1 /* $OpenBSD: packet.c,v 1.208 2015/02/13 18:57:00 markus 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));
295 state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
296 deattack_init(&state->deattack);
298 * Cache the IP address of the remote connection for use in error
299 * messages that might be generated after the connection has closed.
301 (void)ssh_remote_ipaddr(ssh);
306 ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
308 struct session_state *state = ssh->state;
310 if (timeout <= 0 || count <= 0) {
311 state->packet_timeout_ms = -1;
314 if ((INT_MAX / 1000) / count < timeout)
315 state->packet_timeout_ms = INT_MAX;
317 state->packet_timeout_ms = timeout * count * 1000;
321 ssh_packet_stop_discard(struct ssh *ssh)
323 struct session_state *state = ssh->state;
326 if (state->packet_discard_mac) {
329 memset(buf, 'a', sizeof(buf));
330 while (sshbuf_len(state->incoming_packet) <
332 if ((r = sshbuf_put(state->incoming_packet, buf,
335 (void) mac_compute(state->packet_discard_mac,
337 sshbuf_ptr(state->incoming_packet), PACKET_MAX_SIZE,
340 logit("Finished discarding for %.200s", ssh_remote_ipaddr(ssh));
341 return SSH_ERR_MAC_INVALID;
345 ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
346 struct sshmac *mac, u_int packet_length, u_int discard)
348 struct session_state *state = ssh->state;
351 if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
352 if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
354 return SSH_ERR_MAC_INVALID;
356 if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled)
357 state->packet_discard_mac = mac;
358 if (sshbuf_len(state->input) >= discard &&
359 (r = ssh_packet_stop_discard(ssh)) != 0)
361 state->packet_discard = discard - sshbuf_len(state->input);
365 /* Returns 1 if remote host is connected via socket, 0 if not. */
368 ssh_packet_connection_is_on_socket(struct ssh *ssh)
370 struct session_state *state = ssh->state;
371 struct sockaddr_storage from, to;
372 socklen_t fromlen, tolen;
374 /* filedescriptors in and out are the same, so it's a socket */
375 if (state->connection_in == state->connection_out)
377 fromlen = sizeof(from);
378 memset(&from, 0, sizeof(from));
379 if (getpeername(state->connection_in, (struct sockaddr *)&from,
383 memset(&to, 0, sizeof(to));
384 if (getpeername(state->connection_out, (struct sockaddr *)&to,
387 if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
389 if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
395 ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
398 *ibytes = ssh->state->p_read.bytes;
400 *obytes = ssh->state->p_send.bytes;
404 ssh_packet_connection_af(struct ssh *ssh)
406 struct sockaddr_storage to;
407 socklen_t tolen = sizeof(to);
409 memset(&to, 0, sizeof(to));
410 if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
414 if (to.ss_family == AF_INET6 &&
415 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr))
421 /* Sets the connection into non-blocking mode. */
424 ssh_packet_set_nonblocking(struct ssh *ssh)
426 /* Set the socket into non-blocking mode. */
427 set_nonblock(ssh->state->connection_in);
429 if (ssh->state->connection_out != ssh->state->connection_in)
430 set_nonblock(ssh->state->connection_out);
433 /* Returns the socket used for reading. */
436 ssh_packet_get_connection_in(struct ssh *ssh)
438 return ssh->state->connection_in;
441 /* Returns the descriptor used for writing. */
444 ssh_packet_get_connection_out(struct ssh *ssh)
446 return ssh->state->connection_out;
450 * Returns the IP-address of the remote host as a string. The returned
451 * string must not be freed.
455 ssh_remote_ipaddr(struct ssh *ssh)
457 /* Check whether we have cached the ipaddr. */
458 if (ssh->remote_ipaddr == NULL)
459 ssh->remote_ipaddr = ssh_packet_connection_is_on_socket(ssh) ?
460 get_peer_ipaddr(ssh->state->connection_in) :
462 if (ssh->remote_ipaddr == NULL)
464 return ssh->remote_ipaddr;
467 /* Closes the connection and clears and frees internal data structures. */
470 ssh_packet_close(struct ssh *ssh)
472 struct session_state *state = ssh->state;
476 if (!state->initialized)
478 state->initialized = 0;
479 if (state->connection_in == state->connection_out) {
480 shutdown(state->connection_out, SHUT_RDWR);
481 close(state->connection_out);
483 close(state->connection_in);
484 close(state->connection_out);
486 sshbuf_free(state->input);
487 sshbuf_free(state->output);
488 sshbuf_free(state->outgoing_packet);
489 sshbuf_free(state->incoming_packet);
490 for (mode = 0; mode < MODE_MAX; mode++)
491 kex_free_newkeys(state->newkeys[mode]);
492 if (state->compression_buffer) {
493 sshbuf_free(state->compression_buffer);
494 if (state->compression_out_started) {
495 z_streamp stream = &state->compression_out_stream;
496 debug("compress outgoing: "
497 "raw data %llu, compressed %llu, factor %.2f",
498 (unsigned long long)stream->total_in,
499 (unsigned long long)stream->total_out,
500 stream->total_in == 0 ? 0.0 :
501 (double) stream->total_out / stream->total_in);
502 if (state->compression_out_failures == 0)
505 if (state->compression_in_started) {
506 z_streamp stream = &state->compression_out_stream;
507 debug("compress incoming: "
508 "raw data %llu, compressed %llu, factor %.2f",
509 (unsigned long long)stream->total_out,
510 (unsigned long long)stream->total_in,
511 stream->total_out == 0 ? 0.0 :
512 (double) stream->total_in / stream->total_out);
513 if (state->compression_in_failures == 0)
517 if ((r = cipher_cleanup(&state->send_context)) != 0)
518 error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
519 if ((r = cipher_cleanup(&state->receive_context)) != 0)
520 error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
521 if (ssh->remote_ipaddr) {
522 free(ssh->remote_ipaddr);
523 ssh->remote_ipaddr = NULL;
529 /* Sets remote side protocol flags. */
532 ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
534 ssh->state->remote_protocol_flags = protocol_flags;
537 /* Returns the remote protocol flags set earlier by the above function. */
540 ssh_packet_get_protocol_flags(struct ssh *ssh)
542 return ssh->state->remote_protocol_flags;
546 * Starts packet compression from the next packet on in both directions.
547 * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
551 ssh_packet_init_compression(struct ssh *ssh)
553 if (!ssh->state->compression_buffer &&
554 ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
555 return SSH_ERR_ALLOC_FAIL;
560 start_compression_out(struct ssh *ssh, int level)
562 if (level < 1 || level > 9)
563 return SSH_ERR_INVALID_ARGUMENT;
564 debug("Enabling compression at level %d.", level);
565 if (ssh->state->compression_out_started == 1)
566 deflateEnd(&ssh->state->compression_out_stream);
567 switch (deflateInit(&ssh->state->compression_out_stream, level)) {
569 ssh->state->compression_out_started = 1;
572 return SSH_ERR_ALLOC_FAIL;
574 return SSH_ERR_INTERNAL_ERROR;
580 start_compression_in(struct ssh *ssh)
582 if (ssh->state->compression_in_started == 1)
583 inflateEnd(&ssh->state->compression_in_stream);
584 switch (inflateInit(&ssh->state->compression_in_stream)) {
586 ssh->state->compression_in_started = 1;
589 return SSH_ERR_ALLOC_FAIL;
591 return SSH_ERR_INTERNAL_ERROR;
597 ssh_packet_start_compression(struct ssh *ssh, int level)
601 if (ssh->state->packet_compression && !compat20)
602 return SSH_ERR_INTERNAL_ERROR;
603 ssh->state->packet_compression = 1;
604 if ((r = ssh_packet_init_compression(ssh)) != 0 ||
605 (r = start_compression_in(ssh)) != 0 ||
606 (r = start_compression_out(ssh, level)) != 0)
611 /* XXX remove need for separate compression buffer */
613 compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
618 if (ssh->state->compression_out_started != 1)
619 return SSH_ERR_INTERNAL_ERROR;
621 /* This case is not handled below. */
622 if (sshbuf_len(in) == 0)
625 /* Input is the contents of the input buffer. */
626 if ((ssh->state->compression_out_stream.next_in =
627 sshbuf_mutable_ptr(in)) == NULL)
628 return SSH_ERR_INTERNAL_ERROR;
629 ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
631 /* Loop compressing until deflate() returns with avail_out != 0. */
633 /* Set up fixed-size output buffer. */
634 ssh->state->compression_out_stream.next_out = buf;
635 ssh->state->compression_out_stream.avail_out = sizeof(buf);
637 /* Compress as much data into the buffer as possible. */
638 status = deflate(&ssh->state->compression_out_stream,
642 return SSH_ERR_ALLOC_FAIL;
644 /* Append compressed data to output_buffer. */
645 if ((r = sshbuf_put(out, buf, sizeof(buf) -
646 ssh->state->compression_out_stream.avail_out)) != 0)
651 ssh->state->compression_out_failures++;
652 return SSH_ERR_INVALID_FORMAT;
654 } while (ssh->state->compression_out_stream.avail_out == 0);
659 uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
664 if (ssh->state->compression_in_started != 1)
665 return SSH_ERR_INTERNAL_ERROR;
667 if ((ssh->state->compression_in_stream.next_in =
668 sshbuf_mutable_ptr(in)) == NULL)
669 return SSH_ERR_INTERNAL_ERROR;
670 ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
673 /* Set up fixed-size output buffer. */
674 ssh->state->compression_in_stream.next_out = buf;
675 ssh->state->compression_in_stream.avail_out = sizeof(buf);
677 status = inflate(&ssh->state->compression_in_stream,
681 if ((r = sshbuf_put(out, buf, sizeof(buf) -
682 ssh->state->compression_in_stream.avail_out)) != 0)
687 * Comments in zlib.h say that we should keep calling
688 * inflate() until we get an error. This appears to
689 * be the error that we get.
693 return SSH_ERR_INVALID_FORMAT;
695 return SSH_ERR_ALLOC_FAIL;
698 ssh->state->compression_in_failures++;
699 return SSH_ERR_INTERNAL_ERROR;
705 /* Serialise compression state into a blob for privsep */
707 ssh_packet_get_compress_state(struct sshbuf *m, struct ssh *ssh)
709 struct session_state *state = ssh->state;
713 if ((b = sshbuf_new()) == NULL)
714 return SSH_ERR_ALLOC_FAIL;
715 if (state->compression_in_started) {
716 if ((r = sshbuf_put_string(b, &state->compression_in_stream,
717 sizeof(state->compression_in_stream))) != 0)
719 } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
721 if (state->compression_out_started) {
722 if ((r = sshbuf_put_string(b, &state->compression_out_stream,
723 sizeof(state->compression_out_stream))) != 0)
725 } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
727 r = sshbuf_put_stringb(m, b);
733 /* Deserialise compression state from a blob for privsep */
735 ssh_packet_set_compress_state(struct ssh *ssh, struct sshbuf *m)
737 struct session_state *state = ssh->state;
738 struct sshbuf *b = NULL;
740 const u_char *inblob, *outblob;
743 if ((r = sshbuf_froms(m, &b)) != 0)
745 if ((r = sshbuf_get_string_direct(b, &inblob, &inl)) != 0 ||
746 (r = sshbuf_get_string_direct(b, &outblob, &outl)) != 0)
749 state->compression_in_started = 0;
750 else if (inl != sizeof(state->compression_in_stream)) {
751 r = SSH_ERR_INTERNAL_ERROR;
754 state->compression_in_started = 1;
755 memcpy(&state->compression_in_stream, inblob, inl);
758 state->compression_out_started = 0;
759 else if (outl != sizeof(state->compression_out_stream)) {
760 r = SSH_ERR_INTERNAL_ERROR;
763 state->compression_out_started = 1;
764 memcpy(&state->compression_out_stream, outblob, outl);
773 ssh_packet_set_compress_hooks(struct ssh *ssh, void *ctx,
774 void *(*allocfunc)(void *, u_int, u_int),
775 void (*freefunc)(void *, void *))
777 ssh->state->compression_out_stream.zalloc = (alloc_func)allocfunc;
778 ssh->state->compression_out_stream.zfree = (free_func)freefunc;
779 ssh->state->compression_out_stream.opaque = ctx;
780 ssh->state->compression_in_stream.zalloc = (alloc_func)allocfunc;
781 ssh->state->compression_in_stream.zfree = (free_func)freefunc;
782 ssh->state->compression_in_stream.opaque = ctx;
786 * Causes any further packets to be encrypted using the given key. The same
787 * key is used for both sending and reception. However, both directions are
788 * encrypted independently of each other.
792 ssh_packet_set_encryption_key(struct ssh *ssh, const u_char *key, u_int keylen, int number)
795 struct session_state *state = ssh->state;
796 const struct sshcipher *cipher = cipher_by_number(number);
801 fatal("%s: unknown cipher number %d", __func__, number);
803 fatal("%s: keylen too small: %d", __func__, keylen);
804 if (keylen > SSH_SESSION_KEY_LENGTH)
805 fatal("%s: keylen too big: %d", __func__, keylen);
806 memcpy(state->ssh1_key, key, keylen);
807 state->ssh1_keylen = keylen;
808 if ((r = cipher_init(&state->send_context, cipher, key, keylen,
809 NULL, 0, CIPHER_ENCRYPT)) != 0 ||
810 (r = cipher_init(&state->receive_context, cipher, key, keylen,
811 NULL, 0, CIPHER_DECRYPT) != 0))
812 fatal("%s: cipher_init failed: %s", __func__, ssh_err(r));
813 if (!state->cipher_warning_done &&
814 ((wmsg = cipher_warning_message(&state->send_context)) != NULL ||
815 (wmsg = cipher_warning_message(&state->send_context)) != NULL)) {
816 error("Warning: %s", wmsg);
817 state->cipher_warning_done = 1;
819 #endif /* WITH_SSH1 */
823 * Finalizes and sends the packet. If the encryption key has been set,
824 * encrypts the packet before sending.
828 ssh_packet_send1(struct ssh *ssh)
830 struct session_state *state = ssh->state;
836 * If using packet compression, compress the payload of the outgoing
839 if (state->packet_compression) {
840 sshbuf_reset(state->compression_buffer);
842 if ((r = sshbuf_consume(state->outgoing_packet, 8)) != 0)
845 if ((r = sshbuf_put(state->compression_buffer,
846 "\0\0\0\0\0\0\0\0", 8)) != 0)
848 if ((r = compress_buffer(ssh, state->outgoing_packet,
849 state->compression_buffer)) != 0)
851 sshbuf_reset(state->outgoing_packet);
852 if ((r = sshbuf_putb(state->outgoing_packet,
853 state->compression_buffer)) != 0)
856 /* Compute packet length without padding (add checksum, remove padding). */
857 len = sshbuf_len(state->outgoing_packet) + 4 - 8;
859 /* Insert padding. Initialized to zero in packet_start1() */
860 padding = 8 - len % 8;
861 if (!state->send_context.plaintext) {
862 cp = sshbuf_mutable_ptr(state->outgoing_packet);
864 r = SSH_ERR_INTERNAL_ERROR;
867 arc4random_buf(cp + 8 - padding, padding);
869 if ((r = sshbuf_consume(state->outgoing_packet, 8 - padding)) != 0)
872 /* Add check bytes. */
873 checksum = ssh_crc32(sshbuf_ptr(state->outgoing_packet),
874 sshbuf_len(state->outgoing_packet));
875 POKE_U32(buf, checksum);
876 if ((r = sshbuf_put(state->outgoing_packet, buf, 4)) != 0)
880 fprintf(stderr, "packet_send plain: ");
881 sshbuf_dump(state->outgoing_packet, stderr);
884 /* Append to output. */
886 if ((r = sshbuf_put(state->output, buf, 4)) != 0)
888 if ((r = sshbuf_reserve(state->output,
889 sshbuf_len(state->outgoing_packet), &cp)) != 0)
891 if ((r = cipher_crypt(&state->send_context, 0, cp,
892 sshbuf_ptr(state->outgoing_packet),
893 sshbuf_len(state->outgoing_packet), 0, 0)) != 0)
897 fprintf(stderr, "encrypted: ");
898 sshbuf_dump(state->output, stderr);
900 state->p_send.packets++;
901 state->p_send.bytes += len +
902 sshbuf_len(state->outgoing_packet);
903 sshbuf_reset(state->outgoing_packet);
906 * Note that the packet is now only buffered in output. It won't be
907 * actually sent until ssh_packet_write_wait or ssh_packet_write_poll
916 ssh_set_newkeys(struct ssh *ssh, int mode)
918 struct session_state *state = ssh->state;
921 struct sshcomp *comp;
922 struct sshcipher_ctx *cc;
923 u_int64_t *max_blocks;
927 debug2("set_newkeys: mode %d", mode);
929 if (mode == MODE_OUT) {
930 cc = &state->send_context;
931 crypt_type = CIPHER_ENCRYPT;
932 state->p_send.packets = state->p_send.blocks = 0;
933 max_blocks = &state->max_blocks_out;
935 cc = &state->receive_context;
936 crypt_type = CIPHER_DECRYPT;
937 state->p_read.packets = state->p_read.blocks = 0;
938 max_blocks = &state->max_blocks_in;
940 if (state->newkeys[mode] != NULL) {
941 debug("set_newkeys: rekeying");
942 if ((r = cipher_cleanup(cc)) != 0)
944 enc = &state->newkeys[mode]->enc;
945 mac = &state->newkeys[mode]->mac;
946 comp = &state->newkeys[mode]->comp;
948 explicit_bzero(enc->iv, enc->iv_len);
949 explicit_bzero(enc->key, enc->key_len);
950 explicit_bzero(mac->key, mac->key_len);
957 free(state->newkeys[mode]);
959 /* move newkeys from kex to state */
960 if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
961 return SSH_ERR_INTERNAL_ERROR;
962 ssh->kex->newkeys[mode] = NULL;
963 enc = &state->newkeys[mode]->enc;
964 mac = &state->newkeys[mode]->mac;
965 comp = &state->newkeys[mode]->comp;
966 if (cipher_authlen(enc->cipher) == 0) {
967 if ((r = mac_init(mac)) != 0)
971 DBG(debug("cipher_init_context: %d", mode));
972 if ((r = cipher_init(cc, enc->cipher, enc->key, enc->key_len,
973 enc->iv, enc->iv_len, crypt_type)) != 0)
975 if (!state->cipher_warning_done &&
976 (wmsg = cipher_warning_message(cc)) != NULL) {
977 error("Warning: %s", wmsg);
978 state->cipher_warning_done = 1;
980 /* Deleting the keys does not gain extra security */
981 /* explicit_bzero(enc->iv, enc->block_size);
982 explicit_bzero(enc->key, enc->key_len);
983 explicit_bzero(mac->key, mac->key_len); */
984 if ((comp->type == COMP_ZLIB ||
985 (comp->type == COMP_DELAYED &&
986 state->after_authentication)) && comp->enabled == 0) {
987 if ((r = ssh_packet_init_compression(ssh)) < 0)
989 if (mode == MODE_OUT) {
990 if ((r = start_compression_out(ssh, 6)) != 0)
993 if ((r = start_compression_in(ssh)) != 0)
999 * The 2^(blocksize*2) limit is too expensive for 3DES,
1000 * blowfish, etc, so enforce a 1GB limit for small blocksizes.
1002 if (enc->block_size >= 16)
1003 *max_blocks = (u_int64_t)1 << (enc->block_size*2);
1005 *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1006 if (state->rekey_limit)
1007 *max_blocks = MIN(*max_blocks,
1008 state->rekey_limit / enc->block_size);
1013 * Delayed compression for SSH2 is enabled after authentication:
1014 * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1015 * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
1018 ssh_packet_enable_delayed_compress(struct ssh *ssh)
1020 struct session_state *state = ssh->state;
1021 struct sshcomp *comp = NULL;
1025 * Remember that we are past the authentication step, so rekeying
1026 * with COMP_DELAYED will turn on compression immediately.
1028 state->after_authentication = 1;
1029 for (mode = 0; mode < MODE_MAX; mode++) {
1030 /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1031 if (state->newkeys[mode] == NULL)
1033 comp = &state->newkeys[mode]->comp;
1034 if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1035 if ((r = ssh_packet_init_compression(ssh)) != 0)
1037 if (mode == MODE_OUT) {
1038 if ((r = start_compression_out(ssh, 6)) != 0)
1041 if ((r = start_compression_in(ssh)) != 0)
1051 * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1054 ssh_packet_send2_wrapped(struct ssh *ssh)
1056 struct session_state *state = ssh->state;
1057 u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1058 u_char padlen, pad = 0;
1059 u_int authlen = 0, aadlen = 0;
1061 struct sshenc *enc = NULL;
1062 struct sshmac *mac = NULL;
1063 struct sshcomp *comp = NULL;
1066 if (state->newkeys[MODE_OUT] != NULL) {
1067 enc = &state->newkeys[MODE_OUT]->enc;
1068 mac = &state->newkeys[MODE_OUT]->mac;
1069 comp = &state->newkeys[MODE_OUT]->comp;
1070 /* disable mac for authenticated encryption */
1071 if ((authlen = cipher_authlen(enc->cipher)) != 0)
1074 block_size = enc ? enc->block_size : 8;
1075 aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1077 type = (sshbuf_ptr(state->outgoing_packet))[5];
1080 fprintf(stderr, "plain: ");
1081 sshbuf_dump(state->outgoing_packet, stderr);
1084 if (comp && comp->enabled) {
1085 len = sshbuf_len(state->outgoing_packet);
1086 /* skip header, compress only payload */
1087 if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1089 sshbuf_reset(state->compression_buffer);
1090 if ((r = compress_buffer(ssh, state->outgoing_packet,
1091 state->compression_buffer)) != 0)
1093 sshbuf_reset(state->outgoing_packet);
1094 if ((r = sshbuf_put(state->outgoing_packet,
1095 "\0\0\0\0\0", 5)) != 0 ||
1096 (r = sshbuf_putb(state->outgoing_packet,
1097 state->compression_buffer)) != 0)
1099 DBG(debug("compression: raw %d compressed %zd", len,
1100 sshbuf_len(state->outgoing_packet)));
1103 /* sizeof (packet_len + pad_len + payload) */
1104 len = sshbuf_len(state->outgoing_packet);
1107 * calc size of padding, alloc space, get random data,
1108 * minimum padding is 4 bytes
1110 len -= aadlen; /* packet length is not encrypted for EtM modes */
1111 padlen = block_size - (len % block_size);
1113 padlen += block_size;
1114 if (state->extra_pad) {
1115 /* will wrap if extra_pad+padlen > 255 */
1117 roundup(state->extra_pad, block_size);
1118 pad = state->extra_pad -
1119 ((len + padlen) % state->extra_pad);
1120 DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1121 __func__, pad, len, padlen, state->extra_pad));
1123 state->extra_pad = 0;
1125 if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1127 if (enc && !state->send_context.plaintext) {
1128 /* random padding */
1129 arc4random_buf(cp, padlen);
1132 explicit_bzero(cp, padlen);
1134 /* sizeof (packet_len + pad_len + payload + padding) */
1135 len = sshbuf_len(state->outgoing_packet);
1136 cp = sshbuf_mutable_ptr(state->outgoing_packet);
1138 r = SSH_ERR_INTERNAL_ERROR;
1141 /* packet_length includes payload, padding and padding length field */
1142 POKE_U32(cp, len - 4);
1144 DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1145 len, padlen, aadlen));
1147 /* compute MAC over seqnr and packet(length fields, payload, padding) */
1148 if (mac && mac->enabled && !mac->etm) {
1149 if ((r = mac_compute(mac, state->p_send.seqnr,
1150 sshbuf_ptr(state->outgoing_packet), len,
1151 macbuf, sizeof(macbuf))) != 0)
1153 DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1155 /* encrypt packet and append to output buffer. */
1156 if ((r = sshbuf_reserve(state->output,
1157 sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1159 if ((r = cipher_crypt(&state->send_context, state->p_send.seqnr, cp,
1160 sshbuf_ptr(state->outgoing_packet),
1161 len - aadlen, aadlen, authlen)) != 0)
1163 /* append unencrypted MAC */
1164 if (mac && mac->enabled) {
1166 /* EtM: compute mac over aadlen + cipher text */
1167 if ((r = mac_compute(mac, state->p_send.seqnr,
1168 cp, len, macbuf, sizeof(macbuf))) != 0)
1170 DBG(debug("done calc MAC(EtM) out #%d",
1171 state->p_send.seqnr));
1173 if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1177 fprintf(stderr, "encrypted: ");
1178 sshbuf_dump(state->output, stderr);
1180 /* increment sequence number for outgoing packets */
1181 if (++state->p_send.seqnr == 0)
1182 logit("outgoing seqnr wraps around");
1183 if (++state->p_send.packets == 0)
1184 if (!(ssh->compat & SSH_BUG_NOREKEY))
1185 return SSH_ERR_NEED_REKEY;
1186 state->p_send.blocks += len / block_size;
1187 state->p_send.bytes += len;
1188 sshbuf_reset(state->outgoing_packet);
1190 if (type == SSH2_MSG_NEWKEYS)
1191 r = ssh_set_newkeys(ssh, MODE_OUT);
1192 else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1193 r = ssh_packet_enable_delayed_compress(ssh);
1201 ssh_packet_send2(struct ssh *ssh)
1203 struct session_state *state = ssh->state;
1208 type = sshbuf_ptr(state->outgoing_packet)[5];
1210 /* during rekeying we can only send key exchange messages */
1211 if (state->rekeying) {
1212 if ((type < SSH2_MSG_TRANSPORT_MIN) ||
1213 (type > SSH2_MSG_TRANSPORT_MAX) ||
1214 (type == SSH2_MSG_SERVICE_REQUEST) ||
1215 (type == SSH2_MSG_SERVICE_ACCEPT)) {
1216 debug("enqueue packet: %u", type);
1217 p = calloc(1, sizeof(*p));
1219 return SSH_ERR_ALLOC_FAIL;
1221 p->payload = state->outgoing_packet;
1222 TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1223 state->outgoing_packet = sshbuf_new();
1224 if (state->outgoing_packet == NULL)
1225 return SSH_ERR_ALLOC_FAIL;
1230 /* rekeying starts with sending KEXINIT */
1231 if (type == SSH2_MSG_KEXINIT)
1232 state->rekeying = 1;
1234 if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1237 /* after a NEWKEYS message we can send the complete queue */
1238 if (type == SSH2_MSG_NEWKEYS) {
1239 state->rekeying = 0;
1240 state->rekey_time = monotime();
1241 while ((p = TAILQ_FIRST(&state->outgoing))) {
1243 debug("dequeue packet: %u", type);
1244 sshbuf_free(state->outgoing_packet);
1245 state->outgoing_packet = p->payload;
1246 TAILQ_REMOVE(&state->outgoing, p, next);
1248 if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1256 * Waits until a packet has been received, and returns its type. Note that
1257 * no other data is processed until this returns, so this function should not
1258 * be used during the interactive session.
1262 ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1264 struct session_state *state = ssh->state;
1265 int len, r, ms_remain, cont;
1268 struct timeval timeout, start, *timeoutp = NULL;
1270 DBG(debug("packet_read()"));
1272 setp = (fd_set *)calloc(howmany(state->connection_in + 1,
1273 NFDBITS), sizeof(fd_mask));
1275 return SSH_ERR_ALLOC_FAIL;
1278 * Since we are blocking, ensure that all written packets have
1281 if ((r = ssh_packet_write_wait(ssh)) != 0)
1284 /* Stay in the loop until we have received a complete packet. */
1286 /* Try to read a packet from the buffer. */
1287 r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1291 *typep == SSH_SMSG_SUCCESS
1292 || *typep == SSH_SMSG_FAILURE
1293 || *typep == SSH_CMSG_EOF
1294 || *typep == SSH_CMSG_EXIT_CONFIRMATION))
1295 if ((r = sshpkt_get_end(ssh)) != 0)
1297 /* If we got a packet, return it. */
1298 if (*typep != SSH_MSG_NONE)
1301 * Otherwise, wait for some data to arrive, add it to the
1302 * buffer, and try again.
1304 memset(setp, 0, howmany(state->connection_in + 1,
1305 NFDBITS) * sizeof(fd_mask));
1306 FD_SET(state->connection_in, setp);
1308 if (state->packet_timeout_ms > 0) {
1309 ms_remain = state->packet_timeout_ms;
1310 timeoutp = &timeout;
1312 /* Wait for some data to arrive. */
1314 if (state->packet_timeout_ms != -1) {
1315 ms_to_timeval(&timeout, ms_remain);
1316 gettimeofday(&start, NULL);
1318 if ((r = select(state->connection_in + 1, setp,
1319 NULL, NULL, timeoutp)) >= 0)
1321 if (errno != EAGAIN && errno != EINTR &&
1322 errno != EWOULDBLOCK)
1324 if (state->packet_timeout_ms == -1)
1326 ms_subtract_diff(&start, &ms_remain);
1327 if (ms_remain <= 0) {
1333 return SSH_ERR_CONN_TIMEOUT;
1334 /* Read data from the socket. */
1337 len = roaming_read(state->connection_in, buf,
1338 sizeof(buf), &cont);
1339 } while (len == 0 && cont);
1341 return SSH_ERR_CONN_CLOSED;
1343 return SSH_ERR_SYSTEM_ERROR;
1345 /* Append it to the buffer. */
1346 if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1354 ssh_packet_read(struct ssh *ssh)
1359 if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1360 fatal("%s: %s", __func__, ssh_err(r));
1365 * Waits until a packet has been received, verifies that its type matches
1366 * that given, and gives a fatal error and exits if there is a mismatch.
1370 ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1375 if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1377 if (type != expected_type) {
1378 if ((r = sshpkt_disconnect(ssh,
1379 "Protocol error: expected packet type %d, got %d",
1380 expected_type, type)) != 0)
1382 return SSH_ERR_PROTOCOL_ERROR;
1387 /* Checks if a full packet is available in the data received so far via
1388 * packet_process_incoming. If so, reads the packet; otherwise returns
1389 * SSH_MSG_NONE. This does not wait for data from the connection.
1391 * SSH_MSG_DISCONNECT is handled specially here. Also,
1392 * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1397 ssh_packet_read_poll1(struct ssh *ssh, u_char *typep)
1399 struct session_state *state = ssh->state;
1400 u_int len, padded_len;
1404 u_int checksum, stored_checksum;
1407 *typep = SSH_MSG_NONE;
1409 /* Check if input size is less than minimum packet size. */
1410 if (sshbuf_len(state->input) < 4 + 8)
1412 /* Get length of incoming packet. */
1413 len = PEEK_U32(sshbuf_ptr(state->input));
1414 if (len < 1 + 2 + 2 || len > 256 * 1024) {
1415 if ((r = sshpkt_disconnect(ssh, "Bad packet length %u",
1418 return SSH_ERR_CONN_CORRUPT;
1420 padded_len = (len + 8) & ~7;
1422 /* Check if the packet has been entirely received. */
1423 if (sshbuf_len(state->input) < 4 + padded_len)
1426 /* The entire packet is in buffer. */
1428 /* Consume packet length. */
1429 if ((r = sshbuf_consume(state->input, 4)) != 0)
1433 * Cryptographic attack detector for ssh
1434 * (C)1998 CORE-SDI, Buenos Aires Argentina
1435 * Ariel Futoransky(futo@core-sdi.com)
1437 if (!state->receive_context.plaintext) {
1439 switch (detect_attack(&state->deattack,
1440 sshbuf_ptr(state->input), padded_len)) {
1443 case DEATTACK_DETECTED:
1444 emsg = "crc32 compensation attack detected";
1446 case DEATTACK_DOS_DETECTED:
1447 emsg = "deattack denial of service detected";
1450 emsg = "deattack error";
1455 if ((r = sshpkt_disconnect(ssh, "%s", emsg)) != 0 ||
1456 (r = ssh_packet_write_wait(ssh)) != 0)
1458 return SSH_ERR_CONN_CORRUPT;
1462 /* Decrypt data to incoming_packet. */
1463 sshbuf_reset(state->incoming_packet);
1464 if ((r = sshbuf_reserve(state->incoming_packet, padded_len, &p)) != 0)
1466 if ((r = cipher_crypt(&state->receive_context, 0, p,
1467 sshbuf_ptr(state->input), padded_len, 0, 0)) != 0)
1470 if ((r = sshbuf_consume(state->input, padded_len)) != 0)
1474 fprintf(stderr, "read_poll plain: ");
1475 sshbuf_dump(state->incoming_packet, stderr);
1478 /* Compute packet checksum. */
1479 checksum = ssh_crc32(sshbuf_ptr(state->incoming_packet),
1480 sshbuf_len(state->incoming_packet) - 4);
1483 if ((r = sshbuf_consume(state->incoming_packet, 8 - len % 8)) != 0)
1486 /* Test check bytes. */
1487 if (len != sshbuf_len(state->incoming_packet)) {
1488 error("%s: len %d != sshbuf_len %zd", __func__,
1489 len, sshbuf_len(state->incoming_packet));
1490 if ((r = sshpkt_disconnect(ssh, "invalid packet length")) != 0 ||
1491 (r = ssh_packet_write_wait(ssh)) != 0)
1493 return SSH_ERR_CONN_CORRUPT;
1496 cp = sshbuf_ptr(state->incoming_packet) + len - 4;
1497 stored_checksum = PEEK_U32(cp);
1498 if (checksum != stored_checksum) {
1499 error("Corrupted check bytes on input");
1500 if ((r = sshpkt_disconnect(ssh, "connection corrupted")) != 0 ||
1501 (r = ssh_packet_write_wait(ssh)) != 0)
1503 return SSH_ERR_CONN_CORRUPT;
1505 if ((r = sshbuf_consume_end(state->incoming_packet, 4)) < 0)
1508 if (state->packet_compression) {
1509 sshbuf_reset(state->compression_buffer);
1510 if ((r = uncompress_buffer(ssh, state->incoming_packet,
1511 state->compression_buffer)) != 0)
1513 sshbuf_reset(state->incoming_packet);
1514 if ((r = sshbuf_putb(state->incoming_packet,
1515 state->compression_buffer)) != 0)
1518 state->p_read.packets++;
1519 state->p_read.bytes += padded_len + 4;
1520 if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1522 if (*typep < SSH_MSG_MIN || *typep > SSH_MSG_MAX) {
1523 error("Invalid ssh1 packet type: %d", *typep);
1524 if ((r = sshpkt_disconnect(ssh, "invalid packet type")) != 0 ||
1525 (r = ssh_packet_write_wait(ssh)) != 0)
1527 return SSH_ERR_PROTOCOL_ERROR;
1535 ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1537 struct session_state *state = ssh->state;
1539 u_char *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1540 u_int maclen, aadlen = 0, authlen = 0, block_size;
1541 struct sshenc *enc = NULL;
1542 struct sshmac *mac = NULL;
1543 struct sshcomp *comp = NULL;
1546 *typep = SSH_MSG_NONE;
1548 if (state->packet_discard)
1551 if (state->newkeys[MODE_IN] != NULL) {
1552 enc = &state->newkeys[MODE_IN]->enc;
1553 mac = &state->newkeys[MODE_IN]->mac;
1554 comp = &state->newkeys[MODE_IN]->comp;
1555 /* disable mac for authenticated encryption */
1556 if ((authlen = cipher_authlen(enc->cipher)) != 0)
1559 maclen = mac && mac->enabled ? mac->mac_len : 0;
1560 block_size = enc ? enc->block_size : 8;
1561 aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1563 if (aadlen && state->packlen == 0) {
1564 if (cipher_get_length(&state->receive_context,
1565 &state->packlen, state->p_read.seqnr,
1566 sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1568 if (state->packlen < 1 + 4 ||
1569 state->packlen > PACKET_MAX_SIZE) {
1571 sshbuf_dump(state->input, stderr);
1573 logit("Bad packet length %u.", state->packlen);
1574 if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1577 sshbuf_reset(state->incoming_packet);
1578 } else if (state->packlen == 0) {
1580 * check if input size is less than the cipher block size,
1581 * decrypt first block and extract length of incoming packet
1583 if (sshbuf_len(state->input) < block_size)
1585 sshbuf_reset(state->incoming_packet);
1586 if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1589 if ((r = cipher_crypt(&state->receive_context,
1590 state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1591 block_size, 0, 0)) != 0)
1593 state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1594 if (state->packlen < 1 + 4 ||
1595 state->packlen > PACKET_MAX_SIZE) {
1597 fprintf(stderr, "input: \n");
1598 sshbuf_dump(state->input, stderr);
1599 fprintf(stderr, "incoming_packet: \n");
1600 sshbuf_dump(state->incoming_packet, stderr);
1602 logit("Bad packet length %u.", state->packlen);
1603 return ssh_packet_start_discard(ssh, enc, mac,
1604 state->packlen, PACKET_MAX_SIZE);
1606 if ((r = sshbuf_consume(state->input, block_size)) != 0)
1609 DBG(debug("input: packet len %u", state->packlen+4));
1612 /* only the payload is encrypted */
1613 need = state->packlen;
1616 * the payload size and the payload are encrypted, but we
1617 * have a partial packet of block_size bytes
1619 need = 4 + state->packlen - block_size;
1621 DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1622 " aadlen %d", block_size, need, maclen, authlen, aadlen));
1623 if (need % block_size != 0) {
1624 logit("padding error: need %d block %d mod %d",
1625 need, block_size, need % block_size);
1626 return ssh_packet_start_discard(ssh, enc, mac,
1627 state->packlen, PACKET_MAX_SIZE - block_size);
1630 * check if the entire packet has been received and
1631 * decrypt into incoming_packet:
1632 * 'aadlen' bytes are unencrypted, but authenticated.
1633 * 'need' bytes are encrypted, followed by either
1634 * 'authlen' bytes of authentication tag or
1635 * 'maclen' bytes of message authentication code.
1637 if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1640 fprintf(stderr, "read_poll enc/full: ");
1641 sshbuf_dump(state->input, stderr);
1643 /* EtM: compute mac over encrypted input */
1644 if (mac && mac->enabled && mac->etm) {
1645 if ((r = mac_compute(mac, state->p_read.seqnr,
1646 sshbuf_ptr(state->input), aadlen + need,
1647 macbuf, sizeof(macbuf))) != 0)
1650 if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1653 if ((r = cipher_crypt(&state->receive_context, state->p_read.seqnr, cp,
1654 sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1656 if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1659 * compute MAC over seqnr and packet,
1660 * increment sequence number for incoming packet
1662 if (mac && mac->enabled) {
1664 if ((r = mac_compute(mac, state->p_read.seqnr,
1665 sshbuf_ptr(state->incoming_packet),
1666 sshbuf_len(state->incoming_packet),
1667 macbuf, sizeof(macbuf))) != 0)
1669 if (timingsafe_bcmp(macbuf, sshbuf_ptr(state->input),
1670 mac->mac_len) != 0) {
1671 logit("Corrupted MAC on input.");
1672 if (need > PACKET_MAX_SIZE)
1673 return SSH_ERR_INTERNAL_ERROR;
1674 return ssh_packet_start_discard(ssh, enc, mac,
1675 state->packlen, PACKET_MAX_SIZE - need);
1678 DBG(debug("MAC #%d ok", state->p_read.seqnr));
1679 if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1682 if (seqnr_p != NULL)
1683 *seqnr_p = state->p_read.seqnr;
1684 if (++state->p_read.seqnr == 0)
1685 logit("incoming seqnr wraps around");
1686 if (++state->p_read.packets == 0)
1687 if (!(ssh->compat & SSH_BUG_NOREKEY))
1688 return SSH_ERR_NEED_REKEY;
1689 state->p_read.blocks += (state->packlen + 4) / block_size;
1690 state->p_read.bytes += state->packlen + 4;
1693 padlen = sshbuf_ptr(state->incoming_packet)[4];
1694 DBG(debug("input: padlen %d", padlen));
1696 if ((r = sshpkt_disconnect(ssh,
1697 "Corrupted padlen %d on input.", padlen)) != 0 ||
1698 (r = ssh_packet_write_wait(ssh)) != 0)
1700 return SSH_ERR_CONN_CORRUPT;
1703 /* skip packet size + padlen, discard padding */
1704 if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1705 ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1708 DBG(debug("input: len before de-compress %zd",
1709 sshbuf_len(state->incoming_packet)));
1710 if (comp && comp->enabled) {
1711 sshbuf_reset(state->compression_buffer);
1712 if ((r = uncompress_buffer(ssh, state->incoming_packet,
1713 state->compression_buffer)) != 0)
1715 sshbuf_reset(state->incoming_packet);
1716 if ((r = sshbuf_putb(state->incoming_packet,
1717 state->compression_buffer)) != 0)
1719 DBG(debug("input: len after de-compress %zd",
1720 sshbuf_len(state->incoming_packet)));
1723 * get packet type, implies consume.
1724 * return length of payload (without type field)
1726 if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1728 if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1729 if ((r = sshpkt_disconnect(ssh,
1730 "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1731 (r = ssh_packet_write_wait(ssh)) != 0)
1733 return SSH_ERR_PROTOCOL_ERROR;
1735 if (*typep == SSH2_MSG_NEWKEYS)
1736 r = ssh_set_newkeys(ssh, MODE_IN);
1737 else if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1738 r = ssh_packet_enable_delayed_compress(ssh);
1742 fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1743 sshbuf_dump(state->incoming_packet, stderr);
1745 /* reset for next packet */
1752 ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1754 struct session_state *state = ssh->state;
1755 u_int reason, seqnr;
1762 r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1766 state->keep_alive_timeouts = 0;
1767 DBG(debug("received packet type %d", *typep));
1770 case SSH2_MSG_IGNORE:
1771 debug3("Received SSH2_MSG_IGNORE");
1773 case SSH2_MSG_DEBUG:
1774 if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1775 (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1776 (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1781 debug("Remote: %.900s", msg);
1784 case SSH2_MSG_DISCONNECT:
1785 if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1786 (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1788 /* Ignore normal client exit notifications */
1789 do_log2(ssh->state->server_side &&
1790 reason == SSH2_DISCONNECT_BY_APPLICATION ?
1791 SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1792 "Received disconnect from %s: %u: %.400s",
1793 ssh_remote_ipaddr(ssh), reason, msg);
1795 return SSH_ERR_DISCONNECTED;
1796 case SSH2_MSG_UNIMPLEMENTED:
1797 if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1799 debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1806 r = ssh_packet_read_poll1(ssh, typep);
1809 return SSH_MSG_NONE;
1810 case SSH_MSG_IGNORE:
1813 if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1815 debug("Remote: %.900s", msg);
1818 case SSH_MSG_DISCONNECT:
1819 if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1821 error("Received disconnect from %s: %.400s",
1822 ssh_remote_ipaddr(ssh), msg);
1824 return SSH_ERR_DISCONNECTED;
1826 DBG(debug("received packet type %d", *typep));
1834 * Buffers the given amount of input characters. This is intended to be used
1835 * together with packet_read_poll.
1839 ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1841 struct session_state *state = ssh->state;
1844 if (state->packet_discard) {
1845 state->keep_alive_timeouts = 0; /* ?? */
1846 if (len >= state->packet_discard) {
1847 if ((r = ssh_packet_stop_discard(ssh)) != 0)
1850 state->packet_discard -= len;
1853 if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1860 ssh_packet_remaining(struct ssh *ssh)
1862 return sshbuf_len(ssh->state->incoming_packet);
1866 * Sends a diagnostic message from the server to the client. This message
1867 * can be sent at any time (but not while constructing another message). The
1868 * message is printed immediately, but only if the client is being executed
1869 * in verbose mode. These messages are primarily intended to ease debugging
1870 * authentication problems. The length of the formatted message must not
1871 * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1874 ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1880 if (compat20 && (ssh->compat & SSH_BUG_DEBUG))
1883 va_start(args, fmt);
1884 vsnprintf(buf, sizeof(buf), fmt, args);
1888 if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1889 (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1890 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1891 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1892 (r = sshpkt_send(ssh)) != 0)
1893 fatal("%s: %s", __func__, ssh_err(r));
1895 if ((r = sshpkt_start(ssh, SSH_MSG_DEBUG)) != 0 ||
1896 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1897 (r = sshpkt_send(ssh)) != 0)
1898 fatal("%s: %s", __func__, ssh_err(r));
1900 if ((r = ssh_packet_write_wait(ssh)) != 0)
1901 fatal("%s: %s", __func__, ssh_err(r));
1905 * Pretty-print connection-terminating errors and exit.
1908 sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
1911 case SSH_ERR_CONN_CLOSED:
1912 logit("Connection closed by %.200s", ssh_remote_ipaddr(ssh));
1914 case SSH_ERR_CONN_TIMEOUT:
1915 logit("Connection to %.200s timed out while "
1916 "waiting to write", ssh_remote_ipaddr(ssh));
1919 fatal("%s%sConnection to %.200s: %s",
1920 tag != NULL ? tag : "", tag != NULL ? ": " : "",
1921 ssh_remote_ipaddr(ssh), ssh_err(r));
1926 * Logs the error plus constructs and sends a disconnect packet, closes the
1927 * connection, and exits. This function never returns. The error message
1928 * should not contain a newline. The length of the formatted message must
1929 * not exceed 1024 bytes.
1932 ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1936 static int disconnecting = 0;
1939 if (disconnecting) /* Guard against recursive invocations. */
1940 fatal("packet_disconnect called recursively.");
1944 * Format the message. Note that the caller must make sure the
1945 * message is of limited size.
1947 va_start(args, fmt);
1948 vsnprintf(buf, sizeof(buf), fmt, args);
1951 /* Display the error locally */
1952 logit("Disconnecting: %.100s", buf);
1955 * Send the disconnect message to the other side, and wait
1956 * for it to get sent.
1958 if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1959 sshpkt_fatal(ssh, __func__, r);
1961 if ((r = ssh_packet_write_wait(ssh)) != 0)
1962 sshpkt_fatal(ssh, __func__, r);
1964 /* Close the connection. */
1965 ssh_packet_close(ssh);
1970 * Checks if there is any buffered output, and tries to write some of
1974 ssh_packet_write_poll(struct ssh *ssh)
1976 struct session_state *state = ssh->state;
1977 int len = sshbuf_len(state->output);
1982 len = roaming_write(state->connection_out,
1983 sshbuf_ptr(state->output), len, &cont);
1985 if (errno == EINTR || errno == EAGAIN ||
1986 errno == EWOULDBLOCK)
1988 return SSH_ERR_SYSTEM_ERROR;
1990 if (len == 0 && !cont)
1991 return SSH_ERR_CONN_CLOSED;
1992 if ((r = sshbuf_consume(state->output, len)) != 0)
1999 * Calls packet_write_poll repeatedly until all pending output data has been
2003 ssh_packet_write_wait(struct ssh *ssh)
2006 int ret, r, ms_remain = 0;
2007 struct timeval start, timeout, *timeoutp = NULL;
2008 struct session_state *state = ssh->state;
2010 setp = (fd_set *)calloc(howmany(state->connection_out + 1,
2011 NFDBITS), sizeof(fd_mask));
2013 return SSH_ERR_ALLOC_FAIL;
2014 ssh_packet_write_poll(ssh);
2015 while (ssh_packet_have_data_to_write(ssh)) {
2016 memset(setp, 0, howmany(state->connection_out + 1,
2017 NFDBITS) * sizeof(fd_mask));
2018 FD_SET(state->connection_out, setp);
2020 if (state->packet_timeout_ms > 0) {
2021 ms_remain = state->packet_timeout_ms;
2022 timeoutp = &timeout;
2025 if (state->packet_timeout_ms != -1) {
2026 ms_to_timeval(&timeout, ms_remain);
2027 gettimeofday(&start, NULL);
2029 if ((ret = select(state->connection_out + 1,
2030 NULL, setp, NULL, timeoutp)) >= 0)
2032 if (errno != EAGAIN && errno != EINTR &&
2033 errno != EWOULDBLOCK)
2035 if (state->packet_timeout_ms == -1)
2037 ms_subtract_diff(&start, &ms_remain);
2038 if (ms_remain <= 0) {
2045 return SSH_ERR_CONN_TIMEOUT;
2047 if ((r = ssh_packet_write_poll(ssh)) != 0) {
2056 /* Returns true if there is buffered data to write to the connection. */
2059 ssh_packet_have_data_to_write(struct ssh *ssh)
2061 return sshbuf_len(ssh->state->output) != 0;
2064 /* Returns true if there is not too much data to write to the connection. */
2067 ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
2069 if (ssh->state->interactive_mode)
2070 return sshbuf_len(ssh->state->output) < 16384;
2072 return sshbuf_len(ssh->state->output) < 128 * 1024;
2076 ssh_packet_set_tos(struct ssh *ssh, int tos)
2078 #ifndef IP_TOS_IS_BROKEN
2079 if (!ssh_packet_connection_is_on_socket(ssh))
2081 switch (ssh_packet_connection_af(ssh)) {
2084 debug3("%s: set IP_TOS 0x%02x", __func__, tos);
2085 if (setsockopt(ssh->state->connection_in,
2086 IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2087 error("setsockopt IP_TOS %d: %.100s:",
2088 tos, strerror(errno));
2090 # endif /* IP_TOS */
2093 debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
2094 if (setsockopt(ssh->state->connection_in,
2095 IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2096 error("setsockopt IPV6_TCLASS %d: %.100s:",
2097 tos, strerror(errno));
2099 # endif /* IPV6_TCLASS */
2101 #endif /* IP_TOS_IS_BROKEN */
2104 /* Informs that the current session is interactive. Sets IP flags for that. */
2107 ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
2109 struct session_state *state = ssh->state;
2111 if (state->set_interactive_called)
2113 state->set_interactive_called = 1;
2115 /* Record that we are in interactive mode. */
2116 state->interactive_mode = interactive;
2118 /* Only set socket options if using a socket. */
2119 if (!ssh_packet_connection_is_on_socket(ssh))
2121 set_nodelay(state->connection_in);
2122 ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2126 /* Returns true if the current connection is interactive. */
2129 ssh_packet_is_interactive(struct ssh *ssh)
2131 return ssh->state->interactive_mode;
2135 ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
2137 struct session_state *state = ssh->state;
2139 if (state->set_maxsize_called) {
2140 logit("packet_set_maxsize: called twice: old %d new %d",
2141 state->max_packet_size, s);
2144 if (s < 4 * 1024 || s > 1024 * 1024) {
2145 logit("packet_set_maxsize: bad size %d", s);
2148 state->set_maxsize_called = 1;
2149 debug("packet_set_maxsize: setting to %d", s);
2150 state->max_packet_size = s;
2155 ssh_packet_inc_alive_timeouts(struct ssh *ssh)
2157 return ++ssh->state->keep_alive_timeouts;
2161 ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
2163 ssh->state->keep_alive_timeouts = ka;
2167 ssh_packet_get_maxsize(struct ssh *ssh)
2169 return ssh->state->max_packet_size;
2173 * 9.2. Ignored Data Message
2175 * byte SSH_MSG_IGNORE
2178 * All implementations MUST understand (and ignore) this message at any
2179 * time (after receiving the protocol version). No implementation is
2180 * required to send them. This message can be used as an additional
2181 * protection measure against advanced traffic analysis techniques.
2184 ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
2189 if ((r = sshpkt_start(ssh, compat20 ?
2190 SSH2_MSG_IGNORE : SSH_MSG_IGNORE)) != 0 ||
2191 (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2192 fatal("%s: %s", __func__, ssh_err(r));
2193 for (i = 0; i < nbytes; i++) {
2196 if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2197 fatal("%s: %s", __func__, ssh_err(r));
2202 #define MAX_PACKETS (1U<<31)
2204 ssh_packet_need_rekeying(struct ssh *ssh)
2206 struct session_state *state = ssh->state;
2208 if (ssh->compat & SSH_BUG_NOREKEY)
2211 (state->p_send.packets > MAX_PACKETS) ||
2212 (state->p_read.packets > MAX_PACKETS) ||
2213 (state->max_blocks_out &&
2214 (state->p_send.blocks > state->max_blocks_out)) ||
2215 (state->max_blocks_in &&
2216 (state->p_read.blocks > state->max_blocks_in)) ||
2217 (state->rekey_interval != 0 && state->rekey_time +
2218 state->rekey_interval <= monotime());
2222 ssh_packet_set_rekey_limits(struct ssh *ssh, u_int32_t bytes, time_t seconds)
2224 debug3("rekey after %lld bytes, %d seconds", (long long)bytes,
2226 ssh->state->rekey_limit = bytes;
2227 ssh->state->rekey_interval = seconds;
2231 ssh_packet_get_rekey_timeout(struct ssh *ssh)
2235 seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
2237 return (seconds <= 0 ? 1 : seconds);
2241 ssh_packet_set_server(struct ssh *ssh)
2243 ssh->state->server_side = 1;
2247 ssh_packet_set_authenticated(struct ssh *ssh)
2249 ssh->state->after_authentication = 1;
2253 ssh_packet_get_input(struct ssh *ssh)
2255 return (void *)ssh->state->input;
2259 ssh_packet_get_output(struct ssh *ssh)
2261 return (void *)ssh->state->output;
2264 /* XXX TODO update roaming to new API (does not work anyway) */
2266 * Save the state for the real connection, and use a separate state when
2267 * resuming a suspended connection.
2270 ssh_packet_backup_state(struct ssh *ssh,
2271 struct ssh *backup_state)
2275 close(ssh->state->connection_in);
2276 ssh->state->connection_in = -1;
2277 close(ssh->state->connection_out);
2278 ssh->state->connection_out = -1;
2282 tmp = ssh_alloc_session_state();
2287 /* XXX FIXME FIXME FIXME */
2289 * Swap in the old state when resuming a connecion.
2292 ssh_packet_restore_state(struct ssh *ssh,
2293 struct ssh *backup_state)
2302 ssh->state->connection_in = backup_state->state->connection_in;
2303 backup_state->state->connection_in = -1;
2304 ssh->state->connection_out = backup_state->state->connection_out;
2305 backup_state->state->connection_out = -1;
2306 len = sshbuf_len(backup_state->state->input);
2308 if ((r = sshbuf_putb(ssh->state->input,
2309 backup_state->state->input)) != 0)
2310 fatal("%s: %s", __func__, ssh_err(r));
2311 sshbuf_reset(backup_state->state->input);
2312 add_recv_bytes(len);
2316 /* Reset after_authentication and reset compression in post-auth privsep */
2318 ssh_packet_set_postauth(struct ssh *ssh)
2320 struct sshcomp *comp;
2323 debug("%s: called", __func__);
2324 /* This was set in net child, but is not visible in user child */
2325 ssh->state->after_authentication = 1;
2326 ssh->state->rekeying = 0;
2327 for (mode = 0; mode < MODE_MAX; mode++) {
2328 if (ssh->state->newkeys[mode] == NULL)
2330 comp = &ssh->state->newkeys[mode]->comp;
2331 if (comp && comp->enabled &&
2332 (r = ssh_packet_init_compression(ssh)) != 0)
2338 /* Packet state (de-)serialization for privsep */
2340 /* turn kex into a blob for packet state serialization */
2342 kex_to_blob(struct sshbuf *m, struct kex *kex)
2346 if ((r = sshbuf_put_string(m, kex->session_id,
2347 kex->session_id_len)) != 0 ||
2348 (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2349 (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2350 (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2351 (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2352 (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2353 (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2354 (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2355 (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2360 /* turn key exchange results into a blob for packet state serialization */
2362 newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2365 struct sshcipher_ctx *cc;
2366 struct sshcomp *comp;
2369 struct newkeys *newkey;
2372 if ((newkey = ssh->state->newkeys[mode]) == NULL)
2373 return SSH_ERR_INTERNAL_ERROR;
2376 comp = &newkey->comp;
2377 cc = (mode == MODE_OUT) ? &ssh->state->send_context :
2378 &ssh->state->receive_context;
2379 if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2381 if ((b = sshbuf_new()) == NULL)
2382 return SSH_ERR_ALLOC_FAIL;
2383 /* The cipher struct is constant and shared, you export pointer */
2384 if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2385 (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2386 (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2387 (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2388 (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2389 (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2391 if (cipher_authlen(enc->cipher) == 0) {
2392 if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2393 (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2394 (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2397 if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2398 (r = sshbuf_put_u32(b, comp->enabled)) != 0 ||
2399 (r = sshbuf_put_cstring(b, comp->name)) != 0)
2401 r = sshbuf_put_stringb(m, b);
2408 /* serialize packet state into a blob */
2410 ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2412 struct session_state *state = ssh->state;
2418 ssh1cipher = cipher_get_number(state->receive_context.cipher);
2419 slen = cipher_get_keyiv_len(&state->send_context);
2420 rlen = cipher_get_keyiv_len(&state->receive_context);
2421 if ((r = sshbuf_put_u32(m, state->remote_protocol_flags)) != 0 ||
2422 (r = sshbuf_put_u32(m, ssh1cipher)) != 0 ||
2423 (r = sshbuf_put_string(m, state->ssh1_key, state->ssh1_keylen)) != 0 ||
2424 (r = sshbuf_put_u32(m, slen)) != 0 ||
2425 (r = sshbuf_reserve(m, slen, &p)) != 0 ||
2426 (r = cipher_get_keyiv(&state->send_context, p, slen)) != 0 ||
2427 (r = sshbuf_put_u32(m, rlen)) != 0 ||
2428 (r = sshbuf_reserve(m, rlen, &p)) != 0 ||
2429 (r = cipher_get_keyiv(&state->receive_context, p, rlen)) != 0)
2432 if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2433 (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2434 (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2435 (r = sshbuf_put_u32(m, state->rekey_limit)) != 0 ||
2436 (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2437 (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2438 (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2439 (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2440 (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2441 (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2442 (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2443 (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2444 (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0)
2448 slen = cipher_get_keycontext(&state->send_context, NULL);
2449 rlen = cipher_get_keycontext(&state->receive_context, NULL);
2450 if ((r = sshbuf_put_u32(m, slen)) != 0 ||
2451 (r = sshbuf_reserve(m, slen, &p)) != 0)
2453 if (cipher_get_keycontext(&state->send_context, p) != (int)slen)
2454 return SSH_ERR_INTERNAL_ERROR;
2455 if ((r = sshbuf_put_u32(m, rlen)) != 0 ||
2456 (r = sshbuf_reserve(m, rlen, &p)) != 0)
2458 if (cipher_get_keycontext(&state->receive_context, p) != (int)rlen)
2459 return SSH_ERR_INTERNAL_ERROR;
2461 if ((r = ssh_packet_get_compress_state(m, ssh)) != 0 ||
2462 (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2463 (r = sshbuf_put_stringb(m, state->output)) != 0)
2467 if ((r = sshbuf_put_u64(m, get_sent_bytes())) != 0 ||
2468 (r = sshbuf_put_u64(m, get_recv_bytes())) != 0)
2474 /* restore key exchange results from blob for packet state de-serialization */
2476 newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2478 struct sshbuf *b = NULL;
2479 struct sshcomp *comp;
2482 struct newkeys *newkey = NULL;
2483 size_t keylen, ivlen, maclen;
2486 if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2487 r = SSH_ERR_ALLOC_FAIL;
2490 if ((r = sshbuf_froms(m, &b)) != 0)
2493 sshbuf_dump(b, stderr);
2497 comp = &newkey->comp;
2499 if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2500 (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2501 (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2502 (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2503 (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2504 (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2506 if (cipher_authlen(enc->cipher) == 0) {
2507 if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2509 if ((r = mac_setup(mac, mac->name)) != 0)
2511 if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2512 (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2514 if (maclen > mac->key_len) {
2515 r = SSH_ERR_INVALID_FORMAT;
2518 mac->key_len = maclen;
2520 if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2521 (r = sshbuf_get_u32(b, (u_int *)&comp->enabled)) != 0 ||
2522 (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2524 if (enc->name == NULL ||
2525 cipher_by_name(enc->name) != enc->cipher) {
2526 r = SSH_ERR_INVALID_FORMAT;
2529 if (sshbuf_len(b) != 0) {
2530 r = SSH_ERR_INVALID_FORMAT;
2533 enc->key_len = keylen;
2534 enc->iv_len = ivlen;
2535 ssh->kex->newkeys[mode] = newkey;
2546 /* restore kex from blob for packet state de-serialization */
2548 kex_from_blob(struct sshbuf *m, struct kex **kexp)
2553 if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2554 (kex->my = sshbuf_new()) == NULL ||
2555 (kex->peer = sshbuf_new()) == NULL) {
2556 r = SSH_ERR_ALLOC_FAIL;
2559 if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2560 (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2561 (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2562 (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2563 (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2564 (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2565 (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2566 (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2567 (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2573 if (r != 0 || kexp == NULL) {
2575 if (kex->my != NULL)
2576 sshbuf_free(kex->my);
2577 if (kex->peer != NULL)
2578 sshbuf_free(kex->peer);
2590 * Restore packet state from content of blob 'm' (de-serialization).
2591 * Note that 'm' will be partially consumed on parsing or any other errors.
2594 ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2596 struct session_state *state = ssh->state;
2597 const u_char *ssh1key, *ivin, *ivout, *keyin, *keyout, *input, *output;
2598 size_t ssh1keylen, rlen, slen, ilen, olen;
2600 u_int ssh1cipher = 0;
2601 u_int64_t sent_bytes = 0, recv_bytes = 0;
2604 if ((r = sshbuf_get_u32(m, &state->remote_protocol_flags)) != 0 ||
2605 (r = sshbuf_get_u32(m, &ssh1cipher)) != 0 ||
2606 (r = sshbuf_get_string_direct(m, &ssh1key, &ssh1keylen)) != 0 ||
2607 (r = sshbuf_get_string_direct(m, &ivout, &slen)) != 0 ||
2608 (r = sshbuf_get_string_direct(m, &ivin, &rlen)) != 0)
2610 if (ssh1cipher > INT_MAX)
2611 return SSH_ERR_KEY_UNKNOWN_CIPHER;
2612 ssh_packet_set_encryption_key(ssh, ssh1key, ssh1keylen,
2614 if (cipher_get_keyiv_len(&state->send_context) != (int)slen ||
2615 cipher_get_keyiv_len(&state->receive_context) != (int)rlen)
2616 return SSH_ERR_INVALID_FORMAT;
2617 if ((r = cipher_set_keyiv(&state->send_context, ivout)) != 0 ||
2618 (r = cipher_set_keyiv(&state->receive_context, ivin)) != 0)
2621 if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2622 (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2623 (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2624 (r = sshbuf_get_u32(m, &state->rekey_limit)) != 0 ||
2625 (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2626 (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2627 (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2628 (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2629 (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2630 (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2631 (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2632 (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2633 (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2636 * We set the time here so that in post-auth privsep slave we
2637 * count from the completion of the authentication.
2639 state->rekey_time = monotime();
2640 /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2641 if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2642 (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2645 if ((r = sshbuf_get_string_direct(m, &keyout, &slen)) != 0 ||
2646 (r = sshbuf_get_string_direct(m, &keyin, &rlen)) != 0)
2648 if (cipher_get_keycontext(&state->send_context, NULL) != (int)slen ||
2649 cipher_get_keycontext(&state->receive_context, NULL) != (int)rlen)
2650 return SSH_ERR_INVALID_FORMAT;
2651 cipher_set_keycontext(&state->send_context, keyout);
2652 cipher_set_keycontext(&state->receive_context, keyin);
2654 if ((r = ssh_packet_set_compress_state(ssh, m)) != 0 ||
2655 (r = ssh_packet_set_postauth(ssh)) != 0)
2658 sshbuf_reset(state->input);
2659 sshbuf_reset(state->output);
2660 if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2661 (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2662 (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2663 (r = sshbuf_put(state->output, output, olen)) != 0)
2667 if ((r = sshbuf_get_u64(m, &sent_bytes)) != 0 ||
2668 (r = sshbuf_get_u64(m, &recv_bytes)) != 0)
2670 roam_set_bytes(sent_bytes, recv_bytes);
2673 return SSH_ERR_INVALID_FORMAT;
2674 debug3("%s: done", __func__);
2680 /* put data to the outgoing packet */
2683 sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2685 return sshbuf_put(ssh->state->outgoing_packet, v, len);
2689 sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2691 return sshbuf_putb(ssh->state->outgoing_packet, b);
2695 sshpkt_put_u8(struct ssh *ssh, u_char val)
2697 return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2701 sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2703 return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2707 sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2709 return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2713 sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2715 return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2719 sshpkt_put_cstring(struct ssh *ssh, const void *v)
2721 return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2725 sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2727 return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2730 #if defined(WITH_OPENSSL) && defined(OPENSSL_HAS_ECC)
2732 sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2734 return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2736 #endif /* WITH_OPENSSL && OPENSSL_HAS_ECC */
2740 sshpkt_put_bignum1(struct ssh *ssh, const BIGNUM *v)
2742 return sshbuf_put_bignum1(ssh->state->outgoing_packet, v);
2744 #endif /* WITH_SSH1 */
2748 sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2750 return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2752 #endif /* WITH_OPENSSL */
2754 /* fetch data from the incoming packet */
2757 sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2759 return sshbuf_get(ssh->state->incoming_packet, valp, len);
2763 sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2765 return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2769 sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2771 return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2775 sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2777 return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2781 sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2783 return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2787 sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2789 return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2793 sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2795 return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2798 #if defined(WITH_OPENSSL) && defined(OPENSSL_HAS_ECC)
2800 sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2802 return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2804 #endif /* WITH_OPENSSL && OPENSSL_HAS_ECC */
2808 sshpkt_get_bignum1(struct ssh *ssh, BIGNUM *v)
2810 return sshbuf_get_bignum1(ssh->state->incoming_packet, v);
2812 #endif /* WITH_SSH1 */
2816 sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2818 return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2820 #endif /* WITH_OPENSSL */
2823 sshpkt_get_end(struct ssh *ssh)
2825 if (sshbuf_len(ssh->state->incoming_packet) > 0)
2826 return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2831 sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2834 *lenp = sshbuf_len(ssh->state->incoming_packet);
2835 return sshbuf_ptr(ssh->state->incoming_packet);
2838 /* start a new packet */
2841 sshpkt_start(struct ssh *ssh, u_char type)
2846 DBG(debug("packet_start[%d]", type));
2847 len = compat20 ? 6 : 9;
2848 memset(buf, 0, len - 1);
2849 buf[len - 1] = type;
2850 sshbuf_reset(ssh->state->outgoing_packet);
2851 return sshbuf_put(ssh->state->outgoing_packet, buf, len);
2857 sshpkt_send(struct ssh *ssh)
2860 return ssh_packet_send2(ssh);
2862 return ssh_packet_send1(ssh);
2866 sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2872 va_start(args, fmt);
2873 vsnprintf(buf, sizeof(buf), fmt, args);
2877 if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2878 (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2879 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2880 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2881 (r = sshpkt_send(ssh)) != 0)
2884 if ((r = sshpkt_start(ssh, SSH_MSG_DISCONNECT)) != 0 ||
2885 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2886 (r = sshpkt_send(ssh)) != 0)
2892 /* roundup current message to pad bytes */
2894 sshpkt_add_padding(struct ssh *ssh, u_char pad)
2896 ssh->state->extra_pad = pad;