92
93#ifdef PACKET_DEBUG
94#define DBG(x) x
95#else
96#define DBG(x)
97#endif
98
99#define PACKET_MAX_SIZE (256 * 1024)
100
101struct packet_state {
102 u_int32_t seqnr;
103 u_int32_t packets;
104 u_int64_t blocks;
105 u_int64_t bytes;
106};
107
108struct packet {
109 TAILQ_ENTRY(packet) next;
110 u_char type;
111 struct sshbuf *payload;
112};
113
114struct session_state {
115 /*
116 * This variable contains the file descriptors used for
117 * communicating with the other side. connection_in is used for
118 * reading; connection_out for writing. These can be the same
119 * descriptor, in which case it is assumed to be a socket.
120 */
121 int connection_in;
122 int connection_out;
123
124 /* Protocol flags for the remote side. */
125 u_int remote_protocol_flags;
126
127 /* Encryption context for receiving data. Only used for decryption. */
128 struct sshcipher_ctx receive_context;
129
130 /* Encryption context for sending data. Only used for encryption. */
131 struct sshcipher_ctx send_context;
132
133 /* Buffer for raw input data from the socket. */
134 struct sshbuf *input;
135
136 /* Buffer for raw output data going to the socket. */
137 struct sshbuf *output;
138
139 /* Buffer for the partial outgoing packet being constructed. */
140 struct sshbuf *outgoing_packet;
141
142 /* Buffer for the incoming packet currently being processed. */
143 struct sshbuf *incoming_packet;
144
145 /* Scratch buffer for packet compression/decompression. */
146 struct sshbuf *compression_buffer;
147
148 /* Incoming/outgoing compression dictionaries */
149 z_stream compression_in_stream;
150 z_stream compression_out_stream;
151 int compression_in_started;
152 int compression_out_started;
153 int compression_in_failures;
154 int compression_out_failures;
155
156 /*
157 * Flag indicating whether packet compression/decompression is
158 * enabled.
159 */
160 int packet_compression;
161
162 /* default maximum packet size */
163 u_int max_packet_size;
164
165 /* Flag indicating whether this module has been initialized. */
166 int initialized;
167
168 /* Set to true if the connection is interactive. */
169 int interactive_mode;
170
171 /* Set to true if we are the server side. */
172 int server_side;
173
174 /* Set to true if we are authenticated. */
175 int after_authentication;
176
177 int keep_alive_timeouts;
178
179 /* The maximum time that we will wait to send or receive a packet */
180 int packet_timeout_ms;
181
182 /* Session key information for Encryption and MAC */
183 struct newkeys *newkeys[MODE_MAX];
184 struct packet_state p_read, p_send;
185
186 /* Volume-based rekeying */
187 u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
188
189 /* Time-based rekeying */
190 u_int32_t rekey_interval; /* how often in seconds */
191 time_t rekey_time; /* time of last rekeying */
192
193 /* Session key for protocol v1 */
194 u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
195 u_int ssh1_keylen;
196
197 /* roundup current message to extra_pad bytes */
198 u_char extra_pad;
199
200 /* XXX discard incoming data after MAC error */
201 u_int packet_discard;
202 struct sshmac *packet_discard_mac;
203
204 /* Used in packet_read_poll2() */
205 u_int packlen;
206
207 /* Used in packet_send2 */
208 int rekeying;
209
210 /* Used in packet_set_interactive */
211 int set_interactive_called;
212
213 /* Used in packet_set_maxsize */
214 int set_maxsize_called;
215
216 /* One-off warning about weak ciphers */
217 int cipher_warning_done;
218
219 /* SSH1 CRC compensation attack detector */
220 struct deattack_ctx deattack;
221
222 TAILQ_HEAD(, packet) outgoing;
223};
224
225struct ssh *
226ssh_alloc_session_state(void)
227{
228 struct ssh *ssh = NULL;
229 struct session_state *state = NULL;
230
231 if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
232 (state = calloc(1, sizeof(*state))) == NULL ||
233 (state->input = sshbuf_new()) == NULL ||
234 (state->output = sshbuf_new()) == NULL ||
235 (state->outgoing_packet = sshbuf_new()) == NULL ||
236 (state->incoming_packet = sshbuf_new()) == NULL)
237 goto fail;
238 TAILQ_INIT(&state->outgoing);
239 TAILQ_INIT(&ssh->private_keys);
240 TAILQ_INIT(&ssh->public_keys);
241 state->connection_in = -1;
242 state->connection_out = -1;
243 state->max_packet_size = 32768;
244 state->packet_timeout_ms = -1;
245 state->p_send.packets = state->p_read.packets = 0;
246 state->initialized = 1;
247 /*
248 * ssh_packet_send2() needs to queue packets until
249 * we've done the initial key exchange.
250 */
251 state->rekeying = 1;
252 ssh->state = state;
253 return ssh;
254 fail:
255 if (state) {
256 sshbuf_free(state->input);
257 sshbuf_free(state->output);
258 sshbuf_free(state->incoming_packet);
259 sshbuf_free(state->outgoing_packet);
260 free(state);
261 }
262 free(ssh);
263 return NULL;
264}
265
266/* Returns nonzero if rekeying is in progress */
267int
268ssh_packet_is_rekeying(struct ssh *ssh)
269{
270 return compat20 &&
271 (ssh->state->rekeying || (ssh->kex != NULL && ssh->kex->done == 0));
272}
273
274/*
275 * Sets the descriptors used for communication. Disables encryption until
276 * packet_set_encryption_key is called.
277 */
278struct ssh *
279ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
280{
281 struct session_state *state;
282 const struct sshcipher *none = cipher_by_name("none");
283 int r;
284
285 if (none == NULL) {
286 error("%s: cannot load cipher 'none'", __func__);
287 return NULL;
288 }
289 if (ssh == NULL)
290 ssh = ssh_alloc_session_state();
291 if (ssh == NULL) {
292 error("%s: cound not allocate state", __func__);
293 return NULL;
294 }
295 state = ssh->state;
296 state->connection_in = fd_in;
297 state->connection_out = fd_out;
298 if ((r = cipher_init(&state->send_context, none,
299 (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
300 (r = cipher_init(&state->receive_context, none,
301 (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
302 error("%s: cipher_init failed: %s", __func__, ssh_err(r));
303 free(ssh);
304 return NULL;
305 }
306 state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
307 deattack_init(&state->deattack);
308 /*
309 * Cache the IP address of the remote connection for use in error
310 * messages that might be generated after the connection has closed.
311 */
312 (void)ssh_remote_ipaddr(ssh);
313 return ssh;
314}
315
316void
317ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
318{
319 struct session_state *state = ssh->state;
320
321 if (timeout <= 0 || count <= 0) {
322 state->packet_timeout_ms = -1;
323 return;
324 }
325 if ((INT_MAX / 1000) / count < timeout)
326 state->packet_timeout_ms = INT_MAX;
327 else
328 state->packet_timeout_ms = timeout * count * 1000;
329}
330
331int
332ssh_packet_stop_discard(struct ssh *ssh)
333{
334 struct session_state *state = ssh->state;
335 int r;
336
337 if (state->packet_discard_mac) {
338 char buf[1024];
339
340 memset(buf, 'a', sizeof(buf));
341 while (sshbuf_len(state->incoming_packet) <
342 PACKET_MAX_SIZE)
343 if ((r = sshbuf_put(state->incoming_packet, buf,
344 sizeof(buf))) != 0)
345 return r;
346 (void) mac_compute(state->packet_discard_mac,
347 state->p_read.seqnr,
348 sshbuf_ptr(state->incoming_packet), PACKET_MAX_SIZE,
349 NULL, 0);
350 }
351 logit("Finished discarding for %.200s port %d",
352 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
353 return SSH_ERR_MAC_INVALID;
354}
355
356static int
357ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
358 struct sshmac *mac, u_int packet_length, u_int discard)
359{
360 struct session_state *state = ssh->state;
361 int r;
362
363 if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
364 if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
365 return r;
366 return SSH_ERR_MAC_INVALID;
367 }
368 if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled)
369 state->packet_discard_mac = mac;
370 if (sshbuf_len(state->input) >= discard &&
371 (r = ssh_packet_stop_discard(ssh)) != 0)
372 return r;
373 state->packet_discard = discard - sshbuf_len(state->input);
374 return 0;
375}
376
377/* Returns 1 if remote host is connected via socket, 0 if not. */
378
379int
380ssh_packet_connection_is_on_socket(struct ssh *ssh)
381{
382 struct session_state *state = ssh->state;
383 struct sockaddr_storage from, to;
384 socklen_t fromlen, tolen;
385
386 /* filedescriptors in and out are the same, so it's a socket */
387 if (state->connection_in == state->connection_out)
388 return 1;
389 fromlen = sizeof(from);
390 memset(&from, 0, sizeof(from));
391 if (getpeername(state->connection_in, (struct sockaddr *)&from,
392 &fromlen) < 0)
393 return 0;
394 tolen = sizeof(to);
395 memset(&to, 0, sizeof(to));
396 if (getpeername(state->connection_out, (struct sockaddr *)&to,
397 &tolen) < 0)
398 return 0;
399 if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
400 return 0;
401 if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
402 return 0;
403 return 1;
404}
405
406void
407ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
408{
409 if (ibytes)
410 *ibytes = ssh->state->p_read.bytes;
411 if (obytes)
412 *obytes = ssh->state->p_send.bytes;
413}
414
415int
416ssh_packet_connection_af(struct ssh *ssh)
417{
418 struct sockaddr_storage to;
419 socklen_t tolen = sizeof(to);
420
421 memset(&to, 0, sizeof(to));
422 if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
423 &tolen) < 0)
424 return 0;
425#ifdef IPV4_IN_IPV6
426 if (to.ss_family == AF_INET6 &&
427 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr))
428 return AF_INET;
429#endif
430 return to.ss_family;
431}
432
433/* Sets the connection into non-blocking mode. */
434
435void
436ssh_packet_set_nonblocking(struct ssh *ssh)
437{
438 /* Set the socket into non-blocking mode. */
439 set_nonblock(ssh->state->connection_in);
440
441 if (ssh->state->connection_out != ssh->state->connection_in)
442 set_nonblock(ssh->state->connection_out);
443}
444
445/* Returns the socket used for reading. */
446
447int
448ssh_packet_get_connection_in(struct ssh *ssh)
449{
450 return ssh->state->connection_in;
451}
452
453/* Returns the descriptor used for writing. */
454
455int
456ssh_packet_get_connection_out(struct ssh *ssh)
457{
458 return ssh->state->connection_out;
459}
460
461/*
462 * Returns the IP-address of the remote host as a string. The returned
463 * string must not be freed.
464 */
465
466const char *
467ssh_remote_ipaddr(struct ssh *ssh)
468{
469 const int sock = ssh->state->connection_in;
470
471 /* Check whether we have cached the ipaddr. */
472 if (ssh->remote_ipaddr == NULL) {
473 if (ssh_packet_connection_is_on_socket(ssh)) {
474 ssh->remote_ipaddr = get_peer_ipaddr(sock);
475 ssh->remote_port = get_sock_port(sock, 0);
476 } else {
477 ssh->remote_ipaddr = strdup("UNKNOWN");
478 ssh->remote_port = 0;
479 }
480 }
481 return ssh->remote_ipaddr;
482}
483
484/* Returns the port number of the remote host. */
485
486int
487ssh_remote_port(struct ssh *ssh)
488{
489 (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
490 return ssh->remote_port;
491}
492
493/* Closes the connection and clears and frees internal data structures. */
494
495void
496ssh_packet_close(struct ssh *ssh)
497{
498 struct session_state *state = ssh->state;
499 int r;
500 u_int mode;
501
502 if (!state->initialized)
503 return;
504 state->initialized = 0;
505 if (state->connection_in == state->connection_out) {
506 shutdown(state->connection_out, SHUT_RDWR);
507 close(state->connection_out);
508 } else {
509 close(state->connection_in);
510 close(state->connection_out);
511 }
512 sshbuf_free(state->input);
513 sshbuf_free(state->output);
514 sshbuf_free(state->outgoing_packet);
515 sshbuf_free(state->incoming_packet);
516 for (mode = 0; mode < MODE_MAX; mode++)
517 kex_free_newkeys(state->newkeys[mode]);
518 if (state->compression_buffer) {
519 sshbuf_free(state->compression_buffer);
520 if (state->compression_out_started) {
521 z_streamp stream = &state->compression_out_stream;
522 debug("compress outgoing: "
523 "raw data %llu, compressed %llu, factor %.2f",
524 (unsigned long long)stream->total_in,
525 (unsigned long long)stream->total_out,
526 stream->total_in == 0 ? 0.0 :
527 (double) stream->total_out / stream->total_in);
528 if (state->compression_out_failures == 0)
529 deflateEnd(stream);
530 }
531 if (state->compression_in_started) {
532 z_streamp stream = &state->compression_out_stream;
533 debug("compress incoming: "
534 "raw data %llu, compressed %llu, factor %.2f",
535 (unsigned long long)stream->total_out,
536 (unsigned long long)stream->total_in,
537 stream->total_out == 0 ? 0.0 :
538 (double) stream->total_in / stream->total_out);
539 if (state->compression_in_failures == 0)
540 inflateEnd(stream);
541 }
542 }
543 if ((r = cipher_cleanup(&state->send_context)) != 0)
544 error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
545 if ((r = cipher_cleanup(&state->receive_context)) != 0)
546 error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
547 free(ssh->remote_ipaddr);
548 ssh->remote_ipaddr = NULL;
549 free(ssh->state);
550 ssh->state = NULL;
551}
552
553/* Sets remote side protocol flags. */
554
555void
556ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
557{
558 ssh->state->remote_protocol_flags = protocol_flags;
559}
560
561/* Returns the remote protocol flags set earlier by the above function. */
562
563u_int
564ssh_packet_get_protocol_flags(struct ssh *ssh)
565{
566 return ssh->state->remote_protocol_flags;
567}
568
569/*
570 * Starts packet compression from the next packet on in both directions.
571 * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
572 */
573
574static int
575ssh_packet_init_compression(struct ssh *ssh)
576{
577 if (!ssh->state->compression_buffer &&
578 ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
579 return SSH_ERR_ALLOC_FAIL;
580 return 0;
581}
582
583static int
584start_compression_out(struct ssh *ssh, int level)
585{
586 if (level < 1 || level > 9)
587 return SSH_ERR_INVALID_ARGUMENT;
588 debug("Enabling compression at level %d.", level);
589 if (ssh->state->compression_out_started == 1)
590 deflateEnd(&ssh->state->compression_out_stream);
591 switch (deflateInit(&ssh->state->compression_out_stream, level)) {
592 case Z_OK:
593 ssh->state->compression_out_started = 1;
594 break;
595 case Z_MEM_ERROR:
596 return SSH_ERR_ALLOC_FAIL;
597 default:
598 return SSH_ERR_INTERNAL_ERROR;
599 }
600 return 0;
601}
602
603static int
604start_compression_in(struct ssh *ssh)
605{
606 if (ssh->state->compression_in_started == 1)
607 inflateEnd(&ssh->state->compression_in_stream);
608 switch (inflateInit(&ssh->state->compression_in_stream)) {
609 case Z_OK:
610 ssh->state->compression_in_started = 1;
611 break;
612 case Z_MEM_ERROR:
613 return SSH_ERR_ALLOC_FAIL;
614 default:
615 return SSH_ERR_INTERNAL_ERROR;
616 }
617 return 0;
618}
619
620int
621ssh_packet_start_compression(struct ssh *ssh, int level)
622{
623 int r;
624
625 if (ssh->state->packet_compression && !compat20)
626 return SSH_ERR_INTERNAL_ERROR;
627 ssh->state->packet_compression = 1;
628 if ((r = ssh_packet_init_compression(ssh)) != 0 ||
629 (r = start_compression_in(ssh)) != 0 ||
630 (r = start_compression_out(ssh, level)) != 0)
631 return r;
632 return 0;
633}
634
635/* XXX remove need for separate compression buffer */
636static int
637compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
638{
639 u_char buf[4096];
640 int r, status;
641
642 if (ssh->state->compression_out_started != 1)
643 return SSH_ERR_INTERNAL_ERROR;
644
645 /* This case is not handled below. */
646 if (sshbuf_len(in) == 0)
647 return 0;
648
649 /* Input is the contents of the input buffer. */
650 if ((ssh->state->compression_out_stream.next_in =
651 sshbuf_mutable_ptr(in)) == NULL)
652 return SSH_ERR_INTERNAL_ERROR;
653 ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
654
655 /* Loop compressing until deflate() returns with avail_out != 0. */
656 do {
657 /* Set up fixed-size output buffer. */
658 ssh->state->compression_out_stream.next_out = buf;
659 ssh->state->compression_out_stream.avail_out = sizeof(buf);
660
661 /* Compress as much data into the buffer as possible. */
662 status = deflate(&ssh->state->compression_out_stream,
663 Z_PARTIAL_FLUSH);
664 switch (status) {
665 case Z_MEM_ERROR:
666 return SSH_ERR_ALLOC_FAIL;
667 case Z_OK:
668 /* Append compressed data to output_buffer. */
669 if ((r = sshbuf_put(out, buf, sizeof(buf) -
670 ssh->state->compression_out_stream.avail_out)) != 0)
671 return r;
672 break;
673 case Z_STREAM_ERROR:
674 default:
675 ssh->state->compression_out_failures++;
676 return SSH_ERR_INVALID_FORMAT;
677 }
678 } while (ssh->state->compression_out_stream.avail_out == 0);
679 return 0;
680}
681
682static int
683uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
684{
685 u_char buf[4096];
686 int r, status;
687
688 if (ssh->state->compression_in_started != 1)
689 return SSH_ERR_INTERNAL_ERROR;
690
691 if ((ssh->state->compression_in_stream.next_in =
692 sshbuf_mutable_ptr(in)) == NULL)
693 return SSH_ERR_INTERNAL_ERROR;
694 ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
695
696 for (;;) {
697 /* Set up fixed-size output buffer. */
698 ssh->state->compression_in_stream.next_out = buf;
699 ssh->state->compression_in_stream.avail_out = sizeof(buf);
700
701 status = inflate(&ssh->state->compression_in_stream,
702 Z_PARTIAL_FLUSH);
703 switch (status) {
704 case Z_OK:
705 if ((r = sshbuf_put(out, buf, sizeof(buf) -
706 ssh->state->compression_in_stream.avail_out)) != 0)
707 return r;
708 break;
709 case Z_BUF_ERROR:
710 /*
711 * Comments in zlib.h say that we should keep calling
712 * inflate() until we get an error. This appears to
713 * be the error that we get.
714 */
715 return 0;
716 case Z_DATA_ERROR:
717 return SSH_ERR_INVALID_FORMAT;
718 case Z_MEM_ERROR:
719 return SSH_ERR_ALLOC_FAIL;
720 case Z_STREAM_ERROR:
721 default:
722 ssh->state->compression_in_failures++;
723 return SSH_ERR_INTERNAL_ERROR;
724 }
725 }
726 /* NOTREACHED */
727}
728
729/* Serialise compression state into a blob for privsep */
730static int
731ssh_packet_get_compress_state(struct sshbuf *m, struct ssh *ssh)
732{
733 struct session_state *state = ssh->state;
734 struct sshbuf *b;
735 int r;
736
737 if ((b = sshbuf_new()) == NULL)
738 return SSH_ERR_ALLOC_FAIL;
739 if (state->compression_in_started) {
740 if ((r = sshbuf_put_string(b, &state->compression_in_stream,
741 sizeof(state->compression_in_stream))) != 0)
742 goto out;
743 } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
744 goto out;
745 if (state->compression_out_started) {
746 if ((r = sshbuf_put_string(b, &state->compression_out_stream,
747 sizeof(state->compression_out_stream))) != 0)
748 goto out;
749 } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
750 goto out;
751 r = sshbuf_put_stringb(m, b);
752 out:
753 sshbuf_free(b);
754 return r;
755}
756
757/* Deserialise compression state from a blob for privsep */
758static int
759ssh_packet_set_compress_state(struct ssh *ssh, struct sshbuf *m)
760{
761 struct session_state *state = ssh->state;
762 struct sshbuf *b = NULL;
763 int r;
764 const u_char *inblob, *outblob;
765 size_t inl, outl;
766
767 if ((r = sshbuf_froms(m, &b)) != 0)
768 goto out;
769 if ((r = sshbuf_get_string_direct(b, &inblob, &inl)) != 0 ||
770 (r = sshbuf_get_string_direct(b, &outblob, &outl)) != 0)
771 goto out;
772 if (inl == 0)
773 state->compression_in_started = 0;
774 else if (inl != sizeof(state->compression_in_stream)) {
775 r = SSH_ERR_INTERNAL_ERROR;
776 goto out;
777 } else {
778 state->compression_in_started = 1;
779 memcpy(&state->compression_in_stream, inblob, inl);
780 }
781 if (outl == 0)
782 state->compression_out_started = 0;
783 else if (outl != sizeof(state->compression_out_stream)) {
784 r = SSH_ERR_INTERNAL_ERROR;
785 goto out;
786 } else {
787 state->compression_out_started = 1;
788 memcpy(&state->compression_out_stream, outblob, outl);
789 }
790 r = 0;
791 out:
792 sshbuf_free(b);
793 return r;
794}
795
796void
797ssh_packet_set_compress_hooks(struct ssh *ssh, void *ctx,
798 void *(*allocfunc)(void *, u_int, u_int),
799 void (*freefunc)(void *, void *))
800{
801 ssh->state->compression_out_stream.zalloc = (alloc_func)allocfunc;
802 ssh->state->compression_out_stream.zfree = (free_func)freefunc;
803 ssh->state->compression_out_stream.opaque = ctx;
804 ssh->state->compression_in_stream.zalloc = (alloc_func)allocfunc;
805 ssh->state->compression_in_stream.zfree = (free_func)freefunc;
806 ssh->state->compression_in_stream.opaque = ctx;
807}
808
809/*
810 * Causes any further packets to be encrypted using the given key. The same
811 * key is used for both sending and reception. However, both directions are
812 * encrypted independently of each other.
813 */
814
815void
816ssh_packet_set_encryption_key(struct ssh *ssh, const u_char *key, u_int keylen, int number)
817{
818#ifndef WITH_SSH1
819 fatal("no SSH protocol 1 support");
820#else /* WITH_SSH1 */
821 struct session_state *state = ssh->state;
822 const struct sshcipher *cipher = cipher_by_number(number);
823 int r;
824 const char *wmsg;
825
826 if (cipher == NULL)
827 fatal("%s: unknown cipher number %d", __func__, number);
828 if (keylen < 20)
829 fatal("%s: keylen too small: %d", __func__, keylen);
830 if (keylen > SSH_SESSION_KEY_LENGTH)
831 fatal("%s: keylen too big: %d", __func__, keylen);
832 memcpy(state->ssh1_key, key, keylen);
833 state->ssh1_keylen = keylen;
834 if ((r = cipher_init(&state->send_context, cipher, key, keylen,
835 NULL, 0, CIPHER_ENCRYPT)) != 0 ||
836 (r = cipher_init(&state->receive_context, cipher, key, keylen,
837 NULL, 0, CIPHER_DECRYPT) != 0))
838 fatal("%s: cipher_init failed: %s", __func__, ssh_err(r));
839 if (!state->cipher_warning_done &&
840 ((wmsg = cipher_warning_message(&state->send_context)) != NULL ||
841 (wmsg = cipher_warning_message(&state->send_context)) != NULL)) {
842 error("Warning: %s", wmsg);
843 state->cipher_warning_done = 1;
844 }
845#endif /* WITH_SSH1 */
846}
847
848/*
849 * Finalizes and sends the packet. If the encryption key has been set,
850 * encrypts the packet before sending.
851 */
852
853int
854ssh_packet_send1(struct ssh *ssh)
855{
856 struct session_state *state = ssh->state;
857 u_char buf[8], *cp;
858 int r, padding, len;
859 u_int checksum;
860
861 /*
862 * If using packet compression, compress the payload of the outgoing
863 * packet.
864 */
865 if (state->packet_compression) {
866 sshbuf_reset(state->compression_buffer);
867 /* Skip padding. */
868 if ((r = sshbuf_consume(state->outgoing_packet, 8)) != 0)
869 goto out;
870 /* padding */
871 if ((r = sshbuf_put(state->compression_buffer,
872 "\0\0\0\0\0\0\0\0", 8)) != 0)
873 goto out;
874 if ((r = compress_buffer(ssh, state->outgoing_packet,
875 state->compression_buffer)) != 0)
876 goto out;
877 sshbuf_reset(state->outgoing_packet);
878 if ((r = sshbuf_putb(state->outgoing_packet,
879 state->compression_buffer)) != 0)
880 goto out;
881 }
882 /* Compute packet length without padding (add checksum, remove padding). */
883 len = sshbuf_len(state->outgoing_packet) + 4 - 8;
884
885 /* Insert padding. Initialized to zero in packet_start1() */
886 padding = 8 - len % 8;
887 if (!state->send_context.plaintext) {
888 cp = sshbuf_mutable_ptr(state->outgoing_packet);
889 if (cp == NULL) {
890 r = SSH_ERR_INTERNAL_ERROR;
891 goto out;
892 }
893 arc4random_buf(cp + 8 - padding, padding);
894 }
895 if ((r = sshbuf_consume(state->outgoing_packet, 8 - padding)) != 0)
896 goto out;
897
898 /* Add check bytes. */
899 checksum = ssh_crc32(sshbuf_ptr(state->outgoing_packet),
900 sshbuf_len(state->outgoing_packet));
901 POKE_U32(buf, checksum);
902 if ((r = sshbuf_put(state->outgoing_packet, buf, 4)) != 0)
903 goto out;
904
905#ifdef PACKET_DEBUG
906 fprintf(stderr, "packet_send plain: ");
907 sshbuf_dump(state->outgoing_packet, stderr);
908#endif
909
910 /* Append to output. */
911 POKE_U32(buf, len);
912 if ((r = sshbuf_put(state->output, buf, 4)) != 0)
913 goto out;
914 if ((r = sshbuf_reserve(state->output,
915 sshbuf_len(state->outgoing_packet), &cp)) != 0)
916 goto out;
917 if ((r = cipher_crypt(&state->send_context, 0, cp,
918 sshbuf_ptr(state->outgoing_packet),
919 sshbuf_len(state->outgoing_packet), 0, 0)) != 0)
920 goto out;
921
922#ifdef PACKET_DEBUG
923 fprintf(stderr, "encrypted: ");
924 sshbuf_dump(state->output, stderr);
925#endif
926 state->p_send.packets++;
927 state->p_send.bytes += len +
928 sshbuf_len(state->outgoing_packet);
929 sshbuf_reset(state->outgoing_packet);
930
931 /*
932 * Note that the packet is now only buffered in output. It won't be
933 * actually sent until ssh_packet_write_wait or ssh_packet_write_poll
934 * is called.
935 */
936 r = 0;
937 out:
938 return r;
939}
940
941int
942ssh_set_newkeys(struct ssh *ssh, int mode)
943{
944 struct session_state *state = ssh->state;
945 struct sshenc *enc;
946 struct sshmac *mac;
947 struct sshcomp *comp;
948 struct sshcipher_ctx *cc;
949 u_int64_t *max_blocks;
950 const char *wmsg;
951 int r, crypt_type;
952
953 debug2("set_newkeys: mode %d", mode);
954
955 if (mode == MODE_OUT) {
956 cc = &state->send_context;
957 crypt_type = CIPHER_ENCRYPT;
958 state->p_send.packets = state->p_send.blocks = 0;
959 max_blocks = &state->max_blocks_out;
960 } else {
961 cc = &state->receive_context;
962 crypt_type = CIPHER_DECRYPT;
963 state->p_read.packets = state->p_read.blocks = 0;
964 max_blocks = &state->max_blocks_in;
965 }
966 if (state->newkeys[mode] != NULL) {
967 debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
968 "output %llu bytes %llu blocks",
969 (unsigned long long)state->p_read.bytes,
970 (unsigned long long)state->p_read.blocks,
971 (unsigned long long)state->p_send.bytes,
972 (unsigned long long)state->p_send.blocks);
973 if ((r = cipher_cleanup(cc)) != 0)
974 return r;
975 enc = &state->newkeys[mode]->enc;
976 mac = &state->newkeys[mode]->mac;
977 comp = &state->newkeys[mode]->comp;
978 mac_clear(mac);
979 explicit_bzero(enc->iv, enc->iv_len);
980 explicit_bzero(enc->key, enc->key_len);
981 explicit_bzero(mac->key, mac->key_len);
982 free(enc->name);
983 free(enc->iv);
984 free(enc->key);
985 free(mac->name);
986 free(mac->key);
987 free(comp->name);
988 free(state->newkeys[mode]);
989 }
990 /* move newkeys from kex to state */
991 if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
992 return SSH_ERR_INTERNAL_ERROR;
993 ssh->kex->newkeys[mode] = NULL;
994 enc = &state->newkeys[mode]->enc;
995 mac = &state->newkeys[mode]->mac;
996 comp = &state->newkeys[mode]->comp;
997 if (cipher_authlen(enc->cipher) == 0) {
998 if ((r = mac_init(mac)) != 0)
999 return r;
1000 }
1001 mac->enabled = 1;
1002 DBG(debug("cipher_init_context: %d", mode));
1003 if ((r = cipher_init(cc, enc->cipher, enc->key, enc->key_len,
1004 enc->iv, enc->iv_len, crypt_type)) != 0)
1005 return r;
1006 if (!state->cipher_warning_done &&
1007 (wmsg = cipher_warning_message(cc)) != NULL) {
1008 error("Warning: %s", wmsg);
1009 state->cipher_warning_done = 1;
1010 }
1011 /* Deleting the keys does not gain extra security */
1012 /* explicit_bzero(enc->iv, enc->block_size);
1013 explicit_bzero(enc->key, enc->key_len);
1014 explicit_bzero(mac->key, mac->key_len); */
1015 if ((comp->type == COMP_ZLIB ||
1016 (comp->type == COMP_DELAYED &&
1017 state->after_authentication)) && comp->enabled == 0) {
1018 if ((r = ssh_packet_init_compression(ssh)) < 0)
1019 return r;
1020 if (mode == MODE_OUT) {
1021 if ((r = start_compression_out(ssh, 6)) != 0)
1022 return r;
1023 } else {
1024 if ((r = start_compression_in(ssh)) != 0)
1025 return r;
1026 }
1027 comp->enabled = 1;
1028 }
1029 /*
1030 * The 2^(blocksize*2) limit is too expensive for 3DES,
1031 * blowfish, etc, so enforce a 1GB limit for small blocksizes.
1032 */
1033 if (enc->block_size >= 16)
1034 *max_blocks = (u_int64_t)1 << (enc->block_size*2);
1035 else
1036 *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1037 if (state->rekey_limit)
1038 *max_blocks = MIN(*max_blocks,
1039 state->rekey_limit / enc->block_size);
1040 debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1041 return 0;
1042}
1043
1044#define MAX_PACKETS (1U<<31)
1045static int
1046ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
1047{
1048 struct session_state *state = ssh->state;
1049 u_int32_t out_blocks;
1050
1051 /* XXX client can't cope with rekeying pre-auth */
1052 if (!state->after_authentication)
1053 return 0;
1054
1055 /* Haven't keyed yet or KEX in progress. */
1056 if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
1057 return 0;
1058
1059 /* Peer can't rekey */
1060 if (ssh->compat & SSH_BUG_NOREKEY)
1061 return 0;
1062
1063 /*
1064 * Permit one packet in or out per rekey - this allows us to
1065 * make progress when rekey limits are very small.
1066 */
1067 if (state->p_send.packets == 0 && state->p_read.packets == 0)
1068 return 0;
1069
1070 /* Time-based rekeying */
1071 if (state->rekey_interval != 0 &&
1072 state->rekey_time + state->rekey_interval <= monotime())
1073 return 1;
1074
1075 /* Always rekey when MAX_PACKETS sent in either direction */
1076 if (state->p_send.packets > MAX_PACKETS ||
1077 state->p_read.packets > MAX_PACKETS)
1078 return 1;
1079
1080 /* Rekey after (cipher-specific) maxiumum blocks */
1081 out_blocks = roundup(outbound_packet_len,
1082 state->newkeys[MODE_OUT]->enc.block_size);
1083 return (state->max_blocks_out &&
1084 (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
1085 (state->max_blocks_in &&
1086 (state->p_read.blocks > state->max_blocks_in));
1087}
1088
1089/*
1090 * Delayed compression for SSH2 is enabled after authentication:
1091 * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1092 * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
1093 */
1094static int
1095ssh_packet_enable_delayed_compress(struct ssh *ssh)
1096{
1097 struct session_state *state = ssh->state;
1098 struct sshcomp *comp = NULL;
1099 int r, mode;
1100
1101 /*
1102 * Remember that we are past the authentication step, so rekeying
1103 * with COMP_DELAYED will turn on compression immediately.
1104 */
1105 state->after_authentication = 1;
1106 for (mode = 0; mode < MODE_MAX; mode++) {
1107 /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1108 if (state->newkeys[mode] == NULL)
1109 continue;
1110 comp = &state->newkeys[mode]->comp;
1111 if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1112 if ((r = ssh_packet_init_compression(ssh)) != 0)
1113 return r;
1114 if (mode == MODE_OUT) {
1115 if ((r = start_compression_out(ssh, 6)) != 0)
1116 return r;
1117 } else {
1118 if ((r = start_compression_in(ssh)) != 0)
1119 return r;
1120 }
1121 comp->enabled = 1;
1122 }
1123 }
1124 return 0;
1125}
1126
1127/* Used to mute debug logging for noisy packet types */
1128static int
1129ssh_packet_log_type(u_char type)
1130{
1131 switch (type) {
1132 case SSH2_MSG_CHANNEL_DATA:
1133 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1134 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1135 return 0;
1136 default:
1137 return 1;
1138 }
1139}
1140
1141/*
1142 * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1143 */
1144int
1145ssh_packet_send2_wrapped(struct ssh *ssh)
1146{
1147 struct session_state *state = ssh->state;
1148 u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1149 u_char padlen, pad = 0;
1150 u_int authlen = 0, aadlen = 0;
1151 u_int len;
1152 struct sshenc *enc = NULL;
1153 struct sshmac *mac = NULL;
1154 struct sshcomp *comp = NULL;
1155 int r, block_size;
1156
1157 if (state->newkeys[MODE_OUT] != NULL) {
1158 enc = &state->newkeys[MODE_OUT]->enc;
1159 mac = &state->newkeys[MODE_OUT]->mac;
1160 comp = &state->newkeys[MODE_OUT]->comp;
1161 /* disable mac for authenticated encryption */
1162 if ((authlen = cipher_authlen(enc->cipher)) != 0)
1163 mac = NULL;
1164 }
1165 block_size = enc ? enc->block_size : 8;
1166 aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1167
1168 type = (sshbuf_ptr(state->outgoing_packet))[5];
1169 if (ssh_packet_log_type(type))
1170 debug3("send packet: type %u", type);
1171#ifdef PACKET_DEBUG
1172 fprintf(stderr, "plain: ");
1173 sshbuf_dump(state->outgoing_packet, stderr);
1174#endif
1175
1176 if (comp && comp->enabled) {
1177 len = sshbuf_len(state->outgoing_packet);
1178 /* skip header, compress only payload */
1179 if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1180 goto out;
1181 sshbuf_reset(state->compression_buffer);
1182 if ((r = compress_buffer(ssh, state->outgoing_packet,
1183 state->compression_buffer)) != 0)
1184 goto out;
1185 sshbuf_reset(state->outgoing_packet);
1186 if ((r = sshbuf_put(state->outgoing_packet,
1187 "\0\0\0\0\0", 5)) != 0 ||
1188 (r = sshbuf_putb(state->outgoing_packet,
1189 state->compression_buffer)) != 0)
1190 goto out;
1191 DBG(debug("compression: raw %d compressed %zd", len,
1192 sshbuf_len(state->outgoing_packet)));
1193 }
1194
1195 /* sizeof (packet_len + pad_len + payload) */
1196 len = sshbuf_len(state->outgoing_packet);
1197
1198 /*
1199 * calc size of padding, alloc space, get random data,
1200 * minimum padding is 4 bytes
1201 */
1202 len -= aadlen; /* packet length is not encrypted for EtM modes */
1203 padlen = block_size - (len % block_size);
1204 if (padlen < 4)
1205 padlen += block_size;
1206 if (state->extra_pad) {
1207 /* will wrap if extra_pad+padlen > 255 */
1208 state->extra_pad =
1209 roundup(state->extra_pad, block_size);
1210 pad = state->extra_pad -
1211 ((len + padlen) % state->extra_pad);
1212 DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1213 __func__, pad, len, padlen, state->extra_pad));
1214 padlen += pad;
1215 state->extra_pad = 0;
1216 }
1217 if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1218 goto out;
1219 if (enc && !state->send_context.plaintext) {
1220 /* random padding */
1221 arc4random_buf(cp, padlen);
1222 } else {
1223 /* clear padding */
1224 explicit_bzero(cp, padlen);
1225 }
1226 /* sizeof (packet_len + pad_len + payload + padding) */
1227 len = sshbuf_len(state->outgoing_packet);
1228 cp = sshbuf_mutable_ptr(state->outgoing_packet);
1229 if (cp == NULL) {
1230 r = SSH_ERR_INTERNAL_ERROR;
1231 goto out;
1232 }
1233 /* packet_length includes payload, padding and padding length field */
1234 POKE_U32(cp, len - 4);
1235 cp[4] = padlen;
1236 DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1237 len, padlen, aadlen));
1238
1239 /* compute MAC over seqnr and packet(length fields, payload, padding) */
1240 if (mac && mac->enabled && !mac->etm) {
1241 if ((r = mac_compute(mac, state->p_send.seqnr,
1242 sshbuf_ptr(state->outgoing_packet), len,
1243 macbuf, sizeof(macbuf))) != 0)
1244 goto out;
1245 DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1246 }
1247 /* encrypt packet and append to output buffer. */
1248 if ((r = sshbuf_reserve(state->output,
1249 sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1250 goto out;
1251 if ((r = cipher_crypt(&state->send_context, state->p_send.seqnr, cp,
1252 sshbuf_ptr(state->outgoing_packet),
1253 len - aadlen, aadlen, authlen)) != 0)
1254 goto out;
1255 /* append unencrypted MAC */
1256 if (mac && mac->enabled) {
1257 if (mac->etm) {
1258 /* EtM: compute mac over aadlen + cipher text */
1259 if ((r = mac_compute(mac, state->p_send.seqnr,
1260 cp, len, macbuf, sizeof(macbuf))) != 0)
1261 goto out;
1262 DBG(debug("done calc MAC(EtM) out #%d",
1263 state->p_send.seqnr));
1264 }
1265 if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1266 goto out;
1267 }
1268#ifdef PACKET_DEBUG
1269 fprintf(stderr, "encrypted: ");
1270 sshbuf_dump(state->output, stderr);
1271#endif
1272 /* increment sequence number for outgoing packets */
1273 if (++state->p_send.seqnr == 0)
1274 logit("outgoing seqnr wraps around");
1275 if (++state->p_send.packets == 0)
1276 if (!(ssh->compat & SSH_BUG_NOREKEY))
1277 return SSH_ERR_NEED_REKEY;
1278 state->p_send.blocks += len / block_size;
1279 state->p_send.bytes += len;
1280 sshbuf_reset(state->outgoing_packet);
1281
1282 if (type == SSH2_MSG_NEWKEYS)
1283 r = ssh_set_newkeys(ssh, MODE_OUT);
1284 else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1285 r = ssh_packet_enable_delayed_compress(ssh);
1286 else
1287 r = 0;
1288 out:
1289 return r;
1290}
1291
1292/* returns non-zero if the specified packet type is usec by KEX */
1293static int
1294ssh_packet_type_is_kex(u_char type)
1295{
1296 return
1297 type >= SSH2_MSG_TRANSPORT_MIN &&
1298 type <= SSH2_MSG_TRANSPORT_MAX &&
1299 type != SSH2_MSG_SERVICE_REQUEST &&
1300 type != SSH2_MSG_SERVICE_ACCEPT &&
1301 type != SSH2_MSG_EXT_INFO;
1302}
1303
1304int
1305ssh_packet_send2(struct ssh *ssh)
1306{
1307 struct session_state *state = ssh->state;
1308 struct packet *p;
1309 u_char type;
1310 int r, need_rekey;
1311
1312 if (sshbuf_len(state->outgoing_packet) < 6)
1313 return SSH_ERR_INTERNAL_ERROR;
1314 type = sshbuf_ptr(state->outgoing_packet)[5];
1315 need_rekey = !ssh_packet_type_is_kex(type) &&
1316 ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1317
1318 /*
1319 * During rekeying we can only send key exchange messages.
1320 * Queue everything else.
1321 */
1322 if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1323 if (need_rekey)
1324 debug3("%s: rekex triggered", __func__);
1325 debug("enqueue packet: %u", type);
1326 p = calloc(1, sizeof(*p));
1327 if (p == NULL)
1328 return SSH_ERR_ALLOC_FAIL;
1329 p->type = type;
1330 p->payload = state->outgoing_packet;
1331 TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1332 state->outgoing_packet = sshbuf_new();
1333 if (state->outgoing_packet == NULL)
1334 return SSH_ERR_ALLOC_FAIL;
1335 if (need_rekey) {
1336 /*
1337 * This packet triggered a rekey, so send the
1338 * KEXINIT now.
1339 * NB. reenters this function via kex_start_rekex().
1340 */
1341 return kex_start_rekex(ssh);
1342 }
1343 return 0;
1344 }
1345
1346 /* rekeying starts with sending KEXINIT */
1347 if (type == SSH2_MSG_KEXINIT)
1348 state->rekeying = 1;
1349
1350 if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1351 return r;
1352
1353 /* after a NEWKEYS message we can send the complete queue */
1354 if (type == SSH2_MSG_NEWKEYS) {
1355 state->rekeying = 0;
1356 state->rekey_time = monotime();
1357 while ((p = TAILQ_FIRST(&state->outgoing))) {
1358 type = p->type;
1359 /*
1360 * If this packet triggers a rekex, then skip the
1361 * remaining packets in the queue for now.
1362 * NB. re-enters this function via kex_start_rekex.
1363 */
1364 if (ssh_packet_need_rekeying(ssh,
1365 sshbuf_len(p->payload))) {
1366 debug3("%s: queued packet triggered rekex",
1367 __func__);
1368 return kex_start_rekex(ssh);
1369 }
1370 debug("dequeue packet: %u", type);
1371 sshbuf_free(state->outgoing_packet);
1372 state->outgoing_packet = p->payload;
1373 TAILQ_REMOVE(&state->outgoing, p, next);
1374 memset(p, 0, sizeof(*p));
1375 free(p);
1376 if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1377 return r;
1378 }
1379 }
1380 return 0;
1381}
1382
1383/*
1384 * Waits until a packet has been received, and returns its type. Note that
1385 * no other data is processed until this returns, so this function should not
1386 * be used during the interactive session.
1387 */
1388
1389int
1390ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1391{
1392 struct session_state *state = ssh->state;
1393 int len, r, ms_remain;
1394 fd_set *setp;
1395 char buf[8192];
1396 struct timeval timeout, start, *timeoutp = NULL;
1397
1398 DBG(debug("packet_read()"));
1399
1400 setp = calloc(howmany(state->connection_in + 1,
1401 NFDBITS), sizeof(fd_mask));
1402 if (setp == NULL)
1403 return SSH_ERR_ALLOC_FAIL;
1404
1405 /*
1406 * Since we are blocking, ensure that all written packets have
1407 * been sent.
1408 */
1409 if ((r = ssh_packet_write_wait(ssh)) != 0)
1410 goto out;
1411
1412 /* Stay in the loop until we have received a complete packet. */
1413 for (;;) {
1414 /* Try to read a packet from the buffer. */
1415 r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1416 if (r != 0)
1417 break;
1418 if (!compat20 && (
1419 *typep == SSH_SMSG_SUCCESS
1420 || *typep == SSH_SMSG_FAILURE
1421 || *typep == SSH_CMSG_EOF
1422 || *typep == SSH_CMSG_EXIT_CONFIRMATION))
1423 if ((r = sshpkt_get_end(ssh)) != 0)
1424 break;
1425 /* If we got a packet, return it. */
1426 if (*typep != SSH_MSG_NONE)
1427 break;
1428 /*
1429 * Otherwise, wait for some data to arrive, add it to the
1430 * buffer, and try again.
1431 */
1432 memset(setp, 0, howmany(state->connection_in + 1,
1433 NFDBITS) * sizeof(fd_mask));
1434 FD_SET(state->connection_in, setp);
1435
1436 if (state->packet_timeout_ms > 0) {
1437 ms_remain = state->packet_timeout_ms;
1438 timeoutp = &timeout;
1439 }
1440 /* Wait for some data to arrive. */
1441 for (;;) {
1442 if (state->packet_timeout_ms != -1) {
1443 ms_to_timeval(&timeout, ms_remain);
1444 gettimeofday(&start, NULL);
1445 }
1446 if ((r = select(state->connection_in + 1, setp,
1447 NULL, NULL, timeoutp)) >= 0)
1448 break;
1449 if (errno != EAGAIN && errno != EINTR &&
1450 errno != EWOULDBLOCK)
1451 break;
1452 if (state->packet_timeout_ms == -1)
1453 continue;
1454 ms_subtract_diff(&start, &ms_remain);
1455 if (ms_remain <= 0) {
1456 r = 0;
1457 break;
1458 }
1459 }
1460 if (r == 0)
1461 return SSH_ERR_CONN_TIMEOUT;
1462 /* Read data from the socket. */
1463 len = read(state->connection_in, buf, sizeof(buf));
1464 if (len == 0) {
1465 r = SSH_ERR_CONN_CLOSED;
1466 goto out;
1467 }
1468 if (len < 0) {
1469 r = SSH_ERR_SYSTEM_ERROR;
1470 goto out;
1471 }
1472
1473 /* Append it to the buffer. */
1474 if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1475 goto out;
1476 }
1477 out:
1478 free(setp);
1479 return r;
1480}
1481
1482int
1483ssh_packet_read(struct ssh *ssh)
1484{
1485 u_char type;
1486 int r;
1487
1488 if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1489 fatal("%s: %s", __func__, ssh_err(r));
1490 return type;
1491}
1492
1493/*
1494 * Waits until a packet has been received, verifies that its type matches
1495 * that given, and gives a fatal error and exits if there is a mismatch.
1496 */
1497
1498int
1499ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1500{
1501 int r;
1502 u_char type;
1503
1504 if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1505 return r;
1506 if (type != expected_type) {
1507 if ((r = sshpkt_disconnect(ssh,
1508 "Protocol error: expected packet type %d, got %d",
1509 expected_type, type)) != 0)
1510 return r;
1511 return SSH_ERR_PROTOCOL_ERROR;
1512 }
1513 return 0;
1514}
1515
1516/* Checks if a full packet is available in the data received so far via
1517 * packet_process_incoming. If so, reads the packet; otherwise returns
1518 * SSH_MSG_NONE. This does not wait for data from the connection.
1519 *
1520 * SSH_MSG_DISCONNECT is handled specially here. Also,
1521 * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1522 * to higher levels.
1523 */
1524
1525int
1526ssh_packet_read_poll1(struct ssh *ssh, u_char *typep)
1527{
1528 struct session_state *state = ssh->state;
1529 u_int len, padded_len;
1530 const char *emsg;
1531 const u_char *cp;
1532 u_char *p;
1533 u_int checksum, stored_checksum;
1534 int r;
1535
1536 *typep = SSH_MSG_NONE;
1537
1538 /* Check if input size is less than minimum packet size. */
1539 if (sshbuf_len(state->input) < 4 + 8)
1540 return 0;
1541 /* Get length of incoming packet. */
1542 len = PEEK_U32(sshbuf_ptr(state->input));
1543 if (len < 1 + 2 + 2 || len > 256 * 1024) {
1544 if ((r = sshpkt_disconnect(ssh, "Bad packet length %u",
1545 len)) != 0)
1546 return r;
1547 return SSH_ERR_CONN_CORRUPT;
1548 }
1549 padded_len = (len + 8) & ~7;
1550
1551 /* Check if the packet has been entirely received. */
1552 if (sshbuf_len(state->input) < 4 + padded_len)
1553 return 0;
1554
1555 /* The entire packet is in buffer. */
1556
1557 /* Consume packet length. */
1558 if ((r = sshbuf_consume(state->input, 4)) != 0)
1559 goto out;
1560
1561 /*
1562 * Cryptographic attack detector for ssh
1563 * (C)1998 CORE-SDI, Buenos Aires Argentina
1564 * Ariel Futoransky(futo@core-sdi.com)
1565 */
1566 if (!state->receive_context.plaintext) {
1567 emsg = NULL;
1568 switch (detect_attack(&state->deattack,
1569 sshbuf_ptr(state->input), padded_len)) {
1570 case DEATTACK_OK:
1571 break;
1572 case DEATTACK_DETECTED:
1573 emsg = "crc32 compensation attack detected";
1574 break;
1575 case DEATTACK_DOS_DETECTED:
1576 emsg = "deattack denial of service detected";
1577 break;
1578 default:
1579 emsg = "deattack error";
1580 break;
1581 }
1582 if (emsg != NULL) {
1583 error("%s", emsg);
1584 if ((r = sshpkt_disconnect(ssh, "%s", emsg)) != 0 ||
1585 (r = ssh_packet_write_wait(ssh)) != 0)
1586 return r;
1587 return SSH_ERR_CONN_CORRUPT;
1588 }
1589 }
1590
1591 /* Decrypt data to incoming_packet. */
1592 sshbuf_reset(state->incoming_packet);
1593 if ((r = sshbuf_reserve(state->incoming_packet, padded_len, &p)) != 0)
1594 goto out;
1595 if ((r = cipher_crypt(&state->receive_context, 0, p,
1596 sshbuf_ptr(state->input), padded_len, 0, 0)) != 0)
1597 goto out;
1598
1599 if ((r = sshbuf_consume(state->input, padded_len)) != 0)
1600 goto out;
1601
1602#ifdef PACKET_DEBUG
1603 fprintf(stderr, "read_poll plain: ");
1604 sshbuf_dump(state->incoming_packet, stderr);
1605#endif
1606
1607 /* Compute packet checksum. */
1608 checksum = ssh_crc32(sshbuf_ptr(state->incoming_packet),
1609 sshbuf_len(state->incoming_packet) - 4);
1610
1611 /* Skip padding. */
1612 if ((r = sshbuf_consume(state->incoming_packet, 8 - len % 8)) != 0)
1613 goto out;
1614
1615 /* Test check bytes. */
1616 if (len != sshbuf_len(state->incoming_packet)) {
1617 error("%s: len %d != sshbuf_len %zd", __func__,
1618 len, sshbuf_len(state->incoming_packet));
1619 if ((r = sshpkt_disconnect(ssh, "invalid packet length")) != 0 ||
1620 (r = ssh_packet_write_wait(ssh)) != 0)
1621 return r;
1622 return SSH_ERR_CONN_CORRUPT;
1623 }
1624
1625 cp = sshbuf_ptr(state->incoming_packet) + len - 4;
1626 stored_checksum = PEEK_U32(cp);
1627 if (checksum != stored_checksum) {
1628 error("Corrupted check bytes on input");
1629 if ((r = sshpkt_disconnect(ssh, "connection corrupted")) != 0 ||
1630 (r = ssh_packet_write_wait(ssh)) != 0)
1631 return r;
1632 return SSH_ERR_CONN_CORRUPT;
1633 }
1634 if ((r = sshbuf_consume_end(state->incoming_packet, 4)) < 0)
1635 goto out;
1636
1637 if (state->packet_compression) {
1638 sshbuf_reset(state->compression_buffer);
1639 if ((r = uncompress_buffer(ssh, state->incoming_packet,
1640 state->compression_buffer)) != 0)
1641 goto out;
1642 sshbuf_reset(state->incoming_packet);
1643 if ((r = sshbuf_putb(state->incoming_packet,
1644 state->compression_buffer)) != 0)
1645 goto out;
1646 }
1647 state->p_read.packets++;
1648 state->p_read.bytes += padded_len + 4;
1649 if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1650 goto out;
1651 if (*typep < SSH_MSG_MIN || *typep > SSH_MSG_MAX) {
1652 error("Invalid ssh1 packet type: %d", *typep);
1653 if ((r = sshpkt_disconnect(ssh, "invalid packet type")) != 0 ||
1654 (r = ssh_packet_write_wait(ssh)) != 0)
1655 return r;
1656 return SSH_ERR_PROTOCOL_ERROR;
1657 }
1658 r = 0;
1659 out:
1660 return r;
1661}
1662
1663int
1664ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1665{
1666 struct session_state *state = ssh->state;
1667 u_int padlen, need;
1668 u_char *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1669 u_int maclen, aadlen = 0, authlen = 0, block_size;
1670 struct sshenc *enc = NULL;
1671 struct sshmac *mac = NULL;
1672 struct sshcomp *comp = NULL;
1673 int r;
1674
1675 *typep = SSH_MSG_NONE;
1676
1677 if (state->packet_discard)
1678 return 0;
1679
1680 if (state->newkeys[MODE_IN] != NULL) {
1681 enc = &state->newkeys[MODE_IN]->enc;
1682 mac = &state->newkeys[MODE_IN]->mac;
1683 comp = &state->newkeys[MODE_IN]->comp;
1684 /* disable mac for authenticated encryption */
1685 if ((authlen = cipher_authlen(enc->cipher)) != 0)
1686 mac = NULL;
1687 }
1688 maclen = mac && mac->enabled ? mac->mac_len : 0;
1689 block_size = enc ? enc->block_size : 8;
1690 aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1691
1692 if (aadlen && state->packlen == 0) {
1693 if (cipher_get_length(&state->receive_context,
1694 &state->packlen, state->p_read.seqnr,
1695 sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1696 return 0;
1697 if (state->packlen < 1 + 4 ||
1698 state->packlen > PACKET_MAX_SIZE) {
1699#ifdef PACKET_DEBUG
1700 sshbuf_dump(state->input, stderr);
1701#endif
1702 logit("Bad packet length %u.", state->packlen);
1703 if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1704 return r;
1705 return SSH_ERR_CONN_CORRUPT;
1706 }
1707 sshbuf_reset(state->incoming_packet);
1708 } else if (state->packlen == 0) {
1709 /*
1710 * check if input size is less than the cipher block size,
1711 * decrypt first block and extract length of incoming packet
1712 */
1713 if (sshbuf_len(state->input) < block_size)
1714 return 0;
1715 sshbuf_reset(state->incoming_packet);
1716 if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1717 &cp)) != 0)
1718 goto out;
1719 if ((r = cipher_crypt(&state->receive_context,
1720 state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1721 block_size, 0, 0)) != 0)
1722 goto out;
1723 state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1724 if (state->packlen < 1 + 4 ||
1725 state->packlen > PACKET_MAX_SIZE) {
1726#ifdef PACKET_DEBUG
1727 fprintf(stderr, "input: \n");
1728 sshbuf_dump(state->input, stderr);
1729 fprintf(stderr, "incoming_packet: \n");
1730 sshbuf_dump(state->incoming_packet, stderr);
1731#endif
1732 logit("Bad packet length %u.", state->packlen);
1733 return ssh_packet_start_discard(ssh, enc, mac,
1734 state->packlen, PACKET_MAX_SIZE);
1735 }
1736 if ((r = sshbuf_consume(state->input, block_size)) != 0)
1737 goto out;
1738 }
1739 DBG(debug("input: packet len %u", state->packlen+4));
1740
1741 if (aadlen) {
1742 /* only the payload is encrypted */
1743 need = state->packlen;
1744 } else {
1745 /*
1746 * the payload size and the payload are encrypted, but we
1747 * have a partial packet of block_size bytes
1748 */
1749 need = 4 + state->packlen - block_size;
1750 }
1751 DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1752 " aadlen %d", block_size, need, maclen, authlen, aadlen));
1753 if (need % block_size != 0) {
1754 logit("padding error: need %d block %d mod %d",
1755 need, block_size, need % block_size);
1756 return ssh_packet_start_discard(ssh, enc, mac,
1757 state->packlen, PACKET_MAX_SIZE - block_size);
1758 }
1759 /*
1760 * check if the entire packet has been received and
1761 * decrypt into incoming_packet:
1762 * 'aadlen' bytes are unencrypted, but authenticated.
1763 * 'need' bytes are encrypted, followed by either
1764 * 'authlen' bytes of authentication tag or
1765 * 'maclen' bytes of message authentication code.
1766 */
1767 if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1768 return 0;
1769#ifdef PACKET_DEBUG
1770 fprintf(stderr, "read_poll enc/full: ");
1771 sshbuf_dump(state->input, stderr);
1772#endif
1773 /* EtM: compute mac over encrypted input */
1774 if (mac && mac->enabled && mac->etm) {
1775 if ((r = mac_compute(mac, state->p_read.seqnr,
1776 sshbuf_ptr(state->input), aadlen + need,
1777 macbuf, sizeof(macbuf))) != 0)
1778 goto out;
1779 }
1780 if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1781 &cp)) != 0)
1782 goto out;
1783 if ((r = cipher_crypt(&state->receive_context, state->p_read.seqnr, cp,
1784 sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1785 goto out;
1786 if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1787 goto out;
1788 /*
1789 * compute MAC over seqnr and packet,
1790 * increment sequence number for incoming packet
1791 */
1792 if (mac && mac->enabled) {
1793 if (!mac->etm)
1794 if ((r = mac_compute(mac, state->p_read.seqnr,
1795 sshbuf_ptr(state->incoming_packet),
1796 sshbuf_len(state->incoming_packet),
1797 macbuf, sizeof(macbuf))) != 0)
1798 goto out;
1799 if (timingsafe_bcmp(macbuf, sshbuf_ptr(state->input),
1800 mac->mac_len) != 0) {
1801 logit("Corrupted MAC on input.");
1802 if (need > PACKET_MAX_SIZE)
1803 return SSH_ERR_INTERNAL_ERROR;
1804 return ssh_packet_start_discard(ssh, enc, mac,
1805 state->packlen, PACKET_MAX_SIZE - need);
1806 }
1807
1808 DBG(debug("MAC #%d ok", state->p_read.seqnr));
1809 if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1810 goto out;
1811 }
1812 if (seqnr_p != NULL)
1813 *seqnr_p = state->p_read.seqnr;
1814 if (++state->p_read.seqnr == 0)
1815 logit("incoming seqnr wraps around");
1816 if (++state->p_read.packets == 0)
1817 if (!(ssh->compat & SSH_BUG_NOREKEY))
1818 return SSH_ERR_NEED_REKEY;
1819 state->p_read.blocks += (state->packlen + 4) / block_size;
1820 state->p_read.bytes += state->packlen + 4;
1821
1822 /* get padlen */
1823 padlen = sshbuf_ptr(state->incoming_packet)[4];
1824 DBG(debug("input: padlen %d", padlen));
1825 if (padlen < 4) {
1826 if ((r = sshpkt_disconnect(ssh,
1827 "Corrupted padlen %d on input.", padlen)) != 0 ||
1828 (r = ssh_packet_write_wait(ssh)) != 0)
1829 return r;
1830 return SSH_ERR_CONN_CORRUPT;
1831 }
1832
1833 /* skip packet size + padlen, discard padding */
1834 if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1835 ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1836 goto out;
1837
1838 DBG(debug("input: len before de-compress %zd",
1839 sshbuf_len(state->incoming_packet)));
1840 if (comp && comp->enabled) {
1841 sshbuf_reset(state->compression_buffer);
1842 if ((r = uncompress_buffer(ssh, state->incoming_packet,
1843 state->compression_buffer)) != 0)
1844 goto out;
1845 sshbuf_reset(state->incoming_packet);
1846 if ((r = sshbuf_putb(state->incoming_packet,
1847 state->compression_buffer)) != 0)
1848 goto out;
1849 DBG(debug("input: len after de-compress %zd",
1850 sshbuf_len(state->incoming_packet)));
1851 }
1852 /*
1853 * get packet type, implies consume.
1854 * return length of payload (without type field)
1855 */
1856 if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1857 goto out;
1858 if (ssh_packet_log_type(*typep))
1859 debug3("receive packet: type %u", *typep);
1860 if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1861 if ((r = sshpkt_disconnect(ssh,
1862 "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1863 (r = ssh_packet_write_wait(ssh)) != 0)
1864 return r;
1865 return SSH_ERR_PROTOCOL_ERROR;
1866 }
1867 if (*typep == SSH2_MSG_NEWKEYS)
1868 r = ssh_set_newkeys(ssh, MODE_IN);
1869 else if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1870 r = ssh_packet_enable_delayed_compress(ssh);
1871 else
1872 r = 0;
1873#ifdef PACKET_DEBUG
1874 fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1875 sshbuf_dump(state->incoming_packet, stderr);
1876#endif
1877 /* reset for next packet */
1878 state->packlen = 0;
1879
1880 /* do we need to rekey? */
1881 if (ssh_packet_need_rekeying(ssh, 0)) {
1882 debug3("%s: rekex triggered", __func__);
1883 if ((r = kex_start_rekex(ssh)) != 0)
1884 return r;
1885 }
1886 out:
1887 return r;
1888}
1889
1890int
1891ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1892{
1893 struct session_state *state = ssh->state;
1894 u_int reason, seqnr;
1895 int r;
1896 u_char *msg;
1897
1898 for (;;) {
1899 msg = NULL;
1900 if (compat20) {
1901 r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1902 if (r != 0)
1903 return r;
1904 if (*typep) {
1905 state->keep_alive_timeouts = 0;
1906 DBG(debug("received packet type %d", *typep));
1907 }
1908 switch (*typep) {
1909 case SSH2_MSG_IGNORE:
1910 debug3("Received SSH2_MSG_IGNORE");
1911 break;
1912 case SSH2_MSG_DEBUG:
1913 if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1914 (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1915 (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1916 free(msg);
1917 return r;
1918 }
1919 debug("Remote: %.900s", msg);
1920 free(msg);
1921 break;
1922 case SSH2_MSG_DISCONNECT:
1923 if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1924 (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1925 return r;
1926 /* Ignore normal client exit notifications */
1927 do_log2(ssh->state->server_side &&
1928 reason == SSH2_DISCONNECT_BY_APPLICATION ?
1929 SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1930 "Received disconnect from %s port %d:"
1931 "%u: %.400s", ssh_remote_ipaddr(ssh),
1932 ssh_remote_port(ssh), reason, msg);
1933 free(msg);
1934 return SSH_ERR_DISCONNECTED;
1935 case SSH2_MSG_UNIMPLEMENTED:
1936 if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1937 return r;
1938 debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1939 seqnr);
1940 break;
1941 default:
1942 return 0;
1943 }
1944 } else {
1945 r = ssh_packet_read_poll1(ssh, typep);
1946 switch (*typep) {
1947 case SSH_MSG_NONE:
1948 return SSH_MSG_NONE;
1949 case SSH_MSG_IGNORE:
1950 break;
1951 case SSH_MSG_DEBUG:
1952 if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1953 return r;
1954 debug("Remote: %.900s", msg);
1955 free(msg);
1956 break;
1957 case SSH_MSG_DISCONNECT:
1958 if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1959 return r;
1960 logit("Received disconnect from %s port %d: "
1961 "%.400s", ssh_remote_ipaddr(ssh),
1962 ssh_remote_port(ssh), msg);
1963 free(msg);
1964 return SSH_ERR_DISCONNECTED;
1965 default:
1966 DBG(debug("received packet type %d", *typep));
1967 return 0;
1968 }
1969 }
1970 }
1971}
1972
1973/*
1974 * Buffers the given amount of input characters. This is intended to be used
1975 * together with packet_read_poll.
1976 */
1977
1978int
1979ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1980{
1981 struct session_state *state = ssh->state;
1982 int r;
1983
1984 if (state->packet_discard) {
1985 state->keep_alive_timeouts = 0; /* ?? */
1986 if (len >= state->packet_discard) {
1987 if ((r = ssh_packet_stop_discard(ssh)) != 0)
1988 return r;
1989 }
1990 state->packet_discard -= len;
1991 return 0;
1992 }
1993 if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1994 return r;
1995
1996 return 0;
1997}
1998
1999int
2000ssh_packet_remaining(struct ssh *ssh)
2001{
2002 return sshbuf_len(ssh->state->incoming_packet);
2003}
2004
2005/*
2006 * Sends a diagnostic message from the server to the client. This message
2007 * can be sent at any time (but not while constructing another message). The
2008 * message is printed immediately, but only if the client is being executed
2009 * in verbose mode. These messages are primarily intended to ease debugging
2010 * authentication problems. The length of the formatted message must not
2011 * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
2012 */
2013void
2014ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
2015{
2016 char buf[1024];
2017 va_list args;
2018 int r;
2019
2020 if (compat20 && (ssh->compat & SSH_BUG_DEBUG))
2021 return;
2022
2023 va_start(args, fmt);
2024 vsnprintf(buf, sizeof(buf), fmt, args);
2025 va_end(args);
2026
2027 if (compat20) {
2028 if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
2029 (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
2030 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2031 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2032 (r = sshpkt_send(ssh)) != 0)
2033 fatal("%s: %s", __func__, ssh_err(r));
2034 } else {
2035 if ((r = sshpkt_start(ssh, SSH_MSG_DEBUG)) != 0 ||
2036 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2037 (r = sshpkt_send(ssh)) != 0)
2038 fatal("%s: %s", __func__, ssh_err(r));
2039 }
2040 if ((r = ssh_packet_write_wait(ssh)) != 0)
2041 fatal("%s: %s", __func__, ssh_err(r));
2042}
2043
2044/*
2045 * Pretty-print connection-terminating errors and exit.
2046 */
2047void
2048sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
2049{
2050 switch (r) {
2051 case SSH_ERR_CONN_CLOSED:
2052 logit("Connection closed by %.200s port %d",
2053 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
2054 cleanup_exit(255);
2055 case SSH_ERR_CONN_TIMEOUT:
2056 logit("Connection %s %.200s port %d timed out",
2057 ssh->state->server_side ? "from" : "to",
2058 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
2059 cleanup_exit(255);
2060 case SSH_ERR_DISCONNECTED:
2061 logit("Disconnected from %.200s port %d",
2062 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
2063 cleanup_exit(255);
2064 case SSH_ERR_SYSTEM_ERROR:
2065 if (errno == ECONNRESET) {
2066 logit("Connection reset by %.200s port %d",
2067 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
2068 cleanup_exit(255);
2069 }
2070 /* FALLTHROUGH */
2071 case SSH_ERR_NO_CIPHER_ALG_MATCH:
2072 case SSH_ERR_NO_MAC_ALG_MATCH:
2073 case SSH_ERR_NO_COMPRESS_ALG_MATCH:
2074 case SSH_ERR_NO_KEX_ALG_MATCH:
2075 case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
2076 if (ssh && ssh->kex && ssh->kex->failed_choice) {
| 89
90#ifdef PACKET_DEBUG
91#define DBG(x) x
92#else
93#define DBG(x)
94#endif
95
96#define PACKET_MAX_SIZE (256 * 1024)
97
98struct packet_state {
99 u_int32_t seqnr;
100 u_int32_t packets;
101 u_int64_t blocks;
102 u_int64_t bytes;
103};
104
105struct packet {
106 TAILQ_ENTRY(packet) next;
107 u_char type;
108 struct sshbuf *payload;
109};
110
111struct session_state {
112 /*
113 * This variable contains the file descriptors used for
114 * communicating with the other side. connection_in is used for
115 * reading; connection_out for writing. These can be the same
116 * descriptor, in which case it is assumed to be a socket.
117 */
118 int connection_in;
119 int connection_out;
120
121 /* Protocol flags for the remote side. */
122 u_int remote_protocol_flags;
123
124 /* Encryption context for receiving data. Only used for decryption. */
125 struct sshcipher_ctx receive_context;
126
127 /* Encryption context for sending data. Only used for encryption. */
128 struct sshcipher_ctx send_context;
129
130 /* Buffer for raw input data from the socket. */
131 struct sshbuf *input;
132
133 /* Buffer for raw output data going to the socket. */
134 struct sshbuf *output;
135
136 /* Buffer for the partial outgoing packet being constructed. */
137 struct sshbuf *outgoing_packet;
138
139 /* Buffer for the incoming packet currently being processed. */
140 struct sshbuf *incoming_packet;
141
142 /* Scratch buffer for packet compression/decompression. */
143 struct sshbuf *compression_buffer;
144
145 /* Incoming/outgoing compression dictionaries */
146 z_stream compression_in_stream;
147 z_stream compression_out_stream;
148 int compression_in_started;
149 int compression_out_started;
150 int compression_in_failures;
151 int compression_out_failures;
152
153 /*
154 * Flag indicating whether packet compression/decompression is
155 * enabled.
156 */
157 int packet_compression;
158
159 /* default maximum packet size */
160 u_int max_packet_size;
161
162 /* Flag indicating whether this module has been initialized. */
163 int initialized;
164
165 /* Set to true if the connection is interactive. */
166 int interactive_mode;
167
168 /* Set to true if we are the server side. */
169 int server_side;
170
171 /* Set to true if we are authenticated. */
172 int after_authentication;
173
174 int keep_alive_timeouts;
175
176 /* The maximum time that we will wait to send or receive a packet */
177 int packet_timeout_ms;
178
179 /* Session key information for Encryption and MAC */
180 struct newkeys *newkeys[MODE_MAX];
181 struct packet_state p_read, p_send;
182
183 /* Volume-based rekeying */
184 u_int64_t max_blocks_in, max_blocks_out, rekey_limit;
185
186 /* Time-based rekeying */
187 u_int32_t rekey_interval; /* how often in seconds */
188 time_t rekey_time; /* time of last rekeying */
189
190 /* Session key for protocol v1 */
191 u_char ssh1_key[SSH_SESSION_KEY_LENGTH];
192 u_int ssh1_keylen;
193
194 /* roundup current message to extra_pad bytes */
195 u_char extra_pad;
196
197 /* XXX discard incoming data after MAC error */
198 u_int packet_discard;
199 struct sshmac *packet_discard_mac;
200
201 /* Used in packet_read_poll2() */
202 u_int packlen;
203
204 /* Used in packet_send2 */
205 int rekeying;
206
207 /* Used in packet_set_interactive */
208 int set_interactive_called;
209
210 /* Used in packet_set_maxsize */
211 int set_maxsize_called;
212
213 /* One-off warning about weak ciphers */
214 int cipher_warning_done;
215
216 /* SSH1 CRC compensation attack detector */
217 struct deattack_ctx deattack;
218
219 TAILQ_HEAD(, packet) outgoing;
220};
221
222struct ssh *
223ssh_alloc_session_state(void)
224{
225 struct ssh *ssh = NULL;
226 struct session_state *state = NULL;
227
228 if ((ssh = calloc(1, sizeof(*ssh))) == NULL ||
229 (state = calloc(1, sizeof(*state))) == NULL ||
230 (state->input = sshbuf_new()) == NULL ||
231 (state->output = sshbuf_new()) == NULL ||
232 (state->outgoing_packet = sshbuf_new()) == NULL ||
233 (state->incoming_packet = sshbuf_new()) == NULL)
234 goto fail;
235 TAILQ_INIT(&state->outgoing);
236 TAILQ_INIT(&ssh->private_keys);
237 TAILQ_INIT(&ssh->public_keys);
238 state->connection_in = -1;
239 state->connection_out = -1;
240 state->max_packet_size = 32768;
241 state->packet_timeout_ms = -1;
242 state->p_send.packets = state->p_read.packets = 0;
243 state->initialized = 1;
244 /*
245 * ssh_packet_send2() needs to queue packets until
246 * we've done the initial key exchange.
247 */
248 state->rekeying = 1;
249 ssh->state = state;
250 return ssh;
251 fail:
252 if (state) {
253 sshbuf_free(state->input);
254 sshbuf_free(state->output);
255 sshbuf_free(state->incoming_packet);
256 sshbuf_free(state->outgoing_packet);
257 free(state);
258 }
259 free(ssh);
260 return NULL;
261}
262
263/* Returns nonzero if rekeying is in progress */
264int
265ssh_packet_is_rekeying(struct ssh *ssh)
266{
267 return compat20 &&
268 (ssh->state->rekeying || (ssh->kex != NULL && ssh->kex->done == 0));
269}
270
271/*
272 * Sets the descriptors used for communication. Disables encryption until
273 * packet_set_encryption_key is called.
274 */
275struct ssh *
276ssh_packet_set_connection(struct ssh *ssh, int fd_in, int fd_out)
277{
278 struct session_state *state;
279 const struct sshcipher *none = cipher_by_name("none");
280 int r;
281
282 if (none == NULL) {
283 error("%s: cannot load cipher 'none'", __func__);
284 return NULL;
285 }
286 if (ssh == NULL)
287 ssh = ssh_alloc_session_state();
288 if (ssh == NULL) {
289 error("%s: cound not allocate state", __func__);
290 return NULL;
291 }
292 state = ssh->state;
293 state->connection_in = fd_in;
294 state->connection_out = fd_out;
295 if ((r = cipher_init(&state->send_context, none,
296 (const u_char *)"", 0, NULL, 0, CIPHER_ENCRYPT)) != 0 ||
297 (r = cipher_init(&state->receive_context, none,
298 (const u_char *)"", 0, NULL, 0, CIPHER_DECRYPT)) != 0) {
299 error("%s: cipher_init failed: %s", __func__, ssh_err(r));
300 free(ssh);
301 return NULL;
302 }
303 state->newkeys[MODE_IN] = state->newkeys[MODE_OUT] = NULL;
304 deattack_init(&state->deattack);
305 /*
306 * Cache the IP address of the remote connection for use in error
307 * messages that might be generated after the connection has closed.
308 */
309 (void)ssh_remote_ipaddr(ssh);
310 return ssh;
311}
312
313void
314ssh_packet_set_timeout(struct ssh *ssh, int timeout, int count)
315{
316 struct session_state *state = ssh->state;
317
318 if (timeout <= 0 || count <= 0) {
319 state->packet_timeout_ms = -1;
320 return;
321 }
322 if ((INT_MAX / 1000) / count < timeout)
323 state->packet_timeout_ms = INT_MAX;
324 else
325 state->packet_timeout_ms = timeout * count * 1000;
326}
327
328int
329ssh_packet_stop_discard(struct ssh *ssh)
330{
331 struct session_state *state = ssh->state;
332 int r;
333
334 if (state->packet_discard_mac) {
335 char buf[1024];
336
337 memset(buf, 'a', sizeof(buf));
338 while (sshbuf_len(state->incoming_packet) <
339 PACKET_MAX_SIZE)
340 if ((r = sshbuf_put(state->incoming_packet, buf,
341 sizeof(buf))) != 0)
342 return r;
343 (void) mac_compute(state->packet_discard_mac,
344 state->p_read.seqnr,
345 sshbuf_ptr(state->incoming_packet), PACKET_MAX_SIZE,
346 NULL, 0);
347 }
348 logit("Finished discarding for %.200s port %d",
349 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
350 return SSH_ERR_MAC_INVALID;
351}
352
353static int
354ssh_packet_start_discard(struct ssh *ssh, struct sshenc *enc,
355 struct sshmac *mac, u_int packet_length, u_int discard)
356{
357 struct session_state *state = ssh->state;
358 int r;
359
360 if (enc == NULL || !cipher_is_cbc(enc->cipher) || (mac && mac->etm)) {
361 if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
362 return r;
363 return SSH_ERR_MAC_INVALID;
364 }
365 if (packet_length != PACKET_MAX_SIZE && mac && mac->enabled)
366 state->packet_discard_mac = mac;
367 if (sshbuf_len(state->input) >= discard &&
368 (r = ssh_packet_stop_discard(ssh)) != 0)
369 return r;
370 state->packet_discard = discard - sshbuf_len(state->input);
371 return 0;
372}
373
374/* Returns 1 if remote host is connected via socket, 0 if not. */
375
376int
377ssh_packet_connection_is_on_socket(struct ssh *ssh)
378{
379 struct session_state *state = ssh->state;
380 struct sockaddr_storage from, to;
381 socklen_t fromlen, tolen;
382
383 /* filedescriptors in and out are the same, so it's a socket */
384 if (state->connection_in == state->connection_out)
385 return 1;
386 fromlen = sizeof(from);
387 memset(&from, 0, sizeof(from));
388 if (getpeername(state->connection_in, (struct sockaddr *)&from,
389 &fromlen) < 0)
390 return 0;
391 tolen = sizeof(to);
392 memset(&to, 0, sizeof(to));
393 if (getpeername(state->connection_out, (struct sockaddr *)&to,
394 &tolen) < 0)
395 return 0;
396 if (fromlen != tolen || memcmp(&from, &to, fromlen) != 0)
397 return 0;
398 if (from.ss_family != AF_INET && from.ss_family != AF_INET6)
399 return 0;
400 return 1;
401}
402
403void
404ssh_packet_get_bytes(struct ssh *ssh, u_int64_t *ibytes, u_int64_t *obytes)
405{
406 if (ibytes)
407 *ibytes = ssh->state->p_read.bytes;
408 if (obytes)
409 *obytes = ssh->state->p_send.bytes;
410}
411
412int
413ssh_packet_connection_af(struct ssh *ssh)
414{
415 struct sockaddr_storage to;
416 socklen_t tolen = sizeof(to);
417
418 memset(&to, 0, sizeof(to));
419 if (getsockname(ssh->state->connection_out, (struct sockaddr *)&to,
420 &tolen) < 0)
421 return 0;
422#ifdef IPV4_IN_IPV6
423 if (to.ss_family == AF_INET6 &&
424 IN6_IS_ADDR_V4MAPPED(&((struct sockaddr_in6 *)&to)->sin6_addr))
425 return AF_INET;
426#endif
427 return to.ss_family;
428}
429
430/* Sets the connection into non-blocking mode. */
431
432void
433ssh_packet_set_nonblocking(struct ssh *ssh)
434{
435 /* Set the socket into non-blocking mode. */
436 set_nonblock(ssh->state->connection_in);
437
438 if (ssh->state->connection_out != ssh->state->connection_in)
439 set_nonblock(ssh->state->connection_out);
440}
441
442/* Returns the socket used for reading. */
443
444int
445ssh_packet_get_connection_in(struct ssh *ssh)
446{
447 return ssh->state->connection_in;
448}
449
450/* Returns the descriptor used for writing. */
451
452int
453ssh_packet_get_connection_out(struct ssh *ssh)
454{
455 return ssh->state->connection_out;
456}
457
458/*
459 * Returns the IP-address of the remote host as a string. The returned
460 * string must not be freed.
461 */
462
463const char *
464ssh_remote_ipaddr(struct ssh *ssh)
465{
466 const int sock = ssh->state->connection_in;
467
468 /* Check whether we have cached the ipaddr. */
469 if (ssh->remote_ipaddr == NULL) {
470 if (ssh_packet_connection_is_on_socket(ssh)) {
471 ssh->remote_ipaddr = get_peer_ipaddr(sock);
472 ssh->remote_port = get_sock_port(sock, 0);
473 } else {
474 ssh->remote_ipaddr = strdup("UNKNOWN");
475 ssh->remote_port = 0;
476 }
477 }
478 return ssh->remote_ipaddr;
479}
480
481/* Returns the port number of the remote host. */
482
483int
484ssh_remote_port(struct ssh *ssh)
485{
486 (void)ssh_remote_ipaddr(ssh); /* Will lookup and cache. */
487 return ssh->remote_port;
488}
489
490/* Closes the connection and clears and frees internal data structures. */
491
492void
493ssh_packet_close(struct ssh *ssh)
494{
495 struct session_state *state = ssh->state;
496 int r;
497 u_int mode;
498
499 if (!state->initialized)
500 return;
501 state->initialized = 0;
502 if (state->connection_in == state->connection_out) {
503 shutdown(state->connection_out, SHUT_RDWR);
504 close(state->connection_out);
505 } else {
506 close(state->connection_in);
507 close(state->connection_out);
508 }
509 sshbuf_free(state->input);
510 sshbuf_free(state->output);
511 sshbuf_free(state->outgoing_packet);
512 sshbuf_free(state->incoming_packet);
513 for (mode = 0; mode < MODE_MAX; mode++)
514 kex_free_newkeys(state->newkeys[mode]);
515 if (state->compression_buffer) {
516 sshbuf_free(state->compression_buffer);
517 if (state->compression_out_started) {
518 z_streamp stream = &state->compression_out_stream;
519 debug("compress outgoing: "
520 "raw data %llu, compressed %llu, factor %.2f",
521 (unsigned long long)stream->total_in,
522 (unsigned long long)stream->total_out,
523 stream->total_in == 0 ? 0.0 :
524 (double) stream->total_out / stream->total_in);
525 if (state->compression_out_failures == 0)
526 deflateEnd(stream);
527 }
528 if (state->compression_in_started) {
529 z_streamp stream = &state->compression_out_stream;
530 debug("compress incoming: "
531 "raw data %llu, compressed %llu, factor %.2f",
532 (unsigned long long)stream->total_out,
533 (unsigned long long)stream->total_in,
534 stream->total_out == 0 ? 0.0 :
535 (double) stream->total_in / stream->total_out);
536 if (state->compression_in_failures == 0)
537 inflateEnd(stream);
538 }
539 }
540 if ((r = cipher_cleanup(&state->send_context)) != 0)
541 error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
542 if ((r = cipher_cleanup(&state->receive_context)) != 0)
543 error("%s: cipher_cleanup failed: %s", __func__, ssh_err(r));
544 free(ssh->remote_ipaddr);
545 ssh->remote_ipaddr = NULL;
546 free(ssh->state);
547 ssh->state = NULL;
548}
549
550/* Sets remote side protocol flags. */
551
552void
553ssh_packet_set_protocol_flags(struct ssh *ssh, u_int protocol_flags)
554{
555 ssh->state->remote_protocol_flags = protocol_flags;
556}
557
558/* Returns the remote protocol flags set earlier by the above function. */
559
560u_int
561ssh_packet_get_protocol_flags(struct ssh *ssh)
562{
563 return ssh->state->remote_protocol_flags;
564}
565
566/*
567 * Starts packet compression from the next packet on in both directions.
568 * Level is compression level 1 (fastest) - 9 (slow, best) as in gzip.
569 */
570
571static int
572ssh_packet_init_compression(struct ssh *ssh)
573{
574 if (!ssh->state->compression_buffer &&
575 ((ssh->state->compression_buffer = sshbuf_new()) == NULL))
576 return SSH_ERR_ALLOC_FAIL;
577 return 0;
578}
579
580static int
581start_compression_out(struct ssh *ssh, int level)
582{
583 if (level < 1 || level > 9)
584 return SSH_ERR_INVALID_ARGUMENT;
585 debug("Enabling compression at level %d.", level);
586 if (ssh->state->compression_out_started == 1)
587 deflateEnd(&ssh->state->compression_out_stream);
588 switch (deflateInit(&ssh->state->compression_out_stream, level)) {
589 case Z_OK:
590 ssh->state->compression_out_started = 1;
591 break;
592 case Z_MEM_ERROR:
593 return SSH_ERR_ALLOC_FAIL;
594 default:
595 return SSH_ERR_INTERNAL_ERROR;
596 }
597 return 0;
598}
599
600static int
601start_compression_in(struct ssh *ssh)
602{
603 if (ssh->state->compression_in_started == 1)
604 inflateEnd(&ssh->state->compression_in_stream);
605 switch (inflateInit(&ssh->state->compression_in_stream)) {
606 case Z_OK:
607 ssh->state->compression_in_started = 1;
608 break;
609 case Z_MEM_ERROR:
610 return SSH_ERR_ALLOC_FAIL;
611 default:
612 return SSH_ERR_INTERNAL_ERROR;
613 }
614 return 0;
615}
616
617int
618ssh_packet_start_compression(struct ssh *ssh, int level)
619{
620 int r;
621
622 if (ssh->state->packet_compression && !compat20)
623 return SSH_ERR_INTERNAL_ERROR;
624 ssh->state->packet_compression = 1;
625 if ((r = ssh_packet_init_compression(ssh)) != 0 ||
626 (r = start_compression_in(ssh)) != 0 ||
627 (r = start_compression_out(ssh, level)) != 0)
628 return r;
629 return 0;
630}
631
632/* XXX remove need for separate compression buffer */
633static int
634compress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
635{
636 u_char buf[4096];
637 int r, status;
638
639 if (ssh->state->compression_out_started != 1)
640 return SSH_ERR_INTERNAL_ERROR;
641
642 /* This case is not handled below. */
643 if (sshbuf_len(in) == 0)
644 return 0;
645
646 /* Input is the contents of the input buffer. */
647 if ((ssh->state->compression_out_stream.next_in =
648 sshbuf_mutable_ptr(in)) == NULL)
649 return SSH_ERR_INTERNAL_ERROR;
650 ssh->state->compression_out_stream.avail_in = sshbuf_len(in);
651
652 /* Loop compressing until deflate() returns with avail_out != 0. */
653 do {
654 /* Set up fixed-size output buffer. */
655 ssh->state->compression_out_stream.next_out = buf;
656 ssh->state->compression_out_stream.avail_out = sizeof(buf);
657
658 /* Compress as much data into the buffer as possible. */
659 status = deflate(&ssh->state->compression_out_stream,
660 Z_PARTIAL_FLUSH);
661 switch (status) {
662 case Z_MEM_ERROR:
663 return SSH_ERR_ALLOC_FAIL;
664 case Z_OK:
665 /* Append compressed data to output_buffer. */
666 if ((r = sshbuf_put(out, buf, sizeof(buf) -
667 ssh->state->compression_out_stream.avail_out)) != 0)
668 return r;
669 break;
670 case Z_STREAM_ERROR:
671 default:
672 ssh->state->compression_out_failures++;
673 return SSH_ERR_INVALID_FORMAT;
674 }
675 } while (ssh->state->compression_out_stream.avail_out == 0);
676 return 0;
677}
678
679static int
680uncompress_buffer(struct ssh *ssh, struct sshbuf *in, struct sshbuf *out)
681{
682 u_char buf[4096];
683 int r, status;
684
685 if (ssh->state->compression_in_started != 1)
686 return SSH_ERR_INTERNAL_ERROR;
687
688 if ((ssh->state->compression_in_stream.next_in =
689 sshbuf_mutable_ptr(in)) == NULL)
690 return SSH_ERR_INTERNAL_ERROR;
691 ssh->state->compression_in_stream.avail_in = sshbuf_len(in);
692
693 for (;;) {
694 /* Set up fixed-size output buffer. */
695 ssh->state->compression_in_stream.next_out = buf;
696 ssh->state->compression_in_stream.avail_out = sizeof(buf);
697
698 status = inflate(&ssh->state->compression_in_stream,
699 Z_PARTIAL_FLUSH);
700 switch (status) {
701 case Z_OK:
702 if ((r = sshbuf_put(out, buf, sizeof(buf) -
703 ssh->state->compression_in_stream.avail_out)) != 0)
704 return r;
705 break;
706 case Z_BUF_ERROR:
707 /*
708 * Comments in zlib.h say that we should keep calling
709 * inflate() until we get an error. This appears to
710 * be the error that we get.
711 */
712 return 0;
713 case Z_DATA_ERROR:
714 return SSH_ERR_INVALID_FORMAT;
715 case Z_MEM_ERROR:
716 return SSH_ERR_ALLOC_FAIL;
717 case Z_STREAM_ERROR:
718 default:
719 ssh->state->compression_in_failures++;
720 return SSH_ERR_INTERNAL_ERROR;
721 }
722 }
723 /* NOTREACHED */
724}
725
726/* Serialise compression state into a blob for privsep */
727static int
728ssh_packet_get_compress_state(struct sshbuf *m, struct ssh *ssh)
729{
730 struct session_state *state = ssh->state;
731 struct sshbuf *b;
732 int r;
733
734 if ((b = sshbuf_new()) == NULL)
735 return SSH_ERR_ALLOC_FAIL;
736 if (state->compression_in_started) {
737 if ((r = sshbuf_put_string(b, &state->compression_in_stream,
738 sizeof(state->compression_in_stream))) != 0)
739 goto out;
740 } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
741 goto out;
742 if (state->compression_out_started) {
743 if ((r = sshbuf_put_string(b, &state->compression_out_stream,
744 sizeof(state->compression_out_stream))) != 0)
745 goto out;
746 } else if ((r = sshbuf_put_string(b, NULL, 0)) != 0)
747 goto out;
748 r = sshbuf_put_stringb(m, b);
749 out:
750 sshbuf_free(b);
751 return r;
752}
753
754/* Deserialise compression state from a blob for privsep */
755static int
756ssh_packet_set_compress_state(struct ssh *ssh, struct sshbuf *m)
757{
758 struct session_state *state = ssh->state;
759 struct sshbuf *b = NULL;
760 int r;
761 const u_char *inblob, *outblob;
762 size_t inl, outl;
763
764 if ((r = sshbuf_froms(m, &b)) != 0)
765 goto out;
766 if ((r = sshbuf_get_string_direct(b, &inblob, &inl)) != 0 ||
767 (r = sshbuf_get_string_direct(b, &outblob, &outl)) != 0)
768 goto out;
769 if (inl == 0)
770 state->compression_in_started = 0;
771 else if (inl != sizeof(state->compression_in_stream)) {
772 r = SSH_ERR_INTERNAL_ERROR;
773 goto out;
774 } else {
775 state->compression_in_started = 1;
776 memcpy(&state->compression_in_stream, inblob, inl);
777 }
778 if (outl == 0)
779 state->compression_out_started = 0;
780 else if (outl != sizeof(state->compression_out_stream)) {
781 r = SSH_ERR_INTERNAL_ERROR;
782 goto out;
783 } else {
784 state->compression_out_started = 1;
785 memcpy(&state->compression_out_stream, outblob, outl);
786 }
787 r = 0;
788 out:
789 sshbuf_free(b);
790 return r;
791}
792
793void
794ssh_packet_set_compress_hooks(struct ssh *ssh, void *ctx,
795 void *(*allocfunc)(void *, u_int, u_int),
796 void (*freefunc)(void *, void *))
797{
798 ssh->state->compression_out_stream.zalloc = (alloc_func)allocfunc;
799 ssh->state->compression_out_stream.zfree = (free_func)freefunc;
800 ssh->state->compression_out_stream.opaque = ctx;
801 ssh->state->compression_in_stream.zalloc = (alloc_func)allocfunc;
802 ssh->state->compression_in_stream.zfree = (free_func)freefunc;
803 ssh->state->compression_in_stream.opaque = ctx;
804}
805
806/*
807 * Causes any further packets to be encrypted using the given key. The same
808 * key is used for both sending and reception. However, both directions are
809 * encrypted independently of each other.
810 */
811
812void
813ssh_packet_set_encryption_key(struct ssh *ssh, const u_char *key, u_int keylen, int number)
814{
815#ifndef WITH_SSH1
816 fatal("no SSH protocol 1 support");
817#else /* WITH_SSH1 */
818 struct session_state *state = ssh->state;
819 const struct sshcipher *cipher = cipher_by_number(number);
820 int r;
821 const char *wmsg;
822
823 if (cipher == NULL)
824 fatal("%s: unknown cipher number %d", __func__, number);
825 if (keylen < 20)
826 fatal("%s: keylen too small: %d", __func__, keylen);
827 if (keylen > SSH_SESSION_KEY_LENGTH)
828 fatal("%s: keylen too big: %d", __func__, keylen);
829 memcpy(state->ssh1_key, key, keylen);
830 state->ssh1_keylen = keylen;
831 if ((r = cipher_init(&state->send_context, cipher, key, keylen,
832 NULL, 0, CIPHER_ENCRYPT)) != 0 ||
833 (r = cipher_init(&state->receive_context, cipher, key, keylen,
834 NULL, 0, CIPHER_DECRYPT) != 0))
835 fatal("%s: cipher_init failed: %s", __func__, ssh_err(r));
836 if (!state->cipher_warning_done &&
837 ((wmsg = cipher_warning_message(&state->send_context)) != NULL ||
838 (wmsg = cipher_warning_message(&state->send_context)) != NULL)) {
839 error("Warning: %s", wmsg);
840 state->cipher_warning_done = 1;
841 }
842#endif /* WITH_SSH1 */
843}
844
845/*
846 * Finalizes and sends the packet. If the encryption key has been set,
847 * encrypts the packet before sending.
848 */
849
850int
851ssh_packet_send1(struct ssh *ssh)
852{
853 struct session_state *state = ssh->state;
854 u_char buf[8], *cp;
855 int r, padding, len;
856 u_int checksum;
857
858 /*
859 * If using packet compression, compress the payload of the outgoing
860 * packet.
861 */
862 if (state->packet_compression) {
863 sshbuf_reset(state->compression_buffer);
864 /* Skip padding. */
865 if ((r = sshbuf_consume(state->outgoing_packet, 8)) != 0)
866 goto out;
867 /* padding */
868 if ((r = sshbuf_put(state->compression_buffer,
869 "\0\0\0\0\0\0\0\0", 8)) != 0)
870 goto out;
871 if ((r = compress_buffer(ssh, state->outgoing_packet,
872 state->compression_buffer)) != 0)
873 goto out;
874 sshbuf_reset(state->outgoing_packet);
875 if ((r = sshbuf_putb(state->outgoing_packet,
876 state->compression_buffer)) != 0)
877 goto out;
878 }
879 /* Compute packet length without padding (add checksum, remove padding). */
880 len = sshbuf_len(state->outgoing_packet) + 4 - 8;
881
882 /* Insert padding. Initialized to zero in packet_start1() */
883 padding = 8 - len % 8;
884 if (!state->send_context.plaintext) {
885 cp = sshbuf_mutable_ptr(state->outgoing_packet);
886 if (cp == NULL) {
887 r = SSH_ERR_INTERNAL_ERROR;
888 goto out;
889 }
890 arc4random_buf(cp + 8 - padding, padding);
891 }
892 if ((r = sshbuf_consume(state->outgoing_packet, 8 - padding)) != 0)
893 goto out;
894
895 /* Add check bytes. */
896 checksum = ssh_crc32(sshbuf_ptr(state->outgoing_packet),
897 sshbuf_len(state->outgoing_packet));
898 POKE_U32(buf, checksum);
899 if ((r = sshbuf_put(state->outgoing_packet, buf, 4)) != 0)
900 goto out;
901
902#ifdef PACKET_DEBUG
903 fprintf(stderr, "packet_send plain: ");
904 sshbuf_dump(state->outgoing_packet, stderr);
905#endif
906
907 /* Append to output. */
908 POKE_U32(buf, len);
909 if ((r = sshbuf_put(state->output, buf, 4)) != 0)
910 goto out;
911 if ((r = sshbuf_reserve(state->output,
912 sshbuf_len(state->outgoing_packet), &cp)) != 0)
913 goto out;
914 if ((r = cipher_crypt(&state->send_context, 0, cp,
915 sshbuf_ptr(state->outgoing_packet),
916 sshbuf_len(state->outgoing_packet), 0, 0)) != 0)
917 goto out;
918
919#ifdef PACKET_DEBUG
920 fprintf(stderr, "encrypted: ");
921 sshbuf_dump(state->output, stderr);
922#endif
923 state->p_send.packets++;
924 state->p_send.bytes += len +
925 sshbuf_len(state->outgoing_packet);
926 sshbuf_reset(state->outgoing_packet);
927
928 /*
929 * Note that the packet is now only buffered in output. It won't be
930 * actually sent until ssh_packet_write_wait or ssh_packet_write_poll
931 * is called.
932 */
933 r = 0;
934 out:
935 return r;
936}
937
938int
939ssh_set_newkeys(struct ssh *ssh, int mode)
940{
941 struct session_state *state = ssh->state;
942 struct sshenc *enc;
943 struct sshmac *mac;
944 struct sshcomp *comp;
945 struct sshcipher_ctx *cc;
946 u_int64_t *max_blocks;
947 const char *wmsg;
948 int r, crypt_type;
949
950 debug2("set_newkeys: mode %d", mode);
951
952 if (mode == MODE_OUT) {
953 cc = &state->send_context;
954 crypt_type = CIPHER_ENCRYPT;
955 state->p_send.packets = state->p_send.blocks = 0;
956 max_blocks = &state->max_blocks_out;
957 } else {
958 cc = &state->receive_context;
959 crypt_type = CIPHER_DECRYPT;
960 state->p_read.packets = state->p_read.blocks = 0;
961 max_blocks = &state->max_blocks_in;
962 }
963 if (state->newkeys[mode] != NULL) {
964 debug("set_newkeys: rekeying, input %llu bytes %llu blocks, "
965 "output %llu bytes %llu blocks",
966 (unsigned long long)state->p_read.bytes,
967 (unsigned long long)state->p_read.blocks,
968 (unsigned long long)state->p_send.bytes,
969 (unsigned long long)state->p_send.blocks);
970 if ((r = cipher_cleanup(cc)) != 0)
971 return r;
972 enc = &state->newkeys[mode]->enc;
973 mac = &state->newkeys[mode]->mac;
974 comp = &state->newkeys[mode]->comp;
975 mac_clear(mac);
976 explicit_bzero(enc->iv, enc->iv_len);
977 explicit_bzero(enc->key, enc->key_len);
978 explicit_bzero(mac->key, mac->key_len);
979 free(enc->name);
980 free(enc->iv);
981 free(enc->key);
982 free(mac->name);
983 free(mac->key);
984 free(comp->name);
985 free(state->newkeys[mode]);
986 }
987 /* move newkeys from kex to state */
988 if ((state->newkeys[mode] = ssh->kex->newkeys[mode]) == NULL)
989 return SSH_ERR_INTERNAL_ERROR;
990 ssh->kex->newkeys[mode] = NULL;
991 enc = &state->newkeys[mode]->enc;
992 mac = &state->newkeys[mode]->mac;
993 comp = &state->newkeys[mode]->comp;
994 if (cipher_authlen(enc->cipher) == 0) {
995 if ((r = mac_init(mac)) != 0)
996 return r;
997 }
998 mac->enabled = 1;
999 DBG(debug("cipher_init_context: %d", mode));
1000 if ((r = cipher_init(cc, enc->cipher, enc->key, enc->key_len,
1001 enc->iv, enc->iv_len, crypt_type)) != 0)
1002 return r;
1003 if (!state->cipher_warning_done &&
1004 (wmsg = cipher_warning_message(cc)) != NULL) {
1005 error("Warning: %s", wmsg);
1006 state->cipher_warning_done = 1;
1007 }
1008 /* Deleting the keys does not gain extra security */
1009 /* explicit_bzero(enc->iv, enc->block_size);
1010 explicit_bzero(enc->key, enc->key_len);
1011 explicit_bzero(mac->key, mac->key_len); */
1012 if ((comp->type == COMP_ZLIB ||
1013 (comp->type == COMP_DELAYED &&
1014 state->after_authentication)) && comp->enabled == 0) {
1015 if ((r = ssh_packet_init_compression(ssh)) < 0)
1016 return r;
1017 if (mode == MODE_OUT) {
1018 if ((r = start_compression_out(ssh, 6)) != 0)
1019 return r;
1020 } else {
1021 if ((r = start_compression_in(ssh)) != 0)
1022 return r;
1023 }
1024 comp->enabled = 1;
1025 }
1026 /*
1027 * The 2^(blocksize*2) limit is too expensive for 3DES,
1028 * blowfish, etc, so enforce a 1GB limit for small blocksizes.
1029 */
1030 if (enc->block_size >= 16)
1031 *max_blocks = (u_int64_t)1 << (enc->block_size*2);
1032 else
1033 *max_blocks = ((u_int64_t)1 << 30) / enc->block_size;
1034 if (state->rekey_limit)
1035 *max_blocks = MIN(*max_blocks,
1036 state->rekey_limit / enc->block_size);
1037 debug("rekey after %llu blocks", (unsigned long long)*max_blocks);
1038 return 0;
1039}
1040
1041#define MAX_PACKETS (1U<<31)
1042static int
1043ssh_packet_need_rekeying(struct ssh *ssh, u_int outbound_packet_len)
1044{
1045 struct session_state *state = ssh->state;
1046 u_int32_t out_blocks;
1047
1048 /* XXX client can't cope with rekeying pre-auth */
1049 if (!state->after_authentication)
1050 return 0;
1051
1052 /* Haven't keyed yet or KEX in progress. */
1053 if (ssh->kex == NULL || ssh_packet_is_rekeying(ssh))
1054 return 0;
1055
1056 /* Peer can't rekey */
1057 if (ssh->compat & SSH_BUG_NOREKEY)
1058 return 0;
1059
1060 /*
1061 * Permit one packet in or out per rekey - this allows us to
1062 * make progress when rekey limits are very small.
1063 */
1064 if (state->p_send.packets == 0 && state->p_read.packets == 0)
1065 return 0;
1066
1067 /* Time-based rekeying */
1068 if (state->rekey_interval != 0 &&
1069 state->rekey_time + state->rekey_interval <= monotime())
1070 return 1;
1071
1072 /* Always rekey when MAX_PACKETS sent in either direction */
1073 if (state->p_send.packets > MAX_PACKETS ||
1074 state->p_read.packets > MAX_PACKETS)
1075 return 1;
1076
1077 /* Rekey after (cipher-specific) maxiumum blocks */
1078 out_blocks = roundup(outbound_packet_len,
1079 state->newkeys[MODE_OUT]->enc.block_size);
1080 return (state->max_blocks_out &&
1081 (state->p_send.blocks + out_blocks > state->max_blocks_out)) ||
1082 (state->max_blocks_in &&
1083 (state->p_read.blocks > state->max_blocks_in));
1084}
1085
1086/*
1087 * Delayed compression for SSH2 is enabled after authentication:
1088 * This happens on the server side after a SSH2_MSG_USERAUTH_SUCCESS is sent,
1089 * and on the client side after a SSH2_MSG_USERAUTH_SUCCESS is received.
1090 */
1091static int
1092ssh_packet_enable_delayed_compress(struct ssh *ssh)
1093{
1094 struct session_state *state = ssh->state;
1095 struct sshcomp *comp = NULL;
1096 int r, mode;
1097
1098 /*
1099 * Remember that we are past the authentication step, so rekeying
1100 * with COMP_DELAYED will turn on compression immediately.
1101 */
1102 state->after_authentication = 1;
1103 for (mode = 0; mode < MODE_MAX; mode++) {
1104 /* protocol error: USERAUTH_SUCCESS received before NEWKEYS */
1105 if (state->newkeys[mode] == NULL)
1106 continue;
1107 comp = &state->newkeys[mode]->comp;
1108 if (comp && !comp->enabled && comp->type == COMP_DELAYED) {
1109 if ((r = ssh_packet_init_compression(ssh)) != 0)
1110 return r;
1111 if (mode == MODE_OUT) {
1112 if ((r = start_compression_out(ssh, 6)) != 0)
1113 return r;
1114 } else {
1115 if ((r = start_compression_in(ssh)) != 0)
1116 return r;
1117 }
1118 comp->enabled = 1;
1119 }
1120 }
1121 return 0;
1122}
1123
1124/* Used to mute debug logging for noisy packet types */
1125static int
1126ssh_packet_log_type(u_char type)
1127{
1128 switch (type) {
1129 case SSH2_MSG_CHANNEL_DATA:
1130 case SSH2_MSG_CHANNEL_EXTENDED_DATA:
1131 case SSH2_MSG_CHANNEL_WINDOW_ADJUST:
1132 return 0;
1133 default:
1134 return 1;
1135 }
1136}
1137
1138/*
1139 * Finalize packet in SSH2 format (compress, mac, encrypt, enqueue)
1140 */
1141int
1142ssh_packet_send2_wrapped(struct ssh *ssh)
1143{
1144 struct session_state *state = ssh->state;
1145 u_char type, *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1146 u_char padlen, pad = 0;
1147 u_int authlen = 0, aadlen = 0;
1148 u_int len;
1149 struct sshenc *enc = NULL;
1150 struct sshmac *mac = NULL;
1151 struct sshcomp *comp = NULL;
1152 int r, block_size;
1153
1154 if (state->newkeys[MODE_OUT] != NULL) {
1155 enc = &state->newkeys[MODE_OUT]->enc;
1156 mac = &state->newkeys[MODE_OUT]->mac;
1157 comp = &state->newkeys[MODE_OUT]->comp;
1158 /* disable mac for authenticated encryption */
1159 if ((authlen = cipher_authlen(enc->cipher)) != 0)
1160 mac = NULL;
1161 }
1162 block_size = enc ? enc->block_size : 8;
1163 aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1164
1165 type = (sshbuf_ptr(state->outgoing_packet))[5];
1166 if (ssh_packet_log_type(type))
1167 debug3("send packet: type %u", type);
1168#ifdef PACKET_DEBUG
1169 fprintf(stderr, "plain: ");
1170 sshbuf_dump(state->outgoing_packet, stderr);
1171#endif
1172
1173 if (comp && comp->enabled) {
1174 len = sshbuf_len(state->outgoing_packet);
1175 /* skip header, compress only payload */
1176 if ((r = sshbuf_consume(state->outgoing_packet, 5)) != 0)
1177 goto out;
1178 sshbuf_reset(state->compression_buffer);
1179 if ((r = compress_buffer(ssh, state->outgoing_packet,
1180 state->compression_buffer)) != 0)
1181 goto out;
1182 sshbuf_reset(state->outgoing_packet);
1183 if ((r = sshbuf_put(state->outgoing_packet,
1184 "\0\0\0\0\0", 5)) != 0 ||
1185 (r = sshbuf_putb(state->outgoing_packet,
1186 state->compression_buffer)) != 0)
1187 goto out;
1188 DBG(debug("compression: raw %d compressed %zd", len,
1189 sshbuf_len(state->outgoing_packet)));
1190 }
1191
1192 /* sizeof (packet_len + pad_len + payload) */
1193 len = sshbuf_len(state->outgoing_packet);
1194
1195 /*
1196 * calc size of padding, alloc space, get random data,
1197 * minimum padding is 4 bytes
1198 */
1199 len -= aadlen; /* packet length is not encrypted for EtM modes */
1200 padlen = block_size - (len % block_size);
1201 if (padlen < 4)
1202 padlen += block_size;
1203 if (state->extra_pad) {
1204 /* will wrap if extra_pad+padlen > 255 */
1205 state->extra_pad =
1206 roundup(state->extra_pad, block_size);
1207 pad = state->extra_pad -
1208 ((len + padlen) % state->extra_pad);
1209 DBG(debug3("%s: adding %d (len %d padlen %d extra_pad %d)",
1210 __func__, pad, len, padlen, state->extra_pad));
1211 padlen += pad;
1212 state->extra_pad = 0;
1213 }
1214 if ((r = sshbuf_reserve(state->outgoing_packet, padlen, &cp)) != 0)
1215 goto out;
1216 if (enc && !state->send_context.plaintext) {
1217 /* random padding */
1218 arc4random_buf(cp, padlen);
1219 } else {
1220 /* clear padding */
1221 explicit_bzero(cp, padlen);
1222 }
1223 /* sizeof (packet_len + pad_len + payload + padding) */
1224 len = sshbuf_len(state->outgoing_packet);
1225 cp = sshbuf_mutable_ptr(state->outgoing_packet);
1226 if (cp == NULL) {
1227 r = SSH_ERR_INTERNAL_ERROR;
1228 goto out;
1229 }
1230 /* packet_length includes payload, padding and padding length field */
1231 POKE_U32(cp, len - 4);
1232 cp[4] = padlen;
1233 DBG(debug("send: len %d (includes padlen %d, aadlen %d)",
1234 len, padlen, aadlen));
1235
1236 /* compute MAC over seqnr and packet(length fields, payload, padding) */
1237 if (mac && mac->enabled && !mac->etm) {
1238 if ((r = mac_compute(mac, state->p_send.seqnr,
1239 sshbuf_ptr(state->outgoing_packet), len,
1240 macbuf, sizeof(macbuf))) != 0)
1241 goto out;
1242 DBG(debug("done calc MAC out #%d", state->p_send.seqnr));
1243 }
1244 /* encrypt packet and append to output buffer. */
1245 if ((r = sshbuf_reserve(state->output,
1246 sshbuf_len(state->outgoing_packet) + authlen, &cp)) != 0)
1247 goto out;
1248 if ((r = cipher_crypt(&state->send_context, state->p_send.seqnr, cp,
1249 sshbuf_ptr(state->outgoing_packet),
1250 len - aadlen, aadlen, authlen)) != 0)
1251 goto out;
1252 /* append unencrypted MAC */
1253 if (mac && mac->enabled) {
1254 if (mac->etm) {
1255 /* EtM: compute mac over aadlen + cipher text */
1256 if ((r = mac_compute(mac, state->p_send.seqnr,
1257 cp, len, macbuf, sizeof(macbuf))) != 0)
1258 goto out;
1259 DBG(debug("done calc MAC(EtM) out #%d",
1260 state->p_send.seqnr));
1261 }
1262 if ((r = sshbuf_put(state->output, macbuf, mac->mac_len)) != 0)
1263 goto out;
1264 }
1265#ifdef PACKET_DEBUG
1266 fprintf(stderr, "encrypted: ");
1267 sshbuf_dump(state->output, stderr);
1268#endif
1269 /* increment sequence number for outgoing packets */
1270 if (++state->p_send.seqnr == 0)
1271 logit("outgoing seqnr wraps around");
1272 if (++state->p_send.packets == 0)
1273 if (!(ssh->compat & SSH_BUG_NOREKEY))
1274 return SSH_ERR_NEED_REKEY;
1275 state->p_send.blocks += len / block_size;
1276 state->p_send.bytes += len;
1277 sshbuf_reset(state->outgoing_packet);
1278
1279 if (type == SSH2_MSG_NEWKEYS)
1280 r = ssh_set_newkeys(ssh, MODE_OUT);
1281 else if (type == SSH2_MSG_USERAUTH_SUCCESS && state->server_side)
1282 r = ssh_packet_enable_delayed_compress(ssh);
1283 else
1284 r = 0;
1285 out:
1286 return r;
1287}
1288
1289/* returns non-zero if the specified packet type is usec by KEX */
1290static int
1291ssh_packet_type_is_kex(u_char type)
1292{
1293 return
1294 type >= SSH2_MSG_TRANSPORT_MIN &&
1295 type <= SSH2_MSG_TRANSPORT_MAX &&
1296 type != SSH2_MSG_SERVICE_REQUEST &&
1297 type != SSH2_MSG_SERVICE_ACCEPT &&
1298 type != SSH2_MSG_EXT_INFO;
1299}
1300
1301int
1302ssh_packet_send2(struct ssh *ssh)
1303{
1304 struct session_state *state = ssh->state;
1305 struct packet *p;
1306 u_char type;
1307 int r, need_rekey;
1308
1309 if (sshbuf_len(state->outgoing_packet) < 6)
1310 return SSH_ERR_INTERNAL_ERROR;
1311 type = sshbuf_ptr(state->outgoing_packet)[5];
1312 need_rekey = !ssh_packet_type_is_kex(type) &&
1313 ssh_packet_need_rekeying(ssh, sshbuf_len(state->outgoing_packet));
1314
1315 /*
1316 * During rekeying we can only send key exchange messages.
1317 * Queue everything else.
1318 */
1319 if ((need_rekey || state->rekeying) && !ssh_packet_type_is_kex(type)) {
1320 if (need_rekey)
1321 debug3("%s: rekex triggered", __func__);
1322 debug("enqueue packet: %u", type);
1323 p = calloc(1, sizeof(*p));
1324 if (p == NULL)
1325 return SSH_ERR_ALLOC_FAIL;
1326 p->type = type;
1327 p->payload = state->outgoing_packet;
1328 TAILQ_INSERT_TAIL(&state->outgoing, p, next);
1329 state->outgoing_packet = sshbuf_new();
1330 if (state->outgoing_packet == NULL)
1331 return SSH_ERR_ALLOC_FAIL;
1332 if (need_rekey) {
1333 /*
1334 * This packet triggered a rekey, so send the
1335 * KEXINIT now.
1336 * NB. reenters this function via kex_start_rekex().
1337 */
1338 return kex_start_rekex(ssh);
1339 }
1340 return 0;
1341 }
1342
1343 /* rekeying starts with sending KEXINIT */
1344 if (type == SSH2_MSG_KEXINIT)
1345 state->rekeying = 1;
1346
1347 if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1348 return r;
1349
1350 /* after a NEWKEYS message we can send the complete queue */
1351 if (type == SSH2_MSG_NEWKEYS) {
1352 state->rekeying = 0;
1353 state->rekey_time = monotime();
1354 while ((p = TAILQ_FIRST(&state->outgoing))) {
1355 type = p->type;
1356 /*
1357 * If this packet triggers a rekex, then skip the
1358 * remaining packets in the queue for now.
1359 * NB. re-enters this function via kex_start_rekex.
1360 */
1361 if (ssh_packet_need_rekeying(ssh,
1362 sshbuf_len(p->payload))) {
1363 debug3("%s: queued packet triggered rekex",
1364 __func__);
1365 return kex_start_rekex(ssh);
1366 }
1367 debug("dequeue packet: %u", type);
1368 sshbuf_free(state->outgoing_packet);
1369 state->outgoing_packet = p->payload;
1370 TAILQ_REMOVE(&state->outgoing, p, next);
1371 memset(p, 0, sizeof(*p));
1372 free(p);
1373 if ((r = ssh_packet_send2_wrapped(ssh)) != 0)
1374 return r;
1375 }
1376 }
1377 return 0;
1378}
1379
1380/*
1381 * Waits until a packet has been received, and returns its type. Note that
1382 * no other data is processed until this returns, so this function should not
1383 * be used during the interactive session.
1384 */
1385
1386int
1387ssh_packet_read_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1388{
1389 struct session_state *state = ssh->state;
1390 int len, r, ms_remain;
1391 fd_set *setp;
1392 char buf[8192];
1393 struct timeval timeout, start, *timeoutp = NULL;
1394
1395 DBG(debug("packet_read()"));
1396
1397 setp = calloc(howmany(state->connection_in + 1,
1398 NFDBITS), sizeof(fd_mask));
1399 if (setp == NULL)
1400 return SSH_ERR_ALLOC_FAIL;
1401
1402 /*
1403 * Since we are blocking, ensure that all written packets have
1404 * been sent.
1405 */
1406 if ((r = ssh_packet_write_wait(ssh)) != 0)
1407 goto out;
1408
1409 /* Stay in the loop until we have received a complete packet. */
1410 for (;;) {
1411 /* Try to read a packet from the buffer. */
1412 r = ssh_packet_read_poll_seqnr(ssh, typep, seqnr_p);
1413 if (r != 0)
1414 break;
1415 if (!compat20 && (
1416 *typep == SSH_SMSG_SUCCESS
1417 || *typep == SSH_SMSG_FAILURE
1418 || *typep == SSH_CMSG_EOF
1419 || *typep == SSH_CMSG_EXIT_CONFIRMATION))
1420 if ((r = sshpkt_get_end(ssh)) != 0)
1421 break;
1422 /* If we got a packet, return it. */
1423 if (*typep != SSH_MSG_NONE)
1424 break;
1425 /*
1426 * Otherwise, wait for some data to arrive, add it to the
1427 * buffer, and try again.
1428 */
1429 memset(setp, 0, howmany(state->connection_in + 1,
1430 NFDBITS) * sizeof(fd_mask));
1431 FD_SET(state->connection_in, setp);
1432
1433 if (state->packet_timeout_ms > 0) {
1434 ms_remain = state->packet_timeout_ms;
1435 timeoutp = &timeout;
1436 }
1437 /* Wait for some data to arrive. */
1438 for (;;) {
1439 if (state->packet_timeout_ms != -1) {
1440 ms_to_timeval(&timeout, ms_remain);
1441 gettimeofday(&start, NULL);
1442 }
1443 if ((r = select(state->connection_in + 1, setp,
1444 NULL, NULL, timeoutp)) >= 0)
1445 break;
1446 if (errno != EAGAIN && errno != EINTR &&
1447 errno != EWOULDBLOCK)
1448 break;
1449 if (state->packet_timeout_ms == -1)
1450 continue;
1451 ms_subtract_diff(&start, &ms_remain);
1452 if (ms_remain <= 0) {
1453 r = 0;
1454 break;
1455 }
1456 }
1457 if (r == 0)
1458 return SSH_ERR_CONN_TIMEOUT;
1459 /* Read data from the socket. */
1460 len = read(state->connection_in, buf, sizeof(buf));
1461 if (len == 0) {
1462 r = SSH_ERR_CONN_CLOSED;
1463 goto out;
1464 }
1465 if (len < 0) {
1466 r = SSH_ERR_SYSTEM_ERROR;
1467 goto out;
1468 }
1469
1470 /* Append it to the buffer. */
1471 if ((r = ssh_packet_process_incoming(ssh, buf, len)) != 0)
1472 goto out;
1473 }
1474 out:
1475 free(setp);
1476 return r;
1477}
1478
1479int
1480ssh_packet_read(struct ssh *ssh)
1481{
1482 u_char type;
1483 int r;
1484
1485 if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1486 fatal("%s: %s", __func__, ssh_err(r));
1487 return type;
1488}
1489
1490/*
1491 * Waits until a packet has been received, verifies that its type matches
1492 * that given, and gives a fatal error and exits if there is a mismatch.
1493 */
1494
1495int
1496ssh_packet_read_expect(struct ssh *ssh, u_int expected_type)
1497{
1498 int r;
1499 u_char type;
1500
1501 if ((r = ssh_packet_read_seqnr(ssh, &type, NULL)) != 0)
1502 return r;
1503 if (type != expected_type) {
1504 if ((r = sshpkt_disconnect(ssh,
1505 "Protocol error: expected packet type %d, got %d",
1506 expected_type, type)) != 0)
1507 return r;
1508 return SSH_ERR_PROTOCOL_ERROR;
1509 }
1510 return 0;
1511}
1512
1513/* Checks if a full packet is available in the data received so far via
1514 * packet_process_incoming. If so, reads the packet; otherwise returns
1515 * SSH_MSG_NONE. This does not wait for data from the connection.
1516 *
1517 * SSH_MSG_DISCONNECT is handled specially here. Also,
1518 * SSH_MSG_IGNORE messages are skipped by this function and are never returned
1519 * to higher levels.
1520 */
1521
1522int
1523ssh_packet_read_poll1(struct ssh *ssh, u_char *typep)
1524{
1525 struct session_state *state = ssh->state;
1526 u_int len, padded_len;
1527 const char *emsg;
1528 const u_char *cp;
1529 u_char *p;
1530 u_int checksum, stored_checksum;
1531 int r;
1532
1533 *typep = SSH_MSG_NONE;
1534
1535 /* Check if input size is less than minimum packet size. */
1536 if (sshbuf_len(state->input) < 4 + 8)
1537 return 0;
1538 /* Get length of incoming packet. */
1539 len = PEEK_U32(sshbuf_ptr(state->input));
1540 if (len < 1 + 2 + 2 || len > 256 * 1024) {
1541 if ((r = sshpkt_disconnect(ssh, "Bad packet length %u",
1542 len)) != 0)
1543 return r;
1544 return SSH_ERR_CONN_CORRUPT;
1545 }
1546 padded_len = (len + 8) & ~7;
1547
1548 /* Check if the packet has been entirely received. */
1549 if (sshbuf_len(state->input) < 4 + padded_len)
1550 return 0;
1551
1552 /* The entire packet is in buffer. */
1553
1554 /* Consume packet length. */
1555 if ((r = sshbuf_consume(state->input, 4)) != 0)
1556 goto out;
1557
1558 /*
1559 * Cryptographic attack detector for ssh
1560 * (C)1998 CORE-SDI, Buenos Aires Argentina
1561 * Ariel Futoransky(futo@core-sdi.com)
1562 */
1563 if (!state->receive_context.plaintext) {
1564 emsg = NULL;
1565 switch (detect_attack(&state->deattack,
1566 sshbuf_ptr(state->input), padded_len)) {
1567 case DEATTACK_OK:
1568 break;
1569 case DEATTACK_DETECTED:
1570 emsg = "crc32 compensation attack detected";
1571 break;
1572 case DEATTACK_DOS_DETECTED:
1573 emsg = "deattack denial of service detected";
1574 break;
1575 default:
1576 emsg = "deattack error";
1577 break;
1578 }
1579 if (emsg != NULL) {
1580 error("%s", emsg);
1581 if ((r = sshpkt_disconnect(ssh, "%s", emsg)) != 0 ||
1582 (r = ssh_packet_write_wait(ssh)) != 0)
1583 return r;
1584 return SSH_ERR_CONN_CORRUPT;
1585 }
1586 }
1587
1588 /* Decrypt data to incoming_packet. */
1589 sshbuf_reset(state->incoming_packet);
1590 if ((r = sshbuf_reserve(state->incoming_packet, padded_len, &p)) != 0)
1591 goto out;
1592 if ((r = cipher_crypt(&state->receive_context, 0, p,
1593 sshbuf_ptr(state->input), padded_len, 0, 0)) != 0)
1594 goto out;
1595
1596 if ((r = sshbuf_consume(state->input, padded_len)) != 0)
1597 goto out;
1598
1599#ifdef PACKET_DEBUG
1600 fprintf(stderr, "read_poll plain: ");
1601 sshbuf_dump(state->incoming_packet, stderr);
1602#endif
1603
1604 /* Compute packet checksum. */
1605 checksum = ssh_crc32(sshbuf_ptr(state->incoming_packet),
1606 sshbuf_len(state->incoming_packet) - 4);
1607
1608 /* Skip padding. */
1609 if ((r = sshbuf_consume(state->incoming_packet, 8 - len % 8)) != 0)
1610 goto out;
1611
1612 /* Test check bytes. */
1613 if (len != sshbuf_len(state->incoming_packet)) {
1614 error("%s: len %d != sshbuf_len %zd", __func__,
1615 len, sshbuf_len(state->incoming_packet));
1616 if ((r = sshpkt_disconnect(ssh, "invalid packet length")) != 0 ||
1617 (r = ssh_packet_write_wait(ssh)) != 0)
1618 return r;
1619 return SSH_ERR_CONN_CORRUPT;
1620 }
1621
1622 cp = sshbuf_ptr(state->incoming_packet) + len - 4;
1623 stored_checksum = PEEK_U32(cp);
1624 if (checksum != stored_checksum) {
1625 error("Corrupted check bytes on input");
1626 if ((r = sshpkt_disconnect(ssh, "connection corrupted")) != 0 ||
1627 (r = ssh_packet_write_wait(ssh)) != 0)
1628 return r;
1629 return SSH_ERR_CONN_CORRUPT;
1630 }
1631 if ((r = sshbuf_consume_end(state->incoming_packet, 4)) < 0)
1632 goto out;
1633
1634 if (state->packet_compression) {
1635 sshbuf_reset(state->compression_buffer);
1636 if ((r = uncompress_buffer(ssh, state->incoming_packet,
1637 state->compression_buffer)) != 0)
1638 goto out;
1639 sshbuf_reset(state->incoming_packet);
1640 if ((r = sshbuf_putb(state->incoming_packet,
1641 state->compression_buffer)) != 0)
1642 goto out;
1643 }
1644 state->p_read.packets++;
1645 state->p_read.bytes += padded_len + 4;
1646 if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1647 goto out;
1648 if (*typep < SSH_MSG_MIN || *typep > SSH_MSG_MAX) {
1649 error("Invalid ssh1 packet type: %d", *typep);
1650 if ((r = sshpkt_disconnect(ssh, "invalid packet type")) != 0 ||
1651 (r = ssh_packet_write_wait(ssh)) != 0)
1652 return r;
1653 return SSH_ERR_PROTOCOL_ERROR;
1654 }
1655 r = 0;
1656 out:
1657 return r;
1658}
1659
1660int
1661ssh_packet_read_poll2(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1662{
1663 struct session_state *state = ssh->state;
1664 u_int padlen, need;
1665 u_char *cp, macbuf[SSH_DIGEST_MAX_LENGTH];
1666 u_int maclen, aadlen = 0, authlen = 0, block_size;
1667 struct sshenc *enc = NULL;
1668 struct sshmac *mac = NULL;
1669 struct sshcomp *comp = NULL;
1670 int r;
1671
1672 *typep = SSH_MSG_NONE;
1673
1674 if (state->packet_discard)
1675 return 0;
1676
1677 if (state->newkeys[MODE_IN] != NULL) {
1678 enc = &state->newkeys[MODE_IN]->enc;
1679 mac = &state->newkeys[MODE_IN]->mac;
1680 comp = &state->newkeys[MODE_IN]->comp;
1681 /* disable mac for authenticated encryption */
1682 if ((authlen = cipher_authlen(enc->cipher)) != 0)
1683 mac = NULL;
1684 }
1685 maclen = mac && mac->enabled ? mac->mac_len : 0;
1686 block_size = enc ? enc->block_size : 8;
1687 aadlen = (mac && mac->enabled && mac->etm) || authlen ? 4 : 0;
1688
1689 if (aadlen && state->packlen == 0) {
1690 if (cipher_get_length(&state->receive_context,
1691 &state->packlen, state->p_read.seqnr,
1692 sshbuf_ptr(state->input), sshbuf_len(state->input)) != 0)
1693 return 0;
1694 if (state->packlen < 1 + 4 ||
1695 state->packlen > PACKET_MAX_SIZE) {
1696#ifdef PACKET_DEBUG
1697 sshbuf_dump(state->input, stderr);
1698#endif
1699 logit("Bad packet length %u.", state->packlen);
1700 if ((r = sshpkt_disconnect(ssh, "Packet corrupt")) != 0)
1701 return r;
1702 return SSH_ERR_CONN_CORRUPT;
1703 }
1704 sshbuf_reset(state->incoming_packet);
1705 } else if (state->packlen == 0) {
1706 /*
1707 * check if input size is less than the cipher block size,
1708 * decrypt first block and extract length of incoming packet
1709 */
1710 if (sshbuf_len(state->input) < block_size)
1711 return 0;
1712 sshbuf_reset(state->incoming_packet);
1713 if ((r = sshbuf_reserve(state->incoming_packet, block_size,
1714 &cp)) != 0)
1715 goto out;
1716 if ((r = cipher_crypt(&state->receive_context,
1717 state->p_send.seqnr, cp, sshbuf_ptr(state->input),
1718 block_size, 0, 0)) != 0)
1719 goto out;
1720 state->packlen = PEEK_U32(sshbuf_ptr(state->incoming_packet));
1721 if (state->packlen < 1 + 4 ||
1722 state->packlen > PACKET_MAX_SIZE) {
1723#ifdef PACKET_DEBUG
1724 fprintf(stderr, "input: \n");
1725 sshbuf_dump(state->input, stderr);
1726 fprintf(stderr, "incoming_packet: \n");
1727 sshbuf_dump(state->incoming_packet, stderr);
1728#endif
1729 logit("Bad packet length %u.", state->packlen);
1730 return ssh_packet_start_discard(ssh, enc, mac,
1731 state->packlen, PACKET_MAX_SIZE);
1732 }
1733 if ((r = sshbuf_consume(state->input, block_size)) != 0)
1734 goto out;
1735 }
1736 DBG(debug("input: packet len %u", state->packlen+4));
1737
1738 if (aadlen) {
1739 /* only the payload is encrypted */
1740 need = state->packlen;
1741 } else {
1742 /*
1743 * the payload size and the payload are encrypted, but we
1744 * have a partial packet of block_size bytes
1745 */
1746 need = 4 + state->packlen - block_size;
1747 }
1748 DBG(debug("partial packet: block %d, need %d, maclen %d, authlen %d,"
1749 " aadlen %d", block_size, need, maclen, authlen, aadlen));
1750 if (need % block_size != 0) {
1751 logit("padding error: need %d block %d mod %d",
1752 need, block_size, need % block_size);
1753 return ssh_packet_start_discard(ssh, enc, mac,
1754 state->packlen, PACKET_MAX_SIZE - block_size);
1755 }
1756 /*
1757 * check if the entire packet has been received and
1758 * decrypt into incoming_packet:
1759 * 'aadlen' bytes are unencrypted, but authenticated.
1760 * 'need' bytes are encrypted, followed by either
1761 * 'authlen' bytes of authentication tag or
1762 * 'maclen' bytes of message authentication code.
1763 */
1764 if (sshbuf_len(state->input) < aadlen + need + authlen + maclen)
1765 return 0;
1766#ifdef PACKET_DEBUG
1767 fprintf(stderr, "read_poll enc/full: ");
1768 sshbuf_dump(state->input, stderr);
1769#endif
1770 /* EtM: compute mac over encrypted input */
1771 if (mac && mac->enabled && mac->etm) {
1772 if ((r = mac_compute(mac, state->p_read.seqnr,
1773 sshbuf_ptr(state->input), aadlen + need,
1774 macbuf, sizeof(macbuf))) != 0)
1775 goto out;
1776 }
1777 if ((r = sshbuf_reserve(state->incoming_packet, aadlen + need,
1778 &cp)) != 0)
1779 goto out;
1780 if ((r = cipher_crypt(&state->receive_context, state->p_read.seqnr, cp,
1781 sshbuf_ptr(state->input), need, aadlen, authlen)) != 0)
1782 goto out;
1783 if ((r = sshbuf_consume(state->input, aadlen + need + authlen)) != 0)
1784 goto out;
1785 /*
1786 * compute MAC over seqnr and packet,
1787 * increment sequence number for incoming packet
1788 */
1789 if (mac && mac->enabled) {
1790 if (!mac->etm)
1791 if ((r = mac_compute(mac, state->p_read.seqnr,
1792 sshbuf_ptr(state->incoming_packet),
1793 sshbuf_len(state->incoming_packet),
1794 macbuf, sizeof(macbuf))) != 0)
1795 goto out;
1796 if (timingsafe_bcmp(macbuf, sshbuf_ptr(state->input),
1797 mac->mac_len) != 0) {
1798 logit("Corrupted MAC on input.");
1799 if (need > PACKET_MAX_SIZE)
1800 return SSH_ERR_INTERNAL_ERROR;
1801 return ssh_packet_start_discard(ssh, enc, mac,
1802 state->packlen, PACKET_MAX_SIZE - need);
1803 }
1804
1805 DBG(debug("MAC #%d ok", state->p_read.seqnr));
1806 if ((r = sshbuf_consume(state->input, mac->mac_len)) != 0)
1807 goto out;
1808 }
1809 if (seqnr_p != NULL)
1810 *seqnr_p = state->p_read.seqnr;
1811 if (++state->p_read.seqnr == 0)
1812 logit("incoming seqnr wraps around");
1813 if (++state->p_read.packets == 0)
1814 if (!(ssh->compat & SSH_BUG_NOREKEY))
1815 return SSH_ERR_NEED_REKEY;
1816 state->p_read.blocks += (state->packlen + 4) / block_size;
1817 state->p_read.bytes += state->packlen + 4;
1818
1819 /* get padlen */
1820 padlen = sshbuf_ptr(state->incoming_packet)[4];
1821 DBG(debug("input: padlen %d", padlen));
1822 if (padlen < 4) {
1823 if ((r = sshpkt_disconnect(ssh,
1824 "Corrupted padlen %d on input.", padlen)) != 0 ||
1825 (r = ssh_packet_write_wait(ssh)) != 0)
1826 return r;
1827 return SSH_ERR_CONN_CORRUPT;
1828 }
1829
1830 /* skip packet size + padlen, discard padding */
1831 if ((r = sshbuf_consume(state->incoming_packet, 4 + 1)) != 0 ||
1832 ((r = sshbuf_consume_end(state->incoming_packet, padlen)) != 0))
1833 goto out;
1834
1835 DBG(debug("input: len before de-compress %zd",
1836 sshbuf_len(state->incoming_packet)));
1837 if (comp && comp->enabled) {
1838 sshbuf_reset(state->compression_buffer);
1839 if ((r = uncompress_buffer(ssh, state->incoming_packet,
1840 state->compression_buffer)) != 0)
1841 goto out;
1842 sshbuf_reset(state->incoming_packet);
1843 if ((r = sshbuf_putb(state->incoming_packet,
1844 state->compression_buffer)) != 0)
1845 goto out;
1846 DBG(debug("input: len after de-compress %zd",
1847 sshbuf_len(state->incoming_packet)));
1848 }
1849 /*
1850 * get packet type, implies consume.
1851 * return length of payload (without type field)
1852 */
1853 if ((r = sshbuf_get_u8(state->incoming_packet, typep)) != 0)
1854 goto out;
1855 if (ssh_packet_log_type(*typep))
1856 debug3("receive packet: type %u", *typep);
1857 if (*typep < SSH2_MSG_MIN || *typep >= SSH2_MSG_LOCAL_MIN) {
1858 if ((r = sshpkt_disconnect(ssh,
1859 "Invalid ssh2 packet type: %d", *typep)) != 0 ||
1860 (r = ssh_packet_write_wait(ssh)) != 0)
1861 return r;
1862 return SSH_ERR_PROTOCOL_ERROR;
1863 }
1864 if (*typep == SSH2_MSG_NEWKEYS)
1865 r = ssh_set_newkeys(ssh, MODE_IN);
1866 else if (*typep == SSH2_MSG_USERAUTH_SUCCESS && !state->server_side)
1867 r = ssh_packet_enable_delayed_compress(ssh);
1868 else
1869 r = 0;
1870#ifdef PACKET_DEBUG
1871 fprintf(stderr, "read/plain[%d]:\r\n", *typep);
1872 sshbuf_dump(state->incoming_packet, stderr);
1873#endif
1874 /* reset for next packet */
1875 state->packlen = 0;
1876
1877 /* do we need to rekey? */
1878 if (ssh_packet_need_rekeying(ssh, 0)) {
1879 debug3("%s: rekex triggered", __func__);
1880 if ((r = kex_start_rekex(ssh)) != 0)
1881 return r;
1882 }
1883 out:
1884 return r;
1885}
1886
1887int
1888ssh_packet_read_poll_seqnr(struct ssh *ssh, u_char *typep, u_int32_t *seqnr_p)
1889{
1890 struct session_state *state = ssh->state;
1891 u_int reason, seqnr;
1892 int r;
1893 u_char *msg;
1894
1895 for (;;) {
1896 msg = NULL;
1897 if (compat20) {
1898 r = ssh_packet_read_poll2(ssh, typep, seqnr_p);
1899 if (r != 0)
1900 return r;
1901 if (*typep) {
1902 state->keep_alive_timeouts = 0;
1903 DBG(debug("received packet type %d", *typep));
1904 }
1905 switch (*typep) {
1906 case SSH2_MSG_IGNORE:
1907 debug3("Received SSH2_MSG_IGNORE");
1908 break;
1909 case SSH2_MSG_DEBUG:
1910 if ((r = sshpkt_get_u8(ssh, NULL)) != 0 ||
1911 (r = sshpkt_get_string(ssh, &msg, NULL)) != 0 ||
1912 (r = sshpkt_get_string(ssh, NULL, NULL)) != 0) {
1913 free(msg);
1914 return r;
1915 }
1916 debug("Remote: %.900s", msg);
1917 free(msg);
1918 break;
1919 case SSH2_MSG_DISCONNECT:
1920 if ((r = sshpkt_get_u32(ssh, &reason)) != 0 ||
1921 (r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1922 return r;
1923 /* Ignore normal client exit notifications */
1924 do_log2(ssh->state->server_side &&
1925 reason == SSH2_DISCONNECT_BY_APPLICATION ?
1926 SYSLOG_LEVEL_INFO : SYSLOG_LEVEL_ERROR,
1927 "Received disconnect from %s port %d:"
1928 "%u: %.400s", ssh_remote_ipaddr(ssh),
1929 ssh_remote_port(ssh), reason, msg);
1930 free(msg);
1931 return SSH_ERR_DISCONNECTED;
1932 case SSH2_MSG_UNIMPLEMENTED:
1933 if ((r = sshpkt_get_u32(ssh, &seqnr)) != 0)
1934 return r;
1935 debug("Received SSH2_MSG_UNIMPLEMENTED for %u",
1936 seqnr);
1937 break;
1938 default:
1939 return 0;
1940 }
1941 } else {
1942 r = ssh_packet_read_poll1(ssh, typep);
1943 switch (*typep) {
1944 case SSH_MSG_NONE:
1945 return SSH_MSG_NONE;
1946 case SSH_MSG_IGNORE:
1947 break;
1948 case SSH_MSG_DEBUG:
1949 if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1950 return r;
1951 debug("Remote: %.900s", msg);
1952 free(msg);
1953 break;
1954 case SSH_MSG_DISCONNECT:
1955 if ((r = sshpkt_get_string(ssh, &msg, NULL)) != 0)
1956 return r;
1957 logit("Received disconnect from %s port %d: "
1958 "%.400s", ssh_remote_ipaddr(ssh),
1959 ssh_remote_port(ssh), msg);
1960 free(msg);
1961 return SSH_ERR_DISCONNECTED;
1962 default:
1963 DBG(debug("received packet type %d", *typep));
1964 return 0;
1965 }
1966 }
1967 }
1968}
1969
1970/*
1971 * Buffers the given amount of input characters. This is intended to be used
1972 * together with packet_read_poll.
1973 */
1974
1975int
1976ssh_packet_process_incoming(struct ssh *ssh, const char *buf, u_int len)
1977{
1978 struct session_state *state = ssh->state;
1979 int r;
1980
1981 if (state->packet_discard) {
1982 state->keep_alive_timeouts = 0; /* ?? */
1983 if (len >= state->packet_discard) {
1984 if ((r = ssh_packet_stop_discard(ssh)) != 0)
1985 return r;
1986 }
1987 state->packet_discard -= len;
1988 return 0;
1989 }
1990 if ((r = sshbuf_put(ssh->state->input, buf, len)) != 0)
1991 return r;
1992
1993 return 0;
1994}
1995
1996int
1997ssh_packet_remaining(struct ssh *ssh)
1998{
1999 return sshbuf_len(ssh->state->incoming_packet);
2000}
2001
2002/*
2003 * Sends a diagnostic message from the server to the client. This message
2004 * can be sent at any time (but not while constructing another message). The
2005 * message is printed immediately, but only if the client is being executed
2006 * in verbose mode. These messages are primarily intended to ease debugging
2007 * authentication problems. The length of the formatted message must not
2008 * exceed 1024 bytes. This will automatically call ssh_packet_write_wait.
2009 */
2010void
2011ssh_packet_send_debug(struct ssh *ssh, const char *fmt,...)
2012{
2013 char buf[1024];
2014 va_list args;
2015 int r;
2016
2017 if (compat20 && (ssh->compat & SSH_BUG_DEBUG))
2018 return;
2019
2020 va_start(args, fmt);
2021 vsnprintf(buf, sizeof(buf), fmt, args);
2022 va_end(args);
2023
2024 if (compat20) {
2025 if ((r = sshpkt_start(ssh, SSH2_MSG_DEBUG)) != 0 ||
2026 (r = sshpkt_put_u8(ssh, 0)) != 0 || /* always display */
2027 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2028 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2029 (r = sshpkt_send(ssh)) != 0)
2030 fatal("%s: %s", __func__, ssh_err(r));
2031 } else {
2032 if ((r = sshpkt_start(ssh, SSH_MSG_DEBUG)) != 0 ||
2033 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2034 (r = sshpkt_send(ssh)) != 0)
2035 fatal("%s: %s", __func__, ssh_err(r));
2036 }
2037 if ((r = ssh_packet_write_wait(ssh)) != 0)
2038 fatal("%s: %s", __func__, ssh_err(r));
2039}
2040
2041/*
2042 * Pretty-print connection-terminating errors and exit.
2043 */
2044void
2045sshpkt_fatal(struct ssh *ssh, const char *tag, int r)
2046{
2047 switch (r) {
2048 case SSH_ERR_CONN_CLOSED:
2049 logit("Connection closed by %.200s port %d",
2050 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
2051 cleanup_exit(255);
2052 case SSH_ERR_CONN_TIMEOUT:
2053 logit("Connection %s %.200s port %d timed out",
2054 ssh->state->server_side ? "from" : "to",
2055 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
2056 cleanup_exit(255);
2057 case SSH_ERR_DISCONNECTED:
2058 logit("Disconnected from %.200s port %d",
2059 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
2060 cleanup_exit(255);
2061 case SSH_ERR_SYSTEM_ERROR:
2062 if (errno == ECONNRESET) {
2063 logit("Connection reset by %.200s port %d",
2064 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh));
2065 cleanup_exit(255);
2066 }
2067 /* FALLTHROUGH */
2068 case SSH_ERR_NO_CIPHER_ALG_MATCH:
2069 case SSH_ERR_NO_MAC_ALG_MATCH:
2070 case SSH_ERR_NO_COMPRESS_ALG_MATCH:
2071 case SSH_ERR_NO_KEX_ALG_MATCH:
2072 case SSH_ERR_NO_HOSTKEY_ALG_MATCH:
2073 if (ssh && ssh->kex && ssh->kex->failed_choice) {
|
2080 fatal("Unable to negotiate with %.200s port %d: %s. "
2081 "Their offer: %s", ssh_remote_ipaddr(ssh),
2082 ssh_remote_port(ssh), ssh_err(r),
2083 ssh->kex->failed_choice);
2084 }
2085 /* FALLTHROUGH */
2086 default:
2087 fatal("%s%sConnection %s %.200s port %d: %s",
2088 tag != NULL ? tag : "", tag != NULL ? ": " : "",
2089 ssh->state->server_side ? "from" : "to",
2090 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), ssh_err(r));
2091 }
2092}
2093
2094/*
2095 * Logs the error plus constructs and sends a disconnect packet, closes the
2096 * connection, and exits. This function never returns. The error message
2097 * should not contain a newline. The length of the formatted message must
2098 * not exceed 1024 bytes.
2099 */
2100void
2101ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
2102{
2103 char buf[1024];
2104 va_list args;
2105 static int disconnecting = 0;
2106 int r;
2107
2108 if (disconnecting) /* Guard against recursive invocations. */
2109 fatal("packet_disconnect called recursively.");
2110 disconnecting = 1;
2111
2112 /*
2113 * Format the message. Note that the caller must make sure the
2114 * message is of limited size.
2115 */
2116 va_start(args, fmt);
2117 vsnprintf(buf, sizeof(buf), fmt, args);
2118 va_end(args);
2119
2120 /* Display the error locally */
2121 logit("Disconnecting: %.100s", buf);
2122
2123 /*
2124 * Send the disconnect message to the other side, and wait
2125 * for it to get sent.
2126 */
2127 if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
2128 sshpkt_fatal(ssh, __func__, r);
2129
2130 if ((r = ssh_packet_write_wait(ssh)) != 0)
2131 sshpkt_fatal(ssh, __func__, r);
2132
2133 /* Close the connection. */
2134 ssh_packet_close(ssh);
2135 cleanup_exit(255);
2136}
2137
2138/*
2139 * Checks if there is any buffered output, and tries to write some of
2140 * the output.
2141 */
2142int
2143ssh_packet_write_poll(struct ssh *ssh)
2144{
2145 struct session_state *state = ssh->state;
2146 int len = sshbuf_len(state->output);
2147 int r;
2148
2149 if (len > 0) {
2150 len = write(state->connection_out,
2151 sshbuf_ptr(state->output), len);
2152 if (len == -1) {
2153 if (errno == EINTR || errno == EAGAIN ||
2154 errno == EWOULDBLOCK)
2155 return 0;
2156 return SSH_ERR_SYSTEM_ERROR;
2157 }
2158 if (len == 0)
2159 return SSH_ERR_CONN_CLOSED;
2160 if ((r = sshbuf_consume(state->output, len)) != 0)
2161 return r;
2162 }
2163 return 0;
2164}
2165
2166/*
2167 * Calls packet_write_poll repeatedly until all pending output data has been
2168 * written.
2169 */
2170int
2171ssh_packet_write_wait(struct ssh *ssh)
2172{
2173 fd_set *setp;
2174 int ret, r, ms_remain = 0;
2175 struct timeval start, timeout, *timeoutp = NULL;
2176 struct session_state *state = ssh->state;
2177
2178 setp = calloc(howmany(state->connection_out + 1,
2179 NFDBITS), sizeof(fd_mask));
2180 if (setp == NULL)
2181 return SSH_ERR_ALLOC_FAIL;
2182 if ((r = ssh_packet_write_poll(ssh)) != 0) {
2183 free(setp);
2184 return r;
2185 }
2186 while (ssh_packet_have_data_to_write(ssh)) {
2187 memset(setp, 0, howmany(state->connection_out + 1,
2188 NFDBITS) * sizeof(fd_mask));
2189 FD_SET(state->connection_out, setp);
2190
2191 if (state->packet_timeout_ms > 0) {
2192 ms_remain = state->packet_timeout_ms;
2193 timeoutp = &timeout;
2194 }
2195 for (;;) {
2196 if (state->packet_timeout_ms != -1) {
2197 ms_to_timeval(&timeout, ms_remain);
2198 gettimeofday(&start, NULL);
2199 }
2200 if ((ret = select(state->connection_out + 1,
2201 NULL, setp, NULL, timeoutp)) >= 0)
2202 break;
2203 if (errno != EAGAIN && errno != EINTR &&
2204 errno != EWOULDBLOCK)
2205 break;
2206 if (state->packet_timeout_ms == -1)
2207 continue;
2208 ms_subtract_diff(&start, &ms_remain);
2209 if (ms_remain <= 0) {
2210 ret = 0;
2211 break;
2212 }
2213 }
2214 if (ret == 0) {
2215 free(setp);
2216 return SSH_ERR_CONN_TIMEOUT;
2217 }
2218 if ((r = ssh_packet_write_poll(ssh)) != 0) {
2219 free(setp);
2220 return r;
2221 }
2222 }
2223 free(setp);
2224 return 0;
2225}
2226
2227/* Returns true if there is buffered data to write to the connection. */
2228
2229int
2230ssh_packet_have_data_to_write(struct ssh *ssh)
2231{
2232 return sshbuf_len(ssh->state->output) != 0;
2233}
2234
2235/* Returns true if there is not too much data to write to the connection. */
2236
2237int
2238ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
2239{
2240 if (ssh->state->interactive_mode)
2241 return sshbuf_len(ssh->state->output) < 16384;
2242 else
2243 return sshbuf_len(ssh->state->output) < 128 * 1024;
2244}
2245
2246void
2247ssh_packet_set_tos(struct ssh *ssh, int tos)
2248{
2249#ifndef IP_TOS_IS_BROKEN
2250 if (!ssh_packet_connection_is_on_socket(ssh))
2251 return;
2252 switch (ssh_packet_connection_af(ssh)) {
2253# ifdef IP_TOS
2254 case AF_INET:
2255 debug3("%s: set IP_TOS 0x%02x", __func__, tos);
2256 if (setsockopt(ssh->state->connection_in,
2257 IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2258 error("setsockopt IP_TOS %d: %.100s:",
2259 tos, strerror(errno));
2260 break;
2261# endif /* IP_TOS */
2262# ifdef IPV6_TCLASS
2263 case AF_INET6:
2264 debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
2265 if (setsockopt(ssh->state->connection_in,
2266 IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2267 error("setsockopt IPV6_TCLASS %d: %.100s:",
2268 tos, strerror(errno));
2269 break;
2270# endif /* IPV6_TCLASS */
2271 }
2272#endif /* IP_TOS_IS_BROKEN */
2273}
2274
2275/* Informs that the current session is interactive. Sets IP flags for that. */
2276
2277void
2278ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
2279{
2280 struct session_state *state = ssh->state;
2281
2282 if (state->set_interactive_called)
2283 return;
2284 state->set_interactive_called = 1;
2285
2286 /* Record that we are in interactive mode. */
2287 state->interactive_mode = interactive;
2288
2289 /* Only set socket options if using a socket. */
2290 if (!ssh_packet_connection_is_on_socket(ssh))
2291 return;
2292 set_nodelay(state->connection_in);
2293 ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2294 qos_bulk);
2295}
2296
2297/* Returns true if the current connection is interactive. */
2298
2299int
2300ssh_packet_is_interactive(struct ssh *ssh)
2301{
2302 return ssh->state->interactive_mode;
2303}
2304
2305int
2306ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
2307{
2308 struct session_state *state = ssh->state;
2309
2310 if (state->set_maxsize_called) {
2311 logit("packet_set_maxsize: called twice: old %d new %d",
2312 state->max_packet_size, s);
2313 return -1;
2314 }
2315 if (s < 4 * 1024 || s > 1024 * 1024) {
2316 logit("packet_set_maxsize: bad size %d", s);
2317 return -1;
2318 }
2319 state->set_maxsize_called = 1;
2320 debug("packet_set_maxsize: setting to %d", s);
2321 state->max_packet_size = s;
2322 return s;
2323}
2324
2325int
2326ssh_packet_inc_alive_timeouts(struct ssh *ssh)
2327{
2328 return ++ssh->state->keep_alive_timeouts;
2329}
2330
2331void
2332ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
2333{
2334 ssh->state->keep_alive_timeouts = ka;
2335}
2336
2337u_int
2338ssh_packet_get_maxsize(struct ssh *ssh)
2339{
2340 return ssh->state->max_packet_size;
2341}
2342
2343/*
2344 * 9.2. Ignored Data Message
2345 *
2346 * byte SSH_MSG_IGNORE
2347 * string data
2348 *
2349 * All implementations MUST understand (and ignore) this message at any
2350 * time (after receiving the protocol version). No implementation is
2351 * required to send them. This message can be used as an additional
2352 * protection measure against advanced traffic analysis techniques.
2353 */
2354void
2355ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
2356{
2357 u_int32_t rnd = 0;
2358 int r, i;
2359
2360 if ((r = sshpkt_start(ssh, compat20 ?
2361 SSH2_MSG_IGNORE : SSH_MSG_IGNORE)) != 0 ||
2362 (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2363 fatal("%s: %s", __func__, ssh_err(r));
2364 for (i = 0; i < nbytes; i++) {
2365 if (i % 4 == 0)
2366 rnd = arc4random();
2367 if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2368 fatal("%s: %s", __func__, ssh_err(r));
2369 rnd >>= 8;
2370 }
2371}
2372
2373void
2374ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, time_t seconds)
2375{
2376 debug3("rekey after %llu bytes, %d seconds", (unsigned long long)bytes,
2377 (int)seconds);
2378 ssh->state->rekey_limit = bytes;
2379 ssh->state->rekey_interval = seconds;
2380}
2381
2382time_t
2383ssh_packet_get_rekey_timeout(struct ssh *ssh)
2384{
2385 time_t seconds;
2386
2387 seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
2388 monotime();
2389 return (seconds <= 0 ? 1 : seconds);
2390}
2391
2392void
2393ssh_packet_set_server(struct ssh *ssh)
2394{
2395 ssh->state->server_side = 1;
2396}
2397
2398void
2399ssh_packet_set_authenticated(struct ssh *ssh)
2400{
2401 ssh->state->after_authentication = 1;
2402}
2403
2404void *
2405ssh_packet_get_input(struct ssh *ssh)
2406{
2407 return (void *)ssh->state->input;
2408}
2409
2410void *
2411ssh_packet_get_output(struct ssh *ssh)
2412{
2413 return (void *)ssh->state->output;
2414}
2415
2416/* Reset after_authentication and reset compression in post-auth privsep */
2417static int
2418ssh_packet_set_postauth(struct ssh *ssh)
2419{
2420 struct sshcomp *comp;
2421 int r, mode;
2422
2423 debug("%s: called", __func__);
2424 /* This was set in net child, but is not visible in user child */
2425 ssh->state->after_authentication = 1;
2426 ssh->state->rekeying = 0;
2427 for (mode = 0; mode < MODE_MAX; mode++) {
2428 if (ssh->state->newkeys[mode] == NULL)
2429 continue;
2430 comp = &ssh->state->newkeys[mode]->comp;
2431 if (comp && comp->enabled &&
2432 (r = ssh_packet_init_compression(ssh)) != 0)
2433 return r;
2434 }
2435 return 0;
2436}
2437
2438/* Packet state (de-)serialization for privsep */
2439
2440/* turn kex into a blob for packet state serialization */
2441static int
2442kex_to_blob(struct sshbuf *m, struct kex *kex)
2443{
2444 int r;
2445
2446 if ((r = sshbuf_put_string(m, kex->session_id,
2447 kex->session_id_len)) != 0 ||
2448 (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2449 (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2450 (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2451 (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2452 (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2453 (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2454 (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2455 (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2456 return r;
2457 return 0;
2458}
2459
2460/* turn key exchange results into a blob for packet state serialization */
2461static int
2462newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2463{
2464 struct sshbuf *b;
2465 struct sshcipher_ctx *cc;
2466 struct sshcomp *comp;
2467 struct sshenc *enc;
2468 struct sshmac *mac;
2469 struct newkeys *newkey;
2470 int r;
2471
2472 if ((newkey = ssh->state->newkeys[mode]) == NULL)
2473 return SSH_ERR_INTERNAL_ERROR;
2474 enc = &newkey->enc;
2475 mac = &newkey->mac;
2476 comp = &newkey->comp;
2477 cc = (mode == MODE_OUT) ? &ssh->state->send_context :
2478 &ssh->state->receive_context;
2479 if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2480 return r;
2481 if ((b = sshbuf_new()) == NULL)
2482 return SSH_ERR_ALLOC_FAIL;
2483 /* The cipher struct is constant and shared, you export pointer */
2484 if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2485 (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2486 (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2487 (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2488 (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2489 (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2490 goto out;
2491 if (cipher_authlen(enc->cipher) == 0) {
2492 if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2493 (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2494 (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2495 goto out;
2496 }
2497 if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2498 (r = sshbuf_put_u32(b, comp->enabled)) != 0 ||
2499 (r = sshbuf_put_cstring(b, comp->name)) != 0)
2500 goto out;
2501 r = sshbuf_put_stringb(m, b);
2502 out:
2503 sshbuf_free(b);
2504 return r;
2505}
2506
2507/* serialize packet state into a blob */
2508int
2509ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2510{
2511 struct session_state *state = ssh->state;
2512 u_char *p;
2513 size_t slen, rlen;
2514 int r, ssh1cipher;
2515
2516 if (!compat20) {
2517 ssh1cipher = cipher_get_number(state->receive_context.cipher);
2518 slen = cipher_get_keyiv_len(&state->send_context);
2519 rlen = cipher_get_keyiv_len(&state->receive_context);
2520 if ((r = sshbuf_put_u32(m, state->remote_protocol_flags)) != 0 ||
2521 (r = sshbuf_put_u32(m, ssh1cipher)) != 0 ||
2522 (r = sshbuf_put_string(m, state->ssh1_key, state->ssh1_keylen)) != 0 ||
2523 (r = sshbuf_put_u32(m, slen)) != 0 ||
2524 (r = sshbuf_reserve(m, slen, &p)) != 0 ||
2525 (r = cipher_get_keyiv(&state->send_context, p, slen)) != 0 ||
2526 (r = sshbuf_put_u32(m, rlen)) != 0 ||
2527 (r = sshbuf_reserve(m, rlen, &p)) != 0 ||
2528 (r = cipher_get_keyiv(&state->receive_context, p, rlen)) != 0)
2529 return r;
2530 } else {
2531 if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2532 (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2533 (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2534 (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2535 (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2536 (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2537 (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2538 (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2539 (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2540 (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2541 (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2542 (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2543 (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0)
2544 return r;
2545 }
2546
2547 slen = cipher_get_keycontext(&state->send_context, NULL);
2548 rlen = cipher_get_keycontext(&state->receive_context, NULL);
2549 if ((r = sshbuf_put_u32(m, slen)) != 0 ||
2550 (r = sshbuf_reserve(m, slen, &p)) != 0)
2551 return r;
2552 if (cipher_get_keycontext(&state->send_context, p) != (int)slen)
2553 return SSH_ERR_INTERNAL_ERROR;
2554 if ((r = sshbuf_put_u32(m, rlen)) != 0 ||
2555 (r = sshbuf_reserve(m, rlen, &p)) != 0)
2556 return r;
2557 if (cipher_get_keycontext(&state->receive_context, p) != (int)rlen)
2558 return SSH_ERR_INTERNAL_ERROR;
2559
2560 if ((r = ssh_packet_get_compress_state(m, ssh)) != 0 ||
2561 (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2562 (r = sshbuf_put_stringb(m, state->output)) != 0)
2563 return r;
2564
2565 return 0;
2566}
2567
2568/* restore key exchange results from blob for packet state de-serialization */
2569static int
2570newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2571{
2572 struct sshbuf *b = NULL;
2573 struct sshcomp *comp;
2574 struct sshenc *enc;
2575 struct sshmac *mac;
2576 struct newkeys *newkey = NULL;
2577 size_t keylen, ivlen, maclen;
2578 int r;
2579
2580 if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2581 r = SSH_ERR_ALLOC_FAIL;
2582 goto out;
2583 }
2584 if ((r = sshbuf_froms(m, &b)) != 0)
2585 goto out;
2586#ifdef DEBUG_PK
2587 sshbuf_dump(b, stderr);
2588#endif
2589 enc = &newkey->enc;
2590 mac = &newkey->mac;
2591 comp = &newkey->comp;
2592
2593 if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2594 (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2595 (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2596 (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2597 (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2598 (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2599 goto out;
2600 if (cipher_authlen(enc->cipher) == 0) {
2601 if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2602 goto out;
2603 if ((r = mac_setup(mac, mac->name)) != 0)
2604 goto out;
2605 if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2606 (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2607 goto out;
2608 if (maclen > mac->key_len) {
2609 r = SSH_ERR_INVALID_FORMAT;
2610 goto out;
2611 }
2612 mac->key_len = maclen;
2613 }
2614 if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2615 (r = sshbuf_get_u32(b, (u_int *)&comp->enabled)) != 0 ||
2616 (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2617 goto out;
2618 if (enc->name == NULL ||
2619 cipher_by_name(enc->name) != enc->cipher) {
2620 r = SSH_ERR_INVALID_FORMAT;
2621 goto out;
2622 }
2623 if (sshbuf_len(b) != 0) {
2624 r = SSH_ERR_INVALID_FORMAT;
2625 goto out;
2626 }
2627 enc->key_len = keylen;
2628 enc->iv_len = ivlen;
2629 ssh->kex->newkeys[mode] = newkey;
2630 newkey = NULL;
2631 r = 0;
2632 out:
2633 free(newkey);
2634 sshbuf_free(b);
2635 return r;
2636}
2637
2638/* restore kex from blob for packet state de-serialization */
2639static int
2640kex_from_blob(struct sshbuf *m, struct kex **kexp)
2641{
2642 struct kex *kex;
2643 int r;
2644
2645 if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2646 (kex->my = sshbuf_new()) == NULL ||
2647 (kex->peer = sshbuf_new()) == NULL) {
2648 r = SSH_ERR_ALLOC_FAIL;
2649 goto out;
2650 }
2651 if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2652 (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2653 (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2654 (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2655 (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2656 (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2657 (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2658 (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2659 (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2660 goto out;
2661 kex->server = 1;
2662 kex->done = 1;
2663 r = 0;
2664 out:
2665 if (r != 0 || kexp == NULL) {
2666 if (kex != NULL) {
2667 sshbuf_free(kex->my);
2668 sshbuf_free(kex->peer);
2669 free(kex);
2670 }
2671 if (kexp != NULL)
2672 *kexp = NULL;
2673 } else {
2674 *kexp = kex;
2675 }
2676 return r;
2677}
2678
2679/*
2680 * Restore packet state from content of blob 'm' (de-serialization).
2681 * Note that 'm' will be partially consumed on parsing or any other errors.
2682 */
2683int
2684ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2685{
2686 struct session_state *state = ssh->state;
2687 const u_char *ssh1key, *ivin, *ivout, *keyin, *keyout, *input, *output;
2688 size_t ssh1keylen, rlen, slen, ilen, olen;
2689 int r;
2690 u_int ssh1cipher = 0;
2691
2692 if (!compat20) {
2693 if ((r = sshbuf_get_u32(m, &state->remote_protocol_flags)) != 0 ||
2694 (r = sshbuf_get_u32(m, &ssh1cipher)) != 0 ||
2695 (r = sshbuf_get_string_direct(m, &ssh1key, &ssh1keylen)) != 0 ||
2696 (r = sshbuf_get_string_direct(m, &ivout, &slen)) != 0 ||
2697 (r = sshbuf_get_string_direct(m, &ivin, &rlen)) != 0)
2698 return r;
2699 if (ssh1cipher > INT_MAX)
2700 return SSH_ERR_KEY_UNKNOWN_CIPHER;
2701 ssh_packet_set_encryption_key(ssh, ssh1key, ssh1keylen,
2702 (int)ssh1cipher);
2703 if (cipher_get_keyiv_len(&state->send_context) != (int)slen ||
2704 cipher_get_keyiv_len(&state->receive_context) != (int)rlen)
2705 return SSH_ERR_INVALID_FORMAT;
2706 if ((r = cipher_set_keyiv(&state->send_context, ivout)) != 0 ||
2707 (r = cipher_set_keyiv(&state->receive_context, ivin)) != 0)
2708 return r;
2709 } else {
2710 if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2711 (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2712 (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2713 (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2714 (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2715 (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2716 (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2717 (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2718 (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2719 (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2720 (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2721 (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2722 (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2723 return r;
2724 /*
2725 * We set the time here so that in post-auth privsep slave we
2726 * count from the completion of the authentication.
2727 */
2728 state->rekey_time = monotime();
2729 /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2730 if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2731 (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2732 return r;
2733 }
2734 if ((r = sshbuf_get_string_direct(m, &keyout, &slen)) != 0 ||
2735 (r = sshbuf_get_string_direct(m, &keyin, &rlen)) != 0)
2736 return r;
2737 if (cipher_get_keycontext(&state->send_context, NULL) != (int)slen ||
2738 cipher_get_keycontext(&state->receive_context, NULL) != (int)rlen)
2739 return SSH_ERR_INVALID_FORMAT;
2740 cipher_set_keycontext(&state->send_context, keyout);
2741 cipher_set_keycontext(&state->receive_context, keyin);
2742
2743 if ((r = ssh_packet_set_compress_state(ssh, m)) != 0 ||
2744 (r = ssh_packet_set_postauth(ssh)) != 0)
2745 return r;
2746
2747 sshbuf_reset(state->input);
2748 sshbuf_reset(state->output);
2749 if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2750 (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2751 (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2752 (r = sshbuf_put(state->output, output, olen)) != 0)
2753 return r;
2754
2755 if (sshbuf_len(m))
2756 return SSH_ERR_INVALID_FORMAT;
2757 debug3("%s: done", __func__);
2758 return 0;
2759}
2760
2761/* NEW API */
2762
2763/* put data to the outgoing packet */
2764
2765int
2766sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2767{
2768 return sshbuf_put(ssh->state->outgoing_packet, v, len);
2769}
2770
2771int
2772sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2773{
2774 return sshbuf_putb(ssh->state->outgoing_packet, b);
2775}
2776
2777int
2778sshpkt_put_u8(struct ssh *ssh, u_char val)
2779{
2780 return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2781}
2782
2783int
2784sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2785{
2786 return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2787}
2788
2789int
2790sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2791{
2792 return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2793}
2794
2795int
2796sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2797{
2798 return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2799}
2800
2801int
2802sshpkt_put_cstring(struct ssh *ssh, const void *v)
2803{
2804 return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2805}
2806
2807int
2808sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2809{
2810 return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2811}
2812
2813#ifdef WITH_OPENSSL
2814#ifdef OPENSSL_HAS_ECC
2815int
2816sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2817{
2818 return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2819}
2820#endif /* OPENSSL_HAS_ECC */
2821
2822#ifdef WITH_SSH1
2823int
2824sshpkt_put_bignum1(struct ssh *ssh, const BIGNUM *v)
2825{
2826 return sshbuf_put_bignum1(ssh->state->outgoing_packet, v);
2827}
2828#endif /* WITH_SSH1 */
2829
2830int
2831sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2832{
2833 return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2834}
2835#endif /* WITH_OPENSSL */
2836
2837/* fetch data from the incoming packet */
2838
2839int
2840sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2841{
2842 return sshbuf_get(ssh->state->incoming_packet, valp, len);
2843}
2844
2845int
2846sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2847{
2848 return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2849}
2850
2851int
2852sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2853{
2854 return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2855}
2856
2857int
2858sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2859{
2860 return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2861}
2862
2863int
2864sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2865{
2866 return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2867}
2868
2869int
2870sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2871{
2872 return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2873}
2874
2875int
2876sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2877{
2878 return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2879}
2880
2881#ifdef WITH_OPENSSL
2882#ifdef OPENSSL_HAS_ECC
2883int
2884sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2885{
2886 return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2887}
2888#endif /* OPENSSL_HAS_ECC */
2889
2890#ifdef WITH_SSH1
2891int
2892sshpkt_get_bignum1(struct ssh *ssh, BIGNUM *v)
2893{
2894 return sshbuf_get_bignum1(ssh->state->incoming_packet, v);
2895}
2896#endif /* WITH_SSH1 */
2897
2898int
2899sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2900{
2901 return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2902}
2903#endif /* WITH_OPENSSL */
2904
2905int
2906sshpkt_get_end(struct ssh *ssh)
2907{
2908 if (sshbuf_len(ssh->state->incoming_packet) > 0)
2909 return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2910 return 0;
2911}
2912
2913const u_char *
2914sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2915{
2916 if (lenp != NULL)
2917 *lenp = sshbuf_len(ssh->state->incoming_packet);
2918 return sshbuf_ptr(ssh->state->incoming_packet);
2919}
2920
2921/* start a new packet */
2922
2923int
2924sshpkt_start(struct ssh *ssh, u_char type)
2925{
2926 u_char buf[9];
2927 int len;
2928
2929 DBG(debug("packet_start[%d]", type));
2930 len = compat20 ? 6 : 9;
2931 memset(buf, 0, len - 1);
2932 buf[len - 1] = type;
2933 sshbuf_reset(ssh->state->outgoing_packet);
2934 return sshbuf_put(ssh->state->outgoing_packet, buf, len);
2935}
2936
2937/* send it */
2938
2939int
2940sshpkt_send(struct ssh *ssh)
2941{
2942 if (compat20)
2943 return ssh_packet_send2(ssh);
2944 else
2945 return ssh_packet_send1(ssh);
2946}
2947
2948int
2949sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2950{
2951 char buf[1024];
2952 va_list args;
2953 int r;
2954
2955 va_start(args, fmt);
2956 vsnprintf(buf, sizeof(buf), fmt, args);
2957 va_end(args);
2958
2959 if (compat20) {
2960 if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2961 (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2962 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2963 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2964 (r = sshpkt_send(ssh)) != 0)
2965 return r;
2966 } else {
2967 if ((r = sshpkt_start(ssh, SSH_MSG_DISCONNECT)) != 0 ||
2968 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2969 (r = sshpkt_send(ssh)) != 0)
2970 return r;
2971 }
2972 return 0;
2973}
2974
2975/* roundup current message to pad bytes */
2976int
2977sshpkt_add_padding(struct ssh *ssh, u_char pad)
2978{
2979 ssh->state->extra_pad = pad;
2980 return 0;
2981}
| 2074 fatal("Unable to negotiate with %.200s port %d: %s. "
2075 "Their offer: %s", ssh_remote_ipaddr(ssh),
2076 ssh_remote_port(ssh), ssh_err(r),
2077 ssh->kex->failed_choice);
2078 }
2079 /* FALLTHROUGH */
2080 default:
2081 fatal("%s%sConnection %s %.200s port %d: %s",
2082 tag != NULL ? tag : "", tag != NULL ? ": " : "",
2083 ssh->state->server_side ? "from" : "to",
2084 ssh_remote_ipaddr(ssh), ssh_remote_port(ssh), ssh_err(r));
2085 }
2086}
2087
2088/*
2089 * Logs the error plus constructs and sends a disconnect packet, closes the
2090 * connection, and exits. This function never returns. The error message
2091 * should not contain a newline. The length of the formatted message must
2092 * not exceed 1024 bytes.
2093 */
2094void
2095ssh_packet_disconnect(struct ssh *ssh, const char *fmt,...)
2096{
2097 char buf[1024];
2098 va_list args;
2099 static int disconnecting = 0;
2100 int r;
2101
2102 if (disconnecting) /* Guard against recursive invocations. */
2103 fatal("packet_disconnect called recursively.");
2104 disconnecting = 1;
2105
2106 /*
2107 * Format the message. Note that the caller must make sure the
2108 * message is of limited size.
2109 */
2110 va_start(args, fmt);
2111 vsnprintf(buf, sizeof(buf), fmt, args);
2112 va_end(args);
2113
2114 /* Display the error locally */
2115 logit("Disconnecting: %.100s", buf);
2116
2117 /*
2118 * Send the disconnect message to the other side, and wait
2119 * for it to get sent.
2120 */
2121 if ((r = sshpkt_disconnect(ssh, "%s", buf)) != 0)
2122 sshpkt_fatal(ssh, __func__, r);
2123
2124 if ((r = ssh_packet_write_wait(ssh)) != 0)
2125 sshpkt_fatal(ssh, __func__, r);
2126
2127 /* Close the connection. */
2128 ssh_packet_close(ssh);
2129 cleanup_exit(255);
2130}
2131
2132/*
2133 * Checks if there is any buffered output, and tries to write some of
2134 * the output.
2135 */
2136int
2137ssh_packet_write_poll(struct ssh *ssh)
2138{
2139 struct session_state *state = ssh->state;
2140 int len = sshbuf_len(state->output);
2141 int r;
2142
2143 if (len > 0) {
2144 len = write(state->connection_out,
2145 sshbuf_ptr(state->output), len);
2146 if (len == -1) {
2147 if (errno == EINTR || errno == EAGAIN ||
2148 errno == EWOULDBLOCK)
2149 return 0;
2150 return SSH_ERR_SYSTEM_ERROR;
2151 }
2152 if (len == 0)
2153 return SSH_ERR_CONN_CLOSED;
2154 if ((r = sshbuf_consume(state->output, len)) != 0)
2155 return r;
2156 }
2157 return 0;
2158}
2159
2160/*
2161 * Calls packet_write_poll repeatedly until all pending output data has been
2162 * written.
2163 */
2164int
2165ssh_packet_write_wait(struct ssh *ssh)
2166{
2167 fd_set *setp;
2168 int ret, r, ms_remain = 0;
2169 struct timeval start, timeout, *timeoutp = NULL;
2170 struct session_state *state = ssh->state;
2171
2172 setp = calloc(howmany(state->connection_out + 1,
2173 NFDBITS), sizeof(fd_mask));
2174 if (setp == NULL)
2175 return SSH_ERR_ALLOC_FAIL;
2176 if ((r = ssh_packet_write_poll(ssh)) != 0) {
2177 free(setp);
2178 return r;
2179 }
2180 while (ssh_packet_have_data_to_write(ssh)) {
2181 memset(setp, 0, howmany(state->connection_out + 1,
2182 NFDBITS) * sizeof(fd_mask));
2183 FD_SET(state->connection_out, setp);
2184
2185 if (state->packet_timeout_ms > 0) {
2186 ms_remain = state->packet_timeout_ms;
2187 timeoutp = &timeout;
2188 }
2189 for (;;) {
2190 if (state->packet_timeout_ms != -1) {
2191 ms_to_timeval(&timeout, ms_remain);
2192 gettimeofday(&start, NULL);
2193 }
2194 if ((ret = select(state->connection_out + 1,
2195 NULL, setp, NULL, timeoutp)) >= 0)
2196 break;
2197 if (errno != EAGAIN && errno != EINTR &&
2198 errno != EWOULDBLOCK)
2199 break;
2200 if (state->packet_timeout_ms == -1)
2201 continue;
2202 ms_subtract_diff(&start, &ms_remain);
2203 if (ms_remain <= 0) {
2204 ret = 0;
2205 break;
2206 }
2207 }
2208 if (ret == 0) {
2209 free(setp);
2210 return SSH_ERR_CONN_TIMEOUT;
2211 }
2212 if ((r = ssh_packet_write_poll(ssh)) != 0) {
2213 free(setp);
2214 return r;
2215 }
2216 }
2217 free(setp);
2218 return 0;
2219}
2220
2221/* Returns true if there is buffered data to write to the connection. */
2222
2223int
2224ssh_packet_have_data_to_write(struct ssh *ssh)
2225{
2226 return sshbuf_len(ssh->state->output) != 0;
2227}
2228
2229/* Returns true if there is not too much data to write to the connection. */
2230
2231int
2232ssh_packet_not_very_much_data_to_write(struct ssh *ssh)
2233{
2234 if (ssh->state->interactive_mode)
2235 return sshbuf_len(ssh->state->output) < 16384;
2236 else
2237 return sshbuf_len(ssh->state->output) < 128 * 1024;
2238}
2239
2240void
2241ssh_packet_set_tos(struct ssh *ssh, int tos)
2242{
2243#ifndef IP_TOS_IS_BROKEN
2244 if (!ssh_packet_connection_is_on_socket(ssh))
2245 return;
2246 switch (ssh_packet_connection_af(ssh)) {
2247# ifdef IP_TOS
2248 case AF_INET:
2249 debug3("%s: set IP_TOS 0x%02x", __func__, tos);
2250 if (setsockopt(ssh->state->connection_in,
2251 IPPROTO_IP, IP_TOS, &tos, sizeof(tos)) < 0)
2252 error("setsockopt IP_TOS %d: %.100s:",
2253 tos, strerror(errno));
2254 break;
2255# endif /* IP_TOS */
2256# ifdef IPV6_TCLASS
2257 case AF_INET6:
2258 debug3("%s: set IPV6_TCLASS 0x%02x", __func__, tos);
2259 if (setsockopt(ssh->state->connection_in,
2260 IPPROTO_IPV6, IPV6_TCLASS, &tos, sizeof(tos)) < 0)
2261 error("setsockopt IPV6_TCLASS %d: %.100s:",
2262 tos, strerror(errno));
2263 break;
2264# endif /* IPV6_TCLASS */
2265 }
2266#endif /* IP_TOS_IS_BROKEN */
2267}
2268
2269/* Informs that the current session is interactive. Sets IP flags for that. */
2270
2271void
2272ssh_packet_set_interactive(struct ssh *ssh, int interactive, int qos_interactive, int qos_bulk)
2273{
2274 struct session_state *state = ssh->state;
2275
2276 if (state->set_interactive_called)
2277 return;
2278 state->set_interactive_called = 1;
2279
2280 /* Record that we are in interactive mode. */
2281 state->interactive_mode = interactive;
2282
2283 /* Only set socket options if using a socket. */
2284 if (!ssh_packet_connection_is_on_socket(ssh))
2285 return;
2286 set_nodelay(state->connection_in);
2287 ssh_packet_set_tos(ssh, interactive ? qos_interactive :
2288 qos_bulk);
2289}
2290
2291/* Returns true if the current connection is interactive. */
2292
2293int
2294ssh_packet_is_interactive(struct ssh *ssh)
2295{
2296 return ssh->state->interactive_mode;
2297}
2298
2299int
2300ssh_packet_set_maxsize(struct ssh *ssh, u_int s)
2301{
2302 struct session_state *state = ssh->state;
2303
2304 if (state->set_maxsize_called) {
2305 logit("packet_set_maxsize: called twice: old %d new %d",
2306 state->max_packet_size, s);
2307 return -1;
2308 }
2309 if (s < 4 * 1024 || s > 1024 * 1024) {
2310 logit("packet_set_maxsize: bad size %d", s);
2311 return -1;
2312 }
2313 state->set_maxsize_called = 1;
2314 debug("packet_set_maxsize: setting to %d", s);
2315 state->max_packet_size = s;
2316 return s;
2317}
2318
2319int
2320ssh_packet_inc_alive_timeouts(struct ssh *ssh)
2321{
2322 return ++ssh->state->keep_alive_timeouts;
2323}
2324
2325void
2326ssh_packet_set_alive_timeouts(struct ssh *ssh, int ka)
2327{
2328 ssh->state->keep_alive_timeouts = ka;
2329}
2330
2331u_int
2332ssh_packet_get_maxsize(struct ssh *ssh)
2333{
2334 return ssh->state->max_packet_size;
2335}
2336
2337/*
2338 * 9.2. Ignored Data Message
2339 *
2340 * byte SSH_MSG_IGNORE
2341 * string data
2342 *
2343 * All implementations MUST understand (and ignore) this message at any
2344 * time (after receiving the protocol version). No implementation is
2345 * required to send them. This message can be used as an additional
2346 * protection measure against advanced traffic analysis techniques.
2347 */
2348void
2349ssh_packet_send_ignore(struct ssh *ssh, int nbytes)
2350{
2351 u_int32_t rnd = 0;
2352 int r, i;
2353
2354 if ((r = sshpkt_start(ssh, compat20 ?
2355 SSH2_MSG_IGNORE : SSH_MSG_IGNORE)) != 0 ||
2356 (r = sshpkt_put_u32(ssh, nbytes)) != 0)
2357 fatal("%s: %s", __func__, ssh_err(r));
2358 for (i = 0; i < nbytes; i++) {
2359 if (i % 4 == 0)
2360 rnd = arc4random();
2361 if ((r = sshpkt_put_u8(ssh, (u_char)rnd & 0xff)) != 0)
2362 fatal("%s: %s", __func__, ssh_err(r));
2363 rnd >>= 8;
2364 }
2365}
2366
2367void
2368ssh_packet_set_rekey_limits(struct ssh *ssh, u_int64_t bytes, time_t seconds)
2369{
2370 debug3("rekey after %llu bytes, %d seconds", (unsigned long long)bytes,
2371 (int)seconds);
2372 ssh->state->rekey_limit = bytes;
2373 ssh->state->rekey_interval = seconds;
2374}
2375
2376time_t
2377ssh_packet_get_rekey_timeout(struct ssh *ssh)
2378{
2379 time_t seconds;
2380
2381 seconds = ssh->state->rekey_time + ssh->state->rekey_interval -
2382 monotime();
2383 return (seconds <= 0 ? 1 : seconds);
2384}
2385
2386void
2387ssh_packet_set_server(struct ssh *ssh)
2388{
2389 ssh->state->server_side = 1;
2390}
2391
2392void
2393ssh_packet_set_authenticated(struct ssh *ssh)
2394{
2395 ssh->state->after_authentication = 1;
2396}
2397
2398void *
2399ssh_packet_get_input(struct ssh *ssh)
2400{
2401 return (void *)ssh->state->input;
2402}
2403
2404void *
2405ssh_packet_get_output(struct ssh *ssh)
2406{
2407 return (void *)ssh->state->output;
2408}
2409
2410/* Reset after_authentication and reset compression in post-auth privsep */
2411static int
2412ssh_packet_set_postauth(struct ssh *ssh)
2413{
2414 struct sshcomp *comp;
2415 int r, mode;
2416
2417 debug("%s: called", __func__);
2418 /* This was set in net child, but is not visible in user child */
2419 ssh->state->after_authentication = 1;
2420 ssh->state->rekeying = 0;
2421 for (mode = 0; mode < MODE_MAX; mode++) {
2422 if (ssh->state->newkeys[mode] == NULL)
2423 continue;
2424 comp = &ssh->state->newkeys[mode]->comp;
2425 if (comp && comp->enabled &&
2426 (r = ssh_packet_init_compression(ssh)) != 0)
2427 return r;
2428 }
2429 return 0;
2430}
2431
2432/* Packet state (de-)serialization for privsep */
2433
2434/* turn kex into a blob for packet state serialization */
2435static int
2436kex_to_blob(struct sshbuf *m, struct kex *kex)
2437{
2438 int r;
2439
2440 if ((r = sshbuf_put_string(m, kex->session_id,
2441 kex->session_id_len)) != 0 ||
2442 (r = sshbuf_put_u32(m, kex->we_need)) != 0 ||
2443 (r = sshbuf_put_u32(m, kex->hostkey_type)) != 0 ||
2444 (r = sshbuf_put_u32(m, kex->kex_type)) != 0 ||
2445 (r = sshbuf_put_stringb(m, kex->my)) != 0 ||
2446 (r = sshbuf_put_stringb(m, kex->peer)) != 0 ||
2447 (r = sshbuf_put_u32(m, kex->flags)) != 0 ||
2448 (r = sshbuf_put_cstring(m, kex->client_version_string)) != 0 ||
2449 (r = sshbuf_put_cstring(m, kex->server_version_string)) != 0)
2450 return r;
2451 return 0;
2452}
2453
2454/* turn key exchange results into a blob for packet state serialization */
2455static int
2456newkeys_to_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2457{
2458 struct sshbuf *b;
2459 struct sshcipher_ctx *cc;
2460 struct sshcomp *comp;
2461 struct sshenc *enc;
2462 struct sshmac *mac;
2463 struct newkeys *newkey;
2464 int r;
2465
2466 if ((newkey = ssh->state->newkeys[mode]) == NULL)
2467 return SSH_ERR_INTERNAL_ERROR;
2468 enc = &newkey->enc;
2469 mac = &newkey->mac;
2470 comp = &newkey->comp;
2471 cc = (mode == MODE_OUT) ? &ssh->state->send_context :
2472 &ssh->state->receive_context;
2473 if ((r = cipher_get_keyiv(cc, enc->iv, enc->iv_len)) != 0)
2474 return r;
2475 if ((b = sshbuf_new()) == NULL)
2476 return SSH_ERR_ALLOC_FAIL;
2477 /* The cipher struct is constant and shared, you export pointer */
2478 if ((r = sshbuf_put_cstring(b, enc->name)) != 0 ||
2479 (r = sshbuf_put(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2480 (r = sshbuf_put_u32(b, enc->enabled)) != 0 ||
2481 (r = sshbuf_put_u32(b, enc->block_size)) != 0 ||
2482 (r = sshbuf_put_string(b, enc->key, enc->key_len)) != 0 ||
2483 (r = sshbuf_put_string(b, enc->iv, enc->iv_len)) != 0)
2484 goto out;
2485 if (cipher_authlen(enc->cipher) == 0) {
2486 if ((r = sshbuf_put_cstring(b, mac->name)) != 0 ||
2487 (r = sshbuf_put_u32(b, mac->enabled)) != 0 ||
2488 (r = sshbuf_put_string(b, mac->key, mac->key_len)) != 0)
2489 goto out;
2490 }
2491 if ((r = sshbuf_put_u32(b, comp->type)) != 0 ||
2492 (r = sshbuf_put_u32(b, comp->enabled)) != 0 ||
2493 (r = sshbuf_put_cstring(b, comp->name)) != 0)
2494 goto out;
2495 r = sshbuf_put_stringb(m, b);
2496 out:
2497 sshbuf_free(b);
2498 return r;
2499}
2500
2501/* serialize packet state into a blob */
2502int
2503ssh_packet_get_state(struct ssh *ssh, struct sshbuf *m)
2504{
2505 struct session_state *state = ssh->state;
2506 u_char *p;
2507 size_t slen, rlen;
2508 int r, ssh1cipher;
2509
2510 if (!compat20) {
2511 ssh1cipher = cipher_get_number(state->receive_context.cipher);
2512 slen = cipher_get_keyiv_len(&state->send_context);
2513 rlen = cipher_get_keyiv_len(&state->receive_context);
2514 if ((r = sshbuf_put_u32(m, state->remote_protocol_flags)) != 0 ||
2515 (r = sshbuf_put_u32(m, ssh1cipher)) != 0 ||
2516 (r = sshbuf_put_string(m, state->ssh1_key, state->ssh1_keylen)) != 0 ||
2517 (r = sshbuf_put_u32(m, slen)) != 0 ||
2518 (r = sshbuf_reserve(m, slen, &p)) != 0 ||
2519 (r = cipher_get_keyiv(&state->send_context, p, slen)) != 0 ||
2520 (r = sshbuf_put_u32(m, rlen)) != 0 ||
2521 (r = sshbuf_reserve(m, rlen, &p)) != 0 ||
2522 (r = cipher_get_keyiv(&state->receive_context, p, rlen)) != 0)
2523 return r;
2524 } else {
2525 if ((r = kex_to_blob(m, ssh->kex)) != 0 ||
2526 (r = newkeys_to_blob(m, ssh, MODE_OUT)) != 0 ||
2527 (r = newkeys_to_blob(m, ssh, MODE_IN)) != 0 ||
2528 (r = sshbuf_put_u64(m, state->rekey_limit)) != 0 ||
2529 (r = sshbuf_put_u32(m, state->rekey_interval)) != 0 ||
2530 (r = sshbuf_put_u32(m, state->p_send.seqnr)) != 0 ||
2531 (r = sshbuf_put_u64(m, state->p_send.blocks)) != 0 ||
2532 (r = sshbuf_put_u32(m, state->p_send.packets)) != 0 ||
2533 (r = sshbuf_put_u64(m, state->p_send.bytes)) != 0 ||
2534 (r = sshbuf_put_u32(m, state->p_read.seqnr)) != 0 ||
2535 (r = sshbuf_put_u64(m, state->p_read.blocks)) != 0 ||
2536 (r = sshbuf_put_u32(m, state->p_read.packets)) != 0 ||
2537 (r = sshbuf_put_u64(m, state->p_read.bytes)) != 0)
2538 return r;
2539 }
2540
2541 slen = cipher_get_keycontext(&state->send_context, NULL);
2542 rlen = cipher_get_keycontext(&state->receive_context, NULL);
2543 if ((r = sshbuf_put_u32(m, slen)) != 0 ||
2544 (r = sshbuf_reserve(m, slen, &p)) != 0)
2545 return r;
2546 if (cipher_get_keycontext(&state->send_context, p) != (int)slen)
2547 return SSH_ERR_INTERNAL_ERROR;
2548 if ((r = sshbuf_put_u32(m, rlen)) != 0 ||
2549 (r = sshbuf_reserve(m, rlen, &p)) != 0)
2550 return r;
2551 if (cipher_get_keycontext(&state->receive_context, p) != (int)rlen)
2552 return SSH_ERR_INTERNAL_ERROR;
2553
2554 if ((r = ssh_packet_get_compress_state(m, ssh)) != 0 ||
2555 (r = sshbuf_put_stringb(m, state->input)) != 0 ||
2556 (r = sshbuf_put_stringb(m, state->output)) != 0)
2557 return r;
2558
2559 return 0;
2560}
2561
2562/* restore key exchange results from blob for packet state de-serialization */
2563static int
2564newkeys_from_blob(struct sshbuf *m, struct ssh *ssh, int mode)
2565{
2566 struct sshbuf *b = NULL;
2567 struct sshcomp *comp;
2568 struct sshenc *enc;
2569 struct sshmac *mac;
2570 struct newkeys *newkey = NULL;
2571 size_t keylen, ivlen, maclen;
2572 int r;
2573
2574 if ((newkey = calloc(1, sizeof(*newkey))) == NULL) {
2575 r = SSH_ERR_ALLOC_FAIL;
2576 goto out;
2577 }
2578 if ((r = sshbuf_froms(m, &b)) != 0)
2579 goto out;
2580#ifdef DEBUG_PK
2581 sshbuf_dump(b, stderr);
2582#endif
2583 enc = &newkey->enc;
2584 mac = &newkey->mac;
2585 comp = &newkey->comp;
2586
2587 if ((r = sshbuf_get_cstring(b, &enc->name, NULL)) != 0 ||
2588 (r = sshbuf_get(b, &enc->cipher, sizeof(enc->cipher))) != 0 ||
2589 (r = sshbuf_get_u32(b, (u_int *)&enc->enabled)) != 0 ||
2590 (r = sshbuf_get_u32(b, &enc->block_size)) != 0 ||
2591 (r = sshbuf_get_string(b, &enc->key, &keylen)) != 0 ||
2592 (r = sshbuf_get_string(b, &enc->iv, &ivlen)) != 0)
2593 goto out;
2594 if (cipher_authlen(enc->cipher) == 0) {
2595 if ((r = sshbuf_get_cstring(b, &mac->name, NULL)) != 0)
2596 goto out;
2597 if ((r = mac_setup(mac, mac->name)) != 0)
2598 goto out;
2599 if ((r = sshbuf_get_u32(b, (u_int *)&mac->enabled)) != 0 ||
2600 (r = sshbuf_get_string(b, &mac->key, &maclen)) != 0)
2601 goto out;
2602 if (maclen > mac->key_len) {
2603 r = SSH_ERR_INVALID_FORMAT;
2604 goto out;
2605 }
2606 mac->key_len = maclen;
2607 }
2608 if ((r = sshbuf_get_u32(b, &comp->type)) != 0 ||
2609 (r = sshbuf_get_u32(b, (u_int *)&comp->enabled)) != 0 ||
2610 (r = sshbuf_get_cstring(b, &comp->name, NULL)) != 0)
2611 goto out;
2612 if (enc->name == NULL ||
2613 cipher_by_name(enc->name) != enc->cipher) {
2614 r = SSH_ERR_INVALID_FORMAT;
2615 goto out;
2616 }
2617 if (sshbuf_len(b) != 0) {
2618 r = SSH_ERR_INVALID_FORMAT;
2619 goto out;
2620 }
2621 enc->key_len = keylen;
2622 enc->iv_len = ivlen;
2623 ssh->kex->newkeys[mode] = newkey;
2624 newkey = NULL;
2625 r = 0;
2626 out:
2627 free(newkey);
2628 sshbuf_free(b);
2629 return r;
2630}
2631
2632/* restore kex from blob for packet state de-serialization */
2633static int
2634kex_from_blob(struct sshbuf *m, struct kex **kexp)
2635{
2636 struct kex *kex;
2637 int r;
2638
2639 if ((kex = calloc(1, sizeof(struct kex))) == NULL ||
2640 (kex->my = sshbuf_new()) == NULL ||
2641 (kex->peer = sshbuf_new()) == NULL) {
2642 r = SSH_ERR_ALLOC_FAIL;
2643 goto out;
2644 }
2645 if ((r = sshbuf_get_string(m, &kex->session_id, &kex->session_id_len)) != 0 ||
2646 (r = sshbuf_get_u32(m, &kex->we_need)) != 0 ||
2647 (r = sshbuf_get_u32(m, (u_int *)&kex->hostkey_type)) != 0 ||
2648 (r = sshbuf_get_u32(m, &kex->kex_type)) != 0 ||
2649 (r = sshbuf_get_stringb(m, kex->my)) != 0 ||
2650 (r = sshbuf_get_stringb(m, kex->peer)) != 0 ||
2651 (r = sshbuf_get_u32(m, &kex->flags)) != 0 ||
2652 (r = sshbuf_get_cstring(m, &kex->client_version_string, NULL)) != 0 ||
2653 (r = sshbuf_get_cstring(m, &kex->server_version_string, NULL)) != 0)
2654 goto out;
2655 kex->server = 1;
2656 kex->done = 1;
2657 r = 0;
2658 out:
2659 if (r != 0 || kexp == NULL) {
2660 if (kex != NULL) {
2661 sshbuf_free(kex->my);
2662 sshbuf_free(kex->peer);
2663 free(kex);
2664 }
2665 if (kexp != NULL)
2666 *kexp = NULL;
2667 } else {
2668 *kexp = kex;
2669 }
2670 return r;
2671}
2672
2673/*
2674 * Restore packet state from content of blob 'm' (de-serialization).
2675 * Note that 'm' will be partially consumed on parsing or any other errors.
2676 */
2677int
2678ssh_packet_set_state(struct ssh *ssh, struct sshbuf *m)
2679{
2680 struct session_state *state = ssh->state;
2681 const u_char *ssh1key, *ivin, *ivout, *keyin, *keyout, *input, *output;
2682 size_t ssh1keylen, rlen, slen, ilen, olen;
2683 int r;
2684 u_int ssh1cipher = 0;
2685
2686 if (!compat20) {
2687 if ((r = sshbuf_get_u32(m, &state->remote_protocol_flags)) != 0 ||
2688 (r = sshbuf_get_u32(m, &ssh1cipher)) != 0 ||
2689 (r = sshbuf_get_string_direct(m, &ssh1key, &ssh1keylen)) != 0 ||
2690 (r = sshbuf_get_string_direct(m, &ivout, &slen)) != 0 ||
2691 (r = sshbuf_get_string_direct(m, &ivin, &rlen)) != 0)
2692 return r;
2693 if (ssh1cipher > INT_MAX)
2694 return SSH_ERR_KEY_UNKNOWN_CIPHER;
2695 ssh_packet_set_encryption_key(ssh, ssh1key, ssh1keylen,
2696 (int)ssh1cipher);
2697 if (cipher_get_keyiv_len(&state->send_context) != (int)slen ||
2698 cipher_get_keyiv_len(&state->receive_context) != (int)rlen)
2699 return SSH_ERR_INVALID_FORMAT;
2700 if ((r = cipher_set_keyiv(&state->send_context, ivout)) != 0 ||
2701 (r = cipher_set_keyiv(&state->receive_context, ivin)) != 0)
2702 return r;
2703 } else {
2704 if ((r = kex_from_blob(m, &ssh->kex)) != 0 ||
2705 (r = newkeys_from_blob(m, ssh, MODE_OUT)) != 0 ||
2706 (r = newkeys_from_blob(m, ssh, MODE_IN)) != 0 ||
2707 (r = sshbuf_get_u64(m, &state->rekey_limit)) != 0 ||
2708 (r = sshbuf_get_u32(m, &state->rekey_interval)) != 0 ||
2709 (r = sshbuf_get_u32(m, &state->p_send.seqnr)) != 0 ||
2710 (r = sshbuf_get_u64(m, &state->p_send.blocks)) != 0 ||
2711 (r = sshbuf_get_u32(m, &state->p_send.packets)) != 0 ||
2712 (r = sshbuf_get_u64(m, &state->p_send.bytes)) != 0 ||
2713 (r = sshbuf_get_u32(m, &state->p_read.seqnr)) != 0 ||
2714 (r = sshbuf_get_u64(m, &state->p_read.blocks)) != 0 ||
2715 (r = sshbuf_get_u32(m, &state->p_read.packets)) != 0 ||
2716 (r = sshbuf_get_u64(m, &state->p_read.bytes)) != 0)
2717 return r;
2718 /*
2719 * We set the time here so that in post-auth privsep slave we
2720 * count from the completion of the authentication.
2721 */
2722 state->rekey_time = monotime();
2723 /* XXX ssh_set_newkeys overrides p_read.packets? XXX */
2724 if ((r = ssh_set_newkeys(ssh, MODE_IN)) != 0 ||
2725 (r = ssh_set_newkeys(ssh, MODE_OUT)) != 0)
2726 return r;
2727 }
2728 if ((r = sshbuf_get_string_direct(m, &keyout, &slen)) != 0 ||
2729 (r = sshbuf_get_string_direct(m, &keyin, &rlen)) != 0)
2730 return r;
2731 if (cipher_get_keycontext(&state->send_context, NULL) != (int)slen ||
2732 cipher_get_keycontext(&state->receive_context, NULL) != (int)rlen)
2733 return SSH_ERR_INVALID_FORMAT;
2734 cipher_set_keycontext(&state->send_context, keyout);
2735 cipher_set_keycontext(&state->receive_context, keyin);
2736
2737 if ((r = ssh_packet_set_compress_state(ssh, m)) != 0 ||
2738 (r = ssh_packet_set_postauth(ssh)) != 0)
2739 return r;
2740
2741 sshbuf_reset(state->input);
2742 sshbuf_reset(state->output);
2743 if ((r = sshbuf_get_string_direct(m, &input, &ilen)) != 0 ||
2744 (r = sshbuf_get_string_direct(m, &output, &olen)) != 0 ||
2745 (r = sshbuf_put(state->input, input, ilen)) != 0 ||
2746 (r = sshbuf_put(state->output, output, olen)) != 0)
2747 return r;
2748
2749 if (sshbuf_len(m))
2750 return SSH_ERR_INVALID_FORMAT;
2751 debug3("%s: done", __func__);
2752 return 0;
2753}
2754
2755/* NEW API */
2756
2757/* put data to the outgoing packet */
2758
2759int
2760sshpkt_put(struct ssh *ssh, const void *v, size_t len)
2761{
2762 return sshbuf_put(ssh->state->outgoing_packet, v, len);
2763}
2764
2765int
2766sshpkt_putb(struct ssh *ssh, const struct sshbuf *b)
2767{
2768 return sshbuf_putb(ssh->state->outgoing_packet, b);
2769}
2770
2771int
2772sshpkt_put_u8(struct ssh *ssh, u_char val)
2773{
2774 return sshbuf_put_u8(ssh->state->outgoing_packet, val);
2775}
2776
2777int
2778sshpkt_put_u32(struct ssh *ssh, u_int32_t val)
2779{
2780 return sshbuf_put_u32(ssh->state->outgoing_packet, val);
2781}
2782
2783int
2784sshpkt_put_u64(struct ssh *ssh, u_int64_t val)
2785{
2786 return sshbuf_put_u64(ssh->state->outgoing_packet, val);
2787}
2788
2789int
2790sshpkt_put_string(struct ssh *ssh, const void *v, size_t len)
2791{
2792 return sshbuf_put_string(ssh->state->outgoing_packet, v, len);
2793}
2794
2795int
2796sshpkt_put_cstring(struct ssh *ssh, const void *v)
2797{
2798 return sshbuf_put_cstring(ssh->state->outgoing_packet, v);
2799}
2800
2801int
2802sshpkt_put_stringb(struct ssh *ssh, const struct sshbuf *v)
2803{
2804 return sshbuf_put_stringb(ssh->state->outgoing_packet, v);
2805}
2806
2807#ifdef WITH_OPENSSL
2808#ifdef OPENSSL_HAS_ECC
2809int
2810sshpkt_put_ec(struct ssh *ssh, const EC_POINT *v, const EC_GROUP *g)
2811{
2812 return sshbuf_put_ec(ssh->state->outgoing_packet, v, g);
2813}
2814#endif /* OPENSSL_HAS_ECC */
2815
2816#ifdef WITH_SSH1
2817int
2818sshpkt_put_bignum1(struct ssh *ssh, const BIGNUM *v)
2819{
2820 return sshbuf_put_bignum1(ssh->state->outgoing_packet, v);
2821}
2822#endif /* WITH_SSH1 */
2823
2824int
2825sshpkt_put_bignum2(struct ssh *ssh, const BIGNUM *v)
2826{
2827 return sshbuf_put_bignum2(ssh->state->outgoing_packet, v);
2828}
2829#endif /* WITH_OPENSSL */
2830
2831/* fetch data from the incoming packet */
2832
2833int
2834sshpkt_get(struct ssh *ssh, void *valp, size_t len)
2835{
2836 return sshbuf_get(ssh->state->incoming_packet, valp, len);
2837}
2838
2839int
2840sshpkt_get_u8(struct ssh *ssh, u_char *valp)
2841{
2842 return sshbuf_get_u8(ssh->state->incoming_packet, valp);
2843}
2844
2845int
2846sshpkt_get_u32(struct ssh *ssh, u_int32_t *valp)
2847{
2848 return sshbuf_get_u32(ssh->state->incoming_packet, valp);
2849}
2850
2851int
2852sshpkt_get_u64(struct ssh *ssh, u_int64_t *valp)
2853{
2854 return sshbuf_get_u64(ssh->state->incoming_packet, valp);
2855}
2856
2857int
2858sshpkt_get_string(struct ssh *ssh, u_char **valp, size_t *lenp)
2859{
2860 return sshbuf_get_string(ssh->state->incoming_packet, valp, lenp);
2861}
2862
2863int
2864sshpkt_get_string_direct(struct ssh *ssh, const u_char **valp, size_t *lenp)
2865{
2866 return sshbuf_get_string_direct(ssh->state->incoming_packet, valp, lenp);
2867}
2868
2869int
2870sshpkt_get_cstring(struct ssh *ssh, char **valp, size_t *lenp)
2871{
2872 return sshbuf_get_cstring(ssh->state->incoming_packet, valp, lenp);
2873}
2874
2875#ifdef WITH_OPENSSL
2876#ifdef OPENSSL_HAS_ECC
2877int
2878sshpkt_get_ec(struct ssh *ssh, EC_POINT *v, const EC_GROUP *g)
2879{
2880 return sshbuf_get_ec(ssh->state->incoming_packet, v, g);
2881}
2882#endif /* OPENSSL_HAS_ECC */
2883
2884#ifdef WITH_SSH1
2885int
2886sshpkt_get_bignum1(struct ssh *ssh, BIGNUM *v)
2887{
2888 return sshbuf_get_bignum1(ssh->state->incoming_packet, v);
2889}
2890#endif /* WITH_SSH1 */
2891
2892int
2893sshpkt_get_bignum2(struct ssh *ssh, BIGNUM *v)
2894{
2895 return sshbuf_get_bignum2(ssh->state->incoming_packet, v);
2896}
2897#endif /* WITH_OPENSSL */
2898
2899int
2900sshpkt_get_end(struct ssh *ssh)
2901{
2902 if (sshbuf_len(ssh->state->incoming_packet) > 0)
2903 return SSH_ERR_UNEXPECTED_TRAILING_DATA;
2904 return 0;
2905}
2906
2907const u_char *
2908sshpkt_ptr(struct ssh *ssh, size_t *lenp)
2909{
2910 if (lenp != NULL)
2911 *lenp = sshbuf_len(ssh->state->incoming_packet);
2912 return sshbuf_ptr(ssh->state->incoming_packet);
2913}
2914
2915/* start a new packet */
2916
2917int
2918sshpkt_start(struct ssh *ssh, u_char type)
2919{
2920 u_char buf[9];
2921 int len;
2922
2923 DBG(debug("packet_start[%d]", type));
2924 len = compat20 ? 6 : 9;
2925 memset(buf, 0, len - 1);
2926 buf[len - 1] = type;
2927 sshbuf_reset(ssh->state->outgoing_packet);
2928 return sshbuf_put(ssh->state->outgoing_packet, buf, len);
2929}
2930
2931/* send it */
2932
2933int
2934sshpkt_send(struct ssh *ssh)
2935{
2936 if (compat20)
2937 return ssh_packet_send2(ssh);
2938 else
2939 return ssh_packet_send1(ssh);
2940}
2941
2942int
2943sshpkt_disconnect(struct ssh *ssh, const char *fmt,...)
2944{
2945 char buf[1024];
2946 va_list args;
2947 int r;
2948
2949 va_start(args, fmt);
2950 vsnprintf(buf, sizeof(buf), fmt, args);
2951 va_end(args);
2952
2953 if (compat20) {
2954 if ((r = sshpkt_start(ssh, SSH2_MSG_DISCONNECT)) != 0 ||
2955 (r = sshpkt_put_u32(ssh, SSH2_DISCONNECT_PROTOCOL_ERROR)) != 0 ||
2956 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2957 (r = sshpkt_put_cstring(ssh, "")) != 0 ||
2958 (r = sshpkt_send(ssh)) != 0)
2959 return r;
2960 } else {
2961 if ((r = sshpkt_start(ssh, SSH_MSG_DISCONNECT)) != 0 ||
2962 (r = sshpkt_put_cstring(ssh, buf)) != 0 ||
2963 (r = sshpkt_send(ssh)) != 0)
2964 return r;
2965 }
2966 return 0;
2967}
2968
2969/* roundup current message to pad bytes */
2970int
2971sshpkt_add_padding(struct ssh *ssh, u_char pad)
2972{
2973 ssh->state->extra_pad = pad;
2974 return 0;
2975}
|