1 /* $OpenBSD: packet.c,v 1.173 2011/05/06 21:14:05 djm Exp $ */
4 * Author: Tatu Ylonen <ylo@cs.hut.fi>
5 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
7 * This file contains code implementing the packet protocol and communication
8 * with the other side. This same code is used both on client and server side.
10 * As far as I am concerned, the code I have written for this software
11 * can be used freely for any purpose. Any derived versions of this
12 * software must be clearly marked as such, and if the derived work is
13 * incompatible with the protocol description in the RFC file, it must be
14 * called by a name other than "ssh" or "Secure Shell".
17 * SSH2 packet format added by Markus Friedl.
18 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
20 * Redistribution and use in source and binary forms, with or without
21 * modification, are permitted provided that the following conditions
23 * 1. Redistributions of source code must retain the above copyright
24 * notice, this list of conditions and the following disclaimer.
25 * 2. Redistributions in binary form must reproduce the above copyright
26 * notice, this list of conditions and the following disclaimer in the
27 * documentation and/or other materials provided with the distribution.
29 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
30 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
31 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
32 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
33 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
34 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
35 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
36 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
37 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
38 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
43 #include <sys/types.h>
44 #include "openbsd-compat/sys-queue.h"
45 #include <sys/param.h>
46 #include <sys/socket.h>
47 #ifdef HAVE_SYS_TIME_H
48 # include <sys/time.h>
51 #include <netinet/in.h>
52 #include <netinet/ip.h>
53 #include <arpa/inet.h>
89 #define PACKET_MAX_SIZE (256 * 1024)
99 TAILQ_ENTRY(packet) next;
104 struct session_state {
106 * This variable contains the file descriptors used for
107 * communicating with the other side. connection_in is used for
108 * reading; connection_out for writing. These can be the same
109 * descriptor, in which case it is assumed to be a socket.
114 /* Protocol flags for the remote side. */
115 u_int remote_protocol_flags;
117 /* Encryption context for receiving data. Only used for decryption. */
118 CipherContext receive_context;
120 /* Encryption context for sending data. Only used for encryption. */
121 CipherContext send_context;
123 /* Buffer for raw input data from the socket. */
126 /* Buffer for raw output data going to the socket. */
129 /* Buffer for the partial outgoing packet being constructed. */
130 Buffer outgoing_packet;
132 /* Buffer for the incoming packet currently being processed. */
133 Buffer incoming_packet;
135 /* Scratch buffer for packet compression/decompression. */
136 Buffer compression_buffer;
137 int compression_buffer_ready;
140 * Flag indicating whether packet compression/decompression is
143 int packet_compression;
145 /* default maximum packet size */
146 u_int max_packet_size;
148 /* Flag indicating whether this module has been initialized. */
151 /* Set to true if the connection is interactive. */
152 int interactive_mode;
154 /* Set to true if we are the server side. */
157 /* Set to true if we are authenticated. */
158 int after_authentication;
160 int keep_alive_timeouts;
162 /* The maximum time that we will wait to send or receive a packet */
163 int packet_timeout_ms;
165 /* Session key information for Encryption and MAC */
166 Newkeys *newkeys[MODE_MAX];
167 struct packet_state p_read, p_send;
169 u_int64_t max_blocks_in, max_blocks_out;
170 u_int32_t rekey_limit;
172 /* Session key for protocol v1 */
173 u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
176 /* roundup current message to extra_pad bytes */
179 /* XXX discard incoming data after MAC error */
180 u_int packet_discard;
181 Mac *packet_discard_mac;
183 /* Used in packet_read_poll2() */
186 /* Used in packet_send2 */
189 /* Used in packet_set_interactive */
190 int set_interactive_called;
192 /* Used in packet_set_maxsize */
193 int set_maxsize_called;
195 TAILQ_HEAD(, packet) outgoing;
198 static struct session_state *active_state, *backup_state;
199 #ifdef NONE_CIPHER_ENABLED
200 static int rekey_requested = 0;
203 static struct session_state *
204 alloc_session_state(void)
206 struct session_state *s = xcalloc(1, sizeof(*s));
208 s->connection_in = -1;
209 s->connection_out = -1;
210 s->max_packet_size = 32768;
211 s->packet_timeout_ms = -1;
216 * Sets the descriptors used for communication. Disables encryption until
217 * packet_set_encryption_key is called.
220 packet_set_connection(int fd_in, int fd_out)
222 Cipher *none = cipher_by_name("none");
225 fatal("packet_set_connection: cannot load cipher 'none'");
226 if (active_state == NULL)
227 active_state = alloc_session_state();
228 active_state->connection_in = fd_in;
229 active_state->connection_out = fd_out;
230 cipher_init(&active_state->send_context, none, (const u_char *)"",
231 0, NULL, 0, CIPHER_ENCRYPT);
232 cipher_init(&active_state->receive_context, none, (const u_char *)"",
233 0, NULL, 0, CIPHER_DECRYPT);
234 active_state->newkeys[MODE_IN] = active_state->newkeys[MODE_OUT] = NULL;
235 if (!active_state->initialized) {
236 active_state->initialized = 1;
237 buffer_init(&active_state->input);
238 buffer_init(&active_state->output);
239 buffer_init(&active_state->outgoing_packet);
240 buffer_init(&active_state->incoming_packet);
241 TAILQ_INIT(&active_state->outgoing);
242 active_state->p_send.packets = active_state->p_read.packets = 0;
247 packet_set_timeout(int timeout, int count)
249 if (timeout == 0 || count == 0) {
250 active_state->packet_timeout_ms = -1;
253 if ((INT_MAX / 1000) / count < timeout)
254 active_state->packet_timeout_ms = INT_MAX;
256 active_state->packet_timeout_ms = timeout * count * 1000;
260 packet_stop_discard(void)
262 if (active_state->packet_discard_mac) {
265 memset(buf, 'a', sizeof(buf));
266 while (buffer_len(&active_state->incoming_packet) <
268 buffer_append(&active_state->incoming_packet, buf,
270 (void) mac_compute(active_state->packet_discard_mac,
271 active_state->p_read.seqnr,
272 buffer_ptr(&active_state->incoming_packet),
275 logit("Finished discarding for %.200s", get_remote_ipaddr());
280 packet_start_discard(Enc *enc, Mac *mac, u_int packet_length, u_int discard)
282 if (enc == NULL || !cipher_is_cbc(enc->cipher))
283 packet_disconnect("Packet corrupt");
284 if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled)
285 active_state->packet_discard_mac = mac;
286 if (buffer_len(&active_state->input) >= discard)
287 packet_stop_discard();
288 active_state->packet_discard = discard -
289 buffer_len(&active_state->input);
292 /* Returns 1 if remote host is connected via socket, 0 if not. */
295 packet_connection_is_on_socket(void)
297 struct sockaddr_storage from, to;
298 socklen_t fromlen, tolen;
300 /* filedescriptors in and out are the same, so it's a socket */
301 if (active_state->connection_in == active_state->connection_out)
303 fromlen = sizeof(from);
304 memset(&from, 0, sizeof(from));
305 if (getpeername(active_state->connection_in, (struct sockaddr *)&from,
309 memset(&to, 0, sizeof(to));
310 if (getpeername(active_state->connection_out, (struct sockaddr *)&to,
313 if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
315 if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
321 * Exports an IV from the CipherContext required to export the key
322 * state back from the unprivileged child to the privileged parent
327 packet_get_keyiv(int mode, u_char *iv, u_int len)
331 if (mode == MODE_OUT)
332 cc = &active_state->send_context;
334 cc = &active_state->receive_context;
336 cipher_get_keyiv(cc, iv, len);
340 packet_get_keycontext(int mode, u_char *dat)
344 if (mode == MODE_OUT)
345 cc = &active_state->send_context;
347 cc = &active_state->receive_context;
349 return (cipher_get_keycontext(cc, dat));
353 packet_set_keycontext(int mode, u_char *dat)
357 if (mode == MODE_OUT)
358 cc = &active_state->send_context;
360 cc = &active_state->receive_context;
362 cipher_set_keycontext(cc, dat);
366 packet_get_keyiv_len(int mode)
370 if (mode == MODE_OUT)
371 cc = &active_state->send_context;
373 cc = &active_state->receive_context;
375 return (cipher_get_keyiv_len(cc));
379 packet_set_iv(int mode, u_char *dat)
383 if (mode == MODE_OUT)
384 cc = &active_state->send_context;
386 cc = &active_state->receive_context;
388 cipher_set_keyiv(cc, dat);
392 packet_get_ssh1_cipher(void)
394 return (cipher_get_number(active_state->receive_context.cipher));
398 packet_get_state(int mode, u_int32_t *seqnr, u_int64_t *blocks,
399 u_int32_t *packets, u_int64_t *bytes)
401 struct packet_state *state;
403 state = (mode == MODE_IN) ?
404 &active_state->p_read : &active_state->p_send;
406 *seqnr = state->seqnr;
408 *blocks = state->blocks;
410 *packets = state->packets;
412 *bytes = state->bytes;
416 packet_set_state(int mode, u_int32_t seqnr, u_int64_t blocks, u_int32_t packets,
419 struct packet_state *state;
421 state = (mode == MODE_IN) ?
422 &active_state->p_read : &active_state->p_send;
423 state->seqnr = seqnr;
424 state->blocks = blocks;
425 state->packets = packets;
426 state->bytes = bytes;
430 packet_connection_af(void)
432 struct sockaddr_storage to;
433 socklen_t tolen = sizeof(to);
435 memset(&to, 0, sizeof(to));
436 if (getsockname(active_state->connection_out, (struct sockaddr *)&to,
439 if (to.ss_family == AF_INET)
442 if (to.ss_family == AF_INET6 &&
443 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr))
449 /* Sets the connection into non-blocking mode. */
452 packet_set_nonblocking(void)
454 /* Set the socket into non-blocking mode. */
455 set_nonblock(active_state->connection_in);
457 if (active_state->connection_out != active_state->connection_in)
458 set_nonblock(active_state->connection_out);
461 /* Returns the socket used for reading. */
464 packet_get_connection_in(void)
466 return active_state->connection_in;
469 /* Returns the descriptor used for writing. */
472 packet_get_connection_out(void)
474 return active_state->connection_out;
477 /* Closes the connection and clears and frees internal data structures. */
482 if (!active_state->initialized)
484 active_state->initialized = 0;
485 if (active_state->connection_in == active_state->connection_out) {
486 shutdown(active_state->connection_out, SHUT_RDWR);
487 close(active_state->connection_out);
489 close(active_state->connection_in);
490 close(active_state->connection_out);
492 buffer_free(&active_state->input);
493 buffer_free(&active_state->output);
494 buffer_free(&active_state->outgoing_packet);
495 buffer_free(&active_state->incoming_packet);
496 if (active_state->compression_buffer_ready) {
497 buffer_free(&active_state->compression_buffer);
498 buffer_compress_uninit();
500 cipher_cleanup(&active_state->send_context);
501 cipher_cleanup(&active_state->receive_context);
504 /* Sets remote side protocol flags. */
507 packet_set_protocol_flags(u_int protocol_flags)
509 active_state->remote_protocol_flags = protocol_flags;
512 /* Returns the remote protocol flags set earlier by the above function. */
515 packet_get_protocol_flags(void)
517 return active_state->remote_protocol_flags;
521 * Starts packet compression from the next packet on in both directions.
522 * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
526 packet_init_compression(void)
528 if (active_state->compression_buffer_ready == 1)
530 active_state->compression_buffer_ready = 1;
531 buffer_init(&active_state->compression_buffer);
535 packet_start_compression(int level)
537 if (active_state->packet_compression && !compat20)
538 fatal("Compression already enabled.");
539 active_state->packet_compression = 1;
540 packet_init_compression();
541 buffer_compress_init_send(level);
542 buffer_compress_init_recv();
546 * Causes any further packets to be encrypted using the given key. The same
547 * key is used for both sending and reception. However, both directions are
548 * encrypted independently of each other.
552 packet_set_encryption_key(const u_char *key, u_int keylen, int number)
554 Cipher *cipher = cipher_by_number(number);
557 fatal("packet_set_encryption_key: unknown cipher number %d", number);
559 fatal("packet_set_encryption_key: keylen too small: %d", keylen);
560 if (keylen > SSH_SESSION_KEY_LENGTH)
561 fatal("packet_set_encryption_key: keylen too big: %d", keylen);
562 memcpy(active_state->ssh1_key, key, keylen);
563 active_state->ssh1_keylen = keylen;
564 cipher_init(&active_state->send_context, cipher, key, keylen, NULL,
566 cipher_init(&active_state->receive_context, cipher, key, keylen, NULL,
571 packet_get_encryption_key(u_char *key)
574 return (active_state->ssh1_keylen);
575 memcpy(key, active_state->ssh1_key, active_state->ssh1_keylen);
576 return (active_state->ssh1_keylen);
579 /* Start constructing a packet to send. */
581 packet_start(u_char type)
586 DBG(debug("packet_start[%d]", type));
587 len = compat20 ? 6 : 9;
588 memset(buf, 0, len - 1);
590 buffer_clear(&active_state->outgoing_packet);
591 buffer_append(&active_state->outgoing_packet, buf, len);
594 /* Append payload. */
596 packet_put_char(int value)
600 buffer_append(&active_state->outgoing_packet, &ch, 1);
604 packet_put_int(u_int value)
606 buffer_put_int(&active_state->outgoing_packet, value);
610 packet_put_int64(u_int64_t value)
612 buffer_put_int64(&active_state->outgoing_packet, value);
616 packet_put_string(const void *buf, u_int len)
618 buffer_put_string(&active_state->outgoing_packet, buf, len);
622 packet_put_cstring(const char *str)
624 buffer_put_cstring(&active_state->outgoing_packet, str);
628 packet_put_raw(const void *buf, u_int len)
630 buffer_append(&active_state->outgoing_packet, buf, len);
634 packet_put_bignum(BIGNUM * value)
636 buffer_put_bignum(&active_state->outgoing_packet, value);
640 packet_put_bignum2(BIGNUM * value)
642 buffer_put_bignum2(&active_state->outgoing_packet, value);
645 #ifdef OPENSSL_HAS_ECC
647 packet_put_ecpoint(const EC_GROUP *curve, const EC_POINT *point)
649 buffer_put_ecpoint(&active_state->outgoing_packet, curve, point);
654 * Finalizes and sends the packet. If the encryption key has been set,
655 * encrypts the packet before sending.
667 * If using packet compression, compress the payload of the outgoing
670 if (active_state->packet_compression) {
671 buffer_clear(&active_state->compression_buffer);
673 buffer_consume(&active_state->outgoing_packet, 8);
675 buffer_append(&active_state->compression_buffer,
676 "\0\0\0\0\0\0\0\0", 8);
677 buffer_compress(&active_state->outgoing_packet,
678 &active_state->compression_buffer);
679 buffer_clear(&active_state->outgoing_packet);
680 buffer_append(&active_state->outgoing_packet,
681 buffer_ptr(&active_state->compression_buffer),
682 buffer_len(&active_state->compression_buffer));
684 /* Compute packet length without padding (add checksum, remove padding). */
685 len = buffer_len(&active_state->outgoing_packet) + 4 - 8;
687 /* Insert padding. Initialized to zero in packet_start1() */
688 padding = 8 - len % 8;
689 if (!active_state->send_context.plaintext) {
690 cp = buffer_ptr(&active_state->outgoing_packet);
691 for (i = 0; i < padding; i++) {
694 cp[7 - i] = rnd & 0xff;
698 buffer_consume(&active_state->outgoing_packet, 8 - padding);
700 /* Add check bytes. */
701 checksum = ssh_crc32(buffer_ptr(&active_state->outgoing_packet),
702 buffer_len(&active_state->outgoing_packet));
703 put_u32(buf, checksum);
704 buffer_append(&active_state->outgoing_packet, buf, 4);
707 fprintf(stderr, "packet_send plain: ");
708 buffer_dump(&active_state->outgoing_packet);
711 /* Append to output. */
713 buffer_append(&active_state->output, buf, 4);
714 cp = buffer_append_space(&active_state->output,
715 buffer_len(&active_state->outgoing_packet));
716 cipher_crypt(&active_state->send_context, cp,
717 buffer_ptr(&active_state->outgoing_packet),
718 buffer_len(&active_state->outgoing_packet));
721 fprintf(stderr, "encrypted: ");
722 buffer_dump(&active_state->output);
724 active_state->p_send.packets++;
725 active_state->p_send.bytes += len +
726 buffer_len(&active_state->outgoing_packet);
727 buffer_clear(&active_state->outgoing_packet);
730 * Note that the packet is now only buffered in output. It won't be
731 * actually sent until packet_write_wait or packet_write_poll is
737 set_newkeys(int mode)
743 u_int64_t *max_blocks;
746 debug2("set_newkeys: mode %d", mode);
748 if (mode == MODE_OUT) {
749 cc = &active_state->send_context;
750 crypt_type = CIPHER_ENCRYPT;
751 active_state->p_send.packets = active_state->p_send.blocks = 0;
752 max_blocks = &active_state->max_blocks_out;
754 cc = &active_state->receive_context;
755 crypt_type = CIPHER_DECRYPT;
756 active_state->p_read.packets = active_state->p_read.blocks = 0;
757 max_blocks = &active_state->max_blocks_in;
759 if (active_state->newkeys[mode] != NULL) {
760 debug("set_newkeys: rekeying");
762 enc = &active_state->newkeys[mode]->enc;
763 mac = &active_state->newkeys[mode]->mac;
764 comp = &active_state->newkeys[mode]->comp;
772 xfree(active_state->newkeys[mode]);
774 active_state->newkeys[mode] = kex_get_newkeys(mode);
775 if (active_state->newkeys[mode] == NULL)
776 fatal("newkeys: no keys for mode %d", mode);
777 enc = &active_state->newkeys[mode]->enc;
778 mac = &active_state->newkeys[mode]->mac;
779 comp = &active_state->newkeys[mode]->comp;
780 if (mac_init(mac) == 0)
782 DBG(debug("cipher_init_context: %d", mode));
783 cipher_init(cc, enc->cipher, enc->key, enc->key_len,
784 enc->iv, enc->block_size, crypt_type);
785 /* Deleting the keys does not gain extra security */
786 /* memset(enc->iv, 0, enc->block_size);
787 memset(enc->key, 0, enc->key_len);
788 memset(mac->key, 0, mac->key_len); */
789 if ((comp->type == COMP_ZLIB ||
790 (comp->type == COMP_DELAYED &&
791 active_state->after_authentication)) && comp->enabled == 0) {
792 packet_init_compression();
793 if (mode == MODE_OUT)
794 buffer_compress_init_send(6);
796 buffer_compress_init_recv();
800 * The 2^(blocksize*2) limit is too expensive for 3DES,
801 * blowfish, etc, so enforce a 1GB limit for small blocksizes.
803 if (enc->block_size >= 16)
804 *max_blocks = (u_int64_t)1 << (enc->block_size*2);
806 *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
807 if (active_state->rekey_limit)
808 *max_blocks = MIN(*max_blocks,
809 active_state->rekey_limit / enc->block_size);
813 * Delayed compression for SSH2 is enabled after authentication:
814 * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
815 * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
818 packet_enable_delayed_compress(void)
824 * Remember that we are past the authentication step, so rekeying
825 * with COMP_DELAYED will turn on compression immediately.
827 active_state->after_authentication = 1;
828 for (mode = 0; mode < MODE_MAX; mode++) {
829 /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
830 if (active_state->newkeys[mode] == NULL)
832 comp = &active_state->newkeys[mode]->comp;
833 if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
834 packet_init_compression();
835 if (mode == MODE_OUT)
836 buffer_compress_init_send(6);
838 buffer_compress_init_recv();
845 * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
848 packet_send2_wrapped(void)
850 u_char type, *cp, *macbuf = NULL;
852 u_int packet_length = 0;
860 if (active_state->newkeys[MODE_OUT] != NULL) {
861 enc = &active_state->newkeys[MODE_OUT]->enc;
862 mac = &active_state->newkeys[MODE_OUT]->mac;
863 comp = &active_state->newkeys[MODE_OUT]->comp;
865 block_size = enc ? enc->block_size : 8;
867 cp = buffer_ptr(&active_state->outgoing_packet);
871 fprintf(stderr, "plain: ");
872 buffer_dump(&active_state->outgoing_packet);
875 if (comp && comp->enabled) {
876 len = buffer_len(&active_state->outgoing_packet);
877 /* skip header, compress only payload */
878 buffer_consume(&active_state->outgoing_packet, 5);
879 buffer_clear(&active_state->compression_buffer);
880 buffer_compress(&active_state->outgoing_packet,
881 &active_state->compression_buffer);
882 buffer_clear(&active_state->outgoing_packet);
883 buffer_append(&active_state->outgoing_packet, "\0\0\0\0\0", 5);
884 buffer_append(&active_state->outgoing_packet,
885 buffer_ptr(&active_state->compression_buffer),
886 buffer_len(&active_state->compression_buffer));
887 DBG(debug("compression: raw %d compressed %d", len,
888 buffer_len(&active_state->outgoing_packet)));
891 /* sizeof (packet_len + pad_len + payload) */
892 len = buffer_len(&active_state->outgoing_packet);
895 * calc size of padding, alloc space, get random data,
896 * minimum padding is 4 bytes
898 padlen = block_size - (len % block_size);
900 padlen += block_size;
901 if (active_state->extra_pad) {
902 /* will wrap if extra_pad+padlen > 255 */
903 active_state->extra_pad =
904 roundup(active_state->extra_pad, block_size);
905 pad = active_state->extra_pad -
906 ((len + padlen) % active_state->extra_pad);
907 debug3("packet_send2: adding %d (len %d padlen %d extra_pad %d)",
908 pad, len, padlen, active_state->extra_pad);
910 active_state->extra_pad = 0;
912 cp = buffer_append_space(&active_state->outgoing_packet, padlen);
913 if (enc && !active_state->send_context.plaintext) {
915 for (i = 0; i < padlen; i++) {
923 memset(cp, 0, padlen);
925 /* packet_length includes payload, padding and padding length field */
926 packet_length = buffer_len(&active_state->outgoing_packet) - 4;
927 cp = buffer_ptr(&active_state->outgoing_packet);
928 put_u32(cp, packet_length);
930 DBG(debug("send: len %d (includes padlen %d)", packet_length+4, padlen));
932 /* compute MAC over seqnr and packet(length fields, payload, padding) */
933 if (mac && mac->enabled) {
934 macbuf = mac_compute(mac, active_state->p_send.seqnr,
935 buffer_ptr(&active_state->outgoing_packet),
936 buffer_len(&active_state->outgoing_packet));
937 DBG(debug("done calc MAC out #%d", active_state->p_send.seqnr));
939 /* encrypt packet and append to output buffer. */
940 cp = buffer_append_space(&active_state->output,
941 buffer_len(&active_state->outgoing_packet));
942 cipher_crypt(&active_state->send_context, cp,
943 buffer_ptr(&active_state->outgoing_packet),
944 buffer_len(&active_state->outgoing_packet));
945 /* append unencrypted MAC */
946 if (mac && mac->enabled)
947 buffer_append(&active_state->output, macbuf, mac->mac_len);
949 fprintf(stderr, "encrypted: ");
950 buffer_dump(&active_state->output);
952 /* increment sequence number for outgoing packets */
953 if (++active_state->p_send.seqnr == 0)
954 logit("outgoing seqnr wraps around");
955 if (++active_state->p_send.packets == 0)
956 if (!(datafellows & SSH_BUG_NOREKEY))
957 fatal("XXX too many packets with same key");
958 active_state->p_send.blocks += (packet_length + 4) / block_size;
959 active_state->p_send.bytes += packet_length + 4;
960 buffer_clear(&active_state->outgoing_packet);
962 if (type == SSH2_MSG_NEWKEYS)
963 set_newkeys(MODE_OUT);
964 else if (type == SSH2_MSG_USERAUTH_SUCCESS && active_state->server_side)
965 packet_enable_delayed_compress();
974 cp = buffer_ptr(&active_state->outgoing_packet);
977 /* during rekeying we can only send key exchange messages */
978 if (active_state->rekeying) {
979 if (!((type >= SSH2_MSG_TRANSPORT_MIN) &&
980 (type <= SSH2_MSG_TRANSPORT_MAX))) {
981 debug("enqueue packet: %u", type);
982 p = xmalloc(sizeof(*p));
984 memcpy(&p->payload, &active_state->outgoing_packet,
986 buffer_init(&active_state->outgoing_packet);
987 TAILQ_INSERT_TAIL(&active_state->outgoing, p, next);
992 /* rekeying starts with sending KEXINIT */
993 if (type == SSH2_MSG_KEXINIT)
994 active_state->rekeying = 1;
996 packet_send2_wrapped();
998 /* after a NEWKEYS message we can send the complete queue */
999 if (type == SSH2_MSG_NEWKEYS) {
1000 active_state->rekeying = 0;
1001 while ((p = TAILQ_FIRST(&active_state->outgoing))) {
1003 debug("dequeue packet: %u", type);
1004 buffer_free(&active_state->outgoing_packet);
1005 memcpy(&active_state->outgoing_packet, &p->payload,
1007 TAILQ_REMOVE(&active_state->outgoing, p, next);
1009 packet_send2_wrapped();
1021 DBG(debug("packet_send done"));
1025 * Waits until a packet has been received, and returns its type. Note that
1026 * no other data is processed until this returns, so this function should not
1027 * be used during the interactive session.
1031 packet_read_seqnr(u_int32_t *seqnr_p)
1033 int type, len, ret, ms_remain, cont;
1036 struct timeval timeout, start, *timeoutp = NULL;
1038 DBG(debug("packet_read()"));
1040 setp = (fd_set *)xcalloc(howmany(active_state->connection_in + 1,
1041 NFDBITS), sizeof(fd_mask));
1043 /* Since we are blocking, ensure that all written packets have been sent. */
1044 packet_write_wait();
1046 /* Stay in the loop until we have received a complete packet. */
1048 /* Try to read a packet from the buffer. */
1049 type = packet_read_poll_seqnr(seqnr_p);
1051 type == SSH_SMSG_SUCCESS
1052 || type == SSH_SMSG_FAILURE
1053 || type == SSH_CMSG_EOF
1054 || type == SSH_CMSG_EXIT_CONFIRMATION))
1056 /* If we got a packet, return it. */
1057 if (type != SSH_MSG_NONE) {
1062 * Otherwise, wait for some data to arrive, add it to the
1063 * buffer, and try again.
1065 memset(setp, 0, howmany(active_state->connection_in + 1,
1066 NFDBITS) * sizeof(fd_mask));
1067 FD_SET(active_state->connection_in, setp);
1069 if (active_state->packet_timeout_ms > 0) {
1070 ms_remain = active_state->packet_timeout_ms;
1071 timeoutp = &timeout;
1073 /* Wait for some data to arrive. */
1075 if (active_state->packet_timeout_ms != -1) {
1076 ms_to_timeval(&timeout, ms_remain);
1077 gettimeofday(&start, NULL);
1079 if ((ret = select(active_state->connection_in + 1, setp,
1080 NULL, NULL, timeoutp)) >= 0)
1082 if (errno != EAGAIN && errno != EINTR &&
1083 errno != EWOULDBLOCK)
1085 if (active_state->packet_timeout_ms == -1)
1087 ms_subtract_diff(&start, &ms_remain);
1088 if (ms_remain <= 0) {
1094 logit("Connection to %.200s timed out while "
1095 "waiting to read", get_remote_ipaddr());
1098 /* Read data from the socket. */
1101 len = roaming_read(active_state->connection_in, buf,
1102 sizeof(buf), &cont);
1103 } while (len == 0 && cont);
1105 logit("Connection closed by %.200s", get_remote_ipaddr());
1109 fatal("Read from socket failed: %.100s", strerror(errno));
1110 /* Append it to the buffer. */
1111 packet_process_incoming(buf, len);
1119 return packet_read_seqnr(NULL);
1123 * Waits until a packet has been received, verifies that its type matches
1124 * that given, and gives a fatal error and exits if there is a mismatch.
1128 packet_read_expect(int expected_type)
1132 type = packet_read();
1133 if (type != expected_type)
1134 packet_disconnect("Protocol error: expected packet type %d, got %d",
1135 expected_type, type);
1138 /* Checks if a full packet is available in the data received so far via
1139 * packet_process_incoming. If so, reads the packet; otherwise returns
1140 * SSH_MSG_NONE. This does not wait for data from the connection.
1142 * SSH_MSG_DISCONNECT is handled specially here. Also,
1143 * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1148 packet_read_poll1(void)
1150 u_int len, padded_len;
1152 u_int checksum, stored_checksum;
1154 /* Check if input size is less than minimum packet size. */
1155 if (buffer_len(&active_state->input) < 4 + 8)
1156 return SSH_MSG_NONE;
1157 /* Get length of incoming packet. */
1158 cp = buffer_ptr(&active_state->input);
1160 if (len < 1 + 2 + 2 || len > 256 * 1024)
1161 packet_disconnect("Bad packet length %u.", len);
1162 padded_len = (len + 8) & ~7;
1164 /* Check if the packet has been entirely received. */
1165 if (buffer_len(&active_state->input) < 4 + padded_len)
1166 return SSH_MSG_NONE;
1168 /* The entire packet is in buffer. */
1170 /* Consume packet length. */
1171 buffer_consume(&active_state->input, 4);
1174 * Cryptographic attack detector for ssh
1175 * (C)1998 CORE-SDI, Buenos Aires Argentina
1176 * Ariel Futoransky(futo@core-sdi.com)
1178 if (!active_state->receive_context.plaintext) {
1179 switch (detect_attack(buffer_ptr(&active_state->input),
1181 case DEATTACK_DETECTED:
1182 packet_disconnect("crc32 compensation attack: "
1183 "network attack detected");
1184 case DEATTACK_DOS_DETECTED:
1185 packet_disconnect("deattack denial of "
1186 "service detected");
1190 /* Decrypt data to incoming_packet. */
1191 buffer_clear(&active_state->incoming_packet);
1192 cp = buffer_append_space(&active_state->incoming_packet, padded_len);
1193 cipher_crypt(&active_state->receive_context, cp,
1194 buffer_ptr(&active_state->input), padded_len);
1196 buffer_consume(&active_state->input, padded_len);
1199 fprintf(stderr, "read_poll plain: ");
1200 buffer_dump(&active_state->incoming_packet);
1203 /* Compute packet checksum. */
1204 checksum = ssh_crc32(buffer_ptr(&active_state->incoming_packet),
1205 buffer_len(&active_state->incoming_packet) - 4);
1208 buffer_consume(&active_state->incoming_packet, 8 - len % 8);
1210 /* Test check bytes. */
1211 if (len != buffer_len(&active_state->incoming_packet))
1212 packet_disconnect("packet_read_poll1: len %d != buffer_len %d.",
1213 len, buffer_len(&active_state->incoming_packet));
1215 cp = (u_char *)buffer_ptr(&active_state->incoming_packet) + len - 4;
1216 stored_checksum = get_u32(cp);
1217 if (checksum != stored_checksum)
1218 packet_disconnect("Corrupted check bytes on input.");
1219 buffer_consume_end(&active_state->incoming_packet, 4);
1221 if (active_state->packet_compression) {
1222 buffer_clear(&active_state->compression_buffer);
1223 buffer_uncompress(&active_state->incoming_packet,
1224 &active_state->compression_buffer);
1225 buffer_clear(&active_state->incoming_packet);
1226 buffer_append(&active_state->incoming_packet,
1227 buffer_ptr(&active_state->compression_buffer),
1228 buffer_len(&active_state->compression_buffer));
1230 active_state->p_read.packets++;
1231 active_state->p_read.bytes += padded_len + 4;
1232 type = buffer_get_char(&active_state->incoming_packet);
1233 if (type < SSH_MSG_MIN || type > SSH_MSG_MAX)
1234 packet_disconnect("Invalid ssh1 packet type: %d", type);
1239 packet_read_poll2(u_int32_t *seqnr_p)
1242 u_char *macbuf, *cp, type;
1243 u_int maclen, block_size;
1248 if (active_state->packet_discard)
1249 return SSH_MSG_NONE;
1251 if (active_state->newkeys[MODE_IN] != NULL) {
1252 enc = &active_state->newkeys[MODE_IN]->enc;
1253 mac = &active_state->newkeys[MODE_IN]->mac;
1254 comp = &active_state->newkeys[MODE_IN]->comp;
1256 maclen = mac && mac->enabled ? mac->mac_len : 0;
1257 block_size = enc ? enc->block_size : 8;
1259 if (active_state->packlen == 0) {
1261 * check if input size is less than the cipher block size,
1262 * decrypt first block and extract length of incoming packet
1264 if (buffer_len(&active_state->input) < block_size)
1265 return SSH_MSG_NONE;
1266 buffer_clear(&active_state->incoming_packet);
1267 cp = buffer_append_space(&active_state->incoming_packet,
1269 cipher_crypt(&active_state->receive_context, cp,
1270 buffer_ptr(&active_state->input), block_size);
1271 cp = buffer_ptr(&active_state->incoming_packet);
1272 active_state->packlen = get_u32(cp);
1273 if (active_state->packlen < 1 + 4 ||
1274 active_state->packlen > PACKET_MAX_SIZE) {
1276 buffer_dump(&active_state->incoming_packet);
1278 logit("Bad packet length %u.", active_state->packlen);
1279 packet_start_discard(enc, mac, active_state->packlen,
1281 return SSH_MSG_NONE;
1283 DBG(debug("input: packet len %u", active_state->packlen+4));
1284 buffer_consume(&active_state->input, block_size);
1286 /* we have a partial packet of block_size bytes */
1287 need = 4 + active_state->packlen - block_size;
1288 DBG(debug("partial packet %d, need %d, maclen %d", block_size,
1290 if (need % block_size != 0) {
1291 logit("padding error: need %d block %d mod %d",
1292 need, block_size, need % block_size);
1293 packet_start_discard(enc, mac, active_state->packlen,
1294 PACKET_MAX_SIZE - block_size);
1295 return SSH_MSG_NONE;
1298 * check if the entire packet has been received and
1299 * decrypt into incoming_packet
1301 if (buffer_len(&active_state->input) < need + maclen)
1302 return SSH_MSG_NONE;
1304 fprintf(stderr, "read_poll enc/full: ");
1305 buffer_dump(&active_state->input);
1307 cp = buffer_append_space(&active_state->incoming_packet, need);
1308 cipher_crypt(&active_state->receive_context, cp,
1309 buffer_ptr(&active_state->input), need);
1310 buffer_consume(&active_state->input, need);
1312 * compute MAC over seqnr and packet,
1313 * increment sequence number for incoming packet
1315 if (mac && mac->enabled) {
1316 macbuf = mac_compute(mac, active_state->p_read.seqnr,
1317 buffer_ptr(&active_state->incoming_packet),
1318 buffer_len(&active_state->incoming_packet));
1319 if (timingsafe_bcmp(macbuf, buffer_ptr(&active_state->input),
1320 mac->mac_len) != 0) {
1321 logit("Corrupted MAC on input.");
1322 if (need > PACKET_MAX_SIZE)
1323 fatal("internal error need %d", need);
1324 packet_start_discard(enc, mac, active_state->packlen,
1325 PACKET_MAX_SIZE - need);
1326 return SSH_MSG_NONE;
1329 DBG(debug("MAC #%d ok", active_state->p_read.seqnr));
1330 buffer_consume(&active_state->input, mac->mac_len);
1332 /* XXX now it's safe to use fatal/packet_disconnect */
1333 if (seqnr_p != NULL)
1334 *seqnr_p = active_state->p_read.seqnr;
1335 if (++active_state->p_read.seqnr == 0)
1336 logit("incoming seqnr wraps around");
1337 if (++active_state->p_read.packets == 0)
1338 if (!(datafellows & SSH_BUG_NOREKEY))
1339 fatal("XXX too many packets with same key");
1340 active_state->p_read.blocks += (active_state->packlen + 4) / block_size;
1341 active_state->p_read.bytes += active_state->packlen + 4;
1344 cp = buffer_ptr(&active_state->incoming_packet);
1346 DBG(debug("input: padlen %d", padlen));
1348 packet_disconnect("Corrupted padlen %d on input.", padlen);
1350 /* skip packet size + padlen, discard padding */
1351 buffer_consume(&active_state->incoming_packet, 4 + 1);
1352 buffer_consume_end(&active_state->incoming_packet, padlen);
1354 DBG(debug("input: len before de-compress %d",
1355 buffer_len(&active_state->incoming_packet)));
1356 if (comp && comp->enabled) {
1357 buffer_clear(&active_state->compression_buffer);
1358 buffer_uncompress(&active_state->incoming_packet,
1359 &active_state->compression_buffer);
1360 buffer_clear(&active_state->incoming_packet);
1361 buffer_append(&active_state->incoming_packet,
1362 buffer_ptr(&active_state->compression_buffer),
1363 buffer_len(&active_state->compression_buffer));
1364 DBG(debug("input: len after de-compress %d",
1365 buffer_len(&active_state->incoming_packet)));
1368 * get packet type, implies consume.
1369 * return length of payload (without type field)
1371 type = buffer_get_char(&active_state->incoming_packet);
1372 if (type < SSH2_MSG_MIN || type >= SSH2_MSG_LOCAL_MIN)
1373 packet_disconnect("Invalid ssh2 packet type: %d", type);
1374 if (type == SSH2_MSG_NEWKEYS)
1375 set_newkeys(MODE_IN);
1376 else if (type == SSH2_MSG_USERAUTH_SUCCESS &&
1377 !active_state->server_side)
1378 packet_enable_delayed_compress();
1380 fprintf(stderr, "read/plain[%d]:\r\n", type);
1381 buffer_dump(&active_state->incoming_packet);
1383 /* reset for next packet */
1384 active_state->packlen = 0;
1389 packet_read_poll_seqnr(u_int32_t *seqnr_p)
1391 u_int reason, seqnr;
1397 type = packet_read_poll2(seqnr_p);
1399 active_state->keep_alive_timeouts = 0;
1400 DBG(debug("received packet type %d", type));
1403 case SSH2_MSG_IGNORE:
1404 debug3("Received SSH2_MSG_IGNORE");
1406 case SSH2_MSG_DEBUG:
1408 msg = packet_get_string(NULL);
1409 debug("Remote: %.900s", msg);
1411 msg = packet_get_string(NULL);
1414 case SSH2_MSG_DISCONNECT:
1415 reason = packet_get_int();
1416 msg = packet_get_string(NULL);
1417 logit("Received disconnect from %s: %u: %.400s",
1418 get_remote_ipaddr(), reason, msg);
1422 case SSH2_MSG_UNIMPLEMENTED:
1423 seqnr = packet_get_int();
1424 debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1431 type = packet_read_poll1();
1433 case SSH_MSG_IGNORE:
1436 msg = packet_get_string(NULL);
1437 debug("Remote: %.900s", msg);
1440 case SSH_MSG_DISCONNECT:
1441 msg = packet_get_string(NULL);
1442 logit("Received disconnect from %s: %.400s",
1443 get_remote_ipaddr(), msg);
1448 DBG(debug("received packet type %d", type));
1456 packet_read_poll(void)
1458 return packet_read_poll_seqnr(NULL);
1462 * Buffers the given amount of input characters. This is intended to be used
1463 * together with packet_read_poll.
1467 packet_process_incoming(const char *buf, u_int len)
1469 if (active_state->packet_discard) {
1470 active_state->keep_alive_timeouts = 0; /* ?? */
1471 if (len >= active_state->packet_discard)
1472 packet_stop_discard();
1473 active_state->packet_discard -= len;
1476 buffer_append(&active_state->input, buf, len);
1479 /* Returns a character from the packet. */
1482 packet_get_char(void)
1486 buffer_get(&active_state->incoming_packet, &ch, 1);
1490 /* Returns an integer from the packet data. */
1493 packet_get_int(void)
1495 return buffer_get_int(&active_state->incoming_packet);
1498 /* Returns an 64 bit integer from the packet data. */
1501 packet_get_int64(void)
1503 return buffer_get_int64(&active_state->incoming_packet);
1507 * Returns an arbitrary precision integer from the packet data. The integer
1508 * must have been initialized before this call.
1512 packet_get_bignum(BIGNUM * value)
1514 buffer_get_bignum(&active_state->incoming_packet, value);
1518 packet_get_bignum2(BIGNUM * value)
1520 buffer_get_bignum2(&active_state->incoming_packet, value);
1523 #ifdef OPENSSL_HAS_ECC
1525 packet_get_ecpoint(const EC_GROUP *curve, EC_POINT *point)
1527 buffer_get_ecpoint(&active_state->incoming_packet, curve, point);
1532 packet_get_raw(u_int *length_ptr)
1534 u_int bytes = buffer_len(&active_state->incoming_packet);
1536 if (length_ptr != NULL)
1537 *length_ptr = bytes;
1538 return buffer_ptr(&active_state->incoming_packet);
1542 packet_remaining(void)
1544 return buffer_len(&active_state->incoming_packet);
1548 * Returns a string from the packet data. The string is allocated using
1549 * xmalloc; it is the responsibility of the calling program to free it when
1550 * no longer needed. The length_ptr argument may be NULL, or point to an
1551 * integer into which the length of the string is stored.
1555 packet_get_string(u_int *length_ptr)
1557 return buffer_get_string(&active_state->incoming_packet, length_ptr);
1561 packet_get_string_ptr(u_int *length_ptr)
1563 return buffer_get_string_ptr(&active_state->incoming_packet, length_ptr);
1566 /* Ensures the returned string has no embedded \0 characters in it. */
1568 packet_get_cstring(u_int *length_ptr)
1570 return buffer_get_cstring(&active_state->incoming_packet, length_ptr);
1574 * Sends a diagnostic message from the server to the client. This message
1575 * can be sent at any time (but not while constructing another message). The
1576 * message is printed immediately, but only if the client is being executed
1577 * in verbose mode. These messages are primarily intended to ease debugging
1578 * authentication problems. The length of the formatted message must not
1579 * exceed 1024 bytes. This will automatically call packet_write_wait.
1583 packet_send_debug(const char *fmt,...)
1588 if (compat20 && (datafellows & SSH_BUG_DEBUG))
1591 va_start(args, fmt);
1592 vsnprintf(buf, sizeof(buf), fmt, args);
1596 packet_start(SSH2_MSG_DEBUG);
1597 packet_put_char(0); /* bool: always display */
1598 packet_put_cstring(buf);
1599 packet_put_cstring("");
1601 packet_start(SSH_MSG_DEBUG);
1602 packet_put_cstring(buf);
1605 packet_write_wait();
1609 * Logs the error plus constructs and sends a disconnect packet, closes the
1610 * connection, and exits. This function never returns. The error message
1611 * should not contain a newline. The length of the formatted message must
1612 * not exceed 1024 bytes.
1616 packet_disconnect(const char *fmt,...)
1620 static int disconnecting = 0;
1622 if (disconnecting) /* Guard against recursive invocations. */
1623 fatal("packet_disconnect called recursively.");
1627 * Format the message. Note that the caller must make sure the
1628 * message is of limited size.
1630 va_start(args, fmt);
1631 vsnprintf(buf, sizeof(buf), fmt, args);
1634 /* Display the error locally */
1635 logit("Disconnecting: %.100s", buf);
1637 /* Send the disconnect message to the other side, and wait for it to get sent. */
1639 packet_start(SSH2_MSG_DISCONNECT);
1640 packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR);
1641 packet_put_cstring(buf);
1642 packet_put_cstring("");
1644 packet_start(SSH_MSG_DISCONNECT);
1645 packet_put_cstring(buf);
1648 packet_write_wait();
1650 /* Stop listening for connections. */
1651 channel_close_all();
1653 /* Close the connection. */
1658 /* Checks if there is any buffered output, and tries to write some of the output. */
1661 packet_write_poll(void)
1663 int len = buffer_len(&active_state->output);
1668 len = roaming_write(active_state->connection_out,
1669 buffer_ptr(&active_state->output), len, &cont);
1671 if (errno == EINTR || errno == EAGAIN ||
1672 errno == EWOULDBLOCK)
1674 fatal("Write failed: %.100s", strerror(errno));
1676 if (len == 0 && !cont)
1677 fatal("Write connection closed");
1678 buffer_consume(&active_state->output, len);
1683 * Calls packet_write_poll repeatedly until all pending output data has been
1688 packet_write_wait(void)
1692 struct timeval start, timeout, *timeoutp = NULL;
1694 setp = (fd_set *)xcalloc(howmany(active_state->connection_out + 1,
1695 NFDBITS), sizeof(fd_mask));
1696 packet_write_poll();
1697 while (packet_have_data_to_write()) {
1698 memset(setp, 0, howmany(active_state->connection_out + 1,
1699 NFDBITS) * sizeof(fd_mask));
1700 FD_SET(active_state->connection_out, setp);
1702 if (active_state->packet_timeout_ms > 0) {
1703 ms_remain = active_state->packet_timeout_ms;
1704 timeoutp = &timeout;
1707 if (active_state->packet_timeout_ms != -1) {
1708 ms_to_timeval(&timeout, ms_remain);
1709 gettimeofday(&start, NULL);
1711 if ((ret = select(active_state->connection_out + 1,
1712 NULL, setp, NULL, timeoutp)) >= 0)
1714 if (errno != EAGAIN && errno != EINTR &&
1715 errno != EWOULDBLOCK)
1717 if (active_state->packet_timeout_ms == -1)
1719 ms_subtract_diff(&start, &ms_remain);
1720 if (ms_remain <= 0) {
1726 logit("Connection to %.200s timed out while "
1727 "waiting to write", get_remote_ipaddr());
1730 packet_write_poll();
1735 /* Returns true if there is buffered data to write to the connection. */
1738 packet_have_data_to_write(void)
1740 return buffer_len(&active_state->output) != 0;
1743 /* Returns true if there is not too much data to write to the connection. */
1746 packet_not_very_much_data_to_write(void)
1748 if (active_state->interactive_mode)
1749 return buffer_len(&active_state->output) < 16384;
1751 return buffer_len(&active_state->output) < 128 * 1024;
1755 packet_set_tos(int tos)
1757 #ifndef IP_TOS_IS_BROKEN
1758 if (!packet_connection_is_on_socket())
1760 switch (packet_connection_af()) {
1763 debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1764 if (setsockopt(active_state->connection_in,
1765 IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
1766 error("setsockopt IP_TOS %d: %.100s:",
1767 tos, strerror(errno));
1769 # endif /* IP_TOS */
1772 debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1773 if (setsockopt(active_state->connection_in,
1774 IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
1775 error("setsockopt IPV6_TCLASS %d: %.100s:",
1776 tos, strerror(errno));
1778 # endif /* IPV6_TCLASS */
1780 #endif /* IP_TOS_IS_BROKEN */
1783 /* Informs that the current session is interactive. Sets IP flags for that. */
1786 packet_set_interactive(int interactive, int qos_interactive, int qos_bulk)
1788 if (active_state->set_interactive_called)
1790 active_state->set_interactive_called = 1;
1792 /* Record that we are in interactive mode. */
1793 active_state->interactive_mode = interactive;
1795 /* Only set socket options if using a socket. */
1796 if (!packet_connection_is_on_socket())
1798 set_nodelay(active_state->connection_in);
1799 packet_set_tos(interactive ? qos_interactive : qos_bulk);
1802 /* Returns true if the current connection is interactive. */
1805 packet_is_interactive(void)
1807 return active_state->interactive_mode;
1811 packet_set_maxsize(u_int s)
1813 if (active_state->set_maxsize_called) {
1814 logit("packet_set_maxsize: called twice: old %d new %d",
1815 active_state->max_packet_size, s);
1818 if (s < 4 * 1024 || s > 1024 * 1024) {
1819 logit("packet_set_maxsize: bad size %d", s);
1822 active_state->set_maxsize_called = 1;
1823 debug("packet_set_maxsize: setting to %d", s);
1824 active_state->max_packet_size = s;
1829 packet_inc_alive_timeouts(void)
1831 return ++active_state->keep_alive_timeouts;
1835 packet_set_alive_timeouts(int ka)
1837 active_state->keep_alive_timeouts = ka;
1841 packet_get_maxsize(void)
1843 return active_state->max_packet_size;
1846 /* roundup current message to pad bytes */
1848 packet_add_padding(u_char pad)
1850 active_state->extra_pad = pad;
1854 * 9.2. Ignored Data Message
1856 * byte SSH_MSG_IGNORE
1859 * All implementations MUST understand (and ignore) this message at any
1860 * time (after receiving the protocol version). No implementation is
1861 * required to send them. This message can be used as an additional
1862 * protection measure against advanced traffic analysis techniques.
1865 packet_send_ignore(int nbytes)
1870 packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE);
1871 packet_put_int(nbytes);
1872 for (i = 0; i < nbytes; i++) {
1875 packet_put_char((u_char)rnd & 0xff);
1880 #ifdef NONE_CIPHER_ENABLED
1882 packet_request_rekeying(void)
1884 rekey_requested = 1;
1888 #define MAX_PACKETS (1U<<31)
1890 packet_need_rekeying(void)
1892 if (datafellows & SSH_BUG_NOREKEY)
1894 #ifdef NONE_CIPHER_ENABLED
1895 if (rekey_requested == 1) {
1896 rekey_requested = 0;
1901 (active_state->p_send.packets > MAX_PACKETS) ||
1902 (active_state->p_read.packets > MAX_PACKETS) ||
1903 (active_state->max_blocks_out &&
1904 (active_state->p_send.blocks > active_state->max_blocks_out)) ||
1905 (active_state->max_blocks_in &&
1906 (active_state->p_read.blocks > active_state->max_blocks_in));
1910 packet_set_rekey_limit(u_int32_t bytes)
1912 active_state->rekey_limit = bytes;
1916 packet_set_server(void)
1918 active_state->server_side = 1;
1922 packet_set_authenticated(void)
1924 active_state->after_authentication = 1;
1928 packet_get_input(void)
1930 return (void *)&active_state->input;
1934 packet_get_output(void)
1936 return (void *)&active_state->output;
1940 packet_get_newkeys(int mode)
1942 return (void *)active_state->newkeys[mode];
1946 * Save the state for the real connection, and use a separate state when
1947 * resuming a suspended connection.
1950 packet_backup_state(void)
1952 struct session_state *tmp;
1954 close(active_state->connection_in);
1955 active_state->connection_in = -1;
1956 close(active_state->connection_out);
1957 active_state->connection_out = -1;
1961 tmp = alloc_session_state();
1962 backup_state = active_state;
1967 * Swap in the old state when resuming a connecion.
1970 packet_restore_state(void)
1972 struct session_state *tmp;
1977 backup_state = active_state;
1979 active_state->connection_in = backup_state->connection_in;
1980 backup_state->connection_in = -1;
1981 active_state->connection_out = backup_state->connection_out;
1982 backup_state->connection_out = -1;
1983 len = buffer_len(&backup_state->input);
1985 buf = buffer_ptr(&backup_state->input);
1986 buffer_append(&active_state->input, buf, len);
1987 buffer_clear(&backup_state->input);
1988 add_recv_bytes(len);
1992 #ifdef NONE_CIPHER_ENABLED
1994 packet_get_authentication_state(void)
1996 return (active_state->after_authentication);