1 /* $OpenBSD: packet.c,v 1.264 2017/09/12 06:32:07 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/types.h>
43 #include "openbsd-compat/sys-queue.h"
44 #include <sys/socket.h>
45 #ifdef HAVE_SYS_TIME_H
46 # include <sys/time.h>
49 #include <netinet/in.h>
50 #include <netinet/ip.h>
51 #include <arpa/inet.h>
66 #include "buffer.h" /* typedefs XXX */
67 #include "key.h" /* typedefs XXX */
93 #define PACKET_MAX_SIZE (256 * 1024)
103 TAILQ_ENTRY(packet) next;
105 struct sshbuf *payload;
108 struct session_state {
110 * This variable contains the file descriptors used for
111 * communicating with the other side. connection_in is used for
112 * reading; connection_out for writing. These can be the same
113 * descriptor, in which case it is assumed to be a socket.
118 /* Protocol flags for the remote side. */
119 u_int remote_protocol_flags;
121 /* Encryption context for receiving data. Only used for decryption. */
122 struct sshcipher_ctx *receive_context;
124 /* Encryption context for sending data. Only used for encryption. */
125 struct sshcipher_ctx *send_context;
127 /* Buffer for raw input data from the socket. */
128 struct sshbuf *input;
130 /* Buffer for raw output data going to the socket. */
131 struct sshbuf *output;
133 /* Buffer for the partial outgoing packet being constructed. */
134 struct sshbuf *outgoing_packet;
136 /* Buffer for the incoming packet currently being processed. */
137 struct sshbuf *incoming_packet;
139 /* Scratch buffer for packet compression/decompression. */
140 struct sshbuf *compression_buffer;
142 /* Incoming/outgoing compression dictionaries */
143 z_stream compression_in_stream;
144 z_stream compression_out_stream;
145 int compression_in_started;
146 int compression_out_started;
147 int compression_in_failures;
148 int compression_out_failures;
151 * Flag indicating whether packet compression/decompression is
154 int packet_compression;
156 /* default maximum packet size */
157 u_int max_packet_size;
159 /* Flag indicating whether this module has been initialized. */
162 /* Set to true if the connection is interactive. */
163 int interactive_mode;
165 /* Set to true if we are the server side. */
168 /* Set to true if we are authenticated. */
169 int after_authentication;
171 int keep_alive_timeouts;
173 /* The maximum time that we will wait to send or receive a packet */
174 int packet_timeout_ms;
176 /* Session key information for Encryption and MAC */
177 struct newkeys *newkeys[MODE_MAX];
178 struct packet_state p_read, p_send;
180 /* Volume-based rekeying */
181 u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
183 /* Time-based rekeying */
184 u_int32_t rekey_interval; /* how often in seconds */
185 time_t rekey_time; /* time of last rekeying */
187 /* roundup current message to extra_pad bytes */
190 /* XXX discard incoming data after MAC error */
191 u_int packet_discard;
192 size_t packet_discard_mac_already;
193 struct sshmac *packet_discard_mac;
195 /* Used in packet_read_poll2() */
198 /* Used in packet_send2 */
201 /* Used in ssh_packet_send_mux() */
204 /* Used in packet_set_interactive */
205 int set_interactive_called;
207 /* Used in packet_set_maxsize */
208 int set_maxsize_called;
210 /* One-off warning about weak ciphers */
211 int cipher_warning_done;
213 /* Hook for fuzzing inbound packets */
214 ssh_packet_hook_fn *hook_in;
217 TAILQ_HEAD(, packet) outgoing;
221 ssh_alloc_session_state(void)
223 struct ssh *ssh = NULL;
224 struct session_state *state = NULL;
226 if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
227 (state = calloc(1, sizeof(*state))) == NULL ||
228 (state->input = sshbuf_new()) == NULL ||
229 (state->output = sshbuf_new()) == NULL ||
230 (state->outgoing_packet = sshbuf_new()) == NULL ||
231 (state->incoming_packet = sshbuf_new()) == NULL)
233 TAILQ_INIT(&state->outgoing);
234 TAILQ_INIT(&ssh->private_keys);
235 TAILQ_INIT(&ssh->public_keys);
236 state->connection_in = -1;
237 state->connection_out = -1;
238 state->max_packet_size = 32768;
239 state->packet_timeout_ms = -1;
240 state->p_send.packets = state->p_read.packets = 0;
241 state->initialized = 1;
243 * ssh_packet_send2() needs to queue packets until
244 * we've done the initial key exchange.
251 sshbuf_free(state->input);
252 sshbuf_free(state->output);
253 sshbuf_free(state->incoming_packet);
254 sshbuf_free(state->outgoing_packet);
262 ssh_packet_set_input_hook(struct ssh *ssh, ssh_packet_hook_fn *hook, void *ctx)
264 ssh->state->hook_in = hook;
265 ssh->state->hook_in_ctx = ctx;
268 /* Returns nonzero if rekeying is in progress */
270 ssh_packet_is_rekeying(struct ssh *ssh)
272 return ssh->state->rekeying ||
273 (ssh->kex != NULL && ssh->kex->done == 0);
277 * Sets the descriptors used for communication.
280 ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
282 struct session_state *state;
283 const struct sshcipher *none = cipher_by_name("none");
287 error("%s: cannot load cipher 'none'", __func__);
291 ssh = ssh_alloc_session_state();
293 error("%s: cound not allocate state", __func__);
297 state->connection_in = fd_in;
298 state->connection_out = fd_out;
299 if ((r = cipher_init(&state->send_context, none,
300 (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
301 (r = cipher_init(&state->receive_context, none,
302 (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
303 error("%s: cipher_init failed: %s", __func__, ssh_err(r));
304 free(ssh); /* XXX need ssh_free_session_state? */
307 state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
309 * Cache the IP address of the remote connection for use in error
310 * messages that might be generated after the connection has closed.
312 (void)ssh_remote_ipaddr(ssh);
317 ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
319 struct session_state *state = ssh->state;
321 if (timeout <= 0 || count <= 0) {
322 state->packet_timeout_ms = -1;
325 if ((INT_MAX / 1000) / count < timeout)
326 state->packet_timeout_ms = INT_MAX;
328 state->packet_timeout_ms = timeout * count * 1000;
332 ssh_packet_set_mux(struct ssh *ssh)
335 ssh->state->rekeying = 0;
339 ssh_packet_get_mux(struct ssh *ssh)
341 return ssh->state->mux;
345 ssh_packet_set_log_preamble(struct ssh *ssh, const char *fmt, ...)
350 free(ssh->log_preamble);
352 ssh->log_preamble = NULL;
355 r = vasprintf(&ssh->log_preamble, fmt, args);
357 if (r < 0 || ssh->log_preamble == NULL)
358 return SSH_ERR_ALLOC_FAIL;
364 ssh_packet_stop_discard(struct ssh *ssh)
366 struct session_state *state = ssh->state;
369 if (state->packet_discard_mac) {
371 size_t dlen = PACKET_MAX_SIZE;
373 if (dlen > state->packet_discard_mac_already)
374 dlen -= state->packet_discard_mac_already;
375 memset(buf, 'a', sizeof(buf));
376 while (sshbuf_len(state->incoming_packet) < dlen)
377 if ((r = sshbuf_put(state->incoming_packet, buf,
380 (void) mac_compute(state->packet_discard_mac,
382 sshbuf_ptr(state->incoming_packet), dlen,
385 logit("Finished discarding for %.200s port %d",
386 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
387 return SSH_ERR_MAC_INVALID;
391 ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
392 struct sshmac *mac, size_t mac_already, u_int discard)
394 struct session_state *state = ssh->state;
397 if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
398 if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
400 return SSH_ERR_MAC_INVALID;
403 * Record number of bytes over which the mac has already
404 * been computed in order to minimize timing attacks.
406 if (mac && mac->enabled) {
407 state->packet_discard_mac = mac;
408 state->packet_discard_mac_already = mac_already;
410 if (sshbuf_len(state->input) >= discard)
411 return ssh_packet_stop_discard(ssh);
412 state->packet_discard = discard - sshbuf_len(state->input);
416 /* Returns 1 if remote host is connected via socket, 0 if not. */
419 ssh_packet_connection_is_on_socket(struct ssh *ssh)
421 struct session_state *state = ssh->state;
422 struct sockaddr_storage from, to;
423 socklen_t fromlen, tolen;
425 if (state->connection_in == -1 || state->connection_out == -1)
428 /* filedescriptors in and out are the same, so it's a socket */
429 if (state->connection_in == state->connection_out)
431 fromlen = sizeof(from);
432 memset(&from, 0, sizeof(from));
433 if (getpeername(state->connection_in, (struct sockaddr *)&from,
437 memset(&to, 0, sizeof(to));
438 if (getpeername(state->connection_out, (struct sockaddr *)&to,
441 if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
443 if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
449 ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
452 *ibytes = ssh->state->p_read.bytes;
454 *obytes = ssh->state->p_send.bytes;
458 ssh_packet_connection_af(struct ssh *ssh)
460 struct sockaddr_storage to;
461 socklen_t tolen = sizeof(to);
463 memset(&to, 0, sizeof(to));
464 if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
468 if (to.ss_family == AF_INET6 &&
469 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr))
475 /* Sets the connection into non-blocking mode. */
478 ssh_packet_set_nonblocking(struct ssh *ssh)
480 /* Set the socket into non-blocking mode. */
481 set_nonblock(ssh->state->connection_in);
483 if (ssh->state->connection_out != ssh->state->connection_in)
484 set_nonblock(ssh->state->connection_out);
487 /* Returns the socket used for reading. */
490 ssh_packet_get_connection_in(struct ssh *ssh)
492 return ssh->state->connection_in;
495 /* Returns the descriptor used for writing. */
498 ssh_packet_get_connection_out(struct ssh *ssh)
500 return ssh->state->connection_out;
504 * Returns the IP-address of the remote host as a string. The returned
505 * string must not be freed.
509 ssh_remote_ipaddr(struct ssh *ssh)
511 const int sock = ssh->state->connection_in;
513 /* Check whether we have cached the ipaddr. */
514 if (ssh->remote_ipaddr == NULL) {
515 if (ssh_packet_connection_is_on_socket(ssh)) {
516 ssh->remote_ipaddr = get_peer_ipaddr(sock);
517 ssh->remote_port = get_peer_port(sock);
518 ssh->local_ipaddr = get_local_ipaddr(sock);
519 ssh->local_port = get_local_port(sock);
521 ssh->remote_ipaddr = strdup("UNKNOWN");
522 ssh->remote_port = 65535;
523 ssh->local_ipaddr = strdup("UNKNOWN");
524 ssh->local_port = 65535;
527 return ssh->remote_ipaddr;
530 /* Returns the port number of the remote host. */
533 ssh_remote_port(struct ssh *ssh)
535 (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
536 return ssh->remote_port;
540 * Returns the IP-address of the local host as a string. The returned
541 * string must not be freed.
545 ssh_local_ipaddr(struct ssh *ssh)
547 (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
548 return ssh->local_ipaddr;
551 /* Returns the port number of the local host. */
554 ssh_local_port(struct ssh *ssh)
556 (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
557 return ssh->local_port;
560 /* Closes the connection and clears and frees internal data structures. */
563 ssh_packet_close_internal(struct ssh *ssh, int do_close)
565 struct session_state *state = ssh->state;
568 if (!state->initialized)
570 state->initialized = 0;
572 if (state->connection_in == state->connection_out) {
573 close(state->connection_out);
575 close(state->connection_in);
576 close(state->connection_out);
579 sshbuf_free(state->input);
580 sshbuf_free(state->output);
581 sshbuf_free(state->outgoing_packet);
582 sshbuf_free(state->incoming_packet);
583 for (mode = 0; mode < MODE_MAX; mode++) {
584 kex_free_newkeys(state->newkeys[mode]); /* current keys */
585 state->newkeys[mode] = NULL;
586 ssh_clear_newkeys(ssh, mode); /* next keys */
588 /* comression state is in shared mem, so we can only release it once */
589 if (do_close && state->compression_buffer) {
590 sshbuf_free(state->compression_buffer);
591 if (state->compression_out_started) {
592 z_streamp stream = &state->compression_out_stream;
593 debug("compress outgoing: "
594 "raw data %llu, compressed %llu, factor %.2f",
595 (unsigned long long)stream->total_in,
596 (unsigned long long)stream->total_out,
597 stream->total_in == 0 ? 0.0 :
598 (double) stream->total_out / stream->total_in);
599 if (state->compression_out_failures == 0)
602 if (state->compression_in_started) {
603 z_streamp stream = &state->compression_in_stream;
604 debug("compress incoming: "
605 "raw data %llu, compressed %llu, factor %.2f",
606 (unsigned long long)stream->total_out,
607 (unsigned long long)stream->total_in,
608 stream->total_out == 0 ? 0.0 :
609 (double) stream->total_in / stream->total_out);
610 if (state->compression_in_failures == 0)
614 cipher_free(state->send_context);
615 cipher_free(state->receive_context);
616 state->send_context = state->receive_context = NULL;
618 free(ssh->remote_ipaddr);
619 ssh->remote_ipaddr = NULL;
626 ssh_packet_close(struct ssh *ssh)
628 ssh_packet_close_internal(ssh, 1);
632 ssh_packet_clear_keys(struct ssh *ssh)
634 ssh_packet_close_internal(ssh, 0);
637 /* Sets remote side protocol flags. */
640 ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
642 ssh->state->remote_protocol_flags = protocol_flags;
645 /* Returns the remote protocol flags set earlier by the above function. */
648 ssh_packet_get_protocol_flags(struct ssh *ssh)
650 return ssh->state->remote_protocol_flags;
654 * Starts packet compression from the next packet on in both directions.
655 * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
659 ssh_packet_init_compression(struct ssh *ssh)
661 if (!ssh->state->compression_buffer &&
662 ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
663 return SSH_ERR_ALLOC_FAIL;
668 start_compression_out(struct ssh *ssh, int level)
670 if (level < 1 || level > 9)
671 return SSH_ERR_INVALID_ARGUMENT;
672 debug("Enabling compression at level %d.", level);
673 if (ssh->state->compression_out_started == 1)
674 deflateEnd(&ssh->state->compression_out_stream);
675 switch (deflateInit(&ssh->state->compression_out_stream, level)) {
677 ssh->state->compression_out_started = 1;
680 return SSH_ERR_ALLOC_FAIL;
682 return SSH_ERR_INTERNAL_ERROR;
688 start_compression_in(struct ssh *ssh)
690 if (ssh->state->compression_in_started == 1)
691 inflateEnd(&ssh->state->compression_in_stream);
692 switch (inflateInit(&ssh->state->compression_in_stream)) {
694 ssh->state->compression_in_started = 1;
697 return SSH_ERR_ALLOC_FAIL;
699 return SSH_ERR_INTERNAL_ERROR;
705 ssh_packet_start_compression(struct ssh *ssh, int level)
709 if (ssh->state->packet_compression)
710 return SSH_ERR_INTERNAL_ERROR;
711 ssh->state->packet_compression = 1;
712 if ((r = ssh_packet_init_compression(ssh)) != 0 ||
713 (r = start_compression_in(ssh)) != 0 ||
714 (r = start_compression_out(ssh, level)) != 0)
719 /* XXX remove need for separate compression buffer */
721 compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
726 if (ssh->state->compression_out_started != 1)
727 return SSH_ERR_INTERNAL_ERROR;
729 /* This case is not handled below. */
730 if (sshbuf_len(in) == 0)
733 /* Input is the contents of the input buffer. */
734 if ((ssh->state->compression_out_stream.next_in =
735 sshbuf_mutable_ptr(in)) == NULL)
736 return SSH_ERR_INTERNAL_ERROR;
737 ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
739 /* Loop compressing until deflate() returns with avail_out != 0. */
741 /* Set up fixed-size output buffer. */
742 ssh->state->compression_out_stream.next_out = buf;
743 ssh->state->compression_out_stream.avail_out = sizeof(buf);
745 /* Compress as much data into the buffer as possible. */
746 status = deflate(&ssh->state->compression_out_stream,
750 return SSH_ERR_ALLOC_FAIL;
752 /* Append compressed data to output_buffer. */
753 if ((r = sshbuf_put(out, buf, sizeof(buf) -
754 ssh->state->compression_out_stream.avail_out)) != 0)
759 ssh->state->compression_out_failures++;
760 return SSH_ERR_INVALID_FORMAT;
762 } while (ssh->state->compression_out_stream.avail_out == 0);
767 uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
772 if (ssh->state->compression_in_started != 1)
773 return SSH_ERR_INTERNAL_ERROR;
775 if ((ssh->state->compression_in_stream.next_in =
776 sshbuf_mutable_ptr(in)) == NULL)
777 return SSH_ERR_INTERNAL_ERROR;
778 ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
781 /* Set up fixed-size output buffer. */
782 ssh->state->compression_in_stream.next_out = buf;
783 ssh->state->compression_in_stream.avail_out = sizeof(buf);
785 status = inflate(&ssh->state->compression_in_stream,
789 if ((r = sshbuf_put(out, buf, sizeof(buf) -
790 ssh->state->compression_in_stream.avail_out)) != 0)
795 * Comments in zlib.h say that we should keep calling
796 * inflate() until we get an error. This appears to
797 * be the error that we get.
801 return SSH_ERR_INVALID_FORMAT;
803 return SSH_ERR_ALLOC_FAIL;
806 ssh->state->compression_in_failures++;
807 return SSH_ERR_INTERNAL_ERROR;
814 ssh_clear_newkeys(struct ssh *ssh, int mode)
816 if (ssh->kex && ssh->kex->newkeys[mode]) {
817 kex_free_newkeys(ssh->kex->newkeys[mode]);
818 ssh->kex->newkeys[mode] = NULL;
823 ssh_set_newkeys(struct ssh *ssh, int mode)
825 struct session_state *state = ssh->state;
828 struct sshcomp *comp;
829 struct sshcipher_ctx **ccp;
830 struct packet_state *ps;
831 u_int64_t *max_blocks;
835 debug2("set_newkeys: mode %d", mode);
837 if (mode == MODE_OUT) {
838 ccp = &state->send_context;
839 crypt_type = CIPHER_ENCRYPT;
841 max_blocks = &state->max_blocks_out;
843 ccp = &state->receive_context;
844 crypt_type = CIPHER_DECRYPT;
846 max_blocks = &state->max_blocks_in;
848 if (state->newkeys[mode] != NULL) {
849 debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
850 "output %llu bytes %llu blocks",
851 (unsigned long long)state->p_read.bytes,
852 (unsigned long long)state->p_read.blocks,
853 (unsigned long long)state->p_send.bytes,
854 (unsigned long long)state->p_send.blocks);
857 kex_free_newkeys(state->newkeys[mode]);
858 state->newkeys[mode] = NULL;
860 /* note that both bytes and the seqnr are not reset */
861 ps->packets = ps->blocks = 0;
862 /* move newkeys from kex to state */
863 if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
864 return SSH_ERR_INTERNAL_ERROR;
865 ssh->kex->newkeys[mode] = NULL;
866 enc = &state->newkeys[mode]->enc;
867 mac = &state->newkeys[mode]->mac;
868 comp = &state->newkeys[mode]->comp;
869 if (cipher_authlen(enc->cipher) == 0) {
870 if ((r = mac_init(mac)) != 0)
874 DBG(debug("cipher_init_context: %d", mode));
875 if ((r = cipher_init(ccp, enc->cipher, enc->key, enc->key_len,
876 enc->iv, enc->iv_len, crypt_type)) != 0)
878 if (!state->cipher_warning_done &&
879 (wmsg = cipher_warning_message(*ccp)) != NULL) {
880 error("Warning: %s", wmsg);
881 state->cipher_warning_done = 1;
883 /* Deleting the keys does not gain extra security */
884 /* explicit_bzero(enc->iv, enc->block_size);
885 explicit_bzero(enc->key, enc->key_len);
886 explicit_bzero(mac->key, mac->key_len); */
887 if ((comp->type == COMP_ZLIB ||
888 (comp->type == COMP_DELAYED &&
889 state->after_authentication)) && comp->enabled == 0) {
890 if ((r = ssh_packet_init_compression(ssh)) < 0)
892 if (mode == MODE_OUT) {
893 if ((r = start_compression_out(ssh, 6)) != 0)
896 if ((r = start_compression_in(ssh)) != 0)
902 * The 2^(blocksize*2) limit is too expensive for 3DES,
903 * so enforce a 1GB limit for small blocksizes.
904 * See RFC4344 section 3.2.
906 if (enc->block_size >= 16)
907 *max_blocks = (u_int64_t)1 << (enc->block_size*2);
909 *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
910 if (state->rekey_limit)
911 *max_blocks = MINIMUM(*max_blocks,
912 state->rekey_limit / enc->block_size);
913 debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
917 #define MAX_PACKETS (1U<<31)
919 ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
921 struct session_state *state = ssh->state;
922 u_int32_t out_blocks;
924 /* XXX client can't cope with rekeying pre-auth */
925 if (!state->after_authentication)
928 /* Haven't keyed yet or KEX in progress. */
929 if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
932 /* Peer can't rekey */
933 if (ssh->compat & SSH_BUG_NOREKEY)
937 * Permit one packet in or out per rekey - this allows us to
938 * make progress when rekey limits are very small.
940 if (state->p_send.packets == 0 && state->p_read.packets == 0)
943 /* Time-based rekeying */
944 if (state->rekey_interval != 0 &&
945 (int64_t)state->rekey_time + state->rekey_interval <= monotime())
949 * Always rekey when MAX_PACKETS sent in either direction
950 * As per RFC4344 section 3.1 we do this after 2^31 packets.
952 if (state->p_send.packets > MAX_PACKETS ||
953 state->p_read.packets > MAX_PACKETS)
956 /* Rekey after (cipher-specific) maxiumum blocks */
957 out_blocks = ROUNDUP(outbound_packet_len,
958 state->newkeys[MODE_OUT]->enc.block_size);
959 return (state->max_blocks_out &&
960 (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
961 (state->max_blocks_in &&
962 (state->p_read.blocks > state->max_blocks_in));
966 * Delayed compression for SSH2 is enabled after authentication:
967 * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
968 * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
971 ssh_packet_enable_delayed_compress(struct ssh *ssh)
973 struct session_state *state = ssh->state;
974 struct sshcomp *comp = NULL;
978 * Remember that we are past the authentication step, so rekeying
979 * with COMP_DELAYED will turn on compression immediately.
981 state->after_authentication = 1;
982 for (mode = 0; mode < MODE_MAX; mode++) {
983 /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
984 if (state->newkeys[mode] == NULL)
986 comp = &state->newkeys[mode]->comp;
987 if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
988 if ((r = ssh_packet_init_compression(ssh)) != 0)
990 if (mode == MODE_OUT) {
991 if ((r = start_compression_out(ssh, 6)) != 0)
994 if ((r = start_compression_in(ssh)) != 0)
1003 /* Used to mute debug logging for noisy packet types */
1005 ssh_packet_log_type(u_char type)
1008 case SSH2_MSG_CHANNEL_DATA:
1009 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1010 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1018 * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1021 ssh_packet_send2_wrapped(struct ssh *ssh)
1023 struct session_state *state = ssh->state;
1024 u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1025 u_char tmp, padlen, pad = 0;
1026 u_int authlen = 0, aadlen = 0;
1028 struct sshenc *enc = NULL;
1029 struct sshmac *mac = NULL;
1030 struct sshcomp *comp = NULL;
1033 if (state->newkeys[MODE_OUT] != NULL) {
1034 enc = &state->newkeys[MODE_OUT]->enc;
1035 mac = &state->newkeys[MODE_OUT]->mac;
1036 comp = &state->newkeys[MODE_OUT]->comp;
1037 /* disable mac for authenticated encryption */
1038 if ((authlen = cipher_authlen(enc->cipher)) != 0)
1041 block_size = enc ? enc->block_size : 8;
1042 aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1044 type = (sshbuf_ptr(state->outgoing_packet))[5];
1045 if (ssh_packet_log_type(type))
1046 debug3("send packet: type %u", type);
1048 fprintf(stderr, "plain: ");
1049 sshbuf_dump(state->outgoing_packet, stderr);
1052 if (comp && comp->enabled) {
1053 len = sshbuf_len(state->outgoing_packet);
1054 /* skip header, compress only payload */
1055 if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1057 sshbuf_reset(state->compression_buffer);
1058 if ((r = compress_buffer(ssh, state->outgoing_packet,
1059 state->compression_buffer)) != 0)
1061 sshbuf_reset(state->outgoing_packet);
1062 if ((r = sshbuf_put(state->outgoing_packet,
1063 "\0\0\0\0\0", 5)) != 0 ||
1064 (r = sshbuf_putb(state->outgoing_packet,
1065 state->compression_buffer)) != 0)
1067 DBG(debug("compression: raw %d compressed %zd", len,
1068 sshbuf_len(state->outgoing_packet)));
1071 /* sizeof (packet_len + pad_len + payload) */
1072 len = sshbuf_len(state->outgoing_packet);
1075 * calc size of padding, alloc space, get random data,
1076 * minimum padding is 4 bytes
1078 len -= aadlen; /* packet length is not encrypted for EtM modes */
1079 padlen = block_size - (len % block_size);
1081 padlen += block_size;
1082 if (state->extra_pad) {
1083 tmp = state->extra_pad;
1085 ROUNDUP(state->extra_pad, block_size);
1086 /* check if roundup overflowed */
1087 if (state->extra_pad < tmp)
1088 return SSH_ERR_INVALID_ARGUMENT;
1089 tmp = (len + padlen) % state->extra_pad;
1090 /* Check whether pad calculation below will underflow */
1091 if (tmp > state->extra_pad)
1092 return SSH_ERR_INVALID_ARGUMENT;
1093 pad = state->extra_pad - tmp;
1094 DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1095 __func__, pad, len, padlen, state->extra_pad));
1098 /* Check whether padlen calculation overflowed */
1100 return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1101 state->extra_pad = 0;
1103 if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1105 if (enc && !cipher_ctx_is_plaintext(state->send_context)) {
1106 /* random padding */
1107 arc4random_buf(cp, padlen);
1110 explicit_bzero(cp, padlen);
1112 /* sizeof (packet_len + pad_len + payload + padding) */
1113 len = sshbuf_len(state->outgoing_packet);
1114 cp = sshbuf_mutable_ptr(state->outgoing_packet);
1116 r = SSH_ERR_INTERNAL_ERROR;
1119 /* packet_length includes payload, padding and padding length field */
1120 POKE_U32(cp, len - 4);
1122 DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1123 len, padlen, aadlen));
1125 /* compute MAC over seqnr and packet(length fields, payload, padding) */
1126 if (mac && mac->enabled && !mac->etm) {
1127 if ((r = mac_compute(mac, state->p_send.seqnr,
1128 sshbuf_ptr(state->outgoing_packet), len,
1129 macbuf, sizeof(macbuf))) != 0)
1131 DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1133 /* encrypt packet and append to output buffer. */
1134 if ((r = sshbuf_reserve(state->output,
1135 sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1137 if ((r = cipher_crypt(state->send_context, state->p_send.seqnr, cp,
1138 sshbuf_ptr(state->outgoing_packet),
1139 len - aadlen, aadlen, authlen)) != 0)
1141 /* append unencrypted MAC */
1142 if (mac && mac->enabled) {
1144 /* EtM: compute mac over aadlen + cipher text */
1145 if ((r = mac_compute(mac, state->p_send.seqnr,
1146 cp, len, macbuf, sizeof(macbuf))) != 0)
1148 DBG(debug("done calc MAC(EtM) out #%d",
1149 state->p_send.seqnr));
1151 if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1155 fprintf(stderr, "encrypted: ");
1156 sshbuf_dump(state->output, stderr);
1158 /* increment sequence number for outgoing packets */
1159 if (++state->p_send.seqnr == 0)
1160 logit("outgoing seqnr wraps around");
1161 if (++state->p_send.packets == 0)
1162 if (!(ssh->compat & SSH_BUG_NOREKEY))
1163 return SSH_ERR_NEED_REKEY;
1164 state->p_send.blocks += len / block_size;
1165 state->p_send.bytes += len;
1166 sshbuf_reset(state->outgoing_packet);
1168 if (type == SSH2_MSG_NEWKEYS)
1169 r = ssh_set_newkeys(ssh, MODE_OUT);
1170 else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1171 r = ssh_packet_enable_delayed_compress(ssh);
1178 /* returns non-zero if the specified packet type is usec by KEX */
1180 ssh_packet_type_is_kex(u_char type)
1183 type >= SSH2_MSG_TRANSPORT_MIN &&
1184 type <= SSH2_MSG_TRANSPORT_MAX &&
1185 type != SSH2_MSG_SERVICE_REQUEST &&
1186 type != SSH2_MSG_SERVICE_ACCEPT &&
1187 type != SSH2_MSG_EXT_INFO;
1191 ssh_packet_send2(struct ssh *ssh)
1193 struct session_state *state = ssh->state;
1198 if (sshbuf_len(state->outgoing_packet) < 6)
1199 return SSH_ERR_INTERNAL_ERROR;
1200 type = sshbuf_ptr(state->outgoing_packet)[5];
1201 need_rekey = !ssh_packet_type_is_kex(type) &&
1202 ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1205 * During rekeying we can only send key exchange messages.
1206 * Queue everything else.
1208 if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1210 debug3("%s: rekex triggered", __func__);
1211 debug("enqueue packet: %u", type);
1212 p = calloc(1, sizeof(*p));
1214 return SSH_ERR_ALLOC_FAIL;
1216 p->payload = state->outgoing_packet;
1217 TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1218 state->outgoing_packet = sshbuf_new();
1219 if (state->outgoing_packet == NULL)
1220 return SSH_ERR_ALLOC_FAIL;
1223 * This packet triggered a rekey, so send the
1225 * NB. reenters this function via kex_start_rekex().
1227 return kex_start_rekex(ssh);
1232 /* rekeying starts with sending KEXINIT */
1233 if (type == SSH2_MSG_KEXINIT)
1234 state->rekeying = 1;
1236 if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1239 /* after a NEWKEYS message we can send the complete queue */
1240 if (type == SSH2_MSG_NEWKEYS) {
1241 state->rekeying = 0;
1242 state->rekey_time = monotime();
1243 while ((p = TAILQ_FIRST(&state->outgoing))) {
1246 * If this packet triggers a rekex, then skip the
1247 * remaining packets in the queue for now.
1248 * NB. re-enters this function via kex_start_rekex.
1250 if (ssh_packet_need_rekeying(ssh,
1251 sshbuf_len(p->payload))) {
1252 debug3("%s: queued packet triggered rekex",
1254 return kex_start_rekex(ssh);
1256 debug("dequeue packet: %u", type);
1257 sshbuf_free(state->outgoing_packet);
1258 state->outgoing_packet = p->payload;
1259 TAILQ_REMOVE(&state->outgoing, p, next);
1260 memset(p, 0, sizeof(*p));
1262 if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1270 * Waits until a packet has been received, and returns its type. Note that
1271 * no other data is processed until this returns, so this function should not
1272 * be used during the interactive session.
1276 ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1278 struct session_state *state = ssh->state;
1279 int len, r, ms_remain;
1282 struct timeval timeout, start, *timeoutp = NULL;
1284 DBG(debug("packet_read()"));
1286 setp = calloc(howmany(state->connection_in + 1,
1287 NFDBITS), sizeof(fd_mask));
1289 return SSH_ERR_ALLOC_FAIL;
1292 * Since we are blocking, ensure that all written packets have
1295 if ((r = ssh_packet_write_wait(ssh)) != 0)
1298 /* Stay in the loop until we have received a complete packet. */
1300 /* Try to read a packet from the buffer. */
1301 r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1304 /* If we got a packet, return it. */
1305 if (*typep != SSH_MSG_NONE)
1308 * Otherwise, wait for some data to arrive, add it to the
1309 * buffer, and try again.
1311 memset(setp, 0, howmany(state->connection_in + 1,
1312 NFDBITS) * sizeof(fd_mask));
1313 FD_SET(state->connection_in, setp);
1315 if (state->packet_timeout_ms > 0) {
1316 ms_remain = state->packet_timeout_ms;
1317 timeoutp = &timeout;
1319 /* Wait for some data to arrive. */
1321 if (state->packet_timeout_ms != -1) {
1322 ms_to_timeval(&timeout, ms_remain);
1323 gettimeofday(&start, NULL);
1325 if ((r = select(state->connection_in + 1, setp,
1326 NULL, NULL, timeoutp)) >= 0)
1328 if (errno != EAGAIN && errno != EINTR &&
1329 errno != EWOULDBLOCK)
1331 if (state->packet_timeout_ms == -1)
1333 ms_subtract_diff(&start, &ms_remain);
1334 if (ms_remain <= 0) {
1340 r = SSH_ERR_CONN_TIMEOUT;
1343 /* Read data from the socket. */
1344 len = read(state->connection_in, buf, sizeof(buf));
1346 r = SSH_ERR_CONN_CLOSED;
1350 r = SSH_ERR_SYSTEM_ERROR;
1354 /* Append it to the buffer. */
1355 if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1364 ssh_packet_read(struct ssh *ssh)
1369 if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1370 fatal("%s: %s", __func__, ssh_err(r));
1375 * Waits until a packet has been received, verifies that its type matches
1376 * that given, and gives a fatal error and exits if there is a mismatch.
1380 ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1385 if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1387 if (type != expected_type) {
1388 if ((r = sshpkt_disconnect(ssh,
1389 "Protocol error: expected packet type %d, got %d",
1390 expected_type, type)) != 0)
1392 return SSH_ERR_PROTOCOL_ERROR;
1398 ssh_packet_read_poll2_mux(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1400 struct session_state *state = ssh->state;
1406 return SSH_ERR_INTERNAL_ERROR;
1407 *typep = SSH_MSG_NONE;
1408 cp = sshbuf_ptr(state->input);
1409 if (state->packlen == 0) {
1410 if (sshbuf_len(state->input) < 4 + 1)
1411 return 0; /* packet is incomplete */
1412 state->packlen = PEEK_U32(cp);
1413 if (state->packlen < 4 + 1 ||
1414 state->packlen > PACKET_MAX_SIZE)
1415 return SSH_ERR_MESSAGE_INCOMPLETE;
1417 need = state->packlen + 4;
1418 if (sshbuf_len(state->input) < need)
1419 return 0; /* packet is incomplete */
1420 sshbuf_reset(state->incoming_packet);
1421 if ((r = sshbuf_put(state->incoming_packet, cp + 4,
1422 state->packlen)) != 0 ||
1423 (r = sshbuf_consume(state->input, need)) != 0 ||
1424 (r = sshbuf_get_u8(state->incoming_packet, NULL)) != 0 ||
1425 (r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1427 if (ssh_packet_log_type(*typep))
1428 debug3("%s: type %u", __func__, *typep);
1429 /* sshbuf_dump(state->incoming_packet, stderr); */
1430 /* reset for next packet */
1436 ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1438 struct session_state *state = ssh->state;
1441 u_int maclen, aadlen = 0, authlen = 0, block_size;
1442 struct sshenc *enc = NULL;
1443 struct sshmac *mac = NULL;
1444 struct sshcomp *comp = NULL;
1448 return ssh_packet_read_poll2_mux(ssh, typep, seqnr_p);
1450 *typep = SSH_MSG_NONE;
1452 if (state->packet_discard)
1455 if (state->newkeys[MODE_IN] != NULL) {
1456 enc = &state->newkeys[MODE_IN]->enc;
1457 mac = &state->newkeys[MODE_IN]->mac;
1458 comp = &state->newkeys[MODE_IN]->comp;
1459 /* disable mac for authenticated encryption */
1460 if ((authlen = cipher_authlen(enc->cipher)) != 0)
1463 maclen = mac && mac->enabled ? mac->mac_len : 0;
1464 block_size = enc ? enc->block_size : 8;
1465 aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1467 if (aadlen && state->packlen == 0) {
1468 if (cipher_get_length(state->receive_context,
1469 &state->packlen, state->p_read.seqnr,
1470 sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1472 if (state->packlen < 1 + 4 ||
1473 state->packlen > PACKET_MAX_SIZE) {
1475 sshbuf_dump(state->input, stderr);
1477 logit("Bad packet length %u.", state->packlen);
1478 if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1480 return SSH_ERR_CONN_CORRUPT;
1482 sshbuf_reset(state->incoming_packet);
1483 } else if (state->packlen == 0) {
1485 * check if input size is less than the cipher block size,
1486 * decrypt first block and extract length of incoming packet
1488 if (sshbuf_len(state->input) < block_size)
1490 sshbuf_reset(state->incoming_packet);
1491 if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1494 if ((r = cipher_crypt(state->receive_context,
1495 state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1496 block_size, 0, 0)) != 0)
1498 state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1499 if (state->packlen < 1 + 4 ||
1500 state->packlen > PACKET_MAX_SIZE) {
1502 fprintf(stderr, "input: \n");
1503 sshbuf_dump(state->input, stderr);
1504 fprintf(stderr, "incoming_packet: \n");
1505 sshbuf_dump(state->incoming_packet, stderr);
1507 logit("Bad packet length %u.", state->packlen);
1508 return ssh_packet_start_discard(ssh, enc, mac, 0,
1511 if ((r = sshbuf_consume(state->input, block_size)) != 0)
1514 DBG(debug("input: packet len %u", state->packlen+4));
1517 /* only the payload is encrypted */
1518 need = state->packlen;
1521 * the payload size and the payload are encrypted, but we
1522 * have a partial packet of block_size bytes
1524 need = 4 + state->packlen - block_size;
1526 DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1527 " aadlen %d", block_size, need, maclen, authlen, aadlen));
1528 if (need % block_size != 0) {
1529 logit("padding error: need %d block %d mod %d",
1530 need, block_size, need % block_size);
1531 return ssh_packet_start_discard(ssh, enc, mac, 0,
1532 PACKET_MAX_SIZE - block_size);
1535 * check if the entire packet has been received and
1536 * decrypt into incoming_packet:
1537 * 'aadlen' bytes are unencrypted, but authenticated.
1538 * 'need' bytes are encrypted, followed by either
1539 * 'authlen' bytes of authentication tag or
1540 * 'maclen' bytes of message authentication code.
1542 if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1543 return 0; /* packet is incomplete */
1545 fprintf(stderr, "read_poll enc/full: ");
1546 sshbuf_dump(state->input, stderr);
1548 /* EtM: check mac over encrypted input */
1549 if (mac && mac->enabled && mac->etm) {
1550 if ((r = mac_check(mac, state->p_read.seqnr,
1551 sshbuf_ptr(state->input), aadlen + need,
1552 sshbuf_ptr(state->input) + aadlen + need + authlen,
1554 if (r == SSH_ERR_MAC_INVALID)
1555 logit("Corrupted MAC on input.");
1559 if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1562 if ((r = cipher_crypt(state->receive_context, state->p_read.seqnr, cp,
1563 sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1565 if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1567 if (mac && mac->enabled) {
1568 /* Not EtM: check MAC over cleartext */
1569 if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1570 sshbuf_ptr(state->incoming_packet),
1571 sshbuf_len(state->incoming_packet),
1572 sshbuf_ptr(state->input), maclen)) != 0) {
1573 if (r != SSH_ERR_MAC_INVALID)
1575 logit("Corrupted MAC on input.");
1576 if (need + block_size > PACKET_MAX_SIZE)
1577 return SSH_ERR_INTERNAL_ERROR;
1578 return ssh_packet_start_discard(ssh, enc, mac,
1579 sshbuf_len(state->incoming_packet),
1580 PACKET_MAX_SIZE - need - block_size);
1582 /* Remove MAC from input buffer */
1583 DBG(debug("MAC #%d ok", state->p_read.seqnr));
1584 if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1587 if (seqnr_p != NULL)
1588 *seqnr_p = state->p_read.seqnr;
1589 if (++state->p_read.seqnr == 0)
1590 logit("incoming seqnr wraps around");
1591 if (++state->p_read.packets == 0)
1592 if (!(ssh->compat & SSH_BUG_NOREKEY))
1593 return SSH_ERR_NEED_REKEY;
1594 state->p_read.blocks += (state->packlen + 4) / block_size;
1595 state->p_read.bytes += state->packlen + 4;
1598 padlen = sshbuf_ptr(state->incoming_packet)[4];
1599 DBG(debug("input: padlen %d", padlen));
1601 if ((r = sshpkt_disconnect(ssh,
1602 "Corrupted padlen %d on input.", padlen)) != 0 ||
1603 (r = ssh_packet_write_wait(ssh)) != 0)
1605 return SSH_ERR_CONN_CORRUPT;
1608 /* skip packet size + padlen, discard padding */
1609 if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1610 ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1613 DBG(debug("input: len before de-compress %zd",
1614 sshbuf_len(state->incoming_packet)));
1615 if (comp && comp->enabled) {
1616 sshbuf_reset(state->compression_buffer);
1617 if ((r = uncompress_buffer(ssh, state->incoming_packet,
1618 state->compression_buffer)) != 0)
1620 sshbuf_reset(state->incoming_packet);
1621 if ((r = sshbuf_putb(state->incoming_packet,
1622 state->compression_buffer)) != 0)
1624 DBG(debug("input: len after de-compress %zd",
1625 sshbuf_len(state->incoming_packet)));
1628 * get packet type, implies consume.
1629 * return length of payload (without type field)
1631 if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1633 if (ssh_packet_log_type(*typep))
1634 debug3("receive packet: type %u", *typep);
1635 if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1636 if ((r = sshpkt_disconnect(ssh,
1637 "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1638 (r = ssh_packet_write_wait(ssh)) != 0)
1640 return SSH_ERR_PROTOCOL_ERROR;
1642 if (state->hook_in != NULL &&
1643 (r = state->hook_in(ssh, state->incoming_packet, typep,
1644 state->hook_in_ctx)) != 0)
1646 if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1647 r = ssh_packet_enable_delayed_compress(ssh);
1651 fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1652 sshbuf_dump(state->incoming_packet, stderr);
1654 /* reset for next packet */
1657 /* do we need to rekey? */
1658 if (ssh_packet_need_rekeying(ssh, 0)) {
1659 debug3("%s: rekex triggered", __func__);
1660 if ((r = kex_start_rekex(ssh)) != 0)
1668 ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1670 struct session_state *state = ssh->state;
1671 u_int reason, seqnr;
1677 r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1681 state->keep_alive_timeouts = 0;
1682 DBG(debug("received packet type %d", *typep));
1685 case SSH2_MSG_IGNORE:
1686 debug3("Received SSH2_MSG_IGNORE");
1688 case SSH2_MSG_DEBUG:
1689 if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1690 (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1691 (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1695 debug("Remote: %.900s", msg);
1698 case SSH2_MSG_DISCONNECT:
1699 if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1700 (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1702 /* Ignore normal client exit notifications */
1703 do_log2(ssh->state->server_side &&
1704 reason == SSH2_DISCONNECT_BY_APPLICATION ?
1705 SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1706 "Received disconnect from %s port %d:"
1707 "%u: %.400s", ssh_remote_ipaddr(ssh),
1708 ssh_remote_port(ssh), reason, msg);
1710 return SSH_ERR_DISCONNECTED;
1711 case SSH2_MSG_UNIMPLEMENTED:
1712 if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1714 debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1724 * Buffers the given amount of input characters. This is intended to be used
1725 * together with packet_read_poll.
1729 ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1731 struct session_state *state = ssh->state;
1734 if (state->packet_discard) {
1735 state->keep_alive_timeouts = 0; /* ?? */
1736 if (len >= state->packet_discard) {
1737 if ((r = ssh_packet_stop_discard(ssh)) != 0)
1740 state->packet_discard -= len;
1743 if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1750 ssh_packet_remaining(struct ssh *ssh)
1752 return sshbuf_len(ssh->state->incoming_packet);
1756 * Sends a diagnostic message from the server to the client. This message
1757 * can be sent at any time (but not while constructing another message). The
1758 * message is printed immediately, but only if the client is being executed
1759 * in verbose mode. These messages are primarily intended to ease debugging
1760 * authentication problems. The length of the formatted message must not
1761 * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
1764 ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
1770 if ((ssh->compat & SSH_BUG_DEBUG))
1773 va_start(args, fmt);
1774 vsnprintf(buf, sizeof(buf), fmt, args);
1777 if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
1778 (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
1779 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
1780 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
1781 (r = sshpkt_send(ssh)) != 0 ||
1782 (r = ssh_packet_write_wait(ssh)) != 0)
1783 fatal("%s: %s", __func__, ssh_err(r));
1787 fmt_connection_id(struct ssh *ssh, char *s, size_t l)
1789 snprintf(s, l, "%.200s%s%s port %d",
1790 ssh->log_preamble ? ssh->log_preamble : "",
1791 ssh->log_preamble ? " " : "",
1792 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
1796 * Pretty-print connection-terminating errors and exit.
1799 sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
1801 char remote_id[512];
1803 fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1806 case SSH_ERR_CONN_CLOSED:
1807 ssh_packet_clear_keys(ssh);
1808 logdie("Connection closed by %s", remote_id);
1809 case SSH_ERR_CONN_TIMEOUT:
1810 ssh_packet_clear_keys(ssh);
1811 logdie("Connection %s %s timed out",
1812 ssh->state->server_side ? "from" : "to", remote_id);
1813 case SSH_ERR_DISCONNECTED:
1814 ssh_packet_clear_keys(ssh);
1815 logdie("Disconnected from %s", remote_id);
1816 case SSH_ERR_SYSTEM_ERROR:
1817 if (errno == ECONNRESET) {
1818 ssh_packet_clear_keys(ssh);
1819 logdie("Connection reset by %s", remote_id);
1822 case SSH_ERR_NO_CIPHER_ALG_MATCH:
1823 case SSH_ERR_NO_MAC_ALG_MATCH:
1824 case SSH_ERR_NO_COMPRESS_ALG_MATCH:
1825 case SSH_ERR_NO_KEX_ALG_MATCH:
1826 case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
1827 if (ssh && ssh->kex && ssh->kex->failed_choice) {
1828 ssh_packet_clear_keys(ssh);
1829 logdie("Unable to negotiate with %s: %s. "
1830 "Their offer: %s", remote_id, ssh_err(r),
1831 ssh->kex->failed_choice);
1835 ssh_packet_clear_keys(ssh);
1836 logdie("%s%sConnection %s %s: %s",
1837 tag != NULL ? tag : "", tag != NULL ? ": " : "",
1838 ssh->state->server_side ? "from" : "to",
1839 remote_id, ssh_err(r));
1844 * Logs the error plus constructs and sends a disconnect packet, closes the
1845 * connection, and exits. This function never returns. The error message
1846 * should not contain a newline. The length of the formatted message must
1847 * not exceed 1024 bytes.
1850 ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
1852 char buf[1024], remote_id[512];
1854 static int disconnecting = 0;
1857 if (disconnecting) /* Guard against recursive invocations. */
1858 fatal("packet_disconnect called recursively.");
1862 * Format the message. Note that the caller must make sure the
1863 * message is of limited size.
1865 fmt_connection_id(ssh, remote_id, sizeof(remote_id));
1866 va_start(args, fmt);
1867 vsnprintf(buf, sizeof(buf), fmt, args);
1870 /* Display the error locally */
1871 logit("Disconnecting %s: %.100s", remote_id, buf);
1874 * Send the disconnect message to the other side, and wait
1875 * for it to get sent.
1877 if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
1878 sshpkt_fatal(ssh, __func__, r);
1880 if ((r = ssh_packet_write_wait(ssh)) != 0)
1881 sshpkt_fatal(ssh, __func__, r);
1883 /* Close the connection. */
1884 ssh_packet_close(ssh);
1889 * Checks if there is any buffered output, and tries to write some of
1893 ssh_packet_write_poll(struct ssh *ssh)
1895 struct session_state *state = ssh->state;
1896 int len = sshbuf_len(state->output);
1900 len = write(state->connection_out,
1901 sshbuf_ptr(state->output), len);
1903 if (errno == EINTR || errno == EAGAIN ||
1904 errno == EWOULDBLOCK)
1906 return SSH_ERR_SYSTEM_ERROR;
1909 return SSH_ERR_CONN_CLOSED;
1910 if ((r = sshbuf_consume(state->output, len)) != 0)
1917 * Calls packet_write_poll repeatedly until all pending output data has been
1921 ssh_packet_write_wait(struct ssh *ssh)
1924 int ret, r, ms_remain = 0;
1925 struct timeval start, timeout, *timeoutp = NULL;
1926 struct session_state *state = ssh->state;
1928 setp = calloc(howmany(state->connection_out + 1,
1929 NFDBITS), sizeof(fd_mask));
1931 return SSH_ERR_ALLOC_FAIL;
1932 if ((r = ssh_packet_write_poll(ssh)) != 0) {
1936 while (ssh_packet_have_data_to_write(ssh)) {
1937 memset(setp, 0, howmany(state->connection_out + 1,
1938 NFDBITS) * sizeof(fd_mask));
1939 FD_SET(state->connection_out, setp);
1941 if (state->packet_timeout_ms > 0) {
1942 ms_remain = state->packet_timeout_ms;
1943 timeoutp = &timeout;
1946 if (state->packet_timeout_ms != -1) {
1947 ms_to_timeval(&timeout, ms_remain);
1948 gettimeofday(&start, NULL);
1950 if ((ret = select(state->connection_out + 1,
1951 NULL, setp, NULL, timeoutp)) >= 0)
1953 if (errno != EAGAIN && errno != EINTR &&
1954 errno != EWOULDBLOCK)
1956 if (state->packet_timeout_ms == -1)
1958 ms_subtract_diff(&start, &ms_remain);
1959 if (ms_remain <= 0) {
1966 return SSH_ERR_CONN_TIMEOUT;
1968 if ((r = ssh_packet_write_poll(ssh)) != 0) {
1977 /* Returns true if there is buffered data to write to the connection. */
1980 ssh_packet_have_data_to_write(struct ssh *ssh)
1982 return sshbuf_len(ssh->state->output) != 0;
1985 /* Returns true if there is not too much data to write to the connection. */
1988 ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
1990 if (ssh->state->interactive_mode)
1991 return sshbuf_len(ssh->state->output) < 16384;
1993 return sshbuf_len(ssh->state->output) < 128 * 1024;
1997 ssh_packet_set_tos(struct ssh *ssh, int tos)
1999 #ifndef IP_TOS_IS_BROKEN
2000 if (!ssh_packet_connection_is_on_socket(ssh) || tos == INT_MAX)
2002 switch (ssh_packet_connection_af(ssh)) {
2005 debug3("%s: set IP_TOS 0x%02x", __func__, tos);
2006 if (setsockopt(ssh->state->connection_in,
2007 IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2008 error("setsockopt IP_TOS %d: %.100s:",
2009 tos, strerror(errno));
2011 # endif /* IP_TOS */
2014 debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
2015 if (setsockopt(ssh->state->connection_in,
2016 IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2017 error("setsockopt IPV6_TCLASS %d: %.100s:",
2018 tos, strerror(errno));
2020 # endif /* IPV6_TCLASS */
2022 #endif /* IP_TOS_IS_BROKEN */
2025 /* Informs that the current session is interactive. Sets IP flags for that. */
2028 ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
2030 struct session_state *state = ssh->state;
2032 if (state->set_interactive_called)
2034 state->set_interactive_called = 1;
2036 /* Record that we are in interactive mode. */
2037 state->interactive_mode = interactive;
2039 /* Only set socket options if using a socket. */
2040 if (!ssh_packet_connection_is_on_socket(ssh))
2042 set_nodelay(state->connection_in);
2043 ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2047 /* Returns true if the current connection is interactive. */
2050 ssh_packet_is_interactive(struct ssh *ssh)
2052 return ssh->state->interactive_mode;
2056 ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
2058 struct session_state *state = ssh->state;
2060 if (state->set_maxsize_called) {
2061 logit("packet_set_maxsize: called twice: old %d new %d",
2062 state->max_packet_size, s);
2065 if (s < 4 * 1024 || s > 1024 * 1024) {
2066 logit("packet_set_maxsize: bad size %d", s);
2069 state->set_maxsize_called = 1;
2070 debug("packet_set_maxsize: setting to %d", s);
2071 state->max_packet_size = s;
2076 ssh_packet_inc_alive_timeouts(struct ssh *ssh)
2078 return ++ssh->state->keep_alive_timeouts;
2082 ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
2084 ssh->state->keep_alive_timeouts = ka;
2088 ssh_packet_get_maxsize(struct ssh *ssh)
2090 return ssh->state->max_packet_size;
2094 ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, u_int32_t seconds)
2096 debug3("rekey after %llu bytes, %u seconds", (unsigned long long)bytes,
2097 (unsigned int)seconds);
2098 ssh->state->rekey_limit = bytes;
2099 ssh->state->rekey_interval = seconds;
2103 ssh_packet_get_rekey_timeout(struct ssh *ssh)
2107 seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
2109 return (seconds <= 0 ? 1 : seconds);
2113 ssh_packet_set_server(struct ssh *ssh)
2115 ssh->state->server_side = 1;
2119 ssh_packet_set_authenticated(struct ssh *ssh)
2121 ssh->state->after_authentication = 1;
2125 ssh_packet_get_input(struct ssh *ssh)
2127 return (void *)ssh->state->input;
2131 ssh_packet_get_output(struct ssh *ssh)
2133 return (void *)ssh->state->output;
2136 /* Reset after_authentication and reset compression in post-auth privsep */
2138 ssh_packet_set_postauth(struct ssh *ssh)
2142 debug("%s: called", __func__);
2143 /* This was set in net child, but is not visible in user child */
2144 ssh->state->after_authentication = 1;
2145 ssh->state->rekeying = 0;
2146 if ((r = ssh_packet_enable_delayed_compress(ssh)) != 0)
2151 /* Packet state (de-)serialization for privsep */
2153 /* turn kex into a blob for packet state serialization */
2155 kex_to_blob(struct sshbuf *m, struct kex *kex)
2159 if ((r = sshbuf_put_string(m, kex->session_id,
2160 kex->session_id_len)) != 0 ||
2161 (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2162 (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2163 (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2164 (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2165 (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2166 (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2167 (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2168 (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2173 /* turn key exchange results into a blob for packet state serialization */
2175 newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2178 struct sshcipher_ctx *cc;
2179 struct sshcomp *comp;
2182 struct newkeys *newkey;
2185 if ((newkey = ssh->state->newkeys[mode]) == NULL)
2186 return SSH_ERR_INTERNAL_ERROR;
2189 comp = &newkey->comp;
2190 cc = (mode == MODE_OUT) ? ssh->state->send_context :
2191 ssh->state->receive_context;
2192 if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2194 if ((b = sshbuf_new()) == NULL)
2195 return SSH_ERR_ALLOC_FAIL;
2196 if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2197 (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2198 (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2199 (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2200 (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2202 if (cipher_authlen(enc->cipher) == 0) {
2203 if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2204 (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2205 (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2208 if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2209 (r = sshbuf_put_cstring(b, comp->name)) != 0)
2211 r = sshbuf_put_stringb(m, b);
2217 /* serialize packet state into a blob */
2219 ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2221 struct session_state *state = ssh->state;
2224 if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2225 (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2226 (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2227 (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2228 (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2229 (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2230 (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2231 (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2232 (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2233 (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2234 (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2235 (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2236 (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0 ||
2237 (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2238 (r = sshbuf_put_stringb(m, state->output)) != 0)
2244 /* restore key exchange results from blob for packet state de-serialization */
2246 newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2248 struct sshbuf *b = NULL;
2249 struct sshcomp *comp;
2252 struct newkeys *newkey = NULL;
2253 size_t keylen, ivlen, maclen;
2256 if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2257 r = SSH_ERR_ALLOC_FAIL;
2260 if ((r = sshbuf_froms(m, &b)) != 0)
2263 sshbuf_dump(b, stderr);
2267 comp = &newkey->comp;
2269 if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2270 (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2271 (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2272 (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2273 (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2275 if ((enc->cipher = cipher_by_name(enc->name)) == NULL) {
2276 r = SSH_ERR_INVALID_FORMAT;
2279 if (cipher_authlen(enc->cipher) == 0) {
2280 if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2282 if ((r = mac_setup(mac, mac->name)) != 0)
2284 if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2285 (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2287 if (maclen > mac->key_len) {
2288 r = SSH_ERR_INVALID_FORMAT;
2291 mac->key_len = maclen;
2293 if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2294 (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2296 if (sshbuf_len(b) != 0) {
2297 r = SSH_ERR_INVALID_FORMAT;
2300 enc->key_len = keylen;
2301 enc->iv_len = ivlen;
2302 ssh->kex->newkeys[mode] = newkey;
2311 /* restore kex from blob for packet state de-serialization */
2313 kex_from_blob(struct sshbuf *m, struct kex **kexp)
2318 if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2319 (kex->my = sshbuf_new()) == NULL ||
2320 (kex->peer = sshbuf_new()) == NULL) {
2321 r = SSH_ERR_ALLOC_FAIL;
2324 if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2325 (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2326 (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2327 (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2328 (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2329 (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2330 (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2331 (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2332 (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2338 if (r != 0 || kexp == NULL) {
2340 sshbuf_free(kex->my);
2341 sshbuf_free(kex->peer);
2353 * Restore packet state from content of blob 'm' (de-serialization).
2354 * Note that 'm' will be partially consumed on parsing or any other errors.
2357 ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2359 struct session_state *state = ssh->state;
2360 const u_char *input, *output;
2364 if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2365 (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2366 (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2367 (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2368 (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2369 (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2370 (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2371 (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2372 (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2373 (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2374 (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2375 (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2376 (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2379 * We set the time here so that in post-auth privsep slave we
2380 * count from the completion of the authentication.
2382 state->rekey_time = monotime();
2383 /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2384 if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2385 (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2388 if ((r = ssh_packet_set_postauth(ssh)) != 0)
2391 sshbuf_reset(state->input);
2392 sshbuf_reset(state->output);
2393 if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2394 (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2395 (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2396 (r = sshbuf_put(state->output, output, olen)) != 0)
2400 return SSH_ERR_INVALID_FORMAT;
2401 debug3("%s: done", __func__);
2407 /* put data to the outgoing packet */
2410 sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2412 return sshbuf_put(ssh->state->outgoing_packet, v, len);
2416 sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2418 return sshbuf_putb(ssh->state->outgoing_packet, b);
2422 sshpkt_put_u8(struct ssh *ssh, u_char val)
2424 return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2428 sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2430 return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2434 sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2436 return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2440 sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2442 return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2446 sshpkt_put_cstring(struct ssh *ssh, const void *v)
2448 return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2452 sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2454 return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2458 #ifdef OPENSSL_HAS_ECC
2460 sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2462 return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2464 #endif /* OPENSSL_HAS_ECC */
2468 sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2470 return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2472 #endif /* WITH_OPENSSL */
2474 /* fetch data from the incoming packet */
2477 sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2479 return sshbuf_get(ssh->state->incoming_packet, valp, len);
2483 sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2485 return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2489 sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2491 return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2495 sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2497 return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2501 sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2503 return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2507 sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2509 return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2513 sshpkt_peek_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2515 return sshbuf_peek_string_direct(ssh->state->incoming_packet, valp, lenp);
2519 sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2521 return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2525 #ifdef OPENSSL_HAS_ECC
2527 sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2529 return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2531 #endif /* OPENSSL_HAS_ECC */
2535 sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2537 return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2539 #endif /* WITH_OPENSSL */
2542 sshpkt_get_end(struct ssh *ssh)
2544 if (sshbuf_len(ssh->state->incoming_packet) > 0)
2545 return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2550 sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2553 *lenp = sshbuf_len(ssh->state->incoming_packet);
2554 return sshbuf_ptr(ssh->state->incoming_packet);
2557 /* start a new packet */
2560 sshpkt_start(struct ssh *ssh, u_char type)
2562 u_char buf[6]; /* u32 packet length, u8 pad len, u8 type */
2564 DBG(debug("packet_start[%d]", type));
2565 memset(buf, 0, sizeof(buf));
2566 buf[sizeof(buf) - 1] = type;
2567 sshbuf_reset(ssh->state->outgoing_packet);
2568 return sshbuf_put(ssh->state->outgoing_packet, buf, sizeof(buf));
2572 ssh_packet_send_mux(struct ssh *ssh)
2574 struct session_state *state = ssh->state;
2580 return SSH_ERR_INTERNAL_ERROR;
2581 len = sshbuf_len(state->outgoing_packet);
2583 return SSH_ERR_INTERNAL_ERROR;
2584 cp = sshbuf_mutable_ptr(state->outgoing_packet);
2586 if (ssh_packet_log_type(type))
2587 debug3("%s: type %u", __func__, type);
2588 /* drop everything, but the connection protocol */
2589 if (type >= SSH2_MSG_CONNECTION_MIN &&
2590 type <= SSH2_MSG_CONNECTION_MAX) {
2591 POKE_U32(cp, len - 4);
2592 if ((r = sshbuf_putb(state->output,
2593 state->outgoing_packet)) != 0)
2595 /* sshbuf_dump(state->output, stderr); */
2597 sshbuf_reset(state->outgoing_packet);
2602 * 9.2. Ignored Data Message
2604 * byte SSH_MSG_IGNORE
2607 * All implementations MUST understand (and ignore) this message at any
2608 * time (after receiving the protocol version). No implementation is
2609 * required to send them. This message can be used as an additional
2610 * protection measure against advanced traffic analysis techniques.
2613 sshpkt_msg_ignore(struct ssh *ssh, u_int nbytes)
2619 if ((r = sshpkt_start(ssh, SSH2_MSG_IGNORE)) != 0 ||
2620 (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2622 for (i = 0; i < nbytes; i++) {
2625 if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2635 sshpkt_send(struct ssh *ssh)
2637 if (ssh->state && ssh->state->mux)
2638 return ssh_packet_send_mux(ssh);
2639 return ssh_packet_send2(ssh);
2643 sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2649 va_start(args, fmt);
2650 vsnprintf(buf, sizeof(buf), fmt, args);
2653 if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2654 (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2655 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2656 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2657 (r = sshpkt_send(ssh)) != 0)
2662 /* roundup current message to pad bytes */
2664 sshpkt_add_padding(struct ssh *ssh, u_char pad)
2666 ssh->state->extra_pad = pad;