1 /* $OpenBSD: packet.c,v 1.212 2015/05/01 07:10:01 djm Exp $ */
3 * Author: Tatu Ylonen <ylo@cs.hut.fi>
4 * Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
6 * This file contains code implementing the packet protocol and communication
7 * with the other side. This same code is used both on client and server side.
9 * As far as I am concerned, the code I have written for this software
10 * can be used freely for any purpose. Any derived versions of this
11 * software must be clearly marked as such, and if the derived work is
12 * incompatible with the protocol description in the RFC file, it must be
13 * called by a name other than "ssh" or "Secure Shell".
16 * SSH2 packet format added by Markus Friedl.
17 * Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
19 * Redistribution and use in source and binary forms, with or without
20 * modification, are permitted provided that the following conditions
22 * 1. Redistributions of source code must retain the above copyright
23 * notice, this list of conditions and the following disclaimer.
24 * 2. Redistributions in binary form must reproduce the above copyright
25 * notice, this list of conditions and the following disclaimer in the
26 * documentation and/or other materials provided with the distribution.
28 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
29 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
30 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
31 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
32 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
33 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
34 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
35 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
36 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
37 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 #include <sys/param.h> /* MIN roundup */
43 #include <sys/types.h>
44 #include "openbsd-compat/sys-queue.h"
45 #include <sys/socket.h>
46 #ifdef HAVE_SYS_TIME_H
47 # include <sys/time.h>
50 #include <netinet/in.h>
51 #include <netinet/ip.h>
52 #include <arpa/inet.h>
66 #include "buffer.h" /* typedefs XXX */
67 #include "key.h" /* typedefs XXX */
96 #define PACKET_MAX_SIZE (256 * 1024)
106 TAILQ_ENTRY(packet) next;
108 struct sshbuf *payload;
111 struct session_state {
113 * This variable contains the file descriptors used for
114 * communicating with the other side. connection_in is used for
115 * reading; connection_out for writing. These can be the same
116 * descriptor, in which case it is assumed to be a socket.
121 /* Protocol flags for the remote side. */
122 u_int remote_protocol_flags;
124 /* Encryption context for receiving data. Only used for decryption. */
125 struct sshcipher_ctx receive_context;
127 /* Encryption context for sending data. Only used for encryption. */
128 struct sshcipher_ctx send_context;
130 /* Buffer for raw input data from the socket. */
131 struct sshbuf *input;
133 /* Buffer for raw output data going to the socket. */
134 struct sshbuf *output;
136 /* Buffer for the partial outgoing packet being constructed. */
137 struct sshbuf *outgoing_packet;
139 /* Buffer for the incoming packet currently being processed. */
140 struct sshbuf *incoming_packet;
142 /* Scratch buffer for packet compression/decompression. */
143 struct sshbuf *compression_buffer;
145 /* Incoming/outgoing compression dictionaries */
146 z_stream compression_in_stream;
147 z_stream compression_out_stream;
148 int compression_in_started;
149 int compression_out_started;
150 int compression_in_failures;
151 int compression_out_failures;
154 * Flag indicating whether packet compression/decompression is
157 int packet_compression;
159 /* default maximum packet size */
160 u_int max_packet_size;
162 /* Flag indicating whether this module has been initialized. */
165 /* Set to true if the connection is interactive. */
166 int interactive_mode;
168 /* Set to true if we are the server side. */
171 /* Set to true if we are authenticated. */
172 int after_authentication;
174 int keep_alive_timeouts;
176 /* The maximum time that we will wait to send or receive a packet */
177 int packet_timeout_ms;
179 /* Session key information for Encryption and MAC */
180 struct newkeys *newkeys[MODE_MAX];
181 struct packet_state p_read, p_send;
183 /* Volume-based rekeying */
184 u_int64_t max_blocks_in, max_blocks_out;
185 u_int32_t rekey_limit;
187 /* Time-based rekeying */
188 u_int32_t rekey_interval; /* how often in seconds */
189 time_t rekey_time; /* time of last rekeying */
191 /* Session key for protocol v1 */
192 u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
195 /* roundup current message to extra_pad bytes */
198 /* XXX discard incoming data after MAC error */
199 u_int packet_discard;
200 struct sshmac *packet_discard_mac;
202 /* Used in packet_read_poll2() */
205 /* Used in packet_send2 */
208 /* Used in packet_set_interactive */
209 int set_interactive_called;
211 /* Used in packet_set_maxsize */
212 int set_maxsize_called;
214 /* One-off warning about weak ciphers */
215 int cipher_warning_done;
217 /* SSH1 CRC compensation attack detector */
218 struct deattack_ctx deattack;
220 TAILQ_HEAD(, packet) outgoing;
224 ssh_alloc_session_state(void)
226 struct ssh *ssh = NULL;
227 struct session_state *state = NULL;
229 if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
230 (state = calloc(1, sizeof(*state))) == NULL ||
231 (state->input = sshbuf_new()) == NULL ||
232 (state->output = sshbuf_new()) == NULL ||
233 (state->outgoing_packet = sshbuf_new()) == NULL ||
234 (state->incoming_packet = sshbuf_new()) == NULL)
236 TAILQ_INIT(&state->outgoing);
237 TAILQ_INIT(&ssh->private_keys);
238 TAILQ_INIT(&ssh->public_keys);
239 state->connection_in = -1;
240 state->connection_out = -1;
241 state->max_packet_size = 32768;
242 state->packet_timeout_ms = -1;
243 state->p_send.packets = state->p_read.packets = 0;
244 state->initialized = 1;
246 * ssh_packet_send2() needs to queue packets until
247 * we've done the initial key exchange.
254 sshbuf_free(state->input);
255 sshbuf_free(state->output);
256 sshbuf_free(state->incoming_packet);
257 sshbuf_free(state->outgoing_packet);
265 * Sets the descriptors used for communication. Disables encryption until
266 * packet_set_encryption_key is called.
269 ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
271 struct session_state *state;
272 const struct sshcipher *none = cipher_by_name("none");
276 error("%s: cannot load cipher 'none'", __func__);
280 ssh = ssh_alloc_session_state();
282 error("%s: cound not allocate state", __func__);
286 state->connection_in = fd_in;
287 state->connection_out = fd_out;
288 if ((r = cipher_init(&state->send_context, none,
289 (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
290 (r = cipher_init(&state->receive_context, none,
291 (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
292 error("%s: cipher_init failed: %s", __func__, ssh_err(r));
296 state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
297 deattack_init(&state->deattack);
299 * Cache the IP address of the remote connection for use in error
300 * messages that might be generated after the connection has closed.
302 (void)ssh_remote_ipaddr(ssh);
307 ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
309 struct session_state *state = ssh->state;
311 if (timeout <= 0 || count <= 0) {
312 state->packet_timeout_ms = -1;
315 if ((INT_MAX / 1000) / count < timeout)
316 state->packet_timeout_ms = INT_MAX;
318 state->packet_timeout_ms = timeout * count * 1000;
322 ssh_packet_stop_discard(struct ssh *ssh)
324 struct session_state *state = ssh->state;
327 if (state->packet_discard_mac) {
330 memset(buf, 'a', sizeof(buf));
331 while (sshbuf_len(state->incoming_packet) <
333 if ((r = sshbuf_put(state->incoming_packet, buf,
336 (void) mac_compute(state->packet_discard_mac,
338 sshbuf_ptr(state->incoming_packet), PACKET_MAX_SIZE,
341 logit("Finished discarding for %.200s", ssh_remote_ipaddr(ssh));
342 return SSH_ERR_MAC_INVALID;
346 ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
347 struct sshmac *mac, u_int packet_length, u_int discard)
349 struct session_state *state = ssh->state;
352 if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
353 if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
355 return SSH_ERR_MAC_INVALID;
357 if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled)
358 state->packet_discard_mac = mac;
359 if (sshbuf_len(state->input) >= discard &&
360 (r = ssh_packet_stop_discard(ssh)) != 0)
362 state->packet_discard = discard - sshbuf_len(state->input);
366 /* Returns 1 if remote host is connected via socket, 0 if not. */
369 ssh_packet_connection_is_on_socket(struct ssh *ssh)
371 struct session_state *state = ssh->state;
372 struct sockaddr_storage from, to;
373 socklen_t fromlen, tolen;
375 /* filedescriptors in and out are the same, so it's a socket */
376 if (state->connection_in == state->connection_out)
378 fromlen = sizeof(from);
379 memset(&from, 0, sizeof(from));
380 if (getpeername(state->connection_in, (struct sockaddr *)&from,
384 memset(&to, 0, sizeof(to));
385 if (getpeername(state->connection_out, (struct sockaddr *)&to,
388 if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
390 if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
396 ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
399 *ibytes = ssh->state->p_read.bytes;
401 *obytes = ssh->state->p_send.bytes;
405 ssh_packet_connection_af(struct ssh *ssh)
407 struct sockaddr_storage to;
408 socklen_t tolen = sizeof(to);
410 memset(&to, 0, sizeof(to));
411 if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
415 if (to.ss_family == AF_INET6 &&
416 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr))
422 /* Sets the connection into non-blocking mode. */
425 ssh_packet_set_nonblocking(struct ssh *ssh)
427 /* Set the socket into non-blocking mode. */
428 set_nonblock(ssh->state->connection_in);
430 if (ssh->state->connection_out != ssh->state->connection_in)
431 set_nonblock(ssh->state->connection_out);
434 /* Returns the socket used for reading. */
437 ssh_packet_get_connection_in(struct ssh *ssh)
439 return ssh->state->connection_in;
442 /* Returns the descriptor used for writing. */
445 ssh_packet_get_connection_out(struct ssh *ssh)
447 return ssh->state->connection_out;
451 * Returns the IP-address of the remote host as a string. The returned
452 * string must not be freed.
456 ssh_remote_ipaddr(struct ssh *ssh)
458 /* Check whether we have cached the ipaddr. */
459 if (ssh->remote_ipaddr == NULL)
460 ssh->remote_ipaddr = ssh_packet_connection_is_on_socket(ssh) ?
461 get_peer_ipaddr(ssh->state->connection_in) :
463 if (ssh->remote_ipaddr == NULL)
465 return ssh->remote_ipaddr;
468 /* Closes the connection and clears and frees internal data structures. */
471 ssh_packet_close(struct ssh *ssh)
473 struct session_state *state = ssh->state;
477 if (!state->initialized)
479 state->initialized = 0;
480 if (state->connection_in == state->connection_out) {
481 shutdown(state->connection_out, SHUT_RDWR);
482 close(state->connection_out);
484 close(state->connection_in);
485 close(state->connection_out);
487 sshbuf_free(state->input);
488 sshbuf_free(state->output);
489 sshbuf_free(state->outgoing_packet);
490 sshbuf_free(state->incoming_packet);
491 for (mode = 0; mode < MODE_MAX; mode++)
492 kex_free_newkeys(state->newkeys[mode]);
493 if (state->compression_buffer) {
494 sshbuf_free(state->compression_buffer);
495 if (state->compression_out_started) {
496 z_streamp stream = &state->compression_out_stream;
497 debug("compress outgoing: "
498 "raw data %llu, compressed %llu, factor %.2f",
499 (unsigned long long)stream->total_in,
500 (unsigned long long)stream->total_out,
501 stream->total_in == 0 ? 0.0 :
502 (double) stream->total_out / stream->total_in);
503 if (state->compression_out_failures == 0)
506 if (state->compression_in_started) {
507 z_streamp stream = &state->compression_out_stream;
508 debug("compress incoming: "
509 "raw data %llu, compressed %llu, factor %.2f",
510 (unsigned long long)stream->total_out,
511 (unsigned long long)stream->total_in,
512 stream->total_out == 0 ? 0.0 :
513 (double) stream->total_in / stream->total_out);
514 if (state->compression_in_failures == 0)
518 if ((r = cipher_cleanup(&state->send_context)) != 0)
519 error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
520 if ((r = cipher_cleanup(&state->receive_context)) != 0)
521 error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
522 if (ssh->remote_ipaddr) {
523 free(ssh->remote_ipaddr);
524 ssh->remote_ipaddr = NULL;
530 /* Sets remote side protocol flags. */
533 ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
535 ssh->state->remote_protocol_flags = protocol_flags;
538 /* Returns the remote protocol flags set earlier by the above function. */
541 ssh_packet_get_protocol_flags(struct ssh *ssh)
543 return ssh->state->remote_protocol_flags;
547 * Starts packet compression from the next packet on in both directions.
548 * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
552 ssh_packet_init_compression(struct ssh *ssh)
554 if (!ssh->state->compression_buffer &&
555 ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
556 return SSH_ERR_ALLOC_FAIL;
561 start_compression_out(struct ssh *ssh, int level)
563 if (level < 1 || level > 9)
564 return SSH_ERR_INVALID_ARGUMENT;
565 debug("Enabling compression at level %d.", level);
566 if (ssh->state->compression_out_started == 1)
567 deflateEnd(&ssh->state->compression_out_stream);
568 switch (deflateInit(&ssh->state->compression_out_stream, level)) {
570 ssh->state->compression_out_started = 1;
573 return SSH_ERR_ALLOC_FAIL;
575 return SSH_ERR_INTERNAL_ERROR;
581 start_compression_in(struct ssh *ssh)
583 if (ssh->state->compression_in_started == 1)
584 inflateEnd(&ssh->state->compression_in_stream);
585 switch (inflateInit(&ssh->state->compression_in_stream)) {
587 ssh->state->compression_in_started = 1;
590 return SSH_ERR_ALLOC_FAIL;
592 return SSH_ERR_INTERNAL_ERROR;
598 ssh_packet_start_compression(struct ssh *ssh, int level)
602 if (ssh->state->packet_compression && !compat20)
603 return SSH_ERR_INTERNAL_ERROR;
604 ssh->state->packet_compression = 1;
605 if ((r = ssh_packet_init_compression(ssh)) != 0 ||
606 (r = start_compression_in(ssh)) != 0 ||
607 (r = start_compression_out(ssh, level)) != 0)
612 /* XXX remove need for separate compression buffer */
614 compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
619 if (ssh->state->compression_out_started != 1)
620 return SSH_ERR_INTERNAL_ERROR;
622 /* This case is not handled below. */
623 if (sshbuf_len(in) == 0)
626 /* Input is the contents of the input buffer. */
627 if ((ssh->state->compression_out_stream.next_in =
628 sshbuf_mutable_ptr(in)) == NULL)
629 return SSH_ERR_INTERNAL_ERROR;
630 ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
632 /* Loop compressing until deflate() returns with avail_out != 0. */
634 /* Set up fixed-size output buffer. */
635 ssh->state->compression_out_stream.next_out = buf;
636 ssh->state->compression_out_stream.avail_out = sizeof(buf);
638 /* Compress as much data into the buffer as possible. */
639 status = deflate(&ssh->state->compression_out_stream,
643 return SSH_ERR_ALLOC_FAIL;
645 /* Append compressed data to output_buffer. */
646 if ((r = sshbuf_put(out, buf, sizeof(buf) -
647 ssh->state->compression_out_stream.avail_out)) != 0)
652 ssh->state->compression_out_failures++;
653 return SSH_ERR_INVALID_FORMAT;
655 } while (ssh->state->compression_out_stream.avail_out == 0);
660 uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
665 if (ssh->state->compression_in_started != 1)
666 return SSH_ERR_INTERNAL_ERROR;
668 if ((ssh->state->compression_in_stream.next_in =
669 sshbuf_mutable_ptr(in)) == NULL)
670 return SSH_ERR_INTERNAL_ERROR;
671 ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
674 /* Set up fixed-size output buffer. */
675 ssh->state->compression_in_stream.next_out = buf;
676 ssh->state->compression_in_stream.avail_out = sizeof(buf);
678 status = inflate(&ssh->state->compression_in_stream,
682 if ((r = sshbuf_put(out, buf, sizeof(buf) -
683 ssh->state->compression_in_stream.avail_out)) != 0)
688 * Comments in zlib.h say that we should keep calling
689 * inflate() until we get an error. This appears to
690 * be the error that we get.
694 return SSH_ERR_INVALID_FORMAT;
696 return SSH_ERR_ALLOC_FAIL;
699 ssh->state->compression_in_failures++;
700 return SSH_ERR_INTERNAL_ERROR;
706 /* Serialise compression state into a blob for privsep */
708 ssh_packet_get_compress_state(struct sshbuf *m, struct ssh *ssh)
710 struct session_state *state = ssh->state;
714 if ((b = sshbuf_new()) == NULL)
715 return SSH_ERR_ALLOC_FAIL;
716 if (state->compression_in_started) {
717 if ((r = sshbuf_put_string(b, &state->compression_in_stream,
718 sizeof(state->compression_in_stream))) != 0)
720 } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
722 if (state->compression_out_started) {
723 if ((r = sshbuf_put_string(b, &state->compression_out_stream,
724 sizeof(state->compression_out_stream))) != 0)
726 } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
728 r = sshbuf_put_stringb(m, b);
734 /* Deserialise compression state from a blob for privsep */
736 ssh_packet_set_compress_state(struct ssh *ssh, struct sshbuf *m)
738 struct session_state *state = ssh->state;
739 struct sshbuf *b = NULL;
741 const u_char *inblob, *outblob;
744 if ((r = sshbuf_froms(m, &b)) != 0)
746 if ((r = sshbuf_get_string_direct(b, &inblob, &inl)) != 0 ||
747 (r = sshbuf_get_string_direct(b, &outblob, &outl)) != 0)
750 state->compression_in_started = 0;
751 else if (inl != sizeof(state->compression_in_stream)) {
752 r = SSH_ERR_INTERNAL_ERROR;
755 state->compression_in_started = 1;
756 memcpy(&state->compression_in_stream, inblob, inl);
759 state->compression_out_started = 0;
760 else if (outl != sizeof(state->compression_out_stream)) {
761 r = SSH_ERR_INTERNAL_ERROR;
764 state->compression_out_started = 1;
765 memcpy(&state->compression_out_stream, outblob, outl);
774 ssh_packet_set_compress_hooks(struct ssh *ssh, void *ctx,
775 void *(*allocfunc)(void *, u_int, u_int),
776 void (*freefunc)(void *, void *))
778 ssh->state->compression_out_stream.zalloc = (alloc_func)allocfunc;
779 ssh->state->compression_out_stream.zfree = (free_func)freefunc;
780 ssh->state->compression_out_stream.opaque = ctx;
781 ssh->state->compression_in_stream.zalloc = (alloc_func)allocfunc;
782 ssh->state->compression_in_stream.zfree = (free_func)freefunc;
783 ssh->state->compression_in_stream.opaque = ctx;
787 * Causes any further packets to be encrypted using the given key. The same
788 * key is used for both sending and reception. However, both directions are
789 * encrypted independently of each other.
793 ssh_packet_set_encryption_key(struct ssh *ssh, const u_char *key, u_int keylen, int number)
796 fatal("no SSH protocol 1 support");
797 #else /* WITH_SSH1 */
798 struct session_state *state = ssh->state;
799 const struct sshcipher *cipher = cipher_by_number(number);
804 fatal("%s: unknown cipher number %d", __func__, number);
806 fatal("%s: keylen too small: %d", __func__, keylen);
807 if (keylen > SSH_SESSION_KEY_LENGTH)
808 fatal("%s: keylen too big: %d", __func__, keylen);
809 memcpy(state->ssh1_key, key, keylen);
810 state->ssh1_keylen = keylen;
811 if ((r = cipher_init(&state->send_context, cipher, key, keylen,
812 NULL, 0, CIPHER_ENCRYPT)) != 0 ||
813 (r = cipher_init(&state->receive_context, cipher, key, keylen,
814 NULL, 0, CIPHER_DECRYPT) != 0))
815 fatal("%s: cipher_init failed: %s", __func__, ssh_err(r));
816 if (!state->cipher_warning_done &&
817 ((wmsg = cipher_warning_message(&state->send_context)) != NULL ||
818 (wmsg = cipher_warning_message(&state->send_context)) != NULL)) {
819 error("Warning: %s", wmsg);
820 state->cipher_warning_done = 1;
822 #endif /* WITH_SSH1 */
826 * Finalizes and sends the packet. If the encryption key has been set,
827 * encrypts the packet before sending.
831 ssh_packet_send1(struct ssh *ssh)
833 struct session_state *state = ssh->state;
839 * If using packet compression, compress the payload of the outgoing
842 if (state->packet_compression) {
843 sshbuf_reset(state->compression_buffer);
845 if ((r = sshbuf_consume(state->outgoing_packet, 8)) != 0)
848 if ((r = sshbuf_put(state->compression_buffer,
849 "\0\0\0\0\0\0\0\0", 8)) != 0)
851 if ((r = compress_buffer(ssh, state->outgoing_packet,
852 state->compression_buffer)) != 0)
854 sshbuf_reset(state->outgoing_packet);
855 if ((r = sshbuf_putb(state->outgoing_packet,
856 state->compression_buffer)) != 0)
859 /* Compute packet length without padding (add checksum, remove padding). */
860 len = sshbuf_len(state->outgoing_packet) + 4 - 8;
862 /* Insert padding. Initialized to zero in packet_start1() */
863 padding = 8 - len % 8;
864 if (!state->send_context.plaintext) {
865 cp = sshbuf_mutable_ptr(state->outgoing_packet);
867 r = SSH_ERR_INTERNAL_ERROR;
870 arc4random_buf(cp + 8 - padding, padding);
872 if ((r = sshbuf_consume(state->outgoing_packet, 8 - padding)) != 0)
875 /* Add check bytes. */
876 checksum = ssh_crc32(sshbuf_ptr(state->outgoing_packet),
877 sshbuf_len(state->outgoing_packet));
878 POKE_U32(buf, checksum);
879 if ((r = sshbuf_put(state->outgoing_packet, buf, 4)) != 0)
883 fprintf(stderr, "packet_send plain: ");
884 sshbuf_dump(state->outgoing_packet, stderr);
887 /* Append to output. */
889 if ((r = sshbuf_put(state->output, buf, 4)) != 0)
891 if ((r = sshbuf_reserve(state->output,
892 sshbuf_len(state->outgoing_packet), &cp)) != 0)
894 if ((r = cipher_crypt(&state->send_context, 0, cp,
895 sshbuf_ptr(state->outgoing_packet),
896 sshbuf_len(state->outgoing_packet), 0, 0)) != 0)
900 fprintf(stderr, "encrypted: ");
901 sshbuf_dump(state->output, stderr);
903 state->p_send.packets++;
904 state->p_send.bytes += len +
905 sshbuf_len(state->outgoing_packet);
906 sshbuf_reset(state->outgoing_packet);
909 * Note that the packet is now only buffered in output. It won't be
910 * actually sent until ssh_packet_write_wait or ssh_packet_write_poll
919 ssh_set_newkeys(struct ssh *ssh, int mode)
921 struct session_state *state = ssh->state;
924 struct sshcomp *comp;
925 struct sshcipher_ctx *cc;
926 u_int64_t *max_blocks;
930 debug2("set_newkeys: mode %d", mode);
932 if (mode == MODE_OUT) {
933 cc = &state->send_context;
934 crypt_type = CIPHER_ENCRYPT;
935 state->p_send.packets = state->p_send.blocks = 0;
936 max_blocks = &state->max_blocks_out;
938 cc = &state->receive_context;
939 crypt_type = CIPHER_DECRYPT;
940 state->p_read.packets = state->p_read.blocks = 0;
941 max_blocks = &state->max_blocks_in;
943 if (state->newkeys[mode] != NULL) {
944 debug("set_newkeys: rekeying");
945 if ((r = cipher_cleanup(cc)) != 0)
947 enc = &state->newkeys[mode]->enc;
948 mac = &state->newkeys[mode]->mac;
949 comp = &state->newkeys[mode]->comp;
951 explicit_bzero(enc->iv, enc->iv_len);
952 explicit_bzero(enc->key, enc->key_len);
953 explicit_bzero(mac->key, mac->key_len);
960 free(state->newkeys[mode]);
962 /* move newkeys from kex to state */
963 if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
964 return SSH_ERR_INTERNAL_ERROR;
965 ssh->kex->newkeys[mode] = NULL;
966 enc = &state->newkeys[mode]->enc;
967 mac = &state->newkeys[mode]->mac;
968 comp = &state->newkeys[mode]->comp;
969 if (cipher_authlen(enc->cipher) == 0) {
970 if ((r = mac_init(mac)) != 0)
974 DBG(debug("cipher_init_context: %d", mode));
975 if ((r = cipher_init(cc, enc->cipher, enc->key, enc->key_len,
976 enc->iv, enc->iv_len, crypt_type)) != 0)
978 if (!state->cipher_warning_done &&
979 (wmsg = cipher_warning_message(cc)) != NULL) {
980 error("Warning: %s", wmsg);
981 state->cipher_warning_done = 1;
983 /* Deleting the keys does not gain extra security */
984 /* explicit_bzero(enc->iv, enc->block_size);
985 explicit_bzero(enc->key, enc->key_len);
986 explicit_bzero(mac->key, mac->key_len); */
987 if ((comp->type == COMP_ZLIB ||
988 (comp->type == COMP_DELAYED &&
989 state->after_authentication)) && comp->enabled == 0) {
990 if ((r = ssh_packet_init_compression(ssh)) < 0)
992 if (mode == MODE_OUT) {
993 if ((r = start_compression_out(ssh, 6)) != 0)
996 if ((r = start_compression_in(ssh)) != 0)
1002 * The 2^(blocksize*2) limit is too expensive for 3DES,
1003 * blowfish, etc, so enforce a 1GB limit for small blocksizes.
1005 if (enc->block_size >= 16)
1006 *max_blocks = (u_int64_t)1 << (enc->block_size*2);
1008 *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1009 if (state->rekey_limit)
1010 *max_blocks = MIN(*max_blocks,
1011 state->rekey_limit / enc->block_size);
1016 * Delayed compression for SSH2 is enabled after authentication:
1017 * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1018 * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
1021 ssh_packet_enable_delayed_compress(struct ssh *ssh)
1023 struct session_state *state = ssh->state;
1024 struct sshcomp *comp = NULL;
1028 * Remember that we are past the authentication step, so rekeying
1029 * with COMP_DELAYED will turn on compression immediately.
1031 state->after_authentication = 1;
1032 for (mode = 0; mode < MODE_MAX; mode++) {
1033 /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1034 if (state->newkeys[mode] == NULL)
1036 comp = &state->newkeys[mode]->comp;
1037 if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1038 if ((r = ssh_packet_init_compression(ssh)) != 0)
1040 if (mode == MODE_OUT) {
1041 if ((r = start_compression_out(ssh, 6)) != 0)
1044 if ((r = start_compression_in(ssh)) != 0)
1054 * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1057 ssh_packet_send2_wrapped(struct ssh *ssh)
1059 struct session_state *state = ssh->state;
1060 u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1061 u_char padlen, pad = 0;
1062 u_int authlen = 0, aadlen = 0;
1064 struct sshenc *enc = NULL;
1065 struct sshmac *mac = NULL;
1066 struct sshcomp *comp = NULL;
1069 if (state->newkeys[MODE_OUT] != NULL) {
1070 enc = &state->newkeys[MODE_OUT]->enc;
1071 mac = &state->newkeys[MODE_OUT]->mac;
1072 comp = &state->newkeys[MODE_OUT]->comp;
1073 /* disable mac for authenticated encryption */
1074 if ((authlen = cipher_authlen(enc->cipher)) != 0)
1077 block_size = enc ? enc->block_size : 8;
1078 aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1080 type = (sshbuf_ptr(state->outgoing_packet))[5];
1083 fprintf(stderr, "plain: ");
1084 sshbuf_dump(state->outgoing_packet, stderr);
1087 if (comp && comp->enabled) {
1088 len = sshbuf_len(state->outgoing_packet);
1089 /* skip header, compress only payload */
1090 if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1092 sshbuf_reset(state->compression_buffer);
1093 if ((r = compress_buffer(ssh, state->outgoing_packet,
1094 state->compression_buffer)) != 0)
1096 sshbuf_reset(state->outgoing_packet);
1097 if ((r = sshbuf_put(state->outgoing_packet,
1098 "\0\0\0\0\0", 5)) != 0 ||
1099 (r = sshbuf_putb(state->outgoing_packet,
1100 state->compression_buffer)) != 0)
1102 DBG(debug("compression: raw %d compressed %zd", len,
1103 sshbuf_len(state->outgoing_packet)));
1106 /* sizeof (packet_len + pad_len + payload) */
1107 len = sshbuf_len(state->outgoing_packet);
1110 * calc size of padding, alloc space, get random data,
1111 * minimum padding is 4 bytes
1113 len -= aadlen; /* packet length is not encrypted for EtM modes */
1114 padlen = block_size - (len % block_size);
1116 padlen += block_size;
1117 if (state->extra_pad) {
1118 /* will wrap if extra_pad+padlen > 255 */
1120 roundup(state->extra_pad, block_size);
1121 pad = state->extra_pad -
1122 ((len + padlen) % state->extra_pad);
1123 DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1124 __func__, pad, len, padlen, state->extra_pad));
1126 state->extra_pad = 0;
1128 if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1130 if (enc && !state->send_context.plaintext) {
1131 /* random padding */
1132 arc4random_buf(cp, padlen);
1135 explicit_bzero(cp, padlen);
1137 /* sizeof (packet_len + pad_len + payload + padding) */
1138 len = sshbuf_len(state->outgoing_packet);
1139 cp = sshbuf_mutable_ptr(state->outgoing_packet);
1141 r = SSH_ERR_INTERNAL_ERROR;
1144 /* packet_length includes payload, padding and padding length field */
1145 POKE_U32(cp, len - 4);
1147 DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1148 len, padlen, aadlen));
1150 /* compute MAC over seqnr and packet(length fields, payload, padding) */
1151 if (mac && mac->enabled && !mac->etm) {
1152 if ((r = mac_compute(mac, state->p_send.seqnr,
1153 sshbuf_ptr(state->outgoing_packet), len,
1154 macbuf, sizeof(macbuf))) != 0)
1156 DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1158 /* encrypt packet and append to output buffer. */
1159 if ((r = sshbuf_reserve(state->output,
1160 sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1162 if ((r = cipher_crypt(&state->send_context, state->p_send.seqnr, cp,
1163 sshbuf_ptr(state->outgoing_packet),
1164 len - aadlen, aadlen, authlen)) != 0)
1166 /* append unencrypted MAC */
1167 if (mac && mac->enabled) {
1169 /* EtM: compute mac over aadlen + cipher text */
1170 if ((r = mac_compute(mac, state->p_send.seqnr,
1171 cp, len, macbuf, sizeof(macbuf))) != 0)
1173 DBG(debug("done calc MAC(EtM) out #%d",
1174 state->p_send.seqnr));
1176 if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1180 fprintf(stderr, "encrypted: ");
1181 sshbuf_dump(state->output, stderr);
1183 /* increment sequence number for outgoing packets */
1184 if (++state->p_send.seqnr == 0)
1185 logit("outgoing seqnr wraps around");
1186 if (++state->p_send.packets == 0)
1187 if (!(ssh->compat & SSH_BUG_NOREKEY))
1188 return SSH_ERR_NEED_REKEY;
1189 state->p_send.blocks += len / block_size;
1190 state->p_send.bytes += len;
1191 sshbuf_reset(state->outgoing_packet);
1193 if (type == SSH2_MSG_NEWKEYS)
1194 r = ssh_set_newkeys(ssh, MODE_OUT);
1195 else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1196 r = ssh_packet_enable_delayed_compress(ssh);
1204 ssh_packet_send2(struct ssh *ssh)
1206 struct session_state *state = ssh->state;
1211 type = sshbuf_ptr(state->outgoing_packet)[5];
1213 /* during rekeying we can only send key exchange messages */
1214 if (state->rekeying) {
1215 if ((type < SSH2_MSG_TRANSPORT_MIN) ||
1216 (type > SSH2_MSG_TRANSPORT_MAX) ||
1217 (type == SSH2_MSG_SERVICE_REQUEST) ||
1218 (type == SSH2_MSG_SERVICE_ACCEPT)) {
1219 debug("enqueue packet: %u", type);
1220 p = calloc(1, sizeof(*p));
1222 return SSH_ERR_ALLOC_FAIL;
1224 p->payload = state->outgoing_packet;
1225 TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1226 state->outgoing_packet = sshbuf_new();
1227 if (state->outgoing_packet == NULL)
1228 return SSH_ERR_ALLOC_FAIL;
1233 /* rekeying starts with sending KEXINIT */
1234 if (type == SSH2_MSG_KEXINIT)
1235 state->rekeying = 1;
1237 if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1240 /* after a NEWKEYS message we can send the complete queue */
1241 if (type == SSH2_MSG_NEWKEYS) {
1242 state->rekeying = 0;
1243 state->rekey_time = monotime();
1244 while ((p = TAILQ_FIRST(&state->outgoing))) {
1246 debug("dequeue packet: %u", type);
1247 sshbuf_free(state->outgoing_packet);
1248 state->outgoing_packet = p->payload;
1249 TAILQ_REMOVE(&state->outgoing, p, next);
1251 if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1259 * Waits until a packet has been received, and returns its type. Note that
1260 * no other data is processed until this returns, so this function should not
1261 * be used during the interactive session.
1265 ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1267 struct session_state *state = ssh->state;
1268 int len, r, ms_remain, cont;
1271 struct timeval timeout, start, *timeoutp = NULL;
1273 DBG(debug("packet_read()"));
1275 setp = (fd_set *)calloc(howmany(state->connection_in + 1,
1276 NFDBITS), sizeof(fd_mask));
1278 return SSH_ERR_ALLOC_FAIL;
1281 * Since we are blocking, ensure that all written packets have
1284 if ((r = ssh_packet_write_wait(ssh)) != 0)
1287 /* Stay in the loop until we have received a complete packet. */
1289 /* Try to read a packet from the buffer. */
1290 r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1294 *typep == SSH_SMSG_SUCCESS
1295 || *typep == SSH_SMSG_FAILURE
1296 || *typep == SSH_CMSG_EOF
1297 || *typep == SSH_CMSG_EXIT_CONFIRMATION))
1298 if ((r = sshpkt_get_end(ssh)) != 0)
1300 /* If we got a packet, return it. */
1301 if (*typep != SSH_MSG_NONE)
1304 * Otherwise, wait for some data to arrive, add it to the
1305 * buffer, and try again.
1307 memset(setp, 0, howmany(state->connection_in + 1,
1308 NFDBITS) * sizeof(fd_mask));
1309 FD_SET(state->connection_in, setp);
1311 if (state->packet_timeout_ms > 0) {
1312 ms_remain = state->packet_timeout_ms;
1313 timeoutp = &timeout;
1315 /* Wait for some data to arrive. */
1317 if (state->packet_timeout_ms != -1) {
1318 ms_to_timeval(&timeout, ms_remain);
1319 gettimeofday(&start, NULL);
1321 if ((r = select(state->connection_in + 1, setp,
1322 NULL, NULL, timeoutp)) >= 0)
1324 if (errno != EAGAIN && errno != EINTR &&
1325 errno != EWOULDBLOCK)
1327 if (state->packet_timeout_ms == -1)
1329 ms_subtract_diff(&start, &ms_remain);
1330 if (ms_remain <= 0) {
1336 return SSH_ERR_CONN_TIMEOUT;
1337 /* Read data from the socket. */
1340 len = roaming_read(state->connection_in, buf,
1341 sizeof(buf), &cont);
1342 } while (len == 0 && cont);
1344 r = SSH_ERR_CONN_CLOSED;
1348 r = SSH_ERR_SYSTEM_ERROR;
1352 /* Append it to the buffer. */
1353 if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1362 ssh_packet_read(struct ssh *ssh)
1367 if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1368 fatal("%s: %s", __func__, ssh_err(r));
1373 * Waits until a packet has been received, verifies that its type matches
1374 * that given, and gives a fatal error and exits if there is a mismatch.
1378 ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1383 if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1385 if (type != expected_type) {
1386 if ((r = sshpkt_disconnect(ssh,
1387 "Protocol error: expected packet type %d, got %d",
1388 expected_type, type)) != 0)
1390 return SSH_ERR_PROTOCOL_ERROR;
1395 /* Checks if a full packet is available in the data received so far via
1396 * packet_process_incoming. If so, reads the packet; otherwise returns
1397 * SSH_MSG_NONE. This does not wait for data from the connection.
1399 * SSH_MSG_DISCONNECT is handled specially here. Also,
1400 * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1405 ssh_packet_read_poll1(struct ssh *ssh, u_char *typep)
1407 struct session_state *state = ssh->state;
1408 u_int len, padded_len;
1412 u_int checksum, stored_checksum;
1415 *typep = SSH_MSG_NONE;
1417 /* Check if input size is less than minimum packet size. */
1418 if (sshbuf_len(state->input) < 4 + 8)
1420 /* Get length of incoming packet. */
1421 len = PEEK_U32(sshbuf_ptr(state->input));
1422 if (len < 1 + 2 + 2 || len > 256 * 1024) {
1423 if ((r = sshpkt_disconnect(ssh, "Bad packet length %u",
1426 return SSH_ERR_CONN_CORRUPT;
1428 padded_len = (len + 8) & ~7;
1430 /* Check if the packet has been entirely received. */
1431 if (sshbuf_len(state->input) < 4 + padded_len)
1434 /* The entire packet is in buffer. */
1436 /* Consume packet length. */
1437 if ((r = sshbuf_consume(state->input, 4)) != 0)
1441 * Cryptographic attack detector for ssh
1442 * (C)1998 CORE-SDI, Buenos Aires Argentina
1443 * Ariel Futoransky(futo@core-sdi.com)
1445 if (!state->receive_context.plaintext) {
1447 switch (detect_attack(&state->deattack,
1448 sshbuf_ptr(state->input), padded_len)) {
1451 case DEATTACK_DETECTED:
1452 emsg = "crc32 compensation attack detected";
1454 case DEATTACK_DOS_DETECTED:
1455 emsg = "deattack denial of service detected";
1458 emsg = "deattack error";
1463 if ((r = sshpkt_disconnect(ssh, "%s", emsg)) != 0 ||
1464 (r = ssh_packet_write_wait(ssh)) != 0)
1466 return SSH_ERR_CONN_CORRUPT;
1470 /* Decrypt data to incoming_packet. */
1471 sshbuf_reset(state->incoming_packet);
1472 if ((r = sshbuf_reserve(state->incoming_packet, padded_len, &p)) != 0)
1474 if ((r = cipher_crypt(&state->receive_context, 0, p,
1475 sshbuf_ptr(state->input), padded_len, 0, 0)) != 0)
1478 if ((r = sshbuf_consume(state->input, padded_len)) != 0)
1482 fprintf(stderr, "read_poll plain: ");
1483 sshbuf_dump(state->incoming_packet, stderr);
1486 /* Compute packet checksum. */
1487 checksum = ssh_crc32(sshbuf_ptr(state->incoming_packet),
1488 sshbuf_len(state->incoming_packet) - 4);
1491 if ((r = sshbuf_consume(state->incoming_packet, 8 - len % 8)) != 0)
1494 /* Test check bytes. */
1495 if (len != sshbuf_len(state->incoming_packet)) {
1496 error("%s: len %d != sshbuf_len %zd", __func__,
1497 len, sshbuf_len(state->incoming_packet));
1498 if ((r = sshpkt_disconnect(ssh, "invalid packet length")) != 0 ||
1499 (r = ssh_packet_write_wait(ssh)) != 0)
1501 return SSH_ERR_CONN_CORRUPT;
1504 cp = sshbuf_ptr(state->incoming_packet) + len - 4;
1505 stored_checksum = PEEK_U32(cp);
1506 if (checksum != stored_checksum) {
1507 error("Corrupted check bytes on input");
1508 if ((r = sshpkt_disconnect(ssh, "connection corrupted")) != 0 ||
1509 (r = ssh_packet_write_wait(ssh)) != 0)
1511 return SSH_ERR_CONN_CORRUPT;
1513 if ((r = sshbuf_consume_end(state->incoming_packet, 4)) < 0)
1516 if (state->packet_compression) {
1517 sshbuf_reset(state->compression_buffer);
1518 if ((r = uncompress_buffer(ssh, state->incoming_packet,
1519 state->compression_buffer)) != 0)
1521 sshbuf_reset(state->incoming_packet);
1522 if ((r = sshbuf_putb(state->incoming_packet,
1523 state->compression_buffer)) != 0)
1526 state->p_read.packets++;
1527 state->p_read.bytes += padded_len + 4;
1528 if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1530 if (*typep < SSH_MSG_MIN || *typep > SSH_MSG_MAX) {
1531 error("Invalid ssh1 packet type: %d", *typep);
1532 if ((r = sshpkt_disconnect(ssh, "invalid packet type")) != 0 ||
1533 (r = ssh_packet_write_wait(ssh)) != 0)
1535 return SSH_ERR_PROTOCOL_ERROR;
1543 ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1545 struct session_state *state = ssh->state;
1547 u_char *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1548 u_int maclen, aadlen = 0, authlen = 0, block_size;
1549 struct sshenc *enc = NULL;
1550 struct sshmac *mac = NULL;
1551 struct sshcomp *comp = NULL;
1554 *typep = SSH_MSG_NONE;
1556 if (state->packet_discard)
1559 if (state->newkeys[MODE_IN] != NULL) {
1560 enc = &state->newkeys[MODE_IN]->enc;
1561 mac = &state->newkeys[MODE_IN]->mac;
1562 comp = &state->newkeys[MODE_IN]->comp;
1563 /* disable mac for authenticated encryption */
1564 if ((authlen = cipher_authlen(enc->cipher)) != 0)
1567 maclen = mac && mac->enabled ? mac->mac_len : 0;
1568 block_size = enc ? enc->block_size : 8;
1569 aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1571 if (aadlen && state->packlen == 0) {
1572 if (cipher_get_length(&state->receive_context,
1573 &state->packlen, state->p_read.seqnr,
1574 sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1576 if (state->packlen < 1 + 4 ||
1577 state->packlen > PACKET_MAX_SIZE) {
1579 sshbuf_dump(state->input, stderr);
1581 logit("Bad packet length %u.", state->packlen);
1582 if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1585 sshbuf_reset(state->incoming_packet);
1586 } else if (state->packlen == 0) {
1588 * check if input size is less than the cipher block size,
1589 * decrypt first block and extract length of incoming packet
1591 if (sshbuf_len(state->input) < block_size)
1593 sshbuf_reset(state->incoming_packet);
1594 if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1597 if ((r = cipher_crypt(&state->receive_context,
1598 state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1599 block_size, 0, 0)) != 0)
1601 state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1602 if (state->packlen < 1 + 4 ||
1603 state->packlen > PACKET_MAX_SIZE) {
1605 fprintf(stderr, "input: \n");
1606 sshbuf_dump(state->input, stderr);
1607 fprintf(stderr, "incoming_packet: \n");
1608 sshbuf_dump(state->incoming_packet, stderr);
1610 logit("Bad packet length %u.", state->packlen);
1611 return ssh_packet_start_discard(ssh, enc, mac,
1612 state->packlen, PACKET_MAX_SIZE);
1614 if ((r = sshbuf_consume(state->input, block_size)) != 0)
1617 DBG(debug("input: packet len %u", state->packlen+4));
1620 /* only the payload is encrypted */
1621 need = state->packlen;
1624 * the payload size and the payload are encrypted, but we
1625 * have a partial packet of block_size bytes
1627 need = 4 + state->packlen - block_size;
1629 DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1630 " aadlen %d", block_size, need, maclen, authlen, aadlen));
1631 if (need % block_size != 0) {
1632 logit("padding error: need %d block %d mod %d",
1633 need, block_size, need % block_size);
1634 return ssh_packet_start_discard(ssh, enc, mac,
1635 state->packlen, PACKET_MAX_SIZE - block_size);
1638 * check if the entire packet has been received and
1639 * decrypt into incoming_packet:
1640 * 'aadlen' bytes are unencrypted, but authenticated.
1641 * 'need' bytes are encrypted, followed by either
1642 * 'authlen' bytes of authentication tag or
1643 * 'maclen' bytes of message authentication code.
1645 if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1648 fprintf(stderr, "read_poll enc/full: ");
1649 sshbuf_dump(state->input, stderr);
1651 /* EtM: compute mac over encrypted input */
1652 if (mac && mac->enabled && mac->etm) {
1653 if ((r = mac_compute(mac, state->p_read.seqnr,
1654 sshbuf_ptr(state->input), aadlen + need,
1655 macbuf, sizeof(macbuf))) != 0)
1658 if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1661 if ((r = cipher_crypt(&state->receive_context, state->p_read.seqnr, cp,
1662 sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1664 if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1667 * compute MAC over seqnr and packet,
1668 * increment sequence number for incoming packet
1670 if (mac && mac->enabled) {
1672 if ((r = mac_compute(mac, state->p_read.seqnr,
1673 sshbuf_ptr(state->incoming_packet),
1674 sshbuf_len(state->incoming_packet),
1675 macbuf, sizeof(macbuf))) != 0)
1677 if (timingsafe_bcmp(macbuf, sshbuf_ptr(state->input),
1678 mac->mac_len) != 0) {
1679 logit("Corrupted MAC on input.");
1680 if (need > PACKET_MAX_SIZE)
1681 return SSH_ERR_INTERNAL_ERROR;
1682 return ssh_packet_start_discard(ssh, enc, mac,
1683 state->packlen, PACKET_MAX_SIZE - need);
1686 DBG(debug("MAC #%d ok", state->p_read.seqnr));
1687 if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1690 if (seqnr_p != NULL)
1691 *seqnr_p = state->p_read.seqnr;
1692 if (++state->p_read.seqnr == 0)
1693 logit("incoming seqnr wraps around");
1694 if (++state->p_read.packets == 0)
1695 if (!(ssh->compat & SSH_BUG_NOREKEY))
1696 return SSH_ERR_NEED_REKEY;
1697 state->p_read.blocks += (state->packlen + 4) / block_size;
1698 state->p_read.bytes += state->packlen + 4;
1701 padlen = sshbuf_ptr(state->incoming_packet)[4];
1702 DBG(debug("input: padlen %d", padlen));
1704 if ((r = sshpkt_disconnect(ssh,
1705 "Corrupted padlen %d on input.", padlen)) != 0 ||
1706 (r = ssh_packet_write_wait(ssh)) != 0)
1708 return SSH_ERR_CONN_CORRUPT;
1711 /* skip packet size + padlen, discard padding */
1712 if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1713 ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1716 DBG(debug("input: len before de-compress %zd",
1717 sshbuf_len(state->incoming_packet)));
1718 if (comp && comp->enabled) {
1719 sshbuf_reset(state->compression_buffer);
1720 if ((r = uncompress_buffer(ssh, state->incoming_packet,
1721 state->compression_buffer)) != 0)
1723 sshbuf_reset(state->incoming_packet);
1724 if ((r = sshbuf_putb(state->incoming_packet,
1725 state->compression_buffer)) != 0)
1727 DBG(debug("input: len after de-compress %zd",
1728 sshbuf_len(state->incoming_packet)));
1731 * get packet type, implies consume.
1732 * return length of payload (without type field)
1734 if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1736 if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1737 if ((r = sshpkt_disconnect(ssh,
1738 "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1739 (r = ssh_packet_write_wait(ssh)) != 0)
1741 return SSH_ERR_PROTOCOL_ERROR;
1743 if (*typep == SSH2_MSG_NEWKEYS)
1744 r = ssh_set_newkeys(ssh, MODE_IN);
1745 else if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1746 r = ssh_packet_enable_delayed_compress(ssh);
1750 fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1751 sshbuf_dump(state->incoming_packet, stderr);
1753 /* reset for next packet */
1760 ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1762 struct session_state *state = ssh->state;
1763 u_int reason, seqnr;
1770 r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1774 state->keep_alive_timeouts = 0;
1775 DBG(debug("received packet type %d", *typep));
1778 case SSH2_MSG_IGNORE:
1779 debug3("Received SSH2_MSG_IGNORE");
1781 case SSH2_MSG_DEBUG:
1782 if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1783 (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1784 (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1789 debug("Remote: %.900s", msg);
1792 case SSH2_MSG_DISCONNECT:
1793 if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1794 (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1796 /* Ignore normal client exit notifications */
1797 do_log2(ssh->state->server_side &&
1798 reason == SSH2_DISCONNECT_BY_APPLICATION ?
1799 SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1800 "Received disconnect from %s: %u: %.400s",
1801 ssh_remote_ipaddr(ssh), reason, msg);
1803 return SSH_ERR_DISCONNECTED;
1804 case SSH2_MSG_UNIMPLEMENTED:
1805 if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1807 debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1814 r = ssh_packet_read_poll1(ssh, typep);
1817 return SSH_MSG_NONE;
1818 case SSH_MSG_IGNORE:
1821 if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1823 debug("Remote: %.900s", msg);
1826 case SSH_MSG_DISCONNECT:
1827 if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1829 error("Received disconnect from %s: %.400s",
1830 ssh_remote_ipaddr(ssh), msg);
1832 return SSH_ERR_DISCONNECTED;
1834 DBG(debug("received packet type %d", *typep));
1842 * Buffers the given amount of input characters. This is intended to be used
1843 * together with packet_read_poll.
1847 ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1849 struct session_state *state = ssh->state;
1852 if (state->packet_discard) {
1853 state->keep_alive_timeouts = 0; /* ?? */
1854 if (len >= state->packet_discard) {
1855 if ((r = ssh_packet_stop_discard(ssh)) != 0)
1858 state->packet_discard -= len;
1861 if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1868 ssh_packet_remaining(struct ssh *ssh)
1870 return sshbuf_len(ssh->state->incoming_packet);
1874 * Sends a diagnostic message from the server to the client. This message
1875 * can be sent at any time (but not while constructing another message). The
1876 * message is printed immediately, but only if the client is being executed
1877 * in verbose mode. These messages are primarily intended to ease debugging
1878 * authentication problems. The length of the formatted message must not
1879 * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1882 ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1888 if (compat20 && (ssh->compat & SSH_BUG_DEBUG))
1891 va_start(args, fmt);
1892 vsnprintf(buf, sizeof(buf), fmt, args);
1896 if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1897 (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1898 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1899 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1900 (r = sshpkt_send(ssh)) != 0)
1901 fatal("%s: %s", __func__, ssh_err(r));
1903 if ((r = sshpkt_start(ssh, SSH_MSG_DEBUG)) != 0 ||
1904 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1905 (r = sshpkt_send(ssh)) != 0)
1906 fatal("%s: %s", __func__, ssh_err(r));
1908 if ((r = ssh_packet_write_wait(ssh)) != 0)
1909 fatal("%s: %s", __func__, ssh_err(r));
1913 * Pretty-print connection-terminating errors and exit.
1916 sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
1919 case SSH_ERR_CONN_CLOSED:
1920 logit("Connection closed by %.200s", ssh_remote_ipaddr(ssh));
1922 case SSH_ERR_CONN_TIMEOUT:
1923 logit("Connection to %.200s timed out", ssh_remote_ipaddr(ssh));
1925 case SSH_ERR_DISCONNECTED:
1926 logit("Disconnected from %.200s",
1927 ssh_remote_ipaddr(ssh));
1929 case SSH_ERR_SYSTEM_ERROR:
1930 if (errno == ECONNRESET) {
1931 logit("Connection reset by %.200s",
1932 ssh_remote_ipaddr(ssh));
1937 fatal("%s%sConnection to %.200s: %s",
1938 tag != NULL ? tag : "", tag != NULL ? ": " : "",
1939 ssh_remote_ipaddr(ssh), ssh_err(r));
1944 * Logs the error plus constructs and sends a disconnect packet, closes the
1945 * connection, and exits. This function never returns. The error message
1946 * should not contain a newline. The length of the formatted message must
1947 * not exceed 1024 bytes.
1950 ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1954 static int disconnecting = 0;
1957 if (disconnecting) /* Guard against recursive invocations. */
1958 fatal("packet_disconnect called recursively.");
1962 * Format the message. Note that the caller must make sure the
1963 * message is of limited size.
1965 va_start(args, fmt);
1966 vsnprintf(buf, sizeof(buf), fmt, args);
1969 /* Display the error locally */
1970 logit("Disconnecting: %.100s", buf);
1973 * Send the disconnect message to the other side, and wait
1974 * for it to get sent.
1976 if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1977 sshpkt_fatal(ssh, __func__, r);
1979 if ((r = ssh_packet_write_wait(ssh)) != 0)
1980 sshpkt_fatal(ssh, __func__, r);
1982 /* Close the connection. */
1983 ssh_packet_close(ssh);
1988 * Checks if there is any buffered output, and tries to write some of
1992 ssh_packet_write_poll(struct ssh *ssh)
1994 struct session_state *state = ssh->state;
1995 int len = sshbuf_len(state->output);
2000 len = roaming_write(state->connection_out,
2001 sshbuf_ptr(state->output), len, &cont);
2003 if (errno == EINTR || errno == EAGAIN ||
2004 errno == EWOULDBLOCK)
2006 return SSH_ERR_SYSTEM_ERROR;
2008 if (len == 0 && !cont)
2009 return SSH_ERR_CONN_CLOSED;
2010 if ((r = sshbuf_consume(state->output, len)) != 0)
2017 * Calls packet_write_poll repeatedly until all pending output data has been
2021 ssh_packet_write_wait(struct ssh *ssh)
2024 int ret, r, ms_remain = 0;
2025 struct timeval start, timeout, *timeoutp = NULL;
2026 struct session_state *state = ssh->state;
2028 setp = (fd_set *)calloc(howmany(state->connection_out + 1,
2029 NFDBITS), sizeof(fd_mask));
2031 return SSH_ERR_ALLOC_FAIL;
2032 ssh_packet_write_poll(ssh);
2033 while (ssh_packet_have_data_to_write(ssh)) {
2034 memset(setp, 0, howmany(state->connection_out + 1,
2035 NFDBITS) * sizeof(fd_mask));
2036 FD_SET(state->connection_out, setp);
2038 if (state->packet_timeout_ms > 0) {
2039 ms_remain = state->packet_timeout_ms;
2040 timeoutp = &timeout;
2043 if (state->packet_timeout_ms != -1) {
2044 ms_to_timeval(&timeout, ms_remain);
2045 gettimeofday(&start, NULL);
2047 if ((ret = select(state->connection_out + 1,
2048 NULL, setp, NULL, timeoutp)) >= 0)
2050 if (errno != EAGAIN && errno != EINTR &&
2051 errno != EWOULDBLOCK)
2053 if (state->packet_timeout_ms == -1)
2055 ms_subtract_diff(&start, &ms_remain);
2056 if (ms_remain <= 0) {
2063 return SSH_ERR_CONN_TIMEOUT;
2065 if ((r = ssh_packet_write_poll(ssh)) != 0) {
2074 /* Returns true if there is buffered data to write to the connection. */
2077 ssh_packet_have_data_to_write(struct ssh *ssh)
2079 return sshbuf_len(ssh->state->output) != 0;
2082 /* Returns true if there is not too much data to write to the connection. */
2085 ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
2087 if (ssh->state->interactive_mode)
2088 return sshbuf_len(ssh->state->output) < 16384;
2090 return sshbuf_len(ssh->state->output) < 128 * 1024;
2094 ssh_packet_set_tos(struct ssh *ssh, int tos)
2096 #ifndef IP_TOS_IS_BROKEN
2097 if (!ssh_packet_connection_is_on_socket(ssh))
2099 switch (ssh_packet_connection_af(ssh)) {
2102 debug3("%s: set IP_TOS 0x%02x", __func__, tos);
2103 if (setsockopt(ssh->state->connection_in,
2104 IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2105 error("setsockopt IP_TOS %d: %.100s:",
2106 tos, strerror(errno));
2108 # endif /* IP_TOS */
2111 debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
2112 if (setsockopt(ssh->state->connection_in,
2113 IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2114 error("setsockopt IPV6_TCLASS %d: %.100s:",
2115 tos, strerror(errno));
2117 # endif /* IPV6_TCLASS */
2119 #endif /* IP_TOS_IS_BROKEN */
2122 /* Informs that the current session is interactive. Sets IP flags for that. */
2125 ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
2127 struct session_state *state = ssh->state;
2129 if (state->set_interactive_called)
2131 state->set_interactive_called = 1;
2133 /* Record that we are in interactive mode. */
2134 state->interactive_mode = interactive;
2136 /* Only set socket options if using a socket. */
2137 if (!ssh_packet_connection_is_on_socket(ssh))
2139 set_nodelay(state->connection_in);
2140 ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2144 /* Returns true if the current connection is interactive. */
2147 ssh_packet_is_interactive(struct ssh *ssh)
2149 return ssh->state->interactive_mode;
2153 ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
2155 struct session_state *state = ssh->state;
2157 if (state->set_maxsize_called) {
2158 logit("packet_set_maxsize: called twice: old %d new %d",
2159 state->max_packet_size, s);
2162 if (s < 4 * 1024 || s > 1024 * 1024) {
2163 logit("packet_set_maxsize: bad size %d", s);
2166 state->set_maxsize_called = 1;
2167 debug("packet_set_maxsize: setting to %d", s);
2168 state->max_packet_size = s;
2173 ssh_packet_inc_alive_timeouts(struct ssh *ssh)
2175 return ++ssh->state->keep_alive_timeouts;
2179 ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
2181 ssh->state->keep_alive_timeouts = ka;
2185 ssh_packet_get_maxsize(struct ssh *ssh)
2187 return ssh->state->max_packet_size;
2191 * 9.2. Ignored Data Message
2193 * byte SSH_MSG_IGNORE
2196 * All implementations MUST understand (and ignore) this message at any
2197 * time (after receiving the protocol version). No implementation is
2198 * required to send them. This message can be used as an additional
2199 * protection measure against advanced traffic analysis techniques.
2202 ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
2207 if ((r = sshpkt_start(ssh, compat20 ?
2208 SSH2_MSG_IGNORE : SSH_MSG_IGNORE)) != 0 ||
2209 (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2210 fatal("%s: %s", __func__, ssh_err(r));
2211 for (i = 0; i < nbytes; i++) {
2214 if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2215 fatal("%s: %s", __func__, ssh_err(r));
2220 #define MAX_PACKETS (1U<<31)
2222 ssh_packet_need_rekeying(struct ssh *ssh)
2224 struct session_state *state = ssh->state;
2226 if (ssh->compat & SSH_BUG_NOREKEY)
2229 (state->p_send.packets > MAX_PACKETS) ||
2230 (state->p_read.packets > MAX_PACKETS) ||
2231 (state->max_blocks_out &&
2232 (state->p_send.blocks > state->max_blocks_out)) ||
2233 (state->max_blocks_in &&
2234 (state->p_read.blocks > state->max_blocks_in)) ||
2235 (state->rekey_interval != 0 && state->rekey_time +
2236 state->rekey_interval <= monotime());
2240 ssh_packet_set_rekey_limits(struct ssh *ssh, u_int32_t bytes, time_t seconds)
2242 debug3("rekey after %lld bytes, %d seconds", (long long)bytes,
2244 ssh->state->rekey_limit = bytes;
2245 ssh->state->rekey_interval = seconds;
2249 ssh_packet_get_rekey_timeout(struct ssh *ssh)
2253 seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
2255 return (seconds <= 0 ? 1 : seconds);
2259 ssh_packet_set_server(struct ssh *ssh)
2261 ssh->state->server_side = 1;
2265 ssh_packet_set_authenticated(struct ssh *ssh)
2267 ssh->state->after_authentication = 1;
2271 ssh_packet_get_input(struct ssh *ssh)
2273 return (void *)ssh->state->input;
2277 ssh_packet_get_output(struct ssh *ssh)
2279 return (void *)ssh->state->output;
2282 /* XXX TODO update roaming to new API (does not work anyway) */
2284 * Save the state for the real connection, and use a separate state when
2285 * resuming a suspended connection.
2288 ssh_packet_backup_state(struct ssh *ssh,
2289 struct ssh *backup_state)
2293 close(ssh->state->connection_in);
2294 ssh->state->connection_in = -1;
2295 close(ssh->state->connection_out);
2296 ssh->state->connection_out = -1;
2300 tmp = ssh_alloc_session_state();
2305 /* XXX FIXME FIXME FIXME */
2307 * Swap in the old state when resuming a connecion.
2310 ssh_packet_restore_state(struct ssh *ssh,
2311 struct ssh *backup_state)
2320 ssh->state->connection_in = backup_state->state->connection_in;
2321 backup_state->state->connection_in = -1;
2322 ssh->state->connection_out = backup_state->state->connection_out;
2323 backup_state->state->connection_out = -1;
2324 len = sshbuf_len(backup_state->state->input);
2326 if ((r = sshbuf_putb(ssh->state->input,
2327 backup_state->state->input)) != 0)
2328 fatal("%s: %s", __func__, ssh_err(r));
2329 sshbuf_reset(backup_state->state->input);
2330 add_recv_bytes(len);
2334 /* Reset after_authentication and reset compression in post-auth privsep */
2336 ssh_packet_set_postauth(struct ssh *ssh)
2338 struct sshcomp *comp;
2341 debug("%s: called", __func__);
2342 /* This was set in net child, but is not visible in user child */
2343 ssh->state->after_authentication = 1;
2344 ssh->state->rekeying = 0;
2345 for (mode = 0; mode < MODE_MAX; mode++) {
2346 if (ssh->state->newkeys[mode] == NULL)
2348 comp = &ssh->state->newkeys[mode]->comp;
2349 if (comp && comp->enabled &&
2350 (r = ssh_packet_init_compression(ssh)) != 0)
2356 /* Packet state (de-)serialization for privsep */
2358 /* turn kex into a blob for packet state serialization */
2360 kex_to_blob(struct sshbuf *m, struct kex *kex)
2364 if ((r = sshbuf_put_string(m, kex->session_id,
2365 kex->session_id_len)) != 0 ||
2366 (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2367 (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2368 (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2369 (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2370 (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2371 (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2372 (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2373 (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2378 /* turn key exchange results into a blob for packet state serialization */
2380 newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2383 struct sshcipher_ctx *cc;
2384 struct sshcomp *comp;
2387 struct newkeys *newkey;
2390 if ((newkey = ssh->state->newkeys[mode]) == NULL)
2391 return SSH_ERR_INTERNAL_ERROR;
2394 comp = &newkey->comp;
2395 cc = (mode == MODE_OUT) ? &ssh->state->send_context :
2396 &ssh->state->receive_context;
2397 if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2399 if ((b = sshbuf_new()) == NULL)
2400 return SSH_ERR_ALLOC_FAIL;
2401 /* The cipher struct is constant and shared, you export pointer */
2402 if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2403 (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2404 (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2405 (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2406 (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2407 (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2409 if (cipher_authlen(enc->cipher) == 0) {
2410 if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2411 (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2412 (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2415 if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2416 (r = sshbuf_put_u32(b, comp->enabled)) != 0 ||
2417 (r = sshbuf_put_cstring(b, comp->name)) != 0)
2419 r = sshbuf_put_stringb(m, b);
2426 /* serialize packet state into a blob */
2428 ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2430 struct session_state *state = ssh->state;
2436 ssh1cipher = cipher_get_number(state->receive_context.cipher);
2437 slen = cipher_get_keyiv_len(&state->send_context);
2438 rlen = cipher_get_keyiv_len(&state->receive_context);
2439 if ((r = sshbuf_put_u32(m, state->remote_protocol_flags)) != 0 ||
2440 (r = sshbuf_put_u32(m, ssh1cipher)) != 0 ||
2441 (r = sshbuf_put_string(m, state->ssh1_key, state->ssh1_keylen)) != 0 ||
2442 (r = sshbuf_put_u32(m, slen)) != 0 ||
2443 (r = sshbuf_reserve(m, slen, &p)) != 0 ||
2444 (r = cipher_get_keyiv(&state->send_context, p, slen)) != 0 ||
2445 (r = sshbuf_put_u32(m, rlen)) != 0 ||
2446 (r = sshbuf_reserve(m, rlen, &p)) != 0 ||
2447 (r = cipher_get_keyiv(&state->receive_context, p, rlen)) != 0)
2450 if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2451 (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2452 (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2453 (r = sshbuf_put_u32(m, state->rekey_limit)) != 0 ||
2454 (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2455 (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2456 (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2457 (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2458 (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2459 (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2460 (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2461 (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2462 (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0)
2466 slen = cipher_get_keycontext(&state->send_context, NULL);
2467 rlen = cipher_get_keycontext(&state->receive_context, NULL);
2468 if ((r = sshbuf_put_u32(m, slen)) != 0 ||
2469 (r = sshbuf_reserve(m, slen, &p)) != 0)
2471 if (cipher_get_keycontext(&state->send_context, p) != (int)slen)
2472 return SSH_ERR_INTERNAL_ERROR;
2473 if ((r = sshbuf_put_u32(m, rlen)) != 0 ||
2474 (r = sshbuf_reserve(m, rlen, &p)) != 0)
2476 if (cipher_get_keycontext(&state->receive_context, p) != (int)rlen)
2477 return SSH_ERR_INTERNAL_ERROR;
2479 if ((r = ssh_packet_get_compress_state(m, ssh)) != 0 ||
2480 (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2481 (r = sshbuf_put_stringb(m, state->output)) != 0)
2485 if ((r = sshbuf_put_u64(m, get_sent_bytes())) != 0 ||
2486 (r = sshbuf_put_u64(m, get_recv_bytes())) != 0)
2492 /* restore key exchange results from blob for packet state de-serialization */
2494 newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2496 struct sshbuf *b = NULL;
2497 struct sshcomp *comp;
2500 struct newkeys *newkey = NULL;
2501 size_t keylen, ivlen, maclen;
2504 if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2505 r = SSH_ERR_ALLOC_FAIL;
2508 if ((r = sshbuf_froms(m, &b)) != 0)
2511 sshbuf_dump(b, stderr);
2515 comp = &newkey->comp;
2517 if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2518 (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2519 (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2520 (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2521 (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2522 (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2524 if (cipher_authlen(enc->cipher) == 0) {
2525 if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2527 if ((r = mac_setup(mac, mac->name)) != 0)
2529 if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2530 (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2532 if (maclen > mac->key_len) {
2533 r = SSH_ERR_INVALID_FORMAT;
2536 mac->key_len = maclen;
2538 if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2539 (r = sshbuf_get_u32(b, (u_int *)&comp->enabled)) != 0 ||
2540 (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2542 if (enc->name == NULL ||
2543 cipher_by_name(enc->name) != enc->cipher) {
2544 r = SSH_ERR_INVALID_FORMAT;
2547 if (sshbuf_len(b) != 0) {
2548 r = SSH_ERR_INVALID_FORMAT;
2551 enc->key_len = keylen;
2552 enc->iv_len = ivlen;
2553 ssh->kex->newkeys[mode] = newkey;
2564 /* restore kex from blob for packet state de-serialization */
2566 kex_from_blob(struct sshbuf *m, struct kex **kexp)
2571 if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2572 (kex->my = sshbuf_new()) == NULL ||
2573 (kex->peer = sshbuf_new()) == NULL) {
2574 r = SSH_ERR_ALLOC_FAIL;
2577 if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2578 (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2579 (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2580 (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2581 (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2582 (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2583 (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2584 (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2585 (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2591 if (r != 0 || kexp == NULL) {
2593 if (kex->my != NULL)
2594 sshbuf_free(kex->my);
2595 if (kex->peer != NULL)
2596 sshbuf_free(kex->peer);
2608 * Restore packet state from content of blob 'm' (de-serialization).
2609 * Note that 'm' will be partially consumed on parsing or any other errors.
2612 ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2614 struct session_state *state = ssh->state;
2615 const u_char *ssh1key, *ivin, *ivout, *keyin, *keyout, *input, *output;
2616 size_t ssh1keylen, rlen, slen, ilen, olen;
2618 u_int ssh1cipher = 0;
2619 u_int64_t sent_bytes = 0, recv_bytes = 0;
2622 if ((r = sshbuf_get_u32(m, &state->remote_protocol_flags)) != 0 ||
2623 (r = sshbuf_get_u32(m, &ssh1cipher)) != 0 ||
2624 (r = sshbuf_get_string_direct(m, &ssh1key, &ssh1keylen)) != 0 ||
2625 (r = sshbuf_get_string_direct(m, &ivout, &slen)) != 0 ||
2626 (r = sshbuf_get_string_direct(m, &ivin, &rlen)) != 0)
2628 if (ssh1cipher > INT_MAX)
2629 return SSH_ERR_KEY_UNKNOWN_CIPHER;
2630 ssh_packet_set_encryption_key(ssh, ssh1key, ssh1keylen,
2632 if (cipher_get_keyiv_len(&state->send_context) != (int)slen ||
2633 cipher_get_keyiv_len(&state->receive_context) != (int)rlen)
2634 return SSH_ERR_INVALID_FORMAT;
2635 if ((r = cipher_set_keyiv(&state->send_context, ivout)) != 0 ||
2636 (r = cipher_set_keyiv(&state->receive_context, ivin)) != 0)
2639 if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2640 (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2641 (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2642 (r = sshbuf_get_u32(m, &state->rekey_limit)) != 0 ||
2643 (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2644 (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2645 (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2646 (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2647 (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2648 (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2649 (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2650 (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2651 (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2654 * We set the time here so that in post-auth privsep slave we
2655 * count from the completion of the authentication.
2657 state->rekey_time = monotime();
2658 /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2659 if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2660 (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2663 if ((r = sshbuf_get_string_direct(m, &keyout, &slen)) != 0 ||
2664 (r = sshbuf_get_string_direct(m, &keyin, &rlen)) != 0)
2666 if (cipher_get_keycontext(&state->send_context, NULL) != (int)slen ||
2667 cipher_get_keycontext(&state->receive_context, NULL) != (int)rlen)
2668 return SSH_ERR_INVALID_FORMAT;
2669 cipher_set_keycontext(&state->send_context, keyout);
2670 cipher_set_keycontext(&state->receive_context, keyin);
2672 if ((r = ssh_packet_set_compress_state(ssh, m)) != 0 ||
2673 (r = ssh_packet_set_postauth(ssh)) != 0)
2676 sshbuf_reset(state->input);
2677 sshbuf_reset(state->output);
2678 if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2679 (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2680 (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2681 (r = sshbuf_put(state->output, output, olen)) != 0)
2685 if ((r = sshbuf_get_u64(m, &sent_bytes)) != 0 ||
2686 (r = sshbuf_get_u64(m, &recv_bytes)) != 0)
2688 roam_set_bytes(sent_bytes, recv_bytes);
2691 return SSH_ERR_INVALID_FORMAT;
2692 debug3("%s: done", __func__);
2698 /* put data to the outgoing packet */
2701 sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2703 return sshbuf_put(ssh->state->outgoing_packet, v, len);
2707 sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2709 return sshbuf_putb(ssh->state->outgoing_packet, b);
2713 sshpkt_put_u8(struct ssh *ssh, u_char val)
2715 return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2719 sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2721 return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2725 sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2727 return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2731 sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2733 return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2737 sshpkt_put_cstring(struct ssh *ssh, const void *v)
2739 return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2743 sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2745 return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2749 #ifdef OPENSSL_HAS_ECC
2751 sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2753 return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2755 #endif /* OPENSSL_HAS_ECC */
2759 sshpkt_put_bignum1(struct ssh *ssh, const BIGNUM *v)
2761 return sshbuf_put_bignum1(ssh->state->outgoing_packet, v);
2763 #endif /* WITH_SSH1 */
2766 sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2768 return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2770 #endif /* WITH_OPENSSL */
2772 /* fetch data from the incoming packet */
2775 sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2777 return sshbuf_get(ssh->state->incoming_packet, valp, len);
2781 sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2783 return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2787 sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2789 return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2793 sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2795 return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2799 sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2801 return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2805 sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2807 return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2811 sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2813 return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2817 #ifdef OPENSSL_HAS_ECC
2819 sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2821 return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2823 #endif /* OPENSSL_HAS_ECC */
2827 sshpkt_get_bignum1(struct ssh *ssh, BIGNUM *v)
2829 return sshbuf_get_bignum1(ssh->state->incoming_packet, v);
2831 #endif /* WITH_SSH1 */
2834 sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2836 return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2838 #endif /* WITH_OPENSSL */
2841 sshpkt_get_end(struct ssh *ssh)
2843 if (sshbuf_len(ssh->state->incoming_packet) > 0)
2844 return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2849 sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2852 *lenp = sshbuf_len(ssh->state->incoming_packet);
2853 return sshbuf_ptr(ssh->state->incoming_packet);
2856 /* start a new packet */
2859 sshpkt_start(struct ssh *ssh, u_char type)
2864 DBG(debug("packet_start[%d]", type));
2865 len = compat20 ? 6 : 9;
2866 memset(buf, 0, len - 1);
2867 buf[len - 1] = type;
2868 sshbuf_reset(ssh->state->outgoing_packet);
2869 return sshbuf_put(ssh->state->outgoing_packet, buf, len);
2875 sshpkt_send(struct ssh *ssh)
2878 return ssh_packet_send2(ssh);
2880 return ssh_packet_send1(ssh);
2884 sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2890 va_start(args, fmt);
2891 vsnprintf(buf, sizeof(buf), fmt, args);
2895 if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2896 (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2897 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2898 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2899 (r = sshpkt_send(ssh)) != 0)
2902 if ((r = sshpkt_start(ssh, SSH_MSG_DISCONNECT)) != 0 ||
2903 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2904 (r = sshpkt_send(ssh)) != 0)
2910 /* roundup current message to pad bytes */
2912 sshpkt_add_padding(struct ssh *ssh, u_char pad)
2914 ssh->state->extra_pad = pad;