1 /* $OpenBSD: packet.c,v 1.181 2013/02/10 23:35:24 djm Exp $ */
2 /* $OpenBSD: packet.c,v 1.182 2013/04/11 02:27:50 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) || (mac && mac->etm))
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,
440 if (to.ss_family == AF_INET6 &&
441 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr))
447 /* Sets the connection into non-blocking mode. */
450 packet_set_nonblocking(void)
452 /* Set the socket into non-blocking mode. */
453 set_nonblock(active_state->connection_in);
455 if (active_state->connection_out != active_state->connection_in)
456 set_nonblock(active_state->connection_out);
459 /* Returns the socket used for reading. */
462 packet_get_connection_in(void)
464 return active_state->connection_in;
467 /* Returns the descriptor used for writing. */
470 packet_get_connection_out(void)
472 return active_state->connection_out;
475 /* Closes the connection and clears and frees internal data structures. */
480 if (!active_state->initialized)
482 active_state->initialized = 0;
483 if (active_state->connection_in == active_state->connection_out) {
484 shutdown(active_state->connection_out, SHUT_RDWR);
485 close(active_state->connection_out);
487 close(active_state->connection_in);
488 close(active_state->connection_out);
490 buffer_free(&active_state->input);
491 buffer_free(&active_state->output);
492 buffer_free(&active_state->outgoing_packet);
493 buffer_free(&active_state->incoming_packet);
494 if (active_state->compression_buffer_ready) {
495 buffer_free(&active_state->compression_buffer);
496 buffer_compress_uninit();
498 cipher_cleanup(&active_state->send_context);
499 cipher_cleanup(&active_state->receive_context);
502 /* Sets remote side protocol flags. */
505 packet_set_protocol_flags(u_int protocol_flags)
507 active_state->remote_protocol_flags = protocol_flags;
510 /* Returns the remote protocol flags set earlier by the above function. */
513 packet_get_protocol_flags(void)
515 return active_state->remote_protocol_flags;
519 * Starts packet compression from the next packet on in both directions.
520 * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
524 packet_init_compression(void)
526 if (active_state->compression_buffer_ready == 1)
528 active_state->compression_buffer_ready = 1;
529 buffer_init(&active_state->compression_buffer);
533 packet_start_compression(int level)
535 if (active_state->packet_compression && !compat20)
536 fatal("Compression already enabled.");
537 active_state->packet_compression = 1;
538 packet_init_compression();
539 buffer_compress_init_send(level);
540 buffer_compress_init_recv();
544 * Causes any further packets to be encrypted using the given key. The same
545 * key is used for both sending and reception. However, both directions are
546 * encrypted independently of each other.
550 packet_set_encryption_key(const u_char *key, u_int keylen, int number)
552 Cipher *cipher = cipher_by_number(number);
555 fatal("packet_set_encryption_key: unknown cipher number %d", number);
557 fatal("packet_set_encryption_key: keylen too small: %d", keylen);
558 if (keylen > SSH_SESSION_KEY_LENGTH)
559 fatal("packet_set_encryption_key: keylen too big: %d", keylen);
560 memcpy(active_state->ssh1_key, key, keylen);
561 active_state->ssh1_keylen = keylen;
562 cipher_init(&active_state->send_context, cipher, key, keylen, NULL,
564 cipher_init(&active_state->receive_context, cipher, key, keylen, NULL,
569 packet_get_encryption_key(u_char *key)
572 return (active_state->ssh1_keylen);
573 memcpy(key, active_state->ssh1_key, active_state->ssh1_keylen);
574 return (active_state->ssh1_keylen);
577 /* Start constructing a packet to send. */
579 packet_start(u_char type)
584 DBG(debug("packet_start[%d]", type));
585 len = compat20 ? 6 : 9;
586 memset(buf, 0, len - 1);
588 buffer_clear(&active_state->outgoing_packet);
589 buffer_append(&active_state->outgoing_packet, buf, len);
592 /* Append payload. */
594 packet_put_char(int value)
598 buffer_append(&active_state->outgoing_packet, &ch, 1);
602 packet_put_int(u_int value)
604 buffer_put_int(&active_state->outgoing_packet, value);
608 packet_put_int64(u_int64_t value)
610 buffer_put_int64(&active_state->outgoing_packet, value);
614 packet_put_string(const void *buf, u_int len)
616 buffer_put_string(&active_state->outgoing_packet, buf, len);
620 packet_put_cstring(const char *str)
622 buffer_put_cstring(&active_state->outgoing_packet, str);
626 packet_put_raw(const void *buf, u_int len)
628 buffer_append(&active_state->outgoing_packet, buf, len);
632 packet_put_bignum(BIGNUM * value)
634 buffer_put_bignum(&active_state->outgoing_packet, value);
638 packet_put_bignum2(BIGNUM * value)
640 buffer_put_bignum2(&active_state->outgoing_packet, value);
643 #ifdef OPENSSL_HAS_ECC
645 packet_put_ecpoint(const EC_GROUP *curve, const EC_POINT *point)
647 buffer_put_ecpoint(&active_state->outgoing_packet, curve, point);
652 * Finalizes and sends the packet. If the encryption key has been set,
653 * encrypts the packet before sending.
665 * If using packet compression, compress the payload of the outgoing
668 if (active_state->packet_compression) {
669 buffer_clear(&active_state->compression_buffer);
671 buffer_consume(&active_state->outgoing_packet, 8);
673 buffer_append(&active_state->compression_buffer,
674 "\0\0\0\0\0\0\0\0", 8);
675 buffer_compress(&active_state->outgoing_packet,
676 &active_state->compression_buffer);
677 buffer_clear(&active_state->outgoing_packet);
678 buffer_append(&active_state->outgoing_packet,
679 buffer_ptr(&active_state->compression_buffer),
680 buffer_len(&active_state->compression_buffer));
682 /* Compute packet length without padding (add checksum, remove padding). */
683 len = buffer_len(&active_state->outgoing_packet) + 4 - 8;
685 /* Insert padding. Initialized to zero in packet_start1() */
686 padding = 8 - len % 8;
687 if (!active_state->send_context.plaintext) {
688 cp = buffer_ptr(&active_state->outgoing_packet);
689 for (i = 0; i < padding; i++) {
692 cp[7 - i] = rnd & 0xff;
696 buffer_consume(&active_state->outgoing_packet, 8 - padding);
698 /* Add check bytes. */
699 checksum = ssh_crc32(buffer_ptr(&active_state->outgoing_packet),
700 buffer_len(&active_state->outgoing_packet));
701 put_u32(buf, checksum);
702 buffer_append(&active_state->outgoing_packet, buf, 4);
705 fprintf(stderr, "packet_send plain: ");
706 buffer_dump(&active_state->outgoing_packet);
709 /* Append to output. */
711 buffer_append(&active_state->output, buf, 4);
712 cp = buffer_append_space(&active_state->output,
713 buffer_len(&active_state->outgoing_packet));
714 cipher_crypt(&active_state->send_context, cp,
715 buffer_ptr(&active_state->outgoing_packet),
716 buffer_len(&active_state->outgoing_packet), 0, 0);
719 fprintf(stderr, "encrypted: ");
720 buffer_dump(&active_state->output);
722 active_state->p_send.packets++;
723 active_state->p_send.bytes += len +
724 buffer_len(&active_state->outgoing_packet);
725 buffer_clear(&active_state->outgoing_packet);
728 * Note that the packet is now only buffered in output. It won't be
729 * actually sent until packet_write_wait or packet_write_poll is
735 set_newkeys(int mode)
741 u_int64_t *max_blocks;
744 debug2("set_newkeys: mode %d", mode);
746 if (mode == MODE_OUT) {
747 cc = &active_state->send_context;
748 crypt_type = CIPHER_ENCRYPT;
749 active_state->p_send.packets = active_state->p_send.blocks = 0;
750 max_blocks = &active_state->max_blocks_out;
752 cc = &active_state->receive_context;
753 crypt_type = CIPHER_DECRYPT;
754 active_state->p_read.packets = active_state->p_read.blocks = 0;
755 max_blocks = &active_state->max_blocks_in;
757 if (active_state->newkeys[mode] != NULL) {
758 debug("set_newkeys: rekeying");
760 enc = &active_state->newkeys[mode]->enc;
761 mac = &active_state->newkeys[mode]->mac;
762 comp = &active_state->newkeys[mode]->comp;
764 memset(enc->iv, 0, enc->iv_len);
765 memset(enc->key, 0, enc->key_len);
766 memset(mac->key, 0, mac->key_len);
773 xfree(active_state->newkeys[mode]);
775 active_state->newkeys[mode] = kex_get_newkeys(mode);
776 if (active_state->newkeys[mode] == NULL)
777 fatal("newkeys: no keys for mode %d", mode);
778 enc = &active_state->newkeys[mode]->enc;
779 mac = &active_state->newkeys[mode]->mac;
780 comp = &active_state->newkeys[mode]->comp;
781 if (cipher_authlen(enc->cipher) == 0 && mac_init(mac) == 0)
783 DBG(debug("cipher_init_context: %d", mode));
784 cipher_init(cc, enc->cipher, enc->key, enc->key_len,
785 enc->iv, enc->iv_len, crypt_type);
786 /* Deleting the keys does not gain extra security */
787 /* memset(enc->iv, 0, enc->block_size);
788 memset(enc->key, 0, enc->key_len);
789 memset(mac->key, 0, mac->key_len); */
790 if ((comp->type == COMP_ZLIB ||
791 (comp->type == COMP_DELAYED &&
792 active_state->after_authentication)) && comp->enabled == 0) {
793 packet_init_compression();
794 if (mode == MODE_OUT)
795 buffer_compress_init_send(6);
797 buffer_compress_init_recv();
801 * The 2^(blocksize*2) limit is too expensive for 3DES,
802 * blowfish, etc, so enforce a 1GB limit for small blocksizes.
804 if (enc->block_size >= 16)
805 *max_blocks = (u_int64_t)1 << (enc->block_size*2);
807 *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
808 if (active_state->rekey_limit)
809 *max_blocks = MIN(*max_blocks,
810 active_state->rekey_limit / enc->block_size);
814 * Delayed compression for SSH2 is enabled after authentication:
815 * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
816 * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
819 packet_enable_delayed_compress(void)
825 * Remember that we are past the authentication step, so rekeying
826 * with COMP_DELAYED will turn on compression immediately.
828 active_state->after_authentication = 1;
829 for (mode = 0; mode < MODE_MAX; mode++) {
830 /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
831 if (active_state->newkeys[mode] == NULL)
833 comp = &active_state->newkeys[mode]->comp;
834 if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
835 packet_init_compression();
836 if (mode == MODE_OUT)
837 buffer_compress_init_send(6);
839 buffer_compress_init_recv();
846 * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
849 packet_send2_wrapped(void)
851 u_char type, *cp, *macbuf = NULL;
852 u_char padlen, pad = 0;
853 u_int i, len, authlen = 0, aadlen = 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;
864 /* disable mac for authenticated encryption */
865 if ((authlen = cipher_authlen(enc->cipher)) != 0)
868 block_size = enc ? enc->block_size : 8;
869 aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
871 cp = buffer_ptr(&active_state->outgoing_packet);
875 fprintf(stderr, "plain: ");
876 buffer_dump(&active_state->outgoing_packet);
879 if (comp && comp->enabled) {
880 len = buffer_len(&active_state->outgoing_packet);
881 /* skip header, compress only payload */
882 buffer_consume(&active_state->outgoing_packet, 5);
883 buffer_clear(&active_state->compression_buffer);
884 buffer_compress(&active_state->outgoing_packet,
885 &active_state->compression_buffer);
886 buffer_clear(&active_state->outgoing_packet);
887 buffer_append(&active_state->outgoing_packet, "\0\0\0\0\0", 5);
888 buffer_append(&active_state->outgoing_packet,
889 buffer_ptr(&active_state->compression_buffer),
890 buffer_len(&active_state->compression_buffer));
891 DBG(debug("compression: raw %d compressed %d", len,
892 buffer_len(&active_state->outgoing_packet)));
895 /* sizeof (packet_len + pad_len + payload) */
896 len = buffer_len(&active_state->outgoing_packet);
899 * calc size of padding, alloc space, get random data,
900 * minimum padding is 4 bytes
902 len -= aadlen; /* packet length is not encrypted for EtM modes */
903 padlen = block_size - (len % block_size);
905 padlen += block_size;
906 if (active_state->extra_pad) {
907 /* will wrap if extra_pad+padlen > 255 */
908 active_state->extra_pad =
909 roundup(active_state->extra_pad, block_size);
910 pad = active_state->extra_pad -
911 ((len + padlen) % active_state->extra_pad);
912 debug3("packet_send2: adding %d (len %d padlen %d extra_pad %d)",
913 pad, len, padlen, active_state->extra_pad);
915 active_state->extra_pad = 0;
917 cp = buffer_append_space(&active_state->outgoing_packet, padlen);
918 if (enc && !active_state->send_context.plaintext) {
920 for (i = 0; i < padlen; i++) {
928 memset(cp, 0, padlen);
930 /* sizeof (packet_len + pad_len + payload + padding) */
931 len = buffer_len(&active_state->outgoing_packet);
932 cp = buffer_ptr(&active_state->outgoing_packet);
933 /* packet_length includes payload, padding and padding length field */
934 put_u32(cp, len - 4);
936 DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
937 len, padlen, aadlen));
939 /* compute MAC over seqnr and packet(length fields, payload, padding) */
940 if (mac && mac->enabled && !mac->etm) {
941 macbuf = mac_compute(mac, active_state->p_send.seqnr,
942 buffer_ptr(&active_state->outgoing_packet), len);
943 DBG(debug("done calc MAC out #%d", active_state->p_send.seqnr));
945 /* encrypt packet and append to output buffer. */
946 cp = buffer_append_space(&active_state->output, len + authlen);
947 cipher_crypt(&active_state->send_context, cp,
948 buffer_ptr(&active_state->outgoing_packet),
949 len - aadlen, aadlen, authlen);
950 /* append unencrypted MAC */
951 if (mac && mac->enabled) {
953 /* EtM: compute mac over aadlen + cipher text */
954 macbuf = mac_compute(mac,
955 active_state->p_send.seqnr, cp, len);
956 DBG(debug("done calc MAC(EtM) out #%d",
957 active_state->p_send.seqnr));
959 buffer_append(&active_state->output, macbuf, mac->mac_len);
962 fprintf(stderr, "encrypted: ");
963 buffer_dump(&active_state->output);
965 /* increment sequence number for outgoing packets */
966 if (++active_state->p_send.seqnr == 0)
967 logit("outgoing seqnr wraps around");
968 if (++active_state->p_send.packets == 0)
969 if (!(datafellows & SSH_BUG_NOREKEY))
970 fatal("XXX too many packets with same key");
971 active_state->p_send.blocks += len / block_size;
972 active_state->p_send.bytes += len;
973 buffer_clear(&active_state->outgoing_packet);
975 if (type == SSH2_MSG_NEWKEYS)
976 set_newkeys(MODE_OUT);
977 else if (type == SSH2_MSG_USERAUTH_SUCCESS && active_state->server_side)
978 packet_enable_delayed_compress();
987 cp = buffer_ptr(&active_state->outgoing_packet);
990 /* during rekeying we can only send key exchange messages */
991 if (active_state->rekeying) {
992 if ((type < SSH2_MSG_TRANSPORT_MIN) ||
993 (type > SSH2_MSG_TRANSPORT_MAX) ||
994 (type == SSH2_MSG_SERVICE_REQUEST) ||
995 (type == SSH2_MSG_SERVICE_ACCEPT)) {
996 debug("enqueue packet: %u", type);
997 p = xmalloc(sizeof(*p));
999 memcpy(&p->payload, &active_state->outgoing_packet,
1001 buffer_init(&active_state->outgoing_packet);
1002 TAILQ_INSERT_TAIL(&active_state->outgoing, p, next);
1007 /* rekeying starts with sending KEXINIT */
1008 if (type == SSH2_MSG_KEXINIT)
1009 active_state->rekeying = 1;
1011 packet_send2_wrapped();
1013 /* after a NEWKEYS message we can send the complete queue */
1014 if (type == SSH2_MSG_NEWKEYS) {
1015 active_state->rekeying = 0;
1016 while ((p = TAILQ_FIRST(&active_state->outgoing))) {
1018 debug("dequeue packet: %u", type);
1019 buffer_free(&active_state->outgoing_packet);
1020 memcpy(&active_state->outgoing_packet, &p->payload,
1022 TAILQ_REMOVE(&active_state->outgoing, p, next);
1024 packet_send2_wrapped();
1036 DBG(debug("packet_send done"));
1040 * Waits until a packet has been received, and returns its type. Note that
1041 * no other data is processed until this returns, so this function should not
1042 * be used during the interactive session.
1046 packet_read_seqnr(u_int32_t *seqnr_p)
1048 int type, len, ret, ms_remain, cont;
1051 struct timeval timeout, start, *timeoutp = NULL;
1053 DBG(debug("packet_read()"));
1055 setp = (fd_set *)xcalloc(howmany(active_state->connection_in + 1,
1056 NFDBITS), sizeof(fd_mask));
1058 /* Since we are blocking, ensure that all written packets have been sent. */
1059 packet_write_wait();
1061 /* Stay in the loop until we have received a complete packet. */
1063 /* Try to read a packet from the buffer. */
1064 type = packet_read_poll_seqnr(seqnr_p);
1066 type == SSH_SMSG_SUCCESS
1067 || type == SSH_SMSG_FAILURE
1068 || type == SSH_CMSG_EOF
1069 || type == SSH_CMSG_EXIT_CONFIRMATION))
1071 /* If we got a packet, return it. */
1072 if (type != SSH_MSG_NONE) {
1077 * Otherwise, wait for some data to arrive, add it to the
1078 * buffer, and try again.
1080 memset(setp, 0, howmany(active_state->connection_in + 1,
1081 NFDBITS) * sizeof(fd_mask));
1082 FD_SET(active_state->connection_in, setp);
1084 if (active_state->packet_timeout_ms > 0) {
1085 ms_remain = active_state->packet_timeout_ms;
1086 timeoutp = &timeout;
1088 /* Wait for some data to arrive. */
1090 if (active_state->packet_timeout_ms != -1) {
1091 ms_to_timeval(&timeout, ms_remain);
1092 gettimeofday(&start, NULL);
1094 if ((ret = select(active_state->connection_in + 1, setp,
1095 NULL, NULL, timeoutp)) >= 0)
1097 if (errno != EAGAIN && errno != EINTR &&
1098 errno != EWOULDBLOCK)
1100 if (active_state->packet_timeout_ms == -1)
1102 ms_subtract_diff(&start, &ms_remain);
1103 if (ms_remain <= 0) {
1109 logit("Connection to %.200s timed out while "
1110 "waiting to read", get_remote_ipaddr());
1113 /* Read data from the socket. */
1116 len = roaming_read(active_state->connection_in, buf,
1117 sizeof(buf), &cont);
1118 } while (len == 0 && cont);
1120 logit("Connection closed by %.200s", get_remote_ipaddr());
1124 fatal("Read from socket failed: %.100s", strerror(errno));
1125 /* Append it to the buffer. */
1126 packet_process_incoming(buf, len);
1134 return packet_read_seqnr(NULL);
1138 * Waits until a packet has been received, verifies that its type matches
1139 * that given, and gives a fatal error and exits if there is a mismatch.
1143 packet_read_expect(int expected_type)
1147 type = packet_read();
1148 if (type != expected_type)
1149 packet_disconnect("Protocol error: expected packet type %d, got %d",
1150 expected_type, type);
1153 /* Checks if a full packet is available in the data received so far via
1154 * packet_process_incoming. If so, reads the packet; otherwise returns
1155 * SSH_MSG_NONE. This does not wait for data from the connection.
1157 * SSH_MSG_DISCONNECT is handled specially here. Also,
1158 * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1163 packet_read_poll1(void)
1165 u_int len, padded_len;
1167 u_int checksum, stored_checksum;
1169 /* Check if input size is less than minimum packet size. */
1170 if (buffer_len(&active_state->input) < 4 + 8)
1171 return SSH_MSG_NONE;
1172 /* Get length of incoming packet. */
1173 cp = buffer_ptr(&active_state->input);
1175 if (len < 1 + 2 + 2 || len > 256 * 1024)
1176 packet_disconnect("Bad packet length %u.", len);
1177 padded_len = (len + 8) & ~7;
1179 /* Check if the packet has been entirely received. */
1180 if (buffer_len(&active_state->input) < 4 + padded_len)
1181 return SSH_MSG_NONE;
1183 /* The entire packet is in buffer. */
1185 /* Consume packet length. */
1186 buffer_consume(&active_state->input, 4);
1189 * Cryptographic attack detector for ssh
1190 * (C)1998 CORE-SDI, Buenos Aires Argentina
1191 * Ariel Futoransky(futo@core-sdi.com)
1193 if (!active_state->receive_context.plaintext) {
1194 switch (detect_attack(buffer_ptr(&active_state->input),
1196 case DEATTACK_DETECTED:
1197 packet_disconnect("crc32 compensation attack: "
1198 "network attack detected");
1199 case DEATTACK_DOS_DETECTED:
1200 packet_disconnect("deattack denial of "
1201 "service detected");
1205 /* Decrypt data to incoming_packet. */
1206 buffer_clear(&active_state->incoming_packet);
1207 cp = buffer_append_space(&active_state->incoming_packet, padded_len);
1208 cipher_crypt(&active_state->receive_context, cp,
1209 buffer_ptr(&active_state->input), padded_len, 0, 0);
1211 buffer_consume(&active_state->input, padded_len);
1214 fprintf(stderr, "read_poll plain: ");
1215 buffer_dump(&active_state->incoming_packet);
1218 /* Compute packet checksum. */
1219 checksum = ssh_crc32(buffer_ptr(&active_state->incoming_packet),
1220 buffer_len(&active_state->incoming_packet) - 4);
1223 buffer_consume(&active_state->incoming_packet, 8 - len % 8);
1225 /* Test check bytes. */
1226 if (len != buffer_len(&active_state->incoming_packet))
1227 packet_disconnect("packet_read_poll1: len %d != buffer_len %d.",
1228 len, buffer_len(&active_state->incoming_packet));
1230 cp = (u_char *)buffer_ptr(&active_state->incoming_packet) + len - 4;
1231 stored_checksum = get_u32(cp);
1232 if (checksum != stored_checksum)
1233 packet_disconnect("Corrupted check bytes on input.");
1234 buffer_consume_end(&active_state->incoming_packet, 4);
1236 if (active_state->packet_compression) {
1237 buffer_clear(&active_state->compression_buffer);
1238 buffer_uncompress(&active_state->incoming_packet,
1239 &active_state->compression_buffer);
1240 buffer_clear(&active_state->incoming_packet);
1241 buffer_append(&active_state->incoming_packet,
1242 buffer_ptr(&active_state->compression_buffer),
1243 buffer_len(&active_state->compression_buffer));
1245 active_state->p_read.packets++;
1246 active_state->p_read.bytes += padded_len + 4;
1247 type = buffer_get_char(&active_state->incoming_packet);
1248 if (type < SSH_MSG_MIN || type > SSH_MSG_MAX)
1249 packet_disconnect("Invalid ssh1 packet type: %d", type);
1254 packet_read_poll2(u_int32_t *seqnr_p)
1257 u_char *macbuf = NULL, *cp, type;
1258 u_int maclen, authlen = 0, aadlen = 0, block_size;
1263 if (active_state->packet_discard)
1264 return SSH_MSG_NONE;
1266 if (active_state->newkeys[MODE_IN] != NULL) {
1267 enc = &active_state->newkeys[MODE_IN]->enc;
1268 mac = &active_state->newkeys[MODE_IN]->mac;
1269 comp = &active_state->newkeys[MODE_IN]->comp;
1270 /* disable mac for authenticated encryption */
1271 if ((authlen = cipher_authlen(enc->cipher)) != 0)
1274 maclen = mac && mac->enabled ? mac->mac_len : 0;
1275 block_size = enc ? enc->block_size : 8;
1276 aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1278 if (aadlen && active_state->packlen == 0) {
1279 if (buffer_len(&active_state->input) < 4)
1280 return SSH_MSG_NONE;
1281 cp = buffer_ptr(&active_state->input);
1282 active_state->packlen = get_u32(cp);
1283 if (active_state->packlen < 1 + 4 ||
1284 active_state->packlen > PACKET_MAX_SIZE) {
1286 buffer_dump(&active_state->input);
1288 logit("Bad packet length %u.", active_state->packlen);
1289 packet_disconnect("Packet corrupt");
1291 buffer_clear(&active_state->incoming_packet);
1292 } else if (active_state->packlen == 0) {
1294 * check if input size is less than the cipher block size,
1295 * decrypt first block and extract length of incoming packet
1297 if (buffer_len(&active_state->input) < block_size)
1298 return SSH_MSG_NONE;
1299 buffer_clear(&active_state->incoming_packet);
1300 cp = buffer_append_space(&active_state->incoming_packet,
1302 cipher_crypt(&active_state->receive_context, cp,
1303 buffer_ptr(&active_state->input), block_size, 0, 0);
1304 cp = buffer_ptr(&active_state->incoming_packet);
1306 active_state->packlen = get_u32(cp);
1307 if (active_state->packlen < 1 + 4 ||
1308 active_state->packlen > PACKET_MAX_SIZE) {
1310 buffer_dump(&active_state->incoming_packet);
1312 logit("Bad packet length %u.", active_state->packlen);
1313 packet_start_discard(enc, mac, active_state->packlen,
1315 return SSH_MSG_NONE;
1317 buffer_consume(&active_state->input, block_size);
1319 DBG(debug("input: packet len %u", active_state->packlen+4));
1321 /* only the payload is encrypted */
1322 need = active_state->packlen;
1325 * the payload size and the payload are encrypted, but we
1326 * have a partial packet of block_size bytes
1328 need = 4 + active_state->packlen - block_size;
1330 DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1331 " aadlen %d", block_size, need, maclen, authlen, aadlen));
1332 if (need % block_size != 0) {
1333 logit("padding error: need %d block %d mod %d",
1334 need, block_size, need % block_size);
1335 packet_start_discard(enc, mac, active_state->packlen,
1336 PACKET_MAX_SIZE - block_size);
1337 return SSH_MSG_NONE;
1340 * check if the entire packet has been received and
1341 * decrypt into incoming_packet:
1342 * 'aadlen' bytes are unencrypted, but authenticated.
1343 * 'need' bytes are encrypted, followed by either
1344 * 'authlen' bytes of authentication tag or
1345 * 'maclen' bytes of message authentication code.
1347 if (buffer_len(&active_state->input) < aadlen + need + authlen + maclen)
1348 return SSH_MSG_NONE;
1350 fprintf(stderr, "read_poll enc/full: ");
1351 buffer_dump(&active_state->input);
1353 /* EtM: compute mac over encrypted input */
1354 if (mac && mac->enabled && mac->etm)
1355 macbuf = mac_compute(mac, active_state->p_read.seqnr,
1356 buffer_ptr(&active_state->input), aadlen + need);
1357 cp = buffer_append_space(&active_state->incoming_packet, aadlen + need);
1358 cipher_crypt(&active_state->receive_context, cp,
1359 buffer_ptr(&active_state->input), need, aadlen, authlen);
1360 buffer_consume(&active_state->input, aadlen + need + authlen);
1362 * compute MAC over seqnr and packet,
1363 * increment sequence number for incoming packet
1365 if (mac && mac->enabled) {
1367 macbuf = mac_compute(mac, active_state->p_read.seqnr,
1368 buffer_ptr(&active_state->incoming_packet),
1369 buffer_len(&active_state->incoming_packet));
1370 if (timingsafe_bcmp(macbuf, buffer_ptr(&active_state->input),
1371 mac->mac_len) != 0) {
1372 logit("Corrupted MAC on input.");
1373 if (need > PACKET_MAX_SIZE)
1374 fatal("internal error need %d", need);
1375 packet_start_discard(enc, mac, active_state->packlen,
1376 PACKET_MAX_SIZE - need);
1377 return SSH_MSG_NONE;
1380 DBG(debug("MAC #%d ok", active_state->p_read.seqnr));
1381 buffer_consume(&active_state->input, mac->mac_len);
1383 /* XXX now it's safe to use fatal/packet_disconnect */
1384 if (seqnr_p != NULL)
1385 *seqnr_p = active_state->p_read.seqnr;
1386 if (++active_state->p_read.seqnr == 0)
1387 logit("incoming seqnr wraps around");
1388 if (++active_state->p_read.packets == 0)
1389 if (!(datafellows & SSH_BUG_NOREKEY))
1390 fatal("XXX too many packets with same key");
1391 active_state->p_read.blocks += (active_state->packlen + 4) / block_size;
1392 active_state->p_read.bytes += active_state->packlen + 4;
1395 cp = buffer_ptr(&active_state->incoming_packet);
1397 DBG(debug("input: padlen %d", padlen));
1399 packet_disconnect("Corrupted padlen %d on input.", padlen);
1401 /* skip packet size + padlen, discard padding */
1402 buffer_consume(&active_state->incoming_packet, 4 + 1);
1403 buffer_consume_end(&active_state->incoming_packet, padlen);
1405 DBG(debug("input: len before de-compress %d",
1406 buffer_len(&active_state->incoming_packet)));
1407 if (comp && comp->enabled) {
1408 buffer_clear(&active_state->compression_buffer);
1409 buffer_uncompress(&active_state->incoming_packet,
1410 &active_state->compression_buffer);
1411 buffer_clear(&active_state->incoming_packet);
1412 buffer_append(&active_state->incoming_packet,
1413 buffer_ptr(&active_state->compression_buffer),
1414 buffer_len(&active_state->compression_buffer));
1415 DBG(debug("input: len after de-compress %d",
1416 buffer_len(&active_state->incoming_packet)));
1419 * get packet type, implies consume.
1420 * return length of payload (without type field)
1422 type = buffer_get_char(&active_state->incoming_packet);
1423 if (type < SSH2_MSG_MIN || type >= SSH2_MSG_LOCAL_MIN)
1424 packet_disconnect("Invalid ssh2 packet type: %d", type);
1425 if (type == SSH2_MSG_NEWKEYS)
1426 set_newkeys(MODE_IN);
1427 else if (type == SSH2_MSG_USERAUTH_SUCCESS &&
1428 !active_state->server_side)
1429 packet_enable_delayed_compress();
1431 fprintf(stderr, "read/plain[%d]:\r\n", type);
1432 buffer_dump(&active_state->incoming_packet);
1434 /* reset for next packet */
1435 active_state->packlen = 0;
1440 packet_read_poll_seqnr(u_int32_t *seqnr_p)
1442 u_int reason, seqnr;
1448 type = packet_read_poll2(seqnr_p);
1450 active_state->keep_alive_timeouts = 0;
1451 DBG(debug("received packet type %d", type));
1454 case SSH2_MSG_IGNORE:
1455 debug3("Received SSH2_MSG_IGNORE");
1457 case SSH2_MSG_DEBUG:
1459 msg = packet_get_string(NULL);
1460 debug("Remote: %.900s", msg);
1462 msg = packet_get_string(NULL);
1465 case SSH2_MSG_DISCONNECT:
1466 reason = packet_get_int();
1467 msg = packet_get_string(NULL);
1468 /* Ignore normal client exit notifications */
1469 do_log2(active_state->server_side &&
1470 reason == SSH2_DISCONNECT_BY_APPLICATION ?
1471 SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1472 "Received disconnect from %s: %u: %.400s",
1473 get_remote_ipaddr(), reason, msg);
1477 case SSH2_MSG_UNIMPLEMENTED:
1478 seqnr = packet_get_int();
1479 debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1486 type = packet_read_poll1();
1488 case SSH_MSG_IGNORE:
1491 msg = packet_get_string(NULL);
1492 debug("Remote: %.900s", msg);
1495 case SSH_MSG_DISCONNECT:
1496 msg = packet_get_string(NULL);
1497 logit("Received disconnect from %s: %.400s",
1498 get_remote_ipaddr(), msg);
1503 DBG(debug("received packet type %d", type));
1511 * Buffers the given amount of input characters. This is intended to be used
1512 * together with packet_read_poll.
1516 packet_process_incoming(const char *buf, u_int len)
1518 if (active_state->packet_discard) {
1519 active_state->keep_alive_timeouts = 0; /* ?? */
1520 if (len >= active_state->packet_discard)
1521 packet_stop_discard();
1522 active_state->packet_discard -= len;
1525 buffer_append(&active_state->input, buf, len);
1528 /* Returns a character from the packet. */
1531 packet_get_char(void)
1535 buffer_get(&active_state->incoming_packet, &ch, 1);
1539 /* Returns an integer from the packet data. */
1542 packet_get_int(void)
1544 return buffer_get_int(&active_state->incoming_packet);
1547 /* Returns an 64 bit integer from the packet data. */
1550 packet_get_int64(void)
1552 return buffer_get_int64(&active_state->incoming_packet);
1556 * Returns an arbitrary precision integer from the packet data. The integer
1557 * must have been initialized before this call.
1561 packet_get_bignum(BIGNUM * value)
1563 buffer_get_bignum(&active_state->incoming_packet, value);
1567 packet_get_bignum2(BIGNUM * value)
1569 buffer_get_bignum2(&active_state->incoming_packet, value);
1572 #ifdef OPENSSL_HAS_ECC
1574 packet_get_ecpoint(const EC_GROUP *curve, EC_POINT *point)
1576 buffer_get_ecpoint(&active_state->incoming_packet, curve, point);
1581 packet_get_raw(u_int *length_ptr)
1583 u_int bytes = buffer_len(&active_state->incoming_packet);
1585 if (length_ptr != NULL)
1586 *length_ptr = bytes;
1587 return buffer_ptr(&active_state->incoming_packet);
1591 packet_remaining(void)
1593 return buffer_len(&active_state->incoming_packet);
1597 * Returns a string from the packet data. The string is allocated using
1598 * xmalloc; it is the responsibility of the calling program to free it when
1599 * no longer needed. The length_ptr argument may be NULL, or point to an
1600 * integer into which the length of the string is stored.
1604 packet_get_string(u_int *length_ptr)
1606 return buffer_get_string(&active_state->incoming_packet, length_ptr);
1610 packet_get_string_ptr(u_int *length_ptr)
1612 return buffer_get_string_ptr(&active_state->incoming_packet, length_ptr);
1615 /* Ensures the returned string has no embedded \0 characters in it. */
1617 packet_get_cstring(u_int *length_ptr)
1619 return buffer_get_cstring(&active_state->incoming_packet, length_ptr);
1623 * Sends a diagnostic message from the server to the client. This message
1624 * can be sent at any time (but not while constructing another message). The
1625 * message is printed immediately, but only if the client is being executed
1626 * in verbose mode. These messages are primarily intended to ease debugging
1627 * authentication problems. The length of the formatted message must not
1628 * exceed 1024 bytes. This will automatically call packet_write_wait.
1632 packet_send_debug(const char *fmt,...)
1637 if (compat20 && (datafellows & SSH_BUG_DEBUG))
1640 va_start(args, fmt);
1641 vsnprintf(buf, sizeof(buf), fmt, args);
1645 packet_start(SSH2_MSG_DEBUG);
1646 packet_put_char(0); /* bool: always display */
1647 packet_put_cstring(buf);
1648 packet_put_cstring("");
1650 packet_start(SSH_MSG_DEBUG);
1651 packet_put_cstring(buf);
1654 packet_write_wait();
1658 * Logs the error plus constructs and sends a disconnect packet, closes the
1659 * connection, and exits. This function never returns. The error message
1660 * should not contain a newline. The length of the formatted message must
1661 * not exceed 1024 bytes.
1665 packet_disconnect(const char *fmt,...)
1669 static int disconnecting = 0;
1671 if (disconnecting) /* Guard against recursive invocations. */
1672 fatal("packet_disconnect called recursively.");
1676 * Format the message. Note that the caller must make sure the
1677 * message is of limited size.
1679 va_start(args, fmt);
1680 vsnprintf(buf, sizeof(buf), fmt, args);
1683 /* Display the error locally */
1684 logit("Disconnecting: %.100s", buf);
1686 /* Send the disconnect message to the other side, and wait for it to get sent. */
1688 packet_start(SSH2_MSG_DISCONNECT);
1689 packet_put_int(SSH2_DISCONNECT_PROTOCOL_ERROR);
1690 packet_put_cstring(buf);
1691 packet_put_cstring("");
1693 packet_start(SSH_MSG_DISCONNECT);
1694 packet_put_cstring(buf);
1697 packet_write_wait();
1699 /* Stop listening for connections. */
1700 channel_close_all();
1702 /* Close the connection. */
1707 /* Checks if there is any buffered output, and tries to write some of the output. */
1710 packet_write_poll(void)
1712 int len = buffer_len(&active_state->output);
1717 len = roaming_write(active_state->connection_out,
1718 buffer_ptr(&active_state->output), len, &cont);
1720 if (errno == EINTR || errno == EAGAIN ||
1721 errno == EWOULDBLOCK)
1723 fatal("Write failed: %.100s", strerror(errno));
1725 if (len == 0 && !cont)
1726 fatal("Write connection closed");
1727 buffer_consume(&active_state->output, len);
1732 * Calls packet_write_poll repeatedly until all pending output data has been
1737 packet_write_wait(void)
1741 struct timeval start, timeout, *timeoutp = NULL;
1743 setp = (fd_set *)xcalloc(howmany(active_state->connection_out + 1,
1744 NFDBITS), sizeof(fd_mask));
1745 packet_write_poll();
1746 while (packet_have_data_to_write()) {
1747 memset(setp, 0, howmany(active_state->connection_out + 1,
1748 NFDBITS) * sizeof(fd_mask));
1749 FD_SET(active_state->connection_out, setp);
1751 if (active_state->packet_timeout_ms > 0) {
1752 ms_remain = active_state->packet_timeout_ms;
1753 timeoutp = &timeout;
1756 if (active_state->packet_timeout_ms != -1) {
1757 ms_to_timeval(&timeout, ms_remain);
1758 gettimeofday(&start, NULL);
1760 if ((ret = select(active_state->connection_out + 1,
1761 NULL, setp, NULL, timeoutp)) >= 0)
1763 if (errno != EAGAIN && errno != EINTR &&
1764 errno != EWOULDBLOCK)
1766 if (active_state->packet_timeout_ms == -1)
1768 ms_subtract_diff(&start, &ms_remain);
1769 if (ms_remain <= 0) {
1775 logit("Connection to %.200s timed out while "
1776 "waiting to write", get_remote_ipaddr());
1779 packet_write_poll();
1784 /* Returns true if there is buffered data to write to the connection. */
1787 packet_have_data_to_write(void)
1789 return buffer_len(&active_state->output) != 0;
1792 /* Returns true if there is not too much data to write to the connection. */
1795 packet_not_very_much_data_to_write(void)
1797 if (active_state->interactive_mode)
1798 return buffer_len(&active_state->output) < 16384;
1800 return buffer_len(&active_state->output) < 128 * 1024;
1804 packet_set_tos(int tos)
1806 #ifndef IP_TOS_IS_BROKEN
1807 if (!packet_connection_is_on_socket())
1809 switch (packet_connection_af()) {
1812 debug3("%s: set IP_TOS 0x%02x", __func__, tos);
1813 if (setsockopt(active_state->connection_in,
1814 IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
1815 error("setsockopt IP_TOS %d: %.100s:",
1816 tos, strerror(errno));
1818 # endif /* IP_TOS */
1821 debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
1822 if (setsockopt(active_state->connection_in,
1823 IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
1824 error("setsockopt IPV6_TCLASS %d: %.100s:",
1825 tos, strerror(errno));
1827 # endif /* IPV6_TCLASS */
1829 #endif /* IP_TOS_IS_BROKEN */
1832 /* Informs that the current session is interactive. Sets IP flags for that. */
1835 packet_set_interactive(int interactive, int qos_interactive, int qos_bulk)
1837 if (active_state->set_interactive_called)
1839 active_state->set_interactive_called = 1;
1841 /* Record that we are in interactive mode. */
1842 active_state->interactive_mode = interactive;
1844 /* Only set socket options if using a socket. */
1845 if (!packet_connection_is_on_socket())
1847 set_nodelay(active_state->connection_in);
1848 packet_set_tos(interactive ? qos_interactive : qos_bulk);
1851 /* Returns true if the current connection is interactive. */
1854 packet_is_interactive(void)
1856 return active_state->interactive_mode;
1860 packet_set_maxsize(u_int s)
1862 if (active_state->set_maxsize_called) {
1863 logit("packet_set_maxsize: called twice: old %d new %d",
1864 active_state->max_packet_size, s);
1867 if (s < 4 * 1024 || s > 1024 * 1024) {
1868 logit("packet_set_maxsize: bad size %d", s);
1871 active_state->set_maxsize_called = 1;
1872 debug("packet_set_maxsize: setting to %d", s);
1873 active_state->max_packet_size = s;
1878 packet_inc_alive_timeouts(void)
1880 return ++active_state->keep_alive_timeouts;
1884 packet_set_alive_timeouts(int ka)
1886 active_state->keep_alive_timeouts = ka;
1890 packet_get_maxsize(void)
1892 return active_state->max_packet_size;
1895 /* roundup current message to pad bytes */
1897 packet_add_padding(u_char pad)
1899 active_state->extra_pad = pad;
1903 * 9.2. Ignored Data Message
1905 * byte SSH_MSG_IGNORE
1908 * All implementations MUST understand (and ignore) this message at any
1909 * time (after receiving the protocol version). No implementation is
1910 * required to send them. This message can be used as an additional
1911 * protection measure against advanced traffic analysis techniques.
1914 packet_send_ignore(int nbytes)
1919 packet_start(compat20 ? SSH2_MSG_IGNORE : SSH_MSG_IGNORE);
1920 packet_put_int(nbytes);
1921 for (i = 0; i < nbytes; i++) {
1924 packet_put_char((u_char)rnd & 0xff);
1929 #ifdef NONE_CIPHER_ENABLED
1931 packet_request_rekeying(void)
1933 rekey_requested = 1;
1937 #define MAX_PACKETS (1U<<31)
1939 packet_need_rekeying(void)
1941 if (datafellows & SSH_BUG_NOREKEY)
1943 #ifdef NONE_CIPHER_ENABLED
1944 if (rekey_requested == 1) {
1945 rekey_requested = 0;
1950 (active_state->p_send.packets > MAX_PACKETS) ||
1951 (active_state->p_read.packets > MAX_PACKETS) ||
1952 (active_state->max_blocks_out &&
1953 (active_state->p_send.blocks > active_state->max_blocks_out)) ||
1954 (active_state->max_blocks_in &&
1955 (active_state->p_read.blocks > active_state->max_blocks_in));
1959 packet_set_rekey_limit(u_int32_t bytes)
1961 active_state->rekey_limit = bytes;
1965 packet_set_server(void)
1967 active_state->server_side = 1;
1971 packet_set_authenticated(void)
1973 active_state->after_authentication = 1;
1977 packet_get_input(void)
1979 return (void *)&active_state->input;
1983 packet_get_output(void)
1985 return (void *)&active_state->output;
1989 packet_get_newkeys(int mode)
1991 return (void *)active_state->newkeys[mode];
1995 * Save the state for the real connection, and use a separate state when
1996 * resuming a suspended connection.
1999 packet_backup_state(void)
2001 struct session_state *tmp;
2003 close(active_state->connection_in);
2004 active_state->connection_in = -1;
2005 close(active_state->connection_out);
2006 active_state->connection_out = -1;
2010 tmp = alloc_session_state();
2011 backup_state = active_state;
2016 * Swap in the old state when resuming a connecion.
2019 packet_restore_state(void)
2021 struct session_state *tmp;
2026 backup_state = active_state;
2028 active_state->connection_in = backup_state->connection_in;
2029 backup_state->connection_in = -1;
2030 active_state->connection_out = backup_state->connection_out;
2031 backup_state->connection_out = -1;
2032 len = buffer_len(&backup_state->input);
2034 buf = buffer_ptr(&backup_state->input);
2035 buffer_append(&active_state->input, buf, len);
2036 buffer_clear(&backup_state->input);
2037 add_recv_bytes(len);
2041 #ifdef NONE_CIPHER_ENABLED
2043 packet_get_authentication_state(void)
2045 return (active_state->after_authentication);