1 /* $OpenBSD: packet.c,v 1.234 2016/07/18 11:35:33 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.
43 #include <sys/param.h> /* MIN roundup */
44 #include <sys/types.h>
45 #include "openbsd-compat/sys-queue.h"
46 #include <sys/socket.h>
47 #ifdef HAVE_SYS_TIME_H
48 # include <sys/time.h>
51 #include <netinet/in.h>
52 #include <netinet/ip.h>
53 #include <arpa/inet.h>
68 #include "buffer.h" /* typedefs XXX */
69 #include "key.h" /* typedefs XXX */
97 #define PACKET_MAX_SIZE (256 * 1024)
107 TAILQ_ENTRY(packet) next;
109 struct sshbuf *payload;
112 struct session_state {
114 * This variable contains the file descriptors used for
115 * communicating with the other side. connection_in is used for
116 * reading; connection_out for writing. These can be the same
117 * descriptor, in which case it is assumed to be a socket.
122 /* Protocol flags for the remote side. */
123 u_int remote_protocol_flags;
125 /* Encryption context for receiving data. Only used for decryption. */
126 struct sshcipher_ctx receive_context;
128 /* Encryption context for sending data. Only used for encryption. */
129 struct sshcipher_ctx send_context;
131 /* Buffer for raw input data from the socket. */
132 struct sshbuf *input;
134 /* Buffer for raw output data going to the socket. */
135 struct sshbuf *output;
137 /* Buffer for the partial outgoing packet being constructed. */
138 struct sshbuf *outgoing_packet;
140 /* Buffer for the incoming packet currently being processed. */
141 struct sshbuf *incoming_packet;
143 /* Scratch buffer for packet compression/decompression. */
144 struct sshbuf *compression_buffer;
146 /* Incoming/outgoing compression dictionaries */
147 z_stream compression_in_stream;
148 z_stream compression_out_stream;
149 int compression_in_started;
150 int compression_out_started;
151 int compression_in_failures;
152 int compression_out_failures;
155 * Flag indicating whether packet compression/decompression is
158 int packet_compression;
160 /* default maximum packet size */
161 u_int max_packet_size;
163 /* Flag indicating whether this module has been initialized. */
166 /* Set to true if the connection is interactive. */
167 int interactive_mode;
169 /* Set to true if we are the server side. */
172 /* Set to true if we are authenticated. */
173 int after_authentication;
175 int keep_alive_timeouts;
177 /* The maximum time that we will wait to send or receive a packet */
178 int packet_timeout_ms;
180 /* Session key information for Encryption and MAC */
181 struct newkeys *newkeys[MODE_MAX];
182 struct packet_state p_read, p_send;
184 /* Volume-based rekeying */
185 u_int64_t max_blocks_in, max_blocks_out, 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 size_t packet_discard_mac_already;
201 struct sshmac *packet_discard_mac;
203 /* Used in packet_read_poll2() */
206 /* Used in packet_send2 */
209 /* Used in packet_set_interactive */
210 int set_interactive_called;
212 /* Used in packet_set_maxsize */
213 int set_maxsize_called;
215 /* One-off warning about weak ciphers */
216 int cipher_warning_done;
218 /* SSH1 CRC compensation attack detector */
219 struct deattack_ctx deattack;
221 TAILQ_HEAD(, packet) outgoing;
225 ssh_alloc_session_state(void)
227 struct ssh *ssh = NULL;
228 struct session_state *state = NULL;
230 if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
231 (state = calloc(1, sizeof(*state))) == NULL ||
232 (state->input = sshbuf_new()) == NULL ||
233 (state->output = sshbuf_new()) == NULL ||
234 (state->outgoing_packet = sshbuf_new()) == NULL ||
235 (state->incoming_packet = sshbuf_new()) == NULL)
237 TAILQ_INIT(&state->outgoing);
238 TAILQ_INIT(&ssh->private_keys);
239 TAILQ_INIT(&ssh->public_keys);
240 state->connection_in = -1;
241 state->connection_out = -1;
242 state->max_packet_size = 32768;
243 state->packet_timeout_ms = -1;
244 state->p_send.packets = state->p_read.packets = 0;
245 state->initialized = 1;
247 * ssh_packet_send2() needs to queue packets until
248 * we've done the initial key exchange.
255 sshbuf_free(state->input);
256 sshbuf_free(state->output);
257 sshbuf_free(state->incoming_packet);
258 sshbuf_free(state->outgoing_packet);
265 /* Returns nonzero if rekeying is in progress */
267 ssh_packet_is_rekeying(struct ssh *ssh)
270 (ssh->state->rekeying || (ssh->kex != NULL && ssh->kex->done == 0));
274 * Sets the descriptors used for communication. Disables encryption until
275 * packet_set_encryption_key is called.
278 ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
280 struct session_state *state;
281 const struct sshcipher *none = cipher_by_name("none");
285 error("%s: cannot load cipher 'none'", __func__);
289 ssh = ssh_alloc_session_state();
291 error("%s: cound not allocate state", __func__);
295 state->connection_in = fd_in;
296 state->connection_out = fd_out;
297 if ((r = cipher_init(&state->send_context, none,
298 (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
299 (r = cipher_init(&state->receive_context, none,
300 (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
301 error("%s: cipher_init failed: %s", __func__, ssh_err(r));
302 free(ssh); /* XXX need ssh_free_session_state? */
305 state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
306 deattack_init(&state->deattack);
308 * Cache the IP address of the remote connection for use in error
309 * messages that might be generated after the connection has closed.
311 (void)ssh_remote_ipaddr(ssh);
316 ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
318 struct session_state *state = ssh->state;
320 if (timeout <= 0 || count <= 0) {
321 state->packet_timeout_ms = -1;
324 if ((INT_MAX / 1000) / count < timeout)
325 state->packet_timeout_ms = INT_MAX;
327 state->packet_timeout_ms = timeout * count * 1000;
331 ssh_packet_stop_discard(struct ssh *ssh)
333 struct session_state *state = ssh->state;
336 if (state->packet_discard_mac) {
338 size_t dlen = PACKET_MAX_SIZE;
340 if (dlen > state->packet_discard_mac_already)
341 dlen -= state->packet_discard_mac_already;
342 memset(buf, 'a', sizeof(buf));
343 while (sshbuf_len(state->incoming_packet) < dlen)
344 if ((r = sshbuf_put(state->incoming_packet, buf,
347 (void) mac_compute(state->packet_discard_mac,
349 sshbuf_ptr(state->incoming_packet), dlen,
352 logit("Finished discarding for %.200s port %d",
353 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
354 return SSH_ERR_MAC_INVALID;
358 ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
359 struct sshmac *mac, size_t mac_already, u_int discard)
361 struct session_state *state = ssh->state;
364 if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
365 if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
367 return SSH_ERR_MAC_INVALID;
370 * Record number of bytes over which the mac has already
371 * been computed in order to minimize timing attacks.
373 if (mac && mac->enabled) {
374 state->packet_discard_mac = mac;
375 state->packet_discard_mac_already = mac_already;
377 if (sshbuf_len(state->input) >= discard)
378 return ssh_packet_stop_discard(ssh);
379 state->packet_discard = discard - sshbuf_len(state->input);
383 /* Returns 1 if remote host is connected via socket, 0 if not. */
386 ssh_packet_connection_is_on_socket(struct ssh *ssh)
388 struct session_state *state = ssh->state;
389 struct sockaddr_storage from, to;
390 socklen_t fromlen, tolen;
392 if (state->connection_in == -1 || state->connection_out == -1)
395 /* filedescriptors in and out are the same, so it's a socket */
396 if (state->connection_in == state->connection_out)
398 fromlen = sizeof(from);
399 memset(&from, 0, sizeof(from));
400 if (getpeername(state->connection_in, (struct sockaddr *)&from,
404 memset(&to, 0, sizeof(to));
405 if (getpeername(state->connection_out, (struct sockaddr *)&to,
408 if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
410 if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
416 ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
419 *ibytes = ssh->state->p_read.bytes;
421 *obytes = ssh->state->p_send.bytes;
425 ssh_packet_connection_af(struct ssh *ssh)
427 struct sockaddr_storage to;
428 socklen_t tolen = sizeof(to);
430 memset(&to, 0, sizeof(to));
431 if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
435 if (to.ss_family == AF_INET6 &&
436 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr))
442 /* Sets the connection into non-blocking mode. */
445 ssh_packet_set_nonblocking(struct ssh *ssh)
447 /* Set the socket into non-blocking mode. */
448 set_nonblock(ssh->state->connection_in);
450 if (ssh->state->connection_out != ssh->state->connection_in)
451 set_nonblock(ssh->state->connection_out);
454 /* Returns the socket used for reading. */
457 ssh_packet_get_connection_in(struct ssh *ssh)
459 return ssh->state->connection_in;
462 /* Returns the descriptor used for writing. */
465 ssh_packet_get_connection_out(struct ssh *ssh)
467 return ssh->state->connection_out;
471 * Returns the IP-address of the remote host as a string. The returned
472 * string must not be freed.
476 ssh_remote_ipaddr(struct ssh *ssh)
478 const int sock = ssh->state->connection_in;
480 /* Check whether we have cached the ipaddr. */
481 if (ssh->remote_ipaddr == NULL) {
482 if (ssh_packet_connection_is_on_socket(ssh)) {
483 ssh->remote_ipaddr = get_peer_ipaddr(sock);
484 ssh->remote_port = get_peer_port(sock);
485 ssh->local_ipaddr = get_local_ipaddr(sock);
486 ssh->local_port = get_local_port(sock);
488 ssh->remote_ipaddr = strdup("UNKNOWN");
489 ssh->remote_port = 65535;
490 ssh->local_ipaddr = strdup("UNKNOWN");
491 ssh->local_port = 65535;
494 return ssh->remote_ipaddr;
497 /* Returns the port number of the remote host. */
500 ssh_remote_port(struct ssh *ssh)
502 (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
503 return ssh->remote_port;
507 * Returns the IP-address of the local host as a string. The returned
508 * string must not be freed.
512 ssh_local_ipaddr(struct ssh *ssh)
514 (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
515 return ssh->local_ipaddr;
518 /* Returns the port number of the local host. */
521 ssh_local_port(struct ssh *ssh)
523 (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
524 return ssh->local_port;
527 /* Closes the connection and clears and frees internal data structures. */
530 ssh_packet_close(struct ssh *ssh)
532 struct session_state *state = ssh->state;
536 if (!state->initialized)
538 state->initialized = 0;
539 if (state->connection_in == state->connection_out) {
540 shutdown(state->connection_out, SHUT_RDWR);
541 close(state->connection_out);
543 close(state->connection_in);
544 close(state->connection_out);
546 sshbuf_free(state->input);
547 sshbuf_free(state->output);
548 sshbuf_free(state->outgoing_packet);
549 sshbuf_free(state->incoming_packet);
550 for (mode = 0; mode < MODE_MAX; mode++)
551 kex_free_newkeys(state->newkeys[mode]);
552 if (state->compression_buffer) {
553 sshbuf_free(state->compression_buffer);
554 if (state->compression_out_started) {
555 z_streamp stream = &state->compression_out_stream;
556 debug("compress outgoing: "
557 "raw data %llu, compressed %llu, factor %.2f",
558 (unsigned long long)stream->total_in,
559 (unsigned long long)stream->total_out,
560 stream->total_in == 0 ? 0.0 :
561 (double) stream->total_out / stream->total_in);
562 if (state->compression_out_failures == 0)
565 if (state->compression_in_started) {
566 z_streamp stream = &state->compression_out_stream;
567 debug("compress incoming: "
568 "raw data %llu, compressed %llu, factor %.2f",
569 (unsigned long long)stream->total_out,
570 (unsigned long long)stream->total_in,
571 stream->total_out == 0 ? 0.0 :
572 (double) stream->total_in / stream->total_out);
573 if (state->compression_in_failures == 0)
577 if ((r = cipher_cleanup(&state->send_context)) != 0)
578 error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
579 if ((r = cipher_cleanup(&state->receive_context)) != 0)
580 error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
581 free(ssh->remote_ipaddr);
582 ssh->remote_ipaddr = NULL;
587 /* Sets remote side protocol flags. */
590 ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
592 ssh->state->remote_protocol_flags = protocol_flags;
595 /* Returns the remote protocol flags set earlier by the above function. */
598 ssh_packet_get_protocol_flags(struct ssh *ssh)
600 return ssh->state->remote_protocol_flags;
604 * Starts packet compression from the next packet on in both directions.
605 * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
609 ssh_packet_init_compression(struct ssh *ssh)
611 if (!ssh->state->compression_buffer &&
612 ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
613 return SSH_ERR_ALLOC_FAIL;
618 start_compression_out(struct ssh *ssh, int level)
620 if (level < 1 || level > 9)
621 return SSH_ERR_INVALID_ARGUMENT;
622 debug("Enabling compression at level %d.", level);
623 if (ssh->state->compression_out_started == 1)
624 deflateEnd(&ssh->state->compression_out_stream);
625 switch (deflateInit(&ssh->state->compression_out_stream, level)) {
627 ssh->state->compression_out_started = 1;
630 return SSH_ERR_ALLOC_FAIL;
632 return SSH_ERR_INTERNAL_ERROR;
638 start_compression_in(struct ssh *ssh)
640 if (ssh->state->compression_in_started == 1)
641 inflateEnd(&ssh->state->compression_in_stream);
642 switch (inflateInit(&ssh->state->compression_in_stream)) {
644 ssh->state->compression_in_started = 1;
647 return SSH_ERR_ALLOC_FAIL;
649 return SSH_ERR_INTERNAL_ERROR;
655 ssh_packet_start_compression(struct ssh *ssh, int level)
659 if (ssh->state->packet_compression && !compat20)
660 return SSH_ERR_INTERNAL_ERROR;
661 ssh->state->packet_compression = 1;
662 if ((r = ssh_packet_init_compression(ssh)) != 0 ||
663 (r = start_compression_in(ssh)) != 0 ||
664 (r = start_compression_out(ssh, level)) != 0)
669 /* XXX remove need for separate compression buffer */
671 compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
676 if (ssh->state->compression_out_started != 1)
677 return SSH_ERR_INTERNAL_ERROR;
679 /* This case is not handled below. */
680 if (sshbuf_len(in) == 0)
683 /* Input is the contents of the input buffer. */
684 if ((ssh->state->compression_out_stream.next_in =
685 sshbuf_mutable_ptr(in)) == NULL)
686 return SSH_ERR_INTERNAL_ERROR;
687 ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
689 /* Loop compressing until deflate() returns with avail_out != 0. */
691 /* Set up fixed-size output buffer. */
692 ssh->state->compression_out_stream.next_out = buf;
693 ssh->state->compression_out_stream.avail_out = sizeof(buf);
695 /* Compress as much data into the buffer as possible. */
696 status = deflate(&ssh->state->compression_out_stream,
700 return SSH_ERR_ALLOC_FAIL;
702 /* Append compressed data to output_buffer. */
703 if ((r = sshbuf_put(out, buf, sizeof(buf) -
704 ssh->state->compression_out_stream.avail_out)) != 0)
709 ssh->state->compression_out_failures++;
710 return SSH_ERR_INVALID_FORMAT;
712 } while (ssh->state->compression_out_stream.avail_out == 0);
717 uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
722 if (ssh->state->compression_in_started != 1)
723 return SSH_ERR_INTERNAL_ERROR;
725 if ((ssh->state->compression_in_stream.next_in =
726 sshbuf_mutable_ptr(in)) == NULL)
727 return SSH_ERR_INTERNAL_ERROR;
728 ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
731 /* Set up fixed-size output buffer. */
732 ssh->state->compression_in_stream.next_out = buf;
733 ssh->state->compression_in_stream.avail_out = sizeof(buf);
735 status = inflate(&ssh->state->compression_in_stream,
739 if ((r = sshbuf_put(out, buf, sizeof(buf) -
740 ssh->state->compression_in_stream.avail_out)) != 0)
745 * Comments in zlib.h say that we should keep calling
746 * inflate() until we get an error. This appears to
747 * be the error that we get.
751 return SSH_ERR_INVALID_FORMAT;
753 return SSH_ERR_ALLOC_FAIL;
756 ssh->state->compression_in_failures++;
757 return SSH_ERR_INTERNAL_ERROR;
763 /* Serialise compression state into a blob for privsep */
765 ssh_packet_get_compress_state(struct sshbuf *m, struct ssh *ssh)
767 struct session_state *state = ssh->state;
771 if ((b = sshbuf_new()) == NULL)
772 return SSH_ERR_ALLOC_FAIL;
773 if (state->compression_in_started) {
774 if ((r = sshbuf_put_string(b, &state->compression_in_stream,
775 sizeof(state->compression_in_stream))) != 0)
777 } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
779 if (state->compression_out_started) {
780 if ((r = sshbuf_put_string(b, &state->compression_out_stream,
781 sizeof(state->compression_out_stream))) != 0)
783 } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
785 r = sshbuf_put_stringb(m, b);
791 /* Deserialise compression state from a blob for privsep */
793 ssh_packet_set_compress_state(struct ssh *ssh, struct sshbuf *m)
795 struct session_state *state = ssh->state;
796 struct sshbuf *b = NULL;
798 const u_char *inblob, *outblob;
801 if ((r = sshbuf_froms(m, &b)) != 0)
803 if ((r = sshbuf_get_string_direct(b, &inblob, &inl)) != 0 ||
804 (r = sshbuf_get_string_direct(b, &outblob, &outl)) != 0)
807 state->compression_in_started = 0;
808 else if (inl != sizeof(state->compression_in_stream)) {
809 r = SSH_ERR_INTERNAL_ERROR;
812 state->compression_in_started = 1;
813 memcpy(&state->compression_in_stream, inblob, inl);
816 state->compression_out_started = 0;
817 else if (outl != sizeof(state->compression_out_stream)) {
818 r = SSH_ERR_INTERNAL_ERROR;
821 state->compression_out_started = 1;
822 memcpy(&state->compression_out_stream, outblob, outl);
831 ssh_packet_set_compress_hooks(struct ssh *ssh, void *ctx,
832 void *(*allocfunc)(void *, u_int, u_int),
833 void (*freefunc)(void *, void *))
835 ssh->state->compression_out_stream.zalloc = (alloc_func)allocfunc;
836 ssh->state->compression_out_stream.zfree = (free_func)freefunc;
837 ssh->state->compression_out_stream.opaque = ctx;
838 ssh->state->compression_in_stream.zalloc = (alloc_func)allocfunc;
839 ssh->state->compression_in_stream.zfree = (free_func)freefunc;
840 ssh->state->compression_in_stream.opaque = ctx;
844 * Causes any further packets to be encrypted using the given key. The same
845 * key is used for both sending and reception. However, both directions are
846 * encrypted independently of each other.
850 ssh_packet_set_encryption_key(struct ssh *ssh, const u_char *key, u_int keylen, int number)
853 fatal("no SSH protocol 1 support");
854 #else /* WITH_SSH1 */
855 struct session_state *state = ssh->state;
856 const struct sshcipher *cipher = cipher_by_number(number);
861 fatal("%s: unknown cipher number %d", __func__, number);
863 fatal("%s: keylen too small: %d", __func__, keylen);
864 if (keylen > SSH_SESSION_KEY_LENGTH)
865 fatal("%s: keylen too big: %d", __func__, keylen);
866 memcpy(state->ssh1_key, key, keylen);
867 state->ssh1_keylen = keylen;
868 if ((r = cipher_init(&state->send_context, cipher, key, keylen,
869 NULL, 0, CIPHER_ENCRYPT)) != 0 ||
870 (r = cipher_init(&state->receive_context, cipher, key, keylen,
871 NULL, 0, CIPHER_DECRYPT) != 0))
872 fatal("%s: cipher_init failed: %s", __func__, ssh_err(r));
873 if (!state->cipher_warning_done &&
874 ((wmsg = cipher_warning_message(&state->send_context)) != NULL ||
875 (wmsg = cipher_warning_message(&state->send_context)) != NULL)) {
876 error("Warning: %s", wmsg);
877 state->cipher_warning_done = 1;
879 #endif /* WITH_SSH1 */
883 * Finalizes and sends the packet. If the encryption key has been set,
884 * encrypts the packet before sending.
888 ssh_packet_send1(struct ssh *ssh)
890 struct session_state *state = ssh->state;
896 * If using packet compression, compress the payload of the outgoing
899 if (state->packet_compression) {
900 sshbuf_reset(state->compression_buffer);
902 if ((r = sshbuf_consume(state->outgoing_packet, 8)) != 0)
905 if ((r = sshbuf_put(state->compression_buffer,
906 "\0\0\0\0\0\0\0\0", 8)) != 0)
908 if ((r = compress_buffer(ssh, state->outgoing_packet,
909 state->compression_buffer)) != 0)
911 sshbuf_reset(state->outgoing_packet);
912 if ((r = sshbuf_putb(state->outgoing_packet,
913 state->compression_buffer)) != 0)
916 /* Compute packet length without padding (add checksum, remove padding). */
917 len = sshbuf_len(state->outgoing_packet) + 4 - 8;
919 /* Insert padding. Initialized to zero in packet_start1() */
920 padding = 8 - len % 8;
921 if (!state->send_context.plaintext) {
922 cp = sshbuf_mutable_ptr(state->outgoing_packet);
924 r = SSH_ERR_INTERNAL_ERROR;
927 arc4random_buf(cp + 8 - padding, padding);
929 if ((r = sshbuf_consume(state->outgoing_packet, 8 - padding)) != 0)
932 /* Add check bytes. */
933 checksum = ssh_crc32(sshbuf_ptr(state->outgoing_packet),
934 sshbuf_len(state->outgoing_packet));
935 POKE_U32(buf, checksum);
936 if ((r = sshbuf_put(state->outgoing_packet, buf, 4)) != 0)
940 fprintf(stderr, "packet_send plain: ");
941 sshbuf_dump(state->outgoing_packet, stderr);
944 /* Append to output. */
946 if ((r = sshbuf_put(state->output, buf, 4)) != 0)
948 if ((r = sshbuf_reserve(state->output,
949 sshbuf_len(state->outgoing_packet), &cp)) != 0)
951 if ((r = cipher_crypt(&state->send_context, 0, cp,
952 sshbuf_ptr(state->outgoing_packet),
953 sshbuf_len(state->outgoing_packet), 0, 0)) != 0)
957 fprintf(stderr, "encrypted: ");
958 sshbuf_dump(state->output, stderr);
960 state->p_send.packets++;
961 state->p_send.bytes += len +
962 sshbuf_len(state->outgoing_packet);
963 sshbuf_reset(state->outgoing_packet);
966 * Note that the packet is now only buffered in output. It won't be
967 * actually sent until ssh_packet_write_wait or ssh_packet_write_poll
976 ssh_set_newkeys(struct ssh *ssh, int mode)
978 struct session_state *state = ssh->state;
981 struct sshcomp *comp;
982 struct sshcipher_ctx *cc;
983 u_int64_t *max_blocks;
987 debug2("set_newkeys: mode %d", mode);
989 if (mode == MODE_OUT) {
990 cc = &state->send_context;
991 crypt_type = CIPHER_ENCRYPT;
992 state->p_send.packets = state->p_send.blocks = 0;
993 max_blocks = &state->max_blocks_out;
995 cc = &state->receive_context;
996 crypt_type = CIPHER_DECRYPT;
997 state->p_read.packets = state->p_read.blocks = 0;
998 max_blocks = &state->max_blocks_in;
1000 if (state->newkeys[mode] != NULL) {
1001 debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
1002 "output %llu bytes %llu blocks",
1003 (unsigned long long)state->p_read.bytes,
1004 (unsigned long long)state->p_read.blocks,
1005 (unsigned long long)state->p_send.bytes,
1006 (unsigned long long)state->p_send.blocks);
1007 if ((r = cipher_cleanup(cc)) != 0)
1009 enc = &state->newkeys[mode]->enc;
1010 mac = &state->newkeys[mode]->mac;
1011 comp = &state->newkeys[mode]->comp;
1013 explicit_bzero(enc->iv, enc->iv_len);
1014 explicit_bzero(enc->key, enc->key_len);
1015 explicit_bzero(mac->key, mac->key_len);
1022 free(state->newkeys[mode]);
1024 /* move newkeys from kex to state */
1025 if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
1026 return SSH_ERR_INTERNAL_ERROR;
1027 ssh->kex->newkeys[mode] = NULL;
1028 enc = &state->newkeys[mode]->enc;
1029 mac = &state->newkeys[mode]->mac;
1030 comp = &state->newkeys[mode]->comp;
1031 if (cipher_authlen(enc->cipher) == 0) {
1032 if ((r = mac_init(mac)) != 0)
1036 DBG(debug("cipher_init_context: %d", mode));
1037 if ((r = cipher_init(cc, enc->cipher, enc->key, enc->key_len,
1038 enc->iv, enc->iv_len, crypt_type)) != 0)
1040 if (!state->cipher_warning_done &&
1041 (wmsg = cipher_warning_message(cc)) != NULL) {
1042 error("Warning: %s", wmsg);
1043 state->cipher_warning_done = 1;
1045 /* Deleting the keys does not gain extra security */
1046 /* explicit_bzero(enc->iv, enc->block_size);
1047 explicit_bzero(enc->key, enc->key_len);
1048 explicit_bzero(mac->key, mac->key_len); */
1049 if ((comp->type == COMP_ZLIB ||
1050 (comp->type == COMP_DELAYED &&
1051 state->after_authentication)) && comp->enabled == 0) {
1052 if ((r = ssh_packet_init_compression(ssh)) < 0)
1054 if (mode == MODE_OUT) {
1055 if ((r = start_compression_out(ssh, 6)) != 0)
1058 if ((r = start_compression_in(ssh)) != 0)
1064 * The 2^(blocksize*2) limit is too expensive for 3DES,
1065 * blowfish, etc, so enforce a 1GB limit for small blocksizes.
1067 if (enc->block_size >= 16)
1068 *max_blocks = (u_int64_t)1 << (enc->block_size*2);
1070 *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1071 if (state->rekey_limit)
1072 *max_blocks = MIN(*max_blocks,
1073 state->rekey_limit / enc->block_size);
1074 debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1078 #define MAX_PACKETS (1U<<31)
1080 ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
1082 struct session_state *state = ssh->state;
1083 u_int32_t out_blocks;
1085 /* XXX client can't cope with rekeying pre-auth */
1086 if (!state->after_authentication)
1089 /* Haven't keyed yet or KEX in progress. */
1090 if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
1093 /* Peer can't rekey */
1094 if (ssh->compat & SSH_BUG_NOREKEY)
1098 * Permit one packet in or out per rekey - this allows us to
1099 * make progress when rekey limits are very small.
1101 if (state->p_send.packets == 0 && state->p_read.packets == 0)
1104 /* Time-based rekeying */
1105 if (state->rekey_interval != 0 &&
1106 state->rekey_time + state->rekey_interval <= monotime())
1109 /* Always rekey when MAX_PACKETS sent in either direction */
1110 if (state->p_send.packets > MAX_PACKETS ||
1111 state->p_read.packets > MAX_PACKETS)
1114 /* Rekey after (cipher-specific) maxiumum blocks */
1115 out_blocks = roundup(outbound_packet_len,
1116 state->newkeys[MODE_OUT]->enc.block_size);
1117 return (state->max_blocks_out &&
1118 (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
1119 (state->max_blocks_in &&
1120 (state->p_read.blocks > state->max_blocks_in));
1124 * Delayed compression for SSH2 is enabled after authentication:
1125 * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1126 * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
1129 ssh_packet_enable_delayed_compress(struct ssh *ssh)
1131 struct session_state *state = ssh->state;
1132 struct sshcomp *comp = NULL;
1136 * Remember that we are past the authentication step, so rekeying
1137 * with COMP_DELAYED will turn on compression immediately.
1139 state->after_authentication = 1;
1140 for (mode = 0; mode < MODE_MAX; mode++) {
1141 /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1142 if (state->newkeys[mode] == NULL)
1144 comp = &state->newkeys[mode]->comp;
1145 if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1146 if ((r = ssh_packet_init_compression(ssh)) != 0)
1148 if (mode == MODE_OUT) {
1149 if ((r = start_compression_out(ssh, 6)) != 0)
1152 if ((r = start_compression_in(ssh)) != 0)
1161 /* Used to mute debug logging for noisy packet types */
1163 ssh_packet_log_type(u_char type)
1166 case SSH2_MSG_CHANNEL_DATA:
1167 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1168 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1176 * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1179 ssh_packet_send2_wrapped(struct ssh *ssh)
1181 struct session_state *state = ssh->state;
1182 u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1183 u_char tmp, padlen, pad = 0;
1184 u_int authlen = 0, aadlen = 0;
1186 struct sshenc *enc = NULL;
1187 struct sshmac *mac = NULL;
1188 struct sshcomp *comp = NULL;
1191 if (state->newkeys[MODE_OUT] != NULL) {
1192 enc = &state->newkeys[MODE_OUT]->enc;
1193 mac = &state->newkeys[MODE_OUT]->mac;
1194 comp = &state->newkeys[MODE_OUT]->comp;
1195 /* disable mac for authenticated encryption */
1196 if ((authlen = cipher_authlen(enc->cipher)) != 0)
1199 block_size = enc ? enc->block_size : 8;
1200 aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1202 type = (sshbuf_ptr(state->outgoing_packet))[5];
1203 if (ssh_packet_log_type(type))
1204 debug3("send packet: type %u", type);
1206 fprintf(stderr, "plain: ");
1207 sshbuf_dump(state->outgoing_packet, stderr);
1210 if (comp && comp->enabled) {
1211 len = sshbuf_len(state->outgoing_packet);
1212 /* skip header, compress only payload */
1213 if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1215 sshbuf_reset(state->compression_buffer);
1216 if ((r = compress_buffer(ssh, state->outgoing_packet,
1217 state->compression_buffer)) != 0)
1219 sshbuf_reset(state->outgoing_packet);
1220 if ((r = sshbuf_put(state->outgoing_packet,
1221 "\0\0\0\0\0", 5)) != 0 ||
1222 (r = sshbuf_putb(state->outgoing_packet,
1223 state->compression_buffer)) != 0)
1225 DBG(debug("compression: raw %d compressed %zd", len,
1226 sshbuf_len(state->outgoing_packet)));
1229 /* sizeof (packet_len + pad_len + payload) */
1230 len = sshbuf_len(state->outgoing_packet);
1233 * calc size of padding, alloc space, get random data,
1234 * minimum padding is 4 bytes
1236 len -= aadlen; /* packet length is not encrypted for EtM modes */
1237 padlen = block_size - (len % block_size);
1239 padlen += block_size;
1240 if (state->extra_pad) {
1241 tmp = state->extra_pad;
1243 roundup(state->extra_pad, block_size);
1244 /* check if roundup overflowed */
1245 if (state->extra_pad < tmp)
1246 return SSH_ERR_INVALID_ARGUMENT;
1247 tmp = (len + padlen) % state->extra_pad;
1248 /* Check whether pad calculation below will underflow */
1249 if (tmp > state->extra_pad)
1250 return SSH_ERR_INVALID_ARGUMENT;
1251 pad = state->extra_pad - tmp;
1252 DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1253 __func__, pad, len, padlen, state->extra_pad));
1256 /* Check whether padlen calculation overflowed */
1258 return SSH_ERR_INVALID_ARGUMENT; /* overflow */
1259 state->extra_pad = 0;
1261 if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1263 if (enc && !state->send_context.plaintext) {
1264 /* random padding */
1265 arc4random_buf(cp, padlen);
1268 explicit_bzero(cp, padlen);
1270 /* sizeof (packet_len + pad_len + payload + padding) */
1271 len = sshbuf_len(state->outgoing_packet);
1272 cp = sshbuf_mutable_ptr(state->outgoing_packet);
1274 r = SSH_ERR_INTERNAL_ERROR;
1277 /* packet_length includes payload, padding and padding length field */
1278 POKE_U32(cp, len - 4);
1280 DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1281 len, padlen, aadlen));
1283 /* compute MAC over seqnr and packet(length fields, payload, padding) */
1284 if (mac && mac->enabled && !mac->etm) {
1285 if ((r = mac_compute(mac, state->p_send.seqnr,
1286 sshbuf_ptr(state->outgoing_packet), len,
1287 macbuf, sizeof(macbuf))) != 0)
1289 DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1291 /* encrypt packet and append to output buffer. */
1292 if ((r = sshbuf_reserve(state->output,
1293 sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1295 if ((r = cipher_crypt(&state->send_context, state->p_send.seqnr, cp,
1296 sshbuf_ptr(state->outgoing_packet),
1297 len - aadlen, aadlen, authlen)) != 0)
1299 /* append unencrypted MAC */
1300 if (mac && mac->enabled) {
1302 /* EtM: compute mac over aadlen + cipher text */
1303 if ((r = mac_compute(mac, state->p_send.seqnr,
1304 cp, len, macbuf, sizeof(macbuf))) != 0)
1306 DBG(debug("done calc MAC(EtM) out #%d",
1307 state->p_send.seqnr));
1309 if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1313 fprintf(stderr, "encrypted: ");
1314 sshbuf_dump(state->output, stderr);
1316 /* increment sequence number for outgoing packets */
1317 if (++state->p_send.seqnr == 0)
1318 logit("outgoing seqnr wraps around");
1319 if (++state->p_send.packets == 0)
1320 if (!(ssh->compat & SSH_BUG_NOREKEY))
1321 return SSH_ERR_NEED_REKEY;
1322 state->p_send.blocks += len / block_size;
1323 state->p_send.bytes += len;
1324 sshbuf_reset(state->outgoing_packet);
1326 if (type == SSH2_MSG_NEWKEYS)
1327 r = ssh_set_newkeys(ssh, MODE_OUT);
1328 else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1329 r = ssh_packet_enable_delayed_compress(ssh);
1336 /* returns non-zero if the specified packet type is usec by KEX */
1338 ssh_packet_type_is_kex(u_char type)
1341 type >= SSH2_MSG_TRANSPORT_MIN &&
1342 type <= SSH2_MSG_TRANSPORT_MAX &&
1343 type != SSH2_MSG_SERVICE_REQUEST &&
1344 type != SSH2_MSG_SERVICE_ACCEPT &&
1345 type != SSH2_MSG_EXT_INFO;
1349 ssh_packet_send2(struct ssh *ssh)
1351 struct session_state *state = ssh->state;
1356 if (sshbuf_len(state->outgoing_packet) < 6)
1357 return SSH_ERR_INTERNAL_ERROR;
1358 type = sshbuf_ptr(state->outgoing_packet)[5];
1359 need_rekey = !ssh_packet_type_is_kex(type) &&
1360 ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1363 * During rekeying we can only send key exchange messages.
1364 * Queue everything else.
1366 if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1368 debug3("%s: rekex triggered", __func__);
1369 debug("enqueue packet: %u", type);
1370 p = calloc(1, sizeof(*p));
1372 return SSH_ERR_ALLOC_FAIL;
1374 p->payload = state->outgoing_packet;
1375 TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1376 state->outgoing_packet = sshbuf_new();
1377 if (state->outgoing_packet == NULL)
1378 return SSH_ERR_ALLOC_FAIL;
1381 * This packet triggered a rekey, so send the
1383 * NB. reenters this function via kex_start_rekex().
1385 return kex_start_rekex(ssh);
1390 /* rekeying starts with sending KEXINIT */
1391 if (type == SSH2_MSG_KEXINIT)
1392 state->rekeying = 1;
1394 if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1397 /* after a NEWKEYS message we can send the complete queue */
1398 if (type == SSH2_MSG_NEWKEYS) {
1399 state->rekeying = 0;
1400 state->rekey_time = monotime();
1401 while ((p = TAILQ_FIRST(&state->outgoing))) {
1404 * If this packet triggers a rekex, then skip the
1405 * remaining packets in the queue for now.
1406 * NB. re-enters this function via kex_start_rekex.
1408 if (ssh_packet_need_rekeying(ssh,
1409 sshbuf_len(p->payload))) {
1410 debug3("%s: queued packet triggered rekex",
1412 return kex_start_rekex(ssh);
1414 debug("dequeue packet: %u", type);
1415 sshbuf_free(state->outgoing_packet);
1416 state->outgoing_packet = p->payload;
1417 TAILQ_REMOVE(&state->outgoing, p, next);
1418 memset(p, 0, sizeof(*p));
1420 if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1428 * Waits until a packet has been received, and returns its type. Note that
1429 * no other data is processed until this returns, so this function should not
1430 * be used during the interactive session.
1434 ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1436 struct session_state *state = ssh->state;
1437 int len, r, ms_remain;
1440 struct timeval timeout, start, *timeoutp = NULL;
1442 DBG(debug("packet_read()"));
1444 setp = calloc(howmany(state->connection_in + 1,
1445 NFDBITS), sizeof(fd_mask));
1447 return SSH_ERR_ALLOC_FAIL;
1450 * Since we are blocking, ensure that all written packets have
1453 if ((r = ssh_packet_write_wait(ssh)) != 0)
1456 /* Stay in the loop until we have received a complete packet. */
1458 /* Try to read a packet from the buffer. */
1459 r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1463 *typep == SSH_SMSG_SUCCESS
1464 || *typep == SSH_SMSG_FAILURE
1465 || *typep == SSH_CMSG_EOF
1466 || *typep == SSH_CMSG_EXIT_CONFIRMATION))
1467 if ((r = sshpkt_get_end(ssh)) != 0)
1469 /* If we got a packet, return it. */
1470 if (*typep != SSH_MSG_NONE)
1473 * Otherwise, wait for some data to arrive, add it to the
1474 * buffer, and try again.
1476 memset(setp, 0, howmany(state->connection_in + 1,
1477 NFDBITS) * sizeof(fd_mask));
1478 FD_SET(state->connection_in, setp);
1480 if (state->packet_timeout_ms > 0) {
1481 ms_remain = state->packet_timeout_ms;
1482 timeoutp = &timeout;
1484 /* Wait for some data to arrive. */
1486 if (state->packet_timeout_ms != -1) {
1487 ms_to_timeval(&timeout, ms_remain);
1488 gettimeofday(&start, NULL);
1490 if ((r = select(state->connection_in + 1, setp,
1491 NULL, NULL, timeoutp)) >= 0)
1493 if (errno != EAGAIN && errno != EINTR &&
1494 errno != EWOULDBLOCK)
1496 if (state->packet_timeout_ms == -1)
1498 ms_subtract_diff(&start, &ms_remain);
1499 if (ms_remain <= 0) {
1505 return SSH_ERR_CONN_TIMEOUT;
1506 /* Read data from the socket. */
1507 len = read(state->connection_in, buf, sizeof(buf));
1509 r = SSH_ERR_CONN_CLOSED;
1513 r = SSH_ERR_SYSTEM_ERROR;
1517 /* Append it to the buffer. */
1518 if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1527 ssh_packet_read(struct ssh *ssh)
1532 if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1533 fatal("%s: %s", __func__, ssh_err(r));
1538 * Waits until a packet has been received, verifies that its type matches
1539 * that given, and gives a fatal error and exits if there is a mismatch.
1543 ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1548 if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1550 if (type != expected_type) {
1551 if ((r = sshpkt_disconnect(ssh,
1552 "Protocol error: expected packet type %d, got %d",
1553 expected_type, type)) != 0)
1555 return SSH_ERR_PROTOCOL_ERROR;
1560 /* Checks if a full packet is available in the data received so far via
1561 * packet_process_incoming. If so, reads the packet; otherwise returns
1562 * SSH_MSG_NONE. This does not wait for data from the connection.
1564 * SSH_MSG_DISCONNECT is handled specially here. Also,
1565 * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1570 ssh_packet_read_poll1(struct ssh *ssh, u_char *typep)
1572 struct session_state *state = ssh->state;
1573 u_int len, padded_len;
1577 u_int checksum, stored_checksum;
1580 *typep = SSH_MSG_NONE;
1582 /* Check if input size is less than minimum packet size. */
1583 if (sshbuf_len(state->input) < 4 + 8)
1585 /* Get length of incoming packet. */
1586 len = PEEK_U32(sshbuf_ptr(state->input));
1587 if (len < 1 + 2 + 2 || len > 256 * 1024) {
1588 if ((r = sshpkt_disconnect(ssh, "Bad packet length %u",
1591 return SSH_ERR_CONN_CORRUPT;
1593 padded_len = (len + 8) & ~7;
1595 /* Check if the packet has been entirely received. */
1596 if (sshbuf_len(state->input) < 4 + padded_len)
1599 /* The entire packet is in buffer. */
1601 /* Consume packet length. */
1602 if ((r = sshbuf_consume(state->input, 4)) != 0)
1606 * Cryptographic attack detector for ssh
1607 * (C)1998 CORE-SDI, Buenos Aires Argentina
1608 * Ariel Futoransky(futo@core-sdi.com)
1610 if (!state->receive_context.plaintext) {
1612 switch (detect_attack(&state->deattack,
1613 sshbuf_ptr(state->input), padded_len)) {
1616 case DEATTACK_DETECTED:
1617 emsg = "crc32 compensation attack detected";
1619 case DEATTACK_DOS_DETECTED:
1620 emsg = "deattack denial of service detected";
1623 emsg = "deattack error";
1628 if ((r = sshpkt_disconnect(ssh, "%s", emsg)) != 0 ||
1629 (r = ssh_packet_write_wait(ssh)) != 0)
1631 return SSH_ERR_CONN_CORRUPT;
1635 /* Decrypt data to incoming_packet. */
1636 sshbuf_reset(state->incoming_packet);
1637 if ((r = sshbuf_reserve(state->incoming_packet, padded_len, &p)) != 0)
1639 if ((r = cipher_crypt(&state->receive_context, 0, p,
1640 sshbuf_ptr(state->input), padded_len, 0, 0)) != 0)
1643 if ((r = sshbuf_consume(state->input, padded_len)) != 0)
1647 fprintf(stderr, "read_poll plain: ");
1648 sshbuf_dump(state->incoming_packet, stderr);
1651 /* Compute packet checksum. */
1652 checksum = ssh_crc32(sshbuf_ptr(state->incoming_packet),
1653 sshbuf_len(state->incoming_packet) - 4);
1656 if ((r = sshbuf_consume(state->incoming_packet, 8 - len % 8)) != 0)
1659 /* Test check bytes. */
1660 if (len != sshbuf_len(state->incoming_packet)) {
1661 error("%s: len %d != sshbuf_len %zd", __func__,
1662 len, sshbuf_len(state->incoming_packet));
1663 if ((r = sshpkt_disconnect(ssh, "invalid packet length")) != 0 ||
1664 (r = ssh_packet_write_wait(ssh)) != 0)
1666 return SSH_ERR_CONN_CORRUPT;
1669 cp = sshbuf_ptr(state->incoming_packet) + len - 4;
1670 stored_checksum = PEEK_U32(cp);
1671 if (checksum != stored_checksum) {
1672 error("Corrupted check bytes on input");
1673 if ((r = sshpkt_disconnect(ssh, "connection corrupted")) != 0 ||
1674 (r = ssh_packet_write_wait(ssh)) != 0)
1676 return SSH_ERR_CONN_CORRUPT;
1678 if ((r = sshbuf_consume_end(state->incoming_packet, 4)) < 0)
1681 if (state->packet_compression) {
1682 sshbuf_reset(state->compression_buffer);
1683 if ((r = uncompress_buffer(ssh, state->incoming_packet,
1684 state->compression_buffer)) != 0)
1686 sshbuf_reset(state->incoming_packet);
1687 if ((r = sshbuf_putb(state->incoming_packet,
1688 state->compression_buffer)) != 0)
1691 state->p_read.packets++;
1692 state->p_read.bytes += padded_len + 4;
1693 if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1695 if (*typep < SSH_MSG_MIN || *typep > SSH_MSG_MAX) {
1696 error("Invalid ssh1 packet type: %d", *typep);
1697 if ((r = sshpkt_disconnect(ssh, "invalid packet type")) != 0 ||
1698 (r = ssh_packet_write_wait(ssh)) != 0)
1700 return SSH_ERR_PROTOCOL_ERROR;
1708 ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1710 struct session_state *state = ssh->state;
1713 u_int maclen, aadlen = 0, authlen = 0, block_size;
1714 struct sshenc *enc = NULL;
1715 struct sshmac *mac = NULL;
1716 struct sshcomp *comp = NULL;
1719 *typep = SSH_MSG_NONE;
1721 if (state->packet_discard)
1724 if (state->newkeys[MODE_IN] != NULL) {
1725 enc = &state->newkeys[MODE_IN]->enc;
1726 mac = &state->newkeys[MODE_IN]->mac;
1727 comp = &state->newkeys[MODE_IN]->comp;
1728 /* disable mac for authenticated encryption */
1729 if ((authlen = cipher_authlen(enc->cipher)) != 0)
1732 maclen = mac && mac->enabled ? mac->mac_len : 0;
1733 block_size = enc ? enc->block_size : 8;
1734 aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1736 if (aadlen && state->packlen == 0) {
1737 if (cipher_get_length(&state->receive_context,
1738 &state->packlen, state->p_read.seqnr,
1739 sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1741 if (state->packlen < 1 + 4 ||
1742 state->packlen > PACKET_MAX_SIZE) {
1744 sshbuf_dump(state->input, stderr);
1746 logit("Bad packet length %u.", state->packlen);
1747 if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1749 return SSH_ERR_CONN_CORRUPT;
1751 sshbuf_reset(state->incoming_packet);
1752 } else if (state->packlen == 0) {
1754 * check if input size is less than the cipher block size,
1755 * decrypt first block and extract length of incoming packet
1757 if (sshbuf_len(state->input) < block_size)
1759 sshbuf_reset(state->incoming_packet);
1760 if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1763 if ((r = cipher_crypt(&state->receive_context,
1764 state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1765 block_size, 0, 0)) != 0)
1767 state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1768 if (state->packlen < 1 + 4 ||
1769 state->packlen > PACKET_MAX_SIZE) {
1771 fprintf(stderr, "input: \n");
1772 sshbuf_dump(state->input, stderr);
1773 fprintf(stderr, "incoming_packet: \n");
1774 sshbuf_dump(state->incoming_packet, stderr);
1776 logit("Bad packet length %u.", state->packlen);
1777 return ssh_packet_start_discard(ssh, enc, mac, 0,
1780 if ((r = sshbuf_consume(state->input, block_size)) != 0)
1783 DBG(debug("input: packet len %u", state->packlen+4));
1786 /* only the payload is encrypted */
1787 need = state->packlen;
1790 * the payload size and the payload are encrypted, but we
1791 * have a partial packet of block_size bytes
1793 need = 4 + state->packlen - block_size;
1795 DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1796 " aadlen %d", block_size, need, maclen, authlen, aadlen));
1797 if (need % block_size != 0) {
1798 logit("padding error: need %d block %d mod %d",
1799 need, block_size, need % block_size);
1800 return ssh_packet_start_discard(ssh, enc, mac, 0,
1801 PACKET_MAX_SIZE - block_size);
1804 * check if the entire packet has been received and
1805 * decrypt into incoming_packet:
1806 * 'aadlen' bytes are unencrypted, but authenticated.
1807 * 'need' bytes are encrypted, followed by either
1808 * 'authlen' bytes of authentication tag or
1809 * 'maclen' bytes of message authentication code.
1811 if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1812 return 0; /* packet is incomplete */
1814 fprintf(stderr, "read_poll enc/full: ");
1815 sshbuf_dump(state->input, stderr);
1817 /* EtM: check mac over encrypted input */
1818 if (mac && mac->enabled && mac->etm) {
1819 if ((r = mac_check(mac, state->p_read.seqnr,
1820 sshbuf_ptr(state->input), aadlen + need,
1821 sshbuf_ptr(state->input) + aadlen + need + authlen,
1823 if (r == SSH_ERR_MAC_INVALID)
1824 logit("Corrupted MAC on input.");
1828 if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1831 if ((r = cipher_crypt(&state->receive_context, state->p_read.seqnr, cp,
1832 sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1834 if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1836 if (mac && mac->enabled) {
1837 /* Not EtM: check MAC over cleartext */
1838 if (!mac->etm && (r = mac_check(mac, state->p_read.seqnr,
1839 sshbuf_ptr(state->incoming_packet),
1840 sshbuf_len(state->incoming_packet),
1841 sshbuf_ptr(state->input), maclen)) != 0) {
1842 if (r != SSH_ERR_MAC_INVALID)
1844 logit("Corrupted MAC on input.");
1845 if (need > PACKET_MAX_SIZE)
1846 return SSH_ERR_INTERNAL_ERROR;
1847 return ssh_packet_start_discard(ssh, enc, mac,
1848 sshbuf_len(state->incoming_packet),
1849 PACKET_MAX_SIZE - need);
1851 /* Remove MAC from input buffer */
1852 DBG(debug("MAC #%d ok", state->p_read.seqnr));
1853 if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1856 if (seqnr_p != NULL)
1857 *seqnr_p = state->p_read.seqnr;
1858 if (++state->p_read.seqnr == 0)
1859 logit("incoming seqnr wraps around");
1860 if (++state->p_read.packets == 0)
1861 if (!(ssh->compat & SSH_BUG_NOREKEY))
1862 return SSH_ERR_NEED_REKEY;
1863 state->p_read.blocks += (state->packlen + 4) / block_size;
1864 state->p_read.bytes += state->packlen + 4;
1867 padlen = sshbuf_ptr(state->incoming_packet)[4];
1868 DBG(debug("input: padlen %d", padlen));
1870 if ((r = sshpkt_disconnect(ssh,
1871 "Corrupted padlen %d on input.", padlen)) != 0 ||
1872 (r = ssh_packet_write_wait(ssh)) != 0)
1874 return SSH_ERR_CONN_CORRUPT;
1877 /* skip packet size + padlen, discard padding */
1878 if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1879 ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1882 DBG(debug("input: len before de-compress %zd",
1883 sshbuf_len(state->incoming_packet)));
1884 if (comp && comp->enabled) {
1885 sshbuf_reset(state->compression_buffer);
1886 if ((r = uncompress_buffer(ssh, state->incoming_packet,
1887 state->compression_buffer)) != 0)
1889 sshbuf_reset(state->incoming_packet);
1890 if ((r = sshbuf_putb(state->incoming_packet,
1891 state->compression_buffer)) != 0)
1893 DBG(debug("input: len after de-compress %zd",
1894 sshbuf_len(state->incoming_packet)));
1897 * get packet type, implies consume.
1898 * return length of payload (without type field)
1900 if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1902 if (ssh_packet_log_type(*typep))
1903 debug3("receive packet: type %u", *typep);
1904 if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1905 if ((r = sshpkt_disconnect(ssh,
1906 "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1907 (r = ssh_packet_write_wait(ssh)) != 0)
1909 return SSH_ERR_PROTOCOL_ERROR;
1911 if (*typep == SSH2_MSG_NEWKEYS)
1912 r = ssh_set_newkeys(ssh, MODE_IN);
1913 else if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1914 r = ssh_packet_enable_delayed_compress(ssh);
1918 fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1919 sshbuf_dump(state->incoming_packet, stderr);
1921 /* reset for next packet */
1924 /* do we need to rekey? */
1925 if (ssh_packet_need_rekeying(ssh, 0)) {
1926 debug3("%s: rekex triggered", __func__);
1927 if ((r = kex_start_rekex(ssh)) != 0)
1935 ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1937 struct session_state *state = ssh->state;
1938 u_int reason, seqnr;
1945 r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1949 state->keep_alive_timeouts = 0;
1950 DBG(debug("received packet type %d", *typep));
1953 case SSH2_MSG_IGNORE:
1954 debug3("Received SSH2_MSG_IGNORE");
1956 case SSH2_MSG_DEBUG:
1957 if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1958 (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1959 (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1963 debug("Remote: %.900s", msg);
1966 case SSH2_MSG_DISCONNECT:
1967 if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1968 (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1970 /* Ignore normal client exit notifications */
1971 do_log2(ssh->state->server_side &&
1972 reason == SSH2_DISCONNECT_BY_APPLICATION ?
1973 SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1974 "Received disconnect from %s port %d:"
1975 "%u: %.400s", ssh_remote_ipaddr(ssh),
1976 ssh_remote_port(ssh), reason, msg);
1978 return SSH_ERR_DISCONNECTED;
1979 case SSH2_MSG_UNIMPLEMENTED:
1980 if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1982 debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1989 r = ssh_packet_read_poll1(ssh, typep);
1992 return SSH_MSG_NONE;
1993 case SSH_MSG_IGNORE:
1996 if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1998 debug("Remote: %.900s", msg);
2001 case SSH_MSG_DISCONNECT:
2002 if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
2004 logit("Received disconnect from %s port %d: "
2005 "%.400s", ssh_remote_ipaddr(ssh),
2006 ssh_remote_port(ssh), msg);
2008 return SSH_ERR_DISCONNECTED;
2010 DBG(debug("received packet type %d", *typep));
2018 * Buffers the given amount of input characters. This is intended to be used
2019 * together with packet_read_poll.
2023 ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
2025 struct session_state *state = ssh->state;
2028 if (state->packet_discard) {
2029 state->keep_alive_timeouts = 0; /* ?? */
2030 if (len >= state->packet_discard) {
2031 if ((r = ssh_packet_stop_discard(ssh)) != 0)
2034 state->packet_discard -= len;
2037 if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
2044 ssh_packet_remaining(struct ssh *ssh)
2046 return sshbuf_len(ssh->state->incoming_packet);
2050 * Sends a diagnostic message from the server to the client. This message
2051 * can be sent at any time (but not while constructing another message). The
2052 * message is printed immediately, but only if the client is being executed
2053 * in verbose mode. These messages are primarily intended to ease debugging
2054 * authentication problems. The length of the formatted message must not
2055 * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
2058 ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
2064 if (compat20 && (ssh->compat & SSH_BUG_DEBUG))
2067 va_start(args, fmt);
2068 vsnprintf(buf, sizeof(buf), fmt, args);
2072 if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
2073 (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
2074 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2075 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2076 (r = sshpkt_send(ssh)) != 0)
2077 fatal("%s: %s", __func__, ssh_err(r));
2079 if ((r = sshpkt_start(ssh, SSH_MSG_DEBUG)) != 0 ||
2080 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2081 (r = sshpkt_send(ssh)) != 0)
2082 fatal("%s: %s", __func__, ssh_err(r));
2084 if ((r = ssh_packet_write_wait(ssh)) != 0)
2085 fatal("%s: %s", __func__, ssh_err(r));
2089 * Pretty-print connection-terminating errors and exit.
2092 sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
2095 case SSH_ERR_CONN_CLOSED:
2096 logdie("Connection closed by %.200s port %d",
2097 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
2098 case SSH_ERR_CONN_TIMEOUT:
2099 logdie("Connection %s %.200s port %d timed out",
2100 ssh->state->server_side ? "from" : "to",
2101 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
2102 case SSH_ERR_DISCONNECTED:
2103 logdie("Disconnected from %.200s port %d",
2104 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
2105 case SSH_ERR_SYSTEM_ERROR:
2106 if (errno == ECONNRESET)
2107 logdie("Connection reset by %.200s port %d",
2108 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
2110 case SSH_ERR_NO_CIPHER_ALG_MATCH:
2111 case SSH_ERR_NO_MAC_ALG_MATCH:
2112 case SSH_ERR_NO_COMPRESS_ALG_MATCH:
2113 case SSH_ERR_NO_KEX_ALG_MATCH:
2114 case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
2115 if (ssh && ssh->kex && ssh->kex->failed_choice) {
2116 logdie("Unable to negotiate with %.200s port %d: %s. "
2117 "Their offer: %s", ssh_remote_ipaddr(ssh),
2118 ssh_remote_port(ssh), ssh_err(r),
2119 ssh->kex->failed_choice);
2123 logdie("%s%sConnection %s %.200s port %d: %s",
2124 tag != NULL ? tag : "", tag != NULL ? ": " : "",
2125 ssh->state->server_side ? "from" : "to",
2126 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), ssh_err(r));
2131 * Logs the error plus constructs and sends a disconnect packet, closes the
2132 * connection, and exits. This function never returns. The error message
2133 * should not contain a newline. The length of the formatted message must
2134 * not exceed 1024 bytes.
2137 ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
2141 static int disconnecting = 0;
2144 if (disconnecting) /* Guard against recursive invocations. */
2145 fatal("packet_disconnect called recursively.");
2149 * Format the message. Note that the caller must make sure the
2150 * message is of limited size.
2152 va_start(args, fmt);
2153 vsnprintf(buf, sizeof(buf), fmt, args);
2156 /* Display the error locally */
2157 logit("Disconnecting: %.100s", buf);
2160 * Send the disconnect message to the other side, and wait
2161 * for it to get sent.
2163 if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
2164 sshpkt_fatal(ssh, __func__, r);
2166 if ((r = ssh_packet_write_wait(ssh)) != 0)
2167 sshpkt_fatal(ssh, __func__, r);
2169 /* Close the connection. */
2170 ssh_packet_close(ssh);
2175 * Checks if there is any buffered output, and tries to write some of
2179 ssh_packet_write_poll(struct ssh *ssh)
2181 struct session_state *state = ssh->state;
2182 int len = sshbuf_len(state->output);
2186 len = write(state->connection_out,
2187 sshbuf_ptr(state->output), len);
2189 if (errno == EINTR || errno == EAGAIN ||
2190 errno == EWOULDBLOCK)
2192 return SSH_ERR_SYSTEM_ERROR;
2195 return SSH_ERR_CONN_CLOSED;
2196 if ((r = sshbuf_consume(state->output, len)) != 0)
2203 * Calls packet_write_poll repeatedly until all pending output data has been
2207 ssh_packet_write_wait(struct ssh *ssh)
2210 int ret, r, ms_remain = 0;
2211 struct timeval start, timeout, *timeoutp = NULL;
2212 struct session_state *state = ssh->state;
2214 setp = calloc(howmany(state->connection_out + 1,
2215 NFDBITS), sizeof(fd_mask));
2217 return SSH_ERR_ALLOC_FAIL;
2218 if ((r = ssh_packet_write_poll(ssh)) != 0) {
2222 while (ssh_packet_have_data_to_write(ssh)) {
2223 memset(setp, 0, howmany(state->connection_out + 1,
2224 NFDBITS) * sizeof(fd_mask));
2225 FD_SET(state->connection_out, setp);
2227 if (state->packet_timeout_ms > 0) {
2228 ms_remain = state->packet_timeout_ms;
2229 timeoutp = &timeout;
2232 if (state->packet_timeout_ms != -1) {
2233 ms_to_timeval(&timeout, ms_remain);
2234 gettimeofday(&start, NULL);
2236 if ((ret = select(state->connection_out + 1,
2237 NULL, setp, NULL, timeoutp)) >= 0)
2239 if (errno != EAGAIN && errno != EINTR &&
2240 errno != EWOULDBLOCK)
2242 if (state->packet_timeout_ms == -1)
2244 ms_subtract_diff(&start, &ms_remain);
2245 if (ms_remain <= 0) {
2252 return SSH_ERR_CONN_TIMEOUT;
2254 if ((r = ssh_packet_write_poll(ssh)) != 0) {
2263 /* Returns true if there is buffered data to write to the connection. */
2266 ssh_packet_have_data_to_write(struct ssh *ssh)
2268 return sshbuf_len(ssh->state->output) != 0;
2271 /* Returns true if there is not too much data to write to the connection. */
2274 ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
2276 if (ssh->state->interactive_mode)
2277 return sshbuf_len(ssh->state->output) < 16384;
2279 return sshbuf_len(ssh->state->output) < 128 * 1024;
2283 ssh_packet_set_tos(struct ssh *ssh, int tos)
2285 #ifndef IP_TOS_IS_BROKEN
2286 if (!ssh_packet_connection_is_on_socket(ssh))
2288 switch (ssh_packet_connection_af(ssh)) {
2291 debug3("%s: set IP_TOS 0x%02x", __func__, tos);
2292 if (setsockopt(ssh->state->connection_in,
2293 IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2294 error("setsockopt IP_TOS %d: %.100s:",
2295 tos, strerror(errno));
2297 # endif /* IP_TOS */
2300 debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
2301 if (setsockopt(ssh->state->connection_in,
2302 IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2303 error("setsockopt IPV6_TCLASS %d: %.100s:",
2304 tos, strerror(errno));
2306 # endif /* IPV6_TCLASS */
2308 #endif /* IP_TOS_IS_BROKEN */
2311 /* Informs that the current session is interactive. Sets IP flags for that. */
2314 ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
2316 struct session_state *state = ssh->state;
2318 if (state->set_interactive_called)
2320 state->set_interactive_called = 1;
2322 /* Record that we are in interactive mode. */
2323 state->interactive_mode = interactive;
2325 /* Only set socket options if using a socket. */
2326 if (!ssh_packet_connection_is_on_socket(ssh))
2328 set_nodelay(state->connection_in);
2329 ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2333 /* Returns true if the current connection is interactive. */
2336 ssh_packet_is_interactive(struct ssh *ssh)
2338 return ssh->state->interactive_mode;
2342 ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
2344 struct session_state *state = ssh->state;
2346 if (state->set_maxsize_called) {
2347 logit("packet_set_maxsize: called twice: old %d new %d",
2348 state->max_packet_size, s);
2351 if (s < 4 * 1024 || s > 1024 * 1024) {
2352 logit("packet_set_maxsize: bad size %d", s);
2355 state->set_maxsize_called = 1;
2356 debug("packet_set_maxsize: setting to %d", s);
2357 state->max_packet_size = s;
2362 ssh_packet_inc_alive_timeouts(struct ssh *ssh)
2364 return ++ssh->state->keep_alive_timeouts;
2368 ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
2370 ssh->state->keep_alive_timeouts = ka;
2374 ssh_packet_get_maxsize(struct ssh *ssh)
2376 return ssh->state->max_packet_size;
2380 * 9.2. Ignored Data Message
2382 * byte SSH_MSG_IGNORE
2385 * All implementations MUST understand (and ignore) this message at any
2386 * time (after receiving the protocol version). No implementation is
2387 * required to send them. This message can be used as an additional
2388 * protection measure against advanced traffic analysis techniques.
2391 ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
2396 if ((r = sshpkt_start(ssh, compat20 ?
2397 SSH2_MSG_IGNORE : SSH_MSG_IGNORE)) != 0 ||
2398 (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2399 fatal("%s: %s", __func__, ssh_err(r));
2400 for (i = 0; i < nbytes; i++) {
2403 if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2404 fatal("%s: %s", __func__, ssh_err(r));
2410 ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, time_t seconds)
2412 debug3("rekey after %llu bytes, %d seconds", (unsigned long long)bytes,
2414 ssh->state->rekey_limit = bytes;
2415 ssh->state->rekey_interval = seconds;
2419 ssh_packet_get_rekey_timeout(struct ssh *ssh)
2423 seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
2425 return (seconds <= 0 ? 1 : seconds);
2429 ssh_packet_set_server(struct ssh *ssh)
2431 ssh->state->server_side = 1;
2435 ssh_packet_set_authenticated(struct ssh *ssh)
2437 ssh->state->after_authentication = 1;
2441 ssh_packet_get_input(struct ssh *ssh)
2443 return (void *)ssh->state->input;
2447 ssh_packet_get_output(struct ssh *ssh)
2449 return (void *)ssh->state->output;
2452 /* Reset after_authentication and reset compression in post-auth privsep */
2454 ssh_packet_set_postauth(struct ssh *ssh)
2456 struct sshcomp *comp;
2459 debug("%s: called", __func__);
2460 /* This was set in net child, but is not visible in user child */
2461 ssh->state->after_authentication = 1;
2462 ssh->state->rekeying = 0;
2463 for (mode = 0; mode < MODE_MAX; mode++) {
2464 if (ssh->state->newkeys[mode] == NULL)
2466 comp = &ssh->state->newkeys[mode]->comp;
2467 if (comp && comp->enabled &&
2468 (r = ssh_packet_init_compression(ssh)) != 0)
2474 /* Packet state (de-)serialization for privsep */
2476 /* turn kex into a blob for packet state serialization */
2478 kex_to_blob(struct sshbuf *m, struct kex *kex)
2482 if ((r = sshbuf_put_string(m, kex->session_id,
2483 kex->session_id_len)) != 0 ||
2484 (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2485 (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2486 (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2487 (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2488 (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2489 (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2490 (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2491 (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2496 /* turn key exchange results into a blob for packet state serialization */
2498 newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2501 struct sshcipher_ctx *cc;
2502 struct sshcomp *comp;
2505 struct newkeys *newkey;
2508 if ((newkey = ssh->state->newkeys[mode]) == NULL)
2509 return SSH_ERR_INTERNAL_ERROR;
2512 comp = &newkey->comp;
2513 cc = (mode == MODE_OUT) ? &ssh->state->send_context :
2514 &ssh->state->receive_context;
2515 if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2517 if ((b = sshbuf_new()) == NULL)
2518 return SSH_ERR_ALLOC_FAIL;
2519 /* The cipher struct is constant and shared, you export pointer */
2520 if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2521 (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2522 (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2523 (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2524 (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2525 (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2527 if (cipher_authlen(enc->cipher) == 0) {
2528 if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2529 (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2530 (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2533 if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2534 (r = sshbuf_put_u32(b, comp->enabled)) != 0 ||
2535 (r = sshbuf_put_cstring(b, comp->name)) != 0)
2537 r = sshbuf_put_stringb(m, b);
2543 /* serialize packet state into a blob */
2545 ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2547 struct session_state *state = ssh->state;
2553 ssh1cipher = cipher_get_number(state->receive_context.cipher);
2554 slen = cipher_get_keyiv_len(&state->send_context);
2555 rlen = cipher_get_keyiv_len(&state->receive_context);
2556 if ((r = sshbuf_put_u32(m, state->remote_protocol_flags)) != 0 ||
2557 (r = sshbuf_put_u32(m, ssh1cipher)) != 0 ||
2558 (r = sshbuf_put_string(m, state->ssh1_key, state->ssh1_keylen)) != 0 ||
2559 (r = sshbuf_put_u32(m, slen)) != 0 ||
2560 (r = sshbuf_reserve(m, slen, &p)) != 0 ||
2561 (r = cipher_get_keyiv(&state->send_context, p, slen)) != 0 ||
2562 (r = sshbuf_put_u32(m, rlen)) != 0 ||
2563 (r = sshbuf_reserve(m, rlen, &p)) != 0 ||
2564 (r = cipher_get_keyiv(&state->receive_context, p, rlen)) != 0)
2567 if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2568 (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2569 (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2570 (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2571 (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2572 (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2573 (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2574 (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2575 (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2576 (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2577 (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2578 (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2579 (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0)
2583 slen = cipher_get_keycontext(&state->send_context, NULL);
2584 rlen = cipher_get_keycontext(&state->receive_context, NULL);
2585 if ((r = sshbuf_put_u32(m, slen)) != 0 ||
2586 (r = sshbuf_reserve(m, slen, &p)) != 0)
2588 if (cipher_get_keycontext(&state->send_context, p) != (int)slen)
2589 return SSH_ERR_INTERNAL_ERROR;
2590 if ((r = sshbuf_put_u32(m, rlen)) != 0 ||
2591 (r = sshbuf_reserve(m, rlen, &p)) != 0)
2593 if (cipher_get_keycontext(&state->receive_context, p) != (int)rlen)
2594 return SSH_ERR_INTERNAL_ERROR;
2596 if ((r = ssh_packet_get_compress_state(m, ssh)) != 0 ||
2597 (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2598 (r = sshbuf_put_stringb(m, state->output)) != 0)
2604 /* restore key exchange results from blob for packet state de-serialization */
2606 newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2608 struct sshbuf *b = NULL;
2609 struct sshcomp *comp;
2612 struct newkeys *newkey = NULL;
2613 size_t keylen, ivlen, maclen;
2616 if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2617 r = SSH_ERR_ALLOC_FAIL;
2620 if ((r = sshbuf_froms(m, &b)) != 0)
2623 sshbuf_dump(b, stderr);
2627 comp = &newkey->comp;
2629 if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2630 (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2631 (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2632 (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2633 (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2634 (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2636 if (cipher_authlen(enc->cipher) == 0) {
2637 if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2639 if ((r = mac_setup(mac, mac->name)) != 0)
2641 if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2642 (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2644 if (maclen > mac->key_len) {
2645 r = SSH_ERR_INVALID_FORMAT;
2648 mac->key_len = maclen;
2650 if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2651 (r = sshbuf_get_u32(b, (u_int *)&comp->enabled)) != 0 ||
2652 (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2654 if (enc->name == NULL ||
2655 cipher_by_name(enc->name) != enc->cipher) {
2656 r = SSH_ERR_INVALID_FORMAT;
2659 if (sshbuf_len(b) != 0) {
2660 r = SSH_ERR_INVALID_FORMAT;
2663 enc->key_len = keylen;
2664 enc->iv_len = ivlen;
2665 ssh->kex->newkeys[mode] = newkey;
2674 /* restore kex from blob for packet state de-serialization */
2676 kex_from_blob(struct sshbuf *m, struct kex **kexp)
2681 if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2682 (kex->my = sshbuf_new()) == NULL ||
2683 (kex->peer = sshbuf_new()) == NULL) {
2684 r = SSH_ERR_ALLOC_FAIL;
2687 if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2688 (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2689 (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2690 (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2691 (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2692 (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2693 (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2694 (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2695 (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2701 if (r != 0 || kexp == NULL) {
2703 sshbuf_free(kex->my);
2704 sshbuf_free(kex->peer);
2716 * Restore packet state from content of blob 'm' (de-serialization).
2717 * Note that 'm' will be partially consumed on parsing or any other errors.
2720 ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2722 struct session_state *state = ssh->state;
2723 const u_char *ssh1key, *ivin, *ivout, *keyin, *keyout, *input, *output;
2724 size_t ssh1keylen, rlen, slen, ilen, olen;
2726 u_int ssh1cipher = 0;
2729 if ((r = sshbuf_get_u32(m, &state->remote_protocol_flags)) != 0 ||
2730 (r = sshbuf_get_u32(m, &ssh1cipher)) != 0 ||
2731 (r = sshbuf_get_string_direct(m, &ssh1key, &ssh1keylen)) != 0 ||
2732 (r = sshbuf_get_string_direct(m, &ivout, &slen)) != 0 ||
2733 (r = sshbuf_get_string_direct(m, &ivin, &rlen)) != 0)
2735 if (ssh1cipher > INT_MAX)
2736 return SSH_ERR_KEY_UNKNOWN_CIPHER;
2737 ssh_packet_set_encryption_key(ssh, ssh1key, ssh1keylen,
2739 if (cipher_get_keyiv_len(&state->send_context) != (int)slen ||
2740 cipher_get_keyiv_len(&state->receive_context) != (int)rlen)
2741 return SSH_ERR_INVALID_FORMAT;
2742 if ((r = cipher_set_keyiv(&state->send_context, ivout)) != 0 ||
2743 (r = cipher_set_keyiv(&state->receive_context, ivin)) != 0)
2746 if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2747 (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2748 (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2749 (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2750 (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2751 (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2752 (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2753 (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2754 (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2755 (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2756 (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2757 (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2758 (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2761 * We set the time here so that in post-auth privsep slave we
2762 * count from the completion of the authentication.
2764 state->rekey_time = monotime();
2765 /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2766 if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2767 (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2770 if ((r = sshbuf_get_string_direct(m, &keyout, &slen)) != 0 ||
2771 (r = sshbuf_get_string_direct(m, &keyin, &rlen)) != 0)
2773 if (cipher_get_keycontext(&state->send_context, NULL) != (int)slen ||
2774 cipher_get_keycontext(&state->receive_context, NULL) != (int)rlen)
2775 return SSH_ERR_INVALID_FORMAT;
2776 cipher_set_keycontext(&state->send_context, keyout);
2777 cipher_set_keycontext(&state->receive_context, keyin);
2779 if ((r = ssh_packet_set_compress_state(ssh, m)) != 0 ||
2780 (r = ssh_packet_set_postauth(ssh)) != 0)
2783 sshbuf_reset(state->input);
2784 sshbuf_reset(state->output);
2785 if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2786 (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2787 (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2788 (r = sshbuf_put(state->output, output, olen)) != 0)
2792 return SSH_ERR_INVALID_FORMAT;
2793 debug3("%s: done", __func__);
2799 /* put data to the outgoing packet */
2802 sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2804 return sshbuf_put(ssh->state->outgoing_packet, v, len);
2808 sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2810 return sshbuf_putb(ssh->state->outgoing_packet, b);
2814 sshpkt_put_u8(struct ssh *ssh, u_char val)
2816 return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2820 sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2822 return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2826 sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2828 return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2832 sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2834 return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2838 sshpkt_put_cstring(struct ssh *ssh, const void *v)
2840 return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2844 sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2846 return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2850 #ifdef OPENSSL_HAS_ECC
2852 sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2854 return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2856 #endif /* OPENSSL_HAS_ECC */
2860 sshpkt_put_bignum1(struct ssh *ssh, const BIGNUM *v)
2862 return sshbuf_put_bignum1(ssh->state->outgoing_packet, v);
2864 #endif /* WITH_SSH1 */
2867 sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2869 return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2871 #endif /* WITH_OPENSSL */
2873 /* fetch data from the incoming packet */
2876 sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2878 return sshbuf_get(ssh->state->incoming_packet, valp, len);
2882 sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2884 return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2888 sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2890 return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2894 sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2896 return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2900 sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2902 return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2906 sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2908 return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2912 sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2914 return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2918 #ifdef OPENSSL_HAS_ECC
2920 sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2922 return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2924 #endif /* OPENSSL_HAS_ECC */
2928 sshpkt_get_bignum1(struct ssh *ssh, BIGNUM *v)
2930 return sshbuf_get_bignum1(ssh->state->incoming_packet, v);
2932 #endif /* WITH_SSH1 */
2935 sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2937 return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2939 #endif /* WITH_OPENSSL */
2942 sshpkt_get_end(struct ssh *ssh)
2944 if (sshbuf_len(ssh->state->incoming_packet) > 0)
2945 return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2950 sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2953 *lenp = sshbuf_len(ssh->state->incoming_packet);
2954 return sshbuf_ptr(ssh->state->incoming_packet);
2957 /* start a new packet */
2960 sshpkt_start(struct ssh *ssh, u_char type)
2965 DBG(debug("packet_start[%d]", type));
2966 len = compat20 ? 6 : 9;
2967 memset(buf, 0, len - 1);
2968 buf[len - 1] = type;
2969 sshbuf_reset(ssh->state->outgoing_packet);
2970 return sshbuf_put(ssh->state->outgoing_packet, buf, len);
2976 sshpkt_send(struct ssh *ssh)
2979 return ssh_packet_send2(ssh);
2981 return ssh_packet_send1(ssh);
2985 sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2991 va_start(args, fmt);
2992 vsnprintf(buf, sizeof(buf), fmt, args);
2996 if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2997 (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2998 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2999 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
3000 (r = sshpkt_send(ssh)) != 0)
3003 if ((r = sshpkt_start(ssh, SSH_MSG_DISCONNECT)) != 0 ||
3004 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
3005 (r = sshpkt_send(ssh)) != 0)
3011 /* roundup current message to pad bytes */
3013 sshpkt_add_padding(struct ssh *ssh, u_char pad)
3015 ssh->state->extra_pad = pad;