < 4 + 8)
696 return SSH_MSG_NONE;
697 /* Get length of incoming packet. */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000698 ucp = (u_char *) buffer_ptr(&input);
Damien Miller95def091999-11-25 00:26:21 +1100699 len = GET_32BIT(ucp);
700 if (len < 1 + 2 + 2 || len > 256 * 1024)
701 packet_disconnect("Bad packet length %d.", len);
702 padded_len = (len + 8) & ~7;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000703
Damien Miller95def091999-11-25 00:26:21 +1100704 /* Check if the packet has been entirely received. */
705 if (buffer_len(&input) < 4 + padded_len)
706 return SSH_MSG_NONE;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000707
Damien Miller95def091999-11-25 00:26:21 +1100708 /* The entire packet is in buffer. */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000709
Damien Miller95def091999-11-25 00:26:21 +1100710 /* Consume packet length. */
711 buffer_consume(&input, 4);
712
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000713 /*
714 * Cryptographic attack detector for ssh
715 * (C)1998 CORE-SDI, Buenos Aires Argentina
716 * Ariel Futoransky(futo@core-sdi.com)
717 */
718 if (receive_context.cipher->number != SSH_CIPHER_NONE &&
719 detect_attack(buffer_ptr(&input), padded_len, NULL) == DEATTACK_DETECTED)
720 packet_disconnect("crc32 compensation attack: network attack detected");
721
722 /* Decrypt data to incoming_packet. */
Damien Miller95def091999-11-25 00:26:21 +1100723 buffer_clear(&incoming_packet);
724 buffer_append_space(&incoming_packet, &cp, padded_len);
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000725 cipher_decrypt(&receive_context, cp, buffer_ptr(&input), padded_len);
726
Damien Miller95def091999-11-25 00:26:21 +1100727 buffer_consume(&input, padded_len);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000728
729#ifdef PACKET_DEBUG
Damien Miller95def091999-11-25 00:26:21 +1100730 fprintf(stderr, "read_poll plain: ");
731 buffer_dump(&incoming_packet);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000732#endif
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000733
Damien Miller95def091999-11-25 00:26:21 +1100734 /* Compute packet checksum. */
Ben Lindstrom46c16222000-12-22 01:43:59 +0000735 checksum = ssh_crc32((u_char *) buffer_ptr(&incoming_packet),
Damien Miller33b13562000-04-04 14:38:59 +1000736 buffer_len(&incoming_packet) - 4);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000737
Damien Miller95def091999-11-25 00:26:21 +1100738 /* Skip padding. */
739 buffer_consume(&incoming_packet, 8 - len % 8);
Damien Millerfd7c9111999-11-08 16:15:55 +1100740
Damien Miller95def091999-11-25 00:26:21 +1100741 /* Test check bytes. */
Damien Miller95def091999-11-25 00:26:21 +1100742 if (len != buffer_len(&incoming_packet))
743 packet_disconnect("packet_read_poll: len %d != buffer_len %d.",
Damien Miller33b13562000-04-04 14:38:59 +1000744 len, buffer_len(&incoming_packet));
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000745
Ben Lindstrom46c16222000-12-22 01:43:59 +0000746 ucp = (u_char *) buffer_ptr(&incoming_packet) + len - 4;
Damien Miller95def091999-11-25 00:26:21 +1100747 stored_checksum = GET_32BIT(ucp);
748 if (checksum != stored_checksum)
749 packet_disconnect("Corrupted check bytes on input.");
750 buffer_consume_end(&incoming_packet, 4);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000751
Damien Miller95def091999-11-25 00:26:21 +1100752 if (packet_compression) {
753 buffer_clear(&compression_buffer);
754 buffer_uncompress(&incoming_packet, &compression_buffer);
755 buffer_clear(&incoming_packet);
756 buffer_append(&incoming_packet, buffer_ptr(&compression_buffer),
Damien Miller33b13562000-04-04 14:38:59 +1000757 buffer_len(&compression_buffer));
Damien Miller95def091999-11-25 00:26:21 +1100758 }
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000759 type = buffer_get_char(&incoming_packet);
Damien Miller95def091999-11-25 00:26:21 +1100760 *payload_len_ptr = buffer_len(&incoming_packet);
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000761 return type;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000762}
Damien Miller95def091999-11-25 00:26:21 +1100763
Ben Lindstrombba81212001-06-25 05:01:22 +0000764static int
Damien Miller33b13562000-04-04 14:38:59 +1000765packet_read_poll2(int *payload_len_ptr)
766{
Ben Lindstrom06b33aa2001-02-15 03:01:59 +0000767 static u_int32_t seqnr = 0;
768 static u_int packet_length = 0;
Ben Lindstrom46c16222000-12-22 01:43:59 +0000769 u_int padlen, need;
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000770 u_char *macbuf, *ucp, type;
Damien Miller33b13562000-04-04 14:38:59 +1000771 char *cp;
Damien Miller33b13562000-04-04 14:38:59 +1000772 int maclen, block_size;
773 Enc *enc = NULL;
774 Mac *mac = NULL;
775 Comp *comp = NULL;
776
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000777 if (newkeys[MODE_IN] != NULL) {
778 enc = &newkeys[MODE_IN]->enc;
779 mac = &newkeys[MODE_IN]->mac;
780 comp = &newkeys[MODE_IN]->comp;
Damien Miller33b13562000-04-04 14:38:59 +1000781 }
782 maclen = mac && mac->enabled ? mac->mac_len : 0;
Damien Miller874d77b2000-10-14 16:23:11 +1100783 block_size = enc ? enc->cipher->block_size : 8;
Damien Miller33b13562000-04-04 14:38:59 +1000784
785 if (packet_length == 0) {
786 /*
787 * check if input size is less than the cipher block size,
788 * decrypt first block and extract length of incoming packet
789 */
790 if (buffer_len(&input) < block_size)
791 return SSH_MSG_NONE;
792 buffer_clear(&incoming_packet);
793 buffer_append_space(&incoming_packet, &cp, block_size);
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000794 cipher_decrypt(&receive_context, cp, buffer_ptr(&input),
Damien Miller33b13562000-04-04 14:38:59 +1000795 block_size);
Ben Lindstrom46c16222000-12-22 01:43:59 +0000796 ucp = (u_char *) buffer_ptr(&incoming_packet);
Damien Miller33b13562000-04-04 14:38:59 +1000797 packet_length = GET_32BIT(ucp);
798 if (packet_length < 1 + 4 || packet_length > 256 * 1024) {
799 buffer_dump(&incoming_packet);
800 packet_disconnect("Bad packet length %d.", packet_length);
801 }
802 DBG(debug("input: packet len %d", packet_length+4));
803 buffer_consume(&input, block_size);
804 }
805 /* we have a partial packet of block_size bytes */
806 need = 4 + packet_length - block_size;
807 DBG(debug("partial packet %d, need %d, maclen %d", block_size,
808 need, maclen));
809 if (need % block_size != 0)
810 fatal("padding error: need %d block %d mod %d",
811 need, block_size, need % block_size);
812 /*
813 * check if the entire packet has been received and
814 * decrypt into incoming_packet
815 */
816 if (buffer_len(&input) < need + maclen)
817 return SSH_MSG_NONE;
818#ifdef PACKET_DEBUG
819 fprintf(stderr, "read_poll enc/full: ");
820 buffer_dump(&input);
821#endif
822 buffer_append_space(&incoming_packet, &cp, need);
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000823 cipher_decrypt(&receive_context, cp, buffer_ptr(&input), need);
Damien Miller33b13562000-04-04 14:38:59 +1000824 buffer_consume(&input, need);
825 /*
826 * compute MAC over seqnr and packet,
827 * increment sequence number for incoming packet
828 */
Damien Miller4af51302000-04-16 11:18:38 +1000829 if (mac && mac->enabled) {
Ben Lindstrom06b33aa2001-02-15 03:01:59 +0000830 macbuf = mac_compute(mac, seqnr,
Ben Lindstrom46c16222000-12-22 01:43:59 +0000831 (u_char *) buffer_ptr(&incoming_packet),
Ben Lindstrom06b33aa2001-02-15 03:01:59 +0000832 buffer_len(&incoming_packet));
Damien Miller33b13562000-04-04 14:38:59 +1000833 if (memcmp(macbuf, buffer_ptr(&input), mac->mac_len) != 0)
Damien Miller874d77b2000-10-14 16:23:11 +1100834 packet_disconnect("Corrupted MAC on input.");
835 DBG(debug("MAC #%d ok", seqnr));
Damien Miller33b13562000-04-04 14:38:59 +1000836 buffer_consume(&input, mac->mac_len);
837 }
Damien Miller4af51302000-04-16 11:18:38 +1000838 if (++seqnr == 0)
839 log("incoming seqnr wraps around");
Damien Miller33b13562000-04-04 14:38:59 +1000840
841 /* get padlen */
842 cp = buffer_ptr(&incoming_packet) + 4;
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000843 padlen = (u_char) *cp;
Damien Miller33b13562000-04-04 14:38:59 +1000844 DBG(debug("input: padlen %d", padlen));
845 if (padlen < 4)
846 packet_disconnect("Corrupted padlen %d on input.", padlen);
847
848 /* skip packet size + padlen, discard padding */
849 buffer_consume(&incoming_packet, 4 + 1);
850 buffer_consume_end(&incoming_packet, padlen);
851
852 DBG(debug("input: len before de-compress %d", buffer_len(&incoming_packet)));
853 if (comp && comp->enabled) {
854 buffer_clear(&compression_buffer);
855 buffer_uncompress(&incoming_packet, &compression_buffer);
856 buffer_clear(&incoming_packet);
857 buffer_append(&incoming_packet, buffer_ptr(&compression_buffer),
858 buffer_len(&compression_buffer));
859 DBG(debug("input: len after de-compress %d", buffer_len(&incoming_packet)));
860 }
861 /*
862 * get packet type, implies consume.
863 * return length of payload (without type field)
864 */
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000865 type = buffer_get_char(&incoming_packet);
Ben Lindstrom2d90e002001-04-04 02:00:54 +0000866 if (type == SSH2_MSG_NEWKEYS)
867 set_newkeys(MODE_IN);
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000868 *payload_len_ptr = buffer_len(&incoming_packet);
Damien Miller33b13562000-04-04 14:38:59 +1000869#ifdef PACKET_DEBUG
Ben Lindstrom204e4882001-03-05 06:47:00 +0000870 fprintf(stderr, "read/plain[%d]:\r\n", type);
Damien Miller33b13562000-04-04 14:38:59 +1000871 buffer_dump(&incoming_packet);
872#endif
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000873 /* reset for next packet */
874 packet_length = 0;
875 return type;
Damien Miller33b13562000-04-04 14:38:59 +1000876}
877
878int
879packet_read_poll(int *payload_len_ptr)
880{
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000881 int reason;
882 u_char type;
Damien Miller33b13562000-04-04 14:38:59 +1000883 char *msg;
Damien Miller33b13562000-04-04 14:38:59 +1000884
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000885 for (;;) {
886 if (compat20) {
887 type = packet_read_poll2(payload_len_ptr);
888 if (type)
Damien Miller33b13562000-04-04 14:38:59 +1000889 DBG(debug("received packet type %d", type));
890 switch(type) {
891 case SSH2_MSG_IGNORE:
892 break;
893 case SSH2_MSG_DEBUG:
894 packet_get_char();
895 msg = packet_get_string(NULL);
896 debug("Remote: %.900s", msg);
897 xfree(msg);
898 msg = packet_get_string(NULL);
899 xfree(msg);
900 break;
901 case SSH2_MSG_DISCONNECT:
902 reason = packet_get_int();
903 msg = packet_get_string(NULL);
Ben Lindstrom5c1fbab2001-01-03 03:51:15 +0000904 log("Received disconnect from %s: %d: %.400s", get_remote_ipaddr(),
905 reason, msg);
Damien Miller33b13562000-04-04 14:38:59 +1000906 xfree(msg);
907 fatal_cleanup();
908 break;
909 default:
910 return type;
911 break;
Kevin Stevesef4eea92001-02-05 12:42:17 +0000912 }
Damien Miller33b13562000-04-04 14:38:59 +1000913 } else {
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000914 type = packet_read_poll1(payload_len_ptr);
Damien Miller33b13562000-04-04 14:38:59 +1000915 switch(type) {
916 case SSH_MSG_IGNORE:
917 break;
918 case SSH_MSG_DEBUG:
919 msg = packet_get_string(NULL);
920 debug("Remote: %.900s", msg);
921 xfree(msg);
922 break;
923 case SSH_MSG_DISCONNECT:
924 msg = packet_get_string(NULL);
Ben Lindstrom5c1fbab2001-01-03 03:51:15 +0000925 log("Received disconnect from %s: %.400s", get_remote_ipaddr(),
926 msg);
Damien Miller33b13562000-04-04 14:38:59 +1000927 fatal_cleanup();
928 xfree(msg);
929 break;
930 default:
Ben Lindstrom80c6d772001-06-05 21:09:18 +0000931 if (type)
Damien Miller33b13562000-04-04 14:38:59 +1000932 DBG(debug("received packet type %d", type));
933 return type;
934 break;
Kevin Stevesef4eea92001-02-05 12:42:17 +0000935 }
Damien Miller33b13562000-04-04 14:38:59 +1000936 }
937 }
938}
939
Damien Miller5428f641999-11-25 11:54:57 +1100940/*
941 * Buffers the given amount of input characters. This is intended to be used
942 * together with packet_read_poll.
943 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000944
945void
Ben Lindstrom46c16222000-12-22 01:43:59 +0000946packet_process_incoming(const char *buf, u_int len)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000947{
Damien Miller95def091999-11-25 00:26:21 +1100948 buffer_append(&input, buf, len);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000949}
950
951/* Returns a character from the packet. */
952
Ben Lindstrom46c16222000-12-22 01:43:59 +0000953u_int
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000954packet_get_char()
955{
Damien Miller95def091999-11-25 00:26:21 +1100956 char ch;
957 buffer_get(&incoming_packet, &ch, 1);
Ben Lindstrom46c16222000-12-22 01:43:59 +0000958 return (u_char) ch;
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000959}
960
961/* Returns an integer from the packet data. */
962
Ben Lindstrom46c16222000-12-22 01:43:59 +0000963u_int
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000964packet_get_int()
965{
Damien Miller95def091999-11-25 00:26:21 +1100966 return buffer_get_int(&incoming_packet);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000967}
968
Damien Miller5428f641999-11-25 11:54:57 +1100969/*
970 * Returns an arbitrary precision integer from the packet data. The integer
971 * must have been initialized before this call.
972 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000973
974void
Damien Miller95def091999-11-25 00:26:21 +1100975packet_get_bignum(BIGNUM * value, int *length_ptr)
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000976{
Damien Miller95def091999-11-25 00:26:21 +1100977 *length_ptr = buffer_get_bignum(&incoming_packet, value);
Damien Millerd4a8b7e1999-10-27 13:42:43 +1000978}
979
Damien Miller33b13562000-04-04 14:38:59 +1000980void
981packet_get_bignum2(BIGNUM * value, int *length_ptr)
982{
983 *length_ptr = buffer_get_bignum2(&incoming_packet, value);
984}
985
986char *
987packet_get_raw(int *length_ptr)
988{
989 int bytes = buffer_len(&incoming_packet);
990 if (length_ptr != NULL)
991 *length_ptr = bytes;
992 return buffer_ptr(&incoming_packet);
993}
994
Damien Miller4af51302000-04-16 11:18:38 +1000995int
996packet_remaining(void)
997{
998 return buffer_len(&incoming_packet);
999}
1000
Damien Miller5428f641999-11-25 11:54:57 +11001001/*
1002 * Returns a string from the packet data. The string is allocated using
1003 * xmalloc; it is the responsibility of the calling program to free it when
1004 * no longer needed. The length_ptr argument may be NULL, or point to an
1005 * integer into which the length of the string is stored.
1006 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001007
Damien Miller5428f641999-11-25 11:54:57 +11001008char *
Ben Lindstrom46c16222000-12-22 01:43:59 +00001009packet_get_string(u_int *length_ptr)
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001010{
Damien Miller95def091999-11-25 00:26:21 +11001011 return buffer_get_string(&incoming_packet, length_ptr);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001012}
1013
Damien Miller5428f641999-11-25 11:54:57 +11001014/*
1015 * Sends a diagnostic message from the server to the client. This message
1016 * can be sent at any time (but not while constructing another message). The
1017 * message is printed immediately, but only if the client is being executed
1018 * in verbose mode. These messages are primarily intended to ease debugging
1019 * authentication problems. The length of the formatted message must not
1020 * exceed 1024 bytes. This will automatically call packet_write_wait.
1021 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001022
1023void
Damien Miller95def091999-11-25 00:26:21 +11001024packet_send_debug(const char *fmt,...)
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001025{
Damien Miller95def091999-11-25 00:26:21 +11001026 char buf[1024];
1027 va_list args;
1028
Ben Lindstroma14ee472000-12-07 01:24:58 +00001029 if (compat20 && (datafellows & SSH_BUG_DEBUG))
1030 return;
1031
Damien Miller95def091999-11-25 00:26:21 +11001032 va_start(args, fmt);
1033 vsnprintf(buf, sizeof(buf), fmt, args);
1034 va_end(args);
1035
Damien Miller7c8af4f2000-05-01 08:24:07 +10001036 if (compat20) {
1037 packet_start(SSH2_MSG_DEBUG);
1038 packet_put_char(0); /* bool: always display */
1039 packet_put_cstring(buf);
1040 packet_put_cstring("");
1041 } else {
1042 packet_start(SSH_MSG_DEBUG);
1043 packet_put_cstring(buf);
1044 }
Damien Miller95def091999-11-25 00:26:21 +11001045 packet_send();
1046 packet_write_wait();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001047}
1048
Damien Miller5428f641999-11-25 11:54:57 +11001049/*
1050 * Logs the error plus constructs and sends a disconnect packet, closes the
1051 * connection, and exits. This function never returns. The error message
1052 * should not contain a newline. The length of the formatted message must
1053 * not exceed 1024 bytes.
1054 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001055
1056void
Damien Miller95def091999-11-25 00:26:21 +11001057packet_disconnect(const char *fmt,...)
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001058{
Damien Miller95def091999-11-25 00:26:21 +11001059 char buf[1024];
1060 va_list args;
1061 static int disconnecting = 0;
1062 if (disconnecting) /* Guard against recursive invocations. */
1063 fatal("packet_disconnect called recursively.");
1064 disconnecting = 1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001065
Damien Miller5428f641999-11-25 11:54:57 +11001066 /*
1067 * Format the message. Note that the caller must make sure the
1068 * message is of limited size.
1069 */
Damien Miller95def091999-11-25 00:26:21 +11001070 va_start(args, fmt);
1071 vsnprintf(buf, sizeof(buf), fmt, args);
1072 va_end(args);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001073
Damien Miller95def091999-11-25 00:26:21 +11001074 /* Send the disconnect message to the other side, and wait for it to get sent. */
Damien Miller33b13562000-04-04 14:38:59 +10001075 if (compat20) {
1076 packet_start(SSH2_MSG_DISCONNECT);
1077 packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR);
1078 packet_put_cstring(buf);
1079 packet_put_cstring("");
1080 } else {
1081 packet_start(SSH_MSG_DISCONNECT);
Ben Lindstrom664408d2001-06-09 01:42:01 +00001082 packet_put_cstring(buf);
Damien Miller33b13562000-04-04 14:38:59 +10001083 }
Damien Miller95def091999-11-25 00:26:21 +11001084 packet_send();
1085 packet_write_wait();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001086
Damien Miller95def091999-11-25 00:26:21 +11001087 /* Stop listening for connections. */
Ben Lindstrom601e4362001-06-21 03:19:23 +00001088 channel_close_all();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001089
Damien Miller95def091999-11-25 00:26:21 +11001090 /* Close the connection. */
1091 packet_close();
1092
1093 /* Display the error locally and exit. */
Damien Milleraae6c611999-12-06 11:47:28 +11001094 log("Disconnecting: %.100s", buf);
1095 fatal_cleanup();
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001096}
1097
Damien Miller5428f641999-11-25 11:54:57 +11001098/* Checks if there is any buffered output, and tries to write some of the output. */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001099
1100void
1101packet_write_poll()
1102{
Damien Miller95def091999-11-25 00:26:21 +11001103 int len = buffer_len(&output);
1104 if (len > 0) {
1105 len = write(connection_out, buffer_ptr(&output), len);
1106 if (len <= 0) {
1107 if (errno == EAGAIN)
1108 return;
1109 else
1110 fatal("Write failed: %.100s", strerror(errno));
1111 }
1112 buffer_consume(&output, len);
1113 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001114}
1115
Damien Miller5428f641999-11-25 11:54:57 +11001116/*
1117 * Calls packet_write_poll repeatedly until all pending output data has been
1118 * written.
1119 */
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001120
1121void
1122packet_write_wait()
1123{
Ben Lindstromcb978aa2001-03-05 07:07:49 +00001124 fd_set *setp;
1125
1126 setp = (fd_set *)xmalloc(howmany(connection_out + 1, NFDBITS) *
1127 sizeof(fd_mask));
Damien Miller95def091999-11-25 00:26:21 +11001128 packet_write_poll();
1129 while (packet_have_data_to_write()) {
Ben Lindstromcb978aa2001-03-05 07:07:49 +00001130 memset(setp, 0, howmany(connection_out + 1, NFDBITS) *
1131 sizeof(fd_mask));
1132 FD_SET(connection_out, setp);
1133 while (select(connection_out + 1, NULL, setp, NULL, NULL) == -1 &&
Ben Lindstromf9452512001-02-15 03:12:08 +00001134 (errno == EAGAIN || errno == EINTR))
1135 ;
Damien Miller95def091999-11-25 00:26:21 +11001136 packet_write_poll();
1137 }
Ben Lindstromcb978aa2001-03-05 07:07:49 +00001138 xfree(setp);
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001139}
1140
1141/* Returns true if there is buffered data to write to the connection. */
1142
1143int
1144packet_have_data_to_write()
1145{
Damien Miller95def091999-11-25 00:26:21 +11001146 return buffer_len(&output) != 0;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001147}
1148
1149/* Returns true if there is not too much data to write to the connection. */
1150
1151int
1152packet_not_very_much_data_to_write()
1153{
Damien Miller95def091999-11-25 00:26:21 +11001154 if (interactive_mode)
1155 return buffer_len(&output) < 16384;
1156 else
1157 return buffer_len(&output) < 128 * 1024;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001158}
1159
1160/* Informs that the current session is interactive. Sets IP flags for that. */
1161
1162void
Ben Lindstrombf555ba2001-01-18 02:04:35 +00001163packet_set_interactive(int interactive)
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001164{
Ben Lindstrombf555ba2001-01-18 02:04:35 +00001165 static int called = 0;
Damien Miller0bcf9ea2001-02-27 14:03:30 +11001166#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN)
Ben Lindstrombf555ba2001-01-18 02:04:35 +00001167 int lowdelay = IPTOS_LOWDELAY;
1168 int throughput = IPTOS_THROUGHPUT;
Damien Miller0bcf9ea2001-02-27 14:03:30 +11001169#endif
Damien Miller95def091999-11-25 00:26:21 +11001170 int on = 1;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001171
Ben Lindstrombf555ba2001-01-18 02:04:35 +00001172 if (called)
1173 return;
1174 called = 1;
1175
Damien Miller95def091999-11-25 00:26:21 +11001176 /* Record that we are in interactive mode. */
1177 interactive_mode = interactive;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001178
Damien Miller34132e52000-01-14 15:45:46 +11001179 /* Only set socket options if using a socket. */
1180 if (!packet_connection_is_on_socket())
Damien Miller95def091999-11-25 00:26:21 +11001181 return;
Damien Miller34132e52000-01-14 15:45:46 +11001182 /*
Ben Lindstrom2f959b42001-01-11 06:20:23 +00001183 * IPTOS_LOWDELAY and IPTOS_THROUGHPUT are IPv4 only
Damien Miller34132e52000-01-14 15:45:46 +11001184 */
Damien Miller95def091999-11-25 00:26:21 +11001185 if (interactive) {
Damien Miller5428f641999-11-25 11:54:57 +11001186 /*
1187 * Set IP options for an interactive connection. Use
1188 * IPTOS_LOWDELAY and TCP_NODELAY.
1189 */
Damien Miller2ae714f2000-07-11 09:29:50 +10001190#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN)
Ben Lindstrom2f959b42001-01-11 06:20:23 +00001191 if (packet_connection_is_ipv4()) {
Kevin Steves0c696152001-01-24 13:47:43 +00001192 if (setsockopt(connection_in, IPPROTO_IP, IP_TOS,
Ben Lindstrom2f959b42001-01-11 06:20:23 +00001193 (void *) &lowdelay, sizeof(lowdelay)) < 0)
Kevin Steves0c696152001-01-24 13:47:43 +00001194 error("setsockopt IPTOS_LOWDELAY: %.100s",
Ben Lindstrom2f959b42001-01-11 06:20:23 +00001195 strerror(errno));
1196 }
Damien Miller615f9392000-05-17 22:53:33 +10001197#endif
Damien Miller95def091999-11-25 00:26:21 +11001198 if (setsockopt(connection_in, IPPROTO_TCP, TCP_NODELAY, (void *) &on,
Damien Miller34132e52000-01-14 15:45:46 +11001199 sizeof(on)) < 0)
Damien Miller95def091999-11-25 00:26:21 +11001200 error("setsockopt TCP_NODELAY: %.100s", strerror(errno));
Ben Lindstrom2f959b42001-01-11 06:20:23 +00001201 } else if (packet_connection_is_ipv4()) {
Damien Miller5428f641999-11-25 11:54:57 +11001202 /*
1203 * Set IP options for a non-interactive connection. Use
1204 * IPTOS_THROUGHPUT.
1205 */
Damien Miller2ae714f2000-07-11 09:29:50 +10001206#if defined(IP_TOS) && !defined(IP_TOS_IS_BROKEN)
Damien Miller95def091999-11-25 00:26:21 +11001207 if (setsockopt(connection_in, IPPROTO_IP, IP_TOS, (void *) &throughput,
Damien Miller34132e52000-01-14 15:45:46 +11001208 sizeof(throughput)) < 0)
Damien Miller95def091999-11-25 00:26:21 +11001209 error("setsockopt IPTOS_THROUGHPUT: %.100s", strerror(errno));
Damien Miller615f9392000-05-17 22:53:33 +10001210#endif
Damien Miller95def091999-11-25 00:26:21 +11001211 }
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001212}
1213
1214/* Returns true if the current connection is interactive. */
1215
1216int
1217packet_is_interactive()
1218{
Damien Miller95def091999-11-25 00:26:21 +11001219 return interactive_mode;
Damien Millerd4a8b7e1999-10-27 13:42:43 +10001220}
Damien Miller6162d121999-11-21 13:23:52 +11001221
1222int
1223packet_set_maxsize(int s)
1224{
Damien Miller95def091999-11-25 00:26:21 +11001225 static int called = 0;
1226 if (called) {
Damien Miller33b13562000-04-04 14:38:59 +10001227 log("packet_set_maxsize: called twice: old %d new %d",
1228 max_packet_size, s);
Damien Miller95def091999-11-25 00:26:21 +11001229 return -1;
1230 }
1231 if (s < 4 * 1024 || s > 1024 * 1024) {
1232 log("packet_set_maxsize: bad size %d", s);
1233 return -1;
1234 }
Ben Lindstrom16d45b32001-06-13 04:39:18 +00001235 debug("packet_set_maxsize: setting to %d", s);
Damien Miller95def091999-11-25 00:26:21 +11001236 max_packet_size = s;
1237 return s;
Damien Miller6162d121999-11-21 13:23:52 +11001238}
Ben Lindstrom5699c5f2001-03-05 06:17:49 +00001239
1240/*
1241 * 9.2. Ignored Data Message
Ben Lindstroma3700052001-04-05 23:26:32 +00001242 *
Ben Lindstrom5699c5f2001-03-05 06:17:49 +00001243 * byte SSH_MSG_IGNORE
1244 * string data
Ben Lindstroma3700052001-04-05 23:26:32 +00001245 *
Ben Lindstrom5699c5f2001-03-05 06:17:49 +00001246 * All implementations MUST understand (and ignore) this message at any
1247 * time (after receiving the protocol version). No implementation is
1248 * required to send them. This message can be used as an additional
1249 * protection measure against advanced traffic analysis techniques.
1250 */
1251/* size of current + ignore message should be n*sumlen bytes (w/o mac) */
1252void
1253packet_inject_ignore(int sumlen)
1254{
Ben Lindstrome229b252001-03-05 06:28:06 +00001255 int blocksize, padlen, have, need, nb, mini, nbytes;
Ben Lindstrom5699c5f2001-03-05 06:17:49 +00001256 Enc *enc = NULL;
1257
Ben Lindstrom80c6d772001-06-05 21:09:18 +00001258 if (compat20 == 0)
Ben Lindstrom5699c5f2001-03-05 06:17:49 +00001259 return;
1260
1261 have = buffer_len(&outgoing_packet);
1262 debug2("packet_inject_ignore: current %d", have);
Ben Lindstrom2d90e002001-04-04 02:00:54 +00001263 if (newkeys[MODE_OUT] != NULL)
1264 enc = &newkeys[MODE_OUT]->enc;
Ben Lindstrom5699c5f2001-03-05 06:17:49 +00001265 blocksize = enc ? enc->cipher->block_size : 8;
1266 padlen = blocksize - (have % blocksize);
1267 if (padlen < 4)
1268 padlen += blocksize;
1269 have += padlen;
1270 have /= blocksize; /* # of blocks for current message */
1271
1272 nb = roundup(sumlen, blocksize) / blocksize; /* blocks for both */
1273 mini = roundup(5+1+4+4, blocksize) / blocksize; /* minsize ignore msg */
1274 need = nb - (have % nb); /* blocks for ignore */
1275 if (need <= mini)
1276 need += nb;
1277 nbytes = (need - mini) * blocksize; /* size of ignore payload */
1278 debug2("packet_inject_ignore: block %d have %d nb %d mini %d need %d",
1279 blocksize, have, nb, mini, need);
1280
1281 /* enqueue current message and append a ignore message */
1282 packet_send();
Ben Lindstrome229b252001-03-05 06:28:06 +00001283 packet_send_ignore(nbytes);
1284}
1285
1286void
1287packet_send_ignore(int nbytes)
1288{
1289 u_int32_t rand = 0;
1290 int i;
1291
1292 packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE);
Ben Lindstrom5699c5f2001-03-05 06:17:49 +00001293 packet_put_int(nbytes);
1294 for(i = 0; i < nbytes; i++) {
1295 if (i % 4 == 0)
1296 rand = arc4random();
1297 packet_put_char(rand & 0xff);
1298 rand >>= 8;
1299 }
1300}